[all-commits] [llvm/llvm-project] 5ed8a1: [Bazel] Give musl LLVM tools 8 MiB worker stacks (...

[David Zbarsky via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5ed8a18c43ad9d328df1cfa08e3377933e6ea398
      https://github.com/llvm/llvm-project/commit/5ed8a18c43ad9d328df1cfa08e3377933e6ea398
  Author: David Zbarsky <dzbarsky at gmail.com>
  Date:   2026-09-21 (Mon, 21 Sep 2026)

  Changed paths:
    M utils/bazel/llvm-project-overlay/llvm/BUILD.bazel

  Log Message:
  -----------
  [Bazel] Give musl LLVM tools 8 MiB worker stacks (#223989)

LLVM 23 ThinLTO can overflow musl's 128 KiB default pthread stack in
`DSEState::eliminateRedundantStoresViaDominatingConditions`, crashing
`ld.lld` on valid input. Add `-Wl,-z,stack-size=8388608` to
`Support.linkopts` for musl Bazel builds, using the
`@rules_cc//cc/libc:musl` constraint already used by `config.bzl`. [musl
supports increasing default pthread stacks through
`PT_GNU_STACK`](https://wiki.musl-libc.org/functional-differences-from-glibc.html).

Downstream validation on LLVM 23.1.0 in
https://github.com/hermeticbuild/hermetic-llvm/pull/753 reproduced the
crash with a captured link and a synthetic 1000-block ThinLTO input. A
musl linker rebuilt with the same linker option advertised an 8 MiB
`GNU_STACK` and passed both cases.

On this upstream branch, Buildifier, `git diff --check`, and
`llvm-check-pr-format` pass (no changed C/C++ files). No fresh
upstream-main LLVM build was performed.

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