Extend `CodegenBackend` trait with a function returning the translation
resources from the codegen backend, which can be added to the complete
list of resources provided to the emitter.
Signed-off-by: David Wood <david.wood@huawei.com>
Instead of loading the Fluent resources for every crate in
`rustc_error_messages`, each crate generates typed identifiers for its
own diagnostics and creates a static which are pulled together in the
`rustc_driver` crate and provided to the diagnostic emitter.
Signed-off-by: David Wood <david.wood@huawei.com>
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)
<!-- changelog_checked -->
Add configuration to lint missing docs of `pub(crate)` items
Fixes this: https://github.com/rust-lang/rust-clippy/issues/5736#issuecomment-1412442404
TODO:
- [x] Needs docs
- [x] Needs better names
- [x] Should `pub` items be checked to when this new option is enabled? I'm saying no because `missing_docs` already exists
`@flip1995` I'd like to get some input from you :)
---
changelog: Enhancement: [`missing_docs_in_private_items`]: Added new configuration `missing-docs-in-crate-items` to lint on items visible within the current crate. For example, `pub(crate)` items.
[#10303](https://github.com/rust-lang/rust-clippy/pull/10303)
<!-- changelog_checked -->
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)
<!-- changelog_checked -->
There are several `mk_foo`/`intern_foo` pairs, where the former takes an
iterator and the latter takes a slice. (This naming convention is bad,
but that's a fix for another PR.)
This commit changes several `mk_foo` occurrences into `intern_foo`,
avoiding the need for some `.iter()`/`.into_iter()` calls. Affected
cases:
- mk_type_list
- mk_tup
- mk_substs
- mk_const_list
Switch to `EarlyBinder` for `type_of` query
Part of the work to finish #105779 and implement https://github.com/rust-lang/types-team/issues/78.
Several queries `X` have a `bound_X` variant that wraps the output in `EarlyBinder`. This adds `EarlyBinder` to the return type of the `type_of` query and removes `bound_type_of`.
r? `@lcnr`
Implement partial support for non-lifetime binders
This implements support for non-lifetime binders. It's pretty useless currently, but I wanted to put this up so the implementation can be discussed.
Specifically, this piggybacks off of the late-bound lifetime collection code in `rustc_hir_typeck::collect::lifetimes`. This seems like a necessary step given the fact we don't resolve late-bound regions until this point, and binders are sometimes merged.
Q: I'm not sure if I should go along this route, or try to modify the earlier nameres code to compute the right bound var indices for type and const binders eagerly... If so, I'll need to rename all these queries to something more appropriate (I've done this for `resolve_lifetime::Region` -> `resolve_lifetime::ResolvedArg`)
cc rust-lang/types-team#81
r? `@ghost`
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)
<!-- changelog_checked -->
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)
<!-- changelog_checked -->
Use `target` instead of `machine` for mir interpreter integer handling.
The naming of `machine` only makes sense from a mir interpreter internals perspective, but outside users talk about the `target` platform. As per https://github.com/rust-lang/rust/pull/108029#issuecomment-1429791015
r? `@RalfJung`
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.
Avoid accessing HIR when it can be avoided
Experiment to see if it helps some incremental cases.
Will be rebased once https://github.com/rust-lang/rust/pull/107942 gets merged.
r? `@ghost`
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
<!-- changelog_checked -->
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)
<!-- changelog_checked -->
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.
Introduce `-Zterminal-urls` to use OSC8 for error codes
Terminals supporting the OSC8 Hyperlink Extension can support inline anchors where the text is user defineable but clicking on it opens a browser to a specified URLs, just like `<a href="URL">` does in HTML.
https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
Terminals supporting the OSC8 Hyperlink Extension can support inline
anchors where the text is user defineable but clicking on it opens a
browser to a specified URLs, just like `<a href="URL">` does in HTML.
https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
Make `[clippy::dump]` support trait items
Roses are red,
violets are blue,
trait items are rare,
`[clippy::dump]` is too
---
Let's just ignore the horrible poem... anyways. While working on Marker I noticed, that `[clippy::dump]` doesn't work on trait item (See [Playground](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=e2d9791ffa2872e7c09a9dfbd470350c)). This simply adds support for that. `[clippy::dump]` doesn't have UI tests, to make it more resistant to changes in the AST. I tested it locally and the dump works after these changes.
---
changelog: none
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)
<!-- changelog_checked -->
Fix version declared for semicolon_inside_block and semicolon_outside…
As per Issue #10244, the lint were documentated
as being part of 1.66.0 but will actually be
released 1.68.0 .
changelog: [`semicolon_inside_block`]: Documentation fix
Fixes#10244
Mark uninlined_format_args as pedantic
Fixes https://github.com/rust-lang/rust-clippy/issues/10087
We should restore this when rust-analyzer support gets better. Worth filing an issue to track.
changelog: Mark [`uninlined_format_args`] as `pedantic`
[`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)
<!-- changelog_checked -->
more than just `&self` in non-standard implementations.
changelog: Fix [`len_without_is_empty`] false positive when len has a
non-standard method signature
Fixes#9520
`invalid_regex`: Show full error when string value doesn't match source
changelog: [`invalid_regex`]: Show full error when parsing non-literals or regular strings containing escape sequences
Fixes#4170, the escape sequence there causes the span to be incorrect which will have caused most of the confusion
Remove HirId -> LocalDefId map from HIR.
Having this map in HIR prevents the creating of new definitions after HIR has been built.
Thankfully, we do not need it.
Based on https://github.com/rust-lang/rust/pull/103902
Remove `ControlFlow::{BREAK, CONTINUE}`
Libs-API decided to remove these in #102697.
Follow-up to #107023, which removed them from `compiler/`, but a couple new ones showed up since that was merged.
r? libs
Remove overlapping parts of multipart suggestions
This PR adds a debug assertion that the parts of a single substitution cannot overlap, fixes a overlapping substitution from the testsuite, and fixes https://github.com/rust-lang/rust/issues/106870.
Note that a single suggestion can still have multiple overlapping substitutions / possible edits, we just don't suggest overlapping replacements in a single edit anymore.
I've also included a fix for an unrelated bug where rustfix for `explicit_outlives_requirements` would produce multiple trailing commas for a where clause.
Compute generator saved locals on MIR
Generators are currently type-checked by introducing a `witness` type variable, which is unified with a `GeneratorWitness(captured types)` whose purpose is to ensure that the auto traits correctly migrate from the captured types to the `witness` type. This requires computing the captured types on HIR during type-checking, only to re-do it on MIR later.
This PR proposes to drop the HIR-based computation, and only keep the MIR one. This is done in 3 steps.
1. During type-checking, the `witness` type variable is never unified. This allows to stall all the obligations that depend on it until the end of type-checking. Then, the stalled obligations are marked as successful, and saved into the typeck results for later verification.
2. At type-checking writeback, `witness` is replaced by `GeneratorWitnessMIR(def_id, substs)`. From this point on, all trait selection involving `GeneratorWitnessMIR` will fetch the MIR-computed locals, similar to what opaque types do. There is no lifetime to be preserved here: we consider all the lifetimes appearing in this witness type to be higher-ranked.
3. After borrowck, the stashed obligations are verified against the actually computed types, in the `check_generator_obligations` query. If any obligation was wrongly marked as fulfilled in step 1, it should be reported here.
There are still many issues:
- ~I am not too happy having to filter out some locals from the checked bounds, I think this is MIR building that introduces raw pointers polluting the analysis;~ solved by a check specific to static variables.
- the diagnostics for captured types don't show where they are used/dropped;
- I do not attempt to support chalk.
cc `@eholk` `@jyn514` for the drop-tracking work
r? `@oli-obk` as you warned me of potential unsoundness
Move format_args!() into AST (and expand it during AST lowering)
Implements https://github.com/rust-lang/compiler-team/issues/541
This moves FormatArgs from rustc_builtin_macros to rustc_ast_lowering. For now, the end result is the same. But this allows for future changes to do smarter things with format_args!(). It also allows Clippy to directly access the ast::FormatArgs, making things a lot easier.
This change turns the format args types into lang items. The builtin macro used to refer to them by their path. After this change, the path is no longer relevant, making it easier to make changes in `core`.
This updates clippy to use the new language items, but this doesn't yet make clippy use the ast::FormatArgs structure that's now available. That should be done after this is merged.
use LocalDefId instead of HirId in trait resolution to simplify
the obligation clause resolution
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Use UnordMap and UnordSet for id collections (DefIdMap, LocalDefIdMap, etc)
This PR changes the `rustc_data_structures::define_id_collections!` macro to use `UnordMap` and `UnordSet` instead of `FxHashMap` and `FxHashSet`. This should account for a large portion of hash-maps being used in places where they can cause trouble.
The changes required are moderate but non-zero:
- In some places the collections are extracted into sorted vecs.
- There are a few instances where for-loops have been changed to extends.
~~Let's see what the performance impact is. With a bit more refactoring, we might be able to get rid of some of the additional sorting -- but the change set is already big enough. Unless there's a performance impact, I'd like to do further changes in subsequent PRs.~~
Performance does not seem to be negatively affected ([perf-run here](https://github.com/rust-lang/rust/pull/106977#issuecomment-1396776699)).
Part of [MCP 533](https://github.com/rust-lang/compiler-team/issues/533).
r? `@ghost`
Add `multiple_unsafe_ops_per_block` lint
Adds a lint, which restricts an `unsafe` block to only one unsafe operation.
Closes#10064
---
changelog: New lint: [`multiple_unsafe_ops_per_block`]
[#10206](https://github.com/rust-lang/rust-clippy/pull/10206)
<!-- changelog_checked -->
Fix suggestion in `transmutes_expressible_as_ptr_casts` when the source type is a borrow.
fixes#9894
changelog: `transmutes_expressible_as_ptr_casts`: Fix suggestion when the source type is a borrow.
[needless_return]: Remove all semicolons on suggestion
Closes#10182
Multiple semicolons currently breaks autofix for `needless_return` suggestions. Any semicolons left after removing return means that the return type will always be `()`, and thus fail to compile.
This PR allows `needless_return` to remove multiple semicolons.
The change won't cover the case where there is multiple line yet.
i.e.
```rust
fn needless_return() -> bool {
return true;
;;
}
```
---
changelog: Sugg: [`needless_return`]: Now removes all semicolons on the same line
[#10187](https://github.com/rust-lang/rust-clippy/pull/10187)
<!-- changelog_checked -->
`cast_possible_truncation` Suggest TryFrom when truncation possible
This fixes the last issues from https://github.com/rust-lang/rust-clippy/pull/9664 as the author seems to be inactive. The PR author was sadly kept during the rebase, due to the conflict resolution.
IDK if it's worth it do to a full review, I only added the last commit, everything else remained the same, besides a rebase.
---
changelog: Sugg: [`cast_possible_truncation`]: Now suggests using `try_from` or allowing the lint
[#10038](https://github.com/rust-lang/rust-clippy/pull/10038)
<!-- changelog_checked -->
closes: https://github.com/rust-lang/rust-clippy/issues/9231
Allow implementing `Hash` with derived `PartialEq` (`derive_hash_xor_eq`
This is a common pattern and is totally allowed by the `Hash` trait.
Fixes#2627
changelog: Move: Renamed `derive_hash_xor_eq` to [`derived_hash_with_manual_eq`]
[#10184](https://github.com/rust-lang/rust-clippy/pull/10184)
changelog: Enhancement: [`derived_hash_with_manual_eq`]: Now allows `#[derive(PartialEq)]` with custom `Hash` implementations
[#10184](https://github.com/rust-lang/rust-clippy/pull/10184)
<!-- changelog_checked -->
trim paths in `suspicious_to_owned`
This continues my path trimming spree. I'm not going to add yet another changelog entry, we should have one "trim paths in some applicable lints" entry instead.
---
changelog: none
unused_self: Don't trigger if the method body contains todo!()
If the author is using todo!(), presumably they intend to use self at some point later, so we don't have a good basis to recommend factoring out to an associated function.
Fixes#10117.
---
changelog: Enhancement: [`unused_self`]: No longer lints, if the method body contains a `todo!()` call
[#10166](https://github.com/rust-lang/rust-clippy/pull/10166)
<!-- changelog_checked -->
[#10167] Clarify that the lint only works if x eq. y in a `for` loop.
Reading the documentation for the lint, one could expect that the lint works in all cases that `X == Y`. This is false.
While the lint was updated, the documentation wasn't.
More information about the `N..N` problem in #5689 and #5628
---
Fixes#10167
changelog: [`reversed_empty_ranges`]: Update and clarify documentation
Reading the documentation for the lint, one could expect that the lint works in all cases that `X == Y`. This is false.
While the lint was updated, the documentation wasn't.
More information about the `N..N` problem in #5689 and #5628
trim paths in `box_default`
This might help with #10089, though I have not tested that yet. In any event, it keeps the suggestion short and to the point.
---
changelog: Trim paths in [`box_default`] suggestion
trim paths in `default_trait_access`/`clone_on_copy` suggestions
This should help making the suggestions more palatable. Similar to #10153.
---
changelog: trim paths in [`default_trait_access`]/[`clone_on_copy`] suggestions
If the author is using todo!(), presumably they intend to use self at
some point later, so we don't have a good basis to recommend factoring
out to an associated function.
Fixes#10117.
changelog: Don't trigger [`unused_self`] if the method body contains a `todo!()` call
[`drop_ref`]: don't lint idiomatic in match arm
fixes#10122
As established in issue #9482, it is idiomatic to use a single `drop()` expression in a match arm to achieve a side-effect of a function while discarding its output. This should also apply to cases where the function returns a reference.
The change to the lint's code was less than 1 line, because all the heavy lifting was done in PR #9491.
---
changelog: FP: [`drop_ref`]: No longer lints idiomatic expression in `match` arms
[#10142](https://github.com/rust-lang/rust-clippy/pull/10142)
<!-- changelog_checked -->
Make the iter_kv_map lint handle ref/mut annotations.
For the degenerate (`map(|(k, _)| k)`/`map(|(_, v)| v)`) cases a mut annotation is superfluous and a ref annotation won't compile, so no additional handling is required. For cases where the `map` call must be preserved ref/mut annotations should also be presereved so that the map body continues to work as expected.
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`iter_kv_map`]: handle ref/mut annotations
For the degenerate (`map(|(k, _)| k)`/`map(|(_, v)| v)`) cases a mut annotation is superfluous and a ref annotation won't compile, so no additional handling is required. For cases where the `map` call must be preserved ref/mut annotations should also be presereved so that the map body continues to work as expected.
don't lint field_reassign when field in closure
fixes#10136
This change makes the ContainsName struct visit all interior expressions, which means that ContainsName will return true even if `name` is used in a closure within `expr`.
---
changelog: FP: [`field_reassign_with_default`]: No longer lints cases, where values are initializes from closures capturing struct values
[#10143](https://github.com/rust-lang/rust-clippy/pull/10143)
<!-- changelog_checked -->
chore: fix identation of `if_chain` in `filter_map`
This is a really small fix.
If someone could take a look at it, I would appreciate it🙏
---
changelog: none
<!-- changelog_checked -->
This commit makes the ContainsName struct visit all interior
expressions, which means that ContainsName will return true
even if `name` is used in a closure within `expr`.
Move `mutex_atomic` to `restriction`
By #4295, the general consensus seems to be that `mutex_atomic` is not a useful lint in most cases. If anything, it could be useful as a restriction on code that for whatever reason can't use atomics. Keeping it in `clippy::nursery` is harmful to people attempting to use clippy for soundness.
---
changelog: Moved [`mutex_atomic`] to `restriction`
[#10115](https://github.com/rust-lang/rust-clippy/pull/10115)
<!-- chnagelog_checked -->
Rollup of 9 pull requests
Successful merges:
- #104531 (Provide a better error and a suggestion for `Fn` traits with lifetime params)
- #105899 (`./x doc library --open` opens `std`)
- #106190 (Account for multiple multiline spans with empty padding)
- #106202 (Trim more paths in obligation types)
- #106234 (rustdoc: simplify settings, help, and copy button CSS by not reusing)
- #106236 (docs/test: add docs and a UI test for `E0514` and `E0519`)
- #106259 (Update Clippy)
- #106260 (Fix index out of bounds issues in rustdoc)
- #106263 (Formatter should not try to format non-Rust files)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
fix incorrect suggestion in `suboptimal_flops`
fixes#10003
There was an error when trying to negate an expression like `x - 1.0`. We used to format it as `-x - 1.0` whereas a proper negation would be `-(x - 1.0)`.
Therefore, we add parentheses around the expression when it is `ExprKind::Binary`.
We also add parentheses around multiply and divide expressions, even though this is not strictly necessary.
changelog: [`suboptimal_flops`]: fix incorrect suggestion caused by an incorrect negation of floating point expressions.
There was an error when trying to negate an expression
like `x - 1.0`. We used to format it as `-x - 1.0` whereas
a proper negation would be `-(x - 1.0)`.
Therefore, we add parentheses around the expression when it is a
Binary ExprKind.
We also add parentheses around multiply and divide expressions,
even though this is not strictly necessary.
This patch not only improves visibility, but also fixes a potential bug.
When a lint description ends with code block, the string will have three
backquotes at the end.
Since the current implementation prints the default value immediately
after that, the markdown renderer is unable to properly close the code
block.
Add size_of_ref lint
This addresses #9995, which is likely raising a valid point about `std::mem::size_of_val()`: It's [very easy to use double-references as the argument](https://github.com/apache/arrow-datafusion/pull/4371#discussion_r1032385224), which the function will happily accept and give back the size of _the reference_, not the size of the value _behind_ the reference. In the worst case, if the value matches the programmer's expectation, this seems to work, while in fact, everything will go horribly wrong e.g. on a different platform.
The size of a `&T` is independent of what `T` is, and people might want to use `std::mem::size_of_val()` to actually get the size of _any_ reference (e.g. via `&&()`). I would rather suggest that this is always bad behavior, though ([instead](https://doc.rust-lang.org/reference/type-layout.html#pointers-and-references-layout), [and](https://doc.rust-lang.org/stable/std/primitive.usize.html#associatedconstant.BITS)). I, therefore, put this lint into `correctness`.
Since the problem is usually easily fixed by removing extra `&`, I went light on suggesting code.
---
changelog: New lint: [`size_of_ref`]
[#10098](https://github.com/rust-lang/rust-clippy/pull/10098)
<!-- changelog_checked -->
Improve `possible_borrower`
This PR makes several improvements to `clippy_uitls::mir::possible_borrower`. These changes benefit both `needless_borrow` and `redundant clone`.
1. **Use the compiler's `MaybeStorageLive` analysis**
I could spot not functional differences between the one in the compiler and the one in Clippy's repository. So, I removed the latter in favor of the the former.
2. **Make `PossibleBorrower` a dataflow analysis instead of a visitor**
The main benefit of this change is that allows `possible_borrower` to take advantage of statements' relative locations, which is easier to do in an analysis than in a visitor.
This is easier to illustrate with an example, so consider this one:
```rust
fn foo(cx: &LateContext<'_>, lint: &'static Lint) {
cx.struct_span_lint(lint, rustc_span::Span::default(), "", |diag| diag.note(&String::new()));
// ^
}
```
We would like to flag the `&` pointed to by the `^` for removal. `foo`'s MIR begins like this:
```rust
fn span_lint::foo::{closure#0}(_1: [closure@$DIR/needless_borrow.rs:396:68: 396:74], _2: &mut rustc_errors::diagnostic_builder::DiagnosticBuilder<'_, ()>) -> &mut rustc_errors::diagnostic_builder::DiagnosticBuilder<'_, ()> {
debug diag => _2; // in scope 0 at $DIR/needless_borrow.rs:396:69: 396:73
let mut _0: &mut rustc_errors::diagnostic_builder::DiagnosticBuilder<'_, ()>; // return place in scope 0 at $DIR/needless_borrow.rs:396:75: 396:75
let mut _3: &mut rustc_errors::diagnostic_builder::DiagnosticBuilder<'_, ()>; // in scope 0 at $DIR/needless_borrow.rs:396:75: 396:100
let mut _4: &mut rustc_errors::diagnostic_builder::DiagnosticBuilder<'_, ()>; // in scope 0 at $DIR/needless_borrow.rs:396:75: 396:100
let mut _5: &std::string::String; // in scope 0 at $DIR/needless_borrow.rs:396:85: 396:99
let _6: std::string::String; // in scope 0 at $DIR/needless_borrow.rs:396:86: 396:99
bb0: {
StorageLive(_3); // scope 0 at $DIR/needless_borrow.rs:396:75: 396:100
StorageLive(_4); // scope 0 at $DIR/needless_borrow.rs:396:75: 396:100
_4 = &mut (*_2); // scope 0 at $DIR/needless_borrow.rs:396:75: 396:100
StorageLive(_5); // scope 0 at $DIR/needless_borrow.rs:396:85: 396:99
StorageLive(_6); // scope 0 at $DIR/needless_borrow.rs:396:86: 396:99
_6 = std::string::String::new() -> bb1; // scope 0 at $DIR/needless_borrow.rs:396:86: 396:99
// mir::Constant
// + span: $DIR/needless_borrow.rs:396:86: 396:97
// + literal: Const { ty: fn() -> std::string::String {std::string::String::new}, val: Value(<ZST>) }
}
bb1: {
_5 = &_6; // scope 0 at $DIR/needless_borrow.rs:396:85: 396:99
_3 = rustc_errors::diagnostic_builder::DiagnosticBuilder::<'_, ()>::note::<&std::string::String>(move _4, move _5) -> [return: bb2, unwind: bb4]; // scope 0 at $DIR/needless_borrow.rs:396:75: 396:100
// mir::Constant
// + span: $DIR/needless_borrow.rs:396:80: 396:84
// + literal: Const { ty: for<'a> fn(&'a mut rustc_errors::diagnostic_builder::DiagnosticBuilder<'_, ()>, &std::string::String) -> &'a mut rustc_errors::diagnostic_builder::DiagnosticBuilder<'_, ()> {rustc_errors::diagnostic_builder::DiagnosticBuilder::<'_, ()>::note::<&std::string::String>}, val: Value(<ZST>) }
}
```
The call to `diag.note` appears in `bb1` on the line beginning with `_3 =`. The `String` is owned by `_6`. So, in the call to `diag.note`, we would like to know whether there are any references to `_6` besides `_5`.
The old, visitor approach did not consider the relative locations of statements. So all borrows were treated the same, *even if they occurred after the location of interest*.
For example, before the `_3 = ...` call, the possible borrowers of `_6` would be just `_5`. But after the call, the possible borrowers would include `_2`, `_3`, and `_4`.
So, in a sense, the call from which we are try to remove the needless borrow is trying to prevent us from removing the needless borrow(!).
With an analysis, things do not get so muddled. We can determine the set of possible borrowers at any specific location, e.g., using a `ResultsCursor`.
3. **Change `only_borrowers` to `at_most_borrowers`**
`possible_borrowers` exposed a function `only_borrowers` that determined whether the borrowers of some local were *exactly* some set `S`. But, from what I can tell, this was overkill. For the lints that currently use `possible_borrower` (`needless_borrow` and `redundant_clone`), all we really want to know is whether there are borrowers *other than* those in `S`. (Put another way, we only care about the subset relation in one direction.) The new function `at_most_borrowers` takes this more tailored approach.
4. **Compute relations "on the fly" rather than using `transitive_relation`**
The visitor would compute and store the transitive closure of the possible borrower relation for an entire MIR body.
But with an analysis, there is effectively a different possible borrower relation at each location in the body. Computing and storing a transitive closure at each location would not be practical.
So the new approach is to compute the transitive closure on the fly, as needed. But the new approach might actually be more efficient, as I now explain.
In all current uses of `at_most_borrowers` (previously `only_borrowers`), the size of the set of borrowers `S` is at most 2. So you need only check at most three borrowers to determine whether the subset relation holds. That is, once you have found a third borrower, you can stop, since you know the relation cannot hold.
Note that `transitive_relation` is still used by `clippy_uitls::mir::possible_origin` (a kind of "subroutine" of `possible_borrower`).
cc: `@Jarcho`
---
changelog: [`needless_borrow`], [`redundant_clone`]: Now track references better and detect more cases
[#9701](https://github.com/rust-lang/rust-clippy/pull/9701)
<!-- changelog_checked -->
Avoid `match_wildcard_for_single_variants` on guarded wild matches
fix#9993
changelog: FP: [`match_wildcard_for_single_variants`]: No longer lints on wildcards with a guard
[#10056](https://github.com/rust-lang/rust-clippy/pull/10056)
<!-- changelog_checked -->
r? `@Jarcho`
Null fn lints
Adds lints to check for code, that assumes nullable `fn()`.
### Lint examples:
`transmute_null_to_fn`:
```rust
error: transmuting a known null pointer into a function pointer
--> $DIR/transmute_null_to_fn.rs:9:23
|
LL | let _: fn() = std::mem::transmute(std::ptr::null::<()>());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this transmute results in undefined behavior
|
= help: try wrapping your function pointer type in `Option<T>` instead, and using `None` as a null pointer value
```
`fn_null_check`:
```rust
error: function pointer assumed to be nullable, even though it isn't
--> $DIR/fn_null_check.rs:13:8
|
LL | if (fn_ptr as *mut ()).is_null() {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: try wrapping your function pointer type in `Option<T>` instead, and using `is_none` to check for null pointer value
```
Closes#1644
---
changelog: Improvement: [`transmuting_null`]: Now detects `const` pointers to all types
[#10099](https://github.com/rust-lang/rust-clippy/pull/10099)
changelog: New lint: [`transmute_null_to_fn`]
[#10099](https://github.com/rust-lang/rust-clippy/pull/10099)
changelog: New lint: [`fn_null_check`]
[#10099](https://github.com/rust-lang/rust-clippy/pull/10099)
<!-- changelog_checked (This is just a flag for me, please don't add it manually) -->
Identify more cases of useless `into_iter()` calls
changelog: Sugg: [`useless_conversion`]: Now suggests removing calls to `into_iter()` on an expression implementing `Iterator`
[#10020](https://github.com/rust-lang/rust-clippy/pull/10020)
<!-- changelog_checked -->
If the type of the result of a call to `IntoIterator::into_iter()`
and the type of the receiver are the same, then the receiver
implements `Iterator` and `into_iter()` is the identity function.
The call to `into_iter()` may be removed in all but two cases:
- If the receiver implements `Copy`, `into_iter()` will produce
a copy of the receiver and cannot be removed. For example,
`x.into_iter().next()` will not advance `x` while `x.next()` will.
- If the receiver is an immutable local variable and the call to
`into_iter()` appears in a larger expression, removing the call to
`into_iter()` might cause mutability issues. For example, if `x`
is an immutable local variable, `x.into_iter().next()` will
compile while `x.next()` will not as `next()` receives
`&mut self`.
Rustup
r? `@ghost`
I'm on the train and my internet is too bad to download the necessary toolchain, so I have to use CI to find sync fallout.
changelog: none
<!-- changelog_checked -->
fix: not suggest seek_to_start_instead_of_rewind when expr is used
changelog: [`seek_to_start_instead_of_rewind`]: No longer lints, if the return of `seek` is used.
[#10096](https://github.com/rust-lang/rust-clippy/pull/10096)
<!-- changelog_checked -->
Fixes#10065
There used to be a logical bug where IncrementVisitor would
completely stop checking an expression/block after seeing a continue
statement. This led to issue #10058 where a variable incremented
(or otherwise modified) after any continue statement would still be
considered incremented only once.
The solution is to continue scanning the expression after seeing a
`continue` statement, but increment self.depth so that the Visitor
thinks that the rest of the loop is within a conditional.
Changelog 1.66
It's really nice to see a changelog with so many suggestion fixes and improvements. Not much else to say. This should be merged with the coming release on 2022-12-15. For the reviewer, please review it and approve it if it looks good. The merge should wait until the release :)
---
changelog: none
<!-- changelog_checked -->
improve `manual_is_ascii_check ` check
Sorry, not familiar the api, i can only check the method name of expression `<expr-1>.contains(<expr-2>)` after read clippy book and hints from #9933 . i dont know how to check
1. if <expr-1> is a specific range
2. <expr-2> is a character
r? `@xFrednet` could you please provide some more hints? 😝️
---
changelog: Enhancement: [`manual_is_ascii_check`]: Now detects ranges with `.contains()` calls
[#10053](https://github.com/rust-lang/rust-clippy/pull/10053)
<!-- changelog_checked -->
