Add a function to check whether binary oprands are nontrivial
fixes [#issue11885](https://github.com/rust-lang/rust-clippy/issues/11885)
It's hard to check whether operator is overrided through context of lint.
So, assume non-trivial structure like tuple, array or sturt, using a overrided binary operator in this lint, which might cause a side effict.
This is not detected before.
Althrough this might weaken the ability of this lint, it may more useful than before. Maybe this lint will cause an error, but now, it not. And assuming side effect of non-trivial structure with operator is not a bad thing, right?
changelog: Fix: [`no_effect`] check if binary operands are nontrivial
fix(ptr_as_ptr): handle `std::ptr::null{_mut}`
close rust-lang#11066
close rust-lang#11665
close rust-lang#11911
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`ptr_as_ptr`]: handle `std::ptr::null` and `std::ptr::null_mut`
needless_borrows_for_generic_args: Handle when field operand impl Drop
Before this fix, the lint had a false positive, namely when a reference was taken to a field when the field operand implements a custom Drop. The compiler will refuse to partially move a type that implements Drop, because that would put the type in a weird state.
## False Positive Example (Fixed)
```rs
struct CustomDrop(String);
impl Drop for CustomDrop {
fn drop(&mut self) {}
}
fn check_str<P: AsRef<str>>(_to: P) {}
fn test() {
let owner = CustomDrop(String::default());
check_str(&owner.0); // Don't lint. `owner` can't be partially moved because it impl Drop
}
```
changelog: [`needless_borrows_for_generic_args`]: Handle when field operand impl Drop
Update regex-syntax to support new word boundry assertions
From the regex v1.10.0 release notes [1]:
This is a new minor release of regex that adds support for start
and end word boundary assertions. [...]
The new word boundary assertions are:
• \< or \b{start}: a Unicode start-of-word boundary (\W|\A
on the left, \w on the right).
• \> or \b{end}: a Unicode end-of-word boundary (\w on the
left, \W|\z on the right)).
• \b{start-half}: half of a Unicode start-of-word boundary
(\W|\A on the left).
• \b{end-half}: half of a Unicode end-of-word boundary
(\W|\z on the right).
[1]: https://github.com/rust-lang/regex/blob/master/CHANGELOG.md#1100-2023-10-09
changelog: [`regex`]: add support for start and end word boundary assertions ("\<", "\b{start}", etc.) introduced in regex v0.10
Check whether operator is overrided with a `struct` operand.
The struct here refers to `struct`, `enum`, `union`.
Add and fix test for `no_effect` lint.
From the regex v1.10.0 release notes [1]:
This is a new minor release of regex that adds support for start
and end word boundary assertions. [...]
The new word boundary assertions are:
• \< or \b{start}: a Unicode start-of-word boundary (\W|\A
on the left, \w on the right).
• \> or \b{end}: a Unicode end-of-word boundary (\w on the
left, \W|\z on the right)).
• \b{start-half}: half of a Unicode start-of-word boundary
(\W|\A on the left).
• \b{end-half}: half of a Unicode end-of-word boundary
(\W|\z on the right).
[1]: https://github.com/rust-lang/regex/blob/master/CHANGELOG.md#1100-2023-10-09
expending lint [`blocks_in_if_conditions`] to check match expr as well
closes: #11814
changelog: rename lint `blocks_in_if_conditions` to [`blocks_in_conditions`] and expand it to check blocks in match scrutinees
[`missing_asserts_for_indexing`]: accept length equality checks
Fixes#11835
The lint now allows indexing with indices 0 and 1 when an `assert!(x.len() == 2);` is found.
(Also fixed a typo in the doc example)
changelog: [`missing_asserts_for_indexing`]: accept len equality checks as a valid assertion
Stabilize C string literals
RFC: https://rust-lang.github.io/rfcs/3348-c-str-literal.html
Tracking issue: https://github.com/rust-lang/rust/issues/105723
Documentation PR (reference manual): https://github.com/rust-lang/reference/pull/1423
# Stabilization report
Stabilizes C string and raw C string literals (`c"..."` and `cr#"..."#`), which are expressions of type [`&CStr`](https://doc.rust-lang.org/stable/core/ffi/struct.CStr.html). Both new literals require Rust edition 2021 or later.
```rust
const HELLO: &core::ffi::CStr = c"Hello, world!";
```
C strings may contain any byte other than `NUL` (`b'\x00'`), and their in-memory representation is guaranteed to end with `NUL`.
## Implementation
Originally implemented by PR https://github.com/rust-lang/rust/pull/108801, which was reverted due to unintentional changes to lexer behavior in Rust editions < 2021.
The current implementation landed in PR https://github.com/rust-lang/rust/pull/113476, which restricts C string literals to Rust edition >= 2021.
## Resolutions to open questions from the RFC
* Adding C character literals (`c'.'`) of type `c_char` is not part of this feature.
* Support for `c"..."` literals does not prevent `c'.'` literals from being added in the future.
* C string literals should not be blocked on making `&CStr` a thin pointer.
* It's possible to declare constant expressions of type `&'static CStr` in stable Rust (as of v1.59), so C string literals are not adding additional coupling on the internal representation of `CStr`.
* The unstable `concat_bytes!` macro should not accept `c"..."` literals.
* C strings have two equally valid `&[u8]` representations (with or without terminal `NUL`), so allowing them to be used in `concat_bytes!` would be ambiguous.
* Adding a type to represent C strings containing valid UTF-8 is not part of this feature.
* Support for a hypothetical `&Utf8CStr` may be explored in the future, should such a type be added to Rust.
Before this fix, the lint had a false positive, namely when a reference
was taken to a field when the field operand implements a custom Drop.
The compiler will refuse to partially move a type that implements Drop,
because that would put the operand in a weird state. See added
regression test.
`option_if_let_else`: do not trigger on expressions returning `()`
Fix#11893
Trigerring on expressions returning `()` uses the arguments of the `map_or_else()` rewrite only for their side effects. This does lead to code which is harder to read than the original.
changelog: [`option_if_let_else`]: do not trigger on unit expressions
add lint against unit tests in doctests
During RustLab, Alice Ryhl brought to my attention that the Andoid team stumbled over the fact that if one attempts to write a unit test within a doctest, it will be summarily ignored. So this lint should help people wondering why their tests won't run.
---
changelog: New lint: [`test_attr_in_doctest`]
[#11872](https://github.com/rust-lang/rust-clippy/pull/11872)
Fix#11893
Trigerring on expressions returning `()` uses the arguments of the
`map_or_else()` rewrite only for their side effects. This does lead
to code which is harder to read than the original.
[`redundant_guards`]: catch `is_empty`, `starts_with` and `ends_with` on slices and `str`s
Fixes#11807
Few things worth mentioning:
- Taking `snippet`s is now done at callsite, instead of passing a span and doing it in `emit_redundant_guards`. This is because we now need custom suggestion strings in certain places, like `""` for `str::is_empty`.
- This now uses `snippet` instead of `snippet_with_applicability`. I don't think this really makes any difference for `MaybeIncorrect`, though?
- This could also lint byte strings, as they're of type `&[u8; N]`, but that can be ugly so I decided to leave it out for now
changelog: [`redundant_guards`]: catch `str::is_empty`, `slice::is_empty`, `slice::starts_with` and `slice::ends_with`
[`redundant_closure_call`]: avoid duplicated `async` keyword when triggering on closure that returns `async` block
close#11357
----
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`redundant_closure_call`]: avoid duplicated `async` keyword when triggering on closure that returns `async` block
Don't suggest `a.mul_add(b, c)` if parameters are not float
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 parameters, the suggestion was wrong.
Fixes#11831
changelog: [`suboptimal_float`]: Don't suggest `a.mul_add(b, c)` if parameters are not f32/f64
[`ptr_arg`]: recognize methods that also exist on slices
Fixes#11816
Not a new lint, just a very small improvement to the existing `ptr_arg` lint which would have caught the linked issue.
The problem was that the lint checks if a `Vec`-specific method was called, that is, if the receiver is `Vec<_>`.
This is the case for `len` and `is_empty`, however these methods also exist on slices so we can still lint there.
This logic exists in a different lint, so we can just reuse that here.
Interestingly, there was even a comment up top that explained what it should have been doing, but the logic for it just wasn't there?
changelog: [`ptr_arg`]: recognize methods that also exist on slices
<sub>Also, this is my 100th PR to clippy 🎉 </sub>
`manual_try_fold`: check that `fold` is really `Iterator::fold`
Fix#11876
changelog: [`manual_try_fold`]: suggest using `try_fold` only for `Iterator::fold` uses
Create new lint `option_map_or_err_ok`
Fixes#10045.
For the following code:
```rust
let opt = Some(1);
opt.map_or(Err("error"), Ok);
```
It suggests to instead write:
```rust
let opt = Some(1);
opt.ok_or("error");
```
r? `@flip1995`
changelog: Create new lint `option_map_or_err_ok`
suggest alternatives to iterate an array of ranges
works towards #7125
changelog: [`single_element_loop`]: suggest better syntax when iterating over an array of a single range
`@thinkerdreamer` and myself worked on this issue during a workshop by `@llogiq` at the RustLab 2023 conference. It is our first contribution to clippy.
When iterating over an array of only one element, _which is a range_, our change suggests to replace the array with the contained range itself. Additionally, a hint is printed stating that the user probably intended to iterate over the range and not the array. If the single element in the array is not a range, the previous suggestion in the form of `let {pat_snip} = {prefix}{arg_snip};{block_str}`is used.
This change lints the array with the single range directly, so any prefixes or suffixes are covered as well.
[`deprecated_semver`]: Allow `#[deprecated(since = "TBD")]`
"TBD" is allowed by rustdoc, saying that it will be deprecated in a future version. rustc will also not actually warn on it.
I found this while checking the rust-lang/rust with clippy.
changelog: [`deprecated_semver`]: allow using `since = "TBD"`
[`missing_asserts_for_indexing`]: work with bodies instead of blocks separately
Fixes#11856
Before this change, this lint would check blocks independently of each other, which means that it misses `assert!()`s from parent blocks.
```rs
// check_block
assert!(x.len() > 1);
{
// check_block
// no assert here
let _ = x[0] + x[1];
}
```
This PR changes it to work with bodies rather than individual blocks. That means that a function will be checked in one go and we can remember if an `assert!` occurred anywhere.
Eventually it would be nice to have a more control flow-aware analysis, possibly by rewriting it as a MIR lint, but that's more complicated and I wanted this fixed first.
changelog: [`missing_asserts_for_indexing`]: accept `assert!`s from parent blocks
