1 // Copyright 2018 The Chromium Authors 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "base/test/clang_profiling.h" 6 7 #include "base/no_destructor.h" 8 #include "base/synchronization/lock.h" 9 #include "build/build_config.h" 10 11 extern "C" int __llvm_profile_dump(void); 12 13 namespace base { 14 WriteClangProfilingProfile()15void WriteClangProfilingProfile() { 16 // __llvm_profile_dump() guarantees that it will not dump profiling 17 // information if it is being called twice or more. However, it is not thread 18 // safe, as it is supposed to be called from atexit() handler rather than 19 // being called directly from random places. Since we have to call it 20 // ourselves, we must ensure thread safety in order to prevent duplication of 21 // profiling counters. 22 static base::NoDestructor<base::Lock> lock; 23 base::AutoLock auto_lock(*lock); 24 25 // Fuchsia's profile runtime does not handle profile dumping. 26 // Coverage builds are built with runtime counter relocation and are expected to 27 // be run under continuous coverage mode (enabled by adding %c to the 28 // LLVM_PROFILE_FILE environment variable), which updates counters in real time, 29 // so __llvm_profile_dump() is not needed. 30 #if !BUILDFLAG(IS_FUCHSIA) && !BUILDFLAG(USE_CLANG_COVERAGE) 31 __llvm_profile_dump(); 32 #endif // !BUILDFLAG(IS_FUCHSIA) && !BUILDFLAG(USE_CLANG_COVERAGE) 33 } 34 35 } // namespace base 36