The `identity_op` lint was suggesting code fixes that resulted in
incorrect or broken code, due to missing parenthesis in the fix that
changed the semantics of the code.
For a binary expression, `left op right`, if the `left` was redundant,
it would check if the right side needed parenthesis, but if the `right`
was redundant, it would just assume that the left side did not need
parenthesis.
This can result in rustfix generating broken code and failing, or
generating code that has different behavior than before the fix. e.g.
`-(x + y + 0)` would turn into `-x + y`, changing the behavior, and
`1u64 + (x + y + 0i32) as u64` where `x: i32` and `y: i32` would turn
into `1u64 + x + y as u64`, creating an error where `x` cannot be added
to the other values, as it was never cast to `u64`.
This commit fixes both of these problems by always checking the
non-redundant child of a binary expression for needed parenthesis.
fixes#13470
changelog: [`identity_op`]: Fix suggested code that is broken or has
changed behavior
The author lint is not an internal lint, and should also be enabled, when Clippy
is distributed through rustup. This moves the author lint test cases back to
tests/ui.
needless_continue: check labels consistency before warning
changelog: [`needless_continue`]: check labels before warning about `continue` as the last statement in a loop body
Fix#13641
no_mangle attribute requires unsafe in Rust 2024
Tests without unsafe must not run in edition 2024. Also, error messages have been modified to include the full attribute, so that a use of `#[unsafe(no_mangle)]` does not produce an error message containing `#[no_mangle]`.
changelog: [`no_mangle_attribute`]: handle `#[unsafe(no_mangle)]` as well
Don't lint unnamed consts and nested items within functions in `missing_docs_in_private_items`
With this change we no longer require doc comments for `const _: ()` items as well as nested items in functions or other bodies. In both of those cases, rustdoc generates no documentation even with `--document-private-items`.
Fixes#13427 (first commit)
Fixes#13298 (second commit)
cc https://github.com/rust-lang/rust-clippy/issues/5736#issuecomment-668524296
changelog: [`missing_docs_in_private_items`]: avoid linting in more cases where rustdoc generates no documentation
The `identity_op` lint was suggesting code fixes that resulted
in incorrect or broken code, due to missing parenthesis in the fix
that changed the semantics of the code.
For a binary expression, `left op right`, if the `left` was redundant,
it would check if the right side needed parenthesis, but if the `right`
was redundant, it would just assume that the left side did not need
parenthesis.
This can result in either rustfix generating broken code and failing,
or code that has different behavior than before the fix.
e.g. `-(x + y + 0)` would turn into `-x + y`, changing the behavior,
and `1u64 + (x + y + 0i32) as u64` where `x: i32` and `y: i32` would
turn into `1u64 + x + y as u64`, creating broken code where `x` cannot
be added to the other values, as it was never cast to `u64`.
This commit fixes both of these cases by always checking the
non-redundant child of a binary expression for needed parenthesis, and
makes it so if we need parenthesis, but they already exist, we don't add
any redundant ones.
Fixes#13470
[`infinite_loops`]: fix incorrect suggestions on async functions/closures
closes: #12338
I intend to fix this in #12421 but got distracted by some other problems in the same lint, delaying the process of closing the actual issue. So here's a separated PR that only focus on the issue and nothing else.
---
changelog: [`infinite_loops`]: fix suggestion error on async functions/closures
Cleanup code suggestion for `into_iter_without_iter`
Reorder the suggested code for the `IntoIterator` to match the ordering of the trait declaration:
```rust
impl IntoIterator for ... {
type Item = ...;
type IntoIter = ...;
```
changelog: none
Add 'CoAP' to doc-valid-idents
CoAP is a name of a network protocol common in embedded systems; one would talk in documentation about "a CoAP server" or "a CoAP client" without referring to a specific type.
This PR fixes false positives that arise from that use.
changelog: [`doc_markdown`]: Add CoAP to `doc-valid-idents`.
As this review is identical in structure to https://github.com/rust-lang/rust-clippy/pull/13460, I'm asking for a the same reviewer (if that works):
r? `@Centri3`
Reorder the suggested code for the `IntoIterator` to match the ordering of the trait declaration:
```rust
impl IntoIterator for ... {
type Item = ...;
type IntoIter = ...;
```
Fix allow_attributes when expanded from some macros
fixes#13349
The issue here was that the start pattern being matched on the original source code was not specific enough. When using derive macros or in the issue case a `#[repr(C)]` the `#` would match the start pattern meaning that the expanded macro appeared to be unchanged and clippy would lint it.
The change I made was to make the matching more specific by matching `#[ident` at the start. We still need the second string to match just the ident on its own because of things like `#[cfg_attr(panic = "unwind", allow(unused))]`.
I also noticed some typos with start and end, these code paths weren't being reached so this doesn't fix anything.
changelog: FP: [`allow_attributes`]: don't trigger when expanded from some macros
This lint checks for code that looks like
```rust
let something : Vec<_> = (0..100).map(|_| {
1 + 2 + 3
}).collect();
```
which is more clear as
```rust
let something : Vec<_> = std::iter::repeat_with(|| {
1 + 2 + 3
}).take(100).collect();
```
or
```rust
let something : Vec<_> =
std::iter::repeat_n(1 + 2 + 3, 100)
.collect();
```
That is, a map over a range which does nothing with the parameter
passed to it is simply a function (or closure) being called `n`
times and could be more semantically expressed using `take`.
Lint against getting pointers from immediately dropped temporaries
Fixes#123613
## Changes:
1. New lint: `dangling_pointers_from_temporaries`. Is a generalization of `temporary_cstring_as_ptr` for more types and more ways to get a temporary.
2. `temporary_cstring_as_ptr` is removed and marked as renamed to `dangling_pointers_from_temporaries`.
3. `clippy::temporary_cstring_as_ptr` is marked as renamed to `dangling_pointers_from_temporaries`.
4. Fixed a false positive[^fp] for when the pointer is not actually dangling because of lifetime extension for function/method call arguments.
5. `core::cell::Cell` is now `rustc_diagnostic_item = "Cell"`
## Questions:
- [ ] Instead of manually checking for a list of known methods and diagnostic items, maybe add some sort of annotation to those methods in library and check for the presence of that annotation? https://github.com/rust-lang/rust/pull/128985#issuecomment-2318714312
## Known limitations:
### False negatives[^fn]:
See the comments in `compiler/rustc_lint/src/dangling.rs`
1. Method calls that are not checked for:
- `temporary_unsafe_cell.get()`
- `temporary_sync_unsafe_cell.get()`
2. Ways to get a temporary that are not recognized:
- `owning_temporary.field`
- `owning_temporary[index]`
3. No checks for ref-to-ptr conversions:
- `&raw [mut] temporary`
- `&temporary as *(const|mut) _`
- `ptr::from_ref(&temporary)` and friends
[^fn]: lint **should** be emitted, but **is not**
[^fp]: lint **should not** be emitted, but **is**
fix incorrect suggestion for `!(a >= b) as i32 == c`
fixes#12761
The expression `!(a >= b) as i32 == c` got simplified to `a < b as i32 == c`, but this is a syntax error.
The result we want is `(a < b) as i32 == c`.
This is fixed by adding a parenthesis to the suggestion given in `check_simplify_not` when the boolean expression is casted.
changelog: [`nonminimal_bool`]: fix incorrect suggestion for `!(a >= b) as i32 == c`
(Big performance change) Do not run lints that cannot emit
Before this change, adding a lint was a difficult matter because it always had some overhead involved. This was because all lints would run, no matter their default level, or if the user had `#![allow]`ed them. This PR changes that. This change would improve both the Rust lint infrastructure and Clippy, but Clippy will see the most benefit, as it has about 900 registered lints (and growing!)
So yeah, with this little patch we filter all lints pre-linting, and remove any lint that is either:
- Manually `#![allow]`ed in the whole crate,
- Allowed in the command line, or
- Not manually enabled with `#[warn]` or similar, and its default level is `Allow`
As some lints **need** to run, this PR also adds **loadbearing lints**. On a lint declaration, you can use the ``@eval_always` = true` marker to label it as loadbearing. A loadbearing lint will never be filtered (it will always run)
Fixes#106983
Add units/unit prefixes of frequency to doc-valid-idents
These units/unit prefixes often come up in the embedded world.
Should this PR also modify the `test_units` test? It seems only concerned with data units currently; should it also test frequency units?
changelog: [`doc_markdown`]: Add MHz, GHz, and THz to `doc-valid-idents`.
Add debug assertions for empty replacements and overlapping spans
rustc has debug assertions [^1] [^2] that check that a substitution doesn't have an empty suggestion string and an empty span at the same time, as well as that spans in multipart suggestions don't overlap.
However, since we link to the rustc-dev distributed compiler, these debug assertions are always disabled and so we never actually run them.
This leads to the problem that the debug ICE is not necessarily caught in the PR and only triggered in the rust repo sync, and in one of the last syncs this was a blocker and delayed the sync by several weeks because the fix was not obvious.
So this PR essentially copies the checks over and runs them in clippy debug builds as well, so that we can catch these errors in PRs directly.
-----
As for the second commit, this also *did* cause an ICE in a sync before and was fixed in the sync PR (see https://github.com/rust-lang/rust/pull/120345#issuecomment-1911005554), but it seems like that commit didn't make it back into the clippy repo (cc `@flip1995),` so the fixed code is in the rust repo but not in the clippy repo.
changelog: none
[^1]: https://doc.rust-lang.org/1.82.0/nightly-rustc/src/rustc_errors/diagnostic.rs.html#1019
[^2]: https://doc.rust-lang.org/1.82.0/nightly-rustc/src/rustc_errors/diagnostic.rs.html#932
