1//===- llvm/Support/Windows/Path.inc - Windows Path Impl --------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the Windows specific implementation of the Path API.
10//
11//===----------------------------------------------------------------------===//
12
13//===----------------------------------------------------------------------===//
14//=== WARNING: Implementation here must contain only generic Windows code that
15//===          is guaranteed to work on *all* Windows variants.
16//===----------------------------------------------------------------------===//
17
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/Support/ConvertUTF.h"
20#include "llvm/Support/WindowsError.h"
21#include <fcntl.h>
22#include <io.h>
23#include <sys/stat.h>
24#include <sys/types.h>
25
26// These two headers must be included last, and make sure shlobj is required
27// after Windows.h to make sure it picks up our definition of _WIN32_WINNT
28#include "llvm/Support/Windows/WindowsSupport.h"
29#include <shellapi.h>
30#include <shlobj.h>
31
32#undef max
33
34// MinGW doesn't define this.
35#ifndef _ERRNO_T_DEFINED
36#define _ERRNO_T_DEFINED
37typedef int errno_t;
38#endif
39
40#ifdef _MSC_VER
41# pragma comment(lib, "advapi32.lib")  // This provides CryptAcquireContextW.
42# pragma comment(lib, "ole32.lib")     // This provides CoTaskMemFree
43#endif
44
45using namespace llvm;
46
47using llvm::sys::windows::UTF8ToUTF16;
48using llvm::sys::windows::CurCPToUTF16;
49using llvm::sys::windows::UTF16ToUTF8;
50using llvm::sys::path::widenPath;
51
52static bool is_separator(const wchar_t value) {
53  switch (value) {
54  case L'\\':
55  case L'/':
56    return true;
57  default:
58    return false;
59  }
60}
61
62namespace llvm {
63namespace sys  {
64namespace path {
65
66// Convert a UTF-8 path to UTF-16.  Also, if the absolute equivalent of the
67// path is longer than CreateDirectory can tolerate, make it absolute and
68// prefixed by '\\?\'.
69std::error_code widenPath(const Twine &Path8,
70                          SmallVectorImpl<wchar_t> &Path16) {
71  const size_t MaxDirLen = MAX_PATH - 12; // Must leave room for 8.3 filename.
72
73  // Several operations would convert Path8 to SmallString; more efficient to
74  // do it once up front.
75  SmallString<128> Path8Str;
76  Path8.toVector(Path8Str);
77
78  // If we made this path absolute, how much longer would it get?
79  size_t CurPathLen;
80  if (llvm::sys::path::is_absolute(Twine(Path8Str)))
81    CurPathLen = 0; // No contribution from current_path needed.
82  else {
83    CurPathLen = ::GetCurrentDirectoryW(0, NULL);
84    if (CurPathLen == 0)
85      return mapWindowsError(::GetLastError());
86  }
87
88  // Would the absolute path be longer than our limit?
89  if ((Path8Str.size() + CurPathLen) >= MaxDirLen &&
90      !Path8Str.startswith("\\\\?\\")) {
91    SmallString<2*MAX_PATH> FullPath("\\\\?\\");
92    if (CurPathLen) {
93      SmallString<80> CurPath;
94      if (std::error_code EC = llvm::sys::fs::current_path(CurPath))
95        return EC;
96      FullPath.append(CurPath);
97    }
98    // Traverse the requested path, canonicalizing . and .. (because the \\?\
99    // prefix is documented to treat them as real components).  Ignore
100    // separators, which can be returned from the iterator if the path has a
101    // drive name.  We don't need to call native() on the result since append()
102    // always attaches preferred_separator.
103    for (llvm::sys::path::const_iterator I = llvm::sys::path::begin(Path8Str),
104                                         E = llvm::sys::path::end(Path8Str);
105                                         I != E; ++I) {
106      if (I->size() == 1 && is_separator((*I)[0]))
107        continue;
108      if (I->size() == 1 && *I == ".")
109        continue;
110      if (I->size() == 2 && *I == "..")
111        llvm::sys::path::remove_filename(FullPath);
112      else
113        llvm::sys::path::append(FullPath, *I);
114    }
115    return UTF8ToUTF16(FullPath, Path16);
116  }
117
118  // Just use the caller's original path.
119  return UTF8ToUTF16(Path8Str, Path16);
120}
121} // end namespace path
122
123namespace fs {
124
125const file_t kInvalidFile = INVALID_HANDLE_VALUE;
126
127std::string getMainExecutable(const char *argv0, void *MainExecAddr) {
128  SmallVector<wchar_t, MAX_PATH> PathName;
129  DWORD Size = ::GetModuleFileNameW(NULL, PathName.data(), PathName.capacity());
130
131  // A zero return value indicates a failure other than insufficient space.
132  if (Size == 0)
133    return "";
134
135  // Insufficient space is determined by a return value equal to the size of
136  // the buffer passed in.
137  if (Size == PathName.capacity())
138    return "";
139
140  // On success, GetModuleFileNameW returns the number of characters written to
141  // the buffer not including the NULL terminator.
142  PathName.set_size(Size);
143
144  // Convert the result from UTF-16 to UTF-8.
145  SmallVector<char, MAX_PATH> PathNameUTF8;
146  if (UTF16ToUTF8(PathName.data(), PathName.size(), PathNameUTF8))
147    return "";
148
149  return std::string(PathNameUTF8.data());
150}
151
152UniqueID file_status::getUniqueID() const {
153  // The file is uniquely identified by the volume serial number along
154  // with the 64-bit file identifier.
155  uint64_t FileID = (static_cast<uint64_t>(FileIndexHigh) << 32ULL) |
156                    static_cast<uint64_t>(FileIndexLow);
157
158  return UniqueID(VolumeSerialNumber, FileID);
159}
160
161ErrorOr<space_info> disk_space(const Twine &Path) {
162  ULARGE_INTEGER Avail, Total, Free;
163  if (!::GetDiskFreeSpaceExA(Path.str().c_str(), &Avail, &Total, &Free))
164    return mapWindowsError(::GetLastError());
165  space_info SpaceInfo;
166  SpaceInfo.capacity =
167      (static_cast<uint64_t>(Total.HighPart) << 32) + Total.LowPart;
168  SpaceInfo.free = (static_cast<uint64_t>(Free.HighPart) << 32) + Free.LowPart;
169  SpaceInfo.available =
170      (static_cast<uint64_t>(Avail.HighPart) << 32) + Avail.LowPart;
171  return SpaceInfo;
172}
173
174TimePoint<> basic_file_status::getLastAccessedTime() const {
175  FILETIME Time;
176  Time.dwLowDateTime = LastAccessedTimeLow;
177  Time.dwHighDateTime = LastAccessedTimeHigh;
178  return toTimePoint(Time);
179}
180
181TimePoint<> basic_file_status::getLastModificationTime() const {
182  FILETIME Time;
183  Time.dwLowDateTime = LastWriteTimeLow;
184  Time.dwHighDateTime = LastWriteTimeHigh;
185  return toTimePoint(Time);
186}
187
188uint32_t file_status::getLinkCount() const {
189  return NumLinks;
190}
191
192std::error_code current_path(SmallVectorImpl<char> &result) {
193  SmallVector<wchar_t, MAX_PATH> cur_path;
194  DWORD len = MAX_PATH;
195
196  do {
197    cur_path.reserve(len);
198    len = ::GetCurrentDirectoryW(cur_path.capacity(), cur_path.data());
199
200    // A zero return value indicates a failure other than insufficient space.
201    if (len == 0)
202      return mapWindowsError(::GetLastError());
203
204    // If there's insufficient space, the len returned is larger than the len
205    // given.
206  } while (len > cur_path.capacity());
207
208  // On success, GetCurrentDirectoryW returns the number of characters not
209  // including the null-terminator.
210  cur_path.set_size(len);
211  return UTF16ToUTF8(cur_path.begin(), cur_path.size(), result);
212}
213
214std::error_code set_current_path(const Twine &path) {
215  // Convert to utf-16.
216  SmallVector<wchar_t, 128> wide_path;
217  if (std::error_code ec = widenPath(path, wide_path))
218    return ec;
219
220  if (!::SetCurrentDirectoryW(wide_path.begin()))
221    return mapWindowsError(::GetLastError());
222
223  return std::error_code();
224}
225
226std::error_code create_directory(const Twine &path, bool IgnoreExisting,
227                                 perms Perms) {
228  SmallVector<wchar_t, 128> path_utf16;
229
230  if (std::error_code ec = widenPath(path, path_utf16))
231    return ec;
232
233  if (!::CreateDirectoryW(path_utf16.begin(), NULL)) {
234    DWORD LastError = ::GetLastError();
235    if (LastError != ERROR_ALREADY_EXISTS || !IgnoreExisting)
236      return mapWindowsError(LastError);
237  }
238
239  return std::error_code();
240}
241
242// We can't use symbolic links for windows.
243std::error_code create_link(const Twine &to, const Twine &from) {
244  // Convert to utf-16.
245  SmallVector<wchar_t, 128> wide_from;
246  SmallVector<wchar_t, 128> wide_to;
247  if (std::error_code ec = widenPath(from, wide_from))
248    return ec;
249  if (std::error_code ec = widenPath(to, wide_to))
250    return ec;
251
252  if (!::CreateHardLinkW(wide_from.begin(), wide_to.begin(), NULL))
253    return mapWindowsError(::GetLastError());
254
255  return std::error_code();
256}
257
258std::error_code create_hard_link(const Twine &to, const Twine &from) {
259  return create_link(to, from);
260}
261
262std::error_code remove(const Twine &path, bool IgnoreNonExisting) {
263  SmallVector<wchar_t, 128> path_utf16;
264
265  if (std::error_code ec = widenPath(path, path_utf16))
266    return ec;
267
268  // We don't know whether this is a file or a directory, and remove() can
269  // accept both. The usual way to delete a file or directory is to use one of
270  // the DeleteFile or RemoveDirectory functions, but that requires you to know
271  // which one it is. We could stat() the file to determine that, but that would
272  // cost us additional system calls, which can be slow in a directory
273  // containing a large number of files. So instead we call CreateFile directly.
274  // The important part is the FILE_FLAG_DELETE_ON_CLOSE flag, which causes the
275  // file to be deleted once it is closed. We also use the flags
276  // FILE_FLAG_BACKUP_SEMANTICS (which allows us to open directories), and
277  // FILE_FLAG_OPEN_REPARSE_POINT (don't follow symlinks).
278  ScopedFileHandle h(::CreateFileW(
279      c_str(path_utf16), DELETE,
280      FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
281      OPEN_EXISTING,
282      FILE_ATTRIBUTE_NORMAL | FILE_FLAG_BACKUP_SEMANTICS |
283          FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_DELETE_ON_CLOSE,
284      NULL));
285  if (!h) {
286    std::error_code EC = mapWindowsError(::GetLastError());
287    if (EC != errc::no_such_file_or_directory || !IgnoreNonExisting)
288      return EC;
289  }
290
291  return std::error_code();
292}
293
294static std::error_code is_local_internal(SmallVectorImpl<wchar_t> &Path,
295                                         bool &Result) {
296  SmallVector<wchar_t, 128> VolumePath;
297  size_t Len = 128;
298  while (true) {
299    VolumePath.resize(Len);
300    BOOL Success =
301        ::GetVolumePathNameW(Path.data(), VolumePath.data(), VolumePath.size());
302
303    if (Success)
304      break;
305
306    DWORD Err = ::GetLastError();
307    if (Err != ERROR_INSUFFICIENT_BUFFER)
308      return mapWindowsError(Err);
309
310    Len *= 2;
311  }
312  // If the output buffer has exactly enough space for the path name, but not
313  // the null terminator, it will leave the output unterminated.  Push a null
314  // terminator onto the end to ensure that this never happens.
315  VolumePath.push_back(L'\0');
316  VolumePath.set_size(wcslen(VolumePath.data()));
317  const wchar_t *P = VolumePath.data();
318
319  UINT Type = ::GetDriveTypeW(P);
320  switch (Type) {
321  case DRIVE_FIXED:
322    Result = true;
323    return std::error_code();
324  case DRIVE_REMOTE:
325  case DRIVE_CDROM:
326  case DRIVE_RAMDISK:
327  case DRIVE_REMOVABLE:
328    Result = false;
329    return std::error_code();
330  default:
331    return make_error_code(errc::no_such_file_or_directory);
332  }
333  llvm_unreachable("Unreachable!");
334}
335
336std::error_code is_local(const Twine &path, bool &result) {
337  if (!llvm::sys::fs::exists(path) || !llvm::sys::path::has_root_path(path))
338    return make_error_code(errc::no_such_file_or_directory);
339
340  SmallString<128> Storage;
341  StringRef P = path.toStringRef(Storage);
342
343  // Convert to utf-16.
344  SmallVector<wchar_t, 128> WidePath;
345  if (std::error_code ec = widenPath(P, WidePath))
346    return ec;
347  return is_local_internal(WidePath, result);
348}
349
350static std::error_code realPathFromHandle(HANDLE H,
351                                          SmallVectorImpl<wchar_t> &Buffer) {
352  DWORD CountChars = ::GetFinalPathNameByHandleW(
353      H, Buffer.begin(), Buffer.capacity() - 1, FILE_NAME_NORMALIZED);
354  if (CountChars > Buffer.capacity()) {
355    // The buffer wasn't big enough, try again.  In this case the return value
356    // *does* indicate the size of the null terminator.
357    Buffer.reserve(CountChars);
358    CountChars = ::GetFinalPathNameByHandleW(
359        H, Buffer.data(), Buffer.capacity() - 1, FILE_NAME_NORMALIZED);
360  }
361  if (CountChars == 0)
362    return mapWindowsError(GetLastError());
363  Buffer.set_size(CountChars);
364  return std::error_code();
365}
366
367static std::error_code realPathFromHandle(HANDLE H,
368                                          SmallVectorImpl<char> &RealPath) {
369  RealPath.clear();
370  SmallVector<wchar_t, MAX_PATH> Buffer;
371  if (std::error_code EC = realPathFromHandle(H, Buffer))
372    return EC;
373
374  // Strip the \\?\ prefix. We don't want it ending up in output, and such
375  // paths don't get canonicalized by file APIs.
376  wchar_t *Data = Buffer.data();
377  DWORD CountChars = Buffer.size();
378  if (CountChars >= 8 && ::memcmp(Data, L"\\\\?\\UNC\\", 16) == 0) {
379    // Convert \\?\UNC\foo\bar to \\foo\bar
380    CountChars -= 6;
381    Data += 6;
382    Data[0] = '\\';
383  } else if (CountChars >= 4 && ::memcmp(Data, L"\\\\?\\", 8) == 0) {
384    // Convert \\?\c:\foo to c:\foo
385    CountChars -= 4;
386    Data += 4;
387  }
388
389  // Convert the result from UTF-16 to UTF-8.
390  return UTF16ToUTF8(Data, CountChars, RealPath);
391}
392
393std::error_code is_local(int FD, bool &Result) {
394  SmallVector<wchar_t, 128> FinalPath;
395  HANDLE Handle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
396
397  if (std::error_code EC = realPathFromHandle(Handle, FinalPath))
398    return EC;
399
400  return is_local_internal(FinalPath, Result);
401}
402
403static std::error_code setDeleteDisposition(HANDLE Handle, bool Delete) {
404  FILE_DISPOSITION_INFO Disposition;
405  Disposition.DeleteFile = Delete;
406  if (!SetFileInformationByHandle(Handle, FileDispositionInfo, &Disposition,
407                                  sizeof(Disposition)))
408    return mapWindowsError(::GetLastError());
409  return std::error_code();
410}
411
412static std::error_code rename_internal(HANDLE FromHandle, const Twine &To,
413                                       bool ReplaceIfExists) {
414  SmallVector<wchar_t, 0> ToWide;
415  if (auto EC = widenPath(To, ToWide))
416    return EC;
417
418  std::vector<char> RenameInfoBuf(sizeof(FILE_RENAME_INFO) - sizeof(wchar_t) +
419                                  (ToWide.size() * sizeof(wchar_t)));
420  FILE_RENAME_INFO &RenameInfo =
421      *reinterpret_cast<FILE_RENAME_INFO *>(RenameInfoBuf.data());
422  RenameInfo.ReplaceIfExists = ReplaceIfExists;
423  RenameInfo.RootDirectory = 0;
424  RenameInfo.FileNameLength = ToWide.size() * sizeof(wchar_t);
425  std::copy(ToWide.begin(), ToWide.end(), &RenameInfo.FileName[0]);
426
427  SetLastError(ERROR_SUCCESS);
428  if (!SetFileInformationByHandle(FromHandle, FileRenameInfo, &RenameInfo,
429                                  RenameInfoBuf.size())) {
430    unsigned Error = GetLastError();
431    if (Error == ERROR_SUCCESS)
432      Error = ERROR_CALL_NOT_IMPLEMENTED; // Wine doesn't always set error code.
433    return mapWindowsError(Error);
434  }
435
436  return std::error_code();
437}
438
439static std::error_code rename_handle(HANDLE FromHandle, const Twine &To) {
440  SmallVector<wchar_t, 128> WideTo;
441  if (std::error_code EC = widenPath(To, WideTo))
442    return EC;
443
444  // We normally expect this loop to succeed after a few iterations. If it
445  // requires more than 200 tries, it's more likely that the failures are due to
446  // a true error, so stop trying.
447  for (unsigned Retry = 0; Retry != 200; ++Retry) {
448    auto EC = rename_internal(FromHandle, To, true);
449
450    if (EC ==
451        std::error_code(ERROR_CALL_NOT_IMPLEMENTED, std::system_category())) {
452      // Wine doesn't support SetFileInformationByHandle in rename_internal.
453      // Fall back to MoveFileEx.
454      SmallVector<wchar_t, MAX_PATH> WideFrom;
455      if (std::error_code EC2 = realPathFromHandle(FromHandle, WideFrom))
456        return EC2;
457      if (::MoveFileExW(WideFrom.begin(), WideTo.begin(),
458                        MOVEFILE_REPLACE_EXISTING))
459        return std::error_code();
460      return mapWindowsError(GetLastError());
461    }
462
463    if (!EC || EC != errc::permission_denied)
464      return EC;
465
466    // The destination file probably exists and is currently open in another
467    // process, either because the file was opened without FILE_SHARE_DELETE or
468    // it is mapped into memory (e.g. using MemoryBuffer). Rename it in order to
469    // move it out of the way of the source file. Use FILE_FLAG_DELETE_ON_CLOSE
470    // to arrange for the destination file to be deleted when the other process
471    // closes it.
472    ScopedFileHandle ToHandle(
473        ::CreateFileW(WideTo.begin(), GENERIC_READ | DELETE,
474                      FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
475                      NULL, OPEN_EXISTING,
476                      FILE_ATTRIBUTE_NORMAL | FILE_FLAG_DELETE_ON_CLOSE, NULL));
477    if (!ToHandle) {
478      auto EC = mapWindowsError(GetLastError());
479      // Another process might have raced with us and moved the existing file
480      // out of the way before we had a chance to open it. If that happens, try
481      // to rename the source file again.
482      if (EC == errc::no_such_file_or_directory)
483        continue;
484      return EC;
485    }
486
487    BY_HANDLE_FILE_INFORMATION FI;
488    if (!GetFileInformationByHandle(ToHandle, &FI))
489      return mapWindowsError(GetLastError());
490
491    // Try to find a unique new name for the destination file.
492    for (unsigned UniqueId = 0; UniqueId != 200; ++UniqueId) {
493      std::string TmpFilename = (To + ".tmp" + utostr(UniqueId)).str();
494      if (auto EC = rename_internal(ToHandle, TmpFilename, false)) {
495        if (EC == errc::file_exists || EC == errc::permission_denied) {
496          // Again, another process might have raced with us and moved the file
497          // before we could move it. Check whether this is the case, as it
498          // might have caused the permission denied error. If that was the
499          // case, we don't need to move it ourselves.
500          ScopedFileHandle ToHandle2(::CreateFileW(
501              WideTo.begin(), 0,
502              FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
503              OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL));
504          if (!ToHandle2) {
505            auto EC = mapWindowsError(GetLastError());
506            if (EC == errc::no_such_file_or_directory)
507              break;
508            return EC;
509          }
510          BY_HANDLE_FILE_INFORMATION FI2;
511          if (!GetFileInformationByHandle(ToHandle2, &FI2))
512            return mapWindowsError(GetLastError());
513          if (FI.nFileIndexHigh != FI2.nFileIndexHigh ||
514              FI.nFileIndexLow != FI2.nFileIndexLow ||
515              FI.dwVolumeSerialNumber != FI2.dwVolumeSerialNumber)
516            break;
517          continue;
518        }
519        return EC;
520      }
521      break;
522    }
523
524    // Okay, the old destination file has probably been moved out of the way at
525    // this point, so try to rename the source file again. Still, another
526    // process might have raced with us to create and open the destination
527    // file, so we need to keep doing this until we succeed.
528  }
529
530  // The most likely root cause.
531  return errc::permission_denied;
532}
533
534static std::error_code rename_fd(int FromFD, const Twine &To) {
535  HANDLE FromHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FromFD));
536  return rename_handle(FromHandle, To);
537}
538
539std::error_code rename(const Twine &From, const Twine &To) {
540  // Convert to utf-16.
541  SmallVector<wchar_t, 128> WideFrom;
542  if (std::error_code EC = widenPath(From, WideFrom))
543    return EC;
544
545  ScopedFileHandle FromHandle;
546  // Retry this a few times to defeat badly behaved file system scanners.
547  for (unsigned Retry = 0; Retry != 200; ++Retry) {
548    if (Retry != 0)
549      ::Sleep(10);
550    FromHandle =
551        ::CreateFileW(WideFrom.begin(), GENERIC_READ | DELETE,
552                      FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
553                      NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
554    if (FromHandle)
555      break;
556  }
557  if (!FromHandle)
558    return mapWindowsError(GetLastError());
559
560  return rename_handle(FromHandle, To);
561}
562
563std::error_code resize_file(int FD, uint64_t Size) {
564#ifdef HAVE__CHSIZE_S
565  errno_t error = ::_chsize_s(FD, Size);
566#else
567  errno_t error = ::_chsize(FD, Size);
568#endif
569  return std::error_code(error, std::generic_category());
570}
571
572std::error_code access(const Twine &Path, AccessMode Mode) {
573  SmallVector<wchar_t, 128> PathUtf16;
574
575  if (std::error_code EC = widenPath(Path, PathUtf16))
576    return EC;
577
578  DWORD Attributes = ::GetFileAttributesW(PathUtf16.begin());
579
580  if (Attributes == INVALID_FILE_ATTRIBUTES) {
581    // See if the file didn't actually exist.
582    DWORD LastError = ::GetLastError();
583    if (LastError != ERROR_FILE_NOT_FOUND &&
584        LastError != ERROR_PATH_NOT_FOUND)
585      return mapWindowsError(LastError);
586    return errc::no_such_file_or_directory;
587  }
588
589  if (Mode == AccessMode::Write && (Attributes & FILE_ATTRIBUTE_READONLY))
590    return errc::permission_denied;
591
592  return std::error_code();
593}
594
595bool can_execute(const Twine &Path) {
596  return !access(Path, AccessMode::Execute) ||
597         !access(Path + ".exe", AccessMode::Execute);
598}
599
600bool equivalent(file_status A, file_status B) {
601  assert(status_known(A) && status_known(B));
602  return A.FileIndexHigh         == B.FileIndexHigh &&
603         A.FileIndexLow          == B.FileIndexLow &&
604         A.FileSizeHigh          == B.FileSizeHigh &&
605         A.FileSizeLow           == B.FileSizeLow &&
606         A.LastAccessedTimeHigh  == B.LastAccessedTimeHigh &&
607         A.LastAccessedTimeLow   == B.LastAccessedTimeLow &&
608         A.LastWriteTimeHigh     == B.LastWriteTimeHigh &&
609         A.LastWriteTimeLow      == B.LastWriteTimeLow &&
610         A.VolumeSerialNumber    == B.VolumeSerialNumber;
611}
612
613std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
614  file_status fsA, fsB;
615  if (std::error_code ec = status(A, fsA))
616    return ec;
617  if (std::error_code ec = status(B, fsB))
618    return ec;
619  result = equivalent(fsA, fsB);
620  return std::error_code();
621}
622
623static bool isReservedName(StringRef path) {
624  // This list of reserved names comes from MSDN, at:
625  // http://msdn.microsoft.com/en-us/library/aa365247%28v=vs.85%29.aspx
626  static const char *const sReservedNames[] = { "nul", "con", "prn", "aux",
627                                                "com1", "com2", "com3", "com4",
628                                                "com5", "com6", "com7", "com8",
629                                                "com9", "lpt1", "lpt2", "lpt3",
630                                                "lpt4", "lpt5", "lpt6", "lpt7",
631                                                "lpt8", "lpt9" };
632
633  // First, check to see if this is a device namespace, which always
634  // starts with \\.\, since device namespaces are not legal file paths.
635  if (path.startswith("\\\\.\\"))
636    return true;
637
638  // Then compare against the list of ancient reserved names.
639  for (size_t i = 0; i < array_lengthof(sReservedNames); ++i) {
640    if (path.equals_lower(sReservedNames[i]))
641      return true;
642  }
643
644  // The path isn't what we consider reserved.
645  return false;
646}
647
648static file_type file_type_from_attrs(DWORD Attrs) {
649  return (Attrs & FILE_ATTRIBUTE_DIRECTORY) ? file_type::directory_file
650                                            : file_type::regular_file;
651}
652
653static perms perms_from_attrs(DWORD Attrs) {
654  return (Attrs & FILE_ATTRIBUTE_READONLY) ? (all_read | all_exe) : all_all;
655}
656
657static std::error_code getStatus(HANDLE FileHandle, file_status &Result) {
658  if (FileHandle == INVALID_HANDLE_VALUE)
659    goto handle_status_error;
660
661  switch (::GetFileType(FileHandle)) {
662  default:
663    llvm_unreachable("Don't know anything about this file type");
664  case FILE_TYPE_UNKNOWN: {
665    DWORD Err = ::GetLastError();
666    if (Err != NO_ERROR)
667      return mapWindowsError(Err);
668    Result = file_status(file_type::type_unknown);
669    return std::error_code();
670  }
671  case FILE_TYPE_DISK:
672    break;
673  case FILE_TYPE_CHAR:
674    Result = file_status(file_type::character_file);
675    return std::error_code();
676  case FILE_TYPE_PIPE:
677    Result = file_status(file_type::fifo_file);
678    return std::error_code();
679  }
680
681  BY_HANDLE_FILE_INFORMATION Info;
682  if (!::GetFileInformationByHandle(FileHandle, &Info))
683    goto handle_status_error;
684
685  Result = file_status(
686      file_type_from_attrs(Info.dwFileAttributes),
687      perms_from_attrs(Info.dwFileAttributes), Info.nNumberOfLinks,
688      Info.ftLastAccessTime.dwHighDateTime, Info.ftLastAccessTime.dwLowDateTime,
689      Info.ftLastWriteTime.dwHighDateTime, Info.ftLastWriteTime.dwLowDateTime,
690      Info.dwVolumeSerialNumber, Info.nFileSizeHigh, Info.nFileSizeLow,
691      Info.nFileIndexHigh, Info.nFileIndexLow);
692  return std::error_code();
693
694handle_status_error:
695  DWORD LastError = ::GetLastError();
696  if (LastError == ERROR_FILE_NOT_FOUND ||
697      LastError == ERROR_PATH_NOT_FOUND)
698    Result = file_status(file_type::file_not_found);
699  else if (LastError == ERROR_SHARING_VIOLATION)
700    Result = file_status(file_type::type_unknown);
701  else
702    Result = file_status(file_type::status_error);
703  return mapWindowsError(LastError);
704}
705
706std::error_code status(const Twine &path, file_status &result, bool Follow) {
707  SmallString<128> path_storage;
708  SmallVector<wchar_t, 128> path_utf16;
709
710  StringRef path8 = path.toStringRef(path_storage);
711  if (isReservedName(path8)) {
712    result = file_status(file_type::character_file);
713    return std::error_code();
714  }
715
716  if (std::error_code ec = widenPath(path8, path_utf16))
717    return ec;
718
719  DWORD attr = ::GetFileAttributesW(path_utf16.begin());
720  if (attr == INVALID_FILE_ATTRIBUTES)
721    return getStatus(INVALID_HANDLE_VALUE, result);
722
723  DWORD Flags = FILE_FLAG_BACKUP_SEMANTICS;
724  // Handle reparse points.
725  if (!Follow && (attr & FILE_ATTRIBUTE_REPARSE_POINT))
726    Flags |= FILE_FLAG_OPEN_REPARSE_POINT;
727
728  ScopedFileHandle h(
729      ::CreateFileW(path_utf16.begin(), 0, // Attributes only.
730                    FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
731                    NULL, OPEN_EXISTING, Flags, 0));
732  if (!h)
733    return getStatus(INVALID_HANDLE_VALUE, result);
734
735  return getStatus(h, result);
736}
737
738std::error_code status(int FD, file_status &Result) {
739  HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
740  return getStatus(FileHandle, Result);
741}
742
743std::error_code status(file_t FileHandle, file_status &Result) {
744  return getStatus(FileHandle, Result);
745}
746
747unsigned getUmask() {
748  return 0;
749}
750
751std::error_code setPermissions(const Twine &Path, perms Permissions) {
752  SmallVector<wchar_t, 128> PathUTF16;
753  if (std::error_code EC = widenPath(Path, PathUTF16))
754    return EC;
755
756  DWORD Attributes = ::GetFileAttributesW(PathUTF16.begin());
757  if (Attributes == INVALID_FILE_ATTRIBUTES)
758    return mapWindowsError(GetLastError());
759
760  // There are many Windows file attributes that are not to do with the file
761  // permissions (e.g. FILE_ATTRIBUTE_HIDDEN). We need to be careful to preserve
762  // them.
763  if (Permissions & all_write) {
764    Attributes &= ~FILE_ATTRIBUTE_READONLY;
765    if (Attributes == 0)
766      // FILE_ATTRIBUTE_NORMAL indicates no other attributes are set.
767      Attributes |= FILE_ATTRIBUTE_NORMAL;
768  }
769  else {
770    Attributes |= FILE_ATTRIBUTE_READONLY;
771    // FILE_ATTRIBUTE_NORMAL is not compatible with any other attributes, so
772    // remove it, if it is present.
773    Attributes &= ~FILE_ATTRIBUTE_NORMAL;
774  }
775
776  if (!::SetFileAttributesW(PathUTF16.begin(), Attributes))
777    return mapWindowsError(GetLastError());
778
779  return std::error_code();
780}
781
782std::error_code setPermissions(int FD, perms Permissions) {
783  // FIXME Not implemented.
784  return std::make_error_code(std::errc::not_supported);
785}
786
787std::error_code setLastAccessAndModificationTime(int FD, TimePoint<> AccessTime,
788                                                 TimePoint<> ModificationTime) {
789  FILETIME AccessFT = toFILETIME(AccessTime);
790  FILETIME ModifyFT = toFILETIME(ModificationTime);
791  HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
792  if (!SetFileTime(FileHandle, NULL, &AccessFT, &ModifyFT))
793    return mapWindowsError(::GetLastError());
794  return std::error_code();
795}
796
797std::error_code mapped_file_region::init(sys::fs::file_t OrigFileHandle,
798                                         uint64_t Offset, mapmode Mode) {
799  this->Mode = Mode;
800  if (OrigFileHandle == INVALID_HANDLE_VALUE)
801    return make_error_code(errc::bad_file_descriptor);
802
803  DWORD flprotect;
804  switch (Mode) {
805  case readonly:  flprotect = PAGE_READONLY; break;
806  case readwrite: flprotect = PAGE_READWRITE; break;
807  case priv:      flprotect = PAGE_WRITECOPY; break;
808  }
809
810  HANDLE FileMappingHandle =
811      ::CreateFileMappingW(OrigFileHandle, 0, flprotect,
812                           Hi_32(Size),
813                           Lo_32(Size),
814                           0);
815  if (FileMappingHandle == NULL) {
816    std::error_code ec = mapWindowsError(GetLastError());
817    return ec;
818  }
819
820  DWORD dwDesiredAccess;
821  switch (Mode) {
822  case readonly:  dwDesiredAccess = FILE_MAP_READ; break;
823  case readwrite: dwDesiredAccess = FILE_MAP_WRITE; break;
824  case priv:      dwDesiredAccess = FILE_MAP_COPY; break;
825  }
826  Mapping = ::MapViewOfFile(FileMappingHandle,
827                            dwDesiredAccess,
828                            Offset >> 32,
829                            Offset & 0xffffffff,
830                            Size);
831  if (Mapping == NULL) {
832    std::error_code ec = mapWindowsError(GetLastError());
833    ::CloseHandle(FileMappingHandle);
834    return ec;
835  }
836
837  if (Size == 0) {
838    MEMORY_BASIC_INFORMATION mbi;
839    SIZE_T Result = VirtualQuery(Mapping, &mbi, sizeof(mbi));
840    if (Result == 0) {
841      std::error_code ec = mapWindowsError(GetLastError());
842      ::UnmapViewOfFile(Mapping);
843      ::CloseHandle(FileMappingHandle);
844      return ec;
845    }
846    Size = mbi.RegionSize;
847  }
848
849  // Close the file mapping handle, as it's kept alive by the file mapping. But
850  // neither the file mapping nor the file mapping handle keep the file handle
851  // alive, so we need to keep a reference to the file in case all other handles
852  // are closed and the file is deleted, which may cause invalid data to be read
853  // from the file.
854  ::CloseHandle(FileMappingHandle);
855  if (!::DuplicateHandle(::GetCurrentProcess(), OrigFileHandle,
856                         ::GetCurrentProcess(), &FileHandle, 0, 0,
857                         DUPLICATE_SAME_ACCESS)) {
858    std::error_code ec = mapWindowsError(GetLastError());
859    ::UnmapViewOfFile(Mapping);
860    return ec;
861  }
862
863  return std::error_code();
864}
865
866mapped_file_region::mapped_file_region(sys::fs::file_t fd, mapmode mode,
867                                       size_t length, uint64_t offset,
868                                       std::error_code &ec)
869    : Size(length), Mapping() {
870  ec = init(fd, offset, mode);
871  if (ec)
872    Mapping = 0;
873}
874
875static bool hasFlushBufferKernelBug() {
876  static bool Ret{GetWindowsOSVersion() < llvm::VersionTuple(10, 0, 0, 17763)};
877  return Ret;
878}
879
880static bool isEXE(StringRef Magic) {
881  static const char PEMagic[] = {'P', 'E', '\0', '\0'};
882  if (Magic.startswith(StringRef("MZ")) && Magic.size() >= 0x3c + 4) {
883    uint32_t off = read32le(Magic.data() + 0x3c);
884    // PE/COFF file, either EXE or DLL.
885    if (Magic.substr(off).startswith(StringRef(PEMagic, sizeof(PEMagic))))
886      return true;
887  }
888  return false;
889}
890
891mapped_file_region::~mapped_file_region() {
892  if (Mapping) {
893
894    bool Exe = isEXE(StringRef((char *)Mapping, Size));
895
896    ::UnmapViewOfFile(Mapping);
897
898    if (Mode == mapmode::readwrite && Exe && hasFlushBufferKernelBug()) {
899      // There is a Windows kernel bug, the exact trigger conditions of which
900      // are not well understood.  When triggered, dirty pages are not properly
901      // flushed and subsequent process's attempts to read a file can return
902      // invalid data.  Calling FlushFileBuffers on the write handle is
903      // sufficient to ensure that this bug is not triggered.
904      // The bug only occurs when writing an executable and executing it right
905      // after, under high I/O pressure.
906      ::FlushFileBuffers(FileHandle);
907    }
908
909    ::CloseHandle(FileHandle);
910  }
911}
912
913size_t mapped_file_region::size() const {
914  assert(Mapping && "Mapping failed but used anyway!");
915  return Size;
916}
917
918char *mapped_file_region::data() const {
919  assert(Mapping && "Mapping failed but used anyway!");
920  return reinterpret_cast<char*>(Mapping);
921}
922
923const char *mapped_file_region::const_data() const {
924  assert(Mapping && "Mapping failed but used anyway!");
925  return reinterpret_cast<const char*>(Mapping);
926}
927
928int mapped_file_region::alignment() {
929  SYSTEM_INFO SysInfo;
930  ::GetSystemInfo(&SysInfo);
931  return SysInfo.dwAllocationGranularity;
932}
933
934static basic_file_status status_from_find_data(WIN32_FIND_DATAW *FindData) {
935  return basic_file_status(file_type_from_attrs(FindData->dwFileAttributes),
936                           perms_from_attrs(FindData->dwFileAttributes),
937                           FindData->ftLastAccessTime.dwHighDateTime,
938                           FindData->ftLastAccessTime.dwLowDateTime,
939                           FindData->ftLastWriteTime.dwHighDateTime,
940                           FindData->ftLastWriteTime.dwLowDateTime,
941                           FindData->nFileSizeHigh, FindData->nFileSizeLow);
942}
943
944std::error_code detail::directory_iterator_construct(detail::DirIterState &IT,
945                                                     StringRef Path,
946                                                     bool FollowSymlinks) {
947  SmallVector<wchar_t, 128> PathUTF16;
948
949  if (std::error_code EC = widenPath(Path, PathUTF16))
950    return EC;
951
952  // Convert path to the format that Windows is happy with.
953  if (PathUTF16.size() > 0 &&
954      !is_separator(PathUTF16[Path.size() - 1]) &&
955      PathUTF16[Path.size() - 1] != L':') {
956    PathUTF16.push_back(L'\\');
957    PathUTF16.push_back(L'*');
958  } else {
959    PathUTF16.push_back(L'*');
960  }
961
962  //  Get the first directory entry.
963  WIN32_FIND_DATAW FirstFind;
964  ScopedFindHandle FindHandle(::FindFirstFileExW(
965      c_str(PathUTF16), FindExInfoBasic, &FirstFind, FindExSearchNameMatch,
966      NULL, FIND_FIRST_EX_LARGE_FETCH));
967  if (!FindHandle)
968    return mapWindowsError(::GetLastError());
969
970  size_t FilenameLen = ::wcslen(FirstFind.cFileName);
971  while ((FilenameLen == 1 && FirstFind.cFileName[0] == L'.') ||
972         (FilenameLen == 2 && FirstFind.cFileName[0] == L'.' &&
973                              FirstFind.cFileName[1] == L'.'))
974    if (!::FindNextFileW(FindHandle, &FirstFind)) {
975      DWORD LastError = ::GetLastError();
976      // Check for end.
977      if (LastError == ERROR_NO_MORE_FILES)
978        return detail::directory_iterator_destruct(IT);
979      return mapWindowsError(LastError);
980    } else
981      FilenameLen = ::wcslen(FirstFind.cFileName);
982
983  // Construct the current directory entry.
984  SmallString<128> DirectoryEntryNameUTF8;
985  if (std::error_code EC =
986          UTF16ToUTF8(FirstFind.cFileName, ::wcslen(FirstFind.cFileName),
987                      DirectoryEntryNameUTF8))
988    return EC;
989
990  IT.IterationHandle = intptr_t(FindHandle.take());
991  SmallString<128> DirectoryEntryPath(Path);
992  path::append(DirectoryEntryPath, DirectoryEntryNameUTF8);
993  IT.CurrentEntry =
994      directory_entry(DirectoryEntryPath, FollowSymlinks,
995                      file_type_from_attrs(FirstFind.dwFileAttributes),
996                      status_from_find_data(&FirstFind));
997
998  return std::error_code();
999}
1000
1001std::error_code detail::directory_iterator_destruct(detail::DirIterState &IT) {
1002  if (IT.IterationHandle != 0)
1003    // Closes the handle if it's valid.
1004    ScopedFindHandle close(HANDLE(IT.IterationHandle));
1005  IT.IterationHandle = 0;
1006  IT.CurrentEntry = directory_entry();
1007  return std::error_code();
1008}
1009
1010std::error_code detail::directory_iterator_increment(detail::DirIterState &IT) {
1011  WIN32_FIND_DATAW FindData;
1012  if (!::FindNextFileW(HANDLE(IT.IterationHandle), &FindData)) {
1013    DWORD LastError = ::GetLastError();
1014    // Check for end.
1015    if (LastError == ERROR_NO_MORE_FILES)
1016      return detail::directory_iterator_destruct(IT);
1017    return mapWindowsError(LastError);
1018  }
1019
1020  size_t FilenameLen = ::wcslen(FindData.cFileName);
1021  if ((FilenameLen == 1 && FindData.cFileName[0] == L'.') ||
1022      (FilenameLen == 2 && FindData.cFileName[0] == L'.' &&
1023                           FindData.cFileName[1] == L'.'))
1024    return directory_iterator_increment(IT);
1025
1026  SmallString<128> DirectoryEntryPathUTF8;
1027  if (std::error_code EC =
1028          UTF16ToUTF8(FindData.cFileName, ::wcslen(FindData.cFileName),
1029                      DirectoryEntryPathUTF8))
1030    return EC;
1031
1032  IT.CurrentEntry.replace_filename(
1033      Twine(DirectoryEntryPathUTF8),
1034      file_type_from_attrs(FindData.dwFileAttributes),
1035      status_from_find_data(&FindData));
1036  return std::error_code();
1037}
1038
1039ErrorOr<basic_file_status> directory_entry::status() const {
1040  return Status;
1041}
1042
1043static std::error_code nativeFileToFd(Expected<HANDLE> H, int &ResultFD,
1044                                      OpenFlags Flags) {
1045  int CrtOpenFlags = 0;
1046  if (Flags & OF_Append)
1047    CrtOpenFlags |= _O_APPEND;
1048
1049  if (Flags & OF_Text)
1050    CrtOpenFlags |= _O_TEXT;
1051
1052  ResultFD = -1;
1053  if (!H)
1054    return errorToErrorCode(H.takeError());
1055
1056  ResultFD = ::_open_osfhandle(intptr_t(*H), CrtOpenFlags);
1057  if (ResultFD == -1) {
1058    ::CloseHandle(*H);
1059    return mapWindowsError(ERROR_INVALID_HANDLE);
1060  }
1061  return std::error_code();
1062}
1063
1064static DWORD nativeDisposition(CreationDisposition Disp, OpenFlags Flags) {
1065  // This is a compatibility hack.  Really we should respect the creation
1066  // disposition, but a lot of old code relied on the implicit assumption that
1067  // OF_Append implied it would open an existing file.  Since the disposition is
1068  // now explicit and defaults to CD_CreateAlways, this assumption would cause
1069  // any usage of OF_Append to append to a new file, even if the file already
1070  // existed.  A better solution might have two new creation dispositions:
1071  // CD_AppendAlways and CD_AppendNew.  This would also address the problem of
1072  // OF_Append being used on a read-only descriptor, which doesn't make sense.
1073  if (Flags & OF_Append)
1074    return OPEN_ALWAYS;
1075
1076  switch (Disp) {
1077  case CD_CreateAlways:
1078    return CREATE_ALWAYS;
1079  case CD_CreateNew:
1080    return CREATE_NEW;
1081  case CD_OpenAlways:
1082    return OPEN_ALWAYS;
1083  case CD_OpenExisting:
1084    return OPEN_EXISTING;
1085  }
1086  llvm_unreachable("unreachable!");
1087}
1088
1089static DWORD nativeAccess(FileAccess Access, OpenFlags Flags) {
1090  DWORD Result = 0;
1091  if (Access & FA_Read)
1092    Result |= GENERIC_READ;
1093  if (Access & FA_Write)
1094    Result |= GENERIC_WRITE;
1095  if (Flags & OF_Delete)
1096    Result |= DELETE;
1097  if (Flags & OF_UpdateAtime)
1098    Result |= FILE_WRITE_ATTRIBUTES;
1099  return Result;
1100}
1101
1102static std::error_code openNativeFileInternal(const Twine &Name,
1103                                              file_t &ResultFile, DWORD Disp,
1104                                              DWORD Access, DWORD Flags,
1105                                              bool Inherit = false) {
1106  SmallVector<wchar_t, 128> PathUTF16;
1107  if (std::error_code EC = widenPath(Name, PathUTF16))
1108    return EC;
1109
1110  SECURITY_ATTRIBUTES SA;
1111  SA.nLength = sizeof(SA);
1112  SA.lpSecurityDescriptor = nullptr;
1113  SA.bInheritHandle = Inherit;
1114
1115  HANDLE H =
1116      ::CreateFileW(PathUTF16.begin(), Access,
1117                    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, &SA,
1118                    Disp, Flags, NULL);
1119  if (H == INVALID_HANDLE_VALUE) {
1120    DWORD LastError = ::GetLastError();
1121    std::error_code EC = mapWindowsError(LastError);
1122    // Provide a better error message when trying to open directories.
1123    // This only runs if we failed to open the file, so there is probably
1124    // no performances issues.
1125    if (LastError != ERROR_ACCESS_DENIED)
1126      return EC;
1127    if (is_directory(Name))
1128      return make_error_code(errc::is_a_directory);
1129    return EC;
1130  }
1131  ResultFile = H;
1132  return std::error_code();
1133}
1134
1135Expected<file_t> openNativeFile(const Twine &Name, CreationDisposition Disp,
1136                                FileAccess Access, OpenFlags Flags,
1137                                unsigned Mode) {
1138  // Verify that we don't have both "append" and "excl".
1139  assert((!(Disp == CD_CreateNew) || !(Flags & OF_Append)) &&
1140         "Cannot specify both 'CreateNew' and 'Append' file creation flags!");
1141
1142  DWORD NativeDisp = nativeDisposition(Disp, Flags);
1143  DWORD NativeAccess = nativeAccess(Access, Flags);
1144
1145  bool Inherit = false;
1146  if (Flags & OF_ChildInherit)
1147    Inherit = true;
1148
1149  file_t Result;
1150  std::error_code EC = openNativeFileInternal(
1151      Name, Result, NativeDisp, NativeAccess, FILE_ATTRIBUTE_NORMAL, Inherit);
1152  if (EC)
1153    return errorCodeToError(EC);
1154
1155  if (Flags & OF_UpdateAtime) {
1156    FILETIME FileTime;
1157    SYSTEMTIME SystemTime;
1158    GetSystemTime(&SystemTime);
1159    if (SystemTimeToFileTime(&SystemTime, &FileTime) == 0 ||
1160        SetFileTime(Result, NULL, &FileTime, NULL) == 0) {
1161      DWORD LastError = ::GetLastError();
1162      ::CloseHandle(Result);
1163      return errorCodeToError(mapWindowsError(LastError));
1164    }
1165  }
1166
1167  if (Flags & OF_Delete) {
1168    if ((EC = setDeleteDisposition(Result, true))) {
1169      ::CloseHandle(Result);
1170      return errorCodeToError(EC);
1171    }
1172  }
1173  return Result;
1174}
1175
1176std::error_code openFile(const Twine &Name, int &ResultFD,
1177                         CreationDisposition Disp, FileAccess Access,
1178                         OpenFlags Flags, unsigned int Mode) {
1179  Expected<file_t> Result = openNativeFile(Name, Disp, Access, Flags);
1180  if (!Result)
1181    return errorToErrorCode(Result.takeError());
1182
1183  return nativeFileToFd(*Result, ResultFD, Flags);
1184}
1185
1186static std::error_code directoryRealPath(const Twine &Name,
1187                                         SmallVectorImpl<char> &RealPath) {
1188  file_t File;
1189  std::error_code EC = openNativeFileInternal(
1190      Name, File, OPEN_EXISTING, GENERIC_READ, FILE_FLAG_BACKUP_SEMANTICS);
1191  if (EC)
1192    return EC;
1193
1194  EC = realPathFromHandle(File, RealPath);
1195  ::CloseHandle(File);
1196  return EC;
1197}
1198
1199std::error_code openFileForRead(const Twine &Name, int &ResultFD,
1200                                OpenFlags Flags,
1201                                SmallVectorImpl<char> *RealPath) {
1202  Expected<HANDLE> NativeFile = openNativeFileForRead(Name, Flags, RealPath);
1203  return nativeFileToFd(std::move(NativeFile), ResultFD, OF_None);
1204}
1205
1206Expected<file_t> openNativeFileForRead(const Twine &Name, OpenFlags Flags,
1207                                       SmallVectorImpl<char> *RealPath) {
1208  Expected<file_t> Result =
1209      openNativeFile(Name, CD_OpenExisting, FA_Read, Flags);
1210
1211  // Fetch the real name of the file, if the user asked
1212  if (Result && RealPath)
1213    realPathFromHandle(*Result, *RealPath);
1214
1215  return Result;
1216}
1217
1218file_t convertFDToNativeFile(int FD) {
1219  return reinterpret_cast<HANDLE>(::_get_osfhandle(FD));
1220}
1221
1222file_t getStdinHandle() { return ::GetStdHandle(STD_INPUT_HANDLE); }
1223file_t getStdoutHandle() { return ::GetStdHandle(STD_OUTPUT_HANDLE); }
1224file_t getStderrHandle() { return ::GetStdHandle(STD_ERROR_HANDLE); }
1225
1226Expected<size_t> readNativeFileImpl(file_t FileHandle,
1227                                    MutableArrayRef<char> Buf,
1228                                    OVERLAPPED *Overlap) {
1229  // ReadFile can only read 2GB at a time. The caller should check the number of
1230  // bytes and read in a loop until termination.
1231  DWORD BytesToRead =
1232      std::min(size_t(std::numeric_limits<DWORD>::max()), Buf.size());
1233  DWORD BytesRead = 0;
1234  if (::ReadFile(FileHandle, Buf.data(), BytesToRead, &BytesRead, Overlap))
1235    return BytesRead;
1236  DWORD Err = ::GetLastError();
1237  // EOF is not an error.
1238  if (Err == ERROR_BROKEN_PIPE || Err == ERROR_HANDLE_EOF)
1239    return BytesRead;
1240  return errorCodeToError(mapWindowsError(Err));
1241}
1242
1243Expected<size_t> readNativeFile(file_t FileHandle, MutableArrayRef<char> Buf) {
1244  return readNativeFileImpl(FileHandle, Buf, /*Overlap=*/nullptr);
1245}
1246
1247Expected<size_t> readNativeFileSlice(file_t FileHandle,
1248                                     MutableArrayRef<char> Buf,
1249                                     uint64_t Offset) {
1250  OVERLAPPED Overlapped = {};
1251  Overlapped.Offset = uint32_t(Offset);
1252  Overlapped.OffsetHigh = uint32_t(Offset >> 32);
1253  return readNativeFileImpl(FileHandle, Buf, &Overlapped);
1254}
1255
1256std::error_code closeFile(file_t &F) {
1257  file_t TmpF = F;
1258  F = kInvalidFile;
1259  if (!::CloseHandle(TmpF))
1260    return mapWindowsError(::GetLastError());
1261  return std::error_code();
1262}
1263
1264std::error_code remove_directories(const Twine &path, bool IgnoreErrors) {
1265  // Convert to utf-16.
1266  SmallVector<wchar_t, 128> Path16;
1267  std::error_code EC = widenPath(path, Path16);
1268  if (EC && !IgnoreErrors)
1269    return EC;
1270
1271  // SHFileOperation() accepts a list of paths, and so must be double null-
1272  // terminated to indicate the end of the list.  The buffer is already null
1273  // terminated, but since that null character is not considered part of the
1274  // vector's size, pushing another one will just consume that byte.  So we
1275  // need to push 2 null terminators.
1276  Path16.push_back(0);
1277  Path16.push_back(0);
1278
1279  SHFILEOPSTRUCTW shfos = {};
1280  shfos.wFunc = FO_DELETE;
1281  shfos.pFrom = Path16.data();
1282  shfos.fFlags = FOF_NO_UI;
1283
1284  int result = ::SHFileOperationW(&shfos);
1285  if (result != 0 && !IgnoreErrors)
1286    return mapWindowsError(result);
1287  return std::error_code();
1288}
1289
1290static void expandTildeExpr(SmallVectorImpl<char> &Path) {
1291  // Path does not begin with a tilde expression.
1292  if (Path.empty() || Path[0] != '~')
1293    return;
1294
1295  StringRef PathStr(Path.begin(), Path.size());
1296  PathStr = PathStr.drop_front();
1297  StringRef Expr = PathStr.take_until([](char c) { return path::is_separator(c); });
1298
1299  if (!Expr.empty()) {
1300    // This is probably a ~username/ expression.  Don't support this on Windows.
1301    return;
1302  }
1303
1304  SmallString<128> HomeDir;
1305  if (!path::home_directory(HomeDir)) {
1306    // For some reason we couldn't get the home directory.  Just exit.
1307    return;
1308  }
1309
1310  // Overwrite the first character and insert the rest.
1311  Path[0] = HomeDir[0];
1312  Path.insert(Path.begin() + 1, HomeDir.begin() + 1, HomeDir.end());
1313}
1314
1315void expand_tilde(const Twine &path, SmallVectorImpl<char> &dest) {
1316  dest.clear();
1317  if (path.isTriviallyEmpty())
1318    return;
1319
1320  path.toVector(dest);
1321  expandTildeExpr(dest);
1322
1323  return;
1324}
1325
1326std::error_code real_path(const Twine &path, SmallVectorImpl<char> &dest,
1327                          bool expand_tilde) {
1328  dest.clear();
1329  if (path.isTriviallyEmpty())
1330    return std::error_code();
1331
1332  if (expand_tilde) {
1333    SmallString<128> Storage;
1334    path.toVector(Storage);
1335    expandTildeExpr(Storage);
1336    return real_path(Storage, dest, false);
1337  }
1338
1339  if (is_directory(path))
1340    return directoryRealPath(path, dest);
1341
1342  int fd;
1343  if (std::error_code EC =
1344          llvm::sys::fs::openFileForRead(path, fd, OF_None, &dest))
1345    return EC;
1346  ::close(fd);
1347  return std::error_code();
1348}
1349
1350} // end namespace fs
1351
1352namespace path {
1353static bool getKnownFolderPath(KNOWNFOLDERID folderId,
1354                               SmallVectorImpl<char> &result) {
1355  wchar_t *path = nullptr;
1356  if (::SHGetKnownFolderPath(folderId, KF_FLAG_CREATE, nullptr, &path) != S_OK)
1357    return false;
1358
1359  bool ok = !UTF16ToUTF8(path, ::wcslen(path), result);
1360  ::CoTaskMemFree(path);
1361  return ok;
1362}
1363
1364bool home_directory(SmallVectorImpl<char> &result) {
1365  return getKnownFolderPath(FOLDERID_Profile, result);
1366}
1367
1368static bool getTempDirEnvVar(const wchar_t *Var, SmallVectorImpl<char> &Res) {
1369  SmallVector<wchar_t, 1024> Buf;
1370  size_t Size = 1024;
1371  do {
1372    Buf.reserve(Size);
1373    Size = GetEnvironmentVariableW(Var, Buf.data(), Buf.capacity());
1374    if (Size == 0)
1375      return false;
1376
1377    // Try again with larger buffer.
1378  } while (Size > Buf.capacity());
1379  Buf.set_size(Size);
1380
1381  return !windows::UTF16ToUTF8(Buf.data(), Size, Res);
1382}
1383
1384static bool getTempDirEnvVar(SmallVectorImpl<char> &Res) {
1385  const wchar_t *EnvironmentVariables[] = {L"TMP", L"TEMP", L"USERPROFILE"};
1386  for (auto *Env : EnvironmentVariables) {
1387    if (getTempDirEnvVar(Env, Res))
1388      return true;
1389  }
1390  return false;
1391}
1392
1393void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) {
1394  (void)ErasedOnReboot;
1395  Result.clear();
1396
1397  // Check whether the temporary directory is specified by an environment var.
1398  // This matches GetTempPath logic to some degree. GetTempPath is not used
1399  // directly as it cannot handle evn var longer than 130 chars on Windows 7
1400  // (fixed on Windows 8).
1401  if (getTempDirEnvVar(Result)) {
1402    assert(!Result.empty() && "Unexpected empty path");
1403    native(Result); // Some Unix-like shells use Unix path separator in $TMP.
1404    fs::make_absolute(Result); // Make it absolute if not already.
1405    return;
1406  }
1407
1408  // Fall back to a system default.
1409  const char *DefaultResult = "C:\\Temp";
1410  Result.append(DefaultResult, DefaultResult + strlen(DefaultResult));
1411}
1412} // end namespace path
1413
1414namespace windows {
1415std::error_code CodePageToUTF16(unsigned codepage,
1416                                llvm::StringRef original,
1417                                llvm::SmallVectorImpl<wchar_t> &utf16) {
1418  if (!original.empty()) {
1419    int len = ::MultiByteToWideChar(codepage, MB_ERR_INVALID_CHARS, original.begin(),
1420                                    original.size(), utf16.begin(), 0);
1421
1422    if (len == 0) {
1423      return mapWindowsError(::GetLastError());
1424    }
1425
1426    utf16.reserve(len + 1);
1427    utf16.set_size(len);
1428
1429    len = ::MultiByteToWideChar(codepage, MB_ERR_INVALID_CHARS, original.begin(),
1430                                original.size(), utf16.begin(), utf16.size());
1431
1432    if (len == 0) {
1433      return mapWindowsError(::GetLastError());
1434    }
1435  }
1436
1437  // Make utf16 null terminated.
1438  utf16.push_back(0);
1439  utf16.pop_back();
1440
1441  return std::error_code();
1442}
1443
1444std::error_code UTF8ToUTF16(llvm::StringRef utf8,
1445                            llvm::SmallVectorImpl<wchar_t> &utf16) {
1446  return CodePageToUTF16(CP_UTF8, utf8, utf16);
1447}
1448
1449std::error_code CurCPToUTF16(llvm::StringRef curcp,
1450                            llvm::SmallVectorImpl<wchar_t> &utf16) {
1451  return CodePageToUTF16(CP_ACP, curcp, utf16);
1452}
1453
1454static
1455std::error_code UTF16ToCodePage(unsigned codepage, const wchar_t *utf16,
1456                                size_t utf16_len,
1457                                llvm::SmallVectorImpl<char> &converted) {
1458  if (utf16_len) {
1459    // Get length.
1460    int len = ::WideCharToMultiByte(codepage, 0, utf16, utf16_len, converted.begin(),
1461                                    0, NULL, NULL);
1462
1463    if (len == 0) {
1464      return mapWindowsError(::GetLastError());
1465    }
1466
1467    converted.reserve(len);
1468    converted.set_size(len);
1469
1470    // Now do the actual conversion.
1471    len = ::WideCharToMultiByte(codepage, 0, utf16, utf16_len, converted.data(),
1472                                converted.size(), NULL, NULL);
1473
1474    if (len == 0) {
1475      return mapWindowsError(::GetLastError());
1476    }
1477  }
1478
1479  // Make the new string null terminated.
1480  converted.push_back(0);
1481  converted.pop_back();
1482
1483  return std::error_code();
1484}
1485
1486std::error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len,
1487                            llvm::SmallVectorImpl<char> &utf8) {
1488  return UTF16ToCodePage(CP_UTF8, utf16, utf16_len, utf8);
1489}
1490
1491std::error_code UTF16ToCurCP(const wchar_t *utf16, size_t utf16_len,
1492                             llvm::SmallVectorImpl<char> &curcp) {
1493  return UTF16ToCodePage(CP_ACP, utf16, utf16_len, curcp);
1494}
1495
1496} // end namespace windows
1497} // end namespace sys
1498} // end namespace llvm
1499