const_generics: correctly deal with bound variables
removes the hack in `resolve` which was needed because we evaluated constants without caring about their bound variables.
Each commit should be fairly self-contained, even if they build on each other
r? `@jackh726`
Migrate another part of rustc_infer to session diagnostic
Probably will migrate another file before marking this one as ready-to-merge.
`@rustbot` label +A-translation
r? rust-lang/diagnostics
cc https://github.com/rust-lang/rust/issues/100717
Update `SessionDiagnostic::into_diagnostic` to take `Handler` instead of `ParseSess`
Suggested by the team in [this Zulip Topic](https://rust-lang.zulipchat.com/#narrow/stream/336883-i18n/topic/.23100717.20SessionDiagnostic.20on.20Handler).
`Handler` already has almost all the capabilities of `ParseSess` when it comes to diagnostic emission, in this migration we only needed to add the ability to access `source_map` from the emitter in order to get a `Snippet` and the `start_point`. Not sure if adding these two methods [`span_to_snippet_from_emitter` and `span_start_point_from_emitter`] is the best way to address this gap.
P.S. If this goes in the right direction, then we probably may want to move `SessionDiagnostic` to `rustc_errors` and rename it to `DiagnosticHandler` or something similar.
r? `@davidtwco`
r? `@compiler-errors`
Suggested by the team in this Zulip Topic https://rust-lang.zulipchat.com/#narrow/stream/336883-i18n/topic/.23100717.20SessionDiagnostic.20on.20Handler
Handler already has almost all the capabilities of ParseSess when it comes to diagnostic emission, in this migration we only needed to add the ability to access source_map from the emitter in order to get a Snippet and the start_point. Not sure if this is the best way to address this gap
This PR will fix some typos detected by [typos].
I only picked the ones I was sure were spelling errors to fix, mostly in
the comments.
[typos]: https://github.com/crate-ci/typos
Attempt to normalize `FnDef` signature in `InferCtxt::cmp`
Stashes a normalization callback in `InferCtxt` so that the signature we get from `tcx.fn_sig(..).subst(..)` in `InferCtxt::cmp` can be properly normalized, since we cannot expect for it to have normalized types since it comes straight from astconv.
This is kind of a hack, but I will say that `@jyn514` found the fact that we present unnormalized types to be very confusing in real life code, and I agree with that feeling. Though altogether I am still a bit unsure about whether this PR is worth the effort, so I'm open to alternatives and/or just closing it outright.
On the other hand, this isn't a ridiculously heavy implementation anyways -- it's less than a hundred lines of changes, and half of that is just miscellaneous cleanup.
This is stacked onto #100471 which is basically unrelated, and it can be rebased off of that when that lands or if needed.
---
The code:
```rust
trait Foo { type Bar; }
impl<T> Foo for T {
type Bar = i32;
}
fn foo<T>(_: <T as Foo>::Bar) {}
fn needs_i32_ref_fn(f: fn(&'static i32)) {}
fn main() {
needs_i32_ref_fn(foo::<()>);
}
```
Before:
```
= note: expected fn pointer `fn(&'static i32)`
found fn item `fn(<() as Foo>::Bar) {foo::<()>}`
```
After:
```
= note: expected fn pointer `fn(&'static i32)`
found fn item `fn(i32) {foo::<()>}`
```
Do not leak type variables from opaque type relation
The "root cause" is that we call `InferCtxt::resolve_vars_if_possible` (3d9dd681f5) on the types we get back in `TypeError::Sorts` since I added a call to it in `InferCtxt::same_type_modulo_infer`. However if this `TypeError` comes from a `InferCtxt::commit_if_ok`, then it may reference type variables that do not exist anymore, which is problematic.
We avoid this by substituting the `TypeError` with the types we had before being generalized while handling opaques.
This is kinda gross, and I feel like we can get the same issue from other places where we generalize type/const inference variables. Maybe not? I don't know.
Fixes#99914Fixes#99970Fixes#100463
Rollup of 9 pull requests
Successful merges:
- #95376 (Add `vec::Drain{,Filter}::keep_rest`)
- #100092 (Fall back when relating two opaques by substs in MIR typeck)
- #101019 (Suggest returning closure as `impl Fn`)
- #101022 (Erase late bound regions before comparing types in `suggest_dereferences`)
- #101101 (interpret: make read-pointer-as-bytes a CTFE-only error with extra information)
- #101123 (Remove `register_attr` feature)
- #101175 (Don't --bless in pre-push hook)
- #101176 (rustdoc: remove unused CSS selectors for `.table-display`)
- #101180 (Add another MaybeUninit array test with const)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Fall back when relating two opaques by substs in MIR typeck
This is certainly _one_ way to fix#100075. Not really confident it's the _best_ way to do it, though.
The root cause of this issue is that during MIR type-check, we end up trying to equate an opaque against the same opaque def-id but with different substs. Because of the way that we replace RPITs during (HIR) typeck with an inference variable, we don't end up emitting a type-checking error, so the delayed MIR bug causes an ICE.
See the `src/test/ui/impl-trait/issue-100075-2.rs` test below to make that clear -- in that example, we try to equate `{impl Sized} substs=[T]` and `{impl Sized} substs=[Option<T>]`, which causes an ICE. This new logic will instead cause us to infer `{impl Sized} substs=[Option<T>]` as the hidden type for `{impl Sized} substs=[T]`, which causes a proper error to be emitted later on when we check that an opaque isn't recursive.
I'm open to closing this in favor of something else. Ideally we'd fix this in typeck, but the thing we do to ensure backwards compatibility with weird RPIT cases makes that difficult. Also open to discussing this further.
Revert let_chains stabilization
This is the revert against master, the beta revert was already done in #100538.
Bumps the stage0 compiler which already has it reverted.
Rollup of 7 pull requests
Successful merges:
- #100898 (Do not report too many expr field candidates)
- #101056 (Add the syntax of references to their documentation summary.)
- #101106 (Rustdoc-Json: Retain Stripped Modules when they are imported, not when they have items)
- #101131 (CTFE: exposing pointers and calling extern fn is just impossible)
- #101141 (Simplify `get_trait_ref` fn used for `virtual_function_elimination`)
- #101146 (Various changes to logging of borrowck-related code)
- #101156 (Remove `Sync` requirement from lint pass objects)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove separate indexing of early-bound regions
~Based on https://github.com/rust-lang/rust/pull/99728.~
This PR copies some modifications from https://github.com/rust-lang/rust/pull/97839 around object lifetime defaults.
These modifications allow to stop counting generic parameters during lifetime resolution, and rely on the indexing given by `rustc_typeck::collect`.
