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llvm / llvm-project / 8832a5950f3b62331842ecb2f3a68f33732822eb
commit8832a5950f3b62331842ecb2f3a68f33732822eb[log] [tgz]
authorJan Svoboda <jan_svoboda@apple.com>Thu Apr 24 10:18:45 2025 -0700
committerGitHub <noreply@github.com>Thu Apr 24 10:18:45 2025 -0700
tree3e4326e877e53faf5cf47f058e64f9c8c321b944
parent7a276c8acfc3977de8c3ceb0af67fcf603834946 [diff]
[clang] Enable making the module build stack thread-safe (#137059)

This PR makes another piece of the
`CompilerInstance::cloneForModuleCompile()` result thread-safe: the
module build stack. This data structure is used to detect cyclic
dependencies between modules. The problem is that it uses
`FullSourceLoc` which refers to the `SourceManager` of the parent
`CompilerInstance`: if two threads happen to execute `CompilerInstance`s
cloned from the same parent concurrently, and both discover a dependency
cycle, they may concurrently access the parent `SourceManager` when
emitting the diagnostic, creating a data race.

In this PR, we prevent this by keeping the stack empty and moving the
responsibility of cycle detection to the client. The client can recreate
the same module build stack externally and ensure thread-safety by
enforcing mutual exclusion.
1 file changed
tree: 3e4326e877e53faf5cf47f058e64f9c8c321b944
  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.

The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.

C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.

Other components include: the libc++ C++ standard library, the LLD linker, and more.

Getting the Source Code and Building LLVM

Consult the Getting Started with LLVM page for information on building and running LLVM.

For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.

Getting in touch

Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.

The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.