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llvm / llvm-project / 1f90a88b80998e595a3a11a7d13c333dbfa8777a
commit1f90a88b80998e595a3a11a7d13c333dbfa8777a[log] [tgz]
authorDavid Spickett <david.spickett@linaro.org>Fri Mar 28 14:30:38 2025 +0000
committerGitHub <noreply@github.com>Fri Mar 28 14:30:38 2025 +0000
tree14c804bd4501a1a7c4bfc4aeb3a12b5c4cd13e1a
parent48b753027382a5815295d6680c7dd407be936c86 [diff]
[libcxx] Remove clang-18 workaround in picolib build (#133254)

clang-19 changed how Arm triples were normalised and so while we
supported 18 and 19, we could not hard code the path here.

Now that Linaro's bots are running clang-19, and libcxx is going to drop
clang-18 support (https://github.com/llvm/llvm-project/pull/130142) I
have simplified it by hard coding the path again.

I also looked into why this exists in the first place. It was added in
https://reviews.llvm.org/D154246 but not questioned at the time.

It is due to the way we build compiler-rt, which is due to the final
layout we need in the install:
1. The builtins library must be called libclang_rt.builtins.a for clang
to find it. There must not be an architecture name in the filename.
2. That builtins library must be directly in lib/, next to picolib's
installed files.

To achieve number 1 we must set LLVM_ENABLE_PER_TARGET_RUNTIME_DIR=ON.
However, that causes the file to be installed in a per-target dir which
breaks number 2. So to fix that, we move the builtins library up one
level into lib/.

The alternative is to turn off per-target dirs, which results in a
builtin file with an arch in the name, then rename and move that file
(since it gets installed into lib/generic/).

So in the end, it's the same amount of hacks. I think it's best to keep
the one that uses LLVM_ENABLE_PER_TARGET_RUNTIME_DIR=ON, as this is the
recommended way to built these days.
1 file changed
tree: 14c804bd4501a1a7c4bfc4aeb3a12b5c4cd13e1a
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. flang-rt/
  11. libc/
  12. libclc/
  13. libcxx/
  14. libcxxabi/
  15. libunwind/
  16. lld/
  17. lldb/
  18. llvm/
  19. llvm-libgcc/
  20. mlir/
  21. offload/
  22. openmp/
  23. polly/
  24. pstl/
  25. runtimes/
  26. third-party/
  27. utils/
  28. .clang-format
  29. .clang-tidy
  30. .git-blame-ignore-revs
  31. .gitattributes
  32. .gitignore
  33. .mailmap
  34. CODE_OF_CONDUCT.md
  35. CONTRIBUTING.md
  36. LICENSE.TXT
  37. pyproject.toml
  38. README.md
  39. SECURITY.md
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