[stable] 1.62.1 release
This bundles:
* Windows: Fallback for overlapped I/O #98950
* don't succeed evaluate_obligation query if new opaque types were registered #98614
* Mitigate MMIO stale data vulnerability #98126
* Return a FxIndexSet in is_late_bound query. #99219
Also bumps the version number to 1.62.1 and includes a short release notes section for the release.
r? `@Mark-Simulacrum`
[beta] Fail gracefully when encountering an HRTB in APIT.
Backport of https://github.com/rust-lang/rust/pull/97683
The diagnostic is a bit worse, but still better than an ICE.
r? `@ehuss`
[beta] Beta backports
* Remove the unused-#[doc(hidden)] logic from the unused_attributes lint #98336
* debuginfo: Fix NatVis for Rc and Arc with unsized pointees. #98137
* Revert "remove num_cpus dependency" in rustc and update cargo #97911
* Update LLVM submodule #97690
* Revert #96682. #97636
* don't do Sized and other return type checks on RPIT's real type #97431
* Temporarily disable submodule archive downloads. #98423
Temporarily disable submodule archive downloads.
The `llvm-project` `/archive/` download has been timing out with a 504 error since yesterday. This changes it so that it uses a normal submodule clone, but also uses `--depth 1` since GitHub now supports `allowReachableSHA1InWant` which allows for fetching a specific revision. That should be reasonably fast (but not as fast as an archive download) to unstick CI.
Remove the unused-`#[doc(hidden)]` logic from the `unused_attributes` lint
Fixes#96890.
It was found out that `#[doc(hidden)]` on trait impl items does indeed have an effect on the generated documentation (see the linked issue). In my opinion and the one of [others](https://rust-lang.zulipchat.com/#narrow/stream/266220-rustdoc/topic/Validy.20checks.20for.20.60.23.5Bdoc.28hidden.29.5D.60/near/281846219), rustdoc's output is actually a bit flawed in that regard but that should be tracked in a new issue I suppose (I will open an issue for that in the near future).
The check was introduced in #96008 which is marked to be part of version `1.62` (current `beta`). As far as I understand, this means that **this PR needs to be backported** to `beta` to fix#96890 on time. Correct me if I am wrong.
CC `@dtolnay` (in case you would like to agree or disagree with my decision to fully remove this check)
`@rustbot` label A-lint T-compiler T-rustdoc
r? `@rust-lang/compiler`
debuginfo: Fix NatVis for Rc and Arc with unsized pointees.
Currently, the NatVis for `Rc<T>` and `Arc<T>` does not support unsized `T`. For both `Rc<T>` and `Rc<dyn SomeTrait>` the visualizers fail:
```txt
[Reference count] : -> must be used on pointers and . on structures
[Weak reference count] : -> must be used on pointers and . on structures
```
This PR fixes the visualizers. For slices we can even give show the elements, so one now gets something like:
```txt
slice_rc : { len=3 }
[Length] : 3
[Reference count] : 41
[Weak reference count] : 2
[0] : 1
[1] : 2
[2] : 3
```
r? `@wesleywiser`
Revert "remove num_cpus dependency" in rustc and update cargo
Fixes#97549. This PR reverts #94524 and does a Cargo update to pull in rust-lang/cargo#10737.
Rust 1.61.0 has a regression in which it misidentifies the number of available CPUs in some environments, leading to enormously increased memory usage and failing builds. In between Rust 1.60 and 1.61 both rustc and cargo replaced some uses of `num_cpus` with `available_parallelism`, which eliminated support for cgroupv1, still apparently in common use. This PR switches both rustc and cargo back to using `num_cpus` in order to support environments where the available parallelism is controlled by cgroupv1. Both can use `available_parallism` again once it handles cgroupv1 (if ever).
I have confirmed that the rustc part of this PR fixes the memory usage regression in my non-Cargo environment, and others have confirmed in #97549 that the Cargo regression was at fault for the memory usage regression in their environments.
Revert #96682.
The change was "Show invisible delimiters (within comments) when pretty
printing". It's useful to show these delimiters, but is a breaking
change for some proc macros.
Fixes#97608.
r? ``@petrochenkov``
don't do `Sized` and other return type checks on RPIT's real type
Fixes an ICE where we're doing `Sized` check against the RPIT's real type, instead of against the opaque type. This differs from what we're doing in MIR typeck, which causes ICE #97226.
This regressed in #96516 -- this adjusts that fix to be a bit more conservative. That PR was backported and thus the ICE is also present in stable. Not sure if it's worth to beta and/or stable backport, probably not the latter but I could believe the former.
r? `@oli-obk`
cc: another attempt to fix this ICE #97413. I believe this PR addresses the root cause.
Allow the unused_macro_rules lint for now
It was newly added by #96150 with warn by default, which is great as it gave exposure to the community, and their feedback gave me ideas for improvements.
Allowing the lint is good for two reasons:
* It makes the transition easier as e.g. allow directives won't fire the unknown lint warning once it is turned to warn by default in the future. The [commit that allowed the lint in fuchsia](https://fuchsia.googlesource.com/fuchsia/+/9d8f96517c3963de2f0e25598fd36061914524cd%5E%21/) had to allow unknown lints for example.
This is especially important compared to other lints in the unused group,
because the _ prefix trick doesn't exist for macro rules, allowing is the
only option (either of unused_macro_rules, or of the entire unused group,
but that is not as informative to readers). Allowing the lint also makes it
possible to work on possible heuristics for disabling the macro in specific
cases.
* It gives time for implementing heuristics for when to suppress the lint, e.g.
when `compile_error!` is invoked by that arm (so it's only there to yield an error).
See: https://github.com/rust-lang/rust/pull/96150#issuecomment-1126599107
I would also like this to be backported to the 1.62 beta branch (cc #97016).
bors