internal: Report macro definition errors on the definition
We still report them on the call site as well for the time being, and the diagnostic doesn't know where the error in the definition comes from, but that can be done later on
Add doc-alias based completion
Closes#14406.
I adapted the parsing code from the CfgExpr parsing code, maybe there's a better abstraction for both, or attribute parsing in general. It also includes `doc(hidden)`-parsing, which means it could replace the other function.
There are a few tests for parsing.
`process_all_names` changed the most, I added some docs there to explain what happens.
Many call sites just pass an empy vec to `add_path_resolution`'s `doc_aliases`, since either it doesn't make sense to pass anything (e.g. visibility completion) or I don't know where to get them from. Shouldn't really matter, as it will just not show aliases if the vec is empty and we can extend alias completion in these cases later.
I added two tests in `special.rs` for struct name completion (which was the main thing I wanted). I also tried function and field names, but these don't work yet. I want to add those in a follow-up PR.
Normalize associated types in paths in expressions
Part of #14393
When we resolve paths in expressions (either path expressions or paths in struct expressions), there's a need of projection normalization, which `TyLoweringContext` cannot do on its own. We've been properly applying normalization for paths in struct expressions without type anchor, but not for others:
```rust
enum E {
S { v: i32 }
Empty,
}
impl Foo for Bar {
type Assoc = E;
fn foo() {
let _ = Self::Assoc::S { v: 42 }; // path in struct expr without type anchor; we already support this
let _ = <Self>::Assoc::S { v: 42 }; // path in struct expr with type anchor; resolves with this PR
let _ = Self::Assoc::Empty; // path expr; resolves with this PR
}
}
```
With this PR we correctly resolve the whole path, but we need some more tweaks in HIR and/or IDE layers to properly resolve a qualifier (prefix) of such paths and provide IDE features that are pointed out in #14393 to be currently broken.
