rustc_typeck: improve diagnostics for -> _ fn return type
This should implement IIUC the mentioned issue.
~~I'm not sure if there is a better way than `get_infer_ret_ty` to get/check the return type without code duplication.~~
~~Also, is this unwrap be okay `ty::Binder::bind(*tables.liberated_fn_sigs().get(hir_id).unwrap())`?~~
r? @eddyb
Closes: https://github.com/rust-lang/rust/issues/56132
resolve: Improve candidate search for unresolved macro suggestions
Use same scope visiting machinery for both collecting suggestion candidates and actually resolving the names.
The PR is better read in per-commit fashion with whitespace changes ignored (the first commit in particular moves some code around).
This should be the last pre-requisite for https://github.com/rust-lang/rust/pull/62086.
r? @davidtwco
Check that trait is exported or public before adding hint
Closes#62194.
This PR checks the `AccessLevels` of a trait to check whether adding the intercrate ambiguity hint is valid or not.
I am unsure of both the use of `.unwrap()` as well as removing hints for [downstream *and* [upstream](92b0f52584/src/librustc/traits/select.rs (L112-L142)).
Normally `#![feature(...)]` shouldn't change behavior, but custom attributes in particular are in the process of retirement, and we should not produce a message telling to enable them.
It also helps with unifying diagnostics for unresolved macros.
Suggest assoc type on type not found in trait method definition
Given
```
trait A {
type Bla;
fn to_bla(&self) -> Bla;
}
```
suggest using `Self::Bla`:
```
error[E0412]: cannot find type `Bla` in this scope
--> file.rs:3:25
|
LL | fn to_bla(&self) -> Bla;
| ^^^ help: try: `Self::Bla`
```
Fix#62650.
Fix#62660
If the explicitly given type of a `self` parameter fails to parse correctly, we need to propagate the error rather than dropping it and causing an ICE.
Fixes#62660.
Make VaListImpl<'f> invariant over the 'f lifetime
After doing some research on variance and going back to look at `VaList` and `VaListImpl`, I realized that `VaList<'a, 'f>` is invariant over the `'f` lifetime (and covariant over `'a`), but `VaListImpl<'f>` isn't invariant but probably should be. This patch makes `VaListImpl<'f>` invariant over `'f`.
r? @eddyb
cc @dlrobertson
Remove never_type feature requirement for exhaustive patterns
I **think** this resolves#51221
At least for me, it doesn't ICE anymore and all tests are still passing, so LGTM
Do not emit type errors after parse error in last statement of block
When recovering from a parse error inside a block, do not emit type
errors generating on that block's recovered return expression.
Fix#57383.
If the explicitly given type of a `self` parameter fails to parse correctly,
we need to propagate the error rather than dropping it and causing an ICE.
Fixes#62660.
Make struct_tail normalize when possible
As noted in commit message: this replaces the existing methods to extract the struct tail(s) with new entry points that make the handling of normalization explicit.
Most of the places that call `struct_tail` are during codegen, post type-checking, and therefore they can get away with using `tcx.normalize_erasing_regions` (this is the entry point `struct_tail_erasing_lifetimes`)
For other cases that may arise, one can use the core method, which is parameterized over the normalization `Ty -> Ty` closure (`struct_tail_with_normalize`).
Or one can use the trivial entry point that does not normalization (`struct_tail_without_normalization`)
----
I spent a little while trying to make a test that exposed the bug via `impl Trait` rather than a projection, but I failed to find something that tripped up the current nightly `rustc`.
* I have *not* spent any time trying to make tests that trip up the other places where `struct_tail` was previously being called. While I do think the task of making such tests could be worthwhile, I am simply running out of time. (Its also possible that the layout code is always the first point called, and thus it may be pointless to try to come up with such tests.)
I also spent a little time discussing with @eddyb where this code should live. They suggested moving `struct_tail` and its sibling `struct_lockstep_tails` to the `LayoutCx`. But in the interest of time, I have left that refactoring (which may be questionable at this point) to a follow-up task.
----
Fix#60431
