--- /dev/null
- [`significant_drop_in_scrutinee`]: https://rust-lang.github.io/rust-clippy/master/index.html#significant_drop_in_scrutinee
+# Changelog
+
+All notable changes to this project will be documented in this file.
+See [Changelog Update](doc/changelog_update.md) if you want to update this
+document.
+
+## Unreleased / In Rust Nightly
+
+[d0cf3481...master](https://github.com/rust-lang/rust-clippy/compare/d0cf3481...master)
+
+## Rust 1.61
+
+Current stable, released 2022-05-19
+
+[57b3c4b...d0cf3481](https://github.com/rust-lang/rust-clippy/compare/57b3c4b...d0cf3481)
+
+### New Lints
+
+* [`only_used_in_recursion`]
+ [#8422](https://github.com/rust-lang/rust-clippy/pull/8422)
+* [`cast_enum_truncation`]
+ [#8381](https://github.com/rust-lang/rust-clippy/pull/8381)
+* [`missing_spin_loop`]
+ [#8174](https://github.com/rust-lang/rust-clippy/pull/8174)
+* [`deref_by_slicing`]
+ [#8218](https://github.com/rust-lang/rust-clippy/pull/8218)
+* [`needless_match`]
+ [#8471](https://github.com/rust-lang/rust-clippy/pull/8471)
+* [`allow_attributes_without_reason`] (Requires `#![feature(lint_reasons)]`)
+ [#8504](https://github.com/rust-lang/rust-clippy/pull/8504)
+* [`print_in_format_impl`]
+ [#8253](https://github.com/rust-lang/rust-clippy/pull/8253)
+* [`unnecessary_find_map`]
+ [#8489](https://github.com/rust-lang/rust-clippy/pull/8489)
+* [`or_then_unwrap`]
+ [#8561](https://github.com/rust-lang/rust-clippy/pull/8561)
+* [`unnecessary_join`]
+ [#8579](https://github.com/rust-lang/rust-clippy/pull/8579)
+* [`iter_with_drain`]
+ [#8483](https://github.com/rust-lang/rust-clippy/pull/8483)
+* [`cast_enum_constructor`]
+ [#8562](https://github.com/rust-lang/rust-clippy/pull/8562)
+* [`cast_slice_different_sizes`]
+ [#8445](https://github.com/rust-lang/rust-clippy/pull/8445)
+
+### Moves and Deprecations
+
+* Moved [`transmute_undefined_repr`] to `nursery` (now allow-by-default)
+ [#8432](https://github.com/rust-lang/rust-clippy/pull/8432)
+* Moved [`try_err`] to `restriction`
+ [#8544](https://github.com/rust-lang/rust-clippy/pull/8544)
+* Move [`iter_with_drain`] to `nursery`
+ [#8541](https://github.com/rust-lang/rust-clippy/pull/8541)
+* Renamed `to_string_in_display` to [`recursive_format_impl`]
+ [#8188](https://github.com/rust-lang/rust-clippy/pull/8188)
+
+### Enhancements
+
+* [`dbg_macro`]: The lint level can now be set with crate attributes and works inside macros
+ [#8411](https://github.com/rust-lang/rust-clippy/pull/8411)
+* [`ptr_as_ptr`]: Now works inside macros
+ [#8442](https://github.com/rust-lang/rust-clippy/pull/8442)
+* [`use_self`]: Now works for variants in match expressions
+ [#8456](https://github.com/rust-lang/rust-clippy/pull/8456)
+* [`await_holding_lock`]: Now lints for `parking_lot::{Mutex, RwLock}`
+ [#8419](https://github.com/rust-lang/rust-clippy/pull/8419)
+* [`recursive_format_impl`]: Now checks for format calls on `self`
+ [#8188](https://github.com/rust-lang/rust-clippy/pull/8188)
+
+### False Positive Fixes
+
+* [`new_without_default`]: No longer lints for `new()` methods with `#[doc(hidden)]`
+ [#8472](https://github.com/rust-lang/rust-clippy/pull/8472)
+* [`transmute_undefined_repr`]: No longer lints for single field structs with `#[repr(C)]`,
+ generic parameters, wide pointers, unions, tuples and allow several forms of type erasure
+ [#8425](https://github.com/rust-lang/rust-clippy/pull/8425)
+ [#8553](https://github.com/rust-lang/rust-clippy/pull/8553)
+ [#8440](https://github.com/rust-lang/rust-clippy/pull/8440)
+ [#8547](https://github.com/rust-lang/rust-clippy/pull/8547)
+* [`match_single_binding`], [`match_same_arms`], [`match_as_ref`], [`match_bool`]: No longer
+ lint `match` expressions with `cfg`ed arms
+ [#8443](https://github.com/rust-lang/rust-clippy/pull/8443)
+* [`single_component_path_imports`]: No longer lint on macros
+ [#8537](https://github.com/rust-lang/rust-clippy/pull/8537)
+* [`ptr_arg`]: Allow `&mut` arguments for `Cow<_>`
+ [#8552](https://github.com/rust-lang/rust-clippy/pull/8552)
+* [`needless_borrow`]: No longer lints for method calls
+ [#8441](https://github.com/rust-lang/rust-clippy/pull/8441)
+* [`match_same_arms`]: Now ensures that interposing arm patterns don't overlap
+ [#8232](https://github.com/rust-lang/rust-clippy/pull/8232)
+* [`default_trait_access`]: Now allows `Default::default` in update expressions
+ [#8433](https://github.com/rust-lang/rust-clippy/pull/8433)
+
+### Suggestion Fixes/Improvements
+
+* [`redundant_slicing`]: Fixed suggestion for a method calls
+ [#8218](https://github.com/rust-lang/rust-clippy/pull/8218)
+* [`map_flatten`]: Long suggestions will now be split up into two help messages
+ [#8520](https://github.com/rust-lang/rust-clippy/pull/8520)
+* [`unnecessary_lazy_evaluations`]: Now shows suggestions for longer code snippets
+ [#8543](https://github.com/rust-lang/rust-clippy/pull/8543)
+* [`unnecessary_sort_by`]: Now suggests `Reverse` including the path
+ [#8462](https://github.com/rust-lang/rust-clippy/pull/8462)
+* [`search_is_some`]: More suggestions are now `MachineApplicable`
+ [#8536](https://github.com/rust-lang/rust-clippy/pull/8536)
+
+### Documentation Improvements
+
+* [`new_without_default`]: Document `pub` requirement for the struct and fields
+ [#8429](https://github.com/rust-lang/rust-clippy/pull/8429)
+
+## Rust 1.60
+
+Released 2022-04-07
+
+[0eff589...57b3c4b](https://github.com/rust-lang/rust-clippy/compare/0eff589...57b3c4b)
+
+### New Lints
+
+* [`single_char_lifetime_names`]
+ [#8236](https://github.com/rust-lang/rust-clippy/pull/8236)
+* [`iter_overeager_cloned`]
+ [#8203](https://github.com/rust-lang/rust-clippy/pull/8203)
+* [`transmute_undefined_repr`]
+ [#8398](https://github.com/rust-lang/rust-clippy/pull/8398)
+* [`default_union_representation`]
+ [#8289](https://github.com/rust-lang/rust-clippy/pull/8289)
+* [`manual_bits`]
+ [#8213](https://github.com/rust-lang/rust-clippy/pull/8213)
+* [`borrow_as_ptr`]
+ [#8210](https://github.com/rust-lang/rust-clippy/pull/8210)
+
+### Moves and Deprecations
+
+* Moved [`disallowed_methods`] and [`disallowed_types`] to `style` (now warn-by-default)
+ [#8261](https://github.com/rust-lang/rust-clippy/pull/8261)
+* Rename `ref_in_deref` to [`needless_borrow`]
+ [#8217](https://github.com/rust-lang/rust-clippy/pull/8217)
+* Moved [`mutex_atomic`] to `nursery` (now allow-by-default)
+ [#8260](https://github.com/rust-lang/rust-clippy/pull/8260)
+
+### Enhancements
+
+* [`ptr_arg`]: Now takes the argument usage into account and lints for mutable references
+ [#8271](https://github.com/rust-lang/rust-clippy/pull/8271)
+* [`unused_io_amount`]: Now supports async read and write traits
+ [#8179](https://github.com/rust-lang/rust-clippy/pull/8179)
+* [`while_let_on_iterator`]: Improved detection to catch more cases
+ [#8221](https://github.com/rust-lang/rust-clippy/pull/8221)
+* [`trait_duplication_in_bounds`]: Now covers trait functions with `Self` bounds
+ [#8252](https://github.com/rust-lang/rust-clippy/pull/8252)
+* [`unwrap_used`]: Now works for `.get(i).unwrap()` and `.get_mut(i).unwrap()`
+ [#8372](https://github.com/rust-lang/rust-clippy/pull/8372)
+* [`map_clone`]: The suggestion takes `msrv` into account
+ [#8280](https://github.com/rust-lang/rust-clippy/pull/8280)
+* [`manual_bits`] and [`borrow_as_ptr`]: Now track the `clippy::msrv` attribute
+ [#8280](https://github.com/rust-lang/rust-clippy/pull/8280)
+* [`disallowed_methods`]: Now works for methods on primitive types
+ [#8112](https://github.com/rust-lang/rust-clippy/pull/8112)
+* [`not_unsafe_ptr_arg_deref`]: Now works for type aliases
+ [#8273](https://github.com/rust-lang/rust-clippy/pull/8273)
+* [`needless_question_mark`]: Now works for async functions
+ [#8311](https://github.com/rust-lang/rust-clippy/pull/8311)
+* [`iter_not_returning_iterator`]: Now handles type projections
+ [#8228](https://github.com/rust-lang/rust-clippy/pull/8228)
+* [`wrong_self_convention`]: Now detects wrong `self` references in more cases
+ [#8208](https://github.com/rust-lang/rust-clippy/pull/8208)
+* [`single_match`]: Now works for `match` statements with tuples
+ [#8322](https://github.com/rust-lang/rust-clippy/pull/8322)
+
+### False Positive Fixes
+
+* [`erasing_op`]: No longer triggers if the output type changes
+ [#8204](https://github.com/rust-lang/rust-clippy/pull/8204)
+* [`if_same_then_else`]: No longer triggers for `if let` statements
+ [#8297](https://github.com/rust-lang/rust-clippy/pull/8297)
+* [`manual_memcpy`]: No longer lints on `VecDeque`
+ [#8226](https://github.com/rust-lang/rust-clippy/pull/8226)
+* [`trait_duplication_in_bounds`]: Now takes path segments into account
+ [#8315](https://github.com/rust-lang/rust-clippy/pull/8315)
+* [`deref_addrof`]: No longer lints when the dereference or borrow occurs in different a context
+ [#8268](https://github.com/rust-lang/rust-clippy/pull/8268)
+* [`type_repetition_in_bounds`]: Now checks for full equality to prevent false positives
+ [#8224](https://github.com/rust-lang/rust-clippy/pull/8224)
+* [`ptr_arg`]: No longer lint for mutable references in traits
+ [#8369](https://github.com/rust-lang/rust-clippy/pull/8369)
+* [`implicit_clone`]: No longer lints for double references
+ [#8231](https://github.com/rust-lang/rust-clippy/pull/8231)
+* [`needless_lifetimes`]: No longer lints lifetimes for explicit `self` types
+ [#8278](https://github.com/rust-lang/rust-clippy/pull/8278)
+* [`op_ref`]: No longer lints in `BinOp` impl if that can cause recursion
+ [#8298](https://github.com/rust-lang/rust-clippy/pull/8298)
+* [`enum_variant_names`]: No longer triggers for empty variant names
+ [#8329](https://github.com/rust-lang/rust-clippy/pull/8329)
+* [`redundant_closure`]: No longer lints for `Arc<T>` or `Rc<T>`
+ [#8193](https://github.com/rust-lang/rust-clippy/pull/8193)
+* [`iter_not_returning_iterator`]: No longer lints on trait implementations but therefore on trait definitions
+ [#8228](https://github.com/rust-lang/rust-clippy/pull/8228)
+* [`single_match`]: No longer lints on exhaustive enum patterns without a wildcard
+ [#8322](https://github.com/rust-lang/rust-clippy/pull/8322)
+* [`manual_swap`]: No longer lints on cases that involve automatic dereferences
+ [#8220](https://github.com/rust-lang/rust-clippy/pull/8220)
+* [`useless_format`]: Now works for implicit named arguments
+ [#8295](https://github.com/rust-lang/rust-clippy/pull/8295)
+
+### Suggestion Fixes/Improvements
+
+* [`needless_borrow`]: Prevent mutable borrows being moved and suggest removing the borrow on method calls
+ [#8217](https://github.com/rust-lang/rust-clippy/pull/8217)
+* [`chars_next_cmp`]: Correctly excapes the suggestion
+ [#8376](https://github.com/rust-lang/rust-clippy/pull/8376)
+* [`explicit_write`]: Add suggestions for `write!`s with format arguments
+ [#8365](https://github.com/rust-lang/rust-clippy/pull/8365)
+* [`manual_memcpy`]: Suggests `copy_from_slice` when applicable
+ [#8226](https://github.com/rust-lang/rust-clippy/pull/8226)
+* [`or_fun_call`]: Improved suggestion display for long arguments
+ [#8292](https://github.com/rust-lang/rust-clippy/pull/8292)
+* [`unnecessary_cast`]: Now correctly includes the sign
+ [#8350](https://github.com/rust-lang/rust-clippy/pull/8350)
+* [`cmp_owned`]: No longer flips the comparison order
+ [#8299](https://github.com/rust-lang/rust-clippy/pull/8299)
+* [`explicit_counter_loop`]: Now correctly suggests `iter()` on references
+ [#8382](https://github.com/rust-lang/rust-clippy/pull/8382)
+
+### ICE Fixes
+
+* [`manual_split_once`]
+ [#8250](https://github.com/rust-lang/rust-clippy/pull/8250)
+
+### Documentation Improvements
+
+* [`map_flatten`]: Add documentation for the `Option` type
+ [#8354](https://github.com/rust-lang/rust-clippy/pull/8354)
+* Document that Clippy's driver might use a different code generation than rustc
+ [#8037](https://github.com/rust-lang/rust-clippy/pull/8037)
+* Clippy's lint list will now automatically focus the search box
+ [#8343](https://github.com/rust-lang/rust-clippy/pull/8343)
+
+### Others
+
+* Clippy now warns if we find multiple Clippy config files exist
+ [#8326](https://github.com/rust-lang/rust-clippy/pull/8326)
+
+## Rust 1.59
+
+Released 2022-02-24
+
+[e181011...0eff589](https://github.com/rust-lang/rust-clippy/compare/e181011...0eff589)
+
+### New Lints
+
+* [`index_refutable_slice`]
+ [#7643](https://github.com/rust-lang/rust-clippy/pull/7643)
+* [`needless_splitn`]
+ [#7896](https://github.com/rust-lang/rust-clippy/pull/7896)
+* [`unnecessary_to_owned`]
+ [#7978](https://github.com/rust-lang/rust-clippy/pull/7978)
+* [`needless_late_init`]
+ [#7995](https://github.com/rust-lang/rust-clippy/pull/7995)
+* [`octal_escapes`] [#8007](https://github.com/rust-lang/rust-clippy/pull/8007)
+* [`return_self_not_must_use`]
+ [#8071](https://github.com/rust-lang/rust-clippy/pull/8071)
+* [`init_numbered_fields`]
+ [#8170](https://github.com/rust-lang/rust-clippy/pull/8170)
+
+### Moves and Deprecations
+
+* Move `if_then_panic` to `pedantic` and rename to [`manual_assert`] (now
+ allow-by-default) [#7810](https://github.com/rust-lang/rust-clippy/pull/7810)
+* Rename `disallow_type` to [`disallowed_types`] and `disallowed_method` to
+ [`disallowed_methods`]
+ [#7984](https://github.com/rust-lang/rust-clippy/pull/7984)
+* Move [`map_flatten`] to `complexity` (now warn-by-default)
+ [#8054](https://github.com/rust-lang/rust-clippy/pull/8054)
+
+### Enhancements
+
+* [`match_overlapping_arm`]: Fix false negative where after included ranges,
+ overlapping ranges weren't linted anymore
+ [#7909](https://github.com/rust-lang/rust-clippy/pull/7909)
+* [`deprecated_cfg_attr`]: Now takes the specified MSRV into account
+ [#7944](https://github.com/rust-lang/rust-clippy/pull/7944)
+* [`cast_lossless`]: Now also lints for `bool` to integer casts
+ [#7948](https://github.com/rust-lang/rust-clippy/pull/7948)
+* [`let_underscore_lock`]: Also emit lints for the `parking_lot` crate
+ [#7957](https://github.com/rust-lang/rust-clippy/pull/7957)
+* [`needless_borrow`]
+ [#7977](https://github.com/rust-lang/rust-clippy/pull/7977)
+ * Lint when a borrow is auto-dereffed more than once
+ * Lint in the trailing expression of a block for a match arm
+* [`strlen_on_c_strings`]
+ [8001](https://github.com/rust-lang/rust-clippy/pull/8001)
+ * Lint when used without a fully-qualified path
+ * Suggest removing the surrounding unsafe block when possible
+* [`non_ascii_literal`]: Now also lints on `char`s, not just `string`s
+ [#8034](https://github.com/rust-lang/rust-clippy/pull/8034)
+* [`single_char_pattern`]: Now also lints on `split_inclusive`, `split_once`,
+ `rsplit_once`, `replace`, and `replacen`
+ [#8077](https://github.com/rust-lang/rust-clippy/pull/8077)
+* [`unwrap_or_else_default`]: Now also lints on `std` constructors like
+ `Vec::new`, `HashSet::new`, and `HashMap::new`
+ [#8163](https://github.com/rust-lang/rust-clippy/pull/8163)
+* [`shadow_reuse`]: Now also lints on shadowed `if let` bindings, instead of
+ [`shadow_unrelated`]
+ [#8165](https://github.com/rust-lang/rust-clippy/pull/8165)
+
+### False Positive Fixes
+
+* [`or_fun_call`], [`unnecessary_lazy_evaluations`]: Improve heuristics, so that
+ cheap functions (e.g. calling `.len()` on a `Vec`) won't get linted anymore
+ [#7639](https://github.com/rust-lang/rust-clippy/pull/7639)
+* [`manual_split_once`]: No longer suggests code changing the original behavior
+ [#7896](https://github.com/rust-lang/rust-clippy/pull/7896)
+* Don't show [`no_effect`] or [`unnecessary_operation`] warning for unit struct
+ implementing `FnOnce`
+ [#7898](https://github.com/rust-lang/rust-clippy/pull/7898)
+* [`semicolon_if_nothing_returned`]: Fixed a bug, where the lint wrongly
+ triggered on `let-else` statements
+ [#7955](https://github.com/rust-lang/rust-clippy/pull/7955)
+* [`if_then_some_else_none`]: No longer lints if there is an early return
+ [#7980](https://github.com/rust-lang/rust-clippy/pull/7980)
+* [`needless_collect`]: No longer suggests removal of `collect` when removal
+ would create code requiring mutably borrowing a value multiple times
+ [#7982](https://github.com/rust-lang/rust-clippy/pull/7982)
+* [`shadow_same`]: Fix false positive for `async` function's params
+ [#7997](https://github.com/rust-lang/rust-clippy/pull/7997)
+* [`suboptimal_flops`]: No longer triggers in constant functions
+ [#8009](https://github.com/rust-lang/rust-clippy/pull/8009)
+* [`type_complexity`]: No longer lints on associated types in traits
+ [#8030](https://github.com/rust-lang/rust-clippy/pull/8030)
+* [`question_mark`]: No longer lints if returned object is not local
+ [#8080](https://github.com/rust-lang/rust-clippy/pull/8080)
+* [`option_if_let_else`]: No longer lint on complex sub-patterns
+ [#8086](https://github.com/rust-lang/rust-clippy/pull/8086)
+* [`blocks_in_if_conditions`]: No longer lints on empty closures
+ [#8100](https://github.com/rust-lang/rust-clippy/pull/8100)
+* [`enum_variant_names`]: No longer lint when first prefix is only a substring
+ of a camel-case word
+ [#8127](https://github.com/rust-lang/rust-clippy/pull/8127)
+* [`identity_op`]: Only lint on integral operands
+ [#8183](https://github.com/rust-lang/rust-clippy/pull/8183)
+
+### Suggestion Fixes/Improvements
+
+* [`search_is_some`]: Fix suggestion for `any()` not taking item by reference
+ [#7463](https://github.com/rust-lang/rust-clippy/pull/7463)
+* [`almost_swapped`]: Now detects if there is a `no_std` or `no_core` attribute
+ and adapts the suggestion accordingly
+ [#7877](https://github.com/rust-lang/rust-clippy/pull/7877)
+* [`redundant_pattern_matching`]: Fix suggestion for deref expressions
+ [#7949](https://github.com/rust-lang/rust-clippy/pull/7949)
+* [`explicit_counter_loop`]: Now also produces a suggestion for non-`usize`
+ types [#7950](https://github.com/rust-lang/rust-clippy/pull/7950)
+* [`manual_map`]: Fix suggestion when used with unsafe functions and blocks
+ [#7968](https://github.com/rust-lang/rust-clippy/pull/7968)
+* [`option_map_or_none`]: Suggest `map` over `and_then` when possible
+ [#7971](https://github.com/rust-lang/rust-clippy/pull/7971)
+* [`option_if_let_else`]: No longer expands macros in the suggestion
+ [#7974](https://github.com/rust-lang/rust-clippy/pull/7974)
+* [`iter_cloned_collect`]: Suggest `copied` over `cloned` when possible
+ [#8006](https://github.com/rust-lang/rust-clippy/pull/8006)
+* [`doc_markdown`]: No longer uses inline hints to improve readability of
+ suggestion [#8011](https://github.com/rust-lang/rust-clippy/pull/8011)
+* [`needless_question_mark`]: Now better explains the suggestion
+ [#8028](https://github.com/rust-lang/rust-clippy/pull/8028)
+* [`single_char_pattern`]: Escape backslash `\` in suggestion
+ [#8067](https://github.com/rust-lang/rust-clippy/pull/8067)
+* [`needless_bool`]: Suggest `a != b` over `!(a == b)`
+ [#8117](https://github.com/rust-lang/rust-clippy/pull/8117)
+* [`iter_skip_next`]: Suggest to add a `mut` if it is necessary in order to
+ apply this lints suggestion
+ [#8133](https://github.com/rust-lang/rust-clippy/pull/8133)
+* [`neg_multiply`]: Now produces a suggestion
+ [#8144](https://github.com/rust-lang/rust-clippy/pull/8144)
+* [`needless_return`]: Now suggests the unit type `()` over an empty block `{}`
+ in match arms [#8185](https://github.com/rust-lang/rust-clippy/pull/8185)
+* [`suboptimal_flops`]: Now gives a syntactically correct suggestion for
+ `to_radians` and `to_degrees`
+ [#8187](https://github.com/rust-lang/rust-clippy/pull/8187)
+
+### ICE Fixes
+
+* [`undocumented_unsafe_blocks`]
+ [#7945](https://github.com/rust-lang/rust-clippy/pull/7945)
+ [#7988](https://github.com/rust-lang/rust-clippy/pull/7988)
+* [`unnecessary_cast`]
+ [#8167](https://github.com/rust-lang/rust-clippy/pull/8167)
+
+### Documentation Improvements
+
+* [`print_stdout`], [`print_stderr`], [`dbg_macro`]: Document how the lint level
+ can be changed crate-wide
+ [#8040](https://github.com/rust-lang/rust-clippy/pull/8040)
+* Added a note to the `README` that config changes don't apply to already
+ compiled code [#8175](https://github.com/rust-lang/rust-clippy/pull/8175)
+
+### Others
+
+* [Clippy's lint
+ list](https://rust-lang.github.io/rust-clippy/master/index.html) now displays
+ the version a lint was added. :tada:
+ [#7813](https://github.com/rust-lang/rust-clippy/pull/7813)
+* New and improved issue templates
+ [#8032](https://github.com/rust-lang/rust-clippy/pull/8032)
+* _Dev:_ Add `cargo dev lint` command, to run your modified Clippy version on a
+ file [#7917](https://github.com/rust-lang/rust-clippy/pull/7917)
+
+## Rust 1.58
+
+Released 2022-01-13
+
+[00e31fa...e181011](https://github.com/rust-lang/rust-clippy/compare/00e31fa...e181011)
+
+### Rust 1.58.1
+
+* Move [`non_send_fields_in_send_ty`] to `nursery` (now allow-by-default)
+ [#8075](https://github.com/rust-lang/rust-clippy/pull/8075)
+* [`useless_format`]: Handle implicit named arguments
+ [#8295](https://github.com/rust-lang/rust-clippy/pull/8295)
+
+### New lints
+
+* [`transmute_num_to_bytes`]
+ [#7805](https://github.com/rust-lang/rust-clippy/pull/7805)
+* [`match_str_case_mismatch`]
+ [#7806](https://github.com/rust-lang/rust-clippy/pull/7806)
+* [`format_in_format_args`], [`to_string_in_format_args`]
+ [#7743](https://github.com/rust-lang/rust-clippy/pull/7743)
+* [`uninit_vec`]
+ [#7682](https://github.com/rust-lang/rust-clippy/pull/7682)
+* [`fn_to_numeric_cast_any`]
+ [#7705](https://github.com/rust-lang/rust-clippy/pull/7705)
+* [`undocumented_unsafe_blocks`]
+ [#7748](https://github.com/rust-lang/rust-clippy/pull/7748)
+* [`trailing_empty_array`]
+ [#7838](https://github.com/rust-lang/rust-clippy/pull/7838)
+* [`string_slice`]
+ [#7878](https://github.com/rust-lang/rust-clippy/pull/7878)
+
+### Moves or deprecations of lints
+
+* Move [`non_send_fields_in_send_ty`] to `suspicious`
+ [#7874](https://github.com/rust-lang/rust-clippy/pull/7874)
+* Move [`non_ascii_literal`] to `restriction`
+ [#7907](https://github.com/rust-lang/rust-clippy/pull/7907)
+
+### Changes that expand what code existing lints cover
+
+* [`question_mark`] now covers `Result`
+ [#7840](https://github.com/rust-lang/rust-clippy/pull/7840)
+* Make [`useless_format`] recognize bare `format!("")`
+ [#7801](https://github.com/rust-lang/rust-clippy/pull/7801)
+* Lint on underscored variables with no side effects in [`no_effect`]
+ [#7775](https://github.com/rust-lang/rust-clippy/pull/7775)
+* Expand [`match_ref_pats`] to check for multiple reference patterns
+ [#7800](https://github.com/rust-lang/rust-clippy/pull/7800)
+
+### False positive fixes
+
+* Fix false positive of [`implicit_saturating_sub`] with `else` clause
+ [#7832](https://github.com/rust-lang/rust-clippy/pull/7832)
+* Fix [`question_mark`] when there is call in conditional predicate
+ [#7860](https://github.com/rust-lang/rust-clippy/pull/7860)
+* [`mut_mut`] no longer lints when type is defined in external macros
+ [#7795](https://github.com/rust-lang/rust-clippy/pull/7795)
+* Avoid [`eq_op`] in test functions
+ [#7811](https://github.com/rust-lang/rust-clippy/pull/7811)
+* [`cast_possible_truncation`] no longer lints when cast is coming from `signum`
+ method call [#7850](https://github.com/rust-lang/rust-clippy/pull/7850)
+* [`match_str_case_mismatch`] no longer lints on uncased characters
+ [#7865](https://github.com/rust-lang/rust-clippy/pull/7865)
+* [`ptr_arg`] no longer lints references to type aliases
+ [#7890](https://github.com/rust-lang/rust-clippy/pull/7890)
+* [`missing_safety_doc`] now also accepts "implementation safety" headers
+ [#7856](https://github.com/rust-lang/rust-clippy/pull/7856)
+* [`missing_safety_doc`] no longer lints if any parent has `#[doc(hidden)]`
+ attribute [#7849](https://github.com/rust-lang/rust-clippy/pull/7849)
+* [`if_not_else`] now ignores else-if statements
+ [#7895](https://github.com/rust-lang/rust-clippy/pull/7895)
+* Avoid linting [`cast_possible_truncation`] on bit-reducing operations
+ [#7819](https://github.com/rust-lang/rust-clippy/pull/7819)
+* Avoid linting [`field_reassign_with_default`] when `Drop` and `Copy` are
+ involved [#7794](https://github.com/rust-lang/rust-clippy/pull/7794)
+* [`unnecessary_sort_by`] now checks if argument implements `Ord` trait
+ [#7824](https://github.com/rust-lang/rust-clippy/pull/7824)
+* Fix false positive in [`match_overlapping_arm`]
+ [#7847](https://github.com/rust-lang/rust-clippy/pull/7847)
+* Prevent [`needless_lifetimes`] false positive in `async` function definition
+ [#7901](https://github.com/rust-lang/rust-clippy/pull/7901)
+
+### Suggestion fixes/improvements
+
+* Keep an initial `::` when [`doc_markdown`] suggests to use ticks
+ [#7916](https://github.com/rust-lang/rust-clippy/pull/7916)
+* Add a machine applicable suggestion for the [`doc_markdown`] missing backticks
+ lint [#7904](https://github.com/rust-lang/rust-clippy/pull/7904)
+* [`equatable_if_let`] no longer expands macros in the suggestion
+ [#7788](https://github.com/rust-lang/rust-clippy/pull/7788)
+* Make [`shadow_reuse`] suggestion less verbose
+ [#7782](https://github.com/rust-lang/rust-clippy/pull/7782)
+
+### ICE fixes
+
+* Fix ICE in [`enum_variant_names`]
+ [#7873](https://github.com/rust-lang/rust-clippy/pull/7873)
+* Fix ICE in [`undocumented_unsafe_blocks`]
+ [#7891](https://github.com/rust-lang/rust-clippy/pull/7891)
+
+### Documentation improvements
+
+* Fixed naive doc formatting for `#[must_use]` lints ([`must_use_unit`],
+ [`double_must_use`], [`must_use_candidate`], [`let_underscore_must_use`])
+ [#7827](https://github.com/rust-lang/rust-clippy/pull/7827)
+* Fix typo in example for [`match_result_ok`]
+ [#7815](https://github.com/rust-lang/rust-clippy/pull/7815)
+
+### Others
+
+* Allow giving reasons for [`disallowed_types`]
+ [#7791](https://github.com/rust-lang/rust-clippy/pull/7791)
+* Fix [`manual_assert`] and [`match_wild_err_arm`] for `#![no_std]` and Rust
+ 2021. [#7851](https://github.com/rust-lang/rust-clippy/pull/7851)
+* Fix regression in [`semicolon_if_nothing_returned`] on macros containing while
+ loops [#7789](https://github.com/rust-lang/rust-clippy/pull/7789)
+* Added a new configuration `literal-suffix-style` to enforce a certain style
+ writing [`unseparated_literal_suffix`]
+ [#7726](https://github.com/rust-lang/rust-clippy/pull/7726)
+
+## Rust 1.57
+
+Released 2021-12-02
+
+[7bfc26e...00e31fa](https://github.com/rust-lang/rust-clippy/compare/7bfc26e...00e31fa)
+
+### New Lints
+
+* [`negative_feature_names`]
+ [#7539](https://github.com/rust-lang/rust-clippy/pull/7539)
+* [`redundant_feature_names`]
+ [#7539](https://github.com/rust-lang/rust-clippy/pull/7539)
+* [`mod_module_files`]
+ [#7543](https://github.com/rust-lang/rust-clippy/pull/7543)
+* [`self_named_module_files`]
+ [#7543](https://github.com/rust-lang/rust-clippy/pull/7543)
+* [`manual_split_once`]
+ [#7565](https://github.com/rust-lang/rust-clippy/pull/7565)
+* [`derivable_impls`]
+ [#7570](https://github.com/rust-lang/rust-clippy/pull/7570)
+* [`needless_option_as_deref`]
+ [#7596](https://github.com/rust-lang/rust-clippy/pull/7596)
+* [`iter_not_returning_iterator`]
+ [#7610](https://github.com/rust-lang/rust-clippy/pull/7610)
+* [`same_name_method`]
+ [#7653](https://github.com/rust-lang/rust-clippy/pull/7653)
+* [`manual_assert`] [#7669](https://github.com/rust-lang/rust-clippy/pull/7669)
+* [`non_send_fields_in_send_ty`]
+ [#7709](https://github.com/rust-lang/rust-clippy/pull/7709)
+* [`equatable_if_let`]
+ [#7762](https://github.com/rust-lang/rust-clippy/pull/7762)
+
+### Moves and Deprecations
+
+* Move [`shadow_unrelated`] to `restriction`
+ [#7338](https://github.com/rust-lang/rust-clippy/pull/7338)
+* Move [`option_if_let_else`] to `nursery`
+ [#7568](https://github.com/rust-lang/rust-clippy/pull/7568)
+* Move [`branches_sharing_code`] to `nursery`
+ [#7595](https://github.com/rust-lang/rust-clippy/pull/7595)
+* Rename `if_let_some_result` to [`match_result_ok`] which now also handles
+ `while let` cases [#7608](https://github.com/rust-lang/rust-clippy/pull/7608)
+* Move [`many_single_char_names`] to `pedantic`
+ [#7671](https://github.com/rust-lang/rust-clippy/pull/7671)
+* Move [`float_cmp`] to `pedantic`
+ [#7692](https://github.com/rust-lang/rust-clippy/pull/7692)
+* Rename `box_vec` to [`box_collection`] and lint on more general cases
+ [#7693](https://github.com/rust-lang/rust-clippy/pull/7693)
+* Uplift `invalid_atomic_ordering` to rustc
+ [rust-lang/rust#84039](https://github.com/rust-lang/rust/pull/84039)
+
+### Enhancements
+
+* Rewrite the `shadow*` lints, so that they find a lot more shadows and are not
+ limited to certain patterns
+ [#7338](https://github.com/rust-lang/rust-clippy/pull/7338)
+* The `avoid-breaking-exported-api` configuration now also works for
+ [`box_collection`], [`redundant_allocation`], [`rc_buffer`], [`vec_box`],
+ [`option_option`], [`linkedlist`], [`rc_mutex`]
+ [#7560](https://github.com/rust-lang/rust-clippy/pull/7560)
+* [`unnecessary_unwrap`]: Now also checks for `expect`s
+ [#7584](https://github.com/rust-lang/rust-clippy/pull/7584)
+* [`disallowed_methods`]: Allow adding a reason that will be displayed with the
+ lint message
+ [#7621](https://github.com/rust-lang/rust-clippy/pull/7621)
+* [`approx_constant`]: Now checks the MSRV for `LOG10_2` and `LOG2_10`
+ [#7629](https://github.com/rust-lang/rust-clippy/pull/7629)
+* [`approx_constant`]: Add `TAU`
+ [#7642](https://github.com/rust-lang/rust-clippy/pull/7642)
+* [`needless_borrow`]: Now also lints on needless mutable borrows
+ [#7657](https://github.com/rust-lang/rust-clippy/pull/7657)
+* [`missing_safety_doc`]: Now also lints on unsafe traits
+ [#7734](https://github.com/rust-lang/rust-clippy/pull/7734)
+
+### False Positive Fixes
+
+* [`manual_map`]: No longer lints when the option is borrowed in the match and
+ also consumed in the arm
+ [#7531](https://github.com/rust-lang/rust-clippy/pull/7531)
+* [`filter_next`]: No longer lints if `filter` method is not the
+ `Iterator::filter` method
+ [#7562](https://github.com/rust-lang/rust-clippy/pull/7562)
+* [`manual_flatten`]: No longer lints if expression is used after `if let`
+ [#7566](https://github.com/rust-lang/rust-clippy/pull/7566)
+* [`option_if_let_else`]: Multiple fixes
+ [#7573](https://github.com/rust-lang/rust-clippy/pull/7573)
+ * `break` and `continue` statements local to the would-be closure are
+ allowed
+ * Don't lint in const contexts
+ * Don't lint when yield expressions are used
+ * Don't lint when the captures made by the would-be closure conflict with
+ the other branch
+ * Don't lint when a field of a local is used when the type could be
+ potentially moved from
+ * In some cases, don't lint when scrutinee expression conflicts with the
+ captures of the would-be closure
+* [`redundant_allocation`]: No longer lints on `Box<Box<dyn T>>` which replaces
+ wide pointers with thin pointers
+ [#7592](https://github.com/rust-lang/rust-clippy/pull/7592)
+* [`bool_assert_comparison`]: No longer lints on types that do not implement the
+ `Not` trait with `Output = bool`
+ [#7605](https://github.com/rust-lang/rust-clippy/pull/7605)
+* [`mut_range_bound`]: No longer lints on range bound mutations, that are
+ immediately followed by a `break;`
+ [#7607](https://github.com/rust-lang/rust-clippy/pull/7607)
+* [`mutable_key_type`]: Improve accuracy and document remaining false positives
+ and false negatives
+ [#7640](https://github.com/rust-lang/rust-clippy/pull/7640)
+* [`redundant_closure`]: Rewrite the lint to fix various false positives and
+ false negatives [#7661](https://github.com/rust-lang/rust-clippy/pull/7661)
+* [`large_enum_variant`]: No longer wrongly identifies the second largest
+ variant [#7677](https://github.com/rust-lang/rust-clippy/pull/7677)
+* [`needless_return`]: No longer lints on let-else expressions
+ [#7685](https://github.com/rust-lang/rust-clippy/pull/7685)
+* [`suspicious_else_formatting`]: No longer lints in proc-macros
+ [#7707](https://github.com/rust-lang/rust-clippy/pull/7707)
+* [`excessive_precision`]: No longer lints when in some cases the float was
+ already written in the shortest form
+ [#7722](https://github.com/rust-lang/rust-clippy/pull/7722)
+* [`doc_markdown`]: No longer lints on intra-doc links
+ [#7772](https://github.com/rust-lang/rust-clippy/pull/7772)
+
+### Suggestion Fixes/Improvements
+
+* [`unnecessary_operation`]: Recommend using an `assert!` instead of using a
+ function call in an indexing operation
+ [#7453](https://github.com/rust-lang/rust-clippy/pull/7453)
+* [`manual_split_once`]: Produce semantically equivalent suggestion when
+ `rsplitn` is used [#7663](https://github.com/rust-lang/rust-clippy/pull/7663)
+* [`while_let_on_iterator`]: Produce correct suggestion when using `&mut`
+ [#7690](https://github.com/rust-lang/rust-clippy/pull/7690)
+* [`manual_assert`]: No better handles complex conditions
+ [#7741](https://github.com/rust-lang/rust-clippy/pull/7741)
+* Correctly handle signs in exponents in numeric literals lints
+ [#7747](https://github.com/rust-lang/rust-clippy/pull/7747)
+* [`suspicious_map`]: Now also suggests to use `inspect` as an alternative
+ [#7770](https://github.com/rust-lang/rust-clippy/pull/7770)
+* Drop exponent from suggestion if it is 0 in numeric literals lints
+ [#7774](https://github.com/rust-lang/rust-clippy/pull/7774)
+
+### ICE Fixes
+
+* [`implicit_hasher`]
+ [#7761](https://github.com/rust-lang/rust-clippy/pull/7761)
+
+### Others
+
+* Clippy now uses the 2021
+ [Edition!](https://www.youtube.com/watch?v=q0aNduqb2Ro)
+ [#7664](https://github.com/rust-lang/rust-clippy/pull/7664)
+
+## Rust 1.56
+
+Released 2021-10-21
+
+[74d1561...7bfc26e](https://github.com/rust-lang/rust-clippy/compare/74d1561...7bfc26e)
+
+### New Lints
+
+* [`unwrap_or_else_default`]
+ [#7516](https://github.com/rust-lang/rust-clippy/pull/7516)
+
+### Enhancements
+
+* [`needless_continue`]: Now also lints in `loop { continue; }` case
+ [#7477](https://github.com/rust-lang/rust-clippy/pull/7477)
+* [`disallowed_types`]: Now also primitive types can be disallowed
+ [#7488](https://github.com/rust-lang/rust-clippy/pull/7488)
+* [`manual_swap`]: Now also lints on xor swaps
+ [#7506](https://github.com/rust-lang/rust-clippy/pull/7506)
+* [`map_flatten`]: Now also lints on the `Result` type
+ [#7522](https://github.com/rust-lang/rust-clippy/pull/7522)
+* [`no_effect`]: Now also lints on inclusive ranges
+ [#7556](https://github.com/rust-lang/rust-clippy/pull/7556)
+
+### False Positive Fixes
+
+* [`nonstandard_macro_braces`]: No longer lints on similar named nested macros
+ [#7478](https://github.com/rust-lang/rust-clippy/pull/7478)
+* [`too_many_lines`]: No longer lints in closures to avoid duplicated diagnostics
+ [#7534](https://github.com/rust-lang/rust-clippy/pull/7534)
+* [`similar_names`]: No longer complains about `iter` and `item` being too
+ similar [#7546](https://github.com/rust-lang/rust-clippy/pull/7546)
+
+### Suggestion Fixes/Improvements
+
+* [`similar_names`]: No longer suggests to insert or add an underscore as a fix
+ [#7221](https://github.com/rust-lang/rust-clippy/pull/7221)
+* [`new_without_default`]: No longer shows the full qualified type path when
+ suggesting adding a `Default` implementation
+ [#7493](https://github.com/rust-lang/rust-clippy/pull/7493)
+* [`while_let_on_iterator`]: Now suggests re-borrowing mutable references
+ [#7520](https://github.com/rust-lang/rust-clippy/pull/7520)
+* [`extend_with_drain`]: Improve code suggestion for mutable and immutable
+ references [#7533](https://github.com/rust-lang/rust-clippy/pull/7533)
+* [`trivially_copy_pass_by_ref`]: Now properly handles `Self` type
+ [#7535](https://github.com/rust-lang/rust-clippy/pull/7535)
+* [`never_loop`]: Now suggests using `if let` instead of a `for` loop when
+ applicable [#7541](https://github.com/rust-lang/rust-clippy/pull/7541)
+
+### Documentation Improvements
+
+* Clippy now uses a lint to generate its lint documentation. [Lints all the way
+ down](https://en.wikipedia.org/wiki/Turtles_all_the_way_down).
+ [#7502](https://github.com/rust-lang/rust-clippy/pull/7502)
+* Reworked Clippy's website:
+ [#7172](https://github.com/rust-lang/rust-clippy/issues/7172)
+ [#7279](https://github.com/rust-lang/rust-clippy/pull/7279)
+ * Added applicability information about lints
+ * Added a link to jump into the implementation
+ * Improved loading times
+ * Adapted some styling
+* `cargo clippy --help` now also explains the `--fix` and `--no-deps` flag
+ [#7492](https://github.com/rust-lang/rust-clippy/pull/7492)
+* [`unnested_or_patterns`]: Removed `or_patterns` feature gate in the code
+ example [#7507](https://github.com/rust-lang/rust-clippy/pull/7507)
+
+## Rust 1.55
+
+Released 2021-09-09
+
+[3ae8faf...74d1561](https://github.com/rust-lang/rust-clippy/compare/3ae8faf...74d1561)
+
+### Important Changes
+
+* Stabilized `cargo clippy --fix` :tada:
+ [#7405](https://github.com/rust-lang/rust-clippy/pull/7405)
+
+### New Lints
+
+* [`rc_mutex`]
+ [#7316](https://github.com/rust-lang/rust-clippy/pull/7316)
+* [`nonstandard_macro_braces`]
+ [#7299](https://github.com/rust-lang/rust-clippy/pull/7299)
+* [`strlen_on_c_strings`]
+ [#7243](https://github.com/rust-lang/rust-clippy/pull/7243)
+* [`self_named_constructors`]
+ [#7403](https://github.com/rust-lang/rust-clippy/pull/7403)
+* [`disallowed_script_idents`]
+ [#7400](https://github.com/rust-lang/rust-clippy/pull/7400)
+* [`disallowed_types`]
+ [#7315](https://github.com/rust-lang/rust-clippy/pull/7315)
+* [`missing_enforced_import_renames`]
+ [#7300](https://github.com/rust-lang/rust-clippy/pull/7300)
+* [`extend_with_drain`]
+ [#7270](https://github.com/rust-lang/rust-clippy/pull/7270)
+
+### Moves and Deprecations
+
+* Moved [`from_iter_instead_of_collect`] to `pedantic`
+ [#7375](https://github.com/rust-lang/rust-clippy/pull/7375)
+* Added `suspicious` as a new lint group for *code that is most likely wrong or useless*
+ [#7350](https://github.com/rust-lang/rust-clippy/pull/7350)
+ * Moved [`blanket_clippy_restriction_lints`] to `suspicious`
+ * Moved [`empty_loop`] to `suspicious`
+ * Moved [`eval_order_dependence`] to `suspicious`
+ * Moved [`float_equality_without_abs`] to `suspicious`
+ * Moved [`for_loops_over_fallibles`] to `suspicious`
+ * Moved [`misrefactored_assign_op`] to `suspicious`
+ * Moved [`mut_range_bound`] to `suspicious`
+ * Moved [`mutable_key_type`] to `suspicious`
+ * Moved [`suspicious_arithmetic_impl`] to `suspicious`
+ * Moved [`suspicious_assignment_formatting`] to `suspicious`
+ * Moved [`suspicious_else_formatting`] to `suspicious`
+ * Moved [`suspicious_map`] to `suspicious`
+ * Moved [`suspicious_op_assign_impl`] to `suspicious`
+ * Moved [`suspicious_unary_op_formatting`] to `suspicious`
+
+### Enhancements
+
+* [`while_let_on_iterator`]: Now suggests `&mut iter` inside closures
+ [#7262](https://github.com/rust-lang/rust-clippy/pull/7262)
+* [`doc_markdown`]:
+ * Now detects unbalanced ticks
+ [#7357](https://github.com/rust-lang/rust-clippy/pull/7357)
+ * Add `FreeBSD` to the default configuration as an allowed identifier
+ [#7334](https://github.com/rust-lang/rust-clippy/pull/7334)
+* [`wildcard_enum_match_arm`], [`match_wildcard_for_single_variants`]: Now allows wildcards for enums with unstable
+ or hidden variants
+ [#7407](https://github.com/rust-lang/rust-clippy/pull/7407)
+* [`redundant_allocation`]: Now additionally supports the `Arc<>` type
+ [#7308](https://github.com/rust-lang/rust-clippy/pull/7308)
+* [`blacklisted_name`]: Now allows blacklisted names in test code
+ [#7379](https://github.com/rust-lang/rust-clippy/pull/7379)
+* [`redundant_closure`]: Suggests `&mut` for `FnMut`
+ [#7437](https://github.com/rust-lang/rust-clippy/pull/7437)
+* [`disallowed_methods`], [`disallowed_types`]: The configuration values `disallowed-method` and `disallowed-type`
+ no longer require fully qualified paths
+ [#7345](https://github.com/rust-lang/rust-clippy/pull/7345)
+* [`zst_offset`]: Fixed lint invocation after it was accidentally suppressed
+ [#7396](https://github.com/rust-lang/rust-clippy/pull/7396)
+
+### False Positive Fixes
+
+* [`default_numeric_fallback`]: No longer lints on float literals as function arguments
+ [#7446](https://github.com/rust-lang/rust-clippy/pull/7446)
+* [`use_self`]: No longer lints on type parameters
+ [#7288](https://github.com/rust-lang/rust-clippy/pull/7288)
+* [`unimplemented`]: Now ignores the `assert` and `debug_assert` macros
+ [#7439](https://github.com/rust-lang/rust-clippy/pull/7439)
+* [`branches_sharing_code`]: Now always checks for block expressions
+ [#7462](https://github.com/rust-lang/rust-clippy/pull/7462)
+* [`field_reassign_with_default`]: No longer triggers in macros
+ [#7160](https://github.com/rust-lang/rust-clippy/pull/7160)
+* [`redundant_clone`]: No longer lints on required clones for borrowed data
+ [#7346](https://github.com/rust-lang/rust-clippy/pull/7346)
+* [`default_numeric_fallback`]: No longer triggers in external macros
+ [#7325](https://github.com/rust-lang/rust-clippy/pull/7325)
+* [`needless_bool`]: No longer lints in macros
+ [#7442](https://github.com/rust-lang/rust-clippy/pull/7442)
+* [`useless_format`]: No longer triggers when additional text is being appended
+ [#7442](https://github.com/rust-lang/rust-clippy/pull/7442)
+* [`assertions_on_constants`]: `cfg!(...)` is no longer considered to be a constant
+ [#7319](https://github.com/rust-lang/rust-clippy/pull/7319)
+
+### Suggestion Fixes/Improvements
+
+* [`needless_collect`]: Now show correct lint messages for shadowed values
+ [#7289](https://github.com/rust-lang/rust-clippy/pull/7289)
+* [`wrong_pub_self_convention`]: The deprecated message now suggest the correct configuration value
+ [#7382](https://github.com/rust-lang/rust-clippy/pull/7382)
+* [`semicolon_if_nothing_returned`]: Allow missing semicolon in blocks with only one expression
+ [#7326](https://github.com/rust-lang/rust-clippy/pull/7326)
+
+### ICE Fixes
+
+* [`zero_sized_map_values`]
+ [#7470](https://github.com/rust-lang/rust-clippy/pull/7470)
+* [`redundant_pattern_matching`]
+ [#7471](https://github.com/rust-lang/rust-clippy/pull/7471)
+* [`modulo_one`]
+ [#7473](https://github.com/rust-lang/rust-clippy/pull/7473)
+* [`use_self`]
+ [#7428](https://github.com/rust-lang/rust-clippy/pull/7428)
+
+## Rust 1.54
+
+Released 2021-07-29
+
+[7c7683c...3ae8faf](https://github.com/rust-lang/rust-clippy/compare/7c7683c...3ae8faf)
+
+### New Lints
+
+- [`ref_binding_to_reference`]
+ [#7105](https://github.com/rust-lang/rust-clippy/pull/7105)
+- [`needless_bitwise_bool`]
+ [#7133](https://github.com/rust-lang/rust-clippy/pull/7133)
+- [`unused_async`] [#7225](https://github.com/rust-lang/rust-clippy/pull/7225)
+- [`manual_str_repeat`]
+ [#7265](https://github.com/rust-lang/rust-clippy/pull/7265)
+- [`suspicious_splitn`]
+ [#7292](https://github.com/rust-lang/rust-clippy/pull/7292)
+
+### Moves and Deprecations
+
+- Deprecate `pub_enum_variant_names` and `wrong_pub_self_convention` in favor of
+ the new `avoid-breaking-exported-api` config option (see
+ [Enhancements](#1-54-enhancements))
+ [#7187](https://github.com/rust-lang/rust-clippy/pull/7187)
+- Move [`inconsistent_struct_constructor`] to `pedantic`
+ [#7193](https://github.com/rust-lang/rust-clippy/pull/7193)
+- Move [`needless_borrow`] to `style` (now warn-by-default)
+ [#7254](https://github.com/rust-lang/rust-clippy/pull/7254)
+- Move [`suspicious_operation_groupings`] to `nursery`
+ [#7266](https://github.com/rust-lang/rust-clippy/pull/7266)
+- Move [`semicolon_if_nothing_returned`] to `pedantic`
+ [#7268](https://github.com/rust-lang/rust-clippy/pull/7268)
+
+### Enhancements <a name="1-54-enhancements"></a>
+
+- [`while_let_on_iterator`]: Now also lints in nested loops
+ [#6966](https://github.com/rust-lang/rust-clippy/pull/6966)
+- [`single_char_pattern`]: Now also lints on `strip_prefix` and `strip_suffix`
+ [#7156](https://github.com/rust-lang/rust-clippy/pull/7156)
+- [`needless_collect`]: Now also lints on assignments with type annotations
+ [#7163](https://github.com/rust-lang/rust-clippy/pull/7163)
+- [`if_then_some_else_none`]: Now works with the MSRV config
+ [#7177](https://github.com/rust-lang/rust-clippy/pull/7177)
+- Add `avoid-breaking-exported-api` config option for the lints
+ [`enum_variant_names`], [`large_types_passed_by_value`],
+ [`trivially_copy_pass_by_ref`], [`unnecessary_wraps`],
+ [`upper_case_acronyms`], and [`wrong_self_convention`]. We recommend to set
+ this configuration option to `false` before a major release (1.0/2.0/...) to
+ clean up the API [#7187](https://github.com/rust-lang/rust-clippy/pull/7187)
+- [`needless_collect`]: Now lints on even more data structures
+ [#7188](https://github.com/rust-lang/rust-clippy/pull/7188)
+- [`missing_docs_in_private_items`]: No longer sees `#[<name> = "<value>"]` like
+ attributes as sufficient documentation
+ [#7281](https://github.com/rust-lang/rust-clippy/pull/7281)
+- [`needless_collect`], [`short_circuit_statement`], [`unnecessary_operation`]:
+ Now work as expected when used with `allow`
+ [#7282](https://github.com/rust-lang/rust-clippy/pull/7282)
+
+### False Positive Fixes
+
+- [`implicit_return`]: Now takes all diverging functions in account to avoid
+ false positives [#6951](https://github.com/rust-lang/rust-clippy/pull/6951)
+- [`while_let_on_iterator`]: No longer lints when the iterator is a struct field
+ and the struct is used in the loop
+ [#6966](https://github.com/rust-lang/rust-clippy/pull/6966)
+- [`multiple_inherent_impl`]: No longer lints with generic arguments
+ [#7089](https://github.com/rust-lang/rust-clippy/pull/7089)
+- [`comparison_chain`]: No longer lints in a `const` context
+ [#7118](https://github.com/rust-lang/rust-clippy/pull/7118)
+- [`while_immutable_condition`]: Fix false positive where mutation in the loop
+ variable wasn't picked up
+ [#7144](https://github.com/rust-lang/rust-clippy/pull/7144)
+- [`default_trait_access`]: No longer lints in macros
+ [#7150](https://github.com/rust-lang/rust-clippy/pull/7150)
+- [`needless_question_mark`]: No longer lints when the inner value is implicitly
+ dereferenced [#7165](https://github.com/rust-lang/rust-clippy/pull/7165)
+- [`unused_unit`]: No longer lints when multiple macro contexts are involved
+ [#7167](https://github.com/rust-lang/rust-clippy/pull/7167)
+- [`eval_order_dependence`]: Fix false positive in async context
+ [#7174](https://github.com/rust-lang/rust-clippy/pull/7174)
+- [`unnecessary_filter_map`]: No longer lints if the `filter_map` changes the
+ type [#7175](https://github.com/rust-lang/rust-clippy/pull/7175)
+- [`wrong_self_convention`]: No longer lints in trait implementations of
+ non-`Copy` types [#7182](https://github.com/rust-lang/rust-clippy/pull/7182)
+- [`suboptimal_flops`]: No longer lints on `powi(2)`
+ [#7201](https://github.com/rust-lang/rust-clippy/pull/7201)
+- [`wrong_self_convention`]: No longer lints if there is no implicit `self`
+ [#7215](https://github.com/rust-lang/rust-clippy/pull/7215)
+- [`option_if_let_else`]: No longer lints on `else if let` pattern
+ [#7216](https://github.com/rust-lang/rust-clippy/pull/7216)
+- [`use_self`], [`useless_conversion`]: Fix false positives when generic
+ arguments are involved
+ [#7223](https://github.com/rust-lang/rust-clippy/pull/7223)
+- [`manual_unwrap_or`]: Fix false positive with deref coercion
+ [#7233](https://github.com/rust-lang/rust-clippy/pull/7233)
+- [`similar_names`]: No longer lints on `wparam`/`lparam`
+ [#7255](https://github.com/rust-lang/rust-clippy/pull/7255)
+- [`redundant_closure`]: No longer lints on using the `vec![]` macro in a
+ closure [#7263](https://github.com/rust-lang/rust-clippy/pull/7263)
+
+### Suggestion Fixes/Improvements
+
+- [`implicit_return`]
+ [#6951](https://github.com/rust-lang/rust-clippy/pull/6951)
+ - Fix suggestion for async functions
+ - Improve suggestion with macros
+ - Suggest to change `break` to `return` when appropriate
+- [`while_let_on_iterator`]: Now suggests `&mut iter` when necessary
+ [#6966](https://github.com/rust-lang/rust-clippy/pull/6966)
+- [`match_single_binding`]: Improve suggestion when match scrutinee has side
+ effects [#7095](https://github.com/rust-lang/rust-clippy/pull/7095)
+- [`needless_borrow`]: Now suggests to also change usage sites as needed
+ [#7105](https://github.com/rust-lang/rust-clippy/pull/7105)
+- [`write_with_newline`]: Improve suggestion when only `\n` is written to the
+ buffer [#7183](https://github.com/rust-lang/rust-clippy/pull/7183)
+- [`from_iter_instead_of_collect`]: The suggestion is now auto applicable also
+ when a `<_ as Trait>::_` is involved
+ [#7264](https://github.com/rust-lang/rust-clippy/pull/7264)
+- [`not_unsafe_ptr_arg_deref`]: Improved error message
+ [#7294](https://github.com/rust-lang/rust-clippy/pull/7294)
+
+### ICE Fixes
+
+- Fix ICE when running Clippy on `libstd`
+ [#7140](https://github.com/rust-lang/rust-clippy/pull/7140)
+- [`implicit_return`]
+ [#7242](https://github.com/rust-lang/rust-clippy/pull/7242)
+
+## Rust 1.53
+
+Released 2021-06-17
+
+[6ed6f1e...7c7683c](https://github.com/rust-lang/rust-clippy/compare/6ed6f1e...7c7683c)
+
+### New Lints
+
+* [`option_filter_map`]
+ [#6342](https://github.com/rust-lang/rust-clippy/pull/6342)
+* [`branches_sharing_code`]
+ [#6463](https://github.com/rust-lang/rust-clippy/pull/6463)
+* [`needless_for_each`]
+ [#6706](https://github.com/rust-lang/rust-clippy/pull/6706)
+* [`if_then_some_else_none`]
+ [#6859](https://github.com/rust-lang/rust-clippy/pull/6859)
+* [`non_octal_unix_permissions`]
+ [#7001](https://github.com/rust-lang/rust-clippy/pull/7001)
+* [`unnecessary_self_imports`]
+ [#7072](https://github.com/rust-lang/rust-clippy/pull/7072)
+* [`bool_assert_comparison`]
+ [#7083](https://github.com/rust-lang/rust-clippy/pull/7083)
+* [`cloned_instead_of_copied`]
+ [#7098](https://github.com/rust-lang/rust-clippy/pull/7098)
+* [`flat_map_option`]
+ [#7101](https://github.com/rust-lang/rust-clippy/pull/7101)
+
+### Moves and Deprecations
+
+* Deprecate [`filter_map`] lint
+ [#7059](https://github.com/rust-lang/rust-clippy/pull/7059)
+* Move [`transmute_ptr_to_ptr`] to `pedantic`
+ [#7102](https://github.com/rust-lang/rust-clippy/pull/7102)
+
+### Enhancements
+
+* [`mem_replace_with_default`]: Also lint on common std constructors
+ [#6820](https://github.com/rust-lang/rust-clippy/pull/6820)
+* [`wrong_self_convention`]: Also lint on `to_*_mut` methods
+ [#6828](https://github.com/rust-lang/rust-clippy/pull/6828)
+* [`wildcard_enum_match_arm`], [`match_wildcard_for_single_variants`]:
+ [#6863](https://github.com/rust-lang/rust-clippy/pull/6863)
+ * Attempt to find a common path prefix in suggestion
+ * Don't lint on `Option` and `Result`
+ * Consider `Self` prefix
+* [`explicit_deref_methods`]: Also lint on chained `deref` calls
+ [#6865](https://github.com/rust-lang/rust-clippy/pull/6865)
+* [`or_fun_call`]: Also lint on `unsafe` blocks
+ [#6928](https://github.com/rust-lang/rust-clippy/pull/6928)
+* [`vec_box`], [`linkedlist`], [`option_option`]: Also lint in `const` and
+ `static` items [#6938](https://github.com/rust-lang/rust-clippy/pull/6938)
+* [`search_is_some`]: Also check for `is_none`
+ [#6942](https://github.com/rust-lang/rust-clippy/pull/6942)
+* [`string_lit_as_bytes`]: Also lint on `into_bytes`
+ [#6959](https://github.com/rust-lang/rust-clippy/pull/6959)
+* [`len_without_is_empty`]: Also lint if function signatures of `len` and
+ `is_empty` don't match
+ [#6980](https://github.com/rust-lang/rust-clippy/pull/6980)
+* [`redundant_pattern_matching`]: Also lint if the pattern is a `&` pattern
+ [#6991](https://github.com/rust-lang/rust-clippy/pull/6991)
+* [`clone_on_copy`]: Also lint on chained method calls taking `self` by value
+ [#7000](https://github.com/rust-lang/rust-clippy/pull/7000)
+* [`missing_panics_doc`]: Also lint on `assert_eq!` and `assert_ne!`
+ [#7029](https://github.com/rust-lang/rust-clippy/pull/7029)
+* [`needless_return`]: Also lint in `async` functions
+ [#7067](https://github.com/rust-lang/rust-clippy/pull/7067)
+* [`unused_io_amount`]: Also lint on expressions like `_.read().ok()?`
+ [#7100](https://github.com/rust-lang/rust-clippy/pull/7100)
+* [`iter_cloned_collect`]: Also lint on large arrays, since const-generics are
+ now stable [#7138](https://github.com/rust-lang/rust-clippy/pull/7138)
+
+### False Positive Fixes
+
+* [`upper_case_acronyms`]: No longer lints on public items
+ [#6805](https://github.com/rust-lang/rust-clippy/pull/6805)
+* [`suspicious_map`]: No longer lints when side effects may occur inside the
+ `map` call [#6831](https://github.com/rust-lang/rust-clippy/pull/6831)
+* [`manual_map`], [`manual_unwrap_or`]: No longer lints in `const` functions
+ [#6917](https://github.com/rust-lang/rust-clippy/pull/6917)
+* [`wrong_self_convention`]: Now respects `Copy` types
+ [#6924](https://github.com/rust-lang/rust-clippy/pull/6924)
+* [`needless_question_mark`]: No longer lints if the `?` and the `Some(..)` come
+ from different macro contexts [#6935](https://github.com/rust-lang/rust-clippy/pull/6935)
+* [`map_entry`]: Better detect if the entry API can be used
+ [#6937](https://github.com/rust-lang/rust-clippy/pull/6937)
+* [`or_fun_call`]: No longer lints on some `len` function calls
+ [#6950](https://github.com/rust-lang/rust-clippy/pull/6950)
+* [`new_ret_no_self`]: No longer lints when `Self` is returned with different
+ generic arguments [#6952](https://github.com/rust-lang/rust-clippy/pull/6952)
+* [`upper_case_acronyms`]: No longer lints on public items
+ [#6981](https://github.com/rust-lang/rust-clippy/pull/6981)
+* [`explicit_into_iter_loop`]: Only lint when `into_iter` is an implementation
+ of `IntoIterator` [#6982](https://github.com/rust-lang/rust-clippy/pull/6982)
+* [`expl_impl_clone_on_copy`]: Take generic constraints into account before
+ suggesting to use `derive` instead
+ [#6993](https://github.com/rust-lang/rust-clippy/pull/6993)
+* [`missing_panics_doc`]: No longer lints when only debug-assertions are used
+ [#6996](https://github.com/rust-lang/rust-clippy/pull/6996)
+* [`clone_on_copy`]: Only lint when using the `Clone` trait
+ [#7000](https://github.com/rust-lang/rust-clippy/pull/7000)
+* [`wrong_self_convention`]: No longer lints inside a trait implementation
+ [#7002](https://github.com/rust-lang/rust-clippy/pull/7002)
+* [`redundant_clone`]: No longer lints when the cloned value is modified while
+ the clone is in use
+ [#7011](https://github.com/rust-lang/rust-clippy/pull/7011)
+* [`same_item_push`]: No longer lints if the `Vec` is used in the loop body
+ [#7018](https://github.com/rust-lang/rust-clippy/pull/7018)
+* [`cargo_common_metadata`]: Remove author requirement
+ [#7026](https://github.com/rust-lang/rust-clippy/pull/7026)
+* [`panic_in_result_fn`]: No longer lints on `debug_assert` family
+ [#7060](https://github.com/rust-lang/rust-clippy/pull/7060)
+* [`panic`]: No longer wrongfully lints on `debug_assert` with message
+ [#7063](https://github.com/rust-lang/rust-clippy/pull/7063)
+* [`wrong_self_convention`]: No longer lints in trait implementations where no
+ `self` is involved [#7064](https://github.com/rust-lang/rust-clippy/pull/7064)
+* [`missing_const_for_fn`]: No longer lints when unstable `const` function is
+ involved [#7076](https://github.com/rust-lang/rust-clippy/pull/7076)
+* [`suspicious_else_formatting`]: Allow Allman style braces
+ [#7087](https://github.com/rust-lang/rust-clippy/pull/7087)
+* [`inconsistent_struct_constructor`]: No longer lints in macros
+ [#7097](https://github.com/rust-lang/rust-clippy/pull/7097)
+* [`single_component_path_imports`]: No longer lints on macro re-exports
+ [#7120](https://github.com/rust-lang/rust-clippy/pull/7120)
+
+### Suggestion Fixes/Improvements
+
+* [`redundant_pattern_matching`]: Add a note when applying this lint would
+ change the drop order
+ [#6568](https://github.com/rust-lang/rust-clippy/pull/6568)
+* [`write_literal`], [`print_literal`]: Add auto-applicable suggestion
+ [#6821](https://github.com/rust-lang/rust-clippy/pull/6821)
+* [`manual_map`]: Fix suggestion for complex `if let ... else` chains
+ [#6856](https://github.com/rust-lang/rust-clippy/pull/6856)
+* [`inconsistent_struct_constructor`]: Make lint description and message clearer
+ [#6892](https://github.com/rust-lang/rust-clippy/pull/6892)
+* [`map_entry`]: Now suggests `or_insert`, `insert_with` or `match _.entry(_)`
+ as appropriate [#6937](https://github.com/rust-lang/rust-clippy/pull/6937)
+* [`manual_flatten`]: Suggest to insert `copied` if necessary
+ [#6962](https://github.com/rust-lang/rust-clippy/pull/6962)
+* [`redundant_slicing`]: Fix suggestion when a re-borrow might be required or
+ when the value is from a macro call
+ [#6975](https://github.com/rust-lang/rust-clippy/pull/6975)
+* [`match_wildcard_for_single_variants`]: Fix suggestion for hidden variant
+ [#6988](https://github.com/rust-lang/rust-clippy/pull/6988)
+* [`clone_on_copy`]: Correct suggestion when the cloned value is a macro call
+ [#7000](https://github.com/rust-lang/rust-clippy/pull/7000)
+* [`manual_map`]: Fix suggestion at the end of an if chain
+ [#7004](https://github.com/rust-lang/rust-clippy/pull/7004)
+* Fix needless parenthesis output in multiple lint suggestions
+ [#7013](https://github.com/rust-lang/rust-clippy/pull/7013)
+* [`needless_collect`]: Better explanation in the lint message
+ [#7020](https://github.com/rust-lang/rust-clippy/pull/7020)
+* [`useless_vec`]: Now considers mutability
+ [#7036](https://github.com/rust-lang/rust-clippy/pull/7036)
+* [`useless_format`]: Wrap the content in braces if necessary
+ [#7092](https://github.com/rust-lang/rust-clippy/pull/7092)
+* [`single_match`]: Don't suggest an equality check for types which don't
+ implement `PartialEq`
+ [#7093](https://github.com/rust-lang/rust-clippy/pull/7093)
+* [`from_over_into`]: Mention type in help message
+ [#7099](https://github.com/rust-lang/rust-clippy/pull/7099)
+* [`manual_unwrap_or`]: Fix invalid code suggestion due to a macro call
+ [#7136](https://github.com/rust-lang/rust-clippy/pull/7136)
+
+### ICE Fixes
+
+* [`macro_use_imports`]
+ [#7022](https://github.com/rust-lang/rust-clippy/pull/7022)
+* [`missing_panics_doc`]
+ [#7034](https://github.com/rust-lang/rust-clippy/pull/7034)
+* [`tabs_in_doc_comments`]
+ [#7039](https://github.com/rust-lang/rust-clippy/pull/7039)
+* [`missing_const_for_fn`]
+ [#7128](https://github.com/rust-lang/rust-clippy/pull/7128)
+
+### Others
+
+* [Clippy's lint
+ list](https://rust-lang.github.io/rust-clippy/master/index.html) now supports
+ themes [#7030](https://github.com/rust-lang/rust-clippy/pull/7030)
+* Lints that were uplifted to `rustc` now mention the new `rustc` name in the
+ deprecation warning
+ [#7056](https://github.com/rust-lang/rust-clippy/pull/7056)
+
+## Rust 1.52
+
+Released 2021-05-06
+
+[3e41797...6ed6f1e](https://github.com/rust-lang/rust-clippy/compare/3e41797...6ed6f1e)
+
+### New Lints
+
+* [`from_str_radix_10`]
+ [#6717](https://github.com/rust-lang/rust-clippy/pull/6717)
+* [`implicit_clone`]
+ [#6730](https://github.com/rust-lang/rust-clippy/pull/6730)
+* [`semicolon_if_nothing_returned`]
+ [#6681](https://github.com/rust-lang/rust-clippy/pull/6681)
+* [`manual_flatten`]
+ [#6646](https://github.com/rust-lang/rust-clippy/pull/6646)
+* [`inconsistent_struct_constructor`]
+ [#6769](https://github.com/rust-lang/rust-clippy/pull/6769)
+* [`iter_count`]
+ [#6791](https://github.com/rust-lang/rust-clippy/pull/6791)
+* [`default_numeric_fallback`]
+ [#6662](https://github.com/rust-lang/rust-clippy/pull/6662)
+* [`bytes_nth`]
+ [#6695](https://github.com/rust-lang/rust-clippy/pull/6695)
+* [`filter_map_identity`]
+ [#6685](https://github.com/rust-lang/rust-clippy/pull/6685)
+* [`manual_map`]
+ [#6573](https://github.com/rust-lang/rust-clippy/pull/6573)
+
+### Moves and Deprecations
+
+* Moved [`upper_case_acronyms`] to `pedantic`
+ [#6775](https://github.com/rust-lang/rust-clippy/pull/6775)
+* Moved [`manual_map`] to `nursery`
+ [#6796](https://github.com/rust-lang/rust-clippy/pull/6796)
+* Moved [`unnecessary_wraps`] to `pedantic`
+ [#6765](https://github.com/rust-lang/rust-clippy/pull/6765)
+* Moved [`trivial_regex`] to `nursery`
+ [#6696](https://github.com/rust-lang/rust-clippy/pull/6696)
+* Moved [`naive_bytecount`] to `pedantic`
+ [#6825](https://github.com/rust-lang/rust-clippy/pull/6825)
+* Moved [`upper_case_acronyms`] to `style`
+ [#6788](https://github.com/rust-lang/rust-clippy/pull/6788)
+* Moved [`manual_map`] to `style`
+ [#6801](https://github.com/rust-lang/rust-clippy/pull/6801)
+
+### Enhancements
+
+* [`disallowed_methods`]: Now supports functions in addition to methods
+ [#6674](https://github.com/rust-lang/rust-clippy/pull/6674)
+* [`upper_case_acronyms`]: Added a new configuration `upper-case-acronyms-aggressive` to
+ trigger the lint if there is more than one uppercase character next to each other
+ [#6788](https://github.com/rust-lang/rust-clippy/pull/6788)
+* [`collapsible_match`]: Now supports block comparison with different value names
+ [#6754](https://github.com/rust-lang/rust-clippy/pull/6754)
+* [`unnecessary_wraps`]: Will now suggest removing unnecessary wrapped return unit type, like `Option<()>`
+ [#6665](https://github.com/rust-lang/rust-clippy/pull/6665)
+* Improved value usage detection in closures
+ [#6698](https://github.com/rust-lang/rust-clippy/pull/6698)
+
+### False Positive Fixes
+
+* [`use_self`]: No longer lints in macros
+ [#6833](https://github.com/rust-lang/rust-clippy/pull/6833)
+* [`use_self`]: Fixed multiple false positives for: generics, associated types and derive implementations
+ [#6179](https://github.com/rust-lang/rust-clippy/pull/6179)
+* [`missing_inline_in_public_items`]: No longer lints for procedural macros
+ [#6814](https://github.com/rust-lang/rust-clippy/pull/6814)
+* [`inherent_to_string`]: No longer lints on functions with function generics
+ [#6771](https://github.com/rust-lang/rust-clippy/pull/6771)
+* [`doc_markdown`]: Add `OpenDNS` to the default configuration as an allowed identifier
+ [#6783](https://github.com/rust-lang/rust-clippy/pull/6783)
+* [`missing_panics_doc`]: No longer lints on [`unreachable!`](https://doc.rust-lang.org/std/macro.unreachable.html)
+ [#6700](https://github.com/rust-lang/rust-clippy/pull/6700)
+* [`collapsible_if`]: No longer lints on if statements with attributes
+ [#6701](https://github.com/rust-lang/rust-clippy/pull/6701)
+* [`match_same_arms`]: Only considers empty blocks as equal if the tokens contained are the same
+ [#6843](https://github.com/rust-lang/rust-clippy/pull/6843)
+* [`redundant_closure`]: Now ignores macros
+ [#6871](https://github.com/rust-lang/rust-clippy/pull/6871)
+* [`manual_map`]: Fixed false positives when control flow statements like `return`, `break` etc. are used
+ [#6801](https://github.com/rust-lang/rust-clippy/pull/6801)
+* [`vec_init_then_push`]: Fixed false positives for loops and if statements
+ [#6697](https://github.com/rust-lang/rust-clippy/pull/6697)
+* [`len_without_is_empty`]: Will now consider multiple impl blocks and `#[allow]` on
+ the `len` method as well as the type definition.
+ [#6853](https://github.com/rust-lang/rust-clippy/pull/6853)
+* [`let_underscore_drop`]: Only lints on types which implement `Drop`
+ [#6682](https://github.com/rust-lang/rust-clippy/pull/6682)
+* [`unit_arg`]: No longer lints on unit arguments when they come from a path expression.
+ [#6601](https://github.com/rust-lang/rust-clippy/pull/6601)
+* [`cargo_common_metadata`]: No longer lints if
+ [`publish = false`](https://doc.rust-lang.org/cargo/reference/manifest.html#the-publish-field)
+ is defined in the manifest
+ [#6650](https://github.com/rust-lang/rust-clippy/pull/6650)
+
+### Suggestion Fixes/Improvements
+
+* [`collapsible_match`]: Fixed lint message capitalization
+ [#6766](https://github.com/rust-lang/rust-clippy/pull/6766)
+* [`or_fun_call`]: Improved suggestions for `or_insert(vec![])`
+ [#6790](https://github.com/rust-lang/rust-clippy/pull/6790)
+* [`manual_map`]: No longer expands macros in the suggestions
+ [#6801](https://github.com/rust-lang/rust-clippy/pull/6801)
+* Aligned Clippy's lint messages with the rustc dev guide
+ [#6787](https://github.com/rust-lang/rust-clippy/pull/6787)
+
+### ICE Fixes
+
+* [`zero_sized_map_values`]
+ [#6866](https://github.com/rust-lang/rust-clippy/pull/6866)
+
+### Documentation Improvements
+
+* [`useless_format`]: Improved the documentation example
+ [#6854](https://github.com/rust-lang/rust-clippy/pull/6854)
+* Clippy's [`README.md`]: Includes a new subsection on running Clippy as a rustc wrapper
+ [#6782](https://github.com/rust-lang/rust-clippy/pull/6782)
+
+### Others
+* Running `cargo clippy` after `cargo check` now works as expected
+ (`cargo clippy` and `cargo check` no longer shares the same build cache)
+ [#6687](https://github.com/rust-lang/rust-clippy/pull/6687)
+* Cargo now re-runs Clippy if arguments after `--` provided to `cargo clippy` are changed.
+ [#6834](https://github.com/rust-lang/rust-clippy/pull/6834)
+* Extracted Clippy's `utils` module into the new `clippy_utils` crate
+ [#6756](https://github.com/rust-lang/rust-clippy/pull/6756)
+* Clippy lintcheck tool improvements
+ [#6800](https://github.com/rust-lang/rust-clippy/pull/6800)
+ [#6735](https://github.com/rust-lang/rust-clippy/pull/6735)
+ [#6764](https://github.com/rust-lang/rust-clippy/pull/6764)
+ [#6708](https://github.com/rust-lang/rust-clippy/pull/6708)
+ [#6780](https://github.com/rust-lang/rust-clippy/pull/6780)
+ [#6686](https://github.com/rust-lang/rust-clippy/pull/6686)
+
+## Rust 1.51
+
+Released 2021-03-25
+
+[4911ab1...3e41797](https://github.com/rust-lang/rust-clippy/compare/4911ab1...3e41797)
+
+### New Lints
+
+* [`upper_case_acronyms`]
+ [#6475](https://github.com/rust-lang/rust-clippy/pull/6475)
+* [`from_over_into`] [#6476](https://github.com/rust-lang/rust-clippy/pull/6476)
+* [`case_sensitive_file_extension_comparisons`]
+ [#6500](https://github.com/rust-lang/rust-clippy/pull/6500)
+* [`needless_question_mark`]
+ [#6507](https://github.com/rust-lang/rust-clippy/pull/6507)
+* [`missing_panics_doc`]
+ [#6523](https://github.com/rust-lang/rust-clippy/pull/6523)
+* [`redundant_slicing`]
+ [#6528](https://github.com/rust-lang/rust-clippy/pull/6528)
+* [`vec_init_then_push`]
+ [#6538](https://github.com/rust-lang/rust-clippy/pull/6538)
+* [`ptr_as_ptr`] [#6542](https://github.com/rust-lang/rust-clippy/pull/6542)
+* [`collapsible_else_if`] (split out from `collapsible_if`)
+ [#6544](https://github.com/rust-lang/rust-clippy/pull/6544)
+* [`inspect_for_each`] [#6577](https://github.com/rust-lang/rust-clippy/pull/6577)
+* [`manual_filter_map`]
+ [#6591](https://github.com/rust-lang/rust-clippy/pull/6591)
+* [`exhaustive_enums`]
+ [#6617](https://github.com/rust-lang/rust-clippy/pull/6617)
+* [`exhaustive_structs`]
+ [#6617](https://github.com/rust-lang/rust-clippy/pull/6617)
+
+### Moves and Deprecations
+
+* Replace [`find_map`] with [`manual_find_map`]
+ [#6591](https://github.com/rust-lang/rust-clippy/pull/6591)
+* `unknown_clippy_lints` Now integrated in the `unknown_lints` rustc lint
+ [#6653](https://github.com/rust-lang/rust-clippy/pull/6653)
+
+### Enhancements
+
+* [`ptr_arg`] Now also suggests to use `&Path` instead of `&PathBuf`
+ [#6506](https://github.com/rust-lang/rust-clippy/pull/6506)
+* [`cast_ptr_alignment`] Also lint when the `pointer::cast` method is used
+ [#6557](https://github.com/rust-lang/rust-clippy/pull/6557)
+* [`collapsible_match`] Now also deals with `&` and `*` operators in the `match`
+ scrutinee [#6619](https://github.com/rust-lang/rust-clippy/pull/6619)
+
+### False Positive Fixes
+
+* [`similar_names`] Ignore underscore prefixed names
+ [#6403](https://github.com/rust-lang/rust-clippy/pull/6403)
+* [`print_literal`] and [`write_literal`] No longer lint numeric literals
+ [#6408](https://github.com/rust-lang/rust-clippy/pull/6408)
+* [`large_enum_variant`] No longer lints in external macros
+ [#6485](https://github.com/rust-lang/rust-clippy/pull/6485)
+* [`empty_enum`] Only lint if `never_type` feature is enabled
+ [#6513](https://github.com/rust-lang/rust-clippy/pull/6513)
+* [`field_reassign_with_default`] No longer lints in macros
+ [#6553](https://github.com/rust-lang/rust-clippy/pull/6553)
+* [`size_of_in_element_count`] No longer lints when dividing by element size
+ [#6578](https://github.com/rust-lang/rust-clippy/pull/6578)
+* [`needless_return`] No longer lints in macros
+ [#6586](https://github.com/rust-lang/rust-clippy/pull/6586)
+* [`match_overlapping_arm`] No longer lint when first arm is completely included
+ in second arm [#6603](https://github.com/rust-lang/rust-clippy/pull/6603)
+* [`doc_markdown`] Add `WebGL` to the default configuration as an allowed
+ identifier [#6605](https://github.com/rust-lang/rust-clippy/pull/6605)
+
+### Suggestion Fixes/Improvements
+
+* [`field_reassign_with_default`] Don't expand macro in lint suggestion
+ [#6531](https://github.com/rust-lang/rust-clippy/pull/6531)
+* [`match_like_matches_macro`] Strip references in suggestion
+ [#6532](https://github.com/rust-lang/rust-clippy/pull/6532)
+* [`single_match`] Suggest `if` over `if let` when possible
+ [#6574](https://github.com/rust-lang/rust-clippy/pull/6574)
+* `ref_in_deref` Use parentheses correctly in suggestion
+ [#6609](https://github.com/rust-lang/rust-clippy/pull/6609)
+* [`stable_sort_primitive`] Clarify error message
+ [#6611](https://github.com/rust-lang/rust-clippy/pull/6611)
+
+### ICE Fixes
+
+* [`zero_sized_map_values`]
+ [#6582](https://github.com/rust-lang/rust-clippy/pull/6582)
+
+### Documentation Improvements
+
+* Improve search performance on the Clippy website and make it possible to
+ directly search for lints on the GitHub issue tracker
+ [#6483](https://github.com/rust-lang/rust-clippy/pull/6483)
+* Clean up `README.md` by removing outdated paragraph
+ [#6488](https://github.com/rust-lang/rust-clippy/pull/6488)
+* [`await_holding_refcell_ref`] and [`await_holding_lock`]
+ [#6585](https://github.com/rust-lang/rust-clippy/pull/6585)
+* [`as_conversions`] [#6608](https://github.com/rust-lang/rust-clippy/pull/6608)
+
+### Others
+
+* Clippy now has a [Roadmap] for 2021. If you like to get involved in a bigger
+ project, take a look at the [Roadmap project page]. All issues listed there
+ are actively mentored
+ [#6462](https://github.com/rust-lang/rust-clippy/pull/6462)
+* The Clippy version number now corresponds to the Rust version number
+ [#6526](https://github.com/rust-lang/rust-clippy/pull/6526)
+* Fix oversight which caused Clippy to lint deps in some environments, where
+ `CLIPPY_TESTS=true` was set somewhere
+ [#6575](https://github.com/rust-lang/rust-clippy/pull/6575)
+* Add `cargo dev-lintcheck` tool to the Clippy Dev Tool
+ [#6469](https://github.com/rust-lang/rust-clippy/pull/6469)
+
+[Roadmap]: https://github.com/rust-lang/rust-clippy/blob/master/doc/roadmap-2021.md
+[Roadmap project page]: https://github.com/rust-lang/rust-clippy/projects/3
+
+## Rust 1.50
+
+Released 2021-02-11
+
+[b20d4c1...4bd77a1](https://github.com/rust-lang/rust-clippy/compare/b20d4c1...4bd77a1)
+
+### New Lints
+
+* [`suspicious_operation_groupings`] [#6086](https://github.com/rust-lang/rust-clippy/pull/6086)
+* [`size_of_in_element_count`] [#6394](https://github.com/rust-lang/rust-clippy/pull/6394)
+* [`unnecessary_wraps`] [#6070](https://github.com/rust-lang/rust-clippy/pull/6070)
+* [`let_underscore_drop`] [#6305](https://github.com/rust-lang/rust-clippy/pull/6305)
+* [`collapsible_match`] [#6402](https://github.com/rust-lang/rust-clippy/pull/6402)
+* [`redundant_else`] [#6330](https://github.com/rust-lang/rust-clippy/pull/6330)
+* [`zero_sized_map_values`] [#6218](https://github.com/rust-lang/rust-clippy/pull/6218)
+* [`print_stderr`] [#6367](https://github.com/rust-lang/rust-clippy/pull/6367)
+* [`string_from_utf8_as_bytes`] [#6134](https://github.com/rust-lang/rust-clippy/pull/6134)
+
+### Moves and Deprecations
+
+* Previously deprecated [`str_to_string`] and [`string_to_string`] have been un-deprecated
+ as `restriction` lints [#6333](https://github.com/rust-lang/rust-clippy/pull/6333)
+* Deprecate `panic_params` lint. This is now available in rustc as `non_fmt_panics`
+ [#6351](https://github.com/rust-lang/rust-clippy/pull/6351)
+* Move [`map_err_ignore`] to `restriction`
+ [#6416](https://github.com/rust-lang/rust-clippy/pull/6416)
+* Move [`await_holding_refcell_ref`] to `pedantic`
+ [#6354](https://github.com/rust-lang/rust-clippy/pull/6354)
+* Move [`await_holding_lock`] to `pedantic`
+ [#6354](https://github.com/rust-lang/rust-clippy/pull/6354)
+
+### Enhancements
+
+* Add the `unreadable-literal-lint-fractions` configuration to disable
+ the `unreadable_literal` lint for fractions
+ [#6421](https://github.com/rust-lang/rust-clippy/pull/6421)
+* [`clone_on_copy`]: Now shows the type in the lint message
+ [#6443](https://github.com/rust-lang/rust-clippy/pull/6443)
+* [`redundant_pattern_matching`]: Now also lints on `std::task::Poll`
+ [#6339](https://github.com/rust-lang/rust-clippy/pull/6339)
+* [`redundant_pattern_matching`]: Additionally also lints on `std::net::IpAddr`
+ [#6377](https://github.com/rust-lang/rust-clippy/pull/6377)
+* [`search_is_some`]: Now suggests `contains` instead of `find(foo).is_some()`
+ [#6119](https://github.com/rust-lang/rust-clippy/pull/6119)
+* [`clone_double_ref`]: Now prints the reference type in the lint message
+ [#6442](https://github.com/rust-lang/rust-clippy/pull/6442)
+* [`modulo_one`]: Now also lints on -1.
+ [#6360](https://github.com/rust-lang/rust-clippy/pull/6360)
+* [`empty_loop`]: Now lints no_std crates, too
+ [#6205](https://github.com/rust-lang/rust-clippy/pull/6205)
+* [`or_fun_call`]: Now also lints when indexing `HashMap` or `BTreeMap`
+ [#6267](https://github.com/rust-lang/rust-clippy/pull/6267)
+* [`wrong_self_convention`]: Now also lints in trait definitions
+ [#6316](https://github.com/rust-lang/rust-clippy/pull/6316)
+* [`needless_borrow`]: Print the type in the lint message
+ [#6449](https://github.com/rust-lang/rust-clippy/pull/6449)
+
+[msrv_readme]: https://github.com/rust-lang/rust-clippy#specifying-the-minimum-supported-rust-version
+
+### False Positive Fixes
+
+* [`manual_range_contains`]: No longer lints in `const fn`
+ [#6382](https://github.com/rust-lang/rust-clippy/pull/6382)
+* [`unnecessary_lazy_evaluations`]: No longer lints if closure argument is used
+ [#6370](https://github.com/rust-lang/rust-clippy/pull/6370)
+* [`match_single_binding`]: Now ignores cases with `#[cfg()]` macros
+ [#6435](https://github.com/rust-lang/rust-clippy/pull/6435)
+* [`match_like_matches_macro`]: No longer lints on arms with attributes
+ [#6290](https://github.com/rust-lang/rust-clippy/pull/6290)
+* [`map_clone`]: No longer lints with deref and clone
+ [#6269](https://github.com/rust-lang/rust-clippy/pull/6269)
+* [`map_clone`]: No longer lints in the case of &mut
+ [#6301](https://github.com/rust-lang/rust-clippy/pull/6301)
+* [`needless_update`]: Now ignores `non_exhaustive` structs
+ [#6464](https://github.com/rust-lang/rust-clippy/pull/6464)
+* [`needless_collect`]: No longer lints when a collect is needed multiple times
+ [#6313](https://github.com/rust-lang/rust-clippy/pull/6313)
+* [`unnecessary_cast`] No longer lints cfg-dependent types
+ [#6369](https://github.com/rust-lang/rust-clippy/pull/6369)
+* [`declare_interior_mutable_const`] and [`borrow_interior_mutable_const`]:
+ Both now ignore enums with frozen variants
+ [#6110](https://github.com/rust-lang/rust-clippy/pull/6110)
+* [`field_reassign_with_default`] No longer lint for private fields
+ [#6537](https://github.com/rust-lang/rust-clippy/pull/6537)
+
+
+### Suggestion Fixes/Improvements
+
+* [`vec_box`]: Provide correct type scope suggestion
+ [#6271](https://github.com/rust-lang/rust-clippy/pull/6271)
+* [`manual_range_contains`]: Give correct suggestion when using floats
+ [#6320](https://github.com/rust-lang/rust-clippy/pull/6320)
+* [`unnecessary_lazy_evaluations`]: Don't always mark suggestion as MachineApplicable
+ [#6272](https://github.com/rust-lang/rust-clippy/pull/6272)
+* [`manual_async_fn`]: Improve suggestion formatting
+ [#6294](https://github.com/rust-lang/rust-clippy/pull/6294)
+* [`unnecessary_cast`]: Fix incorrectly formatted float literal suggestion
+ [#6362](https://github.com/rust-lang/rust-clippy/pull/6362)
+
+### ICE Fixes
+
+* Fix a crash in [`from_iter_instead_of_collect`]
+ [#6304](https://github.com/rust-lang/rust-clippy/pull/6304)
+* Fix a silent crash when parsing doc comments in [`needless_doctest_main`]
+ [#6458](https://github.com/rust-lang/rust-clippy/pull/6458)
+
+### Documentation Improvements
+
+* The lint website search has been improved ([#6477](https://github.com/rust-lang/rust-clippy/pull/6477)):
+ * Searching for lints with dashes and spaces is possible now. For example
+ `missing-errors-doc` and `missing errors doc` are now valid aliases for lint names
+ * Improved fuzzy search in lint descriptions
+* Various README improvements
+ [#6287](https://github.com/rust-lang/rust-clippy/pull/6287)
+* Add known problems to [`comparison_chain`] documentation
+ [#6390](https://github.com/rust-lang/rust-clippy/pull/6390)
+* Fix example used in [`cargo_common_metadata`]
+ [#6293](https://github.com/rust-lang/rust-clippy/pull/6293)
+* Improve [`map_clone`] documentation
+ [#6340](https://github.com/rust-lang/rust-clippy/pull/6340)
+
+### Others
+
+* You can now tell Clippy about the MSRV your project supports. Please refer to
+ the specific README section to learn more about MSRV support [here][msrv_readme]
+ [#6201](https://github.com/rust-lang/rust-clippy/pull/6201)
+* Add `--no-deps` option to avoid running on path dependencies in workspaces
+ [#6188](https://github.com/rust-lang/rust-clippy/pull/6188)
+
+## Rust 1.49
+
+Released 2020-12-31
+
+[e636b88...b20d4c1](https://github.com/rust-lang/rust-clippy/compare/e636b88...b20d4c1)
+
+### New Lints
+
+* [`field_reassign_with_default`] [#5911](https://github.com/rust-lang/rust-clippy/pull/5911)
+* [`await_holding_refcell_ref`] [#6029](https://github.com/rust-lang/rust-clippy/pull/6029)
+* [`disallowed_methods`] [#6081](https://github.com/rust-lang/rust-clippy/pull/6081)
+* [`inline_asm_x86_att_syntax`] [#6092](https://github.com/rust-lang/rust-clippy/pull/6092)
+* [`inline_asm_x86_intel_syntax`] [#6092](https://github.com/rust-lang/rust-clippy/pull/6092)
+* [`from_iter_instead_of_collect`] [#6101](https://github.com/rust-lang/rust-clippy/pull/6101)
+* [`mut_mutex_lock`] [#6103](https://github.com/rust-lang/rust-clippy/pull/6103)
+* [`single_element_loop`] [#6109](https://github.com/rust-lang/rust-clippy/pull/6109)
+* [`manual_unwrap_or`] [#6123](https://github.com/rust-lang/rust-clippy/pull/6123)
+* [`large_types_passed_by_value`] [#6135](https://github.com/rust-lang/rust-clippy/pull/6135)
+* [`result_unit_err`] [#6157](https://github.com/rust-lang/rust-clippy/pull/6157)
+* [`ref_option_ref`] [#6165](https://github.com/rust-lang/rust-clippy/pull/6165)
+* [`manual_range_contains`] [#6177](https://github.com/rust-lang/rust-clippy/pull/6177)
+* [`unusual_byte_groupings`] [#6183](https://github.com/rust-lang/rust-clippy/pull/6183)
+* [`comparison_to_empty`] [#6226](https://github.com/rust-lang/rust-clippy/pull/6226)
+* [`map_collect_result_unit`] [#6227](https://github.com/rust-lang/rust-clippy/pull/6227)
+* [`manual_ok_or`] [#6233](https://github.com/rust-lang/rust-clippy/pull/6233)
+
+### Moves and Deprecations
+
+* Rename `single_char_push_str` to [`single_char_add_str`]
+ [#6037](https://github.com/rust-lang/rust-clippy/pull/6037)
+* Rename `zero_width_space` to [`invisible_characters`]
+ [#6105](https://github.com/rust-lang/rust-clippy/pull/6105)
+* Deprecate `drop_bounds` (uplifted)
+ [#6111](https://github.com/rust-lang/rust-clippy/pull/6111)
+* Move [`string_lit_as_bytes`] to `nursery`
+ [#6117](https://github.com/rust-lang/rust-clippy/pull/6117)
+* Move [`rc_buffer`] to `restriction`
+ [#6128](https://github.com/rust-lang/rust-clippy/pull/6128)
+
+### Enhancements
+
+* [`manual_memcpy`]: Also lint when there are loop counters (and produce a
+ reliable suggestion)
+ [#5727](https://github.com/rust-lang/rust-clippy/pull/5727)
+* [`single_char_add_str`]: Also lint on `String::insert_str`
+ [#6037](https://github.com/rust-lang/rust-clippy/pull/6037)
+* [`invisible_characters`]: Also lint the characters `\u{AD}` and `\u{2060}`
+ [#6105](https://github.com/rust-lang/rust-clippy/pull/6105)
+* [`eq_op`]: Also lint on the `assert_*!` macro family
+ [#6167](https://github.com/rust-lang/rust-clippy/pull/6167)
+* [`items_after_statements`]: Also lint in local macro expansions
+ [#6176](https://github.com/rust-lang/rust-clippy/pull/6176)
+* [`unnecessary_cast`]: Also lint casts on integer and float literals
+ [#6187](https://github.com/rust-lang/rust-clippy/pull/6187)
+* [`manual_unwrap_or`]: Also lint `Result::unwrap_or`
+ [#6190](https://github.com/rust-lang/rust-clippy/pull/6190)
+* [`match_like_matches_macro`]: Also lint when `match` has more than two arms
+ [#6216](https://github.com/rust-lang/rust-clippy/pull/6216)
+* [`integer_arithmetic`]: Better handle `/` an `%` operators
+ [#6229](https://github.com/rust-lang/rust-clippy/pull/6229)
+
+### False Positive Fixes
+
+* [`needless_lifetimes`]: Bail out if the function has a `where` clause with the
+ lifetime [#5978](https://github.com/rust-lang/rust-clippy/pull/5978)
+* [`explicit_counter_loop`]: No longer lints, when loop counter is used after it
+ is incremented [#6076](https://github.com/rust-lang/rust-clippy/pull/6076)
+* [`or_fun_call`]: Revert changes addressing the handling of `const fn`
+ [#6077](https://github.com/rust-lang/rust-clippy/pull/6077)
+* [`needless_range_loop`]: No longer lints, when the iterable is used in the
+ range [#6102](https://github.com/rust-lang/rust-clippy/pull/6102)
+* [`inconsistent_digit_grouping`]: Fix bug when using floating point exponent
+ [#6104](https://github.com/rust-lang/rust-clippy/pull/6104)
+* [`mistyped_literal_suffixes`]: No longer lints on the fractional part of a
+ float (e.g. `713.32_64`)
+ [#6114](https://github.com/rust-lang/rust-clippy/pull/6114)
+* [`invalid_regex`]: No longer lint on unicode characters within `bytes::Regex`
+ [#6132](https://github.com/rust-lang/rust-clippy/pull/6132)
+* [`boxed_local`]: No longer lints on `extern fn` arguments
+ [#6133](https://github.com/rust-lang/rust-clippy/pull/6133)
+* [`needless_lifetimes`]: Fix regression, where lifetime is used in `where`
+ clause [#6198](https://github.com/rust-lang/rust-clippy/pull/6198)
+
+### Suggestion Fixes/Improvements
+
+* [`unnecessary_sort_by`]: Avoid dereferencing the suggested closure parameter
+ [#6078](https://github.com/rust-lang/rust-clippy/pull/6078)
+* [`needless_arbitrary_self_type`]: Correctly handle expanded code
+ [#6093](https://github.com/rust-lang/rust-clippy/pull/6093)
+* [`useless_format`]: Preserve raw strings in suggestion
+ [#6151](https://github.com/rust-lang/rust-clippy/pull/6151)
+* [`empty_loop`]: Suggest alternatives
+ [#6162](https://github.com/rust-lang/rust-clippy/pull/6162)
+* [`borrowed_box`]: Correctly add parentheses in suggestion
+ [#6200](https://github.com/rust-lang/rust-clippy/pull/6200)
+* [`unused_unit`]: Improve suggestion formatting
+ [#6247](https://github.com/rust-lang/rust-clippy/pull/6247)
+
+### Documentation Improvements
+
+* Some doc improvements:
+ * [`rc_buffer`] [#6090](https://github.com/rust-lang/rust-clippy/pull/6090)
+ * [`empty_loop`] [#6162](https://github.com/rust-lang/rust-clippy/pull/6162)
+* [`doc_markdown`]: Document problematic link text style
+ [#6107](https://github.com/rust-lang/rust-clippy/pull/6107)
+
+## Rust 1.48
+
+Released 2020-11-19
+
+[09bd400...e636b88](https://github.com/rust-lang/rust-clippy/compare/09bd400...e636b88)
+
+### New lints
+
+* [`self_assignment`] [#5894](https://github.com/rust-lang/rust-clippy/pull/5894)
+* [`unnecessary_lazy_evaluations`] [#5720](https://github.com/rust-lang/rust-clippy/pull/5720)
+* [`manual_strip`] [#6038](https://github.com/rust-lang/rust-clippy/pull/6038)
+* [`map_err_ignore`] [#5998](https://github.com/rust-lang/rust-clippy/pull/5998)
+* [`rc_buffer`] [#6044](https://github.com/rust-lang/rust-clippy/pull/6044)
+* `to_string_in_display` [#5831](https://github.com/rust-lang/rust-clippy/pull/5831)
+* `single_char_push_str` [#5881](https://github.com/rust-lang/rust-clippy/pull/5881)
+
+### Moves and Deprecations
+
+* Downgrade [`verbose_bit_mask`] to pedantic
+ [#6036](https://github.com/rust-lang/rust-clippy/pull/6036)
+
+### Enhancements
+
+* Extend [`precedence`] to handle chains of methods combined with unary negation
+ [#5928](https://github.com/rust-lang/rust-clippy/pull/5928)
+* [`useless_vec`]: add a configuration value for the maximum allowed size on the stack
+ [#5907](https://github.com/rust-lang/rust-clippy/pull/5907)
+* [`suspicious_arithmetic_impl`]: extend to implementations of `BitAnd`, `BitOr`, `BitXor`, `Rem`, `Shl`, and `Shr`
+ [#5884](https://github.com/rust-lang/rust-clippy/pull/5884)
+* `invalid_atomic_ordering`: detect misuse of `compare_exchange`, `compare_exchange_weak`, and `fetch_update`
+ [#6025](https://github.com/rust-lang/rust-clippy/pull/6025)
+* Avoid [`redundant_pattern_matching`] triggering in macros
+ [#6069](https://github.com/rust-lang/rust-clippy/pull/6069)
+* [`option_if_let_else`]: distinguish pure from impure `else` expressions
+ [#5937](https://github.com/rust-lang/rust-clippy/pull/5937)
+* [`needless_doctest_main`]: parse doctests instead of using textual search
+ [#5912](https://github.com/rust-lang/rust-clippy/pull/5912)
+* [`wildcard_imports`]: allow `prelude` to appear in any segment of an import
+ [#5929](https://github.com/rust-lang/rust-clippy/pull/5929)
+* Re-enable [`len_zero`] for ranges now that `range_is_empty` is stable
+ [#5961](https://github.com/rust-lang/rust-clippy/pull/5961)
+* [`option_as_ref_deref`]: catch fully-qualified calls to `Deref::deref` and `DerefMut::deref_mut`
+ [#5933](https://github.com/rust-lang/rust-clippy/pull/5933)
+
+### False Positive Fixes
+
+* [`useless_attribute`]: permit allowing [`wildcard_imports`] and [`enum_glob_use`]
+ [#5994](https://github.com/rust-lang/rust-clippy/pull/5994)
+* [`transmute_ptr_to_ptr`]: avoid suggesting dereferencing raw pointers in const contexts
+ [#5999](https://github.com/rust-lang/rust-clippy/pull/5999)
+* [`redundant_closure_call`]: take into account usages of the closure in nested functions and closures
+ [#5920](https://github.com/rust-lang/rust-clippy/pull/5920)
+* Fix false positive in [`borrow_interior_mutable_const`] when referencing a field behind a pointer
+ [#5949](https://github.com/rust-lang/rust-clippy/pull/5949)
+* [`doc_markdown`]: allow using "GraphQL" without backticks
+ [#5996](https://github.com/rust-lang/rust-clippy/pull/5996)
+* `to_string_in_display`: avoid linting when calling `to_string()` on anything that is not `self`
+ [#5971](https://github.com/rust-lang/rust-clippy/pull/5971)
+* [`indexing_slicing`] and [`out_of_bounds_indexing`] treat references to arrays as arrays
+ [#6034](https://github.com/rust-lang/rust-clippy/pull/6034)
+* [`should_implement_trait`]: ignore methods with lifetime parameters
+ [#5725](https://github.com/rust-lang/rust-clippy/pull/5725)
+* [`needless_return`]: avoid linting if a temporary borrows a local variable
+ [#5903](https://github.com/rust-lang/rust-clippy/pull/5903)
+* Restrict [`unnecessary_sort_by`] to non-reference, Copy types
+ [#6006](https://github.com/rust-lang/rust-clippy/pull/6006)
+* Avoid suggesting `from_bits`/`to_bits` in const contexts in [`transmute_int_to_float`]
+ [#5919](https://github.com/rust-lang/rust-clippy/pull/5919)
+* [`declare_interior_mutable_const`] and [`borrow_interior_mutable_const`]: improve detection of interior mutable types
+ [#6046](https://github.com/rust-lang/rust-clippy/pull/6046)
+
+### Suggestion Fixes/Improvements
+
+* [`let_and_return`]: add a cast to the suggestion when the return expression has adjustments
+ [#5946](https://github.com/rust-lang/rust-clippy/pull/5946)
+* [`useless_conversion`]: show the type in the error message
+ [#6035](https://github.com/rust-lang/rust-clippy/pull/6035)
+* [`unnecessary_mut_passed`]: discriminate between functions and methods in the error message
+ [#5892](https://github.com/rust-lang/rust-clippy/pull/5892)
+* [`float_cmp`] and [`float_cmp_const`]: change wording to make margin of error less ambiguous
+ [#6043](https://github.com/rust-lang/rust-clippy/pull/6043)
+* [`default_trait_access`]: do not use unnecessary type parameters in the suggestion
+ [#5993](https://github.com/rust-lang/rust-clippy/pull/5993)
+* [`collapsible_if`]: don't use expanded code in the suggestion
+ [#5992](https://github.com/rust-lang/rust-clippy/pull/5992)
+* Do not suggest empty format strings in [`print_with_newline`] and [`write_with_newline`]
+ [#6042](https://github.com/rust-lang/rust-clippy/pull/6042)
+* [`unit_arg`]: improve the readability of the suggestion
+ [#5931](https://github.com/rust-lang/rust-clippy/pull/5931)
+* [`stable_sort_primitive`]: print the type that is being sorted in the lint message
+ [#5935](https://github.com/rust-lang/rust-clippy/pull/5935)
+* Show line count and max lines in [`too_many_lines`] lint message
+ [#6009](https://github.com/rust-lang/rust-clippy/pull/6009)
+* Keep parentheses in the suggestion of [`useless_conversion`] where applicable
+ [#5900](https://github.com/rust-lang/rust-clippy/pull/5900)
+* [`option_map_unit_fn`] and [`result_map_unit_fn`]: print the unit type `()` explicitly
+ [#6024](https://github.com/rust-lang/rust-clippy/pull/6024)
+* [`redundant_allocation`]: suggest replacing `Rc<Box<T>>` with `Rc<T>`
+ [#5899](https://github.com/rust-lang/rust-clippy/pull/5899)
+* Make lint messages adhere to rustc dev guide conventions
+ [#5893](https://github.com/rust-lang/rust-clippy/pull/5893)
+
+### ICE Fixes
+
+* Fix ICE in [`repeat_once`]
+ [#5948](https://github.com/rust-lang/rust-clippy/pull/5948)
+
+### Documentation Improvements
+
+* [`mutable_key_type`]: explain potential for false positives when the interior mutable type is not accessed in the `Hash` implementation
+ [#6019](https://github.com/rust-lang/rust-clippy/pull/6019)
+* [`unnecessary_mut_passed`]: fix typo
+ [#5913](https://github.com/rust-lang/rust-clippy/pull/5913)
+* Add example of false positive to [`ptr_arg`] docs.
+ [#5885](https://github.com/rust-lang/rust-clippy/pull/5885)
+* [`box_vec`](https://rust-lang.github.io/rust-clippy/master/index.html#box_collection), [`vec_box`] and [`borrowed_box`]: add link to the documentation of `Box`
+ [#6023](https://github.com/rust-lang/rust-clippy/pull/6023)
+
+## Rust 1.47
+
+Released 2020-10-08
+
+[c2c07fa...09bd400](https://github.com/rust-lang/rust-clippy/compare/c2c07fa...09bd400)
+
+### New lints
+
+* [`derive_ord_xor_partial_ord`] [#5848](https://github.com/rust-lang/rust-clippy/pull/5848)
+* [`trait_duplication_in_bounds`] [#5852](https://github.com/rust-lang/rust-clippy/pull/5852)
+* [`map_identity`] [#5694](https://github.com/rust-lang/rust-clippy/pull/5694)
+* [`unit_return_expecting_ord`] [#5737](https://github.com/rust-lang/rust-clippy/pull/5737)
+* [`pattern_type_mismatch`] [#4841](https://github.com/rust-lang/rust-clippy/pull/4841)
+* [`repeat_once`] [#5773](https://github.com/rust-lang/rust-clippy/pull/5773)
+* [`same_item_push`] [#5825](https://github.com/rust-lang/rust-clippy/pull/5825)
+* [`needless_arbitrary_self_type`] [#5869](https://github.com/rust-lang/rust-clippy/pull/5869)
+* [`match_like_matches_macro`] [#5769](https://github.com/rust-lang/rust-clippy/pull/5769)
+* [`stable_sort_primitive`] [#5809](https://github.com/rust-lang/rust-clippy/pull/5809)
+* [`blanket_clippy_restriction_lints`] [#5750](https://github.com/rust-lang/rust-clippy/pull/5750)
+* [`option_if_let_else`] [#5301](https://github.com/rust-lang/rust-clippy/pull/5301)
+
+### Moves and Deprecations
+
+* Deprecate [`regex_macro`] lint
+ [#5760](https://github.com/rust-lang/rust-clippy/pull/5760)
+* Move [`range_minus_one`] to `pedantic`
+ [#5752](https://github.com/rust-lang/rust-clippy/pull/5752)
+
+### Enhancements
+
+* Improve [`needless_collect`] by catching `collect` calls followed by `iter` or `into_iter` calls
+ [#5837](https://github.com/rust-lang/rust-clippy/pull/5837)
+* [`panic`], [`todo`], [`unimplemented`] and [`unreachable`] now detect calls with formatting
+ [#5811](https://github.com/rust-lang/rust-clippy/pull/5811)
+* Detect more cases of [`suboptimal_flops`] and [`imprecise_flops`]
+ [#5443](https://github.com/rust-lang/rust-clippy/pull/5443)
+* Handle asymmetrical implementations of `PartialEq` in [`cmp_owned`]
+ [#5701](https://github.com/rust-lang/rust-clippy/pull/5701)
+* Make it possible to allow [`unsafe_derive_deserialize`]
+ [#5870](https://github.com/rust-lang/rust-clippy/pull/5870)
+* Catch `ord.min(a).max(b)` where a < b in [`min_max`]
+ [#5871](https://github.com/rust-lang/rust-clippy/pull/5871)
+* Make [`clone_on_copy`] suggestion machine applicable
+ [#5745](https://github.com/rust-lang/rust-clippy/pull/5745)
+* Enable [`len_zero`] on ranges now that `is_empty` is stable on them
+ [#5961](https://github.com/rust-lang/rust-clippy/pull/5961)
+
+### False Positive Fixes
+
+* Avoid triggering [`or_fun_call`] with const fns that take no arguments
+ [#5889](https://github.com/rust-lang/rust-clippy/pull/5889)
+* Fix [`redundant_closure_call`] false positive for closures that have multiple calls
+ [#5800](https://github.com/rust-lang/rust-clippy/pull/5800)
+* Don't lint cases involving `ManuallyDrop` in [`redundant_clone`]
+ [#5824](https://github.com/rust-lang/rust-clippy/pull/5824)
+* Treat a single expression the same as a single statement in the 2nd arm of a match in [`single_match_else`]
+ [#5771](https://github.com/rust-lang/rust-clippy/pull/5771)
+* Don't trigger [`unnested_or_patterns`] if the feature `or_patterns` is not enabled
+ [#5758](https://github.com/rust-lang/rust-clippy/pull/5758)
+* Avoid linting if key borrows in [`unnecessary_sort_by`]
+ [#5756](https://github.com/rust-lang/rust-clippy/pull/5756)
+* Consider `Try` impl for `Poll` when generating suggestions in [`try_err`]
+ [#5857](https://github.com/rust-lang/rust-clippy/pull/5857)
+* Take input lifetimes into account in `manual_async_fn`
+ [#5859](https://github.com/rust-lang/rust-clippy/pull/5859)
+* Fix multiple false positives in [`type_repetition_in_bounds`] and add a configuration option
+ [#5761](https://github.com/rust-lang/rust-clippy/pull/5761)
+* Limit the [`suspicious_arithmetic_impl`] lint to one binary operation
+ [#5820](https://github.com/rust-lang/rust-clippy/pull/5820)
+
+### Suggestion Fixes/Improvements
+
+* Improve readability of [`shadow_unrelated`] suggestion by truncating the RHS snippet
+ [#5788](https://github.com/rust-lang/rust-clippy/pull/5788)
+* Suggest `filter_map` instead of `flat_map` when mapping to `Option` in [`map_flatten`]
+ [#5846](https://github.com/rust-lang/rust-clippy/pull/5846)
+* Ensure suggestion is shown correctly for long method call chains in [`iter_nth_zero`]
+ [#5793](https://github.com/rust-lang/rust-clippy/pull/5793)
+* Drop borrow operator in suggestions of [`redundant_pattern_matching`]
+ [#5815](https://github.com/rust-lang/rust-clippy/pull/5815)
+* Add suggestion for [`iter_skip_next`]
+ [#5843](https://github.com/rust-lang/rust-clippy/pull/5843)
+* Improve [`collapsible_if`] fix suggestion
+ [#5732](https://github.com/rust-lang/rust-clippy/pull/5732)
+
+### ICE Fixes
+
+* Fix ICE caused by [`needless_collect`]
+ [#5877](https://github.com/rust-lang/rust-clippy/pull/5877)
+* Fix ICE caused by [`unnested_or_patterns`]
+ [#5784](https://github.com/rust-lang/rust-clippy/pull/5784)
+
+### Documentation Improvements
+
+* Fix grammar of [`await_holding_lock`] documentation
+ [#5748](https://github.com/rust-lang/rust-clippy/pull/5748)
+
+### Others
+
+* Make lints adhere to the rustc dev guide
+ [#5888](https://github.com/rust-lang/rust-clippy/pull/5888)
+
+## Rust 1.46
+
+Released 2020-08-27
+
+[7ea7cd1...c2c07fa](https://github.com/rust-lang/rust-clippy/compare/7ea7cd1...c2c07fa)
+
+### New lints
+
+* [`unnested_or_patterns`] [#5378](https://github.com/rust-lang/rust-clippy/pull/5378)
+* [`iter_next_slice`] [#5597](https://github.com/rust-lang/rust-clippy/pull/5597)
+* [`unnecessary_sort_by`] [#5623](https://github.com/rust-lang/rust-clippy/pull/5623)
+* [`vec_resize_to_zero`] [#5637](https://github.com/rust-lang/rust-clippy/pull/5637)
+
+### Moves and Deprecations
+
+* Move [`cast_ptr_alignment`] to pedantic [#5667](https://github.com/rust-lang/rust-clippy/pull/5667)
+
+### Enhancements
+
+* Improve [`mem_replace_with_uninit`] lint [#5695](https://github.com/rust-lang/rust-clippy/pull/5695)
+
+### False Positive Fixes
+
+* [`len_zero`]: Avoid linting ranges when the `range_is_empty` feature is not enabled
+ [#5656](https://github.com/rust-lang/rust-clippy/pull/5656)
+* [`let_and_return`]: Don't lint if a temporary borrow is involved
+ [#5680](https://github.com/rust-lang/rust-clippy/pull/5680)
+* [`reversed_empty_ranges`]: Avoid linting `N..N` in for loop arguments in
+ [#5692](https://github.com/rust-lang/rust-clippy/pull/5692)
+* [`if_same_then_else`]: Don't assume multiplication is always commutative
+ [#5702](https://github.com/rust-lang/rust-clippy/pull/5702)
+* [`blacklisted_name`]: Remove `bar` from the default configuration
+ [#5712](https://github.com/rust-lang/rust-clippy/pull/5712)
+* [`redundant_pattern_matching`]: Avoid suggesting non-`const fn` calls in const contexts
+ [#5724](https://github.com/rust-lang/rust-clippy/pull/5724)
+
+### Suggestion Fixes/Improvements
+
+* Fix suggestion of [`unit_arg`] lint, so that it suggest semantic equivalent code
+ [#4455](https://github.com/rust-lang/rust-clippy/pull/4455)
+* Add auto applicable suggestion to [`macro_use_imports`]
+ [#5279](https://github.com/rust-lang/rust-clippy/pull/5279)
+
+### ICE Fixes
+
+* Fix ICE in the `consts` module of Clippy [#5709](https://github.com/rust-lang/rust-clippy/pull/5709)
+
+### Documentation Improvements
+
+* Improve code examples across multiple lints [#5664](https://github.com/rust-lang/rust-clippy/pull/5664)
+
+### Others
+
+* Introduce a `--rustc` flag to `clippy-driver`, which turns `clippy-driver`
+ into `rustc` and passes all the given arguments to `rustc`. This is especially
+ useful for tools that need the `rustc` version Clippy was compiled with,
+ instead of the Clippy version. E.g. `clippy-driver --rustc --version` will
+ print the output of `rustc --version`.
+ [#5178](https://github.com/rust-lang/rust-clippy/pull/5178)
+* New issue templates now make it easier to complain if Clippy is too annoying
+ or not annoying enough! [#5735](https://github.com/rust-lang/rust-clippy/pull/5735)
+
+## Rust 1.45
+
+Released 2020-07-16
+
+[891e1a8...7ea7cd1](https://github.com/rust-lang/rust-clippy/compare/891e1a8...7ea7cd1)
+
+### New lints
+
+* [`match_wildcard_for_single_variants`] [#5582](https://github.com/rust-lang/rust-clippy/pull/5582)
+* [`unsafe_derive_deserialize`] [#5493](https://github.com/rust-lang/rust-clippy/pull/5493)
+* [`if_let_mutex`] [#5332](https://github.com/rust-lang/rust-clippy/pull/5332)
+* [`mismatched_target_os`] [#5506](https://github.com/rust-lang/rust-clippy/pull/5506)
+* [`await_holding_lock`] [#5439](https://github.com/rust-lang/rust-clippy/pull/5439)
+* [`match_on_vec_items`] [#5522](https://github.com/rust-lang/rust-clippy/pull/5522)
+* [`manual_async_fn`] [#5576](https://github.com/rust-lang/rust-clippy/pull/5576)
+* [`reversed_empty_ranges`] [#5583](https://github.com/rust-lang/rust-clippy/pull/5583)
+* [`manual_non_exhaustive`] [#5550](https://github.com/rust-lang/rust-clippy/pull/5550)
+
+### Moves and Deprecations
+
+* Downgrade [`match_bool`] to pedantic [#5408](https://github.com/rust-lang/rust-clippy/pull/5408)
+* Downgrade [`match_wild_err_arm`] to pedantic and update help messages. [#5622](https://github.com/rust-lang/rust-clippy/pull/5622)
+* Downgrade [`useless_let_if_seq`] to nursery. [#5599](https://github.com/rust-lang/rust-clippy/pull/5599)
+* Generalize `option_and_then_some` and rename to [`bind_instead_of_map`]. [#5529](https://github.com/rust-lang/rust-clippy/pull/5529)
+* Rename `identity_conversion` to [`useless_conversion`]. [#5568](https://github.com/rust-lang/rust-clippy/pull/5568)
+* Merge `block_in_if_condition_expr` and `block_in_if_condition_stmt` into [`blocks_in_if_conditions`].
+[#5563](https://github.com/rust-lang/rust-clippy/pull/5563)
+* Merge `option_map_unwrap_or`, `option_map_unwrap_or_else` and `result_map_unwrap_or_else` into [`map_unwrap_or`].
+[#5563](https://github.com/rust-lang/rust-clippy/pull/5563)
+* Merge `option_unwrap_used` and `result_unwrap_used` into [`unwrap_used`].
+[#5563](https://github.com/rust-lang/rust-clippy/pull/5563)
+* Merge `option_expect_used` and `result_expect_used` into [`expect_used`].
+[#5563](https://github.com/rust-lang/rust-clippy/pull/5563)
+* Merge `for_loop_over_option` and `for_loop_over_result` into [`for_loops_over_fallibles`].
+[#5563](https://github.com/rust-lang/rust-clippy/pull/5563)
+
+### Enhancements
+
+* Avoid running cargo lints when not enabled to improve performance. [#5505](https://github.com/rust-lang/rust-clippy/pull/5505)
+* Extend [`useless_conversion`] with `TryFrom` and `TryInto`. [#5631](https://github.com/rust-lang/rust-clippy/pull/5631)
+* Lint also in type parameters and where clauses in [`unused_unit`]. [#5592](https://github.com/rust-lang/rust-clippy/pull/5592)
+* Do not suggest deriving `Default` in [`new_without_default`]. [#5616](https://github.com/rust-lang/rust-clippy/pull/5616)
+
+### False Positive Fixes
+
+* [`while_let_on_iterator`] [#5525](https://github.com/rust-lang/rust-clippy/pull/5525)
+* [`empty_line_after_outer_attr`] [#5609](https://github.com/rust-lang/rust-clippy/pull/5609)
+* [`unnecessary_unwrap`] [#5558](https://github.com/rust-lang/rust-clippy/pull/5558)
+* [`comparison_chain`] [#5596](https://github.com/rust-lang/rust-clippy/pull/5596)
+* Don't trigger [`used_underscore_binding`] in await desugaring. [#5535](https://github.com/rust-lang/rust-clippy/pull/5535)
+* Don't trigger [`borrowed_box`] on mutable references. [#5491](https://github.com/rust-lang/rust-clippy/pull/5491)
+* Allow `1 << 0` in [`identity_op`]. [#5602](https://github.com/rust-lang/rust-clippy/pull/5602)
+* Allow `use super::*;` glob imports in [`wildcard_imports`]. [#5564](https://github.com/rust-lang/rust-clippy/pull/5564)
+* Whitelist more words in [`doc_markdown`]. [#5611](https://github.com/rust-lang/rust-clippy/pull/5611)
+* Skip dev and build deps in [`multiple_crate_versions`]. [#5636](https://github.com/rust-lang/rust-clippy/pull/5636)
+* Honor `allow` attribute on arguments in [`ptr_arg`]. [#5647](https://github.com/rust-lang/rust-clippy/pull/5647)
+* Honor lint level attributes for [`redundant_field_names`], [`just_underscores_and_digits`], [`many_single_char_names`]
+and [`similar_names`]. [#5651](https://github.com/rust-lang/rust-clippy/pull/5651)
+* Ignore calls to `len` in [`or_fun_call`]. [#4429](https://github.com/rust-lang/rust-clippy/pull/4429)
+
+### Suggestion Improvements
+
+* Simplify suggestions in [`manual_memcpy`]. [#5536](https://github.com/rust-lang/rust-clippy/pull/5536)
+* Fix suggestion in [`redundant_pattern_matching`] for macros. [#5511](https://github.com/rust-lang/rust-clippy/pull/5511)
+* Avoid suggesting `copied()` for mutable references in [`map_clone`]. [#5530](https://github.com/rust-lang/rust-clippy/pull/5530)
+* Improve help message for [`clone_double_ref`]. [#5547](https://github.com/rust-lang/rust-clippy/pull/5547)
+
+### ICE Fixes
+
+* Fix ICE caused in unwrap module. [#5590](https://github.com/rust-lang/rust-clippy/pull/5590)
+* Fix ICE on rustc test issue-69020-assoc-const-arith-overflow.rs [#5499](https://github.com/rust-lang/rust-clippy/pull/5499)
+
+### Documentation
+
+* Clarify the documentation of [`unnecessary_mut_passed`]. [#5639](https://github.com/rust-lang/rust-clippy/pull/5639)
+* Extend example for [`unneeded_field_pattern`]. [#5541](https://github.com/rust-lang/rust-clippy/pull/5541)
+
+## Rust 1.44
+
+Released 2020-06-04
+
+[204bb9b...891e1a8](https://github.com/rust-lang/rust-clippy/compare/204bb9b...891e1a8)
+
+### New lints
+
+* [`explicit_deref_methods`] [#5226](https://github.com/rust-lang/rust-clippy/pull/5226)
+* [`implicit_saturating_sub`] [#5427](https://github.com/rust-lang/rust-clippy/pull/5427)
+* [`macro_use_imports`] [#5230](https://github.com/rust-lang/rust-clippy/pull/5230)
+* [`verbose_file_reads`] [#5272](https://github.com/rust-lang/rust-clippy/pull/5272)
+* [`future_not_send`] [#5423](https://github.com/rust-lang/rust-clippy/pull/5423)
+* [`redundant_pub_crate`] [#5319](https://github.com/rust-lang/rust-clippy/pull/5319)
+* [`large_const_arrays`] [#5248](https://github.com/rust-lang/rust-clippy/pull/5248)
+* [`result_map_or_into_option`] [#5415](https://github.com/rust-lang/rust-clippy/pull/5415)
+* [`redundant_allocation`] [#5349](https://github.com/rust-lang/rust-clippy/pull/5349)
+* [`fn_address_comparisons`] [#5294](https://github.com/rust-lang/rust-clippy/pull/5294)
+* [`vtable_address_comparisons`] [#5294](https://github.com/rust-lang/rust-clippy/pull/5294)
+
+
+### Moves and Deprecations
+
+* Deprecate [`replace_consts`] lint [#5380](https://github.com/rust-lang/rust-clippy/pull/5380)
+* Move [`cognitive_complexity`] to nursery [#5428](https://github.com/rust-lang/rust-clippy/pull/5428)
+* Move [`useless_transmute`] to nursery [#5364](https://github.com/rust-lang/rust-clippy/pull/5364)
+* Downgrade [`inefficient_to_string`] to pedantic [#5412](https://github.com/rust-lang/rust-clippy/pull/5412)
+* Downgrade [`option_option`] to pedantic [#5401](https://github.com/rust-lang/rust-clippy/pull/5401)
+* Downgrade [`unreadable_literal`] to pedantic [#5419](https://github.com/rust-lang/rust-clippy/pull/5419)
+* Downgrade [`let_unit_value`] to pedantic [#5409](https://github.com/rust-lang/rust-clippy/pull/5409)
+* Downgrade [`trivially_copy_pass_by_ref`] to pedantic [#5410](https://github.com/rust-lang/rust-clippy/pull/5410)
+* Downgrade [`implicit_hasher`] to pedantic [#5411](https://github.com/rust-lang/rust-clippy/pull/5411)
+
+### Enhancements
+
+* On _nightly_ you can now use `cargo clippy --fix -Z unstable-options` to
+ auto-fix lints that support this [#5363](https://github.com/rust-lang/rust-clippy/pull/5363)
+* Make [`redundant_clone`] also trigger on cases where the cloned value is not
+ consumed. [#5304](https://github.com/rust-lang/rust-clippy/pull/5304)
+* Expand [`integer_arithmetic`] to also disallow bit-shifting [#5430](https://github.com/rust-lang/rust-clippy/pull/5430)
+* [`option_as_ref_deref`] now detects more deref cases [#5425](https://github.com/rust-lang/rust-clippy/pull/5425)
+* [`large_enum_variant`] now report the sizes of the largest and second-largest variants [#5466](https://github.com/rust-lang/rust-clippy/pull/5466)
+* [`bool_comparison`] now also checks for inequality comparisons that can be
+ written more concisely [#5365](https://github.com/rust-lang/rust-clippy/pull/5365)
+* Expand [`clone_on_copy`] to work in method call arguments as well [#5441](https://github.com/rust-lang/rust-clippy/pull/5441)
+* [`redundant_pattern_matching`] now also handles `while let` [#5483](https://github.com/rust-lang/rust-clippy/pull/5483)
+* [`integer_arithmetic`] now also lints references of integers [#5329](https://github.com/rust-lang/rust-clippy/pull/5329)
+* Expand [`float_cmp_const`] to also work on arrays [#5345](https://github.com/rust-lang/rust-clippy/pull/5345)
+* Trigger [`map_flatten`] when map is called on an `Option` [#5473](https://github.com/rust-lang/rust-clippy/pull/5473)
+
+### False Positive Fixes
+
+* [`many_single_char_names`] [#5468](https://github.com/rust-lang/rust-clippy/pull/5468)
+* [`should_implement_trait`] [#5437](https://github.com/rust-lang/rust-clippy/pull/5437)
+* [`unused_self`] [#5387](https://github.com/rust-lang/rust-clippy/pull/5387)
+* [`redundant_clone`] [#5453](https://github.com/rust-lang/rust-clippy/pull/5453)
+* [`precedence`] [#5445](https://github.com/rust-lang/rust-clippy/pull/5445)
+* [`suspicious_op_assign_impl`] [#5424](https://github.com/rust-lang/rust-clippy/pull/5424)
+* [`needless_lifetimes`] [#5293](https://github.com/rust-lang/rust-clippy/pull/5293)
+* [`redundant_pattern`] [#5287](https://github.com/rust-lang/rust-clippy/pull/5287)
+* [`inconsistent_digit_grouping`] [#5451](https://github.com/rust-lang/rust-clippy/pull/5451)
+
+
+### Suggestion Improvements
+
+* Improved [`question_mark`] lint suggestion so that it doesn't add redundant `as_ref()` [#5481](https://github.com/rust-lang/rust-clippy/pull/5481)
+* Improve the suggested placeholder in [`option_map_unit_fn`] [#5292](https://github.com/rust-lang/rust-clippy/pull/5292)
+* Improve suggestion for [`match_single_binding`] when triggered inside a closure [#5350](https://github.com/rust-lang/rust-clippy/pull/5350)
+
+### ICE Fixes
+
+* Handle the unstable `trivial_bounds` feature [#5296](https://github.com/rust-lang/rust-clippy/pull/5296)
+* `shadow_*` lints [#5297](https://github.com/rust-lang/rust-clippy/pull/5297)
+
+### Documentation
+
+* Fix documentation generation for configurable lints [#5353](https://github.com/rust-lang/rust-clippy/pull/5353)
+* Update documentation for [`new_ret_no_self`] [#5448](https://github.com/rust-lang/rust-clippy/pull/5448)
+* The documentation for [`option_option`] now suggest using a tri-state enum [#5403](https://github.com/rust-lang/rust-clippy/pull/5403)
+* Fix bit mask example in [`verbose_bit_mask`] documentation [#5454](https://github.com/rust-lang/rust-clippy/pull/5454)
+* [`wildcard_imports`] documentation now mentions that `use ...::prelude::*` is
+ not linted [#5312](https://github.com/rust-lang/rust-clippy/pull/5312)
+
+## Rust 1.43
+
+Released 2020-04-23
+
+[4ee1206...204bb9b](https://github.com/rust-lang/rust-clippy/compare/4ee1206...204bb9b)
+
+### New lints
+
+* [`imprecise_flops`] [#4897](https://github.com/rust-lang/rust-clippy/pull/4897)
+* [`suboptimal_flops`] [#4897](https://github.com/rust-lang/rust-clippy/pull/4897)
+* [`wildcard_imports`] [#5029](https://github.com/rust-lang/rust-clippy/pull/5029)
+* [`single_component_path_imports`] [#5058](https://github.com/rust-lang/rust-clippy/pull/5058)
+* [`match_single_binding`] [#5061](https://github.com/rust-lang/rust-clippy/pull/5061)
+* [`let_underscore_lock`] [#5101](https://github.com/rust-lang/rust-clippy/pull/5101)
+* [`struct_excessive_bools`] [#5125](https://github.com/rust-lang/rust-clippy/pull/5125)
+* [`fn_params_excessive_bools`] [#5125](https://github.com/rust-lang/rust-clippy/pull/5125)
+* [`option_env_unwrap`] [#5148](https://github.com/rust-lang/rust-clippy/pull/5148)
+* [`lossy_float_literal`] [#5202](https://github.com/rust-lang/rust-clippy/pull/5202)
+* [`rest_pat_in_fully_bound_structs`] [#5258](https://github.com/rust-lang/rust-clippy/pull/5258)
+
+### Moves and Deprecations
+
+* Move [`unneeded_field_pattern`] to pedantic group [#5200](https://github.com/rust-lang/rust-clippy/pull/5200)
+
+### Enhancements
+
+* Make [`missing_errors_doc`] lint also trigger on `async` functions
+ [#5181](https://github.com/rust-lang/rust-clippy/pull/5181)
+* Add more constants to [`approx_constant`] [#5193](https://github.com/rust-lang/rust-clippy/pull/5193)
+* Extend [`question_mark`] lint [#5266](https://github.com/rust-lang/rust-clippy/pull/5266)
+
+### False Positive Fixes
+
+* [`use_debug`] [#5047](https://github.com/rust-lang/rust-clippy/pull/5047)
+* [`unnecessary_unwrap`] [#5132](https://github.com/rust-lang/rust-clippy/pull/5132)
+* [`zero_prefixed_literal`] [#5170](https://github.com/rust-lang/rust-clippy/pull/5170)
+* [`missing_const_for_fn`] [#5216](https://github.com/rust-lang/rust-clippy/pull/5216)
+
+### Suggestion Improvements
+
+* Improve suggestion when blocks of code are suggested [#5134](https://github.com/rust-lang/rust-clippy/pull/5134)
+
+### ICE Fixes
+
+* `misc_early` lints [#5129](https://github.com/rust-lang/rust-clippy/pull/5129)
+* [`missing_errors_doc`] [#5213](https://github.com/rust-lang/rust-clippy/pull/5213)
+* Fix ICE when evaluating `usize`s [#5256](https://github.com/rust-lang/rust-clippy/pull/5256)
+
+### Documentation
+
+* Improve documentation of [`iter_nth_zero`]
+* Add documentation pages for stable releases [#5171](https://github.com/rust-lang/rust-clippy/pull/5171)
+
+### Others
+
+* Clippy now completely runs on GitHub Actions [#5190](https://github.com/rust-lang/rust-clippy/pull/5190)
+
+
+## Rust 1.42
+
+Released 2020-03-12
+
+[69f99e7...4ee1206](https://github.com/rust-lang/rust-clippy/compare/69f99e7...4ee1206)
+
+### New lints
+
+* [`filetype_is_file`] [#4543](https://github.com/rust-lang/rust-clippy/pull/4543)
+* [`let_underscore_must_use`] [#4823](https://github.com/rust-lang/rust-clippy/pull/4823)
+* [`modulo_arithmetic`] [#4867](https://github.com/rust-lang/rust-clippy/pull/4867)
+* [`mem_replace_with_default`] [#4881](https://github.com/rust-lang/rust-clippy/pull/4881)
+* [`mutable_key_type`] [#4885](https://github.com/rust-lang/rust-clippy/pull/4885)
+* [`option_as_ref_deref`] [#4945](https://github.com/rust-lang/rust-clippy/pull/4945)
+* [`wildcard_in_or_patterns`] [#4960](https://github.com/rust-lang/rust-clippy/pull/4960)
+* [`iter_nth_zero`] [#4966](https://github.com/rust-lang/rust-clippy/pull/4966)
+* `invalid_atomic_ordering` [#4999](https://github.com/rust-lang/rust-clippy/pull/4999)
+* [`skip_while_next`] [#5067](https://github.com/rust-lang/rust-clippy/pull/5067)
+
+### Moves and Deprecations
+
+* Move [`transmute_float_to_int`] from nursery to complexity group
+ [#5015](https://github.com/rust-lang/rust-clippy/pull/5015)
+* Move [`range_plus_one`] to pedantic group [#5057](https://github.com/rust-lang/rust-clippy/pull/5057)
+* Move [`debug_assert_with_mut_call`] to nursery group [#5106](https://github.com/rust-lang/rust-clippy/pull/5106)
+* Deprecate `unused_label` [#4930](https://github.com/rust-lang/rust-clippy/pull/4930)
+
+### Enhancements
+
+* Lint vectored IO in [`unused_io_amount`] [#5027](https://github.com/rust-lang/rust-clippy/pull/5027)
+* Make [`vec_box`] configurable by adding a size threshold [#5081](https://github.com/rust-lang/rust-clippy/pull/5081)
+* Also lint constants in [`cmp_nan`] [#4910](https://github.com/rust-lang/rust-clippy/pull/4910)
+* Fix false negative in [`expect_fun_call`] [#4915](https://github.com/rust-lang/rust-clippy/pull/4915)
+* Fix false negative in [`redundant_clone`] [#5017](https://github.com/rust-lang/rust-clippy/pull/5017)
+
+### False Positive Fixes
+
+* [`map_clone`] [#4937](https://github.com/rust-lang/rust-clippy/pull/4937)
+* [`replace_consts`] [#4977](https://github.com/rust-lang/rust-clippy/pull/4977)
+* [`let_and_return`] [#5008](https://github.com/rust-lang/rust-clippy/pull/5008)
+* [`eq_op`] [#5079](https://github.com/rust-lang/rust-clippy/pull/5079)
+* [`possible_missing_comma`] [#5083](https://github.com/rust-lang/rust-clippy/pull/5083)
+* [`debug_assert_with_mut_call`] [#5106](https://github.com/rust-lang/rust-clippy/pull/5106)
+* Don't trigger [`let_underscore_must_use`] in external macros
+ [#5082](https://github.com/rust-lang/rust-clippy/pull/5082)
+* Don't trigger [`empty_loop`] in `no_std` crates [#5086](https://github.com/rust-lang/rust-clippy/pull/5086)
+
+### Suggestion Improvements
+
+* `option_map_unwrap_or` [#4634](https://github.com/rust-lang/rust-clippy/pull/4634)
+* [`wildcard_enum_match_arm`] [#4934](https://github.com/rust-lang/rust-clippy/pull/4934)
+* [`cognitive_complexity`] [#4935](https://github.com/rust-lang/rust-clippy/pull/4935)
+* [`decimal_literal_representation`] [#4956](https://github.com/rust-lang/rust-clippy/pull/4956)
+* `unknown_clippy_lints` [#4963](https://github.com/rust-lang/rust-clippy/pull/4963)
+* [`explicit_into_iter_loop`] [#4978](https://github.com/rust-lang/rust-clippy/pull/4978)
+* [`useless_attribute`] [#5022](https://github.com/rust-lang/rust-clippy/pull/5022)
+* `if_let_some_result` [#5032](https://github.com/rust-lang/rust-clippy/pull/5032)
+
+### ICE fixes
+
+* [`unsound_collection_transmute`] [#4975](https://github.com/rust-lang/rust-clippy/pull/4975)
+
+### Documentation
+
+* Improve documentation of [`empty_enum`], [`replace_consts`], [`redundant_clone`], and [`iterator_step_by_zero`]
+
+
+## Rust 1.41
+
+Released 2020-01-30
+
+[c8e3cfb...69f99e7](https://github.com/rust-lang/rust-clippy/compare/c8e3cfb...69f99e7)
+
+* New Lints:
+ * [`exit`] [#4697](https://github.com/rust-lang/rust-clippy/pull/4697)
+ * [`to_digit_is_some`] [#4801](https://github.com/rust-lang/rust-clippy/pull/4801)
+ * [`tabs_in_doc_comments`] [#4806](https://github.com/rust-lang/rust-clippy/pull/4806)
+ * [`large_stack_arrays`] [#4807](https://github.com/rust-lang/rust-clippy/pull/4807)
+ * [`same_functions_in_if_condition`] [#4814](https://github.com/rust-lang/rust-clippy/pull/4814)
+ * [`zst_offset`] [#4816](https://github.com/rust-lang/rust-clippy/pull/4816)
+ * [`as_conversions`] [#4821](https://github.com/rust-lang/rust-clippy/pull/4821)
+ * [`missing_errors_doc`] [#4884](https://github.com/rust-lang/rust-clippy/pull/4884)
+ * [`transmute_float_to_int`] [#4889](https://github.com/rust-lang/rust-clippy/pull/4889)
+* Remove plugin interface, see
+ [Inside Rust Blog](https://blog.rust-lang.org/inside-rust/2019/11/04/Clippy-removes-plugin-interface.html) for
+ details [#4714](https://github.com/rust-lang/rust-clippy/pull/4714)
+* Move [`use_self`] to nursery group [#4863](https://github.com/rust-lang/rust-clippy/pull/4863)
+* Deprecate `into_iter_on_array` [#4788](https://github.com/rust-lang/rust-clippy/pull/4788)
+* Expand [`string_lit_as_bytes`] to also trigger when literal has escapes
+ [#4808](https://github.com/rust-lang/rust-clippy/pull/4808)
+* Fix false positive in `comparison_chain` [#4842](https://github.com/rust-lang/rust-clippy/pull/4842)
+* Fix false positive in `while_immutable_condition` [#4730](https://github.com/rust-lang/rust-clippy/pull/4730)
+* Fix false positive in `explicit_counter_loop` [#4803](https://github.com/rust-lang/rust-clippy/pull/4803)
+* Fix false positive in `must_use_candidate` [#4794](https://github.com/rust-lang/rust-clippy/pull/4794)
+* Fix false positive in `print_with_newline` and `write_with_newline`
+ [#4769](https://github.com/rust-lang/rust-clippy/pull/4769)
+* Fix false positive in `derive_hash_xor_eq` [#4766](https://github.com/rust-lang/rust-clippy/pull/4766)
+* Fix false positive in `missing_inline_in_public_items` [#4870](https://github.com/rust-lang/rust-clippy/pull/4870)
+* Fix false positive in `string_add` [#4880](https://github.com/rust-lang/rust-clippy/pull/4880)
+* Fix false positive in `float_arithmetic` [#4851](https://github.com/rust-lang/rust-clippy/pull/4851)
+* Fix false positive in `cast_sign_loss` [#4883](https://github.com/rust-lang/rust-clippy/pull/4883)
+* Fix false positive in `manual_swap` [#4877](https://github.com/rust-lang/rust-clippy/pull/4877)
+* Fix ICEs occurring while checking some block expressions [#4772](https://github.com/rust-lang/rust-clippy/pull/4772)
+* Fix ICE in `use_self` [#4776](https://github.com/rust-lang/rust-clippy/pull/4776)
+* Fix ICEs related to `const_generics` [#4780](https://github.com/rust-lang/rust-clippy/pull/4780)
+* Display help when running `clippy-driver` without arguments, instead of ICEing
+ [#4810](https://github.com/rust-lang/rust-clippy/pull/4810)
+* Clippy has its own ICE message now [#4588](https://github.com/rust-lang/rust-clippy/pull/4588)
+* Show deprecated lints in the documentation again [#4757](https://github.com/rust-lang/rust-clippy/pull/4757)
+* Improve Documentation by adding positive examples to some lints
+ [#4832](https://github.com/rust-lang/rust-clippy/pull/4832)
+
+## Rust 1.40
+
+Released 2019-12-19
+
+[4e7e71b...c8e3cfb](https://github.com/rust-lang/rust-clippy/compare/4e7e71b...c8e3cfb)
+
+* New Lints:
+ * [`unneeded_wildcard_pattern`] [#4537](https://github.com/rust-lang/rust-clippy/pull/4537)
+ * [`needless_doctest_main`] [#4603](https://github.com/rust-lang/rust-clippy/pull/4603)
+ * [`suspicious_unary_op_formatting`] [#4615](https://github.com/rust-lang/rust-clippy/pull/4615)
+ * [`debug_assert_with_mut_call`] [#4680](https://github.com/rust-lang/rust-clippy/pull/4680)
+ * [`unused_self`] [#4619](https://github.com/rust-lang/rust-clippy/pull/4619)
+ * [`inefficient_to_string`] [#4683](https://github.com/rust-lang/rust-clippy/pull/4683)
+ * [`must_use_unit`] [#4560](https://github.com/rust-lang/rust-clippy/pull/4560)
+ * [`must_use_candidate`] [#4560](https://github.com/rust-lang/rust-clippy/pull/4560)
+ * [`double_must_use`] [#4560](https://github.com/rust-lang/rust-clippy/pull/4560)
+ * [`comparison_chain`] [#4569](https://github.com/rust-lang/rust-clippy/pull/4569)
+ * [`unsound_collection_transmute`] [#4592](https://github.com/rust-lang/rust-clippy/pull/4592)
+ * [`panic`] [#4657](https://github.com/rust-lang/rust-clippy/pull/4657)
+ * [`unreachable`] [#4657](https://github.com/rust-lang/rust-clippy/pull/4657)
+ * [`todo`] [#4657](https://github.com/rust-lang/rust-clippy/pull/4657)
+ * `option_expect_used` [#4657](https://github.com/rust-lang/rust-clippy/pull/4657)
+ * `result_expect_used` [#4657](https://github.com/rust-lang/rust-clippy/pull/4657)
+* Move `redundant_clone` to perf group [#4509](https://github.com/rust-lang/rust-clippy/pull/4509)
+* Move `manual_mul_add` to nursery group [#4736](https://github.com/rust-lang/rust-clippy/pull/4736)
+* Expand `unit_cmp` to also work with `assert_eq!`, `debug_assert_eq!`, `assert_ne!` and `debug_assert_ne!` [#4613](https://github.com/rust-lang/rust-clippy/pull/4613)
+* Expand `integer_arithmetic` to also detect mutating arithmetic like `+=` [#4585](https://github.com/rust-lang/rust-clippy/pull/4585)
+* Fix false positive in `nonminimal_bool` [#4568](https://github.com/rust-lang/rust-clippy/pull/4568)
+* Fix false positive in `missing_safety_doc` [#4611](https://github.com/rust-lang/rust-clippy/pull/4611)
+* Fix false positive in `cast_sign_loss` [#4614](https://github.com/rust-lang/rust-clippy/pull/4614)
+* Fix false positive in `redundant_clone` [#4509](https://github.com/rust-lang/rust-clippy/pull/4509)
+* Fix false positive in `try_err` [#4721](https://github.com/rust-lang/rust-clippy/pull/4721)
+* Fix false positive in `toplevel_ref_arg` [#4570](https://github.com/rust-lang/rust-clippy/pull/4570)
+* Fix false positive in `multiple_inherent_impl` [#4593](https://github.com/rust-lang/rust-clippy/pull/4593)
+* Improve more suggestions and tests in preparation for the unstable `cargo fix --clippy` [#4575](https://github.com/rust-lang/rust-clippy/pull/4575)
+* Improve suggestion for `zero_ptr` [#4599](https://github.com/rust-lang/rust-clippy/pull/4599)
+* Improve suggestion for `explicit_counter_loop` [#4691](https://github.com/rust-lang/rust-clippy/pull/4691)
+* Improve suggestion for `mul_add` [#4602](https://github.com/rust-lang/rust-clippy/pull/4602)
+* Improve suggestion for `assertions_on_constants` [#4635](https://github.com/rust-lang/rust-clippy/pull/4635)
+* Fix ICE in `use_self` [#4671](https://github.com/rust-lang/rust-clippy/pull/4671)
+* Fix ICE when encountering const casts [#4590](https://github.com/rust-lang/rust-clippy/pull/4590)
+
+## Rust 1.39
+
+Released 2019-11-07
+
+[3aea860...4e7e71b](https://github.com/rust-lang/rust-clippy/compare/3aea860...4e7e71b)
+
+* New Lints:
+ * [`uninit_assumed_init`] [#4479](https://github.com/rust-lang/rust-clippy/pull/4479)
+ * [`flat_map_identity`] [#4231](https://github.com/rust-lang/rust-clippy/pull/4231)
+ * [`missing_safety_doc`] [#4535](https://github.com/rust-lang/rust-clippy/pull/4535)
+ * [`mem_replace_with_uninit`] [#4511](https://github.com/rust-lang/rust-clippy/pull/4511)
+ * [`suspicious_map`] [#4394](https://github.com/rust-lang/rust-clippy/pull/4394)
+ * `option_and_then_some` [#4386](https://github.com/rust-lang/rust-clippy/pull/4386)
+ * [`manual_saturating_arithmetic`] [#4498](https://github.com/rust-lang/rust-clippy/pull/4498)
+* Deprecate `unused_collect` lint. This is fully covered by rustc's `#[must_use]` on `collect` [#4348](https://github.com/rust-lang/rust-clippy/pull/4348)
+* Move `type_repetition_in_bounds` to pedantic group [#4403](https://github.com/rust-lang/rust-clippy/pull/4403)
+* Move `cast_lossless` to pedantic group [#4539](https://github.com/rust-lang/rust-clippy/pull/4539)
+* `temporary_cstring_as_ptr` now catches more cases [#4425](https://github.com/rust-lang/rust-clippy/pull/4425)
+* `use_self` now works in constructors, too [#4525](https://github.com/rust-lang/rust-clippy/pull/4525)
+* `cargo_common_metadata` now checks for license files [#4518](https://github.com/rust-lang/rust-clippy/pull/4518)
+* `cognitive_complexity` now includes the measured complexity in the warning message [#4469](https://github.com/rust-lang/rust-clippy/pull/4469)
+* Fix false positives in `block_in_if_*` lints [#4458](https://github.com/rust-lang/rust-clippy/pull/4458)
+* Fix false positive in `cast_lossless` [#4473](https://github.com/rust-lang/rust-clippy/pull/4473)
+* Fix false positive in `clone_on_copy` [#4411](https://github.com/rust-lang/rust-clippy/pull/4411)
+* Fix false positive in `deref_addrof` [#4487](https://github.com/rust-lang/rust-clippy/pull/4487)
+* Fix false positive in `too_many_lines` [#4490](https://github.com/rust-lang/rust-clippy/pull/4490)
+* Fix false positive in `new_ret_no_self` [#4365](https://github.com/rust-lang/rust-clippy/pull/4365)
+* Fix false positive in `manual_swap` [#4478](https://github.com/rust-lang/rust-clippy/pull/4478)
+* Fix false positive in `missing_const_for_fn` [#4450](https://github.com/rust-lang/rust-clippy/pull/4450)
+* Fix false positive in `extra_unused_lifetimes` [#4477](https://github.com/rust-lang/rust-clippy/pull/4477)
+* Fix false positive in `inherent_to_string` [#4460](https://github.com/rust-lang/rust-clippy/pull/4460)
+* Fix false positive in `map_entry` [#4495](https://github.com/rust-lang/rust-clippy/pull/4495)
+* Fix false positive in `unused_unit` [#4445](https://github.com/rust-lang/rust-clippy/pull/4445)
+* Fix false positive in `redundant_pattern` [#4489](https://github.com/rust-lang/rust-clippy/pull/4489)
+* Fix false positive in `wrong_self_convention` [#4369](https://github.com/rust-lang/rust-clippy/pull/4369)
+* Improve various suggestions and tests in preparation for the unstable `cargo fix --clippy` [#4558](https://github.com/rust-lang/rust-clippy/pull/4558)
+* Improve suggestions for `redundant_pattern_matching` [#4352](https://github.com/rust-lang/rust-clippy/pull/4352)
+* Improve suggestions for `explicit_write` [#4544](https://github.com/rust-lang/rust-clippy/pull/4544)
+* Improve suggestion for `or_fun_call` [#4522](https://github.com/rust-lang/rust-clippy/pull/4522)
+* Improve suggestion for `match_as_ref` [#4446](https://github.com/rust-lang/rust-clippy/pull/4446)
+* Improve suggestion for `unnecessary_fold_span` [#4382](https://github.com/rust-lang/rust-clippy/pull/4382)
+* Add suggestions for `unseparated_literal_suffix` [#4401](https://github.com/rust-lang/rust-clippy/pull/4401)
+* Add suggestions for `char_lit_as_u8` [#4418](https://github.com/rust-lang/rust-clippy/pull/4418)
+
+## Rust 1.38
+
+Released 2019-09-26
+
+[e3cb40e...3aea860](https://github.com/rust-lang/rust-clippy/compare/e3cb40e...3aea860)
+
+* New Lints:
+ * [`main_recursion`] [#4203](https://github.com/rust-lang/rust-clippy/pull/4203)
+ * [`inherent_to_string`] [#4259](https://github.com/rust-lang/rust-clippy/pull/4259)
+ * [`inherent_to_string_shadow_display`] [#4259](https://github.com/rust-lang/rust-clippy/pull/4259)
+ * [`type_repetition_in_bounds`] [#3766](https://github.com/rust-lang/rust-clippy/pull/3766)
+ * [`try_err`] [#4222](https://github.com/rust-lang/rust-clippy/pull/4222)
+* Move `{unnnecessary,panicking}_unwrap` out of nursery [#4307](https://github.com/rust-lang/rust-clippy/pull/4307)
+* Extend the `use_self` lint to suggest uses of `Self::Variant` [#4308](https://github.com/rust-lang/rust-clippy/pull/4308)
+* Improve suggestion for needless return [#4262](https://github.com/rust-lang/rust-clippy/pull/4262)
+* Add auto-fixable suggestion for `let_unit` [#4337](https://github.com/rust-lang/rust-clippy/pull/4337)
+* Fix false positive in `pub_enum_variant_names` and `enum_variant_names` [#4345](https://github.com/rust-lang/rust-clippy/pull/4345)
+* Fix false positive in `cast_ptr_alignment` [#4257](https://github.com/rust-lang/rust-clippy/pull/4257)
+* Fix false positive in `string_lit_as_bytes` [#4233](https://github.com/rust-lang/rust-clippy/pull/4233)
+* Fix false positive in `needless_lifetimes` [#4266](https://github.com/rust-lang/rust-clippy/pull/4266)
+* Fix false positive in `float_cmp` [#4275](https://github.com/rust-lang/rust-clippy/pull/4275)
+* Fix false positives in `needless_return` [#4274](https://github.com/rust-lang/rust-clippy/pull/4274)
+* Fix false negative in `match_same_arms` [#4246](https://github.com/rust-lang/rust-clippy/pull/4246)
+* Fix incorrect suggestion for `needless_bool` [#4335](https://github.com/rust-lang/rust-clippy/pull/4335)
+* Improve suggestion for `cast_ptr_alignment` [#4257](https://github.com/rust-lang/rust-clippy/pull/4257)
+* Improve suggestion for `single_char_literal` [#4361](https://github.com/rust-lang/rust-clippy/pull/4361)
+* Improve suggestion for `len_zero` [#4314](https://github.com/rust-lang/rust-clippy/pull/4314)
+* Fix ICE in `implicit_hasher` [#4268](https://github.com/rust-lang/rust-clippy/pull/4268)
+* Fix allow bug in `trivially_copy_pass_by_ref` [#4250](https://github.com/rust-lang/rust-clippy/pull/4250)
+
+## Rust 1.37
+
+Released 2019-08-15
+
+[082cfa7...e3cb40e](https://github.com/rust-lang/rust-clippy/compare/082cfa7...e3cb40e)
+
+* New Lints:
+ * [`checked_conversions`] [#4088](https://github.com/rust-lang/rust-clippy/pull/4088)
+ * [`get_last_with_len`] [#3832](https://github.com/rust-lang/rust-clippy/pull/3832)
+ * [`integer_division`] [#4195](https://github.com/rust-lang/rust-clippy/pull/4195)
+* Renamed Lint: `const_static_lifetime` is now called [`redundant_static_lifetimes`].
+ The lint now covers statics in addition to consts [#4162](https://github.com/rust-lang/rust-clippy/pull/4162)
+* [`match_same_arms`] now warns for all identical arms, instead of only the first one [#4102](https://github.com/rust-lang/rust-clippy/pull/4102)
+* [`needless_return`] now works with void functions [#4220](https://github.com/rust-lang/rust-clippy/pull/4220)
+* Fix false positive in [`redundant_closure`] [#4190](https://github.com/rust-lang/rust-clippy/pull/4190)
+* Fix false positive in [`useless_attribute`] [#4107](https://github.com/rust-lang/rust-clippy/pull/4107)
+* Fix incorrect suggestion for [`float_cmp`] [#4214](https://github.com/rust-lang/rust-clippy/pull/4214)
+* Add suggestions for [`print_with_newline`] and [`write_with_newline`] [#4136](https://github.com/rust-lang/rust-clippy/pull/4136)
+* Improve suggestions for `option_map_unwrap_or_else` and `result_map_unwrap_or_else` [#4164](https://github.com/rust-lang/rust-clippy/pull/4164)
+* Improve suggestions for [`non_ascii_literal`] [#4119](https://github.com/rust-lang/rust-clippy/pull/4119)
+* Improve diagnostics for [`let_and_return`] [#4137](https://github.com/rust-lang/rust-clippy/pull/4137)
+* Improve diagnostics for [`trivially_copy_pass_by_ref`] [#4071](https://github.com/rust-lang/rust-clippy/pull/4071)
+* Add macro check for [`unreadable_literal`] [#4099](https://github.com/rust-lang/rust-clippy/pull/4099)
+
+## Rust 1.36
+
+Released 2019-07-04
+
+[eb9f9b1...082cfa7](https://github.com/rust-lang/rust-clippy/compare/eb9f9b1...082cfa7)
+
+* New lints: [`find_map`], [`filter_map_next`] [#4039](https://github.com/rust-lang/rust-clippy/pull/4039)
+* New lint: [`path_buf_push_overwrite`] [#3954](https://github.com/rust-lang/rust-clippy/pull/3954)
+* Move `path_buf_push_overwrite` to the nursery [#4013](https://github.com/rust-lang/rust-clippy/pull/4013)
+* Split [`redundant_closure`] into [`redundant_closure`] and [`redundant_closure_for_method_calls`] [#4110](https://github.com/rust-lang/rust-clippy/pull/4101)
+* Allow allowing of [`toplevel_ref_arg`] lint [#4007](https://github.com/rust-lang/rust-clippy/pull/4007)
+* Fix false negative in [`or_fun_call`] pertaining to nested constructors [#4084](https://github.com/rust-lang/rust-clippy/pull/4084)
+* Fix false positive in [`or_fun_call`] pertaining to enum variant constructors [#4018](https://github.com/rust-lang/rust-clippy/pull/4018)
+* Fix false positive in [`useless_let_if_seq`] pertaining to interior mutability [#4035](https://github.com/rust-lang/rust-clippy/pull/4035)
+* Fix false positive in [`redundant_closure`] pertaining to non-function types [#4008](https://github.com/rust-lang/rust-clippy/pull/4008)
+* Fix false positive in [`let_and_return`] pertaining to attributes on `let`s [#4024](https://github.com/rust-lang/rust-clippy/pull/4024)
+* Fix false positive in [`module_name_repetitions`] lint pertaining to attributes [#4006](https://github.com/rust-lang/rust-clippy/pull/4006)
+* Fix false positive on [`assertions_on_constants`] pertaining to `debug_assert!` [#3989](https://github.com/rust-lang/rust-clippy/pull/3989)
+* Improve suggestion in [`map_clone`] to suggest `.copied()` where applicable [#3970](https://github.com/rust-lang/rust-clippy/pull/3970) [#4043](https://github.com/rust-lang/rust-clippy/pull/4043)
+* Improve suggestion for [`search_is_some`] [#4049](https://github.com/rust-lang/rust-clippy/pull/4049)
+* Improve suggestion applicability for [`naive_bytecount`] [#3984](https://github.com/rust-lang/rust-clippy/pull/3984)
+* Improve suggestion applicability for [`while_let_loop`] [#3975](https://github.com/rust-lang/rust-clippy/pull/3975)
+* Improve diagnostics for [`too_many_arguments`] [#4053](https://github.com/rust-lang/rust-clippy/pull/4053)
+* Improve diagnostics for [`cast_lossless`] [#4021](https://github.com/rust-lang/rust-clippy/pull/4021)
+* Deal with macro checks in desugarings better [#4082](https://github.com/rust-lang/rust-clippy/pull/4082)
+* Add macro check for [`unnecessary_cast`] [#4026](https://github.com/rust-lang/rust-clippy/pull/4026)
+* Remove [`approx_constant`]'s documentation's "Known problems" section. [#4027](https://github.com/rust-lang/rust-clippy/pull/4027)
+* Fix ICE in [`suspicious_else_formatting`] [#3960](https://github.com/rust-lang/rust-clippy/pull/3960)
+* Fix ICE in [`decimal_literal_representation`] [#3931](https://github.com/rust-lang/rust-clippy/pull/3931)
+
+
+## Rust 1.35
+
+Released 2019-05-20
+
+[1fac380..37f5c1e](https://github.com/rust-lang/rust-clippy/compare/1fac380...37f5c1e)
+
+* New lint: `drop_bounds` to detect `T: Drop` bounds
+* Split [`redundant_closure`] into [`redundant_closure`] and [`redundant_closure_for_method_calls`] [#4110](https://github.com/rust-lang/rust-clippy/pull/4101)
+* Rename `cyclomatic_complexity` to [`cognitive_complexity`], start work on making lint more practical for Rust code
+* Move [`get_unwrap`] to the restriction category
+* Improve suggestions for [`iter_cloned_collect`]
+* Improve suggestions for [`cast_lossless`] to suggest suffixed literals
+* Fix false positives in [`print_with_newline`] and [`write_with_newline`] pertaining to raw strings
+* Fix false positive in [`needless_range_loop`] pertaining to structs without a `.iter()`
+* Fix false positive in [`bool_comparison`] pertaining to non-bool types
+* Fix false positive in [`redundant_closure`] pertaining to differences in borrows
+* Fix false positive in `option_map_unwrap_or` on non-copy types
+* Fix false positives in [`missing_const_for_fn`] pertaining to macros and trait method impls
+* Fix false positive in [`needless_pass_by_value`] pertaining to procedural macros
+* Fix false positive in [`needless_continue`] pertaining to loop labels
+* Fix false positive for [`boxed_local`] pertaining to arguments moved into closures
+* Fix false positive for [`use_self`] in nested functions
+* Fix suggestion for [`expect_fun_call`] (https://github.com/rust-lang/rust-clippy/pull/3846)
+* Fix suggestion for [`explicit_counter_loop`] to deal with parenthesizing range variables
+* Fix suggestion for [`single_char_pattern`] to correctly escape single quotes
+* Avoid triggering [`redundant_closure`] in macros
+* ICE fixes: [#3805](https://github.com/rust-lang/rust-clippy/pull/3805), [#3772](https://github.com/rust-lang/rust-clippy/pull/3772), [#3741](https://github.com/rust-lang/rust-clippy/pull/3741)
+
+## Rust 1.34
+
+Released 2019-04-10
+
+[1b89724...1fac380](https://github.com/rust-lang/rust-clippy/compare/1b89724...1fac380)
+
+* New lint: [`assertions_on_constants`] to detect for example `assert!(true)`
+* New lint: [`dbg_macro`] to detect uses of the `dbg!` macro
+* New lint: [`missing_const_for_fn`] that can suggest functions to be made `const`
+* New lint: [`too_many_lines`] to detect functions with excessive LOC. It can be
+ configured using the `too-many-lines-threshold` configuration.
+* New lint: [`wildcard_enum_match_arm`] to check for wildcard enum matches using `_`
+* Expand `redundant_closure` to also work for methods (not only functions)
+* Fix ICEs in `vec_box`, `needless_pass_by_value` and `implicit_hasher`
+* Fix false positive in `cast_sign_loss`
+* Fix false positive in `integer_arithmetic`
+* Fix false positive in `unit_arg`
+* Fix false positives in `implicit_return`
+* Add suggestion to `explicit_write`
+* Improve suggestions for `question_mark` lint
+* Fix incorrect suggestion for `cast_lossless`
+* Fix incorrect suggestion for `expect_fun_call`
+* Fix incorrect suggestion for `needless_bool`
+* Fix incorrect suggestion for `needless_range_loop`
+* Fix incorrect suggestion for `use_self`
+* Fix incorrect suggestion for `while_let_on_iterator`
+* Clippy is now slightly easier to invoke in non-cargo contexts. See
+ [#3665][pull3665] for more details.
+* We now have [improved documentation][adding_lints] on how to add new lints
+
+## Rust 1.33
+
+Released 2019-02-26
+
+[b2601be...1b89724](https://github.com/rust-lang/rust-clippy/compare/b2601be...1b89724)
+
+* New lints: [`implicit_return`], [`vec_box`], [`cast_ref_to_mut`]
+* The `rust-clippy` repository is now part of the `rust-lang` org.
+* Rename `stutter` to `module_name_repetitions`
+* Merge `new_without_default_derive` into `new_without_default` lint
+* Move `large_digit_groups` from `style` group to `pedantic`
+* Expand `bool_comparison` to check for `<`, `<=`, `>`, `>=`, and `!=`
+ comparisons against booleans
+* Expand `no_effect` to detect writes to constants such as `A_CONST.field = 2`
+* Expand `redundant_clone` to work on struct fields
+* Expand `suspicious_else_formatting` to detect `if .. {..} {..}`
+* Expand `use_self` to work on tuple structs and also in local macros
+* Fix ICE in `result_map_unit_fn` and `option_map_unit_fn`
+* Fix false positives in `implicit_return`
+* Fix false positives in `use_self`
+* Fix false negative in `clone_on_copy`
+* Fix false positive in `doc_markdown`
+* Fix false positive in `empty_loop`
+* Fix false positive in `if_same_then_else`
+* Fix false positive in `infinite_iter`
+* Fix false positive in `question_mark`
+* Fix false positive in `useless_asref`
+* Fix false positive in `wildcard_dependencies`
+* Fix false positive in `write_with_newline`
+* Add suggestion to `explicit_write`
+* Improve suggestions for `question_mark` lint
+* Fix incorrect suggestion for `get_unwrap`
+
+## Rust 1.32
+
+Released 2019-01-17
+
+[2e26fdc2...b2601be](https://github.com/rust-lang/rust-clippy/compare/2e26fdc2...b2601be)
+
+* New lints: [`slow_vector_initialization`], `mem_discriminant_non_enum`,
+ [`redundant_clone`], [`wildcard_dependencies`],
+ [`into_iter_on_ref`], `into_iter_on_array`, [`deprecated_cfg_attr`],
+ [`cargo_common_metadata`]
+* Add support for `u128` and `i128` to integer related lints
+* Add float support to `mistyped_literal_suffixes`
+* Fix false positives in `use_self`
+* Fix false positives in `missing_comma`
+* Fix false positives in `new_ret_no_self`
+* Fix false positives in `possible_missing_comma`
+* Fix false positive in `integer_arithmetic` in constant items
+* Fix false positive in `needless_borrow`
+* Fix false positive in `out_of_bounds_indexing`
+* Fix false positive in `new_without_default_derive`
+* Fix false positive in `string_lit_as_bytes`
+* Fix false negative in `out_of_bounds_indexing`
+* Fix false negative in `use_self`. It will now also check existential types
+* Fix incorrect suggestion for `redundant_closure_call`
+* Fix various suggestions that contained expanded macros
+* Fix `bool_comparison` triggering 3 times on on on the same code
+* Expand `trivially_copy_pass_by_ref` to work on trait methods
+* Improve suggestion for `needless_range_loop`
+* Move `needless_pass_by_value` from `pedantic` group to `style`
+
+## Rust 1.31
+
+Released 2018-12-06
+
+[125907ad..2e26fdc2](https://github.com/rust-lang/rust-clippy/compare/125907ad..2e26fdc2)
+
+* Clippy has been relicensed under a dual MIT / Apache license.
+ See [#3093](https://github.com/rust-lang/rust-clippy/issues/3093) for more
+ information.
+* With Rust 1.31, Clippy is no longer available via crates.io. The recommended
+ installation method is via `rustup component add clippy`.
+* New lints: [`redundant_pattern_matching`], [`unnecessary_filter_map`],
+ [`unused_unit`], [`map_flatten`], [`mem_replace_option_with_none`]
+* Fix ICE in `if_let_redundant_pattern_matching`
+* Fix ICE in `needless_pass_by_value` when encountering a generic function
+ argument with a lifetime parameter
+* Fix ICE in `needless_range_loop`
+* Fix ICE in `single_char_pattern` when encountering a constant value
+* Fix false positive in `assign_op_pattern`
+* Fix false positive in `boxed_local` on trait implementations
+* Fix false positive in `cmp_owned`
+* Fix false positive in `collapsible_if` when conditionals have comments
+* Fix false positive in `double_parens`
+* Fix false positive in `excessive_precision`
+* Fix false positive in `explicit_counter_loop`
+* Fix false positive in `fn_to_numeric_cast_with_truncation`
+* Fix false positive in `map_clone`
+* Fix false positive in `new_ret_no_self`
+* Fix false positive in `new_without_default` when `new` is unsafe
+* Fix false positive in `type_complexity` when using extern types
+* Fix false positive in `useless_format`
+* Fix false positive in `wrong_self_convention`
+* Fix incorrect suggestion for `excessive_precision`
+* Fix incorrect suggestion for `expect_fun_call`
+* Fix incorrect suggestion for `get_unwrap`
+* Fix incorrect suggestion for `useless_format`
+* `fn_to_numeric_cast_with_truncation` lint can be disabled again
+* Improve suggestions for `manual_memcpy`
+* Improve help message for `needless_lifetimes`
+
+## Rust 1.30
+
+Released 2018-10-25
+
+[14207503...125907ad](https://github.com/rust-lang/rust-clippy/compare/14207503...125907ad)
+
+* Deprecate `assign_ops` lint
+* New lints: [`mistyped_literal_suffixes`], [`ptr_offset_with_cast`],
+ [`needless_collect`], [`copy_iterator`]
+* `cargo clippy -V` now includes the Clippy commit hash of the Rust
+ Clippy component
+* Fix ICE in `implicit_hasher`
+* Fix ICE when encountering `println!("{}" a);`
+* Fix ICE when encountering a macro call in match statements
+* Fix false positive in `default_trait_access`
+* Fix false positive in `trivially_copy_pass_by_ref`
+* Fix false positive in `similar_names`
+* Fix false positive in `redundant_field_name`
+* Fix false positive in `expect_fun_call`
+* Fix false negative in `identity_conversion`
+* Fix false negative in `explicit_counter_loop`
+* Fix `range_plus_one` suggestion and false negative
+* `print_with_newline` / `write_with_newline`: don't warn about string with several `\n`s in them
+* Fix `useless_attribute` to also whitelist `unused_extern_crates`
+* Fix incorrect suggestion for `single_char_pattern`
+* Improve suggestion for `identity_conversion` lint
+* Move `explicit_iter_loop` and `explicit_into_iter_loop` from `style` group to `pedantic`
+* Move `range_plus_one` and `range_minus_one` from `nursery` group to `complexity`
+* Move `shadow_unrelated` from `restriction` group to `pedantic`
+* Move `indexing_slicing` from `pedantic` group to `restriction`
+
+## Rust 1.29
+
+Released 2018-09-13
+
+[v0.0.212...14207503](https://github.com/rust-lang/rust-clippy/compare/v0.0.212...14207503)
+
+* :tada: :tada: **Rust 1.29 is the first stable Rust that includes a bundled Clippy** :tada:
+ :tada:
+ You can now run `rustup component add clippy-preview` and then `cargo
+ clippy` to run Clippy. This should put an end to the continuous nightly
+ upgrades for Clippy users.
+* Clippy now follows the Rust versioning scheme instead of its own
+* Fix ICE when encountering a `while let (..) = x.iter()` construct
+* Fix false positives in `use_self`
+* Fix false positive in `trivially_copy_pass_by_ref`
+* Fix false positive in `useless_attribute` lint
+* Fix false positive in `print_literal`
+* Fix `use_self` regressions
+* Improve lint message for `neg_cmp_op_on_partial_ord`
+* Improve suggestion highlight for `single_char_pattern`
+* Improve suggestions for various print/write macro lints
+* Improve website header
+
+## 0.0.212 (2018-07-10)
+* Rustup to *rustc 1.29.0-nightly (e06c87544 2018-07-06)*
+
+## 0.0.211
+* Rustup to *rustc 1.28.0-nightly (e3bf634e0 2018-06-28)*
+
+## 0.0.210
+* Rustup to *rustc 1.28.0-nightly (01cc982e9 2018-06-24)*
+
+## 0.0.209
+* Rustup to *rustc 1.28.0-nightly (523097979 2018-06-18)*
+
+## 0.0.208
+* Rustup to *rustc 1.28.0-nightly (86a8f1a63 2018-06-17)*
+
+## 0.0.207
+* Rustup to *rustc 1.28.0-nightly (2a0062974 2018-06-09)*
+
+## 0.0.206
+* Rustup to *rustc 1.28.0-nightly (5bf68db6e 2018-05-28)*
+
+## 0.0.205
+* Rustup to *rustc 1.28.0-nightly (990d8aa74 2018-05-25)*
+* Rename `unused_lifetimes` to `extra_unused_lifetimes` because of naming conflict with new rustc lint
+
+## 0.0.204
+* Rustup to *rustc 1.28.0-nightly (71e87be38 2018-05-22)*
+
+## 0.0.203
+* Rustup to *rustc 1.28.0-nightly (a3085756e 2018-05-19)*
+* Clippy attributes are now of the form `clippy::cyclomatic_complexity` instead of `clippy(cyclomatic_complexity)`
+
+## 0.0.202
+* Rustup to *rustc 1.28.0-nightly (952f344cd 2018-05-18)*
+
+## 0.0.201
+* Rustup to *rustc 1.27.0-nightly (2f2a11dfc 2018-05-16)*
+
+## 0.0.200
+* Rustup to *rustc 1.27.0-nightly (9fae15374 2018-05-13)*
+
+## 0.0.199
+* Rustup to *rustc 1.27.0-nightly (ff2ac35db 2018-05-12)*
+
+## 0.0.198
+* Rustup to *rustc 1.27.0-nightly (acd3871ba 2018-05-10)*
+
+## 0.0.197
+* Rustup to *rustc 1.27.0-nightly (428ea5f6b 2018-05-06)*
+
+## 0.0.196
+* Rustup to *rustc 1.27.0-nightly (e82261dfb 2018-05-03)*
+
+## 0.0.195
+* Rustup to *rustc 1.27.0-nightly (ac3c2288f 2018-04-18)*
+
+## 0.0.194
+* Rustup to *rustc 1.27.0-nightly (bd40cbbe1 2018-04-14)*
+* New lints: [`cast_ptr_alignment`], [`transmute_ptr_to_ptr`], [`write_literal`], [`write_with_newline`], [`writeln_empty_string`]
+
+## 0.0.193
+* Rustup to *rustc 1.27.0-nightly (eeea94c11 2018-04-06)*
+
+## 0.0.192
+* Rustup to *rustc 1.27.0-nightly (fb44b4c0e 2018-04-04)*
+* New lint: [`print_literal`]
+
+## 0.0.191
+* Rustup to *rustc 1.26.0-nightly (ae544ee1c 2018-03-29)*
+* Lint audit; categorize lints as style, correctness, complexity, pedantic, nursery, restriction.
+
+## 0.0.190
+* Fix a bunch of intermittent cargo bugs
+
+## 0.0.189
+* Rustup to *rustc 1.26.0-nightly (5508b2714 2018-03-18)*
+
+## 0.0.188
+* Rustup to *rustc 1.26.0-nightly (392645394 2018-03-15)*
+* New lint: [`while_immutable_condition`]
+
+## 0.0.187
+* Rustup to *rustc 1.26.0-nightly (322d7f7b9 2018-02-25)*
+* New lints: [`redundant_field_names`], [`suspicious_arithmetic_impl`], [`suspicious_op_assign_impl`]
+
+## 0.0.186
+* Rustup to *rustc 1.25.0-nightly (0c6091fbd 2018-02-04)*
+* Various false positive fixes
+
+## 0.0.185
+* Rustup to *rustc 1.25.0-nightly (56733bc9f 2018-02-01)*
+* New lint: [`question_mark`]
+
+## 0.0.184
+* Rustup to *rustc 1.25.0-nightly (90eb44a58 2018-01-29)*
+* New lints: [`double_comparisons`], [`empty_line_after_outer_attr`]
+
+## 0.0.183
+* Rustup to *rustc 1.25.0-nightly (21882aad7 2018-01-28)*
+* New lint: [`misaligned_transmute`]
+
+## 0.0.182
+* Rustup to *rustc 1.25.0-nightly (a0dcecff9 2018-01-24)*
+* New lint: [`decimal_literal_representation`]
+
+## 0.0.181
+* Rustup to *rustc 1.25.0-nightly (97520ccb1 2018-01-21)*
+* New lints: [`else_if_without_else`], [`option_option`], [`unit_arg`], [`unnecessary_fold`]
+* Removed `unit_expr`
+* Various false positive fixes for [`needless_pass_by_value`]
+
+## 0.0.180
+* Rustup to *rustc 1.25.0-nightly (3f92e8d89 2018-01-14)*
+
+## 0.0.179
+* Rustup to *rustc 1.25.0-nightly (61452e506 2018-01-09)*
+
+## 0.0.178
+* Rustup to *rustc 1.25.0-nightly (ee220daca 2018-01-07)*
+
+## 0.0.177
+* Rustup to *rustc 1.24.0-nightly (250b49205 2017-12-21)*
+* New lint: [`match_as_ref`]
+
+## 0.0.176
+* Rustup to *rustc 1.24.0-nightly (0077d128d 2017-12-14)*
+
+## 0.0.175
+* Rustup to *rustc 1.24.0-nightly (bb42071f6 2017-12-01)*
+
+## 0.0.174
+* Rustup to *rustc 1.23.0-nightly (63739ab7b 2017-11-21)*
+
+## 0.0.173
+* Rustup to *rustc 1.23.0-nightly (33374fa9d 2017-11-20)*
+
+## 0.0.172
+* Rustup to *rustc 1.23.0-nightly (d0f8e2913 2017-11-16)*
+
+## 0.0.171
+* Rustup to *rustc 1.23.0-nightly (ff0f5de3b 2017-11-14)*
+
+## 0.0.170
+* Rustup to *rustc 1.23.0-nightly (d6b06c63a 2017-11-09)*
+
+## 0.0.169
+* Rustup to *rustc 1.23.0-nightly (3b82e4c74 2017-11-05)*
+* New lints: [`just_underscores_and_digits`], `result_map_unwrap_or_else`, [`transmute_bytes_to_str`]
+
+## 0.0.168
+* Rustup to *rustc 1.23.0-nightly (f0fe716db 2017-10-30)*
+
+## 0.0.167
+* Rustup to *rustc 1.23.0-nightly (90ef3372e 2017-10-29)*
+* New lints: `const_static_lifetime`, [`erasing_op`], [`fallible_impl_from`], [`println_empty_string`], [`useless_asref`]
+
+## 0.0.166
+* Rustup to *rustc 1.22.0-nightly (b7960878b 2017-10-18)*
+* New lints: [`explicit_write`], `identity_conversion`, [`implicit_hasher`], `invalid_ref`, [`option_map_or_none`],
+ [`range_minus_one`], [`range_plus_one`], [`transmute_int_to_bool`], [`transmute_int_to_char`],
+ [`transmute_int_to_float`]
+
+## 0.0.165
+* Rust upgrade to rustc 1.22.0-nightly (0e6f4cf51 2017-09-27)
+* New lint: [`mut_range_bound`]
+
+## 0.0.164
+* Update to *rustc 1.22.0-nightly (6c476ce46 2017-09-25)*
+* New lint: [`int_plus_one`]
+
+## 0.0.163
+* Update to *rustc 1.22.0-nightly (14039a42a 2017-09-22)*
+
+## 0.0.162
+* Update to *rustc 1.22.0-nightly (0701b37d9 2017-09-18)*
+* New lint: [`chars_last_cmp`]
+* Improved suggestions for [`needless_borrow`], [`ptr_arg`],
+
+## 0.0.161
+* Update to *rustc 1.22.0-nightly (539f2083d 2017-09-13)*
+
+## 0.0.160
+* Update to *rustc 1.22.0-nightly (dd08c3070 2017-09-12)*
+
+## 0.0.159
+* Update to *rustc 1.22.0-nightly (eba374fb2 2017-09-11)*
+* New lint: [`clone_on_ref_ptr`]
+
+## 0.0.158
+* New lint: [`manual_memcpy`]
+* [`cast_lossless`] no longer has redundant parentheses in its suggestions
+* Update to *rustc 1.22.0-nightly (dead08cb3 2017-09-08)*
+
+## 0.0.157 - 2017-09-04
+* Update to *rustc 1.22.0-nightly (981ce7d8d 2017-09-03)*
+* New lint: `unit_expr`
+
+## 0.0.156 - 2017-09-03
+* Update to *rustc 1.22.0-nightly (744dd6c1d 2017-09-02)*
+
+## 0.0.155
+* Update to *rustc 1.21.0-nightly (c11f689d2 2017-08-29)*
+* New lint: [`infinite_iter`], [`maybe_infinite_iter`], [`cast_lossless`]
+
+## 0.0.154
+* Update to *rustc 1.21.0-nightly (2c0558f63 2017-08-24)*
+* Fix [`use_self`] triggering inside derives
+* Add support for linting an entire workspace with `cargo clippy --all`
+* New lint: [`naive_bytecount`]
+
+## 0.0.153
+* Update to *rustc 1.21.0-nightly (8c303ed87 2017-08-20)*
+* New lint: [`use_self`]
+
+## 0.0.152
+* Update to *rustc 1.21.0-nightly (df511d554 2017-08-14)*
+
+## 0.0.151
+* Update to *rustc 1.21.0-nightly (13d94d5fa 2017-08-10)*
+
+## 0.0.150
+* Update to *rustc 1.21.0-nightly (215e0b10e 2017-08-08)*
+
+## 0.0.148
+* Update to *rustc 1.21.0-nightly (37c7d0ebb 2017-07-31)*
+* New lints: [`unreadable_literal`], [`inconsistent_digit_grouping`], [`large_digit_groups`]
+
+## 0.0.147
+* Update to *rustc 1.21.0-nightly (aac223f4f 2017-07-30)*
+
+## 0.0.146
+* Update to *rustc 1.21.0-nightly (52a330969 2017-07-27)*
+* Fixes false positives in `inline_always`
+* Fixes false negatives in `panic_params`
+
+## 0.0.145
+* Update to *rustc 1.20.0-nightly (afe145d22 2017-07-23)*
+
+## 0.0.144
+* Update to *rustc 1.20.0-nightly (086eaa78e 2017-07-15)*
+
+## 0.0.143
+* Update to *rustc 1.20.0-nightly (d84693b93 2017-07-09)*
+* Fix `cargo clippy` crashing on `dylib` projects
+* Fix false positives around `nested_while_let` and `never_loop`
+
+## 0.0.142
+* Update to *rustc 1.20.0-nightly (067971139 2017-07-02)*
+
+## 0.0.141
+* Rewrite of the `doc_markdown` lint.
+* Deprecated [`range_step_by_zero`]
+* New lint: [`iterator_step_by_zero`]
+* New lint: [`needless_borrowed_reference`]
+* Update to *rustc 1.20.0-nightly (69c65d296 2017-06-28)*
+
+## 0.0.140 - 2017-06-16
+* Update to *rustc 1.19.0-nightly (258ae6dd9 2017-06-15)*
+
+## 0.0.139 — 2017-06-10
+* Update to *rustc 1.19.0-nightly (4bf5c99af 2017-06-10)*
+* Fix bugs with for loop desugaring
+* Check for [`AsRef`]/[`AsMut`] arguments in [`wrong_self_convention`]
+
+## 0.0.138 — 2017-06-05
+* Update to *rustc 1.19.0-nightly (0418fa9d3 2017-06-04)*
+
+## 0.0.137 — 2017-06-05
+* Update to *rustc 1.19.0-nightly (6684d176c 2017-06-03)*
+
+## 0.0.136 — 2017—05—26
+* Update to *rustc 1.19.0-nightly (557967766 2017-05-26)*
+
+## 0.0.135 — 2017—05—24
+* Update to *rustc 1.19.0-nightly (5b13bff52 2017-05-23)*
+
+## 0.0.134 — 2017—05—19
+* Update to *rustc 1.19.0-nightly (0ed1ec9f9 2017-05-18)*
+
+## 0.0.133 — 2017—05—14
+* Update to *rustc 1.19.0-nightly (826d8f385 2017-05-13)*
+
+## 0.0.132 — 2017—05—05
+* Fix various bugs and some ices
+
+## 0.0.131 — 2017—05—04
+* Update to *rustc 1.19.0-nightly (2d4ed8e0c 2017-05-03)*
+
+## 0.0.130 — 2017—05—03
+* Update to *rustc 1.19.0-nightly (6a5fc9eec 2017-05-02)*
+
+## 0.0.129 — 2017-05-01
+* Update to *rustc 1.19.0-nightly (06fb4d256 2017-04-30)*
+
+## 0.0.128 — 2017-04-28
+* Update to *rustc 1.18.0-nightly (94e884b63 2017-04-27)*
+
+## 0.0.127 — 2017-04-27
+* Update to *rustc 1.18.0-nightly (036983201 2017-04-26)*
+* New lint: [`needless_continue`]
+
+## 0.0.126 — 2017-04-24
+* Update to *rustc 1.18.0-nightly (2bd4b5c6d 2017-04-23)*
+
+## 0.0.125 — 2017-04-19
+* Update to *rustc 1.18.0-nightly (9f2abadca 2017-04-18)*
+
+## 0.0.124 — 2017-04-16
+* Update to *rustc 1.18.0-nightly (d5cf1cb64 2017-04-15)*
+
+## 0.0.123 — 2017-04-07
+* Fix various false positives
+
+## 0.0.122 — 2017-04-07
+* Rustup to *rustc 1.18.0-nightly (91ae22a01 2017-04-05)*
+* New lint: [`op_ref`]
+
+## 0.0.121 — 2017-03-21
+* Rustup to *rustc 1.17.0-nightly (134c4a0f0 2017-03-20)*
+
+## 0.0.120 — 2017-03-17
+* Rustup to *rustc 1.17.0-nightly (0aeb9c129 2017-03-15)*
+
+## 0.0.119 — 2017-03-13
+* Rustup to *rustc 1.17.0-nightly (824c9ebbd 2017-03-12)*
+
+## 0.0.118 — 2017-03-05
+* Rustup to *rustc 1.17.0-nightly (b1e31766d 2017-03-03)*
+
+## 0.0.117 — 2017-03-01
+* Rustup to *rustc 1.17.0-nightly (be760566c 2017-02-28)*
+
+## 0.0.116 — 2017-02-28
+* Fix `cargo clippy` on 64 bit windows systems
+
+## 0.0.115 — 2017-02-27
+* Rustup to *rustc 1.17.0-nightly (60a0edc6c 2017-02-26)*
+* New lints: [`zero_ptr`], [`never_loop`], [`mut_from_ref`]
+
+## 0.0.114 — 2017-02-08
+* Rustup to *rustc 1.17.0-nightly (c49d10207 2017-02-07)*
+* Tests are now ui tests (testing the exact output of rustc)
+
+## 0.0.113 — 2017-02-04
+* Rustup to *rustc 1.16.0-nightly (eedaa94e3 2017-02-02)*
+* New lint: [`large_enum_variant`]
+* `explicit_into_iter_loop` provides suggestions
+
+## 0.0.112 — 2017-01-27
+* Rustup to *rustc 1.16.0-nightly (df8debf6d 2017-01-25)*
+
+## 0.0.111 — 2017-01-21
+* Rustup to *rustc 1.16.0-nightly (a52da95ce 2017-01-20)*
+
+## 0.0.110 — 2017-01-20
+* Add badges and categories to `Cargo.toml`
+
+## 0.0.109 — 2017-01-19
+* Update to *rustc 1.16.0-nightly (c07a6ae77 2017-01-17)*
+
+## 0.0.108 — 2017-01-12
+* Update to *rustc 1.16.0-nightly (2782e8f8f 2017-01-12)*
+
+## 0.0.107 — 2017-01-11
+* Update regex dependency
+* Fix FP when matching `&&mut` by `&ref`
+* Reintroduce `for (_, x) in &mut hash_map` -> `for x in hash_map.values_mut()`
+* New lints: [`unused_io_amount`], [`forget_ref`], [`short_circuit_statement`]
+
+## 0.0.106 — 2017-01-04
+* Fix FP introduced by rustup in [`wrong_self_convention`]
+
+## 0.0.105 — 2017-01-04
+* Update to *rustc 1.16.0-nightly (468227129 2017-01-03)*
+* New lints: [`deref_addrof`], [`double_parens`], [`pub_enum_variant_names`]
+* Fix suggestion in [`new_without_default`]
+* FP fix in [`absurd_extreme_comparisons`]
+
+## 0.0.104 — 2016-12-15
+* Update to *rustc 1.15.0-nightly (8f02c429a 2016-12-15)*
+
+## 0.0.103 — 2016-11-25
+* Update to *rustc 1.15.0-nightly (d5814b03e 2016-11-23)*
+
+## 0.0.102 — 2016-11-24
+* Update to *rustc 1.15.0-nightly (3bf2be9ce 2016-11-22)*
+
+## 0.0.101 — 2016-11-23
+* Update to *rustc 1.15.0-nightly (7b3eeea22 2016-11-21)*
+* New lint: [`string_extend_chars`]
+
+## 0.0.100 — 2016-11-20
+* Update to *rustc 1.15.0-nightly (ac635aa95 2016-11-18)*
+
+## 0.0.99 — 2016-11-18
+* Update to rustc 1.15.0-nightly (0ed951993 2016-11-14)
+* New lint: [`get_unwrap`]
+
+## 0.0.98 — 2016-11-08
+* Fixes an issue due to a change in how cargo handles `--sysroot`, which broke `cargo clippy`
+
+## 0.0.97 — 2016-11-03
+* For convenience, `cargo clippy` defines a `cargo-clippy` feature. This was
+ previously added for a short time under the name `clippy` but removed for
+ compatibility.
+* `cargo clippy --help` is more helping (and less helpful :smile:)
+* Rustup to *rustc 1.14.0-nightly (5665bdf3e 2016-11-02)*
+* New lints: [`if_let_redundant_pattern_matching`], [`partialeq_ne_impl`]
+
+## 0.0.96 — 2016-10-22
+* Rustup to *rustc 1.14.0-nightly (f09420685 2016-10-20)*
+* New lint: [`iter_skip_next`]
+
+## 0.0.95 — 2016-10-06
+* Rustup to *rustc 1.14.0-nightly (3210fd5c2 2016-10-05)*
+
+## 0.0.94 — 2016-10-04
+* Fixes bustage on Windows due to forbidden directory name
+
+## 0.0.93 — 2016-10-03
+* Rustup to *rustc 1.14.0-nightly (144af3e97 2016-10-02)*
+* `option_map_unwrap_or` and `option_map_unwrap_or_else` are now
+ allowed by default.
+* New lint: [`explicit_into_iter_loop`]
+
+## 0.0.92 — 2016-09-30
+* Rustup to *rustc 1.14.0-nightly (289f3a4ca 2016-09-29)*
+
+## 0.0.91 — 2016-09-28
+* Rustup to *rustc 1.13.0-nightly (d0623cf7b 2016-09-26)*
+
+## 0.0.90 — 2016-09-09
+* Rustup to *rustc 1.13.0-nightly (f1f40f850 2016-09-09)*
+
+## 0.0.89 — 2016-09-06
+* Rustup to *rustc 1.13.0-nightly (cbe4de78e 2016-09-05)*
+
+## 0.0.88 — 2016-09-04
+* Rustup to *rustc 1.13.0-nightly (70598e04f 2016-09-03)*
+* The following lints are not new but were only usable through the `clippy`
+ lint groups: [`filter_next`], `for_loop_over_option`,
+ `for_loop_over_result` and [`match_overlapping_arm`]. You should now be
+ able to `#[allow/deny]` them individually and they are available directly
+ through `cargo clippy`.
+
+## 0.0.87 — 2016-08-31
+* Rustup to *rustc 1.13.0-nightly (eac41469d 2016-08-30)*
+* New lints: [`builtin_type_shadow`]
+* Fix FP in [`zero_prefixed_literal`] and `0b`/`0o`
+
+## 0.0.86 — 2016-08-28
+* Rustup to *rustc 1.13.0-nightly (a23064af5 2016-08-27)*
+* New lints: [`missing_docs_in_private_items`], [`zero_prefixed_literal`]
+
+## 0.0.85 — 2016-08-19
+* Fix ICE with [`useless_attribute`]
+* [`useless_attribute`] ignores `unused_imports` on `use` statements
+
+## 0.0.84 — 2016-08-18
+* Rustup to *rustc 1.13.0-nightly (aef6971ca 2016-08-17)*
+
+## 0.0.83 — 2016-08-17
+* Rustup to *rustc 1.12.0-nightly (1bf5fa326 2016-08-16)*
+* New lints: [`print_with_newline`], [`useless_attribute`]
+
+## 0.0.82 — 2016-08-17
+* Rustup to *rustc 1.12.0-nightly (197be89f3 2016-08-15)*
+* New lint: [`module_inception`]
+
+## 0.0.81 — 2016-08-14
+* Rustup to *rustc 1.12.0-nightly (1deb02ea6 2016-08-12)*
+* New lints: [`eval_order_dependence`], [`mixed_case_hex_literals`], [`unseparated_literal_suffix`]
+* False positive fix in [`too_many_arguments`]
+* Addition of functionality to [`needless_borrow`]
+* Suggestions for [`clone_on_copy`]
+* Bug fix in [`wrong_self_convention`]
+* Doc improvements
+
+## 0.0.80 — 2016-07-31
+* Rustup to *rustc 1.12.0-nightly (1225e122f 2016-07-30)*
+* New lints: [`misrefactored_assign_op`], [`serde_api_misuse`]
+
+## 0.0.79 — 2016-07-10
+* Rustup to *rustc 1.12.0-nightly (f93aaf84c 2016-07-09)*
+* Major suggestions refactoring
+
+## 0.0.78 — 2016-07-02
+* Rustup to *rustc 1.11.0-nightly (01411937f 2016-07-01)*
+* New lints: [`wrong_transmute`], [`double_neg`], [`filter_map`]
+* For compatibility, `cargo clippy` does not defines the `clippy` feature
+ introduced in 0.0.76 anymore
+* [`collapsible_if`] now considers `if let`
+
+## 0.0.77 — 2016-06-21
+* Rustup to *rustc 1.11.0-nightly (5522e678b 2016-06-20)*
+* New lints: `stutter` and [`iter_nth`]
+
+## 0.0.76 — 2016-06-10
+* Rustup to *rustc 1.11.0-nightly (7d2f75a95 2016-06-09)*
+* `cargo clippy` now automatically defines the `clippy` feature
+* New lint: [`not_unsafe_ptr_arg_deref`]
+
+## 0.0.75 — 2016-06-08
+* Rustup to *rustc 1.11.0-nightly (763f9234b 2016-06-06)*
+
+## 0.0.74 — 2016-06-07
+* Fix bug with `cargo-clippy` JSON parsing
+* Add the `CLIPPY_DISABLE_DOCS_LINKS` environment variable to deactivate the
+ “for further information visit *lint-link*” message.
+
+## 0.0.73 — 2016-06-05
+* Fix false positives in [`useless_let_if_seq`]
+
+## 0.0.72 — 2016-06-04
+* Fix false positives in [`useless_let_if_seq`]
+
+## 0.0.71 — 2016-05-31
+* Rustup to *rustc 1.11.0-nightly (a967611d8 2016-05-30)*
+* New lint: [`useless_let_if_seq`]
+
+## 0.0.70 — 2016-05-28
+* Rustup to *rustc 1.10.0-nightly (7bddce693 2016-05-27)*
+* [`invalid_regex`] and [`trivial_regex`] can now warn on `RegexSet::new`,
+ `RegexBuilder::new` and byte regexes
+
+## 0.0.69 — 2016-05-20
+* Rustup to *rustc 1.10.0-nightly (476fe6eef 2016-05-21)*
+* [`used_underscore_binding`] has been made `Allow` temporarily
+
+## 0.0.68 — 2016-05-17
+* Rustup to *rustc 1.10.0-nightly (cd6a40017 2016-05-16)*
+* New lint: [`unnecessary_operation`]
+
+## 0.0.67 — 2016-05-12
+* Rustup to *rustc 1.10.0-nightly (22ac88f1a 2016-05-11)*
+
+## 0.0.66 — 2016-05-11
+* New `cargo clippy` subcommand
+* New lints: [`assign_op_pattern`], [`assign_ops`], [`needless_borrow`]
+
+## 0.0.65 — 2016-05-08
+* Rustup to *rustc 1.10.0-nightly (62e2b2fb7 2016-05-06)*
+* New lints: [`float_arithmetic`], [`integer_arithmetic`]
+
+## 0.0.64 — 2016-04-26
+* Rustup to *rustc 1.10.0-nightly (645dd013a 2016-04-24)*
+* New lints: `temporary_cstring_as_ptr`, [`unsafe_removed_from_name`], and [`mem_forget`]
+
+## 0.0.63 — 2016-04-08
+* Rustup to *rustc 1.9.0-nightly (7979dd608 2016-04-07)*
+
+## 0.0.62 — 2016-04-07
+* Rustup to *rustc 1.9.0-nightly (bf5da36f1 2016-04-06)*
+
+## 0.0.61 — 2016-04-03
+* Rustup to *rustc 1.9.0-nightly (5ab11d72c 2016-04-02)*
+* New lint: [`invalid_upcast_comparisons`]
+
+## 0.0.60 — 2016-04-01
+* Rustup to *rustc 1.9.0-nightly (e1195c24b 2016-03-31)*
+
+## 0.0.59 — 2016-03-31
+* Rustup to *rustc 1.9.0-nightly (30a3849f2 2016-03-30)*
+* New lints: [`logic_bug`], [`nonminimal_bool`]
+* Fixed: [`match_same_arms`] now ignores arms with guards
+* Improved: [`useless_vec`] now warns on `for … in vec![…]`
+
+## 0.0.58 — 2016-03-27
+* Rustup to *rustc 1.9.0-nightly (d5a91e695 2016-03-26)*
+* New lint: [`doc_markdown`]
+
+## 0.0.57 — 2016-03-27
+* Update to *rustc 1.9.0-nightly (a1e29daf1 2016-03-25)*
+* Deprecated lints: [`str_to_string`], [`string_to_string`], [`unstable_as_slice`], [`unstable_as_mut_slice`]
+* New lint: [`crosspointer_transmute`]
+
+## 0.0.56 — 2016-03-23
+* Update to *rustc 1.9.0-nightly (0dcc413e4 2016-03-22)*
+* New lints: [`many_single_char_names`] and [`similar_names`]
+
+## 0.0.55 — 2016-03-21
+* Update to *rustc 1.9.0-nightly (02310fd31 2016-03-19)*
+
+## 0.0.54 — 2016-03-16
+* Update to *rustc 1.9.0-nightly (c66d2380a 2016-03-15)*
+
+## 0.0.53 — 2016-03-15
+* Add a [configuration file]
+
+## ~~0.0.52~~
+
+## 0.0.51 — 2016-03-13
+* Add `str` to types considered by [`len_zero`]
+* New lints: [`indexing_slicing`]
+
+## 0.0.50 — 2016-03-11
+* Update to *rustc 1.9.0-nightly (c9629d61c 2016-03-10)*
+
+## 0.0.49 — 2016-03-09
+* Update to *rustc 1.9.0-nightly (eabfc160f 2016-03-08)*
+* New lints: [`overflow_check_conditional`], `unused_label`, [`new_without_default`]
+
+## 0.0.48 — 2016-03-07
+* Fixed: ICE in [`needless_range_loop`] with globals
+
+## 0.0.47 — 2016-03-07
+* Update to *rustc 1.9.0-nightly (998a6720b 2016-03-07)*
+* New lint: [`redundant_closure_call`]
+
+[`AsMut`]: https://doc.rust-lang.org/std/convert/trait.AsMut.html
+[`AsRef`]: https://doc.rust-lang.org/std/convert/trait.AsRef.html
+[configuration file]: ./rust-clippy#configuration
+[pull3665]: https://github.com/rust-lang/rust-clippy/pull/3665
+[adding_lints]: https://github.com/rust-lang/rust-clippy/blob/master/doc/adding_lints.md
+[`README.md`]: https://github.com/rust-lang/rust-clippy/blob/master/README.md
+
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+[`wildcard_enum_match_arm`]: https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_enum_match_arm
+[`wildcard_imports`]: https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_imports
+[`wildcard_in_or_patterns`]: https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_in_or_patterns
+[`write_literal`]: https://rust-lang.github.io/rust-clippy/master/index.html#write_literal
+[`write_with_newline`]: https://rust-lang.github.io/rust-clippy/master/index.html#write_with_newline
+[`writeln_empty_string`]: https://rust-lang.github.io/rust-clippy/master/index.html#writeln_empty_string
+[`wrong_pub_self_convention`]: https://rust-lang.github.io/rust-clippy/master/index.html#wrong_pub_self_convention
+[`wrong_self_convention`]: https://rust-lang.github.io/rust-clippy/master/index.html#wrong_self_convention
+[`wrong_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#wrong_transmute
+[`zero_divided_by_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#zero_divided_by_zero
+[`zero_prefixed_literal`]: https://rust-lang.github.io/rust-clippy/master/index.html#zero_prefixed_literal
+[`zero_ptr`]: https://rust-lang.github.io/rust-clippy/master/index.html#zero_ptr
+[`zero_sized_map_values`]: https://rust-lang.github.io/rust-clippy/master/index.html#zero_sized_map_values
+[`zero_width_space`]: https://rust-lang.github.io/rust-clippy/master/index.html#zero_width_space
+[`zst_offset`]: https://rust-lang.github.io/rust-clippy/master/index.html#zst_offset
+<!-- end autogenerated links to lint list -->
--- /dev/null
- compiletest_rs = { version = "0.7.1", features = ["tmp"] }
+[package]
+name = "clippy"
+version = "0.1.63"
+description = "A bunch of helpful lints to avoid common pitfalls in Rust"
+repository = "https://github.com/rust-lang/rust-clippy"
+readme = "README.md"
+license = "MIT OR Apache-2.0"
+keywords = ["clippy", "lint", "plugin"]
+categories = ["development-tools", "development-tools::cargo-plugins"]
+build = "build.rs"
+edition = "2021"
+publish = false
+
+[[bin]]
+name = "cargo-clippy"
+test = false
+path = "src/main.rs"
+
+[[bin]]
+name = "clippy-driver"
+path = "src/driver.rs"
+
+[dependencies]
+clippy_lints = { path = "clippy_lints" }
+semver = "1.0"
+rustc_tools_util = { path = "rustc_tools_util" }
+tempfile = { version = "3.2", optional = true }
+termize = "0.1"
+
+[dev-dependencies]
- parking_lot = "0.11.2"
++compiletest_rs = { version = "0.8", features = ["tmp"] }
+tester = "0.9"
+regex = "1.5"
+# This is used by the `collect-metadata` alias.
+filetime = "0.2"
+
+# A noop dependency that changes in the Rust repository, it's a bit of a hack.
+# See the `src/tools/rustc-workspace-hack/README.md` file in `rust-lang/rust`
+# for more information.
+rustc-workspace-hack = "1.0"
+
+# UI test dependencies
++clap = { version = "3.1", features = ["derive"] }
+clippy_utils = { path = "clippy_utils" }
+derive-new = "0.5"
+if_chain = "1.0"
+itertools = "0.10.1"
+quote = "1.0"
+serde = { version = "1.0.125", features = ["derive"] }
+syn = { version = "1.0", features = ["full"] }
+futures = "0.3"
++parking_lot = "0.12"
+tokio = { version = "1", features = ["io-util"] }
+rustc-semver = "1.1"
+
+[build-dependencies]
+rustc_tools_util = { version = "0.2", path = "rustc_tools_util" }
+
+[features]
+deny-warnings = ["clippy_lints/deny-warnings"]
+integration = ["tempfile"]
+internal = ["clippy_lints/internal"]
+
+[package.metadata.rust-analyzer]
+# This package uses #[feature(rustc_private)]
+rustc_private = true
--- /dev/null
- clap = "2.33"
+[package]
+name = "clippy_dev"
+version = "0.0.1"
+edition = "2021"
+
+[dependencies]
+aho-corasick = "0.7"
++clap = "3.1"
+indoc = "1.0"
+itertools = "0.10.1"
+opener = "0.5"
+shell-escape = "0.1"
+tempfile = "3.2"
+walkdir = "2.3"
+
+[features]
+deny-warnings = []
+
+[package.metadata.rust-analyzer]
+# This package uses #[feature(rustc_private)]
+rustc_private = true
--- /dev/null
- use clap::{App, AppSettings, Arg, ArgMatches, SubCommand};
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+// warn on lints, that are included in `rust-lang/rust`s bootstrap
+#![warn(rust_2018_idioms, unused_lifetimes)]
+
- ("bless", Some(matches)) => {
++use clap::{Arg, ArgMatches, Command};
+use clippy_dev::{bless, fmt, lint, new_lint, serve, setup, update_lints};
+use indoc::indoc;
+fn main() {
+ let matches = get_clap_config();
+
+ match matches.subcommand() {
- ("fmt", Some(matches)) => {
++ Some(("bless", matches)) => {
+ bless::bless(matches.is_present("ignore-timestamp"));
+ },
- ("update_lints", Some(matches)) => {
++ Some(("fmt", matches)) => {
+ fmt::run(matches.is_present("check"), matches.is_present("verbose"));
+ },
- ("new_lint", Some(matches)) => {
++ Some(("update_lints", matches)) => {
+ if matches.is_present("print-only") {
+ update_lints::print_lints();
+ } else if matches.is_present("check") {
+ update_lints::update(update_lints::UpdateMode::Check);
+ } else {
+ update_lints::update(update_lints::UpdateMode::Change);
+ }
+ },
- ("setup", Some(sub_command)) => match sub_command.subcommand() {
- ("intellij", Some(matches)) => {
++ Some(("new_lint", matches)) => {
+ match new_lint::create(
+ matches.value_of("pass"),
+ matches.value_of("name"),
+ matches.value_of("category"),
+ matches.is_present("msrv"),
+ ) {
+ Ok(_) => update_lints::update(update_lints::UpdateMode::Change),
+ Err(e) => eprintln!("Unable to create lint: {}", e),
+ }
+ },
- ("git-hook", Some(matches)) => {
++ Some(("setup", sub_command)) => match sub_command.subcommand() {
++ Some(("intellij", matches)) => {
+ if matches.is_present("remove") {
+ setup::intellij::remove_rustc_src();
+ } else {
+ setup::intellij::setup_rustc_src(
+ matches
+ .value_of("rustc-repo-path")
+ .expect("this field is mandatory and therefore always valid"),
+ );
+ }
+ },
- ("vscode-tasks", Some(matches)) => {
++ Some(("git-hook", matches)) => {
+ if matches.is_present("remove") {
+ setup::git_hook::remove_hook();
+ } else {
+ setup::git_hook::install_hook(matches.is_present("force-override"));
+ }
+ },
- ("remove", Some(sub_command)) => match sub_command.subcommand() {
- ("git-hook", Some(_)) => setup::git_hook::remove_hook(),
- ("intellij", Some(_)) => setup::intellij::remove_rustc_src(),
- ("vscode-tasks", Some(_)) => setup::vscode::remove_tasks(),
++ Some(("vscode-tasks", matches)) => {
+ if matches.is_present("remove") {
+ setup::vscode::remove_tasks();
+ } else {
+ setup::vscode::install_tasks(matches.is_present("force-override"));
+ }
+ },
+ _ => {},
+ },
- ("serve", Some(matches)) => {
++ Some(("remove", sub_command)) => match sub_command.subcommand() {
++ Some(("git-hook", _)) => setup::git_hook::remove_hook(),
++ Some(("intellij", _)) => setup::intellij::remove_rustc_src(),
++ Some(("vscode-tasks", _)) => setup::vscode::remove_tasks(),
+ _ => {},
+ },
- ("lint", Some(matches)) => {
++ Some(("serve", matches)) => {
+ let port = matches.value_of("port").unwrap().parse().unwrap();
+ let lint = matches.value_of("lint");
+ serve::run(port, lint);
+ },
- ("rename_lint", Some(matches)) => {
++ Some(("lint", matches)) => {
+ let path = matches.value_of("path").unwrap();
+ let args = matches.values_of("args").into_iter().flatten();
+ lint::run(path, args);
+ },
- fn get_clap_config<'a>() -> ArgMatches<'a> {
- App::new("Clippy developer tooling")
- .setting(AppSettings::ArgRequiredElseHelp)
++ Some(("rename_lint", matches)) => {
+ let old_name = matches.value_of("old_name").unwrap();
+ let new_name = matches.value_of("new_name").unwrap_or(old_name);
+ let uplift = matches.is_present("uplift");
+ update_lints::rename(old_name, new_name, uplift);
+ },
+ _ => {},
+ }
+}
+
- SubCommand::with_name("bless")
- .about("bless the test output changes")
- .arg(
- Arg::with_name("ignore-timestamp")
- .long("ignore-timestamp")
- .help("Include files updated before clippy was built"),
- ),
++fn get_clap_config() -> ArgMatches {
++ Command::new("Clippy developer tooling")
++ .arg_required_else_help(true)
+ .subcommand(
- SubCommand::with_name("fmt")
++ Command::new("bless").about("bless the test output changes").arg(
++ Arg::new("ignore-timestamp")
++ .long("ignore-timestamp")
++ .help("Include files updated before clippy was built"),
++ ),
+ )
+ .subcommand(
- .arg(
- Arg::with_name("check")
- .long("check")
- .help("Use the rustfmt --check option"),
- )
- .arg(
- Arg::with_name("verbose")
- .short("v")
- .long("verbose")
- .help("Echo commands run"),
- ),
++ Command::new("fmt")
+ .about("Run rustfmt on all projects and tests")
- SubCommand::with_name("update_lints")
++ .arg(Arg::new("check").long("check").help("Use the rustfmt --check option"))
++ .arg(Arg::new("verbose").short('v').long("verbose").help("Echo commands run")),
+ )
+ .subcommand(
- .arg(Arg::with_name("print-only").long("print-only").help(
++ Command::new("update_lints")
+ .about("Updates lint registration and information from the source code")
+ .long_about(
+ "Makes sure that:\n \
+ * the lint count in README.md is correct\n \
+ * the changelog contains markdown link references at the bottom\n \
+ * all lint groups include the correct lints\n \
+ * lint modules in `clippy_lints/*` are visible in `src/lib.rs` via `pub mod`\n \
+ * all lints are registered in the lint store",
+ )
- Arg::with_name("check")
++ .arg(Arg::new("print-only").long("print-only").help(
+ "Print a table of lints to STDOUT. \
+ This does not include deprecated and internal lints. \
+ (Does not modify any files)",
+ ))
+ .arg(
- SubCommand::with_name("new_lint")
++ Arg::new("check")
+ .long("check")
+ .help("Checks that `cargo dev update_lints` has been run. Used on CI."),
+ ),
+ )
+ .subcommand(
- Arg::with_name("pass")
- .short("p")
++ Command::new("new_lint")
+ .about("Create new lint and run `cargo dev update_lints`")
+ .arg(
- Arg::with_name("name")
- .short("n")
++ Arg::new("pass")
++ .short('p')
+ .long("pass")
+ .help("Specify whether the lint runs during the early or late pass")
+ .takes_value(true)
+ .possible_values(&["early", "late"])
+ .required(true),
+ )
+ .arg(
- Arg::with_name("category")
- .short("c")
++ Arg::new("name")
++ .short('n')
+ .long("name")
+ .help("Name of the new lint in snake case, ex: fn_too_long")
+ .takes_value(true)
+ .required(true),
+ )
+ .arg(
- .arg(
- Arg::with_name("msrv")
- .long("msrv")
- .help("Add MSRV config code to the lint"),
- ),
++ Arg::new("category")
++ .short('c')
+ .long("category")
+ .help("What category the lint belongs to")
+ .default_value("nursery")
+ .possible_values(&[
+ "style",
+ "correctness",
+ "suspicious",
+ "complexity",
+ "perf",
+ "pedantic",
+ "restriction",
+ "cargo",
+ "nursery",
+ "internal",
+ "internal_warn",
+ ])
+ .takes_value(true),
+ )
- SubCommand::with_name("setup")
++ .arg(Arg::new("msrv").long("msrv").help("Add MSRV config code to the lint")),
+ )
+ .subcommand(
- .setting(AppSettings::ArgRequiredElseHelp)
++ Command::new("setup")
+ .about("Support for setting up your personal development environment")
- SubCommand::with_name("intellij")
++ .arg_required_else_help(true)
+ .subcommand(
- Arg::with_name("remove")
++ Command::new("intellij")
+ .about("Alter dependencies so Intellij Rust can find rustc internals")
+ .arg(
- Arg::with_name("rustc-repo-path")
++ Arg::new("remove")
+ .long("remove")
+ .help("Remove the dependencies added with 'cargo dev setup intellij'")
+ .required(false),
+ )
+ .arg(
- .short("r")
++ Arg::new("rustc-repo-path")
+ .long("repo-path")
- SubCommand::with_name("git-hook")
++ .short('r')
+ .help("The path to a rustc repo that will be used for setting the dependencies")
+ .takes_value(true)
+ .value_name("path")
+ .conflicts_with("remove")
+ .required(true),
+ ),
+ )
+ .subcommand(
- Arg::with_name("remove")
++ Command::new("git-hook")
+ .about("Add a pre-commit git hook that formats your code to make it look pretty")
+ .arg(
- Arg::with_name("force-override")
++ Arg::new("remove")
+ .long("remove")
+ .help("Remove the pre-commit hook added with 'cargo dev setup git-hook'")
+ .required(false),
+ )
+ .arg(
- .short("f")
++ Arg::new("force-override")
+ .long("force-override")
- SubCommand::with_name("vscode-tasks")
++ .short('f')
+ .help("Forces the override of an existing git pre-commit hook")
+ .required(false),
+ ),
+ )
+ .subcommand(
- Arg::with_name("remove")
++ Command::new("vscode-tasks")
+ .about("Add several tasks to vscode for formatting, validation and testing")
+ .arg(
- Arg::with_name("force-override")
++ Arg::new("remove")
+ .long("remove")
+ .help("Remove the tasks added with 'cargo dev setup vscode-tasks'")
+ .required(false),
+ )
+ .arg(
- .short("f")
++ Arg::new("force-override")
+ .long("force-override")
- SubCommand::with_name("remove")
++ .short('f')
+ .help("Forces the override of existing vscode tasks")
+ .required(false),
+ ),
+ ),
+ )
+ .subcommand(
- .setting(AppSettings::ArgRequiredElseHelp)
- .subcommand(SubCommand::with_name("git-hook").about("Remove any existing pre-commit git hook"))
- .subcommand(SubCommand::with_name("vscode-tasks").about("Remove any existing vscode tasks"))
++ Command::new("remove")
+ .about("Support for undoing changes done by the setup command")
- SubCommand::with_name("intellij")
- .about("Removes rustc source paths added via `cargo dev setup intellij`"),
++ .arg_required_else_help(true)
++ .subcommand(Command::new("git-hook").about("Remove any existing pre-commit git hook"))
++ .subcommand(Command::new("vscode-tasks").about("Remove any existing vscode tasks"))
+ .subcommand(
- SubCommand::with_name("serve")
++ Command::new("intellij").about("Removes rustc source paths added via `cargo dev setup intellij`"),
+ ),
+ )
+ .subcommand(
- Arg::with_name("port")
++ Command::new("serve")
+ .about("Launch a local 'ALL the Clippy Lints' website in a browser")
+ .arg(
- .short("p")
++ Arg::new("port")
+ .long("port")
- .arg(Arg::with_name("lint").help("Which lint's page to load initially (optional)")),
++ .short('p')
+ .help("Local port for the http server")
+ .default_value("8000")
+ .validator_os(serve::validate_port),
+ )
- SubCommand::with_name("lint")
++ .arg(Arg::new("lint").help("Which lint's page to load initially (optional)")),
+ )
+ .subcommand(
- Arg::with_name("path")
++ Command::new("lint")
+ .about("Manually run clippy on a file or package")
+ .after_help(indoc! {"
+ EXAMPLES
+ Lint a single file:
+ cargo dev lint tests/ui/attrs.rs
+
+ Lint a package directory:
+ cargo dev lint tests/ui-cargo/wildcard_dependencies/fail
+ cargo dev lint ~/my-project
+
+ Run rustfix:
+ cargo dev lint ~/my-project -- --fix
+
+ Set lint levels:
+ cargo dev lint file.rs -- -W clippy::pedantic
+ cargo dev lint ~/my-project -- -- -W clippy::pedantic
+ "})
+ .arg(
- Arg::with_name("args")
- .multiple(true)
++ Arg::new("path")
+ .required(true)
+ .help("The path to a file or package directory to lint"),
+ )
+ .arg(
- SubCommand::with_name("rename_lint")
++ Arg::new("args")
++ .multiple_occurrences(true)
+ .help("Pass extra arguments to cargo/clippy-driver"),
+ ),
+ )
+ .subcommand(
- Arg::with_name("old_name")
++ Command::new("rename_lint")
+ .about("Renames the given lint")
+ .arg(
- Arg::with_name("new_name")
++ Arg::new("old_name")
+ .index(1)
+ .required(true)
+ .help("The name of the lint to rename"),
+ )
+ .arg(
- .required_unless("uplift")
++ Arg::new("new_name")
+ .index(2)
- Arg::with_name("uplift")
++ .required_unless_present("uplift")
+ .help("The new name of the lint"),
+ )
+ .arg(
++ Arg::new("uplift")
+ .long("uplift")
+ .help("This lint will be uplifted into rustc"),
+ ),
+ )
+ .get_matches()
+}
--- /dev/null
- use std::ffi::{OsStr, OsString};
++use std::ffi::OsStr;
++use std::num::ParseIntError;
+use std::path::Path;
+use std::process::Command;
+use std::thread;
+use std::time::{Duration, SystemTime};
+
+/// # Panics
+///
+/// Panics if the python commands could not be spawned
+pub fn run(port: u16, lint: Option<&str>) -> ! {
+ let mut url = Some(match lint {
+ None => format!("http://localhost:{}", port),
+ Some(lint) => format!("http://localhost:{}/#{}", port, lint),
+ });
+
+ loop {
+ if mtime("util/gh-pages/lints.json") < mtime("clippy_lints/src") {
+ Command::new("cargo")
+ .arg("collect-metadata")
+ .spawn()
+ .unwrap()
+ .wait()
+ .unwrap();
+ }
+ if let Some(url) = url.take() {
+ thread::spawn(move || {
+ Command::new("python3")
+ .arg("-m")
+ .arg("http.server")
+ .arg(port.to_string())
+ .current_dir("util/gh-pages")
+ .spawn()
+ .unwrap();
+ // Give some time for python to start
+ thread::sleep(Duration::from_millis(500));
+ // Launch browser after first export.py has completed and http.server is up
+ let _result = opener::open(url);
+ });
+ }
+ thread::sleep(Duration::from_millis(1000));
+ }
+}
+
+fn mtime(path: impl AsRef<Path>) -> SystemTime {
+ let path = path.as_ref();
+ if path.is_dir() {
+ path.read_dir()
+ .into_iter()
+ .flatten()
+ .flatten()
+ .map(|entry| mtime(&entry.path()))
+ .max()
+ .unwrap_or(SystemTime::UNIX_EPOCH)
+ } else {
+ path.metadata()
+ .and_then(|metadata| metadata.modified())
+ .unwrap_or(SystemTime::UNIX_EPOCH)
+ }
+}
+
+#[allow(clippy::missing_errors_doc)]
- pub fn validate_port(arg: &OsStr) -> Result<(), OsString> {
- match arg.to_string_lossy().parse::<u16>() {
- Ok(_port) => Ok(()),
- Err(err) => Err(OsString::from(err.to_string())),
- }
++pub fn validate_port(arg: &OsStr) -> Result<(), ParseIntError> {
++ arg.to_string_lossy().parse::<u16>().map(|_| ())
+}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint_and_then;
++use clippy_utils::source::{trim_span, walk_span_to_context};
++use clippy_utils::{meets_msrv, msrvs};
++use rustc_ast::ast::{Expr, ExprKind, LitKind, Pat, PatKind, RangeEnd, RangeLimits};
++use rustc_errors::Applicability;
++use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
++use rustc_semver::RustcVersion;
++use rustc_session::{declare_tool_lint, impl_lint_pass};
++use rustc_span::Span;
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for ranges which almost include the entire range of letters from 'a' to 'z', but
++ /// don't because they're a half open range.
++ ///
++ /// ### Why is this bad?
++ /// This (`'a'..'z'`) is almost certainly a typo meant to include all letters.
++ ///
++ /// ### Example
++ /// ```rust
++ /// let _ = 'a'..'z';
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// let _ = 'a'..='z';
++ /// ```
++ #[clippy::version = "1.63.0"]
++ pub ALMOST_COMPLETE_LETTER_RANGE,
++ suspicious,
++ "almost complete letter range"
++}
++impl_lint_pass!(AlmostCompleteLetterRange => [ALMOST_COMPLETE_LETTER_RANGE]);
++
++pub struct AlmostCompleteLetterRange {
++ msrv: Option<RustcVersion>,
++}
++impl AlmostCompleteLetterRange {
++ pub fn new(msrv: Option<RustcVersion>) -> Self {
++ Self { msrv }
++ }
++}
++impl EarlyLintPass for AlmostCompleteLetterRange {
++ fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &Expr) {
++ if let ExprKind::Range(Some(start), Some(end), RangeLimits::HalfOpen) = &e.kind {
++ let ctxt = e.span.ctxt();
++ let sugg = if let Some(start) = walk_span_to_context(start.span, ctxt)
++ && let Some(end) = walk_span_to_context(end.span, ctxt)
++ && meets_msrv(self.msrv, msrvs::RANGE_INCLUSIVE)
++ {
++ Some((trim_span(cx.sess().source_map(), start.between(end)), "..="))
++ } else {
++ None
++ };
++ check_range(cx, e.span, start, end, sugg);
++ }
++ }
++
++ fn check_pat(&mut self, cx: &EarlyContext<'_>, p: &Pat) {
++ if let PatKind::Range(Some(start), Some(end), kind) = &p.kind
++ && matches!(kind.node, RangeEnd::Excluded)
++ {
++ let sugg = if meets_msrv(self.msrv, msrvs::RANGE_INCLUSIVE) {
++ "..="
++ } else {
++ "..."
++ };
++ check_range(cx, p.span, start, end, Some((kind.span, sugg)));
++ }
++ }
++
++ extract_msrv_attr!(EarlyContext);
++}
++
++fn check_range(cx: &EarlyContext<'_>, span: Span, start: &Expr, end: &Expr, sugg: Option<(Span, &str)>) {
++ if let ExprKind::Lit(start_lit) = &start.peel_parens().kind
++ && let ExprKind::Lit(end_lit) = &end.peel_parens().kind
++ && matches!(
++ (&start_lit.kind, &end_lit.kind),
++ (LitKind::Byte(b'a') | LitKind::Char('a'), LitKind::Byte(b'z') | LitKind::Char('z'))
++ | (LitKind::Byte(b'A') | LitKind::Char('A'), LitKind::Byte(b'Z') | LitKind::Char('Z'))
++ )
++ {
++ span_lint_and_then(
++ cx,
++ ALMOST_COMPLETE_LETTER_RANGE,
++ span,
++ "almost complete ascii letter range",
++ |diag| {
++ if let Some((span, sugg)) = sugg {
++ diag.span_suggestion(
++ span,
++ "use an inclusive range",
++ sugg.to_owned(),
++ Applicability::MaybeIncorrect,
++ );
++ }
++ }
++ );
++ }
++}
--- /dev/null
- /// Use predefined constants instead:
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::{meets_msrv, msrvs};
+use rustc_ast::ast::{FloatTy, LitFloatType, LitKind};
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::symbol;
+use std::f64::consts as f64;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for floating point literals that approximate
+ /// constants which are defined in
+ /// [`std::f32::consts`](https://doc.rust-lang.org/stable/std/f32/consts/#constants)
+ /// or
+ /// [`std::f64::consts`](https://doc.rust-lang.org/stable/std/f64/consts/#constants),
+ /// respectively, suggesting to use the predefined constant.
+ ///
+ /// ### Why is this bad?
+ /// Usually, the definition in the standard library is more
+ /// precise than what people come up with. If you find that your definition is
+ /// actually more precise, please [file a Rust
+ /// issue](https://github.com/rust-lang/rust/issues).
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = 3.14;
+ /// let y = 1_f64 / x;
+ /// ```
++ /// Use instead:
+ /// ```rust
+ /// let x = std::f32::consts::PI;
+ /// let y = std::f64::consts::FRAC_1_PI;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub APPROX_CONSTANT,
+ correctness,
+ "the approximate of a known float constant (in `std::fXX::consts`)"
+}
+
+// Tuples are of the form (constant, name, min_digits, msrv)
+const KNOWN_CONSTS: [(f64, &str, usize, Option<RustcVersion>); 19] = [
+ (f64::E, "E", 4, None),
+ (f64::FRAC_1_PI, "FRAC_1_PI", 4, None),
+ (f64::FRAC_1_SQRT_2, "FRAC_1_SQRT_2", 5, None),
+ (f64::FRAC_2_PI, "FRAC_2_PI", 5, None),
+ (f64::FRAC_2_SQRT_PI, "FRAC_2_SQRT_PI", 5, None),
+ (f64::FRAC_PI_2, "FRAC_PI_2", 5, None),
+ (f64::FRAC_PI_3, "FRAC_PI_3", 5, None),
+ (f64::FRAC_PI_4, "FRAC_PI_4", 5, None),
+ (f64::FRAC_PI_6, "FRAC_PI_6", 5, None),
+ (f64::FRAC_PI_8, "FRAC_PI_8", 5, None),
+ (f64::LN_2, "LN_2", 5, None),
+ (f64::LN_10, "LN_10", 5, None),
+ (f64::LOG2_10, "LOG2_10", 5, Some(msrvs::LOG2_10)),
+ (f64::LOG2_E, "LOG2_E", 5, None),
+ (f64::LOG10_2, "LOG10_2", 5, Some(msrvs::LOG10_2)),
+ (f64::LOG10_E, "LOG10_E", 5, None),
+ (f64::PI, "PI", 3, None),
+ (f64::SQRT_2, "SQRT_2", 5, None),
+ (f64::TAU, "TAU", 3, Some(msrvs::TAU)),
+];
+
+pub struct ApproxConstant {
+ msrv: Option<RustcVersion>,
+}
+
+impl ApproxConstant {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self { msrv }
+ }
+
+ fn check_lit(&self, cx: &LateContext<'_>, lit: &LitKind, e: &Expr<'_>) {
+ match *lit {
+ LitKind::Float(s, LitFloatType::Suffixed(fty)) => match fty {
+ FloatTy::F32 => self.check_known_consts(cx, e, s, "f32"),
+ FloatTy::F64 => self.check_known_consts(cx, e, s, "f64"),
+ },
+ LitKind::Float(s, LitFloatType::Unsuffixed) => self.check_known_consts(cx, e, s, "f{32, 64}"),
+ _ => (),
+ }
+ }
+
+ fn check_known_consts(&self, cx: &LateContext<'_>, e: &Expr<'_>, s: symbol::Symbol, module: &str) {
+ let s = s.as_str();
+ if s.parse::<f64>().is_ok() {
+ for &(constant, name, min_digits, msrv) in &KNOWN_CONSTS {
+ if is_approx_const(constant, s, min_digits) && msrv.map_or(true, |msrv| meets_msrv(self.msrv, msrv)) {
+ span_lint_and_help(
+ cx,
+ APPROX_CONSTANT,
+ e.span,
+ &format!("approximate value of `{}::consts::{}` found", module, &name),
+ None,
+ "consider using the constant directly",
+ );
+ return;
+ }
+ }
+ }
+ }
+}
+
+impl_lint_pass!(ApproxConstant => [APPROX_CONSTANT]);
+
+impl<'tcx> LateLintPass<'tcx> for ApproxConstant {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ if let ExprKind::Lit(lit) = &e.kind {
+ self.check_lit(cx, &lit.node, e);
+ }
+ }
+
+ extract_msrv_attr!(LateContext);
+}
+
+/// Returns `false` if the number of significant figures in `value` are
+/// less than `min_digits`; otherwise, returns true if `value` is equal
+/// to `constant`, rounded to the number of digits present in `value`.
+#[must_use]
+fn is_approx_const(constant: f64, value: &str, min_digits: usize) -> bool {
+ if value.len() <= min_digits {
+ false
+ } else if constant.to_string().starts_with(value) {
+ // The value is a truncated constant
+ true
+ } else {
+ let round_const = format!("{:.*}", value.len() - 2, constant);
+ value == round_const
+ }
+}
--- /dev/null
- /// Usually better represents the semantics you expect:
+use clippy_utils::diagnostics::span_lint_and_help;
+use rustc_ast::ast::{Expr, ExprKind};
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `as` conversions.
+ ///
+ /// Note that this lint is specialized in linting *every single* use of `as`
+ /// regardless of whether good alternatives exist or not.
+ /// If you want more precise lints for `as`, please consider using these separate lints:
+ /// `unnecessary_cast`, `cast_lossless/possible_truncation/possible_wrap/precision_loss/sign_loss`,
+ /// `fn_to_numeric_cast(_with_truncation)`, `char_lit_as_u8`, `ref_to_mut` and `ptr_as_ptr`.
+ /// There is a good explanation the reason why this lint should work in this way and how it is useful
+ /// [in this issue](https://github.com/rust-lang/rust-clippy/issues/5122).
+ ///
+ /// ### Why is this bad?
+ /// `as` conversions will perform many kinds of
+ /// conversions, including silently lossy conversions and dangerous coercions.
+ /// There are cases when it makes sense to use `as`, so the lint is
+ /// Allow by default.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// let a: u32;
+ /// ...
+ /// f(a as u16);
+ /// ```
+ ///
- /// ```
- /// or
- /// ```rust,ignore
++ /// Use instead:
+ /// ```rust,ignore
+ /// f(a.try_into()?);
- ///
++ ///
++ /// // or
++ ///
+ /// f(a.try_into().expect("Unexpected u16 overflow in f"));
+ /// ```
+ #[clippy::version = "1.41.0"]
+ pub AS_CONVERSIONS,
+ restriction,
+ "using a potentially dangerous silent `as` conversion"
+}
+
+declare_lint_pass!(AsConversions => [AS_CONVERSIONS]);
+
+impl EarlyLintPass for AsConversions {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+
+ if let ExprKind::Cast(_, _) = expr.kind {
+ span_lint_and_help(
+ cx,
+ AS_CONVERSIONS,
+ expr.span,
+ "using a potentially dangerous silent `as` conversion",
+ None,
+ "consider using a safe wrapper for this conversion",
+ );
+ }
+ }
+}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_then};
++use rustc_errors::Applicability;
++use rustc_hir::{Expr, ExprKind, TyKind};
++use rustc_lint::{LateContext, LateLintPass, LintContext};
++use rustc_middle::lint::in_external_macro;
++use rustc_middle::ty;
++use rustc_session::{declare_lint_pass, declare_tool_lint};
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Check for the usage of `as _` conversion using inferred type.
++ ///
++ /// ### Why is this bad?
++ /// The conversion might include lossy conversion and dangerous cast that might go
++ /// undetected du to the type being inferred.
++ ///
++ /// The lint is allowed by default as using `_` is less wordy than always specifying the type.
++ ///
++ /// ### Example
++ /// ```rust
++ /// fn foo(n: usize) {}
++ /// let n: u16 = 256;
++ /// foo(n as _);
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// fn foo(n: usize) {}
++ /// let n: u16 = 256;
++ /// foo(n as usize);
++ /// ```
++ #[clippy::version = "1.63.0"]
++ pub AS_UNDERSCORE,
++ restriction,
++ "detects `as _` conversion"
++}
++declare_lint_pass!(AsUnderscore => [AS_UNDERSCORE]);
++
++impl<'tcx> LateLintPass<'tcx> for AsUnderscore {
++ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &Expr<'tcx>) {
++ if in_external_macro(cx.sess(), expr.span) {
++ return;
++ }
++
++ if let ExprKind::Cast(_, ty) = expr.kind && let TyKind::Infer = ty.kind {
++
++ let ty_resolved = cx.typeck_results().expr_ty(expr);
++ if let ty::Error(_) = ty_resolved.kind() {
++ span_lint_and_help(
++ cx,
++ AS_UNDERSCORE,
++ expr.span,
++ "using `as _` conversion",
++ None,
++ "consider giving the type explicitly",
++ );
++ } else {
++ span_lint_and_then(
++ cx,
++ AS_UNDERSCORE,
++ expr.span,
++ "using `as _` conversion",
++ |diag| {
++ diag.span_suggestion(
++ ty.span,
++ "consider giving the type explicitly",
++ format!("{}", ty_resolved),
++ Applicability::MachineApplicable,
++ );
++ }
++ );
++ }
++ }
++ }
++}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::source::snippet_opt;
+use clippy_utils::ty::implements_trait;
+use clippy_utils::{binop_traits, sugg};
+use clippy_utils::{eq_expr_value, trait_ref_of_method};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::intravisit::{walk_expr, Visitor};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `a = a op b` or `a = b commutative_op a`
+ /// patterns.
+ ///
+ /// ### Why is this bad?
+ /// These can be written as the shorter `a op= b`.
+ ///
+ /// ### Known problems
+ /// While forbidden by the spec, `OpAssign` traits may have
+ /// implementations that differ from the regular `Op` impl.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let mut a = 5;
+ /// let b = 0;
+ /// // ...
- /// // Good
++ ///
+ /// a = a + b;
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// let mut a = 5;
++ /// let b = 0;
++ /// // ...
+ ///
+ /// a += b;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ASSIGN_OP_PATTERN,
+ style,
+ "assigning the result of an operation on a variable to that same variable"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `a op= a op b` or `a op= b op a` patterns.
+ ///
+ /// ### Why is this bad?
+ /// Most likely these are bugs where one meant to write `a
+ /// op= b`.
+ ///
+ /// ### Known problems
+ /// Clippy cannot know for sure if `a op= a op b` should have
+ /// been `a = a op a op b` or `a = a op b`/`a op= b`. Therefore, it suggests both.
+ /// If `a op= a op b` is really the correct behavior it should be
+ /// written as `a = a op a op b` as it's less confusing.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let mut a = 5;
+ /// let b = 2;
+ /// // ...
+ /// a += a + b;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MISREFACTORED_ASSIGN_OP,
+ suspicious,
+ "having a variable on both sides of an assign op"
+}
+
+declare_lint_pass!(AssignOps => [ASSIGN_OP_PATTERN, MISREFACTORED_ASSIGN_OP]);
+
+impl<'tcx> LateLintPass<'tcx> for AssignOps {
+ #[allow(clippy::too_many_lines)]
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
+ match &expr.kind {
+ hir::ExprKind::AssignOp(op, lhs, rhs) => {
+ if let hir::ExprKind::Binary(binop, l, r) = &rhs.kind {
+ if op.node != binop.node {
+ return;
+ }
+ // lhs op= l op r
+ if eq_expr_value(cx, lhs, l) {
+ lint_misrefactored_assign_op(cx, expr, *op, rhs, lhs, r);
+ }
+ // lhs op= l commutative_op r
+ if is_commutative(op.node) && eq_expr_value(cx, lhs, r) {
+ lint_misrefactored_assign_op(cx, expr, *op, rhs, lhs, l);
+ }
+ }
+ },
+ hir::ExprKind::Assign(assignee, e, _) => {
+ if let hir::ExprKind::Binary(op, l, r) = &e.kind {
+ let lint = |assignee: &hir::Expr<'_>, rhs: &hir::Expr<'_>| {
+ let ty = cx.typeck_results().expr_ty(assignee);
+ let rty = cx.typeck_results().expr_ty(rhs);
+ if_chain! {
+ if let Some((_, lang_item)) = binop_traits(op.node);
+ if let Ok(trait_id) = cx.tcx.lang_items().require(lang_item);
+ let parent_fn = cx.tcx.hir().get_parent_item(e.hir_id);
+ if trait_ref_of_method(cx, parent_fn)
+ .map_or(true, |t| t.path.res.def_id() != trait_id);
+ if implements_trait(cx, ty, trait_id, &[rty.into()]);
+ then {
+ span_lint_and_then(
+ cx,
+ ASSIGN_OP_PATTERN,
+ expr.span,
+ "manual implementation of an assign operation",
+ |diag| {
+ if let (Some(snip_a), Some(snip_r)) =
+ (snippet_opt(cx, assignee.span), snippet_opt(cx, rhs.span))
+ {
+ diag.span_suggestion(
+ expr.span,
+ "replace it with",
+ format!("{} {}= {}", snip_a, op.node.as_str(), snip_r),
+ Applicability::MachineApplicable,
+ );
+ }
+ },
+ );
+ }
+ }
+ };
+
+ let mut visitor = ExprVisitor {
+ assignee,
+ counter: 0,
+ cx,
+ };
+
+ walk_expr(&mut visitor, e);
+
+ if visitor.counter == 1 {
+ // a = a op b
+ if eq_expr_value(cx, assignee, l) {
+ lint(assignee, r);
+ }
+ // a = b commutative_op a
+ // Limited to primitive type as these ops are know to be commutative
+ if eq_expr_value(cx, assignee, r) && cx.typeck_results().expr_ty(assignee).is_primitive_ty() {
+ match op.node {
+ hir::BinOpKind::Add
+ | hir::BinOpKind::Mul
+ | hir::BinOpKind::And
+ | hir::BinOpKind::Or
+ | hir::BinOpKind::BitXor
+ | hir::BinOpKind::BitAnd
+ | hir::BinOpKind::BitOr => {
+ lint(assignee, l);
+ },
+ _ => {},
+ }
+ }
+ }
+ }
+ },
+ _ => {},
+ }
+ }
+}
+
+fn lint_misrefactored_assign_op(
+ cx: &LateContext<'_>,
+ expr: &hir::Expr<'_>,
+ op: hir::BinOp,
+ rhs: &hir::Expr<'_>,
+ assignee: &hir::Expr<'_>,
+ rhs_other: &hir::Expr<'_>,
+) {
+ span_lint_and_then(
+ cx,
+ MISREFACTORED_ASSIGN_OP,
+ expr.span,
+ "variable appears on both sides of an assignment operation",
+ |diag| {
+ if let (Some(snip_a), Some(snip_r)) = (snippet_opt(cx, assignee.span), snippet_opt(cx, rhs_other.span)) {
+ let a = &sugg::Sugg::hir(cx, assignee, "..");
+ let r = &sugg::Sugg::hir(cx, rhs, "..");
+ let long = format!("{} = {}", snip_a, sugg::make_binop(op.node.into(), a, r));
+ diag.span_suggestion(
+ expr.span,
+ &format!(
+ "did you mean `{} = {} {} {}` or `{}`? Consider replacing it with",
+ snip_a,
+ snip_a,
+ op.node.as_str(),
+ snip_r,
+ long
+ ),
+ format!("{} {}= {}", snip_a, op.node.as_str(), snip_r),
+ Applicability::MaybeIncorrect,
+ );
+ diag.span_suggestion(
+ expr.span,
+ "or",
+ long,
+ Applicability::MaybeIncorrect, // snippet
+ );
+ }
+ },
+ );
+}
+
+#[must_use]
+fn is_commutative(op: hir::BinOpKind) -> bool {
+ use rustc_hir::BinOpKind::{
+ Add, And, BitAnd, BitOr, BitXor, Div, Eq, Ge, Gt, Le, Lt, Mul, Ne, Or, Rem, Shl, Shr, Sub,
+ };
+ match op {
+ Add | Mul | And | Or | BitXor | BitAnd | BitOr | Eq | Ne => true,
+ Sub | Div | Rem | Shl | Shr | Lt | Le | Ge | Gt => false,
+ }
+}
+
+struct ExprVisitor<'a, 'tcx> {
+ assignee: &'a hir::Expr<'a>,
+ counter: u8,
+ cx: &'a LateContext<'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for ExprVisitor<'a, 'tcx> {
+ fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) {
+ if eq_expr_value(self.cx, self.assignee, expr) {
+ self.counter += 1;
+ }
+
+ walk_expr(self, expr);
+ }
+}
--- /dev/null
- /// // Bad
+//! checks for attributes
+
+use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::macros::{is_panic, macro_backtrace};
+use clippy_utils::msrvs;
+use clippy_utils::source::{first_line_of_span, is_present_in_source, snippet_opt, without_block_comments};
+use clippy_utils::{extract_msrv_attr, meets_msrv};
+use if_chain::if_chain;
+use rustc_ast::{AttrKind, AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem};
+use rustc_errors::Applicability;
+use rustc_hir::{
+ Block, Expr, ExprKind, ImplItem, ImplItemKind, Item, ItemKind, StmtKind, TraitFn, TraitItem, TraitItemKind,
+};
+use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty;
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+use rustc_span::sym;
+use rustc_span::symbol::Symbol;
+use semver::Version;
+
+static UNIX_SYSTEMS: &[&str] = &[
+ "android",
+ "dragonfly",
+ "emscripten",
+ "freebsd",
+ "fuchsia",
+ "haiku",
+ "illumos",
+ "ios",
+ "l4re",
+ "linux",
+ "macos",
+ "netbsd",
+ "openbsd",
+ "redox",
+ "solaris",
+ "vxworks",
+];
+
+// NOTE: windows is excluded from the list because it's also a valid target family.
+static NON_UNIX_SYSTEMS: &[&str] = &["hermit", "none", "wasi"];
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for items annotated with `#[inline(always)]`,
+ /// unless the annotated function is empty or simply panics.
+ ///
+ /// ### Why is this bad?
+ /// While there are valid uses of this annotation (and once
+ /// you know when to use it, by all means `allow` this lint), it's a common
+ /// newbie-mistake to pepper one's code with it.
+ ///
+ /// As a rule of thumb, before slapping `#[inline(always)]` on a function,
+ /// measure if that additional function call really affects your runtime profile
+ /// sufficiently to make up for the increase in compile time.
+ ///
+ /// ### Known problems
+ /// False positives, big time. This lint is meant to be
+ /// deactivated by everyone doing serious performance work. This means having
+ /// done the measurement.
+ ///
+ /// ### Example
+ /// ```ignore
+ /// #[inline(always)]
+ /// fn not_quite_hot_code(..) { ... }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub INLINE_ALWAYS,
+ pedantic,
+ "use of `#[inline(always)]`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `extern crate` and `use` items annotated with
+ /// lint attributes.
+ ///
+ /// This lint permits `#[allow(unused_imports)]`, `#[allow(deprecated)]`,
+ /// `#[allow(unreachable_pub)]`, `#[allow(clippy::wildcard_imports)]` and
+ /// `#[allow(clippy::enum_glob_use)]` on `use` items and `#[allow(unused_imports)]` on
+ /// `extern crate` items with a `#[macro_use]` attribute.
+ ///
+ /// ### Why is this bad?
+ /// Lint attributes have no effect on crate imports. Most
+ /// likely a `!` was forgotten.
+ ///
+ /// ### Example
+ /// ```ignore
- /// // Ok
+ /// #[deny(dead_code)]
+ /// extern crate foo;
+ /// #[forbid(dead_code)]
+ /// use foo::bar;
++ /// ```
+ ///
- /// // Bad
- /// #[allow(dead_code)]
- ///
- /// fn not_quite_good_code() { }
++ /// Use instead:
++ /// ```rust,ignore
+ /// #[allow(unused_imports)]
+ /// use foo::baz;
+ /// #[allow(unused_imports)]
+ /// #[macro_use]
+ /// extern crate baz;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub USELESS_ATTRIBUTE,
+ correctness,
+ "use of lint attributes on `extern crate` items"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `#[deprecated]` annotations with a `since`
+ /// field that is not a valid semantic version.
+ ///
+ /// ### Why is this bad?
+ /// For checking the version of the deprecation, it must be
+ /// a valid semver. Failing that, the contained information is useless.
+ ///
+ /// ### Example
+ /// ```rust
+ /// #[deprecated(since = "forever")]
+ /// fn something_else() { /* ... */ }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DEPRECATED_SEMVER,
+ correctness,
+ "use of `#[deprecated(since = \"x\")]` where x is not semver"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for empty lines after outer attributes
+ ///
+ /// ### Why is this bad?
+ /// Most likely the attribute was meant to be an inner attribute using a '!'.
+ /// If it was meant to be an outer attribute, then the following item
+ /// should not be separated by empty lines.
+ ///
+ /// ### Known problems
+ /// Can cause false positives.
+ ///
+ /// From the clippy side it's difficult to detect empty lines between an attributes and the
+ /// following item because empty lines and comments are not part of the AST. The parsing
+ /// currently works for basic cases but is not perfect.
+ ///
+ /// ### Example
+ /// ```rust
++ /// #[allow(dead_code)]
++ ///
++ /// fn not_quite_good_code() { }
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
+ /// // Good (as inner attribute)
+ /// #![allow(dead_code)]
+ ///
+ /// fn this_is_fine() { }
+ ///
- /// Bad:
++ /// // or
+ ///
+ /// // Good (as outer attribute)
+ /// #[allow(dead_code)]
+ /// fn this_is_fine_too() { }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EMPTY_LINE_AFTER_OUTER_ATTR,
+ nursery,
+ "empty line after outer attribute"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `warn`/`deny`/`forbid` attributes targeting the whole clippy::restriction category.
+ ///
+ /// ### Why is this bad?
+ /// Restriction lints sometimes are in contrast with other lints or even go against idiomatic rust.
+ /// These lints should only be enabled on a lint-by-lint basis and with careful consideration.
+ ///
+ /// ### Example
- /// Good:
+ /// ```rust
+ /// #![deny(clippy::restriction)]
+ /// ```
+ ///
- /// Bad:
++ /// Use instead:
+ /// ```rust
+ /// #![deny(clippy::as_conversions)]
+ /// ```
+ #[clippy::version = "1.47.0"]
+ pub BLANKET_CLIPPY_RESTRICTION_LINTS,
+ suspicious,
+ "enabling the complete restriction group"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `#[cfg_attr(rustfmt, rustfmt_skip)]` and suggests to replace it
+ /// with `#[rustfmt::skip]`.
+ ///
+ /// ### Why is this bad?
+ /// Since tool_attributes ([rust-lang/rust#44690](https://github.com/rust-lang/rust/issues/44690))
+ /// are stable now, they should be used instead of the old `cfg_attr(rustfmt)` attributes.
+ ///
+ /// ### Known problems
+ /// This lint doesn't detect crate level inner attributes, because they get
+ /// processed before the PreExpansionPass lints get executed. See
+ /// [#3123](https://github.com/rust-lang/rust-clippy/pull/3123#issuecomment-422321765)
+ ///
+ /// ### Example
- /// Good:
+ /// ```rust
+ /// #[cfg_attr(rustfmt, rustfmt_skip)]
+ /// fn main() { }
+ /// ```
+ ///
- /// Bad:
++ /// Use instead:
+ /// ```rust
+ /// #[rustfmt::skip]
+ /// fn main() { }
+ /// ```
+ #[clippy::version = "1.32.0"]
+ pub DEPRECATED_CFG_ATTR,
+ complexity,
+ "usage of `cfg_attr(rustfmt)` instead of tool attributes"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for cfg attributes having operating systems used in target family position.
+ ///
+ /// ### Why is this bad?
+ /// The configuration option will not be recognised and the related item will not be included
+ /// by the conditional compilation engine.
+ ///
+ /// ### Example
- /// Good:
+ /// ```rust
+ /// #[cfg(linux)]
+ /// fn conditional() { }
+ /// ```
+ ///
- /// ```
++ /// Use instead:
+ /// ```rust
++ /// # mod hidden {
+ /// #[cfg(target_os = "linux")]
+ /// fn conditional() { }
- /// Or:
- /// ```rust
++ /// # }
++ ///
++ /// // or
+ ///
- /// Bad:
+ /// #[cfg(unix)]
+ /// fn conditional() { }
+ /// ```
+ /// Check the [Rust Reference](https://doc.rust-lang.org/reference/conditional-compilation.html#target_os) for more details.
+ #[clippy::version = "1.45.0"]
+ pub MISMATCHED_TARGET_OS,
+ correctness,
+ "usage of `cfg(operating_system)` instead of `cfg(target_os = \"operating_system\")`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for attributes that allow lints without a reason.
+ ///
+ /// (This requires the `lint_reasons` feature)
+ ///
+ /// ### Why is this bad?
+ /// Allowing a lint should always have a reason. This reason should be documented to
+ /// ensure that others understand the reasoning
+ ///
+ /// ### Example
- /// Good:
+ /// ```rust
+ /// #![feature(lint_reasons)]
+ ///
+ /// #![allow(clippy::some_lint)]
+ /// ```
+ ///
- for attr in &item.attrs {
++ /// Use instead:
+ /// ```rust
+ /// #![feature(lint_reasons)]
+ ///
+ /// #![allow(clippy::some_lint, reason = "False positive rust-lang/rust-clippy#1002020")]
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub ALLOW_ATTRIBUTES_WITHOUT_REASON,
+ restriction,
+ "ensures that all `allow` and `expect` attributes have a reason"
+}
+
+declare_lint_pass!(Attributes => [
+ ALLOW_ATTRIBUTES_WITHOUT_REASON,
+ INLINE_ALWAYS,
+ DEPRECATED_SEMVER,
+ USELESS_ATTRIBUTE,
+ BLANKET_CLIPPY_RESTRICTION_LINTS,
+]);
+
+impl<'tcx> LateLintPass<'tcx> for Attributes {
+ fn check_attribute(&mut self, cx: &LateContext<'tcx>, attr: &'tcx Attribute) {
+ if let Some(items) = &attr.meta_item_list() {
+ if let Some(ident) = attr.ident() {
+ if is_lint_level(ident.name) {
+ check_clippy_lint_names(cx, ident.name, items);
+ }
+ if matches!(ident.name, sym::allow | sym::expect) {
+ check_lint_reason(cx, ident.name, items, attr);
+ }
+ if items.is_empty() || !attr.has_name(sym::deprecated) {
+ return;
+ }
+ for item in items {
+ if_chain! {
+ if let NestedMetaItem::MetaItem(mi) = &item;
+ if let MetaItemKind::NameValue(lit) = &mi.kind;
+ if mi.has_name(sym::since);
+ then {
+ check_semver(cx, item.span(), lit);
+ }
+ }
+ }
+ }
+ }
+ }
+
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
+ let attrs = cx.tcx.hir().attrs(item.hir_id());
+ if is_relevant_item(cx, item) {
+ check_attrs(cx, item.span, item.ident.name, attrs);
+ }
+ match item.kind {
+ ItemKind::ExternCrate(..) | ItemKind::Use(..) => {
+ let skip_unused_imports = attrs.iter().any(|attr| attr.has_name(sym::macro_use));
+
+ for attr in attrs {
+ if in_external_macro(cx.sess(), attr.span) {
+ return;
+ }
+ if let Some(lint_list) = &attr.meta_item_list() {
+ if attr.ident().map_or(false, |ident| is_lint_level(ident.name)) {
+ for lint in lint_list {
+ match item.kind {
+ ItemKind::Use(..) => {
+ if is_word(lint, sym!(unused_imports))
+ || is_word(lint, sym::deprecated)
+ || is_word(lint, sym!(unreachable_pub))
+ || is_word(lint, sym!(unused))
+ || extract_clippy_lint(lint).map_or(false, |s| {
+ matches!(
+ s.as_str(),
+ "wildcard_imports" | "enum_glob_use" | "redundant_pub_crate",
+ )
+ })
+ {
+ return;
+ }
+ },
+ ItemKind::ExternCrate(..) => {
+ if is_word(lint, sym!(unused_imports)) && skip_unused_imports {
+ return;
+ }
+ if is_word(lint, sym!(unused_extern_crates)) {
+ return;
+ }
+ },
+ _ => {},
+ }
+ }
+ let line_span = first_line_of_span(cx, attr.span);
+
+ if let Some(mut sugg) = snippet_opt(cx, line_span) {
+ if sugg.contains("#[") {
+ span_lint_and_then(
+ cx,
+ USELESS_ATTRIBUTE,
+ line_span,
+ "useless lint attribute",
+ |diag| {
+ sugg = sugg.replacen("#[", "#![", 1);
+ diag.span_suggestion(
+ line_span,
+ "if you just forgot a `!`, use",
+ sugg,
+ Applicability::MaybeIncorrect,
+ );
+ },
+ );
+ }
+ }
+ }
+ }
+ }
+ },
+ _ => {},
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx ImplItem<'_>) {
+ if is_relevant_impl(cx, item) {
+ check_attrs(cx, item.span, item.ident.name, cx.tcx.hir().attrs(item.hir_id()));
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'_>) {
+ if is_relevant_trait(cx, item) {
+ check_attrs(cx, item.span, item.ident.name, cx.tcx.hir().attrs(item.hir_id()));
+ }
+ }
+}
+
+/// Returns the lint name if it is clippy lint.
+fn extract_clippy_lint(lint: &NestedMetaItem) -> Option<Symbol> {
+ if_chain! {
+ if let Some(meta_item) = lint.meta_item();
+ if meta_item.path.segments.len() > 1;
+ if let tool_name = meta_item.path.segments[0].ident;
+ if tool_name.name == sym::clippy;
+ then {
+ let lint_name = meta_item.path.segments.last().unwrap().ident.name;
+ return Some(lint_name);
+ }
+ }
+ None
+}
+
+fn check_clippy_lint_names(cx: &LateContext<'_>, name: Symbol, items: &[NestedMetaItem]) {
+ for lint in items {
+ if let Some(lint_name) = extract_clippy_lint(lint) {
+ if lint_name.as_str() == "restriction" && name != sym::allow {
+ span_lint_and_help(
+ cx,
+ BLANKET_CLIPPY_RESTRICTION_LINTS,
+ lint.span(),
+ "restriction lints are not meant to be all enabled",
+ None,
+ "try enabling only the lints you really need",
+ );
+ }
+ }
+ }
+}
+
+fn check_lint_reason(cx: &LateContext<'_>, name: Symbol, items: &[NestedMetaItem], attr: &'_ Attribute) {
+ // Check for the feature
+ if !cx.tcx.sess.features_untracked().lint_reasons {
+ return;
+ }
+
+ // Check if the reason is present
+ if let Some(item) = items.last().and_then(NestedMetaItem::meta_item)
+ && let MetaItemKind::NameValue(_) = &item.kind
+ && item.path == sym::reason
+ {
+ return;
+ }
+
+ span_lint_and_help(
+ cx,
+ ALLOW_ATTRIBUTES_WITHOUT_REASON,
+ attr.span,
+ &format!("`{}` attribute without specifying a reason", name.as_str()),
+ None,
+ "try adding a reason at the end with `, reason = \"..\"`",
+ );
+}
+
+fn is_relevant_item(cx: &LateContext<'_>, item: &Item<'_>) -> bool {
+ if let ItemKind::Fn(_, _, eid) = item.kind {
+ is_relevant_expr(cx, cx.tcx.typeck_body(eid), &cx.tcx.hir().body(eid).value)
+ } else {
+ true
+ }
+}
+
+fn is_relevant_impl(cx: &LateContext<'_>, item: &ImplItem<'_>) -> bool {
+ match item.kind {
+ ImplItemKind::Fn(_, eid) => is_relevant_expr(cx, cx.tcx.typeck_body(eid), &cx.tcx.hir().body(eid).value),
+ _ => false,
+ }
+}
+
+fn is_relevant_trait(cx: &LateContext<'_>, item: &TraitItem<'_>) -> bool {
+ match item.kind {
+ TraitItemKind::Fn(_, TraitFn::Required(_)) => true,
+ TraitItemKind::Fn(_, TraitFn::Provided(eid)) => {
+ is_relevant_expr(cx, cx.tcx.typeck_body(eid), &cx.tcx.hir().body(eid).value)
+ },
+ _ => false,
+ }
+}
+
+fn is_relevant_block(cx: &LateContext<'_>, typeck_results: &ty::TypeckResults<'_>, block: &Block<'_>) -> bool {
+ block.stmts.first().map_or(
+ block
+ .expr
+ .as_ref()
+ .map_or(false, |e| is_relevant_expr(cx, typeck_results, e)),
+ |stmt| match &stmt.kind {
+ StmtKind::Local(_) => true,
+ StmtKind::Expr(expr) | StmtKind::Semi(expr) => is_relevant_expr(cx, typeck_results, expr),
+ StmtKind::Item(_) => false,
+ },
+ )
+}
+
+fn is_relevant_expr(cx: &LateContext<'_>, typeck_results: &ty::TypeckResults<'_>, expr: &Expr<'_>) -> bool {
+ if macro_backtrace(expr.span).last().map_or(false, |macro_call| {
+ is_panic(cx, macro_call.def_id) || cx.tcx.item_name(macro_call.def_id) == sym::unreachable
+ }) {
+ return false;
+ }
+ match &expr.kind {
+ ExprKind::Block(block, _) => is_relevant_block(cx, typeck_results, block),
+ ExprKind::Ret(Some(e)) => is_relevant_expr(cx, typeck_results, e),
+ ExprKind::Ret(None) | ExprKind::Break(_, None) => false,
+ _ => true,
+ }
+}
+
+fn check_attrs(cx: &LateContext<'_>, span: Span, name: Symbol, attrs: &[Attribute]) {
+ if span.from_expansion() {
+ return;
+ }
+
+ for attr in attrs {
+ if let Some(values) = attr.meta_item_list() {
+ if values.len() != 1 || !attr.has_name(sym::inline) {
+ continue;
+ }
+ if is_word(&values[0], sym::always) {
+ span_lint(
+ cx,
+ INLINE_ALWAYS,
+ attr.span,
+ &format!(
+ "you have declared `#[inline(always)]` on `{}`. This is usually a bad idea",
+ name
+ ),
+ );
+ }
+ }
+ }
+}
+
+fn check_semver(cx: &LateContext<'_>, span: Span, lit: &Lit) {
+ if let LitKind::Str(is, _) = lit.kind {
+ if Version::parse(is.as_str()).is_ok() {
+ return;
+ }
+ }
+ span_lint(
+ cx,
+ DEPRECATED_SEMVER,
+ span,
+ "the since field must contain a semver-compliant version",
+ );
+}
+
+fn is_word(nmi: &NestedMetaItem, expected: Symbol) -> bool {
+ if let NestedMetaItem::MetaItem(mi) = &nmi {
+ mi.is_word() && mi.has_name(expected)
+ } else {
+ false
+ }
+}
+
+pub struct EarlyAttributes {
+ pub msrv: Option<RustcVersion>,
+}
+
+impl_lint_pass!(EarlyAttributes => [
+ DEPRECATED_CFG_ATTR,
+ MISMATCHED_TARGET_OS,
+ EMPTY_LINE_AFTER_OUTER_ATTR,
+]);
+
+impl EarlyLintPass for EarlyAttributes {
+ fn check_item(&mut self, cx: &EarlyContext<'_>, item: &rustc_ast::Item) {
+ check_empty_line_after_outer_attr(cx, item);
+ }
+
+ fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) {
+ check_deprecated_cfg_attr(cx, attr, self.msrv);
+ check_mismatched_target_os(cx, attr);
+ }
+
+ extract_msrv_attr!(EarlyContext);
+}
+
+fn check_empty_line_after_outer_attr(cx: &EarlyContext<'_>, item: &rustc_ast::Item) {
- let end_of_attr_to_item = Span::new(attr.span.hi(), item.span.lo(), item.span.ctxt(), item.span.parent());
++ let mut iter = item.attrs.iter().peekable();
++ while let Some(attr) = iter.next() {
+ if matches!(attr.kind, AttrKind::Normal(..))
+ && attr.style == AttrStyle::Outer
+ && is_present_in_source(cx, attr.span)
+ {
+ let begin_of_attr_to_item = Span::new(attr.span.lo(), item.span.lo(), item.span.ctxt(), item.span.parent());
- if let Some(snippet) = snippet_opt(cx, end_of_attr_to_item) {
++ let end_of_attr_to_next_attr_or_item = Span::new(
++ attr.span.hi(),
++ iter.peek().map_or(item.span.lo(), |next_attr| next_attr.span.lo()),
++ item.span.ctxt(),
++ item.span.parent(),
++ );
+
- if skip_item.has_name(sym!(rustfmt_skip)) ||
- skip_item.path.segments.last().expect("empty path in attribute").ident.name == sym::skip;
++ if let Some(snippet) = snippet_opt(cx, end_of_attr_to_next_attr_or_item) {
+ let lines = snippet.split('\n').collect::<Vec<_>>();
+ let lines = without_block_comments(lines);
+
+ if lines.iter().filter(|l| l.trim().is_empty()).count() > 2 {
+ span_lint(
+ cx,
+ EMPTY_LINE_AFTER_OUTER_ATTR,
+ begin_of_attr_to_item,
+ "found an empty line after an outer attribute. \
+ Perhaps you forgot to add a `!` to make it an inner attribute?",
+ );
+ }
+ }
+ }
+ }
+}
+
+fn check_deprecated_cfg_attr(cx: &EarlyContext<'_>, attr: &Attribute, msrv: Option<RustcVersion>) {
+ if_chain! {
+ if meets_msrv(msrv, msrvs::TOOL_ATTRIBUTES);
+ // check cfg_attr
+ if attr.has_name(sym::cfg_attr);
+ if let Some(items) = attr.meta_item_list();
+ if items.len() == 2;
+ // check for `rustfmt`
+ if let Some(feature_item) = items[0].meta_item();
+ if feature_item.has_name(sym::rustfmt);
+ // check for `rustfmt_skip` and `rustfmt::skip`
+ if let Some(skip_item) = &items[1].meta_item();
++ if skip_item.has_name(sym!(rustfmt_skip))
++ || skip_item
++ .path
++ .segments
++ .last()
++ .expect("empty path in attribute")
++ .ident
++ .name
++ == sym::skip;
+ // Only lint outer attributes, because custom inner attributes are unstable
+ // Tracking issue: https://github.com/rust-lang/rust/issues/54726
+ if attr.style == AttrStyle::Outer;
+ then {
+ span_lint_and_sugg(
+ cx,
+ DEPRECATED_CFG_ATTR,
+ attr.span,
+ "`cfg_attr` is deprecated for rustfmt and got replaced by tool attributes",
+ "use",
+ "#[rustfmt::skip]".to_string(),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+}
+
+fn check_mismatched_target_os(cx: &EarlyContext<'_>, attr: &Attribute) {
+ fn find_os(name: &str) -> Option<&'static str> {
+ UNIX_SYSTEMS
+ .iter()
+ .chain(NON_UNIX_SYSTEMS.iter())
+ .find(|&&os| os == name)
+ .copied()
+ }
+
+ fn is_unix(name: &str) -> bool {
+ UNIX_SYSTEMS.iter().any(|&os| os == name)
+ }
+
+ fn find_mismatched_target_os(items: &[NestedMetaItem]) -> Vec<(&str, Span)> {
+ let mut mismatched = Vec::new();
+
+ for item in items {
+ if let NestedMetaItem::MetaItem(meta) = item {
+ match &meta.kind {
+ MetaItemKind::List(list) => {
+ mismatched.extend(find_mismatched_target_os(list));
+ },
+ MetaItemKind::Word => {
+ if_chain! {
+ if let Some(ident) = meta.ident();
+ if let Some(os) = find_os(ident.name.as_str());
+ then {
+ mismatched.push((os, ident.span));
+ }
+ }
+ },
+ MetaItemKind::NameValue(..) => {},
+ }
+ }
+ }
+
+ mismatched
+ }
+
+ if_chain! {
+ if attr.has_name(sym::cfg);
+ if let Some(list) = attr.meta_item_list();
+ let mismatched = find_mismatched_target_os(&list);
+ if !mismatched.is_empty();
+ then {
+ let mess = "operating system used in target family position";
+
+ span_lint_and_then(cx, MISMATCHED_TARGET_OS, attr.span, mess, |diag| {
+ // Avoid showing the unix suggestion multiple times in case
+ // we have more than one mismatch for unix-like systems
+ let mut unix_suggested = false;
+
+ for (os, span) in mismatched {
+ let sugg = format!("target_os = \"{}\"", os);
+ diag.span_suggestion(span, "try", sugg, Applicability::MaybeIncorrect);
+
+ if !unix_suggested && is_unix(os) {
+ diag.help("did you mean `unix`?");
+ unix_suggested = true;
+ }
+ }
+ });
+ }
+ }
+}
+
+fn is_lint_level(symbol: Symbol) -> bool {
+ matches!(symbol, sym::allow | sym::expect | sym::warn | sym::deny | sym::forbid)
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg};
+use clippy_utils::get_parent_expr;
+use clippy_utils::higher;
+use clippy_utils::source::snippet_block_with_applicability;
+use clippy_utils::ty::implements_trait;
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::{walk_expr, Visitor};
+use rustc_hir::{BlockCheckMode, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `if` conditions that use blocks containing an
+ /// expression, statements or conditions that use closures with blocks.
+ ///
+ /// ### Why is this bad?
+ /// Style, using blocks in the condition makes it hard to read.
+ ///
+ /// ### Examples
+ /// ```rust
- /// // Good
- /// if true { /* ... */ }
++ /// # fn somefunc() -> bool { true };
+ /// if { true } { /* ... */ }
+ ///
- /// // or
- ///
++ /// if { let x = somefunc(); x } { /* ... */ }
+ /// ```
+ ///
- /// // Bad
- /// if { let x = somefunc(); x } { /* ... */ }
++ /// Use instead:
+ /// ```rust
+ /// # fn somefunc() -> bool { true };
- /// // Good
++ /// if true { /* ... */ }
+ ///
+ /// let res = { let x = somefunc(); x };
+ /// if res { /* ... */ }
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub BLOCKS_IN_IF_CONDITIONS,
+ style,
+ "useless or complex blocks that can be eliminated in conditions"
+}
+
+declare_lint_pass!(BlocksInIfConditions => [BLOCKS_IN_IF_CONDITIONS]);
+
+struct ExVisitor<'a, 'tcx> {
+ found_block: Option<&'tcx Expr<'tcx>>,
+ cx: &'a LateContext<'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for ExVisitor<'a, 'tcx> {
+ fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
+ if let ExprKind::Closure(_, _, eid, _, _) = expr.kind {
+ // do not lint if the closure is called using an iterator (see #1141)
+ if_chain! {
+ if let Some(parent) = get_parent_expr(self.cx, expr);
+ if let ExprKind::MethodCall(_, [self_arg, ..], _) = &parent.kind;
+ let caller = self.cx.typeck_results().expr_ty(self_arg);
+ if let Some(iter_id) = self.cx.tcx.get_diagnostic_item(sym::Iterator);
+ if implements_trait(self.cx, caller, iter_id, &[]);
+ then {
+ return;
+ }
+ }
+
+ let body = self.cx.tcx.hir().body(eid);
+ let ex = &body.value;
+ if let ExprKind::Block(block, _) = ex.kind {
+ if !body.value.span.from_expansion() && !block.stmts.is_empty() {
+ self.found_block = Some(ex);
+ return;
+ }
+ }
+ }
+ walk_expr(self, expr);
+ }
+}
+
+const BRACED_EXPR_MESSAGE: &str = "omit braces around single expression condition";
+const COMPLEX_BLOCK_MESSAGE: &str = "in an `if` condition, avoid complex blocks or closures with blocks; \
+ instead, move the block or closure higher and bind it with a `let`";
+
+impl<'tcx> LateLintPass<'tcx> for BlocksInIfConditions {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+ if let Some(higher::If { cond, .. }) = higher::If::hir(expr) {
+ if let ExprKind::Block(block, _) = &cond.kind {
+ if block.rules == BlockCheckMode::DefaultBlock {
+ if block.stmts.is_empty() {
+ if let Some(ex) = &block.expr {
+ // don't dig into the expression here, just suggest that they remove
+ // the block
+ if expr.span.from_expansion() || ex.span.from_expansion() {
+ return;
+ }
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ BLOCKS_IN_IF_CONDITIONS,
+ cond.span,
+ BRACED_EXPR_MESSAGE,
+ "try",
+ format!(
+ "{}",
+ snippet_block_with_applicability(
+ cx,
+ ex.span,
+ "..",
+ Some(expr.span),
+ &mut applicability
+ )
+ ),
+ applicability,
+ );
+ }
+ } else {
+ let span = block.expr.as_ref().map_or_else(|| block.stmts[0].span, |e| e.span);
+ if span.from_expansion() || expr.span.from_expansion() {
+ return;
+ }
+ // move block higher
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ BLOCKS_IN_IF_CONDITIONS,
+ expr.span.with_hi(cond.span.hi()),
+ COMPLEX_BLOCK_MESSAGE,
+ "try",
+ format!(
+ "let res = {}; if res",
+ snippet_block_with_applicability(
+ cx,
+ block.span,
+ "..",
+ Some(expr.span),
+ &mut applicability
+ ),
+ ),
+ applicability,
+ );
+ }
+ }
+ } else {
+ let mut visitor = ExVisitor { found_block: None, cx };
+ walk_expr(&mut visitor, cond);
+ if let Some(block) = visitor.found_block {
+ span_lint(cx, BLOCKS_IN_IF_CONDITIONS, block.span, COMPLEX_BLOCK_MESSAGE);
+ }
+ }
+ }
+ }
+}
--- /dev/null
- /// if a && true // should be: if a
- /// if !(a == b) // should be: if a != b
+use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::source::snippet_opt;
+use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
+use clippy_utils::{eq_expr_value, get_trait_def_id, paths};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::{walk_expr, FnKind, Visitor};
+use rustc_hir::{BinOpKind, Body, Expr, ExprKind, FnDecl, HirId, UnOp};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for boolean expressions that can be written more
+ /// concisely.
+ ///
+ /// ### Why is this bad?
+ /// Readability of boolean expressions suffers from
+ /// unnecessary duplication.
+ ///
+ /// ### Known problems
+ /// Ignores short circuiting behavior of `||` and
+ /// `&&`. Ignores `|`, `&` and `^`.
+ ///
+ /// ### Example
+ /// ```ignore
- /// ```ignore
++ /// if a && true {}
++ /// if !(a == b) {}
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust,ignore
++ /// if a {}
++ /// if a != b {}
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NONMINIMAL_BOOL,
+ complexity,
+ "boolean expressions that can be written more concisely"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for boolean expressions that contain terminals that
+ /// can be eliminated.
+ ///
+ /// ### Why is this bad?
+ /// This is most likely a logic bug.
+ ///
+ /// ### Known problems
+ /// Ignores short circuiting behavior.
+ ///
+ /// ### Example
- /// The `b` is unnecessary, the expression is equivalent to `if a`.
++ /// ```rust,ignore
++ /// // The `b` is unnecessary, the expression is equivalent to `if a`.
+ /// if a && b || a { ... }
+ /// ```
++ ///
++ /// Use instead:
++ /// ```rust,ignore
++ /// if a {}
++ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub LOGIC_BUG,
+ correctness,
+ "boolean expressions that contain terminals which can be eliminated"
+}
+
+// For each pairs, both orders are considered.
+const METHODS_WITH_NEGATION: [(&str, &str); 2] = [("is_some", "is_none"), ("is_err", "is_ok")];
+
+declare_lint_pass!(NonminimalBool => [NONMINIMAL_BOOL, LOGIC_BUG]);
+
+impl<'tcx> LateLintPass<'tcx> for NonminimalBool {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ _: FnKind<'tcx>,
+ _: &'tcx FnDecl<'_>,
+ body: &'tcx Body<'_>,
+ _: Span,
+ _: HirId,
+ ) {
+ NonminimalBoolVisitor { cx }.visit_body(body);
+ }
+}
+
+struct NonminimalBoolVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+}
+
+use quine_mc_cluskey::Bool;
+struct Hir2Qmm<'a, 'tcx, 'v> {
+ terminals: Vec<&'v Expr<'v>>,
+ cx: &'a LateContext<'tcx>,
+}
+
+impl<'a, 'tcx, 'v> Hir2Qmm<'a, 'tcx, 'v> {
+ fn extract(&mut self, op: BinOpKind, a: &[&'v Expr<'_>], mut v: Vec<Bool>) -> Result<Vec<Bool>, String> {
+ for a in a {
+ if let ExprKind::Binary(binop, lhs, rhs) = &a.kind {
+ if binop.node == op {
+ v = self.extract(op, &[lhs, rhs], v)?;
+ continue;
+ }
+ }
+ v.push(self.run(a)?);
+ }
+ Ok(v)
+ }
+
+ fn run(&mut self, e: &'v Expr<'_>) -> Result<Bool, String> {
+ fn negate(bin_op_kind: BinOpKind) -> Option<BinOpKind> {
+ match bin_op_kind {
+ BinOpKind::Eq => Some(BinOpKind::Ne),
+ BinOpKind::Ne => Some(BinOpKind::Eq),
+ BinOpKind::Gt => Some(BinOpKind::Le),
+ BinOpKind::Ge => Some(BinOpKind::Lt),
+ BinOpKind::Lt => Some(BinOpKind::Ge),
+ BinOpKind::Le => Some(BinOpKind::Gt),
+ _ => None,
+ }
+ }
+
+ // prevent folding of `cfg!` macros and the like
+ if !e.span.from_expansion() {
+ match &e.kind {
+ ExprKind::Unary(UnOp::Not, inner) => return Ok(Bool::Not(Box::new(self.run(inner)?))),
+ ExprKind::Binary(binop, lhs, rhs) => match &binop.node {
+ BinOpKind::Or => {
+ return Ok(Bool::Or(self.extract(BinOpKind::Or, &[lhs, rhs], Vec::new())?));
+ },
+ BinOpKind::And => {
+ return Ok(Bool::And(self.extract(BinOpKind::And, &[lhs, rhs], Vec::new())?));
+ },
+ _ => (),
+ },
+ ExprKind::Lit(lit) => match lit.node {
+ LitKind::Bool(true) => return Ok(Bool::True),
+ LitKind::Bool(false) => return Ok(Bool::False),
+ _ => (),
+ },
+ _ => (),
+ }
+ }
+ for (n, expr) in self.terminals.iter().enumerate() {
+ if eq_expr_value(self.cx, e, expr) {
+ #[expect(clippy::cast_possible_truncation)]
+ return Ok(Bool::Term(n as u8));
+ }
+
+ if_chain! {
+ if let ExprKind::Binary(e_binop, e_lhs, e_rhs) = &e.kind;
+ if implements_ord(self.cx, e_lhs);
+ if let ExprKind::Binary(expr_binop, expr_lhs, expr_rhs) = &expr.kind;
+ if negate(e_binop.node) == Some(expr_binop.node);
+ if eq_expr_value(self.cx, e_lhs, expr_lhs);
+ if eq_expr_value(self.cx, e_rhs, expr_rhs);
+ then {
+ #[expect(clippy::cast_possible_truncation)]
+ return Ok(Bool::Not(Box::new(Bool::Term(n as u8))));
+ }
+ }
+ }
+ let n = self.terminals.len();
+ self.terminals.push(e);
+ if n < 32 {
+ #[expect(clippy::cast_possible_truncation)]
+ Ok(Bool::Term(n as u8))
+ } else {
+ Err("too many literals".to_owned())
+ }
+ }
+}
+
+struct SuggestContext<'a, 'tcx, 'v> {
+ terminals: &'v [&'v Expr<'v>],
+ cx: &'a LateContext<'tcx>,
+ output: String,
+}
+
+impl<'a, 'tcx, 'v> SuggestContext<'a, 'tcx, 'v> {
+ fn recurse(&mut self, suggestion: &Bool) -> Option<()> {
+ use quine_mc_cluskey::Bool::{And, False, Not, Or, Term, True};
+ match suggestion {
+ True => {
+ self.output.push_str("true");
+ },
+ False => {
+ self.output.push_str("false");
+ },
+ Not(inner) => match **inner {
+ And(_) | Or(_) => {
+ self.output.push('!');
+ self.output.push('(');
+ self.recurse(inner);
+ self.output.push(')');
+ },
+ Term(n) => {
+ let terminal = self.terminals[n as usize];
+ if let Some(str) = simplify_not(self.cx, terminal) {
+ self.output.push_str(&str);
+ } else {
+ self.output.push('!');
+ let snip = snippet_opt(self.cx, terminal.span)?;
+ self.output.push_str(&snip);
+ }
+ },
+ True | False | Not(_) => {
+ self.output.push('!');
+ self.recurse(inner)?;
+ },
+ },
+ And(v) => {
+ for (index, inner) in v.iter().enumerate() {
+ if index > 0 {
+ self.output.push_str(" && ");
+ }
+ if let Or(_) = *inner {
+ self.output.push('(');
+ self.recurse(inner);
+ self.output.push(')');
+ } else {
+ self.recurse(inner);
+ }
+ }
+ },
+ Or(v) => {
+ for (index, inner) in v.iter().rev().enumerate() {
+ if index > 0 {
+ self.output.push_str(" || ");
+ }
+ self.recurse(inner);
+ }
+ },
+ &Term(n) => {
+ let snip = snippet_opt(self.cx, self.terminals[n as usize].span)?;
+ self.output.push_str(&snip);
+ },
+ }
+ Some(())
+ }
+}
+
+fn simplify_not(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<String> {
+ match &expr.kind {
+ ExprKind::Binary(binop, lhs, rhs) => {
+ if !implements_ord(cx, lhs) {
+ return None;
+ }
+
+ match binop.node {
+ BinOpKind::Eq => Some(" != "),
+ BinOpKind::Ne => Some(" == "),
+ BinOpKind::Lt => Some(" >= "),
+ BinOpKind::Gt => Some(" <= "),
+ BinOpKind::Le => Some(" > "),
+ BinOpKind::Ge => Some(" < "),
+ _ => None,
+ }
+ .and_then(|op| {
+ Some(format!(
+ "{}{}{}",
+ snippet_opt(cx, lhs.span)?,
+ op,
+ snippet_opt(cx, rhs.span)?
+ ))
+ })
+ },
+ ExprKind::MethodCall(path, args, _) if args.len() == 1 => {
+ let type_of_receiver = cx.typeck_results().expr_ty(&args[0]);
+ if !is_type_diagnostic_item(cx, type_of_receiver, sym::Option)
+ && !is_type_diagnostic_item(cx, type_of_receiver, sym::Result)
+ {
+ return None;
+ }
+ METHODS_WITH_NEGATION
+ .iter()
+ .copied()
+ .flat_map(|(a, b)| vec![(a, b), (b, a)])
+ .find(|&(a, _)| {
+ let path: &str = path.ident.name.as_str();
+ a == path
+ })
+ .and_then(|(_, neg_method)| Some(format!("{}.{}()", snippet_opt(cx, args[0].span)?, neg_method)))
+ },
+ _ => None,
+ }
+}
+
+fn suggest(cx: &LateContext<'_>, suggestion: &Bool, terminals: &[&Expr<'_>]) -> String {
+ let mut suggest_context = SuggestContext {
+ terminals,
+ cx,
+ output: String::new(),
+ };
+ suggest_context.recurse(suggestion);
+ suggest_context.output
+}
+
+fn simple_negate(b: Bool) -> Bool {
+ use quine_mc_cluskey::Bool::{And, False, Not, Or, Term, True};
+ match b {
+ True => False,
+ False => True,
+ t @ Term(_) => Not(Box::new(t)),
+ And(mut v) => {
+ for el in &mut v {
+ *el = simple_negate(::std::mem::replace(el, True));
+ }
+ Or(v)
+ },
+ Or(mut v) => {
+ for el in &mut v {
+ *el = simple_negate(::std::mem::replace(el, True));
+ }
+ And(v)
+ },
+ Not(inner) => *inner,
+ }
+}
+
+#[derive(Default)]
+struct Stats {
+ terminals: [usize; 32],
+ negations: usize,
+ ops: usize,
+}
+
+fn terminal_stats(b: &Bool) -> Stats {
+ fn recurse(b: &Bool, stats: &mut Stats) {
+ match b {
+ True | False => stats.ops += 1,
+ Not(inner) => {
+ match **inner {
+ And(_) | Or(_) => stats.ops += 1, // brackets are also operations
+ _ => stats.negations += 1,
+ }
+ recurse(inner, stats);
+ },
+ And(v) | Or(v) => {
+ stats.ops += v.len() - 1;
+ for inner in v {
+ recurse(inner, stats);
+ }
+ },
+ &Term(n) => stats.terminals[n as usize] += 1,
+ }
+ }
+ use quine_mc_cluskey::Bool::{And, False, Not, Or, Term, True};
+ let mut stats = Stats::default();
+ recurse(b, &mut stats);
+ stats
+}
+
+impl<'a, 'tcx> NonminimalBoolVisitor<'a, 'tcx> {
+ fn bool_expr(&self, e: &'tcx Expr<'_>) {
+ let mut h2q = Hir2Qmm {
+ terminals: Vec::new(),
+ cx: self.cx,
+ };
+ if let Ok(expr) = h2q.run(e) {
+ if h2q.terminals.len() > 8 {
+ // QMC has exponentially slow behavior as the number of terminals increases
+ // 8 is reasonable, it takes approximately 0.2 seconds.
+ // See #825
+ return;
+ }
+
+ let stats = terminal_stats(&expr);
+ let mut simplified = expr.simplify();
+ for simple in Bool::Not(Box::new(expr)).simplify() {
+ match simple {
+ Bool::Not(_) | Bool::True | Bool::False => {},
+ _ => simplified.push(Bool::Not(Box::new(simple.clone()))),
+ }
+ let simple_negated = simple_negate(simple);
+ if simplified.iter().any(|s| *s == simple_negated) {
+ continue;
+ }
+ simplified.push(simple_negated);
+ }
+ let mut improvements = Vec::with_capacity(simplified.len());
+ 'simplified: for suggestion in &simplified {
+ let simplified_stats = terminal_stats(suggestion);
+ let mut improvement = false;
+ for i in 0..32 {
+ // ignore any "simplifications" that end up requiring a terminal more often
+ // than in the original expression
+ if stats.terminals[i] < simplified_stats.terminals[i] {
+ continue 'simplified;
+ }
+ if stats.terminals[i] != 0 && simplified_stats.terminals[i] == 0 {
+ span_lint_and_then(
+ self.cx,
+ LOGIC_BUG,
+ e.span,
+ "this boolean expression contains a logic bug",
+ |diag| {
+ diag.span_help(
+ h2q.terminals[i].span,
+ "this expression can be optimized out by applying boolean operations to the \
+ outer expression",
+ );
+ diag.span_suggestion(
+ e.span,
+ "it would look like the following",
+ suggest(self.cx, suggestion, &h2q.terminals),
+ // nonminimal_bool can produce minimal but
+ // not human readable expressions (#3141)
+ Applicability::Unspecified,
+ );
+ },
+ );
+ // don't also lint `NONMINIMAL_BOOL`
+ return;
+ }
+ // if the number of occurrences of a terminal decreases or any of the stats
+ // decreases while none increases
+ improvement |= (stats.terminals[i] > simplified_stats.terminals[i])
+ || (stats.negations > simplified_stats.negations && stats.ops == simplified_stats.ops)
+ || (stats.ops > simplified_stats.ops && stats.negations == simplified_stats.negations);
+ }
+ if improvement {
+ improvements.push(suggestion);
+ }
+ }
+ let nonminimal_bool_lint = |suggestions: Vec<_>| {
+ span_lint_and_then(
+ self.cx,
+ NONMINIMAL_BOOL,
+ e.span,
+ "this boolean expression can be simplified",
+ |diag| {
+ diag.span_suggestions(
+ e.span,
+ "try",
+ suggestions.into_iter(),
+ // nonminimal_bool can produce minimal but
+ // not human readable expressions (#3141)
+ Applicability::Unspecified,
+ );
+ },
+ );
+ };
+ if improvements.is_empty() {
+ let mut visitor = NotSimplificationVisitor { cx: self.cx };
+ visitor.visit_expr(e);
+ } else {
+ nonminimal_bool_lint(
+ improvements
+ .into_iter()
+ .map(|suggestion| suggest(self.cx, suggestion, &h2q.terminals))
+ .collect(),
+ );
+ }
+ }
+ }
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for NonminimalBoolVisitor<'a, 'tcx> {
+ fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
+ if !e.span.from_expansion() {
+ match &e.kind {
+ ExprKind::Binary(binop, _, _) if binop.node == BinOpKind::Or || binop.node == BinOpKind::And => {
+ self.bool_expr(e);
+ },
+ ExprKind::Unary(UnOp::Not, inner) => {
+ if self.cx.typeck_results().node_types()[inner.hir_id].is_bool() {
+ self.bool_expr(e);
+ }
+ },
+ _ => {},
+ }
+ }
+ walk_expr(self, e);
+ }
+}
+
+fn implements_ord<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>) -> bool {
+ let ty = cx.typeck_results().expr_ty(expr);
+ get_trait_def_id(cx, &paths::ORD).map_or(false, |id| implements_trait(cx, ty, id, &[]))
+}
+
+struct NotSimplificationVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for NotSimplificationVisitor<'a, 'tcx> {
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if let ExprKind::Unary(UnOp::Not, inner) = &expr.kind {
+ if let Some(suggestion) = simplify_not(self.cx, inner) {
+ span_lint_and_sugg(
+ self.cx,
+ NONMINIMAL_BOOL,
+ expr.span,
+ "this boolean expression can be simplified",
+ "try",
+ suggestion,
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+
+ walk_expr(self, expr);
+ }
+}
--- /dev/null
--- /dev/null
++use crate::reference::DEREF_ADDROF;
++use clippy_utils::diagnostics::span_lint_and_then;
++use clippy_utils::source::snippet_opt;
++use clippy_utils::ty::implements_trait;
++use clippy_utils::{get_parent_expr, is_lint_allowed};
++use rustc_errors::Applicability;
++use rustc_hir::{ExprKind, UnOp};
++use rustc_lint::{LateContext, LateLintPass};
++use rustc_middle::mir::Mutability;
++use rustc_middle::ty;
++use rustc_session::{declare_lint_pass, declare_tool_lint};
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for `&*(&T)`.
++ ///
++ /// ### Why is this bad?
++ /// Dereferencing and then borrowing a reference value has no effect in most cases.
++ ///
++ /// ### Known problems
++ /// false negative on such code:
++ /// ```
++ /// let x = &12;
++ /// let addr_x = &x as *const _ as usize;
++ /// let addr_y = &&*x as *const _ as usize; // assert ok now, and lint triggerd.
++ /// // But if we fix it, assert will fail.
++ /// assert_ne!(addr_x, addr_y);
++ /// ```
++ ///
++ /// ### Example
++ /// ```rust
++ /// let s = &String::new();
++ ///
++ /// // Bad
++ /// let a: &String = &* s;
++ /// foo(&*s);
++ ///
++ /// // Good
++ /// let a: &String = s;
++ /// foo(&**s);
++ ///
++ /// fn foo(_: &str){ }
++ /// ```
++ #[clippy::version = "1.59.0"]
++ pub BORROW_DEREF_REF,
++ complexity,
++ "deref on an immutable reference returns the same type as itself"
++}
++
++declare_lint_pass!(BorrowDerefRef => [BORROW_DEREF_REF]);
++
++impl LateLintPass<'_> for BorrowDerefRef {
++ fn check_expr(&mut self, cx: &LateContext<'_>, e: &rustc_hir::Expr<'_>) {
++ if_chain! {
++ if !e.span.from_expansion();
++ if let ExprKind::AddrOf(_, Mutability::Not, addrof_target) = e.kind;
++ if !addrof_target.span.from_expansion();
++ if let ExprKind::Unary(UnOp::Deref, deref_target) = addrof_target.kind;
++ if !deref_target.span.from_expansion();
++ if !matches!(deref_target.kind, ExprKind::Unary(UnOp::Deref, ..) );
++ let ref_ty = cx.typeck_results().expr_ty(deref_target);
++ if let ty::Ref(_, inner_ty, Mutability::Not) = ref_ty.kind();
++ then{
++
++ if let Some(parent_expr) = get_parent_expr(cx, e){
++ if matches!(parent_expr.kind, ExprKind::Unary(UnOp::Deref, ..)) &&
++ !is_lint_allowed(cx, DEREF_ADDROF, parent_expr.hir_id) {
++ return;
++ }
++
++ // modification to `&mut &*x` is different from `&mut x`
++ if matches!(deref_target.kind, ExprKind::Path(..)
++ | ExprKind::Field(..)
++ | ExprKind::Index(..)
++ | ExprKind::Unary(UnOp::Deref, ..))
++ && matches!(parent_expr.kind, ExprKind::AddrOf(_, Mutability::Mut, _)) {
++ return;
++ }
++ }
++
++ span_lint_and_then(
++ cx,
++ BORROW_DEREF_REF,
++ e.span,
++ "deref on an immutable reference",
++ |diag| {
++ diag.span_suggestion(
++ e.span,
++ "if you would like to reborrow, try removing `&*`",
++ snippet_opt(cx, deref_target.span).unwrap(),
++ Applicability::MachineApplicable
++ );
++
++ // has deref trait -> give 2 help
++ // doesn't have deref trait -> give 1 help
++ if let Some(deref_trait_id) = cx.tcx.lang_items().deref_trait(){
++ if !implements_trait(cx, *inner_ty, deref_trait_id, &[]) {
++ return;
++ }
++ }
++
++ diag.span_suggestion(
++ e.span,
++ "if you would like to deref, try using `&**`",
++ format!(
++ "&**{}",
++ &snippet_opt(cx, deref_target.span).unwrap(),
++ ),
++ Applicability::MaybeIncorrect
++ );
++
++ }
++ );
++
++ }
++ }
++ }
++}
--- /dev/null
- /// &vec.iter().filter(|x| **x == 0u8).count(); // use bytecount::count instead
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::ty::match_type;
+use clippy_utils::visitors::is_local_used;
+use clippy_utils::{path_to_local_id, paths, peel_blocks, peel_ref_operators, strip_pat_refs};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind, PatKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, UintTy};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for naive byte counts
+ ///
+ /// ### Why is this bad?
+ /// The [`bytecount`](https://crates.io/crates/bytecount)
+ /// crate has methods to count your bytes faster, especially for large slices.
+ ///
+ /// ### Known problems
+ /// If you have predominantly small slices, the
+ /// `bytecount::count(..)` method may actually be slower. However, if you can
+ /// ensure that less than 2³²-1 matches arise, the `naive_count_32(..)` can be
+ /// faster in those cases.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let vec = vec![1_u8];
++ /// let count = vec.iter().filter(|x| **x == 0u8).count();
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust,ignore
++ /// # let vec = vec![1_u8];
++ /// let count = bytecount::count(&vec, 0u8);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NAIVE_BYTECOUNT,
+ pedantic,
+ "use of naive `<slice>.filter(|&x| x == y).count()` to count byte values"
+}
+
+declare_lint_pass!(ByteCount => [NAIVE_BYTECOUNT]);
+
+impl<'tcx> LateLintPass<'tcx> for ByteCount {
+ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::MethodCall(count, [count_recv], _) = expr.kind;
+ if count.ident.name == sym::count;
+ if let ExprKind::MethodCall(filter, [filter_recv, filter_arg], _) = count_recv.kind;
+ if filter.ident.name == sym!(filter);
+ if let ExprKind::Closure(_, _, body_id, _, _) = filter_arg.kind;
+ let body = cx.tcx.hir().body(body_id);
+ if let [param] = body.params;
+ if let PatKind::Binding(_, arg_id, _, _) = strip_pat_refs(param.pat).kind;
+ if let ExprKind::Binary(ref op, l, r) = body.value.kind;
+ if op.node == BinOpKind::Eq;
+ if match_type(cx,
+ cx.typeck_results().expr_ty(filter_recv).peel_refs(),
+ &paths::SLICE_ITER);
+ let operand_is_arg = |expr| {
+ let expr = peel_ref_operators(cx, peel_blocks(expr));
+ path_to_local_id(expr, arg_id)
+ };
+ let needle = if operand_is_arg(l) {
+ r
+ } else if operand_is_arg(r) {
+ l
+ } else {
+ return;
+ };
+ if ty::Uint(UintTy::U8) == *cx.typeck_results().expr_ty(needle).peel_refs().kind();
+ if !is_local_used(cx, needle, arg_id);
+ then {
+ let haystack = if let ExprKind::MethodCall(path, args, _) =
+ filter_recv.kind {
+ let p = path.ident.name;
+ if (p == sym::iter || p == sym!(iter_mut)) && args.len() == 1 {
+ &args[0]
+ } else {
+ filter_recv
+ }
+ } else {
+ filter_recv
+ };
+ let mut applicability = Applicability::MaybeIncorrect;
+ span_lint_and_sugg(
+ cx,
+ NAIVE_BYTECOUNT,
+ expr.span,
+ "you appear to be counting bytes the naive way",
+ "consider using the bytecount crate",
+ format!("bytecount::count({}, {})",
+ snippet_with_applicability(cx, haystack.span, "..", &mut applicability),
+ snippet_with_applicability(cx, needle.span, "..", &mut applicability)),
+ applicability,
+ );
+ }
+ };
+ }
+}
--- /dev/null
- use if_chain::if_chain;
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::sugg::Sugg;
+use clippy_utils::{meets_msrv, msrvs};
- use rustc_middle::ty::Ty;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::LateContext;
- if_chain! {
- if meets_msrv(msrv, msrvs::UNSIGNED_ABS);
- if cast_from.is_integral();
- if cast_to.is_integral();
- if cast_from.is_signed();
- if !cast_to.is_signed();
- if let ExprKind::MethodCall(method_path, args, _) = cast_expr.kind;
- if let method_name = method_path.ident.name.as_str();
- if method_name == "abs";
- then {
- span_lint_and_sugg(
- cx,
- CAST_ABS_TO_UNSIGNED,
- expr.span,
- &format!("casting the result of `{}::{}()` to {}", cast_from, method_name, cast_to),
- "replace with",
- format!("{}.unsigned_abs()", Sugg::hir(cx, &args[0], "..")),
- Applicability::MachineApplicable,
- );
- }
++use rustc_middle::ty::{self, Ty};
+use rustc_semver::RustcVersion;
+
+use super::CAST_ABS_TO_UNSIGNED;
+
+pub(super) fn check(
+ cx: &LateContext<'_>,
+ expr: &Expr<'_>,
+ cast_expr: &Expr<'_>,
+ cast_from: Ty<'_>,
+ cast_to: Ty<'_>,
+ msrv: Option<RustcVersion>,
+) {
++ if meets_msrv(msrv, msrvs::UNSIGNED_ABS)
++ && let ty::Int(from) = cast_from.kind()
++ && let ty::Uint(to) = cast_to.kind()
++ && let ExprKind::MethodCall(method_path, args, _) = cast_expr.kind
++ && method_path.ident.name.as_str() == "abs"
++ {
++ let span = if from.bit_width() == to.bit_width() {
++ expr.span
++ } else {
++ // if the result of `.unsigned_abs` would be a different type, keep the cast
++ // e.g. `i64 -> usize`, `i16 -> u8`
++ cast_expr.span
++ };
++
++ span_lint_and_sugg(
++ cx,
++ CAST_ABS_TO_UNSIGNED,
++ span,
++ &format!("casting the result of `{cast_from}::abs()` to {cast_to}"),
++ "replace with",
++ format!("{}.unsigned_abs()", Sugg::hir(cx, &args[0], "..")),
++ Applicability::MachineApplicable,
++ );
+ }
+}
--- /dev/null
- if let [int] = &*tp.segments;
+//! lint on manually implemented checked conversions that could be transformed into `try_from`
+
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::{meets_msrv, msrvs, SpanlessEq};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOp, BinOpKind, Expr, ExprKind, QPath, TyKind};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for explicit bounds checking when casting.
+ ///
+ /// ### Why is this bad?
+ /// Reduces the readability of statements & is error prone.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let foo: u32 = 5;
+ /// # let _ =
+ /// foo <= i32::MAX as u32
+ /// # ;
+ /// ```
+ ///
+ /// Could be written:
+ ///
+ /// ```rust
+ /// # let foo = 1;
+ /// # let _ =
+ /// i32::try_from(foo).is_ok()
+ /// # ;
+ /// ```
+ #[clippy::version = "1.37.0"]
+ pub CHECKED_CONVERSIONS,
+ pedantic,
+ "`try_from` could replace manual bounds checking when casting"
+}
+
+pub struct CheckedConversions {
+ msrv: Option<RustcVersion>,
+}
+
+impl CheckedConversions {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self { msrv }
+ }
+}
+
+impl_lint_pass!(CheckedConversions => [CHECKED_CONVERSIONS]);
+
+impl<'tcx> LateLintPass<'tcx> for CheckedConversions {
+ fn check_expr(&mut self, cx: &LateContext<'_>, item: &Expr<'_>) {
+ if !meets_msrv(self.msrv, msrvs::TRY_FROM) {
+ return;
+ }
+
+ let result = if_chain! {
+ if !in_external_macro(cx.sess(), item.span);
+ if let ExprKind::Binary(op, left, right) = &item.kind;
+
+ then {
+ match op.node {
+ BinOpKind::Ge | BinOpKind::Le => single_check(item),
+ BinOpKind::And => double_check(cx, left, right),
+ _ => None,
+ }
+ } else {
+ None
+ }
+ };
+
+ if let Some(cv) = result {
+ if let Some(to_type) = cv.to_type {
+ let mut applicability = Applicability::MachineApplicable;
+ let snippet = snippet_with_applicability(cx, cv.expr_to_cast.span, "_", &mut applicability);
+ span_lint_and_sugg(
+ cx,
+ CHECKED_CONVERSIONS,
+ item.span,
+ "checked cast can be simplified",
+ "try",
+ format!("{}::try_from({}).is_ok()", to_type, snippet),
+ applicability,
+ );
+ }
+ }
+ }
+
+ extract_msrv_attr!(LateContext);
+}
+
+/// Searches for a single check from unsigned to _ is done
+/// todo: check for case signed -> larger unsigned == only x >= 0
+fn single_check<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<Conversion<'tcx>> {
+ check_upper_bound(expr).filter(|cv| cv.cvt == ConversionType::FromUnsigned)
+}
+
+/// Searches for a combination of upper & lower bound checks
+fn double_check<'a>(cx: &LateContext<'_>, left: &'a Expr<'_>, right: &'a Expr<'_>) -> Option<Conversion<'a>> {
+ let upper_lower = |l, r| {
+ let upper = check_upper_bound(l);
+ let lower = check_lower_bound(r);
+
+ upper.zip(lower).and_then(|(l, r)| l.combine(r, cx))
+ };
+
+ upper_lower(left, right).or_else(|| upper_lower(right, left))
+}
+
+/// Contains the result of a tried conversion check
+#[derive(Clone, Debug)]
+struct Conversion<'a> {
+ cvt: ConversionType,
+ expr_to_cast: &'a Expr<'a>,
+ to_type: Option<&'a str>,
+}
+
+/// The kind of conversion that is checked
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+enum ConversionType {
+ SignedToUnsigned,
+ SignedToSigned,
+ FromUnsigned,
+}
+
+impl<'a> Conversion<'a> {
+ /// Combine multiple conversions if the are compatible
+ pub fn combine(self, other: Self, cx: &LateContext<'_>) -> Option<Conversion<'a>> {
+ if self.is_compatible(&other, cx) {
+ // Prefer a Conversion that contains a type-constraint
+ Some(if self.to_type.is_some() { self } else { other })
+ } else {
+ None
+ }
+ }
+
+ /// Checks if two conversions are compatible
+ /// same type of conversion, same 'castee' and same 'to type'
+ pub fn is_compatible(&self, other: &Self, cx: &LateContext<'_>) -> bool {
+ (self.cvt == other.cvt)
+ && (SpanlessEq::new(cx).eq_expr(self.expr_to_cast, other.expr_to_cast))
+ && (self.has_compatible_to_type(other))
+ }
+
+ /// Checks if the to-type is the same (if there is a type constraint)
+ fn has_compatible_to_type(&self, other: &Self) -> bool {
+ match (self.to_type, other.to_type) {
+ (Some(l), Some(r)) => l == r,
+ _ => true,
+ }
+ }
+
+ /// Try to construct a new conversion if the conversion type is valid
+ fn try_new(expr_to_cast: &'a Expr<'_>, from_type: &str, to_type: &'a str) -> Option<Conversion<'a>> {
+ ConversionType::try_new(from_type, to_type).map(|cvt| Conversion {
+ cvt,
+ expr_to_cast,
+ to_type: Some(to_type),
+ })
+ }
+
+ /// Construct a new conversion without type constraint
+ fn new_any(expr_to_cast: &'a Expr<'_>) -> Conversion<'a> {
+ Conversion {
+ cvt: ConversionType::SignedToUnsigned,
+ expr_to_cast,
+ to_type: None,
+ }
+ }
+}
+
+impl ConversionType {
+ /// Creates a conversion type if the type is allowed & conversion is valid
+ #[must_use]
+ fn try_new(from: &str, to: &str) -> Option<Self> {
+ if UINTS.contains(&from) {
+ Some(Self::FromUnsigned)
+ } else if SINTS.contains(&from) {
+ if UINTS.contains(&to) {
+ Some(Self::SignedToUnsigned)
+ } else if SINTS.contains(&to) {
+ Some(Self::SignedToSigned)
+ } else {
+ None
+ }
+ } else {
+ None
+ }
+ }
+}
+
+/// Check for `expr <= (to_type::MAX as from_type)`
+fn check_upper_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<Conversion<'tcx>> {
+ if_chain! {
+ if let ExprKind::Binary(ref op, left, right) = &expr.kind;
+ if let Some((candidate, check)) = normalize_le_ge(op, left, right);
+ if let Some((from, to)) = get_types_from_cast(check, INTS, "max_value", "MAX");
+
+ then {
+ Conversion::try_new(candidate, from, to)
+ } else {
+ None
+ }
+ }
+}
+
+/// Check for `expr >= 0|(to_type::MIN as from_type)`
+fn check_lower_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<Conversion<'tcx>> {
+ fn check_function<'a>(candidate: &'a Expr<'a>, check: &'a Expr<'a>) -> Option<Conversion<'a>> {
+ (check_lower_bound_zero(candidate, check)).or_else(|| (check_lower_bound_min(candidate, check)))
+ }
+
+ // First of we need a binary containing the expression & the cast
+ if let ExprKind::Binary(ref op, left, right) = &expr.kind {
+ normalize_le_ge(op, right, left).and_then(|(l, r)| check_function(l, r))
+ } else {
+ None
+ }
+}
+
+/// Check for `expr >= 0`
+fn check_lower_bound_zero<'a>(candidate: &'a Expr<'_>, check: &'a Expr<'_>) -> Option<Conversion<'a>> {
+ if_chain! {
+ if let ExprKind::Lit(ref lit) = &check.kind;
+ if let LitKind::Int(0, _) = &lit.node;
+
+ then {
+ Some(Conversion::new_any(candidate))
+ } else {
+ None
+ }
+ }
+}
+
+/// Check for `expr >= (to_type::MIN as from_type)`
+fn check_lower_bound_min<'a>(candidate: &'a Expr<'_>, check: &'a Expr<'_>) -> Option<Conversion<'a>> {
+ if let Some((from, to)) = get_types_from_cast(check, SINTS, "min_value", "MIN") {
+ Conversion::try_new(candidate, from, to)
+ } else {
+ None
+ }
+}
+
+/// Tries to extract the from- and to-type from a cast expression
+fn get_types_from_cast<'a>(
+ expr: &'a Expr<'_>,
+ types: &'a [&str],
+ func: &'a str,
+ assoc_const: &'a str,
+) -> Option<(&'a str, &'a str)> {
+ // `to_type::max_value() as from_type`
+ // or `to_type::MAX as from_type`
+ let call_from_cast: Option<(&Expr<'_>, &str)> = if_chain! {
+ // to_type::max_value(), from_type
+ if let ExprKind::Cast(limit, from_type) = &expr.kind;
+ if let TyKind::Path(ref from_type_path) = &from_type.kind;
+ if let Some(from_sym) = int_ty_to_sym(from_type_path);
+
+ then {
+ Some((limit, from_sym))
+ } else {
+ None
+ }
+ };
+
+ // `from_type::from(to_type::max_value())`
+ let limit_from: Option<(&Expr<'_>, &str)> = call_from_cast.or_else(|| {
+ if_chain! {
+ // `from_type::from, to_type::max_value()`
+ if let ExprKind::Call(from_func, args) = &expr.kind;
+ // `to_type::max_value()`
+ if args.len() == 1;
+ if let limit = &args[0];
+ // `from_type::from`
+ if let ExprKind::Path(ref path) = &from_func.kind;
+ if let Some(from_sym) = get_implementing_type(path, INTS, "from");
+
+ then {
+ Some((limit, from_sym))
+ } else {
+ None
+ }
+ }
+ });
+
+ if let Some((limit, from_type)) = limit_from {
+ match limit.kind {
+ // `from_type::from(_)`
+ ExprKind::Call(path, _) => {
+ if let ExprKind::Path(ref path) = path.kind {
+ // `to_type`
+ if let Some(to_type) = get_implementing_type(path, types, func) {
+ return Some((from_type, to_type));
+ }
+ }
+ },
+ // `to_type::MAX`
+ ExprKind::Path(ref path) => {
+ if let Some(to_type) = get_implementing_type(path, types, assoc_const) {
+ return Some((from_type, to_type));
+ }
+ },
+ _ => {},
+ }
+ };
+ None
+}
+
+/// Gets the type which implements the called function
+fn get_implementing_type<'a>(path: &QPath<'_>, candidates: &'a [&str], function: &str) -> Option<&'a str> {
+ if_chain! {
+ if let QPath::TypeRelative(ty, path) = &path;
+ if path.ident.name.as_str() == function;
+ if let TyKind::Path(QPath::Resolved(None, tp)) = &ty.kind;
- if let [ty] = &*path.segments;
++ if let [int] = tp.segments;
+ then {
+ let name = int.ident.name.as_str();
+ candidates.iter().find(|c| &name == *c).copied()
+ } else {
+ None
+ }
+ }
+}
+
+/// Gets the type as a string, if it is a supported integer
+fn int_ty_to_sym<'tcx>(path: &QPath<'_>) -> Option<&'tcx str> {
+ if_chain! {
+ if let QPath::Resolved(_, path) = *path;
++ if let [ty] = path.segments;
+ then {
+ let name = ty.ident.name.as_str();
+ INTS.iter().find(|c| &name == *c).copied()
+ } else {
+ None
+ }
+ }
+}
+
+/// Will return the expressions as if they were expr1 <= expr2
+fn normalize_le_ge<'a>(op: &BinOp, left: &'a Expr<'a>, right: &'a Expr<'a>) -> Option<(&'a Expr<'a>, &'a Expr<'a>)> {
+ match op.node {
+ BinOpKind::Le => Some((left, right)),
+ BinOpKind::Ge => Some((right, left)),
+ _ => None,
+ }
+}
+
+// Constants
+const UINTS: &[&str] = &["u8", "u16", "u32", "u64", "usize"];
+const SINTS: &[&str] = &["i8", "i16", "i32", "i64", "isize"];
+const INTS: &[&str] = &["u8", "u16", "u32", "u64", "usize", "i8", "i16", "i32", "i64", "isize"];
--- /dev/null
- /// No. You'll see it when you get the warning.
+//! calculate cognitive complexity and warn about overly complex functions
+
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::source::snippet_opt;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::LimitStack;
+use rustc_ast::ast::Attribute;
+use rustc_hir::intravisit::{walk_expr, FnKind, Visitor};
+use rustc_hir::{Body, Expr, ExprKind, FnDecl, HirId};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+use rustc_span::{sym, BytePos};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for methods with high cognitive complexity.
+ ///
+ /// ### Why is this bad?
+ /// Methods of high cognitive complexity tend to be hard to
+ /// both read and maintain. Also LLVM will tend to optimize small methods better.
+ ///
+ /// ### Known problems
+ /// Sometimes it's hard to find a way to reduce the
+ /// complexity.
+ ///
+ /// ### Example
++ /// You'll see it when you get the warning.
+ #[clippy::version = "1.35.0"]
+ pub COGNITIVE_COMPLEXITY,
+ nursery,
+ "functions that should be split up into multiple functions"
+}
+
+pub struct CognitiveComplexity {
+ limit: LimitStack,
+}
+
+impl CognitiveComplexity {
+ #[must_use]
+ pub fn new(limit: u64) -> Self {
+ Self {
+ limit: LimitStack::new(limit),
+ }
+ }
+}
+
+impl_lint_pass!(CognitiveComplexity => [COGNITIVE_COMPLEXITY]);
+
+impl CognitiveComplexity {
+ #[expect(clippy::cast_possible_truncation)]
+ fn check<'tcx>(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ kind: FnKind<'tcx>,
+ decl: &'tcx FnDecl<'_>,
+ body: &'tcx Body<'_>,
+ body_span: Span,
+ ) {
+ if body_span.from_expansion() {
+ return;
+ }
+
+ let expr = &body.value;
+
+ let mut helper = CcHelper { cc: 1, returns: 0 };
+ helper.visit_expr(expr);
+ let CcHelper { cc, returns } = helper;
+ let ret_ty = cx.typeck_results().node_type(expr.hir_id);
+ let ret_adjust = if is_type_diagnostic_item(cx, ret_ty, sym::Result) {
+ returns
+ } else {
+ #[expect(clippy::integer_division)]
+ (returns / 2)
+ };
+
+ let mut rust_cc = cc;
+ // prevent degenerate cases where unreachable code contains `return` statements
+ if rust_cc >= ret_adjust {
+ rust_cc -= ret_adjust;
+ }
+
+ if rust_cc > self.limit.limit() {
+ let fn_span = match kind {
+ FnKind::ItemFn(ident, _, _) | FnKind::Method(ident, _) => ident.span,
+ FnKind::Closure => {
+ let header_span = body_span.with_hi(decl.output.span().lo());
+ let pos = snippet_opt(cx, header_span).and_then(|snip| {
+ let low_offset = snip.find('|')?;
+ let high_offset = 1 + snip.get(low_offset + 1..)?.find('|')?;
+ let low = header_span.lo() + BytePos(low_offset as u32);
+ let high = low + BytePos(high_offset as u32 + 1);
+
+ Some((low, high))
+ });
+
+ if let Some((low, high)) = pos {
+ Span::new(low, high, header_span.ctxt(), header_span.parent())
+ } else {
+ return;
+ }
+ },
+ };
+
+ span_lint_and_help(
+ cx,
+ COGNITIVE_COMPLEXITY,
+ fn_span,
+ &format!(
+ "the function has a cognitive complexity of ({}/{})",
+ rust_cc,
+ self.limit.limit()
+ ),
+ None,
+ "you could split it up into multiple smaller functions",
+ );
+ }
+ }
+}
+
+impl<'tcx> LateLintPass<'tcx> for CognitiveComplexity {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ kind: FnKind<'tcx>,
+ decl: &'tcx FnDecl<'_>,
+ body: &'tcx Body<'_>,
+ span: Span,
+ hir_id: HirId,
+ ) {
+ let def_id = cx.tcx.hir().local_def_id(hir_id);
+ if !cx.tcx.has_attr(def_id.to_def_id(), sym::test) {
+ self.check(cx, kind, decl, body, span);
+ }
+ }
+
+ fn enter_lint_attrs(&mut self, cx: &LateContext<'tcx>, attrs: &'tcx [Attribute]) {
+ self.limit.push_attrs(cx.sess(), attrs, "cognitive_complexity");
+ }
+ fn exit_lint_attrs(&mut self, cx: &LateContext<'tcx>, attrs: &'tcx [Attribute]) {
+ self.limit.pop_attrs(cx.sess(), attrs, "cognitive_complexity");
+ }
+}
+
+struct CcHelper {
+ cc: u64,
+ returns: u64,
+}
+
+impl<'tcx> Visitor<'tcx> for CcHelper {
+ fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
+ walk_expr(self, e);
+ match e.kind {
+ ExprKind::If(_, _, _) => {
+ self.cc += 1;
+ },
+ ExprKind::Match(_, arms, _) => {
+ if arms.len() > 1 {
+ self.cc += 1;
+ }
+ self.cc += arms.iter().filter(|arm| arm.guard.is_some()).count() as u64;
+ },
+ ExprKind::Ret(_) => self.returns += 1,
+ _ => {},
+ }
+ }
+}
--- /dev/null
- /// Should be written:
+//! Checks for if expressions that contain only an if expression.
+//!
+//! For example, the lint would catch:
+//!
+//! ```rust,ignore
+//! if x {
+//! if y {
+//! println!("Hello world");
+//! }
+//! }
+//! ```
+//!
+//! This lint is **warn** by default
+
+use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::source::{snippet, snippet_block, snippet_block_with_applicability};
+use clippy_utils::sugg::Sugg;
+use if_chain::if_chain;
+use rustc_ast::ast;
+use rustc_errors::Applicability;
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::Span;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for nested `if` statements which can be collapsed
+ /// by `&&`-combining their conditions.
+ ///
+ /// ### Why is this bad?
+ /// Each `if`-statement adds one level of nesting, which
+ /// makes code look more complex than it really is.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// if x {
+ /// if y {
+ /// …
+ /// }
+ /// }
+ ///
+ /// ```
+ ///
++ /// Use instead:
+ ///
+ /// ```rust,ignore
+ /// if x && y {
+ /// …
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub COLLAPSIBLE_IF,
+ style,
+ "nested `if`s that can be collapsed (e.g., `if x { if y { ... } }`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for collapsible `else { if ... }` expressions
+ /// that can be collapsed to `else if ...`.
+ ///
+ /// ### Why is this bad?
+ /// Each `if`-statement adds one level of nesting, which
+ /// makes code look more complex than it really is.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ ///
+ /// if x {
+ /// …
+ /// } else {
+ /// if y {
+ /// …
+ /// }
+ /// }
+ /// ```
+ ///
+ /// Should be written:
+ ///
+ /// ```rust,ignore
+ /// if x {
+ /// …
+ /// } else if y {
+ /// …
+ /// }
+ /// ```
+ #[clippy::version = "1.51.0"]
+ pub COLLAPSIBLE_ELSE_IF,
+ style,
+ "nested `else`-`if` expressions that can be collapsed (e.g., `else { if x { ... } }`)"
+}
+
+declare_lint_pass!(CollapsibleIf => [COLLAPSIBLE_IF, COLLAPSIBLE_ELSE_IF]);
+
+impl EarlyLintPass for CollapsibleIf {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
+ if !expr.span.from_expansion() {
+ check_if(cx, expr);
+ }
+ }
+}
+
+fn check_if(cx: &EarlyContext<'_>, expr: &ast::Expr) {
+ if let ast::ExprKind::If(check, then, else_) = &expr.kind {
+ if let Some(else_) = else_ {
+ check_collapsible_maybe_if_let(cx, then.span, else_);
+ } else if let ast::ExprKind::Let(..) = check.kind {
+ // Prevent triggering on `if let a = b { if c { .. } }`.
+ } else {
+ check_collapsible_no_if_let(cx, expr, check, then);
+ }
+ }
+}
+
+fn block_starts_with_comment(cx: &EarlyContext<'_>, expr: &ast::Block) -> bool {
+ // We trim all opening braces and whitespaces and then check if the next string is a comment.
+ let trimmed_block_text = snippet_block(cx, expr.span, "..", None)
+ .trim_start_matches(|c: char| c.is_whitespace() || c == '{')
+ .to_owned();
+ trimmed_block_text.starts_with("//") || trimmed_block_text.starts_with("/*")
+}
+
+fn check_collapsible_maybe_if_let(cx: &EarlyContext<'_>, then_span: Span, else_: &ast::Expr) {
+ if_chain! {
+ if let ast::ExprKind::Block(ref block, _) = else_.kind;
+ if !block_starts_with_comment(cx, block);
+ if let Some(else_) = expr_block(block);
+ if else_.attrs.is_empty();
+ if !else_.span.from_expansion();
+ if let ast::ExprKind::If(..) = else_.kind;
+ then {
+ // Prevent "elseif"
+ // Check that the "else" is followed by whitespace
+ let up_to_else = then_span.between(block.span);
+ let requires_space = if let Some(c) = snippet(cx, up_to_else, "..").chars().last() { !c.is_whitespace() } else { false };
+
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ COLLAPSIBLE_ELSE_IF,
+ block.span,
+ "this `else { if .. }` block can be collapsed",
+ "collapse nested if block",
+ format!(
+ "{}{}",
+ if requires_space { " " } else { "" },
+ snippet_block_with_applicability(cx, else_.span, "..", Some(block.span), &mut applicability)
+ ),
+ applicability,
+ );
+ }
+ }
+}
+
+fn check_collapsible_no_if_let(cx: &EarlyContext<'_>, expr: &ast::Expr, check: &ast::Expr, then: &ast::Block) {
+ if_chain! {
+ if !block_starts_with_comment(cx, then);
+ if let Some(inner) = expr_block(then);
+ if inner.attrs.is_empty();
+ if let ast::ExprKind::If(ref check_inner, ref content, None) = inner.kind;
+ // Prevent triggering on `if c { if let a = b { .. } }`.
+ if !matches!(check_inner.kind, ast::ExprKind::Let(..));
+ if expr.span.ctxt() == inner.span.ctxt();
+ then {
+ span_lint_and_then(cx, COLLAPSIBLE_IF, expr.span, "this `if` statement can be collapsed", |diag| {
+ let lhs = Sugg::ast(cx, check, "..");
+ let rhs = Sugg::ast(cx, check_inner, "..");
+ diag.span_suggestion(
+ expr.span,
+ "collapse nested if block",
+ format!(
+ "if {} {}",
+ lhs.and(&rhs),
+ snippet_block(cx, content.span, "..", Some(expr.span)),
+ ),
+ Applicability::MachineApplicable, // snippet
+ );
+ });
+ }
+ }
+}
+
+/// If the block contains only one expression, return it.
+fn expr_block(block: &ast::Block) -> Option<&ast::Expr> {
+ let mut it = block.stmts.iter();
+
+ if let (Some(stmt), None) = (it.next(), it.next()) {
+ match stmt.kind {
+ ast::StmtKind::Expr(ref expr) | ast::StmtKind::Semi(ref expr) => Some(expr),
+ _ => None,
+ }
+ } else {
+ None
+ }
+}
--- /dev/null
- /// Could be written:
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::ty::implements_trait;
+use clippy_utils::{get_trait_def_id, if_sequence, in_constant, is_else_clause, paths, SpanlessEq};
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks comparison chains written with `if` that can be
+ /// rewritten with `match` and `cmp`.
+ ///
+ /// ### Why is this bad?
+ /// `if` is not guaranteed to be exhaustive and conditionals can get
+ /// repetitive
+ ///
+ /// ### Known problems
+ /// The match statement may be slower due to the compiler
+ /// not inlining the call to cmp. See issue [#5354](https://github.com/rust-lang/rust-clippy/issues/5354)
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// # fn a() {}
+ /// # fn b() {}
+ /// # fn c() {}
+ /// fn f(x: u8, y: u8) {
+ /// if x > y {
+ /// a()
+ /// } else if x < y {
+ /// b()
+ /// } else {
+ /// c()
+ /// }
+ /// }
+ /// ```
+ ///
++ /// Use instead:
+ ///
+ /// ```rust,ignore
+ /// use std::cmp::Ordering;
+ /// # fn a() {}
+ /// # fn b() {}
+ /// # fn c() {}
+ /// fn f(x: u8, y: u8) {
+ /// match x.cmp(&y) {
+ /// Ordering::Greater => a(),
+ /// Ordering::Less => b(),
+ /// Ordering::Equal => c()
+ /// }
+ /// }
+ /// ```
+ #[clippy::version = "1.40.0"]
+ pub COMPARISON_CHAIN,
+ style,
+ "`if`s that can be rewritten with `match` and `cmp`"
+}
+
+declare_lint_pass!(ComparisonChain => [COMPARISON_CHAIN]);
+
+impl<'tcx> LateLintPass<'tcx> for ComparisonChain {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if expr.span.from_expansion() {
+ return;
+ }
+
+ // We only care about the top-most `if` in the chain
+ if is_else_clause(cx.tcx, expr) {
+ return;
+ }
+
+ if in_constant(cx, expr.hir_id) {
+ return;
+ }
+
+ // Check that there exists at least one explicit else condition
+ let (conds, _) = if_sequence(expr);
+ if conds.len() < 2 {
+ return;
+ }
+
+ for cond in conds.windows(2) {
+ if let (&ExprKind::Binary(ref kind1, lhs1, rhs1), &ExprKind::Binary(ref kind2, lhs2, rhs2)) =
+ (&cond[0].kind, &cond[1].kind)
+ {
+ if !kind_is_cmp(kind1.node) || !kind_is_cmp(kind2.node) {
+ return;
+ }
+
+ // Check that both sets of operands are equal
+ let mut spanless_eq = SpanlessEq::new(cx);
+ let same_fixed_operands = spanless_eq.eq_expr(lhs1, lhs2) && spanless_eq.eq_expr(rhs1, rhs2);
+ let same_transposed_operands = spanless_eq.eq_expr(lhs1, rhs2) && spanless_eq.eq_expr(rhs1, lhs2);
+
+ if !same_fixed_operands && !same_transposed_operands {
+ return;
+ }
+
+ // Check that if the operation is the same, either it's not `==` or the operands are transposed
+ if kind1.node == kind2.node {
+ if kind1.node == BinOpKind::Eq {
+ return;
+ }
+ if !same_transposed_operands {
+ return;
+ }
+ }
+
+ // Check that the type being compared implements `core::cmp::Ord`
+ let ty = cx.typeck_results().expr_ty(lhs1);
+ let is_ord = get_trait_def_id(cx, &paths::ORD).map_or(false, |id| implements_trait(cx, ty, id, &[]));
+
+ if !is_ord {
+ return;
+ }
+ } else {
+ // We only care about comparison chains
+ return;
+ }
+ }
+ span_lint_and_help(
+ cx,
+ COMPARISON_CHAIN,
+ expr.span,
+ "`if` chain can be rewritten with `match`",
+ None,
+ "consider rewriting the `if` chain to use `cmp` and `match`",
+ );
+ }
+}
+
+fn kind_is_cmp(kind: BinOpKind) -> bool {
+ matches!(kind, BinOpKind::Lt | BinOpKind::Gt | BinOpKind::Eq)
+}
--- /dev/null
- /// Could be written as:
+use clippy_utils::diagnostics::{span_lint_and_note, span_lint_and_then};
+use clippy_utils::source::{first_line_of_span, indent_of, reindent_multiline, snippet, snippet_opt};
+use clippy_utils::{
+ both, count_eq, eq_expr_value, get_enclosing_block, get_parent_expr, if_sequence, is_else_clause, is_lint_allowed,
+ search_same, ContainsName, SpanlessEq, SpanlessHash,
+};
+use if_chain::if_chain;
+use rustc_data_structures::fx::FxHashSet;
+use rustc_errors::{Applicability, Diagnostic};
+use rustc_hir::intravisit::{self, Visitor};
+use rustc_hir::{Block, Expr, ExprKind, HirId};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::nested_filter;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::{source_map::Span, symbol::Symbol, BytePos};
+use std::borrow::Cow;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for consecutive `if`s with the same condition.
+ ///
+ /// ### Why is this bad?
+ /// This is probably a copy & paste error.
+ ///
+ /// ### Example
+ /// ```ignore
+ /// if a == b {
+ /// …
+ /// } else if a == b {
+ /// …
+ /// }
+ /// ```
+ ///
+ /// Note that this lint ignores all conditions with a function call as it could
+ /// have side effects:
+ ///
+ /// ```ignore
+ /// if foo() {
+ /// …
+ /// } else if foo() { // not linted
+ /// …
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub IFS_SAME_COND,
+ correctness,
+ "consecutive `if`s with the same condition"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for consecutive `if`s with the same function call.
+ ///
+ /// ### Why is this bad?
+ /// This is probably a copy & paste error.
+ /// Despite the fact that function can have side effects and `if` works as
+ /// intended, such an approach is implicit and can be considered a "code smell".
+ ///
+ /// ### Example
+ /// ```ignore
+ /// if foo() == bar {
+ /// …
+ /// } else if foo() == bar {
+ /// …
+ /// }
+ /// ```
+ ///
+ /// This probably should be:
+ /// ```ignore
+ /// if foo() == bar {
+ /// …
+ /// } else if foo() == baz {
+ /// …
+ /// }
+ /// ```
+ ///
+ /// or if the original code was not a typo and called function mutates a state,
+ /// consider move the mutation out of the `if` condition to avoid similarity to
+ /// a copy & paste error:
+ ///
+ /// ```ignore
+ /// let first = foo();
+ /// if first == bar {
+ /// …
+ /// } else {
+ /// let second = foo();
+ /// if second == bar {
+ /// …
+ /// }
+ /// }
+ /// ```
+ #[clippy::version = "1.41.0"]
+ pub SAME_FUNCTIONS_IN_IF_CONDITION,
+ pedantic,
+ "consecutive `if`s with the same function call"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `if/else` with the same body as the *then* part
+ /// and the *else* part.
+ ///
+ /// ### Why is this bad?
+ /// This is probably a copy & paste error.
+ ///
+ /// ### Example
+ /// ```ignore
+ /// let foo = if … {
+ /// 42
+ /// } else {
+ /// 42
+ /// };
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub IF_SAME_THEN_ELSE,
+ correctness,
+ "`if` with the same `then` and `else` blocks"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks if the `if` and `else` block contain shared code that can be
+ /// moved out of the blocks.
+ ///
+ /// ### Why is this bad?
+ /// Duplicate code is less maintainable.
+ ///
+ /// ### Known problems
+ /// * The lint doesn't check if the moved expressions modify values that are being used in
+ /// the if condition. The suggestion can in that case modify the behavior of the program.
+ /// See [rust-clippy#7452](https://github.com/rust-lang/rust-clippy/issues/7452)
+ ///
+ /// ### Example
+ /// ```ignore
+ /// let foo = if … {
+ /// println!("Hello World");
+ /// 13
+ /// } else {
+ /// println!("Hello World");
+ /// 42
+ /// };
+ /// ```
+ ///
++ /// Use instead:
+ /// ```ignore
+ /// println!("Hello World");
+ /// let foo = if … {
+ /// 13
+ /// } else {
+ /// 42
+ /// };
+ /// ```
+ #[clippy::version = "1.53.0"]
+ pub BRANCHES_SHARING_CODE,
+ nursery,
+ "`if` statement with shared code in all blocks"
+}
+
+declare_lint_pass!(CopyAndPaste => [
+ IFS_SAME_COND,
+ SAME_FUNCTIONS_IN_IF_CONDITION,
+ IF_SAME_THEN_ELSE,
+ BRANCHES_SHARING_CODE
+]);
+
+impl<'tcx> LateLintPass<'tcx> for CopyAndPaste {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if !expr.span.from_expansion() {
+ if let ExprKind::If(_, _, _) = expr.kind {
+ // skip ifs directly in else, it will be checked in the parent if
+ if let Some(&Expr {
+ kind: ExprKind::If(_, _, Some(else_expr)),
+ ..
+ }) = get_parent_expr(cx, expr)
+ {
+ if else_expr.hir_id == expr.hir_id {
+ return;
+ }
+ }
+
+ let (conds, blocks) = if_sequence(expr);
+ // Conditions
+ lint_same_cond(cx, &conds);
+ lint_same_fns_in_if_cond(cx, &conds);
+ // Block duplication
+ lint_same_then_else(cx, &conds, &blocks, conds.len() == blocks.len(), expr);
+ }
+ }
+ }
+}
+
+/// Implementation of `BRANCHES_SHARING_CODE` and `IF_SAME_THEN_ELSE` if the blocks are equal.
+fn lint_same_then_else<'tcx>(
+ cx: &LateContext<'tcx>,
+ conds: &[&'tcx Expr<'_>],
+ blocks: &[&Block<'tcx>],
+ has_conditional_else: bool,
+ expr: &'tcx Expr<'_>,
+) {
+ // We only lint ifs with multiple blocks
+ if blocks.len() < 2 || is_else_clause(cx.tcx, expr) {
+ return;
+ }
+
+ // Check if each block has shared code
+ let has_expr = blocks[0].expr.is_some();
+
+ let (start_eq, mut end_eq, expr_eq) = if let Some(block_eq) = scan_block_for_eq(cx, conds, blocks) {
+ (block_eq.start_eq, block_eq.end_eq, block_eq.expr_eq)
+ } else {
+ return;
+ };
+
+ // BRANCHES_SHARING_CODE prerequisites
+ if has_conditional_else || (start_eq == 0 && end_eq == 0 && (has_expr && !expr_eq)) {
+ return;
+ }
+
+ // Only the start is the same
+ if start_eq != 0 && end_eq == 0 && (!has_expr || !expr_eq) {
+ let block = blocks[0];
+ let start_stmts = block.stmts.split_at(start_eq).0;
+
+ let mut start_walker = UsedValueFinderVisitor::new(cx);
+ for stmt in start_stmts {
+ intravisit::walk_stmt(&mut start_walker, stmt);
+ }
+
+ emit_branches_sharing_code_lint(
+ cx,
+ start_eq,
+ 0,
+ false,
+ check_for_warn_of_moved_symbol(cx, &start_walker.def_symbols, expr),
+ blocks,
+ expr,
+ );
+ } else if end_eq != 0 || (has_expr && expr_eq) {
+ let block = blocks[blocks.len() - 1];
+ let (start_stmts, block_stmts) = block.stmts.split_at(start_eq);
+ let (block_stmts, end_stmts) = block_stmts.split_at(block_stmts.len() - end_eq);
+
+ // Scan start
+ let mut start_walker = UsedValueFinderVisitor::new(cx);
+ for stmt in start_stmts {
+ intravisit::walk_stmt(&mut start_walker, stmt);
+ }
+ let mut moved_syms = start_walker.def_symbols;
+
+ // Scan block
+ let mut block_walker = UsedValueFinderVisitor::new(cx);
+ for stmt in block_stmts {
+ intravisit::walk_stmt(&mut block_walker, stmt);
+ }
+ let mut block_defs = block_walker.defs;
+
+ // Scan moved stmts
+ let mut moved_start: Option<usize> = None;
+ let mut end_walker = UsedValueFinderVisitor::new(cx);
+ for (index, stmt) in end_stmts.iter().enumerate() {
+ intravisit::walk_stmt(&mut end_walker, stmt);
+
+ for value in &end_walker.uses {
+ // Well we can't move this and all prev statements. So reset
+ if block_defs.contains(value) {
+ moved_start = Some(index + 1);
+ end_walker.defs.drain().for_each(|x| {
+ block_defs.insert(x);
+ });
+
+ end_walker.def_symbols.clear();
+ }
+ }
+
+ end_walker.uses.clear();
+ }
+
+ if let Some(moved_start) = moved_start {
+ end_eq -= moved_start;
+ }
+
+ let end_linable = block.expr.map_or_else(
+ || end_eq != 0,
+ |expr| {
+ intravisit::walk_expr(&mut end_walker, expr);
+ end_walker.uses.iter().any(|x| !block_defs.contains(x))
+ },
+ );
+
+ if end_linable {
+ end_walker.def_symbols.drain().for_each(|x| {
+ moved_syms.insert(x);
+ });
+ }
+
+ emit_branches_sharing_code_lint(
+ cx,
+ start_eq,
+ end_eq,
+ end_linable,
+ check_for_warn_of_moved_symbol(cx, &moved_syms, expr),
+ blocks,
+ expr,
+ );
+ }
+}
+
+struct BlockEqual {
+ /// The amount statements that are equal from the start
+ start_eq: usize,
+ /// The amount statements that are equal from the end
+ end_eq: usize,
+ /// An indication if the block expressions are the same. This will also be true if both are
+ /// `None`
+ expr_eq: bool,
+}
+
+/// This function can also trigger the `IF_SAME_THEN_ELSE` in which case it'll return `None` to
+/// abort any further processing and avoid duplicate lint triggers.
+fn scan_block_for_eq(cx: &LateContext<'_>, conds: &[&Expr<'_>], blocks: &[&Block<'_>]) -> Option<BlockEqual> {
+ let mut start_eq = usize::MAX;
+ let mut end_eq = usize::MAX;
+ let mut expr_eq = true;
+ let mut iter = blocks.windows(2).enumerate();
+ while let Some((i, &[block0, block1])) = iter.next() {
+ let l_stmts = block0.stmts;
+ let r_stmts = block1.stmts;
+
+ // `SpanlessEq` now keeps track of the locals and is therefore context sensitive clippy#6752.
+ // The comparison therefore needs to be done in a way that builds the correct context.
+ let mut evaluator = SpanlessEq::new(cx);
+ let mut evaluator = evaluator.inter_expr();
+
+ let current_start_eq = count_eq(&mut l_stmts.iter(), &mut r_stmts.iter(), |l, r| evaluator.eq_stmt(l, r));
+
+ let current_end_eq = {
+ // We skip the middle statements which can't be equal
+ let end_comparison_count = l_stmts.len().min(r_stmts.len()) - current_start_eq;
+ let it1 = l_stmts.iter().skip(l_stmts.len() - end_comparison_count);
+ let it2 = r_stmts.iter().skip(r_stmts.len() - end_comparison_count);
+ it1.zip(it2)
+ .fold(0, |acc, (l, r)| if evaluator.eq_stmt(l, r) { acc + 1 } else { 0 })
+ };
+ let block_expr_eq = both(&block0.expr, &block1.expr, |l, r| evaluator.eq_expr(l, r));
+
+ // IF_SAME_THEN_ELSE
+ if_chain! {
+ if block_expr_eq;
+ if l_stmts.len() == r_stmts.len();
+ if l_stmts.len() == current_start_eq;
+ // `conds` may have one last item than `blocks`.
+ // Any `i` from `blocks.windows(2)` will exist in `conds`, but `i+1` may not exist on the last iteration.
+ if !matches!(conds[i].kind, ExprKind::Let(..));
+ if !matches!(conds.get(i + 1).map(|e| &e.kind), Some(ExprKind::Let(..)));
+ if !is_lint_allowed(cx, IF_SAME_THEN_ELSE, block0.hir_id);
+ if !is_lint_allowed(cx, IF_SAME_THEN_ELSE, block1.hir_id);
+ then {
+ span_lint_and_note(
+ cx,
+ IF_SAME_THEN_ELSE,
+ block0.span,
+ "this `if` has identical blocks",
+ Some(block1.span),
+ "same as this",
+ );
+
+ return None;
+ }
+ }
+
+ start_eq = start_eq.min(current_start_eq);
+ end_eq = end_eq.min(current_end_eq);
+ expr_eq &= block_expr_eq;
+ }
+
+ if !expr_eq {
+ end_eq = 0;
+ }
+
+ // Check if the regions are overlapping. Set `end_eq` to prevent the overlap
+ let min_block_size = blocks.iter().map(|x| x.stmts.len()).min().unwrap();
+ if (start_eq + end_eq) > min_block_size {
+ end_eq = min_block_size - start_eq;
+ }
+
+ Some(BlockEqual {
+ start_eq,
+ end_eq,
+ expr_eq,
+ })
+}
+
+fn check_for_warn_of_moved_symbol(cx: &LateContext<'_>, symbols: &FxHashSet<Symbol>, if_expr: &Expr<'_>) -> bool {
+ get_enclosing_block(cx, if_expr.hir_id).map_or(false, |block| {
+ let ignore_span = block.span.shrink_to_lo().to(if_expr.span);
+
+ symbols
+ .iter()
+ .filter(|sym| !sym.as_str().starts_with('_'))
+ .any(move |sym| {
+ let mut walker = ContainsName {
+ name: *sym,
+ result: false,
+ };
+
+ // Scan block
+ block
+ .stmts
+ .iter()
+ .filter(|stmt| !ignore_span.overlaps(stmt.span))
+ .for_each(|stmt| intravisit::walk_stmt(&mut walker, stmt));
+
+ if let Some(expr) = block.expr {
+ intravisit::walk_expr(&mut walker, expr);
+ }
+
+ walker.result
+ })
+ })
+}
+
+fn emit_branches_sharing_code_lint(
+ cx: &LateContext<'_>,
+ start_stmts: usize,
+ end_stmts: usize,
+ lint_end: bool,
+ warn_about_moved_symbol: bool,
+ blocks: &[&Block<'_>],
+ if_expr: &Expr<'_>,
+) {
+ if start_stmts == 0 && !lint_end {
+ return;
+ }
+
+ // (help, span, suggestion)
+ let mut suggestions: Vec<(&str, Span, String)> = vec![];
+ let mut add_expr_note = false;
+
+ // Construct suggestions
+ let sm = cx.sess().source_map();
+ if start_stmts > 0 {
+ let block = blocks[0];
+ let span_start = first_line_of_span(cx, if_expr.span).shrink_to_lo();
+ let span_end = sm.stmt_span(block.stmts[start_stmts - 1].span, block.span);
+
+ let cond_span = first_line_of_span(cx, if_expr.span).until(block.span);
+ let cond_snippet = reindent_multiline(snippet(cx, cond_span, "_"), false, None);
+ let cond_indent = indent_of(cx, cond_span);
+ let moved_span = block.stmts[0].span.source_callsite().to(span_end);
+ let moved_snippet = reindent_multiline(snippet(cx, moved_span, "_"), true, None);
+ let suggestion = moved_snippet.to_string() + "\n" + &cond_snippet + "{";
+ let suggestion = reindent_multiline(Cow::Borrowed(&suggestion), true, cond_indent);
+
+ let span = span_start.to(span_end);
+ suggestions.push(("start", span, suggestion.to_string()));
+ }
+
+ if lint_end {
+ let block = blocks[blocks.len() - 1];
+ let span_end = block.span.shrink_to_hi();
+
+ let moved_start = if end_stmts == 0 && block.expr.is_some() {
+ block.expr.unwrap().span.source_callsite()
+ } else {
+ sm.stmt_span(block.stmts[block.stmts.len() - end_stmts].span, block.span)
+ };
+ let moved_end = block.expr.map_or_else(
+ || sm.stmt_span(block.stmts[block.stmts.len() - 1].span, block.span),
+ |expr| expr.span.source_callsite(),
+ );
+
+ let moved_span = moved_start.to(moved_end);
+ let moved_snipped = reindent_multiline(snippet(cx, moved_span, "_"), true, None);
+ let indent = indent_of(cx, if_expr.span.shrink_to_hi());
+ let suggestion = "}\n".to_string() + &moved_snipped;
+ let suggestion = reindent_multiline(Cow::Borrowed(&suggestion), true, indent);
+
+ let mut span = moved_start.to(span_end);
+ // Improve formatting if the inner block has indention (i.e. normal Rust formatting)
+ let test_span = Span::new(span.lo() - BytePos(4), span.lo(), span.ctxt(), span.parent());
+ if snippet_opt(cx, test_span)
+ .map(|snip| snip == " ")
+ .unwrap_or_default()
+ {
+ span = span.with_lo(test_span.lo());
+ }
+
+ suggestions.push(("end", span, suggestion.to_string()));
+ add_expr_note = !cx.typeck_results().expr_ty(if_expr).is_unit();
+ }
+
+ let add_optional_msgs = |diag: &mut Diagnostic| {
+ if add_expr_note {
+ diag.note("The end suggestion probably needs some adjustments to use the expression result correctly");
+ }
+
+ if warn_about_moved_symbol {
+ diag.warn("Some moved values might need to be renamed to avoid wrong references");
+ }
+ };
+
+ // Emit lint
+ if suggestions.len() == 1 {
+ let (place_str, span, sugg) = suggestions.pop().unwrap();
+ let msg = format!("all if blocks contain the same code at the {}", place_str);
+ let help = format!("consider moving the {} statements out like this", place_str);
+ span_lint_and_then(cx, BRANCHES_SHARING_CODE, span, msg.as_str(), |diag| {
+ diag.span_suggestion(span, help.as_str(), sugg, Applicability::Unspecified);
+
+ add_optional_msgs(diag);
+ });
+ } else if suggestions.len() == 2 {
+ let (_, end_span, end_sugg) = suggestions.pop().unwrap();
+ let (_, start_span, start_sugg) = suggestions.pop().unwrap();
+ span_lint_and_then(
+ cx,
+ BRANCHES_SHARING_CODE,
+ start_span,
+ "all if blocks contain the same code at the start and the end. Here at the start",
+ move |diag| {
+ diag.span_note(end_span, "and here at the end");
+
+ diag.span_suggestion(
+ start_span,
+ "consider moving the start statements out like this",
+ start_sugg,
+ Applicability::Unspecified,
+ );
+
+ diag.span_suggestion(
+ end_span,
+ "and consider moving the end statements out like this",
+ end_sugg,
+ Applicability::Unspecified,
+ );
+
+ add_optional_msgs(diag);
+ },
+ );
+ }
+}
+
+/// This visitor collects `HirId`s and Symbols of defined symbols and `HirId`s of used values.
+struct UsedValueFinderVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+
+ /// The `HirId`s of defined values in the scanned statements
+ defs: FxHashSet<HirId>,
+
+ /// The Symbols of the defined symbols in the scanned statements
+ def_symbols: FxHashSet<Symbol>,
+
+ /// The `HirId`s of the used values
+ uses: FxHashSet<HirId>,
+}
+
+impl<'a, 'tcx> UsedValueFinderVisitor<'a, 'tcx> {
+ fn new(cx: &'a LateContext<'tcx>) -> Self {
+ UsedValueFinderVisitor {
+ cx,
+ defs: FxHashSet::default(),
+ def_symbols: FxHashSet::default(),
+ uses: FxHashSet::default(),
+ }
+ }
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for UsedValueFinderVisitor<'a, 'tcx> {
+ type NestedFilter = nested_filter::All;
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+
+ fn visit_local(&mut self, l: &'tcx rustc_hir::Local<'tcx>) {
+ let local_id = l.pat.hir_id;
+ self.defs.insert(local_id);
+
+ if let Some(sym) = l.pat.simple_ident() {
+ self.def_symbols.insert(sym.name);
+ }
+
+ if let Some(expr) = l.init {
+ intravisit::walk_expr(self, expr);
+ }
+ }
+
+ fn visit_qpath(&mut self, qpath: &'tcx rustc_hir::QPath<'tcx>, id: HirId, _span: rustc_span::Span) {
+ if let rustc_hir::QPath::Resolved(_, path) = *qpath {
+ if path.segments.len() == 1 {
+ if let rustc_hir::def::Res::Local(var) = self.cx.qpath_res(qpath, id) {
+ self.uses.insert(var);
+ }
+ }
+ }
+ }
+}
+
+/// Implementation of `IFS_SAME_COND`.
+fn lint_same_cond(cx: &LateContext<'_>, conds: &[&Expr<'_>]) {
+ let hash: &dyn Fn(&&Expr<'_>) -> u64 = &|expr| -> u64 {
+ let mut h = SpanlessHash::new(cx);
+ h.hash_expr(expr);
+ h.finish()
+ };
+
+ let eq: &dyn Fn(&&Expr<'_>, &&Expr<'_>) -> bool = &|&lhs, &rhs| -> bool { eq_expr_value(cx, lhs, rhs) };
+
+ for (i, j) in search_same(conds, hash, eq) {
+ span_lint_and_note(
+ cx,
+ IFS_SAME_COND,
+ j.span,
+ "this `if` has the same condition as a previous `if`",
+ Some(i.span),
+ "same as this",
+ );
+ }
+}
+
+/// Implementation of `SAME_FUNCTIONS_IN_IF_CONDITION`.
+fn lint_same_fns_in_if_cond(cx: &LateContext<'_>, conds: &[&Expr<'_>]) {
+ let hash: &dyn Fn(&&Expr<'_>) -> u64 = &|expr| -> u64 {
+ let mut h = SpanlessHash::new(cx);
+ h.hash_expr(expr);
+ h.finish()
+ };
+
+ let eq: &dyn Fn(&&Expr<'_>, &&Expr<'_>) -> bool = &|&lhs, &rhs| -> bool {
+ // Do not lint if any expr originates from a macro
+ if lhs.span.from_expansion() || rhs.span.from_expansion() {
+ return false;
+ }
+ // Do not spawn warning if `IFS_SAME_COND` already produced it.
+ if eq_expr_value(cx, lhs, rhs) {
+ return false;
+ }
+ SpanlessEq::new(cx).eq_expr(lhs, rhs)
+ };
+
+ for (i, j) in search_same(conds, hash, eq) {
+ span_lint_and_note(
+ cx,
+ SAME_FUNCTIONS_IN_IF_CONDITION,
+ j.span,
+ "this `if` has the same function call as a previous `if`",
+ Some(i.span),
+ "same as this",
+ );
+ }
+}
--- /dev/null
- if let Some(span) = is_crate_keyword(&curr);
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use rustc_ast::ast::{AttrKind, Attribute, Item, ItemKind};
+use rustc_ast::token::{Token, TokenKind};
+use rustc_ast::tokenstream::{TokenStream, TokenTree};
+use rustc_errors::Applicability;
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::{symbol::sym, Span};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for use of `crate` as opposed to `$crate` in a macro definition.
+ ///
+ /// ### Why is this bad?
+ /// `crate` refers to the macro call's crate, whereas `$crate` refers to the macro definition's
+ /// crate. Rarely is the former intended. See:
+ /// https://doc.rust-lang.org/reference/macros-by-example.html#hygiene
+ ///
+ /// ### Example
+ /// ```rust
+ /// #[macro_export]
+ /// macro_rules! print_message {
+ /// () => {
+ /// println!("{}", crate::MESSAGE);
+ /// };
+ /// }
+ /// pub const MESSAGE: &str = "Hello!";
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// #[macro_export]
+ /// macro_rules! print_message {
+ /// () => {
+ /// println!("{}", $crate::MESSAGE);
+ /// };
+ /// }
+ /// pub const MESSAGE: &str = "Hello!";
+ /// ```
+ ///
+ /// Note that if the use of `crate` is intentional, an `allow` attribute can be applied to the
+ /// macro definition, e.g.:
+ /// ```rust,ignore
+ /// #[allow(clippy::crate_in_macro_def)]
+ /// macro_rules! ok { ... crate::foo ... }
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub CRATE_IN_MACRO_DEF,
+ suspicious,
+ "using `crate` in a macro definition"
+}
+declare_lint_pass!(CrateInMacroDef => [CRATE_IN_MACRO_DEF]);
+
+impl EarlyLintPass for CrateInMacroDef {
+ fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
+ if_chain! {
+ if item.attrs.iter().any(is_macro_export);
+ if let ItemKind::MacroDef(macro_def) = &item.kind;
+ let tts = macro_def.body.inner_tokens();
+ if let Some(span) = contains_unhygienic_crate_reference(&tts);
+ then {
+ span_lint_and_sugg(
+ cx,
+ CRATE_IN_MACRO_DEF,
+ span,
+ "`crate` references the macro call's crate",
+ "to reference the macro definition's crate, use",
+ String::from("$crate"),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ }
+}
+
+fn is_macro_export(attr: &Attribute) -> bool {
+ if_chain! {
+ if let AttrKind::Normal(attr_item, _) = &attr.kind;
+ if let [segment] = attr_item.path.segments.as_slice();
+ then {
+ segment.ident.name == sym::macro_export
+ } else {
+ false
+ }
+ }
+}
+
+fn contains_unhygienic_crate_reference(tts: &TokenStream) -> Option<Span> {
+ let mut prev_is_dollar = false;
+ let mut cursor = tts.trees();
+ while let Some(curr) = cursor.next() {
+ if_chain! {
+ if !prev_is_dollar;
- prev_is_dollar = is_token(&curr, &TokenKind::Dollar);
++ if let Some(span) = is_crate_keyword(curr);
+ if let Some(next) = cursor.look_ahead(0);
+ if is_token(next, &TokenKind::ModSep);
+ then {
+ return Some(span);
+ }
+ }
+ if let TokenTree::Delimited(_, _, tts) = &curr {
+ let span = contains_unhygienic_crate_reference(tts);
+ if span.is_some() {
+ return span;
+ }
+ }
++ prev_is_dollar = is_token(curr, &TokenKind::Dollar);
+ }
+ None
+}
+
+fn is_crate_keyword(tt: &TokenTree) -> Option<Span> {
+ if_chain! {
+ if let TokenTree::Token(Token { kind: TokenKind::Ident(symbol, _), span }) = tt;
+ if symbol.as_str() == "crate";
+ then { Some(*span) } else { None }
+ }
+}
+
+fn is_token(tt: &TokenTree, kind: &TokenKind) -> bool {
+ if let TokenTree::Token(Token { kind: other, .. }) = tt {
+ kind == other
+ } else {
+ false
+ }
+}
--- /dev/null
- use rustc_session::{declare_lint_pass, declare_tool_lint};
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::macros::root_macro_call_first_node;
+use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::{is_in_cfg_test, is_in_test_function};
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
- declare_lint_pass!(DbgMacro => [DBG_MACRO]);
++use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of dbg!() macro.
+ ///
+ /// ### Why is this bad?
+ /// `dbg!` macro is intended as a debugging tool. It
+ /// should not be in version control.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// // Bad
+ /// dbg!(true)
+ ///
+ /// // Good
+ /// true
+ /// ```
+ #[clippy::version = "1.34.0"]
+ pub DBG_MACRO,
+ restriction,
+ "`dbg!` macro is intended as a debugging tool"
+}
+
- // we make an exception for test code
- if is_in_test_function(cx.tcx, expr.hir_id) || is_in_cfg_test(cx.tcx, expr.hir_id) {
++#[derive(Copy, Clone)]
++pub struct DbgMacro {
++ allow_dbg_in_tests: bool,
++}
++
++impl_lint_pass!(DbgMacro => [DBG_MACRO]);
++
++impl DbgMacro {
++ pub fn new(allow_dbg_in_tests: bool) -> Self {
++ DbgMacro { allow_dbg_in_tests }
++ }
++}
+
+impl LateLintPass<'_> for DbgMacro {
+ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
+ let Some(macro_call) = root_macro_call_first_node(cx, expr) else { return };
+ if cx.tcx.is_diagnostic_item(sym::dbg_macro, macro_call.def_id) {
++ // allows `dbg!` in test code if allow-dbg-in-test is set to true in clippy.toml
++ if self.allow_dbg_in_tests
++ && (is_in_test_function(cx.tcx, expr.hir_id) || is_in_cfg_test(cx.tcx, expr.hir_id))
++ {
+ return;
+ }
+ let mut applicability = Applicability::MachineApplicable;
+ let suggestion = match expr.peel_drop_temps().kind {
+ // dbg!()
+ ExprKind::Block(_, _) => String::new(),
+ // dbg!(1)
+ ExprKind::Match(val, ..) => {
+ snippet_with_applicability(cx, val.span.source_callsite(), "..", &mut applicability).to_string()
+ },
+ // dbg!(2, 3)
+ ExprKind::Tup(
+ [
+ Expr {
+ kind: ExprKind::Match(first, ..),
+ ..
+ },
+ ..,
+ Expr {
+ kind: ExprKind::Match(last, ..),
+ ..
+ },
+ ],
+ ) => {
+ let snippet = snippet_with_applicability(
+ cx,
+ first.span.source_callsite().to(last.span.source_callsite()),
+ "..",
+ &mut applicability,
+ );
+ format!("({snippet})")
+ },
+ _ => return,
+ };
+
+ span_lint_and_sugg(
+ cx,
+ DBG_MACRO,
+ macro_call.span,
+ "`dbg!` macro is intended as a debugging tool",
+ "ensure to avoid having uses of it in version control",
+ suggestion,
+ applicability,
+ );
+ }
+ }
+}
--- /dev/null
- /// impl std::default::Default for Foo {
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::{is_default_equivalent, peel_blocks};
+use rustc_hir::{
+ def::{DefKind, Res},
+ Body, Expr, ExprKind, GenericArg, Impl, ImplItemKind, Item, ItemKind, Node, PathSegment, QPath, TyKind,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Detects manual `std::default::Default` implementations that are identical to a derived implementation.
+ ///
+ /// ### Why is this bad?
+ /// It is less concise.
+ ///
+ /// ### Example
+ /// ```rust
+ /// struct Foo {
+ /// bar: bool
+ /// }
+ ///
++ /// impl Default for Foo {
+ /// fn default() -> Self {
+ /// Self {
+ /// bar: false
+ /// }
+ /// }
+ /// }
+ /// ```
+ ///
+ /// Could be written as:
+ ///
+ /// ```rust
+ /// #[derive(Default)]
+ /// struct Foo {
+ /// bar: bool
+ /// }
+ /// ```
+ ///
+ /// ### Known problems
+ /// Derive macros [sometimes use incorrect bounds](https://github.com/rust-lang/rust/issues/26925)
+ /// in generic types and the user defined `impl` maybe is more generalized or
+ /// specialized than what derive will produce. This lint can't detect the manual `impl`
+ /// has exactly equal bounds, and therefore this lint is disabled for types with
+ /// generic parameters.
+ ///
+ #[clippy::version = "1.57.0"]
+ pub DERIVABLE_IMPLS,
+ complexity,
+ "manual implementation of the `Default` trait which is equal to a derive"
+}
+
+declare_lint_pass!(DerivableImpls => [DERIVABLE_IMPLS]);
+
+fn is_path_self(e: &Expr<'_>) -> bool {
+ if let ExprKind::Path(QPath::Resolved(_, p)) = e.kind {
+ matches!(p.res, Res::SelfCtor(..) | Res::Def(DefKind::Ctor(..), _))
+ } else {
+ false
+ }
+}
+
+impl<'tcx> LateLintPass<'tcx> for DerivableImpls {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
+ if_chain! {
+ if let ItemKind::Impl(Impl {
+ of_trait: Some(ref trait_ref),
+ items: [child],
+ self_ty,
+ ..
+ }) = item.kind;
+ if !cx.tcx.has_attr(item.def_id.to_def_id(), sym::automatically_derived);
+ if !item.span.from_expansion();
+ if let Some(def_id) = trait_ref.trait_def_id();
+ if cx.tcx.is_diagnostic_item(sym::Default, def_id);
+ if let impl_item_hir = child.id.hir_id();
+ if let Some(Node::ImplItem(impl_item)) = cx.tcx.hir().find(impl_item_hir);
+ if let ImplItemKind::Fn(_, b) = &impl_item.kind;
+ if let Body { value: func_expr, .. } = cx.tcx.hir().body(*b);
+ if let Some(adt_def) = cx.tcx.type_of(item.def_id).ty_adt_def();
+ if let attrs = cx.tcx.hir().attrs(item.hir_id());
+ if !attrs.iter().any(|attr| attr.doc_str().is_some());
+ if let child_attrs = cx.tcx.hir().attrs(impl_item_hir);
+ if !child_attrs.iter().any(|attr| attr.doc_str().is_some());
+ if adt_def.is_struct();
+ then {
+ if let TyKind::Path(QPath::Resolved(_, p)) = self_ty.kind {
+ if let Some(PathSegment { args: Some(a), .. }) = p.segments.last() {
+ for arg in a.args {
+ if !matches!(arg, GenericArg::Lifetime(_)) {
+ return;
+ }
+ }
+ }
+ }
+ let should_emit = match peel_blocks(func_expr).kind {
+ ExprKind::Tup(fields) => fields.iter().all(|e| is_default_equivalent(cx, e)),
+ ExprKind::Call(callee, args)
+ if is_path_self(callee) => args.iter().all(|e| is_default_equivalent(cx, e)),
+ ExprKind::Struct(_, fields, _) => fields.iter().all(|ef| is_default_equivalent(cx, ef.expr)),
+ _ => false,
+ };
+ if should_emit {
+ let path_string = cx.tcx.def_path_str(adt_def.did());
+ span_lint_and_help(
+ cx,
+ DERIVABLE_IMPLS,
+ item.span,
+ "this `impl` can be derived",
+ None,
+ &format!("try annotating `{}` with `#[derive(Default)]`", path_string),
+ );
+ }
+ }
+ }
+ }
+}
--- /dev/null
- use clippy_utils::ty::{implements_trait, is_copy};
+use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::paths;
- BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, HirId, Impl, Item, ItemKind, TraitRef, UnsafeSource, Unsafety,
++use clippy_utils::ty::{implements_trait, implements_trait_with_env, is_copy};
+use clippy_utils::{is_lint_allowed, match_def_path};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::{walk_expr, walk_fn, walk_item, FnKind, Visitor};
+use rustc_hir::{
- use rustc_middle::ty::{self, Ty};
++ self as hir, BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, HirId, Impl, Item, ItemKind, UnsafeSource, Unsafety,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::nested_filter;
- trait_ref: &TraitRef<'_>,
++use rustc_middle::ty::subst::GenericArg;
++use rustc_middle::ty::{self, BoundConstness, ImplPolarity, ParamEnv, PredicateKind, TraitPredicate, TraitRef, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for deriving `Hash` but implementing `PartialEq`
+ /// explicitly or vice versa.
+ ///
+ /// ### Why is this bad?
+ /// The implementation of these traits must agree (for
+ /// example for use with `HashMap`) so it’s probably a bad idea to use a
+ /// default-generated `Hash` implementation with an explicitly defined
+ /// `PartialEq`. In particular, the following must hold for any type:
+ ///
+ /// ```text
+ /// k1 == k2 ⇒ hash(k1) == hash(k2)
+ /// ```
+ ///
+ /// ### Example
+ /// ```ignore
+ /// #[derive(Hash)]
+ /// struct Foo;
+ ///
+ /// impl PartialEq for Foo {
+ /// ...
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DERIVE_HASH_XOR_EQ,
+ correctness,
+ "deriving `Hash` but implementing `PartialEq` explicitly"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for deriving `Ord` but implementing `PartialOrd`
+ /// explicitly or vice versa.
+ ///
+ /// ### Why is this bad?
+ /// The implementation of these traits must agree (for
+ /// example for use with `sort`) so it’s probably a bad idea to use a
+ /// default-generated `Ord` implementation with an explicitly defined
+ /// `PartialOrd`. In particular, the following must hold for any type
+ /// implementing `Ord`:
+ ///
+ /// ```text
+ /// k1.cmp(&k2) == k1.partial_cmp(&k2).unwrap()
+ /// ```
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// #[derive(Ord, PartialEq, Eq)]
+ /// struct Foo;
+ ///
+ /// impl PartialOrd for Foo {
+ /// ...
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust,ignore
+ /// #[derive(PartialEq, Eq)]
+ /// struct Foo;
+ ///
+ /// impl PartialOrd for Foo {
+ /// fn partial_cmp(&self, other: &Foo) -> Option<Ordering> {
+ /// Some(self.cmp(other))
+ /// }
+ /// }
+ ///
+ /// impl Ord for Foo {
+ /// ...
+ /// }
+ /// ```
+ /// or, if you don't need a custom ordering:
+ /// ```rust,ignore
+ /// #[derive(Ord, PartialOrd, PartialEq, Eq)]
+ /// struct Foo;
+ /// ```
+ #[clippy::version = "1.47.0"]
+ pub DERIVE_ORD_XOR_PARTIAL_ORD,
+ correctness,
+ "deriving `Ord` but implementing `PartialOrd` explicitly"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for explicit `Clone` implementations for `Copy`
+ /// types.
+ ///
+ /// ### Why is this bad?
+ /// To avoid surprising behavior, these traits should
+ /// agree and the behavior of `Copy` cannot be overridden. In almost all
+ /// situations a `Copy` type should have a `Clone` implementation that does
+ /// nothing more than copy the object, which is what `#[derive(Copy, Clone)]`
+ /// gets you.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// #[derive(Copy)]
+ /// struct Foo;
+ ///
+ /// impl Clone for Foo {
+ /// // ..
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EXPL_IMPL_CLONE_ON_COPY,
+ pedantic,
+ "implementing `Clone` explicitly on `Copy` types"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for deriving `serde::Deserialize` on a type that
+ /// has methods using `unsafe`.
+ ///
+ /// ### Why is this bad?
+ /// Deriving `serde::Deserialize` will create a constructor
+ /// that may violate invariants hold by another constructor.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// use serde::Deserialize;
+ ///
+ /// #[derive(Deserialize)]
+ /// pub struct Foo {
+ /// // ..
+ /// }
+ ///
+ /// impl Foo {
+ /// pub fn new() -> Self {
+ /// // setup here ..
+ /// }
+ ///
+ /// pub unsafe fn parts() -> (&str, &str) {
+ /// // assumes invariants hold
+ /// }
+ /// }
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub UNSAFE_DERIVE_DESERIALIZE,
+ pedantic,
+ "deriving `serde::Deserialize` on a type that has methods using `unsafe`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for types that derive `PartialEq` and could implement `Eq`.
+ ///
+ /// ### Why is this bad?
+ /// If a type `T` derives `PartialEq` and all of its members implement `Eq`,
+ /// then `T` can always implement `Eq`. Implementing `Eq` allows `T` to be used
+ /// in APIs that require `Eq` types. It also allows structs containing `T` to derive
+ /// `Eq` themselves.
+ ///
+ /// ### Example
+ /// ```rust
+ /// #[derive(PartialEq)]
+ /// struct Foo {
+ /// i_am_eq: i32,
+ /// i_am_eq_too: Vec<String>,
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// #[derive(PartialEq, Eq)]
+ /// struct Foo {
+ /// i_am_eq: i32,
+ /// i_am_eq_too: Vec<String>,
+ /// }
+ /// ```
+ #[clippy::version = "1.62.0"]
+ pub DERIVE_PARTIAL_EQ_WITHOUT_EQ,
+ style,
+ "deriving `PartialEq` on a type that can implement `Eq`, without implementing `Eq`"
+}
+
+declare_lint_pass!(Derive => [
+ EXPL_IMPL_CLONE_ON_COPY,
+ DERIVE_HASH_XOR_EQ,
+ DERIVE_ORD_XOR_PARTIAL_ORD,
+ UNSAFE_DERIVE_DESERIALIZE,
+ DERIVE_PARTIAL_EQ_WITHOUT_EQ
+]);
+
+impl<'tcx> LateLintPass<'tcx> for Derive {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
+ if let ItemKind::Impl(Impl {
+ of_trait: Some(ref trait_ref),
+ ..
+ }) = item.kind
+ {
+ let ty = cx.tcx.type_of(item.def_id);
+ let is_automatically_derived = cx.tcx.has_attr(item.def_id.to_def_id(), sym::automatically_derived);
+
+ check_hash_peq(cx, item.span, trait_ref, ty, is_automatically_derived);
+ check_ord_partial_ord(cx, item.span, trait_ref, ty, is_automatically_derived);
+
+ if is_automatically_derived {
+ check_unsafe_derive_deserialize(cx, item, trait_ref, ty);
+ check_partial_eq_without_eq(cx, item.span, trait_ref, ty);
+ } else {
+ check_copy_clone(cx, item, trait_ref, ty);
+ }
+ }
+ }
+}
+
+/// Implementation of the `DERIVE_HASH_XOR_EQ` lint.
+fn check_hash_peq<'tcx>(
+ cx: &LateContext<'tcx>,
+ span: Span,
- trait_ref: &TraitRef<'_>,
++ trait_ref: &hir::TraitRef<'_>,
+ ty: Ty<'tcx>,
+ hash_is_automatically_derived: bool,
+) {
+ if_chain! {
+ if let Some(peq_trait_def_id) = cx.tcx.lang_items().eq_trait();
+ if let Some(def_id) = trait_ref.trait_def_id();
+ if cx.tcx.is_diagnostic_item(sym::Hash, def_id);
+ then {
+ // Look for the PartialEq implementations for `ty`
+ cx.tcx.for_each_relevant_impl(peq_trait_def_id, ty, |impl_id| {
+ let peq_is_automatically_derived = cx.tcx.has_attr(impl_id, sym::automatically_derived);
+
+ if peq_is_automatically_derived == hash_is_automatically_derived {
+ return;
+ }
+
+ let trait_ref = cx.tcx.impl_trait_ref(impl_id).expect("must be a trait implementation");
+
+ // Only care about `impl PartialEq<Foo> for Foo`
+ // For `impl PartialEq<B> for A, input_types is [A, B]
+ if trait_ref.substs.type_at(1) == ty {
+ let mess = if peq_is_automatically_derived {
+ "you are implementing `Hash` explicitly but have derived `PartialEq`"
+ } else {
+ "you are deriving `Hash` but have implemented `PartialEq` explicitly"
+ };
+
+ span_lint_and_then(
+ cx,
+ DERIVE_HASH_XOR_EQ,
+ span,
+ mess,
+ |diag| {
+ if let Some(local_def_id) = impl_id.as_local() {
+ let hir_id = cx.tcx.hir().local_def_id_to_hir_id(local_def_id);
+ diag.span_note(
+ cx.tcx.hir().span(hir_id),
+ "`PartialEq` implemented here"
+ );
+ }
+ }
+ );
+ }
+ });
+ }
+ }
+}
+
+/// Implementation of the `DERIVE_ORD_XOR_PARTIAL_ORD` lint.
+fn check_ord_partial_ord<'tcx>(
+ cx: &LateContext<'tcx>,
+ span: Span,
- fn check_copy_clone<'tcx>(cx: &LateContext<'tcx>, item: &Item<'_>, trait_ref: &TraitRef<'_>, ty: Ty<'tcx>) {
++ trait_ref: &hir::TraitRef<'_>,
+ ty: Ty<'tcx>,
+ ord_is_automatically_derived: bool,
+) {
+ if_chain! {
+ if let Some(ord_trait_def_id) = cx.tcx.get_diagnostic_item(sym::Ord);
+ if let Some(partial_ord_trait_def_id) = cx.tcx.lang_items().partial_ord_trait();
+ if let Some(def_id) = &trait_ref.trait_def_id();
+ if *def_id == ord_trait_def_id;
+ then {
+ // Look for the PartialOrd implementations for `ty`
+ cx.tcx.for_each_relevant_impl(partial_ord_trait_def_id, ty, |impl_id| {
+ let partial_ord_is_automatically_derived = cx.tcx.has_attr(impl_id, sym::automatically_derived);
+
+ if partial_ord_is_automatically_derived == ord_is_automatically_derived {
+ return;
+ }
+
+ let trait_ref = cx.tcx.impl_trait_ref(impl_id).expect("must be a trait implementation");
+
+ // Only care about `impl PartialOrd<Foo> for Foo`
+ // For `impl PartialOrd<B> for A, input_types is [A, B]
+ if trait_ref.substs.type_at(1) == ty {
+ let mess = if partial_ord_is_automatically_derived {
+ "you are implementing `Ord` explicitly but have derived `PartialOrd`"
+ } else {
+ "you are deriving `Ord` but have implemented `PartialOrd` explicitly"
+ };
+
+ span_lint_and_then(
+ cx,
+ DERIVE_ORD_XOR_PARTIAL_ORD,
+ span,
+ mess,
+ |diag| {
+ if let Some(local_def_id) = impl_id.as_local() {
+ let hir_id = cx.tcx.hir().local_def_id_to_hir_id(local_def_id);
+ diag.span_note(
+ cx.tcx.hir().span(hir_id),
+ "`PartialOrd` implemented here"
+ );
+ }
+ }
+ );
+ }
+ });
+ }
+ }
+}
+
+/// Implementation of the `EXPL_IMPL_CLONE_ON_COPY` lint.
- trait_ref: &TraitRef<'_>,
++fn check_copy_clone<'tcx>(cx: &LateContext<'tcx>, item: &Item<'_>, trait_ref: &hir::TraitRef<'_>, ty: Ty<'tcx>) {
+ let clone_id = match cx.tcx.lang_items().clone_trait() {
+ Some(id) if trait_ref.trait_def_id() == Some(id) => id,
+ _ => return,
+ };
+ let copy_id = match cx.tcx.lang_items().copy_trait() {
+ Some(id) => id,
+ None => return,
+ };
+ let (ty_adt, ty_subs) = match *ty.kind() {
+ // Unions can't derive clone.
+ ty::Adt(adt, subs) if !adt.is_union() => (adt, subs),
+ _ => return,
+ };
+ // If the current self type doesn't implement Copy (due to generic constraints), search to see if
+ // there's a Copy impl for any instance of the adt.
+ if !is_copy(cx, ty) {
+ if ty_subs.non_erasable_generics().next().is_some() {
+ let has_copy_impl = cx.tcx.all_local_trait_impls(()).get(©_id).map_or(false, |impls| {
+ impls
+ .iter()
+ .any(|&id| matches!(cx.tcx.type_of(id).kind(), ty::Adt(adt, _) if ty_adt.did() == adt.did()))
+ });
+ if !has_copy_impl {
+ return;
+ }
+ } else {
+ return;
+ }
+ }
+ // Derive constrains all generic types to requiring Clone. Check if any type is not constrained for
+ // this impl.
+ if ty_subs.types().any(|ty| !implements_trait(cx, ty, clone_id, &[])) {
+ return;
+ }
+
+ span_lint_and_note(
+ cx,
+ EXPL_IMPL_CLONE_ON_COPY,
+ item.span,
+ "you are implementing `Clone` explicitly on a `Copy` type",
+ Some(item.span),
+ "consider deriving `Clone` or removing `Copy`",
+ );
+}
+
+/// Implementation of the `UNSAFE_DERIVE_DESERIALIZE` lint.
+fn check_unsafe_derive_deserialize<'tcx>(
+ cx: &LateContext<'tcx>,
+ item: &Item<'_>,
- fn check_partial_eq_without_eq<'tcx>(cx: &LateContext<'tcx>, span: Span, trait_ref: &TraitRef<'_>, ty: Ty<'tcx>) {
++ trait_ref: &hir::TraitRef<'_>,
+ ty: Ty<'tcx>,
+) {
+ fn has_unsafe<'tcx>(cx: &LateContext<'tcx>, item: &'tcx Item<'_>) -> bool {
+ let mut visitor = UnsafeVisitor { cx, has_unsafe: false };
+ walk_item(&mut visitor, item);
+ visitor.has_unsafe
+ }
+
+ if_chain! {
+ if let Some(trait_def_id) = trait_ref.trait_def_id();
+ if match_def_path(cx, trait_def_id, &paths::SERDE_DESERIALIZE);
+ if let ty::Adt(def, _) = ty.kind();
+ if let Some(local_def_id) = def.did().as_local();
+ let adt_hir_id = cx.tcx.hir().local_def_id_to_hir_id(local_def_id);
+ if !is_lint_allowed(cx, UNSAFE_DERIVE_DESERIALIZE, adt_hir_id);
+ if cx.tcx.inherent_impls(def.did())
+ .iter()
+ .map(|imp_did| cx.tcx.hir().expect_item(imp_did.expect_local()))
+ .any(|imp| has_unsafe(cx, imp));
+ then {
+ span_lint_and_help(
+ cx,
+ UNSAFE_DERIVE_DESERIALIZE,
+ item.span,
+ "you are deriving `serde::Deserialize` on a type that has methods using `unsafe`",
+ None,
+ "consider implementing `serde::Deserialize` manually. See https://serde.rs/impl-deserialize.html"
+ );
+ }
+ }
+}
+
+struct UnsafeVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ has_unsafe: bool,
+}
+
+impl<'tcx> Visitor<'tcx> for UnsafeVisitor<'_, 'tcx> {
+ type NestedFilter = nested_filter::All;
+
+ fn visit_fn(&mut self, kind: FnKind<'tcx>, decl: &'tcx FnDecl<'_>, body_id: BodyId, span: Span, id: HirId) {
+ if self.has_unsafe {
+ return;
+ }
+
+ if_chain! {
+ if let Some(header) = kind.header();
+ if header.unsafety == Unsafety::Unsafe;
+ then {
+ self.has_unsafe = true;
+ }
+ }
+
+ walk_fn(self, kind, decl, body_id, span, id);
+ }
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if self.has_unsafe {
+ return;
+ }
+
+ if let ExprKind::Block(block, _) = expr.kind {
+ if block.rules == BlockCheckMode::UnsafeBlock(UnsafeSource::UserProvided) {
+ self.has_unsafe = true;
+ }
+ }
+
+ walk_expr(self, expr);
+ }
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+}
+
+/// Implementation of the `DERIVE_PARTIAL_EQ_WITHOUT_EQ` lint.
- if !implements_trait(cx, ty, eq_trait_def_id, substs);
++fn check_partial_eq_without_eq<'tcx>(cx: &LateContext<'tcx>, span: Span, trait_ref: &hir::TraitRef<'_>, ty: Ty<'tcx>) {
+ if_chain! {
+ if let ty::Adt(adt, substs) = ty.kind();
+ if let Some(eq_trait_def_id) = cx.tcx.get_diagnostic_item(sym::Eq);
++ if let Some(peq_trait_def_id) = cx.tcx.get_diagnostic_item(sym::PartialEq);
+ if let Some(def_id) = trait_ref.trait_def_id();
+ if cx.tcx.is_diagnostic_item(sym::PartialEq, def_id);
++ // New `ParamEnv` replacing `T: PartialEq` with `T: Eq`
++ let param_env = ParamEnv::new(
++ cx.tcx.mk_predicates(cx.param_env.caller_bounds().iter().map(|p| {
++ let kind = p.kind();
++ match kind.skip_binder() {
++ PredicateKind::Trait(p)
++ if p.trait_ref.def_id == peq_trait_def_id
++ && p.trait_ref.substs.get(0) == p.trait_ref.substs.get(1)
++ && matches!(p.trait_ref.self_ty().kind(), ty::Param(_))
++ && p.constness == BoundConstness::NotConst
++ && p.polarity == ImplPolarity::Positive =>
++ {
++ cx.tcx.mk_predicate(kind.rebind(PredicateKind::Trait(TraitPredicate {
++ trait_ref: TraitRef::new(
++ eq_trait_def_id,
++ cx.tcx.mk_substs([GenericArg::from(p.trait_ref.self_ty())].into_iter()),
++ ),
++ constness: BoundConstness::NotConst,
++ polarity: ImplPolarity::Positive,
++ })))
++ },
++ _ => p,
++ }
++ })),
++ cx.param_env.reveal(),
++ cx.param_env.constness(),
++ );
++ if !implements_trait_with_env(cx.tcx, param_env, ty, eq_trait_def_id, substs);
+ then {
+ // If all of our fields implement `Eq`, we can implement `Eq` too
+ for variant in adt.variants() {
+ for field in &variant.fields {
+ let ty = field.ty(cx.tcx, substs);
+
+ if !implements_trait(cx, ty, eq_trait_def_id, substs) {
+ return;
+ }
+ }
+ }
+
+ span_lint_and_sugg(
+ cx,
+ DERIVE_PARTIAL_EQ_WITHOUT_EQ,
+ span.ctxt().outer_expn_data().call_site,
+ "you are deriving `PartialEq` and can implement `Eq`",
+ "consider deriving `Eq` as well",
+ "PartialEq, Eq".to_string(),
+ Applicability::MachineApplicable,
+ )
+ }
+ }
+}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint;
++use itertools::Itertools;
++use rustc_ast::{AttrKind, Attribute};
++use rustc_lint::{EarlyContext, EarlyLintPass};
++use rustc_session::{declare_lint_pass, declare_tool_lint};
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Detects the syntax `['foo']` in documentation comments (notice quotes instead of backticks)
++ /// outside of code blocks
++ /// ### Why is this bad?
++ /// It is likely a typo when defining an intra-doc link
++ ///
++ /// ### Example
++ /// ```rust
++ /// /// See also: ['foo']
++ /// fn bar() {}
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// /// See also: [`foo`]
++ /// fn bar() {}
++ /// ```
++ #[clippy::version = "1.60.0"]
++ pub DOC_LINK_WITH_QUOTES,
++ pedantic,
++ "possible typo for an intra-doc link"
++}
++declare_lint_pass!(DocLinkWithQuotes => [DOC_LINK_WITH_QUOTES]);
++
++impl EarlyLintPass for DocLinkWithQuotes {
++ fn check_attribute(&mut self, ctx: &EarlyContext<'_>, attr: &Attribute) {
++ if let AttrKind::DocComment(_, symbol) = attr.kind {
++ if contains_quote_link(symbol.as_str()) {
++ span_lint(
++ ctx,
++ DOC_LINK_WITH_QUOTES,
++ attr.span,
++ "possible intra-doc link using quotes instead of backticks",
++ );
++ }
++ }
++ }
++}
++
++fn contains_quote_link(s: &str) -> bool {
++ let mut in_backticks = false;
++ let mut found_opening = false;
++
++ for c in s.chars().tuple_windows::<(char, char)>() {
++ match c {
++ ('`', _) => in_backticks = !in_backticks,
++ ('[', '\'') if !in_backticks => found_opening = true,
++ ('\'', ']') if !in_backticks && found_opening => return true,
++ _ => {},
++ }
++ }
++
++ false
++}
--- /dev/null
- /// Could be written as:
+//! Lint on unnecessary double comparisons. Some examples:
+
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::eq_expr_value;
+use clippy_utils::source::snippet_with_applicability;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for double comparisons that could be simplified to a single expression.
+ ///
+ ///
+ /// ### Why is this bad?
+ /// Readability.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let x = 1;
+ /// # let y = 2;
+ /// if x == y || x < y {}
+ /// ```
+ ///
++ /// Use instead:
+ ///
+ /// ```rust
+ /// # let x = 1;
+ /// # let y = 2;
+ /// if x <= y {}
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DOUBLE_COMPARISONS,
+ complexity,
+ "unnecessary double comparisons that can be simplified"
+}
+
+declare_lint_pass!(DoubleComparisons => [DOUBLE_COMPARISONS]);
+
+impl<'tcx> DoubleComparisons {
+ #[expect(clippy::similar_names)]
+ fn check_binop(cx: &LateContext<'tcx>, op: BinOpKind, lhs: &'tcx Expr<'_>, rhs: &'tcx Expr<'_>, span: Span) {
+ let (lkind, llhs, lrhs, rkind, rlhs, rrhs) = match (&lhs.kind, &rhs.kind) {
+ (ExprKind::Binary(lb, llhs, lrhs), ExprKind::Binary(rb, rlhs, rrhs)) => {
+ (lb.node, llhs, lrhs, rb.node, rlhs, rrhs)
+ },
+ _ => return,
+ };
+ if !(eq_expr_value(cx, llhs, rlhs) && eq_expr_value(cx, lrhs, rrhs)) {
+ return;
+ }
+ macro_rules! lint_double_comparison {
+ ($op:tt) => {{
+ let mut applicability = Applicability::MachineApplicable;
+ let lhs_str = snippet_with_applicability(cx, llhs.span, "", &mut applicability);
+ let rhs_str = snippet_with_applicability(cx, lrhs.span, "", &mut applicability);
+ let sugg = format!("{} {} {}", lhs_str, stringify!($op), rhs_str);
+ span_lint_and_sugg(
+ cx,
+ DOUBLE_COMPARISONS,
+ span,
+ "this binary expression can be simplified",
+ "try",
+ sugg,
+ applicability,
+ );
+ }};
+ }
+ #[rustfmt::skip]
+ match (op, lkind, rkind) {
+ (BinOpKind::Or, BinOpKind::Eq, BinOpKind::Lt) | (BinOpKind::Or, BinOpKind::Lt, BinOpKind::Eq) => {
+ lint_double_comparison!(<=);
+ },
+ (BinOpKind::Or, BinOpKind::Eq, BinOpKind::Gt) | (BinOpKind::Or, BinOpKind::Gt, BinOpKind::Eq) => {
+ lint_double_comparison!(>=);
+ },
+ (BinOpKind::Or, BinOpKind::Lt, BinOpKind::Gt) | (BinOpKind::Or, BinOpKind::Gt, BinOpKind::Lt) => {
+ lint_double_comparison!(!=);
+ },
+ (BinOpKind::And, BinOpKind::Le, BinOpKind::Ge) | (BinOpKind::And, BinOpKind::Ge, BinOpKind::Le) => {
+ lint_double_comparison!(==);
+ },
+ _ => (),
+ };
+ }
+}
+
+impl<'tcx> LateLintPass<'tcx> for DoubleComparisons {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if let ExprKind::Binary(ref kind, lhs, rhs) = expr.kind {
+ Self::check_binop(cx, kind.node, lhs, rhs, expr.span);
+ }
+ }
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::span_lint;
+use rustc_ast::ast::{Expr, ExprKind};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for unnecessary double parentheses.
+ ///
+ /// ### Why is this bad?
+ /// This makes code harder to read and might indicate a
+ /// mistake.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// fn simple_double_parens() -> i32 {
+ /// ((0))
+ /// }
+ ///
- /// // or
- ///
++ /// # fn foo(bar: usize) {}
++ /// foo((0));
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
+ /// fn simple_no_parens() -> i32 {
+ /// 0
+ /// }
+ ///
- /// // Bad
- /// foo((0));
- ///
- /// // Good
+ /// # fn foo(bar: usize) {}
+ /// foo(0);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DOUBLE_PARENS,
+ complexity,
+ "Warn on unnecessary double parentheses"
+}
+
+declare_lint_pass!(DoubleParens => [DOUBLE_PARENS]);
+
+impl EarlyLintPass for DoubleParens {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ if expr.span.from_expansion() {
+ return;
+ }
+
+ let msg: &str = "consider removing unnecessary double parentheses";
+
+ match expr.kind {
+ ExprKind::Paren(ref in_paren) => match in_paren.kind {
+ ExprKind::Paren(_) | ExprKind::Tup(_) => {
+ span_lint(cx, DOUBLE_PARENS, expr.span, msg);
+ },
+ _ => {},
+ },
+ ExprKind::Call(_, ref params) => {
+ if params.len() == 1 {
+ let param = ¶ms[0];
+ if let ExprKind::Paren(_) = param.kind {
+ span_lint(cx, DOUBLE_PARENS, param.span, msg);
+ }
+ }
+ },
+ ExprKind::MethodCall(_, ref params, _) => {
+ if params.len() == 2 {
+ let param = ¶ms[1];
+ if let ExprKind::Paren(_) = param.kind {
+ span_lint(cx, DOUBLE_PARENS, param.span, msg);
+ }
+ }
+ },
+ _ => {},
+ }
+ }
+}
--- /dev/null
- /// let dur = Duration::new(5, 0);
- ///
- /// // Bad
- /// let _micros = dur.subsec_nanos() / 1_000;
- /// let _millis = dur.subsec_nanos() / 1_000_000;
+use clippy_utils::consts::{constant, Constant};
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::ty::is_type_diagnostic_item;
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Spanned;
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calculation of subsecond microseconds or milliseconds
+ /// from other `Duration` methods.
+ ///
+ /// ### Why is this bad?
+ /// It's more concise to call `Duration::subsec_micros()` or
+ /// `Duration::subsec_millis()` than to calculate them.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::time::Duration;
- /// // Good
- /// let _micros = dur.subsec_micros();
- /// let _millis = dur.subsec_millis();
++ /// # let duration = Duration::new(5, 0);
++ /// let micros = duration.subsec_nanos() / 1_000;
++ /// let millis = duration.subsec_nanos() / 1_000_000;
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # use std::time::Duration;
++ /// # let duration = Duration::new(5, 0);
++ /// let micros = duration.subsec_micros();
++ /// let millis = duration.subsec_millis();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DURATION_SUBSEC,
+ complexity,
+ "checks for calculation of subsecond microseconds or milliseconds"
+}
+
+declare_lint_pass!(DurationSubsec => [DURATION_SUBSEC]);
+
+impl<'tcx> LateLintPass<'tcx> for DurationSubsec {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Binary(Spanned { node: BinOpKind::Div, .. }, left, right) = expr.kind;
+ if let ExprKind::MethodCall(method_path, args, _) = left.kind;
+ if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&args[0]).peel_refs(), sym::Duration);
+ if let Some((Constant::Int(divisor), _)) = constant(cx, cx.typeck_results(), right);
+ then {
+ let suggested_fn = match (method_path.ident.as_str(), divisor) {
+ ("subsec_micros", 1_000) | ("subsec_nanos", 1_000_000) => "subsec_millis",
+ ("subsec_nanos", 1_000) => "subsec_micros",
+ _ => return,
+ };
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ DURATION_SUBSEC,
+ expr.span,
+ &format!("calling `{}()` is more concise than this calculation", suggested_fn),
+ "try",
+ format!(
+ "{}.{}()",
+ snippet_with_applicability(cx, args[0].span, "_", &mut applicability),
+ suggested_fn
+ ),
+ applicability,
+ );
+ }
+ }
+ }
+}
--- /dev/null
- /// Could be written:
+//! Lint on if expressions with an else if, but without a final else branch.
+
+use clippy_utils::diagnostics::span_lint_and_help;
+use rustc_ast::ast::{Expr, ExprKind};
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of if expressions with an `else if` branch,
+ /// but without a final `else` branch.
+ ///
+ /// ### Why is this bad?
+ /// Some coding guidelines require this (e.g., MISRA-C:2004 Rule 14.10).
+ ///
+ /// ### Example
+ /// ```rust
+ /// # fn a() {}
+ /// # fn b() {}
+ /// # let x: i32 = 1;
+ /// if x.is_positive() {
+ /// a();
+ /// } else if x.is_negative() {
+ /// b();
+ /// }
+ /// ```
+ ///
++ /// Use instead:
+ ///
+ /// ```rust
+ /// # fn a() {}
+ /// # fn b() {}
+ /// # let x: i32 = 1;
+ /// if x.is_positive() {
+ /// a();
+ /// } else if x.is_negative() {
+ /// b();
+ /// } else {
+ /// // We don't care about zero.
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ELSE_IF_WITHOUT_ELSE,
+ restriction,
+ "`if` expression with an `else if`, but without a final `else` branch"
+}
+
+declare_lint_pass!(ElseIfWithoutElse => [ELSE_IF_WITHOUT_ELSE]);
+
+impl EarlyLintPass for ElseIfWithoutElse {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, mut item: &Expr) {
+ if in_external_macro(cx.sess(), item.span) {
+ return;
+ }
+
+ while let ExprKind::If(_, _, Some(ref els)) = item.kind {
+ if let ExprKind::If(_, _, None) = els.kind {
+ span_lint_and_help(
+ cx,
+ ELSE_IF_WITHOUT_ELSE,
+ els.span,
+ "`if` expression with an `else if`, but without a final `else`",
+ None,
+ "add an `else` block here",
+ );
+ }
+
+ item = els;
+ }
+ }
+}
--- /dev/null
- /// Bad:
+//! lint when there is an enum with no variants
+
+use clippy_utils::diagnostics::span_lint_and_help;
+use rustc_hir::{Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `enum`s with no variants.
+ ///
+ /// As of this writing, the `never_type` is still a
+ /// nightly-only experimental API. Therefore, this lint is only triggered
+ /// if the `never_type` is enabled.
+ ///
+ /// ### Why is this bad?
+ /// If you want to introduce a type which
+ /// can't be instantiated, you should use `!` (the primitive type "never"),
+ /// or a wrapper around it, because `!` has more extensive
+ /// compiler support (type inference, etc...) and wrappers
+ /// around it are the conventional way to define an uninhabited type.
+ /// For further information visit [never type documentation](https://doc.rust-lang.org/std/primitive.never.html)
+ ///
+ ///
+ /// ### Example
- /// Good:
+ /// ```rust
+ /// enum Test {}
+ /// ```
+ ///
++ /// Use instead:
+ /// ```rust
+ /// #![feature(never_type)]
+ ///
+ /// struct Test(!);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EMPTY_ENUM,
+ pedantic,
+ "enum with no variants"
+}
+
+declare_lint_pass!(EmptyEnum => [EMPTY_ENUM]);
+
+impl<'tcx> LateLintPass<'tcx> for EmptyEnum {
+ fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
+ // Only suggest the `never_type` if the feature is enabled
+ if !cx.tcx.features().never_type {
+ return;
+ }
+
+ if let ItemKind::Enum(..) = item.kind {
+ let ty = cx.tcx.type_of(item.def_id);
+ let adt = ty.ty_adt_def().expect("already checked whether this is an enum");
+ if adt.variants().is_empty() {
+ span_lint_and_help(
+ cx,
+ EMPTY_ENUM,
+ item.span,
+ "enum with no variants",
+ None,
+ "consider using the uninhabited type `!` (never type) or a wrapper \
+ around it to introduce a type which can't be instantiated",
+ );
+ }
+ }
+ }
+}
--- /dev/null
- /// can both be rewritten as:
+use clippy_utils::higher;
+use clippy_utils::{
+ can_move_expr_to_closure_no_visit,
+ diagnostics::span_lint_and_sugg,
+ is_expr_final_block_expr, is_expr_used_or_unified, match_def_path, paths, peel_hir_expr_while,
+ source::{reindent_multiline, snippet_indent, snippet_with_applicability, snippet_with_context},
+ SpanlessEq,
+};
+use core::fmt::Write;
+use rustc_errors::Applicability;
+use rustc_hir::{
+ hir_id::HirIdSet,
+ intravisit::{walk_expr, Visitor},
+ Block, Expr, ExprKind, Guard, HirId, Let, Pat, Stmt, StmtKind, UnOp,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::{Span, SyntaxContext, DUMMY_SP};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for uses of `contains_key` + `insert` on `HashMap`
+ /// or `BTreeMap`.
+ ///
+ /// ### Why is this bad?
+ /// Using `entry` is more efficient.
+ ///
+ /// ### Known problems
+ /// The suggestion may have type inference errors in some cases. e.g.
+ /// ```rust
+ /// let mut map = std::collections::HashMap::new();
+ /// let _ = if !map.contains_key(&0) {
+ /// map.insert(0, 0)
+ /// } else {
+ /// None
+ /// };
+ /// ```
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::collections::HashMap;
+ /// # let mut map = HashMap::new();
+ /// # let k = 1;
+ /// # let v = 1;
+ /// if !map.contains_key(&k) {
+ /// map.insert(k, v);
+ /// }
+ /// ```
++ /// Use instead:
+ /// ```rust
+ /// # use std::collections::HashMap;
+ /// # let mut map = HashMap::new();
+ /// # let k = 1;
+ /// # let v = 1;
+ /// map.entry(k).or_insert(v);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MAP_ENTRY,
+ perf,
+ "use of `contains_key` followed by `insert` on a `HashMap` or `BTreeMap`"
+}
+
+declare_lint_pass!(HashMapPass => [MAP_ENTRY]);
+
+impl<'tcx> LateLintPass<'tcx> for HashMapPass {
+ #[expect(clippy::too_many_lines)]
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ let (cond_expr, then_expr, else_expr) = match higher::If::hir(expr) {
+ Some(higher::If { cond, then, r#else }) => (cond, then, r#else),
+ _ => return,
+ };
+
+ let (map_ty, contains_expr) = match try_parse_contains(cx, cond_expr) {
+ Some(x) => x,
+ None => return,
+ };
+
+ let then_search = match find_insert_calls(cx, &contains_expr, then_expr) {
+ Some(x) => x,
+ None => return,
+ };
+
+ let mut app = Applicability::MachineApplicable;
+ let map_str = snippet_with_context(cx, contains_expr.map.span, contains_expr.call_ctxt, "..", &mut app).0;
+ let key_str = snippet_with_context(cx, contains_expr.key.span, contains_expr.call_ctxt, "..", &mut app).0;
+ let sugg = if let Some(else_expr) = else_expr {
+ let else_search = match find_insert_calls(cx, &contains_expr, else_expr) {
+ Some(search) => search,
+ None => return,
+ };
+
+ if then_search.edits.is_empty() && else_search.edits.is_empty() {
+ // No insertions
+ return;
+ } else if then_search.edits.is_empty() || else_search.edits.is_empty() {
+ // if .. { insert } else { .. } or if .. { .. } else { insert }
+ let ((then_str, entry_kind), else_str) = match (else_search.edits.is_empty(), contains_expr.negated) {
+ (true, true) => (
+ then_search.snippet_vacant(cx, then_expr.span, &mut app),
+ snippet_with_applicability(cx, else_expr.span, "{ .. }", &mut app),
+ ),
+ (true, false) => (
+ then_search.snippet_occupied(cx, then_expr.span, &mut app),
+ snippet_with_applicability(cx, else_expr.span, "{ .. }", &mut app),
+ ),
+ (false, true) => (
+ else_search.snippet_occupied(cx, else_expr.span, &mut app),
+ snippet_with_applicability(cx, then_expr.span, "{ .. }", &mut app),
+ ),
+ (false, false) => (
+ else_search.snippet_vacant(cx, else_expr.span, &mut app),
+ snippet_with_applicability(cx, then_expr.span, "{ .. }", &mut app),
+ ),
+ };
+ format!(
+ "if let {}::{} = {}.entry({}) {} else {}",
+ map_ty.entry_path(),
+ entry_kind,
+ map_str,
+ key_str,
+ then_str,
+ else_str,
+ )
+ } else {
+ // if .. { insert } else { insert }
+ let ((then_str, then_entry), (else_str, else_entry)) = if contains_expr.negated {
+ (
+ then_search.snippet_vacant(cx, then_expr.span, &mut app),
+ else_search.snippet_occupied(cx, else_expr.span, &mut app),
+ )
+ } else {
+ (
+ then_search.snippet_occupied(cx, then_expr.span, &mut app),
+ else_search.snippet_vacant(cx, else_expr.span, &mut app),
+ )
+ };
+ let indent_str = snippet_indent(cx, expr.span);
+ let indent_str = indent_str.as_deref().unwrap_or("");
+ format!(
+ "match {}.entry({}) {{\n{indent} {entry}::{} => {}\n\
+ {indent} {entry}::{} => {}\n{indent}}}",
+ map_str,
+ key_str,
+ then_entry,
+ reindent_multiline(then_str.into(), true, Some(4 + indent_str.len())),
+ else_entry,
+ reindent_multiline(else_str.into(), true, Some(4 + indent_str.len())),
+ entry = map_ty.entry_path(),
+ indent = indent_str,
+ )
+ }
+ } else {
+ if then_search.edits.is_empty() {
+ // no insertions
+ return;
+ }
+
+ // if .. { insert }
+ if !then_search.allow_insert_closure {
+ let (body_str, entry_kind) = if contains_expr.negated {
+ then_search.snippet_vacant(cx, then_expr.span, &mut app)
+ } else {
+ then_search.snippet_occupied(cx, then_expr.span, &mut app)
+ };
+ format!(
+ "if let {}::{} = {}.entry({}) {}",
+ map_ty.entry_path(),
+ entry_kind,
+ map_str,
+ key_str,
+ body_str,
+ )
+ } else if let Some(insertion) = then_search.as_single_insertion() {
+ let value_str = snippet_with_context(cx, insertion.value.span, then_expr.span.ctxt(), "..", &mut app).0;
+ if contains_expr.negated {
+ if insertion.value.can_have_side_effects() {
+ format!("{}.entry({}).or_insert_with(|| {});", map_str, key_str, value_str)
+ } else {
+ format!("{}.entry({}).or_insert({});", map_str, key_str, value_str)
+ }
+ } else {
+ // TODO: suggest using `if let Some(v) = map.get_mut(k) { .. }` here.
+ // This would need to be a different lint.
+ return;
+ }
+ } else {
+ let block_str = then_search.snippet_closure(cx, then_expr.span, &mut app);
+ if contains_expr.negated {
+ format!("{}.entry({}).or_insert_with(|| {});", map_str, key_str, block_str)
+ } else {
+ // TODO: suggest using `if let Some(v) = map.get_mut(k) { .. }` here.
+ // This would need to be a different lint.
+ return;
+ }
+ }
+ };
+
+ span_lint_and_sugg(
+ cx,
+ MAP_ENTRY,
+ expr.span,
+ &format!("usage of `contains_key` followed by `insert` on a `{}`", map_ty.name()),
+ "try this",
+ sugg,
+ app,
+ );
+ }
+}
+
+#[derive(Clone, Copy)]
+enum MapType {
+ Hash,
+ BTree,
+}
+impl MapType {
+ fn name(self) -> &'static str {
+ match self {
+ Self::Hash => "HashMap",
+ Self::BTree => "BTreeMap",
+ }
+ }
+ fn entry_path(self) -> &'static str {
+ match self {
+ Self::Hash => "std::collections::hash_map::Entry",
+ Self::BTree => "std::collections::btree_map::Entry",
+ }
+ }
+}
+
+struct ContainsExpr<'tcx> {
+ negated: bool,
+ map: &'tcx Expr<'tcx>,
+ key: &'tcx Expr<'tcx>,
+ call_ctxt: SyntaxContext,
+}
+fn try_parse_contains<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'_>) -> Option<(MapType, ContainsExpr<'tcx>)> {
+ let mut negated = false;
+ let expr = peel_hir_expr_while(expr, |e| match e.kind {
+ ExprKind::Unary(UnOp::Not, e) => {
+ negated = !negated;
+ Some(e)
+ },
+ _ => None,
+ });
+ match expr.kind {
+ ExprKind::MethodCall(
+ _,
+ [
+ map,
+ Expr {
+ kind: ExprKind::AddrOf(_, _, key),
+ span: key_span,
+ ..
+ },
+ ],
+ _,
+ ) if key_span.ctxt() == expr.span.ctxt() => {
+ let id = cx.typeck_results().type_dependent_def_id(expr.hir_id)?;
+ let expr = ContainsExpr {
+ negated,
+ map,
+ key,
+ call_ctxt: expr.span.ctxt(),
+ };
+ if match_def_path(cx, id, &paths::BTREEMAP_CONTAINS_KEY) {
+ Some((MapType::BTree, expr))
+ } else if match_def_path(cx, id, &paths::HASHMAP_CONTAINS_KEY) {
+ Some((MapType::Hash, expr))
+ } else {
+ None
+ }
+ },
+ _ => None,
+ }
+}
+
+struct InsertExpr<'tcx> {
+ map: &'tcx Expr<'tcx>,
+ key: &'tcx Expr<'tcx>,
+ value: &'tcx Expr<'tcx>,
+}
+fn try_parse_insert<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<InsertExpr<'tcx>> {
+ if let ExprKind::MethodCall(_, [map, key, value], _) = expr.kind {
+ let id = cx.typeck_results().type_dependent_def_id(expr.hir_id)?;
+ if match_def_path(cx, id, &paths::BTREEMAP_INSERT) || match_def_path(cx, id, &paths::HASHMAP_INSERT) {
+ Some(InsertExpr { map, key, value })
+ } else {
+ None
+ }
+ } else {
+ None
+ }
+}
+
+/// An edit that will need to be made to move the expression to use the entry api
+#[derive(Clone, Copy)]
+enum Edit<'tcx> {
+ /// A semicolon that needs to be removed. Used to create a closure for `insert_with`.
+ RemoveSemi(Span),
+ /// An insertion into the map.
+ Insertion(Insertion<'tcx>),
+}
+impl<'tcx> Edit<'tcx> {
+ fn as_insertion(self) -> Option<Insertion<'tcx>> {
+ if let Self::Insertion(i) = self { Some(i) } else { None }
+ }
+}
+#[derive(Clone, Copy)]
+struct Insertion<'tcx> {
+ call: &'tcx Expr<'tcx>,
+ value: &'tcx Expr<'tcx>,
+}
+
+/// This visitor needs to do a multiple things:
+/// * Find all usages of the map. An insertion can only be made before any other usages of the map.
+/// * Determine if there's an insertion using the same key. There's no need for the entry api
+/// otherwise.
+/// * Determine if the final statement executed is an insertion. This is needed to use
+/// `or_insert_with`.
+/// * Determine if there's any sub-expression that can't be placed in a closure.
+/// * Determine if there's only a single insert statement. `or_insert` can be used in this case.
+#[expect(clippy::struct_excessive_bools)]
+struct InsertSearcher<'cx, 'tcx> {
+ cx: &'cx LateContext<'tcx>,
+ /// The map expression used in the contains call.
+ map: &'tcx Expr<'tcx>,
+ /// The key expression used in the contains call.
+ key: &'tcx Expr<'tcx>,
+ /// The context of the top level block. All insert calls must be in the same context.
+ ctxt: SyntaxContext,
+ /// Whether this expression can be safely moved into a closure.
+ allow_insert_closure: bool,
+ /// Whether this expression can use the entry api.
+ can_use_entry: bool,
+ /// Whether this expression is the final expression in this code path. This may be a statement.
+ in_tail_pos: bool,
+ // Is this expression a single insert. A slightly better suggestion can be made in this case.
+ is_single_insert: bool,
+ /// If the visitor has seen the map being used.
+ is_map_used: bool,
+ /// The locations where changes need to be made for the suggestion.
+ edits: Vec<Edit<'tcx>>,
+ /// A stack of loops the visitor is currently in.
+ loops: Vec<HirId>,
+ /// Local variables created in the expression. These don't need to be captured.
+ locals: HirIdSet,
+}
+impl<'tcx> InsertSearcher<'_, 'tcx> {
+ /// Visit the expression as a branch in control flow. Multiple insert calls can be used, but
+ /// only if they are on separate code paths. This will return whether the map was used in the
+ /// given expression.
+ fn visit_cond_arm(&mut self, e: &'tcx Expr<'_>) -> bool {
+ let is_map_used = self.is_map_used;
+ let in_tail_pos = self.in_tail_pos;
+ self.visit_expr(e);
+ let res = self.is_map_used;
+ self.is_map_used = is_map_used;
+ self.in_tail_pos = in_tail_pos;
+ res
+ }
+
+ /// Visits an expression which is not itself in a tail position, but other sibling expressions
+ /// may be. e.g. if conditions
+ fn visit_non_tail_expr(&mut self, e: &'tcx Expr<'_>) {
+ let in_tail_pos = self.in_tail_pos;
+ self.in_tail_pos = false;
+ self.visit_expr(e);
+ self.in_tail_pos = in_tail_pos;
+ }
+}
+impl<'tcx> Visitor<'tcx> for InsertSearcher<'_, 'tcx> {
+ fn visit_stmt(&mut self, stmt: &'tcx Stmt<'_>) {
+ match stmt.kind {
+ StmtKind::Semi(e) => {
+ self.visit_expr(e);
+
+ if self.in_tail_pos && self.allow_insert_closure {
+ // The spans are used to slice the top level expression into multiple parts. This requires that
+ // they all come from the same part of the source code.
+ if stmt.span.ctxt() == self.ctxt && e.span.ctxt() == self.ctxt {
+ self.edits
+ .push(Edit::RemoveSemi(stmt.span.trim_start(e.span).unwrap_or(DUMMY_SP)));
+ } else {
+ self.allow_insert_closure = false;
+ }
+ }
+ },
+ StmtKind::Expr(e) => self.visit_expr(e),
+ StmtKind::Local(l) => {
+ self.visit_pat(l.pat);
+ if let Some(e) = l.init {
+ self.allow_insert_closure &= !self.in_tail_pos;
+ self.in_tail_pos = false;
+ self.is_single_insert = false;
+ self.visit_expr(e);
+ }
+ },
+ StmtKind::Item(_) => {
+ self.allow_insert_closure &= !self.in_tail_pos;
+ self.is_single_insert = false;
+ },
+ }
+ }
+
+ fn visit_block(&mut self, block: &'tcx Block<'_>) {
+ // If the block is in a tail position, then the last expression (possibly a statement) is in the
+ // tail position. The rest, however, are not.
+ match (block.stmts, block.expr) {
+ ([], None) => {
+ self.allow_insert_closure &= !self.in_tail_pos;
+ },
+ ([], Some(expr)) => self.visit_expr(expr),
+ (stmts, Some(expr)) => {
+ let in_tail_pos = self.in_tail_pos;
+ self.in_tail_pos = false;
+ for stmt in stmts {
+ self.visit_stmt(stmt);
+ }
+ self.in_tail_pos = in_tail_pos;
+ self.visit_expr(expr);
+ },
+ ([stmts @ .., stmt], None) => {
+ let in_tail_pos = self.in_tail_pos;
+ self.in_tail_pos = false;
+ for stmt in stmts {
+ self.visit_stmt(stmt);
+ }
+ self.in_tail_pos = in_tail_pos;
+ self.visit_stmt(stmt);
+ },
+ }
+ }
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if !self.can_use_entry {
+ return;
+ }
+
+ match try_parse_insert(self.cx, expr) {
+ Some(insert_expr) if SpanlessEq::new(self.cx).eq_expr(self.map, insert_expr.map) => {
+ // Multiple inserts, inserts with a different key, and inserts from a macro can't use the entry api.
+ if self.is_map_used
+ || !SpanlessEq::new(self.cx).eq_expr(self.key, insert_expr.key)
+ || expr.span.ctxt() != self.ctxt
+ {
+ self.can_use_entry = false;
+ return;
+ }
+
+ self.edits.push(Edit::Insertion(Insertion {
+ call: expr,
+ value: insert_expr.value,
+ }));
+ self.is_map_used = true;
+ self.allow_insert_closure &= self.in_tail_pos;
+
+ // The value doesn't affect whether there is only a single insert expression.
+ let is_single_insert = self.is_single_insert;
+ self.visit_non_tail_expr(insert_expr.value);
+ self.is_single_insert = is_single_insert;
+ },
+ _ if SpanlessEq::new(self.cx).eq_expr(self.map, expr) => {
+ self.is_map_used = true;
+ },
+ _ => match expr.kind {
+ ExprKind::If(cond_expr, then_expr, Some(else_expr)) => {
+ self.is_single_insert = false;
+ self.visit_non_tail_expr(cond_expr);
+ // Each branch may contain it's own insert expression.
+ let mut is_map_used = self.visit_cond_arm(then_expr);
+ is_map_used |= self.visit_cond_arm(else_expr);
+ self.is_map_used = is_map_used;
+ },
+ ExprKind::Match(scrutinee_expr, arms, _) => {
+ self.is_single_insert = false;
+ self.visit_non_tail_expr(scrutinee_expr);
+ // Each branch may contain it's own insert expression.
+ let mut is_map_used = self.is_map_used;
+ for arm in arms {
+ self.visit_pat(arm.pat);
+ if let Some(Guard::If(guard) | Guard::IfLet(&Let { init: guard, .. })) = arm.guard {
+ self.visit_non_tail_expr(guard);
+ }
+ is_map_used |= self.visit_cond_arm(arm.body);
+ }
+ self.is_map_used = is_map_used;
+ },
+ ExprKind::Loop(block, ..) => {
+ self.loops.push(expr.hir_id);
+ self.is_single_insert = false;
+ self.allow_insert_closure &= !self.in_tail_pos;
+ // Don't allow insertions inside of a loop.
+ let edit_len = self.edits.len();
+ self.visit_block(block);
+ if self.edits.len() != edit_len {
+ self.can_use_entry = false;
+ }
+ self.loops.pop();
+ },
+ ExprKind::Block(block, _) => self.visit_block(block),
+ ExprKind::InlineAsm(_) => {
+ self.can_use_entry = false;
+ },
+ _ => {
+ self.allow_insert_closure &= !self.in_tail_pos;
+ self.allow_insert_closure &=
+ can_move_expr_to_closure_no_visit(self.cx, expr, &self.loops, &self.locals);
+ // Sub expressions are no longer in the tail position.
+ self.is_single_insert = false;
+ self.in_tail_pos = false;
+ walk_expr(self, expr);
+ },
+ },
+ }
+ }
+
+ fn visit_pat(&mut self, p: &'tcx Pat<'tcx>) {
+ p.each_binding_or_first(&mut |_, id, _, _| {
+ self.locals.insert(id);
+ });
+ }
+}
+
+struct InsertSearchResults<'tcx> {
+ edits: Vec<Edit<'tcx>>,
+ allow_insert_closure: bool,
+ is_single_insert: bool,
+}
+impl<'tcx> InsertSearchResults<'tcx> {
+ fn as_single_insertion(&self) -> Option<Insertion<'tcx>> {
+ self.is_single_insert.then(|| self.edits[0].as_insertion().unwrap())
+ }
+
+ fn snippet(
+ &self,
+ cx: &LateContext<'_>,
+ mut span: Span,
+ app: &mut Applicability,
+ write_wrapped: impl Fn(&mut String, Insertion<'_>, SyntaxContext, &mut Applicability),
+ ) -> String {
+ let ctxt = span.ctxt();
+ let mut res = String::new();
+ for insertion in self.edits.iter().filter_map(|e| e.as_insertion()) {
+ res.push_str(&snippet_with_applicability(
+ cx,
+ span.until(insertion.call.span),
+ "..",
+ app,
+ ));
+ if is_expr_used_or_unified(cx.tcx, insertion.call) {
+ write_wrapped(&mut res, insertion, ctxt, app);
+ } else {
+ let _ = write!(
+ res,
+ "e.insert({})",
+ snippet_with_context(cx, insertion.value.span, ctxt, "..", app).0
+ );
+ }
+ span = span.trim_start(insertion.call.span).unwrap_or(DUMMY_SP);
+ }
+ res.push_str(&snippet_with_applicability(cx, span, "..", app));
+ res
+ }
+
+ fn snippet_occupied(&self, cx: &LateContext<'_>, span: Span, app: &mut Applicability) -> (String, &'static str) {
+ (
+ self.snippet(cx, span, app, |res, insertion, ctxt, app| {
+ // Insertion into a map would return `Some(&mut value)`, but the entry returns `&mut value`
+ let _ = write!(
+ res,
+ "Some(e.insert({}))",
+ snippet_with_context(cx, insertion.value.span, ctxt, "..", app).0
+ );
+ }),
+ "Occupied(mut e)",
+ )
+ }
+
+ fn snippet_vacant(&self, cx: &LateContext<'_>, span: Span, app: &mut Applicability) -> (String, &'static str) {
+ (
+ self.snippet(cx, span, app, |res, insertion, ctxt, app| {
+ // Insertion into a map would return `None`, but the entry returns a mutable reference.
+ let _ = if is_expr_final_block_expr(cx.tcx, insertion.call) {
+ write!(
+ res,
+ "e.insert({});\n{}None",
+ snippet_with_context(cx, insertion.value.span, ctxt, "..", app).0,
+ snippet_indent(cx, insertion.call.span).as_deref().unwrap_or(""),
+ )
+ } else {
+ write!(
+ res,
+ "{{ e.insert({}); None }}",
+ snippet_with_context(cx, insertion.value.span, ctxt, "..", app).0,
+ )
+ };
+ }),
+ "Vacant(e)",
+ )
+ }
+
+ fn snippet_closure(&self, cx: &LateContext<'_>, mut span: Span, app: &mut Applicability) -> String {
+ let ctxt = span.ctxt();
+ let mut res = String::new();
+ for edit in &self.edits {
+ match *edit {
+ Edit::Insertion(insertion) => {
+ // Cut out the value from `map.insert(key, value)`
+ res.push_str(&snippet_with_applicability(
+ cx,
+ span.until(insertion.call.span),
+ "..",
+ app,
+ ));
+ res.push_str(&snippet_with_context(cx, insertion.value.span, ctxt, "..", app).0);
+ span = span.trim_start(insertion.call.span).unwrap_or(DUMMY_SP);
+ },
+ Edit::RemoveSemi(semi_span) => {
+ // Cut out the semicolon. This allows the value to be returned from the closure.
+ res.push_str(&snippet_with_applicability(cx, span.until(semi_span), "..", app));
+ span = span.trim_start(semi_span).unwrap_or(DUMMY_SP);
+ },
+ }
+ }
+ res.push_str(&snippet_with_applicability(cx, span, "..", app));
+ res
+ }
+}
+
+fn find_insert_calls<'tcx>(
+ cx: &LateContext<'tcx>,
+ contains_expr: &ContainsExpr<'tcx>,
+ expr: &'tcx Expr<'_>,
+) -> Option<InsertSearchResults<'tcx>> {
+ let mut s = InsertSearcher {
+ cx,
+ map: contains_expr.map,
+ key: contains_expr.key,
+ ctxt: expr.span.ctxt(),
+ edits: Vec::new(),
+ is_map_used: false,
+ allow_insert_closure: true,
+ can_use_entry: true,
+ in_tail_pos: true,
+ is_single_insert: true,
+ loops: Vec::new(),
+ locals: HirIdSet::default(),
+ };
+ s.visit_expr(expr);
+ let allow_insert_closure = s.allow_insert_closure;
+ let is_single_insert = s.is_single_insert;
+ let edits = s.edits;
+ s.can_use_entry.then(|| InsertSearchResults {
+ edits,
+ allow_insert_closure,
+ is_single_insert,
+ })
+}
--- /dev/null
- /// Could be written as:
+//! lint on enum variants that are prefixed or suffixed by the same characters
+
+use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
+use clippy_utils::source::is_present_in_source;
+use clippy_utils::str_utils::{camel_case_split, count_match_end, count_match_start};
+use rustc_hir::{EnumDef, Item, ItemKind, Variant};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+use rustc_span::symbol::Symbol;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Detects enumeration variants that are prefixed or suffixed
+ /// by the same characters.
+ ///
+ /// ### Why is this bad?
+ /// Enumeration variant names should specify their variant,
+ /// not repeat the enumeration name.
+ ///
+ /// ### Limitations
+ /// Characters with no casing will be considered when comparing prefixes/suffixes
+ /// This applies to numbers and non-ascii characters without casing
+ /// e.g. `Foo1` and `Foo2` is considered to have different prefixes
+ /// (the prefixes are `Foo1` and `Foo2` respectively), as also `Bar螃`, `Bar蟹`
+ ///
+ /// ### Example
+ /// ```rust
+ /// enum Cake {
+ /// BlackForestCake,
+ /// HummingbirdCake,
+ /// BattenbergCake,
+ /// }
+ /// ```
++ /// Use instead:
+ /// ```rust
+ /// enum Cake {
+ /// BlackForest,
+ /// Hummingbird,
+ /// Battenberg,
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ENUM_VARIANT_NAMES,
+ style,
+ "enums where all variants share a prefix/postfix"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Detects type names that are prefixed or suffixed by the
+ /// containing module's name.
+ ///
+ /// ### Why is this bad?
+ /// It requires the user to type the module name twice.
+ ///
+ /// ### Example
+ /// ```rust
+ /// mod cake {
+ /// struct BlackForestCake;
+ /// }
+ /// ```
+ /// Could be written as:
+ /// ```rust
+ /// mod cake {
+ /// struct BlackForest;
+ /// }
+ /// ```
+ #[clippy::version = "1.33.0"]
+ pub MODULE_NAME_REPETITIONS,
+ pedantic,
+ "type names prefixed/postfixed with their containing module's name"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for modules that have the same name as their
+ /// parent module
+ ///
+ /// ### Why is this bad?
+ /// A typical beginner mistake is to have `mod foo;` and
+ /// again `mod foo { ..
+ /// }` in `foo.rs`.
+ /// The expectation is that items inside the inner `mod foo { .. }` are then
+ /// available
+ /// through `foo::x`, but they are only available through
+ /// `foo::foo::x`.
+ /// If this is done on purpose, it would be better to choose a more
+ /// representative module name.
+ ///
+ /// ### Example
+ /// ```ignore
+ /// // lib.rs
+ /// mod foo;
+ /// // foo.rs
+ /// mod foo {
+ /// ...
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MODULE_INCEPTION,
+ style,
+ "modules that have the same name as their parent module"
+}
+
+pub struct EnumVariantNames {
+ modules: Vec<(Symbol, String)>,
+ threshold: u64,
+ avoid_breaking_exported_api: bool,
+}
+
+impl EnumVariantNames {
+ #[must_use]
+ pub fn new(threshold: u64, avoid_breaking_exported_api: bool) -> Self {
+ Self {
+ modules: Vec::new(),
+ threshold,
+ avoid_breaking_exported_api,
+ }
+ }
+}
+
+impl_lint_pass!(EnumVariantNames => [
+ ENUM_VARIANT_NAMES,
+ MODULE_NAME_REPETITIONS,
+ MODULE_INCEPTION
+]);
+
+fn check_enum_start(cx: &LateContext<'_>, item_name: &str, variant: &Variant<'_>) {
+ let name = variant.ident.name.as_str();
+ let item_name_chars = item_name.chars().count();
+
+ if count_match_start(item_name, name).char_count == item_name_chars
+ && name.chars().nth(item_name_chars).map_or(false, |c| !c.is_lowercase())
+ && name.chars().nth(item_name_chars + 1).map_or(false, |c| !c.is_numeric())
+ {
+ span_lint(
+ cx,
+ ENUM_VARIANT_NAMES,
+ variant.span,
+ "variant name starts with the enum's name",
+ );
+ }
+}
+
+fn check_enum_end(cx: &LateContext<'_>, item_name: &str, variant: &Variant<'_>) {
+ let name = variant.ident.name.as_str();
+ let item_name_chars = item_name.chars().count();
+
+ if count_match_end(item_name, name).char_count == item_name_chars {
+ span_lint(
+ cx,
+ ENUM_VARIANT_NAMES,
+ variant.span,
+ "variant name ends with the enum's name",
+ );
+ }
+}
+
+fn check_variant(cx: &LateContext<'_>, threshold: u64, def: &EnumDef<'_>, item_name: &str, span: Span) {
+ if (def.variants.len() as u64) < threshold {
+ return;
+ }
+
+ let first = &def.variants[0].ident.name.as_str();
+ let mut pre = camel_case_split(first);
+ let mut post = pre.clone();
+ post.reverse();
+ for var in def.variants {
+ check_enum_start(cx, item_name, var);
+ check_enum_end(cx, item_name, var);
+ let name = var.ident.name.as_str();
+
+ let variant_split = camel_case_split(name);
+ if variant_split.len() == 1 {
+ return;
+ }
+
+ pre = pre
+ .iter()
+ .zip(variant_split.iter())
+ .take_while(|(a, b)| a == b)
+ .map(|e| *e.0)
+ .collect();
+ post = post
+ .iter()
+ .zip(variant_split.iter().rev())
+ .take_while(|(a, b)| a == b)
+ .map(|e| *e.0)
+ .collect();
+ }
+ let (what, value) = match (pre.is_empty(), post.is_empty()) {
+ (true, true) => return,
+ (false, _) => ("pre", pre.join("")),
+ (true, false) => {
+ post.reverse();
+ ("post", post.join(""))
+ },
+ };
+ span_lint_and_help(
+ cx,
+ ENUM_VARIANT_NAMES,
+ span,
+ &format!("all variants have the same {}fix: `{}`", what, value),
+ None,
+ &format!(
+ "remove the {}fixes and use full paths to \
+ the variants instead of glob imports",
+ what
+ ),
+ );
+}
+
+#[must_use]
+fn to_camel_case(item_name: &str) -> String {
+ let mut s = String::new();
+ let mut up = true;
+ for c in item_name.chars() {
+ if c.is_uppercase() {
+ // we only turn snake case text into CamelCase
+ return item_name.to_string();
+ }
+ if c == '_' {
+ up = true;
+ continue;
+ }
+ if up {
+ up = false;
+ s.extend(c.to_uppercase());
+ } else {
+ s.push(c);
+ }
+ }
+ s
+}
+
+impl LateLintPass<'_> for EnumVariantNames {
+ fn check_item_post(&mut self, _cx: &LateContext<'_>, _item: &Item<'_>) {
+ let last = self.modules.pop();
+ assert!(last.is_some());
+ }
+
+ #[expect(clippy::similar_names)]
+ fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
+ let item_name = item.ident.name.as_str();
+ let item_camel = to_camel_case(item_name);
+ if !item.span.from_expansion() && is_present_in_source(cx, item.span) {
+ if let Some(&(ref mod_name, ref mod_camel)) = self.modules.last() {
+ // constants don't have surrounding modules
+ if !mod_camel.is_empty() {
+ if mod_name == &item.ident.name {
+ if let ItemKind::Mod(..) = item.kind {
+ span_lint(
+ cx,
+ MODULE_INCEPTION,
+ item.span,
+ "module has the same name as its containing module",
+ );
+ }
+ }
+ // The `module_name_repetitions` lint should only trigger if the item has the module in its
+ // name. Having the same name is accepted.
+ if cx.tcx.visibility(item.def_id).is_public() && item_camel.len() > mod_camel.len() {
+ let matching = count_match_start(mod_camel, &item_camel);
+ let rmatching = count_match_end(mod_camel, &item_camel);
+ let nchars = mod_camel.chars().count();
+
+ let is_word_beginning = |c: char| c == '_' || c.is_uppercase() || c.is_numeric();
+
+ if matching.char_count == nchars {
+ match item_camel.chars().nth(nchars) {
+ Some(c) if is_word_beginning(c) => span_lint(
+ cx,
+ MODULE_NAME_REPETITIONS,
+ item.span,
+ "item name starts with its containing module's name",
+ ),
+ _ => (),
+ }
+ }
+ if rmatching.char_count == nchars {
+ span_lint(
+ cx,
+ MODULE_NAME_REPETITIONS,
+ item.span,
+ "item name ends with its containing module's name",
+ );
+ }
+ }
+ }
+ }
+ }
+ if let ItemKind::Enum(ref def, _) = item.kind {
+ if !(self.avoid_breaking_exported_api && cx.access_levels.is_exported(item.def_id)) {
+ check_variant(cx, self.threshold, def, item_name, item.span);
+ }
+ }
+ self.modules.push((item.ident.name, item_camel));
+ }
+}
--- /dev/null
- /// ```
- /// or
- /// ```rust
+use clippy_utils::diagnostics::{multispan_sugg, span_lint, span_lint_and_then};
+use clippy_utils::get_enclosing_block;
+use clippy_utils::macros::{find_assert_eq_args, first_node_macro_backtrace};
+use clippy_utils::source::snippet;
+use clippy_utils::ty::{implements_trait, is_copy};
+use clippy_utils::{ast_utils::is_useless_with_eq_exprs, eq_expr_value, is_in_test_function};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{def::Res, def_id::DefId, BinOpKind, BorrowKind, Expr, ExprKind, GenericArg, ItemKind, QPath, TyKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for equal operands to comparison, logical and
+ /// bitwise, difference and division binary operators (`==`, `>`, etc., `&&`,
+ /// `||`, `&`, `|`, `^`, `-` and `/`).
+ ///
+ /// ### Why is this bad?
+ /// This is usually just a typo or a copy and paste error.
+ ///
+ /// ### Known problems
+ /// False negatives: We had some false positives regarding
+ /// calls (notably [racer](https://github.com/phildawes/racer) had one instance
+ /// of `x.pop() && x.pop()`), so we removed matching any function or method
+ /// calls. We may introduce a list of known pure functions in the future.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let x = 1;
+ /// if x + 1 == x + 1 {}
++ ///
++ /// // or
++ ///
+ /// # let a = 3;
+ /// # let b = 4;
+ /// assert_eq!(a, a);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EQ_OP,
+ correctness,
+ "equal operands on both sides of a comparison or bitwise combination (e.g., `x == x`)"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for arguments to `==` which have their address
+ /// taken to satisfy a bound
+ /// and suggests to dereference the other argument instead
+ ///
+ /// ### Why is this bad?
+ /// It is more idiomatic to dereference the other argument.
+ ///
+ /// ### Known problems
+ /// None
+ ///
+ /// ### Example
+ /// ```ignore
+ /// // Bad
+ /// &x == y
+ ///
+ /// // Good
+ /// x == *y
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub OP_REF,
+ style,
+ "taking a reference to satisfy the type constraints on `==`"
+}
+
+declare_lint_pass!(EqOp => [EQ_OP, OP_REF]);
+
+impl<'tcx> LateLintPass<'tcx> for EqOp {
+ #[expect(clippy::similar_names, clippy::too_many_lines)]
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ if_chain! {
+ if let Some((macro_call, macro_name)) = first_node_macro_backtrace(cx, e).find_map(|macro_call| {
+ let name = cx.tcx.item_name(macro_call.def_id);
+ matches!(name.as_str(), "assert_eq" | "assert_ne" | "debug_assert_eq" | "debug_assert_ne")
+ .then(|| (macro_call, name))
+ });
+ if let Some((lhs, rhs, _)) = find_assert_eq_args(cx, e, macro_call.expn);
+ if eq_expr_value(cx, lhs, rhs);
+ if macro_call.is_local();
+ if !is_in_test_function(cx.tcx, e.hir_id);
+ then {
+ span_lint(
+ cx,
+ EQ_OP,
+ lhs.span.to(rhs.span),
+ &format!("identical args used in this `{}!` macro call", macro_name),
+ );
+ }
+ }
+ if let ExprKind::Binary(op, left, right) = e.kind {
+ if e.span.from_expansion() {
+ return;
+ }
+ let macro_with_not_op = |expr_kind: &ExprKind<'_>| {
+ if let ExprKind::Unary(_, expr) = *expr_kind {
+ expr.span.from_expansion()
+ } else {
+ false
+ }
+ };
+ if macro_with_not_op(&left.kind) || macro_with_not_op(&right.kind) {
+ return;
+ }
+ if is_useless_with_eq_exprs(op.node.into())
+ && eq_expr_value(cx, left, right)
+ && !is_in_test_function(cx.tcx, e.hir_id)
+ {
+ span_lint(
+ cx,
+ EQ_OP,
+ e.span,
+ &format!("equal expressions as operands to `{}`", op.node.as_str()),
+ );
+ return;
+ }
+ let (trait_id, requires_ref) = match op.node {
+ BinOpKind::Add => (cx.tcx.lang_items().add_trait(), false),
+ BinOpKind::Sub => (cx.tcx.lang_items().sub_trait(), false),
+ BinOpKind::Mul => (cx.tcx.lang_items().mul_trait(), false),
+ BinOpKind::Div => (cx.tcx.lang_items().div_trait(), false),
+ BinOpKind::Rem => (cx.tcx.lang_items().rem_trait(), false),
+ // don't lint short circuiting ops
+ BinOpKind::And | BinOpKind::Or => return,
+ BinOpKind::BitXor => (cx.tcx.lang_items().bitxor_trait(), false),
+ BinOpKind::BitAnd => (cx.tcx.lang_items().bitand_trait(), false),
+ BinOpKind::BitOr => (cx.tcx.lang_items().bitor_trait(), false),
+ BinOpKind::Shl => (cx.tcx.lang_items().shl_trait(), false),
+ BinOpKind::Shr => (cx.tcx.lang_items().shr_trait(), false),
+ BinOpKind::Ne | BinOpKind::Eq => (cx.tcx.lang_items().eq_trait(), true),
+ BinOpKind::Lt | BinOpKind::Le | BinOpKind::Ge | BinOpKind::Gt => {
+ (cx.tcx.lang_items().partial_ord_trait(), true)
+ },
+ };
+ if let Some(trait_id) = trait_id {
+ match (&left.kind, &right.kind) {
+ // do not suggest to dereference literals
+ (&ExprKind::Lit(..), _) | (_, &ExprKind::Lit(..)) => {},
+ // &foo == &bar
+ (&ExprKind::AddrOf(BorrowKind::Ref, _, l), &ExprKind::AddrOf(BorrowKind::Ref, _, r)) => {
+ let lty = cx.typeck_results().expr_ty(l);
+ let rty = cx.typeck_results().expr_ty(r);
+ let lcpy = is_copy(cx, lty);
+ let rcpy = is_copy(cx, rty);
+ if let Some((self_ty, other_ty)) = in_impl(cx, e, trait_id) {
+ if (are_equal(cx, rty, self_ty) && are_equal(cx, lty, other_ty))
+ || (are_equal(cx, rty, other_ty) && are_equal(cx, lty, self_ty))
+ {
+ return; // Don't lint
+ }
+ }
+ // either operator autorefs or both args are copyable
+ if (requires_ref || (lcpy && rcpy)) && implements_trait(cx, lty, trait_id, &[rty.into()]) {
+ span_lint_and_then(
+ cx,
+ OP_REF,
+ e.span,
+ "needlessly taken reference of both operands",
+ |diag| {
+ let lsnip = snippet(cx, l.span, "...").to_string();
+ let rsnip = snippet(cx, r.span, "...").to_string();
+ multispan_sugg(
+ diag,
+ "use the values directly",
+ vec![(left.span, lsnip), (right.span, rsnip)],
+ );
+ },
+ );
+ } else if lcpy
+ && !rcpy
+ && implements_trait(cx, lty, trait_id, &[cx.typeck_results().expr_ty(right).into()])
+ {
+ span_lint_and_then(
+ cx,
+ OP_REF,
+ e.span,
+ "needlessly taken reference of left operand",
+ |diag| {
+ let lsnip = snippet(cx, l.span, "...").to_string();
+ diag.span_suggestion(
+ left.span,
+ "use the left value directly",
+ lsnip,
+ Applicability::MaybeIncorrect, // FIXME #2597
+ );
+ },
+ );
+ } else if !lcpy
+ && rcpy
+ && implements_trait(cx, cx.typeck_results().expr_ty(left), trait_id, &[rty.into()])
+ {
+ span_lint_and_then(
+ cx,
+ OP_REF,
+ e.span,
+ "needlessly taken reference of right operand",
+ |diag| {
+ let rsnip = snippet(cx, r.span, "...").to_string();
+ diag.span_suggestion(
+ right.span,
+ "use the right value directly",
+ rsnip,
+ Applicability::MaybeIncorrect, // FIXME #2597
+ );
+ },
+ );
+ }
+ },
+ // &foo == bar
+ (&ExprKind::AddrOf(BorrowKind::Ref, _, l), _) => {
+ let lty = cx.typeck_results().expr_ty(l);
+ if let Some((self_ty, other_ty)) = in_impl(cx, e, trait_id) {
+ let rty = cx.typeck_results().expr_ty(right);
+ if (are_equal(cx, rty, self_ty) && are_equal(cx, lty, other_ty))
+ || (are_equal(cx, rty, other_ty) && are_equal(cx, lty, self_ty))
+ {
+ return; // Don't lint
+ }
+ }
+ let lcpy = is_copy(cx, lty);
+ if (requires_ref || lcpy)
+ && implements_trait(cx, lty, trait_id, &[cx.typeck_results().expr_ty(right).into()])
+ {
+ span_lint_and_then(
+ cx,
+ OP_REF,
+ e.span,
+ "needlessly taken reference of left operand",
+ |diag| {
+ let lsnip = snippet(cx, l.span, "...").to_string();
+ diag.span_suggestion(
+ left.span,
+ "use the left value directly",
+ lsnip,
+ Applicability::MaybeIncorrect, // FIXME #2597
+ );
+ },
+ );
+ }
+ },
+ // foo == &bar
+ (_, &ExprKind::AddrOf(BorrowKind::Ref, _, r)) => {
+ let rty = cx.typeck_results().expr_ty(r);
+ if let Some((self_ty, other_ty)) = in_impl(cx, e, trait_id) {
+ let lty = cx.typeck_results().expr_ty(left);
+ if (are_equal(cx, rty, self_ty) && are_equal(cx, lty, other_ty))
+ || (are_equal(cx, rty, other_ty) && are_equal(cx, lty, self_ty))
+ {
+ return; // Don't lint
+ }
+ }
+ let rcpy = is_copy(cx, rty);
+ if (requires_ref || rcpy)
+ && implements_trait(cx, cx.typeck_results().expr_ty(left), trait_id, &[rty.into()])
+ {
+ span_lint_and_then(cx, OP_REF, e.span, "taken reference of right operand", |diag| {
+ let rsnip = snippet(cx, r.span, "...").to_string();
+ diag.span_suggestion(
+ right.span,
+ "use the right value directly",
+ rsnip,
+ Applicability::MaybeIncorrect, // FIXME #2597
+ );
+ });
+ }
+ },
+ _ => {},
+ }
+ }
+ }
+ }
+}
+
+fn in_impl<'tcx>(
+ cx: &LateContext<'tcx>,
+ e: &'tcx Expr<'_>,
+ bin_op: DefId,
+) -> Option<(&'tcx rustc_hir::Ty<'tcx>, &'tcx rustc_hir::Ty<'tcx>)> {
+ if_chain! {
+ if let Some(block) = get_enclosing_block(cx, e.hir_id);
+ if let Some(impl_def_id) = cx.tcx.impl_of_method(block.hir_id.owner.to_def_id());
+ let item = cx.tcx.hir().expect_item(impl_def_id.expect_local());
+ if let ItemKind::Impl(item) = &item.kind;
+ if let Some(of_trait) = &item.of_trait;
+ if let Some(seg) = of_trait.path.segments.last();
+ if let Some(Res::Def(_, trait_id)) = seg.res;
+ if trait_id == bin_op;
+ if let Some(generic_args) = seg.args;
+ if let Some(GenericArg::Type(other_ty)) = generic_args.args.last();
+
+ then {
+ Some((item.self_ty, other_ty))
+ }
+ else {
+ None
+ }
+ }
+}
+
+fn are_equal<'tcx>(cx: &LateContext<'tcx>, middle_ty: Ty<'_>, hir_ty: &rustc_hir::Ty<'_>) -> bool {
+ if_chain! {
+ if let ty::Adt(adt_def, _) = middle_ty.kind();
+ if let Some(local_did) = adt_def.did().as_local();
+ let item = cx.tcx.hir().expect_item(local_did);
+ let middle_ty_id = item.def_id.to_def_id();
+ if let TyKind::Path(QPath::Resolved(_, path)) = hir_ty.kind;
+ if let Res::Def(_, hir_ty_id) = path.res;
+
+ then {
+ hir_ty_id == middle_ty_id
+ }
+ else {
+ false
+ }
+ }
+}
--- /dev/null
- /// Should be written
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_with_context;
+use clippy_utils::ty::implements_trait;
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind, Pat, PatKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::Ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for pattern matchings that can be expressed using equality.
+ ///
+ /// ### Why is this bad?
+ ///
+ /// * It reads better and has less cognitive load because equality won't cause binding.
+ /// * It is a [Yoda condition](https://en.wikipedia.org/wiki/Yoda_conditions). Yoda conditions are widely
+ /// criticized for increasing the cognitive load of reading the code.
+ /// * Equality is a simple bool expression and can be merged with `&&` and `||` and
+ /// reuse if blocks
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// if let Some(2) = x {
+ /// do_thing();
+ /// }
+ /// ```
++ /// Use instead:
+ /// ```rust,ignore
+ /// if x == Some(2) {
+ /// do_thing();
+ /// }
+ /// ```
+ #[clippy::version = "1.57.0"]
+ pub EQUATABLE_IF_LET,
+ nursery,
+ "using pattern matching instead of equality"
+}
+
+declare_lint_pass!(PatternEquality => [EQUATABLE_IF_LET]);
+
+/// detects if pattern matches just one thing
+fn unary_pattern(pat: &Pat<'_>) -> bool {
+ fn array_rec(pats: &[Pat<'_>]) -> bool {
+ pats.iter().all(unary_pattern)
+ }
+ match &pat.kind {
+ PatKind::Slice(_, _, _) | PatKind::Range(_, _, _) | PatKind::Binding(..) | PatKind::Wild | PatKind::Or(_) => {
+ false
+ },
+ PatKind::Struct(_, a, etc) => !etc && a.iter().all(|x| unary_pattern(x.pat)),
+ PatKind::Tuple(a, etc) | PatKind::TupleStruct(_, a, etc) => !etc.is_some() && array_rec(a),
+ PatKind::Ref(x, _) | PatKind::Box(x) => unary_pattern(x),
+ PatKind::Path(_) | PatKind::Lit(_) => true,
+ }
+}
+
+fn is_structural_partial_eq<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, other: Ty<'tcx>) -> bool {
+ if let Some(def_id) = cx.tcx.lang_items().eq_trait() {
+ implements_trait(cx, ty, def_id, &[other.into()])
+ } else {
+ false
+ }
+}
+
+impl<'tcx> LateLintPass<'tcx> for PatternEquality {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
+ if_chain! {
+ if let ExprKind::Let(let_expr) = expr.kind;
+ if unary_pattern(let_expr.pat);
+ let exp_ty = cx.typeck_results().expr_ty(let_expr.init);
+ let pat_ty = cx.typeck_results().pat_ty(let_expr.pat);
+ if is_structural_partial_eq(cx, exp_ty, pat_ty);
+ then {
+
+ let mut applicability = Applicability::MachineApplicable;
+ let pat_str = match let_expr.pat.kind {
+ PatKind::Struct(..) => format!(
+ "({})",
+ snippet_with_context(cx, let_expr.pat.span, expr.span.ctxt(), "..", &mut applicability).0,
+ ),
+ _ => snippet_with_context(cx, let_expr.pat.span, expr.span.ctxt(), "..", &mut applicability).0.to_string(),
+ };
+ span_lint_and_sugg(
+ cx,
+ EQUATABLE_IF_LET,
+ expr.span,
+ "this pattern matching can be expressed using equality",
+ "try",
+ format!(
+ "{} == {}",
+ snippet_with_context(cx, let_expr.init.span, expr.span.ctxt(), "..", &mut applicability).0,
+ pat_str,
+ ),
+ applicability,
+ );
+ }
+ }
+ }
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::ty::contains_ty;
+use rustc_hir::intravisit;
+use rustc_hir::{self, AssocItemKind, Body, FnDecl, HirId, HirIdSet, Impl, ItemKind, Node};
+use rustc_infer::infer::TyCtxtInferExt;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::mir::FakeReadCause;
+use rustc_middle::ty::layout::LayoutOf;
+use rustc_middle::ty::{self, TraitRef, Ty};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+use rustc_span::symbol::kw;
+use rustc_target::spec::abi::Abi;
+use rustc_typeck::expr_use_visitor::{Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
+
+#[derive(Copy, Clone)]
+pub struct BoxedLocal {
+ pub too_large_for_stack: u64,
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `Box<T>` where an unboxed `T` would
+ /// work fine.
+ ///
+ /// ### Why is this bad?
+ /// This is an unnecessary allocation, and bad for
+ /// performance. It is only necessary to allocate if you wish to move the box
+ /// into something.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # fn foo(bar: usize) {}
- /// // Good
+ /// let x = Box::new(1);
+ /// foo(*x);
+ /// println!("{}", *x);
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # fn foo(bar: usize) {}
+ /// let x = 1;
+ /// foo(x);
+ /// println!("{}", x);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub BOXED_LOCAL,
+ perf,
+ "using `Box<T>` where unnecessary"
+}
+
+fn is_non_trait_box(ty: Ty<'_>) -> bool {
+ ty.is_box() && !ty.boxed_ty().is_trait()
+}
+
+struct EscapeDelegate<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ set: HirIdSet,
+ trait_self_ty: Option<Ty<'tcx>>,
+ too_large_for_stack: u64,
+}
+
+impl_lint_pass!(BoxedLocal => [BOXED_LOCAL]);
+
+impl<'tcx> LateLintPass<'tcx> for BoxedLocal {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ fn_kind: intravisit::FnKind<'tcx>,
+ _: &'tcx FnDecl<'_>,
+ body: &'tcx Body<'_>,
+ _: Span,
+ hir_id: HirId,
+ ) {
+ if let Some(header) = fn_kind.header() {
+ if header.abi != Abi::Rust {
+ return;
+ }
+ }
+
+ let parent_id = cx.tcx.hir().get_parent_item(hir_id);
+ let parent_node = cx.tcx.hir().find_by_def_id(parent_id);
+
+ let mut trait_self_ty = None;
+ if let Some(Node::Item(item)) = parent_node {
+ // If the method is an impl for a trait, don't warn.
+ if let ItemKind::Impl(Impl { of_trait: Some(_), .. }) = item.kind {
+ return;
+ }
+
+ // find `self` ty for this trait if relevant
+ if let ItemKind::Trait(_, _, _, _, items) = item.kind {
+ for trait_item in items {
+ if trait_item.id.hir_id() == hir_id {
+ // be sure we have `self` parameter in this function
+ if trait_item.kind == (AssocItemKind::Fn { has_self: true }) {
+ trait_self_ty = Some(
+ TraitRef::identity(cx.tcx, trait_item.id.def_id.to_def_id())
+ .self_ty()
+ .skip_binder(),
+ );
+ }
+ }
+ }
+ }
+ }
+
+ let mut v = EscapeDelegate {
+ cx,
+ set: HirIdSet::default(),
+ trait_self_ty,
+ too_large_for_stack: self.too_large_for_stack,
+ };
+
+ let fn_def_id = cx.tcx.hir().local_def_id(hir_id);
+ cx.tcx.infer_ctxt().enter(|infcx| {
+ ExprUseVisitor::new(&mut v, &infcx, fn_def_id, cx.param_env, cx.typeck_results()).consume_body(body);
+ });
+
+ for node in v.set {
+ span_lint(
+ cx,
+ BOXED_LOCAL,
+ cx.tcx.hir().span(node),
+ "local variable doesn't need to be boxed here",
+ );
+ }
+ }
+}
+
+// TODO: Replace with Map::is_argument(..) when it's fixed
+fn is_argument(map: rustc_middle::hir::map::Map<'_>, id: HirId) -> bool {
+ match map.find(id) {
+ Some(Node::Binding(_)) => (),
+ _ => return false,
+ }
+
+ matches!(map.find(map.get_parent_node(id)), Some(Node::Param(_)))
+}
+
+impl<'a, 'tcx> Delegate<'tcx> for EscapeDelegate<'a, 'tcx> {
+ fn consume(&mut self, cmt: &PlaceWithHirId<'tcx>, _: HirId) {
+ if cmt.place.projections.is_empty() {
+ if let PlaceBase::Local(lid) = cmt.place.base {
+ self.set.remove(&lid);
+ let map = &self.cx.tcx.hir();
+ if let Some(Node::Binding(_)) = map.find(cmt.hir_id) {
+ if self.set.contains(&lid) {
+ // let y = x where x is known
+ // remove x, insert y
+ self.set.insert(cmt.hir_id);
+ self.set.remove(&lid);
+ }
+ }
+ }
+ }
+ }
+
+ fn borrow(&mut self, cmt: &PlaceWithHirId<'tcx>, _: HirId, _: ty::BorrowKind) {
+ if cmt.place.projections.is_empty() {
+ if let PlaceBase::Local(lid) = cmt.place.base {
+ self.set.remove(&lid);
+ }
+ }
+ }
+
+ fn mutate(&mut self, cmt: &PlaceWithHirId<'tcx>, _: HirId) {
+ if cmt.place.projections.is_empty() {
+ let map = &self.cx.tcx.hir();
+ if is_argument(*map, cmt.hir_id) {
+ // Skip closure arguments
+ let parent_id = map.get_parent_node(cmt.hir_id);
+ if let Some(Node::Expr(..)) = map.find(map.get_parent_node(parent_id)) {
+ return;
+ }
+
+ // skip if there is a `self` parameter binding to a type
+ // that contains `Self` (i.e.: `self: Box<Self>`), see #4804
+ if let Some(trait_self_ty) = self.trait_self_ty {
+ if map.name(cmt.hir_id) == kw::SelfLower && contains_ty(cmt.place.ty(), trait_self_ty) {
+ return;
+ }
+ }
+
+ if is_non_trait_box(cmt.place.ty()) && !self.is_large_box(cmt.place.ty()) {
+ self.set.insert(cmt.hir_id);
+ }
+ }
+ }
+ }
+
+ fn fake_read(&mut self, _: &rustc_typeck::expr_use_visitor::PlaceWithHirId<'tcx>, _: FakeReadCause, _: HirId) {}
+}
+
+impl<'a, 'tcx> EscapeDelegate<'a, 'tcx> {
+ fn is_large_box(&self, ty: Ty<'tcx>) -> bool {
+ // Large types need to be boxed to avoid stack overflows.
+ if ty.is_box() {
+ self.cx.layout_of(ty.boxed_ty()).map_or(0, |l| l.size.bytes()) > self.too_large_for_stack
+ } else {
+ false
+ }
+ }
+}
--- /dev/null
- /// Bad:
+use clippy_utils::diagnostics::span_lint_and_help;
+use rustc_ast::ast::{AssocItemKind, Extern, Fn, FnSig, Impl, Item, ItemKind, Trait, Ty, TyKind};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::{sym, Span};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for excessive
+ /// use of bools in structs.
+ ///
+ /// ### Why is this bad?
+ /// Excessive bools in a struct
+ /// is often a sign that it's used as a state machine,
+ /// which is much better implemented as an enum.
+ /// If it's not the case, excessive bools usually benefit
+ /// from refactoring into two-variant enums for better
+ /// readability and API.
+ ///
+ /// ### Example
- /// Good:
+ /// ```rust
+ /// struct S {
+ /// is_pending: bool,
+ /// is_processing: bool,
+ /// is_finished: bool,
+ /// }
+ /// ```
+ ///
++ /// Use instead:
+ /// ```rust
+ /// enum S {
+ /// Pending,
+ /// Processing,
+ /// Finished,
+ /// }
+ /// ```
+ #[clippy::version = "1.43.0"]
+ pub STRUCT_EXCESSIVE_BOOLS,
+ pedantic,
+ "using too many bools in a struct"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for excessive use of
+ /// bools in function definitions.
+ ///
+ /// ### Why is this bad?
+ /// Calls to such functions
+ /// are confusing and error prone, because it's
+ /// hard to remember argument order and you have
+ /// no type system support to back you up. Using
+ /// two-variant enums instead of bools often makes
+ /// API easier to use.
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust,ignore
+ /// fn f(is_round: bool, is_hot: bool) { ... }
+ /// ```
+ ///
+ /// Good:
+ /// ```rust,ignore
+ /// enum Shape {
+ /// Round,
+ /// Spiky,
+ /// }
+ ///
+ /// enum Temperature {
+ /// Hot,
+ /// IceCold,
+ /// }
+ ///
+ /// fn f(shape: Shape, temperature: Temperature) { ... }
+ /// ```
+ #[clippy::version = "1.43.0"]
+ pub FN_PARAMS_EXCESSIVE_BOOLS,
+ pedantic,
+ "using too many bools in function parameters"
+}
+
+pub struct ExcessiveBools {
+ max_struct_bools: u64,
+ max_fn_params_bools: u64,
+}
+
+impl ExcessiveBools {
+ #[must_use]
+ pub fn new(max_struct_bools: u64, max_fn_params_bools: u64) -> Self {
+ Self {
+ max_struct_bools,
+ max_fn_params_bools,
+ }
+ }
+
+ fn check_fn_sig(&self, cx: &EarlyContext<'_>, fn_sig: &FnSig, span: Span) {
+ match fn_sig.header.ext {
+ Extern::Implicit | Extern::Explicit(_) => return,
+ Extern::None => (),
+ }
+
+ let fn_sig_bools = fn_sig
+ .decl
+ .inputs
+ .iter()
+ .filter(|param| is_bool_ty(¶m.ty))
+ .count()
+ .try_into()
+ .unwrap();
+ if self.max_fn_params_bools < fn_sig_bools {
+ span_lint_and_help(
+ cx,
+ FN_PARAMS_EXCESSIVE_BOOLS,
+ span,
+ &format!("more than {} bools in function parameters", self.max_fn_params_bools),
+ None,
+ "consider refactoring bools into two-variant enums",
+ );
+ }
+ }
+}
+
+impl_lint_pass!(ExcessiveBools => [STRUCT_EXCESSIVE_BOOLS, FN_PARAMS_EXCESSIVE_BOOLS]);
+
+fn is_bool_ty(ty: &Ty) -> bool {
+ if let TyKind::Path(None, path) = &ty.kind {
+ if let [name] = path.segments.as_slice() {
+ return name.ident.name == sym::bool;
+ }
+ }
+ false
+}
+
+impl EarlyLintPass for ExcessiveBools {
+ fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
+ if item.span.from_expansion() {
+ return;
+ }
+ match &item.kind {
+ ItemKind::Struct(variant_data, _) => {
+ if item.attrs.iter().any(|attr| attr.has_name(sym::repr)) {
+ return;
+ }
+
+ let struct_bools = variant_data
+ .fields()
+ .iter()
+ .filter(|field| is_bool_ty(&field.ty))
+ .count()
+ .try_into()
+ .unwrap();
+ if self.max_struct_bools < struct_bools {
+ span_lint_and_help(
+ cx,
+ STRUCT_EXCESSIVE_BOOLS,
+ item.span,
+ &format!("more than {} bools in a struct", self.max_struct_bools),
+ None,
+ "consider using a state machine or refactoring bools into two-variant enums",
+ );
+ }
+ },
+ ItemKind::Impl(box Impl {
+ of_trait: None, items, ..
+ })
+ | ItemKind::Trait(box Trait { items, .. }) => {
+ for item in items {
+ if let AssocItemKind::Fn(box Fn { sig, .. }) = &item.kind {
+ self.check_fn_sig(cx, sig, item.span);
+ }
+ }
+ },
+ ItemKind::Fn(box Fn { sig, .. }) => self.check_fn_sig(cx, sig, item.span),
+ _ => (),
+ }
+ }
+}
--- /dev/null
- /// // this would be clearer as `eprintln!("foo: {:?}", bar);`
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::macros::FormatArgsExpn;
+use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::{is_expn_of, match_function_call, paths};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::def::Res;
+use rustc_hir::{BindingAnnotation, Block, BlockCheckMode, Expr, ExprKind, Node, PatKind, QPath, Stmt, StmtKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `write!()` / `writeln()!` which can be
+ /// replaced with `(e)print!()` / `(e)println!()`
+ ///
+ /// ### Why is this bad?
+ /// Using `(e)println! is clearer and more concise
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::io::Write;
+ /// # let bar = "furchtbar";
+ /// writeln!(&mut std::io::stderr(), "foo: {:?}", bar).unwrap();
++ /// writeln!(&mut std::io::stdout(), "foo: {:?}", bar).unwrap();
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// # use std::io::Write;
++ /// # let bar = "furchtbar";
++ /// eprintln!("foo: {:?}", bar);
++ /// println!("foo: {:?}", bar);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EXPLICIT_WRITE,
+ complexity,
+ "using the `write!()` family of functions instead of the `print!()` family of functions, when using the latter would work"
+}
+
+declare_lint_pass!(ExplicitWrite => [EXPLICIT_WRITE]);
+
+impl<'tcx> LateLintPass<'tcx> for ExplicitWrite {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ // match call to unwrap
+ if let ExprKind::MethodCall(unwrap_fun, [write_call], _) = expr.kind;
+ if unwrap_fun.ident.name == sym::unwrap;
+ // match call to write_fmt
+ if let ExprKind::MethodCall(write_fun, [write_recv, write_arg], _) = look_in_block(cx, &write_call.kind);
+ if write_fun.ident.name == sym!(write_fmt);
+ // match calls to std::io::stdout() / std::io::stderr ()
+ if let Some(dest_name) = if match_function_call(cx, write_recv, &paths::STDOUT).is_some() {
+ Some("stdout")
+ } else if match_function_call(cx, write_recv, &paths::STDERR).is_some() {
+ Some("stderr")
+ } else {
+ None
+ };
+ if let Some(format_args) = FormatArgsExpn::parse(cx, write_arg);
+ then {
+ let calling_macro =
+ // ordering is important here, since `writeln!` uses `write!` internally
+ if is_expn_of(write_call.span, "writeln").is_some() {
+ Some("writeln")
+ } else if is_expn_of(write_call.span, "write").is_some() {
+ Some("write")
+ } else {
+ None
+ };
+ let prefix = if dest_name == "stderr" {
+ "e"
+ } else {
+ ""
+ };
+
+ // We need to remove the last trailing newline from the string because the
+ // underlying `fmt::write` function doesn't know whether `println!` or `print!` was
+ // used.
+ let (used, sugg_mac) = if let Some(macro_name) = calling_macro {
+ (
+ format!("{}!({}(), ...)", macro_name, dest_name),
+ macro_name.replace("write", "print"),
+ )
+ } else {
+ (
+ format!("{}().write_fmt(...)", dest_name),
+ "print".into(),
+ )
+ };
+ let mut applicability = Applicability::MachineApplicable;
+ let inputs_snippet = snippet_with_applicability(
+ cx,
+ format_args.inputs_span(),
+ "..",
+ &mut applicability,
+ );
+ span_lint_and_sugg(
+ cx,
+ EXPLICIT_WRITE,
+ expr.span,
+ &format!("use of `{}.unwrap()`", used),
+ "try this",
+ format!("{}{}!({})", prefix, sugg_mac, inputs_snippet),
+ applicability,
+ )
+ }
+ }
+ }
+}
+
+/// If `kind` is a block that looks like `{ let result = $expr; result }` then
+/// returns $expr. Otherwise returns `kind`.
+fn look_in_block<'tcx, 'hir>(cx: &LateContext<'tcx>, kind: &'tcx ExprKind<'hir>) -> &'tcx ExprKind<'hir> {
+ if_chain! {
+ if let ExprKind::Block(block, _label @ None) = kind;
+ if let Block {
+ stmts: [Stmt { kind: StmtKind::Local(local), .. }],
+ expr: Some(expr_end_of_block),
+ rules: BlockCheckMode::DefaultBlock,
+ ..
+ } = block;
+
+ // Find id of the local that expr_end_of_block resolves to
+ if let ExprKind::Path(QPath::Resolved(None, expr_path)) = expr_end_of_block.kind;
+ if let Res::Local(expr_res) = expr_path.res;
+ if let Some(Node::Binding(res_pat)) = cx.tcx.hir().find(expr_res);
+
+ // Find id of the local we found in the block
+ if let PatKind::Binding(BindingAnnotation::Unannotated, local_hir_id, _ident, None) = local.pat.kind;
+
+ // If those two are the same hir id
+ if res_pat.hir_id == local_hir_id;
+
+ if let Some(init) = local.init;
+ then {
+ return &init.kind;
+ }
+ }
+ kind
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::macros::{is_panic, root_macro_call_first_node};
+use clippy_utils::method_chain_args;
+use clippy_utils::ty::is_type_diagnostic_item;
+use if_chain::if_chain;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::{sym, Span};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for impls of `From<..>` that contain `panic!()` or `unwrap()`
+ ///
+ /// ### Why is this bad?
+ /// `TryFrom` should be used if there's a possibility of failure.
+ ///
+ /// ### Example
+ /// ```rust
+ /// struct Foo(i32);
+ ///
- /// // Good
+ /// impl From<String> for Foo {
+ /// fn from(s: String) -> Self {
+ /// Foo(s.parse().unwrap())
+ /// }
+ /// }
+ /// ```
+ ///
++ /// Use instead:
+ /// ```rust
+ /// struct Foo(i32);
+ ///
+ /// impl TryFrom<String> for Foo {
+ /// type Error = ();
+ /// fn try_from(s: String) -> Result<Self, Self::Error> {
+ /// if let Ok(parsed) = s.parse() {
+ /// Ok(Foo(parsed))
+ /// } else {
+ /// Err(())
+ /// }
+ /// }
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub FALLIBLE_IMPL_FROM,
+ nursery,
+ "Warn on impls of `From<..>` that contain `panic!()` or `unwrap()`"
+}
+
+declare_lint_pass!(FallibleImplFrom => [FALLIBLE_IMPL_FROM]);
+
+impl<'tcx> LateLintPass<'tcx> for FallibleImplFrom {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
+ // check for `impl From<???> for ..`
+ if_chain! {
+ if let hir::ItemKind::Impl(impl_) = &item.kind;
+ if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(item.def_id);
+ if cx.tcx.is_diagnostic_item(sym::From, impl_trait_ref.def_id);
+ then {
+ lint_impl_body(cx, item.span, impl_.items);
+ }
+ }
+ }
+}
+
+fn lint_impl_body<'tcx>(cx: &LateContext<'tcx>, impl_span: Span, impl_items: &[hir::ImplItemRef]) {
+ use rustc_hir::intravisit::{self, Visitor};
+ use rustc_hir::{Expr, ImplItemKind};
+
+ struct FindPanicUnwrap<'a, 'tcx> {
+ lcx: &'a LateContext<'tcx>,
+ typeck_results: &'tcx ty::TypeckResults<'tcx>,
+ result: Vec<Span>,
+ }
+
+ impl<'a, 'tcx> Visitor<'tcx> for FindPanicUnwrap<'a, 'tcx> {
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if let Some(macro_call) = root_macro_call_first_node(self.lcx, expr) {
+ if is_panic(self.lcx, macro_call.def_id) {
+ self.result.push(expr.span);
+ }
+ }
+
+ // check for `unwrap`
+ if let Some(arglists) = method_chain_args(expr, &["unwrap"]) {
+ let receiver_ty = self.typeck_results.expr_ty(&arglists[0][0]).peel_refs();
+ if is_type_diagnostic_item(self.lcx, receiver_ty, sym::Option)
+ || is_type_diagnostic_item(self.lcx, receiver_ty, sym::Result)
+ {
+ self.result.push(expr.span);
+ }
+ }
+
+ // and check sub-expressions
+ intravisit::walk_expr(self, expr);
+ }
+ }
+
+ for impl_item in impl_items {
+ if_chain! {
+ if impl_item.ident.name == sym::from;
+ if let ImplItemKind::Fn(_, body_id) =
+ cx.tcx.hir().impl_item(impl_item.id).kind;
+ then {
+ // check the body for `begin_panic` or `unwrap`
+ let body = cx.tcx.hir().body(body_id);
+ let mut fpu = FindPanicUnwrap {
+ lcx: cx,
+ typeck_results: cx.tcx.typeck(impl_item.id.def_id),
+ result: Vec::new(),
+ };
+ fpu.visit_expr(&body.value);
+
+ // if we've found one, lint
+ if !fpu.result.is_empty() {
+ span_lint_and_then(
+ cx,
+ FALLIBLE_IMPL_FROM,
+ impl_span,
+ "consider implementing `TryFrom` instead",
+ move |diag| {
+ diag.help(
+ "`From` is intended for infallible conversions only. \
+ Use `TryFrom` if there's a possibility for the conversion to fail");
+ diag.span_note(fpu.result, "potential failure(s)");
+ });
+ }
+ }
+ }
+ }
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::numeric_literal;
+use if_chain::if_chain;
+use rustc_ast::ast::{self, LitFloatType, LitKind};
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, FloatTy};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use std::fmt;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for float literals with a precision greater
+ /// than that supported by the underlying type.
+ ///
+ /// ### Why is this bad?
+ /// Rust will truncate the literal silently.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// let v: f32 = 0.123_456_789_9;
+ /// println!("{}", v); // 0.123_456_789
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
+ /// let v: f64 = 0.123_456_789_9;
+ /// println!("{}", v); // 0.123_456_789_9
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EXCESSIVE_PRECISION,
+ style,
+ "excessive precision for float literal"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for whole number float literals that
+ /// cannot be represented as the underlying type without loss.
+ ///
+ /// ### Why is this bad?
+ /// Rust will silently lose precision during
+ /// conversion to a float.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// let _: f32 = 16_777_217.0; // 16_777_216.0
+ ///
+ /// // Good
+ /// let _: f32 = 16_777_216.0;
+ /// let _: f64 = 16_777_217.0;
+ /// ```
+ #[clippy::version = "1.43.0"]
+ pub LOSSY_FLOAT_LITERAL,
+ restriction,
+ "lossy whole number float literals"
+}
+
+declare_lint_pass!(FloatLiteral => [EXCESSIVE_PRECISION, LOSSY_FLOAT_LITERAL]);
+
+impl<'tcx> LateLintPass<'tcx> for FloatLiteral {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
+ let ty = cx.typeck_results().expr_ty(expr);
+ if_chain! {
+ if let ty::Float(fty) = *ty.kind();
+ if let hir::ExprKind::Lit(ref lit) = expr.kind;
+ if let LitKind::Float(sym, lit_float_ty) = lit.node;
+ then {
+ let sym_str = sym.as_str();
+ let formatter = FloatFormat::new(sym_str);
+ // Try to bail out if the float is for sure fine.
+ // If its within the 2 decimal digits of being out of precision we
+ // check if the parsed representation is the same as the string
+ // since we'll need the truncated string anyway.
+ let digits = count_digits(sym_str);
+ let max = max_digits(fty);
+ let type_suffix = match lit_float_ty {
+ LitFloatType::Suffixed(ast::FloatTy::F32) => Some("f32"),
+ LitFloatType::Suffixed(ast::FloatTy::F64) => Some("f64"),
+ LitFloatType::Unsuffixed => None
+ };
+ let (is_whole, mut float_str) = match fty {
+ FloatTy::F32 => {
+ let value = sym_str.parse::<f32>().unwrap();
+
+ (value.fract() == 0.0, formatter.format(value))
+ },
+ FloatTy::F64 => {
+ let value = sym_str.parse::<f64>().unwrap();
+
+ (value.fract() == 0.0, formatter.format(value))
+ },
+ };
+
+ if is_whole && !sym_str.contains(|c| c == 'e' || c == 'E') {
+ // Normalize the literal by stripping the fractional portion
+ if sym_str.split('.').next().unwrap() != float_str {
+ // If the type suffix is missing the suggestion would be
+ // incorrectly interpreted as an integer so adding a `.0`
+ // suffix to prevent that.
+ if type_suffix.is_none() {
+ float_str.push_str(".0");
+ }
+
+ span_lint_and_sugg(
+ cx,
+ LOSSY_FLOAT_LITERAL,
+ expr.span,
+ "literal cannot be represented as the underlying type without loss of precision",
+ "consider changing the type or replacing it with",
+ numeric_literal::format(&float_str, type_suffix, true),
+ Applicability::MachineApplicable,
+ );
+ }
+ } else if digits > max as usize && float_str.len() < sym_str.len() {
+ span_lint_and_sugg(
+ cx,
+ EXCESSIVE_PRECISION,
+ expr.span,
+ "float has excessive precision",
+ "consider changing the type or truncating it to",
+ numeric_literal::format(&float_str, type_suffix, true),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ }
+ }
+}
+
+#[must_use]
+fn max_digits(fty: FloatTy) -> u32 {
+ match fty {
+ FloatTy::F32 => f32::DIGITS,
+ FloatTy::F64 => f64::DIGITS,
+ }
+}
+
+/// Counts the digits excluding leading zeros
+#[must_use]
+fn count_digits(s: &str) -> usize {
+ // Note that s does not contain the f32/64 suffix, and underscores have been stripped
+ s.chars()
+ .filter(|c| *c != '-' && *c != '.')
+ .take_while(|c| *c != 'e' && *c != 'E')
+ .fold(0, |count, c| {
+ // leading zeros
+ if c == '0' && count == 0 { count } else { count + 1 }
+ })
+}
+
+enum FloatFormat {
+ LowerExp,
+ UpperExp,
+ Normal,
+}
+impl FloatFormat {
+ #[must_use]
+ fn new(s: &str) -> Self {
+ s.chars()
+ .find_map(|x| match x {
+ 'e' => Some(Self::LowerExp),
+ 'E' => Some(Self::UpperExp),
+ _ => None,
+ })
+ .unwrap_or(Self::Normal)
+ }
+ fn format<T>(&self, f: T) -> String
+ where
+ T: fmt::UpperExp + fmt::LowerExp + fmt::Display,
+ {
+ match self {
+ Self::LowerExp => format!("{:e}", f),
+ Self::UpperExp => format!("{:E}", f),
+ Self::Normal => format!("{}", f),
+ }
+ }
+}
--- /dev/null
- /// is better expressed as
- ///
+use clippy_utils::consts::{
+ constant, constant_simple, Constant,
+ Constant::{Int, F32, F64},
+};
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::higher;
+use clippy_utils::{eq_expr_value, get_parent_expr, in_constant, numeric_literal, peel_blocks, sugg};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind, PathSegment, UnOp};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Spanned;
+
+use rustc_ast::ast;
+use std::f32::consts as f32_consts;
+use std::f64::consts as f64_consts;
+use sugg::Sugg;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Looks for floating-point expressions that
+ /// can be expressed using built-in methods to improve accuracy
+ /// at the cost of performance.
+ ///
+ /// ### Why is this bad?
+ /// Negatively impacts accuracy.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let a = 3f32;
+ /// let _ = a.powf(1.0 / 3.0);
+ /// let _ = (1.0 + a).ln();
+ /// let _ = a.exp() - 1.0;
+ /// ```
+ ///
++ /// Use instead:
+ /// ```rust
+ /// let a = 3f32;
+ /// let _ = a.cbrt();
+ /// let _ = a.ln_1p();
+ /// let _ = a.exp_m1();
+ /// ```
+ #[clippy::version = "1.43.0"]
+ pub IMPRECISE_FLOPS,
+ nursery,
+ "usage of imprecise floating point operations"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Looks for floating-point expressions that
+ /// can be expressed using built-in methods to improve both
+ /// accuracy and performance.
+ ///
+ /// ### Why is this bad?
+ /// Negatively impacts accuracy and performance.
+ ///
+ /// ### Example
+ /// ```rust
+ /// use std::f32::consts::E;
+ ///
+ /// let a = 3f32;
+ /// let _ = (2f32).powf(a);
+ /// let _ = E.powf(a);
+ /// let _ = a.powf(1.0 / 2.0);
+ /// let _ = a.log(2.0);
+ /// let _ = a.log(10.0);
+ /// let _ = a.log(E);
+ /// let _ = a.powf(2.0);
+ /// let _ = a * 2.0 + 4.0;
+ /// let _ = if a < 0.0 {
+ /// -a
+ /// } else {
+ /// a
+ /// };
+ /// let _ = if a < 0.0 {
+ /// a
+ /// } else {
+ /// -a
+ /// };
+ /// ```
+ ///
+ /// is better expressed as
+ ///
+ /// ```rust
+ /// use std::f32::consts::E;
+ ///
+ /// let a = 3f32;
+ /// let _ = a.exp2();
+ /// let _ = a.exp();
+ /// let _ = a.sqrt();
+ /// let _ = a.log2();
+ /// let _ = a.log10();
+ /// let _ = a.ln();
+ /// let _ = a.powi(2);
+ /// let _ = a.mul_add(2.0, 4.0);
+ /// let _ = a.abs();
+ /// let _ = -a.abs();
+ /// ```
+ #[clippy::version = "1.43.0"]
+ pub SUBOPTIMAL_FLOPS,
+ nursery,
+ "usage of sub-optimal floating point operations"
+}
+
+declare_lint_pass!(FloatingPointArithmetic => [
+ IMPRECISE_FLOPS,
+ SUBOPTIMAL_FLOPS
+]);
+
+// Returns the specialized log method for a given base if base is constant
+// and is one of 2, 10 and e
+fn get_specialized_log_method(cx: &LateContext<'_>, base: &Expr<'_>) -> Option<&'static str> {
+ if let Some((value, _)) = constant(cx, cx.typeck_results(), base) {
+ if F32(2.0) == value || F64(2.0) == value {
+ return Some("log2");
+ } else if F32(10.0) == value || F64(10.0) == value {
+ return Some("log10");
+ } else if F32(f32_consts::E) == value || F64(f64_consts::E) == value {
+ return Some("ln");
+ }
+ }
+
+ None
+}
+
+// Adds type suffixes and parenthesis to method receivers if necessary
+fn prepare_receiver_sugg<'a>(cx: &LateContext<'_>, mut expr: &'a Expr<'a>) -> Sugg<'a> {
+ let mut suggestion = Sugg::hir(cx, expr, "..");
+
+ if let ExprKind::Unary(UnOp::Neg, inner_expr) = &expr.kind {
+ expr = inner_expr;
+ }
+
+ if_chain! {
+ // if the expression is a float literal and it is unsuffixed then
+ // add a suffix so the suggestion is valid and unambiguous
+ if let ty::Float(float_ty) = cx.typeck_results().expr_ty(expr).kind();
+ if let ExprKind::Lit(lit) = &expr.kind;
+ if let ast::LitKind::Float(sym, ast::LitFloatType::Unsuffixed) = lit.node;
+ then {
+ let op = format!(
+ "{}{}{}",
+ suggestion,
+ // Check for float literals without numbers following the decimal
+ // separator such as `2.` and adds a trailing zero
+ if sym.as_str().ends_with('.') {
+ "0"
+ } else {
+ ""
+ },
+ float_ty.name_str()
+ ).into();
+
+ suggestion = match suggestion {
+ Sugg::MaybeParen(_) => Sugg::MaybeParen(op),
+ _ => Sugg::NonParen(op)
+ };
+ }
+ }
+
+ suggestion.maybe_par()
+}
+
+fn check_log_base(cx: &LateContext<'_>, expr: &Expr<'_>, args: &[Expr<'_>]) {
+ if let Some(method) = get_specialized_log_method(cx, &args[1]) {
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ expr.span,
+ "logarithm for bases 2, 10 and e can be computed more accurately",
+ "consider using",
+ format!("{}.{}()", Sugg::hir(cx, &args[0], ".."), method),
+ Applicability::MachineApplicable,
+ );
+ }
+}
+
+// TODO: Lint expressions of the form `(x + y).ln()` where y > 1 and
+// suggest usage of `(x + (y - 1)).ln_1p()` instead
+fn check_ln1p(cx: &LateContext<'_>, expr: &Expr<'_>, args: &[Expr<'_>]) {
+ if let ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Add, ..
+ },
+ lhs,
+ rhs,
+ ) = &args[0].kind
+ {
+ let recv = match (
+ constant(cx, cx.typeck_results(), lhs),
+ constant(cx, cx.typeck_results(), rhs),
+ ) {
+ (Some((value, _)), _) if F32(1.0) == value || F64(1.0) == value => rhs,
+ (_, Some((value, _))) if F32(1.0) == value || F64(1.0) == value => lhs,
+ _ => return,
+ };
+
+ span_lint_and_sugg(
+ cx,
+ IMPRECISE_FLOPS,
+ expr.span,
+ "ln(1 + x) can be computed more accurately",
+ "consider using",
+ format!("{}.ln_1p()", prepare_receiver_sugg(cx, recv)),
+ Applicability::MachineApplicable,
+ );
+ }
+}
+
+// Returns an integer if the float constant is a whole number and it can be
+// converted to an integer without loss of precision. For now we only check
+// ranges [-16777215, 16777216) for type f32 as whole number floats outside
+// this range are lossy and ambiguous.
+#[expect(clippy::cast_possible_truncation)]
+fn get_integer_from_float_constant(value: &Constant) -> Option<i32> {
+ match value {
+ F32(num) if num.fract() == 0.0 => {
+ if (-16_777_215.0..16_777_216.0).contains(num) {
+ Some(num.round() as i32)
+ } else {
+ None
+ }
+ },
+ F64(num) if num.fract() == 0.0 => {
+ if (-2_147_483_648.0..2_147_483_648.0).contains(num) {
+ Some(num.round() as i32)
+ } else {
+ None
+ }
+ },
+ _ => None,
+ }
+}
+
+fn check_powf(cx: &LateContext<'_>, expr: &Expr<'_>, args: &[Expr<'_>]) {
+ // Check receiver
+ if let Some((value, _)) = constant(cx, cx.typeck_results(), &args[0]) {
+ let method = if F32(f32_consts::E) == value || F64(f64_consts::E) == value {
+ "exp"
+ } else if F32(2.0) == value || F64(2.0) == value {
+ "exp2"
+ } else {
+ return;
+ };
+
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ expr.span,
+ "exponent for bases 2 and e can be computed more accurately",
+ "consider using",
+ format!("{}.{}()", prepare_receiver_sugg(cx, &args[1]), method),
+ Applicability::MachineApplicable,
+ );
+ }
+
+ // Check argument
+ if let Some((value, _)) = constant(cx, cx.typeck_results(), &args[1]) {
+ let (lint, help, suggestion) = if F32(1.0 / 2.0) == value || F64(1.0 / 2.0) == value {
+ (
+ SUBOPTIMAL_FLOPS,
+ "square-root of a number can be computed more efficiently and accurately",
+ format!("{}.sqrt()", Sugg::hir(cx, &args[0], "..")),
+ )
+ } else if F32(1.0 / 3.0) == value || F64(1.0 / 3.0) == value {
+ (
+ IMPRECISE_FLOPS,
+ "cube-root of a number can be computed more accurately",
+ format!("{}.cbrt()", Sugg::hir(cx, &args[0], "..")),
+ )
+ } else if let Some(exponent) = get_integer_from_float_constant(&value) {
+ (
+ SUBOPTIMAL_FLOPS,
+ "exponentiation with integer powers can be computed more efficiently",
+ format!(
+ "{}.powi({})",
+ Sugg::hir(cx, &args[0], ".."),
+ numeric_literal::format(&exponent.to_string(), None, false)
+ ),
+ )
+ } else {
+ return;
+ };
+
+ span_lint_and_sugg(
+ cx,
+ lint,
+ expr.span,
+ help,
+ "consider using",
+ suggestion,
+ Applicability::MachineApplicable,
+ );
+ }
+}
+
+fn check_powi(cx: &LateContext<'_>, expr: &Expr<'_>, args: &[Expr<'_>]) {
+ if let Some((value, _)) = constant(cx, cx.typeck_results(), &args[1]) {
+ if value == Int(2) {
+ if let Some(parent) = get_parent_expr(cx, expr) {
+ if let Some(grandparent) = get_parent_expr(cx, parent) {
+ if let ExprKind::MethodCall(PathSegment { ident: method_name, .. }, args, _) = grandparent.kind {
+ if method_name.as_str() == "sqrt" && detect_hypot(cx, args).is_some() {
+ return;
+ }
+ }
+ }
+
+ if let ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Add, ..
+ },
+ lhs,
+ rhs,
+ ) = parent.kind
+ {
+ let other_addend = if lhs.hir_id == expr.hir_id { rhs } else { lhs };
+
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ parent.span,
+ "multiply and add expressions can be calculated more efficiently and accurately",
+ "consider using",
+ format!(
+ "{}.mul_add({}, {})",
+ Sugg::hir(cx, &args[0], ".."),
+ Sugg::hir(cx, &args[0], ".."),
+ Sugg::hir(cx, other_addend, ".."),
+ ),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ }
+ }
+}
+
+fn detect_hypot(cx: &LateContext<'_>, args: &[Expr<'_>]) -> Option<String> {
+ if let ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Add, ..
+ },
+ add_lhs,
+ add_rhs,
+ ) = args[0].kind
+ {
+ // check if expression of the form x * x + y * y
+ if_chain! {
+ if let ExprKind::Binary(Spanned { node: BinOpKind::Mul, .. }, lmul_lhs, lmul_rhs) = add_lhs.kind;
+ if let ExprKind::Binary(Spanned { node: BinOpKind::Mul, .. }, rmul_lhs, rmul_rhs) = add_rhs.kind;
+ if eq_expr_value(cx, lmul_lhs, lmul_rhs);
+ if eq_expr_value(cx, rmul_lhs, rmul_rhs);
+ then {
+ return Some(format!("{}.hypot({})", Sugg::hir(cx, lmul_lhs, "..").maybe_par(), Sugg::hir(cx, rmul_lhs, "..")));
+ }
+ }
+
+ // check if expression of the form x.powi(2) + y.powi(2)
+ if_chain! {
+ if let ExprKind::MethodCall(
+ PathSegment { ident: lmethod_name, .. },
+ [largs_0, largs_1, ..],
+ _
+ ) = &add_lhs.kind;
+ if let ExprKind::MethodCall(
+ PathSegment { ident: rmethod_name, .. },
+ [rargs_0, rargs_1, ..],
+ _
+ ) = &add_rhs.kind;
+ if lmethod_name.as_str() == "powi" && rmethod_name.as_str() == "powi";
+ if let Some((lvalue, _)) = constant(cx, cx.typeck_results(), largs_1);
+ if let Some((rvalue, _)) = constant(cx, cx.typeck_results(), rargs_1);
+ if Int(2) == lvalue && Int(2) == rvalue;
+ then {
+ return Some(format!("{}.hypot({})", Sugg::hir(cx, largs_0, "..").maybe_par(), Sugg::hir(cx, rargs_0, "..")));
+ }
+ }
+ }
+
+ None
+}
+
+fn check_hypot(cx: &LateContext<'_>, expr: &Expr<'_>, args: &[Expr<'_>]) {
+ if let Some(message) = detect_hypot(cx, args) {
+ span_lint_and_sugg(
+ cx,
+ IMPRECISE_FLOPS,
+ expr.span,
+ "hypotenuse can be computed more accurately",
+ "consider using",
+ message,
+ Applicability::MachineApplicable,
+ );
+ }
+}
+
+// TODO: Lint expressions of the form `x.exp() - y` where y > 1
+// and suggest usage of `x.exp_m1() - (y - 1)` instead
+fn check_expm1(cx: &LateContext<'_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Binary(Spanned { node: BinOpKind::Sub, .. }, lhs, rhs) = expr.kind;
+ if cx.typeck_results().expr_ty(lhs).is_floating_point();
+ if let Some((value, _)) = constant(cx, cx.typeck_results(), rhs);
+ if F32(1.0) == value || F64(1.0) == value;
+ if let ExprKind::MethodCall(path, [self_arg, ..], _) = &lhs.kind;
+ if cx.typeck_results().expr_ty(self_arg).is_floating_point();
+ if path.ident.name.as_str() == "exp";
+ then {
+ span_lint_and_sugg(
+ cx,
+ IMPRECISE_FLOPS,
+ expr.span,
+ "(e.pow(x) - 1) can be computed more accurately",
+ "consider using",
+ format!(
+ "{}.exp_m1()",
+ Sugg::hir(cx, self_arg, "..")
+ ),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+}
+
+fn is_float_mul_expr<'a>(cx: &LateContext<'_>, expr: &'a Expr<'a>) -> Option<(&'a Expr<'a>, &'a Expr<'a>)> {
+ if_chain! {
+ if let ExprKind::Binary(Spanned { node: BinOpKind::Mul, .. }, lhs, rhs) = &expr.kind;
+ if cx.typeck_results().expr_ty(lhs).is_floating_point();
+ if cx.typeck_results().expr_ty(rhs).is_floating_point();
+ then {
+ return Some((lhs, rhs));
+ }
+ }
+
+ None
+}
+
+// TODO: Fix rust-lang/rust-clippy#4735
+fn check_mul_add(cx: &LateContext<'_>, expr: &Expr<'_>) {
+ if let ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Add, ..
+ },
+ lhs,
+ rhs,
+ ) = &expr.kind
+ {
+ if let Some(parent) = get_parent_expr(cx, expr) {
+ if let ExprKind::MethodCall(PathSegment { ident: method_name, .. }, args, _) = parent.kind {
+ if method_name.as_str() == "sqrt" && detect_hypot(cx, args).is_some() {
+ return;
+ }
+ }
+ }
+
+ let (recv, arg1, arg2) = if let Some((inner_lhs, inner_rhs)) = is_float_mul_expr(cx, lhs) {
+ (inner_lhs, inner_rhs, rhs)
+ } else if let Some((inner_lhs, inner_rhs)) = is_float_mul_expr(cx, rhs) {
+ (inner_lhs, inner_rhs, lhs)
+ } else {
+ return;
+ };
+
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ expr.span,
+ "multiply and add expressions can be calculated more efficiently and accurately",
+ "consider using",
+ format!(
+ "{}.mul_add({}, {})",
+ prepare_receiver_sugg(cx, recv),
+ Sugg::hir(cx, arg1, ".."),
+ Sugg::hir(cx, arg2, ".."),
+ ),
+ Applicability::MachineApplicable,
+ );
+ }
+}
+
+/// Returns true iff expr is an expression which tests whether or not
+/// test is positive or an expression which tests whether or not test
+/// is nonnegative.
+/// Used for check-custom-abs function below
+fn is_testing_positive(cx: &LateContext<'_>, expr: &Expr<'_>, test: &Expr<'_>) -> bool {
+ if let ExprKind::Binary(Spanned { node: op, .. }, left, right) = expr.kind {
+ match op {
+ BinOpKind::Gt | BinOpKind::Ge => is_zero(cx, right) && eq_expr_value(cx, left, test),
+ BinOpKind::Lt | BinOpKind::Le => is_zero(cx, left) && eq_expr_value(cx, right, test),
+ _ => false,
+ }
+ } else {
+ false
+ }
+}
+
+/// See [`is_testing_positive`]
+fn is_testing_negative(cx: &LateContext<'_>, expr: &Expr<'_>, test: &Expr<'_>) -> bool {
+ if let ExprKind::Binary(Spanned { node: op, .. }, left, right) = expr.kind {
+ match op {
+ BinOpKind::Gt | BinOpKind::Ge => is_zero(cx, left) && eq_expr_value(cx, right, test),
+ BinOpKind::Lt | BinOpKind::Le => is_zero(cx, right) && eq_expr_value(cx, left, test),
+ _ => false,
+ }
+ } else {
+ false
+ }
+}
+
+/// Returns true iff expr is some zero literal
+fn is_zero(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ match constant_simple(cx, cx.typeck_results(), expr) {
+ Some(Constant::Int(i)) => i == 0,
+ Some(Constant::F32(f)) => f == 0.0,
+ Some(Constant::F64(f)) => f == 0.0,
+ _ => false,
+ }
+}
+
+/// If the two expressions are negations of each other, then it returns
+/// a tuple, in which the first element is true iff expr1 is the
+/// positive expressions, and the second element is the positive
+/// one of the two expressions
+/// If the two expressions are not negations of each other, then it
+/// returns None.
+fn are_negated<'a>(cx: &LateContext<'_>, expr1: &'a Expr<'a>, expr2: &'a Expr<'a>) -> Option<(bool, &'a Expr<'a>)> {
+ if let ExprKind::Unary(UnOp::Neg, expr1_negated) = &expr1.kind {
+ if eq_expr_value(cx, expr1_negated, expr2) {
+ return Some((false, expr2));
+ }
+ }
+ if let ExprKind::Unary(UnOp::Neg, expr2_negated) = &expr2.kind {
+ if eq_expr_value(cx, expr1, expr2_negated) {
+ return Some((true, expr1));
+ }
+ }
+ None
+}
+
+fn check_custom_abs(cx: &LateContext<'_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let Some(higher::If { cond, then, r#else: Some(r#else) }) = higher::If::hir(expr);
+ let if_body_expr = peel_blocks(then);
+ let else_body_expr = peel_blocks(r#else);
+ if let Some((if_expr_positive, body)) = are_negated(cx, if_body_expr, else_body_expr);
+ then {
+ let positive_abs_sugg = (
+ "manual implementation of `abs` method",
+ format!("{}.abs()", Sugg::hir(cx, body, "..")),
+ );
+ let negative_abs_sugg = (
+ "manual implementation of negation of `abs` method",
+ format!("-{}.abs()", Sugg::hir(cx, body, "..")),
+ );
+ let sugg = if is_testing_positive(cx, cond, body) {
+ if if_expr_positive {
+ positive_abs_sugg
+ } else {
+ negative_abs_sugg
+ }
+ } else if is_testing_negative(cx, cond, body) {
+ if if_expr_positive {
+ negative_abs_sugg
+ } else {
+ positive_abs_sugg
+ }
+ } else {
+ return;
+ };
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ expr.span,
+ sugg.0,
+ "try",
+ sugg.1,
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+}
+
+fn are_same_base_logs(cx: &LateContext<'_>, expr_a: &Expr<'_>, expr_b: &Expr<'_>) -> bool {
+ if_chain! {
+ if let ExprKind::MethodCall(PathSegment { ident: method_name_a, .. }, args_a, _) = expr_a.kind;
+ if let ExprKind::MethodCall(PathSegment { ident: method_name_b, .. }, args_b, _) = expr_b.kind;
+ then {
+ return method_name_a.as_str() == method_name_b.as_str() &&
+ args_a.len() == args_b.len() &&
+ (
+ ["ln", "log2", "log10"].contains(&method_name_a.as_str()) ||
+ method_name_a.as_str() == "log" && args_a.len() == 2 && eq_expr_value(cx, &args_a[1], &args_b[1])
+ );
+ }
+ }
+
+ false
+}
+
+fn check_log_division(cx: &LateContext<'_>, expr: &Expr<'_>) {
+ // check if expression of the form x.logN() / y.logN()
+ if_chain! {
+ if let ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Div, ..
+ },
+ lhs,
+ rhs,
+ ) = &expr.kind;
+ if are_same_base_logs(cx, lhs, rhs);
+ if let ExprKind::MethodCall(_, [largs_self, ..], _) = &lhs.kind;
+ if let ExprKind::MethodCall(_, [rargs_self, ..], _) = &rhs.kind;
+ then {
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ expr.span,
+ "log base can be expressed more clearly",
+ "consider using",
+ format!("{}.log({})", Sugg::hir(cx, largs_self, ".."), Sugg::hir(cx, rargs_self, ".."),),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+}
+
+fn check_radians(cx: &LateContext<'_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Div, ..
+ },
+ div_lhs,
+ div_rhs,
+ ) = &expr.kind;
+ if let ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Mul, ..
+ },
+ mul_lhs,
+ mul_rhs,
+ ) = &div_lhs.kind;
+ if let Some((rvalue, _)) = constant(cx, cx.typeck_results(), div_rhs);
+ if let Some((lvalue, _)) = constant(cx, cx.typeck_results(), mul_rhs);
+ then {
+ // TODO: also check for constant values near PI/180 or 180/PI
+ if (F32(f32_consts::PI) == rvalue || F64(f64_consts::PI) == rvalue) &&
+ (F32(180_f32) == lvalue || F64(180_f64) == lvalue)
+ {
+ let mut proposal = format!("{}.to_degrees()", Sugg::hir(cx, mul_lhs, ".."));
+ if_chain! {
+ if let ExprKind::Lit(ref literal) = mul_lhs.kind;
+ if let ast::LitKind::Float(ref value, float_type) = literal.node;
+ if float_type == ast::LitFloatType::Unsuffixed;
+ then {
+ if value.as_str().ends_with('.') {
+ proposal = format!("{}0_f64.to_degrees()", Sugg::hir(cx, mul_lhs, ".."));
+ } else {
+ proposal = format!("{}_f64.to_degrees()", Sugg::hir(cx, mul_lhs, ".."));
+ }
+ }
+ }
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ expr.span,
+ "conversion to degrees can be done more accurately",
+ "consider using",
+ proposal,
+ Applicability::MachineApplicable,
+ );
+ } else if
+ (F32(180_f32) == rvalue || F64(180_f64) == rvalue) &&
+ (F32(f32_consts::PI) == lvalue || F64(f64_consts::PI) == lvalue)
+ {
+ let mut proposal = format!("{}.to_radians()", Sugg::hir(cx, mul_lhs, ".."));
+ if_chain! {
+ if let ExprKind::Lit(ref literal) = mul_lhs.kind;
+ if let ast::LitKind::Float(ref value, float_type) = literal.node;
+ if float_type == ast::LitFloatType::Unsuffixed;
+ then {
+ if value.as_str().ends_with('.') {
+ proposal = format!("{}0_f64.to_radians()", Sugg::hir(cx, mul_lhs, ".."));
+ } else {
+ proposal = format!("{}_f64.to_radians()", Sugg::hir(cx, mul_lhs, ".."));
+ }
+ }
+ }
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ expr.span,
+ "conversion to radians can be done more accurately",
+ "consider using",
+ proposal,
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ }
+}
+
+impl<'tcx> LateLintPass<'tcx> for FloatingPointArithmetic {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ // All of these operations are currently not const.
+ if in_constant(cx, expr.hir_id) {
+ return;
+ }
+
+ if let ExprKind::MethodCall(path, args, _) = &expr.kind {
+ let recv_ty = cx.typeck_results().expr_ty(&args[0]);
+
+ if recv_ty.is_floating_point() {
+ match path.ident.name.as_str() {
+ "ln" => check_ln1p(cx, expr, args),
+ "log" => check_log_base(cx, expr, args),
+ "powf" => check_powf(cx, expr, args),
+ "powi" => check_powi(cx, expr, args),
+ "sqrt" => check_hypot(cx, expr, args),
+ _ => {},
+ }
+ }
+ } else {
+ check_expm1(cx, expr);
+ check_mul_add(cx, expr);
+ check_custom_abs(cx, expr);
+ check_log_division(cx, expr);
+ check_radians(cx, expr);
+ }
+ }
+}
--- /dev/null
- ///
- /// // Bad
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::macros::{root_macro_call_first_node, FormatArgsExpn};
+use clippy_utils::source::{snippet_opt, snippet_with_applicability};
+use clippy_utils::sugg::Sugg;
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::kw;
+use rustc_span::{sym, BytePos, Span};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the use of `format!("string literal with no
+ /// argument")` and `format!("{}", foo)` where `foo` is a string.
+ ///
+ /// ### Why is this bad?
+ /// There is no point of doing that. `format!("foo")` can
+ /// be replaced by `"foo".to_owned()` if you really need a `String`. The even
+ /// worse `&format!("foo")` is often encountered in the wild. `format!("{}",
+ /// foo)` can be replaced by `foo.clone()` if `foo: String` or `foo.to_owned()`
+ /// if `foo: &str`.
+ ///
+ /// ### Examples
+ /// ```rust
- /// // Good
+ /// let foo = "foo";
+ /// format!("{}", foo);
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// let foo = "foo";
+ /// foo.to_owned();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub USELESS_FORMAT,
+ complexity,
+ "useless use of `format!`"
+}
+
+declare_lint_pass!(UselessFormat => [USELESS_FORMAT]);
+
+impl<'tcx> LateLintPass<'tcx> for UselessFormat {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ let (format_args, call_site) = if_chain! {
+ if let Some(macro_call) = root_macro_call_first_node(cx, expr);
+ if cx.tcx.is_diagnostic_item(sym::format_macro, macro_call.def_id);
+ if let Some(format_args) = FormatArgsExpn::find_nested(cx, expr, macro_call.expn);
+ then {
+ (format_args, macro_call.span)
+ } else {
+ return
+ }
+ };
+
+ let mut applicability = Applicability::MachineApplicable;
+ if format_args.value_args.is_empty() {
+ match *format_args.format_string_parts {
+ [] => span_useless_format_empty(cx, call_site, "String::new()".to_owned(), applicability),
+ [_] => {
+ if let Some(s_src) = snippet_opt(cx, format_args.format_string_span) {
+ // Simulate macro expansion, converting {{ and }} to { and }.
+ let s_expand = s_src.replace("{{", "{").replace("}}", "}");
+ let sugg = format!("{}.to_string()", s_expand);
+ span_useless_format(cx, call_site, sugg, applicability);
+ }
+ },
+ [..] => {},
+ }
+ } else if let [value] = *format_args.value_args {
+ if_chain! {
+ if format_args.format_string_parts == [kw::Empty];
+ if match cx.typeck_results().expr_ty(value).peel_refs().kind() {
+ ty::Adt(adt, _) => cx.tcx.is_diagnostic_item(sym::String, adt.did()),
+ ty::Str => true,
+ _ => false,
+ };
+ if let Some(args) = format_args.args();
+ if args.iter().all(|arg| arg.format_trait == sym::Display && !arg.has_string_formatting());
+ then {
+ let is_new_string = match value.kind {
+ ExprKind::Binary(..) => true,
+ ExprKind::MethodCall(path, ..) => path.ident.name.as_str() == "to_string",
+ _ => false,
+ };
+ let sugg = if format_args.format_string_span.contains(value.span) {
+ // Implicit argument. e.g. `format!("{x}")` span points to `{x}`
+ let spdata = value.span.data();
+ let span = Span::new(
+ spdata.lo + BytePos(1),
+ spdata.hi - BytePos(1),
+ spdata.ctxt,
+ spdata.parent
+ );
+ let snip = snippet_with_applicability(cx, span, "..", &mut applicability);
+ if is_new_string {
+ snip.into()
+ } else {
+ format!("{snip}.to_string()")
+ }
+ } else if is_new_string {
+ snippet_with_applicability(cx, value.span, "..", &mut applicability).into_owned()
+ } else {
+ let sugg = Sugg::hir_with_applicability(cx, value, "<arg>", &mut applicability);
+ format!("{}.to_string()", sugg.maybe_par())
+ };
+ span_useless_format(cx, call_site, sugg, applicability);
+ }
+ }
+ };
+ }
+}
+
+fn span_useless_format_empty(cx: &LateContext<'_>, span: Span, sugg: String, applicability: Applicability) {
+ span_lint_and_sugg(
+ cx,
+ USELESS_FORMAT,
+ span,
+ "useless use of `format!`",
+ "consider using `String::new()`",
+ sugg,
+ applicability,
+ );
+}
+
+fn span_useless_format(cx: &LateContext<'_>, span: Span, sugg: String, applicability: Applicability) {
+ span_lint_and_sugg(
+ cx,
+ USELESS_FORMAT,
+ span,
+ "useless use of `format!`",
+ "consider using `.to_string()`",
+ sugg,
+ applicability,
+ );
+}
--- /dev/null
- /// ```rust,ignore
- /// if foo <- 30 { // this should be `foo < -30` but looks like a different operator
- /// }
+use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_note};
+use clippy_utils::source::snippet_opt;
+use if_chain::if_chain;
+use rustc_ast::ast::{BinOpKind, Block, Expr, ExprKind, StmtKind, UnOp};
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for use of the non-existent `=*`, `=!` and `=-`
+ /// operators.
+ ///
+ /// ### Why is this bad?
+ /// This is either a typo of `*=`, `!=` or `-=` or
+ /// confusing.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// a =- 42; // confusing, should it be `a -= 42` or `a = -42`?
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub SUSPICIOUS_ASSIGNMENT_FORMATTING,
+ suspicious,
+ "suspicious formatting of `*=`, `-=` or `!=`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks the formatting of a unary operator on the right hand side
+ /// of a binary operator. It lints if there is no space between the binary and unary operators,
+ /// but there is a space between the unary and its operand.
+ ///
+ /// ### Why is this bad?
+ /// This is either a typo in the binary operator or confusing.
+ ///
+ /// ### Example
- /// if foo &&! bar { // this should be `foo && !bar` but looks like a different operator
- /// }
++ /// ```rust
++ /// # let foo = true;
++ /// # let bar = false;
++ /// // &&! looks like a different operator
++ /// if foo &&! bar {}
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # let foo = true;
++ /// # let bar = false;
++ /// if foo && !bar {}
+ /// ```
+ #[clippy::version = "1.40.0"]
+ pub SUSPICIOUS_UNARY_OP_FORMATTING,
+ suspicious,
+ "suspicious formatting of unary `-` or `!` on the RHS of a BinOp"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for formatting of `else`. It lints if the `else`
+ /// is followed immediately by a newline or the `else` seems to be missing.
+ ///
+ /// ### Why is this bad?
+ /// This is probably some refactoring remnant, even if the
+ /// code is correct, it might look confusing.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// if foo {
+ /// } { // looks like an `else` is missing here
+ /// }
+ ///
+ /// if foo {
+ /// } if bar { // looks like an `else` is missing here
+ /// }
+ ///
+ /// if foo {
+ /// } else
+ ///
+ /// { // this is the `else` block of the previous `if`, but should it be?
+ /// }
+ ///
+ /// if foo {
+ /// } else
+ ///
+ /// if bar { // this is the `else` block of the previous `if`, but should it be?
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub SUSPICIOUS_ELSE_FORMATTING,
+ suspicious,
+ "suspicious formatting of `else`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for possible missing comma in an array. It lints if
+ /// an array element is a binary operator expression and it lies on two lines.
+ ///
+ /// ### Why is this bad?
+ /// This could lead to unexpected results.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// let a = &[
+ /// -1, -2, -3 // <= no comma here
+ /// -4, -5, -6
+ /// ];
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub POSSIBLE_MISSING_COMMA,
+ correctness,
+ "possible missing comma in array"
+}
+
+declare_lint_pass!(Formatting => [
+ SUSPICIOUS_ASSIGNMENT_FORMATTING,
+ SUSPICIOUS_UNARY_OP_FORMATTING,
+ SUSPICIOUS_ELSE_FORMATTING,
+ POSSIBLE_MISSING_COMMA
+]);
+
+impl EarlyLintPass for Formatting {
+ fn check_block(&mut self, cx: &EarlyContext<'_>, block: &Block) {
+ for w in block.stmts.windows(2) {
+ if let (StmtKind::Expr(first), StmtKind::Expr(second) | StmtKind::Semi(second)) = (&w[0].kind, &w[1].kind) {
+ check_missing_else(cx, first, second);
+ }
+ }
+ }
+
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ check_assign(cx, expr);
+ check_unop(cx, expr);
+ check_else(cx, expr);
+ check_array(cx, expr);
+ }
+}
+
+/// Implementation of the `SUSPICIOUS_ASSIGNMENT_FORMATTING` lint.
+fn check_assign(cx: &EarlyContext<'_>, expr: &Expr) {
+ if let ExprKind::Assign(ref lhs, ref rhs, _) = expr.kind {
+ if !lhs.span.from_expansion() && !rhs.span.from_expansion() {
+ let eq_span = lhs.span.between(rhs.span);
+ if let ExprKind::Unary(op, ref sub_rhs) = rhs.kind {
+ if let Some(eq_snippet) = snippet_opt(cx, eq_span) {
+ let op = UnOp::to_string(op);
+ let eqop_span = lhs.span.between(sub_rhs.span);
+ if eq_snippet.ends_with('=') {
+ span_lint_and_note(
+ cx,
+ SUSPICIOUS_ASSIGNMENT_FORMATTING,
+ eqop_span,
+ &format!(
+ "this looks like you are trying to use `.. {op}= ..`, but you \
+ really are doing `.. = ({op} ..)`",
+ op = op
+ ),
+ None,
+ &format!("to remove this lint, use either `{op}=` or `= {op}`", op = op),
+ );
+ }
+ }
+ }
+ }
+ }
+}
+
+/// Implementation of the `SUSPICIOUS_UNARY_OP_FORMATTING` lint.
+fn check_unop(cx: &EarlyContext<'_>, expr: &Expr) {
+ if_chain! {
+ if let ExprKind::Binary(ref binop, ref lhs, ref rhs) = expr.kind;
+ if !lhs.span.from_expansion() && !rhs.span.from_expansion();
+ // span between BinOp LHS and RHS
+ let binop_span = lhs.span.between(rhs.span);
+ // if RHS is an UnOp
+ if let ExprKind::Unary(op, ref un_rhs) = rhs.kind;
+ // from UnOp operator to UnOp operand
+ let unop_operand_span = rhs.span.until(un_rhs.span);
+ if let Some(binop_snippet) = snippet_opt(cx, binop_span);
+ if let Some(unop_operand_snippet) = snippet_opt(cx, unop_operand_span);
+ let binop_str = BinOpKind::to_string(&binop.node);
+ // no space after BinOp operator and space after UnOp operator
+ if binop_snippet.ends_with(binop_str) && unop_operand_snippet.ends_with(' ');
+ then {
+ let unop_str = UnOp::to_string(op);
+ let eqop_span = lhs.span.between(un_rhs.span);
+ span_lint_and_help(
+ cx,
+ SUSPICIOUS_UNARY_OP_FORMATTING,
+ eqop_span,
+ &format!(
+ "by not having a space between `{binop}` and `{unop}` it looks like \
+ `{binop}{unop}` is a single operator",
+ binop = binop_str,
+ unop = unop_str
+ ),
+ None,
+ &format!(
+ "put a space between `{binop}` and `{unop}` and remove the space after `{unop}`",
+ binop = binop_str,
+ unop = unop_str
+ ),
+ );
+ }
+ }
+}
+
+/// Implementation of the `SUSPICIOUS_ELSE_FORMATTING` lint for weird `else`.
+fn check_else(cx: &EarlyContext<'_>, expr: &Expr) {
+ if_chain! {
+ if let ExprKind::If(_, then, Some(else_)) = &expr.kind;
+ if is_block(else_) || is_if(else_);
+ if !then.span.from_expansion() && !else_.span.from_expansion();
+ if !in_external_macro(cx.sess(), expr.span);
+
+ // workaround for rust-lang/rust#43081
+ if expr.span.lo().0 != 0 && expr.span.hi().0 != 0;
+
+ // this will be a span from the closing ‘}’ of the “then” block (excluding) to
+ // the “if” of the “else if” block (excluding)
+ let else_span = then.span.between(else_.span);
+
+ // the snippet should look like " else \n " with maybe comments anywhere
+ // it’s bad when there is a ‘\n’ after the “else”
+ if let Some(else_snippet) = snippet_opt(cx, else_span);
+ if let Some((pre_else, post_else)) = else_snippet.split_once("else");
+ if let Some((_, post_else_post_eol)) = post_else.split_once('\n');
+
+ then {
+ // Allow allman style braces `} \n else \n {`
+ if_chain! {
+ if is_block(else_);
+ if let Some((_, pre_else_post_eol)) = pre_else.split_once('\n');
+ // Exactly one eol before and after the else
+ if !pre_else_post_eol.contains('\n');
+ if !post_else_post_eol.contains('\n');
+ then {
+ return;
+ }
+ }
+
+ let else_desc = if is_if(else_) { "if" } else { "{..}" };
+ span_lint_and_note(
+ cx,
+ SUSPICIOUS_ELSE_FORMATTING,
+ else_span,
+ &format!("this is an `else {}` but the formatting might hide it", else_desc),
+ None,
+ &format!(
+ "to remove this lint, remove the `else` or remove the new line between \
+ `else` and `{}`",
+ else_desc,
+ ),
+ );
+ }
+ }
+}
+
+#[must_use]
+fn has_unary_equivalent(bin_op: BinOpKind) -> bool {
+ // &, *, -
+ bin_op == BinOpKind::And || bin_op == BinOpKind::Mul || bin_op == BinOpKind::Sub
+}
+
+fn indentation(cx: &EarlyContext<'_>, span: Span) -> usize {
+ cx.sess().source_map().lookup_char_pos(span.lo()).col.0
+}
+
+/// Implementation of the `POSSIBLE_MISSING_COMMA` lint for array
+fn check_array(cx: &EarlyContext<'_>, expr: &Expr) {
+ if let ExprKind::Array(ref array) = expr.kind {
+ for element in array {
+ if_chain! {
+ if let ExprKind::Binary(ref op, ref lhs, _) = element.kind;
+ if has_unary_equivalent(op.node) && lhs.span.ctxt() == op.span.ctxt();
+ let space_span = lhs.span.between(op.span);
+ if let Some(space_snippet) = snippet_opt(cx, space_span);
+ let lint_span = lhs.span.with_lo(lhs.span.hi());
+ if space_snippet.contains('\n');
+ if indentation(cx, op.span) <= indentation(cx, lhs.span);
+ then {
+ span_lint_and_note(
+ cx,
+ POSSIBLE_MISSING_COMMA,
+ lint_span,
+ "possibly missing a comma here",
+ None,
+ "to remove this lint, add a comma or write the expr in a single line",
+ );
+ }
+ }
+ }
+ }
+}
+
+fn check_missing_else(cx: &EarlyContext<'_>, first: &Expr, second: &Expr) {
+ if_chain! {
+ if !first.span.from_expansion() && !second.span.from_expansion();
+ if let ExprKind::If(cond_expr, ..) = &first.kind;
+ if is_block(second) || is_if(second);
+
+ // Proc-macros can give weird spans. Make sure this is actually an `if`.
+ if let Some(if_snip) = snippet_opt(cx, first.span.until(cond_expr.span));
+ if if_snip.starts_with("if");
+
+ // If there is a line break between the two expressions, don't lint.
+ // If there is a non-whitespace character, this span came from a proc-macro.
+ let else_span = first.span.between(second.span);
+ if let Some(else_snippet) = snippet_opt(cx, else_span);
+ if !else_snippet.chars().any(|c| c == '\n' || !c.is_whitespace());
+ then {
+ let (looks_like, next_thing) = if is_if(second) {
+ ("an `else if`", "the second `if`")
+ } else {
+ ("an `else {..}`", "the next block")
+ };
+
+ span_lint_and_note(
+ cx,
+ SUSPICIOUS_ELSE_FORMATTING,
+ else_span,
+ &format!("this looks like {} but the `else` is missing", looks_like),
+ None,
+ &format!(
+ "to remove this lint, add the missing `else` or add a new line before {}",
+ next_thing,
+ ),
+ );
+ }
+ }
+}
+
+fn is_block(expr: &Expr) -> bool {
+ matches!(expr.kind, ExprKind::Block(..))
+}
+
+/// Check if the expression is an `if` or `if let`
+fn is_if(expr: &Expr) -> bool {
+ matches!(expr.kind, ExprKind::If(..))
+}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint_and_sugg;
++use clippy_utils::source::snippet_with_applicability;
++use clippy_utils::{is_slice_of_primitives, match_def_path, paths};
++use if_chain::if_chain;
++use rustc_ast::LitKind;
++use rustc_errors::Applicability;
++use rustc_hir as hir;
++use rustc_lint::{LateContext, LateLintPass};
++use rustc_session::{declare_lint_pass, declare_tool_lint};
++use rustc_span::source_map::Spanned;
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for using `x.get(0)` instead of
++ /// `x.first()`.
++ ///
++ /// ### Why is this bad?
++ /// Using `x.first()` is easier to read and has the same
++ /// result.
++ ///
++ /// ### Example
++ /// ```rust
++ /// // Bad
++ /// let x = vec![2, 3, 5];
++ /// let first_element = x.get(0);
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// // Good
++ /// let x = vec![2, 3, 5];
++ /// let first_element = x.first();
++ /// ```
++ #[clippy::version = "1.63.0"]
++ pub GET_FIRST,
++ style,
++ "Using `x.get(0)` when `x.first()` is simpler"
++}
++declare_lint_pass!(GetFirst => [GET_FIRST]);
++
++impl<'tcx> LateLintPass<'tcx> for GetFirst {
++ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
++ if_chain! {
++ if let hir::ExprKind::MethodCall(_, [struct_calling_on, method_arg], _) = &expr.kind;
++ if let Some(expr_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
++ if match_def_path(cx, expr_def_id, &paths::SLICE_GET);
++
++ if let Some(_) = is_slice_of_primitives(cx, struct_calling_on);
++ if let hir::ExprKind::Lit(Spanned { node: LitKind::Int(0, _), .. }) = method_arg.kind;
++
++ then {
++ let mut applicability = Applicability::MachineApplicable;
++ let slice_name = snippet_with_applicability(
++ cx,
++ struct_calling_on.span, "..",
++ &mut applicability,
++ );
++ span_lint_and_sugg(
++ cx,
++ GET_FIRST,
++ expr.span,
++ &format!("accessing first element with `{0}.get(0)`", slice_name),
++ "try",
++ format!("{}.first()", slice_name),
++ applicability,
++ );
++ }
++ }
++ }
++}
--- /dev/null
- use clippy_utils::get_parent_expr;
- use clippy_utils::source::snippet;
- use rustc_hir::{BinOp, BinOpKind, Expr, ExprKind};
++use clippy_utils::consts::{constant_full_int, constant_simple, Constant, FullInt};
++use clippy_utils::diagnostics::span_lint_and_sugg;
++use clippy_utils::source::snippet_with_applicability;
++use clippy_utils::{clip, unsext};
++use rustc_errors::Applicability;
++use rustc_hir::{BinOp, BinOpKind, Expr, ExprKind, Node};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
- use clippy_utils::consts::{constant_full_int, constant_simple, Constant, FullInt};
- use clippy_utils::diagnostics::span_lint;
- use clippy_utils::{clip, unsext};
-
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for identity operations, e.g., `x + 0`.
+ ///
+ /// ### Why is this bad?
+ /// This code can be removed without changing the
+ /// meaning. So it just obscures what's going on. Delete it mercilessly.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let x = 1;
+ /// x / 1 + 0 * 1 - 0 | 0;
+ /// ```
- ///
- /// ### Known problems
- /// False negatives: `f(0 + if b { 1 } else { 2 } + 3);` is reducible to
- /// `f(if b { 1 } else { 2 } + 3);`. But the lint doesn't trigger for the code.
- /// See [#8724](https://github.com/rust-lang/rust-clippy/issues/8724)
+ #[clippy::version = "pre 1.29.0"]
+ pub IDENTITY_OP,
+ complexity,
+ "using identity operations, e.g., `x + 0` or `y / 1`"
+}
+
+declare_lint_pass!(IdentityOp => [IDENTITY_OP]);
+
+impl<'tcx> LateLintPass<'tcx> for IdentityOp {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if expr.span.from_expansion() {
+ return;
+ }
+ if let ExprKind::Binary(cmp, left, right) = &expr.kind {
+ if !is_allowed(cx, *cmp, left, right) {
+ match cmp.node {
+ BinOpKind::Add | BinOpKind::BitOr | BinOpKind::BitXor => {
- if reducible_to_right(cx, expr, right) {
- check(cx, left, 0, expr.span, right.span);
- }
- check(cx, right, 0, expr.span, left.span);
++ check(cx, left, 0, expr.span, right.span, needs_parenthesis(cx, expr, right));
++ check(cx, right, 0, expr.span, left.span, Parens::Unneeded);
+ },
+ BinOpKind::Shl | BinOpKind::Shr | BinOpKind::Sub => {
- check(cx, right, 0, expr.span, left.span);
++ check(cx, right, 0, expr.span, left.span, Parens::Unneeded);
+ },
+ BinOpKind::Mul => {
- if reducible_to_right(cx, expr, right) {
- check(cx, left, 1, expr.span, right.span);
- }
- check(cx, right, 1, expr.span, left.span);
++ check(cx, left, 1, expr.span, right.span, needs_parenthesis(cx, expr, right));
++ check(cx, right, 1, expr.span, left.span, Parens::Unneeded);
+ },
- BinOpKind::Div => check(cx, right, 1, expr.span, left.span),
++ BinOpKind::Div => check(cx, right, 1, expr.span, left.span, Parens::Unneeded),
+ BinOpKind::BitAnd => {
- if reducible_to_right(cx, expr, right) {
- check(cx, left, -1, expr.span, right.span);
- }
- check(cx, right, -1, expr.span, left.span);
- },
- BinOpKind::Rem => {
- // Don't call reducible_to_right because N % N is always reducible to 1
- check_remainder(cx, left, right, expr.span, left.span);
++ check(cx, left, -1, expr.span, right.span, needs_parenthesis(cx, expr, right));
++ check(cx, right, -1, expr.span, left.span, Parens::Unneeded);
+ },
++ BinOpKind::Rem => check_remainder(cx, left, right, expr.span, left.span),
+ _ => (),
+ }
+ }
+ }
+ }
+}
+
- /// Checks if `left op ..right` can be actually reduced to `right`
- /// e.g. `0 + if b { 1 } else { 2 } + if b { 3 } else { 4 }`
- /// cannot be reduced to `if b { 1 } else { 2 } + if b { 3 } else { 4 }`
++#[derive(Copy, Clone)]
++enum Parens {
++ Needed,
++ Unneeded,
++}
++
++/// Checks if `left op right` needs parenthesis when reduced to `right`
++/// e.g. `0 + if b { 1 } else { 2 } + if b { 3 } else { 4 }` cannot be reduced
++/// to `if b { 1 } else { 2 } + if b { 3 } else { 4 }` where the `if` could be
++/// interpreted as a statement
++///
+/// See #8724
- fn reducible_to_right(cx: &LateContext<'_>, binary: &Expr<'_>, right: &Expr<'_>) -> bool {
- if let ExprKind::If(..) | ExprKind::Match(..) | ExprKind::Block(..) | ExprKind::Loop(..) = right.kind {
- is_toplevel_binary(cx, binary)
- } else {
- true
++fn needs_parenthesis(cx: &LateContext<'_>, binary: &Expr<'_>, right: &Expr<'_>) -> Parens {
++ match right.kind {
++ ExprKind::Binary(_, lhs, _) | ExprKind::Cast(lhs, _) => {
++ // ensure we're checking against the leftmost expression of `right`
++ //
++ // ~~~ `lhs`
++ // 0 + {4} * 2
++ // ~~~~~~~ `right`
++ return needs_parenthesis(cx, binary, lhs);
++ },
++ ExprKind::If(..) | ExprKind::Match(..) | ExprKind::Block(..) | ExprKind::Loop(..) => {},
++ _ => return Parens::Unneeded,
+ }
- }
+
- fn is_toplevel_binary(cx: &LateContext<'_>, must_be_binary: &Expr<'_>) -> bool {
- if let Some(parent) = get_parent_expr(cx, must_be_binary) && let ExprKind::Binary(..) = &parent.kind {
- false
- } else {
- true
++ let mut prev_id = binary.hir_id;
++ for (_, node) in cx.tcx.hir().parent_iter(binary.hir_id) {
++ if let Node::Expr(expr) = node
++ && let ExprKind::Binary(_, lhs, _) | ExprKind::Cast(lhs, _) = expr.kind
++ && lhs.hir_id == prev_id
++ {
++ // keep going until we find a node that encompasses left of `binary`
++ prev_id = expr.hir_id;
++ continue;
++ }
++
++ match node {
++ Node::Block(_) | Node::Stmt(_) => break,
++ _ => return Parens::Unneeded,
++ };
+ }
++
++ Parens::Needed
+}
+
+fn is_allowed(cx: &LateContext<'_>, cmp: BinOp, left: &Expr<'_>, right: &Expr<'_>) -> bool {
+ // This lint applies to integers
+ !cx.typeck_results().expr_ty(left).peel_refs().is_integral()
+ || !cx.typeck_results().expr_ty(right).peel_refs().is_integral()
+ // `1 << 0` is a common pattern in bit manipulation code
+ || (cmp.node == BinOpKind::Shl
+ && constant_simple(cx, cx.typeck_results(), right) == Some(Constant::Int(0))
+ && constant_simple(cx, cx.typeck_results(), left) == Some(Constant::Int(1)))
+}
+
+fn check_remainder(cx: &LateContext<'_>, left: &Expr<'_>, right: &Expr<'_>, span: Span, arg: Span) {
+ let lhs_const = constant_full_int(cx, cx.typeck_results(), left);
+ let rhs_const = constant_full_int(cx, cx.typeck_results(), right);
+ if match (lhs_const, rhs_const) {
+ (Some(FullInt::S(lv)), Some(FullInt::S(rv))) => lv.abs() < rv.abs(),
+ (Some(FullInt::U(lv)), Some(FullInt::U(rv))) => lv < rv,
+ _ => return,
+ } {
- span_ineffective_operation(cx, span, arg);
++ span_ineffective_operation(cx, span, arg, Parens::Unneeded);
+ }
+}
+
- fn check(cx: &LateContext<'_>, e: &Expr<'_>, m: i8, span: Span, arg: Span) {
++fn check(cx: &LateContext<'_>, e: &Expr<'_>, m: i8, span: Span, arg: Span, parens: Parens) {
+ if let Some(Constant::Int(v)) = constant_simple(cx, cx.typeck_results(), e).map(Constant::peel_refs) {
+ let check = match *cx.typeck_results().expr_ty(e).peel_refs().kind() {
+ ty::Int(ity) => unsext(cx.tcx, -1_i128, ity),
+ ty::Uint(uty) => clip(cx.tcx, !0, uty),
+ _ => return,
+ };
+ if match m {
+ 0 => v == 0,
+ -1 => v == check,
+ 1 => v == 1,
+ _ => unreachable!(),
+ } {
- span_ineffective_operation(cx, span, arg);
++ span_ineffective_operation(cx, span, arg, parens);
+ }
+ }
+}
+
- fn span_ineffective_operation(cx: &LateContext<'_>, span: Span, arg: Span) {
- span_lint(
++fn span_ineffective_operation(cx: &LateContext<'_>, span: Span, arg: Span, parens: Parens) {
++ let mut applicability = Applicability::MachineApplicable;
++ let expr_snippet = snippet_with_applicability(cx, arg, "..", &mut applicability);
++
++ let suggestion = match parens {
++ Parens::Needed => format!("({expr_snippet})"),
++ Parens::Unneeded => expr_snippet.into_owned(),
++ };
++
++ span_lint_and_sugg(
+ cx,
+ IDENTITY_OP,
+ span,
- &format!(
- "the operation is ineffective. Consider reducing it to `{}`",
- snippet(cx, arg, "..")
- ),
++ "this operation has no effect",
++ "consider reducing it to",
++ suggestion,
++ applicability,
+ );
+}
--- /dev/null
- use clippy_utils::diagnostics::span_lint_and_then;
+//! lint when there is a large size difference between variants on an enum
+
- fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
+use clippy_utils::source::snippet_with_applicability;
++use clippy_utils::{diagnostics::span_lint_and_then, ty::is_copy};
+use rustc_errors::Applicability;
+use rustc_hir::{Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::layout::LayoutOf;
++use rustc_middle::ty::{Adt, Ty};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for large size differences between variants on
+ /// `enum`s.
+ ///
+ /// ### Why is this bad?
+ /// Enum size is bounded by the largest variant. Having a
+ /// large variant can penalize the memory layout of that enum.
+ ///
+ /// ### Known problems
+ /// This lint obviously cannot take the distribution of
+ /// variants in your running program into account. It is possible that the
+ /// smaller variants make up less than 1% of all instances, in which case
+ /// the overhead is negligible and the boxing is counter-productive. Always
+ /// measure the change this lint suggests.
+ ///
++ /// For types that implement `Copy`, the suggestion to `Box` a variant's
++ /// data would require removing the trait impl. The types can of course
++ /// still be `Clone`, but that is worse ergonomically. Depending on the
++ /// use case it may be possible to store the large data in an auxillary
++ /// structure (e.g. Arena or ECS).
++ ///
++ /// The lint will ignore generic types if the layout depends on the
++ /// generics, even if the size difference will be large anyway.
++ ///
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// enum Test {
+ /// A(i32),
+ /// B([i32; 8000]),
+ /// }
+ ///
+ /// // Possibly better
+ /// enum Test2 {
+ /// A(i32),
+ /// B(Box<[i32; 8000]>),
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub LARGE_ENUM_VARIANT,
+ perf,
+ "large size difference between variants on an enum"
+}
+
+#[derive(Copy, Clone)]
+pub struct LargeEnumVariant {
+ maximum_size_difference_allowed: u64,
+}
+
+impl LargeEnumVariant {
+ #[must_use]
+ pub fn new(maximum_size_difference_allowed: u64) -> Self {
+ Self {
+ maximum_size_difference_allowed,
+ }
+ }
+}
+
+struct FieldInfo {
+ ind: usize,
+ size: u64,
+}
+
+struct VariantInfo {
+ ind: usize,
+ size: u64,
+ fields_size: Vec<FieldInfo>,
+}
+
+impl_lint_pass!(LargeEnumVariant => [LARGE_ENUM_VARIANT]);
+
+impl<'tcx> LateLintPass<'tcx> for LargeEnumVariant {
- let sugg: Vec<(Span, String)> = variants_size[0]
- .fields_size
- .iter()
- .rev()
- .map_while(|val| {
- if difference > self.maximum_size_difference_allowed {
- difference = difference.saturating_sub(val.size);
- Some((
- fields[val.ind].ty.span,
- format!(
- "Box<{}>",
- snippet_with_applicability(
- cx,
- fields[val.ind].ty.span,
- "..",
- &mut applicability
- )
- .into_owned()
- ),
- ))
- } else {
- None
- }
- })
- .collect();
++ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &Item<'tcx>) {
+ if in_external_macro(cx.tcx.sess, item.span) {
+ return;
+ }
+ if let ItemKind::Enum(ref def, _) = item.kind {
+ let ty = cx.tcx.type_of(item.def_id);
+ let adt = ty.ty_adt_def().expect("already checked whether this is an enum");
+ if adt.variants().len() <= 1 {
+ return;
+ }
+ let mut variants_size: Vec<VariantInfo> = Vec::new();
+ for (i, variant) in adt.variants().iter().enumerate() {
+ let mut fields_size = Vec::new();
+ for (i, f) in variant.fields.iter().enumerate() {
+ let ty = cx.tcx.type_of(f.did);
+ // don't lint variants which have a field of generic type.
+ match cx.layout_of(ty) {
+ Ok(l) => {
+ let fsize = l.size.bytes();
+ fields_size.push(FieldInfo { ind: i, size: fsize });
+ },
+ Err(_) => {
+ return;
+ },
+ }
+ }
+ let size: u64 = fields_size.iter().map(|info| info.size).sum();
+
+ variants_size.push(VariantInfo {
+ ind: i,
+ size,
+ fields_size,
+ });
+ }
+
+ variants_size.sort_by(|a, b| (b.size.cmp(&a.size)));
+
+ let mut difference = variants_size[0].size - variants_size[1].size;
+ if difference > self.maximum_size_difference_allowed {
+ let help_text = "consider boxing the large fields to reduce the total size of the enum";
+ span_lint_and_then(
+ cx,
+ LARGE_ENUM_VARIANT,
+ def.variants[variants_size[0].ind].span,
+ "large size difference between variants",
+ |diag| {
+ diag.span_label(
+ def.variants[variants_size[0].ind].span,
+ &format!("this variant is {} bytes", variants_size[0].size),
+ );
+ diag.span_note(
+ def.variants[variants_size[1].ind].span,
+ &format!("and the second-largest variant is {} bytes:", variants_size[1].size),
+ );
+
+ let fields = def.variants[variants_size[0].ind].data.fields();
+ variants_size[0].fields_size.sort_by(|a, b| (a.size.cmp(&b.size)));
+ let mut applicability = Applicability::MaybeIncorrect;
- if !sugg.is_empty() {
- diag.multipart_suggestion(help_text, sugg, Applicability::MaybeIncorrect);
- return;
++ if is_copy(cx, ty) || maybe_copy(cx, ty) {
++ diag.span_note(
++ item.ident.span,
++ "boxing a variant would require the type no longer be `Copy`",
++ );
++ } else {
++ let sugg: Vec<(Span, String)> = variants_size[0]
++ .fields_size
++ .iter()
++ .rev()
++ .map_while(|val| {
++ if difference > self.maximum_size_difference_allowed {
++ difference = difference.saturating_sub(val.size);
++ Some((
++ fields[val.ind].ty.span,
++ format!(
++ "Box<{}>",
++ snippet_with_applicability(
++ cx,
++ fields[val.ind].ty.span,
++ "..",
++ &mut applicability
++ )
++ .into_owned()
++ ),
++ ))
++ } else {
++ None
++ }
++ })
++ .collect();
+
-
++ if !sugg.is_empty() {
++ diag.multipart_suggestion(help_text, sugg, Applicability::MaybeIncorrect);
++ return;
++ }
+ }
+ diag.span_help(def.variants[variants_size[0].ind].span, help_text);
+ },
+ );
+ }
+ }
+ }
+}
++
++fn maybe_copy<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
++ if let Adt(_def, substs) = ty.kind()
++ && substs.types().next().is_some()
++ && let Some(copy_trait) = cx.tcx.lang_items().copy_trait()
++ {
++ return cx.tcx.non_blanket_impls_for_ty(copy_trait, ty).next().is_some();
++ }
++ false
++}
--- /dev/null
- if let Some(value) = check_assign(cx, canonical_id, &*then);
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::source::snippet;
+use clippy_utils::{path_to_local_id, visitors::is_local_used};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::BindingAnnotation;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for variable declarations immediately followed by a
+ /// conditional affectation.
+ ///
+ /// ### Why is this bad?
+ /// This is not idiomatic Rust.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// let foo;
+ ///
+ /// if bar() {
+ /// foo = 42;
+ /// } else {
+ /// foo = 0;
+ /// }
+ ///
+ /// let mut baz = None;
+ ///
+ /// if bar() {
+ /// baz = Some(42);
+ /// }
+ /// ```
+ ///
+ /// should be written
+ ///
+ /// ```rust,ignore
+ /// let foo = if bar() {
+ /// 42
+ /// } else {
+ /// 0
+ /// };
+ ///
+ /// let baz = if bar() {
+ /// Some(42)
+ /// } else {
+ /// None
+ /// };
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub USELESS_LET_IF_SEQ,
+ nursery,
+ "unidiomatic `let mut` declaration followed by initialization in `if`"
+}
+
+declare_lint_pass!(LetIfSeq => [USELESS_LET_IF_SEQ]);
+
+impl<'tcx> LateLintPass<'tcx> for LetIfSeq {
+ fn check_block(&mut self, cx: &LateContext<'tcx>, block: &'tcx hir::Block<'_>) {
+ let mut it = block.stmts.iter().peekable();
+ while let Some(stmt) = it.next() {
+ if_chain! {
+ if let Some(expr) = it.peek();
+ if let hir::StmtKind::Local(local) = stmt.kind;
+ if let hir::PatKind::Binding(mode, canonical_id, ident, None) = local.pat.kind;
+ if let hir::StmtKind::Expr(if_) = expr.kind;
+ if let hir::ExprKind::If(hir::Expr { kind: hir::ExprKind::DropTemps(cond), ..}, then, else_) = if_.kind;
+ if !is_local_used(cx, *cond, canonical_id);
+ if let hir::ExprKind::Block(then, _) = then.kind;
++ if let Some(value) = check_assign(cx, canonical_id, then);
+ if !is_local_used(cx, value, canonical_id);
+ then {
+ let span = stmt.span.to(if_.span);
+
+ let has_interior_mutability = !cx.typeck_results().node_type(canonical_id).is_freeze(
+ cx.tcx.at(span),
+ cx.param_env,
+ );
+ if has_interior_mutability { return; }
+
+ let (default_multi_stmts, default) = if let Some(else_) = else_ {
+ if let hir::ExprKind::Block(else_, _) = else_.kind {
+ if let Some(default) = check_assign(cx, canonical_id, else_) {
+ (else_.stmts.len() > 1, default)
+ } else if let Some(default) = local.init {
+ (true, default)
+ } else {
+ continue;
+ }
+ } else {
+ continue;
+ }
+ } else if let Some(default) = local.init {
+ (false, default)
+ } else {
+ continue;
+ };
+
+ let mutability = match mode {
+ BindingAnnotation::RefMut | BindingAnnotation::Mutable => "<mut> ",
+ _ => "",
+ };
+
+ // FIXME: this should not suggest `mut` if we can detect that the variable is not
+ // use mutably after the `if`
+
+ let sug = format!(
+ "let {mut}{name} = if {cond} {{{then} {value} }} else {{{else} {default} }};",
+ mut=mutability,
+ name=ident.name,
+ cond=snippet(cx, cond.span, "_"),
+ then=if then.stmts.len() > 1 { " ..;" } else { "" },
+ else=if default_multi_stmts { " ..;" } else { "" },
+ value=snippet(cx, value.span, "<value>"),
+ default=snippet(cx, default.span, "<default>"),
+ );
+ span_lint_and_then(cx,
+ USELESS_LET_IF_SEQ,
+ span,
+ "`if _ { .. } else { .. }` is an expression",
+ |diag| {
+ diag.span_suggestion(
+ span,
+ "it is more idiomatic to write",
+ sug,
+ Applicability::HasPlaceholders,
+ );
+ if !mutability.is_empty() {
+ diag.note("you might not need `mut` at all");
+ }
+ });
+ }
+ }
+ }
+ }
+}
+
+fn check_assign<'tcx>(
+ cx: &LateContext<'tcx>,
+ decl: hir::HirId,
+ block: &'tcx hir::Block<'_>,
+) -> Option<&'tcx hir::Expr<'tcx>> {
+ if_chain! {
+ if block.expr.is_none();
+ if let Some(expr) = block.stmts.iter().last();
+ if let hir::StmtKind::Semi(expr) = expr.kind;
+ if let hir::ExprKind::Assign(var, value, _) = expr.kind;
+ if path_to_local_id(var, decl);
+ then {
+ if block.stmts.iter().take(block.stmts.len()-1).any(|stmt| is_local_used(cx, stmt, decl)) {
+ None
+ } else {
+ Some(value)
+ }
+ } else {
+ None
+ }
+ }
+}
--- /dev/null
- LintId::of(collapsible_match::COLLAPSIBLE_MATCH),
+// This file was generated by `cargo dev update_lints`.
+// Use that command to update this file and do not edit by hand.
+// Manual edits will be overwritten.
+
+store.register_group(true, "clippy::all", Some("clippy_all"), vec![
+ LintId::of(absurd_extreme_comparisons::ABSURD_EXTREME_COMPARISONS),
++ LintId::of(almost_complete_letter_range::ALMOST_COMPLETE_LETTER_RANGE),
+ LintId::of(approx_const::APPROX_CONSTANT),
+ LintId::of(assertions_on_constants::ASSERTIONS_ON_CONSTANTS),
+ LintId::of(assign_ops::ASSIGN_OP_PATTERN),
+ LintId::of(assign_ops::MISREFACTORED_ASSIGN_OP),
+ LintId::of(async_yields_async::ASYNC_YIELDS_ASYNC),
+ LintId::of(attrs::BLANKET_CLIPPY_RESTRICTION_LINTS),
+ LintId::of(attrs::DEPRECATED_CFG_ATTR),
+ LintId::of(attrs::DEPRECATED_SEMVER),
+ LintId::of(attrs::MISMATCHED_TARGET_OS),
+ LintId::of(attrs::USELESS_ATTRIBUTE),
+ LintId::of(await_holding_invalid::AWAIT_HOLDING_INVALID_TYPE),
+ LintId::of(await_holding_invalid::AWAIT_HOLDING_LOCK),
+ LintId::of(await_holding_invalid::AWAIT_HOLDING_REFCELL_REF),
+ LintId::of(bit_mask::BAD_BIT_MASK),
+ LintId::of(bit_mask::INEFFECTIVE_BIT_MASK),
+ LintId::of(blacklisted_name::BLACKLISTED_NAME),
+ LintId::of(blocks_in_if_conditions::BLOCKS_IN_IF_CONDITIONS),
+ LintId::of(bool_assert_comparison::BOOL_ASSERT_COMPARISON),
+ LintId::of(booleans::LOGIC_BUG),
+ LintId::of(booleans::NONMINIMAL_BOOL),
++ LintId::of(borrow_deref_ref::BORROW_DEREF_REF),
+ LintId::of(bytes_count_to_len::BYTES_COUNT_TO_LEN),
+ LintId::of(casts::CAST_ABS_TO_UNSIGNED),
+ LintId::of(casts::CAST_ENUM_CONSTRUCTOR),
+ LintId::of(casts::CAST_ENUM_TRUNCATION),
+ LintId::of(casts::CAST_REF_TO_MUT),
+ LintId::of(casts::CAST_SLICE_DIFFERENT_SIZES),
+ LintId::of(casts::CHAR_LIT_AS_U8),
+ LintId::of(casts::FN_TO_NUMERIC_CAST),
+ LintId::of(casts::FN_TO_NUMERIC_CAST_WITH_TRUNCATION),
+ LintId::of(casts::UNNECESSARY_CAST),
+ LintId::of(collapsible_if::COLLAPSIBLE_ELSE_IF),
+ LintId::of(collapsible_if::COLLAPSIBLE_IF),
- LintId::of(get_last_with_len::GET_LAST_WITH_LEN),
+ LintId::of(comparison_chain::COMPARISON_CHAIN),
+ LintId::of(copies::IFS_SAME_COND),
+ LintId::of(copies::IF_SAME_THEN_ELSE),
+ LintId::of(crate_in_macro_def::CRATE_IN_MACRO_DEF),
+ LintId::of(default::FIELD_REASSIGN_WITH_DEFAULT),
+ LintId::of(dereference::NEEDLESS_BORROW),
+ LintId::of(derivable_impls::DERIVABLE_IMPLS),
+ LintId::of(derive::DERIVE_HASH_XOR_EQ),
+ LintId::of(derive::DERIVE_ORD_XOR_PARTIAL_ORD),
+ LintId::of(derive::DERIVE_PARTIAL_EQ_WITHOUT_EQ),
+ LintId::of(disallowed_methods::DISALLOWED_METHODS),
+ LintId::of(disallowed_types::DISALLOWED_TYPES),
+ LintId::of(doc::MISSING_SAFETY_DOC),
+ LintId::of(doc::NEEDLESS_DOCTEST_MAIN),
+ LintId::of(double_comparison::DOUBLE_COMPARISONS),
+ LintId::of(double_parens::DOUBLE_PARENS),
+ LintId::of(drop_forget_ref::DROP_COPY),
+ LintId::of(drop_forget_ref::DROP_NON_DROP),
+ LintId::of(drop_forget_ref::DROP_REF),
+ LintId::of(drop_forget_ref::FORGET_COPY),
+ LintId::of(drop_forget_ref::FORGET_NON_DROP),
+ LintId::of(drop_forget_ref::FORGET_REF),
+ LintId::of(drop_forget_ref::UNDROPPED_MANUALLY_DROPS),
+ LintId::of(duplicate_mod::DUPLICATE_MOD),
+ LintId::of(duration_subsec::DURATION_SUBSEC),
+ LintId::of(entry::MAP_ENTRY),
+ LintId::of(enum_clike::ENUM_CLIKE_UNPORTABLE_VARIANT),
+ LintId::of(enum_variants::ENUM_VARIANT_NAMES),
+ LintId::of(enum_variants::MODULE_INCEPTION),
+ LintId::of(eq_op::EQ_OP),
+ LintId::of(eq_op::OP_REF),
+ LintId::of(erasing_op::ERASING_OP),
+ LintId::of(escape::BOXED_LOCAL),
+ LintId::of(eta_reduction::REDUNDANT_CLOSURE),
+ LintId::of(explicit_write::EXPLICIT_WRITE),
+ LintId::of(float_equality_without_abs::FLOAT_EQUALITY_WITHOUT_ABS),
+ LintId::of(float_literal::EXCESSIVE_PRECISION),
+ LintId::of(format::USELESS_FORMAT),
+ LintId::of(format_args::FORMAT_IN_FORMAT_ARGS),
+ LintId::of(format_args::TO_STRING_IN_FORMAT_ARGS),
+ LintId::of(format_impl::PRINT_IN_FORMAT_IMPL),
+ LintId::of(format_impl::RECURSIVE_FORMAT_IMPL),
+ LintId::of(format_push_string::FORMAT_PUSH_STRING),
+ LintId::of(formatting::POSSIBLE_MISSING_COMMA),
+ LintId::of(formatting::SUSPICIOUS_ASSIGNMENT_FORMATTING),
+ LintId::of(formatting::SUSPICIOUS_ELSE_FORMATTING),
+ LintId::of(formatting::SUSPICIOUS_UNARY_OP_FORMATTING),
+ LintId::of(from_over_into::FROM_OVER_INTO),
+ LintId::of(from_str_radix_10::FROM_STR_RADIX_10),
+ LintId::of(functions::DOUBLE_MUST_USE),
+ LintId::of(functions::MUST_USE_UNIT),
+ LintId::of(functions::NOT_UNSAFE_PTR_ARG_DEREF),
+ LintId::of(functions::RESULT_UNIT_ERR),
+ LintId::of(functions::TOO_MANY_ARGUMENTS),
- LintId::of(manual_map::MANUAL_MAP),
++ LintId::of(get_first::GET_FIRST),
+ LintId::of(identity_op::IDENTITY_OP),
+ LintId::of(if_let_mutex::IF_LET_MUTEX),
+ LintId::of(indexing_slicing::OUT_OF_BOUNDS_INDEXING),
+ LintId::of(infinite_iter::INFINITE_ITER),
+ LintId::of(inherent_to_string::INHERENT_TO_STRING),
+ LintId::of(inherent_to_string::INHERENT_TO_STRING_SHADOW_DISPLAY),
+ LintId::of(init_numbered_fields::INIT_NUMBERED_FIELDS),
+ LintId::of(inline_fn_without_body::INLINE_FN_WITHOUT_BODY),
+ LintId::of(int_plus_one::INT_PLUS_ONE),
+ LintId::of(large_const_arrays::LARGE_CONST_ARRAYS),
+ LintId::of(large_enum_variant::LARGE_ENUM_VARIANT),
+ LintId::of(len_zero::COMPARISON_TO_EMPTY),
+ LintId::of(len_zero::LEN_WITHOUT_IS_EMPTY),
+ LintId::of(len_zero::LEN_ZERO),
+ LintId::of(let_underscore::LET_UNDERSCORE_LOCK),
+ LintId::of(lifetimes::EXTRA_UNUSED_LIFETIMES),
+ LintId::of(lifetimes::NEEDLESS_LIFETIMES),
+ LintId::of(literal_representation::INCONSISTENT_DIGIT_GROUPING),
+ LintId::of(literal_representation::MISTYPED_LITERAL_SUFFIXES),
+ LintId::of(literal_representation::UNUSUAL_BYTE_GROUPINGS),
+ LintId::of(loops::EMPTY_LOOP),
+ LintId::of(loops::EXPLICIT_COUNTER_LOOP),
+ LintId::of(loops::FOR_KV_MAP),
+ LintId::of(loops::FOR_LOOPS_OVER_FALLIBLES),
+ LintId::of(loops::ITER_NEXT_LOOP),
+ LintId::of(loops::MANUAL_FLATTEN),
+ LintId::of(loops::MANUAL_MEMCPY),
+ LintId::of(loops::MISSING_SPIN_LOOP),
+ LintId::of(loops::MUT_RANGE_BOUND),
+ LintId::of(loops::NEEDLESS_COLLECT),
+ LintId::of(loops::NEEDLESS_RANGE_LOOP),
+ LintId::of(loops::NEVER_LOOP),
+ LintId::of(loops::SAME_ITEM_PUSH),
+ LintId::of(loops::SINGLE_ELEMENT_LOOP),
+ LintId::of(loops::WHILE_IMMUTABLE_CONDITION),
+ LintId::of(loops::WHILE_LET_LOOP),
+ LintId::of(loops::WHILE_LET_ON_ITERATOR),
+ LintId::of(main_recursion::MAIN_RECURSION),
+ LintId::of(manual_async_fn::MANUAL_ASYNC_FN),
+ LintId::of(manual_bits::MANUAL_BITS),
- LintId::of(manual_unwrap_or::MANUAL_UNWRAP_OR),
+ LintId::of(manual_non_exhaustive::MANUAL_NON_EXHAUSTIVE),
+ LintId::of(manual_strip::MANUAL_STRIP),
- LintId::of(match_str_case_mismatch::MATCH_STR_CASE_MISMATCH),
+ LintId::of(map_clone::MAP_CLONE),
+ LintId::of(map_unit_fn::OPTION_MAP_UNIT_FN),
+ LintId::of(map_unit_fn::RESULT_MAP_UNIT_FN),
+ LintId::of(match_result_ok::MATCH_RESULT_OK),
- LintId::of(significant_drop_in_scrutinee::SIGNIFICANT_DROP_IN_SCRUTINEE),
++ LintId::of(matches::COLLAPSIBLE_MATCH),
+ LintId::of(matches::INFALLIBLE_DESTRUCTURING_MATCH),
++ LintId::of(matches::MANUAL_MAP),
++ LintId::of(matches::MANUAL_UNWRAP_OR),
+ LintId::of(matches::MATCH_AS_REF),
+ LintId::of(matches::MATCH_LIKE_MATCHES_MACRO),
+ LintId::of(matches::MATCH_OVERLAPPING_ARM),
+ LintId::of(matches::MATCH_REF_PATS),
+ LintId::of(matches::MATCH_SINGLE_BINDING),
++ LintId::of(matches::MATCH_STR_CASE_MISMATCH),
+ LintId::of(matches::NEEDLESS_MATCH),
+ LintId::of(matches::REDUNDANT_PATTERN_MATCHING),
++ LintId::of(matches::SIGNIFICANT_DROP_IN_SCRUTINEE),
+ LintId::of(matches::SINGLE_MATCH),
+ LintId::of(matches::WILDCARD_IN_OR_PATTERNS),
+ LintId::of(mem_replace::MEM_REPLACE_OPTION_WITH_NONE),
+ LintId::of(mem_replace::MEM_REPLACE_WITH_DEFAULT),
+ LintId::of(mem_replace::MEM_REPLACE_WITH_UNINIT),
+ LintId::of(methods::BIND_INSTEAD_OF_MAP),
+ LintId::of(methods::BYTES_NTH),
+ LintId::of(methods::CHARS_LAST_CMP),
+ LintId::of(methods::CHARS_NEXT_CMP),
+ LintId::of(methods::CLONE_DOUBLE_REF),
+ LintId::of(methods::CLONE_ON_COPY),
+ LintId::of(methods::ERR_EXPECT),
+ LintId::of(methods::EXPECT_FUN_CALL),
+ LintId::of(methods::EXTEND_WITH_DRAIN),
+ LintId::of(methods::FILTER_MAP_IDENTITY),
+ LintId::of(methods::FILTER_NEXT),
+ LintId::of(methods::FLAT_MAP_IDENTITY),
++ LintId::of(methods::GET_LAST_WITH_LEN),
+ LintId::of(methods::INSPECT_FOR_EACH),
+ LintId::of(methods::INTO_ITER_ON_REF),
+ LintId::of(methods::IS_DIGIT_ASCII_RADIX),
+ LintId::of(methods::ITERATOR_STEP_BY_ZERO),
+ LintId::of(methods::ITER_CLONED_COLLECT),
+ LintId::of(methods::ITER_COUNT),
+ LintId::of(methods::ITER_NEXT_SLICE),
+ LintId::of(methods::ITER_NTH),
+ LintId::of(methods::ITER_NTH_ZERO),
+ LintId::of(methods::ITER_OVEREAGER_CLONED),
+ LintId::of(methods::ITER_SKIP_NEXT),
+ LintId::of(methods::MANUAL_FILTER_MAP),
+ LintId::of(methods::MANUAL_FIND_MAP),
+ LintId::of(methods::MANUAL_SATURATING_ARITHMETIC),
+ LintId::of(methods::MANUAL_SPLIT_ONCE),
+ LintId::of(methods::MANUAL_STR_REPEAT),
+ LintId::of(methods::MAP_COLLECT_RESULT_UNIT),
+ LintId::of(methods::MAP_FLATTEN),
+ LintId::of(methods::MAP_IDENTITY),
+ LintId::of(methods::NEEDLESS_OPTION_AS_DEREF),
+ LintId::of(methods::NEEDLESS_OPTION_TAKE),
+ LintId::of(methods::NEEDLESS_SPLITN),
+ LintId::of(methods::NEW_RET_NO_SELF),
++ LintId::of(methods::NO_EFFECT_REPLACE),
+ LintId::of(methods::OK_EXPECT),
+ LintId::of(methods::OPTION_AS_REF_DEREF),
+ LintId::of(methods::OPTION_FILTER_MAP),
+ LintId::of(methods::OPTION_MAP_OR_NONE),
+ LintId::of(methods::OR_FUN_CALL),
+ LintId::of(methods::OR_THEN_UNWRAP),
+ LintId::of(methods::RESULT_MAP_OR_INTO_OPTION),
+ LintId::of(methods::SEARCH_IS_SOME),
+ LintId::of(methods::SHOULD_IMPLEMENT_TRAIT),
+ LintId::of(methods::SINGLE_CHAR_ADD_STR),
+ LintId::of(methods::SINGLE_CHAR_PATTERN),
+ LintId::of(methods::SKIP_WHILE_NEXT),
+ LintId::of(methods::STRING_EXTEND_CHARS),
+ LintId::of(methods::SUSPICIOUS_MAP),
+ LintId::of(methods::SUSPICIOUS_SPLITN),
+ LintId::of(methods::UNINIT_ASSUMED_INIT),
+ LintId::of(methods::UNNECESSARY_FILTER_MAP),
+ LintId::of(methods::UNNECESSARY_FIND_MAP),
+ LintId::of(methods::UNNECESSARY_FOLD),
+ LintId::of(methods::UNNECESSARY_LAZY_EVALUATIONS),
+ LintId::of(methods::UNNECESSARY_TO_OWNED),
+ LintId::of(methods::UNWRAP_OR_ELSE_DEFAULT),
+ LintId::of(methods::USELESS_ASREF),
+ LintId::of(methods::WRONG_SELF_CONVENTION),
+ LintId::of(methods::ZST_OFFSET),
+ LintId::of(minmax::MIN_MAX),
+ LintId::of(misc::CMP_NAN),
+ LintId::of(misc::CMP_OWNED),
+ LintId::of(misc::MODULO_ONE),
+ LintId::of(misc::SHORT_CIRCUIT_STATEMENT),
+ LintId::of(misc::TOPLEVEL_REF_ARG),
+ LintId::of(misc::ZERO_PTR),
+ LintId::of(misc_early::BUILTIN_TYPE_SHADOW),
+ LintId::of(misc_early::DOUBLE_NEG),
+ LintId::of(misc_early::DUPLICATE_UNDERSCORE_ARGUMENT),
+ LintId::of(misc_early::MIXED_CASE_HEX_LITERALS),
+ LintId::of(misc_early::REDUNDANT_PATTERN),
+ LintId::of(misc_early::UNNEEDED_WILDCARD_PATTERN),
+ LintId::of(misc_early::ZERO_PREFIXED_LITERAL),
+ LintId::of(mixed_read_write_in_expression::DIVERGING_SUB_EXPRESSION),
+ LintId::of(mut_key::MUTABLE_KEY_TYPE),
+ LintId::of(mut_mutex_lock::MUT_MUTEX_LOCK),
+ LintId::of(mut_reference::UNNECESSARY_MUT_PASSED),
+ LintId::of(needless_arbitrary_self_type::NEEDLESS_ARBITRARY_SELF_TYPE),
+ LintId::of(needless_bool::BOOL_COMPARISON),
+ LintId::of(needless_bool::NEEDLESS_BOOL),
+ LintId::of(needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE),
+ LintId::of(needless_late_init::NEEDLESS_LATE_INIT),
+ LintId::of(needless_question_mark::NEEDLESS_QUESTION_MARK),
+ LintId::of(needless_update::NEEDLESS_UPDATE),
+ LintId::of(neg_cmp_op_on_partial_ord::NEG_CMP_OP_ON_PARTIAL_ORD),
+ LintId::of(neg_multiply::NEG_MULTIPLY),
+ LintId::of(new_without_default::NEW_WITHOUT_DEFAULT),
+ LintId::of(no_effect::NO_EFFECT),
+ LintId::of(no_effect::UNNECESSARY_OPERATION),
+ LintId::of(non_copy_const::BORROW_INTERIOR_MUTABLE_CONST),
+ LintId::of(non_copy_const::DECLARE_INTERIOR_MUTABLE_CONST),
+ LintId::of(non_expressive_names::JUST_UNDERSCORES_AND_DIGITS),
+ LintId::of(non_octal_unix_permissions::NON_OCTAL_UNIX_PERMISSIONS),
+ LintId::of(octal_escapes::OCTAL_ESCAPES),
+ LintId::of(open_options::NONSENSICAL_OPEN_OPTIONS),
+ LintId::of(option_env_unwrap::OPTION_ENV_UNWRAP),
+ LintId::of(overflow_check_conditional::OVERFLOW_CHECK_CONDITIONAL),
+ LintId::of(partialeq_ne_impl::PARTIALEQ_NE_IMPL),
+ LintId::of(precedence::PRECEDENCE),
+ LintId::of(ptr::CMP_NULL),
+ LintId::of(ptr::INVALID_NULL_PTR_USAGE),
+ LintId::of(ptr::MUT_FROM_REF),
+ LintId::of(ptr::PTR_ARG),
+ LintId::of(ptr_eq::PTR_EQ),
+ LintId::of(ptr_offset_with_cast::PTR_OFFSET_WITH_CAST),
+ LintId::of(question_mark::QUESTION_MARK),
+ LintId::of(ranges::MANUAL_RANGE_CONTAINS),
+ LintId::of(ranges::RANGE_ZIP_WITH_LEN),
+ LintId::of(ranges::REVERSED_EMPTY_RANGES),
+ LintId::of(rc_clone_in_vec_init::RC_CLONE_IN_VEC_INIT),
+ LintId::of(redundant_clone::REDUNDANT_CLONE),
+ LintId::of(redundant_closure_call::REDUNDANT_CLOSURE_CALL),
+ LintId::of(redundant_field_names::REDUNDANT_FIELD_NAMES),
+ LintId::of(redundant_slicing::REDUNDANT_SLICING),
+ LintId::of(redundant_static_lifetimes::REDUNDANT_STATIC_LIFETIMES),
+ LintId::of(reference::DEREF_ADDROF),
+ LintId::of(regex::INVALID_REGEX),
+ LintId::of(repeat_once::REPEAT_ONCE),
+ LintId::of(returns::LET_AND_RETURN),
+ LintId::of(returns::NEEDLESS_RETURN),
+ LintId::of(self_assignment::SELF_ASSIGNMENT),
+ LintId::of(self_named_constructors::SELF_NAMED_CONSTRUCTORS),
+ LintId::of(serde_api::SERDE_API_MISUSE),
+ LintId::of(single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS),
+ LintId::of(size_of_in_element_count::SIZE_OF_IN_ELEMENT_COUNT),
+ LintId::of(slow_vector_initialization::SLOW_VECTOR_INITIALIZATION),
+ LintId::of(strings::STRING_FROM_UTF8_AS_BYTES),
+ LintId::of(strings::TRIM_SPLIT_WHITESPACE),
+ LintId::of(strlen_on_c_strings::STRLEN_ON_C_STRINGS),
+ LintId::of(suspicious_trait_impl::SUSPICIOUS_ARITHMETIC_IMPL),
+ LintId::of(suspicious_trait_impl::SUSPICIOUS_OP_ASSIGN_IMPL),
+ LintId::of(swap::ALMOST_SWAPPED),
+ LintId::of(swap::MANUAL_SWAP),
++ LintId::of(swap_ptr_to_ref::SWAP_PTR_TO_REF),
+ LintId::of(tabs_in_doc_comments::TABS_IN_DOC_COMMENTS),
+ LintId::of(temporary_assignment::TEMPORARY_ASSIGNMENT),
+ LintId::of(to_digit_is_some::TO_DIGIT_IS_SOME),
+ LintId::of(transmute::CROSSPOINTER_TRANSMUTE),
+ LintId::of(transmute::TRANSMUTES_EXPRESSIBLE_AS_PTR_CASTS),
+ LintId::of(transmute::TRANSMUTE_BYTES_TO_STR),
+ LintId::of(transmute::TRANSMUTE_FLOAT_TO_INT),
+ LintId::of(transmute::TRANSMUTE_INT_TO_BOOL),
+ LintId::of(transmute::TRANSMUTE_INT_TO_CHAR),
+ LintId::of(transmute::TRANSMUTE_INT_TO_FLOAT),
+ LintId::of(transmute::TRANSMUTE_NUM_TO_BYTES),
+ LintId::of(transmute::TRANSMUTE_PTR_TO_REF),
+ LintId::of(transmute::UNSOUND_COLLECTION_TRANSMUTE),
++ LintId::of(transmute::USELESS_TRANSMUTE),
+ LintId::of(transmute::WRONG_TRANSMUTE),
+ LintId::of(transmuting_null::TRANSMUTING_NULL),
+ LintId::of(types::BORROWED_BOX),
+ LintId::of(types::BOX_COLLECTION),
+ LintId::of(types::REDUNDANT_ALLOCATION),
+ LintId::of(types::TYPE_COMPLEXITY),
+ LintId::of(types::VEC_BOX),
+ LintId::of(unicode::INVISIBLE_CHARACTERS),
+ LintId::of(uninit_vec::UNINIT_VEC),
+ LintId::of(unit_hash::UNIT_HASH),
+ LintId::of(unit_return_expecting_ord::UNIT_RETURN_EXPECTING_ORD),
+ LintId::of(unit_types::LET_UNIT_VALUE),
+ LintId::of(unit_types::UNIT_ARG),
+ LintId::of(unit_types::UNIT_CMP),
+ LintId::of(unnamed_address::FN_ADDRESS_COMPARISONS),
+ LintId::of(unnamed_address::VTABLE_ADDRESS_COMPARISONS),
+ LintId::of(unnecessary_owned_empty_strings::UNNECESSARY_OWNED_EMPTY_STRINGS),
+ LintId::of(unnecessary_sort_by::UNNECESSARY_SORT_BY),
+ LintId::of(unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME),
+ LintId::of(unused_io_amount::UNUSED_IO_AMOUNT),
+ LintId::of(unused_unit::UNUSED_UNIT),
+ LintId::of(unwrap::PANICKING_UNWRAP),
+ LintId::of(unwrap::UNNECESSARY_UNWRAP),
+ LintId::of(upper_case_acronyms::UPPER_CASE_ACRONYMS),
+ LintId::of(useless_conversion::USELESS_CONVERSION),
+ LintId::of(vec::USELESS_VEC),
+ LintId::of(vec_init_then_push::VEC_INIT_THEN_PUSH),
+ LintId::of(vec_resize_to_zero::VEC_RESIZE_TO_ZERO),
+ LintId::of(write::PRINTLN_EMPTY_STRING),
+ LintId::of(write::PRINT_LITERAL),
+ LintId::of(write::PRINT_WITH_NEWLINE),
+ LintId::of(write::WRITELN_EMPTY_STRING),
+ LintId::of(write::WRITE_LITERAL),
+ LintId::of(write::WRITE_WITH_NEWLINE),
+ LintId::of(zero_div_zero::ZERO_DIVIDED_BY_ZERO),
+])
--- /dev/null
- LintId::of(get_last_with_len::GET_LAST_WITH_LEN),
+// This file was generated by `cargo dev update_lints`.
+// Use that command to update this file and do not edit by hand.
+// Manual edits will be overwritten.
+
+store.register_group(true, "clippy::complexity", Some("clippy_complexity"), vec![
+ LintId::of(attrs::DEPRECATED_CFG_ATTR),
+ LintId::of(booleans::NONMINIMAL_BOOL),
++ LintId::of(borrow_deref_ref::BORROW_DEREF_REF),
+ LintId::of(bytes_count_to_len::BYTES_COUNT_TO_LEN),
+ LintId::of(casts::CHAR_LIT_AS_U8),
+ LintId::of(casts::UNNECESSARY_CAST),
+ LintId::of(derivable_impls::DERIVABLE_IMPLS),
+ LintId::of(double_comparison::DOUBLE_COMPARISONS),
+ LintId::of(double_parens::DOUBLE_PARENS),
+ LintId::of(duration_subsec::DURATION_SUBSEC),
+ LintId::of(explicit_write::EXPLICIT_WRITE),
+ LintId::of(format::USELESS_FORMAT),
+ LintId::of(functions::TOO_MANY_ARGUMENTS),
- LintId::of(manual_unwrap_or::MANUAL_UNWRAP_OR),
+ LintId::of(identity_op::IDENTITY_OP),
+ LintId::of(int_plus_one::INT_PLUS_ONE),
+ LintId::of(lifetimes::EXTRA_UNUSED_LIFETIMES),
+ LintId::of(lifetimes::NEEDLESS_LIFETIMES),
+ LintId::of(loops::EXPLICIT_COUNTER_LOOP),
+ LintId::of(loops::MANUAL_FLATTEN),
+ LintId::of(loops::SINGLE_ELEMENT_LOOP),
+ LintId::of(loops::WHILE_LET_LOOP),
+ LintId::of(manual_strip::MANUAL_STRIP),
+ LintId::of(map_unit_fn::OPTION_MAP_UNIT_FN),
+ LintId::of(map_unit_fn::RESULT_MAP_UNIT_FN),
++ LintId::of(matches::MANUAL_UNWRAP_OR),
+ LintId::of(matches::MATCH_AS_REF),
+ LintId::of(matches::MATCH_SINGLE_BINDING),
+ LintId::of(matches::NEEDLESS_MATCH),
+ LintId::of(matches::WILDCARD_IN_OR_PATTERNS),
+ LintId::of(methods::BIND_INSTEAD_OF_MAP),
+ LintId::of(methods::CLONE_ON_COPY),
+ LintId::of(methods::FILTER_MAP_IDENTITY),
+ LintId::of(methods::FILTER_NEXT),
+ LintId::of(methods::FLAT_MAP_IDENTITY),
++ LintId::of(methods::GET_LAST_WITH_LEN),
+ LintId::of(methods::INSPECT_FOR_EACH),
+ LintId::of(methods::ITER_COUNT),
+ LintId::of(methods::MANUAL_FILTER_MAP),
+ LintId::of(methods::MANUAL_FIND_MAP),
+ LintId::of(methods::MANUAL_SPLIT_ONCE),
+ LintId::of(methods::MAP_FLATTEN),
+ LintId::of(methods::MAP_IDENTITY),
+ LintId::of(methods::NEEDLESS_OPTION_AS_DEREF),
+ LintId::of(methods::NEEDLESS_OPTION_TAKE),
+ LintId::of(methods::NEEDLESS_SPLITN),
+ LintId::of(methods::OPTION_AS_REF_DEREF),
+ LintId::of(methods::OPTION_FILTER_MAP),
+ LintId::of(methods::OR_THEN_UNWRAP),
+ LintId::of(methods::SEARCH_IS_SOME),
+ LintId::of(methods::SKIP_WHILE_NEXT),
+ LintId::of(methods::UNNECESSARY_FILTER_MAP),
+ LintId::of(methods::UNNECESSARY_FIND_MAP),
+ LintId::of(methods::USELESS_ASREF),
+ LintId::of(misc::SHORT_CIRCUIT_STATEMENT),
+ LintId::of(misc_early::UNNEEDED_WILDCARD_PATTERN),
+ LintId::of(misc_early::ZERO_PREFIXED_LITERAL),
+ LintId::of(mixed_read_write_in_expression::DIVERGING_SUB_EXPRESSION),
+ LintId::of(needless_arbitrary_self_type::NEEDLESS_ARBITRARY_SELF_TYPE),
+ LintId::of(needless_bool::BOOL_COMPARISON),
+ LintId::of(needless_bool::NEEDLESS_BOOL),
+ LintId::of(needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE),
+ LintId::of(needless_question_mark::NEEDLESS_QUESTION_MARK),
+ LintId::of(needless_update::NEEDLESS_UPDATE),
+ LintId::of(neg_cmp_op_on_partial_ord::NEG_CMP_OP_ON_PARTIAL_ORD),
+ LintId::of(no_effect::NO_EFFECT),
+ LintId::of(no_effect::UNNECESSARY_OPERATION),
+ LintId::of(overflow_check_conditional::OVERFLOW_CHECK_CONDITIONAL),
+ LintId::of(partialeq_ne_impl::PARTIALEQ_NE_IMPL),
+ LintId::of(precedence::PRECEDENCE),
+ LintId::of(ptr_offset_with_cast::PTR_OFFSET_WITH_CAST),
+ LintId::of(ranges::RANGE_ZIP_WITH_LEN),
+ LintId::of(redundant_closure_call::REDUNDANT_CLOSURE_CALL),
+ LintId::of(redundant_slicing::REDUNDANT_SLICING),
+ LintId::of(reference::DEREF_ADDROF),
+ LintId::of(repeat_once::REPEAT_ONCE),
+ LintId::of(strings::STRING_FROM_UTF8_AS_BYTES),
+ LintId::of(strlen_on_c_strings::STRLEN_ON_C_STRINGS),
+ LintId::of(swap::MANUAL_SWAP),
+ LintId::of(temporary_assignment::TEMPORARY_ASSIGNMENT),
+ LintId::of(transmute::CROSSPOINTER_TRANSMUTE),
+ LintId::of(transmute::TRANSMUTES_EXPRESSIBLE_AS_PTR_CASTS),
+ LintId::of(transmute::TRANSMUTE_BYTES_TO_STR),
+ LintId::of(transmute::TRANSMUTE_FLOAT_TO_INT),
+ LintId::of(transmute::TRANSMUTE_INT_TO_BOOL),
+ LintId::of(transmute::TRANSMUTE_INT_TO_CHAR),
+ LintId::of(transmute::TRANSMUTE_INT_TO_FLOAT),
+ LintId::of(transmute::TRANSMUTE_NUM_TO_BYTES),
+ LintId::of(transmute::TRANSMUTE_PTR_TO_REF),
++ LintId::of(transmute::USELESS_TRANSMUTE),
+ LintId::of(types::BORROWED_BOX),
+ LintId::of(types::TYPE_COMPLEXITY),
+ LintId::of(types::VEC_BOX),
+ LintId::of(unit_types::UNIT_ARG),
+ LintId::of(unnecessary_sort_by::UNNECESSARY_SORT_BY),
+ LintId::of(unwrap::UNNECESSARY_UNWRAP),
+ LintId::of(useless_conversion::USELESS_CONVERSION),
+ LintId::of(zero_div_zero::ZERO_DIVIDED_BY_ZERO),
+])
--- /dev/null
- LintId::of(match_str_case_mismatch::MATCH_STR_CASE_MISMATCH),
+// This file was generated by `cargo dev update_lints`.
+// Use that command to update this file and do not edit by hand.
+// Manual edits will be overwritten.
+
+store.register_group(true, "clippy::correctness", Some("clippy_correctness"), vec![
+ LintId::of(absurd_extreme_comparisons::ABSURD_EXTREME_COMPARISONS),
+ LintId::of(approx_const::APPROX_CONSTANT),
+ LintId::of(async_yields_async::ASYNC_YIELDS_ASYNC),
+ LintId::of(attrs::DEPRECATED_SEMVER),
+ LintId::of(attrs::MISMATCHED_TARGET_OS),
+ LintId::of(attrs::USELESS_ATTRIBUTE),
+ LintId::of(bit_mask::BAD_BIT_MASK),
+ LintId::of(bit_mask::INEFFECTIVE_BIT_MASK),
+ LintId::of(booleans::LOGIC_BUG),
+ LintId::of(casts::CAST_REF_TO_MUT),
+ LintId::of(casts::CAST_SLICE_DIFFERENT_SIZES),
+ LintId::of(copies::IFS_SAME_COND),
+ LintId::of(copies::IF_SAME_THEN_ELSE),
+ LintId::of(derive::DERIVE_HASH_XOR_EQ),
+ LintId::of(derive::DERIVE_ORD_XOR_PARTIAL_ORD),
+ LintId::of(drop_forget_ref::DROP_COPY),
+ LintId::of(drop_forget_ref::DROP_REF),
+ LintId::of(drop_forget_ref::FORGET_COPY),
+ LintId::of(drop_forget_ref::FORGET_REF),
+ LintId::of(drop_forget_ref::UNDROPPED_MANUALLY_DROPS),
+ LintId::of(enum_clike::ENUM_CLIKE_UNPORTABLE_VARIANT),
+ LintId::of(eq_op::EQ_OP),
+ LintId::of(erasing_op::ERASING_OP),
+ LintId::of(format_impl::RECURSIVE_FORMAT_IMPL),
+ LintId::of(formatting::POSSIBLE_MISSING_COMMA),
+ LintId::of(functions::NOT_UNSAFE_PTR_ARG_DEREF),
+ LintId::of(if_let_mutex::IF_LET_MUTEX),
+ LintId::of(indexing_slicing::OUT_OF_BOUNDS_INDEXING),
+ LintId::of(infinite_iter::INFINITE_ITER),
+ LintId::of(inherent_to_string::INHERENT_TO_STRING_SHADOW_DISPLAY),
+ LintId::of(inline_fn_without_body::INLINE_FN_WITHOUT_BODY),
+ LintId::of(let_underscore::LET_UNDERSCORE_LOCK),
+ LintId::of(literal_representation::MISTYPED_LITERAL_SUFFIXES),
+ LintId::of(loops::ITER_NEXT_LOOP),
+ LintId::of(loops::NEVER_LOOP),
+ LintId::of(loops::WHILE_IMMUTABLE_CONDITION),
++ LintId::of(matches::MATCH_STR_CASE_MISMATCH),
+ LintId::of(mem_replace::MEM_REPLACE_WITH_UNINIT),
+ LintId::of(methods::CLONE_DOUBLE_REF),
+ LintId::of(methods::ITERATOR_STEP_BY_ZERO),
+ LintId::of(methods::SUSPICIOUS_SPLITN),
+ LintId::of(methods::UNINIT_ASSUMED_INIT),
+ LintId::of(methods::ZST_OFFSET),
+ LintId::of(minmax::MIN_MAX),
+ LintId::of(misc::CMP_NAN),
+ LintId::of(misc::MODULO_ONE),
+ LintId::of(non_octal_unix_permissions::NON_OCTAL_UNIX_PERMISSIONS),
+ LintId::of(open_options::NONSENSICAL_OPEN_OPTIONS),
+ LintId::of(option_env_unwrap::OPTION_ENV_UNWRAP),
+ LintId::of(ptr::INVALID_NULL_PTR_USAGE),
+ LintId::of(ptr::MUT_FROM_REF),
+ LintId::of(ranges::REVERSED_EMPTY_RANGES),
+ LintId::of(regex::INVALID_REGEX),
+ LintId::of(self_assignment::SELF_ASSIGNMENT),
+ LintId::of(serde_api::SERDE_API_MISUSE),
+ LintId::of(size_of_in_element_count::SIZE_OF_IN_ELEMENT_COUNT),
+ LintId::of(swap::ALMOST_SWAPPED),
+ LintId::of(transmute::UNSOUND_COLLECTION_TRANSMUTE),
+ LintId::of(transmute::WRONG_TRANSMUTE),
+ LintId::of(transmuting_null::TRANSMUTING_NULL),
+ LintId::of(unicode::INVISIBLE_CHARACTERS),
+ LintId::of(uninit_vec::UNINIT_VEC),
+ LintId::of(unit_hash::UNIT_HASH),
+ LintId::of(unit_return_expecting_ord::UNIT_RETURN_EXPECTING_ORD),
+ LintId::of(unit_types::UNIT_CMP),
+ LintId::of(unnamed_address::FN_ADDRESS_COMPARISONS),
+ LintId::of(unnamed_address::VTABLE_ADDRESS_COMPARISONS),
+ LintId::of(unused_io_amount::UNUSED_IO_AMOUNT),
+ LintId::of(unwrap::PANICKING_UNWRAP),
+ LintId::of(vec_resize_to_zero::VEC_RESIZE_TO_ZERO),
+])
--- /dev/null
- arithmetic::FLOAT_ARITHMETIC,
- arithmetic::INTEGER_ARITHMETIC,
+// This file was generated by `cargo dev update_lints`.
+// Use that command to update this file and do not edit by hand.
+// Manual edits will be overwritten.
+
+store.register_lints(&[
+ #[cfg(feature = "internal")]
+ utils::internal_lints::CLIPPY_LINTS_INTERNAL,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::COLLAPSIBLE_SPAN_LINT_CALLS,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::COMPILER_LINT_FUNCTIONS,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::DEFAULT_LINT,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::IF_CHAIN_STYLE,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::INTERNING_DEFINED_SYMBOL,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::INVALID_CLIPPY_VERSION_ATTRIBUTE,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::INVALID_PATHS,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::LINT_WITHOUT_LINT_PASS,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::MATCH_TYPE_ON_DIAGNOSTIC_ITEM,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::MISSING_CLIPPY_VERSION_ATTRIBUTE,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::MISSING_MSRV_ATTR_IMPL,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::OUTER_EXPN_EXPN_DATA,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::PRODUCE_ICE,
+ #[cfg(feature = "internal")]
+ utils::internal_lints::UNNECESSARY_SYMBOL_STR,
+ absurd_extreme_comparisons::ABSURD_EXTREME_COMPARISONS,
++ almost_complete_letter_range::ALMOST_COMPLETE_LETTER_RANGE,
+ approx_const::APPROX_CONSTANT,
- collapsible_match::COLLAPSIBLE_MATCH,
+ as_conversions::AS_CONVERSIONS,
++ as_underscore::AS_UNDERSCORE,
+ asm_syntax::INLINE_ASM_X86_ATT_SYNTAX,
+ asm_syntax::INLINE_ASM_X86_INTEL_SYNTAX,
+ assertions_on_constants::ASSERTIONS_ON_CONSTANTS,
+ assign_ops::ASSIGN_OP_PATTERN,
+ assign_ops::MISREFACTORED_ASSIGN_OP,
+ async_yields_async::ASYNC_YIELDS_ASYNC,
+ attrs::ALLOW_ATTRIBUTES_WITHOUT_REASON,
+ attrs::BLANKET_CLIPPY_RESTRICTION_LINTS,
+ attrs::DEPRECATED_CFG_ATTR,
+ attrs::DEPRECATED_SEMVER,
+ attrs::EMPTY_LINE_AFTER_OUTER_ATTR,
+ attrs::INLINE_ALWAYS,
+ attrs::MISMATCHED_TARGET_OS,
+ attrs::USELESS_ATTRIBUTE,
+ await_holding_invalid::AWAIT_HOLDING_INVALID_TYPE,
+ await_holding_invalid::AWAIT_HOLDING_LOCK,
+ await_holding_invalid::AWAIT_HOLDING_REFCELL_REF,
+ bit_mask::BAD_BIT_MASK,
+ bit_mask::INEFFECTIVE_BIT_MASK,
+ bit_mask::VERBOSE_BIT_MASK,
+ blacklisted_name::BLACKLISTED_NAME,
+ blocks_in_if_conditions::BLOCKS_IN_IF_CONDITIONS,
+ bool_assert_comparison::BOOL_ASSERT_COMPARISON,
+ booleans::LOGIC_BUG,
+ booleans::NONMINIMAL_BOOL,
+ borrow_as_ptr::BORROW_AS_PTR,
++ borrow_deref_ref::BORROW_DEREF_REF,
+ bytecount::NAIVE_BYTECOUNT,
+ bytes_count_to_len::BYTES_COUNT_TO_LEN,
+ cargo::CARGO_COMMON_METADATA,
+ cargo::MULTIPLE_CRATE_VERSIONS,
+ cargo::NEGATIVE_FEATURE_NAMES,
+ cargo::REDUNDANT_FEATURE_NAMES,
+ cargo::WILDCARD_DEPENDENCIES,
+ case_sensitive_file_extension_comparisons::CASE_SENSITIVE_FILE_EXTENSION_COMPARISONS,
+ casts::CAST_ABS_TO_UNSIGNED,
+ casts::CAST_ENUM_CONSTRUCTOR,
+ casts::CAST_ENUM_TRUNCATION,
+ casts::CAST_LOSSLESS,
+ casts::CAST_POSSIBLE_TRUNCATION,
+ casts::CAST_POSSIBLE_WRAP,
+ casts::CAST_PRECISION_LOSS,
+ casts::CAST_PTR_ALIGNMENT,
+ casts::CAST_REF_TO_MUT,
+ casts::CAST_SIGN_LOSS,
+ casts::CAST_SLICE_DIFFERENT_SIZES,
+ casts::CHAR_LIT_AS_U8,
+ casts::FN_TO_NUMERIC_CAST,
+ casts::FN_TO_NUMERIC_CAST_ANY,
+ casts::FN_TO_NUMERIC_CAST_WITH_TRUNCATION,
+ casts::PTR_AS_PTR,
+ casts::UNNECESSARY_CAST,
+ checked_conversions::CHECKED_CONVERSIONS,
+ cognitive_complexity::COGNITIVE_COMPLEXITY,
+ collapsible_if::COLLAPSIBLE_ELSE_IF,
+ collapsible_if::COLLAPSIBLE_IF,
- get_last_with_len::GET_LAST_WITH_LEN,
+ comparison_chain::COMPARISON_CHAIN,
+ copies::BRANCHES_SHARING_CODE,
+ copies::IFS_SAME_COND,
+ copies::IF_SAME_THEN_ELSE,
+ copies::SAME_FUNCTIONS_IN_IF_CONDITION,
+ copy_iterator::COPY_ITERATOR,
+ crate_in_macro_def::CRATE_IN_MACRO_DEF,
+ create_dir::CREATE_DIR,
+ dbg_macro::DBG_MACRO,
+ default::DEFAULT_TRAIT_ACCESS,
+ default::FIELD_REASSIGN_WITH_DEFAULT,
+ default_numeric_fallback::DEFAULT_NUMERIC_FALLBACK,
+ default_union_representation::DEFAULT_UNION_REPRESENTATION,
+ dereference::EXPLICIT_DEREF_METHODS,
+ dereference::NEEDLESS_BORROW,
+ dereference::REF_BINDING_TO_REFERENCE,
+ derivable_impls::DERIVABLE_IMPLS,
+ derive::DERIVE_HASH_XOR_EQ,
+ derive::DERIVE_ORD_XOR_PARTIAL_ORD,
+ derive::DERIVE_PARTIAL_EQ_WITHOUT_EQ,
+ derive::EXPL_IMPL_CLONE_ON_COPY,
+ derive::UNSAFE_DERIVE_DESERIALIZE,
+ disallowed_methods::DISALLOWED_METHODS,
+ disallowed_script_idents::DISALLOWED_SCRIPT_IDENTS,
+ disallowed_types::DISALLOWED_TYPES,
+ doc::DOC_MARKDOWN,
+ doc::MISSING_ERRORS_DOC,
+ doc::MISSING_PANICS_DOC,
+ doc::MISSING_SAFETY_DOC,
+ doc::NEEDLESS_DOCTEST_MAIN,
++ doc_link_with_quotes::DOC_LINK_WITH_QUOTES,
+ double_comparison::DOUBLE_COMPARISONS,
+ double_parens::DOUBLE_PARENS,
+ drop_forget_ref::DROP_COPY,
+ drop_forget_ref::DROP_NON_DROP,
+ drop_forget_ref::DROP_REF,
+ drop_forget_ref::FORGET_COPY,
+ drop_forget_ref::FORGET_NON_DROP,
+ drop_forget_ref::FORGET_REF,
+ drop_forget_ref::UNDROPPED_MANUALLY_DROPS,
+ duplicate_mod::DUPLICATE_MOD,
+ duration_subsec::DURATION_SUBSEC,
+ else_if_without_else::ELSE_IF_WITHOUT_ELSE,
+ empty_drop::EMPTY_DROP,
+ empty_enum::EMPTY_ENUM,
+ empty_structs_with_brackets::EMPTY_STRUCTS_WITH_BRACKETS,
+ entry::MAP_ENTRY,
+ enum_clike::ENUM_CLIKE_UNPORTABLE_VARIANT,
+ enum_variants::ENUM_VARIANT_NAMES,
+ enum_variants::MODULE_INCEPTION,
+ enum_variants::MODULE_NAME_REPETITIONS,
+ eq_op::EQ_OP,
+ eq_op::OP_REF,
+ equatable_if_let::EQUATABLE_IF_LET,
+ erasing_op::ERASING_OP,
+ escape::BOXED_LOCAL,
+ eta_reduction::REDUNDANT_CLOSURE,
+ eta_reduction::REDUNDANT_CLOSURE_FOR_METHOD_CALLS,
+ excessive_bools::FN_PARAMS_EXCESSIVE_BOOLS,
+ excessive_bools::STRUCT_EXCESSIVE_BOOLS,
+ exhaustive_items::EXHAUSTIVE_ENUMS,
+ exhaustive_items::EXHAUSTIVE_STRUCTS,
+ exit::EXIT,
+ explicit_write::EXPLICIT_WRITE,
+ fallible_impl_from::FALLIBLE_IMPL_FROM,
+ float_equality_without_abs::FLOAT_EQUALITY_WITHOUT_ABS,
+ float_literal::EXCESSIVE_PRECISION,
+ float_literal::LOSSY_FLOAT_LITERAL,
+ floating_point_arithmetic::IMPRECISE_FLOPS,
+ floating_point_arithmetic::SUBOPTIMAL_FLOPS,
+ format::USELESS_FORMAT,
+ format_args::FORMAT_IN_FORMAT_ARGS,
+ format_args::TO_STRING_IN_FORMAT_ARGS,
+ format_impl::PRINT_IN_FORMAT_IMPL,
+ format_impl::RECURSIVE_FORMAT_IMPL,
+ format_push_string::FORMAT_PUSH_STRING,
+ formatting::POSSIBLE_MISSING_COMMA,
+ formatting::SUSPICIOUS_ASSIGNMENT_FORMATTING,
+ formatting::SUSPICIOUS_ELSE_FORMATTING,
+ formatting::SUSPICIOUS_UNARY_OP_FORMATTING,
+ from_over_into::FROM_OVER_INTO,
+ from_str_radix_10::FROM_STR_RADIX_10,
+ functions::DOUBLE_MUST_USE,
+ functions::MUST_USE_CANDIDATE,
+ functions::MUST_USE_UNIT,
+ functions::NOT_UNSAFE_PTR_ARG_DEREF,
+ functions::RESULT_UNIT_ERR,
+ functions::TOO_MANY_ARGUMENTS,
+ functions::TOO_MANY_LINES,
+ future_not_send::FUTURE_NOT_SEND,
- manual_map::MANUAL_MAP,
++ get_first::GET_FIRST,
+ identity_op::IDENTITY_OP,
+ if_let_mutex::IF_LET_MUTEX,
+ if_not_else::IF_NOT_ELSE,
+ if_then_some_else_none::IF_THEN_SOME_ELSE_NONE,
+ implicit_hasher::IMPLICIT_HASHER,
+ implicit_return::IMPLICIT_RETURN,
+ implicit_saturating_sub::IMPLICIT_SATURATING_SUB,
+ inconsistent_struct_constructor::INCONSISTENT_STRUCT_CONSTRUCTOR,
+ index_refutable_slice::INDEX_REFUTABLE_SLICE,
+ indexing_slicing::INDEXING_SLICING,
+ indexing_slicing::OUT_OF_BOUNDS_INDEXING,
+ infinite_iter::INFINITE_ITER,
+ infinite_iter::MAYBE_INFINITE_ITER,
+ inherent_impl::MULTIPLE_INHERENT_IMPL,
+ inherent_to_string::INHERENT_TO_STRING,
+ inherent_to_string::INHERENT_TO_STRING_SHADOW_DISPLAY,
+ init_numbered_fields::INIT_NUMBERED_FIELDS,
+ inline_fn_without_body::INLINE_FN_WITHOUT_BODY,
+ int_plus_one::INT_PLUS_ONE,
+ integer_division::INTEGER_DIVISION,
+ invalid_upcast_comparisons::INVALID_UPCAST_COMPARISONS,
+ items_after_statements::ITEMS_AFTER_STATEMENTS,
+ iter_not_returning_iterator::ITER_NOT_RETURNING_ITERATOR,
+ large_const_arrays::LARGE_CONST_ARRAYS,
+ large_enum_variant::LARGE_ENUM_VARIANT,
+ large_include_file::LARGE_INCLUDE_FILE,
+ large_stack_arrays::LARGE_STACK_ARRAYS,
+ len_zero::COMPARISON_TO_EMPTY,
+ len_zero::LEN_WITHOUT_IS_EMPTY,
+ len_zero::LEN_ZERO,
+ let_if_seq::USELESS_LET_IF_SEQ,
+ let_underscore::LET_UNDERSCORE_DROP,
+ let_underscore::LET_UNDERSCORE_LOCK,
+ let_underscore::LET_UNDERSCORE_MUST_USE,
+ lifetimes::EXTRA_UNUSED_LIFETIMES,
+ lifetimes::NEEDLESS_LIFETIMES,
+ literal_representation::DECIMAL_LITERAL_REPRESENTATION,
+ literal_representation::INCONSISTENT_DIGIT_GROUPING,
+ literal_representation::LARGE_DIGIT_GROUPS,
+ literal_representation::MISTYPED_LITERAL_SUFFIXES,
+ literal_representation::UNREADABLE_LITERAL,
+ literal_representation::UNUSUAL_BYTE_GROUPINGS,
+ loops::EMPTY_LOOP,
+ loops::EXPLICIT_COUNTER_LOOP,
+ loops::EXPLICIT_INTO_ITER_LOOP,
+ loops::EXPLICIT_ITER_LOOP,
+ loops::FOR_KV_MAP,
+ loops::FOR_LOOPS_OVER_FALLIBLES,
+ loops::ITER_NEXT_LOOP,
+ loops::MANUAL_FLATTEN,
+ loops::MANUAL_MEMCPY,
+ loops::MISSING_SPIN_LOOP,
+ loops::MUT_RANGE_BOUND,
+ loops::NEEDLESS_COLLECT,
+ loops::NEEDLESS_RANGE_LOOP,
+ loops::NEVER_LOOP,
+ loops::SAME_ITEM_PUSH,
+ loops::SINGLE_ELEMENT_LOOP,
+ loops::WHILE_IMMUTABLE_CONDITION,
+ loops::WHILE_LET_LOOP,
+ loops::WHILE_LET_ON_ITERATOR,
+ macro_use::MACRO_USE_IMPORTS,
+ main_recursion::MAIN_RECURSION,
+ manual_assert::MANUAL_ASSERT,
+ manual_async_fn::MANUAL_ASYNC_FN,
+ manual_bits::MANUAL_BITS,
- manual_unwrap_or::MANUAL_UNWRAP_OR,
+ manual_non_exhaustive::MANUAL_NON_EXHAUSTIVE,
+ manual_ok_or::MANUAL_OK_OR,
+ manual_strip::MANUAL_STRIP,
- match_on_vec_items::MATCH_ON_VEC_ITEMS,
+ map_clone::MAP_CLONE,
+ map_err_ignore::MAP_ERR_IGNORE,
+ map_unit_fn::OPTION_MAP_UNIT_FN,
+ map_unit_fn::RESULT_MAP_UNIT_FN,
- match_str_case_mismatch::MATCH_STR_CASE_MISMATCH,
+ match_result_ok::MATCH_RESULT_OK,
- significant_drop_in_scrutinee::SIGNIFICANT_DROP_IN_SCRUTINEE,
++ matches::COLLAPSIBLE_MATCH,
+ matches::INFALLIBLE_DESTRUCTURING_MATCH,
++ matches::MANUAL_MAP,
++ matches::MANUAL_UNWRAP_OR,
+ matches::MATCH_AS_REF,
+ matches::MATCH_BOOL,
+ matches::MATCH_LIKE_MATCHES_MACRO,
++ matches::MATCH_ON_VEC_ITEMS,
+ matches::MATCH_OVERLAPPING_ARM,
+ matches::MATCH_REF_PATS,
+ matches::MATCH_SAME_ARMS,
+ matches::MATCH_SINGLE_BINDING,
++ matches::MATCH_STR_CASE_MISMATCH,
+ matches::MATCH_WILDCARD_FOR_SINGLE_VARIANTS,
+ matches::MATCH_WILD_ERR_ARM,
+ matches::NEEDLESS_MATCH,
+ matches::REDUNDANT_PATTERN_MATCHING,
+ matches::REST_PAT_IN_FULLY_BOUND_STRUCTS,
++ matches::SIGNIFICANT_DROP_IN_SCRUTINEE,
+ matches::SINGLE_MATCH,
+ matches::SINGLE_MATCH_ELSE,
++ matches::TRY_ERR,
+ matches::WILDCARD_ENUM_MATCH_ARM,
+ matches::WILDCARD_IN_OR_PATTERNS,
+ mem_forget::MEM_FORGET,
+ mem_replace::MEM_REPLACE_OPTION_WITH_NONE,
+ mem_replace::MEM_REPLACE_WITH_DEFAULT,
+ mem_replace::MEM_REPLACE_WITH_UNINIT,
+ methods::BIND_INSTEAD_OF_MAP,
+ methods::BYTES_NTH,
+ methods::CHARS_LAST_CMP,
+ methods::CHARS_NEXT_CMP,
+ methods::CLONED_INSTEAD_OF_COPIED,
+ methods::CLONE_DOUBLE_REF,
+ methods::CLONE_ON_COPY,
+ methods::CLONE_ON_REF_PTR,
+ methods::ERR_EXPECT,
+ methods::EXPECT_FUN_CALL,
+ methods::EXPECT_USED,
+ methods::EXTEND_WITH_DRAIN,
+ methods::FILETYPE_IS_FILE,
+ methods::FILTER_MAP_IDENTITY,
+ methods::FILTER_MAP_NEXT,
+ methods::FILTER_NEXT,
+ methods::FLAT_MAP_IDENTITY,
+ methods::FLAT_MAP_OPTION,
+ methods::FROM_ITER_INSTEAD_OF_COLLECT,
++ methods::GET_LAST_WITH_LEN,
+ methods::GET_UNWRAP,
+ methods::IMPLICIT_CLONE,
+ methods::INEFFICIENT_TO_STRING,
+ methods::INSPECT_FOR_EACH,
+ methods::INTO_ITER_ON_REF,
+ methods::IS_DIGIT_ASCII_RADIX,
+ methods::ITERATOR_STEP_BY_ZERO,
+ methods::ITER_CLONED_COLLECT,
+ methods::ITER_COUNT,
+ methods::ITER_NEXT_SLICE,
+ methods::ITER_NTH,
+ methods::ITER_NTH_ZERO,
+ methods::ITER_OVEREAGER_CLONED,
+ methods::ITER_SKIP_NEXT,
+ methods::ITER_WITH_DRAIN,
+ methods::MANUAL_FILTER_MAP,
+ methods::MANUAL_FIND_MAP,
+ methods::MANUAL_SATURATING_ARITHMETIC,
+ methods::MANUAL_SPLIT_ONCE,
+ methods::MANUAL_STR_REPEAT,
+ methods::MAP_COLLECT_RESULT_UNIT,
+ methods::MAP_FLATTEN,
+ methods::MAP_IDENTITY,
+ methods::MAP_UNWRAP_OR,
+ methods::NEEDLESS_OPTION_AS_DEREF,
+ methods::NEEDLESS_OPTION_TAKE,
+ methods::NEEDLESS_SPLITN,
+ methods::NEW_RET_NO_SELF,
++ methods::NO_EFFECT_REPLACE,
+ methods::OK_EXPECT,
+ methods::OPTION_AS_REF_DEREF,
+ methods::OPTION_FILTER_MAP,
+ methods::OPTION_MAP_OR_NONE,
+ methods::OR_FUN_CALL,
+ methods::OR_THEN_UNWRAP,
+ methods::RESULT_MAP_OR_INTO_OPTION,
+ methods::SEARCH_IS_SOME,
+ methods::SHOULD_IMPLEMENT_TRAIT,
+ methods::SINGLE_CHAR_ADD_STR,
+ methods::SINGLE_CHAR_PATTERN,
+ methods::SKIP_WHILE_NEXT,
+ methods::STRING_EXTEND_CHARS,
+ methods::SUSPICIOUS_MAP,
+ methods::SUSPICIOUS_SPLITN,
+ methods::UNINIT_ASSUMED_INIT,
+ methods::UNNECESSARY_FILTER_MAP,
+ methods::UNNECESSARY_FIND_MAP,
+ methods::UNNECESSARY_FOLD,
+ methods::UNNECESSARY_JOIN,
+ methods::UNNECESSARY_LAZY_EVALUATIONS,
+ methods::UNNECESSARY_TO_OWNED,
+ methods::UNWRAP_OR_ELSE_DEFAULT,
+ methods::UNWRAP_USED,
+ methods::USELESS_ASREF,
+ methods::WRONG_SELF_CONVENTION,
+ methods::ZST_OFFSET,
+ minmax::MIN_MAX,
+ misc::CMP_NAN,
+ misc::CMP_OWNED,
+ misc::FLOAT_CMP,
+ misc::FLOAT_CMP_CONST,
+ misc::MODULO_ONE,
+ misc::SHORT_CIRCUIT_STATEMENT,
+ misc::TOPLEVEL_REF_ARG,
+ misc::USED_UNDERSCORE_BINDING,
+ misc::ZERO_PTR,
+ misc_early::BUILTIN_TYPE_SHADOW,
+ misc_early::DOUBLE_NEG,
+ misc_early::DUPLICATE_UNDERSCORE_ARGUMENT,
+ misc_early::MIXED_CASE_HEX_LITERALS,
+ misc_early::REDUNDANT_PATTERN,
+ misc_early::SEPARATED_LITERAL_SUFFIX,
+ misc_early::UNNEEDED_FIELD_PATTERN,
+ misc_early::UNNEEDED_WILDCARD_PATTERN,
+ misc_early::UNSEPARATED_LITERAL_SUFFIX,
+ misc_early::ZERO_PREFIXED_LITERAL,
++ mismatching_type_param_order::MISMATCHING_TYPE_PARAM_ORDER,
+ missing_const_for_fn::MISSING_CONST_FOR_FN,
+ missing_doc::MISSING_DOCS_IN_PRIVATE_ITEMS,
+ missing_enforced_import_rename::MISSING_ENFORCED_IMPORT_RENAMES,
+ missing_inline::MISSING_INLINE_IN_PUBLIC_ITEMS,
+ mixed_read_write_in_expression::DIVERGING_SUB_EXPRESSION,
+ mixed_read_write_in_expression::MIXED_READ_WRITE_IN_EXPRESSION,
+ module_style::MOD_MODULE_FILES,
+ module_style::SELF_NAMED_MODULE_FILES,
+ modulo_arithmetic::MODULO_ARITHMETIC,
+ mut_key::MUTABLE_KEY_TYPE,
+ mut_mut::MUT_MUT,
+ mut_mutex_lock::MUT_MUTEX_LOCK,
+ mut_reference::UNNECESSARY_MUT_PASSED,
+ mutable_debug_assertion::DEBUG_ASSERT_WITH_MUT_CALL,
+ mutex_atomic::MUTEX_ATOMIC,
+ mutex_atomic::MUTEX_INTEGER,
+ needless_arbitrary_self_type::NEEDLESS_ARBITRARY_SELF_TYPE,
+ needless_bitwise_bool::NEEDLESS_BITWISE_BOOL,
+ needless_bool::BOOL_COMPARISON,
+ needless_bool::NEEDLESS_BOOL,
+ needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE,
+ needless_continue::NEEDLESS_CONTINUE,
+ needless_for_each::NEEDLESS_FOR_EACH,
+ needless_late_init::NEEDLESS_LATE_INIT,
+ needless_pass_by_value::NEEDLESS_PASS_BY_VALUE,
+ needless_question_mark::NEEDLESS_QUESTION_MARK,
+ needless_update::NEEDLESS_UPDATE,
+ neg_cmp_op_on_partial_ord::NEG_CMP_OP_ON_PARTIAL_ORD,
+ neg_multiply::NEG_MULTIPLY,
+ new_without_default::NEW_WITHOUT_DEFAULT,
+ no_effect::NO_EFFECT,
+ no_effect::NO_EFFECT_UNDERSCORE_BINDING,
+ no_effect::UNNECESSARY_OPERATION,
+ non_copy_const::BORROW_INTERIOR_MUTABLE_CONST,
+ non_copy_const::DECLARE_INTERIOR_MUTABLE_CONST,
+ non_expressive_names::JUST_UNDERSCORES_AND_DIGITS,
+ non_expressive_names::MANY_SINGLE_CHAR_NAMES,
+ non_expressive_names::SIMILAR_NAMES,
+ non_octal_unix_permissions::NON_OCTAL_UNIX_PERMISSIONS,
+ non_send_fields_in_send_ty::NON_SEND_FIELDS_IN_SEND_TY,
+ nonstandard_macro_braces::NONSTANDARD_MACRO_BRACES,
++ numeric_arithmetic::FLOAT_ARITHMETIC,
++ numeric_arithmetic::INTEGER_ARITHMETIC,
+ octal_escapes::OCTAL_ESCAPES,
+ only_used_in_recursion::ONLY_USED_IN_RECURSION,
+ open_options::NONSENSICAL_OPEN_OPTIONS,
+ option_env_unwrap::OPTION_ENV_UNWRAP,
+ option_if_let_else::OPTION_IF_LET_ELSE,
+ overflow_check_conditional::OVERFLOW_CHECK_CONDITIONAL,
+ panic_in_result_fn::PANIC_IN_RESULT_FN,
+ panic_unimplemented::PANIC,
+ panic_unimplemented::TODO,
+ panic_unimplemented::UNIMPLEMENTED,
+ panic_unimplemented::UNREACHABLE,
+ partialeq_ne_impl::PARTIALEQ_NE_IMPL,
+ pass_by_ref_or_value::LARGE_TYPES_PASSED_BY_VALUE,
+ pass_by_ref_or_value::TRIVIALLY_COPY_PASS_BY_REF,
+ path_buf_push_overwrite::PATH_BUF_PUSH_OVERWRITE,
+ pattern_type_mismatch::PATTERN_TYPE_MISMATCH,
+ precedence::PRECEDENCE,
+ ptr::CMP_NULL,
+ ptr::INVALID_NULL_PTR_USAGE,
+ ptr::MUT_FROM_REF,
+ ptr::PTR_ARG,
+ ptr_eq::PTR_EQ,
+ ptr_offset_with_cast::PTR_OFFSET_WITH_CAST,
+ pub_use::PUB_USE,
+ question_mark::QUESTION_MARK,
+ ranges::MANUAL_RANGE_CONTAINS,
+ ranges::RANGE_MINUS_ONE,
+ ranges::RANGE_PLUS_ONE,
+ ranges::RANGE_ZIP_WITH_LEN,
+ ranges::REVERSED_EMPTY_RANGES,
+ rc_clone_in_vec_init::RC_CLONE_IN_VEC_INIT,
+ redundant_clone::REDUNDANT_CLONE,
+ redundant_closure_call::REDUNDANT_CLOSURE_CALL,
+ redundant_else::REDUNDANT_ELSE,
+ redundant_field_names::REDUNDANT_FIELD_NAMES,
+ redundant_pub_crate::REDUNDANT_PUB_CRATE,
+ redundant_slicing::DEREF_BY_SLICING,
+ redundant_slicing::REDUNDANT_SLICING,
+ redundant_static_lifetimes::REDUNDANT_STATIC_LIFETIMES,
+ ref_option_ref::REF_OPTION_REF,
+ reference::DEREF_ADDROF,
+ regex::INVALID_REGEX,
+ regex::TRIVIAL_REGEX,
+ repeat_once::REPEAT_ONCE,
+ return_self_not_must_use::RETURN_SELF_NOT_MUST_USE,
+ returns::LET_AND_RETURN,
+ returns::NEEDLESS_RETURN,
+ same_name_method::SAME_NAME_METHOD,
+ self_assignment::SELF_ASSIGNMENT,
+ self_named_constructors::SELF_NAMED_CONSTRUCTORS,
+ semicolon_if_nothing_returned::SEMICOLON_IF_NOTHING_RETURNED,
+ serde_api::SERDE_API_MISUSE,
+ shadow::SHADOW_REUSE,
+ shadow::SHADOW_SAME,
+ shadow::SHADOW_UNRELATED,
- try_err::TRY_ERR,
+ single_char_lifetime_names::SINGLE_CHAR_LIFETIME_NAMES,
+ single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS,
+ size_of_in_element_count::SIZE_OF_IN_ELEMENT_COUNT,
+ slow_vector_initialization::SLOW_VECTOR_INITIALIZATION,
+ stable_sort_primitive::STABLE_SORT_PRIMITIVE,
+ strings::STRING_ADD,
+ strings::STRING_ADD_ASSIGN,
+ strings::STRING_FROM_UTF8_AS_BYTES,
+ strings::STRING_LIT_AS_BYTES,
+ strings::STRING_SLICE,
+ strings::STRING_TO_STRING,
+ strings::STR_TO_STRING,
+ strings::TRIM_SPLIT_WHITESPACE,
+ strlen_on_c_strings::STRLEN_ON_C_STRINGS,
+ suspicious_operation_groupings::SUSPICIOUS_OPERATION_GROUPINGS,
+ suspicious_trait_impl::SUSPICIOUS_ARITHMETIC_IMPL,
+ suspicious_trait_impl::SUSPICIOUS_OP_ASSIGN_IMPL,
+ swap::ALMOST_SWAPPED,
+ swap::MANUAL_SWAP,
++ swap_ptr_to_ref::SWAP_PTR_TO_REF,
+ tabs_in_doc_comments::TABS_IN_DOC_COMMENTS,
+ temporary_assignment::TEMPORARY_ASSIGNMENT,
+ to_digit_is_some::TO_DIGIT_IS_SOME,
+ trailing_empty_array::TRAILING_EMPTY_ARRAY,
+ trait_bounds::TRAIT_DUPLICATION_IN_BOUNDS,
+ trait_bounds::TYPE_REPETITION_IN_BOUNDS,
+ transmute::CROSSPOINTER_TRANSMUTE,
+ transmute::TRANSMUTES_EXPRESSIBLE_AS_PTR_CASTS,
+ transmute::TRANSMUTE_BYTES_TO_STR,
+ transmute::TRANSMUTE_FLOAT_TO_INT,
+ transmute::TRANSMUTE_INT_TO_BOOL,
+ transmute::TRANSMUTE_INT_TO_CHAR,
+ transmute::TRANSMUTE_INT_TO_FLOAT,
+ transmute::TRANSMUTE_NUM_TO_BYTES,
+ transmute::TRANSMUTE_PTR_TO_PTR,
+ transmute::TRANSMUTE_PTR_TO_REF,
+ transmute::TRANSMUTE_UNDEFINED_REPR,
+ transmute::UNSOUND_COLLECTION_TRANSMUTE,
+ transmute::USELESS_TRANSMUTE,
+ transmute::WRONG_TRANSMUTE,
+ transmuting_null::TRANSMUTING_NULL,
+ types::BORROWED_BOX,
+ types::BOX_COLLECTION,
+ types::LINKEDLIST,
+ types::OPTION_OPTION,
+ types::RC_BUFFER,
+ types::RC_MUTEX,
+ types::REDUNDANT_ALLOCATION,
+ types::TYPE_COMPLEXITY,
+ types::VEC_BOX,
+ undocumented_unsafe_blocks::UNDOCUMENTED_UNSAFE_BLOCKS,
+ unicode::INVISIBLE_CHARACTERS,
+ unicode::NON_ASCII_LITERAL,
+ unicode::UNICODE_NOT_NFC,
+ uninit_vec::UNINIT_VEC,
+ unit_hash::UNIT_HASH,
+ unit_return_expecting_ord::UNIT_RETURN_EXPECTING_ORD,
+ unit_types::LET_UNIT_VALUE,
+ unit_types::UNIT_ARG,
+ unit_types::UNIT_CMP,
+ unnamed_address::FN_ADDRESS_COMPARISONS,
+ unnamed_address::VTABLE_ADDRESS_COMPARISONS,
+ unnecessary_owned_empty_strings::UNNECESSARY_OWNED_EMPTY_STRINGS,
+ unnecessary_self_imports::UNNECESSARY_SELF_IMPORTS,
+ unnecessary_sort_by::UNNECESSARY_SORT_BY,
+ unnecessary_wraps::UNNECESSARY_WRAPS,
+ unnested_or_patterns::UNNESTED_OR_PATTERNS,
+ unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME,
+ unused_async::UNUSED_ASYNC,
+ unused_io_amount::UNUSED_IO_AMOUNT,
++ unused_rounding::UNUSED_ROUNDING,
+ unused_self::UNUSED_SELF,
+ unused_unit::UNUSED_UNIT,
+ unwrap::PANICKING_UNWRAP,
+ unwrap::UNNECESSARY_UNWRAP,
+ unwrap_in_result::UNWRAP_IN_RESULT,
+ upper_case_acronyms::UPPER_CASE_ACRONYMS,
+ use_self::USE_SELF,
+ useless_conversion::USELESS_CONVERSION,
+ vec::USELESS_VEC,
+ vec_init_then_push::VEC_INIT_THEN_PUSH,
+ vec_resize_to_zero::VEC_RESIZE_TO_ZERO,
+ verbose_file_reads::VERBOSE_FILE_READS,
+ wildcard_imports::ENUM_GLOB_USE,
+ wildcard_imports::WILDCARD_IMPORTS,
+ write::PRINTLN_EMPTY_STRING,
+ write::PRINT_LITERAL,
+ write::PRINT_STDERR,
+ write::PRINT_STDOUT,
+ write::PRINT_WITH_NEWLINE,
+ write::USE_DEBUG,
+ write::WRITELN_EMPTY_STRING,
+ write::WRITE_LITERAL,
+ write::WRITE_WITH_NEWLINE,
+ zero_div_zero::ZERO_DIVIDED_BY_ZERO,
+ zero_sized_map_values::ZERO_SIZED_MAP_VALUES,
+])
--- /dev/null
- LintId::of(significant_drop_in_scrutinee::SIGNIFICANT_DROP_IN_SCRUTINEE),
+// This file was generated by `cargo dev update_lints`.
+// Use that command to update this file and do not edit by hand.
+// Manual edits will be overwritten.
+
+store.register_group(true, "clippy::nursery", Some("clippy_nursery"), vec![
+ LintId::of(attrs::EMPTY_LINE_AFTER_OUTER_ATTR),
+ LintId::of(cognitive_complexity::COGNITIVE_COMPLEXITY),
+ LintId::of(copies::BRANCHES_SHARING_CODE),
+ LintId::of(equatable_if_let::EQUATABLE_IF_LET),
+ LintId::of(fallible_impl_from::FALLIBLE_IMPL_FROM),
+ LintId::of(floating_point_arithmetic::IMPRECISE_FLOPS),
+ LintId::of(floating_point_arithmetic::SUBOPTIMAL_FLOPS),
+ LintId::of(future_not_send::FUTURE_NOT_SEND),
+ LintId::of(index_refutable_slice::INDEX_REFUTABLE_SLICE),
+ LintId::of(let_if_seq::USELESS_LET_IF_SEQ),
+ LintId::of(methods::ITER_WITH_DRAIN),
+ LintId::of(missing_const_for_fn::MISSING_CONST_FOR_FN),
+ LintId::of(mutable_debug_assertion::DEBUG_ASSERT_WITH_MUT_CALL),
+ LintId::of(mutex_atomic::MUTEX_ATOMIC),
+ LintId::of(mutex_atomic::MUTEX_INTEGER),
+ LintId::of(non_send_fields_in_send_ty::NON_SEND_FIELDS_IN_SEND_TY),
+ LintId::of(nonstandard_macro_braces::NONSTANDARD_MACRO_BRACES),
+ LintId::of(only_used_in_recursion::ONLY_USED_IN_RECURSION),
+ LintId::of(option_if_let_else::OPTION_IF_LET_ELSE),
+ LintId::of(path_buf_push_overwrite::PATH_BUF_PUSH_OVERWRITE),
+ LintId::of(redundant_pub_crate::REDUNDANT_PUB_CRATE),
+ LintId::of(regex::TRIVIAL_REGEX),
- LintId::of(transmute::USELESS_TRANSMUTE),
+ LintId::of(strings::STRING_LIT_AS_BYTES),
+ LintId::of(suspicious_operation_groupings::SUSPICIOUS_OPERATION_GROUPINGS),
+ LintId::of(trailing_empty_array::TRAILING_EMPTY_ARRAY),
+ LintId::of(transmute::TRANSMUTE_UNDEFINED_REPR),
++ LintId::of(unused_rounding::UNUSED_ROUNDING),
+ LintId::of(use_self::USE_SELF),
+])
--- /dev/null
- LintId::of(match_on_vec_items::MATCH_ON_VEC_ITEMS),
+// This file was generated by `cargo dev update_lints`.
+// Use that command to update this file and do not edit by hand.
+// Manual edits will be overwritten.
+
+store.register_group(true, "clippy::pedantic", Some("clippy_pedantic"), vec![
+ LintId::of(attrs::INLINE_ALWAYS),
+ LintId::of(bit_mask::VERBOSE_BIT_MASK),
+ LintId::of(borrow_as_ptr::BORROW_AS_PTR),
+ LintId::of(bytecount::NAIVE_BYTECOUNT),
+ LintId::of(case_sensitive_file_extension_comparisons::CASE_SENSITIVE_FILE_EXTENSION_COMPARISONS),
+ LintId::of(casts::CAST_LOSSLESS),
+ LintId::of(casts::CAST_POSSIBLE_TRUNCATION),
+ LintId::of(casts::CAST_POSSIBLE_WRAP),
+ LintId::of(casts::CAST_PRECISION_LOSS),
+ LintId::of(casts::CAST_PTR_ALIGNMENT),
+ LintId::of(casts::CAST_SIGN_LOSS),
+ LintId::of(casts::PTR_AS_PTR),
+ LintId::of(checked_conversions::CHECKED_CONVERSIONS),
+ LintId::of(copies::SAME_FUNCTIONS_IN_IF_CONDITION),
+ LintId::of(copy_iterator::COPY_ITERATOR),
+ LintId::of(default::DEFAULT_TRAIT_ACCESS),
+ LintId::of(dereference::EXPLICIT_DEREF_METHODS),
+ LintId::of(dereference::REF_BINDING_TO_REFERENCE),
+ LintId::of(derive::EXPL_IMPL_CLONE_ON_COPY),
+ LintId::of(derive::UNSAFE_DERIVE_DESERIALIZE),
+ LintId::of(doc::DOC_MARKDOWN),
+ LintId::of(doc::MISSING_ERRORS_DOC),
+ LintId::of(doc::MISSING_PANICS_DOC),
++ LintId::of(doc_link_with_quotes::DOC_LINK_WITH_QUOTES),
+ LintId::of(empty_enum::EMPTY_ENUM),
+ LintId::of(enum_variants::MODULE_NAME_REPETITIONS),
+ LintId::of(eta_reduction::REDUNDANT_CLOSURE_FOR_METHOD_CALLS),
+ LintId::of(excessive_bools::FN_PARAMS_EXCESSIVE_BOOLS),
+ LintId::of(excessive_bools::STRUCT_EXCESSIVE_BOOLS),
+ LintId::of(functions::MUST_USE_CANDIDATE),
+ LintId::of(functions::TOO_MANY_LINES),
+ LintId::of(if_not_else::IF_NOT_ELSE),
+ LintId::of(implicit_hasher::IMPLICIT_HASHER),
+ LintId::of(implicit_saturating_sub::IMPLICIT_SATURATING_SUB),
+ LintId::of(inconsistent_struct_constructor::INCONSISTENT_STRUCT_CONSTRUCTOR),
+ LintId::of(infinite_iter::MAYBE_INFINITE_ITER),
+ LintId::of(invalid_upcast_comparisons::INVALID_UPCAST_COMPARISONS),
+ LintId::of(items_after_statements::ITEMS_AFTER_STATEMENTS),
+ LintId::of(iter_not_returning_iterator::ITER_NOT_RETURNING_ITERATOR),
+ LintId::of(large_stack_arrays::LARGE_STACK_ARRAYS),
+ LintId::of(let_underscore::LET_UNDERSCORE_DROP),
+ LintId::of(literal_representation::LARGE_DIGIT_GROUPS),
+ LintId::of(literal_representation::UNREADABLE_LITERAL),
+ LintId::of(loops::EXPLICIT_INTO_ITER_LOOP),
+ LintId::of(loops::EXPLICIT_ITER_LOOP),
+ LintId::of(macro_use::MACRO_USE_IMPORTS),
+ LintId::of(manual_assert::MANUAL_ASSERT),
+ LintId::of(manual_ok_or::MANUAL_OK_OR),
+ LintId::of(matches::MATCH_BOOL),
++ LintId::of(matches::MATCH_ON_VEC_ITEMS),
+ LintId::of(matches::MATCH_SAME_ARMS),
+ LintId::of(matches::MATCH_WILDCARD_FOR_SINGLE_VARIANTS),
+ LintId::of(matches::MATCH_WILD_ERR_ARM),
+ LintId::of(matches::SINGLE_MATCH_ELSE),
+ LintId::of(methods::CLONED_INSTEAD_OF_COPIED),
+ LintId::of(methods::FILTER_MAP_NEXT),
+ LintId::of(methods::FLAT_MAP_OPTION),
+ LintId::of(methods::FROM_ITER_INSTEAD_OF_COLLECT),
+ LintId::of(methods::IMPLICIT_CLONE),
+ LintId::of(methods::INEFFICIENT_TO_STRING),
+ LintId::of(methods::MAP_UNWRAP_OR),
+ LintId::of(methods::UNNECESSARY_JOIN),
+ LintId::of(misc::FLOAT_CMP),
+ LintId::of(misc::USED_UNDERSCORE_BINDING),
++ LintId::of(mismatching_type_param_order::MISMATCHING_TYPE_PARAM_ORDER),
+ LintId::of(mut_mut::MUT_MUT),
+ LintId::of(needless_bitwise_bool::NEEDLESS_BITWISE_BOOL),
+ LintId::of(needless_continue::NEEDLESS_CONTINUE),
+ LintId::of(needless_for_each::NEEDLESS_FOR_EACH),
+ LintId::of(needless_pass_by_value::NEEDLESS_PASS_BY_VALUE),
+ LintId::of(no_effect::NO_EFFECT_UNDERSCORE_BINDING),
+ LintId::of(non_expressive_names::MANY_SINGLE_CHAR_NAMES),
+ LintId::of(non_expressive_names::SIMILAR_NAMES),
+ LintId::of(pass_by_ref_or_value::LARGE_TYPES_PASSED_BY_VALUE),
+ LintId::of(pass_by_ref_or_value::TRIVIALLY_COPY_PASS_BY_REF),
+ LintId::of(ranges::RANGE_MINUS_ONE),
+ LintId::of(ranges::RANGE_PLUS_ONE),
+ LintId::of(redundant_else::REDUNDANT_ELSE),
+ LintId::of(ref_option_ref::REF_OPTION_REF),
+ LintId::of(return_self_not_must_use::RETURN_SELF_NOT_MUST_USE),
+ LintId::of(semicolon_if_nothing_returned::SEMICOLON_IF_NOTHING_RETURNED),
+ LintId::of(stable_sort_primitive::STABLE_SORT_PRIMITIVE),
+ LintId::of(strings::STRING_ADD_ASSIGN),
+ LintId::of(trait_bounds::TRAIT_DUPLICATION_IN_BOUNDS),
+ LintId::of(trait_bounds::TYPE_REPETITION_IN_BOUNDS),
+ LintId::of(transmute::TRANSMUTE_PTR_TO_PTR),
+ LintId::of(types::LINKEDLIST),
+ LintId::of(types::OPTION_OPTION),
+ LintId::of(unicode::UNICODE_NOT_NFC),
+ LintId::of(unnecessary_wraps::UNNECESSARY_WRAPS),
+ LintId::of(unnested_or_patterns::UNNESTED_OR_PATTERNS),
+ LintId::of(unused_async::UNUSED_ASYNC),
+ LintId::of(unused_self::UNUSED_SELF),
+ LintId::of(wildcard_imports::ENUM_GLOB_USE),
+ LintId::of(wildcard_imports::WILDCARD_IMPORTS),
+ LintId::of(zero_sized_map_values::ZERO_SIZED_MAP_VALUES),
+])
--- /dev/null
- LintId::of(arithmetic::FLOAT_ARITHMETIC),
- LintId::of(arithmetic::INTEGER_ARITHMETIC),
+// This file was generated by `cargo dev update_lints`.
+// Use that command to update this file and do not edit by hand.
+// Manual edits will be overwritten.
+
+store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![
- LintId::of(try_err::TRY_ERR),
+ LintId::of(as_conversions::AS_CONVERSIONS),
++ LintId::of(as_underscore::AS_UNDERSCORE),
+ LintId::of(asm_syntax::INLINE_ASM_X86_ATT_SYNTAX),
+ LintId::of(asm_syntax::INLINE_ASM_X86_INTEL_SYNTAX),
+ LintId::of(attrs::ALLOW_ATTRIBUTES_WITHOUT_REASON),
+ LintId::of(casts::FN_TO_NUMERIC_CAST_ANY),
+ LintId::of(create_dir::CREATE_DIR),
+ LintId::of(dbg_macro::DBG_MACRO),
+ LintId::of(default_numeric_fallback::DEFAULT_NUMERIC_FALLBACK),
+ LintId::of(default_union_representation::DEFAULT_UNION_REPRESENTATION),
+ LintId::of(disallowed_script_idents::DISALLOWED_SCRIPT_IDENTS),
+ LintId::of(else_if_without_else::ELSE_IF_WITHOUT_ELSE),
+ LintId::of(empty_drop::EMPTY_DROP),
+ LintId::of(empty_structs_with_brackets::EMPTY_STRUCTS_WITH_BRACKETS),
+ LintId::of(exhaustive_items::EXHAUSTIVE_ENUMS),
+ LintId::of(exhaustive_items::EXHAUSTIVE_STRUCTS),
+ LintId::of(exit::EXIT),
+ LintId::of(float_literal::LOSSY_FLOAT_LITERAL),
+ LintId::of(if_then_some_else_none::IF_THEN_SOME_ELSE_NONE),
+ LintId::of(implicit_return::IMPLICIT_RETURN),
+ LintId::of(indexing_slicing::INDEXING_SLICING),
+ LintId::of(inherent_impl::MULTIPLE_INHERENT_IMPL),
+ LintId::of(integer_division::INTEGER_DIVISION),
+ LintId::of(large_include_file::LARGE_INCLUDE_FILE),
+ LintId::of(let_underscore::LET_UNDERSCORE_MUST_USE),
+ LintId::of(literal_representation::DECIMAL_LITERAL_REPRESENTATION),
+ LintId::of(map_err_ignore::MAP_ERR_IGNORE),
+ LintId::of(matches::REST_PAT_IN_FULLY_BOUND_STRUCTS),
++ LintId::of(matches::TRY_ERR),
+ LintId::of(matches::WILDCARD_ENUM_MATCH_ARM),
+ LintId::of(mem_forget::MEM_FORGET),
+ LintId::of(methods::CLONE_ON_REF_PTR),
+ LintId::of(methods::EXPECT_USED),
+ LintId::of(methods::FILETYPE_IS_FILE),
+ LintId::of(methods::GET_UNWRAP),
+ LintId::of(methods::UNWRAP_USED),
+ LintId::of(misc::FLOAT_CMP_CONST),
+ LintId::of(misc_early::SEPARATED_LITERAL_SUFFIX),
+ LintId::of(misc_early::UNNEEDED_FIELD_PATTERN),
+ LintId::of(misc_early::UNSEPARATED_LITERAL_SUFFIX),
+ LintId::of(missing_doc::MISSING_DOCS_IN_PRIVATE_ITEMS),
+ LintId::of(missing_enforced_import_rename::MISSING_ENFORCED_IMPORT_RENAMES),
+ LintId::of(missing_inline::MISSING_INLINE_IN_PUBLIC_ITEMS),
+ LintId::of(mixed_read_write_in_expression::MIXED_READ_WRITE_IN_EXPRESSION),
+ LintId::of(module_style::MOD_MODULE_FILES),
+ LintId::of(module_style::SELF_NAMED_MODULE_FILES),
+ LintId::of(modulo_arithmetic::MODULO_ARITHMETIC),
++ LintId::of(numeric_arithmetic::FLOAT_ARITHMETIC),
++ LintId::of(numeric_arithmetic::INTEGER_ARITHMETIC),
+ LintId::of(panic_in_result_fn::PANIC_IN_RESULT_FN),
+ LintId::of(panic_unimplemented::PANIC),
+ LintId::of(panic_unimplemented::TODO),
+ LintId::of(panic_unimplemented::UNIMPLEMENTED),
+ LintId::of(panic_unimplemented::UNREACHABLE),
+ LintId::of(pattern_type_mismatch::PATTERN_TYPE_MISMATCH),
+ LintId::of(pub_use::PUB_USE),
+ LintId::of(redundant_slicing::DEREF_BY_SLICING),
+ LintId::of(same_name_method::SAME_NAME_METHOD),
+ LintId::of(shadow::SHADOW_REUSE),
+ LintId::of(shadow::SHADOW_SAME),
+ LintId::of(shadow::SHADOW_UNRELATED),
+ LintId::of(single_char_lifetime_names::SINGLE_CHAR_LIFETIME_NAMES),
+ LintId::of(strings::STRING_ADD),
+ LintId::of(strings::STRING_SLICE),
+ LintId::of(strings::STRING_TO_STRING),
+ LintId::of(strings::STR_TO_STRING),
+ LintId::of(types::RC_BUFFER),
+ LintId::of(types::RC_MUTEX),
+ LintId::of(undocumented_unsafe_blocks::UNDOCUMENTED_UNSAFE_BLOCKS),
+ LintId::of(unicode::NON_ASCII_LITERAL),
+ LintId::of(unnecessary_self_imports::UNNECESSARY_SELF_IMPORTS),
+ LintId::of(unwrap_in_result::UNWRAP_IN_RESULT),
+ LintId::of(verbose_file_reads::VERBOSE_FILE_READS),
+ LintId::of(write::PRINT_STDERR),
+ LintId::of(write::PRINT_STDOUT),
+ LintId::of(write::USE_DEBUG),
+])
--- /dev/null
- LintId::of(collapsible_match::COLLAPSIBLE_MATCH),
+// This file was generated by `cargo dev update_lints`.
+// Use that command to update this file and do not edit by hand.
+// Manual edits will be overwritten.
+
+store.register_group(true, "clippy::style", Some("clippy_style"), vec![
+ LintId::of(assertions_on_constants::ASSERTIONS_ON_CONSTANTS),
+ LintId::of(assign_ops::ASSIGN_OP_PATTERN),
+ LintId::of(blacklisted_name::BLACKLISTED_NAME),
+ LintId::of(blocks_in_if_conditions::BLOCKS_IN_IF_CONDITIONS),
+ LintId::of(bool_assert_comparison::BOOL_ASSERT_COMPARISON),
+ LintId::of(casts::FN_TO_NUMERIC_CAST),
+ LintId::of(casts::FN_TO_NUMERIC_CAST_WITH_TRUNCATION),
+ LintId::of(collapsible_if::COLLAPSIBLE_ELSE_IF),
+ LintId::of(collapsible_if::COLLAPSIBLE_IF),
- LintId::of(manual_map::MANUAL_MAP),
+ LintId::of(comparison_chain::COMPARISON_CHAIN),
+ LintId::of(default::FIELD_REASSIGN_WITH_DEFAULT),
+ LintId::of(dereference::NEEDLESS_BORROW),
+ LintId::of(derive::DERIVE_PARTIAL_EQ_WITHOUT_EQ),
+ LintId::of(disallowed_methods::DISALLOWED_METHODS),
+ LintId::of(disallowed_types::DISALLOWED_TYPES),
+ LintId::of(doc::MISSING_SAFETY_DOC),
+ LintId::of(doc::NEEDLESS_DOCTEST_MAIN),
+ LintId::of(enum_variants::ENUM_VARIANT_NAMES),
+ LintId::of(enum_variants::MODULE_INCEPTION),
+ LintId::of(eq_op::OP_REF),
+ LintId::of(eta_reduction::REDUNDANT_CLOSURE),
+ LintId::of(float_literal::EXCESSIVE_PRECISION),
+ LintId::of(from_over_into::FROM_OVER_INTO),
+ LintId::of(from_str_radix_10::FROM_STR_RADIX_10),
+ LintId::of(functions::DOUBLE_MUST_USE),
+ LintId::of(functions::MUST_USE_UNIT),
+ LintId::of(functions::RESULT_UNIT_ERR),
++ LintId::of(get_first::GET_FIRST),
+ LintId::of(inherent_to_string::INHERENT_TO_STRING),
+ LintId::of(init_numbered_fields::INIT_NUMBERED_FIELDS),
+ LintId::of(len_zero::COMPARISON_TO_EMPTY),
+ LintId::of(len_zero::LEN_WITHOUT_IS_EMPTY),
+ LintId::of(len_zero::LEN_ZERO),
+ LintId::of(literal_representation::INCONSISTENT_DIGIT_GROUPING),
+ LintId::of(literal_representation::UNUSUAL_BYTE_GROUPINGS),
+ LintId::of(loops::FOR_KV_MAP),
+ LintId::of(loops::NEEDLESS_RANGE_LOOP),
+ LintId::of(loops::SAME_ITEM_PUSH),
+ LintId::of(loops::WHILE_LET_ON_ITERATOR),
+ LintId::of(main_recursion::MAIN_RECURSION),
+ LintId::of(manual_async_fn::MANUAL_ASYNC_FN),
+ LintId::of(manual_bits::MANUAL_BITS),
+ LintId::of(manual_non_exhaustive::MANUAL_NON_EXHAUSTIVE),
+ LintId::of(map_clone::MAP_CLONE),
+ LintId::of(match_result_ok::MATCH_RESULT_OK),
++ LintId::of(matches::COLLAPSIBLE_MATCH),
+ LintId::of(matches::INFALLIBLE_DESTRUCTURING_MATCH),
++ LintId::of(matches::MANUAL_MAP),
+ LintId::of(matches::MATCH_LIKE_MATCHES_MACRO),
+ LintId::of(matches::MATCH_OVERLAPPING_ARM),
+ LintId::of(matches::MATCH_REF_PATS),
+ LintId::of(matches::REDUNDANT_PATTERN_MATCHING),
+ LintId::of(matches::SINGLE_MATCH),
+ LintId::of(mem_replace::MEM_REPLACE_OPTION_WITH_NONE),
+ LintId::of(mem_replace::MEM_REPLACE_WITH_DEFAULT),
+ LintId::of(methods::BYTES_NTH),
+ LintId::of(methods::CHARS_LAST_CMP),
+ LintId::of(methods::CHARS_NEXT_CMP),
+ LintId::of(methods::ERR_EXPECT),
+ LintId::of(methods::INTO_ITER_ON_REF),
+ LintId::of(methods::IS_DIGIT_ASCII_RADIX),
+ LintId::of(methods::ITER_CLONED_COLLECT),
+ LintId::of(methods::ITER_NEXT_SLICE),
+ LintId::of(methods::ITER_NTH_ZERO),
+ LintId::of(methods::ITER_SKIP_NEXT),
+ LintId::of(methods::MANUAL_SATURATING_ARITHMETIC),
+ LintId::of(methods::MAP_COLLECT_RESULT_UNIT),
+ LintId::of(methods::NEW_RET_NO_SELF),
+ LintId::of(methods::OK_EXPECT),
+ LintId::of(methods::OPTION_MAP_OR_NONE),
+ LintId::of(methods::RESULT_MAP_OR_INTO_OPTION),
+ LintId::of(methods::SHOULD_IMPLEMENT_TRAIT),
+ LintId::of(methods::SINGLE_CHAR_ADD_STR),
+ LintId::of(methods::STRING_EXTEND_CHARS),
+ LintId::of(methods::UNNECESSARY_FOLD),
+ LintId::of(methods::UNNECESSARY_LAZY_EVALUATIONS),
+ LintId::of(methods::UNWRAP_OR_ELSE_DEFAULT),
+ LintId::of(methods::WRONG_SELF_CONVENTION),
+ LintId::of(misc::TOPLEVEL_REF_ARG),
+ LintId::of(misc::ZERO_PTR),
+ LintId::of(misc_early::BUILTIN_TYPE_SHADOW),
+ LintId::of(misc_early::DOUBLE_NEG),
+ LintId::of(misc_early::DUPLICATE_UNDERSCORE_ARGUMENT),
+ LintId::of(misc_early::MIXED_CASE_HEX_LITERALS),
+ LintId::of(misc_early::REDUNDANT_PATTERN),
+ LintId::of(mut_mutex_lock::MUT_MUTEX_LOCK),
+ LintId::of(mut_reference::UNNECESSARY_MUT_PASSED),
+ LintId::of(needless_late_init::NEEDLESS_LATE_INIT),
+ LintId::of(neg_multiply::NEG_MULTIPLY),
+ LintId::of(new_without_default::NEW_WITHOUT_DEFAULT),
+ LintId::of(non_copy_const::BORROW_INTERIOR_MUTABLE_CONST),
+ LintId::of(non_copy_const::DECLARE_INTERIOR_MUTABLE_CONST),
+ LintId::of(non_expressive_names::JUST_UNDERSCORES_AND_DIGITS),
+ LintId::of(ptr::CMP_NULL),
+ LintId::of(ptr::PTR_ARG),
+ LintId::of(ptr_eq::PTR_EQ),
+ LintId::of(question_mark::QUESTION_MARK),
+ LintId::of(ranges::MANUAL_RANGE_CONTAINS),
+ LintId::of(redundant_field_names::REDUNDANT_FIELD_NAMES),
+ LintId::of(redundant_static_lifetimes::REDUNDANT_STATIC_LIFETIMES),
+ LintId::of(returns::LET_AND_RETURN),
+ LintId::of(returns::NEEDLESS_RETURN),
+ LintId::of(self_named_constructors::SELF_NAMED_CONSTRUCTORS),
+ LintId::of(single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS),
+ LintId::of(strings::TRIM_SPLIT_WHITESPACE),
+ LintId::of(tabs_in_doc_comments::TABS_IN_DOC_COMMENTS),
+ LintId::of(to_digit_is_some::TO_DIGIT_IS_SOME),
+ LintId::of(unit_types::LET_UNIT_VALUE),
+ LintId::of(unnecessary_owned_empty_strings::UNNECESSARY_OWNED_EMPTY_STRINGS),
+ LintId::of(unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME),
+ LintId::of(unused_unit::UNUSED_UNIT),
+ LintId::of(upper_case_acronyms::UPPER_CASE_ACRONYMS),
+ LintId::of(write::PRINTLN_EMPTY_STRING),
+ LintId::of(write::PRINT_LITERAL),
+ LintId::of(write::PRINT_WITH_NEWLINE),
+ LintId::of(write::WRITELN_EMPTY_STRING),
+ LintId::of(write::WRITE_LITERAL),
+ LintId::of(write::WRITE_WITH_NEWLINE),
+])
--- /dev/null
- LintId::of(significant_drop_in_scrutinee::SIGNIFICANT_DROP_IN_SCRUTINEE),
+// This file was generated by `cargo dev update_lints`.
+// Use that command to update this file and do not edit by hand.
+// Manual edits will be overwritten.
+
+store.register_group(true, "clippy::suspicious", Some("clippy_suspicious"), vec![
++ LintId::of(almost_complete_letter_range::ALMOST_COMPLETE_LETTER_RANGE),
+ LintId::of(assign_ops::MISREFACTORED_ASSIGN_OP),
+ LintId::of(attrs::BLANKET_CLIPPY_RESTRICTION_LINTS),
+ LintId::of(await_holding_invalid::AWAIT_HOLDING_INVALID_TYPE),
+ LintId::of(await_holding_invalid::AWAIT_HOLDING_LOCK),
+ LintId::of(await_holding_invalid::AWAIT_HOLDING_REFCELL_REF),
+ LintId::of(casts::CAST_ABS_TO_UNSIGNED),
+ LintId::of(casts::CAST_ENUM_CONSTRUCTOR),
+ LintId::of(casts::CAST_ENUM_TRUNCATION),
+ LintId::of(crate_in_macro_def::CRATE_IN_MACRO_DEF),
+ LintId::of(drop_forget_ref::DROP_NON_DROP),
+ LintId::of(drop_forget_ref::FORGET_NON_DROP),
+ LintId::of(duplicate_mod::DUPLICATE_MOD),
+ LintId::of(float_equality_without_abs::FLOAT_EQUALITY_WITHOUT_ABS),
+ LintId::of(format_impl::PRINT_IN_FORMAT_IMPL),
+ LintId::of(formatting::SUSPICIOUS_ASSIGNMENT_FORMATTING),
+ LintId::of(formatting::SUSPICIOUS_ELSE_FORMATTING),
+ LintId::of(formatting::SUSPICIOUS_UNARY_OP_FORMATTING),
+ LintId::of(loops::EMPTY_LOOP),
+ LintId::of(loops::FOR_LOOPS_OVER_FALLIBLES),
+ LintId::of(loops::MUT_RANGE_BOUND),
++ LintId::of(matches::SIGNIFICANT_DROP_IN_SCRUTINEE),
++ LintId::of(methods::NO_EFFECT_REPLACE),
+ LintId::of(methods::SUSPICIOUS_MAP),
+ LintId::of(mut_key::MUTABLE_KEY_TYPE),
+ LintId::of(octal_escapes::OCTAL_ESCAPES),
+ LintId::of(rc_clone_in_vec_init::RC_CLONE_IN_VEC_INIT),
+ LintId::of(suspicious_trait_impl::SUSPICIOUS_ARITHMETIC_IMPL),
+ LintId::of(suspicious_trait_impl::SUSPICIOUS_OP_ASSIGN_IMPL),
++ LintId::of(swap_ptr_to_ref::SWAP_PTR_TO_REF),
+])
--- /dev/null
- mod arithmetic;
+// error-pattern:cargo-clippy
+
+#![feature(array_windows)]
+#![feature(binary_heap_into_iter_sorted)]
+#![feature(box_patterns)]
+#![feature(control_flow_enum)]
+#![feature(drain_filter)]
+#![feature(iter_intersperse)]
+#![feature(let_chains)]
+#![feature(let_else)]
+#![feature(lint_reasons)]
+#![feature(once_cell)]
+#![feature(rustc_private)]
+#![feature(stmt_expr_attributes)]
+#![recursion_limit = "512"]
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+#![allow(clippy::missing_docs_in_private_items, clippy::must_use_candidate)]
+#![warn(trivial_casts, trivial_numeric_casts)]
+// warn on lints, that are included in `rust-lang/rust`s bootstrap
+#![warn(rust_2018_idioms, unused_lifetimes)]
+// warn on rustc internal lints
+#![warn(rustc::internal)]
+// Disable this rustc lint for now, as it was also done in rustc
+#![allow(rustc::potential_query_instability)]
+
+// FIXME: switch to something more ergonomic here, once available.
+// (Currently there is no way to opt into sysroot crates without `extern crate`.)
+extern crate rustc_arena;
+extern crate rustc_ast;
+extern crate rustc_ast_pretty;
+extern crate rustc_attr;
+extern crate rustc_data_structures;
+extern crate rustc_driver;
+extern crate rustc_errors;
+extern crate rustc_hir;
+extern crate rustc_hir_pretty;
+extern crate rustc_index;
+extern crate rustc_infer;
+extern crate rustc_lexer;
+extern crate rustc_lint;
+extern crate rustc_middle;
+extern crate rustc_mir_dataflow;
+extern crate rustc_parse;
+extern crate rustc_parse_format;
+extern crate rustc_session;
+extern crate rustc_span;
+extern crate rustc_target;
+extern crate rustc_trait_selection;
+extern crate rustc_typeck;
+
+#[macro_use]
+extern crate clippy_utils;
+
+use clippy_utils::parse_msrv;
+use rustc_data_structures::fx::FxHashSet;
+use rustc_lint::LintId;
+use rustc_session::Session;
+
+/// Macro used to declare a Clippy lint.
+///
+/// Every lint declaration consists of 4 parts:
+///
+/// 1. The documentation, which is used for the website
+/// 2. The `LINT_NAME`. See [lint naming][lint_naming] on lint naming conventions.
+/// 3. The `lint_level`, which is a mapping from *one* of our lint groups to `Allow`, `Warn` or
+/// `Deny`. The lint level here has nothing to do with what lint groups the lint is a part of.
+/// 4. The `description` that contains a short explanation on what's wrong with code where the
+/// lint is triggered.
+///
+/// Currently the categories `style`, `correctness`, `suspicious`, `complexity` and `perf` are
+/// enabled by default. As said in the README.md of this repository, if the lint level mapping
+/// changes, please update README.md.
+///
+/// # Example
+///
+/// ```
+/// #![feature(rustc_private)]
+/// extern crate rustc_session;
+/// use rustc_session::declare_tool_lint;
+/// use clippy_lints::declare_clippy_lint;
+///
+/// declare_clippy_lint! {
+/// /// ### What it does
+/// /// Checks for ... (describe what the lint matches).
+/// ///
+/// /// ### Why is this bad?
+/// /// Supply the reason for linting the code.
+/// ///
+/// /// ### Example
+/// /// ```rust
+/// /// // Bad
+/// /// Insert a short example of code that triggers the lint
+/// ///
+/// /// // Good
+/// /// Insert a short example of improved code that doesn't trigger the lint
+/// /// ```
+/// pub LINT_NAME,
+/// pedantic,
+/// "description"
+/// }
+/// ```
+/// [lint_naming]: https://rust-lang.github.io/rfcs/0344-conventions-galore.html#lints
+#[macro_export]
+macro_rules! declare_clippy_lint {
+ { $(#[$attr:meta])* pub $name:tt, style, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Warn, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, correctness, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Deny, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, suspicious, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Warn, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, complexity, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Warn, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, perf, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Warn, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, pedantic, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Allow, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, restriction, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Allow, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, cargo, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Allow, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, nursery, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Allow, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, internal, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Allow, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, internal_warn, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Warn, $description, report_in_external_macro: true
+ }
+ };
+}
+
+#[cfg(feature = "internal")]
+mod deprecated_lints;
+#[cfg_attr(feature = "internal", allow(clippy::missing_clippy_version_attribute))]
+mod utils;
+
+mod renamed_lints;
+
+// begin lints modules, do not remove this comment, it’s used in `update_lints`
+mod absurd_extreme_comparisons;
++mod almost_complete_letter_range;
+mod approx_const;
- mod collapsible_match;
+mod as_conversions;
++mod as_underscore;
+mod asm_syntax;
+mod assertions_on_constants;
+mod assign_ops;
+mod async_yields_async;
+mod attrs;
+mod await_holding_invalid;
+mod bit_mask;
+mod blacklisted_name;
+mod blocks_in_if_conditions;
+mod bool_assert_comparison;
+mod booleans;
+mod borrow_as_ptr;
++mod borrow_deref_ref;
+mod bytecount;
+mod bytes_count_to_len;
+mod cargo;
+mod case_sensitive_file_extension_comparisons;
+mod casts;
+mod checked_conversions;
+mod cognitive_complexity;
+mod collapsible_if;
- mod get_last_with_len;
+mod comparison_chain;
+mod copies;
+mod copy_iterator;
+mod crate_in_macro_def;
+mod create_dir;
+mod dbg_macro;
+mod default;
+mod default_numeric_fallback;
+mod default_union_representation;
+mod dereference;
+mod derivable_impls;
+mod derive;
+mod disallowed_methods;
+mod disallowed_script_idents;
+mod disallowed_types;
+mod doc;
++mod doc_link_with_quotes;
+mod double_comparison;
+mod double_parens;
+mod drop_forget_ref;
+mod duplicate_mod;
+mod duration_subsec;
+mod else_if_without_else;
+mod empty_drop;
+mod empty_enum;
+mod empty_structs_with_brackets;
+mod entry;
+mod enum_clike;
+mod enum_variants;
+mod eq_op;
+mod equatable_if_let;
+mod erasing_op;
+mod escape;
+mod eta_reduction;
+mod excessive_bools;
+mod exhaustive_items;
+mod exit;
+mod explicit_write;
+mod fallible_impl_from;
+mod float_equality_without_abs;
+mod float_literal;
+mod floating_point_arithmetic;
+mod format;
+mod format_args;
+mod format_impl;
+mod format_push_string;
+mod formatting;
+mod from_over_into;
+mod from_str_radix_10;
+mod functions;
+mod future_not_send;
- mod manual_map;
++mod get_first;
+mod identity_op;
+mod if_let_mutex;
+mod if_not_else;
+mod if_then_some_else_none;
+mod implicit_hasher;
+mod implicit_return;
+mod implicit_saturating_sub;
+mod inconsistent_struct_constructor;
+mod index_refutable_slice;
+mod indexing_slicing;
+mod infinite_iter;
+mod inherent_impl;
+mod inherent_to_string;
+mod init_numbered_fields;
+mod inline_fn_without_body;
+mod int_plus_one;
+mod integer_division;
+mod invalid_upcast_comparisons;
+mod items_after_statements;
+mod iter_not_returning_iterator;
+mod large_const_arrays;
+mod large_enum_variant;
+mod large_include_file;
+mod large_stack_arrays;
+mod len_zero;
+mod let_if_seq;
+mod let_underscore;
+mod lifetimes;
+mod literal_representation;
+mod loops;
+mod macro_use;
+mod main_recursion;
+mod manual_assert;
+mod manual_async_fn;
+mod manual_bits;
- mod manual_unwrap_or;
+mod manual_non_exhaustive;
+mod manual_ok_or;
+mod manual_strip;
- mod match_on_vec_items;
+mod map_clone;
+mod map_err_ignore;
+mod map_unit_fn;
- mod match_str_case_mismatch;
+mod match_result_ok;
- mod significant_drop_in_scrutinee;
+mod matches;
+mod mem_forget;
+mod mem_replace;
+mod methods;
+mod minmax;
+mod misc;
+mod misc_early;
++mod mismatching_type_param_order;
+mod missing_const_for_fn;
+mod missing_doc;
+mod missing_enforced_import_rename;
+mod missing_inline;
+mod mixed_read_write_in_expression;
+mod module_style;
+mod modulo_arithmetic;
+mod mut_key;
+mod mut_mut;
+mod mut_mutex_lock;
+mod mut_reference;
+mod mutable_debug_assertion;
+mod mutex_atomic;
+mod needless_arbitrary_self_type;
+mod needless_bitwise_bool;
+mod needless_bool;
+mod needless_borrowed_ref;
+mod needless_continue;
+mod needless_for_each;
+mod needless_late_init;
+mod needless_pass_by_value;
+mod needless_question_mark;
+mod needless_update;
+mod neg_cmp_op_on_partial_ord;
+mod neg_multiply;
+mod new_without_default;
+mod no_effect;
+mod non_copy_const;
+mod non_expressive_names;
+mod non_octal_unix_permissions;
+mod non_send_fields_in_send_ty;
+mod nonstandard_macro_braces;
++mod numeric_arithmetic;
+mod octal_escapes;
+mod only_used_in_recursion;
+mod open_options;
+mod option_env_unwrap;
+mod option_if_let_else;
+mod overflow_check_conditional;
+mod panic_in_result_fn;
+mod panic_unimplemented;
+mod partialeq_ne_impl;
+mod pass_by_ref_or_value;
+mod path_buf_push_overwrite;
+mod pattern_type_mismatch;
+mod precedence;
+mod ptr;
+mod ptr_eq;
+mod ptr_offset_with_cast;
+mod pub_use;
+mod question_mark;
+mod ranges;
+mod rc_clone_in_vec_init;
+mod redundant_clone;
+mod redundant_closure_call;
+mod redundant_else;
+mod redundant_field_names;
+mod redundant_pub_crate;
+mod redundant_slicing;
+mod redundant_static_lifetimes;
+mod ref_option_ref;
+mod reference;
+mod regex;
+mod repeat_once;
+mod return_self_not_must_use;
+mod returns;
+mod same_name_method;
+mod self_assignment;
+mod self_named_constructors;
+mod semicolon_if_nothing_returned;
+mod serde_api;
+mod shadow;
- mod try_err;
+mod single_char_lifetime_names;
+mod single_component_path_imports;
+mod size_of_in_element_count;
+mod slow_vector_initialization;
+mod stable_sort_primitive;
+mod strings;
+mod strlen_on_c_strings;
+mod suspicious_operation_groupings;
+mod suspicious_trait_impl;
+mod swap;
++mod swap_ptr_to_ref;
+mod tabs_in_doc_comments;
+mod temporary_assignment;
+mod to_digit_is_some;
+mod trailing_empty_array;
+mod trait_bounds;
+mod transmute;
+mod transmuting_null;
- store.register_late_pass(|| Box::new(collapsible_match::CollapsibleMatch));
+mod types;
+mod undocumented_unsafe_blocks;
+mod unicode;
+mod uninit_vec;
+mod unit_hash;
+mod unit_return_expecting_ord;
+mod unit_types;
+mod unnamed_address;
+mod unnecessary_owned_empty_strings;
+mod unnecessary_self_imports;
+mod unnecessary_sort_by;
+mod unnecessary_wraps;
+mod unnested_or_patterns;
+mod unsafe_removed_from_name;
+mod unused_async;
+mod unused_io_amount;
++mod unused_rounding;
+mod unused_self;
+mod unused_unit;
+mod unwrap;
+mod unwrap_in_result;
+mod upper_case_acronyms;
+mod use_self;
+mod useless_conversion;
+mod vec;
+mod vec_init_then_push;
+mod vec_resize_to_zero;
+mod verbose_file_reads;
+mod wildcard_imports;
+mod write;
+mod zero_div_zero;
+mod zero_sized_map_values;
+// end lints modules, do not remove this comment, it’s used in `update_lints`
+
+pub use crate::utils::conf::Conf;
+use crate::utils::conf::{format_error, TryConf};
+
+/// Register all pre expansion lints
+///
+/// Pre-expansion lints run before any macro expansion has happened.
+///
+/// Note that due to the architecture of the compiler, currently `cfg_attr` attributes on crate
+/// level (i.e `#![cfg_attr(...)]`) will still be expanded even when using a pre-expansion pass.
+///
+/// Used in `./src/driver.rs`.
+pub fn register_pre_expansion_lints(store: &mut rustc_lint::LintStore, sess: &Session, conf: &Conf) {
+ // NOTE: Do not add any more pre-expansion passes. These should be removed eventually.
+
+ let msrv = conf.msrv.as_ref().and_then(|s| {
+ parse_msrv(s, None, None).or_else(|| {
+ sess.err(&format!(
+ "error reading Clippy's configuration file. `{}` is not a valid Rust version",
+ s
+ ));
+ None
+ })
+ });
+
+ store.register_pre_expansion_pass(|| Box::new(write::Write::default()));
+ store.register_pre_expansion_pass(move || Box::new(attrs::EarlyAttributes { msrv }));
+}
+
+#[doc(hidden)]
+pub fn read_conf(sess: &Session) -> Conf {
+ let file_name = match utils::conf::lookup_conf_file() {
+ Ok(Some(path)) => path,
+ Ok(None) => return Conf::default(),
+ Err(error) => {
+ sess.struct_err(&format!("error finding Clippy's configuration file: {}", error))
+ .emit();
+ return Conf::default();
+ },
+ };
+
+ let TryConf { conf, errors } = utils::conf::read(&file_name);
+ // all conf errors are non-fatal, we just use the default conf in case of error
+ for error in errors {
+ sess.struct_err(&format!(
+ "error reading Clippy's configuration file `{}`: {}",
+ file_name.display(),
+ format_error(error)
+ ))
+ .emit();
+ }
+
+ conf
+}
+
+/// Register all lints and lint groups with the rustc plugin registry
+///
+/// Used in `./src/driver.rs`.
+#[expect(clippy::too_many_lines)]
+pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &Conf) {
+ register_removed_non_tool_lints(store);
+
+ include!("lib.deprecated.rs");
+
+ include!("lib.register_lints.rs");
+ include!("lib.register_restriction.rs");
+ include!("lib.register_pedantic.rs");
+
+ #[cfg(feature = "internal")]
+ include!("lib.register_internal.rs");
+
+ include!("lib.register_all.rs");
+ include!("lib.register_style.rs");
+ include!("lib.register_complexity.rs");
+ include!("lib.register_correctness.rs");
+ include!("lib.register_suspicious.rs");
+ include!("lib.register_perf.rs");
+ include!("lib.register_cargo.rs");
+ include!("lib.register_nursery.rs");
+
+ #[cfg(feature = "internal")]
+ {
+ if std::env::var("ENABLE_METADATA_COLLECTION").eq(&Ok("1".to_string())) {
+ store.register_late_pass(|| Box::new(utils::internal_lints::metadata_collector::MetadataCollector::new()));
+ return;
+ }
+ }
+
+ // all the internal lints
+ #[cfg(feature = "internal")]
+ {
+ store.register_early_pass(|| Box::new(utils::internal_lints::ClippyLintsInternal));
+ store.register_early_pass(|| Box::new(utils::internal_lints::ProduceIce));
+ store.register_late_pass(|| Box::new(utils::internal_lints::CollapsibleCalls));
+ store.register_late_pass(|| Box::new(utils::internal_lints::CompilerLintFunctions::new()));
+ store.register_late_pass(|| Box::new(utils::internal_lints::IfChainStyle));
+ store.register_late_pass(|| Box::new(utils::internal_lints::InvalidPaths));
+ store.register_late_pass(|| Box::new(utils::internal_lints::InterningDefinedSymbol::default()));
+ store.register_late_pass(|| Box::new(utils::internal_lints::LintWithoutLintPass::default()));
+ store.register_late_pass(|| Box::new(utils::internal_lints::MatchTypeOnDiagItem));
+ store.register_late_pass(|| Box::new(utils::internal_lints::OuterExpnDataPass));
+ store.register_late_pass(|| Box::new(utils::internal_lints::MsrvAttrImpl));
+ }
+
+ store.register_late_pass(|| Box::new(utils::dump_hir::DumpHir));
+ store.register_late_pass(|| Box::new(utils::author::Author));
+ let await_holding_invalid_types = conf.await_holding_invalid_types.clone();
+ store.register_late_pass(move || {
+ Box::new(await_holding_invalid::AwaitHolding::new(
+ await_holding_invalid_types.clone(),
+ ))
+ });
+ store.register_late_pass(|| Box::new(serde_api::SerdeApi));
+ let vec_box_size_threshold = conf.vec_box_size_threshold;
+ let type_complexity_threshold = conf.type_complexity_threshold;
+ let avoid_breaking_exported_api = conf.avoid_breaking_exported_api;
+ store.register_late_pass(move || {
+ Box::new(types::Types::new(
+ vec_box_size_threshold,
+ type_complexity_threshold,
+ avoid_breaking_exported_api,
+ ))
+ });
+ store.register_late_pass(|| Box::new(booleans::NonminimalBool));
+ store.register_late_pass(|| Box::new(needless_bitwise_bool::NeedlessBitwiseBool));
+ store.register_late_pass(|| Box::new(eq_op::EqOp));
+ store.register_late_pass(|| Box::new(enum_clike::UnportableVariant));
+ store.register_late_pass(|| Box::new(float_literal::FloatLiteral));
+ let verbose_bit_mask_threshold = conf.verbose_bit_mask_threshold;
+ store.register_late_pass(move || Box::new(bit_mask::BitMask::new(verbose_bit_mask_threshold)));
+ store.register_late_pass(|| Box::new(ptr::Ptr));
+ store.register_late_pass(|| Box::new(ptr_eq::PtrEq));
+ store.register_late_pass(|| Box::new(needless_bool::NeedlessBool));
+ store.register_late_pass(|| Box::new(needless_bool::BoolComparison));
+ store.register_late_pass(|| Box::new(needless_for_each::NeedlessForEach));
+ store.register_late_pass(|| Box::new(misc::MiscLints));
+ store.register_late_pass(|| Box::new(eta_reduction::EtaReduction));
+ store.register_late_pass(|| Box::new(identity_op::IdentityOp));
+ store.register_late_pass(|| Box::new(erasing_op::ErasingOp));
+ store.register_late_pass(|| Box::new(mut_mut::MutMut));
+ store.register_late_pass(|| Box::new(mut_reference::UnnecessaryMutPassed));
+ store.register_late_pass(|| Box::new(len_zero::LenZero));
+ store.register_late_pass(|| Box::new(attrs::Attributes));
+ store.register_late_pass(|| Box::new(blocks_in_if_conditions::BlocksInIfConditions));
- store.register_late_pass(|| Box::new(get_last_with_len::GetLastWithLen));
+ store.register_late_pass(|| Box::new(unicode::Unicode));
+ store.register_late_pass(|| Box::new(uninit_vec::UninitVec));
+ store.register_late_pass(|| Box::new(unit_hash::UnitHash));
+ store.register_late_pass(|| Box::new(unit_return_expecting_ord::UnitReturnExpectingOrd));
+ store.register_late_pass(|| Box::new(strings::StringAdd));
+ store.register_late_pass(|| Box::new(implicit_return::ImplicitReturn));
+ store.register_late_pass(|| Box::new(implicit_saturating_sub::ImplicitSaturatingSub));
+ store.register_late_pass(|| Box::new(default_numeric_fallback::DefaultNumericFallback));
+ store.register_late_pass(|| Box::new(inconsistent_struct_constructor::InconsistentStructConstructor));
+ store.register_late_pass(|| Box::new(non_octal_unix_permissions::NonOctalUnixPermissions));
+ store.register_early_pass(|| Box::new(unnecessary_self_imports::UnnecessarySelfImports));
+
+ let msrv = conf.msrv.as_ref().and_then(|s| {
+ parse_msrv(s, None, None).or_else(|| {
+ sess.err(&format!(
+ "error reading Clippy's configuration file. `{}` is not a valid Rust version",
+ s
+ ));
+ None
+ })
+ });
+
+ let avoid_breaking_exported_api = conf.avoid_breaking_exported_api;
+ let allow_expect_in_tests = conf.allow_expect_in_tests;
+ let allow_unwrap_in_tests = conf.allow_unwrap_in_tests;
+ store.register_late_pass(move || Box::new(approx_const::ApproxConstant::new(msrv)));
+ store.register_late_pass(move || {
+ Box::new(methods::Methods::new(
+ avoid_breaking_exported_api,
+ msrv,
+ allow_expect_in_tests,
+ allow_unwrap_in_tests,
+ ))
+ });
+ store.register_late_pass(move || Box::new(matches::Matches::new(msrv)));
+ store.register_early_pass(move || Box::new(manual_non_exhaustive::ManualNonExhaustiveStruct::new(msrv)));
+ store.register_late_pass(move || Box::new(manual_non_exhaustive::ManualNonExhaustiveEnum::new(msrv)));
+ store.register_late_pass(move || Box::new(manual_strip::ManualStrip::new(msrv)));
+ store.register_early_pass(move || Box::new(redundant_static_lifetimes::RedundantStaticLifetimes::new(msrv)));
+ store.register_early_pass(move || Box::new(redundant_field_names::RedundantFieldNames::new(msrv)));
+ store.register_late_pass(move || Box::new(checked_conversions::CheckedConversions::new(msrv)));
+ store.register_late_pass(move || Box::new(mem_replace::MemReplace::new(msrv)));
+ store.register_late_pass(move || Box::new(ranges::Ranges::new(msrv)));
+ store.register_late_pass(move || Box::new(from_over_into::FromOverInto::new(msrv)));
+ store.register_late_pass(move || Box::new(use_self::UseSelf::new(msrv)));
+ store.register_late_pass(move || Box::new(missing_const_for_fn::MissingConstForFn::new(msrv)));
+ store.register_late_pass(move || Box::new(needless_question_mark::NeedlessQuestionMark));
+ store.register_late_pass(move || Box::new(casts::Casts::new(msrv)));
+ store.register_early_pass(move || Box::new(unnested_or_patterns::UnnestedOrPatterns::new(msrv)));
+ store.register_late_pass(move || Box::new(map_clone::MapClone::new(msrv)));
+
+ store.register_late_pass(|| Box::new(size_of_in_element_count::SizeOfInElementCount));
+ store.register_late_pass(|| Box::new(same_name_method::SameNameMethod));
+ let max_suggested_slice_pattern_length = conf.max_suggested_slice_pattern_length;
+ store.register_late_pass(move || {
+ Box::new(index_refutable_slice::IndexRefutableSlice::new(
+ max_suggested_slice_pattern_length,
+ msrv,
+ ))
+ });
+ store.register_late_pass(|| Box::new(map_err_ignore::MapErrIgnore));
+ store.register_late_pass(|| Box::new(shadow::Shadow::default()));
+ store.register_late_pass(|| Box::new(unit_types::UnitTypes));
+ store.register_late_pass(|| Box::new(loops::Loops));
+ store.register_late_pass(|| Box::new(main_recursion::MainRecursion::default()));
+ store.register_late_pass(|| Box::new(lifetimes::Lifetimes));
+ store.register_late_pass(|| Box::new(entry::HashMapPass));
+ store.register_late_pass(|| Box::new(minmax::MinMaxPass));
+ store.register_late_pass(|| Box::new(open_options::OpenOptions));
+ store.register_late_pass(|| Box::new(zero_div_zero::ZeroDiv));
+ store.register_late_pass(|| Box::new(mutex_atomic::Mutex));
+ store.register_late_pass(|| Box::new(needless_update::NeedlessUpdate));
+ store.register_late_pass(|| Box::new(needless_borrowed_ref::NeedlessBorrowedRef));
++ store.register_late_pass(|| Box::new(borrow_deref_ref::BorrowDerefRef));
+ store.register_late_pass(|| Box::new(no_effect::NoEffect));
+ store.register_late_pass(|| Box::new(temporary_assignment::TemporaryAssignment));
+ store.register_late_pass(|| Box::new(transmute::Transmute));
+ let cognitive_complexity_threshold = conf.cognitive_complexity_threshold;
+ store.register_late_pass(move || {
+ Box::new(cognitive_complexity::CognitiveComplexity::new(
+ cognitive_complexity_threshold,
+ ))
+ });
+ let too_large_for_stack = conf.too_large_for_stack;
+ store.register_late_pass(move || Box::new(escape::BoxedLocal { too_large_for_stack }));
+ store.register_late_pass(move || Box::new(vec::UselessVec { too_large_for_stack }));
+ store.register_late_pass(|| Box::new(panic_unimplemented::PanicUnimplemented));
+ store.register_late_pass(|| Box::new(strings::StringLitAsBytes));
+ store.register_late_pass(|| Box::new(derive::Derive));
+ store.register_late_pass(|| Box::new(derivable_impls::DerivableImpls));
- store.register_late_pass(|| Box::new(arithmetic::Arithmetic::default()));
+ store.register_late_pass(|| Box::new(drop_forget_ref::DropForgetRef));
+ store.register_late_pass(|| Box::new(empty_enum::EmptyEnum));
+ store.register_late_pass(|| Box::new(absurd_extreme_comparisons::AbsurdExtremeComparisons));
+ store.register_late_pass(|| Box::new(invalid_upcast_comparisons::InvalidUpcastComparisons));
+ store.register_late_pass(|| Box::new(regex::Regex));
+ store.register_late_pass(|| Box::new(copies::CopyAndPaste));
+ store.register_late_pass(|| Box::new(copy_iterator::CopyIterator));
+ store.register_late_pass(|| Box::new(format::UselessFormat));
+ store.register_late_pass(|| Box::new(swap::Swap));
+ store.register_late_pass(|| Box::new(overflow_check_conditional::OverflowCheckConditional));
+ store.register_late_pass(|| Box::new(new_without_default::NewWithoutDefault::default()));
+ let blacklisted_names = conf.blacklisted_names.iter().cloned().collect::<FxHashSet<_>>();
+ store.register_late_pass(move || Box::new(blacklisted_name::BlacklistedName::new(blacklisted_names.clone())));
+ let too_many_arguments_threshold = conf.too_many_arguments_threshold;
+ let too_many_lines_threshold = conf.too_many_lines_threshold;
+ store.register_late_pass(move || {
+ Box::new(functions::Functions::new(
+ too_many_arguments_threshold,
+ too_many_lines_threshold,
+ ))
+ });
+ let doc_valid_idents = conf.doc_valid_idents.iter().cloned().collect::<FxHashSet<_>>();
+ store.register_late_pass(move || Box::new(doc::DocMarkdown::new(doc_valid_idents.clone())));
+ store.register_late_pass(|| Box::new(neg_multiply::NegMultiply));
+ store.register_late_pass(|| Box::new(mem_forget::MemForget));
- store.register_late_pass(|| Box::new(try_err::TryErr));
++ store.register_late_pass(|| Box::new(numeric_arithmetic::NumericArithmetic::default()));
+ store.register_late_pass(|| Box::new(assign_ops::AssignOps));
+ store.register_late_pass(|| Box::new(let_if_seq::LetIfSeq));
+ store.register_late_pass(|| Box::new(mixed_read_write_in_expression::EvalOrderDependence));
+ store.register_late_pass(|| Box::new(missing_doc::MissingDoc::new()));
+ store.register_late_pass(|| Box::new(missing_inline::MissingInline));
+ store.register_late_pass(move || Box::new(exhaustive_items::ExhaustiveItems));
+ store.register_late_pass(|| Box::new(match_result_ok::MatchResultOk));
+ store.register_late_pass(|| Box::new(partialeq_ne_impl::PartialEqNeImpl));
+ store.register_late_pass(|| Box::new(unused_io_amount::UnusedIoAmount));
+ let enum_variant_size_threshold = conf.enum_variant_size_threshold;
+ store.register_late_pass(move || Box::new(large_enum_variant::LargeEnumVariant::new(enum_variant_size_threshold)));
+ store.register_late_pass(|| Box::new(explicit_write::ExplicitWrite));
+ store.register_late_pass(|| Box::new(needless_pass_by_value::NeedlessPassByValue));
+ let pass_by_ref_or_value = pass_by_ref_or_value::PassByRefOrValue::new(
+ conf.trivial_copy_size_limit,
+ conf.pass_by_value_size_limit,
+ conf.avoid_breaking_exported_api,
+ &sess.target,
+ );
+ store.register_late_pass(move || Box::new(pass_by_ref_or_value));
+ store.register_late_pass(|| Box::new(ref_option_ref::RefOptionRef));
- store.register_late_pass(|| Box::new(match_on_vec_items::MatchOnVecItems));
+ store.register_late_pass(|| Box::new(bytecount::ByteCount));
+ store.register_late_pass(|| Box::new(infinite_iter::InfiniteIter));
+ store.register_late_pass(|| Box::new(inline_fn_without_body::InlineFnWithoutBody));
+ store.register_late_pass(|| Box::new(useless_conversion::UselessConversion::default()));
+ store.register_late_pass(|| Box::new(implicit_hasher::ImplicitHasher));
+ store.register_late_pass(|| Box::new(fallible_impl_from::FallibleImplFrom));
+ store.register_late_pass(|| Box::new(double_comparison::DoubleComparisons));
+ store.register_late_pass(|| Box::new(question_mark::QuestionMark));
+ store.register_early_pass(|| Box::new(suspicious_operation_groupings::SuspiciousOperationGroupings));
+ store.register_late_pass(|| Box::new(suspicious_trait_impl::SuspiciousImpl));
+ store.register_late_pass(|| Box::new(map_unit_fn::MapUnit));
+ store.register_late_pass(|| Box::new(inherent_impl::MultipleInherentImpl));
+ store.register_late_pass(|| Box::new(neg_cmp_op_on_partial_ord::NoNegCompOpForPartialOrd));
+ store.register_late_pass(|| Box::new(unwrap::Unwrap));
+ store.register_late_pass(|| Box::new(duration_subsec::DurationSubsec));
+ store.register_late_pass(|| Box::new(indexing_slicing::IndexingSlicing));
+ store.register_late_pass(|| Box::new(non_copy_const::NonCopyConst));
+ store.register_late_pass(|| Box::new(ptr_offset_with_cast::PtrOffsetWithCast));
+ store.register_late_pass(|| Box::new(redundant_clone::RedundantClone));
+ store.register_late_pass(|| Box::new(slow_vector_initialization::SlowVectorInit));
+ store.register_late_pass(|| Box::new(unnecessary_sort_by::UnnecessarySortBy));
+ store.register_late_pass(move || Box::new(unnecessary_wraps::UnnecessaryWraps::new(avoid_breaking_exported_api)));
+ store.register_late_pass(|| Box::new(assertions_on_constants::AssertionsOnConstants));
+ store.register_late_pass(|| Box::new(transmuting_null::TransmutingNull));
+ store.register_late_pass(|| Box::new(path_buf_push_overwrite::PathBufPushOverwrite));
+ store.register_late_pass(|| Box::new(integer_division::IntegerDivision));
+ store.register_late_pass(|| Box::new(inherent_to_string::InherentToString));
+ let max_trait_bounds = conf.max_trait_bounds;
+ store.register_late_pass(move || Box::new(trait_bounds::TraitBounds::new(max_trait_bounds)));
+ store.register_late_pass(|| Box::new(comparison_chain::ComparisonChain));
+ store.register_late_pass(|| Box::new(mut_key::MutableKeyType));
+ store.register_late_pass(|| Box::new(modulo_arithmetic::ModuloArithmetic));
+ store.register_early_pass(|| Box::new(reference::DerefAddrOf));
+ store.register_early_pass(|| Box::new(double_parens::DoubleParens));
+ store.register_late_pass(|| Box::new(format_impl::FormatImpl::new()));
+ store.register_early_pass(|| Box::new(unsafe_removed_from_name::UnsafeNameRemoval));
+ store.register_early_pass(|| Box::new(else_if_without_else::ElseIfWithoutElse));
+ store.register_early_pass(|| Box::new(int_plus_one::IntPlusOne));
+ store.register_early_pass(|| Box::new(formatting::Formatting));
+ store.register_early_pass(|| Box::new(misc_early::MiscEarlyLints));
+ store.register_early_pass(|| Box::new(redundant_closure_call::RedundantClosureCall));
+ store.register_late_pass(|| Box::new(redundant_closure_call::RedundantClosureCall));
+ store.register_early_pass(|| Box::new(unused_unit::UnusedUnit));
+ store.register_late_pass(|| Box::new(returns::Return));
+ store.register_early_pass(|| Box::new(collapsible_if::CollapsibleIf));
+ store.register_early_pass(|| Box::new(items_after_statements::ItemsAfterStatements));
+ store.register_early_pass(|| Box::new(precedence::Precedence));
+ store.register_early_pass(|| Box::new(needless_continue::NeedlessContinue));
+ store.register_early_pass(|| Box::new(redundant_else::RedundantElse));
+ store.register_late_pass(|| Box::new(create_dir::CreateDir));
+ store.register_early_pass(|| Box::new(needless_arbitrary_self_type::NeedlessArbitrarySelfType));
+ let literal_representation_lint_fraction_readability = conf.unreadable_literal_lint_fractions;
+ store.register_early_pass(move || {
+ Box::new(literal_representation::LiteralDigitGrouping::new(
+ literal_representation_lint_fraction_readability,
+ ))
+ });
+ let literal_representation_threshold = conf.literal_representation_threshold;
+ store.register_early_pass(move || {
+ Box::new(literal_representation::DecimalLiteralRepresentation::new(
+ literal_representation_threshold,
+ ))
+ });
+ let enum_variant_name_threshold = conf.enum_variant_name_threshold;
+ store.register_late_pass(move || {
+ Box::new(enum_variants::EnumVariantNames::new(
+ enum_variant_name_threshold,
+ avoid_breaking_exported_api,
+ ))
+ });
+ store.register_early_pass(|| Box::new(tabs_in_doc_comments::TabsInDocComments));
+ let upper_case_acronyms_aggressive = conf.upper_case_acronyms_aggressive;
+ store.register_late_pass(move || {
+ Box::new(upper_case_acronyms::UpperCaseAcronyms::new(
+ avoid_breaking_exported_api,
+ upper_case_acronyms_aggressive,
+ ))
+ });
+ store.register_late_pass(|| Box::new(default::Default::default()));
+ store.register_late_pass(|| Box::new(unused_self::UnusedSelf));
+ store.register_late_pass(|| Box::new(mutable_debug_assertion::DebugAssertWithMutCall));
+ store.register_late_pass(|| Box::new(exit::Exit));
+ store.register_late_pass(|| Box::new(to_digit_is_some::ToDigitIsSome));
+ let array_size_threshold = conf.array_size_threshold;
+ store.register_late_pass(move || Box::new(large_stack_arrays::LargeStackArrays::new(array_size_threshold)));
+ store.register_late_pass(move || Box::new(large_const_arrays::LargeConstArrays::new(array_size_threshold)));
+ store.register_late_pass(|| Box::new(floating_point_arithmetic::FloatingPointArithmetic));
+ store.register_early_pass(|| Box::new(as_conversions::AsConversions));
+ store.register_late_pass(|| Box::new(let_underscore::LetUnderscore));
+ store.register_early_pass(|| Box::new(single_component_path_imports::SingleComponentPathImports));
+ let max_fn_params_bools = conf.max_fn_params_bools;
+ let max_struct_bools = conf.max_struct_bools;
+ store.register_early_pass(move || {
+ Box::new(excessive_bools::ExcessiveBools::new(
+ max_struct_bools,
+ max_fn_params_bools,
+ ))
+ });
+ store.register_early_pass(|| Box::new(option_env_unwrap::OptionEnvUnwrap));
+ let warn_on_all_wildcard_imports = conf.warn_on_all_wildcard_imports;
+ store.register_late_pass(move || Box::new(wildcard_imports::WildcardImports::new(warn_on_all_wildcard_imports)));
+ store.register_late_pass(|| Box::new(verbose_file_reads::VerboseFileReads));
+ store.register_late_pass(|| Box::new(redundant_pub_crate::RedundantPubCrate::default()));
+ store.register_late_pass(|| Box::new(unnamed_address::UnnamedAddress));
+ store.register_late_pass(|| Box::new(dereference::Dereferencing::default()));
+ store.register_late_pass(|| Box::new(option_if_let_else::OptionIfLetElse));
+ store.register_late_pass(|| Box::new(future_not_send::FutureNotSend));
+ store.register_late_pass(|| Box::new(if_let_mutex::IfLetMutex));
+ store.register_late_pass(|| Box::new(if_not_else::IfNotElse));
+ store.register_late_pass(|| Box::new(equatable_if_let::PatternEquality));
+ store.register_late_pass(|| Box::new(mut_mutex_lock::MutMutexLock));
- store.register_late_pass(|| Box::new(manual_unwrap_or::ManualUnwrapOr));
+ store.register_late_pass(|| Box::new(manual_async_fn::ManualAsyncFn));
+ store.register_late_pass(|| Box::new(vec_resize_to_zero::VecResizeToZero));
+ store.register_late_pass(|| Box::new(panic_in_result_fn::PanicInResultFn));
+ let single_char_binding_names_threshold = conf.single_char_binding_names_threshold;
+ store.register_early_pass(move || {
+ Box::new(non_expressive_names::NonExpressiveNames {
+ single_char_binding_names_threshold,
+ })
+ });
+ let macro_matcher = conf.standard_macro_braces.iter().cloned().collect::<FxHashSet<_>>();
+ store.register_early_pass(move || Box::new(nonstandard_macro_braces::MacroBraces::new(¯o_matcher)));
+ store.register_late_pass(|| Box::new(macro_use::MacroUseImports::default()));
+ store.register_late_pass(|| Box::new(pattern_type_mismatch::PatternTypeMismatch));
+ store.register_late_pass(|| Box::new(stable_sort_primitive::StableSortPrimitive));
+ store.register_late_pass(|| Box::new(repeat_once::RepeatOnce));
+ store.register_late_pass(|| Box::new(unwrap_in_result::UnwrapInResult));
+ store.register_late_pass(|| Box::new(self_assignment::SelfAssignment));
- store.register_late_pass(|| Box::new(manual_map::ManualMap));
+ store.register_late_pass(|| Box::new(manual_ok_or::ManualOkOr));
+ store.register_late_pass(|| Box::new(float_equality_without_abs::FloatEqualityWithoutAbs));
+ store.register_late_pass(|| Box::new(semicolon_if_nothing_returned::SemicolonIfNothingReturned));
+ store.register_late_pass(|| Box::new(async_yields_async::AsyncYieldsAsync));
+ let disallowed_methods = conf.disallowed_methods.clone();
+ store.register_late_pass(move || Box::new(disallowed_methods::DisallowedMethods::new(disallowed_methods.clone())));
+ store.register_early_pass(|| Box::new(asm_syntax::InlineAsmX86AttSyntax));
+ store.register_early_pass(|| Box::new(asm_syntax::InlineAsmX86IntelSyntax));
+ store.register_late_pass(|| Box::new(empty_drop::EmptyDrop));
+ store.register_late_pass(|| Box::new(strings::StrToString));
+ store.register_late_pass(|| Box::new(strings::StringToString));
+ store.register_late_pass(|| Box::new(zero_sized_map_values::ZeroSizedMapValues));
+ store.register_late_pass(|| Box::new(vec_init_then_push::VecInitThenPush::default()));
+ store.register_late_pass(|| {
+ Box::new(case_sensitive_file_extension_comparisons::CaseSensitiveFileExtensionComparisons)
+ });
+ store.register_late_pass(|| Box::new(redundant_slicing::RedundantSlicing));
+ store.register_late_pass(|| Box::new(from_str_radix_10::FromStrRadix10));
- store.register_late_pass(|| Box::new(match_str_case_mismatch::MatchStrCaseMismatch));
+ store.register_late_pass(move || Box::new(if_then_some_else_none::IfThenSomeElseNone::new(msrv)));
+ store.register_late_pass(|| Box::new(bool_assert_comparison::BoolAssertComparison));
+ store.register_early_pass(move || Box::new(module_style::ModStyle));
+ store.register_late_pass(|| Box::new(unused_async::UnusedAsync));
+ let disallowed_types = conf.disallowed_types.clone();
+ store.register_late_pass(move || Box::new(disallowed_types::DisallowedTypes::new(disallowed_types.clone())));
+ let import_renames = conf.enforced_import_renames.clone();
+ store.register_late_pass(move || {
+ Box::new(missing_enforced_import_rename::ImportRename::new(
+ import_renames.clone(),
+ ))
+ });
+ let scripts = conf.allowed_scripts.clone();
+ store.register_early_pass(move || Box::new(disallowed_script_idents::DisallowedScriptIdents::new(&scripts)));
+ store.register_late_pass(|| Box::new(strlen_on_c_strings::StrlenOnCStrings));
+ store.register_late_pass(move || Box::new(self_named_constructors::SelfNamedConstructors));
+ store.register_late_pass(move || Box::new(iter_not_returning_iterator::IterNotReturningIterator));
+ store.register_late_pass(move || Box::new(manual_assert::ManualAssert));
+ let enable_raw_pointer_heuristic_for_send = conf.enable_raw_pointer_heuristic_for_send;
+ store.register_late_pass(move || {
+ Box::new(non_send_fields_in_send_ty::NonSendFieldInSendTy::new(
+ enable_raw_pointer_heuristic_for_send,
+ ))
+ });
+ store.register_late_pass(move || Box::new(undocumented_unsafe_blocks::UndocumentedUnsafeBlocks));
- store.register_late_pass(|| Box::new(significant_drop_in_scrutinee::SignificantDropInScrutinee));
- store.register_late_pass(|| Box::new(dbg_macro::DbgMacro));
+ store.register_late_pass(move || Box::new(format_args::FormatArgs));
+ store.register_late_pass(|| Box::new(trailing_empty_array::TrailingEmptyArray));
+ store.register_early_pass(|| Box::new(octal_escapes::OctalEscapes));
+ store.register_late_pass(|| Box::new(needless_late_init::NeedlessLateInit));
+ store.register_late_pass(|| Box::new(return_self_not_must_use::ReturnSelfNotMustUse));
+ store.register_late_pass(|| Box::new(init_numbered_fields::NumberedFields));
+ store.register_early_pass(|| Box::new(single_char_lifetime_names::SingleCharLifetimeNames));
+ store.register_late_pass(move || Box::new(borrow_as_ptr::BorrowAsPtr::new(msrv)));
+ store.register_late_pass(move || Box::new(manual_bits::ManualBits::new(msrv)));
+ store.register_late_pass(|| Box::new(default_union_representation::DefaultUnionRepresentation));
++ store.register_early_pass(|| Box::new(doc_link_with_quotes::DocLinkWithQuotes));
+ store.register_late_pass(|| Box::new(only_used_in_recursion::OnlyUsedInRecursion));
++ let allow_dbg_in_tests = conf.allow_dbg_in_tests;
++ store.register_late_pass(move || Box::new(dbg_macro::DbgMacro::new(allow_dbg_in_tests)));
+ let cargo_ignore_publish = conf.cargo_ignore_publish;
+ store.register_late_pass(move || {
+ Box::new(cargo::Cargo {
+ ignore_publish: cargo_ignore_publish,
+ })
+ });
+ store.register_early_pass(|| Box::new(crate_in_macro_def::CrateInMacroDef));
+ store.register_early_pass(|| Box::new(empty_structs_with_brackets::EmptyStructsWithBrackets));
+ store.register_late_pass(|| Box::new(unnecessary_owned_empty_strings::UnnecessaryOwnedEmptyStrings));
+ store.register_early_pass(|| Box::new(pub_use::PubUse));
+ store.register_late_pass(|| Box::new(format_push_string::FormatPushString));
+ store.register_late_pass(|| Box::new(bytes_count_to_len::BytesCountToLen));
+ let max_include_file_size = conf.max_include_file_size;
+ store.register_late_pass(move || Box::new(large_include_file::LargeIncludeFile::new(max_include_file_size)));
+ store.register_late_pass(|| Box::new(strings::TrimSplitWhitespace));
+ store.register_late_pass(|| Box::new(rc_clone_in_vec_init::RcCloneInVecInit));
+ store.register_early_pass(|| Box::new(duplicate_mod::DuplicateMod::default()));
++ store.register_late_pass(|| Box::new(get_first::GetFirst));
++ store.register_early_pass(|| Box::new(unused_rounding::UnusedRounding));
++ store.register_early_pass(move || Box::new(almost_complete_letter_range::AlmostCompleteLetterRange::new(msrv)));
++ store.register_late_pass(|| Box::new(swap_ptr_to_ref::SwapPtrToRef));
++ store.register_late_pass(|| Box::new(mismatching_type_param_order::TypeParamMismatch));
++ store.register_late_pass(|| Box::new(as_underscore::AsUnderscore));
+ // add lints here, do not remove this comment, it's used in `new_lint`
+}
+
+#[rustfmt::skip]
+fn register_removed_non_tool_lints(store: &mut rustc_lint::LintStore) {
+ store.register_removed(
+ "should_assert_eq",
+ "`assert!()` will be more flexible with RFC 2011",
+ );
+ store.register_removed(
+ "extend_from_slice",
+ "`.extend_from_slice(_)` is a faster way to extend a Vec by a slice",
+ );
+ store.register_removed(
+ "range_step_by_zero",
+ "`iterator.step_by(0)` panics nowadays",
+ );
+ store.register_removed(
+ "unstable_as_slice",
+ "`Vec::as_slice` has been stabilized in 1.7",
+ );
+ store.register_removed(
+ "unstable_as_mut_slice",
+ "`Vec::as_mut_slice` has been stabilized in 1.7",
+ );
+ store.register_removed(
+ "misaligned_transmute",
+ "this lint has been split into cast_ptr_alignment and transmute_ptr_to_ptr",
+ );
+ store.register_removed(
+ "assign_ops",
+ "using compound assignment operators (e.g., `+=`) is harmless",
+ );
+ store.register_removed(
+ "if_let_redundant_pattern_matching",
+ "this lint has been changed to redundant_pattern_matching",
+ );
+ store.register_removed(
+ "unsafe_vector_initialization",
+ "the replacement suggested by this lint had substantially different behavior",
+ );
+ store.register_removed(
+ "reverse_range_loop",
+ "this lint is now included in reversed_empty_ranges",
+ );
+}
+
+/// Register renamed lints.
+///
+/// Used in `./src/driver.rs`.
+pub fn register_renamed(ls: &mut rustc_lint::LintStore) {
+ for (old_name, new_name) in renamed_lints::RENAMED_LINTS {
+ ls.register_renamed(old_name, new_name);
+ }
+}
+
+// only exists to let the dogfood integration test works.
+// Don't run clippy as an executable directly
+#[allow(dead_code)]
+fn main() {
+ panic!("Please use the cargo-clippy executable");
+}
--- /dev/null
- ///
- /// // Bad
+mod empty_loop;
+mod explicit_counter_loop;
+mod explicit_into_iter_loop;
+mod explicit_iter_loop;
+mod for_kv_map;
+mod for_loops_over_fallibles;
+mod iter_next_loop;
+mod manual_flatten;
+mod manual_memcpy;
+mod missing_spin_loop;
+mod mut_range_bound;
+mod needless_collect;
+mod needless_range_loop;
+mod never_loop;
+mod same_item_push;
+mod single_element_loop;
+mod utils;
+mod while_immutable_condition;
+mod while_let_loop;
+mod while_let_on_iterator;
+
+use clippy_utils::higher;
+use rustc_hir::{Expr, ExprKind, LoopSource, Pat};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use utils::{make_iterator_snippet, IncrementVisitor, InitializeVisitor};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for for-loops that manually copy items between
+ /// slices that could be optimized by having a memcpy.
+ ///
+ /// ### Why is this bad?
+ /// It is not as fast as a memcpy.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let src = vec![1];
+ /// # let mut dst = vec![0; 65];
+ /// for i in 0..src.len() {
+ /// dst[i + 64] = src[i];
+ /// }
+ /// ```
+ /// Could be written as:
+ /// ```rust
+ /// # let src = vec![1];
+ /// # let mut dst = vec![0; 65];
+ /// dst[64..(src.len() + 64)].clone_from_slice(&src[..]);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MANUAL_MEMCPY,
+ perf,
+ "manually copying items between slices"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for looping over the range of `0..len` of some
+ /// collection just to get the values by index.
+ ///
+ /// ### Why is this bad?
+ /// Just iterating the collection itself makes the intent
+ /// more clear and is probably faster.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let vec = vec!['a', 'b', 'c'];
+ /// for i in 0..vec.len() {
+ /// println!("{}", vec[i]);
+ /// }
+ /// ```
+ /// Could be written as:
+ /// ```rust
+ /// let vec = vec!['a', 'b', 'c'];
+ /// for i in vec {
+ /// println!("{}", i);
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NEEDLESS_RANGE_LOOP,
+ style,
+ "for-looping over a range of indices where an iterator over items would do"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for loops on `x.iter()` where `&x` will do, and
+ /// suggests the latter.
+ ///
+ /// ### Why is this bad?
+ /// Readability.
+ ///
+ /// ### Known problems
+ /// False negatives. We currently only warn on some known
+ /// types.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // with `y` a `Vec` or slice:
+ /// # let y = vec![1];
+ /// for x in y.iter() {
+ /// // ..
+ /// }
+ /// ```
+ /// can be rewritten to
+ /// ```rust
+ /// # let y = vec![1];
+ /// for x in &y {
+ /// // ..
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EXPLICIT_ITER_LOOP,
+ pedantic,
+ "for-looping over `_.iter()` or `_.iter_mut()` when `&_` or `&mut _` would do"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for loops on `y.into_iter()` where `y` will do, and
+ /// suggests the latter.
+ ///
+ /// ### Why is this bad?
+ /// Readability.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let y = vec![1];
+ /// // with `y` a `Vec` or slice:
+ /// for x in y.into_iter() {
+ /// // ..
+ /// }
+ /// ```
+ /// can be rewritten to
+ /// ```rust
+ /// # let y = vec![1];
+ /// for x in y {
+ /// // ..
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EXPLICIT_INTO_ITER_LOOP,
+ pedantic,
+ "for-looping over `_.into_iter()` when `_` would do"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for loops on `x.next()`.
+ ///
+ /// ### Why is this bad?
+ /// `next()` returns either `Some(value)` if there was a
+ /// value, or `None` otherwise. The insidious thing is that `Option<_>`
+ /// implements `IntoIterator`, so that possibly one value will be iterated,
+ /// leading to some hard to find bugs. No one will want to write such code
+ /// [except to win an Underhanded Rust
+ /// Contest](https://www.reddit.com/r/rust/comments/3hb0wm/underhanded_rust_contest/cu5yuhr).
+ ///
+ /// ### Example
+ /// ```ignore
+ /// for x in y.next() {
+ /// ..
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ITER_NEXT_LOOP,
+ correctness,
+ "for-looping over `_.next()` which is probably not intended"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `for` loops over `Option` or `Result` values.
+ ///
+ /// ### Why is this bad?
+ /// Readability. This is more clearly expressed as an `if
+ /// let`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let opt = Some(1);
- /// // Good
- /// if let Some(x) = opt {
++ /// # let res: Result<i32, std::io::Error> = Ok(1);
+ /// for x in opt {
+ /// // ..
+ /// }
+ ///
- /// // or
- ///
++ /// for x in &res {
+ /// // ..
+ /// }
+ /// ```
+ ///
- ///
- /// // Bad
- /// for x in &res {
++ /// Use instead:
+ /// ```rust
++ /// # let opt = Some(1);
+ /// # let res: Result<i32, std::io::Error> = Ok(1);
- /// // Good
++ /// if let Some(x) = opt {
+ /// // ..
+ /// }
+ ///
+ /// if let Ok(x) = res {
+ /// // ..
+ /// }
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub FOR_LOOPS_OVER_FALLIBLES,
+ suspicious,
+ "for-looping over an `Option` or a `Result`, which is more clearly expressed as an `if let`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Detects `loop + match` combinations that are easier
+ /// written as a `while let` loop.
+ ///
+ /// ### Why is this bad?
+ /// The `while let` loop is usually shorter and more
+ /// readable.
+ ///
+ /// ### Known problems
+ /// Sometimes the wrong binding is displayed ([#383](https://github.com/rust-lang/rust-clippy/issues/383)).
+ ///
+ /// ### Example
+ /// ```rust,no_run
+ /// # let y = Some(1);
+ /// loop {
+ /// let x = match y {
+ /// Some(x) => x,
+ /// None => break,
+ /// };
+ /// // .. do something with x
+ /// }
+ /// // is easier written as
+ /// while let Some(x) = y {
+ /// // .. do something with x
+ /// };
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub WHILE_LET_LOOP,
+ complexity,
+ "`loop { if let { ... } else break }`, which can be written as a `while let` loop"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for functions collecting an iterator when collect
+ /// is not needed.
+ ///
+ /// ### Why is this bad?
+ /// `collect` causes the allocation of a new data structure,
+ /// when this allocation may not be needed.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let iterator = vec![1].into_iter();
+ /// let len = iterator.clone().collect::<Vec<_>>().len();
+ /// // should be
+ /// let len = iterator.count();
+ /// ```
+ #[clippy::version = "1.30.0"]
+ pub NEEDLESS_COLLECT,
+ perf,
+ "collecting an iterator when collect is not needed"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks `for` loops over slices with an explicit counter
+ /// and suggests the use of `.enumerate()`.
+ ///
+ /// ### Why is this bad?
+ /// Using `.enumerate()` makes the intent more clear,
+ /// declutters the code and may be faster in some instances.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let v = vec![1];
+ /// # fn bar(bar: usize, baz: usize) {}
+ /// let mut i = 0;
+ /// for item in &v {
+ /// bar(i, *item);
+ /// i += 1;
+ /// }
+ /// ```
+ /// Could be written as
+ /// ```rust
+ /// # let v = vec![1];
+ /// # fn bar(bar: usize, baz: usize) {}
+ /// for (i, item) in v.iter().enumerate() { bar(i, *item); }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EXPLICIT_COUNTER_LOOP,
+ complexity,
+ "for-looping with an explicit counter when `_.enumerate()` would do"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for empty `loop` expressions.
+ ///
+ /// ### Why is this bad?
+ /// These busy loops burn CPU cycles without doing
+ /// anything. It is _almost always_ a better idea to `panic!` than to have
+ /// a busy loop.
+ ///
+ /// If panicking isn't possible, think of the environment and either:
+ /// - block on something
+ /// - sleep the thread for some microseconds
+ /// - yield or pause the thread
+ ///
+ /// For `std` targets, this can be done with
+ /// [`std::thread::sleep`](https://doc.rust-lang.org/std/thread/fn.sleep.html)
+ /// or [`std::thread::yield_now`](https://doc.rust-lang.org/std/thread/fn.yield_now.html).
+ ///
+ /// For `no_std` targets, doing this is more complicated, especially because
+ /// `#[panic_handler]`s can't panic. To stop/pause the thread, you will
+ /// probably need to invoke some target-specific intrinsic. Examples include:
+ /// - [`x86_64::instructions::hlt`](https://docs.rs/x86_64/0.12.2/x86_64/instructions/fn.hlt.html)
+ /// - [`cortex_m::asm::wfi`](https://docs.rs/cortex-m/0.6.3/cortex_m/asm/fn.wfi.html)
+ ///
+ /// ### Example
+ /// ```no_run
+ /// loop {}
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EMPTY_LOOP,
+ suspicious,
+ "empty `loop {}`, which should block or sleep"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `while let` expressions on iterators.
+ ///
+ /// ### Why is this bad?
+ /// Readability. A simple `for` loop is shorter and conveys
+ /// the intent better.
+ ///
+ /// ### Example
+ /// ```ignore
+ /// while let Some(val) = iter() {
+ /// ..
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub WHILE_LET_ON_ITERATOR,
+ style,
+ "using a `while let` loop instead of a for loop on an iterator"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for iterating a map (`HashMap` or `BTreeMap`) and
+ /// ignoring either the keys or values.
+ ///
+ /// ### Why is this bad?
+ /// Readability. There are `keys` and `values` methods that
+ /// can be used to express that don't need the values or keys.
+ ///
+ /// ### Example
+ /// ```ignore
+ /// for (k, _) in &map {
+ /// ..
+ /// }
+ /// ```
+ ///
+ /// could be replaced by
+ ///
+ /// ```ignore
+ /// for k in map.keys() {
+ /// ..
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub FOR_KV_MAP,
+ style,
+ "looping on a map using `iter` when `keys` or `values` would do"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for loops that will always `break`, `return` or
+ /// `continue` an outer loop.
+ ///
+ /// ### Why is this bad?
+ /// This loop never loops, all it does is obfuscating the
+ /// code.
+ ///
+ /// ### Example
+ /// ```rust
+ /// loop {
+ /// ..;
+ /// break;
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NEVER_LOOP,
+ correctness,
+ "any loop that will always `break` or `return`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for loops which have a range bound that is a mutable variable
+ ///
+ /// ### Why is this bad?
+ /// One might think that modifying the mutable variable changes the loop bounds
+ ///
+ /// ### Known problems
+ /// False positive when mutation is followed by a `break`, but the `break` is not immediately
+ /// after the mutation:
+ ///
+ /// ```rust
+ /// let mut x = 5;
+ /// for _ in 0..x {
+ /// x += 1; // x is a range bound that is mutated
+ /// ..; // some other expression
+ /// break; // leaves the loop, so mutation is not an issue
+ /// }
+ /// ```
+ ///
+ /// False positive on nested loops ([#6072](https://github.com/rust-lang/rust-clippy/issues/6072))
+ ///
+ /// ### Example
+ /// ```rust
+ /// let mut foo = 42;
+ /// for i in 0..foo {
+ /// foo -= 1;
+ /// println!("{}", i); // prints numbers from 0 to 42, not 0 to 21
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MUT_RANGE_BOUND,
+ suspicious,
+ "for loop over a range where one of the bounds is a mutable variable"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks whether variables used within while loop condition
+ /// can be (and are) mutated in the body.
+ ///
+ /// ### Why is this bad?
+ /// If the condition is unchanged, entering the body of the loop
+ /// will lead to an infinite loop.
+ ///
+ /// ### Known problems
+ /// If the `while`-loop is in a closure, the check for mutation of the
+ /// condition variables in the body can cause false negatives. For example when only `Upvar` `a` is
+ /// in the condition and only `Upvar` `b` gets mutated in the body, the lint will not trigger.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let i = 0;
+ /// while i > 10 {
+ /// println!("let me loop forever!");
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub WHILE_IMMUTABLE_CONDITION,
+ correctness,
+ "variables used within while expression are not mutated in the body"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks whether a for loop is being used to push a constant
+ /// value into a Vec.
+ ///
+ /// ### Why is this bad?
+ /// This kind of operation can be expressed more succinctly with
+ /// `vec![item;SIZE]` or `vec.resize(NEW_SIZE, item)` and using these alternatives may also
+ /// have better performance.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let item1 = 2;
+ /// let item2 = 3;
+ /// let mut vec: Vec<u8> = Vec::new();
+ /// for _ in 0..20 {
+ /// vec.push(item1);
+ /// }
+ /// for _ in 0..30 {
+ /// vec.push(item2);
+ /// }
+ /// ```
+ /// could be written as
+ /// ```rust
+ /// let item1 = 2;
+ /// let item2 = 3;
+ /// let mut vec: Vec<u8> = vec![item1; 20];
+ /// vec.resize(20 + 30, item2);
+ /// ```
+ #[clippy::version = "1.47.0"]
+ pub SAME_ITEM_PUSH,
+ style,
+ "the same item is pushed inside of a for loop"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks whether a for loop has a single element.
+ ///
+ /// ### Why is this bad?
+ /// There is no reason to have a loop of a
+ /// single element.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let item1 = 2;
+ /// for item in &[item1] {
+ /// println!("{}", item);
+ /// }
+ /// ```
+ /// could be written as
+ /// ```rust
+ /// let item1 = 2;
+ /// let item = &item1;
+ /// println!("{}", item);
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub SINGLE_ELEMENT_LOOP,
+ complexity,
+ "there is no reason to have a single element loop"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Check for unnecessary `if let` usage in a for loop
+ /// where only the `Some` or `Ok` variant of the iterator element is used.
+ ///
+ /// ### Why is this bad?
+ /// It is verbose and can be simplified
+ /// by first calling the `flatten` method on the `Iterator`.
+ ///
+ /// ### Example
+ ///
+ /// ```rust
+ /// let x = vec![Some(1), Some(2), Some(3)];
+ /// for n in x {
+ /// if let Some(n) = n {
+ /// println!("{}", n);
+ /// }
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let x = vec![Some(1), Some(2), Some(3)];
+ /// for n in x.into_iter().flatten() {
+ /// println!("{}", n);
+ /// }
+ /// ```
+ #[clippy::version = "1.52.0"]
+ pub MANUAL_FLATTEN,
+ complexity,
+ "for loops over `Option`s or `Result`s with a single expression can be simplified"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Check for empty spin loops
+ ///
+ /// ### Why is this bad?
+ /// The loop body should have something like `thread::park()` or at least
+ /// `std::hint::spin_loop()` to avoid needlessly burning cycles and conserve
+ /// energy. Perhaps even better use an actual lock, if possible.
+ ///
+ /// ### Known problems
+ /// This lint doesn't currently trigger on `while let` or
+ /// `loop { match .. { .. } }` loops, which would be considered idiomatic in
+ /// combination with e.g. `AtomicBool::compare_exchange_weak`.
+ ///
+ /// ### Example
+ ///
+ /// ```ignore
+ /// use core::sync::atomic::{AtomicBool, Ordering};
+ /// let b = AtomicBool::new(true);
+ /// // give a ref to `b` to another thread,wait for it to become false
+ /// while b.load(Ordering::Acquire) {};
+ /// ```
+ /// Use instead:
+ /// ```rust,no_run
+ ///# use core::sync::atomic::{AtomicBool, Ordering};
+ ///# let b = AtomicBool::new(true);
+ /// while b.load(Ordering::Acquire) {
+ /// std::hint::spin_loop()
+ /// }
+ /// ```
+ #[clippy::version = "1.59.0"]
+ pub MISSING_SPIN_LOOP,
+ perf,
+ "An empty busy waiting loop"
+}
+
+declare_lint_pass!(Loops => [
+ MANUAL_MEMCPY,
+ MANUAL_FLATTEN,
+ NEEDLESS_RANGE_LOOP,
+ EXPLICIT_ITER_LOOP,
+ EXPLICIT_INTO_ITER_LOOP,
+ ITER_NEXT_LOOP,
+ FOR_LOOPS_OVER_FALLIBLES,
+ WHILE_LET_LOOP,
+ NEEDLESS_COLLECT,
+ EXPLICIT_COUNTER_LOOP,
+ EMPTY_LOOP,
+ WHILE_LET_ON_ITERATOR,
+ FOR_KV_MAP,
+ NEVER_LOOP,
+ MUT_RANGE_BOUND,
+ WHILE_IMMUTABLE_CONDITION,
+ SAME_ITEM_PUSH,
+ SINGLE_ELEMENT_LOOP,
+ MISSING_SPIN_LOOP,
+]);
+
+impl<'tcx> LateLintPass<'tcx> for Loops {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ let for_loop = higher::ForLoop::hir(expr);
+ if let Some(higher::ForLoop {
+ pat,
+ arg,
+ body,
+ loop_id,
+ span,
+ }) = for_loop
+ {
+ // we don't want to check expanded macros
+ // this check is not at the top of the function
+ // since higher::for_loop expressions are marked as expansions
+ if body.span.from_expansion() {
+ return;
+ }
+ check_for_loop(cx, pat, arg, body, expr, span);
+ if let ExprKind::Block(block, _) = body.kind {
+ never_loop::check(cx, block, loop_id, span, for_loop.as_ref());
+ }
+ }
+
+ // we don't want to check expanded macros
+ if expr.span.from_expansion() {
+ return;
+ }
+
+ // check for never_loop
+ if let ExprKind::Loop(block, ..) = expr.kind {
+ never_loop::check(cx, block, expr.hir_id, expr.span, None);
+ }
+
+ // check for `loop { if let {} else break }` that could be `while let`
+ // (also matches an explicit "match" instead of "if let")
+ // (even if the "match" or "if let" is used for declaration)
+ if let ExprKind::Loop(block, _, LoopSource::Loop, _) = expr.kind {
+ // also check for empty `loop {}` statements, skipping those in #[panic_handler]
+ empty_loop::check(cx, expr, block);
+ while_let_loop::check(cx, expr, block);
+ }
+
+ while_let_on_iterator::check(cx, expr);
+
+ if let Some(higher::While { condition, body }) = higher::While::hir(expr) {
+ while_immutable_condition::check(cx, condition, body);
+ missing_spin_loop::check(cx, condition, body);
+ }
+
+ needless_collect::check(expr, cx);
+ }
+}
+
+fn check_for_loop<'tcx>(
+ cx: &LateContext<'tcx>,
+ pat: &'tcx Pat<'_>,
+ arg: &'tcx Expr<'_>,
+ body: &'tcx Expr<'_>,
+ expr: &'tcx Expr<'_>,
+ span: Span,
+) {
+ let is_manual_memcpy_triggered = manual_memcpy::check(cx, pat, arg, body, expr);
+ if !is_manual_memcpy_triggered {
+ needless_range_loop::check(cx, pat, arg, body, expr);
+ explicit_counter_loop::check(cx, pat, arg, body, expr);
+ }
+ check_for_loop_arg(cx, pat, arg);
+ for_kv_map::check(cx, pat, arg, body);
+ mut_range_bound::check(cx, arg, body);
+ single_element_loop::check(cx, pat, arg, body, expr);
+ same_item_push::check(cx, pat, arg, body, expr);
+ manual_flatten::check(cx, pat, arg, body, span);
+}
+
+fn check_for_loop_arg(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>) {
+ let mut next_loop_linted = false; // whether or not ITER_NEXT_LOOP lint was used
+
+ if let ExprKind::MethodCall(method, [self_arg], _) = arg.kind {
+ let method_name = method.ident.as_str();
+ // check for looping over x.iter() or x.iter_mut(), could use &x or &mut x
+ match method_name {
+ "iter" | "iter_mut" => explicit_iter_loop::check(cx, self_arg, arg, method_name),
+ "into_iter" => {
+ explicit_iter_loop::check(cx, self_arg, arg, method_name);
+ explicit_into_iter_loop::check(cx, self_arg, arg);
+ },
+ "next" => {
+ next_loop_linted = iter_next_loop::check(cx, arg);
+ },
+ _ => {},
+ }
+ }
+
+ if !next_loop_linted {
+ for_loops_over_fallibles::check(cx, pat, arg);
+ }
+}
--- /dev/null
- use clippy_utils::{
- contains_name, higher, is_integer_const, match_trait_method, paths, sugg, SpanlessEq,
- };
+use super::NEEDLESS_RANGE_LOOP;
+use clippy_utils::diagnostics::{multispan_sugg, span_lint_and_then};
+use clippy_utils::source::snippet;
+use clippy_utils::ty::has_iter_method;
+use clippy_utils::visitors::is_local_used;
- if let Some(higher::Range { start: Some(start), ref end, limits }) = higher::Range::hir(arg) {
++use clippy_utils::{contains_name, higher, is_integer_const, match_trait_method, paths, sugg, SpanlessEq};
+use if_chain::if_chain;
+use rustc_ast::ast;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::intravisit::{walk_expr, Visitor};
+use rustc_hir::{BinOpKind, BorrowKind, Expr, ExprKind, HirId, Mutability, Pat, PatKind, QPath};
+use rustc_lint::LateContext;
+use rustc_middle::middle::region;
+use rustc_middle::ty::{self, Ty};
+use rustc_span::symbol::{sym, Symbol};
+use std::iter::{self, Iterator};
+use std::mem;
+
+/// Checks for looping over a range and then indexing a sequence with it.
+/// The iteratee must be a range literal.
+#[expect(clippy::too_many_lines)]
+pub(super) fn check<'tcx>(
+ cx: &LateContext<'tcx>,
+ pat: &'tcx Pat<'_>,
+ arg: &'tcx Expr<'_>,
+ body: &'tcx Expr<'_>,
+ expr: &'tcx Expr<'_>,
+) {
- if is_len_call(end, indexed) || is_end_eq_array_len(cx, end, limits, indexed_ty)
- {
++ if let Some(higher::Range {
++ start: Some(start),
++ ref end,
++ limits,
++ }) = higher::Range::hir(arg)
++ {
+ // the var must be a single name
+ if let PatKind::Binding(_, canonical_id, ident, _) = pat.kind {
+ let mut visitor = VarVisitor {
+ cx,
+ var: canonical_id,
+ indexed_mut: FxHashSet::default(),
+ indexed_indirectly: FxHashMap::default(),
+ indexed_directly: FxHashMap::default(),
+ referenced: FxHashSet::default(),
+ nonindex: false,
+ prefer_mutable: false,
+ };
+ walk_expr(&mut visitor, body);
+
+ // linting condition: we only indexed one variable, and indexed it directly
+ if visitor.indexed_indirectly.is_empty() && visitor.indexed_directly.len() == 1 {
+ let (indexed, (indexed_extent, indexed_ty)) = visitor
+ .indexed_directly
+ .into_iter()
+ .next()
+ .expect("already checked that we have exactly 1 element");
+
+ // ensure that the indexed variable was declared before the loop, see #601
+ if let Some(indexed_extent) = indexed_extent {
+ let parent_def_id = cx.tcx.hir().get_parent_item(expr.hir_id);
+ let region_scope_tree = cx.tcx.region_scope_tree(parent_def_id);
+ let pat_extent = region_scope_tree.var_scope(pat.hir_id.local_id).unwrap();
+ if region_scope_tree.is_subscope_of(indexed_extent, pat_extent) {
+ return;
+ }
+ }
+
+ // don't lint if the container that is indexed does not have .iter() method
+ let has_iter = has_iter_method(cx, indexed_ty);
+ if has_iter.is_none() {
+ return;
+ }
+
+ // don't lint if the container that is indexed into is also used without
+ // indexing
+ if visitor.referenced.contains(&indexed) {
+ return;
+ }
+
+ let starts_at_zero = is_integer_const(cx, start, 0);
+
+ let skip = if starts_at_zero {
+ String::new()
+ } else if visitor.indexed_mut.contains(&indexed) && contains_name(indexed, start) {
+ return;
+ } else {
+ format!(".skip({})", snippet(cx, start.span, ".."))
+ };
+
+ let mut end_is_start_plus_val = false;
+
+ let take = if let Some(end) = *end {
+ let mut take_expr = end;
+
+ if let ExprKind::Binary(ref op, left, right) = end.kind {
+ if op.node == BinOpKind::Add {
+ let start_equal_left = SpanlessEq::new(cx).eq_expr(start, left);
+ let start_equal_right = SpanlessEq::new(cx).eq_expr(start, right);
+
+ if start_equal_left {
+ take_expr = right;
+ } else if start_equal_right {
+ take_expr = left;
+ }
+
+ end_is_start_plus_val = start_equal_left | start_equal_right;
+ }
+ }
+
- } else if visitor.indexed_mut.contains(&indexed)
- && contains_name(indexed, take_expr)
- {
++ if is_len_call(end, indexed) || is_end_eq_array_len(cx, end, limits, indexed_ty) {
+ String::new()
- }
++ } else if visitor.indexed_mut.contains(&indexed) && contains_name(indexed, take_expr) {
+ return;
+ } else {
+ match limits {
+ ast::RangeLimits::Closed => {
+ let take_expr = sugg::Sugg::hir(cx, take_expr, "<count>");
+ format!(".take({})", take_expr + sugg::ONE)
- }
++ },
+ ast::RangeLimits::HalfOpen => {
+ format!(".take({})", snippet(cx, take_expr.span, ".."))
- &format!(
- "the loop variable `{}` is used to index `{}`",
- ident.name, indexed
- ),
++ },
+ }
+ }
+ } else {
+ String::new()
+ };
+
+ let (ref_mut, method) = if visitor.indexed_mut.contains(&indexed) {
+ ("mut ", "iter_mut")
+ } else {
+ ("", "iter")
+ };
+
+ let take_is_empty = take.is_empty();
+ let mut method_1 = take;
+ let mut method_2 = skip;
+
+ if end_is_start_plus_val {
+ mem::swap(&mut method_1, &mut method_2);
+ }
+
+ if visitor.nonindex {
+ span_lint_and_then(
+ cx,
+ NEEDLESS_RANGE_LOOP,
+ arg.span,
- format!(
- "{}.{}().enumerate(){}{}",
- indexed, method, method_1, method_2
- ),
++ &format!("the loop variable `{}` is used to index `{}`", ident.name, indexed),
+ |diag| {
+ multispan_sugg(
+ diag,
+ "consider using an iterator",
+ vec![
+ (pat.span, format!("({}, <item>)", ident.name)),
+ (
+ arg.span,
- &format!(
- "the loop variable `{}` is only used to index `{}`",
- ident.name, indexed
- ),
++ format!("{}.{}().enumerate(){}{}", indexed, method, method_1, method_2),
+ ),
+ ],
+ );
+ },
+ );
+ } else {
+ let repl = if starts_at_zero && take_is_empty {
+ format!("&{}{}", ref_mut, indexed)
+ } else {
+ format!("{}.{}(){}{}", indexed, method, method_1, method_2)
+ };
+
+ span_lint_and_then(
+ cx,
+ NEEDLESS_RANGE_LOOP,
+ arg.span,
- fn check(
- &mut self,
- idx: &'tcx Expr<'_>,
- seqexpr: &'tcx Expr<'_>,
- expr: &'tcx Expr<'_>,
- ) -> bool {
++ &format!("the loop variable `{}` is only used to index `{}`", ident.name, indexed),
+ |diag| {
+ multispan_sugg(
+ diag,
+ "consider using an iterator",
+ vec![(pat.span, "<item>".to_string()), (arg.span, repl)],
+ );
+ },
+ );
+ }
+ }
+ }
+ }
+}
+
+fn is_len_call(expr: &Expr<'_>, var: Symbol) -> bool {
+ if_chain! {
+ if let ExprKind::MethodCall(method, len_args, _) = expr.kind;
+ if len_args.len() == 1;
+ if method.ident.name == sym::len;
+ if let ExprKind::Path(QPath::Resolved(_, path)) = len_args[0].kind;
+ if path.segments.len() == 1;
+ if path.segments[0].ident.name == var;
+ then {
+ return true;
+ }
+ }
+
+ false
+}
+
+fn is_end_eq_array_len<'tcx>(
+ cx: &LateContext<'tcx>,
+ end: &Expr<'_>,
+ limits: ast::RangeLimits,
+ indexed_ty: Ty<'tcx>,
+) -> bool {
+ if_chain! {
+ if let ExprKind::Lit(ref lit) = end.kind;
+ if let ast::LitKind::Int(end_int, _) = lit.node;
+ if let ty::Array(_, arr_len_const) = indexed_ty.kind();
+ if let Some(arr_len) = arr_len_const.try_eval_usize(cx.tcx, cx.param_env);
+ then {
+ return match limits {
+ ast::RangeLimits::Closed => end_int + 1 >= arr_len.into(),
+ ast::RangeLimits::HalfOpen => end_int >= arr_len.into(),
+ };
+ }
+ }
+
+ false
+}
+
+struct VarVisitor<'a, 'tcx> {
+ /// context reference
+ cx: &'a LateContext<'tcx>,
+ /// var name to look for as index
+ var: HirId,
+ /// indexed variables that are used mutably
+ indexed_mut: FxHashSet<Symbol>,
+ /// indirectly indexed variables (`v[(i + 4) % N]`), the extend is `None` for global
+ indexed_indirectly: FxHashMap<Symbol, Option<region::Scope>>,
+ /// subset of `indexed` of vars that are indexed directly: `v[i]`
+ /// this will not contain cases like `v[calc_index(i)]` or `v[(i + 4) % N]`
+ indexed_directly: FxHashMap<Symbol, (Option<region::Scope>, Ty<'tcx>)>,
+ /// Any names that are used outside an index operation.
+ /// Used to detect things like `&mut vec` used together with `vec[i]`
+ referenced: FxHashSet<Symbol>,
+ /// has the loop variable been used in expressions other than the index of
+ /// an index op?
+ nonindex: bool,
+ /// Whether we are inside the `$` in `&mut $` or `$ = foo` or `$.bar`, where bar
+ /// takes `&mut self`
+ prefer_mutable: bool,
+}
+
+impl<'a, 'tcx> VarVisitor<'a, 'tcx> {
- }
++ fn check(&mut self, idx: &'tcx Expr<'_>, seqexpr: &'tcx Expr<'_>, expr: &'tcx Expr<'_>) -> bool {
+ if_chain! {
+ // the indexed container is referenced by a name
+ if let ExprKind::Path(ref seqpath) = seqexpr.kind;
+ if let QPath::Resolved(None, seqvar) = *seqpath;
+ if seqvar.segments.len() == 1;
+ if is_local_used(self.cx, idx, self.var);
+ then {
+ if self.prefer_mutable {
+ self.indexed_mut.insert(seqvar.segments[0].ident.name);
+ }
+ let index_used_directly = matches!(idx.kind, ExprKind::Path(_));
+ let res = self.cx.qpath_res(seqpath, seqexpr.hir_id);
+ match res {
+ Res::Local(hir_id) => {
+ let parent_def_id = self.cx.tcx.hir().get_parent_item(expr.hir_id);
+ let extent = self.cx
+ .tcx
+ .region_scope_tree(parent_def_id)
+ .var_scope(hir_id.local_id)
+ .unwrap();
+ if index_used_directly {
+ self.indexed_directly.insert(
+ seqvar.segments[0].ident.name,
+ (Some(extent), self.cx.typeck_results().node_type(seqexpr.hir_id)),
+ );
+ } else {
+ self.indexed_indirectly.insert(seqvar.segments[0].ident.name, Some(extent));
+ }
+ return false; // no need to walk further *on the variable*
+ }
+ Res::Def(DefKind::Static (_)| DefKind::Const, ..) => {
+ if index_used_directly {
+ self.indexed_directly.insert(
+ seqvar.segments[0].ident.name,
+ (None, self.cx.typeck_results().node_type(seqexpr.hir_id)),
+ );
+ } else {
+ self.indexed_indirectly.insert(seqvar.segments[0].ident.name, None);
+ }
+ return false; // no need to walk further *on the variable*
+ }
+ _ => (),
+ }
+ }
+ }
+ true
+ }
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for VarVisitor<'a, 'tcx> {
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ // a range index op
+ if let ExprKind::MethodCall(meth, [args_0, args_1, ..], _) = &expr.kind;
+ if (meth.ident.name == sym::index && match_trait_method(self.cx, expr, &paths::INDEX))
+ || (meth.ident.name == sym::index_mut && match_trait_method(self.cx, expr, &paths::INDEX_MUT));
+ if !self.check(args_1, args_0, expr);
+ then { return }
+ }
+
+ if_chain! {
+ // an index op
+ if let ExprKind::Index(seqexpr, idx) = expr.kind;
+ if !self.check(idx, seqexpr, expr);
+ then { return }
+ }
+
+ if_chain! {
+ // directly using a variable
+ if let ExprKind::Path(QPath::Resolved(None, path)) = expr.kind;
+ if let Res::Local(local_id) = path.res;
+ then {
+ if local_id == self.var {
+ self.nonindex = true;
+ } else {
+ // not the correct variable, but still a variable
+ self.referenced.insert(path.segments[0].ident.name);
+ }
+ }
+ }
+
+ let old = self.prefer_mutable;
+ match expr.kind {
+ ExprKind::AssignOp(_, lhs, rhs) | ExprKind::Assign(lhs, rhs, _) => {
+ self.prefer_mutable = true;
+ self.visit_expr(lhs);
+ self.prefer_mutable = false;
+ self.visit_expr(rhs);
- }
++ },
+ ExprKind::AddrOf(BorrowKind::Ref, mutbl, expr) => {
+ if mutbl == Mutability::Mut {
+ self.prefer_mutable = true;
+ }
+ self.visit_expr(expr);
- }
++ },
+ ExprKind::Call(f, args) => {
+ self.visit_expr(f);
+ for expr in args {
+ let ty = self.cx.typeck_results().expr_ty_adjusted(expr);
+ self.prefer_mutable = false;
+ if let ty::Ref(_, _, mutbl) = *ty.kind() {
+ if mutbl == Mutability::Mut {
+ self.prefer_mutable = true;
+ }
+ }
+ self.visit_expr(expr);
+ }
- for (ty, expr) in iter::zip(self.cx.tcx.fn_sig(def_id).inputs().skip_binder(), args)
- {
++ },
+ ExprKind::MethodCall(_, args, _) => {
+ let def_id = self.cx.typeck_results().type_dependent_def_id(expr.hir_id).unwrap();
- }
++ for (ty, expr) in iter::zip(self.cx.tcx.fn_sig(def_id).inputs().skip_binder(), args) {
+ self.prefer_mutable = false;
+ if let ty::Ref(_, _, mutbl) = *ty.kind() {
+ if mutbl == Mutability::Mut {
+ self.prefer_mutable = true;
+ }
+ }
+ self.visit_expr(expr);
+ }
- }
++ },
+ ExprKind::Closure(_, _, body_id, ..) => {
+ let body = self.cx.tcx.hir().body(body_id);
+ self.visit_expr(&body.value);
++ },
+ _ => walk_expr(self, expr),
+ }
+ self.prefer_mutable = old;
+ }
+}
--- /dev/null
- let arms = never_loop_expr_branch(&mut arms.iter().map(|a| &*a.body), main_loop_id);
+use super::utils::make_iterator_snippet;
+use super::NEVER_LOOP;
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::higher::ForLoop;
+use clippy_utils::source::snippet;
+use rustc_errors::Applicability;
+use rustc_hir::{Block, Expr, ExprKind, HirId, InlineAsmOperand, Pat, Stmt, StmtKind};
+use rustc_lint::LateContext;
+use rustc_span::Span;
+use std::iter::{once, Iterator};
+
+pub(super) fn check(
+ cx: &LateContext<'_>,
+ block: &Block<'_>,
+ loop_id: HirId,
+ span: Span,
+ for_loop: Option<&ForLoop<'_>>,
+) {
+ match never_loop_block(block, loop_id) {
+ NeverLoopResult::AlwaysBreak => {
+ span_lint_and_then(cx, NEVER_LOOP, span, "this loop never actually loops", |diag| {
+ if let Some(ForLoop {
+ arg: iterator,
+ pat,
+ span: for_span,
+ ..
+ }) = for_loop
+ {
+ // Suggests using an `if let` instead. This is `Unspecified` because the
+ // loop may (probably) contain `break` statements which would be invalid
+ // in an `if let`.
+ diag.span_suggestion_verbose(
+ for_span.with_hi(iterator.span.hi()),
+ "if you need the first element of the iterator, try writing",
+ for_to_if_let_sugg(cx, iterator, pat),
+ Applicability::Unspecified,
+ );
+ }
+ });
+ },
+ NeverLoopResult::MayContinueMainLoop | NeverLoopResult::Otherwise => (),
+ }
+}
+
+enum NeverLoopResult {
+ // A break/return always get triggered but not necessarily for the main loop.
+ AlwaysBreak,
+ // A continue may occur for the main loop.
+ MayContinueMainLoop,
+ Otherwise,
+}
+
+#[must_use]
+fn absorb_break(arg: &NeverLoopResult) -> NeverLoopResult {
+ match *arg {
+ NeverLoopResult::AlwaysBreak | NeverLoopResult::Otherwise => NeverLoopResult::Otherwise,
+ NeverLoopResult::MayContinueMainLoop => NeverLoopResult::MayContinueMainLoop,
+ }
+}
+
+// Combine two results for parts that are called in order.
+#[must_use]
+fn combine_seq(first: NeverLoopResult, second: NeverLoopResult) -> NeverLoopResult {
+ match first {
+ NeverLoopResult::AlwaysBreak | NeverLoopResult::MayContinueMainLoop => first,
+ NeverLoopResult::Otherwise => second,
+ }
+}
+
+// Combine two results where both parts are called but not necessarily in order.
+#[must_use]
+fn combine_both(left: NeverLoopResult, right: NeverLoopResult) -> NeverLoopResult {
+ match (left, right) {
+ (NeverLoopResult::MayContinueMainLoop, _) | (_, NeverLoopResult::MayContinueMainLoop) => {
+ NeverLoopResult::MayContinueMainLoop
+ },
+ (NeverLoopResult::AlwaysBreak, _) | (_, NeverLoopResult::AlwaysBreak) => NeverLoopResult::AlwaysBreak,
+ (NeverLoopResult::Otherwise, NeverLoopResult::Otherwise) => NeverLoopResult::Otherwise,
+ }
+}
+
+// Combine two results where only one of the part may have been executed.
+#[must_use]
+fn combine_branches(b1: NeverLoopResult, b2: NeverLoopResult) -> NeverLoopResult {
+ match (b1, b2) {
+ (NeverLoopResult::AlwaysBreak, NeverLoopResult::AlwaysBreak) => NeverLoopResult::AlwaysBreak,
+ (NeverLoopResult::MayContinueMainLoop, _) | (_, NeverLoopResult::MayContinueMainLoop) => {
+ NeverLoopResult::MayContinueMainLoop
+ },
+ (NeverLoopResult::Otherwise, _) | (_, NeverLoopResult::Otherwise) => NeverLoopResult::Otherwise,
+ }
+}
+
+fn never_loop_block(block: &Block<'_>, main_loop_id: HirId) -> NeverLoopResult {
+ let mut iter = block.stmts.iter().filter_map(stmt_to_expr).chain(block.expr);
+ never_loop_expr_seq(&mut iter, main_loop_id)
+}
+
+fn never_loop_expr_seq<'a, T: Iterator<Item = &'a Expr<'a>>>(es: &mut T, main_loop_id: HirId) -> NeverLoopResult {
+ es.map(|e| never_loop_expr(e, main_loop_id))
+ .fold(NeverLoopResult::Otherwise, combine_seq)
+}
+
+fn stmt_to_expr<'tcx>(stmt: &Stmt<'tcx>) -> Option<&'tcx Expr<'tcx>> {
+ match stmt.kind {
+ StmtKind::Semi(e, ..) | StmtKind::Expr(e, ..) => Some(e),
+ StmtKind::Local(local) => local.init,
+ StmtKind::Item(..) => None,
+ }
+}
+
+fn never_loop_expr(expr: &Expr<'_>, main_loop_id: HirId) -> NeverLoopResult {
+ match expr.kind {
+ ExprKind::Box(e)
+ | ExprKind::Unary(_, e)
+ | ExprKind::Cast(e, _)
+ | ExprKind::Type(e, _)
+ | ExprKind::Field(e, _)
+ | ExprKind::AddrOf(_, _, e)
+ | ExprKind::Struct(_, _, Some(e))
+ | ExprKind::Repeat(e, _)
+ | ExprKind::DropTemps(e) => never_loop_expr(e, main_loop_id),
+ ExprKind::Let(let_expr) => never_loop_expr(let_expr.init, main_loop_id),
+ ExprKind::Array(es) | ExprKind::MethodCall(_, es, _) | ExprKind::Tup(es) => {
+ never_loop_expr_all(&mut es.iter(), main_loop_id)
+ },
+ ExprKind::Call(e, es) => never_loop_expr_all(&mut once(e).chain(es.iter()), main_loop_id),
+ ExprKind::Binary(_, e1, e2)
+ | ExprKind::Assign(e1, e2, _)
+ | ExprKind::AssignOp(_, e1, e2)
+ | ExprKind::Index(e1, e2) => never_loop_expr_all(&mut [e1, e2].iter().copied(), main_loop_id),
+ ExprKind::Loop(b, _, _, _) => {
+ // Break can come from the inner loop so remove them.
+ absorb_break(&never_loop_block(b, main_loop_id))
+ },
+ ExprKind::If(e, e2, e3) => {
+ let e1 = never_loop_expr(e, main_loop_id);
+ let e2 = never_loop_expr(e2, main_loop_id);
+ let e3 = e3
+ .as_ref()
+ .map_or(NeverLoopResult::Otherwise, |e| never_loop_expr(e, main_loop_id));
+ combine_seq(e1, combine_branches(e2, e3))
+ },
+ ExprKind::Match(e, arms, _) => {
+ let e = never_loop_expr(e, main_loop_id);
+ if arms.is_empty() {
+ e
+ } else {
++ let arms = never_loop_expr_branch(&mut arms.iter().map(|a| a.body), main_loop_id);
+ combine_seq(e, arms)
+ }
+ },
+ ExprKind::Block(b, _) => never_loop_block(b, main_loop_id),
+ ExprKind::Continue(d) => {
+ let id = d
+ .target_id
+ .expect("target ID can only be missing in the presence of compilation errors");
+ if id == main_loop_id {
+ NeverLoopResult::MayContinueMainLoop
+ } else {
+ NeverLoopResult::AlwaysBreak
+ }
+ },
+ ExprKind::Break(_, e) | ExprKind::Ret(e) => e.as_ref().map_or(NeverLoopResult::AlwaysBreak, |e| {
+ combine_seq(never_loop_expr(e, main_loop_id), NeverLoopResult::AlwaysBreak)
+ }),
+ ExprKind::InlineAsm(asm) => asm
+ .operands
+ .iter()
+ .map(|(o, _)| match o {
+ InlineAsmOperand::In { expr, .. } | InlineAsmOperand::InOut { expr, .. } => {
+ never_loop_expr(expr, main_loop_id)
+ },
+ InlineAsmOperand::Out { expr, .. } => never_loop_expr_all(&mut expr.iter(), main_loop_id),
+ InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => {
+ never_loop_expr_all(&mut once(in_expr).chain(out_expr.iter()), main_loop_id)
+ },
+ InlineAsmOperand::Const { .. }
+ | InlineAsmOperand::SymFn { .. }
+ | InlineAsmOperand::SymStatic { .. } => NeverLoopResult::Otherwise,
+ })
+ .fold(NeverLoopResult::Otherwise, combine_both),
+ ExprKind::Struct(_, _, None)
+ | ExprKind::Yield(_, _)
+ | ExprKind::Closure(_, _, _, _, _)
+ | ExprKind::Path(_)
+ | ExprKind::ConstBlock(_)
+ | ExprKind::Lit(_)
+ | ExprKind::Err => NeverLoopResult::Otherwise,
+ }
+}
+
+fn never_loop_expr_all<'a, T: Iterator<Item = &'a Expr<'a>>>(es: &mut T, main_loop_id: HirId) -> NeverLoopResult {
+ es.map(|e| never_loop_expr(e, main_loop_id))
+ .fold(NeverLoopResult::Otherwise, combine_both)
+}
+
+fn never_loop_expr_branch<'a, T: Iterator<Item = &'a Expr<'a>>>(e: &mut T, main_loop_id: HirId) -> NeverLoopResult {
+ e.map(|e| never_loop_expr(e, main_loop_id))
+ .fold(NeverLoopResult::AlwaysBreak, combine_branches)
+}
+
+fn for_to_if_let_sugg(cx: &LateContext<'_>, iterator: &Expr<'_>, pat: &Pat<'_>) -> String {
+ let pat_snippet = snippet(cx, pat.span, "_");
+ let iter_snippet = make_iterator_snippet(cx, iterator, &mut Applicability::Unspecified);
+
+ format!(
+ "if let Some({pat}) = {iter}.next()",
+ pat = pat_snippet,
+ iter = iter_snippet
+ )
+}
--- /dev/null
- _ => Some(Err(())),
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::source::snippet_opt;
+use clippy_utils::{is_doc_hidden, is_lint_allowed, meets_msrv, msrvs};
+use rustc_ast::ast::{self, VisibilityKind};
+use rustc_data_structures::fx::FxHashSet;
+use rustc_errors::Applicability;
+use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
+use rustc_hir::{self as hir, Expr, ExprKind, QPath};
+use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_middle::ty::DefIdTree;
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::{DefId, LocalDefId};
+use rustc_span::{sym, Span};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for manual implementations of the non-exhaustive pattern.
+ ///
+ /// ### Why is this bad?
+ /// Using the #[non_exhaustive] attribute expresses better the intent
+ /// and allows possible optimizations when applied to enums.
+ ///
+ /// ### Example
+ /// ```rust
+ /// struct S {
+ /// pub a: i32,
+ /// pub b: i32,
+ /// _c: (),
+ /// }
+ ///
+ /// enum E {
+ /// A,
+ /// B,
+ /// #[doc(hidden)]
+ /// _C,
+ /// }
+ ///
+ /// struct T(pub i32, pub i32, ());
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// #[non_exhaustive]
+ /// struct S {
+ /// pub a: i32,
+ /// pub b: i32,
+ /// }
+ ///
+ /// #[non_exhaustive]
+ /// enum E {
+ /// A,
+ /// B,
+ /// }
+ ///
+ /// #[non_exhaustive]
+ /// struct T(pub i32, pub i32);
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub MANUAL_NON_EXHAUSTIVE,
+ style,
+ "manual implementations of the non-exhaustive pattern can be simplified using #[non_exhaustive]"
+}
+
+#[expect(clippy::module_name_repetitions)]
+pub struct ManualNonExhaustiveStruct {
+ msrv: Option<RustcVersion>,
+}
+
+impl ManualNonExhaustiveStruct {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self { msrv }
+ }
+}
+
+impl_lint_pass!(ManualNonExhaustiveStruct => [MANUAL_NON_EXHAUSTIVE]);
+
+#[expect(clippy::module_name_repetitions)]
+pub struct ManualNonExhaustiveEnum {
+ msrv: Option<RustcVersion>,
+ constructed_enum_variants: FxHashSet<(DefId, DefId)>,
+ potential_enums: Vec<(LocalDefId, LocalDefId, Span, Span)>,
+}
+
+impl ManualNonExhaustiveEnum {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self {
+ msrv,
+ constructed_enum_variants: FxHashSet::default(),
+ potential_enums: Vec::new(),
+ }
+ }
+}
+
+impl_lint_pass!(ManualNonExhaustiveEnum => [MANUAL_NON_EXHAUSTIVE]);
+
+impl EarlyLintPass for ManualNonExhaustiveStruct {
+ fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) {
+ if !meets_msrv(self.msrv, msrvs::NON_EXHAUSTIVE) {
+ return;
+ }
+
+ if let ast::ItemKind::Struct(variant_data, _) = &item.kind {
+ let (fields, delimiter) = match variant_data {
+ ast::VariantData::Struct(fields, _) => (&**fields, '{'),
+ ast::VariantData::Tuple(fields, _) => (&**fields, '('),
+ ast::VariantData::Unit(_) => return,
+ };
+ if fields.len() <= 1 {
+ return;
+ }
+ let mut iter = fields.iter().filter_map(|f| match f.vis.kind {
+ VisibilityKind::Public => None,
+ VisibilityKind::Inherited => Some(Ok(f)),
++ VisibilityKind::Restricted { .. } => Some(Err(())),
+ });
+ if let Some(Ok(field)) = iter.next()
+ && iter.next().is_none()
+ && field.ty.kind.is_unit()
+ && field.ident.map_or(true, |name| name.as_str().starts_with('_'))
+ {
+ span_lint_and_then(
+ cx,
+ MANUAL_NON_EXHAUSTIVE,
+ item.span,
+ "this seems like a manual implementation of the non-exhaustive pattern",
+ |diag| {
+ if !item.attrs.iter().any(|attr| attr.has_name(sym::non_exhaustive))
+ && let header_span = cx.sess().source_map().span_until_char(item.span, delimiter)
+ && let Some(snippet) = snippet_opt(cx, header_span)
+ {
+ diag.span_suggestion(
+ header_span,
+ "add the attribute",
+ format!("#[non_exhaustive] {}", snippet),
+ Applicability::Unspecified,
+ );
+ }
+ diag.span_help(field.span, "remove this field");
+ }
+ );
+ }
+ }
+ }
+
+ extract_msrv_attr!(EarlyContext);
+}
+
+impl<'tcx> LateLintPass<'tcx> for ManualNonExhaustiveEnum {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
+ if !meets_msrv(self.msrv, msrvs::NON_EXHAUSTIVE) {
+ return;
+ }
+
+ if let hir::ItemKind::Enum(def, _) = &item.kind
+ && def.variants.len() > 1
+ {
+ let mut iter = def.variants.iter().filter_map(|v| {
+ let id = cx.tcx.hir().local_def_id(v.id);
+ (matches!(v.data, hir::VariantData::Unit(_))
+ && v.ident.as_str().starts_with('_')
+ && is_doc_hidden(cx.tcx.hir().attrs(v.id)))
+ .then(|| (id, v.span))
+ });
+ if let Some((id, span)) = iter.next()
+ && iter.next().is_none()
+ {
+ self.potential_enums.push((item.def_id, id, item.span, span));
+ }
+ }
+ }
+
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ if let ExprKind::Path(QPath::Resolved(None, p)) = &e.kind
+ && let [.., name] = p.segments
+ && let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Const), id) = p.res
+ && name.ident.as_str().starts_with('_')
+ {
+ let variant_id = cx.tcx.parent(id);
+ let enum_id = cx.tcx.parent(variant_id);
+
+ self.constructed_enum_variants.insert((enum_id, variant_id));
+ }
+ }
+
+ fn check_crate_post(&mut self, cx: &LateContext<'tcx>) {
+ for &(enum_id, _, enum_span, variant_span) in
+ self.potential_enums.iter().filter(|&&(enum_id, variant_id, _, _)| {
+ !self
+ .constructed_enum_variants
+ .contains(&(enum_id.to_def_id(), variant_id.to_def_id()))
+ && !is_lint_allowed(cx, MANUAL_NON_EXHAUSTIVE, cx.tcx.hir().local_def_id_to_hir_id(enum_id))
+ })
+ {
+ span_lint_and_then(
+ cx,
+ MANUAL_NON_EXHAUSTIVE,
+ enum_span,
+ "this seems like a manual implementation of the non-exhaustive pattern",
+ |diag| {
+ if !cx.tcx.adt_def(enum_id).is_variant_list_non_exhaustive()
+ && let header_span = cx.sess().source_map().span_until_char(enum_span, '{')
+ && let Some(snippet) = snippet_opt(cx, header_span)
+ {
+ diag.span_suggestion(
+ header_span,
+ "add the attribute",
+ format!("#[non_exhaustive] {}", snippet),
+ Applicability::Unspecified,
+ );
+ }
+ diag.span_help(variant_span, "remove this variant");
+ },
+ );
+ }
+ }
+
+ extract_msrv_attr!(LateContext);
+}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint_and_then;
++use clippy_utils::higher::IfLetOrMatch;
++use clippy_utils::visitors::is_local_used;
++use clippy_utils::{is_lang_ctor, is_unit_expr, path_to_local, peel_blocks_with_stmt, peel_ref_operators, SpanlessEq};
++use if_chain::if_chain;
++use rustc_errors::MultiSpan;
++use rustc_hir::LangItem::OptionNone;
++use rustc_hir::{Arm, Expr, Guard, HirId, Let, Pat, PatKind};
++use rustc_lint::LateContext;
++use rustc_span::Span;
++
++use super::COLLAPSIBLE_MATCH;
++
++pub(super) fn check_match<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>]) {
++ if let Some(els_arm) = arms.iter().rfind(|arm| arm_is_wild_like(cx, arm)) {
++ for arm in arms {
++ check_arm(cx, true, arm.pat, arm.body, arm.guard.as_ref(), Some(els_arm.body));
++ }
++ }
++}
++
++pub(super) fn check_if_let<'tcx>(
++ cx: &LateContext<'tcx>,
++ pat: &'tcx Pat<'_>,
++ body: &'tcx Expr<'_>,
++ else_expr: Option<&'tcx Expr<'_>>,
++) {
++ check_arm(cx, false, pat, body, None, else_expr);
++}
++
++fn check_arm<'tcx>(
++ cx: &LateContext<'tcx>,
++ outer_is_match: bool,
++ outer_pat: &'tcx Pat<'tcx>,
++ outer_then_body: &'tcx Expr<'tcx>,
++ outer_guard: Option<&'tcx Guard<'tcx>>,
++ outer_else_body: Option<&'tcx Expr<'tcx>>,
++) {
++ let inner_expr = peel_blocks_with_stmt(outer_then_body);
++ if_chain! {
++ if let Some(inner) = IfLetOrMatch::parse(cx, inner_expr);
++ if let Some((inner_scrutinee, inner_then_pat, inner_else_body)) = match inner {
++ IfLetOrMatch::IfLet(scrutinee, pat, _, els) => Some((scrutinee, pat, els)),
++ IfLetOrMatch::Match(scrutinee, arms, ..) => if_chain! {
++ // if there are more than two arms, collapsing would be non-trivial
++ if arms.len() == 2 && arms.iter().all(|a| a.guard.is_none());
++ // one of the arms must be "wild-like"
++ if let Some(wild_idx) = arms.iter().rposition(|a| arm_is_wild_like(cx, a));
++ then {
++ let (then, els) = (&arms[1 - wild_idx], &arms[wild_idx]);
++ Some((scrutinee, then.pat, Some(els.body)))
++ } else {
++ None
++ }
++ },
++ };
++ if outer_pat.span.ctxt() == inner_scrutinee.span.ctxt();
++ // match expression must be a local binding
++ // match <local> { .. }
++ if let Some(binding_id) = path_to_local(peel_ref_operators(cx, inner_scrutinee));
++ if !pat_contains_or(inner_then_pat);
++ // the binding must come from the pattern of the containing match arm
++ // ..<local>.. => match <local> { .. }
++ if let Some(binding_span) = find_pat_binding(outer_pat, binding_id);
++ // the "else" branches must be equal
++ if match (outer_else_body, inner_else_body) {
++ (None, None) => true,
++ (None, Some(e)) | (Some(e), None) => is_unit_expr(e),
++ (Some(a), Some(b)) => SpanlessEq::new(cx).eq_expr(a, b),
++ };
++ // the binding must not be used in the if guard
++ if outer_guard.map_or(
++ true,
++ |(Guard::If(e) | Guard::IfLet(Let { init: e, .. }))| !is_local_used(cx, *e, binding_id)
++ );
++ // ...or anywhere in the inner expression
++ if match inner {
++ IfLetOrMatch::IfLet(_, _, body, els) => {
++ !is_local_used(cx, body, binding_id) && els.map_or(true, |e| !is_local_used(cx, e, binding_id))
++ },
++ IfLetOrMatch::Match(_, arms, ..) => !arms.iter().any(|arm| is_local_used(cx, arm, binding_id)),
++ };
++ then {
++ let msg = format!(
++ "this `{}` can be collapsed into the outer `{}`",
++ if matches!(inner, IfLetOrMatch::Match(..)) { "match" } else { "if let" },
++ if outer_is_match { "match" } else { "if let" },
++ );
++ span_lint_and_then(
++ cx,
++ COLLAPSIBLE_MATCH,
++ inner_expr.span,
++ &msg,
++ |diag| {
++ let mut help_span = MultiSpan::from_spans(vec![binding_span, inner_then_pat.span]);
++ help_span.push_span_label(binding_span, "replace this binding");
++ help_span.push_span_label(inner_then_pat.span, "with this pattern");
++ diag.span_help(help_span, "the outer pattern can be modified to include the inner pattern");
++ },
++ );
++ }
++ }
++}
++
++/// A "wild-like" arm has a wild (`_`) or `None` pattern and no guard. Such arms can be "collapsed"
++/// into a single wild arm without any significant loss in semantics or readability.
++fn arm_is_wild_like(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool {
++ if arm.guard.is_some() {
++ return false;
++ }
++ match arm.pat.kind {
++ PatKind::Binding(..) | PatKind::Wild => true,
++ PatKind::Path(ref qpath) => is_lang_ctor(cx, qpath, OptionNone),
++ _ => false,
++ }
++}
++
++fn find_pat_binding(pat: &Pat<'_>, hir_id: HirId) -> Option<Span> {
++ let mut span = None;
++ pat.walk_short(|p| match &p.kind {
++ // ignore OR patterns
++ PatKind::Or(_) => false,
++ PatKind::Binding(_bm, _, _ident, _) => {
++ let found = p.hir_id == hir_id;
++ if found {
++ span = Some(p.span);
++ }
++ !found
++ },
++ _ => true,
++ });
++ span
++}
++
++fn pat_contains_or(pat: &Pat<'_>) -> bool {
++ let mut result = false;
++ pat.walk(|p| {
++ let is_or = matches!(p.kind, PatKind::Or(_));
++ result |= is_or;
++ !is_or
++ });
++ result
++}
--- /dev/null
--- /dev/null
++use crate::{map_unit_fn::OPTION_MAP_UNIT_FN, matches::MATCH_AS_REF};
++use clippy_utils::diagnostics::span_lint_and_sugg;
++use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
++use clippy_utils::ty::{is_type_diagnostic_item, peel_mid_ty_refs_is_mutable, type_is_unsafe_function};
++use clippy_utils::{
++ can_move_expr_to_closure, is_else_clause, is_lang_ctor, is_lint_allowed, path_to_local_id, peel_blocks,
++ peel_hir_expr_refs, peel_hir_expr_while, CaptureKind,
++};
++use rustc_ast::util::parser::PREC_POSTFIX;
++use rustc_errors::Applicability;
++use rustc_hir::LangItem::{OptionNone, OptionSome};
++use rustc_hir::{
++ def::Res, Arm, BindingAnnotation, Block, BlockCheckMode, Expr, ExprKind, HirId, Mutability, Pat, PatKind, Path,
++ QPath, UnsafeSource,
++};
++use rustc_lint::LateContext;
++use rustc_span::{sym, SyntaxContext};
++
++use super::MANUAL_MAP;
++
++pub(super) fn check_match<'tcx>(
++ cx: &LateContext<'tcx>,
++ expr: &'tcx Expr<'_>,
++ scrutinee: &'tcx Expr<'_>,
++ arms: &'tcx [Arm<'_>],
++) {
++ if let [arm1, arm2] = arms
++ && arm1.guard.is_none()
++ && arm2.guard.is_none()
++ {
++ check(cx, expr, scrutinee, arm1.pat, arm1.body, Some(arm2.pat), arm2.body);
++ }
++}
++
++pub(super) fn check_if_let<'tcx>(
++ cx: &LateContext<'tcx>,
++ expr: &'tcx Expr<'_>,
++ let_pat: &'tcx Pat<'_>,
++ let_expr: &'tcx Expr<'_>,
++ then_expr: &'tcx Expr<'_>,
++ else_expr: &'tcx Expr<'_>,
++) {
++ check(cx, expr, let_expr, let_pat, then_expr, None, else_expr);
++}
++
++#[expect(clippy::too_many_lines)]
++fn check<'tcx>(
++ cx: &LateContext<'tcx>,
++ expr: &'tcx Expr<'_>,
++ scrutinee: &'tcx Expr<'_>,
++ then_pat: &'tcx Pat<'_>,
++ then_body: &'tcx Expr<'_>,
++ else_pat: Option<&'tcx Pat<'_>>,
++ else_body: &'tcx Expr<'_>,
++) {
++ let (scrutinee_ty, ty_ref_count, ty_mutability) =
++ peel_mid_ty_refs_is_mutable(cx.typeck_results().expr_ty(scrutinee));
++ if !(is_type_diagnostic_item(cx, scrutinee_ty, sym::Option)
++ && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::Option))
++ {
++ return;
++ }
++
++ let expr_ctxt = expr.span.ctxt();
++ let (some_expr, some_pat, pat_ref_count, is_wild_none) = match (
++ try_parse_pattern(cx, then_pat, expr_ctxt),
++ else_pat.map_or(Some(OptionPat::Wild), |p| try_parse_pattern(cx, p, expr_ctxt)),
++ ) {
++ (Some(OptionPat::Wild), Some(OptionPat::Some { pattern, ref_count })) if is_none_expr(cx, then_body) => {
++ (else_body, pattern, ref_count, true)
++ },
++ (Some(OptionPat::None), Some(OptionPat::Some { pattern, ref_count })) if is_none_expr(cx, then_body) => {
++ (else_body, pattern, ref_count, false)
++ },
++ (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::Wild)) if is_none_expr(cx, else_body) => {
++ (then_body, pattern, ref_count, true)
++ },
++ (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::None)) if is_none_expr(cx, else_body) => {
++ (then_body, pattern, ref_count, false)
++ },
++ _ => return,
++ };
++
++ // Top level or patterns aren't allowed in closures.
++ if matches!(some_pat.kind, PatKind::Or(_)) {
++ return;
++ }
++
++ let some_expr = match get_some_expr(cx, some_expr, false, expr_ctxt) {
++ Some(expr) => expr,
++ None => return,
++ };
++
++ // These two lints will go back and forth with each other.
++ if cx.typeck_results().expr_ty(some_expr.expr) == cx.tcx.types.unit
++ && !is_lint_allowed(cx, OPTION_MAP_UNIT_FN, expr.hir_id)
++ {
++ return;
++ }
++
++ // `map` won't perform any adjustments.
++ if !cx.typeck_results().expr_adjustments(some_expr.expr).is_empty() {
++ return;
++ }
++
++ // Determine which binding mode to use.
++ let explicit_ref = some_pat.contains_explicit_ref_binding();
++ let binding_ref = explicit_ref.or_else(|| (ty_ref_count != pat_ref_count).then(|| ty_mutability));
++
++ let as_ref_str = match binding_ref {
++ Some(Mutability::Mut) => ".as_mut()",
++ Some(Mutability::Not) => ".as_ref()",
++ None => "",
++ };
++
++ match can_move_expr_to_closure(cx, some_expr.expr) {
++ Some(captures) => {
++ // Check if captures the closure will need conflict with borrows made in the scrutinee.
++ // TODO: check all the references made in the scrutinee expression. This will require interacting
++ // with the borrow checker. Currently only `<local>[.<field>]*` is checked for.
++ if let Some(binding_ref_mutability) = binding_ref {
++ let e = peel_hir_expr_while(scrutinee, |e| match e.kind {
++ ExprKind::Field(e, _) | ExprKind::AddrOf(_, _, e) => Some(e),
++ _ => None,
++ });
++ if let ExprKind::Path(QPath::Resolved(None, Path { res: Res::Local(l), .. })) = e.kind {
++ match captures.get(l) {
++ Some(CaptureKind::Value | CaptureKind::Ref(Mutability::Mut)) => return,
++ Some(CaptureKind::Ref(Mutability::Not)) if binding_ref_mutability == Mutability::Mut => {
++ return;
++ },
++ Some(CaptureKind::Ref(Mutability::Not)) | None => (),
++ }
++ }
++ }
++ },
++ None => return,
++ };
++
++ let mut app = Applicability::MachineApplicable;
++
++ // Remove address-of expressions from the scrutinee. Either `as_ref` will be called, or
++ // it's being passed by value.
++ let scrutinee = peel_hir_expr_refs(scrutinee).0;
++ let (scrutinee_str, _) = snippet_with_context(cx, scrutinee.span, expr_ctxt, "..", &mut app);
++ let scrutinee_str = if scrutinee.span.ctxt() == expr.span.ctxt() && scrutinee.precedence().order() < PREC_POSTFIX {
++ format!("({})", scrutinee_str)
++ } else {
++ scrutinee_str.into()
++ };
++
++ let body_str = if let PatKind::Binding(annotation, id, some_binding, None) = some_pat.kind {
++ if_chain! {
++ if !some_expr.needs_unsafe_block;
++ if let Some(func) = can_pass_as_func(cx, id, some_expr.expr);
++ if func.span.ctxt() == some_expr.expr.span.ctxt();
++ then {
++ snippet_with_applicability(cx, func.span, "..", &mut app).into_owned()
++ } else {
++ if path_to_local_id(some_expr.expr, id)
++ && !is_lint_allowed(cx, MATCH_AS_REF, expr.hir_id)
++ && binding_ref.is_some()
++ {
++ return;
++ }
++
++ // `ref` and `ref mut` annotations were handled earlier.
++ let annotation = if matches!(annotation, BindingAnnotation::Mutable) {
++ "mut "
++ } else {
++ ""
++ };
++ let expr_snip = snippet_with_context(cx, some_expr.expr.span, expr_ctxt, "..", &mut app).0;
++ if some_expr.needs_unsafe_block {
++ format!("|{}{}| unsafe {{ {} }}", annotation, some_binding, expr_snip)
++ } else {
++ format!("|{}{}| {}", annotation, some_binding, expr_snip)
++ }
++ }
++ }
++ } else if !is_wild_none && explicit_ref.is_none() {
++ // TODO: handle explicit reference annotations.
++ let pat_snip = snippet_with_context(cx, some_pat.span, expr_ctxt, "..", &mut app).0;
++ let expr_snip = snippet_with_context(cx, some_expr.expr.span, expr_ctxt, "..", &mut app).0;
++ if some_expr.needs_unsafe_block {
++ format!("|{}| unsafe {{ {} }}", pat_snip, expr_snip)
++ } else {
++ format!("|{}| {}", pat_snip, expr_snip)
++ }
++ } else {
++ // Refutable bindings and mixed reference annotations can't be handled by `map`.
++ return;
++ };
++
++ span_lint_and_sugg(
++ cx,
++ MANUAL_MAP,
++ expr.span,
++ "manual implementation of `Option::map`",
++ "try this",
++ if else_pat.is_none() && is_else_clause(cx.tcx, expr) {
++ format!("{{ {}{}.map({}) }}", scrutinee_str, as_ref_str, body_str)
++ } else {
++ format!("{}{}.map({})", scrutinee_str, as_ref_str, body_str)
++ },
++ app,
++ );
++}
++
++// Checks whether the expression could be passed as a function, or whether a closure is needed.
++// Returns the function to be passed to `map` if it exists.
++fn can_pass_as_func<'tcx>(cx: &LateContext<'tcx>, binding: HirId, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
++ match expr.kind {
++ ExprKind::Call(func, [arg])
++ if path_to_local_id(arg, binding)
++ && cx.typeck_results().expr_adjustments(arg).is_empty()
++ && !type_is_unsafe_function(cx, cx.typeck_results().expr_ty(func).peel_refs()) =>
++ {
++ Some(func)
++ },
++ _ => None,
++ }
++}
++
++enum OptionPat<'a> {
++ Wild,
++ None,
++ Some {
++ // The pattern contained in the `Some` tuple.
++ pattern: &'a Pat<'a>,
++ // The number of references before the `Some` tuple.
++ // e.g. `&&Some(_)` has a ref count of 2.
++ ref_count: usize,
++ },
++}
++
++struct SomeExpr<'tcx> {
++ expr: &'tcx Expr<'tcx>,
++ needs_unsafe_block: bool,
++}
++
++// Try to parse into a recognized `Option` pattern.
++// i.e. `_`, `None`, `Some(..)`, or a reference to any of those.
++fn try_parse_pattern<'tcx>(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, ctxt: SyntaxContext) -> Option<OptionPat<'tcx>> {
++ fn f<'tcx>(
++ cx: &LateContext<'tcx>,
++ pat: &'tcx Pat<'_>,
++ ref_count: usize,
++ ctxt: SyntaxContext,
++ ) -> Option<OptionPat<'tcx>> {
++ match pat.kind {
++ PatKind::Wild => Some(OptionPat::Wild),
++ PatKind::Ref(pat, _) => f(cx, pat, ref_count + 1, ctxt),
++ PatKind::Path(ref qpath) if is_lang_ctor(cx, qpath, OptionNone) => Some(OptionPat::None),
++ PatKind::TupleStruct(ref qpath, [pattern], _)
++ if is_lang_ctor(cx, qpath, OptionSome) && pat.span.ctxt() == ctxt =>
++ {
++ Some(OptionPat::Some { pattern, ref_count })
++ },
++ _ => None,
++ }
++ }
++ f(cx, pat, 0, ctxt)
++}
++
++// Checks for an expression wrapped by the `Some` constructor. Returns the contained expression.
++fn get_some_expr<'tcx>(
++ cx: &LateContext<'tcx>,
++ expr: &'tcx Expr<'_>,
++ needs_unsafe_block: bool,
++ ctxt: SyntaxContext,
++) -> Option<SomeExpr<'tcx>> {
++ // TODO: Allow more complex expressions.
++ match expr.kind {
++ ExprKind::Call(
++ Expr {
++ kind: ExprKind::Path(ref qpath),
++ ..
++ },
++ [arg],
++ ) if ctxt == expr.span.ctxt() && is_lang_ctor(cx, qpath, OptionSome) => Some(SomeExpr {
++ expr: arg,
++ needs_unsafe_block,
++ }),
++ ExprKind::Block(
++ Block {
++ stmts: [],
++ expr: Some(expr),
++ rules,
++ ..
++ },
++ _,
++ ) => get_some_expr(
++ cx,
++ expr,
++ needs_unsafe_block || *rules == BlockCheckMode::UnsafeBlock(UnsafeSource::UserProvided),
++ ctxt,
++ ),
++ _ => None,
++ }
++}
++
++// Checks for the `None` value.
++fn is_none_expr(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
++ matches!(peel_blocks(expr).kind, ExprKind::Path(ref qpath) if is_lang_ctor(cx, qpath, OptionNone))
++}
--- /dev/null
--- /dev/null
++use clippy_utils::consts::constant_simple;
++use clippy_utils::diagnostics::span_lint_and_sugg;
++use clippy_utils::source::{indent_of, reindent_multiline, snippet_opt};
++use clippy_utils::ty::is_type_diagnostic_item;
++use clippy_utils::usage::contains_return_break_continue_macro;
++use clippy_utils::{is_lang_ctor, path_to_local_id, sugg};
++use if_chain::if_chain;
++use rustc_errors::Applicability;
++use rustc_hir::LangItem::{OptionNone, OptionSome, ResultErr, ResultOk};
++use rustc_hir::{Arm, Expr, PatKind};
++use rustc_lint::LateContext;
++use rustc_span::sym;
++
++use super::MANUAL_UNWRAP_OR;
++
++pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>, scrutinee: &'tcx Expr<'_>, arms: &'tcx [Arm<'_>]) {
++ let ty = cx.typeck_results().expr_ty(scrutinee);
++ if_chain! {
++ if let Some(ty_name) = if is_type_diagnostic_item(cx, ty, sym::Option) {
++ Some("Option")
++ } else if is_type_diagnostic_item(cx, ty, sym::Result) {
++ Some("Result")
++ } else {
++ None
++ };
++ if let Some(or_arm) = applicable_or_arm(cx, arms);
++ if let Some(or_body_snippet) = snippet_opt(cx, or_arm.body.span);
++ if let Some(indent) = indent_of(cx, expr.span);
++ if constant_simple(cx, cx.typeck_results(), or_arm.body).is_some();
++ then {
++ let reindented_or_body =
++ reindent_multiline(or_body_snippet.into(), true, Some(indent));
++
++ let suggestion = if scrutinee.span.from_expansion() {
++ // we don't want parentheses around macro, e.g. `(some_macro!()).unwrap_or(0)`
++ sugg::Sugg::hir_with_macro_callsite(cx, scrutinee, "..")
++ }
++ else {
++ sugg::Sugg::hir(cx, scrutinee, "..").maybe_par()
++ };
++
++ span_lint_and_sugg(
++ cx,
++ MANUAL_UNWRAP_OR, expr.span,
++ &format!("this pattern reimplements `{}::unwrap_or`", ty_name),
++ "replace with",
++ format!(
++ "{}.unwrap_or({})",
++ suggestion,
++ reindented_or_body,
++ ),
++ Applicability::MachineApplicable,
++ );
++ }
++ }
++}
++
++fn applicable_or_arm<'a>(cx: &LateContext<'_>, arms: &'a [Arm<'a>]) -> Option<&'a Arm<'a>> {
++ if_chain! {
++ if arms.len() == 2;
++ if arms.iter().all(|arm| arm.guard.is_none());
++ if let Some((idx, or_arm)) = arms.iter().enumerate().find(|(_, arm)| {
++ match arm.pat.kind {
++ PatKind::Path(ref qpath) => is_lang_ctor(cx, qpath, OptionNone),
++ PatKind::TupleStruct(ref qpath, [pat], _) =>
++ matches!(pat.kind, PatKind::Wild) && is_lang_ctor(cx, qpath, ResultErr),
++ _ => false,
++ }
++ });
++ let unwrap_arm = &arms[1 - idx];
++ if let PatKind::TupleStruct(ref qpath, [unwrap_pat], _) = unwrap_arm.pat.kind;
++ if is_lang_ctor(cx, qpath, OptionSome) || is_lang_ctor(cx, qpath, ResultOk);
++ if let PatKind::Binding(_, binding_hir_id, ..) = unwrap_pat.kind;
++ if path_to_local_id(unwrap_arm.body, binding_hir_id);
++ if cx.typeck_results().expr_adjustments(unwrap_arm.body).is_empty();
++ if !contains_return_break_continue_macro(or_arm.body);
++ then {
++ Some(or_arm)
++ } else {
++ None
++ }
++ }
++}
--- /dev/null
- LitKind::Bool(true) => Some((&*arms[0].body, &*arms[1].body)),
- LitKind::Bool(false) => Some((&*arms[1].body, &*arms[0].body)),
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::is_unit_expr;
+use clippy_utils::source::{expr_block, snippet};
+use clippy_utils::sugg::Sugg;
+use rustc_ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{Arm, Expr, ExprKind, PatKind};
+use rustc_lint::LateContext;
+use rustc_middle::ty;
+
+use super::MATCH_BOOL;
+
+pub(crate) fn check(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: &Expr<'_>) {
+ // Type of expression is `bool`.
+ if *cx.typeck_results().expr_ty(ex).kind() == ty::Bool {
+ span_lint_and_then(
+ cx,
+ MATCH_BOOL,
+ expr.span,
+ "you seem to be trying to match on a boolean expression",
+ move |diag| {
+ if arms.len() == 2 {
+ // no guards
+ let exprs = if let PatKind::Lit(arm_bool) = arms[0].pat.kind {
+ if let ExprKind::Lit(ref lit) = arm_bool.kind {
+ match lit.node {
++ LitKind::Bool(true) => Some((arms[0].body, arms[1].body)),
++ LitKind::Bool(false) => Some((arms[1].body, arms[0].body)),
+ _ => None,
+ }
+ } else {
+ None
+ }
+ } else {
+ None
+ };
+
+ if let Some((true_expr, false_expr)) = exprs {
+ let sugg = match (is_unit_expr(true_expr), is_unit_expr(false_expr)) {
+ (false, false) => Some(format!(
+ "if {} {} else {}",
+ snippet(cx, ex.span, "b"),
+ expr_block(cx, true_expr, None, "..", Some(expr.span)),
+ expr_block(cx, false_expr, None, "..", Some(expr.span))
+ )),
+ (false, true) => Some(format!(
+ "if {} {}",
+ snippet(cx, ex.span, "b"),
+ expr_block(cx, true_expr, None, "..", Some(expr.span))
+ )),
+ (true, false) => {
+ let test = Sugg::hir(cx, ex, "..");
+ Some(format!(
+ "if {} {}",
+ !test,
+ expr_block(cx, false_expr, None, "..", Some(expr.span))
+ ))
+ },
+ (true, true) => None,
+ };
+
+ if let Some(sugg) = sugg {
+ diag.span_suggestion(
+ expr.span,
+ "consider using an `if`/`else` expression",
+ sugg,
+ Applicability::HasPlaceholders,
+ );
+ }
+ }
+ }
+ },
+ );
+ }
+}
--- /dev/null
- use clippy_utils::{higher, is_wild};
+use clippy_utils::diagnostics::span_lint_and_sugg;
++use clippy_utils::is_wild;
+use clippy_utils::source::snippet_with_applicability;
- pub(crate) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
- if let Some(higher::IfLet {
- let_pat,
+use rustc_ast::{Attribute, LitKind};
+use rustc_errors::Applicability;
+use rustc_hir::{Arm, BorrowKind, Expr, ExprKind, Guard, Pat};
+use rustc_lint::LateContext;
+use rustc_middle::ty;
+use rustc_span::source_map::Spanned;
+
+use super::MATCH_LIKE_MATCHES_MACRO;
+
+/// Lint a `match` or `if let .. { .. } else { .. }` expr that could be replaced by `matches!`
- if_then,
- if_else: Some(if_else),
- }) = higher::IfLet::hir(cx, expr)
- {
- find_matches_sugg(
- cx,
- let_expr,
- IntoIterator::into_iter([(&[][..], Some(let_pat), if_then, None), (&[][..], None, if_else, None)]),
- expr,
- true,
- );
- }
++pub(crate) fn check_if_let<'tcx>(
++ cx: &LateContext<'tcx>,
++ expr: &'tcx Expr<'_>,
++ let_pat: &'tcx Pat<'_>,
++ let_expr: &'tcx Expr<'_>,
++ then_expr: &'tcx Expr<'_>,
++ else_expr: &'tcx Expr<'_>,
++) {
++ find_matches_sugg(
++ cx,
+ let_expr,
++ IntoIterator::into_iter([
++ (&[][..], Some(let_pat), then_expr, None),
++ (&[][..], None, else_expr, None),
++ ]),
++ expr,
++ true,
++ );
+}
+
+pub(super) fn check_match<'tcx>(
+ cx: &LateContext<'tcx>,
+ e: &'tcx Expr<'_>,
+ scrutinee: &'tcx Expr<'_>,
+ arms: &'tcx [Arm<'tcx>],
+) -> bool {
+ find_matches_sugg(
+ cx,
+ scrutinee,
+ arms.iter().map(|arm| {
+ (
+ cx.tcx.hir().attrs(arm.hir_id),
+ Some(arm.pat),
+ arm.body,
+ arm.guard.as_ref(),
+ )
+ }),
+ e,
+ false,
+ )
+}
+
+/// Lint a `match` or `if let` for replacement by `matches!`
+fn find_matches_sugg<'a, 'b, I>(
+ cx: &LateContext<'_>,
+ ex: &Expr<'_>,
+ mut iter: I,
+ expr: &Expr<'_>,
+ is_if_let: bool,
+) -> bool
+where
+ 'b: 'a,
+ I: Clone
+ + DoubleEndedIterator
+ + ExactSizeIterator
+ + Iterator<
+ Item = (
+ &'a [Attribute],
+ Option<&'a Pat<'b>>,
+ &'a Expr<'b>,
+ Option<&'a Guard<'b>>,
+ ),
+ >,
+{
+ if_chain! {
+ if iter.len() >= 2;
+ if cx.typeck_results().expr_ty(expr).is_bool();
+ if let Some((_, last_pat_opt, last_expr, _)) = iter.next_back();
+ let iter_without_last = iter.clone();
+ if let Some((first_attrs, _, first_expr, first_guard)) = iter.next();
+ if let Some(b0) = find_bool_lit(&first_expr.kind, is_if_let);
+ if let Some(b1) = find_bool_lit(&last_expr.kind, is_if_let);
+ if b0 != b1;
+ if first_guard.is_none() || iter.len() == 0;
+ if first_attrs.is_empty();
+ if iter
+ .all(|arm| {
+ find_bool_lit(&arm.2.kind, is_if_let).map_or(false, |b| b == b0) && arm.3.is_none() && arm.0.is_empty()
+ });
+ then {
+ if let Some(last_pat) = last_pat_opt {
+ if !is_wild(last_pat) {
+ return false;
+ }
+ }
+
+ // The suggestion may be incorrect, because some arms can have `cfg` attributes
+ // evaluated into `false` and so such arms will be stripped before.
+ let mut applicability = Applicability::MaybeIncorrect;
+ let pat = {
+ use itertools::Itertools as _;
+ iter_without_last
+ .filter_map(|arm| {
+ let pat_span = arm.1?.span;
+ Some(snippet_with_applicability(cx, pat_span, "..", &mut applicability))
+ })
+ .join(" | ")
+ };
+ let pat_and_guard = if let Some(Guard::If(g)) = first_guard {
+ format!("{} if {}", pat, snippet_with_applicability(cx, g.span, "..", &mut applicability))
+ } else {
+ pat
+ };
+
+ // strip potential borrows (#6503), but only if the type is a reference
+ let mut ex_new = ex;
+ if let ExprKind::AddrOf(BorrowKind::Ref, .., ex_inner) = ex.kind {
+ if let ty::Ref(..) = cx.typeck_results().expr_ty(ex_inner).kind() {
+ ex_new = ex_inner;
+ }
+ };
+ span_lint_and_sugg(
+ cx,
+ MATCH_LIKE_MATCHES_MACRO,
+ expr.span,
+ &format!("{} expression looks like `matches!` macro", if is_if_let { "if let .. else" } else { "match" }),
+ "try this",
+ format!(
+ "{}matches!({}, {})",
+ if b0 { "" } else { "!" },
+ snippet_with_applicability(cx, ex_new.span, "..", &mut applicability),
+ pat_and_guard,
+ ),
+ applicability,
+ );
+ true
+ } else {
+ false
+ }
+ }
+}
+
+/// Extract a `bool` or `{ bool }`
+fn find_bool_lit(ex: &ExprKind<'_>, is_if_let: bool) -> Option<bool> {
+ match ex {
+ ExprKind::Lit(Spanned {
+ node: LitKind::Bool(b), ..
+ }) => Some(*b),
+ ExprKind::Block(
+ rustc_hir::Block {
+ stmts: &[],
+ expr: Some(exp),
+ ..
+ },
+ _,
+ ) if is_if_let => {
+ if let ExprKind::Lit(Spanned {
+ node: LitKind::Bool(b), ..
+ }) = exp.kind
+ {
+ Some(b)
+ } else {
+ None
+ }
+ },
+ _ => None,
+ }
+}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint_and_sugg;
++use clippy_utils::source::snippet;
++use clippy_utils::ty::{is_type_diagnostic_item, is_type_lang_item};
++use if_chain::if_chain;
++use rustc_errors::Applicability;
++use rustc_hir::{Expr, ExprKind, LangItem};
++use rustc_lint::LateContext;
++use rustc_span::sym;
++
++use super::MATCH_ON_VEC_ITEMS;
++
++pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, scrutinee: &'tcx Expr<'_>) {
++ if_chain! {
++ if let Some(idx_expr) = is_vec_indexing(cx, scrutinee);
++ if let ExprKind::Index(vec, idx) = idx_expr.kind;
++
++ then {
++ // FIXME: could be improved to suggest surrounding every pattern with Some(_),
++ // but only when `or_patterns` are stabilized.
++ span_lint_and_sugg(
++ cx,
++ MATCH_ON_VEC_ITEMS,
++ scrutinee.span,
++ "indexing into a vector may panic",
++ "try this",
++ format!(
++ "{}.get({})",
++ snippet(cx, vec.span, ".."),
++ snippet(cx, idx.span, "..")
++ ),
++ Applicability::MaybeIncorrect
++ );
++ }
++ }
++}
++
++fn is_vec_indexing<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> {
++ if_chain! {
++ if let ExprKind::Index(array, index) = expr.kind;
++ if is_vector(cx, array);
++ if !is_full_range(cx, index);
++
++ then {
++ return Some(expr);
++ }
++ }
++
++ None
++}
++
++fn is_vector(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
++ let ty = cx.typeck_results().expr_ty(expr);
++ let ty = ty.peel_refs();
++ is_type_diagnostic_item(cx, ty, sym::Vec)
++}
++
++fn is_full_range(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
++ let ty = cx.typeck_results().expr_ty(expr);
++ let ty = ty.peel_refs();
++ is_type_lang_item(cx, ty, LangItem::RangeFull)
++}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint_and_sugg;
++use clippy_utils::ty::is_type_diagnostic_item;
++use rustc_ast::ast::LitKind;
++use rustc_errors::Applicability;
++use rustc_hir::intravisit::{walk_expr, Visitor};
++use rustc_hir::{Arm, Expr, ExprKind, PatKind};
++use rustc_lint::LateContext;
++use rustc_middle::ty;
++use rustc_span::symbol::Symbol;
++use rustc_span::{sym, Span};
++
++use super::MATCH_STR_CASE_MISMATCH;
++
++#[derive(Debug)]
++enum CaseMethod {
++ LowerCase,
++ AsciiLowerCase,
++ UpperCase,
++ AsciiUppercase,
++}
++
++pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, scrutinee: &'tcx Expr<'_>, arms: &'tcx [Arm<'_>]) {
++ if_chain! {
++ if let ty::Ref(_, ty, _) = cx.typeck_results().expr_ty(scrutinee).kind();
++ if let ty::Str = ty.kind();
++ then {
++ let mut visitor = MatchExprVisitor {
++ cx,
++ case_method: None,
++ };
++
++ visitor.visit_expr(scrutinee);
++
++ if let Some(case_method) = visitor.case_method {
++ if let Some((bad_case_span, bad_case_sym)) = verify_case(&case_method, arms) {
++ lint(cx, &case_method, bad_case_span, bad_case_sym.as_str());
++ }
++ }
++ }
++ }
++}
++
++struct MatchExprVisitor<'a, 'tcx> {
++ cx: &'a LateContext<'tcx>,
++ case_method: Option<CaseMethod>,
++}
++
++impl<'a, 'tcx> Visitor<'tcx> for MatchExprVisitor<'a, 'tcx> {
++ fn visit_expr(&mut self, ex: &'tcx Expr<'_>) {
++ match ex.kind {
++ ExprKind::MethodCall(segment, [receiver], _) if self.case_altered(segment.ident.as_str(), receiver) => {},
++ _ => walk_expr(self, ex),
++ }
++ }
++}
++
++impl<'a, 'tcx> MatchExprVisitor<'a, 'tcx> {
++ fn case_altered(&mut self, segment_ident: &str, receiver: &Expr<'_>) -> bool {
++ if let Some(case_method) = get_case_method(segment_ident) {
++ let ty = self.cx.typeck_results().expr_ty(receiver).peel_refs();
++
++ if is_type_diagnostic_item(self.cx, ty, sym::String) || ty.kind() == &ty::Str {
++ self.case_method = Some(case_method);
++ return true;
++ }
++ }
++
++ false
++ }
++}
++
++fn get_case_method(segment_ident_str: &str) -> Option<CaseMethod> {
++ match segment_ident_str {
++ "to_lowercase" => Some(CaseMethod::LowerCase),
++ "to_ascii_lowercase" => Some(CaseMethod::AsciiLowerCase),
++ "to_uppercase" => Some(CaseMethod::UpperCase),
++ "to_ascii_uppercase" => Some(CaseMethod::AsciiUppercase),
++ _ => None,
++ }
++}
++
++fn verify_case<'a>(case_method: &'a CaseMethod, arms: &'a [Arm<'_>]) -> Option<(Span, Symbol)> {
++ let case_check = match case_method {
++ CaseMethod::LowerCase => |input: &str| -> bool { input.chars().all(|c| c.to_lowercase().next() == Some(c)) },
++ CaseMethod::AsciiLowerCase => |input: &str| -> bool { !input.chars().any(|c| c.is_ascii_uppercase()) },
++ CaseMethod::UpperCase => |input: &str| -> bool { input.chars().all(|c| c.to_uppercase().next() == Some(c)) },
++ CaseMethod::AsciiUppercase => |input: &str| -> bool { !input.chars().any(|c| c.is_ascii_lowercase()) },
++ };
++
++ for arm in arms {
++ if_chain! {
++ if let PatKind::Lit(Expr {
++ kind: ExprKind::Lit(lit),
++ ..
++ }) = arm.pat.kind;
++ if let LitKind::Str(symbol, _) = lit.node;
++ let input = symbol.as_str();
++ if !case_check(input);
++ then {
++ return Some((lit.span, symbol));
++ }
++ }
++ }
++
++ None
++}
++
++fn lint(cx: &LateContext<'_>, case_method: &CaseMethod, bad_case_span: Span, bad_case_str: &str) {
++ let (method_str, suggestion) = match case_method {
++ CaseMethod::LowerCase => ("to_lowercase", bad_case_str.to_lowercase()),
++ CaseMethod::AsciiLowerCase => ("to_ascii_lowercase", bad_case_str.to_ascii_lowercase()),
++ CaseMethod::UpperCase => ("to_uppercase", bad_case_str.to_uppercase()),
++ CaseMethod::AsciiUppercase => ("to_ascii_uppercase", bad_case_str.to_ascii_uppercase()),
++ };
++
++ span_lint_and_sugg(
++ cx,
++ MATCH_STR_CASE_MISMATCH,
++ bad_case_span,
++ "this `match` arm has a differing case than its expression",
++ &*format!("consider changing the case of this arm to respect `{}`", method_str),
++ format!("\"{}\"", suggestion),
++ Applicability::MachineApplicable,
++ );
++}
--- /dev/null
- use clippy_utils::{meets_msrv, msrvs};
+use clippy_utils::source::{snippet_opt, span_starts_with, walk_span_to_context};
- use rustc_lint::{LateContext, LateLintPass};
++use clippy_utils::{higher, in_constant, meets_msrv, msrvs};
+use rustc_hir::{Arm, Expr, ExprKind, Local, MatchSource, Pat};
+use rustc_lexer::{tokenize, TokenKind};
- if expr.span.from_expansion() {
++use rustc_lint::{LateContext, LateLintPass, LintContext};
++use rustc_middle::lint::in_external_macro;
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::{Span, SpanData, SyntaxContext};
+
++mod collapsible_match;
+mod infallible_destructuring_match;
++mod manual_map;
++mod manual_unwrap_or;
+mod match_as_ref;
+mod match_bool;
+mod match_like_matches;
++mod match_on_vec_items;
+mod match_ref_pats;
+mod match_same_arms;
+mod match_single_binding;
++mod match_str_case_mismatch;
+mod match_wild_enum;
+mod match_wild_err_arm;
+mod needless_match;
+mod overlapping_arms;
+mod redundant_pattern_match;
+mod rest_pat_in_fully_bound_struct;
++mod significant_drop_in_scrutinee;
+mod single_match;
++mod try_err;
+mod wild_in_or_pats;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for matches with a single arm where an `if let`
+ /// will usually suffice.
+ ///
+ /// ### Why is this bad?
+ /// Just readability – `if let` nests less than a `match`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # fn bar(stool: &str) {}
+ /// # let x = Some("abc");
+ /// // Bad
+ /// match x {
+ /// Some(ref foo) => bar(foo),
+ /// _ => (),
+ /// }
+ ///
+ /// // Good
+ /// if let Some(ref foo) = x {
+ /// bar(foo);
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub SINGLE_MATCH,
+ style,
+ "a `match` statement with a single nontrivial arm (i.e., where the other arm is `_ => {}`) instead of `if let`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for matches with two arms where an `if let else` will
+ /// usually suffice.
+ ///
+ /// ### Why is this bad?
+ /// Just readability – `if let` nests less than a `match`.
+ ///
+ /// ### Known problems
+ /// Personal style preferences may differ.
+ ///
+ /// ### Example
+ /// Using `match`:
+ ///
+ /// ```rust
+ /// # fn bar(foo: &usize) {}
+ /// # let other_ref: usize = 1;
+ /// # let x: Option<&usize> = Some(&1);
+ /// match x {
+ /// Some(ref foo) => bar(foo),
+ /// _ => bar(&other_ref),
+ /// }
+ /// ```
+ ///
+ /// Using `if let` with `else`:
+ ///
+ /// ```rust
+ /// # fn bar(foo: &usize) {}
+ /// # let other_ref: usize = 1;
+ /// # let x: Option<&usize> = Some(&1);
+ /// if let Some(ref foo) = x {
+ /// bar(foo);
+ /// } else {
+ /// bar(&other_ref);
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub SINGLE_MATCH_ELSE,
+ pedantic,
+ "a `match` statement with two arms where the second arm's pattern is a placeholder instead of a specific match pattern"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for matches where all arms match a reference,
+ /// suggesting to remove the reference and deref the matched expression
+ /// instead. It also checks for `if let &foo = bar` blocks.
+ ///
+ /// ### Why is this bad?
+ /// It just makes the code less readable. That reference
+ /// destructuring adds nothing to the code.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// // Bad
+ /// match x {
+ /// &A(ref y) => foo(y),
+ /// &B => bar(),
+ /// _ => frob(&x),
+ /// }
+ ///
+ /// // Good
+ /// match *x {
+ /// A(ref y) => foo(y),
+ /// B => bar(),
+ /// _ => frob(x),
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MATCH_REF_PATS,
+ style,
+ "a `match` or `if let` with all arms prefixed with `&` instead of deref-ing the match expression"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for matches where match expression is a `bool`. It
+ /// suggests to replace the expression with an `if...else` block.
+ ///
+ /// ### Why is this bad?
+ /// It makes the code less readable.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # fn foo() {}
+ /// # fn bar() {}
+ /// let condition: bool = true;
+ /// match condition {
+ /// true => foo(),
+ /// false => bar(),
+ /// }
+ /// ```
+ /// Use if/else instead:
+ /// ```rust
+ /// # fn foo() {}
+ /// # fn bar() {}
+ /// let condition: bool = true;
+ /// if condition {
+ /// foo();
+ /// } else {
+ /// bar();
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MATCH_BOOL,
+ pedantic,
+ "a `match` on a boolean expression instead of an `if..else` block"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for overlapping match arms.
+ ///
+ /// ### Why is this bad?
+ /// It is likely to be an error and if not, makes the code
+ /// less obvious.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = 5;
+ /// match x {
+ /// 1..=10 => println!("1 ... 10"),
+ /// 5..=15 => println!("5 ... 15"),
+ /// _ => (),
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MATCH_OVERLAPPING_ARM,
+ style,
+ "a `match` with overlapping arms"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for arm which matches all errors with `Err(_)`
+ /// and take drastic actions like `panic!`.
+ ///
+ /// ### Why is this bad?
+ /// It is generally a bad practice, similar to
+ /// catching all exceptions in java with `catch(Exception)`
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x: Result<i32, &str> = Ok(3);
+ /// match x {
+ /// Ok(_) => println!("ok"),
+ /// Err(_) => panic!("err"),
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MATCH_WILD_ERR_ARM,
+ pedantic,
+ "a `match` with `Err(_)` arm and take drastic actions"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for match which is used to add a reference to an
+ /// `Option` value.
+ ///
+ /// ### Why is this bad?
+ /// Using `as_ref()` or `as_mut()` instead is shorter.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x: Option<()> = None;
+ ///
+ /// // Bad
+ /// let r: Option<&()> = match x {
+ /// None => None,
+ /// Some(ref v) => Some(v),
+ /// };
+ ///
+ /// // Good
+ /// let r: Option<&()> = x.as_ref();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MATCH_AS_REF,
+ complexity,
+ "a `match` on an Option value instead of using `as_ref()` or `as_mut`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for wildcard enum matches using `_`.
+ ///
+ /// ### Why is this bad?
+ /// New enum variants added by library updates can be missed.
+ ///
+ /// ### Known problems
+ /// Suggested replacements may be incorrect if guards exhaustively cover some
+ /// variants, and also may not use correct path to enum if it's not present in the current scope.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # enum Foo { A(usize), B(usize) }
+ /// # let x = Foo::B(1);
+ /// // Bad
+ /// match x {
+ /// Foo::A(_) => {},
+ /// _ => {},
+ /// }
+ ///
+ /// // Good
+ /// match x {
+ /// Foo::A(_) => {},
+ /// Foo::B(_) => {},
+ /// }
+ /// ```
+ #[clippy::version = "1.34.0"]
+ pub WILDCARD_ENUM_MATCH_ARM,
+ restriction,
+ "a wildcard enum match arm using `_`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for wildcard enum matches for a single variant.
+ ///
+ /// ### Why is this bad?
+ /// New enum variants added by library updates can be missed.
+ ///
+ /// ### Known problems
+ /// Suggested replacements may not use correct path to enum
+ /// if it's not present in the current scope.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # enum Foo { A, B, C }
+ /// # let x = Foo::B;
+ /// // Bad
+ /// match x {
+ /// Foo::A => {},
+ /// Foo::B => {},
+ /// _ => {},
+ /// }
+ ///
+ /// // Good
+ /// match x {
+ /// Foo::A => {},
+ /// Foo::B => {},
+ /// Foo::C => {},
+ /// }
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub MATCH_WILDCARD_FOR_SINGLE_VARIANTS,
+ pedantic,
+ "a wildcard enum match for a single variant"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for wildcard pattern used with others patterns in same match arm.
+ ///
+ /// ### Why is this bad?
+ /// Wildcard pattern already covers any other pattern as it will match anyway.
+ /// It makes the code less readable, especially to spot wildcard pattern use in match arm.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// match "foo" {
+ /// "a" => {},
+ /// "bar" | _ => {},
+ /// }
+ ///
+ /// // Good
+ /// match "foo" {
+ /// "a" => {},
+ /// _ => {},
+ /// }
+ /// ```
+ #[clippy::version = "1.42.0"]
+ pub WILDCARD_IN_OR_PATTERNS,
+ complexity,
+ "a wildcard pattern used with others patterns in same match arm"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for matches being used to destructure a single-variant enum
+ /// or tuple struct where a `let` will suffice.
+ ///
+ /// ### Why is this bad?
+ /// Just readability – `let` doesn't nest, whereas a `match` does.
+ ///
+ /// ### Example
+ /// ```rust
+ /// enum Wrapper {
+ /// Data(i32),
+ /// }
+ ///
+ /// let wrapper = Wrapper::Data(42);
+ ///
+ /// let data = match wrapper {
+ /// Wrapper::Data(i) => i,
+ /// };
+ /// ```
+ ///
+ /// The correct use would be:
+ /// ```rust
+ /// enum Wrapper {
+ /// Data(i32),
+ /// }
+ ///
+ /// let wrapper = Wrapper::Data(42);
+ /// let Wrapper::Data(data) = wrapper;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub INFALLIBLE_DESTRUCTURING_MATCH,
+ style,
+ "a `match` statement with a single infallible arm instead of a `let`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for useless match that binds to only one value.
+ ///
+ /// ### Why is this bad?
+ /// Readability and needless complexity.
+ ///
+ /// ### Known problems
+ /// Suggested replacements may be incorrect when `match`
+ /// is actually binding temporary value, bringing a 'dropped while borrowed' error.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let a = 1;
+ /// # let b = 2;
+ ///
+ /// // Bad
+ /// match (a, b) {
+ /// (c, d) => {
+ /// // useless match
+ /// }
+ /// }
+ ///
+ /// // Good
+ /// let (c, d) = (a, b);
+ /// ```
+ #[clippy::version = "1.43.0"]
+ pub MATCH_SINGLE_BINDING,
+ complexity,
+ "a match with a single binding instead of using `let` statement"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for unnecessary '..' pattern binding on struct when all fields are explicitly matched.
+ ///
+ /// ### Why is this bad?
+ /// Correctness and readability. It's like having a wildcard pattern after
+ /// matching all enum variants explicitly.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # struct A { a: i32 }
+ /// let a = A { a: 5 };
+ ///
+ /// // Bad
+ /// match a {
+ /// A { a: 5, .. } => {},
+ /// _ => {},
+ /// }
+ ///
+ /// // Good
+ /// match a {
+ /// A { a: 5 } => {},
+ /// _ => {},
+ /// }
+ /// ```
+ #[clippy::version = "1.43.0"]
+ pub REST_PAT_IN_FULLY_BOUND_STRUCTS,
+ restriction,
+ "a match on a struct that binds all fields but still uses the wildcard pattern"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Lint for redundant pattern matching over `Result`, `Option`,
+ /// `std::task::Poll` or `std::net::IpAddr`
+ ///
+ /// ### Why is this bad?
+ /// It's more concise and clear to just use the proper
+ /// utility function
+ ///
+ /// ### Known problems
+ /// This will change the drop order for the matched type. Both `if let` and
+ /// `while let` will drop the value at the end of the block, both `if` and `while` will drop the
+ /// value before entering the block. For most types this change will not matter, but for a few
+ /// types this will not be an acceptable change (e.g. locks). See the
+ /// [reference](https://doc.rust-lang.org/reference/destructors.html#drop-scopes) for more about
+ /// drop order.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::task::Poll;
+ /// # use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+ /// if let Ok(_) = Ok::<i32, i32>(42) {}
+ /// if let Err(_) = Err::<i32, i32>(42) {}
+ /// if let None = None::<()> {}
+ /// if let Some(_) = Some(42) {}
+ /// if let Poll::Pending = Poll::Pending::<()> {}
+ /// if let Poll::Ready(_) = Poll::Ready(42) {}
+ /// if let IpAddr::V4(_) = IpAddr::V4(Ipv4Addr::LOCALHOST) {}
+ /// if let IpAddr::V6(_) = IpAddr::V6(Ipv6Addr::LOCALHOST) {}
+ /// match Ok::<i32, i32>(42) {
+ /// Ok(_) => true,
+ /// Err(_) => false,
+ /// };
+ /// ```
+ ///
+ /// The more idiomatic use would be:
+ ///
+ /// ```rust
+ /// # use std::task::Poll;
+ /// # use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+ /// if Ok::<i32, i32>(42).is_ok() {}
+ /// if Err::<i32, i32>(42).is_err() {}
+ /// if None::<()>.is_none() {}
+ /// if Some(42).is_some() {}
+ /// if Poll::Pending::<()>.is_pending() {}
+ /// if Poll::Ready(42).is_ready() {}
+ /// if IpAddr::V4(Ipv4Addr::LOCALHOST).is_ipv4() {}
+ /// if IpAddr::V6(Ipv6Addr::LOCALHOST).is_ipv6() {}
+ /// Ok::<i32, i32>(42).is_ok();
+ /// ```
+ #[clippy::version = "1.31.0"]
+ pub REDUNDANT_PATTERN_MATCHING,
+ style,
+ "use the proper utility function avoiding an `if let`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `match` or `if let` expressions producing a
+ /// `bool` that could be written using `matches!`
+ ///
+ /// ### Why is this bad?
+ /// Readability and needless complexity.
+ ///
+ /// ### Known problems
+ /// This lint falsely triggers, if there are arms with
+ /// `cfg` attributes that remove an arm evaluating to `false`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = Some(5);
+ ///
+ /// // Bad
+ /// let a = match x {
+ /// Some(0) => true,
+ /// _ => false,
+ /// };
+ ///
+ /// let a = if let Some(0) = x {
+ /// true
+ /// } else {
+ /// false
+ /// };
+ ///
+ /// // Good
+ /// let a = matches!(x, Some(0));
+ /// ```
+ #[clippy::version = "1.47.0"]
+ pub MATCH_LIKE_MATCHES_MACRO,
+ style,
+ "a match that could be written with the matches! macro"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `match` with identical arm bodies.
+ ///
+ /// ### Why is this bad?
+ /// This is probably a copy & paste error. If arm bodies
+ /// are the same on purpose, you can factor them
+ /// [using `|`](https://doc.rust-lang.org/book/patterns.html#multiple-patterns).
+ ///
+ /// ### Known problems
+ /// False positive possible with order dependent `match`
+ /// (see issue
+ /// [#860](https://github.com/rust-lang/rust-clippy/issues/860)).
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// match foo {
+ /// Bar => bar(),
+ /// Quz => quz(),
+ /// Baz => bar(), // <= oops
+ /// }
+ /// ```
+ ///
+ /// This should probably be
+ /// ```rust,ignore
+ /// match foo {
+ /// Bar => bar(),
+ /// Quz => quz(),
+ /// Baz => baz(), // <= fixed
+ /// }
+ /// ```
+ ///
+ /// or if the original code was not a typo:
+ /// ```rust,ignore
+ /// match foo {
+ /// Bar | Baz => bar(), // <= shows the intent better
+ /// Quz => quz(),
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MATCH_SAME_ARMS,
+ pedantic,
+ "`match` with identical arm bodies"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for unnecessary `match` or match-like `if let` returns for `Option` and `Result`
+ /// when function signatures are the same.
+ ///
+ /// ### Why is this bad?
+ /// This `match` block does nothing and might not be what the coder intended.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// fn foo() -> Result<(), i32> {
+ /// match result {
+ /// Ok(val) => Ok(val),
+ /// Err(err) => Err(err),
+ /// }
+ /// }
+ ///
+ /// fn bar() -> Option<i32> {
+ /// if let Some(val) = option {
+ /// Some(val)
+ /// } else {
+ /// None
+ /// }
+ /// }
+ /// ```
+ ///
+ /// Could be replaced as
+ ///
+ /// ```rust,ignore
+ /// fn foo() -> Result<(), i32> {
+ /// result
+ /// }
+ ///
+ /// fn bar() -> Option<i32> {
+ /// option
+ /// }
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub NEEDLESS_MATCH,
+ complexity,
+ "`match` or match-like `if let` that are unnecessary"
+}
+
++declare_clippy_lint! {
++ /// ### What it does
++ /// Finds nested `match` or `if let` expressions where the patterns may be "collapsed" together
++ /// without adding any branches.
++ ///
++ /// Note that this lint is not intended to find _all_ cases where nested match patterns can be merged, but only
++ /// cases where merging would most likely make the code more readable.
++ ///
++ /// ### Why is this bad?
++ /// It is unnecessarily verbose and complex.
++ ///
++ /// ### Example
++ /// ```rust
++ /// fn func(opt: Option<Result<u64, String>>) {
++ /// let n = match opt {
++ /// Some(n) => match n {
++ /// Ok(n) => n,
++ /// _ => return,
++ /// }
++ /// None => return,
++ /// };
++ /// }
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// fn func(opt: Option<Result<u64, String>>) {
++ /// let n = match opt {
++ /// Some(Ok(n)) => n,
++ /// _ => return,
++ /// };
++ /// }
++ /// ```
++ #[clippy::version = "1.50.0"]
++ pub COLLAPSIBLE_MATCH,
++ style,
++ "Nested `match` or `if let` expressions where the patterns may be \"collapsed\" together."
++}
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Finds patterns that reimplement `Option::unwrap_or` or `Result::unwrap_or`.
++ ///
++ /// ### Why is this bad?
++ /// Concise code helps focusing on behavior instead of boilerplate.
++ ///
++ /// ### Example
++ /// ```rust
++ /// let foo: Option<i32> = None;
++ /// match foo {
++ /// Some(v) => v,
++ /// None => 1,
++ /// };
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// let foo: Option<i32> = None;
++ /// foo.unwrap_or(1);
++ /// ```
++ #[clippy::version = "1.49.0"]
++ pub MANUAL_UNWRAP_OR,
++ complexity,
++ "finds patterns that can be encoded more concisely with `Option::unwrap_or` or `Result::unwrap_or`"
++}
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for `match vec[idx]` or `match vec[n..m]`.
++ ///
++ /// ### Why is this bad?
++ /// This can panic at runtime.
++ ///
++ /// ### Example
++ /// ```rust, no_run
++ /// let arr = vec![0, 1, 2, 3];
++ /// let idx = 1;
++ ///
++ /// // Bad
++ /// match arr[idx] {
++ /// 0 => println!("{}", 0),
++ /// 1 => println!("{}", 3),
++ /// _ => {},
++ /// }
++ /// ```
++ /// Use instead:
++ /// ```rust, no_run
++ /// let arr = vec![0, 1, 2, 3];
++ /// let idx = 1;
++ ///
++ /// // Good
++ /// match arr.get(idx) {
++ /// Some(0) => println!("{}", 0),
++ /// Some(1) => println!("{}", 3),
++ /// _ => {},
++ /// }
++ /// ```
++ #[clippy::version = "1.45.0"]
++ pub MATCH_ON_VEC_ITEMS,
++ pedantic,
++ "matching on vector elements can panic"
++}
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for `match` expressions modifying the case of a string with non-compliant arms
++ ///
++ /// ### Why is this bad?
++ /// The arm is unreachable, which is likely a mistake
++ ///
++ /// ### Example
++ /// ```rust
++ /// # let text = "Foo";
++ /// match &*text.to_ascii_lowercase() {
++ /// "foo" => {},
++ /// "Bar" => {},
++ /// _ => {},
++ /// }
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// # let text = "Foo";
++ /// match &*text.to_ascii_lowercase() {
++ /// "foo" => {},
++ /// "bar" => {},
++ /// _ => {},
++ /// }
++ /// ```
++ #[clippy::version = "1.58.0"]
++ pub MATCH_STR_CASE_MISMATCH,
++ correctness,
++ "creation of a case altering match expression with non-compliant arms"
++}
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Check for temporaries returned from function calls in a match scrutinee that have the
++ /// `clippy::has_significant_drop` attribute.
++ ///
++ /// ### Why is this bad?
++ /// The `clippy::has_significant_drop` attribute can be added to types whose Drop impls have
++ /// an important side-effect, such as unlocking a mutex, making it important for users to be
++ /// able to accurately understand their lifetimes. When a temporary is returned in a function
++ /// call in a match scrutinee, its lifetime lasts until the end of the match block, which may
++ /// be surprising.
++ ///
++ /// For `Mutex`es this can lead to a deadlock. This happens when the match scrutinee uses a
++ /// function call that returns a `MutexGuard` and then tries to lock again in one of the match
++ /// arms. In that case the `MutexGuard` in the scrutinee will not be dropped until the end of
++ /// the match block and thus will not unlock.
++ ///
++ /// ### Example
++ /// ```rust.ignore
++ /// # use std::sync::Mutex;
++ ///
++ /// # struct State {}
++ ///
++ /// # impl State {
++ /// # fn foo(&self) -> bool {
++ /// # true
++ /// # }
++ ///
++ /// # fn bar(&self) {}
++ /// # }
++ ///
++ ///
++ /// let mutex = Mutex::new(State {});
++ ///
++ /// match mutex.lock().unwrap().foo() {
++ /// true => {
++ /// mutex.lock().unwrap().bar(); // Deadlock!
++ /// }
++ /// false => {}
++ /// };
++ ///
++ /// println!("All done!");
++ ///
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// # use std::sync::Mutex;
++ ///
++ /// # struct State {}
++ ///
++ /// # impl State {
++ /// # fn foo(&self) -> bool {
++ /// # true
++ /// # }
++ ///
++ /// # fn bar(&self) {}
++ /// # }
++ ///
++ /// let mutex = Mutex::new(State {});
++ ///
++ /// let is_foo = mutex.lock().unwrap().foo();
++ /// match is_foo {
++ /// true => {
++ /// mutex.lock().unwrap().bar();
++ /// }
++ /// false => {}
++ /// };
++ ///
++ /// println!("All done!");
++ /// ```
++ #[clippy::version = "1.60.0"]
++ pub SIGNIFICANT_DROP_IN_SCRUTINEE,
++ suspicious,
++ "warns when a temporary of a type with a drop with a significant side-effect might have a surprising lifetime"
++}
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for usages of `Err(x)?`.
++ ///
++ /// ### Why is this bad?
++ /// The `?` operator is designed to allow calls that
++ /// can fail to be easily chained. For example, `foo()?.bar()` or
++ /// `foo(bar()?)`. Because `Err(x)?` can't be used that way (it will
++ /// always return), it is more clear to write `return Err(x)`.
++ ///
++ /// ### Example
++ /// ```rust
++ /// fn foo(fail: bool) -> Result<i32, String> {
++ /// if fail {
++ /// Err("failed")?;
++ /// }
++ /// Ok(0)
++ /// }
++ /// ```
++ /// Could be written:
++ ///
++ /// ```rust
++ /// fn foo(fail: bool) -> Result<i32, String> {
++ /// if fail {
++ /// return Err("failed".into());
++ /// }
++ /// Ok(0)
++ /// }
++ /// ```
++ #[clippy::version = "1.38.0"]
++ pub TRY_ERR,
++ restriction,
++ "return errors explicitly rather than hiding them behind a `?`"
++}
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for usages of `match` which could be implemented using `map`
++ ///
++ /// ### Why is this bad?
++ /// Using the `map` method is clearer and more concise.
++ ///
++ /// ### Example
++ /// ```rust
++ /// match Some(0) {
++ /// Some(x) => Some(x + 1),
++ /// None => None,
++ /// };
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// Some(0).map(|x| x + 1);
++ /// ```
++ #[clippy::version = "1.52.0"]
++ pub MANUAL_MAP,
++ style,
++ "reimplementation of `map`"
++}
++
+#[derive(Default)]
+pub struct Matches {
+ msrv: Option<RustcVersion>,
+ infallible_destructuring_match_linted: bool,
+}
+
+impl Matches {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self {
+ msrv,
+ ..Matches::default()
+ }
+ }
+}
+
+impl_lint_pass!(Matches => [
+ SINGLE_MATCH,
+ MATCH_REF_PATS,
+ MATCH_BOOL,
+ SINGLE_MATCH_ELSE,
+ MATCH_OVERLAPPING_ARM,
+ MATCH_WILD_ERR_ARM,
+ MATCH_AS_REF,
+ WILDCARD_ENUM_MATCH_ARM,
+ MATCH_WILDCARD_FOR_SINGLE_VARIANTS,
+ WILDCARD_IN_OR_PATTERNS,
+ MATCH_SINGLE_BINDING,
+ INFALLIBLE_DESTRUCTURING_MATCH,
+ REST_PAT_IN_FULLY_BOUND_STRUCTS,
+ REDUNDANT_PATTERN_MATCHING,
+ MATCH_LIKE_MATCHES_MACRO,
+ MATCH_SAME_ARMS,
+ NEEDLESS_MATCH,
++ COLLAPSIBLE_MATCH,
++ MANUAL_UNWRAP_OR,
++ MATCH_ON_VEC_ITEMS,
++ MATCH_STR_CASE_MISMATCH,
++ SIGNIFICANT_DROP_IN_SCRUTINEE,
++ TRY_ERR,
++ MANUAL_MAP,
+]);
+
+impl<'tcx> LateLintPass<'tcx> for Matches {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
- if !span_starts_with(cx, expr.span, "match") {
++ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
++ let from_expansion = expr.span.from_expansion();
+
+ if let ExprKind::Match(ex, arms, source) = expr.kind {
- if !contains_cfg_arm(cx, expr, ex, arms) {
++ if source == MatchSource::Normal && !span_starts_with(cx, expr.span, "match") {
+ return;
+ }
-
- // These don't depend on a relationship between multiple arms
- match_wild_err_arm::check(cx, ex, arms);
- wild_in_or_pats::check(cx, arms);
- } else {
- if meets_msrv(self.msrv, msrvs::MATCHES_MACRO) {
- match_like_matches::check(cx, expr);
++ if matches!(source, MatchSource::Normal | MatchSource::ForLoopDesugar) {
++ significant_drop_in_scrutinee::check(cx, expr, ex, source);
++ }
++
++ collapsible_match::check_match(cx, arms);
++ if !from_expansion {
++ // These don't depend on a relationship between multiple arms
++ match_wild_err_arm::check(cx, ex, arms);
++ wild_in_or_pats::check(cx, arms);
++ }
++
++ if source == MatchSource::TryDesugar {
++ try_err::check(cx, expr, ex);
++ }
++
++ if !from_expansion && !contains_cfg_arm(cx, expr, ex, arms) {
+ if source == MatchSource::Normal {
+ if !(meets_msrv(self.msrv, msrvs::MATCHES_MACRO)
+ && match_like_matches::check_match(cx, expr, ex, arms))
+ {
+ match_same_arms::check(cx, arms);
+ }
+
+ redundant_pattern_match::check_match(cx, expr, ex, arms);
+ single_match::check(cx, ex, arms, expr);
+ match_bool::check(cx, ex, arms, expr);
+ overlapping_arms::check(cx, ex, arms);
+ match_wild_enum::check(cx, ex, arms);
+ match_as_ref::check(cx, ex, arms, expr);
+ needless_match::check_match(cx, ex, arms, expr);
++ match_on_vec_items::check(cx, ex);
++ match_str_case_mismatch::check(cx, ex, arms);
++
++ if !in_constant(cx, expr.hir_id) {
++ manual_unwrap_or::check(cx, expr, ex, arms);
++ manual_map::check_match(cx, expr, ex, arms);
++ }
+
+ if self.infallible_destructuring_match_linted {
+ self.infallible_destructuring_match_linted = false;
+ } else {
+ match_single_binding::check(cx, ex, arms, expr);
+ }
+ }
+ match_ref_pats::check(cx, ex, arms.iter().map(|el| el.pat), expr);
+ }
- needless_match::check(cx, expr);
++ } else if let Some(if_let) = higher::IfLet::hir(cx, expr) {
++ collapsible_match::check_if_let(cx, if_let.let_pat, if_let.if_then, if_let.if_else);
++ if !from_expansion {
++ if let Some(else_expr) = if_let.if_else {
++ if meets_msrv(self.msrv, msrvs::MATCHES_MACRO) {
++ match_like_matches::check_if_let(
++ cx,
++ expr,
++ if_let.let_pat,
++ if_let.let_expr,
++ if_let.if_then,
++ else_expr,
++ );
++ }
++ if !in_constant(cx, expr.hir_id) {
++ manual_map::check_if_let(cx, expr, if_let.let_pat, if_let.let_expr, if_let.if_then, else_expr);
++ }
++ }
++ redundant_pattern_match::check_if_let(
++ cx,
++ expr,
++ if_let.let_pat,
++ if_let.let_expr,
++ if_let.if_else.is_some(),
++ );
++ needless_match::check_if_let(cx, expr, &if_let);
+ }
++ } else if !from_expansion {
+ redundant_pattern_match::check(cx, expr);
+ }
+ }
+
+ fn check_local(&mut self, cx: &LateContext<'tcx>, local: &'tcx Local<'_>) {
+ self.infallible_destructuring_match_linted |= infallible_destructuring_match::check(cx, local);
+ }
+
+ fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) {
+ rest_pat_in_fully_bound_struct::check(cx, pat);
+ }
+
+ extract_msrv_attr!(LateContext);
+}
+
+/// Checks if there are any arms with a `#[cfg(..)]` attribute.
+fn contains_cfg_arm(cx: &LateContext<'_>, e: &Expr<'_>, scrutinee: &Expr<'_>, arms: &[Arm<'_>]) -> bool {
+ let Some(scrutinee_span) = walk_span_to_context(scrutinee.span, SyntaxContext::root()) else {
+ // Shouldn't happen, but treat this as though a `cfg` attribute were found
+ return true;
+ };
+
+ let start = scrutinee_span.hi();
+ let mut arm_spans = arms.iter().map(|arm| {
+ let data = arm.span.data();
+ (data.ctxt == SyntaxContext::root()).then(|| (data.lo, data.hi))
+ });
+ let end = e.span.hi();
+
+ // Walk through all the non-code space before each match arm. The space trailing the final arm is
+ // handled after the `try_fold` e.g.
+ //
+ // match foo {
+ // _________^- everything between the scrutinee and arm1
+ //| arm1 => (),
+ //|---^___________^ everything before arm2
+ //| #[cfg(feature = "enabled")]
+ //| arm2 => some_code(),
+ //|---^____________________^ everything before arm3
+ //| // some comment about arm3
+ //| arm3 => some_code(),
+ //|---^____________________^ everything after arm3
+ //| #[cfg(feature = "disabled")]
+ //| arm4 = some_code(),
+ //|};
+ //|^
+ let found = arm_spans.try_fold(start, |start, range| {
+ let Some((end, next_start)) = range else {
+ // Shouldn't happen as macros can't expand to match arms, but treat this as though a `cfg` attribute were
+ // found.
+ return Err(());
+ };
+ let span = SpanData {
+ lo: start,
+ hi: end,
+ ctxt: SyntaxContext::root(),
+ parent: None,
+ }
+ .span();
+ (!span_contains_cfg(cx, span)).then(|| next_start).ok_or(())
+ });
+ match found {
+ Ok(start) => {
+ let span = SpanData {
+ lo: start,
+ hi: end,
+ ctxt: SyntaxContext::root(),
+ parent: None,
+ }
+ .span();
+ span_contains_cfg(cx, span)
+ },
+ Err(()) => true,
+ }
+}
+
+/// Checks if the given span contains a `#[cfg(..)]` attribute
+fn span_contains_cfg(cx: &LateContext<'_>, s: Span) -> bool {
+ let Some(snip) = snippet_opt(cx, s) else {
+ // Assume true. This would require either an invalid span, or one which crosses file boundaries.
+ return true;
+ };
+ let mut pos = 0usize;
+ let mut iter = tokenize(&snip).map(|t| {
+ let start = pos;
+ pos += t.len;
+ (t.kind, start..pos)
+ });
+
+ // Search for the token sequence [`#`, `[`, `cfg`]
+ while iter.any(|(t, _)| matches!(t, TokenKind::Pound)) {
+ let mut iter = iter.by_ref().skip_while(|(t, _)| {
+ matches!(
+ t,
+ TokenKind::Whitespace | TokenKind::LineComment { .. } | TokenKind::BlockComment { .. }
+ )
+ });
+ if matches!(iter.next(), Some((TokenKind::OpenBracket, _)))
+ && matches!(iter.next(), Some((TokenKind::Ident, range)) if &snip[range.clone()] == "cfg")
+ {
+ return true;
+ }
+ }
+ false
+}
--- /dev/null
- pub(crate) fn check(cx: &LateContext<'_>, ex: &Expr<'_>) {
- if let Some(ref if_let) = higher::IfLet::hir(cx, ex) {
- if !is_else_clause(cx.tcx, ex) && expr_ty_matches_p_ty(cx, if_let.let_expr, ex) && check_if_let(cx, if_let) {
- let mut applicability = Applicability::MachineApplicable;
- span_lint_and_sugg(
- cx,
- NEEDLESS_MATCH,
- ex.span,
- "this if-let expression is unnecessary",
- "replace it with",
- snippet_with_applicability(cx, if_let.let_expr.span, "..", &mut applicability).to_string(),
- applicability,
- );
- }
+use super::NEEDLESS_MATCH;
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::ty::{is_type_diagnostic_item, same_type_and_consts};
+use clippy_utils::{
+ eq_expr_value, get_parent_expr_for_hir, get_parent_node, higher, is_else_clause, is_lang_ctor, over,
+ peel_blocks_with_stmt,
+};
+use rustc_errors::Applicability;
+use rustc_hir::LangItem::OptionNone;
+use rustc_hir::{Arm, BindingAnnotation, Expr, ExprKind, FnRetTy, Node, Pat, PatKind, Path, QPath};
+use rustc_lint::LateContext;
+use rustc_span::sym;
+use rustc_typeck::hir_ty_to_ty;
+
+pub(crate) fn check_match(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: &Expr<'_>) {
+ if arms.len() > 1 && expr_ty_matches_p_ty(cx, ex, expr) && check_all_arms(cx, ex, arms) {
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ NEEDLESS_MATCH,
+ expr.span,
+ "this match expression is unnecessary",
+ "replace it with",
+ snippet_with_applicability(cx, ex.span, "..", &mut applicability).to_string(),
+ applicability,
+ );
+ }
+}
+
+/// Check for nop `if let` expression that assembled as unnecessary match
+///
+/// ```rust,ignore
+/// if let Some(a) = option {
+/// Some(a)
+/// } else {
+/// None
+/// }
+/// ```
+/// OR
+/// ```rust,ignore
+/// if let SomeEnum::A = some_enum {
+/// SomeEnum::A
+/// } else if let SomeEnum::B = some_enum {
+/// SomeEnum::B
+/// } else {
+/// some_enum
+/// }
+/// ```
- fn check_if_let(cx: &LateContext<'_>, if_let: &higher::IfLet<'_>) -> bool {
++pub(crate) fn check_if_let<'tcx>(cx: &LateContext<'tcx>, ex: &Expr<'_>, if_let: &higher::IfLet<'tcx>) {
++ if !is_else_clause(cx.tcx, ex) && expr_ty_matches_p_ty(cx, if_let.let_expr, ex) && check_if_let_inner(cx, if_let) {
++ let mut applicability = Applicability::MachineApplicable;
++ span_lint_and_sugg(
++ cx,
++ NEEDLESS_MATCH,
++ ex.span,
++ "this if-let expression is unnecessary",
++ "replace it with",
++ snippet_with_applicability(cx, if_let.let_expr.span, "..", &mut applicability).to_string(),
++ applicability,
++ );
+ }
+}
+
+fn check_all_arms(cx: &LateContext<'_>, match_expr: &Expr<'_>, arms: &[Arm<'_>]) -> bool {
+ for arm in arms {
+ let arm_expr = peel_blocks_with_stmt(arm.body);
+ if let PatKind::Wild = arm.pat.kind {
+ return eq_expr_value(cx, match_expr, strip_return(arm_expr));
+ } else if !pat_same_as_expr(arm.pat, arm_expr) {
+ return false;
+ }
+ }
+
+ true
+}
+
- return check_if_let(cx, nested_if_let);
++fn check_if_let_inner(cx: &LateContext<'_>, if_let: &higher::IfLet<'_>) -> bool {
+ if let Some(if_else) = if_let.if_else {
+ if !pat_same_as_expr(if_let.let_pat, peel_blocks_with_stmt(if_let.if_then)) {
+ return false;
+ }
+
+ // Recursively check for each `else if let` phrase,
+ if let Some(ref nested_if_let) = higher::IfLet::hir(cx, if_else) {
++ return check_if_let_inner(cx, nested_if_let);
+ }
+
+ if matches!(if_else.kind, ExprKind::Block(..)) {
+ let else_expr = peel_blocks_with_stmt(if_else);
+ if matches!(else_expr.kind, ExprKind::Block(..)) {
+ return false;
+ }
+ let ret = strip_return(else_expr);
+ let let_expr_ty = cx.typeck_results().expr_ty(if_let.let_expr);
+ if is_type_diagnostic_item(cx, let_expr_ty, sym::Option) {
+ if let ExprKind::Path(ref qpath) = ret.kind {
+ return is_lang_ctor(cx, qpath, OptionNone) || eq_expr_value(cx, if_let.let_expr, ret);
+ }
+ return false;
+ }
+ return eq_expr_value(cx, if_let.let_expr, ret);
+ }
+ }
+
+ false
+}
+
+/// Strip `return` keyword if the expression type is `ExprKind::Ret`.
+fn strip_return<'hir>(expr: &'hir Expr<'hir>) -> &'hir Expr<'hir> {
+ if let ExprKind::Ret(Some(ret)) = expr.kind {
+ ret
+ } else {
+ expr
+ }
+}
+
+/// Manually check for coercion casting by checking if the type of the match operand or let expr
+/// differs with the assigned local variable or the function return type.
+fn expr_ty_matches_p_ty(cx: &LateContext<'_>, expr: &Expr<'_>, p_expr: &Expr<'_>) -> bool {
+ if let Some(p_node) = get_parent_node(cx.tcx, p_expr.hir_id) {
+ match p_node {
+ // Compare match_expr ty with local in `let local = match match_expr {..}`
+ Node::Local(local) => {
+ let results = cx.typeck_results();
+ return same_type_and_consts(results.node_type(local.hir_id), results.expr_ty(expr));
+ },
+ // compare match_expr ty with RetTy in `fn foo() -> RetTy`
+ Node::Item(..) => {
+ if let Some(fn_decl) = p_node.fn_decl() {
+ if let FnRetTy::Return(ret_ty) = fn_decl.output {
+ return same_type_and_consts(hir_ty_to_ty(cx.tcx, ret_ty), cx.typeck_results().expr_ty(expr));
+ }
+ }
+ },
+ // check the parent expr for this whole block `{ match match_expr {..} }`
+ Node::Block(block) => {
+ if let Some(block_parent_expr) = get_parent_expr_for_hir(cx, block.hir_id) {
+ return expr_ty_matches_p_ty(cx, expr, block_parent_expr);
+ }
+ },
+ // recursively call on `if xxx {..}` etc.
+ Node::Expr(p_expr) => {
+ return expr_ty_matches_p_ty(cx, expr, p_expr);
+ },
+ _ => {},
+ }
+ }
+ false
+}
+
+fn pat_same_as_expr(pat: &Pat<'_>, expr: &Expr<'_>) -> bool {
+ let expr = strip_return(expr);
+ match (&pat.kind, &expr.kind) {
+ // Example: `Some(val) => Some(val)`
+ (PatKind::TupleStruct(QPath::Resolved(_, path), tuple_params, _), ExprKind::Call(call_expr, call_params)) => {
+ if let ExprKind::Path(QPath::Resolved(_, call_path)) = call_expr.kind {
+ return over(path.segments, call_path.segments, |pat_seg, call_seg| {
+ pat_seg.ident.name == call_seg.ident.name
+ }) && same_non_ref_symbols(tuple_params, call_params);
+ }
+ },
+ // Example: `val => val`
+ (
+ PatKind::Binding(annot, _, pat_ident, _),
+ ExprKind::Path(QPath::Resolved(
+ _,
+ Path {
+ segments: [first_seg, ..],
+ ..
+ },
+ )),
+ ) => {
+ return !matches!(annot, BindingAnnotation::Ref | BindingAnnotation::RefMut)
+ && pat_ident.name == first_seg.ident.name;
+ },
+ // Example: `Custom::TypeA => Custom::TypeB`, or `None => None`
+ (PatKind::Path(QPath::Resolved(_, p_path)), ExprKind::Path(QPath::Resolved(_, e_path))) => {
+ return over(p_path.segments, e_path.segments, |p_seg, e_seg| {
+ p_seg.ident.name == e_seg.ident.name
+ });
+ },
+ // Example: `5 => 5`
+ (PatKind::Lit(pat_lit_expr), ExprKind::Lit(expr_spanned)) => {
+ if let ExprKind::Lit(pat_spanned) = &pat_lit_expr.kind {
+ return pat_spanned.node == expr_spanned.node;
+ }
+ },
+ _ => {},
+ }
+
+ false
+}
+
+fn same_non_ref_symbols(pats: &[Pat<'_>], exprs: &[Expr<'_>]) -> bool {
+ if pats.len() != exprs.len() {
+ return false;
+ }
+
+ for i in 0..pats.len() {
+ if !pat_same_as_expr(&pats[i], &exprs[i]) {
+ return false;
+ }
+ }
+
+ true
+}
--- /dev/null
- if let Some(higher::IfLet {
- if_else,
- let_pat,
- let_expr,
- ..
- }) = higher::IfLet::hir(cx, expr)
- {
- find_sugg_for_if_let(cx, expr, let_pat, let_expr, "if", if_else.is_some());
- } else if let Some(higher::WhileLet { let_pat, let_expr, .. }) = higher::WhileLet::hir(expr) {
+use super::REDUNDANT_PATTERN_MATCHING;
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::source::snippet;
+use clippy_utils::sugg::Sugg;
+use clippy_utils::ty::needs_ordered_drop;
+use clippy_utils::{higher, match_def_path};
+use clippy_utils::{is_lang_ctor, is_trait_method, paths};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::LangItem::{OptionNone, PollPending};
+use rustc_hir::{
+ intravisit::{walk_expr, Visitor},
+ Arm, Block, Expr, ExprKind, Node, Pat, PatKind, QPath, UnOp,
+};
+use rustc_lint::LateContext;
+use rustc_middle::ty::{self, subst::GenericArgKind, DefIdTree, Ty};
+use rustc_span::sym;
+
+pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
++ if let Some(higher::WhileLet { let_pat, let_expr, .. }) = higher::WhileLet::hir(expr) {
+ find_sugg_for_if_let(cx, expr, let_pat, let_expr, "while", false);
+ }
+}
+
++pub(super) fn check_if_let<'tcx>(
++ cx: &LateContext<'tcx>,
++ expr: &'tcx Expr<'_>,
++ pat: &'tcx Pat<'_>,
++ scrutinee: &'tcx Expr<'_>,
++ has_else: bool,
++) {
++ find_sugg_for_if_let(cx, expr, pat, scrutinee, "if", has_else);
++}
++
+// Extract the generic arguments out of a type
+fn try_get_generic_ty(ty: Ty<'_>, index: usize) -> Option<Ty<'_>> {
+ if_chain! {
+ if let ty::Adt(_, subs) = ty.kind();
+ if let Some(sub) = subs.get(index);
+ if let GenericArgKind::Type(sub_ty) = sub.unpack();
+ then {
+ Some(sub_ty)
+ } else {
+ None
+ }
+ }
+}
+
+// Checks if there are any temporaries created in the given expression for which drop order
+// matters.
+fn temporaries_need_ordered_drop<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> bool {
+ struct V<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ res: bool,
+ }
+ impl<'a, 'tcx> Visitor<'tcx> for V<'a, 'tcx> {
+ fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
+ match expr.kind {
+ // Taking the reference of a value leaves a temporary
+ // e.g. In `&String::new()` the string is a temporary value.
+ // Remaining fields are temporary values
+ // e.g. In `(String::new(), 0).1` the string is a temporary value.
+ ExprKind::AddrOf(_, _, expr) | ExprKind::Field(expr, _) => {
+ if !matches!(expr.kind, ExprKind::Path(_)) {
+ if needs_ordered_drop(self.cx, self.cx.typeck_results().expr_ty(expr)) {
+ self.res = true;
+ } else {
+ self.visit_expr(expr);
+ }
+ }
+ },
+ // the base type is alway taken by reference.
+ // e.g. In `(vec![0])[0]` the vector is a temporary value.
+ ExprKind::Index(base, index) => {
+ if !matches!(base.kind, ExprKind::Path(_)) {
+ if needs_ordered_drop(self.cx, self.cx.typeck_results().expr_ty(base)) {
+ self.res = true;
+ } else {
+ self.visit_expr(base);
+ }
+ }
+ self.visit_expr(index);
+ },
+ // Method calls can take self by reference.
+ // e.g. In `String::new().len()` the string is a temporary value.
+ ExprKind::MethodCall(_, [self_arg, args @ ..], _) => {
+ if !matches!(self_arg.kind, ExprKind::Path(_)) {
+ let self_by_ref = self
+ .cx
+ .typeck_results()
+ .type_dependent_def_id(expr.hir_id)
+ .map_or(false, |id| self.cx.tcx.fn_sig(id).skip_binder().inputs()[0].is_ref());
+ if self_by_ref && needs_ordered_drop(self.cx, self.cx.typeck_results().expr_ty(self_arg)) {
+ self.res = true;
+ } else {
+ self.visit_expr(self_arg);
+ }
+ }
+ args.iter().for_each(|arg| self.visit_expr(arg));
+ },
+ // Either explicitly drops values, or changes control flow.
+ ExprKind::DropTemps(_)
+ | ExprKind::Ret(_)
+ | ExprKind::Break(..)
+ | ExprKind::Yield(..)
+ | ExprKind::Block(Block { expr: None, .. }, _)
+ | ExprKind::Loop(..) => (),
+
+ // Only consider the final expression.
+ ExprKind::Block(Block { expr: Some(expr), .. }, _) => self.visit_expr(expr),
+
+ _ => walk_expr(self, expr),
+ }
+ }
+ }
+
+ let mut v = V { cx, res: false };
+ v.visit_expr(expr);
+ v.res
+}
+
+fn find_sugg_for_if_let<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx Expr<'_>,
+ let_pat: &Pat<'_>,
+ let_expr: &'tcx Expr<'_>,
+ keyword: &'static str,
+ has_else: bool,
+) {
+ // also look inside refs
+ // if we have &None for example, peel it so we can detect "if let None = x"
+ let check_pat = match let_pat.kind {
+ PatKind::Ref(inner, _mutability) => inner,
+ _ => let_pat,
+ };
+ let op_ty = cx.typeck_results().expr_ty(let_expr);
+ // Determine which function should be used, and the type contained by the corresponding
+ // variant.
+ let (good_method, inner_ty) = match check_pat.kind {
+ PatKind::TupleStruct(ref qpath, [sub_pat], _) => {
+ if let PatKind::Wild = sub_pat.kind {
+ let res = cx.typeck_results().qpath_res(qpath, check_pat.hir_id);
+ let Some(id) = res.opt_def_id().map(|ctor_id| cx.tcx.parent(ctor_id)) else { return };
+ let lang_items = cx.tcx.lang_items();
+ if Some(id) == lang_items.result_ok_variant() {
+ ("is_ok()", try_get_generic_ty(op_ty, 0).unwrap_or(op_ty))
+ } else if Some(id) == lang_items.result_err_variant() {
+ ("is_err()", try_get_generic_ty(op_ty, 1).unwrap_or(op_ty))
+ } else if Some(id) == lang_items.option_some_variant() {
+ ("is_some()", op_ty)
+ } else if Some(id) == lang_items.poll_ready_variant() {
+ ("is_ready()", op_ty)
+ } else if match_def_path(cx, id, &paths::IPADDR_V4) {
+ ("is_ipv4()", op_ty)
+ } else if match_def_path(cx, id, &paths::IPADDR_V6) {
+ ("is_ipv6()", op_ty)
+ } else {
+ return;
+ }
+ } else {
+ return;
+ }
+ },
+ PatKind::Path(ref path) => {
+ let method = if is_lang_ctor(cx, path, OptionNone) {
+ "is_none()"
+ } else if is_lang_ctor(cx, path, PollPending) {
+ "is_pending()"
+ } else {
+ return;
+ };
+ // `None` and `Pending` don't have an inner type.
+ (method, cx.tcx.types.unit)
+ },
+ _ => return,
+ };
+
+ // If this is the last expression in a block or there is an else clause then the whole
+ // type needs to be considered, not just the inner type of the branch being matched on.
+ // Note the last expression in a block is dropped after all local bindings.
+ let check_ty = if has_else
+ || (keyword == "if" && matches!(cx.tcx.hir().parent_iter(expr.hir_id).next(), Some((_, Node::Block(..)))))
+ {
+ op_ty
+ } else {
+ inner_ty
+ };
+
+ // All temporaries created in the scrutinee expression are dropped at the same time as the
+ // scrutinee would be, so they have to be considered as well.
+ // e.g. in `if let Some(x) = foo.lock().unwrap().baz.as_ref() { .. }` the lock will be held
+ // for the duration if body.
+ let needs_drop = needs_ordered_drop(cx, check_ty) || temporaries_need_ordered_drop(cx, let_expr);
+
+ // check that `while_let_on_iterator` lint does not trigger
+ if_chain! {
+ if keyword == "while";
+ if let ExprKind::MethodCall(method_path, _, _) = let_expr.kind;
+ if method_path.ident.name == sym::next;
+ if is_trait_method(cx, let_expr, sym::Iterator);
+ then {
+ return;
+ }
+ }
+
+ let result_expr = match &let_expr.kind {
+ ExprKind::AddrOf(_, _, borrowed) => borrowed,
+ ExprKind::Unary(UnOp::Deref, deref) => deref,
+ _ => let_expr,
+ };
+
+ span_lint_and_then(
+ cx,
+ REDUNDANT_PATTERN_MATCHING,
+ let_pat.span,
+ &format!("redundant pattern matching, consider using `{}`", good_method),
+ |diag| {
+ // if/while let ... = ... { ... }
+ // ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ let expr_span = expr.span;
+
+ // if/while let ... = ... { ... }
+ // ^^^
+ let op_span = result_expr.span.source_callsite();
+
+ // if/while let ... = ... { ... }
+ // ^^^^^^^^^^^^^^^^^^^
+ let span = expr_span.until(op_span.shrink_to_hi());
+
+ let app = if needs_drop {
+ Applicability::MaybeIncorrect
+ } else {
+ Applicability::MachineApplicable
+ };
+
+ let sugg = Sugg::hir_with_macro_callsite(cx, result_expr, "_")
+ .maybe_par()
+ .to_string();
+
+ diag.span_suggestion(span, "try this", format!("{} {}.{}", keyword, sugg, good_method), app);
+
+ if needs_drop {
+ diag.note("this will change drop order of the result, as well as all temporaries");
+ diag.note("add `#[allow(clippy::redundant_pattern_matching)]` if this is important");
+ }
+ },
+ );
+}
+
+pub(super) fn check_match<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, op: &Expr<'_>, arms: &[Arm<'_>]) {
+ if arms.len() == 2 {
+ let node_pair = (&arms[0].pat.kind, &arms[1].pat.kind);
+
+ let found_good_method = match node_pair {
+ (
+ PatKind::TupleStruct(ref path_left, patterns_left, _),
+ PatKind::TupleStruct(ref path_right, patterns_right, _),
+ ) if patterns_left.len() == 1 && patterns_right.len() == 1 => {
+ if let (PatKind::Wild, PatKind::Wild) = (&patterns_left[0].kind, &patterns_right[0].kind) {
+ find_good_method_for_match(
+ cx,
+ arms,
+ path_left,
+ path_right,
+ &paths::RESULT_OK,
+ &paths::RESULT_ERR,
+ "is_ok()",
+ "is_err()",
+ )
+ .or_else(|| {
+ find_good_method_for_match(
+ cx,
+ arms,
+ path_left,
+ path_right,
+ &paths::IPADDR_V4,
+ &paths::IPADDR_V6,
+ "is_ipv4()",
+ "is_ipv6()",
+ )
+ })
+ } else {
+ None
+ }
+ },
+ (PatKind::TupleStruct(ref path_left, patterns, _), PatKind::Path(ref path_right))
+ | (PatKind::Path(ref path_left), PatKind::TupleStruct(ref path_right, patterns, _))
+ if patterns.len() == 1 =>
+ {
+ if let PatKind::Wild = patterns[0].kind {
+ find_good_method_for_match(
+ cx,
+ arms,
+ path_left,
+ path_right,
+ &paths::OPTION_SOME,
+ &paths::OPTION_NONE,
+ "is_some()",
+ "is_none()",
+ )
+ .or_else(|| {
+ find_good_method_for_match(
+ cx,
+ arms,
+ path_left,
+ path_right,
+ &paths::POLL_READY,
+ &paths::POLL_PENDING,
+ "is_ready()",
+ "is_pending()",
+ )
+ })
+ } else {
+ None
+ }
+ },
+ _ => None,
+ };
+
+ if let Some(good_method) = found_good_method {
+ let span = expr.span.to(op.span);
+ let result_expr = match &op.kind {
+ ExprKind::AddrOf(_, _, borrowed) => borrowed,
+ _ => op,
+ };
+ span_lint_and_then(
+ cx,
+ REDUNDANT_PATTERN_MATCHING,
+ expr.span,
+ &format!("redundant pattern matching, consider using `{}`", good_method),
+ |diag| {
+ diag.span_suggestion(
+ span,
+ "try this",
+ format!("{}.{}", snippet(cx, result_expr.span, "_"), good_method),
+ Applicability::MaybeIncorrect, // snippet
+ );
+ },
+ );
+ }
+ }
+}
+
+#[expect(clippy::too_many_arguments)]
+fn find_good_method_for_match<'a>(
+ cx: &LateContext<'_>,
+ arms: &[Arm<'_>],
+ path_left: &QPath<'_>,
+ path_right: &QPath<'_>,
+ expected_left: &[&str],
+ expected_right: &[&str],
+ should_be_left: &'a str,
+ should_be_right: &'a str,
+) -> Option<&'a str> {
+ let left_id = cx
+ .typeck_results()
+ .qpath_res(path_left, arms[0].pat.hir_id)
+ .opt_def_id()?;
+ let right_id = cx
+ .typeck_results()
+ .qpath_res(path_right, arms[1].pat.hir_id)
+ .opt_def_id()?;
+ let body_node_pair = if match_def_path(cx, left_id, expected_left) && match_def_path(cx, right_id, expected_right) {
+ (&(*arms[0].body).kind, &(*arms[1].body).kind)
+ } else if match_def_path(cx, right_id, expected_left) && match_def_path(cx, right_id, expected_right) {
+ (&(*arms[1].body).kind, &(*arms[0].body).kind)
+ } else {
+ return None;
+ };
+
+ match body_node_pair {
+ (ExprKind::Lit(ref lit_left), ExprKind::Lit(ref lit_right)) => match (&lit_left.node, &lit_right.node) {
+ (LitKind::Bool(true), LitKind::Bool(false)) => Some(should_be_left),
+ (LitKind::Bool(false), LitKind::Bool(true)) => Some(should_be_right),
+ _ => None,
+ },
+ _ => None,
+ }
+}
--- /dev/null
--- /dev/null
++use crate::FxHashSet;
++use clippy_utils::diagnostics::span_lint_and_then;
++use clippy_utils::get_attr;
++use clippy_utils::source::{indent_of, snippet};
++use rustc_errors::{Applicability, Diagnostic};
++use rustc_hir::intravisit::{walk_expr, Visitor};
++use rustc_hir::{Expr, ExprKind, MatchSource};
++use rustc_lint::{LateContext, LintContext};
++use rustc_middle::ty::subst::GenericArgKind;
++use rustc_middle::ty::{Ty, TypeAndMut};
++use rustc_span::Span;
++
++use super::SIGNIFICANT_DROP_IN_SCRUTINEE;
++
++pub(super) fn check<'tcx>(
++ cx: &LateContext<'tcx>,
++ expr: &'tcx Expr<'tcx>,
++ scrutinee: &'tcx Expr<'_>,
++ source: MatchSource,
++) {
++ if let Some((suggestions, message)) = has_significant_drop_in_scrutinee(cx, scrutinee, source) {
++ for found in suggestions {
++ span_lint_and_then(cx, SIGNIFICANT_DROP_IN_SCRUTINEE, found.found_span, message, |diag| {
++ set_diagnostic(diag, cx, expr, found);
++ });
++ }
++ }
++}
++
++fn set_diagnostic<'tcx>(diag: &mut Diagnostic, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>, found: FoundSigDrop) {
++ if found.lint_suggestion == LintSuggestion::MoveAndClone {
++ // If our suggestion is to move and clone, then we want to leave it to the user to
++ // decide how to address this lint, since it may be that cloning is inappropriate.
++ // Therefore, we won't to emit a suggestion.
++ return;
++ }
++
++ let original = snippet(cx, found.found_span, "..");
++ let trailing_indent = " ".repeat(indent_of(cx, found.found_span).unwrap_or(0));
++
++ let replacement = if found.lint_suggestion == LintSuggestion::MoveAndDerefToCopy {
++ format!("let value = *{};\n{}", original, trailing_indent)
++ } else if found.is_unit_return_val {
++ // If the return value of the expression to be moved is unit, then we don't need to
++ // capture the result in a temporary -- we can just replace it completely with `()`.
++ format!("{};\n{}", original, trailing_indent)
++ } else {
++ format!("let value = {};\n{}", original, trailing_indent)
++ };
++
++ let suggestion_message = if found.lint_suggestion == LintSuggestion::MoveOnly {
++ "try moving the temporary above the match"
++ } else {
++ "try moving the temporary above the match and create a copy"
++ };
++
++ let scrutinee_replacement = if found.is_unit_return_val {
++ "()".to_owned()
++ } else {
++ "value".to_owned()
++ };
++
++ diag.multipart_suggestion(
++ suggestion_message,
++ vec![
++ (expr.span.shrink_to_lo(), replacement),
++ (found.found_span, scrutinee_replacement),
++ ],
++ Applicability::MaybeIncorrect,
++ );
++}
++
++/// If the expression is an `ExprKind::Match`, check if the scrutinee has a significant drop that
++/// may have a surprising lifetime.
++fn has_significant_drop_in_scrutinee<'tcx, 'a>(
++ cx: &'a LateContext<'tcx>,
++ scrutinee: &'tcx Expr<'tcx>,
++ source: MatchSource,
++) -> Option<(Vec<FoundSigDrop>, &'static str)> {
++ let mut helper = SigDropHelper::new(cx);
++ helper.find_sig_drop(scrutinee).map(|drops| {
++ let message = if source == MatchSource::Normal {
++ "temporary with significant drop in match scrutinee"
++ } else {
++ "temporary with significant drop in for loop"
++ };
++ (drops, message)
++ })
++}
++
++struct SigDropHelper<'a, 'tcx> {
++ cx: &'a LateContext<'tcx>,
++ is_chain_end: bool,
++ seen_types: FxHashSet<Ty<'tcx>>,
++ has_significant_drop: bool,
++ current_sig_drop: Option<FoundSigDrop>,
++ sig_drop_spans: Option<Vec<FoundSigDrop>>,
++ special_handling_for_binary_op: bool,
++}
++
++#[expect(clippy::enum_variant_names)]
++#[derive(Debug, PartialEq, Eq, Clone, Copy)]
++enum LintSuggestion {
++ MoveOnly,
++ MoveAndDerefToCopy,
++ MoveAndClone,
++}
++
++#[derive(Clone, Copy)]
++struct FoundSigDrop {
++ found_span: Span,
++ is_unit_return_val: bool,
++ lint_suggestion: LintSuggestion,
++}
++
++impl<'a, 'tcx> SigDropHelper<'a, 'tcx> {
++ fn new(cx: &'a LateContext<'tcx>) -> SigDropHelper<'a, 'tcx> {
++ SigDropHelper {
++ cx,
++ is_chain_end: true,
++ seen_types: FxHashSet::default(),
++ has_significant_drop: false,
++ current_sig_drop: None,
++ sig_drop_spans: None,
++ special_handling_for_binary_op: false,
++ }
++ }
++
++ fn find_sig_drop(&mut self, match_expr: &'tcx Expr<'_>) -> Option<Vec<FoundSigDrop>> {
++ self.visit_expr(match_expr);
++
++ // If sig drop spans is empty but we found a significant drop, it means that we didn't find
++ // a type that was trivially copyable as we moved up the chain after finding a significant
++ // drop, so move the entire scrutinee.
++ if self.has_significant_drop && self.sig_drop_spans.is_none() {
++ self.try_setting_current_suggestion(match_expr, true);
++ self.move_current_suggestion();
++ }
++
++ self.sig_drop_spans.take()
++ }
++
++ fn replace_current_sig_drop(
++ &mut self,
++ found_span: Span,
++ is_unit_return_val: bool,
++ lint_suggestion: LintSuggestion,
++ ) {
++ self.current_sig_drop.replace(FoundSigDrop {
++ found_span,
++ is_unit_return_val,
++ lint_suggestion,
++ });
++ }
++
++ /// This will try to set the current suggestion (so it can be moved into the suggestions vec
++ /// later). If `allow_move_and_clone` is false, the suggestion *won't* be set -- this gives us
++ /// an opportunity to look for another type in the chain that will be trivially copyable.
++ /// However, if we are at the the end of the chain, we want to accept whatever is there. (The
++ /// suggestion won't actually be output, but the diagnostic message will be output, so the user
++ /// can determine the best way to handle the lint.)
++ fn try_setting_current_suggestion(&mut self, expr: &'tcx Expr<'_>, allow_move_and_clone: bool) {
++ if self.current_sig_drop.is_some() {
++ return;
++ }
++ let ty = self.get_type(expr);
++ if ty.is_ref() {
++ // We checked that the type was ref, so builtin_deref will return Some TypeAndMut,
++ // but let's avoid any chance of an ICE
++ if let Some(TypeAndMut { ty, .. }) = ty.builtin_deref(true) {
++ if ty.is_trivially_pure_clone_copy() {
++ self.replace_current_sig_drop(expr.span, false, LintSuggestion::MoveAndDerefToCopy);
++ } else if allow_move_and_clone {
++ self.replace_current_sig_drop(expr.span, false, LintSuggestion::MoveAndClone);
++ }
++ }
++ } else if ty.is_trivially_pure_clone_copy() {
++ self.replace_current_sig_drop(expr.span, false, LintSuggestion::MoveOnly);
++ } else if allow_move_and_clone {
++ self.replace_current_sig_drop(expr.span, false, LintSuggestion::MoveAndClone);
++ }
++ }
++
++ fn move_current_suggestion(&mut self) {
++ if let Some(current) = self.current_sig_drop.take() {
++ self.sig_drop_spans.get_or_insert_with(Vec::new).push(current);
++ }
++ }
++
++ fn get_type(&self, ex: &'tcx Expr<'_>) -> Ty<'tcx> {
++ self.cx.typeck_results().expr_ty(ex)
++ }
++
++ fn has_seen_type(&mut self, ty: Ty<'tcx>) -> bool {
++ !self.seen_types.insert(ty)
++ }
++
++ fn visit_exprs_for_binary_ops(
++ &mut self,
++ left: &'tcx Expr<'_>,
++ right: &'tcx Expr<'_>,
++ is_unit_return_val: bool,
++ span: Span,
++ ) {
++ self.special_handling_for_binary_op = true;
++ self.visit_expr(left);
++ self.visit_expr(right);
++
++ // If either side had a significant drop, suggest moving the entire scrutinee to avoid
++ // unnecessary copies and to simplify cases where both sides have significant drops.
++ if self.has_significant_drop {
++ self.replace_current_sig_drop(span, is_unit_return_val, LintSuggestion::MoveOnly);
++ }
++
++ self.special_handling_for_binary_op = false;
++ }
++
++ fn has_sig_drop_attr(&mut self, cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
++ if let Some(adt) = ty.ty_adt_def() {
++ if get_attr(cx.sess(), cx.tcx.get_attrs_unchecked(adt.did()), "has_significant_drop").count() > 0 {
++ return true;
++ }
++ }
++
++ match ty.kind() {
++ rustc_middle::ty::Adt(a, b) => {
++ for f in a.all_fields() {
++ let ty = f.ty(cx.tcx, b);
++ if !self.has_seen_type(ty) && self.has_sig_drop_attr(cx, ty) {
++ return true;
++ }
++ }
++
++ for generic_arg in b.iter() {
++ if let GenericArgKind::Type(ty) = generic_arg.unpack() {
++ if self.has_sig_drop_attr(cx, ty) {
++ return true;
++ }
++ }
++ }
++ false
++ },
++ rustc_middle::ty::Array(ty, _)
++ | rustc_middle::ty::RawPtr(TypeAndMut { ty, .. })
++ | rustc_middle::ty::Ref(_, ty, _)
++ | rustc_middle::ty::Slice(ty) => self.has_sig_drop_attr(cx, *ty),
++ _ => false,
++ }
++ }
++}
++
++impl<'a, 'tcx> Visitor<'tcx> for SigDropHelper<'a, 'tcx> {
++ fn visit_expr(&mut self, ex: &'tcx Expr<'_>) {
++ if !self.is_chain_end && self.has_sig_drop_attr(self.cx, self.get_type(ex)) {
++ self.has_significant_drop = true;
++ return;
++ }
++ self.is_chain_end = false;
++
++ match ex.kind {
++ ExprKind::MethodCall(_, [ref expr, ..], _) => {
++ self.visit_expr(expr);
++ }
++ ExprKind::Binary(_, left, right) => {
++ self.visit_exprs_for_binary_ops(left, right, false, ex.span);
++ }
++ ExprKind::Assign(left, right, _) | ExprKind::AssignOp(_, left, right) => {
++ self.visit_exprs_for_binary_ops(left, right, true, ex.span);
++ }
++ ExprKind::Tup(exprs) => {
++ for expr in exprs {
++ self.visit_expr(expr);
++ if self.has_significant_drop {
++ // We may have not have set current_sig_drop if all the suggestions were
++ // MoveAndClone, so add this tuple item's full expression in that case.
++ if self.current_sig_drop.is_none() {
++ self.try_setting_current_suggestion(expr, true);
++ }
++
++ // Now we are guaranteed to have something, so add it to the final vec.
++ self.move_current_suggestion();
++ }
++ // Reset `has_significant_drop` after each tuple expression so we can look for
++ // additional cases.
++ self.has_significant_drop = false;
++ }
++ if self.sig_drop_spans.is_some() {
++ self.has_significant_drop = true;
++ }
++ }
++ ExprKind::Box(..) |
++ ExprKind::Array(..) |
++ ExprKind::Call(..) |
++ ExprKind::Unary(..) |
++ ExprKind::If(..) |
++ ExprKind::Match(..) |
++ ExprKind::Field(..) |
++ ExprKind::Index(..) |
++ ExprKind::Ret(..) |
++ ExprKind::Repeat(..) |
++ ExprKind::Yield(..) |
++ ExprKind::MethodCall(..) => walk_expr(self, ex),
++ ExprKind::AddrOf(_, _, _) |
++ ExprKind::Block(_, _) |
++ ExprKind::Break(_, _) |
++ ExprKind::Cast(_, _) |
++ // Don't want to check the closure itself, only invocation, which is covered by MethodCall
++ ExprKind::Closure(_, _, _, _, _) |
++ ExprKind::ConstBlock(_) |
++ ExprKind::Continue(_) |
++ ExprKind::DropTemps(_) |
++ ExprKind::Err |
++ ExprKind::InlineAsm(_) |
++ ExprKind::Let(_) |
++ ExprKind::Lit(_) |
++ ExprKind::Loop(_, _, _, _) |
++ ExprKind::Path(_) |
++ ExprKind::Struct(_, _, _) |
++ ExprKind::Type(_, _) => {
++ return;
++ }
++ }
++
++ // Once a significant temporary has been found, we need to go back up at least 1 level to
++ // find the span to extract for replacement, so the temporary gets dropped. However, for
++ // binary ops, we want to move the whole scrutinee so we avoid unnecessary copies and to
++ // simplify cases where both sides have significant drops.
++ if self.has_significant_drop && !self.special_handling_for_binary_op {
++ self.try_setting_current_suggestion(ex, false);
++ }
++ }
++}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint_and_sugg;
++use clippy_utils::source::snippet_with_applicability;
++use clippy_utils::ty::is_type_diagnostic_item;
++use clippy_utils::{get_parent_expr, is_lang_ctor, match_def_path, paths};
++use if_chain::if_chain;
++use rustc_errors::Applicability;
++use rustc_hir::LangItem::ResultErr;
++use rustc_hir::{Expr, ExprKind, LangItem, MatchSource, QPath};
++use rustc_lint::LateContext;
++use rustc_middle::ty::{self, Ty};
++use rustc_span::{hygiene, sym};
++
++use super::TRY_ERR;
++
++pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, scrutinee: &'tcx Expr<'_>) {
++ // Looks for a structure like this:
++ // match ::std::ops::Try::into_result(Err(5)) {
++ // ::std::result::Result::Err(err) =>
++ // #[allow(unreachable_code)]
++ // return ::std::ops::Try::from_error(::std::convert::From::from(err)),
++ // ::std::result::Result::Ok(val) =>
++ // #[allow(unreachable_code)]
++ // val,
++ // };
++ if_chain! {
++ if let ExprKind::Call(match_fun, try_args) = scrutinee.kind;
++ if let ExprKind::Path(ref match_fun_path) = match_fun.kind;
++ if matches!(match_fun_path, QPath::LangItem(LangItem::TryTraitBranch, ..));
++ if let Some(try_arg) = try_args.get(0);
++ if let ExprKind::Call(err_fun, err_args) = try_arg.kind;
++ if let Some(err_arg) = err_args.get(0);
++ if let ExprKind::Path(ref err_fun_path) = err_fun.kind;
++ if is_lang_ctor(cx, err_fun_path, ResultErr);
++ if let Some(return_ty) = find_return_type(cx, &expr.kind);
++ then {
++ let prefix;
++ let suffix;
++ let err_ty;
++
++ if let Some(ty) = result_error_type(cx, return_ty) {
++ prefix = "Err(";
++ suffix = ")";
++ err_ty = ty;
++ } else if let Some(ty) = poll_result_error_type(cx, return_ty) {
++ prefix = "Poll::Ready(Err(";
++ suffix = "))";
++ err_ty = ty;
++ } else if let Some(ty) = poll_option_result_error_type(cx, return_ty) {
++ prefix = "Poll::Ready(Some(Err(";
++ suffix = ")))";
++ err_ty = ty;
++ } else {
++ return;
++ };
++
++ let expr_err_ty = cx.typeck_results().expr_ty(err_arg);
++ let span = hygiene::walk_chain(err_arg.span, try_arg.span.ctxt());
++ let mut applicability = Applicability::MachineApplicable;
++ let origin_snippet = snippet_with_applicability(cx, span, "_", &mut applicability);
++ let ret_prefix = if get_parent_expr(cx, expr).map_or(false, |e| matches!(e.kind, ExprKind::Ret(_))) {
++ "" // already returns
++ } else {
++ "return "
++ };
++ let suggestion = if err_ty == expr_err_ty {
++ format!("{}{}{}{}", ret_prefix, prefix, origin_snippet, suffix)
++ } else {
++ format!("{}{}{}.into(){}", ret_prefix, prefix, origin_snippet, suffix)
++ };
++
++ span_lint_and_sugg(
++ cx,
++ TRY_ERR,
++ expr.span,
++ "returning an `Err(_)` with the `?` operator",
++ "try this",
++ suggestion,
++ applicability,
++ );
++ }
++ }
++}
++
++/// Finds function return type by examining return expressions in match arms.
++fn find_return_type<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx ExprKind<'_>) -> Option<Ty<'tcx>> {
++ if let ExprKind::Match(_, arms, MatchSource::TryDesugar) = expr {
++ for arm in arms.iter() {
++ if let ExprKind::Ret(Some(ret)) = arm.body.kind {
++ return Some(cx.typeck_results().expr_ty(ret));
++ }
++ }
++ }
++ None
++}
++
++/// Extracts the error type from Result<T, E>.
++fn result_error_type<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
++ if_chain! {
++ if let ty::Adt(_, subst) = ty.kind();
++ if is_type_diagnostic_item(cx, ty, sym::Result);
++ then {
++ Some(subst.type_at(1))
++ } else {
++ None
++ }
++ }
++}
++
++/// Extracts the error type from Poll<Result<T, E>>.
++fn poll_result_error_type<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
++ if_chain! {
++ if let ty::Adt(def, subst) = ty.kind();
++ if match_def_path(cx, def.did(), &paths::POLL);
++ let ready_ty = subst.type_at(0);
++
++ if let ty::Adt(ready_def, ready_subst) = ready_ty.kind();
++ if cx.tcx.is_diagnostic_item(sym::Result, ready_def.did());
++ then {
++ Some(ready_subst.type_at(1))
++ } else {
++ None
++ }
++ }
++}
++
++/// Extracts the error type from Poll<Option<Result<T, E>>>.
++fn poll_option_result_error_type<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
++ if_chain! {
++ if let ty::Adt(def, subst) = ty.kind();
++ if match_def_path(cx, def.did(), &paths::POLL);
++ let ready_ty = subst.type_at(0);
++
++ if let ty::Adt(ready_def, ready_subst) = ready_ty.kind();
++ if cx.tcx.is_diagnostic_item(sym::Option, ready_def.did());
++ let some_ty = ready_subst.type_at(0);
++
++ if let ty::Adt(some_def, some_subst) = some_ty.kind();
++ if cx.tcx.is_diagnostic_item(sym::Result, some_def.did());
++ then {
++ Some(some_subst.type_at(1))
++ } else {
++ None
++ }
++ }
++}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint_and_sugg;
++use clippy_utils::source::snippet_with_applicability;
++use clippy_utils::SpanlessEq;
++use rustc_ast::LitKind;
++use rustc_errors::Applicability;
++use rustc_hir::{BinOpKind, Expr, ExprKind};
++use rustc_lint::LateContext;
++use rustc_middle::ty;
++use rustc_span::source_map::Spanned;
++use rustc_span::sym;
++
++use super::GET_LAST_WITH_LEN;
++
++pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, arg: &Expr<'_>) {
++ // Argument to "get" is a subtraction
++ if let ExprKind::Binary(
++ Spanned {
++ node: BinOpKind::Sub, ..
++ },
++ lhs,
++ rhs,
++ ) = arg.kind
++
++ // LHS of subtraction is "x.len()"
++ && let ExprKind::MethodCall(lhs_path, [lhs_recv], _) = &lhs.kind
++ && lhs_path.ident.name == sym::len
++
++ // RHS of subtraction is 1
++ && let ExprKind::Lit(rhs_lit) = &rhs.kind
++ && let LitKind::Int(1, ..) = rhs_lit.node
++
++ // check that recv == lhs_recv `recv.get(lhs_recv.len() - 1)`
++ && SpanlessEq::new(cx).eq_expr(recv, lhs_recv)
++ && !recv.can_have_side_effects()
++ {
++ let method = match cx.typeck_results().expr_ty_adjusted(recv).peel_refs().kind() {
++ ty::Adt(def, _) if cx.tcx.is_diagnostic_item(sym::VecDeque, def.did()) => "back",
++ ty::Slice(_) => "last",
++ _ => return,
++ };
++
++ let mut applicability = Applicability::MachineApplicable;
++ let recv_snippet = snippet_with_applicability(cx, recv.span, "_", &mut applicability);
++
++ span_lint_and_sugg(
++ cx,
++ GET_LAST_WITH_LEN,
++ expr.span,
++ &format!("accessing last element with `{recv_snippet}.get({recv_snippet}.len() - 1)`"),
++ "try",
++ format!("{recv_snippet}.{method}()"),
++ applicability,
++ );
++ }
++}
--- /dev/null
- format!("{}.get({})", snippet_with_applicability(cx, caller_var.span, "..", &mut applicability), start_idx),
+use super::utils::derefs_to_slice;
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::{get_parent_expr, higher};
+use if_chain::if_chain;
+use rustc_ast::ast;
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_lint::LateContext;
+use rustc_middle::ty;
+use rustc_span::symbol::sym;
+
+use super::ITER_NEXT_SLICE;
+
+pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, caller_expr: &'tcx hir::Expr<'_>) {
+ // Skip lint if the `iter().next()` expression is a for loop argument,
+ // since it is already covered by `&loops::ITER_NEXT_LOOP`
+ let mut parent_expr_opt = get_parent_expr(cx, expr);
+ while let Some(parent_expr) = parent_expr_opt {
+ if higher::ForLoop::hir(parent_expr).is_some() {
+ return;
+ }
+ parent_expr_opt = get_parent_expr(cx, parent_expr);
+ }
+
+ if derefs_to_slice(cx, caller_expr, cx.typeck_results().expr_ty(caller_expr)).is_some() {
+ // caller is a Slice
+ if_chain! {
+ if let hir::ExprKind::Index(caller_var, index_expr) = &caller_expr.kind;
+ if let Some(higher::Range { start: Some(start_expr), end: None, limits: ast::RangeLimits::HalfOpen })
+ = higher::Range::hir(index_expr);
+ if let hir::ExprKind::Lit(ref start_lit) = &start_expr.kind;
+ if let ast::LitKind::Int(start_idx, _) = start_lit.node;
+ then {
+ let mut applicability = Applicability::MachineApplicable;
++ let suggest = if start_idx == 0 {
++ format!("{}.first()", snippet_with_applicability(cx, caller_var.span, "..", &mut applicability))
++ } else {
++ format!("{}.get({})", snippet_with_applicability(cx, caller_var.span, "..", &mut applicability), start_idx)
++ };
+ span_lint_and_sugg(
+ cx,
+ ITER_NEXT_SLICE,
+ expr.span,
+ "using `.iter().next()` on a Slice without end index",
+ "try calling",
- "{}.get(0)",
++ suggest,
+ applicability,
+ );
+ }
+ }
+ } else if is_vec_or_array(cx, caller_expr) {
+ // caller is a Vec or an Array
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ ITER_NEXT_SLICE,
+ expr.span,
+ "using `.iter().next()` on an array",
+ "try calling",
+ format!(
++ "{}.first()",
+ snippet_with_applicability(cx, caller_expr.span, "..", &mut applicability)
+ ),
+ applicability,
+ );
+ }
+}
+
+fn is_vec_or_array<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) -> bool {
+ is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::Vec)
+ || matches!(&cx.typeck_results().expr_ty(expr).peel_refs().kind(), ty::Array(_, _))
+}
--- /dev/null
- /// # let opt = Some(1);
- ///
- /// // Bad
- /// opt.unwrap();
- ///
- /// // Good
- /// opt.expect("more helpful message");
+mod bind_instead_of_map;
+mod bytes_nth;
+mod chars_cmp;
+mod chars_cmp_with_unwrap;
+mod chars_last_cmp;
+mod chars_last_cmp_with_unwrap;
+mod chars_next_cmp;
+mod chars_next_cmp_with_unwrap;
+mod clone_on_copy;
+mod clone_on_ref_ptr;
+mod cloned_instead_of_copied;
+mod err_expect;
+mod expect_fun_call;
+mod expect_used;
+mod extend_with_drain;
+mod filetype_is_file;
+mod filter_map;
+mod filter_map_identity;
+mod filter_map_next;
+mod filter_next;
+mod flat_map_identity;
+mod flat_map_option;
+mod from_iter_instead_of_collect;
++mod get_last_with_len;
+mod get_unwrap;
+mod implicit_clone;
+mod inefficient_to_string;
+mod inspect_for_each;
+mod into_iter_on_ref;
+mod is_digit_ascii_radix;
+mod iter_cloned_collect;
+mod iter_count;
+mod iter_next_slice;
+mod iter_nth;
+mod iter_nth_zero;
+mod iter_overeager_cloned;
+mod iter_skip_next;
+mod iter_with_drain;
+mod iterator_step_by_zero;
+mod manual_saturating_arithmetic;
+mod manual_str_repeat;
+mod map_collect_result_unit;
+mod map_flatten;
+mod map_identity;
+mod map_unwrap_or;
+mod needless_option_as_deref;
+mod needless_option_take;
++mod no_effect_replace;
+mod ok_expect;
+mod option_as_ref_deref;
+mod option_map_or_none;
+mod option_map_unwrap_or;
+mod or_fun_call;
+mod or_then_unwrap;
+mod search_is_some;
+mod single_char_add_str;
+mod single_char_insert_string;
+mod single_char_pattern;
+mod single_char_push_string;
+mod skip_while_next;
+mod str_splitn;
+mod string_extend_chars;
+mod suspicious_map;
+mod suspicious_splitn;
+mod uninit_assumed_init;
+mod unnecessary_filter_map;
+mod unnecessary_fold;
+mod unnecessary_iter_cloned;
+mod unnecessary_join;
+mod unnecessary_lazy_eval;
+mod unnecessary_to_owned;
+mod unwrap_or_else_default;
+mod unwrap_used;
+mod useless_asref;
+mod utils;
+mod wrong_self_convention;
+mod zst_offset;
+
+use bind_instead_of_map::BindInsteadOfMap;
+use clippy_utils::consts::{constant, Constant};
+use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
+use clippy_utils::ty::{contains_adt_constructor, contains_ty, implements_trait, is_copy, is_type_diagnostic_item};
+use clippy_utils::{contains_return, get_trait_def_id, iter_input_pats, meets_msrv, msrvs, paths, return_ty};
+use if_chain::if_chain;
+use rustc_hir as hir;
+use rustc_hir::def::Res;
+use rustc_hir::{Expr, ExprKind, PrimTy, QPath, TraitItem, TraitItemKind};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::{self, TraitRef, Ty};
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::{sym, Span};
+use rustc_typeck::hir_ty_to_ty;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usages of `cloned()` on an `Iterator` or `Option` where
+ /// `copied()` could be used instead.
+ ///
+ /// ### Why is this bad?
+ /// `copied()` is better because it guarantees that the type being cloned
+ /// implements `Copy`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// [1, 2, 3].iter().cloned();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// [1, 2, 3].iter().copied();
+ /// ```
+ #[clippy::version = "1.53.0"]
+ pub CLONED_INSTEAD_OF_COPIED,
+ pedantic,
+ "used `cloned` where `copied` could be used instead"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.cloned().<func>()` where call to `.cloned()` can be postponed.
+ ///
+ /// ### Why is this bad?
+ /// It's often inefficient to clone all elements of an iterator, when eventually, only some
+ /// of them will be consumed.
+ ///
+ /// ### Examples
+ /// ```rust
+ /// # let vec = vec!["string".to_string()];
+ ///
+ /// // Bad
+ /// vec.iter().cloned().take(10);
+ ///
+ /// // Good
+ /// vec.iter().take(10).cloned();
+ ///
+ /// // Bad
+ /// vec.iter().cloned().last();
+ ///
+ /// // Good
+ /// vec.iter().last().cloned();
+ ///
+ /// ```
+ /// ### Known Problems
+ /// This `lint` removes the side of effect of cloning items in the iterator.
+ /// A code that relies on that side-effect could fail.
+ ///
+ #[clippy::version = "1.59.0"]
+ pub ITER_OVEREAGER_CLONED,
+ perf,
+ "using `cloned()` early with `Iterator::iter()` can lead to some performance inefficiencies"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usages of `Iterator::flat_map()` where `filter_map()` could be
+ /// used instead.
+ ///
+ /// ### Why is this bad?
+ /// When applicable, `filter_map()` is more clear since it shows that
+ /// `Option` is used to produce 0 or 1 items.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let nums: Vec<i32> = ["1", "2", "whee!"].iter().flat_map(|x| x.parse().ok()).collect();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let nums: Vec<i32> = ["1", "2", "whee!"].iter().filter_map(|x| x.parse().ok()).collect();
+ /// ```
+ #[clippy::version = "1.53.0"]
+ pub FLAT_MAP_OPTION,
+ pedantic,
+ "used `flat_map` where `filter_map` could be used instead"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `.unwrap()` calls on `Option`s and on `Result`s.
+ ///
+ /// ### Why is this bad?
+ /// It is better to handle the `None` or `Err` case,
+ /// or at least call `.expect(_)` with a more helpful message. Still, for a lot of
+ /// quick-and-dirty code, `unwrap` is a good choice, which is why this lint is
+ /// `Allow` by default.
+ ///
+ /// `result.unwrap()` will let the thread panic on `Err` values.
+ /// Normally, you want to implement more sophisticated error handling,
+ /// and propagate errors upwards with `?` operator.
+ ///
+ /// Even if you want to panic on errors, not all `Error`s implement good
+ /// messages on display. Therefore, it may be beneficial to look at the places
+ /// where they may get displayed. Activate this lint to do just that.
+ ///
+ /// ### Examples
+ /// ```rust
- /// // or
- ///
++ /// # let option = Some(1);
++ /// # let result: Result<usize, ()> = Ok(1);
++ /// option.unwrap();
++ /// result.unwrap();
+ /// ```
+ ///
- /// # let res: Result<usize, ()> = Ok(1);
- ///
- /// // Bad
- /// res.unwrap();
- ///
- /// // Good
- /// res.expect("more helpful message");
++ /// Use instead:
+ /// ```rust
- /// # let opt = Some(1);
- ///
- /// // Bad
- /// opt.expect("one");
- ///
- /// // Good
- /// let opt = Some(1);
- /// opt?;
++ /// # let option = Some(1);
++ /// # let result: Result<usize, ()> = Ok(1);
++ /// option.expect("more helpful message");
++ /// result.expect("more helpful message");
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub UNWRAP_USED,
+ restriction,
+ "using `.unwrap()` on `Result` or `Option`, which should at least get a better message using `expect()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `.expect()` calls on `Option`s and `Result`s.
+ ///
+ /// ### Why is this bad?
+ /// Usually it is better to handle the `None` or `Err` case.
+ /// Still, for a lot of quick-and-dirty code, `expect` is a good choice, which is why
+ /// this lint is `Allow` by default.
+ ///
+ /// `result.expect()` will let the thread panic on `Err`
+ /// values. Normally, you want to implement more sophisticated error handling,
+ /// and propagate errors upwards with `?` operator.
+ ///
+ /// ### Examples
+ /// ```rust,ignore
- /// // or
- ///
- /// ```rust
- /// # let res: Result<usize, ()> = Ok(1);
++ /// # let option = Some(1);
++ /// # let result: Result<usize, ()> = Ok(1);
++ /// option.expect("one");
++ /// result.expect("one");
+ /// ```
+ ///
- /// // Bad
- /// res.expect("one");
++ /// Use instead:
++ /// ```rust,ignore
++ /// # let option = Some(1);
++ /// # let result: Result<usize, ()> = Ok(1);
++ /// option?;
+ ///
- /// // Good
- /// res?;
- /// # Ok::<(), ()>(())
++ /// // or
+ ///
- /// # let x = Some(1);
- ///
- /// // Bad
- /// x.map(|a| a + 1).unwrap_or(0);
- ///
- /// // Good
- /// x.map_or(0, |a| a + 1);
++ /// result?;
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub EXPECT_USED,
+ restriction,
+ "using `.expect()` on `Result` or `Option`, which might be better handled"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for methods that should live in a trait
+ /// implementation of a `std` trait (see [llogiq's blog
+ /// post](http://llogiq.github.io/2015/07/30/traits.html) for further
+ /// information) instead of an inherent implementation.
+ ///
+ /// ### Why is this bad?
+ /// Implementing the traits improve ergonomics for users of
+ /// the code, often with very little cost. Also people seeing a `mul(...)`
+ /// method
+ /// may expect `*` to work equally, so you should have good reason to disappoint
+ /// them.
+ ///
+ /// ### Example
+ /// ```rust
+ /// struct X;
+ /// impl X {
+ /// fn add(&self, other: &X) -> X {
+ /// // ..
+ /// # X
+ /// }
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub SHOULD_IMPLEMENT_TRAIT,
+ style,
+ "defining a method that should be implementing a std trait"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for methods with certain name prefixes and which
+ /// doesn't match how self is taken. The actual rules are:
+ ///
+ /// |Prefix |Postfix |`self` taken | `self` type |
+ /// |-------|------------|-------------------------------|--------------|
+ /// |`as_` | none |`&self` or `&mut self` | any |
+ /// |`from_`| none | none | any |
+ /// |`into_`| none |`self` | any |
+ /// |`is_` | none |`&mut self` or `&self` or none | any |
+ /// |`to_` | `_mut` |`&mut self` | any |
+ /// |`to_` | not `_mut` |`self` | `Copy` |
+ /// |`to_` | not `_mut` |`&self` | not `Copy` |
+ ///
+ /// Note: Clippy doesn't trigger methods with `to_` prefix in:
+ /// - Traits definition.
+ /// Clippy can not tell if a type that implements a trait is `Copy` or not.
+ /// - Traits implementation, when `&self` is taken.
+ /// The method signature is controlled by the trait and often `&self` is required for all types that implement the trait
+ /// (see e.g. the `std::string::ToString` trait).
+ ///
+ /// Clippy allows `Pin<&Self>` and `Pin<&mut Self>` if `&self` and `&mut self` is required.
+ ///
+ /// Please find more info here:
+ /// https://rust-lang.github.io/api-guidelines/naming.html#ad-hoc-conversions-follow-as_-to_-into_-conventions-c-conv
+ ///
+ /// ### Why is this bad?
+ /// Consistency breeds readability. If you follow the
+ /// conventions, your users won't be surprised that they, e.g., need to supply a
+ /// mutable reference to a `as_..` function.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # struct X;
+ /// impl X {
+ /// fn as_str(self) -> &'static str {
+ /// // ..
+ /// # ""
+ /// }
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub WRONG_SELF_CONVENTION,
+ style,
+ "defining a method named with an established prefix (like \"into_\") that takes `self` with the wrong convention"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `ok().expect(..)`.
+ ///
+ /// ### Why is this bad?
+ /// Because you usually call `expect()` on the `Result`
+ /// directly to get a better error message.
+ ///
+ /// ### Known problems
+ /// The error type needs to implement `Debug`
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let x = Ok::<_, ()>(());
+ ///
+ /// // Bad
+ /// x.ok().expect("why did I do this again?");
+ ///
+ /// // Good
+ /// x.expect("why did I do this again?");
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub OK_EXPECT,
+ style,
+ "using `ok().expect()`, which gives worse error messages than calling `expect` directly on the Result"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `.err().expect()` calls on the `Result` type.
+ ///
+ /// ### Why is this bad?
+ /// `.expect_err()` can be called directly to avoid the extra type conversion from `err()`.
+ ///
+ /// ### Example
+ /// ```should_panic
+ /// let x: Result<u32, &str> = Ok(10);
+ /// x.err().expect("Testing err().expect()");
+ /// ```
+ /// Use instead:
+ /// ```should_panic
+ /// let x: Result<u32, &str> = Ok(10);
+ /// x.expect_err("Testing expect_err");
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub ERR_EXPECT,
+ style,
+ r#"using `.err().expect("")` when `.expect_err("")` can be used"#
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usages of `_.unwrap_or_else(Default::default)` on `Option` and
+ /// `Result` values.
+ ///
+ /// ### Why is this bad?
+ /// Readability, these can be written as `_.unwrap_or_default`, which is
+ /// simpler and more concise.
+ ///
+ /// ### Examples
+ /// ```rust
+ /// # let x = Some(1);
+ ///
+ /// // Bad
+ /// x.unwrap_or_else(Default::default);
+ /// x.unwrap_or_else(u32::default);
+ ///
+ /// // Good
+ /// x.unwrap_or_default();
+ /// ```
+ #[clippy::version = "1.56.0"]
+ pub UNWRAP_OR_ELSE_DEFAULT,
+ style,
+ "using `.unwrap_or_else(Default::default)`, which is more succinctly expressed as `.unwrap_or_default()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `option.map(_).unwrap_or(_)` or `option.map(_).unwrap_or_else(_)` or
+ /// `result.map(_).unwrap_or_else(_)`.
+ ///
+ /// ### Why is this bad?
+ /// Readability, these can be written more concisely (resp.) as
+ /// `option.map_or(_, _)`, `option.map_or_else(_, _)` and `result.map_or_else(_, _)`.
+ ///
+ /// ### Known problems
+ /// The order of the arguments is not in execution order
+ ///
+ /// ### Examples
+ /// ```rust
- /// // or
- ///
++ /// # let option = Some(1);
++ /// # let result: Result<usize, ()> = Ok(1);
++ /// # fn some_function(foo: ()) -> usize { 1 }
++ /// option.map(|a| a + 1).unwrap_or(0);
++ /// result.map(|a| a + 1).unwrap_or_else(some_function);
+ /// ```
+ ///
- /// # let x: Result<usize, ()> = Ok(1);
++ /// Use instead:
+ /// ```rust
- ///
- /// // Bad
- /// x.map(|a| a + 1).unwrap_or_else(some_function);
- ///
- /// // Good
- /// x.map_or_else(some_function, |a| a + 1);
++ /// # let option = Some(1);
++ /// # let result: Result<usize, ()> = Ok(1);
+ /// # fn some_function(foo: ()) -> usize { 1 }
- /// this can instead be written:
++ /// option.map_or(0, |a| a + 1);
++ /// result.map_or_else(some_function, |a| a + 1);
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub MAP_UNWRAP_OR,
+ pedantic,
+ "using `.map(f).unwrap_or(a)` or `.map(f).unwrap_or_else(func)`, which are more succinctly expressed as `map_or(a, f)` or `map_or_else(a, f)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.map_or(None, _)`.
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
+ /// `_.and_then(_)`.
+ ///
+ /// ### Known problems
+ /// The order of the arguments is not in execution order.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let opt = Some(1);
+ ///
+ /// // Bad
+ /// opt.map_or(None, |a| Some(a + 1));
+ ///
+ /// // Good
+ /// opt.and_then(|a| Some(a + 1));
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub OPTION_MAP_OR_NONE,
+ style,
+ "using `Option.map_or(None, f)`, which is more succinctly expressed as `and_then(f)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.map_or(None, Some)`.
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
+ /// `_.ok()`.
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust
+ /// # let r: Result<u32, &str> = Ok(1);
+ /// assert_eq!(Some(1), r.map_or(None, Some));
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// # let r: Result<u32, &str> = Ok(1);
+ /// assert_eq!(Some(1), r.ok());
+ /// ```
+ #[clippy::version = "1.44.0"]
+ pub RESULT_MAP_OR_INTO_OPTION,
+ style,
+ "using `Result.map_or(None, Some)`, which is more succinctly expressed as `ok()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.and_then(|x| Some(y))`, `_.and_then(|x| Ok(y))` or
+ /// `_.or_else(|x| Err(y))`.
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
+ /// `_.map(|x| y)` or `_.map_err(|x| y)`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # fn opt() -> Option<&'static str> { Some("42") }
+ /// # fn res() -> Result<&'static str, &'static str> { Ok("42") }
+ /// let _ = opt().and_then(|s| Some(s.len()));
+ /// let _ = res().and_then(|s| if s.len() == 42 { Ok(10) } else { Ok(20) });
+ /// let _ = res().or_else(|s| if s.len() == 42 { Err(10) } else { Err(20) });
+ /// ```
+ ///
+ /// The correct use would be:
+ ///
+ /// ```rust
+ /// # fn opt() -> Option<&'static str> { Some("42") }
+ /// # fn res() -> Result<&'static str, &'static str> { Ok("42") }
+ /// let _ = opt().map(|s| s.len());
+ /// let _ = res().map(|s| if s.len() == 42 { 10 } else { 20 });
+ /// let _ = res().map_err(|s| if s.len() == 42 { 10 } else { 20 });
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub BIND_INSTEAD_OF_MAP,
+ complexity,
+ "using `Option.and_then(|x| Some(y))`, which is more succinctly expressed as `map(|x| y)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.filter(_).next()`.
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
+ /// `_.find(_)`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let vec = vec![1];
+ /// vec.iter().filter(|x| **x == 0).next();
+ /// ```
+ /// Could be written as
+ /// ```rust
+ /// # let vec = vec![1];
+ /// vec.iter().find(|x| **x == 0);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub FILTER_NEXT,
+ complexity,
+ "using `filter(p).next()`, which is more succinctly expressed as `.find(p)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.skip_while(condition).next()`.
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
+ /// `_.find(!condition)`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let vec = vec![1];
+ /// vec.iter().skip_while(|x| **x == 0).next();
+ /// ```
+ /// Could be written as
+ /// ```rust
+ /// # let vec = vec![1];
+ /// vec.iter().find(|x| **x != 0);
+ /// ```
+ #[clippy::version = "1.42.0"]
+ pub SKIP_WHILE_NEXT,
+ complexity,
+ "using `skip_while(p).next()`, which is more succinctly expressed as `.find(!p)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.map(_).flatten(_)` on `Iterator` and `Option`
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
+ /// `_.flat_map(_)` for `Iterator` or `_.and_then(_)` for `Option`
+ ///
+ /// ### Example
+ /// ```rust
+ /// let vec = vec![vec![1]];
+ /// let opt = Some(5);
+ ///
+ /// // Bad
+ /// vec.iter().map(|x| x.iter()).flatten();
+ /// opt.map(|x| Some(x * 2)).flatten();
+ ///
+ /// // Good
+ /// vec.iter().flat_map(|x| x.iter());
+ /// opt.and_then(|x| Some(x * 2));
+ /// ```
+ #[clippy::version = "1.31.0"]
+ pub MAP_FLATTEN,
+ complexity,
+ "using combinations of `flatten` and `map` which can usually be written as a single method call"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.filter(_).map(_)` that can be written more simply
+ /// as `filter_map(_)`.
+ ///
+ /// ### Why is this bad?
+ /// Redundant code in the `filter` and `map` operations is poor style and
+ /// less performant.
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust
+ /// (0_i32..10)
+ /// .filter(|n| n.checked_add(1).is_some())
+ /// .map(|n| n.checked_add(1).unwrap());
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// (0_i32..10).filter_map(|n| n.checked_add(1));
+ /// ```
+ #[clippy::version = "1.51.0"]
+ pub MANUAL_FILTER_MAP,
+ complexity,
+ "using `_.filter(_).map(_)` in a way that can be written more simply as `filter_map(_)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.find(_).map(_)` that can be written more simply
+ /// as `find_map(_)`.
+ ///
+ /// ### Why is this bad?
+ /// Redundant code in the `find` and `map` operations is poor style and
+ /// less performant.
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust
+ /// (0_i32..10)
+ /// .find(|n| n.checked_add(1).is_some())
+ /// .map(|n| n.checked_add(1).unwrap());
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// (0_i32..10).find_map(|n| n.checked_add(1));
+ /// ```
+ #[clippy::version = "1.51.0"]
+ pub MANUAL_FIND_MAP,
+ complexity,
+ "using `_.find(_).map(_)` in a way that can be written more simply as `find_map(_)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.filter_map(_).next()`.
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
+ /// `_.find_map(_)`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// (0..3).filter_map(|x| if x == 2 { Some(x) } else { None }).next();
+ /// ```
+ /// Can be written as
+ ///
+ /// ```rust
+ /// (0..3).find_map(|x| if x == 2 { Some(x) } else { None });
+ /// ```
+ #[clippy::version = "1.36.0"]
+ pub FILTER_MAP_NEXT,
+ pedantic,
+ "using combination of `filter_map` and `next` which can usually be written as a single method call"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `flat_map(|x| x)`.
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely by using `flatten`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let iter = vec![vec![0]].into_iter();
+ /// iter.flat_map(|x| x);
+ /// ```
+ /// Can be written as
+ /// ```rust
+ /// # let iter = vec![vec![0]].into_iter();
+ /// iter.flatten();
+ /// ```
+ #[clippy::version = "1.39.0"]
+ pub FLAT_MAP_IDENTITY,
+ complexity,
+ "call to `flat_map` where `flatten` is sufficient"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for an iterator or string search (such as `find()`,
+ /// `position()`, or `rposition()`) followed by a call to `is_some()` or `is_none()`.
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as:
+ /// * `_.any(_)`, or `_.contains(_)` for `is_some()`,
+ /// * `!_.any(_)`, or `!_.contains(_)` for `is_none()`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let vec = vec![1];
+ /// vec.iter().find(|x| **x == 0).is_some();
+ ///
+ /// let _ = "hello world".find("world").is_none();
+ /// ```
+ /// Could be written as
+ /// ```rust
+ /// let vec = vec![1];
+ /// vec.iter().any(|x| *x == 0);
+ ///
+ /// let _ = !"hello world".contains("world");
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub SEARCH_IS_SOME,
+ complexity,
+ "using an iterator or string search followed by `is_some()` or `is_none()`, which is more succinctly expressed as a call to `any()` or `contains()` (with negation in case of `is_none()`)"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `.chars().next()` on a `str` to check
+ /// if it starts with a given char.
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
+ /// `_.starts_with(_)`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let name = "foo";
+ /// if name.chars().next() == Some('_') {};
+ /// ```
+ /// Could be written as
+ /// ```rust
+ /// let name = "foo";
+ /// if name.starts_with('_') {};
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CHARS_NEXT_CMP,
+ style,
+ "using `.chars().next()` to check if a string starts with a char"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calls to `.or(foo(..))`, `.unwrap_or(foo(..))`,
+ /// etc., and suggests to use `or_else`, `unwrap_or_else`, etc., or
+ /// `unwrap_or_default` instead.
+ ///
+ /// ### Why is this bad?
+ /// The function will always be called and potentially
+ /// allocate an object acting as the default.
+ ///
+ /// ### Known problems
+ /// If the function has side-effects, not calling it will
+ /// change the semantic of the program, but you shouldn't rely on that anyway.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let foo = Some(String::new());
+ /// foo.unwrap_or(String::new());
+ /// ```
- /// ```
- /// or
- /// ```rust
++ ///
++ /// Use instead:
+ /// ```rust
+ /// # let foo = Some(String::new());
+ /// foo.unwrap_or_else(String::new);
- /// ```
- /// or
- /// ```rust
++ ///
++ /// // or
++ ///
+ /// # let foo = Some(String::new());
+ /// foo.unwrap_or_default();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub OR_FUN_CALL,
+ perf,
+ "using any `*or` method with a function call, which suggests `*or_else`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `.or(…).unwrap()` calls to Options and Results.
+ ///
+ /// ### Why is this bad?
+ /// You should use `.unwrap_or(…)` instead for clarity.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let fallback = "fallback";
+ /// // Result
+ /// # type Error = &'static str;
+ /// # let result: Result<&str, Error> = Err("error");
+ /// let value = result.or::<Error>(Ok(fallback)).unwrap();
+ ///
+ /// // Option
+ /// # let option: Option<&str> = None;
+ /// let value = option.or(Some(fallback)).unwrap();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// # let fallback = "fallback";
+ /// // Result
+ /// # let result: Result<&str, &str> = Err("error");
+ /// let value = result.unwrap_or(fallback);
+ ///
+ /// // Option
+ /// # let option: Option<&str> = None;
+ /// let value = option.unwrap_or(fallback);
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub OR_THEN_UNWRAP,
+ complexity,
+ "checks for `.or(…).unwrap()` calls to Options and Results."
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calls to `.expect(&format!(...))`, `.expect(foo(..))`,
+ /// etc., and suggests to use `unwrap_or_else` instead
+ ///
+ /// ### Why is this bad?
+ /// The function will always be called.
+ ///
+ /// ### Known problems
+ /// If the function has side-effects, not calling it will
+ /// change the semantics of the program, but you shouldn't rely on that anyway.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let foo = Some(String::new());
+ /// # let err_code = "418";
+ /// # let err_msg = "I'm a teapot";
+ /// foo.expect(&format!("Err {}: {}", err_code, err_msg));
- /// # let err_code = "418";
- /// # let err_msg = "I'm a teapot";
++ ///
++ /// // or
++ ///
+ /// # let foo = Some(String::new());
- /// this can instead be written:
+ /// foo.expect(format!("Err {}: {}", err_code, err_msg).as_str());
+ /// ```
++ ///
++ /// Use instead:
+ /// ```rust
+ /// # let foo = Some(String::new());
+ /// # let err_code = "418";
+ /// # let err_msg = "I'm a teapot";
+ /// foo.unwrap_or_else(|| panic!("Err {}: {}", err_code, err_msg));
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EXPECT_FUN_CALL,
+ perf,
+ "using any `expect` method with a function call"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `.clone()` on a `Copy` type.
+ ///
+ /// ### Why is this bad?
+ /// The only reason `Copy` types implement `Clone` is for
+ /// generics, not for using the `clone` method on a concrete type.
+ ///
+ /// ### Example
+ /// ```rust
+ /// 42u64.clone();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CLONE_ON_COPY,
+ complexity,
+ "using `clone` on a `Copy` type"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `.clone()` on a ref-counted pointer,
+ /// (`Rc`, `Arc`, `rc::Weak`, or `sync::Weak`), and suggests calling Clone via unified
+ /// function syntax instead (e.g., `Rc::clone(foo)`).
+ ///
+ /// ### Why is this bad?
+ /// Calling '.clone()' on an Rc, Arc, or Weak
+ /// can obscure the fact that only the pointer is being cloned, not the underlying
+ /// data.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::rc::Rc;
+ /// let x = Rc::new(1);
+ ///
+ /// // Bad
+ /// x.clone();
+ ///
+ /// // Good
+ /// Rc::clone(&x);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CLONE_ON_REF_PTR,
+ restriction,
+ "using 'clone' on a ref-counted pointer"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `.clone()` on an `&&T`.
+ ///
+ /// ### Why is this bad?
+ /// Cloning an `&&T` copies the inner `&T`, instead of
+ /// cloning the underlying `T`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn main() {
+ /// let x = vec![1];
+ /// let y = &&x;
+ /// let z = y.clone();
+ /// println!("{:p} {:p}", *y, z); // prints out the same pointer
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CLONE_DOUBLE_REF,
+ correctness,
+ "using `clone` on `&&T`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `.to_string()` on an `&&T` where
+ /// `T` implements `ToString` directly (like `&&str` or `&&String`).
+ ///
+ /// ### Why is this bad?
+ /// This bypasses the specialized implementation of
+ /// `ToString` and instead goes through the more expensive string formatting
+ /// facilities.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Generic implementation for `T: Display` is used (slow)
+ /// ["foo", "bar"].iter().map(|s| s.to_string());
+ ///
+ /// // OK, the specialized impl is used
+ /// ["foo", "bar"].iter().map(|&s| s.to_string());
+ /// ```
+ #[clippy::version = "1.40.0"]
+ pub INEFFICIENT_TO_STRING,
+ pedantic,
+ "using `to_string` on `&&T` where `T: ToString`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `new` not returning a type that contains `Self`.
+ ///
+ /// ### Why is this bad?
+ /// As a convention, `new` methods are used to make a new
+ /// instance of a type.
+ ///
+ /// ### Example
+ /// In an impl block:
+ /// ```rust
+ /// # struct Foo;
+ /// # struct NotAFoo;
+ /// impl Foo {
+ /// fn new() -> NotAFoo {
+ /// # NotAFoo
+ /// }
+ /// }
+ /// ```
+ ///
+ /// ```rust
+ /// # struct Foo;
+ /// struct Bar(Foo);
+ /// impl Foo {
+ /// // Bad. The type name must contain `Self`
+ /// fn new() -> Bar {
+ /// # Bar(Foo)
+ /// }
+ /// }
+ /// ```
+ ///
+ /// ```rust
+ /// # struct Foo;
+ /// # struct FooError;
+ /// impl Foo {
+ /// // Good. Return type contains `Self`
+ /// fn new() -> Result<Foo, FooError> {
+ /// # Ok(Foo)
+ /// }
+ /// }
+ /// ```
+ ///
+ /// Or in a trait definition:
+ /// ```rust
+ /// pub trait Trait {
+ /// // Bad. The type name must contain `Self`
+ /// fn new();
+ /// }
+ /// ```
+ ///
+ /// ```rust
+ /// pub trait Trait {
+ /// // Good. Return type contains `Self`
+ /// fn new() -> Self;
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NEW_RET_NO_SELF,
+ style,
+ "not returning type containing `Self` in a `new` method"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for string methods that receive a single-character
+ /// `str` as an argument, e.g., `_.split("x")`.
+ ///
+ /// ### Why is this bad?
+ /// Performing these methods using a `char` is faster than
+ /// using a `str`.
+ ///
+ /// ### Known problems
+ /// Does not catch multi-byte unicode characters.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// // Bad
+ /// _.split("x");
+ ///
+ /// // Good
+ /// _.split('x');
+ #[clippy::version = "pre 1.29.0"]
+ pub SINGLE_CHAR_PATTERN,
+ perf,
+ "using a single-character str where a char could be used, e.g., `_.split(\"x\")`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calling `.step_by(0)` on iterators which panics.
+ ///
+ /// ### Why is this bad?
+ /// This very much looks like an oversight. Use `panic!()` instead if you
+ /// actually intend to panic.
+ ///
+ /// ### Example
+ /// ```rust,should_panic
+ /// for x in (0..100).step_by(0) {
+ /// //..
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ITERATOR_STEP_BY_ZERO,
+ correctness,
+ "using `Iterator::step_by(0)`, which will panic at runtime"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for indirect collection of populated `Option`
+ ///
+ /// ### Why is this bad?
+ /// `Option` is like a collection of 0-1 things, so `flatten`
+ /// automatically does this without suspicious-looking `unwrap` calls.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let _ = std::iter::empty::<Option<i32>>().filter(Option::is_some).map(Option::unwrap);
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let _ = std::iter::empty::<Option<i32>>().flatten();
+ /// ```
+ #[clippy::version = "1.53.0"]
+ pub OPTION_FILTER_MAP,
+ complexity,
+ "filtering `Option` for `Some` then force-unwrapping, which can be one type-safe operation"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the use of `iter.nth(0)`.
+ ///
+ /// ### Why is this bad?
+ /// `iter.next()` is equivalent to
+ /// `iter.nth(0)`, as they both consume the next element,
+ /// but is more readable.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::collections::HashSet;
+ /// // Bad
+ /// # let mut s = HashSet::new();
+ /// # s.insert(1);
+ /// let x = s.iter().nth(0);
+ ///
+ /// // Good
+ /// # let mut s = HashSet::new();
+ /// # s.insert(1);
+ /// let x = s.iter().next();
+ /// ```
+ #[clippy::version = "1.42.0"]
+ pub ITER_NTH_ZERO,
+ style,
+ "replace `iter.nth(0)` with `iter.next()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for use of `.iter().nth()` (and the related
+ /// `.iter_mut().nth()`) on standard library types with *O*(1) element access.
+ ///
+ /// ### Why is this bad?
+ /// `.get()` and `.get_mut()` are more efficient and more
+ /// readable.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let some_vec = vec![0, 1, 2, 3];
+ /// let bad_vec = some_vec.iter().nth(3);
+ /// let bad_slice = &some_vec[..].iter().nth(3);
+ /// ```
+ /// The correct use would be:
+ /// ```rust
+ /// let some_vec = vec![0, 1, 2, 3];
+ /// let bad_vec = some_vec.get(3);
+ /// let bad_slice = &some_vec[..].get(3);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ITER_NTH,
+ perf,
+ "using `.iter().nth()` on a standard library type with O(1) element access"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for use of `.skip(x).next()` on iterators.
+ ///
+ /// ### Why is this bad?
+ /// `.nth(x)` is cleaner
+ ///
+ /// ### Example
+ /// ```rust
+ /// let some_vec = vec![0, 1, 2, 3];
+ /// let bad_vec = some_vec.iter().skip(3).next();
+ /// let bad_slice = &some_vec[..].iter().skip(3).next();
+ /// ```
+ /// The correct use would be:
+ /// ```rust
+ /// let some_vec = vec![0, 1, 2, 3];
+ /// let bad_vec = some_vec.iter().nth(3);
+ /// let bad_slice = &some_vec[..].iter().nth(3);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ITER_SKIP_NEXT,
+ style,
+ "using `.skip(x).next()` on an iterator"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for use of `.drain(..)` on `Vec` and `VecDeque` for iteration.
+ ///
+ /// ### Why is this bad?
+ /// `.into_iter()` is simpler with better performance.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::collections::HashSet;
+ /// let mut foo = vec![0, 1, 2, 3];
+ /// let bar: HashSet<usize> = foo.drain(..).collect();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// # use std::collections::HashSet;
+ /// let foo = vec![0, 1, 2, 3];
+ /// let bar: HashSet<usize> = foo.into_iter().collect();
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub ITER_WITH_DRAIN,
+ nursery,
+ "replace `.drain(..)` with `.into_iter()`"
+}
+
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for using `x.get(x.len() - 1)` instead of
++ /// `x.last()`.
++ ///
++ /// ### Why is this bad?
++ /// Using `x.last()` is easier to read and has the same
++ /// result.
++ ///
++ /// Note that using `x[x.len() - 1]` is semantically different from
++ /// `x.last()`. Indexing into the array will panic on out-of-bounds
++ /// accesses, while `x.get()` and `x.last()` will return `None`.
++ ///
++ /// There is another lint (get_unwrap) that covers the case of using
++ /// `x.get(index).unwrap()` instead of `x[index]`.
++ ///
++ /// ### Example
++ /// ```rust
++ /// // Bad
++ /// let x = vec![2, 3, 5];
++ /// let last_element = x.get(x.len() - 1);
++ ///
++ /// // Good
++ /// let x = vec![2, 3, 5];
++ /// let last_element = x.last();
++ /// ```
++ #[clippy::version = "1.37.0"]
++ pub GET_LAST_WITH_LEN,
++ complexity,
++ "Using `x.get(x.len() - 1)` when `x.last()` is correct and simpler"
++}
++
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for use of `.get().unwrap()` (or
+ /// `.get_mut().unwrap`) on a standard library type which implements `Index`
+ ///
+ /// ### Why is this bad?
+ /// Using the Index trait (`[]`) is more clear and more
+ /// concise.
+ ///
+ /// ### Known problems
+ /// Not a replacement for error handling: Using either
+ /// `.unwrap()` or the Index trait (`[]`) carries the risk of causing a `panic`
+ /// if the value being accessed is `None`. If the use of `.get().unwrap()` is a
+ /// temporary placeholder for dealing with the `Option` type, then this does
+ /// not mitigate the need for error handling. If there is a chance that `.get()`
+ /// will be `None` in your program, then it is advisable that the `None` case
+ /// is handled in a future refactor instead of using `.unwrap()` or the Index
+ /// trait.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let mut some_vec = vec![0, 1, 2, 3];
+ /// let last = some_vec.get(3).unwrap();
+ /// *some_vec.get_mut(0).unwrap() = 1;
+ /// ```
+ /// The correct use would be:
+ /// ```rust
+ /// let mut some_vec = vec![0, 1, 2, 3];
+ /// let last = some_vec[3];
+ /// some_vec[0] = 1;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub GET_UNWRAP,
+ restriction,
+ "using `.get().unwrap()` or `.get_mut().unwrap()` when using `[]` would work instead"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for occurrences where one vector gets extended instead of append
+ ///
+ /// ### Why is this bad?
+ /// Using `append` instead of `extend` is more concise and faster
+ ///
+ /// ### Example
+ /// ```rust
+ /// let mut a = vec![1, 2, 3];
+ /// let mut b = vec![4, 5, 6];
+ ///
+ /// // Bad
+ /// a.extend(b.drain(..));
+ ///
+ /// // Good
+ /// a.append(&mut b);
+ /// ```
+ #[clippy::version = "1.55.0"]
+ pub EXTEND_WITH_DRAIN,
+ perf,
+ "using vec.append(&mut vec) to move the full range of a vector to another"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the use of `.extend(s.chars())` where s is a
+ /// `&str` or `String`.
+ ///
+ /// ### Why is this bad?
+ /// `.push_str(s)` is clearer
+ ///
+ /// ### Example
+ /// ```rust
+ /// let abc = "abc";
+ /// let def = String::from("def");
+ /// let mut s = String::new();
+ /// s.extend(abc.chars());
+ /// s.extend(def.chars());
+ /// ```
+ /// The correct use would be:
+ /// ```rust
+ /// let abc = "abc";
+ /// let def = String::from("def");
+ /// let mut s = String::new();
+ /// s.push_str(abc);
+ /// s.push_str(&def);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub STRING_EXTEND_CHARS,
+ style,
+ "using `x.extend(s.chars())` where s is a `&str` or `String`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the use of `.cloned().collect()` on slice to
+ /// create a `Vec`.
+ ///
+ /// ### Why is this bad?
+ /// `.to_vec()` is clearer
+ ///
+ /// ### Example
+ /// ```rust
+ /// let s = [1, 2, 3, 4, 5];
+ /// let s2: Vec<isize> = s[..].iter().cloned().collect();
+ /// ```
+ /// The better use would be:
+ /// ```rust
+ /// let s = [1, 2, 3, 4, 5];
+ /// let s2: Vec<isize> = s.to_vec();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ITER_CLONED_COLLECT,
+ style,
+ "using `.cloned().collect()` on slice to create a `Vec`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.chars().last()` or
+ /// `_.chars().next_back()` on a `str` to check if it ends with a given char.
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
+ /// `_.ends_with(_)`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let name = "_";
+ ///
+ /// // Bad
+ /// name.chars().last() == Some('_') || name.chars().next_back() == Some('-');
+ ///
+ /// // Good
+ /// name.ends_with('_') || name.ends_with('-');
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CHARS_LAST_CMP,
+ style,
+ "using `.chars().last()` or `.chars().next_back()` to check if a string ends with a char"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `.as_ref()` or `.as_mut()` where the
+ /// types before and after the call are the same.
+ ///
+ /// ### Why is this bad?
+ /// The call is unnecessary.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # fn do_stuff(x: &[i32]) {}
+ /// let x: &[i32] = &[1, 2, 3, 4, 5];
+ /// do_stuff(x.as_ref());
+ /// ```
+ /// The correct use would be:
+ /// ```rust
+ /// # fn do_stuff(x: &[i32]) {}
+ /// let x: &[i32] = &[1, 2, 3, 4, 5];
+ /// do_stuff(x);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub USELESS_ASREF,
+ complexity,
+ "using `as_ref` where the types before and after the call are the same"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for using `fold` when a more succinct alternative exists.
+ /// Specifically, this checks for `fold`s which could be replaced by `any`, `all`,
+ /// `sum` or `product`.
+ ///
+ /// ### Why is this bad?
+ /// Readability.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let _ = (0..3).fold(false, |acc, x| acc || x > 2);
+ /// ```
+ /// This could be written as:
+ /// ```rust
+ /// let _ = (0..3).any(|x| x > 2);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub UNNECESSARY_FOLD,
+ style,
+ "using `fold` when a more succinct alternative exists"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `filter_map` calls that could be replaced by `filter` or `map`.
+ /// More specifically it checks if the closure provided is only performing one of the
+ /// filter or map operations and suggests the appropriate option.
+ ///
+ /// ### Why is this bad?
+ /// Complexity. The intent is also clearer if only a single
+ /// operation is being performed.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let _ = (0..3).filter_map(|x| if x > 2 { Some(x) } else { None });
+ ///
+ /// // As there is no transformation of the argument this could be written as:
+ /// let _ = (0..3).filter(|&x| x > 2);
+ /// ```
+ ///
+ /// ```rust
+ /// let _ = (0..4).filter_map(|x| Some(x + 1));
+ ///
+ /// // As there is no conditional check on the argument this could be written as:
+ /// let _ = (0..4).map(|x| x + 1);
+ /// ```
+ #[clippy::version = "1.31.0"]
+ pub UNNECESSARY_FILTER_MAP,
+ complexity,
+ "using `filter_map` when a more succinct alternative exists"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `find_map` calls that could be replaced by `find` or `map`. More
+ /// specifically it checks if the closure provided is only performing one of the
+ /// find or map operations and suggests the appropriate option.
+ ///
+ /// ### Why is this bad?
+ /// Complexity. The intent is also clearer if only a single
+ /// operation is being performed.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let _ = (0..3).find_map(|x| if x > 2 { Some(x) } else { None });
+ ///
+ /// // As there is no transformation of the argument this could be written as:
+ /// let _ = (0..3).find(|&x| x > 2);
+ /// ```
+ ///
+ /// ```rust
+ /// let _ = (0..4).find_map(|x| Some(x + 1));
+ ///
+ /// // As there is no conditional check on the argument this could be written as:
+ /// let _ = (0..4).map(|x| x + 1).next();
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub UNNECESSARY_FIND_MAP,
+ complexity,
+ "using `find_map` when a more succinct alternative exists"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `into_iter` calls on references which should be replaced by `iter`
+ /// or `iter_mut`.
+ ///
+ /// ### Why is this bad?
+ /// Readability. Calling `into_iter` on a reference will not move out its
+ /// content into the resulting iterator, which is confusing. It is better just call `iter` or
+ /// `iter_mut` directly.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// let _ = (&vec![3, 4, 5]).into_iter();
+ ///
+ /// // Good
+ /// let _ = (&vec![3, 4, 5]).iter();
+ /// ```
+ #[clippy::version = "1.32.0"]
+ pub INTO_ITER_ON_REF,
+ style,
+ "using `.into_iter()` on a reference"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calls to `map` followed by a `count`.
+ ///
+ /// ### Why is this bad?
+ /// It looks suspicious. Maybe `map` was confused with `filter`.
+ /// If the `map` call is intentional, this should be rewritten
+ /// using `inspect`. Or, if you intend to drive the iterator to
+ /// completion, you can just use `for_each` instead.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let _ = (0..3).map(|x| x + 2).count();
+ /// ```
+ #[clippy::version = "1.39.0"]
+ pub SUSPICIOUS_MAP,
+ suspicious,
+ "suspicious usage of map"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `MaybeUninit::uninit().assume_init()`.
+ ///
+ /// ### Why is this bad?
+ /// For most types, this is undefined behavior.
+ ///
+ /// ### Known problems
+ /// For now, we accept empty tuples and tuples / arrays
+ /// of `MaybeUninit`. There may be other types that allow uninitialized
+ /// data, but those are not yet rigorously defined.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Beware the UB
+ /// use std::mem::MaybeUninit;
+ ///
+ /// let _: usize = unsafe { MaybeUninit::uninit().assume_init() };
+ /// ```
+ ///
+ /// Note that the following is OK:
+ ///
+ /// ```rust
+ /// use std::mem::MaybeUninit;
+ ///
+ /// let _: [MaybeUninit<bool>; 5] = unsafe {
+ /// MaybeUninit::uninit().assume_init()
+ /// };
+ /// ```
+ #[clippy::version = "1.39.0"]
+ pub UNINIT_ASSUMED_INIT,
+ correctness,
+ "`MaybeUninit::uninit().assume_init()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `.checked_add/sub(x).unwrap_or(MAX/MIN)`.
+ ///
+ /// ### Why is this bad?
+ /// These can be written simply with `saturating_add/sub` methods.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let y: u32 = 0;
+ /// # let x: u32 = 100;
+ /// let add = x.checked_add(y).unwrap_or(u32::MAX);
+ /// let sub = x.checked_sub(y).unwrap_or(u32::MIN);
+ /// ```
+ ///
+ /// can be written using dedicated methods for saturating addition/subtraction as:
+ ///
+ /// ```rust
+ /// # let y: u32 = 0;
+ /// # let x: u32 = 100;
+ /// let add = x.saturating_add(y);
+ /// let sub = x.saturating_sub(y);
+ /// ```
+ #[clippy::version = "1.39.0"]
+ pub MANUAL_SATURATING_ARITHMETIC,
+ style,
+ "`.checked_add/sub(x).unwrap_or(MAX/MIN)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `offset(_)`, `wrapping_`{`add`, `sub`}, etc. on raw pointers to
+ /// zero-sized types
+ ///
+ /// ### Why is this bad?
+ /// This is a no-op, and likely unintended
+ ///
+ /// ### Example
+ /// ```rust
+ /// unsafe { (&() as *const ()).offset(1) };
+ /// ```
+ #[clippy::version = "1.41.0"]
+ pub ZST_OFFSET,
+ correctness,
+ "Check for offset calculations on raw pointers to zero-sized types"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `FileType::is_file()`.
+ ///
+ /// ### Why is this bad?
+ /// When people testing a file type with `FileType::is_file`
+ /// they are testing whether a path is something they can get bytes from. But
+ /// `is_file` doesn't cover special file types in unix-like systems, and doesn't cover
+ /// symlink in windows. Using `!FileType::is_dir()` is a better way to that intention.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # || {
+ /// let metadata = std::fs::metadata("foo.txt")?;
+ /// let filetype = metadata.file_type();
+ ///
+ /// if filetype.is_file() {
+ /// // read file
+ /// }
+ /// # Ok::<_, std::io::Error>(())
+ /// # };
+ /// ```
+ ///
+ /// should be written as:
+ ///
+ /// ```rust
+ /// # || {
+ /// let metadata = std::fs::metadata("foo.txt")?;
+ /// let filetype = metadata.file_type();
+ ///
+ /// if !filetype.is_dir() {
+ /// // read file
+ /// }
+ /// # Ok::<_, std::io::Error>(())
+ /// # };
+ /// ```
+ #[clippy::version = "1.42.0"]
+ pub FILETYPE_IS_FILE,
+ restriction,
+ "`FileType::is_file` is not recommended to test for readable file type"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.as_ref().map(Deref::deref)` or it's aliases (such as String::as_str).
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
+ /// `_.as_deref()`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let opt = Some("".to_string());
+ /// opt.as_ref().map(String::as_str)
+ /// # ;
+ /// ```
+ /// Can be written as
+ /// ```rust
+ /// # let opt = Some("".to_string());
+ /// opt.as_deref()
+ /// # ;
+ /// ```
+ #[clippy::version = "1.42.0"]
+ pub OPTION_AS_REF_DEREF,
+ complexity,
+ "using `as_ref().map(Deref::deref)`, which is more succinctly expressed as `as_deref()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `iter().next()` on a Slice or an Array
+ ///
+ /// ### Why is this bad?
+ /// These can be shortened into `.get()`
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let a = [1, 2, 3];
+ /// # let b = vec![1, 2, 3];
+ /// a[2..].iter().next();
+ /// b.iter().next();
+ /// ```
+ /// should be written as:
+ /// ```rust
+ /// # let a = [1, 2, 3];
+ /// # let b = vec![1, 2, 3];
+ /// a.get(2);
+ /// b.get(0);
+ /// ```
+ #[clippy::version = "1.46.0"]
+ pub ITER_NEXT_SLICE,
+ style,
+ "using `.iter().next()` on a sliced array, which can be shortened to just `.get()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns when using `push_str`/`insert_str` with a single-character string literal
+ /// where `push`/`insert` with a `char` would work fine.
+ ///
+ /// ### Why is this bad?
+ /// It's less clear that we are pushing a single character.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let mut string = String::new();
+ /// string.insert_str(0, "R");
+ /// string.push_str("R");
+ /// ```
+ /// Could be written as
+ /// ```rust
+ /// let mut string = String::new();
+ /// string.insert(0, 'R');
+ /// string.push('R');
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub SINGLE_CHAR_ADD_STR,
+ style,
+ "`push_str()` or `insert_str()` used with a single-character string literal as parameter"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// As the counterpart to `or_fun_call`, this lint looks for unnecessary
+ /// lazily evaluated closures on `Option` and `Result`.
+ ///
+ /// This lint suggests changing the following functions, when eager evaluation results in
+ /// simpler code:
+ /// - `unwrap_or_else` to `unwrap_or`
+ /// - `and_then` to `and`
+ /// - `or_else` to `or`
+ /// - `get_or_insert_with` to `get_or_insert`
+ /// - `ok_or_else` to `ok_or`
+ ///
+ /// ### Why is this bad?
+ /// Using eager evaluation is shorter and simpler in some cases.
+ ///
+ /// ### Known problems
+ /// It is possible, but not recommended for `Deref` and `Index` to have
+ /// side effects. Eagerly evaluating them can change the semantics of the program.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // example code where clippy issues a warning
+ /// let opt: Option<u32> = None;
+ ///
+ /// opt.unwrap_or_else(|| 42);
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let opt: Option<u32> = None;
+ ///
+ /// opt.unwrap_or(42);
+ /// ```
+ #[clippy::version = "1.48.0"]
+ pub UNNECESSARY_LAZY_EVALUATIONS,
+ style,
+ "using unnecessary lazy evaluation, which can be replaced with simpler eager evaluation"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.map(_).collect::<Result<(), _>()`.
+ ///
+ /// ### Why is this bad?
+ /// Using `try_for_each` instead is more readable and idiomatic.
+ ///
+ /// ### Example
+ /// ```rust
+ /// (0..3).map(|t| Err(t)).collect::<Result<(), _>>();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// (0..3).try_for_each(|t| Err(t));
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub MAP_COLLECT_RESULT_UNIT,
+ style,
+ "using `.map(_).collect::<Result<(),_>()`, which can be replaced with `try_for_each`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `from_iter()` function calls on types that implement the `FromIterator`
+ /// trait.
+ ///
+ /// ### Why is this bad?
+ /// It is recommended style to use collect. See
+ /// [FromIterator documentation](https://doc.rust-lang.org/std/iter/trait.FromIterator.html)
+ ///
+ /// ### Example
+ /// ```rust
+ /// let five_fives = std::iter::repeat(5).take(5);
+ ///
+ /// let v = Vec::from_iter(five_fives);
+ ///
+ /// assert_eq!(v, vec![5, 5, 5, 5, 5]);
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let five_fives = std::iter::repeat(5).take(5);
+ ///
+ /// let v: Vec<i32> = five_fives.collect();
+ ///
+ /// assert_eq!(v, vec![5, 5, 5, 5, 5]);
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub FROM_ITER_INSTEAD_OF_COLLECT,
+ pedantic,
+ "use `.collect()` instead of `::from_iter()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `inspect().for_each()`.
+ ///
+ /// ### Why is this bad?
+ /// It is the same as performing the computation
+ /// inside `inspect` at the beginning of the closure in `for_each`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// [1,2,3,4,5].iter()
+ /// .inspect(|&x| println!("inspect the number: {}", x))
+ /// .for_each(|&x| {
+ /// assert!(x >= 0);
+ /// });
+ /// ```
+ /// Can be written as
+ /// ```rust
+ /// [1,2,3,4,5].iter()
+ /// .for_each(|&x| {
+ /// println!("inspect the number: {}", x);
+ /// assert!(x >= 0);
+ /// });
+ /// ```
+ #[clippy::version = "1.51.0"]
+ pub INSPECT_FOR_EACH,
+ complexity,
+ "using `.inspect().for_each()`, which can be replaced with `.for_each()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `filter_map(|x| x)`.
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely by using `flatten`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let iter = vec![Some(1)].into_iter();
+ /// iter.filter_map(|x| x);
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// # let iter = vec![Some(1)].into_iter();
+ /// iter.flatten();
+ /// ```
+ #[clippy::version = "1.52.0"]
+ pub FILTER_MAP_IDENTITY,
+ complexity,
+ "call to `filter_map` where `flatten` is sufficient"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for instances of `map(f)` where `f` is the identity function.
+ ///
+ /// ### Why is this bad?
+ /// It can be written more concisely without the call to `map`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = [1, 2, 3];
+ /// let y: Vec<_> = x.iter().map(|x| x).map(|x| 2*x).collect();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let x = [1, 2, 3];
+ /// let y: Vec<_> = x.iter().map(|x| 2*x).collect();
+ /// ```
+ #[clippy::version = "1.52.0"]
+ pub MAP_IDENTITY,
+ complexity,
+ "using iterator.map(|x| x)"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the use of `.bytes().nth()`.
+ ///
+ /// ### Why is this bad?
+ /// `.as_bytes().get()` is more efficient and more
+ /// readable.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// let _ = "Hello".bytes().nth(3);
+ ///
+ /// // Good
+ /// let _ = "Hello".as_bytes().get(3);
+ /// ```
+ #[clippy::version = "1.52.0"]
+ pub BYTES_NTH,
+ style,
+ "replace `.bytes().nth()` with `.as_bytes().get()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the usage of `_.to_owned()`, `vec.to_vec()`, or similar when calling `_.clone()` would be clearer.
+ ///
+ /// ### Why is this bad?
+ /// These methods do the same thing as `_.clone()` but may be confusing as
+ /// to why we are calling `to_vec` on something that is already a `Vec` or calling `to_owned` on something that is already owned.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let a = vec![1, 2, 3];
+ /// let b = a.to_vec();
+ /// let c = a.to_owned();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let a = vec![1, 2, 3];
+ /// let b = a.clone();
+ /// let c = a.clone();
+ /// ```
+ #[clippy::version = "1.52.0"]
+ pub IMPLICIT_CLONE,
+ pedantic,
+ "implicitly cloning a value by invoking a function on its dereferenced type"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the use of `.iter().count()`.
+ ///
+ /// ### Why is this bad?
+ /// `.len()` is more efficient and more
+ /// readable.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// let some_vec = vec![0, 1, 2, 3];
+ /// let _ = some_vec.iter().count();
+ /// let _ = &some_vec[..].iter().count();
+ ///
+ /// // Good
+ /// let some_vec = vec![0, 1, 2, 3];
+ /// let _ = some_vec.len();
+ /// let _ = &some_vec[..].len();
+ /// ```
+ #[clippy::version = "1.52.0"]
+ pub ITER_COUNT,
+ complexity,
+ "replace `.iter().count()` with `.len()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calls to [`splitn`]
+ /// (https://doc.rust-lang.org/std/primitive.str.html#method.splitn) and
+ /// related functions with either zero or one splits.
+ ///
+ /// ### Why is this bad?
+ /// These calls don't actually split the value and are
+ /// likely to be intended as a different number.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// let s = "";
+ /// for x in s.splitn(1, ":") {
+ /// // use x
+ /// }
+ ///
+ /// // Good
+ /// let s = "";
+ /// for x in s.splitn(2, ":") {
+ /// // use x
+ /// }
+ /// ```
+ #[clippy::version = "1.54.0"]
+ pub SUSPICIOUS_SPLITN,
+ correctness,
+ "checks for `.splitn(0, ..)` and `.splitn(1, ..)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for manual implementations of `str::repeat`
+ ///
+ /// ### Why is this bad?
+ /// These are both harder to read, as well as less performant.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// let x: String = std::iter::repeat('x').take(10).collect();
+ ///
+ /// // Good
+ /// let x: String = "x".repeat(10);
+ /// ```
+ #[clippy::version = "1.54.0"]
+ pub MANUAL_STR_REPEAT,
+ perf,
+ "manual implementation of `str::repeat`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usages of `str::splitn(2, _)`
+ ///
+ /// ### Why is this bad?
+ /// `split_once` is both clearer in intent and slightly more efficient.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// // Bad
+ /// let s = "key=value=add";
+ /// let (key, value) = s.splitn(2, '=').next_tuple()?;
+ /// let value = s.splitn(2, '=').nth(1)?;
+ ///
+ /// let mut parts = s.splitn(2, '=');
+ /// let key = parts.next()?;
+ /// let value = parts.next()?;
+ /// ```
+ /// Use instead:
+ /// ```rust,ignore
+ /// // Good
+ /// let s = "key=value=add";
+ /// let (key, value) = s.split_once('=')?;
+ /// let value = s.split_once('=')?.1;
+ ///
+ /// let (key, value) = s.split_once('=')?;
+ /// ```
+ ///
+ /// ### Limitations
+ /// The multiple statement variant currently only detects `iter.next()?`/`iter.next().unwrap()`
+ /// in two separate `let` statements that immediately follow the `splitn()`
+ #[clippy::version = "1.57.0"]
+ pub MANUAL_SPLIT_ONCE,
+ complexity,
+ "replace `.splitn(2, pat)` with `.split_once(pat)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usages of `str::splitn` (or `str::rsplitn`) where using `str::split` would be the same.
+ /// ### Why is this bad?
+ /// The function `split` is simpler and there is no performance difference in these cases, considering
+ /// that both functions return a lazy iterator.
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// let str = "key=value=add";
+ /// let _ = str.splitn(3, '=').next().unwrap();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// // Good
+ /// let str = "key=value=add";
+ /// let _ = str.split('=').next().unwrap();
+ /// ```
+ #[clippy::version = "1.58.0"]
+ pub NEEDLESS_SPLITN,
+ complexity,
+ "usages of `str::splitn` that can be replaced with `str::split`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for unnecessary calls to [`ToOwned::to_owned`](https://doc.rust-lang.org/std/borrow/trait.ToOwned.html#tymethod.to_owned)
+ /// and other `to_owned`-like functions.
+ ///
+ /// ### Why is this bad?
+ /// The unnecessary calls result in useless allocations.
+ ///
+ /// ### Known problems
+ /// `unnecessary_to_owned` can falsely trigger if `IntoIterator::into_iter` is applied to an
+ /// owned copy of a resource and the resource is later used mutably. See
+ /// [#8148](https://github.com/rust-lang/rust-clippy/issues/8148).
+ ///
+ /// ### Example
+ /// ```rust
+ /// let path = std::path::Path::new("x");
+ /// foo(&path.to_string_lossy().to_string());
+ /// fn foo(s: &str) {}
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let path = std::path::Path::new("x");
+ /// foo(&path.to_string_lossy());
+ /// fn foo(s: &str) {}
+ /// ```
+ #[clippy::version = "1.58.0"]
+ pub UNNECESSARY_TO_OWNED,
+ perf,
+ "unnecessary calls to `to_owned`-like functions"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for use of `.collect::<Vec<String>>().join("")` on iterators.
+ ///
+ /// ### Why is this bad?
+ /// `.collect::<String>()` is more concise and might be more performant
+ ///
+ /// ### Example
+ /// ```rust
+ /// let vector = vec!["hello", "world"];
+ /// let output = vector.iter().map(|item| item.to_uppercase()).collect::<Vec<String>>().join("");
+ /// println!("{}", output);
+ /// ```
+ /// The correct use would be:
+ /// ```rust
+ /// let vector = vec!["hello", "world"];
+ /// let output = vector.iter().map(|item| item.to_uppercase()).collect::<String>();
+ /// println!("{}", output);
+ /// ```
+ /// ### Known problems
+ /// While `.collect::<String>()` is sometimes more performant, there are cases where
+ /// using `.collect::<String>()` over `.collect::<Vec<String>>().join("")`
+ /// will prevent loop unrolling and will result in a negative performance impact.
+ ///
+ /// Additionally, differences have been observed between aarch64 and x86_64 assembly output,
+ /// with aarch64 tending to producing faster assembly in more cases when using `.collect::<String>()`
+ #[clippy::version = "1.61.0"]
+ pub UNNECESSARY_JOIN,
+ pedantic,
+ "using `.collect::<Vec<String>>().join(\"\")` on an iterator"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for no-op uses of `Option::{as_deref, as_deref_mut}`,
+ /// for example, `Option<&T>::as_deref()` returns the same type.
+ ///
+ /// ### Why is this bad?
+ /// Redundant code and improving readability.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let a = Some(&1);
+ /// let b = a.as_deref(); // goes from Option<&i32> to Option<&i32>
+ /// ```
+ /// Could be written as:
+ /// ```rust
+ /// let a = Some(&1);
+ /// let b = a;
+ /// ```
+ #[clippy::version = "1.57.0"]
+ pub NEEDLESS_OPTION_AS_DEREF,
+ complexity,
+ "no-op use of `deref` or `deref_mut` method to `Option`."
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Finds usages of [`char::is_digit`]
+ /// (https://doc.rust-lang.org/stable/std/primitive.char.html#method.is_digit) that
+ /// can be replaced with [`is_ascii_digit`]
+ /// (https://doc.rust-lang.org/stable/std/primitive.char.html#method.is_ascii_digit) or
+ /// [`is_ascii_hexdigit`]
+ /// (https://doc.rust-lang.org/stable/std/primitive.char.html#method.is_ascii_hexdigit).
+ ///
+ /// ### Why is this bad?
+ /// `is_digit(..)` is slower and requires specifying the radix.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let c: char = '6';
+ /// c.is_digit(10);
+ /// c.is_digit(16);
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let c: char = '6';
+ /// c.is_ascii_digit();
+ /// c.is_ascii_hexdigit();
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub IS_DIGIT_ASCII_RADIX,
+ style,
+ "use of `char::is_digit(..)` with literal radix of 10 or 16"
+}
+
+declare_clippy_lint! {
+ ///
+ /// ### Why is this bad?
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = Some(3);
+ /// x.as_ref().take();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let x = Some(3);
+ /// x.as_ref();
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub NEEDLESS_OPTION_TAKE,
+ complexity,
+ "using `.as_ref().take()` on a temporary value"
+}
+
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for `replace` statements which have no effect.
++ ///
++ /// ### Why is this bad?
++ /// It's either a mistake or confusing.
++ ///
++ /// ### Example
++ /// ```rust
++ /// "1234".replace("12", "12");
++ /// "1234".replacen("12", "12", 1);
++ /// ```
++ #[clippy::version = "1.62.0"]
++ pub NO_EFFECT_REPLACE,
++ suspicious,
++ "replace with no effect"
++}
++
+pub struct Methods {
+ avoid_breaking_exported_api: bool,
+ msrv: Option<RustcVersion>,
+ allow_expect_in_tests: bool,
+ allow_unwrap_in_tests: bool,
+}
+
+impl Methods {
+ #[must_use]
+ pub fn new(
+ avoid_breaking_exported_api: bool,
+ msrv: Option<RustcVersion>,
+ allow_expect_in_tests: bool,
+ allow_unwrap_in_tests: bool,
+ ) -> Self {
+ Self {
+ avoid_breaking_exported_api,
+ msrv,
+ allow_expect_in_tests,
+ allow_unwrap_in_tests,
+ }
+ }
+}
+
+impl_lint_pass!(Methods => [
+ UNWRAP_USED,
+ EXPECT_USED,
+ SHOULD_IMPLEMENT_TRAIT,
+ WRONG_SELF_CONVENTION,
+ OK_EXPECT,
+ UNWRAP_OR_ELSE_DEFAULT,
+ MAP_UNWRAP_OR,
+ RESULT_MAP_OR_INTO_OPTION,
+ OPTION_MAP_OR_NONE,
+ BIND_INSTEAD_OF_MAP,
+ OR_FUN_CALL,
+ OR_THEN_UNWRAP,
+ EXPECT_FUN_CALL,
+ CHARS_NEXT_CMP,
+ CHARS_LAST_CMP,
+ CLONE_ON_COPY,
+ CLONE_ON_REF_PTR,
+ CLONE_DOUBLE_REF,
+ ITER_OVEREAGER_CLONED,
+ CLONED_INSTEAD_OF_COPIED,
+ FLAT_MAP_OPTION,
+ INEFFICIENT_TO_STRING,
+ NEW_RET_NO_SELF,
+ SINGLE_CHAR_PATTERN,
+ SINGLE_CHAR_ADD_STR,
+ SEARCH_IS_SOME,
+ FILTER_NEXT,
+ SKIP_WHILE_NEXT,
+ FILTER_MAP_IDENTITY,
+ MAP_IDENTITY,
+ MANUAL_FILTER_MAP,
+ MANUAL_FIND_MAP,
+ OPTION_FILTER_MAP,
+ FILTER_MAP_NEXT,
+ FLAT_MAP_IDENTITY,
+ MAP_FLATTEN,
+ ITERATOR_STEP_BY_ZERO,
+ ITER_NEXT_SLICE,
+ ITER_COUNT,
+ ITER_NTH,
+ ITER_NTH_ZERO,
+ BYTES_NTH,
+ ITER_SKIP_NEXT,
+ GET_UNWRAP,
++ GET_LAST_WITH_LEN,
+ STRING_EXTEND_CHARS,
+ ITER_CLONED_COLLECT,
+ ITER_WITH_DRAIN,
+ USELESS_ASREF,
+ UNNECESSARY_FOLD,
+ UNNECESSARY_FILTER_MAP,
+ UNNECESSARY_FIND_MAP,
+ INTO_ITER_ON_REF,
+ SUSPICIOUS_MAP,
+ UNINIT_ASSUMED_INIT,
+ MANUAL_SATURATING_ARITHMETIC,
+ ZST_OFFSET,
+ FILETYPE_IS_FILE,
+ OPTION_AS_REF_DEREF,
+ UNNECESSARY_LAZY_EVALUATIONS,
+ MAP_COLLECT_RESULT_UNIT,
+ FROM_ITER_INSTEAD_OF_COLLECT,
+ INSPECT_FOR_EACH,
+ IMPLICIT_CLONE,
+ SUSPICIOUS_SPLITN,
+ MANUAL_STR_REPEAT,
+ EXTEND_WITH_DRAIN,
+ MANUAL_SPLIT_ONCE,
+ NEEDLESS_SPLITN,
+ UNNECESSARY_TO_OWNED,
+ UNNECESSARY_JOIN,
+ ERR_EXPECT,
+ NEEDLESS_OPTION_AS_DEREF,
+ IS_DIGIT_ASCII_RADIX,
+ NEEDLESS_OPTION_TAKE,
++ NO_EFFECT_REPLACE,
+]);
+
+/// Extracts a method call name, args, and `Span` of the method name.
+fn method_call<'tcx>(recv: &'tcx hir::Expr<'tcx>) -> Option<(&'tcx str, &'tcx [hir::Expr<'tcx>], Span)> {
+ if let ExprKind::MethodCall(path, args, _) = recv.kind {
+ if !args.iter().any(|e| e.span.from_expansion()) {
+ let name = path.ident.name.as_str();
+ return Some((name, args, path.ident.span));
+ }
+ }
+ None
+}
+
+impl<'tcx> LateLintPass<'tcx> for Methods {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
+ if expr.span.from_expansion() {
+ return;
+ }
+
+ self.check_methods(cx, expr);
+
+ match expr.kind {
+ hir::ExprKind::Call(func, args) => {
+ from_iter_instead_of_collect::check(cx, expr, args, func);
+ },
+ hir::ExprKind::MethodCall(method_call, args, _) => {
+ let method_span = method_call.ident.span;
+ or_fun_call::check(cx, expr, method_span, method_call.ident.as_str(), args);
+ expect_fun_call::check(cx, expr, method_span, method_call.ident.as_str(), args);
+ clone_on_copy::check(cx, expr, method_call.ident.name, args);
+ clone_on_ref_ptr::check(cx, expr, method_call.ident.name, args);
+ inefficient_to_string::check(cx, expr, method_call.ident.name, args);
+ single_char_add_str::check(cx, expr, args);
+ into_iter_on_ref::check(cx, expr, method_span, method_call.ident.name, args);
+ single_char_pattern::check(cx, expr, method_call.ident.name, args);
+ unnecessary_to_owned::check(cx, expr, method_call.ident.name, args, self.msrv);
+ },
+ hir::ExprKind::Binary(op, lhs, rhs) if op.node == hir::BinOpKind::Eq || op.node == hir::BinOpKind::Ne => {
+ let mut info = BinaryExprInfo {
+ expr,
+ chain: lhs,
+ other: rhs,
+ eq: op.node == hir::BinOpKind::Eq,
+ };
+ lint_binary_expr_with_method_call(cx, &mut info);
+ },
+ _ => (),
+ }
+ }
+
+ #[allow(clippy::too_many_lines)]
+ fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx hir::ImplItem<'_>) {
+ if in_external_macro(cx.sess(), impl_item.span) {
+ return;
+ }
+ let name = impl_item.ident.name.as_str();
+ let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id());
+ let item = cx.tcx.hir().expect_item(parent);
+ let self_ty = cx.tcx.type_of(item.def_id);
+
+ let implements_trait = matches!(item.kind, hir::ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }));
+ if_chain! {
+ if let hir::ImplItemKind::Fn(ref sig, id) = impl_item.kind;
+ if let Some(first_arg) = iter_input_pats(sig.decl, cx.tcx.hir().body(id)).next();
+
+ let method_sig = cx.tcx.fn_sig(impl_item.def_id);
+ let method_sig = cx.tcx.erase_late_bound_regions(method_sig);
+
+ let first_arg_ty = method_sig.inputs().iter().next();
+
+ // check conventions w.r.t. conversion method names and predicates
+ if let Some(first_arg_ty) = first_arg_ty;
+
+ then {
+ // if this impl block implements a trait, lint in trait definition instead
+ if !implements_trait && cx.access_levels.is_exported(impl_item.def_id) {
+ // check missing trait implementations
+ for method_config in &TRAIT_METHODS {
+ if name == method_config.method_name &&
+ sig.decl.inputs.len() == method_config.param_count &&
+ method_config.output_type.matches(&sig.decl.output) &&
+ method_config.self_kind.matches(cx, self_ty, *first_arg_ty) &&
+ fn_header_equals(method_config.fn_header, sig.header) &&
+ method_config.lifetime_param_cond(impl_item)
+ {
+ span_lint_and_help(
+ cx,
+ SHOULD_IMPLEMENT_TRAIT,
+ impl_item.span,
+ &format!(
+ "method `{}` can be confused for the standard trait method `{}::{}`",
+ method_config.method_name,
+ method_config.trait_name,
+ method_config.method_name
+ ),
+ None,
+ &format!(
+ "consider implementing the trait `{}` or choosing a less ambiguous method name",
+ method_config.trait_name
+ )
+ );
+ }
+ }
+ }
+
+ if sig.decl.implicit_self.has_implicit_self()
+ && !(self.avoid_breaking_exported_api
+ && cx.access_levels.is_exported(impl_item.def_id))
+ {
+ wrong_self_convention::check(
+ cx,
+ name,
+ self_ty,
+ *first_arg_ty,
+ first_arg.pat.span,
+ implements_trait,
+ false
+ );
+ }
+ }
+ }
+
+ // if this impl block implements a trait, lint in trait definition instead
+ if implements_trait {
+ return;
+ }
+
+ if let hir::ImplItemKind::Fn(_, _) = impl_item.kind {
+ let ret_ty = return_ty(cx, impl_item.hir_id());
+
+ // walk the return type and check for Self (this does not check associated types)
+ if let Some(self_adt) = self_ty.ty_adt_def() {
+ if contains_adt_constructor(ret_ty, self_adt) {
+ return;
+ }
+ } else if contains_ty(ret_ty, self_ty) {
+ return;
+ }
+
+ // if return type is impl trait, check the associated types
+ if let ty::Opaque(def_id, _) = *ret_ty.kind() {
+ // one of the associated types must be Self
+ for &(predicate, _span) in cx.tcx.explicit_item_bounds(def_id) {
+ if let ty::PredicateKind::Projection(projection_predicate) = predicate.kind().skip_binder() {
+ let assoc_ty = match projection_predicate.term {
+ ty::Term::Ty(ty) => ty,
+ ty::Term::Const(_c) => continue,
+ };
+ // walk the associated type and check for Self
+ if let Some(self_adt) = self_ty.ty_adt_def() {
+ if contains_adt_constructor(assoc_ty, self_adt) {
+ return;
+ }
+ } else if contains_ty(assoc_ty, self_ty) {
+ return;
+ }
+ }
+ }
+ }
+
+ if name == "new" && ret_ty != self_ty {
+ span_lint(
+ cx,
+ NEW_RET_NO_SELF,
+ impl_item.span,
+ "methods called `new` usually return `Self`",
+ );
+ }
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'_>) {
+ if in_external_macro(cx.tcx.sess, item.span) {
+ return;
+ }
+
+ if_chain! {
+ if let TraitItemKind::Fn(ref sig, _) = item.kind;
+ if sig.decl.implicit_self.has_implicit_self();
+ if let Some(first_arg_ty) = sig.decl.inputs.iter().next();
+
+ then {
+ let first_arg_span = first_arg_ty.span;
+ let first_arg_ty = hir_ty_to_ty(cx.tcx, first_arg_ty);
+ let self_ty = TraitRef::identity(cx.tcx, item.def_id.to_def_id()).self_ty().skip_binder();
+ wrong_self_convention::check(
+ cx,
+ item.ident.name.as_str(),
+ self_ty,
+ first_arg_ty,
+ first_arg_span,
+ false,
+ true
+ );
+ }
+ }
+
+ if_chain! {
+ if item.ident.name == sym::new;
+ if let TraitItemKind::Fn(_, _) = item.kind;
+ let ret_ty = return_ty(cx, item.hir_id());
+ let self_ty = TraitRef::identity(cx.tcx, item.def_id.to_def_id()).self_ty().skip_binder();
+ if !contains_ty(ret_ty, self_ty);
+
+ then {
+ span_lint(
+ cx,
+ NEW_RET_NO_SELF,
+ item.span,
+ "methods called `new` usually return `Self`",
+ );
+ }
+ }
+ }
+
+ extract_msrv_attr!(LateContext);
+}
+
+impl Methods {
+ #[allow(clippy::too_many_lines)]
+ fn check_methods<'tcx>(&self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if let Some((name, [recv, args @ ..], span)) = method_call(expr) {
+ match (name, args) {
+ ("add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub", [_arg]) => {
+ zst_offset::check(cx, expr, recv);
+ },
+ ("and_then", [arg]) => {
+ let biom_option_linted = bind_instead_of_map::OptionAndThenSome::check(cx, expr, recv, arg);
+ let biom_result_linted = bind_instead_of_map::ResultAndThenOk::check(cx, expr, recv, arg);
+ if !biom_option_linted && !biom_result_linted {
+ unnecessary_lazy_eval::check(cx, expr, recv, arg, "and");
+ }
+ },
+ ("as_deref" | "as_deref_mut", []) => {
+ needless_option_as_deref::check(cx, expr, recv, name);
+ },
+ ("as_mut", []) => useless_asref::check(cx, expr, "as_mut", recv),
+ ("as_ref", []) => useless_asref::check(cx, expr, "as_ref", recv),
+ ("assume_init", []) => uninit_assumed_init::check(cx, expr, recv),
+ ("cloned", []) => cloned_instead_of_copied::check(cx, expr, recv, span, self.msrv),
+ ("collect", []) => match method_call(recv) {
+ Some((name @ ("cloned" | "copied"), [recv2], _)) => {
+ iter_cloned_collect::check(cx, name, expr, recv2);
+ },
+ Some(("map", [m_recv, m_arg], _)) => {
+ map_collect_result_unit::check(cx, expr, m_recv, m_arg, recv);
+ },
+ Some(("take", [take_self_arg, take_arg], _)) => {
+ if meets_msrv(self.msrv, msrvs::STR_REPEAT) {
+ manual_str_repeat::check(cx, expr, recv, take_self_arg, take_arg);
+ }
+ },
+ _ => {},
+ },
+ (name @ "count", args @ []) => match method_call(recv) {
+ Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
+ Some((name2 @ ("into_iter" | "iter" | "iter_mut"), [recv2], _)) => {
+ iter_count::check(cx, expr, recv2, name2);
+ },
+ Some(("map", [_, arg], _)) => suspicious_map::check(cx, expr, recv, arg),
+ _ => {},
+ },
+ ("drain", [arg]) => {
+ iter_with_drain::check(cx, expr, recv, span, arg);
+ },
+ ("expect", [_]) => match method_call(recv) {
+ Some(("ok", [recv], _)) => ok_expect::check(cx, expr, recv),
+ Some(("err", [recv], err_span)) => err_expect::check(cx, expr, recv, self.msrv, span, err_span),
+ _ => expect_used::check(cx, expr, recv, self.allow_expect_in_tests),
+ },
+ ("extend", [arg]) => {
+ string_extend_chars::check(cx, expr, recv, arg);
+ extend_with_drain::check(cx, expr, recv, arg);
+ },
+ ("filter_map", [arg]) => {
+ unnecessary_filter_map::check(cx, expr, arg, name);
+ filter_map_identity::check(cx, expr, arg, span);
+ },
+ ("find_map", [arg]) => {
+ unnecessary_filter_map::check(cx, expr, arg, name);
+ },
+ ("flat_map", [arg]) => {
+ flat_map_identity::check(cx, expr, arg, span);
+ flat_map_option::check(cx, expr, arg, span);
+ },
+ (name @ "flatten", args @ []) => match method_call(recv) {
+ Some(("map", [recv, map_arg], map_span)) => map_flatten::check(cx, expr, recv, map_arg, map_span),
+ Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
+ _ => {},
+ },
+ ("fold", [init, acc]) => unnecessary_fold::check(cx, expr, init, acc, span),
+ ("for_each", [_]) => {
+ if let Some(("inspect", [_, _], span2)) = method_call(recv) {
+ inspect_for_each::check(cx, expr, span2);
+ }
+ },
++ ("get", [arg]) => get_last_with_len::check(cx, expr, recv, arg),
+ ("get_or_insert_with", [arg]) => unnecessary_lazy_eval::check(cx, expr, recv, arg, "get_or_insert"),
+ ("is_file", []) => filetype_is_file::check(cx, expr, recv),
+ ("is_digit", [radix]) => is_digit_ascii_radix::check(cx, expr, recv, radix, self.msrv),
+ ("is_none", []) => check_is_some_is_none(cx, expr, recv, false),
+ ("is_some", []) => check_is_some_is_none(cx, expr, recv, true),
+ ("join", [join_arg]) => {
+ if let Some(("collect", _, span)) = method_call(recv) {
+ unnecessary_join::check(cx, expr, recv, join_arg, span);
+ }
+ },
+ ("last", args @ []) | ("skip", args @ [_]) => {
+ if let Some((name2, [recv2, args2 @ ..], _span2)) = method_call(recv) {
+ if let ("cloned", []) = (name2, args2) {
+ iter_overeager_cloned::check(cx, expr, recv2, name, args);
+ }
+ }
+ },
+ (name @ ("map" | "map_err"), [m_arg]) => {
+ if let Some((name, [recv2, args @ ..], span2)) = method_call(recv) {
+ match (name, args) {
+ ("as_mut", []) => option_as_ref_deref::check(cx, expr, recv2, m_arg, true, self.msrv),
+ ("as_ref", []) => option_as_ref_deref::check(cx, expr, recv2, m_arg, false, self.msrv),
+ ("filter", [f_arg]) => {
+ filter_map::check(cx, expr, recv2, f_arg, span2, recv, m_arg, span, false);
+ },
+ ("find", [f_arg]) => {
+ filter_map::check(cx, expr, recv2, f_arg, span2, recv, m_arg, span, true);
+ },
+ _ => {},
+ }
+ }
+ map_identity::check(cx, expr, recv, m_arg, name, span);
+ },
+ ("map_or", [def, map]) => option_map_or_none::check(cx, expr, recv, def, map),
+ (name @ "next", args @ []) => {
+ if let Some((name2, [recv2, args2 @ ..], _)) = method_call(recv) {
+ match (name2, args2) {
+ ("cloned", []) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
+ ("filter", [arg]) => filter_next::check(cx, expr, recv2, arg),
+ ("filter_map", [arg]) => filter_map_next::check(cx, expr, recv2, arg, self.msrv),
+ ("iter", []) => iter_next_slice::check(cx, expr, recv2),
+ ("skip", [arg]) => iter_skip_next::check(cx, expr, recv2, arg),
+ ("skip_while", [_]) => skip_while_next::check(cx, expr),
+ _ => {},
+ }
+ }
+ },
+ ("nth", args @ [n_arg]) => match method_call(recv) {
+ Some(("bytes", [recv2], _)) => bytes_nth::check(cx, expr, recv2, n_arg),
+ Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
+ Some(("iter", [recv2], _)) => iter_nth::check(cx, expr, recv2, recv, n_arg, false),
+ Some(("iter_mut", [recv2], _)) => iter_nth::check(cx, expr, recv2, recv, n_arg, true),
+ _ => iter_nth_zero::check(cx, expr, recv, n_arg),
+ },
+ ("ok_or_else", [arg]) => unnecessary_lazy_eval::check(cx, expr, recv, arg, "ok_or"),
+ ("or_else", [arg]) => {
+ if !bind_instead_of_map::ResultOrElseErrInfo::check(cx, expr, recv, arg) {
+ unnecessary_lazy_eval::check(cx, expr, recv, arg, "or");
+ }
+ },
+ ("splitn" | "rsplitn", [count_arg, pat_arg]) => {
+ if let Some((Constant::Int(count), _)) = constant(cx, cx.typeck_results(), count_arg) {
+ suspicious_splitn::check(cx, name, expr, recv, count);
+ str_splitn::check(cx, name, expr, recv, pat_arg, count, self.msrv);
+ }
+ },
+ ("splitn_mut" | "rsplitn_mut", [count_arg, _]) => {
+ if let Some((Constant::Int(count), _)) = constant(cx, cx.typeck_results(), count_arg) {
+ suspicious_splitn::check(cx, name, expr, recv, count);
+ }
+ },
+ ("step_by", [arg]) => iterator_step_by_zero::check(cx, expr, arg),
+ ("take", args @ [_arg]) => {
+ if let Some((name2, [recv2, args2 @ ..], _span2)) = method_call(recv) {
+ if let ("cloned", []) = (name2, args2) {
+ iter_overeager_cloned::check(cx, expr, recv2, name, args);
+ }
+ }
+ },
+ ("take", []) => needless_option_take::check(cx, expr, recv),
+ ("to_os_string" | "to_owned" | "to_path_buf" | "to_vec", []) => {
+ implicit_clone::check(cx, name, expr, recv);
+ },
+ ("unwrap", []) => {
+ match method_call(recv) {
+ Some(("get", [recv, get_arg], _)) => {
+ get_unwrap::check(cx, expr, recv, get_arg, false);
+ },
+ Some(("get_mut", [recv, get_arg], _)) => {
+ get_unwrap::check(cx, expr, recv, get_arg, true);
+ },
+ Some(("or", [recv, or_arg], or_span)) => {
+ or_then_unwrap::check(cx, expr, recv, or_arg, or_span);
+ },
+ _ => {},
+ }
+ unwrap_used::check(cx, expr, recv, self.allow_unwrap_in_tests);
+ },
+ ("unwrap_or", [u_arg]) => match method_call(recv) {
+ Some((arith @ ("checked_add" | "checked_sub" | "checked_mul"), [lhs, rhs], _)) => {
+ manual_saturating_arithmetic::check(cx, expr, lhs, rhs, u_arg, &arith["checked_".len()..]);
+ },
+ Some(("map", [m_recv, m_arg], span)) => {
+ option_map_unwrap_or::check(cx, expr, m_recv, m_arg, recv, u_arg, span);
+ },
+ _ => {},
+ },
+ ("unwrap_or_else", [u_arg]) => match method_call(recv) {
+ Some(("map", [recv, map_arg], _))
+ if map_unwrap_or::check(cx, expr, recv, map_arg, u_arg, self.msrv) => {},
+ _ => {
+ unwrap_or_else_default::check(cx, expr, recv, u_arg);
+ unnecessary_lazy_eval::check(cx, expr, recv, u_arg, "unwrap_or");
+ },
+ },
++ ("replace" | "replacen", [arg1, arg2] | [arg1, arg2, _]) => {
++ no_effect_replace::check(cx, expr, arg1, arg2);
++ },
+ _ => {},
+ }
+ }
+ }
+}
+
+fn check_is_some_is_none(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, is_some: bool) {
+ if let Some((name @ ("find" | "position" | "rposition"), [f_recv, arg], span)) = method_call(recv) {
+ search_is_some::check(cx, expr, name, is_some, f_recv, arg, recv, span);
+ }
+}
+
+/// Used for `lint_binary_expr_with_method_call`.
+#[derive(Copy, Clone)]
+struct BinaryExprInfo<'a> {
+ expr: &'a hir::Expr<'a>,
+ chain: &'a hir::Expr<'a>,
+ other: &'a hir::Expr<'a>,
+ eq: bool,
+}
+
+/// Checks for the `CHARS_NEXT_CMP` and `CHARS_LAST_CMP` lints.
+fn lint_binary_expr_with_method_call(cx: &LateContext<'_>, info: &mut BinaryExprInfo<'_>) {
+ macro_rules! lint_with_both_lhs_and_rhs {
+ ($func:expr, $cx:expr, $info:ident) => {
+ if !$func($cx, $info) {
+ ::std::mem::swap(&mut $info.chain, &mut $info.other);
+ if $func($cx, $info) {
+ return;
+ }
+ }
+ };
+ }
+
+ lint_with_both_lhs_and_rhs!(chars_next_cmp::check, cx, info);
+ lint_with_both_lhs_and_rhs!(chars_last_cmp::check, cx, info);
+ lint_with_both_lhs_and_rhs!(chars_next_cmp_with_unwrap::check, cx, info);
+ lint_with_both_lhs_and_rhs!(chars_last_cmp_with_unwrap::check, cx, info);
+}
+
+const FN_HEADER: hir::FnHeader = hir::FnHeader {
+ unsafety: hir::Unsafety::Normal,
+ constness: hir::Constness::NotConst,
+ asyncness: hir::IsAsync::NotAsync,
+ abi: rustc_target::spec::abi::Abi::Rust,
+};
+
+struct ShouldImplTraitCase {
+ trait_name: &'static str,
+ method_name: &'static str,
+ param_count: usize,
+ fn_header: hir::FnHeader,
+ // implicit self kind expected (none, self, &self, ...)
+ self_kind: SelfKind,
+ // checks against the output type
+ output_type: OutType,
+ // certain methods with explicit lifetimes can't implement the equivalent trait method
+ lint_explicit_lifetime: bool,
+}
+impl ShouldImplTraitCase {
+ const fn new(
+ trait_name: &'static str,
+ method_name: &'static str,
+ param_count: usize,
+ fn_header: hir::FnHeader,
+ self_kind: SelfKind,
+ output_type: OutType,
+ lint_explicit_lifetime: bool,
+ ) -> ShouldImplTraitCase {
+ ShouldImplTraitCase {
+ trait_name,
+ method_name,
+ param_count,
+ fn_header,
+ self_kind,
+ output_type,
+ lint_explicit_lifetime,
+ }
+ }
+
+ fn lifetime_param_cond(&self, impl_item: &hir::ImplItem<'_>) -> bool {
+ self.lint_explicit_lifetime
+ || !impl_item.generics.params.iter().any(|p| {
+ matches!(
+ p.kind,
+ hir::GenericParamKind::Lifetime {
+ kind: hir::LifetimeParamKind::Explicit
+ }
+ )
+ })
+ }
+}
+
+#[rustfmt::skip]
+const TRAIT_METHODS: [ShouldImplTraitCase; 30] = [
+ ShouldImplTraitCase::new("std::ops::Add", "add", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::convert::AsMut", "as_mut", 1, FN_HEADER, SelfKind::RefMut, OutType::Ref, true),
+ ShouldImplTraitCase::new("std::convert::AsRef", "as_ref", 1, FN_HEADER, SelfKind::Ref, OutType::Ref, true),
+ ShouldImplTraitCase::new("std::ops::BitAnd", "bitand", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::ops::BitOr", "bitor", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::ops::BitXor", "bitxor", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::borrow::Borrow", "borrow", 1, FN_HEADER, SelfKind::Ref, OutType::Ref, true),
+ ShouldImplTraitCase::new("std::borrow::BorrowMut", "borrow_mut", 1, FN_HEADER, SelfKind::RefMut, OutType::Ref, true),
+ ShouldImplTraitCase::new("std::clone::Clone", "clone", 1, FN_HEADER, SelfKind::Ref, OutType::Any, true),
+ ShouldImplTraitCase::new("std::cmp::Ord", "cmp", 2, FN_HEADER, SelfKind::Ref, OutType::Any, true),
+ // FIXME: default doesn't work
+ ShouldImplTraitCase::new("std::default::Default", "default", 0, FN_HEADER, SelfKind::No, OutType::Any, true),
+ ShouldImplTraitCase::new("std::ops::Deref", "deref", 1, FN_HEADER, SelfKind::Ref, OutType::Ref, true),
+ ShouldImplTraitCase::new("std::ops::DerefMut", "deref_mut", 1, FN_HEADER, SelfKind::RefMut, OutType::Ref, true),
+ ShouldImplTraitCase::new("std::ops::Div", "div", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::ops::Drop", "drop", 1, FN_HEADER, SelfKind::RefMut, OutType::Unit, true),
+ ShouldImplTraitCase::new("std::cmp::PartialEq", "eq", 2, FN_HEADER, SelfKind::Ref, OutType::Bool, true),
+ ShouldImplTraitCase::new("std::iter::FromIterator", "from_iter", 1, FN_HEADER, SelfKind::No, OutType::Any, true),
+ ShouldImplTraitCase::new("std::str::FromStr", "from_str", 1, FN_HEADER, SelfKind::No, OutType::Any, true),
+ ShouldImplTraitCase::new("std::hash::Hash", "hash", 2, FN_HEADER, SelfKind::Ref, OutType::Unit, true),
+ ShouldImplTraitCase::new("std::ops::Index", "index", 2, FN_HEADER, SelfKind::Ref, OutType::Ref, true),
+ ShouldImplTraitCase::new("std::ops::IndexMut", "index_mut", 2, FN_HEADER, SelfKind::RefMut, OutType::Ref, true),
+ ShouldImplTraitCase::new("std::iter::IntoIterator", "into_iter", 1, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::ops::Mul", "mul", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::ops::Neg", "neg", 1, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::iter::Iterator", "next", 1, FN_HEADER, SelfKind::RefMut, OutType::Any, false),
+ ShouldImplTraitCase::new("std::ops::Not", "not", 1, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::ops::Rem", "rem", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::ops::Shl", "shl", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::ops::Shr", "shr", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
+ ShouldImplTraitCase::new("std::ops::Sub", "sub", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
+];
+
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+enum SelfKind {
+ Value,
+ Ref,
+ RefMut,
+ No,
+}
+
+impl SelfKind {
+ fn matches<'a>(self, cx: &LateContext<'a>, parent_ty: Ty<'a>, ty: Ty<'a>) -> bool {
+ fn matches_value<'a>(cx: &LateContext<'a>, parent_ty: Ty<'a>, ty: Ty<'a>) -> bool {
+ if ty == parent_ty {
+ true
+ } else if ty.is_box() {
+ ty.boxed_ty() == parent_ty
+ } else if is_type_diagnostic_item(cx, ty, sym::Rc) || is_type_diagnostic_item(cx, ty, sym::Arc) {
+ if let ty::Adt(_, substs) = ty.kind() {
+ substs.types().next().map_or(false, |t| t == parent_ty)
+ } else {
+ false
+ }
+ } else {
+ false
+ }
+ }
+
+ fn matches_ref<'a>(cx: &LateContext<'a>, mutability: hir::Mutability, parent_ty: Ty<'a>, ty: Ty<'a>) -> bool {
+ if let ty::Ref(_, t, m) = *ty.kind() {
+ return m == mutability && t == parent_ty;
+ }
+
+ let trait_path = match mutability {
+ hir::Mutability::Not => &paths::ASREF_TRAIT,
+ hir::Mutability::Mut => &paths::ASMUT_TRAIT,
+ };
+
+ let trait_def_id = match get_trait_def_id(cx, trait_path) {
+ Some(did) => did,
+ None => return false,
+ };
+ implements_trait(cx, ty, trait_def_id, &[parent_ty.into()])
+ }
+
+ fn matches_none<'a>(cx: &LateContext<'a>, parent_ty: Ty<'a>, ty: Ty<'a>) -> bool {
+ !matches_value(cx, parent_ty, ty)
+ && !matches_ref(cx, hir::Mutability::Not, parent_ty, ty)
+ && !matches_ref(cx, hir::Mutability::Mut, parent_ty, ty)
+ }
+
+ match self {
+ Self::Value => matches_value(cx, parent_ty, ty),
+ Self::Ref => matches_ref(cx, hir::Mutability::Not, parent_ty, ty) || ty == parent_ty && is_copy(cx, ty),
+ Self::RefMut => matches_ref(cx, hir::Mutability::Mut, parent_ty, ty),
+ Self::No => matches_none(cx, parent_ty, ty),
+ }
+ }
+
+ #[must_use]
+ fn description(self) -> &'static str {
+ match self {
+ Self::Value => "`self` by value",
+ Self::Ref => "`self` by reference",
+ Self::RefMut => "`self` by mutable reference",
+ Self::No => "no `self`",
+ }
+ }
+}
+
+#[derive(Clone, Copy)]
+enum OutType {
+ Unit,
+ Bool,
+ Any,
+ Ref,
+}
+
+impl OutType {
+ fn matches(self, ty: &hir::FnRetTy<'_>) -> bool {
+ let is_unit = |ty: &hir::Ty<'_>| matches!(ty.kind, hir::TyKind::Tup(&[]));
+ match (self, ty) {
+ (Self::Unit, &hir::FnRetTy::DefaultReturn(_)) => true,
+ (Self::Unit, &hir::FnRetTy::Return(ty)) if is_unit(ty) => true,
+ (Self::Bool, &hir::FnRetTy::Return(ty)) if is_bool(ty) => true,
+ (Self::Any, &hir::FnRetTy::Return(ty)) if !is_unit(ty) => true,
+ (Self::Ref, &hir::FnRetTy::Return(ty)) => matches!(ty.kind, hir::TyKind::Rptr(_, _)),
+ _ => false,
+ }
+ }
+}
+
+fn is_bool(ty: &hir::Ty<'_>) -> bool {
+ if let hir::TyKind::Path(QPath::Resolved(_, path)) = ty.kind {
+ matches!(path.res, Res::PrimTy(PrimTy::Bool))
+ } else {
+ false
+ }
+}
+
+fn fn_header_equals(expected: hir::FnHeader, actual: hir::FnHeader) -> bool {
+ expected.constness == actual.constness
+ && expected.unsafety == actual.unsafety
+ && expected.asyncness == actual.asyncness
+}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint;
++use clippy_utils::ty::is_type_diagnostic_item;
++use clippy_utils::SpanlessEq;
++use if_chain::if_chain;
++use rustc_ast::LitKind;
++use rustc_hir::ExprKind;
++use rustc_lint::LateContext;
++use rustc_span::sym;
++
++use super::NO_EFFECT_REPLACE;
++
++pub(super) fn check<'tcx>(
++ cx: &LateContext<'tcx>,
++ expr: &'tcx rustc_hir::Expr<'_>,
++ arg1: &'tcx rustc_hir::Expr<'_>,
++ arg2: &'tcx rustc_hir::Expr<'_>,
++) {
++ let ty = cx.typeck_results().expr_ty(expr).peel_refs();
++ if !(ty.is_str() || is_type_diagnostic_item(cx, ty, sym::String)) {
++ return;
++ }
++
++ if_chain! {
++ if let ExprKind::Lit(spanned) = &arg1.kind;
++ if let Some(param1) = lit_string_value(&spanned.node);
++
++ if let ExprKind::Lit(spanned) = &arg2.kind;
++ if let LitKind::Str(param2, _) = &spanned.node;
++ if param1 == param2.as_str();
++
++ then {
++ span_lint(cx, NO_EFFECT_REPLACE, expr.span, "replacing text with itself");
++ }
++ }
++
++ if SpanlessEq::new(cx).eq_expr(arg1, arg2) {
++ span_lint(cx, NO_EFFECT_REPLACE, expr.span, "replacing text with itself");
++ }
++}
++
++fn lit_string_value(node: &LitKind) -> Option<String> {
++ match node {
++ LitKind::Char(value) => Some(value.to_string()),
++ LitKind::Str(value, _) => Some(value.as_str().to_owned()),
++ _ => None,
++ }
++}
--- /dev/null
- return span_lint_and_sugg(
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::{is_lang_ctor, path_def_id};
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::LangItem::{OptionNone, OptionSome};
+use rustc_lint::LateContext;
+use rustc_middle::ty::DefIdTree;
+use rustc_span::symbol::sym;
+
+use super::OPTION_MAP_OR_NONE;
+use super::RESULT_MAP_OR_INTO_OPTION;
+
+// The expression inside a closure may or may not have surrounding braces
+// which causes problems when generating a suggestion.
+fn reduce_unit_expression<'a>(expr: &'a hir::Expr<'_>) -> Option<(&'a hir::Expr<'a>, &'a [hir::Expr<'a>])> {
+ match expr.kind {
+ hir::ExprKind::Call(func, arg_char) => Some((func, arg_char)),
+ hir::ExprKind::Block(block, _) => {
+ match (block.stmts, block.expr) {
+ (&[], Some(inner_expr)) => {
+ // If block only contains an expression,
+ // reduce `|x| { x + 1 }` to `|x| x + 1`
+ reduce_unit_expression(inner_expr)
+ },
+ _ => None,
+ }
+ },
+ _ => None,
+ }
+}
+
+/// lint use of `_.map_or(None, _)` for `Option`s and `Result`s
+pub(super) fn check<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx hir::Expr<'_>,
+ recv: &'tcx hir::Expr<'_>,
+ def_arg: &'tcx hir::Expr<'_>,
+ map_arg: &'tcx hir::Expr<'_>,
+) {
+ let is_option = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(recv), sym::Option);
+ let is_result = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(recv), sym::Result);
+
+ // There are two variants of this `map_or` lint:
+ // (1) using `map_or` as an adapter from `Result<T,E>` to `Option<T>`
+ // (2) using `map_or` as a combinator instead of `and_then`
+ //
+ // (For this lint) we don't care if any other type calls `map_or`
+ if !is_option && !is_result {
+ return;
+ }
+
+ let default_arg_is_none = if let hir::ExprKind::Path(ref qpath) = def_arg.kind {
+ is_lang_ctor(cx, qpath, OptionNone)
+ } else {
+ return;
+ };
+
+ if !default_arg_is_none {
+ // nothing to lint!
+ return;
+ }
+
+ let f_arg_is_some = if let hir::ExprKind::Path(ref qpath) = map_arg.kind {
+ is_lang_ctor(cx, qpath, OptionSome)
+ } else {
+ false
+ };
+
+ if is_option {
+ let self_snippet = snippet(cx, recv.span, "..");
+ if_chain! {
+ if let hir::ExprKind::Closure(_, _, id, span, _) = map_arg.kind;
+ let arg_snippet = snippet(cx, span, "..");
+ let body = cx.tcx.hir().body(id);
+ if let Some((func, [arg_char])) = reduce_unit_expression(&body.value);
+ if let Some(id) = path_def_id(cx, func).map(|ctor_id| cx.tcx.parent(ctor_id));
+ if Some(id) == cx.tcx.lang_items().option_some_variant();
+ then {
+ let func_snippet = snippet(cx, arg_char.span, "..");
+ let msg = "called `map_or(None, ..)` on an `Option` value. This can be done more directly by calling \
+ `map(..)` instead";
+ return span_lint_and_sugg(
+ cx,
+ OPTION_MAP_OR_NONE,
+ expr.span,
+ msg,
+ "try using `map` instead",
+ format!("{0}.map({1} {2})", self_snippet, arg_snippet,func_snippet),
+ Applicability::MachineApplicable,
+ );
+ }
+
+ }
+
+ let func_snippet = snippet(cx, map_arg.span, "..");
+ let msg = "called `map_or(None, ..)` on an `Option` value. This can be done more directly by calling \
+ `and_then(..)` instead";
- return span_lint_and_sugg(
++ span_lint_and_sugg(
+ cx,
+ OPTION_MAP_OR_NONE,
+ expr.span,
+ msg,
+ "try using `and_then` instead",
+ format!("{0}.and_then({1})", self_snippet, func_snippet),
+ Applicability::MachineApplicable,
+ );
+ } else if f_arg_is_some {
+ let msg = "called `map_or(None, Some)` on a `Result` value. This can be done more directly by calling \
+ `ok()` instead";
+ let self_snippet = snippet(cx, recv.span, "..");
++ span_lint_and_sugg(
+ cx,
+ RESULT_MAP_OR_INTO_OPTION,
+ expr.span,
+ msg,
+ "try using `ok` instead",
+ format!("{0}.ok()", self_snippet),
+ Applicability::MachineApplicable,
+ );
+ }
+}
--- /dev/null
- is_clone_like(cx, &*method_name.as_str(), method_def_id)
+use super::implicit_clone::is_clone_like;
+use super::unnecessary_iter_cloned::{self, is_into_iter};
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_opt;
+use clippy_utils::ty::{
+ contains_ty, get_associated_type, get_iterator_item_ty, implements_trait, is_copy, peel_mid_ty_refs,
+};
+use clippy_utils::{meets_msrv, msrvs};
+
+use clippy_utils::{fn_def_id, get_parent_expr, is_diag_item_method, is_diag_trait_item};
+use rustc_errors::Applicability;
+use rustc_hir::{def_id::DefId, BorrowKind, Expr, ExprKind};
+use rustc_lint::LateContext;
+use rustc_middle::mir::Mutability;
+use rustc_middle::ty::adjustment::{Adjust, Adjustment, OverloadedDeref};
+use rustc_middle::ty::subst::{GenericArg, GenericArgKind, SubstsRef};
+use rustc_middle::ty::{self, PredicateKind, ProjectionPredicate, TraitPredicate, Ty};
+use rustc_semver::RustcVersion;
+use rustc_span::{sym, Symbol};
+use std::cmp::max;
+
+use super::UNNECESSARY_TO_OWNED;
+
+pub fn check<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx Expr<'tcx>,
+ method_name: Symbol,
+ args: &'tcx [Expr<'tcx>],
+ msrv: Option<RustcVersion>,
+) {
+ if_chain! {
+ if let Some(method_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
+ if let [receiver] = args;
+ then {
+ if is_cloned_or_copied(cx, method_name, method_def_id) {
+ unnecessary_iter_cloned::check(cx, expr, method_name, receiver);
+ } else if is_to_owned_like(cx, method_name, method_def_id) {
+ // At this point, we know the call is of a `to_owned`-like function. The functions
+ // `check_addr_of_expr` and `check_call_arg` determine whether the call is unnecessary
+ // based on its context, that is, whether it is a referent in an `AddrOf` expression, an
+ // argument in a `into_iter` call, or an argument in the call of some other function.
+ if check_addr_of_expr(cx, expr, method_name, method_def_id, receiver) {
+ return;
+ }
+ if check_into_iter_call_arg(cx, expr, method_name, receiver, msrv) {
+ return;
+ }
+ check_other_call_arg(cx, expr, method_name, receiver);
+ }
+ }
+ }
+}
+
+/// Checks whether `expr` is a referent in an `AddrOf` expression and, if so, determines whether its
+/// call of a `to_owned`-like function is unnecessary.
+#[allow(clippy::too_many_lines)]
+fn check_addr_of_expr(
+ cx: &LateContext<'_>,
+ expr: &Expr<'_>,
+ method_name: Symbol,
+ method_def_id: DefId,
+ receiver: &Expr<'_>,
+) -> bool {
+ if_chain! {
+ if let Some(parent) = get_parent_expr(cx, expr);
+ if let ExprKind::AddrOf(BorrowKind::Ref, Mutability::Not, _) = parent.kind;
+ let adjustments = cx.typeck_results().expr_adjustments(parent).iter().collect::<Vec<_>>();
+ if let
+ // For matching uses of `Cow::from`
+ [
+ Adjustment {
+ kind: Adjust::Deref(None),
+ target: referent_ty,
+ },
+ Adjustment {
+ kind: Adjust::Borrow(_),
+ target: target_ty,
+ },
+ ]
+ // For matching uses of arrays
+ | [
+ Adjustment {
+ kind: Adjust::Deref(None),
+ target: referent_ty,
+ },
+ Adjustment {
+ kind: Adjust::Borrow(_),
+ ..
+ },
+ Adjustment {
+ kind: Adjust::Pointer(_),
+ target: target_ty,
+ },
+ ]
+ // For matching everything else
+ | [
+ Adjustment {
+ kind: Adjust::Deref(None),
+ target: referent_ty,
+ },
+ Adjustment {
+ kind: Adjust::Deref(Some(OverloadedDeref { .. })),
+ ..
+ },
+ Adjustment {
+ kind: Adjust::Borrow(_),
+ target: target_ty,
+ },
+ ] = adjustments[..];
+ let receiver_ty = cx.typeck_results().expr_ty(receiver);
+ let (target_ty, n_target_refs) = peel_mid_ty_refs(*target_ty);
+ let (receiver_ty, n_receiver_refs) = peel_mid_ty_refs(receiver_ty);
+ // Only flag cases satisfying at least one of the following three conditions:
+ // * the referent and receiver types are distinct
+ // * the referent/receiver type is a copyable array
+ // * the method is `Cow::into_owned`
+ // This restriction is to ensure there is no overlap between `redundant_clone` and this
+ // lint. It also avoids the following false positive:
+ // https://github.com/rust-lang/rust-clippy/issues/8759
+ // Arrays are a bit of a corner case. Non-copyable arrays are handled by
+ // `redundant_clone`, but copyable arrays are not.
+ if *referent_ty != receiver_ty
+ || (matches!(referent_ty.kind(), ty::Array(..)) && is_copy(cx, *referent_ty))
+ || is_cow_into_owned(cx, method_name, method_def_id);
+ if let Some(receiver_snippet) = snippet_opt(cx, receiver.span);
+ then {
+ if receiver_ty == target_ty && n_target_refs >= n_receiver_refs {
+ span_lint_and_sugg(
+ cx,
+ UNNECESSARY_TO_OWNED,
+ parent.span,
+ &format!("unnecessary use of `{}`", method_name),
+ "use",
+ format!(
+ "{:&>width$}{}",
+ "",
+ receiver_snippet,
+ width = n_target_refs - n_receiver_refs
+ ),
+ Applicability::MachineApplicable,
+ );
+ return true;
+ }
+ if_chain! {
+ if let Some(deref_trait_id) = cx.tcx.get_diagnostic_item(sym::Deref);
+ if implements_trait(cx, receiver_ty, deref_trait_id, &[]);
+ if get_associated_type(cx, receiver_ty, deref_trait_id, "Target") == Some(target_ty);
+ then {
+ if n_receiver_refs > 0 {
+ span_lint_and_sugg(
+ cx,
+ UNNECESSARY_TO_OWNED,
+ parent.span,
+ &format!("unnecessary use of `{}`", method_name),
+ "use",
+ receiver_snippet,
+ Applicability::MachineApplicable,
+ );
+ } else {
+ span_lint_and_sugg(
+ cx,
+ UNNECESSARY_TO_OWNED,
+ expr.span.with_lo(receiver.span.hi()),
+ &format!("unnecessary use of `{}`", method_name),
+ "remove this",
+ String::new(),
+ Applicability::MachineApplicable,
+ );
+ }
+ return true;
+ }
+ }
+ if_chain! {
+ if let Some(as_ref_trait_id) = cx.tcx.get_diagnostic_item(sym::AsRef);
+ if implements_trait(cx, receiver_ty, as_ref_trait_id, &[GenericArg::from(target_ty)]);
+ then {
+ span_lint_and_sugg(
+ cx,
+ UNNECESSARY_TO_OWNED,
+ parent.span,
+ &format!("unnecessary use of `{}`", method_name),
+ "use",
+ format!("{}.as_ref()", receiver_snippet),
+ Applicability::MachineApplicable,
+ );
+ return true;
+ }
+ }
+ }
+ }
+ false
+}
+
+/// Checks whether `expr` is an argument in an `into_iter` call and, if so, determines whether its
+/// call of a `to_owned`-like function is unnecessary.
+fn check_into_iter_call_arg(
+ cx: &LateContext<'_>,
+ expr: &Expr<'_>,
+ method_name: Symbol,
+ receiver: &Expr<'_>,
+ msrv: Option<RustcVersion>,
+) -> bool {
+ if_chain! {
+ if let Some(parent) = get_parent_expr(cx, expr);
+ if let Some(callee_def_id) = fn_def_id(cx, parent);
+ if is_into_iter(cx, callee_def_id);
+ if let Some(iterator_trait_id) = cx.tcx.get_diagnostic_item(sym::Iterator);
+ let parent_ty = cx.typeck_results().expr_ty(parent);
+ if implements_trait(cx, parent_ty, iterator_trait_id, &[]);
+ if let Some(item_ty) = get_iterator_item_ty(cx, parent_ty);
+ if let Some(receiver_snippet) = snippet_opt(cx, receiver.span);
+ then {
+ if unnecessary_iter_cloned::check_for_loop_iter(cx, parent, method_name, receiver, true) {
+ return true;
+ }
+ let cloned_or_copied = if is_copy(cx, item_ty) && meets_msrv(msrv, msrvs::ITERATOR_COPIED) {
+ "copied"
+ } else {
+ "cloned"
+ };
+ // The next suggestion may be incorrect because the removal of the `to_owned`-like
+ // function could cause the iterator to hold a reference to a resource that is used
+ // mutably. See https://github.com/rust-lang/rust-clippy/issues/8148.
+ span_lint_and_sugg(
+ cx,
+ UNNECESSARY_TO_OWNED,
+ parent.span,
+ &format!("unnecessary use of `{}`", method_name),
+ "use",
+ format!("{}.iter().{}()", receiver_snippet, cloned_or_copied),
+ Applicability::MaybeIncorrect,
+ );
+ return true;
+ }
+ }
+ false
+}
+
+/// Checks whether `expr` is an argument in a function call and, if so, determines whether its call
+/// of a `to_owned`-like function is unnecessary.
+fn check_other_call_arg<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx Expr<'tcx>,
+ method_name: Symbol,
+ receiver: &'tcx Expr<'tcx>,
+) -> bool {
+ if_chain! {
+ if let Some((maybe_call, maybe_arg)) = skip_addr_of_ancestors(cx, expr);
+ if let Some((callee_def_id, call_substs, call_args)) = get_callee_substs_and_args(cx, maybe_call);
+ let fn_sig = cx.tcx.fn_sig(callee_def_id).skip_binder();
+ if let Some(i) = call_args.iter().position(|arg| arg.hir_id == maybe_arg.hir_id);
+ if let Some(input) = fn_sig.inputs().get(i);
+ let (input, n_refs) = peel_mid_ty_refs(*input);
+ if let (trait_predicates, projection_predicates) = get_input_traits_and_projections(cx, callee_def_id, input);
+ if let Some(sized_def_id) = cx.tcx.lang_items().sized_trait();
+ if let [trait_predicate] = trait_predicates
+ .iter()
+ .filter(|trait_predicate| trait_predicate.def_id() != sized_def_id)
+ .collect::<Vec<_>>()[..];
+ if let Some(deref_trait_id) = cx.tcx.get_diagnostic_item(sym::Deref);
+ if let Some(as_ref_trait_id) = cx.tcx.get_diagnostic_item(sym::AsRef);
+ let receiver_ty = cx.typeck_results().expr_ty(receiver);
+ // If the callee has type parameters, they could appear in `projection_predicate.ty` or the
+ // types of `trait_predicate.trait_ref.substs`.
+ if if trait_predicate.def_id() == deref_trait_id {
+ if let [projection_predicate] = projection_predicates[..] {
+ let normalized_ty =
+ cx.tcx
+ .subst_and_normalize_erasing_regions(call_substs, cx.param_env, projection_predicate.term);
+ implements_trait(cx, receiver_ty, deref_trait_id, &[])
+ && get_associated_type(cx, receiver_ty, deref_trait_id, "Target")
+ .map_or(false, |ty| ty::Term::Ty(ty) == normalized_ty)
+ } else {
+ false
+ }
+ } else if trait_predicate.def_id() == as_ref_trait_id {
+ let composed_substs = compose_substs(
+ cx,
+ &trait_predicate.trait_ref.substs.iter().skip(1).collect::<Vec<_>>()[..],
+ call_substs,
+ );
+ implements_trait(cx, receiver_ty, as_ref_trait_id, &composed_substs)
+ } else {
+ false
+ };
+ // We can't add an `&` when the trait is `Deref` because `Target = &T` won't match
+ // `Target = T`.
+ if n_refs > 0 || is_copy(cx, receiver_ty) || trait_predicate.def_id() != deref_trait_id;
+ let n_refs = max(n_refs, if is_copy(cx, receiver_ty) { 0 } else { 1 });
+ // If the trait is `AsRef` and the input type variable `T` occurs in the output type, then
+ // `T` must not be instantiated with a reference
+ // (https://github.com/rust-lang/rust-clippy/issues/8507).
+ if (n_refs == 0 && !receiver_ty.is_ref())
+ || trait_predicate.def_id() != as_ref_trait_id
+ || !contains_ty(fn_sig.output(), input);
+ if let Some(receiver_snippet) = snippet_opt(cx, receiver.span);
+ then {
+ span_lint_and_sugg(
+ cx,
+ UNNECESSARY_TO_OWNED,
+ maybe_arg.span,
+ &format!("unnecessary use of `{}`", method_name),
+ "use",
+ format!("{:&>width$}{}", "", receiver_snippet, width = n_refs),
+ Applicability::MachineApplicable,
+ );
+ return true;
+ }
+ }
+ false
+}
+
+/// Walks an expression's ancestors until it finds a non-`AddrOf` expression. Returns the first such
+/// expression found (if any) along with the immediately prior expression.
+fn skip_addr_of_ancestors<'tcx>(
+ cx: &LateContext<'tcx>,
+ mut expr: &'tcx Expr<'tcx>,
+) -> Option<(&'tcx Expr<'tcx>, &'tcx Expr<'tcx>)> {
+ while let Some(parent) = get_parent_expr(cx, expr) {
+ if let ExprKind::AddrOf(BorrowKind::Ref, Mutability::Not, _) = parent.kind {
+ expr = parent;
+ } else {
+ return Some((parent, expr));
+ }
+ }
+ None
+}
+
+/// Checks whether an expression is a function or method call and, if so, returns its `DefId`,
+/// `Substs`, and arguments.
+fn get_callee_substs_and_args<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx Expr<'tcx>,
+) -> Option<(DefId, SubstsRef<'tcx>, &'tcx [Expr<'tcx>])> {
+ if_chain! {
+ if let ExprKind::Call(callee, args) = expr.kind;
+ let callee_ty = cx.typeck_results().expr_ty(callee);
+ if let ty::FnDef(callee_def_id, _) = callee_ty.kind();
+ then {
+ let substs = cx.typeck_results().node_substs(callee.hir_id);
+ return Some((*callee_def_id, substs, args));
+ }
+ }
+ if_chain! {
+ if let ExprKind::MethodCall(_, args, _) = expr.kind;
+ if let Some(method_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
+ then {
+ let substs = cx.typeck_results().node_substs(expr.hir_id);
+ return Some((method_def_id, substs, args));
+ }
+ }
+ None
+}
+
+/// Returns the `TraitPredicate`s and `ProjectionPredicate`s for a function's input type.
+fn get_input_traits_and_projections<'tcx>(
+ cx: &LateContext<'tcx>,
+ callee_def_id: DefId,
+ input: Ty<'tcx>,
+) -> (Vec<TraitPredicate<'tcx>>, Vec<ProjectionPredicate<'tcx>>) {
+ let mut trait_predicates = Vec::new();
+ let mut projection_predicates = Vec::new();
+ for (predicate, _) in cx.tcx.predicates_of(callee_def_id).predicates.iter() {
+ // `substs` should have 1 + n elements. The first is the type on the left hand side of an
+ // `as`. The remaining n are trait parameters.
+ let is_input_substs = |substs: SubstsRef<'tcx>| {
+ if_chain! {
+ if let Some(arg) = substs.iter().next();
+ if let GenericArgKind::Type(arg_ty) = arg.unpack();
+ if arg_ty == input;
+ then { true } else { false }
+ }
+ };
+ match predicate.kind().skip_binder() {
+ PredicateKind::Trait(trait_predicate) => {
+ if is_input_substs(trait_predicate.trait_ref.substs) {
+ trait_predicates.push(trait_predicate);
+ }
+ },
+ PredicateKind::Projection(projection_predicate) => {
+ if is_input_substs(projection_predicate.projection_ty.substs) {
+ projection_predicates.push(projection_predicate);
+ }
+ },
+ _ => {},
+ }
+ }
+ (trait_predicates, projection_predicates)
+}
+
+/// Composes two substitutions by applying the latter to the types of the former.
+fn compose_substs<'tcx>(
+ cx: &LateContext<'tcx>,
+ left: &[GenericArg<'tcx>],
+ right: SubstsRef<'tcx>,
+) -> Vec<GenericArg<'tcx>> {
+ left.iter()
+ .map(|arg| {
+ if let GenericArgKind::Type(arg_ty) = arg.unpack() {
+ let normalized_ty = cx.tcx.subst_and_normalize_erasing_regions(right, cx.param_env, arg_ty);
+ GenericArg::from(normalized_ty)
+ } else {
+ *arg
+ }
+ })
+ .collect()
+}
+
+/// Returns true if the named method is `Iterator::cloned` or `Iterator::copied`.
+fn is_cloned_or_copied(cx: &LateContext<'_>, method_name: Symbol, method_def_id: DefId) -> bool {
+ (method_name.as_str() == "cloned" || method_name.as_str() == "copied")
+ && is_diag_trait_item(cx, method_def_id, sym::Iterator)
+}
+
+/// Returns true if the named method can be used to convert the receiver to its "owned"
+/// representation.
+fn is_to_owned_like(cx: &LateContext<'_>, method_name: Symbol, method_def_id: DefId) -> bool {
++ is_clone_like(cx, method_name.as_str(), method_def_id)
+ || is_cow_into_owned(cx, method_name, method_def_id)
+ || is_to_string(cx, method_name, method_def_id)
+}
+
+/// Returns true if the named method is `Cow::into_owned`.
+fn is_cow_into_owned(cx: &LateContext<'_>, method_name: Symbol, method_def_id: DefId) -> bool {
+ method_name.as_str() == "into_owned" && is_diag_item_method(cx, method_def_id, sym::Cow)
+}
+
+/// Returns true if the named method is `ToString::to_string`.
+fn is_to_string(cx: &LateContext<'_>, method_name: Symbol, method_def_id: DefId) -> bool {
+ method_name.as_str() == "to_string" && is_diag_trait_item(cx, method_def_id, sym::ToString)
+}
--- /dev/null
- /// ```ignore
+use clippy_utils::consts::{constant_simple, Constant};
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::{match_trait_method, paths};
+use if_chain::if_chain;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
+use std::cmp::Ordering;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for expressions where `std::cmp::min` and `max` are
+ /// used to clamp values, but switched so that the result is constant.
+ ///
+ /// ### Why is this bad?
+ /// This is in all probability not the intended outcome. At
+ /// the least it hurts readability of the code.
+ ///
+ /// ### Example
- /// ```
- /// or
- /// ```ignore
++ /// ```rust,ignore
+ /// min(0, max(100, x))
++ ///
++ /// // or
++ ///
+ /// x.max(100).min(0)
+ /// ```
+ /// It will always be equal to `0`. Probably the author meant to clamp the value
+ /// between 0 and 100, but has erroneously swapped `min` and `max`.
+ #[clippy::version = "pre 1.29.0"]
+ pub MIN_MAX,
+ correctness,
+ "`min(_, max(_, _))` (or vice versa) with bounds clamping the result to a constant"
+}
+
+declare_lint_pass!(MinMaxPass => [MIN_MAX]);
+
+impl<'tcx> LateLintPass<'tcx> for MinMaxPass {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if let Some((outer_max, outer_c, oe)) = min_max(cx, expr) {
+ if let Some((inner_max, inner_c, ie)) = min_max(cx, oe) {
+ if outer_max == inner_max {
+ return;
+ }
+ match (
+ outer_max,
+ Constant::partial_cmp(cx.tcx, cx.typeck_results().expr_ty(ie), &outer_c, &inner_c),
+ ) {
+ (_, None) | (MinMax::Max, Some(Ordering::Less)) | (MinMax::Min, Some(Ordering::Greater)) => (),
+ _ => {
+ span_lint(
+ cx,
+ MIN_MAX,
+ expr.span,
+ "this `min`/`max` combination leads to constant result",
+ );
+ },
+ }
+ }
+ }
+ }
+}
+
+#[derive(PartialEq, Eq, Debug, Clone, Copy)]
+enum MinMax {
+ Min,
+ Max,
+}
+
+fn min_max<'a>(cx: &LateContext<'_>, expr: &'a Expr<'a>) -> Option<(MinMax, Constant, &'a Expr<'a>)> {
+ match expr.kind {
+ ExprKind::Call(path, args) => {
+ if let ExprKind::Path(ref qpath) = path.kind {
+ cx.typeck_results()
+ .qpath_res(qpath, path.hir_id)
+ .opt_def_id()
+ .and_then(|def_id| match cx.tcx.get_diagnostic_name(def_id) {
+ Some(sym::cmp_min) => fetch_const(cx, args, MinMax::Min),
+ Some(sym::cmp_max) => fetch_const(cx, args, MinMax::Max),
+ _ => None,
+ })
+ } else {
+ None
+ }
+ },
+ ExprKind::MethodCall(path, args, _) => {
+ if_chain! {
+ if let [obj, _] = args;
+ if cx.typeck_results().expr_ty(obj).is_floating_point() || match_trait_method(cx, expr, &paths::ORD);
+ then {
+ if path.ident.name == sym!(max) {
+ fetch_const(cx, args, MinMax::Max)
+ } else if path.ident.name == sym!(min) {
+ fetch_const(cx, args, MinMax::Min)
+ } else {
+ None
+ }
+ } else {
+ None
+ }
+ }
+ },
+ _ => None,
+ }
+}
+
+fn fetch_const<'a>(cx: &LateContext<'_>, args: &'a [Expr<'a>], m: MinMax) -> Option<(MinMax, Constant, &'a Expr<'a>)> {
+ if args.len() != 2 {
+ return None;
+ }
+ constant_simple(cx, cx.typeck_results(), &args[0]).map_or_else(
+ || constant_simple(cx, cx.typeck_results(), &args[1]).map(|c| (m, c, &args[0])),
+ |c| {
+ if constant_simple(cx, cx.typeck_results(), &args[1]).is_none() {
+ // otherwise ignore
+ Some((m, c, &args[1]))
+ } else {
+ None
+ }
+ },
+ )
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg, span_lint_and_then, span_lint_hir_and_then};
+use clippy_utils::source::{snippet, snippet_opt};
+use clippy_utils::ty::{implements_trait, is_copy};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::FnKind;
+use rustc_hir::{
+ self as hir, def, BinOpKind, BindingAnnotation, Body, Expr, ExprKind, FnDecl, HirId, Mutability, PatKind, Stmt,
+ StmtKind, TyKind, UnOp,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::hygiene::DesugaringKind;
+use rustc_span::source_map::{ExpnKind, Span};
+use rustc_span::symbol::sym;
+
+use clippy_utils::consts::{constant, Constant};
+use clippy_utils::sugg::Sugg;
+use clippy_utils::{
+ get_item_name, get_parent_expr, in_constant, is_integer_const, iter_input_pats, last_path_segment,
+ match_any_def_paths, path_def_id, paths, unsext, SpanlessEq,
+};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for function arguments and let bindings denoted as
+ /// `ref`.
+ ///
+ /// ### Why is this bad?
+ /// The `ref` declaration makes the function take an owned
+ /// value, but turns the argument into a reference (which means that the value
+ /// is destroyed when exiting the function). This adds not much value: either
+ /// take a reference type, or take an owned value and create references in the
+ /// body.
+ ///
+ /// For let bindings, `let x = &foo;` is preferred over `let ref x = foo`. The
+ /// type of `x` is more obvious with the former.
+ ///
+ /// ### Known problems
+ /// If the argument is dereferenced within the function,
+ /// removing the `ref` will lead to errors. This can be fixed by removing the
+ /// dereferences, e.g., changing `*x` to `x` within the function.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// // Bad
+ /// fn foo(ref x: u8) -> bool {
+ /// true
+ /// }
+ ///
+ /// // Good
+ /// fn foo(x: &u8) -> bool {
+ /// true
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub TOPLEVEL_REF_ARG,
+ style,
+ "an entire binding declared as `ref`, in a function argument or a `let` statement"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for comparisons to NaN.
+ ///
+ /// ### Why is this bad?
+ /// NaN does not compare meaningfully to anything – not
+ /// even itself – so those comparisons are simply wrong.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let x = 1.0;
+ ///
+ /// // Bad
+ /// if x == f32::NAN { }
+ ///
+ /// // Good
+ /// if x.is_nan() { }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CMP_NAN,
+ correctness,
+ "comparisons to `NAN`, which will always return false, probably not intended"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for (in-)equality comparisons on floating-point
+ /// values (apart from zero), except in functions called `*eq*` (which probably
+ /// implement equality for a type involving floats).
+ ///
+ /// ### Why is this bad?
+ /// Floating point calculations are usually imprecise, so
+ /// asking if two values are *exactly* equal is asking for trouble. For a good
+ /// guide on what to do, see [the floating point
+ /// guide](http://www.floating-point-gui.de/errors/comparison).
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = 1.2331f64;
+ /// let y = 1.2332f64;
+ ///
- /// // Good
+ /// if y == 1.23f64 { }
+ /// if y != x {} // where both are floats
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # let x = 1.2331f64;
++ /// # let y = 1.2332f64;
+ /// let error_margin = f64::EPSILON; // Use an epsilon for comparison
+ /// // Or, if Rust <= 1.42, use `std::f64::EPSILON` constant instead.
+ /// // let error_margin = std::f64::EPSILON;
+ /// if (y - 1.23f64).abs() < error_margin { }
+ /// if (y - x).abs() > error_margin { }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub FLOAT_CMP,
+ pedantic,
+ "using `==` or `!=` on float values instead of comparing difference with an epsilon"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for conversions to owned values just for the sake
+ /// of a comparison.
+ ///
+ /// ### Why is this bad?
+ /// The comparison can operate on a reference, so creating
+ /// an owned value effectively throws it away directly afterwards, which is
+ /// needlessly consuming code and heap space.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let x = "foo";
+ /// # let y = String::from("foo");
+ /// if x.to_owned() == y {}
+ /// ```
+ /// Could be written as
+ /// ```rust
+ /// # let x = "foo";
+ /// # let y = String::from("foo");
+ /// if x == y {}
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CMP_OWNED,
+ perf,
+ "creating owned instances for comparing with others, e.g., `x == \"foo\".to_string()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for getting the remainder of a division by one or minus
+ /// one.
+ ///
+ /// ### Why is this bad?
+ /// The result for a divisor of one can only ever be zero; for
+ /// minus one it can cause panic/overflow (if the left operand is the minimal value of
+ /// the respective integer type) or results in zero. No one will write such code
+ /// deliberately, unless trying to win an Underhanded Rust Contest. Even for that
+ /// contest, it's probably a bad idea. Use something more underhanded.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let x = 1;
+ /// let a = x % 1;
+ /// let a = x % -1;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MODULO_ONE,
+ correctness,
+ "taking a number modulo +/-1, which can either panic/overflow or always returns 0"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the use of bindings with a single leading
+ /// underscore.
+ ///
+ /// ### Why is this bad?
+ /// A single leading underscore is usually used to indicate
+ /// that a binding will not be used. Using such a binding breaks this
+ /// expectation.
+ ///
+ /// ### Known problems
+ /// The lint does not work properly with desugaring and
+ /// macro, it has been allowed in the mean time.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let _x = 0;
+ /// let y = _x + 1; // Here we are using `_x`, even though it has a leading
+ /// // underscore. We should rename `_x` to `x`
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub USED_UNDERSCORE_BINDING,
+ pedantic,
+ "using a binding which is prefixed with an underscore"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the use of short circuit boolean conditions as
+ /// a
+ /// statement.
+ ///
+ /// ### Why is this bad?
+ /// Using a short circuit boolean condition as a statement
+ /// may hide the fact that the second part is executed or not depending on the
+ /// outcome of the first part.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// f() && g(); // We should write `if f() { g(); }`.
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub SHORT_CIRCUIT_STATEMENT,
+ complexity,
+ "using a short circuit boolean condition as a statement"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Catch casts from `0` to some pointer type
+ ///
+ /// ### Why is this bad?
+ /// This generally means `null` and is better expressed as
+ /// {`std`, `core`}`::ptr::`{`null`, `null_mut`}.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// let a = 0 as *const u32;
+ ///
+ /// // Good
+ /// let a = std::ptr::null::<u32>();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ZERO_PTR,
+ style,
+ "using `0 as *{const, mut} T`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for (in-)equality comparisons on floating-point
+ /// value and constant, except in functions called `*eq*` (which probably
+ /// implement equality for a type involving floats).
+ ///
+ /// ### Why is this bad?
+ /// Floating point calculations are usually imprecise, so
+ /// asking if two values are *exactly* equal is asking for trouble. For a good
+ /// guide on what to do, see [the floating point
+ /// guide](http://www.floating-point-gui.de/errors/comparison).
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x: f64 = 1.0;
+ /// const ONE: f64 = 1.00;
+ ///
- /// // Good
+ /// if x == ONE { } // where both are floats
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # let x: f64 = 1.0;
++ /// # const ONE: f64 = 1.00;
+ /// let error_margin = f64::EPSILON; // Use an epsilon for comparison
+ /// // Or, if Rust <= 1.42, use `std::f64::EPSILON` constant instead.
+ /// // let error_margin = std::f64::EPSILON;
+ /// if (x - ONE).abs() < error_margin { }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub FLOAT_CMP_CONST,
+ restriction,
+ "using `==` or `!=` on float constants instead of comparing difference with an epsilon"
+}
+
+declare_lint_pass!(MiscLints => [
+ TOPLEVEL_REF_ARG,
+ CMP_NAN,
+ FLOAT_CMP,
+ CMP_OWNED,
+ MODULO_ONE,
+ USED_UNDERSCORE_BINDING,
+ SHORT_CIRCUIT_STATEMENT,
+ ZERO_PTR,
+ FLOAT_CMP_CONST
+]);
+
+impl<'tcx> LateLintPass<'tcx> for MiscLints {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ k: FnKind<'tcx>,
+ decl: &'tcx FnDecl<'_>,
+ body: &'tcx Body<'_>,
+ span: Span,
+ _: HirId,
+ ) {
+ if let FnKind::Closure = k {
+ // Does not apply to closures
+ return;
+ }
+ if in_external_macro(cx.tcx.sess, span) {
+ return;
+ }
+ for arg in iter_input_pats(decl, body) {
+ if let PatKind::Binding(BindingAnnotation::Ref | BindingAnnotation::RefMut, ..) = arg.pat.kind {
+ span_lint(
+ cx,
+ TOPLEVEL_REF_ARG,
+ arg.pat.span,
+ "`ref` directly on a function argument is ignored. \
+ Consider using a reference type instead",
+ );
+ }
+ }
+ }
+
+ fn check_stmt(&mut self, cx: &LateContext<'tcx>, stmt: &'tcx Stmt<'_>) {
+ if_chain! {
+ if !in_external_macro(cx.tcx.sess, stmt.span);
+ if let StmtKind::Local(local) = stmt.kind;
+ if let PatKind::Binding(an, .., name, None) = local.pat.kind;
+ if let Some(init) = local.init;
+ if an == BindingAnnotation::Ref || an == BindingAnnotation::RefMut;
+ then {
+ // use the macro callsite when the init span (but not the whole local span)
+ // comes from an expansion like `vec![1, 2, 3]` in `let ref _ = vec![1, 2, 3];`
+ let sugg_init = if init.span.from_expansion() && !local.span.from_expansion() {
+ Sugg::hir_with_macro_callsite(cx, init, "..")
+ } else {
+ Sugg::hir(cx, init, "..")
+ };
+ let (mutopt, initref) = if an == BindingAnnotation::RefMut {
+ ("mut ", sugg_init.mut_addr())
+ } else {
+ ("", sugg_init.addr())
+ };
+ let tyopt = if let Some(ty) = local.ty {
+ format!(": &{mutopt}{ty}", mutopt=mutopt, ty=snippet(cx, ty.span, ".."))
+ } else {
+ String::new()
+ };
+ span_lint_hir_and_then(
+ cx,
+ TOPLEVEL_REF_ARG,
+ init.hir_id,
+ local.pat.span,
+ "`ref` on an entire `let` pattern is discouraged, take a reference with `&` instead",
+ |diag| {
+ diag.span_suggestion(
+ stmt.span,
+ "try",
+ format!(
+ "let {name}{tyopt} = {initref};",
+ name=snippet(cx, name.span, ".."),
+ tyopt=tyopt,
+ initref=initref,
+ ),
+ Applicability::MachineApplicable,
+ );
+ }
+ );
+ }
+ };
+ if_chain! {
+ if let StmtKind::Semi(expr) = stmt.kind;
+ if let ExprKind::Binary(ref binop, a, b) = expr.kind;
+ if binop.node == BinOpKind::And || binop.node == BinOpKind::Or;
+ if let Some(sugg) = Sugg::hir_opt(cx, a);
+ then {
+ span_lint_hir_and_then(
+ cx,
+ SHORT_CIRCUIT_STATEMENT,
+ expr.hir_id,
+ stmt.span,
+ "boolean short circuit operator in statement may be clearer using an explicit test",
+ |diag| {
+ let sugg = if binop.node == BinOpKind::Or { !sugg } else { sugg };
+ diag.span_suggestion(
+ stmt.span,
+ "replace it with",
+ format!(
+ "if {} {{ {}; }}",
+ sugg,
+ &snippet(cx, b.span, ".."),
+ ),
+ Applicability::MachineApplicable, // snippet
+ );
+ });
+ }
+ };
+ }
+
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ match expr.kind {
+ ExprKind::Cast(e, ty) => {
+ check_cast(cx, expr.span, e, ty);
+ return;
+ },
+ ExprKind::Binary(ref cmp, left, right) => {
+ check_binary(cx, expr, cmp, left, right);
+ return;
+ },
+ _ => {},
+ }
+ if in_attributes_expansion(expr) || expr.span.is_desugaring(DesugaringKind::Await) {
+ // Don't lint things expanded by #[derive(...)], etc or `await` desugaring
+ return;
+ }
+ let sym;
+ let binding = match expr.kind {
+ ExprKind::Path(ref qpath) if !matches!(qpath, hir::QPath::LangItem(..)) => {
+ let binding = last_path_segment(qpath).ident.as_str();
+ if binding.starts_with('_') &&
+ !binding.starts_with("__") &&
+ binding != "_result" && // FIXME: #944
+ is_used(cx, expr) &&
+ // don't lint if the declaration is in a macro
+ non_macro_local(cx, cx.qpath_res(qpath, expr.hir_id))
+ {
+ Some(binding)
+ } else {
+ None
+ }
+ },
+ ExprKind::Field(_, ident) => {
+ sym = ident.name;
+ let name = sym.as_str();
+ if name.starts_with('_') && !name.starts_with("__") {
+ Some(name)
+ } else {
+ None
+ }
+ },
+ _ => None,
+ };
+ if let Some(binding) = binding {
+ span_lint(
+ cx,
+ USED_UNDERSCORE_BINDING,
+ expr.span,
+ &format!(
+ "used binding `{}` which is prefixed with an underscore. A leading \
+ underscore signals that a binding will not be used",
+ binding
+ ),
+ );
+ }
+ }
+}
+
+fn get_lint_and_message(
+ is_comparing_constants: bool,
+ is_comparing_arrays: bool,
+) -> (&'static rustc_lint::Lint, &'static str) {
+ if is_comparing_constants {
+ (
+ FLOAT_CMP_CONST,
+ if is_comparing_arrays {
+ "strict comparison of `f32` or `f64` constant arrays"
+ } else {
+ "strict comparison of `f32` or `f64` constant"
+ },
+ )
+ } else {
+ (
+ FLOAT_CMP,
+ if is_comparing_arrays {
+ "strict comparison of `f32` or `f64` arrays"
+ } else {
+ "strict comparison of `f32` or `f64`"
+ },
+ )
+ }
+}
+
+fn check_nan(cx: &LateContext<'_>, expr: &Expr<'_>, cmp_expr: &Expr<'_>) {
+ if_chain! {
+ if !in_constant(cx, cmp_expr.hir_id);
+ if let Some((value, _)) = constant(cx, cx.typeck_results(), expr);
+ if match value {
+ Constant::F32(num) => num.is_nan(),
+ Constant::F64(num) => num.is_nan(),
+ _ => false,
+ };
+ then {
+ span_lint(
+ cx,
+ CMP_NAN,
+ cmp_expr.span,
+ "doomed comparison with `NAN`, use `{f32,f64}::is_nan()` instead",
+ );
+ }
+ }
+}
+
+fn is_named_constant<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> bool {
+ if let Some((_, res)) = constant(cx, cx.typeck_results(), expr) {
+ res
+ } else {
+ false
+ }
+}
+
+fn is_allowed<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> bool {
+ match constant(cx, cx.typeck_results(), expr) {
+ Some((Constant::F32(f), _)) => f == 0.0 || f.is_infinite(),
+ Some((Constant::F64(f), _)) => f == 0.0 || f.is_infinite(),
+ Some((Constant::Vec(vec), _)) => vec.iter().all(|f| match f {
+ Constant::F32(f) => *f == 0.0 || (*f).is_infinite(),
+ Constant::F64(f) => *f == 0.0 || (*f).is_infinite(),
+ _ => false,
+ }),
+ _ => false,
+ }
+}
+
+// Return true if `expr` is the result of `signum()` invoked on a float value.
+fn is_signum(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ // The negation of a signum is still a signum
+ if let ExprKind::Unary(UnOp::Neg, child_expr) = expr.kind {
+ return is_signum(cx, child_expr);
+ }
+
+ if_chain! {
+ if let ExprKind::MethodCall(method_name, [ref self_arg, ..], _) = expr.kind;
+ if sym!(signum) == method_name.ident.name;
+ // Check that the receiver of the signum() is a float (expressions[0] is the receiver of
+ // the method call)
+ then {
+ return is_float(cx, self_arg);
+ }
+ }
+ false
+}
+
+fn is_float(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ let value = &cx.typeck_results().expr_ty(expr).peel_refs().kind();
+
+ if let ty::Array(arr_ty, _) = value {
+ return matches!(arr_ty.kind(), ty::Float(_));
+ };
+
+ matches!(value, ty::Float(_))
+}
+
+fn is_array(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ matches!(&cx.typeck_results().expr_ty(expr).peel_refs().kind(), ty::Array(_, _))
+}
+
+#[expect(clippy::too_many_lines)]
+fn check_to_owned(cx: &LateContext<'_>, expr: &Expr<'_>, other: &Expr<'_>, left: bool) {
+ #[derive(Default)]
+ struct EqImpl {
+ ty_eq_other: bool,
+ other_eq_ty: bool,
+ }
+
+ impl EqImpl {
+ fn is_implemented(&self) -> bool {
+ self.ty_eq_other || self.other_eq_ty
+ }
+ }
+
+ fn symmetric_partial_eq<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, other: Ty<'tcx>) -> Option<EqImpl> {
+ cx.tcx.lang_items().eq_trait().map(|def_id| EqImpl {
+ ty_eq_other: implements_trait(cx, ty, def_id, &[other.into()]),
+ other_eq_ty: implements_trait(cx, other, def_id, &[ty.into()]),
+ })
+ }
+
+ let typeck = cx.typeck_results();
+ let (arg, arg_span) = match expr.kind {
+ ExprKind::MethodCall(.., [arg], _)
+ if typeck
+ .type_dependent_def_id(expr.hir_id)
+ .and_then(|id| cx.tcx.trait_of_item(id))
+ .map_or(false, |id| {
+ matches!(cx.tcx.get_diagnostic_name(id), Some(sym::ToString | sym::ToOwned))
+ }) =>
+ {
+ (arg, arg.span)
+ },
+ ExprKind::Call(path, [arg])
+ if path_def_id(cx, path)
+ .and_then(|id| match_any_def_paths(cx, id, &[&paths::FROM_STR_METHOD, &paths::FROM_FROM]))
+ .map_or(false, |idx| match idx {
+ 0 => true,
+ 1 => !is_copy(cx, typeck.expr_ty(expr)),
+ _ => false,
+ }) =>
+ {
+ (arg, arg.span)
+ },
+ _ => return,
+ };
+
+ let arg_ty = typeck.expr_ty(arg);
+ let other_ty = typeck.expr_ty(other);
+
+ let without_deref = symmetric_partial_eq(cx, arg_ty, other_ty).unwrap_or_default();
+ let with_deref = arg_ty
+ .builtin_deref(true)
+ .and_then(|tam| symmetric_partial_eq(cx, tam.ty, other_ty))
+ .unwrap_or_default();
+
+ if !with_deref.is_implemented() && !without_deref.is_implemented() {
+ return;
+ }
+
+ let other_gets_derefed = matches!(other.kind, ExprKind::Unary(UnOp::Deref, _));
+
+ let lint_span = if other_gets_derefed {
+ expr.span.to(other.span)
+ } else {
+ expr.span
+ };
+
+ span_lint_and_then(
+ cx,
+ CMP_OWNED,
+ lint_span,
+ "this creates an owned instance just for comparison",
+ |diag| {
+ // This also catches `PartialEq` implementations that call `to_owned`.
+ if other_gets_derefed {
+ diag.span_label(lint_span, "try implementing the comparison without allocating");
+ return;
+ }
+
+ let arg_snip = snippet(cx, arg_span, "..");
+ let expr_snip;
+ let eq_impl;
+ if with_deref.is_implemented() {
+ expr_snip = format!("*{}", arg_snip);
+ eq_impl = with_deref;
+ } else {
+ expr_snip = arg_snip.to_string();
+ eq_impl = without_deref;
+ };
+
+ let span;
+ let hint;
+ if (eq_impl.ty_eq_other && left) || (eq_impl.other_eq_ty && !left) {
+ span = expr.span;
+ hint = expr_snip;
+ } else {
+ span = expr.span.to(other.span);
+
+ let cmp_span = if other.span < expr.span {
+ other.span.between(expr.span)
+ } else {
+ expr.span.between(other.span)
+ };
+ if eq_impl.ty_eq_other {
+ hint = format!(
+ "{}{}{}",
+ expr_snip,
+ snippet(cx, cmp_span, ".."),
+ snippet(cx, other.span, "..")
+ );
+ } else {
+ hint = format!(
+ "{}{}{}",
+ snippet(cx, other.span, ".."),
+ snippet(cx, cmp_span, ".."),
+ expr_snip
+ );
+ }
+ }
+
+ diag.span_suggestion(
+ span,
+ "try",
+ hint,
+ Applicability::MachineApplicable, // snippet
+ );
+ },
+ );
+}
+
+/// Heuristic to see if an expression is used. Should be compatible with
+/// `unused_variables`'s idea
+/// of what it means for an expression to be "used".
+fn is_used(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ get_parent_expr(cx, expr).map_or(true, |parent| match parent.kind {
+ ExprKind::Assign(_, rhs, _) | ExprKind::AssignOp(_, _, rhs) => SpanlessEq::new(cx).eq_expr(rhs, expr),
+ _ => is_used(cx, parent),
+ })
+}
+
+/// Tests whether an expression is in a macro expansion (e.g., something
+/// generated by `#[derive(...)]` or the like).
+fn in_attributes_expansion(expr: &Expr<'_>) -> bool {
+ use rustc_span::hygiene::MacroKind;
+ if expr.span.from_expansion() {
+ let data = expr.span.ctxt().outer_expn_data();
+ matches!(data.kind, ExpnKind::Macro(MacroKind::Attr, _))
+ } else {
+ false
+ }
+}
+
+/// Tests whether `res` is a variable defined outside a macro.
+fn non_macro_local(cx: &LateContext<'_>, res: def::Res) -> bool {
+ if let def::Res::Local(id) = res {
+ !cx.tcx.hir().span(id).from_expansion()
+ } else {
+ false
+ }
+}
+
+fn check_cast(cx: &LateContext<'_>, span: Span, e: &Expr<'_>, ty: &hir::Ty<'_>) {
+ if_chain! {
+ if let TyKind::Ptr(ref mut_ty) = ty.kind;
+ if let ExprKind::Lit(ref lit) = e.kind;
+ if let LitKind::Int(0, _) = lit.node;
+ if !in_constant(cx, e.hir_id);
+ then {
+ let (msg, sugg_fn) = match mut_ty.mutbl {
+ Mutability::Mut => ("`0 as *mut _` detected", "std::ptr::null_mut"),
+ Mutability::Not => ("`0 as *const _` detected", "std::ptr::null"),
+ };
+
+ let (sugg, appl) = if let TyKind::Infer = mut_ty.ty.kind {
+ (format!("{}()", sugg_fn), Applicability::MachineApplicable)
+ } else if let Some(mut_ty_snip) = snippet_opt(cx, mut_ty.ty.span) {
+ (format!("{}::<{}>()", sugg_fn, mut_ty_snip), Applicability::MachineApplicable)
+ } else {
+ // `MaybeIncorrect` as type inference may not work with the suggested code
+ (format!("{}()", sugg_fn), Applicability::MaybeIncorrect)
+ };
+ span_lint_and_sugg(cx, ZERO_PTR, span, msg, "try", sugg, appl);
+ }
+ }
+}
+
+fn check_binary<'a>(
+ cx: &LateContext<'a>,
+ expr: &Expr<'_>,
+ cmp: &rustc_span::source_map::Spanned<rustc_hir::BinOpKind>,
+ left: &'a Expr<'_>,
+ right: &'a Expr<'_>,
+) {
+ let op = cmp.node;
+ if op.is_comparison() {
+ check_nan(cx, left, expr);
+ check_nan(cx, right, expr);
+ check_to_owned(cx, left, right, true);
+ check_to_owned(cx, right, left, false);
+ }
+ if (op == BinOpKind::Eq || op == BinOpKind::Ne) && (is_float(cx, left) || is_float(cx, right)) {
+ if is_allowed(cx, left) || is_allowed(cx, right) {
+ return;
+ }
+
+ // Allow comparing the results of signum()
+ if is_signum(cx, left) && is_signum(cx, right) {
+ return;
+ }
+
+ if let Some(name) = get_item_name(cx, expr) {
+ let name = name.as_str();
+ if name == "eq" || name == "ne" || name == "is_nan" || name.starts_with("eq_") || name.ends_with("_eq") {
+ return;
+ }
+ }
+ let is_comparing_arrays = is_array(cx, left) || is_array(cx, right);
+ let (lint, msg) = get_lint_and_message(
+ is_named_constant(cx, left) || is_named_constant(cx, right),
+ is_comparing_arrays,
+ );
+ span_lint_and_then(cx, lint, expr.span, msg, |diag| {
+ let lhs = Sugg::hir(cx, left, "..");
+ let rhs = Sugg::hir(cx, right, "..");
+
+ if !is_comparing_arrays {
+ diag.span_suggestion(
+ expr.span,
+ "consider comparing them within some margin of error",
+ format!(
+ "({}).abs() {} error_margin",
+ lhs - rhs,
+ if op == BinOpKind::Eq { '<' } else { '>' }
+ ),
+ Applicability::HasPlaceholders, // snippet
+ );
+ }
+ diag.note("`f32::EPSILON` and `f64::EPSILON` are available for the `error_margin`");
+ });
+ } else if op == BinOpKind::Rem {
+ if is_integer_const(cx, right, 1) {
+ span_lint(cx, MODULO_ONE, expr.span, "any number modulo 1 will be 0");
+ }
+
+ if let ty::Int(ity) = cx.typeck_results().expr_ty(right).kind() {
+ if is_integer_const(cx, right, unsext(cx.tcx, -1, *ity)) {
+ span_lint(
+ cx,
+ MODULO_ONE,
+ expr.span,
+ "any number modulo -1 will panic/overflow or result in 0",
+ );
+ }
+ };
+ }
+}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint_and_help;
++use rustc_data_structures::fx::FxHashMap;
++use rustc_hir::def::{DefKind, Res};
++use rustc_hir::{GenericArg, Item, ItemKind, QPath, Ty, TyKind};
++use rustc_lint::{LateContext, LateLintPass};
++use rustc_middle::ty::GenericParamDefKind;
++use rustc_session::{declare_lint_pass, declare_tool_lint};
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for type parameters which are positioned inconsistently between
++ /// a type definition and impl block. Specifically, a paramater in an impl
++ /// block which has the same name as a parameter in the type def, but is in
++ /// a different place.
++ ///
++ /// ### Why is this bad?
++ /// Type parameters are determined by their position rather than name.
++ /// Naming type parameters inconsistently may cause you to refer to the
++ /// wrong type parameter.
++ ///
++ /// ### Example
++ /// ```rust
++ /// struct Foo<A, B> {
++ /// x: A,
++ /// y: B,
++ /// }
++ /// // inside the impl, B refers to Foo::A
++ /// impl<B, A> Foo<B, A> {}
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// struct Foo<A, B> {
++ /// x: A,
++ /// y: B,
++ /// }
++ /// impl<A, B> Foo<A, B> {}
++ /// ```
++ #[clippy::version = "1.62.0"]
++ pub MISMATCHING_TYPE_PARAM_ORDER,
++ pedantic,
++ "type parameter positioned inconsistently between type def and impl block"
++}
++declare_lint_pass!(TypeParamMismatch => [MISMATCHING_TYPE_PARAM_ORDER]);
++
++impl<'tcx> LateLintPass<'tcx> for TypeParamMismatch {
++ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) {
++ if_chain! {
++ if !item.span.from_expansion();
++ if let ItemKind::Impl(imp) = &item.kind;
++ if let TyKind::Path(QPath::Resolved(_, path)) = &imp.self_ty.kind;
++ if let Some(segment) = path.segments.iter().next();
++ if let Some(generic_args) = segment.args;
++ if !generic_args.args.is_empty();
++ then {
++ // get the name and span of the generic parameters in the Impl
++ let impl_params = generic_args.args.iter()
++ .filter_map(|p|
++ match p {
++ GenericArg::Type(Ty {kind: TyKind::Path(QPath::Resolved(_, path)), ..}) =>
++ Some((path.segments[0].ident.to_string(), path.span)),
++ _ => None,
++ }
++ );
++
++ // find the type that the Impl is for
++ // only lint on struct/enum/union for now
++ let defid = match path.res {
++ Res::Def(DefKind::Struct | DefKind::Enum | DefKind::Union, defid) => defid,
++ _ => return,
++ };
++
++ // get the names of the generic parameters in the type
++ let type_params = &cx.tcx.generics_of(defid).params;
++ let type_param_names: Vec<_> = type_params.iter()
++ .filter_map(|p|
++ match p.kind {
++ GenericParamDefKind::Type {..} => Some(p.name.to_string()),
++ _ => None,
++ }
++ ).collect();
++ // hashmap of name -> index for mismatch_param_name
++ let type_param_names_hashmap: FxHashMap<&String, usize> =
++ type_param_names.iter().enumerate().map(|(i, param)| (param, i)).collect();
++
++ let type_name = segment.ident;
++ for (i, (impl_param_name, impl_param_span)) in impl_params.enumerate() {
++ if mismatch_param_name(i, &impl_param_name, &type_param_names_hashmap) {
++ let msg = format!("`{}` has a similarly named generic type parameter `{}` in its declaration, but in a different order",
++ type_name, impl_param_name);
++ let help = format!("try `{}`, or a name that does not conflict with `{}`'s generic params",
++ type_param_names[i], type_name);
++ span_lint_and_help(
++ cx,
++ MISMATCHING_TYPE_PARAM_ORDER,
++ impl_param_span,
++ &msg,
++ None,
++ &help
++ );
++ }
++ }
++ }
++ }
++ }
++}
++
++// Checks if impl_param_name is the same as one of type_param_names,
++// and is in a different position
++fn mismatch_param_name(i: usize, impl_param_name: &String, type_param_names: &FxHashMap<&String, usize>) -> bool {
++ if let Some(j) = type_param_names.get(impl_param_name) {
++ if i != *j {
++ return true;
++ }
++ }
++ false
++}
--- /dev/null
- self.maybe_walk_expr(&*arm.body);
+use clippy_utils::diagnostics::{span_lint, span_lint_and_note};
+use clippy_utils::{get_parent_expr, path_to_local, path_to_local_id};
+use if_chain::if_chain;
+use rustc_hir::intravisit::{walk_expr, Visitor};
+use rustc_hir::{BinOpKind, Block, Expr, ExprKind, Guard, HirId, Local, Node, Stmt, StmtKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for a read and a write to the same variable where
+ /// whether the read occurs before or after the write depends on the evaluation
+ /// order of sub-expressions.
+ ///
+ /// ### Why is this bad?
+ /// It is often confusing to read. As described [here](https://doc.rust-lang.org/reference/expressions.html?highlight=subexpression#evaluation-order-of-operands),
+ /// the operands of these expressions are evaluated before applying the effects of the expression.
+ ///
+ /// ### Known problems
+ /// Code which intentionally depends on the evaluation
+ /// order, or which is correct for any evaluation order.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let mut x = 0;
+ ///
+ /// // Bad
+ /// let a = {
+ /// x = 1;
+ /// 1
+ /// } + x;
+ /// // Unclear whether a is 1 or 2.
+ ///
+ /// // Good
+ /// let tmp = {
+ /// x = 1;
+ /// 1
+ /// };
+ /// let a = tmp + x;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MIXED_READ_WRITE_IN_EXPRESSION,
+ restriction,
+ "whether a variable read occurs before a write depends on sub-expression evaluation order"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for diverging calls that are not match arms or
+ /// statements.
+ ///
+ /// ### Why is this bad?
+ /// It is often confusing to read. In addition, the
+ /// sub-expression evaluation order for Rust is not well documented.
+ ///
+ /// ### Known problems
+ /// Someone might want to use `some_bool || panic!()` as a
+ /// shorthand.
+ ///
+ /// ### Example
+ /// ```rust,no_run
+ /// # fn b() -> bool { true }
+ /// # fn c() -> bool { true }
+ /// let a = b() || panic!() || c();
+ /// // `c()` is dead, `panic!()` is only called if `b()` returns `false`
+ /// let x = (a, b, c, panic!());
+ /// // can simply be replaced by `panic!()`
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DIVERGING_SUB_EXPRESSION,
+ complexity,
+ "whether an expression contains a diverging sub expression"
+}
+
+declare_lint_pass!(EvalOrderDependence => [MIXED_READ_WRITE_IN_EXPRESSION, DIVERGING_SUB_EXPRESSION]);
+
+impl<'tcx> LateLintPass<'tcx> for EvalOrderDependence {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ // Find a write to a local variable.
+ let var = if_chain! {
+ if let ExprKind::Assign(lhs, ..) | ExprKind::AssignOp(_, lhs, _) = expr.kind;
+ if let Some(var) = path_to_local(lhs);
+ if expr.span.desugaring_kind().is_none();
+ then { var } else { return; }
+ };
+ let mut visitor = ReadVisitor {
+ cx,
+ var,
+ write_expr: expr,
+ last_expr: expr,
+ };
+ check_for_unsequenced_reads(&mut visitor);
+ }
+ fn check_stmt(&mut self, cx: &LateContext<'tcx>, stmt: &'tcx Stmt<'_>) {
+ match stmt.kind {
+ StmtKind::Local(local) => {
+ if let Local { init: Some(e), .. } = local {
+ DivergenceVisitor { cx }.visit_expr(e);
+ }
+ },
+ StmtKind::Expr(e) | StmtKind::Semi(e) => DivergenceVisitor { cx }.maybe_walk_expr(e),
+ StmtKind::Item(..) => {},
+ }
+ }
+}
+
+struct DivergenceVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+}
+
+impl<'a, 'tcx> DivergenceVisitor<'a, 'tcx> {
+ fn maybe_walk_expr(&mut self, e: &'tcx Expr<'_>) {
+ match e.kind {
+ ExprKind::Closure(..) => {},
+ ExprKind::Match(e, arms, _) => {
+ self.visit_expr(e);
+ for arm in arms {
+ if let Some(Guard::If(if_expr)) = arm.guard {
+ self.visit_expr(if_expr);
+ }
+ // make sure top level arm expressions aren't linted
++ self.maybe_walk_expr(arm.body);
+ }
+ },
+ _ => walk_expr(self, e),
+ }
+ }
+ fn report_diverging_sub_expr(&mut self, e: &Expr<'_>) {
+ span_lint(self.cx, DIVERGING_SUB_EXPRESSION, e.span, "sub-expression diverges");
+ }
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for DivergenceVisitor<'a, 'tcx> {
+ fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
+ match e.kind {
+ ExprKind::Continue(_) | ExprKind::Break(_, _) | ExprKind::Ret(_) => self.report_diverging_sub_expr(e),
+ ExprKind::Call(func, _) => {
+ let typ = self.cx.typeck_results().expr_ty(func);
+ match typ.kind() {
+ ty::FnDef(..) | ty::FnPtr(_) => {
+ let sig = typ.fn_sig(self.cx.tcx);
+ if self.cx.tcx.erase_late_bound_regions(sig).output().kind() == &ty::Never {
+ self.report_diverging_sub_expr(e);
+ }
+ },
+ _ => {},
+ }
+ },
+ ExprKind::MethodCall(..) => {
+ let borrowed_table = self.cx.typeck_results();
+ if borrowed_table.expr_ty(e).is_never() {
+ self.report_diverging_sub_expr(e);
+ }
+ },
+ _ => {
+ // do not lint expressions referencing objects of type `!`, as that required a
+ // diverging expression
+ // to begin with
+ },
+ }
+ self.maybe_walk_expr(e);
+ }
+ fn visit_block(&mut self, _: &'tcx Block<'_>) {
+ // don't continue over blocks, LateLintPass already does that
+ }
+}
+
+/// Walks up the AST from the given write expression (`vis.write_expr`) looking
+/// for reads to the same variable that are unsequenced relative to the write.
+///
+/// This means reads for which there is a common ancestor between the read and
+/// the write such that
+///
+/// * evaluating the ancestor necessarily evaluates both the read and the write (for example, `&x`
+/// and `|| x = 1` don't necessarily evaluate `x`), and
+///
+/// * which one is evaluated first depends on the order of sub-expression evaluation. Blocks, `if`s,
+/// loops, `match`es, and the short-circuiting logical operators are considered to have a defined
+/// evaluation order.
+///
+/// When such a read is found, the lint is triggered.
+fn check_for_unsequenced_reads(vis: &mut ReadVisitor<'_, '_>) {
+ let map = &vis.cx.tcx.hir();
+ let mut cur_id = vis.write_expr.hir_id;
+ loop {
+ let parent_id = map.get_parent_node(cur_id);
+ if parent_id == cur_id {
+ break;
+ }
+ let parent_node = match map.find(parent_id) {
+ Some(parent) => parent,
+ None => break,
+ };
+
+ let stop_early = match parent_node {
+ Node::Expr(expr) => check_expr(vis, expr),
+ Node::Stmt(stmt) => check_stmt(vis, stmt),
+ Node::Item(_) => {
+ // We reached the top of the function, stop.
+ break;
+ },
+ _ => StopEarly::KeepGoing,
+ };
+ match stop_early {
+ StopEarly::Stop => break,
+ StopEarly::KeepGoing => {},
+ }
+
+ cur_id = parent_id;
+ }
+}
+
+/// Whether to stop early for the loop in `check_for_unsequenced_reads`. (If
+/// `check_expr` weren't an independent function, this would be unnecessary and
+/// we could just use `break`).
+enum StopEarly {
+ KeepGoing,
+ Stop,
+}
+
+fn check_expr<'a, 'tcx>(vis: &mut ReadVisitor<'a, 'tcx>, expr: &'tcx Expr<'_>) -> StopEarly {
+ if expr.hir_id == vis.last_expr.hir_id {
+ return StopEarly::KeepGoing;
+ }
+
+ match expr.kind {
+ ExprKind::Array(_)
+ | ExprKind::Tup(_)
+ | ExprKind::MethodCall(..)
+ | ExprKind::Call(_, _)
+ | ExprKind::Assign(..)
+ | ExprKind::Index(_, _)
+ | ExprKind::Repeat(_, _)
+ | ExprKind::Struct(_, _, _) => {
+ walk_expr(vis, expr);
+ },
+ ExprKind::Binary(op, _, _) | ExprKind::AssignOp(op, _, _) => {
+ if op.node == BinOpKind::And || op.node == BinOpKind::Or {
+ // x && y and x || y always evaluate x first, so these are
+ // strictly sequenced.
+ } else {
+ walk_expr(vis, expr);
+ }
+ },
+ ExprKind::Closure(_, _, _, _, _) => {
+ // Either
+ //
+ // * `var` is defined in the closure body, in which case we've reached the top of the enclosing
+ // function and can stop, or
+ //
+ // * `var` is captured by the closure, in which case, because evaluating a closure does not evaluate
+ // its body, we don't necessarily have a write, so we need to stop to avoid generating false
+ // positives.
+ //
+ // This is also the only place we need to stop early (grrr).
+ return StopEarly::Stop;
+ },
+ // All other expressions either have only one child or strictly
+ // sequence the evaluation order of their sub-expressions.
+ _ => {},
+ }
+
+ vis.last_expr = expr;
+
+ StopEarly::KeepGoing
+}
+
+fn check_stmt<'a, 'tcx>(vis: &mut ReadVisitor<'a, 'tcx>, stmt: &'tcx Stmt<'_>) -> StopEarly {
+ match stmt.kind {
+ StmtKind::Expr(expr) | StmtKind::Semi(expr) => check_expr(vis, expr),
+ // If the declaration is of a local variable, check its initializer
+ // expression if it has one. Otherwise, keep going.
+ StmtKind::Local(local) => local
+ .init
+ .as_ref()
+ .map_or(StopEarly::KeepGoing, |expr| check_expr(vis, expr)),
+ StmtKind::Item(..) => StopEarly::KeepGoing,
+ }
+}
+
+/// A visitor that looks for reads from a variable.
+struct ReadVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ /// The ID of the variable we're looking for.
+ var: HirId,
+ /// The expressions where the write to the variable occurred (for reporting
+ /// in the lint).
+ write_expr: &'tcx Expr<'tcx>,
+ /// The last (highest in the AST) expression we've checked, so we know not
+ /// to recheck it.
+ last_expr: &'tcx Expr<'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for ReadVisitor<'a, 'tcx> {
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if expr.hir_id == self.last_expr.hir_id {
+ return;
+ }
+
+ if path_to_local_id(expr, self.var) {
+ // Check that this is a read, not a write.
+ if !is_in_assignment_position(self.cx, expr) {
+ span_lint_and_note(
+ self.cx,
+ MIXED_READ_WRITE_IN_EXPRESSION,
+ expr.span,
+ &format!("unsequenced read of `{}`", self.cx.tcx.hir().name(self.var)),
+ Some(self.write_expr.span),
+ "whether read occurs before this write depends on evaluation order",
+ );
+ }
+ }
+ match expr.kind {
+ // We're about to descend a closure. Since we don't know when (or
+ // if) the closure will be evaluated, any reads in it might not
+ // occur here (or ever). Like above, bail to avoid false positives.
+ ExprKind::Closure(_, _, _, _, _) |
+
+ // We want to avoid a false positive when a variable name occurs
+ // only to have its address taken, so we stop here. Technically,
+ // this misses some weird cases, eg.
+ //
+ // ```rust
+ // let mut x = 0;
+ // let a = foo(&{x = 1; x}, x);
+ // ```
+ //
+ // TODO: fix this
+ ExprKind::AddrOf(_, _, _) => {
+ return;
+ }
+ _ => {}
+ }
+
+ walk_expr(self, expr);
+ }
+}
+
+/// Returns `true` if `expr` is the LHS of an assignment, like `expr = ...`.
+fn is_in_assignment_position(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ if let Some(parent) = get_parent_expr(cx, expr) {
+ if let ExprKind::Assign(lhs, ..) = parent.kind {
+ return lhs.hir_id == expr.hir_id;
+ }
+ }
+ false
+}
--- /dev/null
- check_ty(cx, local.span, cx.typeck_results().pat_ty(&*local.pat));
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::trait_ref_of_method;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::TypeFoldable;
+use rustc_middle::ty::{Adt, Array, Ref, Slice, Tuple, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use rustc_span::symbol::sym;
+use std::iter;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for sets/maps with mutable key types.
+ ///
+ /// ### Why is this bad?
+ /// All of `HashMap`, `HashSet`, `BTreeMap` and
+ /// `BtreeSet` rely on either the hash or the order of keys be unchanging,
+ /// so having types with interior mutability is a bad idea.
+ ///
+ /// ### Known problems
+ ///
+ /// #### False Positives
+ /// It's correct to use a struct that contains interior mutability as a key, when its
+ /// implementation of `Hash` or `Ord` doesn't access any of the interior mutable types.
+ /// However, this lint is unable to recognize this, so it will often cause false positives in
+ /// theses cases. The `bytes` crate is a great example of this.
+ ///
+ /// #### False Negatives
+ /// For custom `struct`s/`enum`s, this lint is unable to check for interior mutability behind
+ /// indirection. For example, `struct BadKey<'a>(&'a Cell<usize>)` will be seen as immutable
+ /// and cause a false negative if its implementation of `Hash`/`Ord` accesses the `Cell`.
+ ///
+ /// This lint does check a few cases for indirection. Firstly, using some standard library
+ /// types (`Option`, `Result`, `Box`, `Rc`, `Arc`, `Vec`, `VecDeque`, `BTreeMap` and
+ /// `BTreeSet`) directly as keys (e.g. in `HashMap<Box<Cell<usize>>, ()>`) **will** trigger the
+ /// lint, because the impls of `Hash`/`Ord` for these types directly call `Hash`/`Ord` on their
+ /// contained type.
+ ///
+ /// Secondly, the implementations of `Hash` and `Ord` for raw pointers (`*const T` or `*mut T`)
+ /// apply only to the **address** of the contained value. Therefore, interior mutability
+ /// behind raw pointers (e.g. in `HashSet<*mut Cell<usize>>`) can't impact the value of `Hash`
+ /// or `Ord`, and therefore will not trigger this link. For more info, see issue
+ /// [#6745](https://github.com/rust-lang/rust-clippy/issues/6745).
+ ///
+ /// ### Example
+ /// ```rust
+ /// use std::cmp::{PartialEq, Eq};
+ /// use std::collections::HashSet;
+ /// use std::hash::{Hash, Hasher};
+ /// use std::sync::atomic::AtomicUsize;
+ ///# #[allow(unused)]
+ ///
+ /// struct Bad(AtomicUsize);
+ /// impl PartialEq for Bad {
+ /// fn eq(&self, rhs: &Self) -> bool {
+ /// ..
+ /// ; unimplemented!();
+ /// }
+ /// }
+ ///
+ /// impl Eq for Bad {}
+ ///
+ /// impl Hash for Bad {
+ /// fn hash<H: Hasher>(&self, h: &mut H) {
+ /// ..
+ /// ; unimplemented!();
+ /// }
+ /// }
+ ///
+ /// fn main() {
+ /// let _: HashSet<Bad> = HashSet::new();
+ /// }
+ /// ```
+ #[clippy::version = "1.42.0"]
+ pub MUTABLE_KEY_TYPE,
+ suspicious,
+ "Check for mutable `Map`/`Set` key type"
+}
+
+declare_lint_pass!(MutableKeyType => [ MUTABLE_KEY_TYPE ]);
+
+impl<'tcx> LateLintPass<'tcx> for MutableKeyType {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) {
+ if let hir::ItemKind::Fn(ref sig, ..) = item.kind {
+ check_sig(cx, item.hir_id(), sig.decl);
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::ImplItem<'tcx>) {
+ if let hir::ImplItemKind::Fn(ref sig, ..) = item.kind {
+ if trait_ref_of_method(cx, item.def_id).is_none() {
+ check_sig(cx, item.hir_id(), sig.decl);
+ }
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::TraitItem<'tcx>) {
+ if let hir::TraitItemKind::Fn(ref sig, ..) = item.kind {
+ check_sig(cx, item.hir_id(), sig.decl);
+ }
+ }
+
+ fn check_local(&mut self, cx: &LateContext<'_>, local: &hir::Local<'_>) {
+ if let hir::PatKind::Wild = local.pat.kind {
+ return;
+ }
++ check_ty(cx, local.span, cx.typeck_results().pat_ty(local.pat));
+ }
+}
+
+fn check_sig<'tcx>(cx: &LateContext<'tcx>, item_hir_id: hir::HirId, decl: &hir::FnDecl<'_>) {
+ let fn_def_id = cx.tcx.hir().local_def_id(item_hir_id);
+ let fn_sig = cx.tcx.fn_sig(fn_def_id);
+ for (hir_ty, ty) in iter::zip(decl.inputs, fn_sig.inputs().skip_binder()) {
+ check_ty(cx, hir_ty.span, *ty);
+ }
+ check_ty(cx, decl.output.span(), cx.tcx.erase_late_bound_regions(fn_sig.output()));
+}
+
+// We want to lint 1. sets or maps with 2. not immutable key types and 3. no unerased
+// generics (because the compiler cannot ensure immutability for unknown types).
+fn check_ty<'tcx>(cx: &LateContext<'tcx>, span: Span, ty: Ty<'tcx>) {
+ let ty = ty.peel_refs();
+ if let Adt(def, substs) = ty.kind() {
+ let is_keyed_type = [sym::HashMap, sym::BTreeMap, sym::HashSet, sym::BTreeSet]
+ .iter()
+ .any(|diag_item| cx.tcx.is_diagnostic_item(*diag_item, def.did()));
+ if is_keyed_type && is_interior_mutable_type(cx, substs.type_at(0), span) {
+ span_lint(cx, MUTABLE_KEY_TYPE, span, "mutable key type");
+ }
+ }
+}
+
+/// Determines if a type contains interior mutability which would affect its implementation of
+/// [`Hash`] or [`Ord`].
+fn is_interior_mutable_type<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, span: Span) -> bool {
+ match *ty.kind() {
+ Ref(_, inner_ty, mutbl) => mutbl == hir::Mutability::Mut || is_interior_mutable_type(cx, inner_ty, span),
+ Slice(inner_ty) => is_interior_mutable_type(cx, inner_ty, span),
+ Array(inner_ty, size) => {
+ size.try_eval_usize(cx.tcx, cx.param_env).map_or(true, |u| u != 0)
+ && is_interior_mutable_type(cx, inner_ty, span)
+ },
+ Tuple(fields) => fields.iter().any(|ty| is_interior_mutable_type(cx, ty, span)),
+ Adt(def, substs) => {
+ // Special case for collections in `std` who's impl of `Hash` or `Ord` delegates to
+ // that of their type parameters. Note: we don't include `HashSet` and `HashMap`
+ // because they have no impl for `Hash` or `Ord`.
+ let is_std_collection = [
+ sym::Option,
+ sym::Result,
+ sym::LinkedList,
+ sym::Vec,
+ sym::VecDeque,
+ sym::BTreeMap,
+ sym::BTreeSet,
+ sym::Rc,
+ sym::Arc,
+ ]
+ .iter()
+ .any(|diag_item| cx.tcx.is_diagnostic_item(*diag_item, def.did()));
+ let is_box = Some(def.did()) == cx.tcx.lang_items().owned_box();
+ if is_std_collection || is_box {
+ // The type is mutable if any of its type parameters are
+ substs.types().any(|ty| is_interior_mutable_type(cx, ty, span))
+ } else {
+ !ty.has_escaping_bound_vars()
+ && cx.tcx.layout_of(cx.param_env.and(ty)).is_ok()
+ && !ty.is_freeze(cx.tcx.at(span), cx.param_env)
+ }
+ },
+ _ => false,
+ }
+}
--- /dev/null
- /// fn take_a_mut_parameter(_: &mut u32) -> bool { unimplemented!() }
- /// debug_assert!(take_a_mut_parameter(&mut 5));
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::macros::{find_assert_eq_args, root_macro_call_first_node};
+use rustc_hir::intravisit::{walk_expr, Visitor};
+use rustc_hir::{BorrowKind, Expr, ExprKind, MatchSource, Mutability};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::nested_filter;
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::Span;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for function/method calls with a mutable
+ /// parameter in `debug_assert!`, `debug_assert_eq!` and `debug_assert_ne!` macros.
+ ///
+ /// ### Why is this bad?
+ /// In release builds `debug_assert!` macros are optimized out by the
+ /// compiler.
+ /// Therefore mutating something in a `debug_assert!` macro results in different behavior
+ /// between a release and debug build.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// debug_assert_eq!(vec![3].pop(), Some(3));
++ ///
+ /// // or
++ ///
++ /// # let mut x = 5;
++ /// # fn takes_a_mut_parameter(_: &mut u32) -> bool { unimplemented!() }
++ /// debug_assert!(takes_a_mut_parameter(&mut x));
+ /// ```
+ #[clippy::version = "1.40.0"]
+ pub DEBUG_ASSERT_WITH_MUT_CALL,
+ nursery,
+ "mutable arguments in `debug_assert{,_ne,_eq}!`"
+}
+
+declare_lint_pass!(DebugAssertWithMutCall => [DEBUG_ASSERT_WITH_MUT_CALL]);
+
+impl<'tcx> LateLintPass<'tcx> for DebugAssertWithMutCall {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ let Some(macro_call) = root_macro_call_first_node(cx, e) else { return };
+ let macro_name = cx.tcx.item_name(macro_call.def_id);
+ if !matches!(
+ macro_name.as_str(),
+ "debug_assert" | "debug_assert_eq" | "debug_assert_ne"
+ ) {
+ return;
+ }
+ let Some((lhs, rhs, _)) = find_assert_eq_args(cx, e, macro_call.expn) else { return };
+ for arg in [lhs, rhs] {
+ let mut visitor = MutArgVisitor::new(cx);
+ visitor.visit_expr(arg);
+ if let Some(span) = visitor.expr_span() {
+ span_lint(
+ cx,
+ DEBUG_ASSERT_WITH_MUT_CALL,
+ span,
+ &format!(
+ "do not call a function with mutable arguments inside of `{}!`",
+ macro_name
+ ),
+ );
+ }
+ }
+ }
+}
+
+struct MutArgVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ expr_span: Option<Span>,
+ found: bool,
+}
+
+impl<'a, 'tcx> MutArgVisitor<'a, 'tcx> {
+ fn new(cx: &'a LateContext<'tcx>) -> Self {
+ Self {
+ cx,
+ expr_span: None,
+ found: false,
+ }
+ }
+
+ fn expr_span(&self) -> Option<Span> {
+ if self.found { self.expr_span } else { None }
+ }
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for MutArgVisitor<'a, 'tcx> {
+ type NestedFilter = nested_filter::OnlyBodies;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ match expr.kind {
+ ExprKind::AddrOf(BorrowKind::Ref, Mutability::Mut, _) => {
+ self.found = true;
+ return;
+ },
+ ExprKind::If(..) => {
+ self.found = true;
+ return;
+ },
+ ExprKind::Path(_) => {
+ if let Some(adj) = self.cx.typeck_results().adjustments().get(expr.hir_id) {
+ if adj
+ .iter()
+ .any(|a| matches!(a.target.kind(), ty::Ref(_, _, Mutability::Mut)))
+ {
+ self.found = true;
+ return;
+ }
+ }
+ },
+ // Don't check await desugars
+ ExprKind::Match(_, _, MatchSource::AwaitDesugar) => return,
+ _ if !self.found => self.expr_span = Some(expr.span),
+ _ => return,
+ }
+ walk_expr(self, expr);
+ }
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+}
--- /dev/null
- let applicability = if suggestions.len() > 1 {
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::path_to_local;
+use clippy_utils::source::snippet_opt;
+use clippy_utils::ty::needs_ordered_drop;
+use clippy_utils::visitors::{expr_visitor, expr_visitor_no_bodies, is_local_used};
+use rustc_errors::{Applicability, MultiSpan};
+use rustc_hir::intravisit::Visitor;
+use rustc_hir::{
+ BindingAnnotation, Block, Expr, ExprKind, HirId, Local, LocalSource, MatchSource, Node, Pat, PatKind, Stmt,
+ StmtKind,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::Span;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for late initializations that can be replaced by a `let` statement
+ /// with an initializer.
+ ///
+ /// ### Why is this bad?
+ /// Assigning in the `let` statement is less repetitive.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let a;
+ /// a = 1;
+ ///
+ /// let b;
+ /// match 3 {
+ /// 0 => b = "zero",
+ /// 1 => b = "one",
+ /// _ => b = "many",
+ /// }
+ ///
+ /// let c;
+ /// if true {
+ /// c = 1;
+ /// } else {
+ /// c = -1;
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let a = 1;
+ ///
+ /// let b = match 3 {
+ /// 0 => "zero",
+ /// 1 => "one",
+ /// _ => "many",
+ /// };
+ ///
+ /// let c = if true {
+ /// 1
+ /// } else {
+ /// -1
+ /// };
+ /// ```
+ #[clippy::version = "1.58.0"]
+ pub NEEDLESS_LATE_INIT,
+ style,
+ "late initializations that can be replaced by a `let` statement with an initializer"
+}
+declare_lint_pass!(NeedlessLateInit => [NEEDLESS_LATE_INIT]);
+
+fn contains_assign_expr<'tcx>(cx: &LateContext<'tcx>, stmt: &'tcx Stmt<'tcx>) -> bool {
+ let mut seen = false;
+ expr_visitor(cx, |expr| {
+ if let ExprKind::Assign(..) = expr.kind {
+ seen = true;
+ }
+
+ !seen
+ })
+ .visit_stmt(stmt);
+
+ seen
+}
+
+fn contains_let(cond: &Expr<'_>) -> bool {
+ let mut seen = false;
+ expr_visitor_no_bodies(|expr| {
+ if let ExprKind::Let(_) = expr.kind {
+ seen = true;
+ }
+
+ !seen
+ })
+ .visit_expr(cond);
+
+ seen
+}
+
+fn stmt_needs_ordered_drop(cx: &LateContext<'_>, stmt: &Stmt<'_>) -> bool {
+ let StmtKind::Local(local) = stmt.kind else { return false };
+ !local.pat.walk_short(|pat| {
+ if let PatKind::Binding(.., None) = pat.kind {
+ !needs_ordered_drop(cx, cx.typeck_results().pat_ty(pat))
+ } else {
+ true
+ }
+ })
+}
+
+#[derive(Debug)]
+struct LocalAssign {
+ lhs_id: HirId,
+ lhs_span: Span,
+ rhs_span: Span,
+ span: Span,
+}
+
+impl LocalAssign {
+ fn from_expr(expr: &Expr<'_>, span: Span) -> Option<Self> {
+ if let ExprKind::Assign(lhs, rhs, _) = expr.kind {
+ if lhs.span.from_expansion() {
+ return None;
+ }
+
+ Some(Self {
+ lhs_id: path_to_local(lhs)?,
+ lhs_span: lhs.span,
+ rhs_span: rhs.span.source_callsite(),
+ span,
+ })
+ } else {
+ None
+ }
+ }
+
+ fn new<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>, binding_id: HirId) -> Option<LocalAssign> {
+ let assign = match expr.kind {
+ ExprKind::Block(Block { expr: Some(expr), .. }, _) => Self::from_expr(expr, expr.span),
+ ExprKind::Block(block, _) => {
+ if_chain! {
+ if let Some((last, other_stmts)) = block.stmts.split_last();
+ if let StmtKind::Expr(expr) | StmtKind::Semi(expr) = last.kind;
+
+ let assign = Self::from_expr(expr, last.span)?;
+
+ // avoid visiting if not needed
+ if assign.lhs_id == binding_id;
+ if other_stmts.iter().all(|stmt| !contains_assign_expr(cx, stmt));
+
+ then {
+ Some(assign)
+ } else {
+ None
+ }
+ }
+ },
+ ExprKind::Assign(..) => Self::from_expr(expr, expr.span),
+ _ => None,
+ }?;
+
+ if assign.lhs_id == binding_id {
+ Some(assign)
+ } else {
+ None
+ }
+ }
+}
+
+fn assignment_suggestions<'tcx>(
+ cx: &LateContext<'tcx>,
+ binding_id: HirId,
+ exprs: impl IntoIterator<Item = &'tcx Expr<'tcx>>,
+) -> Option<(Applicability, Vec<(Span, String)>)> {
+ let mut assignments = Vec::new();
+
+ for expr in exprs {
+ let ty = cx.typeck_results().expr_ty(expr);
+
+ if ty.is_never() {
+ continue;
+ }
+ if !ty.is_unit() {
+ return None;
+ }
+
+ let assign = LocalAssign::new(cx, expr, binding_id)?;
+
+ assignments.push(assign);
+ }
+
+ let suggestions = assignments
+ .iter()
+ .map(|assignment| Some((assignment.span.until(assignment.rhs_span), String::new())))
+ .chain(assignments.iter().map(|assignment| {
+ Some((
+ assignment.rhs_span.shrink_to_hi().with_hi(assignment.span.hi()),
+ String::new(),
+ ))
+ }))
+ .collect::<Option<Vec<(Span, String)>>>()?;
+
- Applicability::Unspecified
- } else {
- Applicability::MachineApplicable
- };
- Some((applicability, suggestions))
++ match suggestions.len() {
++ // All of `exprs` are never types
++ // https://github.com/rust-lang/rust-clippy/issues/8911
++ 0 => None,
++ 1 => Some((Applicability::MachineApplicable, suggestions)),
+ // multiple suggestions don't work with rustfix in multipart_suggest
+ // https://github.com/rust-lang/rustfix/issues/141
++ _ => Some((Applicability::Unspecified, suggestions)),
++ }
+}
+
+struct Usage<'tcx> {
+ stmt: &'tcx Stmt<'tcx>,
+ expr: &'tcx Expr<'tcx>,
+ needs_semi: bool,
+}
+
+fn first_usage<'tcx>(
+ cx: &LateContext<'tcx>,
+ binding_id: HirId,
+ local_stmt_id: HirId,
+ block: &'tcx Block<'tcx>,
+) -> Option<Usage<'tcx>> {
+ let significant_drop = needs_ordered_drop(cx, cx.typeck_results().node_type(binding_id));
+
+ block
+ .stmts
+ .iter()
+ .skip_while(|stmt| stmt.hir_id != local_stmt_id)
+ .skip(1)
+ .take_while(|stmt| !significant_drop || !stmt_needs_ordered_drop(cx, stmt))
+ .find(|&stmt| is_local_used(cx, stmt, binding_id))
+ .and_then(|stmt| match stmt.kind {
+ StmtKind::Expr(expr) => Some(Usage {
+ stmt,
+ expr,
+ needs_semi: true,
+ }),
+ StmtKind::Semi(expr) => Some(Usage {
+ stmt,
+ expr,
+ needs_semi: false,
+ }),
+ _ => None,
+ })
+}
+
+fn local_snippet_without_semicolon(cx: &LateContext<'_>, local: &Local<'_>) -> Option<String> {
+ let span = local.span.with_hi(match local.ty {
+ // let <pat>: <ty>;
+ // ~~~~~~~~~~~~~~~
+ Some(ty) => ty.span.hi(),
+ // let <pat>;
+ // ~~~~~~~~~
+ None => local.pat.span.hi(),
+ });
+
+ snippet_opt(cx, span)
+}
+
+fn check<'tcx>(
+ cx: &LateContext<'tcx>,
+ local: &'tcx Local<'tcx>,
+ local_stmt: &'tcx Stmt<'tcx>,
+ block: &'tcx Block<'tcx>,
+ binding_id: HirId,
+) -> Option<()> {
+ let usage = first_usage(cx, binding_id, local_stmt.hir_id, block)?;
+ let binding_name = cx.tcx.hir().opt_name(binding_id)?;
+ let let_snippet = local_snippet_without_semicolon(cx, local)?;
+
+ match usage.expr.kind {
+ ExprKind::Assign(..) => {
+ let assign = LocalAssign::new(cx, usage.expr, binding_id)?;
+ let mut msg_span = MultiSpan::from_spans(vec![local_stmt.span, assign.span]);
+ msg_span.push_span_label(local_stmt.span, "created here");
+ msg_span.push_span_label(assign.span, "initialised here");
+
+ span_lint_and_then(
+ cx,
+ NEEDLESS_LATE_INIT,
+ msg_span,
+ "unneeded late initialization",
+ |diag| {
+ diag.tool_only_span_suggestion(
+ local_stmt.span,
+ "remove the local",
+ String::new(),
+ Applicability::MachineApplicable,
+ );
+
+ diag.span_suggestion(
+ assign.lhs_span,
+ &format!("declare `{}` here", binding_name),
+ let_snippet,
+ Applicability::MachineApplicable,
+ );
+ },
+ );
+ },
+ ExprKind::If(cond, then_expr, Some(else_expr)) if !contains_let(cond) => {
+ let (applicability, suggestions) = assignment_suggestions(cx, binding_id, [then_expr, else_expr])?;
+
+ span_lint_and_then(
+ cx,
+ NEEDLESS_LATE_INIT,
+ local_stmt.span,
+ "unneeded late initialization",
+ |diag| {
+ diag.tool_only_span_suggestion(local_stmt.span, "remove the local", String::new(), applicability);
+
+ diag.span_suggestion_verbose(
+ usage.stmt.span.shrink_to_lo(),
+ &format!("declare `{}` here", binding_name),
+ format!("{} = ", let_snippet),
+ applicability,
+ );
+
+ diag.multipart_suggestion("remove the assignments from the branches", suggestions, applicability);
+
+ if usage.needs_semi {
+ diag.span_suggestion(
+ usage.stmt.span.shrink_to_hi(),
+ "add a semicolon after the `if` expression",
+ ";".to_string(),
+ applicability,
+ );
+ }
+ },
+ );
+ },
+ ExprKind::Match(_, arms, MatchSource::Normal) => {
+ let (applicability, suggestions) = assignment_suggestions(cx, binding_id, arms.iter().map(|arm| arm.body))?;
+
+ span_lint_and_then(
+ cx,
+ NEEDLESS_LATE_INIT,
+ local_stmt.span,
+ "unneeded late initialization",
+ |diag| {
+ diag.tool_only_span_suggestion(local_stmt.span, "remove the local", String::new(), applicability);
+
+ diag.span_suggestion_verbose(
+ usage.stmt.span.shrink_to_lo(),
+ &format!("declare `{}` here", binding_name),
+ format!("{} = ", let_snippet),
+ applicability,
+ );
+
+ diag.multipart_suggestion(
+ "remove the assignments from the `match` arms",
+ suggestions,
+ applicability,
+ );
+
+ if usage.needs_semi {
+ diag.span_suggestion(
+ usage.stmt.span.shrink_to_hi(),
+ "add a semicolon after the `match` expression",
+ ";".to_string(),
+ applicability,
+ );
+ }
+ },
+ );
+ },
+ _ => {},
+ };
+
+ Some(())
+}
+
+impl<'tcx> LateLintPass<'tcx> for NeedlessLateInit {
+ fn check_local(&mut self, cx: &LateContext<'tcx>, local: &'tcx Local<'tcx>) {
+ let mut parents = cx.tcx.hir().parent_iter(local.hir_id);
+ if_chain! {
+ if let Local {
+ init: None,
+ pat: &Pat {
+ kind: PatKind::Binding(BindingAnnotation::Unannotated, binding_id, _, None),
+ ..
+ },
+ source: LocalSource::Normal,
+ ..
+ } = local;
+ if let Some((_, Node::Stmt(local_stmt))) = parents.next();
+ if let Some((_, Node::Block(block))) = parents.next();
+
+ then {
+ check(cx, local, local_stmt, block, binding_id);
+ }
+ }
+ }
+}
--- /dev/null
--- /dev/null
++use clippy_utils::consts::constant_simple;
++use clippy_utils::diagnostics::span_lint;
++use rustc_hir as hir;
++use rustc_lint::{LateContext, LateLintPass};
++use rustc_session::{declare_tool_lint, impl_lint_pass};
++use rustc_span::source_map::Span;
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for integer arithmetic operations which could overflow or panic.
++ ///
++ /// Specifically, checks for any operators (`+`, `-`, `*`, `<<`, etc) which are capable
++ /// of overflowing according to the [Rust
++ /// Reference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#overflow),
++ /// or which can panic (`/`, `%`). No bounds analysis or sophisticated reasoning is
++ /// attempted.
++ ///
++ /// ### Why is this bad?
++ /// Integer overflow will trigger a panic in debug builds or will wrap in
++ /// release mode. Division by zero will cause a panic in either mode. In some applications one
++ /// wants explicitly checked, wrapping or saturating arithmetic.
++ ///
++ /// ### Example
++ /// ```rust
++ /// # let a = 0;
++ /// a + 1;
++ /// ```
++ #[clippy::version = "pre 1.29.0"]
++ pub INTEGER_ARITHMETIC,
++ restriction,
++ "any integer arithmetic expression which could overflow or panic"
++}
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for float arithmetic.
++ ///
++ /// ### Why is this bad?
++ /// For some embedded systems or kernel development, it
++ /// can be useful to rule out floating-point numbers.
++ ///
++ /// ### Example
++ /// ```rust
++ /// # let a = 0.0;
++ /// a + 1.0;
++ /// ```
++ #[clippy::version = "pre 1.29.0"]
++ pub FLOAT_ARITHMETIC,
++ restriction,
++ "any floating-point arithmetic statement"
++}
++
++#[derive(Copy, Clone, Default)]
++pub struct NumericArithmetic {
++ expr_span: Option<Span>,
++ /// This field is used to check whether expressions are constants, such as in enum discriminants
++ /// and consts
++ const_span: Option<Span>,
++}
++
++impl_lint_pass!(NumericArithmetic => [INTEGER_ARITHMETIC, FLOAT_ARITHMETIC]);
++
++impl<'tcx> LateLintPass<'tcx> for NumericArithmetic {
++ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
++ if self.expr_span.is_some() {
++ return;
++ }
++
++ if let Some(span) = self.const_span {
++ if span.contains(expr.span) {
++ return;
++ }
++ }
++ match &expr.kind {
++ hir::ExprKind::Binary(op, l, r) | hir::ExprKind::AssignOp(op, l, r) => {
++ match op.node {
++ hir::BinOpKind::And
++ | hir::BinOpKind::Or
++ | hir::BinOpKind::BitAnd
++ | hir::BinOpKind::BitOr
++ | hir::BinOpKind::BitXor
++ | hir::BinOpKind::Eq
++ | hir::BinOpKind::Lt
++ | hir::BinOpKind::Le
++ | hir::BinOpKind::Ne
++ | hir::BinOpKind::Ge
++ | hir::BinOpKind::Gt => return,
++ _ => (),
++ }
++
++ let (l_ty, r_ty) = (cx.typeck_results().expr_ty(l), cx.typeck_results().expr_ty(r));
++ if l_ty.peel_refs().is_integral() && r_ty.peel_refs().is_integral() {
++ match op.node {
++ hir::BinOpKind::Div | hir::BinOpKind::Rem => match &r.kind {
++ hir::ExprKind::Lit(_lit) => (),
++ hir::ExprKind::Unary(hir::UnOp::Neg, expr) => {
++ if let hir::ExprKind::Lit(lit) = &expr.kind {
++ if let rustc_ast::ast::LitKind::Int(1, _) = lit.node {
++ span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
++ self.expr_span = Some(expr.span);
++ }
++ }
++ },
++ _ => {
++ span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
++ self.expr_span = Some(expr.span);
++ },
++ },
++ _ => {
++ span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
++ self.expr_span = Some(expr.span);
++ },
++ }
++ } else if r_ty.peel_refs().is_floating_point() && r_ty.peel_refs().is_floating_point() {
++ span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
++ self.expr_span = Some(expr.span);
++ }
++ },
++ hir::ExprKind::Unary(hir::UnOp::Neg, arg) => {
++ let ty = cx.typeck_results().expr_ty(arg);
++ if constant_simple(cx, cx.typeck_results(), expr).is_none() {
++ if ty.is_integral() {
++ span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
++ self.expr_span = Some(expr.span);
++ } else if ty.is_floating_point() {
++ span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
++ self.expr_span = Some(expr.span);
++ }
++ }
++ },
++ _ => (),
++ }
++ }
++
++ fn check_expr_post(&mut self, _: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
++ if Some(expr.span) == self.expr_span {
++ self.expr_span = None;
++ }
++ }
++
++ fn check_body(&mut self, cx: &LateContext<'_>, body: &hir::Body<'_>) {
++ let body_owner = cx.tcx.hir().body_owner_def_id(body.id());
++
++ match cx.tcx.hir().body_owner_kind(body_owner) {
++ hir::BodyOwnerKind::Static(_) | hir::BodyOwnerKind::Const => {
++ let body_span = cx.tcx.def_span(body_owner);
++
++ if let Some(span) = self.const_span {
++ if span.contains(body_span) {
++ return;
++ }
++ }
++ self.const_span = Some(body_span);
++ },
++ hir::BodyOwnerKind::Fn | hir::BodyOwnerKind::Closure => (),
++ }
++ }
++
++ fn check_body_post(&mut self, cx: &LateContext<'_>, body: &hir::Body<'_>) {
++ let body_owner = cx.tcx.hir().body_owner(body.id());
++ let body_span = cx.tcx.hir().span(body_owner);
++
++ if let Some(span) = self.const_span {
++ if span.contains(body_span) {
++ return;
++ }
++ }
++ self.const_span = None;
++ }
++}
--- /dev/null
- &*cx.tcx.item_name(macro_call.def_id).as_str(),
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::macros::root_macro_call_first_node;
+use clippy_utils::return_ty;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::visitors::expr_visitor_no_bodies;
+use rustc_hir as hir;
+use rustc_hir::intravisit::{FnKind, Visitor};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::{sym, Span};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `panic!`, `unimplemented!`, `todo!`, `unreachable!` or assertions in a function of type result.
+ ///
+ /// ### Why is this bad?
+ /// For some codebases, it is desirable for functions of type result to return an error instead of crashing. Hence panicking macros should be avoided.
+ ///
+ /// ### Known problems
+ /// Functions called from a function returning a `Result` may invoke a panicking macro. This is not checked.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn result_with_panic() -> Result<bool, String>
+ /// {
+ /// panic!("error");
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// fn result_without_panic() -> Result<bool, String> {
+ /// Err(String::from("error"))
+ /// }
+ /// ```
+ #[clippy::version = "1.48.0"]
+ pub PANIC_IN_RESULT_FN,
+ restriction,
+ "functions of type `Result<..>` that contain `panic!()`, `todo!()`, `unreachable()`, `unimplemented()` or assertion"
+}
+
+declare_lint_pass!(PanicInResultFn => [PANIC_IN_RESULT_FN]);
+
+impl<'tcx> LateLintPass<'tcx> for PanicInResultFn {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ fn_kind: FnKind<'tcx>,
+ _: &'tcx hir::FnDecl<'tcx>,
+ body: &'tcx hir::Body<'tcx>,
+ span: Span,
+ hir_id: hir::HirId,
+ ) {
+ if !matches!(fn_kind, FnKind::Closure) && is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym::Result) {
+ lint_impl_body(cx, span, body);
+ }
+ }
+}
+
+fn lint_impl_body<'tcx>(cx: &LateContext<'tcx>, impl_span: Span, body: &'tcx hir::Body<'tcx>) {
+ let mut panics = Vec::new();
+ expr_visitor_no_bodies(|expr| {
+ let Some(macro_call) = root_macro_call_first_node(cx, expr) else { return true };
+ if matches!(
++ cx.tcx.item_name(macro_call.def_id).as_str(),
+ "unimplemented" | "unreachable" | "panic" | "todo" | "assert" | "assert_eq" | "assert_ne"
+ ) {
+ panics.push(macro_call.span);
+ return false;
+ }
+ true
+ })
+ .visit_expr(&body.value);
+ if !panics.is_empty() {
+ span_lint_and_then(
+ cx,
+ PANIC_IN_RESULT_FN,
+ impl_span,
+ "used `unimplemented!()`, `unreachable!()`, `todo!()`, `panic!()` or assertion in a function that returns `Result`",
+ move |diag| {
+ diag.help(
+ "`unimplemented!()`, `unreachable!()`, `todo!()`, `panic!()` or assertions should not be used in a function that returns `Result` as `Result` is expected to return an error instead of crashing",
+ );
+ diag.span_note(panics, "return Err() instead of panicking");
+ },
+ );
+ }
+}
--- /dev/null
- self.check_poly_fn(cx, item.def_id, &*method_sig.decl, None);
+use std::cmp;
+use std::iter;
+
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet;
+use clippy_utils::ty::is_copy;
+use clippy_utils::{is_self, is_self_ty};
+use if_chain::if_chain;
+use rustc_ast::attr;
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::intravisit::FnKind;
+use rustc_hir::{BindingAnnotation, Body, FnDecl, HirId, Impl, ItemKind, MutTy, Mutability, Node, PatKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_middle::ty::layout::LayoutOf;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::LocalDefId;
+use rustc_span::{sym, Span};
+use rustc_target::spec::abi::Abi;
+use rustc_target::spec::Target;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for functions taking arguments by reference, where
+ /// the argument type is `Copy` and small enough to be more efficient to always
+ /// pass by value.
+ ///
+ /// ### Why is this bad?
+ /// In many calling conventions instances of structs will
+ /// be passed through registers if they fit into two or less general purpose
+ /// registers.
+ ///
+ /// ### Known problems
+ /// This lint is target register size dependent, it is
+ /// limited to 32-bit to try and reduce portability problems between 32 and
+ /// 64-bit, but if you are compiling for 8 or 16-bit targets then the limit
+ /// will be different.
+ ///
+ /// The configuration option `trivial_copy_size_limit` can be set to override
+ /// this limit for a project.
+ ///
+ /// This lint attempts to allow passing arguments by reference if a reference
+ /// to that argument is returned. This is implemented by comparing the lifetime
+ /// of the argument and return value for equality. However, this can cause
+ /// false positives in cases involving multiple lifetimes that are bounded by
+ /// each other.
+ ///
+ /// Also, it does not take account of other similar cases where getting memory addresses
+ /// matters; namely, returning the pointer to the argument in question,
+ /// and passing the argument, as both references and pointers,
+ /// to a function that needs the memory address. For further details, refer to
+ /// [this issue](https://github.com/rust-lang/rust-clippy/issues/5953)
+ /// that explains a real case in which this false positive
+ /// led to an **undefined behavior** introduced with unsafe code.
+ ///
+ /// ### Example
+ ///
+ /// ```rust
+ /// // Bad
+ /// fn foo(v: &u32) {}
+ /// ```
+ ///
+ /// ```rust
+ /// // Better
+ /// fn foo(v: u32) {}
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub TRIVIALLY_COPY_PASS_BY_REF,
+ pedantic,
+ "functions taking small copyable arguments by reference"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for functions taking arguments by value, where
+ /// the argument type is `Copy` and large enough to be worth considering
+ /// passing by reference. Does not trigger if the function is being exported,
+ /// because that might induce API breakage, if the parameter is declared as mutable,
+ /// or if the argument is a `self`.
+ ///
+ /// ### Why is this bad?
+ /// Arguments passed by value might result in an unnecessary
+ /// shallow copy, taking up more space in the stack and requiring a call to
+ /// `memcpy`, which can be expensive.
+ ///
+ /// ### Example
+ /// ```rust
+ /// #[derive(Clone, Copy)]
+ /// struct TooLarge([u8; 2048]);
+ ///
+ /// // Bad
+ /// fn foo(v: TooLarge) {}
+ /// ```
+ /// ```rust
+ /// #[derive(Clone, Copy)]
+ /// struct TooLarge([u8; 2048]);
+ ///
+ /// // Good
+ /// fn foo(v: &TooLarge) {}
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub LARGE_TYPES_PASSED_BY_VALUE,
+ pedantic,
+ "functions taking large arguments by value"
+}
+
+#[derive(Copy, Clone)]
+pub struct PassByRefOrValue {
+ ref_min_size: u64,
+ value_max_size: u64,
+ avoid_breaking_exported_api: bool,
+}
+
+impl<'tcx> PassByRefOrValue {
+ pub fn new(
+ ref_min_size: Option<u64>,
+ value_max_size: u64,
+ avoid_breaking_exported_api: bool,
+ target: &Target,
+ ) -> Self {
+ let ref_min_size = ref_min_size.unwrap_or_else(|| {
+ let bit_width = u64::from(target.pointer_width);
+ // Cap the calculated bit width at 32-bits to reduce
+ // portability problems between 32 and 64-bit targets
+ let bit_width = cmp::min(bit_width, 32);
+ #[expect(clippy::integer_division)]
+ let byte_width = bit_width / 8;
+ // Use a limit of 2 times the register byte width
+ byte_width * 2
+ });
+
+ Self {
+ ref_min_size,
+ value_max_size,
+ avoid_breaking_exported_api,
+ }
+ }
+
+ fn check_poly_fn(&mut self, cx: &LateContext<'tcx>, def_id: LocalDefId, decl: &FnDecl<'_>, span: Option<Span>) {
+ if self.avoid_breaking_exported_api && cx.access_levels.is_exported(def_id) {
+ return;
+ }
+
+ let fn_sig = cx.tcx.fn_sig(def_id);
+ let fn_sig = cx.tcx.erase_late_bound_regions(fn_sig);
+
+ let fn_body = cx.enclosing_body.map(|id| cx.tcx.hir().body(id));
+
+ for (index, (input, &ty)) in iter::zip(decl.inputs, fn_sig.inputs()).enumerate() {
+ // All spans generated from a proc-macro invocation are the same...
+ match span {
+ Some(s) if s == input.span => return,
+ _ => (),
+ }
+
+ match ty.kind() {
+ ty::Ref(input_lt, ty, Mutability::Not) => {
+ // Use lifetimes to determine if we're returning a reference to the
+ // argument. In that case we can't switch to pass-by-value as the
+ // argument will not live long enough.
+ let output_lts = match *fn_sig.output().kind() {
+ ty::Ref(output_lt, _, _) => vec![output_lt],
+ ty::Adt(_, substs) => substs.regions().collect(),
+ _ => vec![],
+ };
+
+ if_chain! {
+ if !output_lts.contains(input_lt);
+ if is_copy(cx, *ty);
+ if let Some(size) = cx.layout_of(*ty).ok().map(|l| l.size.bytes());
+ if size <= self.ref_min_size;
+ if let hir::TyKind::Rptr(_, MutTy { ty: decl_ty, .. }) = input.kind;
+ then {
+ let value_type = if fn_body.and_then(|body| body.params.get(index)).map_or(false, is_self) {
+ "self".into()
+ } else {
+ snippet(cx, decl_ty.span, "_").into()
+ };
+ span_lint_and_sugg(
+ cx,
+ TRIVIALLY_COPY_PASS_BY_REF,
+ input.span,
+ &format!("this argument ({} byte) is passed by reference, but would be more efficient if passed by value (limit: {} byte)", size, self.ref_min_size),
+ "consider passing by value instead",
+ value_type,
+ Applicability::Unspecified,
+ );
+ }
+ }
+ },
+
+ ty::Adt(_, _) | ty::Array(_, _) | ty::Tuple(_) => {
+ // if function has a body and parameter is annotated with mut, ignore
+ if let Some(param) = fn_body.and_then(|body| body.params.get(index)) {
+ match param.pat.kind {
+ PatKind::Binding(BindingAnnotation::Unannotated, _, _, _) => {},
+ _ => continue,
+ }
+ }
+
+ if_chain! {
+ if is_copy(cx, ty);
+ if !is_self_ty(input);
+ if let Some(size) = cx.layout_of(ty).ok().map(|l| l.size.bytes());
+ if size > self.value_max_size;
+ then {
+ span_lint_and_sugg(
+ cx,
+ LARGE_TYPES_PASSED_BY_VALUE,
+ input.span,
+ &format!("this argument ({} byte) is passed by value, but might be more efficient if passed by reference (limit: {} byte)", size, self.value_max_size),
+ "consider passing by reference instead",
+ format!("&{}", snippet(cx, input.span, "_")),
+ Applicability::MaybeIncorrect,
+ );
+ }
+ }
+ },
+
+ _ => {},
+ }
+ }
+ }
+}
+
+impl_lint_pass!(PassByRefOrValue => [TRIVIALLY_COPY_PASS_BY_REF, LARGE_TYPES_PASSED_BY_VALUE]);
+
+impl<'tcx> LateLintPass<'tcx> for PassByRefOrValue {
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::TraitItem<'_>) {
+ if item.span.from_expansion() {
+ return;
+ }
+
+ if let hir::TraitItemKind::Fn(method_sig, _) = &item.kind {
++ self.check_poly_fn(cx, item.def_id, method_sig.decl, None);
+ }
+ }
+
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ kind: FnKind<'tcx>,
+ decl: &'tcx FnDecl<'_>,
+ _body: &'tcx Body<'_>,
+ span: Span,
+ hir_id: HirId,
+ ) {
+ if span.from_expansion() {
+ return;
+ }
+
+ match kind {
+ FnKind::ItemFn(.., header) => {
+ if header.abi != Abi::Rust {
+ return;
+ }
+ let attrs = cx.tcx.hir().attrs(hir_id);
+ for a in attrs {
+ if let Some(meta_items) = a.meta_item_list() {
+ if a.has_name(sym::proc_macro_derive)
+ || (a.has_name(sym::inline) && attr::list_contains_name(&meta_items, sym::always))
+ {
+ return;
+ }
+ }
+ }
+ },
+ FnKind::Method(..) => (),
+ FnKind::Closure => return,
+ }
+
+ // Exclude non-inherent impls
+ if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) {
+ if matches!(
+ item.kind,
+ ItemKind::Impl(Impl { of_trait: Some(_), .. }) | ItemKind::Trait(..)
+ ) {
+ return;
+ }
+ }
+
+ self.check_poly_fn(cx, cx.tcx.hir().local_def_id(hir_id), decl, Some(span));
+ }
+}
--- /dev/null
- check_possible_range_contains(cx, op.node, l, r, expr);
+use clippy_utils::consts::{constant, Constant};
+use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::source::{snippet, snippet_opt, snippet_with_applicability};
+use clippy_utils::sugg::Sugg;
+use clippy_utils::{get_parent_expr, in_constant, is_integer_const, meets_msrv, msrvs, path_to_local};
+use clippy_utils::{higher, SpanlessEq};
+use if_chain::if_chain;
+use rustc_ast::ast::RangeLimits;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind, HirId, PathSegment, QPath};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::{Span, Spanned};
+use rustc_span::sym;
+use std::cmp::Ordering;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for zipping a collection with the range of
+ /// `0.._.len()`.
+ ///
+ /// ### Why is this bad?
+ /// The code is better expressed with `.enumerate()`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let x = vec![1];
+ /// x.iter().zip(0..x.len());
+ /// ```
+ /// Could be written as
+ /// ```rust
+ /// # let x = vec![1];
+ /// x.iter().enumerate();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub RANGE_ZIP_WITH_LEN,
+ complexity,
+ "zipping iterator with a range when `enumerate()` would do"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for exclusive ranges where 1 is added to the
+ /// upper bound, e.g., `x..(y+1)`.
+ ///
+ /// ### Why is this bad?
+ /// The code is more readable with an inclusive range
+ /// like `x..=y`.
+ ///
+ /// ### Known problems
+ /// Will add unnecessary pair of parentheses when the
+ /// expression is not wrapped in a pair but starts with an opening parenthesis
+ /// and ends with a closing one.
+ /// I.e., `let _ = (f()+1)..(f()+1)` results in `let _ = ((f()+1)..=f())`.
+ ///
+ /// Also in many cases, inclusive ranges are still slower to run than
+ /// exclusive ranges, because they essentially add an extra branch that
+ /// LLVM may fail to hoist out of the loop.
+ ///
+ /// This will cause a warning that cannot be fixed if the consumer of the
+ /// range only accepts a specific range type, instead of the generic
+ /// `RangeBounds` trait
+ /// ([#3307](https://github.com/rust-lang/rust-clippy/issues/3307)).
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// for x..(y+1) { .. }
+ /// ```
+ /// Could be written as
+ /// ```rust,ignore
+ /// for x..=y { .. }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub RANGE_PLUS_ONE,
+ pedantic,
+ "`x..(y+1)` reads better as `x..=y`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for inclusive ranges where 1 is subtracted from
+ /// the upper bound, e.g., `x..=(y-1)`.
+ ///
+ /// ### Why is this bad?
+ /// The code is more readable with an exclusive range
+ /// like `x..y`.
+ ///
+ /// ### Known problems
+ /// This will cause a warning that cannot be fixed if
+ /// the consumer of the range only accepts a specific range type, instead of
+ /// the generic `RangeBounds` trait
+ /// ([#3307](https://github.com/rust-lang/rust-clippy/issues/3307)).
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// for x..=(y-1) { .. }
+ /// ```
+ /// Could be written as
+ /// ```rust,ignore
+ /// for x..y { .. }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub RANGE_MINUS_ONE,
+ pedantic,
+ "`x..=(y-1)` reads better as `x..y`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for range expressions `x..y` where both `x` and `y`
+ /// are constant and `x` is greater or equal to `y`.
+ ///
+ /// ### Why is this bad?
+ /// Empty ranges yield no values so iterating them is a no-op.
+ /// Moreover, trying to use a reversed range to index a slice will panic at run-time.
+ ///
+ /// ### Example
+ /// ```rust,no_run
+ /// fn main() {
+ /// (10..=0).for_each(|x| println!("{}", x));
+ ///
+ /// let arr = [1, 2, 3, 4, 5];
+ /// let sub = &arr[3..1];
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// fn main() {
+ /// (0..=10).rev().for_each(|x| println!("{}", x));
+ ///
+ /// let arr = [1, 2, 3, 4, 5];
+ /// let sub = &arr[1..3];
+ /// }
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub REVERSED_EMPTY_RANGES,
+ correctness,
+ "reversing the limits of range expressions, resulting in empty ranges"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for expressions like `x >= 3 && x < 8` that could
+ /// be more readably expressed as `(3..8).contains(x)`.
+ ///
+ /// ### Why is this bad?
+ /// `contains` expresses the intent better and has less
+ /// failure modes (such as fencepost errors or using `||` instead of `&&`).
+ ///
+ /// ### Example
+ /// ```rust
+ /// // given
+ /// let x = 6;
+ ///
+ /// assert!(x >= 3 && x < 8);
+ /// ```
+ /// Use instead:
+ /// ```rust
+ ///# let x = 6;
+ /// assert!((3..8).contains(&x));
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub MANUAL_RANGE_CONTAINS,
+ style,
+ "manually reimplementing {`Range`, `RangeInclusive`}`::contains`"
+}
+
+pub struct Ranges {
+ msrv: Option<RustcVersion>,
+}
+
+impl Ranges {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self { msrv }
+ }
+}
+
+impl_lint_pass!(Ranges => [
+ RANGE_ZIP_WITH_LEN,
+ RANGE_PLUS_ONE,
+ RANGE_MINUS_ONE,
+ REVERSED_EMPTY_RANGES,
+ MANUAL_RANGE_CONTAINS,
+]);
+
+impl<'tcx> LateLintPass<'tcx> for Ranges {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ match expr.kind {
+ ExprKind::MethodCall(path, args, _) => {
+ check_range_zip_with_len(cx, path, args, expr.span);
+ },
+ ExprKind::Binary(ref op, l, r) => {
+ if meets_msrv(self.msrv, msrvs::RANGE_CONTAINS) {
- let span = expr.span;
++ check_possible_range_contains(cx, op.node, l, r, expr, expr.span);
+ }
+ },
+ _ => {},
+ }
+
+ check_exclusive_range_plus_one(cx, expr);
+ check_inclusive_range_minus_one(cx, expr);
+ check_reversed_empty_range(cx, expr);
+ }
+ extract_msrv_attr!(LateContext);
+}
+
+fn check_possible_range_contains(
+ cx: &LateContext<'_>,
+ op: BinOpKind,
+ left: &Expr<'_>,
+ right: &Expr<'_>,
+ expr: &Expr<'_>,
++ span: Span,
+) {
+ if in_constant(cx, expr.hir_id) {
+ return;
+ }
+
+ let combine_and = match op {
+ BinOpKind::And | BinOpKind::BitAnd => true,
+ BinOpKind::Or | BinOpKind::BitOr => false,
+ _ => return,
+ };
+ // value, name, order (higher/lower), inclusiveness
+ if let (Some(l), Some(r)) = (check_range_bounds(cx, left), check_range_bounds(cx, right)) {
+ // we only lint comparisons on the same name and with different
+ // direction
+ if l.id != r.id || l.ord == r.ord {
+ return;
+ }
+ let ord = Constant::partial_cmp(cx.tcx, cx.typeck_results().expr_ty(l.expr), &l.val, &r.val);
+ if combine_and && ord == Some(r.ord) {
+ // order lower bound and upper bound
+ let (l_span, u_span, l_inc, u_inc) = if r.ord == Ordering::Less {
+ (l.val_span, r.val_span, l.inc, r.inc)
+ } else {
+ (r.val_span, l.val_span, r.inc, l.inc)
+ };
+ // we only lint inclusive lower bounds
+ if !l_inc {
+ return;
+ }
+ let (range_type, range_op) = if u_inc {
+ ("RangeInclusive", "..=")
+ } else {
+ ("Range", "..")
+ };
+ let mut applicability = Applicability::MachineApplicable;
+ let name = snippet_with_applicability(cx, l.name_span, "_", &mut applicability);
+ let lo = snippet_with_applicability(cx, l_span, "_", &mut applicability);
+ let hi = snippet_with_applicability(cx, u_span, "_", &mut applicability);
+ let space = if lo.ends_with('.') { " " } else { "" };
+ span_lint_and_sugg(
+ cx,
+ MANUAL_RANGE_CONTAINS,
+ span,
+ &format!("manual `{}::contains` implementation", range_type),
+ "use",
+ format!("({}{}{}{}).contains(&{})", lo, space, range_op, hi, name),
+ applicability,
+ );
+ } else if !combine_and && ord == Some(l.ord) {
+ // `!_.contains(_)`
+ // order lower bound and upper bound
+ let (l_span, u_span, l_inc, u_inc) = if l.ord == Ordering::Less {
+ (l.val_span, r.val_span, l.inc, r.inc)
+ } else {
+ (r.val_span, l.val_span, r.inc, l.inc)
+ };
+ if l_inc {
+ return;
+ }
+ let (range_type, range_op) = if u_inc {
+ ("Range", "..")
+ } else {
+ ("RangeInclusive", "..=")
+ };
+ let mut applicability = Applicability::MachineApplicable;
+ let name = snippet_with_applicability(cx, l.name_span, "_", &mut applicability);
+ let lo = snippet_with_applicability(cx, l_span, "_", &mut applicability);
+ let hi = snippet_with_applicability(cx, u_span, "_", &mut applicability);
+ let space = if lo.ends_with('.') { " " } else { "" };
+ span_lint_and_sugg(
+ cx,
+ MANUAL_RANGE_CONTAINS,
+ span,
+ &format!("manual `!{}::contains` implementation", range_type),
+ "use",
+ format!("!({}{}{}{}).contains(&{})", lo, space, range_op, hi, name),
+ applicability,
+ );
+ }
+ }
++
++ // If the LHS is the same operator, we have to recurse to get the "real" RHS, since they have
++ // the same operator precedence
++ if_chain! {
++ if let ExprKind::Binary(ref lhs_op, _left, new_lhs) = left.kind;
++ if op == lhs_op.node;
++ let new_span = Span::new(new_lhs.span.lo(), right.span.hi(), expr.span.ctxt(), expr.span.parent());
++ if let Some(snip) = &snippet_opt(cx, new_span);
++ // Do not continue if we have mismatched number of parens, otherwise the suggestion is wrong
++ if snip.matches('(').count() == snip.matches(')').count();
++ then {
++ check_possible_range_contains(cx, op, new_lhs, right, expr, new_span);
++ }
++ }
+}
+
+struct RangeBounds<'a> {
+ val: Constant,
+ expr: &'a Expr<'a>,
+ id: HirId,
+ name_span: Span,
+ val_span: Span,
+ ord: Ordering,
+ inc: bool,
+}
+
+// Takes a binary expression such as x <= 2 as input
+// Breaks apart into various pieces, such as the value of the number,
+// hir id of the variable, and direction/inclusiveness of the operator
+fn check_range_bounds<'a>(cx: &'a LateContext<'_>, ex: &'a Expr<'_>) -> Option<RangeBounds<'a>> {
+ if let ExprKind::Binary(ref op, l, r) = ex.kind {
+ let (inclusive, ordering) = match op.node {
+ BinOpKind::Gt => (false, Ordering::Greater),
+ BinOpKind::Ge => (true, Ordering::Greater),
+ BinOpKind::Lt => (false, Ordering::Less),
+ BinOpKind::Le => (true, Ordering::Less),
+ _ => return None,
+ };
+ if let Some(id) = path_to_local(l) {
+ if let Some((c, _)) = constant(cx, cx.typeck_results(), r) {
+ return Some(RangeBounds {
+ val: c,
+ expr: r,
+ id,
+ name_span: l.span,
+ val_span: r.span,
+ ord: ordering,
+ inc: inclusive,
+ });
+ }
+ } else if let Some(id) = path_to_local(r) {
+ if let Some((c, _)) = constant(cx, cx.typeck_results(), l) {
+ return Some(RangeBounds {
+ val: c,
+ expr: l,
+ id,
+ name_span: r.span,
+ val_span: l.span,
+ ord: ordering.reverse(),
+ inc: inclusive,
+ });
+ }
+ }
+ }
+ None
+}
+
+fn check_range_zip_with_len(cx: &LateContext<'_>, path: &PathSegment<'_>, args: &[Expr<'_>], span: Span) {
+ if_chain! {
+ if path.ident.as_str() == "zip";
+ if let [iter, zip_arg] = args;
+ // `.iter()` call
+ if let ExprKind::MethodCall(iter_path, iter_args, _) = iter.kind;
+ if iter_path.ident.name == sym::iter;
+ // range expression in `.zip()` call: `0..x.len()`
+ if let Some(higher::Range { start: Some(start), end: Some(end), .. }) = higher::Range::hir(zip_arg);
+ if is_integer_const(cx, start, 0);
+ // `.len()` call
+ if let ExprKind::MethodCall(len_path, len_args, _) = end.kind;
+ if len_path.ident.name == sym::len && len_args.len() == 1;
+ // `.iter()` and `.len()` called on same `Path`
+ if let ExprKind::Path(QPath::Resolved(_, iter_path)) = iter_args[0].kind;
+ if let ExprKind::Path(QPath::Resolved(_, len_path)) = len_args[0].kind;
+ if SpanlessEq::new(cx).eq_path_segments(&iter_path.segments, &len_path.segments);
+ then {
+ span_lint(cx,
+ RANGE_ZIP_WITH_LEN,
+ span,
+ &format!("it is more idiomatic to use `{}.iter().enumerate()`",
+ snippet(cx, iter_args[0].span, "_"))
+ );
+ }
+ }
+}
+
+// exclusive range plus one: `x..(y+1)`
+fn check_exclusive_range_plus_one(cx: &LateContext<'_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let Some(higher::Range {
+ start,
+ end: Some(end),
+ limits: RangeLimits::HalfOpen
+ }) = higher::Range::hir(expr);
+ if let Some(y) = y_plus_one(cx, end);
+ then {
+ let span = if expr.span.from_expansion() {
+ expr.span
+ .ctxt()
+ .outer_expn_data()
+ .call_site
+ } else {
+ expr.span
+ };
+ span_lint_and_then(
+ cx,
+ RANGE_PLUS_ONE,
+ span,
+ "an inclusive range would be more readable",
+ |diag| {
+ let start = start.map_or(String::new(), |x| Sugg::hir(cx, x, "x").maybe_par().to_string());
+ let end = Sugg::hir(cx, y, "y").maybe_par();
+ if let Some(is_wrapped) = &snippet_opt(cx, span) {
+ if is_wrapped.starts_with('(') && is_wrapped.ends_with(')') {
+ diag.span_suggestion(
+ span,
+ "use",
+ format!("({}..={})", start, end),
+ Applicability::MaybeIncorrect,
+ );
+ } else {
+ diag.span_suggestion(
+ span,
+ "use",
+ format!("{}..={}", start, end),
+ Applicability::MachineApplicable, // snippet
+ );
+ }
+ }
+ },
+ );
+ }
+ }
+}
+
+// inclusive range minus one: `x..=(y-1)`
+fn check_inclusive_range_minus_one(cx: &LateContext<'_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let Some(higher::Range { start, end: Some(end), limits: RangeLimits::Closed }) = higher::Range::hir(expr);
+ if let Some(y) = y_minus_one(cx, end);
+ then {
+ span_lint_and_then(
+ cx,
+ RANGE_MINUS_ONE,
+ expr.span,
+ "an exclusive range would be more readable",
+ |diag| {
+ let start = start.map_or(String::new(), |x| Sugg::hir(cx, x, "x").maybe_par().to_string());
+ let end = Sugg::hir(cx, y, "y").maybe_par();
+ diag.span_suggestion(
+ expr.span,
+ "use",
+ format!("{}..{}", start, end),
+ Applicability::MachineApplicable, // snippet
+ );
+ },
+ );
+ }
+ }
+}
+
+fn check_reversed_empty_range(cx: &LateContext<'_>, expr: &Expr<'_>) {
+ fn inside_indexing_expr(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ matches!(
+ get_parent_expr(cx, expr),
+ Some(Expr {
+ kind: ExprKind::Index(..),
+ ..
+ })
+ )
+ }
+
+ fn is_for_loop_arg(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ let mut cur_expr = expr;
+ while let Some(parent_expr) = get_parent_expr(cx, cur_expr) {
+ match higher::ForLoop::hir(parent_expr) {
+ Some(higher::ForLoop { arg, .. }) if arg.hir_id == expr.hir_id => return true,
+ _ => cur_expr = parent_expr,
+ }
+ }
+
+ false
+ }
+
+ fn is_empty_range(limits: RangeLimits, ordering: Ordering) -> bool {
+ match limits {
+ RangeLimits::HalfOpen => ordering != Ordering::Less,
+ RangeLimits::Closed => ordering == Ordering::Greater,
+ }
+ }
+
+ if_chain! {
+ if let Some(higher::Range { start: Some(start), end: Some(end), limits }) = higher::Range::hir(expr);
+ let ty = cx.typeck_results().expr_ty(start);
+ if let ty::Int(_) | ty::Uint(_) = ty.kind();
+ if let Some((start_idx, _)) = constant(cx, cx.typeck_results(), start);
+ if let Some((end_idx, _)) = constant(cx, cx.typeck_results(), end);
+ if let Some(ordering) = Constant::partial_cmp(cx.tcx, ty, &start_idx, &end_idx);
+ if is_empty_range(limits, ordering);
+ then {
+ if inside_indexing_expr(cx, expr) {
+ // Avoid linting `N..N` as it has proven to be useful, see #5689 and #5628 ...
+ if ordering != Ordering::Equal {
+ span_lint(
+ cx,
+ REVERSED_EMPTY_RANGES,
+ expr.span,
+ "this range is reversed and using it to index a slice will panic at run-time",
+ );
+ }
+ // ... except in for loop arguments for backwards compatibility with `reverse_range_loop`
+ } else if ordering != Ordering::Equal || is_for_loop_arg(cx, expr) {
+ span_lint_and_then(
+ cx,
+ REVERSED_EMPTY_RANGES,
+ expr.span,
+ "this range is empty so it will yield no values",
+ |diag| {
+ if ordering != Ordering::Equal {
+ let start_snippet = snippet(cx, start.span, "_");
+ let end_snippet = snippet(cx, end.span, "_");
+ let dots = match limits {
+ RangeLimits::HalfOpen => "..",
+ RangeLimits::Closed => "..="
+ };
+
+ diag.span_suggestion(
+ expr.span,
+ "consider using the following if you are attempting to iterate over this \
+ range in reverse",
+ format!("({}{}{}).rev()", end_snippet, dots, start_snippet),
+ Applicability::MaybeIncorrect,
+ );
+ }
+ },
+ );
+ }
+ }
+ }
+}
+
+fn y_plus_one<'t>(cx: &LateContext<'_>, expr: &'t Expr<'_>) -> Option<&'t Expr<'t>> {
+ match expr.kind {
+ ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Add, ..
+ },
+ lhs,
+ rhs,
+ ) => {
+ if is_integer_const(cx, lhs, 1) {
+ Some(rhs)
+ } else if is_integer_const(cx, rhs, 1) {
+ Some(lhs)
+ } else {
+ None
+ }
+ },
+ _ => None,
+ }
+}
+
+fn y_minus_one<'t>(cx: &LateContext<'_>, expr: &'t Expr<'_>) -> Option<&'t Expr<'t>> {
+ match expr.kind {
+ ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Sub, ..
+ },
+ lhs,
+ rhs,
+ ) if is_integer_const(cx, rhs, 1) => Some(lhs),
+ _ => None,
+ }
+}
--- /dev/null
- /// Checks for `Arc::new` or `Rc::new` in `vec![elem; len]`
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::higher::VecArgs;
+use clippy_utils::last_path_segment;
+use clippy_utils::macros::root_macro_call_first_node;
++use clippy_utils::paths;
+use clippy_utils::source::{indent_of, snippet};
++use clippy_utils::ty::match_type;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind, QPath, TyKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::{sym, Span, Symbol};
+
+declare_clippy_lint! {
+ /// ### What it does
- /// This will create `elem` once and clone it `len` times - doing so with `Arc` or `Rc`
++ /// Checks for reference-counted pointers (`Arc`, `Rc`, `rc::Weak`, and `sync::Weak`)
++ /// in `vec![elem; len]`
+ ///
+ /// ### Why is this bad?
- ///
++ /// This will create `elem` once and clone it `len` times - doing so with `Arc`/`Rc`/`Weak`
+ /// is a bit misleading, as it will create references to the same pointer, rather
+ /// than different instances.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let v = vec![std::sync::Arc::new("some data".to_string()); 100];
+ /// // or
+ /// let v = vec![std::rc::Rc::new("some data".to_string()); 100];
+ /// ```
+ /// Use instead:
+ /// ```rust
- "initializing `Arc` or `Rc` in `vec![elem; len]`"
+ /// // Initialize each value separately:
+ /// let mut data = Vec::with_capacity(100);
+ /// for _ in 0..100 {
+ /// data.push(std::rc::Rc::new("some data".to_string()));
+ /// }
+ ///
+ /// // Or if you want clones of the same reference,
+ /// // Create the reference beforehand to clarify that
+ /// // it should be cloned for each value
+ /// let data = std::rc::Rc::new("some data".to_string());
+ /// let v = vec![data; 100];
+ /// ```
+ #[clippy::version = "1.62.0"]
+ pub RC_CLONE_IN_VEC_INIT,
+ suspicious,
- let Some(symbol) = new_reference_call(cx, elem) else { return; };
++ "initializing reference-counted pointer in `vec![elem; len]`"
+}
+declare_lint_pass!(RcCloneInVecInit => [RC_CLONE_IN_VEC_INIT]);
+
+impl LateLintPass<'_> for RcCloneInVecInit {
+ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
+ let Some(macro_call) = root_macro_call_first_node(cx, expr) else { return; };
+ let Some(VecArgs::Repeat(elem, len)) = VecArgs::hir(cx, expr) else { return; };
- emit_lint(cx, symbol, macro_call.span, elem, len);
++ let Some((symbol, func_span)) = ref_init(cx, elem) else { return; };
+
- fn elem_snippet(cx: &LateContext<'_>, elem: &Expr<'_>, symbol_name: &str) -> String {
- let elem_snippet = snippet(cx, elem.span, "..").to_string();
- if elem_snippet.contains('\n') {
- // This string must be found in `elem_snippet`, otherwise we won't be constructing
- // the snippet in the first place.
- let reference_creation = format!("{symbol_name}::new");
- let (code_until_reference_creation, _right) = elem_snippet.split_once(&reference_creation).unwrap();
-
- return format!("{code_until_reference_creation}{reference_creation}(..)");
- }
-
- elem_snippet
- }
-
++ emit_lint(cx, symbol, macro_call.span, elem, len, func_span);
+ }
+}
+
- fn emit_lint(cx: &LateContext<'_>, symbol: Symbol, lint_span: Span, elem: &Expr<'_>, len: &Expr<'_>) {
+fn loop_init_suggestion(elem: &str, len: &str, indent: &str) -> String {
+ format!(
+ r#"{{
+{indent} let mut v = Vec::with_capacity({len});
+{indent} (0..{len}).for_each(|_| v.push({elem}));
+{indent} v
+{indent}}}"#
+ )
+}
+
+fn extract_suggestion(elem: &str, len: &str, indent: &str) -> String {
+ format!(
+ "{{
+{indent} let data = {elem};
+{indent} vec![data; {len}]
+{indent}}}"
+ )
+}
+
- &format!("calling `{symbol_name}::new` in `vec![elem; len]`"),
++fn emit_lint(cx: &LateContext<'_>, symbol: Symbol, lint_span: Span, elem: &Expr<'_>, len: &Expr<'_>, func_span: Span) {
+ let symbol_name = symbol.as_str();
+
+ span_lint_and_then(
+ cx,
+ RC_CLONE_IN_VEC_INIT,
+ lint_span,
- let elem_snippet = elem_snippet(cx, elem, symbol_name);
++ "initializing a reference-counted pointer in `vec![elem; len]`",
+ |diag| {
+ let len_snippet = snippet(cx, len.span, "..");
- Applicability::Unspecified,
++ let elem_snippet = format!("{}(..)", snippet(cx, elem.span.with_hi(func_span.hi()), ".."));
+ let indentation = " ".repeat(indent_of(cx, lint_span).unwrap_or(0));
+ let loop_init_suggestion = loop_init_suggestion(&elem_snippet, len_snippet.as_ref(), &indentation);
+ let extract_suggestion = extract_suggestion(&elem_snippet, len_snippet.as_ref(), &indentation);
+
+ diag.note(format!("each element will point to the same `{symbol_name}` instance"));
+ diag.span_suggestion(
+ lint_span,
+ format!("consider initializing each `{symbol_name}` element individually"),
+ loop_init_suggestion,
- Applicability::Unspecified,
++ Applicability::HasPlaceholders,
+ );
+ diag.span_suggestion(
+ lint_span,
+ format!(
+ "or if this is intentional, consider extracting the `{symbol_name}` initialization to a variable"
+ ),
+ extract_suggestion,
- /// Checks whether the given `expr` is a call to `Arc::new` or `Rc::new`
- fn new_reference_call(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<Symbol> {
++ Applicability::HasPlaceholders,
+ );
+ },
+ );
+}
+
- if last_path_segment(func_path).ident.name == sym::new;
++/// Checks whether the given `expr` is a call to `Arc::new`, `Rc::new`, or evaluates to a `Weak`
++fn ref_init(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<(Symbol, Span)> {
+ if_chain! {
+ if let ExprKind::Call(func, _args) = expr.kind;
+ if let ExprKind::Path(ref func_path @ QPath::TypeRelative(ty, _)) = func.kind;
+ if let TyKind::Path(ref ty_path) = ty.kind;
+ if let Some(def_id) = cx.qpath_res(ty_path, ty.hir_id).opt_def_id();
- return cx.tcx.get_diagnostic_name(def_id).filter(|symbol| symbol == &sym::Arc || symbol == &sym::Rc);
+
+ then {
++ if last_path_segment(func_path).ident.name == sym::new
++ && let Some(symbol) = cx
++ .tcx
++ .get_diagnostic_name(def_id)
++ .filter(|symbol| symbol == &sym::Arc || symbol == &sym::Rc) {
++ return Some((symbol, func.span));
++ }
++
++ let ty_path = cx.typeck_results().expr_ty(expr);
++ if match_type(cx, ty_path, &paths::WEAK_RC) || match_type(cx, ty_path, &paths::WEAK_ARC) {
++ return Some((Symbol::intern("Weak"), func.span));
++ }
+ }
+ }
+
+ None
+}
--- /dev/null
- if let ty::FnDef(def_id, _) = *func.ty(&*mir, cx.tcx).kind();
- if let (inner_ty, 1) = walk_ptrs_ty_depth(args[0].ty(&*mir, cx.tcx));
+use clippy_utils::diagnostics::{span_lint_hir, span_lint_hir_and_then};
+use clippy_utils::source::snippet_opt;
+use clippy_utils::ty::{has_drop, is_copy, is_type_diagnostic_item, walk_ptrs_ty_depth};
+use clippy_utils::{fn_has_unsatisfiable_preds, match_def_path, paths};
+use if_chain::if_chain;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::FnKind;
+use rustc_hir::{def_id, Body, FnDecl, HirId};
+use rustc_index::bit_set::{BitSet, HybridBitSet};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::mir::{
+ self, traversal,
+ visit::{MutatingUseContext, NonMutatingUseContext, PlaceContext, Visitor as _},
+ Mutability,
+};
+use rustc_middle::ty::{self, fold::TypeVisitor, Ty};
+use rustc_mir_dataflow::{Analysis, AnalysisDomain, CallReturnPlaces, GenKill, GenKillAnalysis, ResultsCursor};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::{BytePos, Span};
+use rustc_span::sym;
+use std::ops::ControlFlow;
+
+macro_rules! unwrap_or_continue {
+ ($x:expr) => {
+ match $x {
+ Some(x) => x,
+ None => continue,
+ }
+ };
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for a redundant `clone()` (and its relatives) which clones an owned
+ /// value that is going to be dropped without further use.
+ ///
+ /// ### Why is this bad?
+ /// It is not always possible for the compiler to eliminate useless
+ /// allocations and deallocations generated by redundant `clone()`s.
+ ///
+ /// ### Known problems
+ /// False-negatives: analysis performed by this lint is conservative and limited.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::path::Path;
+ /// # #[derive(Clone)]
+ /// # struct Foo;
+ /// # impl Foo {
+ /// # fn new() -> Self { Foo {} }
+ /// # }
+ /// # fn call(x: Foo) {}
+ /// {
+ /// let x = Foo::new();
+ /// call(x.clone());
+ /// call(x.clone()); // this can just pass `x`
+ /// }
+ ///
+ /// ["lorem", "ipsum"].join(" ").to_string();
+ ///
+ /// Path::new("/a/b").join("c").to_path_buf();
+ /// ```
+ #[clippy::version = "1.32.0"]
+ pub REDUNDANT_CLONE,
+ perf,
+ "`clone()` of an owned value that is going to be dropped immediately"
+}
+
+declare_lint_pass!(RedundantClone => [REDUNDANT_CLONE]);
+
+impl<'tcx> LateLintPass<'tcx> for RedundantClone {
+ #[expect(clippy::too_many_lines)]
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ _: FnKind<'tcx>,
+ _: &'tcx FnDecl<'_>,
+ body: &'tcx Body<'_>,
+ _: Span,
+ _: HirId,
+ ) {
+ let def_id = cx.tcx.hir().body_owner_def_id(body.id());
+
+ // Building MIR for `fn`s with unsatisfiable preds results in ICE.
+ if fn_has_unsatisfiable_preds(cx, def_id.to_def_id()) {
+ return;
+ }
+
+ let mir = cx.tcx.optimized_mir(def_id.to_def_id());
+
+ let possible_origin = {
+ let mut vis = PossibleOriginVisitor::new(mir);
+ vis.visit_body(mir);
+ vis.into_map(cx)
+ };
+ let maybe_storage_live_result = MaybeStorageLive
+ .into_engine(cx.tcx, mir)
+ .pass_name("redundant_clone")
+ .iterate_to_fixpoint()
+ .into_results_cursor(mir);
+ let mut possible_borrower = {
+ let mut vis = PossibleBorrowerVisitor::new(cx, mir, possible_origin);
+ vis.visit_body(mir);
+ vis.into_map(cx, maybe_storage_live_result)
+ };
+
+ for (bb, bbdata) in mir.basic_blocks().iter_enumerated() {
+ let terminator = bbdata.terminator();
+
+ if terminator.source_info.span.from_expansion() {
+ continue;
+ }
+
+ // Give up on loops
+ if terminator.successors().any(|s| s == bb) {
+ continue;
+ }
+
+ let (fn_def_id, arg, arg_ty, clone_ret) =
+ unwrap_or_continue!(is_call_with_ref_arg(cx, mir, &terminator.kind));
+
+ let from_borrow = match_def_path(cx, fn_def_id, &paths::CLONE_TRAIT_METHOD)
+ || match_def_path(cx, fn_def_id, &paths::TO_OWNED_METHOD)
+ || (match_def_path(cx, fn_def_id, &paths::TO_STRING_METHOD)
+ && is_type_diagnostic_item(cx, arg_ty, sym::String));
+
+ let from_deref = !from_borrow
+ && (match_def_path(cx, fn_def_id, &paths::PATH_TO_PATH_BUF)
+ || match_def_path(cx, fn_def_id, &paths::OS_STR_TO_OS_STRING));
+
+ if !from_borrow && !from_deref {
+ continue;
+ }
+
+ if let ty::Adt(def, _) = arg_ty.kind() {
+ if def.is_manually_drop() {
+ continue;
+ }
+ }
+
+ // `{ arg = &cloned; clone(move arg); }` or `{ arg = &cloned; to_path_buf(arg); }`
+ let (cloned, cannot_move_out) = unwrap_or_continue!(find_stmt_assigns_to(cx, mir, arg, from_borrow, bb));
+
+ let loc = mir::Location {
+ block: bb,
+ statement_index: bbdata.statements.len(),
+ };
+
+ // `Local` to be cloned, and a local of `clone` call's destination
+ let (local, ret_local) = if from_borrow {
+ // `res = clone(arg)` can be turned into `res = move arg;`
+ // if `arg` is the only borrow of `cloned` at this point.
+
+ if cannot_move_out || !possible_borrower.only_borrowers(&[arg], cloned, loc) {
+ continue;
+ }
+
+ (cloned, clone_ret)
+ } else {
+ // `arg` is a reference as it is `.deref()`ed in the previous block.
+ // Look into the predecessor block and find out the source of deref.
+
+ let ps = &mir.predecessors()[bb];
+ if ps.len() != 1 {
+ continue;
+ }
+ let pred_terminator = mir[ps[0]].terminator();
+
+ // receiver of the `deref()` call
+ let (pred_arg, deref_clone_ret) = if_chain! {
+ if let Some((pred_fn_def_id, pred_arg, pred_arg_ty, res)) =
+ is_call_with_ref_arg(cx, mir, &pred_terminator.kind);
+ if res == cloned;
+ if cx.tcx.is_diagnostic_item(sym::deref_method, pred_fn_def_id);
+ if is_type_diagnostic_item(cx, pred_arg_ty, sym::PathBuf)
+ || is_type_diagnostic_item(cx, pred_arg_ty, sym::OsString);
+ then {
+ (pred_arg, res)
+ } else {
+ continue;
+ }
+ };
+
+ let (local, cannot_move_out) =
+ unwrap_or_continue!(find_stmt_assigns_to(cx, mir, pred_arg, true, ps[0]));
+ let loc = mir::Location {
+ block: bb,
+ statement_index: mir.basic_blocks()[bb].statements.len(),
+ };
+
+ // This can be turned into `res = move local` if `arg` and `cloned` are not borrowed
+ // at the last statement:
+ //
+ // ```
+ // pred_arg = &local;
+ // cloned = deref(pred_arg);
+ // arg = &cloned;
+ // StorageDead(pred_arg);
+ // res = to_path_buf(cloned);
+ // ```
+ if cannot_move_out || !possible_borrower.only_borrowers(&[arg, cloned], local, loc) {
+ continue;
+ }
+
+ (local, deref_clone_ret)
+ };
+
+ let clone_usage = if local == ret_local {
+ CloneUsage {
+ cloned_used: false,
+ cloned_consume_or_mutate_loc: None,
+ clone_consumed_or_mutated: true,
+ }
+ } else {
+ let clone_usage = visit_clone_usage(local, ret_local, mir, bb);
+ if clone_usage.cloned_used && clone_usage.clone_consumed_or_mutated {
+ // cloned value is used, and the clone is modified or moved
+ continue;
+ } else if let Some(loc) = clone_usage.cloned_consume_or_mutate_loc {
+ // cloned value is mutated, and the clone is alive.
+ if possible_borrower.local_is_alive_at(ret_local, loc) {
+ continue;
+ }
+ }
+ clone_usage
+ };
+
+ let span = terminator.source_info.span;
+ let scope = terminator.source_info.scope;
+ let node = mir.source_scopes[scope]
+ .local_data
+ .as_ref()
+ .assert_crate_local()
+ .lint_root;
+
+ if_chain! {
+ if let Some(snip) = snippet_opt(cx, span);
+ if let Some(dot) = snip.rfind('.');
+ then {
+ let sugg_span = span.with_lo(
+ span.lo() + BytePos(u32::try_from(dot).unwrap())
+ );
+ let mut app = Applicability::MaybeIncorrect;
+
+ let call_snip = &snip[dot + 1..];
+ // Machine applicable when `call_snip` looks like `foobar()`
+ if let Some(call_snip) = call_snip.strip_suffix("()").map(str::trim) {
+ if call_snip.as_bytes().iter().all(|b| b.is_ascii_alphabetic() || *b == b'_') {
+ app = Applicability::MachineApplicable;
+ }
+ }
+
+ span_lint_hir_and_then(cx, REDUNDANT_CLONE, node, sugg_span, "redundant clone", |diag| {
+ diag.span_suggestion(
+ sugg_span,
+ "remove this",
+ String::new(),
+ app,
+ );
+ if clone_usage.cloned_used {
+ diag.span_note(
+ span,
+ "cloned value is neither consumed nor mutated",
+ );
+ } else {
+ diag.span_note(
+ span.with_hi(span.lo() + BytePos(u32::try_from(dot).unwrap())),
+ "this value is dropped without further use",
+ );
+ }
+ });
+ } else {
+ span_lint_hir(cx, REDUNDANT_CLONE, node, span, "redundant clone");
+ }
+ }
+ }
+ }
+}
+
+/// If `kind` is `y = func(x: &T)` where `T: !Copy`, returns `(DefId of func, x, T, y)`.
+fn is_call_with_ref_arg<'tcx>(
+ cx: &LateContext<'tcx>,
+ mir: &'tcx mir::Body<'tcx>,
+ kind: &'tcx mir::TerminatorKind<'tcx>,
+) -> Option<(def_id::DefId, mir::Local, Ty<'tcx>, mir::Local)> {
+ if_chain! {
+ if let mir::TerminatorKind::Call { func, args, destination, .. } = kind;
+ if args.len() == 1;
+ if let mir::Operand::Move(mir::Place { local, .. }) = &args[0];
- match (by_ref, &*rvalue) {
++ if let ty::FnDef(def_id, _) = *func.ty(mir, cx.tcx).kind();
++ if let (inner_ty, 1) = walk_ptrs_ty_depth(args[0].ty(mir, cx.tcx));
+ if !is_copy(cx, inner_ty);
+ then {
+ Some((def_id, *local, inner_ty, destination.as_local()?))
+ } else {
+ None
+ }
+ }
+}
+
+type CannotMoveOut = bool;
+
+/// Finds the first `to = (&)from`, and returns
+/// ``Some((from, whether `from` cannot be moved out))``.
+fn find_stmt_assigns_to<'tcx>(
+ cx: &LateContext<'tcx>,
+ mir: &mir::Body<'tcx>,
+ to_local: mir::Local,
+ by_ref: bool,
+ bb: mir::BasicBlock,
+) -> Option<(mir::Local, CannotMoveOut)> {
+ let rvalue = mir.basic_blocks()[bb].statements.iter().rev().find_map(|stmt| {
+ if let mir::StatementKind::Assign(box (mir::Place { local, .. }, v)) = &stmt.kind {
+ return if *local == to_local { Some(v) } else { None };
+ }
+
+ None
+ })?;
+
++ match (by_ref, rvalue) {
+ (true, mir::Rvalue::Ref(_, _, place)) | (false, mir::Rvalue::Use(mir::Operand::Copy(place))) => {
+ Some(base_local_and_movability(cx, mir, *place))
+ },
+ (false, mir::Rvalue::Ref(_, _, place)) => {
+ if let [mir::ProjectionElem::Deref] = place.as_ref().projection {
+ Some(base_local_and_movability(cx, mir, *place))
+ } else {
+ None
+ }
+ },
+ _ => None,
+ }
+}
+
+/// Extracts and returns the undermost base `Local` of given `place`. Returns `place` itself
+/// if it is already a `Local`.
+///
+/// Also reports whether given `place` cannot be moved out.
+fn base_local_and_movability<'tcx>(
+ cx: &LateContext<'tcx>,
+ mir: &mir::Body<'tcx>,
+ place: mir::Place<'tcx>,
+) -> (mir::Local, CannotMoveOut) {
+ use rustc_middle::mir::PlaceRef;
+
+ // Dereference. You cannot move things out from a borrowed value.
+ let mut deref = false;
+ // Accessing a field of an ADT that has `Drop`. Moving the field out will cause E0509.
+ let mut field = false;
+ // If projection is a slice index then clone can be removed only if the
+ // underlying type implements Copy
+ let mut slice = false;
+
+ let PlaceRef { local, mut projection } = place.as_ref();
+ while let [base @ .., elem] = projection {
+ projection = base;
+ deref |= matches!(elem, mir::ProjectionElem::Deref);
+ field |= matches!(elem, mir::ProjectionElem::Field(..))
+ && has_drop(cx, mir::Place::ty_from(local, projection, &mir.local_decls, cx.tcx).ty);
+ slice |= matches!(elem, mir::ProjectionElem::Index(..))
+ && !is_copy(cx, mir::Place::ty_from(local, projection, &mir.local_decls, cx.tcx).ty);
+ }
+
+ (local, deref || field || slice)
+}
+
+#[derive(Default)]
+struct CloneUsage {
+ /// Whether the cloned value is used after the clone.
+ cloned_used: bool,
+ /// The first location where the cloned value is consumed or mutated, if any.
+ cloned_consume_or_mutate_loc: Option<mir::Location>,
+ /// Whether the clone value is mutated.
+ clone_consumed_or_mutated: bool,
+}
+fn visit_clone_usage(cloned: mir::Local, clone: mir::Local, mir: &mir::Body<'_>, bb: mir::BasicBlock) -> CloneUsage {
+ struct V {
+ cloned: mir::Local,
+ clone: mir::Local,
+ result: CloneUsage,
+ }
+ impl<'tcx> mir::visit::Visitor<'tcx> for V {
+ fn visit_basic_block_data(&mut self, block: mir::BasicBlock, data: &mir::BasicBlockData<'tcx>) {
+ let statements = &data.statements;
+ for (statement_index, statement) in statements.iter().enumerate() {
+ self.visit_statement(statement, mir::Location { block, statement_index });
+ }
+
+ self.visit_terminator(
+ data.terminator(),
+ mir::Location {
+ block,
+ statement_index: statements.len(),
+ },
+ );
+ }
+
+ fn visit_place(&mut self, place: &mir::Place<'tcx>, ctx: PlaceContext, loc: mir::Location) {
+ let local = place.local;
+
+ if local == self.cloned
+ && !matches!(
+ ctx,
+ PlaceContext::MutatingUse(MutatingUseContext::Drop) | PlaceContext::NonUse(_)
+ )
+ {
+ self.result.cloned_used = true;
+ self.result.cloned_consume_or_mutate_loc = self.result.cloned_consume_or_mutate_loc.or_else(|| {
+ matches!(
+ ctx,
+ PlaceContext::NonMutatingUse(NonMutatingUseContext::Move)
+ | PlaceContext::MutatingUse(MutatingUseContext::Borrow)
+ )
+ .then(|| loc)
+ });
+ } else if local == self.clone {
+ match ctx {
+ PlaceContext::NonMutatingUse(NonMutatingUseContext::Move)
+ | PlaceContext::MutatingUse(MutatingUseContext::Borrow) => {
+ self.result.clone_consumed_or_mutated = true;
+ },
+ _ => {},
+ }
+ }
+ }
+ }
+
+ let init = CloneUsage {
+ cloned_used: false,
+ cloned_consume_or_mutate_loc: None,
+ // Consider non-temporary clones consumed.
+ // TODO: Actually check for mutation of non-temporaries.
+ clone_consumed_or_mutated: mir.local_kind(clone) != mir::LocalKind::Temp,
+ };
+ traversal::ReversePostorder::new(mir, bb)
+ .skip(1)
+ .fold(init, |usage, (tbb, tdata)| {
+ // Short-circuit
+ if (usage.cloned_used && usage.clone_consumed_or_mutated) ||
+ // Give up on loops
+ tdata.terminator().successors().any(|s| s == bb)
+ {
+ return CloneUsage {
+ cloned_used: true,
+ clone_consumed_or_mutated: true,
+ ..usage
+ };
+ }
+
+ let mut v = V {
+ cloned,
+ clone,
+ result: usage,
+ };
+ v.visit_basic_block_data(tbb, tdata);
+ v.result
+ })
+}
+
+/// Determines liveness of each local purely based on `StorageLive`/`Dead`.
+#[derive(Copy, Clone)]
+struct MaybeStorageLive;
+
+impl<'tcx> AnalysisDomain<'tcx> for MaybeStorageLive {
+ type Domain = BitSet<mir::Local>;
+ const NAME: &'static str = "maybe_storage_live";
+
+ fn bottom_value(&self, body: &mir::Body<'tcx>) -> Self::Domain {
+ // bottom = dead
+ BitSet::new_empty(body.local_decls.len())
+ }
+
+ fn initialize_start_block(&self, body: &mir::Body<'tcx>, state: &mut Self::Domain) {
+ for arg in body.args_iter() {
+ state.insert(arg);
+ }
+ }
+}
+
+impl<'tcx> GenKillAnalysis<'tcx> for MaybeStorageLive {
+ type Idx = mir::Local;
+
+ fn statement_effect(&self, trans: &mut impl GenKill<Self::Idx>, stmt: &mir::Statement<'tcx>, _: mir::Location) {
+ match stmt.kind {
+ mir::StatementKind::StorageLive(l) => trans.gen(l),
+ mir::StatementKind::StorageDead(l) => trans.kill(l),
+ _ => (),
+ }
+ }
+
+ fn terminator_effect(
+ &self,
+ _trans: &mut impl GenKill<Self::Idx>,
+ _terminator: &mir::Terminator<'tcx>,
+ _loc: mir::Location,
+ ) {
+ }
+
+ fn call_return_effect(
+ &self,
+ _trans: &mut impl GenKill<Self::Idx>,
+ _block: mir::BasicBlock,
+ _return_places: CallReturnPlaces<'_, 'tcx>,
+ ) {
+ // Nothing to do when a call returns successfully
+ }
+}
+
+/// Collects the possible borrowers of each local.
+/// For example, `b = &a; c = &a;` will make `b` and (transitively) `c`
+/// possible borrowers of `a`.
+struct PossibleBorrowerVisitor<'a, 'tcx> {
+ possible_borrower: TransitiveRelation,
+ body: &'a mir::Body<'tcx>,
+ cx: &'a LateContext<'tcx>,
+ possible_origin: FxHashMap<mir::Local, HybridBitSet<mir::Local>>,
+}
+
+impl<'a, 'tcx> PossibleBorrowerVisitor<'a, 'tcx> {
+ fn new(
+ cx: &'a LateContext<'tcx>,
+ body: &'a mir::Body<'tcx>,
+ possible_origin: FxHashMap<mir::Local, HybridBitSet<mir::Local>>,
+ ) -> Self {
+ Self {
+ possible_borrower: TransitiveRelation::default(),
+ cx,
+ body,
+ possible_origin,
+ }
+ }
+
+ fn into_map(
+ self,
+ cx: &LateContext<'tcx>,
+ maybe_live: ResultsCursor<'tcx, 'tcx, MaybeStorageLive>,
+ ) -> PossibleBorrowerMap<'a, 'tcx> {
+ let mut map = FxHashMap::default();
+ for row in (1..self.body.local_decls.len()).map(mir::Local::from_usize) {
+ if is_copy(cx, self.body.local_decls[row].ty) {
+ continue;
+ }
+
+ let mut borrowers = self.possible_borrower.reachable_from(row, self.body.local_decls.len());
+ borrowers.remove(mir::Local::from_usize(0));
+ if !borrowers.is_empty() {
+ map.insert(row, borrowers);
+ }
+ }
+
+ let bs = BitSet::new_empty(self.body.local_decls.len());
+ PossibleBorrowerMap {
+ map,
+ maybe_live,
+ bitset: (bs.clone(), bs),
+ }
+ }
+}
+
+impl<'a, 'tcx> mir::visit::Visitor<'tcx> for PossibleBorrowerVisitor<'a, 'tcx> {
+ fn visit_assign(&mut self, place: &mir::Place<'tcx>, rvalue: &mir::Rvalue<'_>, _location: mir::Location) {
+ let lhs = place.local;
+ match rvalue {
+ mir::Rvalue::Ref(_, _, borrowed) => {
+ self.possible_borrower.add(borrowed.local, lhs);
+ },
+ other => {
+ if ContainsRegion
+ .visit_ty(place.ty(&self.body.local_decls, self.cx.tcx).ty)
+ .is_continue()
+ {
+ return;
+ }
+ rvalue_locals(other, |rhs| {
+ if lhs != rhs {
+ self.possible_borrower.add(rhs, lhs);
+ }
+ });
+ },
+ }
+ }
+
+ fn visit_terminator(&mut self, terminator: &mir::Terminator<'_>, _loc: mir::Location) {
+ if let mir::TerminatorKind::Call {
+ args,
+ destination: mir::Place { local: dest, .. },
+ ..
+ } = &terminator.kind
+ {
+ // TODO add doc
+ // If the call returns something with lifetimes,
+ // let's conservatively assume the returned value contains lifetime of all the arguments.
+ // For example, given `let y: Foo<'a> = foo(x)`, `y` is considered to be a possible borrower of `x`.
+
+ let mut immutable_borrowers = vec![];
+ let mut mutable_borrowers = vec![];
+
+ for op in args {
+ match op {
+ mir::Operand::Copy(p) | mir::Operand::Move(p) => {
+ if let ty::Ref(_, _, Mutability::Mut) = self.body.local_decls[p.local].ty.kind() {
+ mutable_borrowers.push(p.local);
+ } else {
+ immutable_borrowers.push(p.local);
+ }
+ },
+ mir::Operand::Constant(..) => (),
+ }
+ }
+
+ let mut mutable_variables: Vec<mir::Local> = mutable_borrowers
+ .iter()
+ .filter_map(|r| self.possible_origin.get(r))
+ .flat_map(HybridBitSet::iter)
+ .collect();
+
+ if ContainsRegion.visit_ty(self.body.local_decls[*dest].ty).is_break() {
+ mutable_variables.push(*dest);
+ }
+
+ for y in mutable_variables {
+ for x in &immutable_borrowers {
+ self.possible_borrower.add(*x, y);
+ }
+ for x in &mutable_borrowers {
+ self.possible_borrower.add(*x, y);
+ }
+ }
+ }
+ }
+}
+
+/// Collect possible borrowed for every `&mut` local.
+/// For example, `_1 = &mut _2` generate _1: {_2,...}
+/// Known Problems: not sure all borrowed are tracked
+struct PossibleOriginVisitor<'a, 'tcx> {
+ possible_origin: TransitiveRelation,
+ body: &'a mir::Body<'tcx>,
+}
+
+impl<'a, 'tcx> PossibleOriginVisitor<'a, 'tcx> {
+ fn new(body: &'a mir::Body<'tcx>) -> Self {
+ Self {
+ possible_origin: TransitiveRelation::default(),
+ body,
+ }
+ }
+
+ fn into_map(self, cx: &LateContext<'tcx>) -> FxHashMap<mir::Local, HybridBitSet<mir::Local>> {
+ let mut map = FxHashMap::default();
+ for row in (1..self.body.local_decls.len()).map(mir::Local::from_usize) {
+ if is_copy(cx, self.body.local_decls[row].ty) {
+ continue;
+ }
+
+ let mut borrowers = self.possible_origin.reachable_from(row, self.body.local_decls.len());
+ borrowers.remove(mir::Local::from_usize(0));
+ if !borrowers.is_empty() {
+ map.insert(row, borrowers);
+ }
+ }
+ map
+ }
+}
+
+impl<'a, 'tcx> mir::visit::Visitor<'tcx> for PossibleOriginVisitor<'a, 'tcx> {
+ fn visit_assign(&mut self, place: &mir::Place<'tcx>, rvalue: &mir::Rvalue<'_>, _location: mir::Location) {
+ let lhs = place.local;
+ match rvalue {
+ // Only consider `&mut`, which can modify origin place
+ mir::Rvalue::Ref(_, rustc_middle::mir::BorrowKind::Mut { .. }, borrowed) |
+ // _2: &mut _;
+ // _3 = move _2
+ mir::Rvalue::Use(mir::Operand::Move(borrowed)) |
+ // _3 = move _2 as &mut _;
+ mir::Rvalue::Cast(_, mir::Operand::Move(borrowed), _)
+ => {
+ self.possible_origin.add(lhs, borrowed.local);
+ },
+ _ => {},
+ }
+ }
+}
+
+struct ContainsRegion;
+
+impl TypeVisitor<'_> for ContainsRegion {
+ type BreakTy = ();
+
+ fn visit_region(&mut self, _: ty::Region<'_>) -> ControlFlow<Self::BreakTy> {
+ ControlFlow::BREAK
+ }
+}
+
+fn rvalue_locals(rvalue: &mir::Rvalue<'_>, mut visit: impl FnMut(mir::Local)) {
+ use rustc_middle::mir::Rvalue::{Aggregate, BinaryOp, Cast, CheckedBinaryOp, Repeat, UnaryOp, Use};
+
+ let mut visit_op = |op: &mir::Operand<'_>| match op {
+ mir::Operand::Copy(p) | mir::Operand::Move(p) => visit(p.local),
+ mir::Operand::Constant(..) => (),
+ };
+
+ match rvalue {
+ Use(op) | Repeat(op, _) | Cast(_, op, _) | UnaryOp(_, op) => visit_op(op),
+ Aggregate(_, ops) => ops.iter().for_each(visit_op),
+ BinaryOp(_, box (lhs, rhs)) | CheckedBinaryOp(_, box (lhs, rhs)) => {
+ visit_op(lhs);
+ visit_op(rhs);
+ },
+ _ => (),
+ }
+}
+
+/// Result of `PossibleBorrowerVisitor`.
+struct PossibleBorrowerMap<'a, 'tcx> {
+ /// Mapping `Local -> its possible borrowers`
+ map: FxHashMap<mir::Local, HybridBitSet<mir::Local>>,
+ maybe_live: ResultsCursor<'a, 'tcx, MaybeStorageLive>,
+ // Caches to avoid allocation of `BitSet` on every query
+ bitset: (BitSet<mir::Local>, BitSet<mir::Local>),
+}
+
+impl PossibleBorrowerMap<'_, '_> {
+ /// Returns true if the set of borrowers of `borrowed` living at `at` matches with `borrowers`.
+ fn only_borrowers(&mut self, borrowers: &[mir::Local], borrowed: mir::Local, at: mir::Location) -> bool {
+ self.maybe_live.seek_after_primary_effect(at);
+
+ self.bitset.0.clear();
+ let maybe_live = &mut self.maybe_live;
+ if let Some(bitset) = self.map.get(&borrowed) {
+ for b in bitset.iter().filter(move |b| maybe_live.contains(*b)) {
+ self.bitset.0.insert(b);
+ }
+ } else {
+ return false;
+ }
+
+ self.bitset.1.clear();
+ for b in borrowers {
+ self.bitset.1.insert(*b);
+ }
+
+ self.bitset.0 == self.bitset.1
+ }
+
+ fn local_is_alive_at(&mut self, local: mir::Local, at: mir::Location) -> bool {
+ self.maybe_live.seek_after_primary_effect(at);
+ self.maybe_live.contains(local)
+ }
+}
+
+#[derive(Default)]
+struct TransitiveRelation {
+ relations: FxHashMap<mir::Local, Vec<mir::Local>>,
+}
+impl TransitiveRelation {
+ fn add(&mut self, a: mir::Local, b: mir::Local) {
+ self.relations.entry(a).or_default().push(b);
+ }
+
+ fn reachable_from(&self, a: mir::Local, domain_size: usize) -> HybridBitSet<mir::Local> {
+ let mut seen = HybridBitSet::new_empty(domain_size);
+ let mut stack = vec![a];
+ while let Some(u) = stack.pop() {
+ if let Some(edges) = self.relations.get(&u) {
+ for &v in edges {
+ if seen.insert(v) {
+ stack.push(v);
+ }
+ }
+ }
+ }
+ seen
+ }
+}
--- /dev/null
- TyKind::Array(ref ty, _) => {
- self.visit_type(&*ty, cx, reason);
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::source::snippet;
+use clippy_utils::{meets_msrv, msrvs};
+use rustc_ast::ast::{Item, ItemKind, Ty, TyKind};
+use rustc_errors::Applicability;
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for constants and statics with an explicit `'static` lifetime.
+ ///
+ /// ### Why is this bad?
+ /// Adding `'static` to every reference can create very
+ /// complicated types.
+ ///
+ /// ### Example
+ /// ```ignore
+ /// const FOO: &'static [(&'static str, &'static str, fn(&Bar) -> bool)] =
+ /// &[...]
+ /// static FOO: &'static [(&'static str, &'static str, fn(&Bar) -> bool)] =
+ /// &[...]
+ /// ```
+ /// This code can be rewritten as
+ /// ```ignore
+ /// const FOO: &[(&str, &str, fn(&Bar) -> bool)] = &[...]
+ /// static FOO: &[(&str, &str, fn(&Bar) -> bool)] = &[...]
+ /// ```
+ #[clippy::version = "1.37.0"]
+ pub REDUNDANT_STATIC_LIFETIMES,
+ style,
+ "Using explicit `'static` lifetime for constants or statics when elision rules would allow omitting them."
+}
+
+pub struct RedundantStaticLifetimes {
+ msrv: Option<RustcVersion>,
+}
+
+impl RedundantStaticLifetimes {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self { msrv }
+ }
+}
+
+impl_lint_pass!(RedundantStaticLifetimes => [REDUNDANT_STATIC_LIFETIMES]);
+
+impl RedundantStaticLifetimes {
+ // Recursively visit types
+ fn visit_type(&mut self, ty: &Ty, cx: &EarlyContext<'_>, reason: &str) {
+ match ty.kind {
+ // Be careful of nested structures (arrays and tuples)
- self.visit_type(&*tup_ty, cx, reason);
++ TyKind::Array(ref ty, _) | TyKind::Slice(ref ty) => {
++ self.visit_type(ty, cx, reason);
+ },
+ TyKind::Tup(ref tup) => {
+ for tup_ty in tup {
- TyKind::Slice(ref ty) => {
- self.visit_type(ty, cx, reason);
- },
++ self.visit_type(tup_ty, cx, reason);
+ }
+ },
+ // This is what we are looking for !
+ TyKind::Rptr(ref optional_lifetime, ref borrow_type) => {
+ // Match the 'static lifetime
+ if let Some(lifetime) = *optional_lifetime {
+ match borrow_type.ty.kind {
+ TyKind::Path(..) | TyKind::Slice(..) | TyKind::Array(..) | TyKind::Tup(..) => {
+ if lifetime.ident.name == rustc_span::symbol::kw::StaticLifetime {
+ let snip = snippet(cx, borrow_type.ty.span, "<type>");
+ let sugg = format!("&{}", snip);
+ span_lint_and_then(
+ cx,
+ REDUNDANT_STATIC_LIFETIMES,
+ lifetime.ident.span,
+ reason,
+ |diag| {
+ diag.span_suggestion(
+ ty.span,
+ "consider removing `'static`",
+ sugg,
+ Applicability::MachineApplicable, //snippet
+ );
+ },
+ );
+ }
+ },
+ _ => {},
+ }
+ }
+ self.visit_type(&*borrow_type.ty, cx, reason);
+ },
+ _ => {},
+ }
+ }
+}
+
+impl EarlyLintPass for RedundantStaticLifetimes {
+ fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
+ if !meets_msrv(self.msrv, msrvs::STATIC_IN_CONST) {
+ return;
+ }
+
+ if !item.span.from_expansion() {
+ if let ItemKind::Const(_, ref var_type, _) = item.kind {
+ self.visit_type(var_type, cx, "constants have by default a `'static` lifetime");
+ // Don't check associated consts because `'static` cannot be elided on those (issue
+ // #2438)
+ }
+
+ if let ItemKind::Static(ref var_type, _, _) = item.kind {
+ self.visit_type(var_type, cx, "statics have by default a `'static` lifetime");
+ }
+ }
+ }
+
+ extract_msrv_attr!(EarlyContext);
+}
--- /dev/null
- use clippy_utils::source::snippet_opt;
+use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
- if in_external_macro(cx.tcx.sess, inner_span) || inner_span.from_expansion() {
- return;
- }
-
++use clippy_utils::source::{snippet_opt, snippet_with_context};
+use clippy_utils::{fn_def_id, path_to_local_id};
+use if_chain::if_chain;
+use rustc_ast::ast::Attribute;
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::{walk_expr, FnKind, Visitor};
+use rustc_hir::{Block, Body, Expr, ExprKind, FnDecl, HirId, MatchSource, PatKind, StmtKind};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::subst::GenericArgKind;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::hygiene::DesugaringKind;
+use rustc_span::source_map::Span;
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `let`-bindings, which are subsequently
+ /// returned.
+ ///
+ /// ### Why is this bad?
+ /// It is just extraneous code. Remove it to make your code
+ /// more rusty.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn foo() -> String {
+ /// let x = String::new();
+ /// x
+ /// }
+ /// ```
+ /// instead, use
+ /// ```
+ /// fn foo() -> String {
+ /// String::new()
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub LET_AND_RETURN,
+ style,
+ "creating a let-binding and then immediately returning it like `let x = expr; x` at the end of a block"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for return statements at the end of a block.
+ ///
+ /// ### Why is this bad?
+ /// Removing the `return` and semicolon will make the code
+ /// more rusty.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn foo(x: usize) -> usize {
+ /// return x;
+ /// }
+ /// ```
+ /// simplify to
+ /// ```rust
+ /// fn foo(x: usize) -> usize {
+ /// x
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NEEDLESS_RETURN,
+ style,
+ "using a return statement like `return expr;` where an expression would suffice"
+}
+
+#[derive(PartialEq, Eq, Copy, Clone)]
+enum RetReplacement {
+ Empty,
+ Block,
+ Unit,
+}
+
+declare_lint_pass!(Return => [LET_AND_RETURN, NEEDLESS_RETURN]);
+
+impl<'tcx> LateLintPass<'tcx> for Return {
+ fn check_block(&mut self, cx: &LateContext<'tcx>, block: &'tcx Block<'_>) {
+ // we need both a let-binding stmt and an expr
+ if_chain! {
+ if let Some(retexpr) = block.expr;
+ if let Some(stmt) = block.stmts.iter().last();
+ if let StmtKind::Local(local) = &stmt.kind;
+ if local.ty.is_none();
+ if cx.tcx.hir().attrs(local.hir_id).is_empty();
+ if let Some(initexpr) = &local.init;
+ if let PatKind::Binding(_, local_id, _, _) = local.pat.kind;
+ if path_to_local_id(retexpr, local_id);
+ if !last_statement_borrows(cx, initexpr);
+ if !in_external_macro(cx.sess(), initexpr.span);
+ if !in_external_macro(cx.sess(), retexpr.span);
+ if !local.span.from_expansion();
+ then {
+ span_lint_and_then(
+ cx,
+ LET_AND_RETURN,
+ retexpr.span,
+ "returning the result of a `let` binding from a block",
+ |err| {
+ err.span_label(local.span, "unnecessary `let` binding");
+
+ if let Some(mut snippet) = snippet_opt(cx, initexpr.span) {
+ if !cx.typeck_results().expr_adjustments(retexpr).is_empty() {
+ snippet.push_str(" as _");
+ }
+ err.multipart_suggestion(
+ "return the expression directly",
+ vec![
+ (local.span, String::new()),
+ (retexpr.span, snippet),
+ ],
+ Applicability::MachineApplicable,
+ );
+ } else {
+ err.span_help(initexpr.span, "this expression can be directly returned");
+ }
+ },
+ );
+ }
+ }
+ }
+
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ kind: FnKind<'tcx>,
+ _: &'tcx FnDecl<'tcx>,
+ body: &'tcx Body<'tcx>,
+ _: Span,
+ _: HirId,
+ ) {
+ match kind {
+ FnKind::Closure => {
+ // when returning without value in closure, replace this `return`
+ // with an empty block to prevent invalid suggestion (see #6501)
+ let replacement = if let ExprKind::Ret(None) = &body.value.kind {
+ RetReplacement::Block
+ } else {
+ RetReplacement::Empty
+ };
+ check_final_expr(cx, &body.value, Some(body.value.span), replacement);
+ },
+ FnKind::ItemFn(..) | FnKind::Method(..) => {
+ if let ExprKind::Block(block, _) = body.value.kind {
+ check_block_return(cx, block);
+ }
+ },
+ }
+ }
+}
+
+fn attr_is_cfg(attr: &Attribute) -> bool {
+ attr.meta_item_list().is_some() && attr.has_name(sym::cfg)
+}
+
+fn check_block_return<'tcx>(cx: &LateContext<'tcx>, block: &Block<'tcx>) {
+ if let Some(expr) = block.expr {
+ check_final_expr(cx, expr, Some(expr.span), RetReplacement::Empty);
+ } else if let Some(stmt) = block.stmts.iter().last() {
+ match stmt.kind {
+ StmtKind::Expr(expr) | StmtKind::Semi(expr) => {
+ check_final_expr(cx, expr, Some(stmt.span), RetReplacement::Empty);
+ },
+ _ => (),
+ }
+ }
+}
+
+fn check_final_expr<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx Expr<'tcx>,
+ span: Option<Span>,
+ replacement: RetReplacement,
+) {
+ match expr.kind {
+ // simple return is always "bad"
+ ExprKind::Ret(ref inner) => {
+ // allow `#[cfg(a)] return a; #[cfg(b)] return b;`
+ let attrs = cx.tcx.hir().attrs(expr.hir_id);
+ if !attrs.iter().any(attr_is_cfg) {
+ let borrows = inner.map_or(false, |inner| last_statement_borrows(cx, inner));
+ if !borrows {
+ emit_return_lint(
+ cx,
+ span.expect("`else return` is not possible"),
+ inner.as_ref().map(|i| i.span),
+ replacement,
+ );
+ }
+ }
+ },
+ // a whole block? check it!
+ ExprKind::Block(block, _) => {
+ check_block_return(cx, block);
+ },
+ ExprKind::If(_, then, else_clause_opt) => {
+ if let ExprKind::Block(ifblock, _) = then.kind {
+ check_block_return(cx, ifblock);
+ }
+ if let Some(else_clause) = else_clause_opt {
+ if expr.span.desugaring_kind() != Some(DesugaringKind::LetElse) {
+ check_final_expr(cx, else_clause, None, RetReplacement::Empty);
+ }
+ }
+ },
+ // a match expr, check all arms
+ // an if/if let expr, check both exprs
+ // note, if without else is going to be a type checking error anyways
+ // (except for unit type functions) so we don't match it
+ ExprKind::Match(_, arms, MatchSource::Normal) => {
+ for arm in arms.iter() {
+ check_final_expr(cx, arm.body, Some(arm.body.span), RetReplacement::Unit);
+ }
+ },
+ ExprKind::DropTemps(expr) => check_final_expr(cx, expr, None, RetReplacement::Empty),
+ _ => (),
+ }
+}
+
+fn emit_return_lint(cx: &LateContext<'_>, ret_span: Span, inner_span: Option<Span>, replacement: RetReplacement) {
+ if ret_span.from_expansion() {
+ return;
+ }
+ match inner_span {
+ Some(inner_span) => {
- if let Some(snippet) = snippet_opt(cx, inner_span) {
- diag.span_suggestion(ret_span, "remove `return`", snippet, Applicability::MachineApplicable);
- }
++ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_then(cx, NEEDLESS_RETURN, ret_span, "unneeded `return` statement", |diag| {
- if self.borrows {
++ let (snippet, _) = snippet_with_context(cx, inner_span, ret_span.ctxt(), "..", &mut applicability);
++ diag.span_suggestion(ret_span, "remove `return`", snippet, applicability);
+ });
+ },
+ None => match replacement {
+ RetReplacement::Empty => {
+ span_lint_and_sugg(
+ cx,
+ NEEDLESS_RETURN,
+ ret_span,
+ "unneeded `return` statement",
+ "remove `return`",
+ String::new(),
+ Applicability::MachineApplicable,
+ );
+ },
+ RetReplacement::Block => {
+ span_lint_and_sugg(
+ cx,
+ NEEDLESS_RETURN,
+ ret_span,
+ "unneeded `return` statement",
+ "replace `return` with an empty block",
+ "{}".to_string(),
+ Applicability::MachineApplicable,
+ );
+ },
+ RetReplacement::Unit => {
+ span_lint_and_sugg(
+ cx,
+ NEEDLESS_RETURN,
+ ret_span,
+ "unneeded `return` statement",
+ "replace `return` with a unit value",
+ "()".to_string(),
+ Applicability::MachineApplicable,
+ );
+ },
+ },
+ }
+}
+
+fn last_statement_borrows<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> bool {
+ let mut visitor = BorrowVisitor { cx, borrows: false };
+ walk_expr(&mut visitor, expr);
+ visitor.borrows
+}
+
+struct BorrowVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ borrows: bool,
+}
+
+impl<'tcx> Visitor<'tcx> for BorrowVisitor<'_, 'tcx> {
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
++ if self.borrows || expr.span.from_expansion() {
+ return;
+ }
+
+ if let Some(def_id) = fn_def_id(self.cx, expr) {
+ self.borrows = self
+ .cx
+ .tcx
+ .fn_sig(def_id)
+ .output()
+ .skip_binder()
+ .walk()
+ .any(|arg| matches!(arg.unpack(), GenericArgKind::Lifetime(_)));
+ }
+
+ walk_expr(self, expr);
+ }
+}
--- /dev/null
- use rustc_hir::{
- Block, Body, BodyOwnerKind, Expr, ExprKind, HirId, Let, Node, Pat, PatKind, QPath, UnOp,
- };
+use clippy_utils::diagnostics::span_lint_and_note;
+use clippy_utils::source::snippet;
+use clippy_utils::visitors::is_local_used;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_hir::def::Res;
+use rustc_hir::def_id::LocalDefId;
+use rustc_hir::hir_id::ItemLocalId;
- if !matches!(hir.body_owner_kind(hir.body_owner_def_id(body.id())), BodyOwnerKind::Closure)
- {
++use rustc_hir::{Block, Body, BodyOwnerKind, Expr, ExprKind, HirId, Let, Node, Pat, PatKind, QPath, UnOp};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::{Span, Symbol};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for bindings that shadow other bindings already in
+ /// scope, while just changing reference level or mutability.
+ ///
+ /// ### Why is this bad?
+ /// Not much, in fact it's a very common pattern in Rust
+ /// code. Still, some may opt to avoid it in their code base, they can set this
+ /// lint to `Warn`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let x = 1;
+ /// // Bad
+ /// let x = &x;
+ ///
+ /// // Good
+ /// let y = &x; // use different variable name
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub SHADOW_SAME,
+ restriction,
+ "rebinding a name to itself, e.g., `let mut x = &mut x`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for bindings that shadow other bindings already in
+ /// scope, while reusing the original value.
+ ///
+ /// ### Why is this bad?
+ /// Not too much, in fact it's a common pattern in Rust
+ /// code. Still, some argue that name shadowing like this hurts readability,
+ /// because a value may be bound to different things depending on position in
+ /// the code.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = 2;
+ /// let x = x + 1;
+ /// ```
+ /// use different variable name:
+ /// ```rust
+ /// let x = 2;
+ /// let y = x + 1;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub SHADOW_REUSE,
+ restriction,
+ "rebinding a name to an expression that re-uses the original value, e.g., `let x = x + 1`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for bindings that shadow other bindings already in
+ /// scope, either without an initialization or with one that does not even use
+ /// the original value.
+ ///
+ /// ### Why is this bad?
+ /// Name shadowing can hurt readability, especially in
+ /// large code bases, because it is easy to lose track of the active binding at
+ /// any place in the code. This can be alleviated by either giving more specific
+ /// names to bindings or introducing more scopes to contain the bindings.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let y = 1;
+ /// # let z = 2;
+ /// let x = y;
+ ///
+ /// // Bad
+ /// let x = z; // shadows the earlier binding
+ ///
+ /// // Good
+ /// let w = z; // use different variable name
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub SHADOW_UNRELATED,
+ restriction,
+ "rebinding a name without even using the original value"
+}
+
+#[derive(Default)]
+pub(crate) struct Shadow {
+ bindings: Vec<FxHashMap<Symbol, Vec<ItemLocalId>>>,
+}
+
+impl_lint_pass!(Shadow => [SHADOW_SAME, SHADOW_REUSE, SHADOW_UNRELATED]);
+
+impl<'tcx> LateLintPass<'tcx> for Shadow {
+ fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) {
+ let (id, ident) = match pat.kind {
+ PatKind::Binding(_, hir_id, ident, _) => (hir_id, ident),
+ _ => return,
+ };
+
+ if pat.span.desugaring_kind().is_some() {
+ return;
+ }
+
+ if ident.span.from_expansion() || ident.span.is_dummy() {
+ return;
+ }
+
+ let HirId { owner, local_id } = id;
+ // get (or insert) the list of items for this owner and symbol
+ let data = self.bindings.last_mut().unwrap();
+ let items_with_name = data.entry(ident.name).or_default();
+
+ // check other bindings with the same name, most recently seen first
+ for &prev in items_with_name.iter().rev() {
+ if prev == local_id {
+ // repeated binding in an `Or` pattern
+ return;
+ }
+
+ if is_shadow(cx, owner, prev, local_id) {
+ let prev_hir_id = HirId { owner, local_id: prev };
+ lint_shadow(cx, pat, prev_hir_id, ident.span);
+ // only lint against the "nearest" shadowed binding
+ break;
+ }
+ }
+ // store the binding
+ items_with_name.push(local_id);
+ }
+
+ fn check_body(&mut self, cx: &LateContext<'_>, body: &Body<'_>) {
+ let hir = cx.tcx.hir();
- if !matches!(hir.body_owner_kind(hir.body_owner_def_id(body.id())), BodyOwnerKind::Closure)
- {
++ if !matches!(
++ hir.body_owner_kind(hir.body_owner_def_id(body.id())),
++ BodyOwnerKind::Closure
++ ) {
+ self.bindings.push(FxHashMap::default());
+ }
+ }
+
+ fn check_body_post(&mut self, cx: &LateContext<'_>, body: &Body<'_>) {
+ let hir = cx.tcx.hir();
- fn is_shadow(
- cx: &LateContext<'_>,
- owner: LocalDefId,
- first: ItemLocalId,
- second: ItemLocalId,
- ) -> bool {
- let scope_tree = cx.tcx.region_scope_tree(owner);
- let first_scope = scope_tree.var_scope(first).unwrap();
- let second_scope = scope_tree.var_scope(second).unwrap();
- scope_tree.is_subscope_of(second_scope, first_scope)
++ if !matches!(
++ hir.body_owner_kind(hir.body_owner_def_id(body.id())),
++ BodyOwnerKind::Closure
++ ) {
+ self.bindings.pop();
+ }
+ }
+}
+
- }
++fn is_shadow(cx: &LateContext<'_>, owner: LocalDefId, first: ItemLocalId, second: ItemLocalId) -> bool {
++ let scope_tree = cx.tcx.region_scope_tree(owner.to_def_id());
++ if let Some(first_scope) = scope_tree.var_scope(first) {
++ if let Some(second_scope) = scope_tree.var_scope(second) {
++ return scope_tree.is_subscope_of(second_scope, first_scope);
++ }
++ }
++
++ false
+}
+
+fn lint_shadow(cx: &LateContext<'_>, pat: &Pat<'_>, shadowed: HirId, span: Span) {
+ let (lint, msg) = match find_init(cx, pat.hir_id) {
+ Some(expr) if is_self_shadow(cx, pat, expr, shadowed) => {
+ let msg = format!(
+ "`{}` is shadowed by itself in `{}`",
+ snippet(cx, pat.span, "_"),
+ snippet(cx, expr.span, "..")
+ );
+ (SHADOW_SAME, msg)
- }
++ },
+ Some(expr) if is_local_used(cx, expr, shadowed) => {
+ let msg = format!("`{}` is shadowed", snippet(cx, pat.span, "_"));
+ (SHADOW_REUSE, msg)
- let msg =
- format!("`{}` shadows a previous, unrelated binding", snippet(cx, pat.span, "_"));
++ },
+ _ => {
- }
++ let msg = format!("`{}` shadows a previous, unrelated binding", snippet(cx, pat.span, "_"));
+ (SHADOW_UNRELATED, msg)
- | ExprKind::Block(&Block { stmts: [], expr: Some(e), .. }, _)
++ },
+ };
+ span_lint_and_note(
+ cx,
+ lint,
+ span,
+ &msg,
+ Some(cx.tcx.hir().span(shadowed)),
+ "previous binding is here",
+ );
+}
+
+/// Returns true if the expression is a simple transformation of a local binding such as `&x`
+fn is_self_shadow(cx: &LateContext<'_>, pat: &Pat<'_>, mut expr: &Expr<'_>, hir_id: HirId) -> bool {
+ let hir = cx.tcx.hir();
+ let is_direct_binding = hir
+ .parent_iter(pat.hir_id)
+ .map_while(|(_id, node)| match node {
+ Node::Pat(pat) => Some(pat),
+ _ => None,
+ })
+ .all(|pat| matches!(pat.kind, PatKind::Ref(..) | PatKind::Or(_)));
+ if !is_direct_binding {
+ return false;
+ }
+ loop {
+ expr = match expr.kind {
+ ExprKind::Box(e)
+ | ExprKind::AddrOf(_, _, e)
++ | ExprKind::Block(
++ &Block {
++ stmts: [],
++ expr: Some(e),
++ ..
++ },
++ _,
++ )
+ | ExprKind::Unary(UnOp::Deref, e) => e,
+ ExprKind::Path(QPath::Resolved(None, path)) => break path.res == Res::Local(hir_id),
+ _ => break false,
+ }
+ }
+}
+
+/// Finds the "init" expression for a pattern: `let <pat> = <init>;` (or `if let`) or
+/// `match <init> { .., <pat> => .., .. }`
+fn find_init<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<&'tcx Expr<'tcx>> {
+ for (_, node) in cx.tcx.hir().parent_iter(hir_id) {
+ let init = match node {
+ Node::Arm(_) | Node::Pat(_) => continue,
+ Node::Expr(expr) => match expr.kind {
+ ExprKind::Match(e, _, _) | ExprKind::Let(&Let { init: e, .. }) => Some(e),
+ _ => None,
+ },
+ Node::Local(local) => local.init,
+ _ => None,
+ };
+ return init;
+ }
+ None
+}
--- /dev/null
- if METHODS.iter().any(|m| *m == &*method_ident);
+//! Lint on use of `size_of` or `size_of_val` of T in an expression
+//! expecting a count of T
+
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::{match_def_path, paths};
+use if_chain::if_chain;
+use rustc_hir::BinOpKind;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, Ty, TypeAndMut};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Detects expressions where
+ /// `size_of::<T>` or `size_of_val::<T>` is used as a
+ /// count of elements of type `T`
+ ///
+ /// ### Why is this bad?
+ /// These functions expect a count
+ /// of `T` and not a number of bytes
+ ///
+ /// ### Example
+ /// ```rust,no_run
+ /// # use std::ptr::copy_nonoverlapping;
+ /// # use std::mem::size_of;
+ /// const SIZE: usize = 128;
+ /// let x = [2u8; SIZE];
+ /// let mut y = [2u8; SIZE];
+ /// unsafe { copy_nonoverlapping(x.as_ptr(), y.as_mut_ptr(), size_of::<u8>() * SIZE) };
+ /// ```
+ #[clippy::version = "1.50.0"]
+ pub SIZE_OF_IN_ELEMENT_COUNT,
+ correctness,
+ "using `size_of::<T>` or `size_of_val::<T>` where a count of elements of `T` is expected"
+}
+
+declare_lint_pass!(SizeOfInElementCount => [SIZE_OF_IN_ELEMENT_COUNT]);
+
+fn get_size_of_ty<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, inverted: bool) -> Option<Ty<'tcx>> {
+ match expr.kind {
+ ExprKind::Call(count_func, _func_args) => {
+ if_chain! {
+ if !inverted;
+ if let ExprKind::Path(ref count_func_qpath) = count_func.kind;
+ if let Some(def_id) = cx.qpath_res(count_func_qpath, count_func.hir_id).opt_def_id();
+ if matches!(cx.tcx.get_diagnostic_name(def_id), Some(sym::mem_size_of | sym::mem_size_of_val));
+ then {
+ cx.typeck_results().node_substs(count_func.hir_id).types().next()
+ } else {
+ None
+ }
+ }
+ },
+ ExprKind::Binary(op, left, right) if BinOpKind::Mul == op.node => {
+ get_size_of_ty(cx, left, inverted).or_else(|| get_size_of_ty(cx, right, inverted))
+ },
+ ExprKind::Binary(op, left, right) if BinOpKind::Div == op.node => {
+ get_size_of_ty(cx, left, inverted).or_else(|| get_size_of_ty(cx, right, !inverted))
+ },
+ ExprKind::Cast(expr, _) => get_size_of_ty(cx, expr, inverted),
+ _ => None,
+ }
+}
+
+fn get_pointee_ty_and_count_expr<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx Expr<'_>,
+) -> Option<(Ty<'tcx>, &'tcx Expr<'tcx>)> {
+ const FUNCTIONS: [&[&str]; 8] = [
+ &paths::PTR_COPY_NONOVERLAPPING,
+ &paths::PTR_COPY,
+ &paths::PTR_WRITE_BYTES,
+ &paths::PTR_SWAP_NONOVERLAPPING,
+ &paths::PTR_SLICE_FROM_RAW_PARTS,
+ &paths::PTR_SLICE_FROM_RAW_PARTS_MUT,
+ &paths::SLICE_FROM_RAW_PARTS,
+ &paths::SLICE_FROM_RAW_PARTS_MUT,
+ ];
+ const METHODS: [&str; 11] = [
+ "write_bytes",
+ "copy_to",
+ "copy_from",
+ "copy_to_nonoverlapping",
+ "copy_from_nonoverlapping",
+ "add",
+ "wrapping_add",
+ "sub",
+ "wrapping_sub",
+ "offset",
+ "wrapping_offset",
+ ];
+
+ if_chain! {
+ // Find calls to ptr::{copy, copy_nonoverlapping}
+ // and ptr::{swap_nonoverlapping, write_bytes},
+ if let ExprKind::Call(func, [.., count]) = expr.kind;
+ if let ExprKind::Path(ref func_qpath) = func.kind;
+ if let Some(def_id) = cx.qpath_res(func_qpath, func.hir_id).opt_def_id();
+ if FUNCTIONS.iter().any(|func_path| match_def_path(cx, def_id, func_path));
+
+ // Get the pointee type
+ if let Some(pointee_ty) = cx.typeck_results().node_substs(func.hir_id).types().next();
+ then {
+ return Some((pointee_ty, count));
+ }
+ };
+ if_chain! {
+ // Find calls to copy_{from,to}{,_nonoverlapping} and write_bytes methods
+ if let ExprKind::MethodCall(method_path, [ptr_self, .., count], _) = expr.kind;
+ let method_ident = method_path.ident.as_str();
++ if METHODS.iter().any(|m| *m == method_ident);
+
+ // Get the pointee type
+ if let ty::RawPtr(TypeAndMut { ty: pointee_ty, .. }) =
+ cx.typeck_results().expr_ty(ptr_self).kind();
+ then {
+ return Some((*pointee_ty, count));
+ }
+ };
+ None
+}
+
+impl<'tcx> LateLintPass<'tcx> for SizeOfInElementCount {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ const HELP_MSG: &str = "use a count of elements instead of a count of bytes\
+ , it already gets multiplied by the size of the type";
+
+ const LINT_MSG: &str = "found a count of bytes \
+ instead of a count of elements of `T`";
+
+ if_chain! {
+ // Find calls to functions with an element count parameter and get
+ // the pointee type and count parameter expression
+ if let Some((pointee_ty, count_expr)) = get_pointee_ty_and_count_expr(cx, expr);
+
+ // Find a size_of call in the count parameter expression and
+ // check that it's the same type
+ if let Some(ty_used_for_size_of) = get_size_of_ty(cx, count_expr, false);
+ if pointee_ty == ty_used_for_size_of;
+ then {
+ span_lint_and_help(
+ cx,
+ SIZE_OF_IN_ELEMENT_COUNT,
+ count_expr.span,
+ LINT_MSG,
+ None,
+ HELP_MSG
+ );
+ }
+ };
+ }
+}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint_and_then;
++use clippy_utils::source::snippet_with_context;
++use clippy_utils::{match_def_path, path_def_id, paths};
++use rustc_errors::Applicability;
++use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability, UnOp};
++use rustc_lint::{LateContext, LateLintPass};
++use rustc_session::{declare_lint_pass, declare_tool_lint};
++use rustc_span::{Span, SyntaxContext};
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// Checks for calls to `core::mem::swap` where either parameter is derived from a pointer
++ ///
++ /// ### Why is this bad?
++ /// When at least one parameter to `swap` is derived from a pointer it may overlap with the
++ /// other. This would then lead to undefined behavior.
++ ///
++ /// ### Example
++ /// ```rust
++ /// unsafe fn swap(x: &[*mut u32], y: &[*mut u32]) {
++ /// for (&x, &y) in x.iter().zip(y) {
++ /// core::mem::swap(&mut *x, &mut *y);
++ /// }
++ /// }
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// unsafe fn swap(x: &[*mut u32], y: &[*mut u32]) {
++ /// for (&x, &y) in x.iter().zip(y) {
++ /// core::ptr::swap(x, y);
++ /// }
++ /// }
++ /// ```
++ #[clippy::version = "1.63.0"]
++ pub SWAP_PTR_TO_REF,
++ suspicious,
++ "call to `mem::swap` using pointer derived references"
++}
++declare_lint_pass!(SwapPtrToRef => [SWAP_PTR_TO_REF]);
++
++impl LateLintPass<'_> for SwapPtrToRef {
++ fn check_expr(&mut self, cx: &LateContext<'_>, e: &Expr<'_>) {
++ if let ExprKind::Call(fn_expr, [arg1, arg2]) = e.kind
++ && let Some(fn_id) = path_def_id(cx, fn_expr)
++ && match_def_path(cx, fn_id, &paths::MEM_SWAP)
++ && let ctxt = e.span.ctxt()
++ && let (from_ptr1, arg1_span) = is_ptr_to_ref(cx, arg1, ctxt)
++ && let (from_ptr2, arg2_span) = is_ptr_to_ref(cx, arg2, ctxt)
++ && (from_ptr1 || from_ptr2)
++ {
++ span_lint_and_then(
++ cx,
++ SWAP_PTR_TO_REF,
++ e.span,
++ "call to `core::mem::swap` with a parameter derived from a raw pointer",
++ |diag| {
++ if !((from_ptr1 && arg1_span.is_none()) || (from_ptr2 && arg2_span.is_none())) {
++ let mut app = Applicability::MachineApplicable;
++ let snip1 = snippet_with_context(cx, arg1_span.unwrap_or(arg1.span), ctxt, "..", &mut app).0;
++ let snip2 = snippet_with_context(cx, arg2_span.unwrap_or(arg2.span), ctxt, "..", &mut app).0;
++ diag.span_suggestion(e.span, "use ptr::swap", format!("core::ptr::swap({}, {})", snip1, snip2), app);
++ }
++ }
++ );
++ }
++ }
++}
++
++/// Checks if the expression converts a mutable pointer to a mutable reference. If it is, also
++/// returns the span of the pointer expression if it's suitable for making a suggestion.
++fn is_ptr_to_ref(cx: &LateContext<'_>, e: &Expr<'_>, ctxt: SyntaxContext) -> (bool, Option<Span>) {
++ if let ExprKind::AddrOf(BorrowKind::Ref, Mutability::Mut, borrowed_expr) = e.kind
++ && let ExprKind::Unary(UnOp::Deref, derefed_expr) = borrowed_expr.kind
++ && cx.typeck_results().expr_ty(derefed_expr).is_unsafe_ptr()
++ {
++ (true, (borrowed_expr.span.ctxt() == ctxt || derefed_expr.span.ctxt() == ctxt).then(|| derefed_expr.span))
++ } else {
++ (false, None)
++ }
++}
--- /dev/null
- /// Could be written as:
- ///
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::source::{snippet, snippet_with_applicability};
+use clippy_utils::{SpanlessEq, SpanlessHash};
+use core::hash::{Hash, Hasher};
+use if_chain::if_chain;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::unhash::UnhashMap;
+use rustc_errors::Applicability;
+use rustc_hir::def::Res;
+use rustc_hir::{
+ GenericBound, Generics, Item, ItemKind, Node, Path, PathSegment, PredicateOrigin, QPath, TraitItem, Ty, TyKind,
+ WherePredicate,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::Span;
+use std::fmt::Write as _;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint warns about unnecessary type repetitions in trait bounds
+ ///
+ /// ### Why is this bad?
+ /// Repeating the type for every bound makes the code
+ /// less readable than combining the bounds
+ ///
+ /// ### Example
+ /// ```rust
+ /// pub fn foo<T>(t: T) where T: Copy, T: Clone {}
+ /// ```
+ ///
+ /// Could be written as:
+ ///
+ /// ```rust
+ /// pub fn foo<T>(t: T) where T: Copy + Clone {}
+ /// ```
+ #[clippy::version = "1.38.0"]
+ pub TYPE_REPETITION_IN_BOUNDS,
+ pedantic,
+ "Types are repeated unnecessary in trait bounds use `+` instead of using `T: _, T: _`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for cases where generics are being used and multiple
+ /// syntax specifications for trait bounds are used simultaneously.
+ ///
+ /// ### Why is this bad?
+ /// Duplicate bounds makes the code
+ /// less readable than specifying them only once.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn func<T: Clone + Default>(arg: T) where T: Clone + Default {}
+ /// ```
+ ///
- /// ```
- /// or
++ /// Use instead:
+ /// ```rust
++ /// # mod hidden {
+ /// fn func<T: Clone + Default>(arg: T) {}
- /// ```rust
++ /// # }
++ ///
++ /// // or
+ ///
+ /// fn func<T>(arg: T) where T: Clone + Default {}
+ /// ```
+ #[clippy::version = "1.47.0"]
+ pub TRAIT_DUPLICATION_IN_BOUNDS,
+ pedantic,
+ "Check if the same trait bounds are specified twice during a function declaration"
+}
+
+#[derive(Copy, Clone)]
+pub struct TraitBounds {
+ max_trait_bounds: u64,
+}
+
+impl TraitBounds {
+ #[must_use]
+ pub fn new(max_trait_bounds: u64) -> Self {
+ Self { max_trait_bounds }
+ }
+}
+
+impl_lint_pass!(TraitBounds => [TYPE_REPETITION_IN_BOUNDS, TRAIT_DUPLICATION_IN_BOUNDS]);
+
+impl<'tcx> LateLintPass<'tcx> for TraitBounds {
+ fn check_generics(&mut self, cx: &LateContext<'tcx>, gen: &'tcx Generics<'_>) {
+ self.check_type_repetition(cx, gen);
+ check_trait_bound_duplication(cx, gen);
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'tcx>) {
+ let mut self_bounds_map = FxHashMap::default();
+
+ for predicate in item.generics.predicates {
+ if_chain! {
+ if let WherePredicate::BoundPredicate(ref bound_predicate) = predicate;
+ if bound_predicate.origin != PredicateOrigin::ImplTrait;
+ if !bound_predicate.span.from_expansion();
+ if let TyKind::Path(QPath::Resolved(_, Path { segments, .. })) = bound_predicate.bounded_ty.kind;
+ if let Some(PathSegment {
+ res: Some(Res::SelfTy{ trait_: Some(def_id), alias_to: _ }), ..
+ }) = segments.first();
+ if let Some(
+ Node::Item(
+ Item {
+ kind: ItemKind::Trait(_, _, _, self_bounds, _),
+ .. }
+ )
+ ) = cx.tcx.hir().get_if_local(*def_id);
+ then {
+ if self_bounds_map.is_empty() {
+ for bound in self_bounds.iter() {
+ let Some((self_res, self_segments, _)) = get_trait_info_from_bound(bound) else { continue };
+ self_bounds_map.insert(self_res, self_segments);
+ }
+ }
+
+ bound_predicate
+ .bounds
+ .iter()
+ .filter_map(get_trait_info_from_bound)
+ .for_each(|(trait_item_res, trait_item_segments, span)| {
+ if let Some(self_segments) = self_bounds_map.get(&trait_item_res) {
+ if SpanlessEq::new(cx).eq_path_segments(self_segments, trait_item_segments) {
+ span_lint_and_help(
+ cx,
+ TRAIT_DUPLICATION_IN_BOUNDS,
+ span,
+ "this trait bound is already specified in trait declaration",
+ None,
+ "consider removing this trait bound",
+ );
+ }
+ }
+ });
+ }
+ }
+ }
+ }
+}
+
+impl TraitBounds {
+ fn check_type_repetition<'tcx>(self, cx: &LateContext<'tcx>, gen: &'tcx Generics<'_>) {
+ struct SpanlessTy<'cx, 'tcx> {
+ ty: &'tcx Ty<'tcx>,
+ cx: &'cx LateContext<'tcx>,
+ }
+ impl PartialEq for SpanlessTy<'_, '_> {
+ fn eq(&self, other: &Self) -> bool {
+ let mut eq = SpanlessEq::new(self.cx);
+ eq.inter_expr().eq_ty(self.ty, other.ty)
+ }
+ }
+ impl Hash for SpanlessTy<'_, '_> {
+ fn hash<H: Hasher>(&self, h: &mut H) {
+ let mut t = SpanlessHash::new(self.cx);
+ t.hash_ty(self.ty);
+ h.write_u64(t.finish());
+ }
+ }
+ impl Eq for SpanlessTy<'_, '_> {}
+
+ if gen.span.from_expansion() {
+ return;
+ }
+ let mut map: UnhashMap<SpanlessTy<'_, '_>, Vec<&GenericBound<'_>>> = UnhashMap::default();
+ let mut applicability = Applicability::MaybeIncorrect;
+ for bound in gen.predicates {
+ if_chain! {
+ if let WherePredicate::BoundPredicate(ref p) = bound;
+ if p.origin != PredicateOrigin::ImplTrait;
+ if p.bounds.len() as u64 <= self.max_trait_bounds;
+ if !p.span.from_expansion();
+ if let Some(ref v) = map.insert(
+ SpanlessTy { ty: p.bounded_ty, cx },
+ p.bounds.iter().collect::<Vec<_>>()
+ );
+
+ then {
+ let mut hint_string = format!(
+ "consider combining the bounds: `{}:",
+ snippet(cx, p.bounded_ty.span, "_")
+ );
+ for b in v.iter() {
+ if let GenericBound::Trait(ref poly_trait_ref, _) = b {
+ let path = &poly_trait_ref.trait_ref.path;
+ let _ = write!(hint_string,
+ " {} +",
+ snippet_with_applicability(cx, path.span, "..", &mut applicability)
+ );
+ }
+ }
+ for b in p.bounds.iter() {
+ if let GenericBound::Trait(ref poly_trait_ref, _) = b {
+ let path = &poly_trait_ref.trait_ref.path;
+ let _ = write!(hint_string,
+ " {} +",
+ snippet_with_applicability(cx, path.span, "..", &mut applicability)
+ );
+ }
+ }
+ hint_string.truncate(hint_string.len() - 2);
+ hint_string.push('`');
+ span_lint_and_help(
+ cx,
+ TYPE_REPETITION_IN_BOUNDS,
+ p.span,
+ "this type has already been used as a bound predicate",
+ None,
+ &hint_string,
+ );
+ }
+ }
+ }
+ }
+}
+
+fn check_trait_bound_duplication(cx: &LateContext<'_>, gen: &'_ Generics<'_>) {
+ if gen.span.from_expansion() || gen.params.is_empty() || gen.predicates.is_empty() {
+ return;
+ }
+
+ let mut map = FxHashMap::<_, Vec<_>>::default();
+ for predicate in gen.predicates {
+ if_chain! {
+ if let WherePredicate::BoundPredicate(ref bound_predicate) = predicate;
+ if bound_predicate.origin != PredicateOrigin::ImplTrait;
+ if !bound_predicate.span.from_expansion();
+ if let TyKind::Path(QPath::Resolved(_, Path { segments, .. })) = bound_predicate.bounded_ty.kind;
+ if let Some(segment) = segments.first();
+ then {
+ for (res_where, _, span_where) in bound_predicate.bounds.iter().filter_map(get_trait_info_from_bound) {
+ let trait_resolutions_direct = map.entry(segment.ident).or_default();
+ if let Some((_, span_direct)) = trait_resolutions_direct
+ .iter()
+ .find(|(res_direct, _)| *res_direct == res_where) {
+ span_lint_and_help(
+ cx,
+ TRAIT_DUPLICATION_IN_BOUNDS,
+ *span_direct,
+ "this trait bound is already specified in the where clause",
+ None,
+ "consider removing this trait bound",
+ );
+ }
+ else {
+ trait_resolutions_direct.push((res_where, span_where));
+ }
+ }
+ }
+ }
+ }
+}
+
+fn get_trait_info_from_bound<'a>(bound: &'a GenericBound<'_>) -> Option<(Res, &'a [PathSegment<'a>], Span)> {
+ if let GenericBound::Trait(t, _) = bound {
+ Some((t.trait_ref.path.res, t.trait_ref.path.segments, t.span))
+ } else {
+ None
+ }
+}
--- /dev/null
- nursery,
+mod crosspointer_transmute;
+mod transmute_float_to_int;
+mod transmute_int_to_bool;
+mod transmute_int_to_char;
+mod transmute_int_to_float;
+mod transmute_num_to_bytes;
+mod transmute_ptr_to_ptr;
+mod transmute_ptr_to_ref;
+mod transmute_ref_to_ref;
+mod transmute_undefined_repr;
+mod transmutes_expressible_as_ptr_casts;
+mod unsound_collection_transmute;
+mod useless_transmute;
+mod utils;
+mod wrong_transmute;
+
+use clippy_utils::in_constant;
+use if_chain::if_chain;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes that can't ever be correct on any
+ /// architecture.
+ ///
+ /// ### Why is this bad?
+ /// It's basically guaranteed to be undefined behavior.
+ ///
+ /// ### Known problems
+ /// When accessing C, users might want to store pointer
+ /// sized objects in `extradata` arguments to save an allocation.
+ ///
+ /// ### Example
+ /// ```ignore
+ /// let ptr: *const T = core::intrinsics::transmute('x')
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub WRONG_TRANSMUTE,
+ correctness,
+ "transmutes that are confusing at best, undefined behavior at worst and always useless"
+}
+
+// FIXME: Move this to `complexity` again, after #5343 is fixed
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes to the original type of the object
+ /// and transmutes that could be a cast.
+ ///
+ /// ### Why is this bad?
+ /// Readability. The code tricks people into thinking that
+ /// something complex is going on.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// core::intrinsics::transmute(t); // where the result type is the same as `t`'s
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub USELESS_TRANSMUTE,
++ complexity,
+ "transmutes that have the same to and from types or could be a cast/coercion"
+}
+
+// FIXME: Merge this lint with USELESS_TRANSMUTE once that is out of the nursery.
+declare_clippy_lint! {
+ /// ### What it does
+ ///Checks for transmutes that could be a pointer cast.
+ ///
+ /// ### Why is this bad?
+ /// Readability. The code tricks people into thinking that
+ /// something complex is going on.
+ ///
+ /// ### Example
+ ///
+ /// ```rust
+ /// # let p: *const [i32] = &[];
+ /// unsafe { std::mem::transmute::<*const [i32], *const [u16]>(p) };
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// # let p: *const [i32] = &[];
+ /// p as *const [u16];
+ /// ```
+ #[clippy::version = "1.47.0"]
+ pub TRANSMUTES_EXPRESSIBLE_AS_PTR_CASTS,
+ complexity,
+ "transmutes that could be a pointer cast"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes between a type `T` and `*T`.
+ ///
+ /// ### Why is this bad?
+ /// It's easy to mistakenly transmute between a type and a
+ /// pointer to that type.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// core::intrinsics::transmute(t) // where the result type is the same as
+ /// // `*t` or `&t`'s
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CROSSPOINTER_TRANSMUTE,
+ complexity,
+ "transmutes that have to or from types that are a pointer to the other"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes from a pointer to a reference.
+ ///
+ /// ### Why is this bad?
+ /// This can always be rewritten with `&` and `*`.
+ ///
+ /// ### Known problems
+ /// - `mem::transmute` in statics and constants is stable from Rust 1.46.0,
+ /// while dereferencing raw pointer is not stable yet.
+ /// If you need to do this in those places,
+ /// you would have to use `transmute` instead.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// unsafe {
+ /// let _: &T = std::mem::transmute(p); // where p: *const T
+ /// }
+ ///
+ /// // can be written:
+ /// let _: &T = &*p;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub TRANSMUTE_PTR_TO_REF,
+ complexity,
+ "transmutes from a pointer to a reference type"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes from an integer to a `char`.
+ ///
+ /// ### Why is this bad?
+ /// Not every integer is a Unicode scalar value.
+ ///
+ /// ### Known problems
+ /// - [`from_u32`] which this lint suggests using is slower than `transmute`
+ /// as it needs to validate the input.
+ /// If you are certain that the input is always a valid Unicode scalar value,
+ /// use [`from_u32_unchecked`] which is as fast as `transmute`
+ /// but has a semantically meaningful name.
+ /// - You might want to handle `None` returned from [`from_u32`] instead of calling `unwrap`.
+ ///
+ /// [`from_u32`]: https://doc.rust-lang.org/std/char/fn.from_u32.html
+ /// [`from_u32_unchecked`]: https://doc.rust-lang.org/std/char/fn.from_u32_unchecked.html
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = 1_u32;
+ /// unsafe {
+ /// let _: char = std::mem::transmute(x); // where x: u32
+ /// }
+ ///
+ /// // should be:
+ /// let _ = std::char::from_u32(x).unwrap();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub TRANSMUTE_INT_TO_CHAR,
+ complexity,
+ "transmutes from an integer to a `char`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes from a `&[u8]` to a `&str`.
+ ///
+ /// ### Why is this bad?
+ /// Not every byte slice is a valid UTF-8 string.
+ ///
+ /// ### Known problems
+ /// - [`from_utf8`] which this lint suggests using is slower than `transmute`
+ /// as it needs to validate the input.
+ /// If you are certain that the input is always a valid UTF-8,
+ /// use [`from_utf8_unchecked`] which is as fast as `transmute`
+ /// but has a semantically meaningful name.
+ /// - You might want to handle errors returned from [`from_utf8`] instead of calling `unwrap`.
+ ///
+ /// [`from_utf8`]: https://doc.rust-lang.org/std/str/fn.from_utf8.html
+ /// [`from_utf8_unchecked`]: https://doc.rust-lang.org/std/str/fn.from_utf8_unchecked.html
+ ///
+ /// ### Example
+ /// ```rust
+ /// let b: &[u8] = &[1_u8, 2_u8];
+ /// unsafe {
+ /// let _: &str = std::mem::transmute(b); // where b: &[u8]
+ /// }
+ ///
+ /// // should be:
+ /// let _ = std::str::from_utf8(b).unwrap();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub TRANSMUTE_BYTES_TO_STR,
+ complexity,
+ "transmutes from a `&[u8]` to a `&str`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes from an integer to a `bool`.
+ ///
+ /// ### Why is this bad?
+ /// This might result in an invalid in-memory representation of a `bool`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = 1_u8;
+ /// unsafe {
+ /// let _: bool = std::mem::transmute(x); // where x: u8
+ /// }
+ ///
+ /// // should be:
+ /// let _: bool = x != 0;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub TRANSMUTE_INT_TO_BOOL,
+ complexity,
+ "transmutes from an integer to a `bool`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes from an integer to a float.
+ ///
+ /// ### Why is this bad?
+ /// Transmutes are dangerous and error-prone, whereas `from_bits` is intuitive
+ /// and safe.
+ ///
+ /// ### Example
+ /// ```rust
+ /// unsafe {
+ /// let _: f32 = std::mem::transmute(1_u32); // where x: u32
+ /// }
+ ///
+ /// // should be:
+ /// let _: f32 = f32::from_bits(1_u32);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub TRANSMUTE_INT_TO_FLOAT,
+ complexity,
+ "transmutes from an integer to a float"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes from a float to an integer.
+ ///
+ /// ### Why is this bad?
+ /// Transmutes are dangerous and error-prone, whereas `to_bits` is intuitive
+ /// and safe.
+ ///
+ /// ### Example
+ /// ```rust
+ /// unsafe {
+ /// let _: u32 = std::mem::transmute(1f32);
+ /// }
+ ///
+ /// // should be:
+ /// let _: u32 = 1f32.to_bits();
+ /// ```
+ #[clippy::version = "1.41.0"]
+ pub TRANSMUTE_FLOAT_TO_INT,
+ complexity,
+ "transmutes from a float to an integer"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes from a number to an array of `u8`
+ ///
+ /// ### Why this is bad?
+ /// Transmutes are dangerous and error-prone, whereas `to_ne_bytes`
+ /// is intuitive and safe.
+ ///
+ /// ### Example
+ /// ```rust
+ /// unsafe {
+ /// let x: [u8; 8] = std::mem::transmute(1i64);
+ /// }
+ ///
+ /// // should be
+ /// let x: [u8; 8] = 0i64.to_ne_bytes();
+ /// ```
+ #[clippy::version = "1.58.0"]
+ pub TRANSMUTE_NUM_TO_BYTES,
+ complexity,
+ "transmutes from a number to an array of `u8`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes from a pointer to a pointer, or
+ /// from a reference to a reference.
+ ///
+ /// ### Why is this bad?
+ /// Transmutes are dangerous, and these can instead be
+ /// written as casts.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let ptr = &1u32 as *const u32;
+ /// unsafe {
+ /// // pointer-to-pointer transmute
+ /// let _: *const f32 = std::mem::transmute(ptr);
+ /// // ref-ref transmute
+ /// let _: &f32 = std::mem::transmute(&1u32);
+ /// }
+ /// // These can be respectively written:
+ /// let _ = ptr as *const f32;
+ /// let _ = unsafe{ &*(&1u32 as *const u32 as *const f32) };
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub TRANSMUTE_PTR_TO_PTR,
+ pedantic,
+ "transmutes from a pointer to a pointer / a reference to a reference"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes between collections whose
+ /// types have different ABI, size or alignment.
+ ///
+ /// ### Why is this bad?
+ /// This is undefined behavior.
+ ///
+ /// ### Known problems
+ /// Currently, we cannot know whether a type is a
+ /// collection, so we just lint the ones that come with `std`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // different size, therefore likely out-of-bounds memory access
+ /// // You absolutely do not want this in your code!
+ /// unsafe {
+ /// std::mem::transmute::<_, Vec<u32>>(vec![2_u16])
+ /// };
+ /// ```
+ ///
+ /// You must always iterate, map and collect the values:
+ ///
+ /// ```rust
+ /// vec![2_u16].into_iter().map(u32::from).collect::<Vec<_>>();
+ /// ```
+ #[clippy::version = "1.40.0"]
+ pub UNSOUND_COLLECTION_TRANSMUTE,
+ correctness,
+ "transmute between collections of layout-incompatible types"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for transmutes between types which do not have a representation defined relative to
+ /// each other.
+ ///
+ /// ### Why is this bad?
+ /// The results of such a transmute are not defined.
+ ///
+ /// ### Known problems
+ /// This lint has had multiple problems in the past and was moved to `nursery`. See issue
+ /// [#8496](https://github.com/rust-lang/rust-clippy/issues/8496) for more details.
+ ///
+ /// ### Example
+ /// ```rust
+ /// struct Foo<T>(u32, T);
+ /// let _ = unsafe { core::mem::transmute::<Foo<u32>, Foo<i32>>(Foo(0u32, 0u32)) };
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// #[repr(C)]
+ /// struct Foo<T>(u32, T);
+ /// let _ = unsafe { core::mem::transmute::<Foo<u32>, Foo<i32>>(Foo(0u32, 0u32)) };
+ /// ```
+ #[clippy::version = "1.60.0"]
+ pub TRANSMUTE_UNDEFINED_REPR,
+ nursery,
+ "transmute to or from a type with an undefined representation"
+}
+
+declare_lint_pass!(Transmute => [
+ CROSSPOINTER_TRANSMUTE,
+ TRANSMUTE_PTR_TO_REF,
+ TRANSMUTE_PTR_TO_PTR,
+ USELESS_TRANSMUTE,
+ WRONG_TRANSMUTE,
+ TRANSMUTE_INT_TO_CHAR,
+ TRANSMUTE_BYTES_TO_STR,
+ TRANSMUTE_INT_TO_BOOL,
+ TRANSMUTE_INT_TO_FLOAT,
+ TRANSMUTE_FLOAT_TO_INT,
+ TRANSMUTE_NUM_TO_BYTES,
+ UNSOUND_COLLECTION_TRANSMUTE,
+ TRANSMUTES_EXPRESSIBLE_AS_PTR_CASTS,
+ TRANSMUTE_UNDEFINED_REPR,
+]);
+
+impl<'tcx> LateLintPass<'tcx> for Transmute {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Call(path_expr, [arg]) = e.kind;
+ if let ExprKind::Path(ref qpath) = path_expr.kind;
+ if let Some(def_id) = cx.qpath_res(qpath, path_expr.hir_id).opt_def_id();
+ if cx.tcx.is_diagnostic_item(sym::transmute, def_id);
+ then {
+ // Avoid suggesting non-const operations in const contexts:
+ // - from/to bits (https://github.com/rust-lang/rust/issues/73736)
+ // - dereferencing raw pointers (https://github.com/rust-lang/rust/issues/51911)
+ // - char conversions (https://github.com/rust-lang/rust/issues/89259)
+ let const_context = in_constant(cx, e.hir_id);
+
+ let from_ty = cx.typeck_results().expr_ty_adjusted(arg);
+ // Adjustments for `to_ty` happen after the call to `transmute`, so don't use them.
+ let to_ty = cx.typeck_results().expr_ty(e);
+
+ // If useless_transmute is triggered, the other lints can be skipped.
+ if useless_transmute::check(cx, e, from_ty, to_ty, arg) {
+ return;
+ }
+
+ let linted = wrong_transmute::check(cx, e, from_ty, to_ty)
+ | crosspointer_transmute::check(cx, e, from_ty, to_ty)
+ | transmute_ptr_to_ref::check(cx, e, from_ty, to_ty, arg, qpath)
+ | transmute_int_to_char::check(cx, e, from_ty, to_ty, arg, const_context)
+ | transmute_ref_to_ref::check(cx, e, from_ty, to_ty, arg, const_context)
+ | transmute_ptr_to_ptr::check(cx, e, from_ty, to_ty, arg)
+ | transmute_int_to_bool::check(cx, e, from_ty, to_ty, arg)
+ | transmute_int_to_float::check(cx, e, from_ty, to_ty, arg, const_context)
+ | transmute_float_to_int::check(cx, e, from_ty, to_ty, arg, const_context)
+ | transmute_num_to_bytes::check(cx, e, from_ty, to_ty, arg, const_context)
+ | (
+ unsound_collection_transmute::check(cx, e, from_ty, to_ty)
+ || transmute_undefined_repr::check(cx, e, from_ty, to_ty)
+ );
+
+ if !linted {
+ transmutes_expressible_as_ptr_casts::check(cx, e, from_ty, to_ty, arg);
+ }
+ }
+ }
+ }
+}
--- /dev/null
- use rustc_middle::ty::{self, Ty};
+use super::USELESS_TRANSMUTE;
+use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
+use clippy_utils::sugg;
+use rustc_errors::Applicability;
+use rustc_hir::Expr;
+use rustc_lint::LateContext;
- _ if from_ty == to_ty => {
++use rustc_middle::ty::{self, Ty, TypeFoldable};
+
+/// Checks for `useless_transmute` lint.
+/// Returns `true` if it's triggered, otherwise returns `false`.
+pub(super) fn check<'tcx>(
+ cx: &LateContext<'tcx>,
+ e: &'tcx Expr<'_>,
+ from_ty: Ty<'tcx>,
+ to_ty: Ty<'tcx>,
+ arg: &'tcx Expr<'_>,
+) -> bool {
+ match (&from_ty.kind(), &to_ty.kind()) {
- span_lint_and_then(
- cx,
- USELESS_TRANSMUTE,
- e.span,
- "transmute from a reference to a pointer",
- |diag| {
- if let Some(arg) = sugg::Sugg::hir_opt(cx, arg) {
- let rty_and_mut = ty::TypeAndMut {
- ty: *rty,
- mutbl: *rty_mutbl,
- };
++ _ if from_ty == to_ty && !from_ty.has_erased_regions() => {
+ span_lint(
+ cx,
+ USELESS_TRANSMUTE,
+ e.span,
+ &format!("transmute from a type (`{}`) to itself", from_ty),
+ );
+ true
+ },
+ (ty::Ref(_, rty, rty_mutbl), ty::RawPtr(ptr_ty)) => {
- let sugg = if *ptr_ty == rty_and_mut {
- arg.as_ty(to_ty)
- } else {
- arg.as_ty(cx.tcx.mk_ptr(rty_and_mut)).as_ty(to_ty)
- };
++ // No way to give the correct suggestion here. Avoid linting for now.
++ if !rty.has_erased_regions() {
++ span_lint_and_then(
++ cx,
++ USELESS_TRANSMUTE,
++ e.span,
++ "transmute from a reference to a pointer",
++ |diag| {
++ if let Some(arg) = sugg::Sugg::hir_opt(cx, arg) {
++ let rty_and_mut = ty::TypeAndMut {
++ ty: *rty,
++ mutbl: *rty_mutbl,
++ };
+
- diag.span_suggestion(e.span, "try", sugg.to_string(), Applicability::Unspecified);
- }
- },
- );
++ let sugg = if *ptr_ty == rty_and_mut {
++ arg.as_ty(to_ty)
++ } else {
++ arg.as_ty(cx.tcx.mk_ptr(rty_and_mut)).as_ty(to_ty)
++ };
+
++ diag.span_suggestion(e.span, "try", sugg.to_string(), Applicability::Unspecified);
++ }
++ },
++ );
++ }
+ true
+ },
+ (ty::Int(_) | ty::Uint(_), ty::RawPtr(_)) => {
+ span_lint_and_then(
+ cx,
+ USELESS_TRANSMUTE,
+ e.span,
+ "transmute from an integer to a pointer",
+ |diag| {
+ if let Some(arg) = sugg::Sugg::hir_opt(cx, arg) {
+ diag.span_suggestion(
+ e.span,
+ "try",
+ arg.as_ty(&to_ty.to_string()).to_string(),
+ Applicability::Unspecified,
+ );
+ }
+ },
+ );
+ true
+ },
+ _ => false,
+ }
+}
--- /dev/null
--- /dev/null
++use clippy_utils::diagnostics::span_lint_and_sugg;
++use rustc_ast::ast::{Expr, ExprKind, LitFloatType, LitKind};
++use rustc_errors::Applicability;
++use rustc_lint::{EarlyContext, EarlyLintPass};
++use rustc_session::{declare_lint_pass, declare_tool_lint};
++
++declare_clippy_lint! {
++ /// ### What it does
++ ///
++ /// Detects cases where a whole-number literal float is being rounded, using
++ /// the `floor`, `ceil`, or `round` methods.
++ ///
++ /// ### Why is this bad?
++ ///
++ /// This is unnecessary and confusing to the reader. Doing this is probably a mistake.
++ ///
++ /// ### Example
++ /// ```rust
++ /// let x = 1f32.ceil();
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// let x = 1f32;
++ /// ```
++ #[clippy::version = "1.62.0"]
++ pub UNUSED_ROUNDING,
++ nursery,
++ "Uselessly rounding a whole number floating-point literal"
++}
++declare_lint_pass!(UnusedRounding => [UNUSED_ROUNDING]);
++
++fn is_useless_rounding(expr: &Expr) -> Option<(&str, String)> {
++ if let ExprKind::MethodCall(name_ident, args, _) = &expr.kind
++ && let method_name = name_ident.ident.name.as_str()
++ && (method_name == "ceil" || method_name == "round" || method_name == "floor")
++ && !args.is_empty()
++ && let ExprKind::Lit(spanned) = &args[0].kind
++ && let LitKind::Float(symbol, ty) = spanned.kind {
++ let f = symbol.as_str().parse::<f64>().unwrap();
++ let f_str = symbol.to_string() + if let LitFloatType::Suffixed(ty) = ty {
++ ty.name_str()
++ } else {
++ ""
++ };
++ if f.fract() == 0.0 {
++ Some((method_name, f_str))
++ } else {
++ None
++ }
++ } else {
++ None
++ }
++}
++
++impl EarlyLintPass for UnusedRounding {
++ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
++ if let Some((method_name, float)) = is_useless_rounding(expr) {
++ span_lint_and_sugg(
++ cx,
++ UNUSED_ROUNDING,
++ expr.span,
++ &format!("used the `{}` method with a whole number float", method_name),
++ &format!("remove the `{}` method call", method_name),
++ float,
++ Applicability::MachineApplicable,
++ );
++ }
++ }
++}
--- /dev/null
- if let PatKind::Path(QPath::Resolved(_, path)) = pat.kind;
- if !matches!(path.res, Res::SelfTy { .. } | Res::Def(DefKind::TyParam, _));
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::ty::same_type_and_consts;
+use clippy_utils::{meets_msrv, msrvs};
+use if_chain::if_chain;
+use rustc_data_structures::fx::FxHashSet;
+use rustc_errors::Applicability;
+use rustc_hir::{
+ self as hir,
+ def::{CtorOf, DefKind, Res},
+ def_id::LocalDefId,
+ intravisit::{walk_inf, walk_ty, Visitor},
+ Expr, ExprKind, FnRetTy, FnSig, GenericArg, HirId, Impl, ImplItemKind, Item, ItemKind, Pat, PatKind, Path, QPath,
+ TyKind,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::Span;
+use rustc_typeck::hir_ty_to_ty;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for unnecessary repetition of structure name when a
+ /// replacement with `Self` is applicable.
+ ///
+ /// ### Why is this bad?
+ /// Unnecessary repetition. Mixed use of `Self` and struct
+ /// name
+ /// feels inconsistent.
+ ///
+ /// ### Known problems
+ /// - Unaddressed false negative in fn bodies of trait implementations
+ /// - False positive with associated types in traits (#4140)
+ ///
+ /// ### Example
+ /// ```rust
+ /// struct Foo;
+ /// impl Foo {
+ /// fn new() -> Foo {
+ /// Foo {}
+ /// }
+ /// }
+ /// ```
+ /// could be
+ /// ```rust
+ /// struct Foo;
+ /// impl Foo {
+ /// fn new() -> Self {
+ /// Self {}
+ /// }
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub USE_SELF,
+ nursery,
+ "unnecessary structure name repetition whereas `Self` is applicable"
+}
+
+#[derive(Default)]
+pub struct UseSelf {
+ msrv: Option<RustcVersion>,
+ stack: Vec<StackItem>,
+}
+
+impl UseSelf {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self {
+ msrv,
+ ..Self::default()
+ }
+ }
+}
+
+#[derive(Debug)]
+enum StackItem {
+ Check {
+ impl_id: LocalDefId,
+ in_body: u32,
+ types_to_skip: FxHashSet<HirId>,
+ },
+ NoCheck,
+}
+
+impl_lint_pass!(UseSelf => [USE_SELF]);
+
+const SEGMENTS_MSG: &str = "segments should be composed of at least 1 element";
+
+impl<'tcx> LateLintPass<'tcx> for UseSelf {
+ fn check_item(&mut self, _cx: &LateContext<'_>, item: &Item<'_>) {
+ if matches!(item.kind, ItemKind::OpaqueTy(_)) {
+ // skip over `ItemKind::OpaqueTy` in order to lint `foo() -> impl <..>`
+ return;
+ }
+ // We push the self types of `impl`s on a stack here. Only the top type on the stack is
+ // relevant for linting, since this is the self type of the `impl` we're currently in. To
+ // avoid linting on nested items, we push `StackItem::NoCheck` on the stack to signal, that
+ // we're in an `impl` or nested item, that we don't want to lint
+ let stack_item = if_chain! {
+ if let ItemKind::Impl(Impl { self_ty, .. }) = item.kind;
+ if let TyKind::Path(QPath::Resolved(_, item_path)) = self_ty.kind;
+ let parameters = &item_path.segments.last().expect(SEGMENTS_MSG).args;
+ if parameters.as_ref().map_or(true, |params| {
+ !params.parenthesized && !params.args.iter().any(|arg| matches!(arg, GenericArg::Lifetime(_)))
+ });
+ then {
+ StackItem::Check {
+ impl_id: item.def_id,
+ in_body: 0,
+ types_to_skip: std::iter::once(self_ty.hir_id).collect(),
+ }
+ } else {
+ StackItem::NoCheck
+ }
+ };
+ self.stack.push(stack_item);
+ }
+
+ fn check_item_post(&mut self, _: &LateContext<'_>, item: &Item<'_>) {
+ if !matches!(item.kind, ItemKind::OpaqueTy(_)) {
+ self.stack.pop();
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext<'_>, impl_item: &hir::ImplItem<'_>) {
+ // We want to skip types in trait `impl`s that aren't declared as `Self` in the trait
+ // declaration. The collection of those types is all this method implementation does.
+ if_chain! {
+ if let ImplItemKind::Fn(FnSig { decl, .. }, ..) = impl_item.kind;
+ if let Some(&mut StackItem::Check {
+ impl_id,
+ ref mut types_to_skip,
+ ..
+ }) = self.stack.last_mut();
+ if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(impl_id);
+ then {
+ // `self_ty` is the semantic self type of `impl <trait> for <type>`. This cannot be
+ // `Self`.
+ let self_ty = impl_trait_ref.self_ty();
+
+ // `trait_method_sig` is the signature of the function, how it is declared in the
+ // trait, not in the impl of the trait.
+ let trait_method = cx
+ .tcx
+ .associated_item(impl_item.def_id)
+ .trait_item_def_id
+ .expect("impl method matches a trait method");
+ let trait_method_sig = cx.tcx.fn_sig(trait_method);
+ let trait_method_sig = cx.tcx.erase_late_bound_regions(trait_method_sig);
+
+ // `impl_inputs_outputs` is an iterator over the types (`hir::Ty`) declared in the
+ // implementation of the trait.
+ let output_hir_ty = if let FnRetTy::Return(ty) = &decl.output {
+ Some(&**ty)
+ } else {
+ None
+ };
+ let impl_inputs_outputs = decl.inputs.iter().chain(output_hir_ty);
+
+ // `impl_hir_ty` (of type `hir::Ty`) represents the type written in the signature.
+ //
+ // `trait_sem_ty` (of type `ty::Ty`) is the semantic type for the signature in the
+ // trait declaration. This is used to check if `Self` was used in the trait
+ // declaration.
+ //
+ // If `any`where in the `trait_sem_ty` the `self_ty` was used verbatim (as opposed
+ // to `Self`), we want to skip linting that type and all subtypes of it. This
+ // avoids suggestions to e.g. replace `Vec<u8>` with `Vec<Self>`, in an `impl Trait
+ // for u8`, when the trait always uses `Vec<u8>`.
+ //
+ // See also https://github.com/rust-lang/rust-clippy/issues/2894.
+ for (impl_hir_ty, trait_sem_ty) in impl_inputs_outputs.zip(trait_method_sig.inputs_and_output) {
+ if trait_sem_ty.walk().any(|inner| inner == self_ty.into()) {
+ let mut visitor = SkipTyCollector::default();
+ visitor.visit_ty(impl_hir_ty);
+ types_to_skip.extend(visitor.types_to_skip);
+ }
+ }
+ }
+ }
+ }
+
+ fn check_body(&mut self, _: &LateContext<'_>, _: &hir::Body<'_>) {
+ // `hir_ty_to_ty` cannot be called in `Body`s or it will panic (sometimes). But in bodies
+ // we can use `cx.typeck_results.node_type(..)` to get the `ty::Ty` from a `hir::Ty`.
+ // However the `node_type()` method can *only* be called in bodies.
+ if let Some(&mut StackItem::Check { ref mut in_body, .. }) = self.stack.last_mut() {
+ *in_body = in_body.saturating_add(1);
+ }
+ }
+
+ fn check_body_post(&mut self, _: &LateContext<'_>, _: &hir::Body<'_>) {
+ if let Some(&mut StackItem::Check { ref mut in_body, .. }) = self.stack.last_mut() {
+ *in_body = in_body.saturating_sub(1);
+ }
+ }
+
+ fn check_ty(&mut self, cx: &LateContext<'_>, hir_ty: &hir::Ty<'_>) {
+ if_chain! {
+ if !hir_ty.span.from_expansion();
+ if meets_msrv(self.msrv, msrvs::TYPE_ALIAS_ENUM_VARIANTS);
+ if let Some(&StackItem::Check {
+ impl_id,
+ in_body,
+ ref types_to_skip,
+ }) = self.stack.last();
+ if let TyKind::Path(QPath::Resolved(_, path)) = hir_ty.kind;
+ if !matches!(path.res, Res::SelfTy { .. } | Res::Def(DefKind::TyParam, _));
+ if !types_to_skip.contains(&hir_ty.hir_id);
+ let ty = if in_body > 0 {
+ cx.typeck_results().node_type(hir_ty.hir_id)
+ } else {
+ hir_ty_to_ty(cx.tcx, hir_ty)
+ };
+ if same_type_and_consts(ty, cx.tcx.type_of(impl_id));
+ let hir = cx.tcx.hir();
+ // prevents false positive on `#[derive(serde::Deserialize)]`
+ if !hir.span(hir.get_parent_node(hir_ty.hir_id)).in_derive_expansion();
+ then {
+ span_lint(cx, hir_ty.span);
+ }
+ }
+ }
+
+ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
+ if_chain! {
+ if !expr.span.from_expansion();
+ if meets_msrv(self.msrv, msrvs::TYPE_ALIAS_ENUM_VARIANTS);
+ if let Some(&StackItem::Check { impl_id, .. }) = self.stack.last();
+ if cx.typeck_results().expr_ty(expr) == cx.tcx.type_of(impl_id);
+ then {} else { return; }
+ }
+ match expr.kind {
+ ExprKind::Struct(QPath::Resolved(_, path), ..) => match path.res {
+ Res::SelfTy { .. } => (),
+ Res::Def(DefKind::Variant, _) => lint_path_to_variant(cx, path),
+ _ => span_lint(cx, path.span),
+ },
+ // tuple struct instantiation (`Foo(arg)` or `Enum::Foo(arg)`)
+ ExprKind::Call(fun, _) => {
+ if let ExprKind::Path(QPath::Resolved(_, path)) = fun.kind {
+ if let Res::Def(DefKind::Ctor(ctor_of, _), ..) = path.res {
+ match ctor_of {
+ CtorOf::Variant => lint_path_to_variant(cx, path),
+ CtorOf::Struct => span_lint(cx, path.span),
+ }
+ }
+ }
+ },
+ // unit enum variants (`Enum::A`)
+ ExprKind::Path(QPath::Resolved(_, path)) => lint_path_to_variant(cx, path),
+ _ => (),
+ }
+ }
+
+ fn check_pat(&mut self, cx: &LateContext<'_>, pat: &Pat<'_>) {
+ if_chain! {
+ if !pat.span.from_expansion();
+ if meets_msrv(self.msrv, msrvs::TYPE_ALIAS_ENUM_VARIANTS);
+ if let Some(&StackItem::Check { impl_id, .. }) = self.stack.last();
- if let [first, ..] = path.segments;
- if let Some(hir_id) = first.hir_id;
++ // get the path from the pattern
++ if let PatKind::Path(QPath::Resolved(_, path))
++ | PatKind::TupleStruct(QPath::Resolved(_, path), _, _)
++ | PatKind::Struct(QPath::Resolved(_, path), _, _) = pat.kind;
+ if cx.typeck_results().pat_ty(pat) == cx.tcx.type_of(impl_id);
- span_lint(cx, cx.tcx.hir().span(hir_id));
+ then {
++ match path.res {
++ Res::Def(DefKind::Ctor(ctor_of, _), ..) => match ctor_of {
++ CtorOf::Variant => lint_path_to_variant(cx, path),
++ CtorOf::Struct => span_lint(cx, path.span),
++ },
++ Res::Def(DefKind::Variant, ..) => lint_path_to_variant(cx, path),
++ Res::Def(DefKind::Struct, ..) => span_lint(cx, path.span),
++ _ => ()
++ }
+ }
+ }
+ }
+
+ extract_msrv_attr!(LateContext);
+}
+
+#[derive(Default)]
+struct SkipTyCollector {
+ types_to_skip: Vec<HirId>,
+}
+
+impl<'tcx> Visitor<'tcx> for SkipTyCollector {
+ fn visit_infer(&mut self, inf: &hir::InferArg) {
+ self.types_to_skip.push(inf.hir_id);
+
+ walk_inf(self, inf);
+ }
+ fn visit_ty(&mut self, hir_ty: &hir::Ty<'_>) {
+ self.types_to_skip.push(hir_ty.hir_id);
+
+ walk_ty(self, hir_ty);
+ }
+}
+
+fn span_lint(cx: &LateContext<'_>, span: Span) {
+ span_lint_and_sugg(
+ cx,
+ USE_SELF,
+ span,
+ "unnecessary structure name repetition",
+ "use the applicable keyword",
+ "Self".to_owned(),
+ Applicability::MachineApplicable,
+ );
+}
+
+fn lint_path_to_variant(cx: &LateContext<'_>, path: &Path<'_>) {
+ if let [.., self_seg, _variant] = path.segments {
+ let span = path
+ .span
+ .with_hi(self_seg.args().span_ext().unwrap_or(self_seg.ident.span).hi());
+ span_lint(cx, span);
+ }
+}
--- /dev/null
+//! Read configurations files.
+
+#![allow(clippy::module_name_repetitions)]
+
+use serde::de::{Deserializer, IgnoredAny, IntoDeserializer, MapAccess, Visitor};
+use serde::Deserialize;
+use std::error::Error;
+use std::path::{Path, PathBuf};
+use std::str::FromStr;
+use std::{cmp, env, fmt, fs, io, iter};
+
+/// Holds information used by `MISSING_ENFORCED_IMPORT_RENAMES` lint.
+#[derive(Clone, Debug, Deserialize)]
+pub struct Rename {
+ pub path: String,
+ pub rename: String,
+}
+
+/// A single disallowed method, used by the `DISALLOWED_METHODS` lint.
+#[derive(Clone, Debug, Deserialize)]
+#[serde(untagged)]
+pub enum DisallowedMethod {
+ Simple(String),
+ WithReason { path: String, reason: Option<String> },
+}
+
+impl DisallowedMethod {
+ pub fn path(&self) -> &str {
+ let (Self::Simple(path) | Self::WithReason { path, .. }) = self;
+
+ path
+ }
+}
+
+/// A single disallowed type, used by the `DISALLOWED_TYPES` lint.
+#[derive(Clone, Debug, Deserialize)]
+#[serde(untagged)]
+pub enum DisallowedType {
+ Simple(String),
+ WithReason { path: String, reason: Option<String> },
+}
+
+/// Conf with parse errors
+#[derive(Default)]
+pub struct TryConf {
+ pub conf: Conf,
+ pub errors: Vec<Box<dyn Error>>,
+}
+
+impl TryConf {
+ fn from_error(error: impl Error + 'static) -> Self {
+ Self {
+ conf: Conf::default(),
+ errors: vec![Box::new(error)],
+ }
+ }
+}
+
+#[derive(Debug)]
+struct ConfError(String);
+
+impl fmt::Display for ConfError {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ <String as fmt::Display>::fmt(&self.0, f)
+ }
+}
+
+impl Error for ConfError {}
+
+fn conf_error(s: String) -> Box<dyn Error> {
+ Box::new(ConfError(s))
+}
+
+macro_rules! define_Conf {
+ ($(
+ $(#[doc = $doc:literal])+
+ $(#[conf_deprecated($dep:literal)])?
+ ($name:ident: $ty:ty = $default:expr),
+ )*) => {
+ /// Clippy lint configuration
+ pub struct Conf {
+ $($(#[doc = $doc])+ pub $name: $ty,)*
+ }
+
+ mod defaults {
+ $(pub fn $name() -> $ty { $default })*
+ }
+
+ impl Default for Conf {
+ fn default() -> Self {
+ Self { $($name: defaults::$name(),)* }
+ }
+ }
+
+ impl<'de> Deserialize<'de> for TryConf {
+ fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'de> {
+ deserializer.deserialize_map(ConfVisitor)
+ }
+ }
+
+ #[derive(Deserialize)]
+ #[serde(field_identifier, rename_all = "kebab-case")]
+ #[allow(non_camel_case_types)]
+ enum Field { $($name,)* third_party, }
+
+ struct ConfVisitor;
+
+ impl<'de> Visitor<'de> for ConfVisitor {
+ type Value = TryConf;
+
+ fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+ formatter.write_str("Conf")
+ }
+
+ fn visit_map<V>(self, mut map: V) -> Result<Self::Value, V::Error> where V: MapAccess<'de> {
+ let mut errors = Vec::new();
+ $(let mut $name = None;)*
+ // could get `Field` here directly, but get `str` first for diagnostics
+ while let Some(name) = map.next_key::<&str>()? {
+ match Field::deserialize(name.into_deserializer())? {
+ $(Field::$name => {
+ $(errors.push(conf_error(format!("deprecated field `{}`. {}", name, $dep)));)?
+ match map.next_value() {
+ Err(e) => errors.push(conf_error(e.to_string())),
+ Ok(value) => match $name {
+ Some(_) => errors.push(conf_error(format!("duplicate field `{}`", name))),
+ None => $name = Some(value),
+ }
+ }
+ })*
+ // white-listed; ignore
+ Field::third_party => drop(map.next_value::<IgnoredAny>())
+ }
+ }
+ let conf = Conf { $($name: $name.unwrap_or_else(defaults::$name),)* };
+ Ok(TryConf { conf, errors })
+ }
+ }
+
+ #[cfg(feature = "internal")]
+ pub mod metadata {
+ use crate::utils::internal_lints::metadata_collector::ClippyConfiguration;
+
+ macro_rules! wrap_option {
+ () => (None);
+ ($x:literal) => (Some($x));
+ }
+
+ pub(crate) fn get_configuration_metadata() -> Vec<ClippyConfiguration> {
+ vec![
+ $(
+ {
+ let deprecation_reason = wrap_option!($($dep)?);
+
+ ClippyConfiguration::new(
+ stringify!($name),
+ stringify!($ty),
+ format!("{:?}", super::defaults::$name()),
+ concat!($($doc, '\n',)*),
+ deprecation_reason,
+ )
+ },
+ )+
+ ]
+ }
+ }
+ };
+}
+
+define_Conf! {
+ /// Lint: ENUM_VARIANT_NAMES, LARGE_TYPES_PASSED_BY_VALUE, TRIVIALLY_COPY_PASS_BY_REF, UNNECESSARY_WRAPS, UPPER_CASE_ACRONYMS, WRONG_SELF_CONVENTION, BOX_COLLECTION, REDUNDANT_ALLOCATION, RC_BUFFER, VEC_BOX, OPTION_OPTION, LINKEDLIST, RC_MUTEX.
+ ///
+ /// Suppress lints whenever the suggested change would cause breakage for other crates.
+ (avoid_breaking_exported_api: bool = true),
+ /// Lint: MANUAL_SPLIT_ONCE, MANUAL_STR_REPEAT, CLONED_INSTEAD_OF_COPIED, REDUNDANT_FIELD_NAMES, REDUNDANT_STATIC_LIFETIMES, FILTER_MAP_NEXT, CHECKED_CONVERSIONS, MANUAL_RANGE_CONTAINS, USE_SELF, MEM_REPLACE_WITH_DEFAULT, MANUAL_NON_EXHAUSTIVE, OPTION_AS_REF_DEREF, MAP_UNWRAP_OR, MATCH_LIKE_MATCHES_MACRO, MANUAL_STRIP, MISSING_CONST_FOR_FN, UNNESTED_OR_PATTERNS, FROM_OVER_INTO, PTR_AS_PTR, IF_THEN_SOME_ELSE_NONE, APPROX_CONSTANT, DEPRECATED_CFG_ATTR, INDEX_REFUTABLE_SLICE, MAP_CLONE, BORROW_AS_PTR, MANUAL_BITS, ERR_EXPECT, CAST_ABS_TO_UNSIGNED.
+ ///
+ /// The minimum rust version that the project supports
+ (msrv: Option<String> = None),
+ /// Lint: BLACKLISTED_NAME.
+ ///
+ /// The list of blacklisted names to lint about. NB: `bar` is not here since it has legitimate uses
+ (blacklisted_names: Vec<String> = ["foo", "baz", "quux"].iter().map(ToString::to_string).collect()),
+ /// Lint: COGNITIVE_COMPLEXITY.
+ ///
+ /// The maximum cognitive complexity a function can have
+ (cognitive_complexity_threshold: u64 = 25),
+ /// DEPRECATED LINT: CYCLOMATIC_COMPLEXITY.
+ ///
+ /// Use the Cognitive Complexity lint instead.
+ #[conf_deprecated("Please use `cognitive-complexity-threshold` instead")]
+ (cyclomatic_complexity_threshold: Option<u64> = None),
+ /// Lint: DOC_MARKDOWN.
+ ///
+ /// The list of words this lint should not consider as identifiers needing ticks
+ (doc_valid_idents: Vec<String> = [
+ "KiB", "MiB", "GiB", "TiB", "PiB", "EiB",
+ "DirectX",
+ "ECMAScript",
+ "GPLv2", "GPLv3",
+ "GitHub", "GitLab",
+ "IPv4", "IPv6",
+ "ClojureScript", "CoffeeScript", "JavaScript", "PureScript", "TypeScript",
+ "NaN", "NaNs",
+ "OAuth", "GraphQL",
+ "OCaml",
+ "OpenGL", "OpenMP", "OpenSSH", "OpenSSL", "OpenStreetMap", "OpenDNS",
+ "WebGL",
+ "TensorFlow",
+ "TrueType",
+ "iOS", "macOS", "FreeBSD",
+ "TeX", "LaTeX", "BibTeX", "BibLaTeX",
+ "MinGW",
+ "CamelCase",
+ ].iter().map(ToString::to_string).collect()),
+ /// Lint: TOO_MANY_ARGUMENTS.
+ ///
+ /// The maximum number of argument a function or method can have
+ (too_many_arguments_threshold: u64 = 7),
+ /// Lint: TYPE_COMPLEXITY.
+ ///
+ /// The maximum complexity a type can have
+ (type_complexity_threshold: u64 = 250),
+ /// Lint: MANY_SINGLE_CHAR_NAMES.
+ ///
+ /// The maximum number of single char bindings a scope may have
+ (single_char_binding_names_threshold: u64 = 4),
+ /// Lint: BOXED_LOCAL, USELESS_VEC.
+ ///
+ /// The maximum size of objects (in bytes) that will be linted. Larger objects are ok on the heap
+ (too_large_for_stack: u64 = 200),
+ /// Lint: ENUM_VARIANT_NAMES.
+ ///
+ /// The minimum number of enum variants for the lints about variant names to trigger
+ (enum_variant_name_threshold: u64 = 3),
+ /// Lint: LARGE_ENUM_VARIANT.
+ ///
+ /// The maximum size of an enum's variant to avoid box suggestion
+ (enum_variant_size_threshold: u64 = 200),
+ /// Lint: VERBOSE_BIT_MASK.
+ ///
+ /// The maximum allowed size of a bit mask before suggesting to use 'trailing_zeros'
+ (verbose_bit_mask_threshold: u64 = 1),
+ /// Lint: DECIMAL_LITERAL_REPRESENTATION.
+ ///
+ /// The lower bound for linting decimal literals
+ (literal_representation_threshold: u64 = 16384),
+ /// Lint: TRIVIALLY_COPY_PASS_BY_REF.
+ ///
+ /// The maximum size (in bytes) to consider a `Copy` type for passing by value instead of by reference.
+ (trivial_copy_size_limit: Option<u64> = None),
+ /// Lint: LARGE_TYPE_PASS_BY_MOVE.
+ ///
+ /// The minimum size (in bytes) to consider a type for passing by reference instead of by value.
+ (pass_by_value_size_limit: u64 = 256),
+ /// Lint: TOO_MANY_LINES.
+ ///
+ /// The maximum number of lines a function or method can have
+ (too_many_lines_threshold: u64 = 100),
+ /// Lint: LARGE_STACK_ARRAYS, LARGE_CONST_ARRAYS.
+ ///
+ /// The maximum allowed size for arrays on the stack
+ (array_size_threshold: u64 = 512_000),
+ /// Lint: VEC_BOX.
+ ///
+ /// The size of the boxed type in bytes, where boxing in a `Vec` is allowed
+ (vec_box_size_threshold: u64 = 4096),
+ /// Lint: TYPE_REPETITION_IN_BOUNDS.
+ ///
+ /// The maximum number of bounds a trait can have to be linted
+ (max_trait_bounds: u64 = 3),
+ /// Lint: STRUCT_EXCESSIVE_BOOLS.
+ ///
+ /// The maximum number of bool fields a struct can have
+ (max_struct_bools: u64 = 3),
+ /// Lint: FN_PARAMS_EXCESSIVE_BOOLS.
+ ///
+ /// The maximum number of bool parameters a function can have
+ (max_fn_params_bools: u64 = 3),
+ /// Lint: WILDCARD_IMPORTS.
+ ///
+ /// Whether to allow certain wildcard imports (prelude, super in tests).
+ (warn_on_all_wildcard_imports: bool = false),
+ /// Lint: DISALLOWED_METHODS.
+ ///
+ /// The list of disallowed methods, written as fully qualified paths.
+ (disallowed_methods: Vec<crate::utils::conf::DisallowedMethod> = Vec::new()),
+ /// Lint: DISALLOWED_TYPES.
+ ///
+ /// The list of disallowed types, written as fully qualified paths.
+ (disallowed_types: Vec<crate::utils::conf::DisallowedType> = Vec::new()),
+ /// Lint: UNREADABLE_LITERAL.
+ ///
+ /// Should the fraction of a decimal be linted to include separators.
+ (unreadable_literal_lint_fractions: bool = true),
+ /// Lint: UPPER_CASE_ACRONYMS.
+ ///
+ /// Enables verbose mode. Triggers if there is more than one uppercase char next to each other
+ (upper_case_acronyms_aggressive: bool = false),
+ /// Lint: _CARGO_COMMON_METADATA.
+ ///
+ /// For internal testing only, ignores the current `publish` settings in the Cargo manifest.
+ (cargo_ignore_publish: bool = false),
+ /// Lint: NONSTANDARD_MACRO_BRACES.
+ ///
+ /// Enforce the named macros always use the braces specified.
+ ///
+ /// A `MacroMatcher` can be added like so `{ name = "macro_name", brace = "(" }`. If the macro
+ /// is could be used with a full path two `MacroMatcher`s have to be added one with the full path
+ /// `crate_name::macro_name` and one with just the macro name.
+ (standard_macro_braces: Vec<crate::nonstandard_macro_braces::MacroMatcher> = Vec::new()),
+ /// Lint: MISSING_ENFORCED_IMPORT_RENAMES.
+ ///
+ /// The list of imports to always rename, a fully qualified path followed by the rename.
+ (enforced_import_renames: Vec<crate::utils::conf::Rename> = Vec::new()),
+ /// Lint: DISALLOWED_SCRIPT_IDENTS.
+ ///
+ /// The list of unicode scripts allowed to be used in the scope.
+ (allowed_scripts: Vec<String> = ["Latin"].iter().map(ToString::to_string).collect()),
+ /// Lint: NON_SEND_FIELDS_IN_SEND_TY.
+ ///
+ /// Whether to apply the raw pointer heuristic to determine if a type is `Send`.
+ (enable_raw_pointer_heuristic_for_send: bool = true),
+ /// Lint: INDEX_REFUTABLE_SLICE.
+ ///
+ /// When Clippy suggests using a slice pattern, this is the maximum number of elements allowed in
+ /// the slice pattern that is suggested. If more elements would be necessary, the lint is suppressed.
+ /// For example, `[_, _, _, e, ..]` is a slice pattern with 4 elements.
+ (max_suggested_slice_pattern_length: u64 = 3),
+ /// Lint: AWAIT_HOLDING_INVALID_TYPE
+ (await_holding_invalid_types: Vec<crate::utils::conf::DisallowedType> = Vec::new()),
+ /// Lint: LARGE_INCLUDE_FILE.
+ ///
+ /// The maximum size of a file included via `include_bytes!()` or `include_str!()`, in bytes
+ (max_include_file_size: u64 = 1_000_000),
+ /// Lint: EXPECT_USED.
+ ///
+ /// Whether `expect` should be allowed in test functions
+ (allow_expect_in_tests: bool = false),
+ /// Lint: UNWRAP_USED.
+ ///
+ /// Whether `unwrap` should be allowed in test functions
+ (allow_unwrap_in_tests: bool = false),
++ /// Lint: DBG_MACRO.
++ ///
++ /// Whether `dbg!` should be allowed in test functions
++ (allow_dbg_in_tests: bool = false),
+}
+
+/// Search for the configuration file.
+pub fn lookup_conf_file() -> io::Result<Option<PathBuf>> {
+ /// Possible filename to search for.
+ const CONFIG_FILE_NAMES: [&str; 2] = [".clippy.toml", "clippy.toml"];
+
+ // Start looking for a config file in CLIPPY_CONF_DIR, or failing that, CARGO_MANIFEST_DIR.
+ // If neither of those exist, use ".".
+ let mut current = env::var_os("CLIPPY_CONF_DIR")
+ .or_else(|| env::var_os("CARGO_MANIFEST_DIR"))
+ .map_or_else(|| PathBuf::from("."), PathBuf::from);
+
+ let mut found_config: Option<PathBuf> = None;
+
+ loop {
+ for config_file_name in &CONFIG_FILE_NAMES {
+ if let Ok(config_file) = current.join(config_file_name).canonicalize() {
+ match fs::metadata(&config_file) {
+ Err(e) if e.kind() == io::ErrorKind::NotFound => {},
+ Err(e) => return Err(e),
+ Ok(md) if md.is_dir() => {},
+ Ok(_) => {
+ // warn if we happen to find two config files #8323
+ if let Some(ref found_config_) = found_config {
+ eprintln!(
+ "Using config file `{}`\nWarning: `{}` will be ignored.",
+ found_config_.display(),
+ config_file.display(),
+ );
+ } else {
+ found_config = Some(config_file);
+ }
+ },
+ }
+ }
+ }
+
+ if found_config.is_some() {
+ return Ok(found_config);
+ }
+
+ // If the current directory has no parent, we're done searching.
+ if !current.pop() {
+ return Ok(None);
+ }
+ }
+}
+
+/// Read the `toml` configuration file.
+///
+/// In case of error, the function tries to continue as much as possible.
+pub fn read(path: &Path) -> TryConf {
+ let content = match fs::read_to_string(path) {
+ Err(e) => return TryConf::from_error(e),
+ Ok(content) => content,
+ };
+ toml::from_str(&content).unwrap_or_else(TryConf::from_error)
+}
+
+const SEPARATOR_WIDTH: usize = 4;
+
+// Check whether the error is "unknown field" and, if so, list the available fields sorted and at
+// least one per line, more if `CLIPPY_TERMINAL_WIDTH` is set and allows it.
+pub fn format_error(error: Box<dyn Error>) -> String {
+ let s = error.to_string();
+
+ if_chain! {
+ if error.downcast::<toml::de::Error>().is_ok();
+ if let Some((prefix, mut fields, suffix)) = parse_unknown_field_message(&s);
+ then {
+ use fmt::Write;
+
+ fields.sort_unstable();
+
+ let (rows, column_widths) = calculate_dimensions(&fields);
+
+ let mut msg = String::from(prefix);
+ for row in 0..rows {
+ write!(msg, "\n").unwrap();
+ for (column, column_width) in column_widths.iter().copied().enumerate() {
+ let index = column * rows + row;
+ let field = fields.get(index).copied().unwrap_or_default();
+ write!(
+ msg,
+ "{:separator_width$}{:field_width$}",
+ " ",
+ field,
+ separator_width = SEPARATOR_WIDTH,
+ field_width = column_width
+ )
+ .unwrap();
+ }
+ }
+ write!(msg, "\n{}", suffix).unwrap();
+ msg
+ } else {
+ s
+ }
+ }
+}
+
+// `parse_unknown_field_message` will become unnecessary if
+// https://github.com/alexcrichton/toml-rs/pull/364 is merged.
+fn parse_unknown_field_message(s: &str) -> Option<(&str, Vec<&str>, &str)> {
+ // An "unknown field" message has the following form:
+ // unknown field `UNKNOWN`, expected one of `FIELD0`, `FIELD1`, ..., `FIELDN` at line X column Y
+ // ^^ ^^^^ ^^
+ if_chain! {
+ if s.starts_with("unknown field");
+ let slices = s.split("`, `").collect::<Vec<_>>();
+ let n = slices.len();
+ if n >= 2;
+ if let Some((prefix, first_field)) = slices[0].rsplit_once(" `");
+ if let Some((last_field, suffix)) = slices[n - 1].split_once("` ");
+ then {
+ let fields = iter::once(first_field)
+ .chain(slices[1..n - 1].iter().copied())
+ .chain(iter::once(last_field))
+ .collect::<Vec<_>>();
+ Some((prefix, fields, suffix))
+ } else {
+ None
+ }
+ }
+}
+
+fn calculate_dimensions(fields: &[&str]) -> (usize, Vec<usize>) {
+ let columns = env::var("CLIPPY_TERMINAL_WIDTH")
+ .ok()
+ .and_then(|s| <usize as FromStr>::from_str(&s).ok())
+ .map_or(1, |terminal_width| {
+ let max_field_width = fields.iter().map(|field| field.len()).max().unwrap();
+ cmp::max(1, terminal_width / (SEPARATOR_WIDTH + max_field_width))
+ });
+
+ let rows = (fields.len() + (columns - 1)) / columns;
+
+ let column_widths = (0..columns)
+ .map(|column| {
+ if column < columns - 1 {
+ (0..rows)
+ .map(|row| {
+ let index = column * rows + row;
+ let field = fields.get(index).copied().unwrap_or_default();
+ field.len()
+ })
+ .max()
+ .unwrap()
+ } else {
+ // Avoid adding extra space to the last column.
+ 0
+ }
+ })
+ .collect::<Vec<_>>();
+
+ (rows, column_widths)
+}
--- /dev/null
- &*cx.tcx.item_name(macro_call.def_id).as_str(),
+use clippy_utils::consts::{constant_simple, Constant};
+use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::macros::root_macro_call_first_node;
+use clippy_utils::source::snippet;
+use clippy_utils::ty::match_type;
+use clippy_utils::{
+ def_path_res, higher, is_else_clause, is_expn_of, is_expr_path_def_path, is_lint_allowed, match_def_path,
+ method_calls, paths, peel_blocks_with_stmt, SpanlessEq,
+};
+use if_chain::if_chain;
+use rustc_ast as ast;
+use rustc_ast::ast::{Crate, ItemKind, LitKind, ModKind, NodeId};
+use rustc_ast::visit::FnKind;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::def_id::DefId;
+use rustc_hir::hir_id::CRATE_HIR_ID;
+use rustc_hir::intravisit::Visitor;
+use rustc_hir::{
+ BinOpKind, Block, Expr, ExprKind, HirId, Item, Local, MutTy, Mutability, Node, Path, Stmt, StmtKind, Ty, TyKind,
+ UnOp,
+};
+use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::nested_filter;
+use rustc_middle::mir::interpret::ConstValue;
+use rustc_middle::ty::{self, fast_reject::SimplifiedTypeGen, subst::GenericArgKind, FloatTy};
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Spanned;
+use rustc_span::symbol::Symbol;
+use rustc_span::{sym, BytePos, Span};
+use rustc_typeck::hir_ty_to_ty;
+
+use std::borrow::{Borrow, Cow};
+
+#[cfg(feature = "internal")]
+pub mod metadata_collector;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for various things we like to keep tidy in clippy.
+ ///
+ /// ### Why is this bad?
+ /// We like to pretend we're an example of tidy code.
+ ///
+ /// ### Example
+ /// Wrong ordering of the util::paths constants.
+ pub CLIPPY_LINTS_INTERNAL,
+ internal,
+ "various things that will negatively affect your clippy experience"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Ensures every lint is associated to a `LintPass`.
+ ///
+ /// ### Why is this bad?
+ /// The compiler only knows lints via a `LintPass`. Without
+ /// putting a lint to a `LintPass::get_lints()`'s return, the compiler will not
+ /// know the name of the lint.
+ ///
+ /// ### Known problems
+ /// Only checks for lints associated using the
+ /// `declare_lint_pass!`, `impl_lint_pass!`, and `lint_array!` macros.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// declare_lint! { pub LINT_1, ... }
+ /// declare_lint! { pub LINT_2, ... }
+ /// declare_lint! { pub FORGOTTEN_LINT, ... }
+ /// // ...
+ /// declare_lint_pass!(Pass => [LINT_1, LINT_2]);
+ /// // missing FORGOTTEN_LINT
+ /// ```
+ pub LINT_WITHOUT_LINT_PASS,
+ internal,
+ "declaring a lint without associating it in a LintPass"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calls to `cx.span_lint*` and suggests to use the `utils::*`
+ /// variant of the function.
+ ///
+ /// ### Why is this bad?
+ /// The `utils::*` variants also add a link to the Clippy documentation to the
+ /// warning/error messages.
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust,ignore
+ /// cx.span_lint(LINT_NAME, "message");
+ /// ```
+ ///
+ /// Good:
+ /// ```rust,ignore
+ /// utils::span_lint(cx, LINT_NAME, "message");
+ /// ```
+ pub COMPILER_LINT_FUNCTIONS,
+ internal,
+ "usage of the lint functions of the compiler instead of the utils::* variant"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calls to `cx.outer().expn_data()` and suggests to use
+ /// the `cx.outer_expn_data()`
+ ///
+ /// ### Why is this bad?
+ /// `cx.outer_expn_data()` is faster and more concise.
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust,ignore
+ /// expr.span.ctxt().outer().expn_data()
+ /// ```
+ ///
+ /// Good:
+ /// ```rust,ignore
+ /// expr.span.ctxt().outer_expn_data()
+ /// ```
+ pub OUTER_EXPN_EXPN_DATA,
+ internal,
+ "using `cx.outer_expn().expn_data()` instead of `cx.outer_expn_data()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Not an actual lint. This lint is only meant for testing our customized internal compiler
+ /// error message by calling `panic`.
+ ///
+ /// ### Why is this bad?
+ /// ICE in large quantities can damage your teeth
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust,ignore
+ /// 🍦🍦🍦🍦🍦
+ /// ```
+ pub PRODUCE_ICE,
+ internal,
+ "this message should not appear anywhere as we ICE before and don't emit the lint"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for cases of an auto-generated lint without an updated description,
+ /// i.e. `default lint description`.
+ ///
+ /// ### Why is this bad?
+ /// Indicates that the lint is not finished.
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust,ignore
+ /// declare_lint! { pub COOL_LINT, nursery, "default lint description" }
+ /// ```
+ ///
+ /// Good:
+ /// ```rust,ignore
+ /// declare_lint! { pub COOL_LINT, nursery, "a great new lint" }
+ /// ```
+ pub DEFAULT_LINT,
+ internal,
+ "found 'default lint description' in a lint declaration"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Lints `span_lint_and_then` function calls, where the
+ /// closure argument has only one statement and that statement is a method
+ /// call to `span_suggestion`, `span_help`, `span_note` (using the same
+ /// span), `help` or `note`.
+ ///
+ /// These usages of `span_lint_and_then` should be replaced with one of the
+ /// wrapper functions `span_lint_and_sugg`, span_lint_and_help`, or
+ /// `span_lint_and_note`.
+ ///
+ /// ### Why is this bad?
+ /// Using the wrapper `span_lint_and_*` functions, is more
+ /// convenient, readable and less error prone.
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust,ignore
+ /// span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |diag| {
+ /// diag.span_suggestion(
+ /// expr.span,
+ /// help_msg,
+ /// sugg.to_string(),
+ /// Applicability::MachineApplicable,
+ /// );
+ /// });
+ /// span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |diag| {
+ /// diag.span_help(expr.span, help_msg);
+ /// });
+ /// span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |diag| {
+ /// diag.help(help_msg);
+ /// });
+ /// span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |diag| {
+ /// diag.span_note(expr.span, note_msg);
+ /// });
+ /// span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |diag| {
+ /// diag.note(note_msg);
+ /// });
+ /// ```
+ ///
+ /// Good:
+ /// ```rust,ignore
+ /// span_lint_and_sugg(
+ /// cx,
+ /// TEST_LINT,
+ /// expr.span,
+ /// lint_msg,
+ /// help_msg,
+ /// sugg.to_string(),
+ /// Applicability::MachineApplicable,
+ /// );
+ /// span_lint_and_help(cx, TEST_LINT, expr.span, lint_msg, Some(expr.span), help_msg);
+ /// span_lint_and_help(cx, TEST_LINT, expr.span, lint_msg, None, help_msg);
+ /// span_lint_and_note(cx, TEST_LINT, expr.span, lint_msg, Some(expr.span), note_msg);
+ /// span_lint_and_note(cx, TEST_LINT, expr.span, lint_msg, None, note_msg);
+ /// ```
+ pub COLLAPSIBLE_SPAN_LINT_CALLS,
+ internal,
+ "found collapsible `span_lint_and_then` calls"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calls to `utils::match_type()` on a type diagnostic item
+ /// and suggests to use `utils::is_type_diagnostic_item()` instead.
+ ///
+ /// ### Why is this bad?
+ /// `utils::is_type_diagnostic_item()` does not require hardcoded paths.
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust,ignore
+ /// utils::match_type(cx, ty, &paths::VEC)
+ /// ```
+ ///
+ /// Good:
+ /// ```rust,ignore
+ /// utils::is_type_diagnostic_item(cx, ty, sym::Vec)
+ /// ```
+ pub MATCH_TYPE_ON_DIAGNOSTIC_ITEM,
+ internal,
+ "using `utils::match_type()` instead of `utils::is_type_diagnostic_item()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks the paths module for invalid paths.
+ ///
+ /// ### Why is this bad?
+ /// It indicates a bug in the code.
+ ///
+ /// ### Example
+ /// None.
+ pub INVALID_PATHS,
+ internal,
+ "invalid path"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for interning symbols that have already been pre-interned and defined as constants.
+ ///
+ /// ### Why is this bad?
+ /// It's faster and easier to use the symbol constant.
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust,ignore
+ /// let _ = sym!(f32);
+ /// ```
+ ///
+ /// Good:
+ /// ```rust,ignore
+ /// let _ = sym::f32;
+ /// ```
+ pub INTERNING_DEFINED_SYMBOL,
+ internal,
+ "interning a symbol that is pre-interned and defined as a constant"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for unnecessary conversion from Symbol to a string.
+ ///
+ /// ### Why is this bad?
+ /// It's faster use symbols directly instead of strings.
+ ///
+ /// ### Example
+ /// Bad:
+ /// ```rust,ignore
+ /// symbol.as_str() == "clippy";
+ /// ```
+ ///
+ /// Good:
+ /// ```rust,ignore
+ /// symbol == sym::clippy;
+ /// ```
+ pub UNNECESSARY_SYMBOL_STR,
+ internal,
+ "unnecessary conversion between Symbol and string"
+}
+
+declare_clippy_lint! {
+ /// Finds unidiomatic usage of `if_chain!`
+ pub IF_CHAIN_STYLE,
+ internal,
+ "non-idiomatic `if_chain!` usage"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for invalid `clippy::version` attributes.
+ ///
+ /// Valid values are:
+ /// * "pre 1.29.0"
+ /// * any valid semantic version
+ pub INVALID_CLIPPY_VERSION_ATTRIBUTE,
+ internal,
+ "found an invalid `clippy::version` attribute"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for declared clippy lints without the `clippy::version` attribute.
+ ///
+ pub MISSING_CLIPPY_VERSION_ATTRIBUTE,
+ internal,
+ "found clippy lint without `clippy::version` attribute"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Check that the `extract_msrv_attr!` macro is used, when a lint has a MSRV.
+ ///
+ pub MISSING_MSRV_ATTR_IMPL,
+ internal,
+ "checking if all necessary steps were taken when adding a MSRV to a lint"
+}
+
+declare_lint_pass!(ClippyLintsInternal => [CLIPPY_LINTS_INTERNAL]);
+
+impl EarlyLintPass for ClippyLintsInternal {
+ fn check_crate(&mut self, cx: &EarlyContext<'_>, krate: &Crate) {
+ if let Some(utils) = krate.items.iter().find(|item| item.ident.name.as_str() == "utils") {
+ if let ItemKind::Mod(_, ModKind::Loaded(ref items, ..)) = utils.kind {
+ if let Some(paths) = items.iter().find(|item| item.ident.name.as_str() == "paths") {
+ if let ItemKind::Mod(_, ModKind::Loaded(ref items, ..)) = paths.kind {
+ let mut last_name: Option<&str> = None;
+ for item in items {
+ let name = item.ident.as_str();
+ if let Some(last_name) = last_name {
+ if *last_name > *name {
+ span_lint(
+ cx,
+ CLIPPY_LINTS_INTERNAL,
+ item.span,
+ "this constant should be before the previous constant due to lexical \
+ ordering",
+ );
+ }
+ }
+ last_name = Some(name);
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+#[derive(Clone, Debug, Default)]
+pub struct LintWithoutLintPass {
+ declared_lints: FxHashMap<Symbol, Span>,
+ registered_lints: FxHashSet<Symbol>,
+}
+
+impl_lint_pass!(LintWithoutLintPass => [DEFAULT_LINT, LINT_WITHOUT_LINT_PASS, INVALID_CLIPPY_VERSION_ATTRIBUTE, MISSING_CLIPPY_VERSION_ATTRIBUTE]);
+
+impl<'tcx> LateLintPass<'tcx> for LintWithoutLintPass {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
+ if is_lint_allowed(cx, DEFAULT_LINT, item.hir_id()) {
+ return;
+ }
+
+ if let hir::ItemKind::Static(ty, Mutability::Not, body_id) = item.kind {
+ if is_lint_ref_type(cx, ty) {
+ check_invalid_clippy_version_attribute(cx, item);
+
+ let expr = &cx.tcx.hir().body(body_id).value;
+ if_chain! {
+ if let ExprKind::AddrOf(_, _, inner_exp) = expr.kind;
+ if let ExprKind::Struct(_, fields, _) = inner_exp.kind;
+ let field = fields
+ .iter()
+ .find(|f| f.ident.as_str() == "desc")
+ .expect("lints must have a description field");
+ if let ExprKind::Lit(Spanned {
+ node: LitKind::Str(ref sym, _),
+ ..
+ }) = field.expr.kind;
+ if sym.as_str() == "default lint description";
+
+ then {
+ span_lint(
+ cx,
+ DEFAULT_LINT,
+ item.span,
+ &format!("the lint `{}` has the default lint description", item.ident.name),
+ );
+ }
+ }
+ self.declared_lints.insert(item.ident.name, item.span);
+ }
+ } else if let Some(macro_call) = root_macro_call_first_node(cx, item) {
+ if !matches!(
- if RustcVersion::parse(&*value.as_str()).is_err() {
++ cx.tcx.item_name(macro_call.def_id).as_str(),
+ "impl_lint_pass" | "declare_lint_pass"
+ ) {
+ return;
+ }
+ if let hir::ItemKind::Impl(hir::Impl {
+ of_trait: None,
+ items: impl_item_refs,
+ ..
+ }) = item.kind
+ {
+ let mut collector = LintCollector {
+ output: &mut self.registered_lints,
+ cx,
+ };
+ let body_id = cx.tcx.hir().body_owned_by(
+ impl_item_refs
+ .iter()
+ .find(|iiref| iiref.ident.as_str() == "get_lints")
+ .expect("LintPass needs to implement get_lints")
+ .id
+ .hir_id(),
+ );
+ collector.visit_expr(&cx.tcx.hir().body(body_id).value);
+ }
+ }
+ }
+
+ fn check_crate_post(&mut self, cx: &LateContext<'tcx>) {
+ if is_lint_allowed(cx, LINT_WITHOUT_LINT_PASS, CRATE_HIR_ID) {
+ return;
+ }
+
+ for (lint_name, &lint_span) in &self.declared_lints {
+ // When using the `declare_tool_lint!` macro, the original `lint_span`'s
+ // file points to "<rustc macros>".
+ // `compiletest-rs` thinks that's an error in a different file and
+ // just ignores it. This causes the test in compile-fail/lint_pass
+ // not able to capture the error.
+ // Therefore, we need to climb the macro expansion tree and find the
+ // actual span that invoked `declare_tool_lint!`:
+ let lint_span = lint_span.ctxt().outer_expn_data().call_site;
+
+ if !self.registered_lints.contains(lint_name) {
+ span_lint(
+ cx,
+ LINT_WITHOUT_LINT_PASS,
+ lint_span,
+ &format!("the lint `{}` is not added to any `LintPass`", lint_name),
+ );
+ }
+ }
+ }
+}
+
+fn is_lint_ref_type<'tcx>(cx: &LateContext<'tcx>, ty: &Ty<'_>) -> bool {
+ if let TyKind::Rptr(
+ _,
+ MutTy {
+ ty: inner,
+ mutbl: Mutability::Not,
+ },
+ ) = ty.kind
+ {
+ if let TyKind::Path(ref path) = inner.kind {
+ if let Res::Def(DefKind::Struct, def_id) = cx.qpath_res(path, inner.hir_id) {
+ return match_def_path(cx, def_id, &paths::LINT);
+ }
+ }
+ }
+
+ false
+}
+
+fn check_invalid_clippy_version_attribute(cx: &LateContext<'_>, item: &'_ Item<'_>) {
+ if let Some(value) = extract_clippy_version_value(cx, item) {
+ // The `sym!` macro doesn't work as it only expects a single token.
+ // It's better to keep it this way and have a direct `Symbol::intern` call here.
+ if value == Symbol::intern("pre 1.29.0") {
+ return;
+ }
+
- if let Some(sugg) = self.map.get(&*fn_name.as_str());
++ if RustcVersion::parse(value.as_str()).is_err() {
+ span_lint_and_help(
+ cx,
+ INVALID_CLIPPY_VERSION_ATTRIBUTE,
+ item.span,
+ "this item has an invalid `clippy::version` attribute",
+ None,
+ "please use a valid sematic version, see `doc/adding_lints.md`",
+ );
+ }
+ } else {
+ span_lint_and_help(
+ cx,
+ MISSING_CLIPPY_VERSION_ATTRIBUTE,
+ item.span,
+ "this lint is missing the `clippy::version` attribute or version value",
+ None,
+ "please use a `clippy::version` attribute, see `doc/adding_lints.md`",
+ );
+ }
+}
+
+/// This function extracts the version value of a `clippy::version` attribute if the given value has
+/// one
+fn extract_clippy_version_value(cx: &LateContext<'_>, item: &'_ Item<'_>) -> Option<Symbol> {
+ let attrs = cx.tcx.hir().attrs(item.hir_id());
+ attrs.iter().find_map(|attr| {
+ if_chain! {
+ // Identify attribute
+ if let ast::AttrKind::Normal(ref attr_kind, _) = &attr.kind;
+ if let [tool_name, attr_name] = &attr_kind.path.segments[..];
+ if tool_name.ident.name == sym::clippy;
+ if attr_name.ident.name == sym::version;
+ if let Some(version) = attr.value_str();
+ then {
+ Some(version)
+ } else {
+ None
+ }
+ }
+ })
+}
+
+struct LintCollector<'a, 'tcx> {
+ output: &'a mut FxHashSet<Symbol>,
+ cx: &'a LateContext<'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for LintCollector<'a, 'tcx> {
+ type NestedFilter = nested_filter::All;
+
+ fn visit_path(&mut self, path: &'tcx Path<'_>, _: HirId) {
+ if path.segments.len() == 1 {
+ self.output.insert(path.segments[0].ident.name);
+ }
+ }
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+}
+
+#[derive(Clone, Default)]
+pub struct CompilerLintFunctions {
+ map: FxHashMap<&'static str, &'static str>,
+}
+
+impl CompilerLintFunctions {
+ #[must_use]
+ pub fn new() -> Self {
+ let mut map = FxHashMap::default();
+ map.insert("span_lint", "utils::span_lint");
+ map.insert("struct_span_lint", "utils::span_lint");
+ map.insert("lint", "utils::span_lint");
+ map.insert("span_lint_note", "utils::span_lint_and_note");
+ map.insert("span_lint_help", "utils::span_lint_and_help");
+ Self { map }
+ }
+}
+
+impl_lint_pass!(CompilerLintFunctions => [COMPILER_LINT_FUNCTIONS]);
+
+impl<'tcx> LateLintPass<'tcx> for CompilerLintFunctions {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if is_lint_allowed(cx, COMPILER_LINT_FUNCTIONS, expr.hir_id) {
+ return;
+ }
+
+ if_chain! {
+ if let ExprKind::MethodCall(path, [self_arg, ..], _) = &expr.kind;
+ let fn_name = path.ident;
- match &*ps.ident.as_str() {
++ if let Some(sugg) = self.map.get(fn_name.as_str());
+ let ty = cx.typeck_results().expr_ty(self_arg).peel_refs();
+ if match_type(cx, ty, &paths::EARLY_CONTEXT)
+ || match_type(cx, ty, &paths::LATE_CONTEXT);
+ then {
+ span_lint_and_help(
+ cx,
+ COMPILER_LINT_FUNCTIONS,
+ path.ident.span,
+ "usage of a compiler lint function",
+ None,
+ &format!("please use the Clippy variant of this function: `{}`", sugg),
+ );
+ }
+ }
+ }
+}
+
+declare_lint_pass!(OuterExpnDataPass => [OUTER_EXPN_EXPN_DATA]);
+
+impl<'tcx> LateLintPass<'tcx> for OuterExpnDataPass {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
+ if is_lint_allowed(cx, OUTER_EXPN_EXPN_DATA, expr.hir_id) {
+ return;
+ }
+
+ let (method_names, arg_lists, spans) = method_calls(expr, 2);
+ let method_names: Vec<&str> = method_names.iter().map(Symbol::as_str).collect();
+ if_chain! {
+ if let ["expn_data", "outer_expn"] = method_names.as_slice();
+ let args = arg_lists[1];
+ if args.len() == 1;
+ let self_arg = &args[0];
+ let self_ty = cx.typeck_results().expr_ty(self_arg).peel_refs();
+ if match_type(cx, self_ty, &paths::SYNTAX_CONTEXT);
+ then {
+ span_lint_and_sugg(
+ cx,
+ OUTER_EXPN_EXPN_DATA,
+ spans[1].with_hi(expr.span.hi()),
+ "usage of `outer_expn().expn_data()`",
+ "try",
+ "outer_expn_data()".to_string(),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ }
+}
+
+declare_lint_pass!(ProduceIce => [PRODUCE_ICE]);
+
+impl EarlyLintPass for ProduceIce {
+ fn check_fn(&mut self, _: &EarlyContext<'_>, fn_kind: FnKind<'_>, _: Span, _: NodeId) {
+ assert!(!is_trigger_fn(fn_kind), "Would you like some help with that?");
+ }
+}
+
+fn is_trigger_fn(fn_kind: FnKind<'_>) -> bool {
+ match fn_kind {
+ FnKind::Fn(_, ident, ..) => ident.name.as_str() == "it_looks_like_you_are_trying_to_kill_clippy",
+ FnKind::Closure(..) => false,
+ }
+}
+
+declare_lint_pass!(CollapsibleCalls => [COLLAPSIBLE_SPAN_LINT_CALLS]);
+
+impl<'tcx> LateLintPass<'tcx> for CollapsibleCalls {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
+ if is_lint_allowed(cx, COLLAPSIBLE_SPAN_LINT_CALLS, expr.hir_id) {
+ return;
+ }
+
+ if_chain! {
+ if let ExprKind::Call(func, and_then_args) = expr.kind;
+ if is_expr_path_def_path(cx, func, &["clippy_utils", "diagnostics", "span_lint_and_then"]);
+ if and_then_args.len() == 5;
+ if let ExprKind::Closure(_, _, body_id, _, _) = &and_then_args[4].kind;
+ let body = cx.tcx.hir().body(*body_id);
+ let only_expr = peel_blocks_with_stmt(&body.value);
+ if let ExprKind::MethodCall(ps, span_call_args, _) = &only_expr.kind;
+ then {
+ let and_then_snippets = get_and_then_snippets(cx, and_then_args);
+ let mut sle = SpanlessEq::new(cx).deny_side_effects();
++ match ps.ident.as_str() {
+ "span_suggestion" if sle.eq_expr(&and_then_args[2], &span_call_args[1]) => {
+ suggest_suggestion(cx, expr, &and_then_snippets, &span_suggestion_snippets(cx, span_call_args));
+ },
+ "span_help" if sle.eq_expr(&and_then_args[2], &span_call_args[1]) => {
+ let help_snippet = snippet(cx, span_call_args[2].span, r#""...""#);
+ suggest_help(cx, expr, &and_then_snippets, help_snippet.borrow(), true);
+ },
+ "span_note" if sle.eq_expr(&and_then_args[2], &span_call_args[1]) => {
+ let note_snippet = snippet(cx, span_call_args[2].span, r#""...""#);
+ suggest_note(cx, expr, &and_then_snippets, note_snippet.borrow(), true);
+ },
+ "help" => {
+ let help_snippet = snippet(cx, span_call_args[1].span, r#""...""#);
+ suggest_help(cx, expr, &and_then_snippets, help_snippet.borrow(), false);
+ }
+ "note" => {
+ let note_snippet = snippet(cx, span_call_args[1].span, r#""...""#);
+ suggest_note(cx, expr, &and_then_snippets, note_snippet.borrow(), false);
+ }
+ _ => (),
+ }
+ }
+ }
+ }
+}
+
+struct AndThenSnippets<'a> {
+ cx: Cow<'a, str>,
+ lint: Cow<'a, str>,
+ span: Cow<'a, str>,
+ msg: Cow<'a, str>,
+}
+
+fn get_and_then_snippets<'a, 'hir>(cx: &LateContext<'_>, and_then_snippets: &'hir [Expr<'hir>]) -> AndThenSnippets<'a> {
+ let cx_snippet = snippet(cx, and_then_snippets[0].span, "cx");
+ let lint_snippet = snippet(cx, and_then_snippets[1].span, "..");
+ let span_snippet = snippet(cx, and_then_snippets[2].span, "span");
+ let msg_snippet = snippet(cx, and_then_snippets[3].span, r#""...""#);
+
+ AndThenSnippets {
+ cx: cx_snippet,
+ lint: lint_snippet,
+ span: span_snippet,
+ msg: msg_snippet,
+ }
+}
+
+struct SpanSuggestionSnippets<'a> {
+ help: Cow<'a, str>,
+ sugg: Cow<'a, str>,
+ applicability: Cow<'a, str>,
+}
+
+fn span_suggestion_snippets<'a, 'hir>(
+ cx: &LateContext<'_>,
+ span_call_args: &'hir [Expr<'hir>],
+) -> SpanSuggestionSnippets<'a> {
+ let help_snippet = snippet(cx, span_call_args[2].span, r#""...""#);
+ let sugg_snippet = snippet(cx, span_call_args[3].span, "..");
+ let applicability_snippet = snippet(cx, span_call_args[4].span, "Applicability::MachineApplicable");
+
+ SpanSuggestionSnippets {
+ help: help_snippet,
+ sugg: sugg_snippet,
+ applicability: applicability_snippet,
+ }
+}
+
+fn suggest_suggestion(
+ cx: &LateContext<'_>,
+ expr: &Expr<'_>,
+ and_then_snippets: &AndThenSnippets<'_>,
+ span_suggestion_snippets: &SpanSuggestionSnippets<'_>,
+) {
+ span_lint_and_sugg(
+ cx,
+ COLLAPSIBLE_SPAN_LINT_CALLS,
+ expr.span,
+ "this call is collapsible",
+ "collapse into",
+ format!(
+ "span_lint_and_sugg({}, {}, {}, {}, {}, {}, {})",
+ and_then_snippets.cx,
+ and_then_snippets.lint,
+ and_then_snippets.span,
+ and_then_snippets.msg,
+ span_suggestion_snippets.help,
+ span_suggestion_snippets.sugg,
+ span_suggestion_snippets.applicability
+ ),
+ Applicability::MachineApplicable,
+ );
+}
+
+fn suggest_help(
+ cx: &LateContext<'_>,
+ expr: &Expr<'_>,
+ and_then_snippets: &AndThenSnippets<'_>,
+ help: &str,
+ with_span: bool,
+) {
+ let option_span = if with_span {
+ format!("Some({})", and_then_snippets.span)
+ } else {
+ "None".to_string()
+ };
+
+ span_lint_and_sugg(
+ cx,
+ COLLAPSIBLE_SPAN_LINT_CALLS,
+ expr.span,
+ "this call is collapsible",
+ "collapse into",
+ format!(
+ "span_lint_and_help({}, {}, {}, {}, {}, {})",
+ and_then_snippets.cx,
+ and_then_snippets.lint,
+ and_then_snippets.span,
+ and_then_snippets.msg,
+ &option_span,
+ help
+ ),
+ Applicability::MachineApplicable,
+ );
+}
+
+fn suggest_note(
+ cx: &LateContext<'_>,
+ expr: &Expr<'_>,
+ and_then_snippets: &AndThenSnippets<'_>,
+ note: &str,
+ with_span: bool,
+) {
+ let note_span = if with_span {
+ format!("Some({})", and_then_snippets.span)
+ } else {
+ "None".to_string()
+ };
+
+ span_lint_and_sugg(
+ cx,
+ COLLAPSIBLE_SPAN_LINT_CALLS,
+ expr.span,
+ "this call is collapsible",
+ "collapse into",
+ format!(
+ "span_lint_and_note({}, {}, {}, {}, {}, {})",
+ and_then_snippets.cx,
+ and_then_snippets.lint,
+ and_then_snippets.span,
+ and_then_snippets.msg,
+ note_span,
+ note
+ ),
+ Applicability::MachineApplicable,
+ );
+}
+
+declare_lint_pass!(MatchTypeOnDiagItem => [MATCH_TYPE_ON_DIAGNOSTIC_ITEM]);
+
+impl<'tcx> LateLintPass<'tcx> for MatchTypeOnDiagItem {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
+ if is_lint_allowed(cx, MATCH_TYPE_ON_DIAGNOSTIC_ITEM, expr.hir_id) {
+ return;
+ }
+
+ if_chain! {
+ // Check if this is a call to utils::match_type()
+ if let ExprKind::Call(fn_path, [context, ty, ty_path]) = expr.kind;
+ if is_expr_path_def_path(cx, fn_path, &["clippy_utils", "ty", "match_type"]);
+ // Extract the path to the matched type
+ if let Some(segments) = path_to_matched_type(cx, ty_path);
+ let segments: Vec<&str> = segments.iter().map(Symbol::as_str).collect();
+ if let Some(ty_did) = def_path_res(cx, &segments[..]).opt_def_id();
+ // Check if the matched type is a diagnostic item
+ if let Some(item_name) = cx.tcx.get_diagnostic_name(ty_did);
+ then {
+ // TODO: check paths constants from external crates.
+ let cx_snippet = snippet(cx, context.span, "_");
+ let ty_snippet = snippet(cx, ty.span, "_");
+
+ span_lint_and_sugg(
+ cx,
+ MATCH_TYPE_ON_DIAGNOSTIC_ITEM,
+ expr.span,
+ "usage of `clippy_utils::ty::match_type()` on a type diagnostic item",
+ "try",
+ format!("clippy_utils::ty::is_type_diagnostic_item({}, {}, sym::{})", cx_snippet, ty_snippet, item_name),
+ Applicability::MaybeIncorrect,
+ );
+ }
+ }
+ }
+}
+
+fn path_to_matched_type(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> Option<Vec<Symbol>> {
+ use rustc_hir::ItemKind;
+
+ match &expr.kind {
+ ExprKind::AddrOf(.., expr) => return path_to_matched_type(cx, expr),
+ ExprKind::Path(qpath) => match cx.qpath_res(qpath, expr.hir_id) {
+ Res::Local(hir_id) => {
+ let parent_id = cx.tcx.hir().get_parent_node(hir_id);
+ if let Some(Node::Local(local)) = cx.tcx.hir().find(parent_id) {
+ if let Some(init) = local.init {
+ return path_to_matched_type(cx, init);
+ }
+ }
+ },
+ Res::Def(DefKind::Const | DefKind::Static(..), def_id) => {
+ if let Some(Node::Item(item)) = cx.tcx.hir().get_if_local(def_id) {
+ if let ItemKind::Const(.., body_id) | ItemKind::Static(.., body_id) = item.kind {
+ let body = cx.tcx.hir().body(body_id);
+ return path_to_matched_type(cx, &body.value);
+ }
+ }
+ },
+ _ => {},
+ },
+ ExprKind::Array(exprs) => {
+ let segments: Vec<Symbol> = exprs
+ .iter()
+ .filter_map(|expr| {
+ if let ExprKind::Lit(lit) = &expr.kind {
+ if let LitKind::Str(sym, _) = lit.node {
+ return Some(sym);
+ }
+ }
+
+ None
+ })
+ .collect();
+
+ if segments.len() == exprs.len() {
+ return Some(segments);
+ }
+ },
+ _ => {},
+ }
+
+ None
+}
+
+// This is not a complete resolver for paths. It works on all the paths currently used in the paths
+// module. That's all it does and all it needs to do.
+pub fn check_path(cx: &LateContext<'_>, path: &[&str]) -> bool {
+ if def_path_res(cx, path) != Res::Err {
+ return true;
+ }
+
+ // Some implementations can't be found by `path_to_res`, particularly inherent
+ // implementations of native types. Check lang items.
+ let path_syms: Vec<_> = path.iter().map(|p| Symbol::intern(p)).collect();
+ let lang_items = cx.tcx.lang_items();
+ // This list isn't complete, but good enough for our current list of paths.
+ let incoherent_impls = [
+ SimplifiedTypeGen::FloatSimplifiedType(FloatTy::F32),
+ SimplifiedTypeGen::FloatSimplifiedType(FloatTy::F64),
+ SimplifiedTypeGen::SliceSimplifiedType,
+ SimplifiedTypeGen::StrSimplifiedType,
+ ]
+ .iter()
+ .flat_map(|&ty| cx.tcx.incoherent_impls(ty));
+ for item_def_id in lang_items.items().iter().flatten().chain(incoherent_impls) {
+ let lang_item_path = cx.get_def_path(*item_def_id);
+ if path_syms.starts_with(&lang_item_path) {
+ if let [item] = &path_syms[lang_item_path.len()..] {
+ if matches!(
+ cx.tcx.def_kind(*item_def_id),
+ DefKind::Mod | DefKind::Enum | DefKind::Trait
+ ) {
+ for child in cx.tcx.module_children(*item_def_id) {
+ if child.ident.name == *item {
+ return true;
+ }
+ }
+ } else {
+ for child in cx.tcx.associated_item_def_ids(*item_def_id) {
+ if cx.tcx.item_name(*child) == *item {
+ return true;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ false
+}
+
+declare_lint_pass!(InvalidPaths => [INVALID_PATHS]);
+
+impl<'tcx> LateLintPass<'tcx> for InvalidPaths {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
+ let local_def_id = &cx.tcx.parent_module(item.hir_id());
+ let mod_name = &cx.tcx.item_name(local_def_id.to_def_id());
+ if_chain! {
+ if mod_name.as_str() == "paths";
+ if let hir::ItemKind::Const(ty, body_id) = item.kind;
+ let ty = hir_ty_to_ty(cx.tcx, ty);
+ if let ty::Array(el_ty, _) = &ty.kind();
+ if let ty::Ref(_, el_ty, _) = &el_ty.kind();
+ if el_ty.is_str();
+ let body = cx.tcx.hir().body(body_id);
+ let typeck_results = cx.tcx.typeck_body(body_id);
+ if let Some(Constant::Vec(path)) = constant_simple(cx, typeck_results, &body.value);
+ let path: Vec<&str> = path.iter().map(|x| {
+ if let Constant::Str(s) = x {
+ s.as_str()
+ } else {
+ // We checked the type of the constant above
+ unreachable!()
+ }
+ }).collect();
+ if !check_path(cx, &path[..]);
+ then {
+ span_lint(cx, INVALID_PATHS, item.span, "invalid path");
+ }
+ }
+ }
+}
+
+#[derive(Default)]
+pub struct InterningDefinedSymbol {
+ // Maps the symbol value to the constant DefId.
+ symbol_map: FxHashMap<u32, DefId>,
+}
+
+impl_lint_pass!(InterningDefinedSymbol => [INTERNING_DEFINED_SYMBOL, UNNECESSARY_SYMBOL_STR]);
+
+impl<'tcx> LateLintPass<'tcx> for InterningDefinedSymbol {
+ fn check_crate(&mut self, cx: &LateContext<'_>) {
+ if !self.symbol_map.is_empty() {
+ return;
+ }
+
+ for &module in &[&paths::KW_MODULE, &paths::SYM_MODULE] {
+ if let Some(def_id) = def_path_res(cx, module).opt_def_id() {
+ for item in cx.tcx.module_children(def_id).iter() {
+ if_chain! {
+ if let Res::Def(DefKind::Const, item_def_id) = item.res;
+ let ty = cx.tcx.type_of(item_def_id);
+ if match_type(cx, ty, &paths::SYMBOL);
+ if let Ok(ConstValue::Scalar(value)) = cx.tcx.const_eval_poly(item_def_id);
+ if let Ok(value) = value.to_u32();
+ then {
+ self.symbol_map.insert(value, item_def_id);
+ }
+ }
+ }
+ }
+ }
+ }
+
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Call(func, [arg]) = &expr.kind;
+ if let ty::FnDef(def_id, _) = cx.typeck_results().expr_ty(func).kind();
+ if match_def_path(cx, *def_id, &paths::SYMBOL_INTERN);
+ if let Some(Constant::Str(arg)) = constant_simple(cx, cx.typeck_results(), arg);
+ let value = Symbol::intern(&arg).as_u32();
+ if let Some(&def_id) = self.symbol_map.get(&value);
+ then {
+ span_lint_and_sugg(
+ cx,
+ INTERNING_DEFINED_SYMBOL,
+ is_expn_of(expr.span, "sym").unwrap_or(expr.span),
+ "interning a defined symbol",
+ "try",
+ cx.tcx.def_path_str(def_id),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ if let ExprKind::Binary(op, left, right) = expr.kind {
+ if matches!(op.node, BinOpKind::Eq | BinOpKind::Ne) {
+ let data = [
+ (left, self.symbol_str_expr(left, cx)),
+ (right, self.symbol_str_expr(right, cx)),
+ ];
+ match data {
+ // both operands are a symbol string
+ [(_, Some(left)), (_, Some(right))] => {
+ span_lint_and_sugg(
+ cx,
+ UNNECESSARY_SYMBOL_STR,
+ expr.span,
+ "unnecessary `Symbol` to string conversion",
+ "try",
+ format!(
+ "{} {} {}",
+ left.as_symbol_snippet(cx),
+ op.node.as_str(),
+ right.as_symbol_snippet(cx),
+ ),
+ Applicability::MachineApplicable,
+ );
+ },
+ // one of the operands is a symbol string
+ [(expr, Some(symbol)), _] | [_, (expr, Some(symbol))] => {
+ // creating an owned string for comparison
+ if matches!(symbol, SymbolStrExpr::Expr { is_to_owned: true, .. }) {
+ span_lint_and_sugg(
+ cx,
+ UNNECESSARY_SYMBOL_STR,
+ expr.span,
+ "unnecessary string allocation",
+ "try",
+ format!("{}.as_str()", symbol.as_symbol_snippet(cx)),
+ Applicability::MachineApplicable,
+ );
+ }
+ },
+ // nothing found
+ [(_, None), (_, None)] => {},
+ }
+ }
+ }
+ }
+}
+
+impl InterningDefinedSymbol {
+ fn symbol_str_expr<'tcx>(&self, expr: &'tcx Expr<'tcx>, cx: &LateContext<'tcx>) -> Option<SymbolStrExpr<'tcx>> {
+ static IDENT_STR_PATHS: &[&[&str]] = &[&paths::IDENT_AS_STR, &paths::TO_STRING_METHOD];
+ static SYMBOL_STR_PATHS: &[&[&str]] = &[
+ &paths::SYMBOL_AS_STR,
+ &paths::SYMBOL_TO_IDENT_STRING,
+ &paths::TO_STRING_METHOD,
+ ];
+ let call = if_chain! {
+ if let ExprKind::AddrOf(_, _, e) = expr.kind;
+ if let ExprKind::Unary(UnOp::Deref, e) = e.kind;
+ then { e } else { expr }
+ };
+ if_chain! {
+ // is a method call
+ if let ExprKind::MethodCall(_, [item], _) = call.kind;
+ if let Some(did) = cx.typeck_results().type_dependent_def_id(call.hir_id);
+ let ty = cx.typeck_results().expr_ty(item);
+ // ...on either an Ident or a Symbol
+ if let Some(is_ident) = if match_type(cx, ty, &paths::SYMBOL) {
+ Some(false)
+ } else if match_type(cx, ty, &paths::IDENT) {
+ Some(true)
+ } else {
+ None
+ };
+ // ...which converts it to a string
+ let paths = if is_ident { IDENT_STR_PATHS } else { SYMBOL_STR_PATHS };
+ if let Some(path) = paths.iter().find(|path| match_def_path(cx, did, path));
+ then {
+ let is_to_owned = path.last().unwrap().ends_with("string");
+ return Some(SymbolStrExpr::Expr {
+ item,
+ is_ident,
+ is_to_owned,
+ });
+ }
+ }
+ // is a string constant
+ if let Some(Constant::Str(s)) = constant_simple(cx, cx.typeck_results(), expr) {
+ let value = Symbol::intern(&s).as_u32();
+ // ...which matches a symbol constant
+ if let Some(&def_id) = self.symbol_map.get(&value) {
+ return Some(SymbolStrExpr::Const(def_id));
+ }
+ }
+ None
+ }
+}
+
+enum SymbolStrExpr<'tcx> {
+ /// a string constant with a corresponding symbol constant
+ Const(DefId),
+ /// a "symbol to string" expression like `symbol.as_str()`
+ Expr {
+ /// part that evaluates to `Symbol` or `Ident`
+ item: &'tcx Expr<'tcx>,
+ is_ident: bool,
+ /// whether an owned `String` is created like `to_ident_string()`
+ is_to_owned: bool,
+ },
+}
+
+impl<'tcx> SymbolStrExpr<'tcx> {
+ /// Returns a snippet that evaluates to a `Symbol` and is const if possible
+ fn as_symbol_snippet(&self, cx: &LateContext<'_>) -> Cow<'tcx, str> {
+ match *self {
+ Self::Const(def_id) => cx.tcx.def_path_str(def_id).into(),
+ Self::Expr { item, is_ident, .. } => {
+ let mut snip = snippet(cx, item.span.source_callsite(), "..");
+ if is_ident {
+ // get `Ident.name`
+ snip.to_mut().push_str(".name");
+ }
+ snip
+ },
+ }
+ }
+}
+
+declare_lint_pass!(IfChainStyle => [IF_CHAIN_STYLE]);
+
+impl<'tcx> LateLintPass<'tcx> for IfChainStyle {
+ fn check_block(&mut self, cx: &LateContext<'tcx>, block: &'tcx hir::Block<'_>) {
+ let (local, after, if_chain_span) = if_chain! {
+ if let [Stmt { kind: StmtKind::Local(local), .. }, after @ ..] = block.stmts;
+ if let Some(if_chain_span) = is_expn_of(block.span, "if_chain");
+ then { (local, after, if_chain_span) } else { return }
+ };
+ if is_first_if_chain_expr(cx, block.hir_id, if_chain_span) {
+ span_lint(
+ cx,
+ IF_CHAIN_STYLE,
+ if_chain_local_span(cx, local, if_chain_span),
+ "`let` expression should be above the `if_chain!`",
+ );
+ } else if local.span.ctxt() == block.span.ctxt() && is_if_chain_then(after, block.expr, if_chain_span) {
+ span_lint(
+ cx,
+ IF_CHAIN_STYLE,
+ if_chain_local_span(cx, local, if_chain_span),
+ "`let` expression should be inside `then { .. }`",
+ );
+ }
+ }
+
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
+ let (cond, then, els) = if let Some(higher::IfOrIfLet { cond, r#else, then }) = higher::IfOrIfLet::hir(expr) {
+ (cond, then, r#else.is_some())
+ } else {
+ return;
+ };
+ let then_block = match then.kind {
+ ExprKind::Block(block, _) => block,
+ _ => return,
+ };
+ let if_chain_span = is_expn_of(expr.span, "if_chain");
+ if !els {
+ check_nested_if_chains(cx, expr, then_block, if_chain_span);
+ }
+ let if_chain_span = match if_chain_span {
+ None => return,
+ Some(span) => span,
+ };
+ // check for `if a && b;`
+ if_chain! {
+ if let ExprKind::Binary(op, _, _) = cond.kind;
+ if op.node == BinOpKind::And;
+ if cx.sess().source_map().is_multiline(cond.span);
+ then {
+ span_lint(cx, IF_CHAIN_STYLE, cond.span, "`if a && b;` should be `if a; if b;`");
+ }
+ }
+ if is_first_if_chain_expr(cx, expr.hir_id, if_chain_span)
+ && is_if_chain_then(then_block.stmts, then_block.expr, if_chain_span)
+ {
+ span_lint(cx, IF_CHAIN_STYLE, expr.span, "`if_chain!` only has one `if`");
+ }
+ }
+}
+
+fn check_nested_if_chains(
+ cx: &LateContext<'_>,
+ if_expr: &Expr<'_>,
+ then_block: &Block<'_>,
+ if_chain_span: Option<Span>,
+) {
+ #[rustfmt::skip]
+ let (head, tail) = match *then_block {
+ Block { stmts, expr: Some(tail), .. } => (stmts, tail),
+ Block {
+ stmts: &[
+ ref head @ ..,
+ Stmt { kind: StmtKind::Expr(tail) | StmtKind::Semi(tail), .. }
+ ],
+ ..
+ } => (head, tail),
+ _ => return,
+ };
+ if_chain! {
+ if let Some(higher::IfOrIfLet { r#else: None, .. }) = higher::IfOrIfLet::hir(tail);
+ let sm = cx.sess().source_map();
+ if head
+ .iter()
+ .all(|stmt| matches!(stmt.kind, StmtKind::Local(..)) && !sm.is_multiline(stmt.span));
+ if if_chain_span.is_some() || !is_else_clause(cx.tcx, if_expr);
+ then {} else { return }
+ }
+ let (span, msg) = match (if_chain_span, is_expn_of(tail.span, "if_chain")) {
+ (None, Some(_)) => (if_expr.span, "this `if` can be part of the inner `if_chain!`"),
+ (Some(_), None) => (tail.span, "this `if` can be part of the outer `if_chain!`"),
+ (Some(a), Some(b)) if a != b => (b, "this `if_chain!` can be merged with the outer `if_chain!`"),
+ _ => return,
+ };
+ span_lint_and_then(cx, IF_CHAIN_STYLE, span, msg, |diag| {
+ let (span, msg) = match head {
+ [] => return,
+ [stmt] => (stmt.span, "this `let` statement can also be in the `if_chain!`"),
+ [a, .., b] => (
+ a.span.to(b.span),
+ "these `let` statements can also be in the `if_chain!`",
+ ),
+ };
+ diag.span_help(span, msg);
+ });
+}
+
+fn is_first_if_chain_expr(cx: &LateContext<'_>, hir_id: HirId, if_chain_span: Span) -> bool {
+ cx.tcx
+ .hir()
+ .parent_iter(hir_id)
+ .find(|(_, node)| {
+ #[rustfmt::skip]
+ !matches!(node, Node::Expr(Expr { kind: ExprKind::Block(..), .. }) | Node::Stmt(_))
+ })
+ .map_or(false, |(id, _)| {
+ is_expn_of(cx.tcx.hir().span(id), "if_chain") != Some(if_chain_span)
+ })
+}
+
+/// Checks a trailing slice of statements and expression of a `Block` to see if they are part
+/// of the `then {..}` portion of an `if_chain!`
+fn is_if_chain_then(stmts: &[Stmt<'_>], expr: Option<&Expr<'_>>, if_chain_span: Span) -> bool {
+ let span = if let [stmt, ..] = stmts {
+ stmt.span
+ } else if let Some(expr) = expr {
+ expr.span
+ } else {
+ // empty `then {}`
+ return true;
+ };
+ is_expn_of(span, "if_chain").map_or(true, |span| span != if_chain_span)
+}
+
+/// Creates a `Span` for `let x = ..;` in an `if_chain!` call.
+fn if_chain_local_span(cx: &LateContext<'_>, local: &Local<'_>, if_chain_span: Span) -> Span {
+ let mut span = local.pat.span;
+ if let Some(init) = local.init {
+ span = span.to(init.span);
+ }
+ span.adjust(if_chain_span.ctxt().outer_expn());
+ let sm = cx.sess().source_map();
+ let span = sm.span_extend_to_prev_str(span, "let", false, true).unwrap_or(span);
+ let span = sm.span_extend_to_next_char(span, ';', false);
+ Span::new(
+ span.lo() - BytePos(3),
+ span.hi() + BytePos(1),
+ span.ctxt(),
+ span.parent(),
+ )
+}
+
+declare_lint_pass!(MsrvAttrImpl => [MISSING_MSRV_ATTR_IMPL]);
+
+impl LateLintPass<'_> for MsrvAttrImpl {
+ fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) {
+ if_chain! {
+ if let hir::ItemKind::Impl(hir::Impl {
+ of_trait: Some(lint_pass_trait_ref),
+ self_ty,
+ items,
+ ..
+ }) = &item.kind;
+ if let Some(lint_pass_trait_def_id) = lint_pass_trait_ref.trait_def_id();
+ let is_late_pass = match_def_path(cx, lint_pass_trait_def_id, &paths::LATE_LINT_PASS);
+ if is_late_pass || match_def_path(cx, lint_pass_trait_def_id, &paths::EARLY_LINT_PASS);
+ let self_ty = hir_ty_to_ty(cx.tcx, self_ty);
+ if let ty::Adt(self_ty_def, _) = self_ty.kind();
+ if self_ty_def.is_struct();
+ if self_ty_def.all_fields().any(|f| {
+ cx.tcx
+ .type_of(f.did)
+ .walk()
+ .filter(|t| matches!(t.unpack(), GenericArgKind::Type(_)))
+ .any(|t| match_type(cx, t.expect_ty(), &paths::RUSTC_VERSION))
+ });
+ if !items.iter().any(|item| item.ident.name == sym!(enter_lint_attrs));
+ then {
+ let context = if is_late_pass { "LateContext" } else { "EarlyContext" };
+ let lint_pass = if is_late_pass { "LateLintPass" } else { "EarlyLintPass" };
+ let span = cx.sess().source_map().span_through_char(item.span, '{');
+ span_lint_and_sugg(
+ cx,
+ MISSING_MSRV_ATTR_IMPL,
+ span,
+ &format!("`extract_msrv_attr!` macro missing from `{lint_pass}` implementation"),
+ &format!("add `extract_msrv_attr!({context})` to the `{lint_pass}` implementation"),
+ format!("{}\n extract_msrv_attr!({context});", snippet(cx, span, "..")),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ }
+}
--- /dev/null
- lints
- .iter_mut()
- .for_each(|x| x.applicability = Some(applicability_info.remove(&x.id).unwrap_or_default()));
+//! This lint is used to collect metadata about clippy lints. This metadata is exported as a json
+//! file and then used to generate the [clippy lint list](https://rust-lang.github.io/rust-clippy/master/index.html)
+//!
+//! This module and therefore the entire lint is guarded by a feature flag called `internal`
+//!
+//! The module transforms all lint names to ascii lowercase to ensure that we don't have mismatches
+//! during any comparison or mapping. (Please take care of this, it's not fun to spend time on such
+//! a simple mistake)
+
++use crate::renamed_lints::RENAMED_LINTS;
+use crate::utils::internal_lints::{extract_clippy_version_value, is_lint_ref_type};
+
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::ty::{match_type, walk_ptrs_ty_depth};
+use clippy_utils::{last_path_segment, match_def_path, match_function_call, match_path, paths};
+use if_chain::if_chain;
+use rustc_ast as ast;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_hir::{
+ self as hir, def::DefKind, intravisit, intravisit::Visitor, ExprKind, Item, ItemKind, Mutability, QPath,
+};
+use rustc_lint::{CheckLintNameResult, LateContext, LateLintPass, LintContext, LintId};
+use rustc_middle::hir::nested_filter;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::symbol::Ident;
+use rustc_span::{sym, Loc, Span, Symbol};
+use serde::{ser::SerializeStruct, Serialize, Serializer};
+use std::collections::BinaryHeap;
+use std::fmt;
++use std::fmt::Write as _;
+use std::fs::{self, OpenOptions};
+use std::io::prelude::*;
+use std::path::Path;
+
+/// This is the output file of the lint collector.
+const OUTPUT_FILE: &str = "../util/gh-pages/lints.json";
+/// These lints are excluded from the export.
+const BLACK_LISTED_LINTS: &[&str] = &["lint_author", "dump_hir", "internal_metadata_collector"];
+/// These groups will be ignored by the lint group matcher. This is useful for collections like
+/// `clippy::all`
+const IGNORED_LINT_GROUPS: [&str; 1] = ["clippy::all"];
+/// Lints within this group will be excluded from the collection. These groups
+/// have to be defined without the `clippy::` prefix.
+const EXCLUDED_LINT_GROUPS: [&str; 1] = ["internal"];
+/// Collected deprecated lint will be assigned to this group in the JSON output
+const DEPRECATED_LINT_GROUP_STR: &str = "deprecated";
+/// This is the lint level for deprecated lints that will be displayed in the lint list
+const DEPRECATED_LINT_LEVEL: &str = "none";
+/// This array holds Clippy's lint groups with their corresponding default lint level. The
+/// lint level for deprecated lints is set in `DEPRECATED_LINT_LEVEL`.
+const DEFAULT_LINT_LEVELS: &[(&str, &str)] = &[
+ ("correctness", "deny"),
+ ("suspicious", "warn"),
+ ("restriction", "allow"),
+ ("style", "warn"),
+ ("pedantic", "allow"),
+ ("complexity", "warn"),
+ ("perf", "warn"),
+ ("cargo", "allow"),
+ ("nursery", "allow"),
+];
+/// This prefix is in front of the lint groups in the lint store. The prefix will be trimmed
+/// to only keep the actual lint group in the output.
+const CLIPPY_LINT_GROUP_PREFIX: &str = "clippy::";
+
+/// This template will be used to format the configuration section in the lint documentation.
+/// The `configurations` parameter will be replaced with one or multiple formatted
+/// `ClippyConfiguration` instances. See `CONFIGURATION_VALUE_TEMPLATE` for further customizations
+macro_rules! CONFIGURATION_SECTION_TEMPLATE {
+ () => {
+ r#"
+### Configuration
+This lint has the following configuration variables:
+
+{configurations}
+"#
+ };
+}
+/// This template will be used to format an individual `ClippyConfiguration` instance in the
+/// lint documentation.
+///
+/// The format function will provide strings for the following parameters: `name`, `ty`, `doc` and
+/// `default`
+macro_rules! CONFIGURATION_VALUE_TEMPLATE {
+ () => {
+ "* `{name}`: `{ty}`: {doc} (defaults to `{default}`)\n"
+ };
+}
+
++macro_rules! RENAMES_SECTION_TEMPLATE {
++ () => {
++ r#"
++### Past names
++
++{names}
++"#
++ };
++}
++macro_rules! RENAME_VALUE_TEMPLATE {
++ () => {
++ "* `{name}`\n"
++ };
++}
++
+const LINT_EMISSION_FUNCTIONS: [&[&str]; 8] = [
+ &["clippy_utils", "diagnostics", "span_lint"],
+ &["clippy_utils", "diagnostics", "span_lint_and_help"],
+ &["clippy_utils", "diagnostics", "span_lint_and_note"],
+ &["clippy_utils", "diagnostics", "span_lint_hir"],
+ &["clippy_utils", "diagnostics", "span_lint_and_sugg"],
+ &["clippy_utils", "diagnostics", "span_lint_and_then"],
+ &["clippy_utils", "diagnostics", "span_lint_hir_and_then"],
+ &["clippy_utils", "diagnostics", "span_lint_and_sugg_for_edges"],
+];
+const SUGGESTION_DIAGNOSTIC_BUILDER_METHODS: [(&str, bool); 9] = [
+ ("span_suggestion", false),
+ ("span_suggestion_short", false),
+ ("span_suggestion_verbose", false),
+ ("span_suggestion_hidden", false),
+ ("tool_only_span_suggestion", false),
+ ("multipart_suggestion", true),
+ ("multipart_suggestions", true),
+ ("tool_only_multipart_suggestion", true),
+ ("span_suggestions", true),
+];
+const SUGGESTION_FUNCTIONS: [&[&str]; 2] = [
+ &["clippy_utils", "diagnostics", "multispan_sugg"],
+ &["clippy_utils", "diagnostics", "multispan_sugg_with_applicability"],
+];
+const DEPRECATED_LINT_TYPE: [&str; 3] = ["clippy_lints", "deprecated_lints", "ClippyDeprecatedLint"];
+
+/// The index of the applicability name of `paths::APPLICABILITY_VALUES`
+const APPLICABILITY_NAME_INDEX: usize = 2;
+/// This applicability will be set for unresolved applicability values.
+const APPLICABILITY_UNRESOLVED_STR: &str = "Unresolved";
+/// The version that will be displayed if none has been defined
+const VERSION_DEFAULT_STR: &str = "Unknown";
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Collects metadata about clippy lints for the website.
+ ///
+ /// This lint will be used to report problems of syntax parsing. You should hopefully never
+ /// see this but never say never I guess ^^
+ ///
+ /// ### Why is this bad?
+ /// This is not a bad thing but definitely a hacky way to do it. See
+ /// issue [#4310](https://github.com/rust-lang/rust-clippy/issues/4310) for a discussion
+ /// about the implementation.
+ ///
+ /// ### Known problems
+ /// Hopefully none. It would be pretty uncool to have a problem here :)
+ ///
+ /// ### Example output
+ /// ```json,ignore
+ /// {
+ /// "id": "internal_metadata_collector",
+ /// "id_span": {
+ /// "path": "clippy_lints/src/utils/internal_lints/metadata_collector.rs",
+ /// "line": 1
+ /// },
+ /// "group": "clippy::internal",
+ /// "docs": " ### What it does\nCollects metadata about clippy lints for the website. [...] "
+ /// }
+ /// ```
+ #[clippy::version = "1.56.0"]
+ pub INTERNAL_METADATA_COLLECTOR,
+ internal_warn,
+ "A busy bee collection metadata about lints"
+}
+
+impl_lint_pass!(MetadataCollector => [INTERNAL_METADATA_COLLECTOR]);
+
+#[allow(clippy::module_name_repetitions)]
+#[derive(Debug, Clone)]
+pub struct MetadataCollector {
+ /// All collected lints
+ ///
+ /// We use a Heap here to have the lints added in alphabetic order in the export
+ lints: BinaryHeap<LintMetadata>,
+ applicability_info: FxHashMap<String, ApplicabilityInfo>,
+ config: Vec<ClippyConfiguration>,
+}
+
+impl MetadataCollector {
+ pub fn new() -> Self {
+ Self {
+ lints: BinaryHeap::<LintMetadata>::default(),
+ applicability_info: FxHashMap::<String, ApplicabilityInfo>::default(),
+ config: collect_configs(),
+ }
+ }
+
+ fn get_lint_configs(&self, lint_name: &str) -> Option<String> {
+ self.config
+ .iter()
+ .filter(|config| config.lints.iter().any(|lint| lint == lint_name))
+ .map(ToString::to_string)
+ .reduce(|acc, x| acc + &x)
+ .map(|configurations| format!(CONFIGURATION_SECTION_TEMPLATE!(), configurations = configurations))
+ }
+}
+
+impl Drop for MetadataCollector {
+ /// You might ask: How hacky is this?
+ /// My answer: YES
+ fn drop(&mut self) {
+ // The metadata collector gets dropped twice, this makes sure that we only write
+ // when the list is full
+ if self.lints.is_empty() {
+ return;
+ }
+
+ let mut applicability_info = std::mem::take(&mut self.applicability_info);
+
+ // Mapping the final data
+ let mut lints = std::mem::take(&mut self.lints).into_sorted_vec();
- let mut docs = String::from(&*lines.next()?.as_str());
++ collect_renames(&mut lints);
++ for x in &mut lints {
++ x.applicability = Some(applicability_info.remove(&x.id).unwrap_or_default());
++ }
+
+ // Outputting
+ if Path::new(OUTPUT_FILE).exists() {
+ fs::remove_file(OUTPUT_FILE).unwrap();
+ }
+ let mut file = OpenOptions::new().write(true).create(true).open(OUTPUT_FILE).unwrap();
+ writeln!(file, "{}", serde_json::to_string_pretty(&lints).unwrap()).unwrap();
+ }
+}
+
+#[derive(Debug, Clone, Serialize, PartialEq, Eq, PartialOrd, Ord)]
+struct LintMetadata {
+ id: String,
+ id_span: SerializableSpan,
+ group: String,
+ level: String,
+ docs: String,
+ version: String,
+ /// This field is only used in the output and will only be
+ /// mapped shortly before the actual output.
+ applicability: Option<ApplicabilityInfo>,
+}
+
+impl LintMetadata {
+ fn new(
+ id: String,
+ id_span: SerializableSpan,
+ group: String,
+ level: &'static str,
+ version: String,
+ docs: String,
+ ) -> Self {
+ Self {
+ id,
+ id_span,
+ group,
+ level: level.to_string(),
+ version,
+ docs,
+ applicability: None,
+ }
+ }
+}
+
+#[derive(Debug, Clone, Serialize, PartialEq, Eq, PartialOrd, Ord)]
+struct SerializableSpan {
+ path: String,
+ line: usize,
+}
+
+impl std::fmt::Display for SerializableSpan {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ write!(f, "{}:{}", self.path.rsplit('/').next().unwrap_or_default(), self.line)
+ }
+}
+
+impl SerializableSpan {
+ fn from_item(cx: &LateContext<'_>, item: &Item<'_>) -> Self {
+ Self::from_span(cx, item.ident.span)
+ }
+
+ fn from_span(cx: &LateContext<'_>, span: Span) -> Self {
+ let loc: Loc = cx.sess().source_map().lookup_char_pos(span.lo());
+
+ Self {
+ path: format!("{}", loc.file.name.prefer_remapped()),
+ line: loc.line,
+ }
+ }
+}
+
+#[derive(Debug, Clone, Default, PartialEq, Eq, PartialOrd, Ord)]
+struct ApplicabilityInfo {
+ /// Indicates if any of the lint emissions uses multiple spans. This is related to
+ /// [rustfix#141](https://github.com/rust-lang/rustfix/issues/141) as such suggestions can
+ /// currently not be applied automatically.
+ is_multi_part_suggestion: bool,
+ applicability: Option<usize>,
+}
+
+impl Serialize for ApplicabilityInfo {
+ fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+ where
+ S: Serializer,
+ {
+ let mut s = serializer.serialize_struct("ApplicabilityInfo", 2)?;
+ s.serialize_field("is_multi_part_suggestion", &self.is_multi_part_suggestion)?;
+ if let Some(index) = self.applicability {
+ s.serialize_field(
+ "applicability",
+ &paths::APPLICABILITY_VALUES[index][APPLICABILITY_NAME_INDEX],
+ )?;
+ } else {
+ s.serialize_field("applicability", APPLICABILITY_UNRESOLVED_STR)?;
+ }
+ s.end()
+ }
+}
+
+// ==================================================================
+// Configuration
+// ==================================================================
+#[derive(Debug, Clone, Default)]
+pub struct ClippyConfiguration {
+ name: String,
+ config_type: &'static str,
+ default: String,
+ lints: Vec<String>,
+ doc: String,
+ #[allow(dead_code)]
+ deprecation_reason: Option<&'static str>,
+}
+
+impl ClippyConfiguration {
+ pub fn new(
+ name: &'static str,
+ config_type: &'static str,
+ default: String,
+ doc_comment: &'static str,
+ deprecation_reason: Option<&'static str>,
+ ) -> Self {
+ let (lints, doc) = parse_config_field_doc(doc_comment)
+ .unwrap_or_else(|| (vec![], "[ERROR] MALFORMED DOC COMMENT".to_string()));
+
+ Self {
+ name: to_kebab(name),
+ lints,
+ doc,
+ config_type,
+ default,
+ deprecation_reason,
+ }
+ }
+}
+
+fn collect_configs() -> Vec<ClippyConfiguration> {
+ crate::utils::conf::metadata::get_configuration_metadata()
+}
+
+/// This parses the field documentation of the config struct.
+///
+/// ```rust, ignore
+/// parse_config_field_doc(cx, "Lint: LINT_NAME_1, LINT_NAME_2. Papa penguin, papa penguin")
+/// ```
+///
+/// Would yield:
+/// ```rust, ignore
+/// Some(["lint_name_1", "lint_name_2"], "Papa penguin, papa penguin")
+/// ```
+fn parse_config_field_doc(doc_comment: &str) -> Option<(Vec<String>, String)> {
+ const DOC_START: &str = " Lint: ";
+ if_chain! {
+ if doc_comment.starts_with(DOC_START);
+ if let Some(split_pos) = doc_comment.find('.');
+ then {
+ let mut doc_comment = doc_comment.to_string();
+ let mut documentation = doc_comment.split_off(split_pos);
+
+ // Extract lints
+ doc_comment.make_ascii_lowercase();
+ let lints: Vec<String> = doc_comment.split_off(DOC_START.len()).split(", ").map(str::to_string).collect();
+
+ // Format documentation correctly
+ // split off leading `.` from lint name list and indent for correct formatting
+ documentation = documentation.trim_start_matches('.').trim().replace("\n ", "\n ");
+
+ Some((lints, documentation))
+ } else {
+ None
+ }
+ }
+}
+
+/// Transforms a given `snake_case_string` to a tasty `kebab-case-string`
+fn to_kebab(config_name: &str) -> String {
+ config_name.replace('_', "-")
+}
+
+impl fmt::Display for ClippyConfiguration {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> fmt::Result {
+ write!(
+ f,
+ CONFIGURATION_VALUE_TEMPLATE!(),
+ name = self.name,
+ ty = self.config_type,
+ doc = self.doc,
+ default = self.default
+ )
+ }
+}
+
+// ==================================================================
+// Lint pass
+// ==================================================================
+impl<'hir> LateLintPass<'hir> for MetadataCollector {
+ /// Collecting lint declarations like:
+ /// ```rust, ignore
+ /// declare_clippy_lint! {
+ /// /// ### What it does
+ /// /// Something IDK.
+ /// pub SOME_LINT,
+ /// internal,
+ /// "Who am I?"
+ /// }
+ /// ```
+ fn check_item(&mut self, cx: &LateContext<'hir>, item: &'hir Item<'_>) {
+ if let ItemKind::Static(ty, Mutability::Not, _) = item.kind {
+ // Normal lint
+ if_chain! {
+ // item validation
+ if is_lint_ref_type(cx, ty);
+ // blacklist check
+ let lint_name = sym_to_string(item.ident.name).to_ascii_lowercase();
+ if !BLACK_LISTED_LINTS.contains(&lint_name.as_str());
+ // metadata extraction
+ if let Some((group, level)) = get_lint_group_and_level_or_lint(cx, &lint_name, item);
+ if let Some(mut docs) = extract_attr_docs_or_lint(cx, item);
+ then {
+ if let Some(configuration_section) = self.get_lint_configs(&lint_name) {
+ docs.push_str(&configuration_section);
+ }
+ let version = get_lint_version(cx, item);
+
+ self.lints.push(LintMetadata::new(
+ lint_name,
+ SerializableSpan::from_item(cx, item),
+ group,
+ level,
+ version,
+ docs,
+ ));
+ }
+ }
+
+ if_chain! {
+ if is_deprecated_lint(cx, ty);
+ // blacklist check
+ let lint_name = sym_to_string(item.ident.name).to_ascii_lowercase();
+ if !BLACK_LISTED_LINTS.contains(&lint_name.as_str());
+ // Metadata the little we can get from a deprecated lint
+ if let Some(docs) = extract_attr_docs_or_lint(cx, item);
+ then {
+ let version = get_lint_version(cx, item);
+
+ self.lints.push(LintMetadata::new(
+ lint_name,
+ SerializableSpan::from_item(cx, item),
+ DEPRECATED_LINT_GROUP_STR.to_string(),
+ DEPRECATED_LINT_LEVEL,
+ version,
+ docs,
+ ));
+ }
+ }
+ }
+ }
+
+ /// Collecting constant applicability from the actual lint emissions
+ ///
+ /// Example:
+ /// ```rust, ignore
+ /// span_lint_and_sugg(
+ /// cx,
+ /// SOME_LINT,
+ /// item.span,
+ /// "Le lint message",
+ /// "Here comes help:",
+ /// "#![allow(clippy::all)]",
+ /// Applicability::MachineApplicable, // <-- Extracts this constant value
+ /// );
+ /// ```
+ fn check_expr(&mut self, cx: &LateContext<'hir>, expr: &'hir hir::Expr<'_>) {
+ if let Some(args) = match_lint_emission(cx, expr) {
+ let emission_info = extract_emission_info(cx, args);
+ if emission_info.is_empty() {
+ // See:
+ // - src/misc.rs:734:9
+ // - src/methods/mod.rs:3545:13
+ // - src/methods/mod.rs:3496:13
+ // We are basically unable to resolve the lint name itself.
+ return;
+ }
+
+ for (lint_name, applicability, is_multi_part) in emission_info {
+ let app_info = self.applicability_info.entry(lint_name).or_default();
+ app_info.applicability = applicability;
+ app_info.is_multi_part_suggestion = is_multi_part;
+ }
+ }
+ }
+}
+
+// ==================================================================
+// Lint definition extraction
+// ==================================================================
+fn sym_to_string(sym: Symbol) -> String {
+ sym.as_str().to_string()
+}
+
+fn extract_attr_docs_or_lint(cx: &LateContext<'_>, item: &Item<'_>) -> Option<String> {
+ extract_attr_docs(cx, item).or_else(|| {
+ lint_collection_error_item(cx, item, "could not collect the lint documentation");
+ None
+ })
+}
+
+/// This function collects all documentation that has been added to an item using
+/// `#[doc = r""]` attributes. Several attributes are aggravated using line breaks
+///
+/// ```ignore
+/// #[doc = r"Hello world!"]
+/// #[doc = r"=^.^="]
+/// struct SomeItem {}
+/// ```
+///
+/// Would result in `Hello world!\n=^.^=\n`
+///
+/// ---
+///
+/// This function may modify the doc comment to ensure that the string can be displayed using a
+/// markdown viewer in Clippy's lint list. The following modifications could be applied:
+/// * Removal of leading space after a new line. (Important to display tables)
+/// * Ensures that code blocks only contain language information
+fn extract_attr_docs(cx: &LateContext<'_>, item: &Item<'_>) -> Option<String> {
+ let attrs = cx.tcx.hir().attrs(item.hir_id());
+ let mut lines = attrs.iter().filter_map(ast::Attribute::doc_str);
- let line = &*line;
++ let mut docs = String::from(lines.next()?.as_str());
+ let mut in_code_block = false;
+ let mut is_code_block_rust = false;
+ for line in lines {
+ let line = line.as_str();
+
+ // Rustdoc hides code lines starting with `# ` and this removes them from Clippy's lint list :)
+ if is_code_block_rust && line.trim_start().starts_with("# ") {
+ continue;
+ }
+
+ // The line should be represented in the lint list, even if it's just an empty line
+ docs.push('\n');
+ if let Some(info) = line.trim_start().strip_prefix("```") {
+ in_code_block = !in_code_block;
+ is_code_block_rust = false;
+ if in_code_block {
+ let lang = info
+ .trim()
+ .split(',')
+ // remove rustdoc directives
+ .find(|&s| !matches!(s, "" | "ignore" | "no_run" | "should_panic"))
+ // if no language is present, fill in "rust"
+ .unwrap_or("rust");
+ docs.push_str("```");
+ docs.push_str(lang);
+
+ is_code_block_rust = lang == "rust";
+ continue;
+ }
+ }
+ // This removes the leading space that the macro translation introduces
+ if let Some(stripped_doc) = line.strip_prefix(' ') {
+ docs.push_str(stripped_doc);
+ } else if !line.is_empty() {
+ docs.push_str(line);
+ }
+ }
+ Some(docs)
+}
+
+fn get_lint_version(cx: &LateContext<'_>, item: &Item<'_>) -> String {
+ extract_clippy_version_value(cx, item).map_or_else(
+ || VERSION_DEFAULT_STR.to_string(),
+ |version| version.as_str().to_string(),
+ )
+}
+
+fn get_lint_group_and_level_or_lint(
+ cx: &LateContext<'_>,
+ lint_name: &str,
+ item: &Item<'_>,
+) -> Option<(String, &'static str)> {
+ let result = cx.lint_store.check_lint_name(
+ lint_name,
+ Some(sym::clippy),
+ &[Ident::with_dummy_span(sym::clippy)].into_iter().collect(),
+ );
+ if let CheckLintNameResult::Tool(Ok(lint_lst)) = result {
+ if let Some(group) = get_lint_group(cx, lint_lst[0]) {
+ if EXCLUDED_LINT_GROUPS.contains(&group.as_str()) {
+ return None;
+ }
+
+ if let Some(level) = get_lint_level_from_group(&group) {
+ Some((group, level))
+ } else {
+ lint_collection_error_item(
+ cx,
+ item,
+ &format!("Unable to determine lint level for found group `{}`", group),
+ );
+ None
+ }
+ } else {
+ lint_collection_error_item(cx, item, "Unable to determine lint group");
+ None
+ }
+ } else {
+ lint_collection_error_item(cx, item, "Unable to find lint in lint_store");
+ None
+ }
+}
+
+fn get_lint_group(cx: &LateContext<'_>, lint_id: LintId) -> Option<String> {
+ for (group_name, lints, _) in cx.lint_store.get_lint_groups() {
+ if IGNORED_LINT_GROUPS.contains(&group_name) {
+ continue;
+ }
+
+ if lints.iter().any(|group_lint| *group_lint == lint_id) {
+ let group = group_name.strip_prefix(CLIPPY_LINT_GROUP_PREFIX).unwrap_or(group_name);
+ return Some((*group).to_string());
+ }
+ }
+
+ None
+}
+
+fn get_lint_level_from_group(lint_group: &str) -> Option<&'static str> {
+ DEFAULT_LINT_LEVELS
+ .iter()
+ .find_map(|(group_name, group_level)| (*group_name == lint_group).then(|| *group_level))
+}
+
+fn is_deprecated_lint(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> bool {
+ if let hir::TyKind::Path(ref path) = ty.kind {
+ if let hir::def::Res::Def(DefKind::Struct, def_id) = cx.qpath_res(path, ty.hir_id) {
+ return match_def_path(cx, def_id, &DEPRECATED_LINT_TYPE);
+ }
+ }
+
+ false
+}
+
++fn collect_renames(lints: &mut Vec<LintMetadata>) {
++ for lint in lints {
++ let mut collected = String::new();
++ let mut names = vec![lint.id.clone()];
++
++ loop {
++ if let Some(lint_name) = names.pop() {
++ for (k, v) in RENAMED_LINTS {
++ if_chain! {
++ if let Some(name) = v.strip_prefix(CLIPPY_LINT_GROUP_PREFIX);
++ if name == lint_name;
++ if let Some(past_name) = k.strip_prefix(CLIPPY_LINT_GROUP_PREFIX);
++ then {
++ write!(collected, RENAME_VALUE_TEMPLATE!(), name = past_name).unwrap();
++ names.push(past_name.to_string());
++ }
++ }
++ }
++
++ continue;
++ }
++
++ break;
++ }
++
++ if !collected.is_empty() {
++ write!(&mut lint.docs, RENAMES_SECTION_TEMPLATE!(), names = collected).unwrap();
++ }
++ }
++}
++
+// ==================================================================
+// Lint emission
+// ==================================================================
+fn lint_collection_error_item(cx: &LateContext<'_>, item: &Item<'_>, message: &str) {
+ span_lint(
+ cx,
+ INTERNAL_METADATA_COLLECTOR,
+ item.ident.span,
+ &format!("metadata collection error for `{}`: {}", item.ident.name, message),
+ );
+}
+
+// ==================================================================
+// Applicability
+// ==================================================================
+/// This function checks if a given expression is equal to a simple lint emission function call.
+/// It will return the function arguments if the emission matched any function.
+fn match_lint_emission<'hir>(cx: &LateContext<'hir>, expr: &'hir hir::Expr<'_>) -> Option<&'hir [hir::Expr<'hir>]> {
+ LINT_EMISSION_FUNCTIONS
+ .iter()
+ .find_map(|emission_fn| match_function_call(cx, expr, emission_fn))
+}
+
+fn take_higher_applicability(a: Option<usize>, b: Option<usize>) -> Option<usize> {
+ a.map_or(b, |a| a.max(b.unwrap_or_default()).into())
+}
+
+fn extract_emission_info<'hir>(
+ cx: &LateContext<'hir>,
+ args: &'hir [hir::Expr<'hir>],
+) -> Vec<(String, Option<usize>, bool)> {
+ let mut lints = Vec::new();
+ let mut applicability = None;
+ let mut multi_part = false;
+
+ for arg in args {
+ let (arg_ty, _) = walk_ptrs_ty_depth(cx.typeck_results().expr_ty(arg));
+
+ if match_type(cx, arg_ty, &paths::LINT) {
+ // If we found the lint arg, extract the lint name
+ let mut resolved_lints = resolve_lints(cx, arg);
+ lints.append(&mut resolved_lints);
+ } else if match_type(cx, arg_ty, &paths::APPLICABILITY) {
+ applicability = resolve_applicability(cx, arg);
+ } else if arg_ty.is_closure() {
+ multi_part |= check_is_multi_part(cx, arg);
+ applicability = applicability.or_else(|| resolve_applicability(cx, arg));
+ }
+ }
+
+ lints
+ .into_iter()
+ .map(|lint_name| (lint_name, applicability, multi_part))
+ .collect()
+}
+
+/// Resolves the possible lints that this expression could reference
+fn resolve_lints<'hir>(cx: &LateContext<'hir>, expr: &'hir hir::Expr<'hir>) -> Vec<String> {
+ let mut resolver = LintResolver::new(cx);
+ resolver.visit_expr(expr);
+ resolver.lints
+}
+
+/// This function tries to resolve the linked applicability to the given expression.
+fn resolve_applicability<'hir>(cx: &LateContext<'hir>, expr: &'hir hir::Expr<'hir>) -> Option<usize> {
+ let mut resolver = ApplicabilityResolver::new(cx);
+ resolver.visit_expr(expr);
+ resolver.complete()
+}
+
+fn check_is_multi_part<'hir>(cx: &LateContext<'hir>, closure_expr: &'hir hir::Expr<'hir>) -> bool {
+ if let ExprKind::Closure(_, _, body_id, _, _) = closure_expr.kind {
+ let mut scanner = IsMultiSpanScanner::new(cx);
+ intravisit::walk_body(&mut scanner, cx.tcx.hir().body(body_id));
+ return scanner.is_multi_part();
+ } else if let Some(local) = get_parent_local(cx, closure_expr) {
+ if let Some(local_init) = local.init {
+ return check_is_multi_part(cx, local_init);
+ }
+ }
+
+ false
+}
+
+struct LintResolver<'a, 'hir> {
+ cx: &'a LateContext<'hir>,
+ lints: Vec<String>,
+}
+
+impl<'a, 'hir> LintResolver<'a, 'hir> {
+ fn new(cx: &'a LateContext<'hir>) -> Self {
+ Self {
+ cx,
+ lints: Vec::<String>::default(),
+ }
+ }
+}
+
+impl<'a, 'hir> intravisit::Visitor<'hir> for LintResolver<'a, 'hir> {
+ type NestedFilter = nested_filter::All;
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+
+ fn visit_expr(&mut self, expr: &'hir hir::Expr<'hir>) {
+ if_chain! {
+ if let ExprKind::Path(qpath) = &expr.kind;
+ if let QPath::Resolved(_, path) = qpath;
+
+ let (expr_ty, _) = walk_ptrs_ty_depth(self.cx.typeck_results().expr_ty(expr));
+ if match_type(self.cx, expr_ty, &paths::LINT);
+ then {
+ if let hir::def::Res::Def(DefKind::Static(..), _) = path.res {
+ let lint_name = last_path_segment(qpath).ident.name;
+ self.lints.push(sym_to_string(lint_name).to_ascii_lowercase());
+ } else if let Some(local) = get_parent_local(self.cx, expr) {
+ if let Some(local_init) = local.init {
+ intravisit::walk_expr(self, local_init);
+ }
+ }
+ }
+ }
+
+ intravisit::walk_expr(self, expr);
+ }
+}
+
+/// This visitor finds the highest applicability value in the visited expressions
+struct ApplicabilityResolver<'a, 'hir> {
+ cx: &'a LateContext<'hir>,
+ /// This is the index of hightest `Applicability` for `paths::APPLICABILITY_VALUES`
+ applicability_index: Option<usize>,
+}
+
+impl<'a, 'hir> ApplicabilityResolver<'a, 'hir> {
+ fn new(cx: &'a LateContext<'hir>) -> Self {
+ Self {
+ cx,
+ applicability_index: None,
+ }
+ }
+
+ fn add_new_index(&mut self, new_index: usize) {
+ self.applicability_index = take_higher_applicability(self.applicability_index, Some(new_index));
+ }
+
+ fn complete(self) -> Option<usize> {
+ self.applicability_index
+ }
+}
+
+impl<'a, 'hir> intravisit::Visitor<'hir> for ApplicabilityResolver<'a, 'hir> {
+ type NestedFilter = nested_filter::All;
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+
+ fn visit_path(&mut self, path: &'hir hir::Path<'hir>, _id: hir::HirId) {
+ for (index, enum_value) in paths::APPLICABILITY_VALUES.iter().enumerate() {
+ if match_path(path, enum_value) {
+ self.add_new_index(index);
+ return;
+ }
+ }
+ }
+
+ fn visit_expr(&mut self, expr: &'hir hir::Expr<'hir>) {
+ let (expr_ty, _) = walk_ptrs_ty_depth(self.cx.typeck_results().expr_ty(expr));
+
+ if_chain! {
+ if match_type(self.cx, expr_ty, &paths::APPLICABILITY);
+ if let Some(local) = get_parent_local(self.cx, expr);
+ if let Some(local_init) = local.init;
+ then {
+ intravisit::walk_expr(self, local_init);
+ }
+ };
+
+ intravisit::walk_expr(self, expr);
+ }
+}
+
+/// This returns the parent local node if the expression is a reference one
+fn get_parent_local<'hir>(cx: &LateContext<'hir>, expr: &'hir hir::Expr<'hir>) -> Option<&'hir hir::Local<'hir>> {
+ if let ExprKind::Path(QPath::Resolved(_, path)) = expr.kind {
+ if let hir::def::Res::Local(local_hir) = path.res {
+ return get_parent_local_hir_id(cx, local_hir);
+ }
+ }
+
+ None
+}
+
+fn get_parent_local_hir_id<'hir>(cx: &LateContext<'hir>, hir_id: hir::HirId) -> Option<&'hir hir::Local<'hir>> {
+ let map = cx.tcx.hir();
+
+ match map.find(map.get_parent_node(hir_id)) {
+ Some(hir::Node::Local(local)) => Some(local),
+ Some(hir::Node::Pat(pattern)) => get_parent_local_hir_id(cx, pattern.hir_id),
+ _ => None,
+ }
+}
+
+/// This visitor finds the highest applicability value in the visited expressions
+struct IsMultiSpanScanner<'a, 'hir> {
+ cx: &'a LateContext<'hir>,
+ suggestion_count: usize,
+}
+
+impl<'a, 'hir> IsMultiSpanScanner<'a, 'hir> {
+ fn new(cx: &'a LateContext<'hir>) -> Self {
+ Self {
+ cx,
+ suggestion_count: 0,
+ }
+ }
+
+ /// Add a new single expression suggestion to the counter
+ fn add_single_span_suggestion(&mut self) {
+ self.suggestion_count += 1;
+ }
+
+ /// Signals that a suggestion with possible multiple spans was found
+ fn add_multi_part_suggestion(&mut self) {
+ self.suggestion_count += 2;
+ }
+
+ /// Checks if the suggestions include multiple spans
+ fn is_multi_part(&self) -> bool {
+ self.suggestion_count > 1
+ }
+}
+
+impl<'a, 'hir> intravisit::Visitor<'hir> for IsMultiSpanScanner<'a, 'hir> {
+ type NestedFilter = nested_filter::All;
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+
+ fn visit_expr(&mut self, expr: &'hir hir::Expr<'hir>) {
+ // Early return if the lint is already multi span
+ if self.is_multi_part() {
+ return;
+ }
+
+ match &expr.kind {
+ ExprKind::Call(fn_expr, _args) => {
+ let found_function = SUGGESTION_FUNCTIONS
+ .iter()
+ .any(|func_path| match_function_call(self.cx, fn_expr, func_path).is_some());
+ if found_function {
+ // These functions are all multi part suggestions
+ self.add_single_span_suggestion();
+ }
+ },
+ ExprKind::MethodCall(path, arg, _arg_span) => {
+ let (self_ty, _) = walk_ptrs_ty_depth(self.cx.typeck_results().expr_ty(&arg[0]));
+ if match_type(self.cx, self_ty, &paths::DIAGNOSTIC_BUILDER) {
+ let called_method = path.ident.name.as_str().to_string();
+ for (method_name, is_multi_part) in &SUGGESTION_DIAGNOSTIC_BUILDER_METHODS {
+ if *method_name == called_method {
+ if *is_multi_part {
+ self.add_multi_part_suggestion();
+ } else {
+ self.add_single_span_suggestion();
+ }
+ break;
+ }
+ }
+ }
+ },
+ _ => {},
+ }
+
+ intravisit::walk_expr(self, expr);
+ }
+}
--- /dev/null
- self.expr(&*then)
+#![allow(clippy::float_cmp)]
+
+use crate::{clip, is_direct_expn_of, sext, unsext};
+use if_chain::if_chain;
+use rustc_ast::ast::{self, LitFloatType, LitKind};
+use rustc_data_structures::sync::Lrc;
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::{BinOp, BinOpKind, Block, Expr, ExprKind, HirId, Item, ItemKind, Node, QPath, UnOp};
+use rustc_lint::LateContext;
+use rustc_middle::mir::interpret::Scalar;
+use rustc_middle::ty::subst::{Subst, SubstsRef};
+use rustc_middle::ty::{self, EarlyBinder, FloatTy, ScalarInt, Ty, TyCtxt};
+use rustc_middle::{bug, span_bug};
+use rustc_span::symbol::Symbol;
+use std::cmp::Ordering::{self, Equal};
+use std::hash::{Hash, Hasher};
+use std::iter;
+
+/// A `LitKind`-like enum to fold constant `Expr`s into.
+#[derive(Debug, Clone)]
+pub enum Constant {
+ /// A `String` (e.g., "abc").
+ Str(String),
+ /// A binary string (e.g., `b"abc"`).
+ Binary(Lrc<[u8]>),
+ /// A single `char` (e.g., `'a'`).
+ Char(char),
+ /// An integer's bit representation.
+ Int(u128),
+ /// An `f32`.
+ F32(f32),
+ /// An `f64`.
+ F64(f64),
+ /// `true` or `false`.
+ Bool(bool),
+ /// An array of constants.
+ Vec(Vec<Constant>),
+ /// Also an array, but with only one constant, repeated N times.
+ Repeat(Box<Constant>, u64),
+ /// A tuple of constants.
+ Tuple(Vec<Constant>),
+ /// A raw pointer.
+ RawPtr(u128),
+ /// A reference
+ Ref(Box<Constant>),
+ /// A literal with syntax error.
+ Err(Symbol),
+}
+
+impl PartialEq for Constant {
+ fn eq(&self, other: &Self) -> bool {
+ match (self, other) {
+ (&Self::Str(ref ls), &Self::Str(ref rs)) => ls == rs,
+ (&Self::Binary(ref l), &Self::Binary(ref r)) => l == r,
+ (&Self::Char(l), &Self::Char(r)) => l == r,
+ (&Self::Int(l), &Self::Int(r)) => l == r,
+ (&Self::F64(l), &Self::F64(r)) => {
+ // We want `Fw32 == FwAny` and `FwAny == Fw64`, and by transitivity we must have
+ // `Fw32 == Fw64`, so don’t compare them.
+ // `to_bits` is required to catch non-matching 0.0, -0.0, and NaNs.
+ l.to_bits() == r.to_bits()
+ },
+ (&Self::F32(l), &Self::F32(r)) => {
+ // We want `Fw32 == FwAny` and `FwAny == Fw64`, and by transitivity we must have
+ // `Fw32 == Fw64`, so don’t compare them.
+ // `to_bits` is required to catch non-matching 0.0, -0.0, and NaNs.
+ f64::from(l).to_bits() == f64::from(r).to_bits()
+ },
+ (&Self::Bool(l), &Self::Bool(r)) => l == r,
+ (&Self::Vec(ref l), &Self::Vec(ref r)) | (&Self::Tuple(ref l), &Self::Tuple(ref r)) => l == r,
+ (&Self::Repeat(ref lv, ref ls), &Self::Repeat(ref rv, ref rs)) => ls == rs && lv == rv,
+ (&Self::Ref(ref lb), &Self::Ref(ref rb)) => *lb == *rb,
+ // TODO: are there inter-type equalities?
+ _ => false,
+ }
+ }
+}
+
+impl Hash for Constant {
+ fn hash<H>(&self, state: &mut H)
+ where
+ H: Hasher,
+ {
+ std::mem::discriminant(self).hash(state);
+ match *self {
+ Self::Str(ref s) => {
+ s.hash(state);
+ },
+ Self::Binary(ref b) => {
+ b.hash(state);
+ },
+ Self::Char(c) => {
+ c.hash(state);
+ },
+ Self::Int(i) => {
+ i.hash(state);
+ },
+ Self::F32(f) => {
+ f64::from(f).to_bits().hash(state);
+ },
+ Self::F64(f) => {
+ f.to_bits().hash(state);
+ },
+ Self::Bool(b) => {
+ b.hash(state);
+ },
+ Self::Vec(ref v) | Self::Tuple(ref v) => {
+ v.hash(state);
+ },
+ Self::Repeat(ref c, l) => {
+ c.hash(state);
+ l.hash(state);
+ },
+ Self::RawPtr(u) => {
+ u.hash(state);
+ },
+ Self::Ref(ref r) => {
+ r.hash(state);
+ },
+ Self::Err(ref s) => {
+ s.hash(state);
+ },
+ }
+ }
+}
+
+impl Constant {
+ pub fn partial_cmp(tcx: TyCtxt<'_>, cmp_type: Ty<'_>, left: &Self, right: &Self) -> Option<Ordering> {
+ match (left, right) {
+ (&Self::Str(ref ls), &Self::Str(ref rs)) => Some(ls.cmp(rs)),
+ (&Self::Char(ref l), &Self::Char(ref r)) => Some(l.cmp(r)),
+ (&Self::Int(l), &Self::Int(r)) => match *cmp_type.kind() {
+ ty::Int(int_ty) => Some(sext(tcx, l, int_ty).cmp(&sext(tcx, r, int_ty))),
+ ty::Uint(_) => Some(l.cmp(&r)),
+ _ => bug!("Not an int type"),
+ },
+ (&Self::F64(l), &Self::F64(r)) => l.partial_cmp(&r),
+ (&Self::F32(l), &Self::F32(r)) => l.partial_cmp(&r),
+ (&Self::Bool(ref l), &Self::Bool(ref r)) => Some(l.cmp(r)),
+ (&Self::Tuple(ref l), &Self::Tuple(ref r)) | (&Self::Vec(ref l), &Self::Vec(ref r)) => iter::zip(l, r)
+ .map(|(li, ri)| Self::partial_cmp(tcx, cmp_type, li, ri))
+ .find(|r| r.map_or(true, |o| o != Ordering::Equal))
+ .unwrap_or_else(|| Some(l.len().cmp(&r.len()))),
+ (&Self::Repeat(ref lv, ref ls), &Self::Repeat(ref rv, ref rs)) => {
+ match Self::partial_cmp(tcx, cmp_type, lv, rv) {
+ Some(Equal) => Some(ls.cmp(rs)),
+ x => x,
+ }
+ },
+ (&Self::Ref(ref lb), &Self::Ref(ref rb)) => Self::partial_cmp(tcx, cmp_type, lb, rb),
+ // TODO: are there any useful inter-type orderings?
+ _ => None,
+ }
+ }
+
+ /// Returns the integer value or `None` if `self` or `val_type` is not integer type.
+ pub fn int_value(&self, cx: &LateContext<'_>, val_type: Ty<'_>) -> Option<FullInt> {
+ if let Constant::Int(const_int) = *self {
+ match *val_type.kind() {
+ ty::Int(ity) => Some(FullInt::S(sext(cx.tcx, const_int, ity))),
+ ty::Uint(_) => Some(FullInt::U(const_int)),
+ _ => None,
+ }
+ } else {
+ None
+ }
+ }
+
+ #[must_use]
+ pub fn peel_refs(mut self) -> Self {
+ while let Constant::Ref(r) = self {
+ self = *r;
+ }
+ self
+ }
+}
+
+/// Parses a `LitKind` to a `Constant`.
+pub fn lit_to_mir_constant(lit: &LitKind, ty: Option<Ty<'_>>) -> Constant {
+ match *lit {
+ LitKind::Str(ref is, _) => Constant::Str(is.to_string()),
+ LitKind::Byte(b) => Constant::Int(u128::from(b)),
+ LitKind::ByteStr(ref s) => Constant::Binary(Lrc::clone(s)),
+ LitKind::Char(c) => Constant::Char(c),
+ LitKind::Int(n, _) => Constant::Int(n),
+ LitKind::Float(ref is, LitFloatType::Suffixed(fty)) => match fty {
+ ast::FloatTy::F32 => Constant::F32(is.as_str().parse().unwrap()),
+ ast::FloatTy::F64 => Constant::F64(is.as_str().parse().unwrap()),
+ },
+ LitKind::Float(ref is, LitFloatType::Unsuffixed) => match ty.expect("type of float is known").kind() {
+ ty::Float(FloatTy::F32) => Constant::F32(is.as_str().parse().unwrap()),
+ ty::Float(FloatTy::F64) => Constant::F64(is.as_str().parse().unwrap()),
+ _ => bug!(),
+ },
+ LitKind::Bool(b) => Constant::Bool(b),
+ LitKind::Err(s) => Constant::Err(s),
+ }
+}
+
+pub fn constant<'tcx>(
+ lcx: &LateContext<'tcx>,
+ typeck_results: &ty::TypeckResults<'tcx>,
+ e: &Expr<'_>,
+) -> Option<(Constant, bool)> {
+ let mut cx = ConstEvalLateContext {
+ lcx,
+ typeck_results,
+ param_env: lcx.param_env,
+ needed_resolution: false,
+ substs: lcx.tcx.intern_substs(&[]),
+ };
+ cx.expr(e).map(|cst| (cst, cx.needed_resolution))
+}
+
+pub fn constant_simple<'tcx>(
+ lcx: &LateContext<'tcx>,
+ typeck_results: &ty::TypeckResults<'tcx>,
+ e: &Expr<'_>,
+) -> Option<Constant> {
+ constant(lcx, typeck_results, e).and_then(|(cst, res)| if res { None } else { Some(cst) })
+}
+
+pub fn constant_full_int<'tcx>(
+ lcx: &LateContext<'tcx>,
+ typeck_results: &ty::TypeckResults<'tcx>,
+ e: &Expr<'_>,
+) -> Option<FullInt> {
+ constant_simple(lcx, typeck_results, e)?.int_value(lcx, typeck_results.expr_ty(e))
+}
+
+#[derive(Copy, Clone, Debug, Eq)]
+pub enum FullInt {
+ S(i128),
+ U(u128),
+}
+
+impl PartialEq for FullInt {
+ #[must_use]
+ fn eq(&self, other: &Self) -> bool {
+ self.cmp(other) == Ordering::Equal
+ }
+}
+
+impl PartialOrd for FullInt {
+ #[must_use]
+ fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+ Some(self.cmp(other))
+ }
+}
+
+impl Ord for FullInt {
+ #[must_use]
+ fn cmp(&self, other: &Self) -> Ordering {
+ use FullInt::{S, U};
+
+ fn cmp_s_u(s: i128, u: u128) -> Ordering {
+ u128::try_from(s).map_or(Ordering::Less, |x| x.cmp(&u))
+ }
+
+ match (*self, *other) {
+ (S(s), S(o)) => s.cmp(&o),
+ (U(s), U(o)) => s.cmp(&o),
+ (S(s), U(o)) => cmp_s_u(s, o),
+ (U(s), S(o)) => cmp_s_u(o, s).reverse(),
+ }
+ }
+}
+
+/// Creates a `ConstEvalLateContext` from the given `LateContext` and `TypeckResults`.
+pub fn constant_context<'a, 'tcx>(
+ lcx: &'a LateContext<'tcx>,
+ typeck_results: &'a ty::TypeckResults<'tcx>,
+) -> ConstEvalLateContext<'a, 'tcx> {
+ ConstEvalLateContext {
+ lcx,
+ typeck_results,
+ param_env: lcx.param_env,
+ needed_resolution: false,
+ substs: lcx.tcx.intern_substs(&[]),
+ }
+}
+
+pub struct ConstEvalLateContext<'a, 'tcx> {
+ lcx: &'a LateContext<'tcx>,
+ typeck_results: &'a ty::TypeckResults<'tcx>,
+ param_env: ty::ParamEnv<'tcx>,
+ needed_resolution: bool,
+ substs: SubstsRef<'tcx>,
+}
+
+impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
+ /// Simple constant folding: Insert an expression, get a constant or none.
+ pub fn expr(&mut self, e: &Expr<'_>) -> Option<Constant> {
+ match e.kind {
+ ExprKind::Path(ref qpath) => self.fetch_path(qpath, e.hir_id, self.typeck_results.expr_ty(e)),
+ ExprKind::Block(block, _) => self.block(block),
+ ExprKind::Lit(ref lit) => {
+ if is_direct_expn_of(e.span, "cfg").is_some() {
+ None
+ } else {
+ Some(lit_to_mir_constant(&lit.node, self.typeck_results.expr_ty_opt(e)))
+ }
+ },
+ ExprKind::Array(vec) => self.multi(vec).map(Constant::Vec),
+ ExprKind::Tup(tup) => self.multi(tup).map(Constant::Tuple),
+ ExprKind::Repeat(value, _) => {
+ let n = match self.typeck_results.expr_ty(e).kind() {
+ ty::Array(_, n) => n.try_eval_usize(self.lcx.tcx, self.lcx.param_env)?,
+ _ => span_bug!(e.span, "typeck error"),
+ };
+ self.expr(value).map(|v| Constant::Repeat(Box::new(v), n))
+ },
+ ExprKind::Unary(op, operand) => self.expr(operand).and_then(|o| match op {
+ UnOp::Not => self.constant_not(&o, self.typeck_results.expr_ty(e)),
+ UnOp::Neg => self.constant_negate(&o, self.typeck_results.expr_ty(e)),
+ UnOp::Deref => Some(if let Constant::Ref(r) = o { *r } else { o }),
+ }),
+ ExprKind::If(cond, then, ref otherwise) => self.ifthenelse(cond, then, *otherwise),
+ ExprKind::Binary(op, left, right) => self.binop(op, left, right),
+ ExprKind::Call(callee, args) => {
+ // We only handle a few const functions for now.
+ if_chain! {
+ if args.is_empty();
+ if let ExprKind::Path(qpath) = &callee.kind;
+ let res = self.typeck_results.qpath_res(qpath, callee.hir_id);
+ if let Some(def_id) = res.opt_def_id();
+ let def_path = self.lcx.get_def_path(def_id);
+ let def_path: Vec<&str> = def_path.iter().take(4).map(Symbol::as_str).collect();
+ if let ["core", "num", int_impl, "max_value"] = *def_path;
+ then {
+ let value = match int_impl {
+ "<impl i8>" => i8::MAX as u128,
+ "<impl i16>" => i16::MAX as u128,
+ "<impl i32>" => i32::MAX as u128,
+ "<impl i64>" => i64::MAX as u128,
+ "<impl i128>" => i128::MAX as u128,
+ _ => return None,
+ };
+ Some(Constant::Int(value))
+ } else {
+ None
+ }
+ }
+ },
+ ExprKind::Index(arr, index) => self.index(arr, index),
+ ExprKind::AddrOf(_, _, inner) => self.expr(inner).map(|r| Constant::Ref(Box::new(r))),
+ // TODO: add other expressions.
+ _ => None,
+ }
+ }
+
+ #[expect(clippy::cast_possible_wrap)]
+ fn constant_not(&self, o: &Constant, ty: Ty<'_>) -> Option<Constant> {
+ use self::Constant::{Bool, Int};
+ match *o {
+ Bool(b) => Some(Bool(!b)),
+ Int(value) => {
+ let value = !value;
+ match *ty.kind() {
+ ty::Int(ity) => Some(Int(unsext(self.lcx.tcx, value as i128, ity))),
+ ty::Uint(ity) => Some(Int(clip(self.lcx.tcx, value, ity))),
+ _ => None,
+ }
+ },
+ _ => None,
+ }
+ }
+
+ fn constant_negate(&self, o: &Constant, ty: Ty<'_>) -> Option<Constant> {
+ use self::Constant::{Int, F32, F64};
+ match *o {
+ Int(value) => {
+ let ity = match *ty.kind() {
+ ty::Int(ity) => ity,
+ _ => return None,
+ };
+ // sign extend
+ let value = sext(self.lcx.tcx, value, ity);
+ let value = value.checked_neg()?;
+ // clear unused bits
+ Some(Int(unsext(self.lcx.tcx, value, ity)))
+ },
+ F32(f) => Some(F32(-f)),
+ F64(f) => Some(F64(-f)),
+ _ => None,
+ }
+ }
+
+ /// Create `Some(Vec![..])` of all constants, unless there is any
+ /// non-constant part.
+ fn multi(&mut self, vec: &[Expr<'_>]) -> Option<Vec<Constant>> {
+ vec.iter().map(|elem| self.expr(elem)).collect::<Option<_>>()
+ }
+
+ /// Lookup a possibly constant expression from an `ExprKind::Path`.
+ fn fetch_path(&mut self, qpath: &QPath<'_>, id: HirId, ty: Ty<'tcx>) -> Option<Constant> {
+ let res = self.typeck_results.qpath_res(qpath, id);
+ match res {
+ Res::Def(DefKind::Const | DefKind::AssocConst, def_id) => {
+ // Check if this constant is based on `cfg!(..)`,
+ // which is NOT constant for our purposes.
+ if let Some(node) = self.lcx.tcx.hir().get_if_local(def_id) &&
+ let Node::Item(&Item {
+ kind: ItemKind::Const(_, body_id),
+ ..
+ }) = node &&
+ let Node::Expr(&Expr {
+ kind: ExprKind::Lit(_),
+ span,
+ ..
+ }) = self.lcx.tcx.hir().get(body_id.hir_id) &&
+ is_direct_expn_of(span, "cfg").is_some() {
+ return None;
+ }
+
+ let substs = self.typeck_results.node_substs(id);
+ let substs = if self.substs.is_empty() {
+ substs
+ } else {
+ EarlyBinder(substs).subst(self.lcx.tcx, self.substs)
+ };
+
+ let result = self
+ .lcx
+ .tcx
+ .const_eval_resolve(
+ self.param_env,
+ ty::Unevaluated::new(ty::WithOptConstParam::unknown(def_id), substs),
+ None,
+ )
+ .ok()
+ .map(|val| rustc_middle::ty::Const::from_value(self.lcx.tcx, val, ty))?;
+ let result = miri_to_const(result);
+ if result.is_some() {
+ self.needed_resolution = true;
+ }
+ result
+ },
+ // FIXME: cover all usable cases.
+ _ => None,
+ }
+ }
+
+ fn index(&mut self, lhs: &'_ Expr<'_>, index: &'_ Expr<'_>) -> Option<Constant> {
+ let lhs = self.expr(lhs);
+ let index = self.expr(index);
+
+ match (lhs, index) {
+ (Some(Constant::Vec(vec)), Some(Constant::Int(index))) => match vec.get(index as usize) {
+ Some(Constant::F32(x)) => Some(Constant::F32(*x)),
+ Some(Constant::F64(x)) => Some(Constant::F64(*x)),
+ _ => None,
+ },
+ (Some(Constant::Vec(vec)), _) => {
+ if !vec.is_empty() && vec.iter().all(|x| *x == vec[0]) {
+ match vec.get(0) {
+ Some(Constant::F32(x)) => Some(Constant::F32(*x)),
+ Some(Constant::F64(x)) => Some(Constant::F64(*x)),
+ _ => None,
+ }
+ } else {
+ None
+ }
+ },
+ _ => None,
+ }
+ }
+
+ /// A block can only yield a constant if it only has one constant expression.
+ fn block(&mut self, block: &Block<'_>) -> Option<Constant> {
+ if block.stmts.is_empty() {
+ block.expr.as_ref().and_then(|b| self.expr(b))
+ } else {
+ None
+ }
+ }
+
+ fn ifthenelse(&mut self, cond: &Expr<'_>, then: &Expr<'_>, otherwise: Option<&Expr<'_>>) -> Option<Constant> {
+ if let Some(Constant::Bool(b)) = self.expr(cond) {
+ if b {
++ self.expr(then)
+ } else {
+ otherwise.as_ref().and_then(|expr| self.expr(expr))
+ }
+ } else {
+ None
+ }
+ }
+
+ fn binop(&mut self, op: BinOp, left: &Expr<'_>, right: &Expr<'_>) -> Option<Constant> {
+ let l = self.expr(left)?;
+ let r = self.expr(right);
+ match (l, r) {
+ (Constant::Int(l), Some(Constant::Int(r))) => match *self.typeck_results.expr_ty_opt(left)?.kind() {
+ ty::Int(ity) => {
+ let l = sext(self.lcx.tcx, l, ity);
+ let r = sext(self.lcx.tcx, r, ity);
+ let zext = |n: i128| Constant::Int(unsext(self.lcx.tcx, n, ity));
+ match op.node {
+ BinOpKind::Add => l.checked_add(r).map(zext),
+ BinOpKind::Sub => l.checked_sub(r).map(zext),
+ BinOpKind::Mul => l.checked_mul(r).map(zext),
+ BinOpKind::Div if r != 0 => l.checked_div(r).map(zext),
+ BinOpKind::Rem if r != 0 => l.checked_rem(r).map(zext),
+ BinOpKind::Shr => l.checked_shr(r.try_into().expect("invalid shift")).map(zext),
+ BinOpKind::Shl => l.checked_shl(r.try_into().expect("invalid shift")).map(zext),
+ BinOpKind::BitXor => Some(zext(l ^ r)),
+ BinOpKind::BitOr => Some(zext(l | r)),
+ BinOpKind::BitAnd => Some(zext(l & r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ }
+ },
+ ty::Uint(_) => match op.node {
+ BinOpKind::Add => l.checked_add(r).map(Constant::Int),
+ BinOpKind::Sub => l.checked_sub(r).map(Constant::Int),
+ BinOpKind::Mul => l.checked_mul(r).map(Constant::Int),
+ BinOpKind::Div => l.checked_div(r).map(Constant::Int),
+ BinOpKind::Rem => l.checked_rem(r).map(Constant::Int),
+ BinOpKind::Shr => l.checked_shr(r.try_into().expect("shift too large")).map(Constant::Int),
+ BinOpKind::Shl => l.checked_shl(r.try_into().expect("shift too large")).map(Constant::Int),
+ BinOpKind::BitXor => Some(Constant::Int(l ^ r)),
+ BinOpKind::BitOr => Some(Constant::Int(l | r)),
+ BinOpKind::BitAnd => Some(Constant::Int(l & r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ },
+ _ => None,
+ },
+ (Constant::F32(l), Some(Constant::F32(r))) => match op.node {
+ BinOpKind::Add => Some(Constant::F32(l + r)),
+ BinOpKind::Sub => Some(Constant::F32(l - r)),
+ BinOpKind::Mul => Some(Constant::F32(l * r)),
+ BinOpKind::Div => Some(Constant::F32(l / r)),
+ BinOpKind::Rem => Some(Constant::F32(l % r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ },
+ (Constant::F64(l), Some(Constant::F64(r))) => match op.node {
+ BinOpKind::Add => Some(Constant::F64(l + r)),
+ BinOpKind::Sub => Some(Constant::F64(l - r)),
+ BinOpKind::Mul => Some(Constant::F64(l * r)),
+ BinOpKind::Div => Some(Constant::F64(l / r)),
+ BinOpKind::Rem => Some(Constant::F64(l % r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ },
+ (l, r) => match (op.node, l, r) {
+ (BinOpKind::And, Constant::Bool(false), _) => Some(Constant::Bool(false)),
+ (BinOpKind::Or, Constant::Bool(true), _) => Some(Constant::Bool(true)),
+ (BinOpKind::And, Constant::Bool(true), Some(r)) | (BinOpKind::Or, Constant::Bool(false), Some(r)) => {
+ Some(r)
+ },
+ (BinOpKind::BitXor, Constant::Bool(l), Some(Constant::Bool(r))) => Some(Constant::Bool(l ^ r)),
+ (BinOpKind::BitAnd, Constant::Bool(l), Some(Constant::Bool(r))) => Some(Constant::Bool(l & r)),
+ (BinOpKind::BitOr, Constant::Bool(l), Some(Constant::Bool(r))) => Some(Constant::Bool(l | r)),
+ _ => None,
+ },
+ }
+ }
+}
+
+pub fn miri_to_const(result: ty::Const<'_>) -> Option<Constant> {
+ use rustc_middle::mir::interpret::ConstValue;
+ match result.val() {
+ ty::ConstKind::Value(ConstValue::Scalar(Scalar::Int(int))) => {
+ match result.ty().kind() {
+ ty::Bool => Some(Constant::Bool(int == ScalarInt::TRUE)),
+ ty::Uint(_) | ty::Int(_) => Some(Constant::Int(int.assert_bits(int.size()))),
+ ty::Float(FloatTy::F32) => Some(Constant::F32(f32::from_bits(
+ int.try_into().expect("invalid f32 bit representation"),
+ ))),
+ ty::Float(FloatTy::F64) => Some(Constant::F64(f64::from_bits(
+ int.try_into().expect("invalid f64 bit representation"),
+ ))),
+ ty::RawPtr(type_and_mut) => {
+ if let ty::Uint(_) = type_and_mut.ty.kind() {
+ return Some(Constant::RawPtr(int.assert_bits(int.size())));
+ }
+ None
+ },
+ // FIXME: implement other conversions.
+ _ => None,
+ }
+ },
+ ty::ConstKind::Value(ConstValue::Slice { data, start, end }) => match result.ty().kind() {
+ ty::Ref(_, tam, _) => match tam.kind() {
+ ty::Str => String::from_utf8(
+ data.inner()
+ .inspect_with_uninit_and_ptr_outside_interpreter(start..end)
+ .to_owned(),
+ )
+ .ok()
+ .map(Constant::Str),
+ _ => None,
+ },
+ _ => None,
+ },
+ ty::ConstKind::Value(ConstValue::ByRef { alloc, offset: _ }) => match result.ty().kind() {
+ ty::Array(sub_type, len) => match sub_type.kind() {
+ ty::Float(FloatTy::F32) => match miri_to_const(*len) {
+ Some(Constant::Int(len)) => alloc
+ .inner()
+ .inspect_with_uninit_and_ptr_outside_interpreter(0..(4 * len as usize))
+ .to_owned()
+ .chunks(4)
+ .map(|chunk| {
+ Some(Constant::F32(f32::from_le_bytes(
+ chunk.try_into().expect("this shouldn't happen"),
+ )))
+ })
+ .collect::<Option<Vec<Constant>>>()
+ .map(Constant::Vec),
+ _ => None,
+ },
+ ty::Float(FloatTy::F64) => match miri_to_const(*len) {
+ Some(Constant::Int(len)) => alloc
+ .inner()
+ .inspect_with_uninit_and_ptr_outside_interpreter(0..(8 * len as usize))
+ .to_owned()
+ .chunks(8)
+ .map(|chunk| {
+ Some(Constant::F64(f64::from_le_bytes(
+ chunk.try_into().expect("this shouldn't happen"),
+ )))
+ })
+ .collect::<Option<Vec<Constant>>>()
+ .map(Constant::Vec),
+ _ => None,
+ },
+ // FIXME: implement other array type conversions.
+ _ => None,
+ },
+ _ => None,
+ },
+ // FIXME: implement other conversions.
+ _ => None,
+ }
+}
--- /dev/null
- if let [stmt] = &*block.stmts;
+//! This module contains functions that retrieve specific elements.
+
+#![deny(clippy::missing_docs_in_private_items)]
+
+use crate::consts::{constant_simple, Constant};
+use crate::ty::is_type_diagnostic_item;
+use crate::{is_expn_of, match_def_path, paths};
+use if_chain::if_chain;
+use rustc_ast::ast;
+use rustc_hir as hir;
+use rustc_hir::{Arm, Block, Expr, ExprKind, HirId, LoopSource, MatchSource, Node, Pat, QPath};
+use rustc_lint::LateContext;
+use rustc_span::{sym, symbol, Span};
+
+/// The essential nodes of a desugared for loop as well as the entire span:
+/// `for pat in arg { body }` becomes `(pat, arg, body)`. Return `(pat, arg, body, span)`.
+pub struct ForLoop<'tcx> {
+ /// `for` loop item
+ pub pat: &'tcx hir::Pat<'tcx>,
+ /// `IntoIterator` argument
+ pub arg: &'tcx hir::Expr<'tcx>,
+ /// `for` loop body
+ pub body: &'tcx hir::Expr<'tcx>,
+ /// Compare this against `hir::Destination.target`
+ pub loop_id: HirId,
+ /// entire `for` loop span
+ pub span: Span,
+}
+
+impl<'tcx> ForLoop<'tcx> {
+ /// Parses a desugared `for` loop
+ pub fn hir(expr: &Expr<'tcx>) -> Option<Self> {
+ if_chain! {
+ if let hir::ExprKind::DropTemps(e) = expr.kind;
+ if let hir::ExprKind::Match(iterexpr, [arm], hir::MatchSource::ForLoopDesugar) = e.kind;
+ if let hir::ExprKind::Call(_, [arg]) = iterexpr.kind;
+ if let hir::ExprKind::Loop(block, ..) = arm.body.kind;
++ if let [stmt] = block.stmts;
+ if let hir::StmtKind::Expr(e) = stmt.kind;
+ if let hir::ExprKind::Match(_, [_, some_arm], _) = e.kind;
+ if let hir::PatKind::Struct(_, [field], _) = some_arm.pat.kind;
+ then {
+ return Some(Self {
+ pat: field.pat,
+ arg,
+ body: some_arm.body,
+ loop_id: arm.body.hir_id,
+ span: expr.span.ctxt().outer_expn_data().call_site,
+ });
+ }
+ }
+ None
+ }
+}
+
+/// An `if` expression without `DropTemps`
+pub struct If<'hir> {
+ /// `if` condition
+ pub cond: &'hir Expr<'hir>,
+ /// `if` then expression
+ pub then: &'hir Expr<'hir>,
+ /// `else` expression
+ pub r#else: Option<&'hir Expr<'hir>>,
+}
+
+impl<'hir> If<'hir> {
+ #[inline]
+ /// Parses an `if` expression
+ pub const fn hir(expr: &Expr<'hir>) -> Option<Self> {
+ if let ExprKind::If(
+ Expr {
+ kind: ExprKind::DropTemps(cond),
+ ..
+ },
+ then,
+ r#else,
+ ) = expr.kind
+ {
+ Some(Self { cond, then, r#else })
+ } else {
+ None
+ }
+ }
+}
+
+/// An `if let` expression
+pub struct IfLet<'hir> {
+ /// `if let` pattern
+ pub let_pat: &'hir Pat<'hir>,
+ /// `if let` scrutinee
+ pub let_expr: &'hir Expr<'hir>,
+ /// `if let` then expression
+ pub if_then: &'hir Expr<'hir>,
+ /// `if let` else expression
+ pub if_else: Option<&'hir Expr<'hir>>,
+}
+
+impl<'hir> IfLet<'hir> {
+ /// Parses an `if let` expression
+ pub fn hir(cx: &LateContext<'_>, expr: &Expr<'hir>) -> Option<Self> {
+ if let ExprKind::If(
+ Expr {
+ kind:
+ ExprKind::Let(hir::Let {
+ pat: let_pat,
+ init: let_expr,
+ ..
+ }),
+ ..
+ },
+ if_then,
+ if_else,
+ ) = expr.kind
+ {
+ let mut iter = cx.tcx.hir().parent_iter(expr.hir_id);
+ if let Some((_, Node::Block(Block { stmts: [], .. }))) = iter.next() {
+ if let Some((
+ _,
+ Node::Expr(Expr {
+ kind: ExprKind::Loop(_, _, LoopSource::While, _),
+ ..
+ }),
+ )) = iter.next()
+ {
+ // while loop desugar
+ return None;
+ }
+ }
+ return Some(Self {
+ let_pat,
+ let_expr,
+ if_then,
+ if_else,
+ });
+ }
+ None
+ }
+}
+
+/// An `if let` or `match` expression. Useful for lints that trigger on one or the other.
+pub enum IfLetOrMatch<'hir> {
+ /// Any `match` expression
+ Match(&'hir Expr<'hir>, &'hir [Arm<'hir>], MatchSource),
+ /// scrutinee, pattern, then block, else block
+ IfLet(
+ &'hir Expr<'hir>,
+ &'hir Pat<'hir>,
+ &'hir Expr<'hir>,
+ Option<&'hir Expr<'hir>>,
+ ),
+}
+
+impl<'hir> IfLetOrMatch<'hir> {
+ /// Parses an `if let` or `match` expression
+ pub fn parse(cx: &LateContext<'_>, expr: &Expr<'hir>) -> Option<Self> {
+ match expr.kind {
+ ExprKind::Match(expr, arms, source) => Some(Self::Match(expr, arms, source)),
+ _ => IfLet::hir(cx, expr).map(
+ |IfLet {
+ let_expr,
+ let_pat,
+ if_then,
+ if_else,
+ }| { Self::IfLet(let_expr, let_pat, if_then, if_else) },
+ ),
+ }
+ }
+}
+
+/// An `if` or `if let` expression
+pub struct IfOrIfLet<'hir> {
+ /// `if` condition that is maybe a `let` expression
+ pub cond: &'hir Expr<'hir>,
+ /// `if` then expression
+ pub then: &'hir Expr<'hir>,
+ /// `else` expression
+ pub r#else: Option<&'hir Expr<'hir>>,
+}
+
+impl<'hir> IfOrIfLet<'hir> {
+ #[inline]
+ /// Parses an `if` or `if let` expression
+ pub const fn hir(expr: &Expr<'hir>) -> Option<Self> {
+ if let ExprKind::If(cond, then, r#else) = expr.kind {
+ if let ExprKind::DropTemps(new_cond) = cond.kind {
+ return Some(Self {
+ cond: new_cond,
+ r#else,
+ then,
+ });
+ }
+ if let ExprKind::Let(..) = cond.kind {
+ return Some(Self { cond, then, r#else });
+ }
+ }
+ None
+ }
+}
+
+/// Represent a range akin to `ast::ExprKind::Range`.
+#[derive(Debug, Copy, Clone)]
+pub struct Range<'a> {
+ /// The lower bound of the range, or `None` for ranges such as `..X`.
+ pub start: Option<&'a hir::Expr<'a>>,
+ /// The upper bound of the range, or `None` for ranges such as `X..`.
+ pub end: Option<&'a hir::Expr<'a>>,
+ /// Whether the interval is open or closed.
+ pub limits: ast::RangeLimits,
+}
+
+impl<'a> Range<'a> {
+ /// Higher a `hir` range to something similar to `ast::ExprKind::Range`.
+ pub fn hir(expr: &'a hir::Expr<'_>) -> Option<Range<'a>> {
+ /// Finds the field named `name` in the field. Always return `Some` for
+ /// convenience.
+ fn get_field<'c>(name: &str, fields: &'c [hir::ExprField<'_>]) -> Option<&'c hir::Expr<'c>> {
+ let expr = &fields.iter().find(|field| field.ident.name.as_str() == name)?.expr;
+ Some(expr)
+ }
+
+ match expr.kind {
+ hir::ExprKind::Call(path, args)
+ if matches!(
+ path.kind,
+ hir::ExprKind::Path(hir::QPath::LangItem(hir::LangItem::RangeInclusiveNew, ..))
+ ) =>
+ {
+ Some(Range {
+ start: Some(&args[0]),
+ end: Some(&args[1]),
+ limits: ast::RangeLimits::Closed,
+ })
+ },
+ hir::ExprKind::Struct(path, fields, None) => match &path {
+ hir::QPath::LangItem(hir::LangItem::RangeFull, ..) => Some(Range {
+ start: None,
+ end: None,
+ limits: ast::RangeLimits::HalfOpen,
+ }),
+ hir::QPath::LangItem(hir::LangItem::RangeFrom, ..) => Some(Range {
+ start: Some(get_field("start", fields)?),
+ end: None,
+ limits: ast::RangeLimits::HalfOpen,
+ }),
+ hir::QPath::LangItem(hir::LangItem::Range, ..) => Some(Range {
+ start: Some(get_field("start", fields)?),
+ end: Some(get_field("end", fields)?),
+ limits: ast::RangeLimits::HalfOpen,
+ }),
+ hir::QPath::LangItem(hir::LangItem::RangeToInclusive, ..) => Some(Range {
+ start: None,
+ end: Some(get_field("end", fields)?),
+ limits: ast::RangeLimits::Closed,
+ }),
+ hir::QPath::LangItem(hir::LangItem::RangeTo, ..) => Some(Range {
+ start: None,
+ end: Some(get_field("end", fields)?),
+ limits: ast::RangeLimits::HalfOpen,
+ }),
+ _ => None,
+ },
+ _ => None,
+ }
+ }
+}
+
+/// Represent the pre-expansion arguments of a `vec!` invocation.
+pub enum VecArgs<'a> {
+ /// `vec![elem; len]`
+ Repeat(&'a hir::Expr<'a>, &'a hir::Expr<'a>),
+ /// `vec![a, b, c]`
+ Vec(&'a [hir::Expr<'a>]),
+}
+
+impl<'a> VecArgs<'a> {
+ /// Returns the arguments of the `vec!` macro if this expression was expanded
+ /// from `vec!`.
+ pub fn hir(cx: &LateContext<'_>, expr: &'a hir::Expr<'_>) -> Option<VecArgs<'a>> {
+ if_chain! {
+ if let hir::ExprKind::Call(fun, args) = expr.kind;
+ if let hir::ExprKind::Path(ref qpath) = fun.kind;
+ if is_expn_of(fun.span, "vec").is_some();
+ if let Some(fun_def_id) = cx.qpath_res(qpath, fun.hir_id).opt_def_id();
+ then {
+ return if match_def_path(cx, fun_def_id, &paths::VEC_FROM_ELEM) && args.len() == 2 {
+ // `vec![elem; size]` case
+ Some(VecArgs::Repeat(&args[0], &args[1]))
+ } else if match_def_path(cx, fun_def_id, &paths::SLICE_INTO_VEC) && args.len() == 1 {
+ // `vec![a, b, c]` case
+ if_chain! {
+ if let hir::ExprKind::Box(boxed) = args[0].kind;
+ if let hir::ExprKind::Array(args) = boxed.kind;
+ then {
+ return Some(VecArgs::Vec(args));
+ }
+ }
+
+ None
+ } else if match_def_path(cx, fun_def_id, &paths::VEC_NEW) && args.is_empty() {
+ Some(VecArgs::Vec(&[]))
+ } else {
+ None
+ };
+ }
+ }
+
+ None
+ }
+}
+
+/// A desugared `while` loop
+pub struct While<'hir> {
+ /// `while` loop condition
+ pub condition: &'hir Expr<'hir>,
+ /// `while` loop body
+ pub body: &'hir Expr<'hir>,
+}
+
+impl<'hir> While<'hir> {
+ #[inline]
+ /// Parses a desugared `while` loop
+ pub const fn hir(expr: &Expr<'hir>) -> Option<Self> {
+ if let ExprKind::Loop(
+ Block {
+ expr:
+ Some(Expr {
+ kind:
+ ExprKind::If(
+ Expr {
+ kind: ExprKind::DropTemps(condition),
+ ..
+ },
+ body,
+ _,
+ ),
+ ..
+ }),
+ ..
+ },
+ _,
+ LoopSource::While,
+ _,
+ ) = expr.kind
+ {
+ return Some(Self { condition, body });
+ }
+ None
+ }
+}
+
+/// A desugared `while let` loop
+pub struct WhileLet<'hir> {
+ /// `while let` loop item pattern
+ pub let_pat: &'hir Pat<'hir>,
+ /// `while let` loop scrutinee
+ pub let_expr: &'hir Expr<'hir>,
+ /// `while let` loop body
+ pub if_then: &'hir Expr<'hir>,
+}
+
+impl<'hir> WhileLet<'hir> {
+ #[inline]
+ /// Parses a desugared `while let` loop
+ pub const fn hir(expr: &Expr<'hir>) -> Option<Self> {
+ if let ExprKind::Loop(
+ Block {
+ expr:
+ Some(Expr {
+ kind:
+ ExprKind::If(
+ Expr {
+ kind:
+ ExprKind::Let(hir::Let {
+ pat: let_pat,
+ init: let_expr,
+ ..
+ }),
+ ..
+ },
+ if_then,
+ _,
+ ),
+ ..
+ }),
+ ..
+ },
+ _,
+ LoopSource::While,
+ _,
+ ) = expr.kind
+ {
+ return Some(Self {
+ let_pat,
+ let_expr,
+ if_then,
+ });
+ }
+ None
+ }
+}
+
+/// Converts a hir binary operator to the corresponding `ast` type.
+#[must_use]
+pub fn binop(op: hir::BinOpKind) -> ast::BinOpKind {
+ match op {
+ hir::BinOpKind::Eq => ast::BinOpKind::Eq,
+ hir::BinOpKind::Ge => ast::BinOpKind::Ge,
+ hir::BinOpKind::Gt => ast::BinOpKind::Gt,
+ hir::BinOpKind::Le => ast::BinOpKind::Le,
+ hir::BinOpKind::Lt => ast::BinOpKind::Lt,
+ hir::BinOpKind::Ne => ast::BinOpKind::Ne,
+ hir::BinOpKind::Or => ast::BinOpKind::Or,
+ hir::BinOpKind::Add => ast::BinOpKind::Add,
+ hir::BinOpKind::And => ast::BinOpKind::And,
+ hir::BinOpKind::BitAnd => ast::BinOpKind::BitAnd,
+ hir::BinOpKind::BitOr => ast::BinOpKind::BitOr,
+ hir::BinOpKind::BitXor => ast::BinOpKind::BitXor,
+ hir::BinOpKind::Div => ast::BinOpKind::Div,
+ hir::BinOpKind::Mul => ast::BinOpKind::Mul,
+ hir::BinOpKind::Rem => ast::BinOpKind::Rem,
+ hir::BinOpKind::Shl => ast::BinOpKind::Shl,
+ hir::BinOpKind::Shr => ast::BinOpKind::Shr,
+ hir::BinOpKind::Sub => ast::BinOpKind::Sub,
+ }
+}
+
+/// A parsed `Vec` initialization expression
+#[derive(Clone, Copy)]
+pub enum VecInitKind {
+ /// `Vec::new()`
+ New,
+ /// `Vec::default()` or `Default::default()`
+ Default,
+ /// `Vec::with_capacity(123)`
+ WithConstCapacity(u128),
+ /// `Vec::with_capacity(slice.len())`
+ WithExprCapacity(HirId),
+}
+
+/// Checks if given expression is an initialization of `Vec` and returns its kind.
+pub fn get_vec_init_kind<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option<VecInitKind> {
+ if let ExprKind::Call(func, args) = expr.kind {
+ match func.kind {
+ ExprKind::Path(QPath::TypeRelative(ty, name))
+ if is_type_diagnostic_item(cx, cx.typeck_results().node_type(ty.hir_id), sym::Vec) =>
+ {
+ if name.ident.name == sym::new {
+ return Some(VecInitKind::New);
+ } else if name.ident.name == symbol::kw::Default {
+ return Some(VecInitKind::Default);
+ } else if name.ident.name.as_str() == "with_capacity" {
+ let arg = args.get(0)?;
+ return match constant_simple(cx, cx.typeck_results(), arg) {
+ Some(Constant::Int(num)) => Some(VecInitKind::WithConstCapacity(num)),
+ _ => Some(VecInitKind::WithExprCapacity(arg.hir_id)),
+ };
+ };
+ },
+ ExprKind::Path(QPath::Resolved(_, path))
+ if match_def_path(cx, path.res.opt_def_id()?, &paths::DEFAULT_TRAIT_METHOD)
+ && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::Vec) =>
+ {
+ return Some(VecInitKind::Default);
+ },
+ _ => (),
+ }
+ }
+ None
+}
--- /dev/null
- l_mut.mutbl == r_mut.mutbl && self.eq_ty(&*l_mut.ty, &*r_mut.ty)
+use crate::consts::constant_simple;
+use crate::source::snippet_opt;
+use rustc_ast::ast::InlineAsmTemplatePiece;
+use rustc_data_structures::fx::FxHasher;
+use rustc_hir::def::Res;
+use rustc_hir::HirIdMap;
+use rustc_hir::{
+ ArrayLen, BinOpKind, Block, BodyId, Expr, ExprField, ExprKind, FnRetTy, GenericArg, GenericArgs, Guard, HirId,
+ InlineAsmOperand, Let, Lifetime, LifetimeName, ParamName, Pat, PatField, PatKind, Path, PathSegment, QPath, Stmt,
+ StmtKind, Ty, TyKind, TypeBinding,
+};
+use rustc_lexer::{tokenize, TokenKind};
+use rustc_lint::LateContext;
+use rustc_middle::ty::TypeckResults;
+use rustc_span::Symbol;
+use std::hash::{Hash, Hasher};
+
+/// Type used to check whether two ast are the same. This is different from the
+/// operator `==` on ast types as this operator would compare true equality with
+/// ID and span.
+///
+/// Note that some expressions kinds are not considered but could be added.
+pub struct SpanlessEq<'a, 'tcx> {
+ /// Context used to evaluate constant expressions.
+ cx: &'a LateContext<'tcx>,
+ maybe_typeck_results: Option<(&'tcx TypeckResults<'tcx>, &'tcx TypeckResults<'tcx>)>,
+ allow_side_effects: bool,
+ expr_fallback: Option<Box<dyn FnMut(&Expr<'_>, &Expr<'_>) -> bool + 'a>>,
+}
+
+impl<'a, 'tcx> SpanlessEq<'a, 'tcx> {
+ pub fn new(cx: &'a LateContext<'tcx>) -> Self {
+ Self {
+ cx,
+ maybe_typeck_results: cx.maybe_typeck_results().map(|x| (x, x)),
+ allow_side_effects: true,
+ expr_fallback: None,
+ }
+ }
+
+ /// Consider expressions containing potential side effects as not equal.
+ #[must_use]
+ pub fn deny_side_effects(self) -> Self {
+ Self {
+ allow_side_effects: false,
+ ..self
+ }
+ }
+
+ #[must_use]
+ pub fn expr_fallback(self, expr_fallback: impl FnMut(&Expr<'_>, &Expr<'_>) -> bool + 'a) -> Self {
+ Self {
+ expr_fallback: Some(Box::new(expr_fallback)),
+ ..self
+ }
+ }
+
+ /// Use this method to wrap comparisons that may involve inter-expression context.
+ /// See `self.locals`.
+ pub fn inter_expr(&mut self) -> HirEqInterExpr<'_, 'a, 'tcx> {
+ HirEqInterExpr {
+ inner: self,
+ locals: HirIdMap::default(),
+ }
+ }
+
+ pub fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
+ self.inter_expr().eq_block(left, right)
+ }
+
+ pub fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
+ self.inter_expr().eq_expr(left, right)
+ }
+
+ pub fn eq_path(&mut self, left: &Path<'_>, right: &Path<'_>) -> bool {
+ self.inter_expr().eq_path(left, right)
+ }
+
+ pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
+ self.inter_expr().eq_path_segment(left, right)
+ }
+
+ pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
+ self.inter_expr().eq_path_segments(left, right)
+ }
+}
+
+pub struct HirEqInterExpr<'a, 'b, 'tcx> {
+ inner: &'a mut SpanlessEq<'b, 'tcx>,
+
+ // When binding are declared, the binding ID in the left expression is mapped to the one on the
+ // right. For example, when comparing `{ let x = 1; x + 2 }` and `{ let y = 1; y + 2 }`,
+ // these blocks are considered equal since `x` is mapped to `y`.
+ locals: HirIdMap<HirId>,
+}
+
+impl HirEqInterExpr<'_, '_, '_> {
+ pub fn eq_stmt(&mut self, left: &Stmt<'_>, right: &Stmt<'_>) -> bool {
+ match (&left.kind, &right.kind) {
+ (&StmtKind::Local(l), &StmtKind::Local(r)) => {
+ // This additional check ensures that the type of the locals are equivalent even if the init
+ // expression or type have some inferred parts.
+ if let Some((typeck_lhs, typeck_rhs)) = self.inner.maybe_typeck_results {
+ let l_ty = typeck_lhs.pat_ty(l.pat);
+ let r_ty = typeck_rhs.pat_ty(r.pat);
+ if l_ty != r_ty {
+ return false;
+ }
+ }
+
+ // eq_pat adds the HirIds to the locals map. We therefor call it last to make sure that
+ // these only get added if the init and type is equal.
+ both(&l.init, &r.init, |l, r| self.eq_expr(l, r))
+ && both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r))
+ && self.eq_pat(l.pat, r.pat)
+ },
+ (&StmtKind::Expr(l), &StmtKind::Expr(r)) | (&StmtKind::Semi(l), &StmtKind::Semi(r)) => self.eq_expr(l, r),
+ _ => false,
+ }
+ }
+
+ /// Checks whether two blocks are the same.
+ fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
+ match (left.stmts, left.expr, right.stmts, right.expr) {
+ ([], None, [], None) => {
+ // For empty blocks, check to see if the tokens are equal. This will catch the case where a macro
+ // expanded to nothing, or the cfg attribute was used.
+ let (left, right) = match (
+ snippet_opt(self.inner.cx, left.span),
+ snippet_opt(self.inner.cx, right.span),
+ ) {
+ (Some(left), Some(right)) => (left, right),
+ _ => return true,
+ };
+ let mut left_pos = 0;
+ let left = tokenize(&left)
+ .map(|t| {
+ let end = left_pos + t.len;
+ let s = &left[left_pos..end];
+ left_pos = end;
+ (t, s)
+ })
+ .filter(|(t, _)| {
+ !matches!(
+ t.kind,
+ TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
+ )
+ })
+ .map(|(_, s)| s);
+ let mut right_pos = 0;
+ let right = tokenize(&right)
+ .map(|t| {
+ let end = right_pos + t.len;
+ let s = &right[right_pos..end];
+ right_pos = end;
+ (t, s)
+ })
+ .filter(|(t, _)| {
+ !matches!(
+ t.kind,
+ TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
+ )
+ })
+ .map(|(_, s)| s);
+ left.eq(right)
+ },
+ _ => {
+ over(left.stmts, right.stmts, |l, r| self.eq_stmt(l, r))
+ && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
+ },
+ }
+ }
+
+ pub fn eq_array_length(&mut self, left: ArrayLen, right: ArrayLen) -> bool {
+ match (left, right) {
+ (ArrayLen::Infer(..), ArrayLen::Infer(..)) => true,
+ (ArrayLen::Body(l_ct), ArrayLen::Body(r_ct)) => self.eq_body(l_ct.body, r_ct.body),
+ (_, _) => false,
+ }
+ }
+
+ pub fn eq_body(&mut self, left: BodyId, right: BodyId) -> bool {
+ // swap out TypeckResults when hashing a body
+ let old_maybe_typeck_results = self.inner.maybe_typeck_results.replace((
+ self.inner.cx.tcx.typeck_body(left),
+ self.inner.cx.tcx.typeck_body(right),
+ ));
+ let res = self.eq_expr(
+ &self.inner.cx.tcx.hir().body(left).value,
+ &self.inner.cx.tcx.hir().body(right).value,
+ );
+ self.inner.maybe_typeck_results = old_maybe_typeck_results;
+ res
+ }
+
+ #[expect(clippy::similar_names)]
+ pub fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
+ if !self.inner.allow_side_effects && left.span.ctxt() != right.span.ctxt() {
+ return false;
+ }
+
+ if let Some((typeck_lhs, typeck_rhs)) = self.inner.maybe_typeck_results {
+ if let (Some(l), Some(r)) = (
+ constant_simple(self.inner.cx, typeck_lhs, left),
+ constant_simple(self.inner.cx, typeck_rhs, right),
+ ) {
+ if l == r {
+ return true;
+ }
+ }
+ }
+
+ let is_eq = match (
+ reduce_exprkind(self.inner.cx, &left.kind),
+ reduce_exprkind(self.inner.cx, &right.kind),
+ ) {
+ (&ExprKind::AddrOf(lb, l_mut, le), &ExprKind::AddrOf(rb, r_mut, re)) => {
+ lb == rb && l_mut == r_mut && self.eq_expr(le, re)
+ },
+ (&ExprKind::Continue(li), &ExprKind::Continue(ri)) => {
+ both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
+ },
+ (&ExprKind::Assign(ll, lr, _), &ExprKind::Assign(rl, rr, _)) => {
+ self.inner.allow_side_effects && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
+ },
+ (&ExprKind::AssignOp(ref lo, ll, lr), &ExprKind::AssignOp(ref ro, rl, rr)) => {
+ self.inner.allow_side_effects && lo.node == ro.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
+ },
+ (&ExprKind::Block(l, _), &ExprKind::Block(r, _)) => self.eq_block(l, r),
+ (&ExprKind::Binary(l_op, ll, lr), &ExprKind::Binary(r_op, rl, rr)) => {
+ l_op.node == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
+ || swap_binop(l_op.node, ll, lr).map_or(false, |(l_op, ll, lr)| {
+ l_op == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
+ })
+ },
+ (&ExprKind::Break(li, ref le), &ExprKind::Break(ri, ref re)) => {
+ both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
+ && both(le, re, |l, r| self.eq_expr(l, r))
+ },
+ (&ExprKind::Box(l), &ExprKind::Box(r)) => self.eq_expr(l, r),
+ (&ExprKind::Call(l_fun, l_args), &ExprKind::Call(r_fun, r_args)) => {
+ self.inner.allow_side_effects && self.eq_expr(l_fun, r_fun) && self.eq_exprs(l_args, r_args)
+ },
+ (&ExprKind::Cast(lx, lt), &ExprKind::Cast(rx, rt)) | (&ExprKind::Type(lx, lt), &ExprKind::Type(rx, rt)) => {
+ self.eq_expr(lx, rx) && self.eq_ty(lt, rt)
+ },
+ (&ExprKind::Field(l_f_exp, ref l_f_ident), &ExprKind::Field(r_f_exp, ref r_f_ident)) => {
+ l_f_ident.name == r_f_ident.name && self.eq_expr(l_f_exp, r_f_exp)
+ },
+ (&ExprKind::Index(la, li), &ExprKind::Index(ra, ri)) => self.eq_expr(la, ra) && self.eq_expr(li, ri),
+ (&ExprKind::If(lc, lt, ref le), &ExprKind::If(rc, rt, ref re)) => {
+ self.eq_expr(lc, rc) && self.eq_expr(lt, rt) && both(le, re, |l, r| self.eq_expr(l, r))
+ },
+ (&ExprKind::Let(l), &ExprKind::Let(r)) => {
+ self.eq_pat(l.pat, r.pat) && both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r)) && self.eq_expr(l.init, r.init)
+ },
+ (&ExprKind::Lit(ref l), &ExprKind::Lit(ref r)) => l.node == r.node,
+ (&ExprKind::Loop(lb, ref ll, ref lls, _), &ExprKind::Loop(rb, ref rl, ref rls, _)) => {
+ lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.ident.name == r.ident.name)
+ },
+ (&ExprKind::Match(le, la, ref ls), &ExprKind::Match(re, ra, ref rs)) => {
+ ls == rs
+ && self.eq_expr(le, re)
+ && over(la, ra, |l, r| {
+ self.eq_pat(l.pat, r.pat)
+ && both(&l.guard, &r.guard, |l, r| self.eq_guard(l, r))
+ && self.eq_expr(l.body, r.body)
+ })
+ },
+ (&ExprKind::MethodCall(l_path, l_args, _), &ExprKind::MethodCall(r_path, r_args, _)) => {
+ self.inner.allow_side_effects && self.eq_path_segment(l_path, r_path) && self.eq_exprs(l_args, r_args)
+ },
+ (&ExprKind::Repeat(le, ll), &ExprKind::Repeat(re, rl)) => {
+ self.eq_expr(le, re) && self.eq_array_length(ll, rl)
+ },
+ (&ExprKind::Ret(ref l), &ExprKind::Ret(ref r)) => both(l, r, |l, r| self.eq_expr(l, r)),
+ (&ExprKind::Path(ref l), &ExprKind::Path(ref r)) => self.eq_qpath(l, r),
+ (&ExprKind::Struct(l_path, lf, ref lo), &ExprKind::Struct(r_path, rf, ref ro)) => {
+ self.eq_qpath(l_path, r_path)
+ && both(lo, ro, |l, r| self.eq_expr(l, r))
+ && over(lf, rf, |l, r| self.eq_expr_field(l, r))
+ },
+ (&ExprKind::Tup(l_tup), &ExprKind::Tup(r_tup)) => self.eq_exprs(l_tup, r_tup),
+ (&ExprKind::Unary(l_op, le), &ExprKind::Unary(r_op, re)) => l_op == r_op && self.eq_expr(le, re),
+ (&ExprKind::Array(l), &ExprKind::Array(r)) => self.eq_exprs(l, r),
+ (&ExprKind::DropTemps(le), &ExprKind::DropTemps(re)) => self.eq_expr(le, re),
+ _ => false,
+ };
+ is_eq || self.inner.expr_fallback.as_mut().map_or(false, |f| f(left, right))
+ }
+
+ fn eq_exprs(&mut self, left: &[Expr<'_>], right: &[Expr<'_>]) -> bool {
+ over(left, right, |l, r| self.eq_expr(l, r))
+ }
+
+ fn eq_expr_field(&mut self, left: &ExprField<'_>, right: &ExprField<'_>) -> bool {
+ left.ident.name == right.ident.name && self.eq_expr(left.expr, right.expr)
+ }
+
+ fn eq_guard(&mut self, left: &Guard<'_>, right: &Guard<'_>) -> bool {
+ match (left, right) {
+ (Guard::If(l), Guard::If(r)) => self.eq_expr(l, r),
+ (Guard::IfLet(l), Guard::IfLet(r)) => {
+ self.eq_pat(l.pat, r.pat) && both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r)) && self.eq_expr(l.init, r.init)
+ },
+ _ => false,
+ }
+ }
+
+ fn eq_generic_arg(&mut self, left: &GenericArg<'_>, right: &GenericArg<'_>) -> bool {
+ match (left, right) {
+ (GenericArg::Const(l), GenericArg::Const(r)) => self.eq_body(l.value.body, r.value.body),
+ (GenericArg::Lifetime(l_lt), GenericArg::Lifetime(r_lt)) => Self::eq_lifetime(l_lt, r_lt),
+ (GenericArg::Type(l_ty), GenericArg::Type(r_ty)) => self.eq_ty(l_ty, r_ty),
+ (GenericArg::Infer(l_inf), GenericArg::Infer(r_inf)) => self.eq_ty(&l_inf.to_ty(), &r_inf.to_ty()),
+ _ => false,
+ }
+ }
+
+ fn eq_lifetime(left: &Lifetime, right: &Lifetime) -> bool {
+ left.name == right.name
+ }
+
+ fn eq_pat_field(&mut self, left: &PatField<'_>, right: &PatField<'_>) -> bool {
+ let (PatField { ident: li, pat: lp, .. }, PatField { ident: ri, pat: rp, .. }) = (&left, &right);
+ li.name == ri.name && self.eq_pat(lp, rp)
+ }
+
+ /// Checks whether two patterns are the same.
+ fn eq_pat(&mut self, left: &Pat<'_>, right: &Pat<'_>) -> bool {
+ match (&left.kind, &right.kind) {
+ (&PatKind::Box(l), &PatKind::Box(r)) => self.eq_pat(l, r),
+ (&PatKind::Struct(ref lp, la, ..), &PatKind::Struct(ref rp, ra, ..)) => {
+ self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat_field(l, r))
+ },
+ (&PatKind::TupleStruct(ref lp, la, ls), &PatKind::TupleStruct(ref rp, ra, rs)) => {
+ self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat(l, r)) && ls == rs
+ },
+ (&PatKind::Binding(lb, li, _, ref lp), &PatKind::Binding(rb, ri, _, ref rp)) => {
+ let eq = lb == rb && both(lp, rp, |l, r| self.eq_pat(l, r));
+ if eq {
+ self.locals.insert(li, ri);
+ }
+ eq
+ },
+ (&PatKind::Path(ref l), &PatKind::Path(ref r)) => self.eq_qpath(l, r),
+ (&PatKind::Lit(l), &PatKind::Lit(r)) => self.eq_expr(l, r),
+ (&PatKind::Tuple(l, ls), &PatKind::Tuple(r, rs)) => ls == rs && over(l, r, |l, r| self.eq_pat(l, r)),
+ (&PatKind::Range(ref ls, ref le, li), &PatKind::Range(ref rs, ref re, ri)) => {
+ both(ls, rs, |a, b| self.eq_expr(a, b)) && both(le, re, |a, b| self.eq_expr(a, b)) && (li == ri)
+ },
+ (&PatKind::Ref(le, ref lm), &PatKind::Ref(re, ref rm)) => lm == rm && self.eq_pat(le, re),
+ (&PatKind::Slice(ls, ref li, le), &PatKind::Slice(rs, ref ri, re)) => {
+ over(ls, rs, |l, r| self.eq_pat(l, r))
+ && over(le, re, |l, r| self.eq_pat(l, r))
+ && both(li, ri, |l, r| self.eq_pat(l, r))
+ },
+ (&PatKind::Wild, &PatKind::Wild) => true,
+ _ => false,
+ }
+ }
+
+ #[expect(clippy::similar_names)]
+ fn eq_qpath(&mut self, left: &QPath<'_>, right: &QPath<'_>) -> bool {
+ match (left, right) {
+ (&QPath::Resolved(ref lty, lpath), &QPath::Resolved(ref rty, rpath)) => {
+ both(lty, rty, |l, r| self.eq_ty(l, r)) && self.eq_path(lpath, rpath)
+ },
+ (&QPath::TypeRelative(lty, lseg), &QPath::TypeRelative(rty, rseg)) => {
+ self.eq_ty(lty, rty) && self.eq_path_segment(lseg, rseg)
+ },
+ (&QPath::LangItem(llang_item, ..), &QPath::LangItem(rlang_item, ..)) => llang_item == rlang_item,
+ _ => false,
+ }
+ }
+
+ pub fn eq_path(&mut self, left: &Path<'_>, right: &Path<'_>) -> bool {
+ match (left.res, right.res) {
+ (Res::Local(l), Res::Local(r)) => l == r || self.locals.get(&l) == Some(&r),
+ (Res::Local(_), _) | (_, Res::Local(_)) => false,
+ _ => over(left.segments, right.segments, |l, r| self.eq_path_segment(l, r)),
+ }
+ }
+
+ fn eq_path_parameters(&mut self, left: &GenericArgs<'_>, right: &GenericArgs<'_>) -> bool {
+ if !(left.parenthesized || right.parenthesized) {
+ over(left.args, right.args, |l, r| self.eq_generic_arg(l, r)) // FIXME(flip1995): may not work
+ && over(left.bindings, right.bindings, |l, r| self.eq_type_binding(l, r))
+ } else if left.parenthesized && right.parenthesized {
+ over(left.inputs(), right.inputs(), |l, r| self.eq_ty(l, r))
+ && both(&Some(&left.bindings[0].ty()), &Some(&right.bindings[0].ty()), |l, r| {
+ self.eq_ty(l, r)
+ })
+ } else {
+ false
+ }
+ }
+
+ pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
+ left.len() == right.len() && left.iter().zip(right).all(|(l, r)| self.eq_path_segment(l, r))
+ }
+
+ pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
+ // The == of idents doesn't work with different contexts,
+ // we have to be explicit about hygiene
+ left.ident.name == right.ident.name && both(&left.args, &right.args, |l, r| self.eq_path_parameters(l, r))
+ }
+
+ pub fn eq_ty(&mut self, left: &Ty<'_>, right: &Ty<'_>) -> bool {
+ match (&left.kind, &right.kind) {
+ (&TyKind::Slice(l_vec), &TyKind::Slice(r_vec)) => self.eq_ty(l_vec, r_vec),
+ (&TyKind::Array(lt, ll), &TyKind::Array(rt, rl)) => self.eq_ty(lt, rt) && self.eq_array_length(ll, rl),
+ (&TyKind::Ptr(ref l_mut), &TyKind::Ptr(ref r_mut)) => {
- l_rmut.mutbl == r_rmut.mutbl && self.eq_ty(&*l_rmut.ty, &*r_rmut.ty)
++ l_mut.mutbl == r_mut.mutbl && self.eq_ty(l_mut.ty, r_mut.ty)
+ },
+ (&TyKind::Rptr(_, ref l_rmut), &TyKind::Rptr(_, ref r_rmut)) => {
- self.hash_expr(&*j);
++ l_rmut.mutbl == r_rmut.mutbl && self.eq_ty(l_rmut.ty, r_rmut.ty)
+ },
+ (&TyKind::Path(ref l), &TyKind::Path(ref r)) => self.eq_qpath(l, r),
+ (&TyKind::Tup(l), &TyKind::Tup(r)) => over(l, r, |l, r| self.eq_ty(l, r)),
+ (&TyKind::Infer, &TyKind::Infer) => true,
+ _ => false,
+ }
+ }
+
+ fn eq_type_binding(&mut self, left: &TypeBinding<'_>, right: &TypeBinding<'_>) -> bool {
+ left.ident.name == right.ident.name && self.eq_ty(left.ty(), right.ty())
+ }
+}
+
+/// Some simple reductions like `{ return }` => `return`
+fn reduce_exprkind<'hir>(cx: &LateContext<'_>, kind: &'hir ExprKind<'hir>) -> &'hir ExprKind<'hir> {
+ if let ExprKind::Block(block, _) = kind {
+ match (block.stmts, block.expr) {
+ // From an `if let` expression without an `else` block. The arm for the implicit wild pattern is an empty
+ // block with an empty span.
+ ([], None) if block.span.is_empty() => &ExprKind::Tup(&[]),
+ // `{}` => `()`
+ ([], None) => match snippet_opt(cx, block.span) {
+ // Don't reduce if there are any tokens contained in the braces
+ Some(snip)
+ if tokenize(&snip)
+ .map(|t| t.kind)
+ .filter(|t| {
+ !matches!(
+ t,
+ TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
+ )
+ })
+ .ne([TokenKind::OpenBrace, TokenKind::CloseBrace].iter().copied()) =>
+ {
+ kind
+ },
+ _ => &ExprKind::Tup(&[]),
+ },
+ ([], Some(expr)) => match expr.kind {
+ // `{ return .. }` => `return ..`
+ ExprKind::Ret(..) => &expr.kind,
+ _ => kind,
+ },
+ ([stmt], None) => match stmt.kind {
+ StmtKind::Expr(expr) | StmtKind::Semi(expr) => match expr.kind {
+ // `{ return ..; }` => `return ..`
+ ExprKind::Ret(..) => &expr.kind,
+ _ => kind,
+ },
+ _ => kind,
+ },
+ _ => kind,
+ }
+ } else {
+ kind
+ }
+}
+
+fn swap_binop<'a>(
+ binop: BinOpKind,
+ lhs: &'a Expr<'a>,
+ rhs: &'a Expr<'a>,
+) -> Option<(BinOpKind, &'a Expr<'a>, &'a Expr<'a>)> {
+ match binop {
+ BinOpKind::Add | BinOpKind::Eq | BinOpKind::Ne | BinOpKind::BitAnd | BinOpKind::BitXor | BinOpKind::BitOr => {
+ Some((binop, rhs, lhs))
+ },
+ BinOpKind::Lt => Some((BinOpKind::Gt, rhs, lhs)),
+ BinOpKind::Le => Some((BinOpKind::Ge, rhs, lhs)),
+ BinOpKind::Ge => Some((BinOpKind::Le, rhs, lhs)),
+ BinOpKind::Gt => Some((BinOpKind::Lt, rhs, lhs)),
+ BinOpKind::Mul // Not always commutative, e.g. with matrices. See issue #5698
+ | BinOpKind::Shl
+ | BinOpKind::Shr
+ | BinOpKind::Rem
+ | BinOpKind::Sub
+ | BinOpKind::Div
+ | BinOpKind::And
+ | BinOpKind::Or => None,
+ }
+}
+
+/// Checks if the two `Option`s are both `None` or some equal values as per
+/// `eq_fn`.
+pub fn both<X>(l: &Option<X>, r: &Option<X>, mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
+ l.as_ref()
+ .map_or_else(|| r.is_none(), |x| r.as_ref().map_or(false, |y| eq_fn(x, y)))
+}
+
+/// Checks if two slices are equal as per `eq_fn`.
+pub fn over<X>(left: &[X], right: &[X], mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
+ left.len() == right.len() && left.iter().zip(right).all(|(x, y)| eq_fn(x, y))
+}
+
+/// Counts how many elements of the slices are equal as per `eq_fn`.
+pub fn count_eq<X: Sized>(
+ left: &mut dyn Iterator<Item = X>,
+ right: &mut dyn Iterator<Item = X>,
+ mut eq_fn: impl FnMut(&X, &X) -> bool,
+) -> usize {
+ left.zip(right).take_while(|(l, r)| eq_fn(l, r)).count()
+}
+
+/// Checks if two expressions evaluate to the same value, and don't contain any side effects.
+pub fn eq_expr_value(cx: &LateContext<'_>, left: &Expr<'_>, right: &Expr<'_>) -> bool {
+ SpanlessEq::new(cx).deny_side_effects().eq_expr(left, right)
+}
+
+/// Type used to hash an ast element. This is different from the `Hash` trait
+/// on ast types as this
+/// trait would consider IDs and spans.
+///
+/// All expressions kind are hashed, but some might have a weaker hash.
+pub struct SpanlessHash<'a, 'tcx> {
+ /// Context used to evaluate constant expressions.
+ cx: &'a LateContext<'tcx>,
+ maybe_typeck_results: Option<&'tcx TypeckResults<'tcx>>,
+ s: FxHasher,
+}
+
+impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
+ pub fn new(cx: &'a LateContext<'tcx>) -> Self {
+ Self {
+ cx,
+ maybe_typeck_results: cx.maybe_typeck_results(),
+ s: FxHasher::default(),
+ }
+ }
+
+ pub fn finish(self) -> u64 {
+ self.s.finish()
+ }
+
+ pub fn hash_block(&mut self, b: &Block<'_>) {
+ for s in b.stmts {
+ self.hash_stmt(s);
+ }
+
+ if let Some(e) = b.expr {
+ self.hash_expr(e);
+ }
+
+ std::mem::discriminant(&b.rules).hash(&mut self.s);
+ }
+
+ #[expect(clippy::too_many_lines)]
+ pub fn hash_expr(&mut self, e: &Expr<'_>) {
+ let simple_const = self
+ .maybe_typeck_results
+ .and_then(|typeck_results| constant_simple(self.cx, typeck_results, e));
+
+ // const hashing may result in the same hash as some unrelated node, so add a sort of
+ // discriminant depending on which path we're choosing next
+ simple_const.hash(&mut self.s);
+ if simple_const.is_some() {
+ return;
+ }
+
+ std::mem::discriminant(&e.kind).hash(&mut self.s);
+
+ match e.kind {
+ ExprKind::AddrOf(kind, m, e) => {
+ std::mem::discriminant(&kind).hash(&mut self.s);
+ m.hash(&mut self.s);
+ self.hash_expr(e);
+ },
+ ExprKind::Continue(i) => {
+ if let Some(i) = i.label {
+ self.hash_name(i.ident.name);
+ }
+ },
+ ExprKind::Assign(l, r, _) => {
+ self.hash_expr(l);
+ self.hash_expr(r);
+ },
+ ExprKind::AssignOp(ref o, l, r) => {
+ std::mem::discriminant(&o.node).hash(&mut self.s);
+ self.hash_expr(l);
+ self.hash_expr(r);
+ },
+ ExprKind::Block(b, _) => {
+ self.hash_block(b);
+ },
+ ExprKind::Binary(op, l, r) => {
+ std::mem::discriminant(&op.node).hash(&mut self.s);
+ self.hash_expr(l);
+ self.hash_expr(r);
+ },
+ ExprKind::Break(i, ref j) => {
+ if let Some(i) = i.label {
+ self.hash_name(i.ident.name);
+ }
+ if let Some(j) = *j {
++ self.hash_expr(j);
+ }
+ },
+ ExprKind::Box(e) | ExprKind::DropTemps(e) | ExprKind::Yield(e, _) => {
+ self.hash_expr(e);
+ },
+ ExprKind::Call(fun, args) => {
+ self.hash_expr(fun);
+ self.hash_exprs(args);
+ },
+ ExprKind::Cast(e, ty) | ExprKind::Type(e, ty) => {
+ self.hash_expr(e);
+ self.hash_ty(ty);
+ },
+ ExprKind::Closure(cap, _, eid, _, _) => {
+ std::mem::discriminant(&cap).hash(&mut self.s);
+ // closures inherit TypeckResults
+ self.hash_expr(&self.cx.tcx.hir().body(eid).value);
+ },
+ ExprKind::Field(e, ref f) => {
+ self.hash_expr(e);
+ self.hash_name(f.name);
+ },
+ ExprKind::Index(a, i) => {
+ self.hash_expr(a);
+ self.hash_expr(i);
+ },
+ ExprKind::InlineAsm(asm) => {
+ for piece in asm.template {
+ match piece {
+ InlineAsmTemplatePiece::String(s) => s.hash(&mut self.s),
+ InlineAsmTemplatePiece::Placeholder {
+ operand_idx,
+ modifier,
+ span: _,
+ } => {
+ operand_idx.hash(&mut self.s);
+ modifier.hash(&mut self.s);
+ },
+ }
+ }
+ asm.options.hash(&mut self.s);
+ for (op, _op_sp) in asm.operands {
+ match op {
+ InlineAsmOperand::In { reg, expr } => {
+ reg.hash(&mut self.s);
+ self.hash_expr(expr);
+ },
+ InlineAsmOperand::Out { reg, late, expr } => {
+ reg.hash(&mut self.s);
+ late.hash(&mut self.s);
+ if let Some(expr) = expr {
+ self.hash_expr(expr);
+ }
+ },
+ InlineAsmOperand::InOut { reg, late, expr } => {
+ reg.hash(&mut self.s);
+ late.hash(&mut self.s);
+ self.hash_expr(expr);
+ },
+ InlineAsmOperand::SplitInOut {
+ reg,
+ late,
+ in_expr,
+ out_expr,
+ } => {
+ reg.hash(&mut self.s);
+ late.hash(&mut self.s);
+ self.hash_expr(in_expr);
+ if let Some(out_expr) = out_expr {
+ self.hash_expr(out_expr);
+ }
+ },
+ InlineAsmOperand::Const { anon_const } | InlineAsmOperand::SymFn { anon_const } => {
+ self.hash_body(anon_const.body);
+ },
+ InlineAsmOperand::SymStatic { path, def_id: _ } => self.hash_qpath(path),
+ }
+ }
+ },
+ ExprKind::Let(Let { pat, init, ty, .. }) => {
+ self.hash_expr(init);
+ if let Some(ty) = ty {
+ self.hash_ty(ty);
+ }
+ self.hash_pat(pat);
+ },
+ ExprKind::Err => {},
+ ExprKind::Lit(ref l) => {
+ l.node.hash(&mut self.s);
+ },
+ ExprKind::Loop(b, ref i, ..) => {
+ self.hash_block(b);
+ if let Some(i) = *i {
+ self.hash_name(i.ident.name);
+ }
+ },
+ ExprKind::If(cond, then, ref else_opt) => {
+ self.hash_expr(cond);
+ self.hash_expr(then);
+ if let Some(e) = *else_opt {
+ self.hash_expr(e);
+ }
+ },
+ ExprKind::Match(e, arms, ref s) => {
+ self.hash_expr(e);
+
+ for arm in arms {
+ self.hash_pat(arm.pat);
+ if let Some(ref e) = arm.guard {
+ self.hash_guard(e);
+ }
+ self.hash_expr(arm.body);
+ }
+
+ s.hash(&mut self.s);
+ },
+ ExprKind::MethodCall(path, args, ref _fn_span) => {
+ self.hash_name(path.ident.name);
+ self.hash_exprs(args);
+ },
+ ExprKind::ConstBlock(ref l_id) => {
+ self.hash_body(l_id.body);
+ },
+ ExprKind::Repeat(e, len) => {
+ self.hash_expr(e);
+ self.hash_array_length(len);
+ },
+ ExprKind::Ret(ref e) => {
+ if let Some(e) = *e {
+ self.hash_expr(e);
+ }
+ },
+ ExprKind::Path(ref qpath) => {
+ self.hash_qpath(qpath);
+ },
+ ExprKind::Struct(path, fields, ref expr) => {
+ self.hash_qpath(path);
+
+ for f in fields {
+ self.hash_name(f.ident.name);
+ self.hash_expr(f.expr);
+ }
+
+ if let Some(e) = *expr {
+ self.hash_expr(e);
+ }
+ },
+ ExprKind::Tup(tup) => {
+ self.hash_exprs(tup);
+ },
+ ExprKind::Array(v) => {
+ self.hash_exprs(v);
+ },
+ ExprKind::Unary(lop, le) => {
+ std::mem::discriminant(&lop).hash(&mut self.s);
+ self.hash_expr(le);
+ },
+ }
+ }
+
+ pub fn hash_exprs(&mut self, e: &[Expr<'_>]) {
+ for e in e {
+ self.hash_expr(e);
+ }
+ }
+
+ pub fn hash_name(&mut self, n: Symbol) {
+ n.hash(&mut self.s);
+ }
+
+ pub fn hash_qpath(&mut self, p: &QPath<'_>) {
+ match *p {
+ QPath::Resolved(_, path) => {
+ self.hash_path(path);
+ },
+ QPath::TypeRelative(_, path) => {
+ self.hash_name(path.ident.name);
+ },
+ QPath::LangItem(lang_item, ..) => {
+ std::mem::discriminant(&lang_item).hash(&mut self.s);
+ },
+ }
+ // self.maybe_typeck_results.unwrap().qpath_res(p, id).hash(&mut self.s);
+ }
+
+ pub fn hash_pat(&mut self, pat: &Pat<'_>) {
+ std::mem::discriminant(&pat.kind).hash(&mut self.s);
+ match pat.kind {
+ PatKind::Binding(ann, _, _, pat) => {
+ std::mem::discriminant(&ann).hash(&mut self.s);
+ if let Some(pat) = pat {
+ self.hash_pat(pat);
+ }
+ },
+ PatKind::Box(pat) => self.hash_pat(pat),
+ PatKind::Lit(expr) => self.hash_expr(expr),
+ PatKind::Or(pats) => {
+ for pat in pats {
+ self.hash_pat(pat);
+ }
+ },
+ PatKind::Path(ref qpath) => self.hash_qpath(qpath),
+ PatKind::Range(s, e, i) => {
+ if let Some(s) = s {
+ self.hash_expr(s);
+ }
+ if let Some(e) = e {
+ self.hash_expr(e);
+ }
+ std::mem::discriminant(&i).hash(&mut self.s);
+ },
+ PatKind::Ref(pat, mu) => {
+ self.hash_pat(pat);
+ std::mem::discriminant(&mu).hash(&mut self.s);
+ },
+ PatKind::Slice(l, m, r) => {
+ for pat in l {
+ self.hash_pat(pat);
+ }
+ if let Some(pat) = m {
+ self.hash_pat(pat);
+ }
+ for pat in r {
+ self.hash_pat(pat);
+ }
+ },
+ PatKind::Struct(ref qpath, fields, e) => {
+ self.hash_qpath(qpath);
+ for f in fields {
+ self.hash_name(f.ident.name);
+ self.hash_pat(f.pat);
+ }
+ e.hash(&mut self.s);
+ },
+ PatKind::Tuple(pats, e) => {
+ for pat in pats {
+ self.hash_pat(pat);
+ }
+ e.hash(&mut self.s);
+ },
+ PatKind::TupleStruct(ref qpath, pats, e) => {
+ self.hash_qpath(qpath);
+ for pat in pats {
+ self.hash_pat(pat);
+ }
+ e.hash(&mut self.s);
+ },
+ PatKind::Wild => {},
+ }
+ }
+
+ pub fn hash_path(&mut self, path: &Path<'_>) {
+ match path.res {
+ // constant hash since equality is dependant on inter-expression context
+ // e.g. The expressions `if let Some(x) = foo() {}` and `if let Some(y) = foo() {}` are considered equal
+ // even though the binding names are different and they have different `HirId`s.
+ Res::Local(_) => 1_usize.hash(&mut self.s),
+ _ => {
+ for seg in path.segments {
+ self.hash_name(seg.ident.name);
+ self.hash_generic_args(seg.args().args);
+ }
+ },
+ }
+ }
+
+ pub fn hash_stmt(&mut self, b: &Stmt<'_>) {
+ std::mem::discriminant(&b.kind).hash(&mut self.s);
+
+ match &b.kind {
+ StmtKind::Local(local) => {
+ self.hash_pat(local.pat);
+ if let Some(init) = local.init {
+ self.hash_expr(init);
+ }
+ },
+ StmtKind::Item(..) => {},
+ StmtKind::Expr(expr) | StmtKind::Semi(expr) => {
+ self.hash_expr(expr);
+ },
+ }
+ }
+
+ pub fn hash_guard(&mut self, g: &Guard<'_>) {
+ match g {
+ Guard::If(expr) | Guard::IfLet(Let { init: expr, .. }) => {
+ self.hash_expr(expr);
+ },
+ }
+ }
+
+ pub fn hash_lifetime(&mut self, lifetime: Lifetime) {
+ std::mem::discriminant(&lifetime.name).hash(&mut self.s);
+ if let LifetimeName::Param(param_id, ref name) = lifetime.name {
+ std::mem::discriminant(name).hash(&mut self.s);
+ param_id.hash(&mut self.s);
+ match name {
+ ParamName::Plain(ref ident) => {
+ ident.name.hash(&mut self.s);
+ },
+ ParamName::Fresh | ParamName::Error => {},
+ }
+ }
+ }
+
+ pub fn hash_ty(&mut self, ty: &Ty<'_>) {
+ std::mem::discriminant(&ty.kind).hash(&mut self.s);
+ self.hash_tykind(&ty.kind);
+ }
+
+ pub fn hash_tykind(&mut self, ty: &TyKind<'_>) {
+ match ty {
+ TyKind::Slice(ty) => {
+ self.hash_ty(ty);
+ },
+ &TyKind::Array(ty, len) => {
+ self.hash_ty(ty);
+ self.hash_array_length(len);
+ },
+ TyKind::Ptr(ref mut_ty) => {
+ self.hash_ty(mut_ty.ty);
+ mut_ty.mutbl.hash(&mut self.s);
+ },
+ TyKind::Rptr(lifetime, ref mut_ty) => {
+ self.hash_lifetime(*lifetime);
+ self.hash_ty(mut_ty.ty);
+ mut_ty.mutbl.hash(&mut self.s);
+ },
+ TyKind::BareFn(bfn) => {
+ bfn.unsafety.hash(&mut self.s);
+ bfn.abi.hash(&mut self.s);
+ for arg in bfn.decl.inputs {
+ self.hash_ty(arg);
+ }
+ std::mem::discriminant(&bfn.decl.output).hash(&mut self.s);
+ match bfn.decl.output {
+ FnRetTy::DefaultReturn(_) => {},
+ FnRetTy::Return(ty) => {
+ self.hash_ty(ty);
+ },
+ }
+ bfn.decl.c_variadic.hash(&mut self.s);
+ },
+ TyKind::Tup(ty_list) => {
+ for ty in *ty_list {
+ self.hash_ty(ty);
+ }
+ },
+ TyKind::Path(ref qpath) => self.hash_qpath(qpath),
+ TyKind::OpaqueDef(_, arg_list) => {
+ self.hash_generic_args(arg_list);
+ },
+ TyKind::TraitObject(_, lifetime, _) => {
+ self.hash_lifetime(*lifetime);
+ },
+ TyKind::Typeof(anon_const) => {
+ self.hash_body(anon_const.body);
+ },
+ TyKind::Err | TyKind::Infer | TyKind::Never => {},
+ }
+ }
+
+ pub fn hash_array_length(&mut self, length: ArrayLen) {
+ match length {
+ ArrayLen::Infer(..) => {},
+ ArrayLen::Body(anon_const) => self.hash_body(anon_const.body),
+ }
+ }
+
+ pub fn hash_body(&mut self, body_id: BodyId) {
+ // swap out TypeckResults when hashing a body
+ let old_maybe_typeck_results = self.maybe_typeck_results.replace(self.cx.tcx.typeck_body(body_id));
+ self.hash_expr(&self.cx.tcx.hir().body(body_id).value);
+ self.maybe_typeck_results = old_maybe_typeck_results;
+ }
+
+ fn hash_generic_args(&mut self, arg_list: &[GenericArg<'_>]) {
+ for arg in arg_list {
+ match *arg {
+ GenericArg::Lifetime(l) => self.hash_lifetime(l),
+ GenericArg::Type(ref ty) => self.hash_ty(ty),
+ GenericArg::Const(ref ca) => self.hash_body(ca.value.body),
+ GenericArg::Infer(ref inf) => self.hash_ty(&inf.to_ty()),
+ }
+ }
+ }
+}
--- /dev/null
- is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, fields.iter().map(|field| &*field.pat))
+#![feature(box_patterns)]
+#![feature(control_flow_enum)]
+#![feature(let_else)]
+#![feature(let_chains)]
+#![feature(lint_reasons)]
+#![feature(once_cell)]
+#![feature(rustc_private)]
+#![recursion_limit = "512"]
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+#![allow(clippy::missing_errors_doc, clippy::missing_panics_doc, clippy::must_use_candidate)]
+// warn on the same lints as `clippy_lints`
+#![warn(trivial_casts, trivial_numeric_casts)]
+// warn on lints, that are included in `rust-lang/rust`s bootstrap
+#![warn(rust_2018_idioms, unused_lifetimes)]
+// warn on rustc internal lints
+#![warn(rustc::internal)]
+
+// FIXME: switch to something more ergonomic here, once available.
+// (Currently there is no way to opt into sysroot crates without `extern crate`.)
+extern crate rustc_ast;
+extern crate rustc_ast_pretty;
+extern crate rustc_attr;
+extern crate rustc_data_structures;
+extern crate rustc_errors;
+extern crate rustc_hir;
+extern crate rustc_infer;
+extern crate rustc_lexer;
+extern crate rustc_lint;
+extern crate rustc_middle;
+extern crate rustc_session;
+extern crate rustc_span;
+extern crate rustc_target;
+extern crate rustc_trait_selection;
+extern crate rustc_typeck;
+
+#[macro_use]
+pub mod sym_helper;
+
+pub mod ast_utils;
+pub mod attrs;
+pub mod comparisons;
+pub mod consts;
+pub mod diagnostics;
+pub mod eager_or_lazy;
+pub mod higher;
+mod hir_utils;
+pub mod macros;
+pub mod msrvs;
+pub mod numeric_literal;
+pub mod paths;
+pub mod ptr;
+pub mod qualify_min_const_fn;
+pub mod source;
+pub mod str_utils;
+pub mod sugg;
+pub mod ty;
+pub mod usage;
+pub mod visitors;
+
+pub use self::attrs::*;
+pub use self::hir_utils::{both, count_eq, eq_expr_value, over, SpanlessEq, SpanlessHash};
+
+use std::collections::hash_map::Entry;
+use std::hash::BuildHasherDefault;
+use std::lazy::SyncOnceCell;
+use std::sync::{Mutex, MutexGuard};
+
+use if_chain::if_chain;
+use rustc_ast::ast::{self, LitKind};
+use rustc_ast::Attribute;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::unhash::UnhashMap;
+use rustc_hir as hir;
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, CRATE_DEF_ID};
+use rustc_hir::hir_id::{HirIdMap, HirIdSet};
+use rustc_hir::intravisit::{walk_expr, FnKind, Visitor};
+use rustc_hir::LangItem::{OptionNone, ResultErr, ResultOk};
+use rustc_hir::{
+ def, Arm, ArrayLen, BindingAnnotation, Block, BlockCheckMode, Body, Constness, Destination, Expr, ExprKind, FnDecl,
+ HirId, Impl, ImplItem, ImplItemKind, IsAsync, Item, ItemKind, LangItem, Local, MatchSource, Mutability, Node,
+ Param, Pat, PatKind, Path, PathSegment, PrimTy, QPath, Stmt, StmtKind, TraitItem, TraitItemKind, TraitRef, TyKind,
+ UnOp,
+};
+use rustc_lint::{LateContext, Level, Lint, LintContext};
+use rustc_middle::hir::place::PlaceBase;
+use rustc_middle::ty as rustc_ty;
+use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow};
+use rustc_middle::ty::binding::BindingMode;
+use rustc_middle::ty::fast_reject::SimplifiedTypeGen::{
+ ArraySimplifiedType, BoolSimplifiedType, CharSimplifiedType, FloatSimplifiedType, IntSimplifiedType,
+ PtrSimplifiedType, SliceSimplifiedType, StrSimplifiedType, UintSimplifiedType,
+};
+use rustc_middle::ty::{layout::IntegerExt, BorrowKind, DefIdTree, Ty, TyCtxt, TypeAndMut, TypeFoldable, UpvarCapture};
+use rustc_middle::ty::{FloatTy, IntTy, UintTy};
+use rustc_semver::RustcVersion;
+use rustc_session::Session;
+use rustc_span::hygiene::{ExpnKind, MacroKind};
+use rustc_span::source_map::original_sp;
+use rustc_span::sym;
+use rustc_span::symbol::{kw, Symbol};
+use rustc_span::{Span, DUMMY_SP};
+use rustc_target::abi::Integer;
+
+use crate::consts::{constant, Constant};
+use crate::ty::{can_partially_move_ty, is_copy, is_recursively_primitive_type};
+use crate::visitors::expr_visitor_no_bodies;
+
+pub fn parse_msrv(msrv: &str, sess: Option<&Session>, span: Option<Span>) -> Option<RustcVersion> {
+ if let Ok(version) = RustcVersion::parse(msrv) {
+ return Some(version);
+ } else if let Some(sess) = sess {
+ if let Some(span) = span {
+ sess.span_err(span, &format!("`{}` is not a valid Rust version", msrv));
+ }
+ }
+ None
+}
+
+pub fn meets_msrv(msrv: Option<RustcVersion>, lint_msrv: RustcVersion) -> bool {
+ msrv.map_or(true, |msrv| msrv.meets(lint_msrv))
+}
+
+#[macro_export]
+macro_rules! extract_msrv_attr {
+ ($context:ident) => {
+ fn enter_lint_attrs(&mut self, cx: &rustc_lint::$context<'_>, attrs: &[rustc_ast::ast::Attribute]) {
+ let sess = rustc_lint::LintContext::sess(cx);
+ match $crate::get_unique_inner_attr(sess, attrs, "msrv") {
+ Some(msrv_attr) => {
+ if let Some(msrv) = msrv_attr.value_str() {
+ self.msrv = $crate::parse_msrv(&msrv.to_string(), Some(sess), Some(msrv_attr.span));
+ } else {
+ sess.span_err(msrv_attr.span, "bad clippy attribute");
+ }
+ },
+ _ => (),
+ }
+ }
+ };
+}
+
+/// If the given expression is a local binding, find the initializer expression.
+/// If that initializer expression is another local binding, find its initializer again.
+/// This process repeats as long as possible (but usually no more than once). Initializer
+/// expressions with adjustments are ignored. If this is not desired, use [`find_binding_init`]
+/// instead.
+///
+/// Examples:
+/// ```
+/// let abc = 1;
+/// // ^ output
+/// let def = abc;
+/// dbg!(def);
+/// // ^^^ input
+///
+/// // or...
+/// let abc = 1;
+/// let def = abc + 2;
+/// // ^^^^^^^ output
+/// dbg!(def);
+/// // ^^^ input
+/// ```
+pub fn expr_or_init<'a, 'b, 'tcx: 'b>(cx: &LateContext<'tcx>, mut expr: &'a Expr<'b>) -> &'a Expr<'b> {
+ while let Some(init) = path_to_local(expr)
+ .and_then(|id| find_binding_init(cx, id))
+ .filter(|init| cx.typeck_results().expr_adjustments(init).is_empty())
+ {
+ expr = init;
+ }
+ expr
+}
+
+/// Finds the initializer expression for a local binding. Returns `None` if the binding is mutable.
+/// By only considering immutable bindings, we guarantee that the returned expression represents the
+/// value of the binding wherever it is referenced.
+///
+/// Example: For `let x = 1`, if the `HirId` of `x` is provided, the `Expr` `1` is returned.
+/// Note: If you have an expression that references a binding `x`, use `path_to_local` to get the
+/// canonical binding `HirId`.
+pub fn find_binding_init<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<&'tcx Expr<'tcx>> {
+ let hir = cx.tcx.hir();
+ if_chain! {
+ if let Some(Node::Binding(pat)) = hir.find(hir_id);
+ if matches!(pat.kind, PatKind::Binding(BindingAnnotation::Unannotated, ..));
+ let parent = hir.get_parent_node(hir_id);
+ if let Some(Node::Local(local)) = hir.find(parent);
+ then {
+ return local.init;
+ }
+ }
+ None
+}
+
+/// Returns `true` if the given `NodeId` is inside a constant context
+///
+/// # Example
+///
+/// ```rust,ignore
+/// if in_constant(cx, expr.hir_id) {
+/// // Do something
+/// }
+/// ```
+pub fn in_constant(cx: &LateContext<'_>, id: HirId) -> bool {
+ let parent_id = cx.tcx.hir().get_parent_item(id);
+ match cx.tcx.hir().get_by_def_id(parent_id) {
+ Node::Item(&Item {
+ kind: ItemKind::Const(..) | ItemKind::Static(..),
+ ..
+ })
+ | Node::TraitItem(&TraitItem {
+ kind: TraitItemKind::Const(..),
+ ..
+ })
+ | Node::ImplItem(&ImplItem {
+ kind: ImplItemKind::Const(..),
+ ..
+ })
+ | Node::AnonConst(_) => true,
+ Node::Item(&Item {
+ kind: ItemKind::Fn(ref sig, ..),
+ ..
+ })
+ | Node::ImplItem(&ImplItem {
+ kind: ImplItemKind::Fn(ref sig, _),
+ ..
+ }) => sig.header.constness == Constness::Const,
+ _ => false,
+ }
+}
+
+/// Checks if a `QPath` resolves to a constructor of a `LangItem`.
+/// For example, use this to check whether a function call or a pattern is `Some(..)`.
+pub fn is_lang_ctor(cx: &LateContext<'_>, qpath: &QPath<'_>, lang_item: LangItem) -> bool {
+ if let QPath::Resolved(_, path) = qpath {
+ if let Res::Def(DefKind::Ctor(..), ctor_id) = path.res {
+ if let Ok(item_id) = cx.tcx.lang_items().require(lang_item) {
+ return cx.tcx.parent(ctor_id) == item_id;
+ }
+ }
+ }
+ false
+}
+
+pub fn is_unit_expr(expr: &Expr<'_>) -> bool {
+ matches!(
+ expr.kind,
+ ExprKind::Block(
+ Block {
+ stmts: [],
+ expr: None,
+ ..
+ },
+ _
+ ) | ExprKind::Tup([])
+ )
+}
+
+/// Checks if given pattern is a wildcard (`_`)
+pub fn is_wild(pat: &Pat<'_>) -> bool {
+ matches!(pat.kind, PatKind::Wild)
+}
+
+/// Checks if the method call given in `expr` belongs to the given trait.
+/// This is a deprecated function, consider using [`is_trait_method`].
+pub fn match_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, path: &[&str]) -> bool {
+ let def_id = cx.typeck_results().type_dependent_def_id(expr.hir_id).unwrap();
+ let trt_id = cx.tcx.trait_of_item(def_id);
+ trt_id.map_or(false, |trt_id| match_def_path(cx, trt_id, path))
+}
+
+/// Checks if a method is defined in an impl of a diagnostic item
+pub fn is_diag_item_method(cx: &LateContext<'_>, def_id: DefId, diag_item: Symbol) -> bool {
+ if let Some(impl_did) = cx.tcx.impl_of_method(def_id) {
+ if let Some(adt) = cx.tcx.type_of(impl_did).ty_adt_def() {
+ return cx.tcx.is_diagnostic_item(diag_item, adt.did());
+ }
+ }
+ false
+}
+
+/// Checks if a method is in a diagnostic item trait
+pub fn is_diag_trait_item(cx: &LateContext<'_>, def_id: DefId, diag_item: Symbol) -> bool {
+ if let Some(trait_did) = cx.tcx.trait_of_item(def_id) {
+ return cx.tcx.is_diagnostic_item(diag_item, trait_did);
+ }
+ false
+}
+
+/// Checks if the method call given in `expr` belongs to the given trait.
+pub fn is_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, diag_item: Symbol) -> bool {
+ cx.typeck_results()
+ .type_dependent_def_id(expr.hir_id)
+ .map_or(false, |did| is_diag_trait_item(cx, did, diag_item))
+}
+
+/// Checks if the given expression is a path referring an item on the trait
+/// that is marked with the given diagnostic item.
+///
+/// For checking method call expressions instead of path expressions, use
+/// [`is_trait_method`].
+///
+/// For example, this can be used to find if an expression like `u64::default`
+/// refers to an item of the trait `Default`, which is associated with the
+/// `diag_item` of `sym::Default`.
+pub fn is_trait_item(cx: &LateContext<'_>, expr: &Expr<'_>, diag_item: Symbol) -> bool {
+ if let hir::ExprKind::Path(ref qpath) = expr.kind {
+ cx.qpath_res(qpath, expr.hir_id)
+ .opt_def_id()
+ .map_or(false, |def_id| is_diag_trait_item(cx, def_id, diag_item))
+ } else {
+ false
+ }
+}
+
+pub fn last_path_segment<'tcx>(path: &QPath<'tcx>) -> &'tcx PathSegment<'tcx> {
+ match *path {
+ QPath::Resolved(_, path) => path.segments.last().expect("A path must have at least one segment"),
+ QPath::TypeRelative(_, seg) => seg,
+ QPath::LangItem(..) => panic!("last_path_segment: lang item has no path segments"),
+ }
+}
+
+pub fn qpath_generic_tys<'tcx>(qpath: &QPath<'tcx>) -> impl Iterator<Item = &'tcx hir::Ty<'tcx>> {
+ last_path_segment(qpath)
+ .args
+ .map_or(&[][..], |a| a.args)
+ .iter()
+ .filter_map(|a| match a {
+ hir::GenericArg::Type(ty) => Some(ty),
+ _ => None,
+ })
+}
+
+/// THIS METHOD IS DEPRECATED and will eventually be removed since it does not match against the
+/// entire path or resolved `DefId`. Prefer using `match_def_path`. Consider getting a `DefId` from
+/// `QPath::Resolved.1.res.opt_def_id()`.
+///
+/// Matches a `QPath` against a slice of segment string literals.
+///
+/// There is also `match_path` if you are dealing with a `rustc_hir::Path` instead of a
+/// `rustc_hir::QPath`.
+///
+/// # Examples
+/// ```rust,ignore
+/// match_qpath(path, &["std", "rt", "begin_unwind"])
+/// ```
+pub fn match_qpath(path: &QPath<'_>, segments: &[&str]) -> bool {
+ match *path {
+ QPath::Resolved(_, path) => match_path(path, segments),
+ QPath::TypeRelative(ty, segment) => match ty.kind {
+ TyKind::Path(ref inner_path) => {
+ if let [prefix @ .., end] = segments {
+ if match_qpath(inner_path, prefix) {
+ return segment.ident.name.as_str() == *end;
+ }
+ }
+ false
+ },
+ _ => false,
+ },
+ QPath::LangItem(..) => false,
+ }
+}
+
+/// If the expression is a path, resolves it to a `DefId` and checks if it matches the given path.
+///
+/// Please use `is_expr_diagnostic_item` if the target is a diagnostic item.
+pub fn is_expr_path_def_path(cx: &LateContext<'_>, expr: &Expr<'_>, segments: &[&str]) -> bool {
+ path_def_id(cx, expr).map_or(false, |id| match_def_path(cx, id, segments))
+}
+
+/// If the expression is a path, resolves it to a `DefId` and checks if it matches the given
+/// diagnostic item.
+pub fn is_expr_diagnostic_item(cx: &LateContext<'_>, expr: &Expr<'_>, diag_item: Symbol) -> bool {
+ path_def_id(cx, expr).map_or(false, |id| cx.tcx.is_diagnostic_item(diag_item, id))
+}
+
+/// THIS METHOD IS DEPRECATED and will eventually be removed since it does not match against the
+/// entire path or resolved `DefId`. Prefer using `match_def_path`. Consider getting a `DefId` from
+/// `QPath::Resolved.1.res.opt_def_id()`.
+///
+/// Matches a `Path` against a slice of segment string literals.
+///
+/// There is also `match_qpath` if you are dealing with a `rustc_hir::QPath` instead of a
+/// `rustc_hir::Path`.
+///
+/// # Examples
+///
+/// ```rust,ignore
+/// if match_path(&trait_ref.path, &paths::HASH) {
+/// // This is the `std::hash::Hash` trait.
+/// }
+///
+/// if match_path(ty_path, &["rustc", "lint", "Lint"]) {
+/// // This is a `rustc_middle::lint::Lint`.
+/// }
+/// ```
+pub fn match_path(path: &Path<'_>, segments: &[&str]) -> bool {
+ path.segments
+ .iter()
+ .rev()
+ .zip(segments.iter().rev())
+ .all(|(a, b)| a.ident.name.as_str() == *b)
+}
+
+/// If the expression is a path to a local, returns the canonical `HirId` of the local.
+pub fn path_to_local(expr: &Expr<'_>) -> Option<HirId> {
+ if let ExprKind::Path(QPath::Resolved(None, path)) = expr.kind {
+ if let Res::Local(id) = path.res {
+ return Some(id);
+ }
+ }
+ None
+}
+
+/// Returns true if the expression is a path to a local with the specified `HirId`.
+/// Use this function to see if an expression matches a function argument or a match binding.
+pub fn path_to_local_id(expr: &Expr<'_>, id: HirId) -> bool {
+ path_to_local(expr) == Some(id)
+}
+
+pub trait MaybePath<'hir> {
+ fn hir_id(&self) -> HirId;
+ fn qpath_opt(&self) -> Option<&QPath<'hir>>;
+}
+
+macro_rules! maybe_path {
+ ($ty:ident, $kind:ident) => {
+ impl<'hir> MaybePath<'hir> for hir::$ty<'hir> {
+ fn hir_id(&self) -> HirId {
+ self.hir_id
+ }
+ fn qpath_opt(&self) -> Option<&QPath<'hir>> {
+ match &self.kind {
+ hir::$kind::Path(qpath) => Some(qpath),
+ _ => None,
+ }
+ }
+ }
+ };
+}
+maybe_path!(Expr, ExprKind);
+maybe_path!(Pat, PatKind);
+maybe_path!(Ty, TyKind);
+
+/// If `maybe_path` is a path node, resolves it, otherwise returns `Res::Err`
+pub fn path_res<'tcx>(cx: &LateContext<'_>, maybe_path: &impl MaybePath<'tcx>) -> Res {
+ match maybe_path.qpath_opt() {
+ None => Res::Err,
+ Some(qpath) => cx.qpath_res(qpath, maybe_path.hir_id()),
+ }
+}
+
+/// If `maybe_path` is a path node which resolves to an item, retrieves the item ID
+pub fn path_def_id<'tcx>(cx: &LateContext<'_>, maybe_path: &impl MaybePath<'tcx>) -> Option<DefId> {
+ path_res(cx, maybe_path).opt_def_id()
+}
+
+/// Resolves a def path like `std::vec::Vec`.
+/// This function is expensive and should be used sparingly.
+pub fn def_path_res(cx: &LateContext<'_>, path: &[&str]) -> Res {
+ fn item_child_by_name(tcx: TyCtxt<'_>, def_id: DefId, name: &str) -> Option<Res> {
+ match tcx.def_kind(def_id) {
+ DefKind::Mod | DefKind::Enum | DefKind::Trait => tcx
+ .module_children(def_id)
+ .iter()
+ .find(|item| item.ident.name.as_str() == name)
+ .map(|child| child.res.expect_non_local()),
+ DefKind::Impl => tcx
+ .associated_item_def_ids(def_id)
+ .iter()
+ .copied()
+ .find(|assoc_def_id| tcx.item_name(*assoc_def_id).as_str() == name)
+ .map(|assoc_def_id| Res::Def(tcx.def_kind(assoc_def_id), assoc_def_id)),
+ _ => None,
+ }
+ }
+ fn find_primitive<'tcx>(tcx: TyCtxt<'tcx>, name: &str) -> impl Iterator<Item = DefId> + 'tcx {
+ let single = |ty| tcx.incoherent_impls(ty).iter().copied();
+ let empty = || [].iter().copied();
+ match name {
+ "bool" => single(BoolSimplifiedType),
+ "char" => single(CharSimplifiedType),
+ "str" => single(StrSimplifiedType),
+ "array" => single(ArraySimplifiedType),
+ "slice" => single(SliceSimplifiedType),
+ // FIXME: rustdoc documents these two using just `pointer`.
+ //
+ // Maybe this is something we should do here too.
+ "const_ptr" => single(PtrSimplifiedType(Mutability::Not)),
+ "mut_ptr" => single(PtrSimplifiedType(Mutability::Mut)),
+ "isize" => single(IntSimplifiedType(IntTy::Isize)),
+ "i8" => single(IntSimplifiedType(IntTy::I8)),
+ "i16" => single(IntSimplifiedType(IntTy::I16)),
+ "i32" => single(IntSimplifiedType(IntTy::I32)),
+ "i64" => single(IntSimplifiedType(IntTy::I64)),
+ "i128" => single(IntSimplifiedType(IntTy::I128)),
+ "usize" => single(UintSimplifiedType(UintTy::Usize)),
+ "u8" => single(UintSimplifiedType(UintTy::U8)),
+ "u16" => single(UintSimplifiedType(UintTy::U16)),
+ "u32" => single(UintSimplifiedType(UintTy::U32)),
+ "u64" => single(UintSimplifiedType(UintTy::U64)),
+ "u128" => single(UintSimplifiedType(UintTy::U128)),
+ "f32" => single(FloatSimplifiedType(FloatTy::F32)),
+ "f64" => single(FloatSimplifiedType(FloatTy::F64)),
+ _ => empty(),
+ }
+ }
+ fn find_crate(tcx: TyCtxt<'_>, name: &str) -> Option<DefId> {
+ tcx.crates(())
+ .iter()
+ .copied()
+ .find(|&num| tcx.crate_name(num).as_str() == name)
+ .map(CrateNum::as_def_id)
+ }
+
+ let (base, first, path) = match *path {
+ [base, first, ref path @ ..] => (base, first, path),
+ [primitive] => {
+ return PrimTy::from_name(Symbol::intern(primitive)).map_or(Res::Err, Res::PrimTy);
+ },
+ _ => return Res::Err,
+ };
+ let tcx = cx.tcx;
+ let starts = find_primitive(tcx, base)
+ .chain(find_crate(tcx, base))
+ .filter_map(|id| item_child_by_name(tcx, id, first));
+
+ for first in starts {
+ let last = path
+ .iter()
+ .copied()
+ // for each segment, find the child item
+ .try_fold(first, |res, segment| {
+ let def_id = res.def_id();
+ if let Some(item) = item_child_by_name(tcx, def_id, segment) {
+ Some(item)
+ } else if matches!(res, Res::Def(DefKind::Enum | DefKind::Struct, _)) {
+ // it is not a child item so check inherent impl items
+ tcx.inherent_impls(def_id)
+ .iter()
+ .find_map(|&impl_def_id| item_child_by_name(tcx, impl_def_id, segment))
+ } else {
+ None
+ }
+ });
+
+ if let Some(last) = last {
+ return last;
+ }
+ }
+
+ Res::Err
+}
+
+/// Convenience function to get the `DefId` of a trait by path.
+/// It could be a trait or trait alias.
+pub fn get_trait_def_id(cx: &LateContext<'_>, path: &[&str]) -> Option<DefId> {
+ match def_path_res(cx, path) {
+ Res::Def(DefKind::Trait | DefKind::TraitAlias, trait_id) => Some(trait_id),
+ _ => None,
+ }
+}
+
+/// Gets the `hir::TraitRef` of the trait the given method is implemented for.
+///
+/// Use this if you want to find the `TraitRef` of the `Add` trait in this example:
+///
+/// ```rust
+/// struct Point(isize, isize);
+///
+/// impl std::ops::Add for Point {
+/// type Output = Self;
+///
+/// fn add(self, other: Self) -> Self {
+/// Point(0, 0)
+/// }
+/// }
+/// ```
+pub fn trait_ref_of_method<'tcx>(cx: &LateContext<'tcx>, def_id: LocalDefId) -> Option<&'tcx TraitRef<'tcx>> {
+ // Get the implemented trait for the current function
+ let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
+ let parent_impl = cx.tcx.hir().get_parent_item(hir_id);
+ if_chain! {
+ if parent_impl != CRATE_DEF_ID;
+ if let hir::Node::Item(item) = cx.tcx.hir().get_by_def_id(parent_impl);
+ if let hir::ItemKind::Impl(impl_) = &item.kind;
+ then {
+ return impl_.of_trait.as_ref();
+ }
+ }
+ None
+}
+
+/// This method will return tuple of projection stack and root of the expression,
+/// used in `can_mut_borrow_both`.
+///
+/// For example, if `e` represents the `v[0].a.b[x]`
+/// this method will return a tuple, composed of a `Vec`
+/// containing the `Expr`s for `v[0], v[0].a, v[0].a.b, v[0].a.b[x]`
+/// and an `Expr` for root of them, `v`
+fn projection_stack<'a, 'hir>(mut e: &'a Expr<'hir>) -> (Vec<&'a Expr<'hir>>, &'a Expr<'hir>) {
+ let mut result = vec![];
+ let root = loop {
+ match e.kind {
+ ExprKind::Index(ep, _) | ExprKind::Field(ep, _) => {
+ result.push(e);
+ e = ep;
+ },
+ _ => break e,
+ };
+ };
+ result.reverse();
+ (result, root)
+}
+
+/// Gets the mutability of the custom deref adjustment, if any.
+pub fn expr_custom_deref_adjustment(cx: &LateContext<'_>, e: &Expr<'_>) -> Option<Mutability> {
+ cx.typeck_results()
+ .expr_adjustments(e)
+ .iter()
+ .find_map(|a| match a.kind {
+ Adjust::Deref(Some(d)) => Some(Some(d.mutbl)),
+ Adjust::Deref(None) => None,
+ _ => Some(None),
+ })
+ .and_then(|x| x)
+}
+
+/// Checks if two expressions can be mutably borrowed simultaneously
+/// and they aren't dependent on borrowing same thing twice
+pub fn can_mut_borrow_both(cx: &LateContext<'_>, e1: &Expr<'_>, e2: &Expr<'_>) -> bool {
+ let (s1, r1) = projection_stack(e1);
+ let (s2, r2) = projection_stack(e2);
+ if !eq_expr_value(cx, r1, r2) {
+ return true;
+ }
+ if expr_custom_deref_adjustment(cx, r1).is_some() || expr_custom_deref_adjustment(cx, r2).is_some() {
+ return false;
+ }
+
+ for (x1, x2) in s1.iter().zip(s2.iter()) {
+ if expr_custom_deref_adjustment(cx, x1).is_some() || expr_custom_deref_adjustment(cx, x2).is_some() {
+ return false;
+ }
+
+ match (&x1.kind, &x2.kind) {
+ (ExprKind::Field(_, i1), ExprKind::Field(_, i2)) => {
+ if i1 != i2 {
+ return true;
+ }
+ },
+ (ExprKind::Index(_, i1), ExprKind::Index(_, i2)) => {
+ if !eq_expr_value(cx, i1, i2) {
+ return false;
+ }
+ },
+ _ => return false,
+ }
+ }
+ false
+}
+
+/// Returns true if the `def_id` associated with the `path` is recognized as a "default-equivalent"
+/// constructor from the std library
+fn is_default_equivalent_ctor(cx: &LateContext<'_>, def_id: DefId, path: &QPath<'_>) -> bool {
+ let std_types_symbols = &[
+ sym::String,
+ sym::Vec,
+ sym::VecDeque,
+ sym::LinkedList,
+ sym::HashMap,
+ sym::BTreeMap,
+ sym::HashSet,
+ sym::BTreeSet,
+ sym::BinaryHeap,
+ ];
+
+ if let QPath::TypeRelative(_, method) = path {
+ if method.ident.name == sym::new {
+ if let Some(impl_did) = cx.tcx.impl_of_method(def_id) {
+ if let Some(adt) = cx.tcx.type_of(impl_did).ty_adt_def() {
+ return std_types_symbols
+ .iter()
+ .any(|&symbol| cx.tcx.is_diagnostic_item(symbol, adt.did()));
+ }
+ }
+ }
+ }
+ false
+}
+
+/// Return true if the expr is equal to `Default::default` when evaluated.
+pub fn is_default_equivalent_call(cx: &LateContext<'_>, repl_func: &Expr<'_>) -> bool {
+ if_chain! {
+ if let hir::ExprKind::Path(ref repl_func_qpath) = repl_func.kind;
+ if let Some(repl_def_id) = cx.qpath_res(repl_func_qpath, repl_func.hir_id).opt_def_id();
+ if is_diag_trait_item(cx, repl_def_id, sym::Default)
+ || is_default_equivalent_ctor(cx, repl_def_id, repl_func_qpath);
+ then { true } else { false }
+ }
+}
+
+/// Returns true if the expr is equal to `Default::default()` of it's type when evaluated.
+/// It doesn't cover all cases, for example indirect function calls (some of std
+/// functions are supported) but it is the best we have.
+pub fn is_default_equivalent(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
+ match &e.kind {
+ ExprKind::Lit(lit) => match lit.node {
+ LitKind::Bool(false) | LitKind::Int(0, _) => true,
+ LitKind::Str(s, _) => s.is_empty(),
+ _ => false,
+ },
+ ExprKind::Tup(items) | ExprKind::Array(items) => items.iter().all(|x| is_default_equivalent(cx, x)),
+ ExprKind::Repeat(x, ArrayLen::Body(len)) => if_chain! {
+ if let ExprKind::Lit(ref const_lit) = cx.tcx.hir().body(len.body).value.kind;
+ if let LitKind::Int(v, _) = const_lit.node;
+ if v <= 32 && is_default_equivalent(cx, x);
+ then {
+ true
+ }
+ else {
+ false
+ }
+ },
+ ExprKind::Call(repl_func, _) => is_default_equivalent_call(cx, repl_func),
+ ExprKind::Path(qpath) => is_lang_ctor(cx, qpath, OptionNone),
+ ExprKind::AddrOf(rustc_hir::BorrowKind::Ref, _, expr) => matches!(expr.kind, ExprKind::Array([])),
+ _ => false,
+ }
+}
+
+/// Checks if the top level expression can be moved into a closure as is.
+/// Currently checks for:
+/// * Break/Continue outside the given loop HIR ids.
+/// * Yield/Return statements.
+/// * Inline assembly.
+/// * Usages of a field of a local where the type of the local can be partially moved.
+///
+/// For example, given the following function:
+///
+/// ```
+/// fn f<'a>(iter: &mut impl Iterator<Item = (usize, &'a mut String)>) {
+/// for item in iter {
+/// let s = item.1;
+/// if item.0 > 10 {
+/// continue;
+/// } else {
+/// s.clear();
+/// }
+/// }
+/// }
+/// ```
+///
+/// When called on the expression `item.0` this will return false unless the local `item` is in the
+/// `ignore_locals` set. The type `(usize, &mut String)` can have the second element moved, so it
+/// isn't always safe to move into a closure when only a single field is needed.
+///
+/// When called on the `continue` expression this will return false unless the outer loop expression
+/// is in the `loop_ids` set.
+///
+/// Note that this check is not recursive, so passing the `if` expression will always return true
+/// even though sub-expressions might return false.
+pub fn can_move_expr_to_closure_no_visit<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx Expr<'_>,
+ loop_ids: &[HirId],
+ ignore_locals: &HirIdSet,
+) -> bool {
+ match expr.kind {
+ ExprKind::Break(Destination { target_id: Ok(id), .. }, _)
+ | ExprKind::Continue(Destination { target_id: Ok(id), .. })
+ if loop_ids.contains(&id) =>
+ {
+ true
+ },
+ ExprKind::Break(..)
+ | ExprKind::Continue(_)
+ | ExprKind::Ret(_)
+ | ExprKind::Yield(..)
+ | ExprKind::InlineAsm(_) => false,
+ // Accessing a field of a local value can only be done if the type isn't
+ // partially moved.
+ ExprKind::Field(
+ &Expr {
+ hir_id,
+ kind:
+ ExprKind::Path(QPath::Resolved(
+ _,
+ Path {
+ res: Res::Local(local_id),
+ ..
+ },
+ )),
+ ..
+ },
+ _,
+ ) if !ignore_locals.contains(local_id) && can_partially_move_ty(cx, cx.typeck_results().node_type(hir_id)) => {
+ // TODO: check if the local has been partially moved. Assume it has for now.
+ false
+ },
+ _ => true,
+ }
+}
+
+/// How a local is captured by a closure
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum CaptureKind {
+ Value,
+ Ref(Mutability),
+}
+impl CaptureKind {
+ pub fn is_imm_ref(self) -> bool {
+ self == Self::Ref(Mutability::Not)
+ }
+}
+impl std::ops::BitOr for CaptureKind {
+ type Output = Self;
+ fn bitor(self, rhs: Self) -> Self::Output {
+ match (self, rhs) {
+ (CaptureKind::Value, _) | (_, CaptureKind::Value) => CaptureKind::Value,
+ (CaptureKind::Ref(Mutability::Mut), CaptureKind::Ref(_))
+ | (CaptureKind::Ref(_), CaptureKind::Ref(Mutability::Mut)) => CaptureKind::Ref(Mutability::Mut),
+ (CaptureKind::Ref(Mutability::Not), CaptureKind::Ref(Mutability::Not)) => CaptureKind::Ref(Mutability::Not),
+ }
+ }
+}
+impl std::ops::BitOrAssign for CaptureKind {
+ fn bitor_assign(&mut self, rhs: Self) {
+ *self = *self | rhs;
+ }
+}
+
+/// Given an expression referencing a local, determines how it would be captured in a closure.
+/// Note as this will walk up to parent expressions until the capture can be determined it should
+/// only be used while making a closure somewhere a value is consumed. e.g. a block, match arm, or
+/// function argument (other than a receiver).
+pub fn capture_local_usage<'tcx>(cx: &LateContext<'tcx>, e: &Expr<'_>) -> CaptureKind {
+ fn pat_capture_kind(cx: &LateContext<'_>, pat: &Pat<'_>) -> CaptureKind {
+ let mut capture = CaptureKind::Ref(Mutability::Not);
+ pat.each_binding_or_first(&mut |_, id, span, _| match cx
+ .typeck_results()
+ .extract_binding_mode(cx.sess(), id, span)
+ .unwrap()
+ {
+ BindingMode::BindByValue(_) if !is_copy(cx, cx.typeck_results().node_type(id)) => {
+ capture = CaptureKind::Value;
+ },
+ BindingMode::BindByReference(Mutability::Mut) if capture != CaptureKind::Value => {
+ capture = CaptureKind::Ref(Mutability::Mut);
+ },
+ _ => (),
+ });
+ capture
+ }
+
+ debug_assert!(matches!(
+ e.kind,
+ ExprKind::Path(QPath::Resolved(None, Path { res: Res::Local(_), .. }))
+ ));
+
+ let mut child_id = e.hir_id;
+ let mut capture = CaptureKind::Value;
+ let mut capture_expr_ty = e;
+
+ for (parent_id, parent) in cx.tcx.hir().parent_iter(e.hir_id) {
+ if let [
+ Adjustment {
+ kind: Adjust::Deref(_) | Adjust::Borrow(AutoBorrow::Ref(..)),
+ target,
+ },
+ ref adjust @ ..,
+ ] = *cx
+ .typeck_results()
+ .adjustments()
+ .get(child_id)
+ .map_or(&[][..], |x| &**x)
+ {
+ if let rustc_ty::RawPtr(TypeAndMut { mutbl: mutability, .. }) | rustc_ty::Ref(_, _, mutability) =
+ *adjust.last().map_or(target, |a| a.target).kind()
+ {
+ return CaptureKind::Ref(mutability);
+ }
+ }
+
+ match parent {
+ Node::Expr(e) => match e.kind {
+ ExprKind::AddrOf(_, mutability, _) => return CaptureKind::Ref(mutability),
+ ExprKind::Index(..) | ExprKind::Unary(UnOp::Deref, _) => capture = CaptureKind::Ref(Mutability::Not),
+ ExprKind::Assign(lhs, ..) | ExprKind::Assign(_, lhs, _) if lhs.hir_id == child_id => {
+ return CaptureKind::Ref(Mutability::Mut);
+ },
+ ExprKind::Field(..) => {
+ if capture == CaptureKind::Value {
+ capture_expr_ty = e;
+ }
+ },
+ ExprKind::Let(let_expr) => {
+ let mutability = match pat_capture_kind(cx, let_expr.pat) {
+ CaptureKind::Value => Mutability::Not,
+ CaptureKind::Ref(m) => m,
+ };
+ return CaptureKind::Ref(mutability);
+ },
+ ExprKind::Match(_, arms, _) => {
+ let mut mutability = Mutability::Not;
+ for capture in arms.iter().map(|arm| pat_capture_kind(cx, arm.pat)) {
+ match capture {
+ CaptureKind::Value => break,
+ CaptureKind::Ref(Mutability::Mut) => mutability = Mutability::Mut,
+ CaptureKind::Ref(Mutability::Not) => (),
+ }
+ }
+ return CaptureKind::Ref(mutability);
+ },
+ _ => break,
+ },
+ Node::Local(l) => match pat_capture_kind(cx, l.pat) {
+ CaptureKind::Value => break,
+ capture @ CaptureKind::Ref(_) => return capture,
+ },
+ _ => break,
+ }
+
+ child_id = parent_id;
+ }
+
+ if capture == CaptureKind::Value && is_copy(cx, cx.typeck_results().expr_ty(capture_expr_ty)) {
+ // Copy types are never automatically captured by value.
+ CaptureKind::Ref(Mutability::Not)
+ } else {
+ capture
+ }
+}
+
+/// Checks if the expression can be moved into a closure as is. This will return a list of captures
+/// if so, otherwise, `None`.
+pub fn can_move_expr_to_closure<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<HirIdMap<CaptureKind>> {
+ struct V<'cx, 'tcx> {
+ cx: &'cx LateContext<'tcx>,
+ // Stack of potential break targets contained in the expression.
+ loops: Vec<HirId>,
+ /// Local variables created in the expression. These don't need to be captured.
+ locals: HirIdSet,
+ /// Whether this expression can be turned into a closure.
+ allow_closure: bool,
+ /// Locals which need to be captured, and whether they need to be by value, reference, or
+ /// mutable reference.
+ captures: HirIdMap<CaptureKind>,
+ }
+ impl<'tcx> Visitor<'tcx> for V<'_, 'tcx> {
+ fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
+ if !self.allow_closure {
+ return;
+ }
+
+ match e.kind {
+ ExprKind::Path(QPath::Resolved(None, &Path { res: Res::Local(l), .. })) => {
+ if !self.locals.contains(&l) {
+ let cap = capture_local_usage(self.cx, e);
+ self.captures.entry(l).and_modify(|e| *e |= cap).or_insert(cap);
+ }
+ },
+ ExprKind::Closure(..) => {
+ let closure_id = self.cx.tcx.hir().local_def_id(e.hir_id).to_def_id();
+ for capture in self.cx.typeck_results().closure_min_captures_flattened(closure_id) {
+ let local_id = match capture.place.base {
+ PlaceBase::Local(id) => id,
+ PlaceBase::Upvar(var) => var.var_path.hir_id,
+ _ => continue,
+ };
+ if !self.locals.contains(&local_id) {
+ let capture = match capture.info.capture_kind {
+ UpvarCapture::ByValue => CaptureKind::Value,
+ UpvarCapture::ByRef(kind) => match kind {
+ BorrowKind::ImmBorrow => CaptureKind::Ref(Mutability::Not),
+ BorrowKind::UniqueImmBorrow | BorrowKind::MutBorrow => {
+ CaptureKind::Ref(Mutability::Mut)
+ },
+ },
+ };
+ self.captures
+ .entry(local_id)
+ .and_modify(|e| *e |= capture)
+ .or_insert(capture);
+ }
+ }
+ },
+ ExprKind::Loop(b, ..) => {
+ self.loops.push(e.hir_id);
+ self.visit_block(b);
+ self.loops.pop();
+ },
+ _ => {
+ self.allow_closure &= can_move_expr_to_closure_no_visit(self.cx, e, &self.loops, &self.locals);
+ walk_expr(self, e);
+ },
+ }
+ }
+
+ fn visit_pat(&mut self, p: &'tcx Pat<'tcx>) {
+ p.each_binding_or_first(&mut |_, id, _, _| {
+ self.locals.insert(id);
+ });
+ }
+ }
+
+ let mut v = V {
+ cx,
+ allow_closure: true,
+ loops: Vec::new(),
+ locals: HirIdSet::default(),
+ captures: HirIdMap::default(),
+ };
+ v.visit_expr(expr);
+ v.allow_closure.then(|| v.captures)
+}
+
+/// Returns the method names and argument list of nested method call expressions that make up
+/// `expr`. method/span lists are sorted with the most recent call first.
+pub fn method_calls<'tcx>(
+ expr: &'tcx Expr<'tcx>,
+ max_depth: usize,
+) -> (Vec<Symbol>, Vec<&'tcx [Expr<'tcx>]>, Vec<Span>) {
+ let mut method_names = Vec::with_capacity(max_depth);
+ let mut arg_lists = Vec::with_capacity(max_depth);
+ let mut spans = Vec::with_capacity(max_depth);
+
+ let mut current = expr;
+ for _ in 0..max_depth {
+ if let ExprKind::MethodCall(path, args, _) = ¤t.kind {
+ if args.iter().any(|e| e.span.from_expansion()) {
+ break;
+ }
+ method_names.push(path.ident.name);
+ arg_lists.push(&**args);
+ spans.push(path.ident.span);
+ current = &args[0];
+ } else {
+ break;
+ }
+ }
+
+ (method_names, arg_lists, spans)
+}
+
+/// Matches an `Expr` against a chain of methods, and return the matched `Expr`s.
+///
+/// For example, if `expr` represents the `.baz()` in `foo.bar().baz()`,
+/// `method_chain_args(expr, &["bar", "baz"])` will return a `Vec`
+/// containing the `Expr`s for
+/// `.bar()` and `.baz()`
+pub fn method_chain_args<'a>(expr: &'a Expr<'_>, methods: &[&str]) -> Option<Vec<&'a [Expr<'a>]>> {
+ let mut current = expr;
+ let mut matched = Vec::with_capacity(methods.len());
+ for method_name in methods.iter().rev() {
+ // method chains are stored last -> first
+ if let ExprKind::MethodCall(path, args, _) = current.kind {
+ if path.ident.name.as_str() == *method_name {
+ if args.iter().any(|e| e.span.from_expansion()) {
+ return None;
+ }
+ matched.push(args); // build up `matched` backwards
+ current = &args[0]; // go to parent expression
+ } else {
+ return None;
+ }
+ } else {
+ return None;
+ }
+ }
+ // Reverse `matched` so that it is in the same order as `methods`.
+ matched.reverse();
+ Some(matched)
+}
+
+/// Returns `true` if the provided `def_id` is an entrypoint to a program.
+pub fn is_entrypoint_fn(cx: &LateContext<'_>, def_id: DefId) -> bool {
+ cx.tcx
+ .entry_fn(())
+ .map_or(false, |(entry_fn_def_id, _)| def_id == entry_fn_def_id)
+}
+
+/// Returns `true` if the expression is in the program's `#[panic_handler]`.
+pub fn is_in_panic_handler(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
+ let parent = cx.tcx.hir().get_parent_item(e.hir_id);
+ Some(parent.to_def_id()) == cx.tcx.lang_items().panic_impl()
+}
+
+/// Gets the name of the item the expression is in, if available.
+pub fn get_item_name(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<Symbol> {
+ let parent_id = cx.tcx.hir().get_parent_item(expr.hir_id);
+ match cx.tcx.hir().find_by_def_id(parent_id) {
+ Some(
+ Node::Item(Item { ident, .. })
+ | Node::TraitItem(TraitItem { ident, .. })
+ | Node::ImplItem(ImplItem { ident, .. }),
+ ) => Some(ident.name),
+ _ => None,
+ }
+}
+
+pub struct ContainsName {
+ pub name: Symbol,
+ pub result: bool,
+}
+
+impl<'tcx> Visitor<'tcx> for ContainsName {
+ fn visit_name(&mut self, _: Span, name: Symbol) {
+ if self.name == name {
+ self.result = true;
+ }
+ }
+}
+
+/// Checks if an `Expr` contains a certain name.
+pub fn contains_name(name: Symbol, expr: &Expr<'_>) -> bool {
+ let mut cn = ContainsName { name, result: false };
+ cn.visit_expr(expr);
+ cn.result
+}
+
+/// Returns `true` if `expr` contains a return expression
+pub fn contains_return(expr: &hir::Expr<'_>) -> bool {
+ let mut found = false;
+ expr_visitor_no_bodies(|expr| {
+ if !found {
+ if let hir::ExprKind::Ret(..) = &expr.kind {
+ found = true;
+ }
+ }
+ !found
+ })
+ .visit_expr(expr);
+ found
+}
+
+/// Extends the span to the beginning of the spans line, incl. whitespaces.
+///
+/// ```rust
+/// let x = ();
+/// // ^^
+/// // will be converted to
+/// let x = ();
+/// // ^^^^^^^^^^^^^^
+/// ```
+fn line_span<T: LintContext>(cx: &T, span: Span) -> Span {
+ let span = original_sp(span, DUMMY_SP);
+ let source_map_and_line = cx.sess().source_map().lookup_line(span.lo()).unwrap();
+ let line_no = source_map_and_line.line;
+ let line_start = source_map_and_line.sf.lines(|lines| lines[line_no]);
+ span.with_lo(line_start)
+}
+
+/// Gets the parent node, if any.
+pub fn get_parent_node(tcx: TyCtxt<'_>, id: HirId) -> Option<Node<'_>> {
+ tcx.hir().parent_iter(id).next().map(|(_, node)| node)
+}
+
+/// Gets the parent expression, if any –- this is useful to constrain a lint.
+pub fn get_parent_expr<'tcx>(cx: &LateContext<'tcx>, e: &Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
+ get_parent_expr_for_hir(cx, e.hir_id)
+}
+
+/// This retrieves the parent for the given `HirId` if it's an expression. This is useful for
+/// constraint lints
+pub fn get_parent_expr_for_hir<'tcx>(cx: &LateContext<'tcx>, hir_id: hir::HirId) -> Option<&'tcx Expr<'tcx>> {
+ match get_parent_node(cx.tcx, hir_id) {
+ Some(Node::Expr(parent)) => Some(parent),
+ _ => None,
+ }
+}
+
+pub fn get_enclosing_block<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<&'tcx Block<'tcx>> {
+ let map = &cx.tcx.hir();
+ let enclosing_node = map
+ .get_enclosing_scope(hir_id)
+ .and_then(|enclosing_id| map.find(enclosing_id));
+ enclosing_node.and_then(|node| match node {
+ Node::Block(block) => Some(block),
+ Node::Item(&Item {
+ kind: ItemKind::Fn(_, _, eid),
+ ..
+ })
+ | Node::ImplItem(&ImplItem {
+ kind: ImplItemKind::Fn(_, eid),
+ ..
+ }) => match cx.tcx.hir().body(eid).value.kind {
+ ExprKind::Block(block, _) => Some(block),
+ _ => None,
+ },
+ _ => None,
+ })
+}
+
+/// Gets the loop or closure enclosing the given expression, if any.
+pub fn get_enclosing_loop_or_closure<'tcx>(tcx: TyCtxt<'tcx>, expr: &Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
+ for (_, node) in tcx.hir().parent_iter(expr.hir_id) {
+ match node {
+ Node::Expr(
+ e @ Expr {
+ kind: ExprKind::Loop(..) | ExprKind::Closure(..),
+ ..
+ },
+ ) => return Some(e),
+ Node::Expr(_) | Node::Stmt(_) | Node::Block(_) | Node::Local(_) | Node::Arm(_) => (),
+ _ => break,
+ }
+ }
+ None
+}
+
+/// Gets the parent node if it's an impl block.
+pub fn get_parent_as_impl(tcx: TyCtxt<'_>, id: HirId) -> Option<&Impl<'_>> {
+ match tcx.hir().parent_iter(id).next() {
+ Some((
+ _,
+ Node::Item(Item {
+ kind: ItemKind::Impl(imp),
+ ..
+ }),
+ )) => Some(imp),
+ _ => None,
+ }
+}
+
+/// Removes blocks around an expression, only if the block contains just one expression
+/// and no statements. Unsafe blocks are not removed.
+///
+/// Examples:
+/// * `{}` -> `{}`
+/// * `{ x }` -> `x`
+/// * `{{ x }}` -> `x`
+/// * `{ x; }` -> `{ x; }`
+/// * `{ x; y }` -> `{ x; y }`
+/// * `{ unsafe { x } }` -> `unsafe { x }`
+pub fn peel_blocks<'a>(mut expr: &'a Expr<'a>) -> &'a Expr<'a> {
+ while let ExprKind::Block(
+ Block {
+ stmts: [],
+ expr: Some(inner),
+ rules: BlockCheckMode::DefaultBlock,
+ ..
+ },
+ _,
+ ) = expr.kind
+ {
+ expr = inner;
+ }
+ expr
+}
+
+/// Removes blocks around an expression, only if the block contains just one expression
+/// or just one expression statement with a semicolon. Unsafe blocks are not removed.
+///
+/// Examples:
+/// * `{}` -> `{}`
+/// * `{ x }` -> `x`
+/// * `{ x; }` -> `x`
+/// * `{{ x; }}` -> `x`
+/// * `{ x; y }` -> `{ x; y }`
+/// * `{ unsafe { x } }` -> `unsafe { x }`
+pub fn peel_blocks_with_stmt<'a>(mut expr: &'a Expr<'a>) -> &'a Expr<'a> {
+ while let ExprKind::Block(
+ Block {
+ stmts: [],
+ expr: Some(inner),
+ rules: BlockCheckMode::DefaultBlock,
+ ..
+ }
+ | Block {
+ stmts:
+ [
+ Stmt {
+ kind: StmtKind::Expr(inner) | StmtKind::Semi(inner),
+ ..
+ },
+ ],
+ expr: None,
+ rules: BlockCheckMode::DefaultBlock,
+ ..
+ },
+ _,
+ ) = expr.kind
+ {
+ expr = inner;
+ }
+ expr
+}
+
+/// Checks if the given expression is the else clause of either an `if` or `if let` expression.
+pub fn is_else_clause(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool {
+ let mut iter = tcx.hir().parent_iter(expr.hir_id);
+ match iter.next() {
+ Some((
+ _,
+ Node::Expr(Expr {
+ kind: ExprKind::If(_, _, Some(else_expr)),
+ ..
+ }),
+ )) => else_expr.hir_id == expr.hir_id,
+ _ => false,
+ }
+}
+
+/// Checks whether the given expression is a constant integer of the given value.
+/// unlike `is_integer_literal`, this version does const folding
+pub fn is_integer_const(cx: &LateContext<'_>, e: &Expr<'_>, value: u128) -> bool {
+ if is_integer_literal(e, value) {
+ return true;
+ }
+ let enclosing_body = cx.tcx.hir().local_def_id(cx.tcx.hir().enclosing_body_owner(e.hir_id));
+ if let Some((Constant::Int(v), _)) = constant(cx, cx.tcx.typeck(enclosing_body), e) {
+ return value == v;
+ }
+ false
+}
+
+/// Checks whether the given expression is a constant literal of the given value.
+pub fn is_integer_literal(expr: &Expr<'_>, value: u128) -> bool {
+ // FIXME: use constant folding
+ if let ExprKind::Lit(ref spanned) = expr.kind {
+ if let LitKind::Int(v, _) = spanned.node {
+ return v == value;
+ }
+ }
+ false
+}
+
+/// Returns `true` if the given `Expr` has been coerced before.
+///
+/// Examples of coercions can be found in the Nomicon at
+/// <https://doc.rust-lang.org/nomicon/coercions.html>.
+///
+/// See `rustc_middle::ty::adjustment::Adjustment` and `rustc_typeck::check::coercion` for more
+/// information on adjustments and coercions.
+pub fn is_adjusted(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
+ cx.typeck_results().adjustments().get(e.hir_id).is_some()
+}
+
+/// Returns the pre-expansion span if this comes from an expansion of the
+/// macro `name`.
+/// See also [`is_direct_expn_of`].
+#[must_use]
+pub fn is_expn_of(mut span: Span, name: &str) -> Option<Span> {
+ loop {
+ if span.from_expansion() {
+ let data = span.ctxt().outer_expn_data();
+ let new_span = data.call_site;
+
+ if let ExpnKind::Macro(MacroKind::Bang, mac_name) = data.kind {
+ if mac_name.as_str() == name {
+ return Some(new_span);
+ }
+ }
+
+ span = new_span;
+ } else {
+ return None;
+ }
+ }
+}
+
+/// Returns the pre-expansion span if the span directly comes from an expansion
+/// of the macro `name`.
+/// The difference with [`is_expn_of`] is that in
+/// ```rust
+/// # macro_rules! foo { ($name:tt!$args:tt) => { $name!$args } }
+/// # macro_rules! bar { ($e:expr) => { $e } }
+/// foo!(bar!(42));
+/// ```
+/// `42` is considered expanded from `foo!` and `bar!` by `is_expn_of` but only
+/// from `bar!` by `is_direct_expn_of`.
+#[must_use]
+pub fn is_direct_expn_of(span: Span, name: &str) -> Option<Span> {
+ if span.from_expansion() {
+ let data = span.ctxt().outer_expn_data();
+ let new_span = data.call_site;
+
+ if let ExpnKind::Macro(MacroKind::Bang, mac_name) = data.kind {
+ if mac_name.as_str() == name {
+ return Some(new_span);
+ }
+ }
+ }
+
+ None
+}
+
+/// Convenience function to get the return type of a function.
+pub fn return_ty<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId) -> Ty<'tcx> {
+ let fn_def_id = cx.tcx.hir().local_def_id(fn_item);
+ let ret_ty = cx.tcx.fn_sig(fn_def_id).output();
+ cx.tcx.erase_late_bound_regions(ret_ty)
+}
+
+/// Convenience function to get the nth argument type of a function.
+pub fn nth_arg<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId, nth: usize) -> Ty<'tcx> {
+ let fn_def_id = cx.tcx.hir().local_def_id(fn_item);
+ let arg = cx.tcx.fn_sig(fn_def_id).input(nth);
+ cx.tcx.erase_late_bound_regions(arg)
+}
+
+/// Checks if an expression is constructing a tuple-like enum variant or struct
+pub fn is_ctor_or_promotable_const_function(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ if let ExprKind::Call(fun, _) = expr.kind {
+ if let ExprKind::Path(ref qp) = fun.kind {
+ let res = cx.qpath_res(qp, fun.hir_id);
+ return match res {
+ def::Res::Def(DefKind::Variant | DefKind::Ctor(..), ..) => true,
+ def::Res::Def(_, def_id) => cx.tcx.is_promotable_const_fn(def_id),
+ _ => false,
+ };
+ }
+ }
+ false
+}
+
+/// Returns `true` if a pattern is refutable.
+// TODO: should be implemented using rustc/mir_build/thir machinery
+pub fn is_refutable(cx: &LateContext<'_>, pat: &Pat<'_>) -> bool {
+ fn is_enum_variant(cx: &LateContext<'_>, qpath: &QPath<'_>, id: HirId) -> bool {
+ matches!(
+ cx.qpath_res(qpath, id),
+ def::Res::Def(DefKind::Variant, ..) | Res::Def(DefKind::Ctor(def::CtorOf::Variant, _), _)
+ )
+ }
+
+ fn are_refutable<'a, I: IntoIterator<Item = &'a Pat<'a>>>(cx: &LateContext<'_>, i: I) -> bool {
+ i.into_iter().any(|pat| is_refutable(cx, pat))
+ }
+
+ match pat.kind {
+ PatKind::Wild => false,
+ PatKind::Binding(_, _, _, pat) => pat.map_or(false, |pat| is_refutable(cx, pat)),
+ PatKind::Box(pat) | PatKind::Ref(pat, _) => is_refutable(cx, pat),
+ PatKind::Lit(..) | PatKind::Range(..) => true,
+ PatKind::Path(ref qpath) => is_enum_variant(cx, qpath, pat.hir_id),
+ PatKind::Or(pats) => {
+ // TODO: should be the honest check, that pats is exhaustive set
+ are_refutable(cx, pats)
+ },
+ PatKind::Tuple(pats, _) => are_refutable(cx, pats),
+ PatKind::Struct(ref qpath, fields, _) => {
- conds.push(&*cond);
++ is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, fields.iter().map(|field| field.pat))
+ },
+ PatKind::TupleStruct(ref qpath, pats, _) => is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, pats),
+ PatKind::Slice(head, middle, tail) => {
+ match &cx.typeck_results().node_type(pat.hir_id).kind() {
+ rustc_ty::Slice(..) => {
+ // [..] is the only irrefutable slice pattern.
+ !head.is_empty() || middle.is_none() || !tail.is_empty()
+ },
+ rustc_ty::Array(..) => are_refutable(cx, head.iter().chain(middle).chain(tail.iter())),
+ _ => {
+ // unreachable!()
+ true
+ },
+ }
+ },
+ }
+}
+
+/// If the pattern is an `or` pattern, call the function once for each sub pattern. Otherwise, call
+/// the function once on the given pattern.
+pub fn recurse_or_patterns<'tcx, F: FnMut(&'tcx Pat<'tcx>)>(pat: &'tcx Pat<'tcx>, mut f: F) {
+ if let PatKind::Or(pats) = pat.kind {
+ pats.iter().for_each(f);
+ } else {
+ f(pat);
+ }
+}
+
+pub fn is_self(slf: &Param<'_>) -> bool {
+ if let PatKind::Binding(.., name, _) = slf.pat.kind {
+ name.name == kw::SelfLower
+ } else {
+ false
+ }
+}
+
+pub fn is_self_ty(slf: &hir::Ty<'_>) -> bool {
+ if let TyKind::Path(QPath::Resolved(None, path)) = slf.kind {
+ if let Res::SelfTy { .. } = path.res {
+ return true;
+ }
+ }
+ false
+}
+
+pub fn iter_input_pats<'tcx>(decl: &FnDecl<'_>, body: &'tcx Body<'_>) -> impl Iterator<Item = &'tcx Param<'tcx>> {
+ (0..decl.inputs.len()).map(move |i| &body.params[i])
+}
+
+/// Checks if a given expression is a match expression expanded from the `?`
+/// operator or the `try` macro.
+pub fn is_try<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> {
+ fn is_ok(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool {
+ if_chain! {
+ if let PatKind::TupleStruct(ref path, pat, None) = arm.pat.kind;
+ if is_lang_ctor(cx, path, ResultOk);
+ if let PatKind::Binding(_, hir_id, _, None) = pat[0].kind;
+ if path_to_local_id(arm.body, hir_id);
+ then {
+ return true;
+ }
+ }
+ false
+ }
+
+ fn is_err(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool {
+ if let PatKind::TupleStruct(ref path, _, _) = arm.pat.kind {
+ is_lang_ctor(cx, path, ResultErr)
+ } else {
+ false
+ }
+ }
+
+ if let ExprKind::Match(_, arms, ref source) = expr.kind {
+ // desugared from a `?` operator
+ if *source == MatchSource::TryDesugar {
+ return Some(expr);
+ }
+
+ if_chain! {
+ if arms.len() == 2;
+ if arms[0].guard.is_none();
+ if arms[1].guard.is_none();
+ if (is_ok(cx, &arms[0]) && is_err(cx, &arms[1])) || (is_ok(cx, &arms[1]) && is_err(cx, &arms[0]));
+ then {
+ return Some(expr);
+ }
+ }
+ }
+
+ None
+}
+
+/// Returns `true` if the lint is allowed in the current context
+///
+/// Useful for skipping long running code when it's unnecessary
+pub fn is_lint_allowed(cx: &LateContext<'_>, lint: &'static Lint, id: HirId) -> bool {
+ cx.tcx.lint_level_at_node(lint, id).0 == Level::Allow
+}
+
+pub fn strip_pat_refs<'hir>(mut pat: &'hir Pat<'hir>) -> &'hir Pat<'hir> {
+ while let PatKind::Ref(subpat, _) = pat.kind {
+ pat = subpat;
+ }
+ pat
+}
+
+pub fn int_bits(tcx: TyCtxt<'_>, ity: rustc_ty::IntTy) -> u64 {
+ Integer::from_int_ty(&tcx, ity).size().bits()
+}
+
+#[expect(clippy::cast_possible_wrap)]
+/// Turn a constant int byte representation into an i128
+pub fn sext(tcx: TyCtxt<'_>, u: u128, ity: rustc_ty::IntTy) -> i128 {
+ let amt = 128 - int_bits(tcx, ity);
+ ((u as i128) << amt) >> amt
+}
+
+#[expect(clippy::cast_sign_loss)]
+/// clip unused bytes
+pub fn unsext(tcx: TyCtxt<'_>, u: i128, ity: rustc_ty::IntTy) -> u128 {
+ let amt = 128 - int_bits(tcx, ity);
+ ((u as u128) << amt) >> amt
+}
+
+/// clip unused bytes
+pub fn clip(tcx: TyCtxt<'_>, u: u128, ity: rustc_ty::UintTy) -> u128 {
+ let bits = Integer::from_uint_ty(&tcx, ity).size().bits();
+ let amt = 128 - bits;
+ (u << amt) >> amt
+}
+
+pub fn has_attr(attrs: &[ast::Attribute], symbol: Symbol) -> bool {
+ attrs.iter().any(|attr| attr.has_name(symbol))
+}
+
+pub fn any_parent_has_attr(tcx: TyCtxt<'_>, node: HirId, symbol: Symbol) -> bool {
+ let map = &tcx.hir();
+ let mut prev_enclosing_node = None;
+ let mut enclosing_node = node;
+ while Some(enclosing_node) != prev_enclosing_node {
+ if has_attr(map.attrs(enclosing_node), symbol) {
+ return true;
+ }
+ prev_enclosing_node = Some(enclosing_node);
+ enclosing_node = map.local_def_id_to_hir_id(map.get_parent_item(enclosing_node));
+ }
+
+ false
+}
+
+pub fn any_parent_is_automatically_derived(tcx: TyCtxt<'_>, node: HirId) -> bool {
+ any_parent_has_attr(tcx, node, sym::automatically_derived)
+}
+
+/// Matches a function call with the given path and returns the arguments.
+///
+/// Usage:
+///
+/// ```rust,ignore
+/// if let Some(args) = match_function_call(cx, cmp_max_call, &paths::CMP_MAX);
+/// ```
+pub fn match_function_call<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx Expr<'_>,
+ path: &[&str],
+) -> Option<&'tcx [Expr<'tcx>]> {
+ if_chain! {
+ if let ExprKind::Call(fun, args) = expr.kind;
+ if let ExprKind::Path(ref qpath) = fun.kind;
+ if let Some(fun_def_id) = cx.qpath_res(qpath, fun.hir_id).opt_def_id();
+ if match_def_path(cx, fun_def_id, path);
+ then {
+ return Some(args);
+ }
+ };
+ None
+}
+
+/// Checks if the given `DefId` matches any of the paths. Returns the index of matching path, if
+/// any.
+///
+/// Please use `tcx.get_diagnostic_name` if the targets are all diagnostic items.
+pub fn match_any_def_paths(cx: &LateContext<'_>, did: DefId, paths: &[&[&str]]) -> Option<usize> {
+ let search_path = cx.get_def_path(did);
+ paths
+ .iter()
+ .position(|p| p.iter().map(|x| Symbol::intern(x)).eq(search_path.iter().copied()))
+}
+
+/// Checks if the given `DefId` matches the path.
+pub fn match_def_path<'tcx>(cx: &LateContext<'tcx>, did: DefId, syms: &[&str]) -> bool {
+ // We should probably move to Symbols in Clippy as well rather than interning every time.
+ let path = cx.get_def_path(did);
+ syms.iter().map(|x| Symbol::intern(x)).eq(path.iter().copied())
+}
+
+/// Checks if the given `DefId` matches the `libc` item.
+pub fn match_libc_symbol(cx: &LateContext<'_>, did: DefId, name: &str) -> bool {
+ let path = cx.get_def_path(did);
+ // libc is meant to be used as a flat list of names, but they're all actually defined in different
+ // modules based on the target platform. Ignore everything but crate name and the item name.
+ path.first().map_or(false, |s| s.as_str() == "libc") && path.last().map_or(false, |s| s.as_str() == name)
+}
+
+/// Returns the list of condition expressions and the list of blocks in a
+/// sequence of `if/else`.
+/// E.g., this returns `([a, b], [c, d, e])` for the expression
+/// `if a { c } else if b { d } else { e }`.
+pub fn if_sequence<'tcx>(mut expr: &'tcx Expr<'tcx>) -> (Vec<&'tcx Expr<'tcx>>, Vec<&'tcx Block<'tcx>>) {
+ let mut conds = Vec::new();
+ let mut blocks: Vec<&Block<'_>> = Vec::new();
+
+ while let Some(higher::IfOrIfLet { cond, then, r#else }) = higher::IfOrIfLet::hir(expr) {
- ) => cx.typeck_results().qpath_res(qpath, *path_hir_id).opt_def_id(),
++ conds.push(cond);
+ if let ExprKind::Block(block, _) = then.kind {
+ blocks.push(block);
+ } else {
+ panic!("ExprKind::If node is not an ExprKind::Block");
+ }
+
+ if let Some(else_expr) = r#else {
+ expr = else_expr;
+ } else {
+ break;
+ }
+ }
+
+ // final `else {..}`
+ if !blocks.is_empty() {
+ if let ExprKind::Block(block, _) = expr.kind {
+ blocks.push(block);
+ }
+ }
+
+ (conds, blocks)
+}
+
+/// Checks if the given function kind is an async function.
+pub fn is_async_fn(kind: FnKind<'_>) -> bool {
+ matches!(kind, FnKind::ItemFn(_, _, header) if header.asyncness == IsAsync::Async)
+}
+
+/// Peels away all the compiler generated code surrounding the body of an async function,
+pub fn get_async_fn_body<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'_>) -> Option<&'tcx Expr<'tcx>> {
+ if let ExprKind::Call(
+ _,
+ &[
+ Expr {
+ kind: ExprKind::Closure(_, _, body, _, _),
+ ..
+ },
+ ],
+ ) = body.value.kind
+ {
+ if let ExprKind::Block(
+ Block {
+ stmts: [],
+ expr:
+ Some(Expr {
+ kind: ExprKind::DropTemps(expr),
+ ..
+ }),
+ ..
+ },
+ _,
+ ) = tcx.hir().body(body).value.kind
+ {
+ return Some(expr);
+ }
+ };
+ None
+}
+
+// check if expr is calling method or function with #[must_use] attribute
+pub fn is_must_use_func_call(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ let did = match expr.kind {
+ ExprKind::Call(path, _) => if_chain! {
+ if let ExprKind::Path(ref qpath) = path.kind;
+ if let def::Res::Def(_, did) = cx.qpath_res(qpath, path.hir_id);
+ then {
+ Some(did)
+ } else {
+ None
+ }
+ },
+ ExprKind::MethodCall(..) => cx.typeck_results().type_dependent_def_id(expr.hir_id),
+ _ => None,
+ };
+
+ did.map_or(false, |did| cx.tcx.has_attr(did, sym::must_use))
+}
+
+/// Checks if an expression represents the identity function
+/// Only examines closures and `std::convert::identity`
+pub fn is_expr_identity_function(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ /// Checks if a function's body represents the identity function. Looks for bodies of the form:
+ /// * `|x| x`
+ /// * `|x| return x`
+ /// * `|x| { return x }`
+ /// * `|x| { return x; }`
+ fn is_body_identity_function(cx: &LateContext<'_>, func: &Body<'_>) -> bool {
+ let id = if_chain! {
+ if let [param] = func.params;
+ if let PatKind::Binding(_, id, _, _) = param.pat.kind;
+ then {
+ id
+ } else {
+ return false;
+ }
+ };
+
+ let mut expr = &func.value;
+ loop {
+ match expr.kind {
+ #[rustfmt::skip]
+ ExprKind::Block(&Block { stmts: [], expr: Some(e), .. }, _, )
+ | ExprKind::Ret(Some(e)) => expr = e,
+ #[rustfmt::skip]
+ ExprKind::Block(&Block { stmts: [stmt], expr: None, .. }, _) => {
+ if_chain! {
+ if let StmtKind::Semi(e) | StmtKind::Expr(e) = stmt.kind;
+ if let ExprKind::Ret(Some(ret_val)) = e.kind;
+ then {
+ expr = ret_val;
+ } else {
+ return false;
+ }
+ }
+ },
+ _ => return path_to_local_id(expr, id) && cx.typeck_results().expr_adjustments(expr).is_empty(),
+ }
+ }
+ }
+
+ match expr.kind {
+ ExprKind::Closure(_, _, body_id, _, _) => is_body_identity_function(cx, cx.tcx.hir().body(body_id)),
+ _ => path_def_id(cx, expr).map_or(false, |id| match_def_path(cx, id, &paths::CONVERT_IDENTITY)),
+ }
+}
+
+/// Gets the node where an expression is either used, or it's type is unified with another branch.
+/// Returns both the node and the `HirId` of the closest child node.
+pub fn get_expr_use_or_unification_node<'tcx>(tcx: TyCtxt<'tcx>, expr: &Expr<'_>) -> Option<(Node<'tcx>, HirId)> {
+ let mut child_id = expr.hir_id;
+ let mut iter = tcx.hir().parent_iter(child_id);
+ loop {
+ match iter.next() {
+ None => break None,
+ Some((id, Node::Block(_))) => child_id = id,
+ Some((id, Node::Arm(arm))) if arm.body.hir_id == child_id => child_id = id,
+ Some((_, Node::Expr(expr))) => match expr.kind {
+ ExprKind::Match(_, [arm], _) if arm.hir_id == child_id => child_id = expr.hir_id,
+ ExprKind::Block(..) | ExprKind::DropTemps(_) => child_id = expr.hir_id,
+ ExprKind::If(_, then_expr, None) if then_expr.hir_id == child_id => break None,
+ _ => break Some((Node::Expr(expr), child_id)),
+ },
+ Some((_, node)) => break Some((node, child_id)),
+ }
+ }
+}
+
+/// Checks if the result of an expression is used, or it's type is unified with another branch.
+pub fn is_expr_used_or_unified(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool {
+ !matches!(
+ get_expr_use_or_unification_node(tcx, expr),
+ None | Some((
+ Node::Stmt(Stmt {
+ kind: StmtKind::Expr(_)
+ | StmtKind::Semi(_)
+ | StmtKind::Local(Local {
+ pat: Pat {
+ kind: PatKind::Wild,
+ ..
+ },
+ ..
+ }),
+ ..
+ }),
+ _
+ ))
+ )
+}
+
+/// Checks if the expression is the final expression returned from a block.
+pub fn is_expr_final_block_expr(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool {
+ matches!(get_parent_node(tcx, expr.hir_id), Some(Node::Block(..)))
+}
+
+pub fn std_or_core(cx: &LateContext<'_>) -> Option<&'static str> {
+ if !is_no_std_crate(cx) {
+ Some("std")
+ } else if !is_no_core_crate(cx) {
+ Some("core")
+ } else {
+ None
+ }
+}
+
+pub fn is_no_std_crate(cx: &LateContext<'_>) -> bool {
+ cx.tcx.hir().attrs(hir::CRATE_HIR_ID).iter().any(|attr| {
+ if let ast::AttrKind::Normal(ref attr, _) = attr.kind {
+ attr.path == sym::no_std
+ } else {
+ false
+ }
+ })
+}
+
+pub fn is_no_core_crate(cx: &LateContext<'_>) -> bool {
+ cx.tcx.hir().attrs(hir::CRATE_HIR_ID).iter().any(|attr| {
+ if let ast::AttrKind::Normal(ref attr, _) = attr.kind {
+ attr.path == sym::no_core
+ } else {
+ false
+ }
+ })
+}
+
+/// Check if parent of a hir node is a trait implementation block.
+/// For example, `f` in
+/// ```rust
+/// # struct S;
+/// # trait Trait { fn f(); }
+/// impl Trait for S {
+/// fn f() {}
+/// }
+/// ```
+pub fn is_trait_impl_item(cx: &LateContext<'_>, hir_id: HirId) -> bool {
+ if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) {
+ matches!(item.kind, ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }))
+ } else {
+ false
+ }
+}
+
+/// Check if it's even possible to satisfy the `where` clause for the item.
+///
+/// `trivial_bounds` feature allows functions with unsatisfiable bounds, for example:
+///
+/// ```ignore
+/// fn foo() where i32: Iterator {
+/// for _ in 2i32 {}
+/// }
+/// ```
+pub fn fn_has_unsatisfiable_preds(cx: &LateContext<'_>, did: DefId) -> bool {
+ use rustc_trait_selection::traits;
+ let predicates = cx
+ .tcx
+ .predicates_of(did)
+ .predicates
+ .iter()
+ .filter_map(|(p, _)| if p.is_global() { Some(*p) } else { None });
+ traits::impossible_predicates(
+ cx.tcx,
+ traits::elaborate_predicates(cx.tcx, predicates)
+ .map(|o| o.predicate)
+ .collect::<Vec<_>>(),
+ )
+}
+
+/// Returns the `DefId` of the callee if the given expression is a function or method call.
+pub fn fn_def_id(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<DefId> {
+ match &expr.kind {
+ ExprKind::MethodCall(..) => cx.typeck_results().type_dependent_def_id(expr.hir_id),
+ ExprKind::Call(
+ Expr {
+ kind: ExprKind::Path(qpath),
+ hir_id: path_hir_id,
+ ..
+ },
+ ..,
- match map.entry(module) {
++ ) => {
++ // Only return Fn-like DefIds, not the DefIds of statics/consts/etc that contain or
++ // deref to fn pointers, dyn Fn, impl Fn - #8850
++ if let Res::Def(DefKind::Fn | DefKind::Ctor(..) | DefKind::AssocFn, id) =
++ cx.typeck_results().qpath_res(qpath, *path_hir_id)
++ {
++ Some(id)
++ } else {
++ None
++ }
++ },
+ _ => None,
+ }
+}
+
+/// Returns Option<String> where String is a textual representation of the type encapsulated in the
+/// slice iff the given expression is a slice of primitives (as defined in the
+/// `is_recursively_primitive_type` function) and None otherwise.
+pub fn is_slice_of_primitives(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<String> {
+ let expr_type = cx.typeck_results().expr_ty_adjusted(expr);
+ let expr_kind = expr_type.kind();
+ let is_primitive = match expr_kind {
+ rustc_ty::Slice(element_type) => is_recursively_primitive_type(*element_type),
+ rustc_ty::Ref(_, inner_ty, _) if matches!(inner_ty.kind(), &rustc_ty::Slice(_)) => {
+ if let rustc_ty::Slice(element_type) = inner_ty.kind() {
+ is_recursively_primitive_type(*element_type)
+ } else {
+ unreachable!()
+ }
+ },
+ _ => false,
+ };
+
+ if is_primitive {
+ // if we have wrappers like Array, Slice or Tuple, print these
+ // and get the type enclosed in the slice ref
+ match expr_type.peel_refs().walk().nth(1).unwrap().expect_ty().kind() {
+ rustc_ty::Slice(..) => return Some("slice".into()),
+ rustc_ty::Array(..) => return Some("array".into()),
+ rustc_ty::Tuple(..) => return Some("tuple".into()),
+ _ => {
+ // is_recursively_primitive_type() should have taken care
+ // of the rest and we can rely on the type that is found
+ let refs_peeled = expr_type.peel_refs();
+ return Some(refs_peeled.walk().last().unwrap().to_string());
+ },
+ }
+ }
+ None
+}
+
+/// returns list of all pairs (a, b) from `exprs` such that `eq(a, b)`
+/// `hash` must be comformed with `eq`
+pub fn search_same<T, Hash, Eq>(exprs: &[T], hash: Hash, eq: Eq) -> Vec<(&T, &T)>
+where
+ Hash: Fn(&T) -> u64,
+ Eq: Fn(&T, &T) -> bool,
+{
+ match exprs {
+ [a, b] if eq(a, b) => return vec![(a, b)],
+ _ if exprs.len() <= 2 => return vec![],
+ _ => {},
+ }
+
+ let mut match_expr_list: Vec<(&T, &T)> = Vec::new();
+
+ let mut map: UnhashMap<u64, Vec<&_>> =
+ UnhashMap::with_capacity_and_hasher(exprs.len(), BuildHasherDefault::default());
+
+ for expr in exprs {
+ match map.entry(hash(expr)) {
+ Entry::Occupied(mut o) => {
+ for o in o.get() {
+ if eq(o, expr) {
+ match_expr_list.push((o, expr));
+ }
+ }
+ o.get_mut().push(expr);
+ },
+ Entry::Vacant(v) => {
+ v.insert(vec![expr]);
+ },
+ }
+ }
+
+ match_expr_list
+}
+
+/// Peels off all references on the pattern. Returns the underlying pattern and the number of
+/// references removed.
+pub fn peel_hir_pat_refs<'a>(pat: &'a Pat<'a>) -> (&'a Pat<'a>, usize) {
+ fn peel<'a>(pat: &'a Pat<'a>, count: usize) -> (&'a Pat<'a>, usize) {
+ if let PatKind::Ref(pat, _) = pat.kind {
+ peel(pat, count + 1)
+ } else {
+ (pat, count)
+ }
+ }
+ peel(pat, 0)
+}
+
+/// Peels of expressions while the given closure returns `Some`.
+pub fn peel_hir_expr_while<'tcx>(
+ mut expr: &'tcx Expr<'tcx>,
+ mut f: impl FnMut(&'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>>,
+) -> &'tcx Expr<'tcx> {
+ while let Some(e) = f(expr) {
+ expr = e;
+ }
+ expr
+}
+
+/// Peels off up to the given number of references on the expression. Returns the underlying
+/// expression and the number of references removed.
+pub fn peel_n_hir_expr_refs<'a>(expr: &'a Expr<'a>, count: usize) -> (&'a Expr<'a>, usize) {
+ let mut remaining = count;
+ let e = peel_hir_expr_while(expr, |e| match e.kind {
+ ExprKind::AddrOf(ast::BorrowKind::Ref, _, e) if remaining != 0 => {
+ remaining -= 1;
+ Some(e)
+ },
+ _ => None,
+ });
+ (e, count - remaining)
+}
+
+/// Peels off all references on the expression. Returns the underlying expression and the number of
+/// references removed.
+pub fn peel_hir_expr_refs<'a>(expr: &'a Expr<'a>) -> (&'a Expr<'a>, usize) {
+ let mut count = 0;
+ let e = peel_hir_expr_while(expr, |e| match e.kind {
+ ExprKind::AddrOf(ast::BorrowKind::Ref, _, e) => {
+ count += 1;
+ Some(e)
+ },
+ _ => None,
+ });
+ (e, count)
+}
+
+/// Removes `AddrOf` operators (`&`) or deref operators (`*`), but only if a reference type is
+/// dereferenced. An overloaded deref such as `Vec` to slice would not be removed.
+pub fn peel_ref_operators<'hir>(cx: &LateContext<'_>, mut expr: &'hir Expr<'hir>) -> &'hir Expr<'hir> {
+ loop {
+ match expr.kind {
+ ExprKind::AddrOf(_, _, e) => expr = e,
+ ExprKind::Unary(UnOp::Deref, e) if cx.typeck_results().expr_ty(e).is_ref() => expr = e,
+ _ => break,
+ }
+ }
+ expr
+}
+
+pub fn is_hir_ty_cfg_dependant(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> bool {
+ if let TyKind::Path(QPath::Resolved(_, path)) = ty.kind {
+ if let Res::Def(_, def_id) = path.res {
+ return cx.tcx.has_attr(def_id, sym::cfg) || cx.tcx.has_attr(def_id, sym::cfg_attr);
+ }
+ }
+ false
+}
+
+static TEST_ITEM_NAMES_CACHE: SyncOnceCell<Mutex<FxHashMap<LocalDefId, Vec<Symbol>>>> = SyncOnceCell::new();
+
+fn with_test_item_names<'tcx>(tcx: TyCtxt<'tcx>, module: LocalDefId, f: impl Fn(&[Symbol]) -> bool) -> bool {
+ let cache = TEST_ITEM_NAMES_CACHE.get_or_init(|| Mutex::new(FxHashMap::default()));
+ let mut map: MutexGuard<'_, FxHashMap<LocalDefId, Vec<Symbol>>> = cache.lock().unwrap();
++ let value = map.entry(module);
++ match value {
+ Entry::Occupied(entry) => f(entry.get()),
+ Entry::Vacant(entry) => {
+ let mut names = Vec::new();
+ for id in tcx.hir().module_items(module) {
+ if matches!(tcx.def_kind(id.def_id), DefKind::Const)
+ && let item = tcx.hir().item(id)
+ && let ItemKind::Const(ty, _body) = item.kind {
+ if let TyKind::Path(QPath::Resolved(_, path)) = ty.kind {
+ // We could also check for the type name `test::TestDescAndFn`
+ if let Res::Def(DefKind::Struct, _) = path.res {
+ let has_test_marker = tcx
+ .hir()
+ .attrs(item.hir_id())
+ .iter()
+ .any(|a| a.has_name(sym::rustc_test_marker));
+ if has_test_marker {
+ names.push(item.ident.name);
+ }
+ }
+ }
+ }
+ }
+ names.sort_unstable();
+ f(&*entry.insert(names))
+ },
+ }
+}
+
+/// Checks if the function containing the given `HirId` is a `#[test]` function
+///
+/// Note: Add `// compile-flags: --test` to UI tests with a `#[test]` function
+pub fn is_in_test_function(tcx: TyCtxt<'_>, id: hir::HirId) -> bool {
+ with_test_item_names(tcx, tcx.parent_module(id), |names| {
+ tcx.hir()
+ .parent_iter(id)
+ // Since you can nest functions we need to collect all until we leave
+ // function scope
+ .any(|(_id, node)| {
+ if let Node::Item(item) = node {
+ if let ItemKind::Fn(_, _, _) = item.kind {
+ // Note that we have sorted the item names in the visitor,
+ // so the binary_search gets the same as `contains`, but faster.
+ return names.binary_search(&item.ident.name).is_ok();
+ }
+ }
+ false
+ })
+ })
+}
+
+/// Checks if the item containing the given `HirId` has `#[cfg(test)]` attribute applied
+///
+/// Note: Add `// compile-flags: --test` to UI tests with a `#[cfg(test)]` function
+pub fn is_in_cfg_test(tcx: TyCtxt<'_>, id: hir::HirId) -> bool {
+ fn is_cfg_test(attr: &Attribute) -> bool {
+ if attr.has_name(sym::cfg)
+ && let Some(items) = attr.meta_item_list()
+ && let [item] = &*items
+ && item.has_name(sym::test)
+ {
+ true
+ } else {
+ false
+ }
+ }
+ tcx.hir()
+ .parent_iter(id)
+ .flat_map(|(parent_id, _)| tcx.hir().attrs(parent_id))
+ .any(is_cfg_test)
+}
+
+/// Checks whether item either has `test` attribute applied, or
+/// is a module with `test` in its name.
+///
+/// Note: Add `// compile-flags: --test` to UI tests with a `#[test]` function
+pub fn is_test_module_or_function(tcx: TyCtxt<'_>, item: &Item<'_>) -> bool {
+ is_in_test_function(tcx, item.hir_id())
+ || matches!(item.kind, ItemKind::Mod(..))
+ && item.ident.name.as_str().split('_').any(|a| a == "test" || a == "tests")
+}
+
+macro_rules! op_utils {
+ ($($name:ident $assign:ident)*) => {
+ /// Binary operation traits like `LangItem::Add`
+ pub static BINOP_TRAITS: &[LangItem] = &[$(LangItem::$name,)*];
+
+ /// Operator-Assign traits like `LangItem::AddAssign`
+ pub static OP_ASSIGN_TRAITS: &[LangItem] = &[$(LangItem::$assign,)*];
+
+ /// Converts `BinOpKind::Add` to `(LangItem::Add, LangItem::AddAssign)`, for example
+ pub fn binop_traits(kind: hir::BinOpKind) -> Option<(LangItem, LangItem)> {
+ match kind {
+ $(hir::BinOpKind::$name => Some((LangItem::$name, LangItem::$assign)),)*
+ _ => None,
+ }
+ }
+ };
+}
+
+op_utils! {
+ Add AddAssign
+ Sub SubAssign
+ Mul MulAssign
+ Div DivAssign
+ Rem RemAssign
+ BitXor BitXorAssign
+ BitAnd BitAndAssign
+ BitOr BitOrAssign
+ Shl ShlAssign
+ Shr ShrAssign
+}
--- /dev/null
+use rustc_semver::RustcVersion;
+
+macro_rules! msrv_aliases {
+ ($($major:literal,$minor:literal,$patch:literal {
+ $($name:ident),* $(,)?
+ })*) => {
+ $($(
+ pub const $name: RustcVersion = RustcVersion::new($major, $minor, $patch);
+ )*)*
+ };
+}
+
+// names may refer to stabilized feature flags or library items
+msrv_aliases! {
+ 1,53,0 { OR_PATTERNS, MANUAL_BITS }
+ 1,52,0 { STR_SPLIT_ONCE }
+ 1,51,0 { BORROW_AS_PTR, UNSIGNED_ABS }
+ 1,50,0 { BOOL_THEN }
+ 1,47,0 { TAU }
+ 1,46,0 { CONST_IF_MATCH }
+ 1,45,0 { STR_STRIP_PREFIX }
+ 1,43,0 { LOG2_10, LOG10_2 }
+ 1,42,0 { MATCHES_MACRO, SLICE_PATTERNS, PTR_SLICE_RAW_PARTS }
+ 1,41,0 { RE_REBALANCING_COHERENCE, RESULT_MAP_OR_ELSE }
+ 1,40,0 { MEM_TAKE, NON_EXHAUSTIVE, OPTION_AS_DEREF }
+ 1,38,0 { POINTER_CAST }
+ 1,37,0 { TYPE_ALIAS_ENUM_VARIANTS }
+ 1,36,0 { ITERATOR_COPIED }
+ 1,35,0 { OPTION_COPIED, RANGE_CONTAINS }
+ 1,34,0 { TRY_FROM }
+ 1,30,0 { ITERATOR_FIND_MAP, TOOL_ATTRIBUTES }
+ 1,28,0 { FROM_BOOL }
++ 1,26,0 { RANGE_INCLUSIVE }
+ 1,17,0 { FIELD_INIT_SHORTHAND, STATIC_IN_CONST, EXPECT_ERR }
+ 1,16,0 { STR_REPEAT }
+ 1,24,0 { IS_ASCII_DIGIT }
+}
--- /dev/null
+//! This module contains paths to types and functions Clippy needs to know
+//! about.
+//!
+//! Whenever possible, please consider diagnostic items over hardcoded paths.
+//! See <https://github.com/rust-lang/rust-clippy/issues/5393> for more information.
+
+#[cfg(feature = "internal")]
+pub const APPLICABILITY: [&str; 2] = ["rustc_lint_defs", "Applicability"];
+#[cfg(feature = "internal")]
+pub const APPLICABILITY_VALUES: [[&str; 3]; 4] = [
+ ["rustc_lint_defs", "Applicability", "Unspecified"],
+ ["rustc_lint_defs", "Applicability", "HasPlaceholders"],
+ ["rustc_lint_defs", "Applicability", "MaybeIncorrect"],
+ ["rustc_lint_defs", "Applicability", "MachineApplicable"],
+];
+#[cfg(feature = "internal")]
+pub const DIAGNOSTIC_BUILDER: [&str; 3] = ["rustc_errors", "diagnostic_builder", "DiagnosticBuilder"];
+pub const ARC_PTR_EQ: [&str; 4] = ["alloc", "sync", "Arc", "ptr_eq"];
+pub const ASMUT_TRAIT: [&str; 3] = ["core", "convert", "AsMut"];
+pub const ASREF_TRAIT: [&str; 3] = ["core", "convert", "AsRef"];
+pub const BTREEMAP_CONTAINS_KEY: [&str; 6] = ["alloc", "collections", "btree", "map", "BTreeMap", "contains_key"];
+pub const BTREEMAP_ENTRY: [&str; 6] = ["alloc", "collections", "btree", "map", "entry", "Entry"];
+pub const BTREEMAP_INSERT: [&str; 6] = ["alloc", "collections", "btree", "map", "BTreeMap", "insert"];
+pub const CLONE_TRAIT_METHOD: [&str; 4] = ["core", "clone", "Clone", "clone"];
+pub const COW: [&str; 3] = ["alloc", "borrow", "Cow"];
+pub const CSTRING_AS_C_STR: [&str; 5] = ["alloc", "ffi", "c_str", "CString", "as_c_str"];
+pub const DEFAULT_TRAIT_METHOD: [&str; 4] = ["core", "default", "Default", "default"];
+pub const DEREF_MUT_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "DerefMut", "deref_mut"];
+/// Preferably use the diagnostic item `sym::deref_method` where possible
+pub const DEREF_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "Deref", "deref"];
+pub const DIR_BUILDER: [&str; 3] = ["std", "fs", "DirBuilder"];
+pub const DISPLAY_TRAIT: [&str; 3] = ["core", "fmt", "Display"];
+#[cfg(feature = "internal")]
+pub const EARLY_CONTEXT: [&str; 2] = ["rustc_lint", "EarlyContext"];
+#[cfg(feature = "internal")]
+pub const EARLY_LINT_PASS: [&str; 3] = ["rustc_lint", "passes", "EarlyLintPass"];
+pub const EXIT: [&str; 3] = ["std", "process", "exit"];
+pub const F32_EPSILON: [&str; 4] = ["core", "f32", "<impl f32>", "EPSILON"];
+pub const F64_EPSILON: [&str; 4] = ["core", "f64", "<impl f64>", "EPSILON"];
+pub const FILE: [&str; 3] = ["std", "fs", "File"];
+pub const FILE_TYPE: [&str; 3] = ["std", "fs", "FileType"];
+pub const FROM_FROM: [&str; 4] = ["core", "convert", "From", "from"];
+pub const FROM_ITERATOR_METHOD: [&str; 6] = ["core", "iter", "traits", "collect", "FromIterator", "from_iter"];
+pub const FROM_STR_METHOD: [&str; 5] = ["core", "str", "traits", "FromStr", "from_str"];
+pub const FUTURE_FROM_GENERATOR: [&str; 3] = ["core", "future", "from_generator"];
+#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
+pub const FUTURES_IO_ASYNCREADEXT: [&str; 3] = ["futures_util", "io", "AsyncReadExt"];
+#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
+pub const FUTURES_IO_ASYNCWRITEEXT: [&str; 3] = ["futures_util", "io", "AsyncWriteExt"];
+pub const HASHMAP_CONTAINS_KEY: [&str; 6] = ["std", "collections", "hash", "map", "HashMap", "contains_key"];
+pub const HASHMAP_ENTRY: [&str; 5] = ["std", "collections", "hash", "map", "Entry"];
+pub const HASHMAP_INSERT: [&str; 6] = ["std", "collections", "hash", "map", "HashMap", "insert"];
+#[cfg(feature = "internal")]
+pub const IDENT: [&str; 3] = ["rustc_span", "symbol", "Ident"];
+#[cfg(feature = "internal")]
+pub const IDENT_AS_STR: [&str; 4] = ["rustc_span", "symbol", "Ident", "as_str"];
+pub const INDEX: [&str; 3] = ["core", "ops", "Index"];
+pub const INDEX_MUT: [&str; 3] = ["core", "ops", "IndexMut"];
+pub const INSERT_STR: [&str; 4] = ["alloc", "string", "String", "insert_str"];
+pub const IO_READ: [&str; 3] = ["std", "io", "Read"];
+pub const IO_WRITE: [&str; 3] = ["std", "io", "Write"];
+pub const IPADDR_V4: [&str; 5] = ["std", "net", "ip", "IpAddr", "V4"];
+pub const IPADDR_V6: [&str; 5] = ["std", "net", "ip", "IpAddr", "V6"];
+pub const ITER_COUNT: [&str; 6] = ["core", "iter", "traits", "iterator", "Iterator", "count"];
+pub const ITER_REPEAT: [&str; 5] = ["core", "iter", "sources", "repeat", "repeat"];
+#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
+pub const ITERTOOLS_NEXT_TUPLE: [&str; 3] = ["itertools", "Itertools", "next_tuple"];
+#[cfg(feature = "internal")]
+pub const KW_MODULE: [&str; 3] = ["rustc_span", "symbol", "kw"];
+#[cfg(feature = "internal")]
+pub const LATE_CONTEXT: [&str; 2] = ["rustc_lint", "LateContext"];
+#[cfg(feature = "internal")]
+pub const LATE_LINT_PASS: [&str; 3] = ["rustc_lint", "passes", "LateLintPass"];
+#[cfg(feature = "internal")]
+pub const LINT: [&str; 2] = ["rustc_lint_defs", "Lint"];
++pub const MEM_SWAP: [&str; 3] = ["core", "mem", "swap"];
+pub const MUTEX_GUARD: [&str; 4] = ["std", "sync", "mutex", "MutexGuard"];
+pub const OPEN_OPTIONS: [&str; 3] = ["std", "fs", "OpenOptions"];
+/// Preferably use the diagnostic item `sym::Option` where possible
+pub const OPTION: [&str; 3] = ["core", "option", "Option"];
+pub const OPTION_NONE: [&str; 4] = ["core", "option", "Option", "None"];
+pub const OPTION_SOME: [&str; 4] = ["core", "option", "Option", "Some"];
+pub const ORD: [&str; 3] = ["core", "cmp", "Ord"];
+pub const OS_STRING_AS_OS_STR: [&str; 5] = ["std", "ffi", "os_str", "OsString", "as_os_str"];
+pub const OS_STR_TO_OS_STRING: [&str; 5] = ["std", "ffi", "os_str", "OsStr", "to_os_string"];
+pub const PARKING_LOT_RAWMUTEX: [&str; 3] = ["parking_lot", "raw_mutex", "RawMutex"];
+pub const PARKING_LOT_RAWRWLOCK: [&str; 3] = ["parking_lot", "raw_rwlock", "RawRwLock"];
+pub const PARKING_LOT_MUTEX_GUARD: [&str; 3] = ["lock_api", "mutex", "MutexGuard"];
+pub const PARKING_LOT_RWLOCK_READ_GUARD: [&str; 3] = ["lock_api", "rwlock", "RwLockReadGuard"];
+pub const PARKING_LOT_RWLOCK_WRITE_GUARD: [&str; 3] = ["lock_api", "rwlock", "RwLockWriteGuard"];
+pub const PATH_BUF_AS_PATH: [&str; 4] = ["std", "path", "PathBuf", "as_path"];
+pub const PATH_TO_PATH_BUF: [&str; 4] = ["std", "path", "Path", "to_path_buf"];
+pub const PERMISSIONS: [&str; 3] = ["std", "fs", "Permissions"];
+#[cfg_attr(not(unix), allow(clippy::invalid_paths))]
+pub const PERMISSIONS_FROM_MODE: [&str; 6] = ["std", "os", "unix", "fs", "PermissionsExt", "from_mode"];
+pub const POLL: [&str; 4] = ["core", "task", "poll", "Poll"];
+pub const POLL_PENDING: [&str; 5] = ["core", "task", "poll", "Poll", "Pending"];
+pub const POLL_READY: [&str; 5] = ["core", "task", "poll", "Poll", "Ready"];
+pub const PTR_COPY: [&str; 3] = ["core", "intrinsics", "copy"];
+pub const PTR_COPY_NONOVERLAPPING: [&str; 3] = ["core", "intrinsics", "copy_nonoverlapping"];
+pub const PTR_EQ: [&str; 3] = ["core", "ptr", "eq"];
+pub const PTR_SLICE_FROM_RAW_PARTS: [&str; 3] = ["core", "ptr", "slice_from_raw_parts"];
+pub const PTR_SLICE_FROM_RAW_PARTS_MUT: [&str; 3] = ["core", "ptr", "slice_from_raw_parts_mut"];
+pub const PTR_SWAP_NONOVERLAPPING: [&str; 3] = ["core", "ptr", "swap_nonoverlapping"];
+pub const PTR_READ: [&str; 3] = ["core", "ptr", "read"];
+pub const PTR_READ_UNALIGNED: [&str; 3] = ["core", "ptr", "read_unaligned"];
+pub const PTR_READ_VOLATILE: [&str; 3] = ["core", "ptr", "read_volatile"];
+pub const PTR_REPLACE: [&str; 3] = ["core", "ptr", "replace"];
+pub const PTR_SWAP: [&str; 3] = ["core", "ptr", "swap"];
+pub const PTR_UNALIGNED_VOLATILE_LOAD: [&str; 3] = ["core", "intrinsics", "unaligned_volatile_load"];
+pub const PTR_UNALIGNED_VOLATILE_STORE: [&str; 3] = ["core", "intrinsics", "unaligned_volatile_store"];
+pub const PTR_WRITE: [&str; 3] = ["core", "ptr", "write"];
+pub const PTR_WRITE_BYTES: [&str; 3] = ["core", "intrinsics", "write_bytes"];
+pub const PTR_WRITE_UNALIGNED: [&str; 3] = ["core", "ptr", "write_unaligned"];
+pub const PTR_WRITE_VOLATILE: [&str; 3] = ["core", "ptr", "write_volatile"];
+pub const PUSH_STR: [&str; 4] = ["alloc", "string", "String", "push_str"];
+pub const RANGE_ARGUMENT_TRAIT: [&str; 3] = ["core", "ops", "RangeBounds"];
+pub const RC_PTR_EQ: [&str; 4] = ["alloc", "rc", "Rc", "ptr_eq"];
+pub const REFCELL_REF: [&str; 3] = ["core", "cell", "Ref"];
+pub const REFCELL_REFMUT: [&str; 3] = ["core", "cell", "RefMut"];
+#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
+pub const REGEX_BUILDER_NEW: [&str; 5] = ["regex", "re_builder", "unicode", "RegexBuilder", "new"];
+#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
+pub const REGEX_BYTES_BUILDER_NEW: [&str; 5] = ["regex", "re_builder", "bytes", "RegexBuilder", "new"];
+#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
+pub const REGEX_BYTES_NEW: [&str; 4] = ["regex", "re_bytes", "Regex", "new"];
+#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
+pub const REGEX_BYTES_SET_NEW: [&str; 5] = ["regex", "re_set", "bytes", "RegexSet", "new"];
+#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
+pub const REGEX_NEW: [&str; 4] = ["regex", "re_unicode", "Regex", "new"];
+#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
+pub const REGEX_SET_NEW: [&str; 5] = ["regex", "re_set", "unicode", "RegexSet", "new"];
+/// Preferably use the diagnostic item `sym::Result` where possible
+pub const RESULT: [&str; 3] = ["core", "result", "Result"];
+pub const RESULT_ERR: [&str; 4] = ["core", "result", "Result", "Err"];
+pub const RESULT_OK: [&str; 4] = ["core", "result", "Result", "Ok"];
+#[cfg(feature = "internal")]
+pub const RUSTC_VERSION: [&str; 2] = ["rustc_semver", "RustcVersion"];
+pub const RWLOCK_READ_GUARD: [&str; 4] = ["std", "sync", "rwlock", "RwLockReadGuard"];
+pub const RWLOCK_WRITE_GUARD: [&str; 4] = ["std", "sync", "rwlock", "RwLockWriteGuard"];
+pub const SERDE_DESERIALIZE: [&str; 3] = ["serde", "de", "Deserialize"];
+pub const SERDE_DE_VISITOR: [&str; 3] = ["serde", "de", "Visitor"];
+pub const SLICE_FROM_RAW_PARTS: [&str; 4] = ["core", "slice", "raw", "from_raw_parts"];
+pub const SLICE_FROM_RAW_PARTS_MUT: [&str; 4] = ["core", "slice", "raw", "from_raw_parts_mut"];
++pub const SLICE_GET: [&str; 4] = ["core", "slice", "<impl [T]>", "get"];
+pub const SLICE_INTO_VEC: [&str; 4] = ["alloc", "slice", "<impl [T]>", "into_vec"];
+pub const SLICE_ITER: [&str; 4] = ["core", "slice", "iter", "Iter"];
+pub const STDERR: [&str; 4] = ["std", "io", "stdio", "stderr"];
+pub const STDOUT: [&str; 4] = ["std", "io", "stdio", "stdout"];
+pub const CONVERT_IDENTITY: [&str; 3] = ["core", "convert", "identity"];
+pub const STD_FS_CREATE_DIR: [&str; 3] = ["std", "fs", "create_dir"];
+pub const STRING_AS_MUT_STR: [&str; 4] = ["alloc", "string", "String", "as_mut_str"];
+pub const STRING_AS_STR: [&str; 4] = ["alloc", "string", "String", "as_str"];
+pub const STRING_NEW: [&str; 4] = ["alloc", "string", "String", "new"];
+pub const STR_BYTES: [&str; 4] = ["core", "str", "<impl str>", "bytes"];
+pub const STR_ENDS_WITH: [&str; 4] = ["core", "str", "<impl str>", "ends_with"];
+pub const STR_FROM_UTF8: [&str; 4] = ["core", "str", "converts", "from_utf8"];
+pub const STR_LEN: [&str; 4] = ["core", "str", "<impl str>", "len"];
+pub const STR_STARTS_WITH: [&str; 4] = ["core", "str", "<impl str>", "starts_with"];
+#[cfg(feature = "internal")]
+pub const SYMBOL: [&str; 3] = ["rustc_span", "symbol", "Symbol"];
+#[cfg(feature = "internal")]
+pub const SYMBOL_AS_STR: [&str; 4] = ["rustc_span", "symbol", "Symbol", "as_str"];
+#[cfg(feature = "internal")]
+pub const SYMBOL_INTERN: [&str; 4] = ["rustc_span", "symbol", "Symbol", "intern"];
+#[cfg(feature = "internal")]
+pub const SYMBOL_TO_IDENT_STRING: [&str; 4] = ["rustc_span", "symbol", "Symbol", "to_ident_string"];
+#[cfg(feature = "internal")]
+pub const SYM_MODULE: [&str; 3] = ["rustc_span", "symbol", "sym"];
+#[cfg(feature = "internal")]
+pub const SYNTAX_CONTEXT: [&str; 3] = ["rustc_span", "hygiene", "SyntaxContext"];
+pub const TO_OWNED_METHOD: [&str; 4] = ["alloc", "borrow", "ToOwned", "to_owned"];
+pub const TO_STRING_METHOD: [&str; 4] = ["alloc", "string", "ToString", "to_string"];
+#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
+pub const TOKIO_IO_ASYNCREADEXT: [&str; 5] = ["tokio", "io", "util", "async_read_ext", "AsyncReadExt"];
+#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
+pub const TOKIO_IO_ASYNCWRITEEXT: [&str; 5] = ["tokio", "io", "util", "async_write_ext", "AsyncWriteExt"];
+pub const TRY_FROM: [&str; 4] = ["core", "convert", "TryFrom", "try_from"];
+pub const VEC_AS_MUT_SLICE: [&str; 4] = ["alloc", "vec", "Vec", "as_mut_slice"];
+pub const VEC_AS_SLICE: [&str; 4] = ["alloc", "vec", "Vec", "as_slice"];
+pub const VEC_FROM_ELEM: [&str; 3] = ["alloc", "vec", "from_elem"];
+pub const VEC_NEW: [&str; 4] = ["alloc", "vec", "Vec", "new"];
+pub const VEC_RESIZE: [&str; 4] = ["alloc", "vec", "Vec", "resize"];
+pub const WEAK_ARC: [&str; 3] = ["alloc", "sync", "Weak"];
+pub const WEAK_RC: [&str; 3] = ["alloc", "rc", "Weak"];
+pub const PTR_NON_NULL: [&str; 4] = ["core", "ptr", "non_null", "NonNull"];
--- /dev/null
- Rvalue::Repeat(operand, _) | Rvalue::Use(operand) => check_operand(tcx, operand, span, body),
+// This code used to be a part of `rustc` but moved to Clippy as a result of
+// https://github.com/rust-lang/rust/issues/76618. Because of that, it contains unused code and some
+// of terminologies might not be relevant in the context of Clippy. Note that its behavior might
+// differ from the time of `rustc` even if the name stays the same.
+
+use rustc_hir as hir;
+use rustc_hir::def_id::DefId;
+use rustc_middle::mir::{
+ Body, CastKind, NullOp, Operand, Place, ProjectionElem, Rvalue, Statement, StatementKind, Terminator,
+ TerminatorKind,
+};
+use rustc_middle::ty::subst::GenericArgKind;
+use rustc_middle::ty::{self, adjustment::PointerCast, Ty, TyCtxt};
+use rustc_semver::RustcVersion;
+use rustc_span::symbol::sym;
+use rustc_span::Span;
+use std::borrow::Cow;
+
+type McfResult = Result<(), (Span, Cow<'static, str>)>;
+
+pub fn is_min_const_fn<'a, 'tcx>(tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, msrv: Option<RustcVersion>) -> McfResult {
+ let def_id = body.source.def_id();
+ let mut current = def_id;
+ loop {
+ let predicates = tcx.predicates_of(current);
+ for (predicate, _) in predicates.predicates {
+ match predicate.kind().skip_binder() {
+ ty::PredicateKind::RegionOutlives(_)
+ | ty::PredicateKind::TypeOutlives(_)
+ | ty::PredicateKind::WellFormed(_)
+ | ty::PredicateKind::Projection(_)
+ | ty::PredicateKind::ConstEvaluatable(..)
+ | ty::PredicateKind::ConstEquate(..)
+ | ty::PredicateKind::Trait(..)
+ | ty::PredicateKind::TypeWellFormedFromEnv(..) => continue,
+ ty::PredicateKind::ObjectSafe(_) => panic!("object safe predicate on function: {:#?}", predicate),
+ ty::PredicateKind::ClosureKind(..) => panic!("closure kind predicate on function: {:#?}", predicate),
+ ty::PredicateKind::Subtype(_) => panic!("subtype predicate on function: {:#?}", predicate),
+ ty::PredicateKind::Coerce(_) => panic!("coerce predicate on function: {:#?}", predicate),
+ }
+ }
+ match predicates.parent {
+ Some(parent) => current = parent,
+ None => break,
+ }
+ }
+
+ for local in &body.local_decls {
+ check_ty(tcx, local.ty, local.source_info.span)?;
+ }
+ // impl trait is gone in MIR, so check the return type manually
+ check_ty(
+ tcx,
+ tcx.fn_sig(def_id).output().skip_binder(),
+ body.local_decls.iter().next().unwrap().source_info.span,
+ )?;
+
+ for bb in body.basic_blocks() {
+ check_terminator(tcx, body, bb.terminator(), msrv)?;
+ for stmt in &bb.statements {
+ check_statement(tcx, body, def_id, stmt)?;
+ }
+ }
+ Ok(())
+}
+
+fn check_ty<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, span: Span) -> McfResult {
+ for arg in ty.walk() {
+ let ty = match arg.unpack() {
+ GenericArgKind::Type(ty) => ty,
+
+ // No constraints on lifetimes or constants, except potentially
+ // constants' types, but `walk` will get to them as well.
+ GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => continue,
+ };
+
+ match ty.kind() {
+ ty::Ref(_, _, hir::Mutability::Mut) => {
+ return Err((span, "mutable references in const fn are unstable".into()));
+ },
+ ty::Opaque(..) => return Err((span, "`impl Trait` in const fn is unstable".into())),
+ ty::FnPtr(..) => {
+ return Err((span, "function pointers in const fn are unstable".into()));
+ },
+ ty::Dynamic(preds, _) => {
+ for pred in preds.iter() {
+ match pred.skip_binder() {
+ ty::ExistentialPredicate::AutoTrait(_) | ty::ExistentialPredicate::Projection(_) => {
+ return Err((
+ span,
+ "trait bounds other than `Sized` \
+ on const fn parameters are unstable"
+ .into(),
+ ));
+ },
+ ty::ExistentialPredicate::Trait(trait_ref) => {
+ if Some(trait_ref.def_id) != tcx.lang_items().sized_trait() {
+ return Err((
+ span,
+ "trait bounds other than `Sized` \
+ on const fn parameters are unstable"
+ .into(),
+ ));
+ }
+ },
+ }
+ }
+ },
+ _ => {},
+ }
+ }
+ Ok(())
+}
+
+fn check_rvalue<'tcx>(
+ tcx: TyCtxt<'tcx>,
+ body: &Body<'tcx>,
+ def_id: DefId,
+ rvalue: &Rvalue<'tcx>,
+ span: Span,
+) -> McfResult {
+ match rvalue {
+ Rvalue::ThreadLocalRef(_) => Err((span, "cannot access thread local storage in const fn".into())),
- Rvalue::Cast(CastKind::PointerExposeAddress, _, _) => {
- Err((span, "casting pointers to ints is unstable in const fn".into()))
- },
- Rvalue::Cast(CastKind::Misc, operand, _) => {
- check_operand(tcx, operand, span, body)
- },
- Rvalue::Cast(
+ Rvalue::Len(place) | Rvalue::Discriminant(place) | Rvalue::Ref(_, _, place) | Rvalue::AddressOf(_, place) => {
+ check_place(tcx, *place, span, body)
+ },
- _
- ) => {
- check_operand(tcx, operand, span, body)
- },
++ Rvalue::Repeat(operand, _)
++ | Rvalue::Use(operand)
++ | Rvalue::Cast(
+ CastKind::PointerFromExposedAddress
++ | CastKind::Misc
+ | CastKind::Pointer(PointerCast::MutToConstPointer | PointerCast::ArrayToPointer),
+ operand,
++ _,
++ ) => check_operand(tcx, operand, span, body),
+ Rvalue::Cast(
+ CastKind::Pointer(
+ PointerCast::UnsafeFnPointer | PointerCast::ClosureFnPointer(_) | PointerCast::ReifyFnPointer,
+ ),
+ _,
+ _,
+ ) => Err((span, "function pointer casts are not allowed in const fn".into())),
+ Rvalue::Cast(CastKind::Pointer(PointerCast::Unsize), op, cast_ty) => {
+ let pointee_ty = if let Some(deref_ty) = cast_ty.builtin_deref(true) {
+ deref_ty.ty
+ } else {
+ // We cannot allow this for now.
+ return Err((span, "unsizing casts are only allowed for references right now".into()));
+ };
+ let unsized_ty = tcx.struct_tail_erasing_lifetimes(pointee_ty, tcx.param_env(def_id));
+ if let ty::Slice(_) | ty::Str = unsized_ty.kind() {
+ check_operand(tcx, op, span, body)?;
+ // Casting/coercing things to slices is fine.
+ Ok(())
+ } else {
+ // We just can't allow trait objects until we have figured out trait method calls.
+ Err((span, "unsizing casts are not allowed in const fn".into()))
+ }
+ },
++ Rvalue::Cast(CastKind::PointerExposeAddress, _, _) => {
++ Err((span, "casting pointers to ints is unstable in const fn".into()))
++ },
+ // binops are fine on integers
+ Rvalue::BinaryOp(_, box (lhs, rhs)) | Rvalue::CheckedBinaryOp(_, box (lhs, rhs)) => {
+ check_operand(tcx, lhs, span, body)?;
+ check_operand(tcx, rhs, span, body)?;
+ let ty = lhs.ty(body, tcx);
+ if ty.is_integral() || ty.is_bool() || ty.is_char() {
+ Ok(())
+ } else {
+ Err((
+ span,
+ "only int, `bool` and `char` operations are stable in const fn".into(),
+ ))
+ }
+ },
+ Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf, _) | Rvalue::ShallowInitBox(_, _) => Ok(()),
+ Rvalue::UnaryOp(_, operand) => {
+ let ty = operand.ty(body, tcx);
+ if ty.is_integral() || ty.is_bool() {
+ check_operand(tcx, operand, span, body)
+ } else {
+ Err((span, "only int and `bool` operations are stable in const fn".into()))
+ }
+ },
+ Rvalue::Aggregate(_, operands) => {
+ for operand in operands {
+ check_operand(tcx, operand, span, body)?;
+ }
+ Ok(())
+ },
+ }
+}
+
+fn check_statement<'tcx>(
+ tcx: TyCtxt<'tcx>,
+ body: &Body<'tcx>,
+ def_id: DefId,
+ statement: &Statement<'tcx>,
+) -> McfResult {
+ let span = statement.source_info.span;
+ match &statement.kind {
+ StatementKind::Assign(box (place, rval)) => {
+ check_place(tcx, *place, span, body)?;
+ check_rvalue(tcx, body, def_id, rval, span)
+ },
+
+ StatementKind::FakeRead(box (_, place)) => check_place(tcx, *place, span, body),
+ // just an assignment
+ StatementKind::SetDiscriminant { place, .. } | StatementKind::Deinit(place) => {
+ check_place(tcx, **place, span, body)
+ },
+
+ StatementKind::CopyNonOverlapping(box rustc_middle::mir::CopyNonOverlapping { dst, src, count }) => {
+ check_operand(tcx, dst, span, body)?;
+ check_operand(tcx, src, span, body)?;
+ check_operand(tcx, count, span, body)
+ },
+ // These are all NOPs
+ StatementKind::StorageLive(_)
+ | StatementKind::StorageDead(_)
+ | StatementKind::Retag { .. }
+ | StatementKind::AscribeUserType(..)
+ | StatementKind::Coverage(..)
+ | StatementKind::Nop => Ok(()),
+ }
+}
+
+fn check_operand<'tcx>(tcx: TyCtxt<'tcx>, operand: &Operand<'tcx>, span: Span, body: &Body<'tcx>) -> McfResult {
+ match operand {
+ Operand::Move(place) | Operand::Copy(place) => check_place(tcx, *place, span, body),
+ Operand::Constant(c) => match c.check_static_ptr(tcx) {
+ Some(_) => Err((span, "cannot access `static` items in const fn".into())),
+ None => Ok(()),
+ },
+ }
+}
+
+fn check_place<'tcx>(tcx: TyCtxt<'tcx>, place: Place<'tcx>, span: Span, body: &Body<'tcx>) -> McfResult {
+ let mut cursor = place.projection.as_ref();
+ while let [ref proj_base @ .., elem] = *cursor {
+ cursor = proj_base;
+ match elem {
+ ProjectionElem::Field(..) => {
+ let base_ty = Place::ty_from(place.local, proj_base, body, tcx).ty;
+ if let Some(def) = base_ty.ty_adt_def() {
+ // No union field accesses in `const fn`
+ if def.is_union() {
+ return Err((span, "accessing union fields is unstable".into()));
+ }
+ }
+ },
+ ProjectionElem::ConstantIndex { .. }
+ | ProjectionElem::Downcast(..)
+ | ProjectionElem::Subslice { .. }
+ | ProjectionElem::Deref
+ | ProjectionElem::Index(_) => {},
+ }
+ }
+
+ Ok(())
+}
+
+fn check_terminator<'a, 'tcx>(
+ tcx: TyCtxt<'tcx>,
+ body: &'a Body<'tcx>,
+ terminator: &Terminator<'tcx>,
+ msrv: Option<RustcVersion>,
+) -> McfResult {
+ let span = terminator.source_info.span;
+ match &terminator.kind {
+ TerminatorKind::FalseEdge { .. }
+ | TerminatorKind::FalseUnwind { .. }
+ | TerminatorKind::Goto { .. }
+ | TerminatorKind::Return
+ | TerminatorKind::Resume
+ | TerminatorKind::Unreachable => Ok(()),
+
+ TerminatorKind::Drop { place, .. } => check_place(tcx, *place, span, body),
+ TerminatorKind::DropAndReplace { place, value, .. } => {
+ check_place(tcx, *place, span, body)?;
+ check_operand(tcx, value, span, body)
+ },
+
+ TerminatorKind::SwitchInt {
+ discr,
+ switch_ty: _,
+ targets: _,
+ } => check_operand(tcx, discr, span, body),
+
+ TerminatorKind::Abort => Err((span, "abort is not stable in const fn".into())),
+ TerminatorKind::GeneratorDrop | TerminatorKind::Yield { .. } => {
+ Err((span, "const fn generators are unstable".into()))
+ },
+
+ TerminatorKind::Call {
+ func,
+ args,
+ from_hir_call: _,
+ destination: _,
+ target: _,
+ cleanup: _,
+ fn_span: _,
+ } => {
+ let fn_ty = func.ty(body, tcx);
+ if let ty::FnDef(fn_def_id, _) = *fn_ty.kind() {
+ if !is_const_fn(tcx, fn_def_id, msrv) {
+ return Err((
+ span,
+ format!(
+ "can only call other `const fn` within a `const fn`, \
+ but `{:?}` is not stable as `const fn`",
+ func,
+ )
+ .into(),
+ ));
+ }
+
+ // HACK: This is to "unstabilize" the `transmute` intrinsic
+ // within const fns. `transmute` is allowed in all other const contexts.
+ // This won't really scale to more intrinsics or functions. Let's allow const
+ // transmutes in const fn before we add more hacks to this.
+ if tcx.is_intrinsic(fn_def_id) && tcx.item_name(fn_def_id) == sym::transmute {
+ return Err((
+ span,
+ "can only call `transmute` from const items, not `const fn`".into(),
+ ));
+ }
+
+ check_operand(tcx, func, span, body)?;
+
+ for arg in args {
+ check_operand(tcx, arg, span, body)?;
+ }
+ Ok(())
+ } else {
+ Err((span, "can only call other const fns within const fn".into()))
+ }
+ },
+
+ TerminatorKind::Assert {
+ cond,
+ expected: _,
+ msg: _,
+ target: _,
+ cleanup: _,
+ } => check_operand(tcx, cond, span, body),
+
+ TerminatorKind::InlineAsm { .. } => Err((span, "cannot use inline assembly in const fn".into())),
+ }
+}
+
+fn is_const_fn(tcx: TyCtxt<'_>, def_id: DefId, msrv: Option<RustcVersion>) -> bool {
+ tcx.is_const_fn(def_id)
+ && tcx.lookup_const_stability(def_id).map_or(true, |const_stab| {
+ if let rustc_attr::StabilityLevel::Stable { since } = const_stab.level {
+ // Checking MSRV is manually necessary because `rustc` has no such concept. This entire
+ // function could be removed if `rustc` provided a MSRV-aware version of `is_const_fn`.
+ // as a part of an unimplemented MSRV check https://github.com/rust-lang/rust/issues/65262.
+ crate::meets_msrv(
+ msrv,
+ RustcVersion::parse(since.as_str())
+ .expect("`rustc_attr::StabilityLevel::Stable::since` is ill-formatted"),
+ )
+ } else {
+ // Unstable const fn with the feature enabled.
+ msrv.is_none()
+ }
+ })
+}
--- /dev/null
- use rustc_span::{BytePos, Pos, Span, SyntaxContext};
+//! Utils for extracting, inspecting or transforming source code
+
+#![allow(clippy::module_name_repetitions)]
+
+use crate::line_span;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LintContext};
+use rustc_span::hygiene;
+use rustc_span::source_map::SourceMap;
++use rustc_span::{BytePos, Pos, Span, SpanData, SyntaxContext};
+use std::borrow::Cow;
+
+/// Checks if the span starts with the given text. This will return false if the span crosses
+/// multiple files or if source is not available.
+///
+/// This is used to check for proc macros giving unhelpful spans to things.
+pub fn span_starts_with<T: LintContext>(cx: &T, span: Span, text: &str) -> bool {
+ fn helper(sm: &SourceMap, span: Span, text: &str) -> bool {
+ let pos = sm.lookup_byte_offset(span.lo());
+ let Some(ref src) = pos.sf.src else {
+ return false;
+ };
+ let end = span.hi() - pos.sf.start_pos;
+ src.get(pos.pos.0 as usize..end.0 as usize)
+ // Expression spans can include wrapping parenthesis. Remove them first.
+ .map_or(false, |s| s.trim_start_matches('(').starts_with(text))
+ }
+ helper(cx.sess().source_map(), span, text)
+}
+
+/// Like `snippet_block`, but add braces if the expr is not an `ExprKind::Block`.
+/// Also takes an `Option<String>` which can be put inside the braces.
+pub fn expr_block<'a, T: LintContext>(
+ cx: &T,
+ expr: &Expr<'_>,
+ option: Option<String>,
+ default: &'a str,
+ indent_relative_to: Option<Span>,
+) -> Cow<'a, str> {
+ let code = snippet_block(cx, expr.span, default, indent_relative_to);
+ let string = option.unwrap_or_default();
+ if expr.span.from_expansion() {
+ Cow::Owned(format!("{{ {} }}", snippet_with_macro_callsite(cx, expr.span, default)))
+ } else if let ExprKind::Block(_, _) = expr.kind {
+ Cow::Owned(format!("{}{}", code, string))
+ } else if string.is_empty() {
+ Cow::Owned(format!("{{ {} }}", code))
+ } else {
+ Cow::Owned(format!("{{\n{};\n{}\n}}", code, string))
+ }
+}
+
+/// Returns a new Span that extends the original Span to the first non-whitespace char of the first
+/// line.
+///
+/// ```rust,ignore
+/// let x = ();
+/// // ^^
+/// // will be converted to
+/// let x = ();
+/// // ^^^^^^^^^^
+/// ```
+pub fn first_line_of_span<T: LintContext>(cx: &T, span: Span) -> Span {
+ first_char_in_first_line(cx, span).map_or(span, |first_char_pos| span.with_lo(first_char_pos))
+}
+
+fn first_char_in_first_line<T: LintContext>(cx: &T, span: Span) -> Option<BytePos> {
+ let line_span = line_span(cx, span);
+ snippet_opt(cx, line_span).and_then(|snip| {
+ snip.find(|c: char| !c.is_whitespace())
+ .map(|pos| line_span.lo() + BytePos::from_usize(pos))
+ })
+}
+
+/// Returns the indentation of the line of a span
+///
+/// ```rust,ignore
+/// let x = ();
+/// // ^^ -- will return 0
+/// let x = ();
+/// // ^^ -- will return 4
+/// ```
+pub fn indent_of<T: LintContext>(cx: &T, span: Span) -> Option<usize> {
+ snippet_opt(cx, line_span(cx, span)).and_then(|snip| snip.find(|c: char| !c.is_whitespace()))
+}
+
+/// Gets a snippet of the indentation of the line of a span
+pub fn snippet_indent<T: LintContext>(cx: &T, span: Span) -> Option<String> {
+ snippet_opt(cx, line_span(cx, span)).map(|mut s| {
+ let len = s.len() - s.trim_start().len();
+ s.truncate(len);
+ s
+ })
+}
+
+// If the snippet is empty, it's an attribute that was inserted during macro
+// expansion and we want to ignore those, because they could come from external
+// sources that the user has no control over.
+// For some reason these attributes don't have any expansion info on them, so
+// we have to check it this way until there is a better way.
+pub fn is_present_in_source<T: LintContext>(cx: &T, span: Span) -> bool {
+ if let Some(snippet) = snippet_opt(cx, span) {
+ if snippet.is_empty() {
+ return false;
+ }
+ }
+ true
+}
+
+/// Returns the position just before rarrow
+///
+/// ```rust,ignore
+/// fn into(self) -> () {}
+/// ^
+/// // in case of unformatted code
+/// fn into2(self)-> () {}
+/// ^
+/// fn into3(self) -> () {}
+/// ^
+/// ```
+pub fn position_before_rarrow(s: &str) -> Option<usize> {
+ s.rfind("->").map(|rpos| {
+ let mut rpos = rpos;
+ let chars: Vec<char> = s.chars().collect();
+ while rpos > 1 {
+ if let Some(c) = chars.get(rpos - 1) {
+ if c.is_whitespace() {
+ rpos -= 1;
+ continue;
+ }
+ }
+ break;
+ }
+ rpos
+ })
+}
+
+/// Reindent a multiline string with possibility of ignoring the first line.
+#[expect(clippy::needless_pass_by_value)]
+pub fn reindent_multiline(s: Cow<'_, str>, ignore_first: bool, indent: Option<usize>) -> Cow<'_, str> {
+ let s_space = reindent_multiline_inner(&s, ignore_first, indent, ' ');
+ let s_tab = reindent_multiline_inner(&s_space, ignore_first, indent, '\t');
+ reindent_multiline_inner(&s_tab, ignore_first, indent, ' ').into()
+}
+
+fn reindent_multiline_inner(s: &str, ignore_first: bool, indent: Option<usize>, ch: char) -> String {
+ let x = s
+ .lines()
+ .skip(usize::from(ignore_first))
+ .filter_map(|l| {
+ if l.is_empty() {
+ None
+ } else {
+ // ignore empty lines
+ Some(l.char_indices().find(|&(_, x)| x != ch).unwrap_or((l.len(), ch)).0)
+ }
+ })
+ .min()
+ .unwrap_or(0);
+ let indent = indent.unwrap_or(0);
+ s.lines()
+ .enumerate()
+ .map(|(i, l)| {
+ if (ignore_first && i == 0) || l.is_empty() {
+ l.to_owned()
+ } else if x > indent {
+ l.split_at(x - indent).1.to_owned()
+ } else {
+ " ".repeat(indent - x) + l
+ }
+ })
+ .collect::<Vec<String>>()
+ .join("\n")
+}
+
+/// Converts a span to a code snippet if available, otherwise returns the default.
+///
+/// This is useful if you want to provide suggestions for your lint or more generally, if you want
+/// to convert a given `Span` to a `str`. To create suggestions consider using
+/// [`snippet_with_applicability`] to ensure that the applicability stays correct.
+///
+/// # Example
+/// ```rust,ignore
+/// // Given two spans one for `value` and one for the `init` expression.
+/// let value = Vec::new();
+/// // ^^^^^ ^^^^^^^^^^
+/// // span1 span2
+///
+/// // The snipped call would return the corresponding code snippet
+/// snippet(cx, span1, "..") // -> "value"
+/// snippet(cx, span2, "..") // -> "Vec::new()"
+/// ```
+pub fn snippet<'a, T: LintContext>(cx: &T, span: Span, default: &'a str) -> Cow<'a, str> {
+ snippet_opt(cx, span).map_or_else(|| Cow::Borrowed(default), From::from)
+}
+
+/// Same as [`snippet`], but it adapts the applicability level by following rules:
+///
+/// - Applicability level `Unspecified` will never be changed.
+/// - If the span is inside a macro, change the applicability level to `MaybeIncorrect`.
+/// - If the default value is used and the applicability level is `MachineApplicable`, change it to
+/// `HasPlaceholders`
+pub fn snippet_with_applicability<'a, T: LintContext>(
+ cx: &T,
+ span: Span,
+ default: &'a str,
+ applicability: &mut Applicability,
+) -> Cow<'a, str> {
+ if *applicability != Applicability::Unspecified && span.from_expansion() {
+ *applicability = Applicability::MaybeIncorrect;
+ }
+ snippet_opt(cx, span).map_or_else(
+ || {
+ if *applicability == Applicability::MachineApplicable {
+ *applicability = Applicability::HasPlaceholders;
+ }
+ Cow::Borrowed(default)
+ },
+ From::from,
+ )
+}
+
+/// Same as `snippet`, but should only be used when it's clear that the input span is
+/// not a macro argument.
+pub fn snippet_with_macro_callsite<'a, T: LintContext>(cx: &T, span: Span, default: &'a str) -> Cow<'a, str> {
+ snippet(cx, span.source_callsite(), default)
+}
+
+/// Converts a span to a code snippet. Returns `None` if not available.
+pub fn snippet_opt<T: LintContext>(cx: &T, span: Span) -> Option<String> {
+ cx.sess().source_map().span_to_snippet(span).ok()
+}
+
+/// Converts a span (from a block) to a code snippet if available, otherwise use default.
+///
+/// This trims the code of indentation, except for the first line. Use it for blocks or block-like
+/// things which need to be printed as such.
+///
+/// The `indent_relative_to` arg can be used, to provide a span, where the indentation of the
+/// resulting snippet of the given span.
+///
+/// # Example
+///
+/// ```rust,ignore
+/// snippet_block(cx, block.span, "..", None)
+/// // where, `block` is the block of the if expr
+/// if x {
+/// y;
+/// }
+/// // will return the snippet
+/// {
+/// y;
+/// }
+/// ```
+///
+/// ```rust,ignore
+/// snippet_block(cx, block.span, "..", Some(if_expr.span))
+/// // where, `block` is the block of the if expr
+/// if x {
+/// y;
+/// }
+/// // will return the snippet
+/// {
+/// y;
+/// } // aligned with `if`
+/// ```
+/// Note that the first line of the snippet always has 0 indentation.
+pub fn snippet_block<'a, T: LintContext>(
+ cx: &T,
+ span: Span,
+ default: &'a str,
+ indent_relative_to: Option<Span>,
+) -> Cow<'a, str> {
+ let snip = snippet(cx, span, default);
+ let indent = indent_relative_to.and_then(|s| indent_of(cx, s));
+ reindent_multiline(snip, true, indent)
+}
+
+/// Same as `snippet_block`, but adapts the applicability level by the rules of
+/// `snippet_with_applicability`.
+pub fn snippet_block_with_applicability<'a, T: LintContext>(
+ cx: &T,
+ span: Span,
+ default: &'a str,
+ indent_relative_to: Option<Span>,
+ applicability: &mut Applicability,
+) -> Cow<'a, str> {
+ let snip = snippet_with_applicability(cx, span, default, applicability);
+ let indent = indent_relative_to.and_then(|s| indent_of(cx, s));
+ reindent_multiline(snip, true, indent)
+}
+
+/// Same as `snippet_with_applicability`, but first walks the span up to the given context. This
+/// will result in the macro call, rather then the expansion, if the span is from a child context.
+/// If the span is not from a child context, it will be used directly instead.
+///
+/// e.g. Given the expression `&vec![]`, getting a snippet from the span for `vec![]` as a HIR node
+/// would result in `box []`. If given the context of the address of expression, this function will
+/// correctly get a snippet of `vec![]`.
+///
+/// This will also return whether or not the snippet is a macro call.
+pub fn snippet_with_context<'a>(
+ cx: &LateContext<'_>,
+ span: Span,
+ outer: SyntaxContext,
+ default: &'a str,
+ applicability: &mut Applicability,
+) -> (Cow<'a, str>, bool) {
+ let (span, is_macro_call) = walk_span_to_context(span, outer).map_or_else(
+ || {
+ // The span is from a macro argument, and the outer context is the macro using the argument
+ if *applicability != Applicability::Unspecified {
+ *applicability = Applicability::MaybeIncorrect;
+ }
+ // TODO: get the argument span.
+ (span, false)
+ },
+ |outer_span| (outer_span, span.ctxt() != outer),
+ );
+
+ (
+ snippet_with_applicability(cx, span, default, applicability),
+ is_macro_call,
+ )
+}
+
+/// Walks the span up to the target context, thereby returning the macro call site if the span is
+/// inside a macro expansion, or the original span if it is not. Note this will return `None` in the
+/// case of the span being in a macro expansion, but the target context is from expanding a macro
+/// argument.
+///
+/// Given the following
+///
+/// ```rust,ignore
+/// macro_rules! m { ($e:expr) => { f($e) }; }
+/// g(m!(0))
+/// ```
+///
+/// If called with a span of the call to `f` and a context of the call to `g` this will return a
+/// span containing `m!(0)`. However, if called with a span of the literal `0` this will give a span
+/// containing `0` as the context is the same as the outer context.
+///
+/// This will traverse through multiple macro calls. Given the following:
+///
+/// ```rust,ignore
+/// macro_rules! m { ($e:expr) => { n!($e, 0) }; }
+/// macro_rules! n { ($e:expr, $f:expr) => { f($e, $f) }; }
+/// g(m!(0))
+/// ```
+///
+/// If called with a span of the call to `f` and a context of the call to `g` this will return a
+/// span containing `m!(0)`.
+pub fn walk_span_to_context(span: Span, outer: SyntaxContext) -> Option<Span> {
+ let outer_span = hygiene::walk_chain(span, outer);
+ (outer_span.ctxt() == outer).then(|| outer_span)
+}
+
+/// Removes block comments from the given `Vec` of lines.
+///
+/// # Examples
+///
+/// ```rust,ignore
+/// without_block_comments(vec!["/*", "foo", "*/"]);
+/// // => vec![]
+///
+/// without_block_comments(vec!["bar", "/*", "foo", "*/"]);
+/// // => vec!["bar"]
+/// ```
+pub fn without_block_comments(lines: Vec<&str>) -> Vec<&str> {
+ let mut without = vec![];
+
+ let mut nest_level = 0;
+
+ for line in lines {
+ if line.contains("/*") {
+ nest_level += 1;
+ continue;
+ } else if line.contains("*/") {
+ nest_level -= 1;
+ continue;
+ }
+
+ if nest_level == 0 {
+ without.push(line);
+ }
+ }
+
+ without
+}
+
++/// Trims the whitespace from the start and the end of the span.
++pub fn trim_span(sm: &SourceMap, span: Span) -> Span {
++ let data = span.data();
++ let sf: &_ = &sm.lookup_source_file(data.lo);
++ let Some(src) = sf.src.as_deref() else {
++ return span;
++ };
++ let Some(snip) = &src.get((data.lo - sf.start_pos).to_usize()..(data.hi - sf.start_pos).to_usize()) else {
++ return span;
++ };
++ let trim_start = snip.len() - snip.trim_start().len();
++ let trim_end = snip.len() - snip.trim_end().len();
++ SpanData {
++ lo: data.lo + BytePos::from_usize(trim_start),
++ hi: data.hi - BytePos::from_usize(trim_end),
++ ctxt: data.ctxt,
++ parent: data.parent,
++ }
++ .span()
++}
++
+#[cfg(test)]
+mod test {
+ use super::{reindent_multiline, without_block_comments};
+
+ #[test]
+ fn test_reindent_multiline_single_line() {
+ assert_eq!("", reindent_multiline("".into(), false, None));
+ assert_eq!("...", reindent_multiline("...".into(), false, None));
+ assert_eq!("...", reindent_multiline(" ...".into(), false, None));
+ assert_eq!("...", reindent_multiline("\t...".into(), false, None));
+ assert_eq!("...", reindent_multiline("\t\t...".into(), false, None));
+ }
+
+ #[test]
+ #[rustfmt::skip]
+ fn test_reindent_multiline_block() {
+ assert_eq!("\
+ if x {
+ y
+ } else {
+ z
+ }", reindent_multiline(" if x {
+ y
+ } else {
+ z
+ }".into(), false, None));
+ assert_eq!("\
+ if x {
+ \ty
+ } else {
+ \tz
+ }", reindent_multiline(" if x {
+ \ty
+ } else {
+ \tz
+ }".into(), false, None));
+ }
+
+ #[test]
+ #[rustfmt::skip]
+ fn test_reindent_multiline_empty_line() {
+ assert_eq!("\
+ if x {
+ y
+
+ } else {
+ z
+ }", reindent_multiline(" if x {
+ y
+
+ } else {
+ z
+ }".into(), false, None));
+ }
+
+ #[test]
+ #[rustfmt::skip]
+ fn test_reindent_multiline_lines_deeper() {
+ assert_eq!("\
+ if x {
+ y
+ } else {
+ z
+ }", reindent_multiline("\
+ if x {
+ y
+ } else {
+ z
+ }".into(), true, Some(8)));
+ }
+
+ #[test]
+ fn test_without_block_comments_lines_without_block_comments() {
+ let result = without_block_comments(vec!["/*", "", "*/"]);
+ println!("result: {:?}", result);
+ assert!(result.is_empty());
+
+ let result = without_block_comments(vec!["", "/*", "", "*/", "#[crate_type = \"lib\"]", "/*", "", "*/", ""]);
+ assert_eq!(result, vec!["", "#[crate_type = \"lib\"]", ""]);
+
+ let result = without_block_comments(vec!["/* rust", "", "*/"]);
+ assert!(result.is_empty());
+
+ let result = without_block_comments(vec!["/* one-line comment */"]);
+ assert!(result.is_empty());
+
+ let result = without_block_comments(vec!["/* nested", "/* multi-line", "comment", "*/", "test", "*/"]);
+ assert!(result.is_empty());
+
+ let result = without_block_comments(vec!["/* nested /* inline /* comment */ test */ */"]);
+ assert!(result.is_empty());
+
+ let result = without_block_comments(vec!["foo", "bar", "baz"]);
+ assert_eq!(result, vec!["foo", "bar", "baz"]);
+ }
+}
--- /dev/null
- self, AdtDef, Binder, FnSig, IntTy, Predicate, PredicateKind, Ty, TyCtxt, TypeFoldable, UintTy, VariantDiscr,
+//! Util methods for [`rustc_middle::ty`]
+
+#![allow(clippy::module_name_repetitions)]
+
+use rustc_ast::ast::Mutability;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_hir as hir;
+use rustc_hir::def::{CtorKind, DefKind, Res};
+use rustc_hir::def_id::DefId;
+use rustc_hir::{Expr, LangItem, TyKind, Unsafety};
+use rustc_infer::infer::TyCtxtInferExt;
+use rustc_lint::LateContext;
+use rustc_middle::mir::interpret::{ConstValue, Scalar};
+use rustc_middle::ty::subst::{GenericArg, GenericArgKind, Subst};
+use rustc_middle::ty::{
- let ty = cx.tcx.erase_regions(ty);
++ self, AdtDef, Binder, FnSig, IntTy, ParamEnv, Predicate, PredicateKind, Ty, TyCtxt, TypeFoldable, UintTy,
++ VariantDiscr,
+};
+use rustc_span::symbol::Ident;
+use rustc_span::{sym, Span, Symbol, DUMMY_SP};
+use rustc_target::abi::{Size, VariantIdx};
+use rustc_trait_selection::infer::InferCtxtExt;
+use rustc_trait_selection::traits::query::normalize::AtExt;
+use std::iter;
+
+use crate::{match_def_path, path_res, paths};
+
+// Checks if the given type implements copy.
+pub fn is_copy<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
+ ty.is_copy_modulo_regions(cx.tcx.at(DUMMY_SP), cx.param_env)
+}
+
+/// Checks whether a type can be partially moved.
+pub fn can_partially_move_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
+ if has_drop(cx, ty) || is_copy(cx, ty) {
+ return false;
+ }
+ match ty.kind() {
+ ty::Param(_) => false,
+ ty::Adt(def, subs) => def.all_fields().any(|f| !is_copy(cx, f.ty(cx.tcx, subs))),
+ _ => true,
+ }
+}
+
+/// Walks into `ty` and returns `true` if any inner type is the same as `other_ty`
+pub fn contains_ty<'tcx>(ty: Ty<'tcx>, other_ty: Ty<'tcx>) -> bool {
+ ty.walk().any(|inner| match inner.unpack() {
+ GenericArgKind::Type(inner_ty) => other_ty == inner_ty,
+ GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
+ })
+}
+
+/// Walks into `ty` and returns `true` if any inner type is an instance of the given adt
+/// constructor.
+pub fn contains_adt_constructor<'tcx>(ty: Ty<'tcx>, adt: AdtDef<'tcx>) -> bool {
+ ty.walk().any(|inner| match inner.unpack() {
+ GenericArgKind::Type(inner_ty) => inner_ty.ty_adt_def() == Some(adt),
+ GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
+ })
+}
+
+/// Resolves `<T as Iterator>::Item` for `T`
+/// Do not invoke without first verifying that the type implements `Iterator`
+pub fn get_iterator_item_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
+ cx.tcx
+ .get_diagnostic_item(sym::Iterator)
+ .and_then(|iter_did| get_associated_type(cx, ty, iter_did, "Item"))
+}
+
+/// Returns the associated type `name` for `ty` as an implementation of `trait_id`.
+/// Do not invoke without first verifying that the type implements the trait.
+pub fn get_associated_type<'tcx>(
+ cx: &LateContext<'tcx>,
+ ty: Ty<'tcx>,
+ trait_id: DefId,
+ name: &str,
+) -> Option<Ty<'tcx>> {
+ cx.tcx
+ .associated_items(trait_id)
+ .find_by_name_and_kind(cx.tcx, Ident::from_str(name), ty::AssocKind::Type, trait_id)
+ .map(|assoc| {
+ let proj = cx.tcx.mk_projection(assoc.def_id, cx.tcx.mk_substs_trait(ty, &[]));
+ cx.tcx.normalize_erasing_regions(cx.param_env, proj)
+ })
+}
+
+/// Get the diagnostic name of a type, e.g. `sym::HashMap`. To check if a type
+/// implements a trait marked with a diagnostic item use [`implements_trait`].
+///
+/// For a further exploitation what diagnostic items are see [diagnostic items] in
+/// rustc-dev-guide.
+///
+/// [Diagnostic Items]: https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-items.html
+pub fn get_type_diagnostic_name(cx: &LateContext<'_>, ty: Ty<'_>) -> Option<Symbol> {
+ match ty.kind() {
+ ty::Adt(adt, _) => cx.tcx.get_diagnostic_name(adt.did()),
+ _ => None,
+ }
+}
+
+/// Returns true if ty has `iter` or `iter_mut` methods
+pub fn has_iter_method(cx: &LateContext<'_>, probably_ref_ty: Ty<'_>) -> Option<Symbol> {
+ // FIXME: instead of this hard-coded list, we should check if `<adt>::iter`
+ // exists and has the desired signature. Unfortunately FnCtxt is not exported
+ // so we can't use its `lookup_method` method.
+ let into_iter_collections: &[Symbol] = &[
+ sym::Vec,
+ sym::Option,
+ sym::Result,
+ sym::BTreeMap,
+ sym::BTreeSet,
+ sym::VecDeque,
+ sym::LinkedList,
+ sym::BinaryHeap,
+ sym::HashSet,
+ sym::HashMap,
+ sym::PathBuf,
+ sym::Path,
+ sym::Receiver,
+ ];
+
+ let ty_to_check = match probably_ref_ty.kind() {
+ ty::Ref(_, ty_to_check, _) => *ty_to_check,
+ _ => probably_ref_ty,
+ };
+
+ let def_id = match ty_to_check.kind() {
+ ty::Array(..) => return Some(sym::array),
+ ty::Slice(..) => return Some(sym::slice),
+ ty::Adt(adt, _) => adt.did(),
+ _ => return None,
+ };
+
+ for &name in into_iter_collections {
+ if cx.tcx.is_diagnostic_item(name, def_id) {
+ return Some(cx.tcx.item_name(def_id));
+ }
+ }
+ None
+}
+
+/// Checks whether a type implements a trait.
+/// The function returns false in case the type contains an inference variable.
+///
+/// See:
+/// * [`get_trait_def_id`](super::get_trait_def_id) to get a trait [`DefId`].
+/// * [Common tools for writing lints] for an example how to use this function and other options.
+///
+/// [Common tools for writing lints]: https://github.com/rust-lang/rust-clippy/blob/master/doc/common_tools_writing_lints.md#checking-if-a-type-implements-a-specific-trait
+pub fn implements_trait<'tcx>(
+ cx: &LateContext<'tcx>,
+ ty: Ty<'tcx>,
+ trait_id: DefId,
+ ty_params: &[GenericArg<'tcx>],
++) -> bool {
++ implements_trait_with_env(cx.tcx, cx.param_env, ty, trait_id, ty_params)
++}
++
++/// Same as `implements_trait` but allows using a `ParamEnv` different from the lint context.
++pub fn implements_trait_with_env<'tcx>(
++ tcx: TyCtxt<'tcx>,
++ param_env: ParamEnv<'tcx>,
++ ty: Ty<'tcx>,
++ trait_id: DefId,
++ ty_params: &[GenericArg<'tcx>],
+) -> bool {
+ // Clippy shouldn't have infer types
+ assert!(!ty.needs_infer());
+
- let ty_params = cx.tcx.mk_substs(ty_params.iter());
- cx.tcx.infer_ctxt().enter(|infcx| {
++ let ty = tcx.erase_regions(ty);
+ if ty.has_escaping_bound_vars() {
+ return false;
+ }
- .type_implements_trait(trait_id, ty, ty_params, cx.param_env)
++ let ty_params = tcx.mk_substs(ty_params.iter());
++ tcx.infer_ctxt().enter(|infcx| {
+ infcx
++ .type_implements_trait(trait_id, ty, ty_params, param_env)
+ .must_apply_modulo_regions()
+ })
+}
+
+/// Checks whether this type implements `Drop`.
+pub fn has_drop<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
+ match ty.ty_adt_def() {
+ Some(def) => def.has_dtor(cx.tcx),
+ None => false,
+ }
+}
+
+// Returns whether the type has #[must_use] attribute
+pub fn is_must_use_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
+ match ty.kind() {
+ ty::Adt(adt, _) => cx.tcx.has_attr(adt.did(), sym::must_use),
+ ty::Foreign(did) => cx.tcx.has_attr(*did, sym::must_use),
+ ty::Slice(ty) | ty::Array(ty, _) | ty::RawPtr(ty::TypeAndMut { ty, .. }) | ty::Ref(_, ty, _) => {
+ // for the Array case we don't need to care for the len == 0 case
+ // because we don't want to lint functions returning empty arrays
+ is_must_use_ty(cx, *ty)
+ },
+ ty::Tuple(substs) => substs.iter().any(|ty| is_must_use_ty(cx, ty)),
+ ty::Opaque(def_id, _) => {
+ for (predicate, _) in cx.tcx.explicit_item_bounds(*def_id) {
+ if let ty::PredicateKind::Trait(trait_predicate) = predicate.kind().skip_binder() {
+ if cx.tcx.has_attr(trait_predicate.trait_ref.def_id, sym::must_use) {
+ return true;
+ }
+ }
+ }
+ false
+ },
+ ty::Dynamic(binder, _) => {
+ for predicate in binder.iter() {
+ if let ty::ExistentialPredicate::Trait(ref trait_ref) = predicate.skip_binder() {
+ if cx.tcx.has_attr(trait_ref.def_id, sym::must_use) {
+ return true;
+ }
+ }
+ }
+ false
+ },
+ _ => false,
+ }
+}
+
+// FIXME: Per https://doc.rust-lang.org/nightly/nightly-rustc/rustc_trait_selection/infer/at/struct.At.html#method.normalize
+// this function can be removed once the `normalize` method does not panic when normalization does
+// not succeed
+/// Checks if `Ty` is normalizable. This function is useful
+/// to avoid crashes on `layout_of`.
+pub fn is_normalizable<'tcx>(cx: &LateContext<'tcx>, param_env: ty::ParamEnv<'tcx>, ty: Ty<'tcx>) -> bool {
+ is_normalizable_helper(cx, param_env, ty, &mut FxHashMap::default())
+}
+
+fn is_normalizable_helper<'tcx>(
+ cx: &LateContext<'tcx>,
+ param_env: ty::ParamEnv<'tcx>,
+ ty: Ty<'tcx>,
+ cache: &mut FxHashMap<Ty<'tcx>, bool>,
+) -> bool {
+ if let Some(&cached_result) = cache.get(&ty) {
+ return cached_result;
+ }
+ // prevent recursive loops, false-negative is better than endless loop leading to stack overflow
+ cache.insert(ty, false);
+ let result = cx.tcx.infer_ctxt().enter(|infcx| {
+ let cause = rustc_middle::traits::ObligationCause::dummy();
+ if infcx.at(&cause, param_env).normalize(ty).is_ok() {
+ match ty.kind() {
+ ty::Adt(def, substs) => def.variants().iter().all(|variant| {
+ variant
+ .fields
+ .iter()
+ .all(|field| is_normalizable_helper(cx, param_env, field.ty(cx.tcx, substs), cache))
+ }),
+ _ => ty.walk().all(|generic_arg| match generic_arg.unpack() {
+ GenericArgKind::Type(inner_ty) if inner_ty != ty => {
+ is_normalizable_helper(cx, param_env, inner_ty, cache)
+ },
+ _ => true, // if inner_ty == ty, we've already checked it
+ }),
+ }
+ } else {
+ false
+ }
+ });
+ cache.insert(ty, result);
+ result
+}
+
+/// Returns `true` if the given type is a non aggregate primitive (a `bool` or `char`, any
+/// integer or floating-point number type). For checking aggregation of primitive types (e.g.
+/// tuples and slices of primitive type) see `is_recursively_primitive_type`
+pub fn is_non_aggregate_primitive_type(ty: Ty<'_>) -> bool {
+ matches!(ty.kind(), ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_))
+}
+
+/// Returns `true` if the given type is a primitive (a `bool` or `char`, any integer or
+/// floating-point number type, a `str`, or an array, slice, or tuple of those types).
+pub fn is_recursively_primitive_type(ty: Ty<'_>) -> bool {
+ match *ty.kind() {
+ ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Str => true,
+ ty::Ref(_, inner, _) if *inner.kind() == ty::Str => true,
+ ty::Array(inner_type, _) | ty::Slice(inner_type) => is_recursively_primitive_type(inner_type),
+ ty::Tuple(inner_types) => inner_types.iter().all(is_recursively_primitive_type),
+ _ => false,
+ }
+}
+
+/// Checks if the type is a reference equals to a diagnostic item
+pub fn is_type_ref_to_diagnostic_item(cx: &LateContext<'_>, ty: Ty<'_>, diag_item: Symbol) -> bool {
+ match ty.kind() {
+ ty::Ref(_, ref_ty, _) => match ref_ty.kind() {
+ ty::Adt(adt, _) => cx.tcx.is_diagnostic_item(diag_item, adt.did()),
+ _ => false,
+ },
+ _ => false,
+ }
+}
+
+/// Checks if the type is equal to a diagnostic item. To check if a type implements a
+/// trait marked with a diagnostic item use [`implements_trait`].
+///
+/// For a further exploitation what diagnostic items are see [diagnostic items] in
+/// rustc-dev-guide.
+///
+/// ---
+///
+/// If you change the signature, remember to update the internal lint `MatchTypeOnDiagItem`
+///
+/// [Diagnostic Items]: https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-items.html
+pub fn is_type_diagnostic_item(cx: &LateContext<'_>, ty: Ty<'_>, diag_item: Symbol) -> bool {
+ match ty.kind() {
+ ty::Adt(adt, _) => cx.tcx.is_diagnostic_item(diag_item, adt.did()),
+ _ => false,
+ }
+}
+
+/// Checks if the type is equal to a lang item.
+///
+/// Returns `false` if the `LangItem` is not defined.
+pub fn is_type_lang_item(cx: &LateContext<'_>, ty: Ty<'_>, lang_item: hir::LangItem) -> bool {
+ match ty.kind() {
+ ty::Adt(adt, _) => cx
+ .tcx
+ .lang_items()
+ .require(lang_item)
+ .map_or(false, |li| li == adt.did()),
+ _ => false,
+ }
+}
+
+/// Return `true` if the passed `typ` is `isize` or `usize`.
+pub fn is_isize_or_usize(typ: Ty<'_>) -> bool {
+ matches!(typ.kind(), ty::Int(IntTy::Isize) | ty::Uint(UintTy::Usize))
+}
+
+/// Checks if type is struct, enum or union type with the given def path.
+///
+/// If the type is a diagnostic item, use `is_type_diagnostic_item` instead.
+/// If you change the signature, remember to update the internal lint `MatchTypeOnDiagItem`
+pub fn match_type(cx: &LateContext<'_>, ty: Ty<'_>, path: &[&str]) -> bool {
+ match ty.kind() {
+ ty::Adt(adt, _) => match_def_path(cx, adt.did(), path),
+ _ => false,
+ }
+}
+
+/// Checks if the drop order for a type matters. Some std types implement drop solely to
+/// deallocate memory. For these types, and composites containing them, changing the drop order
+/// won't result in any observable side effects.
+pub fn needs_ordered_drop<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
+ fn needs_ordered_drop_inner<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, seen: &mut FxHashSet<Ty<'tcx>>) -> bool {
+ if !seen.insert(ty) {
+ return false;
+ }
+ if !ty.has_significant_drop(cx.tcx, cx.param_env) {
+ false
+ }
+ // Check for std types which implement drop, but only for memory allocation.
+ else if is_type_lang_item(cx, ty, LangItem::OwnedBox)
+ || matches!(
+ get_type_diagnostic_name(cx, ty),
+ Some(sym::HashSet | sym::Rc | sym::Arc | sym::cstring_type)
+ )
+ || match_type(cx, ty, &paths::WEAK_RC)
+ || match_type(cx, ty, &paths::WEAK_ARC)
+ {
+ // Check all of the generic arguments.
+ if let ty::Adt(_, subs) = ty.kind() {
+ subs.types().any(|ty| needs_ordered_drop_inner(cx, ty, seen))
+ } else {
+ true
+ }
+ } else if !cx
+ .tcx
+ .lang_items()
+ .drop_trait()
+ .map_or(false, |id| implements_trait(cx, ty, id, &[]))
+ {
+ // This type doesn't implement drop, so no side effects here.
+ // Check if any component type has any.
+ match ty.kind() {
+ ty::Tuple(fields) => fields.iter().any(|ty| needs_ordered_drop_inner(cx, ty, seen)),
+ ty::Array(ty, _) => needs_ordered_drop_inner(cx, *ty, seen),
+ ty::Adt(adt, subs) => adt
+ .all_fields()
+ .map(|f| f.ty(cx.tcx, subs))
+ .any(|ty| needs_ordered_drop_inner(cx, ty, seen)),
+ _ => true,
+ }
+ } else {
+ true
+ }
+ }
+
+ needs_ordered_drop_inner(cx, ty, &mut FxHashSet::default())
+}
+
+/// Peels off all references on the type. Returns the underlying type and the number of references
+/// removed.
+pub fn peel_mid_ty_refs(ty: Ty<'_>) -> (Ty<'_>, usize) {
+ fn peel(ty: Ty<'_>, count: usize) -> (Ty<'_>, usize) {
+ if let ty::Ref(_, ty, _) = ty.kind() {
+ peel(*ty, count + 1)
+ } else {
+ (ty, count)
+ }
+ }
+ peel(ty, 0)
+}
+
+/// Peels off all references on the type.Returns the underlying type, the number of references
+/// removed, and whether the pointer is ultimately mutable or not.
+pub fn peel_mid_ty_refs_is_mutable(ty: Ty<'_>) -> (Ty<'_>, usize, Mutability) {
+ fn f(ty: Ty<'_>, count: usize, mutability: Mutability) -> (Ty<'_>, usize, Mutability) {
+ match ty.kind() {
+ ty::Ref(_, ty, Mutability::Mut) => f(*ty, count + 1, mutability),
+ ty::Ref(_, ty, Mutability::Not) => f(*ty, count + 1, Mutability::Not),
+ _ => (ty, count, mutability),
+ }
+ }
+ f(ty, 0, Mutability::Mut)
+}
+
+/// Returns `true` if the given type is an `unsafe` function.
+pub fn type_is_unsafe_function<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
+ match ty.kind() {
+ ty::FnDef(..) | ty::FnPtr(_) => ty.fn_sig(cx.tcx).unsafety() == Unsafety::Unsafe,
+ _ => false,
+ }
+}
+
+/// Returns the base type for HIR references and pointers.
+pub fn walk_ptrs_hir_ty<'tcx>(ty: &'tcx hir::Ty<'tcx>) -> &'tcx hir::Ty<'tcx> {
+ match ty.kind {
+ TyKind::Ptr(ref mut_ty) | TyKind::Rptr(_, ref mut_ty) => walk_ptrs_hir_ty(mut_ty.ty),
+ _ => ty,
+ }
+}
+
+/// Returns the base type for references and raw pointers, and count reference
+/// depth.
+pub fn walk_ptrs_ty_depth(ty: Ty<'_>) -> (Ty<'_>, usize) {
+ fn inner(ty: Ty<'_>, depth: usize) -> (Ty<'_>, usize) {
+ match ty.kind() {
+ ty::Ref(_, ty, _) => inner(*ty, depth + 1),
+ _ => (ty, depth),
+ }
+ }
+ inner(ty, 0)
+}
+
+/// Returns `true` if types `a` and `b` are same types having same `Const` generic args,
+/// otherwise returns `false`
+pub fn same_type_and_consts<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
+ match (&a.kind(), &b.kind()) {
+ (&ty::Adt(did_a, substs_a), &ty::Adt(did_b, substs_b)) => {
+ if did_a != did_b {
+ return false;
+ }
+
+ substs_a
+ .iter()
+ .zip(substs_b.iter())
+ .all(|(arg_a, arg_b)| match (arg_a.unpack(), arg_b.unpack()) {
+ (GenericArgKind::Const(inner_a), GenericArgKind::Const(inner_b)) => inner_a == inner_b,
+ (GenericArgKind::Type(type_a), GenericArgKind::Type(type_b)) => {
+ same_type_and_consts(type_a, type_b)
+ },
+ _ => true,
+ })
+ },
+ _ => a == b,
+ }
+}
+
+/// Checks if a given type looks safe to be uninitialized.
+pub fn is_uninit_value_valid_for_ty(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
+ match *ty.kind() {
+ ty::Array(component, _) => is_uninit_value_valid_for_ty(cx, component),
+ ty::Tuple(types) => types.iter().all(|ty| is_uninit_value_valid_for_ty(cx, ty)),
+ ty::Adt(adt, _) => cx.tcx.lang_items().maybe_uninit() == Some(adt.did()),
+ _ => false,
+ }
+}
+
+/// Gets an iterator over all predicates which apply to the given item.
+pub fn all_predicates_of(tcx: TyCtxt<'_>, id: DefId) -> impl Iterator<Item = &(Predicate<'_>, Span)> {
+ let mut next_id = Some(id);
+ iter::from_fn(move || {
+ next_id.take().map(|id| {
+ let preds = tcx.predicates_of(id);
+ next_id = preds.parent;
+ preds.predicates.iter()
+ })
+ })
+ .flatten()
+}
+
+/// A signature for a function like type.
+#[derive(Clone, Copy)]
+pub enum ExprFnSig<'tcx> {
+ Sig(Binder<'tcx, FnSig<'tcx>>),
+ Closure(Binder<'tcx, FnSig<'tcx>>),
+ Trait(Binder<'tcx, Ty<'tcx>>, Option<Binder<'tcx, Ty<'tcx>>>),
+}
+impl<'tcx> ExprFnSig<'tcx> {
+ /// Gets the argument type at the given offset.
+ pub fn input(self, i: usize) -> Binder<'tcx, Ty<'tcx>> {
+ match self {
+ Self::Sig(sig) => sig.input(i),
+ Self::Closure(sig) => sig.input(0).map_bound(|ty| ty.tuple_fields()[i]),
+ Self::Trait(inputs, _) => inputs.map_bound(|ty| ty.tuple_fields()[i]),
+ }
+ }
+
+ /// Gets the result type, if one could be found. Note that the result type of a trait may not be
+ /// specified.
+ pub fn output(self) -> Option<Binder<'tcx, Ty<'tcx>>> {
+ match self {
+ Self::Sig(sig) | Self::Closure(sig) => Some(sig.output()),
+ Self::Trait(_, output) => output,
+ }
+ }
+}
+
+/// If the expression is function like, get the signature for it.
+pub fn expr_sig<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>) -> Option<ExprFnSig<'tcx>> {
+ if let Res::Def(DefKind::Fn | DefKind::Ctor(_, CtorKind::Fn) | DefKind::AssocFn, id) = path_res(cx, expr) {
+ Some(ExprFnSig::Sig(cx.tcx.fn_sig(id)))
+ } else {
+ let ty = cx.typeck_results().expr_ty_adjusted(expr).peel_refs();
+ match *ty.kind() {
+ ty::Closure(_, subs) => Some(ExprFnSig::Closure(subs.as_closure().sig())),
+ ty::FnDef(id, subs) => Some(ExprFnSig::Sig(cx.tcx.bound_fn_sig(id).subst(cx.tcx, subs))),
+ ty::FnPtr(sig) => Some(ExprFnSig::Sig(sig)),
+ ty::Dynamic(bounds, _) => {
+ let lang_items = cx.tcx.lang_items();
+ match bounds.principal() {
+ Some(bound)
+ if Some(bound.def_id()) == lang_items.fn_trait()
+ || Some(bound.def_id()) == lang_items.fn_once_trait()
+ || Some(bound.def_id()) == lang_items.fn_mut_trait() =>
+ {
+ let output = bounds
+ .projection_bounds()
+ .find(|p| lang_items.fn_once_output().map_or(false, |id| id == p.item_def_id()))
+ .map(|p| p.map_bound(|p| p.term.ty().expect("return type was a const")));
+ Some(ExprFnSig::Trait(bound.map_bound(|b| b.substs.type_at(0)), output))
+ },
+ _ => None,
+ }
+ },
+ ty::Param(_) | ty::Projection(..) => {
+ let mut inputs = None;
+ let mut output = None;
+ let lang_items = cx.tcx.lang_items();
+
+ for (pred, _) in all_predicates_of(cx.tcx, cx.typeck_results().hir_owner.to_def_id()) {
+ let mut is_input = false;
+ if let Some(ty) = pred
+ .kind()
+ .map_bound(|pred| match pred {
+ PredicateKind::Trait(p)
+ if (lang_items.fn_trait() == Some(p.def_id())
+ || lang_items.fn_mut_trait() == Some(p.def_id())
+ || lang_items.fn_once_trait() == Some(p.def_id()))
+ && p.self_ty() == ty =>
+ {
+ is_input = true;
+ Some(p.trait_ref.substs.type_at(1))
+ },
+ PredicateKind::Projection(p)
+ if Some(p.projection_ty.item_def_id) == lang_items.fn_once_output()
+ && p.projection_ty.self_ty() == ty =>
+ {
+ is_input = false;
+ p.term.ty()
+ },
+ _ => None,
+ })
+ .transpose()
+ {
+ if is_input && inputs.is_none() {
+ inputs = Some(ty);
+ } else if !is_input && output.is_none() {
+ output = Some(ty);
+ } else {
+ // Multiple different fn trait impls. Is this even allowed?
+ return None;
+ }
+ }
+ }
+
+ inputs.map(|ty| ExprFnSig::Trait(ty, output))
+ },
+ _ => None,
+ }
+ }
+}
+
+#[derive(Clone, Copy)]
+pub enum EnumValue {
+ Unsigned(u128),
+ Signed(i128),
+}
+impl core::ops::Add<u32> for EnumValue {
+ type Output = Self;
+ fn add(self, n: u32) -> Self::Output {
+ match self {
+ Self::Unsigned(x) => Self::Unsigned(x + u128::from(n)),
+ Self::Signed(x) => Self::Signed(x + i128::from(n)),
+ }
+ }
+}
+
+/// Attempts to read the given constant as though it were an an enum value.
+#[expect(clippy::cast_possible_truncation, clippy::cast_possible_wrap)]
+pub fn read_explicit_enum_value(tcx: TyCtxt<'_>, id: DefId) -> Option<EnumValue> {
+ if let Ok(ConstValue::Scalar(Scalar::Int(value))) = tcx.const_eval_poly(id) {
+ match tcx.type_of(id).kind() {
+ ty::Int(_) => Some(EnumValue::Signed(match value.size().bytes() {
+ 1 => i128::from(value.assert_bits(Size::from_bytes(1)) as u8 as i8),
+ 2 => i128::from(value.assert_bits(Size::from_bytes(2)) as u16 as i16),
+ 4 => i128::from(value.assert_bits(Size::from_bytes(4)) as u32 as i32),
+ 8 => i128::from(value.assert_bits(Size::from_bytes(8)) as u64 as i64),
+ 16 => value.assert_bits(Size::from_bytes(16)) as i128,
+ _ => return None,
+ })),
+ ty::Uint(_) => Some(EnumValue::Unsigned(match value.size().bytes() {
+ 1 => value.assert_bits(Size::from_bytes(1)),
+ 2 => value.assert_bits(Size::from_bytes(2)),
+ 4 => value.assert_bits(Size::from_bytes(4)),
+ 8 => value.assert_bits(Size::from_bytes(8)),
+ 16 => value.assert_bits(Size::from_bytes(16)),
+ _ => return None,
+ })),
+ _ => None,
+ }
+ } else {
+ None
+ }
+}
+
+/// Gets the value of the given variant.
+pub fn get_discriminant_value(tcx: TyCtxt<'_>, adt: AdtDef<'_>, i: VariantIdx) -> EnumValue {
+ let variant = &adt.variant(i);
+ match variant.discr {
+ VariantDiscr::Explicit(id) => read_explicit_enum_value(tcx, id).unwrap(),
+ VariantDiscr::Relative(x) => match adt.variant((i.as_usize() - x as usize).into()).discr {
+ VariantDiscr::Explicit(id) => read_explicit_enum_value(tcx, id).unwrap() + x,
+ VariantDiscr::Relative(_) => EnumValue::Unsigned(x.into()),
+ },
+ }
+}
+
+/// Check if the given type is either `core::ffi::c_void`, `std::os::raw::c_void`, or one of the
+/// platform specific `libc::<platform>::c_void` types in libc.
+pub fn is_c_void(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
+ if let ty::Adt(adt, _) = ty.kind()
+ && let &[krate, .., name] = &*cx.get_def_path(adt.did())
+ && let sym::libc | sym::core | sym::std = krate
+ && name.as_str() == "c_void"
+ {
+ true
+ } else {
+ false
+ }
+}
--- /dev/null
- /// // Bad
- /// Insert a short example of code that triggers the lint
- ///
- /// // Good
- /// Insert a short example of improved code that doesn't trigger the lint
+# Adding a new lint
+
+You are probably here because you want to add a new lint to Clippy. If this is
+the first time you're contributing to Clippy, this document guides you through
+creating an example lint from scratch.
+
+To get started, we will create a lint that detects functions called `foo`,
+because that's clearly a non-descriptive name.
+
+- [Adding a new lint](#adding-a-new-lint)
+ - [Setup](#setup)
+ - [Getting Started](#getting-started)
+ - [Testing](#testing)
+ - [Cargo lints](#cargo-lints)
+ - [Rustfix tests](#rustfix-tests)
+ - [Edition 2018 tests](#edition-2018-tests)
+ - [Testing manually](#testing-manually)
+ - [Lint declaration](#lint-declaration)
+ - [Lint registration](#lint-registration)
+ - [Lint passes](#lint-passes)
+ - [Emitting a lint](#emitting-a-lint)
+ - [Adding the lint logic](#adding-the-lint-logic)
+ - [Specifying the lint's minimum supported Rust version (MSRV)](#specifying-the-lints-minimum-supported-rust-version-msrv)
+ - [Author lint](#author-lint)
+ - [Print HIR lint](#print-hir-lint)
+ - [Documentation](#documentation)
+ - [Running rustfmt](#running-rustfmt)
+ - [Debugging](#debugging)
+ - [PR Checklist](#pr-checklist)
+ - [Adding configuration to a lint](#adding-configuration-to-a-lint)
+ - [Cheat Sheet](#cheat-sheet)
+
+## Setup
+
+See the [Basics](basics.md#get-the-code) documentation.
+
+## Getting Started
+
+There is a bit of boilerplate code that needs to be set up when creating a new
+lint. Fortunately, you can use the clippy dev tools to handle this for you. We
+are naming our new lint `foo_functions` (lints are generally written in snake
+case), and we don't need type information so it will have an early pass type
+(more on this later on). If you're not sure if the name you chose fits the lint,
+take a look at our [lint naming guidelines][lint_naming]. To get started on this
+lint you can run `cargo dev new_lint --name=foo_functions --pass=early
+--category=pedantic` (category will default to nursery if not provided). This
+command will create two files: `tests/ui/foo_functions.rs` and
+`clippy_lints/src/foo_functions.rs`, as well as
+[registering the lint](#lint-registration). For cargo lints, two project
+hierarchies (fail/pass) will be created by default under `tests/ui-cargo`.
+
+Next, we'll open up these files and add our lint!
+
+## Testing
+
+Let's write some tests first that we can execute while we iterate on our lint.
+
+Clippy uses UI tests for testing. UI tests check that the output of Clippy is
+exactly as expected. Each test is just a plain Rust file that contains the code
+we want to check. The output of Clippy is compared against a `.stderr` file.
+Note that you don't have to create this file yourself, we'll get to
+generating the `.stderr` files further down.
+
+We start by opening the test file created at `tests/ui/foo_functions.rs`.
+
+Update the file with some examples to get started:
+
+```rust
+#![warn(clippy::foo_functions)]
+
+// Impl methods
+struct A;
+impl A {
+ pub fn fo(&self) {}
+ pub fn foo(&self) {}
+ pub fn food(&self) {}
+}
+
+// Default trait methods
+trait B {
+ fn fo(&self) {}
+ fn foo(&self) {}
+ fn food(&self) {}
+}
+
+// Plain functions
+fn fo() {}
+fn foo() {}
+fn food() {}
+
+fn main() {
+ // We also don't want to lint method calls
+ foo();
+ let a = A;
+ a.foo();
+}
+```
+
+Now we can run the test with `TESTNAME=foo_functions cargo uitest`,
+currently this test is meaningless though.
+
+While we are working on implementing our lint, we can keep running the UI
+test. That allows us to check if the output is turning into what we want.
+
+Once we are satisfied with the output, we need to run
+`cargo dev bless` to update the `.stderr` file for our lint.
+Please note that, we should run `TESTNAME=foo_functions cargo uitest`
+every time before running `cargo dev bless`.
+Running `TESTNAME=foo_functions cargo uitest` should pass then. When we commit
+our lint, we need to commit the generated `.stderr` files, too. In general, you
+should only commit files changed by `cargo dev bless` for the
+specific lint you are creating/editing. Note that if the generated files are
+empty, they should be removed.
+
+Note that you can run multiple test files by specifying a comma separated list:
+`TESTNAME=foo_functions,test2,test3`.
+
+### Cargo lints
+
+For cargo lints, the process of testing differs in that we are interested in
+the `Cargo.toml` manifest file. We also need a minimal crate associated
+with that manifest.
+
+If our new lint is named e.g. `foo_categories`, after running `cargo dev new_lint`
+we will find by default two new crates, each with its manifest file:
+
+* `tests/ui-cargo/foo_categories/fail/Cargo.toml`: this file should cause the new lint to raise an error.
+* `tests/ui-cargo/foo_categories/pass/Cargo.toml`: this file should not trigger the lint.
+
+If you need more cases, you can copy one of those crates (under `foo_categories`) and rename it.
+
+The process of generating the `.stderr` file is the same, and prepending the `TESTNAME`
+variable to `cargo uitest` works too.
+
+## Rustfix tests
+
+If the lint you are working on is making use of structured suggestions, the
+test file should include a `// run-rustfix` comment at the top. This will
+additionally run [rustfix] for that test. Rustfix will apply the suggestions
+from the lint to the code of the test file and compare that to the contents of
+a `.fixed` file.
+
+Use `cargo dev bless` to automatically generate the
+`.fixed` file after running the tests.
+
+[rustfix]: https://github.com/rust-lang/rustfix
+
+## Edition 2018 tests
+
+Some features require the 2018 edition to work (e.g. `async_await`), but
+compile-test tests run on the 2015 edition by default. To change this behavior
+add `// edition:2018` at the top of the test file (note that it's space-sensitive).
+
+## Testing manually
+
+Manually testing against an example file can be useful if you have added some
+`println!`s and the test suite output becomes unreadable. To try Clippy with
+your local modifications, run
+
+```
+cargo dev lint input.rs
+```
+
+from the working copy root. With tests in place, let's have a look at
+implementing our lint now.
+
+## Lint declaration
+
+Let's start by opening the new file created in the `clippy_lints` crate
+at `clippy_lints/src/foo_functions.rs`. That's the crate where all the
+lint code is. This file has already imported some initial things we will need:
+
+```rust
+use rustc_lint::{EarlyLintPass, EarlyContext};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_ast::ast::*;
+```
+
+The next step is to update the lint declaration. Lints are declared using the
+[`declare_clippy_lint!`][declare_clippy_lint] macro, and we just need to update
+the auto-generated lint declaration to have a real description, something like this:
+
+```rust
+declare_clippy_lint! {
+ /// ### What it does
+ ///
+ /// ### Why is this bad?
+ ///
+ /// ### Example
+ /// ```rust
+ /// // example code
+ /// ```
+ #[clippy::version = "1.29.0"]
+ pub FOO_FUNCTIONS,
+ pedantic,
+ "function named `foo`, which is not a descriptive name"
+}
+```
+
+* The section of lines prefixed with `///` constitutes the lint documentation
+ section. This is the default documentation style and will be displayed
+ [like this][example_lint_page]. To render and open this documentation locally
+ in a browser, run `cargo dev serve`.
+* The `#[clippy::version]` attribute will be rendered as part of the lint documentation.
+ The value should be set to the current Rust version that the lint is developed in,
+ it can be retrieved by running `rustc -vV` in the rust-clippy directory. The version
+ is listed under *release*. (Use the version without the `-nightly`) suffix.
+* `FOO_FUNCTIONS` is the name of our lint. Be sure to follow the
+ [lint naming guidelines][lint_naming] here when naming your lint.
+ In short, the name should state the thing that is being checked for and
+ read well when used with `allow`/`warn`/`deny`.
+* `pedantic` sets the lint level to `Allow`.
+ The exact mapping can be found [here][category_level_mapping]
+* The last part should be a text that explains what exactly is wrong with the
+ code
+
+The rest of this file contains an empty implementation for our lint pass,
+which in this case is `EarlyLintPass` and should look like this:
+
+```rust
+// clippy_lints/src/foo_functions.rs
+
+// .. imports and lint declaration ..
+
+declare_lint_pass!(FooFunctions => [FOO_FUNCTIONS]);
+
+impl EarlyLintPass for FooFunctions {}
+```
+
+[declare_clippy_lint]: https://github.com/rust-lang/rust-clippy/blob/557f6848bd5b7183f55c1e1522a326e9e1df6030/clippy_lints/src/lib.rs#L60
+[example_lint_page]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure
+[lint_naming]: https://rust-lang.github.io/rfcs/0344-conventions-galore.html#lints
+[category_level_mapping]: https://github.com/rust-lang/rust-clippy/blob/557f6848bd5b7183f55c1e1522a326e9e1df6030/clippy_lints/src/lib.rs#L110
+
+## Lint registration
+
+When using `cargo dev new_lint`, the lint is automatically registered and
+nothing more has to be done.
+
+When declaring a new lint by hand and `cargo dev update_lints` is used, the lint
+pass may have to be registered manually in the `register_plugins` function in
+`clippy_lints/src/lib.rs`:
+
+```rust
+store.register_early_pass(|| Box::new(foo_functions::FooFunctions));
+```
+
+As one may expect, there is a corresponding `register_late_pass` method
+available as well. Without a call to one of `register_early_pass` or
+`register_late_pass`, the lint pass in question will not be run.
+
+One reason that `cargo dev update_lints` does not automate this step is that
+multiple lints can use the same lint pass, so registering the lint pass may
+already be done when adding a new lint. Another reason that this step is not
+automated is that the order that the passes are registered determines the order
+the passes actually run, which in turn affects the order that any emitted lints
+are output in.
+
+## Lint passes
+
+Writing a lint that only checks for the name of a function means that we only
+have to deal with the AST and don't have to deal with the type system at all.
+This is good, because it makes writing this particular lint less complicated.
+
+We have to make this decision with every new Clippy lint. It boils down to using
+either [`EarlyLintPass`][early_lint_pass] or [`LateLintPass`][late_lint_pass].
+
+In short, the `LateLintPass` has access to type information while the
+`EarlyLintPass` doesn't. If you don't need access to type information, use the
+`EarlyLintPass`. The `EarlyLintPass` is also faster. However linting speed
+hasn't really been a concern with Clippy so far.
+
+Since we don't need type information for checking the function name, we used
+`--pass=early` when running the new lint automation and all the imports were
+added accordingly.
+
+[early_lint_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/trait.EarlyLintPass.html
+[late_lint_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/trait.LateLintPass.html
+
+## Emitting a lint
+
+With UI tests and the lint declaration in place, we can start working on the
+implementation of the lint logic.
+
+Let's start by implementing the `EarlyLintPass` for our `FooFunctions`:
+
+```rust
+impl EarlyLintPass for FooFunctions {
+ fn check_fn(&mut self, cx: &EarlyContext<'_>, fn_kind: FnKind<'_>, span: Span, _: NodeId) {
+ // TODO: Emit lint here
+ }
+}
+```
+
+We implement the [`check_fn`][check_fn] method from the
+[`EarlyLintPass`][early_lint_pass] trait. This gives us access to various
+information about the function that is currently being checked. More on that in
+the next section. Let's worry about the details later and emit our lint for
+*every* function definition first.
+
+Depending on how complex we want our lint message to be, we can choose from a
+variety of lint emission functions. They can all be found in
+[`clippy_utils/src/diagnostics.rs`][diagnostics].
+
+`span_lint_and_help` seems most appropriate in this case. It allows us to
+provide an extra help message and we can't really suggest a better name
+automatically. This is how it looks:
+
+```rust
+impl EarlyLintPass for FooFunctions {
+ fn check_fn(&mut self, cx: &EarlyContext<'_>, fn_kind: FnKind<'_>, span: Span, _: NodeId) {
+ span_lint_and_help(
+ cx,
+ FOO_FUNCTIONS,
+ span,
+ "function named `foo`",
+ None,
+ "consider using a more meaningful name"
+ );
+ }
+}
+```
+
+Running our UI test should now produce output that contains the lint message.
+
+According to [the rustc-dev-guide], the text should be matter of fact and avoid
+capitalization and periods, unless multiple sentences are needed.
+When code or an identifier must appear in a message or label, it should be
+surrounded with single grave accents \`.
+
+[check_fn]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/trait.EarlyLintPass.html#method.check_fn
+[diagnostics]: https://github.com/rust-lang/rust-clippy/blob/master/clippy_utils/src/diagnostics.rs
+[the rustc-dev-guide]: https://rustc-dev-guide.rust-lang.org/diagnostics.html
+
+## Adding the lint logic
+
+Writing the logic for your lint will most likely be different from our example,
+so this section is kept rather short.
+
+Using the [`check_fn`][check_fn] method gives us access to [`FnKind`][fn_kind]
+that has the [`FnKind::Fn`] variant. It provides access to the name of the
+function/method via an [`Ident`][ident].
+
+With that we can expand our `check_fn` method to:
+
+```rust
+impl EarlyLintPass for FooFunctions {
+ fn check_fn(&mut self, cx: &EarlyContext<'_>, fn_kind: FnKind<'_>, span: Span, _: NodeId) {
+ if is_foo_fn(fn_kind) {
+ span_lint_and_help(
+ cx,
+ FOO_FUNCTIONS,
+ span,
+ "function named `foo`",
+ None,
+ "consider using a more meaningful name"
+ );
+ }
+ }
+}
+```
+
+We separate the lint conditional from the lint emissions because it makes the
+code a bit easier to read. In some cases this separation would also allow to
+write some unit tests (as opposed to only UI tests) for the separate function.
+
+In our example, `is_foo_fn` looks like:
+
+```rust
+// use statements, impl EarlyLintPass, check_fn, ..
+
+fn is_foo_fn(fn_kind: FnKind<'_>) -> bool {
+ match fn_kind {
+ FnKind::Fn(_, ident, ..) => {
+ // check if `fn` name is `foo`
+ ident.name.as_str() == "foo"
+ }
+ // ignore closures
+ FnKind::Closure(..) => false
+ }
+}
+```
+
+Now we should also run the full test suite with `cargo test`. At this point
+running `cargo test` should produce the expected output. Remember to run
+`cargo dev bless` to update the `.stderr` file.
+
+`cargo test` (as opposed to `cargo uitest`) will also ensure that our lint
+implementation is not violating any Clippy lints itself.
+
+That should be it for the lint implementation. Running `cargo test` should now
+pass.
+
+[fn_kind]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/visit/enum.FnKind.html
+[`FnKind::Fn`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/visit/enum.FnKind.html#variant.Fn
+[ident]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/symbol/struct.Ident.html
+
+## Specifying the lint's minimum supported Rust version (MSRV)
+
+Sometimes a lint makes suggestions that require a certain version of Rust. For example, the `manual_strip` lint suggests
+using `str::strip_prefix` and `str::strip_suffix` which is only available after Rust 1.45. In such cases, you need to
+ensure that the MSRV configured for the project is >= the MSRV of the required Rust feature. If multiple features are
+required, just use the one with a lower MSRV.
+
+First, add an MSRV alias for the required feature in [`clippy_utils::msrvs`](/clippy_utils/src/msrvs.rs). This can be
+accessed later as `msrvs::STR_STRIP_PREFIX`, for example.
+
+```rust
+msrv_aliases! {
+ ..
+ 1,45,0 { STR_STRIP_PREFIX }
+}
+```
+
+In order to access the project-configured MSRV, you need to have an `msrv` field in the LintPass struct, and a
+constructor to initialize the field. The `msrv` value is passed to the constructor in `clippy_lints/lib.rs`.
+
+```rust
+pub struct ManualStrip {
+ msrv: Option<RustcVersion>,
+}
+
+impl ManualStrip {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self { msrv }
+ }
+}
+```
+
+The project's MSRV can then be matched against the feature MSRV in the LintPass
+using the `meets_msrv` utility function.
+
+``` rust
+if !meets_msrv(self.msrv, msrvs::STR_STRIP_PREFIX) {
+ return;
+}
+```
+
+The project's MSRV can also be specified as an inner attribute, which overrides
+the value from `clippy.toml`. This can be accounted for using the
+`extract_msrv_attr!(LintContext)` macro and passing
+`LateContext`/`EarlyContext`.
+
+```rust
+impl<'tcx> LateLintPass<'tcx> for ManualStrip {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ ...
+ }
+ extract_msrv_attr!(LateContext);
+}
+```
+
+Once the `msrv` is added to the lint, a relevant test case should be added to
+`tests/ui/min_rust_version_attr.rs` which verifies that the lint isn't emitted
+if the project's MSRV is lower.
+
+As a last step, the lint should be added to the lint documentation. This is done
+in `clippy_lints/src/utils/conf.rs`:
+
+```rust
+define_Conf! {
+ /// Lint: LIST, OF, LINTS, <THE_NEWLY_ADDED_LINT>. The minimum rust version that the project supports
+ (msrv: Option<String> = None),
+ ...
+}
+```
+
+## Author lint
+
+If you have trouble implementing your lint, there is also the internal `author`
+lint to generate Clippy code that detects the offending pattern. It does not
+work for all of the Rust syntax, but can give a good starting point.
+
+The quickest way to use it, is the
+[Rust playground: play.rust-lang.org][author_example].
+Put the code you want to lint into the editor and add the `#[clippy::author]`
+attribute above the item. Then run Clippy via `Tools -> Clippy` and you should
+see the generated code in the output below.
+
+[Here][author_example] is an example on the playground.
+
+If the command was executed successfully, you can copy the code over to where
+you are implementing your lint.
+
+[author_example]: https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=9a12cb60e5c6ad4e3003ac6d5e63cf55
+
+## Print HIR lint
+
+To implement a lint, it's helpful to first understand the internal representation
+that rustc uses. Clippy has the `#[clippy::dump]` attribute that prints the
+[_High-Level Intermediate Representation (HIR)_] of the item, statement, or
+expression that the attribute is attached to. To attach the attribute to expressions
+you often need to enable `#![feature(stmt_expr_attributes)]`.
+
+[Here][print_hir_example] you can find an example, just select _Tools_ and run _Clippy_.
+
+[_High-Level Intermediate Representation (HIR)_]: https://rustc-dev-guide.rust-lang.org/hir.html
+[print_hir_example]: https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=daf14db3a7f39ca467cd1b86c34b9afb
+
+## Documentation
+
+The final thing before submitting our PR is to add some documentation to our
+lint declaration.
+
+Please document your lint with a doc comment akin to the following:
+
+```rust
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for ... (describe what the lint matches).
+ ///
+ /// ### Why is this bad?
+ /// Supply the reason for linting the code.
+ ///
+ /// ### Example
+ ///
+ /// ```rust,ignore
++ /// // A short example of code that triggers the lint
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust,ignore
++ /// // A short example of improved code that doesn't trigger the lint
+ /// ```
+ #[clippy::version = "1.29.0"]
+ pub FOO_FUNCTIONS,
+ pedantic,
+ "function named `foo`, which is not a descriptive name"
+}
+```
+
+Once your lint is merged, this documentation will show up in the [lint
+list][lint_list].
+
+[lint_list]: https://rust-lang.github.io/rust-clippy/master/index.html
+
+## Running rustfmt
+
+[Rustfmt] is a tool for formatting Rust code according to style guidelines.
+Your code has to be formatted by `rustfmt` before a PR can be merged.
+Clippy uses nightly `rustfmt` in the CI.
+
+It can be installed via `rustup`:
+
+```bash
+rustup component add rustfmt --toolchain=nightly
+```
+
+Use `cargo dev fmt` to format the whole codebase. Make sure that `rustfmt` is
+installed for the nightly toolchain.
+
+[Rustfmt]: https://github.com/rust-lang/rustfmt
+
+## Debugging
+
+If you want to debug parts of your lint implementation, you can use the [`dbg!`]
+macro anywhere in your code. Running the tests should then include the debug
+output in the `stdout` part.
+
+[`dbg!`]: https://doc.rust-lang.org/std/macro.dbg.html
+
+## PR Checklist
+
+Before submitting your PR make sure you followed all of the basic requirements:
+
+<!-- Sync this with `.github/PULL_REQUEST_TEMPLATE` -->
+
+- \[ ] Followed [lint naming conventions][lint_naming]
+- \[ ] Added passing UI tests (including committed `.stderr` file)
+- \[ ] `cargo test` passes locally
+- \[ ] Executed `cargo dev update_lints`
+- \[ ] Added lint documentation
+- \[ ] Run `cargo dev fmt`
+
+## Adding configuration to a lint
+
+Clippy supports the configuration of lints values using a `clippy.toml` file in the workspace
+directory. Adding a configuration to a lint can be useful for thresholds or to constrain some
+behavior that can be seen as a false positive for some users. Adding a configuration is done
+in the following steps:
+
+1. Adding a new configuration entry to [clippy_lints::utils::conf](/clippy_lints/src/utils/conf.rs)
+ like this:
+ ```rust
+ /// Lint: LINT_NAME.
+ ///
+ /// <The configuration field doc comment>
+ (configuration_ident: Type = DefaultValue),
+ ```
+ The doc comment is automatically added to the documentation of the listed lints. The default
+ value will be formatted using the `Debug` implementation of the type.
+2. Adding the configuration value to the lint impl struct:
+ 1. This first requires the definition of a lint impl struct. Lint impl structs are usually
+ generated with the `declare_lint_pass!` macro. This struct needs to be defined manually
+ to add some kind of metadata to it:
+ ```rust
+ // Generated struct definition
+ declare_lint_pass!(StructName => [
+ LINT_NAME
+ ]);
+
+ // New manual definition struct
+ #[derive(Copy, Clone)]
+ pub struct StructName {}
+
+ impl_lint_pass!(StructName => [
+ LINT_NAME
+ ]);
+ ```
+
+ 2. Next add the configuration value and a corresponding creation method like this:
+ ```rust
+ #[derive(Copy, Clone)]
+ pub struct StructName {
+ configuration_ident: Type,
+ }
+
+ // ...
+
+ impl StructName {
+ pub fn new(configuration_ident: Type) -> Self {
+ Self {
+ configuration_ident,
+ }
+ }
+ }
+ ```
+3. Passing the configuration value to the lint impl struct:
+
+ First find the struct construction in the [clippy_lints lib file](/clippy_lints/src/lib.rs).
+ The configuration value is now cloned or copied into a local value that is then passed to the
+ impl struct like this:
+ ```rust
+ // Default generated registration:
+ store.register_*_pass(|| box module::StructName);
+
+ // New registration with configuration value
+ let configuration_ident = conf.configuration_ident.clone();
+ store.register_*_pass(move || box module::StructName::new(configuration_ident));
+ ```
+
+ Congratulations the work is almost done. The configuration value can now be accessed
+ in the linting code via `self.configuration_ident`.
+
+4. Adding tests:
+ 1. The default configured value can be tested like any normal lint in [`tests/ui`](/tests/ui).
+ 2. The configuration itself will be tested separately in [`tests/ui-toml`](/tests/ui-toml).
+ Simply add a new subfolder with a fitting name. This folder contains a `clippy.toml` file
+ with the configuration value and a rust file that should be linted by Clippy. The test can
+ otherwise be written as usual.
+
+## Cheat Sheet
+
+Here are some pointers to things you are likely going to need for every lint:
+
+* [Clippy utils][utils] - Various helper functions. Maybe the function you need
+ is already in here ([`is_type_diagnostic_item`], [`implements_trait`], [`snippet`], etc)
+* [Clippy diagnostics][diagnostics]
+* [Let chains][let-chains]
+* [`from_expansion`][from_expansion] and [`in_external_macro`][in_external_macro]
+* [`Span`][span]
+* [`Applicability`][applicability]
+* [Common tools for writing lints](common_tools_writing_lints.md) helps with common operations
+* [The rustc-dev-guide][rustc-dev-guide] explains a lot of internal compiler concepts
+* [The nightly rustc docs][nightly_docs] which has been linked to throughout
+ this guide
+
+For `EarlyLintPass` lints:
+
+* [`EarlyLintPass`][early_lint_pass]
+* [`rustc_ast::ast`][ast]
+
+For `LateLintPass` lints:
+
+* [`LateLintPass`][late_lint_pass]
+* [`Ty::TyKind`][ty]
+
+While most of Clippy's lint utils are documented, most of rustc's internals lack
+documentation currently. This is unfortunate, but in most cases you can probably
+get away with copying things from existing similar lints. If you are stuck,
+don't hesitate to ask on [Zulip] or in the issue/PR.
+
+[utils]: https://doc.rust-lang.org/nightly/nightly-rustc/clippy_utils/index.html
+[`is_type_diagnostic_item`]: https://doc.rust-lang.org/nightly/nightly-rustc/clippy_utils/ty/fn.is_type_diagnostic_item.html
+[`implements_trait`]: https://doc.rust-lang.org/nightly/nightly-rustc/clippy_utils/ty/fn.implements_trait.html
+[`snippet`]: https://doc.rust-lang.org/nightly/nightly-rustc/clippy_utils/source/fn.snippet.html
+[let-chains]: https://github.com/rust-lang/rust/pull/94927
+[from_expansion]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/struct.Span.html#method.from_expansion
+[in_external_macro]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/lint/fn.in_external_macro.html
+[span]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/struct.Span.html
+[applicability]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_errors/enum.Applicability.html
+[rustc-dev-guide]: https://rustc-dev-guide.rust-lang.org/
+[nightly_docs]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/
+[ast]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/ast/index.html
+[ty]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/sty/index.html
+[Zulip]: https://rust-lang.zulipchat.com/#narrow/stream/clippy
--- /dev/null
- use clippy_utils::{is_type_diagnostic_item, return_ty};
+# Common tools for writing lints
+
+You may need following tooltips to catch up with common operations.
+
+- [Common tools for writing lints](#common-tools-for-writing-lints)
+ - [Retrieving the type of an expression](#retrieving-the-type-of-an-expression)
+ - [Checking if an expr is calling a specific method](#checking-if-an-expr-is-calling-a-specific-method)
+ - [Checking for a specific type](#checking-for-a-specific-type)
+ - [Checking if a type implements a specific trait](#checking-if-a-type-implements-a-specific-trait)
+ - [Checking if a type defines a specific method](#checking-if-a-type-defines-a-specific-method)
+ - [Dealing with macros](#dealing-with-macros-and-expansions)
+
+Useful Rustc dev guide links:
+- [Stages of compilation](https://rustc-dev-guide.rust-lang.org/compiler-src.html#the-main-stages-of-compilation)
+- [Diagnostic items](https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-items.html)
+- [Type checking](https://rustc-dev-guide.rust-lang.org/type-checking.html)
+- [Ty module](https://rustc-dev-guide.rust-lang.org/ty.html)
+
+## Retrieving the type of an expression
+
+Sometimes you may want to retrieve the type `Ty` of an expression `Expr`, for example to answer following questions:
+
+- which type does this expression correspond to (using its [`TyKind`][TyKind])?
+- is it a sized type?
+- is it a primitive type?
+- does it implement a trait?
+
+This operation is performed using the [`expr_ty()`][expr_ty] method from the [`TypeckResults`][TypeckResults] struct,
+that gives you access to the underlying structure [`Ty`][Ty].
+
+Example of use:
+```rust
+impl LateLintPass<'_> for MyStructLint {
+ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
+ // Get type of `expr`
+ let ty = cx.typeck_results().expr_ty(expr);
+ // Match its kind to enter its type
+ match ty.kind {
+ ty::Adt(adt_def, _) if adt_def.is_struct() => println!("Our `expr` is a struct!"),
+ _ => ()
+ }
+ }
+}
+```
+
+Similarly in [`TypeckResults`][TypeckResults] methods, you have the [`pat_ty()`][pat_ty] method
+to retrieve a type from a pattern.
+
+Two noticeable items here:
+- `cx` is the lint context [`LateContext`][LateContext]. The two most useful
+ data structures in this context are `tcx` and the `TypeckResults` returned by
+ `LateContext::typeck_results`, allowing us to jump to type definitions and
+ other compilation stages such as HIR.
+- `typeck_results`'s return value is [`TypeckResults`][TypeckResults] and is
+ created by type checking step, it includes useful information such as types
+ of expressions, ways to resolve methods and so on.
+
+## Checking if an expr is calling a specific method
+
+Starting with an `expr`, you can check whether it is calling a specific method `some_method`:
+
+```rust
+impl<'tcx> LateLintPass<'tcx> for MyStructLint {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
+ // Check our expr is calling a method
+ if let hir::ExprKind::MethodCall(path, _, [_self_arg, ..]) = &expr.kind
+ // Check the name of this method is `some_method`
+ && path.ident.name == sym!(some_method)
+ // Optionally, check the type of the self argument.
+ // - See "Checking for a specific type"
+ {
+ // ...
+ }
+ }
+}
+```
+
+## Checking for a specific type
+
+There are three ways to check if an expression type is a specific type we want to check for.
+All of these methods only check for the base type, generic arguments have to be checked separately.
+
+```rust
+use clippy_utils::ty::{is_type_diagnostic_item, is_type_lang_item};
+use clippy_utils::{paths, match_def_path};
+use rustc_span::symbol::sym;
+use rustc_hir::LangItem;
+
+impl LateLintPass<'_> for MyStructLint {
+ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
+ // Getting the expression type
+ let ty = cx.typeck_results().expr_ty(expr);
+
+ // 1. Using diagnostic items
+ // The last argument is the diagnostic item to check for
+ if is_type_diagnostic_item(cx, ty, sym::Option) {
+ // The type is an `Option`
+ }
+
+ // 2. Using lang items
+ if is_type_lang_item(cx, ty, LangItem::RangeFull) {
+ // The type is a full range like `.drain(..)`
+ }
+
+ // 3. Using the type path
+ // This method should be avoided if possible
+ if match_def_path(cx, def_id, &paths::RESULT) {
+ // The type is a `core::result::Result`
+ }
+ }
+}
+```
+
+Prefer using diagnostic items and lang items where possible.
+
+## Checking if a type implements a specific trait
+
+There are three ways to do this, depending on if the target trait has a diagnostic item, lang item or neither.
+
+```rust
+use clippy_utils::{implements_trait, is_trait_method, match_trait_method, paths};
+use rustc_span::symbol::sym;
+
+impl LateLintPass<'_> for MyStructLint {
+ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
+ // 1. Using diagnostic items with the expression
+ // we use `is_trait_method` function from Clippy's utils
+ if is_trait_method(cx, expr, sym::Iterator) {
+ // method call in `expr` belongs to `Iterator` trait
+ }
+
+ // 2. Using lang items with the expression type
+ let ty = cx.typeck_results().expr_ty(expr);
+ if cx.tcx.lang_items()
+ // we are looking for the `DefId` of `Drop` trait in lang items
+ .drop_trait()
+ // then we use it with our type `ty` by calling `implements_trait` from Clippy's utils
+ .map_or(false, |id| implements_trait(cx, ty, id, &[])) {
+ // `expr` implements `Drop` trait
+ }
+
+ // 3. Using the type path with the expression
+ // we use `match_trait_method` function from Clippy's utils
+ // (This method should be avoided if possible)
+ if match_trait_method(cx, expr, &paths::INTO) {
+ // `expr` implements `Into` trait
+ }
+ }
+}
+```
+
+> Prefer using diagnostic and lang items, if the target trait has one.
+
+We access lang items through the type context `tcx`. `tcx` is of type [`TyCtxt`][TyCtxt] and is defined in the `rustc_middle` crate.
+A list of defined paths for Clippy can be found in [paths.rs][paths]
+
+## Checking if a type defines a specific method
+
+To check if our type defines a method called `some_method`:
+
+```rust
++use clippy_utils::ty::is_type_diagnostic_item;
++use clippy_utils::return_ty;
+
+impl<'tcx> LateLintPass<'tcx> for MyTypeImpl {
+ fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx ImplItem<'_>) {
+ // Check if item is a method/function
+ if let ImplItemKind::Fn(ref signature, _) = impl_item.kind
+ // Check the method is named `some_method`
+ && impl_item.ident.name == sym!(some_method)
+ // We can also check it has a parameter `self`
+ && signature.decl.implicit_self.has_implicit_self()
+ // We can go further and even check if its return type is `String`
+ && is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id), sym!(string_type))
+ {
+ // ...
+ }
+ }
+}
+```
+
+## Dealing with macros and expansions
+
+Keep in mind that macros are already expanded and desugaring is already applied
+to the code representation that you are working with in Clippy. This unfortunately causes a lot of
+false positives because macro expansions are "invisible" unless you actively check for them.
+Generally speaking, code with macro expansions should just be ignored by Clippy because that code can be
+dynamic in ways that are difficult or impossible to see.
+Use the following functions to deal with macros:
+
+- `span.from_expansion()`: detects if a span is from macro expansion or desugaring.
+ Checking this is a common first step in a lint.
+
+ ```rust
+ if expr.span.from_expansion() {
+ // just forget it
+ return;
+ }
+ ```
+
+- `span.ctxt()`: the span's context represents whether it is from expansion, and if so, which macro call expanded it.
+ It is sometimes useful to check if the context of two spans are equal.
+
+ ```rust
+ // expands to `1 + 0`, but don't lint
+ 1 + mac!()
+ ```
+ ```rust
+ if left.span.ctxt() != right.span.ctxt() {
+ // the coder most likely cannot modify this expression
+ return;
+ }
+ ```
+ Note: Code that is not from expansion is in the "root" context. So any spans where `from_expansion` returns `true` can
+ be assumed to have the same context. And so just using `span.from_expansion()` is often good enough.
+
+
+- `in_external_macro(span)`: detect if the given span is from a macro defined in a foreign crate.
+ If you want the lint to work with macro-generated code, this is the next line of defense to avoid macros
+ not defined in the current crate. It doesn't make sense to lint code that the coder can't change.
+
+ You may want to use it for example to not start linting in macros from other crates
+
+ ```rust
+ #[macro_use]
+ extern crate a_crate_with_macros;
+
+ // `foo` is defined in `a_crate_with_macros`
+ foo!("bar");
+
+ // if we lint the `match` of `foo` call and test its span
+ assert_eq!(in_external_macro(cx.sess(), match_span), true);
+ ```
+
+- `span.ctxt()`: the span's context represents whether it is from expansion, and if so, what expanded it
+
+One thing `SpanContext` is useful for is to check if two spans are in the same context. For example,
+in `a == b`, `a` and `b` have the same context. In a `macro_rules!` with `a == $b`, `$b` is expanded to some
+expression with a different context from `a`.
+
+ ```rust
+ macro_rules! m {
+ ($a:expr, $b:expr) => {
+ if $a.is_some() {
+ $b;
+ }
+ }
+ }
+
+ let x: Option<u32> = Some(42);
+ m!(x, x.unwrap());
+
+ // These spans are not from the same context
+ // x.is_some() is from inside the macro
+ // x.unwrap() is from outside the macro
+ assert_eq!(x_is_some_span.ctxt(), x_unwrap_span.ctxt());
+ ```
+
+[Ty]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.Ty.html
+[TyKind]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/enum.TyKind.html
+[TypeckResults]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TypeckResults.html
+[expr_ty]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TypeckResults.html#method.expr_ty
+[LateContext]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/struct.LateContext.html
+[TyCtxt]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/context/struct.TyCtxt.html
+[pat_ty]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/context/struct.TypeckResults.html#method.pat_ty
+[paths]: ../clippy_utils/src/paths.rs
--- /dev/null
- clap = "2.33"
+[package]
+name = "lintcheck"
+version = "0.0.1"
+description = "tool to monitor impact of changes in Clippys lints on a part of the ecosystem"
+readme = "README.md"
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/rust-lang/rust-clippy"
+categories = ["development-tools"]
+edition = "2021"
+publish = false
+
+[dependencies]
+cargo_metadata = "0.14"
++clap = "3.1"
+flate2 = "1.0"
+rayon = "1.5.1"
+serde = { version = "1.0", features = ["derive"] }
+tar = "0.4"
+toml = "0.5"
+ureq = "2.2"
+walkdir = "2.3"
+
+[features]
+deny-warnings = []
--- /dev/null
- use clap::{App, Arg, ArgMatches};
++use clap::{Arg, ArgMatches, Command};
+use std::env;
+use std::path::PathBuf;
+
- fn get_clap_config<'a>() -> ArgMatches<'a> {
- App::new("lintcheck")
++fn get_clap_config() -> ArgMatches {
++ Command::new("lintcheck")
+ .about("run clippy on a set of crates and check output")
+ .arg(
- Arg::with_name("only")
++ Arg::new("only")
+ .takes_value(true)
+ .value_name("CRATE")
+ .long("only")
+ .help("Only process a single crate of the list"),
+ )
+ .arg(
- Arg::with_name("crates-toml")
++ Arg::new("crates-toml")
+ .takes_value(true)
+ .value_name("CRATES-SOURCES-TOML-PATH")
+ .long("crates-toml")
+ .help("Set the path for a crates.toml where lintcheck should read the sources from"),
+ )
+ .arg(
- Arg::with_name("threads")
++ Arg::new("threads")
+ .takes_value(true)
+ .value_name("N")
- .short("j")
++ .short('j')
+ .long("jobs")
+ .help("Number of threads to use, 0 automatic choice"),
+ )
+ .arg(
- Arg::with_name("fix")
++ Arg::new("fix")
+ .long("--fix")
+ .help("Runs cargo clippy --fix and checks if all suggestions apply"),
+ )
+ .arg(
- Arg::with_name("filter")
++ Arg::new("filter")
+ .long("--filter")
+ .takes_value(true)
- .multiple(true)
++ .multiple_occurrences(true)
+ .value_name("clippy_lint_name")
+ .help("Apply a filter to only collect specified lints, this also overrides `allow` attributes"),
+ )
+ .arg(
- Arg::with_name("markdown")
++ Arg::new("markdown")
+ .long("--markdown")
+ .help("Change the reports table to use markdown links"),
+ )
+ .get_matches()
+}
+
+#[derive(Debug)]
+pub(crate) struct LintcheckConfig {
+ /// max number of jobs to spawn (default 1)
+ pub max_jobs: usize,
+ /// we read the sources to check from here
+ pub sources_toml_path: PathBuf,
+ /// we save the clippy lint results here
+ pub lintcheck_results_path: PathBuf,
+ /// Check only a specified package
+ pub only: Option<String>,
+ /// whether to just run --fix and not collect all the warnings
+ pub fix: bool,
+ /// A list of lints that this lintcheck run should focus on
+ pub lint_filter: Vec<String>,
+ /// Indicate if the output should support markdown syntax
+ pub markdown: bool,
+}
+
+impl LintcheckConfig {
+ pub fn new() -> Self {
+ let clap_config = get_clap_config();
+
+ // first, check if we got anything passed via the LINTCHECK_TOML env var,
+ // if not, ask clap if we got any value for --crates-toml <foo>
+ // if not, use the default "lintcheck/lintcheck_crates.toml"
+ let sources_toml = env::var("LINTCHECK_TOML").unwrap_or_else(|_| {
+ clap_config
+ .value_of("crates-toml")
+ .clone()
+ .unwrap_or("lintcheck/lintcheck_crates.toml")
+ .to_string()
+ });
+
+ let markdown = clap_config.is_present("markdown");
+ let sources_toml_path = PathBuf::from(sources_toml);
+
+ // for the path where we save the lint results, get the filename without extension (so for
+ // wasd.toml, use "wasd"...)
+ let filename: PathBuf = sources_toml_path.file_stem().unwrap().into();
+ let lintcheck_results_path = PathBuf::from(format!(
+ "lintcheck-logs/{}_logs.{}",
+ filename.display(),
+ if markdown { "md" } else { "txt" }
+ ));
+
+ // look at the --threads arg, if 0 is passed, ask rayon rayon how many threads it would spawn and
+ // use half of that for the physical core count
+ // by default use a single thread
+ let max_jobs = match clap_config.value_of("threads") {
+ Some(threads) => {
+ let threads: usize = threads
+ .parse()
+ .unwrap_or_else(|_| panic!("Failed to parse '{}' to a digit", threads));
+ if threads == 0 {
+ // automatic choice
+ // Rayon seems to return thread count so half that for core count
+ (rayon::current_num_threads() / 2) as usize
+ } else {
+ threads
+ }
+ },
+ // no -j passed, use a single thread
+ None => 1,
+ };
+
+ let lint_filter: Vec<String> = clap_config
+ .values_of("filter")
+ .map(|iter| {
+ iter.map(|lint_name| {
+ let mut filter = lint_name.replace('_', "-");
+ if !filter.starts_with("clippy::") {
+ filter.insert_str(0, "clippy::");
+ }
+ filter
+ })
+ .collect()
+ })
+ .unwrap_or_default();
+
+ LintcheckConfig {
+ max_jobs,
+ sources_toml_path,
+ lintcheck_results_path,
+ only: clap_config.value_of("only").map(String::from),
+ fix: clap_config.is_present("fix"),
+ lint_filter,
+ markdown,
+ }
+ }
+}
--- /dev/null
- channel = "nightly-2022-05-19"
+[toolchain]
++channel = "nightly-2022-06-04"
+components = ["cargo", "llvm-tools-preview", "rust-src", "rust-std", "rustc", "rustc-dev", "rustfmt"]
--- /dev/null
- help: Try adding to dev-dependencies in Cargo.toml",
- not_found
+#![feature(test)] // compiletest_rs requires this attribute
+#![feature(once_cell)]
++#![feature(is_sorted)]
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+#![warn(rust_2018_idioms, unused_lifetimes)]
+
+use compiletest_rs as compiletest;
+use compiletest_rs::common::Mode as TestMode;
+
+use std::collections::HashMap;
+use std::env::{self, remove_var, set_var, var_os};
+use std::ffi::{OsStr, OsString};
+use std::fs;
+use std::io;
+use std::lazy::SyncLazy;
+use std::path::{Path, PathBuf};
+use test_utils::IS_RUSTC_TEST_SUITE;
+
+mod test_utils;
+
+// whether to run internal tests or not
+const RUN_INTERNAL_TESTS: bool = cfg!(feature = "internal");
+
+/// All crates used in UI tests are listed here
+static TEST_DEPENDENCIES: &[&str] = &[
++ "clap",
+ "clippy_utils",
+ "derive_new",
+ "futures",
+ "if_chain",
+ "itertools",
+ "quote",
+ "regex",
+ "serde",
+ "serde_derive",
+ "syn",
+ "tokio",
+ "parking_lot",
+ "rustc_semver",
+];
+
+// Test dependencies may need an `extern crate` here to ensure that they show up
+// in the depinfo file (otherwise cargo thinks they are unused)
+#[allow(unused_extern_crates)]
++extern crate clap;
++#[allow(unused_extern_crates)]
+extern crate clippy_utils;
+#[allow(unused_extern_crates)]
+extern crate derive_new;
+#[allow(unused_extern_crates)]
+extern crate futures;
+#[allow(unused_extern_crates)]
+extern crate if_chain;
+#[allow(unused_extern_crates)]
+extern crate itertools;
+#[allow(unused_extern_crates)]
+extern crate parking_lot;
+#[allow(unused_extern_crates)]
+extern crate quote;
+#[allow(unused_extern_crates)]
+extern crate rustc_semver;
+#[allow(unused_extern_crates)]
+extern crate syn;
+#[allow(unused_extern_crates)]
+extern crate tokio;
+
+/// Produces a string with an `--extern` flag for all UI test crate
+/// dependencies.
+///
+/// The dependency files are located by parsing the depinfo file for this test
+/// module. This assumes the `-Z binary-dep-depinfo` flag is enabled. All test
+/// dependencies must be added to Cargo.toml at the project root. Test
+/// dependencies that are not *directly* used by this test module require an
+/// `extern crate` declaration.
+static EXTERN_FLAGS: SyncLazy<String> = SyncLazy::new(|| {
+ let current_exe_depinfo = {
+ let mut path = env::current_exe().unwrap();
+ path.set_extension("d");
+ fs::read_to_string(path).unwrap()
+ };
+ let mut crates: HashMap<&str, &str> = HashMap::with_capacity(TEST_DEPENDENCIES.len());
+ for line in current_exe_depinfo.lines() {
+ // each dependency is expected to have a Makefile rule like `/path/to/crate-hash.rlib:`
+ let parse_name_path = || {
+ if line.starts_with(char::is_whitespace) {
+ return None;
+ }
+ let path_str = line.strip_suffix(':')?;
+ let path = Path::new(path_str);
+ if !matches!(path.extension()?.to_str()?, "rlib" | "so" | "dylib" | "dll") {
+ return None;
+ }
+ let (name, _hash) = path.file_stem()?.to_str()?.rsplit_once('-')?;
+ // the "lib" prefix is not present for dll files
+ let name = name.strip_prefix("lib").unwrap_or(name);
+ Some((name, path_str))
+ };
+ if let Some((name, path)) = parse_name_path() {
+ if TEST_DEPENDENCIES.contains(&name) {
+ // A dependency may be listed twice if it is available in sysroot,
+ // and the sysroot dependencies are listed first. As of the writing,
+ // this only seems to apply to if_chain.
+ crates.insert(name, path);
+ }
+ }
+ }
+ let not_found: Vec<&str> = TEST_DEPENDENCIES
+ .iter()
+ .copied()
+ .filter(|n| !crates.contains_key(n))
+ .collect();
+ assert!(
+ not_found.is_empty(),
+ "dependencies not found in depinfo: {:?}\n\
+ help: Make sure the `-Z binary-dep-depinfo` rust flag is enabled\n\
- let config = base_config("ui");
++ help: Try adding to dev-dependencies in Cargo.toml\n\
++ help: Be sure to also add `extern crate ...;` to tests/compile-test.rs",
++ not_found,
+ );
+ crates
+ .into_iter()
+ .map(|(name, path)| format!(" --extern {}={}", name, path))
+ .collect()
+});
+
+fn base_config(test_dir: &str) -> compiletest::Config {
+ let mut config = compiletest::Config {
+ edition: Some("2021".into()),
+ mode: TestMode::Ui,
+ ..compiletest::Config::default()
+ };
+
+ if let Ok(filters) = env::var("TESTNAME") {
+ config.filters = filters.split(',').map(ToString::to_string).collect();
+ }
+
+ if let Some(path) = option_env!("RUSTC_LIB_PATH") {
+ let path = PathBuf::from(path);
+ config.run_lib_path = path.clone();
+ config.compile_lib_path = path;
+ }
+ let current_exe_path = env::current_exe().unwrap();
+ let deps_path = current_exe_path.parent().unwrap();
+ let profile_path = deps_path.parent().unwrap();
+
+ // Using `-L dependency={}` enforces that external dependencies are added with `--extern`.
+ // This is valuable because a) it allows us to monitor what external dependencies are used
+ // and b) it ensures that conflicting rlibs are resolved properly.
+ let host_libs = option_env!("HOST_LIBS")
+ .map(|p| format!(" -L dependency={}", Path::new(p).join("deps").display()))
+ .unwrap_or_default();
+ config.target_rustcflags = Some(format!(
+ "--emit=metadata -Dwarnings -Zui-testing -L dependency={}{}{}",
+ deps_path.display(),
+ host_libs,
+ &*EXTERN_FLAGS,
+ ));
+
+ config.src_base = Path::new("tests").join(test_dir);
+ config.build_base = profile_path.join("test").join(test_dir);
+ config.rustc_path = profile_path.join(if cfg!(windows) {
+ "clippy-driver.exe"
+ } else {
+ "clippy-driver"
+ });
+ config
+}
+
+fn run_ui() {
++ let mut config = base_config("ui");
++ config.rustfix_coverage = true;
+ // use tests/clippy.toml
+ let _g = VarGuard::set("CARGO_MANIFEST_DIR", fs::canonicalize("tests").unwrap());
+ let _threads = VarGuard::set(
+ "RUST_TEST_THREADS",
+ // if RUST_TEST_THREADS is set, adhere to it, otherwise override it
+ env::var("RUST_TEST_THREADS").unwrap_or_else(|_| {
+ std::thread::available_parallelism()
+ .map_or(1, std::num::NonZeroUsize::get)
+ .to_string()
+ }),
+ );
+ compiletest::run_tests(&config);
++ check_rustfix_coverage();
+}
+
+fn run_internal_tests() {
+ // only run internal tests with the internal-tests feature
+ if !RUN_INTERNAL_TESTS {
+ return;
+ }
+ let config = base_config("ui-internal");
+ compiletest::run_tests(&config);
+}
+
+fn run_ui_toml() {
+ fn run_tests(config: &compiletest::Config, mut tests: Vec<tester::TestDescAndFn>) -> Result<bool, io::Error> {
+ let mut result = true;
+ let opts = compiletest::test_opts(config);
+ for dir in fs::read_dir(&config.src_base)? {
+ let dir = dir?;
+ if !dir.file_type()?.is_dir() {
+ continue;
+ }
+ let dir_path = dir.path();
+ let _g = VarGuard::set("CARGO_MANIFEST_DIR", &dir_path);
+ for file in fs::read_dir(&dir_path)? {
+ let file = file?;
+ let file_path = file.path();
+ if file.file_type()?.is_dir() {
+ continue;
+ }
+ if file_path.extension() != Some(OsStr::new("rs")) {
+ continue;
+ }
+ let paths = compiletest::common::TestPaths {
+ file: file_path,
+ base: config.src_base.clone(),
+ relative_dir: dir_path.file_name().unwrap().into(),
+ };
+ let test_name = compiletest::make_test_name(config, &paths);
+ let index = tests
+ .iter()
+ .position(|test| test.desc.name == test_name)
+ .expect("The test should be in there");
+ result &= tester::run_tests_console(&opts, vec![tests.swap_remove(index)])?;
+ }
+ }
+ Ok(result)
+ }
+
+ let mut config = base_config("ui-toml");
+ config.src_base = config.src_base.canonicalize().unwrap();
+
+ let tests = compiletest::make_tests(&config);
+
+ let res = run_tests(&config, tests);
+ match res {
+ Ok(true) => {},
+ Ok(false) => panic!("Some tests failed"),
+ Err(e) => {
+ panic!("I/O failure during tests: {:?}", e);
+ },
+ }
+}
+
+fn run_ui_cargo() {
+ fn run_tests(
+ config: &compiletest::Config,
+ filters: &[String],
+ mut tests: Vec<tester::TestDescAndFn>,
+ ) -> Result<bool, io::Error> {
+ let mut result = true;
+ let opts = compiletest::test_opts(config);
+
+ for dir in fs::read_dir(&config.src_base)? {
+ let dir = dir?;
+ if !dir.file_type()?.is_dir() {
+ continue;
+ }
+
+ // Use the filter if provided
+ let dir_path = dir.path();
+ for filter in filters {
+ if !dir_path.ends_with(filter) {
+ continue;
+ }
+ }
+
+ for case in fs::read_dir(&dir_path)? {
+ let case = case?;
+ if !case.file_type()?.is_dir() {
+ continue;
+ }
+
+ let src_path = case.path().join("src");
+
+ // When switching between branches, if the previous branch had a test
+ // that the current branch does not have, the directory is not removed
+ // because an ignored Cargo.lock file exists.
+ if !src_path.exists() {
+ continue;
+ }
+
+ env::set_current_dir(&src_path)?;
+ for file in fs::read_dir(&src_path)? {
+ let file = file?;
+ if file.file_type()?.is_dir() {
+ continue;
+ }
+
+ // Search for the main file to avoid running a test for each file in the project
+ let file_path = file.path();
+ match file_path.file_name().and_then(OsStr::to_str) {
+ Some("main.rs") => {},
+ _ => continue,
+ }
+ let _g = VarGuard::set("CLIPPY_CONF_DIR", case.path());
+ let paths = compiletest::common::TestPaths {
+ file: file_path,
+ base: config.src_base.clone(),
+ relative_dir: src_path.strip_prefix(&config.src_base).unwrap().into(),
+ };
+ let test_name = compiletest::make_test_name(config, &paths);
+ let index = tests
+ .iter()
+ .position(|test| test.desc.name == test_name)
+ .expect("The test should be in there");
+ result &= tester::run_tests_console(&opts, vec![tests.swap_remove(index)])?;
+ }
+ }
+ }
+ Ok(result)
+ }
+
+ if IS_RUSTC_TEST_SUITE {
+ return;
+ }
+
+ let mut config = base_config("ui-cargo");
+ config.src_base = config.src_base.canonicalize().unwrap();
+
+ let tests = compiletest::make_tests(&config);
+
+ let current_dir = env::current_dir().unwrap();
+ let res = run_tests(&config, &config.filters, tests);
+ env::set_current_dir(current_dir).unwrap();
+
+ match res {
+ Ok(true) => {},
+ Ok(false) => panic!("Some tests failed"),
+ Err(e) => {
+ panic!("I/O failure during tests: {:?}", e);
+ },
+ }
+}
+
+#[test]
+fn compile_test() {
+ set_var("CLIPPY_DISABLE_DOCS_LINKS", "true");
+ run_ui();
+ run_ui_toml();
+ run_ui_cargo();
+ run_internal_tests();
+}
+
++const RUSTFIX_COVERAGE_KNOWN_EXCEPTIONS: &[&str] = &[
++ "assign_ops2.rs",
++ "borrow_deref_ref_unfixable.rs",
++ "cast_size_32bit.rs",
++ "char_lit_as_u8.rs",
++ "cmp_owned/without_suggestion.rs",
++ "dbg_macro.rs",
++ "deref_addrof_double_trigger.rs",
++ "doc/unbalanced_ticks.rs",
++ "eprint_with_newline.rs",
++ "explicit_counter_loop.rs",
++ "iter_skip_next_unfixable.rs",
++ "let_and_return.rs",
++ "literals.rs",
++ "map_flatten.rs",
++ "map_unwrap_or.rs",
++ "match_bool.rs",
++ "mem_replace_macro.rs",
++ "needless_arbitrary_self_type_unfixable.rs",
++ "needless_borrow_pat.rs",
++ "needless_for_each_unfixable.rs",
++ "nonminimal_bool.rs",
++ "print_literal.rs",
++ "print_with_newline.rs",
++ "redundant_static_lifetimes_multiple.rs",
++ "ref_binding_to_reference.rs",
++ "repl_uninit.rs",
++ "result_map_unit_fn_unfixable.rs",
++ "search_is_some.rs",
++ "single_component_path_imports_nested_first.rs",
++ "string_add.rs",
++ "toplevel_ref_arg_non_rustfix.rs",
++ "unit_arg.rs",
++ "unnecessary_clone.rs",
++ "unnecessary_lazy_eval_unfixable.rs",
++ "write_literal.rs",
++ "write_literal_2.rs",
++ "write_with_newline.rs",
++];
++
++fn check_rustfix_coverage() {
++ let missing_coverage_path = Path::new("target/debug/test/ui/rustfix_missing_coverage.txt");
++
++ if let Ok(missing_coverage_contents) = std::fs::read_to_string(missing_coverage_path) {
++ assert!(RUSTFIX_COVERAGE_KNOWN_EXCEPTIONS.iter().is_sorted_by_key(Path::new));
++
++ for rs_path in missing_coverage_contents.lines() {
++ if Path::new(rs_path).starts_with("tests/ui/crashes") {
++ continue;
++ }
++ let filename = Path::new(rs_path).strip_prefix("tests/ui/").unwrap();
++ assert!(
++ RUSTFIX_COVERAGE_KNOWN_EXCEPTIONS
++ .binary_search_by_key(&filename, Path::new)
++ .is_ok(),
++ "`{}` runs `MachineApplicable` diagnostics but is missing a `run-rustfix` annotation. \
++ Please either add `// run-rustfix` at the top of the file or add the file to \
++ `RUSTFIX_COVERAGE_KNOWN_EXCEPTIONS` in `tests/compile-test.rs`.",
++ rs_path,
++ );
++ }
++ }
++}
++
++#[test]
++fn rustfix_coverage_known_exceptions_accuracy() {
++ for filename in RUSTFIX_COVERAGE_KNOWN_EXCEPTIONS {
++ let rs_path = Path::new("tests/ui").join(filename);
++ assert!(
++ rs_path.exists(),
++ "`{}` does not exists",
++ rs_path.strip_prefix(env!("CARGO_MANIFEST_DIR")).unwrap().display()
++ );
++ let fixed_path = rs_path.with_extension("fixed");
++ assert!(
++ !fixed_path.exists(),
++ "`{}` exists",
++ fixed_path.strip_prefix(env!("CARGO_MANIFEST_DIR")).unwrap().display()
++ );
++ }
++}
++
+/// Restores an env var on drop
+#[must_use]
+struct VarGuard {
+ key: &'static str,
+ value: Option<OsString>,
+}
+
+impl VarGuard {
+ fn set(key: &'static str, val: impl AsRef<OsStr>) -> Self {
+ let value = var_os(key);
+ set_var(key, val);
+ Self { key, value }
+ }
+}
+
+impl Drop for VarGuard {
+ fn drop(&mut self) {
+ match self.value.as_deref() {
+ None => remove_var(self.key),
+ Some(value) => set_var(self.key, value),
+ }
+ }
+}
--- /dev/null
+// run-rustfix
+#![feature(rustc_private)]
+#![deny(clippy::internal)]
+#![allow(
++ clippy::borrow_deref_ref,
+ clippy::unnecessary_operation,
+ unused_must_use,
+ clippy::missing_clippy_version_attribute
+)]
+
+extern crate rustc_span;
+
+use rustc_span::symbol::{Ident, Symbol};
+
+fn main() {
+ Symbol::intern("foo") == rustc_span::sym::clippy;
+ Symbol::intern("foo") == rustc_span::symbol::kw::SelfLower;
+ Symbol::intern("foo") != rustc_span::symbol::kw::SelfUpper;
+ Ident::empty().name == rustc_span::sym::clippy;
+ rustc_span::sym::clippy == Ident::empty().name;
+}
--- /dev/null
+// run-rustfix
+#![feature(rustc_private)]
+#![deny(clippy::internal)]
+#![allow(
++ clippy::borrow_deref_ref,
+ clippy::unnecessary_operation,
+ unused_must_use,
+ clippy::missing_clippy_version_attribute
+)]
+
+extern crate rustc_span;
+
+use rustc_span::symbol::{Ident, Symbol};
+
+fn main() {
+ Symbol::intern("foo").as_str() == "clippy";
+ Symbol::intern("foo").to_string() == "self";
+ Symbol::intern("foo").to_ident_string() != "Self";
+ &*Ident::empty().as_str() == "clippy";
+ "clippy" == Ident::empty().to_string();
+}
--- /dev/null
- --> $DIR/unnecessary_symbol_str.rs:15:5
+error: unnecessary `Symbol` to string conversion
- --> $DIR/unnecessary_symbol_str.rs:16:5
++ --> $DIR/unnecessary_symbol_str.rs:16:5
+ |
+LL | Symbol::intern("foo").as_str() == "clippy";
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Symbol::intern("foo") == rustc_span::sym::clippy`
+ |
+note: the lint level is defined here
+ --> $DIR/unnecessary_symbol_str.rs:3:9
+ |
+LL | #![deny(clippy::internal)]
+ | ^^^^^^^^^^^^^^^^
+ = note: `#[deny(clippy::unnecessary_symbol_str)]` implied by `#[deny(clippy::internal)]`
+
+error: unnecessary `Symbol` to string conversion
- --> $DIR/unnecessary_symbol_str.rs:17:5
++ --> $DIR/unnecessary_symbol_str.rs:17:5
+ |
+LL | Symbol::intern("foo").to_string() == "self";
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Symbol::intern("foo") == rustc_span::symbol::kw::SelfLower`
+
+error: unnecessary `Symbol` to string conversion
- --> $DIR/unnecessary_symbol_str.rs:18:5
++ --> $DIR/unnecessary_symbol_str.rs:18:5
+ |
+LL | Symbol::intern("foo").to_ident_string() != "Self";
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Symbol::intern("foo") != rustc_span::symbol::kw::SelfUpper`
+
+error: unnecessary `Symbol` to string conversion
- --> $DIR/unnecessary_symbol_str.rs:19:5
++ --> $DIR/unnecessary_symbol_str.rs:19:5
+ |
+LL | &*Ident::empty().as_str() == "clippy";
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Ident::empty().name == rustc_span::sym::clippy`
+
+error: unnecessary `Symbol` to string conversion
++ --> $DIR/unnecessary_symbol_str.rs:20:5
+ |
+LL | "clippy" == Ident::empty().to_string();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `rustc_span::sym::clippy == Ident::empty().name`
+
+error: aborting due to 5 previous errors
+
--- /dev/null
--- /dev/null
++allow-dbg-in-tests = true
--- /dev/null
--- /dev/null
++// compile-flags: --test
++#![warn(clippy::dbg_macro)]
++
++fn foo(n: u32) -> u32 {
++ if let Some(n) = dbg!(n.checked_sub(4)) { n } else { n }
++}
++
++fn factorial(n: u32) -> u32 {
++ if dbg!(n <= 1) {
++ dbg!(1)
++ } else {
++ dbg!(n * factorial(n - 1))
++ }
++}
++
++fn main() {
++ dbg!(42);
++ dbg!(dbg!(dbg!(42)));
++ foo(3) + dbg!(factorial(4));
++ dbg!(1, 2, dbg!(3, 4));
++ dbg!(1, 2, 3, 4, 5);
++}
++
++#[test]
++pub fn issue8481() {
++ dbg!(1);
++}
++
++#[cfg(test)]
++fn foo2() {
++ dbg!(1);
++}
++
++#[cfg(test)]
++mod mod1 {
++ fn func() {
++ dbg!(1);
++ }
++}
--- /dev/null
--- /dev/null
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:5:22
++ |
++LL | if let Some(n) = dbg!(n.checked_sub(4)) { n } else { n }
++ | ^^^^^^^^^^^^^^^^^^^^^^
++ |
++ = note: `-D clippy::dbg-macro` implied by `-D warnings`
++help: ensure to avoid having uses of it in version control
++ |
++LL | if let Some(n) = n.checked_sub(4) { n } else { n }
++ | ~~~~~~~~~~~~~~~~
++
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:9:8
++ |
++LL | if dbg!(n <= 1) {
++ | ^^^^^^^^^^^^
++ |
++help: ensure to avoid having uses of it in version control
++ |
++LL | if n <= 1 {
++ | ~~~~~~
++
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:10:9
++ |
++LL | dbg!(1)
++ | ^^^^^^^
++ |
++help: ensure to avoid having uses of it in version control
++ |
++LL | 1
++ |
++
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:12:9
++ |
++LL | dbg!(n * factorial(n - 1))
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^
++ |
++help: ensure to avoid having uses of it in version control
++ |
++LL | n * factorial(n - 1)
++ |
++
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:17:5
++ |
++LL | dbg!(42);
++ | ^^^^^^^^
++ |
++help: ensure to avoid having uses of it in version control
++ |
++LL | 42;
++ | ~~
++
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:18:5
++ |
++LL | dbg!(dbg!(dbg!(42)));
++ | ^^^^^^^^^^^^^^^^^^^^
++ |
++help: ensure to avoid having uses of it in version control
++ |
++LL | dbg!(dbg!(42));
++ | ~~~~~~~~~~~~~~
++
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:19:14
++ |
++LL | foo(3) + dbg!(factorial(4));
++ | ^^^^^^^^^^^^^^^^^^
++ |
++help: ensure to avoid having uses of it in version control
++ |
++LL | foo(3) + factorial(4);
++ | ~~~~~~~~~~~~
++
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:20:5
++ |
++LL | dbg!(1, 2, dbg!(3, 4));
++ | ^^^^^^^^^^^^^^^^^^^^^^
++ |
++help: ensure to avoid having uses of it in version control
++ |
++LL | (1, 2, dbg!(3, 4));
++ | ~~~~~~~~~~~~~~~~~~
++
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:21:5
++ |
++LL | dbg!(1, 2, 3, 4, 5);
++ | ^^^^^^^^^^^^^^^^^^^
++ |
++help: ensure to avoid having uses of it in version control
++ |
++LL | (1, 2, 3, 4, 5);
++ | ~~~~~~~~~~~~~~~
++
++error: aborting due to 9 previous errors
++
--- /dev/null
+error: error reading Clippy's configuration file `$DIR/clippy.toml`: unknown field `foobar`, expected one of
++ allow-dbg-in-tests
+ allow-expect-in-tests
+ allow-unwrap-in-tests
+ allowed-scripts
+ array-size-threshold
+ avoid-breaking-exported-api
+ await-holding-invalid-types
+ blacklisted-names
+ cargo-ignore-publish
+ cognitive-complexity-threshold
+ cyclomatic-complexity-threshold
+ disallowed-methods
+ disallowed-types
+ doc-valid-idents
+ enable-raw-pointer-heuristic-for-send
+ enforced-import-renames
+ enum-variant-name-threshold
+ enum-variant-size-threshold
+ literal-representation-threshold
+ max-fn-params-bools
+ max-include-file-size
+ max-struct-bools
+ max-suggested-slice-pattern-length
+ max-trait-bounds
+ msrv
+ pass-by-value-size-limit
+ single-char-binding-names-threshold
+ standard-macro-braces
+ third-party
+ too-large-for-stack
+ too-many-arguments-threshold
+ too-many-lines-threshold
+ trivial-copy-size-limit
+ type-complexity-threshold
+ unreadable-literal-lint-fractions
+ upper-case-acronyms-aggressive
+ vec-box-size-threshold
+ verbose-bit-mask-threshold
+ warn-on-all-wildcard-imports
+ at line 5 column 1
+
+error: aborting due to previous error
+
--- /dev/null
- #![allow(unused_mut, clippy::from_iter_instead_of_collect)]
+// compile-flags: --test
+
++#![allow(unused_mut, clippy::get_first, clippy::from_iter_instead_of_collect)]
+#![warn(clippy::unwrap_used)]
+#![deny(clippy::get_unwrap)]
+
+use std::collections::BTreeMap;
+use std::collections::HashMap;
+use std::collections::VecDeque;
+
+struct GetFalsePositive {
+ arr: [u32; 3],
+}
+
+impl GetFalsePositive {
+ fn get(&self, pos: usize) -> Option<&u32> {
+ self.arr.get(pos)
+ }
+ fn get_mut(&mut self, pos: usize) -> Option<&mut u32> {
+ self.arr.get_mut(pos)
+ }
+}
+
+fn main() {
+ let mut boxed_slice: Box<[u8]> = Box::new([0, 1, 2, 3]);
+ let mut some_slice = &mut [0, 1, 2, 3];
+ let mut some_vec = vec![0, 1, 2, 3];
+ let mut some_vecdeque: VecDeque<_> = some_vec.iter().cloned().collect();
+ let mut some_hashmap: HashMap<u8, char> = HashMap::from_iter(vec![(1, 'a'), (2, 'b')]);
+ let mut some_btreemap: BTreeMap<u8, char> = BTreeMap::from_iter(vec![(1, 'a'), (2, 'b')]);
+ let mut false_positive = GetFalsePositive { arr: [0, 1, 2] };
+
+ {
+ // Test `get().unwrap()`
+ let _ = boxed_slice.get(1).unwrap();
+ let _ = some_slice.get(0).unwrap();
+ let _ = some_vec.get(0).unwrap();
+ let _ = some_vecdeque.get(0).unwrap();
+ let _ = some_hashmap.get(&1).unwrap();
+ let _ = some_btreemap.get(&1).unwrap();
+ #[allow(clippy::unwrap_used)]
+ let _ = false_positive.get(0).unwrap();
+ // Test with deref
+ let _: u8 = *boxed_slice.get(1).unwrap();
+ }
+
+ {
+ // Test `get_mut().unwrap()`
+ *boxed_slice.get_mut(0).unwrap() = 1;
+ *some_slice.get_mut(0).unwrap() = 1;
+ *some_vec.get_mut(0).unwrap() = 1;
+ *some_vecdeque.get_mut(0).unwrap() = 1;
+ // Check false positives
+ #[allow(clippy::unwrap_used)]
+ {
+ *some_hashmap.get_mut(&1).unwrap() = 'b';
+ *some_btreemap.get_mut(&1).unwrap() = 'b';
+ *false_positive.get_mut(0).unwrap() = 1;
+ }
+ }
+
+ {
+ // Test `get().unwrap().foo()` and `get_mut().unwrap().bar()`
+ let _ = some_vec.get(0..1).unwrap().to_vec();
+ let _ = some_vec.get_mut(0..1).unwrap().to_vec();
+ }
+}
+
+#[test]
+fn test() {
+ let boxed_slice: Box<[u8]> = Box::new([0, 1, 2, 3]);
+ let _ = boxed_slice.get(1).unwrap();
+}
--- /dev/null
--- /dev/null
++// run-rustfix
++// edition:2018
++
++#![feature(custom_inner_attributes)]
++#![feature(exclusive_range_pattern)]
++#![feature(stmt_expr_attributes)]
++#![warn(clippy::almost_complete_letter_range)]
++#![allow(ellipsis_inclusive_range_patterns)]
++
++macro_rules! a {
++ () => {
++ 'a'
++ };
++}
++
++fn main() {
++ #[rustfmt::skip]
++ {
++ let _ = ('a') ..='z';
++ let _ = 'A' ..= ('Z');
++ }
++
++ let _ = 'b'..'z';
++ let _ = 'B'..'Z';
++
++ let _ = (b'a')..=(b'z');
++ let _ = b'A'..=b'Z';
++
++ let _ = b'b'..b'z';
++ let _ = b'B'..b'Z';
++
++ let _ = a!()..='z';
++
++ let _ = match 0u8 {
++ b'a'..=b'z' if true => 1,
++ b'A'..=b'Z' if true => 2,
++ b'b'..b'z' => 3,
++ b'B'..b'Z' => 4,
++ _ => 5,
++ };
++
++ let _ = match 'x' {
++ 'a'..='z' if true => 1,
++ 'A'..='Z' if true => 2,
++ 'b'..'z' => 3,
++ 'B'..'Z' => 4,
++ _ => 5,
++ };
++}
++
++fn _under_msrv() {
++ #![clippy::msrv = "1.25"]
++ let _ = match 'a' {
++ 'a'...'z' => 1,
++ _ => 2,
++ };
++}
++
++fn _meets_msrv() {
++ #![clippy::msrv = "1.26"]
++ let _ = 'a'..='z';
++ let _ = match 'a' {
++ 'a'..='z' => 1,
++ _ => 2,
++ };
++}
--- /dev/null
--- /dev/null
++// run-rustfix
++// edition:2018
++
++#![feature(custom_inner_attributes)]
++#![feature(exclusive_range_pattern)]
++#![feature(stmt_expr_attributes)]
++#![warn(clippy::almost_complete_letter_range)]
++#![allow(ellipsis_inclusive_range_patterns)]
++
++macro_rules! a {
++ () => {
++ 'a'
++ };
++}
++
++fn main() {
++ #[rustfmt::skip]
++ {
++ let _ = ('a') ..'z';
++ let _ = 'A' .. ('Z');
++ }
++
++ let _ = 'b'..'z';
++ let _ = 'B'..'Z';
++
++ let _ = (b'a')..(b'z');
++ let _ = b'A'..b'Z';
++
++ let _ = b'b'..b'z';
++ let _ = b'B'..b'Z';
++
++ let _ = a!()..'z';
++
++ let _ = match 0u8 {
++ b'a'..b'z' if true => 1,
++ b'A'..b'Z' if true => 2,
++ b'b'..b'z' => 3,
++ b'B'..b'Z' => 4,
++ _ => 5,
++ };
++
++ let _ = match 'x' {
++ 'a'..'z' if true => 1,
++ 'A'..'Z' if true => 2,
++ 'b'..'z' => 3,
++ 'B'..'Z' => 4,
++ _ => 5,
++ };
++}
++
++fn _under_msrv() {
++ #![clippy::msrv = "1.25"]
++ let _ = match 'a' {
++ 'a'..'z' => 1,
++ _ => 2,
++ };
++}
++
++fn _meets_msrv() {
++ #![clippy::msrv = "1.26"]
++ let _ = 'a'..'z';
++ let _ = match 'a' {
++ 'a'..'z' => 1,
++ _ => 2,
++ };
++}
--- /dev/null
--- /dev/null
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:19:17
++ |
++LL | let _ = ('a') ..'z';
++ | ^^^^^^--^^^
++ | |
++ | help: use an inclusive range: `..=`
++ |
++ = note: `-D clippy::almost-complete-letter-range` implied by `-D warnings`
++
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:20:17
++ |
++LL | let _ = 'A' .. ('Z');
++ | ^^^^--^^^^^^
++ | |
++ | help: use an inclusive range: `..=`
++
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:26:13
++ |
++LL | let _ = (b'a')..(b'z');
++ | ^^^^^^--^^^^^^
++ | |
++ | help: use an inclusive range: `..=`
++
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:27:13
++ |
++LL | let _ = b'A'..b'Z';
++ | ^^^^--^^^^
++ | |
++ | help: use an inclusive range: `..=`
++
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:32:13
++ |
++LL | let _ = a!()..'z';
++ | ^^^^--^^^
++ | |
++ | help: use an inclusive range: `..=`
++
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:35:9
++ |
++LL | b'a'..b'z' if true => 1,
++ | ^^^^--^^^^
++ | |
++ | help: use an inclusive range: `..=`
++
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:36:9
++ |
++LL | b'A'..b'Z' if true => 2,
++ | ^^^^--^^^^
++ | |
++ | help: use an inclusive range: `..=`
++
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:43:9
++ |
++LL | 'a'..'z' if true => 1,
++ | ^^^--^^^
++ | |
++ | help: use an inclusive range: `..=`
++
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:44:9
++ |
++LL | 'A'..'Z' if true => 2,
++ | ^^^--^^^
++ | |
++ | help: use an inclusive range: `..=`
++
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:54:9
++ |
++LL | 'a'..'z' => 1,
++ | ^^^--^^^
++ | |
++ | help: use an inclusive range: `...`
++
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:61:13
++ |
++LL | let _ = 'a'..'z';
++ | ^^^--^^^
++ | |
++ | help: use an inclusive range: `..=`
++
++error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:63:9
++ |
++LL | 'a'..'z' => 1,
++ | ^^^--^^^
++ | |
++ | help: use an inclusive range: `..=`
++
++error: aborting due to 12 previous errors
++
--- /dev/null
--- /dev/null
++// run-rustfix
++
++#![warn(clippy::as_underscore)]
++
++fn foo(_n: usize) {}
++
++fn main() {
++ let n: u16 = 256;
++ foo(n as usize);
++
++ let n = 0_u128;
++ let _n: u8 = n as u8;
++}
--- /dev/null
--- /dev/null
++// run-rustfix
++
++#![warn(clippy::as_underscore)]
++
++fn foo(_n: usize) {}
++
++fn main() {
++ let n: u16 = 256;
++ foo(n as _);
++
++ let n = 0_u128;
++ let _n: u8 = n as _;
++}
--- /dev/null
--- /dev/null
++error: using `as _` conversion
++ --> $DIR/as_underscore.rs:9:9
++ |
++LL | foo(n as _);
++ | ^^^^^-
++ | |
++ | help: consider giving the type explicitly: `usize`
++ |
++ = note: `-D clippy::as-underscore` implied by `-D warnings`
++
++error: using `as _` conversion
++ --> $DIR/as_underscore.rs:12:18
++ |
++LL | let _n: u8 = n as _;
++ | ^^^^^-
++ | |
++ | help: consider giving the type explicitly: `u8`
++
++error: aborting due to 2 previous errors
++
--- /dev/null
--- /dev/null
++// run-rustfix
++#![deny(clippy::bind_instead_of_map)]
++#![allow(clippy::blocks_in_if_conditions)]
++
++pub fn main() {
++ let _ = Some("42").map(|s| if s.len() < 42 { 0 } else { s.len() });
++ let _ = Some("42").and_then(|s| if s.len() < 42 { None } else { Some(s.len()) });
++
++ let _ = Ok::<_, ()>("42").map(|s| if s.len() < 42 { 0 } else { s.len() });
++ let _ = Ok::<_, ()>("42").and_then(|s| if s.len() < 42 { Err(()) } else { Ok(s.len()) });
++
++ let _ = Err::<(), _>("42").map_err(|s| if s.len() < 42 { s.len() + 20 } else { s.len() });
++ let _ = Err::<(), _>("42").or_else(|s| if s.len() < 42 { Ok(()) } else { Err(s.len()) });
++
++ hard_example();
++ macro_example();
++}
++
++fn hard_example() {
++ Some("42").map(|s| {
++ if {
++ if s == "43" {
++ return 43;
++ }
++ s == "42"
++ } {
++ return 45;
++ }
++ match s.len() {
++ 10 => 2,
++ 20 => {
++ if foo() {
++ return {
++ if foo() {
++ return 20;
++ }
++ println!("foo");
++ 3
++ };
++ }
++ 20
++ },
++ 40 => 30,
++ _ => 1,
++ }
++ });
++}
++
++fn foo() -> bool {
++ true
++}
++
++macro_rules! m {
++ () => {
++ Some(10)
++ };
++}
++
++fn macro_example() {
++ let _ = Some("").and_then(|s| if s.len() == 20 { m!() } else { Some(20) });
++ let _ = Some("").map(|s| if s.len() == 20 { m!() } else { Some(20) });
++}
--- /dev/null
++// run-rustfix
+#![deny(clippy::bind_instead_of_map)]
+#![allow(clippy::blocks_in_if_conditions)]
+
+pub fn main() {
+ let _ = Some("42").and_then(|s| if s.len() < 42 { Some(0) } else { Some(s.len()) });
+ let _ = Some("42").and_then(|s| if s.len() < 42 { None } else { Some(s.len()) });
+
+ let _ = Ok::<_, ()>("42").and_then(|s| if s.len() < 42 { Ok(0) } else { Ok(s.len()) });
+ let _ = Ok::<_, ()>("42").and_then(|s| if s.len() < 42 { Err(()) } else { Ok(s.len()) });
+
+ let _ = Err::<(), _>("42").or_else(|s| if s.len() < 42 { Err(s.len() + 20) } else { Err(s.len()) });
+ let _ = Err::<(), _>("42").or_else(|s| if s.len() < 42 { Ok(()) } else { Err(s.len()) });
+
+ hard_example();
+ macro_example();
+}
+
+fn hard_example() {
+ Some("42").and_then(|s| {
+ if {
+ if s == "43" {
+ return Some(43);
+ }
+ s == "42"
+ } {
+ return Some(45);
+ }
+ match s.len() {
+ 10 => Some(2),
+ 20 => {
+ if foo() {
+ return {
+ if foo() {
+ return Some(20);
+ }
+ println!("foo");
+ Some(3)
+ };
+ }
+ Some(20)
+ },
+ 40 => Some(30),
+ _ => Some(1),
+ }
+ });
+}
+
+fn foo() -> bool {
+ true
+}
+
+macro_rules! m {
+ () => {
+ Some(10)
+ };
+}
+
+fn macro_example() {
+ let _ = Some("").and_then(|s| if s.len() == 20 { m!() } else { Some(20) });
+ let _ = Some("").and_then(|s| if s.len() == 20 { Some(m!()) } else { Some(Some(20)) });
+}
--- /dev/null
- --> $DIR/bind_instead_of_map_multipart.rs:5:13
+error: using `Option.and_then(|x| Some(y))`, which is more succinctly expressed as `map(|x| y)`
- --> $DIR/bind_instead_of_map_multipart.rs:1:9
++ --> $DIR/bind_instead_of_map_multipart.rs:6:13
+ |
+LL | let _ = Some("42").and_then(|s| if s.len() < 42 { Some(0) } else { Some(s.len()) });
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+note: the lint level is defined here
- --> $DIR/bind_instead_of_map_multipart.rs:8:13
++ --> $DIR/bind_instead_of_map_multipart.rs:2:9
+ |
+LL | #![deny(clippy::bind_instead_of_map)]
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: try this
+ |
+LL | let _ = Some("42").map(|s| if s.len() < 42 { 0 } else { s.len() });
+ | ~~~ ~ ~~~~~~~
+
+error: using `Result.and_then(|x| Ok(y))`, which is more succinctly expressed as `map(|x| y)`
- --> $DIR/bind_instead_of_map_multipart.rs:11:13
++ --> $DIR/bind_instead_of_map_multipart.rs:9:13
+ |
+LL | let _ = Ok::<_, ()>("42").and_then(|s| if s.len() < 42 { Ok(0) } else { Ok(s.len()) });
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try this
+ |
+LL | let _ = Ok::<_, ()>("42").map(|s| if s.len() < 42 { 0 } else { s.len() });
+ | ~~~ ~ ~~~~~~~
+
+error: using `Result.or_else(|x| Err(y))`, which is more succinctly expressed as `map_err(|x| y)`
- --> $DIR/bind_instead_of_map_multipart.rs:19:5
++ --> $DIR/bind_instead_of_map_multipart.rs:12:13
+ |
+LL | let _ = Err::<(), _>("42").or_else(|s| if s.len() < 42 { Err(s.len() + 20) } else { Err(s.len()) });
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try this
+ |
+LL | let _ = Err::<(), _>("42").map_err(|s| if s.len() < 42 { s.len() + 20 } else { s.len() });
+ | ~~~~~~~ ~~~~~~~~~~~~ ~~~~~~~
+
+error: using `Option.and_then(|x| Some(y))`, which is more succinctly expressed as `map(|x| y)`
- --> $DIR/bind_instead_of_map_multipart.rs:60:13
++ --> $DIR/bind_instead_of_map_multipart.rs:20:5
+ |
+LL | / Some("42").and_then(|s| {
+LL | | if {
+LL | | if s == "43" {
+LL | | return Some(43);
+... |
+LL | | }
+LL | | });
+ | |______^
+ |
+help: try this
+ |
+LL ~ Some("42").map(|s| {
+LL | if {
+LL | if s == "43" {
+LL ~ return 43;
+LL | }
+LL | s == "42"
+ ...
+
+error: using `Option.and_then(|x| Some(y))`, which is more succinctly expressed as `map(|x| y)`
++ --> $DIR/bind_instead_of_map_multipart.rs:61:13
+ |
+LL | let _ = Some("").and_then(|s| if s.len() == 20 { Some(m!()) } else { Some(Some(20)) });
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try this
+ |
+LL | let _ = Some("").map(|s| if s.len() == 20 { m!() } else { Some(20) });
+ | ~~~ ~~~~ ~~~~~~~~
+
+error: aborting due to 5 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++
++#![allow(dead_code, unused_variables)]
++
++fn main() {}
++
++mod should_lint {
++ fn one_help() {
++ let a = &12;
++ let b = a;
++
++ let b = &mut bar(&12);
++ }
++
++ fn bar(x: &u32) -> &u32 {
++ x
++ }
++}
++
++// this mod explains why we should not lint `&mut &* (&T)`
++mod should_not_lint1 {
++ fn foo(x: &mut &u32) {
++ *x = &1;
++ }
++
++ fn main() {
++ let mut x = &0;
++ foo(&mut &*x); // should not lint
++ assert_eq!(*x, 0);
++
++ foo(&mut x);
++ assert_eq!(*x, 1);
++ }
++}
++
++// similar to should_not_lint1
++mod should_not_lint2 {
++ struct S<'a> {
++ a: &'a u32,
++ b: u32,
++ }
++
++ fn main() {
++ let s = S { a: &1, b: 1 };
++ let x = &mut &*s.a;
++ *x = &2;
++ }
++}
++
++// this mod explains why we should not lint `& &* (&T)`
++mod false_negative {
++ fn foo() {
++ let x = &12;
++ let addr_x = &x as *const _ as usize;
++ let addr_y = &x as *const _ as usize; // assert ok
++ // let addr_y = &x as *const _ as usize; // assert fail
++ assert_ne!(addr_x, addr_y);
++ }
++}
--- /dev/null
--- /dev/null
++// run-rustfix
++
++#![allow(dead_code, unused_variables)]
++
++fn main() {}
++
++mod should_lint {
++ fn one_help() {
++ let a = &12;
++ let b = &*a;
++
++ let b = &mut &*bar(&12);
++ }
++
++ fn bar(x: &u32) -> &u32 {
++ x
++ }
++}
++
++// this mod explains why we should not lint `&mut &* (&T)`
++mod should_not_lint1 {
++ fn foo(x: &mut &u32) {
++ *x = &1;
++ }
++
++ fn main() {
++ let mut x = &0;
++ foo(&mut &*x); // should not lint
++ assert_eq!(*x, 0);
++
++ foo(&mut x);
++ assert_eq!(*x, 1);
++ }
++}
++
++// similar to should_not_lint1
++mod should_not_lint2 {
++ struct S<'a> {
++ a: &'a u32,
++ b: u32,
++ }
++
++ fn main() {
++ let s = S { a: &1, b: 1 };
++ let x = &mut &*s.a;
++ *x = &2;
++ }
++}
++
++// this mod explains why we should not lint `& &* (&T)`
++mod false_negative {
++ fn foo() {
++ let x = &12;
++ let addr_x = &x as *const _ as usize;
++ let addr_y = &&*x as *const _ as usize; // assert ok
++ // let addr_y = &x as *const _ as usize; // assert fail
++ assert_ne!(addr_x, addr_y);
++ }
++}
--- /dev/null
--- /dev/null
++error: deref on an immutable reference
++ --> $DIR/borrow_deref_ref.rs:10:17
++ |
++LL | let b = &*a;
++ | ^^^ help: if you would like to reborrow, try removing `&*`: `a`
++ |
++ = note: `-D clippy::borrow-deref-ref` implied by `-D warnings`
++
++error: deref on an immutable reference
++ --> $DIR/borrow_deref_ref.rs:12:22
++ |
++LL | let b = &mut &*bar(&12);
++ | ^^^^^^^^^^ help: if you would like to reborrow, try removing `&*`: `bar(&12)`
++
++error: deref on an immutable reference
++ --> $DIR/borrow_deref_ref.rs:55:23
++ |
++LL | let addr_y = &&*x as *const _ as usize; // assert ok
++ | ^^^ help: if you would like to reborrow, try removing `&*`: `x`
++
++error: aborting due to 3 previous errors
++
--- /dev/null
--- /dev/null
++#![allow(dead_code, unused_variables)]
++
++fn main() {}
++
++mod should_lint {
++ fn two_helps() {
++ let s = &String::new();
++ let x: &str = &*s;
++ }
++}
--- /dev/null
--- /dev/null
++error: deref on an immutable reference
++ --> $DIR/borrow_deref_ref_unfixable.rs:8:23
++ |
++LL | let x: &str = &*s;
++ | ^^^
++ |
++ = note: `-D clippy::borrow-deref-ref` implied by `-D warnings`
++help: if you would like to reborrow, try removing `&*`
++ |
++LL | let x: &str = s;
++ | ~
++help: if you would like to deref, try using `&**`
++ |
++LL | let x: &str = &**s;
++ | ~~~~
++
++error: aborting due to previous error
++
--- /dev/null
+// run-rustfix
+#![warn(clippy::cast_abs_to_unsigned)]
+
+fn main() {
+ let x: i32 = -42;
+ let y: u32 = x.unsigned_abs();
+ println!("The absolute value of {} is {}", x, y);
++
++ let a: i32 = -3;
++ let _: usize = a.unsigned_abs() as usize;
++ let _: usize = a.unsigned_abs() as _;
++ let _ = a.unsigned_abs() as usize;
++
++ let a: i64 = -3;
++ let _ = a.unsigned_abs() as usize;
++ let _ = a.unsigned_abs() as u8;
++ let _ = a.unsigned_abs() as u16;
++ let _ = a.unsigned_abs() as u32;
++ let _ = a.unsigned_abs();
++ let _ = a.unsigned_abs() as u128;
++
++ let a: isize = -3;
++ let _ = a.unsigned_abs();
++ let _ = a.unsigned_abs() as u8;
++ let _ = a.unsigned_abs() as u16;
++ let _ = a.unsigned_abs() as u32;
++ let _ = a.unsigned_abs() as u64;
++ let _ = a.unsigned_abs() as u128;
+}
--- /dev/null
+// run-rustfix
+#![warn(clippy::cast_abs_to_unsigned)]
+
+fn main() {
+ let x: i32 = -42;
+ let y: u32 = x.abs() as u32;
+ println!("The absolute value of {} is {}", x, y);
++
++ let a: i32 = -3;
++ let _: usize = a.abs() as usize;
++ let _: usize = a.abs() as _;
++ let _ = a.abs() as usize;
++
++ let a: i64 = -3;
++ let _ = a.abs() as usize;
++ let _ = a.abs() as u8;
++ let _ = a.abs() as u16;
++ let _ = a.abs() as u32;
++ let _ = a.abs() as u64;
++ let _ = a.abs() as u128;
++
++ let a: isize = -3;
++ let _ = a.abs() as usize;
++ let _ = a.abs() as u8;
++ let _ = a.abs() as u16;
++ let _ = a.abs() as u32;
++ let _ = a.abs() as u64;
++ let _ = a.abs() as u128;
+}
--- /dev/null
- error: aborting due to previous error
+error: casting the result of `i32::abs()` to u32
+ --> $DIR/cast_abs_to_unsigned.rs:6:18
+ |
+LL | let y: u32 = x.abs() as u32;
+ | ^^^^^^^^^^^^^^ help: replace with: `x.unsigned_abs()`
+ |
+ = note: `-D clippy::cast-abs-to-unsigned` implied by `-D warnings`
+
++error: casting the result of `i32::abs()` to usize
++ --> $DIR/cast_abs_to_unsigned.rs:10:20
++ |
++LL | let _: usize = a.abs() as usize;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `i32::abs()` to usize
++ --> $DIR/cast_abs_to_unsigned.rs:11:20
++ |
++LL | let _: usize = a.abs() as _;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `i32::abs()` to usize
++ --> $DIR/cast_abs_to_unsigned.rs:12:13
++ |
++LL | let _ = a.abs() as usize;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `i64::abs()` to usize
++ --> $DIR/cast_abs_to_unsigned.rs:15:13
++ |
++LL | let _ = a.abs() as usize;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `i64::abs()` to u8
++ --> $DIR/cast_abs_to_unsigned.rs:16:13
++ |
++LL | let _ = a.abs() as u8;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `i64::abs()` to u16
++ --> $DIR/cast_abs_to_unsigned.rs:17:13
++ |
++LL | let _ = a.abs() as u16;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `i64::abs()` to u32
++ --> $DIR/cast_abs_to_unsigned.rs:18:13
++ |
++LL | let _ = a.abs() as u32;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `i64::abs()` to u64
++ --> $DIR/cast_abs_to_unsigned.rs:19:13
++ |
++LL | let _ = a.abs() as u64;
++ | ^^^^^^^^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `i64::abs()` to u128
++ --> $DIR/cast_abs_to_unsigned.rs:20:13
++ |
++LL | let _ = a.abs() as u128;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `isize::abs()` to usize
++ --> $DIR/cast_abs_to_unsigned.rs:23:13
++ |
++LL | let _ = a.abs() as usize;
++ | ^^^^^^^^^^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `isize::abs()` to u8
++ --> $DIR/cast_abs_to_unsigned.rs:24:13
++ |
++LL | let _ = a.abs() as u8;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `isize::abs()` to u16
++ --> $DIR/cast_abs_to_unsigned.rs:25:13
++ |
++LL | let _ = a.abs() as u16;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `isize::abs()` to u32
++ --> $DIR/cast_abs_to_unsigned.rs:26:13
++ |
++LL | let _ = a.abs() as u32;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `isize::abs()` to u64
++ --> $DIR/cast_abs_to_unsigned.rs:27:13
++ |
++LL | let _ = a.abs() as u64;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: casting the result of `isize::abs()` to u128
++ --> $DIR/cast_abs_to_unsigned.rs:28:13
++ |
++LL | let _ = a.abs() as u128;
++ | ^^^^^^^ help: replace with: `a.unsigned_abs()`
++
++error: aborting due to 16 previous errors
+
--- /dev/null
- Some(ref s) => match &*s {
+#![warn(clippy::collapsible_match)]
+#![allow(
+ clippy::needless_return,
+ clippy::no_effect,
+ clippy::single_match,
+ clippy::needless_borrow
+)]
+
+fn lint_cases(opt_opt: Option<Option<u32>>, res_opt: Result<Option<u32>, String>) {
+ // if guards on outer match
+ {
+ match res_opt {
+ Ok(val) if make() => match val {
+ Some(n) => foo(n),
+ _ => return,
+ },
+ _ => return,
+ }
+ match res_opt {
+ Ok(val) => match val {
+ Some(n) => foo(n),
+ _ => return,
+ },
+ _ if make() => return,
+ _ => return,
+ }
+ }
+
+ // macro
+ {
+ macro_rules! mac {
+ ($outer:expr => $pat:pat, $e:expr => $inner_pat:pat, $then:expr) => {
+ match $outer {
+ $pat => match $e {
+ $inner_pat => $then,
+ _ => return,
+ },
+ _ => return,
+ }
+ };
+ }
+ // Lint this since the patterns are not defined by the macro.
+ // Allows the lint to work on if_chain! for example.
+ // Fixing the lint requires knowledge of the specific macro, but we optimistically assume that
+ // there is still a better way to write this.
+ mac!(res_opt => Ok(val), val => Some(n), foo(n));
+ }
+
+ // deref reference value
+ match Some(&[1]) {
+ Some(s) => match *s {
+ [n] => foo(n),
+ _ => (),
+ },
+ _ => (),
+ }
+
+ // ref pattern and deref
+ match Some(&[1]) {
++ Some(ref s) => match s {
+ [n] => foo(n),
+ _ => (),
+ },
+ _ => (),
+ }
+}
+
+fn no_lint() {
+ // deref inner value (cannot pattern match with Vec)
+ match Some(vec![1]) {
+ Some(s) => match *s {
+ [n] => foo(n),
+ _ => (),
+ },
+ _ => (),
+ }
+}
+
+fn make<T>() -> T {
+ unimplemented!()
+}
+
+fn foo<T, U>(t: T) -> U {
+ unimplemented!()
+}
+
+fn main() {}
--- /dev/null
- LL | Some(ref s) => match &*s {
+error: this `match` can be collapsed into the outer `match`
+ --> $DIR/collapsible_match2.rs:13:34
+ |
+LL | Ok(val) if make() => match val {
+ | __________________________________^
+LL | | Some(n) => foo(n),
+LL | | _ => return,
+LL | | },
+ | |_____________^
+ |
+ = note: `-D clippy::collapsible-match` implied by `-D warnings`
+help: the outer pattern can be modified to include the inner pattern
+ --> $DIR/collapsible_match2.rs:13:16
+ |
+LL | Ok(val) if make() => match val {
+ | ^^^ replace this binding
+LL | Some(n) => foo(n),
+ | ^^^^^^^ with this pattern
+
+error: this `match` can be collapsed into the outer `match`
+ --> $DIR/collapsible_match2.rs:20:24
+ |
+LL | Ok(val) => match val {
+ | ________________________^
+LL | | Some(n) => foo(n),
+LL | | _ => return,
+LL | | },
+ | |_____________^
+ |
+help: the outer pattern can be modified to include the inner pattern
+ --> $DIR/collapsible_match2.rs:20:16
+ |
+LL | Ok(val) => match val {
+ | ^^^ replace this binding
+LL | Some(n) => foo(n),
+ | ^^^^^^^ with this pattern
+
+error: this `match` can be collapsed into the outer `match`
+ --> $DIR/collapsible_match2.rs:34:29
+ |
+LL | $pat => match $e {
+ | _____________________________^
+LL | | $inner_pat => $then,
+LL | | _ => return,
+LL | | },
+ | |_____________________^
+...
+LL | mac!(res_opt => Ok(val), val => Some(n), foo(n));
+ | ------------------------------------------------ in this macro invocation
+ |
+help: the outer pattern can be modified to include the inner pattern
+ --> $DIR/collapsible_match2.rs:46:28
+ |
+LL | mac!(res_opt => Ok(val), val => Some(n), foo(n));
+ | ^^^ ^^^^^^^ with this pattern
+ | |
+ | replace this binding
+ = note: this error originates in the macro `mac` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: this `match` can be collapsed into the outer `match`
+ --> $DIR/collapsible_match2.rs:51:20
+ |
+LL | Some(s) => match *s {
+ | ____________________^
+LL | | [n] => foo(n),
+LL | | _ => (),
+LL | | },
+ | |_________^
+ |
+help: the outer pattern can be modified to include the inner pattern
+ --> $DIR/collapsible_match2.rs:51:14
+ |
+LL | Some(s) => match *s {
+ | ^ replace this binding
+LL | [n] => foo(n),
+ | ^^^ with this pattern
+
+error: this `match` can be collapsed into the outer `match`
+ --> $DIR/collapsible_match2.rs:60:24
+ |
- LL | Some(ref s) => match &*s {
++LL | Some(ref s) => match s {
+ | ________________________^
+LL | | [n] => foo(n),
+LL | | _ => (),
+LL | | },
+ | |_________^
+ |
+help: the outer pattern can be modified to include the inner pattern
+ --> $DIR/collapsible_match2.rs:60:14
+ |
++LL | Some(ref s) => match s {
+ | ^^^^^ replace this binding
+LL | [n] => foo(n),
+ | ^^^ with this pattern
+
+error: aborting due to 5 previous errors
+
--- /dev/null
--- /dev/null
++fn fn_pointer_static() -> usize {
++ static FN: fn() -> usize = || 1;
++ let res = FN() + 1;
++ res
++}
++
++fn fn_pointer_const() -> usize {
++ const FN: fn() -> usize = || 1;
++ let res = FN() + 1;
++ res
++}
++
++fn deref_to_dyn_fn() -> usize {
++ struct Derefs;
++ impl std::ops::Deref for Derefs {
++ type Target = dyn Fn() -> usize;
++
++ fn deref(&self) -> &Self::Target {
++ &|| 2
++ }
++ }
++ static FN: Derefs = Derefs;
++ let res = FN() + 1;
++ res
++}
++
++fn main() {}
--- /dev/null
--- /dev/null
++error: returning the result of a `let` binding from a block
++ --> $DIR/ice-8850.rs:4:5
++ |
++LL | let res = FN() + 1;
++ | ------------------- unnecessary `let` binding
++LL | res
++ | ^^^
++ |
++ = note: `-D clippy::let-and-return` implied by `-D warnings`
++help: return the expression directly
++ |
++LL ~
++LL ~ FN() + 1
++ |
++
++error: returning the result of a `let` binding from a block
++ --> $DIR/ice-8850.rs:10:5
++ |
++LL | let res = FN() + 1;
++ | ------------------- unnecessary `let` binding
++LL | res
++ | ^^^
++ |
++help: return the expression directly
++ |
++LL ~
++LL ~ FN() + 1
++ |
++
++error: returning the result of a `let` binding from a block
++ --> $DIR/ice-8850.rs:24:5
++ |
++LL | let res = FN() + 1;
++ | ------------------- unnecessary `let` binding
++LL | res
++ | ^^^
++ |
++help: return the expression directly
++ |
++LL ~
++LL ~ FN() + 1
++ |
++
++error: aborting due to 3 previous errors
++
--- /dev/null
- error: aborting due to 10 previous errors
+error: `dbg!` macro is intended as a debugging tool
+ --> $DIR/dbg_macro.rs:5:22
+ |
+LL | if let Some(n) = dbg!(n.checked_sub(4)) { n } else { n }
+ | ^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: `-D clippy::dbg-macro` implied by `-D warnings`
+help: ensure to avoid having uses of it in version control
+ |
+LL | if let Some(n) = n.checked_sub(4) { n } else { n }
+ | ~~~~~~~~~~~~~~~~
+
+error: `dbg!` macro is intended as a debugging tool
+ --> $DIR/dbg_macro.rs:9:8
+ |
+LL | if dbg!(n <= 1) {
+ | ^^^^^^^^^^^^
+ |
+help: ensure to avoid having uses of it in version control
+ |
+LL | if n <= 1 {
+ | ~~~~~~
+
+error: `dbg!` macro is intended as a debugging tool
+ --> $DIR/dbg_macro.rs:10:9
+ |
+LL | dbg!(1)
+ | ^^^^^^^
+ |
+help: ensure to avoid having uses of it in version control
+ |
+LL | 1
+ |
+
+error: `dbg!` macro is intended as a debugging tool
+ --> $DIR/dbg_macro.rs:12:9
+ |
+LL | dbg!(n * factorial(n - 1))
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: ensure to avoid having uses of it in version control
+ |
+LL | n * factorial(n - 1)
+ |
+
+error: `dbg!` macro is intended as a debugging tool
+ --> $DIR/dbg_macro.rs:17:5
+ |
+LL | dbg!(42);
+ | ^^^^^^^^
+ |
+help: ensure to avoid having uses of it in version control
+ |
+LL | 42;
+ | ~~
+
+error: `dbg!` macro is intended as a debugging tool
+ --> $DIR/dbg_macro.rs:18:5
+ |
+LL | dbg!(dbg!(dbg!(42)));
+ | ^^^^^^^^^^^^^^^^^^^^
+ |
+help: ensure to avoid having uses of it in version control
+ |
+LL | dbg!(dbg!(42));
+ | ~~~~~~~~~~~~~~
+
+error: `dbg!` macro is intended as a debugging tool
+ --> $DIR/dbg_macro.rs:19:14
+ |
+LL | foo(3) + dbg!(factorial(4));
+ | ^^^^^^^^^^^^^^^^^^
+ |
+help: ensure to avoid having uses of it in version control
+ |
+LL | foo(3) + factorial(4);
+ | ~~~~~~~~~~~~
+
+error: `dbg!` macro is intended as a debugging tool
+ --> $DIR/dbg_macro.rs:20:5
+ |
+LL | dbg!(1, 2, dbg!(3, 4));
+ | ^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: ensure to avoid having uses of it in version control
+ |
+LL | (1, 2, dbg!(3, 4));
+ | ~~~~~~~~~~~~~~~~~~
+
+error: `dbg!` macro is intended as a debugging tool
+ --> $DIR/dbg_macro.rs:21:5
+ |
+LL | dbg!(1, 2, 3, 4, 5);
+ | ^^^^^^^^^^^^^^^^^^^
+ |
+help: ensure to avoid having uses of it in version control
+ |
+LL | (1, 2, 3, 4, 5);
+ | ~~~~~~~~~~~~~~~
+
+error: `dbg!` macro is intended as a debugging tool
+ --> $DIR/dbg_macro.rs:41:9
+ |
+LL | dbg!(2);
+ | ^^^^^^^
+ |
+help: ensure to avoid having uses of it in version control
+ |
+LL | 2;
+ | ~
+
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:47:5
++ |
++LL | dbg!(1);
++ | ^^^^^^^
++ |
++help: ensure to avoid having uses of it in version control
++ |
++LL | 1;
++ | ~
++
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:52:5
++ |
++LL | dbg!(1);
++ | ^^^^^^^
++ |
++help: ensure to avoid having uses of it in version control
++ |
++LL | 1;
++ | ~
++
++error: `dbg!` macro is intended as a debugging tool
++ --> $DIR/dbg_macro.rs:58:9
++ |
++LL | dbg!(1);
++ | ^^^^^^^
++ |
++help: ensure to avoid having uses of it in version control
++ |
++LL | 1;
++ | ~
++
++error: aborting due to 13 previous errors
+
--- /dev/null
- #![allow(clippy::redundant_closure_call)]
+#![feature(custom_inner_attributes)]
+#![rustfmt::skip]
+#![warn(clippy::debug_assert_with_mut_call)]
++#![allow(clippy::redundant_closure_call, clippy::get_first)]
+
+
+struct S;
+
+impl S {
+ fn bool_self_ref(&self) -> bool { false }
+ fn bool_self_mut(&mut self) -> bool { false }
+ fn bool_self_ref_arg_ref(&self, _: &u32) -> bool { false }
+ fn bool_self_ref_arg_mut(&self, _: &mut u32) -> bool { false }
+ fn bool_self_mut_arg_ref(&mut self, _: &u32) -> bool { false }
+ fn bool_self_mut_arg_mut(&mut self, _: &mut u32) -> bool { false }
+
+ fn u32_self_ref(&self) -> u32 { 0 }
+ fn u32_self_mut(&mut self) -> u32 { 0 }
+ fn u32_self_ref_arg_ref(&self, _: &u32) -> u32 { 0 }
+ fn u32_self_ref_arg_mut(&self, _: &mut u32) -> u32 { 0 }
+ fn u32_self_mut_arg_ref(&mut self, _: &u32) -> u32 { 0 }
+ fn u32_self_mut_arg_mut(&mut self, _: &mut u32) -> u32 { 0 }
+}
+
+fn bool_ref(_: &u32) -> bool { false }
+fn bool_mut(_: &mut u32) -> bool { false }
+fn u32_ref(_: &u32) -> u32 { 0 }
+fn u32_mut(_: &mut u32) -> u32 { 0 }
+
+fn func_non_mutable() {
+ debug_assert!(bool_ref(&3));
+ debug_assert!(!bool_ref(&3));
+
+ debug_assert_eq!(0, u32_ref(&3));
+ debug_assert_eq!(u32_ref(&3), 0);
+
+ debug_assert_ne!(1, u32_ref(&3));
+ debug_assert_ne!(u32_ref(&3), 1);
+}
+
+fn func_mutable() {
+ debug_assert!(bool_mut(&mut 3));
+ debug_assert!(!bool_mut(&mut 3));
+
+ debug_assert_eq!(0, u32_mut(&mut 3));
+ debug_assert_eq!(u32_mut(&mut 3), 0);
+
+ debug_assert_ne!(1, u32_mut(&mut 3));
+ debug_assert_ne!(u32_mut(&mut 3), 1);
+}
+
+fn method_non_mutable() {
+ debug_assert!(S.bool_self_ref());
+ debug_assert!(S.bool_self_ref_arg_ref(&3));
+
+ debug_assert_eq!(S.u32_self_ref(), 0);
+ debug_assert_eq!(S.u32_self_ref_arg_ref(&3), 0);
+
+ debug_assert_ne!(S.u32_self_ref(), 1);
+ debug_assert_ne!(S.u32_self_ref_arg_ref(&3), 1);
+}
+
+fn method_mutable() {
+ debug_assert!(S.bool_self_mut());
+ debug_assert!(!S.bool_self_mut());
+ debug_assert!(S.bool_self_ref_arg_mut(&mut 3));
+ debug_assert!(S.bool_self_mut_arg_ref(&3));
+ debug_assert!(S.bool_self_mut_arg_mut(&mut 3));
+
+ debug_assert_eq!(S.u32_self_mut(), 0);
+ debug_assert_eq!(S.u32_self_mut_arg_ref(&3), 0);
+ debug_assert_eq!(S.u32_self_ref_arg_mut(&mut 3), 0);
+ debug_assert_eq!(S.u32_self_mut_arg_mut(&mut 3), 0);
+
+ debug_assert_ne!(S.u32_self_mut(), 1);
+ debug_assert_ne!(S.u32_self_mut_arg_ref(&3), 1);
+ debug_assert_ne!(S.u32_self_ref_arg_mut(&mut 3), 1);
+ debug_assert_ne!(S.u32_self_mut_arg_mut(&mut 3), 1);
+}
+
+fn misc() {
+ // with variable
+ let mut v: Vec<u32> = vec![1, 2, 3, 4];
+ debug_assert_eq!(v.get(0), Some(&1));
+ debug_assert_ne!(v[0], 2);
+ debug_assert_eq!(v.pop(), Some(1));
+ debug_assert_ne!(Some(3), v.pop());
+
+ let a = &mut 3;
+ debug_assert!(bool_mut(a));
+
+ // nested
+ debug_assert!(!(bool_ref(&u32_mut(&mut 3))));
+
+ // chained
+ debug_assert_eq!(v.pop().unwrap(), 3);
+
+ // format args
+ debug_assert!(bool_ref(&3), "w/o format");
+ debug_assert!(bool_mut(&mut 3), "w/o format");
+ debug_assert!(bool_ref(&3), "{} format", "w/");
+ debug_assert!(bool_mut(&mut 3), "{} format", "w/");
+
+ // sub block
+ let mut x = 42_u32;
+ debug_assert!({
+ bool_mut(&mut x);
+ x > 10
+ });
+
+ // closures
+ debug_assert!((|| {
+ let mut x = 42;
+ bool_mut(&mut x);
+ x > 10
+ })());
+}
+
+async fn debug_await() {
+ debug_assert!(async {
+ true
+ }.await);
+}
+
+fn main() {
+ func_non_mutable();
+ func_mutable();
+ method_non_mutable();
+ method_mutable();
+
+ misc();
+ debug_await();
+}
--- /dev/null
+// run-rustfix
+
+#![warn(clippy::deref_by_slicing)]
++#![allow(clippy::borrow_deref_ref)]
+
+use std::io::Read;
+
+fn main() {
+ let mut vec = vec![0];
+ let _ = &*vec;
+ let _ = &mut *vec;
+
+ let ref_vec = &mut vec;
+ let _ = &**ref_vec;
+ let mut_slice = &mut **ref_vec;
+ let _ = &mut *mut_slice; // Err, re-borrows slice
+
+ let s = String::new();
+ let _ = &*s;
+
+ static S: &[u8] = &[0, 1, 2];
+ let _ = &mut &*S; // Err, re-borrows slice
+
+ let slice: &[u32] = &[0u32, 1u32];
+ let slice_ref = &slice;
+ let _ = *slice_ref; // Err, derefs slice
+
+ let bytes: &[u8] = &[];
+ let _ = (&*bytes).read_to_end(&mut vec![]).unwrap(); // Err, re-borrows slice
+}
--- /dev/null
+// run-rustfix
+
+#![warn(clippy::deref_by_slicing)]
++#![allow(clippy::borrow_deref_ref)]
+
+use std::io::Read;
+
+fn main() {
+ let mut vec = vec![0];
+ let _ = &vec[..];
+ let _ = &mut vec[..];
+
+ let ref_vec = &mut vec;
+ let _ = &ref_vec[..];
+ let mut_slice = &mut ref_vec[..];
+ let _ = &mut mut_slice[..]; // Err, re-borrows slice
+
+ let s = String::new();
+ let _ = &s[..];
+
+ static S: &[u8] = &[0, 1, 2];
+ let _ = &mut &S[..]; // Err, re-borrows slice
+
+ let slice: &[u32] = &[0u32, 1u32];
+ let slice_ref = &slice;
+ let _ = &slice_ref[..]; // Err, derefs slice
+
+ let bytes: &[u8] = &[];
+ let _ = (&bytes[..]).read_to_end(&mut vec![]).unwrap(); // Err, re-borrows slice
+}
--- /dev/null
- --> $DIR/deref_by_slicing.rs:9:13
+error: slicing when dereferencing would work
- --> $DIR/deref_by_slicing.rs:10:13
++ --> $DIR/deref_by_slicing.rs:10:13
+ |
+LL | let _ = &vec[..];
+ | ^^^^^^^^ help: dereference the original value instead: `&*vec`
+ |
+ = note: `-D clippy::deref-by-slicing` implied by `-D warnings`
+
+error: slicing when dereferencing would work
- --> $DIR/deref_by_slicing.rs:13:13
++ --> $DIR/deref_by_slicing.rs:11:13
+ |
+LL | let _ = &mut vec[..];
+ | ^^^^^^^^^^^^ help: dereference the original value instead: `&mut *vec`
+
+error: slicing when dereferencing would work
- --> $DIR/deref_by_slicing.rs:14:21
++ --> $DIR/deref_by_slicing.rs:14:13
+ |
+LL | let _ = &ref_vec[..];
+ | ^^^^^^^^^^^^ help: dereference the original value instead: `&**ref_vec`
+
+error: slicing when dereferencing would work
- --> $DIR/deref_by_slicing.rs:15:13
++ --> $DIR/deref_by_slicing.rs:15:21
+ |
+LL | let mut_slice = &mut ref_vec[..];
+ | ^^^^^^^^^^^^^^^^ help: dereference the original value instead: `&mut **ref_vec`
+
+error: slicing when dereferencing would work
- --> $DIR/deref_by_slicing.rs:18:13
++ --> $DIR/deref_by_slicing.rs:16:13
+ |
+LL | let _ = &mut mut_slice[..]; // Err, re-borrows slice
+ | ^^^^^^^^^^^^^^^^^^ help: reborrow the original value instead: `&mut *mut_slice`
+
+error: slicing when dereferencing would work
- --> $DIR/deref_by_slicing.rs:21:18
++ --> $DIR/deref_by_slicing.rs:19:13
+ |
+LL | let _ = &s[..];
+ | ^^^^^^ help: dereference the original value instead: `&*s`
+
+error: slicing when dereferencing would work
- --> $DIR/deref_by_slicing.rs:25:13
++ --> $DIR/deref_by_slicing.rs:22:18
+ |
+LL | let _ = &mut &S[..]; // Err, re-borrows slice
+ | ^^^^^^ help: reborrow the original value instead: `&*S`
+
+error: slicing when dereferencing would work
- --> $DIR/deref_by_slicing.rs:28:13
++ --> $DIR/deref_by_slicing.rs:26:13
+ |
+LL | let _ = &slice_ref[..]; // Err, derefs slice
+ | ^^^^^^^^^^^^^^ help: dereference the original value instead: `*slice_ref`
+
+error: slicing when dereferencing would work
++ --> $DIR/deref_by_slicing.rs:29:13
+ |
+LL | let _ = (&bytes[..]).read_to_end(&mut vec![]).unwrap(); // Err, re-borrows slice
+ | ^^^^^^^^^^^^ help: reborrow the original value instead: `(&*bytes)`
+
+error: aborting due to 9 previous errors
+
--- /dev/null
+// run-rustfix
+
+#![allow(unused)]
+#![warn(clippy::derive_partial_eq_without_eq)]
+
+// Don't warn on structs that aren't PartialEq
+struct NotPartialEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq can be derived but is missing
+#[derive(Debug, PartialEq, Eq)]
+struct MissingEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq is derived
+#[derive(PartialEq, Eq)]
+struct NotMissingEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq is manually implemented
+#[derive(PartialEq)]
+struct ManualEqImpl {
+ foo: u32,
+ bar: String,
+}
+
+impl Eq for ManualEqImpl {}
+
+// Cannot be Eq because f32 isn't Eq
+#[derive(PartialEq)]
+struct CannotBeEq {
+ foo: u32,
+ bar: f32,
+}
+
+// Don't warn if PartialEq is manually implemented
+struct ManualPartialEqImpl {
+ foo: u32,
+ bar: String,
+}
+
+impl PartialEq for ManualPartialEqImpl {
+ fn eq(&self, other: &Self) -> bool {
+ self.foo == other.foo && self.bar == other.bar
+ }
+}
+
+// Generic fields should be properly checked for Eq-ness
+#[derive(PartialEq)]
+struct GenericNotEq<T: Eq, U: PartialEq> {
+ foo: T,
+ bar: U,
+}
+
+#[derive(PartialEq, Eq)]
+struct GenericEq<T: Eq, U: Eq> {
+ foo: T,
+ bar: U,
+}
+
+#[derive(PartialEq, Eq)]
+struct TupleStruct(u32);
+
+#[derive(PartialEq, Eq)]
+struct GenericTupleStruct<T: Eq>(T);
+
+#[derive(PartialEq)]
+struct TupleStructNotEq(f32);
+
+#[derive(PartialEq, Eq)]
+enum Enum {
+ Foo(u32),
+ Bar { a: String, b: () },
+}
+
+#[derive(PartialEq, Eq)]
+enum GenericEnum<T: Eq, U: Eq, V: Eq> {
+ Foo(T),
+ Bar { a: U, b: V },
+}
+
+#[derive(PartialEq)]
+enum EnumNotEq {
+ Foo(u32),
+ Bar { a: String, b: f32 },
+}
+
+// Ensure that rustfix works properly when `PartialEq` has other derives on either side
+#[derive(Debug, PartialEq, Eq, Clone)]
+struct RustFixWithOtherDerives;
+
++#[derive(PartialEq)]
++struct Generic<T>(T);
++
++#[derive(PartialEq, Eq)]
++struct GenericPhantom<T>(core::marker::PhantomData<T>);
++
+fn main() {}
--- /dev/null
+// run-rustfix
+
+#![allow(unused)]
+#![warn(clippy::derive_partial_eq_without_eq)]
+
+// Don't warn on structs that aren't PartialEq
+struct NotPartialEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq can be derived but is missing
+#[derive(Debug, PartialEq)]
+struct MissingEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq is derived
+#[derive(PartialEq, Eq)]
+struct NotMissingEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq is manually implemented
+#[derive(PartialEq)]
+struct ManualEqImpl {
+ foo: u32,
+ bar: String,
+}
+
+impl Eq for ManualEqImpl {}
+
+// Cannot be Eq because f32 isn't Eq
+#[derive(PartialEq)]
+struct CannotBeEq {
+ foo: u32,
+ bar: f32,
+}
+
+// Don't warn if PartialEq is manually implemented
+struct ManualPartialEqImpl {
+ foo: u32,
+ bar: String,
+}
+
+impl PartialEq for ManualPartialEqImpl {
+ fn eq(&self, other: &Self) -> bool {
+ self.foo == other.foo && self.bar == other.bar
+ }
+}
+
+// Generic fields should be properly checked for Eq-ness
+#[derive(PartialEq)]
+struct GenericNotEq<T: Eq, U: PartialEq> {
+ foo: T,
+ bar: U,
+}
+
+#[derive(PartialEq)]
+struct GenericEq<T: Eq, U: Eq> {
+ foo: T,
+ bar: U,
+}
+
+#[derive(PartialEq)]
+struct TupleStruct(u32);
+
+#[derive(PartialEq)]
+struct GenericTupleStruct<T: Eq>(T);
+
+#[derive(PartialEq)]
+struct TupleStructNotEq(f32);
+
+#[derive(PartialEq)]
+enum Enum {
+ Foo(u32),
+ Bar { a: String, b: () },
+}
+
+#[derive(PartialEq)]
+enum GenericEnum<T: Eq, U: Eq, V: Eq> {
+ Foo(T),
+ Bar { a: U, b: V },
+}
+
+#[derive(PartialEq)]
+enum EnumNotEq {
+ Foo(u32),
+ Bar { a: String, b: f32 },
+}
+
+// Ensure that rustfix works properly when `PartialEq` has other derives on either side
+#[derive(Debug, PartialEq, Clone)]
+struct RustFixWithOtherDerives;
+
++#[derive(PartialEq)]
++struct Generic<T>(T);
++
++#[derive(PartialEq, Eq)]
++struct GenericPhantom<T>(core::marker::PhantomData<T>);
++
+fn main() {}
--- /dev/null
--- /dev/null
++#![warn(clippy::doc_link_with_quotes)]
++
++fn main() {
++ foo()
++}
++
++/// Calls ['bar']
++pub fn foo() {
++ bar()
++}
++
++pub fn bar() {}
--- /dev/null
--- /dev/null
++error: possible intra-doc link using quotes instead of backticks
++ --> $DIR/doc_link_with_quotes.rs:7:1
++ |
++LL | /// Calls ['bar']
++ | ^^^^^^^^^^^^^^^^^
++ |
++ = note: `-D clippy::doc-link-with-quotes` implied by `-D warnings`
++
++error: aborting due to previous error
++
--- /dev/null
+// aux-build:proc_macro_attr.rs
+#![warn(clippy::empty_line_after_outer_attr)]
+#![allow(clippy::assertions_on_constants)]
+#![feature(custom_inner_attributes)]
+#![rustfmt::skip]
+
++#[macro_use]
++extern crate clap;
++
+#[macro_use]
+extern crate proc_macro_attr;
+
+// This should produce a warning
+#[crate_type = "lib"]
+
+/// some comment
+fn with_one_newline_and_comment() { assert!(true) }
+
+// This should not produce a warning
+#[crate_type = "lib"]
+/// some comment
+fn with_no_newline_and_comment() { assert!(true) }
+
+
+// This should produce a warning
+#[crate_type = "lib"]
+
+fn with_one_newline() { assert!(true) }
+
+// This should produce a warning, too
+#[crate_type = "lib"]
+
+
+fn with_two_newlines() { assert!(true) }
+
+
+// This should produce a warning
+#[crate_type = "lib"]
+
+enum Baz {
+ One,
+ Two
+}
+
+// This should produce a warning
+#[crate_type = "lib"]
+
+struct Foo {
+ one: isize,
+ two: isize
+}
+
+// This should produce a warning
+#[crate_type = "lib"]
+
+mod foo {
+}
+
+/// This doc comment should not produce a warning
+
+/** This is also a doc comment and should not produce a warning
+ */
+
+// This should not produce a warning
+#[allow(non_camel_case_types)]
+#[allow(missing_docs)]
+#[allow(missing_docs)]
+fn three_attributes() { assert!(true) }
+
+// This should not produce a warning
+#[doc = "
+Returns the escaped value of the textual representation of
+
+"]
+pub fn function() -> bool {
+ true
+}
+
+// This should not produce a warning
+#[derive(Clone, Copy)]
+pub enum FooFighter {
+ Bar1,
+
+ Bar2,
+
+ Bar3,
+
+ Bar4
+}
+
+// This should not produce a warning because the empty line is inside a block comment
+#[crate_type = "lib"]
+/*
+
+*/
+pub struct S;
+
+// This should not produce a warning
+#[crate_type = "lib"]
+/* test */
+pub struct T;
+
+// This should not produce a warning
+// See https://github.com/rust-lang/rust-clippy/issues/5567
+#[fake_async_trait]
+pub trait Bazz {
+ fn foo() -> Vec<u8> {
+ let _i = "";
+
+
+
+ vec![]
+ }
+}
+
++#[derive(clap::Parser)]
++#[clap(after_help = "This ia a help message.
++
++You're welcome.
++")]
++pub struct Args;
++
+fn main() {}
--- /dev/null
- --> $DIR/empty_line_after_outer_attribute.rs:11:1
+error: found an empty line after an outer attribute. Perhaps you forgot to add a `!` to make it an inner attribute?
- --> $DIR/empty_line_after_outer_attribute.rs:23:1
++ --> $DIR/empty_line_after_outer_attribute.rs:14:1
+ |
+LL | / #[crate_type = "lib"]
+LL | |
+LL | | /// some comment
+LL | | fn with_one_newline_and_comment() { assert!(true) }
+ | |_
+ |
+ = note: `-D clippy::empty-line-after-outer-attr` implied by `-D warnings`
+
+error: found an empty line after an outer attribute. Perhaps you forgot to add a `!` to make it an inner attribute?
- --> $DIR/empty_line_after_outer_attribute.rs:28:1
++ --> $DIR/empty_line_after_outer_attribute.rs:26:1
+ |
+LL | / #[crate_type = "lib"]
+LL | |
+LL | | fn with_one_newline() { assert!(true) }
+ | |_
+
+error: found an empty line after an outer attribute. Perhaps you forgot to add a `!` to make it an inner attribute?
- --> $DIR/empty_line_after_outer_attribute.rs:35:1
++ --> $DIR/empty_line_after_outer_attribute.rs:31:1
+ |
+LL | / #[crate_type = "lib"]
+LL | |
+LL | |
+LL | | fn with_two_newlines() { assert!(true) }
+ | |_
+
+error: found an empty line after an outer attribute. Perhaps you forgot to add a `!` to make it an inner attribute?
- --> $DIR/empty_line_after_outer_attribute.rs:43:1
++ --> $DIR/empty_line_after_outer_attribute.rs:38:1
+ |
+LL | / #[crate_type = "lib"]
+LL | |
+LL | | enum Baz {
+ | |_
+
+error: found an empty line after an outer attribute. Perhaps you forgot to add a `!` to make it an inner attribute?
- --> $DIR/empty_line_after_outer_attribute.rs:51:1
++ --> $DIR/empty_line_after_outer_attribute.rs:46:1
+ |
+LL | / #[crate_type = "lib"]
+LL | |
+LL | | struct Foo {
+ | |_
+
+error: found an empty line after an outer attribute. Perhaps you forgot to add a `!` to make it an inner attribute?
++ --> $DIR/empty_line_after_outer_attribute.rs:54:1
+ |
+LL | / #[crate_type = "lib"]
+LL | |
+LL | | mod foo {
+ | |_
+
+error: aborting due to 6 previous errors
+
--- /dev/null
- #![allow(unused_variables, clippy::clone_double_ref, clippy::needless_borrow)]
+// run-rustfix
+
++#![allow(
++ unused_variables,
++ clippy::clone_double_ref,
++ clippy::needless_borrow,
++ clippy::borrow_deref_ref
++)]
+#![warn(clippy::explicit_deref_methods)]
+
+use std::ops::{Deref, DerefMut};
+
+fn concat(deref_str: &str) -> String {
+ format!("{}bar", deref_str)
+}
+
+fn just_return(deref_str: &str) -> &str {
+ deref_str
+}
+
+struct CustomVec(Vec<u8>);
+impl Deref for CustomVec {
+ type Target = Vec<u8>;
+
+ fn deref(&self) -> &Vec<u8> {
+ &self.0
+ }
+}
+
+fn main() {
+ let a: &mut String = &mut String::from("foo");
+
+ // these should require linting
+
+ let b: &str = &*a;
+
+ let b: &mut str = &mut **a;
+
+ // both derefs should get linted here
+ let b: String = format!("{}, {}", &*a, &*a);
+
+ println!("{}", &*a);
+
+ #[allow(clippy::match_single_binding)]
+ match &*a {
+ _ => (),
+ }
+
+ let b: String = concat(&*a);
+
+ let b = just_return(a);
+
+ let b: String = concat(just_return(a));
+
+ let b: &str = &**a;
+
+ let opt_a = Some(a.clone());
+ let b = &*opt_a.unwrap();
+
+ // following should not require linting
+
+ let cv = CustomVec(vec![0, 42]);
+ let c = cv.deref()[0];
+
+ let b: &str = &*a.deref();
+
+ let b: String = a.deref().clone();
+
+ let b: usize = a.deref_mut().len();
+
+ let b: &usize = &a.deref().len();
+
+ let b: &str = &*a;
+
+ let b: &mut str = &mut *a;
+
+ macro_rules! expr_deref {
+ ($body:expr) => {
+ $body.deref()
+ };
+ }
+ let b: &str = expr_deref!(a);
+
+ let b: &str = expr_deref!(&*a);
+
+ // The struct does not implement Deref trait
+ #[derive(Copy, Clone)]
+ struct NoLint(u32);
+ impl NoLint {
+ pub fn deref(self) -> u32 {
+ self.0
+ }
+ pub fn deref_mut(self) -> u32 {
+ self.0
+ }
+ }
+ let no_lint = NoLint(42);
+ let b = no_lint.deref();
+ let b = no_lint.deref_mut();
+}
--- /dev/null
- #![allow(unused_variables, clippy::clone_double_ref, clippy::needless_borrow)]
+// run-rustfix
+
++#![allow(
++ unused_variables,
++ clippy::clone_double_ref,
++ clippy::needless_borrow,
++ clippy::borrow_deref_ref
++)]
+#![warn(clippy::explicit_deref_methods)]
+
+use std::ops::{Deref, DerefMut};
+
+fn concat(deref_str: &str) -> String {
+ format!("{}bar", deref_str)
+}
+
+fn just_return(deref_str: &str) -> &str {
+ deref_str
+}
+
+struct CustomVec(Vec<u8>);
+impl Deref for CustomVec {
+ type Target = Vec<u8>;
+
+ fn deref(&self) -> &Vec<u8> {
+ &self.0
+ }
+}
+
+fn main() {
+ let a: &mut String = &mut String::from("foo");
+
+ // these should require linting
+
+ let b: &str = a.deref();
+
+ let b: &mut str = a.deref_mut();
+
+ // both derefs should get linted here
+ let b: String = format!("{}, {}", a.deref(), a.deref());
+
+ println!("{}", a.deref());
+
+ #[allow(clippy::match_single_binding)]
+ match a.deref() {
+ _ => (),
+ }
+
+ let b: String = concat(a.deref());
+
+ let b = just_return(a).deref();
+
+ let b: String = concat(just_return(a).deref());
+
+ let b: &str = a.deref().deref();
+
+ let opt_a = Some(a.clone());
+ let b = opt_a.unwrap().deref();
+
+ // following should not require linting
+
+ let cv = CustomVec(vec![0, 42]);
+ let c = cv.deref()[0];
+
+ let b: &str = &*a.deref();
+
+ let b: String = a.deref().clone();
+
+ let b: usize = a.deref_mut().len();
+
+ let b: &usize = &a.deref().len();
+
+ let b: &str = &*a;
+
+ let b: &mut str = &mut *a;
+
+ macro_rules! expr_deref {
+ ($body:expr) => {
+ $body.deref()
+ };
+ }
+ let b: &str = expr_deref!(a);
+
+ let b: &str = expr_deref!(a.deref());
+
+ // The struct does not implement Deref trait
+ #[derive(Copy, Clone)]
+ struct NoLint(u32);
+ impl NoLint {
+ pub fn deref(self) -> u32 {
+ self.0
+ }
+ pub fn deref_mut(self) -> u32 {
+ self.0
+ }
+ }
+ let no_lint = NoLint(42);
+ let b = no_lint.deref();
+ let b = no_lint.deref_mut();
+}
--- /dev/null
- --> $DIR/explicit_deref_methods.rs:30:19
+error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:32:23
++ --> $DIR/explicit_deref_methods.rs:35:19
+ |
+LL | let b: &str = a.deref();
+ | ^^^^^^^^^ help: try this: `&*a`
+ |
+ = note: `-D clippy::explicit-deref-methods` implied by `-D warnings`
+
+error: explicit `deref_mut` method call
- --> $DIR/explicit_deref_methods.rs:35:39
++ --> $DIR/explicit_deref_methods.rs:37:23
+ |
+LL | let b: &mut str = a.deref_mut();
+ | ^^^^^^^^^^^^^ help: try this: `&mut **a`
+
+error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:35:50
++ --> $DIR/explicit_deref_methods.rs:40:39
+ |
+LL | let b: String = format!("{}, {}", a.deref(), a.deref());
+ | ^^^^^^^^^ help: try this: `&*a`
+
+error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:37:20
++ --> $DIR/explicit_deref_methods.rs:40:50
+ |
+LL | let b: String = format!("{}, {}", a.deref(), a.deref());
+ | ^^^^^^^^^ help: try this: `&*a`
+
+error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:40:11
++ --> $DIR/explicit_deref_methods.rs:42:20
+ |
+LL | println!("{}", a.deref());
+ | ^^^^^^^^^ help: try this: `&*a`
+
+error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:44:28
++ --> $DIR/explicit_deref_methods.rs:45:11
+ |
+LL | match a.deref() {
+ | ^^^^^^^^^ help: try this: `&*a`
+
+error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:46:13
++ --> $DIR/explicit_deref_methods.rs:49:28
+ |
+LL | let b: String = concat(a.deref());
+ | ^^^^^^^^^ help: try this: `&*a`
+
+error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:48:28
++ --> $DIR/explicit_deref_methods.rs:51:13
+ |
+LL | let b = just_return(a).deref();
+ | ^^^^^^^^^^^^^^^^^^^^^^ help: try this: `just_return(a)`
+
+error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:50:19
++ --> $DIR/explicit_deref_methods.rs:53:28
+ |
+LL | let b: String = concat(just_return(a).deref());
+ | ^^^^^^^^^^^^^^^^^^^^^^ help: try this: `just_return(a)`
+
+error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:53:13
++ --> $DIR/explicit_deref_methods.rs:55:19
+ |
+LL | let b: &str = a.deref().deref();
+ | ^^^^^^^^^^^^^^^^^ help: try this: `&**a`
+
+error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:79:31
++ --> $DIR/explicit_deref_methods.rs:58:13
+ |
+LL | let b = opt_a.unwrap().deref();
+ | ^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&*opt_a.unwrap()`
+
+error: explicit `deref` method call
++ --> $DIR/explicit_deref_methods.rs:84:31
+ |
+LL | let b: &str = expr_deref!(a.deref());
+ | ^^^^^^^^^ help: try this: `&*a`
+
+error: aborting due to 12 previous errors
+
--- /dev/null
+#![warn(clippy::forget_ref)]
+#![allow(clippy::toplevel_ref_arg)]
+#![allow(clippy::unnecessary_wraps, clippy::forget_non_drop)]
++#![allow(clippy::borrow_deref_ref)]
+
+use std::mem::forget;
+
+struct SomeStruct;
+
+fn main() {
+ forget(&SomeStruct);
+
+ let mut owned = SomeStruct;
+ forget(&owned);
+ forget(&&owned);
+ forget(&mut owned);
+ forget(owned); //OK
+
+ let reference1 = &SomeStruct;
+ forget(&*reference1);
+
+ let reference2 = &mut SomeStruct;
+ forget(reference2);
+
+ let ref reference3 = SomeStruct;
+ forget(reference3);
+}
+
+#[allow(dead_code)]
+fn test_generic_fn_forget<T>(val: T) {
+ forget(&val);
+ forget(val); //OK
+}
+
+#[allow(dead_code)]
+fn test_similarly_named_function() {
+ fn forget<T>(_val: T) {}
+ forget(&SomeStruct); //OK; call to unrelated function which happens to have the same name
+ std::mem::forget(&SomeStruct);
+}
+
+#[derive(Copy, Clone)]
+pub struct Error;
+fn produce_half_owl_error() -> Result<(), Error> {
+ Ok(())
+}
+
+fn produce_half_owl_ok() -> Result<bool, ()> {
+ Ok(true)
+}
--- /dev/null
- --> $DIR/forget_ref.rs:10:5
+error: calls to `std::mem::forget` with a reference instead of an owned value. Forgetting a reference does nothing
- --> $DIR/forget_ref.rs:10:12
++ --> $DIR/forget_ref.rs:11:5
+ |
+LL | forget(&SomeStruct);
+ | ^^^^^^^^^^^^^^^^^^^
+ |
+ = note: `-D clippy::forget-ref` implied by `-D warnings`
+note: argument has type `&SomeStruct`
- --> $DIR/forget_ref.rs:13:5
++ --> $DIR/forget_ref.rs:11:12
+ |
+LL | forget(&SomeStruct);
+ | ^^^^^^^^^^^
+
+error: calls to `std::mem::forget` with a reference instead of an owned value. Forgetting a reference does nothing
- --> $DIR/forget_ref.rs:13:12
++ --> $DIR/forget_ref.rs:14:5
+ |
+LL | forget(&owned);
+ | ^^^^^^^^^^^^^^
+ |
+note: argument has type `&SomeStruct`
- --> $DIR/forget_ref.rs:14:5
++ --> $DIR/forget_ref.rs:14:12
+ |
+LL | forget(&owned);
+ | ^^^^^^
+
+error: calls to `std::mem::forget` with a reference instead of an owned value. Forgetting a reference does nothing
- --> $DIR/forget_ref.rs:14:12
++ --> $DIR/forget_ref.rs:15:5
+ |
+LL | forget(&&owned);
+ | ^^^^^^^^^^^^^^^
+ |
+note: argument has type `&&SomeStruct`
- --> $DIR/forget_ref.rs:15:5
++ --> $DIR/forget_ref.rs:15:12
+ |
+LL | forget(&&owned);
+ | ^^^^^^^
+
+error: calls to `std::mem::forget` with a reference instead of an owned value. Forgetting a reference does nothing
- --> $DIR/forget_ref.rs:15:12
++ --> $DIR/forget_ref.rs:16:5
+ |
+LL | forget(&mut owned);
+ | ^^^^^^^^^^^^^^^^^^
+ |
+note: argument has type `&mut SomeStruct`
- --> $DIR/forget_ref.rs:19:5
++ --> $DIR/forget_ref.rs:16:12
+ |
+LL | forget(&mut owned);
+ | ^^^^^^^^^^
+
+error: calls to `std::mem::forget` with a reference instead of an owned value. Forgetting a reference does nothing
- --> $DIR/forget_ref.rs:19:12
++ --> $DIR/forget_ref.rs:20:5
+ |
+LL | forget(&*reference1);
+ | ^^^^^^^^^^^^^^^^^^^^
+ |
+note: argument has type `&SomeStruct`
- --> $DIR/forget_ref.rs:22:5
++ --> $DIR/forget_ref.rs:20:12
+ |
+LL | forget(&*reference1);
+ | ^^^^^^^^^^^^
+
+error: calls to `std::mem::forget` with a reference instead of an owned value. Forgetting a reference does nothing
- --> $DIR/forget_ref.rs:22:12
++ --> $DIR/forget_ref.rs:23:5
+ |
+LL | forget(reference2);
+ | ^^^^^^^^^^^^^^^^^^
+ |
+note: argument has type `&mut SomeStruct`
- --> $DIR/forget_ref.rs:25:5
++ --> $DIR/forget_ref.rs:23:12
+ |
+LL | forget(reference2);
+ | ^^^^^^^^^^
+
+error: calls to `std::mem::forget` with a reference instead of an owned value. Forgetting a reference does nothing
- --> $DIR/forget_ref.rs:25:12
++ --> $DIR/forget_ref.rs:26:5
+ |
+LL | forget(reference3);
+ | ^^^^^^^^^^^^^^^^^^
+ |
+note: argument has type `&SomeStruct`
- --> $DIR/forget_ref.rs:30:5
++ --> $DIR/forget_ref.rs:26:12
+ |
+LL | forget(reference3);
+ | ^^^^^^^^^^
+
+error: calls to `std::mem::forget` with a reference instead of an owned value. Forgetting a reference does nothing
- --> $DIR/forget_ref.rs:30:12
++ --> $DIR/forget_ref.rs:31:5
+ |
+LL | forget(&val);
+ | ^^^^^^^^^^^^
+ |
+note: argument has type `&T`
- --> $DIR/forget_ref.rs:38:5
++ --> $DIR/forget_ref.rs:31:12
+ |
+LL | forget(&val);
+ | ^^^^
+
+error: calls to `std::mem::forget` with a reference instead of an owned value. Forgetting a reference does nothing
- --> $DIR/forget_ref.rs:38:22
++ --> $DIR/forget_ref.rs:39:5
+ |
+LL | std::mem::forget(&SomeStruct);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+note: argument has type `&SomeStruct`
++ --> $DIR/forget_ref.rs:39:22
+ |
+LL | std::mem::forget(&SomeStruct);
+ | ^^^^^^^^^^^
+
+error: aborting due to 9 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::get_first)]
++use std::collections::BTreeMap;
++use std::collections::HashMap;
++use std::collections::VecDeque;
++
++struct Bar {
++ arr: [u32; 3],
++}
++
++impl Bar {
++ fn get(&self, pos: usize) -> Option<&u32> {
++ self.arr.get(pos)
++ }
++}
++
++fn main() {
++ let x = vec![2, 3, 5];
++ let _ = x.first(); // Use x.first()
++ let _ = x.get(1);
++ let _ = x[0];
++
++ let y = [2, 3, 5];
++ let _ = y.first(); // Use y.first()
++ let _ = y.get(1);
++ let _ = y[0];
++
++ let z = &[2, 3, 5];
++ let _ = z.first(); // Use z.first()
++ let _ = z.get(1);
++ let _ = z[0];
++
++ let vecdeque: VecDeque<_> = x.iter().cloned().collect();
++ let hashmap: HashMap<u8, char> = HashMap::from_iter(vec![(0, 'a'), (1, 'b')]);
++ let btreemap: BTreeMap<u8, char> = BTreeMap::from_iter(vec![(0, 'a'), (1, 'b')]);
++ let _ = vecdeque.get(0); // Do not lint, because VecDeque is not slice.
++ let _ = hashmap.get(&0); // Do not lint, because HashMap is not slice.
++ let _ = btreemap.get(&0); // Do not lint, because BTreeMap is not slice.
++
++ let bar = Bar { arr: [0, 1, 2] };
++ let _ = bar.get(0); // Do not lint, because Bar is struct.
++}
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::get_first)]
++use std::collections::BTreeMap;
++use std::collections::HashMap;
++use std::collections::VecDeque;
++
++struct Bar {
++ arr: [u32; 3],
++}
++
++impl Bar {
++ fn get(&self, pos: usize) -> Option<&u32> {
++ self.arr.get(pos)
++ }
++}
++
++fn main() {
++ let x = vec![2, 3, 5];
++ let _ = x.get(0); // Use x.first()
++ let _ = x.get(1);
++ let _ = x[0];
++
++ let y = [2, 3, 5];
++ let _ = y.get(0); // Use y.first()
++ let _ = y.get(1);
++ let _ = y[0];
++
++ let z = &[2, 3, 5];
++ let _ = z.get(0); // Use z.first()
++ let _ = z.get(1);
++ let _ = z[0];
++
++ let vecdeque: VecDeque<_> = x.iter().cloned().collect();
++ let hashmap: HashMap<u8, char> = HashMap::from_iter(vec![(0, 'a'), (1, 'b')]);
++ let btreemap: BTreeMap<u8, char> = BTreeMap::from_iter(vec![(0, 'a'), (1, 'b')]);
++ let _ = vecdeque.get(0); // Do not lint, because VecDeque is not slice.
++ let _ = hashmap.get(&0); // Do not lint, because HashMap is not slice.
++ let _ = btreemap.get(&0); // Do not lint, because BTreeMap is not slice.
++
++ let bar = Bar { arr: [0, 1, 2] };
++ let _ = bar.get(0); // Do not lint, because Bar is struct.
++}
--- /dev/null
--- /dev/null
++error: accessing first element with `x.get(0)`
++ --> $DIR/get_first.rs:19:13
++ |
++LL | let _ = x.get(0); // Use x.first()
++ | ^^^^^^^^ help: try: `x.first()`
++ |
++ = note: `-D clippy::get-first` implied by `-D warnings`
++
++error: accessing first element with `y.get(0)`
++ --> $DIR/get_first.rs:24:13
++ |
++LL | let _ = y.get(0); // Use y.first()
++ | ^^^^^^^^ help: try: `y.first()`
++
++error: accessing first element with `z.get(0)`
++ --> $DIR/get_first.rs:29:13
++ |
++LL | let _ = z.get(0); // Use z.first()
++ | ^^^^^^^^ help: try: `z.first()`
++
++error: aborting due to 3 previous errors
++
--- /dev/null
- let _ = x.last(); // ~ERROR Use x.last()
+// run-rustfix
+
+#![warn(clippy::get_last_with_len)]
++#![allow(unused)]
++
++use std::collections::VecDeque;
+
+fn dont_use_last() {
+ let x = vec![2, 3, 5];
- dont_use_last();
- indexing_two_from_end();
- index_into_last();
- use_last_with_different_vec_length();
++ let _ = x.last();
+}
+
+fn indexing_two_from_end() {
+ let x = vec![2, 3, 5];
+ let _ = x.get(x.len() - 2);
+}
+
+fn index_into_last() {
+ let x = vec![2, 3, 5];
+ let _ = x[x.len() - 1];
+}
+
+fn use_last_with_different_vec_length() {
+ let x = vec![2, 3, 5];
+ let y = vec!['a', 'b', 'c'];
+ let _ = x.get(y.len() - 1);
+}
+
++struct S {
++ field: Vec<usize>,
++}
++
++fn in_field(s: &S) {
++ let _ = s.field.last();
++}
++
+fn main() {
++ let slice = &[1, 2, 3];
++ let _ = slice.last();
++
++ let array = [4, 5, 6];
++ let _ = array.last();
++
++ let deq = VecDeque::from([7, 8, 9]);
++ let _ = deq.back();
++
++ let nested = [[1]];
++ let _ = nested[0].last();
+}
--- /dev/null
- let _ = x.get(x.len() - 1); // ~ERROR Use x.last()
+// run-rustfix
+
+#![warn(clippy::get_last_with_len)]
++#![allow(unused)]
++
++use std::collections::VecDeque;
+
+fn dont_use_last() {
+ let x = vec![2, 3, 5];
- dont_use_last();
- indexing_two_from_end();
- index_into_last();
- use_last_with_different_vec_length();
++ let _ = x.get(x.len() - 1);
+}
+
+fn indexing_two_from_end() {
+ let x = vec![2, 3, 5];
+ let _ = x.get(x.len() - 2);
+}
+
+fn index_into_last() {
+ let x = vec![2, 3, 5];
+ let _ = x[x.len() - 1];
+}
+
+fn use_last_with_different_vec_length() {
+ let x = vec![2, 3, 5];
+ let y = vec!['a', 'b', 'c'];
+ let _ = x.get(y.len() - 1);
+}
+
++struct S {
++ field: Vec<usize>,
++}
++
++fn in_field(s: &S) {
++ let _ = s.field.get(s.field.len() - 1);
++}
++
+fn main() {
++ let slice = &[1, 2, 3];
++ let _ = slice.get(slice.len() - 1);
++
++ let array = [4, 5, 6];
++ let _ = array.get(array.len() - 1);
++
++ let deq = VecDeque::from([7, 8, 9]);
++ let _ = deq.get(deq.len() - 1);
++
++ let nested = [[1]];
++ let _ = nested[0].get(nested[0].len() - 1);
+}
--- /dev/null
- --> $DIR/get_last_with_len.rs:7:13
+error: accessing last element with `x.get(x.len() - 1)`
- LL | let _ = x.get(x.len() - 1); // ~ERROR Use x.last()
++ --> $DIR/get_last_with_len.rs:10:13
+ |
- error: aborting due to previous error
++LL | let _ = x.get(x.len() - 1);
+ | ^^^^^^^^^^^^^^^^^^ help: try: `x.last()`
+ |
+ = note: `-D clippy::get-last-with-len` implied by `-D warnings`
+
++error: accessing last element with `s.field.get(s.field.len() - 1)`
++ --> $DIR/get_last_with_len.rs:34:13
++ |
++LL | let _ = s.field.get(s.field.len() - 1);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `s.field.last()`
++
++error: accessing last element with `slice.get(slice.len() - 1)`
++ --> $DIR/get_last_with_len.rs:39:13
++ |
++LL | let _ = slice.get(slice.len() - 1);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `slice.last()`
++
++error: accessing last element with `array.get(array.len() - 1)`
++ --> $DIR/get_last_with_len.rs:42:13
++ |
++LL | let _ = array.get(array.len() - 1);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `array.last()`
++
++error: accessing last element with `deq.get(deq.len() - 1)`
++ --> $DIR/get_last_with_len.rs:45:13
++ |
++LL | let _ = deq.get(deq.len() - 1);
++ | ^^^^^^^^^^^^^^^^^^^^^^ help: try: `deq.back()`
++
++error: accessing last element with `nested[0].get(nested[0].len() - 1)`
++ --> $DIR/get_last_with_len.rs:48:13
++ |
++LL | let _ = nested[0].get(nested[0].len() - 1);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `nested[0].last()`
++
++error: aborting due to 6 previous errors
+
--- /dev/null
- #![allow(unused_mut, clippy::from_iter_instead_of_collect)]
+// run-rustfix
+
++#![allow(unused_mut, clippy::from_iter_instead_of_collect, clippy::get_first)]
+#![warn(clippy::unwrap_used)]
+#![deny(clippy::get_unwrap)]
+
+use std::collections::BTreeMap;
+use std::collections::HashMap;
+use std::collections::VecDeque;
+
+struct GetFalsePositive {
+ arr: [u32; 3],
+}
+
+impl GetFalsePositive {
+ fn get(&self, pos: usize) -> Option<&u32> {
+ self.arr.get(pos)
+ }
+ fn get_mut(&mut self, pos: usize) -> Option<&mut u32> {
+ self.arr.get_mut(pos)
+ }
+}
+
+fn main() {
+ let mut boxed_slice: Box<[u8]> = Box::new([0, 1, 2, 3]);
+ let mut some_slice = &mut [0, 1, 2, 3];
+ let mut some_vec = vec![0, 1, 2, 3];
+ let mut some_vecdeque: VecDeque<_> = some_vec.iter().cloned().collect();
+ let mut some_hashmap: HashMap<u8, char> = HashMap::from_iter(vec![(1, 'a'), (2, 'b')]);
+ let mut some_btreemap: BTreeMap<u8, char> = BTreeMap::from_iter(vec![(1, 'a'), (2, 'b')]);
+ let mut false_positive = GetFalsePositive { arr: [0, 1, 2] };
+
+ {
+ // Test `get().unwrap()`
+ let _ = &boxed_slice[1];
+ let _ = &some_slice[0];
+ let _ = &some_vec[0];
+ let _ = &some_vecdeque[0];
+ let _ = &some_hashmap[&1];
+ let _ = &some_btreemap[&1];
+ #[allow(clippy::unwrap_used)]
+ let _ = false_positive.get(0).unwrap();
+ // Test with deref
+ let _: u8 = boxed_slice[1];
+ }
+
+ {
+ // Test `get_mut().unwrap()`
+ boxed_slice[0] = 1;
+ some_slice[0] = 1;
+ some_vec[0] = 1;
+ some_vecdeque[0] = 1;
+ // Check false positives
+ #[allow(clippy::unwrap_used)]
+ {
+ *some_hashmap.get_mut(&1).unwrap() = 'b';
+ *some_btreemap.get_mut(&1).unwrap() = 'b';
+ *false_positive.get_mut(0).unwrap() = 1;
+ }
+ }
+
+ {
+ // Test `get().unwrap().foo()` and `get_mut().unwrap().bar()`
+ let _ = some_vec[0..1].to_vec();
+ let _ = some_vec[0..1].to_vec();
+ }
+}
--- /dev/null
- #![allow(unused_mut, clippy::from_iter_instead_of_collect)]
+// run-rustfix
+
++#![allow(unused_mut, clippy::from_iter_instead_of_collect, clippy::get_first)]
+#![warn(clippy::unwrap_used)]
+#![deny(clippy::get_unwrap)]
+
+use std::collections::BTreeMap;
+use std::collections::HashMap;
+use std::collections::VecDeque;
+
+struct GetFalsePositive {
+ arr: [u32; 3],
+}
+
+impl GetFalsePositive {
+ fn get(&self, pos: usize) -> Option<&u32> {
+ self.arr.get(pos)
+ }
+ fn get_mut(&mut self, pos: usize) -> Option<&mut u32> {
+ self.arr.get_mut(pos)
+ }
+}
+
+fn main() {
+ let mut boxed_slice: Box<[u8]> = Box::new([0, 1, 2, 3]);
+ let mut some_slice = &mut [0, 1, 2, 3];
+ let mut some_vec = vec![0, 1, 2, 3];
+ let mut some_vecdeque: VecDeque<_> = some_vec.iter().cloned().collect();
+ let mut some_hashmap: HashMap<u8, char> = HashMap::from_iter(vec![(1, 'a'), (2, 'b')]);
+ let mut some_btreemap: BTreeMap<u8, char> = BTreeMap::from_iter(vec![(1, 'a'), (2, 'b')]);
+ let mut false_positive = GetFalsePositive { arr: [0, 1, 2] };
+
+ {
+ // Test `get().unwrap()`
+ let _ = boxed_slice.get(1).unwrap();
+ let _ = some_slice.get(0).unwrap();
+ let _ = some_vec.get(0).unwrap();
+ let _ = some_vecdeque.get(0).unwrap();
+ let _ = some_hashmap.get(&1).unwrap();
+ let _ = some_btreemap.get(&1).unwrap();
+ #[allow(clippy::unwrap_used)]
+ let _ = false_positive.get(0).unwrap();
+ // Test with deref
+ let _: u8 = *boxed_slice.get(1).unwrap();
+ }
+
+ {
+ // Test `get_mut().unwrap()`
+ *boxed_slice.get_mut(0).unwrap() = 1;
+ *some_slice.get_mut(0).unwrap() = 1;
+ *some_vec.get_mut(0).unwrap() = 1;
+ *some_vecdeque.get_mut(0).unwrap() = 1;
+ // Check false positives
+ #[allow(clippy::unwrap_used)]
+ {
+ *some_hashmap.get_mut(&1).unwrap() = 'b';
+ *some_btreemap.get_mut(&1).unwrap() = 'b';
+ *false_positive.get_mut(0).unwrap() = 1;
+ }
+ }
+
+ {
+ // Test `get().unwrap().foo()` and `get_mut().unwrap().bar()`
+ let _ = some_vec.get(0..1).unwrap().to_vec();
+ let _ = some_vec.get_mut(0..1).unwrap().to_vec();
+ }
+}
--- /dev/null
--- /dev/null
++// run-rustfix
++
++#![warn(clippy::identity_op)]
++#![allow(
++ clippy::eq_op,
++ clippy::no_effect,
++ clippy::unnecessary_operation,
++ clippy::op_ref,
++ clippy::double_parens,
++ unused
++)]
++
++use std::fmt::Write as _;
++
++const ONE: i64 = 1;
++const NEG_ONE: i64 = -1;
++const ZERO: i64 = 0;
++
++struct A(String);
++
++impl std::ops::Shl<i32> for A {
++ type Output = A;
++ fn shl(mut self, other: i32) -> Self {
++ let _ = write!(self.0, "{}", other);
++ self
++ }
++}
++
++struct Length(u8);
++struct Meter;
++
++impl core::ops::Mul<Meter> for u8 {
++ type Output = Length;
++ fn mul(self, _: Meter) -> Length {
++ Length(self)
++ }
++}
++
++#[rustfmt::skip]
++fn main() {
++ let x = 0;
++
++ x;
++ x;
++ x + 1;
++ x;
++ 1 + x;
++ x - ZERO; //no error, as we skip lookups (for now)
++ x;
++ ((ZERO)) | x; //no error, as we skip lookups (for now)
++
++ x;
++ x;
++ x / ONE; //no error, as we skip lookups (for now)
++
++ x / 2; //no false positive
++
++ x & NEG_ONE; //no error, as we skip lookups (for now)
++ x;
++
++ let u: u8 = 0;
++ u;
++
++ 1 << 0; // no error, this case is allowed, see issue 3430
++ 42;
++ 1;
++ 42;
++ &x;
++ x;
++
++ let mut a = A("".into());
++ let b = a << 0; // no error: non-integer
++
++ 1 * Meter; // no error: non-integer
++
++ 2;
++ -2;
++ 2 + x;
++ -2 + x;
++ x + 1;
++ (x + 1) % 3; // no error
++ 4 % 3; // no error
++ 4 % -3; // no error
++
++ // See #8724
++ let a = 0;
++ let b = true;
++ (if b { 1 } else { 2 });
++ (if b { 1 } else { 2 }) + if b { 3 } else { 4 };
++ (match a { 0 => 10, _ => 20 });
++ (match a { 0 => 10, _ => 20 }) + match a { 0 => 30, _ => 40 };
++ (if b { 1 } else { 2 }) + match a { 0 => 30, _ => 40 };
++ (match a { 0 => 10, _ => 20 }) + if b { 3 } else { 4 };
++ (if b { 1 } else { 2 });
++
++ ({ a }) + 3;
++ ({ a } * 2);
++ (loop { let mut c = 0; if c == 10 { break c; } c += 1; }) + { a * 2 };
++
++ fn f(_: i32) {
++ todo!();
++ }
++ f(a + { 8 * 5 });
++ f(if b { 1 } else { 2 } + 3);
++ const _: i32 = { 2 * 4 } + 3;
++ const _: i32 = { 1 + 2 * 3 } + 3;
++
++ a as usize;
++ let _ = a as usize;
++ ({ a } as usize);
++
++ 2 * { a };
++ (({ a } + 4));
++ 1;
++}
++
++pub fn decide(a: bool, b: bool) -> u32 {
++ (if a { 1 } else { 2 }) + if b { 3 } else { 5 }
++}
--- /dev/null
- #[allow(
- clippy::eq_op,
- clippy::no_effect,
- clippy::unnecessary_operation,
- clippy::op_ref,
- clippy::double_parens
- )]
- #[warn(clippy::identity_op)]
++// run-rustfix
++
++#![warn(clippy::identity_op)]
++#![allow(
++ clippy::eq_op,
++ clippy::no_effect,
++ clippy::unnecessary_operation,
++ clippy::op_ref,
++ clippy::double_parens,
++ unused
++)]
++
+use std::fmt::Write as _;
+
+const ONE: i64 = 1;
+const NEG_ONE: i64 = -1;
+const ZERO: i64 = 0;
+
+struct A(String);
+
+impl std::ops::Shl<i32> for A {
+ type Output = A;
+ fn shl(mut self, other: i32) -> Self {
+ let _ = write!(self.0, "{}", other);
+ self
+ }
+}
+
+struct Length(u8);
+struct Meter;
+
+impl core::ops::Mul<Meter> for u8 {
+ type Output = Length;
+ fn mul(self, _: Meter) -> Length {
+ Length(self)
+ }
+}
+
- 0 + if b { 1 } else { 2 } + if b { 3 } else { 4 }; // no error
+#[rustfmt::skip]
+fn main() {
+ let x = 0;
+
+ x + 0;
+ x + (1 - 1);
+ x + 1;
+ 0 + x;
+ 1 + x;
+ x - ZERO; //no error, as we skip lookups (for now)
+ x | (0);
+ ((ZERO)) | x; //no error, as we skip lookups (for now)
+
+ x * 1;
+ 1 * x;
+ x / ONE; //no error, as we skip lookups (for now)
+
+ x / 2; //no false positive
+
+ x & NEG_ONE; //no error, as we skip lookups (for now)
+ -1 & x;
+
+ let u: u8 = 0;
+ u & 255;
+
+ 1 << 0; // no error, this case is allowed, see issue 3430
+ 42 << 0;
+ 1 >> 0;
+ 42 >> 0;
+ &x >> 0;
+ x >> &0;
+
+ let mut a = A("".into());
+ let b = a << 0; // no error: non-integer
+
+ 1 * Meter; // no error: non-integer
+
+ 2 % 3;
+ -2 % 3;
+ 2 % -3 + x;
+ -2 % -3 + x;
+ x + 1 % 3;
+ (x + 1) % 3; // no error
+ 4 % 3; // no error
+ 4 % -3; // no error
+
+ // See #8724
+ let a = 0;
+ let b = true;
+ 0 + if b { 1 } else { 2 };
- 0 + match a { 0 => 10, _ => 20 } + match a { 0 => 30, _ => 40 }; // no error
- 0 + if b { 1 } else { 2 } + match a { 0 => 30, _ => 40 }; // no error
- 0 + match a { 0 => 10, _ => 20 } + if b { 3 } else { 4 }; // no error
-
- 0 + if b { 0 + 1 } else { 2 };
- 0 + match a { 0 => 0 + 10, _ => 20 };
- 0 + if b { 0 + 1 } else { 2 } + match a { 0 => 0 + 30, _ => 40 };
-
- let _ = 0 + if 0 + 1 > 0 { 1 } else { 2 } + if 0 + 1 > 0 { 3 } else { 4 };
- let _ = 0 + match 0 + 1 { 0 => 10, _ => 20 } + match 0 + 1 { 0 => 30, _ => 40 };
-
- 0 + if b { 1 } else { 2 } + if b { 3 } else { 4 } + 0;
-
- 0 + { a } + 3; // no error
- 0 + loop { let mut c = 0; if c == 10 { break c; } c += 1; } + { a * 2 }; // no error
-
++ 0 + if b { 1 } else { 2 } + if b { 3 } else { 4 };
+ 0 + match a { 0 => 10, _ => 20 };
- f(0 + if b { 1 } else { 2 } + 3); // no error
++ 0 + match a { 0 => 10, _ => 20 } + match a { 0 => 30, _ => 40 };
++ 0 + if b { 1 } else { 2 } + match a { 0 => 30, _ => 40 };
++ 0 + match a { 0 => 10, _ => 20 } + if b { 3 } else { 4 };
++ (if b { 1 } else { 2 }) + 0;
++
++ 0 + { a } + 3;
++ 0 + { a } * 2;
++ 0 + loop { let mut c = 0; if c == 10 { break c; } c += 1; } + { a * 2 };
++
+ fn f(_: i32) {
+ todo!();
+ }
+ f(1 * a + { 8 * 5 });
- const _: i32 = 0 + { 1 + 2 * 3 } + 3; // no error
++ f(0 + if b { 1 } else { 2 } + 3);
+ const _: i32 = { 2 * 4 } + 0 + 3;
++ const _: i32 = 0 + { 1 + 2 * 3 } + 3;
++
++ 0 + a as usize;
++ let _ = 0 + a as usize;
++ 0 + { a } as usize;
++
++ 2 * (0 + { a });
++ 1 * ({ a } + 4);
++ 1 * 1;
++}
++
++pub fn decide(a: bool, b: bool) -> u32 {
++ 0 + if a { 1 } else { 2 } + if b { 3 } else { 5 }
+}
--- /dev/null
- error: the operation is ineffective. Consider reducing it to `x`
- --> $DIR/identity_op.rs:39:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:43:5
+ |
+LL | x + 0;
- | ^^^^^
++ | ^^^^^ help: consider reducing it to: `x`
+ |
+ = note: `-D clippy::identity-op` implied by `-D warnings`
+
- error: the operation is ineffective. Consider reducing it to `x`
- --> $DIR/identity_op.rs:40:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:44:5
+ |
+LL | x + (1 - 1);
- | ^^^^^^^^^^^
++ | ^^^^^^^^^^^ help: consider reducing it to: `x`
+
- error: the operation is ineffective. Consider reducing it to `x`
- --> $DIR/identity_op.rs:42:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:46:5
+ |
+LL | 0 + x;
- | ^^^^^
++ | ^^^^^ help: consider reducing it to: `x`
+
- error: the operation is ineffective. Consider reducing it to `x`
- --> $DIR/identity_op.rs:45:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:49:5
+ |
+LL | x | (0);
- | ^^^^^^^
++ | ^^^^^^^ help: consider reducing it to: `x`
+
- error: the operation is ineffective. Consider reducing it to `x`
- --> $DIR/identity_op.rs:48:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:52:5
+ |
+LL | x * 1;
- | ^^^^^
++ | ^^^^^ help: consider reducing it to: `x`
+
- error: the operation is ineffective. Consider reducing it to `x`
- --> $DIR/identity_op.rs:49:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:53:5
+ |
+LL | 1 * x;
- | ^^^^^
++ | ^^^^^ help: consider reducing it to: `x`
+
- error: the operation is ineffective. Consider reducing it to `x`
- --> $DIR/identity_op.rs:55:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:59:5
+ |
+LL | -1 & x;
- | ^^^^^^
++ | ^^^^^^ help: consider reducing it to: `x`
+
- error: the operation is ineffective. Consider reducing it to `u`
- --> $DIR/identity_op.rs:58:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:62:5
+ |
+LL | u & 255;
- | ^^^^^^^
++ | ^^^^^^^ help: consider reducing it to: `u`
+
- error: the operation is ineffective. Consider reducing it to `42`
- --> $DIR/identity_op.rs:61:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:65:5
+ |
+LL | 42 << 0;
- | ^^^^^^^
++ | ^^^^^^^ help: consider reducing it to: `42`
+
- error: the operation is ineffective. Consider reducing it to `1`
- --> $DIR/identity_op.rs:62:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:66:5
+ |
+LL | 1 >> 0;
- | ^^^^^^
++ | ^^^^^^ help: consider reducing it to: `1`
+
- error: the operation is ineffective. Consider reducing it to `42`
- --> $DIR/identity_op.rs:63:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:67:5
+ |
+LL | 42 >> 0;
- | ^^^^^^^
++ | ^^^^^^^ help: consider reducing it to: `42`
+
- error: the operation is ineffective. Consider reducing it to `&x`
- --> $DIR/identity_op.rs:64:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:68:5
+ |
+LL | &x >> 0;
- | ^^^^^^^
++ | ^^^^^^^ help: consider reducing it to: `&x`
+
- error: the operation is ineffective. Consider reducing it to `x`
- --> $DIR/identity_op.rs:65:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:69:5
+ |
+LL | x >> &0;
- | ^^^^^^^
++ | ^^^^^^^ help: consider reducing it to: `x`
+
- error: the operation is ineffective. Consider reducing it to `2`
- --> $DIR/identity_op.rs:72:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:76:5
+ |
+LL | 2 % 3;
- | ^^^^^
++ | ^^^^^ help: consider reducing it to: `2`
+
- error: the operation is ineffective. Consider reducing it to `-2`
- --> $DIR/identity_op.rs:73:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:77:5
+ |
+LL | -2 % 3;
- | ^^^^^^
++ | ^^^^^^ help: consider reducing it to: `-2`
+
- error: the operation is ineffective. Consider reducing it to `2`
- --> $DIR/identity_op.rs:74:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:78:5
+ |
+LL | 2 % -3 + x;
- | ^^^^^^
++ | ^^^^^^ help: consider reducing it to: `2`
+
- error: the operation is ineffective. Consider reducing it to `-2`
- --> $DIR/identity_op.rs:75:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:79:5
+ |
+LL | -2 % -3 + x;
- | ^^^^^^^
++ | ^^^^^^^ help: consider reducing it to: `-2`
+
- error: the operation is ineffective. Consider reducing it to `1`
- --> $DIR/identity_op.rs:76:9
++error: this operation has no effect
++ --> $DIR/identity_op.rs:80:9
+ |
+LL | x + 1 % 3;
- | ^^^^^
++ | ^^^^^ help: consider reducing it to: `1`
+
- error: the operation is ineffective. Consider reducing it to `if b { 1 } else { 2 }`
- --> $DIR/identity_op.rs:84:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:88:5
+ |
+LL | 0 + if b { 1 } else { 2 };
- | ^^^^^^^^^^^^^^^^^^^^^^^^^
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(if b { 1 } else { 2 })`
+
- error: the operation is ineffective. Consider reducing it to `match a { 0 => 10, _ => 20 }`
- --> $DIR/identity_op.rs:86:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:89:5
++ |
++LL | 0 + if b { 1 } else { 2 } + if b { 3 } else { 4 };
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(if b { 1 } else { 2 })`
++
++error: this operation has no effect
++ --> $DIR/identity_op.rs:90:5
+ |
+LL | 0 + match a { 0 => 10, _ => 20 };
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(match a { 0 => 10, _ => 20 })`
+
- error: the operation is ineffective. Consider reducing it to `if b { 0 + 1 } else { 2 }`
++error: this operation has no effect
+ --> $DIR/identity_op.rs:91:5
+ |
- LL | 0 + if b { 0 + 1 } else { 2 };
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++LL | 0 + match a { 0 => 10, _ => 20 } + match a { 0 => 30, _ => 40 };
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(match a { 0 => 10, _ => 20 })`
+
- error: the operation is ineffective. Consider reducing it to `1`
- --> $DIR/identity_op.rs:91:16
++error: this operation has no effect
++ --> $DIR/identity_op.rs:92:5
+ |
- LL | 0 + if b { 0 + 1 } else { 2 };
- | ^^^^^
++LL | 0 + if b { 1 } else { 2 } + match a { 0 => 30, _ => 40 };
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(if b { 1 } else { 2 })`
+
- error: the operation is ineffective. Consider reducing it to `match a { 0 => 0 + 10, _ => 20 }`
- --> $DIR/identity_op.rs:92:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:93:5
++ |
++LL | 0 + match a { 0 => 10, _ => 20 } + if b { 3 } else { 4 };
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(match a { 0 => 10, _ => 20 })`
++
++error: this operation has no effect
++ --> $DIR/identity_op.rs:94:5
++ |
++LL | (if b { 1 } else { 2 }) + 0;
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(if b { 1 } else { 2 })`
++
++error: this operation has no effect
++ --> $DIR/identity_op.rs:96:5
+ |
- LL | 0 + match a { 0 => 0 + 10, _ => 20 };
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++LL | 0 + { a } + 3;
++ | ^^^^^^^^^ help: consider reducing it to: `({ a })`
+
- error: the operation is ineffective. Consider reducing it to `10`
- --> $DIR/identity_op.rs:92:25
++error: this operation has no effect
++ --> $DIR/identity_op.rs:97:5
+ |
- LL | 0 + match a { 0 => 0 + 10, _ => 20 };
- | ^^^^^^
++LL | 0 + { a } * 2;
++ | ^^^^^^^^^^^^^ help: consider reducing it to: `({ a } * 2)`
+
- error: the operation is ineffective. Consider reducing it to `1`
- --> $DIR/identity_op.rs:93:16
++error: this operation has no effect
++ --> $DIR/identity_op.rs:98:5
+ |
- LL | 0 + if b { 0 + 1 } else { 2 } + match a { 0 => 0 + 30, _ => 40 };
- | ^^^^^
++LL | 0 + loop { let mut c = 0; if c == 10 { break c; } c += 1; } + { a * 2 };
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(loop { let mut c = 0; if c == 10 { break c; } c += 1; })`
+
- error: the operation is ineffective. Consider reducing it to `30`
- --> $DIR/identity_op.rs:93:52
++error: this operation has no effect
++ --> $DIR/identity_op.rs:103:7
+ |
- LL | 0 + if b { 0 + 1 } else { 2 } + match a { 0 => 0 + 30, _ => 40 };
- | ^^^^^^
++LL | f(1 * a + { 8 * 5 });
++ | ^^^^^ help: consider reducing it to: `a`
+
- error: the operation is ineffective. Consider reducing it to `1`
- --> $DIR/identity_op.rs:95:20
++error: this operation has no effect
++ --> $DIR/identity_op.rs:104:7
+ |
- LL | let _ = 0 + if 0 + 1 > 0 { 1 } else { 2 } + if 0 + 1 > 0 { 3 } else { 4 };
- | ^^^^^
++LL | f(0 + if b { 1 } else { 2 } + 3);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `if b { 1 } else { 2 }`
+
- error: the operation is ineffective. Consider reducing it to `1`
- --> $DIR/identity_op.rs:95:52
++error: this operation has no effect
++ --> $DIR/identity_op.rs:105:20
+ |
- LL | let _ = 0 + if 0 + 1 > 0 { 1 } else { 2 } + if 0 + 1 > 0 { 3 } else { 4 };
- | ^^^^^
++LL | const _: i32 = { 2 * 4 } + 0 + 3;
++ | ^^^^^^^^^^^^^ help: consider reducing it to: `{ 2 * 4 }`
+
- error: the operation is ineffective. Consider reducing it to `1`
- --> $DIR/identity_op.rs:96:23
++error: this operation has no effect
++ --> $DIR/identity_op.rs:106:20
+ |
- LL | let _ = 0 + match 0 + 1 { 0 => 10, _ => 20 } + match 0 + 1 { 0 => 30, _ => 40 };
- | ^^^^^
++LL | const _: i32 = 0 + { 1 + 2 * 3 } + 3;
++ | ^^^^^^^^^^^^^^^^^ help: consider reducing it to: `{ 1 + 2 * 3 }`
+
- error: the operation is ineffective. Consider reducing it to `1`
- --> $DIR/identity_op.rs:96:58
++error: this operation has no effect
++ --> $DIR/identity_op.rs:108:5
+ |
- LL | let _ = 0 + match 0 + 1 { 0 => 10, _ => 20 } + match 0 + 1 { 0 => 30, _ => 40 };
- | ^^^^^
++LL | 0 + a as usize;
++ | ^^^^^^^^^^^^^^ help: consider reducing it to: `a as usize`
+
- error: the operation is ineffective. Consider reducing it to `0 + if b { 1 } else { 2 } + if b { 3 } else { 4 }`
- --> $DIR/identity_op.rs:98:5
++error: this operation has no effect
++ --> $DIR/identity_op.rs:109:13
+ |
- LL | 0 + if b { 1 } else { 2 } + if b { 3 } else { 4 } + 0;
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++LL | let _ = 0 + a as usize;
++ | ^^^^^^^^^^^^^^ help: consider reducing it to: `a as usize`
+
- error: the operation is ineffective. Consider reducing it to `a`
- --> $DIR/identity_op.rs:106:7
++error: this operation has no effect
++ --> $DIR/identity_op.rs:110:5
+ |
- LL | f(1 * a + { 8 * 5 });
- | ^^^^^
++LL | 0 + { a } as usize;
++ | ^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `({ a } as usize)`
+
- error: the operation is ineffective. Consider reducing it to `{ 2 * 4 }`
- --> $DIR/identity_op.rs:108:20
++error: this operation has no effect
++ --> $DIR/identity_op.rs:112:9
+ |
- LL | const _: i32 = { 2 * 4 } + 0 + 3;
- | ^^^^^^^^^^^^^
++LL | 2 * (0 + { a });
++ | ^^^^^^^^^^^ help: consider reducing it to: `{ a }`
++
++error: this operation has no effect
++ --> $DIR/identity_op.rs:113:5
++ |
++LL | 1 * ({ a } + 4);
++ | ^^^^^^^^^^^^^^^ help: consider reducing it to: `(({ a } + 4))`
++
++error: this operation has no effect
++ --> $DIR/identity_op.rs:114:5
++ |
++LL | 1 * 1;
++ | ^^^^^ help: consider reducing it to: `1`
++
++error: this operation has no effect
++ --> $DIR/identity_op.rs:118:5
++ |
++LL | 0 + if a { 1 } else { 2 } + if b { 3 } else { 5 }
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(if a { 1 } else { 2 })`
+
- error: aborting due to 33 previous errors
++error: aborting due to 39 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::implicit_clone)]
++#![allow(clippy::clone_on_copy, clippy::redundant_clone)]
++use std::borrow::Borrow;
++use std::ffi::{OsStr, OsString};
++use std::path::PathBuf;
++
++fn return_owned_from_slice(slice: &[u32]) -> Vec<u32> {
++ slice.to_owned()
++}
++
++pub fn own_same<T>(v: T) -> T
++where
++ T: ToOwned<Owned = T>,
++{
++ v.to_owned()
++}
++
++pub fn own_same_from_ref<T>(v: &T) -> T
++where
++ T: ToOwned<Owned = T>,
++{
++ v.to_owned()
++}
++
++pub fn own_different<T, U>(v: T) -> U
++where
++ T: ToOwned<Owned = U>,
++{
++ v.to_owned()
++}
++
++#[derive(Copy, Clone)]
++struct Kitten;
++impl Kitten {
++ // badly named method
++ fn to_vec(self) -> Kitten {
++ Kitten {}
++ }
++}
++impl Borrow<BorrowedKitten> for Kitten {
++ fn borrow(&self) -> &BorrowedKitten {
++ static VALUE: BorrowedKitten = BorrowedKitten {};
++ &VALUE
++ }
++}
++
++struct BorrowedKitten;
++impl ToOwned for BorrowedKitten {
++ type Owned = Kitten;
++ fn to_owned(&self) -> Kitten {
++ Kitten {}
++ }
++}
++
++mod weird {
++ #[allow(clippy::ptr_arg)]
++ pub fn to_vec(v: &Vec<u32>) -> Vec<u32> {
++ v.clone()
++ }
++}
++
++fn main() {
++ let vec = vec![5];
++ let _ = return_owned_from_slice(&vec);
++ let _ = vec.clone();
++ let _ = vec.clone();
++
++ let vec_ref = &vec;
++ let _ = return_owned_from_slice(vec_ref);
++ let _ = vec_ref.clone();
++ let _ = vec_ref.clone();
++
++ // we expect no lint for this
++ let _ = weird::to_vec(&vec);
++
++ // we expect no lints for this
++ let slice: &[u32] = &[1, 2, 3, 4, 5];
++ let _ = return_owned_from_slice(slice);
++ let _ = slice.to_owned();
++ let _ = slice.to_vec();
++
++ let str = "hello world".to_string();
++ let _ = str.clone();
++
++ // testing w/ an arbitrary type
++ let kitten = Kitten {};
++ let _ = kitten.clone();
++ let _ = own_same_from_ref(&kitten);
++ // this shouln't lint
++ let _ = kitten.to_vec();
++
++ // we expect no lints for this
++ let borrowed = BorrowedKitten {};
++ let _ = borrowed.to_owned();
++
++ let pathbuf = PathBuf::new();
++ let _ = pathbuf.clone();
++ let _ = pathbuf.clone();
++
++ let os_string = OsString::from("foo");
++ let _ = os_string.clone();
++ let _ = os_string.clone();
++
++ // we expect no lints for this
++ let os_str = OsStr::new("foo");
++ let _ = os_str.to_owned();
++ let _ = os_str.to_os_string();
++
++ // issue #8227
++ let pathbuf_ref = &pathbuf;
++ let pathbuf_ref = &pathbuf_ref;
++ let _ = pathbuf_ref.to_owned(); // Don't lint. Returns `&PathBuf`
++ let _ = (*pathbuf_ref).clone();
++ let pathbuf_ref = &pathbuf_ref;
++ let _ = pathbuf_ref.to_owned(); // Don't lint. Returns `&&PathBuf`
++ let _ = (**pathbuf_ref).clone();
++}
--- /dev/null
- #![allow(clippy::redundant_clone)]
++// run-rustfix
+#![warn(clippy::implicit_clone)]
++#![allow(clippy::clone_on_copy, clippy::redundant_clone)]
+use std::borrow::Borrow;
+use std::ffi::{OsStr, OsString};
+use std::path::PathBuf;
+
+fn return_owned_from_slice(slice: &[u32]) -> Vec<u32> {
+ slice.to_owned()
+}
+
+pub fn own_same<T>(v: T) -> T
+where
+ T: ToOwned<Owned = T>,
+{
+ v.to_owned()
+}
+
+pub fn own_same_from_ref<T>(v: &T) -> T
+where
+ T: ToOwned<Owned = T>,
+{
+ v.to_owned()
+}
+
+pub fn own_different<T, U>(v: T) -> U
+where
+ T: ToOwned<Owned = U>,
+{
+ v.to_owned()
+}
+
+#[derive(Copy, Clone)]
+struct Kitten;
+impl Kitten {
+ // badly named method
+ fn to_vec(self) -> Kitten {
+ Kitten {}
+ }
+}
+impl Borrow<BorrowedKitten> for Kitten {
+ fn borrow(&self) -> &BorrowedKitten {
+ static VALUE: BorrowedKitten = BorrowedKitten {};
+ &VALUE
+ }
+}
+
+struct BorrowedKitten;
+impl ToOwned for BorrowedKitten {
+ type Owned = Kitten;
+ fn to_owned(&self) -> Kitten {
+ Kitten {}
+ }
+}
+
+mod weird {
+ #[allow(clippy::ptr_arg)]
+ pub fn to_vec(v: &Vec<u32>) -> Vec<u32> {
+ v.clone()
+ }
+}
+
+fn main() {
+ let vec = vec![5];
+ let _ = return_owned_from_slice(&vec);
+ let _ = vec.to_owned();
+ let _ = vec.to_vec();
+
+ let vec_ref = &vec;
+ let _ = return_owned_from_slice(vec_ref);
+ let _ = vec_ref.to_owned();
+ let _ = vec_ref.to_vec();
+
+ // we expect no lint for this
+ let _ = weird::to_vec(&vec);
+
+ // we expect no lints for this
+ let slice: &[u32] = &[1, 2, 3, 4, 5];
+ let _ = return_owned_from_slice(slice);
+ let _ = slice.to_owned();
+ let _ = slice.to_vec();
+
+ let str = "hello world".to_string();
+ let _ = str.to_owned();
+
+ // testing w/ an arbitrary type
+ let kitten = Kitten {};
+ let _ = kitten.to_owned();
+ let _ = own_same_from_ref(&kitten);
+ // this shouln't lint
+ let _ = kitten.to_vec();
+
+ // we expect no lints for this
+ let borrowed = BorrowedKitten {};
+ let _ = borrowed.to_owned();
+
+ let pathbuf = PathBuf::new();
+ let _ = pathbuf.to_owned();
+ let _ = pathbuf.to_path_buf();
+
+ let os_string = OsString::from("foo");
+ let _ = os_string.to_owned();
+ let _ = os_string.to_os_string();
+
+ // we expect no lints for this
+ let os_str = OsStr::new("foo");
+ let _ = os_str.to_owned();
+ let _ = os_str.to_os_string();
+
+ // issue #8227
+ let pathbuf_ref = &pathbuf;
+ let pathbuf_ref = &pathbuf_ref;
+ let _ = pathbuf_ref.to_owned(); // Don't lint. Returns `&PathBuf`
+ let _ = pathbuf_ref.to_path_buf();
+ let pathbuf_ref = &pathbuf_ref;
+ let _ = pathbuf_ref.to_owned(); // Don't lint. Returns `&&PathBuf`
+ let _ = pathbuf_ref.to_path_buf();
+}
--- /dev/null
- --> $DIR/implicit_clone.rs:65:13
+error: implicitly cloning a `Vec` by calling `to_owned` on its dereferenced type
- --> $DIR/implicit_clone.rs:66:13
++ --> $DIR/implicit_clone.rs:66:13
+ |
+LL | let _ = vec.to_owned();
+ | ^^^^^^^^^^^^^^ help: consider using: `vec.clone()`
+ |
+ = note: `-D clippy::implicit-clone` implied by `-D warnings`
+
+error: implicitly cloning a `Vec` by calling `to_vec` on its dereferenced type
- --> $DIR/implicit_clone.rs:70:13
++ --> $DIR/implicit_clone.rs:67:13
+ |
+LL | let _ = vec.to_vec();
+ | ^^^^^^^^^^^^ help: consider using: `vec.clone()`
+
+error: implicitly cloning a `Vec` by calling `to_owned` on its dereferenced type
- --> $DIR/implicit_clone.rs:71:13
++ --> $DIR/implicit_clone.rs:71:13
+ |
+LL | let _ = vec_ref.to_owned();
+ | ^^^^^^^^^^^^^^^^^^ help: consider using: `vec_ref.clone()`
+
+error: implicitly cloning a `Vec` by calling `to_vec` on its dereferenced type
- --> $DIR/implicit_clone.rs:83:13
++ --> $DIR/implicit_clone.rs:72:13
+ |
+LL | let _ = vec_ref.to_vec();
+ | ^^^^^^^^^^^^^^^^ help: consider using: `vec_ref.clone()`
+
+error: implicitly cloning a `String` by calling `to_owned` on its dereferenced type
- --> $DIR/implicit_clone.rs:87:13
++ --> $DIR/implicit_clone.rs:84:13
+ |
+LL | let _ = str.to_owned();
+ | ^^^^^^^^^^^^^^ help: consider using: `str.clone()`
+
+error: implicitly cloning a `Kitten` by calling `to_owned` on its dereferenced type
- --> $DIR/implicit_clone.rs:97:13
++ --> $DIR/implicit_clone.rs:88:13
+ |
+LL | let _ = kitten.to_owned();
+ | ^^^^^^^^^^^^^^^^^ help: consider using: `kitten.clone()`
+
+error: implicitly cloning a `PathBuf` by calling `to_owned` on its dereferenced type
- --> $DIR/implicit_clone.rs:98:13
++ --> $DIR/implicit_clone.rs:98:13
+ |
+LL | let _ = pathbuf.to_owned();
+ | ^^^^^^^^^^^^^^^^^^ help: consider using: `pathbuf.clone()`
+
+error: implicitly cloning a `PathBuf` by calling `to_path_buf` on its dereferenced type
- --> $DIR/implicit_clone.rs:101:13
++ --> $DIR/implicit_clone.rs:99:13
+ |
+LL | let _ = pathbuf.to_path_buf();
+ | ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `pathbuf.clone()`
+
+error: implicitly cloning a `OsString` by calling `to_owned` on its dereferenced type
- --> $DIR/implicit_clone.rs:102:13
++ --> $DIR/implicit_clone.rs:102:13
+ |
+LL | let _ = os_string.to_owned();
+ | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `os_string.clone()`
+
+error: implicitly cloning a `OsString` by calling `to_os_string` on its dereferenced type
- --> $DIR/implicit_clone.rs:113:13
++ --> $DIR/implicit_clone.rs:103:13
+ |
+LL | let _ = os_string.to_os_string();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `os_string.clone()`
+
+error: implicitly cloning a `PathBuf` by calling `to_path_buf` on its dereferenced type
- --> $DIR/implicit_clone.rs:116:13
++ --> $DIR/implicit_clone.rs:114:13
+ |
+LL | let _ = pathbuf_ref.to_path_buf();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(*pathbuf_ref).clone()`
+
+error: implicitly cloning a `PathBuf` by calling `to_path_buf` on its dereferenced type
++ --> $DIR/implicit_clone.rs:117:13
+ |
+LL | let _ = pathbuf_ref.to_path_buf();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(**pathbuf_ref).clone()`
+
+error: aborting due to 12 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![deny(clippy::while_let_on_iterator)]
++#![allow(unused_mut)]
++
++use std::iter::Iterator;
++
++struct Foo;
++
++impl Foo {
++ fn foo1<I: Iterator<Item = usize>>(mut it: I) {
++ while let Some(_) = it.next() {
++ println!("{:?}", it.size_hint());
++ }
++ }
++
++ fn foo2<I: Iterator<Item = usize>>(mut it: I) {
++ for e in it {
++ println!("{:?}", e);
++ }
++ }
++}
++
++fn main() {
++ Foo::foo1(vec![].into_iter());
++ Foo::foo2(vec![].into_iter());
++}
--- /dev/null
++// run-rustfix
+#![deny(clippy::while_let_on_iterator)]
++#![allow(unused_mut)]
+
+use std::iter::Iterator;
+
+struct Foo;
+
+impl Foo {
+ fn foo1<I: Iterator<Item = usize>>(mut it: I) {
+ while let Some(_) = it.next() {
+ println!("{:?}", it.size_hint());
+ }
+ }
+
+ fn foo2<I: Iterator<Item = usize>>(mut it: I) {
+ while let Some(e) = it.next() {
+ println!("{:?}", e);
+ }
+ }
+}
+
+fn main() {
+ Foo::foo1(vec![].into_iter());
+ Foo::foo2(vec![].into_iter());
+}
--- /dev/null
- --> $DIR/issue_2356.rs:15:9
+error: this loop could be written as a `for` loop
- --> $DIR/issue_2356.rs:1:9
++ --> $DIR/issue_2356.rs:17:9
+ |
+LL | while let Some(e) = it.next() {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `for e in it`
+ |
+note: the lint level is defined here
++ --> $DIR/issue_2356.rs:2:9
+ |
+LL | #![deny(clippy::while_let_on_iterator)]
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
--- /dev/null
- let _ = s.get(0);
- // Should be replaced by s.get(0)
+// run-rustfix
+#![warn(clippy::iter_next_slice)]
+
+fn main() {
+ // test code goes here
+ let s = [1, 2, 3];
+ let v = vec![1, 2, 3];
+
- let _ = v.get(0);
- // Should be replaced by v.get(0)
++ let _ = s.first();
++ // Should be replaced by s.first()
+
+ let _ = s.get(2);
+ // Should be replaced by s.get(2)
+
+ let _ = v.get(5);
+ // Should be replaced by v.get(5)
+
++ let _ = v.first();
++ // Should be replaced by v.first()
+
+ let o = Some(5);
+ o.iter().next();
+ // Shouldn't be linted since this is not a Slice or an Array
+}
--- /dev/null
- // Should be replaced by s.get(0)
+// run-rustfix
+#![warn(clippy::iter_next_slice)]
+
+fn main() {
+ // test code goes here
+ let s = [1, 2, 3];
+ let v = vec![1, 2, 3];
+
+ let _ = s.iter().next();
- // Should be replaced by v.get(0)
++ // Should be replaced by s.first()
+
+ let _ = s[2..].iter().next();
+ // Should be replaced by s.get(2)
+
+ let _ = v[5..].iter().next();
+ // Should be replaced by v.get(5)
+
+ let _ = v.iter().next();
++ // Should be replaced by v.first()
+
+ let o = Some(5);
+ o.iter().next();
+ // Shouldn't be linted since this is not a Slice or an Array
+}
--- /dev/null
- | ^^^^^^^^^^^^^^^ help: try calling: `s.get(0)`
+error: using `.iter().next()` on an array
+ --> $DIR/iter_next_slice.rs:9:13
+ |
+LL | let _ = s.iter().next();
- | ^^^^^^^^^^^^^^^ help: try calling: `v.get(0)`
++ | ^^^^^^^^^^^^^^^ help: try calling: `s.first()`
+ |
+ = note: `-D clippy::iter-next-slice` implied by `-D warnings`
+
+error: using `.iter().next()` on a Slice without end index
+ --> $DIR/iter_next_slice.rs:12:13
+ |
+LL | let _ = s[2..].iter().next();
+ | ^^^^^^^^^^^^^^^^^^^^ help: try calling: `s.get(2)`
+
+error: using `.iter().next()` on a Slice without end index
+ --> $DIR/iter_next_slice.rs:15:13
+ |
+LL | let _ = v[5..].iter().next();
+ | ^^^^^^^^^^^^^^^^^^^^ help: try calling: `v.get(5)`
+
+error: using `.iter().next()` on an array
+ --> $DIR/iter_next_slice.rs:18:13
+ |
+LL | let _ = v.iter().next();
++ | ^^^^^^^^^^^^^^^ help: try calling: `v.first()`
+
+error: aborting due to 4 previous errors
+
--- /dev/null
+// aux-build:macro_rules.rs
+
+#![allow(dead_code)]
+#![allow(unused_variables)]
+#![warn(clippy::large_enum_variant)]
+
+#[macro_use]
+extern crate macro_rules;
+
+enum LargeEnum {
+ A(i32),
+ B([i32; 8000]),
+}
+
+enum GenericEnumOk<T> {
+ A(i32),
+ B([T; 8000]),
+}
+
+enum GenericEnum2<T> {
+ A(i32),
+ B([i32; 8000]),
+ C(T, [i32; 8000]),
+}
+
+trait SomeTrait {
+ type Item;
+}
+
+enum LargeEnumGeneric<A: SomeTrait> {
+ Var(A::Item),
+}
+
+enum LargeEnum2 {
+ VariantOk(i32, u32),
+ ContainingLargeEnum(LargeEnum),
+}
+
+enum LargeEnum3 {
+ ContainingMoreThanOneField(i32, [i32; 8000], [i32; 9500]),
+ VoidVariant,
+ StructLikeLittle { x: i32, y: i32 },
+}
+
+enum LargeEnum4 {
+ VariantOk(i32, u32),
+ StructLikeLarge { x: [i32; 8000], y: i32 },
+}
+
+enum LargeEnum5 {
+ VariantOk(i32, u32),
+ StructLikeLarge2 { x: [i32; 8000] },
+}
+
+enum LargeEnumOk {
+ LargeA([i32; 8000]),
+ LargeB([i32; 8001]),
+}
+
+enum LargeEnum6 {
+ A,
+ B([u8; 255]),
+ C([u8; 200]),
+}
+
+enum LargeEnum7 {
+ A,
+ B([u8; 1255]),
+ C([u8; 200]),
+}
+
+enum LargeEnum8 {
+ VariantOk(i32, u32),
+ ContainingMoreThanOneField([i32; 8000], [i32; 2], [i32; 9500], [i32; 30]),
+}
+
+enum LargeEnum9 {
+ A(Struct<()>),
+ B(Struct2),
+}
+
+enum LargeEnumOk2<T> {
+ A(T),
+ B(Struct2),
+}
+
+enum LargeEnumOk3<T> {
+ A(Struct<T>),
+ B(Struct2),
+}
+
+struct Struct<T> {
+ a: i32,
+ t: T,
+}
+
+struct Struct2 {
+ a: [i32; 8000],
+}
+
++#[derive(Copy, Clone)]
++enum CopyableLargeEnum {
++ A(bool),
++ B([u128; 4000]),
++}
++
++enum ManuallyCopyLargeEnum {
++ A(bool),
++ B([u128; 4000]),
++}
++
++impl Clone for ManuallyCopyLargeEnum {
++ fn clone(&self) -> Self {
++ *self
++ }
++}
++
++impl Copy for ManuallyCopyLargeEnum {}
++
++enum SomeGenericPossiblyCopyEnum<T> {
++ A(bool, std::marker::PhantomData<T>),
++ B([u64; 4000]),
++}
++
++impl<T: Copy> Clone for SomeGenericPossiblyCopyEnum<T> {
++ fn clone(&self) -> Self {
++ *self
++ }
++}
++
++impl<T: Copy> Copy for SomeGenericPossiblyCopyEnum<T> {}
++
+fn main() {
+ large_enum_variant!();
+}
--- /dev/null
- error: aborting due to 8 previous errors
+error: large size difference between variants
+ --> $DIR/large_enum_variant.rs:12:5
+ |
+LL | B([i32; 8000]),
+ | ^^^^^^^^^^^^^^ this variant is 32000 bytes
+ |
+ = note: `-D clippy::large-enum-variant` implied by `-D warnings`
+note: and the second-largest variant is 4 bytes:
+ --> $DIR/large_enum_variant.rs:11:5
+ |
+LL | A(i32),
+ | ^^^^^^
+help: consider boxing the large fields to reduce the total size of the enum
+ |
+LL | B(Box<[i32; 8000]>),
+ | ~~~~~~~~~~~~~~~~
+
+error: large size difference between variants
+ --> $DIR/large_enum_variant.rs:36:5
+ |
+LL | ContainingLargeEnum(LargeEnum),
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this variant is 32004 bytes
+ |
+note: and the second-largest variant is 8 bytes:
+ --> $DIR/large_enum_variant.rs:35:5
+ |
+LL | VariantOk(i32, u32),
+ | ^^^^^^^^^^^^^^^^^^^
+help: consider boxing the large fields to reduce the total size of the enum
+ |
+LL | ContainingLargeEnum(Box<LargeEnum>),
+ | ~~~~~~~~~~~~~~
+
+error: large size difference between variants
+ --> $DIR/large_enum_variant.rs:40:5
+ |
+LL | ContainingMoreThanOneField(i32, [i32; 8000], [i32; 9500]),
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this variant is 70004 bytes
+ |
+note: and the second-largest variant is 8 bytes:
+ --> $DIR/large_enum_variant.rs:42:5
+ |
+LL | StructLikeLittle { x: i32, y: i32 },
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: consider boxing the large fields to reduce the total size of the enum
+ |
+LL | ContainingMoreThanOneField(i32, Box<[i32; 8000]>, Box<[i32; 9500]>),
+ | ~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~
+
+error: large size difference between variants
+ --> $DIR/large_enum_variant.rs:47:5
+ |
+LL | StructLikeLarge { x: [i32; 8000], y: i32 },
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this variant is 32004 bytes
+ |
+note: and the second-largest variant is 8 bytes:
+ --> $DIR/large_enum_variant.rs:46:5
+ |
+LL | VariantOk(i32, u32),
+ | ^^^^^^^^^^^^^^^^^^^
+help: consider boxing the large fields to reduce the total size of the enum
+ |
+LL | StructLikeLarge { x: Box<[i32; 8000]>, y: i32 },
+ | ~~~~~~~~~~~~~~~~
+
+error: large size difference between variants
+ --> $DIR/large_enum_variant.rs:52:5
+ |
+LL | StructLikeLarge2 { x: [i32; 8000] },
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this variant is 32000 bytes
+ |
+note: and the second-largest variant is 8 bytes:
+ --> $DIR/large_enum_variant.rs:51:5
+ |
+LL | VariantOk(i32, u32),
+ | ^^^^^^^^^^^^^^^^^^^
+help: consider boxing the large fields to reduce the total size of the enum
+ |
+LL | StructLikeLarge2 { x: Box<[i32; 8000]> },
+ | ~~~~~~~~~~~~~~~~
+
+error: large size difference between variants
+ --> $DIR/large_enum_variant.rs:68:5
+ |
+LL | B([u8; 1255]),
+ | ^^^^^^^^^^^^^ this variant is 1255 bytes
+ |
+note: and the second-largest variant is 200 bytes:
+ --> $DIR/large_enum_variant.rs:69:5
+ |
+LL | C([u8; 200]),
+ | ^^^^^^^^^^^^
+help: consider boxing the large fields to reduce the total size of the enum
+ |
+LL | B(Box<[u8; 1255]>),
+ | ~~~~~~~~~~~~~~~
+
+error: large size difference between variants
+ --> $DIR/large_enum_variant.rs:74:5
+ |
+LL | ContainingMoreThanOneField([i32; 8000], [i32; 2], [i32; 9500], [i32; 30]),
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this variant is 70128 bytes
+ |
+note: and the second-largest variant is 8 bytes:
+ --> $DIR/large_enum_variant.rs:73:5
+ |
+LL | VariantOk(i32, u32),
+ | ^^^^^^^^^^^^^^^^^^^
+help: consider boxing the large fields to reduce the total size of the enum
+ |
+LL | ContainingMoreThanOneField(Box<[i32; 8000]>, [i32; 2], Box<[i32; 9500]>, [i32; 30]),
+ | ~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~
+
+error: large size difference between variants
+ --> $DIR/large_enum_variant.rs:79:5
+ |
+LL | B(Struct2),
+ | ^^^^^^^^^^ this variant is 32000 bytes
+ |
+note: and the second-largest variant is 4 bytes:
+ --> $DIR/large_enum_variant.rs:78:5
+ |
+LL | A(Struct<()>),
+ | ^^^^^^^^^^^^^
+help: consider boxing the large fields to reduce the total size of the enum
+ |
+LL | B(Box<Struct2>),
+ | ~~~~~~~~~~~~
+
++error: large size difference between variants
++ --> $DIR/large_enum_variant.rs:104:5
++ |
++LL | B([u128; 4000]),
++ | ^^^^^^^^^^^^^^^ this variant is 64000 bytes
++ |
++note: and the second-largest variant is 1 bytes:
++ --> $DIR/large_enum_variant.rs:103:5
++ |
++LL | A(bool),
++ | ^^^^^^^
++note: boxing a variant would require the type no longer be `Copy`
++ --> $DIR/large_enum_variant.rs:102:6
++ |
++LL | enum CopyableLargeEnum {
++ | ^^^^^^^^^^^^^^^^^
++help: consider boxing the large fields to reduce the total size of the enum
++ --> $DIR/large_enum_variant.rs:104:5
++ |
++LL | B([u128; 4000]),
++ | ^^^^^^^^^^^^^^^
++
++error: large size difference between variants
++ --> $DIR/large_enum_variant.rs:109:5
++ |
++LL | B([u128; 4000]),
++ | ^^^^^^^^^^^^^^^ this variant is 64000 bytes
++ |
++note: and the second-largest variant is 1 bytes:
++ --> $DIR/large_enum_variant.rs:108:5
++ |
++LL | A(bool),
++ | ^^^^^^^
++note: boxing a variant would require the type no longer be `Copy`
++ --> $DIR/large_enum_variant.rs:107:6
++ |
++LL | enum ManuallyCopyLargeEnum {
++ | ^^^^^^^^^^^^^^^^^^^^^
++help: consider boxing the large fields to reduce the total size of the enum
++ --> $DIR/large_enum_variant.rs:109:5
++ |
++LL | B([u128; 4000]),
++ | ^^^^^^^^^^^^^^^
++
++error: large size difference between variants
++ --> $DIR/large_enum_variant.rs:122:5
++ |
++LL | B([u64; 4000]),
++ | ^^^^^^^^^^^^^^ this variant is 32000 bytes
++ |
++note: and the second-largest variant is 1 bytes:
++ --> $DIR/large_enum_variant.rs:121:5
++ |
++LL | A(bool, std::marker::PhantomData<T>),
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++note: boxing a variant would require the type no longer be `Copy`
++ --> $DIR/large_enum_variant.rs:120:6
++ |
++LL | enum SomeGenericPossiblyCopyEnum<T> {
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
++help: consider boxing the large fields to reduce the total size of the enum
++ --> $DIR/large_enum_variant.rs:122:5
++ |
++LL | B([u64; 4000]),
++ | ^^^^^^^^^^^^^^
++
++error: aborting due to 11 previous errors
+
--- /dev/null
+// run-rustfix
+
+#![warn(clippy::all, clippy::pedantic)]
+#![allow(clippy::let_underscore_drop)]
+#![allow(clippy::missing_docs_in_private_items)]
+#![allow(clippy::map_identity)]
+#![allow(clippy::redundant_closure)]
+#![allow(clippy::unnecessary_wraps)]
+#![feature(result_flattening)]
+
+fn main() {
+ // mapping to Option on Iterator
+ fn option_id(x: i8) -> Option<i8> {
+ Some(x)
+ }
+ let option_id_ref: fn(i8) -> Option<i8> = option_id;
+ let option_id_closure = |x| Some(x);
+ let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id).collect();
+ let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id_ref).collect();
+ let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id_closure).collect();
+ let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(|x| x.checked_add(1)).collect();
+
+ // mapping to Iterator on Iterator
+ let _: Vec<_> = vec![5_i8; 6].into_iter().flat_map(|x| 0..x).collect();
+
+ // mapping to Option on Option
+ let _: Option<_> = (Some(Some(1))).and_then(|x| x);
+
+ // mapping to Result on Result
+ let _: Result<_, &str> = (Ok(Ok(1))).and_then(|x| x);
++
++ issue8734();
++ issue8878();
++}
++
++fn issue8734() {
++ // let _ = [0u8, 1, 2, 3]
++ // .into_iter()
++ // .map(|n| match n {
++ // 1 => [n
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)],
++ // n => [n],
++ // })
++ // .flatten();
++}
++
++#[allow(clippy::bind_instead_of_map)] // map + flatten will be suggested to `and_then`, but afterwards `map` is suggested again
++#[rustfmt::skip] // whitespace is important for this one
++fn issue8878() {
++ std::collections::HashMap::<u32, u32>::new()
++ .get(&0)
++ .and_then(|_| {
++// we need some newlines
++// so that the span is big enough
++// we need some newlines
++// so that the span is big enough
++// for a splitted output of the diagnostic
++ Some("")
++ // whitespace beforehand is important as well
++ });
+}
--- /dev/null
+// run-rustfix
+
+#![warn(clippy::all, clippy::pedantic)]
+#![allow(clippy::let_underscore_drop)]
+#![allow(clippy::missing_docs_in_private_items)]
+#![allow(clippy::map_identity)]
+#![allow(clippy::redundant_closure)]
+#![allow(clippy::unnecessary_wraps)]
+#![feature(result_flattening)]
+
+fn main() {
+ // mapping to Option on Iterator
+ fn option_id(x: i8) -> Option<i8> {
+ Some(x)
+ }
+ let option_id_ref: fn(i8) -> Option<i8> = option_id;
+ let option_id_closure = |x| Some(x);
+ let _: Vec<_> = vec![5_i8; 6].into_iter().map(option_id).flatten().collect();
+ let _: Vec<_> = vec![5_i8; 6].into_iter().map(option_id_ref).flatten().collect();
+ let _: Vec<_> = vec![5_i8; 6].into_iter().map(option_id_closure).flatten().collect();
+ let _: Vec<_> = vec![5_i8; 6].into_iter().map(|x| x.checked_add(1)).flatten().collect();
+
+ // mapping to Iterator on Iterator
+ let _: Vec<_> = vec![5_i8; 6].into_iter().map(|x| 0..x).flatten().collect();
+
+ // mapping to Option on Option
+ let _: Option<_> = (Some(Some(1))).map(|x| x).flatten();
+
+ // mapping to Result on Result
+ let _: Result<_, &str> = (Ok(Ok(1))).map(|x| x).flatten();
++
++ issue8734();
++ issue8878();
++}
++
++fn issue8734() {
++ // let _ = [0u8, 1, 2, 3]
++ // .into_iter()
++ // .map(|n| match n {
++ // 1 => [n
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)
++ // .saturating_add(1)],
++ // n => [n],
++ // })
++ // .flatten();
++}
++
++#[allow(clippy::bind_instead_of_map)] // map + flatten will be suggested to `and_then`, but afterwards `map` is suggested again
++#[rustfmt::skip] // whitespace is important for this one
++fn issue8878() {
++ std::collections::HashMap::<u32, u32>::new()
++ .get(&0)
++ .map(|_| {
++// we need some newlines
++// so that the span is big enough
++// for a splitted output of the diagnostic
++ Some("")
++ // whitespace beforehand is important as well
++ })
++ .flatten();
+}
--- /dev/null
- error: aborting due to 7 previous errors
+error: called `map(..).flatten()` on `Iterator`
+ --> $DIR/map_flatten_fixable.rs:18:47
+ |
+LL | let _: Vec<_> = vec![5_i8; 6].into_iter().map(option_id).flatten().collect();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: `-D clippy::map-flatten` implied by `-D warnings`
+help: try replacing `map` with `filter_map`, and remove the `.flatten()`
+ |
+LL | let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id).collect();
+ | ~~~~~~~~~~~~~~~~~~~~~
+
+error: called `map(..).flatten()` on `Iterator`
+ --> $DIR/map_flatten_fixable.rs:19:47
+ |
+LL | let _: Vec<_> = vec![5_i8; 6].into_iter().map(option_id_ref).flatten().collect();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try replacing `map` with `filter_map`, and remove the `.flatten()`
+ |
+LL | let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id_ref).collect();
+ | ~~~~~~~~~~~~~~~~~~~~~~~~~
+
+error: called `map(..).flatten()` on `Iterator`
+ --> $DIR/map_flatten_fixable.rs:20:47
+ |
+LL | let _: Vec<_> = vec![5_i8; 6].into_iter().map(option_id_closure).flatten().collect();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try replacing `map` with `filter_map`, and remove the `.flatten()`
+ |
+LL | let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(option_id_closure).collect();
+ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+error: called `map(..).flatten()` on `Iterator`
+ --> $DIR/map_flatten_fixable.rs:21:47
+ |
+LL | let _: Vec<_> = vec![5_i8; 6].into_iter().map(|x| x.checked_add(1)).flatten().collect();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try replacing `map` with `filter_map`, and remove the `.flatten()`
+ |
+LL | let _: Vec<_> = vec![5_i8; 6].into_iter().filter_map(|x| x.checked_add(1)).collect();
+ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+error: called `map(..).flatten()` on `Iterator`
+ --> $DIR/map_flatten_fixable.rs:24:47
+ |
+LL | let _: Vec<_> = vec![5_i8; 6].into_iter().map(|x| 0..x).flatten().collect();
+ | ^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try replacing `map` with `flat_map`, and remove the `.flatten()`
+ |
+LL | let _: Vec<_> = vec![5_i8; 6].into_iter().flat_map(|x| 0..x).collect();
+ | ~~~~~~~~~~~~~~~~~~
+
+error: called `map(..).flatten()` on `Option`
+ --> $DIR/map_flatten_fixable.rs:27:40
+ |
+LL | let _: Option<_> = (Some(Some(1))).map(|x| x).flatten();
+ | ^^^^^^^^^^^^^^^^^^^^
+ |
+help: try replacing `map` with `and_then`, and remove the `.flatten()`
+ |
+LL | let _: Option<_> = (Some(Some(1))).and_then(|x| x);
+ | ~~~~~~~~~~~~~~~
+
+error: called `map(..).flatten()` on `Result`
+ --> $DIR/map_flatten_fixable.rs:30:42
+ |
+LL | let _: Result<_, &str> = (Ok(Ok(1))).map(|x| x).flatten();
+ | ^^^^^^^^^^^^^^^^^^^^
+ |
+help: try replacing `map` with `and_then`, and remove the `.flatten()`
+ |
+LL | let _: Result<_, &str> = (Ok(Ok(1))).and_then(|x| x);
+ | ~~~~~~~~~~~~~~~
+
++error: called `map(..).flatten()` on `Option`
++ --> $DIR/map_flatten_fixable.rs:59:10
++ |
++LL | .map(|_| {
++ | __________^
++LL | | // we need some newlines
++LL | | // so that the span is big enough
++LL | | // for a splitted output of the diagnostic
++... |
++LL | | })
++LL | | .flatten();
++ | |__________________^
++ |
++help: try replacing `map` with `and_then`
++ |
++LL ~ .and_then(|_| {
++LL + // we need some newlines
++LL + // so that the span is big enough
++ |
++help: and remove the `.flatten()`
++ |
++LL + Some("")
++LL + // whitespace beforehand is important as well
++LL ~ });
++ |
++
++error: aborting due to 8 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::match_ref_pats)]
++#![allow(dead_code, unused_variables, clippy::equatable_if_let, clippy::enum_variant_names)]
++
++fn ref_pats() {
++ {
++ let v = &Some(0);
++ match *v {
++ Some(v) => println!("{:?}", v),
++ None => println!("none"),
++ }
++ match v {
++ // This doesn't trigger; we have a different pattern.
++ &Some(v) => println!("some"),
++ other => println!("other"),
++ }
++ }
++ let tup = &(1, 2);
++ match tup {
++ &(v, 1) => println!("{}", v),
++ _ => println!("none"),
++ }
++ // Special case: using `&` both in expr and pats.
++ let w = Some(0);
++ match w {
++ Some(v) => println!("{:?}", v),
++ None => println!("none"),
++ }
++ // False positive: only wildcard pattern.
++ let w = Some(0);
++ #[allow(clippy::match_single_binding)]
++ match w {
++ _ => println!("none"),
++ }
++
++ let a = &Some(0);
++ if a.is_none() {
++ println!("none");
++ }
++
++ let b = Some(0);
++ if b.is_none() {
++ println!("none");
++ }
++}
++
++mod ice_3719 {
++ macro_rules! foo_variant(
++ ($idx:expr) => (Foo::get($idx).unwrap())
++ );
++
++ enum Foo {
++ A,
++ B,
++ }
++
++ impl Foo {
++ fn get(idx: u8) -> Option<&'static Self> {
++ match idx {
++ 0 => Some(&Foo::A),
++ 1 => Some(&Foo::B),
++ _ => None,
++ }
++ }
++ }
++
++ fn ice_3719() {
++ // ICE #3719
++ match foo_variant!(0) {
++ &Foo::A => println!("A"),
++ _ => println!("Wild"),
++ }
++ }
++}
++
++mod issue_7740 {
++ macro_rules! foobar_variant(
++ ($idx:expr) => (FooBar::get($idx).unwrap())
++ );
++
++ enum FooBar {
++ Foo,
++ Bar,
++ FooBar,
++ BarFoo,
++ }
++
++ impl FooBar {
++ fn get(idx: u8) -> Option<&'static Self> {
++ match idx {
++ 0 => Some(&FooBar::Foo),
++ 1 => Some(&FooBar::Bar),
++ 2 => Some(&FooBar::FooBar),
++ 3 => Some(&FooBar::BarFoo),
++ _ => None,
++ }
++ }
++ }
++
++ fn issue_7740() {
++ // Issue #7740
++ match *foobar_variant!(0) {
++ FooBar::Foo => println!("Foo"),
++ FooBar::Bar => println!("Bar"),
++ FooBar::FooBar => println!("FooBar"),
++ _ => println!("Wild"),
++ }
++
++ // This shouldn't trigger
++ if let &FooBar::BarFoo = foobar_variant!(3) {
++ println!("BarFoo");
++ } else {
++ println!("Wild");
++ }
++ }
++}
++
++fn main() {}
--- /dev/null
- #![allow(clippy::equatable_if_let, clippy::enum_variant_names)]
++// run-rustfix
+#![warn(clippy::match_ref_pats)]
++#![allow(dead_code, unused_variables, clippy::equatable_if_let, clippy::enum_variant_names)]
+
+fn ref_pats() {
+ {
+ let v = &Some(0);
+ match v {
+ &Some(v) => println!("{:?}", v),
+ &None => println!("none"),
+ }
+ match v {
+ // This doesn't trigger; we have a different pattern.
+ &Some(v) => println!("some"),
+ other => println!("other"),
+ }
+ }
+ let tup = &(1, 2);
+ match tup {
+ &(v, 1) => println!("{}", v),
+ _ => println!("none"),
+ }
+ // Special case: using `&` both in expr and pats.
+ let w = Some(0);
+ match &w {
+ &Some(v) => println!("{:?}", v),
+ &None => println!("none"),
+ }
+ // False positive: only wildcard pattern.
+ let w = Some(0);
+ #[allow(clippy::match_single_binding)]
+ match w {
+ _ => println!("none"),
+ }
+
+ let a = &Some(0);
+ if let &None = a {
+ println!("none");
+ }
+
+ let b = Some(0);
+ if let &None = &b {
+ println!("none");
+ }
+}
+
+mod ice_3719 {
+ macro_rules! foo_variant(
+ ($idx:expr) => (Foo::get($idx).unwrap())
+ );
+
+ enum Foo {
+ A,
+ B,
+ }
+
+ impl Foo {
+ fn get(idx: u8) -> Option<&'static Self> {
+ match idx {
+ 0 => Some(&Foo::A),
+ 1 => Some(&Foo::B),
+ _ => None,
+ }
+ }
+ }
+
+ fn ice_3719() {
+ // ICE #3719
+ match foo_variant!(0) {
+ &Foo::A => println!("A"),
+ _ => println!("Wild"),
+ }
+ }
+}
+
+mod issue_7740 {
+ macro_rules! foobar_variant(
+ ($idx:expr) => (FooBar::get($idx).unwrap())
+ );
+
+ enum FooBar {
+ Foo,
+ Bar,
+ FooBar,
+ BarFoo,
+ }
+
+ impl FooBar {
+ fn get(idx: u8) -> Option<&'static Self> {
+ match idx {
+ 0 => Some(&FooBar::Foo),
+ 1 => Some(&FooBar::Bar),
+ 2 => Some(&FooBar::FooBar),
+ 3 => Some(&FooBar::BarFoo),
+ _ => None,
+ }
+ }
+ }
+
+ fn issue_7740() {
+ // Issue #7740
+ match foobar_variant!(0) {
+ &FooBar::Foo => println!("Foo"),
+ &FooBar::Bar => println!("Bar"),
+ &FooBar::FooBar => println!("FooBar"),
+ _ => println!("Wild"),
+ }
+
+ // This shouldn't trigger
+ if let &FooBar::BarFoo = foobar_variant!(3) {
+ println!("BarFoo");
+ } else {
+ println!("Wild");
+ }
+ }
+}
+
+fn main() {}
--- /dev/null
- --> $DIR/match_ref_pats.rs:7:9
+error: you don't need to add `&` to all patterns
- --> $DIR/match_ref_pats.rs:24:5
++ --> $DIR/match_ref_pats.rs:8:9
+ |
+LL | / match v {
+LL | | &Some(v) => println!("{:?}", v),
+LL | | &None => println!("none"),
+LL | | }
+ | |_________^
+ |
+ = note: `-D clippy::match-ref-pats` implied by `-D warnings`
+help: instead of prefixing all patterns with `&`, you can dereference the expression
+ |
+LL ~ match *v {
+LL ~ Some(v) => println!("{:?}", v),
+LL ~ None => println!("none"),
+ |
+
+error: you don't need to add `&` to both the expression and the patterns
- --> $DIR/match_ref_pats.rs:36:12
++ --> $DIR/match_ref_pats.rs:25:5
+ |
+LL | / match &w {
+LL | | &Some(v) => println!("{:?}", v),
+LL | | &None => println!("none"),
+LL | | }
+ | |_____^
+ |
+help: try
+ |
+LL ~ match w {
+LL ~ Some(v) => println!("{:?}", v),
+LL ~ None => println!("none"),
+ |
+
+error: redundant pattern matching, consider using `is_none()`
- --> $DIR/match_ref_pats.rs:41:12
++ --> $DIR/match_ref_pats.rs:37:12
+ |
+LL | if let &None = a {
+ | -------^^^^^---- help: try this: `if a.is_none()`
+ |
+ = note: `-D clippy::redundant-pattern-matching` implied by `-D warnings`
+
+error: redundant pattern matching, consider using `is_none()`
- --> $DIR/match_ref_pats.rs:101:9
++ --> $DIR/match_ref_pats.rs:42:12
+ |
+LL | if let &None = &b {
+ | -------^^^^^----- help: try this: `if b.is_none()`
+
+error: you don't need to add `&` to all patterns
++ --> $DIR/match_ref_pats.rs:102:9
+ |
+LL | / match foobar_variant!(0) {
+LL | | &FooBar::Foo => println!("Foo"),
+LL | | &FooBar::Bar => println!("Bar"),
+LL | | &FooBar::FooBar => println!("FooBar"),
+LL | | _ => println!("Wild"),
+LL | | }
+ | |_________^
+ |
+help: instead of prefixing all patterns with `&`, you can dereference the expression
+ |
+LL ~ match *foobar_variant!(0) {
+LL ~ FooBar::Foo => println!("Foo"),
+LL ~ FooBar::Bar => println!("Bar"),
+LL ~ FooBar::FooBar => println!("FooBar"),
+ |
+
+error: aborting due to 5 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::match_str_case_mismatch)]
++#![allow(dead_code)]
++
++// Valid
++
++fn as_str_match() {
++ let var = "BAR";
++
++ match var.to_ascii_lowercase().as_str() {
++ "foo" => {},
++ "bar" => {},
++ _ => {},
++ }
++}
++
++fn non_alphabetic() {
++ let var = "~!@#$%^&*()-_=+FOO";
++
++ match var.to_ascii_lowercase().as_str() {
++ "1234567890" => {},
++ "~!@#$%^&*()-_=+foo" => {},
++ "\n\r\t\x7F" => {},
++ _ => {},
++ }
++}
++
++fn unicode_cased() {
++ let var = "ВОДЫ";
++
++ match var.to_lowercase().as_str() {
++ "水" => {},
++ "νερό" => {},
++ "воды" => {},
++ "물" => {},
++ _ => {},
++ }
++}
++
++fn titlecase() {
++ let var = "BarDz";
++
++ match var.to_lowercase().as_str() {
++ "foolj" => {},
++ "bardz" => {},
++ _ => {},
++ }
++}
++
++fn no_case_equivalent() {
++ let var = "barʁ";
++
++ match var.to_uppercase().as_str() {
++ "FOOɕ" => {},
++ "BARʁ" => {},
++ _ => {},
++ }
++}
++
++fn addrof_unary_match() {
++ let var = "BAR";
++
++ match &*var.to_ascii_lowercase() {
++ "foo" => {},
++ "bar" => {},
++ _ => {},
++ }
++}
++
++fn alternating_chain() {
++ let var = "BAR";
++
++ match &*var
++ .to_ascii_lowercase()
++ .to_uppercase()
++ .to_lowercase()
++ .to_ascii_uppercase()
++ {
++ "FOO" => {},
++ "BAR" => {},
++ _ => {},
++ }
++}
++
++fn unrelated_method() {
++ struct Item {
++ a: String,
++ }
++
++ impl Item {
++ #[allow(clippy::wrong_self_convention)]
++ fn to_lowercase(self) -> String {
++ self.a
++ }
++ }
++
++ let item = Item { a: String::from("BAR") };
++
++ match &*item.to_lowercase() {
++ "FOO" => {},
++ "BAR" => {},
++ _ => {},
++ }
++}
++
++// Invalid
++
++fn as_str_match_mismatch() {
++ let var = "BAR";
++
++ match var.to_ascii_lowercase().as_str() {
++ "foo" => {},
++ "bar" => {},
++ _ => {},
++ }
++}
++
++fn non_alphabetic_mismatch() {
++ let var = "~!@#$%^&*()-_=+FOO";
++
++ match var.to_ascii_lowercase().as_str() {
++ "1234567890" => {},
++ "~!@#$%^&*()-_=+foo" => {},
++ "\n\r\t\x7F" => {},
++ _ => {},
++ }
++}
++
++fn unicode_cased_mismatch() {
++ let var = "ВОДЫ";
++
++ match var.to_lowercase().as_str() {
++ "水" => {},
++ "νερό" => {},
++ "воды" => {},
++ "물" => {},
++ _ => {},
++ }
++}
++
++fn titlecase_mismatch() {
++ let var = "BarDz";
++
++ match var.to_lowercase().as_str() {
++ "foolj" => {},
++ "bardz" => {},
++ _ => {},
++ }
++}
++
++fn no_case_equivalent_mismatch() {
++ let var = "barʁ";
++
++ match var.to_uppercase().as_str() {
++ "FOOɕ" => {},
++ "BARʁ" => {},
++ _ => {},
++ }
++}
++
++fn addrof_unary_match_mismatch() {
++ let var = "BAR";
++
++ match &*var.to_ascii_lowercase() {
++ "foo" => {},
++ "bar" => {},
++ _ => {},
++ }
++}
++
++fn alternating_chain_mismatch() {
++ let var = "BAR";
++
++ match &*var
++ .to_ascii_lowercase()
++ .to_uppercase()
++ .to_lowercase()
++ .to_ascii_uppercase()
++ {
++ "FOO" => {},
++ "BAR" => {},
++ _ => {},
++ }
++}
++
++fn main() {}
--- /dev/null
++// run-rustfix
+#![warn(clippy::match_str_case_mismatch)]
++#![allow(dead_code)]
+
+// Valid
+
+fn as_str_match() {
+ let var = "BAR";
+
+ match var.to_ascii_lowercase().as_str() {
+ "foo" => {},
+ "bar" => {},
+ _ => {},
+ }
+}
+
+fn non_alphabetic() {
+ let var = "~!@#$%^&*()-_=+FOO";
+
+ match var.to_ascii_lowercase().as_str() {
+ "1234567890" => {},
+ "~!@#$%^&*()-_=+foo" => {},
+ "\n\r\t\x7F" => {},
+ _ => {},
+ }
+}
+
+fn unicode_cased() {
+ let var = "ВОДЫ";
+
+ match var.to_lowercase().as_str() {
+ "水" => {},
+ "νερό" => {},
+ "воды" => {},
+ "물" => {},
+ _ => {},
+ }
+}
+
+fn titlecase() {
+ let var = "BarDz";
+
+ match var.to_lowercase().as_str() {
+ "foolj" => {},
+ "bardz" => {},
+ _ => {},
+ }
+}
+
+fn no_case_equivalent() {
+ let var = "barʁ";
+
+ match var.to_uppercase().as_str() {
+ "FOOɕ" => {},
+ "BARʁ" => {},
+ _ => {},
+ }
+}
+
+fn addrof_unary_match() {
+ let var = "BAR";
+
+ match &*var.to_ascii_lowercase() {
+ "foo" => {},
+ "bar" => {},
+ _ => {},
+ }
+}
+
+fn alternating_chain() {
+ let var = "BAR";
+
+ match &*var
+ .to_ascii_lowercase()
+ .to_uppercase()
+ .to_lowercase()
+ .to_ascii_uppercase()
+ {
+ "FOO" => {},
+ "BAR" => {},
+ _ => {},
+ }
+}
+
+fn unrelated_method() {
+ struct Item {
+ a: String,
+ }
+
+ impl Item {
+ #[allow(clippy::wrong_self_convention)]
+ fn to_lowercase(self) -> String {
+ self.a
+ }
+ }
+
+ let item = Item { a: String::from("BAR") };
+
+ match &*item.to_lowercase() {
+ "FOO" => {},
+ "BAR" => {},
+ _ => {},
+ }
+}
+
+// Invalid
+
+fn as_str_match_mismatch() {
+ let var = "BAR";
+
+ match var.to_ascii_lowercase().as_str() {
+ "foo" => {},
+ "Bar" => {},
+ _ => {},
+ }
+}
+
+fn non_alphabetic_mismatch() {
+ let var = "~!@#$%^&*()-_=+FOO";
+
+ match var.to_ascii_lowercase().as_str() {
+ "1234567890" => {},
+ "~!@#$%^&*()-_=+Foo" => {},
+ "\n\r\t\x7F" => {},
+ _ => {},
+ }
+}
+
+fn unicode_cased_mismatch() {
+ let var = "ВОДЫ";
+
+ match var.to_lowercase().as_str() {
+ "水" => {},
+ "νερό" => {},
+ "Воды" => {},
+ "물" => {},
+ _ => {},
+ }
+}
+
+fn titlecase_mismatch() {
+ let var = "BarDz";
+
+ match var.to_lowercase().as_str() {
+ "foolj" => {},
+ "barDz" => {},
+ _ => {},
+ }
+}
+
+fn no_case_equivalent_mismatch() {
+ let var = "barʁ";
+
+ match var.to_uppercase().as_str() {
+ "FOOɕ" => {},
+ "bARʁ" => {},
+ _ => {},
+ }
+}
+
+fn addrof_unary_match_mismatch() {
+ let var = "BAR";
+
+ match &*var.to_ascii_lowercase() {
+ "foo" => {},
+ "Bar" => {},
+ _ => {},
+ }
+}
+
+fn alternating_chain_mismatch() {
+ let var = "BAR";
+
+ match &*var
+ .to_ascii_lowercase()
+ .to_uppercase()
+ .to_lowercase()
+ .to_ascii_uppercase()
+ {
+ "FOO" => {},
+ "bAR" => {},
+ _ => {},
+ }
+}
+
+fn main() {}
--- /dev/null
- --> $DIR/match_str_case_mismatch.rs:111:9
+error: this `match` arm has a differing case than its expression
- --> $DIR/match_str_case_mismatch.rs:121:9
++ --> $DIR/match_str_case_mismatch.rs:113:9
+ |
+LL | "Bar" => {},
+ | ^^^^^
+ |
+ = note: `-D clippy::match-str-case-mismatch` implied by `-D warnings`
+help: consider changing the case of this arm to respect `to_ascii_lowercase`
+ |
+LL | "bar" => {},
+ | ~~~~~
+
+error: this `match` arm has a differing case than its expression
- --> $DIR/match_str_case_mismatch.rs:133:9
++ --> $DIR/match_str_case_mismatch.rs:123:9
+ |
+LL | "~!@#$%^&*()-_=+Foo" => {},
+ | ^^^^^^^^^^^^^^^^^^^^
+ |
+help: consider changing the case of this arm to respect `to_ascii_lowercase`
+ |
+LL | "~!@#$%^&*()-_=+foo" => {},
+ | ~~~~~~~~~~~~~~~~~~~~
+
+error: this `match` arm has a differing case than its expression
- --> $DIR/match_str_case_mismatch.rs:144:9
++ --> $DIR/match_str_case_mismatch.rs:135:9
+ |
+LL | "Воды" => {},
+ | ^^^^^^
+ |
+help: consider changing the case of this arm to respect `to_lowercase`
+ |
+LL | "воды" => {},
+ | ~~~~~~
+
+error: this `match` arm has a differing case than its expression
- --> $DIR/match_str_case_mismatch.rs:154:9
++ --> $DIR/match_str_case_mismatch.rs:146:9
+ |
+LL | "barDz" => {},
+ | ^^^^^^
+ |
+help: consider changing the case of this arm to respect `to_lowercase`
+ |
+LL | "bardz" => {},
+ | ~~~~~~
+
+error: this `match` arm has a differing case than its expression
- --> $DIR/match_str_case_mismatch.rs:164:9
++ --> $DIR/match_str_case_mismatch.rs:156:9
+ |
+LL | "bARʁ" => {},
+ | ^^^^^^
+ |
+help: consider changing the case of this arm to respect `to_uppercase`
+ |
+LL | "BARʁ" => {},
+ | ~~~~~~
+
+error: this `match` arm has a differing case than its expression
- --> $DIR/match_str_case_mismatch.rs:179:9
++ --> $DIR/match_str_case_mismatch.rs:166:9
+ |
+LL | "Bar" => {},
+ | ^^^^^
+ |
+help: consider changing the case of this arm to respect `to_ascii_lowercase`
+ |
+LL | "bar" => {},
+ | ~~~~~
+
+error: this `match` arm has a differing case than its expression
++ --> $DIR/match_str_case_mismatch.rs:181:9
+ |
+LL | "bAR" => {},
+ | ^^^^^
+ |
+help: consider changing the case of this arm to respect `to_ascii_uppercase`
+ |
+LL | "BAR" => {},
+ | ~~~~~
+
+error: aborting due to 7 previous errors
+
--- /dev/null
--- /dev/null
++#![warn(clippy::mismatching_type_param_order)]
++#![allow(clippy::blacklisted_name)]
++
++fn main() {
++ struct Foo<A, B> {
++ x: A,
++ y: B,
++ }
++
++ // lint on both params
++ impl<B, A> Foo<B, A> {}
++
++ // lint on the 2nd param
++ impl<C, A> Foo<C, A> {}
++
++ // should not lint
++ impl<A, B> Foo<A, B> {}
++
++ struct FooLifetime<'l, 'm, A, B> {
++ x: &'l A,
++ y: &'m B,
++ }
++
++ // should not lint on lifetimes
++ impl<'m, 'l, B, A> FooLifetime<'m, 'l, B, A> {}
++
++ struct Bar {
++ x: i32,
++ }
++
++ // should not lint
++ impl Bar {}
++
++ // also works for enums
++ enum FooEnum<A, B, C> {
++ X(A),
++ Y(B),
++ Z(C),
++ }
++
++ impl<C, A, B> FooEnum<C, A, B> {}
++
++ // also works for unions
++ union FooUnion<A: Copy, B>
++ where
++ B: Copy,
++ {
++ x: A,
++ y: B,
++ }
++
++ impl<B: Copy, A> FooUnion<B, A> where A: Copy {}
++
++ impl<A, B> FooUnion<A, B>
++ where
++ A: Copy,
++ B: Copy,
++ {
++ }
++}
--- /dev/null
--- /dev/null
++error: `Foo` has a similarly named generic type parameter `B` in its declaration, but in a different order
++ --> $DIR/mismatching_type_param_order.rs:11:20
++ |
++LL | impl<B, A> Foo<B, A> {}
++ | ^
++ |
++ = note: `-D clippy::mismatching-type-param-order` implied by `-D warnings`
++ = help: try `A`, or a name that does not conflict with `Foo`'s generic params
++
++error: `Foo` has a similarly named generic type parameter `A` in its declaration, but in a different order
++ --> $DIR/mismatching_type_param_order.rs:11:23
++ |
++LL | impl<B, A> Foo<B, A> {}
++ | ^
++ |
++ = help: try `B`, or a name that does not conflict with `Foo`'s generic params
++
++error: `Foo` has a similarly named generic type parameter `A` in its declaration, but in a different order
++ --> $DIR/mismatching_type_param_order.rs:14:23
++ |
++LL | impl<C, A> Foo<C, A> {}
++ | ^
++ |
++ = help: try `B`, or a name that does not conflict with `Foo`'s generic params
++
++error: `FooLifetime` has a similarly named generic type parameter `B` in its declaration, but in a different order
++ --> $DIR/mismatching_type_param_order.rs:25:44
++ |
++LL | impl<'m, 'l, B, A> FooLifetime<'m, 'l, B, A> {}
++ | ^
++ |
++ = help: try `A`, or a name that does not conflict with `FooLifetime`'s generic params
++
++error: `FooLifetime` has a similarly named generic type parameter `A` in its declaration, but in a different order
++ --> $DIR/mismatching_type_param_order.rs:25:47
++ |
++LL | impl<'m, 'l, B, A> FooLifetime<'m, 'l, B, A> {}
++ | ^
++ |
++ = help: try `B`, or a name that does not conflict with `FooLifetime`'s generic params
++
++error: `FooEnum` has a similarly named generic type parameter `C` in its declaration, but in a different order
++ --> $DIR/mismatching_type_param_order.rs:41:27
++ |
++LL | impl<C, A, B> FooEnum<C, A, B> {}
++ | ^
++ |
++ = help: try `A`, or a name that does not conflict with `FooEnum`'s generic params
++
++error: `FooEnum` has a similarly named generic type parameter `A` in its declaration, but in a different order
++ --> $DIR/mismatching_type_param_order.rs:41:30
++ |
++LL | impl<C, A, B> FooEnum<C, A, B> {}
++ | ^
++ |
++ = help: try `B`, or a name that does not conflict with `FooEnum`'s generic params
++
++error: `FooEnum` has a similarly named generic type parameter `B` in its declaration, but in a different order
++ --> $DIR/mismatching_type_param_order.rs:41:33
++ |
++LL | impl<C, A, B> FooEnum<C, A, B> {}
++ | ^
++ |
++ = help: try `C`, or a name that does not conflict with `FooEnum`'s generic params
++
++error: `FooUnion` has a similarly named generic type parameter `B` in its declaration, but in a different order
++ --> $DIR/mismatching_type_param_order.rs:52:31
++ |
++LL | impl<B: Copy, A> FooUnion<B, A> where A: Copy {}
++ | ^
++ |
++ = help: try `A`, or a name that does not conflict with `FooUnion`'s generic params
++
++error: `FooUnion` has a similarly named generic type parameter `A` in its declaration, but in a different order
++ --> $DIR/mismatching_type_param_order.rs:52:34
++ |
++LL | impl<B: Copy, A> FooUnion<B, A> where A: Copy {}
++ | ^
++ |
++ = help: try `B`, or a name that does not conflict with `FooUnion`'s generic params
++
++error: aborting due to 10 previous errors
++
--- /dev/null
- #![allow(clippy::no_effect, clippy::unnecessary_operation)]
+#![warn(clippy::modulo_one)]
++#![allow(clippy::no_effect, clippy::unnecessary_operation, clippy::identity_op)]
+
+static STATIC_ONE: usize = 2 - 1;
+static STATIC_NEG_ONE: i64 = 1 - 2;
+
+fn main() {
+ 10 % 1;
+ 10 % -1;
+ 10 % 2;
+ i32::MIN % (-1); // also caught by rustc
+
+ const ONE: u32 = 1 * 1;
+ const NEG_ONE: i64 = 1 - 2;
+ const INT_MIN: i64 = i64::MIN;
+
+ 2 % ONE;
+ 5 % STATIC_ONE; // NOT caught by lint
+ 2 % NEG_ONE;
+ 5 % STATIC_NEG_ONE; // NOT caught by lint
+ INT_MIN % NEG_ONE; // also caught by rustc
+ INT_MIN % STATIC_NEG_ONE; // ONLY caught by rustc
+}
--- /dev/null
- error: the operation is ineffective. Consider reducing it to `1`
- --> $DIR/modulo_one.rs:13:22
- |
- LL | const ONE: u32 = 1 * 1;
- | ^^^^^
- |
- = note: `-D clippy::identity-op` implied by `-D warnings`
-
+error: this operation will panic at runtime
+ --> $DIR/modulo_one.rs:11:5
+ |
+LL | i32::MIN % (-1); // also caught by rustc
+ | ^^^^^^^^^^^^^^^ attempt to compute the remainder of `i32::MIN % -1_i32`, which would overflow
+ |
+ = note: `#[deny(unconditional_panic)]` on by default
+
+error: this operation will panic at runtime
+ --> $DIR/modulo_one.rs:21:5
+ |
+LL | INT_MIN % NEG_ONE; // also caught by rustc
+ | ^^^^^^^^^^^^^^^^^ attempt to compute the remainder of `i64::MIN % -1_i64`, which would overflow
+
+error: this operation will panic at runtime
+ --> $DIR/modulo_one.rs:22:5
+ |
+LL | INT_MIN % STATIC_NEG_ONE; // ONLY caught by rustc
+ | ^^^^^^^^^^^^^^^^^^^^^^^^ attempt to compute the remainder of `i64::MIN % -1_i64`, which would overflow
+
+error: any number modulo 1 will be 0
+ --> $DIR/modulo_one.rs:8:5
+ |
+LL | 10 % 1;
+ | ^^^^^^
+ |
+ = note: `-D clippy::modulo-one` implied by `-D warnings`
+
+error: any number modulo -1 will panic/overflow or result in 0
+ --> $DIR/modulo_one.rs:9:5
+ |
+LL | 10 % -1;
+ | ^^^^^^^
+
+error: any number modulo -1 will panic/overflow or result in 0
+ --> $DIR/modulo_one.rs:11:5
+ |
+LL | i32::MIN % (-1); // also caught by rustc
+ | ^^^^^^^^^^^^^^^
+
- error: aborting due to 10 previous errors
+error: any number modulo 1 will be 0
+ --> $DIR/modulo_one.rs:17:5
+ |
+LL | 2 % ONE;
+ | ^^^^^^^
+
+error: any number modulo -1 will panic/overflow or result in 0
+ --> $DIR/modulo_one.rs:19:5
+ |
+LL | 2 % NEG_ONE;
+ | ^^^^^^^^^^^
+
+error: any number modulo -1 will panic/overflow or result in 0
+ --> $DIR/modulo_one.rs:21:5
+ |
+LL | INT_MIN % NEG_ONE; // also caught by rustc
+ | ^^^^^^^^^^^^^^^^^
+
++error: aborting due to 9 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![feature(let_chains)]
++#![allow(
++ unused,
++ clippy::assign_op_pattern,
++ clippy::blocks_in_if_conditions,
++ clippy::let_and_return,
++ clippy::let_unit_value,
++ clippy::nonminimal_bool
++)]
++
++use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
++use std::rc::Rc;
++
++struct SignificantDrop;
++impl std::ops::Drop for SignificantDrop {
++ fn drop(&mut self) {
++ println!("dropped");
++ }
++}
++
++fn simple() {
++
++ let a = "zero";
++
++
++
++ let b = 1;
++ let c = 2;
++
++
++ let d: usize = 1;
++
++
++ let e = format!("{}", d);
++}
++
++fn main() {
++
++ let n = 1;
++ let a = match n {
++ 1 => "one",
++ _ => {
++ "two"
++ },
++ };
++
++
++ let b = if n == 3 {
++ "four"
++ } else {
++ "five"
++ };
++
++
++ let d = if true {
++ let temp = 5;
++ temp
++ } else {
++ 15
++ };
++
++
++ let e = if true {
++ format!("{} {}", a, b)
++ } else {
++ format!("{}", n)
++ };
++
++
++ let f = match 1 {
++ 1 => "three",
++ _ => return,
++ }; // has semi
++
++
++ let g: usize = if true {
++ 5
++ } else {
++ panic!();
++ };
++
++ // Drop order only matters if both are significant
++
++ let y = SignificantDrop;
++ let x = 1;
++
++
++ let y = 1;
++ let x = SignificantDrop;
++
++
++ // types that should be considered insignificant
++ let y = 1;
++ let y = "2";
++ let y = String::new();
++ let y = vec![3.0];
++ let y = HashMap::<usize, usize>::new();
++ let y = BTreeMap::<usize, usize>::new();
++ let y = HashSet::<usize>::new();
++ let y = BTreeSet::<usize>::new();
++ let y = Box::new(4);
++ let x = SignificantDrop;
++}
++
++async fn in_async() -> &'static str {
++ async fn f() -> &'static str {
++ "one"
++ }
++
++
++ let n = 1;
++ let a = match n {
++ 1 => f().await,
++ _ => {
++ "two"
++ },
++ };
++
++ a
++}
++
++const fn in_const() -> &'static str {
++ const fn f() -> &'static str {
++ "one"
++ }
++
++
++ let n = 1;
++ let a = match n {
++ 1 => f(),
++ _ => {
++ "two"
++ },
++ };
++
++ a
++}
++
++fn does_not_lint() {
++ let z;
++ if false {
++ z = 1;
++ }
++
++ let x;
++ let y;
++ if true {
++ x = 1;
++ } else {
++ y = 1;
++ }
++
++ let mut x;
++ if true {
++ x = 5;
++ x = 10 / x;
++ } else {
++ x = 2;
++ }
++
++ let x;
++ let _ = match 1 {
++ 1 => x = 10,
++ _ => x = 20,
++ };
++
++ // using tuples would be possible, but not always preferable
++ let x;
++ let y;
++ if true {
++ x = 1;
++ y = 2;
++ } else {
++ x = 3;
++ y = 4;
++ }
++
++ // could match with a smarter heuristic to avoid multiple assignments
++ let x;
++ if true {
++ let mut y = 5;
++ y = 6;
++ x = y;
++ } else {
++ x = 2;
++ }
++
++ let (x, y);
++ if true {
++ x = 1;
++ } else {
++ x = 2;
++ }
++ y = 3;
++
++ macro_rules! assign {
++ ($i:ident) => {
++ $i = 1;
++ };
++ }
++ let x;
++ assign!(x);
++
++ let x;
++ if true {
++ assign!(x);
++ } else {
++ x = 2;
++ }
++
++ macro_rules! in_macro {
++ () => {
++ let x;
++ x = 1;
++
++ let x;
++ if true {
++ x = 1;
++ } else {
++ x = 2;
++ }
++ };
++ }
++ in_macro!();
++
++ // ignore if-lets - https://github.com/rust-lang/rust-clippy/issues/8613
++ let x;
++ if let Some(n) = Some("v") {
++ x = 1;
++ } else {
++ x = 2;
++ }
++
++ let x;
++ if true && let Some(n) = Some("let chains too") {
++ x = 1;
++ } else {
++ x = 2;
++ }
++
++ // ignore mut bindings
++ // https://github.com/shepmaster/twox-hash/blob/b169c16d86eb8ea4a296b0acb9d00ca7e3c3005f/src/sixty_four.rs#L88-L93
++ // https://github.com/dtolnay/thiserror/blob/21c26903e29cb92ba1a7ff11e82ae2001646b60d/tests/test_generics.rs#L91-L100
++ let mut x: usize;
++ x = 1;
++ x = 2;
++ x = 3;
++
++ // should not move the declaration if `x` has a significant drop, and there
++ // is another binding with a significant drop between it and the first usage
++ let x;
++ let y = SignificantDrop;
++ x = SignificantDrop;
++}
++
++#[rustfmt::skip]
++fn issue8911() -> u32 {
++ let x;
++ match 1 {
++ _ if { x = 1; false } => return 1,
++ _ => return 2,
++ }
++
++ let x;
++ if { x = 1; true } {
++ return 1;
++ } else {
++ return 2;
++ }
++
++ 3
++}
--- /dev/null
- #![allow(unused, clippy::nonminimal_bool, clippy::let_unit_value)]
++// run-rustfix
+#![feature(let_chains)]
++#![allow(
++ unused,
++ clippy::assign_op_pattern,
++ clippy::blocks_in_if_conditions,
++ clippy::let_and_return,
++ clippy::let_unit_value,
++ clippy::nonminimal_bool
++)]
+
+use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
+use std::rc::Rc;
+
+struct SignificantDrop;
+impl std::ops::Drop for SignificantDrop {
+ fn drop(&mut self) {
+ println!("dropped");
+ }
+}
+
++fn simple() {
++ let a;
++ a = "zero";
++
++ let b;
++ let c;
++ b = 1;
++ c = 2;
++
++ let d: usize;
++ d = 1;
++
++ let e;
++ e = format!("{}", d);
++}
++
+fn main() {
+ let a;
+ let n = 1;
+ match n {
+ 1 => a = "one",
+ _ => {
+ a = "two";
+ },
+ }
+
+ let b;
+ if n == 3 {
+ b = "four";
+ } else {
+ b = "five"
+ }
+
+ let d;
+ if true {
+ let temp = 5;
+ d = temp;
+ } else {
+ d = 15;
+ }
+
+ let e;
+ if true {
+ e = format!("{} {}", a, b);
+ } else {
+ e = format!("{}", n);
+ }
+
+ let f;
+ match 1 {
+ 1 => f = "three",
+ _ => return,
+ }; // has semi
+
+ let g: usize;
+ if true {
+ g = 5;
+ } else {
+ panic!();
+ }
+
+ // Drop order only matters if both are significant
+ let x;
+ let y = SignificantDrop;
+ x = 1;
+
+ let x;
+ let y = 1;
+ x = SignificantDrop;
+
+ let x;
+ // types that should be considered insignificant
+ let y = 1;
+ let y = "2";
+ let y = String::new();
+ let y = vec![3.0];
+ let y = HashMap::<usize, usize>::new();
+ let y = BTreeMap::<usize, usize>::new();
+ let y = HashSet::<usize>::new();
+ let y = BTreeSet::<usize>::new();
+ let y = Box::new(4);
+ x = SignificantDrop;
+}
+
+async fn in_async() -> &'static str {
+ async fn f() -> &'static str {
+ "one"
+ }
+
+ let a;
+ let n = 1;
+ match n {
+ 1 => a = f().await,
+ _ => {
+ a = "two";
+ },
+ }
+
+ a
+}
+
+const fn in_const() -> &'static str {
+ const fn f() -> &'static str {
+ "one"
+ }
+
+ let a;
+ let n = 1;
+ match n {
+ 1 => a = f(),
+ _ => {
+ a = "two";
+ },
+ }
+
+ a
+}
+
+fn does_not_lint() {
+ let z;
+ if false {
+ z = 1;
+ }
+
+ let x;
+ let y;
+ if true {
+ x = 1;
+ } else {
+ y = 1;
+ }
+
+ let mut x;
+ if true {
+ x = 5;
+ x = 10 / x;
+ } else {
+ x = 2;
+ }
+
+ let x;
+ let _ = match 1 {
+ 1 => x = 10,
+ _ => x = 20,
+ };
+
+ // using tuples would be possible, but not always preferable
+ let x;
+ let y;
+ if true {
+ x = 1;
+ y = 2;
+ } else {
+ x = 3;
+ y = 4;
+ }
+
+ // could match with a smarter heuristic to avoid multiple assignments
+ let x;
+ if true {
+ let mut y = 5;
+ y = 6;
+ x = y;
+ } else {
+ x = 2;
+ }
+
+ let (x, y);
+ if true {
+ x = 1;
+ } else {
+ x = 2;
+ }
+ y = 3;
+
+ macro_rules! assign {
+ ($i:ident) => {
+ $i = 1;
+ };
+ }
+ let x;
+ assign!(x);
+
+ let x;
+ if true {
+ assign!(x);
+ } else {
+ x = 2;
+ }
+
+ macro_rules! in_macro {
+ () => {
+ let x;
+ x = 1;
+
+ let x;
+ if true {
+ x = 1;
+ } else {
+ x = 2;
+ }
+ };
+ }
+ in_macro!();
+
+ // ignore if-lets - https://github.com/rust-lang/rust-clippy/issues/8613
+ let x;
+ if let Some(n) = Some("v") {
+ x = 1;
+ } else {
+ x = 2;
+ }
+
+ let x;
+ if true && let Some(n) = Some("let chains too") {
+ x = 1;
+ } else {
+ x = 2;
+ }
+
+ // ignore mut bindings
+ // https://github.com/shepmaster/twox-hash/blob/b169c16d86eb8ea4a296b0acb9d00ca7e3c3005f/src/sixty_four.rs#L88-L93
+ // https://github.com/dtolnay/thiserror/blob/21c26903e29cb92ba1a7ff11e82ae2001646b60d/tests/test_generics.rs#L91-L100
+ let mut x: usize;
+ x = 1;
+ x = 2;
+ x = 3;
+
+ // should not move the declaration if `x` has a significant drop, and there
+ // is another binding with a significant drop between it and the first usage
+ let x;
+ let y = SignificantDrop;
+ x = SignificantDrop;
+}
++
++#[rustfmt::skip]
++fn issue8911() -> u32 {
++ let x;
++ match 1 {
++ _ if { x = 1; false } => return 1,
++ _ => return 2,
++ }
++
++ let x;
++ if { x = 1; true } {
++ return 1;
++ } else {
++ return 2;
++ }
++
++ 3
++}
--- /dev/null
- --> $DIR/needless_late_init.rs:15:5
+error: unneeded late initialization
- | ^^^^^^
++ --> $DIR/needless_late_init.rs:23:5
+ |
+LL | let a;
- --> $DIR/needless_late_init.rs:24:5
++ | ^^^^^^ created here
++LL | a = "zero";
++ | ^^^^^^^^^^ initialised here
+ |
+ = note: `-D clippy::needless-late-init` implied by `-D warnings`
+help: declare `a` here
+ |
++LL | let a = "zero";
++ | ~~~~~
++
++error: unneeded late initialization
++ --> $DIR/needless_late_init.rs:26:5
++ |
++LL | let b;
++ | ^^^^^^ created here
++LL | let c;
++LL | b = 1;
++ | ^^^^^ initialised here
++ |
++help: declare `b` here
++ |
++LL | let b = 1;
++ | ~~~~~
++
++error: unneeded late initialization
++ --> $DIR/needless_late_init.rs:27:5
++ |
++LL | let c;
++ | ^^^^^^ created here
++LL | b = 1;
++LL | c = 2;
++ | ^^^^^ initialised here
++ |
++help: declare `c` here
++ |
++LL | let c = 2;
++ | ~~~~~
++
++error: unneeded late initialization
++ --> $DIR/needless_late_init.rs:31:5
++ |
++LL | let d: usize;
++ | ^^^^^^^^^^^^^ created here
++LL | d = 1;
++ | ^^^^^ initialised here
++ |
++help: declare `d` here
++ |
++LL | let d: usize = 1;
++ | ~~~~~~~~~~~~
++
++error: unneeded late initialization
++ --> $DIR/needless_late_init.rs:34:5
++ |
++LL | let e;
++ | ^^^^^^ created here
++LL | e = format!("{}", d);
++ | ^^^^^^^^^^^^^^^^^^^^ initialised here
++ |
++help: declare `e` here
++ |
++LL | let e = format!("{}", d);
++ | ~~~~~
++
++error: unneeded late initialization
++ --> $DIR/needless_late_init.rs:39:5
++ |
++LL | let a;
++ | ^^^^^^
++ |
++help: declare `a` here
++ |
+LL | let a = match n {
+ | +++++++
+help: remove the assignments from the `match` arms
+ |
+LL ~ 1 => "one",
+LL | _ => {
+LL ~ "two"
+ |
+help: add a semicolon after the `match` expression
+ |
+LL | };
+ | +
+
+error: unneeded late initialization
- --> $DIR/needless_late_init.rs:31:5
++ --> $DIR/needless_late_init.rs:48:5
+ |
+LL | let b;
+ | ^^^^^^
+ |
+help: declare `b` here
+ |
+LL | let b = if n == 3 {
+ | +++++++
+help: remove the assignments from the branches
+ |
+LL ~ "four"
+LL | } else {
+LL ~ "five"
+ |
+help: add a semicolon after the `if` expression
+ |
+LL | };
+ | +
+
+error: unneeded late initialization
- --> $DIR/needless_late_init.rs:39:5
++ --> $DIR/needless_late_init.rs:55:5
+ |
+LL | let d;
+ | ^^^^^^
+ |
+help: declare `d` here
+ |
+LL | let d = if true {
+ | +++++++
+help: remove the assignments from the branches
+ |
+LL ~ temp
+LL | } else {
+LL ~ 15
+ |
+help: add a semicolon after the `if` expression
+ |
+LL | };
+ | +
+
+error: unneeded late initialization
- --> $DIR/needless_late_init.rs:46:5
++ --> $DIR/needless_late_init.rs:63:5
+ |
+LL | let e;
+ | ^^^^^^
+ |
+help: declare `e` here
+ |
+LL | let e = if true {
+ | +++++++
+help: remove the assignments from the branches
+ |
+LL ~ format!("{} {}", a, b)
+LL | } else {
+LL ~ format!("{}", n)
+ |
+help: add a semicolon after the `if` expression
+ |
+LL | };
+ | +
+
+error: unneeded late initialization
- --> $DIR/needless_late_init.rs:52:5
++ --> $DIR/needless_late_init.rs:70:5
+ |
+LL | let f;
+ | ^^^^^^
+ |
+help: declare `f` here
+ |
+LL | let f = match 1 {
+ | +++++++
+help: remove the assignments from the `match` arms
+ |
+LL - 1 => f = "three",
+LL + 1 => "three",
+ |
+
+error: unneeded late initialization
- --> $DIR/needless_late_init.rs:60:5
++ --> $DIR/needless_late_init.rs:76:5
+ |
+LL | let g: usize;
+ | ^^^^^^^^^^^^^
+ |
+help: declare `g` here
+ |
+LL | let g: usize = if true {
+ | ++++++++++++++
+help: remove the assignments from the branches
+ |
+LL - g = 5;
+LL + 5
+ |
+help: add a semicolon after the `if` expression
+ |
+LL | };
+ | +
+
+error: unneeded late initialization
- --> $DIR/needless_late_init.rs:64:5
++ --> $DIR/needless_late_init.rs:84:5
+ |
+LL | let x;
+ | ^^^^^^ created here
+LL | let y = SignificantDrop;
+LL | x = 1;
+ | ^^^^^ initialised here
+ |
+help: declare `x` here
+ |
+LL | let x = 1;
+ | ~~~~~
+
+error: unneeded late initialization
- --> $DIR/needless_late_init.rs:68:5
++ --> $DIR/needless_late_init.rs:88:5
+ |
+LL | let x;
+ | ^^^^^^ created here
+LL | let y = 1;
+LL | x = SignificantDrop;
+ | ^^^^^^^^^^^^^^^^^^^ initialised here
+ |
+help: declare `x` here
+ |
+LL | let x = SignificantDrop;
+ | ~~~~~
+
+error: unneeded late initialization
- --> $DIR/needless_late_init.rs:87:5
++ --> $DIR/needless_late_init.rs:92:5
+ |
+LL | let x;
+ | ^^^^^^ created here
+...
+LL | x = SignificantDrop;
+ | ^^^^^^^^^^^^^^^^^^^ initialised here
+ |
+help: declare `x` here
+ |
+LL | let x = SignificantDrop;
+ | ~~~~~
+
+error: unneeded late initialization
- --> $DIR/needless_late_init.rs:104:5
++ --> $DIR/needless_late_init.rs:111:5
+ |
+LL | let a;
+ | ^^^^^^
+ |
+help: declare `a` here
+ |
+LL | let a = match n {
+ | +++++++
+help: remove the assignments from the `match` arms
+ |
+LL ~ 1 => f().await,
+LL | _ => {
+LL ~ "two"
+ |
+help: add a semicolon after the `match` expression
+ |
+LL | };
+ | +
+
+error: unneeded late initialization
- error: aborting due to 11 previous errors
++ --> $DIR/needless_late_init.rs:128:5
+ |
+LL | let a;
+ | ^^^^^^
+ |
+help: declare `a` here
+ |
+LL | let a = match n {
+ | +++++++
+help: remove the assignments from the `match` arms
+ |
+LL ~ 1 => f(),
+LL | _ => {
+LL ~ "two"
+ |
+help: add a semicolon after the `match` expression
+ |
+LL | };
+ | +
+
++error: aborting due to 16 previous errors
+
--- /dev/null
- dyn_drop
+#![warn(clippy::needless_lifetimes)]
+#![allow(
+ dead_code,
+ clippy::boxed_local,
+ clippy::needless_pass_by_value,
+ clippy::unnecessary_wraps,
++ dyn_drop,
++ clippy::get_first
+)]
+
+fn distinct_lifetimes<'a, 'b>(_x: &'a u8, _y: &'b u8, _z: u8) {}
+
+fn distinct_and_static<'a, 'b>(_x: &'a u8, _y: &'b u8, _z: &'static u8) {}
+
+// No error; same lifetime on two params.
+fn same_lifetime_on_input<'a>(_x: &'a u8, _y: &'a u8) {}
+
+// No error; static involved.
+fn only_static_on_input(_x: &u8, _y: &u8, _z: &'static u8) {}
+
+fn mut_and_static_input(_x: &mut u8, _y: &'static str) {}
+
+fn in_and_out<'a>(x: &'a u8, _y: u8) -> &'a u8 {
+ x
+}
+
+// No error; multiple input refs.
+fn multiple_in_and_out_1<'a>(x: &'a u8, _y: &'a u8) -> &'a u8 {
+ x
+}
+
+// No error; multiple input refs.
+fn multiple_in_and_out_2<'a, 'b>(x: &'a u8, _y: &'b u8) -> &'a u8 {
+ x
+}
+
+// No error; multiple input refs
+async fn func<'a>(args: &[&'a str]) -> Option<&'a str> {
+ args.get(0).cloned()
+}
+
+// No error; static involved.
+fn in_static_and_out<'a>(x: &'a u8, _y: &'static u8) -> &'a u8 {
+ x
+}
+
+// No error.
+fn deep_reference_1<'a, 'b>(x: &'a u8, _y: &'b u8) -> Result<&'a u8, ()> {
+ Ok(x)
+}
+
+// No error; two input refs.
+fn deep_reference_2<'a>(x: Result<&'a u8, &'a u8>) -> &'a u8 {
+ x.unwrap()
+}
+
+fn deep_reference_3<'a>(x: &'a u8, _y: u8) -> Result<&'a u8, ()> {
+ Ok(x)
+}
+
+// Where-clause, but without lifetimes.
+fn where_clause_without_lt<'a, T>(x: &'a u8, _y: u8) -> Result<&'a u8, ()>
+where
+ T: Copy,
+{
+ Ok(x)
+}
+
+type Ref<'r> = &'r u8;
+
+// No error; same lifetime on two params.
+fn lifetime_param_1<'a>(_x: Ref<'a>, _y: &'a u8) {}
+
+fn lifetime_param_2<'a, 'b>(_x: Ref<'a>, _y: &'b u8) {}
+
+// No error; bounded lifetime.
+fn lifetime_param_3<'a, 'b: 'a>(_x: Ref<'a>, _y: &'b u8) {}
+
+// No error; bounded lifetime.
+fn lifetime_param_4<'a, 'b>(_x: Ref<'a>, _y: &'b u8)
+where
+ 'b: 'a,
+{
+}
+
+struct Lt<'a, I: 'static> {
+ x: &'a I,
+}
+
+// No error; fn bound references `'a`.
+fn fn_bound<'a, F, I>(_m: Lt<'a, I>, _f: F) -> Lt<'a, I>
+where
+ F: Fn(Lt<'a, I>) -> Lt<'a, I>,
+{
+ unreachable!()
+}
+
+fn fn_bound_2<'a, F, I>(_m: Lt<'a, I>, _f: F) -> Lt<'a, I>
+where
+ for<'x> F: Fn(Lt<'x, I>) -> Lt<'x, I>,
+{
+ unreachable!()
+}
+
+// No error; see below.
+fn fn_bound_3<'a, F: FnOnce(&'a i32)>(x: &'a i32, f: F) {
+ f(x);
+}
+
+fn fn_bound_3_cannot_elide() {
+ let x = 42;
+ let p = &x;
+ let mut q = &x;
+ // This will fail if we elide lifetimes of `fn_bound_3`.
+ fn_bound_3(p, |y| q = y);
+}
+
+// No error; multiple input refs.
+fn fn_bound_4<'a, F: FnOnce() -> &'a ()>(cond: bool, x: &'a (), f: F) -> &'a () {
+ if cond { x } else { f() }
+}
+
+struct X {
+ x: u8,
+}
+
+impl X {
+ fn self_and_out<'s>(&'s self) -> &'s u8 {
+ &self.x
+ }
+
+ // No error; multiple input refs.
+ fn self_and_in_out<'s, 't>(&'s self, _x: &'t u8) -> &'s u8 {
+ &self.x
+ }
+
+ fn distinct_self_and_in<'s, 't>(&'s self, _x: &'t u8) {}
+
+ // No error; same lifetimes on two params.
+ fn self_and_same_in<'s>(&'s self, _x: &'s u8) {}
+}
+
+struct Foo<'a>(&'a u8);
+
+impl<'a> Foo<'a> {
+ // No error; lifetime `'a` not defined in method.
+ fn self_shared_lifetime(&self, _: &'a u8) {}
+ // No error; bounds exist.
+ fn self_bound_lifetime<'b: 'a>(&self, _: &'b u8) {}
+}
+
+fn already_elided<'a>(_: &u8, _: &'a u8) -> &'a u8 {
+ unimplemented!()
+}
+
+fn struct_with_lt<'a>(_foo: Foo<'a>) -> &'a str {
+ unimplemented!()
+}
+
+// No warning; two input lifetimes (named on the reference, anonymous on `Foo`).
+fn struct_with_lt2<'a>(_foo: &'a Foo) -> &'a str {
+ unimplemented!()
+}
+
+// No warning; two input lifetimes (anonymous on the reference, named on `Foo`).
+fn struct_with_lt3<'a>(_foo: &Foo<'a>) -> &'a str {
+ unimplemented!()
+}
+
+// No warning; two input lifetimes.
+fn struct_with_lt4<'a, 'b>(_foo: &'a Foo<'b>) -> &'a str {
+ unimplemented!()
+}
+
+trait WithLifetime<'a> {}
+
+type WithLifetimeAlias<'a> = dyn WithLifetime<'a>;
+
+// Should not warn because it won't build without the lifetime.
+fn trait_obj_elided<'a>(_arg: &'a dyn WithLifetime) -> &'a str {
+ unimplemented!()
+}
+
+// Should warn because there is no lifetime on `Drop`, so this would be
+// unambiguous if we elided the lifetime.
+fn trait_obj_elided2<'a>(_arg: &'a dyn Drop) -> &'a str {
+ unimplemented!()
+}
+
+type FooAlias<'a> = Foo<'a>;
+
+fn alias_with_lt<'a>(_foo: FooAlias<'a>) -> &'a str {
+ unimplemented!()
+}
+
+// No warning; two input lifetimes (named on the reference, anonymous on `FooAlias`).
+fn alias_with_lt2<'a>(_foo: &'a FooAlias) -> &'a str {
+ unimplemented!()
+}
+
+// No warning; two input lifetimes (anonymous on the reference, named on `FooAlias`).
+fn alias_with_lt3<'a>(_foo: &FooAlias<'a>) -> &'a str {
+ unimplemented!()
+}
+
+// No warning; two input lifetimes.
+fn alias_with_lt4<'a, 'b>(_foo: &'a FooAlias<'b>) -> &'a str {
+ unimplemented!()
+}
+
+fn named_input_elided_output<'a>(_arg: &'a str) -> &str {
+ unimplemented!()
+}
+
+fn elided_input_named_output<'a>(_arg: &str) -> &'a str {
+ unimplemented!()
+}
+
+fn trait_bound_ok<'a, T: WithLifetime<'static>>(_: &'a u8, _: T) {
+ unimplemented!()
+}
+fn trait_bound<'a, T: WithLifetime<'a>>(_: &'a u8, _: T) {
+ unimplemented!()
+}
+
+// Don't warn on these; see issue #292.
+fn trait_bound_bug<'a, T: WithLifetime<'a>>() {
+ unimplemented!()
+}
+
+// See issue #740.
+struct Test {
+ vec: Vec<usize>,
+}
+
+impl Test {
+ fn iter<'a>(&'a self) -> Box<dyn Iterator<Item = usize> + 'a> {
+ unimplemented!()
+ }
+}
+
+trait LintContext<'a> {}
+
+fn f<'a, T: LintContext<'a>>(_: &T) {}
+
+fn test<'a>(x: &'a [u8]) -> u8 {
+ let y: &'a u8 = &x[5];
+ *y
+}
+
+// Issue #3284: give hint regarding lifetime in return type.
+struct Cow<'a> {
+ x: &'a str,
+}
+fn out_return_type_lts<'a>(e: &'a str) -> Cow<'a> {
+ unimplemented!()
+}
+
+// Make sure we still warn on implementations
+mod issue4291 {
+ trait BadTrait {
+ fn needless_lt<'a>(x: &'a u8) {}
+ }
+
+ impl BadTrait for () {
+ fn needless_lt<'a>(_x: &'a u8) {}
+ }
+}
+
+mod issue2944 {
+ trait Foo {}
+ struct Bar;
+ struct Baz<'a> {
+ bar: &'a Bar,
+ }
+
+ impl<'a> Foo for Baz<'a> {}
+ impl Bar {
+ fn baz<'a>(&'a self) -> impl Foo + 'a {
+ Baz { bar: self }
+ }
+ }
+}
+
+mod nested_elision_sites {
+ // issue #issue2944
+
+ // closure trait bounds subject to nested elision
+ // don't lint because they refer to outer lifetimes
+ fn trait_fn<'a>(i: &'a i32) -> impl Fn() -> &'a i32 {
+ move || i
+ }
+ fn trait_fn_mut<'a>(i: &'a i32) -> impl FnMut() -> &'a i32 {
+ move || i
+ }
+ fn trait_fn_once<'a>(i: &'a i32) -> impl FnOnce() -> &'a i32 {
+ move || i
+ }
+
+ // don't lint
+ fn impl_trait_in_input_position<'a>(f: impl Fn() -> &'a i32) -> &'a i32 {
+ f()
+ }
+ fn impl_trait_in_output_position<'a>(i: &'a i32) -> impl Fn() -> &'a i32 {
+ move || i
+ }
+ // lint
+ fn impl_trait_elidable_nested_named_lifetimes<'a>(i: &'a i32, f: impl for<'b> Fn(&'b i32) -> &'b i32) -> &'a i32 {
+ f(i)
+ }
+ fn impl_trait_elidable_nested_anonymous_lifetimes<'a>(i: &'a i32, f: impl Fn(&i32) -> &i32) -> &'a i32 {
+ f(i)
+ }
+
+ // don't lint
+ fn generics_not_elidable<'a, T: Fn() -> &'a i32>(f: T) -> &'a i32 {
+ f()
+ }
+ // lint
+ fn generics_elidable<'a, T: Fn(&i32) -> &i32>(i: &'a i32, f: T) -> &'a i32 {
+ f(i)
+ }
+
+ // don't lint
+ fn where_clause_not_elidable<'a, T>(f: T) -> &'a i32
+ where
+ T: Fn() -> &'a i32,
+ {
+ f()
+ }
+ // lint
+ fn where_clause_elidadable<'a, T>(i: &'a i32, f: T) -> &'a i32
+ where
+ T: Fn(&i32) -> &i32,
+ {
+ f(i)
+ }
+
+ // don't lint
+ fn pointer_fn_in_input_position<'a>(f: fn(&'a i32) -> &'a i32, i: &'a i32) -> &'a i32 {
+ f(i)
+ }
+ fn pointer_fn_in_output_position<'a>(_: &'a i32) -> fn(&'a i32) -> &'a i32 {
+ |i| i
+ }
+ // lint
+ fn pointer_fn_elidable<'a>(i: &'a i32, f: fn(&i32) -> &i32) -> &'a i32 {
+ f(i)
+ }
+
+ // don't lint
+ fn nested_fn_pointer_1<'a>(_: &'a i32) -> fn(fn(&'a i32) -> &'a i32) -> i32 {
+ |f| 42
+ }
+ fn nested_fn_pointer_2<'a>(_: &'a i32) -> impl Fn(fn(&'a i32)) {
+ |f| ()
+ }
+
+ // lint
+ fn nested_fn_pointer_3<'a>(_: &'a i32) -> fn(fn(&i32) -> &i32) -> i32 {
+ |f| 42
+ }
+ fn nested_fn_pointer_4<'a>(_: &'a i32) -> impl Fn(fn(&i32)) {
+ |f| ()
+ }
+}
+
+mod issue6159 {
+ use std::ops::Deref;
+ pub fn apply_deref<'a, T, F, R>(x: &'a T, f: F) -> R
+ where
+ T: Deref,
+ F: FnOnce(&'a T::Target) -> R,
+ {
+ f(x.deref())
+ }
+}
+
+mod issue7296 {
+ use std::rc::Rc;
+ use std::sync::Arc;
+
+ struct Foo;
+ impl Foo {
+ fn implicit<'a>(&'a self) -> &'a () {
+ &()
+ }
+ fn implicit_mut<'a>(&'a mut self) -> &'a () {
+ &()
+ }
+
+ fn explicit<'a>(self: &'a Arc<Self>) -> &'a () {
+ &()
+ }
+ fn explicit_mut<'a>(self: &'a mut Rc<Self>) -> &'a () {
+ &()
+ }
+
+ fn lifetime_elsewhere<'a>(self: Box<Self>, here: &'a ()) -> &'a () {
+ &()
+ }
+ }
+
+ trait Bar {
+ fn implicit<'a>(&'a self) -> &'a ();
+ fn implicit_provided<'a>(&'a self) -> &'a () {
+ &()
+ }
+
+ fn explicit<'a>(self: &'a Arc<Self>) -> &'a ();
+ fn explicit_provided<'a>(self: &'a Arc<Self>) -> &'a () {
+ &()
+ }
+
+ fn lifetime_elsewhere<'a>(self: Box<Self>, here: &'a ()) -> &'a ();
+ fn lifetime_elsewhere_provided<'a>(self: Box<Self>, here: &'a ()) -> &'a () {
+ &()
+ }
+ }
+}
+
+fn main() {}
--- /dev/null
- --> $DIR/needless_lifetimes.rs:10:1
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:12:1
++ --> $DIR/needless_lifetimes.rs:11:1
+ |
+LL | fn distinct_lifetimes<'a, 'b>(_x: &'a u8, _y: &'b u8, _z: u8) {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: `-D clippy::needless-lifetimes` implied by `-D warnings`
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:22:1
++ --> $DIR/needless_lifetimes.rs:13:1
+ |
+LL | fn distinct_and_static<'a, 'b>(_x: &'a u8, _y: &'b u8, _z: &'static u8) {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:56:1
++ --> $DIR/needless_lifetimes.rs:23:1
+ |
+LL | fn in_and_out<'a>(x: &'a u8, _y: u8) -> &'a u8 {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:61:1
++ --> $DIR/needless_lifetimes.rs:57:1
+ |
+LL | fn deep_reference_3<'a>(x: &'a u8, _y: u8) -> Result<&'a u8, ()> {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:73:1
++ --> $DIR/needless_lifetimes.rs:62:1
+ |
+LL | fn where_clause_without_lt<'a, T>(x: &'a u8, _y: u8) -> Result<&'a u8, ()>
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:97:1
++ --> $DIR/needless_lifetimes.rs:74:1
+ |
+LL | fn lifetime_param_2<'a, 'b>(_x: Ref<'a>, _y: &'b u8) {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:127:5
++ --> $DIR/needless_lifetimes.rs:98:1
+ |
+LL | fn fn_bound_2<'a, F, I>(_m: Lt<'a, I>, _f: F) -> Lt<'a, I>
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:136:5
++ --> $DIR/needless_lifetimes.rs:128:5
+ |
+LL | fn self_and_out<'s>(&'s self) -> &'s u8 {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:155:1
++ --> $DIR/needless_lifetimes.rs:137:5
+ |
+LL | fn distinct_self_and_in<'s, 't>(&'s self, _x: &'t u8) {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:185:1
++ --> $DIR/needless_lifetimes.rs:156:1
+ |
+LL | fn struct_with_lt<'a>(_foo: Foo<'a>) -> &'a str {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:191:1
++ --> $DIR/needless_lifetimes.rs:186:1
+ |
+LL | fn trait_obj_elided2<'a>(_arg: &'a dyn Drop) -> &'a str {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:210:1
++ --> $DIR/needless_lifetimes.rs:192:1
+ |
+LL | fn alias_with_lt<'a>(_foo: FooAlias<'a>) -> &'a str {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:218:1
++ --> $DIR/needless_lifetimes.rs:211:1
+ |
+LL | fn named_input_elided_output<'a>(_arg: &'a str) -> &str {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:254:1
++ --> $DIR/needless_lifetimes.rs:219:1
+ |
+LL | fn trait_bound_ok<'a, T: WithLifetime<'static>>(_: &'a u8, _: T) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:261:9
++ --> $DIR/needless_lifetimes.rs:255:1
+ |
+LL | fn out_return_type_lts<'a>(e: &'a str) -> Cow<'a> {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:265:9
++ --> $DIR/needless_lifetimes.rs:262:9
+ |
+LL | fn needless_lt<'a>(x: &'a u8) {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:278:9
++ --> $DIR/needless_lifetimes.rs:266:9
+ |
+LL | fn needless_lt<'a>(_x: &'a u8) {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:310:5
++ --> $DIR/needless_lifetimes.rs:279:9
+ |
+LL | fn baz<'a>(&'a self) -> impl Foo + 'a {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:319:5
++ --> $DIR/needless_lifetimes.rs:311:5
+ |
+LL | fn impl_trait_elidable_nested_anonymous_lifetimes<'a>(i: &'a i32, f: impl Fn(&i32) -> &i32) -> &'a i32 {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:331:5
++ --> $DIR/needless_lifetimes.rs:320:5
+ |
+LL | fn generics_elidable<'a, T: Fn(&i32) -> &i32>(i: &'a i32, f: T) -> &'a i32 {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:346:5
++ --> $DIR/needless_lifetimes.rs:332:5
+ |
+LL | fn where_clause_elidadable<'a, T>(i: &'a i32, f: T) -> &'a i32
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:359:5
++ --> $DIR/needless_lifetimes.rs:347:5
+ |
+LL | fn pointer_fn_elidable<'a>(i: &'a i32, f: fn(&i32) -> &i32) -> &'a i32 {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:362:5
++ --> $DIR/needless_lifetimes.rs:360:5
+ |
+LL | fn nested_fn_pointer_3<'a>(_: &'a i32) -> fn(fn(&i32) -> &i32) -> i32 {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:384:9
++ --> $DIR/needless_lifetimes.rs:363:5
+ |
+LL | fn nested_fn_pointer_4<'a>(_: &'a i32) -> impl Fn(fn(&i32)) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:387:9
++ --> $DIR/needless_lifetimes.rs:385:9
+ |
+LL | fn implicit<'a>(&'a self) -> &'a () {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:398:9
++ --> $DIR/needless_lifetimes.rs:388:9
+ |
+LL | fn implicit_mut<'a>(&'a mut self) -> &'a () {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:404:9
++ --> $DIR/needless_lifetimes.rs:399:9
+ |
+LL | fn lifetime_elsewhere<'a>(self: Box<Self>, here: &'a ()) -> &'a () {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:405:9
++ --> $DIR/needless_lifetimes.rs:405:9
+ |
+LL | fn implicit<'a>(&'a self) -> &'a ();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:414:9
++ --> $DIR/needless_lifetimes.rs:406:9
+ |
+LL | fn implicit_provided<'a>(&'a self) -> &'a () {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
- --> $DIR/needless_lifetimes.rs:415:9
++ --> $DIR/needless_lifetimes.rs:415:9
+ |
+LL | fn lifetime_elsewhere<'a>(self: Box<Self>, here: &'a ()) -> &'a ();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
++ --> $DIR/needless_lifetimes.rs:416:9
+ |
+LL | fn lifetime_elsewhere_provided<'a>(self: Box<Self>, here: &'a ()) -> &'a () {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 31 previous errors
+
--- /dev/null
- return the_answer!();
+// run-rustfix
+
+#![feature(let_else)]
+#![allow(unused)]
+#![allow(
+ clippy::if_same_then_else,
+ clippy::single_match,
+ clippy::needless_bool,
+ clippy::equatable_if_let
+)]
+#![warn(clippy::needless_return)]
+
+macro_rules! the_answer {
+ () => {
+ 42
+ };
+}
+
+fn test_end_of_fn() -> bool {
+ if true {
+ // no error!
+ return true;
+ }
+ true
+}
+
+fn test_no_semicolon() -> bool {
+ true
+}
+
+fn test_if_block() -> bool {
+ if true {
+ true
+ } else {
+ false
+ }
+}
+
+fn test_match(x: bool) -> bool {
+ match x {
+ true => false,
+ false => {
+ true
+ },
+ }
+}
+
+fn test_closure() {
+ let _ = || {
+ true
+ };
+ let _ = || true;
+}
+
+fn test_macro_call() -> i32 {
- return the_answer!();
++ the_answer!()
+}
+
+fn test_void_fun() {
+
+}
+
+fn test_void_if_fun(b: bool) {
+ if b {
+
+ } else {
+
+ }
+}
+
+fn test_void_match(x: u32) {
+ match x {
+ 0 => (),
+ _ => (),
+ }
+}
+
+fn test_nested_match(x: u32) {
+ match x {
+ 0 => (),
+ 1 => {
+ let _ = 42;
+
+ },
+ _ => (),
+ }
+}
+
+fn read_line() -> String {
+ use std::io::BufRead;
+ let stdin = ::std::io::stdin();
+ return stdin.lock().lines().next().unwrap().unwrap();
+}
+
+fn borrows_but_not_last(value: bool) -> String {
+ if value {
+ use std::io::BufRead;
+ let stdin = ::std::io::stdin();
+ let _a = stdin.lock().lines().next().unwrap().unwrap();
+ String::from("test")
+ } else {
+ String::new()
+ }
+}
+
+macro_rules! needed_return {
+ ($e:expr) => {
+ if $e > 3 {
+ return;
+ }
+ };
+}
+
+fn test_return_in_macro() {
+ // This will return and the macro below won't be executed. Removing the `return` from the macro
+ // will change semantics.
+ needed_return!(10);
+ needed_return!(0);
+}
+
+mod issue6501 {
+ #[allow(clippy::unnecessary_lazy_evaluations)]
+ fn foo(bar: Result<(), ()>) {
+ bar.unwrap_or_else(|_| {})
+ }
+
+ fn test_closure() {
+ let _ = || {
+
+ };
+ let _ = || {};
+ }
+
+ struct Foo;
+ #[allow(clippy::unnecessary_lazy_evaluations)]
+ fn bar(res: Result<Foo, u8>) -> Foo {
+ res.unwrap_or_else(|_| Foo)
+ }
+}
+
+async fn async_test_end_of_fn() -> bool {
+ if true {
+ // no error!
+ return true;
+ }
+ true
+}
+
+async fn async_test_no_semicolon() -> bool {
+ true
+}
+
+async fn async_test_if_block() -> bool {
+ if true {
+ true
+ } else {
+ false
+ }
+}
+
+async fn async_test_match(x: bool) -> bool {
+ match x {
+ true => false,
+ false => {
+ true
+ },
+ }
+}
+
+async fn async_test_closure() {
+ let _ = || {
+ true
+ };
+ let _ = || true;
+}
+
+async fn async_test_macro_call() -> i32 {
++ the_answer!()
+}
+
+async fn async_test_void_fun() {
+
+}
+
+async fn async_test_void_if_fun(b: bool) {
+ if b {
+
+ } else {
+
+ }
+}
+
+async fn async_test_void_match(x: u32) {
+ match x {
+ 0 => (),
+ _ => (),
+ }
+}
+
+async fn async_read_line() -> String {
+ use std::io::BufRead;
+ let stdin = ::std::io::stdin();
+ return stdin.lock().lines().next().unwrap().unwrap();
+}
+
+async fn async_borrows_but_not_last(value: bool) -> String {
+ if value {
+ use std::io::BufRead;
+ let stdin = ::std::io::stdin();
+ let _a = stdin.lock().lines().next().unwrap().unwrap();
+ String::from("test")
+ } else {
+ String::new()
+ }
+}
+
+async fn async_test_return_in_macro() {
+ needed_return!(10);
+ needed_return!(0);
+}
+
+fn let_else() {
+ let Some(1) = Some(1) else { return };
+}
+
++fn needless_return_macro() -> String {
++ let _ = "foo";
++ let _ = "bar";
++ format!("Hello {}", "world!")
++}
++
+fn main() {}
--- /dev/null
+// run-rustfix
+
+#![feature(let_else)]
+#![allow(unused)]
+#![allow(
+ clippy::if_same_then_else,
+ clippy::single_match,
+ clippy::needless_bool,
+ clippy::equatable_if_let
+)]
+#![warn(clippy::needless_return)]
+
+macro_rules! the_answer {
+ () => {
+ 42
+ };
+}
+
+fn test_end_of_fn() -> bool {
+ if true {
+ // no error!
+ return true;
+ }
+ return true;
+}
+
+fn test_no_semicolon() -> bool {
+ return true;
+}
+
+fn test_if_block() -> bool {
+ if true {
+ return true;
+ } else {
+ return false;
+ }
+}
+
+fn test_match(x: bool) -> bool {
+ match x {
+ true => return false,
+ false => {
+ return true;
+ },
+ }
+}
+
+fn test_closure() {
+ let _ = || {
+ return true;
+ };
+ let _ = || return true;
+}
+
+fn test_macro_call() -> i32 {
+ return the_answer!();
+}
+
+fn test_void_fun() {
+ return;
+}
+
+fn test_void_if_fun(b: bool) {
+ if b {
+ return;
+ } else {
+ return;
+ }
+}
+
+fn test_void_match(x: u32) {
+ match x {
+ 0 => (),
+ _ => return,
+ }
+}
+
+fn test_nested_match(x: u32) {
+ match x {
+ 0 => (),
+ 1 => {
+ let _ = 42;
+ return;
+ },
+ _ => return,
+ }
+}
+
+fn read_line() -> String {
+ use std::io::BufRead;
+ let stdin = ::std::io::stdin();
+ return stdin.lock().lines().next().unwrap().unwrap();
+}
+
+fn borrows_but_not_last(value: bool) -> String {
+ if value {
+ use std::io::BufRead;
+ let stdin = ::std::io::stdin();
+ let _a = stdin.lock().lines().next().unwrap().unwrap();
+ return String::from("test");
+ } else {
+ return String::new();
+ }
+}
+
+macro_rules! needed_return {
+ ($e:expr) => {
+ if $e > 3 {
+ return;
+ }
+ };
+}
+
+fn test_return_in_macro() {
+ // This will return and the macro below won't be executed. Removing the `return` from the macro
+ // will change semantics.
+ needed_return!(10);
+ needed_return!(0);
+}
+
+mod issue6501 {
+ #[allow(clippy::unnecessary_lazy_evaluations)]
+ fn foo(bar: Result<(), ()>) {
+ bar.unwrap_or_else(|_| return)
+ }
+
+ fn test_closure() {
+ let _ = || {
+ return;
+ };
+ let _ = || return;
+ }
+
+ struct Foo;
+ #[allow(clippy::unnecessary_lazy_evaluations)]
+ fn bar(res: Result<Foo, u8>) -> Foo {
+ res.unwrap_or_else(|_| return Foo)
+ }
+}
+
+async fn async_test_end_of_fn() -> bool {
+ if true {
+ // no error!
+ return true;
+ }
+ return true;
+}
+
+async fn async_test_no_semicolon() -> bool {
+ return true;
+}
+
+async fn async_test_if_block() -> bool {
+ if true {
+ return true;
+ } else {
+ return false;
+ }
+}
+
+async fn async_test_match(x: bool) -> bool {
+ match x {
+ true => return false,
+ false => {
+ return true;
+ },
+ }
+}
+
+async fn async_test_closure() {
+ let _ = || {
+ return true;
+ };
+ let _ = || return true;
+}
+
+async fn async_test_macro_call() -> i32 {
+ return the_answer!();
+}
+
+async fn async_test_void_fun() {
+ return;
+}
+
+async fn async_test_void_if_fun(b: bool) {
+ if b {
+ return;
+ } else {
+ return;
+ }
+}
+
+async fn async_test_void_match(x: u32) {
+ match x {
+ 0 => (),
+ _ => return,
+ }
+}
+
+async fn async_read_line() -> String {
+ use std::io::BufRead;
+ let stdin = ::std::io::stdin();
+ return stdin.lock().lines().next().unwrap().unwrap();
+}
+
+async fn async_borrows_but_not_last(value: bool) -> String {
+ if value {
+ use std::io::BufRead;
+ let stdin = ::std::io::stdin();
+ let _a = stdin.lock().lines().next().unwrap().unwrap();
+ return String::from("test");
+ } else {
+ return String::new();
+ }
+}
+
+async fn async_test_return_in_macro() {
+ needed_return!(10);
+ needed_return!(0);
+}
+
+fn let_else() {
+ let Some(1) = Some(1) else { return };
+}
+
++fn needless_return_macro() -> String {
++ let _ = "foo";
++ let _ = "bar";
++ return format!("Hello {}", "world!");
++}
++
+fn main() {}
--- /dev/null
- error: aborting due to 34 previous errors
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:24:5
+ |
+LL | return true;
+ | ^^^^^^^^^^^^ help: remove `return`: `true`
+ |
+ = note: `-D clippy::needless-return` implied by `-D warnings`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:28:5
+ |
+LL | return true;
+ | ^^^^^^^^^^^^ help: remove `return`: `true`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:33:9
+ |
+LL | return true;
+ | ^^^^^^^^^^^^ help: remove `return`: `true`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:35:9
+ |
+LL | return false;
+ | ^^^^^^^^^^^^^ help: remove `return`: `false`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:41:17
+ |
+LL | true => return false,
+ | ^^^^^^^^^^^^ help: remove `return`: `false`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:43:13
+ |
+LL | return true;
+ | ^^^^^^^^^^^^ help: remove `return`: `true`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:50:9
+ |
+LL | return true;
+ | ^^^^^^^^^^^^ help: remove `return`: `true`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:52:16
+ |
+LL | let _ = || return true;
+ | ^^^^^^^^^^^ help: remove `return`: `true`
+
++error: unneeded `return` statement
++ --> $DIR/needless_return.rs:56:5
++ |
++LL | return the_answer!();
++ | ^^^^^^^^^^^^^^^^^^^^^ help: remove `return`: `the_answer!()`
++
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:60:5
+ |
+LL | return;
+ | ^^^^^^^ help: remove `return`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:65:9
+ |
+LL | return;
+ | ^^^^^^^ help: remove `return`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:67:9
+ |
+LL | return;
+ | ^^^^^^^ help: remove `return`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:74:14
+ |
+LL | _ => return,
+ | ^^^^^^ help: replace `return` with a unit value: `()`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:83:13
+ |
+LL | return;
+ | ^^^^^^^ help: remove `return`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:85:14
+ |
+LL | _ => return,
+ | ^^^^^^ help: replace `return` with a unit value: `()`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:100:9
+ |
+LL | return String::from("test");
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return`: `String::from("test")`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:102:9
+ |
+LL | return String::new();
+ | ^^^^^^^^^^^^^^^^^^^^^ help: remove `return`: `String::new()`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:124:32
+ |
+LL | bar.unwrap_or_else(|_| return)
+ | ^^^^^^ help: replace `return` with an empty block: `{}`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:129:13
+ |
+LL | return;
+ | ^^^^^^^ help: remove `return`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:131:20
+ |
+LL | let _ = || return;
+ | ^^^^^^ help: replace `return` with an empty block: `{}`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:137:32
+ |
+LL | res.unwrap_or_else(|_| return Foo)
+ | ^^^^^^^^^^ help: remove `return`: `Foo`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:146:5
+ |
+LL | return true;
+ | ^^^^^^^^^^^^ help: remove `return`: `true`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:150:5
+ |
+LL | return true;
+ | ^^^^^^^^^^^^ help: remove `return`: `true`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:155:9
+ |
+LL | return true;
+ | ^^^^^^^^^^^^ help: remove `return`: `true`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:157:9
+ |
+LL | return false;
+ | ^^^^^^^^^^^^^ help: remove `return`: `false`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:163:17
+ |
+LL | true => return false,
+ | ^^^^^^^^^^^^ help: remove `return`: `false`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:165:13
+ |
+LL | return true;
+ | ^^^^^^^^^^^^ help: remove `return`: `true`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:172:9
+ |
+LL | return true;
+ | ^^^^^^^^^^^^ help: remove `return`: `true`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:174:16
+ |
+LL | let _ = || return true;
+ | ^^^^^^^^^^^ help: remove `return`: `true`
+
++error: unneeded `return` statement
++ --> $DIR/needless_return.rs:178:5
++ |
++LL | return the_answer!();
++ | ^^^^^^^^^^^^^^^^^^^^^ help: remove `return`: `the_answer!()`
++
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:182:5
+ |
+LL | return;
+ | ^^^^^^^ help: remove `return`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:187:9
+ |
+LL | return;
+ | ^^^^^^^ help: remove `return`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:189:9
+ |
+LL | return;
+ | ^^^^^^^ help: remove `return`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:196:14
+ |
+LL | _ => return,
+ | ^^^^^^ help: replace `return` with a unit value: `()`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:211:9
+ |
+LL | return String::from("test");
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return`: `String::from("test")`
+
+error: unneeded `return` statement
+ --> $DIR/needless_return.rs:213:9
+ |
+LL | return String::new();
+ | ^^^^^^^^^^^^^^^^^^^^^ help: remove `return`: `String::new()`
+
++error: unneeded `return` statement
++ --> $DIR/needless_return.rs:229:5
++ |
++LL | return format!("Hello {}", "world!");
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return`: `format!("Hello {}", "world!")`
++
++error: aborting due to 37 previous errors
+
--- /dev/null
--- /dev/null
++#![warn(clippy::no_effect_replace)]
++
++fn main() {
++ let _ = "12345".replace('1', "1");
++ let _ = "12345".replace("12", "12");
++ let _ = String::new().replace("12", "12");
++
++ let _ = "12345".replacen('1', "1", 1);
++ let _ = "12345".replacen("12", "12", 1);
++ let _ = String::new().replacen("12", "12", 1);
++
++ let _ = "12345".replace("12", "22");
++ let _ = "12345".replacen("12", "22", 1);
++
++ let mut x = X::default();
++ let _ = "hello".replace(&x.f(), &x.f());
++ let _ = "hello".replace(&x.f(), &x.ff());
++
++ let _ = "hello".replace(&y(), &y());
++ let _ = "hello".replace(&y(), &z());
++
++ let _ = Replaceme.replace("a", "a");
++}
++
++#[derive(Default)]
++struct X {}
++
++impl X {
++ fn f(&mut self) -> String {
++ "he".to_string()
++ }
++
++ fn ff(&mut self) -> String {
++ "hh".to_string()
++ }
++}
++
++fn y() -> String {
++ "he".to_string()
++}
++
++fn z() -> String {
++ "hh".to_string()
++}
++
++struct Replaceme;
++impl Replaceme {
++ pub fn replace(&mut self, a: &str, b: &str) -> Self {
++ Self
++ }
++}
--- /dev/null
--- /dev/null
++error: replacing text with itself
++ --> $DIR/no_effect_replace.rs:4:13
++ |
++LL | let _ = "12345".replace('1', "1");
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^
++ |
++ = note: `-D clippy::no-effect-replace` implied by `-D warnings`
++
++error: replacing text with itself
++ --> $DIR/no_effect_replace.rs:5:13
++ |
++LL | let _ = "12345".replace("12", "12");
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: replacing text with itself
++ --> $DIR/no_effect_replace.rs:6:13
++ |
++LL | let _ = String::new().replace("12", "12");
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: replacing text with itself
++ --> $DIR/no_effect_replace.rs:8:13
++ |
++LL | let _ = "12345".replacen('1', "1", 1);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: replacing text with itself
++ --> $DIR/no_effect_replace.rs:9:13
++ |
++LL | let _ = "12345".replacen("12", "12", 1);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: replacing text with itself
++ --> $DIR/no_effect_replace.rs:10:13
++ |
++LL | let _ = String::new().replacen("12", "12", 1);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: replacing text with itself
++ --> $DIR/no_effect_replace.rs:16:13
++ |
++LL | let _ = "hello".replace(&x.f(), &x.f());
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: replacing text with itself
++ --> $DIR/no_effect_replace.rs:19:13
++ |
++LL | let _ = "hello".replace(&y(), &y());
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: aborting due to 8 previous errors
++
--- /dev/null
--- /dev/null
++// run-rustfix
++#![allow(unused, clippy::diverging_sub_expression)]
++#![warn(clippy::nonminimal_bool)]
++
++fn methods_with_negation() {
++ let a: Option<i32> = unimplemented!();
++ let b: Result<i32, i32> = unimplemented!();
++ let _ = a.is_some();
++ let _ = a.is_none();
++ let _ = a.is_none();
++ let _ = a.is_some();
++ let _ = b.is_err();
++ let _ = b.is_ok();
++ let _ = b.is_ok();
++ let _ = b.is_err();
++ let c = false;
++ let _ = a.is_none() || c;
++ let _ = a.is_none() && c;
++ let _ = !(!c ^ c) || a.is_none();
++ let _ = (!c ^ c) || a.is_none();
++ let _ = !c ^ c || a.is_none();
++}
++
++// Simplified versions of https://github.com/rust-lang/rust-clippy/issues/2638
++// clippy::nonminimal_bool should only check the built-in Result and Some type, not
++// any other types like the following.
++enum CustomResultOk<E> {
++ Ok,
++ Err(E),
++}
++enum CustomResultErr<E> {
++ Ok,
++ Err(E),
++}
++enum CustomSomeSome<T> {
++ Some(T),
++ None,
++}
++enum CustomSomeNone<T> {
++ Some(T),
++ None,
++}
++
++impl<E> CustomResultOk<E> {
++ pub fn is_ok(&self) -> bool {
++ true
++ }
++}
++
++impl<E> CustomResultErr<E> {
++ pub fn is_err(&self) -> bool {
++ true
++ }
++}
++
++impl<T> CustomSomeSome<T> {
++ pub fn is_some(&self) -> bool {
++ true
++ }
++}
++
++impl<T> CustomSomeNone<T> {
++ pub fn is_none(&self) -> bool {
++ true
++ }
++}
++
++fn dont_warn_for_custom_methods_with_negation() {
++ let res = CustomResultOk::Err("Error");
++ // Should not warn and suggest 'is_err()' because the type does not
++ // implement is_err().
++ if !res.is_ok() {}
++
++ let res = CustomResultErr::Err("Error");
++ // Should not warn and suggest 'is_ok()' because the type does not
++ // implement is_ok().
++ if !res.is_err() {}
++
++ let res = CustomSomeSome::Some("thing");
++ // Should not warn and suggest 'is_none()' because the type does not
++ // implement is_none().
++ if !res.is_some() {}
++
++ let res = CustomSomeNone::Some("thing");
++ // Should not warn and suggest 'is_some()' because the type does not
++ // implement is_some().
++ if !res.is_none() {}
++}
++
++// Only Built-in Result and Some types should suggest the negated alternative
++fn warn_for_built_in_methods_with_negation() {
++ let res: Result<usize, usize> = Ok(1);
++ if res.is_err() {}
++ if res.is_ok() {}
++
++ let res = Some(1);
++ if res.is_none() {}
++ if res.is_some() {}
++}
++
++#[allow(clippy::neg_cmp_op_on_partial_ord)]
++fn dont_warn_for_negated_partial_ord_comparison() {
++ let a: f64 = unimplemented!();
++ let b: f64 = unimplemented!();
++ let _ = !(a < b);
++ let _ = !(a <= b);
++ let _ = !(a > b);
++ let _ = !(a >= b);
++}
++
++fn main() {}
--- /dev/null
++// run-rustfix
+#![allow(unused, clippy::diverging_sub_expression)]
+#![warn(clippy::nonminimal_bool)]
+
+fn methods_with_negation() {
+ let a: Option<i32> = unimplemented!();
+ let b: Result<i32, i32> = unimplemented!();
+ let _ = a.is_some();
+ let _ = !a.is_some();
+ let _ = a.is_none();
+ let _ = !a.is_none();
+ let _ = b.is_err();
+ let _ = !b.is_err();
+ let _ = b.is_ok();
+ let _ = !b.is_ok();
+ let c = false;
+ let _ = !(a.is_some() && !c);
+ let _ = !(a.is_some() || !c);
+ let _ = !(!c ^ c) || !a.is_some();
+ let _ = (!c ^ c) || !a.is_some();
+ let _ = !c ^ c || !a.is_some();
+}
+
+// Simplified versions of https://github.com/rust-lang/rust-clippy/issues/2638
+// clippy::nonminimal_bool should only check the built-in Result and Some type, not
+// any other types like the following.
+enum CustomResultOk<E> {
+ Ok,
+ Err(E),
+}
+enum CustomResultErr<E> {
+ Ok,
+ Err(E),
+}
+enum CustomSomeSome<T> {
+ Some(T),
+ None,
+}
+enum CustomSomeNone<T> {
+ Some(T),
+ None,
+}
+
+impl<E> CustomResultOk<E> {
+ pub fn is_ok(&self) -> bool {
+ true
+ }
+}
+
+impl<E> CustomResultErr<E> {
+ pub fn is_err(&self) -> bool {
+ true
+ }
+}
+
+impl<T> CustomSomeSome<T> {
+ pub fn is_some(&self) -> bool {
+ true
+ }
+}
+
+impl<T> CustomSomeNone<T> {
+ pub fn is_none(&self) -> bool {
+ true
+ }
+}
+
+fn dont_warn_for_custom_methods_with_negation() {
+ let res = CustomResultOk::Err("Error");
+ // Should not warn and suggest 'is_err()' because the type does not
+ // implement is_err().
+ if !res.is_ok() {}
+
+ let res = CustomResultErr::Err("Error");
+ // Should not warn and suggest 'is_ok()' because the type does not
+ // implement is_ok().
+ if !res.is_err() {}
+
+ let res = CustomSomeSome::Some("thing");
+ // Should not warn and suggest 'is_none()' because the type does not
+ // implement is_none().
+ if !res.is_some() {}
+
+ let res = CustomSomeNone::Some("thing");
+ // Should not warn and suggest 'is_some()' because the type does not
+ // implement is_some().
+ if !res.is_none() {}
+}
+
+// Only Built-in Result and Some types should suggest the negated alternative
+fn warn_for_built_in_methods_with_negation() {
+ let res: Result<usize, usize> = Ok(1);
+ if !res.is_ok() {}
+ if !res.is_err() {}
+
+ let res = Some(1);
+ if !res.is_some() {}
+ if !res.is_none() {}
+}
+
+#[allow(clippy::neg_cmp_op_on_partial_ord)]
+fn dont_warn_for_negated_partial_ord_comparison() {
+ let a: f64 = unimplemented!();
+ let b: f64 = unimplemented!();
+ let _ = !(a < b);
+ let _ = !(a <= b);
+ let _ = !(a > b);
+ let _ = !(a >= b);
+}
+
+fn main() {}
--- /dev/null
- --> $DIR/nonminimal_bool_methods.rs:8:13
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:10:13
++ --> $DIR/nonminimal_bool_methods.rs:9:13
+ |
+LL | let _ = !a.is_some();
+ | ^^^^^^^^^^^^ help: try: `a.is_none()`
+ |
+ = note: `-D clippy::nonminimal-bool` implied by `-D warnings`
+
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:12:13
++ --> $DIR/nonminimal_bool_methods.rs:11:13
+ |
+LL | let _ = !a.is_none();
+ | ^^^^^^^^^^^^ help: try: `a.is_some()`
+
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:14:13
++ --> $DIR/nonminimal_bool_methods.rs:13:13
+ |
+LL | let _ = !b.is_err();
+ | ^^^^^^^^^^^ help: try: `b.is_ok()`
+
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:16:13
++ --> $DIR/nonminimal_bool_methods.rs:15:13
+ |
+LL | let _ = !b.is_ok();
+ | ^^^^^^^^^^ help: try: `b.is_err()`
+
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:17:13
++ --> $DIR/nonminimal_bool_methods.rs:17:13
+ |
+LL | let _ = !(a.is_some() && !c);
+ | ^^^^^^^^^^^^^^^^^^^^ help: try: `a.is_none() || c`
+
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:18:26
++ --> $DIR/nonminimal_bool_methods.rs:18:13
+ |
+LL | let _ = !(a.is_some() || !c);
+ | ^^^^^^^^^^^^^^^^^^^^ help: try: `a.is_none() && c`
+
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:19:25
++ --> $DIR/nonminimal_bool_methods.rs:19:26
+ |
+LL | let _ = !(!c ^ c) || !a.is_some();
+ | ^^^^^^^^^^^^ help: try: `a.is_none()`
+
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:20:23
++ --> $DIR/nonminimal_bool_methods.rs:20:25
+ |
+LL | let _ = (!c ^ c) || !a.is_some();
+ | ^^^^^^^^^^^^ help: try: `a.is_none()`
+
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:92:8
++ --> $DIR/nonminimal_bool_methods.rs:21:23
+ |
+LL | let _ = !c ^ c || !a.is_some();
+ | ^^^^^^^^^^^^ help: try: `a.is_none()`
+
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:93:8
++ --> $DIR/nonminimal_bool_methods.rs:93:8
+ |
+LL | if !res.is_ok() {}
+ | ^^^^^^^^^^^^ help: try: `res.is_err()`
+
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:96:8
++ --> $DIR/nonminimal_bool_methods.rs:94:8
+ |
+LL | if !res.is_err() {}
+ | ^^^^^^^^^^^^^ help: try: `res.is_ok()`
+
+error: this boolean expression can be simplified
- --> $DIR/nonminimal_bool_methods.rs:97:8
++ --> $DIR/nonminimal_bool_methods.rs:97:8
+ |
+LL | if !res.is_some() {}
+ | ^^^^^^^^^^^^^^ help: try: `res.is_none()`
+
+error: this boolean expression can be simplified
++ --> $DIR/nonminimal_bool_methods.rs:98:8
+ |
+LL | if !res.is_none() {}
+ | ^^^^^^^^^^^^^^ help: try: `res.is_some()`
+
+error: aborting due to 13 previous errors
+
--- /dev/null
+// run-rustfix
+
+#[warn(clippy::manual_range_contains)]
+#[allow(unused)]
+#[allow(clippy::no_effect)]
+#[allow(clippy::short_circuit_statement)]
+#[allow(clippy::unnecessary_operation)]
+fn main() {
+ let x = 9_i32;
+
+ // order shouldn't matter
+ (8..12).contains(&x);
+ (21..42).contains(&x);
+ (1..100).contains(&x);
+
+ // also with inclusive ranges
+ (9..=99).contains(&x);
+ (1..=33).contains(&x);
+ (1..=999).contains(&x);
+
+ // and the outside
+ !(8..12).contains(&x);
+ !(21..42).contains(&x);
+ !(1..100).contains(&x);
+
+ // also with the outside of inclusive ranges
+ !(9..=99).contains(&x);
+ !(1..=33).contains(&x);
+ !(1..=999).contains(&x);
+
+ // not a range.contains
+ x > 8 && x < 12; // lower bound not inclusive
+ x < 8 && x <= 12; // same direction
+ x >= 12 && 12 >= x; // same bounds
+ x < 8 && x > 12; // wrong direction
+
+ x <= 8 || x >= 12;
+ x >= 8 || x >= 12;
+ x < 12 || 12 < x;
+ x >= 8 || x <= 12;
+
+ // Fix #6315
+ let y = 3.;
+ (0. ..1.).contains(&y);
+ !(0. ..=1.).contains(&y);
+
+ // handle negatives #8721
+ (-10..=10).contains(&x);
+ x >= 10 && x <= -10;
+ (-3. ..=3.).contains(&y);
+ y >= 3. && y <= -3.;
++
++ // Fix #8745
++ let z = 42;
++ (0..=10).contains(&x) && (0..=10).contains(&z);
++ !(0..10).contains(&x) || !(0..10).contains(&z);
++ // Make sure operators in parens don't give a breaking suggestion
++ ((x % 2 == 0) || (x < 0)) || (x >= 10);
+}
+
+// Fix #6373
+pub const fn in_range(a: i32) -> bool {
+ 3 <= a && a <= 20
+}
--- /dev/null
+// run-rustfix
+
+#[warn(clippy::manual_range_contains)]
+#[allow(unused)]
+#[allow(clippy::no_effect)]
+#[allow(clippy::short_circuit_statement)]
+#[allow(clippy::unnecessary_operation)]
+fn main() {
+ let x = 9_i32;
+
+ // order shouldn't matter
+ x >= 8 && x < 12;
+ x < 42 && x >= 21;
+ 100 > x && 1 <= x;
+
+ // also with inclusive ranges
+ x >= 9 && x <= 99;
+ x <= 33 && x >= 1;
+ 999 >= x && 1 <= x;
+
+ // and the outside
+ x < 8 || x >= 12;
+ x >= 42 || x < 21;
+ 100 <= x || 1 > x;
+
+ // also with the outside of inclusive ranges
+ x < 9 || x > 99;
+ x > 33 || x < 1;
+ 999 < x || 1 > x;
+
+ // not a range.contains
+ x > 8 && x < 12; // lower bound not inclusive
+ x < 8 && x <= 12; // same direction
+ x >= 12 && 12 >= x; // same bounds
+ x < 8 && x > 12; // wrong direction
+
+ x <= 8 || x >= 12;
+ x >= 8 || x >= 12;
+ x < 12 || 12 < x;
+ x >= 8 || x <= 12;
+
+ // Fix #6315
+ let y = 3.;
+ y >= 0. && y < 1.;
+ y < 0. || y > 1.;
+
+ // handle negatives #8721
+ x >= -10 && x <= 10;
+ x >= 10 && x <= -10;
+ y >= -3. && y <= 3.;
+ y >= 3. && y <= -3.;
++
++ // Fix #8745
++ let z = 42;
++ (x >= 0) && (x <= 10) && (z >= 0) && (z <= 10);
++ (x < 0) || (x >= 10) || (z < 0) || (z >= 10);
++ // Make sure operators in parens don't give a breaking suggestion
++ ((x % 2 == 0) || (x < 0)) || (x >= 10);
+}
+
+// Fix #6373
+pub const fn in_range(a: i32) -> bool {
+ 3 <= a && a <= 20
+}
--- /dev/null
- error: aborting due to 16 previous errors
+error: manual `Range::contains` implementation
+ --> $DIR/range_contains.rs:12:5
+ |
+LL | x >= 8 && x < 12;
+ | ^^^^^^^^^^^^^^^^ help: use: `(8..12).contains(&x)`
+ |
+ = note: `-D clippy::manual-range-contains` implied by `-D warnings`
+
+error: manual `Range::contains` implementation
+ --> $DIR/range_contains.rs:13:5
+ |
+LL | x < 42 && x >= 21;
+ | ^^^^^^^^^^^^^^^^^ help: use: `(21..42).contains(&x)`
+
+error: manual `Range::contains` implementation
+ --> $DIR/range_contains.rs:14:5
+ |
+LL | 100 > x && 1 <= x;
+ | ^^^^^^^^^^^^^^^^^ help: use: `(1..100).contains(&x)`
+
+error: manual `RangeInclusive::contains` implementation
+ --> $DIR/range_contains.rs:17:5
+ |
+LL | x >= 9 && x <= 99;
+ | ^^^^^^^^^^^^^^^^^ help: use: `(9..=99).contains(&x)`
+
+error: manual `RangeInclusive::contains` implementation
+ --> $DIR/range_contains.rs:18:5
+ |
+LL | x <= 33 && x >= 1;
+ | ^^^^^^^^^^^^^^^^^ help: use: `(1..=33).contains(&x)`
+
+error: manual `RangeInclusive::contains` implementation
+ --> $DIR/range_contains.rs:19:5
+ |
+LL | 999 >= x && 1 <= x;
+ | ^^^^^^^^^^^^^^^^^^ help: use: `(1..=999).contains(&x)`
+
+error: manual `!Range::contains` implementation
+ --> $DIR/range_contains.rs:22:5
+ |
+LL | x < 8 || x >= 12;
+ | ^^^^^^^^^^^^^^^^ help: use: `!(8..12).contains(&x)`
+
+error: manual `!Range::contains` implementation
+ --> $DIR/range_contains.rs:23:5
+ |
+LL | x >= 42 || x < 21;
+ | ^^^^^^^^^^^^^^^^^ help: use: `!(21..42).contains(&x)`
+
+error: manual `!Range::contains` implementation
+ --> $DIR/range_contains.rs:24:5
+ |
+LL | 100 <= x || 1 > x;
+ | ^^^^^^^^^^^^^^^^^ help: use: `!(1..100).contains(&x)`
+
+error: manual `!RangeInclusive::contains` implementation
+ --> $DIR/range_contains.rs:27:5
+ |
+LL | x < 9 || x > 99;
+ | ^^^^^^^^^^^^^^^ help: use: `!(9..=99).contains(&x)`
+
+error: manual `!RangeInclusive::contains` implementation
+ --> $DIR/range_contains.rs:28:5
+ |
+LL | x > 33 || x < 1;
+ | ^^^^^^^^^^^^^^^ help: use: `!(1..=33).contains(&x)`
+
+error: manual `!RangeInclusive::contains` implementation
+ --> $DIR/range_contains.rs:29:5
+ |
+LL | 999 < x || 1 > x;
+ | ^^^^^^^^^^^^^^^^ help: use: `!(1..=999).contains(&x)`
+
+error: manual `Range::contains` implementation
+ --> $DIR/range_contains.rs:44:5
+ |
+LL | y >= 0. && y < 1.;
+ | ^^^^^^^^^^^^^^^^^ help: use: `(0. ..1.).contains(&y)`
+
+error: manual `!RangeInclusive::contains` implementation
+ --> $DIR/range_contains.rs:45:5
+ |
+LL | y < 0. || y > 1.;
+ | ^^^^^^^^^^^^^^^^ help: use: `!(0. ..=1.).contains(&y)`
+
+error: manual `RangeInclusive::contains` implementation
+ --> $DIR/range_contains.rs:48:5
+ |
+LL | x >= -10 && x <= 10;
+ | ^^^^^^^^^^^^^^^^^^^ help: use: `(-10..=10).contains(&x)`
+
+error: manual `RangeInclusive::contains` implementation
+ --> $DIR/range_contains.rs:50:5
+ |
+LL | y >= -3. && y <= 3.;
+ | ^^^^^^^^^^^^^^^^^^^ help: use: `(-3. ..=3.).contains(&y)`
+
++error: manual `RangeInclusive::contains` implementation
++ --> $DIR/range_contains.rs:55:30
++ |
++LL | (x >= 0) && (x <= 10) && (z >= 0) && (z <= 10);
++ | ^^^^^^^^^^^^^^^^^^^^^ help: use: `(0..=10).contains(&z)`
++
++error: manual `RangeInclusive::contains` implementation
++ --> $DIR/range_contains.rs:55:5
++ |
++LL | (x >= 0) && (x <= 10) && (z >= 0) && (z <= 10);
++ | ^^^^^^^^^^^^^^^^^^^^^ help: use: `(0..=10).contains(&x)`
++
++error: manual `!Range::contains` implementation
++ --> $DIR/range_contains.rs:56:29
++ |
++LL | (x < 0) || (x >= 10) || (z < 0) || (z >= 10);
++ | ^^^^^^^^^^^^^^^^^^^^ help: use: `!(0..10).contains(&z)`
++
++error: manual `!Range::contains` implementation
++ --> $DIR/range_contains.rs:56:5
++ |
++LL | (x < 0) || (x >= 10) || (z < 0) || (z >= 10);
++ | ^^^^^^^^^^^^^^^^^^^^ help: use: `!(0..10).contains(&x)`
++
++error: aborting due to 20 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::rc_buffer)]
++#![allow(dead_code, unused_imports)]
++
++use std::cell::RefCell;
++use std::ffi::OsString;
++use std::path::PathBuf;
++use std::rc::Rc;
++
++struct S {
++ // triggers lint
++ bad1: Rc<str>,
++ bad2: Rc<std::path::Path>,
++ bad3: Rc<[u8]>,
++ bad4: Rc<std::ffi::OsStr>,
++ // does not trigger lint
++ good1: Rc<RefCell<String>>,
++}
++
++// triggers lint
++fn func_bad1(_: Rc<str>) {}
++fn func_bad2(_: Rc<std::path::Path>) {}
++fn func_bad3(_: Rc<[u8]>) {}
++fn func_bad4(_: Rc<std::ffi::OsStr>) {}
++// does not trigger lint
++fn func_good1(_: Rc<RefCell<String>>) {}
++
++fn main() {}
--- /dev/null
++// run-rustfix
+#![warn(clippy::rc_buffer)]
++#![allow(dead_code, unused_imports)]
+
+use std::cell::RefCell;
+use std::ffi::OsString;
+use std::path::PathBuf;
+use std::rc::Rc;
+
+struct S {
+ // triggers lint
+ bad1: Rc<String>,
+ bad2: Rc<PathBuf>,
+ bad3: Rc<Vec<u8>>,
+ bad4: Rc<OsString>,
+ // does not trigger lint
+ good1: Rc<RefCell<String>>,
+}
+
+// triggers lint
+fn func_bad1(_: Rc<String>) {}
+fn func_bad2(_: Rc<PathBuf>) {}
+fn func_bad3(_: Rc<Vec<u8>>) {}
+fn func_bad4(_: Rc<OsString>) {}
+// does not trigger lint
+fn func_good1(_: Rc<RefCell<String>>) {}
+
+fn main() {}
--- /dev/null
- --> $DIR/rc_buffer.rs:10:11
+error: usage of `Rc<T>` when T is a buffer type
- --> $DIR/rc_buffer.rs:11:11
++ --> $DIR/rc_buffer.rs:12:11
+ |
+LL | bad1: Rc<String>,
+ | ^^^^^^^^^^ help: try: `Rc<str>`
+ |
+ = note: `-D clippy::rc-buffer` implied by `-D warnings`
+
+error: usage of `Rc<T>` when T is a buffer type
- --> $DIR/rc_buffer.rs:12:11
++ --> $DIR/rc_buffer.rs:13:11
+ |
+LL | bad2: Rc<PathBuf>,
+ | ^^^^^^^^^^^ help: try: `Rc<std::path::Path>`
+
+error: usage of `Rc<T>` when T is a buffer type
- --> $DIR/rc_buffer.rs:13:11
++ --> $DIR/rc_buffer.rs:14:11
+ |
+LL | bad3: Rc<Vec<u8>>,
+ | ^^^^^^^^^^^ help: try: `Rc<[u8]>`
+
+error: usage of `Rc<T>` when T is a buffer type
- --> $DIR/rc_buffer.rs:19:17
++ --> $DIR/rc_buffer.rs:15:11
+ |
+LL | bad4: Rc<OsString>,
+ | ^^^^^^^^^^^^ help: try: `Rc<std::ffi::OsStr>`
+
+error: usage of `Rc<T>` when T is a buffer type
- --> $DIR/rc_buffer.rs:20:17
++ --> $DIR/rc_buffer.rs:21:17
+ |
+LL | fn func_bad1(_: Rc<String>) {}
+ | ^^^^^^^^^^ help: try: `Rc<str>`
+
+error: usage of `Rc<T>` when T is a buffer type
- --> $DIR/rc_buffer.rs:21:17
++ --> $DIR/rc_buffer.rs:22:17
+ |
+LL | fn func_bad2(_: Rc<PathBuf>) {}
+ | ^^^^^^^^^^^ help: try: `Rc<std::path::Path>`
+
+error: usage of `Rc<T>` when T is a buffer type
- --> $DIR/rc_buffer.rs:22:17
++ --> $DIR/rc_buffer.rs:23:17
+ |
+LL | fn func_bad3(_: Rc<Vec<u8>>) {}
+ | ^^^^^^^^^^^ help: try: `Rc<[u8]>`
+
+error: usage of `Rc<T>` when T is a buffer type
++ --> $DIR/rc_buffer.rs:24:17
+ |
+LL | fn func_bad4(_: Rc<OsString>) {}
+ | ^^^^^^^^^^^^ help: try: `Rc<std::ffi::OsStr>`
+
+error: aborting due to 8 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::rc_buffer)]
++#![allow(dead_code, unused_imports)]
++
++use std::ffi::OsString;
++use std::path::PathBuf;
++use std::sync::{Arc, Mutex};
++
++struct S {
++ // triggers lint
++ bad1: Arc<str>,
++ bad2: Arc<std::path::Path>,
++ bad3: Arc<[u8]>,
++ bad4: Arc<std::ffi::OsStr>,
++ // does not trigger lint
++ good1: Arc<Mutex<String>>,
++}
++
++// triggers lint
++fn func_bad1(_: Arc<str>) {}
++fn func_bad2(_: Arc<std::path::Path>) {}
++fn func_bad3(_: Arc<[u8]>) {}
++fn func_bad4(_: Arc<std::ffi::OsStr>) {}
++// does not trigger lint
++fn func_good1(_: Arc<Mutex<String>>) {}
++
++fn main() {}
--- /dev/null
++// run-rustfix
+#![warn(clippy::rc_buffer)]
++#![allow(dead_code, unused_imports)]
+
+use std::ffi::OsString;
+use std::path::PathBuf;
+use std::sync::{Arc, Mutex};
+
+struct S {
+ // triggers lint
+ bad1: Arc<String>,
+ bad2: Arc<PathBuf>,
+ bad3: Arc<Vec<u8>>,
+ bad4: Arc<OsString>,
+ // does not trigger lint
+ good1: Arc<Mutex<String>>,
+}
+
+// triggers lint
+fn func_bad1(_: Arc<String>) {}
+fn func_bad2(_: Arc<PathBuf>) {}
+fn func_bad3(_: Arc<Vec<u8>>) {}
+fn func_bad4(_: Arc<OsString>) {}
+// does not trigger lint
+fn func_good1(_: Arc<Mutex<String>>) {}
+
+fn main() {}
--- /dev/null
- --> $DIR/rc_buffer_arc.rs:9:11
+error: usage of `Arc<T>` when T is a buffer type
- --> $DIR/rc_buffer_arc.rs:10:11
++ --> $DIR/rc_buffer_arc.rs:11:11
+ |
+LL | bad1: Arc<String>,
+ | ^^^^^^^^^^^ help: try: `Arc<str>`
+ |
+ = note: `-D clippy::rc-buffer` implied by `-D warnings`
+
+error: usage of `Arc<T>` when T is a buffer type
- --> $DIR/rc_buffer_arc.rs:11:11
++ --> $DIR/rc_buffer_arc.rs:12:11
+ |
+LL | bad2: Arc<PathBuf>,
+ | ^^^^^^^^^^^^ help: try: `Arc<std::path::Path>`
+
+error: usage of `Arc<T>` when T is a buffer type
- --> $DIR/rc_buffer_arc.rs:12:11
++ --> $DIR/rc_buffer_arc.rs:13:11
+ |
+LL | bad3: Arc<Vec<u8>>,
+ | ^^^^^^^^^^^^ help: try: `Arc<[u8]>`
+
+error: usage of `Arc<T>` when T is a buffer type
- --> $DIR/rc_buffer_arc.rs:18:17
++ --> $DIR/rc_buffer_arc.rs:14:11
+ |
+LL | bad4: Arc<OsString>,
+ | ^^^^^^^^^^^^^ help: try: `Arc<std::ffi::OsStr>`
+
+error: usage of `Arc<T>` when T is a buffer type
- --> $DIR/rc_buffer_arc.rs:19:17
++ --> $DIR/rc_buffer_arc.rs:20:17
+ |
+LL | fn func_bad1(_: Arc<String>) {}
+ | ^^^^^^^^^^^ help: try: `Arc<str>`
+
+error: usage of `Arc<T>` when T is a buffer type
- --> $DIR/rc_buffer_arc.rs:20:17
++ --> $DIR/rc_buffer_arc.rs:21:17
+ |
+LL | fn func_bad2(_: Arc<PathBuf>) {}
+ | ^^^^^^^^^^^^ help: try: `Arc<std::path::Path>`
+
+error: usage of `Arc<T>` when T is a buffer type
- --> $DIR/rc_buffer_arc.rs:21:17
++ --> $DIR/rc_buffer_arc.rs:22:17
+ |
+LL | fn func_bad3(_: Arc<Vec<u8>>) {}
+ | ^^^^^^^^^^^^ help: try: `Arc<[u8]>`
+
+error: usage of `Arc<T>` when T is a buffer type
++ --> $DIR/rc_buffer_arc.rs:23:17
+ |
+LL | fn func_bad4(_: Arc<OsString>) {}
+ | ^^^^^^^^^^^^^ help: try: `Arc<std::ffi::OsStr>`
+
+error: aborting due to 8 previous errors
+
--- /dev/null
- error: calling `Arc::new` in `vec![elem; len]`
++error: initializing a reference-counted pointer in `vec![elem; len]`
+ --> $DIR/arc.rs:7:13
+ |
+LL | let v = vec![Arc::new("x".to_string()); 2];
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: `-D clippy::rc-clone-in-vec-init` implied by `-D warnings`
+ = note: each element will point to the same `Arc` instance
+help: consider initializing each `Arc` element individually
+ |
+LL ~ let v = {
+LL + let mut v = Vec::with_capacity(2);
- LL + (0..2).for_each(|_| v.push(Arc::new("x".to_string())));
++LL + (0..2).for_each(|_| v.push(Arc::new(..)));
+LL + v
+LL ~ };
+ |
+help: or if this is intentional, consider extracting the `Arc` initialization to a variable
+ |
+LL ~ let v = {
- LL + let data = Arc::new("x".to_string());
++LL + let data = Arc::new(..);
+LL + vec![data; 2]
+LL ~ };
+ |
+
- error: calling `Arc::new` in `vec![elem; len]`
++error: initializing a reference-counted pointer in `vec![elem; len]`
+ --> $DIR/arc.rs:15:21
+ |
+LL | let v = vec![Arc::new("x".to_string()); 2];
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: each element will point to the same `Arc` instance
+help: consider initializing each `Arc` element individually
+ |
+LL ~ let v = {
+LL + let mut v = Vec::with_capacity(2);
- LL + (0..2).for_each(|_| v.push(Arc::new("x".to_string())));
++LL + (0..2).for_each(|_| v.push(Arc::new(..)));
+LL + v
+LL ~ };
+ |
+help: or if this is intentional, consider extracting the `Arc` initialization to a variable
+ |
+LL ~ let v = {
- LL + let data = Arc::new("x".to_string());
++LL + let data = Arc::new(..);
+LL + vec![data; 2]
+LL ~ };
+ |
+
- error: calling `Arc::new` in `vec![elem; len]`
++error: initializing a reference-counted pointer in `vec![elem; len]`
+ --> $DIR/arc.rs:21:13
+ |
+LL | let v = vec![
+ | _____________^
+LL | | std::sync::Arc::new(Mutex::new({
+LL | | let x = 1;
+LL | | dbg!(x);
+... |
+LL | | 2
+LL | | ];
+ | |_____^
+ |
+ = note: each element will point to the same `Arc` instance
+help: consider initializing each `Arc` element individually
+ |
+LL ~ let v = {
+LL + let mut v = Vec::with_capacity(2);
+LL + (0..2).for_each(|_| v.push(std::sync::Arc::new(..)));
+LL + v
+LL ~ };
+ |
+help: or if this is intentional, consider extracting the `Arc` initialization to a variable
+ |
+LL ~ let v = {
+LL + let data = std::sync::Arc::new(..);
+LL + vec![data; 2]
+LL ~ };
+ |
+
- error: calling `Arc::new` in `vec![elem; len]`
++error: initializing a reference-counted pointer in `vec![elem; len]`
+ --> $DIR/arc.rs:30:14
+ |
+LL | let v1 = vec![
+ | ______________^
+LL | | Arc::new(Mutex::new({
+LL | | let x = 1;
+LL | | dbg!(x);
+... |
+LL | | 2
+LL | | ];
+ | |_____^
+ |
+ = note: each element will point to the same `Arc` instance
+help: consider initializing each `Arc` element individually
+ |
+LL ~ let v1 = {
+LL + let mut v = Vec::with_capacity(2);
+LL + (0..2).for_each(|_| v.push(Arc::new(..)));
+LL + v
+LL ~ };
+ |
+help: or if this is intentional, consider extracting the `Arc` initialization to a variable
+ |
+LL ~ let v1 = {
+LL + let data = Arc::new(..);
+LL + vec![data; 2]
+LL ~ };
+ |
+
+error: aborting due to 4 previous errors
+
--- /dev/null
- error: calling `Rc::new` in `vec![elem; len]`
++error: initializing a reference-counted pointer in `vec![elem; len]`
+ --> $DIR/rc.rs:8:13
+ |
+LL | let v = vec![Rc::new("x".to_string()); 2];
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: `-D clippy::rc-clone-in-vec-init` implied by `-D warnings`
+ = note: each element will point to the same `Rc` instance
+help: consider initializing each `Rc` element individually
+ |
+LL ~ let v = {
+LL + let mut v = Vec::with_capacity(2);
- LL + (0..2).for_each(|_| v.push(Rc::new("x".to_string())));
++LL + (0..2).for_each(|_| v.push(Rc::new(..)));
+LL + v
+LL ~ };
+ |
+help: or if this is intentional, consider extracting the `Rc` initialization to a variable
+ |
+LL ~ let v = {
- LL + let data = Rc::new("x".to_string());
++LL + let data = Rc::new(..);
+LL + vec![data; 2]
+LL ~ };
+ |
+
- error: calling `Rc::new` in `vec![elem; len]`
++error: initializing a reference-counted pointer in `vec![elem; len]`
+ --> $DIR/rc.rs:16:21
+ |
+LL | let v = vec![Rc::new("x".to_string()); 2];
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: each element will point to the same `Rc` instance
+help: consider initializing each `Rc` element individually
+ |
+LL ~ let v = {
+LL + let mut v = Vec::with_capacity(2);
- LL + (0..2).for_each(|_| v.push(Rc::new("x".to_string())));
++LL + (0..2).for_each(|_| v.push(Rc::new(..)));
+LL + v
+LL ~ };
+ |
+help: or if this is intentional, consider extracting the `Rc` initialization to a variable
+ |
+LL ~ let v = {
- LL + let data = Rc::new("x".to_string());
++LL + let data = Rc::new(..);
+LL + vec![data; 2]
+LL ~ };
+ |
+
- error: calling `Rc::new` in `vec![elem; len]`
++error: initializing a reference-counted pointer in `vec![elem; len]`
+ --> $DIR/rc.rs:22:13
+ |
+LL | let v = vec![
+ | _____________^
+LL | | std::rc::Rc::new(Mutex::new({
+LL | | let x = 1;
+LL | | dbg!(x);
+... |
+LL | | 2
+LL | | ];
+ | |_____^
+ |
+ = note: each element will point to the same `Rc` instance
+help: consider initializing each `Rc` element individually
+ |
+LL ~ let v = {
+LL + let mut v = Vec::with_capacity(2);
+LL + (0..2).for_each(|_| v.push(std::rc::Rc::new(..)));
+LL + v
+LL ~ };
+ |
+help: or if this is intentional, consider extracting the `Rc` initialization to a variable
+ |
+LL ~ let v = {
+LL + let data = std::rc::Rc::new(..);
+LL + vec![data; 2]
+LL ~ };
+ |
+
- error: calling `Rc::new` in `vec![elem; len]`
++error: initializing a reference-counted pointer in `vec![elem; len]`
+ --> $DIR/rc.rs:31:14
+ |
+LL | let v1 = vec![
+ | ______________^
+LL | | Rc::new(Mutex::new({
+LL | | let x = 1;
+LL | | dbg!(x);
+... |
+LL | | 2
+LL | | ];
+ | |_____^
+ |
+ = note: each element will point to the same `Rc` instance
+help: consider initializing each `Rc` element individually
+ |
+LL ~ let v1 = {
+LL + let mut v = Vec::with_capacity(2);
+LL + (0..2).for_each(|_| v.push(Rc::new(..)));
+LL + v
+LL ~ };
+ |
+help: or if this is intentional, consider extracting the `Rc` initialization to a variable
+ |
+LL ~ let v1 = {
+LL + let data = Rc::new(..);
+LL + vec![data; 2]
+LL ~ };
+ |
+
+error: aborting due to 4 previous errors
+
--- /dev/null
--- /dev/null
++#![warn(clippy::rc_clone_in_vec_init)]
++use std::rc::{Rc, Weak as UnSyncWeak};
++use std::sync::{Arc, Mutex, Weak as SyncWeak};
++
++fn main() {}
++
++fn should_warn_simple_case() {
++ let v = vec![SyncWeak::<u32>::new(); 2];
++ let v2 = vec![UnSyncWeak::<u32>::new(); 2];
++
++ let v = vec![Rc::downgrade(&Rc::new("x".to_string())); 2];
++ let v = vec![Arc::downgrade(&Arc::new("x".to_string())); 2];
++}
++
++fn should_warn_simple_case_with_big_indentation() {
++ if true {
++ let k = 1;
++ dbg!(k);
++ if true {
++ let v = vec![Arc::downgrade(&Arc::new("x".to_string())); 2];
++ let v2 = vec![Rc::downgrade(&Rc::new("x".to_string())); 2];
++ }
++ }
++}
++
++fn should_warn_complex_case() {
++ let v = vec![
++ Arc::downgrade(&Arc::new(Mutex::new({
++ let x = 1;
++ dbg!(x);
++ x
++ })));
++ 2
++ ];
++
++ let v1 = vec![
++ Rc::downgrade(&Rc::new(Mutex::new({
++ let x = 1;
++ dbg!(x);
++ x
++ })));
++ 2
++ ];
++}
++
++fn should_not_warn_custom_weak() {
++ #[derive(Clone)]
++ struct Weak;
++
++ impl Weak {
++ fn new() -> Self {
++ Weak
++ }
++ }
++
++ let v = vec![Weak::new(); 2];
++}
++
++fn should_not_warn_vec_from_elem_but_not_weak() {
++ let v = vec![String::new(); 2];
++ let v1 = vec![1; 2];
++ let v2 = vec![
++ Box::new(Arc::downgrade(&Arc::new({
++ let y = 3;
++ dbg!(y);
++ y
++ })));
++ 2
++ ];
++ let v3 = vec![
++ Box::new(Rc::downgrade(&Rc::new({
++ let y = 3;
++ dbg!(y);
++ y
++ })));
++ 2
++ ];
++}
++
++fn should_not_warn_vec_macro_but_not_from_elem() {
++ let v = vec![Arc::downgrade(&Arc::new("x".to_string()))];
++ let v = vec![Rc::downgrade(&Rc::new("x".to_string()))];
++}
--- /dev/null
--- /dev/null
++error: initializing a reference-counted pointer in `vec![elem; len]`
++ --> $DIR/weak.rs:8:13
++ |
++LL | let v = vec![SyncWeak::<u32>::new(); 2];
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++ |
++ = note: `-D clippy::rc-clone-in-vec-init` implied by `-D warnings`
++ = note: each element will point to the same `Weak` instance
++help: consider initializing each `Weak` element individually
++ |
++LL ~ let v = {
++LL + let mut v = Vec::with_capacity(2);
++LL + (0..2).for_each(|_| v.push(SyncWeak::<u32>::new(..)));
++LL + v
++LL ~ };
++ |
++help: or if this is intentional, consider extracting the `Weak` initialization to a variable
++ |
++LL ~ let v = {
++LL + let data = SyncWeak::<u32>::new(..);
++LL + vec![data; 2]
++LL ~ };
++ |
++
++error: initializing a reference-counted pointer in `vec![elem; len]`
++ --> $DIR/weak.rs:9:14
++ |
++LL | let v2 = vec![UnSyncWeak::<u32>::new(); 2];
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++ |
++ = note: each element will point to the same `Weak` instance
++help: consider initializing each `Weak` element individually
++ |
++LL ~ let v2 = {
++LL + let mut v = Vec::with_capacity(2);
++LL + (0..2).for_each(|_| v.push(UnSyncWeak::<u32>::new(..)));
++LL + v
++LL ~ };
++ |
++help: or if this is intentional, consider extracting the `Weak` initialization to a variable
++ |
++LL ~ let v2 = {
++LL + let data = UnSyncWeak::<u32>::new(..);
++LL + vec![data; 2]
++LL ~ };
++ |
++
++error: initializing a reference-counted pointer in `vec![elem; len]`
++ --> $DIR/weak.rs:11:13
++ |
++LL | let v = vec![Rc::downgrade(&Rc::new("x".to_string())); 2];
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++ |
++ = note: each element will point to the same `Weak` instance
++help: consider initializing each `Weak` element individually
++ |
++LL ~ let v = {
++LL + let mut v = Vec::with_capacity(2);
++LL + (0..2).for_each(|_| v.push(Rc::downgrade(..)));
++LL + v
++LL ~ };
++ |
++help: or if this is intentional, consider extracting the `Weak` initialization to a variable
++ |
++LL ~ let v = {
++LL + let data = Rc::downgrade(..);
++LL + vec![data; 2]
++LL ~ };
++ |
++
++error: initializing a reference-counted pointer in `vec![elem; len]`
++ --> $DIR/weak.rs:12:13
++ |
++LL | let v = vec![Arc::downgrade(&Arc::new("x".to_string())); 2];
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++ |
++ = note: each element will point to the same `Weak` instance
++help: consider initializing each `Weak` element individually
++ |
++LL ~ let v = {
++LL + let mut v = Vec::with_capacity(2);
++LL + (0..2).for_each(|_| v.push(Arc::downgrade(..)));
++LL + v
++LL ~ };
++ |
++help: or if this is intentional, consider extracting the `Weak` initialization to a variable
++ |
++LL ~ let v = {
++LL + let data = Arc::downgrade(..);
++LL + vec![data; 2]
++LL ~ };
++ |
++
++error: initializing a reference-counted pointer in `vec![elem; len]`
++ --> $DIR/weak.rs:20:21
++ |
++LL | let v = vec![Arc::downgrade(&Arc::new("x".to_string())); 2];
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++ |
++ = note: each element will point to the same `Weak` instance
++help: consider initializing each `Weak` element individually
++ |
++LL ~ let v = {
++LL + let mut v = Vec::with_capacity(2);
++LL + (0..2).for_each(|_| v.push(Arc::downgrade(..)));
++LL + v
++LL ~ };
++ |
++help: or if this is intentional, consider extracting the `Weak` initialization to a variable
++ |
++LL ~ let v = {
++LL + let data = Arc::downgrade(..);
++LL + vec![data; 2]
++LL ~ };
++ |
++
++error: initializing a reference-counted pointer in `vec![elem; len]`
++ --> $DIR/weak.rs:21:22
++ |
++LL | let v2 = vec![Rc::downgrade(&Rc::new("x".to_string())); 2];
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++ |
++ = note: each element will point to the same `Weak` instance
++help: consider initializing each `Weak` element individually
++ |
++LL ~ let v2 = {
++LL + let mut v = Vec::with_capacity(2);
++LL + (0..2).for_each(|_| v.push(Rc::downgrade(..)));
++LL + v
++LL ~ };
++ |
++help: or if this is intentional, consider extracting the `Weak` initialization to a variable
++ |
++LL ~ let v2 = {
++LL + let data = Rc::downgrade(..);
++LL + vec![data; 2]
++LL ~ };
++ |
++
++error: initializing a reference-counted pointer in `vec![elem; len]`
++ --> $DIR/weak.rs:27:13
++ |
++LL | let v = vec![
++ | _____________^
++LL | | Arc::downgrade(&Arc::new(Mutex::new({
++LL | | let x = 1;
++LL | | dbg!(x);
++... |
++LL | | 2
++LL | | ];
++ | |_____^
++ |
++ = note: each element will point to the same `Weak` instance
++help: consider initializing each `Weak` element individually
++ |
++LL ~ let v = {
++LL + let mut v = Vec::with_capacity(2);
++LL + (0..2).for_each(|_| v.push(Arc::downgrade(..)));
++LL + v
++LL ~ };
++ |
++help: or if this is intentional, consider extracting the `Weak` initialization to a variable
++ |
++LL ~ let v = {
++LL + let data = Arc::downgrade(..);
++LL + vec![data; 2]
++LL ~ };
++ |
++
++error: initializing a reference-counted pointer in `vec![elem; len]`
++ --> $DIR/weak.rs:36:14
++ |
++LL | let v1 = vec![
++ | ______________^
++LL | | Rc::downgrade(&Rc::new(Mutex::new({
++LL | | let x = 1;
++LL | | dbg!(x);
++... |
++LL | | 2
++LL | | ];
++ | |_____^
++ |
++ = note: each element will point to the same `Weak` instance
++help: consider initializing each `Weak` element individually
++ |
++LL ~ let v1 = {
++LL + let mut v = Vec::with_capacity(2);
++LL + (0..2).for_each(|_| v.push(Rc::downgrade(..)));
++LL + v
++LL ~ };
++ |
++help: or if this is intentional, consider extracting the `Weak` initialization to a variable
++ |
++LL ~ let v1 = {
++LL + let data = Rc::downgrade(..);
++LL + vec![data; 2]
++LL ~ };
++ |
++
++error: aborting due to 8 previous errors
++
--- /dev/null
- clippy::deref_addrof
+#![warn(clippy::recursive_format_impl)]
+#![allow(
+ clippy::inherent_to_string_shadow_display,
+ clippy::to_string_in_format_args,
++ clippy::deref_addrof,
++ clippy::borrow_deref_ref
+)]
+
+use std::fmt;
+
+struct A;
+impl A {
+ fn fmt(&self) {
+ self.to_string();
+ }
+}
+
+trait B {
+ fn fmt(&self) {}
+}
+
+impl B for A {
+ fn fmt(&self) {
+ self.to_string();
+ }
+}
+
+impl fmt::Display for A {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ write!(f, "{}", self.to_string())
+ }
+}
+
+fn fmt(a: A) {
+ a.to_string();
+}
+
+struct C;
+
+impl C {
+ // Doesn't trigger if to_string defined separately
+ // i.e. not using ToString trait (from Display)
+ fn to_string(&self) -> String {
+ String::from("I am C")
+ }
+}
+
+impl fmt::Display for C {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ write!(f, "{}", self.to_string())
+ }
+}
+
+enum D {
+ E(String),
+ F,
+}
+
+impl std::fmt::Display for D {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ match &self {
+ Self::E(string) => write!(f, "E {}", string.to_string()),
+ Self::F => write!(f, "F"),
+ }
+ }
+}
+
+// Check for use of self as Display, in Display impl
+// Triggers on direct use of self
+struct G;
+
+impl std::fmt::Display for G {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ write!(f, "{}", self)
+ }
+}
+
+// Triggers on reference to self
+struct H;
+
+impl std::fmt::Display for H {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ write!(f, "{}", &self)
+ }
+}
+
+impl std::fmt::Debug for H {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ write!(f, "{:?}", &self)
+ }
+}
+
+// Triggers on multiple reference to self
+struct H2;
+
+impl std::fmt::Display for H2 {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ write!(f, "{}", &&&self)
+ }
+}
+
+// Doesn't trigger on correct deref
+struct I;
+
+impl std::ops::Deref for I {
+ type Target = str;
+
+ fn deref(&self) -> &Self::Target {
+ "test"
+ }
+}
+
+impl std::fmt::Display for I {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{}", &**self)
+ }
+}
+
+impl std::fmt::Debug for I {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{:?}", &**self)
+ }
+}
+
+// Doesn't trigger on multiple correct deref
+struct I2;
+
+impl std::ops::Deref for I2 {
+ type Target = str;
+
+ fn deref(&self) -> &Self::Target {
+ "test"
+ }
+}
+
+impl std::fmt::Display for I2 {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{}", **&&&**self)
+ }
+}
+
+// Doesn't trigger on multiple correct deref
+struct I3;
+
+impl std::ops::Deref for I3 {
+ type Target = str;
+
+ fn deref(&self) -> &Self::Target {
+ "test"
+ }
+}
+
+impl std::fmt::Display for I3 {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{}", &&**&&&**self)
+ }
+}
+
+// Does trigger when deref resolves to self
+struct J;
+
+impl std::ops::Deref for J {
+ type Target = str;
+
+ fn deref(&self) -> &Self::Target {
+ "test"
+ }
+}
+
+impl std::fmt::Display for J {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{}", &*self)
+ }
+}
+
+impl std::fmt::Debug for J {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{:?}", &*self)
+ }
+}
+
+struct J2;
+
+impl std::ops::Deref for J2 {
+ type Target = str;
+
+ fn deref(&self) -> &Self::Target {
+ "test"
+ }
+}
+
+impl std::fmt::Display for J2 {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{}", *self)
+ }
+}
+
+struct J3;
+
+impl std::ops::Deref for J3 {
+ type Target = str;
+
+ fn deref(&self) -> &Self::Target {
+ "test"
+ }
+}
+
+impl std::fmt::Display for J3 {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{}", **&&*self)
+ }
+}
+
+struct J4;
+
+impl std::ops::Deref for J4 {
+ type Target = str;
+
+ fn deref(&self) -> &Self::Target {
+ "test"
+ }
+}
+
+impl std::fmt::Display for J4 {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{}", &&**&&*self)
+ }
+}
+
+// Doesn't trigger on Debug from Display
+struct K;
+
+impl std::fmt::Debug for K {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "test")
+ }
+}
+
+impl std::fmt::Display for K {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{:?}", self)
+ }
+}
+
+// Doesn't trigger on Display from Debug
+struct K2;
+
+impl std::fmt::Debug for K2 {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{}", self)
+ }
+}
+
+impl std::fmt::Display for K2 {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "test")
+ }
+}
+
+// Doesn't trigger on struct fields
+struct L {
+ field1: u32,
+ field2: i32,
+}
+
+impl std::fmt::Display for L {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{},{}", self.field1, self.field2)
+ }
+}
+
+impl std::fmt::Debug for L {
+ fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+ write!(f, "{:?},{:?}", self.field1, self.field2)
+ }
+}
+
+// Doesn't trigger on nested enum matching
+enum Tree {
+ Leaf,
+ Node(Vec<Tree>),
+}
+
+impl std::fmt::Display for Tree {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Tree::Leaf => write!(f, "*"),
+ Tree::Node(children) => {
+ write!(f, "(")?;
+ for child in children.iter() {
+ write!(f, "{},", child)?;
+ }
+ write!(f, ")")
+ },
+ }
+ }
+}
+
+impl std::fmt::Debug for Tree {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Tree::Leaf => write!(f, "*"),
+ Tree::Node(children) => {
+ write!(f, "(")?;
+ for child in children.iter() {
+ write!(f, "{:?},", child)?;
+ }
+ write!(f, ")")
+ },
+ }
+ }
+}
+
+fn main() {
+ let a = A;
+ a.to_string();
+ a.fmt();
+ fmt(a);
+
+ let c = C;
+ c.to_string();
+}
--- /dev/null
- --> $DIR/recursive_format_impl.rs:29:25
+error: using `self.to_string` in `fmt::Display` implementation will cause infinite recursion
- --> $DIR/recursive_format_impl.rs:73:9
++ --> $DIR/recursive_format_impl.rs:30:25
+ |
+LL | write!(f, "{}", self.to_string())
+ | ^^^^^^^^^^^^^^^^
+ |
+ = note: `-D clippy::recursive-format-impl` implied by `-D warnings`
+
+error: using `self` as `Display` in `impl Display` will cause infinite recursion
- --> $DIR/recursive_format_impl.rs:82:9
++ --> $DIR/recursive_format_impl.rs:74:9
+ |
+LL | write!(f, "{}", self)
+ | ^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: this error originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: using `self` as `Display` in `impl Display` will cause infinite recursion
- --> $DIR/recursive_format_impl.rs:88:9
++ --> $DIR/recursive_format_impl.rs:83:9
+ |
+LL | write!(f, "{}", &self)
+ | ^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: this error originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: using `self` as `Debug` in `impl Debug` will cause infinite recursion
- --> $DIR/recursive_format_impl.rs:97:9
++ --> $DIR/recursive_format_impl.rs:89:9
+ |
+LL | write!(f, "{:?}", &self)
+ | ^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: this error originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: using `self` as `Display` in `impl Display` will cause infinite recursion
- --> $DIR/recursive_format_impl.rs:171:9
++ --> $DIR/recursive_format_impl.rs:98:9
+ |
+LL | write!(f, "{}", &&&self)
+ | ^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: this error originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: using `self` as `Display` in `impl Display` will cause infinite recursion
- --> $DIR/recursive_format_impl.rs:177:9
++ --> $DIR/recursive_format_impl.rs:172:9
+ |
+LL | write!(f, "{}", &*self)
+ | ^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: this error originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: using `self` as `Debug` in `impl Debug` will cause infinite recursion
- --> $DIR/recursive_format_impl.rs:193:9
++ --> $DIR/recursive_format_impl.rs:178:9
+ |
+LL | write!(f, "{:?}", &*self)
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: this error originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: using `self` as `Display` in `impl Display` will cause infinite recursion
- --> $DIR/recursive_format_impl.rs:209:9
++ --> $DIR/recursive_format_impl.rs:194:9
+ |
+LL | write!(f, "{}", *self)
+ | ^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: this error originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: using `self` as `Display` in `impl Display` will cause infinite recursion
- --> $DIR/recursive_format_impl.rs:225:9
++ --> $DIR/recursive_format_impl.rs:210:9
+ |
+LL | write!(f, "{}", **&&*self)
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: this error originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: using `self` as `Display` in `impl Display` will cause infinite recursion
++ --> $DIR/recursive_format_impl.rs:226:9
+ |
+LL | write!(f, "{}", &&**&&*self)
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: this error originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 10 previous errors
+
--- /dev/null
+#![warn(clippy::shadow_same, clippy::shadow_reuse, clippy::shadow_unrelated)]
+#![allow(clippy::let_unit_value)]
+
+fn shadow_same() {
+ let x = 1;
+ let x = x;
+ let mut x = &x;
+ let x = &mut x;
+ let x = *x;
+}
+
+fn shadow_reuse() -> Option<()> {
+ let x = ([[0]], ());
+ let x = x.0;
+ let x = x[0];
+ let [x] = x;
+ let x = Some(x);
+ let x = foo(x);
+ let x = || x;
+ let x = Some(1).map(|_| x)?;
+ let y = 1;
+ let y = match y {
+ 1 => 2,
+ _ => 3,
+ };
+ None
+}
+
+fn shadow_unrelated() {
+ let x = 1;
+ let x = 2;
+}
+
+fn syntax() {
+ fn f(x: u32) {
+ let x = 1;
+ }
+ let x = 1;
+ match Some(1) {
+ Some(1) => {},
+ Some(x) => {
+ let x = 1;
+ },
+ _ => {},
+ }
+ if let Some(x) = Some(1) {}
+ while let Some(x) = Some(1) {}
+ let _ = |[x]: [u32; 1]| {
+ let x = 1;
+ };
+ let y = Some(1);
+ if let Some(y) = y {}
+}
+
+fn negative() {
+ match Some(1) {
+ Some(x) if x == 1 => {},
+ Some(x) => {},
+ None => {},
+ }
+ match [None, Some(1)] {
+ [Some(x), None] | [None, Some(x)] => {},
+ _ => {},
+ }
+ if let Some(x) = Some(1) {
+ let y = 1;
+ } else {
+ let x = 1;
+ let y = 1;
+ }
+ let x = 1;
+ #[allow(clippy::shadow_unrelated)]
+ let x = 1;
+}
+
+fn foo<T>(_: T) {}
+
+fn question_mark() -> Option<()> {
+ let val = 1;
+ // `?` expands with a `val` binding
+ None?;
+ None
+}
+
+pub async fn foo1(_a: i32) {}
+
+pub async fn foo2(_a: i32, _b: i64) {
+ let _b = _a;
+}
+
++fn ice_8748() {
++ let _ = [0; {
++ let x = 1;
++ if let Some(x) = Some(1) { x } else { 1 }
++ }];
++}
++
+fn main() {}
--- /dev/null
+// FIXME: Ideally these suggestions would be fixed via rustfix. Blocked by rust-lang/rust#53934
+// // run-rustfix
+
+#![warn(clippy::significant_drop_in_scrutinee)]
+#![allow(clippy::single_match)]
+#![allow(clippy::match_single_binding)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+
++use std::num::ParseIntError;
+use std::ops::Deref;
+use std::sync::atomic::{AtomicU64, Ordering};
++use std::sync::RwLock;
+use std::sync::{Mutex, MutexGuard};
+
+struct State {}
+
+impl State {
+ fn foo(&self) -> bool {
+ true
+ }
+
+ fn bar(&self) {}
+}
+
+fn should_not_trigger_lint_with_mutex_guard_outside_match() {
+ let mutex = Mutex::new(State {});
+
+ // Should not trigger lint because the temporary should drop at the `;` on line before the match
+ let is_foo = mutex.lock().unwrap().foo();
+ match is_foo {
+ true => {
+ mutex.lock().unwrap().bar();
+ },
+ false => {},
+ };
+}
+
+fn should_not_trigger_lint_with_mutex_guard_when_taking_ownership_in_match() {
+ let mutex = Mutex::new(State {});
+
+ // Should not trigger lint because the scrutinee is explicitly returning the MutexGuard,
+ // so its lifetime should not be surprising.
+ match mutex.lock() {
+ Ok(guard) => {
+ guard.foo();
+ mutex.lock().unwrap().bar();
+ },
+ _ => {},
+ };
+}
+
+fn should_trigger_lint_with_mutex_guard_in_match_scrutinee() {
+ let mutex = Mutex::new(State {});
+
+ // Should trigger lint because the lifetime of the temporary MutexGuard is surprising because it
+ // is preserved until the end of the match, but there is no clear indication that this is the
+ // case.
+ match mutex.lock().unwrap().foo() {
+ true => {
+ mutex.lock().unwrap().bar();
+ },
+ false => {},
+ };
+}
+
+fn should_not_trigger_lint_for_insignificant_drop() {
+ // Should not trigger lint because there are no temporaries whose drops have a significant
+ // side effect.
+ match 1u64.to_string().is_empty() {
+ true => {
+ println!("It was empty")
+ },
+ false => {
+ println!("It was not empty")
+ },
+ }
+}
+
+struct StateWithMutex {
+ m: Mutex<u64>,
+}
+
+struct MutexGuardWrapper<'a> {
+ mg: MutexGuard<'a, u64>,
+}
+
+impl<'a> MutexGuardWrapper<'a> {
+ fn get_the_value(&self) -> u64 {
+ *self.mg.deref()
+ }
+}
+
+struct MutexGuardWrapperWrapper<'a> {
+ mg: MutexGuardWrapper<'a>,
+}
+
+impl<'a> MutexGuardWrapperWrapper<'a> {
+ fn get_the_value(&self) -> u64 {
+ *self.mg.mg.deref()
+ }
+}
+
+impl StateWithMutex {
+ fn lock_m(&self) -> MutexGuardWrapper<'_> {
+ MutexGuardWrapper {
+ mg: self.m.lock().unwrap(),
+ }
+ }
+
+ fn lock_m_m(&self) -> MutexGuardWrapperWrapper<'_> {
+ MutexGuardWrapperWrapper {
+ mg: MutexGuardWrapper {
+ mg: self.m.lock().unwrap(),
+ },
+ }
+ }
+
+ fn foo(&self) -> bool {
+ true
+ }
+
+ fn bar(&self) {}
+}
+
+fn should_trigger_lint_with_wrapped_mutex() {
+ let s = StateWithMutex { m: Mutex::new(1) };
+
+ // Should trigger lint because a temporary contains a type with a significant drop and its
+ // lifetime is not obvious. Additionally, it is not obvious from looking at the scrutinee that
+ // the temporary contains such a type, making it potentially even more surprising.
+ match s.lock_m().get_the_value() {
+ 1 => {
+ println!("Got 1. Is it still 1?");
+ println!("{}", s.lock_m().get_the_value());
+ },
+ 2 => {
+ println!("Got 2. Is it still 2?");
+ println!("{}", s.lock_m().get_the_value());
+ },
+ _ => {},
+ }
+ println!("All done!");
+}
+
+fn should_trigger_lint_with_double_wrapped_mutex() {
+ let s = StateWithMutex { m: Mutex::new(1) };
+
+ // Should trigger lint because a temporary contains a type which further contains a type with a
+ // significant drop and its lifetime is not obvious. Additionally, it is not obvious from
+ // looking at the scrutinee that the temporary contains such a type, making it potentially even
+ // more surprising.
+ match s.lock_m_m().get_the_value() {
+ 1 => {
+ println!("Got 1. Is it still 1?");
+ println!("{}", s.lock_m().get_the_value());
+ },
+ 2 => {
+ println!("Got 2. Is it still 2?");
+ println!("{}", s.lock_m().get_the_value());
+ },
+ _ => {},
+ }
+ println!("All done!");
+}
+
+struct Counter {
+ i: AtomicU64,
+}
+
+#[clippy::has_significant_drop]
+struct CounterWrapper<'a> {
+ counter: &'a Counter,
+}
+
+impl<'a> CounterWrapper<'a> {
+ fn new(counter: &Counter) -> CounterWrapper {
+ counter.i.fetch_add(1, Ordering::Relaxed);
+ CounterWrapper { counter }
+ }
+}
+
+impl<'a> Drop for CounterWrapper<'a> {
+ fn drop(&mut self) {
+ self.counter.i.fetch_sub(1, Ordering::Relaxed);
+ }
+}
+
+impl Counter {
+ fn temp_increment(&self) -> Vec<CounterWrapper> {
+ vec![CounterWrapper::new(self), CounterWrapper::new(self)]
+ }
+}
+
+fn should_trigger_lint_for_vec() {
+ let counter = Counter { i: AtomicU64::new(0) };
+
+ // Should trigger lint because the temporary in the scrutinee returns a collection of types
+ // which have significant drops. The types with significant drops are also non-obvious when
+ // reading the expression in the scrutinee.
+ match counter.temp_increment().len() {
+ 2 => {
+ let current_count = counter.i.load(Ordering::Relaxed);
+ println!("Current count {}", current_count);
+ assert_eq!(current_count, 0);
+ },
+ 1 => {},
+ 3 => {},
+ _ => {},
+ };
+}
+
+struct StateWithField {
+ s: String,
+}
+
+// Should trigger lint only on the type in the tuple which is created using a temporary
+// with a significant drop. Additionally, this test ensures that the format of the tuple
+// is preserved correctly in the suggestion.
+fn should_trigger_lint_for_tuple_in_scrutinee() {
+ let mutex1 = Mutex::new(StateWithField { s: "one".to_owned() });
+
+ {
+ match (mutex1.lock().unwrap().s.len(), true) {
+ (3, _) => {
+ println!("started");
+ mutex1.lock().unwrap().s.len();
+ println!("done");
+ },
+ (_, _) => {},
+ };
+
+ match (true, mutex1.lock().unwrap().s.len(), true) {
+ (_, 3, _) => {
+ println!("started");
+ mutex1.lock().unwrap().s.len();
+ println!("done");
+ },
+ (_, _, _) => {},
+ };
+
+ let mutex2 = Mutex::new(StateWithField { s: "two".to_owned() });
+ match (mutex1.lock().unwrap().s.len(), true, mutex2.lock().unwrap().s.len()) {
+ (3, _, 3) => {
+ println!("started");
+ mutex1.lock().unwrap().s.len();
+ mutex2.lock().unwrap().s.len();
+ println!("done");
+ },
+ (_, _, _) => {},
+ };
+
+ let mutex3 = Mutex::new(StateWithField { s: "three".to_owned() });
+ match mutex3.lock().unwrap().s.as_str() {
+ "three" => {
+ println!("started");
+ mutex1.lock().unwrap().s.len();
+ mutex2.lock().unwrap().s.len();
+ println!("done");
+ },
+ _ => {},
+ };
+
+ match (true, mutex3.lock().unwrap().s.as_str()) {
+ (_, "three") => {
+ println!("started");
+ mutex1.lock().unwrap().s.len();
+ mutex2.lock().unwrap().s.len();
+ println!("done");
+ },
+ (_, _) => {},
+ };
+ }
+}
+
+// Should trigger lint when either side of a binary operation creates a temporary with a
+// significant drop.
+// To avoid potential unnecessary copies or creating references that would trigger the significant
+// drop problem, the lint recommends moving the entire binary operation.
+fn should_trigger_lint_for_accessing_field_in_mutex_in_one_side_of_binary_op() {
+ let mutex = Mutex::new(StateWithField { s: "state".to_owned() });
+
+ match mutex.lock().unwrap().s.len() > 1 {
+ true => {
+ mutex.lock().unwrap().s.len();
+ },
+ false => {},
+ };
+
+ match 1 < mutex.lock().unwrap().s.len() {
+ true => {
+ mutex.lock().unwrap().s.len();
+ },
+ false => {},
+ };
+}
+
+// Should trigger lint when both sides of a binary operation creates a temporary with a
+// significant drop.
+// To avoid potential unnecessary copies or creating references that would trigger the significant
+// drop problem, the lint recommends moving the entire binary operation.
+fn should_trigger_lint_for_accessing_fields_in_mutex_in_both_sides_of_binary_op() {
+ let mutex1 = Mutex::new(StateWithField { s: "state".to_owned() });
+ let mutex2 = Mutex::new(StateWithField {
+ s: "statewithfield".to_owned(),
+ });
+
+ match mutex1.lock().unwrap().s.len() < mutex2.lock().unwrap().s.len() {
+ true => {
+ println!(
+ "{} < {}",
+ mutex1.lock().unwrap().s.len(),
+ mutex2.lock().unwrap().s.len()
+ );
+ },
+ false => {},
+ };
+
+ match mutex1.lock().unwrap().s.len() >= mutex2.lock().unwrap().s.len() {
+ true => {
+ println!(
+ "{} >= {}",
+ mutex1.lock().unwrap().s.len(),
+ mutex2.lock().unwrap().s.len()
+ );
+ },
+ false => {},
+ };
+}
+
+fn should_not_trigger_lint_for_closure_in_scrutinee() {
+ let mutex1 = Mutex::new(StateWithField { s: "one".to_owned() });
+
+ let get_mutex_guard = || mutex1.lock().unwrap().s.len();
+
+ // Should not trigger lint because the temporary with a significant drop will be dropped
+ // at the end of the closure, so the MutexGuard will be unlocked and not have a potentially
+ // surprising lifetime.
+ match get_mutex_guard() > 1 {
+ true => {
+ mutex1.lock().unwrap().s.len();
+ },
+ false => {},
+ };
+}
+
+fn should_trigger_lint_for_return_from_closure_in_scrutinee() {
+ let mutex1 = Mutex::new(StateWithField { s: "one".to_owned() });
+
+ let get_mutex_guard = || mutex1.lock().unwrap();
+
+ // Should trigger lint because the temporary with a significant drop is returned from the
+ // closure but not used directly in any match arms, so it has a potentially surprising lifetime.
+ match get_mutex_guard().s.len() > 1 {
+ true => {
+ mutex1.lock().unwrap().s.len();
+ },
+ false => {},
+ };
+}
+
+fn should_trigger_lint_for_return_from_match_in_scrutinee() {
+ let mutex1 = Mutex::new(StateWithField { s: "one".to_owned() });
+ let mutex2 = Mutex::new(StateWithField { s: "two".to_owned() });
+
+ let i = 100;
+
+ // Should trigger lint because the nested match within the scrutinee returns a temporary with a
+ // significant drop is but not used directly in any match arms, so it has a potentially
+ // surprising lifetime.
+ match match i {
+ 100 => mutex1.lock().unwrap(),
+ _ => mutex2.lock().unwrap(),
+ }
+ .s
+ .len()
+ > 1
+ {
+ true => {
+ mutex1.lock().unwrap().s.len();
+ },
+ false => {
+ println!("nothing to do here");
+ },
+ };
+}
+
+fn should_trigger_lint_for_return_from_if_in_scrutinee() {
+ let mutex1 = Mutex::new(StateWithField { s: "one".to_owned() });
+ let mutex2 = Mutex::new(StateWithField { s: "two".to_owned() });
+
+ let i = 100;
+
+ // Should trigger lint because the nested if-expression within the scrutinee returns a temporary
+ // with a significant drop is but not used directly in any match arms, so it has a potentially
+ // surprising lifetime.
+ match if i > 1 {
+ mutex1.lock().unwrap()
+ } else {
+ mutex2.lock().unwrap()
+ }
+ .s
+ .len()
+ > 1
+ {
+ true => {
+ mutex1.lock().unwrap().s.len();
+ },
+ false => {},
+ };
+}
+
+fn should_not_trigger_lint_for_if_in_scrutinee() {
+ let mutex = Mutex::new(StateWithField { s: "state".to_owned() });
+
+ let i = 100;
+
+ // Should not trigger the lint because the temporary with a significant drop *is* dropped within
+ // the body of the if-expression nested within the match scrutinee, and therefore does not have
+ // a potentially surprising lifetime.
+ match if i > 1 {
+ mutex.lock().unwrap().s.len() > 1
+ } else {
+ false
+ } {
+ true => {
+ mutex.lock().unwrap().s.len();
+ },
+ false => {},
+ };
+}
+
+struct StateWithBoxedMutexGuard {
+ u: Mutex<u64>,
+}
+
+impl StateWithBoxedMutexGuard {
+ fn new() -> StateWithBoxedMutexGuard {
+ StateWithBoxedMutexGuard { u: Mutex::new(42) }
+ }
+ fn lock(&self) -> Box<MutexGuard<u64>> {
+ Box::new(self.u.lock().unwrap())
+ }
+}
+
+fn should_trigger_lint_for_boxed_mutex_guard() {
+ let s = StateWithBoxedMutexGuard::new();
+
+ // Should trigger lint because a temporary Box holding a type with a significant drop in a match
+ // scrutinee may have a potentially surprising lifetime.
+ match s.lock().deref().deref() {
+ 0 | 1 => println!("Value was less than 2"),
+ _ => println!("Value is {}", s.lock().deref()),
+ };
+}
+
+struct StateStringWithBoxedMutexGuard {
+ s: Mutex<String>,
+}
+
+impl StateStringWithBoxedMutexGuard {
+ fn new() -> StateStringWithBoxedMutexGuard {
+ StateStringWithBoxedMutexGuard {
+ s: Mutex::new("A String".to_owned()),
+ }
+ }
+ fn lock(&self) -> Box<MutexGuard<String>> {
+ Box::new(self.s.lock().unwrap())
+ }
+}
+
+fn should_trigger_lint_for_boxed_mutex_guard_holding_string() {
+ let s = StateStringWithBoxedMutexGuard::new();
+
+ let matcher = String::from("A String");
+
+ // Should trigger lint because a temporary Box holding a type with a significant drop in a match
+ // scrutinee may have a potentially surprising lifetime.
+ match s.lock().deref().deref() {
+ matcher => println!("Value is {}", s.lock().deref()),
+ _ => println!("Value was not a match"),
+ };
+}
+
+struct StateWithIntField {
+ i: u64,
+}
+
+// Should trigger lint when either side of an assign expression contains a temporary with a
+// significant drop, because the temporary's lifetime will be extended to the end of the match.
+// To avoid potential unnecessary copies or creating references that would trigger the significant
+// drop problem, the lint recommends moving the entire binary operation.
+fn should_trigger_lint_in_assign_expr() {
+ let mutex = Mutex::new(StateWithIntField { i: 10 });
+
+ let mut i = 100;
+
+ match mutex.lock().unwrap().i = i {
+ _ => {
+ println!("{}", mutex.lock().unwrap().i);
+ },
+ };
+
+ match i = mutex.lock().unwrap().i {
+ _ => {
+ println!("{}", mutex.lock().unwrap().i);
+ },
+ };
+
+ match mutex.lock().unwrap().i += 1 {
+ _ => {
+ println!("{}", mutex.lock().unwrap().i);
+ },
+ };
+
+ match i += mutex.lock().unwrap().i {
+ _ => {
+ println!("{}", mutex.lock().unwrap().i);
+ },
+ };
+}
+
+#[derive(Debug)]
+enum RecursiveEnum {
+ Foo(Option<Box<RecursiveEnum>>),
+}
+
+#[derive(Debug)]
+enum GenericRecursiveEnum<T> {
+ Foo(T, Option<Box<GenericRecursiveEnum<T>>>),
+}
+
+fn should_not_cause_stack_overflow() {
+ // Test that when a type recursively contains itself, a stack overflow does not occur when
+ // checking sub-types for significant drops.
+ let f = RecursiveEnum::Foo(Some(Box::new(RecursiveEnum::Foo(None))));
+ match f {
+ RecursiveEnum::Foo(Some(f)) => {
+ println!("{:?}", f)
+ },
+ RecursiveEnum::Foo(f) => {
+ println!("{:?}", f)
+ },
+ }
+
+ let f = GenericRecursiveEnum::Foo(1u64, Some(Box::new(GenericRecursiveEnum::Foo(2u64, None))));
+ match f {
+ GenericRecursiveEnum::Foo(i, Some(f)) => {
+ println!("{} {:?}", i, f)
+ },
+ GenericRecursiveEnum::Foo(i, f) => {
+ println!("{} {:?}", i, f)
+ },
+ }
+}
+
++fn should_not_produce_lint_for_try_desugar() -> Result<u64, ParseIntError> {
++ // TryDesugar (i.e. using `?` for a Result type) will turn into a match but is out of scope
++ // for this lint
++ let rwlock = RwLock::new("1".to_string());
++ let result = rwlock.read().unwrap().parse::<u64>()?;
++ println!("{}", result);
++ rwlock.write().unwrap().push('2');
++ Ok(result)
++}
++
++struct ResultReturner {
++ s: String,
++}
++
++impl ResultReturner {
++ fn to_number(&self) -> Result<i64, ParseIntError> {
++ self.s.parse::<i64>()
++ }
++}
++
++fn should_trigger_lint_for_non_ref_move_and_clone_suggestion() {
++ let rwlock = RwLock::<ResultReturner>::new(ResultReturner { s: "1".to_string() });
++ match rwlock.read().unwrap().to_number() {
++ Ok(n) => println!("Converted to number: {}", n),
++ Err(e) => println!("Could not convert {} to number", e),
++ };
++}
++
++fn should_trigger_lint_for_read_write_lock_for_loop() {
++ // For-in loops desugar to match expressions and are prone to the type of deadlock this lint is
++ // designed to look for.
++ let rwlock = RwLock::<Vec<String>>::new(vec!["1".to_string()]);
++ for s in rwlock.read().unwrap().iter() {
++ println!("{}", s);
++ }
++}
++
+fn main() {}
--- /dev/null
- --> $DIR/significant_drop_in_scrutinee.rs:57:11
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:130:11
++ --> $DIR/significant_drop_in_scrutinee.rs:59:11
+ |
+LL | match mutex.lock().unwrap().foo() {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: `-D clippy::significant-drop-in-scrutinee` implied by `-D warnings`
+help: try moving the temporary above the match
+ |
+LL ~ let value = mutex.lock().unwrap().foo();
+LL ~ match value {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:151:11
++ --> $DIR/significant_drop_in_scrutinee.rs:132:11
+ |
+LL | match s.lock_m().get_the_value() {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = s.lock_m().get_the_value();
+LL ~ match value {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:199:11
++ --> $DIR/significant_drop_in_scrutinee.rs:153:11
+ |
+LL | match s.lock_m_m().get_the_value() {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = s.lock_m_m().get_the_value();
+LL ~ match value {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:222:16
++ --> $DIR/significant_drop_in_scrutinee.rs:201:11
+ |
+LL | match counter.temp_increment().len() {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = counter.temp_increment().len();
+LL ~ match value {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:231:22
++ --> $DIR/significant_drop_in_scrutinee.rs:224:16
+ |
+LL | match (mutex1.lock().unwrap().s.len(), true) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = mutex1.lock().unwrap().s.len();
+LL ~ match (value, true) {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:241:16
++ --> $DIR/significant_drop_in_scrutinee.rs:233:22
+ |
+LL | match (true, mutex1.lock().unwrap().s.len(), true) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = mutex1.lock().unwrap().s.len();
+LL ~ match (true, value, true) {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:241:54
++ --> $DIR/significant_drop_in_scrutinee.rs:243:16
+ |
+LL | match (mutex1.lock().unwrap().s.len(), true, mutex2.lock().unwrap().s.len()) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = mutex1.lock().unwrap().s.len();
+LL ~ match (value, true, mutex2.lock().unwrap().s.len()) {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:252:15
++ --> $DIR/significant_drop_in_scrutinee.rs:243:54
+ |
+LL | match (mutex1.lock().unwrap().s.len(), true, mutex2.lock().unwrap().s.len()) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = mutex2.lock().unwrap().s.len();
+LL ~ match (mutex1.lock().unwrap().s.len(), true, value) {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:262:22
++ --> $DIR/significant_drop_in_scrutinee.rs:254:15
+ |
+LL | match mutex3.lock().unwrap().s.as_str() {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:281:11
++ --> $DIR/significant_drop_in_scrutinee.rs:264:22
+ |
+LL | match (true, mutex3.lock().unwrap().s.as_str()) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:288:11
++ --> $DIR/significant_drop_in_scrutinee.rs:283:11
+ |
+LL | match mutex.lock().unwrap().s.len() > 1 {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = mutex.lock().unwrap().s.len() > 1;
+LL ~ match value {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:306:11
++ --> $DIR/significant_drop_in_scrutinee.rs:290:11
+ |
+LL | match 1 < mutex.lock().unwrap().s.len() {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = 1 < mutex.lock().unwrap().s.len();
+LL ~ match value {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:317:11
++ --> $DIR/significant_drop_in_scrutinee.rs:308:11
+ |
+LL | match mutex1.lock().unwrap().s.len() < mutex2.lock().unwrap().s.len() {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = mutex1.lock().unwrap().s.len() < mutex2.lock().unwrap().s.len();
+LL ~ match value {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:352:11
++ --> $DIR/significant_drop_in_scrutinee.rs:319:11
+ |
+LL | match mutex1.lock().unwrap().s.len() >= mutex2.lock().unwrap().s.len() {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = mutex1.lock().unwrap().s.len() >= mutex2.lock().unwrap().s.len();
+LL ~ match value {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:369:11
++ --> $DIR/significant_drop_in_scrutinee.rs:354:11
+ |
+LL | match get_mutex_guard().s.len() > 1 {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = get_mutex_guard().s.len() > 1;
+LL ~ match value {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:395:11
++ --> $DIR/significant_drop_in_scrutinee.rs:371:11
+ |
+LL | match match i {
+ | ___________^
+LL | | 100 => mutex1.lock().unwrap(),
+LL | | _ => mutex2.lock().unwrap(),
+LL | | }
+LL | | .s
+LL | | .len()
+LL | | > 1
+ | |___________^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = match i {
+LL + 100 => mutex1.lock().unwrap(),
+LL + _ => mutex2.lock().unwrap(),
+LL + }
+LL + .s
+LL + .len()
+ ...
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:449:11
++ --> $DIR/significant_drop_in_scrutinee.rs:397:11
+ |
+LL | match if i > 1 {
+ | ___________^
+LL | | mutex1.lock().unwrap()
+LL | | } else {
+LL | | mutex2.lock().unwrap()
+... |
+LL | | .len()
+LL | | > 1
+ | |___________^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ let value = if i > 1 {
+LL + mutex1.lock().unwrap()
+LL + } else {
+LL + mutex2.lock().unwrap()
+LL + }
+LL + .s
+ ...
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:477:11
++ --> $DIR/significant_drop_in_scrutinee.rs:451:11
+ |
+LL | match s.lock().deref().deref() {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match and create a copy
+ |
+LL ~ let value = *s.lock().deref().deref();
+LL ~ match value {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:496:11
++ --> $DIR/significant_drop_in_scrutinee.rs:479:11
+ |
+LL | match s.lock().deref().deref() {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:502:11
++ --> $DIR/significant_drop_in_scrutinee.rs:498:11
+ |
+LL | match mutex.lock().unwrap().i = i {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ mutex.lock().unwrap().i = i;
+LL ~ match () {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:508:11
++ --> $DIR/significant_drop_in_scrutinee.rs:504:11
+ |
+LL | match i = mutex.lock().unwrap().i {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ i = mutex.lock().unwrap().i;
+LL ~ match () {
+ |
+
+error: temporary with significant drop in match scrutinee
- --> $DIR/significant_drop_in_scrutinee.rs:514:11
++ --> $DIR/significant_drop_in_scrutinee.rs:510:11
+ |
+LL | match mutex.lock().unwrap().i += 1 {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ mutex.lock().unwrap().i += 1;
+LL ~ match () {
+ |
+
+error: temporary with significant drop in match scrutinee
- error: aborting due to 23 previous errors
++ --> $DIR/significant_drop_in_scrutinee.rs:516:11
+ |
+LL | match i += mutex.lock().unwrap().i {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: try moving the temporary above the match
+ |
+LL ~ i += mutex.lock().unwrap().i;
+LL ~ match () {
+ |
+
++error: temporary with significant drop in match scrutinee
++ --> $DIR/significant_drop_in_scrutinee.rs:579:11
++ |
++LL | match rwlock.read().unwrap().to_number() {
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: temporary with significant drop in for loop
++ --> $DIR/significant_drop_in_scrutinee.rs:589:14
++ |
++LL | for s in rwlock.read().unwrap().iter() {
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: aborting due to 25 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::suspicious_operation_groupings)]
++#![allow(dead_code, unused_parens, clippy::eq_op)]
++
++struct Vec3 {
++ x: f64,
++ y: f64,
++ z: f64,
++}
++
++impl Eq for Vec3 {}
++
++impl PartialEq for Vec3 {
++ fn eq(&self, other: &Self) -> bool {
++ // This should trigger the lint because `self.x` is compared to `other.y`
++ self.x == other.x && self.y == other.y && self.z == other.z
++ }
++}
++
++struct S {
++ a: i32,
++ b: i32,
++ c: i32,
++ d: i32,
++}
++
++fn buggy_ab_cmp(s1: &S, s2: &S) -> bool {
++ // There's no `s1.b`
++ s1.a < s2.a && s1.b < s2.b
++}
++
++struct SaOnly {
++ a: i32,
++}
++
++impl S {
++ fn a(&self) -> i32 {
++ 0
++ }
++}
++
++fn do_not_give_bad_suggestions_for_this_unusual_expr(s1: &S, s2: &SaOnly) -> bool {
++ // This is superficially similar to `buggy_ab_cmp`, but we should not suggest
++ // `s2.b` since that is invalid.
++ s1.a < s2.a && s1.a() < s1.b
++}
++
++fn do_not_give_bad_suggestions_for_this_macro_expr(s1: &S, s2: &SaOnly) -> bool {
++ macro_rules! s1 {
++ () => {
++ S {
++ a: 1,
++ b: 1,
++ c: 1,
++ d: 1,
++ }
++ };
++ }
++
++ // This is superficially similar to `buggy_ab_cmp`, but we should not suggest
++ // `s2.b` since that is invalid.
++ s1.a < s2.a && s1!().a < s1.b
++}
++
++fn do_not_give_bad_suggestions_for_this_incorrect_expr(s1: &S, s2: &SaOnly) -> bool {
++ // There's two `s1.b`, but we should not suggest `s2.b` since that is invalid
++ s1.a < s2.a && s1.b < s1.b
++}
++
++fn permissable(s1: &S, s2: &S) -> bool {
++ // Something like this seems like it might actually be what is desired.
++ s1.a == s2.b
++}
++
++fn non_boolean_operators(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.c`
++ s1.a * s2.a + s1.b * s2.b + s1.c * s2.c + s1.d * s2.d
++}
++
++fn odd_number_of_pairs(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.b`
++ s1.a * s2.a + s1.b * s2.b + s1.c * s2.c
++}
++
++fn not_caught_by_eq_op_middle_change_left(s1: &S, s2: &S) -> i32 {
++ // There's no `s1.b`
++ s1.a * s2.a + s1.b * s2.b + s1.c * s2.c
++}
++
++fn not_caught_by_eq_op_middle_change_right(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.b`
++ s1.a * s2.a + s1.b * s2.b + s1.c * s2.c
++}
++
++fn not_caught_by_eq_op_start(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.a`
++ s1.a * s2.a + s1.b * s2.b + s1.c * s2.c
++}
++
++fn not_caught_by_eq_op_end(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.c`
++ s1.a * s2.a + s1.b * s2.b + s1.c * s2.c
++}
++
++fn the_cross_product_should_not_lint(s1: &S, s2: &S) -> (i32, i32, i32) {
++ (
++ s1.b * s2.c - s1.c * s2.b,
++ s1.c * s2.a - s1.a * s2.c,
++ s1.a * s2.b - s1.b * s2.a,
++ )
++}
++
++fn outer_parens_simple(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.b`
++ (s1.a * s2.a + s1.b * s2.b)
++}
++
++fn outer_parens(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.c`
++ (s1.a * s2.a + s1.b * s2.b + s1.c * s2.c + s1.d * s2.d)
++}
++
++fn inner_parens(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.c`
++ (s1.a * s2.a) + (s1.b * s2.b) + (s1.c * s2.c) + (s1.d * s2.d)
++}
++
++fn outer_and_some_inner_parens(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.c`
++ ((s1.a * s2.a) + (s1.b * s2.b) + (s1.c * s2.c) + (s1.d * s2.d))
++}
++
++fn all_parens_balanced_tree(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.c`
++ (((s1.a * s2.a) + (s1.b * s2.b)) + ((s1.c * s2.c) + (s1.d * s2.d)))
++}
++
++fn all_parens_left_tree(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.c`
++ (((s1.a * s2.a) + (s1.b * s2.b) + (s1.c * s2.c)) + (s1.d * s2.d))
++}
++
++fn all_parens_right_tree(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.c`
++ ((s1.a * s2.a) + ((s1.b * s2.b) + (s1.c * s2.c) + (s1.d * s2.d)))
++}
++
++fn inside_other_binop_expression(s1: &S, s2: &S) -> i32 {
++ // There's no `s1.b`
++ (s1.a * s2.a + s1.b * s2.b) / 2
++}
++
++fn inside_function_call(s1: &S, s2: &S) -> i32 {
++ // There's no `s1.b`
++ i32::swap_bytes(s1.a * s2.a + s1.b * s2.b)
++}
++
++fn inside_larger_boolean_expression(s1: &S, s2: &S) -> bool {
++ // There's no `s1.c`
++ s1.a > 0 && s1.b > 0 && s1.c == s2.c && s1.d == s2.d
++}
++
++fn inside_larger_boolean_expression_with_unsorted_ops(s1: &S, s2: &S) -> bool {
++ // There's no `s1.c`
++ s1.a > 0 && s1.c == s2.c && s1.b > 0 && s1.d == s2.d
++}
++
++struct Nested {
++ inner: ((i32,), (i32,), (i32,)),
++}
++
++fn changed_middle_ident(n1: &Nested, n2: &Nested) -> bool {
++ // There's no `n2.inner.2.0`
++ (n1.inner.0).0 == (n2.inner.0).0 && (n1.inner.1).0 == (n2.inner.1).0 && (n1.inner.2).0 == (n2.inner.2).0
++}
++
++// `eq_op` should catch this one.
++fn changed_initial_ident(n1: &Nested, n2: &Nested) -> bool {
++ // There's no `n2.inner.0.0`
++ (n1.inner.0).0 == (n1.inner.0).0 && (n1.inner.1).0 == (n2.inner.1).0 && (n1.inner.2).0 == (n2.inner.2).0
++}
++
++fn inside_fn_with_similar_expression(s1: &S, s2: &S, strict: bool) -> bool {
++ if strict {
++ s1.a < s2.a && s1.b < s2.b
++ } else {
++ // There's no `s1.b` in this subexpression
++ s1.a <= s2.a && s1.b <= s2.b
++ }
++}
++
++fn inside_an_if_statement(s1: &mut S, s2: &S) {
++ // There's no `s1.b`
++ if s1.a < s2.a && s1.b < s2.b {
++ s1.c = s2.c;
++ }
++}
++
++fn maximum_unary_minus_right_tree(s1: &S, s2: &S) -> i32 {
++ // There's no `s2.c`
++ -(-(-s1.a * -s2.a) + (-(-s1.b * -s2.b) + -(-s1.c * -s2.c) + -(-s1.d * -s2.d)))
++}
++
++fn unary_minus_and_an_if_expression(s1: &S, s2: &S) -> i32 {
++ // There's no `s1.b`
++ -(if -s1.a < -s2.a && -s1.b < -s2.b { s1.c } else { s2.a })
++}
++
++fn main() {}
--- /dev/null
- #![allow(clippy::eq_op)]
++// run-rustfix
+#![warn(clippy::suspicious_operation_groupings)]
++#![allow(dead_code, unused_parens, clippy::eq_op)]
+
+struct Vec3 {
+ x: f64,
+ y: f64,
+ z: f64,
+}
+
+impl Eq for Vec3 {}
+
+impl PartialEq for Vec3 {
+ fn eq(&self, other: &Self) -> bool {
+ // This should trigger the lint because `self.x` is compared to `other.y`
+ self.x == other.y && self.y == other.y && self.z == other.z
+ }
+}
+
+struct S {
+ a: i32,
+ b: i32,
+ c: i32,
+ d: i32,
+}
+
+fn buggy_ab_cmp(s1: &S, s2: &S) -> bool {
+ // There's no `s1.b`
+ s1.a < s2.a && s1.a < s2.b
+}
+
+struct SaOnly {
+ a: i32,
+}
+
+impl S {
+ fn a(&self) -> i32 {
+ 0
+ }
+}
+
+fn do_not_give_bad_suggestions_for_this_unusual_expr(s1: &S, s2: &SaOnly) -> bool {
+ // This is superficially similar to `buggy_ab_cmp`, but we should not suggest
+ // `s2.b` since that is invalid.
+ s1.a < s2.a && s1.a() < s1.b
+}
+
+fn do_not_give_bad_suggestions_for_this_macro_expr(s1: &S, s2: &SaOnly) -> bool {
+ macro_rules! s1 {
+ () => {
+ S {
+ a: 1,
+ b: 1,
+ c: 1,
+ d: 1,
+ }
+ };
+ }
+
+ // This is superficially similar to `buggy_ab_cmp`, but we should not suggest
+ // `s2.b` since that is invalid.
+ s1.a < s2.a && s1!().a < s1.b
+}
+
+fn do_not_give_bad_suggestions_for_this_incorrect_expr(s1: &S, s2: &SaOnly) -> bool {
+ // There's two `s1.b`, but we should not suggest `s2.b` since that is invalid
+ s1.a < s2.a && s1.b < s1.b
+}
+
+fn permissable(s1: &S, s2: &S) -> bool {
+ // Something like this seems like it might actually be what is desired.
+ s1.a == s2.b
+}
+
+fn non_boolean_operators(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.c`
+ s1.a * s2.a + s1.b * s2.b + s1.c * s2.b + s1.d * s2.d
+}
+
+fn odd_number_of_pairs(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.b`
+ s1.a * s2.a + s1.b * s2.c + s1.c * s2.c
+}
+
+fn not_caught_by_eq_op_middle_change_left(s1: &S, s2: &S) -> i32 {
+ // There's no `s1.b`
+ s1.a * s2.a + s2.b * s2.b + s1.c * s2.c
+}
+
+fn not_caught_by_eq_op_middle_change_right(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.b`
+ s1.a * s2.a + s1.b * s1.b + s1.c * s2.c
+}
+
+fn not_caught_by_eq_op_start(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.a`
+ s1.a * s1.a + s1.b * s2.b + s1.c * s2.c
+}
+
+fn not_caught_by_eq_op_end(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.c`
+ s1.a * s2.a + s1.b * s2.b + s1.c * s1.c
+}
+
+fn the_cross_product_should_not_lint(s1: &S, s2: &S) -> (i32, i32, i32) {
+ (
+ s1.b * s2.c - s1.c * s2.b,
+ s1.c * s2.a - s1.a * s2.c,
+ s1.a * s2.b - s1.b * s2.a,
+ )
+}
+
+fn outer_parens_simple(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.b`
+ (s1.a * s2.a + s1.b * s1.b)
+}
+
+fn outer_parens(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.c`
+ (s1.a * s2.a + s1.b * s2.b + s1.c * s2.b + s1.d * s2.d)
+}
+
+fn inner_parens(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.c`
+ (s1.a * s2.a) + (s1.b * s2.b) + (s1.c * s2.b) + (s1.d * s2.d)
+}
+
+fn outer_and_some_inner_parens(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.c`
+ ((s1.a * s2.a) + (s1.b * s2.b) + (s1.c * s2.b) + (s1.d * s2.d))
+}
+
+fn all_parens_balanced_tree(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.c`
+ (((s1.a * s2.a) + (s1.b * s2.b)) + ((s1.c * s2.b) + (s1.d * s2.d)))
+}
+
+fn all_parens_left_tree(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.c`
+ (((s1.a * s2.a) + (s1.b * s2.b) + (s1.c * s2.b)) + (s1.d * s2.d))
+}
+
+fn all_parens_right_tree(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.c`
+ ((s1.a * s2.a) + ((s1.b * s2.b) + (s1.c * s2.b) + (s1.d * s2.d)))
+}
+
+fn inside_other_binop_expression(s1: &S, s2: &S) -> i32 {
+ // There's no `s1.b`
+ (s1.a * s2.a + s2.b * s2.b) / 2
+}
+
+fn inside_function_call(s1: &S, s2: &S) -> i32 {
+ // There's no `s1.b`
+ i32::swap_bytes(s1.a * s2.a + s2.b * s2.b)
+}
+
+fn inside_larger_boolean_expression(s1: &S, s2: &S) -> bool {
+ // There's no `s1.c`
+ s1.a > 0 && s1.b > 0 && s1.d == s2.c && s1.d == s2.d
+}
+
+fn inside_larger_boolean_expression_with_unsorted_ops(s1: &S, s2: &S) -> bool {
+ // There's no `s1.c`
+ s1.a > 0 && s1.d == s2.c && s1.b > 0 && s1.d == s2.d
+}
+
+struct Nested {
+ inner: ((i32,), (i32,), (i32,)),
+}
+
+fn changed_middle_ident(n1: &Nested, n2: &Nested) -> bool {
+ // There's no `n2.inner.2.0`
+ (n1.inner.0).0 == (n2.inner.0).0 && (n1.inner.1).0 == (n2.inner.1).0 && (n1.inner.2).0 == (n2.inner.1).0
+}
+
+// `eq_op` should catch this one.
+fn changed_initial_ident(n1: &Nested, n2: &Nested) -> bool {
+ // There's no `n2.inner.0.0`
+ (n1.inner.0).0 == (n1.inner.0).0 && (n1.inner.1).0 == (n2.inner.1).0 && (n1.inner.2).0 == (n2.inner.2).0
+}
+
+fn inside_fn_with_similar_expression(s1: &S, s2: &S, strict: bool) -> bool {
+ if strict {
+ s1.a < s2.a && s1.b < s2.b
+ } else {
+ // There's no `s1.b` in this subexpression
+ s1.a <= s2.a && s1.a <= s2.b
+ }
+}
+
+fn inside_an_if_statement(s1: &mut S, s2: &S) {
+ // There's no `s1.b`
+ if s1.a < s2.a && s1.a < s2.b {
+ s1.c = s2.c;
+ }
+}
+
+fn maximum_unary_minus_right_tree(s1: &S, s2: &S) -> i32 {
+ // There's no `s2.c`
+ -(-(-s1.a * -s2.a) + (-(-s1.b * -s2.b) + -(-s1.c * -s2.b) + -(-s1.d * -s2.d)))
+}
+
+fn unary_minus_and_an_if_expression(s1: &S, s2: &S) -> i32 {
+ // There's no `s1.b`
+ -(if -s1.a < -s2.a && -s1.a < -s2.b { s1.c } else { s2.a })
+}
+
+fn main() {}
--- /dev/null
- --> $DIR/suspicious_operation_groupings.rs:15:9
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:28:20
++ --> $DIR/suspicious_operation_groupings.rs:16:9
+ |
+LL | self.x == other.y && self.y == other.y && self.z == other.z
+ | ^^^^^^^^^^^^^^^^^ help: did you mean: `self.x == other.x`
+ |
+ = note: `-D clippy::suspicious-operation-groupings` implied by `-D warnings`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:76:33
++ --> $DIR/suspicious_operation_groupings.rs:29:20
+ |
+LL | s1.a < s2.a && s1.a < s2.b
+ | ^^^^^^^^^^^ help: did you mean: `s1.b < s2.b`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:81:19
++ --> $DIR/suspicious_operation_groupings.rs:77:33
+ |
+LL | s1.a * s2.a + s1.b * s2.b + s1.c * s2.b + s1.d * s2.d
+ | ^^^^^^^^^^^ help: did you mean: `s1.c * s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:81:19
++ --> $DIR/suspicious_operation_groupings.rs:82:19
+ |
+LL | s1.a * s2.a + s1.b * s2.c + s1.c * s2.c
+ | ^^^^^^^^^^^ help: did you mean: `s1.b * s2.b`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:86:19
++ --> $DIR/suspicious_operation_groupings.rs:82:19
+ |
+LL | s1.a * s2.a + s1.b * s2.c + s1.c * s2.c
+ | ^^^^^^^^^^^ help: did you mean: `s1.b * s2.b`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:91:19
++ --> $DIR/suspicious_operation_groupings.rs:87:19
+ |
+LL | s1.a * s2.a + s2.b * s2.b + s1.c * s2.c
+ | ^^^^^^^^^^^ help: did you mean: `s1.b * s2.b`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:96:5
++ --> $DIR/suspicious_operation_groupings.rs:92:19
+ |
+LL | s1.a * s2.a + s1.b * s1.b + s1.c * s2.c
+ | ^^^^^^^^^^^ help: did you mean: `s1.b * s2.b`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:101:33
++ --> $DIR/suspicious_operation_groupings.rs:97:5
+ |
+LL | s1.a * s1.a + s1.b * s2.b + s1.c * s2.c
+ | ^^^^^^^^^^^ help: did you mean: `s1.a * s2.a`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:114:20
++ --> $DIR/suspicious_operation_groupings.rs:102:33
+ |
+LL | s1.a * s2.a + s1.b * s2.b + s1.c * s1.c
+ | ^^^^^^^^^^^ help: did you mean: `s1.c * s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:119:34
++ --> $DIR/suspicious_operation_groupings.rs:115:20
+ |
+LL | (s1.a * s2.a + s1.b * s1.b)
+ | ^^^^^^^^^^^ help: did you mean: `s1.b * s2.b`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:124:38
++ --> $DIR/suspicious_operation_groupings.rs:120:34
+ |
+LL | (s1.a * s2.a + s1.b * s2.b + s1.c * s2.b + s1.d * s2.d)
+ | ^^^^^^^^^^^ help: did you mean: `s1.c * s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:129:39
++ --> $DIR/suspicious_operation_groupings.rs:125:38
+ |
+LL | (s1.a * s2.a) + (s1.b * s2.b) + (s1.c * s2.b) + (s1.d * s2.d)
+ | ^^^^^^^^^^^ help: did you mean: `s1.c * s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:134:42
++ --> $DIR/suspicious_operation_groupings.rs:130:39
+ |
+LL | ((s1.a * s2.a) + (s1.b * s2.b) + (s1.c * s2.b) + (s1.d * s2.d))
+ | ^^^^^^^^^^^ help: did you mean: `s1.c * s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:134:42
++ --> $DIR/suspicious_operation_groupings.rs:135:42
+ |
+LL | (((s1.a * s2.a) + (s1.b * s2.b)) + ((s1.c * s2.b) + (s1.d * s2.d)))
+ | ^^^^^^^^^^^ help: did you mean: `s1.c * s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:139:40
++ --> $DIR/suspicious_operation_groupings.rs:135:42
+ |
+LL | (((s1.a * s2.a) + (s1.b * s2.b)) + ((s1.c * s2.b) + (s1.d * s2.d)))
+ | ^^^^^^^^^^^ help: did you mean: `s1.c * s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:144:40
++ --> $DIR/suspicious_operation_groupings.rs:140:40
+ |
+LL | (((s1.a * s2.a) + (s1.b * s2.b) + (s1.c * s2.b)) + (s1.d * s2.d))
+ | ^^^^^^^^^^^ help: did you mean: `s1.c * s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:149:20
++ --> $DIR/suspicious_operation_groupings.rs:145:40
+ |
+LL | ((s1.a * s2.a) + ((s1.b * s2.b) + (s1.c * s2.b) + (s1.d * s2.d)))
+ | ^^^^^^^^^^^ help: did you mean: `s1.c * s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:154:35
++ --> $DIR/suspicious_operation_groupings.rs:150:20
+ |
+LL | (s1.a * s2.a + s2.b * s2.b) / 2
+ | ^^^^^^^^^^^ help: did you mean: `s1.b * s2.b`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:159:29
++ --> $DIR/suspicious_operation_groupings.rs:155:35
+ |
+LL | i32::swap_bytes(s1.a * s2.a + s2.b * s2.b)
+ | ^^^^^^^^^^^ help: did you mean: `s1.b * s2.b`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:164:17
++ --> $DIR/suspicious_operation_groupings.rs:160:29
+ |
+LL | s1.a > 0 && s1.b > 0 && s1.d == s2.c && s1.d == s2.d
+ | ^^^^^^^^^^^^ help: did you mean: `s1.c == s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:173:77
++ --> $DIR/suspicious_operation_groupings.rs:165:17
+ |
+LL | s1.a > 0 && s1.d == s2.c && s1.b > 0 && s1.d == s2.d
+ | ^^^^^^^^^^^^ help: did you mean: `s1.c == s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:187:25
++ --> $DIR/suspicious_operation_groupings.rs:174:77
+ |
+LL | (n1.inner.0).0 == (n2.inner.0).0 && (n1.inner.1).0 == (n2.inner.1).0 && (n1.inner.2).0 == (n2.inner.1).0
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: did you mean: `(n1.inner.2).0 == (n2.inner.2).0`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:193:23
++ --> $DIR/suspicious_operation_groupings.rs:188:25
+ |
+LL | s1.a <= s2.a && s1.a <= s2.b
+ | ^^^^^^^^^^^^ help: did you mean: `s1.b <= s2.b`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:200:48
++ --> $DIR/suspicious_operation_groupings.rs:194:23
+ |
+LL | if s1.a < s2.a && s1.a < s2.b {
+ | ^^^^^^^^^^^ help: did you mean: `s1.b < s2.b`
+
+error: this sequence of operators looks suspiciously like a bug
- --> $DIR/suspicious_operation_groupings.rs:205:27
++ --> $DIR/suspicious_operation_groupings.rs:201:48
+ |
+LL | -(-(-s1.a * -s2.a) + (-(-s1.b * -s2.b) + -(-s1.c * -s2.b) + -(-s1.d * -s2.d)))
+ | ^^^^^^^^^^^^^ help: did you mean: `-s1.c * -s2.c`
+
+error: this sequence of operators looks suspiciously like a bug
++ --> $DIR/suspicious_operation_groupings.rs:206:27
+ |
+LL | -(if -s1.a < -s2.a && -s1.a < -s2.b { s1.c } else { s2.a })
+ | ^^^^^^^^^^^^^ help: did you mean: `-s1.b < -s2.b`
+
+error: aborting due to 26 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++
++#![warn(clippy::swap_ptr_to_ref)]
++
++use core::ptr::addr_of_mut;
++
++fn main() {
++ let mut x = 0u32;
++ let y: *mut _ = &mut x;
++ let z: *mut _ = &mut x;
++
++ unsafe {
++ core::ptr::swap(y, z);
++ core::ptr::swap(y, &mut x);
++ core::ptr::swap(&mut x, y);
++ core::ptr::swap(addr_of_mut!(x), addr_of_mut!(x));
++ }
++
++ let y = &mut x;
++ let mut z = 0u32;
++ let z = &mut z;
++
++ core::mem::swap(y, z);
++}
--- /dev/null
--- /dev/null
++// run-rustfix
++
++#![warn(clippy::swap_ptr_to_ref)]
++
++use core::ptr::addr_of_mut;
++
++fn main() {
++ let mut x = 0u32;
++ let y: *mut _ = &mut x;
++ let z: *mut _ = &mut x;
++
++ unsafe {
++ core::mem::swap(&mut *y, &mut *z);
++ core::mem::swap(&mut *y, &mut x);
++ core::mem::swap(&mut x, &mut *y);
++ core::mem::swap(&mut *addr_of_mut!(x), &mut *addr_of_mut!(x));
++ }
++
++ let y = &mut x;
++ let mut z = 0u32;
++ let z = &mut z;
++
++ core::mem::swap(y, z);
++}
--- /dev/null
--- /dev/null
++error: call to `core::mem::swap` with a parameter derived from a raw pointer
++ --> $DIR/swap_ptr_to_ref.rs:13:9
++ |
++LL | core::mem::swap(&mut *y, &mut *z);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use ptr::swap: `core::ptr::swap(y, z)`
++ |
++ = note: `-D clippy::swap-ptr-to-ref` implied by `-D warnings`
++
++error: call to `core::mem::swap` with a parameter derived from a raw pointer
++ --> $DIR/swap_ptr_to_ref.rs:14:9
++ |
++LL | core::mem::swap(&mut *y, &mut x);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use ptr::swap: `core::ptr::swap(y, &mut x)`
++
++error: call to `core::mem::swap` with a parameter derived from a raw pointer
++ --> $DIR/swap_ptr_to_ref.rs:15:9
++ |
++LL | core::mem::swap(&mut x, &mut *y);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use ptr::swap: `core::ptr::swap(&mut x, y)`
++
++error: call to `core::mem::swap` with a parameter derived from a raw pointer
++ --> $DIR/swap_ptr_to_ref.rs:16:9
++ |
++LL | core::mem::swap(&mut *addr_of_mut!(x), &mut *addr_of_mut!(x));
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use ptr::swap: `core::ptr::swap(addr_of_mut!(x), addr_of_mut!(x))`
++
++error: aborting due to 4 previous errors
++
--- /dev/null
--- /dev/null
++#![warn(clippy::swap_ptr_to_ref)]
++
++macro_rules! addr_of_mut_to_ref {
++ ($e:expr) => {
++ &mut *core::ptr::addr_of_mut!($e)
++ };
++}
++
++fn main() {
++ let mut x = 0u32;
++ let y: *mut _ = &mut x;
++
++ unsafe {
++ core::mem::swap(addr_of_mut_to_ref!(x), &mut *y);
++ core::mem::swap(&mut *y, addr_of_mut_to_ref!(x));
++ core::mem::swap(addr_of_mut_to_ref!(x), addr_of_mut_to_ref!(x));
++ }
++}
--- /dev/null
--- /dev/null
++error: call to `core::mem::swap` with a parameter derived from a raw pointer
++ --> $DIR/swap_ptr_to_ref_unfixable.rs:14:9
++ |
++LL | core::mem::swap(addr_of_mut_to_ref!(x), &mut *y);
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++ |
++ = note: `-D clippy::swap-ptr-to-ref` implied by `-D warnings`
++
++error: call to `core::mem::swap` with a parameter derived from a raw pointer
++ --> $DIR/swap_ptr_to_ref_unfixable.rs:15:9
++ |
++LL | core::mem::swap(&mut *y, addr_of_mut_to_ref!(x));
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: call to `core::mem::swap` with a parameter derived from a raw pointer
++ --> $DIR/swap_ptr_to_ref_unfixable.rs:16:9
++ |
++LL | core::mem::swap(addr_of_mut_to_ref!(x), addr_of_mut_to_ref!(x));
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: aborting due to 3 previous errors
++
--- /dev/null
- let _: &'a T = core::intrinsics::transmute(t);
+#![allow(dead_code, clippy::borrow_as_ptr)]
+
+extern crate core;
+
+use std::mem::transmute as my_transmute;
+use std::vec::Vec as MyVec;
+
+fn my_int() -> Usize {
+ Usize(42)
+}
+
+fn my_vec() -> MyVec<i32> {
+ vec![]
+}
+
+#[allow(clippy::needless_lifetimes, clippy::transmute_ptr_to_ptr)]
+#[warn(clippy::useless_transmute)]
+unsafe fn _generic<'a, T, U: 'a>(t: &'a T) {
++ // FIXME: should lint
++ // let _: &'a T = core::intrinsics::transmute(t);
+
+ let _: &'a U = core::intrinsics::transmute(t);
+
+ let _: *const T = core::intrinsics::transmute(t);
+
+ let _: *mut T = core::intrinsics::transmute(t);
+
+ let _: *const U = core::intrinsics::transmute(t);
+}
+
+#[warn(clippy::useless_transmute)]
+fn useless() {
+ unsafe {
+ let _: Vec<i32> = core::intrinsics::transmute(my_vec());
+
+ let _: Vec<i32> = core::mem::transmute(my_vec());
+
+ let _: Vec<i32> = std::intrinsics::transmute(my_vec());
+
+ let _: Vec<i32> = std::mem::transmute(my_vec());
+
+ let _: Vec<i32> = my_transmute(my_vec());
+
+ let _: *const usize = std::mem::transmute(5_isize);
+
+ let _ = 5_isize as *const usize;
+
+ let _: *const usize = std::mem::transmute(1 + 1usize);
+
+ let _ = (1 + 1_usize) as *const usize;
+ }
++
++ unsafe fn _f<'a, 'b>(x: &'a u32) -> &'b u32 {
++ std::mem::transmute(x)
++ }
++
++ unsafe fn _f2<'a, 'b>(x: *const (dyn Iterator<Item = u32> + 'a)) -> *const (dyn Iterator<Item = u32> + 'b) {
++ std::mem::transmute(x)
++ }
++
++ unsafe fn _f3<'a, 'b>(x: fn(&'a u32)) -> fn(&'b u32) {
++ std::mem::transmute(x)
++ }
++
++ unsafe fn _f4<'a, 'b>(x: std::borrow::Cow<'a, str>) -> std::borrow::Cow<'b, str> {
++ std::mem::transmute(x)
++ }
+}
+
+struct Usize(usize);
+
+#[warn(clippy::crosspointer_transmute)]
+fn crosspointer() {
+ let mut int: Usize = Usize(0);
+ let int_const_ptr: *const Usize = &int as *const Usize;
+ let int_mut_ptr: *mut Usize = &mut int as *mut Usize;
+
+ unsafe {
+ let _: Usize = core::intrinsics::transmute(int_const_ptr);
+
+ let _: Usize = core::intrinsics::transmute(int_mut_ptr);
+
+ let _: *const Usize = core::intrinsics::transmute(my_int());
+
+ let _: *mut Usize = core::intrinsics::transmute(my_int());
+ }
+}
+
+#[warn(clippy::transmute_int_to_char)]
+fn int_to_char() {
+ let _: char = unsafe { std::mem::transmute(0_u32) };
+ let _: char = unsafe { std::mem::transmute(0_i32) };
+
+ // These shouldn't warn
+ const _: char = unsafe { std::mem::transmute(0_u32) };
+ const _: char = unsafe { std::mem::transmute(0_i32) };
+}
+
+#[warn(clippy::transmute_int_to_bool)]
+fn int_to_bool() {
+ let _: bool = unsafe { std::mem::transmute(0_u8) };
+}
+
+#[warn(clippy::transmute_int_to_float)]
+mod int_to_float {
+ fn test() {
+ let _: f32 = unsafe { std::mem::transmute(0_u32) };
+ let _: f32 = unsafe { std::mem::transmute(0_i32) };
+ let _: f64 = unsafe { std::mem::transmute(0_u64) };
+ let _: f64 = unsafe { std::mem::transmute(0_i64) };
+ }
+
+ mod issue_5747 {
+ const VALUE32: f32 = unsafe { std::mem::transmute(0_u32) };
+ const VALUE64: f64 = unsafe { std::mem::transmute(0_i64) };
+
+ const fn from_bits_32(v: i32) -> f32 {
+ unsafe { std::mem::transmute(v) }
+ }
+
+ const fn from_bits_64(v: u64) -> f64 {
+ unsafe { std::mem::transmute(v) }
+ }
+ }
+}
+
+mod num_to_bytes {
+ fn test() {
+ unsafe {
+ let _: [u8; 1] = std::mem::transmute(0u8);
+ let _: [u8; 4] = std::mem::transmute(0u32);
+ let _: [u8; 16] = std::mem::transmute(0u128);
+ let _: [u8; 1] = std::mem::transmute(0i8);
+ let _: [u8; 4] = std::mem::transmute(0i32);
+ let _: [u8; 16] = std::mem::transmute(0i128);
+ let _: [u8; 4] = std::mem::transmute(0.0f32);
+ let _: [u8; 8] = std::mem::transmute(0.0f64);
+ }
+ }
+ const fn test_const() {
+ unsafe {
+ let _: [u8; 1] = std::mem::transmute(0u8);
+ let _: [u8; 4] = std::mem::transmute(0u32);
+ let _: [u8; 16] = std::mem::transmute(0u128);
+ let _: [u8; 1] = std::mem::transmute(0i8);
+ let _: [u8; 4] = std::mem::transmute(0i32);
+ let _: [u8; 16] = std::mem::transmute(0i128);
+ let _: [u8; 4] = std::mem::transmute(0.0f32);
+ let _: [u8; 8] = std::mem::transmute(0.0f64);
+ }
+ }
+}
+
+fn bytes_to_str(mb: &mut [u8]) {
+ const B: &[u8] = b"";
+
+ let _: &str = unsafe { std::mem::transmute(B) };
+ let _: &mut str = unsafe { std::mem::transmute(mb) };
+ const _: &str = unsafe { std::mem::transmute(B) };
+}
+
+fn main() {}
--- /dev/null
- error: transmute from a type (`&T`) to itself
- --> $DIR/transmute.rs:19:20
- |
- LL | let _: &'a T = core::intrinsics::transmute(t);
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- |
- = note: `-D clippy::useless-transmute` implied by `-D warnings`
-
+error: transmute from a reference to a pointer
- --> $DIR/transmute.rs:23:23
++ --> $DIR/transmute.rs:24:23
+ |
+LL | let _: *const T = core::intrinsics::transmute(t);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `t as *const T`
++ |
++ = note: `-D clippy::useless-transmute` implied by `-D warnings`
+
+error: transmute from a reference to a pointer
- --> $DIR/transmute.rs:25:21
++ --> $DIR/transmute.rs:26:21
+ |
+LL | let _: *mut T = core::intrinsics::transmute(t);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `t as *const T as *mut T`
+
+error: transmute from a reference to a pointer
- --> $DIR/transmute.rs:27:23
++ --> $DIR/transmute.rs:28:23
+ |
+LL | let _: *const U = core::intrinsics::transmute(t);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `t as *const T as *const U`
+
+error: transmute from a type (`std::vec::Vec<i32>`) to itself
- --> $DIR/transmute.rs:33:27
++ --> $DIR/transmute.rs:34:27
+ |
+LL | let _: Vec<i32> = core::intrinsics::transmute(my_vec());
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: transmute from a type (`std::vec::Vec<i32>`) to itself
- --> $DIR/transmute.rs:35:27
++ --> $DIR/transmute.rs:36:27
+ |
+LL | let _: Vec<i32> = core::mem::transmute(my_vec());
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: transmute from a type (`std::vec::Vec<i32>`) to itself
- --> $DIR/transmute.rs:37:27
++ --> $DIR/transmute.rs:38:27
+ |
+LL | let _: Vec<i32> = std::intrinsics::transmute(my_vec());
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: transmute from a type (`std::vec::Vec<i32>`) to itself
- --> $DIR/transmute.rs:39:27
++ --> $DIR/transmute.rs:40:27
+ |
+LL | let _: Vec<i32> = std::mem::transmute(my_vec());
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: transmute from a type (`std::vec::Vec<i32>`) to itself
- --> $DIR/transmute.rs:41:27
++ --> $DIR/transmute.rs:42:27
+ |
+LL | let _: Vec<i32> = my_transmute(my_vec());
+ | ^^^^^^^^^^^^^^^^^^^^^^
+
+error: transmute from an integer to a pointer
- --> $DIR/transmute.rs:43:31
++ --> $DIR/transmute.rs:44:31
+ |
+LL | let _: *const usize = std::mem::transmute(5_isize);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `5_isize as *const usize`
+
+error: transmute from an integer to a pointer
- --> $DIR/transmute.rs:47:31
++ --> $DIR/transmute.rs:48:31
+ |
+LL | let _: *const usize = std::mem::transmute(1 + 1usize);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `(1 + 1usize) as *const usize`
+
+error: transmute from a type (`*const Usize`) to the type that it points to (`Usize`)
- --> $DIR/transmute.rs:62:24
++ --> $DIR/transmute.rs:79:24
+ |
+LL | let _: Usize = core::intrinsics::transmute(int_const_ptr);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: `-D clippy::crosspointer-transmute` implied by `-D warnings`
+
+error: transmute from a type (`*mut Usize`) to the type that it points to (`Usize`)
- --> $DIR/transmute.rs:64:24
++ --> $DIR/transmute.rs:81:24
+ |
+LL | let _: Usize = core::intrinsics::transmute(int_mut_ptr);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: transmute from a type (`Usize`) to a pointer to that type (`*const Usize`)
- --> $DIR/transmute.rs:66:31
++ --> $DIR/transmute.rs:83:31
+ |
+LL | let _: *const Usize = core::intrinsics::transmute(my_int());
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: transmute from a type (`Usize`) to a pointer to that type (`*mut Usize`)
- --> $DIR/transmute.rs:68:29
++ --> $DIR/transmute.rs:85:29
+ |
+LL | let _: *mut Usize = core::intrinsics::transmute(my_int());
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: transmute from a `u32` to a `char`
- --> $DIR/transmute.rs:74:28
++ --> $DIR/transmute.rs:91:28
+ |
+LL | let _: char = unsafe { std::mem::transmute(0_u32) };
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `std::char::from_u32(0_u32).unwrap()`
+ |
+ = note: `-D clippy::transmute-int-to-char` implied by `-D warnings`
+
+error: transmute from a `i32` to a `char`
- --> $DIR/transmute.rs:75:28
++ --> $DIR/transmute.rs:92:28
+ |
+LL | let _: char = unsafe { std::mem::transmute(0_i32) };
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `std::char::from_u32(0_i32 as u32).unwrap()`
+
+error: transmute from a `u8` to a `bool`
- --> $DIR/transmute.rs:84:28
++ --> $DIR/transmute.rs:101:28
+ |
+LL | let _: bool = unsafe { std::mem::transmute(0_u8) };
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `0_u8 != 0`
+ |
+ = note: `-D clippy::transmute-int-to-bool` implied by `-D warnings`
+
+error: transmute from a `u32` to a `f32`
- --> $DIR/transmute.rs:90:31
++ --> $DIR/transmute.rs:107:31
+ |
+LL | let _: f32 = unsafe { std::mem::transmute(0_u32) };
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `f32::from_bits(0_u32)`
+ |
+ = note: `-D clippy::transmute-int-to-float` implied by `-D warnings`
+
+error: transmute from a `i32` to a `f32`
- --> $DIR/transmute.rs:91:31
++ --> $DIR/transmute.rs:108:31
+ |
+LL | let _: f32 = unsafe { std::mem::transmute(0_i32) };
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `f32::from_bits(0_i32 as u32)`
+
+error: transmute from a `u64` to a `f64`
- --> $DIR/transmute.rs:92:31
++ --> $DIR/transmute.rs:109:31
+ |
+LL | let _: f64 = unsafe { std::mem::transmute(0_u64) };
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `f64::from_bits(0_u64)`
+
+error: transmute from a `i64` to a `f64`
- --> $DIR/transmute.rs:93:31
++ --> $DIR/transmute.rs:110:31
+ |
+LL | let _: f64 = unsafe { std::mem::transmute(0_i64) };
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `f64::from_bits(0_i64 as u64)`
+
+error: transmute from a `u8` to a `[u8; 1]`
- --> $DIR/transmute.rs:113:30
++ --> $DIR/transmute.rs:130:30
+ |
+LL | let _: [u8; 1] = std::mem::transmute(0u8);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u8.to_ne_bytes()`
+ |
+ = note: `-D clippy::transmute-num-to-bytes` implied by `-D warnings`
+
+error: transmute from a `u32` to a `[u8; 4]`
- --> $DIR/transmute.rs:114:30
++ --> $DIR/transmute.rs:131:30
+ |
+LL | let _: [u8; 4] = std::mem::transmute(0u32);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u32.to_ne_bytes()`
+
+error: transmute from a `u128` to a `[u8; 16]`
- --> $DIR/transmute.rs:115:31
++ --> $DIR/transmute.rs:132:31
+ |
+LL | let _: [u8; 16] = std::mem::transmute(0u128);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u128.to_ne_bytes()`
+
+error: transmute from a `i8` to a `[u8; 1]`
- --> $DIR/transmute.rs:116:30
++ --> $DIR/transmute.rs:133:30
+ |
+LL | let _: [u8; 1] = std::mem::transmute(0i8);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i8.to_ne_bytes()`
+
+error: transmute from a `i32` to a `[u8; 4]`
- --> $DIR/transmute.rs:117:30
++ --> $DIR/transmute.rs:134:30
+ |
+LL | let _: [u8; 4] = std::mem::transmute(0i32);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i32.to_ne_bytes()`
+
+error: transmute from a `i128` to a `[u8; 16]`
- --> $DIR/transmute.rs:118:31
++ --> $DIR/transmute.rs:135:31
+ |
+LL | let _: [u8; 16] = std::mem::transmute(0i128);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i128.to_ne_bytes()`
+
+error: transmute from a `f32` to a `[u8; 4]`
- --> $DIR/transmute.rs:119:30
++ --> $DIR/transmute.rs:136:30
+ |
+LL | let _: [u8; 4] = std::mem::transmute(0.0f32);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0.0f32.to_ne_bytes()`
+
+error: transmute from a `f64` to a `[u8; 8]`
- --> $DIR/transmute.rs:120:30
++ --> $DIR/transmute.rs:137:30
+ |
+LL | let _: [u8; 8] = std::mem::transmute(0.0f64);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0.0f64.to_ne_bytes()`
+
+error: transmute from a `u8` to a `[u8; 1]`
- --> $DIR/transmute.rs:125:30
++ --> $DIR/transmute.rs:142:30
+ |
+LL | let _: [u8; 1] = std::mem::transmute(0u8);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u8.to_ne_bytes()`
+
+error: transmute from a `u32` to a `[u8; 4]`
- --> $DIR/transmute.rs:126:30
++ --> $DIR/transmute.rs:143:30
+ |
+LL | let _: [u8; 4] = std::mem::transmute(0u32);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u32.to_ne_bytes()`
+
+error: transmute from a `u128` to a `[u8; 16]`
- --> $DIR/transmute.rs:127:31
++ --> $DIR/transmute.rs:144:31
+ |
+LL | let _: [u8; 16] = std::mem::transmute(0u128);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u128.to_ne_bytes()`
+
+error: transmute from a `i8` to a `[u8; 1]`
- --> $DIR/transmute.rs:128:30
++ --> $DIR/transmute.rs:145:30
+ |
+LL | let _: [u8; 1] = std::mem::transmute(0i8);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i8.to_ne_bytes()`
+
+error: transmute from a `i32` to a `[u8; 4]`
- --> $DIR/transmute.rs:129:30
++ --> $DIR/transmute.rs:146:30
+ |
+LL | let _: [u8; 4] = std::mem::transmute(0i32);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i32.to_ne_bytes()`
+
+error: transmute from a `i128` to a `[u8; 16]`
- --> $DIR/transmute.rs:130:31
++ --> $DIR/transmute.rs:147:31
+ |
+LL | let _: [u8; 16] = std::mem::transmute(0i128);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i128.to_ne_bytes()`
+
+error: transmute from a `&[u8]` to a `&str`
- --> $DIR/transmute.rs:140:28
++ --> $DIR/transmute.rs:157:28
+ |
+LL | let _: &str = unsafe { std::mem::transmute(B) };
+ | ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `std::str::from_utf8(B).unwrap()`
+ |
+ = note: `-D clippy::transmute-bytes-to-str` implied by `-D warnings`
+
+error: transmute from a `&mut [u8]` to a `&mut str`
- --> $DIR/transmute.rs:141:32
++ --> $DIR/transmute.rs:158:32
+ |
+LL | let _: &mut str = unsafe { std::mem::transmute(mb) };
+ | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `std::str::from_utf8_mut(mb).unwrap()`
+
+error: transmute from a `&[u8]` to a `&str`
- --> $DIR/transmute.rs:142:30
++ --> $DIR/transmute.rs:159:30
+ |
+LL | const _: &str = unsafe { std::mem::transmute(B) };
+ | ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `std::str::from_utf8_unchecked(B)`
+
- error: aborting due to 39 previous errors
++error: aborting due to 38 previous errors
+
--- /dev/null
- #![allow(clippy::unit_arg, clippy::transmute_ptr_to_ref)]
+#![warn(clippy::transmute_undefined_repr)]
++#![allow(clippy::unit_arg, clippy::transmute_ptr_to_ref, clippy::useless_transmute)]
+
+use core::any::TypeId;
+use core::ffi::c_void;
+use core::mem::{size_of, transmute, MaybeUninit};
+
+fn value<T>() -> T {
+ unimplemented!()
+}
+
+struct Empty;
+struct Ty<T>(T);
+struct Ty2<T, U>(T, U);
+
+#[repr(C)]
+struct Ty2C<T, U>(T, U);
+
+fn main() {
+ unsafe {
+ let _: () = transmute(value::<Empty>());
+ let _: Empty = transmute(value::<()>());
+
+ let _: Ty<u32> = transmute(value::<u32>());
+ let _: Ty<u32> = transmute(value::<u32>());
+
+ let _: Ty2C<u32, i32> = transmute(value::<Ty2<u32, i32>>()); // Lint, Ty2 is unordered
+ let _: Ty2<u32, i32> = transmute(value::<Ty2C<u32, i32>>()); // Lint, Ty2 is unordered
+
+ let _: Ty2<u32, i32> = transmute(value::<Ty<Ty2<u32, i32>>>()); // Ok, Ty2 types are the same
+ let _: Ty<Ty2<u32, i32>> = transmute(value::<Ty2<u32, i32>>()); // Ok, Ty2 types are the same
+
+ let _: Ty2<u32, f32> = transmute(value::<Ty<Ty2<u32, i32>>>()); // Lint, different Ty2 instances
+ let _: Ty<Ty2<u32, i32>> = transmute(value::<Ty2<u32, f32>>()); // Lint, different Ty2 instances
+
+ let _: Ty<&()> = transmute(value::<&()>());
+ let _: &() = transmute(value::<Ty<&()>>());
+
+ let _: &Ty2<u32, f32> = transmute(value::<Ty<&Ty2<u32, i32>>>()); // Lint, different Ty2 instances
+ let _: Ty<&Ty2<u32, i32>> = transmute(value::<&Ty2<u32, f32>>()); // Lint, different Ty2 instances
+
+ let _: Ty<usize> = transmute(value::<&Ty2<u32, i32>>()); // Ok, pointer to usize conversion
+ let _: &Ty2<u32, i32> = transmute(value::<Ty<usize>>()); // Ok, pointer to usize conversion
+
+ let _: Ty<[u8; 8]> = transmute(value::<Ty2<u32, i32>>()); // Ok, transmute to byte array
+ let _: Ty2<u32, i32> = transmute(value::<Ty<[u8; 8]>>()); // Ok, transmute from byte array
+
+ // issue #8417
+ let _: Ty2C<Ty2<u32, i32>, ()> = transmute(value::<Ty2<u32, i32>>()); // Ok, Ty2 types are the same
+ let _: Ty2<u32, i32> = transmute(value::<Ty2C<Ty2<u32, i32>, ()>>()); // Ok, Ty2 types are the same
+
+ let _: &'static mut Ty2<u32, u32> = transmute(value::<Box<Ty2<u32, u32>>>()); // Ok, Ty2 types are the same
+ let _: Box<Ty2<u32, u32>> = transmute(value::<&'static mut Ty2<u32, u32>>()); // Ok, Ty2 types are the same
+ let _: *mut Ty2<u32, u32> = transmute(value::<Box<Ty2<u32, u32>>>()); // Ok, Ty2 types are the same
+ let _: Box<Ty2<u32, u32>> = transmute(value::<*mut Ty2<u32, u32>>()); // Ok, Ty2 types are the same
+
+ let _: &'static mut Ty2<u32, f32> = transmute(value::<Box<Ty2<u32, u32>>>()); // Lint, different Ty2 instances
+ let _: Box<Ty2<u32, u32>> = transmute(value::<&'static mut Ty2<u32, f32>>()); // Lint, different Ty2 instances
+
+ let _: *const () = transmute(value::<Ty<&Ty2<u32, f32>>>()); // Ok, type erasure
+ let _: Ty<&Ty2<u32, f32>> = transmute(value::<*const ()>()); // Ok, reverse type erasure
+
+ let _: *const c_void = transmute(value::<Ty<&Ty2<u32, f32>>>()); // Ok, type erasure
+ let _: Ty<&Ty2<u32, f32>> = transmute(value::<*const c_void>()); // Ok, reverse type erasure
+
+ enum Erase {}
+ let _: *const Erase = transmute(value::<Ty<&Ty2<u32, f32>>>()); // Ok, type erasure
+ let _: Ty<&Ty2<u32, f32>> = transmute(value::<*const Erase>()); // Ok, reverse type erasure
+
+ struct Erase2(
+ [u8; 0],
+ core::marker::PhantomData<(*mut u8, core::marker::PhantomPinned)>,
+ );
+ let _: *const Erase2 = transmute(value::<Ty<&Ty2<u32, f32>>>()); // Ok, type erasure
+ let _: Ty<&Ty2<u32, f32>> = transmute(value::<*const Erase2>()); // Ok, reverse type erasure
+
+ let _: *const () = transmute(value::<&&[u8]>()); // Ok, type erasure
+ let _: &&[u8] = transmute(value::<*const ()>()); // Ok, reverse type erasure
+
+ let _: *mut c_void = transmute(value::<&mut &[u8]>()); // Ok, type erasure
+ let _: &mut &[u8] = transmute(value::<*mut c_void>()); // Ok, reverse type erasure
+
+ let _: [u8; size_of::<&[u8]>()] = transmute(value::<&[u8]>()); // Ok, transmute to byte array
+ let _: &[u8] = transmute(value::<[u8; size_of::<&[u8]>()]>()); // Ok, transmute from byte array
+
+ let _: [usize; 2] = transmute(value::<&[u8]>()); // Ok, transmute to int array
+ let _: &[u8] = transmute(value::<[usize; 2]>()); // Ok, transmute from int array
+
+ let _: *const [u8] = transmute(value::<Box<[u8]>>()); // Ok
+ let _: Box<[u8]> = transmute(value::<*mut [u8]>()); // Ok
+
+ let _: Ty2<u32, u32> = transmute(value::<(Ty2<u32, u32>,)>()); // Ok
+ let _: (Ty2<u32, u32>,) = transmute(value::<Ty2<u32, u32>>()); // Ok
+
+ let _: Ty2<u32, u32> = transmute(value::<(Ty2<u32, u32>, ())>()); // Ok
+ let _: (Ty2<u32, u32>, ()) = transmute(value::<Ty2<u32, u32>>()); // Ok
+
+ let _: Ty2<u32, u32> = transmute(value::<((), Ty2<u32, u32>)>()); // Ok
+ let _: ((), Ty2<u32, u32>) = transmute(value::<Ty2<u32, u32>>()); // Ok
+
+ let _: (usize, usize) = transmute(value::<&[u8]>()); // Ok
+ let _: &[u8] = transmute(value::<(usize, usize)>()); // Ok
+
+ trait Trait {}
+ let _: (isize, isize) = transmute(value::<&dyn Trait>()); // Ok
+ let _: &dyn Trait = transmute(value::<(isize, isize)>()); // Ok
+
+ let _: MaybeUninit<Ty2<u32, u32>> = transmute(value::<Ty2<u32, u32>>()); // Ok
+ let _: Ty2<u32, u32> = transmute(value::<MaybeUninit<Ty2<u32, u32>>>()); // Ok
+
+ let _: Ty<&[u32]> = transmute::<&[u32], _>(value::<&Vec<u32>>()); // Ok
+ }
+}
+
+fn _with_generics<T: 'static, U: 'static>() {
+ if TypeId::of::<T>() != TypeId::of::<u32>() || TypeId::of::<T>() != TypeId::of::<U>() {
+ return;
+ }
+ unsafe {
+ let _: &u32 = transmute(value::<&T>()); // Ok
+ let _: &T = transmute(value::<&u32>()); // Ok
+
+ let _: Vec<U> = transmute(value::<Vec<T>>()); // Ok
+ let _: Vec<T> = transmute(value::<Vec<U>>()); // Ok
+
+ let _: Ty<&u32> = transmute(value::<&T>()); // Ok
+ let _: Ty<&T> = transmute(value::<&u32>()); // Ok
+
+ let _: Vec<u32> = transmute(value::<Vec<T>>()); // Ok
+ let _: Vec<T> = transmute(value::<Vec<u32>>()); // Ok
+
+ let _: &Ty2<u32, u32> = transmute(value::<&Ty2<T, U>>()); // Ok
+ let _: &Ty2<T, U> = transmute(value::<&Ty2<u32, u32>>()); // Ok
+
+ let _: Vec<Vec<u32>> = transmute(value::<Vec<Vec<T>>>()); // Ok
+ let _: Vec<Vec<T>> = transmute(value::<Vec<Vec<u32>>>()); // Ok
+
+ let _: Vec<Ty2<T, u32>> = transmute(value::<Vec<Ty2<U, i32>>>()); // Err
+ let _: Vec<Ty2<U, i32>> = transmute(value::<Vec<Ty2<T, u32>>>()); // Err
+
+ let _: *const u32 = transmute(value::<Box<T>>()); // Ok
+ let _: Box<T> = transmute(value::<*const u32>()); // Ok
+ }
+}
--- /dev/null
--- /dev/null
++// run-rustfix
++#[warn(clippy::invisible_characters)]
++fn zero() {
++ print!("Here >\u{200B}< is a ZWS, and \u{200B}another");
++ print!("This\u{200B}is\u{200B}fine");
++ print!("Here >\u{AD}< is a SHY, and \u{AD}another");
++ print!("This\u{ad}is\u{ad}fine");
++ print!("Here >\u{2060}< is a WJ, and \u{2060}another");
++ print!("This\u{2060}is\u{2060}fine");
++}
++
++#[warn(clippy::unicode_not_nfc)]
++fn canon() {
++ print!("̀àh?");
++ print!("a\u{0300}h?"); // also ok
++}
++
++#[warn(clippy::non_ascii_literal)]
++fn uni() {
++ print!("\u{dc}ben!");
++ print!("\u{DC}ben!"); // this is ok
++}
++
++// issue 8013
++#[warn(clippy::non_ascii_literal)]
++fn single_quote() {
++ const _EMPTY_BLOCK: char = '\u{25b1}';
++ const _FULL_BLOCK: char = '\u{25b0}';
++}
++
++fn main() {
++ zero();
++ uni();
++ canon();
++ single_quote();
++}
--- /dev/null
++// run-rustfix
+#[warn(clippy::invisible_characters)]
+fn zero() {
+ print!("Here >< is a ZWS, and another");
+ print!("This\u{200B}is\u{200B}fine");
+ print!("Here >< is a SHY, and another");
+ print!("This\u{ad}is\u{ad}fine");
+ print!("Here >< is a WJ, and another");
+ print!("This\u{2060}is\u{2060}fine");
+}
+
+#[warn(clippy::unicode_not_nfc)]
+fn canon() {
+ print!("̀àh?");
+ print!("a\u{0300}h?"); // also ok
+}
+
+#[warn(clippy::non_ascii_literal)]
+fn uni() {
+ print!("Üben!");
+ print!("\u{DC}ben!"); // this is ok
+}
+
+// issue 8013
+#[warn(clippy::non_ascii_literal)]
+fn single_quote() {
+ const _EMPTY_BLOCK: char = '▱';
+ const _FULL_BLOCK: char = '▰';
+}
+
+fn main() {
+ zero();
+ uni();
+ canon();
+ single_quote();
+}
--- /dev/null
- --> $DIR/unicode.rs:3:12
+error: invisible character detected
- --> $DIR/unicode.rs:5:12
++ --> $DIR/unicode.rs:4:12
+ |
+LL | print!("Here >< is a ZWS, and another");
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider replacing the string with: `"Here >/u{200B}< is a ZWS, and /u{200B}another"`
+ |
+ = note: `-D clippy::invisible-characters` implied by `-D warnings`
+
+error: invisible character detected
- --> $DIR/unicode.rs:7:12
++ --> $DIR/unicode.rs:6:12
+ |
+LL | print!("Here >< is a SHY, and another");
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider replacing the string with: `"Here >/u{AD}< is a SHY, and /u{AD}another"`
+
+error: invisible character detected
- --> $DIR/unicode.rs:13:12
++ --> $DIR/unicode.rs:8:12
+ |
+LL | print!("Here >< is a WJ, and another");
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider replacing the string with: `"Here >/u{2060}< is a WJ, and /u{2060}another"`
+
+error: non-NFC Unicode sequence detected
- --> $DIR/unicode.rs:19:12
++ --> $DIR/unicode.rs:14:12
+ |
+LL | print!("̀àh?");
+ | ^^^^^ help: consider replacing the string with: `"̀àh?"`
+ |
+ = note: `-D clippy::unicode-not-nfc` implied by `-D warnings`
+
+error: literal non-ASCII character detected
- --> $DIR/unicode.rs:26:32
++ --> $DIR/unicode.rs:20:12
+ |
+LL | print!("Üben!");
+ | ^^^^^^^ help: consider replacing the string with: `"/u{dc}ben!"`
+ |
+ = note: `-D clippy::non-ascii-literal` implied by `-D warnings`
+
+error: literal non-ASCII character detected
- --> $DIR/unicode.rs:27:31
++ --> $DIR/unicode.rs:27:32
+ |
+LL | const _EMPTY_BLOCK: char = '▱';
+ | ^^^ help: consider replacing the string with: `'/u{25b1}'`
+
+error: literal non-ASCII character detected
++ --> $DIR/unicode.rs:28:31
+ |
+LL | const _FULL_BLOCK: char = '▰';
+ | ^^^ help: consider replacing the string with: `'/u{25b0}'`
+
+error: aborting due to 7 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::unit_arg)]
++#![allow(clippy::no_effect, unused_must_use, unused_variables)]
++
++use std::fmt::Debug;
++
++fn foo<T: Debug>(t: T) {
++ println!("{:?}", t);
++}
++
++fn foo3<T1: Debug, T2: Debug, T3: Debug>(t1: T1, t2: T2, t3: T3) {
++ println!("{:?}, {:?}, {:?}", t1, t2, t3);
++}
++
++fn bad() {
++ foo(());
++ foo3((), 2, 2);
++ foo(0);
++ taking_two_units((), ());
++ foo(0);
++ foo(1);
++ taking_three_units((), (), ());
++}
++
++fn taking_two_units(a: (), b: ()) {}
++fn taking_three_units(a: (), b: (), c: ()) {}
++
++fn main() {
++ bad();
++}
--- /dev/null
++// run-rustfix
+#![warn(clippy::unit_arg)]
+#![allow(clippy::no_effect, unused_must_use, unused_variables)]
+
+use std::fmt::Debug;
+
+fn foo<T: Debug>(t: T) {
+ println!("{:?}", t);
+}
+
+fn foo3<T1: Debug, T2: Debug, T3: Debug>(t1: T1, t2: T2, t3: T3) {
+ println!("{:?}, {:?}, {:?}", t1, t2, t3);
+}
+
+fn bad() {
+ foo({});
+ foo3({}, 2, 2);
+ taking_two_units({}, foo(0));
+ taking_three_units({}, foo(0), foo(1));
+}
+
+fn taking_two_units(a: (), b: ()) {}
+fn taking_three_units(a: (), b: (), c: ()) {}
+
+fn main() {
+ bad();
+}
--- /dev/null
- --> $DIR/unit_arg_empty_blocks.rs:15:5
+error: passing a unit value to a function
- --> $DIR/unit_arg_empty_blocks.rs:16:5
++ --> $DIR/unit_arg_empty_blocks.rs:16:5
+ |
+LL | foo({});
+ | ^^^^--^
+ | |
+ | help: use a unit literal instead: `()`
+ |
+ = note: `-D clippy::unit-arg` implied by `-D warnings`
+
+error: passing a unit value to a function
- --> $DIR/unit_arg_empty_blocks.rs:17:5
++ --> $DIR/unit_arg_empty_blocks.rs:17:5
+ |
+LL | foo3({}, 2, 2);
+ | ^^^^^--^^^^^^^
+ | |
+ | help: use a unit literal instead: `()`
+
+error: passing unit values to a function
- --> $DIR/unit_arg_empty_blocks.rs:18:5
++ --> $DIR/unit_arg_empty_blocks.rs:18:5
+ |
+LL | taking_two_units({}, foo(0));
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: move the expression in front of the call and replace it with the unit literal `()`
+ |
+LL ~ foo(0);
+LL ~ taking_two_units((), ());
+ |
+
+error: passing unit values to a function
++ --> $DIR/unit_arg_empty_blocks.rs:19:5
+ |
+LL | taking_three_units({}, foo(0), foo(1));
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: move the expressions in front of the call and replace them with the unit literal `()`
+ |
+LL ~ foo(0);
+LL + foo(1);
+LL ~ taking_three_units((), (), ());
+ |
+
+error: aborting due to 4 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::unnecessary_cast)]
++#![allow(
++ unused_must_use,
++ clippy::borrow_as_ptr,
++ clippy::no_effect,
++ clippy::nonstandard_macro_braces,
++ clippy::unnecessary_operation
++)]
++
++#[rustfmt::skip]
++fn main() {
++ // Test cast_unnecessary
++ 1_i32;
++ 1_f32;
++ false;
++ &1i32 as &i32;
++
++ -1_i32;
++ - 1_i32;
++ -1_f32;
++ 1_i32;
++ 1_f32;
++
++ // macro version
++ macro_rules! foo {
++ ($a:ident, $b:ident) => {
++ #[allow(unused)]
++ pub fn $a() -> $b {
++ 1 as $b
++ }
++ };
++ }
++ foo!(a, i32);
++ foo!(b, f32);
++ foo!(c, f64);
++
++ // do not lint cast to cfg-dependant type
++ 1 as std::os::raw::c_char;
++
++ // do not lint cast to alias type
++ 1 as I32Alias;
++ &1 as &I32Alias;
++}
++
++type I32Alias = i32;
++
++mod fixable {
++ #![allow(dead_code)]
++
++ fn main() {
++ // casting integer literal to float is unnecessary
++ 100_f32;
++ 100_f64;
++ 100_f64;
++ let _ = -100_f32;
++ let _ = -100_f64;
++ let _ = -100_f64;
++ 100_f32;
++ 100_f64;
++ // Should not trigger
++ #[rustfmt::skip]
++ let v = vec!(1);
++ &v as &[i32];
++ 0x10 as f32;
++ 0o10 as f32;
++ 0b10 as f32;
++ 0x11 as f64;
++ 0o11 as f64;
++ 0b11 as f64;
++
++ 1_u32;
++ 0x10_i32;
++ 0b10_usize;
++ 0o73_u16;
++ 1_000_000_000_u32;
++
++ 1.0_f64;
++ 0.5_f32;
++
++ 1.0 as u16;
++
++ let _ = -1_i32;
++ let _ = -1.0_f32;
++
++ let _ = 1 as I32Alias;
++ let _ = &1 as &I32Alias;
++ }
++
++ type I32Alias = i32;
++}
--- /dev/null
- #![allow(clippy::no_effect)]
++// run-rustfix
+#![warn(clippy::unnecessary_cast)]
++#![allow(
++ unused_must_use,
++ clippy::borrow_as_ptr,
++ clippy::no_effect,
++ clippy::nonstandard_macro_braces,
++ clippy::unnecessary_operation
++)]
+
+#[rustfmt::skip]
+fn main() {
+ // Test cast_unnecessary
+ 1i32 as i32;
+ 1f32 as f32;
+ false as bool;
+ &1i32 as &i32;
+
+ -1_i32 as i32;
+ - 1_i32 as i32;
+ -1f32 as f32;
+ 1_i32 as i32;
+ 1_f32 as f32;
+
+ // macro version
+ macro_rules! foo {
+ ($a:ident, $b:ident) => {
+ #[allow(unused)]
+ pub fn $a() -> $b {
+ 1 as $b
+ }
+ };
+ }
+ foo!(a, i32);
+ foo!(b, f32);
+ foo!(c, f64);
+
+ // do not lint cast to cfg-dependant type
+ 1 as std::os::raw::c_char;
+
+ // do not lint cast to alias type
+ 1 as I32Alias;
+ &1 as &I32Alias;
+}
+
+type I32Alias = i32;
++
++mod fixable {
++ #![allow(dead_code)]
++
++ fn main() {
++ // casting integer literal to float is unnecessary
++ 100 as f32;
++ 100 as f64;
++ 100_i32 as f64;
++ let _ = -100 as f32;
++ let _ = -100 as f64;
++ let _ = -100_i32 as f64;
++ 100. as f32;
++ 100. as f64;
++ // Should not trigger
++ #[rustfmt::skip]
++ let v = vec!(1);
++ &v as &[i32];
++ 0x10 as f32;
++ 0o10 as f32;
++ 0b10 as f32;
++ 0x11 as f64;
++ 0o11 as f64;
++ 0b11 as f64;
++
++ 1 as u32;
++ 0x10 as i32;
++ 0b10 as usize;
++ 0o73 as u16;
++ 1_000_000_000 as u32;
++
++ 1.0 as f64;
++ 0.5 as f32;
++
++ 1.0 as u16;
++
++ let _ = -1 as i32;
++ let _ = -1.0 as f32;
++
++ let _ = 1 as I32Alias;
++ let _ = &1 as &I32Alias;
++ }
++
++ type I32Alias = i32;
++}
--- /dev/null
- --> $DIR/unnecessary_cast.rs:7:5
+error: casting integer literal to `i32` is unnecessary
- --> $DIR/unnecessary_cast.rs:8:5
++ --> $DIR/unnecessary_cast.rs:14:5
+ |
+LL | 1i32 as i32;
+ | ^^^^^^^^^^^ help: try: `1_i32`
+ |
+ = note: `-D clippy::unnecessary-cast` implied by `-D warnings`
+
+error: casting float literal to `f32` is unnecessary
- --> $DIR/unnecessary_cast.rs:9:5
++ --> $DIR/unnecessary_cast.rs:15:5
+ |
+LL | 1f32 as f32;
+ | ^^^^^^^^^^^ help: try: `1_f32`
+
+error: casting to the same type is unnecessary (`bool` -> `bool`)
- --> $DIR/unnecessary_cast.rs:12:5
++ --> $DIR/unnecessary_cast.rs:16:5
+ |
+LL | false as bool;
+ | ^^^^^^^^^^^^^ help: try: `false`
+
+error: casting integer literal to `i32` is unnecessary
- --> $DIR/unnecessary_cast.rs:13:5
++ --> $DIR/unnecessary_cast.rs:19:5
+ |
+LL | -1_i32 as i32;
+ | ^^^^^^^^^^^^^ help: try: `-1_i32`
+
+error: casting integer literal to `i32` is unnecessary
- --> $DIR/unnecessary_cast.rs:14:5
++ --> $DIR/unnecessary_cast.rs:20:5
+ |
+LL | - 1_i32 as i32;
+ | ^^^^^^^^^^^^^^ help: try: `- 1_i32`
+
+error: casting float literal to `f32` is unnecessary
- --> $DIR/unnecessary_cast.rs:15:5
++ --> $DIR/unnecessary_cast.rs:21:5
+ |
+LL | -1f32 as f32;
+ | ^^^^^^^^^^^^ help: try: `-1_f32`
+
+error: casting integer literal to `i32` is unnecessary
- --> $DIR/unnecessary_cast.rs:16:5
++ --> $DIR/unnecessary_cast.rs:22:5
+ |
+LL | 1_i32 as i32;
+ | ^^^^^^^^^^^^ help: try: `1_i32`
+
+error: casting float literal to `f32` is unnecessary
- error: aborting due to 8 previous errors
++ --> $DIR/unnecessary_cast.rs:23:5
+ |
+LL | 1_f32 as f32;
+ | ^^^^^^^^^^^^ help: try: `1_f32`
+
++error: casting integer literal to `f32` is unnecessary
++ --> $DIR/unnecessary_cast.rs:53:9
++ |
++LL | 100 as f32;
++ | ^^^^^^^^^^ help: try: `100_f32`
++
++error: casting integer literal to `f64` is unnecessary
++ --> $DIR/unnecessary_cast.rs:54:9
++ |
++LL | 100 as f64;
++ | ^^^^^^^^^^ help: try: `100_f64`
++
++error: casting integer literal to `f64` is unnecessary
++ --> $DIR/unnecessary_cast.rs:55:9
++ |
++LL | 100_i32 as f64;
++ | ^^^^^^^^^^^^^^ help: try: `100_f64`
++
++error: casting integer literal to `f32` is unnecessary
++ --> $DIR/unnecessary_cast.rs:56:17
++ |
++LL | let _ = -100 as f32;
++ | ^^^^^^^^^^^ help: try: `-100_f32`
++
++error: casting integer literal to `f64` is unnecessary
++ --> $DIR/unnecessary_cast.rs:57:17
++ |
++LL | let _ = -100 as f64;
++ | ^^^^^^^^^^^ help: try: `-100_f64`
++
++error: casting integer literal to `f64` is unnecessary
++ --> $DIR/unnecessary_cast.rs:58:17
++ |
++LL | let _ = -100_i32 as f64;
++ | ^^^^^^^^^^^^^^^ help: try: `-100_f64`
++
++error: casting float literal to `f32` is unnecessary
++ --> $DIR/unnecessary_cast.rs:59:9
++ |
++LL | 100. as f32;
++ | ^^^^^^^^^^^ help: try: `100_f32`
++
++error: casting float literal to `f64` is unnecessary
++ --> $DIR/unnecessary_cast.rs:60:9
++ |
++LL | 100. as f64;
++ | ^^^^^^^^^^^ help: try: `100_f64`
++
++error: casting integer literal to `u32` is unnecessary
++ --> $DIR/unnecessary_cast.rs:72:9
++ |
++LL | 1 as u32;
++ | ^^^^^^^^ help: try: `1_u32`
++
++error: casting integer literal to `i32` is unnecessary
++ --> $DIR/unnecessary_cast.rs:73:9
++ |
++LL | 0x10 as i32;
++ | ^^^^^^^^^^^ help: try: `0x10_i32`
++
++error: casting integer literal to `usize` is unnecessary
++ --> $DIR/unnecessary_cast.rs:74:9
++ |
++LL | 0b10 as usize;
++ | ^^^^^^^^^^^^^ help: try: `0b10_usize`
++
++error: casting integer literal to `u16` is unnecessary
++ --> $DIR/unnecessary_cast.rs:75:9
++ |
++LL | 0o73 as u16;
++ | ^^^^^^^^^^^ help: try: `0o73_u16`
++
++error: casting integer literal to `u32` is unnecessary
++ --> $DIR/unnecessary_cast.rs:76:9
++ |
++LL | 1_000_000_000 as u32;
++ | ^^^^^^^^^^^^^^^^^^^^ help: try: `1_000_000_000_u32`
++
++error: casting float literal to `f64` is unnecessary
++ --> $DIR/unnecessary_cast.rs:78:9
++ |
++LL | 1.0 as f64;
++ | ^^^^^^^^^^ help: try: `1.0_f64`
++
++error: casting float literal to `f32` is unnecessary
++ --> $DIR/unnecessary_cast.rs:79:9
++ |
++LL | 0.5 as f32;
++ | ^^^^^^^^^^ help: try: `0.5_f32`
++
++error: casting integer literal to `i32` is unnecessary
++ --> $DIR/unnecessary_cast.rs:83:17
++ |
++LL | let _ = -1 as i32;
++ | ^^^^^^^^^ help: try: `-1_i32`
++
++error: casting float literal to `f32` is unnecessary
++ --> $DIR/unnecessary_cast.rs:84:17
++ |
++LL | let _ = -1.0 as f32;
++ | ^^^^^^^^^^^ help: try: `-1.0_f32`
++
++error: aborting due to 25 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::unused_rounding)]
++
++fn main() {
++ let _ = 1f32;
++ let _ = 1.0f64;
++ let _ = 1.00f32;
++ let _ = 2e-54f64.floor();
++}
--- /dev/null
--- /dev/null
++// run-rustfix
++#![warn(clippy::unused_rounding)]
++
++fn main() {
++ let _ = 1f32.ceil();
++ let _ = 1.0f64.floor();
++ let _ = 1.00f32.round();
++ let _ = 2e-54f64.floor();
++}
--- /dev/null
--- /dev/null
++error: used the `ceil` method with a whole number float
++ --> $DIR/unused_rounding.rs:5:13
++ |
++LL | let _ = 1f32.ceil();
++ | ^^^^^^^^^^^ help: remove the `ceil` method call: `1f32`
++ |
++ = note: `-D clippy::unused-rounding` implied by `-D warnings`
++
++error: used the `floor` method with a whole number float
++ --> $DIR/unused_rounding.rs:6:13
++ |
++LL | let _ = 1.0f64.floor();
++ | ^^^^^^^^^^^^^^ help: remove the `floor` method call: `1.0f64`
++
++error: used the `round` method with a whole number float
++ --> $DIR/unused_rounding.rs:7:13
++ |
++LL | let _ = 1.00f32.round();
++ | ^^^^^^^^^^^^^^^ help: remove the `round` method call: `1.00f32`
++
++error: aborting due to 3 previous errors
++
--- /dev/null
+// run-rustfix
+// aux-build:proc_macro_derive.rs
+
+#![warn(clippy::use_self)]
+#![allow(dead_code, unreachable_code)]
+#![allow(
+ clippy::should_implement_trait,
+ clippy::upper_case_acronyms,
+ clippy::from_over_into,
+ clippy::self_named_constructors
+)]
+
+#[macro_use]
+extern crate proc_macro_derive;
+
+fn main() {}
+
+mod use_self {
+ struct Foo;
+
+ impl Foo {
+ fn new() -> Self {
+ Self {}
+ }
+ fn test() -> Self {
+ Self::new()
+ }
+ }
+
+ impl Default for Foo {
+ fn default() -> Self {
+ Self::new()
+ }
+ }
+}
+
+mod better {
+ struct Foo;
+
+ impl Foo {
+ fn new() -> Self {
+ Self {}
+ }
+ fn test() -> Self {
+ Self::new()
+ }
+ }
+
+ impl Default for Foo {
+ fn default() -> Self {
+ Self::new()
+ }
+ }
+}
+
+mod lifetimes {
+ struct Foo<'a> {
+ foo_str: &'a str,
+ }
+
+ impl<'a> Foo<'a> {
+ // Cannot use `Self` as return type, because the function is actually `fn foo<'b>(s: &'b str) ->
+ // Foo<'b>`
+ fn foo(s: &str) -> Foo {
+ Foo { foo_str: s }
+ }
+ // cannot replace with `Self`, because that's `Foo<'a>`
+ fn bar() -> Foo<'static> {
+ Foo { foo_str: "foo" }
+ }
+
+ // FIXME: the lint does not handle lifetimed struct
+ // `Self` should be applicable here
+ fn clone(&self) -> Foo<'a> {
+ Foo { foo_str: self.foo_str }
+ }
+ }
+}
+
+mod issue2894 {
+ trait IntoBytes {
+ fn to_bytes(self) -> Vec<u8>;
+ }
+
+ // This should not be linted
+ impl IntoBytes for u8 {
+ fn to_bytes(self) -> Vec<u8> {
+ vec![self]
+ }
+ }
+}
+
+mod existential {
+ struct Foo;
+
+ impl Foo {
+ fn bad(foos: &[Self]) -> impl Iterator<Item = &Self> {
+ foos.iter()
+ }
+
+ fn good(foos: &[Self]) -> impl Iterator<Item = &Self> {
+ foos.iter()
+ }
+ }
+}
+
+mod tuple_structs {
+ pub struct TS(i32);
+
+ impl TS {
+ pub fn ts() -> Self {
+ Self(0)
+ }
+ }
+}
+
+mod macros {
+ macro_rules! use_self_expand {
+ () => {
+ fn new() -> Foo {
+ Foo {}
+ }
+ };
+ }
+
+ struct Foo;
+
+ impl Foo {
+ use_self_expand!(); // Should not lint in local macros
+ }
+
+ #[derive(StructAUseSelf)] // Should not lint in derives
+ struct A;
+}
+
+mod nesting {
+ struct Foo;
+ impl Foo {
+ fn foo() {
+ #[allow(unused_imports)]
+ use self::Foo; // Can't use Self here
+ struct Bar {
+ foo: Foo, // Foo != Self
+ }
+
+ impl Bar {
+ fn bar() -> Self {
+ Self { foo: Foo {} }
+ }
+ }
+
+ // Can't use Self here
+ fn baz() -> Foo {
+ Foo {}
+ }
+ }
+
+ // Should lint here
+ fn baz() -> Self {
+ Self {}
+ }
+ }
+
+ enum Enum {
+ A,
+ B(u64),
+ C { field: bool },
+ }
+ impl Enum {
+ fn method() {
+ #[allow(unused_imports)]
+ use self::Enum::*; // Issue 3425
+ static STATIC: Enum = Enum::A; // Can't use Self as type
+ }
+
+ fn method2() {
+ let _ = Self::B(42);
+ let _ = Self::C { field: true };
+ let _ = Self::A;
+ }
+ }
+}
+
+mod issue3410 {
+
+ struct A;
+ struct B;
+
+ trait Trait<T> {
+ fn a(v: T) -> Self;
+ }
+
+ impl Trait<Vec<A>> for Vec<B> {
+ fn a(_: Vec<A>) -> Self {
+ unimplemented!()
+ }
+ }
+
+ impl<T> Trait<Vec<A>> for Vec<T>
+ where
+ T: Trait<B>,
+ {
+ fn a(v: Vec<A>) -> Self {
+ <Vec<B>>::a(v).into_iter().map(Trait::a).collect()
+ }
+ }
+}
+
+#[allow(clippy::no_effect, path_statements)]
+mod rustfix {
+ mod nested {
+ pub struct A;
+ }
+
+ impl nested::A {
+ const A: bool = true;
+
+ fn fun_1() {}
+
+ fn fun_2() {
+ Self::fun_1();
+ Self::A;
+
+ Self {};
+ }
+ }
+}
+
+mod issue3567 {
+ struct TestStruct;
+ impl TestStruct {
+ fn from_something() -> Self {
+ Self {}
+ }
+ }
+
+ trait Test {
+ fn test() -> TestStruct;
+ }
+
+ impl Test for TestStruct {
+ fn test() -> TestStruct {
+ Self::from_something()
+ }
+ }
+}
+
+mod paths_created_by_lowering {
+ use std::ops::Range;
+
+ struct S;
+
+ impl S {
+ const A: usize = 0;
+ const B: usize = 1;
+
+ async fn g() -> Self {
+ Self {}
+ }
+
+ fn f<'a>(&self, p: &'a [u8]) -> &'a [u8] {
+ &p[Self::A..Self::B]
+ }
+ }
+
+ trait T {
+ fn f<'a>(&self, p: &'a [u8]) -> &'a [u8];
+ }
+
+ impl T for Range<u8> {
+ fn f<'a>(&self, p: &'a [u8]) -> &'a [u8] {
+ &p[0..1]
+ }
+ }
+}
+
+// reused from #1997
+mod generics {
+ struct Foo<T> {
+ value: T,
+ }
+
+ impl<T> Foo<T> {
+ // `Self` is applicable here
+ fn foo(value: T) -> Self {
+ Self { value }
+ }
+
+ // `Cannot` use `Self` as a return type as the generic types are different
+ fn bar(value: i32) -> Foo<i32> {
+ Foo { value }
+ }
+ }
+}
+
+mod issue4140 {
+ pub struct Error<From, To> {
+ _from: From,
+ _too: To,
+ }
+
+ pub trait From<T> {
+ type From;
+ type To;
+
+ fn from(value: T) -> Self;
+ }
+
+ pub trait TryFrom<T>
+ where
+ Self: Sized,
+ {
+ type From;
+ type To;
+
+ fn try_from(value: T) -> Result<Self, Error<Self::From, Self::To>>;
+ }
+
+ // FIXME: Suggested fix results in infinite recursion.
+ // impl<F, T> TryFrom<F> for T
+ // where
+ // T: From<F>,
+ // {
+ // type From = Self::From;
+ // type To = Self::To;
+
+ // fn try_from(value: F) -> Result<Self, Error<Self::From, Self::To>> {
+ // Ok(From::from(value))
+ // }
+ // }
+
+ impl From<bool> for i64 {
+ type From = bool;
+ type To = Self;
+
+ fn from(value: bool) -> Self {
+ if value { 100 } else { 0 }
+ }
+ }
+}
+
+mod issue2843 {
+ trait Foo {
+ type Bar;
+ }
+
+ impl Foo for usize {
+ type Bar = u8;
+ }
+
+ impl<T: Foo> Foo for Option<T> {
+ type Bar = Option<T::Bar>;
+ }
+}
+
+mod issue3859 {
+ pub struct Foo;
+ pub struct Bar([usize; 3]);
+
+ impl Foo {
+ pub const BAR: usize = 3;
+
+ pub fn foo() {
+ const _X: usize = Foo::BAR;
+ // const _Y: usize = Self::BAR;
+ }
+ }
+}
+
+mod issue4305 {
+ trait Foo: 'static {}
+
+ struct Bar;
+
+ impl Foo for Bar {}
+
+ impl<T: Foo> From<T> for Box<dyn Foo> {
+ fn from(t: T) -> Self {
+ Box::new(t)
+ }
+ }
+}
+
+mod lint_at_item_level {
+ struct Foo;
+
+ #[allow(clippy::use_self)]
+ impl Foo {
+ fn new() -> Foo {
+ Foo {}
+ }
+ }
+
+ #[allow(clippy::use_self)]
+ impl Default for Foo {
+ fn default() -> Foo {
+ Foo::new()
+ }
+ }
+}
+
+mod lint_at_impl_item_level {
+ struct Foo;
+
+ impl Foo {
+ #[allow(clippy::use_self)]
+ fn new() -> Foo {
+ Foo {}
+ }
+ }
+
+ impl Default for Foo {
+ #[allow(clippy::use_self)]
+ fn default() -> Foo {
+ Foo::new()
+ }
+ }
+}
+
+mod issue4734 {
+ #[repr(C, packed)]
+ pub struct X {
+ pub x: u32,
+ }
+
+ impl From<X> for u32 {
+ fn from(c: X) -> Self {
+ unsafe { core::mem::transmute(c) }
+ }
+ }
+}
+
+mod nested_paths {
+ use std::convert::Into;
+ mod submod {
+ pub struct B;
+ pub struct C;
+
+ impl Into<C> for B {
+ fn into(self) -> C {
+ C {}
+ }
+ }
+ }
+
+ struct A<T> {
+ t: T,
+ }
+
+ impl<T> A<T> {
+ fn new<V: Into<T>>(v: V) -> Self {
+ Self { t: Into::into(v) }
+ }
+ }
+
+ impl A<submod::C> {
+ fn test() -> Self {
+ Self::new::<submod::B>(submod::B {})
+ }
+ }
+}
+
+mod issue6818 {
+ #[derive(serde::Deserialize)]
+ struct A {
+ a: i32,
+ }
+}
+
+mod issue7206 {
+ struct MyStruct<const C: char>;
+ impl From<MyStruct<'a'>> for MyStruct<'b'> {
+ fn from(_s: MyStruct<'a'>) -> Self {
+ Self
+ }
+ }
+
+ // keep linting non-`Const` generic args
+ struct S<'a> {
+ inner: &'a str,
+ }
+
+ struct S2<T> {
+ inner: T,
+ }
+
+ impl<T> S2<T> {
+ fn new() -> Self {
+ unimplemented!();
+ }
+ }
+
+ impl<'a> S2<S<'a>> {
+ fn new_again() -> Self {
+ Self::new()
+ }
+ }
+}
+
+mod self_is_ty_param {
+ trait Trait {
+ type Type;
+ type Hi;
+
+ fn test();
+ }
+
+ impl<I> Trait for I
+ where
+ I: Iterator,
+ I::Item: Trait, // changing this to Self would require <Self as Iterator>
+ {
+ type Type = I;
+ type Hi = I::Item;
+
+ fn test() {
+ let _: I::Item;
+ let _: I; // this could lint, but is questionable
+ }
+ }
+}
+
+mod use_self_in_pat {
+ enum Foo {
+ Bar,
+ Baz,
+ }
+
+ impl Foo {
+ fn do_stuff(self) {
+ match self {
+ Self::Bar => unimplemented!(),
+ Self::Baz => unimplemented!(),
+ }
+ match Some(1) {
+ Some(_) => unimplemented!(),
+ None => unimplemented!(),
+ }
+ if let Self::Bar = self {
+ unimplemented!()
+ }
+ }
+ }
+}
++
++mod issue8845 {
++ pub enum Something {
++ Num(u8),
++ TupleNums(u8, u8),
++ StructNums { one: u8, two: u8 },
++ }
++
++ struct Foo(u8);
++
++ struct Bar {
++ x: u8,
++ y: usize,
++ }
++
++ impl Something {
++ fn get_value(&self) -> u8 {
++ match self {
++ Self::Num(n) => *n,
++ Self::TupleNums(n, _m) => *n,
++ Self::StructNums { one, two: _ } => *one,
++ }
++ }
++
++ fn use_crate(&self) -> u8 {
++ match self {
++ Self::Num(n) => *n,
++ Self::TupleNums(n, _m) => *n,
++ Self::StructNums { one, two: _ } => *one,
++ }
++ }
++
++ fn imported_values(&self) -> u8 {
++ use Something::*;
++ match self {
++ Num(n) => *n,
++ TupleNums(n, _m) => *n,
++ StructNums { one, two: _ } => *one,
++ }
++ }
++ }
++
++ impl Foo {
++ fn get_value(&self) -> u8 {
++ let Self(x) = self;
++ *x
++ }
++
++ fn use_crate(&self) -> u8 {
++ let Self(x) = self;
++ *x
++ }
++ }
++
++ impl Bar {
++ fn get_value(&self) -> u8 {
++ let Self { x, .. } = self;
++ *x
++ }
++
++ fn use_crate(&self) -> u8 {
++ let Self { x, .. } = self;
++ *x
++ }
++ }
++}
--- /dev/null
+// run-rustfix
+// aux-build:proc_macro_derive.rs
+
+#![warn(clippy::use_self)]
+#![allow(dead_code, unreachable_code)]
+#![allow(
+ clippy::should_implement_trait,
+ clippy::upper_case_acronyms,
+ clippy::from_over_into,
+ clippy::self_named_constructors
+)]
+
+#[macro_use]
+extern crate proc_macro_derive;
+
+fn main() {}
+
+mod use_self {
+ struct Foo;
+
+ impl Foo {
+ fn new() -> Foo {
+ Foo {}
+ }
+ fn test() -> Foo {
+ Foo::new()
+ }
+ }
+
+ impl Default for Foo {
+ fn default() -> Foo {
+ Foo::new()
+ }
+ }
+}
+
+mod better {
+ struct Foo;
+
+ impl Foo {
+ fn new() -> Self {
+ Self {}
+ }
+ fn test() -> Self {
+ Self::new()
+ }
+ }
+
+ impl Default for Foo {
+ fn default() -> Self {
+ Self::new()
+ }
+ }
+}
+
+mod lifetimes {
+ struct Foo<'a> {
+ foo_str: &'a str,
+ }
+
+ impl<'a> Foo<'a> {
+ // Cannot use `Self` as return type, because the function is actually `fn foo<'b>(s: &'b str) ->
+ // Foo<'b>`
+ fn foo(s: &str) -> Foo {
+ Foo { foo_str: s }
+ }
+ // cannot replace with `Self`, because that's `Foo<'a>`
+ fn bar() -> Foo<'static> {
+ Foo { foo_str: "foo" }
+ }
+
+ // FIXME: the lint does not handle lifetimed struct
+ // `Self` should be applicable here
+ fn clone(&self) -> Foo<'a> {
+ Foo { foo_str: self.foo_str }
+ }
+ }
+}
+
+mod issue2894 {
+ trait IntoBytes {
+ fn to_bytes(self) -> Vec<u8>;
+ }
+
+ // This should not be linted
+ impl IntoBytes for u8 {
+ fn to_bytes(self) -> Vec<u8> {
+ vec![self]
+ }
+ }
+}
+
+mod existential {
+ struct Foo;
+
+ impl Foo {
+ fn bad(foos: &[Foo]) -> impl Iterator<Item = &Foo> {
+ foos.iter()
+ }
+
+ fn good(foos: &[Self]) -> impl Iterator<Item = &Self> {
+ foos.iter()
+ }
+ }
+}
+
+mod tuple_structs {
+ pub struct TS(i32);
+
+ impl TS {
+ pub fn ts() -> Self {
+ TS(0)
+ }
+ }
+}
+
+mod macros {
+ macro_rules! use_self_expand {
+ () => {
+ fn new() -> Foo {
+ Foo {}
+ }
+ };
+ }
+
+ struct Foo;
+
+ impl Foo {
+ use_self_expand!(); // Should not lint in local macros
+ }
+
+ #[derive(StructAUseSelf)] // Should not lint in derives
+ struct A;
+}
+
+mod nesting {
+ struct Foo;
+ impl Foo {
+ fn foo() {
+ #[allow(unused_imports)]
+ use self::Foo; // Can't use Self here
+ struct Bar {
+ foo: Foo, // Foo != Self
+ }
+
+ impl Bar {
+ fn bar() -> Bar {
+ Bar { foo: Foo {} }
+ }
+ }
+
+ // Can't use Self here
+ fn baz() -> Foo {
+ Foo {}
+ }
+ }
+
+ // Should lint here
+ fn baz() -> Foo {
+ Foo {}
+ }
+ }
+
+ enum Enum {
+ A,
+ B(u64),
+ C { field: bool },
+ }
+ impl Enum {
+ fn method() {
+ #[allow(unused_imports)]
+ use self::Enum::*; // Issue 3425
+ static STATIC: Enum = Enum::A; // Can't use Self as type
+ }
+
+ fn method2() {
+ let _ = Enum::B(42);
+ let _ = Enum::C { field: true };
+ let _ = Enum::A;
+ }
+ }
+}
+
+mod issue3410 {
+
+ struct A;
+ struct B;
+
+ trait Trait<T> {
+ fn a(v: T) -> Self;
+ }
+
+ impl Trait<Vec<A>> for Vec<B> {
+ fn a(_: Vec<A>) -> Self {
+ unimplemented!()
+ }
+ }
+
+ impl<T> Trait<Vec<A>> for Vec<T>
+ where
+ T: Trait<B>,
+ {
+ fn a(v: Vec<A>) -> Self {
+ <Vec<B>>::a(v).into_iter().map(Trait::a).collect()
+ }
+ }
+}
+
+#[allow(clippy::no_effect, path_statements)]
+mod rustfix {
+ mod nested {
+ pub struct A;
+ }
+
+ impl nested::A {
+ const A: bool = true;
+
+ fn fun_1() {}
+
+ fn fun_2() {
+ nested::A::fun_1();
+ nested::A::A;
+
+ nested::A {};
+ }
+ }
+}
+
+mod issue3567 {
+ struct TestStruct;
+ impl TestStruct {
+ fn from_something() -> Self {
+ Self {}
+ }
+ }
+
+ trait Test {
+ fn test() -> TestStruct;
+ }
+
+ impl Test for TestStruct {
+ fn test() -> TestStruct {
+ TestStruct::from_something()
+ }
+ }
+}
+
+mod paths_created_by_lowering {
+ use std::ops::Range;
+
+ struct S;
+
+ impl S {
+ const A: usize = 0;
+ const B: usize = 1;
+
+ async fn g() -> S {
+ S {}
+ }
+
+ fn f<'a>(&self, p: &'a [u8]) -> &'a [u8] {
+ &p[S::A..S::B]
+ }
+ }
+
+ trait T {
+ fn f<'a>(&self, p: &'a [u8]) -> &'a [u8];
+ }
+
+ impl T for Range<u8> {
+ fn f<'a>(&self, p: &'a [u8]) -> &'a [u8] {
+ &p[0..1]
+ }
+ }
+}
+
+// reused from #1997
+mod generics {
+ struct Foo<T> {
+ value: T,
+ }
+
+ impl<T> Foo<T> {
+ // `Self` is applicable here
+ fn foo(value: T) -> Foo<T> {
+ Foo::<T> { value }
+ }
+
+ // `Cannot` use `Self` as a return type as the generic types are different
+ fn bar(value: i32) -> Foo<i32> {
+ Foo { value }
+ }
+ }
+}
+
+mod issue4140 {
+ pub struct Error<From, To> {
+ _from: From,
+ _too: To,
+ }
+
+ pub trait From<T> {
+ type From;
+ type To;
+
+ fn from(value: T) -> Self;
+ }
+
+ pub trait TryFrom<T>
+ where
+ Self: Sized,
+ {
+ type From;
+ type To;
+
+ fn try_from(value: T) -> Result<Self, Error<Self::From, Self::To>>;
+ }
+
+ // FIXME: Suggested fix results in infinite recursion.
+ // impl<F, T> TryFrom<F> for T
+ // where
+ // T: From<F>,
+ // {
+ // type From = Self::From;
+ // type To = Self::To;
+
+ // fn try_from(value: F) -> Result<Self, Error<Self::From, Self::To>> {
+ // Ok(From::from(value))
+ // }
+ // }
+
+ impl From<bool> for i64 {
+ type From = bool;
+ type To = Self;
+
+ fn from(value: bool) -> Self {
+ if value { 100 } else { 0 }
+ }
+ }
+}
+
+mod issue2843 {
+ trait Foo {
+ type Bar;
+ }
+
+ impl Foo for usize {
+ type Bar = u8;
+ }
+
+ impl<T: Foo> Foo for Option<T> {
+ type Bar = Option<T::Bar>;
+ }
+}
+
+mod issue3859 {
+ pub struct Foo;
+ pub struct Bar([usize; 3]);
+
+ impl Foo {
+ pub const BAR: usize = 3;
+
+ pub fn foo() {
+ const _X: usize = Foo::BAR;
+ // const _Y: usize = Self::BAR;
+ }
+ }
+}
+
+mod issue4305 {
+ trait Foo: 'static {}
+
+ struct Bar;
+
+ impl Foo for Bar {}
+
+ impl<T: Foo> From<T> for Box<dyn Foo> {
+ fn from(t: T) -> Self {
+ Box::new(t)
+ }
+ }
+}
+
+mod lint_at_item_level {
+ struct Foo;
+
+ #[allow(clippy::use_self)]
+ impl Foo {
+ fn new() -> Foo {
+ Foo {}
+ }
+ }
+
+ #[allow(clippy::use_self)]
+ impl Default for Foo {
+ fn default() -> Foo {
+ Foo::new()
+ }
+ }
+}
+
+mod lint_at_impl_item_level {
+ struct Foo;
+
+ impl Foo {
+ #[allow(clippy::use_self)]
+ fn new() -> Foo {
+ Foo {}
+ }
+ }
+
+ impl Default for Foo {
+ #[allow(clippy::use_self)]
+ fn default() -> Foo {
+ Foo::new()
+ }
+ }
+}
+
+mod issue4734 {
+ #[repr(C, packed)]
+ pub struct X {
+ pub x: u32,
+ }
+
+ impl From<X> for u32 {
+ fn from(c: X) -> Self {
+ unsafe { core::mem::transmute(c) }
+ }
+ }
+}
+
+mod nested_paths {
+ use std::convert::Into;
+ mod submod {
+ pub struct B;
+ pub struct C;
+
+ impl Into<C> for B {
+ fn into(self) -> C {
+ C {}
+ }
+ }
+ }
+
+ struct A<T> {
+ t: T,
+ }
+
+ impl<T> A<T> {
+ fn new<V: Into<T>>(v: V) -> Self {
+ Self { t: Into::into(v) }
+ }
+ }
+
+ impl A<submod::C> {
+ fn test() -> Self {
+ A::new::<submod::B>(submod::B {})
+ }
+ }
+}
+
+mod issue6818 {
+ #[derive(serde::Deserialize)]
+ struct A {
+ a: i32,
+ }
+}
+
+mod issue7206 {
+ struct MyStruct<const C: char>;
+ impl From<MyStruct<'a'>> for MyStruct<'b'> {
+ fn from(_s: MyStruct<'a'>) -> Self {
+ Self
+ }
+ }
+
+ // keep linting non-`Const` generic args
+ struct S<'a> {
+ inner: &'a str,
+ }
+
+ struct S2<T> {
+ inner: T,
+ }
+
+ impl<T> S2<T> {
+ fn new() -> Self {
+ unimplemented!();
+ }
+ }
+
+ impl<'a> S2<S<'a>> {
+ fn new_again() -> Self {
+ S2::new()
+ }
+ }
+}
+
+mod self_is_ty_param {
+ trait Trait {
+ type Type;
+ type Hi;
+
+ fn test();
+ }
+
+ impl<I> Trait for I
+ where
+ I: Iterator,
+ I::Item: Trait, // changing this to Self would require <Self as Iterator>
+ {
+ type Type = I;
+ type Hi = I::Item;
+
+ fn test() {
+ let _: I::Item;
+ let _: I; // this could lint, but is questionable
+ }
+ }
+}
+
+mod use_self_in_pat {
+ enum Foo {
+ Bar,
+ Baz,
+ }
+
+ impl Foo {
+ fn do_stuff(self) {
+ match self {
+ Foo::Bar => unimplemented!(),
+ Foo::Baz => unimplemented!(),
+ }
+ match Some(1) {
+ Some(_) => unimplemented!(),
+ None => unimplemented!(),
+ }
+ if let Foo::Bar = self {
+ unimplemented!()
+ }
+ }
+ }
+}
++
++mod issue8845 {
++ pub enum Something {
++ Num(u8),
++ TupleNums(u8, u8),
++ StructNums { one: u8, two: u8 },
++ }
++
++ struct Foo(u8);
++
++ struct Bar {
++ x: u8,
++ y: usize,
++ }
++
++ impl Something {
++ fn get_value(&self) -> u8 {
++ match self {
++ Something::Num(n) => *n,
++ Something::TupleNums(n, _m) => *n,
++ Something::StructNums { one, two: _ } => *one,
++ }
++ }
++
++ fn use_crate(&self) -> u8 {
++ match self {
++ crate::issue8845::Something::Num(n) => *n,
++ crate::issue8845::Something::TupleNums(n, _m) => *n,
++ crate::issue8845::Something::StructNums { one, two: _ } => *one,
++ }
++ }
++
++ fn imported_values(&self) -> u8 {
++ use Something::*;
++ match self {
++ Num(n) => *n,
++ TupleNums(n, _m) => *n,
++ StructNums { one, two: _ } => *one,
++ }
++ }
++ }
++
++ impl Foo {
++ fn get_value(&self) -> u8 {
++ let Foo(x) = self;
++ *x
++ }
++
++ fn use_crate(&self) -> u8 {
++ let crate::issue8845::Foo(x) = self;
++ *x
++ }
++ }
++
++ impl Bar {
++ fn get_value(&self) -> u8 {
++ let Bar { x, .. } = self;
++ *x
++ }
++
++ fn use_crate(&self) -> u8 {
++ let crate::issue8845::Bar { x, .. } = self;
++ *x
++ }
++ }
++}
--- /dev/null
- error: aborting due to 31 previous errors
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:22:21
+ |
+LL | fn new() -> Foo {
+ | ^^^ help: use the applicable keyword: `Self`
+ |
+ = note: `-D clippy::use-self` implied by `-D warnings`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:23:13
+ |
+LL | Foo {}
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:25:22
+ |
+LL | fn test() -> Foo {
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:26:13
+ |
+LL | Foo::new()
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:31:25
+ |
+LL | fn default() -> Foo {
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:32:13
+ |
+LL | Foo::new()
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:97:24
+ |
+LL | fn bad(foos: &[Foo]) -> impl Iterator<Item = &Foo> {
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:97:55
+ |
+LL | fn bad(foos: &[Foo]) -> impl Iterator<Item = &Foo> {
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:112:13
+ |
+LL | TS(0)
+ | ^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:147:29
+ |
+LL | fn bar() -> Bar {
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:148:21
+ |
+LL | Bar { foo: Foo {} }
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:159:21
+ |
+LL | fn baz() -> Foo {
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:160:13
+ |
+LL | Foo {}
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:177:21
+ |
+LL | let _ = Enum::B(42);
+ | ^^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:178:21
+ |
+LL | let _ = Enum::C { field: true };
+ | ^^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:179:21
+ |
+LL | let _ = Enum::A;
+ | ^^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:221:13
+ |
+LL | nested::A::fun_1();
+ | ^^^^^^^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:222:13
+ |
+LL | nested::A::A;
+ | ^^^^^^^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:224:13
+ |
+LL | nested::A {};
+ | ^^^^^^^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:243:13
+ |
+LL | TestStruct::from_something()
+ | ^^^^^^^^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:257:25
+ |
+LL | async fn g() -> S {
+ | ^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:258:13
+ |
+LL | S {}
+ | ^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:262:16
+ |
+LL | &p[S::A..S::B]
+ | ^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:262:22
+ |
+LL | &p[S::A..S::B]
+ | ^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:285:29
+ |
+LL | fn foo(value: T) -> Foo<T> {
+ | ^^^^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:286:13
+ |
+LL | Foo::<T> { value }
+ | ^^^^^^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:458:13
+ |
+LL | A::new::<submod::B>(submod::B {})
+ | ^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:495:13
+ |
+LL | S2::new()
+ | ^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:532:17
+ |
+LL | Foo::Bar => unimplemented!(),
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:533:17
+ |
+LL | Foo::Baz => unimplemented!(),
+ | ^^^ help: use the applicable keyword: `Self`
+
+error: unnecessary structure name repetition
+ --> $DIR/use_self.rs:539:20
+ |
+LL | if let Foo::Bar = self {
+ | ^^^ help: use the applicable keyword: `Self`
+
++error: unnecessary structure name repetition
++ --> $DIR/use_self.rs:563:17
++ |
++LL | Something::Num(n) => *n,
++ | ^^^^^^^^^ help: use the applicable keyword: `Self`
++
++error: unnecessary structure name repetition
++ --> $DIR/use_self.rs:564:17
++ |
++LL | Something::TupleNums(n, _m) => *n,
++ | ^^^^^^^^^ help: use the applicable keyword: `Self`
++
++error: unnecessary structure name repetition
++ --> $DIR/use_self.rs:565:17
++ |
++LL | Something::StructNums { one, two: _ } => *one,
++ | ^^^^^^^^^ help: use the applicable keyword: `Self`
++
++error: unnecessary structure name repetition
++ --> $DIR/use_self.rs:571:17
++ |
++LL | crate::issue8845::Something::Num(n) => *n,
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the applicable keyword: `Self`
++
++error: unnecessary structure name repetition
++ --> $DIR/use_self.rs:572:17
++ |
++LL | crate::issue8845::Something::TupleNums(n, _m) => *n,
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the applicable keyword: `Self`
++
++error: unnecessary structure name repetition
++ --> $DIR/use_self.rs:573:17
++ |
++LL | crate::issue8845::Something::StructNums { one, two: _ } => *one,
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the applicable keyword: `Self`
++
++error: unnecessary structure name repetition
++ --> $DIR/use_self.rs:589:17
++ |
++LL | let Foo(x) = self;
++ | ^^^ help: use the applicable keyword: `Self`
++
++error: unnecessary structure name repetition
++ --> $DIR/use_self.rs:594:17
++ |
++LL | let crate::issue8845::Foo(x) = self;
++ | ^^^^^^^^^^^^^^^^^^^^^ help: use the applicable keyword: `Self`
++
++error: unnecessary structure name repetition
++ --> $DIR/use_self.rs:601:17
++ |
++LL | let Bar { x, .. } = self;
++ | ^^^ help: use the applicable keyword: `Self`
++
++error: unnecessary structure name repetition
++ --> $DIR/use_self.rs:606:17
++ |
++LL | let crate::issue8845::Bar { x, .. } = self;
++ | ^^^^^^^^^^^^^^^^^^^^^ help: use the applicable keyword: `Self`
++
++error: aborting due to 41 previous errors
+
--- /dev/null
- if (theme == "ayu") {
- enableAyu = true;
- } else if (theme == "coal" || theme == "navy") {
- enableNight = true;
- } else if (theme == "rust") {
- enableHighlight = true;
- } else {
- enableHighlight = true;
- // this makes sure that an unknown theme request gets set to a known one
- theme = "light";
+(function () {
+ var md = window.markdownit({
+ html: true,
+ linkify: true,
+ typographer: true,
+ highlight: function (str, lang) {
+ if (lang && hljs.getLanguage(lang)) {
+ try {
+ return '<pre class="hljs"><code>' +
+ hljs.highlight(lang, str, true).value +
+ '</code></pre>';
+ } catch (__) {}
+ }
+
+ return '<pre class="hljs"><code>' + md.utils.escapeHtml(str) + '</code></pre>';
+ }
+ });
+
+ function scrollToLint(lintId) {
+ var target = document.getElementById(lintId);
+ if (!target) {
+ return;
+ }
+ target.scrollIntoView();
+ }
+
+ function scrollToLintByURL($scope) {
+ var removeListener = $scope.$on('ngRepeatFinished', function(ngRepeatFinishedEvent) {
+ scrollToLint(window.location.hash.slice(1));
+ removeListener();
+ });
+ }
+
+ function selectGroup($scope, selectedGroup) {
+ var groups = $scope.groups;
+ for (var group in groups) {
+ if (groups.hasOwnProperty(group)) {
+ if (group === selectedGroup) {
+ groups[group] = true;
+ } else {
+ groups[group] = false;
+ }
+ }
+ }
+ }
+
+ angular.module("clippy", [])
+ .filter('markdown', function ($sce) {
+ return function (text) {
+ return $sce.trustAsHtml(
+ md.render(text || '')
+ // Oh deer, what a hack :O
+ .replace('<table', '<table class="table"')
+ );
+ };
+ })
+ .directive('themeDropdown', function ($document) {
+ return {
+ restrict: 'A',
+ link: function ($scope, $element, $attr) {
+ $element.bind('click', function () {
+ $element.toggleClass('open');
+ $element.addClass('open-recent');
+ });
+
+ $document.bind('click', function () {
+ if (!$element.hasClass('open-recent')) {
+ $element.removeClass('open');
+ }
+ $element.removeClass('open-recent');
+ })
+ }
+ }
+ })
+ .directive('filterDropdown', function ($document) {
+ return {
+ restrict: 'A',
+ link: function ($scope, $element, $attr) {
+ $element.bind('click', function (event) {
+ if (event.target.closest('button')) {
+ $element.toggleClass('open');
+ } else {
+ $element.addClass('open');
+ }
+ $element.addClass('open-recent');
+ });
+
+ $document.bind('click', function () {
+ if (!$element.hasClass('open-recent')) {
+ $element.removeClass('open');
+ }
+ $element.removeClass('open-recent');
+ })
+ }
+ }
+ })
+ .directive('onFinishRender', function ($timeout) {
+ return {
+ restrict: 'A',
+ link: function (scope, element, attr) {
+ if (scope.$last === true) {
+ $timeout(function () {
+ scope.$emit(attr.onFinishRender);
+ });
+ }
+ }
+ };
+ })
+ .controller("lintList", function ($scope, $http, $timeout) {
+ // Level filter
+ var LEVEL_FILTERS_DEFAULT = {allow: true, warn: true, deny: true, none: true};
+ $scope.levels = LEVEL_FILTERS_DEFAULT;
+ $scope.byLevels = function (lint) {
+ return $scope.levels[lint.level];
+ };
+
+ var GROUPS_FILTER_DEFAULT = {
+ cargo: true,
+ complexity: true,
+ correctness: true,
+ deprecated: false,
+ nursery: true,
+ pedantic: true,
+ perf: true,
+ restriction: true,
+ style: true,
+ suspicious: true,
+ };
+ $scope.groups = GROUPS_FILTER_DEFAULT;
+ const THEMES_DEFAULT = {
+ light: "Light",
+ rust: "Rust",
+ coal: "Coal",
+ navy: "Navy",
+ ayu: "Ayu"
+ };
+ $scope.themes = THEMES_DEFAULT;
+
+ $scope.versionFilters = {
+ "≥": {enabled: false, minorVersion: null },
+ "≤": {enabled: false, minorVersion: null },
+ "=": {enabled: false, minorVersion: null },
+ };
+
+ $scope.selectTheme = function (theme) {
+ setTheme(theme, true);
+ }
+
+ $scope.toggleLevels = function (value) {
+ const levels = $scope.levels;
+ for (const key in levels) {
+ if (levels.hasOwnProperty(key)) {
+ levels[key] = value;
+ }
+ }
+ };
+
+ $scope.toggleGroups = function (value) {
+ const groups = $scope.groups;
+ for (const key in groups) {
+ if (groups.hasOwnProperty(key)) {
+ groups[key] = value;
+ }
+ }
+ };
+
+ $scope.selectedValuesCount = function (obj) {
+ return Object.values(obj).filter(x => x).length;
+ }
+
+ $scope.clearVersionFilters = function () {
+ for (let filter in $scope.versionFilters) {
+ $scope.versionFilters[filter] = { enabled: false, minorVersion: null };
+ }
+ }
+
+ $scope.versionFilterCount = function(obj) {
+ return Object.values(obj).filter(x => x.enabled).length;
+ }
+
+ $scope.updateVersionFilters = function() {
+ for (const filter in $scope.versionFilters) {
+ let minorVersion = $scope.versionFilters[filter].minorVersion;
+
+ // 1.29.0 and greater
+ if (minorVersion && minorVersion > 28) {
+ $scope.versionFilters[filter].enabled = true;
+ continue;
+ }
+
+ $scope.versionFilters[filter].enabled = false;
+ }
+ }
+
+ $scope.byVersion = function(lint) {
+ let filters = $scope.versionFilters;
+ for (const filter in filters) {
+ if (filters[filter].enabled) {
+ let minorVersion = filters[filter].minorVersion;
+
+ // Strip the "pre " prefix for pre 1.29.0 lints
+ let lintVersion = lint.version.startsWith("pre ") ? lint.version.substring(4, lint.version.length) : lint.version;
+ let lintMinorVersion = lintVersion.substring(2, 4);
+
+ switch (filter) {
+ // "=" gets the highest priority, since all filters are inclusive
+ case "=":
+ return (lintMinorVersion == minorVersion);
+ case "≥":
+ if (lintMinorVersion < minorVersion) { return false; }
+ break;
+ case "≤":
+ if (lintMinorVersion > minorVersion) { return false; }
+ break;
+ default:
+ return true
+ }
+ }
+ }
+
+ return true;
+ }
+
+ $scope.byGroups = function (lint) {
+ return $scope.groups[lint.group];
+ };
+
+ $scope.bySearch = function (lint, index, array) {
+ let searchStr = $scope.search;
+ // It can be `null` I haven't missed this value
+ if (searchStr == null || searchStr.length < 3) {
+ return true;
+ }
+ searchStr = searchStr.toLowerCase();
++ if (searchStr.startsWith("clippy::")) {
++ searchStr = searchStr.slice(8);
++ }
+
+ // Search by id
+ if (lint.id.indexOf(searchStr.replace("-", "_")) !== -1) {
+ return true;
+ }
+
+ // Search the description
+ // The use of `for`-loops instead of `foreach` enables us to return early
+ let terms = searchStr.split(" ");
+ let docsLowerCase = lint.docs.toLowerCase();
+ for (index = 0; index < terms.length; index++) {
+ // This is more likely and will therefor be checked first
+ if (docsLowerCase.indexOf(terms[index]) !== -1) {
+ continue;
+ }
+
+ if (lint.id.indexOf(terms[index]) !== -1) {
+ continue;
+ }
+
+ return false;
+ }
+
+ return true;
+ }
+
+ $scope.copyToClipboard = function (lint) {
+ const clipboard = document.getElementById("clipboard-" + lint.id);
+ if (clipboard) {
+ let resetClipboardTimeout = null;
+ let resetClipboardIcon = clipboard.innerHTML;
+
+ function resetClipboard() {
+ resetClipboardTimeout = null;
+ clipboard.innerHTML = resetClipboardIcon;
+ }
+
+ navigator.clipboard.writeText("clippy::" + lint.id);
+
+ clipboard.innerHTML = "✓";
+ if (resetClipboardTimeout !== null) {
+ clearTimeout(resetClipboardTimeout);
+ }
+ resetClipboardTimeout = setTimeout(resetClipboard, 1000);
+ }
+ }
+
+ // Get data
+ $scope.open = {};
+ $scope.loading = true;
+ // This will be used to jump into the source code of the version that this documentation is for.
+ $scope.docVersion = window.location.pathname.split('/')[2] || "master";
+
+ if (window.location.hash.length > 1) {
+ $scope.search = window.location.hash.slice(1);
+ $scope.open[window.location.hash.slice(1)] = true;
+ scrollToLintByURL($scope);
+ }
+
+ $http.get('./lints.json')
+ .success(function (data) {
+ $scope.data = data;
+ $scope.loading = false;
+
+ var selectedGroup = getQueryVariable("sel");
+ if (selectedGroup) {
+ selectGroup($scope, selectedGroup.toLowerCase());
+ }
+
+ scrollToLintByURL($scope);
+
+ setTimeout(function () {
+ var el = document.getElementById('filter-input');
+ if (el) { el.focus() }
+ }, 0);
+ })
+ .error(function (data) {
+ $scope.error = data;
+ $scope.loading = false;
+ });
+
+ window.addEventListener('hashchange', function () {
+ // trigger re-render
+ $timeout(function () {
+ $scope.levels = LEVEL_FILTERS_DEFAULT;
+ $scope.search = window.location.hash.slice(1);
+ $scope.open[window.location.hash.slice(1)] = true;
+
+ scrollToLintByURL($scope);
+ });
+ return true;
+ }, false);
+ });
+})();
+
+function getQueryVariable(variable) {
+ var query = window.location.search.substring(1);
+ var vars = query.split('&');
+ for (var i = 0; i < vars.length; i++) {
+ var pair = vars[i].split('=');
+ if (decodeURIComponent(pair[0]) == variable) {
+ return decodeURIComponent(pair[1]);
+ }
+ }
+}
+
+function setTheme(theme, store) {
+ let enableHighlight = false;
+ let enableNight = false;
+ let enableAyu = false;
+
- setTheme(localStorage.getItem('clippy-lint-list-theme'), false);
++ switch(theme) {
++ case "ayu":
++ enableAyu = true;
++ break;
++ case "coal":
++ case "navy":
++ enableNight = true;
++ break;
++ case "rust":
++ enableHighlight = true;
++ break;
++ default:
++ enableHighlight = true;
++ theme = "light";
++ break;
+ }
++
+ document.getElementsByTagName("body")[0].className = theme;
+
+ document.getElementById("styleHighlight").disabled = !enableHighlight;
+ document.getElementById("styleNight").disabled = !enableNight;
+ document.getElementById("styleAyu").disabled = !enableAyu;
+
+ if (store) {
+ try {
+ localStorage.setItem('clippy-lint-list-theme', theme);
+ } catch (e) { }
+ }
+}
+
+// loading the theme after the initial load
++const prefersDark = window.matchMedia("(prefers-color-scheme: dark)");
++const theme = localStorage.getItem('clippy-lint-list-theme');
++if (prefersDark.matches && !theme) {
++ setTheme("coal", false);
++} else {
++ setTheme(theme, false);
++}
projects / rust.git / commitdiff