Return with a question mark was triggered in situations where the `?`
desuraging was performing error conversion via `Into`/`From`.
The desugared `?` produces a match over an expression with type
`std::ops::ControlFlow<B,C>` with `B:Result<Infallible, E:Error>` and
`C:Result<_, E':Error>`, and the arms perform the conversion. The patch
adds another check in the lint that checks that `E == E'`. If `E == E'`,
then the `?` is indeed unnecessary.
changelog: False Positive: `needless_return_with_question_mark` when
implicit Error Conversion occurs.
New lints `iter_filter_is_some` and `iter_filter_is_ok`
Adds a pair of lints that check for cases of an iterator over `Result` and `Option` followed by `filter` without being followed by `map` as that is covered already by a different, specialized lint.
Fixes#11843
PS, I also made some minor documentations fixes in a case where a double tick (`) was included.
---
changelog: New Lint: [`iter_filter_is_some`]
[#12004](https://github.com/rust-lang/rust/pull/12004)
changelog: New Lint: [`iter_filter_is_ok`]
[#12004](https://github.com/rust-lang/rust/pull/12004)
Do not consider `async { (impl IntoFuture).await }` as redundant
changelog: [`redundant_async_block`]: do not trigger on `IntoFuture` instances
Fix#11959
[`question_mark`]: also trigger on `return` statements
This fixes the false negative mentioned in #11993: the lint only used to check for `return` expressions, and not a statement containing a `return` expression (doesn't close the issue tho since there's still a useful suggestion that we could make, which is to suggest `.ok_or()?`/`.ok_or_else()?` for `else { return Err(..) }`)
changelog: [`question_mark`]: also trigger on `return` statements
fix typo in infinite loop lint
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: This fixes a small typo introduced in https://github.com/rust-lang/rust-clippy/pull/11829
Extend `UNNECESSARY_TO_OWNED` to handle `split`
Fixes https://github.com/rust-lang/rust-clippy/issues/9965.
When you have `to_string().split('a')` or equivalent, it'll suggest to remove the `to_owned`/`to_string` part.
r? `@flip1995`
changelog: Extend `UNNECESSARY_TO_OWNED` to handle `split`
Check whether out of bound when access a known length array with a constant index
fixes [Issue#11762](https://github.com/rust-lang/rust-clippy/issues/11762)
Issue#11762 points that `Array references with known length are not flagged when indexed out of bounds`.
To fix this problem, it is needed to add check for `Expr::Index`. We expand this issue include reference and direct accessing a array.
When we access a array with a constant index `off`, and already know the length `size`, if `off >= size`, these code will throw an error, instead rustc's lint checking them or runtime panic happening.
changelog: [`out_of_bound_indexing`]: Add check for illegal accessing known length array with a constant index
Adds a pair of lints that check for cases of an iterator over `Result`
and `Option` followed by `filter` without being followed by `map` as
that is covered already by a different, specialized lint.
changelog: New Lint: [`iter_filter_is_some`]
changelog: New Lint: [`iter_filter_is_ok`]
New Lint: `result_filter_map` / Mirror of `option_filter_map`
Added the `Result` mirror of `option_filter_map`.
changelog: New Lint: [`result_filter_map`]
I had to move around some code because the function def was too long 🙃.
I have also added some pattern checks on `option_filter_map`
don't visit nested bodies in `is_const_evaluatable`
Fixes#11939
This ICE happened in `if_let_some_else_none`, but the root problem is in one of the utils that it uses.
It is (was) possible for `is_const_evalutable` to visit nested bodies which would lead to it trying to get the type of one of the expressions with the wrong typeck table, which won't have the type stored.
Notably, for the expression `Bytes::from_static(&[0; 256 * 1024]);` in the linked issue, the array length is an anonymous const in which type checking happens on its own, so we can't use the typeck table of the enclosing function in there.
Visiting nested bodies is also not needed for checking whether an expression can be const, so I think it's safe to ignore just ignore them altogether.
changelog: Fix ICE when checking for constness in nested bodies
Add new `unconditional_recursion` lint
Currently, rustc `unconditional_recursion` doesn't detect cases like:
```rust
enum Foo {
A,
B,
}
impl PartialEq for Foo {
fn eq(&self, other: &Self) -> bool {
self == other
}
}
```
This is because the lint is currently implemented only for one level, and in the above code, `self == other` will then call `impl PartialEq for &T`, escaping from the detection. The fix for it seems to be a bit tricky (I started investigating potential solution to add one extra level of recursion [here](https://github.com/rust-lang/rust/compare/master...GuillaumeGomez:rust:trait-impl-recursion?expand=1) but completely broken at the moment).
I expect that this situation will remain for a while. In the meantime, I think it's acceptable to check it directly into clippy for the time being as a lot of easy cases like this one can be easily checked (next I plan to extend it to cover other traits like `ToString`).
changelog: Add new `unconditional_recursion` lint
Added the `Result` mirror of `option_filter_map` to catch
```
.into_iter().filter(Result::is_ok).map(Result::unwrap)
```
changelog: New Lint: [`result_filter_map`]
Co-authored-by: Alex Macleod <alex@macleod.io>
Fix binder handling in `unnecessary_to_owned`
fixes#11952
The use of `rebind` instead of `EarlyBinder::bind` isn't technically needed, but it is the semantically correct operation.
changelog: None
[`doc_markdown`] Recognize words followed by empty parentheses `()` for quoting
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`doc_markdown`] Recognize words followed by empty parentheses for quoting, e.g. `func()`.
---
Developers often write function/method names with trailing `()`, but `doc_markdown` lint did not consider that.
Old clippy suggestion was not very good:
```patch
-/// There is no try (do() or do_not()).
+/// There is no try (do() or `do_not`()).
```
New behavior recognizes function names such as `do()` even they contain no `_`/`::`; and backticks are suggested outside of the `()`:
```patch
-/// There is no try (do() or do_not()).
+/// There is no try (`do()` or `do_not()`).
```
Useless vec false positive
changelog: [`useless_vec`]: fix false positive in macros.
fixes#11861
We delay the emission of `useless_vec` lints to the check_crate_post stage, which allows us to effectively undo lints if we find that a `vec![]` expression is being used multiple times after macro expansion.
new lint to detect infinite loop
closes: #11438
changelog: add new lint to detect infinite loop
~*I'll change the lint name*~. Should I name it `infinite_loop` or `infinite_loops` is fine? Ahhhh, English is hard...
uninhabited_reference: new lint
Close#11851
The lint is implemented on function parameters and return types, as this is the place where the risk of exchanging references to uninhabited types is the highest. Other constructs, such as in a local variable,
would require the use of `unsafe` and will clearly be done on purpose.
changelog: [`uninhabited_reference`]: new lint
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.
