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 {
66  /// This class automatically closes the given file descriptor when it goes out
67  /// of scope. You can take back explicit ownership of the file descriptor by
68  /// calling take(). The destructor does not verify that close was successful.
69  /// Therefore, never allow this class to call close on a file descriptor that
70  /// has been read from or written to.
71  struct AutoFD {
72    int FileDescriptor;
73
74    AutoFD(int fd) : FileDescriptor(fd) {}
75    ~AutoFD() {
76      if (FileDescriptor >= 0)
77        ::close(FileDescriptor);
78    }
79
80    int take() {
81      int ret = FileDescriptor;
82      FileDescriptor = -1;
83      return ret;
84    }
85
86    operator int() const {return FileDescriptor;}
87  };
88}
89
90static std::error_code TempDir(SmallVectorImpl<char> &result) {
91  // FIXME: Don't use TMPDIR if program is SUID or SGID enabled.
92  const char *dir = nullptr;
93  (dir = std::getenv("TMPDIR")) || (dir = std::getenv("TMP")) ||
94      (dir = std::getenv("TEMP")) || (dir = std::getenv("TEMPDIR")) ||
95#ifdef P_tmpdir
96      (dir = P_tmpdir) ||
97#endif
98      (dir = "/tmp");
99
100  result.clear();
101  StringRef d(dir);
102  result.append(d.begin(), d.end());
103  return std::error_code();
104}
105
106namespace llvm {
107namespace sys  {
108namespace fs {
109#if defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
110    defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__) || \
111    defined(__linux__) || defined(__CYGWIN__) || defined(__DragonFly__)
112static int
113test_dir(char ret[PATH_MAX], const char *dir, const char *bin)
114{
115  struct stat sb;
116  char fullpath[PATH_MAX];
117
118  snprintf(fullpath, PATH_MAX, "%s/%s", dir, bin);
119  if (realpath(fullpath, ret) == NULL)
120    return (1);
121  if (stat(fullpath, &sb) != 0)
122    return (1);
123
124  return (0);
125}
126
127static char *
128getprogpath(char ret[PATH_MAX], const char *bin)
129{
130  char *pv, *s, *t;
131
132  /* First approach: absolute path. */
133  if (bin[0] == '/') {
134    if (test_dir(ret, "/", bin) == 0)
135      return (ret);
136    return (NULL);
137  }
138
139  /* Second approach: relative path. */
140  if (strchr(bin, '/') != NULL) {
141    char cwd[PATH_MAX];
142    if (getcwd(cwd, PATH_MAX) == NULL)
143      return (NULL);
144    if (test_dir(ret, cwd, bin) == 0)
145      return (ret);
146    return (NULL);
147  }
148
149  /* Third approach: $PATH */
150  if ((pv = getenv("PATH")) == NULL)
151    return (NULL);
152  s = pv = strdup(pv);
153  if (pv == NULL)
154    return (NULL);
155  while ((t = strsep(&s, ":")) != NULL) {
156    if (test_dir(ret, t, bin) == 0) {
157      free(pv);
158      return (ret);
159    }
160  }
161  free(pv);
162  return (NULL);
163}
164#endif // __FreeBSD__ || __NetBSD__ || __FreeBSD_kernel__
165
166/// GetMainExecutable - Return the path to the main executable, given the
167/// value of argv[0] from program startup.
168std::string getMainExecutable(const char *argv0, void *MainAddr) {
169#if defined(__APPLE__)
170  // On OS X the executable path is saved to the stack by dyld. Reading it
171  // from there is much faster than calling dladdr, especially for large
172  // binaries with symbols.
173  char exe_path[MAXPATHLEN];
174  uint32_t size = sizeof(exe_path);
175  if (_NSGetExecutablePath(exe_path, &size) == 0) {
176    char link_path[MAXPATHLEN];
177    if (realpath(exe_path, link_path))
178      return link_path;
179  }
180#elif defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
181      defined(__OpenBSD__) || defined(__minix) || defined(__DragonFly__) || \
182      defined(__FreeBSD_kernel__)
183  char exe_path[PATH_MAX];
184
185  if (getprogpath(exe_path, argv0) != NULL)
186    return exe_path;
187#elif defined(__linux__) || defined(__CYGWIN__)
188  char exe_path[MAXPATHLEN];
189  StringRef aPath("/proc/self/exe");
190  if (sys::fs::exists(aPath)) {
191      // /proc is not always mounted under Linux (chroot for example).
192      ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path));
193      if (len >= 0)
194          return StringRef(exe_path, len);
195  } else {
196      // Fall back to the classical detection.
197      if (getprogpath(exe_path, argv0) != NULL)
198          return exe_path;
199  }
200#elif defined(HAVE_DLFCN_H)
201  // Use dladdr to get executable path if available.
202  Dl_info DLInfo;
203  int err = dladdr(MainAddr, &DLInfo);
204  if (err == 0)
205    return "";
206
207  // If the filename is a symlink, we need to resolve and return the location of
208  // the actual executable.
209  char link_path[MAXPATHLEN];
210  if (realpath(DLInfo.dli_fname, link_path))
211    return link_path;
212#else
213#error GetMainExecutable is not implemented on this host yet.
214#endif
215  return "";
216}
217
218TimeValue file_status::getLastModificationTime() const {
219  TimeValue Ret;
220  Ret.fromEpochTime(fs_st_mtime);
221  return Ret;
222}
223
224UniqueID file_status::getUniqueID() const {
225  return UniqueID(fs_st_dev, fs_st_ino);
226}
227
228std::error_code current_path(SmallVectorImpl<char> &result) {
229  result.clear();
230
231  const char *pwd = ::getenv("PWD");
232  llvm::sys::fs::file_status PWDStatus, DotStatus;
233  if (pwd && llvm::sys::path::is_absolute(pwd) &&
234      !llvm::sys::fs::status(pwd, PWDStatus) &&
235      !llvm::sys::fs::status(".", DotStatus) &&
236      PWDStatus.getUniqueID() == DotStatus.getUniqueID()) {
237    result.append(pwd, pwd + strlen(pwd));
238    return std::error_code();
239  }
240
241#ifdef MAXPATHLEN
242  result.reserve(MAXPATHLEN);
243#else
244// For GNU Hurd
245  result.reserve(1024);
246#endif
247
248  while (true) {
249    if (::getcwd(result.data(), result.capacity()) == nullptr) {
250      // See if there was a real error.
251      if (errno != ENOMEM)
252        return std::error_code(errno, std::generic_category());
253      // Otherwise there just wasn't enough space.
254      result.reserve(result.capacity() * 2);
255    } else
256      break;
257  }
258
259  result.set_size(strlen(result.data()));
260  return std::error_code();
261}
262
263std::error_code create_directory(const Twine &path, bool IgnoreExisting) {
264  SmallString<128> path_storage;
265  StringRef p = path.toNullTerminatedStringRef(path_storage);
266
267  if (::mkdir(p.begin(), S_IRWXU | S_IRWXG) == -1) {
268    if (errno != EEXIST || !IgnoreExisting)
269      return std::error_code(errno, std::generic_category());
270  }
271
272  return std::error_code();
273}
274
275// Note that we are using symbolic link because hard links are not supported by
276// all filesystems (SMB doesn't).
277std::error_code create_link(const Twine &to, const Twine &from) {
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 (::symlink(t.begin(), f.begin()) == -1)
285    return std::error_code(errno, std::generic_category());
286
287  return std::error_code();
288}
289
290std::error_code remove(const Twine &path, bool IgnoreNonExisting) {
291  SmallString<128> path_storage;
292  StringRef p = path.toNullTerminatedStringRef(path_storage);
293
294  struct stat buf;
295  if (lstat(p.begin(), &buf) != 0) {
296    if (errno != ENOENT || !IgnoreNonExisting)
297      return std::error_code(errno, std::generic_category());
298    return std::error_code();
299  }
300
301  // Note: this check catches strange situations. In all cases, LLVM should
302  // only be involved in the creation and deletion of regular files.  This
303  // check ensures that what we're trying to erase is a regular file. It
304  // effectively prevents LLVM from erasing things like /dev/null, any block
305  // special file, or other things that aren't "regular" files.
306  if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode) && !S_ISLNK(buf.st_mode))
307    return make_error_code(errc::operation_not_permitted);
308
309  if (::remove(p.begin()) == -1) {
310    if (errno != ENOENT || !IgnoreNonExisting)
311      return std::error_code(errno, std::generic_category());
312  }
313
314  return std::error_code();
315}
316
317std::error_code rename(const Twine &from, const Twine &to) {
318  // Get arguments.
319  SmallString<128> from_storage;
320  SmallString<128> to_storage;
321  StringRef f = from.toNullTerminatedStringRef(from_storage);
322  StringRef t = to.toNullTerminatedStringRef(to_storage);
323
324  if (::rename(f.begin(), t.begin()) == -1)
325    return std::error_code(errno, std::generic_category());
326
327  return std::error_code();
328}
329
330std::error_code resize_file(const Twine &path, uint64_t size) {
331  SmallString<128> path_storage;
332  StringRef p = path.toNullTerminatedStringRef(path_storage);
333
334  if (::truncate(p.begin(), size) == -1)
335    return std::error_code(errno, std::generic_category());
336
337  return std::error_code();
338}
339
340std::error_code exists(const Twine &path, bool &result) {
341  SmallString<128> path_storage;
342  StringRef p = path.toNullTerminatedStringRef(path_storage);
343
344  if (::access(p.begin(), F_OK) == -1) {
345    if (errno != ENOENT)
346      return std::error_code(errno, std::generic_category());
347    result = false;
348  } else
349    result = true;
350
351  return std::error_code();
352}
353
354bool can_write(const Twine &Path) {
355  SmallString<128> PathStorage;
356  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
357  return 0 == access(P.begin(), W_OK);
358}
359
360bool can_execute(const Twine &Path) {
361  SmallString<128> PathStorage;
362  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
363
364  if (0 != access(P.begin(), R_OK | X_OK))
365    return false;
366  struct stat buf;
367  if (0 != stat(P.begin(), &buf))
368    return false;
369  if (!S_ISREG(buf.st_mode))
370    return false;
371  return true;
372}
373
374bool equivalent(file_status A, file_status B) {
375  assert(status_known(A) && status_known(B));
376  return A.fs_st_dev == B.fs_st_dev &&
377         A.fs_st_ino == B.fs_st_ino;
378}
379
380std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
381  file_status fsA, fsB;
382  if (std::error_code ec = status(A, fsA))
383    return ec;
384  if (std::error_code ec = status(B, fsB))
385    return ec;
386  result = equivalent(fsA, fsB);
387  return std::error_code();
388}
389
390static std::error_code fillStatus(int StatRet, const struct stat &Status,
391                             file_status &Result) {
392  if (StatRet != 0) {
393    std::error_code ec(errno, std::generic_category());
394    if (ec == errc::no_such_file_or_directory)
395      Result = file_status(file_type::file_not_found);
396    else
397      Result = file_status(file_type::status_error);
398    return ec;
399  }
400
401  file_type Type = file_type::type_unknown;
402
403  if (S_ISDIR(Status.st_mode))
404    Type = file_type::directory_file;
405  else if (S_ISREG(Status.st_mode))
406    Type = file_type::regular_file;
407  else if (S_ISBLK(Status.st_mode))
408    Type = file_type::block_file;
409  else if (S_ISCHR(Status.st_mode))
410    Type = file_type::character_file;
411  else if (S_ISFIFO(Status.st_mode))
412    Type = file_type::fifo_file;
413  else if (S_ISSOCK(Status.st_mode))
414    Type = file_type::socket_file;
415
416  perms Perms = static_cast<perms>(Status.st_mode);
417  Result =
418      file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_mtime,
419                  Status.st_uid, Status.st_gid, Status.st_size);
420
421  return std::error_code();
422}
423
424std::error_code status(const Twine &Path, file_status &Result) {
425  SmallString<128> PathStorage;
426  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
427
428  struct stat Status;
429  int StatRet = ::stat(P.begin(), &Status);
430  return fillStatus(StatRet, Status, Result);
431}
432
433std::error_code status(int FD, file_status &Result) {
434  struct stat Status;
435  int StatRet = ::fstat(FD, &Status);
436  return fillStatus(StatRet, Status, Result);
437}
438
439std::error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
440#if defined(HAVE_FUTIMENS)
441  timespec Times[2];
442  Times[0].tv_sec = Time.toEpochTime();
443  Times[0].tv_nsec = 0;
444  Times[1] = Times[0];
445  if (::futimens(FD, Times))
446    return std::error_code(errno, std::generic_category());
447  return std::error_code();
448#elif defined(HAVE_FUTIMES)
449  timeval Times[2];
450  Times[0].tv_sec = Time.toEpochTime();
451  Times[0].tv_usec = 0;
452  Times[1] = Times[0];
453  if (::futimes(FD, Times))
454    return std::error_code(errno, std::generic_category());
455  return std::error_code();
456#else
457#warning Missing futimes() and futimens()
458  return make_error_code(errc::function_not_supported);
459#endif
460}
461
462std::error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
463  AutoFD ScopedFD(FD);
464  if (!CloseFD)
465    ScopedFD.take();
466
467  // Figure out how large the file is.
468  struct stat FileInfo;
469  if (fstat(FD, &FileInfo) == -1)
470    return std::error_code(errno, std::generic_category());
471  uint64_t FileSize = FileInfo.st_size;
472
473  if (Size == 0)
474    Size = FileSize;
475  else if (FileSize < Size) {
476    // We need to grow the file.
477    if (ftruncate(FD, Size) == -1)
478      return std::error_code(errno, std::generic_category());
479  }
480
481  int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
482  int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
483#ifdef MAP_FILE
484  flags |= MAP_FILE;
485#endif
486  Mapping = ::mmap(nullptr, Size, prot, flags, FD, Offset);
487  if (Mapping == MAP_FAILED)
488    return std::error_code(errno, std::generic_category());
489  return std::error_code();
490}
491
492mapped_file_region::mapped_file_region(const Twine &path,
493                                       mapmode mode,
494                                       uint64_t length,
495                                       uint64_t offset,
496                                       std::error_code &ec)
497  : Mode(mode)
498  , Size(length)
499  , Mapping() {
500  // Make sure that the requested size fits within SIZE_T.
501  if (length > std::numeric_limits<size_t>::max()) {
502    ec = make_error_code(errc::invalid_argument);
503    return;
504  }
505
506  SmallString<128> path_storage;
507  StringRef name = path.toNullTerminatedStringRef(path_storage);
508  int oflags = (mode == readonly) ? O_RDONLY : O_RDWR;
509  int ofd = ::open(name.begin(), oflags);
510  if (ofd == -1) {
511    ec = std::error_code(errno, std::generic_category());
512    return;
513  }
514
515  ec = init(ofd, true, offset);
516  if (ec)
517    Mapping = nullptr;
518}
519
520mapped_file_region::mapped_file_region(int fd,
521                                       bool closefd,
522                                       mapmode mode,
523                                       uint64_t length,
524                                       uint64_t offset,
525                                       std::error_code &ec)
526  : Mode(mode)
527  , Size(length)
528  , Mapping() {
529  // Make sure that the requested size fits within SIZE_T.
530  if (length > std::numeric_limits<size_t>::max()) {
531    ec = make_error_code(errc::invalid_argument);
532    return;
533  }
534
535  ec = init(fd, closefd, offset);
536  if (ec)
537    Mapping = nullptr;
538}
539
540mapped_file_region::~mapped_file_region() {
541  if (Mapping)
542    ::munmap(Mapping, Size);
543}
544
545mapped_file_region::mapped_file_region(mapped_file_region &&other)
546  : Mode(other.Mode), Size(other.Size), Mapping(other.Mapping) {
547  other.Mapping = nullptr;
548}
549
550mapped_file_region::mapmode mapped_file_region::flags() const {
551  assert(Mapping && "Mapping failed but used anyway!");
552  return Mode;
553}
554
555uint64_t mapped_file_region::size() const {
556  assert(Mapping && "Mapping failed but used anyway!");
557  return Size;
558}
559
560char *mapped_file_region::data() const {
561  assert(Mapping && "Mapping failed but used anyway!");
562  assert(Mode != readonly && "Cannot get non-const data for readonly mapping!");
563  return reinterpret_cast<char*>(Mapping);
564}
565
566const char *mapped_file_region::const_data() const {
567  assert(Mapping && "Mapping failed but used anyway!");
568  return reinterpret_cast<const char*>(Mapping);
569}
570
571int mapped_file_region::alignment() {
572  return process::get_self()->page_size();
573}
574
575std::error_code detail::directory_iterator_construct(detail::DirIterState &it,
576                                                StringRef path){
577  SmallString<128> path_null(path);
578  DIR *directory = ::opendir(path_null.c_str());
579  if (!directory)
580    return std::error_code(errno, std::generic_category());
581
582  it.IterationHandle = reinterpret_cast<intptr_t>(directory);
583  // Add something for replace_filename to replace.
584  path::append(path_null, ".");
585  it.CurrentEntry = directory_entry(path_null.str());
586  return directory_iterator_increment(it);
587}
588
589std::error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
590  if (it.IterationHandle)
591    ::closedir(reinterpret_cast<DIR *>(it.IterationHandle));
592  it.IterationHandle = 0;
593  it.CurrentEntry = directory_entry();
594  return std::error_code();
595}
596
597std::error_code detail::directory_iterator_increment(detail::DirIterState &it) {
598  errno = 0;
599  dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
600  if (cur_dir == nullptr && errno != 0) {
601    return std::error_code(errno, std::generic_category());
602  } else if (cur_dir != nullptr) {
603    StringRef name(cur_dir->d_name, NAMLEN(cur_dir));
604    if ((name.size() == 1 && name[0] == '.') ||
605        (name.size() == 2 && name[0] == '.' && name[1] == '.'))
606      return directory_iterator_increment(it);
607    it.CurrentEntry.replace_filename(name);
608  } else
609    return directory_iterator_destruct(it);
610
611  return std::error_code();
612}
613
614std::error_code openFileForRead(const Twine &Name, int &ResultFD) {
615  SmallString<128> Storage;
616  StringRef P = Name.toNullTerminatedStringRef(Storage);
617  while ((ResultFD = open(P.begin(), O_RDONLY)) < 0) {
618    if (errno != EINTR)
619      return std::error_code(errno, std::generic_category());
620  }
621  return std::error_code();
622}
623
624std::error_code openFileForWrite(const Twine &Name, int &ResultFD,
625                            sys::fs::OpenFlags Flags, unsigned Mode) {
626  // Verify that we don't have both "append" and "excl".
627  assert((!(Flags & sys::fs::F_Excl) || !(Flags & sys::fs::F_Append)) &&
628         "Cannot specify both 'excl' and 'append' file creation flags!");
629
630  int OpenFlags = O_CREAT;
631
632  if (Flags & F_RW)
633    OpenFlags |= O_RDWR;
634  else
635    OpenFlags |= O_WRONLY;
636
637  if (Flags & F_Append)
638    OpenFlags |= O_APPEND;
639  else
640    OpenFlags |= O_TRUNC;
641
642  if (Flags & F_Excl)
643    OpenFlags |= O_EXCL;
644
645  SmallString<128> Storage;
646  StringRef P = Name.toNullTerminatedStringRef(Storage);
647  while ((ResultFD = open(P.begin(), OpenFlags, Mode)) < 0) {
648    if (errno != EINTR)
649      return std::error_code(errno, std::generic_category());
650  }
651  return std::error_code();
652}
653
654} // end namespace fs
655
656namespace path {
657
658bool home_directory(SmallVectorImpl<char> &result) {
659  if (char *RequestedDir = getenv("HOME")) {
660    result.clear();
661    result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
662    return true;
663  }
664
665  return false;
666}
667
668} // end namespace path
669
670} // end namespace sys
671} // end namespace llvm
672