--- /dev/null
+name: Clippy Test (bors)
+
+on:
+ push:
+ branches:
+ - auto
+ - try
+
+env:
+ RUST_BACKTRACE: 1
+ CARGO_TARGET_DIR: '${{ github.workspace }}/target'
+ NO_FMT_TEST: 1
+
+defaults:
+ run:
+ shell: bash
+
+jobs:
+ changelog:
+ runs-on: ubuntu-latest
+
+ steps:
+ - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
+ with:
+ github_token: "${{ secrets.github_token }}"
+
+ - name: Checkout
+ uses: actions/checkout@v3.0.2
+ with:
+ ref: ${{ github.ref }}
+
+ # Run
+ - name: Check Changelog
+ run: |
+ MESSAGE=$(git log --format=%B -n 1)
+ PR=$(echo "$MESSAGE" | grep -o "#[0-9]*" | head -1 | sed -e 's/^#//')
+ body=$(curl -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" -s "https://api.github.com/repos/rust-lang/rust-clippy/pulls/$PR" | \
+ python -c "import sys, json; print(json.load(sys.stdin)['body'])")
+ output=$(grep "^changelog:\s*\S" <<< "$body" | sed "s/changelog:\s*//g") || {
+ echo "ERROR: PR body must contain 'changelog: ...'"
+ exit 1
+ }
+ if [[ "$output" = "none" ]]; then
+ echo "WARNING: changelog is 'none'"
+ else
+ echo "changelog: $output"
+ fi
+ env:
+ PYTHONIOENCODING: 'utf-8'
+ base:
+ needs: changelog
+ strategy:
+ matrix:
+ os: [ubuntu-latest, windows-latest, macos-latest]
+ host: [x86_64-unknown-linux-gnu, i686-unknown-linux-gnu, x86_64-apple-darwin, x86_64-pc-windows-msvc]
+ exclude:
+ - os: ubuntu-latest
+ host: x86_64-apple-darwin
+ - os: ubuntu-latest
+ host: x86_64-pc-windows-msvc
+ - os: macos-latest
+ host: x86_64-unknown-linux-gnu
+ - os: macos-latest
+ host: i686-unknown-linux-gnu
+ - os: macos-latest
+ host: x86_64-pc-windows-msvc
+ - os: windows-latest
+ host: x86_64-unknown-linux-gnu
+ - os: windows-latest
+ host: i686-unknown-linux-gnu
+ - os: windows-latest
+ host: x86_64-apple-darwin
+
+ runs-on: ${{ matrix.os }}
+
+ # NOTE: If you modify this job, make sure you copy the changes to clippy.yml
+ steps:
+ # Setup
+ - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
+ with:
+ github_token: "${{ secrets.github_token }}"
+
+ - name: Install dependencies (Linux-i686)
+ run: |
+ sudo dpkg --add-architecture i386
+ sudo apt-get update
+ sudo apt-get install gcc-multilib libssl-dev:i386 libgit2-dev:i386
+ if: matrix.host == 'i686-unknown-linux-gnu'
+
+ - name: Checkout
+ uses: actions/checkout@v3.0.2
+
+ - name: Install toolchain
+ run: rustup show active-toolchain
+
+ # Run
+ - name: Set LD_LIBRARY_PATH (Linux)
+ if: runner.os == 'Linux'
+ run: |
+ SYSROOT=$(rustc --print sysroot)
+ echo "LD_LIBRARY_PATH=${SYSROOT}/lib${LD_LIBRARY_PATH+:${LD_LIBRARY_PATH}}" >> $GITHUB_ENV
+ - name: Link rustc dylib (MacOS)
+ if: runner.os == 'macOS'
+ run: |
+ SYSROOT=$(rustc --print sysroot)
+ sudo mkdir -p /usr/local/lib
+ sudo find "${SYSROOT}/lib" -maxdepth 1 -name '*dylib' -exec ln -s {} /usr/local/lib \;
+ - name: Set PATH (Windows)
+ if: runner.os == 'Windows'
+ run: |
+ SYSROOT=$(rustc --print sysroot)
+ echo "$SYSROOT/bin" >> $GITHUB_PATH
+
+ - name: Build
+ run: cargo build --features deny-warnings,internal
+
+ - name: Test
+ if: runner.os == 'Linux'
+ run: cargo test --features deny-warnings,internal
+
+ - name: Test
+ if: runner.os != 'Linux'
+ run: cargo test --features deny-warnings,internal -- --skip dogfood
+
+ - name: Test clippy_lints
+ run: cargo test --features deny-warnings,internal
+ working-directory: clippy_lints
+
+ - name: Test clippy_utils
+ run: cargo test --features deny-warnings,internal
+ working-directory: clippy_utils
+
+ - name: Test rustc_tools_util
+ run: cargo test --features deny-warnings
+ working-directory: rustc_tools_util
+
+ - name: Test clippy_dev
+ run: cargo test --features deny-warnings
+ working-directory: clippy_dev
+
+ - name: Test clippy-driver
+ run: bash .github/driver.sh
+ env:
+ OS: ${{ runner.os }}
+
++ metadata_collection:
++ needs: base
++ runs-on: ubuntu-latest
++
++ steps:
++ # Setup
++ - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
++ with:
++ github_token: "${{ secrets.github_token }}"
++
++ - name: Checkout
++ uses: actions/checkout@v3.0.2
++
++ - name: Install toolchain
++ run: rustup show active-toolchain
++
++ - name: Test metadata collection
++ run: cargo collect-metadata
++
+ integration_build:
+ needs: changelog
+ runs-on: ubuntu-latest
+
+ steps:
+ # Setup
+ - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
+ with:
+ github_token: "${{ secrets.github_token }}"
+
+ - name: Checkout
+ uses: actions/checkout@v3.0.2
+
+ - name: Install toolchain
+ run: rustup show active-toolchain
+
+ # Run
+ - name: Build Integration Test
+ run: cargo test --test integration --features integration --no-run
+
+ # Upload
+ - name: Extract Binaries
+ run: |
+ DIR=$CARGO_TARGET_DIR/debug
+ rm $DIR/deps/integration-*.d
+ mv $DIR/deps/integration-* $DIR/integration
+ find $DIR ! -executable -o -type d ! -path $DIR | xargs rm -rf
+ rm -rf $CARGO_TARGET_DIR/release
+
+ - name: Upload Binaries
+ uses: actions/upload-artifact@v1
+ with:
+ name: target
+ path: target
+
+ integration:
+ needs: integration_build
+ strategy:
+ fail-fast: false
+ max-parallel: 6
+ matrix:
+ integration:
+ - 'rust-lang/cargo'
+ # FIXME: re-enable once fmt_macros is renamed in RLS
+ # - 'rust-lang/rls'
+ - 'rust-lang/chalk'
+ - 'rust-lang/rustfmt'
+ - 'Marwes/combine'
+ - 'Geal/nom'
+ - 'rust-lang/stdarch'
+ - 'serde-rs/serde'
+ # FIXME: chrono currently cannot be compiled with `--all-targets`
+ # - 'chronotope/chrono'
+ - 'hyperium/hyper'
+ - 'rust-random/rand'
+ - 'rust-lang/futures-rs'
+ - 'rust-itertools/itertools'
+ - 'rust-lang-nursery/failure'
+ - 'rust-lang/log'
+
+ runs-on: ubuntu-latest
+
+ steps:
+ # Setup
+ - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
+ with:
+ github_token: "${{ secrets.github_token }}"
+
+ - name: Checkout
+ uses: actions/checkout@v3.0.2
+
+ - name: Install toolchain
+ run: rustup show active-toolchain
+
+ # Download
+ - name: Download target dir
+ uses: actions/download-artifact@v1
+ with:
+ name: target
+ path: target
+
+ - name: Make Binaries Executable
+ run: chmod +x $CARGO_TARGET_DIR/debug/*
+
+ # Run
+ - name: Test ${{ matrix.integration }}
+ run: |
+ RUSTUP_TOOLCHAIN="$(rustup show active-toolchain | grep -o -E "nightly-[0-9]{4}-[0-9]{2}-[0-9]{2}")" \
+ $CARGO_TARGET_DIR/debug/integration
+ env:
+ INTEGRATION: ${{ matrix.integration }}
+
+ # These jobs doesn't actually test anything, but they're only used to tell
+ # bors the build completed, as there is no practical way to detect when a
+ # workflow is successful listening to webhooks only.
+ #
+ # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
+
+ end-success:
+ name: bors test finished
+ if: github.event.pusher.name == 'bors' && success()
+ runs-on: ubuntu-latest
+ needs: [changelog, base, integration_build, integration]
+
+ steps:
+ - name: Mark the job as successful
+ run: exit 0
+
+ end-failure:
+ name: bors test finished
+ if: github.event.pusher.name == 'bors' && (failure() || cancelled())
+ runs-on: ubuntu-latest
+ needs: [changelog, base, integration_build, integration]
+
+ steps:
+ - name: Mark the job as a failure
+ run: exit 1
--- /dev/null
+name: Remark
+
+on:
+ push:
+ branches:
+ - auto
+ - try
+ pull_request:
+ paths:
+ - '**.md'
+
+jobs:
+ remark:
+ runs-on: ubuntu-latest
+
+ steps:
+ # Setup
+ - name: Checkout
+ uses: actions/checkout@v3.0.2
+
+ - name: Setup Node.js
+ uses: actions/setup-node@v1.4.4
+ with:
+ node-version: '12.x'
+
+ - name: Install remark
+ run: npm install remark-cli remark-lint remark-lint-maximum-line-length remark-preset-lint-recommended remark-gfm
+
++ - name: Install mdbook
++ run: |
++ mkdir mdbook
++ curl -Lf https://github.com/rust-lang/mdBook/releases/download/v0.4.18/mdbook-v0.4.18-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
++ echo `pwd`/mdbook >> $GITHUB_PATH
++
+ # Run
+ - name: Check *.md files
+ run: git ls-files -z '*.md' | xargs -0 -n 1 -I {} ./node_modules/.bin/remark {} -u lint -f > /dev/null
+
++ - name: Build mdbook
++ run: mdbook build book
++
+ # These jobs doesn't actually test anything, but they're only used to tell
+ # bors the build completed, as there is no practical way to detect when a
+ # workflow is successful listening to webhooks only.
+ #
+ # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
+
+ end-success:
+ name: bors remark test finished
+ if: github.event.pusher.name == 'bors' && success()
+ runs-on: ubuntu-latest
+ needs: [remark]
+
+ steps:
+ - name: Mark the job as successful
+ run: exit 0
+
+ end-failure:
+ name: bors remark test finished
+ if: github.event.pusher.name == 'bors' && (failure() || cancelled())
+ runs-on: ubuntu-latest
+ needs: [remark]
+
+ steps:
+ - name: Mark the job as a failure
+ run: exit 1
--- /dev/null
+# Used by CI to be able to push:
+/.github/deploy_key
+out
+
+# Compiled files
+*.o
+*.d
+*.so
+*.rlib
+*.dll
+*.pyc
+*.rmeta
+
+# Executables
+*.exe
+
+# Generated by Cargo
+*Cargo.lock
+/target
+/clippy_lints/target
+/clippy_utils/target
+/clippy_dev/target
+/lintcheck/target
+/rustc_tools_util/target
+
+# Generated by dogfood
+/target_recur/
+
+# Generated by lintcheck
+/lintcheck-logs
+
+# gh pages docs
+util/gh-pages/lints.json
+
+# rustfmt backups
+*.rs.bk
+
+helper.txt
+*.iml
+.vscode
+.idea
++
++# mdbook generated output
++/book/book
--- /dev/null
+# 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
+
+<!-- lint disable no-unused-definitions -->
+<!-- begin autogenerated links to lint list -->
+[`absurd_extreme_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#absurd_extreme_comparisons
+[`allow_attributes_without_reason`]: https://rust-lang.github.io/rust-clippy/master/index.html#allow_attributes_without_reason
+[`almost_complete_letter_range`]: https://rust-lang.github.io/rust-clippy/master/index.html#almost_complete_letter_range
+[`almost_swapped`]: https://rust-lang.github.io/rust-clippy/master/index.html#almost_swapped
+[`approx_constant`]: https://rust-lang.github.io/rust-clippy/master/index.html#approx_constant
+[`as_conversions`]: https://rust-lang.github.io/rust-clippy/master/index.html#as_conversions
+[`as_underscore`]: https://rust-lang.github.io/rust-clippy/master/index.html#as_underscore
+[`assertions_on_constants`]: https://rust-lang.github.io/rust-clippy/master/index.html#assertions_on_constants
+[`assign_op_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#assign_op_pattern
+[`assign_ops`]: https://rust-lang.github.io/rust-clippy/master/index.html#assign_ops
+[`async_yields_async`]: https://rust-lang.github.io/rust-clippy/master/index.html#async_yields_async
+[`await_holding_invalid_type`]: https://rust-lang.github.io/rust-clippy/master/index.html#await_holding_invalid_type
+[`await_holding_lock`]: https://rust-lang.github.io/rust-clippy/master/index.html#await_holding_lock
+[`await_holding_refcell_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#await_holding_refcell_ref
+[`bad_bit_mask`]: https://rust-lang.github.io/rust-clippy/master/index.html#bad_bit_mask
+[`bind_instead_of_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#bind_instead_of_map
+[`blacklisted_name`]: https://rust-lang.github.io/rust-clippy/master/index.html#blacklisted_name
+[`blanket_clippy_restriction_lints`]: https://rust-lang.github.io/rust-clippy/master/index.html#blanket_clippy_restriction_lints
+[`block_in_if_condition_expr`]: https://rust-lang.github.io/rust-clippy/master/index.html#block_in_if_condition_expr
+[`block_in_if_condition_stmt`]: https://rust-lang.github.io/rust-clippy/master/index.html#block_in_if_condition_stmt
+[`blocks_in_if_conditions`]: https://rust-lang.github.io/rust-clippy/master/index.html#blocks_in_if_conditions
+[`bool_assert_comparison`]: https://rust-lang.github.io/rust-clippy/master/index.html#bool_assert_comparison
+[`bool_comparison`]: https://rust-lang.github.io/rust-clippy/master/index.html#bool_comparison
+[`borrow_as_ptr`]: https://rust-lang.github.io/rust-clippy/master/index.html#borrow_as_ptr
+[`borrow_deref_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#borrow_deref_ref
+[`borrow_interior_mutable_const`]: https://rust-lang.github.io/rust-clippy/master/index.html#borrow_interior_mutable_const
+[`borrowed_box`]: https://rust-lang.github.io/rust-clippy/master/index.html#borrowed_box
+[`box_collection`]: https://rust-lang.github.io/rust-clippy/master/index.html#box_collection
+[`box_vec`]: https://rust-lang.github.io/rust-clippy/master/index.html#box_vec
+[`boxed_local`]: https://rust-lang.github.io/rust-clippy/master/index.html#boxed_local
+[`branches_sharing_code`]: https://rust-lang.github.io/rust-clippy/master/index.html#branches_sharing_code
+[`builtin_type_shadow`]: https://rust-lang.github.io/rust-clippy/master/index.html#builtin_type_shadow
+[`bytes_count_to_len`]: https://rust-lang.github.io/rust-clippy/master/index.html#bytes_count_to_len
+[`bytes_nth`]: https://rust-lang.github.io/rust-clippy/master/index.html#bytes_nth
+[`cargo_common_metadata`]: https://rust-lang.github.io/rust-clippy/master/index.html#cargo_common_metadata
+[`case_sensitive_file_extension_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#case_sensitive_file_extension_comparisons
+[`cast_abs_to_unsigned`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_abs_to_unsigned
+[`cast_enum_constructor`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_enum_constructor
+[`cast_enum_truncation`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_enum_truncation
+[`cast_lossless`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_lossless
+[`cast_possible_truncation`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_possible_truncation
+[`cast_possible_wrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_possible_wrap
+[`cast_precision_loss`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_precision_loss
+[`cast_ptr_alignment`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_ptr_alignment
+[`cast_ref_to_mut`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_ref_to_mut
+[`cast_sign_loss`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_sign_loss
+[`cast_slice_different_sizes`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_slice_different_sizes
+[`char_lit_as_u8`]: https://rust-lang.github.io/rust-clippy/master/index.html#char_lit_as_u8
+[`chars_last_cmp`]: https://rust-lang.github.io/rust-clippy/master/index.html#chars_last_cmp
+[`chars_next_cmp`]: https://rust-lang.github.io/rust-clippy/master/index.html#chars_next_cmp
+[`checked_conversions`]: https://rust-lang.github.io/rust-clippy/master/index.html#checked_conversions
+[`clone_double_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#clone_double_ref
+[`clone_on_copy`]: https://rust-lang.github.io/rust-clippy/master/index.html#clone_on_copy
+[`clone_on_ref_ptr`]: https://rust-lang.github.io/rust-clippy/master/index.html#clone_on_ref_ptr
+[`cloned_instead_of_copied`]: https://rust-lang.github.io/rust-clippy/master/index.html#cloned_instead_of_copied
+[`cmp_nan`]: https://rust-lang.github.io/rust-clippy/master/index.html#cmp_nan
+[`cmp_null`]: https://rust-lang.github.io/rust-clippy/master/index.html#cmp_null
+[`cmp_owned`]: https://rust-lang.github.io/rust-clippy/master/index.html#cmp_owned
+[`cognitive_complexity`]: https://rust-lang.github.io/rust-clippy/master/index.html#cognitive_complexity
+[`collapsible_else_if`]: https://rust-lang.github.io/rust-clippy/master/index.html#collapsible_else_if
+[`collapsible_if`]: https://rust-lang.github.io/rust-clippy/master/index.html#collapsible_if
+[`collapsible_match`]: https://rust-lang.github.io/rust-clippy/master/index.html#collapsible_match
+[`comparison_chain`]: https://rust-lang.github.io/rust-clippy/master/index.html#comparison_chain
+[`comparison_to_empty`]: https://rust-lang.github.io/rust-clippy/master/index.html#comparison_to_empty
+[`const_static_lifetime`]: https://rust-lang.github.io/rust-clippy/master/index.html#const_static_lifetime
+[`copy_iterator`]: https://rust-lang.github.io/rust-clippy/master/index.html#copy_iterator
+[`crate_in_macro_def`]: https://rust-lang.github.io/rust-clippy/master/index.html#crate_in_macro_def
+[`create_dir`]: https://rust-lang.github.io/rust-clippy/master/index.html#create_dir
+[`crosspointer_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#crosspointer_transmute
+[`cyclomatic_complexity`]: https://rust-lang.github.io/rust-clippy/master/index.html#cyclomatic_complexity
+[`dbg_macro`]: https://rust-lang.github.io/rust-clippy/master/index.html#dbg_macro
+[`debug_assert_with_mut_call`]: https://rust-lang.github.io/rust-clippy/master/index.html#debug_assert_with_mut_call
+[`decimal_literal_representation`]: https://rust-lang.github.io/rust-clippy/master/index.html#decimal_literal_representation
+[`declare_interior_mutable_const`]: https://rust-lang.github.io/rust-clippy/master/index.html#declare_interior_mutable_const
+[`default_numeric_fallback`]: https://rust-lang.github.io/rust-clippy/master/index.html#default_numeric_fallback
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+[`tabs_in_doc_comments`]: https://rust-lang.github.io/rust-clippy/master/index.html#tabs_in_doc_comments
+[`temporary_assignment`]: https://rust-lang.github.io/rust-clippy/master/index.html#temporary_assignment
+[`temporary_cstring_as_ptr`]: https://rust-lang.github.io/rust-clippy/master/index.html#temporary_cstring_as_ptr
+[`to_digit_is_some`]: https://rust-lang.github.io/rust-clippy/master/index.html#to_digit_is_some
+[`to_string_in_display`]: https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_display
+[`to_string_in_format_args`]: https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_format_args
+[`todo`]: https://rust-lang.github.io/rust-clippy/master/index.html#todo
+[`too_many_arguments`]: https://rust-lang.github.io/rust-clippy/master/index.html#too_many_arguments
+[`too_many_lines`]: https://rust-lang.github.io/rust-clippy/master/index.html#too_many_lines
+[`toplevel_ref_arg`]: https://rust-lang.github.io/rust-clippy/master/index.html#toplevel_ref_arg
+[`trailing_empty_array`]: https://rust-lang.github.io/rust-clippy/master/index.html#trailing_empty_array
+[`trait_duplication_in_bounds`]: https://rust-lang.github.io/rust-clippy/master/index.html#trait_duplication_in_bounds
+[`transmute_bytes_to_str`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_bytes_to_str
+[`transmute_float_to_int`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_float_to_int
+[`transmute_int_to_bool`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_int_to_bool
+[`transmute_int_to_char`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_int_to_char
+[`transmute_int_to_float`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_int_to_float
+[`transmute_num_to_bytes`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_num_to_bytes
+[`transmute_ptr_to_ptr`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_ptr_to_ptr
+[`transmute_ptr_to_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_ptr_to_ref
+[`transmute_undefined_repr`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
+[`transmutes_expressible_as_ptr_casts`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmutes_expressible_as_ptr_casts
+[`transmuting_null`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmuting_null
+[`trim_split_whitespace`]: https://rust-lang.github.io/rust-clippy/master/index.html#trim_split_whitespace
+[`trivial_regex`]: https://rust-lang.github.io/rust-clippy/master/index.html#trivial_regex
+[`trivially_copy_pass_by_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#trivially_copy_pass_by_ref
+[`try_err`]: https://rust-lang.github.io/rust-clippy/master/index.html#try_err
+[`type_complexity`]: https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity
+[`type_repetition_in_bounds`]: https://rust-lang.github.io/rust-clippy/master/index.html#type_repetition_in_bounds
+[`undocumented_unsafe_blocks`]: https://rust-lang.github.io/rust-clippy/master/index.html#undocumented_unsafe_blocks
+[`undropped_manually_drops`]: https://rust-lang.github.io/rust-clippy/master/index.html#undropped_manually_drops
+[`unicode_not_nfc`]: https://rust-lang.github.io/rust-clippy/master/index.html#unicode_not_nfc
+[`unimplemented`]: https://rust-lang.github.io/rust-clippy/master/index.html#unimplemented
+[`uninit_assumed_init`]: https://rust-lang.github.io/rust-clippy/master/index.html#uninit_assumed_init
+[`uninit_vec`]: https://rust-lang.github.io/rust-clippy/master/index.html#uninit_vec
+[`unit_arg`]: https://rust-lang.github.io/rust-clippy/master/index.html#unit_arg
+[`unit_cmp`]: https://rust-lang.github.io/rust-clippy/master/index.html#unit_cmp
+[`unit_hash`]: https://rust-lang.github.io/rust-clippy/master/index.html#unit_hash
+[`unit_return_expecting_ord`]: https://rust-lang.github.io/rust-clippy/master/index.html#unit_return_expecting_ord
+[`unknown_clippy_lints`]: https://rust-lang.github.io/rust-clippy/master/index.html#unknown_clippy_lints
+[`unnecessary_cast`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
+[`unnecessary_filter_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_filter_map
+[`unnecessary_find_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_find_map
+[`unnecessary_fold`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_fold
+[`unnecessary_join`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_join
+[`unnecessary_lazy_evaluations`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_lazy_evaluations
+[`unnecessary_mut_passed`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_mut_passed
+[`unnecessary_operation`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_operation
+[`unnecessary_owned_empty_strings`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_owned_empty_strings
+[`unnecessary_self_imports`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_self_imports
+[`unnecessary_sort_by`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_sort_by
+[`unnecessary_to_owned`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_to_owned
+[`unnecessary_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_unwrap
+[`unnecessary_wraps`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_wraps
+[`unneeded_field_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#unneeded_field_pattern
+[`unneeded_wildcard_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#unneeded_wildcard_pattern
+[`unnested_or_patterns`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnested_or_patterns
+[`unreachable`]: https://rust-lang.github.io/rust-clippy/master/index.html#unreachable
+[`unreadable_literal`]: https://rust-lang.github.io/rust-clippy/master/index.html#unreadable_literal
+[`unsafe_derive_deserialize`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsafe_derive_deserialize
+[`unsafe_removed_from_name`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsafe_removed_from_name
+[`unsafe_vector_initialization`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsafe_vector_initialization
+[`unseparated_literal_suffix`]: https://rust-lang.github.io/rust-clippy/master/index.html#unseparated_literal_suffix
+[`unsound_collection_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsound_collection_transmute
+[`unstable_as_mut_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#unstable_as_mut_slice
+[`unstable_as_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#unstable_as_slice
+[`unused_async`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_async
+[`unused_collect`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_collect
+[`unused_io_amount`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_io_amount
+[`unused_label`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_label
+[`unused_rounding`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_rounding
+[`unused_self`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_self
+[`unused_unit`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_unit
+[`unusual_byte_groupings`]: https://rust-lang.github.io/rust-clippy/master/index.html#unusual_byte_groupings
+[`unwrap_in_result`]: https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_in_result
+[`unwrap_or_else_default`]: https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_or_else_default
+[`unwrap_used`]: https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_used
+[`upper_case_acronyms`]: https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
+[`use_debug`]: https://rust-lang.github.io/rust-clippy/master/index.html#use_debug
+[`use_self`]: https://rust-lang.github.io/rust-clippy/master/index.html#use_self
+[`used_underscore_binding`]: https://rust-lang.github.io/rust-clippy/master/index.html#used_underscore_binding
+[`useless_asref`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_asref
+[`useless_attribute`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_attribute
+[`useless_conversion`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion
+[`useless_format`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
+[`useless_let_if_seq`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_let_if_seq
+[`useless_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_transmute
+[`useless_vec`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
+[`vec_box`]: https://rust-lang.github.io/rust-clippy/master/index.html#vec_box
+[`vec_init_then_push`]: https://rust-lang.github.io/rust-clippy/master/index.html#vec_init_then_push
+[`vec_resize_to_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#vec_resize_to_zero
+[`verbose_bit_mask`]: https://rust-lang.github.io/rust-clippy/master/index.html#verbose_bit_mask
+[`verbose_file_reads`]: https://rust-lang.github.io/rust-clippy/master/index.html#verbose_file_reads
+[`vtable_address_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#vtable_address_comparisons
+[`while_immutable_condition`]: https://rust-lang.github.io/rust-clippy/master/index.html#while_immutable_condition
+[`while_let_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#while_let_loop
+[`while_let_on_iterator`]: https://rust-lang.github.io/rust-clippy/master/index.html#while_let_on_iterator
+[`wildcard_dependencies`]: https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_dependencies
+[`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
- - [Getting started](#getting-started)
- - [High level approach](#high-level-approach)
- - [Finding something to fix/improve](#finding-something-to-fiximprove)
+# Contributing to Clippy
+
+Hello fellow Rustacean! Great to see your interest in compiler internals and lints!
+
+**First**: if you're unsure or afraid of _anything_, just ask or submit the issue or pull request anyway. You won't be
+yelled at for giving it your best effort. The worst that can happen is that you'll be politely asked to change
+something. We appreciate any sort of contributions, and don't want a wall of rules to get in the way of that.
+
+Clippy welcomes contributions from everyone. There are many ways to contribute to Clippy and the following document
+explains how you can contribute and how to get started. If you have any questions about contributing or need help with
+anything, feel free to ask questions on issues or visit the `#clippy` on [Zulip].
+
+All contributors are expected to follow the [Rust Code of Conduct].
+
+- [Contributing to Clippy](#contributing-to-clippy)
- - [Syncing changes between Clippy and `rust-lang/rust`](#syncing-changes-between-clippy-and-rust-langrust)
- - [Patching git-subtree to work with big repos](#patching-git-subtree-to-work-with-big-repos)
- - [Performing the sync from `rust-lang/rust` to Clippy](#performing-the-sync-from-rust-langrust-to-clippy)
- - [Performing the sync from Clippy to `rust-lang/rust`](#performing-the-sync-from-clippy-to-rust-langrust)
- - [Defining remotes](#defining-remotes)
++ - [The Clippy book](#the-clippy-book)
++ - [High level approach](#high-level-approach)
++ - [Finding something to fix/improve](#finding-something-to-fiximprove)
+ - [Writing code](#writing-code)
+ - [Getting code-completion for rustc internals to work](#getting-code-completion-for-rustc-internals-to-work)
+ - [IntelliJ Rust](#intellij-rust)
+ - [Rust Analyzer](#rust-analyzer)
+ - [How Clippy works](#how-clippy-works)
- ## Getting started
+ - [Issue and PR triage](#issue-and-pr-triage)
+ - [Bors and Homu](#bors-and-homu)
+ - [Contributions](#contributions)
+
+[Zulip]: https://rust-lang.zulipchat.com/#narrow/stream/clippy
+[Rust Code of Conduct]: https://www.rust-lang.org/policies/code-of-conduct
+
- **Note: If this is your first time contributing to Clippy, you should
- first read the [Basics docs](doc/basics.md).**
++## The Clippy book
+
- ### High level approach
++If you're new to Clippy and don't know where to start the [Clippy book] includes
++a developer guide and is a good place to start your journey.
+
- 3. Follow the instructions in the [Basics docs](doc/basics.md) to get set up
++<!-- FIXME: Link to the deployed book, once it is deployed through CI -->
++[Clippy book]: book/src
++
++## High level approach
+
+1. Find something to fix/improve
+2. Change code (likely some file in `clippy_lints/src/`)
- ### Finding something to fix/improve
++3. Follow the instructions in the [Basics docs](book/src/development/basics.md)
++ to get set up
+4. Run `cargo test` in the root directory and wiggle code until it passes
+5. Open a PR (also can be done after 2. if you run into problems)
+
- All issues on Clippy are mentored, if you want help simply ask @Manishearth, @flip1995, @phansch
- or @llogiq directly by mentioning them in the issue or over on [Zulip]. This list may be out of date.
- All currently active mentors can be found [here](https://github.com/rust-lang/highfive/blob/master/highfive/configs/rust-lang/rust-clippy.json#L3)
++## Finding something to fix/improve
+
- ## Writing code
-
- Have a look at the [docs for writing lints][adding_lints] for more details.
-
- If you want to add a new lint or change existing ones apart from bugfixing, it's
- also a good idea to give the [stability guarantees][rfc_stability] and
- [lint categories][rfc_lint_cats] sections of the [Clippy 1.0 RFC][clippy_rfc] a
- quick read.
-
- [adding_lints]: https://github.com/rust-lang/rust-clippy/blob/master/doc/adding_lints.md
- [clippy_rfc]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md
- [rfc_stability]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#stability-guarantees
- [rfc_lint_cats]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#lint-audit-and-categories
-
++All issues on Clippy are mentored, if you want help simply ask someone from the
++Clippy team directly by mentioning them in the issue or over on [Zulip]. All
++currently active team members can be found
++[here](https://github.com/rust-lang/highfive/blob/master/highfive/configs/rust-lang/rust-clippy.json#L3)
+
+Some issues are easier than others. The [`good-first-issue`] label can be used to find the easy
+issues. You can use `@rustbot claim` to assign the issue to yourself.
+
+There are also some abandoned PRs, marked with [`S-inactive-closed`].
+Pretty often these PRs are nearly completed and just need some extra steps
+(formatting, addressing review comments, ...) to be merged. If you want to
+complete such a PR, please leave a comment in the PR and open a new one based
+on it.
+
+Issues marked [`T-AST`] involve simple matching of the syntax tree structure,
+and are generally easier than [`T-middle`] issues, which involve types
+and resolved paths.
+
+[`T-AST`] issues will generally need you to match against a predefined syntax structure.
+To figure out how this syntax structure is encoded in the AST, it is recommended to run
+`rustc -Z unpretty=ast-tree` on an example of the structure and compare with the [nodes in the AST docs].
+Usually the lint will end up to be a nested series of matches and ifs, [like so][deep-nesting].
+But we can make it nest-less by using [let chains], [like this][nest-less].
+
+[`E-medium`] issues are generally pretty easy too, though it's recommended you work on an [`good-first-issue`]
+first. Sometimes they are only somewhat involved code wise, but not difficult per-se.
+Note that [`E-medium`] issues may require some knowledge of Clippy internals or some
+debugging to find the actual problem behind the issue.
+
+[`T-middle`] issues can be more involved and require verifying types. The [`ty`] module contains a
+lot of methods that are useful, though one of the most useful would be `expr_ty` (gives the type of
+an AST expression). `match_def_path()` in Clippy's `utils` module can also be useful.
+
+[`good-first-issue`]: https://github.com/rust-lang/rust-clippy/labels/good-first-issue
+[`S-inactive-closed`]: https://github.com/rust-lang/rust-clippy/pulls?q=is%3Aclosed+label%3AS-inactive-closed
+[`T-AST`]: https://github.com/rust-lang/rust-clippy/labels/T-AST
+[`T-middle`]: https://github.com/rust-lang/rust-clippy/labels/T-middle
+[`E-medium`]: https://github.com/rust-lang/rust-clippy/labels/E-medium
+[`ty`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty
+[nodes in the AST docs]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/ast/
+[deep-nesting]: https://github.com/rust-lang/rust-clippy/blob/5e4f0922911536f80d9591180fa604229ac13939/clippy_lints/src/mem_forget.rs#L31-L45
+[let chains]: https://github.com/rust-lang/rust/pull/94927
+[nest-less]: https://github.com/rust-lang/rust-clippy/blob/5e4f0922911536f80d9591180fa604229ac13939/clippy_lints/src/bit_mask.rs#L133-L159
+
- ## Syncing changes between Clippy and [`rust-lang/rust`]
-
- Clippy currently gets built with a pinned nightly version.
-
- In the `rust-lang/rust` repository, where rustc resides, there's a copy of Clippy
- that compiler hackers modify from time to time to adapt to changes in the unstable
- API of the compiler.
-
- We need to sync these changes back to this repository periodically, and the changes
- made to this repository in the meantime also need to be synced to the `rust-lang/rust` repository.
-
- To avoid flooding the `rust-lang/rust` PR queue, this two-way sync process is done
- in a bi-weekly basis if there's no urgent changes. This is done starting on the day of
- the Rust stable release and then every other week. That way we guarantee that we keep
- this repo up to date with the latest compiler API, and every feature in Clippy is available
- for 2 weeks in nightly, before it can get to beta. For reference, the first sync
- following this cadence was performed the 2020-08-27.
-
- This process is described in detail in the following sections. For general information
- about `subtree`s in the Rust repository see [Rust's `CONTRIBUTING.md`][subtree].
-
- ### Patching git-subtree to work with big repos
-
- Currently, there's a bug in `git-subtree` that prevents it from working properly
- with the [`rust-lang/rust`] repo. There's an open PR to fix that, but it's stale.
- Before continuing with the following steps, we need to manually apply that fix to
- our local copy of `git-subtree`.
-
- You can get the patched version of `git-subtree` from [here][gitgitgadget-pr].
- Put this file under `/usr/lib/git-core` (taking a backup of the previous file)
- and make sure it has the proper permissions:
-
- ```bash
- sudo cp --backup /path/to/patched/git-subtree.sh /usr/lib/git-core/git-subtree
- sudo chmod --reference=/usr/lib/git-core/git-subtree~ /usr/lib/git-core/git-subtree
- sudo chown --reference=/usr/lib/git-core/git-subtree~ /usr/lib/git-core/git-subtree
- ```
-
- _Note:_ The first time running `git subtree push` a cache has to be built. This
- involves going through the complete Clippy history once. For this you have to
- increase the stack limit though, which you can do with `ulimit -s 60000`.
- Make sure to run the `ulimit` command from the same session you call git subtree.
-
- _Note:_ If you are a Debian user, `dash` is the shell used by default for scripts instead of `sh`.
- This shell has a hardcoded recursion limit set to 1000. In order to make this process work,
- you need to force the script to run `bash` instead. You can do this by editing the first
- line of the `git-subtree` script and changing `sh` to `bash`.
-
- ### Performing the sync from [`rust-lang/rust`] to Clippy
-
- Here is a TL;DR version of the sync process (all of the following commands have
- to be run inside the `rust` directory):
-
- 1. Clone the [`rust-lang/rust`] repository or make sure it is up to date.
- 2. Checkout the commit from the latest available nightly. You can get it using `rustup check`.
- 3. Sync the changes to the rust-copy of Clippy to your Clippy fork:
- ```bash
- # Make sure to change `your-github-name` to your github name in the following command. Also be
- # sure to either use a net-new branch, e.g. `sync-from-rust`, or delete the branch beforehand
- # because changes cannot be fast forwarded
- git subtree push -P src/tools/clippy git@github.com:your-github-name/rust-clippy sync-from-rust
- ```
-
- _Note:_ This will directly push to the remote repository. You can also push
- to your local copy by replacing the remote address with `/path/to/rust-clippy`
- directory.
-
- _Note:_ Most of the time you have to create a merge commit in the
- `rust-clippy` repo (this has to be done in the Clippy repo, not in the
- rust-copy of Clippy):
- ```bash
- git fetch origin && git fetch upstream
- git checkout sync-from-rust
- git merge upstream/master
- ```
- 4. Open a PR to `rust-lang/rust-clippy` and wait for it to get merged (to
- accelerate the process ping the `@rust-lang/clippy` team in your PR and/or
- ~~annoy~~ ask them in the [Zulip] stream.)
-
- ### Performing the sync from Clippy to [`rust-lang/rust`]
-
- All of the following commands have to be run inside the `rust` directory.
-
- 1. Make sure Clippy itself is up-to-date by following the steps outlined in the previous
- section if necessary.
-
- 2. Sync the `rust-lang/rust-clippy` master to the rust-copy of Clippy:
- ```bash
- git checkout -b sync-from-clippy
- git subtree pull -P src/tools/clippy https://github.com/rust-lang/rust-clippy master
- ```
- 3. Open a PR to [`rust-lang/rust`]
-
- ### Defining remotes
-
- You may want to define remotes, so you don't have to type out the remote
- addresses on every sync. You can do this with the following commands (these
- commands still have to be run inside the `rust` directory):
-
- ```bash
- # Set clippy-upstream remote for pulls
- $ git remote add clippy-upstream https://github.com/rust-lang/rust-clippy
- # Make sure to not push to the upstream repo
- $ git remote set-url --push clippy-upstream DISABLED
- # Set clippy-origin remote to your fork for pushes
- $ git remote add clippy-origin git@github.com:your-github-name/rust-clippy
- # Set a local remote
- $ git remote add clippy-local /path/to/rust-clippy
- ```
-
- You can then sync with the remote names from above, e.g.:
-
- ```bash
- $ git subtree push -P src/tools/clippy clippy-local sync-from-rust
- ```
-
- [gitgitgadget-pr]: https://github.com/gitgitgadget/git/pull/493
- [subtree]: https://rustc-dev-guide.rust-lang.org/contributing.html#external-dependencies-subtree
- [`rust-lang/rust`]: https://github.com/rust-lang/rust
-
+## Getting code-completion for rustc internals to work
+
+### IntelliJ Rust
+Unfortunately, [`IntelliJ Rust`][IntelliJ_rust_homepage] does not (yet?) understand how Clippy uses compiler-internals
+using `extern crate` and it also needs to be able to read the source files of the rustc-compiler which are not
+available via a `rustup` component at the time of writing.
+To work around this, you need to have a copy of the [rustc-repo][rustc_repo] available which can be obtained via
+`git clone https://github.com/rust-lang/rust/`.
+Then you can run a `cargo dev` command to automatically make Clippy use the rustc-repo via path-dependencies
+which `IntelliJ Rust` will be able to understand.
+Run `cargo dev setup intellij --repo-path <repo-path>` where `<repo-path>` is a path to the rustc repo
+you just cloned.
+The command will add path-dependencies pointing towards rustc-crates inside the rustc repo to
+Clippy's `Cargo.toml`s and should allow `IntelliJ Rust` to understand most of the types that Clippy uses.
+Just make sure to remove the dependencies again before finally making a pull request!
+
+[rustc_repo]: https://github.com/rust-lang/rust/
+[IntelliJ_rust_homepage]: https://intellij-rust.github.io/
+
+### Rust Analyzer
+As of [#6869][6869], [`rust-analyzer`][ra_homepage] can understand that Clippy uses compiler-internals
+using `extern crate` when `package.metadata.rust-analyzer.rustc_private` is set to `true` in Clippy's `Cargo.toml.`
+You will require a `nightly` toolchain with the `rustc-dev` component installed.
+Make sure that in the `rust-analyzer` configuration, you set
+```
+{ "rust-analyzer.rustcSource": "discover" }
+```
+and
+```
+{ "rust-analyzer.updates.channel": "nightly" }
+```
+You should be able to see information on things like `Expr` or `EarlyContext` now if you hover them, also
+a lot more type hints.
+This will work with `rust-analyzer 2021-03-15` shipped in nightly `1.52.0-nightly (107896c32 2021-03-15)` or later.
+
+[ra_homepage]: https://rust-analyzer.github.io/
+[6869]: https://github.com/rust-lang/rust-clippy/pull/6869
+
+## How Clippy works
+
+[`clippy_lints/src/lib.rs`][lint_crate_entry] imports all the different lint modules and registers in the [`LintStore`].
+For example, the [`else_if_without_else`][else_if_without_else] lint is registered like this:
+
+```rust
+// ./clippy_lints/src/lib.rs
+
+// ...
+pub mod else_if_without_else;
+// ...
+
+pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &Conf) {
+ // ...
+ store.register_early_pass(|| box else_if_without_else::ElseIfWithoutElse);
+ // ...
+
+ store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![
+ // ...
+ LintId::of(&else_if_without_else::ELSE_IF_WITHOUT_ELSE),
+ // ...
+ ]);
+}
+```
+
+The [`rustc_lint::LintStore`][`LintStore`] provides two methods to register lints:
+[register_early_pass][reg_early_pass] and [register_late_pass][reg_late_pass]. Both take an object
+that implements an [`EarlyLintPass`][early_lint_pass] or [`LateLintPass`][late_lint_pass] respectively. This is done in
+every single lint. It's worth noting that the majority of `clippy_lints/src/lib.rs` is autogenerated by `cargo dev
+update_lints`. When you are writing your own lint, you can use that script to save you some time.
+
+```rust
+// ./clippy_lints/src/else_if_without_else.rs
+
+use rustc_lint::{EarlyLintPass, EarlyContext};
+
+// ...
+
+pub struct ElseIfWithoutElse;
+
+// ...
+
+impl EarlyLintPass for ElseIfWithoutElse {
+ // ... the functions needed, to make the lint work
+}
+```
+
+The difference between `EarlyLintPass` and `LateLintPass` is that the methods of the `EarlyLintPass` trait only provide
+AST information. The methods of the `LateLintPass` trait are executed after type checking and contain type information
+via the `LateContext` parameter.
+
+That's why the `else_if_without_else` example uses the `register_early_pass` function. Because the
+[actual lint logic][else_if_without_else] does not depend on any type information.
+
+[lint_crate_entry]: https://github.com/rust-lang/rust-clippy/blob/master/clippy_lints/src/lib.rs
+[else_if_without_else]: https://github.com/rust-lang/rust-clippy/blob/4253aa7137cb7378acc96133c787e49a345c2b3c/clippy_lints/src/else_if_without_else.rs
+[`LintStore`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/struct.LintStore.html
+[reg_early_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/struct.LintStore.html#method.register_early_pass
+[reg_late_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/struct.LintStore.html#method.register_late_pass
+[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
+
+## Issue and PR triage
+
+Clippy is following the [Rust triage procedure][triage] for issues and pull
+requests.
+
+However, we are a smaller project with all contributors being volunteers
+currently. Between writing new lints, fixing issues, reviewing pull requests and
+responding to issues there may not always be enough time to stay on top of it
+all.
+
+Our highest priority is fixing [crashes][l-crash] and [bugs][l-bug], for example
+an ICE in a popular crate that many other crates depend on. We don't
+want Clippy to crash on your code and we want it to be as reliable as the
+suggestions from Rust compiler errors.
+
+We have prioritization labels and a sync-blocker label, which are described below.
+- [P-low][p-low]: Requires attention (fix/response/evaluation) by a team member but isn't urgent.
+- [P-medium][p-medium]: Should be addressed by a team member until the next sync.
+- [P-high][p-high]: Should be immediately addressed and will require an out-of-cycle sync or a backport.
+- [L-sync-blocker][l-sync-blocker]: An issue that "blocks" a sync.
+Or rather: before the sync this should be addressed,
+e.g. by removing a lint again, so it doesn't hit beta/stable.
+
+## Bors and Homu
+
+We use a bot powered by [Homu][homu] to help automate testing and landing of pull
+requests in Clippy. The bot's username is @bors.
+
+You can find the Clippy bors queue [here][homu_queue].
+
+If you have @bors permissions, you can find an overview of the available
+commands [here][homu_instructions].
+
+[triage]: https://forge.rust-lang.org/release/triage-procedure.html
+[l-crash]: https://github.com/rust-lang/rust-clippy/labels/L-crash
+[l-bug]: https://github.com/rust-lang/rust-clippy/labels/L-bug
+[p-low]: https://github.com/rust-lang/rust-clippy/labels/P-low
+[p-medium]: https://github.com/rust-lang/rust-clippy/labels/P-medium
+[p-high]: https://github.com/rust-lang/rust-clippy/labels/P-high
+[l-sync-blocker]: https://github.com/rust-lang/rust-clippy/labels/L-sync-blocker
+[homu]: https://github.com/rust-lang/homu
+[homu_instructions]: https://bors.rust-lang.org/
+[homu_queue]: https://bors.rust-lang.org/queue/clippy
+
+## Contributions
+
+Contributions to Clippy should be made in the form of GitHub pull requests. Each pull request will
+be reviewed by a core contributor (someone with permission to land patches) and either landed in the
+main tree or given feedback for changes that would be required.
+
+All code in this repository is under the [Apache-2.0] or the [MIT] license.
+
+<!-- adapted from https://github.com/servo/servo/blob/master/CONTRIBUTING.md -->
+
+[Apache-2.0]: https://www.apache.org/licenses/LICENSE-2.0
+[MIT]: https://opensource.org/licenses/MIT
--- /dev/null
- internal = ["clippy_lints/internal"]
+[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]
+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
+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", "tempfile"]
+
+[package.metadata.rust-analyzer]
+# This package uses #[feature(rustc_private)]
+rustc_private = true
--- /dev/null
--- /dev/null
++# Clippy Book
++
++This is the source for the Clippy Book. See the
++[book](src/infrastructure/book.md) for more information.
--- /dev/null
--- /dev/null
++[book]
++authors = ["The Rust Clippy Developers"]
++language = "en"
++multilingual = false
++src = "src"
++title = "Clippy Documentation"
++
++[rust]
++edition = "2018"
++
++[output.html]
++edit-url-template = "https://github.com/rust-lang/rust-clippy/edit/master/book/{path}"
++git-repository-url = "https://github.com/rust-lang/rust-clippy/tree/master/book"
++mathjax-support = true
++site-url = "/rust-clippy/"
++
++[output.html.playground]
++editable = true
++line-numbers = true
++
++[output.html.search]
++boost-hierarchy = 2
++boost-paragraph = 1
++boost-title = 2
++expand = true
++heading-split-level = 2
++limit-results = 20
++use-boolean-and = true
--- /dev/null
--- /dev/null
++# Clippy
++
++[](https://github.com/rust-lang/rust-clippy/actions?query=workflow%3A%22Clippy+Test%22+event%3Apush+branch%3Aauto)
++[](#license)
++
++A collection of lints to catch common mistakes and improve your
++[Rust](https://github.com/rust-lang/rust) code.
++
++[There are over 500 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
++
++Lints are divided into categories, each with a default [lint
++level](https://doc.rust-lang.org/rustc/lints/levels.html). You can choose how
++much Clippy is supposed to ~~annoy~~ help you by changing the lint level by
++category.
++
++| Category | Description | Default level |
++| --------------------- | ----------------------------------------------------------------------------------- | ------------- |
++| `clippy::all` | all lints that are on by default (correctness, suspicious, style, complexity, perf) | **warn/deny** |
++| `clippy::correctness` | code that is outright wrong or useless | **deny** |
++| `clippy::suspicious` | code that is most likely wrong or useless | **warn** |
++| `clippy::complexity` | code that does something simple but in a complex way | **warn** |
++| `clippy::perf` | code that can be written to run faster | **warn** |
++| `clippy::style` | code that should be written in a more idiomatic way | **warn** |
++| `clippy::pedantic` | lints which are rather strict or might have false positives | allow |
++| `clippy::nursery` | new lints that are still under development | allow |
++| `clippy::cargo` | lints for the cargo manifest | allow | | allow |
++
++More to come, please [file an
++issue](https://github.com/rust-lang/rust-clippy/issues) if you have ideas!
++
++The [lint list](https://rust-lang.github.io/rust-clippy/master/index.html) also
++contains "restriction lints", which are for things which are usually not
++considered "bad", but may be useful to turn on in specific cases. These should
++be used very selectively, if at all.
--- /dev/null
--- /dev/null
++# Summary
++
++[Introduction](README.md)
++
++- [Installation](installation.md)
++- [Usage](usage.md)
++- [Configuration](configuration.md)
++- [Clippy's Lints](lints.md)
++- [Continuous Integration](continuous_integration/README.md)
++ - [GitHub Actions](continuous_integration/github_actions.md)
++ - [Travis CI](continuous_integration/travis.md)
++- [Development](development/README.md)
++ - [Basics](development/basics.md)
++ - [Adding Lints](development/adding_lints.md)
++ - [Common Tools](development/common_tools_writing_lints.md)
++ - [Infrastructure](development/infrastructure/README.md)
++ - [Syncing changes between Clippy and rust-lang/rust](development/infrastructure/sync.md)
++ - [Backporting Changes](development/infrastructure/backport.md)
++ - [Updating the Changelog](development/infrastructure/changelog_update.md)
++ - [Release a New Version](development/infrastructure/release.md)
++ - [The Clippy Book](development/infrastructure/book.md)
++ - [Proposals](development/proposals/README.md)
++ - [Roadmap 2021](development/proposals/roadmap-2021.md)
--- /dev/null
--- /dev/null
++# Configuring Clippy
++
++> **Note:** The configuration file is unstable and may be deprecated in the future.
++
++Some lints can be configured in a TOML file named `clippy.toml` or `.clippy.toml`. It contains a
++basic `variable = value` mapping eg.
++
++```toml
++avoid-breaking-exported-api = false
++blacklisted-names = ["toto", "tata", "titi"]
++cognitive-complexity-threshold = 30
++```
++
++See the [list of lints](https://rust-lang.github.io/rust-clippy/master/index.html) for more information about which
++lints can be configured and the meaning of the variables.
++
++To deactivate the "for further information visit *lint-link*" message you can define the `CLIPPY_DISABLE_DOCS_LINKS`
++environment variable.
++
++### Allowing/denying lints
++
++You can add options to your code to `allow`/`warn`/`deny` Clippy lints:
++
++* the whole set of `Warn` lints using the `clippy` lint group (`#![deny(clippy::all)]`)
++
++* all lints using both the `clippy` and `clippy::pedantic` lint groups (`#![deny(clippy::all)]`,
++ `#![deny(clippy::pedantic)]`). Note that `clippy::pedantic` contains some very aggressive lints prone to false
++ positives.
++
++* only some lints (`#![deny(clippy::single_match, clippy::box_vec)]`, etc.)
++
++* `allow`/`warn`/`deny` can be limited to a single function or module using `#[allow(...)]`, etc.
++
++Note: `allow` means to suppress the lint for your code. With `warn` the lint will only emit a warning, while with `deny`
++the lint will emit an error, when triggering for your code. An error causes clippy to exit with an error code, so is
++useful in scripts like CI/CD.
++
++If you do not want to include your lint levels in your code, you can globally enable/disable lints by passing extra
++flags to Clippy during the run:
++
++To allow `lint_name`, run
++
++```terminal
++cargo clippy -- -A clippy::lint_name
++```
++
++And to warn on `lint_name`, run
++
++```terminal
++cargo clippy -- -W clippy::lint_name
++```
++
++This also works with lint groups. For example you can run Clippy with warnings for all lints enabled:
++
++```terminal
++cargo clippy -- -W clippy::pedantic
++```
++
++If you care only about a single lint, you can allow all others and then explicitly warn on the lint(s) you are
++interested in:
++
++```terminal
++cargo clippy -- -A clippy::all -W clippy::useless_format -W clippy::...
++```
++
++### Specifying the minimum supported Rust version
++
++Projects that intend to support old versions of Rust can disable lints pertaining to newer features by specifying the
++minimum supported Rust version (MSRV) in the clippy configuration file.
++
++```toml
++msrv = "1.30.0"
++```
++
++The MSRV can also be specified as an inner attribute, like below.
++
++```rust
++#![feature(custom_inner_attributes)]
++#![clippy::msrv = "1.30.0"]
++
++fn main() {
++ ...
++}
++```
++
++You can also omit the patch version when specifying the MSRV, so `msrv = 1.30`
++is equivalent to `msrv = 1.30.0`.
++
++Note: `custom_inner_attributes` is an unstable feature so it has to be enabled explicitly.
++
++Lints that recognize this configuration option can be
++found [here](https://rust-lang.github.io/rust-clippy/master/index.html#msrv)
--- /dev/null
--- /dev/null
++# Continuous Integration
++
++It is recommended to run Clippy on CI with `-Dwarnings`, so that Clippy lints
++prevent CI from passing. To enforce errors on warnings on all `cargo` commands
++not just `cargo clippy`, you can set the env var `RUSTFLAGS="-Dwarnings"`.
++
++We recommend to use Clippy from the same toolchain, that you use for compiling
++your crate for maximum compatibility. E.g. if your crate is compiled with the
++`stable` toolchain, you should also use `stable` Clippy.
++
++> _Note:_ New Clippy lints are first added to the `nightly` toolchain. If you
++> want to help with improving Clippy and have CI resources left, please consider
++> adding a `nightly` Clippy check to your CI and report problems like false
++> positives back to us. With that we can fix bugs early, before they can get to
++> stable.
++
++This chapter will give an overview on how to use Clippy on different popular CI
++providers.
--- /dev/null
--- /dev/null
++# GitHub Actions
++
++On the GitHub hosted runners, Clippy from the latest stable Rust version comes
++pre-installed. So all you have to do is to run `cargo clippy`.
++
++```yml
++on: push
++name: Clippy check
++
++# Make sure CI fails on all warnings, including Clippy lints
++env:
++ RUSTFLAGS: "-Dwarnings"
++
++jobs:
++ clippy_check:
++ runs-on: ubuntu-latest
++ steps:
++ - uses: actions/checkout@v1
++ - name: Run Clippy
++ run: cargo clippy --all-targets --all-features
++```
--- /dev/null
--- /dev/null
++# Travis CI
++
++You can add Clippy to Travis CI in the same way you use it locally:
++
++```yml
++language: rust
++rust:
++ - stable
++ - beta
++before_script:
++ - rustup component add clippy
++script:
++ - cargo clippy
++ # if you want the build job to fail when encountering warnings, use
++ - cargo clippy -- -D warnings
++ # in order to also check tests and non-default crate features, use
++ - cargo clippy --all-targets --all-features -- -D warnings
++ - cargo test
++ # etc.
++```
--- /dev/null
--- /dev/null
++# Clippy Development
++
++Hello fellow Rustacean! If you made it here, you're probably interested in
++making Clippy better by contributing to it. In that case, welcome to the
++project!
++
++> _Note:_ If you're just interested in using Clippy, there's nothing to see from
++> this point onward and you should return to one of the earlier chapters.
++
++## Getting started
++
++If this is your first time contributing to Clippy, you should first read the
++[Basics docs](basics.md). This will explain the basics on how to get the source
++code and how to compile and test the code.
++
++## Writing code
++
++If you have done the basic setup, it's time to start hacking.
++
++The [Adding lints](adding_lints.md) chapter is a walk through on how to add a
++new lint to Clippy. This is also interesting if you just want to fix a lint,
++because it also covers how to test lints and gives an overview of the bigger
++picture.
++
++If you want to add a new lint or change existing ones apart from bugfixing, it's
++also a good idea to give the [stability guarantees][rfc_stability] and
++[lint categories][rfc_lint_cats] sections of the [Clippy 1.0 RFC][clippy_rfc] a
++quick read. The lint categories are also described [earlier in this
++book](../lints.md).
++
++> _Note:_ Some higher level things about contributing to Clippy are still
++> covered in the [`CONTRIBUTING.md`] document. Some of those will be moved to
++> the book over time, like:
++> - Finding something to fix
++> - IDE setup
++> - High level overview on how Clippy works
++> - Triage procedure
++> - Bors and Homu
++
++[clippy_rfc]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md
++[rfc_stability]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#stability-guarantees
++[rfc_lint_cats]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#lint-audit-and-categories
++[`CONTRIBUTING.md`]: https://github.com/rust-lang/rust-clippy/blob/master/CONTRIBUTING.md
--- /dev/null
--- /dev/null
++# 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:_ 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
++
++## 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
--- /dev/null
++# Basics for hacking on Clippy
++
++This document explains the basics for hacking on Clippy. Besides others, this
++includes how to build and test Clippy. For a more in depth description on the
++codebase take a look at [Adding Lints] or [Common Tools].
++
++[Adding Lints]: https://github.com/rust-lang/rust-clippy/blob/master/doc/adding_lints.md
++[Common Tools]: https://github.com/rust-lang/rust-clippy/blob/master/doc/common_tools_writing_lints.md
++
++- [Basics for hacking on Clippy](#basics-for-hacking-on-clippy)
++ - [Get the Code](#get-the-code)
++ - [Building and Testing](#building-and-testing)
++ - [`cargo dev`](#cargo-dev)
++ - [lintcheck](#lintcheck)
++ - [PR](#pr)
++ - [Common Abbreviations](#common-abbreviations)
++ - [Install from source](#install-from-source)
++
++## Get the Code
++
++First, make sure you have checked out the latest version of Clippy. If this is
++your first time working on Clippy, create a fork of the repository and clone it
++afterwards with the following command:
++
++```bash
++git clone git@github.com:<your-username>/rust-clippy
++```
++
++If you've already cloned Clippy in the past, update it to the latest version:
++
++```bash
++# If the upstream remote has not been added yet
++git remote add upstream https://github.com/rust-lang/rust-clippy
++# upstream has to be the remote of the rust-lang/rust-clippy repo
++git fetch upstream
++# make sure that you are on the master branch
++git checkout master
++# rebase your master branch on the upstream master
++git rebase upstream/master
++# push to the master branch of your fork
++git push
++```
++
++## Building and Testing
++
++You can build and test Clippy like every other Rust project:
++
++```bash
++cargo build # builds Clippy
++cargo test # tests Clippy
++```
++
++Since Clippy's test suite is pretty big, there are some commands that only run a
++subset of Clippy's tests:
++
++```bash
++# only run UI tests
++cargo uitest
++# only run UI tests starting with `test_`
++TESTNAME="test_" cargo uitest
++# only run dogfood tests
++cargo test --test dogfood
++```
++
++If the output of a [UI test] differs from the expected output, you can update
++the reference file with:
++
++```bash
++cargo dev bless
++```
++
++For example, this is necessary, if you fix a typo in an error message of a lint
++or if you modify a test file to add a test case.
++
++> _Note:_ This command may update more files than you intended. In that case
++> only commit the files you wanted to update.
++
++[UI test]: https://rustc-dev-guide.rust-lang.org/tests/adding.html#guide-to-the-ui-tests
++
++## `cargo dev`
++
++Clippy has some dev tools to make working on Clippy more convenient. These tools
++can be accessed through the `cargo dev` command. Available tools are listed
++below. To get more information about these commands, just call them with
++`--help`.
++
++```bash
++# formats the whole Clippy codebase and all tests
++cargo dev fmt
++# register or update lint names/groups/...
++cargo dev update_lints
++# create a new lint and register it
++cargo dev new_lint
++# automatically formatting all code before each commit
++cargo dev setup git-hook
++# (experimental) Setup Clippy to work with IntelliJ-Rust
++cargo dev setup intellij
++```
++
++More about intellij command usage and reasons
++[here](../CONTRIBUTING.md#intellij-rust)
++
++## lintcheck
++
++`cargo lintcheck` will build and run clippy on a fixed set of crates and
++generate a log of the results. You can `git diff` the updated log against its
++previous version and see what impact your lint made on a small set of crates.
++If you add a new lint, please audit the resulting warnings and make sure there
++are no false positives and that the suggestions are valid.
++
++Refer to the tools [README] for more details.
++
++[README]: https://github.com/rust-lang/rust-clippy/blob/master/lintcheck/README.md
++
++## PR
++
++We follow a rustc no merge-commit policy. See
++<https://rustc-dev-guide.rust-lang.org/contributing.html#opening-a-pr>.
++
++## Common Abbreviations
++
++| Abbreviation | Meaning |
++| ------------ | -------------------------------------- |
++| UB | Undefined Behavior |
++| FP | False Positive |
++| FN | False Negative |
++| ICE | Internal Compiler Error |
++| AST | Abstract Syntax Tree |
++| MIR | Mid-Level Intermediate Representation |
++| HIR | High-Level Intermediate Representation |
++| TCX | Type context |
++
++This is a concise list of abbreviations that can come up during Clippy
++development. An extensive general list can be found in the [rustc-dev-guide
++glossary][glossary]. Always feel free to ask if an abbreviation or meaning is
++unclear to you.
++
++## Install from source
++
++If you are hacking on Clippy and want to install it from source, do the
++following:
++
++First, take note of the toolchain
++[override](https://rust-lang.github.io/rustup/overrides.html) in
++`/rust-toolchain`. We will use this override to install Clippy into the right
++toolchain.
++
++> Tip: You can view the active toolchain for the current directory with `rustup
++> show active-toolchain`.
++
++From the Clippy project root, run the following command to build the Clippy
++binaries and copy them into the toolchain directory. This will override the
++currently installed Clippy component.
++
++```terminal
++cargo build --release --bin cargo-clippy --bin clippy-driver -Zunstable-options --out-dir "$(rustc --print=sysroot)/bin"
++```
++
++Now you may run `cargo clippy` in any project, using the toolchain where you
++just installed Clippy.
++
++```terminal
++cd my-project
++cargo +nightly-2021-07-01 clippy
++```
++
++...or `clippy-driver`
++
++```terminal
++clippy-driver +nightly-2021-07-01 <filename>
++```
++
++If you need to restore the default Clippy installation, run the following (from
++the Clippy project root).
++
++```terminal
++rustup component remove clippy
++rustup component add clippy
++```
++
++> **DO NOT** install using `cargo install --path . --force` since this will
++> overwrite rustup
++> [proxies](https://rust-lang.github.io/rustup/concepts/proxies.html). That is,
++> `~/.cargo/bin/cargo-clippy` and `~/.cargo/bin/clippy-driver` should be hard or
++> soft links to `~/.cargo/bin/rustup`. You can repair these by running `rustup
++> update`.
++
++[glossary]: https://rustc-dev-guide.rust-lang.org/appendix/glossary.html
--- /dev/null
--- /dev/null
++# 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
--- /dev/null
++# Infrastructure
++
++In order to deploy Clippy over `rustup`, some infrastructure is necessary. This
++chapter describes the different parts of the Clippy infrastructure that need to
++be maintained to make this possible.
++
++The most important part is the sync between the `rust-lang/rust` repository and
++the Clippy repository that takes place every two weeks. This process is
++described in the [Syncing changes between Clippy and `rust-lang/rust`](sync.md)
++section.
++
++A new Clippy release is done together with every Rust release, so every six
++weeks. The release process is described in the [Release a new Clippy
++Version](release.md) section. During a release cycle a changelog entry for the
++next release has to be written. The format of that and how to do that is
++documented in the [Changelog Update](changelog_update.md) section.
++
++> _Note:_ The Clippy CI should also be described in this chapter, but for now is
++> left as a TODO.
--- /dev/null
--- /dev/null
++# Backport Changes
++
++Sometimes it is necessary to backport changes to the beta release of Clippy.
++Backports in Clippy are rare and should be approved by the Clippy team. For
++example, a backport is done, if a crucial ICE was fixed or a lint is broken to a
++point, that it has to be disabled, before landing on stable.
++
++Backports are done to the `beta` branch of Clippy. Backports to stable Clippy
++releases basically don't exist, since this would require a Rust point release,
++which is almost never justifiable for a Clippy fix.
++
++
++## Backport the changes
++
++Backports are done on the beta branch of the Clippy repository.
++
++```bash
++# Assuming the current directory corresponds to the Clippy repository
++$ git checkout beta
++$ git checkout -b backport
++$ git cherry-pick <SHA> # `<SHA>` is the commit hash of the commit(s), that should be backported
++$ git push origin backport
++```
++
++Now you should test that the backport passes all the tests in the Rust
++repository. You can do this with:
++
++```bash
++# Assuming the current directory corresponds to the Rust repository
++$ git checkout beta
++$ git subtree pull -p src/tools/clippy https://github.com/<your-github-name>/rust-clippy backport
++$ ./x.py test src/tools/clippy
++```
++
++Should the test fail, you can fix Clippy directly in the Rust repository. This
++has to be first applied to the Clippy beta branch and then again synced to the
++Rust repository, though. The easiest way to do this is:
++
++```bash
++# In the Rust repository
++$ git diff --patch --relative=src/tools/clippy > clippy.patch
++# In the Clippy repository
++$ git apply /path/to/clippy.patch
++$ git add -u
++$ git commit -m "Fix rustup fallout"
++$ git push origin backport
++```
++
++After this, you can open a PR to the `beta` branch of the Clippy repository.
++
++
++## Update Clippy in the Rust Repository
++
++This step must be done, **after** the PR of the previous step was merged.
++
++After the backport landed in the Clippy repository, the branch has to be synced
++back to the beta branch of the Rust repository.
++
++```bash
++# Assuming the current directory corresponds to the Rust repository
++$ git checkout beta
++$ git checkout -b clippy_backport
++$ git subtree pull -p src/tools/clippy https://github.com/rust-lang/rust-clippy beta
++$ git push origin clippy_backport
++```
++
++Make sure to test the backport in the Rust repository before opening a PR. This
++is done with `./x.py test src/tools/clippy`. If that passes all tests, open a PR
++to the `beta` branch of the Rust repository. In this PR you should tag the
++Clippy team member, that agreed to the backport or the `@rust-lang/clippy` team.
++Make sure to add `[beta]` to the title of the PR.
--- /dev/null
--- /dev/null
++# The Clippy Book
++
++This document explains how to make additions and changes to the Clippy book, the
++guide to Clippy that you're reading right now. The Clippy book is formatted with
++[Markdown](https://www.markdownguide.org) and generated by
++[mdbook](https://github.com/rust-lang/mdBook).
++
++- [Get mdbook](#get-mdbook)
++- [Make changes](#make-changes)
++
++## Get mdbook
++
++While not strictly necessary since the book source is simply Markdown text
++files, having mdbook locally will allow you to build, test and serve the book
++locally to view changes before you commit them to the repository. You likely
++already have `cargo` installed, so the easiest option is to simply:
++
++```shell
++cargo install mdbook
++```
++
++See the mdbook [installation](https://github.com/rust-lang/mdBook#installation)
++instructions for other options.
++
++## Make changes
++
++The book's
++[src](https://github.com/joshrotenberg/rust-clippy/tree/clippy_guide/book/src)
++directory contains all of the markdown files used to generate the book. If you
++want to see your changes in real time, you can use the mdbook `serve` command to
++run a web server locally that will automatically update changes as they are
++made. From the top level of your `rust-clippy` directory:
++
++```shell
++mdbook serve book --open
++```
++
++Then navigate to `http://localhost:3000` to see the generated book. While the
++server is running, changes you make will automatically be updated.
++
++For more information, see the mdbook
++[guide](https://rust-lang.github.io/mdBook/).
--- /dev/null
--- /dev/null
++# Changelog Update
++
++If you want to help with updating the [changelog], you're in the right place.
++
++## When to update
++
++Typos and other small fixes/additions are _always_ welcome.
++
++Special care needs to be taken when it comes to updating the changelog for a new
++Rust release. For that purpose, the changelog is ideally updated during the week
++before an upcoming stable release. You can find the release dates on the [Rust
++Forge][forge].
++
++Most of the time we only need to update the changelog for minor Rust releases.
++It's been very rare that Clippy changes were included in a patch release.
++
++## Changelog update walkthrough
++
++### 1. Finding the relevant Clippy commits
++
++Each Rust release ships with its own version of Clippy. The Clippy subtree can
++be found in the `tools` directory of the Rust repository.
++
++Depending on the current time and what exactly you want to update, the following
++bullet points might be helpful:
++
++* When writing the release notes for the **upcoming stable release** you need to
++ check out the Clippy commit of the current Rust `beta` branch.
++ [Link][rust_beta_tools]
++* When writing the release notes for the **upcoming beta release**, you need to
++ check out the Clippy commit of the current Rust `master`.
++ [Link][rust_master_tools]
++* When writing the (forgotten) release notes for a **past stable release**, you
++ need to check out the Rust release tag of the stable release.
++ [Link][rust_stable_tools]
++
++Usually you want to write the changelog of the **upcoming stable release**. Make
++sure though, that `beta` was already branched in the Rust repository.
++
++To find the commit hash, issue the following command when in a `rust-lang/rust`
++checkout:
++```
++git log --oneline -- src/tools/clippy/ | grep -o "Merge commit '[a-f0-9]*' into .*" | head -1 | sed -e "s/Merge commit '\([a-f0-9]*\)' into .*/\1/g"
++```
++
++### 2. Fetching the PRs between those commits
++
++Once you've got the correct commit range, run
++
++```
++util/fetch_prs_between.sh commit1 commit2 > changes.txt
++```
++
++and open that file in your editor of choice.
++
++When updating the changelog it's also a good idea to make sure that `commit1` is
++already correct in the current changelog.
++
++### 3. Authoring the final changelog
++
++The above script should have dumped all the relevant PRs to the file you
++specified. It should have filtered out most of the irrelevant PRs already, but
++it's a good idea to do a manual cleanup pass where you look for more irrelevant
++PRs. If you're not sure about some PRs, just leave them in for the review and
++ask for feedback.
++
++With the PRs filtered, you can start to take each PR and move the `changelog: `
++content to `CHANGELOG.md`. Adapt the wording as you see fit but try to keep it
++somewhat coherent.
++
++The order should roughly be:
++
++1. New lints
++2. Moves or deprecations of lints
++3. Changes that expand what code existing lints cover
++4. False positive fixes
++5. Suggestion fixes/improvements
++6. ICE fixes
++7. Documentation improvements
++8. Others
++
++As section headers, we use:
++
++```
++### New Lints
++### Moves and Deprecations
++### Enhancements
++### False Positive Fixes
++### Suggestion Fixes/Improvements
++### ICE Fixes
++### Documentation Improvements
++### Others
++```
++
++Please also be sure to update the Beta/Unreleased sections at the top with the
++relevant commit ranges.
++
++[changelog]: https://github.com/rust-lang/rust-clippy/blob/master/CHANGELOG.md
++[forge]: https://forge.rust-lang.org/
++[rust_master_tools]: https://github.com/rust-lang/rust/tree/master/src/tools/clippy
++[rust_beta_tools]: https://github.com/rust-lang/rust/tree/beta/src/tools/clippy
++[rust_stable_tools]: https://github.com/rust-lang/rust/releases
--- /dev/null
--- /dev/null
++# Release a new Clippy Version
++
++> _NOTE:_ This document is probably only relevant to you, if you're a member of
++> the Clippy team.
++
++Clippy is released together with stable Rust releases. The dates for these
++releases can be found at the [Rust Forge]. This document explains the necessary
++steps to create a Clippy release.
++
++1. [Remerge the `beta` branch](#remerge-the-beta-branch)
++2. [Update the `beta` branch](#update-the-beta-branch)
++3. [Find the Clippy commit](#find-the-clippy-commit)
++4. [Tag the stable commit](#tag-the-stable-commit)
++5. [Update `CHANGELOG.md`](#update-changelogmd)
++
++> _NOTE:_ This document is for stable Rust releases, not for point releases. For
++> point releases, step 1. and 2. should be enough.
++
++[Rust Forge]: https://forge.rust-lang.org/
++
++## Remerge the `beta` branch
++
++This step is only necessary, if since the last release something was backported
++to the beta Rust release. The remerge is then necessary, to make sure that the
++Clippy commit, that was used by the now stable Rust release, persists in the
++tree of the Clippy repository.
++
++To find out if this step is necessary run
++
++```bash
++# Assumes that the local master branch of rust-lang/rust-clippy is up-to-date
++$ git fetch upstream
++$ git branch master --contains upstream/beta
++```
++
++If this command outputs `master`, this step is **not** necessary.
++
++```bash
++# Assuming `HEAD` is the current `master` branch of rust-lang/rust-clippy
++$ git checkout -b backport_remerge
++$ git merge upstream/beta
++$ git diff # This diff has to be empty, otherwise something with the remerge failed
++$ git push origin backport_remerge # This can be pushed to your fork
++```
++
++After this, open a PR to the master branch. In this PR, the commit hash of the
++`HEAD` of the `beta` branch must exists. In addition to that, no files should be
++changed by this PR.
++
++## Update the `beta` branch
++
++This step must be done **after** the PR of the previous step was merged.
++
++First, the Clippy commit of the `beta` branch of the Rust repository has to be
++determined.
++
++```bash
++# Assuming the current directory corresponds to the Rust repository
++$ git fetch upstream
++$ git checkout upstream/beta
++$ BETA_SHA=$(git log --oneline -- src/tools/clippy/ | grep -o "Merge commit '[a-f0-9]*' into .*" | head -1 | sed -e "s/Merge commit '\([a-f0-9]*\)' into .*/\1/g")
++```
++
++After finding the Clippy commit, the `beta` branch in the Clippy repository can
++be updated.
++
++```bash
++# Assuming the current directory corresponds to the Clippy repository
++$ git checkout beta
++$ git reset --hard $BETA_SHA
++$ git push upstream beta
++```
++
++## Find the Clippy commit
++
++The first step is to tag the Clippy commit, that is included in the stable Rust
++release. This commit can be found in the Rust repository.
++
++```bash
++# Assuming the current directory corresponds to the Rust repository
++$ git fetch upstream # `upstream` is the `rust-lang/rust` remote
++$ git checkout 1.XX.0 # XX should be exchanged with the corresponding version
++$ SHA=$(git log --oneline -- src/tools/clippy/ | grep -o "Merge commit '[a-f0-9]*' into .*" | head -1 | sed -e "s/Merge commit '\([a-f0-9]*\)' into .*/\1/g")
++```
++
++## Tag the stable commit
++
++After finding the Clippy commit, it can be tagged with the release number.
++
++```bash
++# Assuming the current directory corresponds to the Clippy repository
++$ git checkout $SHA
++$ git tag rust-1.XX.0 # XX should be exchanged with the corresponding version
++$ git push upstream rust-1.XX.0 # `upstream` is the `rust-lang/rust-clippy` remote
++```
++
++After this, the release should be available on the Clippy [release page].
++
++[release page]: https://github.com/rust-lang/rust-clippy/releases
++
++## Update the `stable` branch
++
++At this step you should have already checked out the commit of the `rust-1.XX.0`
++tag. Updating the stable branch from here is as easy as:
++
++```bash
++# Assuming the current directory corresponds to the Clippy repository and the
++# commit of the just created rust-1.XX.0 tag is checked out.
++$ git push upstream rust-1.XX.0:stable # `upstream` is the `rust-lang/rust-clippy` remote
++```
++
++> _NOTE:_ Usually there are no stable backports for Clippy, so this update
++> should be possible without force pushing or anything like this. If there
++> should have happened a stable backport, make sure to re-merge those changes
++> just as with the `beta` branch.
++
++## Update `CHANGELOG.md`
++
++For this see the document on [how to update the changelog].
++
++If you don't have time to do a complete changelog update right away, just update
++the following parts:
++
++- Remove the `(beta)` from the new stable version:
++
++ ```markdown
++ ## Rust 1.XX (beta) -> ## Rust 1.XX
++ ```
++
++- Update the release date line of the new stable version:
++
++ ```markdown
++ Current beta, release 20YY-MM-DD -> Current stable, released 20YY-MM-DD
++ ```
++
++- Update the release date line of the previous stable version:
++
++ ```markdown
++ Current stable, released 20YY-MM-DD -> Released 20YY-MM-DD
++ ```
++
++[how to update the changelog]: changelog_update.md
--- /dev/null
--- /dev/null
++# Syncing changes between Clippy and [`rust-lang/rust`]
++
++Clippy currently gets built with a pinned nightly version.
++
++In the `rust-lang/rust` repository, where rustc resides, there's a copy of
++Clippy that compiler hackers modify from time to time to adapt to changes in the
++unstable API of the compiler.
++
++We need to sync these changes back to this repository periodically, and the
++changes made to this repository in the meantime also need to be synced to the
++`rust-lang/rust` repository.
++
++To avoid flooding the `rust-lang/rust` PR queue, this two-way sync process is
++done in a bi-weekly basis if there's no urgent changes. This is done starting on
++the day of the Rust stable release and then every other week. That way we
++guarantee that we keep this repo up to date with the latest compiler API, and
++every feature in Clippy is available for 2 weeks in nightly, before it can get
++to beta. For reference, the first sync following this cadence was performed the
++2020-08-27.
++
++This process is described in detail in the following sections. For general
++information about `subtree`s in the Rust repository see [Rust's
++`CONTRIBUTING.md`][subtree].
++
++## Patching git-subtree to work with big repos
++
++Currently, there's a bug in `git-subtree` that prevents it from working properly
++with the [`rust-lang/rust`] repo. There's an open PR to fix that, but it's
++stale. Before continuing with the following steps, we need to manually apply
++that fix to our local copy of `git-subtree`.
++
++You can get the patched version of `git-subtree` from [here][gitgitgadget-pr].
++Put this file under `/usr/lib/git-core` (making a backup of the previous file)
++and make sure it has the proper permissions:
++
++```bash
++sudo cp --backup /path/to/patched/git-subtree.sh /usr/lib/git-core/git-subtree
++sudo chmod --reference=/usr/lib/git-core/git-subtree~ /usr/lib/git-core/git-subtree
++sudo chown --reference=/usr/lib/git-core/git-subtree~ /usr/lib/git-core/git-subtree
++```
++
++> _Note:_ The first time running `git subtree push` a cache has to be built.
++> This involves going through the complete Clippy history once. For this you
++> have to increase the stack limit though, which you can do with `ulimit -s
++> 60000`. Make sure to run the `ulimit` command from the same session you call
++> git subtree.
++
++> _Note:_ If you are a Debian user, `dash` is the shell used by default for
++> scripts instead of `sh`. This shell has a hardcoded recursion limit set to
++> 1000. In order to make this process work, you need to force the script to run
++> `bash` instead. You can do this by editing the first line of the `git-subtree`
++> script and changing `sh` to `bash`.
++
++## Defining remotes
++
++You may want to define remotes, so you don't have to type out the remote
++addresses on every sync. You can do this with the following commands (these
++commands still have to be run inside the `rust` directory):
++
++```bash
++# Set clippy-upstream remote for pulls
++$ git remote add clippy-upstream https://github.com/rust-lang/rust-clippy
++# Make sure to not push to the upstream repo
++$ git remote set-url --push clippy-upstream DISABLED
++# Set a local remote
++$ git remote add clippy-local /path/to/rust-clippy
++```
++
++> Note: The following sections assume that you have set those remotes with the
++> above remote names.
++
++## Performing the sync from [`rust-lang/rust`] to Clippy
++
++Here is a TL;DR version of the sync process (all of the following commands have
++to be run inside the `rust` directory):
++
++1. Clone the [`rust-lang/rust`] repository or make sure it is up to date.
++2. Checkout the commit from the latest available nightly. You can get it using
++ `rustup check`.
++3. Sync the changes to the rust-copy of Clippy to your Clippy fork:
++ ```bash
++ # Make sure to change `your-github-name` to your github name in the following command. Also be
++ # sure to either use a net-new branch, e.g. `sync-from-rust`, or delete the branch beforehand
++ # because changes cannot be fast forwarded and you have to run this command again.
++ git subtree push -P src/tools/clippy clippy-local sync-from-rust
++ ```
++
++ > _Note:_ Most of the time you have to create a merge commit in the
++ > `rust-clippy` repo (this has to be done in the Clippy repo, not in the
++ > rust-copy of Clippy):
++ ```bash
++ git fetch upstream # assuming upstream is the rust-lang/rust remote
++ git checkout sync-from-rust
++ git merge upstream/master --no-ff
++ ```
++ > Note: This is one of the few instances where a merge commit is allowed in
++ > a PR.
++4. Bump the nightly version in the Clippy repository by changing the date in the
++ rust-toolchain file to the current date and committing it with the message:
++ ```bash
++ git commit -m "Bump nightly version -> YYYY-MM-DD"
++ ```
++5. Open a PR to `rust-lang/rust-clippy` and wait for it to get merged (to
++ accelerate the process ping the `@rust-lang/clippy` team in your PR and/or
++ ask them in the [Zulip] stream.)
++
++[Zulip]: https://rust-lang.zulipchat.com/#narrow/stream/clippy
++
++## Performing the sync from Clippy to [`rust-lang/rust`]
++
++All of the following commands have to be run inside the `rust` directory.
++
++1. Make sure you have checked out the latest `master` of `rust-lang/rust`.
++2. Sync the `rust-lang/rust-clippy` master to the rust-copy of Clippy:
++ ```bash
++ git checkout -b sync-from-clippy
++ git subtree pull -P src/tools/clippy clippy-upstream master
++ ```
++3. Open a PR to [`rust-lang/rust`]
++
++[gitgitgadget-pr]: https://github.com/gitgitgadget/git/pull/493
++[subtree]: https://rustc-dev-guide.rust-lang.org/contributing.html#external-dependencies-subtree
++[`rust-lang/rust`]: https://github.com/rust-lang/rust
--- /dev/null
--- /dev/null
++# Proposals
++
++This chapter is about accepted proposals for changes that should be worked on in
++or around Clippy in the long run.
++
++Besides adding more and more lints and improve the lints that Clippy already
++has, Clippy is also interested in making the experience of its users, developers
++and maintainers better over time. Projects that address bigger picture things
++like this usually take more time and it is useful to have a proposal for those
++first. This is the place where such proposals are collected, so that we can
++refer to them when working on them.
--- /dev/null
--- /dev/null
++# Roadmap 2021
++
++# Summary
++
++This Roadmap lays out the plans for Clippy in 2021:
++
++- Improving usability and reliability
++- Improving experience of contributors and maintainers
++- Develop and specify processes
++
++Members of the Clippy team will be assigned tasks from one or more of these
++topics. The team member is then responsible to complete the assigned tasks. This
++can either be done by implementing them or by providing mentorship to interested
++contributors.
++
++# Motivation
++
++With the ongoing growth of the Rust language and with that of the whole
++ecosystem, also Clippy gets more and more users and contributors. This is good
++for the project, but also brings challenges along. Some of these challenges are:
++
++- More issues about reliability or usability are popping up
++- Traffic is hard to handle for a small team
++- Bigger projects don't get completed due to the lack of processes and/or time
++ of the team members
++
++Additionally, according to the [Rust Roadmap 2021], clear processes should be
++defined by every team and unified across teams. This Roadmap is the first step
++towards this.
++
++[Rust Roadmap 2021]: https://github.com/rust-lang/rfcs/pull/3037
++
++# Explanation
++
++This section will explain the things that should be done in 2021. It is
++important to note, that this document focuses on the "What?", not the "How?".
++The later will be addressed in follow-up tracking issue, with an assigned team
++member.
++
++The following is split up in two major sections. The first section covers the
++user facing plans, the second section the internal plans.
++
++## User Facing
++
++Clippy should be as pleasant to use and configure as possible. This section
++covers plans that should be implemented to improve the situation of Clippy in
++this regard.
++
++### Usability
++
++In the following, plans to improve the usability are covered.
++
++#### No Output After `cargo check`
++
++Currently when `cargo clippy` is run after `cargo check`, it does not produce
++any output. This is especially problematic since `rust-analyzer` is on the rise
++and it uses `cargo check` for checking code. A fix is already implemented, but
++it still has to be pushed over the finish line. This also includes the
++stabilization of the `cargo clippy --fix` command or the support of multi-span
++suggestions in `rustfix`.
++
++- [#4612](https://github.com/rust-lang/rust-clippy/issues/4612)
++
++#### `lints.toml` Configuration
++
++This is something that comes up every now and then: a reusable configuration
++file, where lint levels can be defined. Discussions about this often lead to
++nothing specific or to "we need an RFC for this". And this is exactly what needs
++to be done. Get together with the cargo team and write an RFC and implement such
++a configuration file somehow and somewhere.
++
++- [#3164](https://github.com/rust-lang/rust-clippy/issues/3164)
++- [cargo#5034](https://github.com/rust-lang/cargo/issues/5034)
++- [IRLO](https://internals.rust-lang.org/t/proposal-cargo-lint-configuration/9135/8)
++
++#### Lint Groups
++
++There are more and more issues about managing lints in Clippy popping up. Lints
++are hard to implement with a guarantee of no/few false positives (FPs). One way
++to address this might be to introduce more lint groups to give users the ability
++to better manage lints, or improve the process of classifying lints, so that
++disabling lints due to FPs becomes rare. It is important to note, that Clippy
++lints are less conservative than `rustc` lints, which won't change in the
++future.
++
++- [#5537](https://github.com/rust-lang/rust-clippy/issues/5537)
++- [#6366](https://github.com/rust-lang/rust-clippy/issues/6366)
++
++### Reliability
++
++In the following, plans to improve the reliability are covered.
++
++#### False Positive Rate
++
++In the worst case, new lints are only available in nightly for 2 weeks, before
++hitting beta and ultimately stable. This and the fact that fewer people use
++nightly Rust nowadays makes it more probable that a lint with many FPs hits
++stable. This leads to annoyed users, that will disable these new lints in the
++best case and to more annoyed users, that will stop using Clippy in the worst.
++A process should be developed and implemented to prevent this from happening.
++
++- [#6429](https://github.com/rust-lang/rust-clippy/issues/6429)
++
++## Internal
++
++(The end of) 2020 has shown, that Clippy has to think about the available
++resources, especially regarding management and maintenance of the project. This
++section address issues affecting team members and contributors.
++
++### Management
++
++In 2020 Clippy achieved over 1000 open issues with regularly between 25-35 open
++PRs. This is simultaneously a win and a loss. More issues and PRs means more
++people are interested in Clippy and in contributing to it. On the other hand, it
++means for team members more work and for contributors longer wait times for
++reviews. The following will describe plans how to improve the situation for both
++team members and contributors.
++
++#### Clear Expectations for Team Members
++
++According to the [Rust Roadmap 2021], a document specifying what it means to be
++a member of the team should be produced. This should not put more pressure on
++the team members, but rather help them and interested folks to know what the
++expectations are. With this it should also be easier to recruit new team members
++and may encourage people to get in touch, if they're interested to join.
++
++#### Scaling up the Team
++
++More people means less work for each individual. Together with the document
++about expectations for team members, a document defining the process of how to
++join the team should be produced. This can also increase the stability of the
++team, in case of current members dropping out (temporarily). There can also be
++different roles in the team, like people triaging vs. people reviewing.
++
++#### Regular Meetings
++
++Other teams have regular meetings. Clippy is big enough that it might be worth
++to also do them. Especially if more people join the team, this can be important
++for sync-ups. Besides the asynchronous communication, that works well for
++working on separate lints, a meeting adds a synchronous alternative at a known
++time. This is especially helpful if there are bigger things that need to be
++discussed (like the projects in this roadmap). For starters bi-weekly meetings
++before Rust syncs might make sense.
++
++#### Triaging
++
++To get a handle on the influx of open issues, a process for triaging issues and
++PRs should be developed. Officially, Clippy follows the Rust triage process, but
++currently no one enforces it. This can be improved by sharing triage teams
++across projects or by implementing dashboards / tools which simplify triaging.
++
++### Development
++
++Improving the developer and contributor experience is something the Clippy team
++works on regularly. Though, some things might need special attention and
++planing. These topics are listed in the following.
++
++#### Process for New and Existing Lints
++
++As already mentioned above, classifying new lints gets quite hard, because the
++probability of a buggy lint getting into stable is quite high. A process should
++be implemented on how to classify lints. In addition, a test system should be
++developed to find out which lints are currently problematic in real world code
++to fix or disable them.
++
++- [#6429 (comment)](https://github.com/rust-lang/rust-clippy/issues/6429#issuecomment-741056379)
++- [#6429 (comment)](https://github.com/rust-lang/rust-clippy/issues/6429#issuecomment-741153345)
++
++#### Processes
++
++Related to the point before, a process for suggesting and discussing major
++changes should be implemented. It's also not clearly defined when a lint should
++be enabled or disabled by default. This can also be improved by the test system
++mentioned above.
++
++#### Dev-Tools
++
++There's already `cargo dev` which makes Clippy development easier and more
++pleasant. This can still be expanded, so that it covers more areas of the
++development process.
++
++- [#5394](https://github.com/rust-lang/rust-clippy/issues/5394)
++
++#### Contributor Guide
++
++Similar to a Clippy Book, which describes how to use Clippy, a book about how to
++contribute to Clippy might be helpful for new and existing contributors. There's
++already the `doc` directory in the Clippy repo, this can be turned into a
++`mdbook`.
++
++#### `rustc` integration
++
++Recently Clippy was integrated with `git subtree` into the `rust-lang/rust`
++repository. This made syncing between the two repositories easier. A
++`#[non_exhaustive]` list of things that still can be improved is:
++
++1. Use the same `rustfmt` version and configuration as `rustc`.
++2. Make `cargo dev` work in the Rust repo, just as it works in the Clippy repo.
++ E.g. `cargo dev bless` or `cargo dev update_lints`. And even add more things
++ to it that might be useful for the Rust repo, e.g. `cargo dev deprecate`.
++3. Easier sync process. The `subtree` situation is not ideal.
++
++## Prioritization
++
++The most pressing issues for users of Clippy are of course the user facing
++issues. So there should be a priority on those issues, but without losing track
++of the internal issues listed in this document.
++
++Getting the FP rate of warn/deny-by-default lints under control should have the
++highest priority. Other user facing issues should also get a high priority, but
++shouldn't be in the way of addressing internal issues.
++
++To better manage the upcoming projects, the basic internal processes, like
++meetings, tracking issues and documentation, should be established as soon as
++possible. They might even be necessary to properly manage the projects,
++regarding the user facing issues.
++
++# Prior Art
++
++## Rust Roadmap
++
++Rust's roadmap process was established by [RFC 1728] in 2016. Since then every
++year a roadmap was published, that defined the bigger plans for the coming
++years. This years roadmap can be found [here][Rust Roadmap 2021].
++
++[RFC 1728]: https://rust-lang.github.io/rfcs/1728-north-star.html
++
++# Drawbacks
++
++## Big Roadmap
++
++This roadmap is pretty big and not all items listed in this document might be
++addressed during 2021. Because this is the first roadmap for Clippy, having open
++tasks at the end of 2021 is fine, but they should be revisited in the 2022
++roadmap.
--- /dev/null
--- /dev/null
++# Installation
++
++If you're using `rustup` to install and manage you're Rust toolchains, Clippy is
++usually **already installed**. In that case you can skip this chapter and go to
++the [Usage] chapter.
++
++> Note: If you used the `minimal` profile when installing a Rust toolchain,
++> Clippy is not automatically installed.
++
++## Using Rustup
++
++If Clippy was not installed for a toolchain, it can be installed with
++
++```
++$ rustup component add clippy [--toolchain=<name>]
++```
++
++## From Source
++
++Take a look at the [Basics] chapter in the Clippy developer guide to find step
++by step instructions on how to build and install Clippy from source.
++
++[Basics]: development/basics.md#install-from-source
++[Usage]: usage.md
--- /dev/null
--- /dev/null
++# Clippy's Lints
++
++Clippy offers a bunch of additional lints, to help its users write more correct
++and idiomatic Rust code. A full list of all lints, that can be filtered by
++category, lint level or keywords, can be found in the [Clippy lint
++documentation].
++
++This chapter will give an overview of the different lint categories, which kind
++of lints they offer and recommended actions when you should see a lint out of
++that category. For examples, see the [Clippy lint documentation] and filter by
++category.
++
++The different lint groups were defined in the [Clippy 1.0 RFC].
++
++## Correctness
++
++The `clippy::correctness` group is the only lint group in Clippy which lints are
++deny-by-default and abort the compilation when triggered. This is for good
++reason: If you see a `correctness` lint, it means that your code is outright
++wrong or useless and you should try to fix it.
++
++Lints in this category are carefully picked and should be free of false
++positives. So just `#[allow]`ing those lints is not recommended.
++
++## Suspicious
++
++The `clippy::suspicious` group is similar to the correctness lints in that it
++contains lints that trigger on code that is really _sus_ and should be fixed. As
++opposed to correctness lints, it might be possible that the linted code is
++intentionally written like it is.
++
++It is still recommended to fix code that is linted by lints out of this group
++instead of `#[allow]`ing the lint. In case you intentionally have written code
++that offends the lint you should specifically and locally `#[allow]` the lint
++and add give a reason why the code is correct as written.
++
++## Complexity
++
++The `clippy::complexity` group offers lints that give you suggestions on how to
++simplify your code. It mostly focuses on code that can be written in a shorter
++and more readable way, while preserving the semantics.
++
++If you should see a complexity lint, it usually means that you can remove or
++replace some code and it is recommended to do so. However, if you need the more
++complex code for some expressiveness reason, it is recommended to allow
++complexity lints on a case-by-case basis.
++
++## Perf
++
++The `clippy::perf` group gives you suggestions on how you can increase the
++performance of your code. Those lints are mostly about code that the compiler
++can't trivially optimize, but has to be written in a slightly different way to
++make the optimizer's job easier.
++
++Perf lints are usually easy to apply and it is recommended to do so.
++
++## Style
++
++The `clippy::style` group is mostly about writing idiomatic code. Because style
++is subjective, this lint group is the most opinionated warn-by-default group in
++Clippy.
++
++If you see a style lint, applying the suggestion usually makes your code more
++readable and idiomatic. But because we know that this is opinionated, feel free
++to sprinkle `#[allow]`s for style lints in your code or `#![allow]` a style lint
++on your whole crate if you disagree with the suggested style completely.
++
++## Pedantic
++
++The `clippy::pedantic` group makes Clippy even more _pedantic_. You can enable
++the whole group with `#![warn(clippy::pedantic)]` in the `lib.rs`/`main.rs` of
++your crate. This lint group is for Clippy power users that want an in depth
++check of their code.
++
++> _Note:_ Instead of enabling the whole group (like Clippy itself does), you may
++> want to cherry-pick lints out of the pedantic group.
++
++If you enable this group, expect to also use `#[allow]` attributes generously
++throughout your code. Lints in this group are designed to be pedantic and false
++positives sometimes are intentional in order to prevent false negatives.
++
++## Restriction
++
++The `clippy::restriction` group contains lints that will _restrict_ you from
++using certain parts of the Rust language. It is **not** recommended to enable
++the whole group, but rather cherry-pick lints that are useful for your code base
++and your use case.
++
++> _Note:_ Clippy will produce a warning if it finds a
++> `#![warn(clippy::restriction)]` attribute in your code!
++
++Lints from this group will restrict you in some way. If you enable a restriction
++lint for your crate it is recommended to also fix code that this lint triggers
++on. However, those lints are really strict by design and you might want to
++`#[allow]` them in some special cases, with a comment justifying that.
++
++## Cargo
++
++The `clippy::cargo` group gives you suggestions on how to improve your
++`Cargo.toml` file. This might be especially interesting if you want to publish
++your crate and are not sure if you have all useful information in your
++`Cargo.toml`.
++
++[Clippy lint documentation]: https://rust-lang.github.io/rust-clippy/
++[Clippy 1.0 RFC]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#lint-audit-and-categories
--- /dev/null
--- /dev/null
++# Usage
++
++This chapter describes how to use Clippy to get the most out of it. Clippy can
++be used as a `cargo` subcommand or, like `rustc`, directly with the
++`clippy-driver` binary.
++
++> _Note:_ This chapter assumes that you have Clippy installed already. If you're
++> not sure, take a look at the [Installation] chapter.
++
++## Cargo subcommand
++
++The easiest and most common way to run Clippy is through `cargo`. To do that,
++just run
++
++```bash
++cargo clippy
++```
++
++### Lint configuration
++
++The above command will run the default set of lints, which are included in the
++lint group `clippy::all`. You might want to use even more lints or you might not
++agree with every Clippy lint, and for that there are ways to configure lint
++levels.
++
++> _Note:_ Clippy is meant to be used with a generous sprinkling of
++> `#[allow(..)]`s through your code. So if you disagree with a lint, don't feel
++> bad disabling them for parts of your code or the whole project.
++
++#### Command line
++
++You can configure lint levels on the command line by adding
++`-A/W/D clippy::lint_name` like this:
++
++```bash
++cargo clippy -- -Aclippy::style -Wclippy::double_neg -Dclippy::perf
++```
++
++For [CI] all warnings can be elevated to errors which will inturn fail
++the build and cause Clippy to exit with a code other than `0`.
++
++```
++cargo clippy -- -Dwarnings
++```
++
++> _Note:_ Adding `-D warnings` will cause your build to fail if **any** warnings
++> are found in your code. That includes warnings found by rustc (e.g.
++> `dead_code`, etc.).
++
++For more information on configuring lint levels, see the [rustc documentation].
++
++[rustc documentation]: https://doc.rust-lang.org/rustc/lints/levels.html#configuring-warning-levels
++
++#### Even more lints
++
++Clippy has lint groups which are allow-by-default. This means, that you will
++have to enable the lints in those groups manually.
++
++For a full list of all lints with their description and examples, please refere
++to [Clippy's lint list]. The two most important allow-by-default groups are
++described below:
++
++[Clippy's lint list]: https://rust-lang.github.io/rust-clippy/master/index.html
++
++##### `clippy::pedantic`
++
++The first group is the `pedantic` group. This group contains really opinionated
++lints, that may have some intentional false positives in order to prevent false
++negatives. So while this group is ready to be used in production, you can expect
++to sprinkle multiple `#[allow(..)]`s in your code. If you find any false
++positives, you're still welcome to report them to us for future improvements.
++
++> FYI: Clippy uses the whole group to lint itself.
++
++##### `clippy::restriction`
++
++The second group is the `restriction` group. This group contains lints that
++"restrict" the language in some way. For example the `clippy::unwrap` lint from
++this group won't allow you to use `.unwrap()` in your code. You may want to look
++through the lints in this group and enable the ones that fit your need.
++
++> _Note:_ You shouldn't enable the whole lint group, but cherry-pick lints from
++> this group. Some lints in this group will even contradict other Clippy lints!
++
++#### Too many lints
++
++The most opinionated warn-by-default group of Clippy is the `clippy::style`
++group. Some people prefer to disable this group completely and then cherry-pick
++some lints they like from this group. The same is of course possible with every
++other of Clippy's lint groups.
++
++> _Note:_ We try to keep the warn-by-default groups free from false positives
++> (FP). If you find that a lint wrongly triggers, please report it in an issue
++> (if there isn't an issue for that FP already)
++
++#### Source Code
++
++You can configure lint levels in source code the same way you can configure
++`rustc` lints:
++
++```rust
++#![allow(clippy::style)]
++
++#[warn(clippy::double_neg)]
++fn main() {
++ let x = 1;
++ let y = --x;
++ // ^^ warning: double negation
++}
++```
++
++### Automatically applying Clippy suggestions
++
++Clippy can automatically apply some lint suggestions, just like the compiler.
++
++```terminal
++cargo clippy --fix
++```
++
++### Workspaces
++
++All the usual workspace options should work with Clippy. For example the
++following command will run Clippy on the `example` crate in your workspace:
++
++```terminal
++cargo clippy -p example
++```
++
++As with `cargo check`, this includes dependencies that are members of the
++workspace, like path dependencies. If you want to run Clippy **only** on the
++given crate, use the `--no-deps` option like this:
++
++```terminal
++cargo clippy -p example -- --no-deps
++```
++
++## Using Clippy without `cargo`: `clippy-driver`
++
++Clippy can also be used in projects that do not use cargo. To do so, run
++`clippy-driver` with the same arguments you use for `rustc`. For example:
++
++```terminal
++clippy-driver --edition 2018 -Cpanic=abort foo.rs
++```
++
++> _Note:_ `clippy-driver` is designed for running Clippy and should not be used
++> as a general replacement for `rustc`. `clippy-driver` may produce artifacts
++> that are not optimized as expected, for example.
++
++[Installation]: installation.md
++[CI]: continuous_integration
--- /dev/null
- pub fn run<'a>(path: &str, args: impl Iterator<Item = &'a str>) {
+use crate::cargo_clippy_path;
+use std::process::{self, Command, ExitStatus};
+use std::{fs, io};
+
+fn exit_if_err(status: io::Result<ExitStatus>) {
+ match status.expect("failed to run command").code() {
+ Some(0) => {},
+ Some(n) => process::exit(n),
+ None => {
+ eprintln!("Killed by signal");
+ process::exit(1);
+ },
+ }
+}
+
++pub fn run<'a>(path: &str, args: impl Iterator<Item = &'a String>) {
+ let is_file = match fs::metadata(path) {
+ Ok(metadata) => metadata.is_file(),
+ Err(e) => {
+ eprintln!("Failed to read {path}: {e:?}");
+ process::exit(1);
+ },
+ };
+
+ if is_file {
+ exit_if_err(
+ Command::new("cargo")
+ .args(["run", "--bin", "clippy-driver", "--"])
+ .args(["-L", "./target/debug"])
+ .args(["-Z", "no-codegen"])
+ .args(["--edition", "2021"])
+ .arg(path)
+ .args(args)
+ .status(),
+ );
+ } else {
+ exit_if_err(Command::new("cargo").arg("build").status());
+
+ // Run in a tempdir as changes to clippy do not retrigger linting
+ let target = tempfile::Builder::new()
+ .prefix("clippy")
+ .tempdir()
+ .expect("failed to create tempdir");
+
+ let status = Command::new(cargo_clippy_path())
+ .arg("clippy")
+ .args(args)
+ .current_dir(path)
+ .env("CARGO_TARGET_DIR", target.as_ref())
+ .status();
+
+ target.close().expect("failed to remove tempdir");
+ exit_if_err(status);
+ }
+}
--- /dev/null
- use clap::{Arg, ArgMatches, Command};
+#![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::bless(matches.is_present("ignore-timestamp"));
++use clap::{Arg, ArgAction, ArgMatches, Command, PossibleValue};
+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() {
+ Some(("bless", matches)) => {
- fmt::run(matches.is_present("check"), matches.is_present("verbose"));
++ bless::bless(matches.contains_id("ignore-timestamp"));
+ },
+ Some(("fmt", matches)) => {
- if matches.is_present("print-only") {
++ fmt::run(matches.contains_id("check"), matches.contains_id("verbose"));
+ },
+ Some(("update_lints", matches)) => {
- } else if matches.is_present("check") {
++ if matches.contains_id("print-only") {
+ update_lints::print_lints();
- matches.value_of("pass"),
- matches.value_of("name"),
- matches.value_of("category"),
- matches.is_present("msrv"),
++ } else if matches.contains_id("check") {
+ update_lints::update(update_lints::UpdateMode::Check);
+ } else {
+ update_lints::update(update_lints::UpdateMode::Change);
+ }
+ },
+ Some(("new_lint", matches)) => {
+ match new_lint::create(
- if matches.is_present("remove") {
++ matches.get_one::<String>("pass"),
++ matches.get_one::<String>("name"),
++ matches.get_one::<String>("category"),
++ matches.contains_id("msrv"),
+ ) {
+ Ok(_) => update_lints::update(update_lints::UpdateMode::Change),
+ Err(e) => eprintln!("Unable to create lint: {}", e),
+ }
+ },
+ Some(("setup", sub_command)) => match sub_command.subcommand() {
+ Some(("intellij", matches)) => {
- .value_of("rustc-repo-path")
++ if matches.contains_id("remove") {
+ setup::intellij::remove_rustc_src();
+ } else {
+ setup::intellij::setup_rustc_src(
+ matches
- if matches.is_present("remove") {
++ .get_one::<String>("rustc-repo-path")
+ .expect("this field is mandatory and therefore always valid"),
+ );
+ }
+ },
+ Some(("git-hook", matches)) => {
- setup::git_hook::install_hook(matches.is_present("force-override"));
++ if matches.contains_id("remove") {
+ setup::git_hook::remove_hook();
+ } else {
- if matches.is_present("remove") {
++ setup::git_hook::install_hook(matches.contains_id("force-override"));
+ }
+ },
+ Some(("vscode-tasks", matches)) => {
- setup::vscode::install_tasks(matches.is_present("force-override"));
++ if matches.contains_id("remove") {
+ setup::vscode::remove_tasks();
+ } else {
- let port = matches.value_of("port").unwrap().parse().unwrap();
- let lint = matches.value_of("lint");
++ setup::vscode::install_tasks(matches.contains_id("force-override"));
+ }
+ },
+ _ => {},
+ },
+ 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(),
+ _ => {},
+ },
+ Some(("serve", matches)) => {
- let path = matches.value_of("path").unwrap();
- let args = matches.values_of("args").into_iter().flatten();
++ let port = *matches.get_one::<u16>("port").unwrap();
++ let lint = matches.get_one::<String>("lint");
+ serve::run(port, lint);
+ },
+ Some(("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");
++ let path = matches.get_one::<String>("path").unwrap();
++ let args = matches.get_many::<String>("args").into_iter().flatten();
+ lint::run(path, args);
+ },
+ Some(("rename_lint", matches)) => {
- .subcommand(
++ let old_name = matches.get_one::<String>("old_name").unwrap();
++ let new_name = matches.get_one::<String>("new_name").unwrap_or(old_name);
++ let uplift = matches.contains_id("uplift");
+ update_lints::rename(old_name, new_name, uplift);
+ },
+ _ => {},
+ }
+}
+
+fn get_clap_config() -> ArgMatches {
+ Command::new("Clippy developer tooling")
+ .arg_required_else_help(true)
- )
- .subcommand(
++ .subcommands([
+ 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"),
+ ),
- .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(
+ Command::new("fmt")
+ .about("Run rustfmt on all projects and tests")
- * 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",
++ .args([
++ Arg::new("check").long("check").help("Use the rustfmt --check option"),
++ Arg::new("verbose").short('v').long("verbose").help("Echo commands run"),
++ ]),
+ Command::new("update_lints")
+ .about("Updates lint registration and information from the source code")
+ .long_about(
+ "Makes sure that:\n \
- .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(
++ * 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",
+ )
- ),
- )
- .subcommand(
++ .args([
++ 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::new("check")
+ .long("check")
+ .help("Checks that `cargo dev update_lints` has been run. Used on CI."),
- .arg(
++ ]),
+ Command::new("new_lint")
+ .about("Create new lint and run `cargo dev update_lints`")
- .possible_values(&["early", "late"])
++ .args([
+ Arg::new("pass")
+ .short('p')
+ .long("pass")
+ .help("Specify whether the lint runs during the early or late pass")
+ .takes_value(true)
- )
- .arg(
++ .value_parser([PossibleValue::new("early"), PossibleValue::new("late")])
+ .required(true),
- )
- .arg(
+ 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),
- .possible_values(&[
- "style",
- "correctness",
- "suspicious",
- "complexity",
- "perf",
- "pedantic",
- "restriction",
- "cargo",
- "nursery",
- "internal",
- "internal_warn",
+ Arg::new("category")
+ .short('c')
+ .long("category")
+ .help("What category the lint belongs to")
+ .default_value("nursery")
- )
- .arg(Arg::new("msrv").long("msrv").help("Add MSRV config code to the lint")),
- )
- .subcommand(
++ .value_parser([
++ PossibleValue::new("style"),
++ PossibleValue::new("correctness"),
++ PossibleValue::new("suspicious"),
++ PossibleValue::new("complexity"),
++ PossibleValue::new("perf"),
++ PossibleValue::new("pedantic"),
++ PossibleValue::new("restriction"),
++ PossibleValue::new("cargo"),
++ PossibleValue::new("nursery"),
++ PossibleValue::new("internal"),
++ PossibleValue::new("internal_warn"),
+ ])
+ .takes_value(true),
- .subcommand(
++ Arg::new("msrv").long("msrv").help("Add MSRV config code to the lint"),
++ ]),
+ Command::new("setup")
+ .about("Support for setting up your personal development environment")
+ .arg_required_else_help(true)
- .arg(
++ .subcommands([
+ Command::new("intellij")
+ .about("Alter dependencies so Intellij Rust can find rustc internals")
- )
- .arg(
++ .args([
+ Arg::new("remove")
+ .long("remove")
+ .help("Remove the dependencies added with 'cargo dev setup intellij'")
+ .required(false),
- ),
- )
- .subcommand(
+ Arg::new("rustc-repo-path")
+ .long("repo-path")
+ .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),
- .arg(
++ ]),
+ Command::new("git-hook")
+ .about("Add a pre-commit git hook that formats your code to make it look pretty")
- )
- .arg(
++ .args([
+ Arg::new("remove")
+ .long("remove")
+ .help("Remove the pre-commit hook added with 'cargo dev setup git-hook'")
+ .required(false),
- ),
- )
- .subcommand(
+ Arg::new("force-override")
+ .long("force-override")
+ .short('f')
+ .help("Forces the override of an existing git pre-commit hook")
+ .required(false),
- .arg(
++ ]),
+ Command::new("vscode-tasks")
+ .about("Add several tasks to vscode for formatting, validation and testing")
- )
- .arg(
++ .args([
+ Arg::new("remove")
+ .long("remove")
+ .help("Remove the tasks added with 'cargo dev setup vscode-tasks'")
+ .required(false),
- ),
- ),
- )
- .subcommand(
+ Arg::new("force-override")
+ .long("force-override")
+ .short('f')
+ .help("Forces the override of existing vscode tasks")
+ .required(false),
- .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(
++ ]),
++ ]),
+ Command::new("remove")
+ .about("Support for undoing changes done by the setup command")
+ .arg_required_else_help(true)
- ),
- )
- .subcommand(
++ .subcommands([
++ Command::new("git-hook").about("Remove any existing pre-commit git hook"),
++ Command::new("vscode-tasks").about("Remove any existing vscode tasks"),
+ Command::new("intellij").about("Removes rustc source paths added via `cargo dev setup intellij`"),
- .arg(
++ ]),
+ Command::new("serve")
+ .about("Launch a local 'ALL the Clippy Lints' website in a browser")
- .validator_os(serve::validate_port),
- )
- .arg(Arg::new("lint").help("Which lint's page to load initially (optional)")),
- )
- .subcommand(
++ .args([
+ Arg::new("port")
+ .long("port")
+ .short('p')
+ .help("Local port for the http server")
+ .default_value("8000")
- .arg(
++ .value_parser(clap::value_parser!(u16)),
++ Arg::new("lint").help("Which lint's page to load initially (optional)"),
++ ]),
+ 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(
++ .args([
+ Arg::new("path")
+ .required(true)
+ .help("The path to a file or package directory to lint"),
- .multiple_occurrences(true)
+ Arg::new("args")
- ),
- )
- .subcommand(
- Command::new("rename_lint")
- .about("Renames the given lint")
- .arg(
- Arg::new("old_name")
- .index(1)
- .required(true)
- .help("The name of the lint to rename"),
- )
- .arg(
- Arg::new("new_name")
- .index(2)
- .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"),
- ),
- )
++ .action(ArgAction::Append)
+ .help("Pass extra arguments to cargo/clippy-driver"),
++ ]),
++ Command::new("rename_lint").about("Renames the given lint").args([
++ Arg::new("old_name")
++ .index(1)
++ .required(true)
++ .help("The name of the lint to rename"),
++ Arg::new("new_name")
++ .index(2)
++ .required_unless_present("uplift")
++ .help("The new name of the lint"),
++ Arg::new("uplift")
++ .long("uplift")
++ .help("This lint will be uplifted into rustc"),
++ ]),
++ ])
+ .get_matches()
+}
--- /dev/null
- pub fn create(pass: Option<&str>, lint_name: Option<&str>, category: Option<&str>, msrv: bool) -> io::Result<()> {
+use crate::clippy_project_root;
+use indoc::indoc;
+use std::fmt::Write as _;
+use std::fs::{self, OpenOptions};
+use std::io::prelude::*;
+use std::io::{self, ErrorKind};
+use std::path::{Path, PathBuf};
+
+struct LintData<'a> {
+ pass: &'a str,
+ name: &'a str,
+ category: &'a str,
+ project_root: PathBuf,
+}
+
+trait Context {
+ fn context<C: AsRef<str>>(self, text: C) -> Self;
+}
+
+impl<T> Context for io::Result<T> {
+ fn context<C: AsRef<str>>(self, text: C) -> Self {
+ match self {
+ Ok(t) => Ok(t),
+ Err(e) => {
+ let message = format!("{}: {}", text.as_ref(), e);
+ Err(io::Error::new(ErrorKind::Other, message))
+ },
+ }
+ }
+}
+
+/// Creates the files required to implement and test a new lint and runs `update_lints`.
+///
+/// # Errors
+///
+/// This function errors out if the files couldn't be created or written to.
++pub fn create(
++ pass: Option<&String>,
++ lint_name: Option<&String>,
++ category: Option<&String>,
++ msrv: bool,
++) -> io::Result<()> {
+ let lint = LintData {
+ pass: pass.expect("`pass` argument is validated by clap"),
+ name: lint_name.expect("`name` argument is validated by clap"),
+ category: category.expect("`category` argument is validated by clap"),
+ project_root: clippy_project_root(),
+ };
+
+ create_lint(&lint, msrv).context("Unable to create lint implementation")?;
+ create_test(&lint).context("Unable to create a test for the new lint")?;
+ add_lint(&lint, msrv).context("Unable to add lint to clippy_lints/src/lib.rs")
+}
+
+fn create_lint(lint: &LintData<'_>, enable_msrv: bool) -> io::Result<()> {
+ let lint_contents = get_lint_file_contents(lint, enable_msrv);
+
+ let lint_path = format!("clippy_lints/src/{}.rs", lint.name);
+ write_file(lint.project_root.join(&lint_path), lint_contents.as_bytes())
+}
+
+fn create_test(lint: &LintData<'_>) -> io::Result<()> {
+ fn create_project_layout<P: Into<PathBuf>>(lint_name: &str, location: P, case: &str, hint: &str) -> io::Result<()> {
+ let mut path = location.into().join(case);
+ fs::create_dir(&path)?;
+ write_file(path.join("Cargo.toml"), get_manifest_contents(lint_name, hint))?;
+
+ path.push("src");
+ fs::create_dir(&path)?;
+ let header = format!("// compile-flags: --crate-name={}", lint_name);
+ write_file(path.join("main.rs"), get_test_file_contents(lint_name, Some(&header)))?;
+
+ Ok(())
+ }
+
+ if lint.category == "cargo" {
+ let relative_test_dir = format!("tests/ui-cargo/{}", lint.name);
+ let test_dir = lint.project_root.join(relative_test_dir);
+ fs::create_dir(&test_dir)?;
+
+ create_project_layout(lint.name, &test_dir, "fail", "Content that triggers the lint goes here")?;
+ create_project_layout(lint.name, &test_dir, "pass", "This file should not trigger the lint")
+ } else {
+ let test_path = format!("tests/ui/{}.rs", lint.name);
+ let test_contents = get_test_file_contents(lint.name, None);
+ write_file(lint.project_root.join(test_path), test_contents)
+ }
+}
+
+fn add_lint(lint: &LintData<'_>, enable_msrv: bool) -> io::Result<()> {
+ let path = "clippy_lints/src/lib.rs";
+ let mut lib_rs = fs::read_to_string(path).context("reading")?;
+
+ let comment_start = lib_rs.find("// add lints here,").expect("Couldn't find comment");
+
+ let new_lint = if enable_msrv {
+ format!(
+ "store.register_{lint_pass}_pass(move || Box::new({module_name}::{camel_name}::new(msrv)));\n ",
+ lint_pass = lint.pass,
+ module_name = lint.name,
+ camel_name = to_camel_case(lint.name),
+ )
+ } else {
+ format!(
+ "store.register_{lint_pass}_pass(|| Box::new({module_name}::{camel_name}));\n ",
+ lint_pass = lint.pass,
+ module_name = lint.name,
+ camel_name = to_camel_case(lint.name),
+ )
+ };
+
+ lib_rs.insert_str(comment_start, &new_lint);
+
+ fs::write(path, lib_rs).context("writing")
+}
+
+fn write_file<P: AsRef<Path>, C: AsRef<[u8]>>(path: P, contents: C) -> io::Result<()> {
+ fn inner(path: &Path, contents: &[u8]) -> io::Result<()> {
+ OpenOptions::new()
+ .write(true)
+ .create_new(true)
+ .open(path)?
+ .write_all(contents)
+ }
+
+ inner(path.as_ref(), contents.as_ref()).context(format!("writing to file: {}", path.as_ref().display()))
+}
+
+fn to_camel_case(name: &str) -> String {
+ name.split('_')
+ .map(|s| {
+ if s.is_empty() {
+ String::from("")
+ } else {
+ [&s[0..1].to_uppercase(), &s[1..]].concat()
+ }
+ })
+ .collect()
+}
+
+fn get_stabilization_version() -> String {
+ fn parse_manifest(contents: &str) -> Option<String> {
+ let version = contents
+ .lines()
+ .filter_map(|l| l.split_once('='))
+ .find_map(|(k, v)| (k.trim() == "version").then(|| v.trim()))?;
+ let Some(("0", version)) = version.get(1..version.len() - 1)?.split_once('.') else {
+ return None;
+ };
+ let (minor, patch) = version.split_once('.')?;
+ Some(format!(
+ "{}.{}.0",
+ minor.parse::<u32>().ok()?,
+ patch.parse::<u32>().ok()?
+ ))
+ }
+ let contents = fs::read_to_string("Cargo.toml").expect("Unable to read `Cargo.toml`");
+ parse_manifest(&contents).expect("Unable to find package version in `Cargo.toml`")
+}
+
+fn get_test_file_contents(lint_name: &str, header_commands: Option<&str>) -> String {
+ let mut contents = format!(
+ indoc! {"
+ #![warn(clippy::{})]
+
+ fn main() {{
+ // test code goes here
+ }}
+ "},
+ lint_name
+ );
+
+ if let Some(header) = header_commands {
+ contents = format!("{}\n{}", header, contents);
+ }
+
+ contents
+}
+
+fn get_manifest_contents(lint_name: &str, hint: &str) -> String {
+ format!(
+ indoc! {r#"
+ # {}
+
+ [package]
+ name = "{}"
+ version = "0.1.0"
+ publish = false
+
+ [workspace]
+ "#},
+ hint, lint_name
+ )
+}
+
+fn get_lint_file_contents(lint: &LintData<'_>, enable_msrv: bool) -> String {
+ let mut result = String::new();
+
+ let (pass_type, pass_lifetimes, pass_import, context_import) = match lint.pass {
+ "early" => ("EarlyLintPass", "", "use rustc_ast::ast::*;", "EarlyContext"),
+ "late" => ("LateLintPass", "<'_>", "use rustc_hir::*;", "LateContext"),
+ _ => {
+ unreachable!("`pass_type` should only ever be `early` or `late`!");
+ },
+ };
+
+ let version = get_stabilization_version();
+ let lint_name = lint.name;
+ let category = lint.category;
+ let name_camel = to_camel_case(lint.name);
+ let name_upper = lint_name.to_uppercase();
+
+ result.push_str(&if enable_msrv {
+ format!(
+ indoc! {"
+ use clippy_utils::msrvs;
+ {pass_import}
+ use rustc_lint::{{{context_import}, {pass_type}, LintContext}};
+ use rustc_semver::RustcVersion;
+ use rustc_session::{{declare_tool_lint, impl_lint_pass}};
+
+ "},
+ pass_type = pass_type,
+ pass_import = pass_import,
+ context_import = context_import,
+ )
+ } else {
+ format!(
+ indoc! {"
+ {pass_import}
+ use rustc_lint::{{{context_import}, {pass_type}}};
+ use rustc_session::{{declare_lint_pass, declare_tool_lint}};
+
+ "},
+ pass_import = pass_import,
+ pass_type = pass_type,
+ context_import = context_import
+ )
+ });
+
+ let _ = write!(
+ result,
+ indoc! {r#"
+ declare_clippy_lint! {{
+ /// ### What it does
+ ///
+ /// ### Why is this bad?
+ ///
+ /// ### Example
+ /// ```rust
+ /// // example code where clippy issues a warning
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// // example code which does not raise clippy warning
+ /// ```
+ #[clippy::version = "{version}"]
+ pub {name_upper},
+ {category},
+ "default lint description"
+ }}
+ "#},
+ version = version,
+ name_upper = name_upper,
+ category = category,
+ );
+
+ result.push_str(&if enable_msrv {
+ format!(
+ indoc! {"
+ pub struct {name_camel} {{
+ msrv: Option<RustcVersion>,
+ }}
+
+ impl {name_camel} {{
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {{
+ Self {{ msrv }}
+ }}
+ }}
+
+ impl_lint_pass!({name_camel} => [{name_upper}]);
+
+ impl {pass_type}{pass_lifetimes} for {name_camel} {{
+ extract_msrv_attr!({context_import});
+ }}
+
+ // TODO: Add MSRV level to `clippy_utils/src/msrvs.rs` if needed.
+ // TODO: Add MSRV test to `tests/ui/min_rust_version_attr.rs`.
+ // TODO: Update msrv config comment in `clippy_lints/src/utils/conf.rs`
+ "},
+ pass_type = pass_type,
+ pass_lifetimes = pass_lifetimes,
+ name_upper = name_upper,
+ name_camel = name_camel,
+ context_import = context_import,
+ )
+ } else {
+ format!(
+ indoc! {"
+ declare_lint_pass!({name_camel} => [{name_upper}]);
+
+ impl {pass_type}{pass_lifetimes} for {name_camel} {{}}
+ "},
+ pass_type = pass_type,
+ pass_lifetimes = pass_lifetimes,
+ name_upper = name_upper,
+ name_camel = name_camel,
+ )
+ });
+
+ result
+}
+
+#[test]
+fn test_camel_case() {
+ let s = "a_lint";
+ let s2 = to_camel_case(s);
+ assert_eq!(s2, "ALint");
+
+ let name = "a_really_long_new_lint";
+ let name2 = to_camel_case(name);
+ assert_eq!(name2, "AReallyLongNewLint");
+
+ let name3 = "lint__name";
+ let name4 = to_camel_case(name3);
+ assert_eq!(name4, "LintName");
+}
--- /dev/null
- pub fn run(port: u16, lint: Option<&str>) -> ! {
+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<&String>) -> ! {
+ 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<(), ParseIntError> {
+ arg.to_string_lossy().parse::<u16>().map(|_| ())
+}
--- /dev/null
+use aho_corasick::AhoCorasickBuilder;
+use core::fmt::Write as _;
+use itertools::Itertools;
+use rustc_lexer::{tokenize, unescape, LiteralKind, TokenKind};
+use std::collections::{HashMap, HashSet};
+use std::ffi::OsStr;
+use std::fs;
+use std::io::{self, Read as _, Seek as _, Write as _};
+use std::path::{Path, PathBuf};
+use walkdir::{DirEntry, WalkDir};
+
+use crate::clippy_project_root;
+
+const GENERATED_FILE_COMMENT: &str = "// This file was generated by `cargo dev update_lints`.\n\
+ // Use that command to update this file and do not edit by hand.\n\
+ // Manual edits will be overwritten.\n\n";
+
+const DOCS_LINK: &str = "https://rust-lang.github.io/rust-clippy/master/index.html";
+
+#[derive(Clone, Copy, PartialEq, Eq)]
+pub enum UpdateMode {
+ Check,
+ Change,
+}
+
+/// Runs the `update_lints` command.
+///
+/// This updates various generated values from the lint source code.
+///
+/// `update_mode` indicates if the files should be updated or if updates should be checked for.
+///
+/// # Panics
+///
+/// Panics if a file path could not read from or then written to
+pub fn update(update_mode: UpdateMode) {
+ let (lints, deprecated_lints, renamed_lints) = gather_all();
+ generate_lint_files(update_mode, &lints, &deprecated_lints, &renamed_lints);
+}
+
+fn generate_lint_files(
+ update_mode: UpdateMode,
+ lints: &[Lint],
+ deprecated_lints: &[DeprecatedLint],
+ renamed_lints: &[RenamedLint],
+) {
+ let internal_lints = Lint::internal_lints(lints);
+ let usable_lints = Lint::usable_lints(lints);
+ let mut sorted_usable_lints = usable_lints.clone();
+ sorted_usable_lints.sort_by_key(|lint| lint.name.clone());
+
+ replace_region_in_file(
+ update_mode,
+ Path::new("README.md"),
+ "[There are over ",
+ " lints included in this crate!]",
+ |res| {
+ write!(res, "{}", round_to_fifty(usable_lints.len())).unwrap();
+ },
+ );
+
++ replace_region_in_file(
++ update_mode,
++ Path::new("book/src/README.md"),
++ "[There are over ",
++ " lints included in this crate!]",
++ |res| {
++ write!(res, "{}", round_to_fifty(usable_lints.len())).unwrap();
++ },
++ );
++
+ replace_region_in_file(
+ update_mode,
+ Path::new("CHANGELOG.md"),
+ "<!-- begin autogenerated links to lint list -->\n",
+ "<!-- end autogenerated links to lint list -->",
+ |res| {
+ for lint in usable_lints
+ .iter()
+ .map(|l| &*l.name)
+ .chain(deprecated_lints.iter().map(|l| &*l.name))
+ .chain(
+ renamed_lints
+ .iter()
+ .map(|l| l.old_name.strip_prefix("clippy::").unwrap_or(&l.old_name)),
+ )
+ .sorted()
+ {
+ writeln!(res, "[`{}`]: {}#{}", lint, DOCS_LINK, lint).unwrap();
+ }
+ },
+ );
+
+ // This has to be in lib.rs, otherwise rustfmt doesn't work
+ replace_region_in_file(
+ update_mode,
+ Path::new("clippy_lints/src/lib.rs"),
+ "// begin lints modules, do not remove this comment, it’s used in `update_lints`\n",
+ "// end lints modules, do not remove this comment, it’s used in `update_lints`",
+ |res| {
+ for lint_mod in usable_lints.iter().map(|l| &l.module).unique().sorted() {
+ writeln!(res, "mod {};", lint_mod).unwrap();
+ }
+ },
+ );
+
+ process_file(
+ "clippy_lints/src/lib.register_lints.rs",
+ update_mode,
+ &gen_register_lint_list(internal_lints.iter(), usable_lints.iter()),
+ );
+ process_file(
+ "clippy_lints/src/lib.deprecated.rs",
+ update_mode,
+ &gen_deprecated(deprecated_lints),
+ );
+
+ let all_group_lints = usable_lints.iter().filter(|l| {
+ matches!(
+ &*l.group,
+ "correctness" | "suspicious" | "style" | "complexity" | "perf"
+ )
+ });
+ let content = gen_lint_group_list("all", all_group_lints);
+ process_file("clippy_lints/src/lib.register_all.rs", update_mode, &content);
+
+ for (lint_group, lints) in Lint::by_lint_group(usable_lints.into_iter().chain(internal_lints)) {
+ let content = gen_lint_group_list(&lint_group, lints.iter());
+ process_file(
+ &format!("clippy_lints/src/lib.register_{}.rs", lint_group),
+ update_mode,
+ &content,
+ );
+ }
+
+ let content = gen_deprecated_lints_test(deprecated_lints);
+ process_file("tests/ui/deprecated.rs", update_mode, &content);
+
+ let content = gen_renamed_lints_test(renamed_lints);
+ process_file("tests/ui/rename.rs", update_mode, &content);
+}
+
+pub fn print_lints() {
+ let (lint_list, _, _) = gather_all();
+ let usable_lints = Lint::usable_lints(&lint_list);
+ let usable_lint_count = usable_lints.len();
+ let grouped_by_lint_group = Lint::by_lint_group(usable_lints.into_iter());
+
+ for (lint_group, mut lints) in grouped_by_lint_group {
+ println!("\n## {}", lint_group);
+
+ lints.sort_by_key(|l| l.name.clone());
+
+ for lint in lints {
+ println!("* [{}]({}#{}) ({})", lint.name, DOCS_LINK, lint.name, lint.desc);
+ }
+ }
+
+ println!("there are {} lints", usable_lint_count);
+}
+
+/// Runs the `rename_lint` command.
+///
+/// This does the following:
+/// * Adds an entry to `renamed_lints.rs`.
+/// * Renames all lint attributes to the new name (e.g. `#[allow(clippy::lint_name)]`).
+/// * Renames the lint struct to the new name.
+/// * Renames the module containing the lint struct to the new name if it shares a name with the
+/// lint.
+///
+/// # Panics
+/// Panics for the following conditions:
+/// * If a file path could not read from or then written to
+/// * If either lint name has a prefix
+/// * If `old_name` doesn't name an existing lint.
+/// * If `old_name` names a deprecated or renamed lint.
+#[allow(clippy::too_many_lines)]
+pub fn rename(old_name: &str, new_name: &str, uplift: bool) {
+ if let Some((prefix, _)) = old_name.split_once("::") {
+ panic!("`{}` should not contain the `{}` prefix", old_name, prefix);
+ }
+ if let Some((prefix, _)) = new_name.split_once("::") {
+ panic!("`{}` should not contain the `{}` prefix", new_name, prefix);
+ }
+
+ let (mut lints, deprecated_lints, mut renamed_lints) = gather_all();
+ let mut old_lint_index = None;
+ let mut found_new_name = false;
+ for (i, lint) in lints.iter().enumerate() {
+ if lint.name == old_name {
+ old_lint_index = Some(i);
+ } else if lint.name == new_name {
+ found_new_name = true;
+ }
+ }
+ let old_lint_index = old_lint_index.unwrap_or_else(|| panic!("could not find lint `{}`", old_name));
+
+ let lint = RenamedLint {
+ old_name: format!("clippy::{}", old_name),
+ new_name: if uplift {
+ new_name.into()
+ } else {
+ format!("clippy::{}", new_name)
+ },
+ };
+
+ // Renamed lints and deprecated lints shouldn't have been found in the lint list, but check just in
+ // case.
+ assert!(
+ !renamed_lints.iter().any(|l| lint.old_name == l.old_name),
+ "`{}` has already been renamed",
+ old_name
+ );
+ assert!(
+ !deprecated_lints.iter().any(|l| lint.old_name == l.name),
+ "`{}` has already been deprecated",
+ old_name
+ );
+
+ // Update all lint level attributes. (`clippy::lint_name`)
+ for file in WalkDir::new(clippy_project_root())
+ .into_iter()
+ .map(Result::unwrap)
+ .filter(|f| {
+ let name = f.path().file_name();
+ let ext = f.path().extension();
+ (ext == Some(OsStr::new("rs")) || ext == Some(OsStr::new("fixed")))
+ && name != Some(OsStr::new("rename.rs"))
+ && name != Some(OsStr::new("renamed_lints.rs"))
+ })
+ {
+ rewrite_file(file.path(), |s| {
+ replace_ident_like(s, &[(&lint.old_name, &lint.new_name)])
+ });
+ }
+
+ renamed_lints.push(lint);
+ renamed_lints.sort_by(|lhs, rhs| {
+ lhs.new_name
+ .starts_with("clippy::")
+ .cmp(&rhs.new_name.starts_with("clippy::"))
+ .reverse()
+ .then_with(|| lhs.old_name.cmp(&rhs.old_name))
+ });
+
+ write_file(
+ Path::new("clippy_lints/src/renamed_lints.rs"),
+ &gen_renamed_lints_list(&renamed_lints),
+ );
+
+ if uplift {
+ write_file(Path::new("tests/ui/rename.rs"), &gen_renamed_lints_test(&renamed_lints));
+ println!(
+ "`{}` has be uplifted. All the code inside `clippy_lints` related to it needs to be removed manually.",
+ old_name
+ );
+ } else if found_new_name {
+ write_file(Path::new("tests/ui/rename.rs"), &gen_renamed_lints_test(&renamed_lints));
+ println!(
+ "`{}` is already defined. The old linting code inside `clippy_lints` needs to be updated/removed manually.",
+ new_name
+ );
+ } else {
+ // Rename the lint struct and source files sharing a name with the lint.
+ let lint = &mut lints[old_lint_index];
+ let old_name_upper = old_name.to_uppercase();
+ let new_name_upper = new_name.to_uppercase();
+ lint.name = new_name.into();
+
+ // Rename test files. only rename `.stderr` and `.fixed` files if the new test name doesn't exist.
+ if try_rename_file(
+ Path::new(&format!("tests/ui/{}.rs", old_name)),
+ Path::new(&format!("tests/ui/{}.rs", new_name)),
+ ) {
+ try_rename_file(
+ Path::new(&format!("tests/ui/{}.stderr", old_name)),
+ Path::new(&format!("tests/ui/{}.stderr", new_name)),
+ );
+ try_rename_file(
+ Path::new(&format!("tests/ui/{}.fixed", old_name)),
+ Path::new(&format!("tests/ui/{}.fixed", new_name)),
+ );
+ }
+
+ // Try to rename the file containing the lint if the file name matches the lint's name.
+ let replacements;
+ let replacements = if lint.module == old_name
+ && try_rename_file(
+ Path::new(&format!("clippy_lints/src/{}.rs", old_name)),
+ Path::new(&format!("clippy_lints/src/{}.rs", new_name)),
+ ) {
+ // Edit the module name in the lint list. Note there could be multiple lints.
+ for lint in lints.iter_mut().filter(|l| l.module == old_name) {
+ lint.module = new_name.into();
+ }
+ replacements = [(&*old_name_upper, &*new_name_upper), (old_name, new_name)];
+ replacements.as_slice()
+ } else if !lint.module.contains("::")
+ // Catch cases like `methods/lint_name.rs` where the lint is stored in `methods/mod.rs`
+ && try_rename_file(
+ Path::new(&format!("clippy_lints/src/{}/{}.rs", lint.module, old_name)),
+ Path::new(&format!("clippy_lints/src/{}/{}.rs", lint.module, new_name)),
+ )
+ {
+ // Edit the module name in the lint list. Note there could be multiple lints, or none.
+ let renamed_mod = format!("{}::{}", lint.module, old_name);
+ for lint in lints.iter_mut().filter(|l| l.module == renamed_mod) {
+ lint.module = format!("{}::{}", lint.module, new_name);
+ }
+ replacements = [(&*old_name_upper, &*new_name_upper), (old_name, new_name)];
+ replacements.as_slice()
+ } else {
+ replacements = [(&*old_name_upper, &*new_name_upper), ("", "")];
+ &replacements[0..1]
+ };
+
+ // Don't change `clippy_utils/src/renamed_lints.rs` here as it would try to edit the lint being
+ // renamed.
+ for (_, file) in clippy_lints_src_files().filter(|(rel_path, _)| rel_path != OsStr::new("renamed_lints.rs")) {
+ rewrite_file(file.path(), |s| replace_ident_like(s, replacements));
+ }
+
+ generate_lint_files(UpdateMode::Change, &lints, &deprecated_lints, &renamed_lints);
+ println!("{} has been successfully renamed", old_name);
+ }
+
+ println!("note: `cargo uitest` still needs to be run to update the test results");
+}
+
+/// Replace substrings if they aren't bordered by identifier characters. Returns `None` if there
+/// were no replacements.
+fn replace_ident_like(contents: &str, replacements: &[(&str, &str)]) -> Option<String> {
+ fn is_ident_char(c: u8) -> bool {
+ matches!(c, b'a'..=b'z' | b'A'..=b'Z' | b'0'..=b'9' | b'_')
+ }
+
+ let searcher = AhoCorasickBuilder::new()
+ .dfa(true)
+ .match_kind(aho_corasick::MatchKind::LeftmostLongest)
+ .build_with_size::<u16, _, _>(replacements.iter().map(|&(x, _)| x.as_bytes()))
+ .unwrap();
+
+ let mut result = String::with_capacity(contents.len() + 1024);
+ let mut pos = 0;
+ let mut edited = false;
+ for m in searcher.find_iter(contents) {
+ let (old, new) = replacements[m.pattern()];
+ result.push_str(&contents[pos..m.start()]);
+ result.push_str(
+ if !is_ident_char(contents.as_bytes().get(m.start().wrapping_sub(1)).copied().unwrap_or(0))
+ && !is_ident_char(contents.as_bytes().get(m.end()).copied().unwrap_or(0))
+ {
+ edited = true;
+ new
+ } else {
+ old
+ },
+ );
+ pos = m.end();
+ }
+ result.push_str(&contents[pos..]);
+ edited.then(|| result)
+}
+
+fn round_to_fifty(count: usize) -> usize {
+ count / 50 * 50
+}
+
+fn process_file(path: impl AsRef<Path>, update_mode: UpdateMode, content: &str) {
+ if update_mode == UpdateMode::Check {
+ let old_content =
+ fs::read_to_string(&path).unwrap_or_else(|e| panic!("Cannot read from {}: {}", path.as_ref().display(), e));
+ if content != old_content {
+ exit_with_failure();
+ }
+ } else {
+ fs::write(&path, content.as_bytes())
+ .unwrap_or_else(|e| panic!("Cannot write to {}: {}", path.as_ref().display(), e));
+ }
+}
+
+fn exit_with_failure() {
+ println!(
+ "Not all lints defined properly. \
+ Please run `cargo dev update_lints` to make sure all lints are defined properly."
+ );
+ std::process::exit(1);
+}
+
+/// Lint data parsed from the Clippy source code.
+#[derive(Clone, PartialEq, Eq, Debug)]
+struct Lint {
+ name: String,
+ group: String,
+ desc: String,
+ module: String,
+}
+
+impl Lint {
+ #[must_use]
+ fn new(name: &str, group: &str, desc: &str, module: &str) -> Self {
+ Self {
+ name: name.to_lowercase(),
+ group: group.into(),
+ desc: remove_line_splices(desc),
+ module: module.into(),
+ }
+ }
+
+ /// Returns all non-deprecated lints and non-internal lints
+ #[must_use]
+ fn usable_lints(lints: &[Self]) -> Vec<Self> {
+ lints
+ .iter()
+ .filter(|l| !l.group.starts_with("internal"))
+ .cloned()
+ .collect()
+ }
+
+ /// Returns all internal lints (not `internal_warn` lints)
+ #[must_use]
+ fn internal_lints(lints: &[Self]) -> Vec<Self> {
+ lints.iter().filter(|l| l.group == "internal").cloned().collect()
+ }
+
+ /// Returns the lints in a `HashMap`, grouped by the different lint groups
+ #[must_use]
+ fn by_lint_group(lints: impl Iterator<Item = Self>) -> HashMap<String, Vec<Self>> {
+ lints.map(|lint| (lint.group.to_string(), lint)).into_group_map()
+ }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+struct DeprecatedLint {
+ name: String,
+ reason: String,
+}
+impl DeprecatedLint {
+ fn new(name: &str, reason: &str) -> Self {
+ Self {
+ name: name.to_lowercase(),
+ reason: remove_line_splices(reason),
+ }
+ }
+}
+
+struct RenamedLint {
+ old_name: String,
+ new_name: String,
+}
+impl RenamedLint {
+ fn new(old_name: &str, new_name: &str) -> Self {
+ Self {
+ old_name: remove_line_splices(old_name),
+ new_name: remove_line_splices(new_name),
+ }
+ }
+}
+
+/// Generates the code for registering a group
+fn gen_lint_group_list<'a>(group_name: &str, lints: impl Iterator<Item = &'a Lint>) -> String {
+ let mut details: Vec<_> = lints.map(|l| (&l.module, l.name.to_uppercase())).collect();
+ details.sort_unstable();
+
+ let mut output = GENERATED_FILE_COMMENT.to_string();
+
+ let _ = writeln!(
+ output,
+ "store.register_group(true, \"clippy::{0}\", Some(\"clippy_{0}\"), vec![",
+ group_name
+ );
+ for (module, name) in details {
+ let _ = writeln!(output, " LintId::of({}::{}),", module, name);
+ }
+ output.push_str("])\n");
+
+ output
+}
+
+/// Generates the `register_removed` code
+#[must_use]
+fn gen_deprecated(lints: &[DeprecatedLint]) -> String {
+ let mut output = GENERATED_FILE_COMMENT.to_string();
+ output.push_str("{\n");
+ for lint in lints {
+ let _ = write!(
+ output,
+ concat!(
+ " store.register_removed(\n",
+ " \"clippy::{}\",\n",
+ " \"{}\",\n",
+ " );\n"
+ ),
+ lint.name, lint.reason,
+ );
+ }
+ output.push_str("}\n");
+
+ output
+}
+
+/// Generates the code for registering lints
+#[must_use]
+fn gen_register_lint_list<'a>(
+ internal_lints: impl Iterator<Item = &'a Lint>,
+ usable_lints: impl Iterator<Item = &'a Lint>,
+) -> String {
+ let mut details: Vec<_> = internal_lints
+ .map(|l| (false, &l.module, l.name.to_uppercase()))
+ .chain(usable_lints.map(|l| (true, &l.module, l.name.to_uppercase())))
+ .collect();
+ details.sort_unstable();
+
+ let mut output = GENERATED_FILE_COMMENT.to_string();
+ output.push_str("store.register_lints(&[\n");
+
+ for (is_public, module_name, lint_name) in details {
+ if !is_public {
+ output.push_str(" #[cfg(feature = \"internal\")]\n");
+ }
+ let _ = writeln!(output, " {}::{},", module_name, lint_name);
+ }
+ output.push_str("])\n");
+
+ output
+}
+
+fn gen_deprecated_lints_test(lints: &[DeprecatedLint]) -> String {
+ let mut res: String = GENERATED_FILE_COMMENT.into();
+ for lint in lints {
+ writeln!(res, "#![warn(clippy::{})]", lint.name).unwrap();
+ }
+ res.push_str("\nfn main() {}\n");
+ res
+}
+
+fn gen_renamed_lints_test(lints: &[RenamedLint]) -> String {
+ let mut seen_lints = HashSet::new();
+ let mut res: String = GENERATED_FILE_COMMENT.into();
+ res.push_str("// run-rustfix\n\n");
+ for lint in lints {
+ if seen_lints.insert(&lint.new_name) {
+ writeln!(res, "#![allow({})]", lint.new_name).unwrap();
+ }
+ }
+ seen_lints.clear();
+ for lint in lints {
+ if seen_lints.insert(&lint.old_name) {
+ writeln!(res, "#![warn({})]", lint.old_name).unwrap();
+ }
+ }
+ res.push_str("\nfn main() {}\n");
+ res
+}
+
+fn gen_renamed_lints_list(lints: &[RenamedLint]) -> String {
+ const HEADER: &str = "\
+ // This file is managed by `cargo dev rename_lint`. Prefer using that when possible.\n\n\
+ #[rustfmt::skip]\n\
+ pub static RENAMED_LINTS: &[(&str, &str)] = &[\n";
+
+ let mut res = String::from(HEADER);
+ for lint in lints {
+ writeln!(res, " (\"{}\", \"{}\"),", lint.old_name, lint.new_name).unwrap();
+ }
+ res.push_str("];\n");
+ res
+}
+
+/// Gathers all lints defined in `clippy_lints/src`
+fn gather_all() -> (Vec<Lint>, Vec<DeprecatedLint>, Vec<RenamedLint>) {
+ let mut lints = Vec::with_capacity(1000);
+ let mut deprecated_lints = Vec::with_capacity(50);
+ let mut renamed_lints = Vec::with_capacity(50);
+
+ for (rel_path, file) in clippy_lints_src_files() {
+ let path = file.path();
+ let contents =
+ fs::read_to_string(path).unwrap_or_else(|e| panic!("Cannot read from `{}`: {}", path.display(), e));
+ let module = rel_path
+ .components()
+ .map(|c| c.as_os_str().to_str().unwrap())
+ .collect::<Vec<_>>()
+ .join("::");
+
+ // If the lints are stored in mod.rs, we get the module name from
+ // the containing directory:
+ let module = if let Some(module) = module.strip_suffix("::mod.rs") {
+ module
+ } else {
+ module.strip_suffix(".rs").unwrap_or(&module)
+ };
+
+ match module {
+ "deprecated_lints" => parse_deprecated_contents(&contents, &mut deprecated_lints),
+ "renamed_lints" => parse_renamed_contents(&contents, &mut renamed_lints),
+ _ => parse_contents(&contents, module, &mut lints),
+ }
+ }
+ (lints, deprecated_lints, renamed_lints)
+}
+
+fn clippy_lints_src_files() -> impl Iterator<Item = (PathBuf, DirEntry)> {
+ let root_path = clippy_project_root().join("clippy_lints/src");
+ let iter = WalkDir::new(&root_path).into_iter();
+ iter.map(Result::unwrap)
+ .filter(|f| f.path().extension() == Some(OsStr::new("rs")))
+ .map(move |f| (f.path().strip_prefix(&root_path).unwrap().to_path_buf(), f))
+}
+
+macro_rules! match_tokens {
+ ($iter:ident, $($token:ident $({$($fields:tt)*})? $(($capture:ident))?)*) => {
+ {
+ $($(let $capture =)? if let Some((TokenKind::$token $({$($fields)*})?, _x)) = $iter.next() {
+ _x
+ } else {
+ continue;
+ };)*
+ #[allow(clippy::unused_unit)]
+ { ($($($capture,)?)*) }
+ }
+ }
+}
+
+/// Parse a source file looking for `declare_clippy_lint` macro invocations.
+fn parse_contents(contents: &str, module: &str, lints: &mut Vec<Lint>) {
+ let mut offset = 0usize;
+ let mut iter = tokenize(contents).map(|t| {
+ let range = offset..offset + t.len;
+ offset = range.end;
+ (t.kind, &contents[range])
+ });
+
+ while iter.any(|(kind, s)| kind == TokenKind::Ident && s == "declare_clippy_lint") {
+ let mut iter = iter
+ .by_ref()
+ .filter(|&(kind, _)| !matches!(kind, TokenKind::Whitespace | TokenKind::LineComment { .. }));
+ // matches `!{`
+ match_tokens!(iter, Bang OpenBrace);
+ match iter.next() {
+ // #[clippy::version = "version"] pub
+ Some((TokenKind::Pound, _)) => {
+ match_tokens!(iter, OpenBracket Ident Colon Colon Ident Eq Literal{..} CloseBracket Ident);
+ },
+ // pub
+ Some((TokenKind::Ident, _)) => (),
+ _ => continue,
+ }
+ let (name, group, desc) = match_tokens!(
+ iter,
+ // LINT_NAME
+ Ident(name) Comma
+ // group,
+ Ident(group) Comma
+ // "description" }
+ Literal{..}(desc) CloseBrace
+ );
+ lints.push(Lint::new(name, group, desc, module));
+ }
+}
+
+/// Parse a source file looking for `declare_deprecated_lint` macro invocations.
+fn parse_deprecated_contents(contents: &str, lints: &mut Vec<DeprecatedLint>) {
+ let mut offset = 0usize;
+ let mut iter = tokenize(contents).map(|t| {
+ let range = offset..offset + t.len;
+ offset = range.end;
+ (t.kind, &contents[range])
+ });
+ while iter.any(|(kind, s)| kind == TokenKind::Ident && s == "declare_deprecated_lint") {
+ let mut iter = iter
+ .by_ref()
+ .filter(|&(kind, _)| !matches!(kind, TokenKind::Whitespace | TokenKind::LineComment { .. }));
+ let (name, reason) = match_tokens!(
+ iter,
+ // !{
+ Bang OpenBrace
+ // #[clippy::version = "version"]
+ Pound OpenBracket Ident Colon Colon Ident Eq Literal{..} CloseBracket
+ // pub LINT_NAME,
+ Ident Ident(name) Comma
+ // "description"
+ Literal{kind: LiteralKind::Str{..},..}(reason)
+ // }
+ CloseBrace
+ );
+ lints.push(DeprecatedLint::new(name, reason));
+ }
+}
+
+fn parse_renamed_contents(contents: &str, lints: &mut Vec<RenamedLint>) {
+ for line in contents.lines() {
+ let mut offset = 0usize;
+ let mut iter = tokenize(line).map(|t| {
+ let range = offset..offset + t.len;
+ offset = range.end;
+ (t.kind, &line[range])
+ });
+ let (old_name, new_name) = match_tokens!(
+ iter,
+ // ("old_name",
+ Whitespace OpenParen Literal{kind: LiteralKind::Str{..},..}(old_name) Comma
+ // "new_name"),
+ Whitespace Literal{kind: LiteralKind::Str{..},..}(new_name) CloseParen Comma
+ );
+ lints.push(RenamedLint::new(old_name, new_name));
+ }
+}
+
+/// Removes the line splices and surrounding quotes from a string literal
+fn remove_line_splices(s: &str) -> String {
+ let s = s
+ .strip_prefix('r')
+ .unwrap_or(s)
+ .trim_matches('#')
+ .strip_prefix('"')
+ .and_then(|s| s.strip_suffix('"'))
+ .unwrap_or_else(|| panic!("expected quoted string, found `{}`", s));
+ let mut res = String::with_capacity(s.len());
+ unescape::unescape_literal(s, unescape::Mode::Str, &mut |range, _| res.push_str(&s[range]));
+ res
+}
+
+/// Replaces a region in a file delimited by two lines matching regexes.
+///
+/// `path` is the relative path to the file on which you want to perform the replacement.
+///
+/// See `replace_region_in_text` for documentation of the other options.
+///
+/// # Panics
+///
+/// Panics if the path could not read or then written
+fn replace_region_in_file(
+ update_mode: UpdateMode,
+ path: &Path,
+ start: &str,
+ end: &str,
+ write_replacement: impl FnMut(&mut String),
+) {
+ let contents = fs::read_to_string(path).unwrap_or_else(|e| panic!("Cannot read from `{}`: {}", path.display(), e));
+ let new_contents = match replace_region_in_text(&contents, start, end, write_replacement) {
+ Ok(x) => x,
+ Err(delim) => panic!("Couldn't find `{}` in file `{}`", delim, path.display()),
+ };
+
+ match update_mode {
+ UpdateMode::Check if contents != new_contents => exit_with_failure(),
+ UpdateMode::Check => (),
+ UpdateMode::Change => {
+ if let Err(e) = fs::write(path, new_contents.as_bytes()) {
+ panic!("Cannot write to `{}`: {}", path.display(), e);
+ }
+ },
+ }
+}
+
+/// Replaces a region in a text delimited by two strings. Returns the new text if both delimiters
+/// were found, or the missing delimiter if not.
+fn replace_region_in_text<'a>(
+ text: &str,
+ start: &'a str,
+ end: &'a str,
+ mut write_replacement: impl FnMut(&mut String),
+) -> Result<String, &'a str> {
+ let (text_start, rest) = text.split_once(start).ok_or(start)?;
+ let (_, text_end) = rest.split_once(end).ok_or(end)?;
+
+ let mut res = String::with_capacity(text.len() + 4096);
+ res.push_str(text_start);
+ res.push_str(start);
+ write_replacement(&mut res);
+ res.push_str(end);
+ res.push_str(text_end);
+
+ Ok(res)
+}
+
+fn try_rename_file(old_name: &Path, new_name: &Path) -> bool {
+ match fs::OpenOptions::new().create_new(true).write(true).open(new_name) {
+ Ok(file) => drop(file),
+ Err(e) if matches!(e.kind(), io::ErrorKind::AlreadyExists | io::ErrorKind::NotFound) => return false,
+ Err(e) => panic_file(e, new_name, "create"),
+ };
+ match fs::rename(old_name, new_name) {
+ Ok(()) => true,
+ Err(e) => {
+ drop(fs::remove_file(new_name));
+ if e.kind() == io::ErrorKind::NotFound {
+ false
+ } else {
+ panic_file(e, old_name, "rename");
+ }
+ },
+ }
+}
+
+#[allow(clippy::needless_pass_by_value)]
+fn panic_file(error: io::Error, name: &Path, action: &str) -> ! {
+ panic!("failed to {} file `{}`: {}", action, name.display(), error)
+}
+
+fn rewrite_file(path: &Path, f: impl FnOnce(&str) -> Option<String>) {
+ let mut file = fs::OpenOptions::new()
+ .write(true)
+ .read(true)
+ .open(path)
+ .unwrap_or_else(|e| panic_file(e, path, "open"));
+ let mut buf = String::new();
+ file.read_to_string(&mut buf)
+ .unwrap_or_else(|e| panic_file(e, path, "read"));
+ if let Some(new_contents) = f(&buf) {
+ file.rewind().unwrap_or_else(|e| panic_file(e, path, "write"));
+ file.write_all(new_contents.as_bytes())
+ .unwrap_or_else(|e| panic_file(e, path, "write"));
+ file.set_len(new_contents.len() as u64)
+ .unwrap_or_else(|e| panic_file(e, path, "write"));
+ }
+}
+
+fn write_file(path: &Path, contents: &str) {
+ fs::write(path, contents).unwrap_or_else(|e| panic_file(e, path, "write"));
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ #[test]
+ fn test_parse_contents() {
+ static CONTENTS: &str = r#"
+ declare_clippy_lint! {
+ #[clippy::version = "Hello Clippy!"]
+ pub PTR_ARG,
+ style,
+ "really long \
+ text"
+ }
+
+ declare_clippy_lint!{
+ #[clippy::version = "Test version"]
+ pub DOC_MARKDOWN,
+ pedantic,
+ "single line"
+ }
+ "#;
+ let mut result = Vec::new();
+ parse_contents(CONTENTS, "module_name", &mut result);
+
+ let expected = vec![
+ Lint::new("ptr_arg", "style", "\"really long text\"", "module_name"),
+ Lint::new("doc_markdown", "pedantic", "\"single line\"", "module_name"),
+ ];
+ assert_eq!(expected, result);
+ }
+
+ #[test]
+ fn test_parse_deprecated_contents() {
+ static DEPRECATED_CONTENTS: &str = r#"
+ /// some doc comment
+ declare_deprecated_lint! {
+ #[clippy::version = "I'm a version"]
+ pub SHOULD_ASSERT_EQ,
+ "`assert!()` will be more flexible with RFC 2011"
+ }
+ "#;
+
+ let mut result = Vec::new();
+ parse_deprecated_contents(DEPRECATED_CONTENTS, &mut result);
+
+ let expected = vec![DeprecatedLint::new(
+ "should_assert_eq",
+ "\"`assert!()` will be more flexible with RFC 2011\"",
+ )];
+ assert_eq!(expected, result);
+ }
+
+ #[test]
+ fn test_usable_lints() {
+ let lints = vec![
+ Lint::new("should_assert_eq2", "Not Deprecated", "\"abc\"", "module_name"),
+ Lint::new("should_assert_eq2", "internal", "\"abc\"", "module_name"),
+ Lint::new("should_assert_eq2", "internal_style", "\"abc\"", "module_name"),
+ ];
+ let expected = vec![Lint::new(
+ "should_assert_eq2",
+ "Not Deprecated",
+ "\"abc\"",
+ "module_name",
+ )];
+ assert_eq!(expected, Lint::usable_lints(&lints));
+ }
+
+ #[test]
+ fn test_by_lint_group() {
+ let lints = vec![
+ Lint::new("should_assert_eq", "group1", "\"abc\"", "module_name"),
+ Lint::new("should_assert_eq2", "group2", "\"abc\"", "module_name"),
+ Lint::new("incorrect_match", "group1", "\"abc\"", "module_name"),
+ ];
+ let mut expected: HashMap<String, Vec<Lint>> = HashMap::new();
+ expected.insert(
+ "group1".to_string(),
+ vec![
+ Lint::new("should_assert_eq", "group1", "\"abc\"", "module_name"),
+ Lint::new("incorrect_match", "group1", "\"abc\"", "module_name"),
+ ],
+ );
+ expected.insert(
+ "group2".to_string(),
+ vec![Lint::new("should_assert_eq2", "group2", "\"abc\"", "module_name")],
+ );
+ assert_eq!(expected, Lint::by_lint_group(lints.into_iter()));
+ }
+
+ #[test]
+ fn test_gen_deprecated() {
+ let lints = vec![
+ DeprecatedLint::new("should_assert_eq", "\"has been superseded by should_assert_eq2\""),
+ DeprecatedLint::new("another_deprecated", "\"will be removed\""),
+ ];
+
+ let expected = GENERATED_FILE_COMMENT.to_string()
+ + &[
+ "{",
+ " store.register_removed(",
+ " \"clippy::should_assert_eq\",",
+ " \"has been superseded by should_assert_eq2\",",
+ " );",
+ " store.register_removed(",
+ " \"clippy::another_deprecated\",",
+ " \"will be removed\",",
+ " );",
+ "}",
+ ]
+ .join("\n")
+ + "\n";
+
+ assert_eq!(expected, gen_deprecated(&lints));
+ }
+
+ #[test]
+ fn test_gen_lint_group_list() {
+ let lints = vec![
+ Lint::new("abc", "group1", "\"abc\"", "module_name"),
+ Lint::new("should_assert_eq", "group1", "\"abc\"", "module_name"),
+ Lint::new("internal", "internal_style", "\"abc\"", "module_name"),
+ ];
+ let expected = GENERATED_FILE_COMMENT.to_string()
+ + &[
+ "store.register_group(true, \"clippy::group1\", Some(\"clippy_group1\"), vec![",
+ " LintId::of(module_name::ABC),",
+ " LintId::of(module_name::INTERNAL),",
+ " LintId::of(module_name::SHOULD_ASSERT_EQ),",
+ "])",
+ ]
+ .join("\n")
+ + "\n";
+
+ let result = gen_lint_group_list("group1", lints.iter());
+
+ assert_eq!(expected, result);
+ }
+}
--- /dev/null
- internal = ["clippy_utils/internal", "serde_json"]
+[package]
+name = "clippy_lints"
+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"]
+edition = "2021"
+
+[dependencies]
+cargo_metadata = "0.14"
++clippy_dev = { path = "../clippy_dev", optional = true }
+clippy_utils = { path = "../clippy_utils" }
+if_chain = "1.0"
+itertools = "0.10.1"
+pulldown-cmark = { version = "0.9", default-features = false }
+quine-mc_cluskey = "0.2"
+regex-syntax = "0.6"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = { version = "1.0", optional = true }
++tempfile = { version = "3.2", optional = true }
+toml = "0.5"
+unicode-normalization = "0.1"
+unicode-script = { version = "0.5", default-features = false }
+semver = "1.0"
+rustc-semver = "1.1"
+# NOTE: cargo requires serde feat in its url dep
+# see <https://github.com/rust-lang/rust/pull/63587#issuecomment-522343864>
+url = { version = "2.2", features = ["serde"] }
+
+[features]
+deny-warnings = ["clippy_utils/deny-warnings"]
+# build clippy with internal lints enabled, off by default
++internal = ["clippy_utils/internal", "serde_json", "tempfile", "clippy_dev"]
+
+[package.metadata.rust-analyzer]
+# This crate uses #[feature(rustc_private)]
+rustc_private = true
--- /dev/null
- /// ### Known problems
- /// None
- ///
+use clippy_utils::consts::{constant, Constant};
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::macros::{find_assert_args, root_macro_call_first_node, PanicExpn};
+use rustc_hir::Expr;
+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 `assert!(true)` and `assert!(false)` calls.
+ ///
+ /// ### Why is this bad?
+ /// Will be optimized out by the compiler or should probably be replaced by a
+ /// `panic!()` or `unreachable!()`
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// assert!(false)
+ /// assert!(true)
+ /// const B: bool = false;
+ /// assert!(B)
+ /// ```
+ #[clippy::version = "1.34.0"]
+ pub ASSERTIONS_ON_CONSTANTS,
+ style,
+ "`assert!(true)` / `assert!(false)` will be optimized out by the compiler, and should probably be replaced by a `panic!()` or `unreachable!()`"
+}
+
+declare_lint_pass!(AssertionsOnConstants => [ASSERTIONS_ON_CONSTANTS]);
+
+impl<'tcx> LateLintPass<'tcx> for AssertionsOnConstants {
+ 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 is_debug = match cx.tcx.get_diagnostic_name(macro_call.def_id) {
+ Some(sym::debug_assert_macro) => true,
+ Some(sym::assert_macro) => false,
+ _ => return,
+ };
+ let Some((condition, panic_expn)) = find_assert_args(cx, e, macro_call.expn) else { return };
+ let Some((Constant::Bool(val), _)) = constant(cx, cx.typeck_results(), condition) else { return };
+ if val {
+ span_lint_and_help(
+ cx,
+ ASSERTIONS_ON_CONSTANTS,
+ macro_call.span,
+ &format!(
+ "`{}!(true)` will be optimized out by the compiler",
+ cx.tcx.item_name(macro_call.def_id)
+ ),
+ None,
+ "remove it",
+ );
+ } else if !is_debug {
+ let (assert_arg, panic_arg) = match panic_expn {
+ PanicExpn::Empty => ("", ""),
+ _ => (", ..", ".."),
+ };
+ span_lint_and_help(
+ cx,
+ ASSERTIONS_ON_CONSTANTS,
+ macro_call.span,
+ &format!("`assert!(false{})` should probably be replaced", assert_arg),
+ None,
+ &format!("use `panic!({})` or `unreachable!({0})`", panic_arg),
+ );
+ }
+ }
+}
--- /dev/null
- use clippy_utils::diagnostics::span_lint_and_then;
++use clippy_utils::diagnostics::span_lint_hir_and_then;
+use clippy_utils::source::snippet;
+use clippy_utils::ty::implements_trait;
+use rustc_errors::Applicability;
+use rustc_hir::{AsyncGeneratorKind, Body, BodyId, ExprKind, GeneratorKind, QPath};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for async blocks that yield values of types
+ /// that can themselves be awaited.
+ ///
+ /// ### Why is this bad?
+ /// An await is likely missing.
+ ///
+ /// ### Example
+ /// ```rust
+ /// async fn foo() {}
+ ///
+ /// fn bar() {
+ /// let x = async {
+ /// foo()
+ /// };
+ /// }
+ /// ```
++ ///
+ /// Use instead:
+ /// ```rust
+ /// async fn foo() {}
+ ///
+ /// fn bar() {
+ /// let x = async {
+ /// foo().await
+ /// };
+ /// }
+ /// ```
+ #[clippy::version = "1.48.0"]
+ pub ASYNC_YIELDS_ASYNC,
+ correctness,
+ "async blocks that return a type that can be awaited"
+}
+
+declare_lint_pass!(AsyncYieldsAsync => [ASYNC_YIELDS_ASYNC]);
+
+impl<'tcx> LateLintPass<'tcx> for AsyncYieldsAsync {
+ fn check_body(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'_>) {
+ use AsyncGeneratorKind::{Block, Closure};
+ // For functions, with explicitly defined types, don't warn.
+ // XXXkhuey maybe we should?
+ if let Some(GeneratorKind::Async(Block | Closure)) = body.generator_kind {
+ if let Some(future_trait_def_id) = cx.tcx.lang_items().future_trait() {
+ let body_id = BodyId {
+ hir_id: body.value.hir_id,
+ };
+ let typeck_results = cx.tcx.typeck_body(body_id);
+ let expr_ty = typeck_results.expr_ty(&body.value);
+
+ if implements_trait(cx, expr_ty, future_trait_def_id, &[]) {
+ let return_expr_span = match &body.value.kind {
+ // XXXkhuey there has to be a better way.
+ ExprKind::Block(block, _) => block.expr.map(|e| e.span),
+ ExprKind::Path(QPath::Resolved(_, path)) => Some(path.span),
+ _ => None,
+ };
+ if let Some(return_expr_span) = return_expr_span {
- span_lint_and_then(
++ span_lint_hir_and_then(
+ cx,
+ ASYNC_YIELDS_ASYNC,
++ body.value.hir_id,
+ return_expr_span,
+ "an async construct yields a type which is itself awaitable",
+ |db| {
+ db.span_label(body.value.span, "outer async construct");
+ db.span_label(return_expr_span, "awaitable value not awaited");
+ db.span_suggestion(
+ return_expr_span,
+ "consider awaiting this value",
+ format!("{}.await", snippet(cx, return_expr_span, "..")),
+ Applicability::MaybeIncorrect,
+ );
+ },
+ );
+ }
+ }
+ }
+ }
+ }
+}
--- /dev/null
- if is_word(lint, sym!(unused_imports))
+//! 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
+ /// #[deny(dead_code)]
+ /// extern crate foo;
+ /// #[forbid(dead_code)]
+ /// use foo::bar;
+ /// ```
+ ///
+ /// 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() { }
+ ///
+ /// // 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
+ /// ```rust
+ /// #![deny(clippy::restriction)]
+ /// ```
+ ///
+ /// 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
+ /// ```rust
+ /// #[cfg_attr(rustfmt, rustfmt_skip)]
+ /// fn main() { }
+ /// ```
+ ///
+ /// 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
+ /// ```rust
+ /// #[cfg(linux)]
+ /// fn conditional() { }
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// # mod hidden {
+ /// #[cfg(target_os = "linux")]
+ /// fn conditional() { }
+ /// # }
+ ///
+ /// // or
+ ///
+ /// #[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
+ /// ```rust
+ /// #![feature(lint_reasons)]
+ ///
+ /// #![allow(clippy::some_lint)]
+ /// ```
+ ///
+ /// 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)) && skip_unused_imports {
++ 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 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());
+ 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 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
- /// ### Known problems
- ///
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::{match_def_path, paths};
+use rustc_data_structures::fx::FxHashMap;
+use rustc_hir::def_id::DefId;
+use rustc_hir::{def::Res, AsyncGeneratorKind, Body, BodyId, GeneratorKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::GeneratorInteriorTypeCause;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::Span;
+
+use crate::utils::conf::DisallowedType;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calls to await while holding a non-async-aware MutexGuard.
+ ///
+ /// ### Why is this bad?
+ /// The Mutex types found in std::sync and parking_lot
+ /// are not designed to operate in an async context across await points.
+ ///
+ /// There are two potential solutions. One is to use an async-aware Mutex
+ /// type. Many asynchronous foundation crates provide such a Mutex type. The
+ /// other solution is to ensure the mutex is unlocked before calling await,
+ /// either by introducing a scope or an explicit call to Drop::drop.
+ ///
+ /// ### Known problems
+ /// Will report false positive for explicitly dropped guards
+ /// ([#6446](https://github.com/rust-lang/rust-clippy/issues/6446)). A workaround for this is
+ /// to wrap the `.lock()` call in a block instead of explicitly dropping the guard.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::sync::Mutex;
+ /// # async fn baz() {}
+ /// async fn foo(x: &Mutex<u32>) {
+ /// let mut guard = x.lock().unwrap();
+ /// *guard += 1;
+ /// baz().await;
+ /// }
+ ///
+ /// async fn bar(x: &Mutex<u32>) {
+ /// let mut guard = x.lock().unwrap();
+ /// *guard += 1;
+ /// drop(guard); // explicit drop
+ /// baz().await;
+ /// }
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// # use std::sync::Mutex;
+ /// # async fn baz() {}
+ /// async fn foo(x: &Mutex<u32>) {
+ /// {
+ /// let mut guard = x.lock().unwrap();
+ /// *guard += 1;
+ /// }
+ /// baz().await;
+ /// }
+ ///
+ /// async fn bar(x: &Mutex<u32>) {
+ /// {
+ /// let mut guard = x.lock().unwrap();
+ /// *guard += 1;
+ /// } // guard dropped here at end of scope
+ /// baz().await;
+ /// }
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub AWAIT_HOLDING_LOCK,
+ suspicious,
+ "inside an async function, holding a `MutexGuard` while calling `await`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calls to await while holding a `RefCell` `Ref` or `RefMut`.
+ ///
+ /// ### Why is this bad?
+ /// `RefCell` refs only check for exclusive mutable access
+ /// at runtime. Holding onto a `RefCell` ref across an `await` suspension point
+ /// risks panics from a mutable ref shared while other refs are outstanding.
+ ///
+ /// ### Known problems
+ /// Will report false positive for explicitly dropped refs
+ /// ([#6353](https://github.com/rust-lang/rust-clippy/issues/6353)). A workaround for this is
+ /// to wrap the `.borrow[_mut]()` call in a block instead of explicitly dropping the ref.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::cell::RefCell;
+ /// # async fn baz() {}
+ /// async fn foo(x: &RefCell<u32>) {
+ /// let mut y = x.borrow_mut();
+ /// *y += 1;
+ /// baz().await;
+ /// }
+ ///
+ /// async fn bar(x: &RefCell<u32>) {
+ /// let mut y = x.borrow_mut();
+ /// *y += 1;
+ /// drop(y); // explicit drop
+ /// baz().await;
+ /// }
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// # use std::cell::RefCell;
+ /// # async fn baz() {}
+ /// async fn foo(x: &RefCell<u32>) {
+ /// {
+ /// let mut y = x.borrow_mut();
+ /// *y += 1;
+ /// }
+ /// baz().await;
+ /// }
+ ///
+ /// async fn bar(x: &RefCell<u32>) {
+ /// {
+ /// let mut y = x.borrow_mut();
+ /// *y += 1;
+ /// } // y dropped here at end of scope
+ /// baz().await;
+ /// }
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub AWAIT_HOLDING_REFCELL_REF,
+ suspicious,
+ "inside an async function, holding a `RefCell` ref while calling `await`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Allows users to configure types which should not be held across `await`
+ /// suspension points.
+ ///
+ /// ### Why is this bad?
+ /// There are some types which are perfectly "safe" to be used concurrently
+ /// from a memory access perspective but will cause bugs at runtime if they
+ /// are held in such a way.
+ ///
+ /// ### Example
+ ///
+ /// ```toml
+ /// await-holding-invalid-types = [
+ /// # You can specify a type name
+ /// "CustomLockType",
+ /// # You can (optionally) specify a reason
+ /// { path = "OtherCustomLockType", reason = "Relies on a thread local" }
+ /// ]
+ /// ```
+ ///
+ /// ```rust
+ /// # async fn baz() {}
+ /// struct CustomLockType;
+ /// struct OtherCustomLockType;
+ /// async fn foo() {
+ /// let _x = CustomLockType;
+ /// let _y = OtherCustomLockType;
+ /// baz().await; // Lint violation
+ /// }
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub AWAIT_HOLDING_INVALID_TYPE,
+ suspicious,
+ "holding a type across an await point which is not allowed to be held as per the configuration"
+}
+
+impl_lint_pass!(AwaitHolding => [AWAIT_HOLDING_LOCK, AWAIT_HOLDING_REFCELL_REF, AWAIT_HOLDING_INVALID_TYPE]);
+
+#[derive(Debug)]
+pub struct AwaitHolding {
+ conf_invalid_types: Vec<DisallowedType>,
+ def_ids: FxHashMap<DefId, DisallowedType>,
+}
+
+impl AwaitHolding {
+ pub(crate) fn new(conf_invalid_types: Vec<DisallowedType>) -> Self {
+ Self {
+ conf_invalid_types,
+ def_ids: FxHashMap::default(),
+ }
+ }
+}
+
+impl LateLintPass<'_> for AwaitHolding {
+ fn check_crate(&mut self, cx: &LateContext<'_>) {
+ for conf in &self.conf_invalid_types {
+ let path = match conf {
+ DisallowedType::Simple(path) | DisallowedType::WithReason { path, .. } => path,
+ };
+ let segs: Vec<_> = path.split("::").collect();
+ if let Res::Def(_, id) = clippy_utils::def_path_res(cx, &segs) {
+ self.def_ids.insert(id, conf.clone());
+ }
+ }
+ }
+
+ fn check_body(&mut self, cx: &LateContext<'_>, body: &'_ Body<'_>) {
+ use AsyncGeneratorKind::{Block, Closure, Fn};
+ if let Some(GeneratorKind::Async(Block | Closure | Fn)) = body.generator_kind {
+ let body_id = BodyId {
+ hir_id: body.value.hir_id,
+ };
+ let typeck_results = cx.tcx.typeck_body(body_id);
+ self.check_interior_types(
+ cx,
+ typeck_results.generator_interior_types.as_ref().skip_binder(),
+ body.value.span,
+ );
+ }
+ }
+}
+
+impl AwaitHolding {
+ fn check_interior_types(&self, cx: &LateContext<'_>, ty_causes: &[GeneratorInteriorTypeCause<'_>], span: Span) {
+ for ty_cause in ty_causes {
+ if let rustc_middle::ty::Adt(adt, _) = ty_cause.ty.kind() {
+ if is_mutex_guard(cx, adt.did()) {
+ span_lint_and_then(
+ cx,
+ AWAIT_HOLDING_LOCK,
+ ty_cause.span,
+ "this `MutexGuard` is held across an `await` point",
+ |diag| {
+ diag.help(
+ "consider using an async-aware `Mutex` type or ensuring the \
+ `MutexGuard` is dropped before calling await",
+ );
+ diag.span_note(
+ ty_cause.scope_span.unwrap_or(span),
+ "these are all the `await` points this lock is held through",
+ );
+ },
+ );
+ } else if is_refcell_ref(cx, adt.did()) {
+ span_lint_and_then(
+ cx,
+ AWAIT_HOLDING_REFCELL_REF,
+ ty_cause.span,
+ "this `RefCell` reference is held across an `await` point",
+ |diag| {
+ diag.help("ensure the reference is dropped before calling `await`");
+ diag.span_note(
+ ty_cause.scope_span.unwrap_or(span),
+ "these are all the `await` points this reference is held through",
+ );
+ },
+ );
+ } else if let Some(disallowed) = self.def_ids.get(&adt.did()) {
+ emit_invalid_type(cx, ty_cause.span, disallowed);
+ }
+ }
+ }
+ }
+}
+
+fn emit_invalid_type(cx: &LateContext<'_>, span: Span, disallowed: &DisallowedType) {
+ let (type_name, reason) = match disallowed {
+ DisallowedType::Simple(path) => (path, &None),
+ DisallowedType::WithReason { path, reason } => (path, reason),
+ };
+
+ span_lint_and_then(
+ cx,
+ AWAIT_HOLDING_INVALID_TYPE,
+ span,
+ &format!("`{type_name}` may not be held across an `await` point per `clippy.toml`",),
+ |diag| {
+ if let Some(reason) = reason {
+ diag.note(reason.clone());
+ }
+ },
+ );
+}
+
+fn is_mutex_guard(cx: &LateContext<'_>, def_id: DefId) -> bool {
+ match_def_path(cx, def_id, &paths::MUTEX_GUARD)
+ || match_def_path(cx, def_id, &paths::RWLOCK_READ_GUARD)
+ || match_def_path(cx, def_id, &paths::RWLOCK_WRITE_GUARD)
+ || match_def_path(cx, def_id, &paths::PARKING_LOT_MUTEX_GUARD)
+ || match_def_path(cx, def_id, &paths::PARKING_LOT_RWLOCK_READ_GUARD)
+ || match_def_path(cx, def_id, &paths::PARKING_LOT_RWLOCK_WRITE_GUARD)
+}
+
+fn is_refcell_ref(cx: &LateContext<'_>, def_id: DefId) -> bool {
+ match_def_path(cx, def_id, &paths::REFCELL_REF) || match_def_path(cx, def_id, &paths::REFCELL_REFMUT)
+}
--- /dev/null
- /// // Bad
+use clippy_utils::macros::{find_assert_eq_args, root_macro_call_first_node};
+use clippy_utils::{diagnostics::span_lint_and_sugg, ty::implements_trait};
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind, Lit};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::Ident;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint warns about boolean comparisons in assert-like macros.
+ ///
+ /// ### Why is this bad?
+ /// It is shorter to use the equivalent.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// assert_eq!("a".is_empty(), false);
+ /// assert_ne!("a".is_empty(), true);
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
+ /// assert!(!"a".is_empty());
+ /// ```
+ #[clippy::version = "1.53.0"]
+ pub BOOL_ASSERT_COMPARISON,
+ style,
+ "Using a boolean as comparison value in an assert_* macro when there is no need"
+}
+
+declare_lint_pass!(BoolAssertComparison => [BOOL_ASSERT_COMPARISON]);
+
+fn is_bool_lit(e: &Expr<'_>) -> bool {
+ matches!(
+ e.kind,
+ ExprKind::Lit(Lit {
+ node: LitKind::Bool(_),
+ ..
+ })
+ ) && !e.span.from_expansion()
+}
+
+fn is_impl_not_trait_with_bool_out(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
+ let ty = cx.typeck_results().expr_ty(e);
+
+ cx.tcx
+ .lang_items()
+ .not_trait()
+ .filter(|trait_id| implements_trait(cx, ty, *trait_id, &[]))
+ .and_then(|trait_id| {
+ cx.tcx.associated_items(trait_id).find_by_name_and_kind(
+ cx.tcx,
+ Ident::from_str("Output"),
+ ty::AssocKind::Type,
+ trait_id,
+ )
+ })
+ .map_or(false, |assoc_item| {
+ let proj = cx.tcx.mk_projection(assoc_item.def_id, cx.tcx.mk_substs_trait(ty, &[]));
+ let nty = cx.tcx.normalize_erasing_regions(cx.param_env, proj);
+
+ nty.is_bool()
+ })
+}
+
+impl<'tcx> LateLintPass<'tcx> for BoolAssertComparison {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ let Some(macro_call) = root_macro_call_first_node(cx, expr) else { return };
+ let macro_name = cx.tcx.item_name(macro_call.def_id);
+ if !matches!(
+ macro_name.as_str(),
+ "assert_eq" | "debug_assert_eq" | "assert_ne" | "debug_assert_ne"
+ ) {
+ return;
+ }
+ let Some ((a, b, _)) = find_assert_eq_args(cx, expr, macro_call.expn) else { return };
+ if !(is_bool_lit(a) ^ is_bool_lit(b)) {
+ // If there are two boolean arguments, we definitely don't understand
+ // what's going on, so better leave things as is...
+ //
+ // Or there is simply no boolean and then we can leave things as is!
+ return;
+ }
+
+ if !is_impl_not_trait_with_bool_out(cx, a) || !is_impl_not_trait_with_bool_out(cx, b) {
+ // At this point the expression which is not a boolean
+ // literal does not implement Not trait with a bool output,
+ // so we cannot suggest to rewrite our code
+ return;
+ }
+
+ let macro_name = macro_name.as_str();
+ let non_eq_mac = ¯o_name[..macro_name.len() - 3];
+ span_lint_and_sugg(
+ cx,
+ BOOL_ASSERT_COMPARISON,
+ macro_call.span,
+ &format!("used `{}!` with a literal bool", macro_name),
+ "replace it with",
+ format!("{}!(..)", non_eq_mac),
+ Applicability::MaybeIncorrect,
+ );
+ }
+}
--- /dev/null
- /// false negative on such code:
+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
- /// // Bad
++ /// 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
++ /// fn foo(_x: &str) {}
++ ///
+ /// let s = &String::new();
+ ///
- /// // Good
+ /// let a: &String = &* s;
+ /// foo(&*s);
++ /// ```
+ ///
- ///
- /// fn foo(_: &str){ }
++ /// Use instead:
++ /// ```rust
++ /// # fn foo(_x: &str) {}
++ /// # let s = &String::new();
+ /// let a: &String = s;
+ /// foo(&**s);
+ /// ```
+ #[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
- /// // Bad
+mod cast_abs_to_unsigned;
+mod cast_enum_constructor;
+mod cast_lossless;
+mod cast_possible_truncation;
+mod cast_possible_wrap;
+mod cast_precision_loss;
+mod cast_ptr_alignment;
+mod cast_ref_to_mut;
+mod cast_sign_loss;
+mod cast_slice_different_sizes;
+mod char_lit_as_u8;
+mod fn_to_numeric_cast;
+mod fn_to_numeric_cast_any;
+mod fn_to_numeric_cast_with_truncation;
+mod ptr_as_ptr;
+mod unnecessary_cast;
+mod utils;
+
+use clippy_utils::is_hir_ty_cfg_dependant;
+use rustc_hir::{Expr, ExprKind};
+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 casts from any numerical to a float type where
+ /// the receiving type cannot store all values from the original type without
+ /// rounding errors. This possible rounding is to be expected, so this lint is
+ /// `Allow` by default.
+ ///
+ /// Basically, this warns on casting any integer with 32 or more bits to `f32`
+ /// or any 64-bit integer to `f64`.
+ ///
+ /// ### Why is this bad?
+ /// It's not bad at all. But in some applications it can be
+ /// helpful to know where precision loss can take place. This lint can help find
+ /// those places in the code.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = u64::MAX;
+ /// x as f64;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CAST_PRECISION_LOSS,
+ pedantic,
+ "casts that cause loss of precision, e.g., `x as f32` where `x: u64`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts from a signed to an unsigned numerical
+ /// type. In this case, negative values wrap around to large positive values,
+ /// which can be quite surprising in practice. However, as the cast works as
+ /// defined, this lint is `Allow` by default.
+ ///
+ /// ### Why is this bad?
+ /// Possibly surprising results. You can activate this lint
+ /// as a one-time check to see where numerical wrapping can arise.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let y: i8 = -1;
+ /// y as u128; // will return 18446744073709551615
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CAST_SIGN_LOSS,
+ pedantic,
+ "casts from signed types to unsigned types, e.g., `x as u32` where `x: i32`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts between numerical types that may
+ /// truncate large values. This is expected behavior, so the cast is `Allow` by
+ /// default.
+ ///
+ /// ### Why is this bad?
+ /// In some problem domains, it is good practice to avoid
+ /// truncation. This lint can be activated to help assess where additional
+ /// checks could be beneficial.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn as_u8(x: u64) -> u8 {
+ /// x as u8
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CAST_POSSIBLE_TRUNCATION,
+ pedantic,
+ "casts that may cause truncation of the value, e.g., `x as u8` where `x: u32`, or `x as i32` where `x: f32`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts from an unsigned type to a signed type of
+ /// the same size. Performing such a cast is a 'no-op' for the compiler,
+ /// i.e., nothing is changed at the bit level, and the binary representation of
+ /// the value is reinterpreted. This can cause wrapping if the value is too big
+ /// for the target signed type. However, the cast works as defined, so this lint
+ /// is `Allow` by default.
+ ///
+ /// ### Why is this bad?
+ /// While such a cast is not bad in itself, the results can
+ /// be surprising when this is not the intended behavior, as demonstrated by the
+ /// example below.
+ ///
+ /// ### Example
+ /// ```rust
+ /// u32::MAX as i32; // will yield a value of `-1`
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CAST_POSSIBLE_WRAP,
+ pedantic,
+ "casts that may cause wrapping around the value, e.g., `x as i32` where `x: u32` and `x > i32::MAX`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts between numerical types that may
+ /// be replaced by safe conversion functions.
+ ///
+ /// ### Why is this bad?
+ /// Rust's `as` keyword will perform many kinds of
+ /// conversions, including silently lossy conversions. Conversion functions such
+ /// as `i32::from` will only perform lossless conversions. Using the conversion
+ /// functions prevents conversions from turning into silent lossy conversions if
+ /// the types of the input expressions ever change, and make it easier for
+ /// people reading the code to know that the conversion is lossless.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn as_u64(x: u8) -> u64 {
+ /// x as u64
+ /// }
+ /// ```
+ ///
+ /// Using `::from` would look like this:
+ ///
+ /// ```rust
+ /// fn as_u64(x: u8) -> u64 {
+ /// u64::from(x)
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CAST_LOSSLESS,
+ pedantic,
+ "casts using `as` that are known to be lossless, e.g., `x as u64` where `x: u8`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts to the same type, casts of int literals to integer types
+ /// and casts of float literals to float types.
+ ///
+ /// ### Why is this bad?
+ /// It's just unnecessary.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let _ = 2i32 as i32;
+ /// let _ = 0.5 as f32;
+ /// ```
+ ///
+ /// Better:
+ ///
+ /// ```rust
+ /// let _ = 2_i32;
+ /// let _ = 0.5_f32;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub UNNECESSARY_CAST,
+ complexity,
+ "cast to the same type, e.g., `x as i32` where `x: i32`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts, using `as` or `pointer::cast`,
+ /// from a less-strictly-aligned pointer to a more-strictly-aligned pointer
+ ///
+ /// ### Why is this bad?
+ /// Dereferencing the resulting pointer may be undefined
+ /// behavior.
+ ///
+ /// ### Known problems
+ /// Using `std::ptr::read_unaligned` and `std::ptr::write_unaligned` or similar
+ /// on the resulting pointer is fine. Is over-zealous: Casts with manual alignment checks or casts like
+ /// u64-> u8 -> u16 can be fine. Miri is able to do a more in-depth analysis.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let _ = (&1u8 as *const u8) as *const u16;
+ /// let _ = (&mut 1u8 as *mut u8) as *mut u16;
+ ///
+ /// (&1u8 as *const u8).cast::<u16>();
+ /// (&mut 1u8 as *mut u8).cast::<u16>();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CAST_PTR_ALIGNMENT,
+ pedantic,
+ "cast from a pointer to a more-strictly-aligned pointer"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts of function pointers to something other than usize
+ ///
+ /// ### Why is this bad?
+ /// Casting a function pointer to anything other than usize/isize is not portable across
+ /// architectures, because you end up losing bits if the target type is too small or end up with a
+ /// bunch of extra bits that waste space and add more instructions to the final binary than
+ /// strictly necessary for the problem
+ ///
+ /// Casting to isize also doesn't make sense since there are no signed addresses.
+ ///
+ /// ### Example
+ /// ```rust
- /// let a = fun as i64;
+ /// fn fun() -> i32 { 1 }
- /// // Good
- /// fn fun2() -> i32 { 1 }
- /// let a = fun2 as usize;
++ /// let _ = fun as i64;
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # fn fun() -> i32 { 1 }
++ /// let _ = fun as usize;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub FN_TO_NUMERIC_CAST,
+ style,
+ "casting a function pointer to a numeric type other than usize"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts of a function pointer to a numeric type not wide enough to
+ /// store address.
+ ///
+ /// ### Why is this bad?
+ /// Such a cast discards some bits of the function's address. If this is intended, it would be more
+ /// clearly expressed by casting to usize first, then casting the usize to the intended type (with
+ /// a comment) to perform the truncation.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Better: Cast to usize first, then comment with the reason for the truncation
- /// fn fn2() -> i16 {
+ /// fn fn1() -> i16 {
+ /// 1
+ /// };
+ /// let _ = fn1 as i32;
++ /// ```
+ ///
- /// let fn_ptr = fn2 as usize;
++ /// Use instead:
++ /// ```rust
++ /// // Cast to usize first, then comment with the reason for the truncation
++ /// fn fn1() -> i16 {
+ /// 1
+ /// };
- /// // Bad: fn1 is cast as `usize`
++ /// let fn_ptr = fn1 as usize;
+ /// let fn_ptr_truncated = fn_ptr as i32;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub FN_TO_NUMERIC_CAST_WITH_TRUNCATION,
+ style,
+ "casting a function pointer to a numeric type not wide enough to store the address"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts of a function pointer to any integer type.
+ ///
+ /// ### Why is this bad?
+ /// Casting a function pointer to an integer can have surprising results and can occur
+ /// accidentally if parentheses are omitted from a function call. If you aren't doing anything
+ /// low-level with function pointers then you can opt-out of casting functions to integers in
+ /// order to avoid mistakes. Alternatively, you can use this lint to audit all uses of function
+ /// pointer casts in your code.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good: maybe you intended to call the function?
++ /// // fn1 is cast as `usize`
+ /// fn fn1() -> u16 {
+ /// 1
+ /// };
+ /// let _ = fn1 as usize;
++ /// ```
+ ///
- /// // Good: maybe you intended to cast it to a function type?
++ /// Use instead:
++ /// ```rust
++ /// // maybe you intended to call the function?
+ /// fn fn2() -> u16 {
+ /// 1
+ /// };
+ /// let _ = fn2() as usize;
+ ///
- #[clippy::version = "1.60.0"]
++ /// // or
++ ///
++ /// // maybe you intended to cast it to a function type?
+ /// fn fn3() -> u16 {
+ /// 1
+ /// }
+ /// let _ = fn3 as fn() -> u16;
+ /// ```
+ #[clippy::version = "1.58.0"]
+ pub FN_TO_NUMERIC_CAST_ANY,
+ restriction,
+ "casting a function pointer to any integer type"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts of `&T` to `&mut T` anywhere in the code.
+ ///
+ /// ### Why is this bad?
+ /// It’s basically guaranteed to be undefined behavior.
+ /// `UnsafeCell` is the only way to obtain aliasable data that is considered
+ /// mutable.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// fn x(r: &i32) {
+ /// unsafe {
+ /// *(r as *const _ as *mut _) += 1;
+ /// }
+ /// }
+ /// ```
+ ///
+ /// Instead consider using interior mutability types.
+ ///
+ /// ```rust
+ /// use std::cell::UnsafeCell;
+ ///
+ /// fn x(r: &UnsafeCell<i32>) {
+ /// unsafe {
+ /// *r.get() += 1;
+ /// }
+ /// }
+ /// ```
+ #[clippy::version = "1.33.0"]
+ pub CAST_REF_TO_MUT,
+ correctness,
+ "a cast of reference to a mutable pointer"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for expressions where a character literal is cast
+ /// to `u8` and suggests using a byte literal instead.
+ ///
+ /// ### Why is this bad?
+ /// In general, casting values to smaller types is
+ /// error-prone and should be avoided where possible. In the particular case of
+ /// converting a character literal to u8, it is easy to avoid by just using a
+ /// byte literal instead. As an added bonus, `b'a'` is even slightly shorter
+ /// than `'a' as u8`.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// 'x' as u8
+ /// ```
+ ///
+ /// A better version, using the byte literal:
+ ///
+ /// ```rust,ignore
+ /// b'x'
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CHAR_LIT_AS_U8,
+ complexity,
+ "casting a character literal to `u8` truncates"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `as` casts between raw pointers without changing its mutability,
+ /// namely `*const T` to `*const U` and `*mut T` to `*mut U`.
+ ///
+ /// ### Why is this bad?
+ /// Though `as` casts between raw pointers is not terrible, `pointer::cast` is safer because
+ /// it cannot accidentally change the pointer's mutability nor cast the pointer to other types like `usize`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let ptr: *const u32 = &42_u32;
+ /// let mut_ptr: *mut u32 = &mut 42_u32;
+ /// let _ = ptr as *const i32;
+ /// let _ = mut_ptr as *mut i32;
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let ptr: *const u32 = &42_u32;
+ /// let mut_ptr: *mut u32 = &mut 42_u32;
+ /// let _ = ptr.cast::<i32>();
+ /// let _ = mut_ptr.cast::<i32>();
+ /// ```
+ #[clippy::version = "1.51.0"]
+ pub PTR_AS_PTR,
+ pedantic,
+ "casting using `as` from and to raw pointers that doesn't change its mutability, where `pointer::cast` could take the place of `as`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts from an enum type to an integral type which will definitely truncate the
+ /// value.
+ ///
+ /// ### Why is this bad?
+ /// The resulting integral value will not match the value of the variant it came from.
+ ///
+ /// ### Example
+ /// ```rust
+ /// enum E { X = 256 };
+ /// let _ = E::X as u8;
+ /// ```
- #[clippy::version = "1.60.0"]
++ #[clippy::version = "1.61.0"]
+ pub CAST_ENUM_TRUNCATION,
+ suspicious,
+ "casts from an enum type to an integral type which will truncate the value"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `as` casts between raw pointers to slices with differently sized elements.
+ ///
+ /// ### Why is this bad?
+ /// The produced raw pointer to a slice does not update its length metadata. The produced
+ /// pointer will point to a different number of bytes than the original pointer because the
+ /// length metadata of a raw slice pointer is in elements rather than bytes.
+ /// Producing a slice reference from the raw pointer will either create a slice with
+ /// less data (which can be surprising) or create a slice with more data and cause Undefined Behavior.
+ ///
+ /// ### Example
+ /// // Missing data
+ /// ```rust
+ /// let a = [1_i32, 2, 3, 4];
+ /// let p = &a as *const [i32] as *const [u8];
+ /// unsafe {
+ /// println!("{:?}", &*p);
+ /// }
+ /// ```
+ /// // Undefined Behavior (note: also potential alignment issues)
+ /// ```rust
+ /// let a = [1_u8, 2, 3, 4];
+ /// let p = &a as *const [u8] as *const [u32];
+ /// unsafe {
+ /// println!("{:?}", &*p);
+ /// }
+ /// ```
+ /// Instead use `ptr::slice_from_raw_parts` to construct a slice from a data pointer and the correct length
+ /// ```rust
+ /// let a = [1_i32, 2, 3, 4];
+ /// let old_ptr = &a as *const [i32];
+ /// // The data pointer is cast to a pointer to the target `u8` not `[u8]`
+ /// // The length comes from the known length of 4 i32s times the 4 bytes per i32
+ /// let new_ptr = core::ptr::slice_from_raw_parts(old_ptr as *const u8, 16);
+ /// unsafe {
+ /// println!("{:?}", &*new_ptr);
+ /// }
+ /// ```
++ #[clippy::version = "1.61.0"]
+ pub CAST_SLICE_DIFFERENT_SIZES,
+ correctness,
+ "casting using `as` between raw pointers to slices of types with different sizes"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for casts from an enum tuple constructor to an integer.
+ ///
+ /// ### Why is this bad?
+ /// The cast is easily confused with casting a c-like enum value to an integer.
+ ///
+ /// ### Example
+ /// ```rust
+ /// enum E { X(i32) };
+ /// let _ = E::X as usize;
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub CAST_ENUM_CONSTRUCTOR,
+ suspicious,
+ "casts from an enum tuple constructor to an integer"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for uses of the `abs()` method that cast the result to unsigned.
+ ///
+ /// ### Why is this bad?
+ /// The `unsigned_abs()` method avoids panic when called on the MIN value.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x: i32 = -42;
+ /// let y: u32 = x.abs() as u32;
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let x: i32 = -42;
+ /// let y: u32 = x.unsigned_abs();
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub CAST_ABS_TO_UNSIGNED,
+ suspicious,
+ "casting the result of `abs()` to an unsigned integer can panic"
+}
+
+pub struct Casts {
+ msrv: Option<RustcVersion>,
+}
+
+impl Casts {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self { msrv }
+ }
+}
+
+impl_lint_pass!(Casts => [
+ CAST_PRECISION_LOSS,
+ CAST_SIGN_LOSS,
+ CAST_POSSIBLE_TRUNCATION,
+ CAST_POSSIBLE_WRAP,
+ CAST_LOSSLESS,
+ CAST_REF_TO_MUT,
+ CAST_PTR_ALIGNMENT,
+ CAST_SLICE_DIFFERENT_SIZES,
+ UNNECESSARY_CAST,
+ FN_TO_NUMERIC_CAST_ANY,
+ FN_TO_NUMERIC_CAST,
+ FN_TO_NUMERIC_CAST_WITH_TRUNCATION,
+ CHAR_LIT_AS_U8,
+ PTR_AS_PTR,
+ CAST_ENUM_TRUNCATION,
+ CAST_ENUM_CONSTRUCTOR,
+ CAST_ABS_TO_UNSIGNED
+]);
+
+impl<'tcx> LateLintPass<'tcx> for Casts {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if !in_external_macro(cx.sess(), expr.span) {
+ ptr_as_ptr::check(cx, expr, self.msrv);
+ }
+
+ if expr.span.from_expansion() {
+ return;
+ }
+
+ if let ExprKind::Cast(cast_expr, cast_to) = expr.kind {
+ if is_hir_ty_cfg_dependant(cx, cast_to) {
+ return;
+ }
+ let (cast_from, cast_to) = (
+ cx.typeck_results().expr_ty(cast_expr),
+ cx.typeck_results().expr_ty(expr),
+ );
+
+ if unnecessary_cast::check(cx, expr, cast_expr, cast_from, cast_to) {
+ return;
+ }
+
+ fn_to_numeric_cast_any::check(cx, expr, cast_expr, cast_from, cast_to);
+ fn_to_numeric_cast::check(cx, expr, cast_expr, cast_from, cast_to);
+ fn_to_numeric_cast_with_truncation::check(cx, expr, cast_expr, cast_from, cast_to);
+
+ if cast_to.is_numeric() && !in_external_macro(cx.sess(), expr.span) {
+ cast_possible_truncation::check(cx, expr, cast_expr, cast_from, cast_to);
+ if cast_from.is_numeric() {
+ cast_possible_wrap::check(cx, expr, cast_from, cast_to);
+ cast_precision_loss::check(cx, expr, cast_from, cast_to);
+ cast_sign_loss::check(cx, expr, cast_expr, cast_from, cast_to);
+ cast_abs_to_unsigned::check(cx, expr, cast_expr, cast_from, cast_to, self.msrv);
+ }
+ cast_lossless::check(cx, expr, cast_expr, cast_from, cast_to, self.msrv);
+ cast_enum_constructor::check(cx, expr, cast_expr, cast_from);
+ }
+ }
+
+ cast_ref_to_mut::check(cx, expr);
+ cast_ptr_alignment::check(cx, expr);
+ char_lit_as_u8::check(cx, expr);
+ ptr_as_ptr::check(cx, expr, self.msrv);
+ cast_slice_different_sizes::check(cx, expr, self.msrv);
+ }
+
+ extract_msrv_attr!(LateContext);
+}
--- /dev/null
- use clippy_utils::{meets_msrv, msrvs, SpanlessEq};
+//! 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;
- /// # let _ =
- /// foo <= i32::MAX as u32
- /// # ;
++use clippy_utils::{in_constant, 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;
- /// Could be written:
- ///
++ /// foo <= i32::MAX as u32;
+ /// ```
+ ///
- /// # let _ =
- /// i32::try_from(foo).is_ok()
- /// # ;
++ /// Use instead:
+ /// ```rust
+ /// # let foo = 1;
++ /// # #[allow(unused)]
++ /// 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_constant(cx, item.hir_id);
+ 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 [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
- /// ```rust,ignore
+//! 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
++ /// # let (x, y) = (true, true);
+ /// if x {
+ /// if y {
- ///
++ /// // …
+ /// }
+ /// }
- ///
- /// ```rust,ignore
+ /// ```
+ ///
+ /// Use instead:
- /// …
++ /// ```rust
++ /// # let (x, y) = (true, true);
+ /// 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
- ///
+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
- 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 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::{
- 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;
++ eq_expr_value, get_enclosing_block, hash_expr, hash_stmt, if_sequence, is_else_clause, is_lint_allowed,
++ search_same, ContainsName, HirEqInterExpr, SpanlessEq,
+};
- use rustc_span::{source_map::Span, symbol::Symbol, BytePos};
++use core::iter;
++use rustc_errors::Applicability;
++use rustc_hir::intravisit;
++use rustc_hir::{BinOpKind, Block, Expr, ExprKind, HirId, Stmt, StmtKind};
++use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
- 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);
++use rustc_span::hygiene::walk_chain;
++use rustc_span::source_map::SourceMap;
++use rustc_span::{BytePos, Span, Symbol};
+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<'_>) {
- /// Implementation of `BRANCHES_SHARING_CODE` and `IF_SAME_THEN_ELSE` if the blocks are equal.
- fn lint_same_then_else<'tcx>(
++ if !expr.span.from_expansion() && matches!(expr.kind, ExprKind::If(..)) && !is_else_clause(cx.tcx, expr) {
++ let (conds, blocks) = if_sequence(expr);
++ lint_same_cond(cx, &conds);
++ lint_same_fns_in_if_cond(cx, &conds);
++ let all_same =
++ !is_lint_allowed(cx, IF_SAME_THEN_ELSE, expr.hir_id) && lint_if_same_then_else(cx, &conds, &blocks);
++ if !all_same && conds.len() != blocks.len() {
++ lint_branches_sharing_code(cx, &conds, &blocks, expr);
+ }
+ }
+ }
+}
+
- has_conditional_else: bool,
++/// Checks if the given expression is a let chain.
++fn contains_let(e: &Expr<'_>) -> bool {
++ match e.kind {
++ ExprKind::Let(..) => true,
++ ExprKind::Binary(op, lhs, rhs) if op.node == BinOpKind::And => {
++ matches!(lhs.kind, ExprKind::Let(..)) || contains_let(rhs)
++ },
++ _ => false,
++ }
++}
++
++fn lint_if_same_then_else(cx: &LateContext<'_>, conds: &[&Expr<'_>], blocks: &[&Block<'_>]) -> bool {
++ let mut eq = SpanlessEq::new(cx);
++ blocks
++ .array_windows::<2>()
++ .enumerate()
++ .fold(true, |all_eq, (i, &[lhs, rhs])| {
++ if eq.eq_block(lhs, rhs) && !contains_let(conds[i]) && conds.get(i + 1).map_or(true, |e| !contains_let(e)) {
++ span_lint_and_note(
++ cx,
++ IF_SAME_THEN_ELSE,
++ lhs.span,
++ "this `if` has identical blocks",
++ Some(rhs.span),
++ "same as this",
++ );
++ all_eq
++ } else {
++ false
++ }
++ })
++}
++
++fn lint_branches_sharing_code<'tcx>(
+ cx: &LateContext<'tcx>,
+ conds: &[&'tcx Expr<'_>],
+ blocks: &[&Block<'tcx>],
- 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 {
+ expr: &'tcx Expr<'_>,
+) {
+ // We only lint ifs with multiple blocks
-
- // BRANCHES_SHARING_CODE prerequisites
- if has_conditional_else || (start_eq == 0 && end_eq == 0 && (has_expr && !expr_eq)) {
++ let &[first_block, ref blocks @ ..] = blocks else {
+ 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);
- }
++ let &[.., last_block] = blocks else {
+ return;
- 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 res = scan_block_for_eq(cx, conds, first_block, blocks);
++ let sm = cx.tcx.sess.source_map();
++ let start_suggestion = res.start_span(first_block, sm).map(|span| {
++ let first_line_span = first_line_of_span(cx, expr.span);
++ let replace_span = first_line_span.with_hi(span.hi());
++ let cond_span = first_line_span.until(first_block.span);
++ let cond_snippet = reindent_multiline(snippet(cx, cond_span, "_"), false, None);
++ let cond_indent = indent_of(cx, cond_span);
++ let moved_snippet = reindent_multiline(snippet(cx, span, "_"), true, None);
++ let suggestion = moved_snippet.to_string() + "\n" + &cond_snippet + "{";
++ let suggestion = reindent_multiline(Cow::Borrowed(&suggestion), true, cond_indent);
++ (replace_span, suggestion.to_string())
++ });
++ let end_suggestion = res.end_span(last_block, sm).map(|span| {
++ let moved_snipped = reindent_multiline(snippet(cx, span, "_"), true, None);
++ let indent = indent_of(cx, expr.span.shrink_to_hi());
++ let suggestion = "}\n".to_string() + &moved_snipped;
++ let suggestion = reindent_multiline(Cow::Borrowed(&suggestion), true, indent);
+
- 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 span = span.with_hi(last_block.span.hi());
++ // 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());
++ let span = if snippet_opt(cx, test_span).map_or(false, |snip| snip == " ") {
++ span.with_lo(test_span.lo())
++ } else {
++ span
++ };
++ (span, suggestion.to_string())
++ });
++
++ let (span, msg, end_span) = match (&start_suggestion, &end_suggestion) {
++ (&Some((span, _)), &Some((end_span, _))) => (
++ span,
++ "all if blocks contain the same code at both the start and the end",
++ Some(end_span),
++ ),
++ (&Some((span, _)), None) => (span, "all if blocks contain the same code at the start", None),
++ (None, &Some((span, _))) => (span, "all if blocks contain the same code at the end", None),
++ (None, None) => return,
++ };
++ span_lint_and_then(cx, BRANCHES_SHARING_CODE, span, msg, |diag| {
++ if let Some(span) = end_span {
++ diag.span_note(span, "this code is shared at the end");
+ }
- 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();
- }
++ if let Some((span, sugg)) = start_suggestion {
++ diag.span_suggestion(
++ span,
++ "consider moving these statements before the if",
++ sugg,
++ Applicability::Unspecified,
++ );
+ }
-
- end_walker.uses.clear();
++ if let Some((span, sugg)) = end_suggestion {
++ diag.span_suggestion(
++ span,
++ "consider moving these statements after the if",
++ sugg,
++ Applicability::Unspecified,
++ );
++ if !cx.typeck_results().expr_ty(expr).is_unit() {
++ diag.note("the end suggestion probably needs some adjustments to use the expression result correctly");
+ }
-
- 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);
- });
++ if check_for_warn_of_moved_symbol(cx, &res.moved_locals, expr) {
++ diag.warn("some moved values might need to be renamed to avoid wrong references");
+ }
++ });
++}
+
- 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 BlockEq {
++ /// The end of the range of equal stmts at the start.
++ start_end_eq: usize,
++ /// The start of the range of equal stmts at the end.
++ end_begin_eq: Option<usize>,
++ /// The name and id of every local which can be moved at the beginning and the end.
++ moved_locals: Vec<(HirId, Symbol)>,
++}
++impl BlockEq {
++ fn start_span(&self, b: &Block<'_>, sm: &SourceMap) -> Option<Span> {
++ match &b.stmts[..self.start_end_eq] {
++ [first, .., last] => Some(sm.stmt_span(first.span, b.span).to(sm.stmt_span(last.span, b.span))),
++ [s] => Some(sm.stmt_span(s.span, b.span)),
++ [] => None,
+ }
++ }
+
- 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,
++ fn end_span(&self, b: &Block<'_>, sm: &SourceMap) -> Option<Span> {
++ match (&b.stmts[b.stmts.len() - self.end_begin_eq?..], b.expr) {
++ ([first, .., last], None) => Some(sm.stmt_span(first.span, b.span).to(sm.stmt_span(last.span, b.span))),
++ ([first, ..], Some(last)) => Some(sm.stmt_span(first.span, b.span).to(sm.stmt_span(last.span, b.span))),
++ ([s], None) => Some(sm.stmt_span(s.span, b.span)),
++ ([], Some(e)) => Some(walk_chain(e.span, b.span.ctxt())),
++ ([], None) => None,
++ }
+ }
+}
+
- /// 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));
++/// If the statement is a local, checks if the bound names match the expected list of names.
++fn eq_binding_names(s: &Stmt<'_>, names: &[(HirId, Symbol)]) -> bool {
++ if let StmtKind::Local(l) = s.kind {
++ let mut i = 0usize;
++ let mut res = true;
++ l.pat.each_binding_or_first(&mut |_, _, _, name| {
++ if names.get(i).map_or(false, |&(_, n)| n == name.name) {
++ i += 1;
++ } else {
++ res = false;
++ }
++ });
++ res && i == names.len()
++ } else {
++ false
++ }
+}
+
- 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 })
++/// Checks if the given statement should be considered equal to the statement in the same position
++/// for each block.
++fn eq_stmts(
++ stmt: &Stmt<'_>,
++ blocks: &[&Block<'_>],
++ get_stmt: impl for<'a> Fn(&'a Block<'a>) -> Option<&'a Stmt<'a>>,
++ eq: &mut HirEqInterExpr<'_, '_, '_>,
++ moved_bindings: &mut Vec<(HirId, Symbol)>,
++) -> bool {
++ (if let StmtKind::Local(l) = stmt.kind {
++ let old_count = moved_bindings.len();
++ l.pat.each_binding_or_first(&mut |_, id, _, name| {
++ moved_bindings.push((id, name.name));
++ });
++ let new_bindings = &moved_bindings[old_count..];
++ blocks
++ .iter()
++ .all(|b| get_stmt(b).map_or(false, |s| eq_binding_names(s, new_bindings)))
++ } else {
++ true
++ }) && blocks
++ .iter()
++ .all(|b| get_stmt(b).map_or(false, |s| eq.eq_stmt(s, stmt)))
++}
+
- 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;
++fn scan_block_for_eq(cx: &LateContext<'_>, _conds: &[&Expr<'_>], block: &Block<'_>, blocks: &[&Block<'_>]) -> BlockEq {
++ let mut eq = SpanlessEq::new(cx);
++ let mut eq = eq.inter_expr();
++ let mut moved_locals = Vec::new();
++
++ let start_end_eq = block
++ .stmts
++ .iter()
++ .enumerate()
++ .find(|&(i, stmt)| !eq_stmts(stmt, blocks, |b| b.stmts.get(i), &mut eq, &mut moved_locals))
++ .map_or(block.stmts.len(), |(i, _)| i);
++
++ // Walk backwards through the final expression/statements so long as their hashes are equal. Note
++ // `SpanlessHash` treats all local references as equal allowing locals declared earlier in the block
++ // to match those in other blocks. e.g. If each block ends with the following the hash value will be
++ // the same even though each `x` binding will have a different `HirId`:
++ // let x = foo();
++ // x + 50
++ let expr_hash_eq = if let Some(e) = block.expr {
++ let hash = hash_expr(cx, e);
++ blocks
++ .iter()
++ .all(|b| b.expr.map_or(false, |e| hash_expr(cx, e) == hash))
++ } else {
++ blocks.iter().all(|b| b.expr.is_none())
++ };
++ if !expr_hash_eq {
++ return BlockEq {
++ start_end_eq,
++ end_begin_eq: None,
++ moved_locals,
+ };
-
- 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;
++ }
++ let end_search_start = block.stmts[start_end_eq..]
++ .iter()
++ .rev()
++ .enumerate()
++ .find(|&(offset, stmt)| {
++ let hash = hash_stmt(cx, stmt);
++ blocks.iter().any(|b| {
++ b.stmts
++ // the bounds check will catch the underflow
++ .get(b.stmts.len().wrapping_sub(offset + 1))
++ .map_or(true, |s| hash != hash_stmt(cx, s))
++ })
++ })
++ .map_or(block.stmts.len() - start_end_eq, |(i, _)| i);
++
++ let moved_locals_at_start = moved_locals.len();
++ let mut i = end_search_start;
++ let end_begin_eq = block.stmts[block.stmts.len() - end_search_start..]
++ .iter()
++ .zip(iter::repeat_with(move || {
++ let x = i;
++ i -= 1;
++ x
++ }))
++ .fold(end_search_start, |init, (stmt, offset)| {
++ if eq_stmts(
++ stmt,
++ blocks,
++ |b| b.stmts.get(b.stmts.len() - offset),
++ &mut eq,
++ &mut moved_locals,
++ ) {
++ init
++ } else {
++ // Clear out all locals seen at the end so far. None of them can be moved.
++ let stmts = &blocks[0].stmts;
++ for stmt in &stmts[stmts.len() - init..=stmts.len() - offset] {
++ if let StmtKind::Local(l) = stmt.kind {
++ l.pat.each_binding_or_first(&mut |_, id, _, _| {
++ eq.locals.remove(&id);
++ });
++ }
++ }
++ moved_locals.truncate(moved_locals_at_start);
++ offset - 1
++ }
++ });
++ if let Some(e) = block.expr {
++ for block in blocks {
++ if block.expr.map_or(false, |expr| !eq.eq_expr(expr, e)) {
++ moved_locals.truncate(moved_locals_at_start);
++ return BlockEq {
++ start_end_eq,
++ end_begin_eq: None,
++ moved_locals,
++ };
+ }
+ }
- // 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,
- })
++ BlockEq {
++ start_end_eq,
++ end_begin_eq: Some(end_begin_eq),
++ moved_locals,
+ }
- fn check_for_warn_of_moved_symbol(cx: &LateContext<'_>, symbols: &FxHashSet<Symbol>, if_expr: &Expr<'_>) -> bool {
+}
+
- .filter(|sym| !sym.as_str().starts_with('_'))
- .any(move |sym| {
- let mut walker = ContainsName {
- name: *sym,
- result: false,
- };
++fn check_for_warn_of_moved_symbol(cx: &LateContext<'_>, symbols: &[(HirId, 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()
- 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);
- }
- }
- }
- }
- }
-
++ .filter(|&&(_, name)| !name.as_str().starts_with('_'))
++ .any(|&(_, name)| {
++ let mut walker = ContainsName { name, 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
+ })
+ })
+}
+
- 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) {
+/// 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()
- };
-
++ for (i, j) in search_same(conds, |e| hash_expr(cx, e), |lhs, rhs| eq_expr_value(cx, lhs, rhs)) {
+ 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<'_>]) {
- for (i, j) in search_same(conds, hash, eq) {
+ 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, |e| hash_expr(cx, e), 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
- ///
- /// ```rust
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet;
+use clippy_utils::{match_def_path, paths};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks usage of `std::fs::create_dir` and suggest using `std::fs::create_dir_all` instead.
+ ///
+ /// ### Why is this bad?
+ /// Sometimes `std::fs::create_dir` is mistakenly chosen over `std::fs::create_dir_all`.
+ ///
+ /// ### Example
- /// ```rust
++ /// ```rust,ignore
+ /// std::fs::create_dir("foo");
+ /// ```
++ ///
+ /// Use instead:
++ /// ```rust,ignore
+ /// std::fs::create_dir_all("foo");
+ /// ```
+ #[clippy::version = "1.48.0"]
+ pub CREATE_DIR,
+ restriction,
+ "calling `std::fs::create_dir` instead of `std::fs::create_dir_all`"
+}
+
+declare_lint_pass!(CreateDir => [CREATE_DIR]);
+
+impl LateLintPass<'_> for CreateDir {
+ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Call(func, args) = expr.kind;
+ if let ExprKind::Path(ref path) = func.kind;
+ if let Some(def_id) = cx.qpath_res(path, func.hir_id).opt_def_id();
+ if match_def_path(cx, def_id, &paths::STD_FS_CREATE_DIR);
+ then {
+ span_lint_and_sugg(
+ cx,
+ CREATE_DIR,
+ expr.span,
+ "calling `std::fs::create_dir` where there may be a better way",
+ "consider calling `std::fs::create_dir_all` instead",
+ format!("create_dir_all({})", snippet(cx, args[0].span, "..")),
+ Applicability::MaybeIncorrect,
+ )
+ }
+ }
+ }
+}
--- /dev/null
- /// // Bad
+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};
+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
- /// // Good
+ /// dbg!(true)
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust,ignore
+ /// true
+ /// ```
+ #[clippy::version = "1.34.0"]
+ pub DBG_MACRO,
+ restriction,
+ "`dbg!` macro is intended as a debugging tool"
+}
+
+#[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
- /// It's more clear to the reader to use the name of the type whose default is
- /// being gotten than the generic `Default`.
+use clippy_utils::diagnostics::{span_lint_and_note, span_lint_and_sugg};
+use clippy_utils::source::snippet_with_macro_callsite;
+use clippy_utils::ty::{has_drop, is_copy};
+use clippy_utils::{any_parent_is_automatically_derived, contains_name, get_parent_expr, match_def_path, paths};
+use if_chain::if_chain;
+use rustc_data_structures::fx::FxHashSet;
+use rustc_errors::Applicability;
+use rustc_hir::def::Res;
+use rustc_hir::{Block, Expr, ExprKind, PatKind, QPath, Stmt, StmtKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::symbol::{Ident, Symbol};
+use rustc_span::Span;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for literal calls to `Default::default()`.
+ ///
+ /// ### Why is this bad?
- /// // Bad
++ /// It's easier for the reader if the name of the type is used, rather than the
++ /// generic `Default`.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// let s: String = Default::default();
++ /// ```
+ ///
- /// Bad:
++ /// Use instead:
++ /// ```rust
+ /// let s = String::default();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DEFAULT_TRAIT_ACCESS,
+ pedantic,
+ "checks for literal calls to `Default::default()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for immediate reassignment of fields initialized
+ /// with Default::default().
+ ///
+ /// ### Why is this bad?
+ ///It's more idiomatic to use the [functional update syntax](https://doc.rust-lang.org/reference/expressions/struct-expr.html#functional-update-syntax).
+ ///
+ /// ### Known problems
+ /// Assignments to patterns that are of tuple type are not linted.
+ ///
+ /// ### Example
+ /// ```
+ /// # #[derive(Default)]
+ /// # struct A { i: i32 }
+ /// let mut a: A = Default::default();
+ /// a.i = 42;
+ /// ```
++ ///
+ /// Use instead:
+ /// ```
+ /// # #[derive(Default)]
+ /// # struct A { i: i32 }
+ /// let a = A {
+ /// i: 42,
+ /// .. Default::default()
+ /// };
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub FIELD_REASSIGN_WITH_DEFAULT,
+ style,
+ "binding initialized with Default should have its fields set in the initializer"
+}
+
+#[derive(Default)]
+pub struct Default {
+ // Spans linted by `field_reassign_with_default`.
+ reassigned_linted: FxHashSet<Span>,
+}
+
+impl_lint_pass!(Default => [DEFAULT_TRAIT_ACCESS, FIELD_REASSIGN_WITH_DEFAULT]);
+
+impl<'tcx> LateLintPass<'tcx> for Default {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ if !expr.span.from_expansion();
+ // Avoid cases already linted by `field_reassign_with_default`
+ if !self.reassigned_linted.contains(&expr.span);
+ if let ExprKind::Call(path, ..) = expr.kind;
+ if !any_parent_is_automatically_derived(cx.tcx, expr.hir_id);
+ if let ExprKind::Path(ref qpath) = path.kind;
+ if let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id();
+ if match_def_path(cx, def_id, &paths::DEFAULT_TRAIT_METHOD);
+ if !is_update_syntax_base(cx, expr);
+ // Detect and ignore <Foo as Default>::default() because these calls do explicitly name the type.
+ if let QPath::Resolved(None, _path) = qpath;
+ let expr_ty = cx.typeck_results().expr_ty(expr);
+ if let ty::Adt(def, ..) = expr_ty.kind();
+ then {
+ // TODO: Work out a way to put "whatever the imported way of referencing
+ // this type in this file" rather than a fully-qualified type.
+ let replacement = format!("{}::default()", cx.tcx.def_path_str(def.did()));
+ span_lint_and_sugg(
+ cx,
+ DEFAULT_TRAIT_ACCESS,
+ expr.span,
+ &format!("calling `{}` is more clear than this expression", replacement),
+ "try",
+ replacement,
+ Applicability::Unspecified, // First resolve the TODO above
+ );
+ }
+ }
+ }
+
+ #[expect(clippy::too_many_lines)]
+ fn check_block(&mut self, cx: &LateContext<'tcx>, block: &Block<'tcx>) {
+ // start from the `let mut _ = _::default();` and look at all the following
+ // statements, see if they re-assign the fields of the binding
+ let stmts_head = match block.stmts {
+ // Skip the last statement since there cannot possibly be any following statements that re-assign fields.
+ [head @ .., _] if !head.is_empty() => head,
+ _ => return,
+ };
+ for (stmt_idx, stmt) in stmts_head.iter().enumerate() {
+ // find all binding statements like `let mut _ = T::default()` where `T::default()` is the
+ // `default` method of the `Default` trait, and store statement index in current block being
+ // checked and the name of the bound variable
+ let (local, variant, binding_name, binding_type, span) = if_chain! {
+ // only take `let ...` statements
+ if let StmtKind::Local(local) = stmt.kind;
+ if let Some(expr) = local.init;
+ if !any_parent_is_automatically_derived(cx.tcx, expr.hir_id);
+ if !expr.span.from_expansion();
+ // only take bindings to identifiers
+ if let PatKind::Binding(_, binding_id, ident, _) = local.pat.kind;
+ // only when assigning `... = Default::default()`
+ if is_expr_default(expr, cx);
+ let binding_type = cx.typeck_results().node_type(binding_id);
+ if let Some(adt) = binding_type.ty_adt_def();
+ if adt.is_struct();
+ let variant = adt.non_enum_variant();
+ if adt.did().is_local() || !variant.is_field_list_non_exhaustive();
+ let module_did = cx.tcx.parent_module(stmt.hir_id).to_def_id();
+ if variant
+ .fields
+ .iter()
+ .all(|field| field.vis.is_accessible_from(module_did, cx.tcx));
+ let all_fields_are_copy = variant
+ .fields
+ .iter()
+ .all(|field| {
+ is_copy(cx, cx.tcx.type_of(field.did))
+ });
+ if !has_drop(cx, binding_type) || all_fields_are_copy;
+ then {
+ (local, variant, ident.name, binding_type, expr.span)
+ } else {
+ continue;
+ }
+ };
+
+ // find all "later statement"'s where the fields of the binding set as
+ // Default::default() get reassigned, unless the reassignment refers to the original binding
+ let mut first_assign = None;
+ let mut assigned_fields = Vec::new();
+ let mut cancel_lint = false;
+ for consecutive_statement in &block.stmts[stmt_idx + 1..] {
+ // find out if and which field was set by this `consecutive_statement`
+ if let Some((field_ident, assign_rhs)) = field_reassigned_by_stmt(consecutive_statement, binding_name) {
+ // interrupt and cancel lint if assign_rhs references the original binding
+ if contains_name(binding_name, assign_rhs) {
+ cancel_lint = true;
+ break;
+ }
+
+ // if the field was previously assigned, replace the assignment, otherwise insert the assignment
+ if let Some(prev) = assigned_fields
+ .iter_mut()
+ .find(|(field_name, _)| field_name == &field_ident.name)
+ {
+ *prev = (field_ident.name, assign_rhs);
+ } else {
+ assigned_fields.push((field_ident.name, assign_rhs));
+ }
+
+ // also set first instance of error for help message
+ if first_assign.is_none() {
+ first_assign = Some(consecutive_statement);
+ }
+ }
+ // interrupt if no field was assigned, since we only want to look at consecutive statements
+ else {
+ break;
+ }
+ }
+
+ // if there are incorrectly assigned fields, do a span_lint_and_note to suggest
+ // construction using `Ty { fields, ..Default::default() }`
+ if !assigned_fields.is_empty() && !cancel_lint {
+ // if all fields of the struct are not assigned, add `.. Default::default()` to the suggestion.
+ let ext_with_default = !variant
+ .fields
+ .iter()
+ .all(|field| assigned_fields.iter().any(|(a, _)| a == &field.name));
+
+ let field_list = assigned_fields
+ .into_iter()
+ .map(|(field, rhs)| {
+ // extract and store the assigned value for help message
+ let value_snippet = snippet_with_macro_callsite(cx, rhs.span, "..");
+ format!("{}: {}", field, value_snippet)
+ })
+ .collect::<Vec<String>>()
+ .join(", ");
+
+ // give correct suggestion if generics are involved (see #6944)
+ let binding_type = if_chain! {
+ if let ty::Adt(adt_def, substs) = binding_type.kind();
+ if !substs.is_empty();
+ then {
+ let adt_def_ty_name = cx.tcx.item_name(adt_def.did());
+ let generic_args = substs.iter().collect::<Vec<_>>();
+ let tys_str = generic_args
+ .iter()
+ .map(ToString::to_string)
+ .collect::<Vec<_>>()
+ .join(", ");
+ format!("{}::<{}>", adt_def_ty_name, &tys_str)
+ } else {
+ binding_type.to_string()
+ }
+ };
+
+ let sugg = if ext_with_default {
+ if field_list.is_empty() {
+ format!("{}::default()", binding_type)
+ } else {
+ format!("{} {{ {}, ..Default::default() }}", binding_type, field_list)
+ }
+ } else {
+ format!("{} {{ {} }}", binding_type, field_list)
+ };
+
+ // span lint once per statement that binds default
+ span_lint_and_note(
+ cx,
+ FIELD_REASSIGN_WITH_DEFAULT,
+ first_assign.unwrap().span,
+ "field assignment outside of initializer for an instance created with Default::default()",
+ Some(local.span),
+ &format!(
+ "consider initializing the variable with `{}` and removing relevant reassignments",
+ sugg
+ ),
+ );
+ self.reassigned_linted.insert(span);
+ }
+ }
+ }
+}
+
+/// Checks if the given expression is the `default` method belonging to the `Default` trait.
+fn is_expr_default<'tcx>(expr: &'tcx Expr<'tcx>, cx: &LateContext<'tcx>) -> bool {
+ if_chain! {
+ if let ExprKind::Call(fn_expr, _) = &expr.kind;
+ if let ExprKind::Path(qpath) = &fn_expr.kind;
+ if let Res::Def(_, def_id) = cx.qpath_res(qpath, fn_expr.hir_id);
+ then {
+ // right hand side of assignment is `Default::default`
+ match_def_path(cx, def_id, &paths::DEFAULT_TRAIT_METHOD)
+ } else {
+ false
+ }
+ }
+}
+
+/// Returns the reassigned field and the assigning expression (right-hand side of assign).
+fn field_reassigned_by_stmt<'tcx>(this: &Stmt<'tcx>, binding_name: Symbol) -> Option<(Ident, &'tcx Expr<'tcx>)> {
+ if_chain! {
+ // only take assignments
+ if let StmtKind::Semi(later_expr) = this.kind;
+ if let ExprKind::Assign(assign_lhs, assign_rhs, _) = later_expr.kind;
+ // only take assignments to fields where the left-hand side field is a field of
+ // the same binding as the previous statement
+ if let ExprKind::Field(binding, field_ident) = assign_lhs.kind;
+ if let ExprKind::Path(QPath::Resolved(_, path)) = binding.kind;
+ if let Some(second_binding_name) = path.segments.last();
+ if second_binding_name.ident.name == binding_name;
+ then {
+ Some((field_ident, assign_rhs))
+ } else {
+ None
+ }
+ }
+}
+
+/// Returns whether `expr` is the update syntax base: `Foo { a: 1, .. base }`
+fn is_update_syntax_base<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> bool {
+ if_chain! {
+ if let Some(parent) = get_parent_expr(cx, expr);
+ if let ExprKind::Struct(_, _, Some(base)) = parent.kind;
+ then {
+ base.hir_id == expr.hir_id
+ } else {
+ false
+ }
+ }
+}
--- /dev/null
- use clippy_utils::diagnostics::span_lint_and_sugg;
++use clippy_utils::diagnostics::span_lint_hir_and_then;
+use clippy_utils::numeric_literal;
+use clippy_utils::source::snippet_opt;
+use if_chain::if_chain;
+use rustc_ast::ast::{LitFloatType, LitIntType, LitKind};
+use rustc_errors::Applicability;
+use rustc_hir::{
+ intravisit::{walk_expr, walk_stmt, Visitor},
+ Body, Expr, ExprKind, HirId, Lit, Stmt, StmtKind,
+};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::{
+ lint::in_external_macro,
+ ty::{self, FloatTy, IntTy, PolyFnSig, Ty},
+};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use std::iter;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of unconstrained numeric literals which may cause default numeric fallback in type
+ /// inference.
+ ///
+ /// Default numeric fallback means that if numeric types have not yet been bound to concrete
+ /// types at the end of type inference, then integer type is bound to `i32`, and similarly
+ /// floating type is bound to `f64`.
+ ///
+ /// See [RFC0212](https://github.com/rust-lang/rfcs/blob/master/text/0212-restore-int-fallback.md) for more information about the fallback.
+ ///
+ /// ### Why is this bad?
+ /// For those who are very careful about types, default numeric fallback
+ /// can be a pitfall that cause unexpected runtime behavior.
+ ///
+ /// ### Known problems
+ /// This lint can only be allowed at the function level or above.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let i = 10;
+ /// let f = 1.23;
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// let i = 10i32;
+ /// let f = 1.23f64;
+ /// ```
+ #[clippy::version = "1.52.0"]
+ pub DEFAULT_NUMERIC_FALLBACK,
+ restriction,
+ "usage of unconstrained numeric literals which may cause default numeric fallback."
+}
+
+declare_lint_pass!(DefaultNumericFallback => [DEFAULT_NUMERIC_FALLBACK]);
+
+impl<'tcx> LateLintPass<'tcx> for DefaultNumericFallback {
+ fn check_body(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'_>) {
+ let mut visitor = NumericFallbackVisitor::new(cx);
+ visitor.visit_body(body);
+ }
+}
+
+struct NumericFallbackVisitor<'a, 'tcx> {
+ /// Stack manages type bound of exprs. The top element holds current expr type.
+ ty_bounds: Vec<TyBound<'tcx>>,
+
+ cx: &'a LateContext<'tcx>,
+}
+
+impl<'a, 'tcx> NumericFallbackVisitor<'a, 'tcx> {
+ fn new(cx: &'a LateContext<'tcx>) -> Self {
+ Self {
+ ty_bounds: vec![TyBound::Nothing],
+ cx,
+ }
+ }
+
+ /// Check whether a passed literal has potential to cause fallback or not.
- fn check_lit(&self, lit: &Lit, lit_ty: Ty<'tcx>) {
++ fn check_lit(&self, lit: &Lit, lit_ty: Ty<'tcx>, emit_hir_id: HirId) {
+ if_chain! {
+ if !in_external_macro(self.cx.sess(), lit.span);
+ if let Some(ty_bound) = self.ty_bounds.last();
+ if matches!(lit.node,
+ LitKind::Int(_, LitIntType::Unsuffixed) | LitKind::Float(_, LitFloatType::Unsuffixed));
+ if !ty_bound.is_numeric();
+ then {
+ let (suffix, is_float) = match lit_ty.kind() {
+ ty::Int(IntTy::I32) => ("i32", false),
+ ty::Float(FloatTy::F64) => ("f64", true),
+ // Default numeric fallback never results in other types.
+ _ => return,
+ };
+
+ let src = if let Some(src) = snippet_opt(self.cx, lit.span) {
+ src
+ } else {
+ match lit.node {
+ LitKind::Int(src, _) => format!("{}", src),
+ LitKind::Float(src, _) => format!("{}", src),
+ _ => return,
+ }
+ };
+ let sugg = numeric_literal::format(&src, Some(suffix), is_float);
- span_lint_and_sugg(
++ span_lint_hir_and_then(
+ self.cx,
+ DEFAULT_NUMERIC_FALLBACK,
++ emit_hir_id,
+ lit.span,
+ "default numeric fallback might occur",
- "consider adding suffix",
- sugg,
- Applicability::MaybeIncorrect,
++ |diag| {
++ diag.span_suggestion(lit.span, "consider adding suffix", sugg, Applicability::MaybeIncorrect);
++ }
+ );
+ }
+ }
+ }
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for NumericFallbackVisitor<'a, 'tcx> {
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ match &expr.kind {
+ ExprKind::Call(func, args) => {
+ if let Some(fn_sig) = fn_sig_opt(self.cx, func.hir_id) {
+ for (expr, bound) in iter::zip(*args, fn_sig.skip_binder().inputs()) {
+ // Push found arg type, then visit arg.
+ self.ty_bounds.push(TyBound::Ty(*bound));
+ self.visit_expr(expr);
+ self.ty_bounds.pop();
+ }
+ return;
+ }
+ },
+
+ ExprKind::MethodCall(_, args, _) => {
+ if let Some(def_id) = self.cx.typeck_results().type_dependent_def_id(expr.hir_id) {
+ let fn_sig = self.cx.tcx.fn_sig(def_id).skip_binder();
+ for (expr, bound) in iter::zip(*args, fn_sig.inputs()) {
+ self.ty_bounds.push(TyBound::Ty(*bound));
+ self.visit_expr(expr);
+ self.ty_bounds.pop();
+ }
+ return;
+ }
+ },
+
+ ExprKind::Struct(_, fields, base) => {
+ let ty = self.cx.typeck_results().expr_ty(expr);
+ if_chain! {
+ if let Some(adt_def) = ty.ty_adt_def();
+ if adt_def.is_struct();
+ if let Some(variant) = adt_def.variants().iter().next();
+ then {
+ let fields_def = &variant.fields;
+
+ // Push field type then visit each field expr.
+ for field in fields.iter() {
+ let bound =
+ fields_def
+ .iter()
+ .find_map(|f_def| {
+ if f_def.ident(self.cx.tcx) == field.ident
+ { Some(self.cx.tcx.type_of(f_def.did)) }
+ else { None }
+ });
+ self.ty_bounds.push(bound.into());
+ self.visit_expr(field.expr);
+ self.ty_bounds.pop();
+ }
+
+ // Visit base with no bound.
+ if let Some(base) = base {
+ self.ty_bounds.push(TyBound::Nothing);
+ self.visit_expr(base);
+ self.ty_bounds.pop();
+ }
+ return;
+ }
+ }
+ },
+
+ ExprKind::Lit(lit) => {
+ let ty = self.cx.typeck_results().expr_ty(expr);
- self.check_lit(lit, ty);
++ self.check_lit(lit, ty, expr.hir_id);
+ return;
+ },
+
+ _ => {},
+ }
+
+ walk_expr(self, expr);
+ }
+
+ fn visit_stmt(&mut self, stmt: &'tcx Stmt<'_>) {
+ match stmt.kind {
+ StmtKind::Local(local) => {
+ if local.ty.is_some() {
+ self.ty_bounds.push(TyBound::Any);
+ } else {
+ self.ty_bounds.push(TyBound::Nothing);
+ }
+ },
+
+ _ => self.ty_bounds.push(TyBound::Nothing),
+ }
+
+ walk_stmt(self, stmt);
+ self.ty_bounds.pop();
+ }
+}
+
+fn fn_sig_opt<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<PolyFnSig<'tcx>> {
+ let node_ty = cx.typeck_results().node_type_opt(hir_id)?;
+ // We can't use `Ty::fn_sig` because it automatically performs substs, this may result in FNs.
+ match node_ty.kind() {
+ ty::FnDef(def_id, _) => Some(cx.tcx.fn_sig(*def_id)),
+ ty::FnPtr(fn_sig) => Some(*fn_sig),
+ _ => None,
+ }
+}
+
+#[derive(Debug, Clone, Copy)]
+enum TyBound<'tcx> {
+ Any,
+ Ty(Ty<'tcx>),
+ Nothing,
+}
+
+impl<'tcx> TyBound<'tcx> {
+ fn is_numeric(self) -> bool {
+ match self {
+ TyBound::Any => true,
+ TyBound::Ty(t) => t.is_numeric(),
+ TyBound::Nothing => false,
+ }
+ }
+}
+
+impl<'tcx> From<Option<Ty<'tcx>>> for TyBound<'tcx> {
+ fn from(v: Option<Ty<'tcx>>) -> Self {
+ match v {
+ Some(t) => TyBound::Ty(t),
+ None => TyBound::Nothing,
+ }
+ }
+}
--- /dev/null
- use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
++use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_hir_and_then};
+use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
+use clippy_utils::sugg::has_enclosing_paren;
+use clippy_utils::ty::peel_mid_ty_refs;
+use clippy_utils::{get_parent_expr, get_parent_node, is_lint_allowed, path_to_local};
+use rustc_ast::util::parser::{PREC_POSTFIX, PREC_PREFIX};
+use rustc_data_structures::fx::FxIndexMap;
+use rustc_errors::Applicability;
+use rustc_hir::{
+ BindingAnnotation, Body, BodyId, BorrowKind, Destination, Expr, ExprKind, HirId, MatchSource, Mutability, Node,
+ Pat, PatKind, UnOp,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeckResults};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::{symbol::sym, Span};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for explicit `deref()` or `deref_mut()` method calls.
+ ///
+ /// ### Why is this bad?
+ /// Dereferencing by `&*x` or `&mut *x` is clearer and more concise,
+ /// when not part of a method chain.
+ ///
+ /// ### Example
+ /// ```rust
+ /// use std::ops::Deref;
+ /// let a: &mut String = &mut String::from("foo");
+ /// let b: &str = a.deref();
+ /// ```
- /// Could be written as:
++ ///
++ /// Use instead:
+ /// ```rust
+ /// let a: &mut String = &mut String::from("foo");
+ /// let b = &*a;
+ /// ```
+ ///
- /// This lint excludes
++ /// This lint excludes:
+ /// ```rust,ignore
+ /// let _ = d.unwrap().deref();
+ /// ```
+ #[clippy::version = "1.44.0"]
+ pub EXPLICIT_DEREF_METHODS,
+ pedantic,
+ "Explicit use of deref or deref_mut method while not in a method chain."
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for address of operations (`&`) that are going to
+ /// be dereferenced immediately by the compiler.
+ ///
+ /// ### Why is this bad?
+ /// Suggests that the receiver of the expression borrows
+ /// the expression.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn fun(_a: &i32) {}
+ ///
- /// // Bad
+ /// let x: &i32 = &&&&&&5;
+ /// fun(&x);
++ /// ```
+ ///
- /// // Good
++ /// Use instead:
++ /// ```rust
++ /// # fn fun(_a: &i32) {}
+ /// let x: &i32 = &5;
+ /// fun(x);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NEEDLESS_BORROW,
+ style,
+ "taking a reference that is going to be automatically dereferenced"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `ref` bindings which create a reference to a reference.
+ ///
+ /// ### Why is this bad?
+ /// The address-of operator at the use site is clearer about the need for a reference.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Bad
+ /// let x = Some("");
+ /// if let Some(ref x) = x {
+ /// // use `x` here
+ /// }
++ /// ```
+ ///
- /// // Good
++ /// Use instead:
++ /// ```rust
+ /// let x = Some("");
+ /// if let Some(x) = x {
+ /// // use `&x` here
+ /// }
+ /// ```
+ #[clippy::version = "1.54.0"]
+ pub REF_BINDING_TO_REFERENCE,
+ pedantic,
+ "`ref` binding to a reference"
+}
+
+impl_lint_pass!(Dereferencing => [
+ EXPLICIT_DEREF_METHODS,
+ NEEDLESS_BORROW,
+ REF_BINDING_TO_REFERENCE,
+]);
+
+#[derive(Default)]
+pub struct Dereferencing {
+ state: Option<(State, StateData)>,
+
+ // While parsing a `deref` method call in ufcs form, the path to the function is itself an
+ // expression. This is to store the id of that expression so it can be skipped when
+ // `check_expr` is called for it.
+ skip_expr: Option<HirId>,
+
+ /// The body the first local was found in. Used to emit lints when the traversal of the body has
+ /// been finished. Note we can't lint at the end of every body as they can be nested within each
+ /// other.
+ current_body: Option<BodyId>,
+ /// The list of locals currently being checked by the lint.
+ /// If the value is `None`, then the binding has been seen as a ref pattern, but is not linted.
+ /// This is needed for or patterns where one of the branches can be linted, but another can not
+ /// be.
+ ///
+ /// e.g. `m!(x) | Foo::Bar(ref x)`
+ ref_locals: FxIndexMap<HirId, Option<RefPat>>,
+}
+
+struct StateData {
+ /// Span of the top level expression
+ span: Span,
++ hir_id: HirId,
+}
+
+enum State {
+ // Any number of deref method calls.
+ DerefMethod {
+ // The number of calls in a sequence which changed the referenced type
+ ty_changed_count: usize,
+ is_final_ufcs: bool,
+ /// The required mutability
+ target_mut: Mutability,
+ },
+ DerefedBorrow {
+ count: usize,
+ required_precedence: i8,
+ msg: &'static str,
+ },
+}
+
+// A reference operation considered by this lint pass
+enum RefOp {
+ Method(Mutability),
+ Deref,
+ AddrOf,
+}
+
+struct RefPat {
+ /// Whether every usage of the binding is dereferenced.
+ always_deref: bool,
+ /// The spans of all the ref bindings for this local.
+ spans: Vec<Span>,
+ /// The applicability of this suggestion.
+ app: Applicability,
+ /// All the replacements which need to be made.
+ replacements: Vec<(Span, String)>,
++ /// The [`HirId`] that the lint should be emitted at.
++ hir_id: HirId,
+}
+
+impl<'tcx> LateLintPass<'tcx> for Dereferencing {
+ #[expect(clippy::too_many_lines)]
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ // Skip path expressions from deref calls. e.g. `Deref::deref(e)`
+ if Some(expr.hir_id) == self.skip_expr.take() {
+ return;
+ }
+
+ if let Some(local) = path_to_local(expr) {
+ self.check_local_usage(cx, expr, local);
+ }
+
+ // Stop processing sub expressions when a macro call is seen
+ if expr.span.from_expansion() {
+ if let Some((state, data)) = self.state.take() {
+ report(cx, expr, state, data);
+ }
+ return;
+ }
+
+ let typeck = cx.typeck_results();
+ let (kind, sub_expr) = if let Some(x) = try_parse_ref_op(cx.tcx, typeck, expr) {
+ x
+ } else {
+ // The whole chain of reference operations has been seen
+ if let Some((state, data)) = self.state.take() {
+ report(cx, expr, state, data);
+ }
+ return;
+ };
+
+ match (self.state.take(), kind) {
+ (None, kind) => {
+ let parent = get_parent_node(cx.tcx, expr.hir_id);
+ let expr_ty = typeck.expr_ty(expr);
+
+ match kind {
+ RefOp::Method(target_mut)
+ if !is_lint_allowed(cx, EXPLICIT_DEREF_METHODS, expr.hir_id)
+ && is_linted_explicit_deref_position(parent, expr.hir_id, expr.span) =>
+ {
+ self.state = Some((
+ State::DerefMethod {
+ ty_changed_count: if deref_method_same_type(expr_ty, typeck.expr_ty(sub_expr)) {
+ 0
+ } else {
+ 1
+ },
+ is_final_ufcs: matches!(expr.kind, ExprKind::Call(..)),
+ target_mut,
+ },
- StateData { span: expr.span },
++ StateData {
++ span: expr.span,
++ hir_id: expr.hir_id,
++ },
+ ));
+ },
+ RefOp::AddrOf => {
+ // Find the number of times the borrow is auto-derefed.
+ let mut iter = find_adjustments(cx.tcx, typeck, expr).iter();
+ let mut deref_count = 0usize;
+ let next_adjust = loop {
+ match iter.next() {
+ Some(adjust) => {
+ if !matches!(adjust.kind, Adjust::Deref(_)) {
+ break Some(adjust);
+ } else if !adjust.target.is_ref() {
+ deref_count += 1;
+ break iter.next();
+ }
+ deref_count += 1;
+ },
+ None => break None,
+ };
+ };
+
+ // Determine the required number of references before any can be removed. In all cases the
+ // reference made by the current expression will be removed. After that there are four cases to
+ // handle.
+ //
+ // 1. Auto-borrow will trigger in the current position, so no further references are required.
+ // 2. Auto-deref ends at a reference, or the underlying type, so one extra needs to be left to
+ // handle the automatically inserted re-borrow.
+ // 3. Auto-deref hits a user-defined `Deref` impl, so at least one reference needs to exist to
+ // start auto-deref.
+ // 4. If the chain of non-user-defined derefs ends with a mutable re-borrow, and re-borrow
+ // adjustments will not be inserted automatically, then leave one further reference to avoid
+ // moving a mutable borrow.
+ // e.g.
+ // fn foo<T>(x: &mut Option<&mut T>, y: &mut T) {
+ // let x = match x {
+ // // Removing the borrow will cause `x` to be moved
+ // Some(x) => &mut *x,
+ // None => y
+ // };
+ // }
+ let deref_msg =
+ "this expression creates a reference which is immediately dereferenced by the compiler";
+ let borrow_msg = "this expression borrows a value the compiler would automatically borrow";
+
+ let (required_refs, required_precedence, msg) = if is_auto_borrow_position(parent, expr.hir_id)
+ {
+ (1, PREC_POSTFIX, if deref_count == 1 { borrow_msg } else { deref_msg })
+ } else if let Some(&Adjust::Borrow(AutoBorrow::Ref(_, mutability))) =
+ next_adjust.map(|a| &a.kind)
+ {
+ if matches!(mutability, AutoBorrowMutability::Mut { .. })
+ && !is_auto_reborrow_position(parent)
+ {
+ (3, 0, deref_msg)
+ } else {
+ (2, 0, deref_msg)
+ }
+ } else {
+ (2, 0, deref_msg)
+ };
+
+ if deref_count >= required_refs {
+ self.state = Some((
+ State::DerefedBorrow {
+ // One of the required refs is for the current borrow expression, the remaining ones
+ // can't be removed without breaking the code. See earlier comment.
+ count: deref_count - required_refs,
+ required_precedence,
+ msg,
+ },
- StateData { span: expr.span },
++ StateData {
++ span: expr.span,
++ hir_id: expr.hir_id,
++ },
+ ));
+ }
+ },
+ _ => (),
+ }
+ },
+ (
+ Some((
+ State::DerefMethod {
+ target_mut,
+ ty_changed_count,
+ ..
+ },
+ data,
+ )),
+ RefOp::Method(_),
+ ) => {
+ self.state = Some((
+ State::DerefMethod {
+ ty_changed_count: if deref_method_same_type(typeck.expr_ty(expr), typeck.expr_ty(sub_expr)) {
+ ty_changed_count
+ } else {
+ ty_changed_count + 1
+ },
+ is_final_ufcs: matches!(expr.kind, ExprKind::Call(..)),
+ target_mut,
+ },
+ data,
+ ));
+ },
+ (
+ Some((
+ State::DerefedBorrow {
+ count,
+ required_precedence,
+ msg,
+ },
+ data,
+ )),
+ RefOp::AddrOf,
+ ) if count != 0 => {
+ self.state = Some((
+ State::DerefedBorrow {
+ count: count - 1,
+ required_precedence,
+ msg,
+ },
+ data,
+ ));
+ },
+
+ (Some((state, data)), _) => report(cx, expr, state, data),
+ }
+ }
+
+ fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) {
+ if let PatKind::Binding(BindingAnnotation::Ref, id, name, _) = pat.kind {
+ if let Some(opt_prev_pat) = self.ref_locals.get_mut(&id) {
+ // This binding id has been seen before. Add this pattern to the list of changes.
+ if let Some(prev_pat) = opt_prev_pat {
+ if pat.span.from_expansion() {
+ // Doesn't match the context of the previous pattern. Can't lint here.
+ *opt_prev_pat = None;
+ } else {
+ prev_pat.spans.push(pat.span);
+ prev_pat.replacements.push((
+ pat.span,
+ snippet_with_context(cx, name.span, pat.span.ctxt(), "..", &mut prev_pat.app)
+ .0
+ .into(),
+ ));
+ }
+ }
+ return;
+ }
+
+ if_chain! {
+ if !pat.span.from_expansion();
+ if let ty::Ref(_, tam, _) = *cx.typeck_results().pat_ty(pat).kind();
+ // only lint immutable refs, because borrowed `&mut T` cannot be moved out
+ if let ty::Ref(_, _, Mutability::Not) = *tam.kind();
+ then {
+ let mut app = Applicability::MachineApplicable;
+ let snip = snippet_with_context(cx, name.span, pat.span.ctxt(), "..", &mut app).0;
+ self.current_body = self.current_body.or(cx.enclosing_body);
+ self.ref_locals.insert(
+ id,
+ Some(RefPat {
+ always_deref: true,
+ spans: vec![pat.span],
+ app,
+ replacements: vec![(pat.span, snip.into())],
++ hir_id: pat.hir_id
+ }),
+ );
+ }
+ }
+ }
+ }
+
+ fn check_body_post(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'_>) {
+ if Some(body.id()) == self.current_body {
+ for pat in self.ref_locals.drain(..).filter_map(|(_, x)| x) {
+ let replacements = pat.replacements;
+ let app = pat.app;
- span_lint_and_then(
++ let lint = if pat.always_deref {
++ NEEDLESS_BORROW
++ } else {
++ REF_BINDING_TO_REFERENCE
++ };
++ span_lint_hir_and_then(
+ cx,
- if pat.always_deref {
- NEEDLESS_BORROW
- } else {
- REF_BINDING_TO_REFERENCE
- },
++ lint,
++ pat.hir_id,
+ pat.spans,
+ "this pattern creates a reference to a reference",
+ |diag| {
+ diag.multipart_suggestion("try this", replacements, app);
+ },
+ );
+ }
+ self.current_body = None;
+ }
+ }
+}
+
+fn try_parse_ref_op<'tcx>(
+ tcx: TyCtxt<'tcx>,
+ typeck: &'tcx TypeckResults<'_>,
+ expr: &'tcx Expr<'_>,
+) -> Option<(RefOp, &'tcx Expr<'tcx>)> {
+ let (def_id, arg) = match expr.kind {
+ ExprKind::MethodCall(_, [arg], _) => (typeck.type_dependent_def_id(expr.hir_id)?, arg),
+ ExprKind::Call(
+ Expr {
+ kind: ExprKind::Path(path),
+ hir_id,
+ ..
+ },
+ [arg],
+ ) => (typeck.qpath_res(path, *hir_id).opt_def_id()?, arg),
+ ExprKind::Unary(UnOp::Deref, sub_expr) if !typeck.expr_ty(sub_expr).is_unsafe_ptr() => {
+ return Some((RefOp::Deref, sub_expr));
+ },
+ ExprKind::AddrOf(BorrowKind::Ref, _, sub_expr) => return Some((RefOp::AddrOf, sub_expr)),
+ _ => return None,
+ };
+ if tcx.is_diagnostic_item(sym::deref_method, def_id) {
+ Some((RefOp::Method(Mutability::Not), arg))
+ } else if tcx.trait_of_item(def_id)? == tcx.lang_items().deref_mut_trait()? {
+ Some((RefOp::Method(Mutability::Mut), arg))
+ } else {
+ None
+ }
+}
+
+// Checks whether the type for a deref call actually changed the type, not just the mutability of
+// the reference.
+fn deref_method_same_type<'tcx>(result_ty: Ty<'tcx>, arg_ty: Ty<'tcx>) -> bool {
+ match (result_ty.kind(), arg_ty.kind()) {
+ (ty::Ref(_, result_ty, _), ty::Ref(_, arg_ty, _)) => result_ty == arg_ty,
+
+ // The result type for a deref method is always a reference
+ // Not matching the previous pattern means the argument type is not a reference
+ // This means that the type did change
+ _ => false,
+ }
+}
+
+// Checks whether the parent node is a suitable context for switching from a deref method to the
+// deref operator.
+fn is_linted_explicit_deref_position(parent: Option<Node<'_>>, child_id: HirId, child_span: Span) -> bool {
+ let parent = match parent {
+ Some(Node::Expr(e)) if e.span.ctxt() == child_span.ctxt() => e,
+ _ => return true,
+ };
+ match parent.kind {
+ // Leave deref calls in the middle of a method chain.
+ // e.g. x.deref().foo()
+ ExprKind::MethodCall(_, [self_arg, ..], _) if self_arg.hir_id == child_id => false,
+
+ // Leave deref calls resulting in a called function
+ // e.g. (x.deref())()
+ ExprKind::Call(func_expr, _) if func_expr.hir_id == child_id => false,
+
+ // Makes an ugly suggestion
+ // e.g. *x.deref() => *&*x
+ ExprKind::Unary(UnOp::Deref, _)
+ // Postfix expressions would require parens
+ | ExprKind::Match(_, _, MatchSource::TryDesugar | MatchSource::AwaitDesugar)
+ | ExprKind::Field(..)
+ | ExprKind::Index(..)
+ | ExprKind::Err => false,
+
+ ExprKind::Box(..)
+ | ExprKind::ConstBlock(..)
+ | ExprKind::Array(_)
+ | ExprKind::Call(..)
+ | ExprKind::MethodCall(..)
+ | ExprKind::Tup(..)
+ | ExprKind::Binary(..)
+ | ExprKind::Unary(..)
+ | ExprKind::Lit(..)
+ | ExprKind::Cast(..)
+ | ExprKind::Type(..)
+ | ExprKind::DropTemps(..)
+ | ExprKind::If(..)
+ | ExprKind::Loop(..)
+ | ExprKind::Match(..)
+ | ExprKind::Let(..)
+ | ExprKind::Closure{..}
+ | ExprKind::Block(..)
+ | ExprKind::Assign(..)
+ | ExprKind::AssignOp(..)
+ | ExprKind::Path(..)
+ | ExprKind::AddrOf(..)
+ | ExprKind::Break(..)
+ | ExprKind::Continue(..)
+ | ExprKind::Ret(..)
+ | ExprKind::InlineAsm(..)
+ | ExprKind::Struct(..)
+ | ExprKind::Repeat(..)
+ | ExprKind::Yield(..) => true,
+ }
+}
+
+/// Checks if the given expression is in a position which can be auto-reborrowed.
+/// Note: This is only correct assuming auto-deref is already occurring.
+fn is_auto_reborrow_position(parent: Option<Node<'_>>) -> bool {
+ match parent {
+ Some(Node::Expr(parent)) => matches!(parent.kind, ExprKind::MethodCall(..) | ExprKind::Call(..)),
+ Some(Node::Local(_)) => true,
+ _ => false,
+ }
+}
+
+/// Checks if the given expression is a position which can auto-borrow.
+fn is_auto_borrow_position(parent: Option<Node<'_>>, child_id: HirId) -> bool {
+ if let Some(Node::Expr(parent)) = parent {
+ match parent.kind {
+ // ExprKind::MethodCall(_, [self_arg, ..], _) => self_arg.hir_id == child_id,
+ ExprKind::Field(..) => true,
+ ExprKind::Call(f, _) => f.hir_id == child_id,
+ _ => false,
+ }
+ } else {
+ false
+ }
+}
+
+/// Adjustments are sometimes made in the parent block rather than the expression itself.
+fn find_adjustments<'tcx>(
+ tcx: TyCtxt<'tcx>,
+ typeck: &'tcx TypeckResults<'tcx>,
+ expr: &'tcx Expr<'tcx>,
+) -> &'tcx [Adjustment<'tcx>] {
+ let map = tcx.hir();
+ let mut iter = map.parent_iter(expr.hir_id);
+ let mut prev = expr;
+
+ loop {
+ match typeck.expr_adjustments(prev) {
+ [] => (),
+ a => break a,
+ };
+
+ match iter.next().map(|(_, x)| x) {
+ Some(Node::Block(_)) => {
+ if let Some((_, Node::Expr(e))) = iter.next() {
+ prev = e;
+ } else {
+ // This shouldn't happen. Blocks are always contained in an expression.
+ break &[];
+ }
+ },
+ Some(Node::Expr(&Expr {
+ kind: ExprKind::Break(Destination { target_id: Ok(id), .. }, _),
+ ..
+ })) => {
+ if let Some(Node::Expr(e)) = map.find(id) {
+ prev = e;
+ iter = map.parent_iter(id);
+ } else {
+ // This shouldn't happen. The destination should exist.
+ break &[];
+ }
+ },
+ _ => break &[],
+ }
+ }
+}
+
+#[expect(clippy::needless_pass_by_value)]
+fn report<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>, state: State, data: StateData) {
+ match state {
+ State::DerefMethod {
+ ty_changed_count,
+ is_final_ufcs,
+ target_mut,
+ } => {
+ let mut app = Applicability::MachineApplicable;
+ let (expr_str, expr_is_macro_call) = snippet_with_context(cx, expr.span, data.span.ctxt(), "..", &mut app);
+ let ty = cx.typeck_results().expr_ty(expr);
+ let (_, ref_count) = peel_mid_ty_refs(ty);
+ let deref_str = if ty_changed_count >= ref_count && ref_count != 0 {
+ // a deref call changing &T -> &U requires two deref operators the first time
+ // this occurs. One to remove the reference, a second to call the deref impl.
+ "*".repeat(ty_changed_count + 1)
+ } else {
+ "*".repeat(ty_changed_count)
+ };
+ let addr_of_str = if ty_changed_count < ref_count {
+ // Check if a reborrow from &mut T -> &T is required.
+ if target_mut == Mutability::Not && matches!(ty.kind(), ty::Ref(_, _, Mutability::Mut)) {
+ "&*"
+ } else {
+ ""
+ }
+ } else if target_mut == Mutability::Mut {
+ "&mut "
+ } else {
+ "&"
+ };
+
+ let expr_str = if !expr_is_macro_call && is_final_ufcs && expr.precedence().order() < PREC_PREFIX {
+ format!("({})", expr_str)
+ } else {
+ expr_str.into_owned()
+ };
+
+ span_lint_and_sugg(
+ cx,
+ EXPLICIT_DEREF_METHODS,
+ data.span,
+ match target_mut {
+ Mutability::Not => "explicit `deref` method call",
+ Mutability::Mut => "explicit `deref_mut` method call",
+ },
+ "try this",
+ format!("{}{}{}", addr_of_str, deref_str, expr_str),
+ app,
+ );
+ },
+ State::DerefedBorrow {
+ required_precedence,
+ msg,
+ ..
+ } => {
+ let mut app = Applicability::MachineApplicable;
+ let snip = snippet_with_context(cx, expr.span, data.span.ctxt(), "..", &mut app).0;
- span_lint_and_sugg(
- cx,
- NEEDLESS_BORROW,
- data.span,
- msg,
- "change this to",
- if required_precedence > expr.precedence().order() && !has_enclosing_paren(&snip) {
++ span_lint_hir_and_then(cx, NEEDLESS_BORROW, data.hir_id, data.span, msg, |diag| {
++ let sugg = if required_precedence > expr.precedence().order() && !has_enclosing_paren(&snip) {
+ format!("({})", snip)
+ } else {
+ snip.into()
- },
- app,
- );
++ };
++ diag.span_suggestion(data.span, "change this to", sugg, app);
++ });
+ },
+ }
+}
+
+impl Dereferencing {
+ fn check_local_usage<'tcx>(&mut self, cx: &LateContext<'tcx>, e: &Expr<'tcx>, local: HirId) {
+ if let Some(outer_pat) = self.ref_locals.get_mut(&local) {
+ if let Some(pat) = outer_pat {
+ // Check for auto-deref
+ if !matches!(
+ cx.typeck_results().expr_adjustments(e),
+ [
+ Adjustment {
+ kind: Adjust::Deref(_),
+ ..
+ },
+ Adjustment {
+ kind: Adjust::Deref(_),
+ ..
+ },
+ ..
+ ]
+ ) {
+ match get_parent_expr(cx, e) {
+ // Field accesses are the same no matter the number of references.
+ Some(Expr {
+ kind: ExprKind::Field(..),
+ ..
+ }) => (),
+ Some(&Expr {
+ span,
+ kind: ExprKind::Unary(UnOp::Deref, _),
+ ..
+ }) if !span.from_expansion() => {
+ // Remove explicit deref.
+ let snip = snippet_with_context(cx, e.span, span.ctxt(), "..", &mut pat.app).0;
+ pat.replacements.push((span, snip.into()));
+ },
+ Some(parent) if !parent.span.from_expansion() => {
+ // Double reference might be needed at this point.
+ if parent.precedence().order() == PREC_POSTFIX {
+ // Parentheses would be needed here, don't lint.
+ *outer_pat = None;
+ } else {
+ pat.always_deref = false;
+ let snip = snippet_with_context(cx, e.span, parent.span.ctxt(), "..", &mut pat.app).0;
+ pat.replacements.push((e.span, format!("&{}", snip)));
+ }
+ },
+ _ if !e.span.from_expansion() => {
+ // Double reference might be needed at this point.
+ pat.always_deref = false;
+ let snip = snippet_with_applicability(cx, e.span, "..", &mut pat.app);
+ pat.replacements.push((e.span, format!("&{}", snip)));
+ },
+ // Edge case for macros. The span of the identifier will usually match the context of the
+ // binding, but not if the identifier was created in a macro. e.g. `concat_idents` and proc
+ // macros
+ _ => *outer_pat = None,
+ }
+ }
+ }
+ }
+ }
+}
--- /dev/null
- /// Could be written as:
- ///
+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
+ /// }
+ /// }
+ /// }
+ /// ```
+ ///
- ///
++ /// Use instead:
+ /// ```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
- self as hir, BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, HirId, Impl, Item, ItemKind, UnsafeSource, Unsafety,
+use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::paths;
+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::def_id::DefId;
+use rustc_hir::intravisit::{walk_expr, walk_fn, walk_item, FnKind, Visitor};
+use rustc_hir::{
- use rustc_middle::ty::subst::GenericArg;
- use rustc_middle::ty::{self, BoundConstness, ImplPolarity, ParamEnv, PredicateKind, TraitPredicate, TraitRef, Ty};
++ self as hir, BlockCheckMode, BodyId, Constness, Expr, ExprKind, FnDecl, HirId, Impl, Item, ItemKind, UnsafeSource,
++ Unsafety,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::nested_filter;
- if let Some(peq_trait_def_id) = cx.tcx.get_diagnostic_item(sym::PartialEq);
++use rustc_middle::traits::Reveal;
++use rustc_middle::ty::{
++ self, Binder, BoundConstness, GenericParamDefKind, ImplPolarity, ParamEnv, PredicateKind, TraitPredicate, TraitRef,
++ Ty, TyCtxt, Visibility,
++};
+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: &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,
+ 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.
+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<'_>,
+ 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.
+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 cx.tcx.visibility(adt.did()) == Visibility::Public;
+ if let Some(eq_trait_def_id) = cx.tcx.get_diagnostic_item(sym::Eq);
- // 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);
+ if let Some(def_id) = trait_ref.trait_def_id();
+ if cx.tcx.is_diagnostic_item(sym::PartialEq, def_id);
- // 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;
- }
- }
- }
-
++ let param_env = param_env_for_derived_eq(cx.tcx, adt.did(), eq_trait_def_id);
++ if !implements_trait_with_env(cx.tcx, param_env, ty, eq_trait_def_id, &[]);
++ // If all of our fields implement `Eq`, we can implement `Eq` too
++ if adt
++ .all_fields()
++ .map(|f| f.ty(cx.tcx, substs))
++ .all(|ty| implements_trait_with_env(cx.tcx, param_env, ty, eq_trait_def_id, &[]));
+ then {
+ 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,
+ )
+ }
+ }
+}
++
++/// Creates the `ParamEnv` used for the give type's derived `Eq` impl.
++fn param_env_for_derived_eq(tcx: TyCtxt<'_>, did: DefId, eq_trait_id: DefId) -> ParamEnv<'_> {
++ // Initial map from generic index to param def.
++ // Vec<(param_def, needs_eq)>
++ let mut params = tcx
++ .generics_of(did)
++ .params
++ .iter()
++ .map(|p| (p, matches!(p.kind, GenericParamDefKind::Type { .. })))
++ .collect::<Vec<_>>();
++
++ let ty_predicates = tcx.predicates_of(did).predicates;
++ for (p, _) in ty_predicates {
++ if let PredicateKind::Trait(p) = p.kind().skip_binder()
++ && p.trait_ref.def_id == eq_trait_id
++ && let ty::Param(self_ty) = p.trait_ref.self_ty().kind()
++ && p.constness == BoundConstness::NotConst
++ {
++ // Flag types which already have an `Eq` bound.
++ params[self_ty.index as usize].1 = false;
++ }
++ }
++
++ ParamEnv::new(
++ tcx.mk_predicates(ty_predicates.iter().map(|&(p, _)| p).chain(
++ params.iter().filter(|&&(_, needs_eq)| needs_eq).map(|&(param, _)| {
++ tcx.mk_predicate(Binder::dummy(PredicateKind::Trait(TraitPredicate {
++ trait_ref: TraitRef::new(eq_trait_id, tcx.mk_substs([tcx.mk_param_from_def(param)].into_iter())),
++ constness: BoundConstness::NotConst,
++ polarity: ImplPolarity::Positive,
++ })))
++ }),
++ )),
++ Reveal::UserFacing,
++ Constness::NotConst,
++ )
++}
--- /dev/null
- #[clippy::version = "1.52.0"]
+use clippy_utils::attrs::is_doc_hidden;
+use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_note, span_lint_and_then};
+use clippy_utils::macros::{is_panic, root_macro_call_first_node};
+use clippy_utils::source::{first_line_of_span, snippet_with_applicability};
+use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
+use clippy_utils::{is_entrypoint_fn, method_chain_args, return_ty};
+use if_chain::if_chain;
+use itertools::Itertools;
+use rustc_ast::ast::{Async, AttrKind, Attribute, Fn, FnRetTy, ItemKind};
+use rustc_ast::token::CommentKind;
+use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::sync::Lrc;
+use rustc_errors::emitter::EmitterWriter;
+use rustc_errors::{Applicability, Handler, MultiSpan, SuggestionStyle};
+use rustc_hir as hir;
+use rustc_hir::intravisit::{self, Visitor};
+use rustc_hir::{AnonConst, Expr};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::nested_filter;
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty;
+use rustc_parse::maybe_new_parser_from_source_str;
+use rustc_parse::parser::ForceCollect;
+use rustc_session::parse::ParseSess;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::LocalDefId;
+use rustc_span::edition::Edition;
+use rustc_span::source_map::{BytePos, FilePathMapping, SourceMap, Span};
+use rustc_span::{sym, FileName, Pos};
+use std::io;
+use std::ops::Range;
+use std::thread;
+use url::Url;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the presence of `_`, `::` or camel-case words
+ /// outside ticks in documentation.
+ ///
+ /// ### Why is this bad?
+ /// *Rustdoc* supports markdown formatting, `_`, `::` and
+ /// camel-case probably indicates some code which should be included between
+ /// ticks. `_` can also be used for emphasis in markdown, this lint tries to
+ /// consider that.
+ ///
+ /// ### Known problems
+ /// Lots of bad docs won’t be fixed, what the lint checks
+ /// for is limited, and there are still false positives. HTML elements and their
+ /// content are not linted.
+ ///
+ /// In addition, when writing documentation comments, including `[]` brackets
+ /// inside a link text would trip the parser. Therefore, documenting link with
+ /// `[`SmallVec<[T; INLINE_CAPACITY]>`]` and then [`SmallVec<[T; INLINE_CAPACITY]>`]: SmallVec
+ /// would fail.
+ ///
+ /// ### Examples
+ /// ```rust
+ /// /// Do something with the foo_bar parameter. See also
+ /// /// that::other::module::foo.
+ /// // ^ `foo_bar` and `that::other::module::foo` should be ticked.
+ /// fn doit(foo_bar: usize) {}
+ /// ```
+ ///
+ /// ```rust
+ /// // Link text with `[]` brackets should be written as following:
+ /// /// Consume the array and return the inner
+ /// /// [`SmallVec<[T; INLINE_CAPACITY]>`][SmallVec].
+ /// /// [SmallVec]: SmallVec
+ /// fn main() {}
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DOC_MARKDOWN,
+ pedantic,
+ "presence of `_`, `::` or camel-case outside backticks in documentation"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the doc comments of publicly visible
+ /// unsafe functions and warns if there is no `# Safety` section.
+ ///
+ /// ### Why is this bad?
+ /// Unsafe functions should document their safety
+ /// preconditions, so that users can be sure they are using them safely.
+ ///
+ /// ### Examples
+ /// ```rust
+ ///# type Universe = ();
+ /// /// This function should really be documented
+ /// pub unsafe fn start_apocalypse(u: &mut Universe) {
+ /// unimplemented!();
+ /// }
+ /// ```
+ ///
+ /// At least write a line about safety:
+ ///
+ /// ```rust
+ ///# type Universe = ();
+ /// /// # Safety
+ /// ///
+ /// /// This function should not be called before the horsemen are ready.
+ /// pub unsafe fn start_apocalypse(u: &mut Universe) {
+ /// unimplemented!();
+ /// }
+ /// ```
+ #[clippy::version = "1.39.0"]
+ pub MISSING_SAFETY_DOC,
+ style,
+ "`pub unsafe fn` without `# Safety` docs"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks the doc comments of publicly visible functions that
+ /// return a `Result` type and warns if there is no `# Errors` section.
+ ///
+ /// ### Why is this bad?
+ /// Documenting the type of errors that can be returned from a
+ /// function can help callers write code to handle the errors appropriately.
+ ///
+ /// ### Examples
+ /// Since the following function returns a `Result` it has an `# Errors` section in
+ /// its doc comment:
+ ///
+ /// ```rust
+ ///# use std::io;
+ /// /// # Errors
+ /// ///
+ /// /// Will return `Err` if `filename` does not exist or the user does not have
+ /// /// permission to read it.
+ /// pub fn read(filename: String) -> io::Result<String> {
+ /// unimplemented!();
+ /// }
+ /// ```
+ #[clippy::version = "1.41.0"]
+ pub MISSING_ERRORS_DOC,
+ pedantic,
+ "`pub fn` returns `Result` without `# Errors` in doc comment"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks the doc comments of publicly visible functions that
+ /// may panic and warns if there is no `# Panics` section.
+ ///
+ /// ### Why is this bad?
+ /// Documenting the scenarios in which panicking occurs
+ /// can help callers who do not want to panic to avoid those situations.
+ ///
+ /// ### Examples
+ /// Since the following function may panic it has a `# Panics` section in
+ /// its doc comment:
+ ///
+ /// ```rust
+ /// /// # Panics
+ /// ///
+ /// /// Will panic if y is 0
+ /// pub fn divide_by(x: i32, y: i32) -> i32 {
+ /// if y == 0 {
+ /// panic!("Cannot divide by 0")
+ /// } else {
+ /// x / y
+ /// }
+ /// }
+ /// ```
- /// ``````rust
++ #[clippy::version = "1.51.0"]
+ pub MISSING_PANICS_DOC,
+ pedantic,
+ "`pub fn` may panic without `# Panics` in doc comment"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `fn main() { .. }` in doctests
+ ///
+ /// ### Why is this bad?
+ /// The test can be shorter (and likely more readable)
+ /// if the `fn main()` is left implicit.
+ ///
+ /// ### Examples
- /// ``````
++ /// ```rust
+ /// /// An example of a doctest with a `main()` function
+ /// ///
+ /// /// # Examples
+ /// ///
+ /// /// ```
+ /// /// fn main() {
+ /// /// // this needs not be in an `fn`
+ /// /// }
+ /// /// ```
+ /// fn needless_main() {
+ /// unimplemented!();
+ /// }
++ /// ```
+ #[clippy::version = "1.40.0"]
+ pub NEEDLESS_DOCTEST_MAIN,
+ style,
+ "presence of `fn main() {` in code examples"
+}
+
+#[expect(clippy::module_name_repetitions)]
+#[derive(Clone)]
+pub struct DocMarkdown {
+ valid_idents: FxHashSet<String>,
+ in_trait_impl: bool,
+}
+
+impl DocMarkdown {
+ pub fn new(valid_idents: FxHashSet<String>) -> Self {
+ Self {
+ valid_idents,
+ in_trait_impl: false,
+ }
+ }
+}
+
+impl_lint_pass!(DocMarkdown =>
+ [DOC_MARKDOWN, MISSING_SAFETY_DOC, MISSING_ERRORS_DOC, MISSING_PANICS_DOC, NEEDLESS_DOCTEST_MAIN]
+);
+
+impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
+ fn check_crate(&mut self, cx: &LateContext<'tcx>) {
+ let attrs = cx.tcx.hir().attrs(hir::CRATE_HIR_ID);
+ check_attrs(cx, &self.valid_idents, attrs);
+ }
+
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
+ let attrs = cx.tcx.hir().attrs(item.hir_id());
+ let headers = check_attrs(cx, &self.valid_idents, attrs);
+ match item.kind {
+ hir::ItemKind::Fn(ref sig, _, body_id) => {
+ if !(is_entrypoint_fn(cx, item.def_id.to_def_id()) || in_external_macro(cx.tcx.sess, item.span)) {
+ let body = cx.tcx.hir().body(body_id);
+ let mut fpu = FindPanicUnwrap {
+ cx,
+ typeck_results: cx.tcx.typeck(item.def_id),
+ panic_span: None,
+ };
+ fpu.visit_expr(&body.value);
+ lint_for_missing_headers(cx, item.def_id, item.span, sig, headers, Some(body_id), fpu.panic_span);
+ }
+ },
+ hir::ItemKind::Impl(impl_) => {
+ self.in_trait_impl = impl_.of_trait.is_some();
+ },
+ hir::ItemKind::Trait(_, unsafety, ..) => {
+ if !headers.safety && unsafety == hir::Unsafety::Unsafe {
+ span_lint(
+ cx,
+ MISSING_SAFETY_DOC,
+ item.span,
+ "docs for unsafe trait missing `# Safety` section",
+ );
+ }
+ },
+ _ => (),
+ }
+ }
+
+ fn check_item_post(&mut self, _cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
+ if let hir::ItemKind::Impl { .. } = item.kind {
+ self.in_trait_impl = false;
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::TraitItem<'_>) {
+ let attrs = cx.tcx.hir().attrs(item.hir_id());
+ let headers = check_attrs(cx, &self.valid_idents, attrs);
+ if let hir::TraitItemKind::Fn(ref sig, ..) = item.kind {
+ if !in_external_macro(cx.tcx.sess, item.span) {
+ lint_for_missing_headers(cx, item.def_id, item.span, sig, headers, None, None);
+ }
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::ImplItem<'_>) {
+ let attrs = cx.tcx.hir().attrs(item.hir_id());
+ let headers = check_attrs(cx, &self.valid_idents, attrs);
+ if self.in_trait_impl || in_external_macro(cx.tcx.sess, item.span) {
+ return;
+ }
+ if let hir::ImplItemKind::Fn(ref sig, body_id) = item.kind {
+ let body = cx.tcx.hir().body(body_id);
+ let mut fpu = FindPanicUnwrap {
+ cx,
+ typeck_results: cx.tcx.typeck(item.def_id),
+ panic_span: None,
+ };
+ fpu.visit_expr(&body.value);
+ lint_for_missing_headers(cx, item.def_id, item.span, sig, headers, Some(body_id), fpu.panic_span);
+ }
+ }
+}
+
+fn lint_for_missing_headers<'tcx>(
+ cx: &LateContext<'tcx>,
+ def_id: LocalDefId,
+ span: impl Into<MultiSpan> + Copy,
+ sig: &hir::FnSig<'_>,
+ headers: DocHeaders,
+ body_id: Option<hir::BodyId>,
+ panic_span: Option<Span>,
+) {
+ if !cx.access_levels.is_exported(def_id) {
+ return; // Private functions do not require doc comments
+ }
+
+ // do not lint if any parent has `#[doc(hidden)]` attribute (#7347)
+ if cx
+ .tcx
+ .hir()
+ .parent_iter(cx.tcx.hir().local_def_id_to_hir_id(def_id))
+ .any(|(id, _node)| is_doc_hidden(cx.tcx.hir().attrs(id)))
+ {
+ return;
+ }
+
+ if !headers.safety && sig.header.unsafety == hir::Unsafety::Unsafe {
+ span_lint(
+ cx,
+ MISSING_SAFETY_DOC,
+ span,
+ "unsafe function's docs miss `# Safety` section",
+ );
+ }
+ if !headers.panics && panic_span.is_some() {
+ span_lint_and_note(
+ cx,
+ MISSING_PANICS_DOC,
+ span,
+ "docs for function which may panic missing `# Panics` section",
+ panic_span,
+ "first possible panic found here",
+ );
+ }
+ if !headers.errors {
+ let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
+ if is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym::Result) {
+ span_lint(
+ cx,
+ MISSING_ERRORS_DOC,
+ span,
+ "docs for function returning `Result` missing `# Errors` section",
+ );
+ } else {
+ if_chain! {
+ if let Some(body_id) = body_id;
+ if let Some(future) = cx.tcx.lang_items().future_trait();
+ let typeck = cx.tcx.typeck_body(body_id);
+ let body = cx.tcx.hir().body(body_id);
+ let ret_ty = typeck.expr_ty(&body.value);
+ if implements_trait(cx, ret_ty, future, &[]);
+ if let ty::Opaque(_, subs) = ret_ty.kind();
+ if let Some(gen) = subs.types().next();
+ if let ty::Generator(_, subs, _) = gen.kind();
+ if is_type_diagnostic_item(cx, subs.as_generator().return_ty(), sym::Result);
+ then {
+ span_lint(
+ cx,
+ MISSING_ERRORS_DOC,
+ span,
+ "docs for function returning `Result` missing `# Errors` section",
+ );
+ }
+ }
+ }
+ }
+}
+
+/// Cleanup documentation decoration.
+///
+/// We can't use `rustc_ast::attr::AttributeMethods::with_desugared_doc` or
+/// `rustc_ast::parse::lexer::comments::strip_doc_comment_decoration` because we
+/// need to keep track of
+/// the spans but this function is inspired from the later.
+#[expect(clippy::cast_possible_truncation)]
+#[must_use]
+pub fn strip_doc_comment_decoration(doc: &str, comment_kind: CommentKind, span: Span) -> (String, Vec<(usize, Span)>) {
+ // one-line comments lose their prefix
+ if comment_kind == CommentKind::Line {
+ let mut doc = doc.to_owned();
+ doc.push('\n');
+ let len = doc.len();
+ // +3 skips the opening delimiter
+ return (doc, vec![(len, span.with_lo(span.lo() + BytePos(3)))]);
+ }
+
+ let mut sizes = vec![];
+ let mut contains_initial_stars = false;
+ for line in doc.lines() {
+ let offset = line.as_ptr() as usize - doc.as_ptr() as usize;
+ debug_assert_eq!(offset as u32 as usize, offset);
+ contains_initial_stars |= line.trim_start().starts_with('*');
+ // +1 adds the newline, +3 skips the opening delimiter
+ sizes.push((line.len() + 1, span.with_lo(span.lo() + BytePos(3 + offset as u32))));
+ }
+ if !contains_initial_stars {
+ return (doc.to_string(), sizes);
+ }
+ // remove the initial '*'s if any
+ let mut no_stars = String::with_capacity(doc.len());
+ for line in doc.lines() {
+ let mut chars = line.chars();
+ for c in &mut chars {
+ if c.is_whitespace() {
+ no_stars.push(c);
+ } else {
+ no_stars.push(if c == '*' { ' ' } else { c });
+ break;
+ }
+ }
+ no_stars.push_str(chars.as_str());
+ no_stars.push('\n');
+ }
+
+ (no_stars, sizes)
+}
+
+#[derive(Copy, Clone)]
+struct DocHeaders {
+ safety: bool,
+ errors: bool,
+ panics: bool,
+}
+
+fn check_attrs<'a>(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, attrs: &'a [Attribute]) -> DocHeaders {
+ use pulldown_cmark::{BrokenLink, CowStr, Options};
+ /// We don't want the parser to choke on intra doc links. Since we don't
+ /// actually care about rendering them, just pretend that all broken links are
+ /// point to a fake address.
+ #[expect(clippy::unnecessary_wraps)] // we're following a type signature
+ fn fake_broken_link_callback<'a>(_: BrokenLink<'_>) -> Option<(CowStr<'a>, CowStr<'a>)> {
+ Some(("fake".into(), "fake".into()))
+ }
+
+ let mut doc = String::new();
+ let mut spans = vec![];
+
+ for attr in attrs {
+ if let AttrKind::DocComment(comment_kind, comment) = attr.kind {
+ let (comment, current_spans) = strip_doc_comment_decoration(comment.as_str(), comment_kind, attr.span);
+ spans.extend_from_slice(¤t_spans);
+ doc.push_str(&comment);
+ } else if attr.has_name(sym::doc) {
+ // ignore mix of sugared and non-sugared doc
+ // don't trigger the safety or errors check
+ return DocHeaders {
+ safety: true,
+ errors: true,
+ panics: true,
+ };
+ }
+ }
+
+ let mut current = 0;
+ for &mut (ref mut offset, _) in &mut spans {
+ let offset_copy = *offset;
+ *offset = current;
+ current += offset_copy;
+ }
+
+ if doc.is_empty() {
+ return DocHeaders {
+ safety: false,
+ errors: false,
+ panics: false,
+ };
+ }
+
+ let mut cb = fake_broken_link_callback;
+
+ let parser =
+ pulldown_cmark::Parser::new_with_broken_link_callback(&doc, Options::empty(), Some(&mut cb)).into_offset_iter();
+ // Iterate over all `Events` and combine consecutive events into one
+ let events = parser.coalesce(|previous, current| {
+ use pulldown_cmark::Event::Text;
+
+ let previous_range = previous.1;
+ let current_range = current.1;
+
+ match (previous.0, current.0) {
+ (Text(previous), Text(current)) => {
+ let mut previous = previous.to_string();
+ previous.push_str(¤t);
+ Ok((Text(previous.into()), previous_range))
+ },
+ (previous, current) => Err(((previous, previous_range), (current, current_range))),
+ }
+ });
+ check_doc(cx, valid_idents, events, &spans)
+}
+
+const RUST_CODE: &[&str] = &["rust", "no_run", "should_panic", "compile_fail"];
+
+fn check_doc<'a, Events: Iterator<Item = (pulldown_cmark::Event<'a>, Range<usize>)>>(
+ cx: &LateContext<'_>,
+ valid_idents: &FxHashSet<String>,
+ events: Events,
+ spans: &[(usize, Span)],
+) -> DocHeaders {
+ // true if a safety header was found
+ use pulldown_cmark::Event::{
+ Code, End, FootnoteReference, HardBreak, Html, Rule, SoftBreak, Start, TaskListMarker, Text,
+ };
+ use pulldown_cmark::Tag::{CodeBlock, Heading, Item, Link, Paragraph};
+ use pulldown_cmark::{CodeBlockKind, CowStr};
+
+ let mut headers = DocHeaders {
+ safety: false,
+ errors: false,
+ panics: false,
+ };
+ let mut in_code = false;
+ let mut in_link = None;
+ let mut in_heading = false;
+ let mut is_rust = false;
+ let mut edition = None;
+ let mut ticks_unbalanced = false;
+ let mut text_to_check: Vec<(CowStr<'_>, Span)> = Vec::new();
+ let mut paragraph_span = spans.get(0).expect("function isn't called if doc comment is empty").1;
+ for (event, range) in events {
+ match event {
+ Start(CodeBlock(ref kind)) => {
+ in_code = true;
+ if let CodeBlockKind::Fenced(lang) = kind {
+ for item in lang.split(',') {
+ if item == "ignore" {
+ is_rust = false;
+ break;
+ }
+ if let Some(stripped) = item.strip_prefix("edition") {
+ is_rust = true;
+ edition = stripped.parse::<Edition>().ok();
+ } else if item.is_empty() || RUST_CODE.contains(&item) {
+ is_rust = true;
+ }
+ }
+ }
+ },
+ End(CodeBlock(_)) => {
+ in_code = false;
+ is_rust = false;
+ },
+ Start(Link(_, url, _)) => in_link = Some(url),
+ End(Link(..)) => in_link = None,
+ Start(Heading(_, _, _) | Paragraph | Item) => {
+ if let Start(Heading(_, _, _)) = event {
+ in_heading = true;
+ }
+ ticks_unbalanced = false;
+ let (_, span) = get_current_span(spans, range.start);
+ paragraph_span = first_line_of_span(cx, span);
+ },
+ End(Heading(_, _, _) | Paragraph | Item) => {
+ if let End(Heading(_, _, _)) = event {
+ in_heading = false;
+ }
+ if ticks_unbalanced {
+ span_lint_and_help(
+ cx,
+ DOC_MARKDOWN,
+ paragraph_span,
+ "backticks are unbalanced",
+ None,
+ "a backtick may be missing a pair",
+ );
+ } else {
+ for (text, span) in text_to_check {
+ check_text(cx, valid_idents, &text, span);
+ }
+ }
+ text_to_check = Vec::new();
+ },
+ Start(_tag) | End(_tag) => (), // We don't care about other tags
+ Html(_html) => (), // HTML is weird, just ignore it
+ SoftBreak | HardBreak | TaskListMarker(_) | Code(_) | Rule => (),
+ FootnoteReference(text) | Text(text) => {
+ let (begin, span) = get_current_span(spans, range.start);
+ paragraph_span = paragraph_span.with_hi(span.hi());
+ ticks_unbalanced |= text.contains('`') && !in_code;
+ if Some(&text) == in_link.as_ref() || ticks_unbalanced {
+ // Probably a link of the form `<http://example.com>`
+ // Which are represented as a link to "http://example.com" with
+ // text "http://example.com" by pulldown-cmark
+ continue;
+ }
+ let trimmed_text = text.trim();
+ headers.safety |= in_heading && trimmed_text == "Safety";
+ headers.safety |= in_heading && trimmed_text == "Implementation safety";
+ headers.safety |= in_heading && trimmed_text == "Implementation Safety";
+ headers.errors |= in_heading && trimmed_text == "Errors";
+ headers.panics |= in_heading && trimmed_text == "Panics";
+ if in_code {
+ if is_rust {
+ let edition = edition.unwrap_or_else(|| cx.tcx.sess.edition());
+ check_code(cx, &text, edition, span);
+ }
+ } else {
+ // Adjust for the beginning of the current `Event`
+ let span = span.with_lo(span.lo() + BytePos::from_usize(range.start - begin));
+ text_to_check.push((text, span));
+ }
+ },
+ }
+ }
+ headers
+}
+
+fn get_current_span(spans: &[(usize, Span)], idx: usize) -> (usize, Span) {
+ let index = match spans.binary_search_by(|c| c.0.cmp(&idx)) {
+ Ok(o) => o,
+ Err(e) => e - 1,
+ };
+ spans[index]
+}
+
+fn check_code(cx: &LateContext<'_>, text: &str, edition: Edition, span: Span) {
+ fn has_needless_main(code: String, edition: Edition) -> bool {
+ rustc_driver::catch_fatal_errors(|| {
+ rustc_span::create_session_globals_then(edition, || {
+ let filename = FileName::anon_source_code(&code);
+
+ let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
+ let fallback_bundle =
+ rustc_errors::fallback_fluent_bundle(rustc_errors::DEFAULT_LOCALE_RESOURCES, false);
+ let emitter = EmitterWriter::new(
+ Box::new(io::sink()),
+ None,
+ None,
+ fallback_bundle,
+ false,
+ false,
+ false,
+ None,
+ false,
+ );
+ let handler = Handler::with_emitter(false, None, Box::new(emitter));
+ let sess = ParseSess::with_span_handler(handler, sm);
+
+ let mut parser = match maybe_new_parser_from_source_str(&sess, filename, code) {
+ Ok(p) => p,
+ Err(errs) => {
+ drop(errs);
+ return false;
+ },
+ };
+
+ let mut relevant_main_found = false;
+ loop {
+ match parser.parse_item(ForceCollect::No) {
+ Ok(Some(item)) => match &item.kind {
+ ItemKind::Fn(box Fn {
+ sig, body: Some(block), ..
+ }) if item.ident.name == sym::main => {
+ let is_async = matches!(sig.header.asyncness, Async::Yes { .. });
+ let returns_nothing = match &sig.decl.output {
+ FnRetTy::Default(..) => true,
+ FnRetTy::Ty(ty) if ty.kind.is_unit() => true,
+ FnRetTy::Ty(_) => false,
+ };
+
+ if returns_nothing && !is_async && !block.stmts.is_empty() {
+ // This main function should be linted, but only if there are no other functions
+ relevant_main_found = true;
+ } else {
+ // This main function should not be linted, we're done
+ return false;
+ }
+ },
+ // Tests with one of these items are ignored
+ ItemKind::Static(..)
+ | ItemKind::Const(..)
+ | ItemKind::ExternCrate(..)
+ | ItemKind::ForeignMod(..)
+ // Another function was found; this case is ignored
+ | ItemKind::Fn(..) => return false,
+ _ => {},
+ },
+ Ok(None) => break,
+ Err(e) => {
+ e.cancel();
+ return false;
+ },
+ }
+ }
+
+ relevant_main_found
+ })
+ })
+ .ok()
+ .unwrap_or_default()
+ }
+
+ // Because of the global session, we need to create a new session in a different thread with
+ // the edition we need.
+ let text = text.to_owned();
+ if thread::spawn(move || has_needless_main(text, edition))
+ .join()
+ .expect("thread::spawn failed")
+ {
+ span_lint(cx, NEEDLESS_DOCTEST_MAIN, span, "needless `fn main` in doctest");
+ }
+}
+
+fn check_text(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, text: &str, span: Span) {
+ for word in text.split(|c: char| c.is_whitespace() || c == '\'') {
+ // Trim punctuation as in `some comment (see foo::bar).`
+ // ^^
+ // Or even as in `_foo bar_` which is emphasized. Also preserve `::` as a prefix/suffix.
+ let mut word = word.trim_matches(|c: char| !c.is_alphanumeric() && c != ':');
+
+ // Remove leading or trailing single `:` which may be part of a sentence.
+ if word.starts_with(':') && !word.starts_with("::") {
+ word = word.trim_start_matches(':');
+ }
+ if word.ends_with(':') && !word.ends_with("::") {
+ word = word.trim_end_matches(':');
+ }
+
+ if valid_idents.contains(word) || word.chars().all(|c| c == ':') {
+ continue;
+ }
+
+ // Adjust for the current word
+ let offset = word.as_ptr() as usize - text.as_ptr() as usize;
+ let span = Span::new(
+ span.lo() + BytePos::from_usize(offset),
+ span.lo() + BytePos::from_usize(offset + word.len()),
+ span.ctxt(),
+ span.parent(),
+ );
+
+ check_word(cx, word, span);
+ }
+}
+
+fn check_word(cx: &LateContext<'_>, word: &str, span: Span) {
+ /// Checks if a string is camel-case, i.e., contains at least two uppercase
+ /// letters (`Clippy` is ok) and one lower-case letter (`NASA` is ok).
+ /// Plurals are also excluded (`IDs` is ok).
+ fn is_camel_case(s: &str) -> bool {
+ if s.starts_with(|c: char| c.is_ascii_digit()) {
+ return false;
+ }
+
+ let s = s.strip_suffix('s').unwrap_or(s);
+
+ s.chars().all(char::is_alphanumeric)
+ && s.chars().filter(|&c| c.is_uppercase()).take(2).count() > 1
+ && s.chars().filter(|&c| c.is_lowercase()).take(1).count() > 0
+ }
+
+ fn has_underscore(s: &str) -> bool {
+ s != "_" && !s.contains("\\_") && s.contains('_')
+ }
+
+ fn has_hyphen(s: &str) -> bool {
+ s != "-" && s.contains('-')
+ }
+
+ if let Ok(url) = Url::parse(word) {
+ // try to get around the fact that `foo::bar` parses as a valid URL
+ if !url.cannot_be_a_base() {
+ span_lint(
+ cx,
+ DOC_MARKDOWN,
+ span,
+ "you should put bare URLs between `<`/`>` or make a proper Markdown link",
+ );
+
+ return;
+ }
+ }
+
+ // We assume that mixed-case words are not meant to be put inside backticks. (Issue #2343)
+ if has_underscore(word) && has_hyphen(word) {
+ return;
+ }
+
+ if has_underscore(word) || word.contains("::") || is_camel_case(word) {
+ let mut applicability = Applicability::MachineApplicable;
+
+ span_lint_and_then(
+ cx,
+ DOC_MARKDOWN,
+ span,
+ "item in documentation is missing backticks",
+ |diag| {
+ let snippet = snippet_with_applicability(cx, span, "..", &mut applicability);
+ diag.span_suggestion_with_style(
+ span,
+ "try",
+ format!("`{}`", snippet),
+ applicability,
+ // always show the suggestion in a separate line, since the
+ // inline presentation adds another pair of backticks
+ SuggestionStyle::ShowAlways,
+ );
+ },
+ );
+ }
+}
+
+struct FindPanicUnwrap<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ panic_span: Option<Span>,
+ typeck_results: &'tcx ty::TypeckResults<'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for FindPanicUnwrap<'a, 'tcx> {
+ type NestedFilter = nested_filter::OnlyBodies;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if self.panic_span.is_some() {
+ return;
+ }
+
+ if let Some(macro_call) = root_macro_call_first_node(self.cx, expr) {
+ if is_panic(self.cx, macro_call.def_id)
+ || matches!(
+ self.cx.tcx.item_name(macro_call.def_id).as_str(),
+ "assert" | "assert_eq" | "assert_ne" | "todo"
+ )
+ {
+ self.panic_span = Some(macro_call.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.cx, receiver_ty, sym::Option)
+ || is_type_diagnostic_item(self.cx, receiver_ty, sym::Result)
+ {
+ self.panic_span = Some(expr.span);
+ }
+ }
+
+ // and check sub-expressions
+ intravisit::walk_expr(self, expr);
+ }
+
+ // Panics in const blocks will cause compilation to fail.
+ fn visit_anon_const(&mut self, _: &'tcx AnonConst) {}
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+}
--- /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;
+ /// }
+ /// ```
++ ///
++ /// Use instead:
+ /// ```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
- /// ### Known problems
- /// None
- ///
+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.
+ ///
- /// ```ignore
- /// // Bad
+ /// ### Example
- /// // Good
++ /// ```rust,ignore
+ /// &x == y
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust,ignore
+ /// 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
- /// // Bad
+use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::higher::VecArgs;
+use clippy_utils::source::snippet_opt;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::usage::local_used_after_expr;
+use clippy_utils::{higher, is_adjusted, path_to_local, path_to_local_id};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::def_id::DefId;
+use rustc_hir::{Expr, ExprKind, Param, PatKind, Unsafety};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow};
+use rustc_middle::ty::binding::BindingMode;
+use rustc_middle::ty::subst::Subst;
+use rustc_middle::ty::{self, ClosureKind, Ty, TypeFoldable};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for closures which just call another function where
+ /// the function can be called directly. `unsafe` functions or calls where types
+ /// get adjusted are ignored.
+ ///
+ /// ### Why is this bad?
+ /// Needlessly creating a closure adds code for no benefit
+ /// and gives the optimizer more work.
+ ///
+ /// ### Known problems
+ /// If creating the closure inside the closure has a side-
+ /// effect then moving the closure creation out will change when that side-
+ /// effect runs.
+ /// See [#1439](https://github.com/rust-lang/rust-clippy/issues/1439) for more details.
+ ///
+ /// ### Example
+ /// ```rust,ignore
- /// // Good
+ /// xs.map(|x| foo(x))
++ /// ```
+ ///
- /// where `foo(_)` is a plain function that takes the exact argument type of
- /// `x`.
++ /// Use instead:
++ /// ```rust,ignore
++ /// // where `foo(_)` is a plain function that takes the exact argument type of `x`.
+ /// xs.map(foo)
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub REDUNDANT_CLOSURE,
+ style,
+ "redundant closures, i.e., `|a| foo(a)` (which can be written as just `foo`)"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for closures which only invoke a method on the closure
+ /// argument and can be replaced by referencing the method directly.
+ ///
+ /// ### Why is this bad?
+ /// It's unnecessary to create the closure.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// Some('a').map(|s| s.to_uppercase());
+ /// ```
+ /// may be rewritten as
+ /// ```rust,ignore
+ /// Some('a').map(char::to_uppercase);
+ /// ```
+ #[clippy::version = "1.35.0"]
+ pub REDUNDANT_CLOSURE_FOR_METHOD_CALLS,
+ pedantic,
+ "redundant closures for method calls"
+}
+
+declare_lint_pass!(EtaReduction => [REDUNDANT_CLOSURE, REDUNDANT_CLOSURE_FOR_METHOD_CALLS]);
+
+impl<'tcx> LateLintPass<'tcx> for EtaReduction {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if expr.span.from_expansion() {
+ return;
+ }
+ let body = match expr.kind {
+ ExprKind::Closure { body, .. } => cx.tcx.hir().body(body),
+ _ => return,
+ };
+ if body.value.span.from_expansion() {
+ if body.params.is_empty() {
+ if let Some(VecArgs::Vec(&[])) = higher::VecArgs::hir(cx, &body.value) {
+ // replace `|| vec![]` with `Vec::new`
+ span_lint_and_sugg(
+ cx,
+ REDUNDANT_CLOSURE,
+ expr.span,
+ "redundant closure",
+ "replace the closure with `Vec::new`",
+ "std::vec::Vec::new".into(),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ // skip `foo(|| macro!())`
+ return;
+ }
+
+ let closure_ty = cx.typeck_results().expr_ty(expr);
+
+ if_chain!(
+ if !is_adjusted(cx, &body.value);
+ if let ExprKind::Call(callee, args) = body.value.kind;
+ if let ExprKind::Path(_) = callee.kind;
+ if check_inputs(cx, body.params, args);
+ let callee_ty = cx.typeck_results().expr_ty_adjusted(callee);
+ let call_ty = cx.typeck_results().type_dependent_def_id(body.value.hir_id)
+ .map_or(callee_ty, |id| cx.tcx.type_of(id));
+ if check_sig(cx, closure_ty, call_ty);
+ let substs = cx.typeck_results().node_substs(callee.hir_id);
+ // This fixes some false positives that I don't entirely understand
+ if substs.is_empty() || !cx.typeck_results().expr_ty(expr).has_late_bound_regions();
+ // A type param function ref like `T::f` is not 'static, however
+ // it is if cast like `T::f as fn()`. This seems like a rustc bug.
+ if !substs.types().any(|t| matches!(t.kind(), ty::Param(_)));
+ let callee_ty_unadjusted = cx.typeck_results().expr_ty(callee).peel_refs();
+ if !is_type_diagnostic_item(cx, callee_ty_unadjusted, sym::Arc);
+ if !is_type_diagnostic_item(cx, callee_ty_unadjusted, sym::Rc);
+ then {
+ span_lint_and_then(cx, REDUNDANT_CLOSURE, expr.span, "redundant closure", |diag| {
+ if let Some(mut snippet) = snippet_opt(cx, callee.span) {
+ if_chain! {
+ if let ty::Closure(_, substs) = callee_ty.peel_refs().kind();
+ if substs.as_closure().kind() == ClosureKind::FnMut;
+ if path_to_local(callee).map_or(false, |l| local_used_after_expr(cx, l, expr));
+
+ then {
+ // Mutable closure is used after current expr; we cannot consume it.
+ snippet = format!("&mut {}", snippet);
+ }
+ }
+ diag.span_suggestion(
+ expr.span,
+ "replace the closure with the function itself",
+ snippet,
+ Applicability::MachineApplicable,
+ );
+ }
+ });
+ }
+ );
+
+ if_chain!(
+ if !is_adjusted(cx, &body.value);
+ if let ExprKind::MethodCall(path, args, _) = body.value.kind;
+ if check_inputs(cx, body.params, args);
+ let method_def_id = cx.typeck_results().type_dependent_def_id(body.value.hir_id).unwrap();
+ let substs = cx.typeck_results().node_substs(body.value.hir_id);
+ let call_ty = cx.tcx.bound_type_of(method_def_id).subst(cx.tcx, substs);
+ if check_sig(cx, closure_ty, call_ty);
+ then {
+ span_lint_and_then(cx, REDUNDANT_CLOSURE_FOR_METHOD_CALLS, expr.span, "redundant closure", |diag| {
+ let name = get_ufcs_type_name(cx, method_def_id);
+ diag.span_suggestion(
+ expr.span,
+ "replace the closure with the method itself",
+ format!("{}::{}", name, path.ident.name),
+ Applicability::MachineApplicable,
+ );
+ })
+ }
+ );
+ }
+}
+
+fn check_inputs(cx: &LateContext<'_>, params: &[Param<'_>], call_args: &[Expr<'_>]) -> bool {
+ if params.len() != call_args.len() {
+ return false;
+ }
+ let binding_modes = cx.typeck_results().pat_binding_modes();
+ std::iter::zip(params, call_args).all(|(param, arg)| {
+ match param.pat.kind {
+ PatKind::Binding(_, id, ..) if path_to_local_id(arg, id) => {},
+ _ => return false,
+ }
+ // checks that parameters are not bound as `ref` or `ref mut`
+ if let Some(BindingMode::BindByReference(_)) = binding_modes.get(param.pat.hir_id) {
+ return false;
+ }
+
+ match *cx.typeck_results().expr_adjustments(arg) {
+ [] => true,
+ [
+ Adjustment {
+ kind: Adjust::Deref(None),
+ ..
+ },
+ Adjustment {
+ kind: Adjust::Borrow(AutoBorrow::Ref(_, mu2)),
+ ..
+ },
+ ] => {
+ // re-borrow with the same mutability is allowed
+ let ty = cx.typeck_results().expr_ty(arg);
+ matches!(*ty.kind(), ty::Ref(.., mu1) if mu1 == mu2.into())
+ },
+ _ => false,
+ }
+ })
+}
+
+fn check_sig<'tcx>(cx: &LateContext<'tcx>, closure_ty: Ty<'tcx>, call_ty: Ty<'tcx>) -> bool {
+ let call_sig = call_ty.fn_sig(cx.tcx);
+ if call_sig.unsafety() == Unsafety::Unsafe {
+ return false;
+ }
+ if !closure_ty.has_late_bound_regions() {
+ return true;
+ }
+ let substs = match closure_ty.kind() {
+ ty::Closure(_, substs) => substs,
+ _ => return false,
+ };
+ let closure_sig = cx.tcx.signature_unclosure(substs.as_closure().sig(), Unsafety::Normal);
+ cx.tcx.erase_late_bound_regions(closure_sig) == cx.tcx.erase_late_bound_regions(call_sig)
+}
+
+fn get_ufcs_type_name(cx: &LateContext<'_>, method_def_id: DefId) -> String {
+ match cx.tcx.associated_item(method_def_id).container {
+ ty::TraitContainer(def_id) => cx.tcx.def_path_str(def_id),
+ ty::ImplContainer(def_id) => {
+ let ty = cx.tcx.type_of(def_id);
+ match ty.kind() {
+ ty::Adt(adt, _) => cx.tcx.def_path_str(adt.did()),
+ _ => ty.to_string(),
+ }
+ },
+ }
+}
--- /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
+ /// ```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
- /// Good:
+ /// ```rust,ignore
+ /// fn f(is_round: bool, is_hot: bool) { ... }
+ /// ```
+ ///
++ /// Use instead:
+ /// ```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
- /// // 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
+ /// 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
- /// // Good
+ /// let _: f32 = 16_777_217.0; // 16_777_216.0
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
+ /// 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
- /// // Bad
+mod must_use;
+mod not_unsafe_ptr_arg_deref;
+mod result_unit_err;
+mod too_many_arguments;
+mod too_many_lines;
+
+use rustc_hir as hir;
+use rustc_hir::intravisit;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::Span;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for functions with too many parameters.
+ ///
+ /// ### Why is this bad?
+ /// Functions with lots of parameters are considered bad
+ /// style and reduce readability (“what does the 5th parameter mean?”). Consider
+ /// grouping some parameters into a new type.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # struct Color;
+ /// fn foo(x: u32, y: u32, name: &str, c: Color, w: f32, h: f32, a: f32, b: f32) {
+ /// // ..
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub TOO_MANY_ARGUMENTS,
+ complexity,
+ "functions with too many arguments"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for functions with a large amount of lines.
+ ///
+ /// ### Why is this bad?
+ /// Functions with a lot of lines are harder to understand
+ /// due to having to look at a larger amount of code to understand what the
+ /// function is doing. Consider splitting the body of the function into
+ /// multiple functions.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn im_too_long() {
+ /// println!("");
+ /// // ... 100 more LoC
+ /// println!("");
+ /// }
+ /// ```
+ #[clippy::version = "1.34.0"]
+ pub TOO_MANY_LINES,
+ pedantic,
+ "functions with too many lines"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for public functions that dereference raw pointer
+ /// arguments but are not marked `unsafe`.
+ ///
+ /// ### Why is this bad?
+ /// The function should probably be marked `unsafe`, since
+ /// for an arbitrary raw pointer, there is no way of telling for sure if it is
+ /// valid.
+ ///
+ /// ### Known problems
+ /// * It does not check functions recursively so if the pointer is passed to a
+ /// private non-`unsafe` function which does the dereferencing, the lint won't
+ /// trigger.
+ /// * It only checks for arguments whose type are raw pointers, not raw pointers
+ /// got from an argument in some other way (`fn foo(bar: &[*const u8])` or
+ /// `some_argument.get_raw_ptr()`).
+ ///
+ /// ### Example
+ /// ```rust,ignore
- /// // Good
+ /// pub fn foo(x: *const u8) {
+ /// println!("{}", unsafe { *x });
+ /// }
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust,ignore
+ /// pub unsafe fn foo(x: *const u8) {
+ /// println!("{}", unsafe { *x });
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NOT_UNSAFE_PTR_ARG_DEREF,
+ correctness,
+ "public functions dereferencing raw pointer arguments but not marked `unsafe`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for a `#[must_use]` attribute on
+ /// unit-returning functions and methods.
+ ///
+ /// ### Why is this bad?
+ /// Unit values are useless. The attribute is likely
+ /// a remnant of a refactoring that removed the return type.
+ ///
+ /// ### Examples
+ /// ```rust
+ /// #[must_use]
+ /// fn useless() { }
+ /// ```
+ #[clippy::version = "1.40.0"]
+ pub MUST_USE_UNIT,
+ style,
+ "`#[must_use]` attribute on a unit-returning function / method"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for a `#[must_use]` attribute without
+ /// further information on functions and methods that return a type already
+ /// marked as `#[must_use]`.
+ ///
+ /// ### Why is this bad?
+ /// The attribute isn't needed. Not using the result
+ /// will already be reported. Alternatively, one can add some text to the
+ /// attribute to improve the lint message.
+ ///
+ /// ### Examples
+ /// ```rust
+ /// #[must_use]
+ /// fn double_must_use() -> Result<(), ()> {
+ /// unimplemented!();
+ /// }
+ /// ```
+ #[clippy::version = "1.40.0"]
+ pub DOUBLE_MUST_USE,
+ style,
+ "`#[must_use]` attribute on a `#[must_use]`-returning function / method"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for public functions that have no
+ /// `#[must_use]` attribute, but return something not already marked
+ /// must-use, have no mutable arg and mutate no statics.
+ ///
+ /// ### Why is this bad?
+ /// Not bad at all, this lint just shows places where
+ /// you could add the attribute.
+ ///
+ /// ### Known problems
+ /// The lint only checks the arguments for mutable
+ /// types without looking if they are actually changed. On the other hand,
+ /// it also ignores a broad range of potentially interesting side effects,
+ /// because we cannot decide whether the programmer intends the function to
+ /// be called for the side effect or the result. Expect many false
+ /// positives. At least we don't lint if the result type is unit or already
+ /// `#[must_use]`.
+ ///
+ /// ### Examples
+ /// ```rust
+ /// // this could be annotated with `#[must_use]`.
+ /// fn id<T>(t: T) -> T { t }
+ /// ```
+ #[clippy::version = "1.40.0"]
+ pub MUST_USE_CANDIDATE,
+ pedantic,
+ "function or method that could take a `#[must_use]` attribute"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for public functions that return a `Result`
+ /// with an `Err` type of `()`. It suggests using a custom type that
+ /// implements `std::error::Error`.
+ ///
+ /// ### Why is this bad?
+ /// Unit does not implement `Error` and carries no
+ /// further information about what went wrong.
+ ///
+ /// ### Known problems
+ /// Of course, this lint assumes that `Result` is used
+ /// for a fallible operation (which is after all the intended use). However
+ /// code may opt to (mis)use it as a basic two-variant-enum. In that case,
+ /// the suggestion is misguided, and the code should use a custom enum
+ /// instead.
+ ///
+ /// ### Examples
+ /// ```rust
+ /// pub fn read_u8() -> Result<u8, ()> { Err(()) }
+ /// ```
+ /// should become
+ /// ```rust,should_panic
+ /// use std::fmt;
+ ///
+ /// #[derive(Debug)]
+ /// pub struct EndOfStream;
+ ///
+ /// impl fmt::Display for EndOfStream {
+ /// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ /// write!(f, "End of Stream")
+ /// }
+ /// }
+ ///
+ /// impl std::error::Error for EndOfStream { }
+ ///
+ /// pub fn read_u8() -> Result<u8, EndOfStream> { Err(EndOfStream) }
+ ///# fn main() {
+ ///# read_u8().unwrap();
+ ///# }
+ /// ```
+ ///
+ /// Note that there are crates that simplify creating the error type, e.g.
+ /// [`thiserror`](https://docs.rs/thiserror).
+ #[clippy::version = "1.49.0"]
+ pub RESULT_UNIT_ERR,
+ style,
+ "public function returning `Result` with an `Err` type of `()`"
+}
+
+#[derive(Copy, Clone)]
+pub struct Functions {
+ too_many_arguments_threshold: u64,
+ too_many_lines_threshold: u64,
+}
+
+impl Functions {
+ pub fn new(too_many_arguments_threshold: u64, too_many_lines_threshold: u64) -> Self {
+ Self {
+ too_many_arguments_threshold,
+ too_many_lines_threshold,
+ }
+ }
+}
+
+impl_lint_pass!(Functions => [
+ TOO_MANY_ARGUMENTS,
+ TOO_MANY_LINES,
+ NOT_UNSAFE_PTR_ARG_DEREF,
+ MUST_USE_UNIT,
+ DOUBLE_MUST_USE,
+ MUST_USE_CANDIDATE,
+ RESULT_UNIT_ERR,
+]);
+
+impl<'tcx> LateLintPass<'tcx> for Functions {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ kind: intravisit::FnKind<'tcx>,
+ decl: &'tcx hir::FnDecl<'_>,
+ body: &'tcx hir::Body<'_>,
+ span: Span,
+ hir_id: hir::HirId,
+ ) {
+ too_many_arguments::check_fn(cx, kind, decl, span, hir_id, self.too_many_arguments_threshold);
+ too_many_lines::check_fn(cx, kind, span, body, self.too_many_lines_threshold);
+ not_unsafe_ptr_arg_deref::check_fn(cx, kind, decl, body, hir_id);
+ }
+
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
+ must_use::check_item(cx, item);
+ result_unit_err::check_item(cx, item);
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::ImplItem<'_>) {
+ must_use::check_impl_item(cx, item);
+ result_unit_err::check_impl_item(cx, item);
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::TraitItem<'_>) {
+ too_many_arguments::check_trait_item(cx, item, self.too_many_arguments_threshold);
+ not_unsafe_ptr_arg_deref::check_trait_item(cx, item);
+ must_use::check_trait_item(cx, item);
+ result_unit_err::check_trait_item(cx, item);
+ }
+}
--- /dev/null
- /// // Bad
+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
- /// // Good
+ /// let x = vec![2, 3, 5];
+ /// let first_element = x.get(0);
+ /// ```
++ ///
+ /// Use instead:
+ /// ```rust
+ /// 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
- /// let end: u32 = 10;
- /// let start: u32 = 5;
- ///
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::{higher, peel_blocks_with_stmt, SpanlessEq};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind, QPath};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for implicit saturating subtraction.
+ ///
+ /// ### Why is this bad?
+ /// Simplicity and readability. Instead we can easily use an builtin function.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Bad
++ /// # let end: u32 = 10;
++ /// # let start: u32 = 5;
+ /// let mut i: u32 = end - start;
+ ///
- /// // Good
+ /// if i != 0 {
+ /// i -= 1;
+ /// }
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// # let end: u32 = 10;
++ /// # let start: u32 = 5;
++ /// let mut i: u32 = end - start;
+ ///
- // Ensure that the binary operator is >, != and <
+ /// i = i.saturating_sub(1);
+ /// ```
+ #[clippy::version = "1.44.0"]
+ pub IMPLICIT_SATURATING_SUB,
+ pedantic,
+ "Perform saturating subtraction instead of implicitly checking lower bound of data type"
+}
+
+declare_lint_pass!(ImplicitSaturatingSub => [IMPLICIT_SATURATING_SUB]);
+
+impl<'tcx> LateLintPass<'tcx> for ImplicitSaturatingSub {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
+ if expr.span.from_expansion() {
+ return;
+ }
+ if_chain! {
+ if let Some(higher::If { cond, then, r#else: None }) = higher::If::hir(expr);
+
+ // Check if the conditional expression is a binary operation
+ if let ExprKind::Binary(ref cond_op, cond_left, cond_right) = cond.kind;
+
++ // Ensure that the binary operator is >, !=, or <
+ if BinOpKind::Ne == cond_op.node || BinOpKind::Gt == cond_op.node || BinOpKind::Lt == cond_op.node;
+
+ // Check if assign operation is done
+ if let Some(target) = subtracts_one(cx, then);
+
+ // Extracting out the variable name
+ if let ExprKind::Path(QPath::Resolved(_, ares_path)) = target.kind;
+
+ then {
+ // Handle symmetric conditions in the if statement
+ let (cond_var, cond_num_val) = if SpanlessEq::new(cx).eq_expr(cond_left, target) {
+ if BinOpKind::Gt == cond_op.node || BinOpKind::Ne == cond_op.node {
+ (cond_left, cond_right)
+ } else {
+ return;
+ }
+ } else if SpanlessEq::new(cx).eq_expr(cond_right, target) {
+ if BinOpKind::Lt == cond_op.node || BinOpKind::Ne == cond_op.node {
+ (cond_right, cond_left)
+ } else {
+ return;
+ }
+ } else {
+ return;
+ };
+
+ // Check if the variable in the condition statement is an integer
+ if !cx.typeck_results().expr_ty(cond_var).is_integral() {
+ return;
+ }
+
+ // Get the variable name
+ let var_name = ares_path.segments[0].ident.name.as_str();
+ match cond_num_val.kind {
+ ExprKind::Lit(ref cond_lit) => {
+ // Check if the constant is zero
+ if let LitKind::Int(0, _) = cond_lit.node {
+ if cx.typeck_results().expr_ty(cond_left).is_signed() {
+ } else {
+ print_lint_and_sugg(cx, var_name, expr);
+ };
+ }
+ },
+ ExprKind::Path(QPath::TypeRelative(_, name)) => {
+ if_chain! {
+ if name.ident.as_str() == "MIN";
+ if let Some(const_id) = cx.typeck_results().type_dependent_def_id(cond_num_val.hir_id);
+ if let Some(impl_id) = cx.tcx.impl_of_method(const_id);
+ if let None = cx.tcx.impl_trait_ref(impl_id); // An inherent impl
+ if cx.tcx.type_of(impl_id).is_integral();
+ then {
+ print_lint_and_sugg(cx, var_name, expr)
+ }
+ }
+ },
+ ExprKind::Call(func, []) => {
+ if_chain! {
+ if let ExprKind::Path(QPath::TypeRelative(_, name)) = func.kind;
+ if name.ident.as_str() == "min_value";
+ if let Some(func_id) = cx.typeck_results().type_dependent_def_id(func.hir_id);
+ if let Some(impl_id) = cx.tcx.impl_of_method(func_id);
+ if let None = cx.tcx.impl_trait_ref(impl_id); // An inherent impl
+ if cx.tcx.type_of(impl_id).is_integral();
+ then {
+ print_lint_and_sugg(cx, var_name, expr)
+ }
+ }
+ },
+ _ => (),
+ }
+ }
+ }
+ }
+}
+
+fn subtracts_one<'a>(cx: &LateContext<'_>, expr: &'a Expr<'a>) -> Option<&'a Expr<'a>> {
+ match peel_blocks_with_stmt(expr).kind {
+ ExprKind::AssignOp(ref op1, target, value) => {
+ if_chain! {
+ if BinOpKind::Sub == op1.node;
+ // Check if literal being subtracted is one
+ if let ExprKind::Lit(ref lit1) = value.kind;
+ if let LitKind::Int(1, _) = lit1.node;
+ then {
+ Some(target)
+ } else {
+ None
+ }
+ }
+ },
+ ExprKind::Assign(target, value, _) => {
+ if_chain! {
+ if let ExprKind::Binary(ref op1, left1, right1) = value.kind;
+ if BinOpKind::Sub == op1.node;
+
+ if SpanlessEq::new(cx).eq_expr(left1, target);
+
+ if let ExprKind::Lit(ref lit1) = right1.kind;
+ if let LitKind::Int(1, _) = lit1.node;
+ then {
+ Some(target)
+ } else {
+ None
+ }
+ }
+ },
+ _ => None,
+ }
+}
+
+fn print_lint_and_sugg(cx: &LateContext<'_>, var_name: &str, expr: &Expr<'_>) {
+ span_lint_and_sugg(
+ cx,
+ IMPLICIT_SATURATING_SUB,
+ expr.span,
+ "implicitly performing saturating subtraction",
+ "try",
+ format!("{} = {}.saturating_sub({});", var_name, var_name, '1'),
+ Applicability::MachineApplicable,
+ );
+}
--- /dev/null
- #[clippy::version = "1.58.0"]
+use clippy_utils::consts::{constant, Constant};
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::higher::IfLet;
+use clippy_utils::ty::is_copy;
+use clippy_utils::{is_expn_of, is_lint_allowed, meets_msrv, msrvs, path_to_local};
+use if_chain::if_chain;
+use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::intravisit::{self, Visitor};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::nested_filter;
+use rustc_middle::ty;
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::{symbol::Ident, Span};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// The lint checks for slice bindings in patterns that are only used to
+ /// access individual slice values.
+ ///
+ /// ### Why is this bad?
+ /// Accessing slice values using indices can lead to panics. Using refutable
+ /// patterns can avoid these. Binding to individual values also improves the
+ /// readability as they can be named.
+ ///
+ /// ### Limitations
+ /// This lint currently only checks for immutable access inside `if let`
+ /// patterns.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let slice: Option<&[u32]> = Some(&[1, 2, 3]);
+ ///
+ /// if let Some(slice) = slice {
+ /// println!("{}", slice[0]);
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let slice: Option<&[u32]> = Some(&[1, 2, 3]);
+ ///
+ /// if let Some(&[first, ..]) = slice {
+ /// println!("{}", first);
+ /// }
+ /// ```
++ #[clippy::version = "1.59.0"]
+ pub INDEX_REFUTABLE_SLICE,
+ nursery,
+ "avoid indexing on slices which could be destructed"
+}
+
+#[derive(Copy, Clone)]
+pub struct IndexRefutableSlice {
+ max_suggested_slice: u64,
+ msrv: Option<RustcVersion>,
+}
+
+impl IndexRefutableSlice {
+ pub fn new(max_suggested_slice_pattern_length: u64, msrv: Option<RustcVersion>) -> Self {
+ Self {
+ max_suggested_slice: max_suggested_slice_pattern_length,
+ msrv,
+ }
+ }
+}
+
+impl_lint_pass!(IndexRefutableSlice => [INDEX_REFUTABLE_SLICE]);
+
+impl<'tcx> LateLintPass<'tcx> for IndexRefutableSlice {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
+ if_chain! {
+ if !expr.span.from_expansion() || is_expn_of(expr.span, "if_chain").is_some();
+ if let Some(IfLet {let_pat, if_then, ..}) = IfLet::hir(cx, expr);
+ if !is_lint_allowed(cx, INDEX_REFUTABLE_SLICE, expr.hir_id);
+ if meets_msrv(self.msrv, msrvs::SLICE_PATTERNS);
+
+ let found_slices = find_slice_values(cx, let_pat);
+ if !found_slices.is_empty();
+ let filtered_slices = filter_lintable_slices(cx, found_slices, self.max_suggested_slice, if_then);
+ if !filtered_slices.is_empty();
+ then {
+ for slice in filtered_slices.values() {
+ lint_slice(cx, slice);
+ }
+ }
+ }
+ }
+
+ extract_msrv_attr!(LateContext);
+}
+
+fn find_slice_values(cx: &LateContext<'_>, pat: &hir::Pat<'_>) -> FxIndexMap<hir::HirId, SliceLintInformation> {
+ let mut removed_pat: FxHashSet<hir::HirId> = FxHashSet::default();
+ let mut slices: FxIndexMap<hir::HirId, SliceLintInformation> = FxIndexMap::default();
+ pat.walk_always(|pat| {
+ if let hir::PatKind::Binding(binding, value_hir_id, ident, sub_pat) = pat.kind {
+ // We'll just ignore mut and ref mut for simplicity sake right now
+ if let hir::BindingAnnotation::Mutable | hir::BindingAnnotation::RefMut = binding {
+ return;
+ }
+
+ // This block catches bindings with sub patterns. It would be hard to build a correct suggestion
+ // for them and it's likely that the user knows what they are doing in such a case.
+ if removed_pat.contains(&value_hir_id) {
+ return;
+ }
+ if sub_pat.is_some() {
+ removed_pat.insert(value_hir_id);
+ slices.remove(&value_hir_id);
+ return;
+ }
+
+ let bound_ty = cx.typeck_results().node_type(pat.hir_id);
+ if let ty::Slice(inner_ty) | ty::Array(inner_ty, _) = bound_ty.peel_refs().kind() {
+ // The values need to use the `ref` keyword if they can't be copied.
+ // This will need to be adjusted if the lint want to support mutable access in the future
+ let src_is_ref = bound_ty.is_ref() && binding != hir::BindingAnnotation::Ref;
+ let needs_ref = !(src_is_ref || is_copy(cx, *inner_ty));
+
+ let slice_info = slices
+ .entry(value_hir_id)
+ .or_insert_with(|| SliceLintInformation::new(ident, needs_ref));
+ slice_info.pattern_spans.push(pat.span);
+ }
+ }
+ });
+
+ slices
+}
+
+fn lint_slice(cx: &LateContext<'_>, slice: &SliceLintInformation) {
+ let used_indices = slice
+ .index_use
+ .iter()
+ .map(|(index, _)| *index)
+ .collect::<FxHashSet<_>>();
+
+ let value_name = |index| format!("{}_{}", slice.ident.name, index);
+
+ if let Some(max_index) = used_indices.iter().max() {
+ let opt_ref = if slice.needs_ref { "ref " } else { "" };
+ let pat_sugg_idents = (0..=*max_index)
+ .map(|index| {
+ if used_indices.contains(&index) {
+ format!("{}{}", opt_ref, value_name(index))
+ } else {
+ "_".to_string()
+ }
+ })
+ .collect::<Vec<_>>();
+ let pat_sugg = format!("[{}, ..]", pat_sugg_idents.join(", "));
+
+ span_lint_and_then(
+ cx,
+ INDEX_REFUTABLE_SLICE,
+ slice.ident.span,
+ "this binding can be a slice pattern to avoid indexing",
+ |diag| {
+ diag.multipart_suggestion(
+ "try using a slice pattern here",
+ slice
+ .pattern_spans
+ .iter()
+ .map(|span| (*span, pat_sugg.clone()))
+ .collect(),
+ Applicability::MaybeIncorrect,
+ );
+
+ diag.multipart_suggestion(
+ "and replace the index expressions here",
+ slice
+ .index_use
+ .iter()
+ .map(|(index, span)| (*span, value_name(*index)))
+ .collect(),
+ Applicability::MaybeIncorrect,
+ );
+
+ // The lint message doesn't contain a warning about the removed index expression,
+ // since `filter_lintable_slices` will only return slices where all access indices
+ // are known at compile time. Therefore, they can be removed without side effects.
+ },
+ );
+ }
+}
+
+#[derive(Debug)]
+struct SliceLintInformation {
+ ident: Ident,
+ needs_ref: bool,
+ pattern_spans: Vec<Span>,
+ index_use: Vec<(u64, Span)>,
+}
+
+impl SliceLintInformation {
+ fn new(ident: Ident, needs_ref: bool) -> Self {
+ Self {
+ ident,
+ needs_ref,
+ pattern_spans: Vec::new(),
+ index_use: Vec::new(),
+ }
+ }
+}
+
+fn filter_lintable_slices<'a, 'tcx>(
+ cx: &'a LateContext<'tcx>,
+ slice_lint_info: FxIndexMap<hir::HirId, SliceLintInformation>,
+ max_suggested_slice: u64,
+ scope: &'tcx hir::Expr<'tcx>,
+) -> FxIndexMap<hir::HirId, SliceLintInformation> {
+ let mut visitor = SliceIndexLintingVisitor {
+ cx,
+ slice_lint_info,
+ max_suggested_slice,
+ };
+
+ intravisit::walk_expr(&mut visitor, scope);
+
+ visitor.slice_lint_info
+}
+
+struct SliceIndexLintingVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ slice_lint_info: FxIndexMap<hir::HirId, SliceLintInformation>,
+ max_suggested_slice: u64,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for SliceIndexLintingVisitor<'a, 'tcx> {
+ type NestedFilter = nested_filter::OnlyBodies;
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+
+ fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
+ if let Some(local_id) = path_to_local(expr) {
+ let Self {
+ cx,
+ ref mut slice_lint_info,
+ max_suggested_slice,
+ } = *self;
+
+ if_chain! {
+ // Check if this is even a local we're interested in
+ if let Some(use_info) = slice_lint_info.get_mut(&local_id);
+
+ let map = cx.tcx.hir();
+
+ // Checking for slice indexing
+ let parent_id = map.get_parent_node(expr.hir_id);
+ if let Some(hir::Node::Expr(parent_expr)) = map.find(parent_id);
+ if let hir::ExprKind::Index(_, index_expr) = parent_expr.kind;
+ if let Some((Constant::Int(index_value), _)) = constant(cx, cx.typeck_results(), index_expr);
+ if let Ok(index_value) = index_value.try_into();
+ if index_value < max_suggested_slice;
+
+ // Make sure that this slice index is read only
+ let maybe_addrof_id = map.get_parent_node(parent_id);
+ if let Some(hir::Node::Expr(maybe_addrof_expr)) = map.find(maybe_addrof_id);
+ if let hir::ExprKind::AddrOf(_kind, hir::Mutability::Not, _inner_expr) = maybe_addrof_expr.kind;
+ then {
+ use_info.index_use.push((index_value, map.span(parent_expr.hir_id)));
+ return;
+ }
+ }
+
+ // The slice was used for something other than indexing
+ self.slice_lint_info.remove(&local_id);
+ }
+ intravisit::walk_expr(self, expr);
+ }
+}
--- /dev/null
- /// ### Known problems
- /// Hopefully none.
- ///
+//! lint on indexing and slicing operations
+
+use clippy_utils::consts::{constant, Constant};
+use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
+use clippy_utils::higher;
+use rustc_ast::ast::RangeLimits;
+use rustc_hir::{Expr, ExprKind};
+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 out of bounds array indexing with a constant
+ /// index.
+ ///
+ /// ### Why is this bad?
+ /// This will always panic at runtime.
+ ///
- /// ```no_run
+ /// ### Example
- /// // Bad
++ /// ```rust,no_run
+ /// # #![allow(const_err)]
+ /// let x = [1, 2, 3, 4];
+ ///
- /// // Good
+ /// x[9];
+ /// &x[2..9];
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// # let x = [1, 2, 3, 4];
++ /// // Index within bounds
+ ///
- /// ### Known problems
- /// Hopefully none.
- ///
+ /// x[0];
+ /// x[3];
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub OUT_OF_BOUNDS_INDEXING,
+ correctness,
+ "out of bounds constant indexing"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of indexing or slicing. Arrays are special cases, this lint
+ /// does report on arrays if we can tell that slicing operations are in bounds and does not
+ /// lint on constant `usize` indexing on arrays because that is handled by rustc's `const_err` lint.
+ ///
+ /// ### Why is this bad?
+ /// Indexing and slicing can panic at runtime and there are
+ /// safe alternatives.
+ ///
- /// // Bad
+ /// ### Example
+ /// ```rust,no_run
+ /// // Vector
+ /// let x = vec![0; 5];
+ ///
- /// &x[2..];
- /// &x[..100];
- ///
- /// // Good
- /// x.get(2);
- /// x.get(2..100);
- /// x.get(2..);
- /// x.get(..100);
+ /// x[2];
+ /// &x[2..100];
- /// // Bad
+ ///
+ /// // Array
+ /// let y = [0, 1, 2, 3];
+ ///
- /// &y[..100];
+ /// &y[10..100];
+ /// &y[10..];
- /// // Good
- /// &y[2..];
- /// &y[..2];
- /// &y[0..3];
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// # #![allow(unused)]
++ ///
++ /// # let x = vec![0; 5];
++ /// # let y = [0, 1, 2, 3];
++ /// x.get(2);
++ /// x.get(2..100);
+ ///
- /// y.get(10..);
- /// y.get(..100);
+ /// y.get(10);
+ /// y.get(10..100);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub INDEXING_SLICING,
+ restriction,
+ "indexing/slicing usage"
+}
+
+declare_lint_pass!(IndexingSlicing => [INDEXING_SLICING, OUT_OF_BOUNDS_INDEXING]);
+
+impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if cx.tcx.hir().is_inside_const_context(expr.hir_id) {
+ return;
+ }
+
+ if let ExprKind::Index(array, index) = &expr.kind {
+ let ty = cx.typeck_results().expr_ty(array).peel_refs();
+ if let Some(range) = higher::Range::hir(index) {
+ // Ranged indexes, i.e., &x[n..m], &x[n..], &x[..n] and &x[..]
+ if let ty::Array(_, s) = ty.kind() {
+ let size: u128 = if let Some(size) = s.try_eval_usize(cx.tcx, cx.param_env) {
+ size.into()
+ } else {
+ return;
+ };
+
+ let const_range = to_const_range(cx, range, size);
+
+ if let (Some(start), _) = const_range {
+ if start > size {
+ span_lint(
+ cx,
+ OUT_OF_BOUNDS_INDEXING,
+ range.start.map_or(expr.span, |start| start.span),
+ "range is out of bounds",
+ );
+ return;
+ }
+ }
+
+ if let (_, Some(end)) = const_range {
+ if end > size {
+ span_lint(
+ cx,
+ OUT_OF_BOUNDS_INDEXING,
+ range.end.map_or(expr.span, |end| end.span),
+ "range is out of bounds",
+ );
+ return;
+ }
+ }
+
+ if let (Some(_), Some(_)) = const_range {
+ // early return because both start and end are constants
+ // and we have proven above that they are in bounds
+ return;
+ }
+ }
+
+ let help_msg = match (range.start, range.end) {
+ (None, Some(_)) => "consider using `.get(..n)`or `.get_mut(..n)` instead",
+ (Some(_), None) => "consider using `.get(n..)` or .get_mut(n..)` instead",
+ (Some(_), Some(_)) => "consider using `.get(n..m)` or `.get_mut(n..m)` instead",
+ (None, None) => return, // [..] is ok.
+ };
+
+ span_lint_and_help(cx, INDEXING_SLICING, expr.span, "slicing may panic", None, help_msg);
+ } else {
+ // Catchall non-range index, i.e., [n] or [n << m]
+ if let ty::Array(..) = ty.kind() {
+ // Index is a const block.
+ if let ExprKind::ConstBlock(..) = index.kind {
+ return;
+ }
+ // Index is a constant uint.
+ if let Some(..) = constant(cx, cx.typeck_results(), index) {
+ // Let rustc's `const_err` lint handle constant `usize` indexing on arrays.
+ return;
+ }
+ }
+
+ span_lint_and_help(
+ cx,
+ INDEXING_SLICING,
+ expr.span,
+ "indexing may panic",
+ None,
+ "consider using `.get(n)` or `.get_mut(n)` instead",
+ );
+ }
+ }
+ }
+}
+
+/// Returns a tuple of options with the start and end (exclusive) values of
+/// the range. If the start or end is not constant, None is returned.
+fn to_const_range<'tcx>(
+ cx: &LateContext<'tcx>,
+ range: higher::Range<'_>,
+ array_size: u128,
+) -> (Option<u128>, Option<u128>) {
+ let s = range
+ .start
+ .map(|expr| constant(cx, cx.typeck_results(), expr).map(|(c, _)| c));
+ let start = match s {
+ Some(Some(Constant::Int(x))) => Some(x),
+ Some(_) => None,
+ None => Some(0),
+ };
+
+ let e = range
+ .end
+ .map(|expr| constant(cx, cx.typeck_results(), expr).map(|(c, _)| c));
+ let end = match e {
+ Some(Some(Constant::Int(x))) => {
+ if range.limits == RangeLimits::Closed {
+ Some(x + 1)
+ } else {
+ Some(x)
+ }
+ },
+ Some(_) => None,
+ None => Some(array_size),
+ };
+
+ (start, end)
+}
--- /dev/null
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
+use clippy_utils::{higher, match_def_path, path_def_id, paths};
+use rustc_hir::{BorrowKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::{sym, Symbol};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for iteration that is guaranteed to be infinite.
+ ///
+ /// ### Why is this bad?
+ /// While there may be places where this is acceptable
+ /// (e.g., in event streams), in most cases this is simply an error.
+ ///
+ /// ### Example
+ /// ```no_run
+ /// use std::iter;
+ ///
+ /// iter::repeat(1_u8).collect::<Vec<_>>();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub INFINITE_ITER,
+ correctness,
+ "infinite iteration"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for iteration that may be infinite.
+ ///
+ /// ### Why is this bad?
+ /// While there may be places where this is acceptable
+ /// (e.g., in event streams), in most cases this is simply an error.
+ ///
+ /// ### Known problems
+ /// The code may have a condition to stop iteration, but
+ /// this lint is not clever enough to analyze it.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let infinite_iter = 0..;
++ /// # #[allow(unused)]
+ /// [0..].iter().zip(infinite_iter.take_while(|x| *x > 5));
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MAYBE_INFINITE_ITER,
+ pedantic,
+ "possible infinite iteration"
+}
+
+declare_lint_pass!(InfiniteIter => [INFINITE_ITER, MAYBE_INFINITE_ITER]);
+
+impl<'tcx> LateLintPass<'tcx> for InfiniteIter {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ let (lint, msg) = match complete_infinite_iter(cx, expr) {
+ Infinite => (INFINITE_ITER, "infinite iteration detected"),
+ MaybeInfinite => (MAYBE_INFINITE_ITER, "possible infinite iteration detected"),
+ Finite => {
+ return;
+ },
+ };
+ span_lint(cx, lint, expr.span, msg);
+ }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+enum Finiteness {
+ Infinite,
+ MaybeInfinite,
+ Finite,
+}
+
+use self::Finiteness::{Finite, Infinite, MaybeInfinite};
+
+impl Finiteness {
+ #[must_use]
+ fn and(self, b: Self) -> Self {
+ match (self, b) {
+ (Finite, _) | (_, Finite) => Finite,
+ (MaybeInfinite, _) | (_, MaybeInfinite) => MaybeInfinite,
+ _ => Infinite,
+ }
+ }
+
+ #[must_use]
+ fn or(self, b: Self) -> Self {
+ match (self, b) {
+ (Infinite, _) | (_, Infinite) => Infinite,
+ (MaybeInfinite, _) | (_, MaybeInfinite) => MaybeInfinite,
+ _ => Finite,
+ }
+ }
+}
+
+impl From<bool> for Finiteness {
+ #[must_use]
+ fn from(b: bool) -> Self {
+ if b { Infinite } else { Finite }
+ }
+}
+
+/// This tells us what to look for to know if the iterator returned by
+/// this method is infinite
+#[derive(Copy, Clone)]
+enum Heuristic {
+ /// infinite no matter what
+ Always,
+ /// infinite if the first argument is
+ First,
+ /// infinite if any of the supplied arguments is
+ Any,
+ /// infinite if all of the supplied arguments are
+ All,
+}
+
+use self::Heuristic::{All, Always, Any, First};
+
+/// a slice of (method name, number of args, heuristic, bounds) tuples
+/// that will be used to determine whether the method in question
+/// returns an infinite or possibly infinite iterator. The finiteness
+/// is an upper bound, e.g., some methods can return a possibly
+/// infinite iterator at worst, e.g., `take_while`.
+const HEURISTICS: [(&str, usize, Heuristic, Finiteness); 19] = [
+ ("zip", 2, All, Infinite),
+ ("chain", 2, Any, Infinite),
+ ("cycle", 1, Always, Infinite),
+ ("map", 2, First, Infinite),
+ ("by_ref", 1, First, Infinite),
+ ("cloned", 1, First, Infinite),
+ ("rev", 1, First, Infinite),
+ ("inspect", 1, First, Infinite),
+ ("enumerate", 1, First, Infinite),
+ ("peekable", 2, First, Infinite),
+ ("fuse", 1, First, Infinite),
+ ("skip", 2, First, Infinite),
+ ("skip_while", 1, First, Infinite),
+ ("filter", 2, First, Infinite),
+ ("filter_map", 2, First, Infinite),
+ ("flat_map", 2, First, Infinite),
+ ("unzip", 1, First, Infinite),
+ ("take_while", 2, First, MaybeInfinite),
+ ("scan", 3, First, MaybeInfinite),
+];
+
+fn is_infinite(cx: &LateContext<'_>, expr: &Expr<'_>) -> Finiteness {
+ match expr.kind {
+ ExprKind::MethodCall(method, args, _) => {
+ for &(name, len, heuristic, cap) in &HEURISTICS {
+ if method.ident.name.as_str() == name && args.len() == len {
+ return (match heuristic {
+ Always => Infinite,
+ First => is_infinite(cx, &args[0]),
+ Any => is_infinite(cx, &args[0]).or(is_infinite(cx, &args[1])),
+ All => is_infinite(cx, &args[0]).and(is_infinite(cx, &args[1])),
+ })
+ .and(cap);
+ }
+ }
+ if method.ident.name == sym!(flat_map) && args.len() == 2 {
+ if let ExprKind::Closure { body, .. } = args[1].kind {
+ let body = cx.tcx.hir().body(body);
+ return is_infinite(cx, &body.value);
+ }
+ }
+ Finite
+ },
+ ExprKind::Block(block, _) => block.expr.as_ref().map_or(Finite, |e| is_infinite(cx, e)),
+ ExprKind::Box(e) | ExprKind::AddrOf(BorrowKind::Ref, _, e) => is_infinite(cx, e),
+ ExprKind::Call(path, _) => path_def_id(cx, path)
+ .map_or(false, |id| match_def_path(cx, id, &paths::ITER_REPEAT))
+ .into(),
+ ExprKind::Struct(..) => higher::Range::hir(expr).map_or(false, |r| r.end.is_none()).into(),
+ _ => Finite,
+ }
+}
+
+/// the names and argument lengths of methods that *may* exhaust their
+/// iterators
+const POSSIBLY_COMPLETING_METHODS: [(&str, usize); 6] = [
+ ("find", 2),
+ ("rfind", 2),
+ ("position", 2),
+ ("rposition", 2),
+ ("any", 2),
+ ("all", 2),
+];
+
+/// the names and argument lengths of methods that *always* exhaust
+/// their iterators
+const COMPLETING_METHODS: [(&str, usize); 12] = [
+ ("count", 1),
+ ("fold", 3),
+ ("for_each", 2),
+ ("partition", 2),
+ ("max", 1),
+ ("max_by", 2),
+ ("max_by_key", 2),
+ ("min", 1),
+ ("min_by", 2),
+ ("min_by_key", 2),
+ ("sum", 1),
+ ("product", 1),
+];
+
+/// the paths of types that are known to be infinitely allocating
+const INFINITE_COLLECTORS: &[Symbol] = &[
+ sym::BinaryHeap,
+ sym::BTreeMap,
+ sym::BTreeSet,
+ sym::HashMap,
+ sym::HashSet,
+ sym::LinkedList,
+ sym::Vec,
+ sym::VecDeque,
+];
+
+fn complete_infinite_iter(cx: &LateContext<'_>, expr: &Expr<'_>) -> Finiteness {
+ match expr.kind {
+ ExprKind::MethodCall(method, args, _) => {
+ for &(name, len) in &COMPLETING_METHODS {
+ if method.ident.name.as_str() == name && args.len() == len {
+ return is_infinite(cx, &args[0]);
+ }
+ }
+ for &(name, len) in &POSSIBLY_COMPLETING_METHODS {
+ if method.ident.name.as_str() == name && args.len() == len {
+ return MaybeInfinite.and(is_infinite(cx, &args[0]));
+ }
+ }
+ if method.ident.name == sym!(last) && args.len() == 1 {
+ let not_double_ended = cx
+ .tcx
+ .get_diagnostic_item(sym::DoubleEndedIterator)
+ .map_or(false, |id| {
+ !implements_trait(cx, cx.typeck_results().expr_ty(&args[0]), id, &[])
+ });
+ if not_double_ended {
+ return is_infinite(cx, &args[0]);
+ }
+ } else if method.ident.name == sym!(collect) {
+ let ty = cx.typeck_results().expr_ty(expr);
+ if INFINITE_COLLECTORS
+ .iter()
+ .any(|diag_item| is_type_diagnostic_item(cx, ty, *diag_item))
+ {
+ return is_infinite(cx, &args[0]);
+ }
+ }
+ },
+ ExprKind::Binary(op, l, r) => {
+ if op.node.is_comparison() {
+ return is_infinite(cx, l).and(is_infinite(cx, r)).and(MaybeInfinite);
+ }
+ }, // TODO: ExprKind::Loop + Match
+ _ => (),
+ }
+ Finite
+}
--- /dev/null
- /// ### Known problems
- /// None
- ///
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
+use clippy_utils::{get_trait_def_id, paths, return_ty, trait_ref_of_method};
+use if_chain::if_chain;
+use rustc_hir::{ImplItem, ImplItemKind};
+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 the definition of inherent methods with a signature of `to_string(&self) -> String`.
+ ///
+ /// ### Why is this bad?
+ /// This method is also implicitly defined if a type implements the `Display` trait. As the functionality of `Display` is much more versatile, it should be preferred.
+ ///
- /// // Bad
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// pub struct A;
+ ///
+ /// impl A {
+ /// pub fn to_string(&self) -> String {
+ /// "I am A".to_string()
+ /// }
+ /// }
+ /// ```
+ ///
++ /// Use instead:
+ /// ```rust
- /// ### Known problems
- /// None
- ///
+ /// use std::fmt;
+ ///
+ /// pub struct A;
+ ///
+ /// impl fmt::Display for A {
+ /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ /// write!(f, "I am A")
+ /// }
+ /// }
+ /// ```
+ #[clippy::version = "1.38.0"]
+ pub INHERENT_TO_STRING,
+ style,
+ "type implements inherent method `to_string()`, but should instead implement the `Display` trait"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the definition of inherent methods with a signature of `to_string(&self) -> String` and if the type implementing this method also implements the `Display` trait.
+ ///
+ /// ### Why is this bad?
+ /// This method is also implicitly defined if a type implements the `Display` trait. The less versatile inherent method will then shadow the implementation introduced by `Display`.
+ ///
- /// // Bad
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// use std::fmt;
+ ///
+ /// pub struct A;
+ ///
+ /// impl A {
+ /// pub fn to_string(&self) -> String {
+ /// "I am A".to_string()
+ /// }
+ /// }
+ ///
+ /// impl fmt::Display for A {
+ /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ /// write!(f, "I am A, too")
+ /// }
+ /// }
+ /// ```
+ ///
++ /// Use instead:
+ /// ```rust
+ /// use std::fmt;
+ ///
+ /// pub struct A;
+ ///
+ /// impl fmt::Display for A {
+ /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ /// write!(f, "I am A")
+ /// }
+ /// }
+ /// ```
+ #[clippy::version = "1.38.0"]
+ pub INHERENT_TO_STRING_SHADOW_DISPLAY,
+ correctness,
+ "type implements inherent method `to_string()`, which gets shadowed by the implementation of the `Display` trait"
+}
+
+declare_lint_pass!(InherentToString => [INHERENT_TO_STRING, INHERENT_TO_STRING_SHADOW_DISPLAY]);
+
+impl<'tcx> LateLintPass<'tcx> for InherentToString {
+ fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx ImplItem<'_>) {
+ if impl_item.span.from_expansion() {
+ return;
+ }
+
+ if_chain! {
+ // Check if item is a method, called to_string and has a parameter 'self'
+ if let ImplItemKind::Fn(ref signature, _) = impl_item.kind;
+ if impl_item.ident.name.as_str() == "to_string";
+ let decl = &signature.decl;
+ if decl.implicit_self.has_implicit_self();
+ if decl.inputs.len() == 1;
+ if impl_item.generics.params.is_empty();
+
+ // Check if return type is String
+ if is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id()), sym::String);
+
+ // Filters instances of to_string which are required by a trait
+ if trait_ref_of_method(cx, impl_item.def_id).is_none();
+
+ then {
+ show_lint(cx, impl_item);
+ }
+ }
+ }
+}
+
+fn show_lint(cx: &LateContext<'_>, item: &ImplItem<'_>) {
+ let display_trait_id = get_trait_def_id(cx, &paths::DISPLAY_TRAIT).expect("Failed to get trait ID of `Display`!");
+
+ // Get the real type of 'self'
+ let self_type = cx.tcx.fn_sig(item.def_id).input(0);
+ let self_type = self_type.skip_binder().peel_refs();
+
+ // Emit either a warning or an error
+ if implements_trait(cx, self_type, display_trait_id, &[]) {
+ span_lint_and_help(
+ cx,
+ INHERENT_TO_STRING_SHADOW_DISPLAY,
+ item.span,
+ &format!(
+ "type `{}` implements inherent method `to_string(&self) -> String` which shadows the implementation of `Display`",
+ self_type
+ ),
+ None,
+ &format!("remove the inherent method from type `{}`", self_type),
+ );
+ } else {
+ span_lint_and_help(
+ cx,
+ INHERENT_TO_STRING,
+ item.span,
+ &format!(
+ "implementation of inherent method `to_string(&self) -> String` for type `{}`",
+ self_type
+ ),
+ None,
+ &format!("implement trait `Display` for type `{}` instead", self_type),
+ );
+ }
+}
--- /dev/null
- /// Could be written as:
- ///
+//! lint on blocks unnecessarily using >= with a + 1 or - 1
+
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_opt;
+use rustc_ast::ast::{BinOpKind, Expr, ExprKind, Lit, 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
+ /// Checks for usage of `x >= y + 1` or `x - 1 >= y` (and `<=`) in a block
+ ///
+ /// ### Why is this bad?
+ /// Readability -- better to use `> y` instead of `>= y + 1`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let x = 1;
+ /// # let y = 1;
+ /// if x >= y + 1 {}
+ /// ```
+ ///
++ /// Use instead:
+ /// ```rust
+ /// # let x = 1;
+ /// # let y = 1;
+ /// if x > y {}
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub INT_PLUS_ONE,
+ complexity,
+ "instead of using `x >= y + 1`, use `x > y`"
+}
+
+declare_lint_pass!(IntPlusOne => [INT_PLUS_ONE]);
+
+// cases:
+// BinOpKind::Ge
+// x >= y + 1
+// x - 1 >= y
+//
+// BinOpKind::Le
+// x + 1 <= y
+// x <= y - 1
+
+#[derive(Copy, Clone)]
+enum Side {
+ Lhs,
+ Rhs,
+}
+
+impl IntPlusOne {
+ #[expect(clippy::cast_sign_loss)]
+ fn check_lit(lit: &Lit, target_value: i128) -> bool {
+ if let LitKind::Int(value, ..) = lit.kind {
+ return value == (target_value as u128);
+ }
+ false
+ }
+
+ fn check_binop(cx: &EarlyContext<'_>, binop: BinOpKind, lhs: &Expr, rhs: &Expr) -> Option<String> {
+ match (binop, &lhs.kind, &rhs.kind) {
+ // case where `x - 1 >= ...` or `-1 + x >= ...`
+ (BinOpKind::Ge, &ExprKind::Binary(ref lhskind, ref lhslhs, ref lhsrhs), _) => {
+ match (lhskind.node, &lhslhs.kind, &lhsrhs.kind) {
+ // `-1 + x`
+ (BinOpKind::Add, &ExprKind::Lit(ref lit), _) if Self::check_lit(lit, -1) => {
+ Self::generate_recommendation(cx, binop, lhsrhs, rhs, Side::Lhs)
+ },
+ // `x - 1`
+ (BinOpKind::Sub, _, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, lhslhs, rhs, Side::Lhs)
+ },
+ _ => None,
+ }
+ },
+ // case where `... >= y + 1` or `... >= 1 + y`
+ (BinOpKind::Ge, _, &ExprKind::Binary(ref rhskind, ref rhslhs, ref rhsrhs))
+ if rhskind.node == BinOpKind::Add =>
+ {
+ match (&rhslhs.kind, &rhsrhs.kind) {
+ // `y + 1` and `1 + y`
+ (&ExprKind::Lit(ref lit), _) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, rhsrhs, lhs, Side::Rhs)
+ },
+ (_, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, rhslhs, lhs, Side::Rhs)
+ },
+ _ => None,
+ }
+ },
+ // case where `x + 1 <= ...` or `1 + x <= ...`
+ (BinOpKind::Le, &ExprKind::Binary(ref lhskind, ref lhslhs, ref lhsrhs), _)
+ if lhskind.node == BinOpKind::Add =>
+ {
+ match (&lhslhs.kind, &lhsrhs.kind) {
+ // `1 + x` and `x + 1`
+ (&ExprKind::Lit(ref lit), _) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, lhsrhs, rhs, Side::Lhs)
+ },
+ (_, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, lhslhs, rhs, Side::Lhs)
+ },
+ _ => None,
+ }
+ },
+ // case where `... >= y - 1` or `... >= -1 + y`
+ (BinOpKind::Le, _, &ExprKind::Binary(ref rhskind, ref rhslhs, ref rhsrhs)) => {
+ match (rhskind.node, &rhslhs.kind, &rhsrhs.kind) {
+ // `-1 + y`
+ (BinOpKind::Add, &ExprKind::Lit(ref lit), _) if Self::check_lit(lit, -1) => {
+ Self::generate_recommendation(cx, binop, rhsrhs, lhs, Side::Rhs)
+ },
+ // `y - 1`
+ (BinOpKind::Sub, _, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, rhslhs, lhs, Side::Rhs)
+ },
+ _ => None,
+ }
+ },
+ _ => None,
+ }
+ }
+
+ fn generate_recommendation(
+ cx: &EarlyContext<'_>,
+ binop: BinOpKind,
+ node: &Expr,
+ other_side: &Expr,
+ side: Side,
+ ) -> Option<String> {
+ let binop_string = match binop {
+ BinOpKind::Ge => ">",
+ BinOpKind::Le => "<",
+ _ => return None,
+ };
+ if let Some(snippet) = snippet_opt(cx, node.span) {
+ if let Some(other_side_snippet) = snippet_opt(cx, other_side.span) {
+ let rec = match side {
+ Side::Lhs => Some(format!("{} {} {}", snippet, binop_string, other_side_snippet)),
+ Side::Rhs => Some(format!("{} {} {}", other_side_snippet, binop_string, snippet)),
+ };
+ return rec;
+ }
+ }
+ None
+ }
+
+ fn emit_warning(cx: &EarlyContext<'_>, block: &Expr, recommendation: String) {
+ span_lint_and_sugg(
+ cx,
+ INT_PLUS_ONE,
+ block.span,
+ "unnecessary `>= y + 1` or `x - 1 >=`",
+ "change it to",
+ recommendation,
+ Applicability::MachineApplicable, // snippet
+ );
+ }
+}
+
+impl EarlyLintPass for IntPlusOne {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, item: &Expr) {
+ if let ExprKind::Binary(ref kind, ref lhs, ref rhs) = item.kind {
+ if let Some(rec) = Self::check_binop(cx, kind.node, lhs, rhs) {
+ Self::emit_warning(cx, item, rec);
+ }
+ }
+ }
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::span_lint_and_help;
+use if_chain::if_chain;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for division of integers
+ ///
+ /// ### Why is this bad?
+ /// When outside of some very specific algorithms,
+ /// integer division is very often a mistake because it discards the
+ /// remainder.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// let x = 3 / 2;
+ /// println!("{}", x);
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
+ /// let x = 3f32 / 2f32;
+ /// println!("{}", x);
+ /// ```
+ #[clippy::version = "1.37.0"]
+ pub INTEGER_DIVISION,
+ restriction,
+ "integer division may cause loss of precision"
+}
+
+declare_lint_pass!(IntegerDivision => [INTEGER_DIVISION]);
+
+impl<'tcx> LateLintPass<'tcx> for IntegerDivision {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
+ if is_integer_division(cx, expr) {
+ span_lint_and_help(
+ cx,
+ INTEGER_DIVISION,
+ expr.span,
+ "integer division",
+ None,
+ "division of integers may cause loss of precision. consider using floats",
+ );
+ }
+ }
+}
+
+fn is_integer_division<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) -> bool {
+ if_chain! {
+ if let hir::ExprKind::Binary(binop, left, right) = &expr.kind;
+ if binop.node == hir::BinOpKind::Div;
+ then {
+ let (left_ty, right_ty) = (cx.typeck_results().expr_ty(left), cx.typeck_results().expr_ty(right));
+ return left_ty.is_integral() && right_ty.is_integral();
+ }
+ }
+
+ false
+}
--- /dev/null
- /// // Bad
+//! lint when items are used after statements
+
+use clippy_utils::diagnostics::span_lint;
+use rustc_ast::ast::{Block, ItemKind, StmtKind};
+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 items declared after some statement in a block.
+ ///
+ /// ### Why is this bad?
+ /// Items live for the entire scope they are declared
+ /// in. But statements are processed in order. This might cause confusion as
+ /// it's hard to figure out which item is meant in a statement.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// fn foo() {
+ /// println!("cake");
+ /// }
+ ///
+ /// fn main() {
+ /// foo(); // prints "foo"
+ /// fn foo() {
+ /// println!("foo");
+ /// }
+ /// foo(); // prints "foo"
+ /// }
+ /// ```
+ ///
++ /// Use instead:
+ /// ```rust
+ /// fn foo() {
+ /// println!("cake");
+ /// }
+ ///
+ /// fn main() {
+ /// fn foo() {
+ /// println!("foo");
+ /// }
+ /// foo(); // prints "foo"
+ /// foo(); // prints "foo"
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ITEMS_AFTER_STATEMENTS,
+ pedantic,
+ "blocks where an item comes after a statement"
+}
+
+declare_lint_pass!(ItemsAfterStatements => [ITEMS_AFTER_STATEMENTS]);
+
+impl EarlyLintPass for ItemsAfterStatements {
+ fn check_block(&mut self, cx: &EarlyContext<'_>, item: &Block) {
+ if in_external_macro(cx.sess(), item.span) {
+ return;
+ }
+
+ // skip initial items and trailing semicolons
+ let stmts = item
+ .stmts
+ .iter()
+ .map(|stmt| &stmt.kind)
+ .skip_while(|s| matches!(**s, StmtKind::Item(..) | StmtKind::Empty));
+
+ // lint on all further items
+ for stmt in stmts {
+ if let StmtKind::Item(ref it) = *stmt {
+ if in_external_macro(cx.sess(), it.span) {
+ return;
+ }
+ if let ItemKind::MacroDef(..) = it.kind {
+ // do not lint `macro_rules`, but continue processing further statements
+ continue;
+ }
+ span_lint(
+ cx,
+ ITEMS_AFTER_STATEMENTS,
+ it.span,
+ "adding items after statements is confusing, since items exist from the \
+ start of the scope",
+ );
+ }
+ }
+ }
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::span_lint_and_then;
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::layout::LayoutOf;
+use rustc_middle::ty::{self, ConstKind};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::{BytePos, Pos, Span};
+use rustc_typeck::hir_ty_to_ty;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for large `const` arrays that should
+ /// be defined as `static` instead.
+ ///
+ /// ### Why is this bad?
+ /// Performance: const variables are inlined upon use.
+ /// Static items result in only one instance and has a fixed location in memory.
+ ///
+ /// ### Example
+ /// ```rust,ignore
- /// // Good
+ /// pub const a = [0u32; 1_000_000];
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust.ignore
+ /// pub static a = [0u32; 1_000_000];
+ /// ```
+ #[clippy::version = "1.44.0"]
+ pub LARGE_CONST_ARRAYS,
+ perf,
+ "large non-scalar const array may cause performance overhead"
+}
+
+pub struct LargeConstArrays {
+ maximum_allowed_size: u64,
+}
+
+impl LargeConstArrays {
+ #[must_use]
+ pub fn new(maximum_allowed_size: u64) -> Self {
+ Self { maximum_allowed_size }
+ }
+}
+
+impl_lint_pass!(LargeConstArrays => [LARGE_CONST_ARRAYS]);
+
+impl<'tcx> LateLintPass<'tcx> for LargeConstArrays {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
+ if_chain! {
+ if !item.span.from_expansion();
+ if let ItemKind::Const(hir_ty, _) = &item.kind;
+ let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+ if let ty::Array(element_type, cst) = ty.kind();
+ if let ConstKind::Value(ty::ValTree::Leaf(element_count)) = cst.kind();
+ if let Ok(element_count) = element_count.try_to_machine_usize(cx.tcx);
+ if let Ok(element_size) = cx.layout_of(*element_type).map(|l| l.size.bytes());
+ if self.maximum_allowed_size < element_count * element_size;
+
+ then {
+ let hi_pos = item.ident.span.lo() - BytePos::from_usize(1);
+ let sugg_span = Span::new(
+ hi_pos - BytePos::from_usize("const".len()),
+ hi_pos,
+ item.span.ctxt(),
+ item.span.parent(),
+ );
+ span_lint_and_then(
+ cx,
+ LARGE_CONST_ARRAYS,
+ item.span,
+ "large array defined as const",
+ |diag| {
+ diag.span_suggestion(
+ sugg_span,
+ "make this a static item",
+ "static",
+ Applicability::MachineApplicable,
+ );
+ }
+ );
+ }
+ }
+ }
+}
--- /dev/null
- /// // Bad
+//! lint when there is a large size difference between variants on an enum
+
+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
+ /// enum Test {
+ /// A(i32),
+ /// B([i32; 8000]),
+ /// }
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
+ /// // 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 {
+ 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 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
- /// Instead, you can load the file at runtime:
+use clippy_utils::diagnostics::span_lint_and_note;
+use clippy_utils::is_lint_allowed;
+use clippy_utils::macros::root_macro_call_first_node;
+use rustc_ast::LitKind;
+use rustc_hir::Expr;
+use rustc_hir::ExprKind;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the inclusion of large files via `include_bytes!()`
+ /// and `include_str!()`
+ ///
+ /// ### Why is this bad?
+ /// Including large files can increase the size of the binary
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// let included_str = include_str!("very_large_file.txt");
+ /// let included_bytes = include_bytes!("very_large_file.txt");
+ /// ```
+ ///
++ /// Use instead:
+ /// ```rust,ignore
+ /// use std::fs;
+ ///
++ /// // You can load the file at runtime
+ /// let string = fs::read_to_string("very_large_file.txt")?;
+ /// let bytes = fs::read("very_large_file.txt")?;
+ /// ```
+ #[clippy::version = "1.62.0"]
+ pub LARGE_INCLUDE_FILE,
+ restriction,
+ "including a large file"
+}
+
+pub struct LargeIncludeFile {
+ max_file_size: u64,
+}
+
+impl LargeIncludeFile {
+ #[must_use]
+ pub fn new(max_file_size: u64) -> Self {
+ Self { max_file_size }
+ }
+}
+
+impl_lint_pass!(LargeIncludeFile => [LARGE_INCLUDE_FILE]);
+
+impl LateLintPass<'_> for LargeIncludeFile {
+ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'_ Expr<'_>) {
+ if_chain! {
+ if let Some(macro_call) = root_macro_call_first_node(cx, expr);
+ if !is_lint_allowed(cx, LARGE_INCLUDE_FILE, expr.hir_id);
+ if cx.tcx.is_diagnostic_item(sym::include_bytes_macro, macro_call.def_id)
+ || cx.tcx.is_diagnostic_item(sym::include_str_macro, macro_call.def_id);
+ if let ExprKind::Lit(lit) = &expr.kind;
+ then {
+ let len = match &lit.node {
+ // include_bytes
+ LitKind::ByteStr(bstr) => bstr.len(),
+ // include_str
+ LitKind::Str(sym, _) => sym.as_str().len(),
+ _ => return,
+ };
+
+ if len as u64 <= self.max_file_size {
+ return;
+ }
+
+ span_lint_and_note(
+ cx,
+ LARGE_INCLUDE_FILE,
+ expr.span,
+ "attempted to include a large file",
+ None,
+ &format!(
+ "the configuration allows a maximum size of {} bytes",
+ self.max_file_size
+ ),
+ );
+ }
+ }
+ }
+}
--- /dev/null
- ///
- /// Bad:
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::ty::{is_must_use_ty, match_type};
+use clippy_utils::{is_must_use_func_call, paths};
+use if_chain::if_chain;
+use rustc_hir::{Local, PatKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::subst::GenericArgKind;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `let _ = <expr>` where expr is `#[must_use]`
+ ///
+ /// ### Why is this bad?
+ /// It's better to explicitly handle the value of a `#[must_use]`
+ /// expr
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn f() -> Result<u32, u32> {
+ /// Ok(0)
+ /// }
+ ///
+ /// let _ = f();
+ /// // is_ok() is marked #[must_use]
+ /// let _ = f().is_ok();
+ /// ```
+ #[clippy::version = "1.42.0"]
+ pub LET_UNDERSCORE_MUST_USE,
+ restriction,
+ "non-binding let on a `#[must_use]` expression"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `let _ = sync_lock`.
+ /// This supports `mutex` and `rwlock` in `std::sync` and `parking_lot`.
+ ///
+ /// ### Why is this bad?
+ /// This statement immediately drops the lock instead of
+ /// extending its lifetime to the end of the scope, which is often not intended.
+ /// To extend lock lifetime to the end of the scope, use an underscore-prefixed
+ /// name instead (i.e. _lock). If you want to explicitly drop the lock,
+ /// `std::mem::drop` conveys your intention better and is less error-prone.
+ ///
+ /// ### Example
- /// Good:
+ /// ```rust,ignore
+ /// let _ = mutex.lock();
+ /// ```
+ ///
- ///
- /// Bad:
- /// ```rust,ignore
- /// struct Droppable;
- /// impl Drop for Droppable {
- /// fn drop(&mut self) {}
- /// }
++ /// Use instead:
+ /// ```rust,ignore
+ /// let _lock = mutex.lock();
+ /// ```
+ #[clippy::version = "1.43.0"]
+ pub LET_UNDERSCORE_LOCK,
+ correctness,
+ "non-binding let on a synchronization lock"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `let _ = <expr>`
+ /// where expr has a type that implements `Drop`
+ ///
+ /// ### Why is this bad?
+ /// This statement immediately drops the initializer
+ /// expression instead of extending its lifetime to the end of the scope, which
+ /// is often not intended. To extend the expression's lifetime to the end of the
+ /// scope, use an underscore-prefixed name instead (i.e. _var). If you want to
+ /// explicitly drop the expression, `std::mem::drop` conveys your intention
+ /// better and is less error-prone.
+ ///
+ /// ### Example
- /// let _ = Droppable;
- /// // ^ dropped here
++ /// ```rust
++ /// # struct DroppableItem;
+ /// {
- /// Good:
- /// ```rust,ignore
++ /// let _ = DroppableItem;
++ /// // ^ dropped here
+ /// /* more code */
+ /// }
+ /// ```
+ ///
- /// let _droppable = Droppable;
++ /// Use instead:
++ /// ```rust
++ /// # struct DroppableItem;
+ /// {
++ /// let _droppable = DroppableItem;
+ /// /* more code */
+ /// // dropped at end of scope
+ /// }
+ /// ```
+ #[clippy::version = "1.50.0"]
+ pub LET_UNDERSCORE_DROP,
+ pedantic,
+ "non-binding let on a type that implements `Drop`"
+}
+
+declare_lint_pass!(LetUnderscore => [LET_UNDERSCORE_MUST_USE, LET_UNDERSCORE_LOCK, LET_UNDERSCORE_DROP]);
+
+const SYNC_GUARD_PATHS: [&[&str]; 5] = [
+ &paths::MUTEX_GUARD,
+ &paths::RWLOCK_READ_GUARD,
+ &paths::RWLOCK_WRITE_GUARD,
+ &paths::PARKING_LOT_RAWMUTEX,
+ &paths::PARKING_LOT_RAWRWLOCK,
+];
+
+impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
+ fn check_local(&mut self, cx: &LateContext<'_>, local: &Local<'_>) {
+ if in_external_macro(cx.tcx.sess, local.span) {
+ return;
+ }
+
+ if_chain! {
+ if let PatKind::Wild = local.pat.kind;
+ if let Some(init) = local.init;
+ then {
+ let init_ty = cx.typeck_results().expr_ty(init);
+ let contains_sync_guard = init_ty.walk().any(|inner| match inner.unpack() {
+ GenericArgKind::Type(inner_ty) => {
+ SYNC_GUARD_PATHS.iter().any(|path| match_type(cx, inner_ty, path))
+ },
+
+ GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
+ });
+ if contains_sync_guard {
+ span_lint_and_help(
+ cx,
+ LET_UNDERSCORE_LOCK,
+ local.span,
+ "non-binding let on a synchronization lock",
+ None,
+ "consider using an underscore-prefixed named \
+ binding or dropping explicitly with `std::mem::drop`"
+ );
+ } else if init_ty.needs_drop(cx.tcx, cx.param_env) {
+ span_lint_and_help(
+ cx,
+ LET_UNDERSCORE_DROP,
+ local.span,
+ "non-binding `let` on a type that implements `Drop`",
+ None,
+ "consider using an underscore-prefixed named \
+ binding or dropping explicitly with `std::mem::drop`"
+ );
+ } else if is_must_use_ty(cx, cx.typeck_results().expr_ty(init)) {
+ span_lint_and_help(
+ cx,
+ LET_UNDERSCORE_MUST_USE,
+ local.span,
+ "non-binding let on an expression with `#[must_use]` type",
+ None,
+ "consider explicitly using expression value"
+ );
+ } else if is_must_use_func_call(cx, init) {
+ span_lint_and_help(
+ cx,
+ LET_UNDERSCORE_MUST_USE,
+ local.span,
+ "non-binding let on a result of a `#[must_use]` function",
+ None,
+ "consider explicitly using function result"
+ );
+ }
+ }
+ }
+ }
+}
--- /dev/null
+// 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(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(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_non_exhaustive::MANUAL_NON_EXHAUSTIVE),
+ LintId::of(manual_strip::MANUAL_STRIP),
+ 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(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_parens_on_range_literals::NEEDLESS_PARENS_ON_RANGE_LITERALS),
+ 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(read_zero_byte_vec::READ_ZERO_BYTE_VEC),
+ 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
+// 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(read_zero_byte_vec::READ_ZERO_BYTE_VEC),
+ 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
+// 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,
+ 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,
+ 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,
+ 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_non_exhaustive::MANUAL_NON_EXHAUSTIVE,
+ manual_ok_or::MANUAL_OK_OR,
+ manual_strip::MANUAL_STRIP,
+ 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_result_ok::MATCH_RESULT_OK,
+ 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_parens_on_range_literals::NEEDLESS_PARENS_ON_RANGE_LITERALS,
+ 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,
++ read_zero_byte_vec::READ_ZERO_BYTE_VEC,
+ 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,
+ 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
+// 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(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(needless_parens_on_range_literals::NEEDLESS_PARENS_ON_RANGE_LITERALS),
+ 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
- // 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
++/// /// Use instead:
++/// /// ```rust
+/// /// 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 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 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 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_non_exhaustive;
+mod manual_ok_or;
+mod manual_strip;
+mod map_clone;
+mod map_err_ignore;
+mod map_unit_fn;
+mod match_result_ok;
+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_parens_on_range_literals;
+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 read_zero_byte_vec;
+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 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;
+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(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(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(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(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_late_pass(|| Box::new(needless_parens_on_range_literals::NeedlessParensOnRangeLiterals));
+ 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_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_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(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(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));
++ store.register_late_pass(|| Box::new(read_zero_byte_vec::ReadZeroByteVec));
+ // 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: unnecessary lifetime annotations
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::trait_ref_of_method;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_hir::intravisit::nested_filter::{self as hir_nested_filter, NestedFilter};
+use rustc_hir::intravisit::{
+ walk_fn_decl, walk_generic_param, walk_generics, walk_impl_item_ref, walk_item, walk_param_bound,
+ walk_poly_trait_ref, walk_trait_ref, walk_ty, Visitor,
+};
+use rustc_hir::FnRetTy::Return;
+use rustc_hir::{
+ BareFnTy, BodyId, FnDecl, GenericArg, GenericBound, GenericParam, GenericParamKind, Generics, Impl, ImplItem,
+ ImplItemKind, Item, ItemKind, LangItem, Lifetime, LifetimeName, ParamName, PolyTraitRef, PredicateOrigin,
+ TraitBoundModifier, TraitFn, TraitItem, TraitItemKind, Ty, TyKind, WherePredicate,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::nested_filter as middle_nested_filter;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use rustc_span::symbol::{kw, Ident, Symbol};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for lifetime annotations which can be removed by
+ /// relying on lifetime elision.
+ ///
+ /// ### Why is this bad?
+ /// The additional lifetimes make the code look more
+ /// complicated, while there is nothing out of the ordinary going on. Removing
+ /// them leads to more readable code.
+ ///
+ /// ### Known problems
+ /// - We bail out if the function has a `where` clause where lifetimes
+ /// are mentioned due to potential false positives.
+ /// - Lifetime bounds such as `impl Foo + 'a` and `T: 'a` must be elided with the
+ /// placeholder notation `'_` because the fully elided notation leaves the type bound to `'static`.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
++ /// // Unnecessary lifetime annotations
+ /// fn in_and_out<'a>(x: &'a u8, y: u8) -> &'a u8 {
+ /// x
+ /// }
++ /// ```
+ ///
- /// // Bad: unnecessary lifetimes
++ /// Use instead:
++ /// ```rust
+ /// fn elided(x: &u8, y: u8) -> &u8 {
+ /// x
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NEEDLESS_LIFETIMES,
+ complexity,
+ "using explicit lifetimes for references in function arguments when elision rules \
+ would allow omitting them"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for lifetimes in generics that are never used
+ /// anywhere else.
+ ///
+ /// ### Why is this bad?
+ /// The additional lifetimes make the code look more
+ /// complicated, while there is nothing out of the ordinary going on. Removing
+ /// them leads to more readable code.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
++ /// // unnecessary lifetimes
+ /// fn unused_lifetime<'a>(x: u8) {
+ /// // ..
+ /// }
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
+ /// fn no_lifetime(x: u8) {
+ /// // ...
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub EXTRA_UNUSED_LIFETIMES,
+ complexity,
+ "unused lifetimes in function definitions"
+}
+
+declare_lint_pass!(Lifetimes => [NEEDLESS_LIFETIMES, EXTRA_UNUSED_LIFETIMES]);
+
+impl<'tcx> LateLintPass<'tcx> for Lifetimes {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
+ if let ItemKind::Fn(ref sig, generics, id) = item.kind {
+ check_fn_inner(cx, sig.decl, Some(id), None, generics, item.span, true);
+ } else if let ItemKind::Impl(impl_) = item.kind {
+ report_extra_impl_lifetimes(cx, impl_);
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx ImplItem<'_>) {
+ if let ImplItemKind::Fn(ref sig, id) = item.kind {
+ let report_extra_lifetimes = trait_ref_of_method(cx, item.def_id).is_none();
+ check_fn_inner(
+ cx,
+ sig.decl,
+ Some(id),
+ None,
+ item.generics,
+ item.span,
+ report_extra_lifetimes,
+ );
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'_>) {
+ if let TraitItemKind::Fn(ref sig, ref body) = item.kind {
+ let (body, trait_sig) = match *body {
+ TraitFn::Required(sig) => (None, Some(sig)),
+ TraitFn::Provided(id) => (Some(id), None),
+ };
+ check_fn_inner(cx, sig.decl, body, trait_sig, item.generics, item.span, true);
+ }
+ }
+}
+
+/// The lifetime of a &-reference.
+#[derive(PartialEq, Eq, Hash, Debug, Clone)]
+enum RefLt {
+ Unnamed,
+ Static,
+ Named(Symbol),
+}
+
+fn check_fn_inner<'tcx>(
+ cx: &LateContext<'tcx>,
+ decl: &'tcx FnDecl<'_>,
+ body: Option<BodyId>,
+ trait_sig: Option<&[Ident]>,
+ generics: &'tcx Generics<'_>,
+ span: Span,
+ report_extra_lifetimes: bool,
+) {
+ if span.from_expansion() || has_where_lifetimes(cx, generics) {
+ return;
+ }
+
+ let types = generics
+ .params
+ .iter()
+ .filter(|param| matches!(param.kind, GenericParamKind::Type { .. }));
+ for typ in types {
+ for pred in generics.bounds_for_param(cx.tcx.hir().local_def_id(typ.hir_id)) {
+ if pred.origin == PredicateOrigin::WhereClause {
+ // has_where_lifetimes checked that this predicate contains no lifetime.
+ continue;
+ }
+
+ for bound in pred.bounds {
+ let mut visitor = RefVisitor::new(cx);
+ walk_param_bound(&mut visitor, bound);
+ if visitor.lts.iter().any(|lt| matches!(lt, RefLt::Named(_))) {
+ return;
+ }
+ if let GenericBound::Trait(ref trait_ref, _) = *bound {
+ let params = &trait_ref
+ .trait_ref
+ .path
+ .segments
+ .last()
+ .expect("a path must have at least one segment")
+ .args;
+ if let Some(params) = *params {
+ let lifetimes = params.args.iter().filter_map(|arg| match arg {
+ GenericArg::Lifetime(lt) => Some(lt),
+ _ => None,
+ });
+ for bound in lifetimes {
+ if bound.name != LifetimeName::Static && !bound.is_elided() {
+ return;
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ if could_use_elision(cx, decl, body, trait_sig, generics.params) {
+ span_lint(
+ cx,
+ NEEDLESS_LIFETIMES,
+ span.with_hi(decl.output.span().hi()),
+ "explicit lifetimes given in parameter types where they could be elided \
+ (or replaced with `'_` if needed by type declaration)",
+ );
+ }
+ if report_extra_lifetimes {
+ self::report_extra_lifetimes(cx, decl, generics);
+ }
+}
+
+// elision doesn't work for explicit self types, see rust-lang/rust#69064
+fn explicit_self_type<'tcx>(cx: &LateContext<'tcx>, func: &FnDecl<'tcx>, ident: Option<Ident>) -> bool {
+ if_chain! {
+ if let Some(ident) = ident;
+ if ident.name == kw::SelfLower;
+ if !func.implicit_self.has_implicit_self();
+
+ if let Some(self_ty) = func.inputs.first();
+ then {
+ let mut visitor = RefVisitor::new(cx);
+ visitor.visit_ty(self_ty);
+
+ !visitor.all_lts().is_empty()
+ } else {
+ false
+ }
+ }
+}
+
+fn could_use_elision<'tcx>(
+ cx: &LateContext<'tcx>,
+ func: &'tcx FnDecl<'_>,
+ body: Option<BodyId>,
+ trait_sig: Option<&[Ident]>,
+ named_generics: &'tcx [GenericParam<'_>],
+) -> bool {
+ // There are two scenarios where elision works:
+ // * no output references, all input references have different LT
+ // * output references, exactly one input reference with same LT
+ // All lifetimes must be unnamed, 'static or defined without bounds on the
+ // level of the current item.
+
+ // check named LTs
+ let allowed_lts = allowed_lts_from(named_generics);
+
+ // these will collect all the lifetimes for references in arg/return types
+ let mut input_visitor = RefVisitor::new(cx);
+ let mut output_visitor = RefVisitor::new(cx);
+
+ // extract lifetimes in input argument types
+ for arg in func.inputs {
+ input_visitor.visit_ty(arg);
+ }
+ // extract lifetimes in output type
+ if let Return(ty) = func.output {
+ output_visitor.visit_ty(ty);
+ }
+ for lt in named_generics {
+ input_visitor.visit_generic_param(lt);
+ }
+
+ if input_visitor.abort() || output_visitor.abort() {
+ return false;
+ }
+
+ if allowed_lts
+ .intersection(
+ &input_visitor
+ .nested_elision_site_lts
+ .iter()
+ .chain(output_visitor.nested_elision_site_lts.iter())
+ .cloned()
+ .filter(|v| matches!(v, RefLt::Named(_)))
+ .collect(),
+ )
+ .next()
+ .is_some()
+ {
+ return false;
+ }
+
+ let input_lts = input_visitor.lts;
+ let output_lts = output_visitor.lts;
+
+ if let Some(trait_sig) = trait_sig {
+ if explicit_self_type(cx, func, trait_sig.first().copied()) {
+ return false;
+ }
+ }
+
+ if let Some(body_id) = body {
+ let body = cx.tcx.hir().body(body_id);
+
+ let first_ident = body.params.first().and_then(|param| param.pat.simple_ident());
+ if explicit_self_type(cx, func, first_ident) {
+ return false;
+ }
+
+ let mut checker = BodyLifetimeChecker {
+ lifetimes_used_in_body: false,
+ };
+ checker.visit_expr(&body.value);
+ if checker.lifetimes_used_in_body {
+ return false;
+ }
+ }
+
+ // check for lifetimes from higher scopes
+ for lt in input_lts.iter().chain(output_lts.iter()) {
+ if !allowed_lts.contains(lt) {
+ return false;
+ }
+ }
+
+ // no input lifetimes? easy case!
+ if input_lts.is_empty() {
+ false
+ } else if output_lts.is_empty() {
+ // no output lifetimes, check distinctness of input lifetimes
+
+ // only unnamed and static, ok
+ let unnamed_and_static = input_lts.iter().all(|lt| *lt == RefLt::Unnamed || *lt == RefLt::Static);
+ if unnamed_and_static {
+ return false;
+ }
+ // we have no output reference, so we only need all distinct lifetimes
+ input_lts.len() == unique_lifetimes(&input_lts)
+ } else {
+ // we have output references, so we need one input reference,
+ // and all output lifetimes must be the same
+ if unique_lifetimes(&output_lts) > 1 {
+ return false;
+ }
+ if input_lts.len() == 1 {
+ match (&input_lts[0], &output_lts[0]) {
+ (&RefLt::Named(n1), &RefLt::Named(n2)) if n1 == n2 => true,
+ (&RefLt::Named(_), &RefLt::Unnamed) => true,
+ _ => false, /* already elided, different named lifetimes
+ * or something static going on */
+ }
+ } else {
+ false
+ }
+ }
+}
+
+fn allowed_lts_from(named_generics: &[GenericParam<'_>]) -> FxHashSet<RefLt> {
+ let mut allowed_lts = FxHashSet::default();
+ for par in named_generics.iter() {
+ if let GenericParamKind::Lifetime { .. } = par.kind {
+ allowed_lts.insert(RefLt::Named(par.name.ident().name));
+ }
+ }
+ allowed_lts.insert(RefLt::Unnamed);
+ allowed_lts.insert(RefLt::Static);
+ allowed_lts
+}
+
+/// Number of unique lifetimes in the given vector.
+#[must_use]
+fn unique_lifetimes(lts: &[RefLt]) -> usize {
+ lts.iter().collect::<FxHashSet<_>>().len()
+}
+
+const CLOSURE_TRAIT_BOUNDS: [LangItem; 3] = [LangItem::Fn, LangItem::FnMut, LangItem::FnOnce];
+
+/// A visitor usable for `rustc_front::visit::walk_ty()`.
+struct RefVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ lts: Vec<RefLt>,
+ nested_elision_site_lts: Vec<RefLt>,
+ unelided_trait_object_lifetime: bool,
+}
+
+impl<'a, 'tcx> RefVisitor<'a, 'tcx> {
+ fn new(cx: &'a LateContext<'tcx>) -> Self {
+ Self {
+ cx,
+ lts: Vec::new(),
+ nested_elision_site_lts: Vec::new(),
+ unelided_trait_object_lifetime: false,
+ }
+ }
+
+ fn record(&mut self, lifetime: &Option<Lifetime>) {
+ if let Some(ref lt) = *lifetime {
+ if lt.name == LifetimeName::Static {
+ self.lts.push(RefLt::Static);
+ } else if let LifetimeName::Param(_, ParamName::Fresh) = lt.name {
+ // Fresh lifetimes generated should be ignored.
+ } else if lt.is_elided() {
+ self.lts.push(RefLt::Unnamed);
+ } else {
+ self.lts.push(RefLt::Named(lt.name.ident().name));
+ }
+ } else {
+ self.lts.push(RefLt::Unnamed);
+ }
+ }
+
+ fn all_lts(&self) -> Vec<RefLt> {
+ self.lts
+ .iter()
+ .chain(self.nested_elision_site_lts.iter())
+ .cloned()
+ .collect::<Vec<_>>()
+ }
+
+ fn abort(&self) -> bool {
+ self.unelided_trait_object_lifetime
+ }
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for RefVisitor<'a, 'tcx> {
+ // for lifetimes as parameters of generics
+ fn visit_lifetime(&mut self, lifetime: &'tcx Lifetime) {
+ self.record(&Some(*lifetime));
+ }
+
+ fn visit_poly_trait_ref(&mut self, poly_tref: &'tcx PolyTraitRef<'tcx>, tbm: TraitBoundModifier) {
+ let trait_ref = &poly_tref.trait_ref;
+ if CLOSURE_TRAIT_BOUNDS.iter().any(|&item| {
+ self.cx
+ .tcx
+ .lang_items()
+ .require(item)
+ .map_or(false, |id| Some(id) == trait_ref.trait_def_id())
+ }) {
+ let mut sub_visitor = RefVisitor::new(self.cx);
+ sub_visitor.visit_trait_ref(trait_ref);
+ self.nested_elision_site_lts.append(&mut sub_visitor.all_lts());
+ } else {
+ walk_poly_trait_ref(self, poly_tref, tbm);
+ }
+ }
+
+ fn visit_ty(&mut self, ty: &'tcx Ty<'_>) {
+ match ty.kind {
+ TyKind::OpaqueDef(item, bounds) => {
+ let map = self.cx.tcx.hir();
+ let item = map.item(item);
+ walk_item(self, item);
+ walk_ty(self, ty);
+ self.lts.extend(bounds.iter().filter_map(|bound| match bound {
+ GenericArg::Lifetime(l) => Some(RefLt::Named(l.name.ident().name)),
+ _ => None,
+ }));
+ },
+ TyKind::BareFn(&BareFnTy { decl, .. }) => {
+ let mut sub_visitor = RefVisitor::new(self.cx);
+ sub_visitor.visit_fn_decl(decl);
+ self.nested_elision_site_lts.append(&mut sub_visitor.all_lts());
+ return;
+ },
+ TyKind::TraitObject(bounds, ref lt, _) => {
+ if !lt.is_elided() {
+ self.unelided_trait_object_lifetime = true;
+ }
+ for bound in bounds {
+ self.visit_poly_trait_ref(bound, TraitBoundModifier::None);
+ }
+ return;
+ },
+ _ => (),
+ }
+ walk_ty(self, ty);
+ }
+}
+
+/// Are any lifetimes mentioned in the `where` clause? If so, we don't try to
+/// reason about elision.
+fn has_where_lifetimes<'tcx>(cx: &LateContext<'tcx>, generics: &'tcx Generics<'_>) -> bool {
+ for predicate in generics.predicates {
+ match *predicate {
+ WherePredicate::RegionPredicate(..) => return true,
+ WherePredicate::BoundPredicate(ref pred) => {
+ // a predicate like F: Trait or F: for<'a> Trait<'a>
+ let mut visitor = RefVisitor::new(cx);
+ // walk the type F, it may not contain LT refs
+ walk_ty(&mut visitor, pred.bounded_ty);
+ if !visitor.all_lts().is_empty() {
+ return true;
+ }
+ // if the bounds define new lifetimes, they are fine to occur
+ let allowed_lts = allowed_lts_from(pred.bound_generic_params);
+ // now walk the bounds
+ for bound in pred.bounds.iter() {
+ walk_param_bound(&mut visitor, bound);
+ }
+ // and check that all lifetimes are allowed
+ if visitor.all_lts().iter().any(|it| !allowed_lts.contains(it)) {
+ return true;
+ }
+ },
+ WherePredicate::EqPredicate(ref pred) => {
+ let mut visitor = RefVisitor::new(cx);
+ walk_ty(&mut visitor, pred.lhs_ty);
+ walk_ty(&mut visitor, pred.rhs_ty);
+ if !visitor.lts.is_empty() {
+ return true;
+ }
+ },
+ }
+ }
+ false
+}
+
+struct LifetimeChecker<'cx, 'tcx, F> {
+ cx: &'cx LateContext<'tcx>,
+ map: FxHashMap<Symbol, Span>,
+ phantom: std::marker::PhantomData<F>,
+}
+
+impl<'cx, 'tcx, F> LifetimeChecker<'cx, 'tcx, F> {
+ fn new(cx: &'cx LateContext<'tcx>, map: FxHashMap<Symbol, Span>) -> LifetimeChecker<'cx, 'tcx, F> {
+ Self {
+ cx,
+ map,
+ phantom: std::marker::PhantomData,
+ }
+ }
+}
+
+impl<'cx, 'tcx, F> Visitor<'tcx> for LifetimeChecker<'cx, 'tcx, F>
+where
+ F: NestedFilter<'tcx>,
+{
+ type Map = rustc_middle::hir::map::Map<'tcx>;
+ type NestedFilter = F;
+
+ // for lifetimes as parameters of generics
+ fn visit_lifetime(&mut self, lifetime: &'tcx Lifetime) {
+ self.map.remove(&lifetime.name.ident().name);
+ }
+
+ fn visit_generic_param(&mut self, param: &'tcx GenericParam<'_>) {
+ // don't actually visit `<'a>` or `<'a: 'b>`
+ // we've already visited the `'a` declarations and
+ // don't want to spuriously remove them
+ // `'b` in `'a: 'b` is useless unless used elsewhere in
+ // a non-lifetime bound
+ if let GenericParamKind::Type { .. } = param.kind {
+ walk_generic_param(self, param);
+ }
+ }
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+}
+
+fn report_extra_lifetimes<'tcx>(cx: &LateContext<'tcx>, func: &'tcx FnDecl<'_>, generics: &'tcx Generics<'_>) {
+ let hs = generics
+ .params
+ .iter()
+ .filter_map(|par| match par.kind {
+ GenericParamKind::Lifetime { .. } => Some((par.name.ident().name, par.span)),
+ _ => None,
+ })
+ .collect();
+ let mut checker = LifetimeChecker::<hir_nested_filter::None>::new(cx, hs);
+
+ walk_generics(&mut checker, generics);
+ walk_fn_decl(&mut checker, func);
+
+ for &v in checker.map.values() {
+ span_lint(
+ cx,
+ EXTRA_UNUSED_LIFETIMES,
+ v,
+ "this lifetime isn't used in the function definition",
+ );
+ }
+}
+
+fn report_extra_impl_lifetimes<'tcx>(cx: &LateContext<'tcx>, impl_: &'tcx Impl<'_>) {
+ let hs = impl_
+ .generics
+ .params
+ .iter()
+ .filter_map(|par| match par.kind {
+ GenericParamKind::Lifetime { .. } => Some((par.name.ident().name, par.span)),
+ _ => None,
+ })
+ .collect();
+ let mut checker = LifetimeChecker::<middle_nested_filter::All>::new(cx, hs);
+
+ walk_generics(&mut checker, impl_.generics);
+ if let Some(ref trait_ref) = impl_.of_trait {
+ walk_trait_ref(&mut checker, trait_ref);
+ }
+ walk_ty(&mut checker, impl_.self_ty);
+ for item in impl_.items {
+ walk_impl_item_ref(&mut checker, item);
+ }
+
+ for &v in checker.map.values() {
+ span_lint(cx, EXTRA_UNUSED_LIFETIMES, v, "this lifetime isn't used in the impl");
+ }
+}
+
+struct BodyLifetimeChecker {
+ lifetimes_used_in_body: bool,
+}
+
+impl<'tcx> Visitor<'tcx> for BodyLifetimeChecker {
+ // for lifetimes as parameters of generics
+ fn visit_lifetime(&mut self, lifetime: &'tcx Lifetime) {
+ if lifetime.name.ident().name != kw::Empty && lifetime.name.ident().name != kw::StaticLifetime {
+ self.lifetimes_used_in_body = true;
+ }
+ }
+}
--- /dev/null
- /// // Bad
- /// let x: u64 = 61864918973511;
+//! Lints concerned with the grouping of digits with underscores in integral or
+//! floating-point literal expressions.
+
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::numeric_literal::{NumericLiteral, Radix};
+use clippy_utils::source::snippet_opt;
+use if_chain::if_chain;
+use rustc_ast::ast::{Expr, ExprKind, Lit, LitKind};
+use rustc_errors::Applicability;
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use std::iter;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns if a long integral or floating-point constant does
+ /// not contain underscores.
+ ///
+ /// ### Why is this bad?
+ /// Reading long numbers is difficult without separators.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
- /// let x: u64 = 61_864_918_973_511;
++ /// # let _: u64 =
++ /// 61864918973511
++ /// # ;
++ /// ```
+ ///
- /// // Bad
- /// let x: u64 = 618_64_9189_73_511;
++ /// Use instead:
++ /// ```rust
++ /// # let _: u64 =
++ /// 61_864_918_973_511
++ /// # ;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub UNREADABLE_LITERAL,
+ pedantic,
+ "long literal without underscores"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns for mistyped suffix in literals
+ ///
+ /// ### Why is this bad?
+ /// This is most probably a typo
+ ///
+ /// ### Known problems
+ /// - Does not match on integers too large to fit in the corresponding unsigned type
+ /// - Does not match on `_127` since that is a valid grouping for decimal and octal numbers
+ ///
+ /// ### Example
++ /// ```ignore
+ /// `2_32` => `2_i32`
+ /// `250_8 => `250_u8`
+ /// ```
+ #[clippy::version = "1.30.0"]
+ pub MISTYPED_LITERAL_SUFFIXES,
+ correctness,
+ "mistyped literal suffix"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns if an integral or floating-point constant is
+ /// grouped inconsistently with underscores.
+ ///
+ /// ### Why is this bad?
+ /// Readers may incorrectly interpret inconsistently
+ /// grouped digits.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
- /// let x: u64 = 61_864_918_973_511;
++ /// # let _: u64 =
++ /// 618_64_9189_73_511
++ /// # ;
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # let _: u64 =
++ /// 61_864_918_973_511
++ /// # ;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub INCONSISTENT_DIGIT_GROUPING,
+ style,
+ "integer literals with digits grouped inconsistently"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns if hexadecimal or binary literals are not grouped
+ /// by nibble or byte.
+ ///
+ /// ### Why is this bad?
+ /// Negatively impacts readability.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x: u32 = 0xFFF_FFF;
+ /// let y: u8 = 0b01_011_101;
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub UNUSUAL_BYTE_GROUPINGS,
+ style,
+ "binary or hex literals that aren't grouped by four"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns if the digits of an integral or floating-point
+ /// constant are grouped into groups that
+ /// are too large.
+ ///
+ /// ### Why is this bad?
+ /// Negatively impacts readability.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x: u64 = 6186491_8973511;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub LARGE_DIGIT_GROUPS,
+ pedantic,
+ "grouping digits into groups that are too large"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns if there is a better representation for a numeric literal.
+ ///
+ /// ### Why is this bad?
+ /// Especially for big powers of 2 a hexadecimal representation is more
+ /// readable than a decimal representation.
+ ///
+ /// ### Example
++ /// ```text
+ /// `255` => `0xFF`
+ /// `65_535` => `0xFFFF`
+ /// `4_042_322_160` => `0xF0F0_F0F0`
++ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DECIMAL_LITERAL_REPRESENTATION,
+ restriction,
+ "using decimal representation when hexadecimal would be better"
+}
+
+enum WarningType {
+ UnreadableLiteral,
+ InconsistentDigitGrouping,
+ LargeDigitGroups,
+ DecimalRepresentation,
+ MistypedLiteralSuffix,
+ UnusualByteGroupings,
+}
+
+impl WarningType {
+ fn display(&self, suggested_format: String, cx: &EarlyContext<'_>, span: rustc_span::Span) {
+ match self {
+ Self::MistypedLiteralSuffix => span_lint_and_sugg(
+ cx,
+ MISTYPED_LITERAL_SUFFIXES,
+ span,
+ "mistyped literal suffix",
+ "did you mean to write",
+ suggested_format,
+ Applicability::MaybeIncorrect,
+ ),
+ Self::UnreadableLiteral => span_lint_and_sugg(
+ cx,
+ UNREADABLE_LITERAL,
+ span,
+ "long literal lacking separators",
+ "consider",
+ suggested_format,
+ Applicability::MachineApplicable,
+ ),
+ Self::LargeDigitGroups => span_lint_and_sugg(
+ cx,
+ LARGE_DIGIT_GROUPS,
+ span,
+ "digit groups should be smaller",
+ "consider",
+ suggested_format,
+ Applicability::MachineApplicable,
+ ),
+ Self::InconsistentDigitGrouping => span_lint_and_sugg(
+ cx,
+ INCONSISTENT_DIGIT_GROUPING,
+ span,
+ "digits grouped inconsistently by underscores",
+ "consider",
+ suggested_format,
+ Applicability::MachineApplicable,
+ ),
+ Self::DecimalRepresentation => span_lint_and_sugg(
+ cx,
+ DECIMAL_LITERAL_REPRESENTATION,
+ span,
+ "integer literal has a better hexadecimal representation",
+ "consider",
+ suggested_format,
+ Applicability::MachineApplicable,
+ ),
+ Self::UnusualByteGroupings => span_lint_and_sugg(
+ cx,
+ UNUSUAL_BYTE_GROUPINGS,
+ span,
+ "digits of hex or binary literal not grouped by four",
+ "consider",
+ suggested_format,
+ Applicability::MachineApplicable,
+ ),
+ };
+ }
+}
+
+#[derive(Copy, Clone)]
+pub struct LiteralDigitGrouping {
+ lint_fraction_readability: bool,
+}
+
+impl_lint_pass!(LiteralDigitGrouping => [
+ UNREADABLE_LITERAL,
+ INCONSISTENT_DIGIT_GROUPING,
+ LARGE_DIGIT_GROUPS,
+ MISTYPED_LITERAL_SUFFIXES,
+ UNUSUAL_BYTE_GROUPINGS,
+]);
+
+impl EarlyLintPass for LiteralDigitGrouping {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+
+ if let ExprKind::Lit(ref lit) = expr.kind {
+ self.check_lit(cx, lit);
+ }
+ }
+}
+
+// Length of each UUID hyphenated group in hex digits.
+const UUID_GROUP_LENS: [usize; 5] = [8, 4, 4, 4, 12];
+
+impl LiteralDigitGrouping {
+ pub fn new(lint_fraction_readability: bool) -> Self {
+ Self {
+ lint_fraction_readability,
+ }
+ }
+
+ fn check_lit(self, cx: &EarlyContext<'_>, lit: &Lit) {
+ if_chain! {
+ if let Some(src) = snippet_opt(cx, lit.span);
+ if let Some(mut num_lit) = NumericLiteral::from_lit(&src, lit);
+ then {
+ if !Self::check_for_mistyped_suffix(cx, lit.span, &mut num_lit) {
+ return;
+ }
+
+ if Self::is_literal_uuid_formatted(&mut num_lit) {
+ return;
+ }
+
+ let result = (|| {
+
+ let integral_group_size = Self::get_group_size(num_lit.integer.split('_'), num_lit.radix, true)?;
+ if let Some(fraction) = num_lit.fraction {
+ let fractional_group_size = Self::get_group_size(
+ fraction.rsplit('_'),
+ num_lit.radix,
+ self.lint_fraction_readability)?;
+
+ let consistent = Self::parts_consistent(integral_group_size,
+ fractional_group_size,
+ num_lit.integer.len(),
+ fraction.len());
+ if !consistent {
+ return Err(WarningType::InconsistentDigitGrouping);
+ };
+ }
+
+ Ok(())
+ })();
+
+
+ if let Err(warning_type) = result {
+ let should_warn = match warning_type {
+ | WarningType::UnreadableLiteral
+ | WarningType::InconsistentDigitGrouping
+ | WarningType::UnusualByteGroupings
+ | WarningType::LargeDigitGroups => {
+ !lit.span.from_expansion()
+ }
+ WarningType::DecimalRepresentation | WarningType::MistypedLiteralSuffix => {
+ true
+ }
+ };
+ if should_warn {
+ warning_type.display(num_lit.format(), cx, lit.span);
+ }
+ }
+ }
+ }
+ }
+
+ // Returns `false` if the check fails
+ fn check_for_mistyped_suffix(
+ cx: &EarlyContext<'_>,
+ span: rustc_span::Span,
+ num_lit: &mut NumericLiteral<'_>,
+ ) -> bool {
+ if num_lit.suffix.is_some() {
+ return true;
+ }
+
+ let (part, mistyped_suffixes, is_float) = if let Some((_, exponent)) = &mut num_lit.exponent {
+ (exponent, &["32", "64"][..], true)
+ } else if num_lit.fraction.is_some() {
+ return true;
+ } else {
+ (&mut num_lit.integer, &["8", "16", "32", "64"][..], false)
+ };
+
+ let mut split = part.rsplit('_');
+ let last_group = split.next().expect("At least one group");
+ if split.next().is_some() && mistyped_suffixes.contains(&last_group) {
+ let main_part = &part[..part.len() - last_group.len()];
+ let missing_char;
+ if is_float {
+ missing_char = 'f';
+ } else {
+ let radix = match num_lit.radix {
+ Radix::Binary => 2,
+ Radix::Octal => 8,
+ Radix::Decimal => 10,
+ Radix::Hexadecimal => 16,
+ };
+ if let Ok(int) = u64::from_str_radix(&main_part.replace('_', ""), radix) {
+ missing_char = match (last_group, int) {
+ ("8", i) if i8::try_from(i).is_ok() => 'i',
+ ("16", i) if i16::try_from(i).is_ok() => 'i',
+ ("32", i) if i32::try_from(i).is_ok() => 'i',
+ ("64", i) if i64::try_from(i).is_ok() => 'i',
+ ("8", u) if u8::try_from(u).is_ok() => 'u',
+ ("16", u) if u16::try_from(u).is_ok() => 'u',
+ ("32", u) if u32::try_from(u).is_ok() => 'u',
+ ("64", _) => 'u',
+ _ => {
+ return true;
+ },
+ }
+ } else {
+ return true;
+ }
+ }
+ *part = main_part;
+ let mut sugg = num_lit.format();
+ sugg.push('_');
+ sugg.push(missing_char);
+ sugg.push_str(last_group);
+ WarningType::MistypedLiteralSuffix.display(sugg, cx, span);
+ false
+ } else {
+ true
+ }
+ }
+
+ /// Checks whether the numeric literal matches the formatting of a UUID.
+ ///
+ /// Returns `true` if the radix is hexadecimal, and the groups match the
+ /// UUID format of 8-4-4-4-12.
+ fn is_literal_uuid_formatted(num_lit: &mut NumericLiteral<'_>) -> bool {
+ if num_lit.radix != Radix::Hexadecimal {
+ return false;
+ }
+
+ // UUIDs should not have a fraction
+ if num_lit.fraction.is_some() {
+ return false;
+ }
+
+ let group_sizes: Vec<usize> = num_lit.integer.split('_').map(str::len).collect();
+ if UUID_GROUP_LENS.len() == group_sizes.len() {
+ iter::zip(&UUID_GROUP_LENS, &group_sizes).all(|(&a, &b)| a == b)
+ } else {
+ false
+ }
+ }
+
+ /// Given the sizes of the digit groups of both integral and fractional
+ /// parts, and the length
+ /// of both parts, determine if the digits have been grouped consistently.
+ #[must_use]
+ fn parts_consistent(
+ int_group_size: Option<usize>,
+ frac_group_size: Option<usize>,
+ int_size: usize,
+ frac_size: usize,
+ ) -> bool {
+ match (int_group_size, frac_group_size) {
+ // No groups on either side of decimal point - trivially consistent.
+ (None, None) => true,
+ // Integral part has grouped digits, fractional part does not.
+ (Some(int_group_size), None) => frac_size <= int_group_size,
+ // Fractional part has grouped digits, integral part does not.
+ (None, Some(frac_group_size)) => int_size <= frac_group_size,
+ // Both parts have grouped digits. Groups should be the same size.
+ (Some(int_group_size), Some(frac_group_size)) => int_group_size == frac_group_size,
+ }
+ }
+
+ /// Returns the size of the digit groups (or None if ungrouped) if successful,
+ /// otherwise returns a `WarningType` for linting.
+ fn get_group_size<'a>(
+ groups: impl Iterator<Item = &'a str>,
+ radix: Radix,
+ lint_unreadable: bool,
+ ) -> Result<Option<usize>, WarningType> {
+ let mut groups = groups.map(str::len);
+
+ let first = groups.next().expect("At least one group");
+
+ if (radix == Radix::Binary || radix == Radix::Hexadecimal) && groups.any(|i| i != 4 && i != 2) {
+ return Err(WarningType::UnusualByteGroupings);
+ }
+
+ if let Some(second) = groups.next() {
+ if !groups.all(|x| x == second) || first > second {
+ Err(WarningType::InconsistentDigitGrouping)
+ } else if second > 4 {
+ Err(WarningType::LargeDigitGroups)
+ } else {
+ Ok(Some(second))
+ }
+ } else if first > 5 && lint_unreadable {
+ Err(WarningType::UnreadableLiteral)
+ } else {
+ Ok(None)
+ }
+ }
+}
+
+#[expect(clippy::module_name_repetitions)]
+#[derive(Copy, Clone)]
+pub struct DecimalLiteralRepresentation {
+ threshold: u64,
+}
+
+impl_lint_pass!(DecimalLiteralRepresentation => [DECIMAL_LITERAL_REPRESENTATION]);
+
+impl EarlyLintPass for DecimalLiteralRepresentation {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+
+ if let ExprKind::Lit(ref lit) = expr.kind {
+ self.check_lit(cx, lit);
+ }
+ }
+}
+
+impl DecimalLiteralRepresentation {
+ #[must_use]
+ pub fn new(threshold: u64) -> Self {
+ Self { threshold }
+ }
+ fn check_lit(self, cx: &EarlyContext<'_>, lit: &Lit) {
+ // Lint integral literals.
+ if_chain! {
+ if let LitKind::Int(val, _) = lit.kind;
+ if let Some(src) = snippet_opt(cx, lit.span);
+ if let Some(num_lit) = NumericLiteral::from_lit(&src, lit);
+ if num_lit.radix == Radix::Decimal;
+ if val >= u128::from(self.threshold);
+ then {
+ let hex = format!("{:#X}", val);
+ let num_lit = NumericLiteral::new(&hex, num_lit.suffix, false);
+ let _ = Self::do_lint(num_lit.integer).map_err(|warning_type| {
+ warning_type.display(num_lit.format(), cx, lit.span);
+ });
+ }
+ }
+ }
+
+ fn do_lint(digits: &str) -> Result<(), WarningType> {
+ if digits.len() == 1 {
+ // Lint for 1 digit literals, if someone really sets the threshold that low
+ if digits == "1"
+ || digits == "2"
+ || digits == "4"
+ || digits == "8"
+ || digits == "3"
+ || digits == "7"
+ || digits == "F"
+ {
+ return Err(WarningType::DecimalRepresentation);
+ }
+ } else if digits.len() < 4 {
+ // Lint for Literals with a hex-representation of 2 or 3 digits
+ let f = &digits[0..1]; // first digit
+ let s = &digits[1..]; // suffix
+
+ // Powers of 2
+ if ((f.eq("1") || f.eq("2") || f.eq("4") || f.eq("8")) && s.chars().all(|c| c == '0'))
+ // Powers of 2 minus 1
+ || ((f.eq("1") || f.eq("3") || f.eq("7") || f.eq("F")) && s.chars().all(|c| c == 'F'))
+ {
+ return Err(WarningType::DecimalRepresentation);
+ }
+ } else {
+ // Lint for Literals with a hex-representation of 4 digits or more
+ let f = &digits[0..1]; // first digit
+ let m = &digits[1..digits.len() - 1]; // middle digits, except last
+ let s = &digits[1..]; // suffix
+
+ // Powers of 2 with a margin of +15/-16
+ if ((f.eq("1") || f.eq("2") || f.eq("4") || f.eq("8")) && m.chars().all(|c| c == '0'))
+ || ((f.eq("1") || f.eq("3") || f.eq("7") || f.eq("F")) && m.chars().all(|c| c == 'F'))
+ // Lint for representations with only 0s and Fs, while allowing 7 as the first
+ // digit
+ || ((f.eq("7") || f.eq("F")) && s.chars().all(|c| c == '0' || c == 'F'))
+ {
+ return Err(WarningType::DecimalRepresentation);
+ }
+ }
+
+ Ok(())
+ }
+}
--- /dev/null
- pub(super) fn check(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>) {
+use super::FOR_LOOPS_OVER_FALLIBLES;
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::source::snippet;
+use clippy_utils::ty::is_type_diagnostic_item;
+use rustc_hir::{Expr, Pat};
+use rustc_lint::LateContext;
+use rustc_span::symbol::sym;
+
+/// Checks for `for` loops over `Option`s and `Result`s.
- &format!(
- "consider replacing `for {0} in {1}` with `if let Some({0}) = {1}`",
- snippet(cx, pat.span, "_"),
- snippet(cx, arg.span, "_")
- ),
++pub(super) fn check(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>, method_name: Option<&str>) {
+ let ty = cx.typeck_results().expr_ty(arg);
+ if is_type_diagnostic_item(cx, ty, sym::Option) {
++ let help_string = if let Some(method_name) = method_name {
++ format!(
++ "consider replacing `for {0} in {1}.{method_name}()` with `if let Some({0}) = {1}`",
++ snippet(cx, pat.span, "_"),
++ snippet(cx, arg.span, "_")
++ )
++ } else {
++ format!(
++ "consider replacing `for {0} in {1}` with `if let Some({0}) = {1}`",
++ snippet(cx, pat.span, "_"),
++ snippet(cx, arg.span, "_")
++ )
++ };
+ span_lint_and_help(
+ cx,
+ FOR_LOOPS_OVER_FALLIBLES,
+ arg.span,
+ &format!(
+ "for loop over `{0}`, which is an `Option`. This is more readably written as an \
+ `if let` statement",
+ snippet(cx, arg.span, "_")
+ ),
+ None,
- &format!(
- "consider replacing `for {0} in {1}` with `if let Ok({0}) = {1}`",
- snippet(cx, pat.span, "_"),
- snippet(cx, arg.span, "_")
- ),
++ &help_string,
+ );
+ } else if is_type_diagnostic_item(cx, ty, sym::Result) {
++ let help_string = if let Some(method_name) = method_name {
++ format!(
++ "consider replacing `for {0} in {1}.{method_name}()` with `if let Ok({0}) = {1}`",
++ snippet(cx, pat.span, "_"),
++ snippet(cx, arg.span, "_")
++ )
++ } else {
++ format!(
++ "consider replacing `for {0} in {1}` with `if let Ok({0}) = {1}`",
++ snippet(cx, pat.span, "_"),
++ snippet(cx, arg.span, "_")
++ )
++ };
+ span_lint_and_help(
+ cx,
+ FOR_LOOPS_OVER_FALLIBLES,
+ arg.span,
+ &format!(
+ "for loop over `{0}`, which is a `Result`. This is more readably written as an \
+ `if let` statement",
+ snippet(cx, arg.span, "_")
+ ),
+ None,
++ &help_string,
+ );
+ }
+}
--- /dev/null
- /// Could be written as:
+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:
++ ///
++ /// Use instead:
+ /// ```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]);
+ /// }
+ /// ```
- /// can be rewritten to
++ ///
++ /// Use instead:
+ /// ```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() {
+ /// // ..
+ /// }
+ /// ```
- /// Could be written as
++ ///
++ /// Use instead:
+ /// ```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);
+ /// # let res: Result<i32, std::io::Error> = Ok(1);
+ /// for x in opt {
+ /// // ..
+ /// }
+ ///
+ /// for x in &res {
+ /// // ..
+ /// }
++ ///
++ /// for x in res.iter() {
++ /// // ..
++ /// }
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// # let opt = Some(1);
+ /// # let res: Result<i32, std::io::Error> = Ok(1);
+ /// 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;
+ /// }
+ /// ```
- /// `vec![item;SIZE]` or `vec.resize(NEW_SIZE, item)` and using these alternatives may also
++ ///
++ /// Use instead:
+ /// ```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
- /// could be written as
++ /// `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
++ ///
++ /// Use instead:
+ /// ```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);
+ /// }
+ /// ```
- #[clippy::version = "1.59.0"]
++ ///
++ /// Use instead:
+ /// ```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()
+ /// }
+ /// ```
- "iter" | "iter_mut" => explicit_iter_loop::check(cx, self_arg, arg, method_name),
++ #[clippy::version = "1.61.0"]
+ 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 {
- for_loops_over_fallibles::check(cx, pat, arg);
++ "iter" | "iter_mut" => {
++ explicit_iter_loop::check(cx, self_arg, arg, method_name);
++ for_loops_over_fallibles::check(cx, pat, self_arg, Some(method_name));
++ },
+ "into_iter" => {
+ explicit_iter_loop::check(cx, self_arg, arg, method_name);
+ explicit_into_iter_loop::check(cx, self_arg, arg);
++ for_loops_over_fallibles::check(cx, pat, self_arg, Some(method_name));
+ },
+ "next" => {
+ next_loop_linted = iter_next_loop::check(cx, arg);
+ },
+ _ => {},
+ }
+ }
+
+ if !next_loop_linted {
++ for_loops_over_fallibles::check(cx, pat, arg, None);
+ }
+}
--- /dev/null
- | ExprKind::Struct(_, _, Some(e))
+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(_, _, None)
- | ExprKind::Yield(_, _)
+ | 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::Struct(_, fields, base) => {
++ let fields = never_loop_expr_all(&mut fields.iter().map(|f| f.expr), main_loop_id);
++ if let Some(base) = base {
++ combine_both(fields, never_loop_expr(base, main_loop_id))
++ } else {
++ fields
++ }
++ },
+ 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::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
- diag.span_suggestion(
- arm1.span,
- "try removing the arm",
- "",
- Applicability::MaybeIncorrect,
- )
- .help("or try changing either arm body")
- .span_note(arm2.span, "`_` wildcard arm here");
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::source::snippet;
+use clippy_utils::{path_to_local, search_same, SpanlessEq, SpanlessHash};
+use core::cmp::Ordering;
+use core::iter;
+use core::slice;
+use rustc_arena::DroplessArena;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::def_id::DefId;
+use rustc_hir::{Arm, Expr, ExprKind, HirId, HirIdMap, HirIdSet, Pat, PatKind, RangeEnd};
+use rustc_lint::LateContext;
+use rustc_middle::ty;
+use rustc_span::Symbol;
+use std::collections::hash_map::Entry;
+
+use super::MATCH_SAME_ARMS;
+
+#[expect(clippy::too_many_lines)]
+pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>]) {
+ let hash = |&(_, arm): &(usize, &Arm<'_>)| -> u64 {
+ let mut h = SpanlessHash::new(cx);
+ h.hash_expr(arm.body);
+ h.finish()
+ };
+
+ let arena = DroplessArena::default();
+ let normalized_pats: Vec<_> = arms
+ .iter()
+ .map(|a| NormalizedPat::from_pat(cx, &arena, a.pat))
+ .collect();
+
+ // The furthest forwards a pattern can move without semantic changes
+ let forwards_blocking_idxs: Vec<_> = normalized_pats
+ .iter()
+ .enumerate()
+ .map(|(i, pat)| {
+ normalized_pats[i + 1..]
+ .iter()
+ .enumerate()
+ .find_map(|(j, other)| pat.has_overlapping_values(other).then(|| i + 1 + j))
+ .unwrap_or(normalized_pats.len())
+ })
+ .collect();
+
+ // The furthest backwards a pattern can move without semantic changes
+ let backwards_blocking_idxs: Vec<_> = normalized_pats
+ .iter()
+ .enumerate()
+ .map(|(i, pat)| {
+ normalized_pats[..i]
+ .iter()
+ .enumerate()
+ .rev()
+ .zip(forwards_blocking_idxs[..i].iter().copied().rev())
+ .skip_while(|&(_, forward_block)| forward_block > i)
+ .find_map(|((j, other), forward_block)| {
+ (forward_block == i || pat.has_overlapping_values(other)).then(|| j)
+ })
+ .unwrap_or(0)
+ })
+ .collect();
+
+ let eq = |&(lindex, lhs): &(usize, &Arm<'_>), &(rindex, rhs): &(usize, &Arm<'_>)| -> bool {
+ let min_index = usize::min(lindex, rindex);
+ let max_index = usize::max(lindex, rindex);
+
+ let mut local_map: HirIdMap<HirId> = HirIdMap::default();
+ let eq_fallback = |a: &Expr<'_>, b: &Expr<'_>| {
+ if_chain! {
+ if let Some(a_id) = path_to_local(a);
+ if let Some(b_id) = path_to_local(b);
+ let entry = match local_map.entry(a_id) {
+ Entry::Vacant(entry) => entry,
+ // check if using the same bindings as before
+ Entry::Occupied(entry) => return *entry.get() == b_id,
+ };
+ // the names technically don't have to match; this makes the lint more conservative
+ if cx.tcx.hir().name(a_id) == cx.tcx.hir().name(b_id);
+ if cx.typeck_results().expr_ty(a) == cx.typeck_results().expr_ty(b);
+ if pat_contains_local(lhs.pat, a_id);
+ if pat_contains_local(rhs.pat, b_id);
+ then {
+ entry.insert(b_id);
+ true
+ } else {
+ false
+ }
+ }
+ };
+ // Arms with a guard are ignored, those can’t always be merged together
+ // If both arms overlap with an arm in between then these can't be merged either.
+ !(backwards_blocking_idxs[max_index] > min_index && forwards_blocking_idxs[min_index] < max_index)
+ && lhs.guard.is_none()
+ && rhs.guard.is_none()
+ && SpanlessEq::new(cx)
+ .expr_fallback(eq_fallback)
+ .eq_expr(lhs.body, rhs.body)
+ // these checks could be removed to allow unused bindings
+ && bindings_eq(lhs.pat, local_map.keys().copied().collect())
+ && bindings_eq(rhs.pat, local_map.values().copied().collect())
+ };
+
+ let indexed_arms: Vec<(usize, &Arm<'_>)> = arms.iter().enumerate().collect();
+ for (&(i, arm1), &(j, arm2)) in search_same(&indexed_arms, hash, eq) {
+ if matches!(arm2.pat.kind, PatKind::Wild) {
+ span_lint_and_then(
+ cx,
+ MATCH_SAME_ARMS,
+ arm1.span,
+ "this match arm has an identical body to the `_` wildcard arm",
+ |diag| {
++ diag.span_suggestion(arm1.span, "try removing the arm", "", Applicability::MaybeIncorrect)
++ .help("or try changing either arm body")
++ .span_note(arm2.span, "`_` wildcard arm here");
+ },
+ );
+ } else {
+ let back_block = backwards_blocking_idxs[j];
+ let (keep_arm, move_arm) = if back_block < i || (back_block == 0 && forwards_blocking_idxs[i] <= j) {
+ (arm1, arm2)
+ } else {
+ (arm2, arm1)
+ };
+
+ span_lint_and_then(
+ cx,
+ MATCH_SAME_ARMS,
+ keep_arm.span,
+ "this match arm has an identical body to another arm",
+ |diag| {
+ let move_pat_snip = snippet(cx, move_arm.pat.span, "<pat2>");
+ let keep_pat_snip = snippet(cx, keep_arm.pat.span, "<pat1>");
+
+ diag.span_suggestion(
+ keep_arm.pat.span,
+ "try merging the arm patterns",
+ format!("{} | {}", keep_pat_snip, move_pat_snip),
+ Applicability::MaybeIncorrect,
+ )
+ .help("or try changing either arm body")
+ .span_note(move_arm.span, "other arm here");
+ },
+ );
+ }
+ }
+}
+
+#[derive(Clone, Copy)]
+enum NormalizedPat<'a> {
+ Wild,
+ Struct(Option<DefId>, &'a [(Symbol, Self)]),
+ Tuple(Option<DefId>, &'a [Self]),
+ Or(&'a [Self]),
+ Path(Option<DefId>),
+ LitStr(Symbol),
+ LitBytes(&'a [u8]),
+ LitInt(u128),
+ LitBool(bool),
+ Range(PatRange),
+ /// A slice pattern. If the second value is `None`, then this matches an exact size. Otherwise
+ /// the first value contains everything before the `..` wildcard pattern, and the second value
+ /// contains everything afterwards. Note that either side, or both sides, may contain zero
+ /// patterns.
+ Slice(&'a [Self], Option<&'a [Self]>),
+}
+
+#[derive(Clone, Copy)]
+struct PatRange {
+ start: u128,
+ end: u128,
+ bounds: RangeEnd,
+}
+impl PatRange {
+ fn contains(&self, x: u128) -> bool {
+ x >= self.start
+ && match self.bounds {
+ RangeEnd::Included => x <= self.end,
+ RangeEnd::Excluded => x < self.end,
+ }
+ }
+
+ fn overlaps(&self, other: &Self) -> bool {
+ // Note: Empty ranges are impossible, so this is correct even though it would return true if an
+ // empty exclusive range were to reside within an inclusive range.
+ (match self.bounds {
+ RangeEnd::Included => self.end >= other.start,
+ RangeEnd::Excluded => self.end > other.start,
+ } && match other.bounds {
+ RangeEnd::Included => self.start <= other.end,
+ RangeEnd::Excluded => self.start < other.end,
+ })
+ }
+}
+
+/// Iterates over the pairs of fields with matching names.
+fn iter_matching_struct_fields<'a>(
+ left: &'a [(Symbol, NormalizedPat<'a>)],
+ right: &'a [(Symbol, NormalizedPat<'a>)],
+) -> impl Iterator<Item = (&'a NormalizedPat<'a>, &'a NormalizedPat<'a>)> + 'a {
+ struct Iter<'a>(
+ slice::Iter<'a, (Symbol, NormalizedPat<'a>)>,
+ slice::Iter<'a, (Symbol, NormalizedPat<'a>)>,
+ );
+ impl<'a> Iterator for Iter<'a> {
+ type Item = (&'a NormalizedPat<'a>, &'a NormalizedPat<'a>);
+ fn next(&mut self) -> Option<Self::Item> {
+ // Note: all the fields in each slice are sorted by symbol value.
+ let mut left = self.0.next()?;
+ let mut right = self.1.next()?;
+ loop {
+ match left.0.cmp(&right.0) {
+ Ordering::Equal => return Some((&left.1, &right.1)),
+ Ordering::Less => left = self.0.next()?,
+ Ordering::Greater => right = self.1.next()?,
+ }
+ }
+ }
+ }
+ Iter(left.iter(), right.iter())
+}
+
+#[expect(clippy::similar_names)]
+impl<'a> NormalizedPat<'a> {
+ #[expect(clippy::too_many_lines)]
+ fn from_pat(cx: &LateContext<'_>, arena: &'a DroplessArena, pat: &'a Pat<'_>) -> Self {
+ match pat.kind {
+ PatKind::Wild | PatKind::Binding(.., None) => Self::Wild,
+ PatKind::Binding(.., Some(pat)) | PatKind::Box(pat) | PatKind::Ref(pat, _) => {
+ Self::from_pat(cx, arena, pat)
+ },
+ PatKind::Struct(ref path, fields, _) => {
+ let fields =
+ arena.alloc_from_iter(fields.iter().map(|f| (f.ident.name, Self::from_pat(cx, arena, f.pat))));
+ fields.sort_by_key(|&(name, _)| name);
+ Self::Struct(cx.qpath_res(path, pat.hir_id).opt_def_id(), fields)
+ },
+ PatKind::TupleStruct(ref path, pats, wild_idx) => {
+ let adt = match cx.typeck_results().pat_ty(pat).ty_adt_def() {
+ Some(x) => x,
+ None => return Self::Wild,
+ };
+ let (var_id, variant) = if adt.is_enum() {
+ match cx.qpath_res(path, pat.hir_id).opt_def_id() {
+ Some(x) => (Some(x), adt.variant_with_ctor_id(x)),
+ None => return Self::Wild,
+ }
+ } else {
+ (None, adt.non_enum_variant())
+ };
+ let (front, back) = match wild_idx {
+ Some(i) => pats.split_at(i),
+ None => (pats, [].as_slice()),
+ };
+ let pats = arena.alloc_from_iter(
+ front
+ .iter()
+ .map(|pat| Self::from_pat(cx, arena, pat))
+ .chain(iter::repeat_with(|| Self::Wild).take(variant.fields.len() - pats.len()))
+ .chain(back.iter().map(|pat| Self::from_pat(cx, arena, pat))),
+ );
+ Self::Tuple(var_id, pats)
+ },
+ PatKind::Or(pats) => Self::Or(arena.alloc_from_iter(pats.iter().map(|pat| Self::from_pat(cx, arena, pat)))),
+ PatKind::Path(ref path) => Self::Path(cx.qpath_res(path, pat.hir_id).opt_def_id()),
+ PatKind::Tuple(pats, wild_idx) => {
+ let field_count = match cx.typeck_results().pat_ty(pat).kind() {
+ ty::Tuple(subs) => subs.len(),
+ _ => return Self::Wild,
+ };
+ let (front, back) = match wild_idx {
+ Some(i) => pats.split_at(i),
+ None => (pats, [].as_slice()),
+ };
+ let pats = arena.alloc_from_iter(
+ front
+ .iter()
+ .map(|pat| Self::from_pat(cx, arena, pat))
+ .chain(iter::repeat_with(|| Self::Wild).take(field_count - pats.len()))
+ .chain(back.iter().map(|pat| Self::from_pat(cx, arena, pat))),
+ );
+ Self::Tuple(None, pats)
+ },
+ PatKind::Lit(e) => match &e.kind {
+ // TODO: Handle negative integers. They're currently treated as a wild match.
+ ExprKind::Lit(lit) => match lit.node {
+ LitKind::Str(sym, _) => Self::LitStr(sym),
+ LitKind::ByteStr(ref bytes) => Self::LitBytes(&**bytes),
+ LitKind::Byte(val) => Self::LitInt(val.into()),
+ LitKind::Char(val) => Self::LitInt(val.into()),
+ LitKind::Int(val, _) => Self::LitInt(val),
+ LitKind::Bool(val) => Self::LitBool(val),
+ LitKind::Float(..) | LitKind::Err(_) => Self::Wild,
+ },
+ _ => Self::Wild,
+ },
+ PatKind::Range(start, end, bounds) => {
+ // TODO: Handle negative integers. They're currently treated as a wild match.
+ let start = match start {
+ None => 0,
+ Some(e) => match &e.kind {
+ ExprKind::Lit(lit) => match lit.node {
+ LitKind::Int(val, _) => val,
+ LitKind::Char(val) => val.into(),
+ LitKind::Byte(val) => val.into(),
+ _ => return Self::Wild,
+ },
+ _ => return Self::Wild,
+ },
+ };
+ let (end, bounds) = match end {
+ None => (u128::MAX, RangeEnd::Included),
+ Some(e) => match &e.kind {
+ ExprKind::Lit(lit) => match lit.node {
+ LitKind::Int(val, _) => (val, bounds),
+ LitKind::Char(val) => (val.into(), bounds),
+ LitKind::Byte(val) => (val.into(), bounds),
+ _ => return Self::Wild,
+ },
+ _ => return Self::Wild,
+ },
+ };
+ Self::Range(PatRange { start, end, bounds })
+ },
+ PatKind::Slice(front, wild_pat, back) => Self::Slice(
+ arena.alloc_from_iter(front.iter().map(|pat| Self::from_pat(cx, arena, pat))),
+ wild_pat.map(|_| &*arena.alloc_from_iter(back.iter().map(|pat| Self::from_pat(cx, arena, pat)))),
+ ),
+ }
+ }
+
+ /// Checks if two patterns overlap in the values they can match assuming they are for the same
+ /// type.
+ fn has_overlapping_values(&self, other: &Self) -> bool {
+ match (*self, *other) {
+ (Self::Wild, _) | (_, Self::Wild) => true,
+ (Self::Or(pats), ref other) | (ref other, Self::Or(pats)) => {
+ pats.iter().any(|pat| pat.has_overlapping_values(other))
+ },
+ (Self::Struct(lpath, lfields), Self::Struct(rpath, rfields)) => {
+ if lpath != rpath {
+ return false;
+ }
+ iter_matching_struct_fields(lfields, rfields).all(|(lpat, rpat)| lpat.has_overlapping_values(rpat))
+ },
+ (Self::Tuple(lpath, lpats), Self::Tuple(rpath, rpats)) => {
+ if lpath != rpath {
+ return false;
+ }
+ lpats
+ .iter()
+ .zip(rpats.iter())
+ .all(|(lpat, rpat)| lpat.has_overlapping_values(rpat))
+ },
+ (Self::Path(x), Self::Path(y)) => x == y,
+ (Self::LitStr(x), Self::LitStr(y)) => x == y,
+ (Self::LitBytes(x), Self::LitBytes(y)) => x == y,
+ (Self::LitInt(x), Self::LitInt(y)) => x == y,
+ (Self::LitBool(x), Self::LitBool(y)) => x == y,
+ (Self::Range(ref x), Self::Range(ref y)) => x.overlaps(y),
+ (Self::Range(ref range), Self::LitInt(x)) | (Self::LitInt(x), Self::Range(ref range)) => range.contains(x),
+ (Self::Slice(lpats, None), Self::Slice(rpats, None)) => {
+ lpats.len() == rpats.len() && lpats.iter().zip(rpats.iter()).all(|(x, y)| x.has_overlapping_values(y))
+ },
+ (Self::Slice(pats, None), Self::Slice(front, Some(back)))
+ | (Self::Slice(front, Some(back)), Self::Slice(pats, None)) => {
+ // Here `pats` is an exact size match. If the combined lengths of `front` and `back` are greater
+ // then the minium length required will be greater than the length of `pats`.
+ if pats.len() < front.len() + back.len() {
+ return false;
+ }
+ pats[..front.len()]
+ .iter()
+ .zip(front.iter())
+ .chain(pats[pats.len() - back.len()..].iter().zip(back.iter()))
+ .all(|(x, y)| x.has_overlapping_values(y))
+ },
+ (Self::Slice(lfront, Some(lback)), Self::Slice(rfront, Some(rback))) => lfront
+ .iter()
+ .zip(rfront.iter())
+ .chain(lback.iter().rev().zip(rback.iter().rev()))
+ .all(|(x, y)| x.has_overlapping_values(y)),
+
+ // Enums can mix unit variants with tuple/struct variants. These can never overlap.
+ (Self::Path(_), Self::Tuple(..) | Self::Struct(..))
+ | (Self::Tuple(..) | Self::Struct(..), Self::Path(_)) => false,
+
+ // Tuples can be matched like a struct.
+ (Self::Tuple(x, _), Self::Struct(y, _)) | (Self::Struct(x, _), Self::Tuple(y, _)) => {
+ // TODO: check fields here.
+ x == y
+ },
+
+ // TODO: Lit* with Path, Range with Path, LitBytes with Slice
+ _ => true,
+ }
+ }
+}
+
+fn pat_contains_local(pat: &Pat<'_>, id: HirId) -> bool {
+ let mut result = false;
+ pat.walk_short(|p| {
+ result |= matches!(p.kind, PatKind::Binding(_, binding_id, ..) if binding_id == id);
+ !result
+ });
+ result
+}
+
+/// Returns true if all the bindings in the `Pat` are in `ids` and vice versa
+fn bindings_eq(pat: &Pat<'_>, mut ids: HirIdSet) -> bool {
+ let mut result = true;
+ pat.each_binding_or_first(&mut |_, id, _, _| result &= ids.remove(&id));
+ result && ids.is_empty()
+}
--- /dev/null
- /// // Bad
+use clippy_utils::source::{snippet_opt, span_starts_with, walk_span_to_context};
+use clippy_utils::{higher, in_constant, meets_msrv, msrvs};
+use rustc_hir::{Arm, Expr, ExprKind, Local, MatchSource, Pat};
+use rustc_lexer::{tokenize, TokenKind};
+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");
- /// // Good
+ /// match x {
+ /// Some(ref foo) => bar(foo),
+ /// _ => (),
+ /// }
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # fn bar(stool: &str) {}
++ /// # let x = Some("abc");
+ /// 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
- /// // Good
+ /// match x {
+ /// &A(ref y) => foo(y),
+ /// &B => bar(),
+ /// _ => frob(&x),
+ /// }
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust,ignore
+ /// 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;
+ ///
- /// // Good
+ /// let r: Option<&()> = match x {
+ /// None => None,
+ /// Some(ref v) => Some(v),
+ /// };
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// let x: Option<()> = None;
+ ///
- /// // Bad
+ /// 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);
- /// // Good
+ /// match x {
+ /// Foo::A(_) => {},
+ /// _ => {},
+ /// }
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # enum Foo { A(usize), B(usize) }
++ /// # let x = Foo::B(1);
+ /// 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;
- /// // Good
+ /// match x {
+ /// Foo::A => {},
+ /// Foo::B => {},
+ /// _ => {},
+ /// }
++ /// ```
+ ///
- /// // Bad
- /// match "foo" {
++ /// Use instead:
++ /// ```rust
++ /// # enum Foo { A, B, C }
++ /// # let x = Foo::B;
+ /// 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
- /// // Good
- /// match "foo" {
++ /// # let s = "foo";
++ /// match s {
+ /// "a" => {},
+ /// "bar" | _ => {},
+ /// }
++ /// ```
+ ///
- ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # let s = "foo";
++ /// match s {
+ /// "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;
- /// // Good
+ /// match (a, b) {
+ /// (c, d) => {
+ /// // useless match
+ /// }
+ /// }
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # let a = 1;
++ /// # let b = 2;
+ /// 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 };
+ ///
- /// // Good
+ /// match a {
+ /// A { a: 5, .. } => {},
+ /// _ => {},
+ /// }
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # struct A { a: i32 }
++ /// # let a = A { a: 5 };
+ /// 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);
+ ///
- /// // Good
+ /// let a = match x {
+ /// Some(0) => true,
+ /// _ => false,
+ /// };
+ ///
+ /// let a = if let Some(0) = x {
+ /// true
+ /// } else {
+ /// false
+ /// };
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// let x = Some(5);
+ /// 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;
+ ///
- /// // Good
+ /// match arr[idx] {
+ /// 0 => println!("{}", 0),
+ /// 1 => println!("{}", 3),
+ /// _ => {},
+ /// }
+ /// ```
++ ///
+ /// Use instead:
+ /// ```rust, no_run
+ /// let arr = vec![0, 1, 2, 3];
+ /// let idx = 1;
+ ///
+ /// 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 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 source == MatchSource::Normal && !span_starts_with(cx, expr.span, "match") {
+ return;
+ }
+ 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);
+ }
+ } 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
- use rustc_hir::{Expr, ExprKind, PatKind, QPath, UnOp};
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::{indent_of, reindent_multiline, snippet};
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::{is_trait_method, path_to_local_id, peel_blocks, SpanlessEq};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::def::Res;
- if SpanlessEq::new(cx).expr_fallback(eq_fallback).eq_expr(filter_arg, map_arg);
++use rustc_hir::{Expr, ExprKind, PatKind, PathSegment, QPath, UnOp};
+use rustc_lint::LateContext;
+use rustc_span::source_map::Span;
+use rustc_span::symbol::{sym, Symbol};
+use std::borrow::Cow;
+
+use super::MANUAL_FILTER_MAP;
+use super::MANUAL_FIND_MAP;
+use super::OPTION_FILTER_MAP;
+
+fn is_method<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, method_name: Symbol) -> bool {
+ match &expr.kind {
+ hir::ExprKind::Path(QPath::TypeRelative(_, mname)) => mname.ident.name == method_name,
+ hir::ExprKind::Path(QPath::Resolved(_, segments)) => {
+ segments.segments.last().unwrap().ident.name == method_name
+ },
+ hir::ExprKind::Closure { body, .. } => {
+ let body = cx.tcx.hir().body(*body);
+ let closure_expr = peel_blocks(&body.value);
+ let arg_id = body.params[0].pat.hir_id;
+ match closure_expr.kind {
+ hir::ExprKind::MethodCall(hir::PathSegment { ident, .. }, args, _) => {
+ if_chain! {
+ if ident.name == method_name;
+ if let hir::ExprKind::Path(path) = &args[0].kind;
+ if let Res::Local(ref local) = cx.qpath_res(path, args[0].hir_id);
+ then {
+ return arg_id == *local
+ }
+ }
+ false
+ },
+ _ => false,
+ }
+ },
+ _ => false,
+ }
+}
+
+fn is_option_filter_map<'tcx>(cx: &LateContext<'tcx>, filter_arg: &hir::Expr<'_>, map_arg: &hir::Expr<'_>) -> bool {
+ is_method(cx, map_arg, sym::unwrap) && is_method(cx, filter_arg, sym!(is_some))
+}
+
+/// lint use of `filter().map()` for `Iterators`
+fn lint_filter_some_map_unwrap(
+ cx: &LateContext<'_>,
+ expr: &hir::Expr<'_>,
+ filter_recv: &hir::Expr<'_>,
+ filter_arg: &hir::Expr<'_>,
+ map_arg: &hir::Expr<'_>,
+ target_span: Span,
+ methods_span: Span,
+) {
+ let iterator = is_trait_method(cx, expr, sym::Iterator);
+ let option = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(filter_recv), sym::Option);
+ if (iterator || option) && is_option_filter_map(cx, filter_arg, map_arg) {
+ let msg = "`filter` for `Some` followed by `unwrap`";
+ let help = "consider using `flatten` instead";
+ let sugg = format!(
+ "{}",
+ reindent_multiline(Cow::Borrowed("flatten()"), true, indent_of(cx, target_span),)
+ );
+ span_lint_and_sugg(
+ cx,
+ OPTION_FILTER_MAP,
+ methods_span,
+ msg,
+ help,
+ sugg,
+ Applicability::MachineApplicable,
+ );
+ }
+}
+
+/// lint use of `filter().map()` or `find().map()` for `Iterators`
+#[allow(clippy::too_many_arguments)]
+pub(super) fn check<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &hir::Expr<'_>,
+ filter_recv: &hir::Expr<'_>,
+ filter_arg: &hir::Expr<'_>,
+ filter_span: Span,
+ map_recv: &hir::Expr<'_>,
+ map_arg: &hir::Expr<'_>,
+ map_span: Span,
+ is_find: bool,
+) {
+ lint_filter_some_map_unwrap(
+ cx,
+ expr,
+ filter_recv,
+ filter_arg,
+ map_arg,
+ map_span,
+ filter_span.with_hi(expr.span.hi()),
+ );
+ if_chain! {
+ if is_trait_method(cx, map_recv, sym::Iterator);
+
+ // filter(|x| ...is_some())...
+ if let ExprKind::Closure { body: filter_body_id, .. } = filter_arg.kind;
+ let filter_body = cx.tcx.hir().body(filter_body_id);
+ if let [filter_param] = filter_body.params;
+ // optional ref pattern: `filter(|&x| ..)`
+ let (filter_pat, is_filter_param_ref) = if let PatKind::Ref(ref_pat, _) = filter_param.pat.kind {
+ (ref_pat, true)
+ } else {
+ (filter_param.pat, false)
+ };
+ // closure ends with is_some() or is_ok()
+ if let PatKind::Binding(_, filter_param_id, _, None) = filter_pat.kind;
+ if let ExprKind::MethodCall(path, [filter_arg], _) = filter_body.value.kind;
+ if let Some(opt_ty) = cx.typeck_results().expr_ty(filter_arg).ty_adt_def();
+ if let Some(is_result) = if cx.tcx.is_diagnostic_item(sym::Option, opt_ty.did()) {
+ Some(false)
+ } else if cx.tcx.is_diagnostic_item(sym::Result, opt_ty.did()) {
+ Some(true)
+ } else {
+ None
+ };
+ if path.ident.name.as_str() == if is_result { "is_ok" } else { "is_some" };
+
+ // ...map(|x| ...unwrap())
+ if let ExprKind::Closure { body: map_body_id, .. } = map_arg.kind;
+ let map_body = cx.tcx.hir().body(map_body_id);
+ if let [map_param] = map_body.params;
+ if let PatKind::Binding(_, map_param_id, map_param_ident, None) = map_param.pat.kind;
+ // closure ends with expect() or unwrap()
+ if let ExprKind::MethodCall(seg, [map_arg, ..], _) = map_body.value.kind;
+ if matches!(seg.ident.name, sym::expect | sym::unwrap | sym::unwrap_or);
+
+ let eq_fallback = |a: &Expr<'_>, b: &Expr<'_>| {
+ // in `filter(|x| ..)`, replace `*x` with `x`
+ let a_path = if_chain! {
+ if !is_filter_param_ref;
+ if let ExprKind::Unary(UnOp::Deref, expr_path) = a.kind;
+ then { expr_path } else { a }
+ };
+ // let the filter closure arg and the map closure arg be equal
+ if_chain! {
+ if path_to_local_id(a_path, filter_param_id);
+ if path_to_local_id(b, map_param_id);
+ if cx.typeck_results().expr_ty_adjusted(a) == cx.typeck_results().expr_ty_adjusted(b);
+ then {
+ return true;
+ }
+ }
+ false
+ };
++
++ if match map_arg.kind {
++ ExprKind::MethodCall(method, [original_arg], _) => {
++ acceptable_methods(method)
++ && SpanlessEq::new(cx).expr_fallback(eq_fallback).eq_expr(filter_arg, original_arg)
++ },
++ _ => SpanlessEq::new(cx).expr_fallback(eq_fallback).eq_expr(filter_arg, map_arg)
++ };
++
+ then {
+ let span = filter_span.with_hi(expr.span.hi());
+ let (filter_name, lint) = if is_find {
+ ("find", MANUAL_FIND_MAP)
+ } else {
+ ("filter", MANUAL_FILTER_MAP)
+ };
+ let msg = format!("`{}(..).map(..)` can be simplified as `{0}_map(..)`", filter_name);
+ let to_opt = if is_result { ".ok()" } else { "" };
+ let sugg = format!("{}_map(|{}| {}{})", filter_name, map_param_ident,
+ snippet(cx, map_arg.span, ".."), to_opt);
+ span_lint_and_sugg(cx, lint, span, &msg, "try", sugg, Applicability::MachineApplicable);
+ }
+ }
+}
++
++fn acceptable_methods(method: &PathSegment<'_>) -> bool {
++ let methods: [Symbol; 8] = [
++ sym::clone,
++ sym::as_ref,
++ sym!(copied),
++ sym!(cloned),
++ sym!(as_deref),
++ sym!(as_mut),
++ sym!(as_deref_mut),
++ sym!(to_owned),
++ ];
++
++ methods.contains(&method.ident.name)
++}
--- /dev/null
- use clippy_utils::diagnostics::span_lint_and_sugg;
- use clippy_utils::source::snippet;
- use clippy_utils::ty::{get_iterator_item_ty, implements_trait, is_copy};
- use itertools::Itertools;
++use clippy_utils::diagnostics::span_lint_and_then;
++use clippy_utils::source::snippet_opt;
++use clippy_utils::ty::{get_associated_type, implements_trait, is_copy};
+use rustc_errors::Applicability;
- use rustc_hir as hir;
++use rustc_hir::Expr;
+use rustc_lint::LateContext;
+use rustc_middle::ty;
+use rustc_span::sym;
- use std::ops::Not;
+
+use super::ITER_OVEREAGER_CLONED;
+use crate::redundant_clone::REDUNDANT_CLONE;
+
- /// lint overeager use of `cloned()` for `Iterator`s
+pub(super) fn check<'tcx>(
+ cx: &LateContext<'tcx>,
- expr: &'tcx hir::Expr<'_>,
- recv: &'tcx hir::Expr<'_>,
- name: &str,
- map_arg: &[hir::Expr<'_>],
++ expr: &'tcx Expr<'_>,
++ cloned_call: &'tcx Expr<'_>,
++ cloned_recv: &'tcx Expr<'_>,
++ is_count: bool,
++ needs_into_iter: bool,
+) {
- // Check if it's iterator and get type associated with `Item`.
- let inner_ty = if_chain! {
- if let Some(iterator_trait_id) = cx.tcx.get_diagnostic_item(sym::Iterator);
- let recv_ty = cx.typeck_results().expr_ty(recv);
- if implements_trait(cx, recv_ty, iterator_trait_id, &[]);
- if let Some(inner_ty) = get_iterator_item_ty(cx, cx.typeck_results().expr_ty_adjusted(recv));
- then {
- inner_ty
- } else {
++ let typeck = cx.typeck_results();
++ if let Some(iter_id) = cx.tcx.get_diagnostic_item(sym::Iterator)
++ && let Some(method_id) = typeck.type_dependent_def_id(expr.hir_id)
++ && cx.tcx.trait_of_item(method_id) == Some(iter_id)
++ && let Some(method_id) = typeck.type_dependent_def_id(cloned_call.hir_id)
++ && cx.tcx.trait_of_item(method_id) == Some(iter_id)
++ && let cloned_recv_ty = typeck.expr_ty_adjusted(cloned_recv)
++ && let Some(iter_assoc_ty) = get_associated_type(cx, cloned_recv_ty, iter_id, "Item")
++ && matches!(*iter_assoc_ty.kind(), ty::Ref(_, ty, _) if !is_copy(cx, ty))
++ {
++ if needs_into_iter
++ && let Some(into_iter_id) = cx.tcx.get_diagnostic_item(sym::IntoIterator)
++ && !implements_trait(cx, iter_assoc_ty, into_iter_id, &[])
++ {
+ return;
+ }
- };
-
- match inner_ty.kind() {
- ty::Ref(_, ty, _) if !is_copy(cx, *ty) => {},
- _ => return,
- };
+
- let (lint, preserve_cloned) = match name {
- "count" => (REDUNDANT_CLONE, false),
- _ => (ITER_OVEREAGER_CLONED, true),
- };
- let wildcard_params = map_arg.is_empty().not().then(|| "...").unwrap_or_default();
- let msg = format!(
- "called `cloned().{}({})` on an `Iterator`. It may be more efficient to call `{}({}){}` instead",
- name,
- wildcard_params,
- name,
- wildcard_params,
- preserve_cloned.then(|| ".cloned()").unwrap_or_default(),
- );
++ let (lint, msg, trailing_clone) = if is_count {
++ (REDUNDANT_CLONE, "unneeded cloning of iterator items", "")
++ } else {
++ (ITER_OVEREAGER_CLONED, "unnecessarily eager cloning of iterator items", ".cloned()")
++ };
+
- span_lint_and_sugg(
- cx,
- lint,
- expr.span,
- &msg,
- "try this",
- format!(
- "{}.{}({}){}",
- snippet(cx, recv.span, ".."),
- name,
- map_arg.iter().map(|a| snippet(cx, a.span, "..")).join(", "),
- preserve_cloned.then(|| ".cloned()").unwrap_or_default(),
- ),
- Applicability::MachineApplicable,
- );
++ span_lint_and_then(
++ cx,
++ lint,
++ expr.span,
++ msg,
++ |diag| {
++ let method_span = expr.span.with_lo(cloned_call.span.hi());
++ if let Some(mut snip) = snippet_opt(cx, method_span) {
++ snip.push_str(trailing_clone);
++ let replace_span = expr.span.with_lo(cloned_recv.span.hi());
++ diag.span_suggestion(replace_span, "try this", snip, Applicability::MachineApplicable);
++ }
++ }
++ );
++ }
+}
--- /dev/null
- ///
- /// // Bad
+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.
+ ///
++ /// ### 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.
++ ///
+ /// ### Examples
+ /// ```rust
+ /// # let vec = vec!["string".to_string()];
- ///
- /// // Good
- /// vec.iter().take(10).cloned();
- ///
- /// // Bad
+ /// vec.iter().cloned().take(10);
- /// // Good
+ /// vec.iter().cloned().last();
++ /// ```
+ ///
- ///
++ /// Use instead:
++ /// ```rust
++ /// # let vec = vec!["string".to_string()];
++ /// vec.iter().take(10).cloned();
+ /// 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"]
+ /// ```
- ///
- /// // Bad
++ #[clippy::version = "1.60.0"]
+ 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
+ /// # let option = Some(1);
+ /// # let result: Result<usize, ()> = Ok(1);
+ /// option.unwrap();
+ /// result.unwrap();
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// # 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
+ /// # let option = Some(1);
+ /// # let result: Result<usize, ()> = Ok(1);
+ /// option.expect("one");
+ /// result.expect("one");
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust,ignore
+ /// # let option = Some(1);
+ /// # let result: Result<usize, ()> = Ok(1);
+ /// option?;
+ ///
+ /// // or
+ ///
+ /// 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::<_, ()>(());
- /// // Good
+ /// x.ok().expect("why did I do this again?");
++ /// ```
+ ///
- ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # let x = Ok::<_, ()>(());
+ /// 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);
- /// // Good
+ /// x.unwrap_or_else(Default::default);
+ /// x.unwrap_or_else(u32::default);
++ /// ```
+ ///
- ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # let x = Some(1);
+ /// 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
+ /// # 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);
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// # let option = Some(1);
+ /// # let result: Result<usize, ()> = Ok(1);
+ /// # fn some_function(foo: ()) -> usize { 1 }
+ /// 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);
- /// // Good
+ /// opt.map_or(None, |a| Some(a + 1));
++ /// ```
+ ///
- /// Bad:
++ /// Use instead:
++ /// ```rust
++ /// # let opt = Some(1);
+ /// 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
- /// Good:
+ /// ```rust
+ /// # let r: Result<u32, &str> = Ok(1);
+ /// assert_eq!(Some(1), r.map_or(None, Some));
+ /// ```
+ ///
- /// Could be written as
++ /// Use instead:
+ /// ```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
++ ///
++ /// Use instead:
+ /// ```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();
+ /// ```
- /// // Bad
++ ///
++ /// Use instead:
+ /// ```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);
+ ///
- /// // Good
+ /// vec.iter().map(|x| x.iter()).flatten();
+ /// opt.map(|x| Some(x * 2)).flatten();
++ /// ```
+ ///
- /// Bad:
++ /// Use instead:
++ /// ```rust
++ /// # let vec = vec![vec![1]];
++ /// # let opt = Some(5);
+ /// 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
- /// Good:
+ /// ```rust
++ /// # #![allow(unused)]
+ /// (0_i32..10)
+ /// .filter(|n| n.checked_add(1).is_some())
+ /// .map(|n| n.checked_add(1).unwrap());
+ /// ```
+ ///
- /// Bad:
++ /// Use instead:
+ /// ```rust
++ /// # #[allow(unused)]
+ /// (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
- /// Good:
+ /// ```rust
+ /// (0_i32..10)
+ /// .find(|n| n.checked_add(1).is_some())
+ /// .map(|n| n.checked_add(1).unwrap());
+ /// ```
+ ///
- /// let _ = "hello world".find("world").is_none();
++ /// Use instead:
+ /// ```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
++ /// # #![allow(unused)]
+ /// let vec = vec![1];
+ /// vec.iter().find(|x| **x == 0).is_some();
+ ///
- /// Could be written as
++ /// "hello world".find("world").is_none();
+ /// ```
- /// let _ = !"hello world".contains("world");
++ ///
++ /// Use instead:
+ /// ```rust
+ /// let vec = vec![1];
+ /// vec.iter().any(|x| *x == 0);
+ ///
- /// Could be written as
++ /// # #[allow(unused)]
++ /// !"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('_') {};
+ /// ```
- /// // Bad
++ ///
++ /// Use instead:
+ /// ```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());
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// # let foo = Some(String::new());
+ /// foo.unwrap_or_else(String::new);
+ ///
+ /// // 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));
+ ///
+ /// // or
+ ///
+ /// # let foo = Some(String::new());
+ /// 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);
+ ///
- /// // Good
+ /// x.clone();
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # use std::rc::Rc;
++ /// # let x = Rc::new(1);
+ /// 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
- /// // Good
+ /// _.split("x");
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust,ignore
+ /// _.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;
- /// // Good
+ /// # let mut s = HashSet::new();
+ /// # s.insert(1);
+ /// let x = s.iter().nth(0);
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # use std::collections::HashSet;
+ /// # 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
- /// // Good
+ /// let x = vec![2, 3, 5];
+ /// let last_element = x.get(x.len() - 1);
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
+ /// 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];
+ ///
- /// // Good
+ /// a.extend(b.drain(..));
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// let mut a = vec![1, 2, 3];
++ /// let mut b = vec![4, 5, 6];
+ ///
- ///
- /// // Bad
+ /// 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 = "_";
- /// // Good
+ /// name.chars().last() == Some('_') || name.chars().next_back() == Some('-');
++ /// ```
+ ///
- /// let _ = (0..3).fold(false, |acc, x| acc || x > 2);
++ /// Use instead:
++ /// ```rust
++ /// # let name = "_";
+ /// 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
- /// This could be written as:
++ /// # #[allow(unused)]
++ /// (0..3).fold(false, |acc, x| acc || x > 2);
+ /// ```
- /// let _ = (0..3).any(|x| x > 2);
++ ///
++ /// Use instead:
+ /// ```rust
- /// // Bad
- /// let _ = (&vec![3, 4, 5]).into_iter();
++ /// (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
- /// // Good
- /// let _ = (&vec![3, 4, 5]).iter();
++ /// # let vec = vec![3, 4, 5];
++ /// (&vec).into_iter();
++ /// ```
+ ///
- /// let mut string = String::new();
++ /// Use instead:
++ /// ```rust
++ /// # let vec = vec![3, 4, 5];
++ /// (&vec).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
- /// Could be written as
++ /// # let mut string = String::new();
+ /// string.insert_str(0, "R");
+ /// string.push_str("R");
+ /// ```
- /// let mut string = String::new();
++ ///
++ /// Use instead:
+ /// ```rust
- #[clippy::version = "1.52.0"]
++ /// # 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();
+ /// ```
- /// // Bad
- /// let _ = "Hello".bytes().nth(3);
++ #[clippy::version = "1.47.0"]
+ 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
- /// // Good
- /// let _ = "Hello".as_bytes().get(3);
++ /// # #[allow(unused)]
++ /// "Hello".bytes().nth(3);
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # #[allow(unused)]
++ /// "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
- /// let _ = some_vec.iter().count();
- /// let _ = &some_vec[..].iter().count();
++ /// # #![allow(unused)]
+ /// let some_vec = vec![0, 1, 2, 3];
- /// // Good
+ ///
- /// let _ = some_vec.len();
- /// let _ = &some_vec[..].len();
++ /// some_vec.iter().count();
++ /// &some_vec[..].iter().count();
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
+ /// let some_vec = vec![0, 1, 2, 3];
- /// // Bad
- /// let s = "";
++ ///
++ /// some_vec.len();
++ /// &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
- /// // use x
++ /// # let s = "";
+ /// for x in s.splitn(1, ":") {
- /// // Good
- /// let s = "";
++ /// // ..
+ /// }
++ /// ```
+ ///
- /// // use x
++ /// Use instead:
++ /// ```rust
++ /// # let s = "";
+ /// for x in s.splitn(2, ":") {
- /// // Bad
++ /// // ..
+ /// }
+ /// ```
+ #[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
- /// // Good
+ /// let x: String = std::iter::repeat('x').take(10).collect();
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
+ /// 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
- /// // Good
+ /// 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
- /// // Bad
+ /// 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
- /// // Good
+ /// let str = "key=value=add";
+ /// let _ = str.splitn(3, '=').next().unwrap();
+ /// ```
++ ///
+ /// Use instead:
+ /// ```rust
- #[clippy::version = "1.58.0"]
+ /// let str = "key=value=add";
+ /// let _ = str.split('=').next().unwrap();
+ /// ```
- #[clippy::version = "1.58.0"]
++ #[clippy::version = "1.59.0"]
+ 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) {}
+ /// ```
- /// Could be written as:
++ #[clippy::version = "1.59.0"]
+ 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>
+ /// ```
- (name @ "count", args @ []) => match method_call(recv) {
- Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
++ ///
++ /// Use instead:
+ /// ```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 @ "flatten", args @ []) => match method_call(recv) {
++ ("count", []) => match method_call(recv) {
++ Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv, recv2, true, false),
+ 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);
+ },
- Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
++ ("flatten", []) => match method_call(recv) {
+ Some(("map", [recv, map_arg], map_span)) => map_flatten::check(cx, expr, recv, map_arg, map_span),
- ("last", args @ []) | ("skip", args @ [_]) => {
++ Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv, recv2, false, true),
+ _ => {},
+ },
+ ("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);
+ }
+ },
- iter_overeager_cloned::check(cx, expr, recv2, name, args);
++ ("last", []) | ("skip", [_]) => {
+ if let Some((name2, [recv2, args2 @ ..], _span2)) = method_call(recv) {
+ if let ("cloned", []) = (name2, args2) {
- (name @ "next", args @ []) => {
++ iter_overeager_cloned::check(cx, expr, recv, recv2, false, false);
+ }
+ }
+ },
+ (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),
- ("cloned", []) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
++ ("next", []) => {
+ if let Some((name2, [recv2, args2 @ ..], _)) = method_call(recv) {
+ match (name2, args2) {
- ("nth", args @ [n_arg]) => match method_call(recv) {
++ ("cloned", []) => iter_overeager_cloned::check(cx, expr, recv, recv2, false, false),
+ ("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),
+ _ => {},
+ }
+ }
+ },
- Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
++ ("nth", [n_arg]) => match method_call(recv) {
+ Some(("bytes", [recv2], _)) => bytes_nth::check(cx, expr, recv2, n_arg),
- ("take", args @ [_arg]) => {
++ Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv, recv2, false, false),
+ 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),
- iter_overeager_cloned::check(cx, expr, recv2, name, args);
++ ("take", [_arg]) => {
+ if let Some((name2, [recv2, args2 @ ..], _span2)) = method_call(recv) {
+ if let ("cloned", []) = (name2, args2) {
++ iter_overeager_cloned::check(cx, expr, recv, recv2, false, false);
+ }
+ }
+ },
+ ("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
- /// ```rust,ignore
- /// // Bad
- /// fn foo(ref x: u8) -> bool {
- /// true
- /// }
+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
- /// // Good
- /// fn foo(x: &u8) -> bool {
- /// true
- /// }
++ /// ```rust
++ /// fn foo(ref _x: u8) {}
++ /// ```
+ ///
- ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// fn foo(_x: &u8) {}
+ /// ```
+ #[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;
- /// // Good
+ /// if x == f32::NAN { }
++ /// ```
+ ///
- /// Could be written as
++ /// Use instead:
++ /// ```rust
++ /// # let x = 1.0f32;
+ /// 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;
+ ///
+ /// if y == 1.23f64 { }
+ /// if y != x {} // where both are floats
+ /// ```
+ ///
+ /// 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 {}
+ /// ```
- /// // Bad
++ ///
++ /// Use instead:
+ /// ```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
- /// // Good
+ /// let a = 0 as *const u32;
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
+ /// 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;
+ ///
+ /// 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
- /// // Bad
+mod builtin_type_shadow;
+mod double_neg;
+mod literal_suffix;
+mod mixed_case_hex_literals;
+mod redundant_pattern;
+mod unneeded_field_pattern;
+mod unneeded_wildcard_pattern;
+mod zero_prefixed_literal;
+
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::source::snippet_opt;
+use rustc_ast::ast::{Expr, ExprKind, Generics, Lit, LitFloatType, LitIntType, LitKind, NodeId, Pat, PatKind};
+use rustc_ast::visit::FnKind;
+use rustc_data_structures::fx::FxHashMap;
+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 structure field patterns bound to wildcards.
+ ///
+ /// ### Why is this bad?
+ /// Using `..` instead is shorter and leaves the focus on
+ /// the fields that are actually bound.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # struct Foo {
+ /// # a: i32,
+ /// # b: i32,
+ /// # c: i32,
+ /// # }
+ /// let f = Foo { a: 0, b: 0, c: 0 };
+ ///
- /// // Good
+ /// match f {
+ /// Foo { a: _, b: 0, .. } => {},
+ /// Foo { a: _, b: _, c: _ } => {},
+ /// }
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// # struct Foo {
++ /// # a: i32,
++ /// # b: i32,
++ /// # c: i32,
++ /// # }
++ /// let f = Foo { a: 0, b: 0, c: 0 };
+ ///
- /// // Bad
+ /// match f {
+ /// Foo { b: 0, .. } => {},
+ /// Foo { .. } => {},
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub UNNEEDED_FIELD_PATTERN,
+ restriction,
+ "struct fields bound to a wildcard instead of using `..`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for function arguments having the similar names
+ /// differing by an underscore.
+ ///
+ /// ### Why is this bad?
+ /// It affects code readability.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// fn foo(a: i32, _a: i32) {}
++ /// ```
+ ///
- /// // Bad
- /// let y = 0x1a9BAcD;
++ /// Use instead:
++ /// ```rust
+ /// fn bar(a: i32, _b: i32) {}
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DUPLICATE_UNDERSCORE_ARGUMENT,
+ style,
+ "function arguments having names which only differ by an underscore"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Detects expressions of the form `--x`.
+ ///
+ /// ### Why is this bad?
+ /// It can mislead C/C++ programmers to think `x` was
+ /// decremented.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let mut x = 3;
+ /// --x;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DOUBLE_NEG,
+ style,
+ "`--x`, which is a double negation of `x` and not a pre-decrement as in C/C++"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns on hexadecimal literals with mixed-case letter
+ /// digits.
+ ///
+ /// ### Why is this bad?
+ /// It looks confusing.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
- /// let y = 0x1A9BACD;
++ /// # let _ =
++ /// 0x1a9BAcD
++ /// # ;
++ /// ```
+ ///
- /// // Bad
- /// let y = 123832i32;
++ /// Use instead:
++ /// ```rust
++ /// # let _ =
++ /// 0x1A9BACD
++ /// # ;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MIXED_CASE_HEX_LITERALS,
+ style,
+ "hex literals whose letter digits are not consistently upper- or lowercased"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns if literal suffixes are not separated by an
+ /// underscore.
+ /// To enforce unseparated literal suffix style,
+ /// see the `separated_literal_suffix` lint.
+ ///
+ /// ### Why is this bad?
+ /// Suffix style should be consistent.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
- /// let y = 123832_i32;
++ /// # let _ =
++ /// 123832i32
++ /// # ;
++ /// ```
+ ///
- /// // Bad
- /// let y = 123832_i32;
++ /// Use instead:
++ /// ```rust
++ /// # let _ =
++ /// 123832_i32
++ /// # ;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub UNSEPARATED_LITERAL_SUFFIX,
+ restriction,
+ "literals whose suffix is not separated by an underscore"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns if literal suffixes are separated by an underscore.
+ /// To enforce separated literal suffix style,
+ /// see the `unseparated_literal_suffix` lint.
+ ///
+ /// ### Why is this bad?
+ /// Suffix style should be consistent.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
- /// let y = 123832i32;
++ /// # let _ =
++ /// 123832_i32
++ /// # ;
++ /// ```
+ ///
- ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # let _ =
++ /// 123832i32
++ /// # ;
+ /// ```
+ #[clippy::version = "1.58.0"]
+ pub SEPARATED_LITERAL_SUFFIX,
+ restriction,
+ "literals whose suffix is separated by an underscore"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns if an integral constant literal starts with `0`.
+ ///
+ /// ### Why is this bad?
+ /// In some languages (including the infamous C language
+ /// and most of its
+ /// family), this marks an octal constant. In Rust however, this is a decimal
+ /// constant. This could
+ /// be confusing for both the writer and a reader of the constant.
+ ///
+ /// ### Example
+ ///
+ /// In Rust:
+ /// ```rust
+ /// fn main() {
+ /// let a = 0123;
+ /// println!("{}", a);
+ /// }
+ /// ```
+ ///
+ /// prints `123`, while in C:
+ ///
+ /// ```c
+ /// #include <stdio.h>
+ ///
+ /// int main() {
+ /// int a = 0123;
+ /// printf("%d\n", a);
+ /// }
+ /// ```
+ ///
+ /// prints `83` (as `83 == 0o123` while `123 == 0o173`).
+ #[clippy::version = "pre 1.29.0"]
+ pub ZERO_PREFIXED_LITERAL,
+ complexity,
+ "integer literals starting with `0`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns if a generic shadows a built-in type.
+ ///
+ /// ### Why is this bad?
+ /// This gives surprising type errors.
+ ///
+ /// ### Example
+ ///
+ /// ```ignore
+ /// impl<u32> Foo<u32> {
+ /// fn impl_func(&self) -> u32 {
+ /// 42
+ /// }
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub BUILTIN_TYPE_SHADOW,
+ style,
+ "shadowing a builtin type"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for patterns in the form `name @ _`.
+ ///
+ /// ### Why is this bad?
+ /// It's almost always more readable to just use direct
+ /// bindings.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let v = Some("abc");
- /// // Good
+ /// match v {
+ /// Some(x) => (),
+ /// y @ _ => (),
+ /// }
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # let v = Some("abc");
+ /// match v {
+ /// Some(x) => (),
+ /// y => (),
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub REDUNDANT_PATTERN,
+ style,
+ "using `name @ _` in a pattern"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for tuple patterns with a wildcard
+ /// pattern (`_`) is next to a rest pattern (`..`).
+ ///
+ /// _NOTE_: While `_, ..` means there is at least one element left, `..`
+ /// means there are 0 or more elements left. This can make a difference
+ /// when refactoring, but shouldn't result in errors in the refactored code,
+ /// since the wildcard pattern isn't used anyway.
++ ///
+ /// ### Why is this bad?
+ /// The wildcard pattern is unneeded as the rest pattern
+ /// can match that element as well.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # struct TupleStruct(u32, u32, u32);
+ /// # let t = TupleStruct(1, 2, 3);
- /// // Good
+ /// match t {
+ /// TupleStruct(0, .., _) => (),
+ /// _ => (),
+ /// }
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # struct TupleStruct(u32, u32, u32);
++ /// # let t = TupleStruct(1, 2, 3);
+ /// match t {
+ /// TupleStruct(0, ..) => (),
+ /// _ => (),
+ /// }
+ /// ```
+ #[clippy::version = "1.40.0"]
+ pub UNNEEDED_WILDCARD_PATTERN,
+ complexity,
+ "tuple patterns with a wildcard pattern (`_`) is next to a rest pattern (`..`)"
+}
+
+declare_lint_pass!(MiscEarlyLints => [
+ UNNEEDED_FIELD_PATTERN,
+ DUPLICATE_UNDERSCORE_ARGUMENT,
+ DOUBLE_NEG,
+ MIXED_CASE_HEX_LITERALS,
+ UNSEPARATED_LITERAL_SUFFIX,
+ SEPARATED_LITERAL_SUFFIX,
+ ZERO_PREFIXED_LITERAL,
+ BUILTIN_TYPE_SHADOW,
+ REDUNDANT_PATTERN,
+ UNNEEDED_WILDCARD_PATTERN,
+]);
+
+impl EarlyLintPass for MiscEarlyLints {
+ fn check_generics(&mut self, cx: &EarlyContext<'_>, gen: &Generics) {
+ for param in &gen.params {
+ builtin_type_shadow::check(cx, param);
+ }
+ }
+
+ fn check_pat(&mut self, cx: &EarlyContext<'_>, pat: &Pat) {
+ unneeded_field_pattern::check(cx, pat);
+ redundant_pattern::check(cx, pat);
+ unneeded_wildcard_pattern::check(cx, pat);
+ }
+
+ fn check_fn(&mut self, cx: &EarlyContext<'_>, fn_kind: FnKind<'_>, _: Span, _: NodeId) {
+ let mut registered_names: FxHashMap<String, Span> = FxHashMap::default();
+
+ for arg in &fn_kind.decl().inputs {
+ if let PatKind::Ident(_, ident, None) = arg.pat.kind {
+ let arg_name = ident.to_string();
+
+ if let Some(arg_name) = arg_name.strip_prefix('_') {
+ if let Some(correspondence) = registered_names.get(arg_name) {
+ span_lint(
+ cx,
+ DUPLICATE_UNDERSCORE_ARGUMENT,
+ *correspondence,
+ &format!(
+ "`{}` already exists, having another argument having almost the same \
+ name makes code comprehension and documentation more difficult",
+ arg_name
+ ),
+ );
+ }
+ } else {
+ registered_names.insert(arg_name, arg.pat.span);
+ }
+ }
+ }
+ }
+
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+
+ if let ExprKind::Lit(ref lit) = expr.kind {
+ MiscEarlyLints::check_lit(cx, lit);
+ }
+ double_neg::check(cx, expr);
+ }
+}
+
+impl MiscEarlyLints {
+ fn check_lit(cx: &EarlyContext<'_>, lit: &Lit) {
+ // We test if first character in snippet is a number, because the snippet could be an expansion
+ // from a built-in macro like `line!()` or a proc-macro like `#[wasm_bindgen]`.
+ // Note that this check also covers special case that `line!()` is eagerly expanded by compiler.
+ // See <https://github.com/rust-lang/rust-clippy/issues/4507> for a regression.
+ // FIXME: Find a better way to detect those cases.
+ let lit_snip = match snippet_opt(cx, lit.span) {
+ Some(snip) if snip.chars().next().map_or(false, |c| c.is_ascii_digit()) => snip,
+ _ => return,
+ };
+
+ if let LitKind::Int(value, lit_int_type) = lit.kind {
+ let suffix = match lit_int_type {
+ LitIntType::Signed(ty) => ty.name_str(),
+ LitIntType::Unsigned(ty) => ty.name_str(),
+ LitIntType::Unsuffixed => "",
+ };
+ literal_suffix::check(cx, lit, &lit_snip, suffix, "integer");
+ if lit_snip.starts_with("0x") {
+ mixed_case_hex_literals::check(cx, lit, suffix, &lit_snip);
+ } else if lit_snip.starts_with("0b") || lit_snip.starts_with("0o") {
+ // nothing to do
+ } else if value != 0 && lit_snip.starts_with('0') {
+ zero_prefixed_literal::check(cx, lit, &lit_snip);
+ }
+ } else if let LitKind::Float(_, LitFloatType::Suffixed(float_ty)) = lit.kind {
+ let suffix = float_ty.name_str();
+ literal_suffix::check(cx, lit, &lit_snip, suffix, "float");
+ }
+ }
+}
--- /dev/null
- /// // Bad
+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;
+ ///
- /// // Good
+ /// let a = {
+ /// x = 1;
+ /// 1
+ /// } + x;
+ /// // Unclear whether a is 1 or 2.
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # let mut x = 0;
+ /// 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
- /// ```ignore
- /// // Bad
- /// my_vec.push(&mut value)
+use clippy_utils::diagnostics::span_lint;
+use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::subst::Subst;
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use std::iter;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Detects passing a mutable reference to a function that only
+ /// requires an immutable reference.
+ ///
+ /// ### Why is this bad?
+ /// The mutable reference rules out all other references to
+ /// the value. Also the code misleads about the intent of the call site.
+ ///
+ /// ### Example
- /// // Good
- /// my_vec.push(&value)
++ /// ```rust
++ /// # let mut vec = Vec::new();
++ /// # let mut value = 5;
++ /// vec.push(&mut value);
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # let mut vec = Vec::new();
++ /// # let value = 5;
++ /// vec.push(&value);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub UNNECESSARY_MUT_PASSED,
+ style,
+ "an argument passed as a mutable reference although the callee only demands an immutable reference"
+}
+
+declare_lint_pass!(UnnecessaryMutPassed => [UNNECESSARY_MUT_PASSED]);
+
+impl<'tcx> LateLintPass<'tcx> for UnnecessaryMutPassed {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ match e.kind {
+ ExprKind::Call(fn_expr, arguments) => {
+ if let ExprKind::Path(ref path) = fn_expr.kind {
+ check_arguments(
+ cx,
+ arguments,
+ cx.typeck_results().expr_ty(fn_expr),
+ &rustc_hir_pretty::to_string(rustc_hir_pretty::NO_ANN, |s| s.print_qpath(path, false)),
+ "function",
+ );
+ }
+ },
+ ExprKind::MethodCall(path, arguments, _) => {
+ let def_id = cx.typeck_results().type_dependent_def_id(e.hir_id).unwrap();
+ let substs = cx.typeck_results().node_substs(e.hir_id);
+ let method_type = cx.tcx.bound_type_of(def_id).subst(cx.tcx, substs);
+ check_arguments(cx, arguments, method_type, path.ident.as_str(), "method");
+ },
+ _ => (),
+ }
+ }
+}
+
+fn check_arguments<'tcx>(
+ cx: &LateContext<'tcx>,
+ arguments: &[Expr<'_>],
+ type_definition: Ty<'tcx>,
+ name: &str,
+ fn_kind: &str,
+) {
+ match type_definition.kind() {
+ ty::FnDef(..) | ty::FnPtr(_) => {
+ let parameters = type_definition.fn_sig(cx.tcx).skip_binder().inputs();
+ for (argument, parameter) in iter::zip(arguments, parameters) {
+ match parameter.kind() {
+ ty::Ref(_, _, Mutability::Not)
+ | ty::RawPtr(ty::TypeAndMut {
+ mutbl: Mutability::Not, ..
+ }) => {
+ if let ExprKind::AddrOf(BorrowKind::Ref, Mutability::Mut, _) = argument.kind {
+ span_lint(
+ cx,
+ UNNECESSARY_MUT_PASSED,
+ argument.span,
+ &format!("the {} `{}` doesn't need a mutable reference", fn_kind, name),
+ );
+ }
+ },
+ _ => (),
+ }
+ }
+ },
+ _ => (),
+ }
+}
--- /dev/null
- ///
- /// // Bad
+//! Checks for uses of mutex where an atomic value could be used
+//!
+//! This lint is **warn** by default
+
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::ty::is_type_diagnostic_item;
+use rustc_hir::Expr;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usages of `Mutex<X>` where an atomic will do.
+ ///
+ /// ### Why is this bad?
+ /// Using a mutex just to make access to a plain bool or
+ /// reference sequential is shooting flies with cannons.
+ /// `std::sync::atomic::AtomicBool` and `std::sync::atomic::AtomicPtr` are leaner and
+ /// faster.
+ ///
+ /// ### Known problems
+ /// This lint cannot detect if the mutex is actually used
+ /// for waiting before a critical section.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let y = true;
- /// // Good
+ /// # use std::sync::Mutex;
+ /// let x = Mutex::new(&y);
++ /// ```
+ ///
- /// // Good
++ /// Use instead:
++ /// ```rust
++ /// # let y = true;
+ /// # use std::sync::atomic::AtomicBool;
+ /// let x = AtomicBool::new(y);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MUTEX_ATOMIC,
+ nursery,
+ "using a mutex where an atomic value could be used instead"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usages of `Mutex<X>` where `X` is an integral
+ /// type.
+ ///
+ /// ### Why is this bad?
+ /// Using a mutex just to make access to a plain integer
+ /// sequential is
+ /// shooting flies with cannons. `std::sync::atomic::AtomicUsize` is leaner and faster.
+ ///
+ /// ### Known problems
+ /// This lint cannot detect if the mutex is actually used
+ /// for waiting before a critical section.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::sync::Mutex;
+ /// let x = Mutex::new(0usize);
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
+ /// # use std::sync::atomic::AtomicUsize;
+ /// let x = AtomicUsize::new(0usize);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MUTEX_INTEGER,
+ nursery,
+ "using a mutex for an integer type"
+}
+
+declare_lint_pass!(Mutex => [MUTEX_ATOMIC, MUTEX_INTEGER]);
+
+impl<'tcx> LateLintPass<'tcx> for Mutex {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ let ty = cx.typeck_results().expr_ty(expr);
+ if let ty::Adt(_, subst) = ty.kind() {
+ if is_type_diagnostic_item(cx, ty, sym::Mutex) {
+ let mutex_param = subst.type_at(0);
+ if let Some(atomic_name) = get_atomic_name(mutex_param) {
+ let msg = format!(
+ "consider using an `{}` instead of a `Mutex` here; if you just want the locking \
+ behavior and not the internal type, consider using `Mutex<()>`",
+ atomic_name
+ );
+ match *mutex_param.kind() {
+ ty::Uint(t) if t != ty::UintTy::Usize => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
+ ty::Int(t) if t != ty::IntTy::Isize => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
+ _ => span_lint(cx, MUTEX_ATOMIC, expr.span, &msg),
+ };
+ }
+ }
+ }
+ }
+}
+
+fn get_atomic_name(ty: Ty<'_>) -> Option<&'static str> {
+ match ty.kind() {
+ ty::Bool => Some("AtomicBool"),
+ ty::Uint(_) => Some("AtomicUsize"),
+ ty::Int(_) => Some("AtomicIsize"),
+ ty::RawPtr(_) => Some("AtomicPtr"),
+ _ => None,
+ }
+}
--- /dev/null
- /// ```rust,ignore
+//! Checks for needless boolean results of if-else expressions
+//!
+//! This lint is **warn** by default
+
+use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg};
+use clippy_utils::higher;
+use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::sugg::Sugg;
+use clippy_utils::{get_parent_node, is_else_clause, is_expn_of, peel_blocks, peel_blocks_with_stmt};
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Block, Expr, ExprKind, HirId, Node, UnOp};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Spanned;
+use rustc_span::Span;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for expressions of the form `if c { true } else {
+ /// false }` (or vice versa) and suggests using the condition directly.
+ ///
+ /// ### Why is this bad?
+ /// Redundant code.
+ ///
+ /// ### Known problems
+ /// Maybe false positives: Sometimes, the two branches are
+ /// painstakingly documented (which we, of course, do not detect), so they *may*
+ /// have some value. Even then, the documentation can be rewritten to match the
+ /// shorter code.
+ ///
+ /// ### Example
- /// Could be written as
- /// ```rust,ignore
++ /// ```rust
++ /// # let x = true;
+ /// if x {
+ /// false
+ /// } else {
+ /// true
+ /// }
++ /// # ;
+ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// # let x = true;
+ /// !x
++ /// # ;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NEEDLESS_BOOL,
+ complexity,
+ "if-statements with plain booleans in the then- and else-clause, e.g., `if p { true } else { false }`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for expressions of the form `x == true`,
+ /// `x != true` and order comparisons such as `x < true` (or vice versa) and
+ /// suggest using the variable directly.
+ ///
+ /// ### Why is this bad?
+ /// Unnecessary code.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// if x == true {}
+ /// if y == false {}
+ /// ```
+ /// use `x` directly:
+ /// ```rust,ignore
+ /// if x {}
+ /// if !y {}
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub BOOL_COMPARISON,
+ complexity,
+ "comparing a variable to a boolean, e.g., `if x == true` or `if x != true`"
+}
+
+declare_lint_pass!(NeedlessBool => [NEEDLESS_BOOL]);
+
+fn condition_needs_parentheses(e: &Expr<'_>) -> bool {
+ let mut inner = e;
+ while let ExprKind::Binary(_, i, _)
+ | ExprKind::Call(i, _)
+ | ExprKind::Cast(i, _)
+ | ExprKind::Type(i, _)
+ | ExprKind::Index(i, _) = inner.kind
+ {
+ if matches!(
+ i.kind,
+ ExprKind::Block(..)
+ | ExprKind::ConstBlock(..)
+ | ExprKind::If(..)
+ | ExprKind::Loop(..)
+ | ExprKind::Match(..)
+ ) {
+ return true;
+ }
+ inner = i;
+ }
+ false
+}
+
+fn is_parent_stmt(cx: &LateContext<'_>, id: HirId) -> bool {
+ matches!(
+ get_parent_node(cx.tcx, id),
+ Some(Node::Stmt(..) | Node::Block(Block { stmts: &[], .. }))
+ )
+}
+
+impl<'tcx> LateLintPass<'tcx> for NeedlessBool {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ use self::Expression::{Bool, RetBool};
+ if e.span.from_expansion() {
+ return;
+ }
+ if let Some(higher::If {
+ cond,
+ then,
+ r#else: Some(r#else),
+ }) = higher::If::hir(e)
+ {
+ let reduce = |ret, not| {
+ let mut applicability = Applicability::MachineApplicable;
+ let snip = Sugg::hir_with_applicability(cx, cond, "<predicate>", &mut applicability);
+ let mut snip = if not { !snip } else { snip };
+
+ if ret {
+ snip = snip.make_return();
+ }
+
+ if is_else_clause(cx.tcx, e) {
+ snip = snip.blockify();
+ }
+
+ if condition_needs_parentheses(cond) && is_parent_stmt(cx, e.hir_id) {
+ snip = snip.maybe_par();
+ }
+
+ span_lint_and_sugg(
+ cx,
+ NEEDLESS_BOOL,
+ e.span,
+ "this if-then-else expression returns a bool literal",
+ "you can reduce it to",
+ snip.to_string(),
+ applicability,
+ );
+ };
+ if let Some((a, b)) = fetch_bool_block(then).and_then(|a| Some((a, fetch_bool_block(r#else)?))) {
+ match (a, b) {
+ (RetBool(true), RetBool(true)) | (Bool(true), Bool(true)) => {
+ span_lint(
+ cx,
+ NEEDLESS_BOOL,
+ e.span,
+ "this if-then-else expression will always return true",
+ );
+ },
+ (RetBool(false), RetBool(false)) | (Bool(false), Bool(false)) => {
+ span_lint(
+ cx,
+ NEEDLESS_BOOL,
+ e.span,
+ "this if-then-else expression will always return false",
+ );
+ },
+ (RetBool(true), RetBool(false)) => reduce(true, false),
+ (Bool(true), Bool(false)) => reduce(false, false),
+ (RetBool(false), RetBool(true)) => reduce(true, true),
+ (Bool(false), Bool(true)) => reduce(false, true),
+ _ => (),
+ }
+ }
+ }
+ }
+}
+
+declare_lint_pass!(BoolComparison => [BOOL_COMPARISON]);
+
+impl<'tcx> LateLintPass<'tcx> for BoolComparison {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ if e.span.from_expansion() {
+ return;
+ }
+
+ if let ExprKind::Binary(Spanned { node, .. }, ..) = e.kind {
+ let ignore_case = None::<(fn(_) -> _, &str)>;
+ let ignore_no_literal = None::<(fn(_, _) -> _, &str)>;
+ match node {
+ BinOpKind::Eq => {
+ let true_case = Some((|h| h, "equality checks against true are unnecessary"));
+ let false_case = Some((
+ |h: Sugg<'tcx>| !h,
+ "equality checks against false can be replaced by a negation",
+ ));
+ check_comparison(cx, e, true_case, false_case, true_case, false_case, ignore_no_literal);
+ },
+ BinOpKind::Ne => {
+ let true_case = Some((
+ |h: Sugg<'tcx>| !h,
+ "inequality checks against true can be replaced by a negation",
+ ));
+ let false_case = Some((|h| h, "inequality checks against false are unnecessary"));
+ check_comparison(cx, e, true_case, false_case, true_case, false_case, ignore_no_literal);
+ },
+ BinOpKind::Lt => check_comparison(
+ cx,
+ e,
+ ignore_case,
+ Some((|h| h, "greater than checks against false are unnecessary")),
+ Some((
+ |h: Sugg<'tcx>| !h,
+ "less than comparison against true can be replaced by a negation",
+ )),
+ ignore_case,
+ Some((
+ |l: Sugg<'tcx>, r: Sugg<'tcx>| (!l).bit_and(&r),
+ "order comparisons between booleans can be simplified",
+ )),
+ ),
+ BinOpKind::Gt => check_comparison(
+ cx,
+ e,
+ Some((
+ |h: Sugg<'tcx>| !h,
+ "less than comparison against true can be replaced by a negation",
+ )),
+ ignore_case,
+ ignore_case,
+ Some((|h| h, "greater than checks against false are unnecessary")),
+ Some((
+ |l: Sugg<'tcx>, r: Sugg<'tcx>| l.bit_and(&(!r)),
+ "order comparisons between booleans can be simplified",
+ )),
+ ),
+ _ => (),
+ }
+ }
+ }
+}
+
+struct ExpressionInfoWithSpan {
+ one_side_is_unary_not: bool,
+ left_span: Span,
+ right_span: Span,
+}
+
+fn is_unary_not(e: &Expr<'_>) -> (bool, Span) {
+ if let ExprKind::Unary(UnOp::Not, operand) = e.kind {
+ return (true, operand.span);
+ }
+ (false, e.span)
+}
+
+fn one_side_is_unary_not<'tcx>(left_side: &'tcx Expr<'_>, right_side: &'tcx Expr<'_>) -> ExpressionInfoWithSpan {
+ let left = is_unary_not(left_side);
+ let right = is_unary_not(right_side);
+
+ ExpressionInfoWithSpan {
+ one_side_is_unary_not: left.0 != right.0,
+ left_span: left.1,
+ right_span: right.1,
+ }
+}
+
+fn check_comparison<'a, 'tcx>(
+ cx: &LateContext<'tcx>,
+ e: &'tcx Expr<'_>,
+ left_true: Option<(impl FnOnce(Sugg<'a>) -> Sugg<'a>, &str)>,
+ left_false: Option<(impl FnOnce(Sugg<'a>) -> Sugg<'a>, &str)>,
+ right_true: Option<(impl FnOnce(Sugg<'a>) -> Sugg<'a>, &str)>,
+ right_false: Option<(impl FnOnce(Sugg<'a>) -> Sugg<'a>, &str)>,
+ no_literal: Option<(impl FnOnce(Sugg<'a>, Sugg<'a>) -> Sugg<'a>, &str)>,
+) {
+ if let ExprKind::Binary(op, left_side, right_side) = e.kind {
+ let (l_ty, r_ty) = (
+ cx.typeck_results().expr_ty(left_side),
+ cx.typeck_results().expr_ty(right_side),
+ );
+ if is_expn_of(left_side.span, "cfg").is_some() || is_expn_of(right_side.span, "cfg").is_some() {
+ return;
+ }
+ if l_ty.is_bool() && r_ty.is_bool() {
+ let mut applicability = Applicability::MachineApplicable;
+
+ if op.node == BinOpKind::Eq {
+ let expression_info = one_side_is_unary_not(left_side, right_side);
+ if expression_info.one_side_is_unary_not {
+ span_lint_and_sugg(
+ cx,
+ BOOL_COMPARISON,
+ e.span,
+ "this comparison might be written more concisely",
+ "try simplifying it as shown",
+ format!(
+ "{} != {}",
+ snippet_with_applicability(cx, expression_info.left_span, "..", &mut applicability),
+ snippet_with_applicability(cx, expression_info.right_span, "..", &mut applicability)
+ ),
+ applicability,
+ );
+ }
+ }
+
+ match (fetch_bool_expr(left_side), fetch_bool_expr(right_side)) {
+ (Some(true), None) => left_true.map_or((), |(h, m)| {
+ suggest_bool_comparison(cx, e, right_side, applicability, m, h);
+ }),
+ (None, Some(true)) => right_true.map_or((), |(h, m)| {
+ suggest_bool_comparison(cx, e, left_side, applicability, m, h);
+ }),
+ (Some(false), None) => left_false.map_or((), |(h, m)| {
+ suggest_bool_comparison(cx, e, right_side, applicability, m, h);
+ }),
+ (None, Some(false)) => right_false.map_or((), |(h, m)| {
+ suggest_bool_comparison(cx, e, left_side, applicability, m, h);
+ }),
+ (None, None) => no_literal.map_or((), |(h, m)| {
+ let left_side = Sugg::hir_with_applicability(cx, left_side, "..", &mut applicability);
+ let right_side = Sugg::hir_with_applicability(cx, right_side, "..", &mut applicability);
+ span_lint_and_sugg(
+ cx,
+ BOOL_COMPARISON,
+ e.span,
+ m,
+ "try simplifying it as shown",
+ h(left_side, right_side).to_string(),
+ applicability,
+ );
+ }),
+ _ => (),
+ }
+ }
+ }
+}
+
+fn suggest_bool_comparison<'a, 'tcx>(
+ cx: &LateContext<'tcx>,
+ e: &'tcx Expr<'_>,
+ expr: &Expr<'_>,
+ mut applicability: Applicability,
+ message: &str,
+ conv_hint: impl FnOnce(Sugg<'a>) -> Sugg<'a>,
+) {
+ let hint = if expr.span.from_expansion() {
+ if applicability != Applicability::Unspecified {
+ applicability = Applicability::MaybeIncorrect;
+ }
+ Sugg::hir_with_macro_callsite(cx, expr, "..")
+ } else {
+ Sugg::hir_with_applicability(cx, expr, "..", &mut applicability)
+ };
+ span_lint_and_sugg(
+ cx,
+ BOOL_COMPARISON,
+ e.span,
+ message,
+ "try simplifying it as shown",
+ conv_hint(hint).to_string(),
+ applicability,
+ );
+}
+
+enum Expression {
+ Bool(bool),
+ RetBool(bool),
+}
+
+fn fetch_bool_block(expr: &Expr<'_>) -> Option<Expression> {
+ match peel_blocks_with_stmt(expr).kind {
+ ExprKind::Ret(Some(ret)) => Some(Expression::RetBool(fetch_bool_expr(ret)?)),
+ _ => Some(Expression::Bool(fetch_bool_expr(expr)?)),
+ }
+}
+
+fn fetch_bool_expr(expr: &Expr<'_>) -> Option<bool> {
+ if let ExprKind::Lit(ref lit_ptr) = peel_blocks(expr).kind {
+ if let LitKind::Bool(value) = lit_ptr.node {
+ return Some(value);
+ }
+ }
+ None
+}
--- /dev/null
- /// Bad:
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::source::snippet_with_applicability;
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{BindingAnnotation, Mutability, Node, Pat, PatKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for bindings that destructure a reference and borrow the inner
+ /// value with `&ref`.
+ ///
+ /// ### Why is this bad?
+ /// This pattern has no effect in almost all cases.
+ ///
+ /// ### Known problems
+ /// In some cases, `&ref` is needed to avoid a lifetime mismatch error.
+ /// Example:
+ /// ```rust
+ /// fn foo(a: &Option<String>, b: &Option<String>) {
+ /// match (a, b) {
+ /// (None, &ref c) | (&ref c, None) => (),
+ /// (&Some(ref c), _) => (),
+ /// };
+ /// }
+ /// ```
+ ///
+ /// ### Example
- /// let _ = v.iter_mut().filter(|&ref a| a.is_empty());
+ /// ```rust
+ /// let mut v = Vec::<String>::new();
- /// Good:
++ /// # #[allow(unused)]
++ /// v.iter_mut().filter(|&ref a| a.is_empty());
+ /// ```
+ ///
- /// let _ = v.iter_mut().filter(|a| a.is_empty());
++ /// Use instead:
+ /// ```rust
+ /// let mut v = Vec::<String>::new();
++ /// # #[allow(unused)]
++ /// v.iter_mut().filter(|a| a.is_empty());
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NEEDLESS_BORROWED_REFERENCE,
+ complexity,
+ "destructuring a reference and borrowing the inner value"
+}
+
+declare_lint_pass!(NeedlessBorrowedRef => [NEEDLESS_BORROWED_REFERENCE]);
+
+impl<'tcx> LateLintPass<'tcx> for NeedlessBorrowedRef {
+ fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) {
+ if pat.span.from_expansion() {
+ // OK, simple enough, lints doesn't check in macro.
+ return;
+ }
+
+ if_chain! {
+ // Only lint immutable refs, because `&mut ref T` may be useful.
+ if let PatKind::Ref(sub_pat, Mutability::Not) = pat.kind;
+
+ // Check sub_pat got a `ref` keyword (excluding `ref mut`).
+ if let PatKind::Binding(BindingAnnotation::Ref, .., spanned_name, _) = sub_pat.kind;
+ let parent_id = cx.tcx.hir().get_parent_node(pat.hir_id);
+ if let Some(parent_node) = cx.tcx.hir().find(parent_id);
+ then {
+ // do not recurse within patterns, as they may have other references
+ // XXXManishearth we can relax this constraint if we only check patterns
+ // with a single ref pattern inside them
+ if let Node::Pat(_) = parent_node {
+ return;
+ }
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_then(cx, NEEDLESS_BORROWED_REFERENCE, pat.span,
+ "this pattern takes a reference on something that is being de-referenced",
+ |diag| {
+ let hint = snippet_with_applicability(cx, spanned_name.span, "..", &mut applicability).into_owned();
+ diag.span_suggestion(
+ pat.span,
+ "try removing the `&ref` part and just keep",
+ hint,
+ applicability,
+ );
+ });
+ }
+ }
+ }
+}
--- /dev/null
- #[clippy::version = "1.58.0"]
+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
+ /// };
+ /// ```
- .map(|assignment| Some((assignment.span.until(assignment.rhs_span), String::new())))
- .chain(assignments.iter().map(|assignment| {
- Some((
++ #[clippy::version = "1.59.0"]
+ 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()
- String::new(),
- ))
- }))
- .collect::<Option<Vec<(Span, String)>>>()?;
++ .flat_map(|assignment| {
++ [
++ assignment.span.until(assignment.rhs_span),
+ assignment.rhs_span.shrink_to_hi().with_hi(assignment.span.hi()),
++ ]
++ })
++ .map(|span| (span, String::new()))
++ .collect::<Vec<(Span, String)>>();
+
+ 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",
+ "",
+ 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",
+ ";",
+ 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",
+ ";",
+ 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::{
++ diagnostics::span_lint_and_then,
++ higher,
++ source::{snippet, snippet_with_applicability},
++};
++
++use rustc_ast::ast;
++use rustc_errors::Applicability;
++use rustc_hir::{Expr, ExprKind};
++
++use rustc_lint::{LateContext, LateLintPass};
++use rustc_session::{declare_lint_pass, declare_tool_lint};
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// The lint checks for parenthesis on literals in range statements that are
++ /// superfluous.
++ ///
++ /// ### Why is this bad?
++ /// Having superfluous parenthesis makes the code less readable
++ /// overhead when reading.
++ ///
++ /// ### Example
++ ///
++ /// ```rust
++ /// for i in (0)..10 {
++ /// println!("{i}");
++ /// }
++ /// ```
++ ///
++ /// Use instead:
++ ///
++ /// ```rust
++ /// for i in 0..10 {
++ /// println!("{i}");
++ /// }
++ /// ```
++ #[clippy::version = "1.63.0"]
++ pub NEEDLESS_PARENS_ON_RANGE_LITERALS,
++ style,
++ "needless parenthesis on range literals can be removed"
++}
++
++declare_lint_pass!(NeedlessParensOnRangeLiterals => [NEEDLESS_PARENS_ON_RANGE_LITERALS]);
++
++fn snippet_enclosed_in_parenthesis(snippet: &str) -> bool {
++ snippet.starts_with('(') && snippet.ends_with(')')
++}
++
++fn check_for_parens(cx: &LateContext<'_>, e: &Expr<'_>, is_start: bool) {
++ if is_start &&
++ let ExprKind::Lit(ref literal) = e.kind &&
++ let ast::LitKind::Float(_sym, ast::LitFloatType::Unsuffixed) = literal.node
++ {
++ // don't check floating point literals on the start expression of a range
++ return;
++ }
++ if_chain! {
++ if let ExprKind::Lit(ref literal) = e.kind;
++ // the indicator that parenthesis surround the literal is that the span of the expression and the literal differ
++ if (literal.span.data().hi - literal.span.data().lo) != (e.span.data().hi - e.span.data().lo);
++ // inspect the source code of the expression for parenthesis
++ if snippet_enclosed_in_parenthesis(&snippet(cx, e.span, ""));
++ then {
++ let mut applicability = Applicability::MachineApplicable;
++ span_lint_and_then(cx, NEEDLESS_PARENS_ON_RANGE_LITERALS, e.span,
++ "needless parenthesis on range literals can be removed",
++ |diag| {
++ let suggestion = snippet_with_applicability(cx, literal.span, "_", &mut applicability);
++ diag.span_suggestion(e.span, "try", suggestion, applicability);
++ });
++ }
++ }
++}
++
++impl<'tcx> LateLintPass<'tcx> for NeedlessParensOnRangeLiterals {
++ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
++ if let Some(higher::Range { start, end, .. }) = higher::Range::hir(expr) {
++ if let Some(start) = start {
++ check_for_parens(cx, start, true);
++ }
++ if let Some(end) = end {
++ check_for_parens(cx, end, false);
++ }
++ }
++ }
++}
--- /dev/null
- ///
- /// // Bad
+use clippy_utils::diagnostics::span_lint;
+use rustc_hir::{Expr, ExprKind};
+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 needlessly including a base struct on update
+ /// when all fields are changed anyway.
+ ///
+ /// This lint is not applied to structs marked with
+ /// [non_exhaustive](https://doc.rust-lang.org/reference/attributes/type_system.html).
+ ///
+ /// ### Why is this bad?
+ /// This will cost resources (because the base has to be
+ /// somewhere), and make the code less readable.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # struct Point {
+ /// # x: i32,
+ /// # y: i32,
+ /// # z: i32,
+ /// # }
+ /// # let zero_point = Point { x: 0, y: 0, z: 0 };
- /// // Ok
+ /// Point {
+ /// x: 1,
+ /// y: 1,
+ /// z: 1,
+ /// ..zero_point
+ /// };
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust,ignore
++ /// // Missing field `z`
+ /// Point {
+ /// x: 1,
+ /// y: 1,
+ /// ..zero_point
+ /// };
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NEEDLESS_UPDATE,
+ complexity,
+ "using `Foo { ..base }` when there are no missing fields"
+}
+
+declare_lint_pass!(NeedlessUpdate => [NEEDLESS_UPDATE]);
+
+impl<'tcx> LateLintPass<'tcx> for NeedlessUpdate {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if let ExprKind::Struct(_, fields, Some(base)) = expr.kind {
+ let ty = cx.typeck_results().expr_ty(expr);
+ if let ty::Adt(def, _) = ty.kind() {
+ if fields.len() == def.non_enum_variant().fields.len()
+ && !def.variant(0_usize.into()).is_field_list_non_exhaustive()
+ {
+ span_lint(
+ cx,
+ NEEDLESS_UPDATE,
+ base.span,
+ "struct update has no effect, all the fields in the struct have already been specified",
+ );
+ }
+ }
+ }
+ }
+}
--- /dev/null
- /// use std::cmp::Ordering;
- ///
- /// // Bad
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::ty::implements_trait;
+use clippy_utils::{self, get_trait_def_id, paths};
+use if_chain::if_chain;
+use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp};
+use rustc_lint::{LateContext, LateLintPass, 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 the usage of negated comparison operators on types which only implement
+ /// `PartialOrd` (e.g., `f64`).
+ ///
+ /// ### Why is this bad?
+ /// These operators make it easy to forget that the underlying types actually allow not only three
+ /// potential Orderings (Less, Equal, Greater) but also a fourth one (Uncomparable). This is
+ /// especially easy to miss if the operator based comparison result is negated.
+ ///
+ /// ### Example
+ /// ```rust
- /// let _not_less_or_equal = !(a <= b);
+ /// let a = 1.0;
+ /// let b = f64::NAN;
+ ///
- /// // Good
- /// let a = 1.0;
- /// let b = f64::NAN;
++ /// let not_less_or_equal = !(a <= b);
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// use std::cmp::Ordering;
++ /// # let a = 1.0;
++ /// # let b = f64::NAN;
+ ///
+ /// let _not_less_or_equal = match a.partial_cmp(&b) {
+ /// None | Some(Ordering::Greater) => true,
+ /// _ => false,
+ /// };
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NEG_CMP_OP_ON_PARTIAL_ORD,
+ complexity,
+ "The use of negated comparison operators on partially ordered types may produce confusing code."
+}
+
+declare_lint_pass!(NoNegCompOpForPartialOrd => [NEG_CMP_OP_ON_PARTIAL_ORD]);
+
+impl<'tcx> LateLintPass<'tcx> for NoNegCompOpForPartialOrd {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! {
+
+ if !in_external_macro(cx.sess(), expr.span);
+ if let ExprKind::Unary(UnOp::Not, inner) = expr.kind;
+ if let ExprKind::Binary(ref op, left, _) = inner.kind;
+ if let BinOpKind::Le | BinOpKind::Ge | BinOpKind::Lt | BinOpKind::Gt = op.node;
+
+ then {
+
+ let ty = cx.typeck_results().expr_ty(left);
+
+ let implements_ord = {
+ if let Some(id) = get_trait_def_id(cx, &paths::ORD) {
+ implements_trait(cx, ty, id, &[])
+ } else {
+ return;
+ }
+ };
+
+ let implements_partial_ord = {
+ if let Some(id) = cx.tcx.lang_items().partial_ord_trait() {
+ implements_trait(cx, ty, id, &[])
+ } else {
+ return;
+ }
+ };
+
+ if implements_partial_ord && !implements_ord {
+ span_lint(
+ cx,
+ NEG_CMP_OP_ON_PARTIAL_ORD,
+ expr.span,
+ "the use of negated comparison operators on partially ordered \
+ types produces code that is hard to read and refactor, please \
+ consider using the `partial_cmp` method instead, to make it \
+ clear that the two values could be incomparable"
+ );
+ }
+ }
+ }
+ }
+}
--- /dev/null
- /// ```ignore
- /// // Bad
+use clippy_utils::consts::{self, Constant};
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_with_applicability;
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp};
+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 multiplication by -1 as a form of negation.
+ ///
+ /// ### Why is this bad?
+ /// It's more readable to just negate.
+ ///
+ /// ### Known problems
+ /// This only catches integers (for now).
+ ///
+ /// ### Example
- /// // Good
- /// let b = -x;
++ /// ```rust,ignore
+ /// let a = x * -1;
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust,ignore
++ /// let a = -x;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NEG_MULTIPLY,
+ style,
+ "multiplying integers by `-1`"
+}
+
+declare_lint_pass!(NegMultiply => [NEG_MULTIPLY]);
+
+impl<'tcx> LateLintPass<'tcx> for NegMultiply {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ if let ExprKind::Binary(ref op, left, right) = e.kind {
+ if BinOpKind::Mul == op.node {
+ match (&left.kind, &right.kind) {
+ (&ExprKind::Unary(..), &ExprKind::Unary(..)) => {},
+ (&ExprKind::Unary(UnOp::Neg, lit), _) => check_mul(cx, e.span, lit, right),
+ (_, &ExprKind::Unary(UnOp::Neg, lit)) => check_mul(cx, e.span, lit, left),
+ _ => {},
+ }
+ }
+ }
+ }
+}
+
+fn check_mul(cx: &LateContext<'_>, span: Span, lit: &Expr<'_>, exp: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Lit(ref l) = lit.kind;
+ if consts::lit_to_mir_constant(&l.node, cx.typeck_results().expr_ty_opt(lit)) == Constant::Int(1);
+ if cx.typeck_results().expr_ty(exp).is_integral();
+
+ then {
+ let mut applicability = Applicability::MachineApplicable;
+ let suggestion = format!("-{}", snippet_with_applicability(cx, exp.span, "..", &mut applicability));
+ span_lint_and_sugg(
+ cx,
+ NEG_MULTIPLY,
+ span,
+ "this multiplication by -1 can be written more succinctly",
+ "consider using",
+ suggestion,
+ applicability,
+ );
+ }
+ }
+}
--- /dev/null
- /// // Bad.
+//! Checks for uses of const which the type is not `Freeze` (`Cell`-free).
+//!
+//! This lint is **warn** by default.
+
+use std::ptr;
+
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::in_constant;
+use if_chain::if_chain;
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::def_id::DefId;
+use rustc_hir::{
+ BodyId, Expr, ExprKind, HirId, Impl, ImplItem, ImplItemKind, Item, ItemKind, Node, TraitItem, TraitItemKind, UnOp,
+};
+use rustc_lint::{LateContext, LateLintPass, Lint};
+use rustc_middle::mir;
+use rustc_middle::mir::interpret::{ConstValue, ErrorHandled};
+use rustc_middle::ty::adjustment::Adjust;
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::{InnerSpan, Span, DUMMY_SP};
+use rustc_typeck::hir_ty_to_ty;
+
+// FIXME: this is a correctness problem but there's no suitable
+// warn-by-default category.
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for declaration of `const` items which is interior
+ /// mutable (e.g., contains a `Cell`, `Mutex`, `AtomicXxxx`, etc.).
+ ///
+ /// ### Why is this bad?
+ /// Consts are copied everywhere they are referenced, i.e.,
+ /// every time you refer to the const a fresh instance of the `Cell` or `Mutex`
+ /// or `AtomicXxxx` will be created, which defeats the whole purpose of using
+ /// these types in the first place.
+ ///
+ /// The `const` should better be replaced by a `static` item if a global
+ /// variable is wanted, or replaced by a `const fn` if a constructor is wanted.
+ ///
+ /// ### Known problems
+ /// A "non-constant" const item is a legacy way to supply an
+ /// initialized value to downstream `static` items (e.g., the
+ /// `std::sync::ONCE_INIT` constant). In this case the use of `const` is legit,
+ /// and this lint should be suppressed.
+ ///
+ /// Even though the lint avoids triggering on a constant whose type has enums that have variants
+ /// with interior mutability, and its value uses non interior mutable variants (see
+ /// [#3962](https://github.com/rust-lang/rust-clippy/issues/3962) and
+ /// [#3825](https://github.com/rust-lang/rust-clippy/issues/3825) for examples);
+ /// it complains about associated constants without default values only based on its types;
+ /// which might not be preferable.
+ /// There're other enums plus associated constants cases that the lint cannot handle.
+ ///
+ /// Types that have underlying or potential interior mutability trigger the lint whether
+ /// the interior mutable field is used or not. See issues
+ /// [#5812](https://github.com/rust-lang/rust-clippy/issues/5812) and
+ ///
+ /// ### Example
+ /// ```rust
+ /// use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
+ ///
- /// // Good.
+ /// const CONST_ATOM: AtomicUsize = AtomicUsize::new(12);
+ /// CONST_ATOM.store(6, SeqCst); // the content of the atomic is unchanged
+ /// assert_eq!(CONST_ATOM.load(SeqCst), 12); // because the CONST_ATOM in these lines are distinct
++ /// ```
+ ///
- /// // Bad.
++ /// Use instead:
++ /// ```rust
++ /// # use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
+ /// static STATIC_ATOM: AtomicUsize = AtomicUsize::new(15);
+ /// STATIC_ATOM.store(9, SeqCst);
+ /// assert_eq!(STATIC_ATOM.load(SeqCst), 9); // use a `static` item to refer to the same instance
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DECLARE_INTERIOR_MUTABLE_CONST,
+ style,
+ "declaring `const` with interior mutability"
+}
+
+// FIXME: this is a correctness problem but there's no suitable
+// warn-by-default category.
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks if `const` items which is interior mutable (e.g.,
+ /// contains a `Cell`, `Mutex`, `AtomicXxxx`, etc.) has been borrowed directly.
+ ///
+ /// ### Why is this bad?
+ /// Consts are copied everywhere they are referenced, i.e.,
+ /// every time you refer to the const a fresh instance of the `Cell` or `Mutex`
+ /// or `AtomicXxxx` will be created, which defeats the whole purpose of using
+ /// these types in the first place.
+ ///
+ /// The `const` value should be stored inside a `static` item.
+ ///
+ /// ### Known problems
+ /// When an enum has variants with interior mutability, use of its non
+ /// interior mutable variants can generate false positives. See issue
+ /// [#3962](https://github.com/rust-lang/rust-clippy/issues/3962)
+ ///
+ /// Types that have underlying or potential interior mutability trigger the lint whether
+ /// the interior mutable field is used or not. See issues
+ /// [#5812](https://github.com/rust-lang/rust-clippy/issues/5812) and
+ /// [#3825](https://github.com/rust-lang/rust-clippy/issues/3825)
+ ///
+ /// ### Example
+ /// ```rust
+ /// use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
+ /// const CONST_ATOM: AtomicUsize = AtomicUsize::new(12);
+ ///
- /// // Good.
+ /// CONST_ATOM.store(6, SeqCst); // the content of the atomic is unchanged
+ /// assert_eq!(CONST_ATOM.load(SeqCst), 12); // because the CONST_ATOM in these lines are distinct
++ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
++ /// const CONST_ATOM: AtomicUsize = AtomicUsize::new(12);
+ ///
+ /// static STATIC_ATOM: AtomicUsize = CONST_ATOM;
+ /// STATIC_ATOM.store(9, SeqCst);
+ /// assert_eq!(STATIC_ATOM.load(SeqCst), 9); // use a `static` item to refer to the same instance
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub BORROW_INTERIOR_MUTABLE_CONST,
+ style,
+ "referencing `const` with interior mutability"
+}
+
+fn is_unfrozen<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
+ // Ignore types whose layout is unknown since `is_freeze` reports every generic types as `!Freeze`,
+ // making it indistinguishable from `UnsafeCell`. i.e. it isn't a tool to prove a type is
+ // 'unfrozen'. However, this code causes a false negative in which
+ // a type contains a layout-unknown type, but also an unsafe cell like `const CELL: Cell<T>`.
+ // Yet, it's better than `ty.has_type_flags(TypeFlags::HAS_TY_PARAM | TypeFlags::HAS_PROJECTION)`
+ // since it works when a pointer indirection involves (`Cell<*const T>`).
+ // Making up a `ParamEnv` where every generic params and assoc types are `Freeze`is another option;
+ // but I'm not sure whether it's a decent way, if possible.
+ cx.tcx.layout_of(cx.param_env.and(ty)).is_ok() && !ty.is_freeze(cx.tcx.at(DUMMY_SP), cx.param_env)
+}
+
+fn is_value_unfrozen_raw<'tcx>(
+ cx: &LateContext<'tcx>,
+ result: Result<ConstValue<'tcx>, ErrorHandled>,
+ ty: Ty<'tcx>,
+) -> bool {
+ fn inner<'tcx>(cx: &LateContext<'tcx>, val: mir::ConstantKind<'tcx>) -> bool {
+ match val.ty().kind() {
+ // the fact that we have to dig into every structs to search enums
+ // leads us to the point checking `UnsafeCell` directly is the only option.
+ ty::Adt(ty_def, ..) if Some(ty_def.did()) == cx.tcx.lang_items().unsafe_cell_type() => true,
+ ty::Array(..) | ty::Adt(..) | ty::Tuple(..) => {
+ let val = cx.tcx.destructure_mir_constant(cx.param_env, val);
+ val.fields.iter().any(|field| inner(cx, *field))
+ },
+ _ => false,
+ }
+ }
+ result.map_or_else(
+ |err| {
+ // Consider `TooGeneric` cases as being unfrozen.
+ // This causes a false positive where an assoc const whose type is unfrozen
+ // have a value that is a frozen variant with a generic param (an example is
+ // `declare_interior_mutable_const::enums::BothOfCellAndGeneric::GENERIC_VARIANT`).
+ // However, it prevents a number of false negatives that is, I think, important:
+ // 1. assoc consts in trait defs referring to consts of themselves
+ // (an example is `declare_interior_mutable_const::traits::ConcreteTypes::ANOTHER_ATOMIC`).
+ // 2. a path expr referring to assoc consts whose type is doesn't have
+ // any frozen variants in trait defs (i.e. without substitute for `Self`).
+ // (e.g. borrowing `borrow_interior_mutable_const::trait::ConcreteTypes::ATOMIC`)
+ // 3. similar to the false positive above;
+ // but the value is an unfrozen variant, or the type has no enums. (An example is
+ // `declare_interior_mutable_const::enums::BothOfCellAndGeneric::UNFROZEN_VARIANT`
+ // and `declare_interior_mutable_const::enums::BothOfCellAndGeneric::NO_ENUM`).
+ // One might be able to prevent these FNs correctly, and replace this with `false`;
+ // e.g. implementing `has_frozen_variant` described above, and not running this function
+ // when the type doesn't have any frozen variants would be the 'correct' way for the 2nd
+ // case (that actually removes another suboptimal behavior (I won't say 'false positive') where,
+ // similar to 2., but with the a frozen variant) (e.g. borrowing
+ // `borrow_interior_mutable_const::enums::AssocConsts::TO_BE_FROZEN_VARIANT`).
+ // I chose this way because unfrozen enums as assoc consts are rare (or, hopefully, none).
+ err == ErrorHandled::TooGeneric
+ },
+ |val| inner(cx, mir::ConstantKind::from_value(val, ty)),
+ )
+}
+
+fn is_value_unfrozen_poly<'tcx>(cx: &LateContext<'tcx>, body_id: BodyId, ty: Ty<'tcx>) -> bool {
+ let result = cx.tcx.const_eval_poly(body_id.hir_id.owner.to_def_id());
+ is_value_unfrozen_raw(cx, result, ty)
+}
+
+fn is_value_unfrozen_expr<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId, def_id: DefId, ty: Ty<'tcx>) -> bool {
+ let substs = cx.typeck_results().node_substs(hir_id);
+
+ let result = cx.tcx.const_eval_resolve(
+ cx.param_env,
+ ty::Unevaluated::new(ty::WithOptConstParam::unknown(def_id), substs),
+ None,
+ );
+ is_value_unfrozen_raw(cx, result, ty)
+}
+
+#[derive(Copy, Clone)]
+enum Source {
+ Item { item: Span },
+ Assoc { item: Span },
+ Expr { expr: Span },
+}
+
+impl Source {
+ #[must_use]
+ fn lint(&self) -> (&'static Lint, &'static str, Span) {
+ match self {
+ Self::Item { item } | Self::Assoc { item, .. } => (
+ DECLARE_INTERIOR_MUTABLE_CONST,
+ "a `const` item should never be interior mutable",
+ *item,
+ ),
+ Self::Expr { expr } => (
+ BORROW_INTERIOR_MUTABLE_CONST,
+ "a `const` item with interior mutability should not be borrowed",
+ *expr,
+ ),
+ }
+ }
+}
+
+fn lint(cx: &LateContext<'_>, source: Source) {
+ let (lint, msg, span) = source.lint();
+ span_lint_and_then(cx, lint, span, msg, |diag| {
+ if span.from_expansion() {
+ return; // Don't give suggestions into macros.
+ }
+ match source {
+ Source::Item { .. } => {
+ let const_kw_span = span.from_inner(InnerSpan::new(0, 5));
+ diag.span_label(const_kw_span, "make this a static item (maybe with lazy_static)");
+ },
+ Source::Assoc { .. } => (),
+ Source::Expr { .. } => {
+ diag.help("assign this const to a local or static variable, and use the variable here");
+ },
+ }
+ });
+}
+
+declare_lint_pass!(NonCopyConst => [DECLARE_INTERIOR_MUTABLE_CONST, BORROW_INTERIOR_MUTABLE_CONST]);
+
+impl<'tcx> LateLintPass<'tcx> for NonCopyConst {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, it: &'tcx Item<'_>) {
+ if let ItemKind::Const(hir_ty, body_id) = it.kind {
+ let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+
+ if is_unfrozen(cx, ty) && is_value_unfrozen_poly(cx, body_id, ty) {
+ lint(cx, Source::Item { item: it.span });
+ }
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, trait_item: &'tcx TraitItem<'_>) {
+ if let TraitItemKind::Const(hir_ty, body_id_opt) = &trait_item.kind {
+ let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+
+ // Normalize assoc types because ones originated from generic params
+ // bounded other traits could have their bound.
+ let normalized = cx.tcx.normalize_erasing_regions(cx.param_env, ty);
+ if is_unfrozen(cx, normalized)
+ // When there's no default value, lint it only according to its type;
+ // in other words, lint consts whose value *could* be unfrozen, not definitely is.
+ // This feels inconsistent with how the lint treats generic types,
+ // which avoids linting types which potentially become unfrozen.
+ // One could check whether an unfrozen type have a *frozen variant*
+ // (like `body_id_opt.map_or_else(|| !has_frozen_variant(...), ...)`),
+ // and do the same as the case of generic types at impl items.
+ // Note that it isn't sufficient to check if it has an enum
+ // since all of that enum's variants can be unfrozen:
+ // i.e. having an enum doesn't necessary mean a type has a frozen variant.
+ // And, implementing it isn't a trivial task; it'll probably end up
+ // re-implementing the trait predicate evaluation specific to `Freeze`.
+ && body_id_opt.map_or(true, |body_id| is_value_unfrozen_poly(cx, body_id, normalized))
+ {
+ lint(cx, Source::Assoc { item: trait_item.span });
+ }
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx ImplItem<'_>) {
+ if let ImplItemKind::Const(hir_ty, body_id) = &impl_item.kind {
+ let item_def_id = cx.tcx.hir().get_parent_item(impl_item.hir_id());
+ let item = cx.tcx.hir().expect_item(item_def_id);
+
+ match &item.kind {
+ ItemKind::Impl(Impl {
+ of_trait: Some(of_trait_ref),
+ ..
+ }) => {
+ if_chain! {
+ // Lint a trait impl item only when the definition is a generic type,
+ // assuming an assoc const is not meant to be an interior mutable type.
+ if let Some(of_trait_def_id) = of_trait_ref.trait_def_id();
+ if let Some(of_assoc_item) = cx
+ .tcx
+ .associated_item(impl_item.def_id)
+ .trait_item_def_id;
+ if cx
+ .tcx
+ .layout_of(cx.tcx.param_env(of_trait_def_id).and(
+ // Normalize assoc types because ones originated from generic params
+ // bounded other traits could have their bound at the trait defs;
+ // and, in that case, the definition is *not* generic.
+ cx.tcx.normalize_erasing_regions(
+ cx.tcx.param_env(of_trait_def_id),
+ cx.tcx.type_of(of_assoc_item),
+ ),
+ ))
+ .is_err();
+ // If there were a function like `has_frozen_variant` described above,
+ // we should use here as a frozen variant is a potential to be frozen
+ // similar to unknown layouts.
+ // e.g. `layout_of(...).is_err() || has_frozen_variant(...);`
+ let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+ let normalized = cx.tcx.normalize_erasing_regions(cx.param_env, ty);
+ if is_unfrozen(cx, normalized);
+ if is_value_unfrozen_poly(cx, *body_id, normalized);
+ then {
+ lint(
+ cx,
+ Source::Assoc {
+ item: impl_item.span,
+ },
+ );
+ }
+ }
+ },
+ ItemKind::Impl(Impl { of_trait: None, .. }) => {
+ let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+ // Normalize assoc types originated from generic params.
+ let normalized = cx.tcx.normalize_erasing_regions(cx.param_env, ty);
+
+ if is_unfrozen(cx, ty) && is_value_unfrozen_poly(cx, *body_id, normalized) {
+ lint(cx, Source::Assoc { item: impl_item.span });
+ }
+ },
+ _ => (),
+ }
+ }
+ }
+
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if let ExprKind::Path(qpath) = &expr.kind {
+ // Only lint if we use the const item inside a function.
+ if in_constant(cx, expr.hir_id) {
+ return;
+ }
+
+ // Make sure it is a const item.
+ let item_def_id = match cx.qpath_res(qpath, expr.hir_id) {
+ Res::Def(DefKind::Const | DefKind::AssocConst, did) => did,
+ _ => return,
+ };
+
+ // Climb up to resolve any field access and explicit referencing.
+ let mut cur_expr = expr;
+ let mut dereferenced_expr = expr;
+ let mut needs_check_adjustment = true;
+ loop {
+ let parent_id = cx.tcx.hir().get_parent_node(cur_expr.hir_id);
+ if parent_id == cur_expr.hir_id {
+ break;
+ }
+ if let Some(Node::Expr(parent_expr)) = cx.tcx.hir().find(parent_id) {
+ match &parent_expr.kind {
+ ExprKind::AddrOf(..) => {
+ // `&e` => `e` must be referenced.
+ needs_check_adjustment = false;
+ },
+ ExprKind::Field(..) => {
+ needs_check_adjustment = true;
+
+ // Check whether implicit dereferences happened;
+ // if so, no need to go further up
+ // because of the same reason as the `ExprKind::Unary` case.
+ if cx
+ .typeck_results()
+ .expr_adjustments(dereferenced_expr)
+ .iter()
+ .any(|adj| matches!(adj.kind, Adjust::Deref(_)))
+ {
+ break;
+ }
+
+ dereferenced_expr = parent_expr;
+ },
+ ExprKind::Index(e, _) if ptr::eq(&**e, cur_expr) => {
+ // `e[i]` => desugared to `*Index::index(&e, i)`,
+ // meaning `e` must be referenced.
+ // no need to go further up since a method call is involved now.
+ needs_check_adjustment = false;
+ break;
+ },
+ ExprKind::Unary(UnOp::Deref, _) => {
+ // `*e` => desugared to `*Deref::deref(&e)`,
+ // meaning `e` must be referenced.
+ // no need to go further up since a method call is involved now.
+ needs_check_adjustment = false;
+ break;
+ },
+ _ => break,
+ }
+ cur_expr = parent_expr;
+ } else {
+ break;
+ }
+ }
+
+ let ty = if needs_check_adjustment {
+ let adjustments = cx.typeck_results().expr_adjustments(dereferenced_expr);
+ if let Some(i) = adjustments
+ .iter()
+ .position(|adj| matches!(adj.kind, Adjust::Borrow(_) | Adjust::Deref(_)))
+ {
+ if i == 0 {
+ cx.typeck_results().expr_ty(dereferenced_expr)
+ } else {
+ adjustments[i - 1].target
+ }
+ } else {
+ // No borrow adjustments means the entire const is moved.
+ return;
+ }
+ } else {
+ cx.typeck_results().expr_ty(dereferenced_expr)
+ };
+
+ if is_unfrozen(cx, ty) && is_value_unfrozen_expr(cx, expr.hir_id, item_def_id, ty) {
+ lint(cx, Source::Expr { expr: expr.span });
+ }
+ }
+ }
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::span_lint_and_then;
+use rustc_ast::ast::{Expr, ExprKind};
+use rustc_ast::token::{Lit, LitKind};
+use rustc_errors::Applicability;
+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::Span;
+use std::fmt::Write;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `\0` escapes in string and byte literals that look like octal
+ /// character escapes in C.
+ ///
+ /// ### Why is this bad?
+ ///
+ /// C and other languages support octal character escapes in strings, where
+ /// a backslash is followed by up to three octal digits. For example, `\033`
+ /// stands for the ASCII character 27 (ESC). Rust does not support this
+ /// notation, but has the escape code `\0` which stands for a null
+ /// byte/character, and any following digits do not form part of the escape
+ /// sequence. Therefore, `\033` is not a compiler error but the result may
+ /// be surprising.
+ ///
+ /// ### Known problems
+ /// The actual meaning can be the intended one. `\x00` can be used in these
+ /// cases to be unambiguous.
+ ///
+ /// The lint does not trigger for format strings in `print!()`, `write!()`
+ /// and friends since the string is already preprocessed when Clippy lints
+ /// can see it.
+ ///
+ /// # Example
+ /// ```rust
- /// // Good
+ /// let one = "\033[1m Bold? \033[0m"; // \033 intended as escape
+ /// let two = "\033\0"; // \033 intended as null-3-3
++ /// ```
+ ///
- #[clippy::version = "1.58.0"]
++ /// Use instead:
++ /// ```rust
+ /// let one = "\x1b[1mWill this be bold?\x1b[0m";
+ /// let two = "\x0033\x00";
+ /// ```
++ #[clippy::version = "1.59.0"]
+ pub OCTAL_ESCAPES,
+ suspicious,
+ "string escape sequences looking like octal characters"
+}
+
+declare_lint_pass!(OctalEscapes => [OCTAL_ESCAPES]);
+
+impl EarlyLintPass for OctalEscapes {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+
+ if let ExprKind::Lit(lit) = &expr.kind {
+ if matches!(lit.token.kind, LitKind::Str) {
+ check_lit(cx, &lit.token, lit.span, true);
+ } else if matches!(lit.token.kind, LitKind::ByteStr) {
+ check_lit(cx, &lit.token, lit.span, false);
+ }
+ }
+ }
+}
+
+fn check_lit(cx: &EarlyContext<'_>, lit: &Lit, span: Span, is_string: bool) {
+ let contents = lit.symbol.as_str();
+ let mut iter = contents.char_indices().peekable();
+ let mut found = vec![];
+
+ // go through the string, looking for \0[0-7][0-7]?
+ while let Some((from, ch)) = iter.next() {
+ if ch == '\\' {
+ if let Some((_, '0')) = iter.next() {
+ // collect up to two further octal digits
+ if let Some((mut to, '0'..='7')) = iter.next() {
+ if let Some((_, '0'..='7')) = iter.peek() {
+ to += 1;
+ }
+ found.push((from, to + 1));
+ }
+ }
+ }
+ }
+
+ if found.is_empty() {
+ return;
+ }
+
+ // construct two suggestion strings, one with \x escapes with octal meaning
+ // as in C, and one with \x00 for null bytes.
+ let mut suggest_1 = if is_string { "\"" } else { "b\"" }.to_string();
+ let mut suggest_2 = suggest_1.clone();
+ let mut index = 0;
+ for (from, to) in found {
+ suggest_1.push_str(&contents[index..from]);
+ suggest_2.push_str(&contents[index..from]);
+
+ // construct a replacement escape
+ // the maximum value is \077, or \x3f, so u8 is sufficient here
+ if let Ok(n) = u8::from_str_radix(&contents[from + 1..to], 8) {
+ write!(suggest_1, "\\x{:02x}", n).unwrap();
+ }
+
+ // append the null byte as \x00 and the following digits literally
+ suggest_2.push_str("\\x00");
+ suggest_2.push_str(&contents[from + 2..to]);
+
+ index = to;
+ }
+ suggest_1.push_str(&contents[index..]);
+ suggest_1.push('"');
+ suggest_2.push_str(&contents[index..]);
+ suggest_2.push('"');
+
+ span_lint_and_then(
+ cx,
+ OCTAL_ESCAPES,
+ span,
+ &format!(
+ "octal-looking escape in {} literal",
+ if is_string { "string" } else { "byte string" }
+ ),
+ |diag| {
+ diag.help(&format!(
+ "octal escapes are not supported, `\\0` is always a null {}",
+ if is_string { "character" } else { "byte" }
+ ));
+ // suggestion 1: equivalent hex escape
+ diag.span_suggestion(
+ span,
+ "if an octal escape was intended, use the hexadecimal representation instead",
+ suggest_1,
+ Applicability::MaybeIncorrect,
+ );
+ // suggestion 2: unambiguous null byte
+ diag.span_suggestion(
+ span,
+ &format!(
+ "if the null {} is intended, disambiguate using",
+ if is_string { "character" } else { "byte" }
+ ),
+ suggest_2,
+ Applicability::MaybeIncorrect,
+ );
+ },
+ );
+}
--- /dev/null
- #[clippy::version = "1.60.0"]
+use std::collections::VecDeque;
+
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::is_lint_allowed;
+use itertools::{izip, Itertools};
+use rustc_ast::{walk_list, Label, Mutability};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_errors::Applicability;
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::def_id::DefId;
+use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
+use rustc_hir::intravisit::{walk_expr, walk_stmt, FnKind, Visitor};
+use rustc_hir::{
+ Arm, Block, Body, Expr, ExprKind, Guard, HirId, ImplicitSelfKind, Let, Local, Pat, PatKind, Path, PathSegment,
+ QPath, Stmt, StmtKind, TyKind, UnOp,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_middle::ty::{Ty, TyCtxt, TypeckResults};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::kw;
+use rustc_span::symbol::Ident;
+use rustc_span::Span;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for arguments that are only used in recursion with no side-effects.
+ ///
+ /// ### Why is this bad?
+ /// It could contain a useless calculation and can make function simpler.
+ ///
+ /// The arguments can be involved in calculations and assignments but as long as
+ /// the calculations have no side-effects (function calls or mutating dereference)
+ /// and the assigned variables are also only in recursion, it is useless.
+ ///
+ /// ### Known problems
+ /// Too many code paths in the linting code are currently untested and prone to produce false
+ /// positives or are prone to have performance implications.
+ ///
+ /// In some cases, this would not catch all useless arguments.
+ ///
+ /// ```rust
+ /// fn foo(a: usize, b: usize) -> usize {
+ /// let f = |x| x + 1;
+ ///
+ /// if a == 0 {
+ /// 1
+ /// } else {
+ /// foo(a - 1, f(b))
+ /// }
+ /// }
+ /// ```
+ ///
+ /// For example, the argument `b` is only used in recursion, but the lint would not catch it.
+ ///
+ /// List of some examples that can not be caught:
+ /// - binary operation of non-primitive types
+ /// - closure usage
+ /// - some `break` relative operations
+ /// - struct pattern binding
+ ///
+ /// Also, when you recurse the function name with path segments, it is not possible to detect.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn f(a: usize, b: usize) -> usize {
+ /// if a == 0 {
+ /// 1
+ /// } else {
+ /// f(a - 1, b + 1)
+ /// }
+ /// }
+ /// # fn main() {
+ /// # print!("{}", f(1, 1));
+ /// # }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// fn f(a: usize) -> usize {
+ /// if a == 0 {
+ /// 1
+ /// } else {
+ /// f(a - 1)
+ /// }
+ /// }
+ /// # fn main() {
+ /// # print!("{}", f(1));
+ /// # }
+ /// ```
++ #[clippy::version = "1.61.0"]
+ pub ONLY_USED_IN_RECURSION,
+ nursery,
+ "arguments that is only used in recursion can be removed"
+}
+declare_lint_pass!(OnlyUsedInRecursion => [ONLY_USED_IN_RECURSION]);
+
+impl<'tcx> LateLintPass<'tcx> for OnlyUsedInRecursion {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ kind: FnKind<'tcx>,
+ decl: &'tcx rustc_hir::FnDecl<'tcx>,
+ body: &'tcx Body<'tcx>,
+ _: Span,
+ id: HirId,
+ ) {
+ if is_lint_allowed(cx, ONLY_USED_IN_RECURSION, id) {
+ return;
+ }
+ if let FnKind::ItemFn(ident, ..) | FnKind::Method(ident, ..) = kind {
+ let def_id = id.owner.to_def_id();
+ let data = cx.tcx.def_path(def_id).data;
+
+ if data.len() > 1 {
+ match data.get(data.len() - 2) {
+ Some(DisambiguatedDefPathData {
+ data: DefPathData::Impl,
+ disambiguator,
+ }) if *disambiguator != 0 => return,
+ _ => {},
+ }
+ }
+
+ let has_self = !matches!(decl.implicit_self, ImplicitSelfKind::None);
+
+ let ty_res = cx.typeck_results();
+ let param_span = body
+ .params
+ .iter()
+ .flat_map(|param| {
+ let mut v = Vec::new();
+ param.pat.each_binding(|_, hir_id, span, ident| {
+ v.push((hir_id, span, ident));
+ });
+ v
+ })
+ .skip(if has_self { 1 } else { 0 })
+ .filter(|(_, _, ident)| !ident.name.as_str().starts_with('_'))
+ .collect_vec();
+
+ let params = body.params.iter().map(|param| param.pat).collect();
+
+ let mut visitor = SideEffectVisit {
+ graph: FxHashMap::default(),
+ has_side_effect: FxHashSet::default(),
+ ret_vars: Vec::new(),
+ contains_side_effect: false,
+ break_vars: FxHashMap::default(),
+ params,
+ fn_ident: ident,
+ fn_def_id: def_id,
+ is_method: matches!(kind, FnKind::Method(..)),
+ has_self,
+ ty_res,
+ tcx: cx.tcx,
+ visited_exprs: FxHashSet::default(),
+ };
+
+ visitor.visit_expr(&body.value);
+ let vars = std::mem::take(&mut visitor.ret_vars);
+ // this would set the return variables to side effect
+ visitor.add_side_effect(vars);
+
+ let mut queue = visitor.has_side_effect.iter().copied().collect::<VecDeque<_>>();
+
+ // a simple BFS to check all the variables that have side effect
+ while let Some(id) = queue.pop_front() {
+ if let Some(next) = visitor.graph.get(&id) {
+ for i in next {
+ if !visitor.has_side_effect.contains(i) {
+ visitor.has_side_effect.insert(*i);
+ queue.push_back(*i);
+ }
+ }
+ }
+ }
+
+ for (id, span, ident) in param_span {
+ // if the variable is not used in recursion, it would be marked as unused
+ if !visitor.has_side_effect.contains(&id) {
+ let mut queue = VecDeque::new();
+ let mut visited = FxHashSet::default();
+
+ queue.push_back(id);
+
+ // a simple BFS to check the graph can reach to itself
+ // if it can't, it means the variable is never used in recursion
+ while let Some(id) = queue.pop_front() {
+ if let Some(next) = visitor.graph.get(&id) {
+ for i in next {
+ if !visited.contains(i) {
+ visited.insert(id);
+ queue.push_back(*i);
+ }
+ }
+ }
+ }
+
+ if visited.contains(&id) {
+ span_lint_and_sugg(
+ cx,
+ ONLY_USED_IN_RECURSION,
+ span,
+ "parameter is only used in recursion",
+ "if this is intentional, prefix with an underscore",
+ format!("_{}", ident.name.as_str()),
+ Applicability::MaybeIncorrect,
+ );
+ }
+ }
+ }
+ }
+ }
+}
+
+pub fn is_primitive(ty: Ty<'_>) -> bool {
+ let ty = ty.peel_refs();
+ ty.is_primitive() || ty.is_str()
+}
+
+pub fn is_array(ty: Ty<'_>) -> bool {
+ let ty = ty.peel_refs();
+ ty.is_array() || ty.is_array_slice()
+}
+
+/// This builds the graph of side effect.
+/// The edge `a -> b` means if `a` has side effect, `b` will have side effect.
+///
+/// There are some example in following code:
+/// ```rust, ignore
+/// let b = 1;
+/// let a = b; // a -> b
+/// let (c, d) = (a, b); // c -> b, d -> b
+///
+/// let e = if a == 0 { // e -> a
+/// c // e -> c
+/// } else {
+/// d // e -> d
+/// };
+/// ```
+pub struct SideEffectVisit<'tcx> {
+ graph: FxHashMap<HirId, FxHashSet<HirId>>,
+ has_side_effect: FxHashSet<HirId>,
+ // bool for if the variable was dereferenced from mutable reference
+ ret_vars: Vec<(HirId, bool)>,
+ contains_side_effect: bool,
+ // break label
+ break_vars: FxHashMap<Ident, Vec<(HirId, bool)>>,
+ params: Vec<&'tcx Pat<'tcx>>,
+ fn_ident: Ident,
+ fn_def_id: DefId,
+ is_method: bool,
+ has_self: bool,
+ ty_res: &'tcx TypeckResults<'tcx>,
+ tcx: TyCtxt<'tcx>,
+ visited_exprs: FxHashSet<HirId>,
+}
+
+impl<'tcx> Visitor<'tcx> for SideEffectVisit<'tcx> {
+ fn visit_stmt(&mut self, s: &'tcx Stmt<'tcx>) {
+ match s.kind {
+ StmtKind::Local(Local {
+ pat, init: Some(init), ..
+ }) => {
+ self.visit_pat_expr(pat, init, false);
+ },
+ StmtKind::Item(_) | StmtKind::Expr(_) | StmtKind::Semi(_) => {
+ walk_stmt(self, s);
+ },
+ StmtKind::Local(_) => {},
+ }
+ self.ret_vars.clear();
+ }
+
+ fn visit_expr(&mut self, ex: &'tcx Expr<'tcx>) {
+ if !self.visited_exprs.insert(ex.hir_id) {
+ return;
+ }
+ match ex.kind {
+ ExprKind::Array(exprs) | ExprKind::Tup(exprs) => {
+ self.ret_vars = exprs
+ .iter()
+ .flat_map(|expr| {
+ self.visit_expr(expr);
+ std::mem::take(&mut self.ret_vars)
+ })
+ .collect();
+ },
+ ExprKind::Call(callee, args) => self.visit_fn(callee, args),
+ ExprKind::MethodCall(path, args, _) => self.visit_method_call(path, args),
+ ExprKind::Binary(_, lhs, rhs) => {
+ self.visit_bin_op(lhs, rhs);
+ },
+ ExprKind::Unary(op, expr) => self.visit_un_op(op, expr),
+ ExprKind::Let(Let { pat, init, .. }) => self.visit_pat_expr(pat, init, false),
+ ExprKind::If(bind, then_expr, else_expr) => {
+ self.visit_if(bind, then_expr, else_expr);
+ },
+ ExprKind::Match(expr, arms, _) => self.visit_match(expr, arms),
+ // since analysing the closure is not easy, just set all variables in it to side-effect
+ ExprKind::Closure { body, .. } => {
+ let body = self.tcx.hir().body(body);
+ self.visit_body(body);
+ let vars = std::mem::take(&mut self.ret_vars);
+ self.add_side_effect(vars);
+ },
+ ExprKind::Loop(block, label, _, _) | ExprKind::Block(block, label) => {
+ self.visit_block_label(block, label);
+ },
+ ExprKind::Assign(bind, expr, _) => {
+ self.visit_assign(bind, expr);
+ },
+ ExprKind::AssignOp(_, bind, expr) => {
+ self.visit_assign(bind, expr);
+ self.visit_bin_op(bind, expr);
+ },
+ ExprKind::Field(expr, _) => {
+ self.visit_expr(expr);
+ if matches!(self.ty_res.expr_ty(expr).kind(), ty::Ref(_, _, Mutability::Mut)) {
+ self.ret_vars.iter_mut().for_each(|(_, b)| *b = true);
+ }
+ },
+ ExprKind::Index(expr, index) => {
+ self.visit_expr(expr);
+ let mut vars = std::mem::take(&mut self.ret_vars);
+ self.visit_expr(index);
+ self.ret_vars.append(&mut vars);
+
+ if !is_array(self.ty_res.expr_ty(expr)) {
+ self.add_side_effect(self.ret_vars.clone());
+ } else if matches!(self.ty_res.expr_ty(expr).kind(), ty::Ref(_, _, Mutability::Mut)) {
+ self.ret_vars.iter_mut().for_each(|(_, b)| *b = true);
+ }
+ },
+ ExprKind::Break(dest, Some(expr)) => {
+ self.visit_expr(expr);
+ if let Some(label) = dest.label {
+ self.break_vars
+ .entry(label.ident)
+ .or_insert(Vec::new())
+ .append(&mut self.ret_vars);
+ }
+ self.contains_side_effect = true;
+ },
+ ExprKind::Ret(Some(expr)) => {
+ self.visit_expr(expr);
+ let vars = std::mem::take(&mut self.ret_vars);
+ self.add_side_effect(vars);
+ self.contains_side_effect = true;
+ },
+ ExprKind::Break(_, None) | ExprKind::Continue(_) | ExprKind::Ret(None) => {
+ self.contains_side_effect = true;
+ },
+ ExprKind::Struct(_, exprs, expr) => {
+ let mut ret_vars = exprs
+ .iter()
+ .flat_map(|field| {
+ self.visit_expr(field.expr);
+ std::mem::take(&mut self.ret_vars)
+ })
+ .collect();
+
+ walk_list!(self, visit_expr, expr);
+ self.ret_vars.append(&mut ret_vars);
+ },
+ _ => walk_expr(self, ex),
+ }
+ }
+
+ fn visit_path(&mut self, path: &'tcx Path<'tcx>, _id: HirId) {
+ if let Res::Local(id) = path.res {
+ self.ret_vars.push((id, false));
+ }
+ }
+}
+
+impl<'tcx> SideEffectVisit<'tcx> {
+ fn visit_assign(&mut self, lhs: &'tcx Expr<'tcx>, rhs: &'tcx Expr<'tcx>) {
+ // Just support array and tuple unwrapping for now.
+ //
+ // ex) `(a, b) = (c, d);`
+ // The graph would look like this:
+ // a -> c
+ // b -> d
+ //
+ // This would minimize the connection of the side-effect graph.
+ match (&lhs.kind, &rhs.kind) {
+ (ExprKind::Array(lhs), ExprKind::Array(rhs)) | (ExprKind::Tup(lhs), ExprKind::Tup(rhs)) => {
+ // if not, it is a compile error
+ debug_assert!(lhs.len() == rhs.len());
+ izip!(*lhs, *rhs).for_each(|(lhs, rhs)| self.visit_assign(lhs, rhs));
+ },
+ // in other assigns, we have to connect all each other
+ // because they can be connected somehow
+ _ => {
+ self.visit_expr(lhs);
+ let lhs_vars = std::mem::take(&mut self.ret_vars);
+ self.visit_expr(rhs);
+ let rhs_vars = std::mem::take(&mut self.ret_vars);
+ self.connect_assign(&lhs_vars, &rhs_vars, false);
+ },
+ }
+ }
+
+ fn visit_block_label(&mut self, block: &'tcx Block<'tcx>, label: Option<Label>) {
+ self.visit_block(block);
+ let _ = label.and_then(|label| {
+ self.break_vars
+ .remove(&label.ident)
+ .map(|mut break_vars| self.ret_vars.append(&mut break_vars))
+ });
+ }
+
+ fn visit_bin_op(&mut self, lhs: &'tcx Expr<'tcx>, rhs: &'tcx Expr<'tcx>) {
+ self.visit_expr(lhs);
+ let mut ret_vars = std::mem::take(&mut self.ret_vars);
+ self.visit_expr(rhs);
+ self.ret_vars.append(&mut ret_vars);
+
+ // the binary operation between non primitive values are overloaded operators
+ // so they can have side-effects
+ if !is_primitive(self.ty_res.expr_ty(lhs)) || !is_primitive(self.ty_res.expr_ty(rhs)) {
+ self.ret_vars.iter().for_each(|id| {
+ self.has_side_effect.insert(id.0);
+ });
+ self.contains_side_effect = true;
+ }
+ }
+
+ fn visit_un_op(&mut self, op: UnOp, expr: &'tcx Expr<'tcx>) {
+ self.visit_expr(expr);
+ let ty = self.ty_res.expr_ty(expr);
+ // dereferencing a reference has no side-effect
+ if !is_primitive(ty) && !matches!((op, ty.kind()), (UnOp::Deref, ty::Ref(..))) {
+ self.add_side_effect(self.ret_vars.clone());
+ }
+
+ if matches!((op, ty.kind()), (UnOp::Deref, ty::Ref(_, _, Mutability::Mut))) {
+ self.ret_vars.iter_mut().for_each(|(_, b)| *b = true);
+ }
+ }
+
+ fn visit_pat_expr(&mut self, pat: &'tcx Pat<'tcx>, expr: &'tcx Expr<'tcx>, connect_self: bool) {
+ match (&pat.kind, &expr.kind) {
+ (PatKind::Tuple(pats, _), ExprKind::Tup(exprs)) => {
+ self.ret_vars = izip!(*pats, *exprs)
+ .flat_map(|(pat, expr)| {
+ self.visit_pat_expr(pat, expr, connect_self);
+ std::mem::take(&mut self.ret_vars)
+ })
+ .collect();
+ },
+ (PatKind::Slice(front_exprs, _, back_exprs), ExprKind::Array(exprs)) => {
+ let mut vars = izip!(*front_exprs, *exprs)
+ .flat_map(|(pat, expr)| {
+ self.visit_pat_expr(pat, expr, connect_self);
+ std::mem::take(&mut self.ret_vars)
+ })
+ .collect();
+ self.ret_vars = izip!(back_exprs.iter().rev(), exprs.iter().rev())
+ .flat_map(|(pat, expr)| {
+ self.visit_pat_expr(pat, expr, connect_self);
+ std::mem::take(&mut self.ret_vars)
+ })
+ .collect();
+ self.ret_vars.append(&mut vars);
+ },
+ _ => {
+ let mut lhs_vars = Vec::new();
+ pat.each_binding(|_, id, _, _| lhs_vars.push((id, false)));
+ self.visit_expr(expr);
+ let rhs_vars = std::mem::take(&mut self.ret_vars);
+ self.connect_assign(&lhs_vars, &rhs_vars, connect_self);
+ self.ret_vars = rhs_vars;
+ },
+ }
+ }
+
+ fn visit_fn(&mut self, callee: &'tcx Expr<'tcx>, args: &'tcx [Expr<'tcx>]) {
+ self.visit_expr(callee);
+ let mut ret_vars = std::mem::take(&mut self.ret_vars);
+ self.add_side_effect(ret_vars.clone());
+
+ let mut is_recursive = false;
+
+ if_chain! {
+ if !self.has_self;
+ if let ExprKind::Path(QPath::Resolved(_, path)) = callee.kind;
+ if let Res::Def(DefKind::Fn, def_id) = path.res;
+ if self.fn_def_id == def_id;
+ then {
+ is_recursive = true;
+ }
+ }
+
+ if_chain! {
+ if !self.has_self && self.is_method;
+ if let ExprKind::Path(QPath::TypeRelative(ty, segment)) = callee.kind;
+ if segment.ident == self.fn_ident;
+ if let TyKind::Path(QPath::Resolved(_, path)) = ty.kind;
+ if let Res::SelfTy{ .. } = path.res;
+ then {
+ is_recursive = true;
+ }
+ }
+
+ if is_recursive {
+ izip!(self.params.clone(), args).for_each(|(pat, expr)| {
+ self.visit_pat_expr(pat, expr, true);
+ self.ret_vars.clear();
+ });
+ } else {
+ // This would set arguments used in closure that does not have side-effect.
+ // Closure itself can be detected whether there is a side-effect, but the
+ // value of variable that is holding closure can change.
+ // So, we just check the variables.
+ self.ret_vars = args
+ .iter()
+ .flat_map(|expr| {
+ self.visit_expr(expr);
+ std::mem::take(&mut self.ret_vars)
+ })
+ .collect_vec()
+ .into_iter()
+ .map(|id| {
+ self.has_side_effect.insert(id.0);
+ id
+ })
+ .collect();
+ self.contains_side_effect = true;
+ }
+
+ self.ret_vars.append(&mut ret_vars);
+ }
+
+ fn visit_method_call(&mut self, path: &'tcx PathSegment<'tcx>, args: &'tcx [Expr<'tcx>]) {
+ if_chain! {
+ if self.is_method;
+ if path.ident == self.fn_ident;
+ if let ExprKind::Path(QPath::Resolved(_, path)) = args.first().unwrap().kind;
+ if let Res::Local(..) = path.res;
+ let ident = path.segments.last().unwrap().ident;
+ if ident.name == kw::SelfLower;
+ then {
+ izip!(self.params.clone(), args.iter())
+ .for_each(|(pat, expr)| {
+ self.visit_pat_expr(pat, expr, true);
+ self.ret_vars.clear();
+ });
+ } else {
+ self.ret_vars = args
+ .iter()
+ .flat_map(|expr| {
+ self.visit_expr(expr);
+ std::mem::take(&mut self.ret_vars)
+ })
+ .collect_vec()
+ .into_iter()
+ .map(|a| {
+ self.has_side_effect.insert(a.0);
+ a
+ })
+ .collect();
+ self.contains_side_effect = true;
+ }
+ }
+ }
+
+ fn visit_if(&mut self, bind: &'tcx Expr<'tcx>, then_expr: &'tcx Expr<'tcx>, else_expr: Option<&'tcx Expr<'tcx>>) {
+ let contains_side_effect = self.contains_side_effect;
+ self.contains_side_effect = false;
+ self.visit_expr(bind);
+ let mut vars = std::mem::take(&mut self.ret_vars);
+ self.visit_expr(then_expr);
+ let mut then_vars = std::mem::take(&mut self.ret_vars);
+ walk_list!(self, visit_expr, else_expr);
+ if self.contains_side_effect {
+ self.add_side_effect(vars.clone());
+ }
+ self.contains_side_effect |= contains_side_effect;
+ self.ret_vars.append(&mut vars);
+ self.ret_vars.append(&mut then_vars);
+ }
+
+ fn visit_match(&mut self, expr: &'tcx Expr<'tcx>, arms: &'tcx [Arm<'tcx>]) {
+ self.visit_expr(expr);
+ let mut expr_vars = std::mem::take(&mut self.ret_vars);
+ self.ret_vars = arms
+ .iter()
+ .flat_map(|arm| {
+ let contains_side_effect = self.contains_side_effect;
+ self.contains_side_effect = false;
+ // this would visit `expr` multiple times
+ // but couldn't think of a better way
+ self.visit_pat_expr(arm.pat, expr, false);
+ let mut vars = std::mem::take(&mut self.ret_vars);
+ let _ = arm.guard.as_ref().map(|guard| {
+ self.visit_expr(match guard {
+ Guard::If(expr) | Guard::IfLet(Let { init: expr, .. }) => expr,
+ });
+ vars.append(&mut self.ret_vars);
+ });
+ self.visit_expr(arm.body);
+ if self.contains_side_effect {
+ self.add_side_effect(vars.clone());
+ self.add_side_effect(expr_vars.clone());
+ }
+ self.contains_side_effect |= contains_side_effect;
+ vars.append(&mut self.ret_vars);
+ vars
+ })
+ .collect();
+ self.ret_vars.append(&mut expr_vars);
+ }
+
+ fn connect_assign(&mut self, lhs: &[(HirId, bool)], rhs: &[(HirId, bool)], connect_self: bool) {
+ // if mutable dereference is on assignment it can have side-effect
+ // (this can lead to parameter mutable dereference and change the original value)
+ // too hard to detect whether this value is from parameter, so this would all
+ // check mutable dereference assignment to side effect
+ lhs.iter().filter(|(_, b)| *b).for_each(|(id, _)| {
+ self.has_side_effect.insert(*id);
+ self.contains_side_effect = true;
+ });
+
+ // there is no connection
+ if lhs.is_empty() || rhs.is_empty() {
+ return;
+ }
+
+ // by connected rhs in cycle, the connections would decrease
+ // from `n * m` to `n + m`
+ // where `n` and `m` are length of `lhs` and `rhs`.
+
+ // unwrap is possible since rhs is not empty
+ let rhs_first = rhs.first().unwrap();
+ for (id, _) in lhs.iter() {
+ if connect_self || *id != rhs_first.0 {
+ self.graph
+ .entry(*id)
+ .or_insert_with(FxHashSet::default)
+ .insert(rhs_first.0);
+ }
+ }
+
+ let rhs = rhs.iter();
+ izip!(rhs.clone().cycle().skip(1), rhs).for_each(|(from, to)| {
+ if connect_self || from.0 != to.0 {
+ self.graph.entry(from.0).or_insert_with(FxHashSet::default).insert(to.0);
+ }
+ });
+ }
+
+ fn add_side_effect(&mut self, v: Vec<(HirId, bool)>) {
+ for (id, _) in v {
+ self.has_side_effect.insert(id);
+ self.contains_side_effect = true;
+ }
+ }
+}
--- /dev/null
- /// // Bad
+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
- /// // Better
+ /// fn foo(v: &u32) {}
+ /// ```
+ ///
++ /// Use instead:
+ /// ```rust
- /// // Bad
+ /// 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]);
+ ///
- /// ```rust
- /// #[derive(Clone, Copy)]
- /// struct TooLarge([u8; 2048]);
+ /// fn foo(v: TooLarge) {}
+ /// ```
- /// // Good
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # #[derive(Clone, Copy)]
++ /// # struct TooLarge([u8; 2048]);
+ /// 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
- /// // Bad
+//! Checks for usage of `&Vec[_]` and `&String`.
+
+use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::source::snippet_opt;
+use clippy_utils::ty::expr_sig;
+use clippy_utils::visitors::contains_unsafe_block;
+use clippy_utils::{get_expr_use_or_unification_node, is_lint_allowed, path_def_id, path_to_local, paths};
+use if_chain::if_chain;
+use rustc_errors::{Applicability, MultiSpan};
+use rustc_hir::def_id::DefId;
+use rustc_hir::hir_id::HirIdMap;
+use rustc_hir::intravisit::{walk_expr, Visitor};
+use rustc_hir::{
+ self as hir, AnonConst, BinOpKind, BindingAnnotation, Body, Expr, ExprKind, FnRetTy, FnSig, GenericArg,
+ ImplItemKind, ItemKind, Lifetime, LifetimeName, Mutability, Node, Param, ParamName, PatKind, QPath, TraitFn,
+ TraitItem, TraitItemKind, TyKind, Unsafety,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::nested_filter;
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use rustc_span::sym;
+use rustc_span::symbol::Symbol;
+use std::fmt;
+use std::iter;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint checks for function arguments of type `&String`, `&Vec`,
+ /// `&PathBuf`, and `Cow<_>`. It will also suggest you replace `.clone()` calls
+ /// with the appropriate `.to_owned()`/`to_string()` calls.
+ ///
+ /// ### Why is this bad?
+ /// Requiring the argument to be of the specific size
+ /// makes the function less useful for no benefit; slices in the form of `&[T]`
+ /// or `&str` usually suffice and can be obtained from other types, too.
+ ///
+ /// ### Known problems
+ /// There may be `fn(&Vec)`-typed references pointing to your function.
+ /// If you have them, you will get a compiler error after applying this lint's
+ /// suggestions. You then have the choice to undo your changes or change the
+ /// type of the reference.
+ ///
+ /// Note that if the function is part of your public interface, there may be
+ /// other crates referencing it, of which you may not be aware. Carefully
+ /// deprecate the function before applying the lint suggestions in this case.
+ ///
+ /// ### Example
+ /// ```ignore
- /// // Good
+ /// fn foo(&Vec<u32>) { .. }
++ /// ```
+ ///
- /// ```ignore
- /// // Bad
++ /// Use instead:
++ /// ```ignore
+ /// fn foo(&[u32]) { .. }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub PTR_ARG,
+ style,
+ "fn arguments of the type `&Vec<...>` or `&String`, suggesting to use `&[...]` or `&str` instead, respectively"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint checks for equality comparisons with `ptr::null`
+ ///
+ /// ### Why is this bad?
+ /// It's easier and more readable to use the inherent
+ /// `.is_null()`
+ /// method instead
+ ///
+ /// ### Example
- /// ..
++ /// ```rust,ignore
++ /// use std::ptr;
++ ///
+ /// if x == ptr::null {
- /// // Good
++ /// // ..
+ /// }
++ /// ```
+ ///
- /// ..
++ /// Use instead:
++ /// ```rust,ignore
+ /// if x.is_null() {
- /// // Bad. Undefined behavior
++ /// // ..
+ /// }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub CMP_NULL,
+ style,
+ "comparing a pointer to a null pointer, suggesting to use `.is_null()` instead"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint checks for functions that take immutable references and return
+ /// mutable ones. This will not trigger if no unsafe code exists as there
+ /// are multiple safe functions which will do this transformation
+ ///
+ /// To be on the conservative side, if there's at least one mutable
+ /// reference with the output lifetime, this lint will not trigger.
+ ///
+ /// ### Why is this bad?
+ /// Creating a mutable reference which can be repeatably derived from an
+ /// immutable reference is unsound as it allows creating multiple live
+ /// mutable references to the same object.
+ ///
+ /// This [error](https://github.com/rust-lang/rust/issues/39465) actually
+ /// lead to an interim Rust release 1.15.1.
+ ///
+ /// ### Known problems
+ /// This pattern is used by memory allocators to allow allocating multiple
+ /// objects while returning mutable references to each one. So long as
+ /// different mutable references are returned each time such a function may
+ /// be safe.
+ ///
+ /// ### Example
+ /// ```ignore
+ /// fn foo(&Foo) -> &mut Bar { .. }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MUT_FROM_REF,
+ correctness,
+ "fns that create mutable refs from immutable ref args"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint checks for invalid usages of `ptr::null`.
+ ///
+ /// ### Why is this bad?
+ /// This causes undefined behavior.
+ ///
+ /// ### Example
+ /// ```ignore
- /// // Good
++ /// // Undefined behavior
+ /// unsafe { std::slice::from_raw_parts(ptr::null(), 0); }
+ /// ```
+ ///
++ /// Use instead:
+ /// ```ignore
+ /// unsafe { std::slice::from_raw_parts(NonNull::dangling().as_ptr(), 0); }
+ /// ```
+ #[clippy::version = "1.53.0"]
+ pub INVALID_NULL_PTR_USAGE,
+ correctness,
+ "invalid usage of a null pointer, suggesting `NonNull::dangling()` instead"
+}
+
+declare_lint_pass!(Ptr => [PTR_ARG, CMP_NULL, MUT_FROM_REF, INVALID_NULL_PTR_USAGE]);
+
+impl<'tcx> LateLintPass<'tcx> for Ptr {
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'_>) {
+ if let TraitItemKind::Fn(sig, trait_method) = &item.kind {
+ if matches!(trait_method, TraitFn::Provided(_)) {
+ // Handled by check body.
+ return;
+ }
+
+ check_mut_from_ref(cx, sig, None);
+ for arg in check_fn_args(
+ cx,
+ cx.tcx.fn_sig(item.def_id).skip_binder().inputs(),
+ sig.decl.inputs,
+ &[],
+ )
+ .filter(|arg| arg.mutability() == Mutability::Not)
+ {
+ span_lint_and_sugg(
+ cx,
+ PTR_ARG,
+ arg.span,
+ &arg.build_msg(),
+ "change this to",
+ format!("{}{}", arg.ref_prefix, arg.deref_ty.display(cx)),
+ Applicability::Unspecified,
+ );
+ }
+ }
+ }
+
+ fn check_body(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'_>) {
+ let hir = cx.tcx.hir();
+ let mut parents = hir.parent_iter(body.value.hir_id);
+ let (item_id, sig, is_trait_item) = match parents.next() {
+ Some((_, Node::Item(i))) => {
+ if let ItemKind::Fn(sig, ..) = &i.kind {
+ (i.def_id, sig, false)
+ } else {
+ return;
+ }
+ },
+ Some((_, Node::ImplItem(i))) => {
+ if !matches!(parents.next(),
+ Some((_, Node::Item(i))) if matches!(&i.kind, ItemKind::Impl(i) if i.of_trait.is_none())
+ ) {
+ return;
+ }
+ if let ImplItemKind::Fn(sig, _) = &i.kind {
+ (i.def_id, sig, false)
+ } else {
+ return;
+ }
+ },
+ Some((_, Node::TraitItem(i))) => {
+ if let TraitItemKind::Fn(sig, _) = &i.kind {
+ (i.def_id, sig, true)
+ } else {
+ return;
+ }
+ },
+ _ => return,
+ };
+
+ check_mut_from_ref(cx, sig, Some(body));
+ let decl = sig.decl;
+ let sig = cx.tcx.fn_sig(item_id).skip_binder();
+ let lint_args: Vec<_> = check_fn_args(cx, sig.inputs(), decl.inputs, body.params)
+ .filter(|arg| !is_trait_item || arg.mutability() == Mutability::Not)
+ .collect();
+ let results = check_ptr_arg_usage(cx, body, &lint_args);
+
+ for (result, args) in results.iter().zip(lint_args.iter()).filter(|(r, _)| !r.skip) {
+ span_lint_and_then(cx, PTR_ARG, args.span, &args.build_msg(), |diag| {
+ diag.multipart_suggestion(
+ "change this to",
+ iter::once((args.span, format!("{}{}", args.ref_prefix, args.deref_ty.display(cx))))
+ .chain(result.replacements.iter().map(|r| {
+ (
+ r.expr_span,
+ format!("{}{}", snippet_opt(cx, r.self_span).unwrap(), r.replacement),
+ )
+ }))
+ .collect(),
+ Applicability::Unspecified,
+ );
+ });
+ }
+ }
+
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if let ExprKind::Binary(ref op, l, r) = expr.kind {
+ if (op.node == BinOpKind::Eq || op.node == BinOpKind::Ne) && (is_null_path(cx, l) || is_null_path(cx, r)) {
+ span_lint(
+ cx,
+ CMP_NULL,
+ expr.span,
+ "comparing with null is better expressed by the `.is_null()` method",
+ );
+ }
+ } else {
+ check_invalid_ptr_usage(cx, expr);
+ }
+ }
+}
+
+fn check_invalid_ptr_usage<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ // (fn_path, arg_indices) - `arg_indices` are the `arg` positions where null would cause U.B.
+ const INVALID_NULL_PTR_USAGE_TABLE: [(&[&str], &[usize]); 16] = [
+ (&paths::SLICE_FROM_RAW_PARTS, &[0]),
+ (&paths::SLICE_FROM_RAW_PARTS_MUT, &[0]),
+ (&paths::PTR_COPY, &[0, 1]),
+ (&paths::PTR_COPY_NONOVERLAPPING, &[0, 1]),
+ (&paths::PTR_READ, &[0]),
+ (&paths::PTR_READ_UNALIGNED, &[0]),
+ (&paths::PTR_READ_VOLATILE, &[0]),
+ (&paths::PTR_REPLACE, &[0]),
+ (&paths::PTR_SLICE_FROM_RAW_PARTS, &[0]),
+ (&paths::PTR_SLICE_FROM_RAW_PARTS_MUT, &[0]),
+ (&paths::PTR_SWAP, &[0, 1]),
+ (&paths::PTR_SWAP_NONOVERLAPPING, &[0, 1]),
+ (&paths::PTR_WRITE, &[0]),
+ (&paths::PTR_WRITE_UNALIGNED, &[0]),
+ (&paths::PTR_WRITE_VOLATILE, &[0]),
+ (&paths::PTR_WRITE_BYTES, &[0]),
+ ];
+
+ 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();
+ let fun_def_path = cx.get_def_path(fun_def_id).into_iter().map(Symbol::to_ident_string).collect::<Vec<_>>();
+ if let Some(&(_, arg_indices)) = INVALID_NULL_PTR_USAGE_TABLE
+ .iter()
+ .find(|&&(fn_path, _)| fn_path == fun_def_path);
+ then {
+ for &arg_idx in arg_indices {
+ if let Some(arg) = args.get(arg_idx).filter(|arg| is_null_path(cx, arg)) {
+ span_lint_and_sugg(
+ cx,
+ INVALID_NULL_PTR_USAGE,
+ arg.span,
+ "pointer must be non-null",
+ "change this to",
+ "core::ptr::NonNull::dangling().as_ptr()".to_string(),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ }
+ }
+}
+
+#[derive(Default)]
+struct PtrArgResult {
+ skip: bool,
+ replacements: Vec<PtrArgReplacement>,
+}
+
+struct PtrArgReplacement {
+ expr_span: Span,
+ self_span: Span,
+ replacement: &'static str,
+}
+
+struct PtrArg<'tcx> {
+ idx: usize,
+ span: Span,
+ ty_did: DefId,
+ ty_name: Symbol,
+ method_renames: &'static [(&'static str, &'static str)],
+ ref_prefix: RefPrefix,
+ deref_ty: DerefTy<'tcx>,
+}
+impl PtrArg<'_> {
+ fn build_msg(&self) -> String {
+ format!(
+ "writing `&{}{}` instead of `&{}{}` involves a new object where a slice will do",
+ self.ref_prefix.mutability.prefix_str(),
+ self.ty_name,
+ self.ref_prefix.mutability.prefix_str(),
+ self.deref_ty.argless_str(),
+ )
+ }
+
+ fn mutability(&self) -> Mutability {
+ self.ref_prefix.mutability
+ }
+}
+
+struct RefPrefix {
+ lt: LifetimeName,
+ mutability: Mutability,
+}
+impl fmt::Display for RefPrefix {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ use fmt::Write;
+ f.write_char('&')?;
+ match self.lt {
+ LifetimeName::Param(_, ParamName::Plain(name)) => {
+ name.fmt(f)?;
+ f.write_char(' ')?;
+ },
+ LifetimeName::Underscore => f.write_str("'_ ")?,
+ LifetimeName::Static => f.write_str("'static ")?,
+ _ => (),
+ }
+ f.write_str(self.mutability.prefix_str())
+ }
+}
+
+struct DerefTyDisplay<'a, 'tcx>(&'a LateContext<'tcx>, &'a DerefTy<'tcx>);
+impl fmt::Display for DerefTyDisplay<'_, '_> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ use std::fmt::Write;
+ match self.1 {
+ DerefTy::Str => f.write_str("str"),
+ DerefTy::Path => f.write_str("Path"),
+ DerefTy::Slice(hir_ty, ty) => {
+ f.write_char('[')?;
+ match hir_ty.and_then(|s| snippet_opt(self.0, s)) {
+ Some(s) => f.write_str(&s)?,
+ None => ty.fmt(f)?,
+ }
+ f.write_char(']')
+ },
+ }
+ }
+}
+
+enum DerefTy<'tcx> {
+ Str,
+ Path,
+ Slice(Option<Span>, Ty<'tcx>),
+}
+impl<'tcx> DerefTy<'tcx> {
+ fn argless_str(&self) -> &'static str {
+ match *self {
+ Self::Str => "str",
+ Self::Path => "Path",
+ Self::Slice(..) => "[_]",
+ }
+ }
+
+ fn display<'a>(&'a self, cx: &'a LateContext<'tcx>) -> DerefTyDisplay<'a, 'tcx> {
+ DerefTyDisplay(cx, self)
+ }
+}
+
+fn check_fn_args<'cx, 'tcx: 'cx>(
+ cx: &'cx LateContext<'tcx>,
+ tys: &'tcx [Ty<'tcx>],
+ hir_tys: &'tcx [hir::Ty<'tcx>],
+ params: &'tcx [Param<'tcx>],
+) -> impl Iterator<Item = PtrArg<'tcx>> + 'cx {
+ tys.iter()
+ .zip(hir_tys.iter())
+ .enumerate()
+ .filter_map(|(i, (ty, hir_ty))| {
+ if_chain! {
+ if let ty::Ref(_, ty, mutability) = *ty.kind();
+ if let ty::Adt(adt, substs) = *ty.kind();
+
+ if let TyKind::Rptr(lt, ref ty) = hir_ty.kind;
+ if let TyKind::Path(QPath::Resolved(None, path)) = ty.ty.kind;
+
+ // Check that the name as typed matches the actual name of the type.
+ // e.g. `fn foo(_: &Foo)` shouldn't trigger the lint when `Foo` is an alias for `Vec`
+ if let [.., name] = path.segments;
+ if cx.tcx.item_name(adt.did()) == name.ident.name;
+
+ if !is_lint_allowed(cx, PTR_ARG, hir_ty.hir_id);
+ if params.get(i).map_or(true, |p| !is_lint_allowed(cx, PTR_ARG, p.hir_id));
+
+ then {
+ let (method_renames, deref_ty) = match cx.tcx.get_diagnostic_name(adt.did()) {
+ Some(sym::Vec) => (
+ [("clone", ".to_owned()")].as_slice(),
+ DerefTy::Slice(
+ name.args
+ .and_then(|args| args.args.first())
+ .and_then(|arg| if let GenericArg::Type(ty) = arg {
+ Some(ty.span)
+ } else {
+ None
+ }),
+ substs.type_at(0),
+ ),
+ ),
+ Some(sym::String) => (
+ [("clone", ".to_owned()"), ("as_str", "")].as_slice(),
+ DerefTy::Str,
+ ),
+ Some(sym::PathBuf) => (
+ [("clone", ".to_path_buf()"), ("as_path", "")].as_slice(),
+ DerefTy::Path,
+ ),
+ Some(sym::Cow) if mutability == Mutability::Not => {
+ let ty_name = name.args
+ .and_then(|args| {
+ args.args.iter().find_map(|a| match a {
+ GenericArg::Type(x) => Some(x),
+ _ => None,
+ })
+ })
+ .and_then(|arg| snippet_opt(cx, arg.span))
+ .unwrap_or_else(|| substs.type_at(1).to_string());
+ span_lint_and_sugg(
+ cx,
+ PTR_ARG,
+ hir_ty.span,
+ "using a reference to `Cow` is not recommended",
+ "change this to",
+ format!("&{}{}", mutability.prefix_str(), ty_name),
+ Applicability::Unspecified,
+ );
+ return None;
+ },
+ _ => return None,
+ };
+ return Some(PtrArg {
+ idx: i,
+ span: hir_ty.span,
+ ty_did: adt.did(),
+ ty_name: name.ident.name,
+ method_renames,
+ ref_prefix: RefPrefix {
+ lt: lt.name,
+ mutability,
+ },
+ deref_ty,
+ });
+ }
+ }
+ None
+ })
+}
+
+fn check_mut_from_ref<'tcx>(cx: &LateContext<'tcx>, sig: &FnSig<'_>, body: Option<&'tcx Body<'_>>) {
+ if let FnRetTy::Return(ty) = sig.decl.output
+ && let Some((out, Mutability::Mut, _)) = get_rptr_lm(ty)
+ {
+ let args: Option<Vec<_>> = sig
+ .decl
+ .inputs
+ .iter()
+ .filter_map(get_rptr_lm)
+ .filter(|&(lt, _, _)| lt.name == out.name)
+ .map(|(_, mutability, span)| (mutability == Mutability::Not).then(|| span))
+ .collect();
+ if let Some(args) = args
+ && !args.is_empty()
+ && body.map_or(true, |body| {
+ sig.header.unsafety == Unsafety::Unsafe || contains_unsafe_block(cx, &body.value)
+ })
+ {
+ span_lint_and_then(
+ cx,
+ MUT_FROM_REF,
+ ty.span,
+ "mutable borrow from immutable input(s)",
+ |diag| {
+ let ms = MultiSpan::from_spans(args);
+ diag.span_note(ms, "immutable borrow here");
+ },
+ );
+ }
+ }
+}
+
+#[expect(clippy::too_many_lines)]
+fn check_ptr_arg_usage<'tcx>(cx: &LateContext<'tcx>, body: &'tcx Body<'_>, args: &[PtrArg<'tcx>]) -> Vec<PtrArgResult> {
+ struct V<'cx, 'tcx> {
+ cx: &'cx LateContext<'tcx>,
+ /// Map from a local id to which argument it came from (index into `Self::args` and
+ /// `Self::results`)
+ bindings: HirIdMap<usize>,
+ /// The arguments being checked.
+ args: &'cx [PtrArg<'tcx>],
+ /// The results for each argument (len should match args.len)
+ results: Vec<PtrArgResult>,
+ /// The number of arguments which can't be linted. Used to return early.
+ skip_count: usize,
+ }
+ impl<'tcx> Visitor<'tcx> for V<'_, 'tcx> {
+ type NestedFilter = nested_filter::OnlyBodies;
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+
+ fn visit_anon_const(&mut self, _: &'tcx AnonConst) {}
+
+ fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
+ if self.skip_count == self.args.len() {
+ return;
+ }
+
+ // Check if this is local we care about
+ let args_idx = match path_to_local(e).and_then(|id| self.bindings.get(&id)) {
+ Some(&i) => i,
+ None => return walk_expr(self, e),
+ };
+ let args = &self.args[args_idx];
+ let result = &mut self.results[args_idx];
+
+ // Helper function to handle early returns.
+ let mut set_skip_flag = || {
+ if !result.skip {
+ self.skip_count += 1;
+ }
+ result.skip = true;
+ };
+
+ match get_expr_use_or_unification_node(self.cx.tcx, e) {
+ Some((Node::Stmt(_), _)) => (),
+ Some((Node::Local(l), _)) => {
+ // Only trace simple bindings. e.g `let x = y;`
+ if let PatKind::Binding(BindingAnnotation::Unannotated, id, _, None) = l.pat.kind {
+ self.bindings.insert(id, args_idx);
+ } else {
+ set_skip_flag();
+ }
+ },
+ Some((Node::Expr(e), child_id)) => match e.kind {
+ ExprKind::Call(f, expr_args) => {
+ let i = expr_args.iter().position(|arg| arg.hir_id == child_id).unwrap_or(0);
+ if expr_sig(self.cx, f)
+ .map(|sig| sig.input(i).skip_binder().peel_refs())
+ .map_or(true, |ty| match *ty.kind() {
+ ty::Param(_) => true,
+ ty::Adt(def, _) => def.did() == args.ty_did,
+ _ => false,
+ })
+ {
+ // Passed to a function taking the non-dereferenced type.
+ set_skip_flag();
+ }
+ },
+ ExprKind::MethodCall(name, expr_args @ [self_arg, ..], _) => {
+ let i = expr_args.iter().position(|arg| arg.hir_id == child_id).unwrap_or(0);
+ if i == 0 {
+ // Check if the method can be renamed.
+ let name = name.ident.as_str();
+ if let Some((_, replacement)) = args.method_renames.iter().find(|&&(x, _)| x == name) {
+ result.replacements.push(PtrArgReplacement {
+ expr_span: e.span,
+ self_span: self_arg.span,
+ replacement,
+ });
+ return;
+ }
+ }
+
+ let id = if let Some(x) = self.cx.typeck_results().type_dependent_def_id(e.hir_id) {
+ x
+ } else {
+ set_skip_flag();
+ return;
+ };
+
+ match *self.cx.tcx.fn_sig(id).skip_binder().inputs()[i].peel_refs().kind() {
+ ty::Param(_) => {
+ set_skip_flag();
+ },
+ // If the types match check for methods which exist on both types. e.g. `Vec::len` and
+ // `slice::len`
+ ty::Adt(def, _) if def.did() == args.ty_did => {
+ set_skip_flag();
+ },
+ _ => (),
+ }
+ },
+ // Indexing is fine for currently supported types.
+ ExprKind::Index(e, _) if e.hir_id == child_id => (),
+ _ => set_skip_flag(),
+ },
+ _ => set_skip_flag(),
+ }
+ }
+ }
+
+ let mut skip_count = 0;
+ let mut results = args.iter().map(|_| PtrArgResult::default()).collect::<Vec<_>>();
+ let mut v = V {
+ cx,
+ bindings: args
+ .iter()
+ .enumerate()
+ .filter_map(|(i, arg)| {
+ let param = &body.params[arg.idx];
+ match param.pat.kind {
+ PatKind::Binding(BindingAnnotation::Unannotated, id, _, None)
+ if !is_lint_allowed(cx, PTR_ARG, param.hir_id) =>
+ {
+ Some((id, i))
+ },
+ _ => {
+ skip_count += 1;
+ results[i].skip = true;
+ None
+ },
+ }
+ })
+ .collect(),
+ args,
+ results,
+ skip_count,
+ };
+ v.visit_expr(&body.value);
+ v.results
+}
+
+fn get_rptr_lm<'tcx>(ty: &'tcx hir::Ty<'tcx>) -> Option<(&'tcx Lifetime, Mutability, Span)> {
+ if let TyKind::Rptr(ref lt, ref m) = ty.kind {
+ Some((lt, m.mutbl, ty.span))
+ } else {
+ None
+ }
+}
+
+fn is_null_path(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ if let ExprKind::Call(pathexp, []) = expr.kind {
+ path_def_id(cx, pathexp).map_or(false, |id| {
+ matches!(cx.tcx.get_diagnostic_name(id), Some(sym::ptr_null | sym::ptr_null_mut))
+ })
+ } else {
+ false
+ }
+}
--- /dev/null
- /// x.iter().zip(0..x.len());
+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];
- /// Could be written as
++ /// let _ = x.iter().zip(0..x.len());
+ /// ```
- /// x.iter().enumerate();
++ ///
++ /// Use instead:
+ /// ```rust
+ /// # let x = vec![1];
- /// ```rust,ignore
- /// for x..(y+1) { .. }
++ /// let _ = 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
- /// Could be written as
- /// ```rust,ignore
- /// for x..=y { .. }
++ /// ```rust
++ /// # let x = 0;
++ /// # let y = 1;
++ /// for i in x..(y+1) {
++ /// // ..
++ /// }
+ /// ```
- /// ```rust,ignore
- /// for x..=(y-1) { .. }
++ ///
++ /// Use instead:
++ /// ```rust
++ /// # let x = 0;
++ /// # let y = 1;
++ /// for i in 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
- /// Could be written as
- /// ```rust,ignore
- /// for x..y { .. }
++ /// ```rust
++ /// # let x = 0;
++ /// # let y = 1;
++ /// for i in x..=(y-1) {
++ /// // ..
++ /// }
+ /// ```
++ ///
++ /// Use instead:
++ /// ```rust
++ /// # let x = 0;
++ /// # let y = 1;
++ /// for i in 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) {
+ 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
--- /dev/null
++use clippy_utils::{
++ diagnostics::{span_lint, span_lint_and_sugg},
++ higher::{get_vec_init_kind, VecInitKind},
++ source::snippet,
++ visitors::expr_visitor_no_bodies,
++};
++use hir::{intravisit::Visitor, ExprKind, Local, PatKind, PathSegment, QPath, StmtKind};
++use rustc_errors::Applicability;
++use rustc_hir as hir;
++use rustc_lint::{LateContext, LateLintPass};
++use rustc_session::{declare_lint_pass, declare_tool_lint};
++
++declare_clippy_lint! {
++ /// ### What it does
++ /// This lint catches reads into a zero-length `Vec`.
++ /// Especially in the case of a call to `with_capacity`, this lint warns that read
++ /// gets the number of bytes from the `Vec`'s length, not its capacity.
++ ///
++ /// ### Why is this bad?
++ /// Reading zero bytes is almost certainly not the intended behavior.
++ ///
++ /// ### Known problems
++ /// In theory, a very unusual read implementation could assign some semantic meaning
++ /// to zero-byte reads. But it seems exceptionally unlikely that code intending to do
++ /// a zero-byte read would allocate a `Vec` for it.
++ ///
++ /// ### Example
++ /// ```rust
++ /// use std::io;
++ /// fn foo<F: io::Read>(mut f: F) {
++ /// let mut data = Vec::with_capacity(100);
++ /// f.read(&mut data).unwrap();
++ /// }
++ /// ```
++ /// Use instead:
++ /// ```rust
++ /// use std::io;
++ /// fn foo<F: io::Read>(mut f: F) {
++ /// let mut data = Vec::with_capacity(100);
++ /// data.resize(100, 0);
++ /// f.read(&mut data).unwrap();
++ /// }
++ /// ```
++ #[clippy::version = "1.63.0"]
++ pub READ_ZERO_BYTE_VEC,
++ correctness,
++ "checks for reads into a zero-length `Vec`"
++}
++declare_lint_pass!(ReadZeroByteVec => [READ_ZERO_BYTE_VEC]);
++
++impl<'tcx> LateLintPass<'tcx> for ReadZeroByteVec {
++ fn check_block(&mut self, cx: &LateContext<'tcx>, block: &hir::Block<'tcx>) {
++ for (idx, stmt) in block.stmts.iter().enumerate() {
++ if !stmt.span.from_expansion()
++ // matches `let v = Vec::new();`
++ && let StmtKind::Local(local) = stmt.kind
++ && let Local { pat, init: Some(init), .. } = local
++ && let PatKind::Binding(_, _, ident, _) = pat.kind
++ && let Some(vec_init_kind) = get_vec_init_kind(cx, init)
++ {
++ // finds use of `_.read(&mut v)`
++ let mut read_found = false;
++ let mut visitor = expr_visitor_no_bodies(|expr| {
++ if let ExprKind::MethodCall(path, [_self, arg], _) = expr.kind
++ && let PathSegment { ident: read_or_read_exact, .. } = *path
++ && matches!(read_or_read_exact.as_str(), "read" | "read_exact")
++ && let ExprKind::AddrOf(_, hir::Mutability::Mut, inner) = arg.kind
++ && let ExprKind::Path(QPath::Resolved(None, inner_path)) = inner.kind
++ && let [inner_seg] = inner_path.segments
++ && ident.name == inner_seg.ident.name
++ {
++ read_found = true;
++ }
++ !read_found
++ });
++
++ let next_stmt_span;
++ if idx == block.stmts.len() - 1 {
++ // case { .. stmt; expr }
++ if let Some(e) = block.expr {
++ visitor.visit_expr(e);
++ next_stmt_span = e.span;
++ } else {
++ return;
++ }
++ } else {
++ // case { .. stmt; stmt; .. }
++ let next_stmt = &block.stmts[idx + 1];
++ visitor.visit_stmt(next_stmt);
++ next_stmt_span = next_stmt.span;
++ }
++ drop(visitor);
++
++ if read_found && !next_stmt_span.from_expansion() {
++ let applicability = Applicability::MaybeIncorrect;
++ match vec_init_kind {
++ VecInitKind::WithConstCapacity(len) => {
++ span_lint_and_sugg(
++ cx,
++ READ_ZERO_BYTE_VEC,
++ next_stmt_span,
++ "reading zero byte data to `Vec`",
++ "try",
++ format!("{}.resize({}, 0); {}",
++ ident.as_str(),
++ len,
++ snippet(cx, next_stmt_span, "..")
++ ),
++ applicability,
++ );
++ }
++ VecInitKind::WithExprCapacity(hir_id) => {
++ let e = cx.tcx.hir().expect_expr(hir_id);
++ span_lint_and_sugg(
++ cx,
++ READ_ZERO_BYTE_VEC,
++ next_stmt_span,
++ "reading zero byte data to `Vec`",
++ "try",
++ format!("{}.resize({}, 0); {}",
++ ident.as_str(),
++ snippet(cx, e.span, ".."),
++ snippet(cx, next_stmt_span, "..")
++ ),
++ applicability,
++ );
++ }
++ _ => {
++ span_lint(
++ cx,
++ READ_ZERO_BYTE_VEC,
++ next_stmt_span,
++ "reading zero byte data to `Vec`",
++ );
++
++ }
++ }
++ }
++ }
++ }
++ }
++}
--- /dev/null
- /// ```rust,ignore
- /// // Bad
- /// let a = (|| 42)()
+use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
+use clippy_utils::source::snippet_with_applicability;
+use if_chain::if_chain;
+use rustc_ast::ast;
+use rustc_ast::visit as ast_visit;
+use rustc_ast::visit::Visitor as AstVisitor;
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::intravisit as hir_visit;
+use rustc_hir::intravisit::Visitor as HirVisitor;
+use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::nested_filter;
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Detects closures called in the same expression where they
+ /// are defined.
+ ///
+ /// ### Why is this bad?
+ /// It is unnecessarily adding to the expression's
+ /// complexity.
+ ///
+ /// ### Example
- /// // Good
- /// let a = 42
++ /// ```rust
++ /// let a = (|| 42)();
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// let a = 42;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub REDUNDANT_CLOSURE_CALL,
+ complexity,
+ "throwaway closures called in the expression they are defined"
+}
+
+declare_lint_pass!(RedundantClosureCall => [REDUNDANT_CLOSURE_CALL]);
+
+// Used to find `return` statements or equivalents e.g., `?`
+struct ReturnVisitor {
+ found_return: bool,
+}
+
+impl ReturnVisitor {
+ #[must_use]
+ fn new() -> Self {
+ Self { found_return: false }
+ }
+}
+
+impl<'ast> ast_visit::Visitor<'ast> for ReturnVisitor {
+ fn visit_expr(&mut self, ex: &'ast ast::Expr) {
+ if let ast::ExprKind::Ret(_) | ast::ExprKind::Try(_) = ex.kind {
+ self.found_return = true;
+ }
+
+ ast_visit::walk_expr(self, ex);
+ }
+}
+
+impl EarlyLintPass for RedundantClosureCall {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+ if_chain! {
+ if let ast::ExprKind::Call(ref paren, _) = expr.kind;
+ if let ast::ExprKind::Paren(ref closure) = paren.kind;
+ if let ast::ExprKind::Closure(_, _, _, ref decl, ref block, _) = closure.kind;
+ then {
+ let mut visitor = ReturnVisitor::new();
+ visitor.visit_expr(block);
+ if !visitor.found_return {
+ span_lint_and_then(
+ cx,
+ REDUNDANT_CLOSURE_CALL,
+ expr.span,
+ "try not to call a closure in the expression where it is declared",
+ |diag| {
+ if decl.inputs.is_empty() {
+ let mut app = Applicability::MachineApplicable;
+ let hint =
+ snippet_with_applicability(cx, block.span, "..", &mut app).into_owned();
+ diag.span_suggestion(expr.span, "try doing something like", hint, app);
+ }
+ },
+ );
+ }
+ }
+ }
+ }
+}
+
+impl<'tcx> LateLintPass<'tcx> for RedundantClosureCall {
+ fn check_block(&mut self, cx: &LateContext<'tcx>, block: &'tcx hir::Block<'_>) {
+ fn count_closure_usage<'a, 'tcx>(
+ cx: &'a LateContext<'tcx>,
+ block: &'tcx hir::Block<'_>,
+ path: &'tcx hir::Path<'tcx>,
+ ) -> usize {
+ struct ClosureUsageCount<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ path: &'tcx hir::Path<'tcx>,
+ count: usize,
+ }
+ impl<'a, 'tcx> hir_visit::Visitor<'tcx> for ClosureUsageCount<'a, 'tcx> {
+ type NestedFilter = nested_filter::OnlyBodies;
+
+ fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
+ if_chain! {
+ if let hir::ExprKind::Call(closure, _) = expr.kind;
+ if let hir::ExprKind::Path(hir::QPath::Resolved(_, path)) = closure.kind;
+ if self.path.segments[0].ident == path.segments[0].ident;
+ if self.path.res == path.res;
+ then {
+ self.count += 1;
+ }
+ }
+ hir_visit::walk_expr(self, expr);
+ }
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+ }
+ let mut closure_usage_count = ClosureUsageCount { cx, path, count: 0 };
+ closure_usage_count.visit_block(block);
+ closure_usage_count.count
+ }
+
+ for w in block.stmts.windows(2) {
+ if_chain! {
+ if let hir::StmtKind::Local(local) = w[0].kind;
+ if let Option::Some(t) = local.init;
+ if let hir::ExprKind::Closure { .. } = t.kind;
+ if let hir::PatKind::Binding(_, _, ident, _) = local.pat.kind;
+ if let hir::StmtKind::Semi(second) = w[1].kind;
+ if let hir::ExprKind::Assign(_, call, _) = second.kind;
+ if let hir::ExprKind::Call(closure, _) = call.kind;
+ if let hir::ExprKind::Path(hir::QPath::Resolved(_, path)) = closure.kind;
+ if ident == path.segments[0].ident;
+ if count_closure_usage(cx, block, path) == 1;
+ then {
+ span_lint(
+ cx,
+ REDUNDANT_CLOSURE_CALL,
+ second.span,
+ "closure called just once immediately after it was declared",
+ );
+ }
+ }
+ }
+ }
+}
--- /dev/null
- #[clippy::version = "1.60.0"]
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::get_parent_expr;
+use clippy_utils::source::snippet_with_context;
+use clippy_utils::ty::{is_type_lang_item, peel_mid_ty_refs};
+use if_chain::if_chain;
+use rustc_ast::util::parser::PREC_PREFIX;
+use rustc_errors::Applicability;
+use rustc_hir::{BorrowKind, Expr, ExprKind, LangItem, Mutability};
+use rustc_lint::{LateContext, LateLintPass, Lint};
+use rustc_middle::ty::adjustment::{Adjust, AutoBorrow, AutoBorrowMutability};
+use rustc_middle::ty::subst::GenericArg;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for redundant slicing expressions which use the full range, and
+ /// do not change the type.
+ ///
+ /// ### Why is this bad?
+ /// It unnecessarily adds complexity to the expression.
+ ///
+ /// ### Known problems
+ /// If the type being sliced has an implementation of `Index<RangeFull>`
+ /// that actually changes anything then it can't be removed. However, this would be surprising
+ /// to people reading the code and should have a note with it.
+ ///
+ /// ### Example
+ /// ```ignore
+ /// fn get_slice(x: &[u32]) -> &[u32] {
+ /// &x[..]
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```ignore
+ /// fn get_slice(x: &[u32]) -> &[u32] {
+ /// x
+ /// }
+ /// ```
+ #[clippy::version = "1.51.0"]
+ pub REDUNDANT_SLICING,
+ complexity,
+ "redundant slicing of the whole range of a type"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for slicing expressions which are equivalent to dereferencing the
+ /// value.
+ ///
+ /// ### Why is this bad?
+ /// Some people may prefer to dereference rather than slice.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let vec = vec![1, 2, 3];
+ /// let slice = &vec[..];
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let vec = vec![1, 2, 3];
+ /// let slice = &*vec;
+ /// ```
++ #[clippy::version = "1.61.0"]
+ pub DEREF_BY_SLICING,
+ restriction,
+ "slicing instead of dereferencing"
+}
+
+declare_lint_pass!(RedundantSlicing => [REDUNDANT_SLICING, DEREF_BY_SLICING]);
+
+static REDUNDANT_SLICING_LINT: (&Lint, &str) = (REDUNDANT_SLICING, "redundant slicing of the whole range");
+static DEREF_BY_SLICING_LINT: (&Lint, &str) = (DEREF_BY_SLICING, "slicing when dereferencing would work");
+
+impl<'tcx> LateLintPass<'tcx> for RedundantSlicing {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if expr.span.from_expansion() {
+ return;
+ }
+
+ let ctxt = expr.span.ctxt();
+ if_chain! {
+ if let ExprKind::AddrOf(BorrowKind::Ref, mutability, addressee) = expr.kind;
+ if addressee.span.ctxt() == ctxt;
+ if let ExprKind::Index(indexed, range) = addressee.kind;
+ if is_type_lang_item(cx, cx.typeck_results().expr_ty_adjusted(range), LangItem::RangeFull);
+ then {
+ let (expr_ty, expr_ref_count) = peel_mid_ty_refs(cx.typeck_results().expr_ty(expr));
+ let (indexed_ty, indexed_ref_count) = peel_mid_ty_refs(cx.typeck_results().expr_ty(indexed));
+ let parent_expr = get_parent_expr(cx, expr);
+ let needs_parens_for_prefix = parent_expr.map_or(false, |parent| {
+ parent.precedence().order() > PREC_PREFIX
+ });
+ let mut app = Applicability::MachineApplicable;
+
+ let ((lint, msg), help, sugg) = if expr_ty == indexed_ty {
+ if expr_ref_count > indexed_ref_count {
+ // Indexing takes self by reference and can't return a reference to that
+ // reference as it's a local variable. The only way this could happen is if
+ // `self` contains a reference to the `Self` type. If this occurs then the
+ // lint no longer applies as it's essentially a field access, which is not
+ // redundant.
+ return;
+ }
+ let deref_count = indexed_ref_count - expr_ref_count;
+
+ let (lint, reborrow_str, help_str) = if mutability == Mutability::Mut {
+ // The slice was used to reborrow the mutable reference.
+ (DEREF_BY_SLICING_LINT, "&mut *", "reborrow the original value instead")
+ } else if matches!(
+ parent_expr,
+ Some(Expr {
+ kind: ExprKind::AddrOf(BorrowKind::Ref, Mutability::Mut, _),
+ ..
+ })
+ ) || cx.typeck_results().expr_adjustments(expr).first().map_or(false, |a| {
+ matches!(a.kind, Adjust::Borrow(AutoBorrow::Ref(_, AutoBorrowMutability::Mut { .. })))
+ }) {
+ // The slice was used to make a temporary reference.
+ (DEREF_BY_SLICING_LINT, "&*", "reborrow the original value instead")
+ } else if deref_count != 0 {
+ (DEREF_BY_SLICING_LINT, "", "dereference the original value instead")
+ } else {
+ (REDUNDANT_SLICING_LINT, "", "use the original value instead")
+ };
+
+ let snip = snippet_with_context(cx, indexed.span, ctxt, "..", &mut app).0;
+ let sugg = if (deref_count != 0 || !reborrow_str.is_empty()) && needs_parens_for_prefix {
+ format!("({}{}{})", reborrow_str, "*".repeat(deref_count), snip)
+ } else {
+ format!("{}{}{}", reborrow_str, "*".repeat(deref_count), snip)
+ };
+
+ (lint, help_str, sugg)
+ } else if let Some(target_id) = cx.tcx.lang_items().deref_target() {
+ if let Ok(deref_ty) = cx.tcx.try_normalize_erasing_regions(
+ cx.param_env,
+ cx.tcx.mk_projection(target_id, cx.tcx.mk_substs([GenericArg::from(indexed_ty)].into_iter())),
+ ) {
+ if deref_ty == expr_ty {
+ let snip = snippet_with_context(cx, indexed.span, ctxt, "..", &mut app).0;
+ let sugg = if needs_parens_for_prefix {
+ format!("(&{}{}*{})", mutability.prefix_str(), "*".repeat(indexed_ref_count), snip)
+ } else {
+ format!("&{}{}*{}", mutability.prefix_str(), "*".repeat(indexed_ref_count), snip)
+ };
+ (DEREF_BY_SLICING_LINT, "dereference the original value instead", sugg)
+ } else {
+ return;
+ }
+ } else {
+ return;
+ }
+ } else {
+ return;
+ };
+
+ span_lint_and_sugg(
+ cx,
+ lint,
+ expr.span,
+ msg,
+ help,
+ sugg,
+ app,
+ );
+ }
+ }
+ }
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::{snippet_opt, snippet_with_applicability};
+use if_chain::if_chain;
+use rustc_ast::ast::{Expr, ExprKind, Mutability, UnOp};
+use rustc_errors::Applicability;
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::BytePos;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `*&` and `*&mut` in expressions.
+ ///
+ /// ### Why is this bad?
+ /// Immediately dereferencing a reference is no-op and
+ /// makes the code less clear.
+ ///
+ /// ### Known problems
+ /// Multiple dereference/addrof pairs are not handled so
+ /// the suggested fix for `x = **&&y` is `x = *&y`, which is still incorrect.
+ ///
+ /// ### Example
+ /// ```rust,ignore
- /// // Good
+ /// let a = f(*&mut b);
+ /// let c = *&d;
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust,ignore
+ /// let a = f(b);
+ /// let c = d;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub DEREF_ADDROF,
+ complexity,
+ "use of `*&` or `*&mut` in an expression"
+}
+
+declare_lint_pass!(DerefAddrOf => [DEREF_ADDROF]);
+
+fn without_parens(mut e: &Expr) -> &Expr {
+ while let ExprKind::Paren(ref child_e) = e.kind {
+ e = child_e;
+ }
+ e
+}
+
+impl EarlyLintPass for DerefAddrOf {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &Expr) {
+ if_chain! {
+ if let ExprKind::Unary(UnOp::Deref, ref deref_target) = e.kind;
+ if let ExprKind::AddrOf(_, ref mutability, ref addrof_target) = without_parens(deref_target).kind;
+ if deref_target.span.ctxt() == e.span.ctxt();
+ if !addrof_target.span.from_expansion();
+ then {
+ let mut applicability = Applicability::MachineApplicable;
+ let sugg = if e.span.from_expansion() {
+ if let Some(macro_source) = snippet_opt(cx, e.span) {
+ // Remove leading whitespace from the given span
+ // e.g: ` $visitor` turns into `$visitor`
+ let trim_leading_whitespaces = |span| {
+ snippet_opt(cx, span).and_then(|snip| {
+ #[expect(clippy::cast_possible_truncation)]
+ snip.find(|c: char| !c.is_whitespace()).map(|pos| {
+ span.lo() + BytePos(pos as u32)
+ })
+ }).map_or(span, |start_no_whitespace| e.span.with_lo(start_no_whitespace))
+ };
+
+ let mut generate_snippet = |pattern: &str| {
+ #[expect(clippy::cast_possible_truncation)]
+ macro_source.rfind(pattern).map(|pattern_pos| {
+ let rpos = pattern_pos + pattern.len();
+ let span_after_ref = e.span.with_lo(BytePos(e.span.lo().0 + rpos as u32));
+ let span = trim_leading_whitespaces(span_after_ref);
+ snippet_with_applicability(cx, span, "_", &mut applicability)
+ })
+ };
+
+ if *mutability == Mutability::Mut {
+ generate_snippet("mut")
+ } else {
+ generate_snippet("&")
+ }
+ } else {
+ Some(snippet_with_applicability(cx, e.span, "_", &mut applicability))
+ }
+ } else {
+ Some(snippet_with_applicability(cx, addrof_target.span, "_", &mut applicability))
+ };
+ if let Some(sugg) = sugg {
+ span_lint_and_sugg(
+ cx,
+ DEREF_ADDROF,
+ e.span,
+ "immediately dereferencing a reference",
+ "try this",
+ sugg.to_string(),
+ applicability,
+ );
+ }
+ }
+ }
+ }
+}
--- /dev/null
- /// Missing attribute
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::ty::is_must_use_ty;
+use clippy_utils::{nth_arg, return_ty};
+use rustc_hir::def_id::LocalDefId;
+use rustc_hir::intravisit::FnKind;
+use rustc_hir::{Body, FnDecl, HirId, TraitItem, TraitItemKind};
+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, Span};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint warns when a method returning `Self` doesn't have the `#[must_use]` attribute.
+ ///
+ /// ### Why is this bad?
+ /// Methods returning `Self` often create new values, having the `#[must_use]` attribute
+ /// prevents users from "forgetting" to use the newly created value.
+ ///
+ /// The `#[must_use]` attribute can be added to the type itself to ensure that instances
+ /// are never forgotten. Functions returning a type marked with `#[must_use]` will not be
+ /// linted, as the usage is already enforced by the type attribute.
+ ///
+ /// ### Limitations
+ /// This lint is only applied on methods taking a `self` argument. It would be mostly noise
+ /// if it was added on constructors for example.
+ ///
+ /// ### Example
- /// // Bad
+ /// ```rust
+ /// pub struct Bar;
+ /// impl Bar {
- /// It's better to have the `#[must_use]` attribute on the method like this:
++ /// // Missing attribute
+ /// pub fn bar(&self) -> Self {
+ /// Self
+ /// }
+ /// }
+ /// ```
+ ///
- /// ```
++ /// Use instead:
+ /// ```rust
++ /// # {
++ /// // It's better to have the `#[must_use]` attribute on the method like this:
+ /// pub struct Bar;
+ /// impl Bar {
+ /// #[must_use]
+ /// pub fn bar(&self) -> Self {
+ /// Self
+ /// }
+ /// }
- /// Or on the type definition like this:
- /// ```rust
++ /// # }
+ ///
++ /// # {
++ /// // Or on the type definition like this:
+ /// #[must_use]
+ /// pub struct Bar;
+ /// impl Bar {
+ /// pub fn bar(&self) -> Self {
+ /// Self
+ /// }
+ /// }
++ /// # }
+ /// ```
+ #[clippy::version = "1.59.0"]
+ pub RETURN_SELF_NOT_MUST_USE,
+ pedantic,
+ "missing `#[must_use]` annotation on a method returning `Self`"
+}
+
+declare_lint_pass!(ReturnSelfNotMustUse => [RETURN_SELF_NOT_MUST_USE]);
+
+fn check_method(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_def: LocalDefId, span: Span, hir_id: HirId) {
+ if_chain! {
+ // If it comes from an external macro, better ignore it.
+ if !in_external_macro(cx.sess(), span);
+ if decl.implicit_self.has_implicit_self();
+ // We only show this warning for public exported methods.
+ if cx.access_levels.is_exported(fn_def);
+ // We don't want to emit this lint if the `#[must_use]` attribute is already there.
+ if !cx.tcx.hir().attrs(hir_id).iter().any(|attr| attr.has_name(sym::must_use));
+ if cx.tcx.visibility(fn_def.to_def_id()).is_public();
+ let ret_ty = return_ty(cx, hir_id);
+ let self_arg = nth_arg(cx, hir_id, 0);
+ // If `Self` has the same type as the returned type, then we want to warn.
+ //
+ // For this check, we don't want to remove the reference on the returned type because if
+ // there is one, we shouldn't emit a warning!
+ if self_arg.peel_refs() == ret_ty;
+ // If `Self` is already marked as `#[must_use]`, no need for the attribute here.
+ if !is_must_use_ty(cx, ret_ty);
+
+ then {
+ span_lint_and_help(
+ cx,
+ RETURN_SELF_NOT_MUST_USE,
+ span,
+ "missing `#[must_use]` attribute on a method returning `Self`",
+ None,
+ "consider adding the `#[must_use]` attribute to the method or directly to the `Self` type"
+ );
+ }
+ }
+}
+
+impl<'tcx> LateLintPass<'tcx> for ReturnSelfNotMustUse {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ kind: FnKind<'tcx>,
+ decl: &'tcx FnDecl<'tcx>,
+ _: &'tcx Body<'tcx>,
+ span: Span,
+ hir_id: HirId,
+ ) {
+ if_chain! {
+ // We are only interested in methods, not in functions or associated functions.
+ if matches!(kind, FnKind::Method(_, _));
+ if let Some(fn_def) = cx.tcx.hir().opt_local_def_id(hir_id);
+ if let Some(impl_def) = cx.tcx.impl_of_method(fn_def.to_def_id());
+ // We don't want this method to be te implementation of a trait because the
+ // `#[must_use]` should be put on the trait definition directly.
+ if cx.tcx.trait_id_of_impl(impl_def).is_none();
+
+ then {
+ check_method(cx, decl, fn_def, span, hir_id);
+ }
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'tcx>) {
+ if let TraitItemKind::Fn(ref sig, _) = item.kind {
+ check_method(cx, sig.decl, item.def_id, item.span, item.hir_id());
+ }
+ }
+}
--- /dev/null
- use clippy_utils::diagnostics::span_lint_and_then;
++use clippy_utils::diagnostics::span_lint_hir_and_then;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_hir::def::{DefKind, Res};
- use rustc_hir::{Impl, ItemKind, Node, Path, QPath, TraitRef, TyKind};
++use rustc_hir::{HirId, Impl, ItemKind, Node, Path, QPath, TraitRef, TyKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::AssocKind;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::Symbol;
+use rustc_span::Span;
+use std::collections::{BTreeMap, BTreeSet};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// It lints if a struct has two methods with the same name:
+ /// one from a trait, another not from trait.
+ ///
+ /// ### Why is this bad?
+ /// Confusing.
+ ///
+ /// ### Example
+ /// ```rust
+ /// trait T {
+ /// fn foo(&self) {}
+ /// }
+ ///
+ /// struct S;
+ ///
+ /// impl T for S {
+ /// fn foo(&self) {}
+ /// }
+ ///
+ /// impl S {
+ /// fn foo(&self) {}
+ /// }
+ /// ```
+ #[clippy::version = "1.57.0"]
+ pub SAME_NAME_METHOD,
+ restriction,
+ "two method with same name"
+}
+
+declare_lint_pass!(SameNameMethod => [SAME_NAME_METHOD]);
+
+struct ExistingName {
- impl_methods: BTreeMap<Symbol, Span>,
++ impl_methods: BTreeMap<Symbol, (Span, HirId)>,
+ trait_methods: BTreeMap<Symbol, Vec<Span>>,
+}
+
+impl<'tcx> LateLintPass<'tcx> for SameNameMethod {
++ #[expect(clippy::too_many_lines)]
+ fn check_crate_post(&mut self, cx: &LateContext<'tcx>) {
+ let mut map = FxHashMap::<Res, ExistingName>::default();
+
+ for id in cx.tcx.hir().items() {
+ if matches!(cx.tcx.def_kind(id.def_id), DefKind::Impl)
+ && let item = cx.tcx.hir().item(id)
+ && let ItemKind::Impl(Impl {
+ items,
+ of_trait,
+ self_ty,
+ ..
+ }) = &item.kind
+ && let TyKind::Path(QPath::Resolved(_, Path { res, .. })) = self_ty.kind
+ {
+ if !map.contains_key(res) {
+ map.insert(
+ *res,
+ ExistingName {
+ impl_methods: BTreeMap::new(),
+ trait_methods: BTreeMap::new(),
+ },
+ );
+ }
+ let existing_name = map.get_mut(res).unwrap();
+
+ match of_trait {
+ Some(trait_ref) => {
+ let mut methods_in_trait: BTreeSet<Symbol> = if_chain! {
+ if let Some(Node::TraitRef(TraitRef { path, .. })) =
+ cx.tcx.hir().find(trait_ref.hir_ref_id);
+ if let Res::Def(DefKind::Trait, did) = path.res;
+ then{
+ // FIXME: if
+ // `rustc_middle::ty::assoc::AssocItems::items` is public,
+ // we can iterate its keys instead of `in_definition_order`,
+ // which's more efficient
+ cx.tcx
+ .associated_items(did)
+ .in_definition_order()
+ .filter(|assoc_item| {
+ matches!(assoc_item.kind, AssocKind::Fn)
+ })
+ .map(|assoc_item| assoc_item.name)
+ .collect()
+ }else{
+ BTreeSet::new()
+ }
+ };
+
+ let mut check_trait_method = |method_name: Symbol, trait_method_span: Span| {
- if let Some(impl_span) = existing_name.impl_methods.get(&method_name) {
- span_lint_and_then(
++ if let Some((impl_span, hir_id)) = existing_name.impl_methods.get(&method_name) {
++ span_lint_hir_and_then(
+ cx,
+ SAME_NAME_METHOD,
++ *hir_id,
+ *impl_span,
+ "method's name is the same as an existing method in a trait",
+ |diag| {
+ diag.span_note(
+ trait_method_span,
+ &format!("existing `{}` defined here", method_name),
+ );
+ },
+ );
+ }
+ if let Some(v) = existing_name.trait_methods.get_mut(&method_name) {
+ v.push(trait_method_span);
+ } else {
+ existing_name.trait_methods.insert(method_name, vec![trait_method_span]);
+ }
+ };
+
+ for impl_item_ref in (*items).iter().filter(|impl_item_ref| {
+ matches!(impl_item_ref.kind, rustc_hir::AssocItemKind::Fn { .. })
+ }) {
+ let method_name = impl_item_ref.ident.name;
+ methods_in_trait.remove(&method_name);
+ check_trait_method(method_name, impl_item_ref.span);
+ }
+
+ for method_name in methods_in_trait {
+ check_trait_method(method_name, item.span);
+ }
+ },
+ None => {
+ for impl_item_ref in (*items).iter().filter(|impl_item_ref| {
+ matches!(impl_item_ref.kind, rustc_hir::AssocItemKind::Fn { .. })
+ }) {
+ let method_name = impl_item_ref.ident.name;
+ let impl_span = impl_item_ref.span;
++ let hir_id = impl_item_ref.id.hir_id();
+ if let Some(trait_spans) = existing_name.trait_methods.get(&method_name) {
- span_lint_and_then(
++ span_lint_hir_and_then(
+ cx,
+ SAME_NAME_METHOD,
++ hir_id,
+ impl_span,
+ "method's name is the same as an existing method in a trait",
+ |diag| {
+ // TODO should we `span_note` on every trait?
+ // iterate on trait_spans?
+ diag.span_note(
+ trait_spans[0],
+ &format!("existing `{}` defined here", method_name),
+ );
+ },
+ );
+ }
- existing_name.impl_methods.insert(method_name, impl_span);
++ existing_name.impl_methods.insert(method_name, (impl_span, hir_id));
+ }
+ },
+ }
+ }
+ }
+ }
+}
--- /dev/null
- /// // Bad
+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;
+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;
- /// // Good
+ /// let x = &x;
++ /// ```
+ ///
- ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # let x = 1;
+ /// 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;
- /// // Good
+ /// let x = z; // shadows the earlier binding
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # let y = 1;
++ /// # let z = 2;
++ /// let x = y;
+ /// 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
+ ) {
+ self.bindings.push(FxHashMap::default());
+ }
+ }
+
+ fn check_body_post(&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
+ ) {
+ 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, "_"));
+ (SHADOW_UNRELATED, msg)
+ },
+ };
+ 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
- #[clippy::version = "1.59.0"]
+use clippy_utils::diagnostics::span_lint_and_help;
+use rustc_ast::ast::{GenericParam, GenericParamKind};
+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 lifetimes with names which are one character
+ /// long.
+ ///
+ /// ### Why is this bad?
+ /// A single character is likely not enough to express the
+ /// purpose of a lifetime. Using a longer name can make code
+ /// easier to understand, especially for those who are new to
+ /// Rust.
+ ///
+ /// ### Known problems
+ /// Rust programmers and learning resources tend to use single
+ /// character lifetimes, so this lint is at odds with the
+ /// ecosystem at large. In addition, the lifetime's purpose may
+ /// be obvious or, rarely, expressible in one character.
+ ///
+ /// ### Example
+ /// ```rust
+ /// struct DiagnosticCtx<'a> {
+ /// source: &'a str,
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// struct DiagnosticCtx<'src> {
+ /// source: &'src str,
+ /// }
+ /// ```
++ #[clippy::version = "1.60.0"]
+ pub SINGLE_CHAR_LIFETIME_NAMES,
+ restriction,
+ "warns against single-character lifetime names"
+}
+
+declare_lint_pass!(SingleCharLifetimeNames => [SINGLE_CHAR_LIFETIME_NAMES]);
+
+impl EarlyLintPass for SingleCharLifetimeNames {
+ fn check_generic_param(&mut self, ctx: &EarlyContext<'_>, param: &GenericParam) {
+ if in_external_macro(ctx.sess(), param.ident.span) {
+ return;
+ }
+
+ if let GenericParamKind::Lifetime = param.kind {
+ if !param.is_placeholder && param.ident.as_str().len() <= 2 {
+ span_lint_and_help(
+ ctx,
+ SINGLE_CHAR_LIFETIME_NAMES,
+ param.ident.span,
+ "single-character lifetime names are likely uninformative",
+ None,
+ "use a more informative name",
+ );
+ }
+ }
+ }
+}
--- /dev/null
- ///
- /// // Bad
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::sugg::Sugg;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::{get_enclosing_block, is_expr_path_def_path, path_to_local, path_to_local_id, paths, SpanlessEq};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::{walk_block, walk_expr, walk_stmt, Visitor};
+use rustc_hir::{BindingAnnotation, Block, Expr, ExprKind, HirId, PatKind, QPath, Stmt, StmtKind};
+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 slow zero-filled vector initialization
+ ///
+ /// ### Why is this bad?
+ /// These structures are non-idiomatic and less efficient than simply using
+ /// `vec![0; len]`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use core::iter::repeat;
+ /// # let len = 4;
- /// // Good
+ /// let mut vec1 = Vec::with_capacity(len);
+ /// vec1.resize(len, 0);
+ ///
+ /// let mut vec2 = Vec::with_capacity(len);
+ /// vec2.extend(repeat(0).take(len));
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # let len = 4;
+ /// let mut vec1 = vec![0; len];
+ /// let mut vec2 = vec![0; len];
+ /// ```
+ #[clippy::version = "1.32.0"]
+ pub SLOW_VECTOR_INITIALIZATION,
+ perf,
+ "slow vector initialization"
+}
+
+declare_lint_pass!(SlowVectorInit => [SLOW_VECTOR_INITIALIZATION]);
+
+/// `VecAllocation` contains data regarding a vector allocated with `with_capacity` and then
+/// assigned to a variable. For example, `let mut vec = Vec::with_capacity(0)` or
+/// `vec = Vec::with_capacity(0)`
+struct VecAllocation<'tcx> {
+ /// HirId of the variable
+ local_id: HirId,
+
+ /// Reference to the expression which allocates the vector
+ allocation_expr: &'tcx Expr<'tcx>,
+
+ /// Reference to the expression used as argument on `with_capacity` call. This is used
+ /// to only match slow zero-filling idioms of the same length than vector initialization.
+ len_expr: &'tcx Expr<'tcx>,
+}
+
+/// Type of slow initialization
+enum InitializationType<'tcx> {
+ /// Extend is a slow initialization with the form `vec.extend(repeat(0).take(..))`
+ Extend(&'tcx Expr<'tcx>),
+
+ /// Resize is a slow initialization with the form `vec.resize(.., 0)`
+ Resize(&'tcx Expr<'tcx>),
+}
+
+impl<'tcx> LateLintPass<'tcx> for SlowVectorInit {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ // Matches initialization on reassignements. For example: `vec = Vec::with_capacity(100)`
+ if_chain! {
+ if let ExprKind::Assign(left, right, _) = expr.kind;
+
+ // Extract variable
+ if let Some(local_id) = path_to_local(left);
+
+ // Extract len argument
+ if let Some(len_arg) = Self::is_vec_with_capacity(cx, right);
+
+ then {
+ let vi = VecAllocation {
+ local_id,
+ allocation_expr: right,
+ len_expr: len_arg,
+ };
+
+ Self::search_initialization(cx, vi, expr.hir_id);
+ }
+ }
+ }
+
+ fn check_stmt(&mut self, cx: &LateContext<'tcx>, stmt: &'tcx Stmt<'_>) {
+ // Matches statements which initializes vectors. For example: `let mut vec = Vec::with_capacity(10)`
+ if_chain! {
+ if let StmtKind::Local(local) = stmt.kind;
+ if let PatKind::Binding(BindingAnnotation::Mutable, local_id, _, None) = local.pat.kind;
+ if let Some(init) = local.init;
+ if let Some(len_arg) = Self::is_vec_with_capacity(cx, init);
+
+ then {
+ let vi = VecAllocation {
+ local_id,
+ allocation_expr: init,
+ len_expr: len_arg,
+ };
+
+ Self::search_initialization(cx, vi, stmt.hir_id);
+ }
+ }
+ }
+}
+
+impl SlowVectorInit {
+ /// Checks if the given expression is `Vec::with_capacity(..)`. It will return the expression
+ /// of the first argument of `with_capacity` call if it matches or `None` if it does not.
+ fn is_vec_with_capacity<'tcx>(cx: &LateContext<'_>, expr: &Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> {
+ if_chain! {
+ if let ExprKind::Call(func, [arg]) = expr.kind;
+ if let ExprKind::Path(QPath::TypeRelative(ty, name)) = func.kind;
+ if name.ident.as_str() == "with_capacity";
+ if is_type_diagnostic_item(cx, cx.typeck_results().node_type(ty.hir_id), sym::Vec);
+ then {
+ Some(arg)
+ } else {
+ None
+ }
+ }
+ }
+
+ /// Search initialization for the given vector
+ fn search_initialization<'tcx>(cx: &LateContext<'tcx>, vec_alloc: VecAllocation<'tcx>, parent_node: HirId) {
+ let enclosing_body = get_enclosing_block(cx, parent_node);
+
+ if enclosing_body.is_none() {
+ return;
+ }
+
+ let mut v = VectorInitializationVisitor {
+ cx,
+ vec_alloc,
+ slow_expression: None,
+ initialization_found: false,
+ };
+
+ v.visit_block(enclosing_body.unwrap());
+
+ if let Some(ref allocation_expr) = v.slow_expression {
+ Self::lint_initialization(cx, allocation_expr, &v.vec_alloc);
+ }
+ }
+
+ fn lint_initialization<'tcx>(
+ cx: &LateContext<'tcx>,
+ initialization: &InitializationType<'tcx>,
+ vec_alloc: &VecAllocation<'_>,
+ ) {
+ match initialization {
+ InitializationType::Extend(e) | InitializationType::Resize(e) => {
+ Self::emit_lint(cx, e, vec_alloc, "slow zero-filling initialization");
+ },
+ };
+ }
+
+ fn emit_lint<'tcx>(cx: &LateContext<'tcx>, slow_fill: &Expr<'_>, vec_alloc: &VecAllocation<'_>, msg: &str) {
+ let len_expr = Sugg::hir(cx, vec_alloc.len_expr, "len");
+
+ span_lint_and_then(cx, SLOW_VECTOR_INITIALIZATION, slow_fill.span, msg, |diag| {
+ diag.span_suggestion(
+ vec_alloc.allocation_expr.span,
+ "consider replace allocation with",
+ format!("vec![0; {}]", len_expr),
+ Applicability::Unspecified,
+ );
+ });
+ }
+}
+
+/// `VectorInitializationVisitor` searches for unsafe or slow vector initializations for the given
+/// vector.
+struct VectorInitializationVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+
+ /// Contains the information.
+ vec_alloc: VecAllocation<'tcx>,
+
+ /// Contains the slow initialization expression, if one was found.
+ slow_expression: Option<InitializationType<'tcx>>,
+
+ /// `true` if the initialization of the vector has been found on the visited block.
+ initialization_found: bool,
+}
+
+impl<'a, 'tcx> VectorInitializationVisitor<'a, 'tcx> {
+ /// Checks if the given expression is extending a vector with `repeat(0).take(..)`
+ fn search_slow_extend_filling(&mut self, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ if self.initialization_found;
+ if let ExprKind::MethodCall(path, [self_arg, extend_arg], _) = expr.kind;
+ if path_to_local_id(self_arg, self.vec_alloc.local_id);
+ if path.ident.name == sym!(extend);
+ if self.is_repeat_take(extend_arg);
+
+ then {
+ self.slow_expression = Some(InitializationType::Extend(expr));
+ }
+ }
+ }
+
+ /// Checks if the given expression is resizing a vector with 0
+ fn search_slow_resize_filling(&mut self, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ if self.initialization_found;
+ if let ExprKind::MethodCall(path, [self_arg, len_arg, fill_arg], _) = expr.kind;
+ if path_to_local_id(self_arg, self.vec_alloc.local_id);
+ if path.ident.name == sym!(resize);
+
+ // Check that is filled with 0
+ if let ExprKind::Lit(ref lit) = fill_arg.kind;
+ if let LitKind::Int(0, _) = lit.node;
+
+ // Check that len expression is equals to `with_capacity` expression
+ if SpanlessEq::new(self.cx).eq_expr(len_arg, self.vec_alloc.len_expr);
+
+ then {
+ self.slow_expression = Some(InitializationType::Resize(expr));
+ }
+ }
+ }
+
+ /// Returns `true` if give expression is `repeat(0).take(...)`
+ fn is_repeat_take(&self, expr: &Expr<'_>) -> bool {
+ if_chain! {
+ if let ExprKind::MethodCall(take_path, take_args, _) = expr.kind;
+ if take_path.ident.name == sym!(take);
+
+ // Check that take is applied to `repeat(0)`
+ if let Some(repeat_expr) = take_args.get(0);
+ if self.is_repeat_zero(repeat_expr);
+
+ // Check that len expression is equals to `with_capacity` expression
+ if let Some(len_arg) = take_args.get(1);
+ if SpanlessEq::new(self.cx).eq_expr(len_arg, self.vec_alloc.len_expr);
+
+ then {
+ return true;
+ }
+ }
+
+ false
+ }
+
+ /// Returns `true` if given expression is `repeat(0)`
+ fn is_repeat_zero(&self, expr: &Expr<'_>) -> bool {
+ if_chain! {
+ if let ExprKind::Call(fn_expr, [repeat_arg]) = expr.kind;
+ if is_expr_path_def_path(self.cx, fn_expr, &paths::ITER_REPEAT);
+ if let ExprKind::Lit(ref lit) = repeat_arg.kind;
+ if let LitKind::Int(0, _) = lit.node;
+
+ then {
+ true
+ } else {
+ false
+ }
+ }
+ }
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for VectorInitializationVisitor<'a, 'tcx> {
+ fn visit_stmt(&mut self, stmt: &'tcx Stmt<'_>) {
+ if self.initialization_found {
+ match stmt.kind {
+ StmtKind::Expr(expr) | StmtKind::Semi(expr) => {
+ self.search_slow_extend_filling(expr);
+ self.search_slow_resize_filling(expr);
+ },
+ _ => (),
+ }
+
+ self.initialization_found = false;
+ } else {
+ walk_stmt(self, stmt);
+ }
+ }
+
+ fn visit_block(&mut self, block: &'tcx Block<'_>) {
+ if self.initialization_found {
+ if let Some(s) = block.stmts.get(0) {
+ self.visit_stmt(s);
+ }
+
+ self.initialization_found = false;
+ } else {
+ walk_block(self, block);
+ }
+ }
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ // Skip all the expressions previous to the vector initialization
+ if self.vec_alloc.allocation_expr.hir_id == expr.hir_id {
+ self.initialization_found = true;
+ }
+
+ walk_expr(self, expr);
+ }
+}
--- /dev/null
- /// // Bad
- /// let bs = "a byte string".as_bytes();
+use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_sugg};
+use clippy_utils::source::{snippet, snippet_with_applicability};
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::{get_parent_expr, is_lint_allowed, match_function_call, method_calls, paths};
+use clippy_utils::{peel_blocks, SpanlessEq};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::def_id::DefId;
+use rustc_hir::{BinOpKind, BorrowKind, Expr, ExprKind, LangItem, QPath};
+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};
+use rustc_span::source_map::Spanned;
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for string appends of the form `x = x + y` (without
+ /// `let`!).
+ ///
+ /// ### Why is this bad?
+ /// It's not really bad, but some people think that the
+ /// `.push_str(_)` method is more readable.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let mut x = "Hello".to_owned();
+ /// x = x + ", World";
+ ///
+ /// // More readable
+ /// x += ", World";
+ /// x.push_str(", World");
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub STRING_ADD_ASSIGN,
+ pedantic,
+ "using `x = x + ..` where x is a `String` instead of `push_str()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for all instances of `x + _` where `x` is of type
+ /// `String`, but only if [`string_add_assign`](#string_add_assign) does *not*
+ /// match.
+ ///
+ /// ### Why is this bad?
+ /// It's not bad in and of itself. However, this particular
+ /// `Add` implementation is asymmetric (the other operand need not be `String`,
+ /// but `x` does), while addition as mathematically defined is symmetric, also
+ /// the `String::push_str(_)` function is a perfectly good replacement.
+ /// Therefore, some dislike it and wish not to have it in their code.
+ ///
+ /// That said, other people think that string addition, having a long tradition
+ /// in other languages is actually fine, which is why we decided to make this
+ /// particular lint `allow` by default.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = "Hello".to_owned();
+ /// x + ", World";
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub STRING_ADD,
+ restriction,
+ "using `x + ..` where x is a `String` instead of `push_str()`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the `as_bytes` method called on string literals
+ /// that contain only ASCII characters.
+ ///
+ /// ### Why is this bad?
+ /// Byte string literals (e.g., `b"foo"`) can be used
+ /// instead. They are shorter but less discoverable than `as_bytes()`.
+ ///
+ /// ### Known problems
+ /// `"str".as_bytes()` and the suggested replacement of `b"str"` are not
+ /// equivalent because they have different types. The former is `&[u8]`
+ /// while the latter is `&[u8; 3]`. That means in general they will have a
+ /// different set of methods and different trait implementations.
+ ///
+ /// ```compile_fail
+ /// fn f(v: Vec<u8>) {}
+ ///
+ /// f("...".as_bytes().to_owned()); // works
+ /// f(b"...".to_owned()); // does not work, because arg is [u8; 3] not Vec<u8>
+ ///
+ /// fn g(r: impl std::io::Read) {}
+ ///
+ /// g("...".as_bytes()); // works
+ /// g(b"..."); // does not work
+ /// ```
+ ///
+ /// The actual equivalent of `"str".as_bytes()` with the same type is not
+ /// `b"str"` but `&b"str"[..]`, which is a great deal of punctuation and not
+ /// more readable than a function call.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
- /// let bs = b"a byte string";
++ /// let bstr = "a byte string".as_bytes();
++ /// ```
+ ///
- /// let _ = std::str::from_utf8(&"Hello World!".as_bytes()[6..11]).unwrap();
++ /// Use instead:
++ /// ```rust
++ /// let bstr = b"a byte string";
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub STRING_LIT_AS_BYTES,
+ nursery,
+ "calling `as_bytes` on a string literal instead of using a byte string literal"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for slice operations on strings
+ ///
+ /// ### Why is this bad?
+ /// UTF-8 characters span multiple bytes, and it is easy to inadvertently confuse character
+ /// counts and string indices. This may lead to panics, and should warrant some test cases
+ /// containing wide UTF-8 characters. This lint is most useful in code that should avoid
+ /// panics at all costs.
+ ///
+ /// ### Known problems
+ /// Probably lots of false positives. If an index comes from a known valid position (e.g.
+ /// obtained via `char_indices` over the same string), it is totally OK.
+ ///
+ /// # Example
+ /// ```rust,should_panic
+ /// &"Ölkanne"[1..];
+ /// ```
+ #[clippy::version = "1.58.0"]
+ pub STRING_SLICE,
+ restriction,
+ "slicing a string"
+}
+
+declare_lint_pass!(StringAdd => [STRING_ADD, STRING_ADD_ASSIGN, STRING_SLICE]);
+
+impl<'tcx> LateLintPass<'tcx> for StringAdd {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ if in_external_macro(cx.sess(), e.span) {
+ return;
+ }
+ match e.kind {
+ ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Add, ..
+ },
+ left,
+ _,
+ ) => {
+ if is_string(cx, left) {
+ if !is_lint_allowed(cx, STRING_ADD_ASSIGN, e.hir_id) {
+ let parent = get_parent_expr(cx, e);
+ if let Some(p) = parent {
+ if let ExprKind::Assign(target, _, _) = p.kind {
+ // avoid duplicate matches
+ if SpanlessEq::new(cx).eq_expr(target, left) {
+ return;
+ }
+ }
+ }
+ }
+ span_lint(
+ cx,
+ STRING_ADD,
+ e.span,
+ "you added something to a string. Consider using `String::push_str()` instead",
+ );
+ }
+ },
+ ExprKind::Assign(target, src, _) => {
+ if is_string(cx, target) && is_add(cx, src, target) {
+ span_lint(
+ cx,
+ STRING_ADD_ASSIGN,
+ e.span,
+ "you assigned the result of adding something to this string. Consider using \
+ `String::push_str()` instead",
+ );
+ }
+ },
+ ExprKind::Index(target, _idx) => {
+ let e_ty = cx.typeck_results().expr_ty(target).peel_refs();
+ if matches!(e_ty.kind(), ty::Str) || is_type_diagnostic_item(cx, e_ty, sym::String) {
+ span_lint(
+ cx,
+ STRING_SLICE,
+ e.span,
+ "indexing into a string may panic if the index is within a UTF-8 character",
+ );
+ }
+ },
+ _ => {},
+ }
+ }
+}
+
+fn is_string(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
+ is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(e).peel_refs(), sym::String)
+}
+
+fn is_add(cx: &LateContext<'_>, src: &Expr<'_>, target: &Expr<'_>) -> bool {
+ match peel_blocks(src).kind {
+ ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Add, ..
+ },
+ left,
+ _,
+ ) => SpanlessEq::new(cx).eq_expr(target, left),
+ _ => false,
+ }
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Check if the string is transformed to byte array and casted back to string.
+ ///
+ /// ### Why is this bad?
+ /// It's unnecessary, the string can be used directly.
+ ///
+ /// ### Example
+ /// ```rust
- /// could be written as
++ /// std::str::from_utf8(&"Hello World!".as_bytes()[6..11]).unwrap();
+ /// ```
- /// let _ = &"Hello World!"[6..11];
++ ///
++ /// Use instead:
+ /// ```rust
++ /// &"Hello World!"[6..11];
+ /// ```
+ #[clippy::version = "1.50.0"]
+ pub STRING_FROM_UTF8_AS_BYTES,
+ complexity,
+ "casting string slices to byte slices and back"
+}
+
+// Max length a b"foo" string can take
+const MAX_LENGTH_BYTE_STRING_LIT: usize = 32;
+
+declare_lint_pass!(StringLitAsBytes => [STRING_LIT_AS_BYTES, STRING_FROM_UTF8_AS_BYTES]);
+
+impl<'tcx> LateLintPass<'tcx> for StringLitAsBytes {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ use rustc_ast::LitKind;
+
+ if_chain! {
+ // Find std::str::converts::from_utf8
+ if let Some(args) = match_function_call(cx, e, &paths::STR_FROM_UTF8);
+
+ // Find string::as_bytes
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, args) = args[0].kind;
+ if let ExprKind::Index(left, right) = args.kind;
+ let (method_names, expressions, _) = method_calls(left, 1);
+ if method_names.len() == 1;
+ if expressions.len() == 1;
+ if expressions[0].len() == 1;
+ if method_names[0] == sym!(as_bytes);
+
+ // Check for slicer
+ if let ExprKind::Struct(QPath::LangItem(LangItem::Range, ..), _, _) = right.kind;
+
+ then {
+ let mut applicability = Applicability::MachineApplicable;
+ let string_expression = &expressions[0][0];
+
+ let snippet_app = snippet_with_applicability(
+ cx,
+ string_expression.span, "..",
+ &mut applicability,
+ );
+
+ span_lint_and_sugg(
+ cx,
+ STRING_FROM_UTF8_AS_BYTES,
+ e.span,
+ "calling a slice of `as_bytes()` with `from_utf8` should be not necessary",
+ "try",
+ format!("Some(&{}[{}])", snippet_app, snippet(cx, right.span, "..")),
+ applicability
+ )
+ }
+ }
+
+ if_chain! {
+ if let ExprKind::MethodCall(path, args, _) = &e.kind;
+ if path.ident.name == sym!(as_bytes);
+ if let ExprKind::Lit(lit) = &args[0].kind;
+ if let LitKind::Str(lit_content, _) = &lit.node;
+ then {
+ let callsite = snippet(cx, args[0].span.source_callsite(), r#""foo""#);
+ let mut applicability = Applicability::MachineApplicable;
+ if callsite.starts_with("include_str!") {
+ span_lint_and_sugg(
+ cx,
+ STRING_LIT_AS_BYTES,
+ e.span,
+ "calling `as_bytes()` on `include_str!(..)`",
+ "consider using `include_bytes!(..)` instead",
+ snippet_with_applicability(cx, args[0].span, r#""foo""#, &mut applicability).replacen(
+ "include_str",
+ "include_bytes",
+ 1,
+ ),
+ applicability,
+ );
+ } else if lit_content.as_str().is_ascii()
+ && lit_content.as_str().len() <= MAX_LENGTH_BYTE_STRING_LIT
+ && !args[0].span.from_expansion()
+ {
+ span_lint_and_sugg(
+ cx,
+ STRING_LIT_AS_BYTES,
+ e.span,
+ "calling `as_bytes()` on a string literal",
+ "consider using a byte string literal instead",
+ format!(
+ "b{}",
+ snippet_with_applicability(cx, args[0].span, r#""foo""#, &mut applicability)
+ ),
+ applicability,
+ );
+ }
+ }
+ }
+
+ if_chain! {
+ if let ExprKind::MethodCall(path, [recv], _) = &e.kind;
+ if path.ident.name == sym!(into_bytes);
+ if let ExprKind::MethodCall(path, [recv], _) = &recv.kind;
+ if matches!(path.ident.name.as_str(), "to_owned" | "to_string");
+ if let ExprKind::Lit(lit) = &recv.kind;
+ if let LitKind::Str(lit_content, _) = &lit.node;
+
+ if lit_content.as_str().is_ascii();
+ if lit_content.as_str().len() <= MAX_LENGTH_BYTE_STRING_LIT;
+ if !recv.span.from_expansion();
+ then {
+ let mut applicability = Applicability::MachineApplicable;
+
+ span_lint_and_sugg(
+ cx,
+ STRING_LIT_AS_BYTES,
+ e.span,
+ "calling `into_bytes()` on a string literal",
+ "consider using a byte string literal instead",
+ format!(
+ "b{}.to_vec()",
+ snippet_with_applicability(cx, recv.span, r#""..""#, &mut applicability)
+ ),
+ applicability,
+ );
+ }
+ }
+ }
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint checks for `.to_string()` method calls on values of type `&str`.
+ ///
+ /// ### Why is this bad?
+ /// The `to_string` method is also used on other types to convert them to a string.
+ /// When called on a `&str` it turns the `&str` into the owned variant `String`, which can be better
+ /// expressed with `.to_owned()`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // example code where clippy issues a warning
+ /// let _ = "str".to_string();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// // example code which does not raise clippy warning
+ /// let _ = "str".to_owned();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub STR_TO_STRING,
+ restriction,
+ "using `to_string()` on a `&str`, which should be `to_owned()`"
+}
+
+declare_lint_pass!(StrToString => [STR_TO_STRING]);
+
+impl<'tcx> LateLintPass<'tcx> for StrToString {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::MethodCall(path, [self_arg, ..], _) = &expr.kind;
+ if path.ident.name == sym!(to_string);
+ let ty = cx.typeck_results().expr_ty(self_arg);
+ if let ty::Ref(_, ty, ..) = ty.kind();
+ if *ty.kind() == ty::Str;
+ then {
+ span_lint_and_help(
+ cx,
+ STR_TO_STRING,
+ expr.span,
+ "`to_string()` called on a `&str`",
+ None,
+ "consider using `.to_owned()`",
+ );
+ }
+ }
+ }
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint checks for `.to_string()` method calls on values of type `String`.
+ ///
+ /// ### Why is this bad?
+ /// The `to_string` method is also used on other types to convert them to a string.
+ /// When called on a `String` it only clones the `String`, which can be better expressed with `.clone()`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // example code where clippy issues a warning
+ /// let msg = String::from("Hello World");
+ /// let _ = msg.to_string();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// // example code which does not raise clippy warning
+ /// let msg = String::from("Hello World");
+ /// let _ = msg.clone();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub STRING_TO_STRING,
+ restriction,
+ "using `to_string()` on a `String`, which should be `clone()`"
+}
+
+declare_lint_pass!(StringToString => [STRING_TO_STRING]);
+
+impl<'tcx> LateLintPass<'tcx> for StringToString {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::MethodCall(path, [self_arg, ..], _) = &expr.kind;
+ if path.ident.name == sym!(to_string);
+ let ty = cx.typeck_results().expr_ty(self_arg);
+ if is_type_diagnostic_item(cx, ty, sym::String);
+ then {
+ span_lint_and_help(
+ cx,
+ STRING_TO_STRING,
+ expr.span,
+ "`to_string()` called on a `String`",
+ None,
+ "consider using `.clone()`",
+ );
+ }
+ }
+ }
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Warns about calling `str::trim` (or variants) before `str::split_whitespace`.
+ ///
+ /// ### Why is this bad?
+ /// `split_whitespace` already ignores leading and trailing whitespace.
+ ///
+ /// ### Example
+ /// ```rust
+ /// " A B C ".trim().split_whitespace();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// " A B C ".split_whitespace();
+ /// ```
+ #[clippy::version = "1.62.0"]
+ pub TRIM_SPLIT_WHITESPACE,
+ style,
+ "using `str::trim()` or alike before `str::split_whitespace`"
+}
+declare_lint_pass!(TrimSplitWhitespace => [TRIM_SPLIT_WHITESPACE]);
+
+impl<'tcx> LateLintPass<'tcx> for TrimSplitWhitespace {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &Expr<'_>) {
+ let tyckres = cx.typeck_results();
+ if_chain! {
+ if let ExprKind::MethodCall(path, [split_recv], split_ws_span) = expr.kind;
+ if path.ident.name == sym!(split_whitespace);
+ if let Some(split_ws_def_id) = tyckres.type_dependent_def_id(expr.hir_id);
+ if cx.tcx.is_diagnostic_item(sym::str_split_whitespace, split_ws_def_id);
+ if let ExprKind::MethodCall(path, [_trim_recv], trim_span) = split_recv.kind;
+ if let trim_fn_name @ ("trim" | "trim_start" | "trim_end") = path.ident.name.as_str();
+ if let Some(trim_def_id) = tyckres.type_dependent_def_id(split_recv.hir_id);
+ if is_one_of_trim_diagnostic_items(cx, trim_def_id);
+ then {
+ span_lint_and_sugg(
+ cx,
+ TRIM_SPLIT_WHITESPACE,
+ trim_span.with_hi(split_ws_span.lo()),
+ &format!("found call to `str::{}` before `str::split_whitespace`", trim_fn_name),
+ &format!("remove `{}()`", trim_fn_name),
+ String::new(),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ }
+}
+
+fn is_one_of_trim_diagnostic_items(cx: &LateContext<'_>, trim_def_id: DefId) -> bool {
+ cx.tcx.is_diagnostic_item(sym::str_trim, trim_def_id)
+ || cx.tcx.is_diagnostic_item(sym::str_trim_start, trim_def_id)
+ || cx.tcx.is_diagnostic_item(sym::str_trim_end, trim_def_id)
+}
--- /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 {}
+ /// ```
+ ///
++ /// Use instead:
+ /// ```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 {}
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// # mod hidden {
+ /// fn func<T: Clone + Default>(arg: T) {}
+ /// # }
+ ///
+ /// // 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
- diag.span_suggestion(
- e.span,
- "try",
- arg.as_ty(&to_ty.to_string()),
- Applicability::Unspecified,
- );
+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;
+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()) {
+ _ 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)) => {
+ // 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,
+ };
+
+ 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, 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()), Applicability::Unspecified);
+ }
+ },
+ );
+ true
+ },
+ _ => false,
+ }
+}
--- /dev/null
- /// Could be written as:
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::is_lint_allowed;
+use clippy_utils::source::snippet;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind, HirId};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use unicode_normalization::UnicodeNormalization;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for invisible Unicode characters in the code.
+ ///
+ /// ### Why is this bad?
+ /// Having an invisible character in the code makes for all
+ /// sorts of April fools, but otherwise is very much frowned upon.
+ ///
+ /// ### Example
+ /// You don't see it, but there may be a zero-width space or soft hyphen
+ /// somewhere in this text.
+ #[clippy::version = "1.49.0"]
+ pub INVISIBLE_CHARACTERS,
+ correctness,
+ "using an invisible character in a string literal, which is confusing"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for non-ASCII characters in string and char literals.
+ ///
+ /// ### Why is this bad?
+ /// Yeah, we know, the 90's called and wanted their charset
+ /// back. Even so, there still are editors and other programs out there that
+ /// don't work well with Unicode. So if the code is meant to be used
+ /// internationally, on multiple operating systems, or has other portability
+ /// requirements, activating this lint could be useful.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = String::from("€");
+ /// ```
++ ///
++ /// Use instead:
+ /// ```rust
+ /// let x = String::from("\u{20ac}");
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NON_ASCII_LITERAL,
+ restriction,
+ "using any literal non-ASCII chars in a string literal instead of using the `\\u` escape"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for string literals that contain Unicode in a form
+ /// that is not equal to its
+ /// [NFC-recomposition](http://www.unicode.org/reports/tr15/#Norm_Forms).
+ ///
+ /// ### Why is this bad?
+ /// If such a string is compared to another, the results
+ /// may be surprising.
+ ///
+ /// ### Example
+ /// You may not see it, but "à"" and "à"" aren't the same string. The
+ /// former when escaped is actually `"a\u{300}"` while the latter is `"\u{e0}"`.
+ #[clippy::version = "pre 1.29.0"]
+ pub UNICODE_NOT_NFC,
+ pedantic,
+ "using a Unicode literal not in NFC normal form (see [Unicode tr15](http://www.unicode.org/reports/tr15/) for further information)"
+}
+
+declare_lint_pass!(Unicode => [INVISIBLE_CHARACTERS, NON_ASCII_LITERAL, UNICODE_NOT_NFC]);
+
+impl LateLintPass<'_> for Unicode {
+ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'_ Expr<'_>) {
+ if let ExprKind::Lit(ref lit) = expr.kind {
+ if let LitKind::Str(_, _) | LitKind::Char(_) = lit.node {
+ check_str(cx, lit.span, expr.hir_id);
+ }
+ }
+ }
+}
+
+fn escape<T: Iterator<Item = char>>(s: T) -> String {
+ let mut result = String::new();
+ for c in s {
+ if c as u32 > 0x7F {
+ for d in c.escape_unicode() {
+ result.push(d);
+ }
+ } else {
+ result.push(c);
+ }
+ }
+ result
+}
+
+fn check_str(cx: &LateContext<'_>, span: Span, id: HirId) {
+ let string = snippet(cx, span, "");
+ if string.chars().any(|c| ['\u{200B}', '\u{ad}', '\u{2060}'].contains(&c)) {
+ span_lint_and_sugg(
+ cx,
+ INVISIBLE_CHARACTERS,
+ span,
+ "invisible character detected",
+ "consider replacing the string with",
+ string
+ .replace('\u{200B}', "\\u{200B}")
+ .replace('\u{ad}', "\\u{AD}")
+ .replace('\u{2060}', "\\u{2060}"),
+ Applicability::MachineApplicable,
+ );
+ }
+ if string.chars().any(|c| c as u32 > 0x7F) {
+ span_lint_and_sugg(
+ cx,
+ NON_ASCII_LITERAL,
+ span,
+ "literal non-ASCII character detected",
+ "consider replacing the string with",
+ if is_lint_allowed(cx, UNICODE_NOT_NFC, id) {
+ escape(string.chars())
+ } else {
+ escape(string.nfc())
+ },
+ Applicability::MachineApplicable,
+ );
+ }
+ if is_lint_allowed(cx, NON_ASCII_LITERAL, id) && string.chars().zip(string.nfc()).any(|(a, b)| a != b) {
+ span_lint_and_sugg(
+ cx,
+ UNICODE_NOT_NFC,
+ span,
+ "non-NFC Unicode sequence detected",
+ "consider replacing the string with",
+ string.nfc().collect::<String>(),
+ Applicability::MachineApplicable,
+ );
+ }
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::span_lint_and_help;
+use rustc_hir::intravisit::{walk_expr, walk_fn, FnKind, Visitor};
+use rustc_hir::{Body, Expr, ExprKind, FnDecl, FnHeader, HirId, IsAsync, YieldSource};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::nested_filter;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::Span;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for functions that are declared `async` but have no `.await`s inside of them.
+ ///
+ /// ### Why is this bad?
+ /// Async functions with no async code create overhead, both mentally and computationally.
+ /// Callers of async methods either need to be calling from an async function themselves or run it on an executor, both of which
+ /// causes runtime overhead and hassle for the caller.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// async fn get_random_number() -> i64 {
+ /// 4 // Chosen by fair dice roll. Guaranteed to be random.
+ /// }
+ /// let number_future = get_random_number();
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
+ /// fn get_random_number_improved() -> i64 {
+ /// 4 // Chosen by fair dice roll. Guaranteed to be random.
+ /// }
+ /// let number_future = async { get_random_number_improved() };
+ /// ```
+ #[clippy::version = "1.54.0"]
+ pub UNUSED_ASYNC,
+ pedantic,
+ "finds async functions with no await statements"
+}
+
+declare_lint_pass!(UnusedAsync => [UNUSED_ASYNC]);
+
+struct AsyncFnVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ found_await: bool,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for AsyncFnVisitor<'a, 'tcx> {
+ type NestedFilter = nested_filter::OnlyBodies;
+
+ fn visit_expr(&mut self, ex: &'tcx Expr<'tcx>) {
+ if let ExprKind::Yield(_, YieldSource::Await { .. }) = ex.kind {
+ self.found_await = true;
+ }
+ walk_expr(self, ex);
+ }
+
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
+ }
+}
+
+impl<'tcx> LateLintPass<'tcx> for UnusedAsync {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'tcx>,
+ fn_kind: FnKind<'tcx>,
+ fn_decl: &'tcx FnDecl<'tcx>,
+ body: &Body<'tcx>,
+ span: Span,
+ hir_id: HirId,
+ ) {
+ if let FnKind::ItemFn(_, _, FnHeader { asyncness, .. }) = &fn_kind {
+ if matches!(asyncness, IsAsync::Async) {
+ let mut visitor = AsyncFnVisitor { cx, found_await: false };
+ walk_fn(&mut visitor, fn_kind, fn_decl, body.id(), span, hir_id);
+ if !visitor.found_await {
+ span_lint_and_help(
+ cx,
+ UNUSED_ASYNC,
+ span,
+ "unused `async` for function with no await statements",
+ None,
+ "consider removing the `async` from this function",
+ );
+ }
+ }
+ }
+ }
+}
--- /dev/null
- /// // Bad
+use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
+use clippy_utils::source::{snippet, snippet_with_macro_callsite};
+use clippy_utils::sugg::Sugg;
+use clippy_utils::ty::{is_type_diagnostic_item, same_type_and_consts};
+use clippy_utils::{get_parent_expr, is_trait_method, match_def_path, paths};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind, HirId, MatchSource};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `Into`, `TryInto`, `From`, `TryFrom`, or `IntoIter` calls
+ /// which uselessly convert to the same type.
+ ///
+ /// ### Why is this bad?
+ /// Redundant code.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// // format!() returns a `String`
+ /// let s: String = format!("hello").into();
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
+ /// let s: String = format!("hello");
+ /// ```
+ #[clippy::version = "1.45.0"]
+ pub USELESS_CONVERSION,
+ complexity,
+ "calls to `Into`, `TryInto`, `From`, `TryFrom`, or `IntoIter` which perform useless conversions to the same type"
+}
+
+#[derive(Default)]
+pub struct UselessConversion {
+ try_desugar_arm: Vec<HirId>,
+}
+
+impl_lint_pass!(UselessConversion => [USELESS_CONVERSION]);
+
+#[expect(clippy::too_many_lines)]
+impl<'tcx> LateLintPass<'tcx> for UselessConversion {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ if e.span.from_expansion() {
+ return;
+ }
+
+ if Some(&e.hir_id) == self.try_desugar_arm.last() {
+ return;
+ }
+
+ match e.kind {
+ ExprKind::Match(_, arms, MatchSource::TryDesugar) => {
+ let e = match arms[0].body.kind {
+ ExprKind::Ret(Some(e)) | ExprKind::Break(_, Some(e)) => e,
+ _ => return,
+ };
+ if let ExprKind::Call(_, args) = e.kind {
+ self.try_desugar_arm.push(args[0].hir_id);
+ }
+ },
+
+ ExprKind::MethodCall(name, .., args, _) => {
+ if is_trait_method(cx, e, sym::Into) && name.ident.as_str() == "into" {
+ let a = cx.typeck_results().expr_ty(e);
+ let b = cx.typeck_results().expr_ty(&args[0]);
+ if same_type_and_consts(a, b) {
+ let sugg = snippet_with_macro_callsite(cx, args[0].span, "<expr>").to_string();
+ span_lint_and_sugg(
+ cx,
+ USELESS_CONVERSION,
+ e.span,
+ &format!("useless conversion to the same type: `{}`", b),
+ "consider removing `.into()`",
+ sugg,
+ Applicability::MachineApplicable, // snippet
+ );
+ }
+ }
+ if is_trait_method(cx, e, sym::IntoIterator) && name.ident.name == sym::into_iter {
+ if let Some(parent_expr) = get_parent_expr(cx, e) {
+ if let ExprKind::MethodCall(parent_name, ..) = parent_expr.kind {
+ if parent_name.ident.name != sym::into_iter {
+ return;
+ }
+ }
+ }
+ let a = cx.typeck_results().expr_ty(e);
+ let b = cx.typeck_results().expr_ty(&args[0]);
+ if same_type_and_consts(a, b) {
+ let sugg = snippet(cx, args[0].span, "<expr>").into_owned();
+ span_lint_and_sugg(
+ cx,
+ USELESS_CONVERSION,
+ e.span,
+ &format!("useless conversion to the same type: `{}`", b),
+ "consider removing `.into_iter()`",
+ sugg,
+ Applicability::MachineApplicable, // snippet
+ );
+ }
+ }
+ if_chain! {
+ if is_trait_method(cx, e, sym::TryInto) && name.ident.name == sym::try_into;
+ let a = cx.typeck_results().expr_ty(e);
+ let b = cx.typeck_results().expr_ty(&args[0]);
+ if is_type_diagnostic_item(cx, a, sym::Result);
+ if let ty::Adt(_, substs) = a.kind();
+ if let Some(a_type) = substs.types().next();
+ if same_type_and_consts(a_type, b);
+
+ then {
+ span_lint_and_help(
+ cx,
+ USELESS_CONVERSION,
+ e.span,
+ &format!("useless conversion to the same type: `{}`", b),
+ None,
+ "consider removing `.try_into()`",
+ );
+ }
+ }
+ },
+
+ ExprKind::Call(path, args) => {
+ if_chain! {
+ if args.len() == 1;
+ if let ExprKind::Path(ref qpath) = path.kind;
+ if let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id();
+ then {
+ let a = cx.typeck_results().expr_ty(e);
+ let b = cx.typeck_results().expr_ty(&args[0]);
+ if_chain! {
+ if match_def_path(cx, def_id, &paths::TRY_FROM);
+ if is_type_diagnostic_item(cx, a, sym::Result);
+ if let ty::Adt(_, substs) = a.kind();
+ if let Some(a_type) = substs.types().next();
+ if same_type_and_consts(a_type, b);
+
+ then {
+ let hint = format!("consider removing `{}()`", snippet(cx, path.span, "TryFrom::try_from"));
+ span_lint_and_help(
+ cx,
+ USELESS_CONVERSION,
+ e.span,
+ &format!("useless conversion to the same type: `{}`", b),
+ None,
+ &hint,
+ );
+ }
+ }
+
+ if_chain! {
+ if match_def_path(cx, def_id, &paths::FROM_FROM);
+ if same_type_and_consts(a, b);
+
+ then {
+ let sugg = Sugg::hir_with_macro_callsite(cx, &args[0], "<expr>").maybe_par();
+ let sugg_msg =
+ format!("consider removing `{}()`", snippet(cx, path.span, "From::from"));
+ span_lint_and_sugg(
+ cx,
+ USELESS_CONVERSION,
+ e.span,
+ &format!("useless conversion to the same type: `{}`", b),
+ &sugg_msg,
+ sugg.to_string(),
+ Applicability::MachineApplicable, // snippet
+ );
+ }
+ }
+ }
+ }
+ },
+
+ _ => {},
+ }
+ }
+
+ fn check_expr_post(&mut self, _: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+ if Some(&e.hir_id) == self.try_desugar_arm.last() {
+ self.try_desugar_arm.pop();
+ }
+ }
+}
--- /dev/null
- /// 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()),
+//! 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};
+
++#[rustfmt::skip]
++const DEFAULT_DOC_VALID_IDENTS: &[&str] = &[
++ "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",
++];
++const DEFAULT_BLACKLISTED_NAMES: &[&str] = &["foo", "baz", "quux"];
++
+/// 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 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()),
++ /// The list of blacklisted names to lint about. NB: `bar` is not here since it has legitimate uses. The value
++ /// `".."` can be used as part of the list to indicate, that the configured values should be appended to the
++ /// default configuration of Clippy. By default any configuraction will replace the default value.
++ (blacklisted_names: Vec<String> = super::DEFAULT_BLACKLISTED_NAMES.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.
+ ///
- toml::from_str(&content).unwrap_or_else(TryConf::from_error)
++ /// The list of words this lint should not consider as identifiers needing ticks. The value
++ /// `".."` can be used as part of the list to indicate, that the configured values should be appended to the
++ /// default configuration of Clippy. By default any configuraction will replace the default value. For example:
++ /// * `doc-valid-idents = ["ClipPy"]` would replace the default list with `["ClipPy"]`.
++ /// * `doc-valid-idents = ["ClipPy", ".."]` would append `ClipPy` to the default list.
++ ///
++ /// Default list:
++ (doc_valid_idents: Vec<String> = super::DEFAULT_DOC_VALID_IDENTS.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,
+ };
++ match toml::from_str::<TryConf>(&content) {
++ Ok(mut conf) => {
++ extend_vec_if_indicator_present(&mut conf.conf.doc_valid_idents, DEFAULT_DOC_VALID_IDENTS);
++ extend_vec_if_indicator_present(&mut conf.conf.blacklisted_names, DEFAULT_BLACKLISTED_NAMES);
++
++ conf
++ },
++ Err(e) => TryConf::from_error(e),
++ }
++}
++
++fn extend_vec_if_indicator_present(vec: &mut Vec<String>, default: &[&str]) {
++ if vec.contains(&"..".to_string()) {
++ vec.extend(default.iter().map(ToString::to_string));
++ }
+}
+
+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
- /// Bad:
+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
- /// Good:
+ /// ```rust,ignore
+ /// cx.span_lint(LINT_NAME, "message");
+ /// ```
+ ///
- /// Bad:
++ /// Use instead:
+ /// ```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
- /// Good:
+ /// ```rust,ignore
+ /// expr.span.ctxt().outer().expn_data()
+ /// ```
+ ///
- /// Bad:
++ /// Use instead:
+ /// ```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
- /// Good:
+ /// ```rust,ignore
+ /// declare_lint! { pub COOL_LINT, nursery, "default lint description" }
+ /// ```
+ ///
- /// Bad:
++ /// Use instead:
+ /// ```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
- /// Good:
+ /// ```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);
+ /// });
+ /// ```
+ ///
- /// Bad:
++ /// Use instead:
+ /// ```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
- /// Good:
+ /// ```rust,ignore
+ /// utils::match_type(cx, ty, &paths::VEC)
+ /// ```
+ ///
- /// Bad:
++ /// Use instead:
+ /// ```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
- /// Good:
+ /// ```rust,ignore
+ /// let _ = sym!(f32);
+ /// ```
+ ///
- /// Bad:
++ /// Use instead:
+ /// ```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
- /// Good:
+ /// ```rust,ignore
+ /// symbol.as_str() == "clippy";
+ /// ```
+ ///
- if let ExprKind::Closure(_, _, body_id, _, _) = &and_then_args[4].kind;
- let body = cx.tcx.hir().body(*body_id);
++ /// Use instead:
+ /// ```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!(
+ 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 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;
+ 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, .. } = &and_then_args[4].kind;
++ let body = cx.tcx.hir().body(*body);
+ 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
- collect_renames(&mut lints);
+//! 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;
++use std::path::PathBuf;
++use std::process::Command;
+
+/// 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>,
++ clippy_project_root: PathBuf,
+}
+
+impl MetadataCollector {
+ pub fn new() -> Self {
+ Self {
+ lints: BinaryHeap::<LintMetadata>::default(),
+ applicability_info: FxHashMap::<String, ApplicabilityInfo>::default(),
+ config: collect_configs(),
++ clippy_project_root: clippy_dev::clippy_project_root(),
+ }
+ }
+
+ 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();
- impl std::fmt::Display for SerializableSpan {
- fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ for x in &mut lints {
+ x.applicability = Some(applicability_info.remove(&x.id).unwrap_or_default());
++ replace_produces(&x.id, &mut x.docs, &self.clippy_project_root);
+ }
+
++ collect_renames(&mut lints);
++
+ // 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,
+ }
+ }
+}
+
++fn replace_produces(lint_name: &str, docs: &mut String, clippy_project_root: &Path) {
++ let mut doc_lines = docs.lines().map(ToString::to_string).collect::<Vec<_>>();
++ let mut lines = doc_lines.iter_mut();
++
++ 'outer: loop {
++ // Find the start of the example
++
++ // ```rust
++ loop {
++ match lines.next() {
++ Some(line) if line.trim_start().starts_with("```rust") => {
++ if line.contains("ignore") || line.contains("no_run") {
++ // A {{produces}} marker may have been put on a ignored code block by mistake,
++ // just seek to the end of the code block and continue checking.
++ if lines.any(|line| line.trim_start().starts_with("```")) {
++ continue;
++ }
++
++ panic!("lint `{}` has an unterminated code block", lint_name)
++ }
++
++ break;
++ },
++ Some(line) if line.trim_start() == "{{produces}}" => {
++ panic!(
++ "lint `{}` has marker {{{{produces}}}} with an ignored or missing code block",
++ lint_name
++ )
++ },
++ Some(line) => {
++ let line = line.trim();
++ // These are the two most common markers of the corrections section
++ if line.eq_ignore_ascii_case("Use instead:") || line.eq_ignore_ascii_case("Could be written as:") {
++ break 'outer;
++ }
++ },
++ None => break 'outer,
++ }
++ }
++
++ // Collect the example
++ let mut example = Vec::new();
++ loop {
++ match lines.next() {
++ Some(line) if line.trim_start() == "```" => break,
++ Some(line) => example.push(line),
++ None => panic!("lint `{}` has an unterminated code block", lint_name),
++ }
++ }
++
++ // Find the {{produces}} and attempt to generate the output
++ loop {
++ match lines.next() {
++ Some(line) if line.is_empty() => {},
++ Some(line) if line.trim() == "{{produces}}" => {
++ let output = get_lint_output(lint_name, &example, clippy_project_root);
++ line.replace_range(
++ ..,
++ &format!(
++ "<details>\
++ <summary>Produces</summary>\n\
++ \n\
++ ```text\n\
++ {}\n\
++ ```\n\
++ </details>",
++ output
++ ),
++ );
++
++ break;
++ },
++ // No {{produces}}, we can move on to the next example
++ Some(_) => break,
++ None => break 'outer,
++ }
++ }
++ }
++
++ *docs = cleanup_docs(&doc_lines);
++}
++
++fn get_lint_output(lint_name: &str, example: &[&mut String], clippy_project_root: &Path) -> String {
++ let dir = tempfile::tempdir().unwrap_or_else(|e| panic!("failed to create temp dir: {e}"));
++ let file = dir.path().join("lint_example.rs");
++
++ let mut source = String::new();
++ let unhidden = example
++ .iter()
++ .map(|line| line.trim_start().strip_prefix("# ").unwrap_or(line));
++
++ // Get any attributes
++ let mut lines = unhidden.peekable();
++ while let Some(line) = lines.peek() {
++ if line.starts_with("#!") {
++ source.push_str(line);
++ source.push('\n');
++ lines.next();
++ } else {
++ break;
++ }
++ }
++
++ let needs_main = !example.iter().any(|line| line.contains("fn main"));
++ if needs_main {
++ source.push_str("fn main() {\n");
++ }
++
++ for line in lines {
++ source.push_str(line);
++ source.push('\n');
++ }
++
++ if needs_main {
++ source.push_str("}\n");
++ }
++
++ if let Err(e) = fs::write(&file, &source) {
++ panic!("failed to write to `{}`: {e}", file.as_path().to_string_lossy());
++ }
++
++ let prefixed_name = format!("{}{lint_name}", CLIPPY_LINT_GROUP_PREFIX);
++
++ let mut cmd = Command::new("cargo");
++
++ cmd.current_dir(clippy_project_root)
++ .env("CARGO_INCREMENTAL", "0")
++ .env("CLIPPY_ARGS", "")
++ .env("CLIPPY_DISABLE_DOCS_LINKS", "1")
++ // We need to disable this to enable all lints
++ .env("ENABLE_METADATA_COLLECTION", "0")
++ .args(["run", "--bin", "clippy-driver"])
++ .args(["--target-dir", "./clippy_lints/target"])
++ .args(["--", "--error-format=json"])
++ .args(["--edition", "2021"])
++ .arg("-Cdebuginfo=0")
++ .args(["-A", "clippy::all"])
++ .args(["-W", &prefixed_name])
++ .args(["-L", "./target/debug"])
++ .args(["-Z", "no-codegen"]);
++
++ let output = cmd
++ .arg(file.as_path())
++ .output()
++ .unwrap_or_else(|e| panic!("failed to run `{:?}`: {e}", cmd));
++
++ let tmp_file_path = file.to_string_lossy();
++ let stderr = std::str::from_utf8(&output.stderr).unwrap();
++ let msgs = stderr
++ .lines()
++ .filter(|line| line.starts_with('{'))
++ .map(|line| serde_json::from_str(line).unwrap())
++ .collect::<Vec<serde_json::Value>>();
++
++ let mut rendered = String::new();
++ let iter = msgs
++ .iter()
++ .filter(|msg| matches!(&msg["code"]["code"], serde_json::Value::String(s) if s == &prefixed_name));
++
++ for message in iter {
++ let rendered_part = message["rendered"].as_str().expect("rendered field should exist");
++ rendered.push_str(rendered_part);
++ }
++
++ if rendered.is_empty() {
++ let rendered: Vec<&str> = msgs.iter().filter_map(|msg| msg["rendered"].as_str()).collect();
++ let non_json: Vec<&str> = stderr.lines().filter(|line| !line.starts_with('{')).collect();
++ panic!(
++ "did not find lint `{}` in output of example, got:\n{}\n{}",
++ lint_name,
++ non_json.join("\n"),
++ rendered.join("\n")
++ );
++ }
++
++ // The reader doesn't need to see `/tmp/.tmpfiy2Qd/lint_example.rs` :)
++ rendered.trim_end().replace(&*tmp_file_path, "lint_example.rs")
++}
++
+#[derive(Debug, Clone, Serialize, PartialEq, Eq, PartialOrd, Ord)]
+struct SerializableSpan {
+ path: String,
+ line: usize,
+}
+
- if let Some(mut docs) = extract_attr_docs_or_lint(cx, item);
++impl fmt::Display for SerializableSpan {
++ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> 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);
- docs.push_str(&configuration_section);
++ if let Some(mut raw_docs) = extract_attr_docs_or_lint(cx, item);
+ then {
+ if let Some(configuration_section) = self.get_lint_configs(&lint_name) {
- docs,
++ raw_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,
- if let Some(docs) = extract_attr_docs_or_lint(cx, item);
++ raw_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
- docs,
++ if let Some(raw_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,
- ///
- /// ---
- ///
++ raw_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`
- 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 mut docs = String::from(lines.next()?.as_str());
++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);
++
++ if let Some(line) = lines.next() {
++ let raw_docs = lines.fold(String::from(line.as_str()) + "\n", |s, line| s + line.as_str() + "\n");
++ return Some(raw_docs);
++ }
++
++ None
++}
++
+/// 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
- for line in lines {
- let line = line.as_str();
++fn cleanup_docs(docs_collection: &Vec<String>) -> String {
+ let mut in_code_block = false;
+ let mut is_code_block_rust = false;
- Some(docs)
+
++ let mut docs = String::new();
++ for line in docs_collection {
+ // 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);
+ }
+ }
- if let ExprKind::Closure(_, _, body_id, _, _) = closure_expr.kind {
++
++ 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 {
- intravisit::walk_body(&mut scanner, cx.tcx.hir().body(body_id));
++ if let ExprKind::Closure { body, .. } = closure_expr.kind {
+ let mut scanner = IsMultiSpanScanner::new(cx);
++ intravisit::walk_body(&mut scanner, cx.tcx.hir().body(body));
+ 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
- /// # fn foo(my_vec: &[u8]) {}
+use clippy_utils::consts::{constant, Constant};
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::higher;
+use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::ty::is_copy;
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::layout::LayoutOf;
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+
+#[expect(clippy::module_name_repetitions)]
+#[derive(Copy, Clone)]
+pub struct UselessVec {
+ pub too_large_for_stack: u64,
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `&vec![..]` when using `&[..]` would
+ /// be possible.
+ ///
+ /// ### Why is this bad?
+ /// This is less efficient.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Bad
++ /// fn foo(_x: &[u8]) {}
+ ///
- /// // Good
+ /// foo(&vec![1, 2]);
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # fn foo(_x: &[u8]) {}
+ /// foo(&[1, 2]);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub USELESS_VEC,
+ perf,
+ "useless `vec!`"
+}
+
+impl_lint_pass!(UselessVec => [USELESS_VEC]);
+
+impl<'tcx> LateLintPass<'tcx> for UselessVec {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ // search for `&vec![_]` expressions where the adjusted type is `&[_]`
+ if_chain! {
+ if let ty::Ref(_, ty, _) = cx.typeck_results().expr_ty_adjusted(expr).kind();
+ if let ty::Slice(..) = ty.kind();
+ if let ExprKind::AddrOf(BorrowKind::Ref, mutability, addressee) = expr.kind;
+ if let Some(vec_args) = higher::VecArgs::hir(cx, addressee);
+ then {
+ self.check_vec_macro(cx, &vec_args, mutability, expr.span);
+ }
+ }
+
+ // search for `for _ in vec![…]`
+ if_chain! {
+ if let Some(higher::ForLoop { arg, .. }) = higher::ForLoop::hir(expr);
+ if let Some(vec_args) = higher::VecArgs::hir(cx, arg);
+ if is_copy(cx, vec_type(cx.typeck_results().expr_ty_adjusted(arg)));
+ then {
+ // report the error around the `vec!` not inside `<std macros>:`
+ let span = arg.span.ctxt().outer_expn_data().call_site;
+ self.check_vec_macro(cx, &vec_args, Mutability::Not, span);
+ }
+ }
+ }
+}
+
+impl UselessVec {
+ fn check_vec_macro<'tcx>(
+ self,
+ cx: &LateContext<'tcx>,
+ vec_args: &higher::VecArgs<'tcx>,
+ mutability: Mutability,
+ span: Span,
+ ) {
+ let mut applicability = Applicability::MachineApplicable;
+ let snippet = match *vec_args {
+ higher::VecArgs::Repeat(elem, len) => {
+ if let Some((Constant::Int(len_constant), _)) = constant(cx, cx.typeck_results(), len) {
+ #[expect(clippy::cast_possible_truncation)]
+ if len_constant as u64 * size_of(cx, elem) > self.too_large_for_stack {
+ return;
+ }
+
+ match mutability {
+ Mutability::Mut => {
+ format!(
+ "&mut [{}; {}]",
+ snippet_with_applicability(cx, elem.span, "elem", &mut applicability),
+ snippet_with_applicability(cx, len.span, "len", &mut applicability)
+ )
+ },
+ Mutability::Not => {
+ format!(
+ "&[{}; {}]",
+ snippet_with_applicability(cx, elem.span, "elem", &mut applicability),
+ snippet_with_applicability(cx, len.span, "len", &mut applicability)
+ )
+ },
+ }
+ } else {
+ return;
+ }
+ },
+ higher::VecArgs::Vec(args) => {
+ if let Some(last) = args.iter().last() {
+ if args.len() as u64 * size_of(cx, last) > self.too_large_for_stack {
+ return;
+ }
+ let span = args[0].span.to(last.span);
+
+ match mutability {
+ Mutability::Mut => {
+ format!(
+ "&mut [{}]",
+ snippet_with_applicability(cx, span, "..", &mut applicability)
+ )
+ },
+ Mutability::Not => {
+ format!("&[{}]", snippet_with_applicability(cx, span, "..", &mut applicability))
+ },
+ }
+ } else {
+ match mutability {
+ Mutability::Mut => "&mut []".into(),
+ Mutability::Not => "&[]".into(),
+ }
+ }
+ },
+ };
+
+ span_lint_and_sugg(
+ cx,
+ USELESS_VEC,
+ span,
+ "useless use of `vec!`",
+ "you can use a slice directly",
+ snippet,
+ applicability,
+ );
+ }
+}
+
+fn size_of(cx: &LateContext<'_>, expr: &Expr<'_>) -> u64 {
+ let ty = cx.typeck_results().expr_ty_adjusted(expr);
+ cx.layout_of(ty).map_or(0, |l| l.size.bytes())
+}
+
+/// Returns the item type of the vector (i.e., the `T` in `Vec<T>`).
+fn vec_type(ty: Ty<'_>) -> Ty<'_> {
+ if let ty::Adt(_, substs) = ty.kind() {
+ substs.type_at(0)
+ } else {
+ panic!("The type of `vec!` is a not a struct?");
+ }
+}
--- /dev/null
- /// ```rust,ignore
- /// // Bad
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::is_test_module_or_function;
+use clippy_utils::source::{snippet, snippet_with_applicability};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{
+ def::{DefKind, Res},
+ Item, ItemKind, PathSegment, UseKind,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::symbol::kw;
+use rustc_span::{sym, BytePos};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `use Enum::*`.
+ ///
+ /// ### Why is this bad?
+ /// It is usually better style to use the prefixed name of
+ /// an enumeration variant, rather than importing variants.
+ ///
+ /// ### Known problems
+ /// Old-style enumerations that prefix the variants are
+ /// still around.
+ ///
+ /// ### Example
- /// // Good
++ /// ```rust
+ /// use std::cmp::Ordering::*;
++ ///
++ /// # fn foo(_: std::cmp::Ordering) {}
+ /// foo(Less);
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
+ /// use std::cmp::Ordering;
++ ///
++ /// # fn foo(_: Ordering) {}
+ /// foo(Ordering::Less)
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ENUM_GLOB_USE,
+ pedantic,
+ "use items that import all variants of an enum"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for wildcard imports `use _::*`.
+ ///
+ /// ### Why is this bad?
+ /// wildcard imports can pollute the namespace. This is especially bad if
+ /// you try to import something through a wildcard, that already has been imported by name from
+ /// a different source:
+ ///
+ /// ```rust,ignore
+ /// use crate1::foo; // Imports a function named foo
+ /// use crate2::*; // Has a function named foo
+ ///
+ /// foo(); // Calls crate1::foo
+ /// ```
+ ///
+ /// This can lead to confusing error messages at best and to unexpected behavior at worst.
+ ///
+ /// ### Exceptions
+ /// Wildcard imports are allowed from modules named `prelude`. Many crates (including the standard library)
+ /// provide modules named "prelude" specifically designed for wildcard import.
+ ///
+ /// `use super::*` is allowed in test modules. This is defined as any module with "test" in the name.
+ ///
+ /// These exceptions can be disabled using the `warn-on-all-wildcard-imports` configuration flag.
+ ///
+ /// ### Known problems
+ /// If macros are imported through the wildcard, this macro is not included
+ /// by the suggestion and has to be added by hand.
+ ///
+ /// Applying the suggestion when explicit imports of the things imported with a glob import
+ /// exist, may result in `unused_imports` warnings.
+ ///
+ /// ### Example
+ /// ```rust,ignore
- /// // Good
+ /// use crate1::*;
+ ///
+ /// foo();
+ /// ```
+ ///
++ /// Use instead:
+ /// ```rust,ignore
+ /// use crate1::foo;
+ ///
+ /// foo();
+ /// ```
+ #[clippy::version = "1.43.0"]
+ pub WILDCARD_IMPORTS,
+ pedantic,
+ "lint `use _::*` statements"
+}
+
+#[derive(Default)]
+pub struct WildcardImports {
+ warn_on_all: bool,
+ test_modules_deep: u32,
+}
+
+impl WildcardImports {
+ pub fn new(warn_on_all: bool) -> Self {
+ Self {
+ warn_on_all,
+ test_modules_deep: 0,
+ }
+ }
+}
+
+impl_lint_pass!(WildcardImports => [ENUM_GLOB_USE, WILDCARD_IMPORTS]);
+
+impl LateLintPass<'_> for WildcardImports {
+ fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
+ if is_test_module_or_function(cx.tcx, item) {
+ self.test_modules_deep = self.test_modules_deep.saturating_add(1);
+ }
+ let module = cx.tcx.parent_module_from_def_id(item.def_id);
+ if cx.tcx.visibility(item.def_id) != ty::Visibility::Restricted(module.to_def_id()) {
+ return;
+ }
+ if_chain! {
+ if let ItemKind::Use(use_path, UseKind::Glob) = &item.kind;
+ if self.warn_on_all || !self.check_exceptions(item, use_path.segments);
+ let used_imports = cx.tcx.names_imported_by_glob_use(item.def_id);
+ if !used_imports.is_empty(); // Already handled by `unused_imports`
+ then {
+ let mut applicability = Applicability::MachineApplicable;
+ let import_source_snippet = snippet_with_applicability(cx, use_path.span, "..", &mut applicability);
+ let (span, braced_glob) = if import_source_snippet.is_empty() {
+ // This is a `_::{_, *}` import
+ // In this case `use_path.span` is empty and ends directly in front of the `*`,
+ // so we need to extend it by one byte.
+ (
+ use_path.span.with_hi(use_path.span.hi() + BytePos(1)),
+ true,
+ )
+ } else {
+ // In this case, the `use_path.span` ends right before the `::*`, so we need to
+ // extend it up to the `*`. Since it is hard to find the `*` in weird
+ // formattings like `use _ :: *;`, we extend it up to, but not including the
+ // `;`. In nested imports, like `use _::{inner::*, _}` there is no `;` and we
+ // can just use the end of the item span
+ let mut span = use_path.span.with_hi(item.span.hi());
+ if snippet(cx, span, "").ends_with(';') {
+ span = use_path.span.with_hi(item.span.hi() - BytePos(1));
+ }
+ (
+ span, false,
+ )
+ };
+
+ let imports_string = if used_imports.len() == 1 {
+ used_imports.iter().next().unwrap().to_string()
+ } else {
+ let mut imports = used_imports
+ .iter()
+ .map(ToString::to_string)
+ .collect::<Vec<_>>();
+ imports.sort();
+ if braced_glob {
+ imports.join(", ")
+ } else {
+ format!("{{{}}}", imports.join(", "))
+ }
+ };
+
+ let sugg = if braced_glob {
+ imports_string
+ } else {
+ format!("{}::{}", import_source_snippet, imports_string)
+ };
+
+ let (lint, message) = if let Res::Def(DefKind::Enum, _) = use_path.res {
+ (ENUM_GLOB_USE, "usage of wildcard import for enum variants")
+ } else {
+ (WILDCARD_IMPORTS, "usage of wildcard import")
+ };
+
+ span_lint_and_sugg(
+ cx,
+ lint,
+ span,
+ message,
+ "try",
+ sugg,
+ applicability,
+ );
+ }
+ }
+ }
+
+ fn check_item_post(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
+ if is_test_module_or_function(cx.tcx, item) {
+ self.test_modules_deep = self.test_modules_deep.saturating_sub(1);
+ }
+ }
+}
+
+impl WildcardImports {
+ fn check_exceptions(&self, item: &Item<'_>, segments: &[PathSegment<'_>]) -> bool {
+ item.span.from_expansion()
+ || is_prelude_import(segments)
+ || (is_super_only_import(segments) && self.test_modules_deep > 0)
+ }
+}
+
+// Allow "...prelude::..::*" imports.
+// Many crates have a prelude, and it is imported as a glob by design.
+fn is_prelude_import(segments: &[PathSegment<'_>]) -> bool {
+ segments.iter().any(|ps| ps.ident.name == sym::prelude)
+}
+
+// Allow "super::*" imports in tests.
+fn is_super_only_import(segments: &[PathSegment<'_>]) -> bool {
+ segments.len() == 1 && segments[0].ident.name == kw::Super
+}
--- /dev/null
- /// // Bad
+use std::borrow::Cow;
+use std::iter;
+use std::ops::{Deref, Range};
+
+use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::source::{snippet_opt, snippet_with_applicability};
+use rustc_ast::ast::{Expr, ExprKind, Impl, Item, ItemKind, MacCall, Path, StrLit, StrStyle};
+use rustc_ast::token::{self, LitKind};
+use rustc_ast::tokenstream::TokenStream;
+use rustc_errors::{Applicability, DiagnosticBuilder};
+use rustc_lexer::unescape::{self, EscapeError};
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_parse::parser;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::symbol::{kw, Symbol};
+use rustc_span::{sym, BytePos, InnerSpan, Span, DUMMY_SP};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint warns when you use `println!("")` to
+ /// print a newline.
+ ///
+ /// ### Why is this bad?
+ /// You should use `println!()`, which is simpler.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// println!("");
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
+ /// println!();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub PRINTLN_EMPTY_STRING,
+ style,
+ "using `println!(\"\")` with an empty string"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint warns when you use `print!()` with a format
+ /// string that ends in a newline.
+ ///
+ /// ### Why is this bad?
+ /// You should use `println!()` instead, which appends the
+ /// newline.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let name = "World";
+ /// print!("Hello {}!\n", name);
+ /// ```
+ /// use println!() instead
+ /// ```rust
+ /// # let name = "World";
+ /// println!("Hello {}!", name);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub PRINT_WITH_NEWLINE,
+ style,
+ "using `print!()` with a format string that ends in a single newline"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for printing on *stdout*. The purpose of this lint
+ /// is to catch debugging remnants.
+ ///
+ /// ### Why is this bad?
+ /// People often print on *stdout* while debugging an
+ /// application and might forget to remove those prints afterward.
+ ///
+ /// ### Known problems
+ /// * Only catches `print!` and `println!` calls.
+ /// * The lint level is unaffected by crate attributes. The level can still
+ /// be set for functions, modules and other items. To change the level for
+ /// the entire crate, please use command line flags. More information and a
+ /// configuration example can be found in [clippy#6610].
+ ///
+ /// [clippy#6610]: https://github.com/rust-lang/rust-clippy/issues/6610#issuecomment-977120558
+ ///
+ /// ### Example
+ /// ```rust
+ /// println!("Hello world!");
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub PRINT_STDOUT,
+ restriction,
+ "printing on stdout"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for printing on *stderr*. The purpose of this lint
+ /// is to catch debugging remnants.
+ ///
+ /// ### Why is this bad?
+ /// People often print on *stderr* while debugging an
+ /// application and might forget to remove those prints afterward.
+ ///
+ /// ### Known problems
+ /// * Only catches `eprint!` and `eprintln!` calls.
+ /// * The lint level is unaffected by crate attributes. The level can still
+ /// be set for functions, modules and other items. To change the level for
+ /// the entire crate, please use command line flags. More information and a
+ /// configuration example can be found in [clippy#6610].
+ ///
+ /// [clippy#6610]: https://github.com/rust-lang/rust-clippy/issues/6610#issuecomment-977120558
+ ///
+ /// ### Example
+ /// ```rust
+ /// eprintln!("Hello world!");
+ /// ```
+ #[clippy::version = "1.50.0"]
+ pub PRINT_STDERR,
+ restriction,
+ "printing on stderr"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for use of `Debug` formatting. The purpose of this
+ /// lint is to catch debugging remnants.
+ ///
+ /// ### Why is this bad?
+ /// The purpose of the `Debug` trait is to facilitate
+ /// debugging Rust code. It should not be used in user-facing output.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let foo = "bar";
+ /// println!("{:?}", foo);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub USE_DEBUG,
+ restriction,
+ "use of `Debug`-based formatting"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint warns about the use of literals as `print!`/`println!` args.
+ ///
+ /// ### Why is this bad?
+ /// Using literals as `println!` args is inefficient
+ /// (c.f., https://github.com/matthiaskrgr/rust-str-bench) and unnecessary
+ /// (i.e., just put the literal in the format string)
+ ///
+ /// ### Known problems
+ /// Will also warn with macro calls as arguments that expand to literals
+ /// -- e.g., `println!("{}", env!("FOO"))`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// println!("{}", "foo");
+ /// ```
+ /// use the literal without formatting:
+ /// ```rust
+ /// println!("foo");
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub PRINT_LITERAL,
+ style,
+ "printing a literal with a format string"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint warns when you use `writeln!(buf, "")` to
+ /// print a newline.
+ ///
+ /// ### Why is this bad?
+ /// You should use `writeln!(buf)`, which is simpler.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::fmt::Write;
+ /// # let mut buf = String::new();
- /// // Good
+ /// writeln!(buf, "");
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # use std::fmt::Write;
++ /// # let mut buf = String::new();
+ /// writeln!(buf);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub WRITELN_EMPTY_STRING,
+ style,
+ "using `writeln!(buf, \"\")` with an empty string"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint warns when you use `write!()` with a format
+ /// string that
+ /// ends in a newline.
+ ///
+ /// ### Why is this bad?
+ /// You should use `writeln!()` instead, which appends the
+ /// newline.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::fmt::Write;
+ /// # let mut buf = String::new();
+ /// # let name = "World";
- /// // Good
+ /// write!(buf, "Hello {}!\n", name);
++ /// ```
+ ///
- /// // Bad
++ /// Use instead:
++ /// ```rust
++ /// # use std::fmt::Write;
++ /// # let mut buf = String::new();
++ /// # let name = "World";
+ /// writeln!(buf, "Hello {}!", name);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub WRITE_WITH_NEWLINE,
+ style,
+ "using `write!()` with a format string that ends in a single newline"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint warns about the use of literals as `write!`/`writeln!` args.
+ ///
+ /// ### Why is this bad?
+ /// Using literals as `writeln!` args is inefficient
+ /// (c.f., https://github.com/matthiaskrgr/rust-str-bench) and unnecessary
+ /// (i.e., just put the literal in the format string)
+ ///
+ /// ### Known problems
+ /// Will also warn with macro calls as arguments that expand to literals
+ /// -- e.g., `writeln!(buf, "{}", env!("FOO"))`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::fmt::Write;
+ /// # let mut buf = String::new();
- /// // Good
+ /// writeln!(buf, "{}", "foo");
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
++ /// # use std::fmt::Write;
++ /// # let mut buf = String::new();
+ /// writeln!(buf, "foo");
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub WRITE_LITERAL,
+ style,
+ "writing a literal with a format string"
+}
+
+#[derive(Default)]
+pub struct Write {
+ in_debug_impl: bool,
+}
+
+impl_lint_pass!(Write => [
+ PRINT_WITH_NEWLINE,
+ PRINTLN_EMPTY_STRING,
+ PRINT_STDOUT,
+ PRINT_STDERR,
+ USE_DEBUG,
+ PRINT_LITERAL,
+ WRITE_WITH_NEWLINE,
+ WRITELN_EMPTY_STRING,
+ WRITE_LITERAL
+]);
+
+impl EarlyLintPass for Write {
+ fn check_item(&mut self, _: &EarlyContext<'_>, item: &Item) {
+ if let ItemKind::Impl(box Impl {
+ of_trait: Some(trait_ref),
+ ..
+ }) = &item.kind
+ {
+ let trait_name = trait_ref
+ .path
+ .segments
+ .iter()
+ .last()
+ .expect("path has at least one segment")
+ .ident
+ .name;
+ if trait_name == sym::Debug {
+ self.in_debug_impl = true;
+ }
+ }
+ }
+
+ fn check_item_post(&mut self, _: &EarlyContext<'_>, _: &Item) {
+ self.in_debug_impl = false;
+ }
+
+ fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &MacCall) {
+ fn is_build_script(cx: &EarlyContext<'_>) -> bool {
+ // Cargo sets the crate name for build scripts to `build_script_build`
+ cx.sess()
+ .opts
+ .crate_name
+ .as_ref()
+ .map_or(false, |crate_name| crate_name == "build_script_build")
+ }
+
+ if mac.path == sym!(print) {
+ if !is_build_script(cx) {
+ span_lint(cx, PRINT_STDOUT, mac.span(), "use of `print!`");
+ }
+ self.lint_print_with_newline(cx, mac);
+ } else if mac.path == sym!(println) {
+ if !is_build_script(cx) {
+ span_lint(cx, PRINT_STDOUT, mac.span(), "use of `println!`");
+ }
+ self.lint_println_empty_string(cx, mac);
+ } else if mac.path == sym!(eprint) {
+ span_lint(cx, PRINT_STDERR, mac.span(), "use of `eprint!`");
+ self.lint_print_with_newline(cx, mac);
+ } else if mac.path == sym!(eprintln) {
+ span_lint(cx, PRINT_STDERR, mac.span(), "use of `eprintln!`");
+ self.lint_println_empty_string(cx, mac);
+ } else if mac.path == sym!(write) {
+ if let (Some(fmt_str), dest) = self.check_tts(cx, mac.args.inner_tokens(), true) {
+ if check_newlines(&fmt_str) {
+ let (nl_span, only_nl) = newline_span(&fmt_str);
+ let nl_span = match (dest, only_nl) {
+ // Special case of `write!(buf, "\n")`: Mark everything from the end of
+ // `buf` for removal so no trailing comma [`writeln!(buf, )`] remains.
+ (Some(dest_expr), true) => nl_span.with_lo(dest_expr.span.hi()),
+ _ => nl_span,
+ };
+ span_lint_and_then(
+ cx,
+ WRITE_WITH_NEWLINE,
+ mac.span(),
+ "using `write!()` with a format string that ends in a single newline",
+ |err| {
+ err.multipart_suggestion(
+ "use `writeln!()` instead",
+ vec![(mac.path.span, String::from("writeln")), (nl_span, String::new())],
+ Applicability::MachineApplicable,
+ );
+ },
+ );
+ }
+ }
+ } else if mac.path == sym!(writeln) {
+ if let (Some(fmt_str), expr) = self.check_tts(cx, mac.args.inner_tokens(), true) {
+ if fmt_str.symbol == kw::Empty {
+ let mut applicability = Applicability::MachineApplicable;
+ let suggestion = if let Some(e) = expr {
+ snippet_with_applicability(cx, e.span, "v", &mut applicability)
+ } else {
+ applicability = Applicability::HasPlaceholders;
+ Cow::Borrowed("v")
+ };
+
+ span_lint_and_sugg(
+ cx,
+ WRITELN_EMPTY_STRING,
+ mac.span(),
+ format!("using `writeln!({}, \"\")`", suggestion).as_str(),
+ "replace it with",
+ format!("writeln!({})", suggestion),
+ applicability,
+ );
+ }
+ }
+ }
+ }
+}
+
+/// Given a format string that ends in a newline and its span, calculates the span of the
+/// newline, or the format string itself if the format string consists solely of a newline.
+/// Return this and a boolean indicating whether it only consisted of a newline.
+fn newline_span(fmtstr: &StrLit) -> (Span, bool) {
+ let sp = fmtstr.span;
+ let contents = fmtstr.symbol.as_str();
+
+ if contents == r"\n" {
+ return (sp, true);
+ }
+
+ let newline_sp_hi = sp.hi()
+ - match fmtstr.style {
+ StrStyle::Cooked => BytePos(1),
+ StrStyle::Raw(hashes) => BytePos((1 + hashes).into()),
+ };
+
+ let newline_sp_len = if contents.ends_with('\n') {
+ BytePos(1)
+ } else if contents.ends_with(r"\n") {
+ BytePos(2)
+ } else {
+ panic!("expected format string to contain a newline");
+ };
+
+ (sp.with_lo(newline_sp_hi - newline_sp_len).with_hi(newline_sp_hi), false)
+}
+
+/// Stores a list of replacement spans for each argument, but only if all the replacements used an
+/// empty format string.
+#[derive(Default)]
+struct SimpleFormatArgs {
+ unnamed: Vec<Vec<Span>>,
+ named: Vec<(Symbol, Vec<Span>)>,
+}
+impl SimpleFormatArgs {
+ fn get_unnamed(&self) -> impl Iterator<Item = &[Span]> {
+ self.unnamed.iter().map(|x| match x.as_slice() {
+ // Ignore the dummy span added from out of order format arguments.
+ [DUMMY_SP] => &[],
+ x => x,
+ })
+ }
+
+ fn get_named(&self, n: &Path) -> &[Span] {
+ self.named.iter().find(|x| *n == x.0).map_or(&[], |x| x.1.as_slice())
+ }
+
+ fn push(&mut self, arg: rustc_parse_format::Argument<'_>, span: Span) {
+ use rustc_parse_format::{
+ AlignUnknown, ArgumentImplicitlyIs, ArgumentIs, ArgumentNamed, CountImplied, FormatSpec,
+ };
+
+ const SIMPLE: FormatSpec<'_> = FormatSpec {
+ fill: None,
+ align: AlignUnknown,
+ flags: 0,
+ precision: CountImplied,
+ precision_span: None,
+ width: CountImplied,
+ width_span: None,
+ ty: "",
+ ty_span: None,
+ };
+
+ match arg.position {
+ ArgumentIs(n) | ArgumentImplicitlyIs(n) => {
+ if self.unnamed.len() <= n {
+ // Use a dummy span to mark all unseen arguments.
+ self.unnamed.resize_with(n, || vec![DUMMY_SP]);
+ if arg.format == SIMPLE {
+ self.unnamed.push(vec![span]);
+ } else {
+ self.unnamed.push(Vec::new());
+ }
+ } else {
+ let args = &mut self.unnamed[n];
+ match (args.as_mut_slice(), arg.format == SIMPLE) {
+ // A non-empty format string has been seen already.
+ ([], _) => (),
+ // Replace the dummy span, if it exists.
+ ([dummy @ DUMMY_SP], true) => *dummy = span,
+ ([_, ..], true) => args.push(span),
+ ([_, ..], false) => *args = Vec::new(),
+ }
+ }
+ },
+ ArgumentNamed(n, _) => {
+ let n = Symbol::intern(n);
+ if let Some(x) = self.named.iter_mut().find(|x| x.0 == n) {
+ match x.1.as_slice() {
+ // A non-empty format string has been seen already.
+ [] => (),
+ [_, ..] if arg.format == SIMPLE => x.1.push(span),
+ [_, ..] => x.1 = Vec::new(),
+ }
+ } else if arg.format == SIMPLE {
+ self.named.push((n, vec![span]));
+ } else {
+ self.named.push((n, Vec::new()));
+ }
+ },
+ };
+ }
+}
+
+impl Write {
+ /// Parses a format string into a collection of spans for each argument. This only keeps track
+ /// of empty format arguments. Will also lint usages of debug format strings outside of debug
+ /// impls.
+ fn parse_fmt_string(&self, cx: &EarlyContext<'_>, str_lit: &StrLit) -> Option<SimpleFormatArgs> {
+ use rustc_parse_format::{ParseMode, Parser, Piece};
+
+ let str_sym = str_lit.symbol_unescaped.as_str();
+ let style = match str_lit.style {
+ StrStyle::Cooked => None,
+ StrStyle::Raw(n) => Some(n as usize),
+ };
+
+ let mut parser = Parser::new(str_sym, style, snippet_opt(cx, str_lit.span), false, ParseMode::Format);
+ let mut args = SimpleFormatArgs::default();
+
+ while let Some(arg) = parser.next() {
+ let arg = match arg {
+ Piece::String(_) => continue,
+ Piece::NextArgument(arg) => arg,
+ };
+ let span = parser
+ .arg_places
+ .last()
+ .map_or(DUMMY_SP, |&x| str_lit.span.from_inner(InnerSpan::new(x.start, x.end)));
+
+ if !self.in_debug_impl && arg.format.ty == "?" {
+ // FIXME: modify rustc's fmt string parser to give us the current span
+ span_lint(cx, USE_DEBUG, span, "use of `Debug`-based formatting");
+ }
+
+ args.push(arg, span);
+ }
+
+ parser.errors.is_empty().then(move || args)
+ }
+
+ /// Checks the arguments of `print[ln]!` and `write[ln]!` calls. It will return a tuple of two
+ /// `Option`s. The first `Option` of the tuple is the macro's format string. It includes
+ /// the contents of the string, whether it's a raw string, and the span of the literal in the
+ /// source. The second `Option` in the tuple is, in the `write[ln]!` case, the expression the
+ /// `format_str` should be written to.
+ ///
+ /// Example:
+ ///
+ /// Calling this function on
+ /// ```rust
+ /// # use std::fmt::Write;
+ /// # let mut buf = String::new();
+ /// # let something = "something";
+ /// writeln!(buf, "string to write: {}", something);
+ /// ```
+ /// will return
+ /// ```rust,ignore
+ /// (Some("string to write: {}"), Some(buf))
+ /// ```
+ fn check_tts<'a>(&self, cx: &EarlyContext<'a>, tts: TokenStream, is_write: bool) -> (Option<StrLit>, Option<Expr>) {
+ let mut parser = parser::Parser::new(&cx.sess().parse_sess, tts, false, None);
+ let expr = if is_write {
+ match parser
+ .parse_expr()
+ .map(rustc_ast::ptr::P::into_inner)
+ .map_err(DiagnosticBuilder::cancel)
+ {
+ // write!(e, ...)
+ Ok(p) if parser.eat(&token::Comma) => Some(p),
+ // write!(e) or error
+ e => return (None, e.ok()),
+ }
+ } else {
+ None
+ };
+
+ let fmtstr = match parser.parse_str_lit() {
+ Ok(fmtstr) => fmtstr,
+ Err(_) => return (None, expr),
+ };
+
+ let args = match self.parse_fmt_string(cx, &fmtstr) {
+ Some(args) => args,
+ None => return (Some(fmtstr), expr),
+ };
+
+ let lint = if is_write { WRITE_LITERAL } else { PRINT_LITERAL };
+ let mut unnamed_args = args.get_unnamed();
+ loop {
+ if !parser.eat(&token::Comma) {
+ return (Some(fmtstr), expr);
+ }
+
+ let comma_span = parser.prev_token.span;
+ let token_expr = if let Ok(expr) = parser.parse_expr().map_err(DiagnosticBuilder::cancel) {
+ expr
+ } else {
+ return (Some(fmtstr), None);
+ };
+ let (fmt_spans, lit) = match &token_expr.kind {
+ ExprKind::Lit(lit) => (unnamed_args.next().unwrap_or(&[]), lit),
+ ExprKind::Assign(lhs, rhs, _) => match (&lhs.kind, &rhs.kind) {
+ (ExprKind::Path(_, p), ExprKind::Lit(lit)) => (args.get_named(p), lit),
+ _ => continue,
+ },
+ _ => {
+ unnamed_args.next();
+ continue;
+ },
+ };
+
+ let replacement: String = match lit.token.kind {
+ LitKind::StrRaw(_) | LitKind::ByteStrRaw(_) if matches!(fmtstr.style, StrStyle::Raw(_)) => {
+ lit.token.symbol.as_str().replace('{', "{{").replace('}', "}}")
+ },
+ LitKind::Str | LitKind::ByteStr if matches!(fmtstr.style, StrStyle::Cooked) => {
+ lit.token.symbol.as_str().replace('{', "{{").replace('}', "}}")
+ },
+ LitKind::StrRaw(_)
+ | LitKind::Str
+ | LitKind::ByteStrRaw(_)
+ | LitKind::ByteStr
+ | LitKind::Integer
+ | LitKind::Float
+ | LitKind::Err => continue,
+ LitKind::Byte | LitKind::Char => match lit.token.symbol.as_str() {
+ "\"" if matches!(fmtstr.style, StrStyle::Cooked) => "\\\"",
+ "\"" if matches!(fmtstr.style, StrStyle::Raw(0)) => continue,
+ "\\\\" if matches!(fmtstr.style, StrStyle::Raw(_)) => "\\",
+ "\\'" => "'",
+ "{" => "{{",
+ "}" => "}}",
+ x if matches!(fmtstr.style, StrStyle::Raw(_)) && x.starts_with('\\') => continue,
+ x => x,
+ }
+ .into(),
+ LitKind::Bool => lit.token.symbol.as_str().deref().into(),
+ };
+
+ if !fmt_spans.is_empty() {
+ span_lint_and_then(
+ cx,
+ lint,
+ token_expr.span,
+ "literal with an empty format string",
+ |diag| {
+ diag.multipart_suggestion(
+ "try this",
+ iter::once((comma_span.to(token_expr.span), String::new()))
+ .chain(fmt_spans.iter().copied().zip(iter::repeat(replacement)))
+ .collect(),
+ Applicability::MachineApplicable,
+ );
+ },
+ );
+ }
+ }
+ }
+
+ fn lint_println_empty_string(&self, cx: &EarlyContext<'_>, mac: &MacCall) {
+ if let (Some(fmt_str), _) = self.check_tts(cx, mac.args.inner_tokens(), false) {
+ if fmt_str.symbol == kw::Empty {
+ let name = mac.path.segments[0].ident.name;
+ span_lint_and_sugg(
+ cx,
+ PRINTLN_EMPTY_STRING,
+ mac.span(),
+ &format!("using `{}!(\"\")`", name),
+ "replace it with",
+ format!("{}!()", name),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ }
+
+ fn lint_print_with_newline(&self, cx: &EarlyContext<'_>, mac: &MacCall) {
+ if let (Some(fmt_str), _) = self.check_tts(cx, mac.args.inner_tokens(), false) {
+ if check_newlines(&fmt_str) {
+ let name = mac.path.segments[0].ident.name;
+ let suggested = format!("{}ln", name);
+ span_lint_and_then(
+ cx,
+ PRINT_WITH_NEWLINE,
+ mac.span(),
+ &format!("using `{}!()` with a format string that ends in a single newline", name),
+ |err| {
+ err.multipart_suggestion(
+ &format!("use `{}!` instead", suggested),
+ vec![(mac.path.span, suggested), (newline_span(&fmt_str).0, String::new())],
+ Applicability::MachineApplicable,
+ );
+ },
+ );
+ }
+ }
+ }
+}
+
+/// Checks if the format string contains a single newline that terminates it.
+///
+/// Literal and escaped newlines are both checked (only literal for raw strings).
+fn check_newlines(fmtstr: &StrLit) -> bool {
+ let mut has_internal_newline = false;
+ let mut last_was_cr = false;
+ let mut should_lint = false;
+
+ let contents = fmtstr.symbol.as_str();
+
+ let mut cb = |r: Range<usize>, c: Result<char, EscapeError>| {
+ let c = c.unwrap();
+
+ if r.end == contents.len() && c == '\n' && !last_was_cr && !has_internal_newline {
+ should_lint = true;
+ } else {
+ last_was_cr = c == '\r';
+ if c == '\n' {
+ has_internal_newline = true;
+ }
+ }
+ };
+
+ match fmtstr.style {
+ StrStyle::Cooked => unescape::unescape_literal(contents, unescape::Mode::Str, &mut cb),
+ StrStyle::Raw(_) => unescape::unescape_literal(contents, unescape::Mode::RawStr, &mut cb),
+ }
+
+ should_lint
+}
--- /dev/null
- /// // Bad
+use clippy_utils::consts::{constant_simple, Constant};
+use clippy_utils::diagnostics::span_lint_and_help;
+use if_chain::if_chain;
+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 for `0.0 / 0.0`.
+ ///
+ /// ### Why is this bad?
+ /// It's less readable than `f32::NAN` or `f64::NAN`.
+ ///
+ /// ### Example
+ /// ```rust
- /// // Good
+ /// let nan = 0.0f32 / 0.0;
++ /// ```
+ ///
++ /// Use instead:
++ /// ```rust
+ /// let nan = f32::NAN;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub ZERO_DIVIDED_BY_ZERO,
+ complexity,
+ "usage of `0.0 / 0.0` to obtain NaN instead of `f32::NAN` or `f64::NAN`"
+}
+
+declare_lint_pass!(ZeroDiv => [ZERO_DIVIDED_BY_ZERO]);
+
+impl<'tcx> LateLintPass<'tcx> for ZeroDiv {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ // check for instances of 0.0/0.0
+ if_chain! {
+ if let ExprKind::Binary(ref op, left, right) = expr.kind;
+ if op.node == BinOpKind::Div;
+ // TODO - constant_simple does not fold many operations involving floats.
+ // That's probably fine for this lint - it's pretty unlikely that someone would
+ // do something like 0.0/(2.0 - 2.0), but it would be nice to warn on that case too.
+ if let Some(lhs_value) = constant_simple(cx, cx.typeck_results(), left);
+ if let Some(rhs_value) = constant_simple(cx, cx.typeck_results(), right);
+ if Constant::F32(0.0) == lhs_value || Constant::F64(0.0) == lhs_value;
+ if Constant::F32(0.0) == rhs_value || Constant::F64(0.0) == rhs_value;
+ then {
+ // since we're about to suggest a use of f32::NAN or f64::NAN,
+ // match the precision of the literals that are given.
+ let float_type = match (lhs_value, rhs_value) {
+ (Constant::F64(_), _)
+ | (_, Constant::F64(_)) => "f64",
+ _ => "f32"
+ };
+ span_lint_and_help(
+ cx,
+ ZERO_DIVIDED_BY_ZERO,
+ expr.span,
+ "constant division of `0.0` with `0.0` will always result in NaN",
+ None,
+ &format!(
+ "consider using `{}::NAN` if you would like a constant representing NaN",
+ float_type,
+ ),
+ );
+ }
+ }
+ }
+}
--- /dev/null
- .inspect_with_uninit_and_ptr_outside_interpreter(0..(4 * len as usize))
+#![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;
+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::mir::ConstantKind::from_value(val, ty))?;
+ let result = miri_to_const(self.lcx.tcx, 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<'tcx>(tcx: TyCtxt<'tcx>, result: mir::ConstantKind<'tcx>) -> Option<Constant> {
+ use rustc_middle::mir::interpret::ConstValue;
+ match result {
+ mir::ConstantKind::Val(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,
+ }
+ },
+ mir::ConstantKind::Val(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,
+ },
+ mir::ConstantKind::Val(ConstValue::ByRef { alloc, offset: _ }, _) => match result.ty().kind() {
+ ty::Array(sub_type, len) => match sub_type.kind() {
+ ty::Float(FloatTy::F32) => match len.to_valtree().try_to_machine_usize(tcx) {
+ Some(len) => alloc
+ .inner()
- .inspect_with_uninit_and_ptr_outside_interpreter(0..(8 * len as usize))
++ .inspect_with_uninit_and_ptr_outside_interpreter(0..(4 * usize::try_from(len).unwrap()))
+ .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 len.to_valtree().try_to_machine_usize(tcx) {
+ Some(len) => alloc
+ .inner()
++ .inspect_with_uninit_and_ptr_outside_interpreter(0..(8 * usize::try_from(len).unwrap()))
+ .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
- locals: HirIdMap<HirId>,
+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`.
++ pub 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_mut.mutbl == r_mut.mutbl && self.eq_ty(l_mut.ty, r_mut.ty)
+ },
+ (&TyKind::Rptr(_, ref l_rmut), &TyKind::Rptr(_, ref r_rmut)) => {
+ 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 {
+ capture_clause, body, ..
+ } => {
+ std::mem::discriminant(&capture_clause).hash(&mut self.s);
+ // closures inherit TypeckResults
+ self.hash_expr(&self.cx.tcx.hir().body(body).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()),
+ }
+ }
+ }
+}
++
++pub fn hash_stmt(cx: &LateContext<'_>, s: &Stmt<'_>) -> u64 {
++ let mut h = SpanlessHash::new(cx);
++ h.hash_stmt(s);
++ h.finish()
++}
++
++pub fn hash_expr(cx: &LateContext<'_>, e: &Expr<'_>) -> u64 {
++ let mut h = SpanlessHash::new(cx);
++ h.hash_expr(e);
++ h.finish()
++}
--- /dev/null
- pub use self::hir_utils::{both, count_eq, eq_expr_value, over, SpanlessEq, SpanlessHash};
+#![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, hash_expr, hash_stmt, over, HirEqInterExpr, 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, _) => {
+ 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) {
+ 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, .. } => is_body_identity_function(cx, cx.tcx.hir().body(body)),
+ _ => 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,
+ ..
+ },
+ ..,
+ ) => {
+ // 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
- .map(|assoc| {
+//! 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::{
+ 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)
- cx.tcx.normalize_erasing_regions(cx.param_env, proj)
++ .and_then(|assoc| {
+ let proj = cx.tcx.mk_projection(assoc.def_id, cx.tcx.mk_substs_trait(ty, &[]));
++ cx.tcx.try_normalize_erasing_regions(cx.param_env, proj).ok()
+ })
+}
+
+/// 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 = tcx.erase_regions(ty);
+ if ty.has_escaping_bound_vars() {
+ return false;
+ }
+ 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
- use clap::{Arg, ArgMatches, Command};
++use clap::{Arg, ArgAction, ArgMatches, Command};
+use std::env;
+use std::path::PathBuf;
+
+fn get_clap_config() -> ArgMatches {
+ Command::new("lintcheck")
+ .about("run clippy on a set of crates and check output")
- .arg(
++ .args([
+ Arg::new("only")
- .takes_value(true)
++ .action(ArgAction::Set)
+ .value_name("CRATE")
+ .long("only")
+ .help("Only process a single crate of the list"),
- )
- .arg(
+ Arg::new("crates-toml")
- .takes_value(true)
++ .action(ArgAction::Set)
+ .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::new("threads")
- .takes_value(true)
++ .action(ArgAction::Set)
+ .value_name("N")
++ .value_parser(clap::value_parser!(usize))
+ .short('j')
+ .long("jobs")
+ .help("Number of threads to use, 0 automatic choice"),
- )
- .arg(
+ Arg::new("fix")
- .long("--fix")
++ .long("fix")
+ .help("Runs cargo clippy --fix and checks if all suggestions apply"),
- )
- .arg(
+ Arg::new("filter")
- .long("--filter")
- .takes_value(true)
- .multiple_occurrences(true)
++ .long("filter")
++ .action(ArgAction::Append)
+ .value_name("clippy_lint_name")
+ .help("Apply a filter to only collect specified lints, this also overrides `allow` attributes"),
- )
- .arg(
+ Arg::new("markdown")
- .long("--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()
++ .get_one::<String>("crates-toml")
++ .map(|s| &**s)
+ .unwrap_or("lintcheck/lintcheck_crates.toml")
- .to_string()
++ .into()
+ });
+
- let markdown = clap_config.is_present("markdown");
++ let markdown = clap_config.contains_id("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
- }
++ let max_jobs = match clap_config.get_one::<usize>("threads") {
++ Some(&0) => {
++ // automatic choice
++ // Rayon seems to return thread count so half that for core count
++ (rayon::current_num_threads() / 2) as usize
+ },
++ Some(&threads) => threads,
+ // no -j passed, use a single thread
+ None => 1,
+ };
+
+ let lint_filter: Vec<String> = clap_config
- .values_of("filter")
++ .get_many::<String>("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"),
++ only: clap_config.get_one::<String>("only").map(String::from),
++ fix: clap_config.contains_id("fix"),
+ lint_filter,
+ markdown,
+ }
+ }
+}
--- /dev/null
- channel = "nightly-2022-06-04"
+[toolchain]
++channel = "nightly-2022-06-16"
+components = ["cargo", "llvm-tools-preview", "rust-src", "rust-std", "rustc", "rustc-dev", "rustfmt"]
--- /dev/null
- run_clippy_for_package(package, &[]);
+//! This test is a part of quality control and makes clippy eat what it produces. Awesome lints and
+//! long error messages
+//!
+//! See [Eating your own dog food](https://en.wikipedia.org/wiki/Eating_your_own_dog_food) for context
+
+#![feature(once_cell)]
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+#![warn(rust_2018_idioms, unused_lifetimes)]
+
+use std::path::PathBuf;
+use std::process::Command;
+use test_utils::IS_RUSTC_TEST_SUITE;
+
+mod test_utils;
+
+#[test]
+fn dogfood_clippy() {
+ if IS_RUSTC_TEST_SUITE {
+ return;
+ }
+
+ // "" is the root package
+ for package in &["", "clippy_dev", "clippy_lints", "clippy_utils", "rustc_tools_util"] {
- .args(&["-D", "clippy::all"])
- .args(&["-D", "clippy::pedantic"])
++ run_clippy_for_package(package, &["-D", "clippy::all", "-D", "clippy::pedantic"]);
+ }
+}
+
+#[test]
+#[ignore]
+#[cfg(feature = "internal")]
+fn run_metadata_collection_lint() {
+ use std::fs::File;
+ use std::time::SystemTime;
+
+ // Setup for validation
+ let metadata_output_path = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("util/gh-pages/lints.json");
+ let start_time = SystemTime::now();
+
+ // Run collection as is
+ std::env::set_var("ENABLE_METADATA_COLLECTION", "1");
+ run_clippy_for_package("clippy_lints", &["-A", "unfulfilled_lint_expectations"]);
+
+ // Check if cargo caching got in the way
+ if let Ok(file) = File::open(metadata_output_path) {
+ if let Ok(metadata) = file.metadata() {
+ if let Ok(last_modification) = metadata.modified() {
+ if last_modification > start_time {
+ // The output file has been modified. Most likely by a hungry
+ // metadata collection monster. So We'll return.
+ return;
+ }
+ }
+ }
+ }
+
+ // Force cargo to invalidate the caches
+ filetime::set_file_mtime(
+ PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("clippy_lints/src/lib.rs"),
+ filetime::FileTime::now(),
+ )
+ .unwrap();
+
+ // Running the collection again
+ run_clippy_for_package("clippy_lints", &["-A", "unfulfilled_lint_expectations"]);
+}
+
+fn run_clippy_for_package(project: &str, args: &[&str]) {
+ let root_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+
+ let mut command = Command::new(&*test_utils::CARGO_CLIPPY_PATH);
+
+ command
+ .current_dir(root_dir.join(project))
+ .env("CARGO_INCREMENTAL", "0")
+ .arg("clippy")
+ .arg("--all-targets")
+ .arg("--all-features")
+ .arg("--")
+ .args(args)
+ .arg("-Cdebuginfo=0"); // disable debuginfo to generate less data in the target dir
+
+ if cfg!(feature = "internal") {
+ // internal lints only exist if we build with the internal feature
+ command.args(&["-D", "clippy::internal"]);
+ } else {
+ // running a clippy built without internal lints on the clippy source
+ // that contains e.g. `allow(clippy::invalid_paths)`
+ command.args(&["-A", "unknown_lints"]);
+ }
+
+ let output = command.output().unwrap();
+
+ println!("status: {}", output.status);
+ println!("stdout: {}", String::from_utf8_lossy(&output.stdout));
+ println!("stderr: {}", String::from_utf8_lossy(&output.stderr));
+
+ assert!(output.status.success());
+}
--- /dev/null
- // error-pattern: error reading Clippy's configuration file
-
+fn main() {}
--- /dev/null
- // error-pattern: error reading Clippy's configuration file: `blacklisted-names` is expected to be a
- // `Vec < String >` but is a `integer`
-
+fn main() {}
--- /dev/null
--- /dev/null
++#[warn(clippy::blacklisted_name)]
++
++fn main() {
++ // `foo` is part of the default configuration
++ let foo = "bar";
++ // `ducks` was unrightfully blacklisted
++ let ducks = ["quack", "quack"];
++ // `fox` is okay
++ let fox = ["what", "does", "the", "fox", "say", "?"];
++}
--- /dev/null
--- /dev/null
++error: use of a blacklisted/placeholder name `foo`
++ --> $DIR/blacklisted_names.rs:5:9
++ |
++LL | let foo = "bar";
++ | ^^^
++ |
++ = note: `-D clippy::blacklisted-name` implied by `-D warnings`
++
++error: use of a blacklisted/placeholder name `ducks`
++ --> $DIR/blacklisted_names.rs:7:9
++ |
++LL | let ducks = ["quack", "quack"];
++ | ^^^^^
++
++error: aborting due to 2 previous errors
++
--- /dev/null
--- /dev/null
++blacklisted-names = ["ducks", ".."]
--- /dev/null
--- /dev/null
++#[warn(clippy::blacklisted_name)]
++
++fn main() {
++ // `foo` is part of the default configuration
++ let foo = "bar";
++ // `ducks` was unrightfully blacklisted
++ let ducks = ["quack", "quack"];
++ // `fox` is okay
++ let fox = ["what", "does", "the", "fox", "say", "?"];
++}
--- /dev/null
--- /dev/null
++error: use of a blacklisted/placeholder name `ducks`
++ --> $DIR/blacklisted_names.rs:7:9
++ |
++LL | let ducks = ["quack", "quack"];
++ | ^^^^^
++ |
++ = note: `-D clippy::blacklisted-name` implied by `-D warnings`
++
++error: aborting due to previous error
++
--- /dev/null
--- /dev/null
++blacklisted-names = ["ducks"]
--- /dev/null
- // error-pattern: error reading Clippy's configuration file: found deprecated field
- // `cyclomatic-complexity-threshold`. Please use `cognitive-complexity-threshold` instead.
-
+fn main() {}
--- /dev/null
--- /dev/null
++doc-valid-idents = ["ClipPy", ".."]
--- /dev/null
--- /dev/null
++#![warn(clippy::doc_markdown)]
++
++/// This is a special interface for ClipPy which doesn't require backticks
++fn allowed_name() {}
++
++/// OAuth and LaTeX are inside Clippy's default list.
++fn default_name() {}
++
++/// TestItemThingyOfCoolness might sound cool but is not on the list and should be linted.
++fn unknown_name() {}
++
++fn main() {}
--- /dev/null
--- /dev/null
++error: item in documentation is missing backticks
++ --> $DIR/doc_markdown.rs:9:5
++ |
++LL | /// TestItemThingyOfCoolness might sound cool but is not on the list and should be linted.
++ | ^^^^^^^^^^^^^^^^^^^^^^^^
++ |
++ = note: `-D clippy::doc-markdown` implied by `-D warnings`
++help: try
++ |
++LL | /// `TestItemThingyOfCoolness` might sound cool but is not on the list and should be linted.
++ | ~~~~~~~~~~~~~~~~~~~~~~~~~~
++
++error: aborting due to previous error
++
--- /dev/null
--- /dev/null
++doc-valid-idents = ["ClipPy"]
--- /dev/null
--- /dev/null
++#![warn(clippy::doc_markdown)]
++
++/// This is a special interface for ClipPy which doesn't require backticks
++fn allowed_name() {}
++
++/// OAuth and LaTeX are inside Clippy's default list.
++fn default_name() {}
++
++/// TestItemThingyOfCoolness might sound cool but is not on the list and should be linted.
++fn unknown_name() {}
++
++fn main() {}
--- /dev/null
--- /dev/null
++error: item in documentation is missing backticks
++ --> $DIR/doc_markdown.rs:6:5
++ |
++LL | /// OAuth and LaTeX are inside Clippy's default list.
++ | ^^^^^
++ |
++ = note: `-D clippy::doc-markdown` implied by `-D warnings`
++help: try
++ |
++LL | /// `OAuth` and LaTeX are inside Clippy's default list.
++ | ~~~~~~~
++
++error: item in documentation is missing backticks
++ --> $DIR/doc_markdown.rs:6:15
++ |
++LL | /// OAuth and LaTeX are inside Clippy's default list.
++ | ^^^^^
++ |
++help: try
++ |
++LL | /// OAuth and `LaTeX` are inside Clippy's default list.
++ | ~~~~~~~
++
++error: item in documentation is missing backticks
++ --> $DIR/doc_markdown.rs:9:5
++ |
++LL | /// TestItemThingyOfCoolness might sound cool but is not on the list and should be linted.
++ | ^^^^^^^^^^^^^^^^^^^^^^^^
++ |
++help: try
++ |
++LL | /// `TestItemThingyOfCoolness` might sound cool but is not on the list and should be linted.
++ | ~~~~~~~~~~~~~~~~~~~~~~~~~~
++
++error: aborting due to 3 previous errors
++
--- /dev/null
- // error-pattern: should give absolutely no error
-
+fn main() {}
--- /dev/null
- // error-pattern: error reading Clippy's configuration file: unknown key `foobar`
-
+fn main() {}
--- /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)]
++#![allow(clippy::needless_parens_on_range_literals)]
+
+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
+// 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)]
++#![allow(clippy::needless_parens_on_range_literals)]
+
+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
- --> $DIR/almost_complete_letter_range.rs:19:17
+error: almost complete ascii letter range
- --> $DIR/almost_complete_letter_range.rs:20:17
++ --> $DIR/almost_complete_letter_range.rs:20:17
+ |
+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:26:13
++ --> $DIR/almost_complete_letter_range.rs:21:17
+ |
+LL | let _ = 'A' .. ('Z');
+ | ^^^^--^^^^^^
+ | |
+ | help: use an inclusive range: `..=`
+
+error: almost complete ascii letter range
- --> $DIR/almost_complete_letter_range.rs:27:13
++ --> $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
++ --> $DIR/almost_complete_letter_range.rs:28:13
+ |
+LL | let _ = b'A'..b'Z';
+ | ^^^^--^^^^
+ | |
+ | help: use an inclusive range: `..=`
+
+error: almost complete ascii letter range
- --> $DIR/almost_complete_letter_range.rs:35:9
++ --> $DIR/almost_complete_letter_range.rs:33:13
+ |
+LL | let _ = a!()..'z';
+ | ^^^^--^^^
+ | |
+ | help: use an inclusive range: `..=`
+
+error: almost complete ascii letter range
- --> $DIR/almost_complete_letter_range.rs:36:9
++ --> $DIR/almost_complete_letter_range.rs:36:9
+ |
+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:43:9
++ --> $DIR/almost_complete_letter_range.rs:37:9
+ |
+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:44:9
++ --> $DIR/almost_complete_letter_range.rs:44:9
+ |
+LL | 'a'..'z' if true => 1,
+ | ^^^--^^^
+ | |
+ | help: use an inclusive range: `..=`
+
+error: almost complete ascii letter range
- --> $DIR/almost_complete_letter_range.rs:54:9
++ --> $DIR/almost_complete_letter_range.rs:45:9
+ |
+LL | 'A'..'Z' if true => 2,
+ | ^^^--^^^
+ | |
+ | help: use an inclusive range: `..=`
+
+error: almost complete ascii letter range
- --> $DIR/almost_complete_letter_range.rs:61:13
++ --> $DIR/almost_complete_letter_range.rs:55:9
+ |
+LL | 'a'..'z' => 1,
+ | ^^^--^^^
+ | |
+ | help: use an inclusive range: `...`
+
+error: almost complete ascii letter range
- --> $DIR/almost_complete_letter_range.rs:63:9
++ --> $DIR/almost_complete_letter_range.rs:62:13
+ |
+LL | let _ = 'a'..'z';
+ | ^^^--^^^
+ | |
+ | help: use an inclusive range: `..=`
+
+error: almost complete ascii letter range
++ --> $DIR/almost_complete_letter_range.rs:64:9
+ |
+LL | 'a'..'z' => 1,
+ | ^^^--^^^
+ | |
+ | help: use an inclusive range: `..=`
+
+error: aborting due to 12 previous errors
+
--- /dev/null
-
+// run-rustfix
++#![feature(lint_reasons)]
+#![feature(async_closure)]
+#![warn(clippy::async_yields_async)]
+
+use core::future::Future;
+use core::pin::Pin;
+use core::task::{Context, Poll};
+
+struct CustomFutureType;
+
+impl Future for CustomFutureType {
+ type Output = u8;
+
+ fn poll(self: Pin<&mut Self>, _: &mut Context) -> Poll<Self::Output> {
+ Poll::Ready(3)
+ }
+}
+
+fn custom_future_type_ctor() -> CustomFutureType {
+ CustomFutureType
+}
+
+async fn f() -> CustomFutureType {
+ // Don't warn for functions since you have to explicitly declare their
+ // return types.
+ CustomFutureType
+}
+
+#[rustfmt::skip]
+fn main() {
+ let _f = {
+ 3
+ };
+ let _g = async {
+ 3
+ };
+ let _h = async {
+ async {
+ 3
+ }.await
+ };
+ let _i = async {
+ CustomFutureType.await
+ };
+ let _i = async || {
+ 3
+ };
+ let _j = async || {
+ async {
+ 3
+ }.await
+ };
+ let _k = async || {
+ CustomFutureType.await
+ };
+ let _l = async || CustomFutureType.await;
+ let _m = async || {
+ println!("I'm bored");
+ // Some more stuff
+
+ // Finally something to await
+ CustomFutureType.await
+ };
+ let _n = async || custom_future_type_ctor();
+ let _o = async || f();
+}
++
++#[rustfmt::skip]
++#[allow(dead_code)]
++fn check_expect_suppression() {
++ #[expect(clippy::async_yields_async)]
++ let _j = async || {
++ async {
++ 3
++ }
++ };
++}
--- /dev/null
-
+// run-rustfix
++#![feature(lint_reasons)]
+#![feature(async_closure)]
+#![warn(clippy::async_yields_async)]
+
+use core::future::Future;
+use core::pin::Pin;
+use core::task::{Context, Poll};
+
+struct CustomFutureType;
+
+impl Future for CustomFutureType {
+ type Output = u8;
+
+ fn poll(self: Pin<&mut Self>, _: &mut Context) -> Poll<Self::Output> {
+ Poll::Ready(3)
+ }
+}
+
+fn custom_future_type_ctor() -> CustomFutureType {
+ CustomFutureType
+}
+
+async fn f() -> CustomFutureType {
+ // Don't warn for functions since you have to explicitly declare their
+ // return types.
+ CustomFutureType
+}
+
+#[rustfmt::skip]
+fn main() {
+ let _f = {
+ 3
+ };
+ let _g = async {
+ 3
+ };
+ let _h = async {
+ async {
+ 3
+ }
+ };
+ let _i = async {
+ CustomFutureType
+ };
+ let _i = async || {
+ 3
+ };
+ let _j = async || {
+ async {
+ 3
+ }
+ };
+ let _k = async || {
+ CustomFutureType
+ };
+ let _l = async || CustomFutureType;
+ let _m = async || {
+ println!("I'm bored");
+ // Some more stuff
+
+ // Finally something to await
+ CustomFutureType
+ };
+ let _n = async || custom_future_type_ctor();
+ let _o = async || f();
+}
++
++#[rustfmt::skip]
++#[allow(dead_code)]
++fn check_expect_suppression() {
++ #[expect(clippy::async_yields_async)]
++ let _j = async || {
++ async {
++ 3
++ }
++ };
++}
--- /dev/null
- fn main() {}
+#![allow(dead_code)]
+#![deny(clippy::if_same_then_else, clippy::branches_sharing_code)]
+
+// ##################################
+// # Issue clippy#7369
+// ##################################
+#[derive(Debug)]
+pub struct FooBar {
+ foo: Vec<u32>,
+}
+
+impl FooBar {
+ pub fn bar(&mut self) {
+ if true {
+ self.foo.pop();
+ } else {
+ self.baz();
+
+ self.foo.pop();
+
+ self.baz()
+ }
+ }
+
+ fn baz(&mut self) {}
+}
+
++fn foo(x: u32, y: u32) -> u32 {
++ x / y
++}
++
++fn main() {
++ let x = (1, 2);
++ let _ = if true {
++ let (x, y) = x;
++ foo(x, y)
++ } else {
++ let (y, x) = x;
++ foo(x, y)
++ };
++}
--- /dev/null
- = note: The end suggestion probably needs some adjustments to use the expression result correctly
- help: consider moving the end statements out like this
+error: all if blocks contain the same code at the end
+ --> $DIR/shared_at_bottom.rs:30:5
+ |
+LL | / let result = false;
+LL | | println!("Block end!");
+LL | | result
+LL | | };
+ | |_____^
+ |
+note: the lint level is defined here
+ --> $DIR/shared_at_bottom.rs:2:36
+ |
+LL | #![deny(clippy::if_same_then_else, clippy::branches_sharing_code)]
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- help: consider moving the end statements out like this
++ = note: the end suggestion probably needs some adjustments to use the expression result correctly
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL + let result = false;
+LL + println!("Block end!");
+LL ~ result;
+ |
+
+error: all if blocks contain the same code at the end
+ --> $DIR/shared_at_bottom.rs:48:5
+ |
+LL | / println!("Same end of block");
+LL | | }
+ | |_____^
+ |
- help: consider moving the end statements out like this
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL + println!("Same end of block");
+ |
+
+error: all if blocks contain the same code at the end
+ --> $DIR/shared_at_bottom.rs:65:5
+ |
+LL | / println!(
+LL | | "I'm moveable because I know: `outer_scope_value`: '{}'",
+LL | | outer_scope_value
+LL | | );
+LL | | }
+ | |_____^
+ |
- help: consider moving the end statements out like this
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL + println!(
+LL + "I'm moveable because I know: `outer_scope_value`: '{}'",
+LL + outer_scope_value
+LL + );
+ |
+
+error: all if blocks contain the same code at the end
+ --> $DIR/shared_at_bottom.rs:77:9
+ |
+LL | / println!("Hello World");
+LL | | }
+ | |_________^
+ |
- = warning: Some moved values might need to be renamed to avoid wrong references
- help: consider moving the end statements out like this
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL + println!("Hello World");
+ |
+
+error: all if blocks contain the same code at the end
+ --> $DIR/shared_at_bottom.rs:93:5
+ |
+LL | / let later_used_value = "A string value";
+LL | | println!("{}", later_used_value);
+LL | | // I'm expecting a note about this
+LL | | }
+ | |_____^
+ |
- = warning: Some moved values might need to be renamed to avoid wrong references
- help: consider moving the end statements out like this
++ = warning: some moved values might need to be renamed to avoid wrong references
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL + let later_used_value = "A string value";
+LL + println!("{}", later_used_value);
+ |
+
+error: all if blocks contain the same code at the end
+ --> $DIR/shared_at_bottom.rs:106:5
+ |
+LL | / let simple_examples = "I now identify as a &str :)";
+LL | | println!("This is the new simple_example: {}", simple_examples);
+LL | | }
+ | |_____^
+ |
- = note: The end suggestion probably needs some adjustments to use the expression result correctly
- help: consider moving the end statements out like this
++ = warning: some moved values might need to be renamed to avoid wrong references
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL + let simple_examples = "I now identify as a &str :)";
+LL + println!("This is the new simple_example: {}", simple_examples);
+ |
+
+error: all if blocks contain the same code at the end
+ --> $DIR/shared_at_bottom.rs:171:5
+ |
+LL | / x << 2
+LL | | };
+ | |_____^
+ |
- = note: The end suggestion probably needs some adjustments to use the expression result correctly
- help: consider moving the end statements out like this
++ = note: the end suggestion probably needs some adjustments to use the expression result correctly
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL ~ x << 2;
+ |
+
+error: all if blocks contain the same code at the end
+ --> $DIR/shared_at_bottom.rs:178:5
+ |
+LL | / x * 4
+LL | | }
+ | |_____^
+ |
- help: consider moving the end statements out like this
++ = note: the end suggestion probably needs some adjustments to use the expression result correctly
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL + x * 4
+ |
+
+error: all if blocks contain the same code at the end
+ --> $DIR/shared_at_bottom.rs:190:44
+ |
+LL | if x == 17 { b = 1; a = 0x99; } else { a = 0x99; }
+ | ^^^^^^^^^^^
+ |
++help: consider moving these statements after the if
+ |
+LL ~ if x == 17 { b = 1; a = 0x99; } else { }
+LL + a = 0x99;
+ |
+
+error: aborting due to 9 previous errors
+
--- /dev/null
- help: consider moving the start statements out like this
+error: all if blocks contain the same code at the start
+ --> $DIR/shared_at_top.rs:10:5
+ |
+LL | / if true {
+LL | | println!("Hello World!");
+ | |_________________________________^
+ |
+note: the lint level is defined here
+ --> $DIR/shared_at_top.rs:2:36
+ |
+LL | #![deny(clippy::if_same_then_else, clippy::branches_sharing_code)]
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- = warning: Some moved values might need to be renamed to avoid wrong references
- help: consider moving the start statements out like this
++help: consider moving these statements before the if
+ |
+LL ~ println!("Hello World!");
+LL + if true {
+ |
+
+error: all if blocks contain the same code at the start
+ --> $DIR/shared_at_top.rs:19:5
+ |
+LL | / if x == 0 {
+LL | | let y = 9;
+LL | | println!("The value y was set to: `{}`", y);
+LL | | let _z = y;
+ | |___________________^
+ |
- help: consider moving the start statements out like this
++ = warning: some moved values might need to be renamed to avoid wrong references
++help: consider moving these statements before the if
+ |
+LL ~ let y = 9;
+LL + println!("The value y was set to: `{}`", y);
+LL + let _z = y;
+LL + if x == 0 {
+ |
+
+error: all if blocks contain the same code at the start
+ --> $DIR/shared_at_top.rs:40:5
+ |
+LL | / let _ = if x == 7 {
+LL | | let y = 16;
+ | |___________________^
+ |
- = warning: Some moved values might need to be renamed to avoid wrong references
- help: consider moving the start statements out like this
++help: consider moving these statements before the if
+ |
+LL ~ let y = 16;
+LL + let _ = if x == 7 {
+ |
+
+error: all if blocks contain the same code at the start
+ --> $DIR/shared_at_top.rs:58:5
+ |
+LL | / if x == 10 {
+LL | | let used_value_name = "Different type";
+LL | | println!("Str: {}", used_value_name);
+ | |_____________________________________________^
+ |
- = warning: Some moved values might need to be renamed to avoid wrong references
- help: consider moving the start statements out like this
++ = warning: some moved values might need to be renamed to avoid wrong references
++help: consider moving these statements before the if
+ |
+LL ~ let used_value_name = "Different type";
+LL + println!("Str: {}", used_value_name);
+LL + if x == 10 {
+ |
+
+error: all if blocks contain the same code at the start
+ --> $DIR/shared_at_top.rs:72:5
+ |
+LL | / if x == 11 {
+LL | | let can_be_overridden = "Move me";
+LL | | println!("I'm also moveable");
+ | |______________________________________^
+ |
- help: consider moving the start statements out like this
++ = warning: some moved values might need to be renamed to avoid wrong references
++help: consider moving these statements before the if
+ |
+LL ~ let can_be_overridden = "Move me";
+LL + println!("I'm also moveable");
+LL + if x == 11 {
+ |
+
+error: all if blocks contain the same code at the start
+ --> $DIR/shared_at_top.rs:88:5
+ |
+LL | / if x == 2020 {
+LL | | println!("This should trigger the `SHARED_CODE_IN_IF_BLOCKS` lint.");
+LL | | println!("Because `IF_SAME_THEN_ELSE` is allowed here");
+ | |________________________________________________________________^
+ |
++help: consider moving these statements before the if
+ |
+LL ~ println!("This should trigger the `SHARED_CODE_IN_IF_BLOCKS` lint.");
+LL + println!("Because `IF_SAME_THEN_ELSE` is allowed here");
+LL + if x == 2020 {
+ |
+
+error: this `if` has identical blocks
+ --> $DIR/shared_at_top.rs:96:18
+ |
+LL | if x == 2019 {
+ | __________________^
+LL | | println!("This should trigger `IS_SAME_THAN_ELSE` as usual");
+LL | | } else {
+ | |_____^
+ |
+note: the lint level is defined here
+ --> $DIR/shared_at_top.rs:2:9
+ |
+LL | #![deny(clippy::if_same_then_else, clippy::branches_sharing_code)]
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^
+note: same as this
+ --> $DIR/shared_at_top.rs:98:12
+ |
+LL | } else {
+ | ____________^
+LL | | println!("This should trigger `IS_SAME_THAN_ELSE` as usual");
+LL | | }
+ | |_____^
+
+error: aborting due to 7 previous errors
+
--- /dev/null
- error: all if blocks contain the same code at the start and the end. Here at the start
++error: all if blocks contain the same code at both the start and the end
+ --> $DIR/shared_at_top_and_bottom.rs:16:5
+ |
+LL | / if x == 7 {
+LL | | let t = 7;
+LL | | let _overlap_start = t * 2;
+LL | | let _overlap_end = 2 * t;
+ | |_________________________________^
+ |
+note: the lint level is defined here
+ --> $DIR/shared_at_top_and_bottom.rs:2:36
+ |
+LL | #![deny(clippy::if_same_then_else, clippy::branches_sharing_code)]
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- note: and here at the end
++note: this code is shared at the end
+ --> $DIR/shared_at_top_and_bottom.rs:28:5
+ |
+LL | / let _u = 9;
+LL | | }
+ | |_____^
- help: consider moving the start statements out like this
++help: consider moving these statements before the if
+ |
+LL ~ let t = 7;
+LL + let _overlap_start = t * 2;
+LL + let _overlap_end = 2 * t;
+LL + if x == 7 {
+ |
- help: and consider moving the end statements out like this
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL + let _u = 9;
+ |
+
- error: all if blocks contain the same code at the start and the end. Here at the start
++error: all if blocks contain the same code at both the start and the end
+ --> $DIR/shared_at_top_and_bottom.rs:32:5
+ |
+LL | / if x == 99 {
+LL | | let r = 7;
+LL | | let _overlap_start = r;
+LL | | let _overlap_middle = r * r;
+ | |____________________________________^
+ |
- note: and here at the end
++note: this code is shared at the end
+ --> $DIR/shared_at_top_and_bottom.rs:43:5
+ |
+LL | / let _overlap_end = r * r * r;
+LL | | let z = "end";
+LL | | }
+ | |_____^
- = warning: Some moved values might need to be renamed to avoid wrong references
- help: consider moving the start statements out like this
++ = warning: some moved values might need to be renamed to avoid wrong references
++help: consider moving these statements before the if
+ |
+LL ~ let r = 7;
+LL + let _overlap_start = r;
+LL + let _overlap_middle = r * r;
+LL + if x == 99 {
+ |
- help: and consider moving the end statements out like this
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL + let _overlap_end = r * r * r;
+LL + let z = "end";
+ |
+
- error: all if blocks contain the same code at the start and the end. Here at the start
++error: all if blocks contain the same code at both the start and the end
+ --> $DIR/shared_at_top_and_bottom.rs:61:5
+ |
+LL | / if (x > 7 && y < 13) || (x + y) % 2 == 1 {
+LL | | let a = 0xcafe;
+LL | | let b = 0xffff00ff;
+LL | | let e_id = gen_id(a, b);
+ | |________________________________^
+ |
- note: and here at the end
++note: this code is shared at the end
+ --> $DIR/shared_at_top_and_bottom.rs:81:5
+ |
+LL | / let pack = DataPack {
+LL | | id: e_id,
+LL | | name: "Player 1".to_string(),
+LL | | some_data: vec![0x12, 0x34, 0x56, 0x78, 0x90],
+LL | | };
+LL | | process_data(pack);
+LL | | }
+ | |_____^
- = warning: Some moved values might need to be renamed to avoid wrong references
- help: consider moving the start statements out like this
++ = warning: some moved values might need to be renamed to avoid wrong references
++help: consider moving these statements before the if
+ |
+LL ~ let a = 0xcafe;
+LL + let b = 0xffff00ff;
+LL + let e_id = gen_id(a, b);
+LL + if (x > 7 && y < 13) || (x + y) % 2 == 1 {
+ |
- help: and consider moving the end statements out like this
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL + let pack = DataPack {
+LL + id: e_id,
+LL + name: "Player 1".to_string(),
+LL + some_data: vec![0x12, 0x34, 0x56, 0x78, 0x90],
+LL + };
+ ...
+
- error: all if blocks contain the same code at the start and the end. Here at the start
++error: all if blocks contain the same code at both the start and the end
+ --> $DIR/shared_at_top_and_bottom.rs:94:5
+ |
+LL | / let _ = if x == 7 {
+LL | | let _ = 19;
+ | |___________________^
+ |
- note: and here at the end
++note: this code is shared at the end
+ --> $DIR/shared_at_top_and_bottom.rs:103:5
+ |
+LL | / x << 2
+LL | | };
+ | |_____^
- = note: The end suggestion probably needs some adjustments to use the expression result correctly
- help: consider moving the start statements out like this
++ = note: the end suggestion probably needs some adjustments to use the expression result correctly
++help: consider moving these statements before the if
+ |
+LL ~ let _ = 19;
+LL + let _ = if x == 7 {
+ |
- help: and consider moving the end statements out like this
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL ~ x << 2;
+ |
+
- error: all if blocks contain the same code at the start and the end. Here at the start
++error: all if blocks contain the same code at both the start and the end
+ --> $DIR/shared_at_top_and_bottom.rs:106:5
+ |
+LL | / if x == 9 {
+LL | | let _ = 17;
+ | |___________________^
+ |
- note: and here at the end
++note: this code is shared at the end
+ --> $DIR/shared_at_top_and_bottom.rs:115:5
+ |
+LL | / x * 4
+LL | | }
+ | |_____^
- = note: The end suggestion probably needs some adjustments to use the expression result correctly
- help: consider moving the start statements out like this
++ = note: the end suggestion probably needs some adjustments to use the expression result correctly
++help: consider moving these statements before the if
+ |
+LL ~ let _ = 17;
+LL + if x == 9 {
+ |
- help: and consider moving the end statements out like this
++help: consider moving these statements after the if
+ |
+LL ~ }
+LL + x * 4
+ |
+
+error: aborting due to 5 previous errors
+
--- /dev/null
+// run-rustfix
+
+#![allow(
+ clippy::cast_lossless,
+ // Int::max_value will be deprecated in the future
+ deprecated,
+)]
+#![warn(clippy::checked_conversions)]
+
+// Positive tests
+
+// Signed to unsigned
+
+pub fn i64_to_u32(value: i64) {
+ let _ = u32::try_from(value).is_ok();
+ let _ = u32::try_from(value).is_ok();
+}
+
+pub fn i64_to_u16(value: i64) {
+ let _ = u16::try_from(value).is_ok();
+ let _ = u16::try_from(value).is_ok();
+}
+
+pub fn isize_to_u8(value: isize) {
+ let _ = u8::try_from(value).is_ok();
+ let _ = u8::try_from(value).is_ok();
+}
+
+// Signed to signed
+
+pub fn i64_to_i32(value: i64) {
+ let _ = i32::try_from(value).is_ok();
+ let _ = i32::try_from(value).is_ok();
+}
+
+pub fn i64_to_i16(value: i64) {
+ let _ = i16::try_from(value).is_ok();
+ let _ = i16::try_from(value).is_ok();
+}
+
+// Unsigned to X
+
+pub fn u32_to_i32(value: u32) {
+ let _ = i32::try_from(value).is_ok();
+ let _ = i32::try_from(value).is_ok();
+}
+
+pub fn usize_to_isize(value: usize) {
+ let _ = isize::try_from(value).is_ok() && value as i32 == 5;
+ let _ = isize::try_from(value).is_ok() && value as i32 == 5;
+}
+
+pub fn u32_to_u16(value: u32) {
+ let _ = u16::try_from(value).is_ok() && value as i32 == 5;
+ let _ = u16::try_from(value).is_ok() && value as i32 == 5;
+}
+
+// Negative tests
+
+pub fn no_i64_to_i32(value: i64) {
+ let _ = value <= (i32::max_value() as i64) && value >= 0;
+ let _ = value <= (i32::MAX as i64) && value >= 0;
+}
+
+pub fn no_isize_to_u8(value: isize) {
+ let _ = value <= (u8::max_value() as isize) && value >= (u8::min_value() as isize);
+ let _ = value <= (u8::MAX as isize) && value >= (u8::MIN as isize);
+}
+
+pub fn i8_to_u8(value: i8) {
+ let _ = value >= 0;
+}
+
++// Do not lint
++pub const fn issue_8898(i: u32) -> bool {
++ i <= i32::MAX as u32
++}
++
+fn main() {}
--- /dev/null
+// run-rustfix
+
+#![allow(
+ clippy::cast_lossless,
+ // Int::max_value will be deprecated in the future
+ deprecated,
+)]
+#![warn(clippy::checked_conversions)]
+
+// Positive tests
+
+// Signed to unsigned
+
+pub fn i64_to_u32(value: i64) {
+ let _ = value <= (u32::max_value() as i64) && value >= 0;
+ let _ = value <= (u32::MAX as i64) && value >= 0;
+}
+
+pub fn i64_to_u16(value: i64) {
+ let _ = value <= i64::from(u16::max_value()) && value >= 0;
+ let _ = value <= i64::from(u16::MAX) && value >= 0;
+}
+
+pub fn isize_to_u8(value: isize) {
+ let _ = value <= (u8::max_value() as isize) && value >= 0;
+ let _ = value <= (u8::MAX as isize) && value >= 0;
+}
+
+// Signed to signed
+
+pub fn i64_to_i32(value: i64) {
+ let _ = value <= (i32::max_value() as i64) && value >= (i32::min_value() as i64);
+ let _ = value <= (i32::MAX as i64) && value >= (i32::MIN as i64);
+}
+
+pub fn i64_to_i16(value: i64) {
+ let _ = value <= i64::from(i16::max_value()) && value >= i64::from(i16::min_value());
+ let _ = value <= i64::from(i16::MAX) && value >= i64::from(i16::MIN);
+}
+
+// Unsigned to X
+
+pub fn u32_to_i32(value: u32) {
+ let _ = value <= i32::max_value() as u32;
+ let _ = value <= i32::MAX as u32;
+}
+
+pub fn usize_to_isize(value: usize) {
+ let _ = value <= isize::max_value() as usize && value as i32 == 5;
+ let _ = value <= isize::MAX as usize && value as i32 == 5;
+}
+
+pub fn u32_to_u16(value: u32) {
+ let _ = value <= u16::max_value() as u32 && value as i32 == 5;
+ let _ = value <= u16::MAX as u32 && value as i32 == 5;
+}
+
+// Negative tests
+
+pub fn no_i64_to_i32(value: i64) {
+ let _ = value <= (i32::max_value() as i64) && value >= 0;
+ let _ = value <= (i32::MAX as i64) && value >= 0;
+}
+
+pub fn no_isize_to_u8(value: isize) {
+ let _ = value <= (u8::max_value() as isize) && value >= (u8::min_value() as isize);
+ let _ = value <= (u8::MAX as isize) && value >= (u8::MIN as isize);
+}
+
+pub fn i8_to_u8(value: i8) {
+ let _ = value >= 0;
+}
+
++// Do not lint
++pub const fn issue_8898(i: u32) -> bool {
++ i <= i32::MAX as u32
++}
++
+fn main() {}
--- /dev/null
+// run-rustfix
+// aux-build:macro_rules.rs
+
++#![feature(lint_reasons)]
+#![warn(clippy::default_numeric_fallback)]
+#![allow(
+ unused,
+ clippy::never_loop,
+ clippy::no_effect,
+ clippy::unnecessary_operation,
+ clippy::branches_sharing_code,
+ clippy::let_unit_value
+)]
+
+#[macro_use]
+extern crate macro_rules;
+
+mod basic_expr {
+ fn test() {
+ // Should lint unsuffixed literals typed `i32`.
+ let x = 22_i32;
+ let x = [1_i32, 2_i32, 3_i32];
+ let x = if true { (1_i32, 2_i32) } else { (3_i32, 4_i32) };
+ let x = match 1_i32 {
+ 1_i32 => 1_i32,
+ _ => 2_i32,
+ };
+
+ // Should NOT lint suffixed literals.
+ let x = 22_i32;
+
+ // Should NOT lint literals in init expr if `Local` has a type annotation.
+ let x: [i32; 3] = [1, 2, 3];
+ let x: (i32, i32) = if true { (1, 2) } else { (3, 4) };
+ let x: _ = 1;
+ }
+}
+
+mod nested_local {
+ fn test() {
+ let x: _ = {
+ // Should lint this because this literal is not bound to any types.
+ let y = 1_i32;
+
+ // Should NOT lint this because this literal is bound to `_` of outer `Local`.
+ 1
+ };
+
+ let x: _ = if true {
+ // Should lint this because this literal is not bound to any types.
+ let y = 1_i32;
+
+ // Should NOT lint this because this literal is bound to `_` of outer `Local`.
+ 1
+ } else {
+ // Should lint this because this literal is not bound to any types.
+ let y = 1_i32;
+
+ // Should NOT lint this because this literal is bound to `_` of outer `Local`.
+ 2
+ };
+ }
+}
+
+mod function_def {
+ fn ret_i32() -> i32 {
+ // Even though the output type is specified,
+ // this unsuffixed literal is linted to reduce heuristics and keep codebase simple.
+ 1_i32
+ }
+
+ fn test() {
+ // Should lint this because return type is inferred to `i32` and NOT bound to a concrete
+ // type.
+ let f = || -> _ { 1_i32 };
+
+ // Even though the output type is specified,
+ // this unsuffixed literal is linted to reduce heuristics and keep codebase simple.
+ let f = || -> i32 { 1_i32 };
+ }
+}
+
+mod function_calls {
+ fn concrete_arg(x: i32) {}
+
+ fn generic_arg<T>(t: T) {}
+
+ fn test() {
+ // Should NOT lint this because the argument type is bound to a concrete type.
+ concrete_arg(1);
+
+ // Should lint this because the argument type is inferred to `i32` and NOT bound to a concrete type.
+ generic_arg(1_i32);
+
+ // Should lint this because the argument type is inferred to `i32` and NOT bound to a concrete type.
+ let x: _ = generic_arg(1_i32);
+ }
+}
+
+mod struct_ctor {
+ struct ConcreteStruct {
+ x: i32,
+ }
+
+ struct GenericStruct<T> {
+ x: T,
+ }
+
+ fn test() {
+ // Should NOT lint this because the field type is bound to a concrete type.
+ ConcreteStruct { x: 1 };
+
+ // Should lint this because the field type is inferred to `i32` and NOT bound to a concrete type.
+ GenericStruct { x: 1_i32 };
+
+ // Should lint this because the field type is inferred to `i32` and NOT bound to a concrete type.
+ let _ = GenericStruct { x: 1_i32 };
+ }
+}
+
+mod enum_ctor {
+ enum ConcreteEnum {
+ X(i32),
+ }
+
+ enum GenericEnum<T> {
+ X(T),
+ }
+
+ fn test() {
+ // Should NOT lint this because the field type is bound to a concrete type.
+ ConcreteEnum::X(1);
+
+ // Should lint this because the field type is inferred to `i32` and NOT bound to a concrete type.
+ GenericEnum::X(1_i32);
+ }
+}
+
+mod method_calls {
+ struct StructForMethodCallTest;
+
+ impl StructForMethodCallTest {
+ fn concrete_arg(&self, x: i32) {}
+
+ fn generic_arg<T>(&self, t: T) {}
+ }
+
+ fn test() {
+ let s = StructForMethodCallTest {};
+
+ // Should NOT lint this because the argument type is bound to a concrete type.
+ s.concrete_arg(1);
+
+ // Should lint this because the argument type is bound to a concrete type.
+ s.generic_arg(1_i32);
+ }
+}
+
+mod in_macro {
+ macro_rules! internal_macro {
+ () => {
+ let x = 22_i32;
+ };
+ }
+
+ // Should lint in internal macro.
+ fn internal() {
+ internal_macro!();
+ }
+
+ // Should NOT lint in external macro.
+ fn external() {
+ default_numeric_fallback!();
+ }
+}
+
++fn check_expect_suppression() {
++ #[expect(clippy::default_numeric_fallback)]
++ let x = 21;
++}
++
+fn main() {}
--- /dev/null
+// run-rustfix
+// aux-build:macro_rules.rs
+
++#![feature(lint_reasons)]
+#![warn(clippy::default_numeric_fallback)]
+#![allow(
+ unused,
+ clippy::never_loop,
+ clippy::no_effect,
+ clippy::unnecessary_operation,
+ clippy::branches_sharing_code,
+ clippy::let_unit_value
+)]
+
+#[macro_use]
+extern crate macro_rules;
+
+mod basic_expr {
+ fn test() {
+ // Should lint unsuffixed literals typed `i32`.
+ let x = 22;
+ let x = [1, 2, 3];
+ let x = if true { (1, 2) } else { (3, 4) };
+ let x = match 1 {
+ 1 => 1,
+ _ => 2,
+ };
+
+ // Should NOT lint suffixed literals.
+ let x = 22_i32;
+
+ // Should NOT lint literals in init expr if `Local` has a type annotation.
+ let x: [i32; 3] = [1, 2, 3];
+ let x: (i32, i32) = if true { (1, 2) } else { (3, 4) };
+ let x: _ = 1;
+ }
+}
+
+mod nested_local {
+ fn test() {
+ let x: _ = {
+ // Should lint this because this literal is not bound to any types.
+ let y = 1;
+
+ // Should NOT lint this because this literal is bound to `_` of outer `Local`.
+ 1
+ };
+
+ let x: _ = if true {
+ // Should lint this because this literal is not bound to any types.
+ let y = 1;
+
+ // Should NOT lint this because this literal is bound to `_` of outer `Local`.
+ 1
+ } else {
+ // Should lint this because this literal is not bound to any types.
+ let y = 1;
+
+ // Should NOT lint this because this literal is bound to `_` of outer `Local`.
+ 2
+ };
+ }
+}
+
+mod function_def {
+ fn ret_i32() -> i32 {
+ // Even though the output type is specified,
+ // this unsuffixed literal is linted to reduce heuristics and keep codebase simple.
+ 1
+ }
+
+ fn test() {
+ // Should lint this because return type is inferred to `i32` and NOT bound to a concrete
+ // type.
+ let f = || -> _ { 1 };
+
+ // Even though the output type is specified,
+ // this unsuffixed literal is linted to reduce heuristics and keep codebase simple.
+ let f = || -> i32 { 1 };
+ }
+}
+
+mod function_calls {
+ fn concrete_arg(x: i32) {}
+
+ fn generic_arg<T>(t: T) {}
+
+ fn test() {
+ // Should NOT lint this because the argument type is bound to a concrete type.
+ concrete_arg(1);
+
+ // Should lint this because the argument type is inferred to `i32` and NOT bound to a concrete type.
+ generic_arg(1);
+
+ // Should lint this because the argument type is inferred to `i32` and NOT bound to a concrete type.
+ let x: _ = generic_arg(1);
+ }
+}
+
+mod struct_ctor {
+ struct ConcreteStruct {
+ x: i32,
+ }
+
+ struct GenericStruct<T> {
+ x: T,
+ }
+
+ fn test() {
+ // Should NOT lint this because the field type is bound to a concrete type.
+ ConcreteStruct { x: 1 };
+
+ // Should lint this because the field type is inferred to `i32` and NOT bound to a concrete type.
+ GenericStruct { x: 1 };
+
+ // Should lint this because the field type is inferred to `i32` and NOT bound to a concrete type.
+ let _ = GenericStruct { x: 1 };
+ }
+}
+
+mod enum_ctor {
+ enum ConcreteEnum {
+ X(i32),
+ }
+
+ enum GenericEnum<T> {
+ X(T),
+ }
+
+ fn test() {
+ // Should NOT lint this because the field type is bound to a concrete type.
+ ConcreteEnum::X(1);
+
+ // Should lint this because the field type is inferred to `i32` and NOT bound to a concrete type.
+ GenericEnum::X(1);
+ }
+}
+
+mod method_calls {
+ struct StructForMethodCallTest;
+
+ impl StructForMethodCallTest {
+ fn concrete_arg(&self, x: i32) {}
+
+ fn generic_arg<T>(&self, t: T) {}
+ }
+
+ fn test() {
+ let s = StructForMethodCallTest {};
+
+ // Should NOT lint this because the argument type is bound to a concrete type.
+ s.concrete_arg(1);
+
+ // Should lint this because the argument type is bound to a concrete type.
+ s.generic_arg(1);
+ }
+}
+
+mod in_macro {
+ macro_rules! internal_macro {
+ () => {
+ let x = 22;
+ };
+ }
+
+ // Should lint in internal macro.
+ fn internal() {
+ internal_macro!();
+ }
+
+ // Should NOT lint in external macro.
+ fn external() {
+ default_numeric_fallback!();
+ }
+}
+
++fn check_expect_suppression() {
++ #[expect(clippy::default_numeric_fallback)]
++ let x = 21;
++}
++
+fn main() {}
--- /dev/null
- --> $DIR/default_numeric_fallback_i32.rs:20:17
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:21:18
++ --> $DIR/default_numeric_fallback_i32.rs:21:17
+ |
+LL | let x = 22;
+ | ^^ help: consider adding suffix: `22_i32`
+ |
+ = note: `-D clippy::default-numeric-fallback` implied by `-D warnings`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:21:21
++ --> $DIR/default_numeric_fallback_i32.rs:22:18
+ |
+LL | let x = [1, 2, 3];
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:21:24
++ --> $DIR/default_numeric_fallback_i32.rs:22:21
+ |
+LL | let x = [1, 2, 3];
+ | ^ help: consider adding suffix: `2_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:22:28
++ --> $DIR/default_numeric_fallback_i32.rs:22:24
+ |
+LL | let x = [1, 2, 3];
+ | ^ help: consider adding suffix: `3_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:22:31
++ --> $DIR/default_numeric_fallback_i32.rs:23:28
+ |
+LL | let x = if true { (1, 2) } else { (3, 4) };
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:22:44
++ --> $DIR/default_numeric_fallback_i32.rs:23:31
+ |
+LL | let x = if true { (1, 2) } else { (3, 4) };
+ | ^ help: consider adding suffix: `2_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:22:47
++ --> $DIR/default_numeric_fallback_i32.rs:23:44
+ |
+LL | let x = if true { (1, 2) } else { (3, 4) };
+ | ^ help: consider adding suffix: `3_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:23:23
++ --> $DIR/default_numeric_fallback_i32.rs:23:47
+ |
+LL | let x = if true { (1, 2) } else { (3, 4) };
+ | ^ help: consider adding suffix: `4_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:24:13
++ --> $DIR/default_numeric_fallback_i32.rs:24:23
+ |
+LL | let x = match 1 {
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:24:18
++ --> $DIR/default_numeric_fallback_i32.rs:25:13
+ |
+LL | 1 => 1,
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:25:18
++ --> $DIR/default_numeric_fallback_i32.rs:25:18
+ |
+LL | 1 => 1,
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:42:21
++ --> $DIR/default_numeric_fallback_i32.rs:26:18
+ |
+LL | _ => 2,
+ | ^ help: consider adding suffix: `2_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:50:21
++ --> $DIR/default_numeric_fallback_i32.rs:43:21
+ |
+LL | let y = 1;
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:56:21
++ --> $DIR/default_numeric_fallback_i32.rs:51:21
+ |
+LL | let y = 1;
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:68:9
++ --> $DIR/default_numeric_fallback_i32.rs:57:21
+ |
+LL | let y = 1;
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:74:27
++ --> $DIR/default_numeric_fallback_i32.rs:69:9
+ |
+LL | 1
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:78:29
++ --> $DIR/default_numeric_fallback_i32.rs:75:27
+ |
+LL | let f = || -> _ { 1 };
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:92:21
++ --> $DIR/default_numeric_fallback_i32.rs:79:29
+ |
+LL | let f = || -> i32 { 1 };
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:95:32
++ --> $DIR/default_numeric_fallback_i32.rs:93:21
+ |
+LL | generic_arg(1);
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:113:28
++ --> $DIR/default_numeric_fallback_i32.rs:96:32
+ |
+LL | let x: _ = generic_arg(1);
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:116:36
++ --> $DIR/default_numeric_fallback_i32.rs:114:28
+ |
+LL | GenericStruct { x: 1 };
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:134:24
++ --> $DIR/default_numeric_fallback_i32.rs:117:36
+ |
+LL | let _ = GenericStruct { x: 1 };
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:154:23
++ --> $DIR/default_numeric_fallback_i32.rs:135:24
+ |
+LL | GenericEnum::X(1);
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
- --> $DIR/default_numeric_fallback_i32.rs:161:21
++ --> $DIR/default_numeric_fallback_i32.rs:155:23
+ |
+LL | s.generic_arg(1);
+ | ^ help: consider adding suffix: `1_i32`
+
+error: default numeric fallback might occur
++ --> $DIR/default_numeric_fallback_i32.rs:162:21
+ |
+LL | let x = 22;
+ | ^^ help: consider adding suffix: `22_i32`
+...
+LL | internal_macro!();
+ | ----------------- in this macro invocation
+ |
+ = note: this error originates in the macro `internal_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 25 previous errors
+
--- /dev/null
- struct NotPartialEq {
+// run-rustfix
+
+#![allow(unused)]
+#![warn(clippy::derive_partial_eq_without_eq)]
+
+// Don't warn on structs that aren't PartialEq
- struct MissingEq {
++pub struct NotPartialEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq can be derived but is missing
+#[derive(Debug, PartialEq, Eq)]
- struct NotMissingEq {
++pub struct MissingEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq is derived
+#[derive(PartialEq, Eq)]
- struct ManualEqImpl {
++pub struct NotMissingEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq is manually implemented
+#[derive(PartialEq)]
- struct CannotBeEq {
++pub struct ManualEqImpl {
+ foo: u32,
+ bar: String,
+}
+
+impl Eq for ManualEqImpl {}
+
+// Cannot be Eq because f32 isn't Eq
+#[derive(PartialEq)]
- struct ManualPartialEqImpl {
++pub struct CannotBeEq {
+ foo: u32,
+ bar: f32,
+}
+
+// Don't warn if PartialEq is manually implemented
- #[derive(PartialEq)]
- struct GenericNotEq<T: Eq, U: PartialEq> {
++pub 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
- struct GenericEq<T: Eq, U: Eq> {
++#[derive(PartialEq, Eq)]
++pub struct GenericNotEq<T: Eq, U: PartialEq> {
+ foo: T,
+ bar: U,
+}
+
+#[derive(PartialEq, Eq)]
- struct TupleStruct(u32);
++pub struct GenericEq<T: Eq, U: Eq> {
+ foo: T,
+ bar: U,
+}
+
+#[derive(PartialEq, Eq)]
- struct GenericTupleStruct<T: Eq>(T);
++pub struct TupleStruct(u32);
+
+#[derive(PartialEq, Eq)]
- struct TupleStructNotEq(f32);
++pub struct GenericTupleStruct<T: Eq>(T);
+
+#[derive(PartialEq)]
- enum Enum {
++pub struct TupleStructNotEq(f32);
+
+#[derive(PartialEq, Eq)]
- enum GenericEnum<T: Eq, U: Eq, V: Eq> {
++pub enum Enum {
+ Foo(u32),
+ Bar { a: String, b: () },
+}
+
+#[derive(PartialEq, Eq)]
- enum EnumNotEq {
++pub enum GenericEnum<T: Eq, U: Eq, V: Eq> {
+ Foo(T),
+ Bar { a: U, b: V },
+}
+
+#[derive(PartialEq)]
- struct RustFixWithOtherDerives;
++pub 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)]
- #[derive(PartialEq)]
- struct Generic<T>(T);
++pub struct RustFixWithOtherDerives;
+
- struct GenericPhantom<T>(core::marker::PhantomData<T>);
++#[derive(PartialEq, Eq)]
++pub struct Generic<T>(T);
+
+#[derive(PartialEq, Eq)]
++pub struct GenericPhantom<T>(core::marker::PhantomData<T>);
++
++mod _hidden {
++ #[derive(PartialEq, Eq)]
++ pub struct Reexported;
++
++ #[derive(PartialEq, Eq)]
++ pub struct InPubFn;
++
++ #[derive(PartialEq)]
++ pub(crate) struct PubCrate;
++
++ #[derive(PartialEq)]
++ pub(super) struct PubSuper;
++}
++
++pub use _hidden::Reexported;
++pub fn _from_mod() -> _hidden::InPubFn {
++ _hidden::InPubFn
++}
++
++#[derive(PartialEq)]
++struct InternalTy;
+
+fn main() {}
--- /dev/null
- struct NotPartialEq {
+// run-rustfix
+
+#![allow(unused)]
+#![warn(clippy::derive_partial_eq_without_eq)]
+
+// Don't warn on structs that aren't PartialEq
- struct MissingEq {
++pub struct NotPartialEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq can be derived but is missing
+#[derive(Debug, PartialEq)]
- struct NotMissingEq {
++pub struct MissingEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq is derived
+#[derive(PartialEq, Eq)]
- struct ManualEqImpl {
++pub struct NotMissingEq {
+ foo: u32,
+ bar: String,
+}
+
+// Eq is manually implemented
+#[derive(PartialEq)]
- struct CannotBeEq {
++pub struct ManualEqImpl {
+ foo: u32,
+ bar: String,
+}
+
+impl Eq for ManualEqImpl {}
+
+// Cannot be Eq because f32 isn't Eq
+#[derive(PartialEq)]
- struct ManualPartialEqImpl {
++pub struct CannotBeEq {
+ foo: u32,
+ bar: f32,
+}
+
+// Don't warn if PartialEq is manually implemented
- struct GenericNotEq<T: Eq, U: PartialEq> {
++pub 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 GenericEq<T: Eq, U: Eq> {
++pub struct GenericNotEq<T: Eq, U: PartialEq> {
+ foo: T,
+ bar: U,
+}
+
+#[derive(PartialEq)]
- struct TupleStruct(u32);
++pub struct GenericEq<T: Eq, U: Eq> {
+ foo: T,
+ bar: U,
+}
+
+#[derive(PartialEq)]
- struct GenericTupleStruct<T: Eq>(T);
++pub struct TupleStruct(u32);
+
+#[derive(PartialEq)]
- struct TupleStructNotEq(f32);
++pub struct GenericTupleStruct<T: Eq>(T);
+
+#[derive(PartialEq)]
- enum Enum {
++pub struct TupleStructNotEq(f32);
+
+#[derive(PartialEq)]
- enum GenericEnum<T: Eq, U: Eq, V: Eq> {
++pub enum Enum {
+ Foo(u32),
+ Bar { a: String, b: () },
+}
+
+#[derive(PartialEq)]
- enum EnumNotEq {
++pub enum GenericEnum<T: Eq, U: Eq, V: Eq> {
+ Foo(T),
+ Bar { a: U, b: V },
+}
+
+#[derive(PartialEq)]
- struct RustFixWithOtherDerives;
++pub 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 Generic<T>(T);
++pub struct RustFixWithOtherDerives;
+
+#[derive(PartialEq)]
- struct GenericPhantom<T>(core::marker::PhantomData<T>);
++pub struct Generic<T>(T);
+
+#[derive(PartialEq, Eq)]
++pub struct GenericPhantom<T>(core::marker::PhantomData<T>);
++
++mod _hidden {
++ #[derive(PartialEq)]
++ pub struct Reexported;
++
++ #[derive(PartialEq)]
++ pub struct InPubFn;
++
++ #[derive(PartialEq)]
++ pub(crate) struct PubCrate;
++
++ #[derive(PartialEq)]
++ pub(super) struct PubSuper;
++}
++
++pub use _hidden::Reexported;
++pub fn _from_mod() -> _hidden::InPubFn {
++ _hidden::InPubFn
++}
++
++#[derive(PartialEq)]
++struct InternalTy;
+
+fn main() {}
--- /dev/null
- error: aborting due to 7 previous errors
+error: you are deriving `PartialEq` and can implement `Eq`
+ --> $DIR/derive_partial_eq_without_eq.rs:13:17
+ |
+LL | #[derive(Debug, PartialEq)]
+ | ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
+ |
+ = note: `-D clippy::derive-partial-eq-without-eq` implied by `-D warnings`
+
++error: you are deriving `PartialEq` and can implement `Eq`
++ --> $DIR/derive_partial_eq_without_eq.rs:55:10
++ |
++LL | #[derive(PartialEq)]
++ | ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
++
+error: you are deriving `PartialEq` and can implement `Eq`
+ --> $DIR/derive_partial_eq_without_eq.rs:61:10
+ |
+LL | #[derive(PartialEq)]
+ | ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
+
+error: you are deriving `PartialEq` and can implement `Eq`
+ --> $DIR/derive_partial_eq_without_eq.rs:67:10
+ |
+LL | #[derive(PartialEq)]
+ | ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
+
+error: you are deriving `PartialEq` and can implement `Eq`
+ --> $DIR/derive_partial_eq_without_eq.rs:70:10
+ |
+LL | #[derive(PartialEq)]
+ | ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
+
+error: you are deriving `PartialEq` and can implement `Eq`
+ --> $DIR/derive_partial_eq_without_eq.rs:76:10
+ |
+LL | #[derive(PartialEq)]
+ | ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
+
+error: you are deriving `PartialEq` and can implement `Eq`
+ --> $DIR/derive_partial_eq_without_eq.rs:82:10
+ |
+LL | #[derive(PartialEq)]
+ | ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
+
+error: you are deriving `PartialEq` and can implement `Eq`
+ --> $DIR/derive_partial_eq_without_eq.rs:95:17
+ |
+LL | #[derive(Debug, PartialEq, Clone)]
+ | ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
+
++error: you are deriving `PartialEq` and can implement `Eq`
++ --> $DIR/derive_partial_eq_without_eq.rs:98:10
++ |
++LL | #[derive(PartialEq)]
++ | ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
++
++error: you are deriving `PartialEq` and can implement `Eq`
++ --> $DIR/derive_partial_eq_without_eq.rs:105:14
++ |
++LL | #[derive(PartialEq)]
++ | ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
++
++error: you are deriving `PartialEq` and can implement `Eq`
++ --> $DIR/derive_partial_eq_without_eq.rs:108:14
++ |
++LL | #[derive(PartialEq)]
++ | ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
++
++error: aborting due to 11 previous errors
+
--- /dev/null
+// run-rustfix
+
+#![allow(
+ unused,
+ clippy::no_effect,
+ clippy::redundant_closure_call,
+ clippy::needless_pass_by_value,
+ clippy::option_map_unit_fn,
+ clippy::needless_borrow
+)]
+#![warn(clippy::redundant_closure, clippy::redundant_closure_for_method_calls)]
+
+use std::path::{Path, PathBuf};
+
+macro_rules! mac {
+ () => {
+ foobar()
+ };
+}
+
+macro_rules! closure_mac {
+ () => {
+ |n| foo(n)
+ };
+}
+
+fn main() {
+ let a = Some(1u8).map(foo);
+ let c = Some(1u8).map(|a| {1+2; foo}(a));
+ true.then(|| mac!()); // don't lint function in macro expansion
+ Some(1).map(closure_mac!()); // don't lint closure in macro expansion
+ let _: Option<Vec<u8>> = true.then(std::vec::Vec::new); // special case vec!
+ let d = Some(1u8).map(|a| foo(foo2(a))); //is adjusted?
+ all(&[1, 2, 3], &&2, below); //is adjusted
+ unsafe {
+ Some(1u8).map(|a| unsafe_fn(a)); // unsafe fn
+ }
+
+ // See #815
+ let e = Some(1u8).map(|a| divergent(a));
+ let e = Some(1u8).map(generic);
+ let e = Some(1u8).map(generic);
+ // See #515
+ let a: Option<Box<dyn (::std::ops::Deref<Target = [i32]>)>> =
+ Some(vec![1i32, 2]).map(|v| -> Box<dyn (::std::ops::Deref<Target = [i32]>)> { Box::new(v) });
+
+ // issue #7224
+ let _: Option<Vec<u32>> = Some(0).map(|_| vec![]);
+}
+
+trait TestTrait {
+ fn trait_foo(self) -> bool;
+ fn trait_foo_ref(&self) -> bool;
+}
+
+struct TestStruct<'a> {
+ some_ref: &'a i32,
+}
+
+impl<'a> TestStruct<'a> {
+ fn foo(self) -> bool {
+ false
+ }
+ unsafe fn foo_unsafe(self) -> bool {
+ true
+ }
+}
+
+impl<'a> TestTrait for TestStruct<'a> {
+ fn trait_foo(self) -> bool {
+ false
+ }
+ fn trait_foo_ref(&self) -> bool {
+ false
+ }
+}
+
+impl<'a> std::ops::Deref for TestStruct<'a> {
+ type Target = char;
+ fn deref(&self) -> &char {
+ &'a'
+ }
+}
+
+fn test_redundant_closures_containing_method_calls() {
+ let i = 10;
+ let e = Some(TestStruct { some_ref: &i }).map(TestStruct::foo);
+ let e = Some(TestStruct { some_ref: &i }).map(TestTrait::trait_foo);
+ let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo_ref());
+ let e = Some(&mut vec![1, 2, 3]).map(std::vec::Vec::clear);
+ unsafe {
+ let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo_unsafe());
+ }
+ let e = Some("str").map(std::string::ToString::to_string);
+ let e = Some('a').map(char::to_uppercase);
+ let e: std::vec::Vec<usize> = vec!['a', 'b', 'c'].iter().map(|c| c.len_utf8()).collect();
+ let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(char::to_ascii_uppercase).collect();
+ let e = Some(PathBuf::new()).as_ref().and_then(|s| s.to_str());
+ let c = Some(TestStruct { some_ref: &i })
+ .as_ref()
+ .map(|c| c.to_ascii_uppercase());
+
+ fn test_different_borrow_levels<T>(t: &[&T])
+ where
+ T: TestTrait,
+ {
+ t.iter().filter(|x| x.trait_foo_ref());
+ t.iter().map(|x| x.trait_foo_ref());
+ }
+}
+
+struct Thunk<T>(Box<dyn FnMut() -> T>);
+
+impl<T> Thunk<T> {
+ fn new<F: 'static + FnOnce() -> T>(f: F) -> Thunk<T> {
+ let mut option = Some(f);
+ // This should not trigger redundant_closure (#1439)
+ Thunk(Box::new(move || option.take().unwrap()()))
+ }
+
+ fn unwrap(self) -> T {
+ let Thunk(mut f) = self;
+ f()
+ }
+}
+
+fn foobar() {
+ let thunk = Thunk::new(|| println!("Hello, world!"));
+ thunk.unwrap()
+}
+
+fn foo(_: u8) {}
+
+fn foo2(_: u8) -> u8 {
+ 1u8
+}
+
+fn all<X, F>(x: &[X], y: &X, f: F) -> bool
+where
+ F: Fn(&X, &X) -> bool,
+{
+ x.iter().all(|e| f(e, y))
+}
+
+fn below(x: &u8, y: &u8) -> bool {
+ x < y
+}
+
+unsafe fn unsafe_fn(_: u8) {}
+
+fn divergent(_: u8) -> ! {
+ unimplemented!()
+}
+
+fn generic<T>(_: T) -> u8 {
+ 0
+}
+
+fn passes_fn_mut(mut x: Box<dyn FnMut()>) {
+ requires_fn_once(x);
+}
+fn requires_fn_once<T: FnOnce()>(_: T) {}
+
+fn test_redundant_closure_with_function_pointer() {
+ type FnPtrType = fn(u8);
+ let foo_ptr: FnPtrType = foo;
+ let a = Some(1u8).map(foo_ptr);
+}
+
+fn test_redundant_closure_with_another_closure() {
+ let closure = |a| println!("{}", a);
+ let a = Some(1u8).map(closure);
+}
+
+fn make_lazy(f: impl Fn() -> fn(u8) -> u8) -> impl Fn(u8) -> u8 {
+ // Currently f is called when result of make_lazy is called.
+ // If the closure is removed, f will be called when make_lazy itself is
+ // called. This changes semantics, so the closure must stay.
+ Box::new(move |x| f()(x))
+}
+
+fn call<F: FnOnce(&mut String) -> String>(f: F) -> String {
+ f(&mut "Hello".to_owned())
+}
+fn test_difference_in_mutability() {
+ call(|s| s.clone());
+}
+
+struct Bar;
+impl std::ops::Deref for Bar {
+ type Target = str;
+ fn deref(&self) -> &str {
+ "hi"
+ }
+}
+
+fn test_deref_with_trait_method() {
+ let _ = [Bar].iter().map(|s| s.to_string()).collect::<Vec<_>>();
+}
+
+fn mutable_closure_used_again(x: Vec<i32>, y: Vec<i32>, z: Vec<i32>) {
+ let mut res = Vec::new();
+ let mut add_to_res = |n| res.push(n);
+ x.into_iter().for_each(&mut add_to_res);
+ y.into_iter().for_each(&mut add_to_res);
+ z.into_iter().for_each(add_to_res);
+}
+
+fn mutable_closure_in_loop() {
+ let mut value = 0;
+ let mut closure = |n| value += n;
+ for _ in 0..5 {
+ Some(1).map(&mut closure);
+
+ let mut value = 0;
+ let mut in_loop = |n| value += n;
+ Some(1).map(in_loop);
+ }
+}
+
+fn late_bound_lifetimes() {
+ fn take_asref_path<P: AsRef<Path>>(path: P) {}
+
+ fn map_str<F>(thunk: F)
+ where
+ F: FnOnce(&str),
+ {
+ }
+
+ fn map_str_to_path<F>(thunk: F)
+ where
+ F: FnOnce(&str) -> &Path,
+ {
+ }
+ map_str(|s| take_asref_path(s));
+ map_str_to_path(|s| s.as_ref());
+}
+
+mod type_param_bound {
+ trait Trait {
+ fn fun();
+ }
+
+ fn take<T: 'static>(_: T) {}
+
+ fn test<X: Trait>() {
+ // don't lint, but it's questionable that rust requires a cast
+ take(|| X::fun());
+ take(X::fun as fn());
+ }
+}
+
+// #8073 Don't replace closure with `Arc<F>` or `Rc<F>`
+fn arc_fp() {
+ let rc = std::rc::Rc::new(|| 7);
+ let arc = std::sync::Arc::new(|n| n + 1);
+ let ref_arc = &std::sync::Arc::new(|_| 5);
+
+ true.then(|| rc());
+ (0..5).map(|n| arc(n));
+ Some(4).map(|n| ref_arc(n));
+}
+
+// #8460 Don't replace closures with params bounded as `ref`
+mod bind_by_ref {
+ struct A;
+ struct B;
+
+ impl From<&A> for B {
+ fn from(A: &A) -> Self {
+ B
+ }
+ }
+
+ fn test() {
+ // should not lint
+ Some(A).map(|a| B::from(&a));
+ // should not lint
+ Some(A).map(|ref a| B::from(a));
+ }
+}
+
+// #7812 False positive on coerced closure
+fn coerced_closure() {
+ fn function_returning_unit<F: FnMut(i32)>(f: F) {}
+ function_returning_unit(|x| std::process::exit(x));
+
+ fn arr() -> &'static [u8; 0] {
+ &[]
+ }
+ fn slice_fn(_: impl FnOnce() -> &'static [u8]) {}
+ slice_fn(|| arr());
+}
++
++// https://github.com/rust-lang/rust-clippy/issues/7861
++fn box_dyn() {
++ fn f(_: impl Fn(usize) -> Box<dyn std::any::Any>) {}
++ f(|x| Box::new(x));
++}
++
++// https://github.com/rust-lang/rust-clippy/issues/5939
++fn not_general_enough() {
++ fn f(_: impl FnMut(&Path) -> std::io::Result<()>) {}
++ f(|path| std::fs::remove_file(path));
++}
--- /dev/null
+// run-rustfix
+
+#![allow(
+ unused,
+ clippy::no_effect,
+ clippy::redundant_closure_call,
+ clippy::needless_pass_by_value,
+ clippy::option_map_unit_fn,
+ clippy::needless_borrow
+)]
+#![warn(clippy::redundant_closure, clippy::redundant_closure_for_method_calls)]
+
+use std::path::{Path, PathBuf};
+
+macro_rules! mac {
+ () => {
+ foobar()
+ };
+}
+
+macro_rules! closure_mac {
+ () => {
+ |n| foo(n)
+ };
+}
+
+fn main() {
+ let a = Some(1u8).map(|a| foo(a));
+ let c = Some(1u8).map(|a| {1+2; foo}(a));
+ true.then(|| mac!()); // don't lint function in macro expansion
+ Some(1).map(closure_mac!()); // don't lint closure in macro expansion
+ let _: Option<Vec<u8>> = true.then(|| vec![]); // special case vec!
+ let d = Some(1u8).map(|a| foo((|b| foo2(b))(a))); //is adjusted?
+ all(&[1, 2, 3], &&2, |x, y| below(x, y)); //is adjusted
+ unsafe {
+ Some(1u8).map(|a| unsafe_fn(a)); // unsafe fn
+ }
+
+ // See #815
+ let e = Some(1u8).map(|a| divergent(a));
+ let e = Some(1u8).map(|a| generic(a));
+ let e = Some(1u8).map(generic);
+ // See #515
+ let a: Option<Box<dyn (::std::ops::Deref<Target = [i32]>)>> =
+ Some(vec![1i32, 2]).map(|v| -> Box<dyn (::std::ops::Deref<Target = [i32]>)> { Box::new(v) });
+
+ // issue #7224
+ let _: Option<Vec<u32>> = Some(0).map(|_| vec![]);
+}
+
+trait TestTrait {
+ fn trait_foo(self) -> bool;
+ fn trait_foo_ref(&self) -> bool;
+}
+
+struct TestStruct<'a> {
+ some_ref: &'a i32,
+}
+
+impl<'a> TestStruct<'a> {
+ fn foo(self) -> bool {
+ false
+ }
+ unsafe fn foo_unsafe(self) -> bool {
+ true
+ }
+}
+
+impl<'a> TestTrait for TestStruct<'a> {
+ fn trait_foo(self) -> bool {
+ false
+ }
+ fn trait_foo_ref(&self) -> bool {
+ false
+ }
+}
+
+impl<'a> std::ops::Deref for TestStruct<'a> {
+ type Target = char;
+ fn deref(&self) -> &char {
+ &'a'
+ }
+}
+
+fn test_redundant_closures_containing_method_calls() {
+ let i = 10;
+ let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo());
+ let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo());
+ let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo_ref());
+ let e = Some(&mut vec![1, 2, 3]).map(|v| v.clear());
+ unsafe {
+ let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo_unsafe());
+ }
+ let e = Some("str").map(|s| s.to_string());
+ let e = Some('a').map(|s| s.to_uppercase());
+ let e: std::vec::Vec<usize> = vec!['a', 'b', 'c'].iter().map(|c| c.len_utf8()).collect();
+ let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(|c| c.to_ascii_uppercase()).collect();
+ let e = Some(PathBuf::new()).as_ref().and_then(|s| s.to_str());
+ let c = Some(TestStruct { some_ref: &i })
+ .as_ref()
+ .map(|c| c.to_ascii_uppercase());
+
+ fn test_different_borrow_levels<T>(t: &[&T])
+ where
+ T: TestTrait,
+ {
+ t.iter().filter(|x| x.trait_foo_ref());
+ t.iter().map(|x| x.trait_foo_ref());
+ }
+}
+
+struct Thunk<T>(Box<dyn FnMut() -> T>);
+
+impl<T> Thunk<T> {
+ fn new<F: 'static + FnOnce() -> T>(f: F) -> Thunk<T> {
+ let mut option = Some(f);
+ // This should not trigger redundant_closure (#1439)
+ Thunk(Box::new(move || option.take().unwrap()()))
+ }
+
+ fn unwrap(self) -> T {
+ let Thunk(mut f) = self;
+ f()
+ }
+}
+
+fn foobar() {
+ let thunk = Thunk::new(|| println!("Hello, world!"));
+ thunk.unwrap()
+}
+
+fn foo(_: u8) {}
+
+fn foo2(_: u8) -> u8 {
+ 1u8
+}
+
+fn all<X, F>(x: &[X], y: &X, f: F) -> bool
+where
+ F: Fn(&X, &X) -> bool,
+{
+ x.iter().all(|e| f(e, y))
+}
+
+fn below(x: &u8, y: &u8) -> bool {
+ x < y
+}
+
+unsafe fn unsafe_fn(_: u8) {}
+
+fn divergent(_: u8) -> ! {
+ unimplemented!()
+}
+
+fn generic<T>(_: T) -> u8 {
+ 0
+}
+
+fn passes_fn_mut(mut x: Box<dyn FnMut()>) {
+ requires_fn_once(|| x());
+}
+fn requires_fn_once<T: FnOnce()>(_: T) {}
+
+fn test_redundant_closure_with_function_pointer() {
+ type FnPtrType = fn(u8);
+ let foo_ptr: FnPtrType = foo;
+ let a = Some(1u8).map(|a| foo_ptr(a));
+}
+
+fn test_redundant_closure_with_another_closure() {
+ let closure = |a| println!("{}", a);
+ let a = Some(1u8).map(|a| closure(a));
+}
+
+fn make_lazy(f: impl Fn() -> fn(u8) -> u8) -> impl Fn(u8) -> u8 {
+ // Currently f is called when result of make_lazy is called.
+ // If the closure is removed, f will be called when make_lazy itself is
+ // called. This changes semantics, so the closure must stay.
+ Box::new(move |x| f()(x))
+}
+
+fn call<F: FnOnce(&mut String) -> String>(f: F) -> String {
+ f(&mut "Hello".to_owned())
+}
+fn test_difference_in_mutability() {
+ call(|s| s.clone());
+}
+
+struct Bar;
+impl std::ops::Deref for Bar {
+ type Target = str;
+ fn deref(&self) -> &str {
+ "hi"
+ }
+}
+
+fn test_deref_with_trait_method() {
+ let _ = [Bar].iter().map(|s| s.to_string()).collect::<Vec<_>>();
+}
+
+fn mutable_closure_used_again(x: Vec<i32>, y: Vec<i32>, z: Vec<i32>) {
+ let mut res = Vec::new();
+ let mut add_to_res = |n| res.push(n);
+ x.into_iter().for_each(|x| add_to_res(x));
+ y.into_iter().for_each(|x| add_to_res(x));
+ z.into_iter().for_each(|x| add_to_res(x));
+}
+
+fn mutable_closure_in_loop() {
+ let mut value = 0;
+ let mut closure = |n| value += n;
+ for _ in 0..5 {
+ Some(1).map(|n| closure(n));
+
+ let mut value = 0;
+ let mut in_loop = |n| value += n;
+ Some(1).map(|n| in_loop(n));
+ }
+}
+
+fn late_bound_lifetimes() {
+ fn take_asref_path<P: AsRef<Path>>(path: P) {}
+
+ fn map_str<F>(thunk: F)
+ where
+ F: FnOnce(&str),
+ {
+ }
+
+ fn map_str_to_path<F>(thunk: F)
+ where
+ F: FnOnce(&str) -> &Path,
+ {
+ }
+ map_str(|s| take_asref_path(s));
+ map_str_to_path(|s| s.as_ref());
+}
+
+mod type_param_bound {
+ trait Trait {
+ fn fun();
+ }
+
+ fn take<T: 'static>(_: T) {}
+
+ fn test<X: Trait>() {
+ // don't lint, but it's questionable that rust requires a cast
+ take(|| X::fun());
+ take(X::fun as fn());
+ }
+}
+
+// #8073 Don't replace closure with `Arc<F>` or `Rc<F>`
+fn arc_fp() {
+ let rc = std::rc::Rc::new(|| 7);
+ let arc = std::sync::Arc::new(|n| n + 1);
+ let ref_arc = &std::sync::Arc::new(|_| 5);
+
+ true.then(|| rc());
+ (0..5).map(|n| arc(n));
+ Some(4).map(|n| ref_arc(n));
+}
+
+// #8460 Don't replace closures with params bounded as `ref`
+mod bind_by_ref {
+ struct A;
+ struct B;
+
+ impl From<&A> for B {
+ fn from(A: &A) -> Self {
+ B
+ }
+ }
+
+ fn test() {
+ // should not lint
+ Some(A).map(|a| B::from(&a));
+ // should not lint
+ Some(A).map(|ref a| B::from(a));
+ }
+}
+
+// #7812 False positive on coerced closure
+fn coerced_closure() {
+ fn function_returning_unit<F: FnMut(i32)>(f: F) {}
+ function_returning_unit(|x| std::process::exit(x));
+
+ fn arr() -> &'static [u8; 0] {
+ &[]
+ }
+ fn slice_fn(_: impl FnOnce() -> &'static [u8]) {}
+ slice_fn(|| arr());
+}
++
++// https://github.com/rust-lang/rust-clippy/issues/7861
++fn box_dyn() {
++ fn f(_: impl Fn(usize) -> Box<dyn std::any::Any>) {}
++ f(|x| Box::new(x));
++}
++
++// https://github.com/rust-lang/rust-clippy/issues/5939
++fn not_general_enough() {
++ fn f(_: impl FnMut(&Path) -> std::io::Result<()>) {}
++ f(|path| std::fs::remove_file(path));
++}
--- /dev/null
- let result = option.ok_or("x not found");
+#![warn(clippy::for_loops_over_fallibles)]
+
+fn for_loops_over_fallibles() {
+ let option = Some(1);
++ let mut result = option.ok_or("x not found");
+ let v = vec![0, 1, 2];
+
+ // check over an `Option`
+ for x in option {
+ println!("{}", x);
+ }
+
++ // check over an `Option`
++ for x in option.iter() {
++ println!("{}", x);
++ }
++
+ // check over a `Result`
+ for x in result {
+ println!("{}", x);
+ }
+
++ // check over a `Result`
++ for x in result.iter_mut() {
++ println!("{}", x);
++ }
++
++ // check over a `Result`
++ for x in result.into_iter() {
++ println!("{}", x);
++ }
++
+ for x in option.ok_or("x not found") {
+ println!("{}", x);
+ }
+
+ // make sure LOOP_OVER_NEXT lint takes clippy::precedence when next() is the last call
+ // in the chain
+ for x in v.iter().next() {
+ println!("{}", x);
+ }
+
+ // make sure we lint when next() is not the last call in the chain
+ for x in v.iter().next().and(Some(0)) {
+ println!("{}", x);
+ }
+
+ for x in v.iter().next().ok_or("x not found") {
+ println!("{}", x);
+ }
+
+ // check for false positives
+
+ // for loop false positive
+ for x in v {
+ println!("{}", x);
+ }
+
+ // while let false positive for Option
+ while let Some(x) = option {
+ println!("{}", x);
+ break;
+ }
+
+ // while let false positive for Result
+ while let Ok(x) = result {
+ println!("{}", x);
+ break;
+ }
+}
+
+fn main() {}
--- /dev/null
- error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement
+error: for loop over `option`, which is an `Option`. This is more readably written as an `if let` statement
+ --> $DIR/for_loops_over_fallibles.rs:9:14
+ |
+LL | for x in option {
+ | ^^^^^^
+ |
+ = note: `-D clippy::for-loops-over-fallibles` implied by `-D warnings`
+ = help: consider replacing `for x in option` with `if let Some(x) = option`
+
- --> $DIR/for_loops_over_fallibles.rs:18:14
++error: for loop over `option`, which is an `Option`. This is more readably written as an `if let` statement
+ --> $DIR/for_loops_over_fallibles.rs:14:14
+ |
++LL | for x in option.iter() {
++ | ^^^^^^
++ |
++ = help: consider replacing `for x in option.iter()` with `if let Some(x) = option`
++
++error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement
++ --> $DIR/for_loops_over_fallibles.rs:19:14
++ |
+LL | for x in result {
+ | ^^^^^^
+ |
+ = help: consider replacing `for x in result` with `if let Ok(x) = result`
+
++error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement
++ --> $DIR/for_loops_over_fallibles.rs:24:14
++ |
++LL | for x in result.iter_mut() {
++ | ^^^^^^
++ |
++ = help: consider replacing `for x in result.iter_mut()` with `if let Ok(x) = result`
++
++error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement
++ --> $DIR/for_loops_over_fallibles.rs:29:14
++ |
++LL | for x in result.into_iter() {
++ | ^^^^^^
++ |
++ = help: consider replacing `for x in result.into_iter()` with `if let Ok(x) = result`
++
+error: for loop over `option.ok_or("x not found")`, which is a `Result`. This is more readably written as an `if let` statement
- --> $DIR/for_loops_over_fallibles.rs:24:14
++ --> $DIR/for_loops_over_fallibles.rs:33:14
+ |
+LL | for x in option.ok_or("x not found") {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = help: consider replacing `for x in option.ok_or("x not found")` with `if let Ok(x) = option.ok_or("x not found")`
+
+error: you are iterating over `Iterator::next()` which is an Option; this will compile but is probably not what you want
- --> $DIR/for_loops_over_fallibles.rs:29:14
++ --> $DIR/for_loops_over_fallibles.rs:39:14
+ |
+LL | for x in v.iter().next() {
+ | ^^^^^^^^^^^^^^^
+ |
+ = note: `#[deny(clippy::iter_next_loop)]` on by default
+
+error: for loop over `v.iter().next().and(Some(0))`, which is an `Option`. This is more readably written as an `if let` statement
- --> $DIR/for_loops_over_fallibles.rs:33:14
++ --> $DIR/for_loops_over_fallibles.rs:44:14
+ |
+LL | for x in v.iter().next().and(Some(0)) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = help: consider replacing `for x in v.iter().next().and(Some(0))` with `if let Some(x) = v.iter().next().and(Some(0))`
+
+error: for loop over `v.iter().next().ok_or("x not found")`, which is a `Result`. This is more readably written as an `if let` statement
- --> $DIR/for_loops_over_fallibles.rs:45:5
++ --> $DIR/for_loops_over_fallibles.rs:48:14
+ |
+LL | for x in v.iter().next().ok_or("x not found") {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = help: consider replacing `for x in v.iter().next().ok_or("x not found")` with `if let Ok(x) = v.iter().next().ok_or("x not found")`
+
+error: this loop never actually loops
- --> $DIR/for_loops_over_fallibles.rs:51:5
++ --> $DIR/for_loops_over_fallibles.rs:60:5
+ |
+LL | / while let Some(x) = option {
+LL | | println!("{}", x);
+LL | | break;
+LL | | }
+ | |_____^
+ |
+ = note: `#[deny(clippy::never_loop)]` on by default
+
+error: this loop never actually loops
- error: aborting due to 8 previous errors
++ --> $DIR/for_loops_over_fallibles.rs:66:5
+ |
+LL | / while let Ok(x) = result {
+LL | | println!("{}", x);
+LL | | break;
+LL | | }
+ | |_____^
+
++error: aborting due to 11 previous errors
+
--- /dev/null
- .iter().flatten().cloned();
+// run-rustfix
+#![warn(clippy::iter_overeager_cloned, clippy::redundant_clone, clippy::filter_next)]
+#![allow(dead_code, clippy::let_unit_value)]
+
+fn main() {
+ let vec = vec!["1".to_string(), "2".to_string(), "3".to_string()];
+
+ let _: Option<String> = vec.iter().last().cloned();
+
+ let _: Option<String> = vec.iter().chain(vec.iter()).next().cloned();
+
+ let _: usize = vec.iter().filter(|x| x == &"2").count();
+
+ let _: Vec<_> = vec.iter().take(2).cloned().collect();
+
+ let _: Vec<_> = vec.iter().skip(2).cloned().collect();
+
+ let _ = vec.iter().filter(|x| x == &"2").nth(2).cloned();
+
+ let _ = [Some(Some("str".to_string())), Some(Some("str".to_string()))]
++ .iter()
++ .flatten().cloned();
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().filter(|x| x.starts_with('2'));
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().map(|x| x.len());
+
+ // This would fail if changed.
+ let _ = vec.iter().cloned().map(|x| x + "2");
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().find(|x| x == "2");
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().for_each(|x| assert!(!x.is_empty()));
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().all(|x| x.len() == 1);
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().any(|x| x.len() == 1);
+
+ // Should probably stay as it is.
+ let _ = [0, 1, 2, 3, 4].iter().cloned().take(10);
++
++ // `&Range<_>` doesn't implement `IntoIterator`
++ let _ = [0..1, 2..5].iter().cloned().flatten();
+}
+
+// #8527
+fn cloned_flatten(x: Option<&Option<String>>) -> Option<String> {
+ x.cloned().flatten()
+}
--- /dev/null
+// run-rustfix
+#![warn(clippy::iter_overeager_cloned, clippy::redundant_clone, clippy::filter_next)]
+#![allow(dead_code, clippy::let_unit_value)]
+
+fn main() {
+ let vec = vec!["1".to_string(), "2".to_string(), "3".to_string()];
+
+ let _: Option<String> = vec.iter().cloned().last();
+
+ let _: Option<String> = vec.iter().chain(vec.iter()).cloned().next();
+
+ let _: usize = vec.iter().filter(|x| x == &"2").cloned().count();
+
+ let _: Vec<_> = vec.iter().cloned().take(2).collect();
+
+ let _: Vec<_> = vec.iter().cloned().skip(2).collect();
+
+ let _ = vec.iter().filter(|x| x == &"2").cloned().nth(2);
+
+ let _ = [Some(Some("str".to_string())), Some(Some("str".to_string()))]
+ .iter()
+ .cloned()
+ .flatten();
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().filter(|x| x.starts_with('2'));
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().map(|x| x.len());
+
+ // This would fail if changed.
+ let _ = vec.iter().cloned().map(|x| x + "2");
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().find(|x| x == "2");
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().for_each(|x| assert!(!x.is_empty()));
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().all(|x| x.len() == 1);
+
+ // Not implemented yet
+ let _ = vec.iter().cloned().any(|x| x.len() == 1);
+
+ // Should probably stay as it is.
+ let _ = [0, 1, 2, 3, 4].iter().cloned().take(10);
++
++ // `&Range<_>` doesn't implement `IntoIterator`
++ let _ = [0..1, 2..5].iter().cloned().flatten();
+}
+
+// #8527
+fn cloned_flatten(x: Option<&Option<String>>) -> Option<String> {
+ x.cloned().flatten()
+}
--- /dev/null
- error: called `cloned().last()` on an `Iterator`. It may be more efficient to call `last().cloned()` instead
++error: unnecessarily eager cloning of iterator items
+ --> $DIR/iter_overeager_cloned.rs:8:29
+ |
+LL | let _: Option<String> = vec.iter().cloned().last();
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().last().cloned()`
++ | ^^^^^^^^^^----------------
++ | |
++ | help: try this: `.last().cloned()`
+ |
+ = note: `-D clippy::iter-overeager-cloned` implied by `-D warnings`
+
- error: called `cloned().next()` on an `Iterator`. It may be more efficient to call `next().cloned()` instead
++error: unnecessarily eager cloning of iterator items
+ --> $DIR/iter_overeager_cloned.rs:10:29
+ |
+LL | let _: Option<String> = vec.iter().chain(vec.iter()).cloned().next();
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().chain(vec.iter()).next().cloned()`
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^----------------
++ | |
++ | help: try this: `.next().cloned()`
+
- error: called `cloned().count()` on an `Iterator`. It may be more efficient to call `count()` instead
++error: unneeded cloning of iterator items
+ --> $DIR/iter_overeager_cloned.rs:12:20
+ |
+LL | let _: usize = vec.iter().filter(|x| x == &"2").cloned().count();
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().filter(|x| x == &"2").count()`
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-----------------
++ | |
++ | help: try this: `.count()`
+ |
+ = note: `-D clippy::redundant-clone` implied by `-D warnings`
+
- error: called `cloned().take(...)` on an `Iterator`. It may be more efficient to call `take(...).cloned()` instead
++error: unnecessarily eager cloning of iterator items
+ --> $DIR/iter_overeager_cloned.rs:14:21
+ |
+LL | let _: Vec<_> = vec.iter().cloned().take(2).collect();
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().take(2).cloned()`
++ | ^^^^^^^^^^-----------------
++ | |
++ | help: try this: `.take(2).cloned()`
+
- error: called `cloned().skip(...)` on an `Iterator`. It may be more efficient to call `skip(...).cloned()` instead
++error: unnecessarily eager cloning of iterator items
+ --> $DIR/iter_overeager_cloned.rs:16:21
+ |
+LL | let _: Vec<_> = vec.iter().cloned().skip(2).collect();
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().skip(2).cloned()`
++ | ^^^^^^^^^^-----------------
++ | |
++ | help: try this: `.skip(2).cloned()`
+
- error: called `cloned().nth(...)` on an `Iterator`. It may be more efficient to call `nth(...).cloned()` instead
++error: unnecessarily eager cloning of iterator items
+ --> $DIR/iter_overeager_cloned.rs:18:13
+ |
+LL | let _ = vec.iter().filter(|x| x == &"2").cloned().nth(2);
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec.iter().filter(|x| x == &"2").nth(2).cloned()`
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^----------------
++ | |
++ | help: try this: `.nth(2).cloned()`
+
- error: called `cloned().flatten()` on an `Iterator`. It may be more efficient to call `flatten().cloned()` instead
++error: unnecessarily eager cloning of iterator items
+ --> $DIR/iter_overeager_cloned.rs:20:13
+ |
+LL | let _ = [Some(Some("str".to_string())), Some(Some("str".to_string()))]
+ | _____________^
+LL | | .iter()
+LL | | .cloned()
+LL | | .flatten();
+ | |__________________^
+ |
+help: try this
+ |
- LL ~ let _ = [Some(Some("str".to_string())), Some(Some("str".to_string()))]
- LL ~ .iter().flatten().cloned();
++LL ~ .iter()
++LL ~ .flatten().cloned();
+ |
+
+error: aborting due to 7 previous errors
+
--- /dev/null
+// run-rustfix
+#![allow(dead_code)]
+#![warn(clippy::manual_filter_map)]
+#![allow(clippy::redundant_closure)] // FIXME suggestion may have redundant closure
+
+fn main() {
+ // is_some(), unwrap()
+ let _ = (0..).filter_map(|a| to_opt(a));
+
+ // ref pattern, expect()
+ let _ = (0..).filter_map(|a| to_opt(a));
+
+ // is_ok(), unwrap_or()
+ let _ = (0..).filter_map(|a| to_res(a).ok());
+}
+
+fn no_lint() {
+ // no shared code
+ let _ = (0..).filter(|n| *n > 1).map(|n| n + 1);
+
+ // very close but different since filter() provides a reference
+ let _ = (0..).filter(|n| to_opt(n).is_some()).map(|a| to_opt(a).unwrap());
+
+ // similar but different
+ let _ = (0..).filter(|n| to_opt(n).is_some()).map(|n| to_res(n).unwrap());
+ let _ = (0..)
+ .filter(|n| to_opt(n).map(|n| n + 1).is_some())
+ .map(|a| to_opt(a).unwrap());
+}
+
+fn to_opt<T>(_: T) -> Option<T> {
+ unimplemented!()
+}
+
+fn to_res<T>(_: T) -> Result<T, ()> {
+ unimplemented!()
+}
++
++struct Issue8920<'a> {
++ option_field: Option<String>,
++ result_field: Result<String, ()>,
++ ref_field: Option<&'a usize>,
++}
++
++fn issue_8920() {
++ let mut vec = vec![Issue8920 {
++ option_field: Some(String::from("str")),
++ result_field: Ok(String::from("str")),
++ ref_field: Some(&1),
++ }];
++
++ let _ = vec
++ .iter()
++ .filter_map(|f| f.option_field.clone());
++
++ let _ = vec
++ .iter()
++ .filter_map(|f| f.ref_field.cloned());
++
++ let _ = vec
++ .iter()
++ .filter_map(|f| f.ref_field.copied());
++
++ let _ = vec
++ .iter()
++ .filter_map(|f| f.result_field.clone().ok());
++
++ let _ = vec
++ .iter()
++ .filter_map(|f| f.result_field.as_ref().ok());
++
++ let _ = vec
++ .iter()
++ .filter_map(|f| f.result_field.as_deref().ok());
++
++ let _ = vec
++ .iter_mut()
++ .filter_map(|f| f.result_field.as_mut().ok());
++
++ let _ = vec
++ .iter_mut()
++ .filter_map(|f| f.result_field.as_deref_mut().ok());
++
++ let _ = vec
++ .iter()
++ .filter_map(|f| f.result_field.to_owned().ok());
++}
--- /dev/null
+// run-rustfix
+#![allow(dead_code)]
+#![warn(clippy::manual_filter_map)]
+#![allow(clippy::redundant_closure)] // FIXME suggestion may have redundant closure
+
+fn main() {
+ // is_some(), unwrap()
+ let _ = (0..).filter(|n| to_opt(*n).is_some()).map(|a| to_opt(a).unwrap());
+
+ // ref pattern, expect()
+ let _ = (0..).filter(|&n| to_opt(n).is_some()).map(|a| to_opt(a).expect("hi"));
+
+ // is_ok(), unwrap_or()
+ let _ = (0..).filter(|&n| to_res(n).is_ok()).map(|a| to_res(a).unwrap_or(1));
+}
+
+fn no_lint() {
+ // no shared code
+ let _ = (0..).filter(|n| *n > 1).map(|n| n + 1);
+
+ // very close but different since filter() provides a reference
+ let _ = (0..).filter(|n| to_opt(n).is_some()).map(|a| to_opt(a).unwrap());
+
+ // similar but different
+ let _ = (0..).filter(|n| to_opt(n).is_some()).map(|n| to_res(n).unwrap());
+ let _ = (0..)
+ .filter(|n| to_opt(n).map(|n| n + 1).is_some())
+ .map(|a| to_opt(a).unwrap());
+}
+
+fn to_opt<T>(_: T) -> Option<T> {
+ unimplemented!()
+}
+
+fn to_res<T>(_: T) -> Result<T, ()> {
+ unimplemented!()
+}
++
++struct Issue8920<'a> {
++ option_field: Option<String>,
++ result_field: Result<String, ()>,
++ ref_field: Option<&'a usize>,
++}
++
++fn issue_8920() {
++ let mut vec = vec![Issue8920 {
++ option_field: Some(String::from("str")),
++ result_field: Ok(String::from("str")),
++ ref_field: Some(&1),
++ }];
++
++ let _ = vec
++ .iter()
++ .filter(|f| f.option_field.is_some())
++ .map(|f| f.option_field.clone().unwrap());
++
++ let _ = vec
++ .iter()
++ .filter(|f| f.ref_field.is_some())
++ .map(|f| f.ref_field.cloned().unwrap());
++
++ let _ = vec
++ .iter()
++ .filter(|f| f.ref_field.is_some())
++ .map(|f| f.ref_field.copied().unwrap());
++
++ let _ = vec
++ .iter()
++ .filter(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.clone().unwrap());
++
++ let _ = vec
++ .iter()
++ .filter(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.as_ref().unwrap());
++
++ let _ = vec
++ .iter()
++ .filter(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.as_deref().unwrap());
++
++ let _ = vec
++ .iter_mut()
++ .filter(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.as_mut().unwrap());
++
++ let _ = vec
++ .iter_mut()
++ .filter(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.as_deref_mut().unwrap());
++
++ let _ = vec
++ .iter()
++ .filter(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.to_owned().unwrap());
++}
--- /dev/null
- error: aborting due to 3 previous errors
+error: `filter(..).map(..)` can be simplified as `filter_map(..)`
+ --> $DIR/manual_filter_map.rs:8:19
+ |
+LL | let _ = (0..).filter(|n| to_opt(*n).is_some()).map(|a| to_opt(a).unwrap());
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `filter_map(|a| to_opt(a))`
+ |
+ = note: `-D clippy::manual-filter-map` implied by `-D warnings`
+
+error: `filter(..).map(..)` can be simplified as `filter_map(..)`
+ --> $DIR/manual_filter_map.rs:11:19
+ |
+LL | let _ = (0..).filter(|&n| to_opt(n).is_some()).map(|a| to_opt(a).expect("hi"));
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `filter_map(|a| to_opt(a))`
+
+error: `filter(..).map(..)` can be simplified as `filter_map(..)`
+ --> $DIR/manual_filter_map.rs:14:19
+ |
+LL | let _ = (0..).filter(|&n| to_res(n).is_ok()).map(|a| to_res(a).unwrap_or(1));
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `filter_map(|a| to_res(a).ok())`
+
++error: `filter(..).map(..)` can be simplified as `filter_map(..)`
++ --> $DIR/manual_filter_map.rs:54:10
++ |
++LL | .filter(|f| f.option_field.is_some())
++ | __________^
++LL | | .map(|f| f.option_field.clone().unwrap());
++ | |_________________________________________________^ help: try: `filter_map(|f| f.option_field.clone())`
++
++error: `filter(..).map(..)` can be simplified as `filter_map(..)`
++ --> $DIR/manual_filter_map.rs:59:10
++ |
++LL | .filter(|f| f.ref_field.is_some())
++ | __________^
++LL | | .map(|f| f.ref_field.cloned().unwrap());
++ | |_______________________________________________^ help: try: `filter_map(|f| f.ref_field.cloned())`
++
++error: `filter(..).map(..)` can be simplified as `filter_map(..)`
++ --> $DIR/manual_filter_map.rs:64:10
++ |
++LL | .filter(|f| f.ref_field.is_some())
++ | __________^
++LL | | .map(|f| f.ref_field.copied().unwrap());
++ | |_______________________________________________^ help: try: `filter_map(|f| f.ref_field.copied())`
++
++error: `filter(..).map(..)` can be simplified as `filter_map(..)`
++ --> $DIR/manual_filter_map.rs:69:10
++ |
++LL | .filter(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.clone().unwrap());
++ | |_________________________________________________^ help: try: `filter_map(|f| f.result_field.clone().ok())`
++
++error: `filter(..).map(..)` can be simplified as `filter_map(..)`
++ --> $DIR/manual_filter_map.rs:74:10
++ |
++LL | .filter(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.as_ref().unwrap());
++ | |__________________________________________________^ help: try: `filter_map(|f| f.result_field.as_ref().ok())`
++
++error: `filter(..).map(..)` can be simplified as `filter_map(..)`
++ --> $DIR/manual_filter_map.rs:79:10
++ |
++LL | .filter(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.as_deref().unwrap());
++ | |____________________________________________________^ help: try: `filter_map(|f| f.result_field.as_deref().ok())`
++
++error: `filter(..).map(..)` can be simplified as `filter_map(..)`
++ --> $DIR/manual_filter_map.rs:84:10
++ |
++LL | .filter(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.as_mut().unwrap());
++ | |__________________________________________________^ help: try: `filter_map(|f| f.result_field.as_mut().ok())`
++
++error: `filter(..).map(..)` can be simplified as `filter_map(..)`
++ --> $DIR/manual_filter_map.rs:89:10
++ |
++LL | .filter(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.as_deref_mut().unwrap());
++ | |________________________________________________________^ help: try: `filter_map(|f| f.result_field.as_deref_mut().ok())`
++
++error: `filter(..).map(..)` can be simplified as `filter_map(..)`
++ --> $DIR/manual_filter_map.rs:94:10
++ |
++LL | .filter(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.to_owned().unwrap());
++ | |____________________________________________________^ help: try: `filter_map(|f| f.result_field.to_owned().ok())`
++
++error: aborting due to 12 previous errors
+
--- /dev/null
+// run-rustfix
+#![allow(dead_code)]
+#![warn(clippy::manual_find_map)]
+#![allow(clippy::redundant_closure)] // FIXME suggestion may have redundant closure
+
+fn main() {
+ // is_some(), unwrap()
+ let _ = (0..).find_map(|a| to_opt(a));
+
+ // ref pattern, expect()
+ let _ = (0..).find_map(|a| to_opt(a));
+
+ // is_ok(), unwrap_or()
+ let _ = (0..).find_map(|a| to_res(a).ok());
+}
+
+fn no_lint() {
+ // no shared code
+ let _ = (0..).filter(|n| *n > 1).map(|n| n + 1);
+
+ // very close but different since filter() provides a reference
+ let _ = (0..).find(|n| to_opt(n).is_some()).map(|a| to_opt(a).unwrap());
+
+ // similar but different
+ let _ = (0..).find(|n| to_opt(n).is_some()).map(|n| to_res(n).unwrap());
+ let _ = (0..)
+ .find(|n| to_opt(n).map(|n| n + 1).is_some())
+ .map(|a| to_opt(a).unwrap());
+}
+
+fn to_opt<T>(_: T) -> Option<T> {
+ unimplemented!()
+}
+
+fn to_res<T>(_: T) -> Result<T, ()> {
+ unimplemented!()
+}
++
++struct Issue8920<'a> {
++ option_field: Option<String>,
++ result_field: Result<String, ()>,
++ ref_field: Option<&'a usize>,
++}
++
++fn issue_8920() {
++ let mut vec = vec![Issue8920 {
++ option_field: Some(String::from("str")),
++ result_field: Ok(String::from("str")),
++ ref_field: Some(&1),
++ }];
++
++ let _ = vec
++ .iter()
++ .find_map(|f| f.option_field.clone());
++
++ let _ = vec
++ .iter()
++ .find_map(|f| f.ref_field.cloned());
++
++ let _ = vec
++ .iter()
++ .find_map(|f| f.ref_field.copied());
++
++ let _ = vec
++ .iter()
++ .find_map(|f| f.result_field.clone().ok());
++
++ let _ = vec
++ .iter()
++ .find_map(|f| f.result_field.as_ref().ok());
++
++ let _ = vec
++ .iter()
++ .find_map(|f| f.result_field.as_deref().ok());
++
++ let _ = vec
++ .iter_mut()
++ .find_map(|f| f.result_field.as_mut().ok());
++
++ let _ = vec
++ .iter_mut()
++ .find_map(|f| f.result_field.as_deref_mut().ok());
++
++ let _ = vec
++ .iter()
++ .find_map(|f| f.result_field.to_owned().ok());
++}
--- /dev/null
+// run-rustfix
+#![allow(dead_code)]
+#![warn(clippy::manual_find_map)]
+#![allow(clippy::redundant_closure)] // FIXME suggestion may have redundant closure
+
+fn main() {
+ // is_some(), unwrap()
+ let _ = (0..).find(|n| to_opt(*n).is_some()).map(|a| to_opt(a).unwrap());
+
+ // ref pattern, expect()
+ let _ = (0..).find(|&n| to_opt(n).is_some()).map(|a| to_opt(a).expect("hi"));
+
+ // is_ok(), unwrap_or()
+ let _ = (0..).find(|&n| to_res(n).is_ok()).map(|a| to_res(a).unwrap_or(1));
+}
+
+fn no_lint() {
+ // no shared code
+ let _ = (0..).filter(|n| *n > 1).map(|n| n + 1);
+
+ // very close but different since filter() provides a reference
+ let _ = (0..).find(|n| to_opt(n).is_some()).map(|a| to_opt(a).unwrap());
+
+ // similar but different
+ let _ = (0..).find(|n| to_opt(n).is_some()).map(|n| to_res(n).unwrap());
+ let _ = (0..)
+ .find(|n| to_opt(n).map(|n| n + 1).is_some())
+ .map(|a| to_opt(a).unwrap());
+}
+
+fn to_opt<T>(_: T) -> Option<T> {
+ unimplemented!()
+}
+
+fn to_res<T>(_: T) -> Result<T, ()> {
+ unimplemented!()
+}
++
++struct Issue8920<'a> {
++ option_field: Option<String>,
++ result_field: Result<String, ()>,
++ ref_field: Option<&'a usize>,
++}
++
++fn issue_8920() {
++ let mut vec = vec![Issue8920 {
++ option_field: Some(String::from("str")),
++ result_field: Ok(String::from("str")),
++ ref_field: Some(&1),
++ }];
++
++ let _ = vec
++ .iter()
++ .find(|f| f.option_field.is_some())
++ .map(|f| f.option_field.clone().unwrap());
++
++ let _ = vec
++ .iter()
++ .find(|f| f.ref_field.is_some())
++ .map(|f| f.ref_field.cloned().unwrap());
++
++ let _ = vec
++ .iter()
++ .find(|f| f.ref_field.is_some())
++ .map(|f| f.ref_field.copied().unwrap());
++
++ let _ = vec
++ .iter()
++ .find(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.clone().unwrap());
++
++ let _ = vec
++ .iter()
++ .find(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.as_ref().unwrap());
++
++ let _ = vec
++ .iter()
++ .find(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.as_deref().unwrap());
++
++ let _ = vec
++ .iter_mut()
++ .find(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.as_mut().unwrap());
++
++ let _ = vec
++ .iter_mut()
++ .find(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.as_deref_mut().unwrap());
++
++ let _ = vec
++ .iter()
++ .find(|f| f.result_field.is_ok())
++ .map(|f| f.result_field.to_owned().unwrap());
++}
--- /dev/null
- error: aborting due to 3 previous errors
+error: `find(..).map(..)` can be simplified as `find_map(..)`
+ --> $DIR/manual_find_map.rs:8:19
+ |
+LL | let _ = (0..).find(|n| to_opt(*n).is_some()).map(|a| to_opt(a).unwrap());
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `find_map(|a| to_opt(a))`
+ |
+ = note: `-D clippy::manual-find-map` implied by `-D warnings`
+
+error: `find(..).map(..)` can be simplified as `find_map(..)`
+ --> $DIR/manual_find_map.rs:11:19
+ |
+LL | let _ = (0..).find(|&n| to_opt(n).is_some()).map(|a| to_opt(a).expect("hi"));
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `find_map(|a| to_opt(a))`
+
+error: `find(..).map(..)` can be simplified as `find_map(..)`
+ --> $DIR/manual_find_map.rs:14:19
+ |
+LL | let _ = (0..).find(|&n| to_res(n).is_ok()).map(|a| to_res(a).unwrap_or(1));
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `find_map(|a| to_res(a).ok())`
+
++error: `find(..).map(..)` can be simplified as `find_map(..)`
++ --> $DIR/manual_find_map.rs:54:10
++ |
++LL | .find(|f| f.option_field.is_some())
++ | __________^
++LL | | .map(|f| f.option_field.clone().unwrap());
++ | |_________________________________________________^ help: try: `find_map(|f| f.option_field.clone())`
++
++error: `find(..).map(..)` can be simplified as `find_map(..)`
++ --> $DIR/manual_find_map.rs:59:10
++ |
++LL | .find(|f| f.ref_field.is_some())
++ | __________^
++LL | | .map(|f| f.ref_field.cloned().unwrap());
++ | |_______________________________________________^ help: try: `find_map(|f| f.ref_field.cloned())`
++
++error: `find(..).map(..)` can be simplified as `find_map(..)`
++ --> $DIR/manual_find_map.rs:64:10
++ |
++LL | .find(|f| f.ref_field.is_some())
++ | __________^
++LL | | .map(|f| f.ref_field.copied().unwrap());
++ | |_______________________________________________^ help: try: `find_map(|f| f.ref_field.copied())`
++
++error: `find(..).map(..)` can be simplified as `find_map(..)`
++ --> $DIR/manual_find_map.rs:69:10
++ |
++LL | .find(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.clone().unwrap());
++ | |_________________________________________________^ help: try: `find_map(|f| f.result_field.clone().ok())`
++
++error: `find(..).map(..)` can be simplified as `find_map(..)`
++ --> $DIR/manual_find_map.rs:74:10
++ |
++LL | .find(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.as_ref().unwrap());
++ | |__________________________________________________^ help: try: `find_map(|f| f.result_field.as_ref().ok())`
++
++error: `find(..).map(..)` can be simplified as `find_map(..)`
++ --> $DIR/manual_find_map.rs:79:10
++ |
++LL | .find(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.as_deref().unwrap());
++ | |____________________________________________________^ help: try: `find_map(|f| f.result_field.as_deref().ok())`
++
++error: `find(..).map(..)` can be simplified as `find_map(..)`
++ --> $DIR/manual_find_map.rs:84:10
++ |
++LL | .find(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.as_mut().unwrap());
++ | |__________________________________________________^ help: try: `find_map(|f| f.result_field.as_mut().ok())`
++
++error: `find(..).map(..)` can be simplified as `find_map(..)`
++ --> $DIR/manual_find_map.rs:89:10
++ |
++LL | .find(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.as_deref_mut().unwrap());
++ | |________________________________________________________^ help: try: `find_map(|f| f.result_field.as_deref_mut().ok())`
++
++error: `find(..).map(..)` can be simplified as `find_map(..)`
++ --> $DIR/manual_find_map.rs:94:10
++ |
++LL | .find(|f| f.result_field.is_ok())
++ | __________^
++LL | | .map(|f| f.result_field.to_owned().unwrap());
++ | |____________________________________________________^ help: try: `find_map(|f| f.result_field.to_owned().ok())`
++
++error: aborting due to 12 previous errors
+
--- /dev/null
+// run-rustfix
+
+#![warn(clippy::manual_map)]
+#![allow(
+ clippy::no_effect,
+ clippy::map_identity,
+ clippy::unit_arg,
+ clippy::match_ref_pats,
+ clippy::redundant_pattern_matching,
++ clippy::for_loops_over_fallibles,
+ dead_code
+)]
+
+fn main() {
+ Some(0).map(|_| 2);
+
+ Some(0).map(|x| x + 1);
+
+ Some("").map(|x| x.is_empty());
+
+ Some(0).map(|x| !x);
+
+ #[rustfmt::skip]
+ Some(0).map(std::convert::identity);
+
+ Some(&String::new()).map(|x| str::len(x));
+
+ match Some(0) {
+ Some(x) if false => Some(x + 1),
+ _ => None,
+ };
+
+ Some([0, 1]).as_ref().map(|x| x[0]);
+
+ Some(0).map(|x| x * 2);
+
+ Some(String::new()).as_ref().map(|x| x.is_empty());
+
+ Some(String::new()).as_ref().map(|x| x.len());
+
+ Some(0).map(|x| x + x);
+
+ #[warn(clippy::option_map_unit_fn)]
+ match &mut Some(String::new()) {
+ Some(x) => Some(x.push_str("")),
+ None => None,
+ };
+
+ #[allow(clippy::option_map_unit_fn)]
+ {
+ Some(String::new()).as_mut().map(|x| x.push_str(""));
+ }
+
+ Some(String::new()).as_ref().map(|x| x.len());
+
+ Some(String::new()).as_ref().map(|x| x.is_empty());
+
+ Some((0, 1, 2)).map(|(x, y, z)| x + y + z);
+
+ Some([1, 2, 3]).map(|[first, ..]| first);
+
+ Some((String::new(), "test")).as_ref().map(|(x, y)| (y, x));
+
+ match Some((String::new(), 0)) {
+ Some((ref x, y)) => Some((y, x)),
+ None => None,
+ };
+
+ match Some(Some(0)) {
+ Some(Some(_)) | Some(None) => Some(0),
+ None => None,
+ };
+
+ match Some(Some((0, 1))) {
+ Some(Some((x, 1))) => Some(x),
+ _ => None,
+ };
+
+ // #6795
+ fn f1() -> Result<(), ()> {
+ let _ = match Some(Ok(())) {
+ Some(x) => Some(x?),
+ None => None,
+ };
+ Ok(())
+ }
+
+ for &x in Some(Some(true)).iter() {
+ let _ = match x {
+ Some(x) => Some(if x { continue } else { x }),
+ None => None,
+ };
+ }
+
+ // #6797
+ let x1 = (Some(String::new()), 0);
+ let x2 = x1.0;
+ match x2 {
+ Some(x) => Some((x, x1.1)),
+ None => None,
+ };
+
+ struct S1 {
+ x: Option<String>,
+ y: u32,
+ }
+ impl S1 {
+ fn f(self) -> Option<(String, u32)> {
+ match self.x {
+ Some(x) => Some((x, self.y)),
+ None => None,
+ }
+ }
+ }
+
+ // #6811
+ Some(0).map(|x| vec![x]);
+
+ option_env!("").map(String::from);
+
+ // #6819
+ async fn f2(x: u32) -> u32 {
+ x
+ }
+
+ async fn f3() {
+ match Some(0) {
+ Some(x) => Some(f2(x).await),
+ None => None,
+ };
+ }
+
+ // #6847
+ if let Some(_) = Some(0) {
+ Some(0)
+ } else { Some(0).map(|x| x + 1) };
+
+ if true {
+ Some(0)
+ } else { Some(0).map(|x| x + 1) };
+
+ // #6967
+ const fn f4() {
+ match Some(0) {
+ Some(x) => Some(x + 1),
+ None => None,
+ };
+ }
+
+ // #7077
+ let s = &String::new();
+ #[allow(clippy::needless_match)]
+ let _: Option<&str> = match Some(s) {
+ Some(s) => Some(s),
+ None => None,
+ };
+}
--- /dev/null
+// run-rustfix
+
+#![warn(clippy::manual_map)]
+#![allow(
+ clippy::no_effect,
+ clippy::map_identity,
+ clippy::unit_arg,
+ clippy::match_ref_pats,
+ clippy::redundant_pattern_matching,
++ clippy::for_loops_over_fallibles,
+ dead_code
+)]
+
+fn main() {
+ match Some(0) {
+ Some(_) => Some(2),
+ None::<u32> => None,
+ };
+
+ match Some(0) {
+ Some(x) => Some(x + 1),
+ _ => None,
+ };
+
+ match Some("") {
+ Some(x) => Some(x.is_empty()),
+ None => None,
+ };
+
+ if let Some(x) = Some(0) {
+ Some(!x)
+ } else {
+ None
+ };
+
+ #[rustfmt::skip]
+ match Some(0) {
+ Some(x) => { Some(std::convert::identity(x)) }
+ None => { None }
+ };
+
+ match Some(&String::new()) {
+ Some(x) => Some(str::len(x)),
+ None => None,
+ };
+
+ match Some(0) {
+ Some(x) if false => Some(x + 1),
+ _ => None,
+ };
+
+ match &Some([0, 1]) {
+ Some(x) => Some(x[0]),
+ &None => None,
+ };
+
+ match &Some(0) {
+ &Some(x) => Some(x * 2),
+ None => None,
+ };
+
+ match Some(String::new()) {
+ Some(ref x) => Some(x.is_empty()),
+ _ => None,
+ };
+
+ match &&Some(String::new()) {
+ Some(x) => Some(x.len()),
+ _ => None,
+ };
+
+ match &&Some(0) {
+ &&Some(x) => Some(x + x),
+ &&_ => None,
+ };
+
+ #[warn(clippy::option_map_unit_fn)]
+ match &mut Some(String::new()) {
+ Some(x) => Some(x.push_str("")),
+ None => None,
+ };
+
+ #[allow(clippy::option_map_unit_fn)]
+ {
+ match &mut Some(String::new()) {
+ Some(x) => Some(x.push_str("")),
+ None => None,
+ };
+ }
+
+ match &mut Some(String::new()) {
+ Some(ref x) => Some(x.len()),
+ None => None,
+ };
+
+ match &mut &Some(String::new()) {
+ Some(x) => Some(x.is_empty()),
+ &mut _ => None,
+ };
+
+ match Some((0, 1, 2)) {
+ Some((x, y, z)) => Some(x + y + z),
+ None => None,
+ };
+
+ match Some([1, 2, 3]) {
+ Some([first, ..]) => Some(first),
+ None => None,
+ };
+
+ match &Some((String::new(), "test")) {
+ Some((x, y)) => Some((y, x)),
+ None => None,
+ };
+
+ match Some((String::new(), 0)) {
+ Some((ref x, y)) => Some((y, x)),
+ None => None,
+ };
+
+ match Some(Some(0)) {
+ Some(Some(_)) | Some(None) => Some(0),
+ None => None,
+ };
+
+ match Some(Some((0, 1))) {
+ Some(Some((x, 1))) => Some(x),
+ _ => None,
+ };
+
+ // #6795
+ fn f1() -> Result<(), ()> {
+ let _ = match Some(Ok(())) {
+ Some(x) => Some(x?),
+ None => None,
+ };
+ Ok(())
+ }
+
+ for &x in Some(Some(true)).iter() {
+ let _ = match x {
+ Some(x) => Some(if x { continue } else { x }),
+ None => None,
+ };
+ }
+
+ // #6797
+ let x1 = (Some(String::new()), 0);
+ let x2 = x1.0;
+ match x2 {
+ Some(x) => Some((x, x1.1)),
+ None => None,
+ };
+
+ struct S1 {
+ x: Option<String>,
+ y: u32,
+ }
+ impl S1 {
+ fn f(self) -> Option<(String, u32)> {
+ match self.x {
+ Some(x) => Some((x, self.y)),
+ None => None,
+ }
+ }
+ }
+
+ // #6811
+ match Some(0) {
+ Some(x) => Some(vec![x]),
+ None => None,
+ };
+
+ match option_env!("") {
+ Some(x) => Some(String::from(x)),
+ None => None,
+ };
+
+ // #6819
+ async fn f2(x: u32) -> u32 {
+ x
+ }
+
+ async fn f3() {
+ match Some(0) {
+ Some(x) => Some(f2(x).await),
+ None => None,
+ };
+ }
+
+ // #6847
+ if let Some(_) = Some(0) {
+ Some(0)
+ } else if let Some(x) = Some(0) {
+ Some(x + 1)
+ } else {
+ None
+ };
+
+ if true {
+ Some(0)
+ } else if let Some(x) = Some(0) {
+ Some(x + 1)
+ } else {
+ None
+ };
+
+ // #6967
+ const fn f4() {
+ match Some(0) {
+ Some(x) => Some(x + 1),
+ None => None,
+ };
+ }
+
+ // #7077
+ let s = &String::new();
+ #[allow(clippy::needless_match)]
+ let _: Option<&str> = match Some(s) {
+ Some(s) => Some(s),
+ None => None,
+ };
+}
--- /dev/null
- --> $DIR/manual_map_option.rs:14:5
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:19:5
++ --> $DIR/manual_map_option.rs:15:5
+ |
+LL | / match Some(0) {
+LL | | Some(_) => Some(2),
+LL | | None::<u32> => None,
+LL | | };
+ | |_____^ help: try this: `Some(0).map(|_| 2)`
+ |
+ = note: `-D clippy::manual-map` implied by `-D warnings`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:24:5
++ --> $DIR/manual_map_option.rs:20:5
+ |
+LL | / match Some(0) {
+LL | | Some(x) => Some(x + 1),
+LL | | _ => None,
+LL | | };
+ | |_____^ help: try this: `Some(0).map(|x| x + 1)`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:29:5
++ --> $DIR/manual_map_option.rs:25:5
+ |
+LL | / match Some("") {
+LL | | Some(x) => Some(x.is_empty()),
+LL | | None => None,
+LL | | };
+ | |_____^ help: try this: `Some("").map(|x| x.is_empty())`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:36:5
++ --> $DIR/manual_map_option.rs:30:5
+ |
+LL | / if let Some(x) = Some(0) {
+LL | | Some(!x)
+LL | | } else {
+LL | | None
+LL | | };
+ | |_____^ help: try this: `Some(0).map(|x| !x)`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:41:5
++ --> $DIR/manual_map_option.rs:37:5
+ |
+LL | / match Some(0) {
+LL | | Some(x) => { Some(std::convert::identity(x)) }
+LL | | None => { None }
+LL | | };
+ | |_____^ help: try this: `Some(0).map(std::convert::identity)`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:51:5
++ --> $DIR/manual_map_option.rs:42:5
+ |
+LL | / match Some(&String::new()) {
+LL | | Some(x) => Some(str::len(x)),
+LL | | None => None,
+LL | | };
+ | |_____^ help: try this: `Some(&String::new()).map(|x| str::len(x))`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:56:5
++ --> $DIR/manual_map_option.rs:52:5
+ |
+LL | / match &Some([0, 1]) {
+LL | | Some(x) => Some(x[0]),
+LL | | &None => None,
+LL | | };
+ | |_____^ help: try this: `Some([0, 1]).as_ref().map(|x| x[0])`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:61:5
++ --> $DIR/manual_map_option.rs:57:5
+ |
+LL | / match &Some(0) {
+LL | | &Some(x) => Some(x * 2),
+LL | | None => None,
+LL | | };
+ | |_____^ help: try this: `Some(0).map(|x| x * 2)`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:66:5
++ --> $DIR/manual_map_option.rs:62:5
+ |
+LL | / match Some(String::new()) {
+LL | | Some(ref x) => Some(x.is_empty()),
+LL | | _ => None,
+LL | | };
+ | |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.is_empty())`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:71:5
++ --> $DIR/manual_map_option.rs:67:5
+ |
+LL | / match &&Some(String::new()) {
+LL | | Some(x) => Some(x.len()),
+LL | | _ => None,
+LL | | };
+ | |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.len())`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:84:9
++ --> $DIR/manual_map_option.rs:72:5
+ |
+LL | / match &&Some(0) {
+LL | | &&Some(x) => Some(x + x),
+LL | | &&_ => None,
+LL | | };
+ | |_____^ help: try this: `Some(0).map(|x| x + x)`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:90:5
++ --> $DIR/manual_map_option.rs:85:9
+ |
+LL | / match &mut Some(String::new()) {
+LL | | Some(x) => Some(x.push_str("")),
+LL | | None => None,
+LL | | };
+ | |_________^ help: try this: `Some(String::new()).as_mut().map(|x| x.push_str(""))`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:95:5
++ --> $DIR/manual_map_option.rs:91:5
+ |
+LL | / match &mut Some(String::new()) {
+LL | | Some(ref x) => Some(x.len()),
+LL | | None => None,
+LL | | };
+ | |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.len())`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:100:5
++ --> $DIR/manual_map_option.rs:96:5
+ |
+LL | / match &mut &Some(String::new()) {
+LL | | Some(x) => Some(x.is_empty()),
+LL | | &mut _ => None,
+LL | | };
+ | |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.is_empty())`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:105:5
++ --> $DIR/manual_map_option.rs:101:5
+ |
+LL | / match Some((0, 1, 2)) {
+LL | | Some((x, y, z)) => Some(x + y + z),
+LL | | None => None,
+LL | | };
+ | |_____^ help: try this: `Some((0, 1, 2)).map(|(x, y, z)| x + y + z)`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:110:5
++ --> $DIR/manual_map_option.rs:106:5
+ |
+LL | / match Some([1, 2, 3]) {
+LL | | Some([first, ..]) => Some(first),
+LL | | None => None,
+LL | | };
+ | |_____^ help: try this: `Some([1, 2, 3]).map(|[first, ..]| first)`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:168:5
++ --> $DIR/manual_map_option.rs:111:5
+ |
+LL | / match &Some((String::new(), "test")) {
+LL | | Some((x, y)) => Some((y, x)),
+LL | | None => None,
+LL | | };
+ | |_____^ help: try this: `Some((String::new(), "test")).as_ref().map(|(x, y)| (y, x))`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:173:5
++ --> $DIR/manual_map_option.rs:169:5
+ |
+LL | / match Some(0) {
+LL | | Some(x) => Some(vec![x]),
+LL | | None => None,
+LL | | };
+ | |_____^ help: try this: `Some(0).map(|x| vec![x])`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:193:12
++ --> $DIR/manual_map_option.rs:174:5
+ |
+LL | / match option_env!("") {
+LL | | Some(x) => Some(String::from(x)),
+LL | | None => None,
+LL | | };
+ | |_____^ help: try this: `option_env!("").map(String::from)`
+
+error: manual implementation of `Option::map`
- --> $DIR/manual_map_option.rs:201:12
++ --> $DIR/manual_map_option.rs:194:12
+ |
+LL | } else if let Some(x) = Some(0) {
+ | ____________^
+LL | | Some(x + 1)
+LL | | } else {
+LL | | None
+LL | | };
+ | |_____^ help: try this: `{ Some(0).map(|x| x + 1) }`
+
+error: manual implementation of `Option::map`
++ --> $DIR/manual_map_option.rs:202:12
+ |
+LL | } else if let Some(x) = Some(0) {
+ | ____________^
+LL | | Some(x + 1)
+LL | | } else {
+LL | | None
+LL | | };
+ | |_____^ help: try this: `{ Some(0).map(|x| x + 1) }`
+
+error: aborting due to 21 previous errors
+
--- /dev/null
+// run-rustfix
+
++#![feature(lint_reasons)]
++
+#[warn(clippy::all, clippy::needless_borrow)]
+#[allow(unused_variables, clippy::unnecessary_mut_passed)]
+fn main() {
+ let a = 5;
+ let ref_a = &a;
+ let _ = x(&a); // no warning
+ let _ = x(&a); // warn
+
+ let mut b = 5;
+ mut_ref(&mut b); // no warning
+ mut_ref(&mut b); // warn
+
+ let s = &String::from("hi");
+ let s_ident = f(&s); // should not error, because `&String` implements Copy, but `String` does not
+ let g_val = g(&Vec::new()); // should not error, because `&Vec<T>` derefs to `&[T]`
+ let vec = Vec::new();
+ let vec_val = g(&vec); // should not error, because `&Vec<T>` derefs to `&[T]`
+ h(&"foo"); // should not error, because the `&&str` is required, due to `&Trait`
+ let garbl = match 42 {
+ 44 => &a,
+ 45 => {
+ println!("foo");
+ &a
+ },
+ 46 => &a,
+ 47 => {
+ println!("foo");
+ loop {
+ println!("{}", a);
+ if a == 25 {
+ break ref_a;
+ }
+ }
+ },
+ _ => panic!(),
+ };
+
+ let _ = x(&a);
+ let _ = x(&a);
+ let _ = x(&mut b);
+ let _ = x(ref_a);
+ {
+ let b = &mut b;
+ x(b);
+ }
+
+ // Issue #8191
+ let mut x = 5;
+ let mut x = &mut x;
+
+ mut_ref(x);
+ mut_ref(x);
+ let y: &mut i32 = x;
+ let y: &mut i32 = x;
+
+ let y = match 0 {
+ // Don't lint. Removing the borrow would move 'x'
+ 0 => &mut x,
+ _ => &mut *x,
+ };
+
+ *x = 5;
+
+ let s = String::new();
+ // let _ = (&s).len();
+ // let _ = (&s).capacity();
+ // let _ = (&&s).capacity();
+
+ let x = (1, 2);
+ let _ = x.0;
+ let x = &x as *const (i32, i32);
+ let _ = unsafe { (*x).0 };
+}
+
+#[allow(clippy::needless_borrowed_reference)]
+fn x(y: &i32) -> i32 {
+ *y
+}
+
+fn mut_ref(y: &mut i32) {
+ *y = 5;
+}
+
+fn f<T: Copy>(y: &T) -> T {
+ *y
+}
+
+fn g(y: &[u8]) -> u8 {
+ y[0]
+}
+
+trait Trait {}
+
+impl<'a> Trait for &'a str {}
+
+fn h(_: &dyn Trait) {}
++
++#[allow(dead_code)]
++fn check_expect_suppression() {
++ let a = 5;
++ #[expect(clippy::needless_borrow)]
++ let _ = x(&&a);
++}
--- /dev/null
+// run-rustfix
+
++#![feature(lint_reasons)]
++
+#[warn(clippy::all, clippy::needless_borrow)]
+#[allow(unused_variables, clippy::unnecessary_mut_passed)]
+fn main() {
+ let a = 5;
+ let ref_a = &a;
+ let _ = x(&a); // no warning
+ let _ = x(&&a); // warn
+
+ let mut b = 5;
+ mut_ref(&mut b); // no warning
+ mut_ref(&mut &mut b); // warn
+
+ let s = &String::from("hi");
+ let s_ident = f(&s); // should not error, because `&String` implements Copy, but `String` does not
+ let g_val = g(&Vec::new()); // should not error, because `&Vec<T>` derefs to `&[T]`
+ let vec = Vec::new();
+ let vec_val = g(&vec); // should not error, because `&Vec<T>` derefs to `&[T]`
+ h(&"foo"); // should not error, because the `&&str` is required, due to `&Trait`
+ let garbl = match 42 {
+ 44 => &a,
+ 45 => {
+ println!("foo");
+ &&a
+ },
+ 46 => &&a,
+ 47 => {
+ println!("foo");
+ loop {
+ println!("{}", a);
+ if a == 25 {
+ break &ref_a;
+ }
+ }
+ },
+ _ => panic!(),
+ };
+
+ let _ = x(&&&a);
+ let _ = x(&mut &&a);
+ let _ = x(&&&mut b);
+ let _ = x(&&ref_a);
+ {
+ let b = &mut b;
+ x(&b);
+ }
+
+ // Issue #8191
+ let mut x = 5;
+ let mut x = &mut x;
+
+ mut_ref(&mut x);
+ mut_ref(&mut &mut x);
+ let y: &mut i32 = &mut x;
+ let y: &mut i32 = &mut &mut x;
+
+ let y = match 0 {
+ // Don't lint. Removing the borrow would move 'x'
+ 0 => &mut x,
+ _ => &mut *x,
+ };
+
+ *x = 5;
+
+ let s = String::new();
+ // let _ = (&s).len();
+ // let _ = (&s).capacity();
+ // let _ = (&&s).capacity();
+
+ let x = (1, 2);
+ let _ = (&x).0;
+ let x = &x as *const (i32, i32);
+ let _ = unsafe { (&*x).0 };
+}
+
+#[allow(clippy::needless_borrowed_reference)]
+fn x(y: &i32) -> i32 {
+ *y
+}
+
+fn mut_ref(y: &mut i32) {
+ *y = 5;
+}
+
+fn f<T: Copy>(y: &T) -> T {
+ *y
+}
+
+fn g(y: &[u8]) -> u8 {
+ y[0]
+}
+
+trait Trait {}
+
+impl<'a> Trait for &'a str {}
+
+fn h(_: &dyn Trait) {}
++
++#[allow(dead_code)]
++fn check_expect_suppression() {
++ let a = 5;
++ #[expect(clippy::needless_borrow)]
++ let _ = x(&&a);
++}
--- /dev/null
- --> $DIR/needless_borrow.rs:9:15
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:13:13
++ --> $DIR/needless_borrow.rs:11:15
+ |
+LL | let _ = x(&&a); // warn
+ | ^^^ help: change this to: `&a`
+ |
+ = note: `-D clippy::needless-borrow` implied by `-D warnings`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:25:13
++ --> $DIR/needless_borrow.rs:15:13
+ |
+LL | mut_ref(&mut &mut b); // warn
+ | ^^^^^^^^^^^ help: change this to: `&mut b`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:27:15
++ --> $DIR/needless_borrow.rs:27:13
+ |
+LL | &&a
+ | ^^^ help: change this to: `&a`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:33:27
++ --> $DIR/needless_borrow.rs:29:15
+ |
+LL | 46 => &&a,
+ | ^^^ help: change this to: `&a`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:40:15
++ --> $DIR/needless_borrow.rs:35:27
+ |
+LL | break &ref_a;
+ | ^^^^^^ help: change this to: `ref_a`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:41:15
++ --> $DIR/needless_borrow.rs:42:15
+ |
+LL | let _ = x(&&&a);
+ | ^^^^ help: change this to: `&a`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:42:15
++ --> $DIR/needless_borrow.rs:43:15
+ |
+LL | let _ = x(&mut &&a);
+ | ^^^^^^^^ help: change this to: `&a`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:43:15
++ --> $DIR/needless_borrow.rs:44:15
+ |
+LL | let _ = x(&&&mut b);
+ | ^^^^^^^^ help: change this to: `&mut b`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:46:11
++ --> $DIR/needless_borrow.rs:45:15
+ |
+LL | let _ = x(&&ref_a);
+ | ^^^^^^^ help: change this to: `ref_a`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:53:13
++ --> $DIR/needless_borrow.rs:48:11
+ |
+LL | x(&b);
+ | ^^ help: change this to: `b`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:54:13
++ --> $DIR/needless_borrow.rs:55:13
+ |
+LL | mut_ref(&mut x);
+ | ^^^^^^ help: change this to: `x`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:55:23
++ --> $DIR/needless_borrow.rs:56:13
+ |
+LL | mut_ref(&mut &mut x);
+ | ^^^^^^^^^^^ help: change this to: `x`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:56:23
++ --> $DIR/needless_borrow.rs:57:23
+ |
+LL | let y: &mut i32 = &mut x;
+ | ^^^^^^ help: change this to: `x`
+
+error: this expression creates a reference which is immediately dereferenced by the compiler
- --> $DIR/needless_borrow.rs:72:13
++ --> $DIR/needless_borrow.rs:58:23
+ |
+LL | let y: &mut i32 = &mut &mut x;
+ | ^^^^^^^^^^^ help: change this to: `x`
+
+error: this expression borrows a value the compiler would automatically borrow
- --> $DIR/needless_borrow.rs:74:22
++ --> $DIR/needless_borrow.rs:74:13
+ |
+LL | let _ = (&x).0;
+ | ^^^^ help: change this to: `x`
+
+error: this expression borrows a value the compiler would automatically borrow
++ --> $DIR/needless_borrow.rs:76:22
+ |
+LL | let _ = unsafe { (&*x).0 };
+ | ^^^^^ help: change this to: `(*x)`
+
+error: aborting due to 16 previous errors
+
--- /dev/null
--- /dev/null
++// run-rustfix
++// edition:2018
++
++#![warn(clippy::needless_parens_on_range_literals)]
++#![allow(clippy::almost_complete_letter_range)]
++
++fn main() {
++ let _ = 'a'..='z';
++ let _ = 'a'..'z';
++ let _ = (1.)..2.;
++ let _ = (1.)..2.;
++ let _ = 'a'..;
++ let _ = ..'z';
++}
--- /dev/null
--- /dev/null
++// run-rustfix
++// edition:2018
++
++#![warn(clippy::needless_parens_on_range_literals)]
++#![allow(clippy::almost_complete_letter_range)]
++
++fn main() {
++ let _ = ('a')..=('z');
++ let _ = 'a'..('z');
++ let _ = (1.)..2.;
++ let _ = (1.)..(2.);
++ let _ = ('a')..;
++ let _ = ..('z');
++}
--- /dev/null
--- /dev/null
++error: needless parenthesis on range literals can be removed
++ --> $DIR/needless_parens_on_range_literals.rs:8:13
++ |
++LL | let _ = ('a')..=('z');
++ | ^^^^^ help: try: `'a'`
++ |
++ = note: `-D clippy::needless-parens-on-range-literals` implied by `-D warnings`
++
++error: needless parenthesis on range literals can be removed
++ --> $DIR/needless_parens_on_range_literals.rs:8:21
++ |
++LL | let _ = ('a')..=('z');
++ | ^^^^^ help: try: `'z'`
++
++error: needless parenthesis on range literals can be removed
++ --> $DIR/needless_parens_on_range_literals.rs:9:18
++ |
++LL | let _ = 'a'..('z');
++ | ^^^^^ help: try: `'z'`
++
++error: needless parenthesis on range literals can be removed
++ --> $DIR/needless_parens_on_range_literals.rs:11:19
++ |
++LL | let _ = (1.)..(2.);
++ | ^^^^ help: try: `2.`
++
++error: needless parenthesis on range literals can be removed
++ --> $DIR/needless_parens_on_range_literals.rs:12:13
++ |
++LL | let _ = ('a')..;
++ | ^^^^^ help: try: `'a'`
++
++error: needless parenthesis on range literals can be removed
++ --> $DIR/needless_parens_on_range_literals.rs:13:15
++ |
++LL | let _ = ..('z');
++ | ^^^^^ help: try: `'z'`
++
++error: aborting due to 6 previous errors
++
--- /dev/null
+#![allow(
+ clippy::single_match,
+ unused_assignments,
+ unused_variables,
+ clippy::while_immutable_condition
+)]
+
+fn test1() {
+ let mut x = 0;
+ loop {
+ // clippy::never_loop
+ x += 1;
+ if x == 1 {
+ return;
+ }
+ break;
+ }
+}
+
+fn test2() {
+ let mut x = 0;
+ loop {
+ x += 1;
+ if x == 1 {
+ break;
+ }
+ }
+}
+
+fn test3() {
+ let mut x = 0;
+ loop {
+ // never loops
+ x += 1;
+ break;
+ }
+}
+
+fn test4() {
+ let mut x = 1;
+ loop {
+ x += 1;
+ match x {
+ 5 => return,
+ _ => (),
+ }
+ }
+}
+
+fn test5() {
+ let i = 0;
+ loop {
+ // never loops
+ while i == 0 {
+ // never loops
+ break;
+ }
+ return;
+ }
+}
+
+fn test6() {
+ let mut x = 0;
+ 'outer: loop {
+ x += 1;
+ loop {
+ // never loops
+ if x == 5 {
+ break;
+ }
+ continue 'outer;
+ }
+ return;
+ }
+}
+
+fn test7() {
+ let mut x = 0;
+ loop {
+ x += 1;
+ match x {
+ 1 => continue,
+ _ => (),
+ }
+ return;
+ }
+}
+
+fn test8() {
+ let mut x = 0;
+ loop {
+ x += 1;
+ match x {
+ 5 => return,
+ _ => continue,
+ }
+ }
+}
+
+fn test9() {
+ let x = Some(1);
+ while let Some(y) = x {
+ // never loops
+ return;
+ }
+}
+
+fn test10() {
+ for x in 0..10 {
+ // never loops
+ match x {
+ 1 => break,
+ _ => return,
+ }
+ }
+}
+
+fn test11<F: FnMut() -> i32>(mut f: F) {
+ loop {
+ return match f() {
+ 1 => continue,
+ _ => (),
+ };
+ }
+}
+
+pub fn test12(a: bool, b: bool) {
+ 'label: loop {
+ loop {
+ if a {
+ continue 'label;
+ }
+ if b {
+ break;
+ }
+ }
+ break;
+ }
+}
+
+pub fn test13() {
+ let mut a = true;
+ loop {
+ // infinite loop
+ while a {
+ if true {
+ a = false;
+ continue;
+ }
+ return;
+ }
+ }
+}
+
+pub fn test14() {
+ let mut a = true;
+ 'outer: while a {
+ // never loops
+ while a {
+ if a {
+ a = false;
+ continue;
+ }
+ }
+ break 'outer;
+ }
+}
+
+// Issue #1991: the outer loop should not warn.
+pub fn test15() {
+ 'label: loop {
+ while false {
+ break 'label;
+ }
+ }
+}
+
+// Issue #4058: `continue` in `break` expression
+pub fn test16() {
+ let mut n = 1;
+ loop {
+ break if n != 5 {
+ n += 1;
+ continue;
+ };
+ }
+}
+
++// Issue #9001: `continue` in struct expression fields
++pub fn test17() {
++ struct Foo {
++ f: (),
++ }
++
++ let mut n = 0;
++ let _ = loop {
++ break Foo {
++ f: if n < 5 {
++ n += 1;
++ continue;
++ },
++ };
++ };
++}
++
+fn main() {
+ test1();
+ test2();
+ test3();
+ test4();
+ test5();
+ test6();
+ test7();
+ test8();
+ test9();
+ test10();
+ test11(|| 0);
+ test12(true, false);
+ test13();
+ test14();
+}
--- /dev/null
--- /dev/null
++#![warn(clippy::read_zero_byte_vec)]
++#![allow(clippy::unused_io_amount)]
++use std::fs::File;
++use std::io;
++use std::io::prelude::*;
++
++extern crate futures;
++use futures::io::{AsyncRead, AsyncReadExt};
++use tokio::io::{AsyncRead as TokioAsyncRead, AsyncReadExt as _, AsyncWrite as TokioAsyncWrite, AsyncWriteExt as _};
++
++fn test() -> io::Result<()> {
++ let cap = 1000;
++ let mut f = File::open("foo.txt").unwrap();
++
++ // should lint
++ let mut data = Vec::with_capacity(20);
++ f.read_exact(&mut data).unwrap();
++
++ // should lint
++ let mut data2 = Vec::with_capacity(cap);
++ f.read_exact(&mut data2)?;
++
++ // should lint
++ let mut data3 = Vec::new();
++ f.read_exact(&mut data3)?;
++
++ // should lint
++ let mut data4 = vec![];
++ let _ = f.read(&mut data4)?;
++
++ // should lint
++ let _ = {
++ let mut data5 = Vec::new();
++ f.read(&mut data5)
++ };
++
++ // should lint
++ let _ = {
++ let mut data6: Vec<u8> = Default::default();
++ f.read(&mut data6)
++ };
++
++ // should not lint
++ let mut buf = [0u8; 100];
++ f.read(&mut buf)?;
++
++ // should not lint
++ let mut empty = vec![];
++ let mut data7 = vec![];
++ f.read(&mut empty);
++
++ // should not lint
++ f.read(&mut data7);
++
++ // should not lint
++ let mut data8 = Vec::new();
++ data8.resize(100, 0);
++ f.read_exact(&mut data8)?;
++
++ // should not lint
++ let mut data9 = vec![1, 2, 3];
++ f.read_exact(&mut data9)?;
++
++ Ok(())
++}
++
++async fn test_futures<R: AsyncRead + Unpin>(r: &mut R) {
++ // should lint
++ let mut data = Vec::new();
++ r.read(&mut data).await.unwrap();
++
++ // should lint
++ let mut data2 = Vec::new();
++ r.read_exact(&mut data2).await.unwrap();
++}
++
++async fn test_tokio<R: TokioAsyncRead + Unpin>(r: &mut R) {
++ // should lint
++ let mut data = Vec::new();
++ r.read(&mut data).await.unwrap();
++
++ // should lint
++ let mut data2 = Vec::new();
++ r.read_exact(&mut data2).await.unwrap();
++}
++
++fn main() {}
--- /dev/null
--- /dev/null
++error: reading zero byte data to `Vec`
++ --> $DIR/read_zero_byte_vec.rs:17:5
++ |
++LL | f.read_exact(&mut data).unwrap();
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `data.resize(20, 0); f.read_exact(&mut data).unwrap();`
++ |
++ = note: `-D clippy::read-zero-byte-vec` implied by `-D warnings`
++
++error: reading zero byte data to `Vec`
++ --> $DIR/read_zero_byte_vec.rs:21:5
++ |
++LL | f.read_exact(&mut data2)?;
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `data2.resize(cap, 0); f.read_exact(&mut data2)?;`
++
++error: reading zero byte data to `Vec`
++ --> $DIR/read_zero_byte_vec.rs:25:5
++ |
++LL | f.read_exact(&mut data3)?;
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: reading zero byte data to `Vec`
++ --> $DIR/read_zero_byte_vec.rs:29:5
++ |
++LL | let _ = f.read(&mut data4)?;
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: reading zero byte data to `Vec`
++ --> $DIR/read_zero_byte_vec.rs:34:9
++ |
++LL | f.read(&mut data5)
++ | ^^^^^^^^^^^^^^^^^^
++
++error: reading zero byte data to `Vec`
++ --> $DIR/read_zero_byte_vec.rs:40:9
++ |
++LL | f.read(&mut data6)
++ | ^^^^^^^^^^^^^^^^^^
++
++error: reading zero byte data to `Vec`
++ --> $DIR/read_zero_byte_vec.rs:70:5
++ |
++LL | r.read(&mut data).await.unwrap();
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: reading zero byte data to `Vec`
++ --> $DIR/read_zero_byte_vec.rs:74:5
++ |
++LL | r.read_exact(&mut data2).await.unwrap();
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: reading zero byte data to `Vec`
++ --> $DIR/read_zero_byte_vec.rs:80:5
++ |
++LL | r.read(&mut data).await.unwrap();
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: reading zero byte data to `Vec`
++ --> $DIR/read_zero_byte_vec.rs:84:5
++ |
++LL | r.read_exact(&mut data2).await.unwrap();
++ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++error: aborting due to 10 previous errors
++
--- /dev/null
+// FIXME: run-rustfix waiting on multi-span suggestions
+
++#![feature(lint_reasons)]
+#![warn(clippy::ref_binding_to_reference)]
+#![allow(clippy::needless_borrowed_reference)]
+
+fn f1(_: &str) {}
+macro_rules! m2 {
+ ($e:expr) => {
+ f1(*$e)
+ };
+}
+macro_rules! m3 {
+ ($i:ident) => {
+ Some(ref $i)
+ };
+}
+
+#[allow(dead_code)]
+fn main() {
+ let x = String::new();
+
+ // Ok, the pattern is from a macro
+ let _: &&String = match Some(&x) {
+ m3!(x) => x,
+ None => return,
+ };
+
+ // Err, reference to a &String
+ let _: &&String = match Some(&x) {
+ Some(ref x) => x,
+ None => return,
+ };
+
+ // Err, reference to a &String
+ let _: &&String = match Some(&x) {
+ Some(ref x) => {
+ f1(x);
+ f1(*x);
+ x
+ },
+ None => return,
+ };
+
+ // Err, reference to a &String
+ match Some(&x) {
+ Some(ref x) => m2!(x),
+ None => return,
+ }
+
+ // Err, reference to a &String
+ let _ = |&ref x: &&String| {
+ let _: &&String = x;
+ };
+}
+
+// Err, reference to a &String
+fn f2<'a>(&ref x: &&'a String) -> &'a String {
+ let _: &&String = x;
+ *x
+}
+
+trait T1 {
+ // Err, reference to a &String
+ fn f(&ref x: &&String) {
+ let _: &&String = x;
+ }
+}
+
+struct S;
+impl T1 for S {
+ // Err, reference to a &String
+ fn f(&ref x: &&String) {
+ let _: &&String = x;
+ }
+}
++
++fn check_expect_suppression() {
++ let x = String::new();
++ #[expect(clippy::ref_binding_to_reference)]
++ let _: &&String = match Some(&x) {
++ Some(ref x) => x,
++ None => return,
++ };
++}
--- /dev/null
- --> $DIR/ref_binding_to_reference.rs:30:14
+error: this pattern creates a reference to a reference
- --> $DIR/ref_binding_to_reference.rs:36:14
++ --> $DIR/ref_binding_to_reference.rs:31:14
+ |
+LL | Some(ref x) => x,
+ | ^^^^^
+ |
+ = note: `-D clippy::ref-binding-to-reference` implied by `-D warnings`
+help: try this
+ |
+LL | Some(x) => &x,
+ | ~ ~~
+
+error: this pattern creates a reference to a reference
- --> $DIR/ref_binding_to_reference.rs:46:14
++ --> $DIR/ref_binding_to_reference.rs:37:14
+ |
+LL | Some(ref x) => {
+ | ^^^^^
+ |
+help: try this
+ |
+LL ~ Some(x) => {
+LL | f1(x);
+LL ~ f1(x);
+LL ~ &x
+ |
+
+error: this pattern creates a reference to a reference
- --> $DIR/ref_binding_to_reference.rs:51:15
++ --> $DIR/ref_binding_to_reference.rs:47:14
+ |
+LL | Some(ref x) => m2!(x),
+ | ^^^^^
+ |
+help: try this
+ |
+LL | Some(x) => m2!(&x),
+ | ~ ~~
+
+error: this pattern creates a reference to a reference
- --> $DIR/ref_binding_to_reference.rs:57:12
++ --> $DIR/ref_binding_to_reference.rs:52:15
+ |
+LL | let _ = |&ref x: &&String| {
+ | ^^^^^
+ |
+help: try this
+ |
+LL ~ let _ = |&x: &&String| {
+LL ~ let _: &&String = &x;
+ |
+
+error: this pattern creates a reference to a reference
- --> $DIR/ref_binding_to_reference.rs:64:11
++ --> $DIR/ref_binding_to_reference.rs:58:12
+ |
+LL | fn f2<'a>(&ref x: &&'a String) -> &'a String {
+ | ^^^^^
+ |
+help: try this
+ |
+LL ~ fn f2<'a>(&x: &&'a String) -> &'a String {
+LL ~ let _: &&String = &x;
+LL ~ x
+ |
+
+error: this pattern creates a reference to a reference
- --> $DIR/ref_binding_to_reference.rs:72:11
++ --> $DIR/ref_binding_to_reference.rs:65:11
+ |
+LL | fn f(&ref x: &&String) {
+ | ^^^^^
+ |
+help: try this
+ |
+LL ~ fn f(&x: &&String) {
+LL ~ let _: &&String = &x;
+ |
+
+error: this pattern creates a reference to a reference
++ --> $DIR/ref_binding_to_reference.rs:73:11
+ |
+LL | fn f(&ref x: &&String) {
+ | ^^^^^
+ |
+help: try this
+ |
+LL ~ fn f(&x: &&String) {
+LL ~ let _: &&String = &x;
+ |
+
+error: aborting due to 7 previous errors
+
--- /dev/null
++#![feature(lint_reasons)]
+#![warn(clippy::same_name_method)]
+#![allow(dead_code, non_camel_case_types)]
+
+trait T1 {
+ fn foo() {}
+}
+
+trait T2 {
+ fn foo() {}
+}
+
+mod should_lint {
+
+ mod test_basic_case {
+ use crate::T1;
+
+ struct S;
+
+ impl S {
+ fn foo() {}
+ }
+
+ impl T1 for S {
+ fn foo() {}
+ }
+ }
+
+ mod test_derive {
+
+ #[derive(Clone)]
+ struct S;
+
+ impl S {
+ fn clone() {}
+ }
+ }
+
+ mod with_generic {
+ use crate::T1;
+
+ struct S<U>(U);
+
+ impl<U> S<U> {
+ fn foo() {}
+ }
+
+ impl<U: Copy> T1 for S<U> {
+ fn foo() {}
+ }
+ }
+
+ mod default_method {
+ use crate::T1;
+
+ struct S;
+
+ impl S {
+ fn foo() {}
+ }
+
+ impl T1 for S {}
+ }
+
+ mod mulitply_conflicit_trait {
+ use crate::{T1, T2};
+
+ struct S;
+
+ impl S {
+ fn foo() {}
+ }
+
+ impl T1 for S {}
+
+ impl T2 for S {}
+ }
+}
+
+mod should_not_lint {
+
+ mod not_lint_two_trait_method {
+ use crate::{T1, T2};
+
+ struct S;
+
+ impl T1 for S {
+ fn foo() {}
+ }
+
+ impl T2 for S {
+ fn foo() {}
+ }
+ }
+
+ mod only_lint_on_method {
+ trait T3 {
+ type foo;
+ }
+
+ struct S;
+
+ impl S {
+ fn foo() {}
+ }
+ impl T3 for S {
+ type foo = usize;
+ }
+ }
+}
+
++mod check_expect_suppression {
++ use crate::T1;
++
++ struct S;
++
++ impl S {
++ #[expect(clippy::same_name_method)]
++ fn foo() {}
++ }
++
++ impl T1 for S {
++ fn foo() {}
++ }
++}
++
+fn main() {}
--- /dev/null
- --> $DIR/same_name_method.rs:20:13
+error: method's name is the same as an existing method in a trait
- --> $DIR/same_name_method.rs:24:13
++ --> $DIR/same_name_method.rs:21:13
+ |
+LL | fn foo() {}
+ | ^^^^^^^^^^^
+ |
+ = note: `-D clippy::same-name-method` implied by `-D warnings`
+note: existing `foo` defined here
- --> $DIR/same_name_method.rs:34:13
++ --> $DIR/same_name_method.rs:25:13
+ |
+LL | fn foo() {}
+ | ^^^^^^^^^^^
+
+error: method's name is the same as an existing method in a trait
- --> $DIR/same_name_method.rs:30:18
++ --> $DIR/same_name_method.rs:35:13
+ |
+LL | fn clone() {}
+ | ^^^^^^^^^^^^^
+ |
+note: existing `clone` defined here
- --> $DIR/same_name_method.rs:44:13
++ --> $DIR/same_name_method.rs:31:18
+ |
+LL | #[derive(Clone)]
+ | ^^^^^
+ = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: method's name is the same as an existing method in a trait
- --> $DIR/same_name_method.rs:48:13
++ --> $DIR/same_name_method.rs:45:13
+ |
+LL | fn foo() {}
+ | ^^^^^^^^^^^
+ |
+note: existing `foo` defined here
- --> $DIR/same_name_method.rs:58:13
++ --> $DIR/same_name_method.rs:49:13
+ |
+LL | fn foo() {}
+ | ^^^^^^^^^^^
+
+error: method's name is the same as an existing method in a trait
- --> $DIR/same_name_method.rs:61:9
++ --> $DIR/same_name_method.rs:59:13
+ |
+LL | fn foo() {}
+ | ^^^^^^^^^^^
+ |
+note: existing `foo` defined here
- --> $DIR/same_name_method.rs:70:13
++ --> $DIR/same_name_method.rs:62:9
+ |
+LL | impl T1 for S {}
+ | ^^^^^^^^^^^^^^^^
+
+error: method's name is the same as an existing method in a trait
- --> $DIR/same_name_method.rs:73:9
++ --> $DIR/same_name_method.rs:71:13
+ |
+LL | fn foo() {}
+ | ^^^^^^^^^^^
+ |
+note: existing `foo` defined here
++ --> $DIR/same_name_method.rs:74:9
+ |
+LL | impl T1 for S {}
+ | ^^^^^^^^^^^^^^^^
+
+error: aborting due to 5 previous errors
+
--- /dev/null
+<!DOCTYPE html>
+<!--
+Welcome to a Clippy's lint list, at least the source code of it. If you are
+interested in contributing to this website checkout `util/gh-pages/index.html`
+inside the rust-clippy repository.
+
+Otherwise, have a great day =^.^=
+-->
+<html lang="en">
+<head>
+ <meta charset="UTF-8"/>
+ <meta name="viewport" content="width=device-width, initial-scale=1"/>
+
+ <title>Clippy Lints</title>
+
+ <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.6/css/bootstrap.min.css"/>
+ <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.5.0/styles/github.min.css"/>
+
+ <!-- The files are not copied over into the Clippy project since they use the MPL-2.0 License -->
+ <link rel="stylesheet" href="https://rust-lang.github.io/mdBook/css/variables.css"/>
+ <link id="styleHighlight" rel="stylesheet" href="https://rust-lang.github.io/mdBook/highlight.css">
+ <link id="styleNight" rel="stylesheet" href="https://rust-lang.github.io/mdBook/tomorrow-night.css" disabled="true">
+ <link id="styleAyu" rel="stylesheet" href="https://rust-lang.github.io/mdBook/ayu-highlight.css" disabled="true">
+ <style>
+ blockquote { font-size: 1em; }
+ [ng\:cloak], [ng-cloak], [data-ng-cloak], [x-ng-cloak], .ng-cloak, .x-ng-cloak { display: none !important; }
+
+ .dropdown-menu {
+ color: var(--fg);
+ background: var(--theme-popup-bg);
+ border: 1px solid var(--theme-popup-border);
+ }
+
+ .dropdown-menu .divider {
+ background-color: var(--theme-popup-border);
+ }
+
+ .dropdown-menu .checkbox {
+ display: block;
+ white-space: nowrap;
+ margin: 0;
+ }
+ .dropdown-menu .checkbox label {
+ padding: 3px 20px;
+ width: 100%;
+ }
+
+ .dropdown-menu .checkbox input {
+ position: relative;
+ margin: 0 0.5rem 0;
+ padding: 0;
+ }
+
+ .dropdown-menu .checkbox:hover {
+ background-color: var(--theme-hover);
+ }
+
+ div.panel div.panel-body button.dropdown-toggle {
+ background: var(--searchbar-bg);
+ color: var(--searchbar-fg);
+ border-color: var(--theme-popup-border);
+ }
+
+ div.panel div.panel-body button.dropdown-toggle:hover {
+ box-shadow: 0 0 3px var(--searchbar-shadow-color);
+ }
+
+ div.panel div.panel-body .open button.dropdown-toggle {
+ background: var(--searchbar-bg);
+ color: var(--searchbar-fg);
+ border-color: var(--theme-popup-border);
+ filter: brightness(90%);
+ }
+
+ .dropdown-toggle .badge {
+ background-color: #777;
+ }
+
+ .panel-heading { cursor: pointer; }
+
+ .panel-title { display: flex; flex-wrap: wrap;}
+ .panel-title .label { display: inline-block; }
+
+ .panel-title-name { flex: 1; min-width: 400px;}
+ .panel-title-name span { vertical-align: bottom; }
+
+ .panel .panel-title-name .anchor { display: none; }
+ .panel:hover .panel-title-name .anchor { display: inline;}
+
+ .search-control {
+ margin-top: 15px;
+ }
+
+ @media (min-width: 992px) {
+ .search-control {
+ margin-top: 0;
+ float: right;
+ }
+ }
+
+ @media (min-width: 405px) {
+ #upper-filters {
+ display: flex;
+ }
+ }
+
+ @media (max-width: 430px) {
+ /* Turn the version filter list to the left */
+ #version-filter-selector {
+ right: 0;
+ left: auto;
+ }
+ }
+
+ @media (max-width: 412px) {
+ #upper-filters,
+ .panel-body .search-control {
+ padding-right: 8px;
+ padding-left: 8px;
+ }
+ }
+
+ .label {
+ padding-top: 0.3em;
+ padding-bottom: 0.3em;
+ }
+
+ .label-lint-group {
+ min-width: 8em;
+ }
+ .label-lint-level {
+ min-width: 4em;
+ }
+
+ .label-lint-level-allow {
+ background-color: #5cb85c;
+ }
+ .label-lint-level-warn {
+ background-color: #f0ad4e;
+ }
+ .label-lint-level-deny {
+ background-color: #d9534f;
+ }
+ .label-lint-level-none {
+ background-color: #777777;
+ opacity: 0.5;
+ }
+
+ .label-group-deprecated {
+ opacity: 0.5;
+ }
+
+ .label-doc-folding {
+ color: #000;
+ background-color: #fff;
+ border: 1px solid var(--theme-popup-border);
+ }
+ .label-doc-folding:hover {
+ background-color: #e6e6e6;
+ }
+
+ .lint-doc-md > h3 {
+ border-top: 1px solid var(--theme-popup-border);
+ padding: 10px 15px;
+ margin: 0 -15px;
+ font-size: 18px;
+ }
+ .lint-doc-md > h3:first-child {
+ border-top: none;
+ padding-top: 0px;
+ }
+
+ @media (max-width:749px) {
+ .lint-additional-info-container {
+ display: flex;
+ flex-flow: column;
+ }
+ .lint-additional-info-item + .lint-additional-info-item {
+ border-top: 1px solid var(--theme-popup-border);
+ }
+ }
+ @media (min-width:750px) {
+ .lint-additional-info-container {
+ display: flex;
+ flex-flow: row;
+ }
+ .lint-additional-info-item + .lint-additional-info-item {
+ border-left: 1px solid var(--theme-popup-border);
+ }
+ }
+
+ .lint-additional-info-item {
+ display: inline-flex;
+ min-width: 200px;
+ flex-grow: 1;
+ padding: 9px 5px 5px 15px;
+ }
+
+ .label-applicability {
+ background-color: #777777;
+ margin: auto 5px;
+ }
+
+ .label-version {
+ background-color: #777777;
+ margin: auto 5px;
+ font-family: monospace;
+ }
++
++ details {
++ border-radius: 4px;
++ padding: .5em .5em 0;
++ }
++
++ code {
++ white-space: pre !important;
++ }
++
++ summary {
++ font-weight: bold;
++ margin: -.5em -.5em 0;
++ padding: .5em;
++ display: revert;
++ }
++
++ details[open] {
++ padding: .5em;
++ }
+ </style>
+ <style>
+ /* Expanding the mdBoom theme*/
+ .light {
+ --inline-code-bg: #f6f7f6;
+ }
+ .rust {
+ --inline-code-bg: #f6f7f6;
+ }
+ .coal {
+ --inline-code-bg: #1d1f21;
+ }
+ .navy {
+ --inline-code-bg: #1d1f21;
+ }
+ .ayu {
+ --inline-code-bg: #191f26;
+ }
+
+ .theme-dropdown {
+ position: absolute;
+ margin: 0.7em;
+ z-index: 10;
+ }
+
+ /* Applying the mdBook theme */
+ .theme-icon {
+ text-align: center;
+ width: 2em;
+ height: 2em;
+ line-height: 2em;
+ border: solid 1px var(--icons);
+ border-radius: 5px;
+ user-select: none;
+ cursor: pointer;
+ }
+ .theme-icon:hover {
+ background: var(--theme-hover);
+ }
+ .theme-choice {
+ display: none;
+ list-style: none;
+ border: 1px solid var(--theme-popup-border);
+ border-radius: 5px;
+ color: var(--fg);
+ background: var(--theme-popup-bg);
+ padding: 0 0;
+ overflow: hidden;
+ }
+
+ .theme-dropdown.open .theme-choice {
+ display: block;
+ }
+
+ .theme-choice > li {
+ padding: 5px 10px;
+ font-size: 0.8em;
+ user-select: none;
+ cursor: pointer;
+ }
+
+ .theme-choice > li:hover {
+ background: var(--theme-hover);
+ }
+
+ .alert {
+ color: var(--fg);
+ background: var(--theme-hover);
+ border: 1px solid var(--theme-popup-border);
+ }
+ .page-header {
+ border-color: var(--theme-popup-border);
+ }
+ .panel-default > .panel-heading {
+ background: var(--theme-hover);
+ color: var(--fg);
+ border: 1px solid var(--theme-popup-border);
+ }
+ .panel-default > .panel-heading:hover {
+ filter: brightness(90%);
+ }
+ .list-group-item {
+ background: 0%;
+ border: 1px solid var(--theme-popup-border);
+ }
+ .panel, pre, hr {
+ background: var(--bg);
+ border: 1px solid var(--theme-popup-border);
+ }
+
+ #version-filter-selector .checkbox {
+ display: flex;
+ }
+
+ #version-filter {
+ min-width: available;
+ }
+
+ #version-filter li label {
+ padding-right: 0;
+ width: 35%;
+ }
+
+ .version-filter-input {
+ height: 60%;
+ width: 30%;
+ text-align: center;
+ border: none;
+ border-bottom: 1px solid #000000;
+ }
+
+ #filter-label, .filter-clear {
+ background: var(--searchbar-bg);
+ color: var(--searchbar-fg);
+ border-color: var(--theme-popup-border);
+ filter: brightness(95%);
+ }
+ #filter-label:hover, .filter-clear:hover {
+ filter: brightness(90%);
+ }
+ .filter-input {
+ background: var(--searchbar-bg);
+ color: var(--searchbar-fg);
+ border-color: var(--theme-popup-border);
+ }
+
+ .filter-input::-webkit-input-placeholder,
+ .filter-input::-moz-placeholder {
+ color: var(--searchbar-fg);
+ opacity: 30%;
+ }
+
+ :not(pre) > code {
+ color: var(--inline-code-color);
+ background-color: var(--inline-code-bg);
+ }
+ html {
+ scrollbar-color: var(--scrollbar) var(--bg);
+ }
+ body {
+ background: var(--bg);
+ color: var(--fg);
+ }
+
+ </style>
+</head>
+<body ng-app="clippy" ng-controller="lintList">
+ <div theme-dropdown class="theme-dropdown">
+ <div id="theme-icon" class="theme-icon">🖌</div>
+ <ul id="theme-menu" class="theme-choice">
+ <li id="{{id}}" ng-repeat="(id, name) in themes" ng-click="selectTheme(id)">{{name}}</li>
+ </ul>
+ </div>
+
+ <div class="container">
+ <div class="page-header">
+ <h1>Clippy Lints</h1>
+ </div>
+
+ <noscript>
+ <div class="alert alert-danger" role="alert">
+ Sorry, this site only works with JavaScript! :(
+ </div>
+ </noscript>
+
+ <div ng-cloak>
+
+ <div class="alert alert-info" role="alert" ng-if="loading">
+ Loading…
+ </div>
+ <div class="alert alert-danger" role="alert" ng-if="error">
+ Error loading lints!
+ </div>
+
+ <div class="panel panel-default" ng-show="data">
+ <div class="panel-body row">
+ <div id="upper-filters" class="col-12 col-md-4">
+ <div class="btn-group" filter-dropdown>
+ <button type="button" class="btn btn-default dropdown-toggle">
+ Lint levels <span class="badge">{{selectedValuesCount(levels)}}</span> <span class="caret"></span>
+ </button>
+ <ul class="dropdown-menu">
+ <li class="checkbox">
+ <label ng-click="toggleLevels(true)">
+ <input type="checkbox" class="invisible" />
+ All
+ </label>
+ </li>
+ <li class="checkbox">
+ <label ng-click="toggleLevels(false)">
+ <input type="checkbox" class="invisible" />
+ None
+ </label>
+ </li>
+ <li role="separator" class="divider"></li>
+ <li class="checkbox" ng-repeat="(level, enabled) in levels">
+ <label class="text-capitalize">
+ <input type="checkbox" ng-model="levels[level]" />
+ {{level}}
+ </label>
+ </li>
+ </ul>
+ </div>
+ <div class="btn-group" filter-dropdown>
+ <button type="button" class="btn btn-default dropdown-toggle">
+ Lint groups <span class="badge">{{selectedValuesCount(groups)}}</span> <span class="caret"></span>
+ </button>
+ <ul class="dropdown-menu">
+ <li class="checkbox">
+ <label ng-click="toggleGroups(true)">
+ <input type="checkbox" class="invisible" />
+ All
+ </label>
+ </li>
+ <li class="checkbox">
+ <label ng-click="toggleGroups(false)">
+ <input type="checkbox" class="invisible" />
+ None
+ </label>
+ </li>
+ <li role="separator" class="divider"></li>
+ <li class="checkbox" ng-repeat="(group, enabled) in groups">
+ <label class="text-capitalize">
+ <input type="checkbox" ng-model="groups[group]" />
+ {{group}}
+ </label>
+ </li>
+ </ul>
+ </div>
+ <div id="version-filter">
+ <div class="btn-group" filter-dropdown>
+ <button type="button" class="btn btn-default dropdown-toggle">
+ Version
+ <span id="version-filter-count" class="badge">
+ {{versionFilterCount(versionFilters)}}
+ </span>
+ <span class="caret"></span>
+ </button>
+ <ul id="version-filter-selector" class="dropdown-menu">
+ <li class="checkbox">
+ <label ng-click="clearVersionFilters()">
+ <input type="checkbox" class="invisible" />
+ Clear filters
+ </label>
+ </li>
+ <li role="separator" class="divider"></li>
+ <li class="checkbox" ng-repeat="(filter, vars) in versionFilters">
+ <label ng-attr-for="filter-{filter}">{{filter}}</label>
+ <span>1.</span>
+ <input type="number"
+ min="29"
+ ng-attr-id="filter-{filter}"
+ class="version-filter-input form-control filter-input"
+ maxlength="2"
+ ng-model="versionFilters[filter].minorVersion"
+ ng-model-options="{debounce: 50}"
+ ng-change="updateVersionFilters()" />
+ <span>.0</span>
+ </li>
+ </ul>
+ </div>
+ </div>
+
+ </div>
+ <div class="col-12 col-md-7 search-control">
+ <div class="input-group">
+ <label class="input-group-addon" id="filter-label" for="search-input">Filter:</label>
+ <input type="text" class="form-control filter-input" placeholder="Keywords or search string" id="search-input" ng-model="search" ng-model-options="{debounce: 50}"/>
+ <span class="input-group-btn">
+ <button class="filter-clear btn" type="button" ng-click="search = ''">
+ Clear
+ </button>
+ </span>
+ </div>
+ </div>
+ </div>
+ </div>
+ <!-- The order of the filters should be from most likely to remove a lint to least likely to improve performance. -->
+ <article class="panel panel-default" id="{{lint.id}}" ng-repeat="lint in data | filter:bySearch | filter:byGroups | filter:byLevels | filter:byVersion">
+ <header class="panel-heading" ng-click="open[lint.id] = !open[lint.id]">
+ <h2 class="panel-title">
+ <div class="panel-title-name">
+ <span>{{lint.id}}</span>
+ <a href="#{{lint.id}}" class="anchor label label-default" ng-click="open[lint.id] = true; $event.stopPropagation()">¶</a>
+ <a href="" id="clipboard-{{lint.id}}" class="anchor label label-default" ng-click="copyToClipboard(lint); $event.stopPropagation()">
+ 📋
+ </a>
+ </div>
+
+ <div class="panel-title-addons">
+ <span class="label label-lint-group label-default label-group-{{lint.group}}">{{lint.group}}</span>
+
+ <span class="label label-lint-level label-lint-level-{{lint.level}}">{{lint.level}}</span>
+
+
+ <span class="label label-doc-folding" ng-show="open[lint.id]">−</span>
+ <span class="label label-doc-folding" ng-hide="open[lint.id]">+</span>
+ </div>
+ </h2>
+ </header>
+
+ <div class="list-group lint-docs" ng-if="open[lint.id]" ng-class="{collapse: true, in: open[lint.id]}">
+ <div class="list-group-item lint-doc-md" ng-bind-html="lint.docs | markdown"></div>
+ <div class="lint-additional-info-container">
+ <!-- Applicability -->
+ <div class="lint-additional-info-item">
+ <span> Applicability: </span>
+ <span class="label label-default label-applicability">{{lint.applicability.applicability}}</span>
+ <a href="https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint_defs/enum.Applicability.html#variants">(?)</a>
+ </div>
+ <!-- Clippy version -->
+ <div class="lint-additional-info-item">
+ <span>{{lint.group == "deprecated" ? "Deprecated" : "Added"}} in: </span>
+ <span class="label label-default label-version">{{lint.version}}</span>
+ </div>
+ <!-- Open related issues -->
+ <div class="lint-additional-info-item">
+ <a href="https://github.com/rust-lang/rust-clippy/issues?q=is%3Aissue+{{lint.id}}">Related Issues</a>
+ </div>
+ <!-- Jump to source -->
+ <div class="lint-additional-info-item">
+ <a href="https://github.com/rust-lang/rust-clippy/blob/{{docVersion}}/clippy_lints/{{lint.id_span.path}}#L{{lint.id_span.line}}">View Source</a>
+ </div>
+ </div>
+ </div>
+ </article>
+ </div>
+ </div>
+
+ <a href="https://github.com/rust-lang/rust-clippy">
+ <img style="position: absolute; top: 0; right: 0; border: 0; clip-path: polygon(0% 0%, 100% 0%, 100% 100%);" src="https://s3.amazonaws.com/github/ribbons/forkme_right_darkblue_121621.png" alt="Fork me on Github"/>
+ </a>
+
+ <script src="https://cdnjs.cloudflare.com/ajax/libs/markdown-it/12.3.2/markdown-it.min.js"></script>
+ <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.5.0/highlight.min.js"></script>
+ <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.5.0/languages/rust.min.js"></script>
+ <script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.4.12/angular.min.js"></script>
+ <script src="script.js"></script>
+</body>
+</html>
projects / rust.git / commitdiff