Path.inc revision 2c3e0051c31c3f5b2328b447eadf1cf9c4427442 
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/WindowsError.h"
21#include <fcntl.h>
22#include <io.h>
23#include <sys/stat.h>
24#include <sys/types.h>
25
26// These two headers must be included last, and make sure shlobj is required
27// after Windows.h to make sure it picks up our definition of _WIN32_WINNT
28#include "WindowsSupport.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#endif
42
43using namespace llvm;
44
45using llvm::sys::windows::UTF8ToUTF16;
46using llvm::sys::windows::UTF16ToUTF8;
47using llvm::sys::path::widenPath;
48
49static std::error_code windows_error(DWORD E) {
50  return mapWindowsError(E);
51}
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 windows_error(::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 .. as we go (because
100    // the \\?\ prefix is documented to treat them as real components).
101    // The iterators don't report separators and append() always attaches
102    // preferred_separator so we don't need to call native() on the result.
103    for (llvm::sys::path::const_iterator I = llvm::sys::path::begin(Path8Str),
104                                         E = llvm::sys::path::end(Path8Str);
105                                         I != E; ++I) {
106      if (I->size() == 1 && *I == ".")
107        continue;
108      if (I->size() == 2 && *I == "..")
109        llvm::sys::path::remove_filename(FullPath);
110      else
111        llvm::sys::path::append(FullPath, *I);
112    }
113    return UTF8ToUTF16(FullPath, Path16);
114  }
115
116  // Just use the caller's original path.
117  return UTF8ToUTF16(Path8Str, Path16);
118}
119} // end namespace path
120
121namespace fs {
122
123std::string getMainExecutable(const char *argv0, void *MainExecAddr) {
124  SmallVector<wchar_t, MAX_PATH> PathName;
125  DWORD Size = ::GetModuleFileNameW(NULL, PathName.data(), PathName.capacity());
126
127  // A zero return value indicates a failure other than insufficient space.
128  if (Size == 0)
129    return "";
130
131  // Insufficient space is determined by a return value equal to the size of
132  // the buffer passed in.
133  if (Size == PathName.capacity())
134    return "";
135
136  // On success, GetModuleFileNameW returns the number of characters written to
137  // the buffer not including the NULL terminator.
138  PathName.set_size(Size);
139
140  // Convert the result from UTF-16 to UTF-8.
141  SmallVector<char, MAX_PATH> PathNameUTF8;
142  if (UTF16ToUTF8(PathName.data(), PathName.size(), PathNameUTF8))
143    return "";
144
145  return std::string(PathNameUTF8.data());
146}
147
148UniqueID file_status::getUniqueID() const {
149  // The file is uniquely identified by the volume serial number along
150  // with the 64-bit file identifier.
151  uint64_t FileID = (static_cast<uint64_t>(FileIndexHigh) << 32ULL) |
152                    static_cast<uint64_t>(FileIndexLow);
153
154  return UniqueID(VolumeSerialNumber, FileID);
155}
156
157TimeValue file_status::getLastModificationTime() const {
158  ULARGE_INTEGER UI;
159  UI.LowPart = LastWriteTimeLow;
160  UI.HighPart = LastWriteTimeHigh;
161
162  TimeValue Ret;
163  Ret.fromWin32Time(UI.QuadPart);
164  return Ret;
165}
166
167std::error_code current_path(SmallVectorImpl<char> &result) {
168  SmallVector<wchar_t, MAX_PATH> cur_path;
169  DWORD len = MAX_PATH;
170
171  do {
172    cur_path.reserve(len);
173    len = ::GetCurrentDirectoryW(cur_path.capacity(), cur_path.data());
174
175    // A zero return value indicates a failure other than insufficient space.
176    if (len == 0)
177      return windows_error(::GetLastError());
178
179    // If there's insufficient space, the len returned is larger than the len
180    // given.
181  } while (len > cur_path.capacity());
182
183  // On success, GetCurrentDirectoryW returns the number of characters not
184  // including the null-terminator.
185  cur_path.set_size(len);
186  return UTF16ToUTF8(cur_path.begin(), cur_path.size(), result);
187}
188
189std::error_code create_directory(const Twine &path, bool IgnoreExisting) {
190  SmallVector<wchar_t, 128> path_utf16;
191
192  if (std::error_code ec = widenPath(path, path_utf16))
193    return ec;
194
195  if (!::CreateDirectoryW(path_utf16.begin(), NULL)) {
196    DWORD LastError = ::GetLastError();
197    if (LastError != ERROR_ALREADY_EXISTS || !IgnoreExisting)
198      return windows_error(LastError);
199  }
200
201  return std::error_code();
202}
203
204// We can't use symbolic links for windows.
205std::error_code create_link(const Twine &to, const Twine &from) {
206  // Convert to utf-16.
207  SmallVector<wchar_t, 128> wide_from;
208  SmallVector<wchar_t, 128> wide_to;
209  if (std::error_code ec = widenPath(from, wide_from))
210    return ec;
211  if (std::error_code ec = widenPath(to, wide_to))
212    return ec;
213
214  if (!::CreateHardLinkW(wide_from.begin(), wide_to.begin(), NULL))
215    return windows_error(::GetLastError());
216
217  return std::error_code();
218}
219
220std::error_code remove(const Twine &path, bool IgnoreNonExisting) {
221  SmallVector<wchar_t, 128> path_utf16;
222
223  file_status ST;
224  if (std::error_code EC = status(path, ST)) {
225    if (EC != errc::no_such_file_or_directory || !IgnoreNonExisting)
226      return EC;
227    return std::error_code();
228  }
229
230  if (std::error_code ec = widenPath(path, path_utf16))
231    return ec;
232
233  if (ST.type() == file_type::directory_file) {
234    if (!::RemoveDirectoryW(c_str(path_utf16))) {
235      std::error_code EC = windows_error(::GetLastError());
236      if (EC != errc::no_such_file_or_directory || !IgnoreNonExisting)
237        return EC;
238    }
239    return std::error_code();
240  }
241  if (!::DeleteFileW(c_str(path_utf16))) {
242    std::error_code EC = windows_error(::GetLastError());
243    if (EC != errc::no_such_file_or_directory || !IgnoreNonExisting)
244      return EC;
245  }
246  return std::error_code();
247}
248
249std::error_code rename(const Twine &from, const Twine &to) {
250  // Convert to utf-16.
251  SmallVector<wchar_t, 128> wide_from;
252  SmallVector<wchar_t, 128> wide_to;
253  if (std::error_code ec = widenPath(from, wide_from))
254    return ec;
255  if (std::error_code ec = widenPath(to, wide_to))
256    return ec;
257
258  std::error_code ec = std::error_code();
259  for (int i = 0; i < 2000; i++) {
260    if (::MoveFileExW(wide_from.begin(), wide_to.begin(),
261                      MOVEFILE_COPY_ALLOWED | MOVEFILE_REPLACE_EXISTING))
262      return std::error_code();
263    DWORD LastError = ::GetLastError();
264    ec = windows_error(LastError);
265    if (LastError != ERROR_ACCESS_DENIED)
266      break;
267    // Retry MoveFile() at ACCESS_DENIED.
268    // System scanners (eg. indexer) might open the source file when
269    // It is written and closed.
270    ::Sleep(1);
271  }
272
273  return ec;
274}
275
276std::error_code resize_file(int FD, uint64_t Size) {
277#ifdef HAVE__CHSIZE_S
278  errno_t error = ::_chsize_s(FD, Size);
279#else
280  errno_t error = ::_chsize(FD, Size);
281#endif
282  return std::error_code(error, std::generic_category());
283}
284
285std::error_code access(const Twine &Path, AccessMode Mode) {
286  SmallVector<wchar_t, 128> PathUtf16;
287
288  if (std::error_code EC = widenPath(Path, PathUtf16))
289    return EC;
290
291  DWORD Attributes = ::GetFileAttributesW(PathUtf16.begin());
292
293  if (Attributes == INVALID_FILE_ATTRIBUTES) {
294    // See if the file didn't actually exist.
295    DWORD LastError = ::GetLastError();
296    if (LastError != ERROR_FILE_NOT_FOUND &&
297        LastError != ERROR_PATH_NOT_FOUND)
298      return windows_error(LastError);
299    return errc::no_such_file_or_directory;
300  }
301
302  if (Mode == AccessMode::Write && (Attributes & FILE_ATTRIBUTE_READONLY))
303    return errc::permission_denied;
304
305  return std::error_code();
306}
307
308bool equivalent(file_status A, file_status B) {
309  assert(status_known(A) && status_known(B));
310  return A.FileIndexHigh      == B.FileIndexHigh &&
311         A.FileIndexLow       == B.FileIndexLow &&
312         A.FileSizeHigh       == B.FileSizeHigh &&
313         A.FileSizeLow        == B.FileSizeLow &&
314         A.LastWriteTimeHigh  == B.LastWriteTimeHigh &&
315         A.LastWriteTimeLow   == B.LastWriteTimeLow &&
316         A.VolumeSerialNumber == B.VolumeSerialNumber;
317}
318
319std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
320  file_status fsA, fsB;
321  if (std::error_code ec = status(A, fsA))
322    return ec;
323  if (std::error_code ec = status(B, fsB))
324    return ec;
325  result = equivalent(fsA, fsB);
326  return std::error_code();
327}
328
329static bool isReservedName(StringRef path) {
330  // This list of reserved names comes from MSDN, at:
331  // http://msdn.microsoft.com/en-us/library/aa365247%28v=vs.85%29.aspx
332  static const char *sReservedNames[] = { "nul", "con", "prn", "aux",
333                              "com1", "com2", "com3", "com4", "com5", "com6",
334                              "com7", "com8", "com9", "lpt1", "lpt2", "lpt3",
335                              "lpt4", "lpt5", "lpt6", "lpt7", "lpt8", "lpt9" };
336
337  // First, check to see if this is a device namespace, which always
338  // starts with \\.\, since device namespaces are not legal file paths.
339  if (path.startswith("\\\\.\\"))
340    return true;
341
342  // Then compare against the list of ancient reserved names
343  for (size_t i = 0; i < array_lengthof(sReservedNames); ++i) {
344    if (path.equals_lower(sReservedNames[i]))
345      return true;
346  }
347
348  // The path isn't what we consider reserved.
349  return false;
350}
351
352static std::error_code getStatus(HANDLE FileHandle, file_status &Result) {
353  if (FileHandle == INVALID_HANDLE_VALUE)
354    goto handle_status_error;
355
356  switch (::GetFileType(FileHandle)) {
357  default:
358    llvm_unreachable("Don't know anything about this file type");
359  case FILE_TYPE_UNKNOWN: {
360    DWORD Err = ::GetLastError();
361    if (Err != NO_ERROR)
362      return windows_error(Err);
363    Result = file_status(file_type::type_unknown);
364    return std::error_code();
365  }
366  case FILE_TYPE_DISK:
367    break;
368  case FILE_TYPE_CHAR:
369    Result = file_status(file_type::character_file);
370    return std::error_code();
371  case FILE_TYPE_PIPE:
372    Result = file_status(file_type::fifo_file);
373    return std::error_code();
374  }
375
376  BY_HANDLE_FILE_INFORMATION Info;
377  if (!::GetFileInformationByHandle(FileHandle, &Info))
378    goto handle_status_error;
379
380  {
381    file_type Type = (Info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
382                         ? file_type::directory_file
383                         : file_type::regular_file;
384    Result =
385        file_status(Type, Info.ftLastWriteTime.dwHighDateTime,
386                    Info.ftLastWriteTime.dwLowDateTime,
387                    Info.dwVolumeSerialNumber, Info.nFileSizeHigh,
388                    Info.nFileSizeLow, Info.nFileIndexHigh, Info.nFileIndexLow);
389    return std::error_code();
390  }
391
392handle_status_error:
393  DWORD LastError = ::GetLastError();
394  if (LastError == ERROR_FILE_NOT_FOUND ||
395      LastError == ERROR_PATH_NOT_FOUND)
396    Result = file_status(file_type::file_not_found);
397  else if (LastError == ERROR_SHARING_VIOLATION)
398    Result = file_status(file_type::type_unknown);
399  else
400    Result = file_status(file_type::status_error);
401  return windows_error(LastError);
402}
403
404std::error_code status(const Twine &path, file_status &result) {
405  SmallString<128> path_storage;
406  SmallVector<wchar_t, 128> path_utf16;
407
408  StringRef path8 = path.toStringRef(path_storage);
409  if (isReservedName(path8)) {
410    result = file_status(file_type::character_file);
411    return std::error_code();
412  }
413
414  if (std::error_code ec = widenPath(path8, path_utf16))
415    return ec;
416
417  DWORD attr = ::GetFileAttributesW(path_utf16.begin());
418  if (attr == INVALID_FILE_ATTRIBUTES)
419    return getStatus(INVALID_HANDLE_VALUE, result);
420
421  // Handle reparse points.
422  if (attr & FILE_ATTRIBUTE_REPARSE_POINT) {
423    ScopedFileHandle h(
424      ::CreateFileW(path_utf16.begin(),
425                    0, // Attributes only.
426                    FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
427                    NULL,
428                    OPEN_EXISTING,
429                    FILE_FLAG_BACKUP_SEMANTICS,
430                    0));
431    if (!h)
432      return getStatus(INVALID_HANDLE_VALUE, result);
433  }
434
435  ScopedFileHandle h(
436      ::CreateFileW(path_utf16.begin(), 0, // Attributes only.
437                    FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
438                    NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0));
439    if (!h)
440      return getStatus(INVALID_HANDLE_VALUE, result);
441
442    return getStatus(h, result);
443}
444
445std::error_code status(int FD, file_status &Result) {
446  HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
447  return getStatus(FileHandle, Result);
448}
449
450std::error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
451  ULARGE_INTEGER UI;
452  UI.QuadPart = Time.toWin32Time();
453  FILETIME FT;
454  FT.dwLowDateTime = UI.LowPart;
455  FT.dwHighDateTime = UI.HighPart;
456  HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
457  if (!SetFileTime(FileHandle, NULL, &FT, &FT))
458    return windows_error(::GetLastError());
459  return std::error_code();
460}
461
462std::error_code mapped_file_region::init(int FD, uint64_t Offset,
463                                         mapmode Mode) {
464  // Make sure that the requested size fits within SIZE_T.
465  if (Size > std::numeric_limits<SIZE_T>::max())
466    return make_error_code(errc::invalid_argument);
467
468  HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
469  if (FileHandle == INVALID_HANDLE_VALUE)
470    return make_error_code(errc::bad_file_descriptor);
471
472  DWORD flprotect;
473  switch (Mode) {
474  case readonly:  flprotect = PAGE_READONLY; break;
475  case readwrite: flprotect = PAGE_READWRITE; break;
476  case priv:      flprotect = PAGE_WRITECOPY; break;
477  }
478
479  HANDLE FileMappingHandle =
480      ::CreateFileMappingW(FileHandle, 0, flprotect,
481                           (Offset + Size) >> 32,
482                           (Offset + Size) & 0xffffffff,
483                           0);
484  if (FileMappingHandle == NULL) {
485    std::error_code ec = windows_error(GetLastError());
486    return ec;
487  }
488
489  DWORD dwDesiredAccess;
490  switch (Mode) {
491  case readonly:  dwDesiredAccess = FILE_MAP_READ; break;
492  case readwrite: dwDesiredAccess = FILE_MAP_WRITE; break;
493  case priv:      dwDesiredAccess = FILE_MAP_COPY; break;
494  }
495  Mapping = ::MapViewOfFile(FileMappingHandle,
496                            dwDesiredAccess,
497                            Offset >> 32,
498                            Offset & 0xffffffff,
499                            Size);
500  if (Mapping == NULL) {
501    std::error_code ec = windows_error(GetLastError());
502    ::CloseHandle(FileMappingHandle);
503    return ec;
504  }
505
506  if (Size == 0) {
507    MEMORY_BASIC_INFORMATION mbi;
508    SIZE_T Result = VirtualQuery(Mapping, &mbi, sizeof(mbi));
509    if (Result == 0) {
510      std::error_code ec = windows_error(GetLastError());
511      ::UnmapViewOfFile(Mapping);
512      ::CloseHandle(FileMappingHandle);
513      return ec;
514    }
515    Size = mbi.RegionSize;
516  }
517
518  // Close all the handles except for the view. It will keep the other handles
519  // alive.
520  ::CloseHandle(FileMappingHandle);
521  return std::error_code();
522}
523
524mapped_file_region::mapped_file_region(int fd, mapmode mode, uint64_t length,
525                                       uint64_t offset, std::error_code &ec)
526    : Size(length), Mapping() {
527  ec = init(fd, offset, mode);
528  if (ec)
529    Mapping = 0;
530}
531
532mapped_file_region::~mapped_file_region() {
533  if (Mapping)
534    ::UnmapViewOfFile(Mapping);
535}
536
537uint64_t mapped_file_region::size() const {
538  assert(Mapping && "Mapping failed but used anyway!");
539  return Size;
540}
541
542char *mapped_file_region::data() const {
543  assert(Mapping && "Mapping failed but used anyway!");
544  return reinterpret_cast<char*>(Mapping);
545}
546
547const char *mapped_file_region::const_data() const {
548  assert(Mapping && "Mapping failed but used anyway!");
549  return reinterpret_cast<const char*>(Mapping);
550}
551
552int mapped_file_region::alignment() {
553  SYSTEM_INFO SysInfo;
554  ::GetSystemInfo(&SysInfo);
555  return SysInfo.dwAllocationGranularity;
556}
557
558std::error_code detail::directory_iterator_construct(detail::DirIterState &it,
559                                                StringRef path){
560  SmallVector<wchar_t, 128> path_utf16;
561
562  if (std::error_code ec = widenPath(path, path_utf16))
563    return ec;
564
565  // Convert path to the format that Windows is happy with.
566  if (path_utf16.size() > 0 &&
567      !is_separator(path_utf16[path.size() - 1]) &&
568      path_utf16[path.size() - 1] != L':') {
569    path_utf16.push_back(L'\\');
570    path_utf16.push_back(L'*');
571  } else {
572    path_utf16.push_back(L'*');
573  }
574
575  //  Get the first directory entry.
576  WIN32_FIND_DATAW FirstFind;
577  ScopedFindHandle FindHandle(::FindFirstFileW(c_str(path_utf16), &FirstFind));
578  if (!FindHandle)
579    return windows_error(::GetLastError());
580
581  size_t FilenameLen = ::wcslen(FirstFind.cFileName);
582  while ((FilenameLen == 1 && FirstFind.cFileName[0] == L'.') ||
583         (FilenameLen == 2 && FirstFind.cFileName[0] == L'.' &&
584                              FirstFind.cFileName[1] == L'.'))
585    if (!::FindNextFileW(FindHandle, &FirstFind)) {
586      DWORD LastError = ::GetLastError();
587      // Check for end.
588      if (LastError == ERROR_NO_MORE_FILES)
589        return detail::directory_iterator_destruct(it);
590      return windows_error(LastError);
591    } else
592      FilenameLen = ::wcslen(FirstFind.cFileName);
593
594  // Construct the current directory entry.
595  SmallString<128> directory_entry_name_utf8;
596  if (std::error_code ec =
597          UTF16ToUTF8(FirstFind.cFileName, ::wcslen(FirstFind.cFileName),
598                      directory_entry_name_utf8))
599    return ec;
600
601  it.IterationHandle = intptr_t(FindHandle.take());
602  SmallString<128> directory_entry_path(path);
603  path::append(directory_entry_path, directory_entry_name_utf8);
604  it.CurrentEntry = directory_entry(directory_entry_path);
605
606  return std::error_code();
607}
608
609std::error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
610  if (it.IterationHandle != 0)
611    // Closes the handle if it's valid.
612    ScopedFindHandle close(HANDLE(it.IterationHandle));
613  it.IterationHandle = 0;
614  it.CurrentEntry = directory_entry();
615  return std::error_code();
616}
617
618std::error_code detail::directory_iterator_increment(detail::DirIterState &it) {
619  WIN32_FIND_DATAW FindData;
620  if (!::FindNextFileW(HANDLE(it.IterationHandle), &FindData)) {
621    DWORD LastError = ::GetLastError();
622    // Check for end.
623    if (LastError == ERROR_NO_MORE_FILES)
624      return detail::directory_iterator_destruct(it);
625    return windows_error(LastError);
626  }
627
628  size_t FilenameLen = ::wcslen(FindData.cFileName);
629  if ((FilenameLen == 1 && FindData.cFileName[0] == L'.') ||
630      (FilenameLen == 2 && FindData.cFileName[0] == L'.' &&
631                           FindData.cFileName[1] == L'.'))
632    return directory_iterator_increment(it);
633
634  SmallString<128> directory_entry_path_utf8;
635  if (std::error_code ec =
636          UTF16ToUTF8(FindData.cFileName, ::wcslen(FindData.cFileName),
637                      directory_entry_path_utf8))
638    return ec;
639
640  it.CurrentEntry.replace_filename(Twine(directory_entry_path_utf8));
641  return std::error_code();
642}
643
644std::error_code openFileForRead(const Twine &Name, int &ResultFD) {
645  SmallVector<wchar_t, 128> PathUTF16;
646
647  if (std::error_code EC = widenPath(Name, PathUTF16))
648    return EC;
649
650  HANDLE H = ::CreateFileW(PathUTF16.begin(), GENERIC_READ,
651                           FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
652                           OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
653  if (H == INVALID_HANDLE_VALUE) {
654    DWORD LastError = ::GetLastError();
655    std::error_code EC = windows_error(LastError);
656    // Provide a better error message when trying to open directories.
657    // This only runs if we failed to open the file, so there is probably
658    // no performances issues.
659    if (LastError != ERROR_ACCESS_DENIED)
660      return EC;
661    if (is_directory(Name))
662      return make_error_code(errc::is_a_directory);
663    return EC;
664  }
665
666  int FD = ::_open_osfhandle(intptr_t(H), 0);
667  if (FD == -1) {
668    ::CloseHandle(H);
669    return windows_error(ERROR_INVALID_HANDLE);
670  }
671
672  ResultFD = FD;
673  return std::error_code();
674}
675
676std::error_code openFileForWrite(const Twine &Name, int &ResultFD,
677                            sys::fs::OpenFlags Flags, unsigned Mode) {
678  // Verify that we don't have both "append" and "excl".
679  assert((!(Flags & sys::fs::F_Excl) || !(Flags & sys::fs::F_Append)) &&
680         "Cannot specify both 'excl' and 'append' file creation flags!");
681
682  SmallVector<wchar_t, 128> PathUTF16;
683
684  if (std::error_code EC = widenPath(Name, PathUTF16))
685    return EC;
686
687  DWORD CreationDisposition;
688  if (Flags & F_Excl)
689    CreationDisposition = CREATE_NEW;
690  else if (Flags & F_Append)
691    CreationDisposition = OPEN_ALWAYS;
692  else
693    CreationDisposition = CREATE_ALWAYS;
694
695  DWORD Access = GENERIC_WRITE;
696  if (Flags & F_RW)
697    Access |= GENERIC_READ;
698
699  HANDLE H = ::CreateFileW(PathUTF16.begin(), Access,
700                           FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
701                           CreationDisposition, FILE_ATTRIBUTE_NORMAL, NULL);
702
703  if (H == INVALID_HANDLE_VALUE) {
704    DWORD LastError = ::GetLastError();
705    std::error_code EC = windows_error(LastError);
706    // Provide a better error message when trying to open directories.
707    // This only runs if we failed to open the file, so there is probably
708    // no performances issues.
709    if (LastError != ERROR_ACCESS_DENIED)
710      return EC;
711    if (is_directory(Name))
712      return make_error_code(errc::is_a_directory);
713    return EC;
714  }
715
716  int OpenFlags = 0;
717  if (Flags & F_Append)
718    OpenFlags |= _O_APPEND;
719
720  if (Flags & F_Text)
721    OpenFlags |= _O_TEXT;
722
723  int FD = ::_open_osfhandle(intptr_t(H), OpenFlags);
724  if (FD == -1) {
725    ::CloseHandle(H);
726    return windows_error(ERROR_INVALID_HANDLE);
727  }
728
729  ResultFD = FD;
730  return std::error_code();
731}
732} // end namespace fs
733
734namespace path {
735
736bool home_directory(SmallVectorImpl<char> &result) {
737  wchar_t Path[MAX_PATH];
738  if (::SHGetFolderPathW(0, CSIDL_APPDATA | CSIDL_FLAG_CREATE, 0,
739                         /*SHGFP_TYPE_CURRENT*/0, Path) != S_OK)
740    return false;
741
742  if (UTF16ToUTF8(Path, ::wcslen(Path), result))
743    return false;
744
745  return true;
746}
747
748static bool getTempDirEnvVar(const char *Var, SmallVectorImpl<char> &Res) {
749  SmallVector<wchar_t, 128> NameUTF16;
750  if (windows::UTF8ToUTF16(Var, NameUTF16))
751    return false;
752
753  SmallVector<wchar_t, 1024> Buf;
754  size_t Size = 1024;
755  do {
756    Buf.reserve(Size);
757    Size =
758        GetEnvironmentVariableW(NameUTF16.data(), Buf.data(), Buf.capacity());
759    if (Size == 0)
760      return false;
761
762    // Try again with larger buffer.
763  } while (Size > Buf.capacity());
764  Buf.set_size(Size);
765
766  if (windows::UTF16ToUTF8(Buf.data(), Size, Res))
767    return false;
768  return true;
769}
770
771static bool getTempDirEnvVar(SmallVectorImpl<char> &Res) {
772  const char *EnvironmentVariables[] = {"TMP", "TEMP", "USERPROFILE"};
773  for (const char *Env : EnvironmentVariables) {
774    if (getTempDirEnvVar(Env, Res))
775      return true;
776  }
777  return false;
778}
779
780void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) {
781  (void)ErasedOnReboot;
782  Result.clear();
783
784  // Check whether the temporary directory is specified by an environment
785  // variable.
786  if (getTempDirEnvVar(Result))
787    return;
788
789  // Fall back to a system default.
790  const char *DefaultResult = "C:\\TEMP";
791  Result.append(DefaultResult, DefaultResult + strlen(DefaultResult));
792}
793} // end namespace path
794
795namespace windows {
796std::error_code UTF8ToUTF16(llvm::StringRef utf8,
797                            llvm::SmallVectorImpl<wchar_t> &utf16) {
798  if (!utf8.empty()) {
799    int len = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, utf8.begin(),
800                                    utf8.size(), utf16.begin(), 0);
801
802    if (len == 0)
803      return windows_error(::GetLastError());
804
805    utf16.reserve(len + 1);
806    utf16.set_size(len);
807
808    len = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, utf8.begin(),
809                                utf8.size(), utf16.begin(), utf16.size());
810
811    if (len == 0)
812      return windows_error(::GetLastError());
813  }
814
815  // Make utf16 null terminated.
816  utf16.push_back(0);
817  utf16.pop_back();
818
819  return std::error_code();
820}
821
822static
823std::error_code UTF16ToCodePage(unsigned codepage, const wchar_t *utf16,
824                                size_t utf16_len,
825                                llvm::SmallVectorImpl<char> &utf8) {
826  if (utf16_len) {
827    // Get length.
828    int len = ::WideCharToMultiByte(codepage, 0, utf16, utf16_len, utf8.begin(),
829                                    0, NULL, NULL);
830
831    if (len == 0)
832      return windows_error(::GetLastError());
833
834    utf8.reserve(len);
835    utf8.set_size(len);
836
837    // Now do the actual conversion.
838    len = ::WideCharToMultiByte(codepage, 0, utf16, utf16_len, utf8.data(),
839                                utf8.size(), NULL, NULL);
840
841    if (len == 0)
842      return windows_error(::GetLastError());
843  }
844
845  // Make utf8 null terminated.
846  utf8.push_back(0);
847  utf8.pop_back();
848
849  return std::error_code();
850}
851
852std::error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len,
853                            llvm::SmallVectorImpl<char> &utf8) {
854  return UTF16ToCodePage(CP_UTF8, utf16, utf16_len, utf8);
855}
856
857std::error_code UTF16ToCurCP(const wchar_t *utf16, size_t utf16_len,
858                             llvm::SmallVectorImpl<char> &utf8) {
859  return UTF16ToCodePage(CP_ACP, utf16, utf16_len, utf8);
860}
861} // end namespace windows
862} // end namespace sys
863} // end namespace llvm
864