Unused assignments to an unused variable should trigger only the
`unused_variables` lint and not also the `unused_assignments` lint.
This was previously implemented by checking whether the span of the
assignee was within the span of the binding pattern, however that failed
to capture situations was imported from elsewhere (eg from the input
tokenstream of a proc-macro that generates the binding pattern).
By comparing the span of the assignee to those of the variable
introductions instead, a reported stable-to-stable regression is
resolved.
This fix also impacted some other preexisting tests, which had
(undesirably) been triggering both the `unused_variables` and
`unused_assignments` lints on the same initializing assignment; those
tests have therefore now been updated to expect only the former lint.
(cherry picked from commit 22b3f59882)
Avoid ICEs after bad patterns, for the other syntactic variants
This PR introduces changes equivalent to the ones in rust-lang/rust#126320, but also for struct and tuple patterns, instead of tuple struct patterns only.
Fixesrust-lang/rust#150507.
Fix ICE by rejecting const blocks in patterns during AST lowering (closes#148138)
This PR fixes the ICE reported in rust-lang/rust#148138.
The root cause is that `const` blocks aren’t allowed in pattern position, but the AST lowering logic still attempted to create `PatExprKind::ConstBlock`, allowing invalid HIR to reach type checking and trigger a `span_bug!`.
Following the discussion in the issue, this patch removes the `ConstBlock` lowering path from `lower_expr_within_pat`. Any `ExprKind::ConstBlock` inside a pattern is now handled consistently with other invalid pattern expressions.
A new UI test is included to ensure the compiler reports a proper error and to prevent regressions.
Closesrust-lang/rust#148138.
This fixes the ICE reported by rejecting `const` blocks in
pattern position during AST lowering.
Previously, `ExprKind::ConstBlock` could reach HIR as `PatExprKind::ConstBlock`,
allowing invalid patterns to be type-checked and triggering an ICE.
This patch removes the lowering path for const blocks in patterns
and emits a proper diagnostic instead.
A new UI test is added to ensure the compiler reports a regular error
and to prevent regressions.
Suggest struct pattern when destructuring Range with .. syntax
implemented a new diagnostic in rustc_resolve to detect invalid range destructuring attempts (e.g., let start..end = range). The fix identifies when resolution fails for identifiers acting as range bounds specifically handling cases where bounds are parsed as expressions and suggests the correct struct pattern syntax (std::ops::Range { start, end }). This replaces confusing "cannot find value" errors with actionable help, verified by a new UI test covering various identifier names.
Fixesrust-lang/rust#149777
Tidying up tests/ui/issues 14 tests [5/N]
> [!NOTE]
> Intermediate commits are intended to help review, but will be squashed add comment commit prior to merge.
part of rust-lang/rust#133895
move `tests/ui/inherent-impls-overlap-check` to `tests/ui/duplicate/inherent-impls-overlap-check`.
r? Kivooeo
Tidying up tests/ui/issues 33 tests [4/N]
> [!NOTE]
> Intermediate commits are intended to help review, but will be squashed add comment commit prior to merge.
part of rust-lang/rust#133895
`tests/ui/compile-flags` split it into `tests/ui/compile-flags/invalid/` and `tests/ui/compile-flags/run-pass/`
r? Kivooeo
Relocate issues/issue-51154.rs to closures/box-generic-closure.rs
Relocate issues/issue-51515.rs to
borrowck/assignment-to-immutable-ref.rs
Relocate issues/issue-53348.rs to mismatched_types/deref-string-assign.rs
Relocate issues/issue-52717.rs to
pattern/match-enum-struct-variant-field-missing.rs
Relocate issues/issue-53300.rs to
type/cannot-find-wrapper-with-impl-trait.rs
Provide more context when mutably borrowing an imutably borrowed value
Point at statics and consts being mutable borrowed or written to:
```
error[E0594]: cannot assign to immutable static item `NUM`
--> $DIR/E0594.rs:4:5
|
LL | static NUM: i32 = 18;
| --------------- this `static` cannot be written to
...
LL | NUM = 20;
| ^^^^^^^^ cannot assign
```
Point at the expression that couldn't be mutably borrowed from a pattern:
```
error[E0596]: cannot borrow data in a `&` reference as mutable
--> $DIR/mut-pattern-of-immutable-borrow.rs:19:14
|
LL | match &arg.field {
| ---------- this cannot be borrowed as mutable
LL | Some(ref mut s) => s.push('a'),
| ^^^^^^^^^ cannot borrow as mutable
```
Partially address rust-lang/rust#74617.
Point at statics and consts being mutable borrowed or written to:
```
error[E0594]: cannot assign to immutable static item `NUM`
--> $DIR/E0594.rs:4:5
|
LL | static NUM: i32 = 18;
| --------------- this `static` cannot be written to
...
LL | NUM = 20;
| ^^^^^^^^ cannot assign
```
Point at the expression that couldn't be mutably borrowed from a pattern:
```
error[E0596]: cannot borrow data in a `&` reference as mutable
--> $DIR/mut-pattern-of-immutable-borrow.rs:19:14
|
LL | match &arg.field {
| ---------- this cannot be borrowed as mutable
LL | Some(ref mut s) => s.push('a'),
| ^^^^^^^^^ cannot borrow as mutable
```
```
error[E0277]: the trait bound `[[u16; 3]; 2]: Bar` is not satisfied
--> $DIR/issue-67185-2.rs:21:6
|
LL | impl Foo for FooImpl {}
| ^^^ the trait `Bar` is not implemented for `[[u16; 3]; 2]`
|
help: the following other types implement trait `Bar`
--> $DIR/issue-67185-2.rs:9:1
|
LL | impl Bar for [u16; 4] {}
| ^^^^^^^^^^^^^^^^^^^^^ `[u16; 4]`
LL | impl Bar for [[u16; 3]; 3] {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ `[[u16; 3]; 3]`
note: required by a bound in `Foo`
--> $DIR/issue-67185-2.rs:14:30
|
LL | trait Foo
| --- required by a bound in this trait
LL | where
LL | [<u8 as Baz>::Quaks; 2]: Bar,
| ^^^ required by this bound in `Foo`
```
clarify wording of match ergonomics diagnostics (`rust_2024_incompatible_pat` lint and error)
Partially addresses rust-lang/rust#143557:
- Uses different wording than the Edition Guide chapter, to hopefully stand alone a bit better. Instead of referring to the "default binding mode", it now talks about what can't be written "within elided reference patterns". I ended up going with "elided" instead of "implicit" in hope that it reads bit less like it should behave the same as an explicit reference pattern, but I'm not totally happy with that wording.
- The explanatory note still points to where the default binding mode was introduced, but only refers to its effect, not what we call it. How that relates to the rest of the diagnostic may still be a bit of a puzzle, but hopefully it isn't too much of one? It also doesn't make sense anymore for the case of `&` written under a by-ref binding mode, so I've left the note out in that case (but kept the label). It's more cramped, but talking about binding modes would feel like a non-sequitur for the error about `&` patterns without further explanation.
- Links to the stable version of the Edition Guide instead of the nightly version. It looks like almost every link to the Edition Guide in diagnostics is to the nightly version, presumably for the same reason as here: the diagnostics were added before the new Edition was stabilized, then never updated. I'll make a separate PR to clean up the others.
This only changes the diagnostic messages, not the code suggestion or the Edition Guide.
r? `@Nadrieril` or reassign
On unused binding or binding not present in all patterns, suggest potential typo of unit struct/variant or const
When encountering an or-pattern with a binding not available in all patterns, look for consts and unit struct/variants that have similar names as the binding to detect typos.
```
error[E0408]: variable `Ban` is not bound in all patterns
--> $DIR/binding-typo.rs:22:9
|
LL | (Foo, _) | (Ban, Foo) => {}
| ^^^^^^^^ --- variable not in all patterns
| |
| pattern doesn't bind `Ban`
|
help: you might have meant to use the similarly named unit variant `Bar`
|
LL - (Foo, _) | (Ban, Foo) => {}
LL + (Foo, _) | (Bar, Foo) => {}
|
```
For items that are not in the immedate scope, suggest the full path for them:
```
error[E0408]: variable `Non` is not bound in all patterns
--> $DIR/binding-typo-2.rs:51:16
|
LL | (Non | Some(_))=> {}
| --- ^^^^^^^ pattern doesn't bind `Non`
| |
| variable not in all patterns
|
help: you might have meant to use the similarly named unit variant `None`
|
LL - (Non | Some(_))=> {}
LL + (core::option::Option::None | Some(_))=> {}
|
```
When encountering a typo in a pattern that gets interpreted as an unused binding, look for unit struct/variant of the same type as the binding:
```
error: unused variable: `Non`
--> $DIR/binding-typo-2.rs:36:9
|
LL | Non => {}
| ^^^
|
help: if this is intentional, prefix it with an underscore
|
LL | _Non => {}
| +
help: you might have meant to pattern match on the similarly named variant `None`
|
LL - Non => {}
LL + std::prelude::v1::None => {}
|
```
Suggest constant on unused binding in a pattern
```
error: unused variable: `Batery`
--> $DIR/binding-typo-2.rs:110:9
|
LL | Batery => {}
| ^^^^^^
|
help: if this is intentional, prefix it with an underscore
|
LL | _Batery => {}
| +
help: you might have meant to pattern match on the similarly named constant `Battery`
|
LL | Battery => {}
| +
```
Fixrust-lang/rust#51976.
a more general version of https://github.com/rust-lang/rust/pull/146080.
after a bit of hacking in [`fluent.rs`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_fluent_macro/src/fluent.rs), i discovered that i'm not the only one that is bad at following guidelines 😅. this pr lowercases the first letter of all the error messages in the codebase.
(i did not change things that are traditionally uppercased such as _MIR_, _ABI_ or _C_)
i think it's reasonable to run a `@bors try` so all the test suite is checked, as i cannot run some of the tests on my machine. i double checked (and replaced manually) all the old error messages, but better be safe than sorry.
in the future i will try to add a check in `x test tidy` that errors if an error message starts with an uppercase letter.
Rehome 30 `tests/ui/issues/` tests to other subdirectories under `tests/ui/` [#2 of Batch #2]
Part of rust-lang/rust#133895
Methodology:
1. Refer to the previously written `tests/ui/SUMMARY.md`
2. Find an appropriate category for the test, using the original issue thread and the test contents.
3. Add the issue URL at the bottom (not at the top, as that would mess up stderr line numbers)
4. Rename the tests to make their purpose clearer
Inspired by the methodology that `@Kivooeo` was using.
r? `@jieyouxu`
```
error[E0408]: variable `Ban` is not bound in all patterns
--> f12.rs:9:9
|
9 | (Foo,Bar)|(Ban,Foo) => {}
| ^^^^^^^^^ --- variable not in all patterns
| |
| pattern doesn't bind `Ban`
|
help: you might have meant to use the similarly named previously used binding `Bar`
|
9 - (Foo,Bar)|(Ban,Foo) => {}
9 + (Foo,Bar)|(Bar,Foo) => {}
|
```
When encountering an unmet trait bound, point at local type that doesn't implement the trait:
```
error[E0277]: the trait bound `Bar<T>: Foo` is not satisfied
--> $DIR/issue-64855.rs:9:19
|
LL | pub struct Bar<T>(<Self as Foo>::Type) where Self: ;
| ^^^^^^^^^^^^^^^^^^^ unsatisfied trait bound
|
help: the trait `Foo` is not implemented for `Bar<T>`
--> $DIR/issue-64855.rs:9:1
|
LL | pub struct Bar<T>(<Self as Foo>::Type) where Self: ;
| ^^^^^^^^^^^^^^^^^
```
Rehome 32 `tests/ui/issues/` tests to other subdirectories under `tests/ui/`
rust-lang/rust#143902 divided into smaller, easier to review chunks.
Part of rust-lang/rust#133895
Methodology:
1. Refer to the previously written `tests/ui/SUMMARY.md`
2. Find an appropriate category for the test, using the original issue thread and the test contents.
3. Add the issue URL at the bottom (not at the top, as that would mess up stderr line numbers)
4. Rename the tests to make their purpose clearer
Inspired by the methodology that `@Kivooeo` was using.
r? `@jieyouxu`
`tests/ui/issues/`: The Issues Strike Back [4/N]
Some `tests/ui/issues/` housekeeping, to trim down number of tests directly under `tests/ui/issues/`. Part of https://github.com/rust-lang/rust/issues/133895.
r? ````````@jieyouxu````````
