Verify Borrow<T> semantics for types that implement Hash, Borrow<str> and Borrow<[u8]>.
Fixes#11710
The essence of the issue is that types that implement Borrow<T> provide a facet or a representation of the underlying type. Under these semantics `hash(a) == hash(a.borrow())`.
This is a problem when a type implements `Borrow<str>`, `Borrow<[u8]>` and Hash, it is expected that the hash of all three types is identical. The problem is that the hash of [u8] is not the same as that of a String, even when the byte reference ([u8]) is derived from `.as_bytes()`
- [x] Followed [lint naming conventions][lint_naming]
- [x] Added passing UI tests (including committed `.stderr` file)
- [x] `cargo test` passes locally
- [x] Executed `cargo dev update_lints`
- [x] Added lint documentation
- [x] Run `cargo dev fmt`
---
- [x] Explanation of the issue in the code
- [x] Tests reproducing the issue
- [x] Lint rule and emission
---
changelog: New lint: [`impl_hash_borrow_with_str_and_bytes`]
[#11781](https://github.com/rust-lang/rust-clippy/pull/11781)
Implements a lint to prevent implementation of Hash, Borrow<str> and
Borrow<[u8]> as it breaks Borrow<T> "semantics". According to the book,
types that implement Borrow<A> and Borrow<B> must ensure equality of
borrow results under Eq,Ord and Hash.
> In particular Eq, Ord and Hash must be equivalent for borrowed and
owned values: x.borrow() == y.borrow() should give the same result as x == y.
In the same way, hash(x) == hash(x as Borrow<[u8]>) != hash(x as Borrow<str>).
changelog: newlint [`impl_hash_with_borrow_str_and_bytes`]
Fix typos in recent lint documentation.
Fixes typos and markup errors, and also makes the examples more realistic by hiding the `;`s so as not to visibly be discarding the computed value. Affected lints:
* `redundant_as_str`
* `unnecessary_map_on_constructor`
changelog: none
clippy::suboptimal_flops used to not check if the second parameter to f32/f64.mul_add() was float. Since the method is
only defined to take `Self` as paremters, the suggestion was wrong.
Fixes#11831
teach `eager_or_lazy` about panicky arithmetic operations
Fixes#9422Fixes#9814Fixes#11793
It's a bit sad that we have to do this because arithmetic operations seemed to me like the prime example where a closure would not be necessary, but this has "side effects" (changes behavior when going from lazy to eager) as some of these panic on overflow/underflow if compiled with `-Coverflow-checks` (which is the default in debug mode).
Given the number of backlinks in the mentioned issues, this seems to be a FP that is worth fixing, probably.
changelog: [`unnecessary_lazy_evaluations`]: don't lint if closure has panicky arithmetic operations
Extend `maybe_misused_cfg` lint over `cfg(test)`
Fixes#11240.
One thought I had is that we could use the levenshtein distance (of 1) to ensure this is indeed `test` that was targeted. But maybe it's overkill, not sure.
changelog: [`maybe_misused_cfg`]: Extend lint over `cfg(test)`
r? `@blyxyas`
This was made possible by the removal of plugin support, which
simplified lint store creation.
This simplifies the places in rustc and rustdoc that call
`describe_lints`, which are early on. The lint store is now built before
those places, so they don't have to create their own lint store for
temporary use, they can just use the main one.
Changelog for Rust 1.74 🎃
Roses are red,
Halloween is over,
Have you considered,
Buying a Mars rover?
---
### The cats of this release:
<img height=500 src="https://github.com/rust-lang/rust-clippy/assets/17087237/095bd32e-b5e3-41db-8f0f-bdef7ca1a6d0" alt="The cats of this Clippy release" />
<sub>The cat for the next release can be nominated in the comments</sub>
---
changelog: none
Change `if_same_then_else` to be a `style` lint
CC #3770
From https://github.com/rust-lang/rust-clippy/issues/3770#issuecomment-687565594 (`@flip1995):`
> Oh I thought I replied to this: I definitely see now that having this
> as a correctness lint might be the wrong categorization. What we might
> want to do is to just allow this lint, if there are comments in the
> arm bodies. But a good first step would be to downgrade this lint to
> style or complexity. I would vote for style since merging two arms is
> not always less complex.
changelog: [`if_same_then_else`]: Change to be a `style` lint
disallow calls to `LintContext::struct_span_lint` and `TyCtxt::struct_span_lint_hir`
`LintContext::struct_span_lint` and `TyCtxt::struct_span_lint_hir` don't show the link to the clippy documentation, see: #11805
In #11810, the last few calls to those methods were replaced with `span_lint_*`. It seems like we should just disallow them altogether so that no new code tries to use them.
The existing `disallowed_methods` lint makes this easy.
changelog: none
[`impl_trait_in_params`]: avoid ICE when function with `impl Trait` type has no parameters
Fixes#11803
If I'm reading the old code correctly, it was taking the span of the first parameter (without checking that it exists, which caused the ICE) and uses that to figure out where the generic parameter to insert should go (cc `@blyxyas` you wrote the lint, is that correct?).
This seemed equivalent to just `generics.span`, which doesn't require calculating the spans like that and simplifies it a fair bit
changelog: don't ICE when function has no parameters but generics have an `impl Trait` type
add help text where missing to lints
Fixes https://github.com/rust-lang/rust-clippy/issues/11805
Essentially just changes the section of code that applies the lint from using `cx.struct_span_lint` and instead opts for `span_lint_and_then`, which automatically appends the help text.
changelog: add missing help text for `cast_possible_wrap`, `mod_module_files`, and `self_named_module_files` lints
CC #3770
From https://github.com/rust-lang/rust-clippy/issues/3770#issuecomment-687565594 (@flip1995):
> Oh I thought I replied to this: I definitely see now that having this
> as a correctness lint might be the wrong categorization. What we might
> want to do is to just allow this lint, if there are comments in the
> arm bodies. But a good first step would be to downgrade this lint to
> style or complexity. I would vote for style since merging two arms is
> not always less complex.
