bors [Mon, 9 Nov 2020 19:13:26 +0000 (19:13 +0000)]
Auto merge of #6305 - smoelius:master, r=flip1995
Add `let_underscore_drop`
This line generalizes `let_underscore_lock` (#5101) to warn about any initializer expression that implements `Drop`.
So, for example, the following would generate a warning:
```rust
struct Droppable;
impl Drop for Droppable {
fn drop(&mut self) {}
}
let _ = Droppable;
```
I tried to preserve the original `let_underscore_lock` functionality in the sense that the warning generated for
```rust
let _ = mutex.lock();
```
should be unchanged.
*Please keep the line below*
changelog: Add lint [`let_underscore_drop`]
Dylan DPC [Mon, 9 Nov 2020 18:06:55 +0000 (19:06 +0100)]
Rollup merge of #78710 - petrochenkov:macvisit, r=davidtwco
rustc_ast: Do not panic by default when visiting macro calls
Panicking by default made sense when we didn't have HIR or MIR and everything worked on AST, but now all AST visitors run early and majority of them have to deal with macro calls, often by ignoring them.
The second commit renames `visit_mac` to `visit_mac_call`, the corresponding structures were renamed earlier in https://github.com/rust-lang/rust/pull/69589.
bors [Sun, 8 Nov 2020 14:24:58 +0000 (14:24 +0000)]
Auto merge of #6293 - Urcra:lint-example-fix, r=flip1995
Fix example used in cargo_common_metadata
The previous example used in `cargo_common_metadata` included an authors field, even though the comment says it doesn't. And thus doesn't actually demonstrate an example of how the lint fails.
This removes that authors field from the _bad_ example and suggest to fix the _bad_ example by adding the authors field
changelog: Fix example used in `cargo_common_metadata`
bors [Sun, 8 Nov 2020 11:41:22 +0000 (11:41 +0000)]
Auto merge of #6205 - josephlr:empty-loop2, r=flip1995
Enable empty_loop lint for no_std crates
Depends on #6162. Fixes #6161
We skip the lint if the `loop {}` is in the `#[panic_handler]` as the
main recommendation we give is to panic, which obviously isn't
possible in a panic handler.
changelog: Enable empty_loop lint for no_std crates
Joe Richey [Fri, 23 Oct 2020 06:39:25 +0000 (23:39 -0700)]
Enable empty_loop lint for no_std crates
We skip the lint if the `loop {}` is in the `#[panic_handler]` as the
main recommendation we give is to panic, which obviously isn't
possible in a panic handler.
bors [Sat, 7 Nov 2020 15:51:13 +0000 (15:51 +0000)]
Auto merge of #6110 - rail-rain:care_enums_non_copy_const, r=llogiq
"Respect" enums in `interior_mutable_const`
fixes #3962
fixes #3825
Hello,
It might not be a good idea to submit another relatively large PR while I have an opened PR; but, I've finished this anyway. This may be able to wait for months.
Note: the code uses the MIR interpreter, which the author of #3962 thought unlikely to be a solution. This might be over-engineering; but, I think it's important to be able to work with the 'http' crate (#3825). (And, I don't want to write a MIR visitor)
---
changelog: fix a false positive in two `interior_mutable_const` lints where a constant with enums gets linted
even if it uses a clearly unfrozen variant
bors [Wed, 4 Nov 2020 22:45:15 +0000 (22:45 +0000)]
Auto merge of #78662 - sexxi-goose:add_expr_id_to_delegate, r=nikomatsakis
Provide diagnostic suggestion in ExprUseVisitor Delegate
The [Delegate trait](https://github.com/rust-lang/rust/blob/981346fc07dd5ef414c5b1b21999f7604cece006/compiler/rustc_typeck/src/expr_use_visitor.rs#L28-L38) currently use `PlaceWithHirId` which is composed of Hir `Place` and the
corresponding expression id.
Even though this is an accurate way of expressing how a Place is used,
it can cause confusion during diagnostics.
Eg:
```
let arr : [String; 5];
let [a, ...] = arr;
^^^ E1 ^^^ = ^^E2^^
```
Here `arr` is moved because of the binding created E1. However, when we
point to E1 in diagnostics with the message `arr` was moved, it can be
confusing. Rather we would like to report E2 to the user.
bors [Wed, 4 Nov 2020 22:21:44 +0000 (22:21 +0000)]
Auto merge of #5911 - hegza:issue-568, r=ebroto
Add lint for 'field_reassign_with_default` #568
changelog: Add lint for field_reassign_with_default that checks if mutable object + field modification is used to edit a binding initialized with Default::default() instead of struct constructor.
Fixes #568
Notes:
- Checks for reassignment of one or more fields of a binding initialized with Default::default().
- Implemented using EarlyLintPass, might be future proofed better with LateLintPass.
- Does not trigger if Default::default() is used via another type implementing Default.
- This is a re-open of [PR#4761](https://github.com/rust-lang/rust-clippy/pull/4761), but I couldn't figure out how to re-open that one so here's a new one with the requested changes :S
bors [Wed, 4 Nov 2020 09:22:54 +0000 (09:22 +0000)]
Auto merge of #6284 - camsteffen:rustc-sym, r=flip1995
Use const sym where possible
I ran a regex search and replace to use const `sym` values where possible. This should give some performance boost by avoiding string interning at runtime.
Con: It is not as consistent as always using `sym!`.
I also changed an internal lint to suggest using `sym::{}`, making an assumption that this will always work for diagnostic items.
Disable and enable when not specifically explained were not clear to me
as an English language speaker, but I was able to figure it out fairly
easily due to the examples having A/W, which I assumed meant `allow` and
`warn`. I removed both words to be sure it was clear as well as
extending the note on what deny means. It now includes a statement on
exactly what each word means.
bors [Tue, 3 Nov 2020 16:21:51 +0000 (16:21 +0000)]
Auto merge of #6165 - dvermd:ref_option_ref, r=flip1995
Add lint 'ref_option_ref' #1377
This lint checks for usage of `&Option<&T>` which can be simplified as `Option<&T>` as suggested in #1377.
This WIP PR is here to get feedback on the lint as there's more cases to be handled:
* statics/consts,
* associated types,
* type alias,
* function/method parameter/return,
* ADT definitions (struct/tuple struct fields, enum variants)
bors [Tue, 3 Nov 2020 15:59:16 +0000 (15:59 +0000)]
Auto merge of #6101 - pitiK3U:from_iter_instead_of_collect, r=flip1995
Add lint: from_iter_instead_of_collect
Fixes #5679
This implements lint for `::from_iter()` from #5679 not the general issue (`std::ops::Add::add`, etc.).
This lint checks if expression is function call with `from_iter` name and if it's implementation of the `std::iter::FromIterator` trait.
Dhruv Jauhar [Sun, 1 Nov 2020 07:15:22 +0000 (02:15 -0500)]
Provide diagnostic suggestion in ExprUseVisitor Delegate
The [Delegate
trait](https://github.com/rust-lang/rust/blob/981346fc07dd5ef414c5b1b21999f7604cece006/compiler/rustc_typeck/src/expr_use_visitor.rs#L28-L38)
currently use `PlaceWithHirId` which is composed of Hir `Place` and the
corresponding expression id.
Even though this is an accurate way of expressing how a Place is used,
it can cause confusion during diagnostics.
Eg:
```
let arr : [String; 5];
let [a, ...] = arr;
^^^ E1 ^^^ = ^^E2^^
```
Here `arr` is moved because of the binding created E1. However, when we
point to E1 in diagnostics with the message `arr` was moved, it can be
confusing. Rather we would like to report E2 to the user.
bors [Sun, 1 Nov 2020 16:52:28 +0000 (16:52 +0000)]
Auto merge of #75534 - Aaron1011:feature/new-future-breakage, r=pnkfelix
Implement rustc side of report-future-incompat
cc https://github.com/rust-lang/rust/issues/71249
This is an alternative to `@pnkfelix's` initial implementation in https://github.com/pnkfelix/rust/commits/prototype-rustc-side-of-report-future-incompat (mainly because I started working before seeing that branch :smile: ).
My approach outputs the entire original `Diagnostic`, in a way that is compatible with incremental compilation. This is not yet integrated with compiletest, but can be used manually by passing `-Z emit-future-incompat-report` to `rustc`.
Several changes are made to support this feature:
* The `librustc_session/lint` module is moved to a new crate `librustc_lint_defs` (name bikesheddable). This allows accessing lint definitions from `librustc_errors`.
* The `Lint` struct is extended with an `Option<FutureBreakage>`. When present, it indicates that we should display a lint in the future-compat report. `FutureBreakage` contains additional information that we may want to display in the report (currently, a `date` field indicating when the crate will stop compiling).
* A new variant `rustc_error::Level::Allow` is added. This is used when constructing a diagnostic for a future-breakage lint that is marked as allowed (via `#[allow]` or `--cap-lints`). This allows us to capture any future-breakage diagnostics in one place, while still discarding them before they are passed to the `Emitter`.
* `DiagnosticId::Lint` is extended with a `has_future_breakage` field, indicating whether or not the `Lint` has future breakage information (and should therefore show up in the report).
* `Session` is given access to the `LintStore` via a new `SessionLintStore` trait (since `librustc_session` cannot directly reference `LintStore` without a cyclic dependency). We use this to turn a string `DiagnosticId::Lint` back into a `Lint`, to retrieve the `FutureBreakage` data.
Currently, `FutureBreakage.date` is always set to `None`. However, this could potentially be interpreted by Cargo in the future.
I've enabled the future-breakage report for the `ARRAY_INTO_ITER` lint, which can be used to test out this PR. The intent is to use the field to allow Cargo to determine the date of future breakage (as described in [RFC 2834](https://github.com/rust-lang/rfcs/blob/master/text/2834-cargo-report-future-incompat.md)) without needing to parse the diagnostic itself.
Henri Lunnikivi [Thu, 31 Oct 2019 16:02:02 +0000 (18:02 +0200)]
Implement field_reassign_with_default
- Implement `field_reassign_with_default` as a `LateLintPass`
- Avoid triggering `default_trait_access` on a span already linted by
`field_reassigned_with_default`
- Merge `default_trait_access` and `field_reassign_with_default` into
`Default`
- Co-authored-by: Eduardo Broto <ebroto@tutanota.com>
- Fixes #568