Use `&mut Diagnostic` instead of `&mut DiagnosticBuilder` unless needed
This seems to be the established convention (02ff9e0) when `DiagnosticBuilder` was first added. I am guilty of introducing some of these.
Check if enum from foreign crate has any non exhaustive variants when attempting a cast
Fixes#91161
As stated in the issue, this will require a crater run as it might break other people's stuff.
Set tainted errors bit before emitting coerce suggestions.
Fixes#100246.
#89576 basically got 99% of the way there but the match typechecking code (which calls `coerce_inner`) also needed a similar fix.
Add some high-level docs to `FnCtxt` and `ItemCtxt`
I haven't understood the difference between these before, but
``@compiler-errors`` helped me clear it up. Hopefully this will help other
people who've been confused!
r? `@compiler-errors`
Some "this expression has a field"-related fixes
Each commit does something different and is worth reviewing, but the final diff from `master..HEAD` contains the sum of the changes to the UI tests, since some commits added UI tests "regressions" which were later removed in other commits.
The only change I could see adding on top of this is suppressing `Clone::clone` from the "this expression has a field that has this method" suggestion, since it's so commonly implemented by types that it's not worthwhile suggesting in general.
consider unnormalized types for implied bounds
extracted, and slightly modified, from #98900
The idea here is that generally, rustc is split into things which can assume its inputs are well formed[^1], and things which have verify that themselves.
Generally most predicates should only deal with well formed inputs, e.g. a `&'a &'b (): Trait` predicate should be able to assume that `'b: 'a` holds. Normalization can loosen wf requirements (see #91068) and must therefore not be used in places which still have to check well formedness. The only such place should hopefully be `WellFormed` predicates
fixes#87748 and #98543
r? `@jackh726` cc `@rust-lang/types`
[^1]: These places may still encounter non-wf inputs and have to deal with them without causing an ICE as we may check for well formedness out of order.
Implement `#[rustc_default_body_unstable]`
This PR implements a new stability attribute — `#[rustc_default_body_unstable]`.
`#[rustc_default_body_unstable]` controls the stability of default bodies in traits.
For example:
```rust
pub trait Trait {
#[rustc_default_body_unstable(feature = "feat", isssue = "none")]
fn item() {}
}
```
In order to implement `Trait` user needs to either
- implement `item` (even though it has a default implementation)
- enable `#![feature(feat)]`
This is useful in conjunction with [`#[rustc_must_implement_one_of]`](https://github.com/rust-lang/rust/pull/92164), we may want to relax requirements for a trait, for example allowing implementing either of `PartialEq::{eq, ne}`, but do so in a safe way — making implementation of only `PartialEq::ne` unstable.
r? `@Aaron1011`
cc `@nrc` (iirc you were interested in this wrt `read_buf`), `@danielhenrymantilla` (you were interested in the related `#[rustc_must_implement_one_of]`)
P.S. This is my first time working with stability attributes, so I'm not sure if I did everything right 😅
I haven't understood the difference between these before, but
`@compiler-errors` helped me clear it up. Hopefully this will help other
people who've been confused!
Multiple duplicate assignments of the same discriminant are now reported
in the samme error. We now point out the incrementation start point for
discriminants that are not explicitly assigned that are also duplicates.
Removed old test related to E0081 that is now covered by error-codes/E0081.rs.
Also refactored parts of the `check_enum` function.
Avoid pointing out `return` span if it has nothing to do with type error
This code:
```rust
fn f(_: String) {}
fn main() {
let x = || {
if true {
return ();
}
f("");
};
}
```
Emits this:
```
Compiling playground v0.0.1 (/playground)
error[E0308]: mismatched types
--> src/main.rs:8:11
|
8 | f("");
| ^^- help: try using a conversion method: `.to_string()`
| |
| expected struct `String`, found `&str`
|
note: return type inferred to be `String` here
--> src/main.rs:6:20
|
6 | return ();
| ^^
```
Specifically, that note has nothing to do with the type error in question. This is because the change implemented in #84244 tries to point out the `return` span on _any_ type coercion error within a closure that happens after a `return` statement, regardless of if the error has anything to do with it.
This is really easy to trigger -- just needs a closure (or an `async`) and an early return (or any other form, e.g. `?` operator suffices) -- and super distracting in production codebases. I'm letting #84128 regress because that issue is much harder to fix correctly, and I can re-open that issue after this lands.
As a drive-by, I added a `resolve_vars_if_possible` to the coercion error logic, which leads to some error improvements. Unrelated to the issue above, though.
Detect type mismatch due to loop that might never iterate
When loop as tail expression causes a miss match type E0308 error, recursively get the return statement and add diagnostic information on it.
when loop as tail expression for miss match type E0308 error, recursively get
the return statement and add diagnostic information on it
use rustc_hir::intravisit to collect the return expression
modified: compiler/rustc_typeck/src/check/coercion.rs
new file: src/test/ui/typeck/issue-98982.rs
new file: src/test/ui/typeck/issue-98982.stderr
Improve diagnostics for `const a: = expr;`
Adds a suggestion to write a type when there is a colon, but the type is not present.
I've also shrunk spans a little, so the suggestions are a little nicer.
Resolves#100146
r? `@compiler-errors`
Use `TraitEngine` in more places that don't specifically need `FulfillmentContext::new_in_snapshot`
Not sure if this change is worthwhile, but couldn't hurt re: chalkification
r? types
remove `commit_unconditionally`
`commit_unconditionally` is a noop unless we somehow inspect the current state of our snapshot. The only thing which does that is the leak check which was only used in one place where `commit_if_ok` is probably at least as, or even more, correct.
r? rust-lang/types
