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1//===- llvm/Support/Windows/Path.inc - Windows Path Impl --------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the Windows specific implementation of the Path API.
11//
12//===----------------------------------------------------------------------===//
13
14//===----------------------------------------------------------------------===//
15//=== WARNING: Implementation here must contain only generic Windows code that
16//===          is guaranteed to work on *all* Windows variants.
17//===----------------------------------------------------------------------===//
18
19#include "llvm/ADT/STLExtras.h"
20#include "llvm/Support/ConvertUTF.h"
21#include "llvm/Support/WindowsError.h"
22#include <fcntl.h>
23#include <io.h>
24#include <sys/stat.h>
25#include <sys/types.h>
26
27// These two headers must be included last, and make sure shlobj is required
28// after Windows.h to make sure it picks up our definition of _WIN32_WINNT
29#include "WindowsSupport.h"
30#include <shellapi.h>
31#include <shlobj.h>
32
33#undef max
34
35// MinGW doesn't define this.
36#ifndef _ERRNO_T_DEFINED
37#define _ERRNO_T_DEFINED
38typedef int errno_t;
39#endif
40
41#ifdef _MSC_VER
42# pragma comment(lib, "advapi32.lib")  // This provides CryptAcquireContextW.
43# pragma comment(lib, "ole32.lib")     // This provides CoTaskMemFree
44#endif
45
46using namespace llvm;
47
48using llvm::sys::windows::UTF8ToUTF16;
49using llvm::sys::windows::CurCPToUTF16;
50using llvm::sys::windows::UTF16ToUTF8;
51using llvm::sys::path::widenPath;
52
53static bool is_separator(const wchar_t value) {
54  switch (value) {
55  case L'\\':
56  case L'/':
57    return true;
58  default:
59    return false;
60  }
61}
62
63namespace llvm {
64namespace sys  {
65namespace path {
66
67// Convert a UTF-8 path to UTF-16.  Also, if the absolute equivalent of the
68// path is longer than CreateDirectory can tolerate, make it absolute and
69// prefixed by '\\?\'.
70std::error_code widenPath(const Twine &Path8,
71                          SmallVectorImpl<wchar_t> &Path16) {
72  const size_t MaxDirLen = MAX_PATH - 12; // Must leave room for 8.3 filename.
73
74  // Several operations would convert Path8 to SmallString; more efficient to
75  // do it once up front.
76  SmallString<128> Path8Str;
77  Path8.toVector(Path8Str);
78
79  // If we made this path absolute, how much longer would it get?
80  size_t CurPathLen;
81  if (llvm::sys::path::is_absolute(Twine(Path8Str)))
82    CurPathLen = 0; // No contribution from current_path needed.
83  else {
84    CurPathLen = ::GetCurrentDirectoryW(0, NULL);
85    if (CurPathLen == 0)
86      return mapWindowsError(::GetLastError());
87  }
88
89  // Would the absolute path be longer than our limit?
90  if ((Path8Str.size() + CurPathLen) >= MaxDirLen &&
91      !Path8Str.startswith("\\\\?\\")) {
92    SmallString<2*MAX_PATH> FullPath("\\\\?\\");
93    if (CurPathLen) {
94      SmallString<80> CurPath;
95      if (std::error_code EC = llvm::sys::fs::current_path(CurPath))
96        return EC;
97      FullPath.append(CurPath);
98    }
99    // Traverse the requested path, canonicalizing . and .. (because the \\?\
100    // prefix is documented to treat them as real components).  Ignore
101    // separators, which can be returned from the iterator if the path has a
102    // drive name.  We don't need to call native() on the result since append()
103    // always attaches preferred_separator.
104    for (llvm::sys::path::const_iterator I = llvm::sys::path::begin(Path8Str),
105                                         E = llvm::sys::path::end(Path8Str);
106                                         I != E; ++I) {
107      if (I->size() == 1 && is_separator((*I)[0]))
108        continue;
109      if (I->size() == 1 && *I == ".")
110        continue;
111      if (I->size() == 2 && *I == "..")
112        llvm::sys::path::remove_filename(FullPath);
113      else
114        llvm::sys::path::append(FullPath, *I);
115    }
116    return UTF8ToUTF16(FullPath, Path16);
117  }
118
119  // Just use the caller's original path.
120  return UTF8ToUTF16(Path8Str, Path16);
121}
122} // end namespace path
123
124namespace fs {
125
126const file_t kInvalidFile = INVALID_HANDLE_VALUE;
127
128std::string getMainExecutable(const char *argv0, void *MainExecAddr) {
129  SmallVector<wchar_t, MAX_PATH> PathName;
130  DWORD Size = ::GetModuleFileNameW(NULL, PathName.data(), PathName.capacity());
131
132  // A zero return value indicates a failure other than insufficient space.
133  if (Size == 0)
134    return "";
135
136  // Insufficient space is determined by a return value equal to the size of
137  // the buffer passed in.
138  if (Size == PathName.capacity())
139    return "";
140
141  // On success, GetModuleFileNameW returns the number of characters written to
142  // the buffer not including the NULL terminator.
143  PathName.set_size(Size);
144
145  // Convert the result from UTF-16 to UTF-8.
146  SmallVector<char, MAX_PATH> PathNameUTF8;
147  if (UTF16ToUTF8(PathName.data(), PathName.size(), PathNameUTF8))
148    return "";
149
150  return std::string(PathNameUTF8.data());
151}
152
153UniqueID file_status::getUniqueID() const {
154  // The file is uniquely identified by the volume serial number along
155  // with the 64-bit file identifier.
156  uint64_t FileID = (static_cast<uint64_t>(FileIndexHigh) << 32ULL) |
157                    static_cast<uint64_t>(FileIndexLow);
158
159  return UniqueID(VolumeSerialNumber, FileID);
160}
161
162ErrorOr<space_info> disk_space(const Twine &Path) {
163  ULARGE_INTEGER Avail, Total, Free;
164  if (!::GetDiskFreeSpaceExA(Path.str().c_str(), &Avail, &Total, &Free))
165    return mapWindowsError(::GetLastError());
166  space_info SpaceInfo;
167  SpaceInfo.capacity =
168      (static_cast<uint64_t>(Total.HighPart) << 32) + Total.LowPart;
169  SpaceInfo.free = (static_cast<uint64_t>(Free.HighPart) << 32) + Free.LowPart;
170  SpaceInfo.available =
171      (static_cast<uint64_t>(Avail.HighPart) << 32) + Avail.LowPart;
172  return SpaceInfo;
173}
174
175TimePoint<> basic_file_status::getLastAccessedTime() const {
176  FILETIME Time;
177  Time.dwLowDateTime = LastAccessedTimeLow;
178  Time.dwHighDateTime = LastAccessedTimeHigh;
179  return toTimePoint(Time);
180}
181
182TimePoint<> basic_file_status::getLastModificationTime() const {
183  FILETIME Time;
184  Time.dwLowDateTime = LastWriteTimeLow;
185  Time.dwHighDateTime = LastWriteTimeHigh;
186  return toTimePoint(Time);
187}
188
189uint32_t file_status::getLinkCount() const {
190  return NumLinks;
191}
192
193std::error_code current_path(SmallVectorImpl<char> &result) {
194  SmallVector<wchar_t, MAX_PATH> cur_path;
195  DWORD len = MAX_PATH;
196
197  do {
198    cur_path.reserve(len);
199    len = ::GetCurrentDirectoryW(cur_path.capacity(), cur_path.data());
200
201    // A zero return value indicates a failure other than insufficient space.
202    if (len == 0)
203      return mapWindowsError(::GetLastError());
204
205    // If there's insufficient space, the len returned is larger than the len
206    // given.
207  } while (len > cur_path.capacity());
208
209  // On success, GetCurrentDirectoryW returns the number of characters not
210  // including the null-terminator.
211  cur_path.set_size(len);
212  return UTF16ToUTF8(cur_path.begin(), cur_path.size(), result);
213}
214
215std::error_code set_current_path(const Twine &path) {
216  // Convert to utf-16.
217  SmallVector<wchar_t, 128> wide_path;
218  if (std::error_code ec = widenPath(path, wide_path))
219    return ec;
220
221  if (!::SetCurrentDirectoryW(wide_path.begin()))
222    return mapWindowsError(::GetLastError());
223
224  return std::error_code();
225}
226
227std::error_code create_directory(const Twine &path, bool IgnoreExisting,
228                                 perms Perms) {
229  SmallVector<wchar_t, 128> path_utf16;
230
231  if (std::error_code ec = widenPath(path, path_utf16))
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() - 1, FILE_NAME_NORMALIZED);
355  if (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.data(), Buffer.capacity() - 1, 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  const wchar_t *Data = Buffer.data();
376  DWORD CountChars = Buffer.size();
377  if (CountChars >= 4) {
378    if (0 == ::memcmp(Data, L"\\\\?\\", 8)) {
379      CountChars -= 4;
380      Data += 4;
381    }
382  }
383
384  // Convert the result from UTF-16 to UTF-8.
385  return UTF16ToUTF8(Data, CountChars, RealPath);
386}
387
388std::error_code is_local(int FD, bool &Result) {
389  SmallVector<wchar_t, 128> FinalPath;
390  HANDLE Handle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
391
392  if (std::error_code EC = realPathFromHandle(Handle, FinalPath))
393    return EC;
394
395  return is_local_internal(FinalPath, Result);
396}
397
398static std::error_code setDeleteDisposition(HANDLE Handle, bool Delete) {
399  FILE_DISPOSITION_INFO Disposition;
400  Disposition.DeleteFile = Delete;
401  if (!SetFileInformationByHandle(Handle, FileDispositionInfo, &Disposition,
402                                  sizeof(Disposition)))
403    return mapWindowsError(::GetLastError());
404  return std::error_code();
405}
406
407static std::error_code rename_internal(HANDLE FromHandle, const Twine &To,
408                                       bool ReplaceIfExists) {
409  SmallVector<wchar_t, 0> ToWide;
410  if (auto EC = widenPath(To, ToWide))
411    return EC;
412
413  std::vector<char> RenameInfoBuf(sizeof(FILE_RENAME_INFO) - sizeof(wchar_t) +
414                                  (ToWide.size() * sizeof(wchar_t)));
415  FILE_RENAME_INFO &RenameInfo =
416      *reinterpret_cast<FILE_RENAME_INFO *>(RenameInfoBuf.data());
417  RenameInfo.ReplaceIfExists = ReplaceIfExists;
418  RenameInfo.RootDirectory = 0;
419  RenameInfo.FileNameLength = ToWide.size();
420  std::copy(ToWide.begin(), ToWide.end(), &RenameInfo.FileName[0]);
421
422  SetLastError(ERROR_SUCCESS);
423  if (!SetFileInformationByHandle(FromHandle, FileRenameInfo, &RenameInfo,
424                                  RenameInfoBuf.size())) {
425    unsigned Error = GetLastError();
426    if (Error == ERROR_SUCCESS)
427      Error = ERROR_CALL_NOT_IMPLEMENTED; // Wine doesn't always set error code.
428    return mapWindowsError(Error);
429  }
430
431  return std::error_code();
432}
433
434static std::error_code rename_handle(HANDLE FromHandle, const Twine &To) {
435  SmallVector<wchar_t, 128> WideTo;
436  if (std::error_code EC = widenPath(To, WideTo))
437    return EC;
438
439  // We normally expect this loop to succeed after a few iterations. If it
440  // requires more than 200 tries, it's more likely that the failures are due to
441  // a true error, so stop trying.
442  for (unsigned Retry = 0; Retry != 200; ++Retry) {
443    auto EC = rename_internal(FromHandle, To, true);
444
445    if (EC ==
446        std::error_code(ERROR_CALL_NOT_IMPLEMENTED, std::system_category())) {
447      // Wine doesn't support SetFileInformationByHandle in rename_internal.
448      // Fall back to MoveFileEx.
449      SmallVector<wchar_t, MAX_PATH> WideFrom;
450      if (std::error_code EC2 = realPathFromHandle(FromHandle, WideFrom))
451        return EC2;
452      if (::MoveFileExW(WideFrom.begin(), WideTo.begin(),
453                        MOVEFILE_REPLACE_EXISTING))
454        return std::error_code();
455      return mapWindowsError(GetLastError());
456    }
457
458    if (!EC || EC != errc::permission_denied)
459      return EC;
460
461    // The destination file probably exists and is currently open in another
462    // process, either because the file was opened without FILE_SHARE_DELETE or
463    // it is mapped into memory (e.g. using MemoryBuffer). Rename it in order to
464    // move it out of the way of the source file. Use FILE_FLAG_DELETE_ON_CLOSE
465    // to arrange for the destination file to be deleted when the other process
466    // closes it.
467    ScopedFileHandle ToHandle(
468        ::CreateFileW(WideTo.begin(), GENERIC_READ | DELETE,
469                      FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
470                      NULL, OPEN_EXISTING,
471                      FILE_ATTRIBUTE_NORMAL | FILE_FLAG_DELETE_ON_CLOSE, NULL));
472    if (!ToHandle) {
473      auto EC = mapWindowsError(GetLastError());
474      // Another process might have raced with us and moved the existing file
475      // out of the way before we had a chance to open it. If that happens, try
476      // to rename the source file again.
477      if (EC == errc::no_such_file_or_directory)
478        continue;
479      return EC;
480    }
481
482    BY_HANDLE_FILE_INFORMATION FI;
483    if (!GetFileInformationByHandle(ToHandle, &FI))
484      return mapWindowsError(GetLastError());
485
486    // Try to find a unique new name for the destination file.
487    for (unsigned UniqueId = 0; UniqueId != 200; ++UniqueId) {
488      std::string TmpFilename = (To + ".tmp" + utostr(UniqueId)).str();
489      if (auto EC = rename_internal(ToHandle, TmpFilename, false)) {
490        if (EC == errc::file_exists || EC == errc::permission_denied) {
491          // Again, another process might have raced with us and moved the file
492          // before we could move it. Check whether this is the case, as it
493          // might have caused the permission denied error. If that was the
494          // case, we don't need to move it ourselves.
495          ScopedFileHandle ToHandle2(::CreateFileW(
496              WideTo.begin(), 0,
497              FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
498              OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL));
499          if (!ToHandle2) {
500            auto EC = mapWindowsError(GetLastError());
501            if (EC == errc::no_such_file_or_directory)
502              break;
503            return EC;
504          }
505          BY_HANDLE_FILE_INFORMATION FI2;
506          if (!GetFileInformationByHandle(ToHandle2, &FI2))
507            return mapWindowsError(GetLastError());
508          if (FI.nFileIndexHigh != FI2.nFileIndexHigh ||
509              FI.nFileIndexLow != FI2.nFileIndexLow ||
510              FI.dwVolumeSerialNumber != FI2.dwVolumeSerialNumber)
511            break;
512          continue;
513        }
514        return EC;
515      }
516      break;
517    }
518
519    // Okay, the old destination file has probably been moved out of the way at
520    // this point, so try to rename the source file again. Still, another
521    // process might have raced with us to create and open the destination
522    // file, so we need to keep doing this until we succeed.
523  }
524
525  // The most likely root cause.
526  return errc::permission_denied;
527}
528
529static std::error_code rename_fd(int FromFD, const Twine &To) {
530  HANDLE FromHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FromFD));
531  return rename_handle(FromHandle, To);
532}
533
534std::error_code rename(const Twine &From, const Twine &To) {
535  // Convert to utf-16.
536  SmallVector<wchar_t, 128> WideFrom;
537  if (std::error_code EC = widenPath(From, WideFrom))
538    return EC;
539
540  ScopedFileHandle FromHandle;
541  // Retry this a few times to defeat badly behaved file system scanners.
542  for (unsigned Retry = 0; Retry != 200; ++Retry) {
543    if (Retry != 0)
544      ::Sleep(10);
545    FromHandle =
546        ::CreateFileW(WideFrom.begin(), GENERIC_READ | DELETE,
547                      FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
548                      NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
549    if (FromHandle)
550      break;
551  }
552  if (!FromHandle)
553    return mapWindowsError(GetLastError());
554
555  return rename_handle(FromHandle, To);
556}
557
558std::error_code resize_file(int FD, uint64_t Size) {
559#ifdef HAVE__CHSIZE_S
560  errno_t error = ::_chsize_s(FD, Size);
561#else
562  errno_t error = ::_chsize(FD, Size);
563#endif
564  return std::error_code(error, std::generic_category());
565}
566
567std::error_code access(const Twine &Path, AccessMode Mode) {
568  SmallVector<wchar_t, 128> PathUtf16;
569
570  if (std::error_code EC = widenPath(Path, PathUtf16))
571    return EC;
572
573  DWORD Attributes = ::GetFileAttributesW(PathUtf16.begin());
574
575  if (Attributes == INVALID_FILE_ATTRIBUTES) {
576    // See if the file didn't actually exist.
577    DWORD LastError = ::GetLastError();
578    if (LastError != ERROR_FILE_NOT_FOUND &&
579        LastError != ERROR_PATH_NOT_FOUND)
580      return mapWindowsError(LastError);
581    return errc::no_such_file_or_directory;
582  }
583
584  if (Mode == AccessMode::Write && (Attributes & FILE_ATTRIBUTE_READONLY))
585    return errc::permission_denied;
586
587  return std::error_code();
588}
589
590bool can_execute(const Twine &Path) {
591  return !access(Path, AccessMode::Execute) ||
592         !access(Path + ".exe", AccessMode::Execute);
593}
594
595bool equivalent(file_status A, file_status B) {
596  assert(status_known(A) && status_known(B));
597  return A.FileIndexHigh         == B.FileIndexHigh &&
598         A.FileIndexLow          == B.FileIndexLow &&
599         A.FileSizeHigh          == B.FileSizeHigh &&
600         A.FileSizeLow           == B.FileSizeLow &&
601         A.LastAccessedTimeHigh  == B.LastAccessedTimeHigh &&
602         A.LastAccessedTimeLow   == B.LastAccessedTimeLow &&
603         A.LastWriteTimeHigh     == B.LastWriteTimeHigh &&
604         A.LastWriteTimeLow      == B.LastWriteTimeLow &&
605         A.VolumeSerialNumber    == B.VolumeSerialNumber;
606}
607
608std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
609  file_status fsA, fsB;
610  if (std::error_code ec = status(A, fsA))
611    return ec;
612  if (std::error_code ec = status(B, fsB))
613    return ec;
614  result = equivalent(fsA, fsB);
615  return std::error_code();
616}
617
618static bool isReservedName(StringRef path) {
619  // This list of reserved names comes from MSDN, at:
620  // http://msdn.microsoft.com/en-us/library/aa365247%28v=vs.85%29.aspx
621  static const char *const sReservedNames[] = { "nul", "con", "prn", "aux",
622                                                "com1", "com2", "com3", "com4",
623                                                "com5", "com6", "com7", "com8",
624                                                "com9", "lpt1", "lpt2", "lpt3",
625                                                "lpt4", "lpt5", "lpt6", "lpt7",
626                                                "lpt8", "lpt9" };
627
628  // First, check to see if this is a device namespace, which always
629  // starts with \\.\, since device namespaces are not legal file paths.
630  if (path.startswith("\\\\.\\"))
631    return true;
632
633  // Then compare against the list of ancient reserved names.
634  for (size_t i = 0; i < array_lengthof(sReservedNames); ++i) {
635    if (path.equals_lower(sReservedNames[i]))
636      return true;
637  }
638
639  // The path isn't what we consider reserved.
640  return false;
641}
642
643static file_type file_type_from_attrs(DWORD Attrs) {
644  return (Attrs & FILE_ATTRIBUTE_DIRECTORY) ? file_type::directory_file
645                                            : file_type::regular_file;
646}
647
648static perms perms_from_attrs(DWORD Attrs) {
649  return (Attrs & FILE_ATTRIBUTE_READONLY) ? (all_read | all_exe) : all_all;
650}
651
652static std::error_code getStatus(HANDLE FileHandle, file_status &Result) {
653  if (FileHandle == INVALID_HANDLE_VALUE)
654    goto handle_status_error;
655
656  switch (::GetFileType(FileHandle)) {
657  default:
658    llvm_unreachable("Don't know anything about this file type");
659  case FILE_TYPE_UNKNOWN: {
660    DWORD Err = ::GetLastError();
661    if (Err != NO_ERROR)
662      return mapWindowsError(Err);
663    Result = file_status(file_type::type_unknown);
664    return std::error_code();
665  }
666  case FILE_TYPE_DISK:
667    break;
668  case FILE_TYPE_CHAR:
669    Result = file_status(file_type::character_file);
670    return std::error_code();
671  case FILE_TYPE_PIPE:
672    Result = file_status(file_type::fifo_file);
673    return std::error_code();
674  }
675
676  BY_HANDLE_FILE_INFORMATION Info;
677  if (!::GetFileInformationByHandle(FileHandle, &Info))
678    goto handle_status_error;
679
680  Result = file_status(
681      file_type_from_attrs(Info.dwFileAttributes),
682      perms_from_attrs(Info.dwFileAttributes), Info.nNumberOfLinks,
683      Info.ftLastAccessTime.dwHighDateTime, Info.ftLastAccessTime.dwLowDateTime,
684      Info.ftLastWriteTime.dwHighDateTime, Info.ftLastWriteTime.dwLowDateTime,
685      Info.dwVolumeSerialNumber, Info.nFileSizeHigh, Info.nFileSizeLow,
686      Info.nFileIndexHigh, Info.nFileIndexLow);
687  return std::error_code();
688
689handle_status_error:
690  DWORD LastError = ::GetLastError();
691  if (LastError == ERROR_FILE_NOT_FOUND ||
692      LastError == ERROR_PATH_NOT_FOUND)
693    Result = file_status(file_type::file_not_found);
694  else if (LastError == ERROR_SHARING_VIOLATION)
695    Result = file_status(file_type::type_unknown);
696  else
697    Result = file_status(file_type::status_error);
698  return mapWindowsError(LastError);
699}
700
701std::error_code status(const Twine &path, file_status &result, bool Follow) {
702  SmallString<128> path_storage;
703  SmallVector<wchar_t, 128> path_utf16;
704
705  StringRef path8 = path.toStringRef(path_storage);
706  if (isReservedName(path8)) {
707    result = file_status(file_type::character_file);
708    return std::error_code();
709  }
710
711  if (std::error_code ec = widenPath(path8, path_utf16))
712    return ec;
713
714  DWORD attr = ::GetFileAttributesW(path_utf16.begin());
715  if (attr == INVALID_FILE_ATTRIBUTES)
716    return getStatus(INVALID_HANDLE_VALUE, result);
717
718  DWORD Flags = FILE_FLAG_BACKUP_SEMANTICS;
719  // Handle reparse points.
720  if (!Follow && (attr & FILE_ATTRIBUTE_REPARSE_POINT))
721    Flags |= FILE_FLAG_OPEN_REPARSE_POINT;
722
723  ScopedFileHandle h(
724      ::CreateFileW(path_utf16.begin(), 0, // Attributes only.
725                    FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
726                    NULL, OPEN_EXISTING, Flags, 0));
727  if (!h)
728    return getStatus(INVALID_HANDLE_VALUE, result);
729
730  return getStatus(h, result);
731}
732
733std::error_code status(int FD, file_status &Result) {
734  HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
735  return getStatus(FileHandle, Result);
736}
737
738std::error_code setPermissions(const Twine &Path, perms Permissions) {
739  SmallVector<wchar_t, 128> PathUTF16;
740  if (std::error_code EC = widenPath(Path, PathUTF16))
741    return EC;
742
743  DWORD Attributes = ::GetFileAttributesW(PathUTF16.begin());
744  if (Attributes == INVALID_FILE_ATTRIBUTES)
745    return mapWindowsError(GetLastError());
746
747  // There are many Windows file attributes that are not to do with the file
748  // permissions (e.g. FILE_ATTRIBUTE_HIDDEN). We need to be careful to preserve
749  // them.
750  if (Permissions & all_write) {
751    Attributes &= ~FILE_ATTRIBUTE_READONLY;
752    if (Attributes == 0)
753      // FILE_ATTRIBUTE_NORMAL indicates no other attributes are set.
754      Attributes |= FILE_ATTRIBUTE_NORMAL;
755  }
756  else {
757    Attributes |= FILE_ATTRIBUTE_READONLY;
758    // FILE_ATTRIBUTE_NORMAL is not compatible with any other attributes, so
759    // remove it, if it is present.
760    Attributes &= ~FILE_ATTRIBUTE_NORMAL;
761  }
762
763  if (!::SetFileAttributesW(PathUTF16.begin(), Attributes))
764    return mapWindowsError(GetLastError());
765
766  return std::error_code();
767}
768
769std::error_code setLastModificationAndAccessTime(int FD, TimePoint<> Time) {
770  FILETIME FT = toFILETIME(Time);
771  HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
772  if (!SetFileTime(FileHandle, NULL, &FT, &FT))
773    return mapWindowsError(::GetLastError());
774  return std::error_code();
775}
776
777std::error_code mapped_file_region::init(int FD, uint64_t Offset,
778                                         mapmode Mode) {
779  this->Mode = Mode;
780  HANDLE OrigFileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
781  if (OrigFileHandle == INVALID_HANDLE_VALUE)
782    return make_error_code(errc::bad_file_descriptor);
783
784  DWORD flprotect;
785  switch (Mode) {
786  case readonly:  flprotect = PAGE_READONLY; break;
787  case readwrite: flprotect = PAGE_READWRITE; break;
788  case priv:      flprotect = PAGE_WRITECOPY; break;
789  }
790
791  HANDLE FileMappingHandle =
792      ::CreateFileMappingW(OrigFileHandle, 0, flprotect,
793                           Hi_32(Size),
794                           Lo_32(Size),
795                           0);
796  if (FileMappingHandle == NULL) {
797    std::error_code ec = mapWindowsError(GetLastError());
798    return ec;
799  }
800
801  DWORD dwDesiredAccess;
802  switch (Mode) {
803  case readonly:  dwDesiredAccess = FILE_MAP_READ; break;
804  case readwrite: dwDesiredAccess = FILE_MAP_WRITE; break;
805  case priv:      dwDesiredAccess = FILE_MAP_COPY; break;
806  }
807  Mapping = ::MapViewOfFile(FileMappingHandle,
808                            dwDesiredAccess,
809                            Offset >> 32,
810                            Offset & 0xffffffff,
811                            Size);
812  if (Mapping == NULL) {
813    std::error_code ec = mapWindowsError(GetLastError());
814    ::CloseHandle(FileMappingHandle);
815    return ec;
816  }
817
818  if (Size == 0) {
819    MEMORY_BASIC_INFORMATION mbi;
820    SIZE_T Result = VirtualQuery(Mapping, &mbi, sizeof(mbi));
821    if (Result == 0) {
822      std::error_code ec = mapWindowsError(GetLastError());
823      ::UnmapViewOfFile(Mapping);
824      ::CloseHandle(FileMappingHandle);
825      return ec;
826    }
827    Size = mbi.RegionSize;
828  }
829
830  // Close the file mapping handle, as it's kept alive by the file mapping. But
831  // neither the file mapping nor the file mapping handle keep the file handle
832  // alive, so we need to keep a reference to the file in case all other handles
833  // are closed and the file is deleted, which may cause invalid data to be read
834  // from the file.
835  ::CloseHandle(FileMappingHandle);
836  if (!::DuplicateHandle(::GetCurrentProcess(), OrigFileHandle,
837                         ::GetCurrentProcess(), &FileHandle, 0, 0,
838                         DUPLICATE_SAME_ACCESS)) {
839    std::error_code ec = mapWindowsError(GetLastError());
840    ::UnmapViewOfFile(Mapping);
841    return ec;
842  }
843
844  return std::error_code();
845}
846
847mapped_file_region::mapped_file_region(int fd, mapmode mode, size_t length,
848                                       uint64_t offset, std::error_code &ec)
849    : Size(length), Mapping() {
850  ec = init(fd, offset, mode);
851  if (ec)
852    Mapping = 0;
853}
854
855mapped_file_region::~mapped_file_region() {
856  if (Mapping) {
857    ::UnmapViewOfFile(Mapping);
858
859    if (Mode == mapmode::readwrite) {
860      // There is a Windows kernel bug, the exact trigger conditions of which
861      // are not well understood.  When triggered, dirty pages are not properly
862      // flushed and subsequent process's attempts to read a file can return
863      // invalid data.  Calling FlushFileBuffers on the write handle is
864      // sufficient to ensure that this bug is not triggered.
865      ::FlushFileBuffers(FileHandle);
866    }
867
868    ::CloseHandle(FileHandle);
869  }
870}
871
872size_t mapped_file_region::size() const {
873  assert(Mapping && "Mapping failed but used anyway!");
874  return Size;
875}
876
877char *mapped_file_region::data() const {
878  assert(Mapping && "Mapping failed but used anyway!");
879  return reinterpret_cast<char*>(Mapping);
880}
881
882const char *mapped_file_region::const_data() const {
883  assert(Mapping && "Mapping failed but used anyway!");
884  return reinterpret_cast<const char*>(Mapping);
885}
886
887int mapped_file_region::alignment() {
888  SYSTEM_INFO SysInfo;
889  ::GetSystemInfo(&SysInfo);
890  return SysInfo.dwAllocationGranularity;
891}
892
893static basic_file_status status_from_find_data(WIN32_FIND_DATAW *FindData) {
894  return basic_file_status(file_type_from_attrs(FindData->dwFileAttributes),
895                           perms_from_attrs(FindData->dwFileAttributes),
896                           FindData->ftLastAccessTime.dwHighDateTime,
897                           FindData->ftLastAccessTime.dwLowDateTime,
898                           FindData->ftLastWriteTime.dwHighDateTime,
899                           FindData->ftLastWriteTime.dwLowDateTime,
900                           FindData->nFileSizeHigh, FindData->nFileSizeLow);
901}
902
903std::error_code detail::directory_iterator_construct(detail::DirIterState &it,
904                                                     StringRef path,
905                                                     bool follow_symlinks) {
906  SmallVector<wchar_t, 128> path_utf16;
907
908  if (std::error_code ec = widenPath(path, path_utf16))
909    return ec;
910
911  // Convert path to the format that Windows is happy with.
912  if (path_utf16.size() > 0 &&
913      !is_separator(path_utf16[path.size() - 1]) &&
914      path_utf16[path.size() - 1] != L':') {
915    path_utf16.push_back(L'\\');
916    path_utf16.push_back(L'*');
917  } else {
918    path_utf16.push_back(L'*');
919  }
920
921  //  Get the first directory entry.
922  WIN32_FIND_DATAW FirstFind;
923  ScopedFindHandle FindHandle(::FindFirstFileExW(
924      c_str(path_utf16), FindExInfoBasic, &FirstFind, FindExSearchNameMatch,
925      NULL, FIND_FIRST_EX_LARGE_FETCH));
926  if (!FindHandle)
927    return mapWindowsError(::GetLastError());
928
929  size_t FilenameLen = ::wcslen(FirstFind.cFileName);
930  while ((FilenameLen == 1 && FirstFind.cFileName[0] == L'.') ||
931         (FilenameLen == 2 && FirstFind.cFileName[0] == L'.' &&
932                              FirstFind.cFileName[1] == L'.'))
933    if (!::FindNextFileW(FindHandle, &FirstFind)) {
934      DWORD LastError = ::GetLastError();
935      // Check for end.
936      if (LastError == ERROR_NO_MORE_FILES)
937        return detail::directory_iterator_destruct(it);
938      return mapWindowsError(LastError);
939    } else
940      FilenameLen = ::wcslen(FirstFind.cFileName);
941
942  // Construct the current directory entry.
943  SmallString<128> directory_entry_name_utf8;
944  if (std::error_code ec =
945          UTF16ToUTF8(FirstFind.cFileName, ::wcslen(FirstFind.cFileName),
946                      directory_entry_name_utf8))
947    return ec;
948
949  it.IterationHandle = intptr_t(FindHandle.take());
950  SmallString<128> directory_entry_path(path);
951  path::append(directory_entry_path, directory_entry_name_utf8);
952  it.CurrentEntry = directory_entry(directory_entry_path, follow_symlinks,
953                                    status_from_find_data(&FirstFind));
954
955  return std::error_code();
956}
957
958std::error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
959  if (it.IterationHandle != 0)
960    // Closes the handle if it's valid.
961    ScopedFindHandle close(HANDLE(it.IterationHandle));
962  it.IterationHandle = 0;
963  it.CurrentEntry = directory_entry();
964  return std::error_code();
965}
966
967std::error_code detail::directory_iterator_increment(detail::DirIterState &it) {
968  WIN32_FIND_DATAW FindData;
969  if (!::FindNextFileW(HANDLE(it.IterationHandle), &FindData)) {
970    DWORD LastError = ::GetLastError();
971    // Check for end.
972    if (LastError == ERROR_NO_MORE_FILES)
973      return detail::directory_iterator_destruct(it);
974    return mapWindowsError(LastError);
975  }
976
977  size_t FilenameLen = ::wcslen(FindData.cFileName);
978  if ((FilenameLen == 1 && FindData.cFileName[0] == L'.') ||
979      (FilenameLen == 2 && FindData.cFileName[0] == L'.' &&
980                           FindData.cFileName[1] == L'.'))
981    return directory_iterator_increment(it);
982
983  SmallString<128> directory_entry_path_utf8;
984  if (std::error_code ec =
985          UTF16ToUTF8(FindData.cFileName, ::wcslen(FindData.cFileName),
986                      directory_entry_path_utf8))
987    return ec;
988
989  it.CurrentEntry.replace_filename(Twine(directory_entry_path_utf8),
990                                   status_from_find_data(&FindData));
991  return std::error_code();
992}
993
994ErrorOr<basic_file_status> directory_entry::status() const {
995  return Status;
996}
997
998static std::error_code nativeFileToFd(Expected<HANDLE> H, int &ResultFD,
999                                      OpenFlags Flags) {
1000  int CrtOpenFlags = 0;
1001  if (Flags & OF_Append)
1002    CrtOpenFlags |= _O_APPEND;
1003
1004  if (Flags & OF_Text)
1005    CrtOpenFlags |= _O_TEXT;
1006
1007  ResultFD = -1;
1008  if (!H)
1009    return errorToErrorCode(H.takeError());
1010
1011  ResultFD = ::_open_osfhandle(intptr_t(*H), CrtOpenFlags);
1012  if (ResultFD == -1) {
1013    ::CloseHandle(*H);
1014    return mapWindowsError(ERROR_INVALID_HANDLE);
1015  }
1016  return std::error_code();
1017}
1018
1019static DWORD nativeDisposition(CreationDisposition Disp, OpenFlags Flags) {
1020  // This is a compatibility hack.  Really we should respect the creation
1021  // disposition, but a lot of old code relied on the implicit assumption that
1022  // OF_Append implied it would open an existing file.  Since the disposition is
1023  // now explicit and defaults to CD_CreateAlways, this assumption would cause
1024  // any usage of OF_Append to append to a new file, even if the file already
1025  // existed.  A better solution might have two new creation dispositions:
1026  // CD_AppendAlways and CD_AppendNew.  This would also address the problem of
1027  // OF_Append being used on a read-only descriptor, which doesn't make sense.
1028  if (Flags & OF_Append)
1029    return OPEN_ALWAYS;
1030
1031  switch (Disp) {
1032  case CD_CreateAlways:
1033    return CREATE_ALWAYS;
1034  case CD_CreateNew:
1035    return CREATE_NEW;
1036  case CD_OpenAlways:
1037    return OPEN_ALWAYS;
1038  case CD_OpenExisting:
1039    return OPEN_EXISTING;
1040  }
1041  llvm_unreachable("unreachable!");
1042}
1043
1044static DWORD nativeAccess(FileAccess Access, OpenFlags Flags) {
1045  DWORD Result = 0;
1046  if (Access & FA_Read)
1047    Result |= GENERIC_READ;
1048  if (Access & FA_Write)
1049    Result |= GENERIC_WRITE;
1050  if (Flags & OF_Delete)
1051    Result |= DELETE;
1052  if (Flags & OF_UpdateAtime)
1053    Result |= FILE_WRITE_ATTRIBUTES;
1054  return Result;
1055}
1056
1057static std::error_code openNativeFileInternal(const Twine &Name,
1058                                              file_t &ResultFile, DWORD Disp,
1059                                              DWORD Access, DWORD Flags,
1060                                              bool Inherit = false) {
1061  SmallVector<wchar_t, 128> PathUTF16;
1062  if (std::error_code EC = widenPath(Name, PathUTF16))
1063    return EC;
1064
1065  SECURITY_ATTRIBUTES SA;
1066  SA.nLength = sizeof(SA);
1067  SA.lpSecurityDescriptor = nullptr;
1068  SA.bInheritHandle = Inherit;
1069
1070  HANDLE H =
1071      ::CreateFileW(PathUTF16.begin(), Access,
1072                    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, &SA,
1073                    Disp, Flags, NULL);
1074  if (H == INVALID_HANDLE_VALUE) {
1075    DWORD LastError = ::GetLastError();
1076    std::error_code EC = mapWindowsError(LastError);
1077    // Provide a better error message when trying to open directories.
1078    // This only runs if we failed to open the file, so there is probably
1079    // no performances issues.
1080    if (LastError != ERROR_ACCESS_DENIED)
1081      return EC;
1082    if (is_directory(Name))
1083      return make_error_code(errc::is_a_directory);
1084    return EC;
1085  }
1086  ResultFile = H;
1087  return std::error_code();
1088}
1089
1090Expected<file_t> openNativeFile(const Twine &Name, CreationDisposition Disp,
1091                                FileAccess Access, OpenFlags Flags,
1092                                unsigned Mode) {
1093  // Verify that we don't have both "append" and "excl".
1094  assert((!(Disp == CD_CreateNew) || !(Flags & OF_Append)) &&
1095         "Cannot specify both 'CreateNew' and 'Append' file creation flags!");
1096
1097  DWORD NativeDisp = nativeDisposition(Disp, Flags);
1098  DWORD NativeAccess = nativeAccess(Access, Flags);
1099
1100  bool Inherit = false;
1101  if (Flags & OF_ChildInherit)
1102    Inherit = true;
1103
1104  file_t Result;
1105  std::error_code EC = openNativeFileInternal(
1106      Name, Result, NativeDisp, NativeAccess, FILE_ATTRIBUTE_NORMAL, Inherit);
1107  if (EC)
1108    return errorCodeToError(EC);
1109
1110  if (Flags & OF_UpdateAtime) {
1111    FILETIME FileTime;
1112    SYSTEMTIME SystemTime;
1113    GetSystemTime(&SystemTime);
1114    if (SystemTimeToFileTime(&SystemTime, &FileTime) == 0 ||
1115        SetFileTime(Result, NULL, &FileTime, NULL) == 0) {
1116      DWORD LastError = ::GetLastError();
1117      ::CloseHandle(Result);
1118      return errorCodeToError(mapWindowsError(LastError));
1119    }
1120  }
1121
1122  if (Flags & OF_Delete) {
1123    if ((EC = setDeleteDisposition(Result, true))) {
1124      ::CloseHandle(Result);
1125      return errorCodeToError(EC);
1126    }
1127  }
1128  return Result;
1129}
1130
1131std::error_code openFile(const Twine &Name, int &ResultFD,
1132                         CreationDisposition Disp, FileAccess Access,
1133                         OpenFlags Flags, unsigned int Mode) {
1134  Expected<file_t> Result = openNativeFile(Name, Disp, Access, Flags);
1135  if (!Result)
1136    return errorToErrorCode(Result.takeError());
1137
1138  return nativeFileToFd(*Result, ResultFD, Flags);
1139}
1140
1141static std::error_code directoryRealPath(const Twine &Name,
1142                                         SmallVectorImpl<char> &RealPath) {
1143  file_t File;
1144  std::error_code EC = openNativeFileInternal(
1145      Name, File, OPEN_EXISTING, GENERIC_READ, FILE_FLAG_BACKUP_SEMANTICS);
1146  if (EC)
1147    return EC;
1148
1149  EC = realPathFromHandle(File, RealPath);
1150  ::CloseHandle(File);
1151  return EC;
1152}
1153
1154std::error_code openFileForRead(const Twine &Name, int &ResultFD,
1155                                OpenFlags Flags,
1156                                SmallVectorImpl<char> *RealPath) {
1157  Expected<HANDLE> NativeFile = openNativeFileForRead(Name, Flags, RealPath);
1158  return nativeFileToFd(std::move(NativeFile), ResultFD, OF_None);
1159}
1160
1161Expected<file_t> openNativeFileForRead(const Twine &Name, OpenFlags Flags,
1162                                       SmallVectorImpl<char> *RealPath) {
1163  Expected<file_t> Result =
1164      openNativeFile(Name, CD_OpenExisting, FA_Read, Flags);
1165
1166  // Fetch the real name of the file, if the user asked
1167  if (Result && RealPath)
1168    realPathFromHandle(*Result, *RealPath);
1169
1170  return Result;
1171}
1172
1173void closeFile(file_t &F) {
1174  ::CloseHandle(F);
1175  F = kInvalidFile;
1176}
1177
1178std::error_code remove_directories(const Twine &path, bool IgnoreErrors) {
1179  // Convert to utf-16.
1180  SmallVector<wchar_t, 128> Path16;
1181  std::error_code EC = widenPath(path, Path16);
1182  if (EC && !IgnoreErrors)
1183    return EC;
1184
1185  // SHFileOperation() accepts a list of paths, and so must be double null-
1186  // terminated to indicate the end of the list.  The buffer is already null
1187  // terminated, but since that null character is not considered part of the
1188  // vector's size, pushing another one will just consume that byte.  So we
1189  // need to push 2 null terminators.
1190  Path16.push_back(0);
1191  Path16.push_back(0);
1192
1193  SHFILEOPSTRUCTW shfos = {};
1194  shfos.wFunc = FO_DELETE;
1195  shfos.pFrom = Path16.data();
1196  shfos.fFlags = FOF_NO_UI;
1197
1198  int result = ::SHFileOperationW(&shfos);
1199  if (result != 0 && !IgnoreErrors)
1200    return mapWindowsError(result);
1201  return std::error_code();
1202}
1203
1204static void expandTildeExpr(SmallVectorImpl<char> &Path) {
1205  // Path does not begin with a tilde expression.
1206  if (Path.empty() || Path[0] != '~')
1207    return;
1208
1209  StringRef PathStr(Path.begin(), Path.size());
1210  PathStr = PathStr.drop_front();
1211  StringRef Expr = PathStr.take_until([](char c) { return path::is_separator(c); });
1212
1213  if (!Expr.empty()) {
1214    // This is probably a ~username/ expression.  Don't support this on Windows.
1215    return;
1216  }
1217
1218  SmallString<128> HomeDir;
1219  if (!path::home_directory(HomeDir)) {
1220    // For some reason we couldn't get the home directory.  Just exit.
1221    return;
1222  }
1223
1224  // Overwrite the first character and insert the rest.
1225  Path[0] = HomeDir[0];
1226  Path.insert(Path.begin() + 1, HomeDir.begin() + 1, HomeDir.end());
1227}
1228
1229std::error_code real_path(const Twine &path, SmallVectorImpl<char> &dest,
1230                          bool expand_tilde) {
1231  dest.clear();
1232  if (path.isTriviallyEmpty())
1233    return std::error_code();
1234
1235  if (expand_tilde) {
1236    SmallString<128> Storage;
1237    path.toVector(Storage);
1238    expandTildeExpr(Storage);
1239    return real_path(Storage, dest, false);
1240  }
1241
1242  if (is_directory(path))
1243    return directoryRealPath(path, dest);
1244
1245  int fd;
1246  if (std::error_code EC =
1247          llvm::sys::fs::openFileForRead(path, fd, OF_None, &dest))
1248    return EC;
1249  ::close(fd);
1250  return std::error_code();
1251}
1252
1253} // end namespace fs
1254
1255namespace path {
1256static bool getKnownFolderPath(KNOWNFOLDERID folderId,
1257                               SmallVectorImpl<char> &result) {
1258  wchar_t *path = nullptr;
1259  if (::SHGetKnownFolderPath(folderId, KF_FLAG_CREATE, nullptr, &path) != S_OK)
1260    return false;
1261
1262  bool ok = !UTF16ToUTF8(path, ::wcslen(path), result);
1263  ::CoTaskMemFree(path);
1264  return ok;
1265}
1266
1267bool getUserCacheDir(SmallVectorImpl<char> &Result) {
1268  return getKnownFolderPath(FOLDERID_LocalAppData, Result);
1269}
1270
1271bool home_directory(SmallVectorImpl<char> &result) {
1272  return getKnownFolderPath(FOLDERID_Profile, result);
1273}
1274
1275static bool getTempDirEnvVar(const wchar_t *Var, SmallVectorImpl<char> &Res) {
1276  SmallVector<wchar_t, 1024> Buf;
1277  size_t Size = 1024;
1278  do {
1279    Buf.reserve(Size);
1280    Size = GetEnvironmentVariableW(Var, Buf.data(), Buf.capacity());
1281    if (Size == 0)
1282      return false;
1283
1284    // Try again with larger buffer.
1285  } while (Size > Buf.capacity());
1286  Buf.set_size(Size);
1287
1288  return !windows::UTF16ToUTF8(Buf.data(), Size, Res);
1289}
1290
1291static bool getTempDirEnvVar(SmallVectorImpl<char> &Res) {
1292  const wchar_t *EnvironmentVariables[] = {L"TMP", L"TEMP", L"USERPROFILE"};
1293  for (auto *Env : EnvironmentVariables) {
1294    if (getTempDirEnvVar(Env, Res))
1295      return true;
1296  }
1297  return false;
1298}
1299
1300void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) {
1301  (void)ErasedOnReboot;
1302  Result.clear();
1303
1304  // Check whether the temporary directory is specified by an environment var.
1305  // This matches GetTempPath logic to some degree. GetTempPath is not used
1306  // directly as it cannot handle evn var longer than 130 chars on Windows 7
1307  // (fixed on Windows 8).
1308  if (getTempDirEnvVar(Result)) {
1309    assert(!Result.empty() && "Unexpected empty path");
1310    native(Result); // Some Unix-like shells use Unix path separator in $TMP.
1311    fs::make_absolute(Result); // Make it absolute if not already.
1312    return;
1313  }
1314
1315  // Fall back to a system default.
1316  const char *DefaultResult = "C:\\Temp";
1317  Result.append(DefaultResult, DefaultResult + strlen(DefaultResult));
1318}
1319} // end namespace path
1320
1321namespace windows {
1322std::error_code CodePageToUTF16(unsigned codepage,
1323                                llvm::StringRef original,
1324                                llvm::SmallVectorImpl<wchar_t> &utf16) {
1325  if (!original.empty()) {
1326    int len = ::MultiByteToWideChar(codepage, MB_ERR_INVALID_CHARS, original.begin(),
1327                                    original.size(), utf16.begin(), 0);
1328
1329    if (len == 0) {
1330      return mapWindowsError(::GetLastError());
1331    }
1332
1333    utf16.reserve(len + 1);
1334    utf16.set_size(len);
1335
1336    len = ::MultiByteToWideChar(codepage, MB_ERR_INVALID_CHARS, original.begin(),
1337                                original.size(), utf16.begin(), utf16.size());
1338
1339    if (len == 0) {
1340      return mapWindowsError(::GetLastError());
1341    }
1342  }
1343
1344  // Make utf16 null terminated.
1345  utf16.push_back(0);
1346  utf16.pop_back();
1347
1348  return std::error_code();
1349}
1350
1351std::error_code UTF8ToUTF16(llvm::StringRef utf8,
1352                            llvm::SmallVectorImpl<wchar_t> &utf16) {
1353  return CodePageToUTF16(CP_UTF8, utf8, utf16);
1354}
1355
1356std::error_code CurCPToUTF16(llvm::StringRef curcp,
1357                            llvm::SmallVectorImpl<wchar_t> &utf16) {
1358  return CodePageToUTF16(CP_ACP, curcp, utf16);
1359}
1360
1361static
1362std::error_code UTF16ToCodePage(unsigned codepage, const wchar_t *utf16,
1363                                size_t utf16_len,
1364                                llvm::SmallVectorImpl<char> &converted) {
1365  if (utf16_len) {
1366    // Get length.
1367    int len = ::WideCharToMultiByte(codepage, 0, utf16, utf16_len, converted.begin(),
1368                                    0, NULL, NULL);
1369
1370    if (len == 0) {
1371      return mapWindowsError(::GetLastError());
1372    }
1373
1374    converted.reserve(len);
1375    converted.set_size(len);
1376
1377    // Now do the actual conversion.
1378    len = ::WideCharToMultiByte(codepage, 0, utf16, utf16_len, converted.data(),
1379                                converted.size(), NULL, NULL);
1380
1381    if (len == 0) {
1382      return mapWindowsError(::GetLastError());
1383    }
1384  }
1385
1386  // Make the new string null terminated.
1387  converted.push_back(0);
1388  converted.pop_back();
1389
1390  return std::error_code();
1391}
1392
1393std::error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len,
1394                            llvm::SmallVectorImpl<char> &utf8) {
1395  return UTF16ToCodePage(CP_UTF8, utf16, utf16_len, utf8);
1396}
1397
1398std::error_code UTF16ToCurCP(const wchar_t *utf16, size_t utf16_len,
1399                             llvm::SmallVectorImpl<char> &curcp) {
1400  return UTF16ToCodePage(CP_ACP, utf16, utf16_len, curcp);
1401}
1402
1403} // end namespace windows
1404} // end namespace sys
1405} // end namespace llvm
1406