1//===- llvm/Support/Unix/PathV2.cpp - 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 PathV2 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#if HAVE_SYS_STAT_H
21#include <sys/stat.h>
22#endif
23#if HAVE_FCNTL_H
24#include <fcntl.h>
25#endif
26#if HAVE_DIRENT_H
27# include <dirent.h>
28# define NAMLEN(dirent) strlen((dirent)->d_name)
29#else
30# define dirent direct
31# define NAMLEN(dirent) (dirent)->d_namlen
32# if HAVE_SYS_NDIR_H
33#  include <sys/ndir.h>
34# endif
35# if HAVE_SYS_DIR_H
36#  include <sys/dir.h>
37# endif
38# if HAVE_NDIR_H
39#  include <ndir.h>
40# endif
41#endif
42#if HAVE_STDIO_H
43#include <stdio.h>
44#endif
45#if HAVE_LIMITS_H
46#include <limits.h>
47#endif
48
49using namespace llvm;
50
51namespace {
52  /// This class automatically closes the given file descriptor when it goes out
53  /// of scope. You can take back explicit ownership of the file descriptor by
54  /// calling take(). The destructor does not verify that close was successful.
55  /// Therefore, never allow this class to call close on a file descriptor that
56  /// has been read from or written to.
57  struct AutoFD {
58    int FileDescriptor;
59
60    AutoFD(int fd) : FileDescriptor(fd) {}
61    ~AutoFD() {
62      if (FileDescriptor >= 0)
63        ::close(FileDescriptor);
64    }
65
66    int take() {
67      int ret = FileDescriptor;
68      FileDescriptor = -1;
69      return ret;
70    }
71
72    operator int() const {return FileDescriptor;}
73  };
74
75  error_code TempDir(SmallVectorImpl<char> &result) {
76    // FIXME: Don't use TMPDIR if program is SUID or SGID enabled.
77    const char *dir = 0;
78    (dir = std::getenv("TMPDIR" )) ||
79    (dir = std::getenv("TMP"    )) ||
80    (dir = std::getenv("TEMP"   )) ||
81    (dir = std::getenv("TEMPDIR")) ||
82#ifdef P_tmpdir
83    (dir = P_tmpdir) ||
84#endif
85    (dir = "/tmp");
86
87    result.clear();
88    StringRef d(dir);
89    result.append(d.begin(), d.end());
90    return success;
91  }
92}
93
94namespace llvm {
95namespace sys  {
96namespace fs {
97
98error_code current_path(SmallVectorImpl<char> &result) {
99  result.reserve(MAXPATHLEN);
100
101  while (true) {
102    if (::getcwd(result.data(), result.capacity()) == 0) {
103      // See if there was a real error.
104      if (errno != errc::not_enough_memory)
105        return error_code(errno, system_category());
106      // Otherwise there just wasn't enough space.
107      result.reserve(result.capacity() * 2);
108    } else
109      break;
110  }
111
112  result.set_size(strlen(result.data()));
113  return success;
114}
115
116error_code copy_file(const Twine &from, const Twine &to, copy_option copt) {
117 // Get arguments.
118  SmallString<128> from_storage;
119  SmallString<128> to_storage;
120  StringRef f = from.toNullTerminatedStringRef(from_storage);
121  StringRef t = to.toNullTerminatedStringRef(to_storage);
122
123  const size_t buf_sz = 32768;
124  char buffer[buf_sz];
125  int from_file = -1, to_file = -1;
126
127  // Open from.
128  if ((from_file = ::open(f.begin(), O_RDONLY)) < 0)
129    return error_code(errno, system_category());
130  AutoFD from_fd(from_file);
131
132  // Stat from.
133  struct stat from_stat;
134  if (::stat(f.begin(), &from_stat) != 0)
135    return error_code(errno, system_category());
136
137  // Setup to flags.
138  int to_flags = O_CREAT | O_WRONLY;
139  if (copt == copy_option::fail_if_exists)
140    to_flags |= O_EXCL;
141
142  // Open to.
143  if ((to_file = ::open(t.begin(), to_flags, from_stat.st_mode)) < 0)
144    return error_code(errno, system_category());
145  AutoFD to_fd(to_file);
146
147  // Copy!
148  ssize_t sz, sz_read = 1, sz_write;
149  while (sz_read > 0 &&
150         (sz_read = ::read(from_fd, buffer, buf_sz)) > 0) {
151    // Allow for partial writes - see Advanced Unix Programming (2nd Ed.),
152    // Marc Rochkind, Addison-Wesley, 2004, page 94
153    sz_write = 0;
154    do {
155      if ((sz = ::write(to_fd, buffer + sz_write, sz_read - sz_write)) < 0) {
156        sz_read = sz;  // cause read loop termination.
157        break;         // error.
158      }
159      sz_write += sz;
160    } while (sz_write < sz_read);
161  }
162
163  // After all the file operations above the return value of close actually
164  // matters.
165  if (::close(from_fd.take()) < 0) sz_read = -1;
166  if (::close(to_fd.take()) < 0) sz_read = -1;
167
168  // Check for errors.
169  if (sz_read < 0)
170    return error_code(errno, system_category());
171
172  return success;
173}
174
175error_code create_directory(const Twine &path, bool &existed) {
176  SmallString<128> path_storage;
177  StringRef p = path.toNullTerminatedStringRef(path_storage);
178
179  if (::mkdir(p.begin(), S_IRWXU | S_IRWXG) == -1) {
180    if (errno != errc::file_exists)
181      return error_code(errno, system_category());
182    existed = true;
183  } else
184    existed = false;
185
186  return success;
187}
188
189error_code create_hard_link(const Twine &to, const Twine &from) {
190  // Get arguments.
191  SmallString<128> from_storage;
192  SmallString<128> to_storage;
193  StringRef f = from.toNullTerminatedStringRef(from_storage);
194  StringRef t = to.toNullTerminatedStringRef(to_storage);
195
196  if (::link(t.begin(), f.begin()) == -1)
197    return error_code(errno, system_category());
198
199  return success;
200}
201
202error_code create_symlink(const Twine &to, const Twine &from) {
203  // Get arguments.
204  SmallString<128> from_storage;
205  SmallString<128> to_storage;
206  StringRef f = from.toNullTerminatedStringRef(from_storage);
207  StringRef t = to.toNullTerminatedStringRef(to_storage);
208
209  if (::symlink(t.begin(), f.begin()) == -1)
210    return error_code(errno, system_category());
211
212  return success;
213}
214
215error_code remove(const Twine &path, bool &existed) {
216  SmallString<128> path_storage;
217  StringRef p = path.toNullTerminatedStringRef(path_storage);
218
219  if (::remove(p.begin()) == -1) {
220    if (errno != errc::no_such_file_or_directory)
221      return error_code(errno, system_category());
222    existed = false;
223  } else
224    existed = true;
225
226  return success;
227}
228
229error_code rename(const Twine &from, const Twine &to) {
230  // Get arguments.
231  SmallString<128> from_storage;
232  SmallString<128> to_storage;
233  StringRef f = from.toNullTerminatedStringRef(from_storage);
234  StringRef t = to.toNullTerminatedStringRef(to_storage);
235
236  if (::rename(f.begin(), t.begin()) == -1) {
237    // If it's a cross device link, copy then delete, otherwise return the error
238    if (errno == EXDEV) {
239      if (error_code ec = copy_file(from, to, copy_option::overwrite_if_exists))
240        return ec;
241      bool Existed;
242      if (error_code ec = remove(from, Existed))
243        return ec;
244    } else
245      return error_code(errno, system_category());
246  }
247
248  return success;
249}
250
251error_code resize_file(const Twine &path, uint64_t size) {
252  SmallString<128> path_storage;
253  StringRef p = path.toNullTerminatedStringRef(path_storage);
254
255  if (::truncate(p.begin(), size) == -1)
256    return error_code(errno, system_category());
257
258  return success;
259}
260
261error_code exists(const Twine &path, bool &result) {
262  SmallString<128> path_storage;
263  StringRef p = path.toNullTerminatedStringRef(path_storage);
264
265  struct stat status;
266  if (::stat(p.begin(), &status) == -1) {
267    if (errno != errc::no_such_file_or_directory)
268      return error_code(errno, system_category());
269    result = false;
270  } else
271    result = true;
272
273  return success;
274}
275
276error_code equivalent(const Twine &A, const Twine &B, bool &result) {
277  // Get arguments.
278  SmallString<128> a_storage;
279  SmallString<128> b_storage;
280  StringRef a = A.toNullTerminatedStringRef(a_storage);
281  StringRef b = B.toNullTerminatedStringRef(b_storage);
282
283  struct stat stat_a, stat_b;
284  int error_b = ::stat(b.begin(), &stat_b);
285  int error_a = ::stat(a.begin(), &stat_a);
286
287  // If both are invalid, it's an error. If only one is, the result is false.
288  if (error_a != 0 || error_b != 0) {
289    if (error_a == error_b)
290      return error_code(errno, system_category());
291    result = false;
292  } else {
293    result =
294      stat_a.st_dev == stat_b.st_dev &&
295      stat_a.st_ino == stat_b.st_ino;
296  }
297
298  return success;
299}
300
301error_code file_size(const Twine &path, uint64_t &result) {
302  SmallString<128> path_storage;
303  StringRef p = path.toNullTerminatedStringRef(path_storage);
304
305  struct stat status;
306  if (::stat(p.begin(), &status) == -1)
307    return error_code(errno, system_category());
308  if (!S_ISREG(status.st_mode))
309    return make_error_code(errc::operation_not_permitted);
310
311  result = status.st_size;
312  return success;
313}
314
315error_code status(const Twine &path, file_status &result) {
316  SmallString<128> path_storage;
317  StringRef p = path.toNullTerminatedStringRef(path_storage);
318
319  struct stat status;
320  if (::stat(p.begin(), &status) != 0) {
321    error_code ec(errno, system_category());
322    if (ec == errc::no_such_file_or_directory)
323      result = file_status(file_type::file_not_found);
324    else
325      result = file_status(file_type::status_error);
326    return ec;
327  }
328
329  if (S_ISDIR(status.st_mode))
330    result = file_status(file_type::directory_file);
331  else if (S_ISREG(status.st_mode))
332    result = file_status(file_type::regular_file);
333  else if (S_ISBLK(status.st_mode))
334    result = file_status(file_type::block_file);
335  else if (S_ISCHR(status.st_mode))
336    result = file_status(file_type::character_file);
337  else if (S_ISFIFO(status.st_mode))
338    result = file_status(file_type::fifo_file);
339  else if (S_ISSOCK(status.st_mode))
340    result = file_status(file_type::socket_file);
341  else
342    result = file_status(file_type::type_unknown);
343
344  return success;
345}
346
347error_code unique_file(const Twine &model, int &result_fd,
348                             SmallVectorImpl<char> &result_path,
349                             bool makeAbsolute) {
350  SmallString<128> Model;
351  model.toVector(Model);
352  // Null terminate.
353  Model.c_str();
354
355  if (makeAbsolute) {
356    // Make model absolute by prepending a temp directory if it's not already.
357    bool absolute = path::is_absolute(Twine(Model));
358    if (!absolute) {
359      SmallString<128> TDir;
360      if (error_code ec = TempDir(TDir)) return ec;
361      path::append(TDir, Twine(Model));
362      Model.swap(TDir);
363    }
364  }
365
366  // Replace '%' with random chars. From here on, DO NOT modify model. It may be
367  // needed if the randomly chosen path already exists.
368  SmallString<128> RandomPath;
369  RandomPath.reserve(Model.size() + 1);
370  ::srand(::time(NULL));
371
372retry_random_path:
373  // This is opened here instead of above to make it easier to track when to
374  // close it. Collisions should be rare enough for the possible extra syscalls
375  // not to matter.
376  FILE *RandomSource = ::fopen("/dev/urandom", "r");
377  RandomPath.set_size(0);
378  for (SmallVectorImpl<char>::const_iterator i = Model.begin(),
379                                             e = Model.end(); i != e; ++i) {
380    if (*i == '%') {
381      char val = 0;
382      if (RandomSource)
383        val = fgetc(RandomSource);
384      else
385        val = ::rand();
386      RandomPath.push_back("0123456789abcdef"[val & 15]);
387    } else
388      RandomPath.push_back(*i);
389  }
390
391  if (RandomSource)
392    ::fclose(RandomSource);
393
394  // Try to open + create the file.
395rety_open_create:
396  int RandomFD = ::open(RandomPath.c_str(), O_RDWR | O_CREAT | O_EXCL, 0600);
397  if (RandomFD == -1) {
398    // If the file existed, try again, otherwise, error.
399    if (errno == errc::file_exists)
400      goto retry_random_path;
401    // The path prefix doesn't exist.
402    if (errno == errc::no_such_file_or_directory) {
403      StringRef p(RandomPath.begin(), RandomPath.size());
404      SmallString<64> dir_to_create;
405      for (path::const_iterator i = path::begin(p),
406                                e = --path::end(p); i != e; ++i) {
407        path::append(dir_to_create, *i);
408        bool Exists;
409        if (error_code ec = exists(Twine(dir_to_create), Exists)) return ec;
410        if (!Exists) {
411          // Don't try to create network paths.
412          if (i->size() > 2 && (*i)[0] == '/' &&
413                               (*i)[1] == '/' &&
414                               (*i)[2] != '/')
415            return make_error_code(errc::no_such_file_or_directory);
416          if (::mkdir(dir_to_create.c_str(), 0700) == -1)
417            return error_code(errno, system_category());
418        }
419      }
420      goto rety_open_create;
421    }
422    return error_code(errno, system_category());
423  }
424
425   // Make the path absolute.
426  char real_path_buff[PATH_MAX + 1];
427  if (realpath(RandomPath.c_str(), real_path_buff) == NULL) {
428    int error = errno;
429    ::close(RandomFD);
430    ::unlink(RandomPath.c_str());
431    return error_code(error, system_category());
432  }
433
434  result_path.clear();
435  StringRef d(real_path_buff);
436  result_path.append(d.begin(), d.end());
437
438  result_fd = RandomFD;
439  return success;
440}
441
442error_code directory_iterator_construct(directory_iterator &it, StringRef path){
443  SmallString<128> path_null(path);
444  DIR *directory = ::opendir(path_null.c_str());
445  if (directory == 0)
446    return error_code(errno, system_category());
447
448  it.IterationHandle = reinterpret_cast<intptr_t>(directory);
449  // Add something for replace_filename to replace.
450  path::append(path_null, ".");
451  it.CurrentEntry = directory_entry(path_null.str());
452  return directory_iterator_increment(it);
453}
454
455error_code directory_iterator_destruct(directory_iterator& it) {
456  if (it.IterationHandle)
457    ::closedir(reinterpret_cast<DIR *>(it.IterationHandle));
458  it.IterationHandle = 0;
459  it.CurrentEntry = directory_entry();
460  return success;
461}
462
463error_code directory_iterator_increment(directory_iterator& it) {
464  errno = 0;
465  dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
466  if (cur_dir == 0 && errno != 0) {
467    return error_code(errno, system_category());
468  } else if (cur_dir != 0) {
469    StringRef name(cur_dir->d_name, NAMLEN(cur_dir));
470    if ((name.size() == 1 && name[0] == '.') ||
471        (name.size() == 2 && name[0] == '.' && name[1] == '.'))
472      return directory_iterator_increment(it);
473    it.CurrentEntry.replace_filename(name);
474  } else
475    return directory_iterator_destruct(it);
476
477  return success;
478}
479
480error_code get_magic(const Twine &path, uint32_t len,
481                     SmallVectorImpl<char> &result) {
482  SmallString<128> PathStorage;
483  StringRef Path = path.toNullTerminatedStringRef(PathStorage);
484  result.set_size(0);
485
486  // Open path.
487  std::FILE *file = std::fopen(Path.data(), "rb");
488  if (file == 0)
489    return error_code(errno, system_category());
490
491  // Reserve storage.
492  result.reserve(len);
493
494  // Read magic!
495  size_t size = std::fread(result.data(), 1, len, file);
496  if (std::ferror(file) != 0) {
497    std::fclose(file);
498    return error_code(errno, system_category());
499  } else if (size != result.size()) {
500    if (std::feof(file) != 0) {
501      std::fclose(file);
502      result.set_size(size);
503      return make_error_code(errc::value_too_large);
504    }
505  }
506  std::fclose(file);
507  result.set_size(len);
508  return success;
509}
510
511} // end namespace fs
512} // end namespace sys
513} // end namespace llvm
514