This removes variance information from some diagnostics. However,
that variance information is not actually relevant here. Casting
`*const dyn Cat<'a>` to `*const S<dyn Cat<'static>>` is an error
regardless of whether `S` requires its argument to be invariant.
Wide-pointer casts always require the trait object arguments to be
invariant.
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 => {}
|
```
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: ;
| ^^^^^^^^^^^^^^^^^
```
Improve suggestion for "missing function argument" on multiline call
`rustc` has a very neat suggestion when the argument count does not match, with a nice placeholder that shows where an argument may be missing. Unfortunately the suggestion is always single-line, even when the function call spans across multiple lines. With this PR, `rustc` tries to guess if the function call is multiline or not, and emits a multiline suggestion when required.
r? `@jdonszelmann`
`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````````
`tests/ui`: A New Order [21/N]
> [!NOTE]
>
> Intermediate commits are intended to help review, but will be squashed prior to merge.
Some `tests/ui/` housekeeping, to trim down number of tests directly under `tests/ui/`. Part of rust-lang/rust#133895.
r? `@tgross35`
`tests/ui`: A New Order [18/N]
> [!NOTE]
>
> Intermediate commits are intended to help review, but will be squashed prior to merge.
Some `tests/ui/` housekeeping, to trim down number of tests directly under `tests/ui/`. Part of rust-lang/rust#133895.
r? `@tgross35`
Start moving wf checking away from HIR
I'm trying to only access the HIR in the error path. My hope is that once we move significant portions of wfcheck off HIR that incremental will be able to cache wfcheck queries significantly better.
I think I am reaching a blocker because we normally need to provide good spans to `ObligationCause`, so that the trait solver can report good errors. In some cases I have been able to use bad spans and improve them depending on the `ObligationCauseCode` (by loading HIR in the case where we actually want to error). To scale that further we'll likely need to remove spans from the `ObligationCause` entirely (leaving it to some variants of `ObligationCauseCode` to have a span when they can't recompute the information later). Unsure this is the right approach, but we've already been using it. I will create an MCP about it, but that should not affect this PR, which is fairly limited in where it does those kind of tricks.
Especially b862d8828e is interesting here, because I think it improves spans in all cases
This centralizes the placeholder type error reporting in one location, but it also exposes the granularity at which we convert things from hir to ty more. E.g. previously infer types in where bounds were errored together with the function signature, but now they are independent.
Parser: Recover error from named params while parse_path
Fixes#140169
I added test to the first commit and the second added the code and changes to test.
r? `@petrochenkov`
```
error[E0610]: `{integer}` is a primitive type and therefore doesn't have fields
--> $DIR/attempted-access-non-fatal.rs:7:15
|
LL | let _ = 2.l;
| ^
|
help: if intended to be a floating point literal, consider adding a `0` after the period and a `f64` suffix
|
LL - let _ = 2.l;
LL + let _ = 2.0f64;
|
```
Use a more targeted span when suggesting casting an `fn` item to an `fn` pointer.
```
error[E0308]: cannot coerce functions which must be inlined to function pointers
--> $DIR/cast.rs:10:33
|
LL | let _: fn(isize) -> usize = callee;
| ------------------ ^^^^^^ cannot coerce functions which must be inlined to function pointers
| |
| expected due to this
|
= note: expected fn pointer `fn(_) -> _`
found fn item `fn(_) -> _ {callee}`
= note: fn items are distinct from fn pointers
help: consider casting to a fn pointer
|
LL | let _: fn(isize) -> usize = callee as fn(isize) -> usize;
| +++++++++++++++++++++
```
```
error[E0308]: mismatched types
--> $DIR/fn-pointer-mismatch.rs:42:30
|
LL | let d: &fn(u32) -> u32 = foo;
| --------------- ^^^ expected `&fn(u32) -> u32`, found fn item
| |
| expected due to this
|
= note: expected reference `&fn(_) -> _`
found fn item `fn(_) -> _ {foo}`
help: consider using a reference
|
LL | let d: &fn(u32) -> u32 = &foo;
| +
```
Previously we'd point at the whole expression for replacement, instead of marking what was being added.
We could also modify the suggestions for `&(name as fn())`, but for that we require storing more accurate spans than we have now.
Account for mutable borrow in argument suggestion
```
error: value assigned to `object` is never read
--> $DIR/mut-arg-of-borrowed-type-meant-to-be-arg-of-mut-borrow.rs:21:5
|
LL | object = &mut object2;
| ^^^^^^
|
help: you might have meant to mutate the pointed at value being passed in, instead of changing the reference in the local binding
|
LL ~ fn change_object3(object: &mut Object) {
LL |
LL | let object2 = Object;
LL ~ *object = object2;
|
```
instead of
```
error: value assigned to `object` is never read
--> $DIR/mut-arg-of-borrowed-type-meant-to-be-arg-of-mut-borrow.rs:21:5
|
LL | object = &mut object2;
| ^^^^^^
|
help: you might have meant to mutate the pointed at value being passed in, instead of changing the reference in the local binding
|
LL ~ fn change_object3(object: &mut mut Object) {
LL |
LL | let object2 = Object;
LL ~ *object = object2;
|
```
Fix#136028.
```
error: value assigned to `object` is never read
--> $DIR/mut-arg-of-borrowed-type-meant-to-be-arg-of-mut-borrow.rs:21:5
|
LL | object = &mut object2;
| ^^^^^^
|
help: you might have meant to mutate the pointed at value being passed in, instead of changing the reference in the local binding
|
LL ~ fn change_object3(object: &mut Object) {
LL |
LL | let object2 = Object;
LL ~ *object = object2;
|
```
instead of
```
error: value assigned to `object` is never read
--> $DIR/mut-arg-of-borrowed-type-meant-to-be-arg-of-mut-borrow.rs:21:5
|
LL | object = &mut object2;
| ^^^^^^
|
help: you might have meant to mutate the pointed at value being passed in, instead of changing the reference in the local binding
|
LL ~ fn change_object3(object: &mut mut Object) {
LL |
LL | let object2 = Object;
LL ~ *object = object2;
|
```
Fix#136028.
