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 <sys/stat.h>
23#include <sys/types.h>
24
25// These two headers must be included last, and make sure shlobj is required
26// after Windows.h to make sure it picks up our definition of _WIN32_WINNT
27#include "llvm/Support/Windows/WindowsSupport.h"
28#include <shellapi.h>
29#include <shlobj.h>
30
31#undef max
32
33// MinGW doesn't define this.
34#ifndef _ERRNO_T_DEFINED
35#define _ERRNO_T_DEFINED
36typedef int errno_t;
37#endif
38
39#ifdef _MSC_VER
40# pragma comment(lib, "advapi32.lib")  // This provides CryptAcquireContextW.
41# pragma comment(lib, "ole32.lib")     // This provides CoTaskMemFree
42#endif
43
44using namespace llvm;
45
46using llvm::sys::windows::UTF8ToUTF16;
47using llvm::sys::windows::CurCPToUTF16;
48using llvm::sys::windows::UTF16ToUTF8;
49using llvm::sys::windows::widenPath;
50
51static bool is_separator(const wchar_t value) {
52  switch (value) {
53  case L'\\':
54  case L'/':
55    return true;
56  default:
57    return false;
58  }
59}
60
61namespace llvm {
62namespace sys  {
63namespace windows {
64
65// Convert a UTF-8 path to UTF-16. Also, if the absolute equivalent of the path
66// is longer than the limit that the Win32 Unicode File API can tolerate, make
67// it an absolute normalized path prefixed by '\\?\'.
68std::error_code widenPath(const Twine &Path8, SmallVectorImpl<wchar_t> &Path16,
69                          size_t MaxPathLen) {
70  assert(MaxPathLen <= MAX_PATH);
71
72  // Several operations would convert Path8 to SmallString; more efficient to do
73  // it once up front.
74  SmallString<MAX_PATH> Path8Str;
75  Path8.toVector(Path8Str);
76
77  if (std::error_code EC = UTF8ToUTF16(Path8Str, Path16))
78    return EC;
79
80  const bool IsAbsolute = llvm::sys::path::is_absolute(Path8);
81  size_t CurPathLen;
82  if (IsAbsolute)
83    CurPathLen = 0; // No contribution from current_path needed.
84  else {
85    CurPathLen = ::GetCurrentDirectoryW(
86        0, NULL); // Returns the size including the null terminator.
87    if (CurPathLen == 0)
88      return mapWindowsError(::GetLastError());
89  }
90
91  const char *const LongPathPrefix = "\\\\?\\";
92
93  if ((Path16.size() + CurPathLen) < MaxPathLen ||
94      Path8Str.startswith(LongPathPrefix))
95    return std::error_code();
96
97  if (!IsAbsolute) {
98    if (std::error_code EC = llvm::sys::fs::make_absolute(Path8Str))
99      return EC;
100  }
101
102  // Remove '.' and '..' because long paths treat these as real path components.
103  llvm::sys::path::native(Path8Str, path::Style::windows);
104  llvm::sys::path::remove_dots(Path8Str, true);
105
106  const StringRef RootName = llvm::sys::path::root_name(Path8Str);
107  assert(!RootName.empty() &&
108         "Root name cannot be empty for an absolute path!");
109
110  SmallString<2 * MAX_PATH> FullPath(LongPathPrefix);
111  if (RootName[1] != ':') { // Check if UNC.
112    FullPath.append("UNC\\");
113    FullPath.append(Path8Str.begin() + 2, Path8Str.end());
114  } else
115    FullPath.append(Path8Str);
116
117  return UTF8ToUTF16(FullPath, Path16);
118}
119
120} // end namespace windows
121
122namespace fs {
123
124const file_t kInvalidFile = INVALID_HANDLE_VALUE;
125
126std::string getMainExecutable(const char *argv0, void *MainExecAddr) {
127  SmallVector<wchar_t, MAX_PATH> PathName;
128  DWORD Size = ::GetModuleFileNameW(NULL, PathName.data(), PathName.capacity());
129
130  // A zero return value indicates a failure other than insufficient space.
131  if (Size == 0)
132    return "";
133
134  // Insufficient space is determined by a return value equal to the size of
135  // the buffer passed in.
136  if (Size == PathName.capacity())
137    return "";
138
139  // On success, GetModuleFileNameW returns the number of characters written to
140  // the buffer not including the NULL terminator.
141  PathName.set_size(Size);
142
143  // Convert the result from UTF-16 to UTF-8.
144  SmallVector<char, MAX_PATH> PathNameUTF8;
145  if (UTF16ToUTF8(PathName.data(), PathName.size(), PathNameUTF8))
146    return "";
147
148  return std::string(PathNameUTF8.data());
149}
150
151UniqueID file_status::getUniqueID() const {
152  // The file is uniquely identified by the volume serial number along
153  // with the 64-bit file identifier.
154  uint64_t FileID = (static_cast<uint64_t>(FileIndexHigh) << 32ULL) |
155                    static_cast<uint64_t>(FileIndexLow);
156
157  return UniqueID(VolumeSerialNumber, FileID);
158}
159
160ErrorOr<space_info> disk_space(const Twine &Path) {
161  ULARGE_INTEGER Avail, Total, Free;
162  if (!::GetDiskFreeSpaceExA(Path.str().c_str(), &Avail, &Total, &Free))
163    return mapWindowsError(::GetLastError());
164  space_info SpaceInfo;
165  SpaceInfo.capacity =
166      (static_cast<uint64_t>(Total.HighPart) << 32) + Total.LowPart;
167  SpaceInfo.free = (static_cast<uint64_t>(Free.HighPart) << 32) + Free.LowPart;
168  SpaceInfo.available =
169      (static_cast<uint64_t>(Avail.HighPart) << 32) + Avail.LowPart;
170  return SpaceInfo;
171}
172
173TimePoint<> basic_file_status::getLastAccessedTime() const {
174  FILETIME Time;
175  Time.dwLowDateTime = LastAccessedTimeLow;
176  Time.dwHighDateTime = LastAccessedTimeHigh;
177  return toTimePoint(Time);
178}
179
180TimePoint<> basic_file_status::getLastModificationTime() const {
181  FILETIME Time;
182  Time.dwLowDateTime = LastWriteTimeLow;
183  Time.dwHighDateTime = LastWriteTimeHigh;
184  return toTimePoint(Time);
185}
186
187uint32_t file_status::getLinkCount() const {
188  return NumLinks;
189}
190
191std::error_code current_path(SmallVectorImpl<char> &result) {
192  SmallVector<wchar_t, MAX_PATH> cur_path;
193  DWORD len = MAX_PATH;
194
195  do {
196    cur_path.reserve(len);
197    len = ::GetCurrentDirectoryW(cur_path.capacity(), cur_path.data());
198
199    // A zero return value indicates a failure other than insufficient space.
200    if (len == 0)
201      return mapWindowsError(::GetLastError());
202
203    // If there's insufficient space, the len returned is larger than the len
204    // given.
205  } while (len > cur_path.capacity());
206
207  // On success, GetCurrentDirectoryW returns the number of characters not
208  // including the null-terminator.
209  cur_path.set_size(len);
210  return UTF16ToUTF8(cur_path.begin(), cur_path.size(), result);
211}
212
213std::error_code set_current_path(const Twine &path) {
214  // Convert to utf-16.
215  SmallVector<wchar_t, 128> wide_path;
216  if (std::error_code ec = widenPath(path, wide_path))
217    return ec;
218
219  if (!::SetCurrentDirectoryW(wide_path.begin()))
220    return mapWindowsError(::GetLastError());
221
222  return std::error_code();
223}
224
225std::error_code create_directory(const Twine &path, bool IgnoreExisting,
226                                 perms Perms) {
227  SmallVector<wchar_t, 128> path_utf16;
228
229  // CreateDirectoryW has a lower maximum path length as it must leave room for
230  // an 8.3 filename.
231  if (std::error_code ec = widenPath(path, path_utf16, MAX_PATH - 12))
232    return ec;
233
234  if (!::CreateDirectoryW(path_utf16.begin(), NULL)) {
235    DWORD LastError = ::GetLastError();
236    if (LastError != ERROR_ALREADY_EXISTS || !IgnoreExisting)
237      return mapWindowsError(LastError);
238  }
239
240  return std::error_code();
241}
242
243// We can't use symbolic links for windows.
244std::error_code create_link(const Twine &to, const Twine &from) {
245  // Convert to utf-16.
246  SmallVector<wchar_t, 128> wide_from;
247  SmallVector<wchar_t, 128> wide_to;
248  if (std::error_code ec = widenPath(from, wide_from))
249    return ec;
250  if (std::error_code ec = widenPath(to, wide_to))
251    return ec;
252
253  if (!::CreateHardLinkW(wide_from.begin(), wide_to.begin(), NULL))
254    return mapWindowsError(::GetLastError());
255
256  return std::error_code();
257}
258
259std::error_code create_hard_link(const Twine &to, const Twine &from) {
260  return create_link(to, from);
261}
262
263std::error_code remove(const Twine &path, bool IgnoreNonExisting) {
264  SmallVector<wchar_t, 128> path_utf16;
265
266  if (std::error_code ec = widenPath(path, path_utf16))
267    return ec;
268
269  // We don't know whether this is a file or a directory, and remove() can
270  // accept both. The usual way to delete a file or directory is to use one of
271  // the DeleteFile or RemoveDirectory functions, but that requires you to know
272  // which one it is. We could stat() the file to determine that, but that would
273  // cost us additional system calls, which can be slow in a directory
274  // containing a large number of files. So instead we call CreateFile directly.
275  // The important part is the FILE_FLAG_DELETE_ON_CLOSE flag, which causes the
276  // file to be deleted once it is closed. We also use the flags
277  // FILE_FLAG_BACKUP_SEMANTICS (which allows us to open directories), and
278  // FILE_FLAG_OPEN_REPARSE_POINT (don't follow symlinks).
279  ScopedFileHandle h(::CreateFileW(
280      c_str(path_utf16), DELETE,
281      FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
282      OPEN_EXISTING,
283      FILE_ATTRIBUTE_NORMAL | FILE_FLAG_BACKUP_SEMANTICS |
284          FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_DELETE_ON_CLOSE,
285      NULL));
286  if (!h) {
287    std::error_code EC = mapWindowsError(::GetLastError());
288    if (EC != errc::no_such_file_or_directory || !IgnoreNonExisting)
289      return EC;
290  }
291
292  return std::error_code();
293}
294
295static std::error_code is_local_internal(SmallVectorImpl<wchar_t> &Path,
296                                         bool &Result) {
297  SmallVector<wchar_t, 128> VolumePath;
298  size_t Len = 128;
299  while (true) {
300    VolumePath.resize(Len);
301    BOOL Success =
302        ::GetVolumePathNameW(Path.data(), VolumePath.data(), VolumePath.size());
303
304    if (Success)
305      break;
306
307    DWORD Err = ::GetLastError();
308    if (Err != ERROR_INSUFFICIENT_BUFFER)
309      return mapWindowsError(Err);
310
311    Len *= 2;
312  }
313  // If the output buffer has exactly enough space for the path name, but not
314  // the null terminator, it will leave the output unterminated.  Push a null
315  // terminator onto the end to ensure that this never happens.
316  VolumePath.push_back(L'\0');
317  VolumePath.set_size(wcslen(VolumePath.data()));
318  const wchar_t *P = VolumePath.data();
319
320  UINT Type = ::GetDriveTypeW(P);
321  switch (Type) {
322  case DRIVE_FIXED:
323    Result = true;
324    return std::error_code();
325  case DRIVE_REMOTE:
326  case DRIVE_CDROM:
327  case DRIVE_RAMDISK:
328  case DRIVE_REMOVABLE:
329    Result = false;
330    return std::error_code();
331  default:
332    return make_error_code(errc::no_such_file_or_directory);
333  }
334  llvm_unreachable("Unreachable!");
335}
336
337std::error_code is_local(const Twine &path, bool &result) {
338  if (!llvm::sys::fs::exists(path) || !llvm::sys::path::has_root_path(path))
339    return make_error_code(errc::no_such_file_or_directory);
340
341  SmallString<128> Storage;
342  StringRef P = path.toStringRef(Storage);
343
344  // Convert to utf-16.
345  SmallVector<wchar_t, 128> WidePath;
346  if (std::error_code ec = widenPath(P, WidePath))
347    return ec;
348  return is_local_internal(WidePath, result);
349}
350
351static std::error_code realPathFromHandle(HANDLE H,
352                                          SmallVectorImpl<wchar_t> &Buffer) {
353  DWORD CountChars = ::GetFinalPathNameByHandleW(
354      H, Buffer.begin(), Buffer.capacity(), FILE_NAME_NORMALIZED);
355  if (CountChars && CountChars >= Buffer.capacity()) {
356    // The buffer wasn't big enough, try again.  In this case the return value
357    // *does* indicate the size of the null terminator.
358    Buffer.reserve(CountChars);
359    CountChars = ::GetFinalPathNameByHandleW(
360        H, Buffer.begin(), Buffer.capacity(), FILE_NAME_NORMALIZED);
361  }
362  if (CountChars == 0)
363    return mapWindowsError(GetLastError());
364  Buffer.set_size(CountChars);
365  return std::error_code();
366}
367
368static std::error_code realPathFromHandle(HANDLE H,
369                                          SmallVectorImpl<char> &RealPath) {
370  RealPath.clear();
371  SmallVector<wchar_t, MAX_PATH> Buffer;
372  if (std::error_code EC = realPathFromHandle(H, Buffer))
373    return EC;
374
375  // Strip the \\?\ prefix. We don't want it ending up in output, and such
376  // paths don't get canonicalized by file APIs.
377  wchar_t *Data = Buffer.data();
378  DWORD CountChars = Buffer.size();
379  if (CountChars >= 8 && ::memcmp(Data, L"\\\\?\\UNC\\", 16) == 0) {
380    // Convert \\?\UNC\foo\bar to \\foo\bar
381    CountChars -= 6;
382    Data += 6;
383    Data[0] = '\\';
384  } else if (CountChars >= 4 && ::memcmp(Data, L"\\\\?\\", 8) == 0) {
385    // Convert \\?\c:\foo to c:\foo
386    CountChars -= 4;
387    Data += 4;
388  }
389
390  // Convert the result from UTF-16 to UTF-8.
391  return UTF16ToUTF8(Data, CountChars, RealPath);
392}
393
394std::error_code is_local(int FD, bool &Result) {
395  SmallVector<wchar_t, 128> FinalPath;
396  HANDLE Handle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
397
398  if (std::error_code EC = realPathFromHandle(Handle, FinalPath))
399    return EC;
400
401  return is_local_internal(FinalPath, Result);
402}
403
404static std::error_code setDeleteDisposition(HANDLE Handle, bool Delete) {
405  // Clear the FILE_DISPOSITION_INFO flag first, before checking if it's a
406  // network file. On Windows 7 the function realPathFromHandle() below fails
407  // if the FILE_DISPOSITION_INFO flag was already set to 'DeleteFile = true' by
408  // a prior call.
409  FILE_DISPOSITION_INFO Disposition;
410  Disposition.DeleteFile = false;
411  if (!SetFileInformationByHandle(Handle, FileDispositionInfo, &Disposition,
412                                  sizeof(Disposition)))
413    return mapWindowsError(::GetLastError());
414  if (!Delete)
415    return std::error_code();
416
417  // Check if the file is on a network (non-local) drive. If so, don't
418  // continue when DeleteFile is true, since it prevents opening the file for
419  // writes. Note -- this will leak temporary files on disk, but only when the
420  // target file is on a network drive.
421  SmallVector<wchar_t, 128> FinalPath;
422  if (std::error_code EC = realPathFromHandle(Handle, FinalPath))
423    return EC;
424
425  bool IsLocal;
426  if (std::error_code EC = is_local_internal(FinalPath, IsLocal))
427    return EC;
428
429  if (!IsLocal)
430    return std::error_code();
431
432  // The file is on a local drive, we can safely set FILE_DISPOSITION_INFO's
433  // flag.
434  Disposition.DeleteFile = true;
435  if (!SetFileInformationByHandle(Handle, FileDispositionInfo, &Disposition,
436                                  sizeof(Disposition)))
437    return mapWindowsError(::GetLastError());
438  return std::error_code();
439}
440
441static std::error_code rename_internal(HANDLE FromHandle, const Twine &To,
442                                       bool ReplaceIfExists) {
443  SmallVector<wchar_t, 0> ToWide;
444  if (auto EC = widenPath(To, ToWide))
445    return EC;
446
447  std::vector<char> RenameInfoBuf(sizeof(FILE_RENAME_INFO) - sizeof(wchar_t) +
448                                  (ToWide.size() * sizeof(wchar_t)));
449  FILE_RENAME_INFO &RenameInfo =
450      *reinterpret_cast<FILE_RENAME_INFO *>(RenameInfoBuf.data());
451  RenameInfo.ReplaceIfExists = ReplaceIfExists;
452  RenameInfo.RootDirectory = 0;
453  RenameInfo.FileNameLength = ToWide.size() * sizeof(wchar_t);
454  std::copy(ToWide.begin(), ToWide.end(), &RenameInfo.FileName[0]);
455
456  SetLastError(ERROR_SUCCESS);
457  if (!SetFileInformationByHandle(FromHandle, FileRenameInfo, &RenameInfo,
458                                  RenameInfoBuf.size())) {
459    unsigned Error = GetLastError();
460    if (Error == ERROR_SUCCESS)
461      Error = ERROR_CALL_NOT_IMPLEMENTED; // Wine doesn't always set error code.
462    return mapWindowsError(Error);
463  }
464
465  return std::error_code();
466}
467
468static std::error_code rename_handle(HANDLE FromHandle, const Twine &To) {
469  SmallVector<wchar_t, 128> WideTo;
470  if (std::error_code EC = widenPath(To, WideTo))
471    return EC;
472
473  // We normally expect this loop to succeed after a few iterations. If it
474  // requires more than 200 tries, it's more likely that the failures are due to
475  // a true error, so stop trying.
476  for (unsigned Retry = 0; Retry != 200; ++Retry) {
477    auto EC = rename_internal(FromHandle, To, true);
478
479    if (EC ==
480        std::error_code(ERROR_CALL_NOT_IMPLEMENTED, std::system_category())) {
481      // Wine doesn't support SetFileInformationByHandle in rename_internal.
482      // Fall back to MoveFileEx.
483      SmallVector<wchar_t, MAX_PATH> WideFrom;
484      if (std::error_code EC2 = realPathFromHandle(FromHandle, WideFrom))
485        return EC2;
486      if (::MoveFileExW(WideFrom.begin(), WideTo.begin(),
487                        MOVEFILE_REPLACE_EXISTING))
488        return std::error_code();
489      return mapWindowsError(GetLastError());
490    }
491
492    if (!EC || EC != errc::permission_denied)
493      return EC;
494
495    // The destination file probably exists and is currently open in another
496    // process, either because the file was opened without FILE_SHARE_DELETE or
497    // it is mapped into memory (e.g. using MemoryBuffer). Rename it in order to
498    // move it out of the way of the source file. Use FILE_FLAG_DELETE_ON_CLOSE
499    // to arrange for the destination file to be deleted when the other process
500    // closes it.
501    ScopedFileHandle ToHandle(
502        ::CreateFileW(WideTo.begin(), GENERIC_READ | DELETE,
503                      FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
504                      NULL, OPEN_EXISTING,
505                      FILE_ATTRIBUTE_NORMAL | FILE_FLAG_DELETE_ON_CLOSE, NULL));
506    if (!ToHandle) {
507      auto EC = mapWindowsError(GetLastError());
508      // Another process might have raced with us and moved the existing file
509      // out of the way before we had a chance to open it. If that happens, try
510      // to rename the source file again.
511      if (EC == errc::no_such_file_or_directory)
512        continue;
513      return EC;
514    }
515
516    BY_HANDLE_FILE_INFORMATION FI;
517    if (!GetFileInformationByHandle(ToHandle, &FI))
518      return mapWindowsError(GetLastError());
519
520    // Try to find a unique new name for the destination file.
521    for (unsigned UniqueId = 0; UniqueId != 200; ++UniqueId) {
522      std::string TmpFilename = (To + ".tmp" + utostr(UniqueId)).str();
523      if (auto EC = rename_internal(ToHandle, TmpFilename, false)) {
524        if (EC == errc::file_exists || EC == errc::permission_denied) {
525          // Again, another process might have raced with us and moved the file
526          // before we could move it. Check whether this is the case, as it
527          // might have caused the permission denied error. If that was the
528          // case, we don't need to move it ourselves.
529          ScopedFileHandle ToHandle2(::CreateFileW(
530              WideTo.begin(), 0,
531              FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
532              OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL));
533          if (!ToHandle2) {
534            auto EC = mapWindowsError(GetLastError());
535            if (EC == errc::no_such_file_or_directory)
536              break;
537            return EC;
538          }
539          BY_HANDLE_FILE_INFORMATION FI2;
540          if (!GetFileInformationByHandle(ToHandle2, &FI2))
541            return mapWindowsError(GetLastError());
542          if (FI.nFileIndexHigh != FI2.nFileIndexHigh ||
543              FI.nFileIndexLow != FI2.nFileIndexLow ||
544              FI.dwVolumeSerialNumber != FI2.dwVolumeSerialNumber)
545            break;
546          continue;
547        }
548        return EC;
549      }
550      break;
551    }
552
553    // Okay, the old destination file has probably been moved out of the way at
554    // this point, so try to rename the source file again. Still, another
555    // process might have raced with us to create and open the destination
556    // file, so we need to keep doing this until we succeed.
557  }
558
559  // The most likely root cause.
560  return errc::permission_denied;
561}
562
563static std::error_code rename_fd(int FromFD, const Twine &To) {
564  HANDLE FromHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FromFD));
565  return rename_handle(FromHandle, To);
566}
567
568std::error_code rename(const Twine &From, const Twine &To) {
569  // Convert to utf-16.
570  SmallVector<wchar_t, 128> WideFrom;
571  if (std::error_code EC = widenPath(From, WideFrom))
572    return EC;
573
574  ScopedFileHandle FromHandle;
575  // Retry this a few times to defeat badly behaved file system scanners.
576  for (unsigned Retry = 0; Retry != 200; ++Retry) {
577    if (Retry != 0)
578      ::Sleep(10);
579    FromHandle =
580        ::CreateFileW(WideFrom.begin(), GENERIC_READ | DELETE,
581                      FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
582                      NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
583    if (FromHandle)
584      break;
585
586    // We don't want to loop if the file doesn't exist.
587    auto EC = mapWindowsError(GetLastError());
588    if (EC == errc::no_such_file_or_directory)
589      return EC;
590  }
591  if (!FromHandle)
592    return mapWindowsError(GetLastError());
593
594  return rename_handle(FromHandle, To);
595}
596
597std::error_code resize_file(int FD, uint64_t Size) {
598#ifdef HAVE__CHSIZE_S
599  errno_t error = ::_chsize_s(FD, Size);
600#else
601  errno_t error = ::_chsize(FD, Size);
602#endif
603  return std::error_code(error, std::generic_category());
604}
605
606std::error_code access(const Twine &Path, AccessMode Mode) {
607  SmallVector<wchar_t, 128> PathUtf16;
608
609  if (std::error_code EC = widenPath(Path, PathUtf16))
610    return EC;
611
612  DWORD Attributes = ::GetFileAttributesW(PathUtf16.begin());
613
614  if (Attributes == INVALID_FILE_ATTRIBUTES) {
615    // See if the file didn't actually exist.
616    DWORD LastError = ::GetLastError();
617    if (LastError != ERROR_FILE_NOT_FOUND &&
618        LastError != ERROR_PATH_NOT_FOUND)
619      return mapWindowsError(LastError);
620    return errc::no_such_file_or_directory;
621  }
622
623  if (Mode == AccessMode::Write && (Attributes & FILE_ATTRIBUTE_READONLY))
624    return errc::permission_denied;
625
626  if (Mode == AccessMode::Execute && (Attributes & FILE_ATTRIBUTE_DIRECTORY))
627    return errc::permission_denied;
628
629  return std::error_code();
630}
631
632bool can_execute(const Twine &Path) {
633  return !access(Path, AccessMode::Execute) ||
634         !access(Path + ".exe", AccessMode::Execute);
635}
636
637bool equivalent(file_status A, file_status B) {
638  assert(status_known(A) && status_known(B));
639  return A.FileIndexHigh         == B.FileIndexHigh &&
640         A.FileIndexLow          == B.FileIndexLow &&
641         A.FileSizeHigh          == B.FileSizeHigh &&
642         A.FileSizeLow           == B.FileSizeLow &&
643         A.LastAccessedTimeHigh  == B.LastAccessedTimeHigh &&
644         A.LastAccessedTimeLow   == B.LastAccessedTimeLow &&
645         A.LastWriteTimeHigh     == B.LastWriteTimeHigh &&
646         A.LastWriteTimeLow      == B.LastWriteTimeLow &&
647         A.VolumeSerialNumber    == B.VolumeSerialNumber;
648}
649
650std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
651  file_status fsA, fsB;
652  if (std::error_code ec = status(A, fsA))
653    return ec;
654  if (std::error_code ec = status(B, fsB))
655    return ec;
656  result = equivalent(fsA, fsB);
657  return std::error_code();
658}
659
660static bool isReservedName(StringRef path) {
661  // This list of reserved names comes from MSDN, at:
662  // http://msdn.microsoft.com/en-us/library/aa365247%28v=vs.85%29.aspx
663  static const char *const sReservedNames[] = { "nul", "con", "prn", "aux",
664                                                "com1", "com2", "com3", "com4",
665                                                "com5", "com6", "com7", "com8",
666                                                "com9", "lpt1", "lpt2", "lpt3",
667                                                "lpt4", "lpt5", "lpt6", "lpt7",
668                                                "lpt8", "lpt9" };
669
670  // First, check to see if this is a device namespace, which always
671  // starts with \\.\, since device namespaces are not legal file paths.
672  if (path.startswith("\\\\.\\"))
673    return true;
674
675  // Then compare against the list of ancient reserved names.
676  for (size_t i = 0; i < array_lengthof(sReservedNames); ++i) {
677    if (path.equals_lower(sReservedNames[i]))
678      return true;
679  }
680
681  // The path isn't what we consider reserved.
682  return false;
683}
684
685static file_type file_type_from_attrs(DWORD Attrs) {
686  return (Attrs & FILE_ATTRIBUTE_DIRECTORY) ? file_type::directory_file
687                                            : file_type::regular_file;
688}
689
690static perms perms_from_attrs(DWORD Attrs) {
691  return (Attrs & FILE_ATTRIBUTE_READONLY) ? (all_read | all_exe) : all_all;
692}
693
694static std::error_code getStatus(HANDLE FileHandle, file_status &Result) {
695  if (FileHandle == INVALID_HANDLE_VALUE)
696    goto handle_status_error;
697
698  switch (::GetFileType(FileHandle)) {
699  default:
700    llvm_unreachable("Don't know anything about this file type");
701  case FILE_TYPE_UNKNOWN: {
702    DWORD Err = ::GetLastError();
703    if (Err != NO_ERROR)
704      return mapWindowsError(Err);
705    Result = file_status(file_type::type_unknown);
706    return std::error_code();
707  }
708  case FILE_TYPE_DISK:
709    break;
710  case FILE_TYPE_CHAR:
711    Result = file_status(file_type::character_file);
712    return std::error_code();
713  case FILE_TYPE_PIPE:
714    Result = file_status(file_type::fifo_file);
715    return std::error_code();
716  }
717
718  BY_HANDLE_FILE_INFORMATION Info;
719  if (!::GetFileInformationByHandle(FileHandle, &Info))
720    goto handle_status_error;
721
722  Result = file_status(
723      file_type_from_attrs(Info.dwFileAttributes),
724      perms_from_attrs(Info.dwFileAttributes), Info.nNumberOfLinks,
725      Info.ftLastAccessTime.dwHighDateTime, Info.ftLastAccessTime.dwLowDateTime,
726      Info.ftLastWriteTime.dwHighDateTime, Info.ftLastWriteTime.dwLowDateTime,
727      Info.dwVolumeSerialNumber, Info.nFileSizeHigh, Info.nFileSizeLow,
728      Info.nFileIndexHigh, Info.nFileIndexLow);
729  return std::error_code();
730
731handle_status_error:
732  DWORD LastError = ::GetLastError();
733  if (LastError == ERROR_FILE_NOT_FOUND ||
734      LastError == ERROR_PATH_NOT_FOUND)
735    Result = file_status(file_type::file_not_found);
736  else if (LastError == ERROR_SHARING_VIOLATION)
737    Result = file_status(file_type::type_unknown);
738  else
739    Result = file_status(file_type::status_error);
740  return mapWindowsError(LastError);
741}
742
743std::error_code status(const Twine &path, file_status &result, bool Follow) {
744  SmallString<128> path_storage;
745  SmallVector<wchar_t, 128> path_utf16;
746
747  StringRef path8 = path.toStringRef(path_storage);
748  if (isReservedName(path8)) {
749    result = file_status(file_type::character_file);
750    return std::error_code();
751  }
752
753  if (std::error_code ec = widenPath(path8, path_utf16))
754    return ec;
755
756  DWORD attr = ::GetFileAttributesW(path_utf16.begin());
757  if (attr == INVALID_FILE_ATTRIBUTES)
758    return getStatus(INVALID_HANDLE_VALUE, result);
759
760  DWORD Flags = FILE_FLAG_BACKUP_SEMANTICS;
761  // Handle reparse points.
762  if (!Follow && (attr & FILE_ATTRIBUTE_REPARSE_POINT))
763    Flags |= FILE_FLAG_OPEN_REPARSE_POINT;
764
765  ScopedFileHandle h(
766      ::CreateFileW(path_utf16.begin(), 0, // Attributes only.
767                    FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
768                    NULL, OPEN_EXISTING, Flags, 0));
769  if (!h)
770    return getStatus(INVALID_HANDLE_VALUE, result);
771
772  return getStatus(h, result);
773}
774
775std::error_code status(int FD, file_status &Result) {
776  HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
777  return getStatus(FileHandle, Result);
778}
779
780std::error_code status(file_t FileHandle, file_status &Result) {
781  return getStatus(FileHandle, Result);
782}
783
784unsigned getUmask() {
785  return 0;
786}
787
788std::error_code setPermissions(const Twine &Path, perms Permissions) {
789  SmallVector<wchar_t, 128> PathUTF16;
790  if (std::error_code EC = widenPath(Path, PathUTF16))
791    return EC;
792
793  DWORD Attributes = ::GetFileAttributesW(PathUTF16.begin());
794  if (Attributes == INVALID_FILE_ATTRIBUTES)
795    return mapWindowsError(GetLastError());
796
797  // There are many Windows file attributes that are not to do with the file
798  // permissions (e.g. FILE_ATTRIBUTE_HIDDEN). We need to be careful to preserve
799  // them.
800  if (Permissions & all_write) {
801    Attributes &= ~FILE_ATTRIBUTE_READONLY;
802    if (Attributes == 0)
803      // FILE_ATTRIBUTE_NORMAL indicates no other attributes are set.
804      Attributes |= FILE_ATTRIBUTE_NORMAL;
805  }
806  else {
807    Attributes |= FILE_ATTRIBUTE_READONLY;
808    // FILE_ATTRIBUTE_NORMAL is not compatible with any other attributes, so
809    // remove it, if it is present.
810    Attributes &= ~FILE_ATTRIBUTE_NORMAL;
811  }
812
813  if (!::SetFileAttributesW(PathUTF16.begin(), Attributes))
814    return mapWindowsError(GetLastError());
815
816  return std::error_code();
817}
818
819std::error_code setPermissions(int FD, perms Permissions) {
820  // FIXME Not implemented.
821  return std::make_error_code(std::errc::not_supported);
822}
823
824std::error_code setLastAccessAndModificationTime(int FD, TimePoint<> AccessTime,
825                                                 TimePoint<> ModificationTime) {
826  FILETIME AccessFT = toFILETIME(AccessTime);
827  FILETIME ModifyFT = toFILETIME(ModificationTime);
828  HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
829  if (!SetFileTime(FileHandle, NULL, &AccessFT, &ModifyFT))
830    return mapWindowsError(::GetLastError());
831  return std::error_code();
832}
833
834std::error_code mapped_file_region::init(sys::fs::file_t OrigFileHandle,
835                                         uint64_t Offset, mapmode Mode) {
836  this->Mode = Mode;
837  if (OrigFileHandle == INVALID_HANDLE_VALUE)
838    return make_error_code(errc::bad_file_descriptor);
839
840  DWORD flprotect;
841  switch (Mode) {
842  case readonly:  flprotect = PAGE_READONLY; break;
843  case readwrite: flprotect = PAGE_READWRITE; break;
844  case priv:      flprotect = PAGE_WRITECOPY; break;
845  }
846
847  HANDLE FileMappingHandle =
848      ::CreateFileMappingW(OrigFileHandle, 0, flprotect,
849                           Hi_32(Size),
850                           Lo_32(Size),
851                           0);
852  if (FileMappingHandle == NULL) {
853    std::error_code ec = mapWindowsError(GetLastError());
854    return ec;
855  }
856
857  DWORD dwDesiredAccess;
858  switch (Mode) {
859  case readonly:  dwDesiredAccess = FILE_MAP_READ; break;
860  case readwrite: dwDesiredAccess = FILE_MAP_WRITE; break;
861  case priv:      dwDesiredAccess = FILE_MAP_COPY; break;
862  }
863  Mapping = ::MapViewOfFile(FileMappingHandle,
864                            dwDesiredAccess,
865                            Offset >> 32,
866                            Offset & 0xffffffff,
867                            Size);
868  if (Mapping == NULL) {
869    std::error_code ec = mapWindowsError(GetLastError());
870    ::CloseHandle(FileMappingHandle);
871    return ec;
872  }
873
874  if (Size == 0) {
875    MEMORY_BASIC_INFORMATION mbi;
876    SIZE_T Result = VirtualQuery(Mapping, &mbi, sizeof(mbi));
877    if (Result == 0) {
878      std::error_code ec = mapWindowsError(GetLastError());
879      ::UnmapViewOfFile(Mapping);
880      ::CloseHandle(FileMappingHandle);
881      return ec;
882    }
883    Size = mbi.RegionSize;
884  }
885
886  // Close the file mapping handle, as it's kept alive by the file mapping. But
887  // neither the file mapping nor the file mapping handle keep the file handle
888  // alive, so we need to keep a reference to the file in case all other handles
889  // are closed and the file is deleted, which may cause invalid data to be read
890  // from the file.
891  ::CloseHandle(FileMappingHandle);
892  if (!::DuplicateHandle(::GetCurrentProcess(), OrigFileHandle,
893                         ::GetCurrentProcess(), &FileHandle, 0, 0,
894                         DUPLICATE_SAME_ACCESS)) {
895    std::error_code ec = mapWindowsError(GetLastError());
896    ::UnmapViewOfFile(Mapping);
897    return ec;
898  }
899
900  return std::error_code();
901}
902
903mapped_file_region::mapped_file_region(sys::fs::file_t fd, mapmode mode,
904                                       size_t length, uint64_t offset,
905                                       std::error_code &ec)
906    : Size(length), Mapping() {
907  ec = init(fd, offset, mode);
908  if (ec)
909    Mapping = 0;
910}
911
912static bool hasFlushBufferKernelBug() {
913  static bool Ret{GetWindowsOSVersion() < llvm::VersionTuple(10, 0, 0, 17763)};
914  return Ret;
915}
916
917static bool isEXE(StringRef Magic) {
918  static const char PEMagic[] = {'P', 'E', '\0', '\0'};
919  if (Magic.startswith(StringRef("MZ")) && Magic.size() >= 0x3c + 4) {
920    uint32_t off = read32le(Magic.data() + 0x3c);
921    // PE/COFF file, either EXE or DLL.
922    if (Magic.substr(off).startswith(StringRef(PEMagic, sizeof(PEMagic))))
923      return true;
924  }
925  return false;
926}
927
928mapped_file_region::~mapped_file_region() {
929  if (Mapping) {
930
931    bool Exe = isEXE(StringRef((char *)Mapping, Size));
932
933    ::UnmapViewOfFile(Mapping);
934
935    if (Mode == mapmode::readwrite && Exe && hasFlushBufferKernelBug()) {
936      // There is a Windows kernel bug, the exact trigger conditions of which
937      // are not well understood.  When triggered, dirty pages are not properly
938      // flushed and subsequent process's attempts to read a file can return
939      // invalid data.  Calling FlushFileBuffers on the write handle is
940      // sufficient to ensure that this bug is not triggered.
941      // The bug only occurs when writing an executable and executing it right
942      // after, under high I/O pressure.
943      ::FlushFileBuffers(FileHandle);
944    }
945
946    ::CloseHandle(FileHandle);
947  }
948}
949
950size_t mapped_file_region::size() const {
951  assert(Mapping && "Mapping failed but used anyway!");
952  return Size;
953}
954
955char *mapped_file_region::data() const {
956  assert(Mapping && "Mapping failed but used anyway!");
957  return reinterpret_cast<char*>(Mapping);
958}
959
960const char *mapped_file_region::const_data() const {
961  assert(Mapping && "Mapping failed but used anyway!");
962  return reinterpret_cast<const char*>(Mapping);
963}
964
965int mapped_file_region::alignment() {
966  SYSTEM_INFO SysInfo;
967  ::GetSystemInfo(&SysInfo);
968  return SysInfo.dwAllocationGranularity;
969}
970
971static basic_file_status status_from_find_data(WIN32_FIND_DATAW *FindData) {
972  return basic_file_status(file_type_from_attrs(FindData->dwFileAttributes),
973                           perms_from_attrs(FindData->dwFileAttributes),
974                           FindData->ftLastAccessTime.dwHighDateTime,
975                           FindData->ftLastAccessTime.dwLowDateTime,
976                           FindData->ftLastWriteTime.dwHighDateTime,
977                           FindData->ftLastWriteTime.dwLowDateTime,
978                           FindData->nFileSizeHigh, FindData->nFileSizeLow);
979}
980
981std::error_code detail::directory_iterator_construct(detail::DirIterState &IT,
982                                                     StringRef Path,
983                                                     bool FollowSymlinks) {
984  SmallVector<wchar_t, 128> PathUTF16;
985
986  if (std::error_code EC = widenPath(Path, PathUTF16))
987    return EC;
988
989  // Convert path to the format that Windows is happy with.
990  size_t PathUTF16Len = PathUTF16.size();
991  if (PathUTF16Len > 0 && !is_separator(PathUTF16[PathUTF16Len - 1]) &&
992      PathUTF16[PathUTF16Len - 1] != L':') {
993    PathUTF16.push_back(L'\\');
994    PathUTF16.push_back(L'*');
995  } else {
996    PathUTF16.push_back(L'*');
997  }
998
999  //  Get the first directory entry.
1000  WIN32_FIND_DATAW FirstFind;
1001  ScopedFindHandle FindHandle(::FindFirstFileExW(
1002      c_str(PathUTF16), FindExInfoBasic, &FirstFind, FindExSearchNameMatch,
1003      NULL, FIND_FIRST_EX_LARGE_FETCH));
1004  if (!FindHandle)
1005    return mapWindowsError(::GetLastError());
1006
1007  size_t FilenameLen = ::wcslen(FirstFind.cFileName);
1008  while ((FilenameLen == 1 && FirstFind.cFileName[0] == L'.') ||
1009         (FilenameLen == 2 && FirstFind.cFileName[0] == L'.' &&
1010                              FirstFind.cFileName[1] == L'.'))
1011    if (!::FindNextFileW(FindHandle, &FirstFind)) {
1012      DWORD LastError = ::GetLastError();
1013      // Check for end.
1014      if (LastError == ERROR_NO_MORE_FILES)
1015        return detail::directory_iterator_destruct(IT);
1016      return mapWindowsError(LastError);
1017    } else
1018      FilenameLen = ::wcslen(FirstFind.cFileName);
1019
1020  // Construct the current directory entry.
1021  SmallString<128> DirectoryEntryNameUTF8;
1022  if (std::error_code EC =
1023          UTF16ToUTF8(FirstFind.cFileName, ::wcslen(FirstFind.cFileName),
1024                      DirectoryEntryNameUTF8))
1025    return EC;
1026
1027  IT.IterationHandle = intptr_t(FindHandle.take());
1028  SmallString<128> DirectoryEntryPath(Path);
1029  path::append(DirectoryEntryPath, DirectoryEntryNameUTF8);
1030  IT.CurrentEntry =
1031      directory_entry(DirectoryEntryPath, FollowSymlinks,
1032                      file_type_from_attrs(FirstFind.dwFileAttributes),
1033                      status_from_find_data(&FirstFind));
1034
1035  return std::error_code();
1036}
1037
1038std::error_code detail::directory_iterator_destruct(detail::DirIterState &IT) {
1039  if (IT.IterationHandle != 0)
1040    // Closes the handle if it's valid.
1041    ScopedFindHandle close(HANDLE(IT.IterationHandle));
1042  IT.IterationHandle = 0;
1043  IT.CurrentEntry = directory_entry();
1044  return std::error_code();
1045}
1046
1047std::error_code detail::directory_iterator_increment(detail::DirIterState &IT) {
1048  WIN32_FIND_DATAW FindData;
1049  if (!::FindNextFileW(HANDLE(IT.IterationHandle), &FindData)) {
1050    DWORD LastError = ::GetLastError();
1051    // Check for end.
1052    if (LastError == ERROR_NO_MORE_FILES)
1053      return detail::directory_iterator_destruct(IT);
1054    return mapWindowsError(LastError);
1055  }
1056
1057  size_t FilenameLen = ::wcslen(FindData.cFileName);
1058  if ((FilenameLen == 1 && FindData.cFileName[0] == L'.') ||
1059      (FilenameLen == 2 && FindData.cFileName[0] == L'.' &&
1060                           FindData.cFileName[1] == L'.'))
1061    return directory_iterator_increment(IT);
1062
1063  SmallString<128> DirectoryEntryPathUTF8;
1064  if (std::error_code EC =
1065          UTF16ToUTF8(FindData.cFileName, ::wcslen(FindData.cFileName),
1066                      DirectoryEntryPathUTF8))
1067    return EC;
1068
1069  IT.CurrentEntry.replace_filename(
1070      Twine(DirectoryEntryPathUTF8),
1071      file_type_from_attrs(FindData.dwFileAttributes),
1072      status_from_find_data(&FindData));
1073  return std::error_code();
1074}
1075
1076ErrorOr<basic_file_status> directory_entry::status() const {
1077  return Status;
1078}
1079
1080static std::error_code nativeFileToFd(Expected<HANDLE> H, int &ResultFD,
1081                                      OpenFlags Flags) {
1082  int CrtOpenFlags = 0;
1083  if (Flags & OF_Append)
1084    CrtOpenFlags |= _O_APPEND;
1085
1086  if (Flags & OF_Text)
1087    CrtOpenFlags |= _O_TEXT;
1088
1089  ResultFD = -1;
1090  if (!H)
1091    return errorToErrorCode(H.takeError());
1092
1093  ResultFD = ::_open_osfhandle(intptr_t(*H), CrtOpenFlags);
1094  if (ResultFD == -1) {
1095    ::CloseHandle(*H);
1096    return mapWindowsError(ERROR_INVALID_HANDLE);
1097  }
1098  return std::error_code();
1099}
1100
1101static DWORD nativeDisposition(CreationDisposition Disp, OpenFlags Flags) {
1102  // This is a compatibility hack.  Really we should respect the creation
1103  // disposition, but a lot of old code relied on the implicit assumption that
1104  // OF_Append implied it would open an existing file.  Since the disposition is
1105  // now explicit and defaults to CD_CreateAlways, this assumption would cause
1106  // any usage of OF_Append to append to a new file, even if the file already
1107  // existed.  A better solution might have two new creation dispositions:
1108  // CD_AppendAlways and CD_AppendNew.  This would also address the problem of
1109  // OF_Append being used on a read-only descriptor, which doesn't make sense.
1110  if (Flags & OF_Append)
1111    return OPEN_ALWAYS;
1112
1113  switch (Disp) {
1114  case CD_CreateAlways:
1115    return CREATE_ALWAYS;
1116  case CD_CreateNew:
1117    return CREATE_NEW;
1118  case CD_OpenAlways:
1119    return OPEN_ALWAYS;
1120  case CD_OpenExisting:
1121    return OPEN_EXISTING;
1122  }
1123  llvm_unreachable("unreachable!");
1124}
1125
1126static DWORD nativeAccess(FileAccess Access, OpenFlags Flags) {
1127  DWORD Result = 0;
1128  if (Access & FA_Read)
1129    Result |= GENERIC_READ;
1130  if (Access & FA_Write)
1131    Result |= GENERIC_WRITE;
1132  if (Flags & OF_Delete)
1133    Result |= DELETE;
1134  if (Flags & OF_UpdateAtime)
1135    Result |= FILE_WRITE_ATTRIBUTES;
1136  return Result;
1137}
1138
1139static std::error_code openNativeFileInternal(const Twine &Name,
1140                                              file_t &ResultFile, DWORD Disp,
1141                                              DWORD Access, DWORD Flags,
1142                                              bool Inherit = false) {
1143  SmallVector<wchar_t, 128> PathUTF16;
1144  if (std::error_code EC = widenPath(Name, PathUTF16))
1145    return EC;
1146
1147  SECURITY_ATTRIBUTES SA;
1148  SA.nLength = sizeof(SA);
1149  SA.lpSecurityDescriptor = nullptr;
1150  SA.bInheritHandle = Inherit;
1151
1152  HANDLE H =
1153      ::CreateFileW(PathUTF16.begin(), Access,
1154                    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, &SA,
1155                    Disp, Flags, NULL);
1156  if (H == INVALID_HANDLE_VALUE) {
1157    DWORD LastError = ::GetLastError();
1158    std::error_code EC = mapWindowsError(LastError);
1159    // Provide a better error message when trying to open directories.
1160    // This only runs if we failed to open the file, so there is probably
1161    // no performances issues.
1162    if (LastError != ERROR_ACCESS_DENIED)
1163      return EC;
1164    if (is_directory(Name))
1165      return make_error_code(errc::is_a_directory);
1166    return EC;
1167  }
1168  ResultFile = H;
1169  return std::error_code();
1170}
1171
1172Expected<file_t> openNativeFile(const Twine &Name, CreationDisposition Disp,
1173                                FileAccess Access, OpenFlags Flags,
1174                                unsigned Mode) {
1175  // Verify that we don't have both "append" and "excl".
1176  assert((!(Disp == CD_CreateNew) || !(Flags & OF_Append)) &&
1177         "Cannot specify both 'CreateNew' and 'Append' file creation flags!");
1178
1179  DWORD NativeDisp = nativeDisposition(Disp, Flags);
1180  DWORD NativeAccess = nativeAccess(Access, Flags);
1181
1182  bool Inherit = false;
1183  if (Flags & OF_ChildInherit)
1184    Inherit = true;
1185
1186  file_t Result;
1187  std::error_code EC = openNativeFileInternal(
1188      Name, Result, NativeDisp, NativeAccess, FILE_ATTRIBUTE_NORMAL, Inherit);
1189  if (EC)
1190    return errorCodeToError(EC);
1191
1192  if (Flags & OF_UpdateAtime) {
1193    FILETIME FileTime;
1194    SYSTEMTIME SystemTime;
1195    GetSystemTime(&SystemTime);
1196    if (SystemTimeToFileTime(&SystemTime, &FileTime) == 0 ||
1197        SetFileTime(Result, NULL, &FileTime, NULL) == 0) {
1198      DWORD LastError = ::GetLastError();
1199      ::CloseHandle(Result);
1200      return errorCodeToError(mapWindowsError(LastError));
1201    }
1202  }
1203
1204  if (Flags & OF_Delete) {
1205    if ((EC = setDeleteDisposition(Result, true))) {
1206      ::CloseHandle(Result);
1207      return errorCodeToError(EC);
1208    }
1209  }
1210  return Result;
1211}
1212
1213std::error_code openFile(const Twine &Name, int &ResultFD,
1214                         CreationDisposition Disp, FileAccess Access,
1215                         OpenFlags Flags, unsigned int Mode) {
1216  Expected<file_t> Result = openNativeFile(Name, Disp, Access, Flags);
1217  if (!Result)
1218    return errorToErrorCode(Result.takeError());
1219
1220  return nativeFileToFd(*Result, ResultFD, Flags);
1221}
1222
1223static std::error_code directoryRealPath(const Twine &Name,
1224                                         SmallVectorImpl<char> &RealPath) {
1225  file_t File;
1226  std::error_code EC = openNativeFileInternal(
1227      Name, File, OPEN_EXISTING, GENERIC_READ, FILE_FLAG_BACKUP_SEMANTICS);
1228  if (EC)
1229    return EC;
1230
1231  EC = realPathFromHandle(File, RealPath);
1232  ::CloseHandle(File);
1233  return EC;
1234}
1235
1236std::error_code openFileForRead(const Twine &Name, int &ResultFD,
1237                                OpenFlags Flags,
1238                                SmallVectorImpl<char> *RealPath) {
1239  Expected<HANDLE> NativeFile = openNativeFileForRead(Name, Flags, RealPath);
1240  return nativeFileToFd(std::move(NativeFile), ResultFD, OF_None);
1241}
1242
1243Expected<file_t> openNativeFileForRead(const Twine &Name, OpenFlags Flags,
1244                                       SmallVectorImpl<char> *RealPath) {
1245  Expected<file_t> Result =
1246      openNativeFile(Name, CD_OpenExisting, FA_Read, Flags);
1247
1248  // Fetch the real name of the file, if the user asked
1249  if (Result && RealPath)
1250    realPathFromHandle(*Result, *RealPath);
1251
1252  return Result;
1253}
1254
1255file_t convertFDToNativeFile(int FD) {
1256  return reinterpret_cast<HANDLE>(::_get_osfhandle(FD));
1257}
1258
1259file_t getStdinHandle() { return ::GetStdHandle(STD_INPUT_HANDLE); }
1260file_t getStdoutHandle() { return ::GetStdHandle(STD_OUTPUT_HANDLE); }
1261file_t getStderrHandle() { return ::GetStdHandle(STD_ERROR_HANDLE); }
1262
1263Expected<size_t> readNativeFileImpl(file_t FileHandle,
1264                                    MutableArrayRef<char> Buf,
1265                                    OVERLAPPED *Overlap) {
1266  // ReadFile can only read 2GB at a time. The caller should check the number of
1267  // bytes and read in a loop until termination.
1268  DWORD BytesToRead =
1269      std::min(size_t(std::numeric_limits<DWORD>::max()), Buf.size());
1270  DWORD BytesRead = 0;
1271  if (::ReadFile(FileHandle, Buf.data(), BytesToRead, &BytesRead, Overlap))
1272    return BytesRead;
1273  DWORD Err = ::GetLastError();
1274  // EOF is not an error.
1275  if (Err == ERROR_BROKEN_PIPE || Err == ERROR_HANDLE_EOF)
1276    return BytesRead;
1277  return errorCodeToError(mapWindowsError(Err));
1278}
1279
1280Expected<size_t> readNativeFile(file_t FileHandle, MutableArrayRef<char> Buf) {
1281  return readNativeFileImpl(FileHandle, Buf, /*Overlap=*/nullptr);
1282}
1283
1284Expected<size_t> readNativeFileSlice(file_t FileHandle,
1285                                     MutableArrayRef<char> Buf,
1286                                     uint64_t Offset) {
1287  OVERLAPPED Overlapped = {};
1288  Overlapped.Offset = uint32_t(Offset);
1289  Overlapped.OffsetHigh = uint32_t(Offset >> 32);
1290  return readNativeFileImpl(FileHandle, Buf, &Overlapped);
1291}
1292
1293std::error_code tryLockFile(int FD, std::chrono::milliseconds Timeout) {
1294  DWORD Flags = LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY;
1295  OVERLAPPED OV = {};
1296  file_t File = convertFDToNativeFile(FD);
1297  auto Start = std::chrono::steady_clock::now();
1298  auto End = Start + Timeout;
1299  do {
1300    if (::LockFileEx(File, Flags, 0, MAXDWORD, MAXDWORD, &OV))
1301      return std::error_code();
1302    DWORD Error = ::GetLastError();
1303    if (Error == ERROR_LOCK_VIOLATION) {
1304      ::Sleep(1);
1305      continue;
1306    }
1307    return mapWindowsError(Error);
1308  } while (std::chrono::steady_clock::now() < End);
1309  return mapWindowsError(ERROR_LOCK_VIOLATION);
1310}
1311
1312std::error_code lockFile(int FD) {
1313  DWORD Flags = LOCKFILE_EXCLUSIVE_LOCK;
1314  OVERLAPPED OV = {};
1315  file_t File = convertFDToNativeFile(FD);
1316  if (::LockFileEx(File, Flags, 0, MAXDWORD, MAXDWORD, &OV))
1317    return std::error_code();
1318  DWORD Error = ::GetLastError();
1319  return mapWindowsError(Error);
1320}
1321
1322std::error_code unlockFile(int FD) {
1323  OVERLAPPED OV = {};
1324  file_t File = convertFDToNativeFile(FD);
1325  if (::UnlockFileEx(File, 0, MAXDWORD, MAXDWORD, &OV))
1326    return std::error_code();
1327  return mapWindowsError(::GetLastError());
1328}
1329
1330std::error_code closeFile(file_t &F) {
1331  file_t TmpF = F;
1332  F = kInvalidFile;
1333  if (!::CloseHandle(TmpF))
1334    return mapWindowsError(::GetLastError());
1335  return std::error_code();
1336}
1337
1338std::error_code remove_directories(const Twine &path, bool IgnoreErrors) {
1339  // Convert to utf-16.
1340  SmallVector<wchar_t, 128> Path16;
1341  std::error_code EC = widenPath(path, Path16);
1342  if (EC && !IgnoreErrors)
1343    return EC;
1344
1345  // SHFileOperation() accepts a list of paths, and so must be double null-
1346  // terminated to indicate the end of the list.  The buffer is already null
1347  // terminated, but since that null character is not considered part of the
1348  // vector's size, pushing another one will just consume that byte.  So we
1349  // need to push 2 null terminators.
1350  Path16.push_back(0);
1351  Path16.push_back(0);
1352
1353  SHFILEOPSTRUCTW shfos = {};
1354  shfos.wFunc = FO_DELETE;
1355  shfos.pFrom = Path16.data();
1356  shfos.fFlags = FOF_NO_UI;
1357
1358  int result = ::SHFileOperationW(&shfos);
1359  if (result != 0 && !IgnoreErrors)
1360    return mapWindowsError(result);
1361  return std::error_code();
1362}
1363
1364static void expandTildeExpr(SmallVectorImpl<char> &Path) {
1365  // Path does not begin with a tilde expression.
1366  if (Path.empty() || Path[0] != '~')
1367    return;
1368
1369  StringRef PathStr(Path.begin(), Path.size());
1370  PathStr = PathStr.drop_front();
1371  StringRef Expr = PathStr.take_until([](char c) { return path::is_separator(c); });
1372
1373  if (!Expr.empty()) {
1374    // This is probably a ~username/ expression.  Don't support this on Windows.
1375    return;
1376  }
1377
1378  SmallString<128> HomeDir;
1379  if (!path::home_directory(HomeDir)) {
1380    // For some reason we couldn't get the home directory.  Just exit.
1381    return;
1382  }
1383
1384  // Overwrite the first character and insert the rest.
1385  Path[0] = HomeDir[0];
1386  Path.insert(Path.begin() + 1, HomeDir.begin() + 1, HomeDir.end());
1387}
1388
1389void expand_tilde(const Twine &path, SmallVectorImpl<char> &dest) {
1390  dest.clear();
1391  if (path.isTriviallyEmpty())
1392    return;
1393
1394  path.toVector(dest);
1395  expandTildeExpr(dest);
1396
1397  return;
1398}
1399
1400std::error_code real_path(const Twine &path, SmallVectorImpl<char> &dest,
1401                          bool expand_tilde) {
1402  dest.clear();
1403  if (path.isTriviallyEmpty())
1404    return std::error_code();
1405
1406  if (expand_tilde) {
1407    SmallString<128> Storage;
1408    path.toVector(Storage);
1409    expandTildeExpr(Storage);
1410    return real_path(Storage, dest, false);
1411  }
1412
1413  if (is_directory(path))
1414    return directoryRealPath(path, dest);
1415
1416  int fd;
1417  if (std::error_code EC =
1418          llvm::sys::fs::openFileForRead(path, fd, OF_None, &dest))
1419    return EC;
1420  ::close(fd);
1421  return std::error_code();
1422}
1423
1424} // end namespace fs
1425
1426namespace path {
1427static bool getKnownFolderPath(KNOWNFOLDERID folderId,
1428                               SmallVectorImpl<char> &result) {
1429  wchar_t *path = nullptr;
1430  if (::SHGetKnownFolderPath(folderId, KF_FLAG_CREATE, nullptr, &path) != S_OK)
1431    return false;
1432
1433  bool ok = !UTF16ToUTF8(path, ::wcslen(path), result);
1434  ::CoTaskMemFree(path);
1435  return ok;
1436}
1437
1438bool home_directory(SmallVectorImpl<char> &result) {
1439  return getKnownFolderPath(FOLDERID_Profile, result);
1440}
1441
1442bool user_config_directory(SmallVectorImpl<char> &result) {
1443  // Either local or roaming appdata may be suitable in some cases, depending
1444  // on the data. Local is more conservative, Roaming may not always be correct.
1445  return getKnownFolderPath(FOLDERID_LocalAppData, result);
1446}
1447
1448bool cache_directory(SmallVectorImpl<char> &result) {
1449  return getKnownFolderPath(FOLDERID_LocalAppData, result);
1450}
1451
1452static bool getTempDirEnvVar(const wchar_t *Var, SmallVectorImpl<char> &Res) {
1453  SmallVector<wchar_t, 1024> Buf;
1454  size_t Size = 1024;
1455  do {
1456    Buf.reserve(Size);
1457    Size = GetEnvironmentVariableW(Var, Buf.data(), Buf.capacity());
1458    if (Size == 0)
1459      return false;
1460
1461    // Try again with larger buffer.
1462  } while (Size > Buf.capacity());
1463  Buf.set_size(Size);
1464
1465  return !windows::UTF16ToUTF8(Buf.data(), Size, Res);
1466}
1467
1468static bool getTempDirEnvVar(SmallVectorImpl<char> &Res) {
1469  const wchar_t *EnvironmentVariables[] = {L"TMP", L"TEMP", L"USERPROFILE"};
1470  for (auto *Env : EnvironmentVariables) {
1471    if (getTempDirEnvVar(Env, Res))
1472      return true;
1473  }
1474  return false;
1475}
1476
1477void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) {
1478  (void)ErasedOnReboot;
1479  Result.clear();
1480
1481  // Check whether the temporary directory is specified by an environment var.
1482  // This matches GetTempPath logic to some degree. GetTempPath is not used
1483  // directly as it cannot handle evn var longer than 130 chars on Windows 7
1484  // (fixed on Windows 8).
1485  if (getTempDirEnvVar(Result)) {
1486    assert(!Result.empty() && "Unexpected empty path");
1487    native(Result); // Some Unix-like shells use Unix path separator in $TMP.
1488    fs::make_absolute(Result); // Make it absolute if not already.
1489    return;
1490  }
1491
1492  // Fall back to a system default.
1493  const char *DefaultResult = "C:\\Temp";
1494  Result.append(DefaultResult, DefaultResult + strlen(DefaultResult));
1495}
1496} // end namespace path
1497
1498namespace windows {
1499std::error_code CodePageToUTF16(unsigned codepage,
1500                                llvm::StringRef original,
1501                                llvm::SmallVectorImpl<wchar_t> &utf16) {
1502  if (!original.empty()) {
1503    int len = ::MultiByteToWideChar(codepage, MB_ERR_INVALID_CHARS, original.begin(),
1504                                    original.size(), utf16.begin(), 0);
1505
1506    if (len == 0) {
1507      return mapWindowsError(::GetLastError());
1508    }
1509
1510    utf16.reserve(len + 1);
1511    utf16.set_size(len);
1512
1513    len = ::MultiByteToWideChar(codepage, MB_ERR_INVALID_CHARS, original.begin(),
1514                                original.size(), utf16.begin(), utf16.size());
1515
1516    if (len == 0) {
1517      return mapWindowsError(::GetLastError());
1518    }
1519  }
1520
1521  // Make utf16 null terminated.
1522  utf16.push_back(0);
1523  utf16.pop_back();
1524
1525  return std::error_code();
1526}
1527
1528std::error_code UTF8ToUTF16(llvm::StringRef utf8,
1529                            llvm::SmallVectorImpl<wchar_t> &utf16) {
1530  return CodePageToUTF16(CP_UTF8, utf8, utf16);
1531}
1532
1533std::error_code CurCPToUTF16(llvm::StringRef curcp,
1534                            llvm::SmallVectorImpl<wchar_t> &utf16) {
1535  return CodePageToUTF16(CP_ACP, curcp, utf16);
1536}
1537
1538static
1539std::error_code UTF16ToCodePage(unsigned codepage, const wchar_t *utf16,
1540                                size_t utf16_len,
1541                                llvm::SmallVectorImpl<char> &converted) {
1542  if (utf16_len) {
1543    // Get length.
1544    int len = ::WideCharToMultiByte(codepage, 0, utf16, utf16_len, converted.begin(),
1545                                    0, NULL, NULL);
1546
1547    if (len == 0) {
1548      return mapWindowsError(::GetLastError());
1549    }
1550
1551    converted.reserve(len);
1552    converted.set_size(len);
1553
1554    // Now do the actual conversion.
1555    len = ::WideCharToMultiByte(codepage, 0, utf16, utf16_len, converted.data(),
1556                                converted.size(), NULL, NULL);
1557
1558    if (len == 0) {
1559      return mapWindowsError(::GetLastError());
1560    }
1561  }
1562
1563  // Make the new string null terminated.
1564  converted.push_back(0);
1565  converted.pop_back();
1566
1567  return std::error_code();
1568}
1569
1570std::error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len,
1571                            llvm::SmallVectorImpl<char> &utf8) {
1572  return UTF16ToCodePage(CP_UTF8, utf16, utf16_len, utf8);
1573}
1574
1575std::error_code UTF16ToCurCP(const wchar_t *utf16, size_t utf16_len,
1576                             llvm::SmallVectorImpl<char> &curcp) {
1577  return UTF16ToCodePage(CP_ACP, utf16, utf16_len, curcp);
1578}
1579
1580} // end namespace windows
1581} // end namespace sys
1582} // end namespace llvm
1583