rustc_span: Optimize syntax context comparisons
Including comparisons with root context.
- `eq_ctxt` doesn't require retrieving full `SpanData`, or taking the span interner lock twice.
- Checking `SyntaxContext` for "rootness" is cheaper than extracting a full outer `ExpnData` for it and checking *it* for rootness.
The internal lint for `eq_ctxt` is also tweaked to detect `a.ctxt() != b.ctxt()` in addition to `a.ctxt() == b.ctxt()`.
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
Fix scoping for let chains in match guards
If let guards were previously represented as a different type of guard in HIR and THIR. This meant that let chains in match guards were not handled correctly because they were treated exactly like normal guards.
- Remove `hir::Guard` and `thir::Guard`.
- Make the scoping different between normal guards and if let guards also check for let chains.
closes#118593
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 {
| ++++
```
Polish `missing_enforced_import_renames` documentation
* Fixes a typo in the name of the lint (`enforce-import-renames` instead of `enforced-import-renames`).
* Copyedit “Why” paragraph.
* Make the example configuration use a multi-line list, since it is not particularly expected that a real project will have *exactly one* rename to enforce (and the old formatting had unbalanced whitespace).
changelog: none
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
fix: metadata-collector lists wrong affected lints
fixes#12042
This PR addresses the issue where the `metadata collector` incorrectly generates the `Affected Lints` section when a comma is included in the configuration documentation.
I made adjustments; however, if the `/// Lint: SOMETHING` section ends with `.` it always produces the correct output.
For example,
```rust
/// Lint: PUB_UNDERSCORE_FIELDS
```
should be
```rust
/// Lint: PUB_UNDERSCORE_FIELDS.
```
changelog: none
Include GitLab in the CI section of the clippy doc book
Fixes#12012
changelog: Docs: [`Continuous Integration`] now includes how to use clippy in GitLab CI.
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.
