remove unreachable error code `E0490`
AFAIK, the untested and undocumented error code `E0490` is now unreachable, it was from the days of the original borrow checker.
cc ``@GuillaumeGomez`` #61137
Handle inference variables in `CollectAllMismatches` correctly
1. Fix#106240
2. Treat int/float type variables correctly (see `src/test/ui/iterators/invalid-iterator-chain-with-int-infer.rs`), so we can point out things like "`Iterator::Item` changed to `{integer}` here"
Harden the pre-tyctxt query system against accidental recomputation
While the current compiler has no issues where we `take` and then compute the query again, in https://github.com/rust-lang/rust/pull/105462 I accidentally introduced such a case.
I also took the opportunity to remove `peek_mut`, which is only ever used for `global_tcx` to then invoke `enter`. I added an `enter` method directly on the query.
Remove `<dyn AstConv<'tcx>>::fun(c, ...)` calls in favour of `c.astconv().fun(...)`
This removes the need for <>><><><<>> dances and makes the code a bit nicer.
Not sure if `astconv` is the best name though, maybe someone has a better idea?
Move autoderef to `rustc_hir_analysis`
Not sure if this is a change we actually want, but autoderef really is only (functionally) used by `rustc_hir_analysis` and `rustc_hir_typeck`, so it probably should live there.
Instead, implement a separate autoderef helper in `TypeErrCtxt` for the one use-case that goes against the ordering of the crate graph..
Migrate mir_build diagnostics 2 of 3
The first three commits are fairly boring, however I've made some changes to the output of the match checking diagnostics.
Clean up `OnUnimplementedFormatString::verify`
Lift the always-allowed symbols to a static array and replace a `match iter().find(...)` with `iter().any(...)`
Allow codegen to unsize `dyn*` to `dyn`
`dyn* Trait` is just another type that implements `Trait`, so we should be able to unsize `&dyn* Trait` into `&dyn Trait` perfectly fine, same for `Box` and other unsizeable types.
Fixes#106488
Prefer non-`[type error]` candidates during selection
Fixes#102130Fixes#106351
r? types
note: Alternatively we could filter out error where-clauses during param-env construction? But we still need to filter out impls with errors during `match_impl`, I think.
Fix invalid syntax and incomplete suggestion in impl Trait parameter type suggestions for E0311
Fixes#105544
The problems: The suggestion given for E0311 has invalid syntax when the synthetic type parameter is used for Trait type in function declaration:
```rust
fn foo(d: impl Sized) -> impl Sized
```
instead of explicitly specified like the following:
```rust
fn foo<T: Sized>(d: T) -> impl Sized
```
In addition to the syntax error, the suggestions given for E0311 are not complete when multiple elided lifetimes are involved in lifetime bounds, not all involved parameters are given the named lifetime in the suggestions. For the following test case:
```
fn foo(d: impl Sized, p: &mut ()) -> impl Sized + '_ {
(d, p)
}
```
a good suggestion should add the lifetime 'a to both d and p, instead of d only:
```
fn foo<'a>(d: impl Sized + 'a, p: &'a mut ()) -> impl Sized + '_ {
(d, p)
}
```
The Solution: Fix the syntax problem in the suggestions when synthetic type parameter is used, and also add lifetimes for all involved parameters.
Recover from where clauses placed before tuple struct bodies
Open to any suggestions regarding the phrasing of the diagnostic.
Fixes#100790.
`@rustbot` label A-diagnostics
r? diagnostics
Note predicate span on `ImplDerivedObligation`
Seems obvious to point out the where-clause that introduces the `ImplDerivedObligation` :)
r? `@estebank`
