Fix handling of `Deref` in `assigning_clones`
The `assigning_clones` lint had a special case for producing a bit nicer code for mutable references:
```rust
fn clone_function_lhs_mut_ref(mut_thing: &mut HasCloneFrom, ref_thing: &HasCloneFrom) {
*mut_thing = Clone::clone(ref_thing);
}
//v
fn clone_function_lhs_mut_ref(mut_thing: &mut HasCloneFrom, ref_thing: &HasCloneFrom) {
Clone::clone_from(mut_thing, ref_thing);
}
```
However, this could [break](https://github.com/rust-lang/rust-clippy/issues/12437) when combined with `Deref`.
This PR removes the special case, so that the generated code should work more generally. Later we can improve the detection of `Deref` and put the special case back in a way that does not break code.
Fixes: https://github.com/rust-lang/rust-clippy/issues/12437
r? `@blyxyas`
changelog: [`assigning_clones`]: change applicability to `Unspecified` and fix a problem with `Deref`.
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
Remove unnecessary `res` field in `for_each_expr` visitors
Small refactor in the `for_each_expr*` visitors. This should not change anything functionally.
Instead of storing the final value `Option<B>` in the visitor and setting it to `Some` when we get a `ControlFlow::Break(B)` from the closure, we can just directly return it from the visitor itself now that visitors support that.
cc #12829 and https://github.com/rust-lang/rust-clippy/pull/12830#discussion_r1627882827
changelog: none
Implement lint against ambiguous negative literals
This PR implements a lint against ambiguous negative literals with a literal and method calls right after it.
## `ambiguous_negative_literals`
(deny-by-default)
The `ambiguous_negative_literals` lint checks for cases that are confusing between a negative literal and a negation that's not part of the literal.
### Example
```rust,compile_fail
-1i32.abs(); // equals -1, while `(-1i32).abs()` equals 1
```
### Explanation
Method calls take precedence over unary precedence. Setting the precedence explicitly makes the code clearer and avoid potential bugs.
<details>
<summary>Old proposed lint</summary>
## `ambiguous_unary_precedence`
(deny-by-default)
The `ambiguous_unary_precedence` lint checks for use the negative unary operator with a literal and method calls.
### Example
```rust
-1i32.abs(); // equals -1, while `(-1i32).abs()` equals 1
```
### Explanation
Unary operations take precedence on binary operations and method calls take precedence over unary precedence. Setting the precedence explicitly makes the code clearer and avoid potential bugs.
</details>
-----
Note: This is a strip down version of https://github.com/rust-lang/rust/pull/117161, without the binary op precedence.
Fixes https://github.com/rust-lang/rust/issues/117155
`@rustbot` labels +I-lang-nominated
cc `@scottmcm`
r? compiler
Changelog for Clippy 1.80 🌞
Roses are red,
Violets are blue,
Summer is fun,
So much sun
---
### The cat of this release is *Maunzer* submitted by `@llogiq:`
<img height=500 src="https://github.com/rust-lang/rust-clippy/assets/4200835/a1da6948-446d-4ccf-95a7-c816a8afdc3f" alt="The cats of this Clippy release" />
Cats for the next release can be nominated in the comments :D
---
changelog: none
I wish everyone reading this a beautiful and happy day =^.^=
Lintcheck: Rework and limit diff output for GH's CI
### Background
While working on https://github.com/rust-lang/rust-clippy/pull/13136 I found an amazing limitation of GH's CI. The summary can at most have be 1MB of text. Here is the warning message:
> $GITHUB_STEP_SUMMARY upload aborted, supports content up to a size of 1024k, got 46731k. For more information see: https://docs.github.com/actions/using-workflows/workflow-commands-for-github-actions#adding-a-markdown-summary
[The PR](https://github.com/rust-lang/rust-clippy/pull/13136) produced a *casual* 61808 changes. Guess that's why those lints are not *warn-by-default* :P.
### Changes:
This PR limits the lintcheck diff output in two ways.
1. The diff is limited to 200 messages per lint per section. Hidden messages are indicated by a message at the end of the section.
2. The output is first written to a file and only the first 1MB is written to ` >> $GITHUB_STEP_SUMMARY`. The entire file is also written to the normal CI log. This helps for cases where several lints change and the total size exceeds the 1MB limit.
An example of these changes can be seen here: https://github.com/xFrednet/rust-clippy/actions/runs/10028799118?pr=4
---
changelog: none
r? `@Alexendoo`
Sorry for bombarding you with so many PR's lately 😅 Feel free to pass some of you reviews to me.
Use ControlFlow in more places
Now, instead of manually using variables in visitors to signify that a visit is "done" and that the visitor should stop traversing. We use the trait type "Result" to signify this (in relevant places).
I'll schedule a perf run, I don't think it will be much of a difference, but every bit of performance is welcomed :)
changelog: Improve performance, less memory use in visitors
Fixes#12829
r? `@y21`
Make ast `MutVisitor` have the same method name and style as `Visitor`
It doesn't map 100% because some `MutVisitor` methods can filter or even expand to multiple items, but consistency seems nicer.
tracking issue: https://github.com/rust-lang/rust/issues/127615
Fix running compile-test under cargo nextest
`ui_test` itself has `cargo nextest` support which we now use - https://github.com/oli-obk/ui_test/pull/161
It prints `ui_test` as its test name whereas we printed `compile_test`, this ended up being treated as a test name filter causing all the tests to be filtered out
changelog: none
Temporarily remove myself from reviewer rotation
I'm going to focus on the project goal and my own contributions, this + medical stuff leaves me not enough time to review.
I'll still review any performance related PR, and you can still request from me a benchmark for a PR, and will finish the PRs that I'm still assign to.
changelog: none
Misc refactorings
Various small re-orderings to check the HIR tree or AST before doing other checks. Also includes a small bug fix for `arc_with_small_send_sync` not actually checking for `Arc::new`.
changelog: none
