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(__sun)
375  // statvfs::f_basetype contains a null-terminated FSType name of the mounted target
376  StringRef fstype(Vfs.f_basetype);
377  // NFS is the only non-local fstype??
378  return !fstype.equals("nfs");
379#else
380  return !!(STATVFS_F_FLAG(Vfs) & MNT_LOCAL);
381#endif
382}
383
384std::error_code is_local(const Twine &Path, bool &Result) {
385  struct STATVFS Vfs;
386  if (::STATVFS(Path.str().c_str(), &Vfs))
387    return std::error_code(errno, std::generic_category());
388
389  Result = is_local_impl(Vfs);
390  return std::error_code();
391}
392
393std::error_code is_local(int FD, bool &Result) {
394  struct STATVFS Vfs;
395  if (::FSTATVFS(FD, &Vfs))
396    return std::error_code(errno, std::generic_category());
397
398  Result = is_local_impl(Vfs);
399  return std::error_code();
400}
401
402std::error_code rename(const Twine &from, const Twine &to) {
403  // Get arguments.
404  SmallString<128> from_storage;
405  SmallString<128> to_storage;
406  StringRef f = from.toNullTerminatedStringRef(from_storage);
407  StringRef t = to.toNullTerminatedStringRef(to_storage);
408
409  if (::rename(f.begin(), t.begin()) == -1)
410    return std::error_code(errno, std::generic_category());
411
412  return std::error_code();
413}
414
415std::error_code resize_file(int FD, uint64_t Size) {
416#if defined(HAVE_POSIX_FALLOCATE)
417  // If we have posix_fallocate use it. Unlike ftruncate it always allocates
418  // space, so we get an error if the disk is full.
419  if (int Err = ::posix_fallocate(FD, 0, Size)) {
420    if (Err != EINVAL && Err != EOPNOTSUPP)
421      return std::error_code(Err, std::generic_category());
422  }
423#endif
424  // Use ftruncate as a fallback. It may or may not allocate space. At least on
425  // OS X with HFS+ it does.
426  if (::ftruncate(FD, Size) == -1)
427    return std::error_code(errno, std::generic_category());
428
429  return std::error_code();
430}
431
432static int convertAccessMode(AccessMode Mode) {
433  switch (Mode) {
434  case AccessMode::Exist:
435    return F_OK;
436  case AccessMode::Write:
437    return W_OK;
438  case AccessMode::Execute:
439    return R_OK | X_OK; // scripts also need R_OK.
440  }
441  llvm_unreachable("invalid enum");
442}
443
444std::error_code access(const Twine &Path, AccessMode Mode) {
445  SmallString<128> PathStorage;
446  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
447
448  if (::access(P.begin(), convertAccessMode(Mode)) == -1)
449    return std::error_code(errno, std::generic_category());
450
451  if (Mode == AccessMode::Execute) {
452    // Don't say that directories are executable.
453    struct stat buf;
454    if (0 != stat(P.begin(), &buf))
455      return errc::permission_denied;
456    if (!S_ISREG(buf.st_mode))
457      return errc::permission_denied;
458  }
459
460  return std::error_code();
461}
462
463bool can_execute(const Twine &Path) {
464  return !access(Path, AccessMode::Execute);
465}
466
467bool equivalent(file_status A, file_status B) {
468  assert(status_known(A) && status_known(B));
469  return A.fs_st_dev == B.fs_st_dev &&
470         A.fs_st_ino == B.fs_st_ino;
471}
472
473std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
474  file_status fsA, fsB;
475  if (std::error_code ec = status(A, fsA))
476    return ec;
477  if (std::error_code ec = status(B, fsB))
478    return ec;
479  result = equivalent(fsA, fsB);
480  return std::error_code();
481}
482
483static void expandTildeExpr(SmallVectorImpl<char> &Path) {
484  StringRef PathStr(Path.begin(), Path.size());
485  if (PathStr.empty() || !PathStr.startswith("~"))
486    return;
487
488  PathStr = PathStr.drop_front();
489  StringRef Expr =
490      PathStr.take_until([](char c) { return path::is_separator(c); });
491  StringRef Remainder = PathStr.substr(Expr.size() + 1);
492  SmallString<128> Storage;
493  if (Expr.empty()) {
494    // This is just ~/..., resolve it to the current user's home dir.
495    if (!path::home_directory(Storage)) {
496      // For some reason we couldn't get the home directory.  Just exit.
497      return;
498    }
499
500    // Overwrite the first character and insert the rest.
501    Path[0] = Storage[0];
502    Path.insert(Path.begin() + 1, Storage.begin() + 1, Storage.end());
503    return;
504  }
505
506  // This is a string of the form ~username/, look up this user's entry in the
507  // password database.
508  struct passwd *Entry = nullptr;
509  std::string User = Expr.str();
510  Entry = ::getpwnam(User.c_str());
511
512  if (!Entry) {
513    // Unable to look up the entry, just return back the original path.
514    return;
515  }
516
517  Storage = Remainder;
518  Path.clear();
519  Path.append(Entry->pw_dir, Entry->pw_dir + strlen(Entry->pw_dir));
520  llvm::sys::path::append(Path, Storage);
521}
522
523static std::error_code fillStatus(int StatRet, const struct stat &Status,
524                                  file_status &Result) {
525  if (StatRet != 0) {
526    std::error_code ec(errno, std::generic_category());
527    if (ec == errc::no_such_file_or_directory)
528      Result = file_status(file_type::file_not_found);
529    else
530      Result = file_status(file_type::status_error);
531    return ec;
532  }
533
534  file_type Type = file_type::type_unknown;
535
536  if (S_ISDIR(Status.st_mode))
537    Type = file_type::directory_file;
538  else if (S_ISREG(Status.st_mode))
539    Type = file_type::regular_file;
540  else if (S_ISBLK(Status.st_mode))
541    Type = file_type::block_file;
542  else if (S_ISCHR(Status.st_mode))
543    Type = file_type::character_file;
544  else if (S_ISFIFO(Status.st_mode))
545    Type = file_type::fifo_file;
546  else if (S_ISSOCK(Status.st_mode))
547    Type = file_type::socket_file;
548  else if (S_ISLNK(Status.st_mode))
549    Type = file_type::symlink_file;
550
551  perms Perms = static_cast<perms>(Status.st_mode) & all_perms;
552  Result = file_status(Type, Perms, Status.st_dev, Status.st_nlink,
553                       Status.st_ino, Status.st_atime, Status.st_mtime,
554                       Status.st_uid, Status.st_gid, Status.st_size);
555
556  return std::error_code();
557}
558
559std::error_code status(const Twine &Path, file_status &Result, bool Follow) {
560  SmallString<128> PathStorage;
561  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
562
563  struct stat Status;
564  int StatRet = (Follow ? ::stat : ::lstat)(P.begin(), &Status);
565  return fillStatus(StatRet, Status, Result);
566}
567
568std::error_code status(int FD, file_status &Result) {
569  struct stat Status;
570  int StatRet = ::fstat(FD, &Status);
571  return fillStatus(StatRet, Status, Result);
572}
573
574std::error_code setPermissions(const Twine &Path, perms Permissions) {
575  SmallString<128> PathStorage;
576  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
577
578  if (::chmod(P.begin(), Permissions))
579    return std::error_code(errno, std::generic_category());
580  return std::error_code();
581}
582
583std::error_code setLastModificationAndAccessTime(int FD, TimePoint<> Time) {
584#if defined(HAVE_FUTIMENS)
585  timespec Times[2];
586  Times[0] = Times[1] = sys::toTimeSpec(Time);
587  if (::futimens(FD, Times))
588    return std::error_code(errno, std::generic_category());
589  return std::error_code();
590#elif defined(HAVE_FUTIMES)
591  timeval Times[2];
592  Times[0] = Times[1] = sys::toTimeVal(
593      std::chrono::time_point_cast<std::chrono::microseconds>(Time));
594  if (::futimes(FD, Times))
595    return std::error_code(errno, std::generic_category());
596  return std::error_code();
597#else
598#warning Missing futimes() and futimens()
599  return make_error_code(errc::function_not_supported);
600#endif
601}
602
603std::error_code mapped_file_region::init(int FD, uint64_t Offset,
604                                         mapmode Mode) {
605  assert(Size != 0);
606
607  int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
608  int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
609#if defined(__APPLE__)
610  //----------------------------------------------------------------------
611  // Newer versions of MacOSX have a flag that will allow us to read from
612  // binaries whose code signature is invalid without crashing by using
613  // the MAP_RESILIENT_CODESIGN flag. Also if a file from removable media
614  // is mapped we can avoid crashing and return zeroes to any pages we try
615  // to read if the media becomes unavailable by using the
616  // MAP_RESILIENT_MEDIA flag.  These flags are only usable when mapping
617  // with PROT_READ, so take care not to specify them otherwise.
618  //----------------------------------------------------------------------
619  if (Mode == readonly) {
620#if defined(MAP_RESILIENT_CODESIGN)
621    flags |= MAP_RESILIENT_CODESIGN;
622#endif
623#if defined(MAP_RESILIENT_MEDIA)
624    flags |= MAP_RESILIENT_MEDIA;
625#endif
626  }
627#endif // #if defined (__APPLE__)
628
629  Mapping = ::mmap(nullptr, Size, prot, flags, FD, Offset);
630  if (Mapping == MAP_FAILED)
631    return std::error_code(errno, std::generic_category());
632  return std::error_code();
633}
634
635mapped_file_region::mapped_file_region(int fd, mapmode mode, size_t length,
636                                       uint64_t offset, std::error_code &ec)
637    : Size(length), Mapping(), Mode(mode) {
638  (void)Mode;
639  ec = init(fd, offset, mode);
640  if (ec)
641    Mapping = nullptr;
642}
643
644mapped_file_region::~mapped_file_region() {
645  if (Mapping)
646    ::munmap(Mapping, Size);
647}
648
649size_t mapped_file_region::size() const {
650  assert(Mapping && "Mapping failed but used anyway!");
651  return Size;
652}
653
654char *mapped_file_region::data() const {
655  assert(Mapping && "Mapping failed but used anyway!");
656  return reinterpret_cast<char*>(Mapping);
657}
658
659const char *mapped_file_region::const_data() const {
660  assert(Mapping && "Mapping failed but used anyway!");
661  return reinterpret_cast<const char*>(Mapping);
662}
663
664int mapped_file_region::alignment() {
665  return Process::getPageSize();
666}
667
668std::error_code detail::directory_iterator_construct(detail::DirIterState &it,
669                                                     StringRef path,
670                                                     bool follow_symlinks) {
671  SmallString<128> path_null(path);
672  DIR *directory = ::opendir(path_null.c_str());
673  if (!directory)
674    return std::error_code(errno, std::generic_category());
675
676  it.IterationHandle = reinterpret_cast<intptr_t>(directory);
677  // Add something for replace_filename to replace.
678  path::append(path_null, ".");
679  it.CurrentEntry = directory_entry(path_null.str(), follow_symlinks);
680  return directory_iterator_increment(it);
681}
682
683std::error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
684  if (it.IterationHandle)
685    ::closedir(reinterpret_cast<DIR *>(it.IterationHandle));
686  it.IterationHandle = 0;
687  it.CurrentEntry = directory_entry();
688  return std::error_code();
689}
690
691std::error_code detail::directory_iterator_increment(detail::DirIterState &it) {
692  errno = 0;
693  dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
694  if (cur_dir == nullptr && errno != 0) {
695    return std::error_code(errno, std::generic_category());
696  } else if (cur_dir != nullptr) {
697    StringRef name(cur_dir->d_name);
698    if ((name.size() == 1 && name[0] == '.') ||
699        (name.size() == 2 && name[0] == '.' && name[1] == '.'))
700      return directory_iterator_increment(it);
701    it.CurrentEntry.replace_filename(name);
702  } else
703    return directory_iterator_destruct(it);
704
705  return std::error_code();
706}
707
708ErrorOr<basic_file_status> directory_entry::status() const {
709  file_status s;
710  if (auto EC = fs::status(Path, s, FollowSymlinks))
711    return EC;
712  return s;
713}
714
715#if !defined(F_GETPATH)
716static bool hasProcSelfFD() {
717  // If we have a /proc filesystem mounted, we can quickly establish the
718  // real name of the file with readlink
719  static const bool Result = (::access("/proc/self/fd", R_OK) == 0);
720  return Result;
721}
722#endif
723
724static int nativeOpenFlags(CreationDisposition Disp, OpenFlags Flags,
725                           FileAccess Access) {
726  int Result = 0;
727  if (Access == FA_Read)
728    Result |= O_RDONLY;
729  else if (Access == FA_Write)
730    Result |= O_WRONLY;
731  else if (Access == (FA_Read | FA_Write))
732    Result |= O_RDWR;
733
734  // This is for compatibility with old code that assumed F_Append implied
735  // would open an existing file.  See Windows/Path.inc for a longer comment.
736  if (Flags & F_Append)
737    Disp = CD_OpenAlways;
738
739  if (Disp == CD_CreateNew) {
740    Result |= O_CREAT; // Create if it doesn't exist.
741    Result |= O_EXCL;  // Fail if it does.
742  } else if (Disp == CD_CreateAlways) {
743    Result |= O_CREAT; // Create if it doesn't exist.
744    Result |= O_TRUNC; // Truncate if it does.
745  } else if (Disp == CD_OpenAlways) {
746    Result |= O_CREAT; // Create if it doesn't exist.
747  } else if (Disp == CD_OpenExisting) {
748    // Nothing special, just don't add O_CREAT and we get these semantics.
749  }
750
751  if (Flags & F_Append)
752    Result |= O_APPEND;
753
754#ifdef O_CLOEXEC
755  if (!(Flags & OF_ChildInherit))
756    Result |= O_CLOEXEC;
757#endif
758
759  return Result;
760}
761
762std::error_code openFile(const Twine &Name, int &ResultFD,
763                         CreationDisposition Disp, FileAccess Access,
764                         OpenFlags Flags, unsigned Mode) {
765  int OpenFlags = nativeOpenFlags(Disp, Flags, Access);
766
767  SmallString<128> Storage;
768  StringRef P = Name.toNullTerminatedStringRef(Storage);
769  if ((ResultFD = sys::RetryAfterSignal(-1, ::open, P.begin(), OpenFlags, Mode)) <
770      0)
771    return std::error_code(errno, std::generic_category());
772#ifndef O_CLOEXEC
773  if (!(Flags & OF_ChildInherit)) {
774    int r = fcntl(ResultFD, F_SETFD, FD_CLOEXEC);
775    (void)r;
776    assert(r == 0 && "fcntl(F_SETFD, FD_CLOEXEC) failed");
777  }
778#endif
779  return std::error_code();
780}
781
782Expected<int> openNativeFile(const Twine &Name, CreationDisposition Disp,
783                             FileAccess Access, OpenFlags Flags,
784                             unsigned Mode) {
785
786  int FD;
787  std::error_code EC = openFile(Name, FD, Disp, Access, Flags, Mode);
788  if (EC)
789    return errorCodeToError(EC);
790  return FD;
791}
792
793std::error_code openFileForRead(const Twine &Name, int &ResultFD,
794                                OpenFlags Flags,
795                                SmallVectorImpl<char> *RealPath) {
796  std::error_code EC =
797      openFile(Name, ResultFD, CD_OpenExisting, FA_Read, Flags, 0666);
798  if (EC)
799    return EC;
800
801  // Attempt to get the real name of the file, if the user asked
802  if(!RealPath)
803    return std::error_code();
804  RealPath->clear();
805#if defined(F_GETPATH)
806  // When F_GETPATH is availble, it is the quickest way to get
807  // the real path name.
808  char Buffer[MAXPATHLEN];
809  if (::fcntl(ResultFD, F_GETPATH, Buffer) != -1)
810    RealPath->append(Buffer, Buffer + strlen(Buffer));
811#else
812  char Buffer[PATH_MAX];
813  if (hasProcSelfFD()) {
814    char ProcPath[64];
815    snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", ResultFD);
816    ssize_t CharCount = ::readlink(ProcPath, Buffer, sizeof(Buffer));
817    if (CharCount > 0)
818      RealPath->append(Buffer, Buffer + CharCount);
819  } else {
820    SmallString<128> Storage;
821    StringRef P = Name.toNullTerminatedStringRef(Storage);
822
823    // Use ::realpath to get the real path name
824    if (::realpath(P.begin(), Buffer) != nullptr)
825      RealPath->append(Buffer, Buffer + strlen(Buffer));
826  }
827#endif
828  return std::error_code();
829}
830
831Expected<file_t> openNativeFileForRead(const Twine &Name, OpenFlags Flags,
832                                       SmallVectorImpl<char> *RealPath) {
833  file_t ResultFD;
834  std::error_code EC = openFileForRead(Name, ResultFD, Flags, RealPath);
835  if (EC)
836    return errorCodeToError(EC);
837  return ResultFD;
838}
839
840void closeFile(file_t &F) {
841  ::close(F);
842  F = kInvalidFile;
843}
844
845template <typename T>
846static std::error_code remove_directories_impl(const T &Entry,
847                                               bool IgnoreErrors) {
848  std::error_code EC;
849  directory_iterator Begin(Entry, EC, false);
850  directory_iterator End;
851  while (Begin != End) {
852    auto &Item = *Begin;
853    ErrorOr<basic_file_status> st = Item.status();
854    if (!st && !IgnoreErrors)
855      return st.getError();
856
857    if (is_directory(*st)) {
858      EC = remove_directories_impl(Item, IgnoreErrors);
859      if (EC && !IgnoreErrors)
860        return EC;
861    }
862
863    EC = fs::remove(Item.path(), true);
864    if (EC && !IgnoreErrors)
865      return EC;
866
867    Begin.increment(EC);
868    if (EC && !IgnoreErrors)
869      return EC;
870  }
871  return std::error_code();
872}
873
874std::error_code remove_directories(const Twine &path, bool IgnoreErrors) {
875  auto EC = remove_directories_impl(path, IgnoreErrors);
876  if (EC && !IgnoreErrors)
877    return EC;
878  EC = fs::remove(path, true);
879  if (EC && !IgnoreErrors)
880    return EC;
881  return std::error_code();
882}
883
884std::error_code real_path(const Twine &path, SmallVectorImpl<char> &dest,
885                          bool expand_tilde) {
886  dest.clear();
887  if (path.isTriviallyEmpty())
888    return std::error_code();
889
890  if (expand_tilde) {
891    SmallString<128> Storage;
892    path.toVector(Storage);
893    expandTildeExpr(Storage);
894    return real_path(Storage, dest, false);
895  }
896
897  SmallString<128> Storage;
898  StringRef P = path.toNullTerminatedStringRef(Storage);
899  char Buffer[PATH_MAX];
900  if (::realpath(P.begin(), Buffer) == nullptr)
901    return std::error_code(errno, std::generic_category());
902  dest.append(Buffer, Buffer + strlen(Buffer));
903  return std::error_code();
904}
905
906} // end namespace fs
907
908namespace path {
909
910bool home_directory(SmallVectorImpl<char> &result) {
911  char *RequestedDir = getenv("HOME");
912  if (!RequestedDir) {
913    struct passwd *pw = getpwuid(getuid());
914    if (pw && pw->pw_dir)
915      RequestedDir = pw->pw_dir;
916  }
917  if (!RequestedDir)
918    return false;
919
920  result.clear();
921  result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
922  return true;
923}
924
925static bool getDarwinConfDir(bool TempDir, SmallVectorImpl<char> &Result) {
926  #if defined(_CS_DARWIN_USER_TEMP_DIR) && defined(_CS_DARWIN_USER_CACHE_DIR)
927  // On Darwin, use DARWIN_USER_TEMP_DIR or DARWIN_USER_CACHE_DIR.
928  // macros defined in <unistd.h> on darwin >= 9
929  int ConfName = TempDir ? _CS_DARWIN_USER_TEMP_DIR
930                         : _CS_DARWIN_USER_CACHE_DIR;
931  size_t ConfLen = confstr(ConfName, nullptr, 0);
932  if (ConfLen > 0) {
933    do {
934      Result.resize(ConfLen);
935      ConfLen = confstr(ConfName, Result.data(), Result.size());
936    } while (ConfLen > 0 && ConfLen != Result.size());
937
938    if (ConfLen > 0) {
939      assert(Result.back() == 0);
940      Result.pop_back();
941      return true;
942    }
943
944    Result.clear();
945  }
946  #endif
947  return false;
948}
949
950static bool getUserCacheDir(SmallVectorImpl<char> &Result) {
951  // First try using XDG_CACHE_HOME env variable,
952  // as specified in XDG Base Directory Specification at
953  // http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
954  if (const char *XdgCacheDir = std::getenv("XDG_CACHE_HOME")) {
955    Result.clear();
956    Result.append(XdgCacheDir, XdgCacheDir + strlen(XdgCacheDir));
957    return true;
958  }
959
960  // Try Darwin configuration query
961  if (getDarwinConfDir(false, Result))
962    return true;
963
964  // Use "$HOME/.cache" if $HOME is available
965  if (home_directory(Result)) {
966    append(Result, ".cache");
967    return true;
968  }
969
970  return false;
971}
972
973static const char *getEnvTempDir() {
974  // Check whether the temporary directory is specified by an environment
975  // variable.
976  const char *EnvironmentVariables[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR"};
977  for (const char *Env : EnvironmentVariables) {
978    if (const char *Dir = std::getenv(Env))
979      return Dir;
980  }
981
982  return nullptr;
983}
984
985static const char *getDefaultTempDir(bool ErasedOnReboot) {
986#ifdef P_tmpdir
987  if ((bool)P_tmpdir)
988    return P_tmpdir;
989#endif
990
991  if (ErasedOnReboot)
992    return "/tmp";
993  return "/var/tmp";
994}
995
996void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) {
997  Result.clear();
998
999  if (ErasedOnReboot) {
1000    // There is no env variable for the cache directory.
1001    if (const char *RequestedDir = getEnvTempDir()) {
1002      Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
1003      return;
1004    }
1005  }
1006
1007  if (getDarwinConfDir(ErasedOnReboot, Result))
1008    return;
1009
1010  const char *RequestedDir = getDefaultTempDir(ErasedOnReboot);
1011  Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
1012}
1013
1014} // end namespace path
1015
1016} // end namespace sys
1017} // end namespace llvm
1018