rustdoc: inherit parent's stability where applicable
It is currently not possible for a re-export to have a different stability (https://github.com/rust-lang/rust/issues/30827). Therefore the standard library uses a hack when moving items like `std::error::Error` or `std::net::IpAddr` into `core` by marking the containing module (`core::error` / `core::net`) as unstable or stable in a later version than the items the module contains.
Previously, rustdoc would always show the *stability as declared* for an item rather than the *stability as publicly reachable* (i.e. the features required to actually access the item), which could be confusing when viewing the docs. This PR changes it so that we show the stability of the first unstable parent or the most recently stabilized parent instead, to hopefully make things less confusing.
fixes https://github.com/rust-lang/rust/issues/130765
screenshots:
 
Separate collection of crate-local inherent impls from error tracking
#119895 changed the return type of the `crate_inherent_impls` query from `CrateInherentImpls` to `Result<CrateInherentImpls, ErrorGuaranteed>` to avoid needing to use the non-parallel-friendly `track_errors()` to track if an error was reporting from within the query... This was mostly fine until #121113, which stopped halting compilation when we hit an `Err(ErrorGuaranteed)` in the `crate_inherent_impls` query.
Thus we proceed onwards to typeck, and since a return type of `Result<CrateInherentImpls, ErrorGuaranteed>` means that the query can *either* return one of "the list inherent impls" or "error has been reported", later on when we want to assemble method or associated item candidates for inherent impls, we were just treating any `Err(ErrorGuaranteed)` return value as if Rust had no inherent impls defined anywhere at all! This leads to basically every inherent method call failing with an error, lol, which was reported in #127798.
This PR changes the `crate_inherent_impls` query to return `(CrateInherentImpls, Result<(), ErrorGuaranteed>)`, i.e. returning the inherent impls collected *and* whether an error was reported in the query itself. It firewalls the latter part of that query into a new `crate_inherent_impls_validity_check` just for the `ensure()` call.
This fixes#127798.
Improve assembly test for CMSE ABIs
Tracking issues: #75835#81391
This ensures the code-gen for these ABIs does not change silently. There is a small chance that this code-gen might change, however even GCC (https://godbolt.org/z/16arxab5x and https://godbolt.org/z/16arxab5x) generates almost the same assembly for these ABIs. I hope the notes in the comments should help fix the tests if it ever breaks.
Fix cargo staging for run-make tests
Follow-up to https://github.com/rust-lang/rust/pull/130642#issuecomment-2366891866 to make sure that when
```
$ COMPILETEST_FORCE_STAGE0=1 ./x test run-make --stage 0
```
is used, bootstrap cargo is used in order to avoid building stage 1 rustc. Note that run-make tests are usually not written with `--stage 0` in mind and some tests may rely on stage1 rustc (nightly) behavior, and it is expected that some tests will fail under this invocation.
This PR also fixes `tool::Cargo` staging in compiletest when preparing for `run-make` test mode, by chopping off a stage from the `compiler` passed to `tool::Cargo` such that when the user invokes with stage `N`
```
./x test run-make --stage N
```
the `run-make` test suite will be tested against the cargo built by stage `N` compiler. Let's take `N=1`, i.e. `--stage 1`, without chopping off a stage, previously `./x test run-make --stage 1` will cause stage 1 rustc + std to be built, then stage 2 rustc, and cargo will be produced by the stage 2 rustc, which is clearly not what we want. By chopping off a stage, it means that cargo will be produced by the stage 1 rustc.
cc #119946, #59864.
See discussions regarding the tool staging at https://rust-lang.zulipchat.com/#narrow/stream/326414-t-infra.2Fbootstrap/topic/.E2.9C.94.20stage1.20run-make.20tests.20now.20need.20stage2.20rustc.20built.20for.20c.2E.2E.2E.
This changes the remaining span for the cast, because the new `Cast`
category has a higher priority (lower `Ord`) than the old `Coercion`
category, so we no longer report the region error for the "unsizing"
coercion from `*const Trait` to itself.
Revert "Apply EarlyOtherwiseBranch to scalar value #129047"
This reverts PR #129047, commit a772336fb3, reversing changes made to 702987f75b.
cc `@DianQK` and `@cjgillot` as the PR author and reviewer of #129047 respectively.
It seems [Apply EarlyOtherwiseBranch to scalar value #129047](https://github.com/rust-lang/rust/pull/129047) may have lead to several nightly regressions:
- https://github.com/rust-lang/rust/issues/130769
- https://github.com/rust-lang/rust/issues/130774
- https://github.com/rust-lang/rust/issues/130771
Example test that would ICE with changes in #129047 (this test is included in this PR):
```rs
//@ compile-flags: -C opt-level=3
//@ check-pass
use std::task::Poll;
pub fn poll(val: Poll<Result<Option<Vec<u8>>, u8>>) {
match val {
Poll::Ready(Ok(Some(_trailers))) => {}
Poll::Ready(Err(_err)) => {}
Poll::Ready(Ok(None)) => {}
Poll::Pending => {}
}
}
```
Since this is a mir-opt ICE that seems to quite easy to trigger with real-world crates being affected, let's revert for now and reland the mir-opt after these are fixed.
Revert "Add recursion limit to FFI safety lint"
It's not necessarily clear if warning when we hit the recursion limit is the right thing to do, first of all.
**More importantly**, this PR was implemented incorrectly in the first place; it was not decrementing the recursion limit when stepping out of a type, so it would trigger when a ctype has more than RECURSION_LIMIT fields *anywhere* in the type's set of recursively reachable fields.
Reverts #130598Reopens#130310Fixes#130757
Rework `non_local_definitions` lint to only use a syntactic heuristic
This PR reworks the `non_local_definitions` lint to only use a syntactic heuristic, i.e. not use a type-system logic for whenever an `impl` is local or not.
Instead the new logic wanted by T-lang in https://github.com/rust-lang/rust/issues/126768#issuecomment-2192634762, which is to consider every paths in `Self` and `Trait` and to no longer use the type-system inference trick.
`@rustbot` labels +L-non_local_definitions
Fixes#126768
add unqualified_local_imports lint
This lint helps deal with https://github.com/rust-lang/rustfmt/issues/4709 by having the compiler detect imports of local items that are not syntactically distinguishable from imports from other cates. Making them syntactically distinguishable ensures rustfmt can consistently apply the desired import grouping.
Fix `break_last_token`.
It currently doesn't handle the three-char tokens `>>=` and `<<=` correctly. These can be broken twice, resulting in three individual tokens. This is a latent bug that currently doesn't cause any problems, but does cause problems for #124141, because that PR increases the usage of lazy token streams.
r? `@petrochenkov`
Apply `EarlyOtherwiseBranch` to scalar value
In the future, I'm thinking of hoisting discriminant via GVN so that we only need to write very little code here.
r? `@cjgillot`
tests: Remove spuriously failing vec-tryinto-array codegen test
This has failed more than a couple of times now. It costs real time, money, and energy to deal with this, far more than this test is saving us.
Introduce `structurally_normalize_const`, use it in `rustc_hir_typeck`
Introduces `structurally_normalize_const` to typecking to separate the "eval a const" step from the "try to turn a valtree into a target usize" in HIR typeck, where we may still have infer vars and stuff around.
I also changed `check_expr_repeat` to move a double evaluation of a const into a single one. I'll leave inline comments.
r? ```@BoxyUwU```
I hesitated to really test this on the new solver where it probably matters for unevaluated consts. If you're worried about the side-effects, I'd be happy to craft some more tests 😄
Don't call `ty::Const::normalize` in error reporting
We do this to ensure that trait refs with unevaluated consts have those consts simplified to their evaluated forms. Instead, use `try_normalize_erasing_regions`.
**NOTE:** This has the side-effect of erasing regions from all of our trait refs. If this is too much to review or you think it's too opinionated of a diagnostics change, then I could split out the effective change (i.e. erasing regions from this impl suggestion) into another PR and have someone else review it.
No longer mark RTN as incomplete
The RFC is accepted and the feature is basically fully implemented. This doesn't mean it's necesarily *ready* for stabiliation; there's probably some diagnostic improvements to be made, and as always, users uncover the most creative bugs.
But marking this feature as incomplete no longer serves any purpose, so let's fix that.
Handle unsized consts with type `str` in v0 symbol mangling
This PR fixes#116303 by handling consts with type `str` in v0 symbol mangling as partial support for unsized consts.
This PR is related to `#![feature(adt_const_params)]` (#95174) and `#![feature(unsized_const_params)]` (#128028).
r? ``@BoxyUwU``
Add str.as_str() for easy Deref to string slices
Working with `Box<str>` is cumbersome, because in places like `iter.filter()` it can end up being `&Box<str>` or even `&&Box<str>`, and such type doesn't always get auto-dereferenced as expected.
Dereferencing such box to `&str` requires ugly syntax like `&**boxed_str` or `&***boxed_str`, with the exact amount of `*`s.
`Box<str>` is [not easily comparable with other string types](https://github.com/rust-lang/rust/pull/129852) via `PartialEq`. `Box<str>` won't work for lookups in types like `HashSet<String>`, because `Borrow<String>` won't take types like `&Box<str>`. OTOH `set.contains(s.as_str())` works nicely regardless of levels of indirection.
`String` has a simple solution for this: the `as_str()` method, and `Box<str>` should too.
It currently doesn't handle the three-char tokens `>>=` and `<<=`
correctly. These can be broken twice, resulting in three individual
tokens. This is a latent bug that currently doesn't cause any problems,
but does cause problems for #124141, because that PR increases the usage
of lazy token streams.
