Update to LLVM 15
For preliminary testing. Some LLVM 15 compatibility fixes were applied separately in #99512.
Release timeline:
* LLVM 15 branched on Jul 26.
* The final LLVM 15.0.0 release is scheduled for Sep 6.
* Current nightly (1.65.0) is scheduled for Nov 3.
Changes in this PR (apart from the LLVM update):
* Pass `--set llvm.allow-old-toolchain` for many Docker images. LLVM 16 will require GCC >= 7.1, while LLVM 15 still allows older compilers with an option. Specify the option for builders still using GCC 5.4. #95026 updated some of the used toolchains, but not all.
* Use the `+atomics-32` target feature for thumbv6m.
* Explicitly link libatomic when cross-compiling LLVM to 32-bit target.
* Explicitly disable zstd support, to avoid libzstd.so dependency.
New LLVM patches ([commits](https://github.com/rust-lang/llvm-project/commits/rustc/15.0-2022-08-09)):
* [rust-only] Fix ICE with GCC 5.4 (15be58d7f0)
* [rust-only] Fix build with GCC 5.4 (774edc10fa)
* ~~[rust-only] Fix build with GCC 5.2 (1a6069a7bb)~~
* ~~[rust-only] Fix ICE with GCC 5.2 (493081f290)~~
* ~~[rust-only] Fix build with GCC 5.2 (0fc5979d73)~~
* [backported] Addition of `+atomics` target feature (57bdd9892d).
* [backported] Revert compiler-rt change that broke powerpc (9c68b43915)
* [awaiting backport] Fix RelLookupTableConverter on gnux32 (639388a05f / https://github.com/llvm/llvm-project/issues/57021)
Tested images: dist-x86_64-linux, armhf-gnu, arm-android, dist-s390x-linux, dist-x86_64-illumos, dist-x86_64-freebsd, wasm32, dist-x86_64-musl, dist-various-1, dist-riscv64-linux, dist-mips-linux, dist-mipsel-linux, dist-powerpc-linux, dist-aarch64-linux, dist-x86_64-apple, x86_64-msvc-1, x86_64-msvc-2, dist-various-2, dist-arm-linux
Tested up to the usual ipv6 error: test-various, i686-gnu, x86_64-gnu-nopt
r? `@ghost`
Stringify non-shorthand visibility correctly
This makes `stringify!(pub(in crate))` evaluate to `pub(in crate)` rather than `pub(crate)`, matching the behavior before the `crate` shorthand was removed. Further, this changes `stringify!(pub(in super))` to evaluate to `pub(in super)` rather than the current `pub(super)`. If the latter is not desired (it is _technically_ breaking), it can be undone.
Fixes#99981
`@rustbot` label +C-bug +regression-from-stable-to-beta +T-compiler
Add `x.sh` and `x.ps1` shell scripts
This is a more ambitious version of https://github.com/rust-lang/rust/pull/98716.
It still changes the x.py shebang back to python3, for compatibility with non-Unix systems,
but also adds alternative entrypoints for systems without `python3` installed.
These scripts will be necessary for the rust entrypoint (#94829), so I see
little downside in adding them early.
I'll update the dev-guide to suggest using these instead of x.py once this is merged.
Fixes https://github.com/rust-lang/rust/issues/98650
r? `@Mark-Simulacrum` cc `@dtolnay` `@CAD97` `@yoshuawuyts`
make raw_eq precondition more restrictive
Specifically, don't allow comparing pointers that way. Comparing pointers is subtle because you have to talk about what happens to the provenance.
This matches what [Miri already implements](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=9eb1dfb8a61b5a2d4a7cee43df2717af), and all existing users are fine with this.
If raw_eq on pointers is ever desired, we can adjust the intrinsic spec and Miri implementation as needed, but for now that seems just unnecessary. Also, this is a const intrinsic, and in const, comparing pointers this way is *not possible* -- so if we allow the intrinsic to compare pointers in general, we need to impose an extra restrictions saying that in const-context, pointers are *not* okay.
Fix flags when using clang as linker for Fuchsia
Don't add C runtime or set dynamic linker when linking with clang for
Fuchsia. Clang already does this for us.
rustdoc: simplify highlight.rs
Split render_with_highlighting, which took many optional parameters, into three functions for specific purposes, which each take a smaller number of mostly required parameters.
Remove some plumbing to pass through an "edition" parameter, which was used solely to avoid highlighting some 2021 Edition keywords in non-2021 code.
I've tested a build of std docs before and after, and this does not change the generated HTML at all.
Followup from https://github.com/rust-lang/rust/pull/91264#discussion_r901151101
r? ```@GuillaumeGomez```
Improve error messages when running rustdoc GUI tests
There was already a message on how to install `browser-ui-test`, so nothing to be done there. However, we didn't show how to update its version, so the first commit adds it.
Another pain point was how to fix the unexpected crash in `browser-ui-test` (because of a missing `--no-sandbox`, still no idea why it became mandatory a few months ago on some linux distributions...). It now looks like this:
```console
Running 1 rustdoc-gui (8 concurrently) ...
ERROR: puppeteer failed when trying to create a new page. Please try again with `--no-sandbox`
`browser-ui-test` crashed unexpectedly. Please try again with adding `--test-args --no-sandbox` at the end. For example: `x.py test src/test/rustdoc-gui --test-args --no-sandbox`
Build completed unsuccessfully in 0:00:03
```
Thanks to `@jsha` for suggesting these improvements!
r? `@jsha`
Use `&mut Diagnostic` instead of `&mut DiagnosticBuilder` unless needed
This seems to be the established convention (02ff9e0) when `DiagnosticBuilder` was first added. I am guilty of introducing some of these.
linux: Use `pthread_setname_np` instead of `prctl`
This function is available on Linux since glibc 2.12, musl 1.1.16, and
uClibc 1.0.20. The main advantage over `prctl` is that it properly
represents the pointer argument, rather than a multi-purpose `long`,
so we're better representing strict provenance (#95496).
Remove duplicated temporaries creating during box derefs elaboration
Temporaries created with `MirPatch::new_temp` will be declared after
patch application. Remove manually created duplicate declarations.
Removing duplicates exposes another issue. Visitor elaborates
terminator twice and attempts to access new, but not yet available,
local declarations. Remove duplicated call to `visit_terminator`.
Extracted from #99946.
Determine match_has_guard from candidates instead of looking up thir table again
Currently looking through mir build of matches because of interest in deref patterns. Finding some micro-optimizable things.
Check if enum from foreign crate has any non exhaustive variants when attempting a cast
Fixes#91161
As stated in the issue, this will require a crater run as it might break other people's stuff.
