Update LLVM for rebase to r212749.

Includes a cherry-pick of:
r212948 - fixes a small issue with atomic calls

Change-Id: Ib97bd980b59f18142a69506400911a6009d9df18

7 files changed, 170 insertions, 348 deletions

diff --git a/lib/Support/Windows/DynamicLibrary.inc b/lib/Support/Windows/DynamicLibrary.inc
index 5d0278f..5ed0b70 100644
--- a/lib/Support/Windows/DynamicLibrary.inc
+++ b/lib/Support/Windows/DynamicLibrary.inc
@@ -85,7 +85,7 @@ DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *filename,
   }
 
   SmallVector<wchar_t, MAX_PATH> filenameUnicode;
-  if (error_code ec = windows::UTF8ToUTF16(filename, filenameUnicode)) {
+  if (std::error_code ec = windows::UTF8ToUTF16(filename, filenameUnicode)) {
     SetLastError(ec.value());
     MakeErrMsg(errMsg, std::string(filename) + ": Can't convert to UTF-16: ");
     return DynamicLibrary();
diff --git a/lib/Support/Windows/Memory.inc b/lib/Support/Windows/Memory.inc
index ebe7878..ae8371a 100644
--- a/lib/Support/Windows/Memory.inc
+++ b/lib/Support/Windows/Memory.inc
@@ -15,6 +15,7 @@
 #include "llvm/Support/DataTypes.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Process.h"
+#include "llvm/Support/WindowsError.h"
 
 // The Windows.h header must be the last one included.
 #include "WindowsSupport.h"
@@ -69,8 +70,8 @@ namespace sys {
 MemoryBlock Memory::allocateMappedMemory(size_t NumBytes,
                                          const MemoryBlock *const NearBlock,
                                          unsigned Flags,
-                                         error_code &EC) {
-  EC = error_code::success();
+                                         std::error_code &EC) {
+  EC = std::error_code();
   if (NumBytes == 0)
     return MemoryBlock();
 
@@ -99,7 +100,7 @@ MemoryBlock Memory::allocateMappedMemory(size_t NumBytes,
       // Try again without the NearBlock hint
       return allocateMappedMemory(NumBytes, NULL, Flags, EC);
     }
-    EC = error_code(::GetLastError(), system_category());
+    EC = mapWindowsError(::GetLastError());
     return MemoryBlock();
   }
 
@@ -113,34 +114,34 @@ MemoryBlock Memory::allocateMappedMemory(size_t NumBytes,
   return Result;
 }
 
-error_code Memory::releaseMappedMemory(MemoryBlock &M) {
+  std::error_code Memory::releaseMappedMemory(MemoryBlock &M) {
   if (M.Address == 0 || M.Size == 0)
-    return error_code::success();
+    return std::error_code();
 
   if (!VirtualFree(M.Address, 0, MEM_RELEASE))
-    return error_code(::GetLastError(), system_category());
+    return mapWindowsError(::GetLastError());
 
   M.Address = 0;
   M.Size = 0;
 
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code Memory::protectMappedMemory(const MemoryBlock &M,
+  std::error_code Memory::protectMappedMemory(const MemoryBlock &M,
                                        unsigned Flags) {
   if (M.Address == 0 || M.Size == 0)
-    return error_code::success();
+    return std::error_code();
 
   DWORD Protect = getWindowsProtectionFlags(Flags);
 
   DWORD OldFlags;
   if (!VirtualProtect(M.Address, M.Size, Protect, &OldFlags))
-    return error_code(::GetLastError(), system_category());
+    return mapWindowsError(::GetLastError());
 
   if (Flags & MF_EXEC)
     Memory::InvalidateInstructionCache(M.Address, M.Size);
 
-  return error_code::success();
+  return std::error_code();
 }
 
 /// InvalidateInstructionCache - Before the JIT can run a block of code
@@ -156,18 +157,18 @@ MemoryBlock Memory::AllocateRWX(size_t NumBytes,
                                 const MemoryBlock *NearBlock,
                                 std::string *ErrMsg) {
   MemoryBlock MB;
-  error_code EC;
+  std::error_code EC;
   MB = allocateMappedMemory(NumBytes, NearBlock,
                             MF_READ|MF_WRITE|MF_EXEC, EC);
-  if (EC != error_code::success() && ErrMsg) {
+  if (EC != std::error_code() && ErrMsg) {
     MakeErrMsg(ErrMsg, EC.message());
   }
   return MB;
 }
 
 bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
-  error_code EC = releaseMappedMemory(M);
-  if (EC == error_code::success())
+  std::error_code EC = releaseMappedMemory(M);
+  if (EC == std::error_code())
     return false;
   MakeErrMsg(ErrMsg, EC.message());
   return true;
diff --git a/lib/Support/Windows/Path.inc b/lib/Support/Windows/Path.inc
index e59888e..7a1bc04 100644
--- a/lib/Support/Windows/Path.inc
+++ b/lib/Support/Windows/Path.inc
@@ -17,6 +17,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/WindowsError.h"
 #include <fcntl.h>
 #include <io.h>
 #include <sys/stat.h>
@@ -44,7 +45,11 @@ using namespace llvm;
 using llvm::sys::windows::UTF8ToUTF16;
 using llvm::sys::windows::UTF16ToUTF8;
 
-static error_code TempDir(SmallVectorImpl<char> &Result) {
+static std::error_code windows_error(DWORD E) {
+  return mapWindowsError(E);
+}
+
+static std::error_code TempDir(SmallVectorImpl<char> &Result) {
   SmallVector<wchar_t, 64> Res;
 retry_temp_dir:
   DWORD Len = ::GetTempPathW(Res.capacity(), Res.begin());
@@ -119,7 +124,7 @@ TimeValue file_status::getLastModificationTime() const {
   return Ret;
 }
 
-error_code current_path(SmallVectorImpl<char> &result) {
+std::error_code current_path(SmallVectorImpl<char> &result) {
   SmallVector<wchar_t, MAX_PATH> cur_path;
   DWORD len = MAX_PATH;
 
@@ -141,30 +146,30 @@ error_code current_path(SmallVectorImpl<char> &result) {
   return UTF16ToUTF8(cur_path.begin(), cur_path.size(), result);
 }
 
-error_code create_directory(const Twine &path, bool IgnoreExisting) {
+std::error_code create_directory(const Twine &path, bool IgnoreExisting) {
   SmallString<128> path_storage;
   SmallVector<wchar_t, 128> path_utf16;
 
-  if (error_code ec = UTF8ToUTF16(path.toStringRef(path_storage),
-                                  path_utf16))
+  if (std::error_code ec =
+          UTF8ToUTF16(path.toStringRef(path_storage), path_utf16))
     return ec;
 
   if (!::CreateDirectoryW(path_utf16.begin(), NULL)) {
-    error_code ec = windows_error(::GetLastError());
-    if (ec != windows_error::already_exists || !IgnoreExisting)
-      return ec;
+    DWORD LastError = ::GetLastError();
+    if (LastError != ERROR_ALREADY_EXISTS || !IgnoreExisting)
+      return windows_error(LastError);
   }
 
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code normalize_separators(SmallVectorImpl<char> &Path) {
+std::error_code normalize_separators(SmallVectorImpl<char> &Path) {
   (void) Path;
-  return error_code::success();
+  return std::error_code();
 }
 
 // We can't use symbolic links for windows.
-error_code create_link(const Twine &to, const Twine &from) {
+std::error_code create_link(const Twine &to, const Twine &from) {
   // Get arguments.
   SmallString<128> from_storage;
   SmallString<128> to_storage;
@@ -174,47 +179,49 @@ error_code create_link(const Twine &to, const Twine &from) {
   // Convert to utf-16.
   SmallVector<wchar_t, 128> wide_from;
   SmallVector<wchar_t, 128> wide_to;
-  if (error_code ec = UTF8ToUTF16(f, wide_from)) return ec;
-  if (error_code ec = UTF8ToUTF16(t, wide_to)) return ec;
+  if (std::error_code ec = UTF8ToUTF16(f, wide_from))
+    return ec;
+  if (std::error_code ec = UTF8ToUTF16(t, wide_to))
+    return ec;
 
   if (!::CreateHardLinkW(wide_from.begin(), wide_to.begin(), NULL))
     return windows_error(::GetLastError());
 
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code remove(const Twine &path, bool IgnoreNonExisting) {
+std::error_code remove(const Twine &path, bool IgnoreNonExisting) {
   SmallString<128> path_storage;
   SmallVector<wchar_t, 128> path_utf16;
 
   file_status ST;
-  if (error_code EC = status(path, ST)) {
+  if (std::error_code EC = status(path, ST)) {
     if (EC != errc::no_such_file_or_directory || !IgnoreNonExisting)
       return EC;
-    return error_code::success();
+    return std::error_code();
   }
 
-  if (error_code ec = UTF8ToUTF16(path.toStringRef(path_storage),
-                                  path_utf16))
+  if (std::error_code ec =
+          UTF8ToUTF16(path.toStringRef(path_storage), path_utf16))
     return ec;
 
   if (ST.type() == file_type::directory_file) {
     if (!::RemoveDirectoryW(c_str(path_utf16))) {
-      error_code EC = windows_error(::GetLastError());
+      std::error_code EC = windows_error(::GetLastError());
       if (EC != errc::no_such_file_or_directory || !IgnoreNonExisting)
         return EC;
     }
-    return error_code::success();
+    return std::error_code();
   }
   if (!::DeleteFileW(c_str(path_utf16))) {
-    error_code EC = windows_error(::GetLastError());
+    std::error_code EC = windows_error(::GetLastError());
     if (EC != errc::no_such_file_or_directory || !IgnoreNonExisting)
       return EC;
   }
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code rename(const Twine &from, const Twine &to) {
+std::error_code rename(const Twine &from, const Twine &to) {
   // Get arguments.
   SmallString<128> from_storage;
   SmallString<128> to_storage;
@@ -224,16 +231,18 @@ error_code rename(const Twine &from, const Twine &to) {
   // Convert to utf-16.
   SmallVector<wchar_t, 128> wide_from;
   SmallVector<wchar_t, 128> wide_to;
-  if (error_code ec = UTF8ToUTF16(f, wide_from)) return ec;
-  if (error_code ec = UTF8ToUTF16(t, wide_to)) return ec;
+  if (std::error_code ec = UTF8ToUTF16(f, wide_from))
+    return ec;
+  if (std::error_code ec = UTF8ToUTF16(t, wide_to))
+    return ec;
 
-  error_code ec = error_code::success();
+  std::error_code ec = std::error_code();
   for (int i = 0; i < 2000; i++) {
     if (::MoveFileExW(wide_from.begin(), wide_to.begin(),
                       MOVEFILE_COPY_ALLOWED | MOVEFILE_REPLACE_EXISTING))
-      return error_code::success();
-    ec = windows_error(::GetLastError());
-    if (ec != windows_error::access_denied)
+      return std::error_code();
+    DWORD LastError = ::GetLastError();
+    if (LastError != ERROR_ACCESS_DENIED)
       break;
     // Retry MoveFile() at ACCESS_DENIED.
     // System scanners (eg. indexer) might open the source file when
@@ -244,46 +253,46 @@ error_code rename(const Twine &from, const Twine &to) {
   return ec;
 }
 
-error_code resize_file(const Twine &path, uint64_t size) {
+std::error_code resize_file(const Twine &path, uint64_t size) {
   SmallString<128> path_storage;
   SmallVector<wchar_t, 128> path_utf16;
 
-  if (error_code ec = UTF8ToUTF16(path.toStringRef(path_storage),
-                                  path_utf16))
+  if (std::error_code ec =
+          UTF8ToUTF16(path.toStringRef(path_storage), path_utf16))
     return ec;
 
   int fd = ::_wopen(path_utf16.begin(), O_BINARY | _O_RDWR, S_IWRITE);
   if (fd == -1)
-    return error_code(errno, generic_category());
+    return std::error_code(errno, std::generic_category());
 #ifdef HAVE__CHSIZE_S
   errno_t error = ::_chsize_s(fd, size);
 #else
   errno_t error = ::_chsize(fd, size);
 #endif
   ::close(fd);
-  return error_code(error, generic_category());
+  return std::error_code(error, std::generic_category());
 }
 
-error_code exists(const Twine &path, bool &result) {
+std::error_code exists(const Twine &path, bool &result) {
   SmallString<128> path_storage;
   SmallVector<wchar_t, 128> path_utf16;
 
-  if (error_code ec = UTF8ToUTF16(path.toStringRef(path_storage),
-                                  path_utf16))
+  if (std::error_code ec =
+          UTF8ToUTF16(path.toStringRef(path_storage), path_utf16))
     return ec;
 
   DWORD attributes = ::GetFileAttributesW(path_utf16.begin());
 
   if (attributes == INVALID_FILE_ATTRIBUTES) {
     // See if the file didn't actually exist.
-    error_code ec = make_error_code(windows_error(::GetLastError()));
-    if (ec != windows_error::file_not_found &&
-        ec != windows_error::path_not_found)
-      return ec;
+    DWORD LastError = ::GetLastError();
+    if (LastError != ERROR_FILE_NOT_FOUND &&
+        LastError != ERROR_PATH_NOT_FOUND)
+      return windows_error(LastError);
     result = false;
   } else
     result = true;
-  return error_code::success();
+  return std::error_code();
 }
 
 bool can_write(const Twine &Path) {
@@ -320,12 +329,14 @@ bool equivalent(file_status A, file_status B) {
          A.VolumeSerialNumber == B.VolumeSerialNumber;
 }
 
-error_code equivalent(const Twine &A, const Twine &B, bool &result) {
+std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
   file_status fsA, fsB;
-  if (error_code ec = status(A, fsA)) return ec;
-  if (error_code ec = status(B, fsB)) return ec;
+  if (std::error_code ec = status(A, fsA))
+    return ec;
+  if (std::error_code ec = status(B, fsB))
+    return ec;
   result = equivalent(fsA, fsB);
-  return error_code::success();
+  return std::error_code();
 }
 
 static bool isReservedName(StringRef path) {
@@ -351,7 +362,7 @@ static bool isReservedName(StringRef path) {
   return false;
 }
 
-static error_code getStatus(HANDLE FileHandle, file_status &Result) {
+static std::error_code getStatus(HANDLE FileHandle, file_status &Result) {
   if (FileHandle == INVALID_HANDLE_VALUE)
     goto handle_status_error;
 
@@ -363,16 +374,16 @@ static error_code getStatus(HANDLE FileHandle, file_status &Result) {
     if (Err != NO_ERROR)
       return windows_error(Err);
     Result = file_status(file_type::type_unknown);
-    return error_code::success();
+    return std::error_code();
   }
   case FILE_TYPE_DISK:
     break;
   case FILE_TYPE_CHAR:
     Result = file_status(file_type::character_file);
-    return error_code::success();
+    return std::error_code();
   case FILE_TYPE_PIPE:
     Result = file_status(file_type::fifo_file);
-    return error_code::success();
+    return std::error_code();
   }
 
   BY_HANDLE_FILE_INFORMATION Info;
@@ -388,32 +399,32 @@ static error_code getStatus(HANDLE FileHandle, file_status &Result) {
                     Info.ftLastWriteTime.dwLowDateTime,
                     Info.dwVolumeSerialNumber, Info.nFileSizeHigh,
                     Info.nFileSizeLow, Info.nFileIndexHigh, Info.nFileIndexLow);
-    return error_code::success();
+    return std::error_code();
   }
 
 handle_status_error:
-  error_code EC = windows_error(::GetLastError());
-  if (EC == windows_error::file_not_found ||
-      EC == windows_error::path_not_found)
+  DWORD LastError = ::GetLastError();
+  if (LastError == ERROR_FILE_NOT_FOUND ||
+      LastError == ERROR_PATH_NOT_FOUND)
     Result = file_status(file_type::file_not_found);
-  else if (EC == windows_error::sharing_violation)
+  else if (LastError == ERROR_SHARING_VIOLATION)
     Result = file_status(file_type::type_unknown);
   else
     Result = file_status(file_type::status_error);
-  return EC;
+  return windows_error(LastError);
 }
 
-error_code status(const Twine &path, file_status &result) {
+std::error_code status(const Twine &path, file_status &result) {
   SmallString<128> path_storage;
   SmallVector<wchar_t, 128> path_utf16;
 
   StringRef path8 = path.toStringRef(path_storage);
   if (isReservedName(path8)) {
     result = file_status(file_type::character_file);
-    return error_code::success();
+    return std::error_code();
   }
 
-  if (error_code ec = UTF8ToUTF16(path8, path_utf16))
+  if (std::error_code ec = UTF8ToUTF16(path8, path_utf16))
     return ec;
 
   DWORD attr = ::GetFileAttributesW(path_utf16.begin());
@@ -444,12 +455,12 @@ error_code status(const Twine &path, file_status &result) {
     return getStatus(h, result);
 }
 
-error_code status(int FD, file_status &Result) {
+std::error_code status(int FD, file_status &Result) {
   HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
   return getStatus(FileHandle, Result);
 }
 
-error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
+std::error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
   ULARGE_INTEGER UI;
   UI.QuadPart = Time.toWin32Time();
   FILETIME FT;
@@ -458,52 +469,10 @@ error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
   HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
   if (!SetFileTime(FileHandle, NULL, &FT, &FT))
     return windows_error(::GetLastError());
-  return error_code::success();
-}
-
-error_code get_magic(const Twine &path, uint32_t len,
-                     SmallVectorImpl<char> &result) {
-  SmallString<128> path_storage;
-  SmallVector<wchar_t, 128> path_utf16;
-  result.set_size(0);
-
-  // Convert path to UTF-16.
-  if (error_code ec = UTF8ToUTF16(path.toStringRef(path_storage),
-                                  path_utf16))
-    return ec;
-
-  // Open file.
-  HANDLE file = ::CreateFileW(c_str(path_utf16),
-                              GENERIC_READ,
-                              FILE_SHARE_READ,
-                              NULL,
-                              OPEN_EXISTING,
-                              FILE_ATTRIBUTE_READONLY,
-                              NULL);
-  if (file == INVALID_HANDLE_VALUE)
-    return windows_error(::GetLastError());
-
-  // Allocate buffer.
-  result.reserve(len);
-
-  // Get magic!
-  DWORD bytes_read = 0;
-  BOOL read_success = ::ReadFile(file, result.data(), len, &bytes_read, NULL);
-  error_code ec = windows_error(::GetLastError());
-  ::CloseHandle(file);
-  if (!read_success || (bytes_read != len)) {
-    // Set result size to the number of bytes read if it's valid.
-    if (bytes_read <= len)
-      result.set_size(bytes_read);
-    // ERROR_HANDLE_EOF is mapped to errc::value_too_large.
-    return ec;
-  }
-
-  result.set_size(len);
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
+std::error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
   FileDescriptor = FD;
   // Make sure that the requested size fits within SIZE_T.
   if (Size > std::numeric_limits<SIZE_T>::max()) {
@@ -528,7 +497,7 @@ error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
                            (Offset + Size) & 0xffffffff,
                            0);
   if (FileMappingHandle == NULL) {
-    error_code ec = windows_error(GetLastError());
+    std::error_code ec = windows_error(GetLastError());
     if (FileDescriptor) {
       if (CloseFD)
         _close(FileDescriptor);
@@ -549,7 +518,7 @@ error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
                             Offset & 0xffffffff,
                             Size);
   if (Mapping == NULL) {
-    error_code ec = windows_error(GetLastError());
+    std::error_code ec = windows_error(GetLastError());
     ::CloseHandle(FileMappingHandle);
     if (FileDescriptor) {
       if (CloseFD)
@@ -563,7 +532,7 @@ error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
     MEMORY_BASIC_INFORMATION mbi;
     SIZE_T Result = VirtualQuery(Mapping, &mbi, sizeof(mbi));
     if (Result == 0) {
-      error_code ec = windows_error(GetLastError());
+      std::error_code ec = windows_error(GetLastError());
       ::UnmapViewOfFile(Mapping);
       ::CloseHandle(FileMappingHandle);
       if (FileDescriptor) {
@@ -584,14 +553,14 @@ error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
       _close(FileDescriptor); // Also closes FileHandle.
   } else
     ::CloseHandle(FileHandle);
-  return error_code::success();
+  return std::error_code();
 }
 
 mapped_file_region::mapped_file_region(const Twine &path,
                                        mapmode mode,
                                        uint64_t length,
                                        uint64_t offset,
-                                       error_code &ec)
+                                       std::error_code &ec)
   : Mode(mode)
   , Size(length)
   , Mapping()
@@ -636,7 +605,7 @@ mapped_file_region::mapped_file_region(int fd,
                                        mapmode mode,
                                        uint64_t length,
                                        uint64_t offset,
-                                       error_code &ec)
+                                       std::error_code &ec)
   : Mode(mode)
   , Size(length)
   , Mapping()
@@ -704,12 +673,11 @@ int mapped_file_region::alignment() {
   return SysInfo.dwAllocationGranularity;
 }
 
-error_code detail::directory_iterator_construct(detail::DirIterState &it,
+std::error_code detail::directory_iterator_construct(detail::DirIterState &it,
                                                 StringRef path){
   SmallVector<wchar_t, 128> path_utf16;
 
-  if (error_code ec = UTF8ToUTF16(path,
-                                  path_utf16))
+  if (std::error_code ec = UTF8ToUTF16(path, path_utf16))
     return ec;
 
   // Convert path to the format that Windows is happy with.
@@ -733,19 +701,19 @@ error_code detail::directory_iterator_construct(detail::DirIterState &it,
          (FilenameLen == 2 && FirstFind.cFileName[0] == L'.' &&
                               FirstFind.cFileName[1] == L'.'))
     if (!::FindNextFileW(FindHandle, &FirstFind)) {
-      error_code ec = windows_error(::GetLastError());
+      DWORD LastError = ::GetLastError();
       // Check for end.
-      if (ec == windows_error::no_more_files)
+      if (LastError == ERROR_NO_MORE_FILES)
         return detail::directory_iterator_destruct(it);
-      return ec;
+      return windows_error(LastError);
     } else
       FilenameLen = ::wcslen(FirstFind.cFileName);
 
   // Construct the current directory entry.
   SmallString<128> directory_entry_name_utf8;
-  if (error_code ec = UTF16ToUTF8(FirstFind.cFileName,
-                                  ::wcslen(FirstFind.cFileName),
-                                  directory_entry_name_utf8))
+  if (std::error_code ec =
+          UTF16ToUTF8(FirstFind.cFileName, ::wcslen(FirstFind.cFileName),
+                      directory_entry_name_utf8))
     return ec;
 
   it.IterationHandle = intptr_t(FindHandle.take());
@@ -753,26 +721,26 @@ error_code detail::directory_iterator_construct(detail::DirIterState &it,
   path::append(directory_entry_path, directory_entry_name_utf8.str());
   it.CurrentEntry = directory_entry(directory_entry_path.str());
 
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
+std::error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
   if (it.IterationHandle != 0)
     // Closes the handle if it's valid.
     ScopedFindHandle close(HANDLE(it.IterationHandle));
   it.IterationHandle = 0;
   it.CurrentEntry = directory_entry();
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code detail::directory_iterator_increment(detail::DirIterState &it) {
+std::error_code detail::directory_iterator_increment(detail::DirIterState &it) {
   WIN32_FIND_DATAW FindData;
   if (!::FindNextFileW(HANDLE(it.IterationHandle), &FindData)) {
-    error_code ec = windows_error(::GetLastError());
+    DWORD LastError = ::GetLastError();
     // Check for end.
-    if (ec == windows_error::no_more_files)
+    if (LastError == ERROR_NO_MORE_FILES)
       return detail::directory_iterator_destruct(it);
-    return ec;
+    return windows_error(LastError);
   }
 
   size_t FilenameLen = ::wcslen(FindData.cFileName);
@@ -782,60 +750,50 @@ error_code detail::directory_iterator_increment(detail::DirIterState &it) {
     return directory_iterator_increment(it);
 
   SmallString<128> directory_entry_path_utf8;
-  if (error_code ec = UTF16ToUTF8(FindData.cFileName,
-                                  ::wcslen(FindData.cFileName),
-                                  directory_entry_path_utf8))
+  if (std::error_code ec =
+          UTF16ToUTF8(FindData.cFileName, ::wcslen(FindData.cFileName),
+                      directory_entry_path_utf8))
     return ec;
 
   it.CurrentEntry.replace_filename(Twine(directory_entry_path_utf8));
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code map_file_pages(const Twine &path, off_t file_offset, size_t size,
-                                            bool map_writable, void *&result) {
-  assert(0 && "NOT IMPLEMENTED");
-  return windows_error::invalid_function;
-}
-
-error_code unmap_file_pages(void *base, size_t size) {
-  assert(0 && "NOT IMPLEMENTED");
-  return windows_error::invalid_function;
-}
-
-error_code openFileForRead(const Twine &Name, int &ResultFD) {
+std::error_code openFileForRead(const Twine &Name, int &ResultFD) {
   SmallString<128> PathStorage;
   SmallVector<wchar_t, 128> PathUTF16;
 
-  if (error_code EC = UTF8ToUTF16(Name.toStringRef(PathStorage),
-                                  PathUTF16))
+  if (std::error_code EC =
+          UTF8ToUTF16(Name.toStringRef(PathStorage), PathUTF16))
     return EC;
 
   HANDLE H = ::CreateFileW(PathUTF16.begin(), GENERIC_READ,
                            FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
                            OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
   if (H == INVALID_HANDLE_VALUE) {
-    error_code EC = windows_error(::GetLastError());
+    DWORD LastError = ::GetLastError();
+    std::error_code EC = windows_error(LastError);
     // Provide a better error message when trying to open directories.
     // This only runs if we failed to open the file, so there is probably
     // no performances issues.
-    if (EC != windows_error::access_denied)
+    if (LastError != ERROR_ACCESS_DENIED)
       return EC;
     if (is_directory(Name))
-      return error_code(errc::is_a_directory, posix_category());
+      return make_error_code(errc::is_a_directory);
     return EC;
   }
 
   int FD = ::_open_osfhandle(intptr_t(H), 0);
   if (FD == -1) {
     ::CloseHandle(H);
-    return windows_error::invalid_handle;
+    return windows_error(ERROR_INVALID_HANDLE);
   }
 
   ResultFD = FD;
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code openFileForWrite(const Twine &Name, int &ResultFD,
+std::error_code openFileForWrite(const Twine &Name, int &ResultFD,
                             sys::fs::OpenFlags Flags, unsigned Mode) {
   // Verify that we don't have both "append" and "excl".
   assert((!(Flags & sys::fs::F_Excl) || !(Flags & sys::fs::F_Append)) &&
@@ -844,8 +802,8 @@ error_code openFileForWrite(const Twine &Name, int &ResultFD,
   SmallString<128> PathStorage;
   SmallVector<wchar_t, 128> PathUTF16;
 
-  if (error_code EC = UTF8ToUTF16(Name.toStringRef(PathStorage),
-                                  PathUTF16))
+  if (std::error_code EC =
+          UTF8ToUTF16(Name.toStringRef(PathStorage), PathUTF16))
     return EC;
 
   DWORD CreationDisposition;
@@ -865,14 +823,15 @@ error_code openFileForWrite(const Twine &Name, int &ResultFD,
                            CreationDisposition, FILE_ATTRIBUTE_NORMAL, NULL);
 
   if (H == INVALID_HANDLE_VALUE) {
-    error_code EC = windows_error(::GetLastError());
+    DWORD LastError = ::GetLastError();
+    std::error_code EC = windows_error(LastError);
     // Provide a better error message when trying to open directories.
     // This only runs if we failed to open the file, so there is probably
     // no performances issues.
-    if (EC != windows_error::access_denied)
+    if (LastError != ERROR_ACCESS_DENIED)
       return EC;
     if (is_directory(Name))
-      return error_code(errc::is_a_directory, posix_category());
+      return make_error_code(errc::is_a_directory);
     return EC;
   }
 
@@ -886,11 +845,11 @@ error_code openFileForWrite(const Twine &Name, int &ResultFD,
   int FD = ::_open_osfhandle(intptr_t(H), OpenFlags);
   if (FD == -1) {
     ::CloseHandle(H);
-    return windows_error::invalid_handle;
+    return windows_error(ERROR_INVALID_HANDLE);
   }
 
   ResultFD = FD;
-  return error_code::success();
+  return std::error_code();
 }
 } // end namespace fs
 
@@ -911,14 +870,14 @@ bool home_directory(SmallVectorImpl<char> &result) {
 } // end namespace path
 
 namespace windows {
-llvm::error_code UTF8ToUTF16(llvm::StringRef utf8,
-                             llvm::SmallVectorImpl<wchar_t> &utf16) {
+std::error_code UTF8ToUTF16(llvm::StringRef utf8,
+                            llvm::SmallVectorImpl<wchar_t> &utf16) {
   if (!utf8.empty()) {
     int len = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, utf8.begin(),
                                     utf8.size(), utf16.begin(), 0);
 
     if (len == 0)
-      return llvm::windows_error(::GetLastError());
+      return windows_error(::GetLastError());
 
     utf16.reserve(len + 1);
     utf16.set_size(len);
@@ -927,25 +886,25 @@ llvm::error_code UTF8ToUTF16(llvm::StringRef utf8,
                                 utf8.size(), utf16.begin(), utf16.size());
 
     if (len == 0)
-      return llvm::windows_error(::GetLastError());
+      return windows_error(::GetLastError());
   }
 
   // Make utf16 null terminated.
   utf16.push_back(0);
   utf16.pop_back();
 
-  return llvm::error_code::success();
+  return std::error_code();
 }
 
-llvm::error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len,
-                             llvm::SmallVectorImpl<char> &utf8) {
+std::error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len,
+                            llvm::SmallVectorImpl<char> &utf8) {
   if (utf16_len) {
     // Get length.
     int len = ::WideCharToMultiByte(CP_UTF8, 0, utf16, utf16_len, utf8.begin(),
                                     0, NULL, NULL);
 
     if (len == 0)
-      return llvm::windows_error(::GetLastError());
+      return windows_error(::GetLastError());
 
     utf8.reserve(len);
     utf8.set_size(len);
@@ -955,14 +914,14 @@ llvm::error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len,
                                 utf8.size(), NULL, NULL);
 
     if (len == 0)
-      return llvm::windows_error(::GetLastError());
+      return windows_error(::GetLastError());
   }
 
   // Make utf8 null terminated.
   utf8.push_back(0);
   utf8.pop_back();
 
-  return llvm::error_code::success();
+  return std::error_code();
 }
 } // end namespace windows
 } // end namespace sys
diff --git a/lib/Support/Windows/Process.inc b/lib/Support/Windows/Process.inc
index c3df801..81aee0e 100644
--- a/lib/Support/Windows/Process.inc
+++ b/lib/Support/Windows/Process.inc
@@ -12,6 +12,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/Allocator.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/WindowsError.h"
 #include <malloc.h>
 
 // The Windows.h header must be after LLVM and standard headers.
@@ -47,7 +49,6 @@
 using namespace llvm;
 using namespace sys;
 
-
 process::id_type self_process::get_id() {
   return GetCurrentProcessId();
 }
@@ -178,12 +179,16 @@ Optional<std::string> Process::GetEnv(StringRef Name) {
   return std::string(Res.data());
 }
 
-error_code
+static std::error_code windows_error(DWORD E) {
+  return mapWindowsError(E);
+}
+
+std::error_code
 Process::GetArgumentVector(SmallVectorImpl<const char *> &Args,
                            ArrayRef<const char *>,
                            SpecificBumpPtrAllocator<char> &ArgAllocator) {
   int NewArgCount;
-  error_code ec;
+  std::error_code ec;
 
   wchar_t **UnicodeCommandLine = CommandLineToArgvW(GetCommandLineW(),
                                                     &NewArgCount);
@@ -208,7 +213,7 @@ Process::GetArgumentVector(SmallVectorImpl<const char *> &Args,
   if (ec)
     return ec;
 
-  return error_code::success();
+  return std::error_code();
 }
 
 bool Process::StandardInIsUserInput() {
@@ -363,12 +368,12 @@ unsigned Process::GetRandomNumber() {
   HCRYPTPROV HCPC;
   if (!::CryptAcquireContextW(&HCPC, NULL, NULL, PROV_RSA_FULL,
                               CRYPT_VERIFYCONTEXT))
-    assert(false && "Could not acquire a cryptographic context");
+    report_fatal_error("Could not acquire a cryptographic context");
 
   ScopedCryptContext CryptoProvider(HCPC);
   unsigned Ret;
   if (!::CryptGenRandom(CryptoProvider, sizeof(Ret),
                         reinterpret_cast<BYTE *>(&Ret)))
-    assert(false && "Could not generate a random number");
+    report_fatal_error("Could not generate a random number");
   return Ret;
 }
diff --git a/lib/Support/Windows/Program.inc b/lib/Support/Windows/Program.inc
index 5827c10..b2f71ae 100644
--- a/lib/Support/Windows/Program.inc
+++ b/lib/Support/Windows/Program.inc
@@ -226,7 +226,7 @@ static bool Execute(ProcessInfo &PI, StringRef Program, const char **args,
     // an environment block by concatenating them.
     for (unsigned i = 0; envp[i]; ++i) {
       SmallVector<wchar_t, MAX_PATH> EnvString;
-      if (error_code ec = windows::UTF8ToUTF16(envp[i], EnvString)) {
+      if (std::error_code ec = windows::UTF8ToUTF16(envp[i], EnvString)) {
         SetLastError(ec.value());
         MakeErrMsg(ErrMsg, "Unable to convert environment variable to UTF-16");
         return false;
@@ -290,7 +290,7 @@ static bool Execute(ProcessInfo &PI, StringRef Program, const char **args,
   fflush(stderr);
 
   SmallVector<wchar_t, MAX_PATH> ProgramUtf16;
-  if (error_code ec = windows::UTF8ToUTF16(Program, ProgramUtf16)) {
+  if (std::error_code ec = windows::UTF8ToUTF16(Program, ProgramUtf16)) {
     SetLastError(ec.value());
     MakeErrMsg(ErrMsg,
                std::string("Unable to convert application name to UTF-16"));
@@ -298,7 +298,7 @@ static bool Execute(ProcessInfo &PI, StringRef Program, const char **args,
   }
 
   SmallVector<wchar_t, MAX_PATH> CommandUtf16;
-  if (error_code ec = windows::UTF8ToUTF16(command.get(), CommandUtf16)) {
+  if (std::error_code ec = windows::UTF8ToUTF16(command.get(), CommandUtf16)) {
     SetLastError(ec.value());
     MakeErrMsg(ErrMsg,
                std::string("Unable to convert command-line to UTF-16"));
@@ -422,18 +422,18 @@ ProcessInfo sys::Wait(const ProcessInfo &PI, unsigned SecondsToWait,
   return WaitResult;
 }
 
-error_code sys::ChangeStdinToBinary(){
+  std::error_code sys::ChangeStdinToBinary(){
   int result = _setmode( _fileno(stdin), _O_BINARY );
   if (result == -1)
-    return error_code(errno, generic_category());
-  return make_error_code(errc::success);
+    return std::error_code(errno, std::generic_category());
+  return std::error_code();
 }
 
-error_code sys::ChangeStdoutToBinary(){
+  std::error_code sys::ChangeStdoutToBinary(){
   int result = _setmode( _fileno(stdout), _O_BINARY );
   if (result == -1)
-    return error_code(errno, generic_category());
-  return make_error_code(errc::success);
+    return std::error_code(errno, std::generic_category());
+  return std::error_code();
 }
 
 bool llvm::sys::argumentsFitWithinSystemLimits(ArrayRef<const char*> Args) {
diff --git a/lib/Support/Windows/WindowsSupport.h b/lib/Support/Windows/WindowsSupport.h
index 6bef444..f68835b 100644
--- a/lib/Support/Windows/WindowsSupport.h
+++ b/lib/Support/Windows/WindowsSupport.h
@@ -32,7 +32,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Config/config.h" // Get build system configuration settings
 #include "llvm/Support/Compiler.h"
-#include "llvm/Support/system_error.h"
+#include <system_error>
 #include <windows.h>
 #include <wincrypt.h>
 #include <cassert>
@@ -163,10 +163,9 @@ c_str(SmallVectorImpl<T> &str) {
 
 namespace sys {
 namespace windows {
-error_code UTF8ToUTF16(StringRef utf8,
-                       SmallVectorImpl<wchar_t> &utf16);
-error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len,
-                       SmallVectorImpl<char> &utf8);
+std::error_code UTF8ToUTF16(StringRef utf8, SmallVectorImpl<wchar_t> &utf16);
+std::error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len,
+                            SmallVectorImpl<char> &utf8);
 } // end namespace windows
 } // end namespace sys
 } // end namespace llvm.
diff --git a/lib/Support/Windows/system_error.inc b/lib/Support/Windows/system_error.inc
deleted file mode 100644
index 37ec81d..0000000
--- a/lib/Support/Windows/system_error.inc
+++ /dev/null
@@ -1,142 +0,0 @@
-//===- llvm/Support/Win32/system_error.inc - Windows error_code --*- 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 Windows specific implementation of the error_code
-// and error_condition classes.
-//
-//===----------------------------------------------------------------------===//
-
-//===----------------------------------------------------------------------===//
-//=== WARNING: Implementation here must contain only generic Windows code that
-//===          is guaranteed to work on *all* Windows variants.
-//===----------------------------------------------------------------------===//
-
-#include <windows.h>
-#include <winerror.h>
-
-using namespace llvm;
-
-std::string
-_system_error_category::message(int ev) const {
-  LPVOID lpMsgBuf = 0;
-  DWORD retval = ::FormatMessageA(
-    FORMAT_MESSAGE_ALLOCATE_BUFFER |
-    FORMAT_MESSAGE_FROM_SYSTEM |
-    FORMAT_MESSAGE_IGNORE_INSERTS,
-    NULL,
-    ev,
-    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
-    (LPSTR) &lpMsgBuf,
-    0,
-    NULL);
-  if (retval == 0) {
-    ::LocalFree(lpMsgBuf);
-    return std::string("Unknown error");
-  }
-
-  std::string str( static_cast<LPCSTR>(lpMsgBuf) );
-  ::LocalFree(lpMsgBuf);
-
-  while (str.size()
-     && (str[str.size()-1] == '\n' || str[str.size()-1] == '\r'))
-    str.erase( str.size()-1 );
-  if (str.size() && str[str.size()-1] == '.')
-    str.erase( str.size()-1 );
-  return str;
-}
-
-// I'd rather not double the line count of the following.
-#define MAP_ERR_TO_COND(x, y) case x: return make_error_condition(errc::y)
-
-error_condition
-_system_error_category::default_error_condition(int ev) const {
-  switch (ev) {
-  MAP_ERR_TO_COND(0, success);
-  // Windows system -> posix_errno decode table  ---------------------------//
-  // see WinError.h comments for descriptions of errors
-  MAP_ERR_TO_COND(ERROR_ACCESS_DENIED,       permission_denied);
-  MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS,      file_exists);
-  MAP_ERR_TO_COND(ERROR_BAD_UNIT,            no_such_device);
-  MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW,     filename_too_long);
-  MAP_ERR_TO_COND(ERROR_BUSY,                device_or_resource_busy);
-  MAP_ERR_TO_COND(ERROR_BUSY_DRIVE,          device_or_resource_busy);
-  MAP_ERR_TO_COND(ERROR_CANNOT_MAKE,         permission_denied);
-  MAP_ERR_TO_COND(ERROR_CANTOPEN,            io_error);
-  MAP_ERR_TO_COND(ERROR_CANTREAD,            io_error);
-  MAP_ERR_TO_COND(ERROR_CANTWRITE,           io_error);
-  MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY,   permission_denied);
-  MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST,       no_such_device);
-  MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE,       device_or_resource_busy);
-  MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY,       directory_not_empty);
-  MAP_ERR_TO_COND(ERROR_DIRECTORY,           invalid_argument);
-  MAP_ERR_TO_COND(ERROR_DISK_FULL,           no_space_on_device);
-  MAP_ERR_TO_COND(ERROR_FILE_EXISTS,         file_exists);
-  MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND,      no_such_file_or_directory);
-  MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL,    no_space_on_device);
-  MAP_ERR_TO_COND(ERROR_HANDLE_EOF,          value_too_large);
-  MAP_ERR_TO_COND(ERROR_INVALID_ACCESS,      permission_denied);
-  MAP_ERR_TO_COND(ERROR_INVALID_DRIVE,       no_such_device);
-  MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION,    function_not_supported);
-  MAP_ERR_TO_COND(ERROR_INVALID_HANDLE,      invalid_argument);
-  MAP_ERR_TO_COND(ERROR_INVALID_NAME,        invalid_argument);
-  MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION,      no_lock_available);
-  MAP_ERR_TO_COND(ERROR_LOCKED,              no_lock_available);
-  MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK,       invalid_argument);
-  MAP_ERR_TO_COND(ERROR_NOACCESS,            permission_denied);
-  MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY,   not_enough_memory);
-  MAP_ERR_TO_COND(ERROR_NOT_READY,           resource_unavailable_try_again);
-  MAP_ERR_TO_COND(ERROR_NOT_SAME_DEVICE,     cross_device_link);
-  MAP_ERR_TO_COND(ERROR_OPEN_FAILED,         io_error);
-  MAP_ERR_TO_COND(ERROR_OPEN_FILES,          device_or_resource_busy);
-  MAP_ERR_TO_COND(ERROR_OPERATION_ABORTED,   operation_canceled);
-  MAP_ERR_TO_COND(ERROR_OUTOFMEMORY,         not_enough_memory);
-  MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND,      no_such_file_or_directory);
-  MAP_ERR_TO_COND(ERROR_BAD_NETPATH,         no_such_file_or_directory);
-  MAP_ERR_TO_COND(ERROR_READ_FAULT,          io_error);
-  MAP_ERR_TO_COND(ERROR_RETRY,               resource_unavailable_try_again);
-  MAP_ERR_TO_COND(ERROR_SEEK,                io_error);
-  MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION,   permission_denied);
-  MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open);
-  MAP_ERR_TO_COND(ERROR_WRITE_FAULT,         io_error);
-  MAP_ERR_TO_COND(ERROR_WRITE_PROTECT,       permission_denied);
-  MAP_ERR_TO_COND(ERROR_SEM_TIMEOUT,         timed_out);
-  MAP_ERR_TO_COND(WSAEACCES,                 permission_denied);
-  MAP_ERR_TO_COND(WSAEADDRINUSE,             address_in_use);
-  MAP_ERR_TO_COND(WSAEADDRNOTAVAIL,          address_not_available);
-  MAP_ERR_TO_COND(WSAEAFNOSUPPORT,           address_family_not_supported);
-  MAP_ERR_TO_COND(WSAEALREADY,               connection_already_in_progress);
-  MAP_ERR_TO_COND(WSAEBADF,                  bad_file_descriptor);
-  MAP_ERR_TO_COND(WSAECONNABORTED,           connection_aborted);
-  MAP_ERR_TO_COND(WSAECONNREFUSED,           connection_refused);
-  MAP_ERR_TO_COND(WSAECONNRESET,             connection_reset);
-  MAP_ERR_TO_COND(WSAEDESTADDRREQ,           destination_address_required);
-  MAP_ERR_TO_COND(WSAEFAULT,                 bad_address);
-  MAP_ERR_TO_COND(WSAEHOSTUNREACH,           host_unreachable);
-  MAP_ERR_TO_COND(WSAEINPROGRESS,            operation_in_progress);
-  MAP_ERR_TO_COND(WSAEINTR,                  interrupted);
-  MAP_ERR_TO_COND(WSAEINVAL,                 invalid_argument);
-  MAP_ERR_TO_COND(WSAEISCONN,                already_connected);
-  MAP_ERR_TO_COND(WSAEMFILE,                 too_many_files_open);
-  MAP_ERR_TO_COND(WSAEMSGSIZE,               message_size);
-  MAP_ERR_TO_COND(WSAENAMETOOLONG,           filename_too_long);
-  MAP_ERR_TO_COND(WSAENETDOWN,               network_down);
-  MAP_ERR_TO_COND(WSAENETRESET,              network_reset);
-  MAP_ERR_TO_COND(WSAENETUNREACH,            network_unreachable);
-  MAP_ERR_TO_COND(WSAENOBUFS,                no_buffer_space);
-  MAP_ERR_TO_COND(WSAENOPROTOOPT,            no_protocol_option);
-  MAP_ERR_TO_COND(WSAENOTCONN,               not_connected);
-  MAP_ERR_TO_COND(WSAENOTSOCK,               not_a_socket);
-  MAP_ERR_TO_COND(WSAEOPNOTSUPP,             operation_not_supported);
-  MAP_ERR_TO_COND(WSAEPROTONOSUPPORT,        protocol_not_supported);
-  MAP_ERR_TO_COND(WSAEPROTOTYPE,             wrong_protocol_type);
-  MAP_ERR_TO_COND(WSAETIMEDOUT,              timed_out);
-  MAP_ERR_TO_COND(WSAEWOULDBLOCK,            operation_would_block);
-  default: return error_condition(ev, system_category());
-  }
-}