lib/Support/Path.cpp

   1 //===-- Path.cpp - Implement OS Path Concept ------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //  This file implements the operating system Path API.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/Support/Path.h"
  14 #include "llvm/ADT/ArrayRef.h"
  15 #include "llvm/Config/llvm-config.h"
  16 #include "llvm/Support/Endian.h"
  17 #include "llvm/Support/Errc.h"
  18 #include "llvm/Support/ErrorHandling.h"
  19 #include "llvm/Support/FileSystem.h"
  20 #include "llvm/Support/Process.h"
  21 #include "llvm/Support/Signals.h"
  22 #include <cctype>
  23 #include <cstring>
  24
  25 #if !defined(_MSC_VER) && !defined(__MINGW32__)
  26 #include <unistd.h>
  27 #else
  28 #include <io.h>
  29 #endif
  30
  31 using namespace llvm;
  32 using namespace llvm::support::endian;
  33
  34 namespace {
  35   using llvm::StringRef;
  36   using llvm::sys::path::is_separator;
  37   using llvm::sys::path::Style;
  38
  39   inline Style real_style(Style style) {
  40 #ifdef _WIN32
  41     return (style == Style::posix) ? Style::posix : Style::windows;
  42 #else
  43     return (style == Style::windows) ? Style::windows : Style::posix;
  44 #endif
  45   }
  46
  47   inline const char *separators(Style style) {
  48     if (real_style(style) == Style::windows)
  49       return "\\/";
  50     return "/";
  51   }
  52
  53   inline char preferred_separator(Style style) {
  54     if (real_style(style) == Style::windows)
  55       return '\\';
  56     return '/';
  57   }
  58
  59   StringRef find_first_component(StringRef path, Style style) {
  60     // Look for this first component in the following order.
  61     // * empty (in this case we return an empty string)
  62     // * either C: or {//,\\}net.
  63     // * {/,\}
  64     // * {file,directory}name
  65
  66     if (path.empty())
  67       return path;
  68
  69     if (real_style(style) == Style::windows) {
  70       // C:
  71       if (path.size() >= 2 &&
  72           std::isalpha(static_cast<unsigned char>(path[0])) && path[1] == ':')
  73         return path.substr(0, 2);
  74     }
  75
  76     // //net
  77     if ((path.size() > 2) && is_separator(path[0], style) &&
  78         path[0] == path[1] && !is_separator(path[2], style)) {
  79       // Find the next directory separator.
  80       size_t end = path.find_first_of(separators(style), 2);
  81       return path.substr(0, end);
  82     }
  83
  84     // {/,\}
  85     if (is_separator(path[0], style))
  86       return path.substr(0, 1);
  87
  88     // * {file,directory}name
  89     size_t end = path.find_first_of(separators(style));
  90     return path.substr(0, end);
  91   }
  92
  93   // Returns the first character of the filename in str. For paths ending in
  94   // '/', it returns the position of the '/'.
  95   size_t filename_pos(StringRef str, Style style) {
  96     if (str.size() > 0 && is_separator(str[str.size() - 1], style))
  97       return str.size() - 1;
  98
  99     size_t pos = str.find_last_of(separators(style), str.size() - 1);
 100
 101     if (real_style(style) == Style::windows) {
 102       if (pos == StringRef::npos)
 103         pos = str.find_last_of(':', str.size() - 2);
 104     }
 105
 106     if (pos == StringRef::npos || (pos == 1 && is_separator(str[0], style)))
 107       return 0;
 108
 109     return pos + 1;
 110   }
 111
 112   // Returns the position of the root directory in str. If there is no root
 113   // directory in str, it returns StringRef::npos.
 114   size_t root_dir_start(StringRef str, Style style) {
 115     // case "c:/"
 116     if (real_style(style) == Style::windows) {
 117       if (str.size() > 2 && str[1] == ':' && is_separator(str[2], style))
 118         return 2;
 119     }
 120
 121     // case "//net"
 122     if (str.size() > 3 && is_separator(str[0], style) && str[0] == str[1] &&
 123         !is_separator(str[2], style)) {
 124       return str.find_first_of(separators(style), 2);
 125     }
 126
 127     // case "/"
 128     if (str.size() > 0 && is_separator(str[0], style))
 129       return 0;
 130
 131     return StringRef::npos;
 132   }
 133
 134   // Returns the position past the end of the "parent path" of path. The parent
 135   // path will not end in '/', unless the parent is the root directory. If the
 136   // path has no parent, 0 is returned.
 137   size_t parent_path_end(StringRef path, Style style) {
 138     size_t end_pos = filename_pos(path, style);
 139
 140     bool filename_was_sep =
 141         path.size() > 0 && is_separator(path[end_pos], style);
 142
 143     // Skip separators until we reach root dir (or the start of the string).
 144     size_t root_dir_pos = root_dir_start(path, style);
 145     while (end_pos > 0 &&
 146            (root_dir_pos == StringRef::npos || end_pos > root_dir_pos) &&
 147            is_separator(path[end_pos - 1], style))
 148       --end_pos;
 149
 150     if (end_pos == root_dir_pos && !filename_was_sep) {
 151       // We've reached the root dir and the input path was *not* ending in a
 152       // sequence of slashes. Include the root dir in the parent path.
 153       return root_dir_pos + 1;
 154     }
 155
 156     // Otherwise, just include before the last slash.
 157     return end_pos;
 158   }
 159 } // end unnamed namespace
 160
 161 enum FSEntity {
 162   FS_Dir,
 163   FS_File,
 164   FS_Name
 165 };
 166
 167 static std::error_code
 168 createUniqueEntity(const Twine &Model, int &ResultFD,
 169                    SmallVectorImpl<char> &ResultPath, bool MakeAbsolute,
 170                    unsigned Mode, FSEntity Type,
 171                    sys::fs::OpenFlags Flags = sys::fs::OF_None) {
 172
 173   // Limit the number of attempts we make, so that we don't infinite loop. E.g.
 174   // "permission denied" could be for a specific file (so we retry with a
 175   // different name) or for the whole directory (retry would always fail).
 176   // Checking which is racy, so we try a number of times, then give up.
 177   std::error_code EC;
 178   for (int Retries = 128; Retries > 0; --Retries) {
 179     sys::fs::createUniquePath(Model, ResultPath, MakeAbsolute);
 180     // Try to open + create the file.
 181     switch (Type) {
 182     case FS_File: {
 183       EC = sys::fs::openFileForReadWrite(Twine(ResultPath.begin()), ResultFD,
 184                                          sys::fs::CD_CreateNew, Flags, Mode);
 185       if (EC) {
 186         // errc::permission_denied happens on Windows when we try to open a file
 187         // that has been marked for deletion.
 188         if (EC == errc::file_exists || EC == errc::permission_denied)
 189           continue;
 190         return EC;
 191       }
 192
 193       return std::error_code();
 194     }
 195
 196     case FS_Name: {
 197       EC = sys::fs::access(ResultPath.begin(), sys::fs::AccessMode::Exist);
 198       if (EC == errc::no_such_file_or_directory)
 199         return std::error_code();
 200       if (EC)
 201         return EC;
 202       continue;
 203     }
 204
 205     case FS_Dir: {
 206       EC = sys::fs::create_directory(ResultPath.begin(), false);
 207       if (EC) {
 208         if (EC == errc::file_exists)
 209           continue;
 210         return EC;
 211       }
 212       return std::error_code();
 213     }
 214     }
 215     llvm_unreachable("Invalid Type");
 216   }
 217   return EC;
 218 }
 219
 220 namespace llvm {
 221 namespace sys  {
 222 namespace path {
 223
 224 const_iterator begin(StringRef path, Style style) {
 225   const_iterator i;
 226   i.Path      = path;
 227   i.Component = find_first_component(path, style);
 228   i.Position  = 0;
 229   i.S = style;
 230   return i;
 231 }
 232
 233 const_iterator end(StringRef path) {
 234   const_iterator i;
 235   i.Path      = path;
 236   i.Position  = path.size();
 237   return i;
 238 }
 239
 240 const_iterator &const_iterator::operator++() {
 241   assert(Position < Path.size() && "Tried to increment past end!");
 242
 243   // Increment Position to past the current component
 244   Position += Component.size();
 245
 246   // Check for end.
 247   if (Position == Path.size()) {
 248     Component = StringRef();
 249     return *this;
 250   }
 251
 252   // Both POSIX and Windows treat paths that begin with exactly two separators
 253   // specially.
 254   bool was_net = Component.size() > 2 && is_separator(Component[0], S) &&
 255                  Component[1] == Component[0] && !is_separator(Component[2], S);
 256
 257   // Handle separators.
 258   if (is_separator(Path[Position], S)) {
 259     // Root dir.
 260     if (was_net ||
 261         // c:/
 262         (real_style(S) == Style::windows && Component.endswith(":"))) {
 263       Component = Path.substr(Position, 1);
 264       return *this;
 265     }
 266
 267     // Skip extra separators.
 268     while (Position != Path.size() && is_separator(Path[Position], S)) {
 269       ++Position;
 270     }
 271
 272     // Treat trailing '/' as a '.', unless it is the root dir.
 273     if (Position == Path.size() && Component != "/") {
 274       --Position;
 275       Component = ".";
 276       return *this;
 277     }
 278   }
 279
 280   // Find next component.
 281   size_t end_pos = Path.find_first_of(separators(S), Position);
 282   Component = Path.slice(Position, end_pos);
 283
 284   return *this;
 285 }
 286
 287 bool const_iterator::operator==(const const_iterator &RHS) const {
 288   return Path.begin() == RHS.Path.begin() && Position == RHS.Position;
 289 }
 290
 291 ptrdiff_t const_iterator::operator-(const const_iterator &RHS) const {
 292   return Position - RHS.Position;
 293 }
 294
 295 reverse_iterator rbegin(StringRef Path, Style style) {
 296   reverse_iterator I;
 297   I.Path = Path;
 298   I.Position = Path.size();
 299   I.S = style;
 300   ++I;
 301   return I;
 302 }
 303
 304 reverse_iterator rend(StringRef Path) {
 305   reverse_iterator I;
 306   I.Path = Path;
 307   I.Component = Path.substr(0, 0);
 308   I.Position = 0;
 309   return I;
 310 }
 311
 312 reverse_iterator &reverse_iterator::operator++() {
 313   size_t root_dir_pos = root_dir_start(Path, S);
 314
 315   // Skip separators unless it's the root directory.
 316   size_t end_pos = Position;
 317   while (end_pos > 0 && (end_pos - 1) != root_dir_pos &&
 318          is_separator(Path[end_pos - 1], S))
 319     --end_pos;
 320
 321   // Treat trailing '/' as a '.', unless it is the root dir.
 322   if (Position == Path.size() && !Path.empty() &&
 323       is_separator(Path.back(), S) &&
 324       (root_dir_pos == StringRef::npos || end_pos - 1 > root_dir_pos)) {
 325     --Position;
 326     Component = ".";
 327     return *this;
 328   }
 329
 330   // Find next separator.
 331   size_t start_pos = filename_pos(Path.substr(0, end_pos), S);
 332   Component = Path.slice(start_pos, end_pos);
 333   Position = start_pos;
 334   return *this;
 335 }
 336
 337 bool reverse_iterator::operator==(const reverse_iterator &RHS) const {
 338   return Path.begin() == RHS.Path.begin() && Component == RHS.Component &&
 339          Position == RHS.Position;
 340 }
 341
 342 ptrdiff_t reverse_iterator::operator-(const reverse_iterator &RHS) const {
 343   return Position - RHS.Position;
 344 }
 345
 346 StringRef root_path(StringRef path, Style style) {
 347   const_iterator b = begin(path, style), pos = b, e = end(path);
 348   if (b != e) {
 349     bool has_net =
 350         b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0];
 351     bool has_drive = (real_style(style) == Style::windows) && b->endswith(":");
 352
 353     if (has_net || has_drive) {
 354       if ((++pos != e) && is_separator((*pos)[0], style)) {
 355         // {C:/,//net/}, so get the first two components.
 356         return path.substr(0, b->size() + pos->size());
 357       } else {
 358         // just {C:,//net}, return the first component.
 359         return *b;
 360       }
 361     }
 362
 363     // POSIX style root directory.
 364     if (is_separator((*b)[0], style)) {
 365       return *b;
 366     }
 367   }
 368
 369   return StringRef();
 370 }
 371
 372 StringRef root_name(StringRef path, Style style) {
 373   const_iterator b = begin(path, style), e = end(path);
 374   if (b != e) {
 375     bool has_net =
 376         b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0];
 377     bool has_drive = (real_style(style) == Style::windows) && b->endswith(":");
 378
 379     if (has_net || has_drive) {
 380       // just {C:,//net}, return the first component.
 381       return *b;
 382     }
 383   }
 384
 385   // No path or no name.
 386   return StringRef();
 387 }
 388
 389 StringRef root_directory(StringRef path, Style style) {
 390   const_iterator b = begin(path, style), pos = b, e = end(path);
 391   if (b != e) {
 392     bool has_net =
 393         b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0];
 394     bool has_drive = (real_style(style) == Style::windows) && b->endswith(":");
 395
 396     if ((has_net || has_drive) &&
 397         // {C:,//net}, skip to the next component.
 398         (++pos != e) && is_separator((*pos)[0], style)) {
 399       return *pos;
 400     }
 401
 402     // POSIX style root directory.
 403     if (!has_net && is_separator((*b)[0], style)) {
 404       return *b;
 405     }
 406   }
 407
 408   // No path or no root.
 409   return StringRef();
 410 }
 411
 412 StringRef relative_path(StringRef path, Style style) {
 413   StringRef root = root_path(path, style);
 414   return path.substr(root.size());
 415 }
 416
 417 void append(SmallVectorImpl<char> &path, Style style, const Twine &a,
 418             const Twine &b, const Twine &c, const Twine &d) {
 419   SmallString<32> a_storage;
 420   SmallString<32> b_storage;
 421   SmallString<32> c_storage;
 422   SmallString<32> d_storage;
 423
 424   SmallVector<StringRef, 4> components;
 425   if (!a.isTriviallyEmpty()) components.push_back(a.toStringRef(a_storage));
 426   if (!b.isTriviallyEmpty()) components.push_back(b.toStringRef(b_storage));
 427   if (!c.isTriviallyEmpty()) components.push_back(c.toStringRef(c_storage));
 428   if (!d.isTriviallyEmpty()) components.push_back(d.toStringRef(d_storage));
 429
 430   for (auto &component : components) {
 431     bool path_has_sep =
 432         !path.empty() && is_separator(path[path.size() - 1], style);
 433     if (path_has_sep) {
 434       // Strip separators from beginning of component.
 435       size_t loc = component.find_first_not_of(separators(style));
 436       StringRef c = component.substr(loc);
 437
 438       // Append it.
 439       path.append(c.begin(), c.end());
 440       continue;
 441     }
 442
 443     bool component_has_sep =
 444         !component.empty() && is_separator(component[0], style);
 445     if (!component_has_sep &&
 446         !(path.empty() || has_root_name(component, style))) {
 447       // Add a separator.
 448       path.push_back(preferred_separator(style));
 449     }
 450
 451     path.append(component.begin(), component.end());
 452   }
 453 }
 454
 455 void append(SmallVectorImpl<char> &path, const Twine &a, const Twine &b,
 456             const Twine &c, const Twine &d) {
 457   append(path, Style::native, a, b, c, d);
 458 }
 459
 460 void append(SmallVectorImpl<char> &path, const_iterator begin,
 461             const_iterator end, Style style) {
 462   for (; begin != end; ++begin)
 463     path::append(path, style, *begin);
 464 }
 465
 466 StringRef parent_path(StringRef path, Style style) {
 467   size_t end_pos = parent_path_end(path, style);
 468   if (end_pos == StringRef::npos)
 469     return StringRef();
 470   else
 471     return path.substr(0, end_pos);
 472 }
 473
 474 void remove_filename(SmallVectorImpl<char> &path, Style style) {
 475   size_t end_pos = parent_path_end(StringRef(path.begin(), path.size()), style);
 476   if (end_pos != StringRef::npos)
 477     path.set_size(end_pos);
 478 }
 479
 480 void replace_extension(SmallVectorImpl<char> &path, const Twine &extension,
 481                        Style style) {
 482   StringRef p(path.begin(), path.size());
 483   SmallString<32> ext_storage;
 484   StringRef ext = extension.toStringRef(ext_storage);
 485
 486   // Erase existing extension.
 487   size_t pos = p.find_last_of('.');
 488   if (pos != StringRef::npos && pos >= filename_pos(p, style))
 489     path.set_size(pos);
 490
 491   // Append '.' if needed.
 492   if (ext.size() > 0 && ext[0] != '.')
 493     path.push_back('.');
 494
 495   // Append extension.
 496   path.append(ext.begin(), ext.end());
 497 }
 498
 499 void replace_path_prefix(SmallVectorImpl<char> &Path,
 500                          const StringRef &OldPrefix, const StringRef &NewPrefix,
 501                          Style style) {
 502   if (OldPrefix.empty() && NewPrefix.empty())
 503     return;
 504
 505   StringRef OrigPath(Path.begin(), Path.size());
 506   if (!OrigPath.startswith(OldPrefix))
 507     return;
 508
 509   // If prefixes have the same size we can simply copy the new one over.
 510   if (OldPrefix.size() == NewPrefix.size()) {
 511     llvm::copy(NewPrefix, Path.begin());
 512     return;
 513   }
 514
 515   StringRef RelPath = OrigPath.substr(OldPrefix.size());
 516   SmallString<256> NewPath;
 517   path::append(NewPath, style, NewPrefix);
 518   path::append(NewPath, style, RelPath);
 519   Path.swap(NewPath);
 520 }
 521
 522 void native(const Twine &path, SmallVectorImpl<char> &result, Style style) {
 523   assert((!path.isSingleStringRef() ||
 524           path.getSingleStringRef().data() != result.data()) &&
 525          "path and result are not allowed to overlap!");
 526   // Clear result.
 527   result.clear();
 528   path.toVector(result);
 529   native(result, style);
 530 }
 531
 532 void native(SmallVectorImpl<char> &Path, Style style) {
 533   if (Path.empty())
 534     return;
 535   if (real_style(style) == Style::windows) {
 536     std::replace(Path.begin(), Path.end(), '/', '\\');
 537     if (Path[0] == '~' && (Path.size() == 1 || is_separator(Path[1], style))) {
 538       SmallString<128> PathHome;
 539       home_directory(PathHome);
 540       PathHome.append(Path.begin() + 1, Path.end());
 541       Path = PathHome;
 542     }
 543   } else {
 544     for (auto PI = Path.begin(), PE = Path.end(); PI < PE; ++PI) {
 545       if (*PI == '\\') {
 546         auto PN = PI + 1;
 547         if (PN < PE && *PN == '\\')
 548           ++PI; // increment once, the for loop will move over the escaped slash
 549         else
 550           *PI = '/';
 551       }
 552     }
 553   }
 554 }
 555
 556 std::string convert_to_slash(StringRef path, Style style) {
 557   if (real_style(style) != Style::windows)
 558     return path;
 559
 560   std::string s = path.str();
 561   std::replace(s.begin(), s.end(), '\\', '/');
 562   return s;
 563 }
 564
 565 StringRef filename(StringRef path, Style style) { return *rbegin(path, style); }
 566
 567 StringRef stem(StringRef path, Style style) {
 568   StringRef fname = filename(path, style);
 569   size_t pos = fname.find_last_of('.');
 570   if (pos == StringRef::npos)
 571     return fname;
 572   else
 573     if ((fname.size() == 1 && fname == ".") ||
 574         (fname.size() == 2 && fname == ".."))
 575       return fname;
 576     else
 577       return fname.substr(0, pos);
 578 }
 579
 580 StringRef extension(StringRef path, Style style) {
 581   StringRef fname = filename(path, style);
 582   size_t pos = fname.find_last_of('.');
 583   if (pos == StringRef::npos)
 584     return StringRef();
 585   else
 586     if ((fname.size() == 1 && fname == ".") ||
 587         (fname.size() == 2 && fname == ".."))
 588       return StringRef();
 589     else
 590       return fname.substr(pos);
 591 }
 592
 593 bool is_separator(char value, Style style) {
 594   if (value == '/')
 595     return true;
 596   if (real_style(style) == Style::windows)
 597     return value == '\\';
 598   return false;
 599 }
 600
 601 StringRef get_separator(Style style) {
 602   if (real_style(style) == Style::windows)
 603     return "\\";
 604   return "/";
 605 }
 606
 607 bool has_root_name(const Twine &path, Style style) {
 608   SmallString<128> path_storage;
 609   StringRef p = path.toStringRef(path_storage);
 610
 611   return !root_name(p, style).empty();
 612 }
 613
 614 bool has_root_directory(const Twine &path, Style style) {
 615   SmallString<128> path_storage;
 616   StringRef p = path.toStringRef(path_storage);
 617
 618   return !root_directory(p, style).empty();
 619 }
 620
 621 bool has_root_path(const Twine &path, Style style) {
 622   SmallString<128> path_storage;
 623   StringRef p = path.toStringRef(path_storage);
 624
 625   return !root_path(p, style).empty();
 626 }
 627
 628 bool has_relative_path(const Twine &path, Style style) {
 629   SmallString<128> path_storage;
 630   StringRef p = path.toStringRef(path_storage);
 631
 632   return !relative_path(p, style).empty();
 633 }
 634
 635 bool has_filename(const Twine &path, Style style) {
 636   SmallString<128> path_storage;
 637   StringRef p = path.toStringRef(path_storage);
 638
 639   return !filename(p, style).empty();
 640 }
 641
 642 bool has_parent_path(const Twine &path, Style style) {
 643   SmallString<128> path_storage;
 644   StringRef p = path.toStringRef(path_storage);
 645
 646   return !parent_path(p, style).empty();
 647 }
 648
 649 bool has_stem(const Twine &path, Style style) {
 650   SmallString<128> path_storage;
 651   StringRef p = path.toStringRef(path_storage);
 652
 653   return !stem(p, style).empty();
 654 }
 655
 656 bool has_extension(const Twine &path, Style style) {
 657   SmallString<128> path_storage;
 658   StringRef p = path.toStringRef(path_storage);
 659
 660   return !extension(p, style).empty();
 661 }
 662
 663 bool is_absolute(const Twine &path, Style style) {
 664   SmallString<128> path_storage;
 665   StringRef p = path.toStringRef(path_storage);
 666
 667   bool rootDir = has_root_directory(p, style);
 668   bool rootName =
 669       (real_style(style) != Style::windows) || has_root_name(p, style);
 670
 671   return rootDir && rootName;
 672 }
 673
 674 bool is_relative(const Twine &path, Style style) {
 675   return !is_absolute(path, style);
 676 }
 677
 678 StringRef remove_leading_dotslash(StringRef Path, Style style) {
 679   // Remove leading "./" (or ".//" or "././" etc.)
 680   while (Path.size() > 2 && Path[0] == '.' && is_separator(Path[1], style)) {
 681     Path = Path.substr(2);
 682     while (Path.size() > 0 && is_separator(Path[0], style))
 683       Path = Path.substr(1);
 684   }
 685   return Path;
 686 }
 687
 688 static SmallString<256> remove_dots(StringRef path, bool remove_dot_dot,
 689                                     Style style) {
 690   SmallVector<StringRef, 16> components;
 691
 692   // Skip the root path, then look for traversal in the components.
 693   StringRef rel = path::relative_path(path, style);
 694   for (StringRef C :
 695        llvm::make_range(path::begin(rel, style), path::end(rel))) {
 696     if (C == ".")
 697       continue;
 698     // Leading ".." will remain in the path unless it's at the root.
 699     if (remove_dot_dot && C == "..") {
 700       if (!components.empty() && components.back() != "..") {
 701         components.pop_back();
 702         continue;
 703       }
 704       if (path::is_absolute(path, style))
 705         continue;
 706     }
 707     components.push_back(C);
 708   }
 709
 710   SmallString<256> buffer = path::root_path(path, style);
 711   for (StringRef C : components)
 712     path::append(buffer, style, C);
 713   return buffer;
 714 }
 715
 716 bool remove_dots(SmallVectorImpl<char> &path, bool remove_dot_dot,
 717                  Style style) {
 718   StringRef p(path.data(), path.size());
 719
 720   SmallString<256> result = remove_dots(p, remove_dot_dot, style);
 721   if (result == path)
 722     return false;
 723
 724   path.swap(result);
 725   return true;
 726 }
 727
 728 } // end namespace path
 729
 730 namespace fs {
 731
 732 std::error_code getUniqueID(const Twine Path, UniqueID &Result) {
 733   file_status Status;
 734   std::error_code EC = status(Path, Status);
 735   if (EC)
 736     return EC;
 737   Result = Status.getUniqueID();
 738   return std::error_code();
 739 }
 740
 741 void createUniquePath(const Twine &Model, SmallVectorImpl<char> &ResultPath,
 742                       bool MakeAbsolute) {
 743   SmallString<128> ModelStorage;
 744   Model.toVector(ModelStorage);
 745
 746   if (MakeAbsolute) {
 747     // Make model absolute by prepending a temp directory if it's not already.
 748     if (!sys::path::is_absolute(Twine(ModelStorage))) {
 749       SmallString<128> TDir;
 750       sys::path::system_temp_directory(true, TDir);
 751       sys::path::append(TDir, Twine(ModelStorage));
 752       ModelStorage.swap(TDir);
 753     }
 754   }
 755
 756   ResultPath = ModelStorage;
 757   ResultPath.push_back(0);
 758   ResultPath.pop_back();
 759
 760   // Replace '%' with random chars.
 761   for (unsigned i = 0, e = ModelStorage.size(); i != e; ++i) {
 762     if (ModelStorage[i] == '%')
 763       ResultPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];
 764   }
 765 }
 766
 767 std::error_code createUniqueFile(const Twine &Model, int &ResultFd,
 768                                  SmallVectorImpl<char> &ResultPath,
 769                                  unsigned Mode) {
 770   return createUniqueEntity(Model, ResultFd, ResultPath, false, Mode, FS_File);
 771 }
 772
 773 static std::error_code createUniqueFile(const Twine &Model, int &ResultFd,
 774                                         SmallVectorImpl<char> &ResultPath,
 775                                         unsigned Mode, OpenFlags Flags) {
 776   return createUniqueEntity(Model, ResultFd, ResultPath, false, Mode, FS_File,
 777                             Flags);
 778 }
 779
 780 std::error_code createUniqueFile(const Twine &Model,
 781                                  SmallVectorImpl<char> &ResultPath,
 782                                  unsigned Mode) {
 783   int FD;
 784   auto EC = createUniqueFile(Model, FD, ResultPath, Mode);
 785   if (EC)
 786     return EC;
 787   // FD is only needed to avoid race conditions. Close it right away.
 788   close(FD);
 789   return EC;
 790 }
 791
 792 static std::error_code
 793 createTemporaryFile(const Twine &Model, int &ResultFD,
 794                     llvm::SmallVectorImpl<char> &ResultPath, FSEntity Type) {
 795   SmallString<128> Storage;
 796   StringRef P = Model.toNullTerminatedStringRef(Storage);
 797   assert(P.find_first_of(separators(Style::native)) == StringRef::npos &&
 798          "Model must be a simple filename.");
 799   // Use P.begin() so that createUniqueEntity doesn't need to recreate Storage.
 800   return createUniqueEntity(P.begin(), ResultFD, ResultPath, true,
 801                             owner_read | owner_write, Type);
 802 }
 803
 804 static std::error_code
 805 createTemporaryFile(const Twine &Prefix, StringRef Suffix, int &ResultFD,
 806                     llvm::SmallVectorImpl<char> &ResultPath, FSEntity Type) {
 807   const char *Middle = Suffix.empty() ? "-%%%%%%" : "-%%%%%%.";
 808   return createTemporaryFile(Prefix + Middle + Suffix, ResultFD, ResultPath,
 809                              Type);
 810 }
 811
 812 std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
 813                                     int &ResultFD,
 814                                     SmallVectorImpl<char> &ResultPath) {
 815   return createTemporaryFile(Prefix, Suffix, ResultFD, ResultPath, FS_File);
 816 }
 817
 818 std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
 819                                     SmallVectorImpl<char> &ResultPath) {
 820   int FD;
 821   auto EC = createTemporaryFile(Prefix, Suffix, FD, ResultPath);
 822   if (EC)
 823     return EC;
 824   // FD is only needed to avoid race conditions. Close it right away.
 825   close(FD);
 826   return EC;
 827 }
 828
 829
 830 // This is a mkdtemp with a different pattern. We use createUniqueEntity mostly
 831 // for consistency. We should try using mkdtemp.
 832 std::error_code createUniqueDirectory(const Twine &Prefix,
 833                                       SmallVectorImpl<char> &ResultPath) {
 834   int Dummy;
 835   return createUniqueEntity(Prefix + "-%%%%%%", Dummy, ResultPath, true, 0,
 836                             FS_Dir);
 837 }
 838
 839 std::error_code
 840 getPotentiallyUniqueFileName(const Twine &Model,
 841                              SmallVectorImpl<char> &ResultPath) {
 842   int Dummy;
 843   return createUniqueEntity(Model, Dummy, ResultPath, false, 0, FS_Name);
 844 }
 845
 846 std::error_code
 847 getPotentiallyUniqueTempFileName(const Twine &Prefix, StringRef Suffix,
 848                                  SmallVectorImpl<char> &ResultPath) {
 849   int Dummy;
 850   return createTemporaryFile(Prefix, Suffix, Dummy, ResultPath, FS_Name);
 851 }
 852
 853 void make_absolute(const Twine &current_directory,
 854                    SmallVectorImpl<char> &path) {
 855   StringRef p(path.data(), path.size());
 856
 857   bool rootDirectory = path::has_root_directory(p);
 858   bool rootName = path::has_root_name(p);
 859
 860   // Already absolute.
 861   if ((rootName || real_style(Style::native) != Style::windows) &&
 862       rootDirectory)
 863     return;
 864
 865   // All of the following conditions will need the current directory.
 866   SmallString<128> current_dir;
 867   current_directory.toVector(current_dir);
 868
 869   // Relative path. Prepend the current directory.
 870   if (!rootName && !rootDirectory) {
 871     // Append path to the current directory.
 872     path::append(current_dir, p);
 873     // Set path to the result.
 874     path.swap(current_dir);
 875     return;
 876   }
 877
 878   if (!rootName && rootDirectory) {
 879     StringRef cdrn = path::root_name(current_dir);
 880     SmallString<128> curDirRootName(cdrn.begin(), cdrn.end());
 881     path::append(curDirRootName, p);
 882     // Set path to the result.
 883     path.swap(curDirRootName);
 884     return;
 885   }
 886
 887   if (rootName && !rootDirectory) {
 888     StringRef pRootName      = path::root_name(p);
 889     StringRef bRootDirectory = path::root_directory(current_dir);
 890     StringRef bRelativePath  = path::relative_path(current_dir);
 891     StringRef pRelativePath  = path::relative_path(p);
 892
 893     SmallString<128> res;
 894     path::append(res, pRootName, bRootDirectory, bRelativePath, pRelativePath);
 895     path.swap(res);
 896     return;
 897   }
 898
 899   llvm_unreachable("All rootName and rootDirectory combinations should have "
 900                    "occurred above!");
 901 }
 902
 903 std::error_code make_absolute(SmallVectorImpl<char> &path) {
 904   if (path::is_absolute(path))
 905     return {};
 906
 907   SmallString<128> current_dir;
 908   if (std::error_code ec = current_path(current_dir))
 909     return ec;
 910
 911   make_absolute(current_dir, path);
 912   return {};
 913 }
 914
 915 std::error_code create_directories(const Twine &Path, bool IgnoreExisting,
 916                                    perms Perms) {
 917   SmallString<128> PathStorage;
 918   StringRef P = Path.toStringRef(PathStorage);
 919
 920   // Be optimistic and try to create the directory
 921   std::error_code EC = create_directory(P, IgnoreExisting, Perms);
 922   // If we succeeded, or had any error other than the parent not existing, just
 923   // return it.
 924   if (EC != errc::no_such_file_or_directory)
 925     return EC;
 926
 927   // We failed because of a no_such_file_or_directory, try to create the
 928   // parent.
 929   StringRef Parent = path::parent_path(P);
 930   if (Parent.empty())
 931     return EC;
 932
 933   if ((EC = create_directories(Parent, IgnoreExisting, Perms)))
 934       return EC;
 935
 936   return create_directory(P, IgnoreExisting, Perms);
 937 }
 938
 939 static std::error_code copy_file_internal(int ReadFD, int WriteFD) {
 940   const size_t BufSize = 4096;
 941   char *Buf = new char[BufSize];
 942   int BytesRead = 0, BytesWritten = 0;
 943   for (;;) {
 944     BytesRead = read(ReadFD, Buf, BufSize);
 945     if (BytesRead <= 0)
 946       break;
 947     while (BytesRead) {
 948       BytesWritten = write(WriteFD, Buf, BytesRead);
 949       if (BytesWritten < 0)
 950         break;
 951       BytesRead -= BytesWritten;
 952     }
 953     if (BytesWritten < 0)
 954       break;
 955   }
 956   delete[] Buf;
 957
 958   if (BytesRead < 0 || BytesWritten < 0)
 959     return std::error_code(errno, std::generic_category());
 960   return std::error_code();
 961 }
 962
 963 #ifndef __APPLE__
 964 std::error_code copy_file(const Twine &From, const Twine &To) {
 965   int ReadFD, WriteFD;
 966   if (std::error_code EC = openFileForRead(From, ReadFD, OF_None))
 967     return EC;
 968   if (std::error_code EC =
 969           openFileForWrite(To, WriteFD, CD_CreateAlways, OF_None)) {
 970     close(ReadFD);
 971     return EC;
 972   }
 973
 974   std::error_code EC = copy_file_internal(ReadFD, WriteFD);
 975
 976   close(ReadFD);
 977   close(WriteFD);
 978
 979   return EC;
 980 }
 981 #endif
 982
 983 std::error_code copy_file(const Twine &From, int ToFD) {
 984   int ReadFD;
 985   if (std::error_code EC = openFileForRead(From, ReadFD, OF_None))
 986     return EC;
 987
 988   std::error_code EC = copy_file_internal(ReadFD, ToFD);
 989
 990   close(ReadFD);
 991
 992   return EC;
 993 }
 994
 995 ErrorOr<MD5::MD5Result> md5_contents(int FD) {
 996   MD5 Hash;
 997
 998   constexpr size_t BufSize = 4096;
 999   std::vector<uint8_t> Buf(BufSize);
1000   int BytesRead = 0;
1001   for (;;) {
1002     BytesRead = read(FD, Buf.data(), BufSize);
1003     if (BytesRead <= 0)
1004       break;
1005     Hash.update(makeArrayRef(Buf.data(), BytesRead));
1006   }
1007
1008   if (BytesRead < 0)
1009     return std::error_code(errno, std::generic_category());
1010   MD5::MD5Result Result;
1011   Hash.final(Result);
1012   return Result;
1013 }
1014
1015 ErrorOr<MD5::MD5Result> md5_contents(const Twine &Path) {
1016   int FD;
1017   if (auto EC = openFileForRead(Path, FD, OF_None))
1018     return EC;
1019
1020   auto Result = md5_contents(FD);
1021   close(FD);
1022   return Result;
1023 }
1024
1025 bool exists(const basic_file_status &status) {
1026   return status_known(status) && status.type() != file_type::file_not_found;
1027 }
1028
1029 bool status_known(const basic_file_status &s) {
1030   return s.type() != file_type::status_error;
1031 }
1032
1033 file_type get_file_type(const Twine &Path, bool Follow) {
1034   file_status st;
1035   if (status(Path, st, Follow))
1036     return file_type::status_error;
1037   return st.type();
1038 }
1039
1040 bool is_directory(const basic_file_status &status) {
1041   return status.type() == file_type::directory_file;
1042 }
1043
1044 std::error_code is_directory(const Twine &path, bool &result) {
1045   file_status st;
1046   if (std::error_code ec = status(path, st))
1047     return ec;
1048   result = is_directory(st);
1049   return std::error_code();
1050 }
1051
1052 bool is_regular_file(const basic_file_status &status) {
1053   return status.type() == file_type::regular_file;
1054 }
1055
1056 std::error_code is_regular_file(const Twine &path, bool &result) {
1057   file_status st;
1058   if (std::error_code ec = status(path, st))
1059     return ec;
1060   result = is_regular_file(st);
1061   return std::error_code();
1062 }
1063
1064 bool is_symlink_file(const basic_file_status &status) {
1065   return status.type() == file_type::symlink_file;
1066 }
1067
1068 std::error_code is_symlink_file(const Twine &path, bool &result) {
1069   file_status st;
1070   if (std::error_code ec = status(path, st, false))
1071     return ec;
1072   result = is_symlink_file(st);
1073   return std::error_code();
1074 }
1075
1076 bool is_other(const basic_file_status &status) {
1077   return exists(status) &&
1078          !is_regular_file(status) &&
1079          !is_directory(status);
1080 }
1081
1082 std::error_code is_other(const Twine &Path, bool &Result) {
1083   file_status FileStatus;
1084   if (std::error_code EC = status(Path, FileStatus))
1085     return EC;
1086   Result = is_other(FileStatus);
1087   return std::error_code();
1088 }
1089
1090 void directory_entry::replace_filename(const Twine &Filename, file_type Type,
1091                                        basic_file_status Status) {
1092   SmallString<128> PathStr = path::parent_path(Path);
1093   path::append(PathStr, Filename);
1094   this->Path = PathStr.str();
1095   this->Type = Type;
1096   this->Status = Status;
1097 }
1098
1099 ErrorOr<perms> getPermissions(const Twine &Path) {
1100   file_status Status;
1101   if (std::error_code EC = status(Path, Status))
1102     return EC;
1103
1104   return Status.permissions();
1105 }
1106
1107 } // end namespace fs
1108 } // end namespace sys
1109 } // end namespace llvm
1110
1111 // Include the truly platform-specific parts.
1112 #if defined(LLVM_ON_UNIX)
1113 #include "Unix/Path.inc"
1114 #endif
1115 #if defined(_WIN32)
1116 #include "Windows/Path.inc"
1117 #endif
1118
1119 namespace llvm {
1120 namespace sys {
1121 namespace fs {
1122 TempFile::TempFile(StringRef Name, int FD) : TmpName(Name), FD(FD) {}
1123 TempFile::TempFile(TempFile &&Other) { *this = std::move(Other); }
1124 TempFile &TempFile::operator=(TempFile &&Other) {
1125   TmpName = std::move(Other.TmpName);
1126   FD = Other.FD;
1127   Other.Done = true;
1128   Other.FD = -1;
1129   return *this;
1130 }
1131
1132 TempFile::~TempFile() { assert(Done); }
1133
1134 Error TempFile::discard() {
1135   Done = true;
1136   if (FD != -1 && close(FD) == -1) {
1137     std::error_code EC = std::error_code(errno, std::generic_category());
1138     return errorCodeToError(EC);
1139   }
1140   FD = -1;
1141
1142 #ifdef _WIN32
1143   // On windows closing will remove the file.
1144   TmpName = "";
1145   return Error::success();
1146 #else
1147   // Always try to close and remove.
1148   std::error_code RemoveEC;
1149   if (!TmpName.empty()) {
1150     RemoveEC = fs::remove(TmpName);
1151     sys::DontRemoveFileOnSignal(TmpName);
1152     if (!RemoveEC)
1153       TmpName = "";
1154   }
1155   return errorCodeToError(RemoveEC);
1156 #endif
1157 }
1158
1159 Error TempFile::keep(const Twine &Name) {
1160   assert(!Done);
1161   Done = true;
1162   // Always try to close and rename.
1163 #ifdef _WIN32
1164   // If we can't cancel the delete don't rename.
1165   auto H = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
1166   std::error_code RenameEC = setDeleteDisposition(H, false);
1167   if (!RenameEC) {
1168     RenameEC = rename_fd(FD, Name);
1169     // If rename failed because it's cross-device, copy instead
1170     if (RenameEC ==
1171       std::error_code(ERROR_NOT_SAME_DEVICE, std::system_category())) {
1172       RenameEC = copy_file(TmpName, Name);
1173       setDeleteDisposition(H, true);
1174     }
1175   }
1176
1177   // If we can't rename, discard the temporary file.
1178   if (RenameEC)
1179     setDeleteDisposition(H, true);
1180 #else
1181   std::error_code RenameEC = fs::rename(TmpName, Name);
1182   if (RenameEC) {
1183     // If we can't rename, try to copy to work around cross-device link issues.
1184     RenameEC = sys::fs::copy_file(TmpName, Name);
1185     // If we can't rename or copy, discard the temporary file.
1186     if (RenameEC)
1187       remove(TmpName);
1188   }
1189   sys::DontRemoveFileOnSignal(TmpName);
1190 #endif
1191
1192   if (!RenameEC)
1193     TmpName = "";
1194
1195   if (close(FD) == -1) {
1196     std::error_code EC(errno, std::generic_category());
1197     return errorCodeToError(EC);
1198   }
1199   FD = -1;
1200
1201   return errorCodeToError(RenameEC);
1202 }
1203
1204 Error TempFile::keep() {
1205   assert(!Done);
1206   Done = true;
1207
1208 #ifdef _WIN32
1209   auto H = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
1210   if (std::error_code EC = setDeleteDisposition(H, false))
1211     return errorCodeToError(EC);
1212 #else
1213   sys::DontRemoveFileOnSignal(TmpName);
1214 #endif
1215
1216   TmpName = "";
1217
1218   if (close(FD) == -1) {
1219     std::error_code EC(errno, std::generic_category());
1220     return errorCodeToError(EC);
1221   }
1222   FD = -1;
1223
1224   return Error::success();
1225 }
1226
1227 Expected<TempFile> TempFile::create(const Twine &Model, unsigned Mode) {
1228   int FD;
1229   SmallString<128> ResultPath;
1230   if (std::error_code EC =
1231           createUniqueFile(Model, FD, ResultPath, Mode, OF_Delete))
1232     return errorCodeToError(EC);
1233
1234   TempFile Ret(ResultPath, FD);
1235 #ifndef _WIN32
1236   if (sys::RemoveFileOnSignal(ResultPath)) {
1237     // Make sure we delete the file when RemoveFileOnSignal fails.
1238     consumeError(Ret.discard());
1239     std::error_code EC(errc::operation_not_permitted);
1240     return errorCodeToError(EC);
1241   }
1242 #endif
1243   return std::move(Ret);
1244 }
1245 }
1246
1247 } // end namsspace sys
1248 } // end namespace llvm