This reverts commit 3ed3b8bb7b, reversing
changes made to 99b89533d4.
We will reland a similar patch at a future date but for now we should get a nightly
released in a few hours with the parallel patch, so this should be
reverted to make sure that the next nightly is not parallel-enabled.
Require stable/unstable annotations for the constness of all stable fns with a const modifier
r? @RalfJung @Centril
Every `#[stable]` const fn now needs either a `#[rustc_const_unstable]` attribute or a `#[rustc_const_stable]` attribute. You can't silently stabilize the constness of a function anymore.
Remove uniform array move MIR passes
This PR fixes a number of bugs caused by limitations of this pass
* Projections from constant indexes weren't being canonicalized
* Constant indexes from the start weren't being canonicalized (they could have different min_lengths)
* It didn't apply to non-moves
This PR makes the following changes to support removing this pass:
* ConstantIndex of arrays are now generated in a canonical form (from the start, min_length is the actual length).
* Subslices are now split when generating move paths and when checking subslices have been moved.
Additionally
* The parent move path of a projection from an array element is now calculated correctly
closes#66502
async/await: improve not-send errors, part 2
Part of #64130. Fixes#65667.
This PR improves the errors introduced in #64895 so that they have specialized messages for `Send` and `Sync`.
r? @nikomatsakis
The reason we were invoking `builtin_deref` was to enable comparisons
when the type was `&T`. For the reasons outlined in the comment, those
comparisons failed because the regions disagreed.
rustc: allow non-empty ParamEnv's in global trait select/eval caches.
*Based on #66963*
This appears to alleviate the symptoms of #65510 locally (without fixing WF directly), and is potentially easier to validate as sound (since it's a more ad-hoc version of queries we already have).
I'm opening this PR primarily to test the effects on perf.
r? @nikomatsakis cc @rust-lang/wg-traits
From a `Vec<Ty>` to a `Vec<InferTy>`, because that's a more restrictive
type. This is a perf win because the ultra-hot function
`shallow_resolve_changed` has less pattern-matching to do.
* `min_length` is now exact for const index elements.
* const index elements are always from the start.
* make array `Subslice` `PlaceElems` count both `from` and `to` from the
start.
In which we implement illegal subset relations errors using Polonius
This PR is the rustc side of implementing subset errors using Polonius. That is, in
```rust
fn foo<'a, 'b>(x: &'a u32, y: &'b u32) -> &'a u32 {
y
}
```
returning `y` requires that `'b: 'a` but we have no evidence of that, so this is an error. (Evidence that the relation holds could come from explicit bounds, or via implied bounds).
Polonius outputs one such error per CFG point where the free region's placeholder loan unexpectedly flowed into another free region. While all these CFG locations could be useful in diagnostics in the future, rustc does not do that (and the duplication is only partially handled in the rest of the errors/diagnostics infrastructure, e.g. duplicate suggestions will be shown by the "outlives suggestions" or some of the `#[rustc_*]` NLL/MIR debug dumps), so I deduplicated the errors.
(The ordering also matters, otherwise some of the elided lifetime naming would change behaviour).
I've blessed a couple of tests, where the output is currently suboptimal:
- the `hrtb-perfect-forwarding` tests mix subset errors with higher-ranked subtyping, however the plan is for chalk to eventually take care of some of this to generate polonius constraints (i.e. it's not polonius' job). Until that happens, polonius will not see the error that NLL sees.
- some other tests have errors and diagnostics specific to `'static`, I _believe_ this to be because of it being treated as more "special" than in polonius. I believe the output is not wrong, but could be better, and appears elsewhere (I feel we'll need to look at polonius' handling of `'static` at some point in the future, maybe to match a bit more what NLL does when it produces errors)
I'll create a tracking issue in the polonius repo to record these 2 points (and a general "we'll need to go over the blessed output" issue, much like we did for NLLs)
The last blessed test is because it's an improvement: in this case, more errors/suggestions were computed, instead of the existing code path where this case apparently stops at the first error.
The `Naive` variant in Polonius computes those errors, so this PR also switches the default variant to that, as we're also in the process of temporarily deactivating all other variants (which exist mostly for performance considerations) until we have completed more work on completeness and correctness, before focusing on efficiency once again.
While most of the correctness in this PR is hidden in the polonius compare-mode (which of course passes locally), I've added a couple of smoke-tests to the existing ones, so that we have some confidence that it works (and keeps working) until we're in a position where we can run them on CI.
As mentioned during yesterday's wg-polonius meeting, @nikomatsakis has already read through most of this PR (and which is matching what they thought needed to be done [during the recent Polonius sprint](https://hackmd.io/CGMNjt1hR_qYtsR9hgdGmw#Compiler-notes-on-generating-the-placeholder-loans-support)), but Matthew was hopefully going to review (again, not urgent), so:
r? @matthewjasper
(This updates to the latest `polonius-engine` release, and I'm not sure whether `Cargo.lock` updates can easily be rolled up, but apart from that: this changes little that's tested on CI, so seems safe-ish to rollup ?)
Update measureme crate to 0.5.0
This PR updates the `measureme` self-profiling crate to the latest release. Heads up, this version changes the trace file format, so the `summarize` tool on perf.rlo needs to be updated to 0.5 too.
r? @Mark-Simulacrum
cc @wesleywiser
This commit corrects the diagnostic note for `async move {}` so that
`await` is mentioned, rather than `yield`.
Signed-off-by: David Wood <david@davidtw.co>
Cleanup BodyCache
After this PR:
- `BodyCache` is renamed to `BodyAndCache`
- `ReadOnlyBodyCache` is renamed to `ReadOnlyBodyAndCache`
- `ReadOnlyBodyAndCache::body` fn is removed and all calls to it are replaced by a deref (possible due to fix of its `Deref` imp in #65947)
cc @eddyb @oli-obk
Change unused_labels from allow to warn
Fixes#66324, making the unused_labels lint warn instead of allow by default. I'm told @rust-lang/lang will need to review this, and perhaps will want to do a crater run.
Miri core engine: use throw_ub instead of throw_panic
See https://github.com/rust-lang/rust/issues/66902 for context: panicking is not really an "interpreter error", but just part of a normal Rust execution. This is a first step towards removing the `InterpError::Panic` variant: the core Miri engine does not use it any more.
ConstProp and ConstEval still use it, though. This will be addressed in future PRs.
From what I can tell, all the error messages this removes are actually duplicates.
r? @oli-obk @wesleywiser
Rename `bool::then_*` to `bool::to_option_*` and use where appropriate
Name change following https://github.com/rust-lang/rfcs/pull/2757. Also try it out throughout the compiler in places I think makes the code more readable.
