Partial no-op refactoring of #9948
This contains some prep work for #9948 to keep that change to the minimum, and make it easier to review it.
This should be a noop, but it has some tests from that PR discussion, and should help in the future with the corner case format handling.
cc: `@Alexendoo` `@llogiq` `@xFrednet` as the 3 people who reviewed the parent PR
----
changelog: none
Add suggestions to `extra_unused_type_parameters`
Change the `extra_unused_type_parameters` lint to provide machine applicable suggestions rather than just help messages. Exception to this are cases when any unused type parameters appear bounded in where clauses - for now I've deemed these cases unfixable and separated them out. Future work might be able to provide suggestions in these cases.
Also, added a test case for the `avoid_breaking_exported_api` config option.
r? `@flip1995`
changelog: [`extra_unused_type_parameters`]: Now provides fixable suggestions.
Added the `[unnecessary_box_returns]` lint
fixes#5
I'm not confident in the name of this lint. Let me know if you can think of something better
---
changelog: New lint: ``[`unnecessary_box_returns`]``
[#9102](https://github.com/rust-lang/rust-clippy/pull/9102)
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In uninit checking, add fallback for polymorphic types
After #10520, we always assumed that polymorphic types do not allow to be left uninitialized. But we can do better, by peeking into polymorphic types and adding a few special cases for going through tuples, arrays (because the length may be polymorphic) and blanket allowing all unions (like MaybeUninit).
fixes#10551
changelog: [uninit_vec]: fix false positive for polymorphic types
changelog: [uninit_assumed_init]: fix false positive for polymorphic types
Fix allow attribute, items from macros in `items_after_statements`
Fixes#10540
changelog: [`items_after_statements`]: Fixes `#[allow(clippy::items_after_statements)]` when applied to an item, and ignores items after statements from different macro contexts
fix [`cast_possible_truncation`] offering wrong suggestion for casting float to integer
fixes: #10366
---
changelog: [`cast_possible_truncation`] Fix incorrect suggestions when casting from float types or to `_`
Wrap `transmutes_expressible_as_ptr_casts` suggestions in parentheses
changelog: [`transmutes_expressible_as_ptr_casts`]: Fix suggestion missing wrapping parentheses
Fixes#10449
r? `@Jarcho`
Is this the best way to go about this? `unused_parens` will catch the unnecessary ones but emitting them in the first place isn't ideal
suggest `try_into` when casting to wildcard type;
fix [`cast_possible_truncation`] suggesting useless parenthesis;
remove suggesting for float to float conversion in [`cast_possible_truncation`]
style nit
New lint: detect unnecessary struct building
Fixes#10476.
Running this lint on the top 500 crates produced one hit (in `rust-lang/rust-bindgen`) and [a PR has been submitted there](https://github.com/rust-lang/rust-bindgen/pull/2440).
changelog: [`unnecessary_struct_initialization`]: new lint
Do not propose to simplify a not expression coming from a macro
Fixes#10523
changelog: FP [`nonminimal_bool`]: do not propose to change code coming from a macro
Do not propose to remove `async move` if variables are captured by ref
Fixes#10482
changelog: FP [`redundant_async_block`] Do not propose to remove `async move` if variables are captured by ref
rustc has proper heuristics for actually checking whether a type allows
being left uninitialized (by asking CTFE). We can now use this for our
helper instead of rolling our own bad version with false positives.
Issue function modifiers in the right order in manual_async_fn lint
Fixes#10450
changelog: [`manual_async_fn`] output function modifiers in correct order
fix `almost_swapped`: Ignore external macros
Fixes#10421 ; Related to #10499 (Fixing points *1* and *3* from #10421)
changelog: [`almost_swapped`]: Add a check to ignore external macros
Fix `almost_swapped` false positive (`let mut a = b; a = a`)
Fixes `2` in #10421
changelog: [`almost_swapped`]: Fix false positive when a variable is changed to itself. (`a = a`)
Remove `identity_future` indirection
This was previously needed because the indirection used to hide some unexplained lifetime errors, which it turned out were related to the `min_choice` algorithm.
Removing the indirection also solves a couple of cycle errors, large moves and makes async blocks support the `#[track_caller]`annotation.
Fixes https://github.com/rust-lang/rust/issues/104826.
enhance [`ifs_same_cond`] to warn same immutable method calls as well
fixes: #10272
---
changelog: Enhancement: [`ifs_same_cond`]: Now also detects immutable method calls.
[#10350](https://github.com/rust-lang/rust-clippy/pull/10350)
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Remove `box_syntax`
r? `@Nilstrieb`
This removes the feature `box_syntax`, which allows the use of `box <expr>` to create a Box, and finalises removing use of the feature from the compiler. `box_patterns` (allowing the use of `box <pat>` in a pattern) is unaffected.
It also removes `ast::ExprKind::Box` - the only way to create a 'box' expression now is with the rustc-internal `#[rustc_box]` attribute.
As a temporary measure to help users move away, `box <expr>` now parses the inner expression, and emits a `MachineApplicable` lint to replace it with `Box::new`
Closes#49733
Strengthen state tracking in const-prop
Some/many of the changes are replicated between both the const-prop lint and the const-prop optimization.
Behaviour changes:
- const-prop opt does not give a span to propagated values. This was useless as that span's primary purpose is to diagnose evaluation failure in codegen.
- we remove the `OnlyPropagateInto` mode. It was only used for function arguments, which are better modeled by a write before entry.
- the tracking of assignments and discriminants make clearer that we do nothing in `NoPropagation` mode or on indirect places.
Add utility macros to help with writing tests.
Adds two utility macros to help with testing:
* `external` expands to it's argument tokens, but makes them appear to come from an external macro. Helps make tests for `in_external_macro` much more readable.
* `inline_macros` is an attribute macro which allows the use of a pseudo `inline!` macro which expands to it's argument tokens, but makes them appear to be from a crate-local macro expansion. This removes the need to write `macro_rules` boilerplate when testing how lints interact with macros.
---
`external`'s usage is simple. `external!(struct Foo { x: u32});` will make the struct appear as though it came from an external macro. Individual tokens can be escaped if needed. `external!($x + 0 / 10)` will make everything except `x` appear as though it came from an external macro. Can also use `$literal` and `$(tokens...)` as well.
---
`inline_macros` is more complicated due to compiler constraints. Given:
```rust
#[inline_macros]
fn foo() {
inline!(5 + 5 / 10);
}
```
`inline!(5 + 5 / 10)` will be replace with a call to a generated macro which expands to the contained tokens.
Tokens can be escaped by prefixing them with `$`:
```rust
#[inline_macros]
fn foo() {
let x = 5;
inline!($x + 5 / $10);
}
```
This will pass `x` as an `ident` argument and `10` as a `literal` argument.
Token sequences can also be passed with `$(...)`:
```rust
#[inline_macros]
fn foo() {
let mut x = 5;
inline!(if $(x >= 5) {
$x = 5;
});
}
```
This will pass `x >= 5` as `tt` arguments, and `x` as an `ident` argument.
---
Not 100% sure `inline_macros` is actually worth having. It does make the tests a little easier to read once you're used to it and it becomes more useful once there are multiple macro tests. The verbosity of declaring single use macros starts to hurt at that point.
changelog: None
Improve diagnostic of `no_mangle_with_rust_abi`
fixes#10409
Pending rust-lang/rustfmt#5701
This rewords the message to focus on the error being an implicit ABI, rather than the `Rust` ABI. Also downgrades the suggestion to `MaybeIncorrect` and changes the suggestion span to better highlight the change.
---
changelog: None
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Migrate `write.rs` to `rustc_ast::FormatArgs`
changelog: none
Part 1 of #10233
The additions to `clippy_utils` are the main novelty of this PR, there's no removals yet since other parts still rely on `FormatArgsExpn`
The changes to `write.rs` itself are relatively straightforward this time around, as there's no lints in it that rely on type checking format params
r? `@flip1995`
Include async functions in the len_without_is_empty
fixes#7232
Changes done to the functionality:
Allowing different error types for the functions was disallowed. So the following was linted before but is not after this change
```
impl Foo {
pub len(&self) -> Result<usize, Error1> { todo!(); }
pub is_empty(&self) -> Result<bool, Error2> { todo!(); }
}
```
---
changelog: Enhancement: [`len_without_is_empty`]: Now also detects `async` functions
[#10359](https://github.com/rust-lang/rust-clippy/pull/10359)
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[arithmetic_side_effects] Fix#10252Fix#10252
At least for integers, shifts are already handled by the compiler.
----
changelog: [`arithmetic_side_effects`]: No longer lints on right or left shifts with constant integers, as the compiler warns about them.
[#10309](https://github.com/rust-lang/rust-clippy/pull/10309)
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This was previously needed because the indirection used to hide some unexplained lifetime errors, which it turned out were related to the `min_choice` algorithm.
Removing the indirection also solves a couple of cycle errors, large moves and makes async blocks support the `#[track_caller]` annotation.
Add `collection_is_never_read`
Fixes#9267
`@flip1995` and `@llogiq,` I talked with you about this one at Rust Nation in London last week. :-)
This is my first contribution to Clippy, so lots of feedback would be greatly appreciated.
- \[ ] 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`
`dogfood` found one true positive (see #9509) and no false positives.
`lintcheck` found no (true or false) positives, even when running on an extended set of crates.
---
changelog: new lint [`collection_is_never_read`]
[#10415](https://github.com/rust-lang/rust-clippy/pull/10415)
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Scope `missing_docs_in_private_items` to only private items
`missing_docs_in_private_items` currently detects missing docs for public items as well as private. Since `missing_docs`already covers public items, this PR updates `missing_docs_in_private_items` to only cover private items.
Fixes#1895
changelog: [`missing_docs_in_private_items`]: Apply lint only to private items (used to be public and private)
Fix ICE in `multiple_unsafe_ops_per_block`
fixes#10367
changelog: [`multiple_unsafe_ops_per_block`]: Fix ICE when calling a function-like object in an unsafe block
Do not suggest to derive `Default` on generics with implicit arguments
Fixes#10396
changelog: FP: [`derivable_impls`]: do not suggest to derive `Default` on generics with implicit arguments
chore: remove unneeded rustfmt skip
---
The associated rustfmt bug that originally necessitated these skips was resolved a while back, so these are no longer necessary
changelog: none
Normalize projections types when checking `explicit_auto_deref`
fixes#10384
changelog: [`explicit_auto_deref`]: Better consider projection types when checking if auto deref is applicable
Ignore lifetimes from differing contexts in `needless_lifetimes`
Fixes#10379
changelog: [`needless_lifetimes`]: Don't lint signatures in macros if the lifetime is a metavariable
Add `impl_trait_in_params` lint
As this is a lint about style, and using `impl Trait` is purely cosmetical (even with downsides), a lot of unrelated files needed to allow this lint.
---
Resolves#10030
changelog: New lint: [`impl_trait_in_params`]
[10197](https://github.com/rust-lang/rust-clippy/pull/10197)
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Within a larger expression, when the type of `Box::new(T::default())` is
`Box<dyn Trait>`, the concrete type `T` cannot be omitted in the
proposed replacement `Box::<T>::default()`.
[significant_drop_tightening] Ignore inexpensive statements
Not all statements that follow the last use of a lock guard are expensive and can therefore be ignored by the lint.
```rust
pub fn foo() -> i32 {
let mutex = Mutex::new(1);
let lock = mutex.lock().unwrap();
let rslt = *lock;
let another = rslt;
another
}
```
---
changelog: [`significant_drop_tightening`]: No longer lints for inexpensive statements after the lock guard
[#10363](https://github.com/rust-lang/rust-clippy/pull/10363)
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manual_let_else: do not suggest semantically different replacements
The problem is that this lint does not consider the possibility that the divergent branch can come first and that the patterns may overlap. This led to incorrect suggestions, previously registered as correct in the tests themselves:
```rust
let v = match build_enum() {
_ => continue,
Variant::Bar(v) | Variant::Baz(v) => v,
};
```
had a `let Variant::Bar(v) | Variant::Baz(v) = v else { continue; }` suggestion, which is obviously wrong as the original code `continue`s in any case. Issue #10241 gives another example.
The code now checks that the divergent branch comes second. It could be extended later (I've added a TODO) to check for non-overlapping patterns.
Fixes#10241.
changelog: [`manual_let_else`] do not suggest non equivalent replacements in `match`
Stop bytes_nth from suggesting code that does not compile
Fixes#10151
As discussed in the issue, this PR changes the lint in 2 ways
1. Replace `bytes().nth(n).unwrap()` with `as_bytes()[n]`
2. Replace other `bytes().nth(n)` with `as_bytes().get(n).copied()`
---
changelog: Stop bytes_nth from suggesting code that does not compile in some cases
Stop doc_markdown requiring backticks on links to external websites
Fixes#10302
This lint currently checks that any link should be enclosed with `backticks` if the title looks like a lang item. This PR changes the lint to only run on internal links. External links, indicated by `http` or `https`, are skipped.
This PR also reorganises `pulldown_cmark` imports to bypass the clippy lint enforcing 100 line functions.
---
changelog: Stop doc_markdown requiring backticks on links to external websites
Add question-mark-used lint
This lint complains when the question mark operator (try operator) is used. This is a restriction lint that can be useful on local scopes where a custom error handling macro is supposed to be used to augment the error based on local scope data before returning.
Fixes#10340
---
changelog: New lint [`question_mark_used`]
[#10342](https://github.com/rust-lang/rust-clippy/pull/10342)
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Add `let_underscore_untyped`
Fixes#6842
This adds a new pedantic `let_underscore_untyped` lint which checks for `let _ = <expr>`, and suggests to either provide a type annotation, or to remove the `let` keyword. That way the author is forced to specify the type they intended to ignore, and thus get forced to re-visit the decision should the type of `<expr>` change. Alternatively, they can drop the `let` keyword to truly just ignore the value no matter what.
r? `@llogiq`
changelog: New lint: [let_underscore_untyped]
[significant_drop_tightening] Add MVP
cc #9399
Creates the lint with minimum functionalities, which is a good start IMO.
---
changelog: new lint: [`significant_drop_tightening`]
[#10163](https://github.com/rust-lang/rust-clippy/pull/10163)
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As this is a lint about "style", and a purely cosmetical choice (using `<A: Trait>` over `impl Trait`), a lot of other files needed to be allowed this lint.
Fix false positives for `extra_unused_type_parameters`
Don't lint external macros. Also, if the function body is empty, any type parameters with bounds on them are not linted. Note that only the body needs be empty - this rule still applies if the function takes any arguments.
fixes#10318fixes#10319
changelog: none
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uninlined_format_args: do not inline argument with generic parameters
Fix#10339
---
changelog: FP: [`uninlined_format_args`]: No longer lints for arguments with generic parameters
[#10343](https://github.com/rust-lang/rust-clippy/pull/10343)
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fix [`needless_return`] incorrect suggestion when returning if sequence
fixes: #10049
---
changelog: [`needless_return`]: fix incorrect suggestion on if sequence
Liberate late-bound regions rather than erasing them in `needless_pass_by_value`
changelog: [`needless_pass_by_value`]: fixes an ICE when there are late-bound regions in function arguments that are needlessly passed by value
Fixesrust-lang/rust#107147
r? `@matthiaskrgr`
It is not sufficient to ignore break from a block inside the loop.
Instructions after the break must be ignored, as they are unreachable.
This is also true for all instructions in outer blocks and loops
until the right block is reached.
This lint complains when the question mark operator (try operator)
is used. This is a restriction lint that can be useful on local
scopes where a custom error handling macro is supposed to be used
to augment the error based on local scope data before returning.
Negate suggestions when needed in `bool_assert_comparison`
changelog: none assuming this gets into the same release as #10218Fixes#10291
r? `@dswij`
Thanks to `@black-puppydog` for spotting it early
wildcard_enum_match_arm lint takes the enum origin into account
fixes#7419
---
changelog: Enhancement: [`wildcard_enum_match_arm`]: Now lints missing private variants, for local enums
[#10250](https://github.com/rust-lang/rust-clippy/pull/10250)
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[`unused_io_amount`]: Lint with `is_ok` and `is_err`
Fixes#10132
changelog: Apply [`unused_io_amount`] lint to `is_ok` and `is_err` without checking read/write amount
prevents `len_without_is_empty` from yielding positive when `len` takes arguments besides `&self`
Fixes#9520
---
changelog: FP [`len_without_is_empty`]: No longer lints, if `len` as a non-default signature
[#10255](https://github.com/rust-lang/rust-clippy/pull/10255)
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