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llvm / llvm-project / eac7466448f920e733f12beca28ff848cfa4810d
commiteac7466448f920e733f12beca28ff848cfa4810d[log] [tgz]
authorAlexey Karyakin <akaryaki@quicinc.com>Wed May 14 10:33:57 2025 -0500
committerGitHub <noreply@github.com>Wed May 14 10:33:57 2025 -0500
tree6dfdc9d6ae7f09c5116878d2fb50888f67337ce0
parentee47454bb8be7f4cd1ecbd862c5a82d24ef696c7 [diff]
[LTO] Fix a crash with thin LTO caching and asm output (#138203)

The `CacheStream::commit()` function (defined in Caching.cpp) deletes
the underlying raw stream. Some output streamers may hold a pointer
to it, which then will outlive the stream object.
In particular, MCAsmStreamer keeps the pointer to the raw stream
though a separate `formatted_raw_stream` object, which buffers data and
there is no path to explicitly flush this data. Before this change,
the buffered data was flushed during the MCAsmStreamer destructor.
After #136121, this happened after the `commit()` function is called.
Therefore, it caused a crash because the `formatted_raw_stream` object
tries to write the buffered data into a deleted raw stream. Even if
we don't delete the stream to avoid the crash, it would be too late
as the output stream cannot accept data after commit().

Fixes: #138194.
2 files changed
tree: 6dfdc9d6ae7f09c5116878d2fb50888f67337ce0
  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-format-ignore
  30. .clang-tidy
  31. .git-blame-ignore-revs
  32. .gitattributes
  33. .gitignore
  34. .mailmap
  35. CODE_OF_CONDUCT.md
  36. CONTRIBUTING.md
  37. LICENSE.TXT
  38. pyproject.toml
  39. README.md
  40. SECURITY.md
README.md

The LLVM Compiler Infrastructure

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Welcome to the LLVM project!

This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.

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