resolve: Always resolve visibilities on impl items
Fixes https://github.com/rust-lang/rust/issues/64705.
Similarly to https://github.com/rust-lang/rust/pull/67106 this was an issue with visitor discipline.
Impl items were visited as a part of visiting `ast::ItemKind::Impl`, but they should be visit-able in isolation from their parents as well, because that's how they are visited when they are expanded from macros.
I've checked that all the remaining `resolve_visibility` calls are used correctly.
r? @matthewjasper
Fix `-Z print-type-sizes`'s handling of zero-sized fields.
Currently, the type `struct S { x: u32, y: u32, tag: () }` is
incorrectly described like this:
```
print-type-size type: `S`: 8 bytes, alignment: 4 bytes
print-type-size field `.x`: 4 bytes
print-type-size field `.tag`: 0 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size padding: 4 bytes
print-type-size field `.y`: 4 bytes, alignment: 4 bytes
```
Specifically:
- The `padding` line is wrong. (There is no padding.)
- The `offset` and `alignment` on the `.tag` line shouldn't be printed.
The problem is that multiple fields can end up with the same offset, and
the printing code doesn't handle this correctly.
This commit fixes it by adjusting the field sorting so that zero-sized fields
are dealt with before non-zero-sized fields. With that in place, the
printing code works correctly.
The commit also corrects the "something is very wrong" comment.
The new output looks like this:
```
print-type-size type: `S`: 8 bytes, alignment: 4 bytes
print-type-size field `.tag`: 0 bytes
print-type-size field `.x`: 4 bytes
print-type-size field `.y`: 4 bytes
```
r? @pnkfelix
Fix `unused_parens` triggers on macro by example code
Fix#66295
Unfortunately this does also break [an existing test](4787e97475/src/test/ui/lint/issue-47775-nested-macro-unnecessary-parens-arg.rs (L22)). I'm not sure how to handle that, because that seems to be quite similar to the allowed cases
If this gets accepted it would be great to backport this fix to beta.
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
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
Add options to --extern flag.
This changes the `--extern` flag so that it can take a series of options that changes its behavior. The general syntax is `[opts ':'] name ['=' path]` where `opts` is a comma separated list of options. Two options are supported, `priv` which replaces `--extern-private` and `noprelude` which avoids adding the crate to the extern prelude.
```text
--extern priv:mylib=/path/to/libmylib.rlib
--extern noprelude:alloc=/path/to/liballoc.rlib
```
`noprelude` is to be used by Cargo's build-std feature in order to use `--extern` to reference standard library crates.
This also includes a second commit which adds the `aux-crate` directive to compiletest. I can split this off into a separate PR if desired, but it helps with defining these kinds of tests. It is based on #54020, and can be used in the future to replace and simplify some of the Makefile tests.
Fix constant propagation for scalar pairs
We now only propagate a scalar pair if the Rvalue is a tuple with two scalars. This for example avoids propagating a (u8, u8) value when Rvalue has type `((), u8, u8)` (see the regression test). While this is a correct thing to do, implementation is tricky and will be done later.
Fixes#66971Fixes#66339Fixes#67019
Currently, the type `struct S { x: u32, y: u32, tag: () }` is
incorrectly described like this:
```
print-type-size type: `S`: 8 bytes, alignment: 4 bytes
print-type-size field `.x`: 4 bytes
print-type-size field `.tag`: 0 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size padding: 4 bytes
print-type-size field `.y`: 4 bytes, alignment: 4 bytes
```
Specifically:
- The `padding` line is wrong. (There is no padding.)
- The `offset` and `alignment` on the `.tag` line shouldn't be printed.
The problem is that multiple fields can end up with the same offset, and
the printing code doesn't handle this correctly.
This commit fixes it by adjusting the field sorting so that zero-sized fields
are dealt with before non-zero-sized fields. With that in place, the
printing code works correctly.
The commit also corrects the "something is very wrong" comment.
The new output looks like this:
```
print-type-size type: `S`: 8 bytes, alignment: 4 bytes
print-type-size field `.tag`: 0 bytes
print-type-size field `.x`: 4 bytes
print-type-size field `.y`: 4 bytes
```
Ensure that we get a hard error on generic ZST constants if their bod…
…y causes an error during evaluation
cc #67083 (does not fix because we still need the beta backport)
r? @wesleywiser
cc @RalfJung
Use deref target in Pin trait implementations
Using deref target instead of pointer itself avoids providing access to `&Rc<T>` for malicious implementations, which would allow calling `Rc::get_mut`.
This is a breaking change necessary due to unsoundness, however the impact of it should be minimal.
This only fixes the issue with malicious `PartialEq` implementations, other `Pin` soundness issues are still here.
See <https://internals.rust-lang.org/t/unsoundness-in-pin/11311/73> for more details.
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 ?)
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>
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
Emit coercion suggestions in more places
Fixes#66910
We have several different kinds of suggestions we can try to make when
type coercion fails. However, we were previously only emitting these
suggestions from `demand_coerce_diag`. This resulted in the compiler
failing to emit applicable suggestions in several different cases, such
as when the implicit return value of a function had the wrong type.
This commit adds a new `emit_coerce_suggestions` method, which tries to
emit a number of related suggestions. This method is called from both
`demand_coerce_diag` and `CoerceMany::coerce_inner`, which covers a much
wider range of cases than before.
We now suggest using `.await` in more cases where it is applicable,
among other improvements.
I'm not happy about disabling the `issue-59756`, but from what I can tell, the suggestion infrastructure in rustc lacks any way of indicating mutually exclusive suggestions (and compiletest lacks a way to only apply a subset of available suggestions).
We now only propagate a scalar pair if the Rvalue is a tuple with two
scalars. This for example avoids propagating a (u8, u8) value when
Rvalue has type `((), u8, u8)` (see the regression test). While this is
a correct thing to do, implementation is tricky and will be done later.
Fixes#66971Fixes#66339Fixes#67019
