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
Add test for `try_err` lint within try blocks.
Fixes#5757
Turns out the current `try_err` implementation already skips expressions inside of a try block.
When inside of a try block, `Err(_)?` is desugared to a `break` instead of normal `return` . This makes `find_return_type()` function at [this line](eb4d88e690/clippy_lints/src/matches/try_err.rs (L29)) always returns `None` and skips the check.
I just added a test case for try block.
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
`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
Stabilize const `{integer}::from_str_radix` i.e. `const_int_from_str`
This PR stabilizes the feature `const_int_from_str`.
- ACP Issue: rust-lang/libs-team#74
- Implementation PR: rust-lang/rust#99322
- Part of Tracking Issue: rust-lang/rust#59133
API Change Diff:
```diff
impl {integer} {
- pub fn from_str_radix(src: &str, radix: u32) -> Result<Self, ParseIntError>;
+ pub const fn from_str_radix(src: &str, radix: u32) -> Result<Self, ParseIntError>;
}
impl ParseIntError {
- pub fn kind(&self) -> &IntErrorKind;
+ pub const fn kind(&self) -> &IntErrorKind;
}
```
This makes it easier to parse integers at compile-time, e.g.
the example from the Tracking Issue:
```rust
env!("SOMETHING").parse::<usize>().unwrap()
```
could now be achived with
```rust
match usize::from_str_radix(env!("SOMETHING"), 10) {
Ok(val) => val,
Err(err) => panic!("Invalid value for SOMETHING environment variable."),
}
```
rather than having to depend on a library that implements or manually implement the parsing at compile-time.
---
Checklist based on [Libs Stabilization Guide - When there's const involved](https://std-dev-guide.rust-lang.org/development/stabilization.html#when-theres-const-involved)
I am treating this as a [partial stabilization](https://std-dev-guide.rust-lang.org/development/stabilization.html#partial-stabilizations) as it shares a tracking issue (and is rather small), so directly opening the partial stabilization PR for the subset (feature `const_int_from_str`) being stabilized.
- [x] ping Constant Evaluation WG
- [x] no unsafe involved
- [x] no `#[allow_internal_unstable]`
- [ ] usage of `intrinsic::const_eval_select` rust-lang/rust#124625 in `from_str_radix_assert` to change the error message between compile-time and run-time
- [ ] [rust-labg/libs-api FCP](https://github.com/rust-lang/rust/pull/124941#issuecomment-2207021921)
needless_borrows_for_generic_args: Fix for &mut
This commit fixes a bug introduced in #12706, where the behavior of the lint has been changed, to avoid suggestions that introduce a move. The motivation in the commit message is quite poor (if the detection for significant drops is not sufficient because it's not transitive, the proper fix would be to make it transitive). However, #12454, the linked issue, provides a good reason for the change — if the value being borrowed is bound to a variable, then moving it will only introduce friction into future refactorings.
Thus #12706 changes the logic so that the lint triggers if the value being borrowed is Copy, or is the result of a function call, simplifying the logic to the point where analysing "is this the only use of this value" isn't necessary.
However, said PR also introduces an undocumented carveout, where referents that themselves are mutable references are treated as Copy, to catch some cases that we do want to lint against. However, that is not sound — it's possible to consume a mutable reference by moving it.
To avoid emitting false suggestions, this PR reintroduces the referent_used_exactly_once logic and runs that check for referents that are themselves mutable references.
Thinking about the code shape of &mut x, where x: &mut T, raises the point that while removing the &mut outright won't work, the extra indirection is still undesirable, and perhaps instead we should suggest reborrowing: &mut *x. That, however, is left as possible future work.
Fixes#12856
changelog: none
