`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
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...
uninhabited_reference: new lint
Close#11851
The lint is implemented on function parameters and return types, as this is the place where the risk of exchanging references to uninhabited types is the highest. Other constructs, such as in a local variable,
would require the use of `unsafe` and will clearly be done on purpose.
changelog: [`uninhabited_reference`]: new lint
Add a function to check whether binary oprands are nontrivial
fixes [#issue11885](https://github.com/rust-lang/rust-clippy/issues/11885)
It's hard to check whether operator is overrided through context of lint.
So, assume non-trivial structure like tuple, array or sturt, using a overrided binary operator in this lint, which might cause a side effict.
This is not detected before.
Althrough this might weaken the ability of this lint, it may more useful than before. Maybe this lint will cause an error, but now, it not. And assuming side effect of non-trivial structure with operator is not a bad thing, right?
changelog: Fix: [`no_effect`] check if binary operands are nontrivial
fix(ptr_as_ptr): handle `std::ptr::null{_mut}`
close rust-lang#11066
close rust-lang#11665
close rust-lang#11911
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`ptr_as_ptr`]: handle `std::ptr::null` and `std::ptr::null_mut`
needless_borrows_for_generic_args: Handle when field operand impl Drop
Before this fix, the lint had a false positive, namely when a reference was taken to a field when the field operand implements a custom Drop. The compiler will refuse to partially move a type that implements Drop, because that would put the type in a weird state.
## False Positive Example (Fixed)
```rs
struct CustomDrop(String);
impl Drop for CustomDrop {
fn drop(&mut self) {}
}
fn check_str<P: AsRef<str>>(_to: P) {}
fn test() {
let owner = CustomDrop(String::default());
check_str(&owner.0); // Don't lint. `owner` can't be partially moved because it impl Drop
}
```
changelog: [`needless_borrows_for_generic_args`]: Handle when field operand impl Drop
Update regex-syntax to support new word boundry assertions
From the regex v1.10.0 release notes [1]:
This is a new minor release of regex that adds support for start
and end word boundary assertions. [...]
The new word boundary assertions are:
• \< or \b{start}: a Unicode start-of-word boundary (\W|\A
on the left, \w on the right).
• \> or \b{end}: a Unicode end-of-word boundary (\w on the
left, \W|\z on the right)).
• \b{start-half}: half of a Unicode start-of-word boundary
(\W|\A on the left).
• \b{end-half}: half of a Unicode end-of-word boundary
(\W|\z on the right).
[1]: https://github.com/rust-lang/regex/blob/master/CHANGELOG.md#1100-2023-10-09
changelog: [`regex`]: add support for start and end word boundary assertions ("\<", "\b{start}", etc.) introduced in regex v0.10
Check whether operator is overrided with a `struct` operand.
The struct here refers to `struct`, `enum`, `union`.
Add and fix test for `no_effect` lint.
From the regex v1.10.0 release notes [1]:
This is a new minor release of regex that adds support for start
and end word boundary assertions. [...]
The new word boundary assertions are:
• \< or \b{start}: a Unicode start-of-word boundary (\W|\A
on the left, \w on the right).
• \> or \b{end}: a Unicode end-of-word boundary (\w on the
left, \W|\z on the right)).
• \b{start-half}: half of a Unicode start-of-word boundary
(\W|\A on the left).
• \b{end-half}: half of a Unicode end-of-word boundary
(\W|\z on the right).
[1]: https://github.com/rust-lang/regex/blob/master/CHANGELOG.md#1100-2023-10-09
expending lint [`blocks_in_if_conditions`] to check match expr as well
closes: #11814
changelog: rename lint `blocks_in_if_conditions` to [`blocks_in_conditions`] and expand it to check blocks in match scrutinees
[`missing_asserts_for_indexing`]: accept length equality checks
Fixes#11835
The lint now allows indexing with indices 0 and 1 when an `assert!(x.len() == 2);` is found.
(Also fixed a typo in the doc example)
changelog: [`missing_asserts_for_indexing`]: accept len equality checks as a valid assertion
Stabilize C string literals
RFC: https://rust-lang.github.io/rfcs/3348-c-str-literal.html
Tracking issue: https://github.com/rust-lang/rust/issues/105723
Documentation PR (reference manual): https://github.com/rust-lang/reference/pull/1423
# Stabilization report
Stabilizes C string and raw C string literals (`c"..."` and `cr#"..."#`), which are expressions of type [`&CStr`](https://doc.rust-lang.org/stable/core/ffi/struct.CStr.html). Both new literals require Rust edition 2021 or later.
```rust
const HELLO: &core::ffi::CStr = c"Hello, world!";
```
C strings may contain any byte other than `NUL` (`b'\x00'`), and their in-memory representation is guaranteed to end with `NUL`.
## Implementation
Originally implemented by PR https://github.com/rust-lang/rust/pull/108801, which was reverted due to unintentional changes to lexer behavior in Rust editions < 2021.
The current implementation landed in PR https://github.com/rust-lang/rust/pull/113476, which restricts C string literals to Rust edition >= 2021.
## Resolutions to open questions from the RFC
* Adding C character literals (`c'.'`) of type `c_char` is not part of this feature.
* Support for `c"..."` literals does not prevent `c'.'` literals from being added in the future.
* C string literals should not be blocked on making `&CStr` a thin pointer.
* It's possible to declare constant expressions of type `&'static CStr` in stable Rust (as of v1.59), so C string literals are not adding additional coupling on the internal representation of `CStr`.
* The unstable `concat_bytes!` macro should not accept `c"..."` literals.
* C strings have two equally valid `&[u8]` representations (with or without terminal `NUL`), so allowing them to be used in `concat_bytes!` would be ambiguous.
* Adding a type to represent C strings containing valid UTF-8 is not part of this feature.
* Support for a hypothetical `&Utf8CStr` may be explored in the future, should such a type be added to Rust.
Before this fix, the lint had a false positive, namely when a reference
was taken to a field when the field operand implements a custom Drop.
The compiler will refuse to partially move a type that implements Drop,
because that would put the operand in a weird state. See added
regression test.
`option_if_let_else`: do not trigger on expressions returning `()`
Fix#11893
Trigerring on expressions returning `()` uses the arguments of the `map_or_else()` rewrite only for their side effects. This does lead to code which is harder to read than the original.
changelog: [`option_if_let_else`]: do not trigger on unit expressions
add lint against unit tests in doctests
During RustLab, Alice Ryhl brought to my attention that the Andoid team stumbled over the fact that if one attempts to write a unit test within a doctest, it will be summarily ignored. So this lint should help people wondering why their tests won't run.
---
changelog: New lint: [`test_attr_in_doctest`]
[#11872](https://github.com/rust-lang/rust-clippy/pull/11872)
Fix#11893
Trigerring on expressions returning `()` uses the arguments of the
`map_or_else()` rewrite only for their side effects. This does lead
to code which is harder to read than the original.
[`redundant_guards`]: catch `is_empty`, `starts_with` and `ends_with` on slices and `str`s
Fixes#11807
Few things worth mentioning:
- Taking `snippet`s is now done at callsite, instead of passing a span and doing it in `emit_redundant_guards`. This is because we now need custom suggestion strings in certain places, like `""` for `str::is_empty`.
- This now uses `snippet` instead of `snippet_with_applicability`. I don't think this really makes any difference for `MaybeIncorrect`, though?
- This could also lint byte strings, as they're of type `&[u8; N]`, but that can be ugly so I decided to leave it out for now
changelog: [`redundant_guards`]: catch `str::is_empty`, `slice::is_empty`, `slice::starts_with` and `slice::ends_with`
[`redundant_closure_call`]: avoid duplicated `async` keyword when triggering on closure that returns `async` block
close#11357
----
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`redundant_closure_call`]: avoid duplicated `async` keyword when triggering on closure that returns `async` block
Don't suggest `a.mul_add(b, c)` if parameters are not float
clippy::suboptimal_flops used to not check if the second parameter to f32/f64.mul_add() was float. Since the method is only defined to take `Self` as parameters, the suggestion was wrong.
Fixes#11831
changelog: [`suboptimal_float`]: Don't suggest `a.mul_add(b, c)` if parameters are not f32/f64
[`ptr_arg`]: recognize methods that also exist on slices
Fixes#11816
Not a new lint, just a very small improvement to the existing `ptr_arg` lint which would have caught the linked issue.
The problem was that the lint checks if a `Vec`-specific method was called, that is, if the receiver is `Vec<_>`.
This is the case for `len` and `is_empty`, however these methods also exist on slices so we can still lint there.
This logic exists in a different lint, so we can just reuse that here.
Interestingly, there was even a comment up top that explained what it should have been doing, but the logic for it just wasn't there?
changelog: [`ptr_arg`]: recognize methods that also exist on slices
<sub>Also, this is my 100th PR to clippy 🎉 </sub>
`manual_try_fold`: check that `fold` is really `Iterator::fold`
Fix#11876
changelog: [`manual_try_fold`]: suggest using `try_fold` only for `Iterator::fold` uses
Create new lint `option_map_or_err_ok`
Fixes#10045.
For the following code:
```rust
let opt = Some(1);
opt.map_or(Err("error"), Ok);
```
It suggests to instead write:
```rust
let opt = Some(1);
opt.ok_or("error");
```
r? `@flip1995`
changelog: Create new lint `option_map_or_err_ok`
suggest alternatives to iterate an array of ranges
works towards #7125
changelog: [`single_element_loop`]: suggest better syntax when iterating over an array of a single range
`@thinkerdreamer` and myself worked on this issue during a workshop by `@llogiq` at the RustLab 2023 conference. It is our first contribution to clippy.
When iterating over an array of only one element, _which is a range_, our change suggests to replace the array with the contained range itself. Additionally, a hint is printed stating that the user probably intended to iterate over the range and not the array. If the single element in the array is not a range, the previous suggestion in the form of `let {pat_snip} = {prefix}{arg_snip};{block_str}`is used.
This change lints the array with the single range directly, so any prefixes or suffixes are covered as well.
[`deprecated_semver`]: Allow `#[deprecated(since = "TBD")]`
"TBD" is allowed by rustdoc, saying that it will be deprecated in a future version. rustc will also not actually warn on it.
I found this while checking the rust-lang/rust with clippy.
changelog: [`deprecated_semver`]: allow using `since = "TBD"`
[`missing_asserts_for_indexing`]: work with bodies instead of blocks separately
Fixes#11856
Before this change, this lint would check blocks independently of each other, which means that it misses `assert!()`s from parent blocks.
```rs
// check_block
assert!(x.len() > 1);
{
// check_block
// no assert here
let _ = x[0] + x[1];
}
```
This PR changes it to work with bodies rather than individual blocks. That means that a function will be checked in one go and we can remember if an `assert!` occurred anywhere.
Eventually it would be nice to have a more control flow-aware analysis, possibly by rewriting it as a MIR lint, but that's more complicated and I wanted this fixed first.
changelog: [`missing_asserts_for_indexing`]: accept `assert!`s from parent blocks
Fix iter_kv_map false positive into_keys and into_values suggestion
fixes: #11752
changelog: [`iter_kv_map`]: fix false positive: Don't suggest `into_keys()` and `into_values()` if the MSRV is to low
Add tests for issues #10285, #10286, #10289, #10287Fixes#10285.
Fixes#10286.
Fixes#10289.
Fixes#10287.
This PR simply adds tests for the listed issues as they're already implemented so we can close them.
r? `@blyxyas`
changelog:none
Split `doc.rs` up into a subdirectory
So, first, sorry for the bad diff. 😅
In #11798, `@flip1995` suggested splitting `doc.rs` up, much like how we have the `methods/`, `matches/`, `types/` subdirectories.
I agree with this, the file is getting bigger as we add more and more doc lints that it makes sense to do this refactoring.
This is purely an internal change that moves things around a bit.
(**EDIT:** depending on the outcome of https://github.com/rust-lang/rust-clippy/pull/11801#issuecomment-1816715615 , this may change the lint group name from `doc_markdoc` to `doc`).
I tried to not change any of the actual logic of the lints and as such some things weren't as easy to move to a separate file. So we still have some `span_lint*` calls in the `doc/mod.rs` file, which I think is fine. This is also the case in `methods/mod.rs`.
Also worth mentioning that the lints missing_errors_doc, missing_panics_doc, missing_safety_doc and unnecessary_safety_doc have a lot of the same logic so it didn't make much sense for each of these to be in their own file. Instead I just put them all in `missing_headers.rs`
I also added a bit of documentation to the involved `check_{attrs,doc}` methods.
changelog: none
Improve maybe misused cfg
Follow-up of the improvements that were suggested to me in https://github.com/rust-lang/rust-clippy/pull/11821:
* I unified the output to use the same terms.
* I updated the code to prevent creating a new symbol.
r? `@blyxyas`
changelog: [`maybe_misued_cfg`]: Output and code improvements
Verify Borrow<T> semantics for types that implement Hash, Borrow<str> and Borrow<[u8]>.
Fixes#11710
The essence of the issue is that types that implement Borrow<T> provide a facet or a representation of the underlying type. Under these semantics `hash(a) == hash(a.borrow())`.
This is a problem when a type implements `Borrow<str>`, `Borrow<[u8]>` and Hash, it is expected that the hash of all three types is identical. The problem is that the hash of [u8] is not the same as that of a String, even when the byte reference ([u8]) is derived from `.as_bytes()`
- [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`
---
- [x] Explanation of the issue in the code
- [x] Tests reproducing the issue
- [x] Lint rule and emission
---
changelog: New lint: [`impl_hash_borrow_with_str_and_bytes`]
[#11781](https://github.com/rust-lang/rust-clippy/pull/11781)
Implements a lint to prevent implementation of Hash, Borrow<str> and
Borrow<[u8]> as it breaks Borrow<T> "semantics". According to the book,
types that implement Borrow<A> and Borrow<B> must ensure equality of
borrow results under Eq,Ord and Hash.
> In particular Eq, Ord and Hash must be equivalent for borrowed and
owned values: x.borrow() == y.borrow() should give the same result as x == y.
In the same way, hash(x) == hash(x as Borrow<[u8]>) != hash(x as Borrow<str>).
changelog: newlint [`impl_hash_with_borrow_str_and_bytes`]
clippy::suboptimal_flops used to not check if the second parameter to f32/f64.mul_add() was float. Since the method is
only defined to take `Self` as paremters, the suggestion was wrong.
Fixes#11831
teach `eager_or_lazy` about panicky arithmetic operations
Fixes#9422Fixes#9814Fixes#11793
It's a bit sad that we have to do this because arithmetic operations seemed to me like the prime example where a closure would not be necessary, but this has "side effects" (changes behavior when going from lazy to eager) as some of these panic on overflow/underflow if compiled with `-Coverflow-checks` (which is the default in debug mode).
Given the number of backlinks in the mentioned issues, this seems to be a FP that is worth fixing, probably.
changelog: [`unnecessary_lazy_evaluations`]: don't lint if closure has panicky arithmetic operations
Extend `maybe_misused_cfg` lint over `cfg(test)`
Fixes#11240.
One thought I had is that we could use the levenshtein distance (of 1) to ensure this is indeed `test` that was targeted. But maybe it's overkill, not sure.
changelog: [`maybe_misused_cfg`]: Extend lint over `cfg(test)`
r? `@blyxyas`
This was made possible by the removal of plugin support, which
simplified lint store creation.
This simplifies the places in rustc and rustdoc that call
`describe_lints`, which are early on. The lint store is now built before
those places, so they don't have to create their own lint store for
temporary use, they can just use the main one.
Change `if_same_then_else` to be a `style` lint
CC #3770
From https://github.com/rust-lang/rust-clippy/issues/3770#issuecomment-687565594 (`@flip1995):`
> Oh I thought I replied to this: I definitely see now that having this
> as a correctness lint might be the wrong categorization. What we might
> want to do is to just allow this lint, if there are comments in the
> arm bodies. But a good first step would be to downgrade this lint to
> style or complexity. I would vote for style since merging two arms is
> not always less complex.
changelog: [`if_same_then_else`]: Change to be a `style` lint
[`impl_trait_in_params`]: avoid ICE when function with `impl Trait` type has no parameters
Fixes#11803
If I'm reading the old code correctly, it was taking the span of the first parameter (without checking that it exists, which caused the ICE) and uses that to figure out where the generic parameter to insert should go (cc `@blyxyas` you wrote the lint, is that correct?).
This seemed equivalent to just `generics.span`, which doesn't require calculating the spans like that and simplifies it a fair bit
changelog: don't ICE when function has no parameters but generics have an `impl Trait` type
CC #3770
From https://github.com/rust-lang/rust-clippy/issues/3770#issuecomment-687565594 (@flip1995):
> Oh I thought I replied to this: I definitely see now that having this
> as a correctness lint might be the wrong categorization. What we might
> want to do is to just allow this lint, if there are comments in the
> arm bodies. But a good first step would be to downgrade this lint to
> style or complexity. I would vote for style since merging two arms is
> not always less complex.
Implement new lint `iter_over_hash_type`
Implements and fixes https://github.com/rust-lang/rust-clippy/issues/11788
This PR adds a new *restriction* lint `iter_over_hash_type` which prevents `Hash`-types (that is, `HashSet` and `HashMap`) from being used as the iterator in `for` loops.
The justification for this is because in `Hash`-based types, the ordering of items is not guaranteed and may vary between executions of the same program on the same hardware. In addition, it reduces readability due to the unclear iteration order.
The implementation of this lint also ensures the following:
- Calls to `HashMap::keys`, `HashMap::values`, and `HashSet::iter` are also denied when used in `for` loops,
- When this expression is used in procedural macros, it is not linted/denied.
changelog: add new `iter_over_hash_type` lint to prevent unordered iterations through hashed data structures
Don't check for late-bound vars, check for escaping bound vars
Fixes an assertion that didn't make sense. Many valid and well-formed types *have* late-bound vars (e.g. `for<'a> fn(&'a ())`), they just must not have *escaping* late-bound vars in order to be normalized correctly.
Addresses rust-lang/rust-clippy#11230, cc `@jyn514` and `@matthiaskrgr`
changelog: don't check for late-bound vars, check for escaping bound vars. Addresses rust-lang/rust-clippy#11230
Fixes to `manual_let_else`'s divergence check
A few changes to the divergence check in `manual_let_else` and moves it the implementation to `clippy_utils` since it's generally useful:
* Handle internal `break` and `continue` expressions.
e.g. The first loop is divergent, but the second is not.
```rust
{
loop {
break 'outer;
};
}
{
loop {
break;
};
}
```
* Match rust's definition of divergence which is defined via the type system.
e.g. The following is not considered divergent by rustc as the inner block has a result type of `()`:
```rust
{
'a: {
panic!();
break 'a;
};
}
```
* Handle when adding a single semicolon would make the expression divergent.
e.g. The following would be a divergent if a semicolon were added after the `if` expression:
```rust
{ if panic!() { 0 } else { 1 } }
```
changelog: None
Lint `needless_borrow` and `explicit_auto_deref` on most union field accesses
Changes both lints to follow rustc's rules around auto-deref through `ManuallyDrop` union fields rather than just bailing on union fields.
changelog: [`needless_borrow`] & [`explicit_auto_deref`]: Lint on most union field accesses
[`map_identity`]: respect match ergonomics
Fixes#11764
Note: the original tests before this were slightly wrong themselves already and had to be changed. They were calling `map` on an iterator of `&(i32, i32)`s, so this PR would stop linting there, but they were meant to test something else unrelated to binding modes, so I just changed them to remove the references so that it iterates over owned values and they all bind by value. This way they continue to test what they checked for before: the identity function for tuple patterns.
changelog: [`map_identity`]: respect match ergonomics
Disable `vec_box` when using different allocators
Fixes#7114
This PR disables the `vec_box` lint when the `Box` and `Vec` use different allocators (but not when they use the same - custom - allocator).
For example - `Vec<Box<i32, DummyAllocator>>` will disable the lint, and `Vec<Box<i32, DummyAllocator>, DummyAllocator>` will not disable the lint.
In addition, the applicability of this lint has been changed to `Unspecified` due to the automatic fixes potentially breaking code such as the following:
```rs
fn foo() -> Vec<Box<i32>> { // -> Vec<i32>
vec![Box::new(1)]
}
```
It should be noted that the `if_chain->let-chains` fix has also been applied to this lint, so the diff does contain many changes.
changelog: disable `vec_box` lint when using nonstandard allocators
Fix `dbg_macro` semi span calculation
`span_including_semi` was using a `BytePos` to index into a file's source which happened to work because the root file of the test started at `BytePos` 0, it didn't work for other files
changelog: none
new lint: `unnecessary_fallible_conversions`
Closes#11577
A new lint that looks for calls such as `i64::try_from(1i32)` and suggests `i64::from(1i32)`. See lint description (and linked issue) for more details for why.
There's a tiny bit of overlap with the `useless_conversion` lint, in that the other one warns `T::try_from(T)` (i.e., fallibly converting to the same type), so this lint ignores cases like `i32::try_from(1i32)` to avoid emitting two warnings for the same expression.
Also, funnily enough, with this one exception, this lint would warn on exactly every case in the `useless_conversion_try` ui test that `useless_conversion` didn't cover (but never two warnings at the same time), which is neat. I did add an `#![allow]` though since we don't want interleaved warnings from multiple lints in the same uitest.
changelog: new lint: `unnecessary_fallible_conversions`
fix enum_variant_names depending lint depending on order
changelog: [`enum_variant_names`]: fix single word variants preventing lint of later variant pre/postfixed with the enum name
fixes#11494
Single word variants prevented checking the `check_enum_start` and `check_enum_end` for being run on later variants
Fix missing parenthesis in suboptimal floating point help
This fixes#11559 by adding a branch in the `Neg` implementation for `Sugg` that adds parentheses to keep precedence in order, then using that in the suggestion. I also removed some needless `.to_string()`s while I was at it.
---
changelog: none
[`iter_without_into_iter`]: fix papercuts in suggestion and restrict linting to exported types
See #11692 for more context.
tldr: the lint `iter_without_into_iter` has suggestions that don't compile, which imo isn't that problematic because it does have the appropriate `Applicability` that tells external tools that it shouldn't be auto-applied.
However there were some obvious "errors" in the suggestion that really should've been included in my initial PR adding the lint, which is fixed by this PR:
- `IntoIterator::into_iter` needs a `self` argument.
- `IntoIterator::Iter` associated type doesn't exist. This should've just been `Item`.
This still doesn't make it machine applicable, and the remaining things are imho quite non-trivial to implement, as I've explained in https://github.com/rust-lang/rust-clippy/issues/11692#issuecomment-1773886111.
I personally think it's fine to leave it there and let the user change the remaining errors when copy-pasting the suggestion (e.g. errors caused by lifetimes that were permitted in fn return-position but are not in associated types).
This is how many of our other lint suggestions already work.
Also, we now restrict linting to only exported types. This required moving basically all of the tests around since they were previously in the `main` function. Same for `into_iter_without_iter`. The git diff is a bit useless here...
changelog: [`iter_without_into_iter`]: fix papercuts in suggestion and restrict linting to exported types
(cc `@lopopolo,` figured I should mention you since you created the issue)
Add `waker_clone_and_wake` lint to check needless `Waker` clones
Check for patterns of `waker.clone().wake()` and replace them with `waker.wake_by_ref()`.
An alternative name could be `waker_clone_then_wake`
changelog: [ `waker_clone_wake`]: new lint
Validate `feature` and `since` values inside `#[stable(…)]`
Previously the string passed to `#[unstable(feature = "...")]` would be validated as an identifier, but not `#[stable(feature = "...")]`. In the standard library there were `stable` attributes containing the empty string, and kebab-case string, neither of which should be allowed.
Pre-existing validation of `unstable`:
```rust
// src/lib.rs
#![allow(internal_features)]
#![feature(staged_api)]
#![unstable(feature = "kebab-case", issue = "none")]
#[unstable(feature = "kebab-case", issue = "none")]
pub struct Struct;
```
```console
error[E0546]: 'feature' is not an identifier
--> src/lib.rs:5:1
|
5 | #![unstable(feature = "kebab-case", issue = "none")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
For an `unstable` attribute, the need for an identifier is obvious because the downstream code needs to write a `#![feature(...)]` attribute containing that identifier. `#![feature(kebab-case)]` is not valid syntax and `#![feature(kebab_case)]` would not work if that is not the name of the feature.
Having a valid identifier even in `stable` is less essential but still useful because it allows for informative diagnostic about the stabilization of a feature. Compare:
```rust
// src/lib.rs
#![allow(internal_features)]
#![feature(staged_api)]
#![stable(feature = "kebab-case", since = "1.0.0")]
#[stable(feature = "kebab-case", since = "1.0.0")]
pub struct Struct;
```
```rust
// src/main.rs
#![feature(kebab_case)]
use repro::Struct;
fn main() {}
```
```console
error[E0635]: unknown feature `kebab_case`
--> src/main.rs:3:12
|
3 | #![feature(kebab_case)]
| ^^^^^^^^^^
```
vs the situation if we correctly use `feature = "snake_case"` and `#![feature(snake_case)]`, as enforced by this PR:
```console
warning: the feature `snake_case` has been stable since 1.0.0 and no longer requires an attribute to enable
--> src/main.rs:3:12
|
3 | #![feature(snake_case)]
| ^^^^^^^^^^
|
= note: `#[warn(stable_features)]` on by default
```
report `unused_import` for empty reexports even it is pub
Fixes#116032
An easy fix. r? `@petrochenkov`
(Discovered this issue while reviewing #115993.)
suggest passing function instead of calling it in closure for [`option_if_let_else`]
fixes: #11429
changelog: suggest passing function instead of calling it in closure for [`option_if_let_else`]
Avoid a `track_errors` by bubbling up most errors from `check_well_formed`
I believe `track_errors` is mostly papering over issues that a sufficiently convoluted query graph can hit. I made this change, while the actual change I want to do is to stop bailing out early on errors, and instead use this new `ErrorGuaranteed` to invoke `check_well_formed` for individual items before doing all the `typeck` logic on them.
This works towards resolving https://github.com/rust-lang/rust/issues/97477 and various other ICEs, as well as allowing us to use parallel rustc more (which is currently rather limited/bottlenecked due to the very sequential nature in which we do `rustc_hir_analysis::check_crate`)
cc `@SparrowLii` `@Zoxc` for the new `try_par_for_each_in` function
Skip if_not_else lint for '!= 0'-style checks
Currently, clippy makes unhelpful suggestions such as this:
```
warning: unnecessary `!=` operation
--> src/vm.rs:598:36
|
598 | *destination = if source & 0x8000 != 0 { 0xFFFF } else { 0 };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: change to `==` and swap the blocks of the `if`/`else`
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#if_not_else
= note: `-W clippy::if-not-else` implied by `-W clippy::pedantic`
```
Bit tests often take on the form `if foo & 0x1234 != 0 { … } else { … }`, and the `!= 0` part reads as "has any bits set". Therefore, this code already has the "correct" order, and shouldn't be changed.
This PR disables the lint for these cases, and in fact all cases where the condition is "foo is non-zero".
I did my homework:
- \[X] Followed [lint naming conventions][lint_naming] → Not applicable, this PR fixes an existing lint
- \[X] Added passing UI tests (including committed `.stderr` file) → Yes, `tests/ui/if_not_else_bittest.rs`
- \[X] `cargo test` passes locally
- \[X] Executed `cargo dev update_lints`
- \[X] Added lint documentation → Not applicable, this PR fixes an existing lint
- \[X] Run `cargo dev fmt`
changelog: Fix [`if_not_else`] false positive when something like `bitflags != 0` is used
[`map_identity`]: allow closure with type annotations
Fixes#9122
`.map(|a: u32| a)` can help type inference, so we should probably allow this and not warn about "unnecessary map of the identity function"
changelog: [`map_identity`]: allow closure with type annotations
add lint for struct field names
changelog: [`struct_field_names`]: lint structs with the same pre/postfix in all fields or with fields that are pre/postfixed with the name of the struct.
fixes#2555
I've followed general structure and naming from the code in [enum_variants](b788addfcc/clippy_lints/src/enum_variants.rs) lint, which implements the same logic for enum variants.
side effect for `enum_variants`:
use .first() instead of .get(0) in enum_variants lint
move to_camel_case to str_util module
move module, enum and struct name repetitions check to a single file `item_name_repetitions`
rename enum_variants threshold config option
Add regression test for #11610 about mutable usage of argument in async function for the `needless_pass_by_ref_mut` lint
Fixes https://github.com/rust-lang/rust-clippy/issues/11610.
This was already fixed. I simply added a regression test.
changelog: Add regression test for #11610 about mutable usage of argument in async function for the `needless_pass_by_ref_mut` lint
Make `multiple_unsafe_ops_per_block` ignore await desugaring
The await desugaring contains two calls (`Poll::new_unchecked` and `get_context`) inside a single unsafe block. That violates the lint.
fixes#11312
changelog: [`multiple_unsafe_ops_per_block`]: fix false positives in `.await`
[`unnecessary_lazy_eval`]: reduce applicability if closure has return type annotation
Fixes#11672
We already check if closure parameters don't have type annotations and reduce the applicability to `MaybeIncorrect` if they do, since those help type inference and removing them breaks code. We didn't do this for return type annotations however. This PR adds it. This doesn't change it to produce a fix that will compile, but it will prevent rustfix from auto-applying it.
(In general I'm not sure if we can suggest a fix that will compile. In this specific example, it might be possible to suggest `&[] as &[u8]`, but as-casts won't always work, e.g. `Default::default() as &[u8]` is a compile error, so just reducing applicability should be a safe fix in any case for now)
changelog: [`unnecessary_lazy_eval`]: reduce applicability to `MaybeIncorrect` if closure has return type annotation
[`get_first`]: lint on non-primitive slices
Fixes#11594
I left the issue open for a couple days before making the PR to see if anyone has something to say, but it looks like there aren't any objections to removing this check that prevented linting on non-primitive slices, so here's the PR now.
There's a couple of instances in clippy itself where we now emit the lint. The actual relevant change is in the first commit and fixing the `.get(0)` instances in clippy itself is in the 2nd commit.
changelog: [`get_first`]: lint on non-primitive slices
Fix/11134
Fix#11134
Hir of `qpath` will be `TypeRelative(Ty { kind: Path(LangItem...` when a closure contains macro (e.g. https://github.com/rust-lang/rust-clippy/issues/11651) and #11134, it causes panic.
This PR avoids panicking and emitting incomplete path string when `qpath` contains `LangItem`.
changelog: none
`impl_trait_in_params` now supports impls and traits
Before this PR, the lint `impl_trait_in_params`. This PR gives the lint support for functions in impls and traits. (Also, some pretty heavy refactor)
fixes#11548
changelog:[`impl_trait_in_params`] now supports `impl` blocks and functions in traits
Improve `redundant_locals` help message
Fixes#11625
AFAIK, `span_lint_and_help` points the beginning of spans when we pass multiple spans to the second argument, so This PR I also modified its help span and its message.
lint result of the given example in the issue will be:
```console
error: redundant redefinition of a binding `apple`
--> src/main.rs:5:5
|
5 | let apple = apple;
| ^^^^^^^^^^^^^^^^^^
|
help: `apple` is initially defined here
--> src/main.rs:4:9
|
4 | let apple = 42;
| ^^^^^
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_locals
```
I hope that this change might help reduce user confusion, but I'd appreciate alternative suggestions:)
changelog: [`redundant_locals`]: Now points at the rebinding of the variable
Fix `items_after_test_module` for non root modules, add applicable suggestion
Fixes#11050Fixes#11153
changelog: [`items_after_test_module`]: Now suggests a machine-applicable suggestion.
changelog: [`items:after_test_module`]: Also lints for non root modules
std_instead_of_core: avoid lint inside of proc-macro
- fixes https://github.com/rust-lang/rust-clippy/issues/10198
note: The lint for the reported `thiserror::Error` has been suppressed by [Don't lint unstable moves in std_instead_of_core](https://github.com/rust-lang/rust-clippy/pull/9545/files#diff-2cb8a24429cf9d9898de901450d640115503a10454d692dddc6a073a299fbb7eR29) because `thiserror::Error` internally implements `std::error::Error for (derived struct)`.
changelog: [`std_intead_of_core`]: avoid linting inside proc-macro
I confirmed this change fixes the problem:
<details>
<summary>test result without the change</summary>
```console
error: used import from `std` instead of `core`
--> tests/ui/std_instead_of_core.rs:65:14
|
LL | #[derive(ImplStructWithStdDisplay)]
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: this error originates in the derive macro `ImplStructWithStdDisplay` (in Nightly builds, run with -Z macro-backtrace for more info)
```
</details>
Move `needless_pass_by_ref_mut`: `suspicious` -> `nursery`
[Related to [this Zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/needless_pass_by_ref_mut.20isn't.20ready.20for.20stable)]
`needless_pass_by_ref_mut` has been released with some important bugs (notably having a lot of reported false positives and an ICE). So it may not be really ready for being in stable until these problems are solved. This PR changes the lint's category from `suspicious` to `nursery`, just that.
changelog: none
Partially outline code inside the panic! macro
This outlines code inside the panic! macro in some cases. This is split out from https://github.com/rust-lang/rust/pull/115562 to exclude changes to rustc.
There are cases where users create a unit variant for the purposes
of tracking the number of variants for an nonexhaustive enum.
We should check if an enum is explicitly marked as nonexhaustive
before reporting `manual_non_exhaustive` in these cases. Fixes#11583
new lint: `into_iter_without_iter`
Closes#9736 (part 2)
This implements the other lint that my earlier PR missed: given an `IntoIterator for &Type` impl, check that there exists an inherent `fn iter(&self)` method.
changelog: new lint: `into_iter_without_iter`
r? `@Jarcho` since you reviewed #11527 I figured it makes sense for you to review this as well?
[`manual_let_else`]: only omit block if span is from same ctxt
Fixes#11579.
The lint already had logic for omitting a block in `else` if a block is already present, however this didn't handle the case where the block is from a different expansion/syntax context. E.g.
```rs
macro_rules! panic_in_block {
() => { { panic!() } }
}
let _ = match Some(1) {
Some(v) => v,
_ => panic_in_block!()
};
```
It would see this in its expanded form as `_ => { panic!() }` and think it doesn't have to include a block in its suggestion because it is already there, however that's not true if it's from a different expansion like in this case.
changelog: [`manual_let_else`]: only omit block in suggestion if the block is from the same expansion
fixed fp caused by moving &mut reference inside of a closure
changelog: [`needless_pass_by_ref mut`]: fixes false positive caused by not covering mutable references passed to a closure inside of a fuction
fixes#11545
Remove most usage of `hir_ty_to_ty`
Removes the usages where there's a suitable query or the type was already available elsewhere. The remaining cases would all require more involved changes
changelog: none
r? `@Jarcho`
fix FP with needless_raw_string_hashes
changelog: Fix [`needless_raw_string_hashes`]: Continue the lint checking of raw string when `needless_raw_strings` is allowed.
fix#11420
[`redundant_guards`]: lint if the pattern is on the left side
A tiny improvement to the `redundant_guards` lint. There's no associated issue for this, just noticed it while going through the code.
Right now it warns on `Some(x) if x == 2` and suggests `Some(2)`, but it didn't do that for `Some(x) if 2 == x` (i.e. when the local is on the right side and the pattern on the left side).
changelog: [`redundant_guards`]: also lint if the pattern is on the left side
Change defaults of `accept-comment-above-statement` and `accept-comment-above-attributes`
This patch sets the two configuration options for `undocumented_unsafe_blocks` to `true` by default: these are `accept-comment-above-statement` and `accept-comment-above-attributes`. Having these values `false` by default prevents what many users would consider clean code, e.g. placing the `// SAFETY:` comment above a single-line functino call, rather than directly next to the argument.
This was originally discussed in https://github.com/rust-lang/rust-clippy/issues/11162
changelog: [`undocumented_unsafe_blocks`]: set
`accept-comment-above-statement` and `accept-comment-above-attributes` to `true` by default.
Fix mutaby used async function argument in closure for `needless_pass_by_ref_mut`
Fixes https://github.com/rust-lang/rust-clippy/issues/11380.
The problem was that it needed to go through closures as well in async functions to correctly find the mutable usage of async function arguments.
changelog: Correctly handle mutable usage of async function arguments in closures.
r? `@Centri3`
This patch sets the two configuration options for
`undocumented_unsafe_blocks` to `true` by default: these are
`accept-comment-above-statement` and `accept-comment-above-attributes`.
Having these values `false` by default prevents what many users would
consider clean code, e.g. placing the `// SAFETY:` comment above a
single-line functino call, rather than directly next to the argument.
changelog: [`undocumented_unsafe_blocks`]: set
`accept-comment-above-statement` and `accept-comment-above-attributes`
to `true` by default.
Add redundant_as_str lint
This lint checks for `as_str` on a `String` immediately followed by `as_bytes` or `is_empty` as those methods are available on `String` too. This could possibly also be extended to `&[u8]` in the future.
changelog: New lint [`redundant_as_str`] #11526
move required_consts check to general post-mono-check function
This factors some code that is common between the interpreter and the codegen backends into shared helper functions. Also as a side-effect the interpreter now uses the same `eval` functions as everyone else to get the evaluated MIR constants.
Also this is in preparation for another post-mono check that will be needed for (the current hackfix for) https://github.com/rust-lang/rust/issues/115709: ensuring that all locals are dynamically sized.
I didn't expect this to change diagnostics, but it's just cycle errors that change.
r? `@oli-obk`
This lint checks for `as_str` on a `String` immediately followed by `as_bytes` or `is_empty` as those methods are available on `String` too. This could possibly also be extended to `&[u8]` in the future.
Split `needless_borrow` into two lints
Splits off the case where the borrow is used as a generic argument to a function. I think the two cases are different enough to warrant a separate lint.
The tests for the new lint have been reordered to group related parts together. Two warning have been dropped, one looked like it was testing the generic argument form, but it ends up triggering the auto-deref variant. The second was just a redundant test that didn't do anything interesting.
An issue with cycle detection is also included. The old version was checking if a cycle was reachable from a block when it should have been checking if the block is part or a cycle.
As a side note, I'm liking the style of just jamming all the tests into separate scopes in main.
changelog: Split off `needless_borrows_for_generic_args` from `needless_borrow`
[`filter_map_bool_then`]: include multiple derefs from adjustments
In #11506 this lint was improved to suggest one deref if the bool is behind references (fixed the FP #11503), however it might need multiple dereferences if the bool is behind multiple layers of references or custom derefs. E.g. `&&&bool` needs `***b`.
changelog: [`filter_map_bool_then`]: suggest as many dereferences as there are needed to get to the bool
add extra `byref` checking for the guard's local
changelog: [`redundant_guards`]: Now checks if the variable is bound using `ref` before linting.
The lint should not be emitted, when the local variable is bind by-ref in the pattern.
fixes#11465
[`useless_conversion`]: don't lint if type parameter has unsatisfiable bounds for `.into_iter()` receiver
Fixes#11300.
Before this PR, clippy assumed that if it sees a `f(x.into_iter())` call and the type at that argument position is generic over any `IntoIterator`, then the `.into_iter()` call must be useless because `x` already implements `IntoIterator`, *however* this assumption is not right if the generic parameter has more than just the `IntoIterator` bound (because other traits can be implemented for the IntoIterator target type but not the IntoIterator implementor, as can be seen in the linked issue: `<[i32; 3] as IntoIterator>::IntoIter` satisfies `ExactSizeIterator`, but `[i32; 3]` does not).
So, this PR makes it check that the type parameter only has a single `IntoIterator` bound. It *might* be possible to check if the type of `x` in `f(x.into_iter())` satisfies all the bounds on the generic type parameter as defined on the function (which would allow removing the `.into_iter()` call even with multiple bounds), however I'm not sure how to do that, and the current fix should always work.
**Edit:** This PR has been changed to check if any of the bounds don't hold for the type of the `.into_iter()` receiver, so we can still lint in some cases.
changelog: [`useless_conversion`]: don't lint `.into_iter()` if type parameter has multiple bounds
fix filter_map_bool_then with a bool reference
changelog: [`filter_map_bool_then`]: Fix the incorrect autofix when the `bool` in question is a reference.
fix#11503
[`extra_unused_type_parameters`]: Fix edge case FP for parameters in where bounds
Generic parameters can end up being used on the left side of where-bounds if they are not directly bound but instead appear nested in some concrete generic type. Therefore, we should walk the left side of where bounds, but only if the bounded type is *not* a generic param, in which case we still need to ignore the bound.
Fixes#11302
changelog: [`extra_unused_type_parameters`]: Fix edge case false positive for parameters in where bounds
[`len_without_is_empty`]: follow type alias to find inherent `is_empty` method
Fixes#11165
When we see an `impl B` and `B` is a type alias to some type `A`, then we need to follow the type alias to look for an `is_empty` method on the aliased type `A`. Before this PR, it'd get the inherent impls of `B`, which there aren't any and so it would warn that there isn't an `is_empty` method even if there was one.
Passing the type alias `DefId` to `TyCtxt::type_of` gives us the aliased `DefId` (or simply return the type itself if it wasn't a type alias) so we can just use that
changelog: [`len_without_is_empty`]: follow type alias to find inherent `is_empty` method
[`implied_bounds_in_impls`]: include (previously omitted) associated types in suggestion
Fixes#11435
It now includes associated types from the implied bound that were omitted in the second bound. Example:
```rs
fn f() -> impl Iterator<Item = u8> + ExactSizeIterator> {..}
```
Suggestion before this change:
```diff
- pub fn my_iter() -> impl Iterator<Item = u32> + ExactSizeIterator {
+ pub fn my_iter() -> impl ExactSizeIterator {
```
It didn't include `<Item = u32>` on `ExactSizeIterator`. Now, with this change, it does.
```diff
- pub fn my_iter() -> impl Iterator<Item = u32> + ExactSizeIterator {
+ pub fn my_iter() -> impl ExactSizeIterator<Item = u32> {
```
We also now extend the span to include not just possible `+` ahead of it, but also behind it (an example for this is in the linked issue as well).
**Note:** The overall diff is a bit noisy, because building up the suggestion involves quite a bit more logic now and I decided to extract that into its own function. For that reason, I split this PR up into two commits. The first commit contains the actual "logic" changes. Second commit just moves code around.
changelog: [`implied_bounds_in_impls`]: include (previously omitted) associated types in suggestion
changelog: [`implied_bounds_in_impls`]: include the `+` behind bound if it's the last bound
Rename incorrect_impls to non_canonical_impls, move them to warn by default
The wording/category of these feel too strong to me, I would expect most of the time it's linting the implementations aren't going to be *incorrect*, just unnecessary
changelog: rename `incorrect_clone_impl_on_copy_type` to [`non_canonical_clone_impl`]
changelog: rename `incorrect_partial_ord_impl_on_ord_type` to [`non_canonical_partial_ord_impl`]
changelog: Move [`non_canonical_clone_impl`], [`non_canonical_partial_ord_impl`] to suspicious
Preserve literals and range kinds in `manual_range_patterns`
Fixes#11461
Also enables linting when there are 3 or fewer alternatives if one of them is already a range pattern
changelog: none
[`slow_vector_initialization`]: use the source span of vec![] macro and fix another FP
Fixes#11408
<details>
<summary>Also fixes a FP when the vec initializer comes from a macro other than `vec![]`</summary>
```rs
macro_rules! x {
() => { vec![] }
}
fn f() {
let mut v = x!();
v.resize(10, 0);
}
```
This shouldn't warn. The `x!` macro might be doing other things, so just replacing `x!()` with `vec![0; 10]` is not always an option.
</details>
I added some test cases for macro expansions, however I don't think there's a way to write a test for that specific warning that appeared in the linked issue. As far as I understand, that happens when the rust-src rustup component isn't installed (so the stdlib source is unavailable) and the span points to the `vec![]` *expansion*, instead of the `vec![]` that the user wrote.
changelog: [`slow_vector_initialization`]: use the source span of `vec![]` macro
changelog: [`slow_vector_initialization`]: only warn on `vec![]` expansions and allow other macros
skip `todo!()` in `never_loop`
As promised in #11450, here is an implementation which skips occurrences of the `todo!()` macro.
changelog: [`never_loop`]: skip loops containing `todo!()`
Don't pass extra generic arguments in `needless_borrow`
fixes#10253
Also switches to using `implements_trait` which does ICE when clippy's debug assertions are enabled.
changelog: None
[`implied_bounds_in_impls`]: don't ICE on default generic parameter and move to nursery
Fixes#11422
This fixes two ICEs ([1](https://github.com/rust-lang/rust-clippy/issues/11422#issue-1872351763), [2](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=2901e6febb479d3bd2a74f8a5b8a9305)), and moves it to nursery for now, because this lint needs some improvements in its suggestion (see #11435, for one such example).
changelog: Moved [`implied_bounds_in_impls`] to nursery (Now allow-by-default)
[#11437](https://github.com/rust-lang/rust-clippy/pull/11437)
changelog: [`implied_bounds_in_impls`]: don't ICE on default generic parameter in supertrait clause
r? `@xFrednet` (since you reviewed my PR that added this lint, I figured it might make sense to have you review this as well since you have seen this code before. If you don't want to review this, sorry! Feel free to reroll then)
--------
As for the ICE, it's pretty complicated and very confusing imo, so I'm going to try to explain the idea here (partly for myself, too, because I've confused myself several times writing- and fixing this):
<details>
<summary>Expand</summary>
The general idea behind the lint is that, if we have this function:
```rs
fn f() -> impl PartialEq<i32> + PartialOrd<i32> { 0 }
```
We want to lint the `PartialEq` bound because it's unnecessary. That exact bound is already specified in `PartialOrd<i32>`'s supertrait clause:
```rs
trait PartialOrd<Rhs>: PartialEq<Rhs> {}
// PartialOrd<i32>: PartialEq<i32>
```
The way it does this is in two steps:
- Go through all of the bounds in the `impl Trait` return type and collect each of the trait's supertrait bounds into a vec. We also store the generic arguments for later.
- `PartialEq` has no supertraits, nothing to add.
- `PartialOrd` is defined as `trait PartialOrd: PartialEq`, so add `PartialEq` to the list, as well as the generic argument(s) `<i32>`
Once we are done, we have these entries in the vec: `[(PartialEq, [i32])]`
- Go through all the bounds again, and looking for those bounds that have their trait `DefId` in the implied bounds vec.
- `PartialEq` is in that vec. However, that is not enough, because the trait is generic. If the user wrote `impl PartialEq<String> + PartialOrd<i32>`, then `PartialOrd` clearly doesn't imply `PartialEq`. Which means, we also need to check that the generic parameters match. This is why we also collected the generic arguments in `PartialOrd<i32>`. This process of checking generic arguments is pretty complicated and is also where the two ICEs happened.
The way it checks that the generic arguments match is by comparing the generic parameters in the super trait clause:
```rs
trait PartialOrd<Rhs>: PartialEq<Rhs> {}
// ^^^^^^^^^^^^^^
```
...this needs to match...
```rs
fn f() -> impl PartialEq<i32> + ...
// ^^^^^^^^^^^^^^
```
In the compiler, the `Rhs` generic parameter is its own type and we cannot just compare it to `i32`. We need to "substitute" it.
Internally, `Rhs` is represented as `Rhs#1` (the number next to # represents the type parameter index. They start at 0, but 0 is "reserved" for the implicit `Self` generic parameter).
How do we go from `Rhs#1` to `i32`? Well, we know that all the generic parameters had to be substituted in the `impl ... + PartialOrd<i32>` type. So we subtract 1 from the type parameter index, giving us 0 (`Self` is not specified in that list of arguments). We use that as the index into the generic argument list `<i32>`. That's `i32`. Now we know that the supertrait clause looks like `: PartialEq<i32>`.
Then, we can compare that to what the user actually wrote on the bound that we think is being implied: `impl PartialEq<i32> + ...`.
Now to the actual bug: this whole logic doesn't take into account *default* generic parameters. Actually, `PartialOrd` is defined like this:
```rs
trait PartialOrd<Rhs = Self>: PartialEq<Rhs> {}
```
If we now have a function like this:
```rs
fn f() -> impl PartialOrd + PartialEq {}
```
that logic breaks apart... We look at the supertrait predicate `: PartialEq<Rhs>` (`Rhs` is `Rhs#1`), then take the first argument in the generic argument list `PartialEq<..>` to resolve the `Rhs`, but at this point we crash because there *is no* generic argument.
The index 0 is out of bounds. If this happens (and we even get to linting here, which could only happen if it passes typeck), it must mean that that generic parameter has a default type that is not required to be specified.
This PR changes the logic such that if we have a type parameter index that is out of bounds, it looks at the definition of the trait and check that there exists a default type that we can use instead.
So, we see `<Rhs = Self>`, and use `Self` for substitution, and end up with this predicate: `: PartialEq<Self>`. No crash this time.
</details>
Also stabilizes saturating_int_assign_impl, gh-92354.
And also make pub fns const where the underlying saturating_*
fns became const in the meantime since the Saturating type was
created.
Fix span when linting `explicit_auto_deref` immediately after `needless_borrow`
fixes#11366
changelog: `explicit_auto_deref`: Fix span when linting immediately after `needless_borrow`
Add config flag for reborrows in explicit_iter_loop
This PR adds a config flag for enforcing explicit into iter lint for reborrowed values. The config flag, `enforce_iter_loop_reborrow`, can be added to clippy.toml files to enable the linting behaviour. By default the reborrow lint is disabled.
fixes: #11074
changelog: [`explicit_iter_loop`]: add config flag `enforce_iter_loop_reborrow` to disable reborrow linting by default
new lint: `iter_out_of_bounds`
Closes#11345
The original idea in the linked issue seemed to be just about arrays afaict, but I extended this to catch some other iterator sources such as `iter::once` or `iter::empty`.
I'm not entirely sure if this name makes a lot of sense now that it's not just about arrays anymore (specifically, not sure if you can call `.take(1)` on an `iter::Empty` to be "out of bounds"?).
changelog: [`iter_out_of_bounds`]: new lint
[`unnecessary_unwrap`]: lint on `.as_ref().unwrap()`
Closes#11371
This turned out to be a little more code than I originally thought, because the lint also makes sure to not lint if the user tries to mutate the option:
```rs
if option.is_some() {
option = None;
option.unwrap(); // don't lint here
}
```
... which means that even if we taught this lint to recognize `.as_mut()`, it would *still* not lint because that would count as a mutation. So we need to allow `.as_mut()` calls but reject other kinds of mutations.
Unfortunately it doesn't look like this is possible with `is_potentially_mutated` (seeing what kind of mutation happened).
This replaces it with a custom little visitor that does basically what it did before, but also allows `.as_mut()`.
changelog: [`unnecessary_unwrap`]: lint on `.as_ref().unwrap()`
skip float_cmp check if lhs is a custom type
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`float_cmp`]: allow float eq comparison when lhs is a custom type that implements PartialEq<f32/f64>
If the lhs of a comparison is not float, it means there is a user implemented PartialEq, and the caller is invoking that custom version of `==`, instead of the default floating point equal comparison.
People may wrap f32 with a struct (say `MyF32`) and implement its PartialEq that will do the `is_close()` check, so that `MyF32` can be compared with either f32 or `MyF32`.
[`if_then_some_else_none`]: look into local initializers for early returns
Fixes#11394
As the PR title says, problem was that it only looked for early returns in semi statements. Local variables don't count as such, so it didn't count `let _v = x?;` (or even just `let _ = return;`) as a possible early return and didn't realize that it can't lint then.
Imo the `stmts_contains_early_return` function that was used before is redundant. `contains_return` could already do that if we just made the parameter a bit more generic, just like `for_each_expr`, which can already accept `&[Stmt]`
changelog: [`if_then_some_else_none`]: look into local initializers for early returns
This commit adds a config flag for enforcing explicit into iter lint
for reborrowed values. The config flag, enforce_iter_loop_reborrow, can be
added to clippy.toml files to enable the linting behaviour. By default
the lint is not enabled.
fix the uitest `enum_clike_unportable_variant`
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: none
fix "derivable_impls: attributes are ignored"
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`derivable_impls`]: allow the lint when the trait-impl methods has any attribute.
Added new lint: `reserve_after_initialization`
Closes https://github.com/rust-lang/rust-clippy/issues/11330.
A new lint that informs the user about a more concise way to create a vector with a known capacity.
Example:
```rust
let mut v: Vec<usize> = vec![];
v.reserve(10);
```
Produces the following help:
```rust
|
2 | / let mut v: Vec<usize> = vec![];
3 | | v.reserve(10);
| |__________________^ help: consider using `Vec::with_capacity(space_hint)`: `let v: Vec<usize> = Vec::with_capacity(10);`
|
```
And can be rewritten as:
```rust
let v: Vec<usize> = Vec::with_capacity(10);
```
changelog: new lint [`reserve_after_initialization`]
Fix tuple_array_conversions lint on nightly
```
changelog: ICE: [`tuple_array_conversions`]: Don't expect array length to always be usize
```
tl;dr: changed [`Const::eval_target_usize`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_middle/src/ty/consts.rs#L359) to [`Consts::try_eval_target_usize`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_middle/src/ty/consts.rs#L327) to get rid of ICE.
I have encountered a problem with clippy: it caught ICE when working with a codebase that uses a lot of nightly features.
Here's a (stripped) ICE info:
```
error: internal compiler error: /rustc/5c6a7e71cd66705c31c9af94077901a220f0870c/compiler/rustc_middle/src/ty/consts.rs:361:32: expected usize, got Const { ty: usize, kind: N/#1 }
thread 'rustc' panicked at /rustc/5c6a7e71cd66705c31c9af94077901a220f0870c/compiler/rustc_errors/src/lib.rs:1635:9:
Box<dyn Any>
stack backtrace:
...
16: 0x110b9c590 - rustc_middle[449edf845976488d]::util:🐛:bug_fmt
17: 0x102f76ae0 - clippy_lints[71754038dd04c2d2]::tuple_array_conversions::all_bindings_are_for_conv
...
```
I don't really know what's going on low-level-wise, but seems like this lin assumed that the length of the array can always be treated as `usize`, and *I assume* this doesn't play well with `feat(generic_const_exprs)`.
I wasn't able to build a minimal reproducible example, but locally this fix does resolve the issue.
key idea:
for `f` in `.map(f)` and `.for_each(f)`:
1. `f` must be a closure with one parameter
2. don't lint if mutable paramter in clsure `f`: `|mut x| ...`
3. don't lint if parameter is moved
[new_without_default]: include `where` clause in suggestions, make applicable
changelog: [`new_without_default`]: include `where` clause in suggestions
Correctly handle async blocks for NEEDLESS_PASS_BY_REF_MUT
Fixes https://github.com/rust-lang/rust-clippy/issues/11299.
The problem was that the `async block`s are popping a closure which we didn't go into, making it miss the mutable access to the variables.
cc `@Centri3`
changelog: none
[`useless_conversion`]: only lint on paths to fn items and fix FP in macro
Fixes#11065 (which is actually two issues: an ICE and a false positive)
It now makes sure that the function call path points to a function-like item (and not e.g. a `const` like in the linked issue), so that calling `TyCtxt::fn_sig` later in the lint does not ICE (fixes https://github.com/rust-lang/rust-clippy/issues/11065#issuecomment-1616836099).
It *also* makes sure that the expression is not part of a macro call (fixes https://github.com/rust-lang/rust-clippy/issues/11065#issuecomment-1616919639). ~~I'm not sure if there's a better way to check this other than to walk the parent expr chain and see if any of them are expansions.~~ (edit: it doesn't do this anymore)
changelog: [`useless_conversion`]: fix ICE when call receiver is a non-fn item
changelog: [`useless_conversion`]: don't lint if argument is a macro argument (fixes a FP)
r? `@llogiq` (reviewed #10814, which introduced these issues)
Correctly handle async blocks for NEEDLESS_PASS_BY_REF_MUT
Fixes https://github.com/rust-lang/rust-clippy/issues/11299.
The problem was that the `async block`s are popping a closure which we didn't go into, making it miss the mutable access to the variables.
cc `@Centri3`
changelog: none
[`useless_conversion`]: only lint on paths to fn items and fix FP in macro
Fixes#11065 (which is actually two issues: an ICE and a false positive)
It now makes sure that the function call path points to a function-like item (and not e.g. a `const` like in the linked issue), so that calling `TyCtxt::fn_sig` later in the lint does not ICE (fixes https://github.com/rust-lang/rust-clippy/issues/11065#issuecomment-1616836099).
It *also* makes sure that the expression is not part of a macro call (fixes https://github.com/rust-lang/rust-clippy/issues/11065#issuecomment-1616919639). ~~I'm not sure if there's a better way to check this other than to walk the parent expr chain and see if any of them are expansions.~~ (edit: it doesn't do this anymore)
changelog: [`useless_conversion`]: fix ICE when call receiver is a non-fn item
changelog: [`useless_conversion`]: don't lint if argument is a macro argument (fixes a FP)
r? `@llogiq` (reviewed #10814, which introduced these issues)
Use ui_test's Windows path backslash heuristic
changelog: none
Instead of unconditionally replacing `\` with `/` we now use [`Match::PathBackslash`](https://docs.rs/ui_test/latest/ui_test/enum.Match.html#variant.PathBackslash) to only replace backslashes in paths that look like windows paths
`ui-toml` and `ui-cargo` tests still use the old way because they produce verbatim paths on windows in some tests (`\\?\C:\foo\...`) which was finnicky to get the replacement order correct with
Also removes the `ui_test` -> `compiletest` alias and `VarGuard`
redundant_locals: fix FPs on mutated shadows
Fixes#11290.
When a mutable binding is shadowed by
a mutable binding of the same name in a different scope, mutations in that scope have different meaning.
This PR fixes spurious `redundant_locals` emissions on such locals.
cc `@Centri3,` `@flip1995`
changelog: [`redundant_locals`]: fix false positives on mutated shadows
Rustup
r? `@ghost`
cc `@max-niederman` With the latest sync, I'm getting a lot of FP in the `redundant_locals` lint you recently added. Any ideas where this could come from?
changelog: none
When a mutable binding is shadowed by
a mutable binding of the same name in a different scope,
mutations in that scope have different meaning.
This commit fixes spurious `redundant_locals` emissions
on such locals.
[`redundant_guards`]: don't lint on float literals
Fixes#11304
changelog: [`redundant_guards`]: don't lint on float literals
r? `@Centri3` i figured you are probably a good reviewer for this since you implemented the lint ^^
redundant_type_annotations: only pass certain def kinds to type_of
Fixes#11190Fixesrust-lang/rust#113516
Also adds an `is_lint_allowed` check to skip the lint when it's not needed
changelog: none
Fix `suspicious_xor_used_as_pow.rs` performance
The original `suspicious_xor_used_as_pow` lint had poor performance, so I fixed that + a little refactor so that module is readable.
**107 millis. -> 106 millis.** Using `SPEEDTEST` on Rust's VMs
fix#11060
changelog: [`suspicious_xor_used_as_pow`]: Improve performance by 0.934%
New lint `ignored_unit_patterns`
This idea comes from #11238. I've put the lint in `pedantic` as it might trigger numerous positives (three in Clippy itself).
changelog: [`ignored_unit_patterns`]: new lint
Suppress `question_mark` warning if `question_mark_used` is not allowed
Closes#11283
changelog: [`question_mark`]: Don't lint if `question_mark_used` is not allowed
Rename and allow `cast_ref_to_mut` lint
This PR is a small subset of https://github.com/rust-lang/rust/pull/112431, that is the renaming of the lint (`cast_ref_to_mut` -> `invalid_reference_casting`).
BUT also temporarily change the default level of the lint from deny-by-default to allow-by-default until https://github.com/rust-lang/rust/pull/112431 is merged.
r? `@Nilstrieb`
new lint: [`readonly_write_lock`]
Closes#8555
A new lint that catches `RwLock::write` calls to acquire a write lock only to read from it and not actually do any writes (mutations).
changelog: new lint: [`readonly_write_lock`]
Now `option_env_unwrap` warns even if a variable isn't set at compiletime
Fixes#10742
changelog: Fix false negative where `option_env_unwrap` wouldn't warn if the env variable isn't set at compile-time.
[`slow_vector_initialization`]: catch `Vec::new()` followed by `.resize(len, 0)`
Closes#10938
changelog: [`slow_vector_initialization`]: catch `Vec::new()` followed by `.resize(len, 0)`
New lint [`needless_return_with_try`]
Closes#10902
Rather than having a config option, this will just suggest removing the "return"; if `try_err` is used as well, then it'll be added again but without the `?`.
changelog: New lint [`needless_return_with_try`]
ptr_arg should ignore extern functions
Fixes: #11181
changelog: [`ptr_arg`]: ignore extern functions that are not
I am not sure whether we should ignore other Rust calling conventions like `rust-intrinsic`, `rust-call` or `rust-cold`.
`unwrap_or_else_default` -> `unwrap_or_default` and improve resulting lint
Resolves#10080 (though it doesn't implement exactly what's described there)
This PR does the following:
1. Merges `unwrap_or_else_default.rs`'s code into `or_fun_call.rs`
2. Extracts the code to handle `unwrap_or(/* default value */)` and similar, and moves it into `unwrap_or_else_default`
3. Implements the missing functionality from #9342, e.g.,, to handle `or_insert_with(Default::default)`
4. Renames `unwrap_or_else_default` to `unwrap_or_default` (since the "new" lint handles both `unwrap_or` and `unwrap_or_else`, it seemed sensible to use the shortened name)
This PR is currently two commits. The first implements 1-3, the second implements 4.
A word about 2: the `or_fun_call` lint currently produces warnings like the following:
```
error: use of `unwrap_or` followed by a call to `new`
--> $DIR/or_fun_call.rs:56:14
|
LL | with_new.unwrap_or(Vec::new());
| ^^^^^^^^^^^^^^^^^^^^^ help: try: `unwrap_or_default()`
```
To me, such warnings look like they should come from `unwrap_or_else_default`, not `or_fun_call`, especially since `or_fun_call` is [in the nursery](https://github.com/rust-lang/rust-clippy/pull/9829).
---
changelog: Move: Renamed `unwrap_or_else_default` to [`unwrap_or_default`]
[#10120](https://github.com/rust-lang/rust-clippy/pull/10120)
changelog: Enhancement: [`unwrap_or_default`]: Now handles more functions, like `or_insert_with`
[#10120](https://github.com/rust-lang/rust-clippy/pull/10120)
<!-- changelog_checked-->
check that the types are equal in `SpanlessEq::eq_expr`
Fixes#11213
changelog: [`if_same_then_else`]: don't lint for integer literals of different types
Fix async functions handling for `needless_pass_by_ref_mut` lint
Fixes https://github.com/rust-lang/rust-clippy/issues/11179.
The problem with async is that "internals" are actually inside a closure from the `ExprUseVisitor` point of view, meaning we need to actually run the check on the closures' body as well.
changelog: none
r? `@llogiq`
Make `comparison_to_empty` work on `if let`/`let` chains
This adds `LetChain` to `clippy_utils::higher`, other lints may benefit from such a change as well :D
changelog: Enhancement: [`comparison_to_empty`]: Now lints on `if let`
[`unused_async`]: don't lint if paths reference async fn without immediate call
Fixes#9695Fixes#9359
Clippy shouldn't lint unused `async` if there are paths referencing them if that path isn't the receiver of a function call, because that means that the function might be passed to some other function:
```rs
async fn f() {} // No await statements, so unused at this point
fn requires_fn_future<F: Future<Output = ()>>(_: fn() -> F) {}
requires_fn_future(f); // `f`'s asyncness is actually not unused.
```
(This isn't limited to just passing the function as a parameter to another function, it could also first be stored in a variable and later passed to another function as an argument)
This requires delaying the linting until post-crate and collecting path references to local async functions along the way.
changelog: [`unused_async`]: don't lint if paths reference async fn that require asyncness
fix dogfood lints in `redundant_local`
keep `redundant_local` from running in proc macros
rewrite `redundant_local` as late pass
make redundant_local's `find_binding` more readable
pluralize `redundant_locals` name
add test for `redundant_locals` in macros
test `redundant_locals` in proc macros
use more destructuring in `redundant_locals`
fix: format redundant_locals.rs
ignore needless_pass_by_mut_ref in redundant_locals test
Allow `Self::cmp(self, other)` as a correct impl
Fixes#11178
Also no longer checks if the method name is *just* cmp, but the path. That was an oversight on my part ^^
r? `@xFrednet`
(and `@blyxyas` too!)
changelog: [`incorrect_partial_ord_impl_on_ord_type`]: Now allows non-method calls to `cmp` like `Self::cmp(self, other)`
fix: false positive for `option_env!` in `ifs_same_cond`
Clippy had a false positive for with `ifs_same_cond` when two if-let expressions have an `option_env!` macro. The fix is similar to the `env!` macro fix.
The following example had a clippy error:
```rust
if let Some(env1) = option_env!("ENV1") {
// ...
} else if let Some(env2) = option_env!("ENV2") {
// ...
}
```
See https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=01b85c61b56ddd900117fb247af04824
changelog: [`ifs_same_cond`]: fix false positive when using `option_env!` in if-let expressions.
[`unnecessary_literal_unwrap`]: Fix ICE on None.unwrap_or_default()
Fixes#11099Fixes#11064
I'm running into #11099 (cc `@y21)` on my Rust codebase. Clippy ICEs on this code when evaluating the `unnecessary_literal_unwrap` lint:
```rust
fn main() {
let val1: u8 = None.unwrap_or_default();
}
```
This fixes that ICE and adds an message specifically for that case:
```
error: used `unwrap_or_default()` on `None` value
--> $DIR/unnecessary_literal_unwrap.rs:26:5
|
LL | None::<String>.unwrap_or_default();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the `None` and `unwrap_or_default()`: `String::default()`
```
This PR also fixes the same ICE with `None.unwrap_or_else` (by giving the generic error message for the lint in that case).
changelog: Fix ICE in `unnecessary_literal_unwrap` on `None.unwrap_or_default()`
Clippy had a false positive for with `ifs_same_cond` when two
if-let expressions have an `option_env!` macro. The fix is similar to the
`env!` macro fix.
The following example had a clippy error:
```rust
if let Some(env1) = option_env!("ENV1") {
// ...
} else if let Some(env2) = option_env!("ENV2") {
// ...
}
```
See https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=01b85c61b56ddd900117fb247af04824
changelog: Fix [`ifs_same_cond`] false positive when using `option_env!` in if-let expressions.
[`manual_filter_map`]: lint on `matches` and pattern matching
Fixes#8010
Previously this lint only worked specifically for a very limited set of methods on the filter call (`.filter(|opt| opt.is_some())` and `.filter(|res| res.is_ok())`). This PR extends it to also recognize `matches!` in the `filter` and pattern matching with `if let` or `match` in the `map`.
Example:
```rs
enum Enum {
A(i32),
B,
}
let _ = [Enum::A(123), Enum::B].into_iter()
.filter(|x| matches!(x, Enum::A(_)))
.map(|x| if let Enum::A(s) = x { s } else { unreachable!() });
```
Now suggests:
```diff
- .filter(|x| matches!(x, Enum::A(_))).map(if let Enum::A(s) = x { s } else { unreachable!() })
+ .filter_map(|x| match x { Enum::A(s) => Some(s), _ => None })
```
Adding this required a somewhat large change in code because it originally seemed to be specifically written with only method calls in the filter in mind, and `matches!` has different behavior in the map, so this new setup should make it possible to support more "generic" cases that need different handling for the filter and map calls.
changelog: [`manual_filter_map`]: lint on `matches` and pattern matching (and some internal refactoring)
Fix `unwrap_or_else_default` false positive
This PR fixes a false positive in the handling of `unwrap_or_else` with a default value when the value is needed for type inference.
An easy example to exhibit the false positive is the following:
```rust
let option = None;
option.unwrap_or_else(Vec::new).push(1);
```
The following code would not compile, because the fact that the value is a `Vec` has been lost:
```rust
let option = None;
option.unwrap_or_default().push(1);
```
The fix is to:
- implement a heuristic to tell whether an expression's type can be determined purely from its subexpressions, and the arguments and locals they use;
- apply the heuristic to `unwrap_or_else`'s receiver.
The heuristic returns false when applied to `option` in the above example, but it returns true when applied to `option` in either of the following examples:
```rust
let option: Option<Vec<u64>> = None;
option.unwrap_or_else(Vec::new).push(1);
```
```rust
let option = None::<Vec<u64>>;
option.unwrap_or_else(Vec::new).push(1);
```
(Aside: https://github.com/rust-lang/rust-clippy/pull/10120 unfairly contained multiple changes in one PR. I am trying to break that PR up into smaller pieces.)
---
changelog: FP: [`unwrap_or_else_default`]: No longer lints if the default value is needed for type inference
Rewrite [`tuple_array_conversions`]
Fixes#11100Fixes#11144Fixes#11124#11082 still needs discussion and #11085 likely can't be fixed.
changelog: [`tuple_array_conversions`]: Move to `pedantic`
changelog: [`tuple_array_conversions`]: Don't lint if mutability of references changes
changelog: [`tuple_array_conversions`]: Don't lint if bindings don't come from the exact same pattern
changelog: [`tuple_array_conversions`]: Don't lint if bindings are used for more than just the conversion
Add `imports_granularity = "Module"` to rustfmt.toml
This lets rustfmt split/merge imports, `Module` seems to be the most common style in clippy
https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#imports_granularity
changelog: none
Almost all the updates other than the config file change are from `cargo dev fmt` or blessed tests, the exceptions being
- `tests/ui/single_component_path_imports.rs`
- `tests/ui/single_component_path_imports_nested_first.rs`
- `tests/ui/single_component_path_imports_self_after.rs`
- `tests/ui/single_component_path_imports_self_before.rs`
- `tests/ui/unsafe_removed_from_name.rs` (added a test with merged imports as a drive by)
- `tests/ui/wildcard_imports.rs`
- `tests/ui/wildcard_imports_2021.rs`
[`arithmetic_side_effect`]: allow different types on the right hand side for `Wrapping<T>`
Fixes#11145
This lint has a list of allowed types, one of which is `Wrapping<T>`, but it was only actually allowed if the type on the right hand side was also `Wrapping<T>`, which meant that, for example, `Wrapping<u32> += u32` would still lint. It now allows binary ops involving `Wrapping<T>` regardless of the type on the rhs.
These impls have only existed since Rust 1.60.0, so that is probably why the lint was previously not handling this correctly
changelog: [`arithmetic_side_effect`]: allow different types on the right hand side for `Wrapping<T>` (e.g. `Wrapping<T> += T`)
This commit fixes#11025 by removing checks for `todo!`,
`unimplemented!` and `unreachable!`.
Signed-off-by: Panagiotis Foliadis <pfoliadis@hotmail.com>
Uplift `clippy::fn_null_check` lint
This PR aims at uplifting the `clippy::fn_null_check` lint into rustc.
## `incorrect_fn_null_checks`
(warn-by-default)
The `incorrect_fn_null_checks` lint checks for expression that checks if a function pointer is null.
### Example
```rust
let fn_ptr: fn() = /* somehow obtained nullable function pointer */
if (fn_ptr as *const ()).is_null() { /* ... */ }
```
### Explanation
Function pointers are assumed to be non-null, checking for their nullity is incorrect.
-----
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
[`unnecessary_literal_unwrap`]: don't lint if binding initializer comes from expansion
Fixes https://github.com/rust-lang/rust-clippy/discussions/11109
changelog: [`unnecessary_literal_unwrap`]: don't lint if binding initializer comes from expansion
"try this" -> "try"
Current help messages contain a mix of "try", "try this", and one "try this instead". In the spirit of #10631, this PR adopts the first, as it is the most concise.
It also updates the `lint_message_conventions` test to catch cases of "try this".
(Aside: #10120 unfairly contained multiple changes in one PR. I am trying to break that PR up into smaller pieces.)
changelog: Make help messages more concise ("try this" -> "try").
Add `needless_pass_by_ref_mut` lint
changelog: [`needless_pass_by_ref_mut`]: This PR add a new lint `needless_pass_by_ref_mut` which emits a warning in case a `&mut` function argument isn't used mutably. It doesn't warn on trait and trait impls functions.
Fixes#8863.
cargo dev fmt
cargo test passes
cargo test passes
refactor a lil
Update bool_comparison.stderr
heavily refactor + bump `clippy::version`
refactor
refactor
check bounds to increase accuracy, and add todos
new lint: `read_line_without_trim`
This adds a new lint that checks for calls to `Stdin::read_line` with a reference to a string that is then attempted to parse into an integer type without first trimming it, which is always going to fail at runtime.
This is something that I've seen happen a lot to beginners, because it's easy to run into when following the example of chapter 2 in the book where it shows how to program a guessing game.
It would be nice if we could point beginners to clippy and tell them "let's see what clippy has to say" and have clippy explain to them why it fails 👀
I think this lint can later be "generalized" to work not just for `Stdin` but also any `BufRead` (which seems to be where the guarantee about the trailing newline comes from) and also, matching/comparing it to a string slice that doesn't end in a newline character (e.g. `input == "foo"` is always going to fail)
changelog: new lint: [`read_line_without_trim`]
[`useless_vec`]: add more tests and don't lint inside of macros
Closes#11084.
I realized that the fix I added in #11081 itself also causes an error in a suggestion when inside of a macro. Example:
```rs
macro_rules! x {
() => {
for _ in vec![1, 2] {}
}
}
x!();
```
Here it would suggest replacing `vec![1, 2]` with `[x!()]`, because that's what the source callsite is (reminder: it does this to get the correct span of `x!()` for code like `for _ in vec![x!()]`), but that's wrong when *inside* macros, so I decided to make it not lint if the whole loop construct is inside a macro to avoid this issue.
changelog: [`useless_vec`]: add more tests and don't lint inside of macros
r? `@Alexendoo` since these were your tests, I figured it makes most sense to assign you
Don't lint manual_let_else in cases where ? would work
Don't lint `manual_let_else` where the question mark operator `?` would be sufficient, that is, mostly in cases like:
```Rust
let v = if let Some(v) = ex { v } else { return None };
```
Also, this PR emits the `question_mark` lint for `let...else` patterns that could be written with `?` (also, only `return None` like cases).
```
changelog: [`manual_let_else`]: don't lint in cases where question_mark already lints
changelog: [`question_mark`]: lint for `let Some(...) = ex else { return None };`
```
Fixes #8755
[`useless_vec`]: use the source span for initializer
Fixes#11075.
changelog: [`useless_vec`]: use the source span for the initializer expression when inside of a macro
[`arc_with_non_send_sync`]: don't lint if type has nested type parameters
Fixes#11076
changelog: [`arc_with_non_send_sync`]: don't lint if type has nested type parameters
r? `@Manishearth`
new lint: `type_id_on_box`
Closes#7687.
A new lint that detects calling `.type_id()` on `Box<dyn Any>` (and not on the underlying `dyn Any`), which can make up for some pretty confusing bugs!
changelog: new lint: [`type_id_on_box`]
`let_and_return`: lint 'static lifetimes, don't lint borrows in closures
Fixes#11056
Now also ignores functions returning `'static` lifetimes, since I noticed the `stdin.lock()` example was still being linted but doesn't need to be since https://github.com/rust-lang/rust/pull/93965
changelog: none
New lint [`tuple_array_conversions`]
Closes#10748
PS, the implementation is a bit ugly 😅 ~~I will likely refactor soon enough :)~~ Done :D
changelog: New lint [`tuple_array_conversions`]
Also, lint question_mark for `let...else` clauses that can be simplified to use `?`.
This lint isn't perfect as it doesn't support the unstable try blocks.
[significant_drop_tightening] Fix#10413Fix#10413
This is quite a rewrite that unfortunately took a large amount of time. I tried my best to comment what is going on to easy review but feel free to ask any question.
The problem basically is that the current algorithm is only taking into consideration single blocks which means that things like the following don't work or show unpredictable results.
```rust
let mutex = Mutex::new(1);
{
let lock = mutex.lock().unwrap();
{
let _ = *lock;
}
}
```
The solve the issue, each path that refers a lock is now being tracked individually.
```
changelog: [`significant_drop_tightening`]: Lift the restriction of only considerate single blocks
```
New lint [`redundant_at_rest_pattern`]
Closes#11011
It's always a great feeling when a new lint triggers on clippy itself 😄
changelog: New lint [`redundant_at_rest_pattern`]
suggests `is_some_and` over `map().unwrap`
changelog: Enhancement: [`option_map_unwrap_or`] now considers the [`msrv`] config when creating the suggestion.
* modified option_map_unwrap_or lint to recognise when an `Option<T>` is mapped to an `Option<bool>` with false being used when `None` is detected; suggests the use of `is_some_and` instead
* msrv is set to 1.70.0 for this lint; when `is_some_and` was stabilised
fixes#9125
[`question_mark`]: don't lint inside of `try` block
Fixes#8628.
Diff looks a bit noisy because I had to move the two functions into an impl, because they now need to access the structs `try_block_depth` field to see if they're inside a try block.
changelog: [`question_mark`]: don't lint inside of `try` block
[`option_if_let_else`]: suggest `.as_ref()` if scrutinee is of type `&Option<_>`
Fixes#10729
`Option::map_or` takes ownership, so if matching on an `&Option<_>`, we need to suggest `.as_ref()` before calling `map_or` to get the same effect and to not cause a borrowck error.
changelog: [`option_if_let_else`]: suggest `.as_ref()`/`.as_mut()` if scrutinee is of type `&Option<_>`/`&mut Option<_>`
[`unused_async`]: don't lint if function is part of a trait
Fixes#10459.
We shouldn't lint if the function is part of a trait, because the user won't be able to easily remove the `async`, as this will then not match with the function signature in the trait definition
changelog: [`unused_async`]: don't lint if function is part of a trait
Port clippy away from compiletest to ui_test
Reasons to do this:
* runs completely on stable Rust
* is easier to extend with new features
* has its own dogfood test suite, so changes can be tested in [the `ui_test` repo](https://github.com/oli-obk/ui_test)
* supports dependencies from crates.io without having to manually fiddle with command line flags
* supports `ui-cargo`, `ui`, `ui-toml` out of the box, no need to find and run the tests ourselves
One thing that is a big difference to `compiletest` is that if a test emits *any* error, you need to mark all of them with `//~ ERROR:` annotations. Since many clippy tests did not have annotations, I changed many lints to be `warn` in their test so that only the `stderr` output is tested.
TODO:
* [ ] check that this still works as a subtree in the rustc repo
changelog: none
<!-- changelog_checked -->
Note: at present the latest changes needed for clippy are only available as a git dependency, but I expect to publish a new crates.io version soon
Check if `if` conditions always evaluate to true in `never_loop`
This fixes the example provided in #11004, but it shouldn't be closed as this is still an issue on like
```rust
let x = true;
if x { /* etc */ }`
```
This also makes `clippy_utils::consts::constant` handle `ConstBlock` and `DropTemps`.
changelog: [`never_loop`]: Check if `if` conditions always evaluate to true
Lint `mem_forget` if any fields are `Drop`
Closes#9298
I think this way of doing it (`needs_drop`) should be fine.
---
changelog: Enhancement: [`mem_forget`]: Now lints on types with fields that implement `Drop`
[#10996](https://github.com/rust-lang/rust-clippy/pull/10996)
[`format_push_string`]: look through `match` and `if` expressions
Closes#9493.
changelog: [`format_push_string`]: look through `match` and `if` expressions
[`get_unwrap`]: include a borrow in the suggestion if argument is not an integer literal
Fixes#9909
I have to say, I don't really understand what the previous logic was trying to do, but this fixes the linked bug.
It was checking if the argument passed to `.get()` can be parsed as a usize (i.e. if it's an integer literal, probably?), and if not, it wouldn't include a borrow? I don't know how we came to that conclusion, but that logic doesn't work:
```rs
let slice = &[1, 2];
let _r: &i32 = slice.get({ 1 }).unwrap();
// previous suggestion: slice[{ 1 }]
// the suggestion should be: &slice[{ 1 }]
```
Here the argument passed to it isn't an integer literal, but it should still include a borrow, because it would otherwise change the type from `&i32` to `i32`.
The exception is that if the parent of the `get().unwrap()` expr is a dereference or a method call or the like, we don't need an explicit borrow because it's automatically inserted by the compiler
changelog: [`get_unwrap`]: include a borrow in the suggestion if argument is not an integer literal
Don't lint [`iter_nth_zero`] in `next`
Closes#9820
This also *slightlyy* modifies the output of `iter_nth`, as I noticed the types' names weren't in backticks
changelog: [`iter_nth_zero`]: No longer lints in implementations of `Iterator::next`
[`single_match`]: don't lint if block contains comments
Fixes#8634
It now ignores matches with a comment in the "else" arm
changelog: [`single_match`]: don't lint if block contains comments
[`redundant_closure_call`]: handle nested closures
Fixes#9956.
This ended up being a much larger change than I'd thought, and I ended up having to pretty much rewrite it as a late lint pass, because it needs access to certain things that I don't think are available in early lint passes (e.g. getting the parent expr). I think this'll be required to fi-x #10922 anyway, so this is probably fine.
(edit: had to write "fi-x" because "fix" makes github think that this PR fixes it, which it doesn't 😅 )
Previously, it would suggest changing `(|| || 42)()()` to `|| 42()`, which is a type error (it needs parens: `(|| 42)()`). In my opinion, though, the suggested fix should have really been `42`, so that's what this PR changes.
changelog: [`redundant_closure_call`]: handle nested closures and rewrite as a late lint pass
[`arithmetic_side_effects`] Fix#10792Fix#10792
```
changelog: [`arithmetic_side_effects`]: Retrieve field values of structures that are in constant environments
```
Ignore more type aliases in `unnecessary_cast`
This is potentially the worst code I've ever written, and even if not, it's very close to being on par with starb. This will ignore `call() as i32` and `local_obtained_from_call as i32` now.
This should fix every reasonable way to reproduce #10555, but likely not entirely.
changelog: Ignore more type aliases in `unnecessary_cast`
[`missing_panics_doc`]: pickup expect method
close#10240
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`missing_panics_doc`]: pickup expect method
new lint: `drain_collect`
Closes#10818.
This adds a new lint that looks for `.drain(..).collect()` and suggests replacing it with `mem::take`.
changelog: [`drain_collect`]: new lint
[`match_same_arms`]: don't lint if `non_exhaustive_omitted_patterns`
Fixes#10327
changelog: [`match_same_arms`]: Don't lint if `non_exhaustive_omitted_patterns` is `warn` or `deny`
from_over_into: Show suggestions for non-Self expanded paths
changelog: [`from_over_into`]: Show suggestions when the body contains macros not expanding to `Self`
Currently any path in a macro expansion causes the suggestion to be hidden, meaning most macro calls cause it to be hidden
Now it's only hidden if the expansion contains `Self`
[`unnecessary_fold`]: suggest turbofish if necessary
Fixes#10000
This adds turbofish `::<T>` to the suggestion in `unnecessary_fold`. This is necessary because the `Sum` trait is generic, which breaks inference when changing `fold()` to `sum()`.
changelog: [`unnecessary_fold`]: suggest turbofish if necessary
new lint [`single_range_in_vec_init`]
Lints on `vec![0..200]` (or `[0..200]`), suggesting either `(0..200).collect::<Vec<i32>>()` or `[0; 200]`.
Haven't tested it with anything that isn't primitive. Probably should!
Closes#10932
changelog: new lint [`single_range_in_vec_init`]
[`derivable_impls`]: don't lint if `default()` call expr unsize-coerces to trait object
Fixes#10158.
This fixes a FP where the derive-generated Default impl would have different behavior because of unsize coercion from `Box<T>` to `Box<dyn Trait>`:
```rs
struct S {
x: Box<dyn std::fmt::Debug>
}
impl Default for S {
fn default() -> Self {
Self {
x: Box::<()>::default()
// ^~ Box<()> coerces to Box<dyn Debug>
// #[derive(Default)] would call Box::<dyn Debug>::default()
}
}
}
```
(this intentionally only looks for trait objects `dyn` specifically, and not any unsize coercion, e.g. `&[i32; 5]` to `&[i32]`, because that breaks existing tests and isn't actually problematic, as far as I can tell)
changelog: [`derivable_impls`]: don't lint if `default()` call expression unsize-coerces to trait object
[`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
Improve suggestion for [`needless_lifetimes`]
Fixes#10093
changelog: [`needless_lifetimes`]: Suggestion now points at the elidable lifetimes, rather than the entire function declaration
[`missing_const_for_fn`]: Ensure dropped locals are `~const Destruct`
this will check every local for `TerminatorKind::Drop` to ensure they can be evaluated at compile time, not sure if this is the best way to do this but MIR is confusing and it works so...
fixes#10617
changelog: [`missing_const_for_fn`]: Ensure dropped locals are `~const Destruct`
[`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
