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llvm / llvm-project / 677e8cd6ff51e178bcb4669104763f71a2de106c
commit677e8cd6ff51e178bcb4669104763f71a2de106c[log] [tgz]
authorLouis Dionne <ldionne.2@gmail.com>Tue Oct 01 09:39:44 2024 -0400
committerGitHub <noreply@github.com>Tue Oct 01 09:39:44 2024 -0400
tree6a53335450c8242bd559d5e9b9aa882931b61b50
parentbb78a0b33496fb0140cec1a92a689505f53253b7 [diff]
[libc++] Avoid re-exporting a few specific symbols from libc++abi (#109054)

In 6a884a9aef39, I synchronized the export list of libc++abi to the
export list of libc++. From the linker's perspective, this caused these
symbols to be taken from libc++.dylib instead of libc++abi.dylib.

However, that can be problematic when back-deploying. Indeed, this means
that the linker will encode an undefined reference to be fullfilled by
libc++.dylib, but when backdeploying against an older system, that
symbol might only be available in libc++abi.dylib.

Most of the symbols that started being re-exported after 6a884a9aef39
turn out to be implementation details of libc++abi, so nobody really
depends on them and this back-deployment issue is inconsequential.

However, we ran into issues with a few of these symbols while testing
LLVM 19, which led to this patch. This slipped between the cracks and
that is why the patch is coming so long after the original patch landed.

In the future, a follow-up cleanup would be to stop exporting most of
the _cxxabiv1_foo_type_infoE symbols from both libc++abi and libc++
since they are implementation details that nobody should be relying on.

rdar://131984512
7 files changed
tree: 6a53335450c8242bd559d5e9b9aa882931b61b50
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. libc/
  11. libclc/
  12. libcxx/
  13. libcxxabi/
  14. libunwind/
  15. lld/
  16. lldb/
  17. llvm/
  18. llvm-libgcc/
  19. mlir/
  20. offload/
  21. openmp/
  22. polly/
  23. pstl/
  24. runtimes/
  25. third-party/
  26. utils/
  27. .clang-format
  28. .clang-tidy
  29. .git-blame-ignore-revs
  30. .gitattributes
  31. .gitignore
  32. .mailmap
  33. CODE_OF_CONDUCT.md
  34. CONTRIBUTING.md
  35. LICENSE.TXT
  36. pyproject.toml
  37. README.md
  38. SECURITY.md
README.md

The LLVM Compiler Infrastructure

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