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  SmallString<128> path_storage;
224  StringRef p = path.toNullTerminatedStringRef(path_storage);
225
226  if (::mkdir(p.begin(), S_IRWXU | S_IRWXG) == -1) {
227    if (errno != EEXIST || !IgnoreExisting)
228      return std::error_code(errno, std::generic_category());
229  }
230
231  return std::error_code();
232}
233
234// Note that we are using symbolic link because hard links are not supported by
235// all filesystems (SMB doesn't).
236std::error_code create_link(const Twine &to, const Twine &from) {
237  // Get arguments.
238  SmallString<128> from_storage;
239  SmallString<128> to_storage;
240  StringRef f = from.toNullTerminatedStringRef(from_storage);
241  StringRef t = to.toNullTerminatedStringRef(to_storage);
242
243  if (::symlink(t.begin(), f.begin()) == -1)
244    return std::error_code(errno, std::generic_category());
245
246  return std::error_code();
247}
248
249std::error_code remove(const Twine &path, bool IgnoreNonExisting) {
250  SmallString<128> path_storage;
251  StringRef p = path.toNullTerminatedStringRef(path_storage);
252
253  struct stat buf;
254  if (lstat(p.begin(), &buf) != 0) {
255    if (errno != ENOENT || !IgnoreNonExisting)
256      return std::error_code(errno, std::generic_category());
257    return std::error_code();
258  }
259
260  // Note: this check catches strange situations. In all cases, LLVM should
261  // only be involved in the creation and deletion of regular files.  This
262  // check ensures that what we're trying to erase is a regular file. It
263  // effectively prevents LLVM from erasing things like /dev/null, any block
264  // special file, or other things that aren't "regular" files.
265  if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode) && !S_ISLNK(buf.st_mode))
266    return make_error_code(errc::operation_not_permitted);
267
268  if (::remove(p.begin()) == -1) {
269    if (errno != ENOENT || !IgnoreNonExisting)
270      return std::error_code(errno, std::generic_category());
271  }
272
273  return std::error_code();
274}
275
276std::error_code rename(const Twine &from, const Twine &to) {
277  // Get arguments.
278  SmallString<128> from_storage;
279  SmallString<128> to_storage;
280  StringRef f = from.toNullTerminatedStringRef(from_storage);
281  StringRef t = to.toNullTerminatedStringRef(to_storage);
282
283  if (::rename(f.begin(), t.begin()) == -1)
284    return std::error_code(errno, std::generic_category());
285
286  return std::error_code();
287}
288
289std::error_code resize_file(int FD, uint64_t Size) {
290  if (::ftruncate(FD, Size) == -1)
291    return std::error_code(errno, std::generic_category());
292
293  return std::error_code();
294}
295
296static int convertAccessMode(AccessMode Mode) {
297  switch (Mode) {
298  case AccessMode::Exist:
299    return F_OK;
300  case AccessMode::Write:
301    return W_OK;
302  case AccessMode::Execute:
303    return R_OK | X_OK; // scripts also need R_OK.
304  }
305  llvm_unreachable("invalid enum");
306}
307
308std::error_code access(const Twine &Path, AccessMode Mode) {
309  SmallString<128> PathStorage;
310  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
311
312  if (::access(P.begin(), convertAccessMode(Mode)) == -1)
313    return std::error_code(errno, std::generic_category());
314
315  if (Mode == AccessMode::Execute) {
316    // Don't say that directories are executable.
317    struct stat buf;
318    if (0 != stat(P.begin(), &buf))
319      return errc::permission_denied;
320    if (!S_ISREG(buf.st_mode))
321      return errc::permission_denied;
322  }
323
324  return std::error_code();
325}
326
327bool equivalent(file_status A, file_status B) {
328  assert(status_known(A) && status_known(B));
329  return A.fs_st_dev == B.fs_st_dev &&
330         A.fs_st_ino == B.fs_st_ino;
331}
332
333std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
334  file_status fsA, fsB;
335  if (std::error_code ec = status(A, fsA))
336    return ec;
337  if (std::error_code ec = status(B, fsB))
338    return ec;
339  result = equivalent(fsA, fsB);
340  return std::error_code();
341}
342
343static std::error_code fillStatus(int StatRet, const struct stat &Status,
344                             file_status &Result) {
345  if (StatRet != 0) {
346    std::error_code ec(errno, std::generic_category());
347    if (ec == errc::no_such_file_or_directory)
348      Result = file_status(file_type::file_not_found);
349    else
350      Result = file_status(file_type::status_error);
351    return ec;
352  }
353
354  file_type Type = file_type::type_unknown;
355
356  if (S_ISDIR(Status.st_mode))
357    Type = file_type::directory_file;
358  else if (S_ISREG(Status.st_mode))
359    Type = file_type::regular_file;
360  else if (S_ISBLK(Status.st_mode))
361    Type = file_type::block_file;
362  else if (S_ISCHR(Status.st_mode))
363    Type = file_type::character_file;
364  else if (S_ISFIFO(Status.st_mode))
365    Type = file_type::fifo_file;
366  else if (S_ISSOCK(Status.st_mode))
367    Type = file_type::socket_file;
368
369  perms Perms = static_cast<perms>(Status.st_mode);
370  Result =
371      file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_mtime,
372                  Status.st_uid, Status.st_gid, Status.st_size);
373
374  return std::error_code();
375}
376
377std::error_code status(const Twine &Path, file_status &Result) {
378  SmallString<128> PathStorage;
379  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
380
381  struct stat Status;
382  int StatRet = ::stat(P.begin(), &Status);
383  return fillStatus(StatRet, Status, Result);
384}
385
386std::error_code status(int FD, file_status &Result) {
387  struct stat Status;
388  int StatRet = ::fstat(FD, &Status);
389  return fillStatus(StatRet, Status, Result);
390}
391
392std::error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
393#if defined(HAVE_FUTIMENS)
394  timespec Times[2];
395  Times[0].tv_sec = Time.toEpochTime();
396  Times[0].tv_nsec = 0;
397  Times[1] = Times[0];
398  if (::futimens(FD, Times))
399    return std::error_code(errno, std::generic_category());
400  return std::error_code();
401#elif defined(HAVE_FUTIMES)
402  timeval Times[2];
403  Times[0].tv_sec = Time.toEpochTime();
404  Times[0].tv_usec = 0;
405  Times[1] = Times[0];
406  if (::futimes(FD, Times))
407    return std::error_code(errno, std::generic_category());
408  return std::error_code();
409#else
410#warning Missing futimes() and futimens()
411  return make_error_code(errc::function_not_supported);
412#endif
413}
414
415std::error_code mapped_file_region::init(int FD, uint64_t Offset,
416                                         mapmode Mode) {
417  assert(Size != 0);
418
419  int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
420  int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
421  Mapping = ::mmap(nullptr, Size, prot, flags, FD, Offset);
422  if (Mapping == MAP_FAILED)
423    return std::error_code(errno, std::generic_category());
424  return std::error_code();
425}
426
427mapped_file_region::mapped_file_region(int fd, mapmode mode, uint64_t length,
428                                       uint64_t offset, std::error_code &ec)
429    : Size(length), Mapping() {
430  // Make sure that the requested size fits within SIZE_T.
431  if (length > std::numeric_limits<size_t>::max()) {
432    ec = make_error_code(errc::invalid_argument);
433    return;
434  }
435
436  ec = init(fd, offset, mode);
437  if (ec)
438    Mapping = nullptr;
439}
440
441mapped_file_region::~mapped_file_region() {
442  if (Mapping)
443    ::munmap(Mapping, Size);
444}
445
446uint64_t mapped_file_region::size() const {
447  assert(Mapping && "Mapping failed but used anyway!");
448  return Size;
449}
450
451char *mapped_file_region::data() const {
452  assert(Mapping && "Mapping failed but used anyway!");
453  return reinterpret_cast<char*>(Mapping);
454}
455
456const char *mapped_file_region::const_data() const {
457  assert(Mapping && "Mapping failed but used anyway!");
458  return reinterpret_cast<const char*>(Mapping);
459}
460
461int mapped_file_region::alignment() {
462  return Process::getPageSize();
463}
464
465std::error_code detail::directory_iterator_construct(detail::DirIterState &it,
466                                                StringRef path){
467  SmallString<128> path_null(path);
468  DIR *directory = ::opendir(path_null.c_str());
469  if (!directory)
470    return std::error_code(errno, std::generic_category());
471
472  it.IterationHandle = reinterpret_cast<intptr_t>(directory);
473  // Add something for replace_filename to replace.
474  path::append(path_null, ".");
475  it.CurrentEntry = directory_entry(path_null.str());
476  return directory_iterator_increment(it);
477}
478
479std::error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
480  if (it.IterationHandle)
481    ::closedir(reinterpret_cast<DIR *>(it.IterationHandle));
482  it.IterationHandle = 0;
483  it.CurrentEntry = directory_entry();
484  return std::error_code();
485}
486
487std::error_code detail::directory_iterator_increment(detail::DirIterState &it) {
488  errno = 0;
489  dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
490  if (cur_dir == nullptr && errno != 0) {
491    return std::error_code(errno, std::generic_category());
492  } else if (cur_dir != nullptr) {
493    StringRef name(cur_dir->d_name, NAMLEN(cur_dir));
494    if ((name.size() == 1 && name[0] == '.') ||
495        (name.size() == 2 && name[0] == '.' && name[1] == '.'))
496      return directory_iterator_increment(it);
497    it.CurrentEntry.replace_filename(name);
498  } else
499    return directory_iterator_destruct(it);
500
501  return std::error_code();
502}
503
504std::error_code openFileForRead(const Twine &Name, int &ResultFD) {
505  SmallString<128> Storage;
506  StringRef P = Name.toNullTerminatedStringRef(Storage);
507  while ((ResultFD = open(P.begin(), O_RDONLY)) < 0) {
508    if (errno != EINTR)
509      return std::error_code(errno, std::generic_category());
510  }
511  return std::error_code();
512}
513
514std::error_code openFileForWrite(const Twine &Name, int &ResultFD,
515                            sys::fs::OpenFlags Flags, unsigned Mode) {
516  // Verify that we don't have both "append" and "excl".
517  assert((!(Flags & sys::fs::F_Excl) || !(Flags & sys::fs::F_Append)) &&
518         "Cannot specify both 'excl' and 'append' file creation flags!");
519
520  int OpenFlags = O_CREAT;
521
522  if (Flags & F_RW)
523    OpenFlags |= O_RDWR;
524  else
525    OpenFlags |= O_WRONLY;
526
527  if (Flags & F_Append)
528    OpenFlags |= O_APPEND;
529  else
530    OpenFlags |= O_TRUNC;
531
532  if (Flags & F_Excl)
533    OpenFlags |= O_EXCL;
534
535  SmallString<128> Storage;
536  StringRef P = Name.toNullTerminatedStringRef(Storage);
537  while ((ResultFD = open(P.begin(), OpenFlags, Mode)) < 0) {
538    if (errno != EINTR)
539      return std::error_code(errno, std::generic_category());
540  }
541  return std::error_code();
542}
543
544} // end namespace fs
545
546namespace path {
547
548bool home_directory(SmallVectorImpl<char> &result) {
549  if (char *RequestedDir = getenv("HOME")) {
550    result.clear();
551    result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
552    return true;
553  }
554
555  return false;
556}
557
558static const char *getEnvTempDir() {
559  // Check whether the temporary directory is specified by an environment
560  // variable.
561  const char *EnvironmentVariables[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR"};
562  for (const char *Env : EnvironmentVariables) {
563    if (const char *Dir = std::getenv(Env))
564      return Dir;
565  }
566
567  return nullptr;
568}
569
570static const char *getDefaultTempDir(bool ErasedOnReboot) {
571#ifdef P_tmpdir
572  if ((bool)P_tmpdir)
573    return P_tmpdir;
574#endif
575
576  if (ErasedOnReboot)
577    return "/tmp";
578  return "/var/tmp";
579}
580
581void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) {
582  Result.clear();
583
584  if (ErasedOnReboot) {
585    // There is no env variable for the cache directory.
586    if (const char *RequestedDir = getEnvTempDir()) {
587      Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
588      return;
589    }
590  }
591
592#if defined(_CS_DARWIN_USER_TEMP_DIR) && defined(_CS_DARWIN_USER_CACHE_DIR)
593  // On Darwin, use DARWIN_USER_TEMP_DIR or DARWIN_USER_CACHE_DIR.
594  // macros defined in <unistd.h> on darwin >= 9
595  int ConfName = ErasedOnReboot? _CS_DARWIN_USER_TEMP_DIR
596                               : _CS_DARWIN_USER_CACHE_DIR;
597  size_t ConfLen = confstr(ConfName, nullptr, 0);
598  if (ConfLen > 0) {
599    do {
600      Result.resize(ConfLen);
601      ConfLen = confstr(ConfName, Result.data(), Result.size());
602    } while (ConfLen > 0 && ConfLen != Result.size());
603
604    if (ConfLen > 0) {
605      assert(Result.back() == 0);
606      Result.pop_back();
607      return;
608    }
609
610    Result.clear();
611  }
612#endif
613
614  const char *RequestedDir = getDefaultTempDir(ErasedOnReboot);
615  Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
616}
617
618} // end namespace path
619
620} // end namespace sys
621} // end namespace llvm
622