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__) || defined(__DragonFly__)
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(__DragonFly__) || \
255      defined(__FreeBSD_kernel__)
256  char exe_path[PATH_MAX];
257
258  if (getprogpath(exe_path, argv0) != NULL)
259    return exe_path;
260#elif defined(__linux__) || defined(__CYGWIN__)
261  char exe_path[MAXPATHLEN];
262  StringRef aPath("/proc/self/exe");
263  if (sys::fs::exists(aPath)) {
264      // /proc is not always mounted under Linux (chroot for example).
265      ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path));
266      if (len >= 0)
267          return StringRef(exe_path, len);
268  } else {
269      // Fall back to the classical detection.
270      if (getprogpath(exe_path, argv0) != NULL)
271          return exe_path;
272  }
273#elif defined(HAVE_DLFCN_H)
274  // Use dladdr to get executable path if available.
275  Dl_info DLInfo;
276  int err = dladdr(MainAddr, &DLInfo);
277  if (err == 0)
278    return "";
279
280  // If the filename is a symlink, we need to resolve and return the location of
281  // the actual executable.
282  char link_path[MAXPATHLEN];
283  if (realpath(DLInfo.dli_fname, link_path))
284    return link_path;
285#else
286#error GetMainExecutable is not implemented on this host yet.
287#endif
288  return "";
289}
290
291TimeValue file_status::getLastModificationTime() const {
292  TimeValue Ret;
293  Ret.fromEpochTime(fs_st_mtime);
294  return Ret;
295}
296
297UniqueID file_status::getUniqueID() const {
298  return UniqueID(fs_st_dev, fs_st_ino);
299}
300
301error_code current_path(SmallVectorImpl<char> &result) {
302  result.clear();
303
304  const char *pwd = ::getenv("PWD");
305  llvm::sys::fs::file_status PWDStatus, DotStatus;
306  if (pwd && llvm::sys::path::is_absolute(pwd) &&
307      !llvm::sys::fs::status(pwd, PWDStatus) &&
308      !llvm::sys::fs::status(".", DotStatus) &&
309      PWDStatus.getUniqueID() == DotStatus.getUniqueID()) {
310    result.append(pwd, pwd + strlen(pwd));
311    return error_code::success();
312  }
313
314#ifdef MAXPATHLEN
315  result.reserve(MAXPATHLEN);
316#else
317// For GNU Hurd
318  result.reserve(1024);
319#endif
320
321  while (true) {
322    if (::getcwd(result.data(), result.capacity()) == 0) {
323      // See if there was a real error.
324      if (errno != errc::not_enough_memory)
325        return error_code(errno, system_category());
326      // Otherwise there just wasn't enough space.
327      result.reserve(result.capacity() * 2);
328    } else
329      break;
330  }
331
332  result.set_size(strlen(result.data()));
333  return error_code::success();
334}
335
336error_code create_directory(const Twine &path, bool &existed) {
337  SmallString<128> path_storage;
338  StringRef p = path.toNullTerminatedStringRef(path_storage);
339
340  if (::mkdir(p.begin(), S_IRWXU | S_IRWXG) == -1) {
341    if (errno != errc::file_exists)
342      return error_code(errno, system_category());
343    existed = true;
344  } else
345    existed = false;
346
347  return error_code::success();
348}
349
350error_code create_hard_link(const Twine &to, const Twine &from) {
351  // Get arguments.
352  SmallString<128> from_storage;
353  SmallString<128> to_storage;
354  StringRef f = from.toNullTerminatedStringRef(from_storage);
355  StringRef t = to.toNullTerminatedStringRef(to_storage);
356
357  if (::link(t.begin(), f.begin()) == -1)
358    return error_code(errno, system_category());
359
360  return error_code::success();
361}
362
363error_code create_symlink(const Twine &to, const Twine &from) {
364  // Get arguments.
365  SmallString<128> from_storage;
366  SmallString<128> to_storage;
367  StringRef f = from.toNullTerminatedStringRef(from_storage);
368  StringRef t = to.toNullTerminatedStringRef(to_storage);
369
370  if (::symlink(t.begin(), f.begin()) == -1)
371    return error_code(errno, system_category());
372
373  return error_code::success();
374}
375
376error_code remove(const Twine &path, bool &existed) {
377  SmallString<128> path_storage;
378  StringRef p = path.toNullTerminatedStringRef(path_storage);
379
380  struct stat buf;
381  if (stat(p.begin(), &buf) != 0) {
382    if (errno != errc::no_such_file_or_directory)
383      return error_code(errno, system_category());
384    existed = false;
385    return error_code::success();
386  }
387
388  // Note: this check catches strange situations. In all cases, LLVM should
389  // only be involved in the creation and deletion of regular files.  This
390  // check ensures that what we're trying to erase is a regular file. It
391  // effectively prevents LLVM from erasing things like /dev/null, any block
392  // special file, or other things that aren't "regular" files.
393  if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode))
394    return make_error_code(errc::operation_not_permitted);
395
396  if (::remove(p.begin()) == -1) {
397    if (errno != errc::no_such_file_or_directory)
398      return error_code(errno, system_category());
399    existed = false;
400  } else
401    existed = true;
402
403  return error_code::success();
404}
405
406error_code rename(const Twine &from, const Twine &to) {
407  // Get arguments.
408  SmallString<128> from_storage;
409  SmallString<128> to_storage;
410  StringRef f = from.toNullTerminatedStringRef(from_storage);
411  StringRef t = to.toNullTerminatedStringRef(to_storage);
412
413  if (::rename(f.begin(), t.begin()) == -1)
414    return error_code(errno, system_category());
415
416  return error_code::success();
417}
418
419error_code resize_file(const Twine &path, uint64_t size) {
420  SmallString<128> path_storage;
421  StringRef p = path.toNullTerminatedStringRef(path_storage);
422
423  if (::truncate(p.begin(), size) == -1)
424    return error_code(errno, system_category());
425
426  return error_code::success();
427}
428
429error_code exists(const Twine &path, bool &result) {
430  SmallString<128> path_storage;
431  StringRef p = path.toNullTerminatedStringRef(path_storage);
432
433  if (::access(p.begin(), F_OK) == -1) {
434    if (errno != errc::no_such_file_or_directory)
435      return error_code(errno, system_category());
436    result = false;
437  } else
438    result = true;
439
440  return error_code::success();
441}
442
443bool can_write(const Twine &Path) {
444  SmallString<128> PathStorage;
445  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
446  return 0 == access(P.begin(), W_OK);
447}
448
449bool can_execute(const Twine &Path) {
450  SmallString<128> PathStorage;
451  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
452
453  if (0 != access(P.begin(), R_OK | X_OK))
454    return false;
455  struct stat buf;
456  if (0 != stat(P.begin(), &buf))
457    return false;
458  if (!S_ISREG(buf.st_mode))
459    return false;
460  return true;
461}
462
463bool equivalent(file_status A, file_status B) {
464  assert(status_known(A) && status_known(B));
465  return A.fs_st_dev == B.fs_st_dev &&
466         A.fs_st_ino == B.fs_st_ino;
467}
468
469error_code equivalent(const Twine &A, const Twine &B, bool &result) {
470  file_status fsA, fsB;
471  if (error_code ec = status(A, fsA)) return ec;
472  if (error_code ec = status(B, fsB)) return ec;
473  result = equivalent(fsA, fsB);
474  return error_code::success();
475}
476
477static error_code fillStatus(int StatRet, const struct stat &Status,
478                             file_status &Result) {
479  if (StatRet != 0) {
480    error_code ec(errno, system_category());
481    if (ec == errc::no_such_file_or_directory)
482      Result = file_status(file_type::file_not_found);
483    else
484      Result = file_status(file_type::status_error);
485    return ec;
486  }
487
488  file_type Type = file_type::type_unknown;
489
490  if (S_ISDIR(Status.st_mode))
491    Type = file_type::directory_file;
492  else if (S_ISREG(Status.st_mode))
493    Type = file_type::regular_file;
494  else if (S_ISBLK(Status.st_mode))
495    Type = file_type::block_file;
496  else if (S_ISCHR(Status.st_mode))
497    Type = file_type::character_file;
498  else if (S_ISFIFO(Status.st_mode))
499    Type = file_type::fifo_file;
500  else if (S_ISSOCK(Status.st_mode))
501    Type = file_type::socket_file;
502
503  perms Perms = static_cast<perms>(Status.st_mode);
504  Result =
505      file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_mtime,
506                  Status.st_uid, Status.st_gid, Status.st_size);
507
508  return error_code::success();
509}
510
511error_code status(const Twine &Path, file_status &Result) {
512  SmallString<128> PathStorage;
513  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
514
515  struct stat Status;
516  int StatRet = ::stat(P.begin(), &Status);
517  return fillStatus(StatRet, Status, Result);
518}
519
520error_code status(int FD, file_status &Result) {
521  struct stat Status;
522  int StatRet = ::fstat(FD, &Status);
523  return fillStatus(StatRet, Status, Result);
524}
525
526error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
527#if defined(HAVE_FUTIMENS)
528  timespec Times[2];
529  Times[0].tv_sec = Time.toPosixTime();
530  Times[0].tv_nsec = 0;
531  Times[1] = Times[0];
532  if (::futimens(FD, Times))
533#elif defined(HAVE_FUTIMES)
534  timeval Times[2];
535  Times[0].tv_sec = Time.toPosixTime();
536  Times[0].tv_usec = 0;
537  Times[1] = Times[0];
538  if (::futimes(FD, Times))
539#else
540#error Missing futimes() and futimens()
541#endif
542    return error_code(errno, system_category());
543  return error_code::success();
544}
545
546error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
547  AutoFD ScopedFD(FD);
548  if (!CloseFD)
549    ScopedFD.take();
550
551  // Figure out how large the file is.
552  struct stat FileInfo;
553  if (fstat(FD, &FileInfo) == -1)
554    return error_code(errno, system_category());
555  uint64_t FileSize = FileInfo.st_size;
556
557  if (Size == 0)
558    Size = FileSize;
559  else if (FileSize < Size) {
560    // We need to grow the file.
561    if (ftruncate(FD, Size) == -1)
562      return error_code(errno, system_category());
563  }
564
565#if !defined(__minix)
566  int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
567#else
568  int flags = MAP_PRIVATE;
569#endif /* ! defined(__minix) */
570  int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
571#ifdef MAP_FILE
572  flags |= MAP_FILE;
573#endif
574  Mapping = ::mmap(0, Size, prot, flags, FD, Offset);
575  if (Mapping == MAP_FAILED)
576    return error_code(errno, system_category());
577  return error_code::success();
578}
579
580mapped_file_region::mapped_file_region(const Twine &path,
581                                       mapmode mode,
582                                       uint64_t length,
583                                       uint64_t offset,
584                                       error_code &ec)
585  : Mode(mode)
586  , Size(length)
587  , Mapping() {
588  // Make sure that the requested size fits within SIZE_T.
589  if (length > std::numeric_limits<size_t>::max()) {
590    ec = make_error_code(errc::invalid_argument);
591    return;
592  }
593
594  SmallString<128> path_storage;
595  StringRef name = path.toNullTerminatedStringRef(path_storage);
596  int oflags = (mode == readonly) ? O_RDONLY : O_RDWR;
597  int ofd = ::open(name.begin(), oflags);
598  if (ofd == -1) {
599    ec = error_code(errno, system_category());
600    return;
601  }
602
603  ec = init(ofd, true, offset);
604  if (ec)
605    Mapping = 0;
606}
607
608mapped_file_region::mapped_file_region(int fd,
609                                       bool closefd,
610                                       mapmode mode,
611                                       uint64_t length,
612                                       uint64_t offset,
613                                       error_code &ec)
614  : Mode(mode)
615  , Size(length)
616  , Mapping() {
617  // Make sure that the requested size fits within SIZE_T.
618  if (length > std::numeric_limits<size_t>::max()) {
619    ec = make_error_code(errc::invalid_argument);
620    return;
621  }
622
623  ec = init(fd, closefd, offset);
624  if (ec)
625    Mapping = 0;
626}
627
628mapped_file_region::~mapped_file_region() {
629  if (Mapping)
630    ::munmap(Mapping, Size);
631}
632
633#if LLVM_HAS_RVALUE_REFERENCES
634mapped_file_region::mapped_file_region(mapped_file_region &&other)
635  : Mode(other.Mode), Size(other.Size), Mapping(other.Mapping) {
636  other.Mapping = 0;
637}
638#endif
639
640mapped_file_region::mapmode mapped_file_region::flags() const {
641  assert(Mapping && "Mapping failed but used anyway!");
642  return Mode;
643}
644
645uint64_t mapped_file_region::size() const {
646  assert(Mapping && "Mapping failed but used anyway!");
647  return Size;
648}
649
650char *mapped_file_region::data() const {
651  assert(Mapping && "Mapping failed but used anyway!");
652  assert(Mode != readonly && "Cannot get non const data for readonly mapping!");
653  return reinterpret_cast<char*>(Mapping);
654}
655
656const char *mapped_file_region::const_data() const {
657  assert(Mapping && "Mapping failed but used anyway!");
658  return reinterpret_cast<const char*>(Mapping);
659}
660
661int mapped_file_region::alignment() {
662  return process::get_self()->page_size();
663}
664
665error_code detail::directory_iterator_construct(detail::DirIterState &it,
666                                                StringRef path){
667  SmallString<128> path_null(path);
668  DIR *directory = ::opendir(path_null.c_str());
669  if (directory == 0)
670    return error_code(errno, system_category());
671
672  it.IterationHandle = reinterpret_cast<intptr_t>(directory);
673  // Add something for replace_filename to replace.
674  path::append(path_null, ".");
675  it.CurrentEntry = directory_entry(path_null.str());
676  return directory_iterator_increment(it);
677}
678
679error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
680  if (it.IterationHandle)
681    ::closedir(reinterpret_cast<DIR *>(it.IterationHandle));
682  it.IterationHandle = 0;
683  it.CurrentEntry = directory_entry();
684  return error_code::success();
685}
686
687error_code detail::directory_iterator_increment(detail::DirIterState &it) {
688  errno = 0;
689  dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
690  if (cur_dir == 0 && errno != 0) {
691    return error_code(errno, system_category());
692  } else if (cur_dir != 0) {
693    StringRef name(cur_dir->d_name, NAMLEN(cur_dir));
694    if ((name.size() == 1 && name[0] == '.') ||
695        (name.size() == 2 && name[0] == '.' && name[1] == '.'))
696      return directory_iterator_increment(it);
697    it.CurrentEntry.replace_filename(name);
698  } else
699    return directory_iterator_destruct(it);
700
701  return error_code::success();
702}
703
704error_code get_magic(const Twine &path, uint32_t len,
705                     SmallVectorImpl<char> &result) {
706  SmallString<128> PathStorage;
707  StringRef Path = path.toNullTerminatedStringRef(PathStorage);
708  result.set_size(0);
709
710  // Open path.
711  std::FILE *file = std::fopen(Path.data(), "rb");
712  if (file == 0)
713    return error_code(errno, system_category());
714
715  // Reserve storage.
716  result.reserve(len);
717
718  // Read magic!
719  size_t size = std::fread(result.data(), 1, len, file);
720  if (std::ferror(file) != 0) {
721    std::fclose(file);
722    return error_code(errno, system_category());
723  } else if (size != len) {
724    if (std::feof(file) != 0) {
725      std::fclose(file);
726      result.set_size(size);
727      return make_error_code(errc::value_too_large);
728    }
729  }
730  std::fclose(file);
731  result.set_size(size);
732  return error_code::success();
733}
734
735error_code map_file_pages(const Twine &path, off_t file_offset, size_t size,
736                                            bool map_writable, void *&result) {
737  SmallString<128> path_storage;
738  StringRef name = path.toNullTerminatedStringRef(path_storage);
739  int oflags = map_writable ? O_RDWR : O_RDONLY;
740  int ofd = ::open(name.begin(), oflags);
741  if ( ofd == -1 )
742    return error_code(errno, system_category());
743  AutoFD fd(ofd);
744#if !defined(__minix)
745  int flags = map_writable ? MAP_SHARED : MAP_PRIVATE;
746#else
747  int flags = MAP_PRIVATE;
748#endif /* !defined(__minix) */
749  int prot = map_writable ? (PROT_READ|PROT_WRITE) : PROT_READ;
750#ifdef MAP_FILE
751  flags |= MAP_FILE;
752#endif
753  result = ::mmap(0, size, prot, flags, fd, file_offset);
754  if (result == MAP_FAILED) {
755    return error_code(errno, system_category());
756  }
757
758  return error_code::success();
759}
760
761error_code unmap_file_pages(void *base, size_t size) {
762  if ( ::munmap(base, size) == -1 )
763    return error_code(errno, system_category());
764
765  return error_code::success();
766}
767
768error_code openFileForRead(const Twine &Name, int &ResultFD) {
769  SmallString<128> Storage;
770  StringRef P = Name.toNullTerminatedStringRef(Storage);
771  while ((ResultFD = open(P.begin(), O_RDONLY)) < 0) {
772    if (errno != EINTR)
773      return error_code(errno, system_category());
774  }
775  return error_code::success();
776}
777
778error_code openFileForWrite(const Twine &Name, int &ResultFD,
779                            sys::fs::OpenFlags Flags, unsigned Mode) {
780  // Verify that we don't have both "append" and "excl".
781  assert((!(Flags & sys::fs::F_Excl) || !(Flags & sys::fs::F_Append)) &&
782         "Cannot specify both 'excl' and 'append' file creation flags!");
783
784  int OpenFlags = O_WRONLY | O_CREAT;
785
786  if (Flags & F_Append)
787    OpenFlags |= O_APPEND;
788  else
789    OpenFlags |= O_TRUNC;
790
791  if (Flags & F_Excl)
792    OpenFlags |= O_EXCL;
793
794  SmallString<128> Storage;
795  StringRef P = Name.toNullTerminatedStringRef(Storage);
796  while ((ResultFD = open(P.begin(), OpenFlags, Mode)) < 0) {
797    if (errno != EINTR)
798      return error_code(errno, system_category());
799  }
800  return error_code::success();
801}
802
803} // end namespace fs
804} // end namespace sys
805} // end namespace llvm
806