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_SYS_MMAN_H
29#include <sys/mman.h>
30#endif
31#if HAVE_DIRENT_H
32# include <dirent.h>
33# define NAMLEN(dirent) strlen((dirent)->d_name)
34#else
35# define dirent direct
36# define NAMLEN(dirent) (dirent)->d_namlen
37# if HAVE_SYS_NDIR_H
38#  include <sys/ndir.h>
39# endif
40# if HAVE_SYS_DIR_H
41#  include <sys/dir.h>
42# endif
43# if HAVE_NDIR_H
44#  include <ndir.h>
45# endif
46#endif
47
48#ifdef __APPLE__
49#include <mach-o/dyld.h>
50#endif
51
52// Both stdio.h and cstdio are included via different pathes and
53// stdcxx's cstdio doesn't include stdio.h, so it doesn't #undef the macros
54// either.
55#undef ferror
56#undef feof
57
58// For GNU Hurd
59#if defined(__GNU__) && !defined(PATH_MAX)
60# define PATH_MAX 4096
61#endif
62
63using namespace llvm;
64
65namespace llvm {
66namespace sys  {
67namespace fs {
68#if defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
69    defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__) || \
70    defined(__linux__) || defined(__CYGWIN__) || defined(__DragonFly__)
71static int
72test_dir(char ret[PATH_MAX], const char *dir, const char *bin)
73{
74  struct stat sb;
75  char fullpath[PATH_MAX];
76
77  snprintf(fullpath, PATH_MAX, "%s/%s", dir, bin);
78  if (realpath(fullpath, ret) == NULL)
79    return (1);
80  if (stat(fullpath, &sb) != 0)
81    return (1);
82
83  return (0);
84}
85
86static char *
87getprogpath(char ret[PATH_MAX], const char *bin)
88{
89  char *pv, *s, *t;
90
91  /* First approach: absolute path. */
92  if (bin[0] == '/') {
93    if (test_dir(ret, "/", bin) == 0)
94      return (ret);
95    return (NULL);
96  }
97
98  /* Second approach: relative path. */
99  if (strchr(bin, '/') != NULL) {
100    char cwd[PATH_MAX];
101    if (getcwd(cwd, PATH_MAX) == NULL)
102      return (NULL);
103    if (test_dir(ret, cwd, bin) == 0)
104      return (ret);
105    return (NULL);
106  }
107
108  /* Third approach: $PATH */
109  if ((pv = getenv("PATH")) == NULL)
110    return (NULL);
111  s = pv = strdup(pv);
112  if (pv == NULL)
113    return (NULL);
114  while ((t = strsep(&s, ":")) != NULL) {
115    if (test_dir(ret, t, bin) == 0) {
116      free(pv);
117      return (ret);
118    }
119  }
120  free(pv);
121  return (NULL);
122}
123#endif // __FreeBSD__ || __NetBSD__ || __FreeBSD_kernel__
124
125/// GetMainExecutable - Return the path to the main executable, given the
126/// value of argv[0] from program startup.
127std::string getMainExecutable(const char *argv0, void *MainAddr) {
128#if defined(__APPLE__)
129  // On OS X the executable path is saved to the stack by dyld. Reading it
130  // from there is much faster than calling dladdr, especially for large
131  // binaries with symbols.
132  char exe_path[MAXPATHLEN];
133  uint32_t size = sizeof(exe_path);
134  if (_NSGetExecutablePath(exe_path, &size) == 0) {
135    char link_path[MAXPATHLEN];
136    if (realpath(exe_path, link_path))
137      return link_path;
138  }
139#elif defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
140      defined(__OpenBSD__) || defined(__minix) || defined(__DragonFly__) || \
141      defined(__FreeBSD_kernel__)
142  char exe_path[PATH_MAX];
143
144  if (getprogpath(exe_path, argv0) != NULL)
145    return exe_path;
146#elif defined(__linux__) || defined(__CYGWIN__)
147  char exe_path[MAXPATHLEN];
148  StringRef aPath("/proc/self/exe");
149  if (sys::fs::exists(aPath)) {
150      // /proc is not always mounted under Linux (chroot for example).
151      ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path));
152      if (len >= 0)
153          return std::string(exe_path, len);
154  } else {
155      // Fall back to the classical detection.
156      if (getprogpath(exe_path, argv0) != NULL)
157          return exe_path;
158  }
159#elif defined(HAVE_DLFCN_H)
160  // Use dladdr to get executable path if available.
161  Dl_info DLInfo;
162  int err = dladdr(MainAddr, &DLInfo);
163  if (err == 0)
164    return "";
165
166  // If the filename is a symlink, we need to resolve and return the location of
167  // the actual executable.
168  char link_path[MAXPATHLEN];
169  if (realpath(DLInfo.dli_fname, link_path))
170    return link_path;
171#else
172#error GetMainExecutable is not implemented on this host yet.
173#endif
174  return "";
175}
176
177TimeValue file_status::getLastModificationTime() const {
178  TimeValue Ret;
179  Ret.fromEpochTime(fs_st_mtime);
180  return Ret;
181}
182
183UniqueID file_status::getUniqueID() const {
184  return UniqueID(fs_st_dev, fs_st_ino);
185}
186
187std::error_code current_path(SmallVectorImpl<char> &result) {
188  result.clear();
189
190  const char *pwd = ::getenv("PWD");
191  llvm::sys::fs::file_status PWDStatus, DotStatus;
192  if (pwd && llvm::sys::path::is_absolute(pwd) &&
193      !llvm::sys::fs::status(pwd, PWDStatus) &&
194      !llvm::sys::fs::status(".", DotStatus) &&
195      PWDStatus.getUniqueID() == DotStatus.getUniqueID()) {
196    result.append(pwd, pwd + strlen(pwd));
197    return std::error_code();
198  }
199
200#ifdef MAXPATHLEN
201  result.reserve(MAXPATHLEN);
202#else
203// For GNU Hurd
204  result.reserve(1024);
205#endif
206
207  while (true) {
208    if (::getcwd(result.data(), result.capacity()) == nullptr) {
209      // See if there was a real error.
210      if (errno != ENOMEM)
211        return std::error_code(errno, std::generic_category());
212      // Otherwise there just wasn't enough space.
213      result.reserve(result.capacity() * 2);
214    } else
215      break;
216  }
217
218  result.set_size(strlen(result.data()));
219  return std::error_code();
220}
221
222std::error_code create_directory(const Twine &path, bool IgnoreExisting,
223                                 perms Perms) {
224  SmallString<128> path_storage;
225  StringRef p = path.toNullTerminatedStringRef(path_storage);
226
227  if (::mkdir(p.begin(), Perms) == -1) {
228    if (errno != EEXIST || !IgnoreExisting)
229      return std::error_code(errno, std::generic_category());
230  }
231
232  return std::error_code();
233}
234
235// Note that we are using symbolic link because hard links are not supported by
236// all filesystems (SMB doesn't).
237std::error_code create_link(const Twine &to, const Twine &from) {
238  // Get arguments.
239  SmallString<128> from_storage;
240  SmallString<128> to_storage;
241  StringRef f = from.toNullTerminatedStringRef(from_storage);
242  StringRef t = to.toNullTerminatedStringRef(to_storage);
243
244  if (::symlink(t.begin(), f.begin()) == -1)
245    return std::error_code(errno, std::generic_category());
246
247  return std::error_code();
248}
249
250std::error_code remove(const Twine &path, bool IgnoreNonExisting) {
251  SmallString<128> path_storage;
252  StringRef p = path.toNullTerminatedStringRef(path_storage);
253
254  struct stat buf;
255  if (lstat(p.begin(), &buf) != 0) {
256    if (errno != ENOENT || !IgnoreNonExisting)
257      return std::error_code(errno, std::generic_category());
258    return std::error_code();
259  }
260
261  // Note: this check catches strange situations. In all cases, LLVM should
262  // only be involved in the creation and deletion of regular files.  This
263  // check ensures that what we're trying to erase is a regular file. It
264  // effectively prevents LLVM from erasing things like /dev/null, any block
265  // special file, or other things that aren't "regular" files.
266  if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode) && !S_ISLNK(buf.st_mode))
267    return make_error_code(errc::operation_not_permitted);
268
269  if (::remove(p.begin()) == -1) {
270    if (errno != ENOENT || !IgnoreNonExisting)
271      return std::error_code(errno, std::generic_category());
272  }
273
274  return std::error_code();
275}
276
277std::error_code rename(const Twine &from, const Twine &to) {
278  // Get arguments.
279  SmallString<128> from_storage;
280  SmallString<128> to_storage;
281  StringRef f = from.toNullTerminatedStringRef(from_storage);
282  StringRef t = to.toNullTerminatedStringRef(to_storage);
283
284  if (::rename(f.begin(), t.begin()) == -1)
285    return std::error_code(errno, std::generic_category());
286
287  return std::error_code();
288}
289
290std::error_code resize_file(int FD, uint64_t Size) {
291  if (::ftruncate(FD, Size) == -1)
292    return std::error_code(errno, std::generic_category());
293
294  return std::error_code();
295}
296
297static int convertAccessMode(AccessMode Mode) {
298  switch (Mode) {
299  case AccessMode::Exist:
300    return F_OK;
301  case AccessMode::Write:
302    return W_OK;
303  case AccessMode::Execute:
304    return R_OK | X_OK; // scripts also need R_OK.
305  }
306  llvm_unreachable("invalid enum");
307}
308
309std::error_code access(const Twine &Path, AccessMode Mode) {
310  SmallString<128> PathStorage;
311  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
312
313  if (::access(P.begin(), convertAccessMode(Mode)) == -1)
314    return std::error_code(errno, std::generic_category());
315
316  if (Mode == AccessMode::Execute) {
317    // Don't say that directories are executable.
318    struct stat buf;
319    if (0 != stat(P.begin(), &buf))
320      return errc::permission_denied;
321    if (!S_ISREG(buf.st_mode))
322      return errc::permission_denied;
323  }
324
325  return std::error_code();
326}
327
328bool equivalent(file_status A, file_status B) {
329  assert(status_known(A) && status_known(B));
330  return A.fs_st_dev == B.fs_st_dev &&
331         A.fs_st_ino == B.fs_st_ino;
332}
333
334std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
335  file_status fsA, fsB;
336  if (std::error_code ec = status(A, fsA))
337    return ec;
338  if (std::error_code ec = status(B, fsB))
339    return ec;
340  result = equivalent(fsA, fsB);
341  return std::error_code();
342}
343
344static std::error_code fillStatus(int StatRet, const struct stat &Status,
345                             file_status &Result) {
346  if (StatRet != 0) {
347    std::error_code ec(errno, std::generic_category());
348    if (ec == errc::no_such_file_or_directory)
349      Result = file_status(file_type::file_not_found);
350    else
351      Result = file_status(file_type::status_error);
352    return ec;
353  }
354
355  file_type Type = file_type::type_unknown;
356
357  if (S_ISDIR(Status.st_mode))
358    Type = file_type::directory_file;
359  else if (S_ISREG(Status.st_mode))
360    Type = file_type::regular_file;
361  else if (S_ISBLK(Status.st_mode))
362    Type = file_type::block_file;
363  else if (S_ISCHR(Status.st_mode))
364    Type = file_type::character_file;
365  else if (S_ISFIFO(Status.st_mode))
366    Type = file_type::fifo_file;
367  else if (S_ISSOCK(Status.st_mode))
368    Type = file_type::socket_file;
369
370  perms Perms = static_cast<perms>(Status.st_mode);
371  Result =
372      file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_mtime,
373                  Status.st_uid, Status.st_gid, Status.st_size);
374
375  return std::error_code();
376}
377
378std::error_code status(const Twine &Path, file_status &Result) {
379  SmallString<128> PathStorage;
380  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
381
382  struct stat Status;
383  int StatRet = ::stat(P.begin(), &Status);
384  return fillStatus(StatRet, Status, Result);
385}
386
387std::error_code status(int FD, file_status &Result) {
388  struct stat Status;
389  int StatRet = ::fstat(FD, &Status);
390  return fillStatus(StatRet, Status, Result);
391}
392
393std::error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
394#if defined(HAVE_FUTIMENS)
395  timespec Times[2];
396  Times[0].tv_sec = Time.toEpochTime();
397  Times[0].tv_nsec = 0;
398  Times[1] = Times[0];
399  if (::futimens(FD, Times))
400    return std::error_code(errno, std::generic_category());
401  return std::error_code();
402#elif defined(HAVE_FUTIMES)
403  timeval Times[2];
404  Times[0].tv_sec = Time.toEpochTime();
405  Times[0].tv_usec = 0;
406  Times[1] = Times[0];
407  if (::futimes(FD, Times))
408    return std::error_code(errno, std::generic_category());
409  return std::error_code();
410#else
411#warning Missing futimes() and futimens()
412  return make_error_code(errc::function_not_supported);
413#endif
414}
415
416std::error_code mapped_file_region::init(int FD, uint64_t Offset,
417                                         mapmode Mode) {
418  assert(Size != 0);
419
420  int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
421  int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
422  Mapping = ::mmap(nullptr, Size, prot, flags, FD, Offset);
423  if (Mapping == MAP_FAILED)
424    return std::error_code(errno, std::generic_category());
425  return std::error_code();
426}
427
428mapped_file_region::mapped_file_region(int fd, mapmode mode, uint64_t length,
429                                       uint64_t offset, std::error_code &ec)
430    : Size(length), Mapping() {
431  // Make sure that the requested size fits within SIZE_T.
432  if (length > std::numeric_limits<size_t>::max()) {
433    ec = make_error_code(errc::invalid_argument);
434    return;
435  }
436
437  ec = init(fd, offset, mode);
438  if (ec)
439    Mapping = nullptr;
440}
441
442mapped_file_region::~mapped_file_region() {
443  if (Mapping)
444    ::munmap(Mapping, Size);
445}
446
447uint64_t mapped_file_region::size() const {
448  assert(Mapping && "Mapping failed but used anyway!");
449  return Size;
450}
451
452char *mapped_file_region::data() const {
453  assert(Mapping && "Mapping failed but used anyway!");
454  return reinterpret_cast<char*>(Mapping);
455}
456
457const char *mapped_file_region::const_data() const {
458  assert(Mapping && "Mapping failed but used anyway!");
459  return reinterpret_cast<const char*>(Mapping);
460}
461
462int mapped_file_region::alignment() {
463  return Process::getPageSize();
464}
465
466std::error_code detail::directory_iterator_construct(detail::DirIterState &it,
467                                                StringRef path){
468  SmallString<128> path_null(path);
469  DIR *directory = ::opendir(path_null.c_str());
470  if (!directory)
471    return std::error_code(errno, std::generic_category());
472
473  it.IterationHandle = reinterpret_cast<intptr_t>(directory);
474  // Add something for replace_filename to replace.
475  path::append(path_null, ".");
476  it.CurrentEntry = directory_entry(path_null.str());
477  return directory_iterator_increment(it);
478}
479
480std::error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
481  if (it.IterationHandle)
482    ::closedir(reinterpret_cast<DIR *>(it.IterationHandle));
483  it.IterationHandle = 0;
484  it.CurrentEntry = directory_entry();
485  return std::error_code();
486}
487
488std::error_code detail::directory_iterator_increment(detail::DirIterState &it) {
489  errno = 0;
490  dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
491  if (cur_dir == nullptr && errno != 0) {
492    return std::error_code(errno, std::generic_category());
493  } else if (cur_dir != nullptr) {
494    StringRef name(cur_dir->d_name, NAMLEN(cur_dir));
495    if ((name.size() == 1 && name[0] == '.') ||
496        (name.size() == 2 && name[0] == '.' && name[1] == '.'))
497      return directory_iterator_increment(it);
498    it.CurrentEntry.replace_filename(name);
499  } else
500    return directory_iterator_destruct(it);
501
502  return std::error_code();
503}
504
505std::error_code openFileForRead(const Twine &Name, int &ResultFD) {
506  SmallString<128> Storage;
507  StringRef P = Name.toNullTerminatedStringRef(Storage);
508  while ((ResultFD = open(P.begin(), O_RDONLY)) < 0) {
509    if (errno != EINTR)
510      return std::error_code(errno, std::generic_category());
511  }
512  return std::error_code();
513}
514
515std::error_code openFileForWrite(const Twine &Name, int &ResultFD,
516                            sys::fs::OpenFlags Flags, unsigned Mode) {
517  // Verify that we don't have both "append" and "excl".
518  assert((!(Flags & sys::fs::F_Excl) || !(Flags & sys::fs::F_Append)) &&
519         "Cannot specify both 'excl' and 'append' file creation flags!");
520
521  int OpenFlags = O_CREAT;
522
523  if (Flags & F_RW)
524    OpenFlags |= O_RDWR;
525  else
526    OpenFlags |= O_WRONLY;
527
528  if (Flags & F_Append)
529    OpenFlags |= O_APPEND;
530  else
531    OpenFlags |= O_TRUNC;
532
533  if (Flags & F_Excl)
534    OpenFlags |= O_EXCL;
535
536  SmallString<128> Storage;
537  StringRef P = Name.toNullTerminatedStringRef(Storage);
538  while ((ResultFD = open(P.begin(), OpenFlags, Mode)) < 0) {
539    if (errno != EINTR)
540      return std::error_code(errno, std::generic_category());
541  }
542  return std::error_code();
543}
544
545} // end namespace fs
546
547namespace path {
548
549bool home_directory(SmallVectorImpl<char> &result) {
550  if (char *RequestedDir = getenv("HOME")) {
551    result.clear();
552    result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
553    return true;
554  }
555
556  return false;
557}
558
559static const char *getEnvTempDir() {
560  // Check whether the temporary directory is specified by an environment
561  // variable.
562  const char *EnvironmentVariables[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR"};
563  for (const char *Env : EnvironmentVariables) {
564    if (const char *Dir = std::getenv(Env))
565      return Dir;
566  }
567
568  return nullptr;
569}
570
571static const char *getDefaultTempDir(bool ErasedOnReboot) {
572#ifdef P_tmpdir
573  if ((bool)P_tmpdir)
574    return P_tmpdir;
575#endif
576
577  if (ErasedOnReboot)
578    return "/tmp";
579  return "/var/tmp";
580}
581
582void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) {
583  Result.clear();
584
585  if (ErasedOnReboot) {
586    // There is no env variable for the cache directory.
587    if (const char *RequestedDir = getEnvTempDir()) {
588      Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
589      return;
590    }
591  }
592
593#if defined(_CS_DARWIN_USER_TEMP_DIR) && defined(_CS_DARWIN_USER_CACHE_DIR)
594  // On Darwin, use DARWIN_USER_TEMP_DIR or DARWIN_USER_CACHE_DIR.
595  // macros defined in <unistd.h> on darwin >= 9
596  int ConfName = ErasedOnReboot? _CS_DARWIN_USER_TEMP_DIR
597                               : _CS_DARWIN_USER_CACHE_DIR;
598  size_t ConfLen = confstr(ConfName, nullptr, 0);
599  if (ConfLen > 0) {
600    do {
601      Result.resize(ConfLen);
602      ConfLen = confstr(ConfName, Result.data(), Result.size());
603    } while (ConfLen > 0 && ConfLen != Result.size());
604
605    if (ConfLen > 0) {
606      assert(Result.back() == 0);
607      Result.pop_back();
608      return;
609    }
610
611    Result.clear();
612  }
613#endif
614
615  const char *RequestedDir = getDefaultTempDir(ErasedOnReboot);
616  Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
617}
618
619} // end namespace path
620
621} // end namespace sys
622} // end namespace llvm
623