Changelog for Clippy 1.81 🔰
Roses are red,
Violets are blue,
Expectations are stable,
And reasons are set
---
### The cat of this release is *Keepy* submitted by `@blyxyas:`
<img height=500 src="https://github.com/rust-lang/rust-clippy/assets/73757586/902dd802-5ac8-471e-bb93-e195526ba580" alt="The cats of this Clippy release" />
Cats for the next release can be nominated in the comments :D
---
changelog: none
move `manual_c_str_literals` to complexity
IMO the suggestion to use `c""` literals over a hardcoded `\0` byte string literal has some fairly strong upsides (no need to manually null-terminate it and the compiler checks for intermediary null bytes) that this should just be enabled by default.
It's also written slightly conservatively to only emit a warning when we can be reasonably confident that the lint is *actually* applicable (that is, lint on e.g. `b"foo\0".as_ptr()` but not `b"foo\0"`. The latter looks like a c-string but its type is `&[u8; _]`, and if it's used in a context where a byte slice is needed then you have no nice way to convert to it from a `c"foo"` literal of type `&CStr`).
changelog: move [`manual_c_str_literals`] to complexity (now warn-by-default)
Extend `implicit_saturating_sub` lint
Fixes#10070.
It can serve as base if we want to add equivalent checks for other arithmetic operations.
Also one important note: when writing this lint, I realized that I could check for wrong conditions performed beforehand on subtraction and added another part in the lint. Considering they both rely on the same checks, I kept both in the same place. Not sure if it makes sense though...
changelog: Extend `implicit_saturating_sub` lint
Use `is_diagnostic_item` for checking a def_id in `unnecessary_min_or_max`.
close#13191
This PR fixes the false positives in `unnecessary_min_or_max `.
We should use `is_diagnostic_item` for checking def_ids in this lint.
----
changelog: fix false positive in `unnecessary_min_or_max `.
Add new lint: `used_underscore_items`
Closes#13260
---
changelog: new [`used_underscore_items`] lint against using items with a single leading underscore
Fix manual_range_patterns case with one element at OR
Close#11825
As mentioned #11825 `OR` can be used for stylistic purposes with one element, we can filter this case from triggering lint
changelog: [`manual_range_patterns`]: not trigger when `OR` has only one element
check std::panic::panic_any in panic lint
close#13292
This PR detects `std::panic::panic_any` in panic lint.
changelog: check std::panic::panic_any in panic lint
Rewrite `empty_line_after_doc_comments` and `empty_line_after_outer_attr`, move them from `nursery` to `suspicious`
changelog: [`empty_line_after_doc_comments`], [`empty_line_after_outer_attr`]: rewrite and move them from `nursery` to `suspicious`
They now lint when there's a comment between the last attr/doc comment and the empty line, to cover the case:
```rust
/// Docs for `old_code
// fn old_code() {}
fn new_code() {}
```
When these lints or `suspicious_doc_comments` trigger we no longer trigger any other doc lint as a broad fix for #12917, reverts some of #13002 as the empty line lints cover it
I ended up not doing https://github.com/rust-lang/rust-clippy/issues/12917#issuecomment-2161828859 as I don't think it's needed
Ignore underscore-prefixed args for needless_pass_by_value lint
When a user explicitly tags a param as unused (yet?), there is no need to raise another lint on it.
fixes#7295
Note that I had to rename all `_*` params in the tests, but kept the variable name length to avoid extra changes in the expected output.
changelog: [`needless_pass_by_value`]: do not warn if the argument name starts with an `_`
Diverging subexpression lint should not fire on todo!()
As per #10243 it is not that helpful to point out that a subexpression diverges, so do not fire on todo
changelog: [`diverging_sub_expression`]: do not trigger on todo
Fix confusing message in double_must_use lint
Close#13003
As mentioned at #13003 it isn't quite clear what it means "an empty `#[must_use]` attribute" so clarify it
changelog: [none]
Trigger [`string_slice`] if expression is reference to `&str`
Close#12708
changelog: [`string_slice`]: trigger lint if expression is reference to `&str`
fix false positive in explicit_iter_loop with msrv
close#13184
This PR fix false positive in explicit_iter_loop when msrv < 1.80
changelog: fix false positive in explicit_iter_loop when msrv < 1.80
Remove `find_format_arg_expr` AST fallback
If the function fails where it shouldn't we can fix that directly, but the fallback path is untested as I'm not aware of a case where it would fail
changelog: none
Disable assigning_clones for tests
Close: #12752
As mentioned at #12752 when a test struct is initialized with some default string, this inverts the order of assignee/assignment and makes a bit harder to read/write code
changelog: [`assigning_clones.rs`]: disable assigning_clones for tests
Clarify suggestion message for unwrap lint
Close#10217
As mentioned at #10217 message for `unwrap` uses `..` like `Some(..)` which can confuse with slice and other places mostly use `<item>` like `for (i, <item>) in target_groups_json.iter().enumerate().skip(1) {` So replace `..` to `<item>`
changelog: [`unnecessary_unwrap`] clarify suggestion message
fix code blocks in doc comments inconsistently using 3 or 4 spaces of indentation
The metadata collector script was treating the space lines all start with as indentation. This caused code block's triple backticks to get a space in front of it, like this:
```
```rust
^ this space
```
Code after that that is indented with 4 spaces will only have 3 of those rendered.
Example (taken from [here](https://rust-lang.github.io/rust-clippy/master/index.html#/missing_panics_doc)):
```rust
...
pub fn divide_by(x: i32, y: i32) -> i32 {
if y == 0 { // 3 spaces
panic!("Cannot divide by 0") // 7 spaces
...
```
Also added 'compile_fail' alongside the other rustdoc directives (second code block [here](https://rust-lang.github.io/rust-clippy/master/index.html#/macro_metavars_in_unsafe) had no highlighting), fixed a doc comment using 'rs' instead of 'rust' and removed some spaces causing an extra missing space of indentation (see second code block [here](https://rust-lang.github.io/rust-clippy/master/index.html#/map_err_ignore)).
changelog: none
Replace `rustc_semver` with `rustc_session::RustcVersion`
Allows dropping a dependency but there is a behaviour change here, the following versions are no longer accepted:
* `1` (would need to be `1.0` or `1.0.0`)
* `1.0.0-alpha`
* `1.0.0-alpha.2`
* `1.0.0-beta`
But this seems unlikely to effect anybody, I did some GitHub searching and found no occurrences outside our UI tests
r? `@flip1995`
changelog: none
Fix case where doc_markdown is triggered on words ending with "ified"
Fixes#13097.
r? `@Alexendoo`
changelog: Fix case where doc_markdown is triggered on words ending with "ified"
[`macro_metavars_in_unsafe`]: recognize metavariables in tail expressions
Fixes#13219
`macro_metavars_in_unsafe` keeps track of the current "expansion depth" (incremented/decremented when entering/leaving a macro span) to tell if an expression from the root context is contained within a macro (see the doc comment I added for a hopefully better explanation)
Before this PR, we didn't increment said `expn_depth` for `unsafe` blocks within macros, because we already do that in `visit_stmt` anyway, so it would work fine for statements, but that's not enough for tail expressions of an unsafe block.
So we now also increment it for macro unsafe blocks.
Also updated the comment for `expn_depth` while I'm at it because "This is not necessary for correctness" isn't correct now that I think about it
------
changelog: none
Respect allow `inconsistent_struct_constructor` on the struct definition
Closes#13203
Now we check if the target type is marked with `#[allow(clippy:inconsistent_struct_constructor)]` before lining.
As a side-effect of this change, The rule in the subject no longer runs on non-local `AdtDef`s. However, as suggested by `@Jarcho` it shouldn't be a big deal since most of the time we didn't have access to this information anyway.
> You can't get lint attributes from other crates. I would probably just restrict the lint to only work with types from the current crate while you're at it. Upstream crates don't have a definition order from the point of view of the current crate (with the exception of #[repr(C)] structs).
changelog: Respect allow `inconsistent_struct_constructor` on the struct definition.
By splitting the `FnSig` within `TyKind::FnPtr` into `FnSigTys` and
`FnHeader`, which can be packed more efficiently. This reduces the size
of the hot `TyKind` type from 32 bytes to 24 bytes on 64-bit platforms.
This reduces peak memory usage by a few percent on some benchmarks. It
also reduces cache misses and page faults similarly, though this doesn't
translate to clear cycles or wall-time improvements on CI.
Don't use `LateContext` in the constant evaluator
This also changes the interface to require explicitly creating the context. `constant` could be added back in, but the others are probably not worth it.
A couple of bugs have been fixed. The wrong `TypeckResults` was used once when evaluating a constant, and the wrong `ParamEnv` was used by some callers (there wasn't a way to use the correct one).
changelog: none
Add lint for `unused_result_ok`
This PR adds a lint to capture the use of `expr.ok();` when the result is not _really_ used.
This could be interpreted as the result being checked (like it is with `unwrap()` or `expect`) but
it actually only ignores the result.
`let _ = expr;` expresses that intent better.
This was also mentionned in #8994 (although not being the main topic of that issue).
changelog: [`misleading_use_of_ok`]: Add new lint to capture `.ok();` when the result is not _really_ used.
Remove `multispan_sugg[_with_applicability]`
They're thin wrappers over the corresponding diag method so we should just use that instead
changelog: none
Fix [`redundant_slicing`] when the slice is behind a mutable reference
Fixes#12751
changelog: Fix [`redundant_slicing`] when the slice is behind a mutable reference and a immutable reference is expected.
When a suggestion part is for already present code, do not highlight it. If after that there are no highlights left, do not show the suggestion at all.
Fix clippy lint suggestion incorrectly treated as `span_help`.
Fix `redundant_closure` false positive with closures has return type contains `'static`
Fix#13073 .
Please enable "ignore white-space change" settings in github UI for easy reviewing.
HACK: The third commit contains a hack to check if a type `T: 'static` when `fn() -> U where U: 'static`.
I don't have a clean way to check for it.
changelog: [`redundant_closure`] Fix false positive with closures has return type contains `'static`
Fix false positive for `missing_backticks` in footnote references
Fixes#13183.
changelog: Fix false positive for `missing_backticks` in footnote references
Emit `if_let_mutex` in presence of other mutexes
Currently (master, not nightly nor stable) `if_let_mutex` does not emit a warning here:
```rs
let m1 = Mutex::new(10);
let m2 = Mutex::new(());
if let 100..=200 = *m1.lock().unwrap() {
m2.lock();
} else {
m1.lock();
}
```
It currently looks for the first call to `.lock()` on *any* mutex receiver inside of the if/else body, and only later (outside of the visitor) checks that the receiver matches the mutex in the scrutinee. That means that in cases like the above, it finds the `m2.lock()` expression, stops the visitor, fails the check that it's the same mutex (`m2` != `m1`) and then does not look for any other `.lock()` calls.
So, just make the receiver check also part of the visitor so that we only stop the visitor when we also find the right receiver.
The first commit has the actual changes described here. The sceond one just unnests all the `if let`s
----
changelog: none
Misc changes to `clippy_config`
Contains part of #13084
Changes include:
* Sort config list and each configs lint list.
* Add default text for the two configs that were missing it.
* Switch the lint list in the configs to an attribute.
* Make `dev fmt` sort the config list.
r? `@xFrednet`
changelog: none
`missing_trait_methods`: lint methods in definition order
Lintcheck for #13157 showed a bunch of changes for `missing_trait_methods`
This is because `values_sorted` was sorting the entries by the key's [`DefPathHash`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/def_id/struct.DefPathHash.html), this is stable for a given compiler but can change across versions
changelog: none
Fix while_let_on_iterator dropping loop label when applying fix.
Loop label was not persisted when displaying help and was therefore producing broken rust code when applying fixes.
Solution was to store the `ast::Label` when creating a `higher::WhileLet` from an expression and add the label name to the lint suggestion and diagnostics.
---
Fixes: https://github.com/rust-lang/rust-clippy/issues/13123
changelog: [`while_let_on_iterator`]: Fix issue dropping loop label when displaying help and applying fixes.
Add `BTreeSet` detection to the `set_contains_or_insert` lint
* Detect `BTreeSet::contains` + `BTreeSet::insert` usage in the same way as with the `HashSet`.
CC: `@lochetti` `@bitfield`
----
changelog: [`set_contains_or_insert`]: Handle `BTreeSet` in addition to `HashSet`
Make `std_instead_of_core` somewhat MSRV aware
For #13158, this catches some things e.g. `core::net` and the recently stable `core::error` but not things moved individually like `UnwindSafe`, as far as I can see the version for those isn't easily available
Beta nominating since ideally we'd get this change in the same version as `core::error` becomes stable
cc `@kpreid`
changelog: none
Support ?Trait bounds in supertraits and dyn Trait under a feature gate
This patch allows `maybe` polarity bounds under a feature gate. The only language change here is that corresponding hard errors are replaced by feature gates. Example:
```rust
#![feature(allow_maybe_polarity)]
...
trait Trait1 : ?Trait { ... } // ok
fn foo(_: Box<(dyn Trait2 + ?Trait)>) {} // ok
fn bar<T: ?Sized + ?Trait>(_: &T) {} // ok
```
Maybe bounds still don't do anything (except for `Sized` trait), however this patch will allow us to [experiment with default auto traits](https://github.com/rust-lang/rust/pull/120706#issuecomment-1934006762).
This is a part of the [MCP: Low level components for async drop](https://github.com/rust-lang/compiler-team/issues/727)
Avoid ref when using format!
Clean up a few minor refs in `format!` macro, as it has a performance cost. Apparently the compiler is unable to inline `format!("{}", &variable)`, and does a run-time double-reference instead (format macro already does one level referencing).
Inlining format args prevents accidental `&` misuse.
See also https://github.com/rust-lang/rust/issues/112156
changelog: none