Combine `ty::Projection` and `ty::Opaque` into `ty::Alias`
Implements https://github.com/rust-lang/types-team/issues/79.
This PR consolidates `ty::Projection` and `ty::Opaque` into a single `ty::Alias`, with an `AliasKind` and `AliasTy` type (renamed from `ty::ProjectionTy`, which is the inner data of `ty::Projection`) defined as so:
```
enum AliasKind {
Projection,
Opaque,
}
struct AliasTy<'tcx> {
def_id: DefId,
substs: SubstsRef<'tcx>,
}
```
Since we don't have access to `TyCtxt` in type flags computation, and because repeatedly calling `DefKind` on the def-id is expensive, these two types are distinguished with `ty::AliasKind`, conveniently glob-imported into `ty::{Projection, Opaque}`. For example:
```diff
match ty.kind() {
- ty::Opaque(..) =>
+ ty::Alias(ty::Opaque, ..) => {}
_ => {}
}
```
This PR also consolidates match arms that treated `ty::Opaque` and `ty::Projection` identically.
r? `@ghost`
Rollup of 7 pull requests
Successful merges:
- #105147 (Allow unsafe through inline const)
- #105438 (Move some codegen-y methods from `rustc_hir_analysis::collect` -> `rustc_codegen_ssa`)
- #105464 (Support #[track_caller] on async closures)
- #105476 (Change pattern borrowing suggestions to be verbose and remove invalid suggestion)
- #105500 (Make some diagnostics not depend on the source of what they reference being available)
- #105628 (Small doc fixes)
- #105659 (Don't require owned data in `MaybeStorageLive`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove previously existing fallback that tried to give a good turbofish
suggestion, `need_type_info` is already good enough.
Special case `::<Vec<_>` suggestion for `Iterator::collect`.
Point out the type of associated types in every method call of iterator chains
Partially address #105184 by pointing out the type of associated types in every method call of iterator chains:
```
note: the expression is of type `Map<std::slice::Iter<'_, {integer}>, [closure@src/test/ui/iterators/invalid-iterator-chain.rs:12:18: 12:21]>`
--> src/test/ui/iterators/invalid-iterator-chain.rs:12:14
|
10 | vec![0, 1]
| ---------- this expression has type `Vec<{integer}>`
11 | .iter()
| ------ associated type `std::iter::Iterator::Item` is `&{integer}` here
12 | .map(|x| { x; })
| ^^^^^^^^^^^^^^^ associated type `std::iter::Iterator::Item` is `()` here
```
We also reduce the number of impls we mention when any of the candidates is an "exact match". This benefits the output of cases with numerics greatly.
Outstanding work would be to provide a structured suggestion for appropriate changes, like in this case detecting the spurious `;` in the closure.
When encountering an unmet obligation that affects a method chain, like
in iterator chains where one of the links has the wrong associated
type, we point at every method call and mention their evaluated
associated type at that point to give context to the user of where
expectations diverged from the code as written.
```
note: the expression is of type `Map<std::slice::Iter<'_, {integer}>, [closure@$DIR/invalid-iterator-chain.rs:12:18: 12:21]>`
--> $DIR/invalid-iterator-chain.rs:12:14
|
LL | vec![0, 1]
| ---------- this expression has type `Vec<{integer}>`
LL | .iter()
| ------ associated type `std::iter::Iterator::Item` is `&{integer}` here
LL | .map(|x| { x; })
| ^^^^^^^^^^^^^^^ associated type `std::iter::Iterator::Item` is `()` here
```
Move some queries and methods
Each commit's title should be self-explanatory. Motivated to break up some large, general files and move queries into leaf crates.
normalize before handling simple checks for evaluatability of `ty::Const`
`{{{{{{{ N }}}}}}}` is desugared into a `ConstKind::Unevaluated` for an anonymous `const` item so when calling `is_const_evaluatable` on it we skip the `ConstKind::Param(_) => Ok(())` arm which is incorrect.
Make `note_obligation_cause_code` take a `impl ToPredicate` for predicate
The only usecase that wasn't `impl ToPredicate` was noting overflow errors while revealing opaque types, which passed in an `Obligation<'tcx, Ty<'tcx>>`... Since this only happens in a `RevealAll` environment, which is after typeck (and probably primarily within `normalize_erasing_regions`) we're unlikely to display anything useful while noting this code, evidenced by the lack of UI test changes.
support `ConstKind::Expr` in `is_const_evaluatable` and `WfPredicates::compute`
Fixes#105205
Currently we haven't implemented a way to evaluate `ConstKind::Expr(Expr::Binop(Add, 1, 2))` so I just left that with a `FIXME` and a `delay_span_bug` since I have no idea how to do that and it would make this a much larger (and more complicated) PR :P
Tweak "the following other types implement trait"
When *any* of the suggested impls is an exact match, *only* show the exact matches. This is particularly relevant for integer types.
r? `@compiler-errors`
