[all-commits] [llvm/llvm-project] b5ef13: [gcov] Increment counters with atomicrmw if -fsani...

[Fangrui Song via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: b5ef137c11b1cc6ae839ee75b49233825772bdd0
      https://github.com/llvm/llvm-project/commit/b5ef137c11b1cc6ae839ee75b49233825772bdd0
  Author: Fangrui Song <maskray at google.com>
  Date:   2020-08-28 (Fri, 28 Aug 2020)

  Changed paths:
    M clang/lib/CodeGen/BackendUtil.cpp
    A clang/test/CodeGen/code-coverage-tsan.c
    M llvm/include/llvm/Transforms/Instrumentation.h
    M llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
    A llvm/test/Transforms/GCOVProfiling/atomic-counter.ll

  Log Message:
  -----------
  [gcov] Increment counters with atomicrmw if -fsanitize=thread

Without this patch, `clang --coverage -fsanitize=thread` may fail spuriously
because non-atomic counter increments can be detected as data races.