Report higher-ranked trait error when higher-ranked projection goal fails in new solver
~~See HACK comment inline. Not actually sure if it should be marked as a *HACK*, b/c~~ it's kinda a legitimate case we want to care about unless we're going to make the proof tree visitor *smarter* about the leak check than the actual trait solver itself.
Encountered this while battling with `NiceRegionError`s in the old solver b/c I wondered what this code ended up giving us in the *new* solver as a comparison:
```rust
trait Foo {}
impl<T: FnOnce(&())> Foo for T {}
fn baz<T: Foo>() {}
fn main() {
baz::<fn(&'static ())>();
}
```
On master it's pretty bad:
```
error[E0271]: type mismatch resolving `<fn(&()) as FnOnce<(&(),)>>::Output == ()`
--> <source>:8:11
|
8 | baz::<fn(&'static ())>();
| ^^^^^^^^^^^^^^^ types differ
|
note: required for `fn(&'static ())` to implement `Foo`
--> <source>:3:22
|
3 | impl<T: FnOnce(&())> Foo for T {}
| ----------- ^^^ ^
| |
| unsatisfied trait bound introduced here
```
After this PR it's much better:
```
error[E0277]: the trait bound `fn(&'static ()): Foo` is not satisfied
--> /home/mgx/test.rs:8:11
|
8 | baz::<fn(&'static ())>();
| ^^^^^^^^^^^^^^^ the trait `for<'a> FnOnce(&'a ())` is not implemented for `fn(&'static ())`
|
= note: expected a closure with arguments `(&'static (),)`
found a closure with arguments `(&(),)`
note: required for `fn(&'static ())` to implement `Foo`
--> /home/mgx/test.rs:3:22
|
3 | impl<T: FnOnce(&())> Foo for T {}
| ----------- ^^^ ^
| |
| unsatisfied trait bound introduced here
note: required by a bound in `baz`
--> /home/mgx/test.rs:5:11
|
5 | fn baz<T: Foo>() {}
| ^^^ required by this bound in `baz`
```
r? lcnr
compiletest: Add directive `dont-require-annotations`
for making matching on specific diagnostic kinds non-exhaustive.
E.g. `//@ dont-require-annotations:ERROR`, like in the examples in this PR.
cc https://github.com/rust-lang/rust/pull/139427#issuecomment-2782827583Closes#132647 FYI `@BoxyUwU` since you've wanted this.
r? `@jieyouxu`
speed up `String::push` and `String::insert`
Addresses the concerns described in #116235.
The performance gain comes mainly from avoiding temporary buffers.
Complex pattern matching in `encode_utf8` (introduced in #67569) has been simplified to a comparison and an exhaustive `match` in the `encode_utf8_raw_unchecked` helper function. It takes a slice of `MaybeUninit<u8>` because otherwise we'd have to construct a normal slice to uninitialized data, which is not desirable, I guess.
Several functions still have that [unneeded zeroing](https://rust.godbolt.org/z/5oKfMPo7j), but a single instruction is not that important, I guess.
`@rustbot` label T-libs C-optimization A-str
We should enable these to avoid misinterpreting uses of the extended
syntax as code blocks. This happens in practice with multi-paragraph
footnotes, as discovered in #139064.
Rollup of 7 pull requests
Successful merges:
- #138869 (Try not to use verbatim paths in `Command::current_dir`)
- #138993 (Make `cfg_match!` a semitransparent macro)
- #139099 (Promise `array::from_fn` is generated in order of increasing indices)
- #139364 (Make the compiler suggest actual paths instead of visible paths if the visible paths are through any doc hidden path.)
- #139468 (Don't call `Span::with_parent` on the good path in `has_stashed_diagnostic`)
- #139481 (Add job summary links to post-merge report)
- #139573 (Miri subtree update)
r? `@ghost`
`@rustbot` modify labels: rollup
Add job summary links to post-merge report
This should make it much easier to investigate the individual job test/duration changes.
The GitHub API handling is a bit crude, but I didn't want to include octocrab, because it more than doubles the current number of dependencies of `citool`...
Can be tested with:
```bash
$ cargo run --manifest-path src/ci/citool/Cargo.toml post-merge-report bad13a970a1e008dd5d8
```
r? ```@marcoieni```
Don't call `Span::with_parent` on the good path in `has_stashed_diagnostic`
More unnecessary incurred span tracking avoided by not calling `span.with_parent(None)`. This is useless on its own but makes it much easier to fix other "span tracking on the good path" issues in the future.
r? oli-obk
Make the compiler suggest actual paths instead of visible paths if the visible paths are through any doc hidden path.
close#127011
Currently, when emitting a diagnostic about a valid trait, the compiler suggestes using visible paths of the trait even if they are through a doc hidden path. This PR updates the compiler to suggest actual paths in these cases.
Promise `array::from_fn` is generated in order of increasing indices
Fixes#139061
I agree this needs to be documented because of the `FnMut`, either with a guarantee or to explicitly disclaim one.
I'm pretty sure this will be non-controversial (like the other "well sure you *could* do it in a different order, but why?" things were), but I couldn't find any previous libs-api decision on it so it's seemingly a new promise that will need FCP.
Basically, yes, it would be plausible to fill in the reverse order, but there's no obvious way we could ever know that that might even be a good idea, so forward seems like an easy thing to promise. We could always add a `from_fn_rev` or something later if there's ever a strong enough need, but it seems unlikely.
Let's just do the obvious thing so it matches what `[gen(0), gen(1), …, gen(N-1)]` does.
Make `cfg_match!` a semitransparent macro
IIUC this is preferred when (potentially) stabilizing `macro` items, to avoid potentially utilizing def-site hygiene instead of mixed-site.
Tracking issue: #115585
Try not to use verbatim paths in `Command::current_dir`
If possible, we should try not to use verbatim paths in `Command::current_dir`. It might work but it might also break code in the subprocess that assume the current directory isn't verbatim (including Windows APIs). cc ``@ehuss``
Side note: we now have a lot of ad-hoc fixes like this spread about the place. It'd be good to make a proper `WindowsPath` type that handles all this in one place. But that's a bigger job for another PR.
There's an existing fast path for the `type_op_prove_predicate`
predicate, checking for trivially `Sized` types, which can be re-used
when evaluating obligations within queries. This should improve
performance, particularly in anticipation of new sizedness traits being
added which can take advantage of this.
Allow GVN to produce places and not just locals.
That may be too big of a hammer, as we may introduce new deref projections (possible UB footgun + probably not good for perf).
The second commit opts out of introducing projections that don't have a stable offset, which is probably what we want. Hence no new Deref and no new Index projections.
Fixes https://github.com/rust-lang/rust/issues/138936
cc `@scottmcm` `@dianqk`
Currently in case of a Trait object in closure parameter, the compiler
suggests either to use a reference, which is correct or to use an
`impl Trait` which is not. Do not emit this suggestion when the parameter
is part of a closure.
`resolve_ident_in_lexical_scope` checks for an empty name. Why is this
necessary? Because `parse_item_impl` can produce an `impl` block with an
empty trait name in some cases. This is pretty gross and very
non-obvious.
This commit avoids the use of the empty trait name. In one case the
trait name is instead pulled from `TyKind::ImplTrait`, which prevents
the output for `tests/ui/impl-trait/extra-impl-in-trait-impl.rs` from
changing. In the other case we just fail the parse and don't try to
recover. I think losing error recovery in this obscure case is worth
the code cleanup.
This change affects `tests/ui/parser/impl-parsing.rs`, which is split in
two, and the obsolete `..` syntax cases are removed (they are tested
elsewhere).
