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.
libstd miri tests: avoid warnings
Ignore tests in a way that all the code still gets compiled, to get rid of all the "unused" warnings that otherwise show up when running the test suite in Miri.
resolve: Resolve visibilities on fields with non-builtin attributes
Follow-up to https://github.com/rust-lang/rust/pull/66669.
The first commit is primary (and also a backport candidate), the other ones are further cleanups.
In this case it's not strictly necessary to avoid reporting errors during speculative resolution because 1) all visibilities are resolved non-speculatively sooner or later and 2) error reporting infrastructure merges identical errors with identical spans anyway.
Fixes https://github.com/rust-lang/rust/issues/67006
r? @matthewjasper
Format libcore with rustfmt (including tests and benches)
Important: two small non-rustfmt changes that will need close review:
- I added `#[rustfmt::skip]` to two manually arranged tables in src/libcore/benches/ascii.rs; see first commit in the PR.
- I added `// ignore-tidy-filelength` to src/libcore/ptr/mod.rs because rustfmt puts it over tidy's 3000 line limit; see second commit in the PR. I filed #66891 to follow up on breaking up that file. For now though having it be formatted is more important than having it below the line limit.
---
As with my previous formatting PRs, I am avoiding causing merge conflicts in other PRs by only touches those files that are not involved in any currently open PR. Files that appear in new PRs between when this PR is opened and when it makes it to the top of the bors queue will be reverted from this PR.
The list of files involved in open PRs is determined by querying GitHub's GraphQL API [with this script](https://gist.github.com/dtolnay/aa9c34993dc051a4f344d1b10e4487e8).
With the list of files from the script in outstanding_files, the relevant commands were:
```
$ find src/libcore -name '*.rs' \
| xargs rustfmt --edition=2018 --unstable-features --skip-children
$ rg libcore outstanding_files | xargs git checkout --
```
To confirm no funny business:
```
$ git checkout $THIS_COMMIT^
$ git show --pretty= --name-only $THIS_COMMIT \
| xargs rustfmt --edition=2018 --unstable-features --skip-children
$ git diff $THIS_COMMIT # there should be no difference
```
r? @Dylan-DPC
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 ?)
Move clean types into their own file
This PR is just about moving clean types into their own files to make the code more clear and keep all `Clean` trait implementations on their own.
r? @kinnison
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
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
bors
Tyler Mandry
Bartłomiej Kuras
Vadim Petrochenkov
Lzu Tao
Yuki Okushi
Peter
Matthew Kraai
Ralf Jung
Mazdak Farrokhzad
Nathan Ringo
Konrad Borowski