MIPS64 targets under OpenWrt require soft-float fpu support.

Rust-lang requires soft-float defined in tuple definition and
isn't over-ridden by toolchain compile-time CFLAGS/LDFLAGS

Set explicit soft-float for tuple.

Signed-off-by: Donald Hoskins <[email protected]>

Neither the SOLID filesystem API nor built-in filesystems guarantee
thread safety by default. Although this may suffice in general embedded-
system use cases, and in fact the API can be used from multiple threads
without any problems in many cases, this has been a source of
unsoundness in `std::sys::solid::fs`.

This commit updates the `std` code to leverage the filesystem thread-
safety wrapper to enforce thread safety. This is done by prefixing all
paths passed to the filesystem API with `\TS`. (Note that relative paths
aren't supported in this platform.)

Co-authored-by: Urgau <[email protected]>
Co-authored-by: Marcelina Kościelnicka <[email protected]>

Adds support for the LLVM MemTagSanitizer.

Address rust-lang#85991

Suggest the `impl Trait` return type syntax if the user tried to return a generic parameter and we get a type mismatch

The suggestion is not emitted if the param appears in the function parameters, and only get the bounds that actually involve `T: ` directly

It also checks whether the generic param is contained in any where bound (where it isn't the self type), and if one is found (like `Option<T>: Send`), it is not suggested.

This also adds `TyS::contains`, which recursively vistits the type and looks if the other type is contained anywhere

Previously these were entirely disallowed, except for r11 which was
allowed by accident.

…, r=jackh726

Suggest `impl Trait` return type when incorrectly using a generic return type

Address rust-lang#85991

When there is a type mismatch error and the return type is generic, and that generic parameter is not used in the function parameters, suggest replacing that generic with the `impl Trait` syntax.

r? `@estebank`

Add MemTagSanitizer Support

Add support for the LLVM [MemTagSanitizer](https://llvm.org/docs/MemTagSanitizer.html).

On hardware which supports it (see caveats below), the MemTagSanitizer can catch bugs similar to AddressSanitizer and HardwareAddressSanitizer, but with lower overhead.

On a tag mismatch, a SIGSEGV is signaled with code SEGV_MTESERR / SEGV_MTEAERR.

# Usage

`-Zsanitizer=memtag -C target-feature="+mte"`

# Comments/Caveats

* MemTagSanitizer is only supported on AArch64 targets with hardware support
* Requires `-C target-feature="+mte"`
* LLVM MemTagSanitizer currently only performs stack tagging.

# TODO

* Tests
* Example

…eny, r=estebank

Add more information to `impl Trait` error

Fixes rust-lang#92458

Let me know if I went overboard here, or if the suggestions could use some refinement.

r? `@estebank`
Feel free to reassign to someone else

…=GuillaumeGomez

Pass `--test` flag through rustdoc to rustc so `#[test]` functions can be scraped

As a part of stabilizing the scrape examples extension in Cargo, I uncovered a bug where examples cannot be scraped from tests. See this test: https://github.com/rust-lang/cargo/pull/10343/files#diff-27aa4f012ebfebaaee61498d91d2370de460628405d136b05e77efe61e044679R2496

The issue is that when rustdoc is run on a test file, because `--test` is not passed as a rustc option, then functions annotated with `#[test]` are ignored by the compiler. So this PR changes rustdoc so when `--test` is passed in conjunction with a `--scrape-example-<suffix>` flag, then the `test` field of `rustc_interface::Config` is true.

r? `@camelid`

mips64-openwrt-linux-musl: correct soft-foat

MIPS64 targets under OpenWrt require soft-float fpu support.

Rust-lang requires soft-float defined in tuple definition and
isn't over-ridden by toolchain compile-time CFLAGS/LDFLAGS

Set explicit soft-float for tuple.

Signed-off-by: Donald Hoskins <[email protected]>

kmc-solid: Use the filesystem thread-safety wrapper

Fixes the thread unsafety of the `std::fs` implementation used by the [`*-kmc-solid_*`](https://doc.rust-lang.org/nightly/rustc/platform-support/kmc-solid.html) Tier 3 targets.

Neither the SOLID filesystem API nor built-in filesystem drivers guarantee thread safety by default. Although this may suffice in general embedded-system use cases, and in fact the API can be used from multiple threads without any problems in many cases, this has been a source of unsoundness in `std::sys::solid::fs`.

This commit updates the implementation to leverage the filesystem thread-safety wrapper (which uses a pluggable synchronization mechanism) to enforce thread safety. This is done by prefixing all paths passed to the filesystem API with `\TS`. (Note that relative paths aren't supported in this platform.)

asm: Allow the use of r8-r14 as clobbers on Thumb1

Previously these were entirely disallowed, except for r11 which was allowed by accident.

cc `@hudson-ayers`

…h726,nikomatsakis

Only mark projection as ambiguous if GAT substs are constrained

A slightly more targeted version of rust-lang#92917, where we only give up with ambiguity if we infer something about the GATs substs when probing for a projection candidate.

fixes rust-lang#93874
also note (but like the previous PR, does not fix) rust-lang#91762

r? `@jackh726`
cc `@nikomatsakis` who reviewed rust-lang#92917

Implement --check-cfg option (RFC 3013), take 2

This pull-request implement RFC 3013: Checking conditional compilation at compile time (rust-lang/rfcs#3013) and is based on the previous attempt rust-lang#89346 by `@mwkmwkmwk` that was closed due to inactivity.

I have address all the review comments from the previous attempt and added some more tests.

cc rust-lang#82450
r? `@petrochenkov`

Add the `known-bug` test directive, use it, and do some cleanup

cc rust-lang/compiler-team#476

Now tests can be annotated with `known-bug`, which should indicate that the test *should* pass (or at least that the current output is a bug). Adding it relaxes the requirement to add error annotations to the test (though it is still allowed). In the future, this could be extended with further relaxations - with the goal to make adding these tests need minimal effort.

I've used this attribute for the GAT tests added in rust-lang#93757.

Finally, I've also cleaned up `header.rs` in compiletest a bit, by extracting out a bit of common logic. I've also split out some of the directives into their own consts. This removes a lot of very similar functions from `Config` and makes `TestProps::load_from` read nicer.

I've split these into separate commits, so I in theory could split these into separate PRs if they're controversial, but I think they're pretty straightforward.

r? ``@Mark-Simulacrum``