1 files changed, 55 insertions, 10 deletions

diff --git a/libcxx/utils/google-benchmark/src/log.h b/libcxx/utils/google-benchmark/src/log.h
index 3777810e1c9..978cb0b4c8c 100644
--- a/libcxx/utils/google-benchmark/src/log.h
+++ b/libcxx/utils/google-benchmark/src/log.h
@@ -1,28 +1,73 @@
 #ifndef BENCHMARK_LOG_H_
 #define BENCHMARK_LOG_H_
 
+#include <iostream>
 #include <ostream>
 
+#include "benchmark/macros.h"
+
 namespace benchmark {
 namespace internal {
 
-int GetLogLevel();
-void SetLogLevel(int level);
+typedef std::basic_ostream<char>&(EndLType)(std::basic_ostream<char>&);
+
+class LogType {
+  friend LogType& GetNullLogInstance();
+  friend LogType& GetErrorLogInstance();
+
+  // FIXME: Add locking to output.
+  template <class Tp>
+  friend LogType& operator<<(LogType&, Tp const&);
+  friend LogType& operator<<(LogType&, EndLType*);
+
+ private:
+  LogType(std::ostream* out) : out_(out) {}
+  std::ostream* out_;
+  BENCHMARK_DISALLOW_COPY_AND_ASSIGN(LogType);
+};
 
-std::ostream& GetNullLogInstance();
-std::ostream& GetErrorLogInstance();
+template <class Tp>
+LogType& operator<<(LogType& log, Tp const& value) {
+  if (log.out_) {
+    *log.out_ << value;
+  }
+  return log;
+}
+
+inline LogType& operator<<(LogType& log, EndLType* m) {
+  if (log.out_) {
+    *log.out_ << m;
+  }
+  return log;
+}
+
+inline int& LogLevel() {
+  static int log_level = 0;
+  return log_level;
+}
+
+inline LogType& GetNullLogInstance() {
+  static LogType log(nullptr);
+  return log;
+}
+
+inline LogType& GetErrorLogInstance() {
+  static LogType log(&std::clog);
+  return log;
+}
 
-inline std::ostream& GetLogInstanceForLevel(int level) {
-  if (level <= GetLogLevel()) {
+inline LogType& GetLogInstanceForLevel(int level) {
+  if (level <= LogLevel()) {
     return GetErrorLogInstance();
   }
   return GetNullLogInstance();
 }
 
-} // end namespace internal
-} // end namespace benchmark
+}  // end namespace internal
+}  // end namespace benchmark
 
-#define VLOG(x) (::benchmark::internal::GetLogInstanceForLevel(x) \
-                 << "-- LOG(" << x << "): ")
+#define VLOG(x)                                                               \
+  (::benchmark::internal::GetLogInstanceForLevel(x) << "-- LOG(" << x << "):" \
+                                                                         " ")
 
 #endif
\ No newline at end of file