When I first tried contributing to clippy,
I encountered the problem that a lot of lint suggestions overlapped
with existing lints, so I would spend a bunch of time implementing
something only to figure out it wasn't actually needed.
The "comparison with existing lints" field should hopefully reduce
this somewhat, while not incresing the burden of
requesting a new lint too much due to not being mandatory.
Fix false positive in `useless_attribute` with `redundant_imports`
Add `redundant_imports` to the list of allowed lints on use items to
prevent
`useless_attribute` from triggering false positives when
`#[expect(redundant_imports)]`
or similar attributes are used on use statements.
fixesrust-lang/rust-clippy#15316
---
changelog: [`useless_attribute`]: fix false positive when using
`#[expect(redundant_imports)]` and similar lint attributes on `use`
statements
The useless_attribute lint was incorrectly flagging #[expect(redundant_imports)]
as useless when applied to macro re-exports. This occurred because the lint
didn't recognize 'redundant_imports' as a valid rustc lint name.
This commit:
- Adds 'redundant_imports' to the list of known rustc lints in sym.rs
- Updates the useless_attribute lint to properly handle this case
- Adds a regression test to prevent future false positives
Fixesrust-lang/rust-clippy#15192 by adding checks for no_std while
giving out Box recommendation
```
changelog: [`large_enum_variant`]: Dont suggest `Box` in `no_std` mode
```
- Updated the `help:` text to include a more general suggestion
- Ensures compatibility with `#[no_std]` environments where boxing is
still possible via `alloc`.
Closesrust-lang/rust-clippy#15007
Removes the `break` stmt and the dead code after it when appropriate.
changelog: [`never_loop`] Make sure to remove `break` in suggestions
This makes `const` contexts use the `const`-stability version
information instead of the regular stability one, as `const`-stability
may happen much later than stability in non-`const` contexts.
~~It includes the content of PR rust-lang/rust-clippy#15296 as its first
commit. I separated them because this one is more complex, and
rust-lang/rust-clippy#15296 may be merged more rapidly.~~
changelog: [`incompatible_msrv`]: check the right MSRV when in a `const`
context
r? Jarcho @rustbot label +C-bug +I-false-negative
This makes `const` contexts use the `const`-stability version information
instead of the regular stability one, as `const`-stability may happen
much later than stability in non-`const` contexts.
For example, the `Duration` type from the standard library was only
introduced in Rust 1.3.0.
changelog: [`incompatible_msrv`]: recognize types exceeding MSRV as well
r? Jarcho @rustbot label +C-bug +I-false-negative
This PR supersedes #14328 following the [2025-03-18 Clippy meeting
discussion](https://rust-lang.zulipchat.com/#narrow/channel/257328-clippy/topic/Meeting.202025-03-18/with/506527762).
It uses a simpler approach than what was proposed initially in #14328
and does not add new options.
First, it documents how `cfg_attr` can be used to change the MSRV
considered by Clippy to trigger the lint. This allows the MSRV to be
feature gated, or to be raised in tests.
Also, the lint stops warning about items which have been explicitly
allowed through a rustc feature. This works even if the feature has been
stabilized since. It allows using an older compiler with some features
turned on, as is done in Rust for Linux. This fixes#14425.
Then, if the lint triggers, and it looks like the code is located below
a `cfg` or `cfg_attr` attribute, an additional note is issued, once, to
indicate that the `clippy::msrv` attribute can be controlled by an
attribute.
Finally, the lint is extended to cover any path, not just method and
function calls. For example, enumeration variants, or constants, were
not MSRV checked. This required replacing two `u32::MAX` by
`u32::max_value()` in MSRV-limited tests.
An extra commit adds a TODO for checking the const stability also, as
this is not done right now.
@Centri3 I'll assign this to you because you were assigned #14328 and
you were the one who nominated the issue for discussion (thanks!), but
of course feel free to reroll!
r? @Centri3
changelog: [`incompatible_msrv`]: better documentation, honor the
`features` attribute, and lint non-function entities as well
To avoid false positives, the `range_plus_one` and `range_minus_one`
lints will restrict themselves to situations where the iterator types
can be easily switched from exclusive to inclusive or vice-versa. This
includes situations where the range is used as an iterator, or is used
for indexing.
On the other hand, assignments of the range to variables, including
automatically typed ones or wildcards, will no longer trigger the lint.
However, the cases where such an assignment would benefit from the lint
are probably rare.
In a second commit, the `range_plus_one` and `range_minus_one` logic are
unified, in order to properly emit parentheses around the suggestion
when needed.
Fixrust-lang/rust-clippy#3307Fixrust-lang/rust-clippy#9908
changelog: [`range_plus_one`, `range_minus_one`]: restrict lint to cases
where it is safe to switch the range type
*Edit:* as a consequence, this led to the removal of three
`#[expect(clippy::range_plus_one)]` in the Clippy sources to avoid those
false positives.
No longer suggests `&[i32]` or `&mut [i32]` instead of `&Vec<i32>` or
`&mut Vec<i32>` (also: `Path` and `PathBuf`, etc.) for the parameter
type when the parameter name starts with an underscore (or, if that does
not start with one, then a local `let` binding in the function body,
pointing to the same value, does) – (Fixesrust-lang/rust-clippy#13489,
fixesrust-lang/rust-clippy#13728)
~changelog: fix false positive: [`ptr_arg`] no longer triggers with
underscore binding to `&mut` argument~
changelog: fix false positive: [`ptr_arg`] no longer triggers with
underscore binding to `&T` or `&mut T` argument
*Edit:* This change has been extended to all references, not just
mutable ones. See [discussion below](#issuecomment-3006386877).
In Rust 1.88, the `pin!()` macro uses `unsafe` and triggers
`unsafe_derive_deserialize`.
Fixesrust-lang/rust-clippy#15120
changelog: [`unsafe_derive_deserialize`]: do not trigger because of the
standard library's `pin!()` macro
Fixesrust-lang/rust-clippy#15249
For the builtin rustc, it should return "dev" as the release channel.
Clippy tests pass with this patch in both the Clippy standalone
repository and from within the compiler repository.
changelog: none
This removes preserved spaces after lint name, marginally reducing page
size.
Changing `~}}` into `-}}` will break things: lint name will touch copy
buttons on it's right side.
cc @GuillaumeGomez as one who touched this last time
changelog: none
