Reapply "Add Chrono.h - std::chrono support header"

This is a resubmission of r284590. The mingw build should be fixed now. The
problem was we were matching time_t with _localtime_64s, which was incorrect on
_USE_32BIT_TIME_T systems. Instead I use localtime_s, which should always
evaluate to the correct function.

llvm-svn: 284720

1 files changed, 47 insertions, 0 deletions

diff --git a/llvm/lib/Support/Chrono.cpp b/llvm/lib/Support/Chrono.cpp
new file mode 100644
index 0000000..cdadbd8
--- /dev/null
+++ b/llvm/lib/Support/Chrono.cpp
@@ -0,0 +1,47 @@
+//===- Support/Chrono.cpp - Utilities for Timing Manipulation ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/Chrono.h"
+#include "llvm/Config/config.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+
+using namespace sys;
+
+static inline struct tm getStructTM(TimePoint<> TP) {
+  struct tm Storage;
+  std::time_t OurTime = toTimeT(TP);
+
+#if defined(LLVM_ON_UNIX)
+  struct tm *LT = ::localtime_r(&OurTime, &Storage);
+  assert(LT);
+  (void)LT;
+#endif
+#if defined(LLVM_ON_WIN32)
+  int Error = ::localtime_s(&Storage, &OurTime);
+  assert(!Error);
+  (void)Error;
+#endif
+
+  return Storage;
+}
+
+raw_ostream &operator<<(raw_ostream &OS, TimePoint<> TP) {
+  struct tm LT = getStructTM(TP);
+  char Buffer[sizeof("YYYY-MM-DD HH:MM:SS")];
+  strftime(Buffer, sizeof(Buffer), "%Y-%m-%d %H:%M:%S", &LT);
+  return OS << Buffer << '.'
+            << format("%.9lu",
+                      long((TP.time_since_epoch() % std::chrono::seconds(1))
+                               .count()));
+}
+
+} // namespace llvm