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base / test / clang_profiling.cc [blame]
// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/test/clang_profiling.h"
#include "base/no_destructor.h"
#include "base/synchronization/lock.h"
#include "build/build_config.h"
extern "C" int __llvm_profile_dump(void);
namespace base {
void WriteClangProfilingProfile() {
// __llvm_profile_dump() guarantees that it will not dump profiling
// information if it is being called twice or more. However, it is not thread
// safe, as it is supposed to be called from atexit() handler rather than
// being called directly from random places. Since we have to call it
// ourselves, we must ensure thread safety in order to prevent duplication of
// profiling counters.
static base::NoDestructor<base::Lock> lock;
base::AutoLock auto_lock(*lock);
// Fuchsia's profile runtime does not handle profile dumping.
// Coverage builds are built with runtime counter relocation and are expected to
// be run under continuous coverage mode (enabled by adding %c to the
// LLVM_PROFILE_FILE environment variable), which updates counters in real time,
// so __llvm_profile_dump() is not needed.
#if !BUILDFLAG(IS_FUCHSIA) && !BUILDFLAG(USE_CLANG_COVERAGE)
__llvm_profile_dump();
#endif // !BUILDFLAG(IS_FUCHSIA) && !BUILDFLAG(USE_CLANG_COVERAGE)
}
} // namespace base