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

5 files changed, 56 insertions, 124 deletions

diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
index cf04016da2d..d8ecfa9b862 100644
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -37,6 +37,7 @@ add_llvm_library(LLVMSupport
   BranchProbability.cpp
   CachePruning.cpp
   circular_raw_ostream.cpp
+  Chrono.cpp
   COM.cpp
   CommandLine.cpp
   Compression.cpp
diff --git a/llvm/lib/Support/Chrono.cpp b/llvm/lib/Support/Chrono.cpp
new file mode 100644
index 00000000000..cdadbd87997
--- /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
diff --git a/llvm/lib/Support/TimeValue.cpp b/llvm/lib/Support/TimeValue.cpp
index 94a4c011693..18c84ca9fa0 100644
--- a/llvm/lib/Support/TimeValue.cpp
+++ b/llvm/lib/Support/TimeValue.cpp
@@ -12,7 +12,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/TimeValue.h"
-#include "llvm/Config/config.h"
+#include "llvm/Support/Chrono.h"
+#include "llvm/Support/ScopedPrinter.h"
 
 namespace llvm {
 
@@ -45,12 +46,10 @@ void TimeValue::normalize() {
   }
 }
 
-} // namespace llvm
+std::string TimeValue::str() const { return to_string(TimePoint<>(*this)); }
+
+TimeValue TimeValue::now() {
+  return TimePoint<>(std::chrono::system_clock::now());
+}
 
-/// Include the platform-specific portion of TimeValue class
-#ifdef LLVM_ON_UNIX
-#include "Unix/TimeValue.inc"
-#endif
-#ifdef LLVM_ON_WIN32
-#include "Windows/TimeValue.inc"
-#endif
+} // namespace llvm
diff --git a/llvm/lib/Support/Unix/TimeValue.inc b/llvm/lib/Support/Unix/TimeValue.inc
deleted file mode 100644
index 042e0dacc34..00000000000
--- a/llvm/lib/Support/Unix/TimeValue.inc
+++ /dev/null
@@ -1,54 +0,0 @@
-//===- Unix/TimeValue.cpp - Unix TimeValue Implementation -------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the Unix specific portion of the TimeValue class.
-//
-//===----------------------------------------------------------------------===//
-
-//===----------------------------------------------------------------------===//
-//=== WARNING: Implementation here must contain only generic UNIX code that
-//===          is guaranteed to work on *all* UNIX variants.
-//===----------------------------------------------------------------------===//
-
-#include "Unix.h"
-
-namespace llvm {
-  using namespace sys;
-
-std::string TimeValue::str() const {
-  time_t OurTime = time_t(this->toEpochTime());
-  struct tm Storage;
-  struct tm *LT = ::localtime_r(&OurTime, &Storage);
-  assert(LT);
-  char Buffer1[sizeof("YYYY-MM-DD HH:MM:SS")];
-  strftime(Buffer1, sizeof(Buffer1), "%Y-%m-%d %H:%M:%S", LT);
-  char Buffer2[sizeof("YYYY-MM-DD HH:MM:SS.MMMUUUNNN")];
-  snprintf(Buffer2, sizeof(Buffer2), "%s.%.9u", Buffer1, this->nanoseconds());
-  return std::string(Buffer2);
-}
-
-TimeValue TimeValue::now() {
-  struct timeval the_time;
-  timerclear(&the_time);
-  if (0 != ::gettimeofday(&the_time,nullptr)) {
-    // This is *really* unlikely to occur because the only gettimeofday
-    // errors concern the timezone parameter which we're passing in as 0.
-    // In the unlikely case it does happen, just return MinTime, no error
-    // message needed.
-    return MinTime();
-  }
-
-  return TimeValue(
-    static_cast<TimeValue::SecondsType>( the_time.tv_sec +
-      PosixZeroTimeSeconds ),
-    static_cast<TimeValue::NanoSecondsType>( the_time.tv_usec *
-      NANOSECONDS_PER_MICROSECOND ) );
-}
-
-}
diff --git a/llvm/lib/Support/Windows/TimeValue.inc b/llvm/lib/Support/Windows/TimeValue.inc
deleted file mode 100644
index b90b4f1da00..00000000000
--- a/llvm/lib/Support/Windows/TimeValue.inc
+++ /dev/null
@@ -1,61 +0,0 @@
-//===- Win32/TimeValue.cpp - Win32 TimeValue Implementation -----*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file provides the Win32 implementation of the TimeValue class.
-//
-//===----------------------------------------------------------------------===//
-
-#include "WindowsSupport.h"
-#include "llvm/Support/Format.h"
-#include "llvm/Support/raw_ostream.h"
-#include <cctype>
-#include <time.h>
-
-using namespace llvm;
-using namespace llvm::sys;
-
-//===----------------------------------------------------------------------===//
-//=== WARNING: Implementation here must contain only Win32 specific code.
-//===----------------------------------------------------------------------===//
-
-TimeValue TimeValue::now() {
-  uint64_t ft;
-  GetSystemTimeAsFileTime(reinterpret_cast<FILETIME *>(&ft));
-
-  TimeValue t(0, 0);
-  t.fromWin32Time(ft);
-  return t;
-}
-
-std::string TimeValue::str() const {
-  std::string S;
-  struct tm *LT;
-#ifdef __MINGW32__
-  // Old versions of mingw don't have _localtime64_s. Remove this once we drop support
-  // for them.
-  time_t OurTime = time_t(this->toEpochTime());
-  LT = ::localtime(&OurTime);
-  assert(LT);
-#else
-  struct tm Storage;
-  __time64_t OurTime = this->toEpochTime();
-  int Error = ::_localtime64_s(&Storage, &OurTime);
-  assert(!Error);
-  (void)Error;
-  LT = &Storage;
-#endif
-
-  char Buffer[sizeof("YYYY-MM-DD HH:MM:SS")];
-  strftime(Buffer, sizeof(Buffer), "%Y-%m-%d %H:%M:%S", LT);
-  raw_string_ostream OS(S);
-  OS << format("%s.%.9u", static_cast<const char *>(Buffer),
-               this->nanoseconds());
-  OS.flush();
-  return S;
-}