Don't install default projection bound for return-position `impl Trait` in trait methods with no body
This ensures that we never try to project to an opaque type in a trait method that has no body to infer its hidden type, which means we never later call `type_of` on that opaque. This is because opaque types try to reveal their hidden type when proving auto traits.
I thought about this a lot, and I think this is a fix that's less likely to introduce other strange downstream ICEs than #113461.
Fixes#113434
r? `@spastorino`
Fix invalid suggestion for mismatched types in closure arguments
This PR fixes the invalid suggestion for mismatched types in closure arguments.
The invalid suggestion came from a wrongly created span in the parser for closure arguments that don't have a type specified. Specifically, the span in this case was the last token span, but in the case of tuples, the span represented the last parenthesis instead of the whole tuple, which is fixed by taking the more accurate span of the pattern.
There is one unfortunate downside of this fix, it worsens even more the diagnostic for mismatched types in closure args without an explicit type. This happens because there is no correct span for implied inferred type. I tried also fixing this but it's a rabbit hole.
Fixes https://github.com/rust-lang/rust/issues/114180
The invalid suggestion came from a wrongly created span in `rustc_parse'
for closure arguments that didn't have a type specified. Specifically,
the span in this case was the last token span, but in the case of
tuples, the span represented the last parenthesis instead of the whole
tuple, which is fixed by taking the more accurate span of the pattern.
Skip reporting item name when checking RPITIT GAT's associated type bounds hold
Doesn't really make sense to label an item that has a name that users can't really mention. Fixes#114145. Also fixes#113794.
r? `@spastorino`
allow opaques to be defined by trait queries, again
This basically reverts #112963.
Moreover, all call-sites of `enter_canonical_trait_query` can now define opaque types, see the ui test `defined-by-user-annotation.rs`.
Fixes#113689
r? `@compiler-errors` `@oli-obk`
Replace RPITIT current impl with new strategy that lowers as a GAT
This PR replaces the current implementation of RPITITs with the new implementation that we had under -Zlower-impl-trait-in-trait-to-assoc-ty flag that lowers the RPIT as a GAT on the trait and on the impls that implement that trait.
Opening this PR as a draft because this goes after #112682, ~#112981~ and ~#112983~.
As soon as those are merged, I can rebase and we should run perf, crater and test a lot.
r? `@compiler-errors`
Don't call `query_normalize` when reporting similar impls
Firstly, It's sketchy to be using `query_normalize` at all during HIR typeck -- it's asking for an ICE 😅. Secondly, we're normalizing an impl trait ref that potentially has parameter types in `ty::ParamEnv::empty()`, which is kinda sketchy as well.
The only UI test change from removing this normalization is that we don't evaluate anonymous constants in impls, which end up giving us really ugly suggestions:
```
error[E0277]: the trait bound `[X; 35]: Default` is not satisfied
--> /home/gh-compiler-errors/test.rs:4:5
|
4 | <[X; 35] as Default>::default();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `[X; 35]`
|
= help: the following other types implement trait `Default`:
&[T]
&mut [T]
[T; 32]
[T; core::::array::{impl#30}::{constant#0}]
[T; core::::array::{impl#31}::{constant#0}]
[T; core::::array::{impl#32}::{constant#0}]
[T; core::::array::{impl#33}::{constant#0}]
[T; core::::array::{impl#34}::{constant#0}]
and 27 others
```
So just fold the impls with a `BottomUpFolder` that calls `ty::Const::eval`. This doesn't work totally correctly with generic-const-exprs, but it's fine for stable code, and this is error reporting after all.
Reveal opaques in new solver
We were testing against the wrong reveal mode 😨
Also a couple of misc commits that I don't want to really put in separate prs
r? ``@lcnr``
Rollup of 8 pull requests
Successful merges:
- #113413 (Add needs-triage to all new issues)
- #113426 (Don't ICE in `resolve_bound_vars` when associated return-type bounds are in bad positions)
- #113427 (Remove `variances_of` on RPITIT GATs, remove its one use-case)
- #113441 (miri: check that assignments do not self-overlap)
- #113453 (Remove unused from_method from rustc_on_unimplemented)
- #113456 (Avoid calling report_forbidden_specialization for RPITITs)
- #113466 (Update cargo)
- #113467 (Fix comment of `fn_can_unwind`)
r? `@ghost`
`@rustbot` modify labels: rollup
Remove chalk support from the compiler
Removes chalk (`-Ztrait-solver=chalk`) from the compiler and prunes any dead code resulting from this, mainly:
* Remove the chalk compatibility layer in `compiler/rustc_traits/src/chalk`
* Remove the chalk flag `-Ztrait-solver=chalk` and its `TraitEngine` implementation
* Remove `TypeWellFormedFromEnv` (and its many `bug!()` match arms)
* Remove the chalk migration mode from compiletest
* Remove the `chalkify` UI tests (do we want to keep any of these, but migrate them to `-Ztrait-solver=next`??)
Fulfills rust-lang/types-team#93.
r? `@jackh726`
Make RPITITs assume/require their parent method's predicates
Removes a FIXME from the `param_env` query where we were manually adding the parent function's predicates to the RPITIT's assumptions.
r? `@spastorino`
Error when RPITITs' hidden types capture more lifetimes than their trait definitions
This implements a stricter set of captures rules for RPITITs. They now may only capture:
1. Lifetimes from the impl header (both the self type and any trait substs -- we may want to restrict just to the self type's lifetimes, but the PR makes that easy to do, too)
2. Lifetimes mentioned by the `impl Trait` in the trait method's definition.
Namely, they may not mention lifetimes from the method (early or late) that are not mentioned in the `impl Trait`.
cc #105258 which I think was trying to do this too, though I'm not super familiar with what exactly differs from that or why that one was broken.
cc #112194 (doesn't fix this issue per se, because it's still an open question, but I think this is objectively better than the status quo, and gets us closer to resolving that issue.)
Technically is a fix for the ICE in #108580, but it turns that issue into an error now. We can decide separately whether or not nested RPITITs should capture lifetimes from their parents.
r? ``@oli-obk``
Encode item bounds for `DefKind::ImplTraitPlaceholder`
This was lost in a refactoring -- `hir::ItemKind::OpaqueTy` doesn't always map to `DefKind::Opaque`, specifically for RPITITs, so the check was migrated subtly wrong, and unfortunately I never had a test for this 🙃Fixes#113155
r? ``@cjgillot``
Account for late-bound vars from parent arg-position impl trait
We should be reporting an error like we do for late-bound args coming from a parent APIT.
Fixes#113016
