[`mem_replace_with_default`] No longer triggers on unused expression
changelog:[`mem_replace_with_default`]: No longer triggers on unused expression
Change [`mem_replace_with_default`] to not trigger on unused expression because the lint from `#[must_use]` handle this case better.
fixes: #5586
Warn on references casting to bigger memory layout
This PR extends the [`invalid_reference_casting`](https://doc.rust-lang.org/rustc/lints/listing/deny-by-default.html#invalid-reference-casting) lint (*deny-by-default*) which currently lint on `&T -> &mut T` casting to also lint on `&(mut) A -> &(mut) B` where `size_of::<B>() > size_of::<A>()` (bigger memory layout requirement).
The goal is to detect such cases:
```rust
let u8_ref: &u8 = &0u8;
let u64_ref: &u64 = unsafe { &*(u8_ref as *const u8 as *const u64) };
//~^ ERROR casting references to a bigger memory layout is undefined behavior
let mat3 = Mat3 { a: Vec3(0i32, 0, 0), b: Vec3(0, 0, 0), c: Vec3(0, 0, 0) };
let mat3 = unsafe { &*(&mat3 as *const _ as *const [[i64; 3]; 3]) };
//~^ ERROR casting references to a bigger memory layout is undefined behavior
```
This is added to help people who write unsafe code, especially when people have matrix struct that they cast to simple array of arrays.
EDIT: One caveat, due to the [`&Header`](https://github.com/rust-lang/unsafe-code-guidelines/issues/256) uncertainty the lint only fires when it can find the underline allocation.
~~I have manually tested all the new expressions that warn against Miri, and they all report immediate UB.~~
r? ``@est31``
fix: ICE when array index exceeds usize
fixes#12253
This PR fixes ICE in `indexing_slicing` as it panics when the index of the array exceeds `usize`.
changelog: none
Don't allow derive macros to silence `disallowed_macros`
fixes#12254
The implementation is a bit of a hack, but "works". A derive expanding to another derive won't work properly, but we shouldn't be linting those anyways.
changelog: `disallowed_macros`: Don't allow derive macros to silence their own expansion
stop linting [`blocks_in_conditions`] on `match` with weird attr macro case
should fixes: #12016
---
changelog: [`blocks_in_conditions`] - fix FP on `match` with weird attr macro
This might not be the best solution, as the root cause (i think?) is the `span` of block was incorrectly given by the compiler?
I'm open to better solutions
A lot of cases of the "noise" cases of `similar_names` come from two
idents with a different first letter, which is easy enough to
differentiate visually but causes this lint to be raised.
Do not raise the lint in these cases, as long as the first character
does not have a lookalike.
Link: https://github.com/rust-lang/rust-clippy/issues/10926
Fix issue #12034: add autofixes for unnecessary_fallible_conversions
fixes#12034
Currently, the `unnecessary_fallible_conversions` lint was capable of autofixing expressions like `0i32.try_into().unwrap()`. However, it couldn't autofix expressions in the form of `i64::try_from(0i32).unwrap()` or `<i64 as TryFrom<i32>>::try_from(0).unwrap()`.
This pull request extends the functionality to correctly autofix these latter forms as well.
changelog: [`unnecessary_fallible_conversions`]: Add autofixes for more forms
[`unconditional_recursion`]: compare by `Ty`s instead of `DefId`s
Fixes#12154Fixes#12181 (this was later edited in, so the rest of the description refers to the first linked issue)
Before this change, the lint would work with `DefId`s and use those to compare types. This PR changes it to compare types directly. It fixes the linked issue, but also other false positives I found in a lintcheck run. For example, one of the issues is that some types don't have `DefId`s (primitives, references, etc., leading to possible FNs), and the helper function used to extract a `DefId` didn't handle type parameters.
Another issue was that the lint would use `.peel_refs()` in a few places where that could lead to false positives (one such FP was in the `http` crate). See the doc comment on one of the added functions and also the test case for what I mean.
The code in the linked issue was linted because the receiver type is `T` (a `ty::Param`), which was not handled in `get_ty_def_id` and returned `None`, so this wouldn't actually *get* to comparing `self_arg != ty_id` here, and skip the early-return:
70573af31e/clippy_lints/src/unconditional_recursion.rs (L171-L178)
This alone could be fixed by doing something like `&& get_ty_def_id(ty).map_or(true, |ty_id)| self_arg != ty_id)`, but we don't really need to work with `DefId`s in the first place, I don't think.
changelog: [`unconditional_recursion`]: avoid linting when the other comparison type is a type parameter
Fix false positive in `redundant_type_annotations` lint
This PR changes the `redundant_type_annotations` lint to allow slice type annotations (i.e., `&[u8]`) for byte string literals. It will still consider _array_ type annotations (i.e., `&[u8; 4]`) as redundant. The reasoning behind this is that the type of byte string literals is by default a reference to an array, but, by using a type annotation, you can force it to be a slice. For example:
```rust
let a: &[u8; 4] = b"test";
let b: &[u8] = b"test";
```
Now, the type annotation for `a` will still be linted (as it is still redundant), but the type annotation for `b` will not.
Fixes#12212.
changelog: [`redundant_type_annotations`]: Fix false positive with byte string literals
Return `Some` from `walk_to_expr_usage` more
fixes#11786
supersedes #11097
The code removed in the first commit would have needed changes due to the second commit. Since it's useless it just gets removed instead.
changelog: `needless_borrow`: Fix linting in tuple and array expressions.
[`redundant_locals`]: take by-value closure captures into account
Fixes#12225
The same problem in the linked issue can happen to regular closures too, and conveniently async blocks are closures in the HIR so fixing closures will fix async blocks as well.
changelog: [`redundant_locals`]: avoid linting when redefined variable is captured by-value
make matching on NaN a hard error, and remove the rest of illegal_floating_point_literal_pattern
These arms would never be hit anyway, so the pattern makes little sense. We have had a future-compat lint against float matches in general for a *long* time, so I hope we can get away with immediately making this a hard error.
This is part of implementing https://github.com/rust-lang/rfcs/pull/3535.
Closes https://github.com/rust-lang/rust/issues/41620 by removing the lint.
https://github.com/rust-lang/reference/pull/1456 updates the reference to match.
Add new lint: `ref_as_ptr`
Fixes#10130
Added new lint `ref_as_ptr` that checks for conversions from references to pointers and suggests using `std::ptr::from_{ref, mut}` instead.
The name is different than suggested in the issue (`as_ptr_cast`) since there were some other lints with similar names (`ptr_as_ptr`, `borrow_as_ptr`) and I wanted to follow the convention.
Note that this lint conflicts with the `borrow_as_ptr` lint in the sense that it recommends changing `&foo as *const _` to `std::ptr::from_ref(&foo)` instead of `std::ptr::addr_of!(foo)`. Personally, I think the former is more readable and, in contrast to `addr_of` macro, can be also applied to temporaries (cf. #9884).
---
changelog: New lint: [`ref_as_ptr`]
[#12087](https://github.com/rust-lang/rust-clippy/pull/12087)
add configuration for [`wildcard_imports`] to ignore certain imports
fixes: #11428
changelog: add configuration `ignored-wildcard-imports` for lint [`wildcard_imports`]
Fixed FP in `unused_io_amount` for Ok(lit), unrachable! and unwrap de…
…sugar
Fixes fp caused by linting on Ok(_) for all cases outside binding.
We introduce the following rules for match exprs.
- `panic!` and `unreachable!` are treated as consumed.
- `Ok( )` patterns outside `DotDot` and `Wild` are treated as consuming.
changelog: FP [`unused_io_amount`] when matching Ok(literal) or unreachable
fixes#12208
r? `@blyxyas`
We introduce the following rules for match exprs.
- `panic!` and `unreachable!` are treated as consumption.
- guard expressions in any arm imply consumption.
For match exprs:
- Lint only if exacrtly 2 non-consuming arms exist
- Lint only if one arm is an `Ok(_)` and the other is `Err(_)`
Added additional requirement that for a block return expression
that is a match, the source must be `Normal`.
changelog: FP [`unused_io_amount`] when matching Ok(literal)
`Diagnostic::keys`, which is used for hashing and equating diagnostics,
has a surprising behaviour: it ignores children, but only for lints.
This was added in #88493 to fix some duplicated diagnostics, but it
doesn't seem necessary any more.
This commit removes the special case and only four tests have changed
output, with additional errors. And those additional errors aren't
exact duplicates, they're just similar. For example, in
src/tools/clippy/tests/ui/same_name_method.rs we currently have this
error:
```
error: method's name is the same as an existing method in a trait
--> $DIR/same_name_method.rs:75:13
|
LL | fn foo() {}
| ^^^^^^^^^^^
|
note: existing `foo` defined here
--> $DIR/same_name_method.rs:79:9
|
LL | impl T1 for S {}
| ^^^^^^^^^^^^^^^^
```
and with this change we also get this error:
```
error: method's name is the same as an existing method in a trait
--> $DIR/same_name_method.rs:75:13
|
LL | fn foo() {}
| ^^^^^^^^^^^
|
note: existing `foo` defined here
--> $DIR/same_name_method.rs:81:9
|
LL | impl T2 for S {}
| ^^^^^^^^^^^^^^^^
```
I think printing this second argument is reasonable, possibly even
preferable to hiding it. And the other cases are similar.
Add regression ui test for #2371Fixes#2371.
#2371 seems to already be handled correctly in the lint. This PR adds a ui regression test so we can close it.
r? `@blyxyas`
changelog: Add regression ui test for #2371
[fix] [`redundant_closure_for_method_calls`] Suggest relative paths for local modules
Fixes#10854.
Currently, `redundant_closure_for_method_calls` suggest incorrect paths when a method defined on a struct within inline mod is referenced (see the description in the aforementioned issue for an example; also see [this playground link](https://play.rust-lang.org/?version=stable&mode=release&edition=2021&gist=f7d3c5b2663c9bd3ab7abdb0bd38ee43) for the current-version output for the test cases added in this PR). It will now try to construct a relative path path to the module and suggest it instead.
changelog: [`redundant_closure_for_method_calls`] Fix incorrect path suggestions for types within local modules
FP: `needless_return_with_question_mark` with implicit Error Conversion
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.
fixes: #11982
fix: incorrect suggestions generated by `manual_retain` lint
fixes#10393, fixes#11457, fixes#12081#10393: In the current implementation of `manual_retain`, if the argument to the closure is matched using tuple, they are all treated as the result of a call to `map.into_iter().filter(<f>)`. However, such tuple pattern matching can also occur in many different containers that stores tuples internally. The correct approach is to apply different lint policies depending on whether the receiver of `into_iter` is a map or not.
#11457 and #12081: In the current implementation of `manual_retain`, if the argument to the closure is `Binding`, the closure will be used directly in the `retain` method, which will result in incorrect suggestion because the first argument to the `retain` closure may be of a different type. In addition, if the argument to the closure is `Ref + Binding`, the lint will simply remove the `Ref` part and use the `Binding` part as the argument to the new closure, which will lead to bad suggestion for the same reason. The correct approach is to detect each of these cases and apply lint suggestions conservatively.
changelog: [`manual_retain`] refactor and add check for various patterns
Fix/Issue11932: assert* in multi-condition after unrolling will cause lint `nonminimal_bool` emit warning
fixes [Issue#11932](https://github.com/rust-lang/rust-clippy/issues/11932)
After `assert`, `assert_eq`, `assert_ne`, etc, assert family marcos unrolling in multi-condition expressions, lint `nonminimal_bool` will recognize whole expression as a entirety, analyze each simple condition expr of them, and check whether can simplify them.
But `assert` itself is a entirety to programmers, we don't need to lint on `assert`. This commit add check whether lint snippet contains `assert` when try to warning to an expression.
changelog: [`nonminimal_bool`] add check for condition expression
[`never_loop`]: recognize desugared `try` blocks
Fixes#12205
The old code assumed that only blocks with an explicit label can be jumped to (using `break`). This is mostly correct except for `try` desugaring, where the `?` operator is rewritten to a `break` to that block, even without a label on the block. `Block::targeted_by_break` is a little more accurate than just checking if a block has a label in that regard, so we should just use that instead
changelog: [`never_loop`]: avoid linting when `?` is used inside of a try block
Fixed FP in `redundant_closure_call` when closures are passed to macros
There are cases where the closure call is needed in some macros, this in particular occurs when the closure has parameters. To handle this case, we allow the lint when there are no parameters in the closure, or the closure is outside a macro invocation.
fixes: #11274#1553
changelog: FP: [`redundant_closure_call`] when closures with parameters are passed in macros.
Warn if an item coming from more recent version than MSRV is used
Part of https://github.com/rust-lang/rust-clippy/issues/6324.
~~Currently, the lint is not working for the simple reason that the `stable` attribute is not kept in dependencies. I'll send a PR to rustc to see if they'd be okay with keeping it.~~
EDIT: There was actually a `lookup_stability` function providing this information, so all good now!
cc `@epage`
changelog: create new [`incompatible_msrv`] lint
remove StructuralEq trait
The documentation given for the trait is outdated: *all* function pointers implement `PartialEq` and `Eq` these days. So the `StructuralEq` trait doesn't really seem to have any reason to exist any more.
One side-effect of this PR is that we allow matching on some consts that do not implement `Eq`. However, we already allowed matching on floats and consts containing floats, so this is not new, it is just allowed in more cases now. IMO it makes no sense at all to allow float matching but also sometimes require an `Eq` instance. If we want to require `Eq` we should adjust https://github.com/rust-lang/rust/pull/115893 to check for `Eq`, and rule out float matching for good.
Fixes https://github.com/rust-lang/rust/issues/115881
[`multiple_crate_versions`]: add a configuration option for allowed duplicate crates
Closes#12176
changelog: [`multiple_crate_versions`]: add a configuration option for allowed duplicate crates
respect `#[allow]` attributes in `single_call_fn` lint
Fixes#12182
If we delay linting to `check_crate_post`, we need to use `span_lint_hir_and_then`, since otherwise it would only respect those lint level attributes at the crate root.
<sub>... maybe we can have an internal lint for this somehow?</sub>
changelog: respect `#[allow]` attributes in `single_call_fn` lint
Don't emit `derive_partial_eq_without_eq` lint if the type has the `non_exhaustive` attribute
Part of https://github.com/rust-lang/rust-clippy/issues/9063.
If a type has a field/variant with the `#[non_exhaustive]` attribute or the type itself has it, then do no emit the `derive_partial_eq_without_eq` lint.
changelog: Don't emit `derive_partial_eq_without_eq` lint if the type has the `non_exhaustive` attribute
`unused_io_amount` captures `Ok(_)`s
Partial rewrite of `unused_io_amount` to lint over `Ok(_)` and `Ok(..)`.
Moved the check to `check_block` to simplify context checking for expressions and allow us to check only some expressions.
For match (expr, arms) we emit a lint for io ops used on `expr` when an arm is `Ok(_)|Ok(..)`. Also considers the cases when there are guards in the arms and `if let Ok(_) = ...` cases.
For `Ok(_)` and `Ok(..)` it emits a note indicating where the value is ignored.
changelog: False Negatives [`unused_io_amount`]: Extended `unused_io_amount` to catch `Ok(_)`s in `If let` and match exprs.
Closes#11713
r? `@giraffate`
Partial rewrite of `unused_io_account` to lint over Ok(_).
Moved the check to `check_block` to simplify context checking for
expressions and allow us to check only some expressions.
For match (expr, arms) we emit a lint for io ops used on `expr` when an
arm is `Ok(_)`. Also considers the cases when there are guards in the
arms. It also captures `if let Ok(_) = ...` cases.
For `Ok(_)` it emits a note indicating where the value is ignored.
changelog: False Negatives [`unused_io_amount`]: Extended
`unused_io_amount` to catch `Ok(_)`s in `If let` and match exprs.
no_effect_underscore_binding: _ prefixed variables can be used
Prefixing a variable with a `_` does not mean that it will not be used. If such a variable is used later, do not warn about the fact that its initialization does not have a side effect as this is fine.
changelog: [`no_effect_underscore_binding`]: warn only if variable is unused
Fix#12166
Add . to end of lint lists in configuration + Fix typo in pub_underscore_fields_behavior
Fixes https://github.com/rust-lang/rust-clippy/pull/10283#issuecomment-1890600381
In the "/// Lint: " list on each configuration option, you have to end with a dot. If the lint list doesn't have a dot, the configuration won't have documentation.
This PR adds those missing dots in some of the configuration, thus also adding their documentation.
changelog: Fix bug where a lot of config documentation wasn't showing.
changelog: Fix typo in `pub_underscore_fields_behavior` (`PublicallyExported` -> `PubliclyExported`)
Prefixing a variable with a `_` does not mean that it will not be used.
If such a variable is used later, do not warn about the fact that its
initialization does not have a side effect as this is fine.
Fix error warning span for issue12045
fixes [Issue#12045](https://github.com/rust-lang/rust-clippy/issues/12045)
In issue#12045, unexpected warning span occurs on attribute `#[derive(typed_builder::TypedBuilder)]`, actually the warning should underline `_lifetime`.
In the source code we can find that the original intend is to warning on `ident.span`, but in this case, `stmt.span` is unequal with `ident.span`. So, fix the nit here is fine.
Besides, `ident.span` have an accurate range than `stmt.span`.
changelog: [`no_effect_underscore_binding`]: correct warning span
fix FP on [`semicolon_if_nothing_returned`]
fixes: #12123
---
changelog: fix FP on [`semicolon_if_nothing_returned`] which suggesting adding semicolon after attr macro
Fix [`multiple_crate_versions`] to correctly normalize package names to avoid missing the local one
Fixes#12145
changelog: [`multiple_crate_versions`]: correctly normalize package name
Correctly handle type relative in trait_duplication_in_bounds lint
Fixes#9961.
The generic bounds were not correctly checked and left out `QPath::TypeRelative`, making different bounds look the same and generating invalid errors (and fix).
r? `@blyxyas`
changelog: [`trait_duplication_in_bounds`]: Correctly handle type relative.
`read_zero_byte_vec` refactor for better heuristics
Fixes#9274
Previously, the implementation of `read_zero_byte_vec` only checks for the next statement after the vec init. This fails when there is a block with statements that are expanded and walked by the old visitor.
This PR refactors so that:
1. It checks if there is a `resize` on the vec
2. It works on blocks properly
e.g. This should properly lint now:
```
let mut v = Vec::new();
{
f.read(&mut v)?;
//~^ ERROR: reading zero byte data to `Vec`
}
```
changelog: [`read_zero_byte_vec`] Refactored for better heuristics
Add suspicious_open_options lint.
changelog: [`suspicious_open_options`]: Checks for the suspicious use of std::fs::OpenOptions::create() without an explicit OpenOptions::truncate().
create() alone will either create a new file or open an existing file. If the file already exists, it will be overwritten when written to, but the file will not be truncated by default. If less data is written to the file than it already contains, the remainder of the file will remain unchanged, and the end of the file will contain old data.
In most cases, one should either use `create_new` to ensure the file is created from scratch, or ensure `truncate` is called so that the truncation behaviour is explicit. `truncate(true)` will ensure the file is entirely overwritten with new data, whereas `truncate(false)` will explicitely keep the default behavior.
```rust
use std::fs::OpenOptions;
OpenOptions::new().create(true).truncate(true);
```
- [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`
Correctly suggest std or core path depending if this is a `no_std` crate
A few lints emit suggestions using `std` paths whether or not this is a `no_std` crate, which is an issue when running `rustfix` afterwards. So in case this is an item that is defined in both `std` and `core`, we need to check if the crate is `no_std` to emit the right path.
r? `@llogiq`
changelog: Correctly suggest std or core path depending if this is a `no_std` crate
- New ineffective_open_options had to be fixed.
- Now not raising an issue on missing `truncate` when `append(true)`
makes the intent clear.
- Try implementing more advanced tests for non-chained operations. Fail
Checks for the suspicious use of OpenOptions::create()
without an explicit OpenOptions::truncate().
create() alone will either create a new file or open an
existing file. If the file already exists, it will be
overwritten when written to, but the file will not be
truncated by default. If less data is written to the file
than it already contains, the remainder of the file will
remain unchanged, and the end of the file will contain old
data.
In most cases, one should either use `create_new` to ensure
the file is created from scratch, or ensure `truncate` is
called so that the truncation behaviour is explicit.
`truncate(true)` will ensure the file is entirely overwritten
with new data, whereas `truncate(false)` will explicitely
keep the default behavior.
```rust
use std::fs::OpenOptions;
OpenOptions::new().create(true).truncate(true);
```
The OpenTelemetry project's name is all one word (see https://opentelemetry.io),
so currently triggers a false positive in the `doc_markdown` lint.
The project is increasing rapidly in popularity, so it seems like a worthy
contender for inclusion in the default `doc_valid_idents` configuration.
I've also moved the existing "OpenDNS" entry earlier in the list, to restore
the alphabetical ordering of that "Open*" row.
The docs changes were generated using `cargo collect-metadata`.
changelog: [`doc_markdown`]: Add `OpenTelemetry` to the default configuration as an allowed identifier
[`useless_asref`]: check that the clone receiver is the parameter
Fixes#12135
There was no check for the receiver of the `clone` call in the map closure. This makes sure that it's a path to the parameter.
changelog: [`useless_asref`]: check that the clone receiver is the closure parameter
Make `HirEqInterExpr::eq_block` take comments into account while checking if two blocks are equal
This PR:
- now makes `HirEqInterExpr::eq_block` take comments into account. Identical code with varying comments will no longer be considered equal.
- makes necessary adjustments to UI tests.
Closes#12044
**Lintcheck Changes**
- `match_same_arms` 53 => 52
- `if_same_then_else` 3 => 0
changelog: [`if_same_then_else`]: Blocks with different comments will no longer trigger this lint.
changelog: [`match_same_arms`]: Arms with different comments will no longer trigger this lint.
```
There are cases where the closure call is needed in some macros, this in
particular occurs when the closure has parameters. To handle this case,
we allow the lint when there are no parameters in the closure, or the
closure is outside a macro invocation.
fixes: #11274, #1553
changelog: FP: [`redundant_closure_call`] when closures with parameters
are passed in macros.
Fix false positive in `PartialEq` check in `unconditional_recursion` lint
Fixes https://github.com/rust-lang/rust-clippy/issues/12133.
We needed to check for the type of the previous element <del>in case it's a field</del>.
EDIT: After some extra thoughts, no need to check if it's a field, just if it's the same type as `Self`.
r? `@llogiq`
changelog: Fix false positive in `PartialEq` check in `unconditional_recursion` lint
Fix suggestion for `map_clone` lint on types implementing `Copy`
Follow-up of https://github.com/rust-lang/rust-clippy/pull/12104.
It was missing this check to suggest the correct method.
r? `@llogiq`
changelog: Fix suggestion for `map_clone` lint on types implementing `Copy`
fix/issue#11243: allow 3-digit-grouped binary in non_octal_unix_permissions
fixes [Issue#11243](https://github.com/rust-lang/rust-clippy/issues/11243)
Issue#11243 suggest lint `non_octal_unix_permissions` should not report binary format literal unix permissions as an error, and we think binary format is a good way to understand these permissions.
To solve this problem, we need to add check for binary literal, which is written in function `check_binary_unix_permissions` , only `binary, 3 groups and each group length equals to 3` is a legal format.
changelog: [`non_octal_unix_permissions`]: Add check for binary format literal unix permissions like 0b111_111_111
Fixed ICE introduced in #12004
Issue: in https://github.com/rust-lang/rust-clippy/pull/12004, we emit a lint for `filter(Option::is_some)`. If the
parent expression is a `.map` we don't emit that lint as there exists a
more specialized lint for that.
The ICE introduced in https://github.com/rust-lang/rust-clippy/pull/12004 is a consequence of the assumption that a
parent expression after a filter would be a method call with the filter
call being the receiver. However, it is entirely possible to have a
closure of the form
```
|| { vec![Some(1), None].into_iter().filter(Option::is_some) }
```
The previous implementation looked at the parent expression; namely the
closure, and tried to check the parameters by indexing [0] on an empty
list.
This commit is an overhaul of the lint with significantly more FP tests
and checks.
Impl details:
1. We verify that the filter method we are in is a proper trait method
to avoid FPs.
2. We check that the parent expression is not a map by checking whether
it exists; if is a trait method; and then a method call.
3. We check that we don't have comments in the span.
4. We verify that we are in an Iterator of Option and Result.
5. We check the contents of the filter.
1. For closures we peel it. If it is not a single expression, we don't
lint. We then try again by checking the peeled expression.
2. For paths, we do a typecheck to avoid FPs for types that impl
functions with the same names.
3. For calls, we verify the type, via the path, and that the param of
the closure is the single argument to the call.
4. For method calls we verify that the receiver is the parameter of
the closure. Since we handle single, non-block exprs, the
parameter can't be shadowed, so no FP.
This commit also adds additional FP tests.
Fixes: #12058
Adding `@xFrednet` as you've the most context for this as you reviewed it last time.
`@rustbot` r? `@xFrednet`
---
changelog: none
(Will be backported and therefore don't effect stable)
Issue: in #12004, we emit a lint for `filter(Option::is_some)`. If the
parent expression is a `.map` we don't emit that lint as there exists a
more specialized lint for that.
The ICE introduced in #12004 is a consequence of the assumption that a
parent expression after a filter would be a method call with the filter
call being the receiver. However, it is entirely possible to have a
closure of the form
```
|| { vec![Some(1), None].into_iter().filter(Option::is_some) }
```
The previous implementation looked at the parent expression; namely the
closure, and tried to check the parameters by indexing [0] on an empty
list.
This commit is an overhaul of the lint with significantly more FP tests
and checks.
Impl details:
1. We verify that the filter method we are in is a proper trait method
to avoid FPs.
2. We check that the parent expression is not a map by checking whether
it exists; if is a trait method; and then a method call.
3. We check that we don't have comments in the span.
4. We verify that we are in an Iterator of Option and Result.
5. We check the contents of the filter.
1. For closures we peel it. If it is not a single expression, we don't
lint.
2. For paths, we do a typecheck to avoid FPs for types that impl
functions with the same names.
3. For calls, we verify the type, via the path, and that the param of
the closure is the single argument to the call.
4. For method calls we verify that the receiver is the parameter of
the closure. Since we handle single, non-block exprs, the
parameter can't be shadowed, so no FP.
This commit also adds additional FP tests.
Handle "calls" inside the closure as well in `map_clone` lint
Follow-up of https://github.com/rust-lang/rust-clippy/pull/12104.
I just realized that I didn't handle the case where the `clone` method was made as a call and not a method call.
r? `@llogiq`
changelog: Handle "calls" inside the closure as well in `map_clone` lint
improve [`cast_sign_loss`], to skip warning on always positive expressions
fixes: #11642
changelog: improve [`cast_sign_loss`] to skip warning on always positive expressions
Turns out this is change became quite big, and I still can't cover all the cases, like method calls such as `POSITIVE_NUM.mul(POSITIVE_NUM)`, or `NEGATIVE_NUM.div(NEGATIVE_NUM)`... but well, if I do, I'm scared that this will goes forever, so I stopped, unless it needs to be done, lol.
Do not suggest `[T; n]` instead of `vec![T; n]` if `T` is not `Copy`
changelog: [`useless_vec`]: do not suggest replacing `&vec![T; N]` by `&[T; N]` if `T` is not `Copy`
Fix#11958
Extend `map_clone` lint to also work on non-explicit closures
I found it weird that this case was not handled by the current line so I added it. The only thing is that I don't see an obvious way to infer the current type to determine if it's copyable or not, so for now I always suggest `cloned` and I added a FIXME.
r? `@llogiq`
changelog: Extend `map_clone` lint to also work on non-explicit closures
don't change eagerness for struct literal syntax with significant drop
Fixes the bug reported by `@ju1ius` in https://github.com/rust-lang/rust-clippy/issues/9427#issuecomment-1878428001.
`eager_or_lazy` already understands to suppress eagerness changes when the expression type has a significant drop impl, but only for initialization of tuple structs or unit structs. This changes it to also avoid changing it for `Self { .. }` and `TypeWithDrop { .. }`
changelog: [`unnecessary_lazy_eval`]: don't suggest changing eagerness for struct literal syntax when type has a significant drop impl
Hide foreign `#[doc(hidden)]` paths in import suggestions
Stops the compiler from suggesting to import foreign `#[doc(hidden)]` paths.
```@rustbot``` label A-suggestion-diagnostics
Don't emit `struct_field_names` lint if all fields are booleans and don't start with the type's name
Fixes#11936.
I only checked that all fields are booleans and not the prefix (nor the suffix) because when I started to list accepted prefixes (like "is", "has", "should", "could", etc), the list was starting to get a bit too long and I thought it was not really worth for such a small change.
r? `@llogiq`
changelog: Don't emit `struct_field_names` lint if all fields are booleans and don't start with the type's name
Don't lint `let_unit_value` when `()` is explicit
since these are explicitly written (and not the result of a function call or anything else), they should be allowed, as they are both useful in some cases described in #9048Fixes#9048
changelog: [`let_unit_value`]: Don't lint when `()` is explicit
Tweak suggestions for bare trait used as a type
```
error[E0782]: trait objects must include the `dyn` keyword
--> $DIR/not-on-bare-trait-2021.rs:11:11
|
LL | fn bar(x: Foo) -> Foo {
| ^^^
|
help: use a generic type parameter, constrained by the trait `Foo`
|
LL | fn bar<T: Foo>(x: T) -> Foo {
| ++++++++ ~
help: you can also use `impl Foo`, but users won't be able to specify the type paramer when calling the `fn`, having to rely exclusively on type inference
|
LL | fn bar(x: impl Foo) -> Foo {
| ++++
help: alternatively, use a trait object to accept any type that implements `Foo`, accessing its methods at runtime using dynamic dispatch
|
LL | fn bar(x: &dyn Foo) -> Foo {
| ++++
error[E0782]: trait objects must include the `dyn` keyword
--> $DIR/not-on-bare-trait-2021.rs:11:19
|
LL | fn bar(x: Foo) -> Foo {
| ^^^
|
help: use `impl Foo` to return an opaque type, as long as you return a single underlying type
|
LL | fn bar(x: Foo) -> impl Foo {
| ++++
help: alternatively, you can return an owned trait object
|
LL | fn bar(x: Foo) -> Box<dyn Foo> {
| +++++++ +
```
Fix#119525:
```
error[E0038]: the trait `Ord` cannot be made into an object
--> $DIR/bare-trait-dont-suggest-dyn.rs:3:33
|
LL | fn ord_prefer_dot(s: String) -> Ord {
| ^^^ `Ord` cannot be made into an object
|
note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
--> $SRC_DIR/core/src/cmp.rs:LL:COL
|
= note: the trait cannot be made into an object because it uses `Self` as a type parameter
::: $SRC_DIR/core/src/cmp.rs:LL:COL
|
= note: the trait cannot be made into an object because it uses `Self` as a type parameter
help: consider using an opaque type instead
|
LL | fn ord_prefer_dot(s: String) -> impl Ord {
| ++++
```
Don't look for safety comments in doc tests
Fixes#12048.
What happened in the linked issue is that the lint checks for lines that start with `//` and have `SAFETY:` somewhere in it above the function item.
This works for regular comments, but when the `//` is the start of a doc comment (e.g. `/// // SAFETY: ...`) and it's part of a doc test (i.e. within \`\`\`), we probably shouldn't lint that, since the user most likely meant to refer to a different node than the one currently being checked. For example in the linked issue, the safety comment refers to `unsafe { *five_pointer }`, but the lint believes it's part of the function item.
We also can't really easily test whether the `// SAFETY:` comment within a doc comment is necessary or not, since I think that would require creating a new compiler session to re-parse the contents of the doc comment. We already do this for one of the doc markdown lints, to look for a main function in doc tests, but I don't know how to feel about doing that in more places, so probably best to just ignore them?
changelog: [`unnecessary_safety_comment`]: don't look for safety comments in doc tests
Add .as_ref() to suggestion to remove .to_string()
The case of `.to_owned().split(…)` is treated specially in the `unnecessary_to_owned` lint. Test cases check that it works both for slices and for strings, but they missed a corner case: `x.to_string().split(…)` when `x` implements `AsRef<str>` but not `Deref<Target = str>`. In this case, it is wrong to suggest to remove `.to_string()` without adding `.as_ref()` instead.
Fix#12068
changelog: [`unnecessary_to_owned`]: suggest replacing `.to_string()` by `.as_ref()`
new lint: `option_as_ref_cloned`
Closes#12009
Adds a new lint that looks for `.as_ref().cloned()` on `Option`s. That's the same as just `.clone()`-ing the option directly.
changelog: new lint: [`option_as_ref_cloned`]
Extend `unconditional_recursion` lint to check for `Default` trait implementation
In case the `Default` trait is implemented manually and is calling a static method (let's call it `a`) and then `a` is using `Self::default()`, it makes an infinite call recursion difficult to see without debugging. This extension checks that there is no such recursion possible.
r? `@llogiq`
changelog: Extend `unconditional_recursion` lint to check for `Default` trait implementation
Lint nested binary operations and handle field projections in `eager_transmute`
This PR makes the lint a bit stronger. Previously it would only lint `(x < 4).then_some(transmute(x))` (that is, a single binary op in the condition). With this change, it understands:
- multiple, nested binary ops: `(x < 4 && x > 1).then_some(...)`
- local references with projections: `(x.field < 4 && x.field > 1).then_some(transmute(x.field))`
changelog: [`eager_transmute`]: lint nested binary operations and look through field/array accesses
r? llogiq (since you reviewed my initial PR #11981, I figured you have the most context here, sorry if you are too busy with other PRs, feel free to reassign to someone else then)
Fix false positive `unconditional_recursion`
Fixes#12052.
Only checking if both variables are `local` was not enough, we also need to confirm they have the same type as `Self`.
changelog: Fix false positive for `unconditional_recursion` lint
Fixes: #12050 - `identity_op` correctly suggests a deference for coerced references
When `identity_op` identifies a `no_op`, provides a suggestion, it also checks the type of the type of the variable. If the variable is a reference that's been coerced into a value, e.g.
```
let x = &0i32;
let _ = x + 0;
```
the suggestion will now use a derefence. This is done by identifying whether the variable is a reference to an integral value, and then whether it gets dereferenced.
changelog: false positive: [`identity_op`]: corrected suggestion for reference coerced to value.
fixes: #12050
This commit:
- now makes `HirEqInterExpr::eq_block` take comments into account. Identical code with varying comments will no longer be considered equal.
- makes necessary adjustments to UI tests.
Adds a new lint to suggest using `const` on `thread_local!`
initializers that can be evaluated at compile time.
Impl details:
The lint relies on the expansion of `thread_local!`. For non
const-labelled initializers, `thread_local!` produces a function
called `__init` that lazily initializes the value. We check the function
and decide whether the body can be const. The body of the function is
exactly the initializer. If so, we lint the body.
changelog: new lint [`thread_local_initializer_can_be_made_const`]
Extend UNCONDITIONAL_RECURSION to check for ToString implementations
Follow-up of https://github.com/rust-lang/rust-clippy/pull/11938.
r? `@llogiq`
changelog: Extend `UNCONDITIONAL_RECURSION` to check for `ToString` implementations
New Lint: empty_enum_variants_with_brackets
This PR:
- adds a new early pass lint that checks for enum variants with no fields that were defined using brackets. **Category: Restriction**
- adds relevant UI tests for the new lint.
Closes#12007
```
changelog: New lint: [`empty_enum_variants_with_brackets`]
```
don't lint [`default_numeric_fallback`] on return and local assigned macro calls with type stated
fixes: #11535
changelog: don't lint [`default_numeric_fallback`] on return and local assigned macro calls with type stated
feat: add `manual_is_variant_and` lint
changelog: add a new lint [`manual_is_variant_and`].
- Replace `option.map(f).unwrap_or_default()` and `result.map(f).unwrap_or_default()` with `option.is_some_and(f)` and `result.is_ok_and(f)` where `f` is a function or closure that returns `bool`.
- MSRV is set to 1.70.0 for this lint; when `is_some_and` and `is_ok_and` was stabilised
---
For example, for the following code:
```rust
let opt = Some(0);
opt.map(|x| x > 1).unwrap_or_default();
```
It suggests to instead write:
```rust
let opt = Some(0);
opt.is_some_and(|x| x > 1)
```
make [`mutex_atomic`] more type aware
fixes: #9872
---
changelog: [`mutex_atomic`] now suggests more specific atomic types and skips mutex i128 and u128
When `identity_op` identifies a `no_op`, provides a suggestion, it also
checks the type of the type of the variable. If the variable is
a reference that's been coerced into a value, e.g.
```
let x = &0i32;
let _ = x + 0;
```
the suggestion will now use a derefence. This is done by identifying
whether the variable is a reference to an integral value, and then
whether it gets dereferenced.
changelog: false positive: [`identity_op`]: corrected suggestion for
reference coerced to value.
fixes: #12050
feature: add new lint `pub_underscore_fields`
fixes: #10282
This PR introduces a new lint `pub_underscore_fields` that lints when a user has marked a field of a struct as public, but also prefixed it with an underscore (`_`). This is something users should avoid because the two ideas are contradictory. Prefixing a field with an `_` is inferred as the field being unused, but making a field public infers that it will be used.
- \[x] Followed [lint naming conventions][lint_naming]
- I believe I followed the naming conventions, more than happy to update the naming if I did not :)
- \[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`
---
changelog: new lint: [`pub_underscore_fields`]
[#10283](https://github.com/rust-lang/rust-clippy/pull/10283)
<!-- changelog_checked -->
- add a new late pass lint, with config options
- add ui tests for both variations of config option
- update CHANGELOG.md
github feedback
bump version to 1.77 and run cargo collect-metadata
Change `,` to `;` in `conf.rs`
new lint: `eager_transmute`
A small but still hopefully useful lint that looks for patterns such as `(x < 5).then_some(transmute(x))`.
This is almost certainly wrong because it evaluates the transmute eagerly and can lead to surprises such as the check being completely removed and always evaluating to `Some` no matter what `x` is (it is UB after all when the integer is not a valid bitpattern for the transmuted-to type). [Example](https://godbolt.org/z/xoY34fPzh).
The user most likely meant to use `then` instead.
I can't remember where I saw this but this is inspired by a real bug that happened in practice.
This could probably be a correctness lint?
changelog: new lint: [`eager_int_transmute`]
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.
Make some non-diagnostic-affecting `QPath::LangItem` into regular `QPath`s
The rest of 'em affect diagnostics, so leave them alone... for now.
cc #115178
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...
