1//===- llvm/Support/Unix/Path.inc - Unix Path Implementation ----*- 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 Unix specific implementation of the Path API.
11//
12//===----------------------------------------------------------------------===//
13
14//===----------------------------------------------------------------------===//
15//=== WARNING: Implementation here must contain only generic UNIX code that
16//===          is guaranteed to work on *all* UNIX variants.
17//===----------------------------------------------------------------------===//
18
19#include "Unix.h"
20#include "llvm/Support/Process.h"
21#include <limits.h>
22#include <stdio.h>
23#if HAVE_SYS_STAT_H
24#include <sys/stat.h>
25#endif
26#if HAVE_FCNTL_H
27#include <fcntl.h>
28#endif
29#ifdef HAVE_SYS_MMAN_H
30#include <sys/mman.h>
31#endif
32#if HAVE_DIRENT_H
33# include <dirent.h>
34# define NAMLEN(dirent) strlen((dirent)->d_name)
35#else
36# define dirent direct
37# define NAMLEN(dirent) (dirent)->d_namlen
38# if HAVE_SYS_NDIR_H
39#  include <sys/ndir.h>
40# endif
41# if HAVE_SYS_DIR_H
42#  include <sys/dir.h>
43# endif
44# if HAVE_NDIR_H
45#  include <ndir.h>
46# endif
47#endif
48
49#ifdef __APPLE__
50#include <mach-o/dyld.h>
51#endif
52
53// Both stdio.h and cstdio are included via different pathes and
54// stdcxx's cstdio doesn't include stdio.h, so it doesn't #undef the macros
55// either.
56#undef ferror
57#undef feof
58
59// For GNU Hurd
60#if defined(__GNU__) && !defined(PATH_MAX)
61# define PATH_MAX 4096
62#endif
63
64using namespace llvm;
65
66namespace {
67  /// This class automatically closes the given file descriptor when it goes out
68  /// of scope. You can take back explicit ownership of the file descriptor by
69  /// calling take(). The destructor does not verify that close was successful.
70  /// Therefore, never allow this class to call close on a file descriptor that
71  /// has been read from or written to.
72  struct AutoFD {
73    int FileDescriptor;
74
75    AutoFD(int fd) : FileDescriptor(fd) {}
76    ~AutoFD() {
77      if (FileDescriptor >= 0)
78        ::close(FileDescriptor);
79    }
80
81    int take() {
82      int ret = FileDescriptor;
83      FileDescriptor = -1;
84      return ret;
85    }
86
87    operator int() const {return FileDescriptor;}
88  };
89
90  error_code TempDir(SmallVectorImpl<char> &result) {
91    // FIXME: Don't use TMPDIR if program is SUID or SGID enabled.
92    const char *dir = 0;
93    (dir = std::getenv("TMPDIR" )) ||
94    (dir = std::getenv("TMP"    )) ||
95    (dir = std::getenv("TEMP"   )) ||
96    (dir = std::getenv("TEMPDIR")) ||
97#ifdef P_tmpdir
98    (dir = P_tmpdir) ||
99#endif
100    (dir = "/tmp");
101
102    result.clear();
103    StringRef d(dir);
104    result.append(d.begin(), d.end());
105    return error_code::success();
106  }
107}
108
109static error_code createUniqueEntity(const Twine &Model, int &ResultFD,
110                                     SmallVectorImpl<char> &ResultPath,
111                                     bool MakeAbsolute, unsigned Mode,
112                                     FSEntity Type) {
113  SmallString<128> ModelStorage;
114  Model.toVector(ModelStorage);
115
116  if (MakeAbsolute) {
117    // Make model absolute by prepending a temp directory if it's not already.
118    bool absolute = sys::path::is_absolute(Twine(ModelStorage));
119    if (!absolute) {
120      SmallString<128> TDir;
121      if (error_code ec = TempDir(TDir)) return ec;
122      sys::path::append(TDir, Twine(ModelStorage));
123      ModelStorage.swap(TDir);
124    }
125  }
126
127  // From here on, DO NOT modify model. It may be needed if the randomly chosen
128  // path already exists.
129  ResultPath = ModelStorage;
130  // Null terminate.
131  ResultPath.push_back(0);
132  ResultPath.pop_back();
133
134retry_random_path:
135  // Replace '%' with random chars.
136  for (unsigned i = 0, e = ModelStorage.size(); i != e; ++i) {
137    if (ModelStorage[i] == '%')
138      ResultPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];
139  }
140
141  // Try to open + create the file.
142  switch (Type) {
143  case FS_File: {
144    int RandomFD = ::open(ResultPath.begin(), O_RDWR | O_CREAT | O_EXCL, Mode);
145    if (RandomFD == -1) {
146      int SavedErrno = errno;
147      // If the file existed, try again, otherwise, error.
148      if (SavedErrno == errc::file_exists)
149        goto retry_random_path;
150      return error_code(SavedErrno, system_category());
151    }
152
153    ResultFD = RandomFD;
154    return error_code::success();
155  }
156
157  case FS_Name: {
158    bool Exists;
159    error_code EC = sys::fs::exists(ResultPath.begin(), Exists);
160    if (EC)
161      return EC;
162    if (Exists)
163      goto retry_random_path;
164    return error_code::success();
165  }
166
167  case FS_Dir: {
168    bool Existed;
169    error_code EC = sys::fs::create_directory(ResultPath.begin(), Existed);
170    if (EC)
171      return EC;
172    if (Existed)
173      goto retry_random_path;
174    return error_code::success();
175  }
176  }
177  llvm_unreachable("Invalid Type");
178}
179
180namespace llvm {
181namespace sys  {
182namespace fs {
183#if defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
184    defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__) || \
185    defined(__linux__) || defined(__CYGWIN__)
186static int
187test_dir(char buf[PATH_MAX], char ret[PATH_MAX],
188    const char *dir, const char *bin)
189{
190  struct stat sb;
191
192  snprintf(buf, PATH_MAX, "%s/%s", dir, bin);
193  if (realpath(buf, ret) == NULL)
194    return (1);
195  if (stat(buf, &sb) != 0)
196    return (1);
197
198  return (0);
199}
200
201static char *
202getprogpath(char ret[PATH_MAX], const char *bin)
203{
204  char *pv, *s, *t, buf[PATH_MAX];
205
206  /* First approach: absolute path. */
207  if (bin[0] == '/') {
208    if (test_dir(buf, ret, "/", bin) == 0)
209      return (ret);
210    return (NULL);
211  }
212
213  /* Second approach: relative path. */
214  if (strchr(bin, '/') != NULL) {
215    if (getcwd(buf, PATH_MAX) == NULL)
216      return (NULL);
217    if (test_dir(buf, ret, buf, bin) == 0)
218      return (ret);
219    return (NULL);
220  }
221
222  /* Third approach: $PATH */
223  if ((pv = getenv("PATH")) == NULL)
224    return (NULL);
225  s = pv = strdup(pv);
226  if (pv == NULL)
227    return (NULL);
228  while ((t = strsep(&s, ":")) != NULL) {
229    if (test_dir(buf, ret, t, bin) == 0) {
230      free(pv);
231      return (ret);
232    }
233  }
234  free(pv);
235  return (NULL);
236}
237#endif // __FreeBSD__ || __NetBSD__ || __FreeBSD_kernel__
238
239/// GetMainExecutable - Return the path to the main executable, given the
240/// value of argv[0] from program startup.
241std::string getMainExecutable(const char *argv0, void *MainAddr) {
242#if defined(__APPLE__)
243  // On OS X the executable path is saved to the stack by dyld. Reading it
244  // from there is much faster than calling dladdr, especially for large
245  // binaries with symbols.
246  char exe_path[MAXPATHLEN];
247  uint32_t size = sizeof(exe_path);
248  if (_NSGetExecutablePath(exe_path, &size) == 0) {
249    char link_path[MAXPATHLEN];
250    if (realpath(exe_path, link_path))
251      return link_path;
252  }
253#elif defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
254      defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__)
255  char exe_path[PATH_MAX];
256
257  if (getprogpath(exe_path, argv0) != NULL)
258    return exe_path;
259#elif defined(__linux__) || defined(__CYGWIN__)
260  char exe_path[MAXPATHLEN];
261  StringRef aPath("/proc/self/exe");
262  if (sys::fs::exists(aPath)) {
263      // /proc is not always mounted under Linux (chroot for example).
264      ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path));
265      if (len >= 0)
266          return StringRef(exe_path, len);
267  } else {
268      // Fall back to the classical detection.
269      if (getprogpath(exe_path, argv0) != NULL)
270          return exe_path;
271  }
272#elif defined(HAVE_DLFCN_H)
273  // Use dladdr to get executable path if available.
274  Dl_info DLInfo;
275  int err = dladdr(MainAddr, &DLInfo);
276  if (err == 0)
277    return "";
278
279  // If the filename is a symlink, we need to resolve and return the location of
280  // the actual executable.
281  char link_path[MAXPATHLEN];
282  if (realpath(DLInfo.dli_fname, link_path))
283    return link_path;
284#else
285#error GetMainExecutable is not implemented on this host yet.
286#endif
287  return "";
288}
289
290TimeValue file_status::getLastModificationTime() const {
291  TimeValue Ret;
292  Ret.fromEpochTime(fs_st_mtime);
293  return Ret;
294}
295
296UniqueID file_status::getUniqueID() const {
297  return UniqueID(fs_st_dev, fs_st_ino);
298}
299
300error_code current_path(SmallVectorImpl<char> &result) {
301  result.clear();
302
303  const char *pwd = ::getenv("PWD");
304  llvm::sys::fs::file_status PWDStatus, DotStatus;
305  if (pwd && llvm::sys::path::is_absolute(pwd) &&
306      !llvm::sys::fs::status(pwd, PWDStatus) &&
307      !llvm::sys::fs::status(".", DotStatus) &&
308      PWDStatus.getUniqueID() == DotStatus.getUniqueID()) {
309    result.append(pwd, pwd + strlen(pwd));
310    return error_code::success();
311  }
312
313#ifdef MAXPATHLEN
314  result.reserve(MAXPATHLEN);
315#else
316// For GNU Hurd
317  result.reserve(1024);
318#endif
319
320  while (true) {
321    if (::getcwd(result.data(), result.capacity()) == 0) {
322      // See if there was a real error.
323      if (errno != errc::not_enough_memory)
324        return error_code(errno, system_category());
325      // Otherwise there just wasn't enough space.
326      result.reserve(result.capacity() * 2);
327    } else
328      break;
329  }
330
331  result.set_size(strlen(result.data()));
332  return error_code::success();
333}
334
335error_code create_directory(const Twine &path, bool &existed) {
336  SmallString<128> path_storage;
337  StringRef p = path.toNullTerminatedStringRef(path_storage);
338
339  if (::mkdir(p.begin(), S_IRWXU | S_IRWXG) == -1) {
340    if (errno != errc::file_exists)
341      return error_code(errno, system_category());
342    existed = true;
343  } else
344    existed = false;
345
346  return error_code::success();
347}
348
349error_code create_hard_link(const Twine &to, const Twine &from) {
350  // Get arguments.
351  SmallString<128> from_storage;
352  SmallString<128> to_storage;
353  StringRef f = from.toNullTerminatedStringRef(from_storage);
354  StringRef t = to.toNullTerminatedStringRef(to_storage);
355
356  if (::link(t.begin(), f.begin()) == -1)
357    return error_code(errno, system_category());
358
359  return error_code::success();
360}
361
362error_code create_symlink(const Twine &to, const Twine &from) {
363  // Get arguments.
364  SmallString<128> from_storage;
365  SmallString<128> to_storage;
366  StringRef f = from.toNullTerminatedStringRef(from_storage);
367  StringRef t = to.toNullTerminatedStringRef(to_storage);
368
369  if (::symlink(t.begin(), f.begin()) == -1)
370    return error_code(errno, system_category());
371
372  return error_code::success();
373}
374
375error_code remove(const Twine &path, bool &existed) {
376  SmallString<128> path_storage;
377  StringRef p = path.toNullTerminatedStringRef(path_storage);
378
379  struct stat buf;
380  if (stat(p.begin(), &buf) != 0) {
381    if (errno != errc::no_such_file_or_directory)
382      return error_code(errno, system_category());
383    existed = false;
384    return error_code::success();
385  }
386
387  // Note: this check catches strange situations. In all cases, LLVM should
388  // only be involved in the creation and deletion of regular files.  This
389  // check ensures that what we're trying to erase is a regular file. It
390  // effectively prevents LLVM from erasing things like /dev/null, any block
391  // special file, or other things that aren't "regular" files.
392  if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode))
393    return make_error_code(errc::operation_not_permitted);
394
395  if (::remove(p.begin()) == -1) {
396    if (errno != errc::no_such_file_or_directory)
397      return error_code(errno, system_category());
398    existed = false;
399  } else
400    existed = true;
401
402  return error_code::success();
403}
404
405error_code rename(const Twine &from, const Twine &to) {
406  // Get arguments.
407  SmallString<128> from_storage;
408  SmallString<128> to_storage;
409  StringRef f = from.toNullTerminatedStringRef(from_storage);
410  StringRef t = to.toNullTerminatedStringRef(to_storage);
411
412  if (::rename(f.begin(), t.begin()) == -1)
413    return error_code(errno, system_category());
414
415  return error_code::success();
416}
417
418error_code resize_file(const Twine &path, uint64_t size) {
419  SmallString<128> path_storage;
420  StringRef p = path.toNullTerminatedStringRef(path_storage);
421
422  if (::truncate(p.begin(), size) == -1)
423    return error_code(errno, system_category());
424
425  return error_code::success();
426}
427
428error_code exists(const Twine &path, bool &result) {
429  SmallString<128> path_storage;
430  StringRef p = path.toNullTerminatedStringRef(path_storage);
431
432  if (::access(p.begin(), F_OK) == -1) {
433    if (errno != errc::no_such_file_or_directory)
434      return error_code(errno, system_category());
435    result = false;
436  } else
437    result = true;
438
439  return error_code::success();
440}
441
442bool can_write(const Twine &Path) {
443  SmallString<128> PathStorage;
444  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
445  return 0 == access(P.begin(), W_OK);
446}
447
448bool can_execute(const Twine &Path) {
449  SmallString<128> PathStorage;
450  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
451
452  if (0 != access(P.begin(), R_OK | X_OK))
453    return false;
454  struct stat buf;
455  if (0 != stat(P.begin(), &buf))
456    return false;
457  if (!S_ISREG(buf.st_mode))
458    return false;
459  return true;
460}
461
462bool equivalent(file_status A, file_status B) {
463  assert(status_known(A) && status_known(B));
464  return A.fs_st_dev == B.fs_st_dev &&
465         A.fs_st_ino == B.fs_st_ino;
466}
467
468error_code equivalent(const Twine &A, const Twine &B, bool &result) {
469  file_status fsA, fsB;
470  if (error_code ec = status(A, fsA)) return ec;
471  if (error_code ec = status(B, fsB)) return ec;
472  result = equivalent(fsA, fsB);
473  return error_code::success();
474}
475
476static error_code fillStatus(int StatRet, const struct stat &Status,
477                             file_status &Result) {
478  if (StatRet != 0) {
479    error_code ec(errno, system_category());
480    if (ec == errc::no_such_file_or_directory)
481      Result = file_status(file_type::file_not_found);
482    else
483      Result = file_status(file_type::status_error);
484    return ec;
485  }
486
487  file_type Type = file_type::type_unknown;
488
489  if (S_ISDIR(Status.st_mode))
490    Type = file_type::directory_file;
491  else if (S_ISREG(Status.st_mode))
492    Type = file_type::regular_file;
493  else if (S_ISBLK(Status.st_mode))
494    Type = file_type::block_file;
495  else if (S_ISCHR(Status.st_mode))
496    Type = file_type::character_file;
497  else if (S_ISFIFO(Status.st_mode))
498    Type = file_type::fifo_file;
499  else if (S_ISSOCK(Status.st_mode))
500    Type = file_type::socket_file;
501
502  perms Perms = static_cast<perms>(Status.st_mode);
503  Result =
504      file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_mtime,
505                  Status.st_uid, Status.st_gid, Status.st_size);
506
507  return error_code::success();
508}
509
510error_code status(const Twine &Path, file_status &Result) {
511  SmallString<128> PathStorage;
512  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
513
514  struct stat Status;
515  int StatRet = ::stat(P.begin(), &Status);
516  return fillStatus(StatRet, Status, Result);
517}
518
519error_code status(int FD, file_status &Result) {
520  struct stat Status;
521  int StatRet = ::fstat(FD, &Status);
522  return fillStatus(StatRet, Status, Result);
523}
524
525error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
526#if defined(HAVE_FUTIMENS)
527  timespec Times[2];
528  Times[0].tv_sec = Time.toPosixTime();
529  Times[0].tv_nsec = 0;
530  Times[1] = Times[0];
531  if (::futimens(FD, Times))
532#elif defined(HAVE_FUTIMES)
533  timeval Times[2];
534  Times[0].tv_sec = Time.toPosixTime();
535  Times[0].tv_usec = 0;
536  Times[1] = Times[0];
537  if (::futimes(FD, Times))
538#else
539#error Missing futimes() and futimens()
540#endif
541    return error_code(errno, system_category());
542  return error_code::success();
543}
544
545error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
546  AutoFD ScopedFD(FD);
547  if (!CloseFD)
548    ScopedFD.take();
549
550  // Figure out how large the file is.
551  struct stat FileInfo;
552  if (fstat(FD, &FileInfo) == -1)
553    return error_code(errno, system_category());
554  uint64_t FileSize = FileInfo.st_size;
555
556  if (Size == 0)
557    Size = FileSize;
558  else if (FileSize < Size) {
559    // We need to grow the file.
560    if (ftruncate(FD, Size) == -1)
561      return error_code(errno, system_category());
562  }
563
564  int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
565  int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
566#ifdef MAP_FILE
567  flags |= MAP_FILE;
568#endif
569  Mapping = ::mmap(0, Size, prot, flags, FD, Offset);
570  if (Mapping == MAP_FAILED)
571    return error_code(errno, system_category());
572  return error_code::success();
573}
574
575mapped_file_region::mapped_file_region(const Twine &path,
576                                       mapmode mode,
577                                       uint64_t length,
578                                       uint64_t offset,
579                                       error_code &ec)
580  : Mode(mode)
581  , Size(length)
582  , Mapping() {
583  // Make sure that the requested size fits within SIZE_T.
584  if (length > std::numeric_limits<size_t>::max()) {
585    ec = make_error_code(errc::invalid_argument);
586    return;
587  }
588
589  SmallString<128> path_storage;
590  StringRef name = path.toNullTerminatedStringRef(path_storage);
591  int oflags = (mode == readonly) ? O_RDONLY : O_RDWR;
592  int ofd = ::open(name.begin(), oflags);
593  if (ofd == -1) {
594    ec = error_code(errno, system_category());
595    return;
596  }
597
598  ec = init(ofd, true, offset);
599  if (ec)
600    Mapping = 0;
601}
602
603mapped_file_region::mapped_file_region(int fd,
604                                       bool closefd,
605                                       mapmode mode,
606                                       uint64_t length,
607                                       uint64_t offset,
608                                       error_code &ec)
609  : Mode(mode)
610  , Size(length)
611  , Mapping() {
612  // Make sure that the requested size fits within SIZE_T.
613  if (length > std::numeric_limits<size_t>::max()) {
614    ec = make_error_code(errc::invalid_argument);
615    return;
616  }
617
618  ec = init(fd, closefd, offset);
619  if (ec)
620    Mapping = 0;
621}
622
623mapped_file_region::~mapped_file_region() {
624  if (Mapping)
625    ::munmap(Mapping, Size);
626}
627
628#if LLVM_HAS_RVALUE_REFERENCES
629mapped_file_region::mapped_file_region(mapped_file_region &&other)
630  : Mode(other.Mode), Size(other.Size), Mapping(other.Mapping) {
631  other.Mapping = 0;
632}
633#endif
634
635mapped_file_region::mapmode mapped_file_region::flags() const {
636  assert(Mapping && "Mapping failed but used anyway!");
637  return Mode;
638}
639
640uint64_t mapped_file_region::size() const {
641  assert(Mapping && "Mapping failed but used anyway!");
642  return Size;
643}
644
645char *mapped_file_region::data() const {
646  assert(Mapping && "Mapping failed but used anyway!");
647  assert(Mode != readonly && "Cannot get non const data for readonly mapping!");
648  return reinterpret_cast<char*>(Mapping);
649}
650
651const char *mapped_file_region::const_data() const {
652  assert(Mapping && "Mapping failed but used anyway!");
653  return reinterpret_cast<const char*>(Mapping);
654}
655
656int mapped_file_region::alignment() {
657  return process::get_self()->page_size();
658}
659
660error_code detail::directory_iterator_construct(detail::DirIterState &it,
661                                                StringRef path){
662  SmallString<128> path_null(path);
663  DIR *directory = ::opendir(path_null.c_str());
664  if (directory == 0)
665    return error_code(errno, system_category());
666
667  it.IterationHandle = reinterpret_cast<intptr_t>(directory);
668  // Add something for replace_filename to replace.
669  path::append(path_null, ".");
670  it.CurrentEntry = directory_entry(path_null.str());
671  return directory_iterator_increment(it);
672}
673
674error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
675  if (it.IterationHandle)
676    ::closedir(reinterpret_cast<DIR *>(it.IterationHandle));
677  it.IterationHandle = 0;
678  it.CurrentEntry = directory_entry();
679  return error_code::success();
680}
681
682error_code detail::directory_iterator_increment(detail::DirIterState &it) {
683  errno = 0;
684  dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
685  if (cur_dir == 0 && errno != 0) {
686    return error_code(errno, system_category());
687  } else if (cur_dir != 0) {
688    StringRef name(cur_dir->d_name, NAMLEN(cur_dir));
689    if ((name.size() == 1 && name[0] == '.') ||
690        (name.size() == 2 && name[0] == '.' && name[1] == '.'))
691      return directory_iterator_increment(it);
692    it.CurrentEntry.replace_filename(name);
693  } else
694    return directory_iterator_destruct(it);
695
696  return error_code::success();
697}
698
699error_code get_magic(const Twine &path, uint32_t len,
700                     SmallVectorImpl<char> &result) {
701  SmallString<128> PathStorage;
702  StringRef Path = path.toNullTerminatedStringRef(PathStorage);
703  result.set_size(0);
704
705  // Open path.
706  std::FILE *file = std::fopen(Path.data(), "rb");
707  if (file == 0)
708    return error_code(errno, system_category());
709
710  // Reserve storage.
711  result.reserve(len);
712
713  // Read magic!
714  size_t size = std::fread(result.data(), 1, len, file);
715  if (std::ferror(file) != 0) {
716    std::fclose(file);
717    return error_code(errno, system_category());
718  } else if (size != len) {
719    if (std::feof(file) != 0) {
720      std::fclose(file);
721      result.set_size(size);
722      return make_error_code(errc::value_too_large);
723    }
724  }
725  std::fclose(file);
726  result.set_size(size);
727  return error_code::success();
728}
729
730error_code map_file_pages(const Twine &path, off_t file_offset, size_t size,
731                                            bool map_writable, void *&result) {
732  SmallString<128> path_storage;
733  StringRef name = path.toNullTerminatedStringRef(path_storage);
734  int oflags = map_writable ? O_RDWR : O_RDONLY;
735  int ofd = ::open(name.begin(), oflags);
736  if ( ofd == -1 )
737    return error_code(errno, system_category());
738  AutoFD fd(ofd);
739  int flags = map_writable ? MAP_SHARED : MAP_PRIVATE;
740  int prot = map_writable ? (PROT_READ|PROT_WRITE) : PROT_READ;
741#ifdef MAP_FILE
742  flags |= MAP_FILE;
743#endif
744  result = ::mmap(0, size, prot, flags, fd, file_offset);
745  if (result == MAP_FAILED) {
746    return error_code(errno, system_category());
747  }
748
749  return error_code::success();
750}
751
752error_code unmap_file_pages(void *base, size_t size) {
753  if ( ::munmap(base, size) == -1 )
754    return error_code(errno, system_category());
755
756  return error_code::success();
757}
758
759error_code openFileForRead(const Twine &Name, int &ResultFD) {
760  SmallString<128> Storage;
761  StringRef P = Name.toNullTerminatedStringRef(Storage);
762  while ((ResultFD = open(P.begin(), O_RDONLY)) < 0) {
763    if (errno != EINTR)
764      return error_code(errno, system_category());
765  }
766  return error_code::success();
767}
768
769error_code openFileForWrite(const Twine &Name, int &ResultFD,
770                            sys::fs::OpenFlags Flags, unsigned Mode) {
771  // Verify that we don't have both "append" and "excl".
772  assert((!(Flags & sys::fs::F_Excl) || !(Flags & sys::fs::F_Append)) &&
773         "Cannot specify both 'excl' and 'append' file creation flags!");
774
775  int OpenFlags = O_WRONLY | O_CREAT;
776
777  if (Flags & F_Append)
778    OpenFlags |= O_APPEND;
779  else
780    OpenFlags |= O_TRUNC;
781
782  if (Flags & F_Excl)
783    OpenFlags |= O_EXCL;
784
785  SmallString<128> Storage;
786  StringRef P = Name.toNullTerminatedStringRef(Storage);
787  while ((ResultFD = open(P.begin(), OpenFlags, Mode)) < 0) {
788    if (errno != EINTR)
789      return error_code(errno, system_category());
790  }
791  return error_code::success();
792}
793
794} // end namespace fs
795} // end namespace sys
796} // end namespace llvm
797