Add `lazy_type_alias` feature gate
Add the `type_alias_type` to be able to have the weak alias used without restrictions.
Part of #112792.
cc `@compiler-errors`
r? `@oli-obk`
[rustdoc] partially fix invalid files creation
Part of #111249. It only removes generation for modules which shouldn't exist. For files, we need the compiler to keep re-export information alive for external items so we can actually have the right path to their location as it's currently not generating them correctly.
In case the item is inlined, it shouldn't (and neither should its children) get a file generated.
r? ```@notriddle```
Syntactically accept `become` expressions (explicit tail calls experiment)
This adds `ast::ExprKind::Become`, implements parsing and properly gates the feature.
cc `@scottmcm`
Add a fully fledged `Clause` type, rename old `Clause` to `ClauseKind`
Does two basic things before I put up a more delicate set of PRs (along the lines of #112714, but hopefully much cleaner) that migrate existing usages of `ty::Predicate` to `ty::Clause` (`predicates_of`/`item_bounds`/`ParamEnv::caller_bounds`).
1. Rename `Clause` to `ClauseKind`, so it's parallel with `PredicateKind`.
2. Add a new `Clause` type which is parallel to `Predicate`.
* This type exposes `Clause::kind(self) -> Binder<'tcx, ClauseKind<'tcx>>` which is parallel to `Predicate::kind` 😸
The new `Clause` type essentially acts as a newtype wrapper around `Predicate` that asserts that it is specifically a `PredicateKind::Clause`. Turns out from experimentation[^1] that this is not negative performance-wise, which is wonderful, since this a much simpler design than something that requires encoding the discriminant into the alignment bits of a predicate kind, or something else like that...
r? ``@lcnr`` or ``@oli-obk``
[^1]: https://github.com/rust-lang/rust/pull/112714#issuecomment-1595653910
Rustdoc: search: color item type and reduce size to avoid clashing
- rustdoc: search: color item type same as item
- rustdoc: search: reduce item type size to 0.875rem to avoid clashing with path and item
Add gha problem matcher
These regexes capture rustfmt errors, panics and regular Rust errors in CI and automatically add messages in the diff view. This should make it simpler to quickly see what went wrong without having to scroll through CI logs.
We can fine tune the regexes or add more matchers after having a look at how it actually works in practice
The relevant documentation can be found at https://github.com/actions/toolkit/blob/main/docs/problem-matchers.md
r? `@jyn514`
Treat TAIT equation as always ambiguous in coherence
Not sure why we weren't treating all TAIT equality as ambiguous -- this behavior combined with `DefineOpaqueTypes::No` leads to coherence overlap failures, since we incorrectly consider impls as not overlapping because the obligation `T: From<Foo>` doesn't hold.
Fixes#112765
Fixes 5686
For reference, explicit discriminants were proposed in [RFC-2363].
`ast::Variant` spans extend to include explicit discriminants when they
are present.
Now we'll adjust the span of enum variants to exclude any explicit
discriminant.
[RFC-2363]: https://rust-lang.github.io/rfcs/2363-arbitrary-enum-discriminant.html
Fixes 5729
`parse_attribute` will panic if the first token is not a `#`. To prevent
this we return early instead of trying to parse an invalid attribute.
Don't try to auto-bless 32-bit `mir-opt` tests on ARM Mac hosts
#112418 added special support for automatically blessing 32-bit output on 64-bit hosts, for the subset of `mir-opt` tests that are pointer-width-dependent.
This relies on the 64-bit host having some corresponding 32-bit target that can be built “easily”. For most 64-bit hosts this is fine, but ARM Macs don't have a corresponding 32-bit target. (There have never been 32-bit ARM Macs, and ARM Macs don't have the libraries needed for building `i686-apple-darwin`.)
There is an entry for `("i686-apple-darwin", "aarch64-apple-darwin")` in the list of corresponding 32-bit platforms, but this doesn't actually work on ARM Macs. Instead, the bootstrap invocation fails to build the necessary 32-bit target support, and nothing gets tested or blessed.
According to [this Zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/Can't.20bless.20any.20mir-opt.20tests.20on.20aarch64.20Mac/near/367109789), that mapping was only added because the author assumed it would work. But since it doesn't actually work on ARM Macs, the solution is to just remove that mapping.
With the mapping removed, ARM Macs still can't auto-bless 32-bit output (they will see a warning instead), but at least they can now bless the output of `mir-opt` tests that don't care about pointer width.
bootstrap: check for dry run when copying env vars for msvc
The new synthetic targets for mir-opt blessing aren't added to `builder.cc` during dry runs, causing `x.py test tests/mir-opt --bless` to crash on MSVC when it tries to copy env vars to the C compiler invocation. This PR adds a check for dry run to fix the panic.
Blessing 32-bit tests on 64-bit hosts relies on having a corresponding 32-bit
target that can be built "easily" on those hosts.
ARM Macs don't have a corresponding 32-bit target, so trying to build one is
usually going to fail.
