Add Chrono.h - std::chrono support header

Summary:
std::chrono mostly covers the functionality of llvm::sys::TimeValue and
lldb_private::TimeValue. This header adds a bit of utility functions and
typedefs, which make the usage of the library and porting code from TimeValues
easier.

Rationale:
- TimePoint typedef - precision of system_clock is implementation defined -
  using a well-defined precision helps maintain consistency between platforms,
  makes it interact better with existing TimeValue classes, and avoids cases
  there a time point is implicitly convertible to a specific precision on some
  platforms but not on others.
- system_clock::to_time_t only accepts time_points with the default system
  precision (even though time_t has only second precision on all platforms we
  support). To avoid the need for explicit casts, I have added a toTimeT()
  wrapper function. toTimePoint(time_t) was not strictly necessary, but I have
  added it for symmetry.

Reviewers: zturner, mehdi_amini

Subscribers: beanz, mgorny, llvm-commits, modocache

Differential Revision: https://reviews.llvm.org/D25416

llvm-svn: 284590

1 files changed, 0 insertions, 61 deletions

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;
-}