Path.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
1//===-- Path.cpp - Implement OS Path Concept ------------------------------===//
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 operating system Path API.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Support/Path.h"
15#include "llvm/Support/Endian.h"
16#include "llvm/Support/ErrorHandling.h"
17#include "llvm/Support/FileSystem.h"
18#include "llvm/Support/Process.h"
19#include <cctype>
20#include <cstdio>
21#include <cstring>
22#include <fcntl.h>
23
24#if !defined(_MSC_VER) && !defined(__MINGW32__)
25#include <unistd.h>
26#else
27#include <io.h>
28#endif
29
30using namespace llvm;
31
32namespace {
33  using llvm::StringRef;
34  using llvm::sys::path::is_separator;
35
36#ifdef LLVM_ON_WIN32
37  const char *separators = "\\/";
38  const char preferred_separator = '\\';
39#else
40  const char  separators = '/';
41  const char preferred_separator = '/';
42#endif
43
44  StringRef find_first_component(StringRef path) {
45    // Look for this first component in the following order.
46    // * empty (in this case we return an empty string)
47    // * either C: or {//,\\}net.
48    // * {/,\}
49    // * {.,..}
50    // * {file,directory}name
51
52    if (path.empty())
53      return path;
54
55#ifdef LLVM_ON_WIN32
56    // C:
57    if (path.size() >= 2 && std::isalpha(static_cast<unsigned char>(path[0])) &&
58        path[1] == ':')
59      return path.substr(0, 2);
60#endif
61
62    // //net
63    if ((path.size() > 2) &&
64        is_separator(path[0]) &&
65        path[0] == path[1] &&
66        !is_separator(path[2])) {
67      // Find the next directory separator.
68      size_t end = path.find_first_of(separators, 2);
69      return path.substr(0, end);
70    }
71
72    // {/,\}
73    if (is_separator(path[0]))
74      return path.substr(0, 1);
75
76    if (path.startswith(".."))
77      return path.substr(0, 2);
78
79    if (path[0] == '.')
80      return path.substr(0, 1);
81
82    // * {file,directory}name
83    size_t end = path.find_first_of(separators);
84    return path.substr(0, end);
85  }
86
87  size_t filename_pos(StringRef str) {
88    if (str.size() == 2 &&
89        is_separator(str[0]) &&
90        str[0] == str[1])
91      return 0;
92
93    if (str.size() > 0 && is_separator(str[str.size() - 1]))
94      return str.size() - 1;
95
96    size_t pos = str.find_last_of(separators, str.size() - 1);
97
98#ifdef LLVM_ON_WIN32
99    if (pos == StringRef::npos)
100      pos = str.find_last_of(':', str.size() - 2);
101#endif
102
103    if (pos == StringRef::npos ||
104        (pos == 1 && is_separator(str[0])))
105      return 0;
106
107    return pos + 1;
108  }
109
110  size_t root_dir_start(StringRef str) {
111    // case "c:/"
112#ifdef LLVM_ON_WIN32
113    if (str.size() > 2 &&
114        str[1] == ':' &&
115        is_separator(str[2]))
116      return 2;
117#endif
118
119    // case "//"
120    if (str.size() == 2 &&
121        is_separator(str[0]) &&
122        str[0] == str[1])
123      return StringRef::npos;
124
125    // case "//net"
126    if (str.size() > 3 &&
127        is_separator(str[0]) &&
128        str[0] == str[1] &&
129        !is_separator(str[2])) {
130      return str.find_first_of(separators, 2);
131    }
132
133    // case "/"
134    if (str.size() > 0 && is_separator(str[0]))
135      return 0;
136
137    return StringRef::npos;
138  }
139
140  size_t parent_path_end(StringRef path) {
141    size_t end_pos = filename_pos(path);
142
143    bool filename_was_sep = path.size() > 0 && is_separator(path[end_pos]);
144
145    // Skip separators except for root dir.
146    size_t root_dir_pos = root_dir_start(path.substr(0, end_pos));
147
148    while(end_pos > 0 &&
149          (end_pos - 1) != root_dir_pos &&
150          is_separator(path[end_pos - 1]))
151      --end_pos;
152
153    if (end_pos == 1 && root_dir_pos == 0 && filename_was_sep)
154      return StringRef::npos;
155
156    return end_pos;
157  }
158} // end unnamed namespace
159
160enum FSEntity {
161  FS_Dir,
162  FS_File,
163  FS_Name
164};
165
166// Implemented in Unix/Path.inc and Windows/Path.inc.
167static error_code TempDir(SmallVectorImpl<char> &result);
168
169static error_code createUniqueEntity(const Twine &Model, int &ResultFD,
170                                     SmallVectorImpl<char> &ResultPath,
171                                     bool MakeAbsolute, unsigned Mode,
172                                     FSEntity Type) {
173  SmallString<128> ModelStorage;
174  Model.toVector(ModelStorage);
175
176  if (MakeAbsolute) {
177    // Make model absolute by prepending a temp directory if it's not already.
178    if (!sys::path::is_absolute(Twine(ModelStorage))) {
179      SmallString<128> TDir;
180      if (error_code EC = TempDir(TDir))
181        return EC;
182      sys::path::append(TDir, Twine(ModelStorage));
183      ModelStorage.swap(TDir);
184    }
185  }
186
187  // From here on, DO NOT modify model. It may be needed if the randomly chosen
188  // path already exists.
189  ResultPath = ModelStorage;
190  // Null terminate.
191  ResultPath.push_back(0);
192  ResultPath.pop_back();
193
194retry_random_path:
195  // Replace '%' with random chars.
196  for (unsigned i = 0, e = ModelStorage.size(); i != e; ++i) {
197    if (ModelStorage[i] == '%')
198      ResultPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];
199  }
200
201  // Try to open + create the file.
202  switch (Type) {
203  case FS_File: {
204    if (error_code EC =
205            sys::fs::openFileForWrite(Twine(ResultPath.begin()), ResultFD,
206                                      sys::fs::F_RW | sys::fs::F_Excl, Mode)) {
207      if (EC == errc::file_exists)
208        goto retry_random_path;
209      return EC;
210    }
211
212    return error_code::success();
213  }
214
215  case FS_Name: {
216    bool Exists;
217    error_code EC = sys::fs::exists(ResultPath.begin(), Exists);
218    if (EC)
219      return EC;
220    if (Exists)
221      goto retry_random_path;
222    return error_code::success();
223  }
224
225  case FS_Dir: {
226    if (error_code EC = sys::fs::create_directory(ResultPath.begin(), false)) {
227      if (EC == errc::file_exists)
228        goto retry_random_path;
229      return EC;
230    }
231    return error_code::success();
232  }
233  }
234  llvm_unreachable("Invalid Type");
235}
236
237namespace llvm {
238namespace sys  {
239namespace path {
240
241const_iterator begin(StringRef path) {
242  const_iterator i;
243  i.Path      = path;
244  i.Component = find_first_component(path);
245  i.Position  = 0;
246  return i;
247}
248
249const_iterator end(StringRef path) {
250  const_iterator i;
251  i.Path      = path;
252  i.Position  = path.size();
253  return i;
254}
255
256const_iterator &const_iterator::operator++() {
257  assert(Position < Path.size() && "Tried to increment past end!");
258
259  // Increment Position to past the current component
260  Position += Component.size();
261
262  // Check for end.
263  if (Position == Path.size()) {
264    Component = StringRef();
265    return *this;
266  }
267
268  // Both POSIX and Windows treat paths that begin with exactly two separators
269  // specially.
270  bool was_net = Component.size() > 2 &&
271    is_separator(Component[0]) &&
272    Component[1] == Component[0] &&
273    !is_separator(Component[2]);
274
275  // Handle separators.
276  if (is_separator(Path[Position])) {
277    // Root dir.
278    if (was_net
279#ifdef LLVM_ON_WIN32
280        // c:/
281        || Component.endswith(":")
282#endif
283        ) {
284      Component = Path.substr(Position, 1);
285      return *this;
286    }
287
288    // Skip extra separators.
289    while (Position != Path.size() &&
290           is_separator(Path[Position])) {
291      ++Position;
292    }
293
294    // Treat trailing '/' as a '.'.
295    if (Position == Path.size()) {
296      --Position;
297      Component = ".";
298      return *this;
299    }
300  }
301
302  // Find next component.
303  size_t end_pos = Path.find_first_of(separators, Position);
304  Component = Path.slice(Position, end_pos);
305
306  return *this;
307}
308
309const_iterator &const_iterator::operator--() {
310  // If we're at the end and the previous char was a '/', return '.' unless
311  // we are the root path.
312  size_t root_dir_pos = root_dir_start(Path);
313  if (Position == Path.size() &&
314      Path.size() > root_dir_pos + 1 &&
315      is_separator(Path[Position - 1])) {
316    --Position;
317    Component = ".";
318    return *this;
319  }
320
321  // Skip separators unless it's the root directory.
322  size_t end_pos = Position;
323
324  while(end_pos > 0 &&
325        (end_pos - 1) != root_dir_pos &&
326        is_separator(Path[end_pos - 1]))
327    --end_pos;
328
329  // Find next separator.
330  size_t start_pos = filename_pos(Path.substr(0, end_pos));
331  Component = Path.slice(start_pos, end_pos);
332  Position = start_pos;
333  return *this;
334}
335
336bool const_iterator::operator==(const const_iterator &RHS) const {
337  return Path.begin() == RHS.Path.begin() &&
338         Position == RHS.Position;
339}
340
341bool const_iterator::operator!=(const const_iterator &RHS) const {
342  return !(*this == RHS);
343}
344
345ptrdiff_t const_iterator::operator-(const const_iterator &RHS) const {
346  return Position - RHS.Position;
347}
348
349const StringRef root_path(StringRef path) {
350  const_iterator b = begin(path),
351                 pos = b,
352                 e = end(path);
353  if (b != e) {
354    bool has_net = b->size() > 2 && is_separator((*b)[0]) && (*b)[1] == (*b)[0];
355    bool has_drive =
356#ifdef LLVM_ON_WIN32
357      b->endswith(":");
358#else
359      false;
360#endif
361
362    if (has_net || has_drive) {
363      if ((++pos != e) && is_separator((*pos)[0])) {
364        // {C:/,//net/}, so get the first two components.
365        return path.substr(0, b->size() + pos->size());
366      } else {
367        // just {C:,//net}, return the first component.
368        return *b;
369      }
370    }
371
372    // POSIX style root directory.
373    if (is_separator((*b)[0])) {
374      return *b;
375    }
376  }
377
378  return StringRef();
379}
380
381const StringRef root_name(StringRef path) {
382  const_iterator b = begin(path),
383                 e = end(path);
384  if (b != e) {
385    bool has_net = b->size() > 2 && is_separator((*b)[0]) && (*b)[1] == (*b)[0];
386    bool has_drive =
387#ifdef LLVM_ON_WIN32
388      b->endswith(":");
389#else
390      false;
391#endif
392
393    if (has_net || has_drive) {
394      // just {C:,//net}, return the first component.
395      return *b;
396    }
397  }
398
399  // No path or no name.
400  return StringRef();
401}
402
403const StringRef root_directory(StringRef path) {
404  const_iterator b = begin(path),
405                 pos = b,
406                 e = end(path);
407  if (b != e) {
408    bool has_net = b->size() > 2 && is_separator((*b)[0]) && (*b)[1] == (*b)[0];
409    bool has_drive =
410#ifdef LLVM_ON_WIN32
411      b->endswith(":");
412#else
413      false;
414#endif
415
416    if ((has_net || has_drive) &&
417        // {C:,//net}, skip to the next component.
418        (++pos != e) && is_separator((*pos)[0])) {
419      return *pos;
420    }
421
422    // POSIX style root directory.
423    if (!has_net && is_separator((*b)[0])) {
424      return *b;
425    }
426  }
427
428  // No path or no root.
429  return StringRef();
430}
431
432const StringRef relative_path(StringRef path) {
433  StringRef root = root_path(path);
434  return path.substr(root.size());
435}
436
437void append(SmallVectorImpl<char> &path, const Twine &a,
438                                         const Twine &b,
439                                         const Twine &c,
440                                         const Twine &d) {
441  SmallString<32> a_storage;
442  SmallString<32> b_storage;
443  SmallString<32> c_storage;
444  SmallString<32> d_storage;
445
446  SmallVector<StringRef, 4> components;
447  if (!a.isTriviallyEmpty()) components.push_back(a.toStringRef(a_storage));
448  if (!b.isTriviallyEmpty()) components.push_back(b.toStringRef(b_storage));
449  if (!c.isTriviallyEmpty()) components.push_back(c.toStringRef(c_storage));
450  if (!d.isTriviallyEmpty()) components.push_back(d.toStringRef(d_storage));
451
452  for (SmallVectorImpl<StringRef>::const_iterator i = components.begin(),
453                                                  e = components.end();
454                                                  i != e; ++i) {
455    bool path_has_sep = !path.empty() && is_separator(path[path.size() - 1]);
456    bool component_has_sep = !i->empty() && is_separator((*i)[0]);
457    bool is_root_name = has_root_name(*i);
458
459    if (path_has_sep) {
460      // Strip separators from beginning of component.
461      size_t loc = i->find_first_not_of(separators);
462      StringRef c = i->substr(loc);
463
464      // Append it.
465      path.append(c.begin(), c.end());
466      continue;
467    }
468
469    if (!component_has_sep && !(path.empty() || is_root_name)) {
470      // Add a separator.
471      path.push_back(preferred_separator);
472    }
473
474    path.append(i->begin(), i->end());
475  }
476}
477
478void append(SmallVectorImpl<char> &path,
479            const_iterator begin, const_iterator end) {
480  for (; begin != end; ++begin)
481    path::append(path, *begin);
482}
483
484const StringRef parent_path(StringRef path) {
485  size_t end_pos = parent_path_end(path);
486  if (end_pos == StringRef::npos)
487    return StringRef();
488  else
489    return path.substr(0, end_pos);
490}
491
492void remove_filename(SmallVectorImpl<char> &path) {
493  size_t end_pos = parent_path_end(StringRef(path.begin(), path.size()));
494  if (end_pos != StringRef::npos)
495    path.set_size(end_pos);
496}
497
498void replace_extension(SmallVectorImpl<char> &path, const Twine &extension) {
499  StringRef p(path.begin(), path.size());
500  SmallString<32> ext_storage;
501  StringRef ext = extension.toStringRef(ext_storage);
502
503  // Erase existing extension.
504  size_t pos = p.find_last_of('.');
505  if (pos != StringRef::npos && pos >= filename_pos(p))
506    path.set_size(pos);
507
508  // Append '.' if needed.
509  if (ext.size() > 0 && ext[0] != '.')
510    path.push_back('.');
511
512  // Append extension.
513  path.append(ext.begin(), ext.end());
514}
515
516void native(const Twine &path, SmallVectorImpl<char> &result) {
517  assert((!path.isSingleStringRef() ||
518          path.getSingleStringRef().data() != result.data()) &&
519         "path and result are not allowed to overlap!");
520  // Clear result.
521  result.clear();
522  path.toVector(result);
523  native(result);
524}
525
526void native(SmallVectorImpl<char> &path) {
527#ifdef LLVM_ON_WIN32
528  std::replace(path.begin(), path.end(), '/', '\\');
529#endif
530}
531
532const StringRef filename(StringRef path) {
533  return *(--end(path));
534}
535
536const StringRef stem(StringRef path) {
537  StringRef fname = filename(path);
538  size_t pos = fname.find_last_of('.');
539  if (pos == StringRef::npos)
540    return fname;
541  else
542    if ((fname.size() == 1 && fname == ".") ||
543        (fname.size() == 2 && fname == ".."))
544      return fname;
545    else
546      return fname.substr(0, pos);
547}
548
549const StringRef extension(StringRef path) {
550  StringRef fname = filename(path);
551  size_t pos = fname.find_last_of('.');
552  if (pos == StringRef::npos)
553    return StringRef();
554  else
555    if ((fname.size() == 1 && fname == ".") ||
556        (fname.size() == 2 && fname == ".."))
557      return StringRef();
558    else
559      return fname.substr(pos);
560}
561
562bool is_separator(char value) {
563  switch(value) {
564#ifdef LLVM_ON_WIN32
565    case '\\': // fall through
566#endif
567    case '/': return true;
568    default: return false;
569  }
570}
571
572void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result) {
573  result.clear();
574
575#if defined(_CS_DARWIN_USER_TEMP_DIR) && defined(_CS_DARWIN_USER_CACHE_DIR)
576  // On Darwin, use DARWIN_USER_TEMP_DIR or DARWIN_USER_CACHE_DIR.
577  // macros defined in <unistd.h> on darwin >= 9
578  int ConfName = erasedOnReboot? _CS_DARWIN_USER_TEMP_DIR
579                               : _CS_DARWIN_USER_CACHE_DIR;
580  size_t ConfLen = confstr(ConfName, 0, 0);
581  if (ConfLen > 0) {
582    do {
583      result.resize(ConfLen);
584      ConfLen = confstr(ConfName, result.data(), result.size());
585    } while (ConfLen > 0 && ConfLen != result.size());
586
587    if (ConfLen > 0) {
588      assert(result.back() == 0);
589      result.pop_back();
590      return;
591    }
592
593    result.clear();
594  }
595#endif
596
597  // Check whether the temporary directory is specified by an environment
598  // variable.
599  const char *EnvironmentVariable;
600#ifdef LLVM_ON_WIN32
601  EnvironmentVariable = "TEMP";
602#else
603  EnvironmentVariable = "TMPDIR";
604#endif
605  if (char *RequestedDir = getenv(EnvironmentVariable)) {
606    result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
607    return;
608  }
609
610  // Fall back to a system default.
611  const char *DefaultResult;
612#ifdef LLVM_ON_WIN32
613  (void)erasedOnReboot;
614  DefaultResult = "C:\\TEMP";
615#else
616  if (erasedOnReboot)
617    DefaultResult = "/tmp";
618  else
619    DefaultResult = "/var/tmp";
620#endif
621  result.append(DefaultResult, DefaultResult + strlen(DefaultResult));
622}
623
624bool has_root_name(const Twine &path) {
625  SmallString<128> path_storage;
626  StringRef p = path.toStringRef(path_storage);
627
628  return !root_name(p).empty();
629}
630
631bool has_root_directory(const Twine &path) {
632  SmallString<128> path_storage;
633  StringRef p = path.toStringRef(path_storage);
634
635  return !root_directory(p).empty();
636}
637
638bool has_root_path(const Twine &path) {
639  SmallString<128> path_storage;
640  StringRef p = path.toStringRef(path_storage);
641
642  return !root_path(p).empty();
643}
644
645bool has_relative_path(const Twine &path) {
646  SmallString<128> path_storage;
647  StringRef p = path.toStringRef(path_storage);
648
649  return !relative_path(p).empty();
650}
651
652bool has_filename(const Twine &path) {
653  SmallString<128> path_storage;
654  StringRef p = path.toStringRef(path_storage);
655
656  return !filename(p).empty();
657}
658
659bool has_parent_path(const Twine &path) {
660  SmallString<128> path_storage;
661  StringRef p = path.toStringRef(path_storage);
662
663  return !parent_path(p).empty();
664}
665
666bool has_stem(const Twine &path) {
667  SmallString<128> path_storage;
668  StringRef p = path.toStringRef(path_storage);
669
670  return !stem(p).empty();
671}
672
673bool has_extension(const Twine &path) {
674  SmallString<128> path_storage;
675  StringRef p = path.toStringRef(path_storage);
676
677  return !extension(p).empty();
678}
679
680bool is_absolute(const Twine &path) {
681  SmallString<128> path_storage;
682  StringRef p = path.toStringRef(path_storage);
683
684  bool rootDir = has_root_directory(p),
685#ifdef LLVM_ON_WIN32
686       rootName = has_root_name(p);
687#else
688       rootName = true;
689#endif
690
691  return rootDir && rootName;
692}
693
694bool is_relative(const Twine &path) {
695  return !is_absolute(path);
696}
697
698} // end namespace path
699
700namespace fs {
701
702error_code getUniqueID(const Twine Path, UniqueID &Result) {
703  file_status Status;
704  error_code EC = status(Path, Status);
705  if (EC)
706    return EC;
707  Result = Status.getUniqueID();
708  return error_code::success();
709}
710
711error_code createUniqueFile(const Twine &Model, int &ResultFd,
712                            SmallVectorImpl<char> &ResultPath, unsigned Mode) {
713  return createUniqueEntity(Model, ResultFd, ResultPath, false, Mode, FS_File);
714}
715
716error_code createUniqueFile(const Twine &Model,
717                            SmallVectorImpl<char> &ResultPath) {
718  int Dummy;
719  return createUniqueEntity(Model, Dummy, ResultPath, false, 0, FS_Name);
720}
721
722static error_code createTemporaryFile(const Twine &Model, int &ResultFD,
723                                      llvm::SmallVectorImpl<char> &ResultPath,
724                                      FSEntity Type) {
725  SmallString<128> Storage;
726  StringRef P = Model.toNullTerminatedStringRef(Storage);
727  assert(P.find_first_of(separators) == StringRef::npos &&
728         "Model must be a simple filename.");
729  // Use P.begin() so that createUniqueEntity doesn't need to recreate Storage.
730  return createUniqueEntity(P.begin(), ResultFD, ResultPath,
731                            true, owner_read | owner_write, Type);
732}
733
734static error_code
735createTemporaryFile(const Twine &Prefix, StringRef Suffix, int &ResultFD,
736                    llvm::SmallVectorImpl<char> &ResultPath,
737                    FSEntity Type) {
738  const char *Middle = Suffix.empty() ? "-%%%%%%" : "-%%%%%%.";
739  return createTemporaryFile(Prefix + Middle + Suffix, ResultFD, ResultPath,
740                             Type);
741}
742
743
744error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
745                               int &ResultFD,
746                               SmallVectorImpl<char> &ResultPath) {
747  return createTemporaryFile(Prefix, Suffix, ResultFD, ResultPath, FS_File);
748}
749
750error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
751                               SmallVectorImpl<char> &ResultPath) {
752  int Dummy;
753  return createTemporaryFile(Prefix, Suffix, Dummy, ResultPath, FS_Name);
754}
755
756
757// This is a mkdtemp with a different pattern. We use createUniqueEntity mostly
758// for consistency. We should try using mkdtemp.
759error_code createUniqueDirectory(const Twine &Prefix,
760                                 SmallVectorImpl<char> &ResultPath) {
761  int Dummy;
762  return createUniqueEntity(Prefix + "-%%%%%%", Dummy, ResultPath,
763                            true, 0, FS_Dir);
764}
765
766error_code make_absolute(SmallVectorImpl<char> &path) {
767  StringRef p(path.data(), path.size());
768
769  bool rootDirectory = path::has_root_directory(p),
770#ifdef LLVM_ON_WIN32
771       rootName = path::has_root_name(p);
772#else
773       rootName = true;
774#endif
775
776  // Already absolute.
777  if (rootName && rootDirectory)
778    return error_code::success();
779
780  // All of the following conditions will need the current directory.
781  SmallString<128> current_dir;
782  if (error_code ec = current_path(current_dir)) return ec;
783
784  // Relative path. Prepend the current directory.
785  if (!rootName && !rootDirectory) {
786    // Append path to the current directory.
787    path::append(current_dir, p);
788    // Set path to the result.
789    path.swap(current_dir);
790    return error_code::success();
791  }
792
793  if (!rootName && rootDirectory) {
794    StringRef cdrn = path::root_name(current_dir);
795    SmallString<128> curDirRootName(cdrn.begin(), cdrn.end());
796    path::append(curDirRootName, p);
797    // Set path to the result.
798    path.swap(curDirRootName);
799    return error_code::success();
800  }
801
802  if (rootName && !rootDirectory) {
803    StringRef pRootName      = path::root_name(p);
804    StringRef bRootDirectory = path::root_directory(current_dir);
805    StringRef bRelativePath  = path::relative_path(current_dir);
806    StringRef pRelativePath  = path::relative_path(p);
807
808    SmallString<128> res;
809    path::append(res, pRootName, bRootDirectory, bRelativePath, pRelativePath);
810    path.swap(res);
811    return error_code::success();
812  }
813
814  llvm_unreachable("All rootName and rootDirectory combinations should have "
815                   "occurred above!");
816}
817
818error_code create_directories(const Twine &Path, bool IgnoreExisting) {
819  SmallString<128> PathStorage;
820  StringRef P = Path.toStringRef(PathStorage);
821
822  // Be optimistic and try to create the directory
823  error_code EC = create_directory(P, IgnoreExisting);
824  // If we succeeded, or had any error other than the parent not existing, just
825  // return it.
826  if (EC != errc::no_such_file_or_directory)
827    return EC;
828
829  // We failed because of a no_such_file_or_directory, try to create the
830  // parent.
831  StringRef Parent = path::parent_path(P);
832  if (Parent.empty())
833    return EC;
834
835  if ((EC = create_directories(Parent)))
836      return EC;
837
838  return create_directory(P, IgnoreExisting);
839}
840
841bool exists(file_status status) {
842  return status_known(status) && status.type() != file_type::file_not_found;
843}
844
845bool status_known(file_status s) {
846  return s.type() != file_type::status_error;
847}
848
849bool is_directory(file_status status) {
850  return status.type() == file_type::directory_file;
851}
852
853error_code is_directory(const Twine &path, bool &result) {
854  file_status st;
855  if (error_code ec = status(path, st))
856    return ec;
857  result = is_directory(st);
858  return error_code::success();
859}
860
861bool is_regular_file(file_status status) {
862  return status.type() == file_type::regular_file;
863}
864
865error_code is_regular_file(const Twine &path, bool &result) {
866  file_status st;
867  if (error_code ec = status(path, st))
868    return ec;
869  result = is_regular_file(st);
870  return error_code::success();
871}
872
873bool is_other(file_status status) {
874  return exists(status) &&
875         !is_regular_file(status) &&
876         !is_directory(status);
877}
878
879void directory_entry::replace_filename(const Twine &filename, file_status st) {
880  SmallString<128> path(Path.begin(), Path.end());
881  path::remove_filename(path);
882  path::append(path, filename);
883  Path = path.str();
884  Status = st;
885}
886
887error_code has_magic(const Twine &path, const Twine &magic, bool &result) {
888  SmallString<32>  MagicStorage;
889  StringRef Magic = magic.toStringRef(MagicStorage);
890  SmallString<32> Buffer;
891
892  if (error_code ec = get_magic(path, Magic.size(), Buffer)) {
893    if (ec == errc::value_too_large) {
894      // Magic.size() > file_size(Path).
895      result = false;
896      return error_code::success();
897    }
898    return ec;
899  }
900
901  result = Magic == Buffer;
902  return error_code::success();
903}
904
905/// @brief Identify the magic in magic.
906  file_magic identify_magic(StringRef Magic) {
907  if (Magic.size() < 4)
908    return file_magic::unknown;
909  switch ((unsigned char)Magic[0]) {
910    case 0x00: {
911      // COFF short import library file
912      if (Magic[1] == (char)0x00 && Magic[2] == (char)0xff &&
913          Magic[3] == (char)0xff)
914        return file_magic::coff_import_library;
915      // Windows resource file
916      const char Expected[] = { 0, 0, 0, 0, '\x20', 0, 0, 0, '\xff' };
917      if (Magic.size() >= sizeof(Expected) &&
918          memcmp(Magic.data(), Expected, sizeof(Expected)) == 0)
919        return file_magic::windows_resource;
920      // 0x0000 = COFF unknown machine type
921      if (Magic[1] == 0)
922        return file_magic::coff_object;
923      break;
924    }
925    case 0xDE:  // 0x0B17C0DE = BC wraper
926      if (Magic[1] == (char)0xC0 && Magic[2] == (char)0x17 &&
927          Magic[3] == (char)0x0B)
928        return file_magic::bitcode;
929      break;
930    case 'B':
931      if (Magic[1] == 'C' && Magic[2] == (char)0xC0 && Magic[3] == (char)0xDE)
932        return file_magic::bitcode;
933      break;
934    case '!':
935      if (Magic.size() >= 8)
936        if (memcmp(Magic.data(),"!<arch>\n",8) == 0)
937          return file_magic::archive;
938      break;
939
940    case '\177':
941      if (Magic.size() >= 18 && Magic[1] == 'E' && Magic[2] == 'L' &&
942          Magic[3] == 'F') {
943        bool Data2MSB = Magic[5] == 2;
944        unsigned high = Data2MSB ? 16 : 17;
945        unsigned low  = Data2MSB ? 17 : 16;
946        if (Magic[high] == 0)
947          switch (Magic[low]) {
948            default: break;
949            case 1: return file_magic::elf_relocatable;
950            case 2: return file_magic::elf_executable;
951            case 3: return file_magic::elf_shared_object;
952            case 4: return file_magic::elf_core;
953          }
954      }
955      break;
956
957    case 0xCA:
958      if (Magic[1] == char(0xFE) && Magic[2] == char(0xBA) &&
959          Magic[3] == char(0xBE)) {
960        // This is complicated by an overlap with Java class files.
961        // See the Mach-O section in /usr/share/file/magic for details.
962        if (Magic.size() >= 8 && Magic[7] < 43)
963          return file_magic::macho_universal_binary;
964      }
965      break;
966
967      // The two magic numbers for mach-o are:
968      // 0xfeedface - 32-bit mach-o
969      // 0xfeedfacf - 64-bit mach-o
970    case 0xFE:
971    case 0xCE:
972    case 0xCF: {
973      uint16_t type = 0;
974      if (Magic[0] == char(0xFE) && Magic[1] == char(0xED) &&
975          Magic[2] == char(0xFA) &&
976          (Magic[3] == char(0xCE) || Magic[3] == char(0xCF))) {
977        /* Native endian */
978        if (Magic.size() >= 16) type = Magic[14] << 8 | Magic[15];
979      } else if ((Magic[0] == char(0xCE) || Magic[0] == char(0xCF)) &&
980                 Magic[1] == char(0xFA) && Magic[2] == char(0xED) &&
981                 Magic[3] == char(0xFE)) {
982        /* Reverse endian */
983        if (Magic.size() >= 14) type = Magic[13] << 8 | Magic[12];
984      }
985      switch (type) {
986        default: break;
987        case 1: return file_magic::macho_object;
988        case 2: return file_magic::macho_executable;
989        case 3: return file_magic::macho_fixed_virtual_memory_shared_lib;
990        case 4: return file_magic::macho_core;
991        case 5: return file_magic::macho_preload_executable;
992        case 6: return file_magic::macho_dynamically_linked_shared_lib;
993        case 7: return file_magic::macho_dynamic_linker;
994        case 8: return file_magic::macho_bundle;
995        case 9: return file_magic::macho_dynamic_linker;
996        case 10: return file_magic::macho_dsym_companion;
997      }
998      break;
999    }
1000    case 0xF0: // PowerPC Windows
1001    case 0x83: // Alpha 32-bit
1002    case 0x84: // Alpha 64-bit
1003    case 0x66: // MPS R4000 Windows
1004    case 0x50: // mc68K
1005    case 0x4c: // 80386 Windows
1006    case 0xc4: // ARMNT Windows
1007      if (Magic[1] == 0x01)
1008        return file_magic::coff_object;
1009
1010    case 0x90: // PA-RISC Windows
1011    case 0x68: // mc68K Windows
1012      if (Magic[1] == 0x02)
1013        return file_magic::coff_object;
1014      break;
1015
1016    case 0x4d: // Possible MS-DOS stub on Windows PE file
1017      if (Magic[1] == 0x5a) {
1018        uint32_t off =
1019          *reinterpret_cast<const support::ulittle32_t*>(Magic.data() + 0x3c);
1020        // PE/COFF file, either EXE or DLL.
1021        if (off < Magic.size() && memcmp(Magic.data() + off, "PE\0\0",4) == 0)
1022          return file_magic::pecoff_executable;
1023      }
1024      break;
1025
1026    case 0x64: // x86-64 Windows.
1027      if (Magic[1] == char(0x86))
1028        return file_magic::coff_object;
1029      break;
1030
1031    default:
1032      break;
1033  }
1034  return file_magic::unknown;
1035}
1036
1037error_code identify_magic(const Twine &path, file_magic &result) {
1038  SmallString<32> Magic;
1039  error_code ec = get_magic(path, Magic.capacity(), Magic);
1040  if (ec && ec != errc::value_too_large)
1041    return ec;
1042
1043  result = identify_magic(Magic);
1044  return error_code::success();
1045}
1046
1047error_code directory_entry::status(file_status &result) const {
1048  return fs::status(Path, result);
1049}
1050
1051} // end namespace fs
1052} // end namespace sys
1053} // end namespace llvm
1054
1055// Include the truly platform-specific parts.
1056#if defined(LLVM_ON_UNIX)
1057#include "Unix/Path.inc"
1058#endif
1059#if defined(LLVM_ON_WIN32)
1060#include "Windows/Path.inc"
1061#endif
1062