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 <limits.h>
21#include <stdio.h>
22#if HAVE_SYS_STAT_H
23#include <sys/stat.h>
24#endif
25#if HAVE_FCNTL_H
26#include <fcntl.h>
27#endif
28#ifdef HAVE_UNISTD_H
29#include <unistd.h>
30#endif
31#ifdef HAVE_SYS_MMAN_H
32#include <sys/mman.h>
33#endif
34
35#include <dirent.h>
36#include <pwd.h>
37
38#ifdef __APPLE__
39#include <mach-o/dyld.h>
40#include <sys/attr.h>
41#endif
42
43// Both stdio.h and cstdio are included via different paths and
44// stdcxx's cstdio doesn't include stdio.h, so it doesn't #undef the macros
45// either.
46#undef ferror
47#undef feof
48
49// For GNU Hurd
50#if defined(__GNU__) && !defined(PATH_MAX)
51# define PATH_MAX 4096
52#endif
53
54#include <sys/types.h>
55#if !defined(__APPLE__) && !defined(__OpenBSD__) && !defined(__FreeBSD__) &&   \
56    !defined(__linux__)
57#include <sys/statvfs.h>
58#define STATVFS statvfs
59#define FSTATVFS fstatvfs
60#define STATVFS_F_FRSIZE(vfs) vfs.f_frsize
61#else
62#if defined(__OpenBSD__) || defined(__FreeBSD__)
63#include <sys/mount.h>
64#include <sys/param.h>
65#elif defined(__linux__)
66#if defined(HAVE_LINUX_MAGIC_H)
67#include <linux/magic.h>
68#else
69#if defined(HAVE_LINUX_NFS_FS_H)
70#include <linux/nfs_fs.h>
71#endif
72#if defined(HAVE_LINUX_SMB_H)
73#include <linux/smb.h>
74#endif
75#endif
76#include <sys/vfs.h>
77#else
78#include <sys/mount.h>
79#endif
80#define STATVFS statfs
81#define FSTATVFS fstatfs
82#define STATVFS_F_FRSIZE(vfs) static_cast<uint64_t>(vfs.f_bsize)
83#endif
84
85#if defined(__NetBSD__)
86#define STATVFS_F_FLAG(vfs) (vfs).f_flag
87#else
88#define STATVFS_F_FLAG(vfs) (vfs).f_flags
89#endif
90
91using namespace llvm;
92
93namespace llvm {
94namespace sys  {
95namespace fs {
96
97const file_t kInvalidFile = -1;
98
99#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) ||     \
100    defined(__minix) || defined(__FreeBSD_kernel__) || defined(__linux__) ||   \
101    defined(__CYGWIN__) || defined(__DragonFly__) || defined(_AIX)
102static int
103test_dir(char ret[PATH_MAX], const char *dir, const char *bin)
104{
105  struct stat sb;
106  char fullpath[PATH_MAX];
107
108  snprintf(fullpath, PATH_MAX, "%s/%s", dir, bin);
109  if (!realpath(fullpath, ret))
110    return 1;
111  if (stat(fullpath, &sb) != 0)
112    return 1;
113
114  return 0;
115}
116
117static char *
118getprogpath(char ret[PATH_MAX], const char *bin)
119{
120  char *pv, *s, *t;
121
122  /* First approach: absolute path. */
123  if (bin[0] == '/') {
124    if (test_dir(ret, "/", bin) == 0)
125      return ret;
126    return nullptr;
127  }
128
129  /* Second approach: relative path. */
130  if (strchr(bin, '/')) {
131    char cwd[PATH_MAX];
132    if (!getcwd(cwd, PATH_MAX))
133      return nullptr;
134    if (test_dir(ret, cwd, bin) == 0)
135      return ret;
136    return nullptr;
137  }
138
139  /* Third approach: $PATH */
140  if ((pv = getenv("PATH")) == nullptr)
141    return nullptr;
142  s = pv = strdup(pv);
143  if (!pv)
144    return nullptr;
145  while ((t = strsep(&s, ":")) != nullptr) {
146    if (test_dir(ret, t, bin) == 0) {
147      free(pv);
148      return ret;
149    }
150  }
151  free(pv);
152  return nullptr;
153}
154#endif // __FreeBSD__ || __NetBSD__ || __FreeBSD_kernel__
155
156/// GetMainExecutable - Return the path to the main executable, given the
157/// value of argv[0] from program startup.
158std::string getMainExecutable(const char *argv0, void *MainAddr) {
159#if defined(__APPLE__)
160  // On OS X the executable path is saved to the stack by dyld. Reading it
161  // from there is much faster than calling dladdr, especially for large
162  // binaries with symbols.
163  char exe_path[MAXPATHLEN];
164  uint32_t size = sizeof(exe_path);
165  if (_NSGetExecutablePath(exe_path, &size) == 0) {
166    char link_path[MAXPATHLEN];
167    if (realpath(exe_path, link_path))
168      return link_path;
169  }
170#elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) ||   \
171    defined(__minix) || defined(__DragonFly__) ||                              \
172    defined(__FreeBSD_kernel__) || defined(_AIX)
173  char exe_path[PATH_MAX];
174
175  if (getprogpath(exe_path, argv0) != NULL)
176    return exe_path;
177#elif defined(__linux__) || defined(__CYGWIN__)
178  char exe_path[MAXPATHLEN];
179  StringRef aPath("/proc/self/exe");
180  if (sys::fs::exists(aPath)) {
181      // /proc is not always mounted under Linux (chroot for example).
182      ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path));
183      if (len >= 0)
184          return std::string(exe_path, len);
185  } else {
186      // Fall back to the classical detection.
187      if (getprogpath(exe_path, argv0))
188        return exe_path;
189  }
190#elif defined(HAVE_DLFCN_H) && defined(HAVE_DLADDR)
191  // Use dladdr to get executable path if available.
192  Dl_info DLInfo;
193  int err = dladdr(MainAddr, &DLInfo);
194  if (err == 0)
195    return "";
196
197  // If the filename is a symlink, we need to resolve and return the location of
198  // the actual executable.
199  char link_path[MAXPATHLEN];
200  if (realpath(DLInfo.dli_fname, link_path))
201    return link_path;
202#else
203#error GetMainExecutable is not implemented on this host yet.
204#endif
205  return "";
206}
207
208TimePoint<> basic_file_status::getLastAccessedTime() const {
209  return toTimePoint(fs_st_atime);
210}
211
212TimePoint<> basic_file_status::getLastModificationTime() const {
213  return toTimePoint(fs_st_mtime);
214}
215
216UniqueID file_status::getUniqueID() const {
217  return UniqueID(fs_st_dev, fs_st_ino);
218}
219
220uint32_t file_status::getLinkCount() const {
221  return fs_st_nlinks;
222}
223
224ErrorOr<space_info> disk_space(const Twine &Path) {
225  struct STATVFS Vfs;
226  if (::STATVFS(Path.str().c_str(), &Vfs))
227    return std::error_code(errno, std::generic_category());
228  auto FrSize = STATVFS_F_FRSIZE(Vfs);
229  space_info SpaceInfo;
230  SpaceInfo.capacity = static_cast<uint64_t>(Vfs.f_blocks) * FrSize;
231  SpaceInfo.free = static_cast<uint64_t>(Vfs.f_bfree) * FrSize;
232  SpaceInfo.available = static_cast<uint64_t>(Vfs.f_bavail) * FrSize;
233  return SpaceInfo;
234}
235
236std::error_code current_path(SmallVectorImpl<char> &result) {
237  result.clear();
238
239  const char *pwd = ::getenv("PWD");
240  llvm::sys::fs::file_status PWDStatus, DotStatus;
241  if (pwd && llvm::sys::path::is_absolute(pwd) &&
242      !llvm::sys::fs::status(pwd, PWDStatus) &&
243      !llvm::sys::fs::status(".", DotStatus) &&
244      PWDStatus.getUniqueID() == DotStatus.getUniqueID()) {
245    result.append(pwd, pwd + strlen(pwd));
246    return std::error_code();
247  }
248
249#ifdef MAXPATHLEN
250  result.reserve(MAXPATHLEN);
251#else
252// For GNU Hurd
253  result.reserve(1024);
254#endif
255
256  while (true) {
257    if (::getcwd(result.data(), result.capacity()) == nullptr) {
258      // See if there was a real error.
259      if (errno != ENOMEM)
260        return std::error_code(errno, std::generic_category());
261      // Otherwise there just wasn't enough space.
262      result.reserve(result.capacity() * 2);
263    } else
264      break;
265  }
266
267  result.set_size(strlen(result.data()));
268  return std::error_code();
269}
270
271std::error_code set_current_path(const Twine &path) {
272  SmallString<128> path_storage;
273  StringRef p = path.toNullTerminatedStringRef(path_storage);
274
275  if (::chdir(p.begin()) == -1)
276    return std::error_code(errno, std::generic_category());
277
278  return std::error_code();
279}
280
281std::error_code create_directory(const Twine &path, bool IgnoreExisting,
282                                 perms Perms) {
283  SmallString<128> path_storage;
284  StringRef p = path.toNullTerminatedStringRef(path_storage);
285
286  if (::mkdir(p.begin(), Perms) == -1) {
287    if (errno != EEXIST || !IgnoreExisting)
288      return std::error_code(errno, std::generic_category());
289  }
290
291  return std::error_code();
292}
293
294// Note that we are using symbolic link because hard links are not supported by
295// all filesystems (SMB doesn't).
296std::error_code create_link(const Twine &to, const Twine &from) {
297  // Get arguments.
298  SmallString<128> from_storage;
299  SmallString<128> to_storage;
300  StringRef f = from.toNullTerminatedStringRef(from_storage);
301  StringRef t = to.toNullTerminatedStringRef(to_storage);
302
303  if (::symlink(t.begin(), f.begin()) == -1)
304    return std::error_code(errno, std::generic_category());
305
306  return std::error_code();
307}
308
309std::error_code create_hard_link(const Twine &to, const Twine &from) {
310  // Get arguments.
311  SmallString<128> from_storage;
312  SmallString<128> to_storage;
313  StringRef f = from.toNullTerminatedStringRef(from_storage);
314  StringRef t = to.toNullTerminatedStringRef(to_storage);
315
316  if (::link(t.begin(), f.begin()) == -1)
317    return std::error_code(errno, std::generic_category());
318
319  return std::error_code();
320}
321
322std::error_code remove(const Twine &path, bool IgnoreNonExisting) {
323  SmallString<128> path_storage;
324  StringRef p = path.toNullTerminatedStringRef(path_storage);
325
326  struct stat buf;
327  if (lstat(p.begin(), &buf) != 0) {
328    if (errno != ENOENT || !IgnoreNonExisting)
329      return std::error_code(errno, std::generic_category());
330    return std::error_code();
331  }
332
333  // Note: this check catches strange situations. In all cases, LLVM should
334  // only be involved in the creation and deletion of regular files.  This
335  // check ensures that what we're trying to erase is a regular file. It
336  // effectively prevents LLVM from erasing things like /dev/null, any block
337  // special file, or other things that aren't "regular" files.
338  if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode) && !S_ISLNK(buf.st_mode))
339    return make_error_code(errc::operation_not_permitted);
340
341  if (::remove(p.begin()) == -1) {
342    if (errno != ENOENT || !IgnoreNonExisting)
343      return std::error_code(errno, std::generic_category());
344  }
345
346  return std::error_code();
347}
348
349static bool is_local_impl(struct STATVFS &Vfs) {
350#if defined(__linux__)
351#ifndef NFS_SUPER_MAGIC
352#define NFS_SUPER_MAGIC 0x6969
353#endif
354#ifndef SMB_SUPER_MAGIC
355#define SMB_SUPER_MAGIC 0x517B
356#endif
357#ifndef CIFS_MAGIC_NUMBER
358#define CIFS_MAGIC_NUMBER 0xFF534D42
359#endif
360  switch ((uint32_t)Vfs.f_type) {
361  case NFS_SUPER_MAGIC:
362  case SMB_SUPER_MAGIC:
363  case CIFS_MAGIC_NUMBER:
364    return false;
365  default:
366    return true;
367  }
368#elif defined(__CYGWIN__)
369  // Cygwin doesn't expose this information; would need to use Win32 API.
370  return false;
371#elif defined(__Fuchsia__)
372  // Fuchsia doesn't yet support remote filesystem mounts.
373  return true;
374#elif defined(__HAIKU__)
375  // Haiku doesn't expose this information.
376  return false;
377#elif defined(__sun)
378  // statvfs::f_basetype contains a null-terminated FSType name of the mounted target
379  StringRef fstype(Vfs.f_basetype);
380  // NFS is the only non-local fstype??
381  return !fstype.equals("nfs");
382#else
383  return !!(STATVFS_F_FLAG(Vfs) & MNT_LOCAL);
384#endif
385}
386
387std::error_code is_local(const Twine &Path, bool &Result) {
388  struct STATVFS Vfs;
389  if (::STATVFS(Path.str().c_str(), &Vfs))
390    return std::error_code(errno, std::generic_category());
391
392  Result = is_local_impl(Vfs);
393  return std::error_code();
394}
395
396std::error_code is_local(int FD, bool &Result) {
397  struct STATVFS Vfs;
398  if (::FSTATVFS(FD, &Vfs))
399    return std::error_code(errno, std::generic_category());
400
401  Result = is_local_impl(Vfs);
402  return std::error_code();
403}
404
405std::error_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 std::error_code(errno, std::generic_category());
414
415  return std::error_code();
416}
417
418std::error_code resize_file(int FD, uint64_t Size) {
419#if defined(HAVE_POSIX_FALLOCATE)
420  // If we have posix_fallocate use it. Unlike ftruncate it always allocates
421  // space, so we get an error if the disk is full.
422  if (int Err = ::posix_fallocate(FD, 0, Size)) {
423    if (Err != EINVAL && Err != EOPNOTSUPP)
424      return std::error_code(Err, std::generic_category());
425  }
426#endif
427  // Use ftruncate as a fallback. It may or may not allocate space. At least on
428  // OS X with HFS+ it does.
429  if (::ftruncate(FD, Size) == -1)
430    return std::error_code(errno, std::generic_category());
431
432  return std::error_code();
433}
434
435static int convertAccessMode(AccessMode Mode) {
436  switch (Mode) {
437  case AccessMode::Exist:
438    return F_OK;
439  case AccessMode::Write:
440    return W_OK;
441  case AccessMode::Execute:
442    return R_OK | X_OK; // scripts also need R_OK.
443  }
444  llvm_unreachable("invalid enum");
445}
446
447std::error_code access(const Twine &Path, AccessMode Mode) {
448  SmallString<128> PathStorage;
449  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
450
451  if (::access(P.begin(), convertAccessMode(Mode)) == -1)
452    return std::error_code(errno, std::generic_category());
453
454  if (Mode == AccessMode::Execute) {
455    // Don't say that directories are executable.
456    struct stat buf;
457    if (0 != stat(P.begin(), &buf))
458      return errc::permission_denied;
459    if (!S_ISREG(buf.st_mode))
460      return errc::permission_denied;
461  }
462
463  return std::error_code();
464}
465
466bool can_execute(const Twine &Path) {
467  return !access(Path, AccessMode::Execute);
468}
469
470bool equivalent(file_status A, file_status B) {
471  assert(status_known(A) && status_known(B));
472  return A.fs_st_dev == B.fs_st_dev &&
473         A.fs_st_ino == B.fs_st_ino;
474}
475
476std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
477  file_status fsA, fsB;
478  if (std::error_code ec = status(A, fsA))
479    return ec;
480  if (std::error_code ec = status(B, fsB))
481    return ec;
482  result = equivalent(fsA, fsB);
483  return std::error_code();
484}
485
486static void expandTildeExpr(SmallVectorImpl<char> &Path) {
487  StringRef PathStr(Path.begin(), Path.size());
488  if (PathStr.empty() || !PathStr.startswith("~"))
489    return;
490
491  PathStr = PathStr.drop_front();
492  StringRef Expr =
493      PathStr.take_until([](char c) { return path::is_separator(c); });
494  StringRef Remainder = PathStr.substr(Expr.size() + 1);
495  SmallString<128> Storage;
496  if (Expr.empty()) {
497    // This is just ~/..., resolve it to the current user's home dir.
498    if (!path::home_directory(Storage)) {
499      // For some reason we couldn't get the home directory.  Just exit.
500      return;
501    }
502
503    // Overwrite the first character and insert the rest.
504    Path[0] = Storage[0];
505    Path.insert(Path.begin() + 1, Storage.begin() + 1, Storage.end());
506    return;
507  }
508
509  // This is a string of the form ~username/, look up this user's entry in the
510  // password database.
511  struct passwd *Entry = nullptr;
512  std::string User = Expr.str();
513  Entry = ::getpwnam(User.c_str());
514
515  if (!Entry) {
516    // Unable to look up the entry, just return back the original path.
517    return;
518  }
519
520  Storage = Remainder;
521  Path.clear();
522  Path.append(Entry->pw_dir, Entry->pw_dir + strlen(Entry->pw_dir));
523  llvm::sys::path::append(Path, Storage);
524}
525
526static std::error_code fillStatus(int StatRet, const struct stat &Status,
527                                  file_status &Result) {
528  if (StatRet != 0) {
529    std::error_code ec(errno, std::generic_category());
530    if (ec == errc::no_such_file_or_directory)
531      Result = file_status(file_type::file_not_found);
532    else
533      Result = file_status(file_type::status_error);
534    return ec;
535  }
536
537  file_type Type = file_type::type_unknown;
538
539  if (S_ISDIR(Status.st_mode))
540    Type = file_type::directory_file;
541  else if (S_ISREG(Status.st_mode))
542    Type = file_type::regular_file;
543  else if (S_ISBLK(Status.st_mode))
544    Type = file_type::block_file;
545  else if (S_ISCHR(Status.st_mode))
546    Type = file_type::character_file;
547  else if (S_ISFIFO(Status.st_mode))
548    Type = file_type::fifo_file;
549  else if (S_ISSOCK(Status.st_mode))
550    Type = file_type::socket_file;
551  else if (S_ISLNK(Status.st_mode))
552    Type = file_type::symlink_file;
553
554  perms Perms = static_cast<perms>(Status.st_mode) & all_perms;
555  Result = file_status(Type, Perms, Status.st_dev, Status.st_nlink,
556                       Status.st_ino, Status.st_atime, Status.st_mtime,
557                       Status.st_uid, Status.st_gid, Status.st_size);
558
559  return std::error_code();
560}
561
562std::error_code status(const Twine &Path, file_status &Result, bool Follow) {
563  SmallString<128> PathStorage;
564  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
565
566  struct stat Status;
567  int StatRet = (Follow ? ::stat : ::lstat)(P.begin(), &Status);
568  return fillStatus(StatRet, Status, Result);
569}
570
571std::error_code status(int FD, file_status &Result) {
572  struct stat Status;
573  int StatRet = ::fstat(FD, &Status);
574  return fillStatus(StatRet, Status, Result);
575}
576
577std::error_code setPermissions(const Twine &Path, perms Permissions) {
578  SmallString<128> PathStorage;
579  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
580
581  if (::chmod(P.begin(), Permissions))
582    return std::error_code(errno, std::generic_category());
583  return std::error_code();
584}
585
586std::error_code setLastAccessAndModificationTime(int FD, TimePoint<> AccessTime,
587                                                 TimePoint<> ModificationTime) {
588#if defined(HAVE_FUTIMENS)
589  timespec Times[2];
590  Times[0] = sys::toTimeSpec(AccessTime);
591  Times[1] = sys::toTimeSpec(ModificationTime);
592  if (::futimens(FD, Times))
593    return std::error_code(errno, std::generic_category());
594  return std::error_code();
595#elif defined(HAVE_FUTIMES)
596  timeval Times[2];
597  Times[0] = sys::toTimeVal(
598      std::chrono::time_point_cast<std::chrono::microseconds>(AccessTime));
599  Times[1] =
600      sys::toTimeVal(std::chrono::time_point_cast<std::chrono::microseconds>(
601          ModificationTime));
602  if (::futimes(FD, Times))
603    return std::error_code(errno, std::generic_category());
604  return std::error_code();
605#else
606#warning Missing futimes() and futimens()
607  return make_error_code(errc::function_not_supported);
608#endif
609}
610
611std::error_code mapped_file_region::init(int FD, uint64_t Offset,
612                                         mapmode Mode) {
613  assert(Size != 0);
614
615  int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
616  int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
617#if defined(__APPLE__)
618  //----------------------------------------------------------------------
619  // Newer versions of MacOSX have a flag that will allow us to read from
620  // binaries whose code signature is invalid without crashing by using
621  // the MAP_RESILIENT_CODESIGN flag. Also if a file from removable media
622  // is mapped we can avoid crashing and return zeroes to any pages we try
623  // to read if the media becomes unavailable by using the
624  // MAP_RESILIENT_MEDIA flag.  These flags are only usable when mapping
625  // with PROT_READ, so take care not to specify them otherwise.
626  //----------------------------------------------------------------------
627  if (Mode == readonly) {
628#if defined(MAP_RESILIENT_CODESIGN)
629    flags |= MAP_RESILIENT_CODESIGN;
630#endif
631#if defined(MAP_RESILIENT_MEDIA)
632    flags |= MAP_RESILIENT_MEDIA;
633#endif
634  }
635#endif // #if defined (__APPLE__)
636
637  Mapping = ::mmap(nullptr, Size, prot, flags, FD, Offset);
638  if (Mapping == MAP_FAILED)
639    return std::error_code(errno, std::generic_category());
640  return std::error_code();
641}
642
643mapped_file_region::mapped_file_region(int fd, mapmode mode, size_t length,
644                                       uint64_t offset, std::error_code &ec)
645    : Size(length), Mapping(), Mode(mode) {
646  (void)Mode;
647  ec = init(fd, offset, mode);
648  if (ec)
649    Mapping = nullptr;
650}
651
652mapped_file_region::~mapped_file_region() {
653  if (Mapping)
654    ::munmap(Mapping, Size);
655}
656
657size_t mapped_file_region::size() const {
658  assert(Mapping && "Mapping failed but used anyway!");
659  return Size;
660}
661
662char *mapped_file_region::data() const {
663  assert(Mapping && "Mapping failed but used anyway!");
664  return reinterpret_cast<char*>(Mapping);
665}
666
667const char *mapped_file_region::const_data() const {
668  assert(Mapping && "Mapping failed but used anyway!");
669  return reinterpret_cast<const char*>(Mapping);
670}
671
672int mapped_file_region::alignment() {
673  return Process::getPageSize();
674}
675
676std::error_code detail::directory_iterator_construct(detail::DirIterState &it,
677                                                     StringRef path,
678                                                     bool follow_symlinks) {
679  SmallString<128> path_null(path);
680  DIR *directory = ::opendir(path_null.c_str());
681  if (!directory)
682    return std::error_code(errno, std::generic_category());
683
684  it.IterationHandle = reinterpret_cast<intptr_t>(directory);
685  // Add something for replace_filename to replace.
686  path::append(path_null, ".");
687  it.CurrentEntry = directory_entry(path_null.str(), follow_symlinks);
688  return directory_iterator_increment(it);
689}
690
691std::error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
692  if (it.IterationHandle)
693    ::closedir(reinterpret_cast<DIR *>(it.IterationHandle));
694  it.IterationHandle = 0;
695  it.CurrentEntry = directory_entry();
696  return std::error_code();
697}
698
699std::error_code detail::directory_iterator_increment(detail::DirIterState &it) {
700  errno = 0;
701  dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
702  if (cur_dir == nullptr && errno != 0) {
703    return std::error_code(errno, std::generic_category());
704  } else if (cur_dir != nullptr) {
705    StringRef name(cur_dir->d_name);
706    if ((name.size() == 1 && name[0] == '.') ||
707        (name.size() == 2 && name[0] == '.' && name[1] == '.'))
708      return directory_iterator_increment(it);
709    it.CurrentEntry.replace_filename(name);
710  } else
711    return directory_iterator_destruct(it);
712
713  return std::error_code();
714}
715
716ErrorOr<basic_file_status> directory_entry::status() const {
717  file_status s;
718  if (auto EC = fs::status(Path, s, FollowSymlinks))
719    return EC;
720  return s;
721}
722
723#if !defined(F_GETPATH)
724static bool hasProcSelfFD() {
725  // If we have a /proc filesystem mounted, we can quickly establish the
726  // real name of the file with readlink
727  static const bool Result = (::access("/proc/self/fd", R_OK) == 0);
728  return Result;
729}
730#endif
731
732static int nativeOpenFlags(CreationDisposition Disp, OpenFlags Flags,
733                           FileAccess Access) {
734  int Result = 0;
735  if (Access == FA_Read)
736    Result |= O_RDONLY;
737  else if (Access == FA_Write)
738    Result |= O_WRONLY;
739  else if (Access == (FA_Read | FA_Write))
740    Result |= O_RDWR;
741
742  // This is for compatibility with old code that assumed F_Append implied
743  // would open an existing file.  See Windows/Path.inc for a longer comment.
744  if (Flags & F_Append)
745    Disp = CD_OpenAlways;
746
747  if (Disp == CD_CreateNew) {
748    Result |= O_CREAT; // Create if it doesn't exist.
749    Result |= O_EXCL;  // Fail if it does.
750  } else if (Disp == CD_CreateAlways) {
751    Result |= O_CREAT; // Create if it doesn't exist.
752    Result |= O_TRUNC; // Truncate if it does.
753  } else if (Disp == CD_OpenAlways) {
754    Result |= O_CREAT; // Create if it doesn't exist.
755  } else if (Disp == CD_OpenExisting) {
756    // Nothing special, just don't add O_CREAT and we get these semantics.
757  }
758
759  if (Flags & F_Append)
760    Result |= O_APPEND;
761
762#ifdef O_CLOEXEC
763  if (!(Flags & OF_ChildInherit))
764    Result |= O_CLOEXEC;
765#endif
766
767  return Result;
768}
769
770std::error_code openFile(const Twine &Name, int &ResultFD,
771                         CreationDisposition Disp, FileAccess Access,
772                         OpenFlags Flags, unsigned Mode) {
773  int OpenFlags = nativeOpenFlags(Disp, Flags, Access);
774
775  SmallString<128> Storage;
776  StringRef P = Name.toNullTerminatedStringRef(Storage);
777  // Call ::open in a lambda to avoid overload resolution in RetryAfterSignal
778  // when open is overloaded, such as in Bionic.
779  auto Open = [&]() { return ::open(P.begin(), OpenFlags, Mode); };
780  if ((ResultFD = sys::RetryAfterSignal(-1, Open)) < 0)
781    return std::error_code(errno, std::generic_category());
782#ifndef O_CLOEXEC
783  if (!(Flags & OF_ChildInherit)) {
784    int r = fcntl(ResultFD, F_SETFD, FD_CLOEXEC);
785    (void)r;
786    assert(r == 0 && "fcntl(F_SETFD, FD_CLOEXEC) failed");
787  }
788#endif
789  return std::error_code();
790}
791
792Expected<int> openNativeFile(const Twine &Name, CreationDisposition Disp,
793                             FileAccess Access, OpenFlags Flags,
794                             unsigned Mode) {
795
796  int FD;
797  std::error_code EC = openFile(Name, FD, Disp, Access, Flags, Mode);
798  if (EC)
799    return errorCodeToError(EC);
800  return FD;
801}
802
803std::error_code openFileForRead(const Twine &Name, int &ResultFD,
804                                OpenFlags Flags,
805                                SmallVectorImpl<char> *RealPath) {
806  std::error_code EC =
807      openFile(Name, ResultFD, CD_OpenExisting, FA_Read, Flags, 0666);
808  if (EC)
809    return EC;
810
811  // Attempt to get the real name of the file, if the user asked
812  if(!RealPath)
813    return std::error_code();
814  RealPath->clear();
815#if defined(F_GETPATH)
816  // When F_GETPATH is availble, it is the quickest way to get
817  // the real path name.
818  char Buffer[MAXPATHLEN];
819  if (::fcntl(ResultFD, F_GETPATH, Buffer) != -1)
820    RealPath->append(Buffer, Buffer + strlen(Buffer));
821#else
822  char Buffer[PATH_MAX];
823  if (hasProcSelfFD()) {
824    char ProcPath[64];
825    snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", ResultFD);
826    ssize_t CharCount = ::readlink(ProcPath, Buffer, sizeof(Buffer));
827    if (CharCount > 0)
828      RealPath->append(Buffer, Buffer + CharCount);
829  } else {
830    SmallString<128> Storage;
831    StringRef P = Name.toNullTerminatedStringRef(Storage);
832
833    // Use ::realpath to get the real path name
834    if (::realpath(P.begin(), Buffer) != nullptr)
835      RealPath->append(Buffer, Buffer + strlen(Buffer));
836  }
837#endif
838  return std::error_code();
839}
840
841Expected<file_t> openNativeFileForRead(const Twine &Name, OpenFlags Flags,
842                                       SmallVectorImpl<char> *RealPath) {
843  file_t ResultFD;
844  std::error_code EC = openFileForRead(Name, ResultFD, Flags, RealPath);
845  if (EC)
846    return errorCodeToError(EC);
847  return ResultFD;
848}
849
850void closeFile(file_t &F) {
851  ::close(F);
852  F = kInvalidFile;
853}
854
855template <typename T>
856static std::error_code remove_directories_impl(const T &Entry,
857                                               bool IgnoreErrors) {
858  std::error_code EC;
859  directory_iterator Begin(Entry, EC, false);
860  directory_iterator End;
861  while (Begin != End) {
862    auto &Item = *Begin;
863    ErrorOr<basic_file_status> st = Item.status();
864    if (!st && !IgnoreErrors)
865      return st.getError();
866
867    if (is_directory(*st)) {
868      EC = remove_directories_impl(Item, IgnoreErrors);
869      if (EC && !IgnoreErrors)
870        return EC;
871    }
872
873    EC = fs::remove(Item.path(), true);
874    if (EC && !IgnoreErrors)
875      return EC;
876
877    Begin.increment(EC);
878    if (EC && !IgnoreErrors)
879      return EC;
880  }
881  return std::error_code();
882}
883
884std::error_code remove_directories(const Twine &path, bool IgnoreErrors) {
885  auto EC = remove_directories_impl(path, IgnoreErrors);
886  if (EC && !IgnoreErrors)
887    return EC;
888  EC = fs::remove(path, true);
889  if (EC && !IgnoreErrors)
890    return EC;
891  return std::error_code();
892}
893
894std::error_code real_path(const Twine &path, SmallVectorImpl<char> &dest,
895                          bool expand_tilde) {
896  dest.clear();
897  if (path.isTriviallyEmpty())
898    return std::error_code();
899
900  if (expand_tilde) {
901    SmallString<128> Storage;
902    path.toVector(Storage);
903    expandTildeExpr(Storage);
904    return real_path(Storage, dest, false);
905  }
906
907  SmallString<128> Storage;
908  StringRef P = path.toNullTerminatedStringRef(Storage);
909  char Buffer[PATH_MAX];
910  if (::realpath(P.begin(), Buffer) == nullptr)
911    return std::error_code(errno, std::generic_category());
912  dest.append(Buffer, Buffer + strlen(Buffer));
913  return std::error_code();
914}
915
916} // end namespace fs
917
918namespace path {
919
920bool home_directory(SmallVectorImpl<char> &result) {
921  char *RequestedDir = getenv("HOME");
922  if (!RequestedDir) {
923    struct passwd *pw = getpwuid(getuid());
924    if (pw && pw->pw_dir)
925      RequestedDir = pw->pw_dir;
926  }
927  if (!RequestedDir)
928    return false;
929
930  result.clear();
931  result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
932  return true;
933}
934
935static bool getDarwinConfDir(bool TempDir, SmallVectorImpl<char> &Result) {
936  #if defined(_CS_DARWIN_USER_TEMP_DIR) && defined(_CS_DARWIN_USER_CACHE_DIR)
937  // On Darwin, use DARWIN_USER_TEMP_DIR or DARWIN_USER_CACHE_DIR.
938  // macros defined in <unistd.h> on darwin >= 9
939  int ConfName = TempDir ? _CS_DARWIN_USER_TEMP_DIR
940                         : _CS_DARWIN_USER_CACHE_DIR;
941  size_t ConfLen = confstr(ConfName, nullptr, 0);
942  if (ConfLen > 0) {
943    do {
944      Result.resize(ConfLen);
945      ConfLen = confstr(ConfName, Result.data(), Result.size());
946    } while (ConfLen > 0 && ConfLen != Result.size());
947
948    if (ConfLen > 0) {
949      assert(Result.back() == 0);
950      Result.pop_back();
951      return true;
952    }
953
954    Result.clear();
955  }
956  #endif
957  return false;
958}
959
960static bool getUserCacheDir(SmallVectorImpl<char> &Result) {
961  // First try using XDG_CACHE_HOME env variable,
962  // as specified in XDG Base Directory Specification at
963  // http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
964  if (const char *XdgCacheDir = std::getenv("XDG_CACHE_HOME")) {
965    Result.clear();
966    Result.append(XdgCacheDir, XdgCacheDir + strlen(XdgCacheDir));
967    return true;
968  }
969
970  // Try Darwin configuration query
971  if (getDarwinConfDir(false, Result))
972    return true;
973
974  // Use "$HOME/.cache" if $HOME is available
975  if (home_directory(Result)) {
976    append(Result, ".cache");
977    return true;
978  }
979
980  return false;
981}
982
983static const char *getEnvTempDir() {
984  // Check whether the temporary directory is specified by an environment
985  // variable.
986  const char *EnvironmentVariables[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR"};
987  for (const char *Env : EnvironmentVariables) {
988    if (const char *Dir = std::getenv(Env))
989      return Dir;
990  }
991
992  return nullptr;
993}
994
995static const char *getDefaultTempDir(bool ErasedOnReboot) {
996#ifdef P_tmpdir
997  if ((bool)P_tmpdir)
998    return P_tmpdir;
999#endif
1000
1001  if (ErasedOnReboot)
1002    return "/tmp";
1003  return "/var/tmp";
1004}
1005
1006void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) {
1007  Result.clear();
1008
1009  if (ErasedOnReboot) {
1010    // There is no env variable for the cache directory.
1011    if (const char *RequestedDir = getEnvTempDir()) {
1012      Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
1013      return;
1014    }
1015  }
1016
1017  if (getDarwinConfDir(ErasedOnReboot, Result))
1018    return;
1019
1020  const char *RequestedDir = getDefaultTempDir(ErasedOnReboot);
1021  Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
1022}
1023
1024} // end namespace path
1025
1026} // end namespace sys
1027} // end namespace llvm
1028