[`needless_doctest_main`]: ignore `main()` in `no_test` code fences
close#10491
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`needless_doctest_main`]: ignore `main()` in `no_test` code fence
[`map_unwrap_or`]: don't lint when referenced variable is moved
Fixes#10579.
The previous way of checking if changing `map(f).unwrap_or(a)` to `map_or(a, f)` is safe had a flaw when the argument to `unwrap_or` moves a binding and the `map` closure references that binding in some way.
It used to simply check if any of the identifiers in the `unwrap_or` argument are referenced in the `map` closure, but it didn't consider the case where the moved binding is referred to through references, for example:
```rs
let x = vec![1, 2];
let x_ref = &x;
Some(()).map(|_| x_ref.clone()).unwrap_or(x);
```
This compiles as is, but we cannot change it to `map_or`. This lint however did suggest changing it, because the simple way of checking if `x` is referenced anywhere in the `map` closure fails here. The safest thing to do here imo (what this PR does) is check if the moved value `x` is referenced *anywhere* in the body (before the `unwrap_or` call). One can always create a reference to the value and smuggle them into the closure, without actually referring to `x`. The original, linked issue shows another one such example:
```rs
let x = vec![1,2,3,0];
let y = x.strip_suffix(&[0]).map(|s| s.to_vec()).unwrap_or(x);
```
`x.strip_suffix(&[0])` creates a reference to `x` that is available through `s` inside of the `map` closure, so we can't change it to `map_or`.
changelog: [`map_unwrap_or`]: don't lint when referenced variable is moved
[`no_effect`]: Suggest adding `return` if applicable
Closes#10941
Unfortunately doesn't catch anything complex as `no_effect` already wouldn't, but I'm fine with that (it catches `ControlFlow` at least :D)
changelog: [`no_effect`]: Suggest adding `return` if statement has same type as function's return type and is the last statement in a block
[`useless_vec`]: lint on `vec![_]` invocations that adjust to a slice
Fixes#2262 (well, actually my PR over at #10901 did do most of the stuff, but this PR implements the one last other case mentioned in the comments that my PR didn't fix)
Before this change, it would lint `(&vec![1]).iter().sum::<i32>()`, but not `vec![1].iter().sum::<i32>()`. This PR handles this case.
This also refactors a few things that I wanted to do in my other PR but forgot about.
changelog: [`useless_vec`]: lint on `vec![_]` invocations that adjust to a slice
Don't linting `as_conversions` in proc macros
Don't linting `as_conversions` if code was generated by procedural macro.
This PR fixes https://github.com/rust-lang/rust-clippy/issues/9657
I implemented the fix changing the lint code to be a `LateLintPass` in order to be able to use the `is_from_proc_macro` out of the box. If the reviwer thinks that it would be better to do the other way (implementing `WithSearchPat`) just let me know. I might need some help in implementing it for the `ustc_ast::ast::Expr`
changelog: [`as_conversions`] avoiding warnings in macro-generated code
Extend `explicit_iter_loop` and `explicit_into_iter_loop`
fixes#1518
Some included cleanups
* Split `for_loop` test into different files for each lint (partially).
* Move handling of some `into_iter` cases from `explicit_into_iter`.
---
changelog: Enhancement: [`explicit_iter_loop`]: Now also handles types that implement `IntoIterator`.
[#10416](https://github.com/rust-lang/rust-clippy/pull/10416)
changelog: Sugg: [`explicit_into_iter_loop`]: The suggestion now works on mutable references.
[#10416](https://github.com/rust-lang/rust-clippy/pull/10416)
<!-- changelog_checked -->
Add `needless_if` lint
first off: Sorry about the large diff. Seems a ton of tests do this (understandably so).
this is basically everything I wanted in #10868, while it doesn't lint *all* unnecessary empty blocks, it lints needless if statements; which are basically the crux of the issue (for me) anyway. I've committed code that includes this far too many times 😅 hopefully clippy can help me out soon
closes#10868
changelog: New lint [`needless_if`]
Fix `diverging_sub_expression` not checking body of block
Fixes#10776
This also adds a warning to the test `ui/never_loop.rs`, not sure if this is correct or not.
changelog: [`diverging_sub_expression`]: Fix false negatives with body of block
Uplift `clippy::undropped_manually_drops` lint
This PR aims at uplifting the `clippy::undropped_manually_drops` lint.
## `undropped_manually_drops`
(warn-by-default)
The `undropped_manually_drops` lint check for calls to `std::mem::drop` with a value of `std::mem::ManuallyDrop` which doesn't drop.
### Example
```rust
struct S;
drop(std::mem::ManuallyDrop::new(S));
```
### Explanation
`ManuallyDrop` does not drop it's inner value so calling `std::mem::drop` will not drop the inner value of the `ManuallyDrop` either.
-----
Mostly followed the instructions for uplifting an clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
`@rustbot` label: +I-lang-nominated
r? compiler
-----
For Clippy:
changelog: Moves: Uplifted `clippy::undropped_manually_drops` into rustc
[`unnecessary_to_owned`]: check that the adjusted type matches target
Fixes#10033.
Before this change, the lint would assume that removing the `.to_string()` in `f(&x.to_string())` would be ok if x is of some type that implements `Deref<Target = str>` and `f` takes a `&str`.
This turns out to not actually be ok if the `to_string` call is some method that exists on `x` directly, which happens if it implements `Display`/`ToString` itself.
changelog: [`unnecessary_to_owned`]: only lint if the adjusted receiver type actually matches
Ignore more pointer types in `unnecessary_cast`
Spotted this because
e2c655b4c0/tests/ui/suspicious_to_owned.rs (L9-L10)
currently fails on `aarch64-unknown-linux-gnu` as `c_char` is `u8` there
The current implementation checks for `as alias`, `as _`. This adds things like
- `as *const alias`
- `as *const cfg_dependant`
- `as *const _`
changelog: none
[`redundant_closure`]: special case inclusive ranges
Fixes#10684.
`x..=y` ranges need a bit of special handling in this lint because it desugars to a call to the lang item `RangeInclusiveNew`, where the callee span would be the same as the range expression itself, so the suggestion looked a bit weird. It now correctly suggests `RangeInclusive::new`.
changelog: [`redundant_closure`]: special case `RangeInclusive`
Adds new lint `arc_with_non_send_or_sync`
Fixes#653
Adds a new lint to check for uses of non-Send/Sync types within Arc.
```
changelog: [`arc_with_non_send_sync`]: Added a lint to detect uses of non-Send/Sync types within Arc.
```
[`useless_vec`]: lint `vec!` invocations when a slice or an array would do
First off, sorry for that large diff in tests. *A lot* of tests seem to trigger the lint with this new change, so I decided to `#![allow()]` the lint in the affected tests to make reviewing this easier, and also split the commits up so that the first commit is the actual logic of the lint and the second commit contains all the test changes. The stuff that changed in the tests is mostly just line numbers now. So, as large as the diff looks, it's not actually that bad. 😅
I manually went through all of these to find out about edge cases and decided to put them in `tests/ui/vec.rs`.
For more context, I wrote about the idea of this PR here: https://github.com/rust-lang/rust-clippy/issues/2262#issuecomment-1579155257 (that explains the logic)
Basically, it now also considers the case where a `Vec` is put in a local variable and the user only ever does things with it that one could also do with a slice or an array. This should catch a lot more cases, and (at least from looking at the tests) it does.
changelog: [`useless_vec`]: lint `vec!` invocations when a slice or an array would do (also considering local variables now)
`suspicious_else_formatting`: Don't warn if there is a comment between else and curly bracket
This PR fixes https://github.com/rust-lang/rust-clippy/issues/10273
The idea is that if the only thing after `else` and before `{` is a comment, we will not warn because, probably, the line break was "made" by rustfmt.
changelog: [`suspicious_else_formatting`]: Don't warn if the only thing between `else` and curly bracket is a comment
[`missing_fields_in_debug`]: don't ICE when self type is a generic param
Fixes#10887
This PR fixes an ICE that happens when the implementor (self type) of a `Debug` impl is a generic parameter.
The lint calls `TyCtxt::type_of` with that self type, which ICEs when called with generic parameters, so this just adds a quick check before getting there to ignore them.
That can only happen inside of core itself (afaik) because the orphan rules forbid defining an impl such as `impl<T> Debug for T` outside of core, so I'm not sure how to add a test for this.
It seems like this impl in particular caused this: https://doc.rust-lang.org/stable/std/fmt/trait.Debug.html#impl-Debug-for-F
changelog: [`missing_fields_in_debug`]: don't ICE on blanket `Debug` impl in core
[`let_with_type_underscore`]: Don't emit on locals from procedural macros
closes#10498
changelog: [`let_with_type_underscore`]: Don't emit on locals from procedural macros
make cast_possible_wrap work correctly for 16 bit {u,i}size
These changes make `cast_possible_wrap` aware of the different pointer widths and fixes the implementation to print the correct pointer widths.
Fixes#9337
changelog: `cast_possible_wrap` does not lint on `u8 as isize` or `usize as i8`, since these can never wrap.
`cast_possible_wrap` now properly considers 16 bit pointer size and prints the correct bit widths.
Add redundant type annotations lint
Hello, I'm trying to add the `redundat_type_annotations` lint.
It's still WIP but I'd like to start gathering some feedbacks to be sure that I'm not doing things 100% wrong :)
Right now it still misses lints like:
- [x] `let foo: u32 = 5_u32`,
- [x] `let foo: String = STest2::func()`
- [x] `let foo: String = self.func()` (`MethodCall`)
- [x] refs
- [ ] Generics
I've some problems regarding the second example above, in the `init` part of the `Local` I have:
```rust
init: Some(
Expr {
hir_id: HirId(DefId(0:24 ~ playground[e1bd]::main).58),
kind: Call(
Expr {
hir_id: HirId(DefId(0:24 ~ playground[e1bd]::main).59),
kind: Path(
TypeRelative(
Ty {
hir_id: HirId(DefId(0:24 ~ playground[e1bd]::main).61),
kind: Path(
Resolved(
None,
Path {
span: src/main.rs:77:21: 77:27 (#0),
res: Def(
Struct,
DefId(0:17 ~ playground[e1bd]::STest2),
),
segments: [
PathSegment {
ident: STest2#0,
hir_id: HirId(DefId(0:24 ~ playground[e1bd]::main).60),
res: Def(
Struct,
DefId(0:17 ~ playground[e1bd]::STest2),
),
args: None,
infer_args: true,
},
],
},
),
),
span: src/main.rs:77:21: 77:27 (#0),
},
PathSegment {
ident: get_numb#0,
hir_id: HirId(DefId(0:24 ~ playground[e1bd]::main).62),
res: Err,
args: None,
infer_args: true,
},
),
),
span: src/main.rs:77:21: 77:37 (#0),
},
[],
),
span: src/main.rs:77:21: 77:39 (#0),
},
),
```
And I'm not sure how to get the return type of the function `STest2::func()` since the resolved path `DefId` points to the struct itself and not the function. Do you have any idea on how I could get this information in this case?
Thanks!
changelog: changelog: [`redundant_type_annotations`]: New lint to warn on redundant type annotations
fixes#9155
Bring up Rust lang #37612 as a known problem for let_and_return
Fixes https://github.com/rust-lang/rust-clippy/issues/4182.
I don't think conforming to this lint could trigger the issue immediately, only if subsequent code-changes go wrong, but I may be mistaken.
Since the lint can't trigger it by itself, just closing this issue might be reasonable, if not maybe this PR fixes it.
changelog: Update docs for `let_and_return`, mention rust-lang #37612
Add lints for disallowing usage of `to_xx_bytes` and `from_xx_bytes`
Adds `host_endian_bytes`, `little_endian_bytes` and `big_endian_bytes`
Closes#10765
v - not sure what to put here since this adds 3 lints
changelog: Add `host_endian_bytes`, `little_endian_bytes` and `big_endian_bytes` lints
[`allow_attributes`, `allow_attributes_without_reason`]: Ignore attributes from procedural macros
I use `lint_reasons` and `clap`, which is a bit overzealous when it comes to preventing warnings in its macros; it uses a ton of allow attributes on everything to, as ironic as it is, silence warnings. These two now ignore anything from procedural macros.
PS, I think `allow_attributes.rs` should be merged with `attrs.rs` in the future.
fixes#10377
changelog: [`allow_attributes`, `allow_attributes_without_reason`]: Ignore attributes from procedural macros
Ignore fix for `from_over_into` if the target type contains a `Self` reference
Fixes https://github.com/rust-lang/rust-clippy/issues/10838.
This is my first time contributing here, and the fix is kind of ugly.
I've worked a bit with `quote` and was trying to figure out a way to replace the type in a better way than just a raw string-replace but couldn't quite figure out how to.
The only thing really required to fix this, is to replace all `Self` references with the type stated in the `from` variable, this isn't entirely simple to do with raw strings without creating a mess though.
We need to find and replace all `Self`'s in a variable with `from` but there could be an arbitrary amount, in a lot of different positions. As well as some type that contains the name self, like `SelfVarSelf` which shouldn't be replaced.
The strategy is essentially, if `"Self"` is surrounded on both sides by something that isn't alphanumeric, then we're golden, then trying to make that reasonably efficient.
I would not be offended if the solution is too messy to accept!
changelog: [from_over_into]: Replace Self with the indicated variable in suggestion and fix.
new lint: `explicit_into_iter_fn_arg`
Closes#10743.
This adds a lint that looks for `.into_iter()` calls in a call expression to a function that already expects an `IntoIterator`. In those cases, explicitly calling `.into_iter()` is unnecessary.
There were a few instances of this in clippy itself so I fixed those as well in this PR.
changelog: new lint [`explicit_into_iter_fn_arg`]
manual_let_else: support struct patterns
This adds upon the improvements of #10797 and:
* Only prints `()` around `Or` patterns at the top level (fixing a regression of #10797)
* Supports multi-binding patterns: `let (u, v) = if let (Some(u_i), Ok(v_i)) = ex { (u_i, v_i) } else ...`
* Traverses through tuple patterns: `let v = if let (Some(v), None) = ex { v } else ...`
* Supports struct patterns: `let v = if let S { v, w, } = ex { (v, w) } else ...`
```
changelog: [`manual_let_else`]: improve pattern printing to support struct patterns
```
fixes#10708fixes#10424
[`ptr_cast_constness`]: Only lint on casts which don't change type
fixes#10874
changelog: [`ptr_cast_constness`]: Only lint on casts which don't change type
Emit `unnecessary_cast` on raw pointers as well
Supersedes(?) #10782, since this and #10567 will cover the original issue.
Does not lint on type aliases or inferred types.
changelog: [`unnecessary_cast`]: Also emit on casts between raw pointers with the same type and constness
Clippy Book Chapter Updates Reborn: Refresh Lint Configuration's looks
This PR modernizes and clears up some confusion with the "Lint Configuration Options" chapter from the book.
### Changes
- **Remove 'Option - Default Value" table**
- Why was it even there?
- It shouldn't be the first thing an user sees when they enter the chapter. It's clunky, ugly and not useful. The default values for configs are stated in a per-config basis if needed.
- **Add a simple description of what the chapter contains, and the scheme of each configuration option**
- **Minor formatting, mainly adding code fragments to code text**
- It seemed weird and jarring not having back-ticks on text like "arithmetic_side_effects".
- Improves readability and separation between configs.
- **Separate a little bit the Affected Lints list + "Affected lists" message**
- Not having something indicating that the list is about the lints that use the configuration option is confusing.
- It isn't as important as the description and example. Therefore should be separated a little bit imo
---
This is an independent effort from #10597, but as it's still a Book Chapter Update, I thought it would be cool to include it here. I'm going to keep the reviewing process for this PR to rustbot's desires.
[Rendered](https://github.com/blyxyas/rust-clippy/blob/book-lint_config/book/src/lint_configuration.md)
[Current](https://github.com/rust-lang/rust-clippy/blob/master/book/src/lint_configuration.md)
changelog: Refresh styling from the "Lint Configuration Options" book chapter.
add checking for cfg(features = ...)
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`maybe_misused_cfg`]: check if `#[cfg(feature = "...")]` misused as `#[cfg(features = "...")]`
I've found that there is no indication when `#[cfg(features = "...")]` is used incorrectly, which can easily make mistakes hard to spot. When I searched for this code on github, I also found many misuse cases([link](https://github.com/search?q=%23%5Bcfg%28features+language%3ARust&type=code)).
PS: This clippy name is just a temporary name, it can be replaced with a better name.
Add spans to `clippy.toml` error messages
Adds spans to errors and warnings encountered when parsing `clippy.toml`.
changelog: Errors and warnings generated when parsing `clippy.toml` now point to the location in the TOML file the error/warning occurred.
move some strings into consts, more tests
s/missing_field_in_debug/missing_fields_in_debug
dont trigger in macro expansions
make dogfood tests happy
minor cleanups
replace HashSet with FxHashSet
replace match_def_path with match_type
if_chain -> let chains, fix markdown, allow newtype pattern
fmt
consider string literal in `.field()` calls as used
don't intern defined symbol, remove mentions of 'debug_tuple'
special-case PD, account for field access through `Deref`
`EarlyBinder::new` -> `EarlyBinder::bind`
for consistency with `Binder::bind`. it may make sense to also add `EarlyBinder::dummy` in places where we know that no parameters exist, but I left that out of this PR.
r? `@jackh726` `@kylematsuda`
Uplift `clippy::invalid_utf8_in_unchecked` lint
This PR aims at uplifting the `clippy::invalid_utf8_in_unchecked` lint into two lints.
## `invalid_from_utf8_unchecked`
(deny-by-default)
The `invalid_from_utf8_unchecked` lint checks for calls to `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut` with an invalid UTF-8 literal.
### Example
```rust
unsafe {
std::str::from_utf8_unchecked(b"cl\x82ippy");
}
```
### Explanation
Creating such a `str` would result in undefined behavior as per documentation for `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut`.
## `invalid_from_utf8`
(warn-by-default)
The `invalid_from_utf8` lint checks for calls to `std::str::from_utf8` and `std::str::from_utf8_mut` with an invalid UTF-8 literal.
### Example
```rust
std::str::from_utf8(b"ru\x82st");
```
### Explanation
Trying to create such a `str` would always return an error as per documentation for `std::str::from_utf8` and `std::str::from_utf8_mut`.
-----
Mostly followed the instructions for uplifting a clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
````@rustbot```` label: +I-lang-nominated
r? compiler
-----
For Clippy:
changelog: Moves: Uplifted `clippy::invalid_utf8_in_unchecked` into rustc
deps: drop serde feature from url, drop rustc-workspace-hack
Cargo now have it's own workspace and rustc dropped [`rustc-workspace-hack`](https://github.com/rust-lang/rust/pull/109133), so no need to unify features here; drop rustc-workspace-hack.
changelog: none
Each of `{D,Subd}iagnosticMessage::{Str,Eager}` has a comment:
```
// FIXME(davidtwco): can a `Cow<'static, str>` be used here?
```
This commit answers that question in the affirmative. It's not the most
compelling change ever, but it might be worth merging.
This requires changing the `impl<'a> From<&'a str>` impls to `impl
From<&'static str>`, which involves a bunch of knock-on changes that
require/result in call sites being a little more precise about exactly
what kind of string they use to create errors, and not just `&str`. This
will result in fewer unnecessary allocations, though this will not have
any notable perf effects given that these are error paths.
Note that I was lazy within Clippy, using `to_string` in a few places to
preserve the existing string imprecision. I could have used `impl
Into<{D,Subd}iagnosticMessage>` in various places as is done in the
compiler, but that would have required changes to *many* call sites
(mostly changing `&format("...")` to `format!("...")`) which didn't seem
worthwhile.
Improve pattern printing for manual_let_else
* Address a formatting issue pointed out in https://github.com/rust-lang/rust-clippy/pull/10175/files#r1137091002
* Replace variables inside | patterns in the if let: `let v = if let V::A(v) | V::B(v) = v { v } else ...`
* Support nested patterns: `let v = if let Ok(Ok(Ok(v))) = v { v } else ...`
* Support tuple structs with more than one arg: `let v = V::W(v, _) = v { v } else ...`; note that more than one *capture* is still not supported, so it bails for `let (v, w) = if let E::F(vi, wi) = x { (vi, wi)}`
* Correctly handle .. in tuple struct patterns: `let v = V::X(v, ..) = v { v } else ...`
- \[ ] Followed [lint naming conventions][lint_naming]
- \[x] Added passing UI tests (including committed `.stderr` file)
- \[x] `cargo test` passes locally
- \[ ] Executed `cargo dev update_lints`
- \[ ] Added lint documentation
- \[x] Run `cargo dev fmt`
[lint_naming]: https://rust-lang.github.io/rfcs/0344-conventions-galore.html#lints
---
changelog: [`manual_let_else`]: improve variable name in suggestions
Closes#10431 as this PR is adding a test for the `mut` case.
Ignore `#[cfg]`'d out code in `needless_else`
changelog: none (same release as #10810)
`#[cfg]` making things fun once more
This lead me to think about macro calls that expand to nothing as well, but apparently they produce an empty stmt in the AST so are already handled, added a test for that
r? `@llogiq`
[`default_constructed_unit_structs`]: do not lint on type alias paths
Fixes#10755.
Type aliases cannot be used as a constructor, so this lint should not trigger in those cases.
I also changed `clippy_utils::is_ty_alias` to also consider associated types since [they kinda are type aliases too](48ec50ae39/compiler/rustc_resolve/src/late/diagnostics.rs (L1520)).
changelog: [`default_constructed_unit_structs`]: do not lint on type alias paths
[`unused_async`]: do not consider `await` in nested `async` blocks as used
Fixes#10800.
This PR makes sure that `await` expressions inside of inner `async` blocks don't prevent the lint from triggering.
For example
```rs
async fn foo() {
async {
std::future::ready(()).await;
}
}
```
Even though there *is* a `.await` expression in this function, it's contained in an async block, which means that the enclosing function doesn't need to be `async` too.
changelog: [`unused_async`]: do not consider `await` in nested `async` blocks as used
Add new lint `ptr_cast_constness`
This adds a new lint which functions as the opposite side of the coin to `ptr_as_ptr`. Rather than linting only as casts that don't change constness, this lints only constness; suggesting to use `pointer::cast_const` or `pointer::cast_mut` instead.
changelog: new lint [`ptr_cast_constness`]
needless_else: new lint to check for empty `else` clauses
Empty `else` clauses are useless. They happen in the wild and are not linted yet: https://github.com/uutils/coreutils/pull/4880/files
`else` clauses containing or preceded by comments are not linted as the comments might be important.
changelog: [`needless_else`]: new lint
[`large_stack_arrays`]: check array initializer expressions
Fixes#10741.
Prior to this PR, the lint only checked array repeat expressions (ie. `[T; n]`). Now it also checks array initializer expressions.
changelog: [`large_stack_arrays`]: check array initializer expressions
Enhance `needless_collect`: lint in method/function arguments that take an `IntoIterator`
Updates `needless_collect` to also lint `collect` calls in method/function arguments that take an `IntoIterator` (for example `Extend::extend`). Every `Iterator` trivially implements `IntoIterator` and collecting it only causes an unnecessary allocation.
---
changelog: Enhancement: [`needless_collect`]: Now also detects function arguments, taking a generic `IntoIterator`
[#10777](https://github.com/rust-lang/rust-clippy/pull/10777)
<!-- changelog_checked -->
fixes#10762
* Replace variables inside | patterns in the if let: let v = if let V::A(v) | V::B(v) = v { v } else ...
* Support nested patterns: let v = if let Ok(Ok(Ok(v))) = v { v } else ...
* Support tuple structs with more than one arg: let v = V::W(v, _) = v { v } else ...
* Correctly handle .. in tuple struct patterns: let v = V::X(v, ..) = v { v } else ...
Rename `integer_arithmetic`
The lack of official feedback in #10200 made me give up on pursuing the matter but after yet another use-case that is not handled by `integer_arithmetic` (#10615), I think it is worth trying again.
---
changelog: Move/Deprecation: Rename `integer_arithmetic` to `arithmetic_side_effects`
[#10674](https://github.com/rust-lang/rust-clippy/pull/10674)
<!-- changelog_checked -->
don't remove `dbg!` in arbitrary expressions
Fixes#9914
The `dbg_macro` lint replaces empty `dbg!` invocations with the empty string in its suggestion, which is not always valid code in certain contexts (e.g. `let _ = dbg!();` becomes `let _ = ;`). This PR changes it to `()`, which should always be valid where `dbg!()` is valid (`dbg!()` with no arguments evaluates to `()`).
It also special-cases "standalone" `dbg!();` expression statements, where it will suggest removing the whole statement entirely like it did before.
changelog: [`dbg_macro`]: don't remove `dbg!()` in arbitrary expressions as it sometimes results in syntax errors
Remove unnecessary `clone` from `needless_collect` example
The example for [clippy::needless_collect](https://rust-lang.github.io/rust-clippy/master/#needless_collect) is written as follows:
```rust
let len = iterator.clone().collect::<Vec<_>>().len();
// should be
let len = iterator.count();
```
With this change, the unnecessary `clone()` is removed and the the standard
### Example
```rust
// original
```
Use instead:
```rust
// improved
```
structure is followed.
Discussion: https://github.com/rust-lang/rust-clippy/discussions/10784#discussion-5198885
changelog: [`needless_collect`]: Cleaned up the example in the lint documentation.
fix [`invalid_regex`] not recognizing new syntax introduced after regex-1.8.0
fixes: #10680
---
changelog: fix [`invalid_regex`] not recognizing new syntax introduced after regex-1.8.0
bump up `regex-syntax` dependency version to 0.7.0
Fix: Some suggestions generated by the option_if_let_else lint did not compile
This addresses a bug in Clippy where the fix suggestend by the `option_if_let_else` lint would not compile for `Result`s which have an impure expression in the `else` branch.
---
changelog: [`option_if_let_else`]: Fixed incorrect suggestion for `Result`s
[#10337](https://github.com/rust-lang/rust-clippy/pull/10337)
<!-- changelog_checked -->
Fixes#10335.
Updates `needless_collect` to lint for collecting into a method or
function argument thats taking an `IntoIterator` (for example `extend`).
Every `Iterator` trivially implements `IntoIterator` and colleting it
only causes an unnecessary allocation.
[arithmetic_side_effects] Consider referenced allowed or hard-coded types
Fix#10767
```
changelog: [`arithmetic_side_effects`]: Do not fire when dealing with allowed or hard-coded types that are referenced.
```
fix: warn on empty line outer AttrKind::DocComment
changelog: [`empty_line_after_doc_comments`]: add lint for checking empty lines after rustdoc comments.
Fixes: #10395
Add configuration options to `--explain`
This PR rearranges some modules, taking `metadata_collector` out of `internal_lints` and making public just the necessary functions for `explain()` to use.
The output looks something like this:
```sh
$ cargo run --bin cargo-clippy --manifest-path ../rust-clippy/Cargo.toml -- --explain cognitive_complexity
### What it does
Checks for methods with high cognitive complexity.
### Why is this bad?
Methods of high cognitive complexity tend to be hard to
both read and maintain. Also LLVM will tend to optimize small methods better.
### Known problems
Sometimes it's hard to find a way to reduce the
complexity.
### Example
You'll see it when you get the warning.
========================================
Configuration for clippy::cognitive_complexity:
- cognitive-complexity-threshold: The maximum cognitive complexity a function can have (default: 25)
```
Fixes#9990
r? `@xFrednet`
---
changelog: Docs: `cargo clippy --explain LINT` now shows possible configuration options for the explained lint
[#10751](https://github.com/rust-lang/rust-clippy/pull/10751)
<!-- changelog_checked -->
Extend `trait_duplication_in_bounds` to cover trait objects
This PR extends `trait_duplication_in_bounds` to cover trait objects.
Currently,
```rs
fn foo(_a: &(dyn Any + Send + Send)) {}
```
generates no warnings. With this PR, it will complain about a duplicate trait and can remove it
Moved from rust-lang/rust#110991
changelog: [`trait_duplication_in_bounds`]: warn on duplicate trait object constraints
fix: `wildcard_imports` ignore `test.rs` files
Adds a check to see if the building crate is a test one, if so, ignore it
---
Closes#10580
changelog:[`wildcard_imports`]: Add a check to ignore files named `test.rs` and `tests.rs`
Introduce `AliasKind::Inherent` for inherent associated types
Allows us to check (possibly generic) inherent associated types for well-formedness.
Type inference now also works properly.
Follow-up to #105961. Supersedes #108430.
Fixes#106722.
Fixes#108957.
Fixes#109768.
Fixes#109789.
Fixes#109790.
~Not to be merged before #108860 (`AliasKind::Weak`).~
CC `@jackh726`
r? `@compiler-errors`
`@rustbot` label T-types F-inherent_associated_types
Ignore `borrow_deref_ref` warnings in code from procedural macros.
Don't linting `borrow_deref_ref` if code was generated by procedural macro.
This PR fixes https://github.com/rust-lang/rust-clippy/issues/8971
changelog: [`borrow_deref_ref`] avoiding warnings in macro-generated code
Fixes#10609: Adds lint to detect construction of unit struct using `default`
Using `default` to construct a unit struct increases code complexity and adds a function call. This can be avoided by simply removing the call to `default` and simply construct by name.
changelog: [`default_constructed_unit_structs`]: detects construction of unit structs using `default`
fixes#10609
Currently a `{D,Subd}iagnosticMessage` can be created from any type that
impls `Into<String>`. That includes `&str`, `String`, and `Cow<'static,
str>`, which are reasonable. It also includes `&String`, which is pretty
weird, and results in many places making unnecessary allocations for
patterns like this:
```
self.fatal(&format!(...))
```
This creates a string with `format!`, takes a reference, passes the
reference to `fatal`, which does an `into()`, which clones the
reference, doing a second allocation. Two allocations for a single
string, bleh.
This commit changes the `From` impls so that you can only create a
`{D,Subd}iagnosticMessage` from `&str`, `String`, or `Cow<'static,
str>`. This requires changing all the places that currently create one
from a `&String`. Most of these are of the `&format!(...)` form
described above; each one removes an unnecessary static `&`, plus an
allocation when executed. There are also a few places where the existing
use of `&String` was more reasonable; these now just use `clone()` at
the call site.
As well as making the code nicer and more efficient, this is a step
towards possibly using `Cow<'static, str>` in
`{D,Subd}iagnosticMessage::{Str,Eager}`. That would require changing
the `From<&'a str>` impls to `From<&'static str>`, which is doable, but
I'm not yet sure if it's worthwhile.
Fix `items_after_test_module`: Ignore imported modules
Fixes#10713. It does a little bit of dark magic, but intention is what really counts.
changelog:[`items_after_test_module`]: Ignore imported modules (`mod foo;`) with no body.
Using `default` to construct a unit struct increases code complexity and
adds a function call. This can be avoided by simply removing the call to
`default` and simply construct by name.
Add configuration for `semicolon_block` lints
Does exactly what it says on the tin, suggests moving a block's final semicolon inside if it's multiline and outside if it's singleline.
I don't really like how this is implemented so I'm not too sure if this is ready yet. Alas, it might be ok.
---
fixes#10654
changelog: Enhancement: [`semicolon_inside_block`]: Added `semicolon-inside-block-ignore-singleline` as a new config value.
[#10656](https://github.com/rust-lang/rust-clippy/pull/10656)
changelog: Enhancement: [`semicolon_outside_block`]: Added `semicolon-outside-block-ignore-multiline` as a new config value.
[#10656](https://github.com/rust-lang/rust-clippy/pull/10656)
<!-- changelog_checked -->
Switch to `EarlyBinder` for `explicit_item_bounds`
Part of the work to finish https://github.com/rust-lang/rust/issues/105779.
This PR adds `EarlyBinder` to the return type of the `explicit_item_bounds` query and removes `bound_explicit_item_bounds`.
r? `@compiler-errors` (hope it's okay to request you, since you reviewed #110299 and #110498😃)
Improve the help message + add a help span
This would close#10410, because it applies the general consensus achieved in that issue (that replacing `let _ = ...` to `_ = ...` doesn't present any benefits).
I also added a little help message span.
changelog:[`let_underscore_untyped`]: Fix the help message confusion + add a help message span.
check for `..` pattern in `redundant_pattern_matching`
The `redundant_pattern_matching` lint currently checks for `if let Some(_) = ...`, but not for `if let Some(..) = ...`.
This PR makes sure to also check for the `..` pattern in tuple structs.
It also found one such instance in clippy itself so that shows it's worth checking for this pattern as well 😅
changelog: [`redundant_pattern_matching`]: check for `..` pattern in tuple structs
Fix false positive in `allow_attributes`
This would emit a warning if used in a proc-macro with the feature `lint_reasons` enabled. This is now fixed.
changelog: [`allow_attributes`]: Don't lint if in external macro
Ignore `shadow` warns in code from macro expansions
This PR fixes https://github.com/rust-lang/rust-clippy/issues/9757
I am in doubt if just looking for `pat.span.from_expansion()` would be sufficient instead of looking for both `pat.span.desugaring_kind().is_some()` or `pat.span.from_expansion()`. The tests (including the new one) passes if I leave the only `if pat.span.from_expansion()`. Any feedbacks?
Also, this is my first PR here, sorry for anything and thanks for the patience!
changelog: [`shadow_same`, `shadow_reuse`, `shadow_unrelated`]: avoiding warns in macro-generated code
New lint: detect `if` expressions with simple boolean assignments to the same target
Closes#10430
changelog: [`needless_bool_assign`] new lint to detect simple boolean assignment to the same target in `if` branches
Run various queries from other queries instead of explicitly in phases
These are just legacy leftovers from when rustc didn't have a query system. While there are more cleanups of this sort that can be done here, I want to land them in smaller steps.
This phased order of query invocations was already a lie, as any query that looks at types (e.g. the wf checks run before) can invoke e.g. const eval which invokes borrowck, which invokes typeck, ...
Don't suggest `suboptimal_flops` unavailable in nostd
Fixes#10634
changelog: Enhancement: [`suboptimal_flops`]: Do not suggest `{f32,f64}::abs()` or `{f32,f64}::mul_add()` in a `no_std`-environment.
Add `items_after_test_module` lint
Resolves task *3* of #10506, alongside *1* resolved at #10543 in an effort to help standarize a little bit more testing modules.
---
changelog:[`items_after_test_module`]: Added the lint.
make [`len_zero`] lint not spanning over parenthesis
sorry it should be a quick fix but I was caught up by other stuffs last couple weeks 🤦♂️
---
fixes: #10529
changelog: make [`len_zero`] lint not spanning over parenthesis
Add offset_of! macro (RFC 3308)
Implements https://github.com/rust-lang/rfcs/pull/3308 (tracking issue #106655) by adding the built in macro `core::mem::offset_of`. Two of the future possibilities are also implemented:
* Nested field accesses (without array indexing)
* DST support (for `Sized` fields)
I wrote this a few months ago, before the RFC merged. Now that it's merged, I decided to rebase and finish it.
cc `@thomcc` (RFC author)
Suppress the triggering of some lints in derived structures
Fixes#10185Fixes#10417
For `integer_arithmetic`, `arithmetic_side_effects` and `shadow_reuse`.
* ~~Not sure how to test these use-cases so feel free to point any method or any related PR.~~
---
changelog: FP: [`integer_arithmetic`], [`arithmetic_side_effects`]: No longer lint inside proc macros
[#10203](https://github.com/rust-lang/rust-clippy/pull/10203)
<!-- changelog_checked -->
Add size-parameter to unecessary_box_returns
Fixes#10641
This adds a configuration-knob to the `unecessary_box_returns`-lint which allows _not_ linting a `fn() -> Box<T>` if `T` is "large". The default byte size above which we no longer lint is 128 bytes (due to https://github.com/rust-lang/rust-clippy/issues/4652#issue-505670554, also used in #9373). The overall rational is given in #10641.
---
changelog: Enhancement: [`unnecessary_box_returns`]: Added new lint configuration `unnecessary-box-size` to set the maximum size of `T` in `Box<T>` to be linted
[#10651](https://github.com/rust-lang/rust-clippy/pull/10651)
<!-- changelog_checked -->
This allows allocating `Expr`s into a dropless arena, which is useful
for using length prefixed thing slices in HIR, since these can only be
allocated in the dropless arena and not in a typed arena. This is
something I'm working on.
Fix UB in `as_ptr_cast_mut` documentation
changelog: none
Fixes#10628
There's no `String::as_mut_ptr` surprisingly, so the example is actually calling `str::as_mut_ptr` on an empty `str`
Clear with drain
Fixes#10572: both the original intent of the issue (extending `clear_with_drain`) and the false negative for `collection_is_never_read` I found in the process are fixed by this PR.
changelog: [`clear_with_drain`]: extend to 5 other types of containers. [`collection_is_never_read`]: fix false negative for `String`s.
remove unusued `#![feature(drain_filter)]`
The unstable feature does not appear to be used and its presence blocks work in https://github.com/rust-lang/rust/pull/104455
changelog: none
fix `single_component_path_imports` FP on `self::<import>::..`
fixes#10549
I noticed that a couple functions in the file I was working on took `cx` as a parameter but didn't use them, so I removed that. Can revert if desired because it isn't related to my changes.
changelog: [`single_component_path_imports`] don't suggest removing import when it is used as `self::<import>::..`
fix [`mem_replace_option_with_none`] not considering field variables
fixes: #9824
---
changelog: fix [`mem_replace_option_with_none`] not considering field variables
Make redundant_async_block a more complete late pass
This lets us detect more complex situations: `async { x.await }` is simplified into `x` if:
- `x` is an expression without side-effect
- or `x` is an `async` block itself
In both cases, no part of the `async` expression can be part of a macro expansion.
Fixes#10509.
Fixes#10525.
changelog: [`redundant_async_block`] Do not lint expressions with side effects.
This lets us detect more complex situations: `async { x.await }` is
simplified into `x` if:
- `x` is an expression without side-effect
- or `x` is an async block itself
In both cases, no part of the `async` expression can be part of a macro
expansion.
Add `tests_outside_test_module` lint
Adds `tests_outside_test_module` from #10506. This PR **doesn't** close the issue, just resolves task 1.
changelog: [`tests_outside_test_module`]: The lint has been added
Fix bug with getting parent directories in `lookup_conf_file`
Currently `lookup_conf_file` doesn't canonicalize the configuration directory before using [`PathBuf::pop`](https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.pop) to get the parent directory. This isn't usually an issue when clippy is invoked via `cargo clippy` as `CARGO_MANIFEST_DIR` is already canonicalized. However, this currently causes `clippy-driver` to ignore any `clippy.toml` in any parent directories when `CARGO_MANIFEST_DIR` and `CLIPPY_CONF_DIR` are not set.
changelog: Fix a bug that would cause parent directories not to be searched for `clippy.toml` when using `clippy-driver` directly.
Mini-fix `double_must_use` for async functions
From Rust 1.67 onwards, the `#[must_use]` attribute also applies to the `Future::Output` (rust-lang/rust#100633). So the lint `double_must_use` was linting all async functions. This PR changes the `double_must_use` lint so it ignores `async` functions.
---
Closes#10486
changelog: [`double_must_use`]: Fix false positive in async function
Initial support for return type notation (RTN)
See: https://smallcultfollowing.com/babysteps/blog/2023/02/13/return-type-notation-send-bounds-part-2/
1. Only supports `T: Trait<method(): Send>` style bounds, not `<T as Trait>::method(): Send`. Checking validity and injecting an implicit binder for all of the late-bound method generics is harder to do for the latter.
* I'd add this in a follow-up.
3. ~Doesn't support RTN in general type position, i.e. no `let x: <T as Trait>::method() = ...`~
* I don't think we actually want this.
5. Doesn't add syntax for "eliding" the function args -- i.e. for now, we write `method(): Send` instead of `method(..): Send`.
* May be a hazard if we try to add it in the future. I'll probably add it in a follow-up later, with a structured suggestion to change `method()` to `method(..)` once we add it.
7. ~I'm not in love with the feature gate name 😺~
* I renamed it to `return_type_notation` ✔️
Follow-up PRs will probably add support for `where T::method(): Send` bounds. I'm not sure if we ever want to support return-type-notation in arbitrary type positions. I may also make the bounds require `..` in the args list later.
r? `@ghost`
Add suggestions to `extra_unused_type_parameters`
Change the `extra_unused_type_parameters` lint to provide machine applicable suggestions rather than just help messages. Exception to this are cases when any unused type parameters appear bounded in where clauses - for now I've deemed these cases unfixable and separated them out. Future work might be able to provide suggestions in these cases.
Also, added a test case for the `avoid_breaking_exported_api` config option.
r? `@flip1995`
changelog: [`extra_unused_type_parameters`]: Now provides fixable suggestions.
Added the `[unnecessary_box_returns]` lint
fixes#5
I'm not confident in the name of this lint. Let me know if you can think of something better
---
changelog: New lint: ``[`unnecessary_box_returns`]``
[#9102](https://github.com/rust-lang/rust-clippy/pull/9102)
<!-- changelog_checked -->
Fix allow attribute, items from macros in `items_after_statements`
Fixes#10540
changelog: [`items_after_statements`]: Fixes `#[allow(clippy::items_after_statements)]` when applied to an item, and ignores items after statements from different macro contexts
Remove the `NodeId` of `ast::ExprKind::Async`
This is a followup to https://github.com/rust-lang/rust/pull/104833#pullrequestreview-1314537416.
In my original attempt, I was using `LoweringContext::expr`, which was not correct as it creates a fresh `DefId`.
It now uses the correct `DefId` for the wrapping `Expr`, and also makes forwarding `#[track_caller]` attributes more explicit.
Make this function work with signed integer types by extracting the
underlying type and finding the min and max values.
Change the signature to make it more consistent:
- The range is now given as an `Expr` in order to extract the type
- The container's path is now passed, and only as an `Option` so that
the function can be called in the general case without a container
fix [`cast_possible_truncation`] offering wrong suggestion for casting float to integer
fixes: #10366
---
changelog: [`cast_possible_truncation`] Fix incorrect suggestions when casting from float types or to `_`
Wrap `transmutes_expressible_as_ptr_casts` suggestions in parentheses
changelog: [`transmutes_expressible_as_ptr_casts`]: Fix suggestion missing wrapping parentheses
Fixes#10449
r? `@Jarcho`
Is this the best way to go about this? `unused_parens` will catch the unnecessary ones but emitting them in the first place isn't ideal
suggest `try_into` when casting to wildcard type;
fix [`cast_possible_truncation`] suggesting useless parenthesis;
remove suggesting for float to float conversion in [`cast_possible_truncation`]
style nit
New lint: detect unnecessary struct building
Fixes#10476.
Running this lint on the top 500 crates produced one hit (in `rust-lang/rust-bindgen`) and [a PR has been submitted there](https://github.com/rust-lang/rust-bindgen/pull/2440).
changelog: [`unnecessary_struct_initialization`]: new lint
The lint is very slow as it doesn't cache the deeply nested check for
the attribute. If we cache it, we can reduce the time spent on checking
`rustc_borrowck` from 28s to 9s, which is a nice improvement. In the
profile, the time inside `has_sig_drop_attr` goes from 66% to 0.2%,
which is a lot more reasonable.
See the PR for nice graphs.
