[libc++] Disable automatic module scanning on ARM CI builders
The ARM Buildkite toolchains do not expose clang-scan-deps to CMake.
When CMP0155 enables automatic scanning for libc++abi C++23 sources,
these standalone runtimes builds fail with the scanner set to NOTFOUND.
Pass CMAKE_CXX_SCAN_FOR_MODULES=OFF in the eight ARM job invocations,
including the no-exceptions variants, until their toolchains provide a
matching scanner. Keep the other CI configurations on their defaults.
Validated bash syntax, git diff --check, and argument dispatch for all
eight ARM jobs with generic C++20, C++23, and modules jobs as controls.
Assisted-by: Codex
[libc++] Provision a suitable CMake for CI builds
The previous commit raised cmake_minimum_required to 3.31. The GitHub
jobs already satisfy it (the Linux image pins 3.31.0, macOS uses brew,
Windows uses the hosted image), but some self-hosted Buildkite agents
ship an older CMake and their images cannot be updated by us.
Teach run-buildbot to check the CMake version up front. When the cmake
on PATH is new enough, this costs a single `cmake --version` and nothing
else changes. Otherwise, download a pinned, SHA-256 verified CMake
3.31.12 release binary into ${XDG_CACHE_HOME:-~/.cache}/libcxx (outside
the build directory that run-buildbot wipes) and, when no binary exists
for the host or it cannot run there, bootstrap it from source with the
host compilers rather than the runtime's CC/CXX. The install is
published with an atomic rename so concurrent builders on one agent
never see a partial cache entry.
An explicit CMAKE override is still honored but now validated; in the
provisioned or overridden cases its directory is prepended to PATH so
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[libc++abi] Retain the old CMP0155 behavior for GCC compatibility
Raising the minimum CMake version to 3.31 enables automatic module dependency
scanning for the C++23 libc++abi object libraries. GCC 16 and 17 then probe
the libstdc++ bits/stdc++.h header when processing libc++ headers and fail
if it is absent.
Set CMP0155 to OLD within libc++abi only when using GCC until its optional
header lookup is fixed. Preserve automatic scanning with Clang and guard
the policy setting for older CMake versions.
GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127940
Validated the policy workaround on the CMake 3.31 minimum-version branch
with GCC 16.2.0 and CMake 3.31.12: the focused cxa_handlers.cpp reproducer
compiles. Clang 22.1.0 still generates and successfully executes the
clang-scan-deps rule for that source. git diff --check passes.
Assisted-by: Codex
build: Support got
Add code for using got(1), matching how git(1) is currently used:
1. Determining the git branch,
2. Determining the checked-out hash,
3. Determining the commit count,
4. Determining the timestamp of the most recent commit,
5. Determining if the tree is "dirty",
6. Generating lists of files for the src and src-sys packages, and
7. Excluding .got directories from src.txz and ports.txz.
The release engineer hopes to use this functionality in release builds,
since got's minimalism makes it a far more manageable build tool than
git.
Reviewed by: naddy
MFC after: 1 week
Sponsored by: Amazon
Differential Revision: https://reviews.freebsd.org/D60606
[NVPTX] Set default value of nvptx-allow-ftz-atomics to false
This restores the strict FTZ default originally introduced in #200732
and temporarily relaxed in #206154.
Frontends can now explicitly opt in to native FTZ-mismatched atomics on a
per-instruction basis using !atomic.ignore.denormal.mode metadata (#217585,
#217586), which is supported in Clang, MLIR, and XLA. Users who need the
previous behavior globally can still pass -nvptx-allow-ftz-atomics=true.
Update test cases to verify the new default disallow behavior.
[SLP]Do not seed on vectorizer-created compares
With revec, alternate compares are emitted as pairs of compares on
the same operands, which were re-seeded and hanged the compiler.
Reviewers:
Pull Request: https://github.com/llvm/llvm-project/pull/233101
github: Only run the checklist checker for PRs against main
Currently this check is run on every push to stable branches which all
fail since they fail to fetch the non-existent .github/path-rules.txt
from the just-updated branches.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D60709
[Mips] Select RINT instructions for scalar rint on R6 (#233042)
Legalize FRINT and STRICT_FRINT for supported scalar floating-point
types on standard-encoding MIPS R6 targets, and match both operations to
the existing RINT_S and RINT_D instructions instead of libcalls.
Preserve strict FP exception semantics using the existing instruction
properties.
