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   return ++I;
 301 }
 302
 303 reverse_iterator rend(StringRef Path) {
 304   reverse_iterator I;
 305   I.Path = Path;
 306   I.Component = Path.substr(0, 0);
 307   I.Position = 0;
 308   return I;
 309 }
 310
 311 reverse_iterator &reverse_iterator::operator++() {
 312   size_t root_dir_pos = root_dir_start(Path, S);
 313
 314   // Skip separators unless it's the root directory.
 315   size_t end_pos = Position;
 316   while (end_pos > 0 && (end_pos - 1) != root_dir_pos &&
 317          is_separator(Path[end_pos - 1], S))
 318     --end_pos;
 319
 320   // Treat trailing '/' as a '.', unless it is the root dir.
 321   if (Position == Path.size() && !Path.empty() &&
 322       is_separator(Path.back(), S) &&
 323       (root_dir_pos == StringRef::npos || end_pos - 1 > root_dir_pos)) {
 324     --Position;
 325     Component = ".";
 326     return *this;
 327   }
 328
 329   // Find next separator.
 330   size_t start_pos = filename_pos(Path.substr(0, end_pos), S);
 331   Component = Path.slice(start_pos, end_pos);
 332   Position = start_pos;
 333   return *this;
 334 }
 335
 336 bool reverse_iterator::operator==(const reverse_iterator &RHS) const {
 337   return Path.begin() == RHS.Path.begin() && Component == RHS.Component &&
 338          Position == RHS.Position;
 339 }
 340
 341 ptrdiff_t reverse_iterator::operator-(const reverse_iterator &RHS) const {
 342   return Position - RHS.Position;
 343 }
 344
 345 StringRef root_path(StringRef path, Style style) {
 346   const_iterator b = begin(path, style), pos = b, e = end(path);
 347   if (b != e) {
 348     bool has_net =
 349         b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0];
 350     bool has_drive = (real_style(style) == Style::windows) && b->endswith(":");
 351
 352     if (has_net || has_drive) {
 353       if ((++pos != e) && is_separator((*pos)[0], style)) {
 354         // {C:/,//net/}, so get the first two components.
 355         return path.substr(0, b->size() + pos->size());
 356       } else {
 357         // just {C:,//net}, return the first component.
 358         return *b;
 359       }
 360     }
 361
 362     // POSIX style root directory.
 363     if (is_separator((*b)[0], style)) {
 364       return *b;
 365     }
 366   }
 367
 368   return StringRef();
 369 }
 370
 371 StringRef root_name(StringRef path, Style style) {
 372   const_iterator b = begin(path, style), e = end(path);
 373   if (b != e) {
 374     bool has_net =
 375         b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0];
 376     bool has_drive = (real_style(style) == Style::windows) && b->endswith(":");
 377
 378     if (has_net || has_drive) {
 379       // just {C:,//net}, return the first component.
 380       return *b;
 381     }
 382   }
 383
 384   // No path or no name.
 385   return StringRef();
 386 }
 387
 388 StringRef root_directory(StringRef path, Style style) {
 389   const_iterator b = begin(path, style), pos = b, e = end(path);
 390   if (b != e) {
 391     bool has_net =
 392         b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0];
 393     bool has_drive = (real_style(style) == Style::windows) && b->endswith(":");
 394
 395     if ((has_net || has_drive) &&
 396         // {C:,//net}, skip to the next component.
 397         (++pos != e) && is_separator((*pos)[0], style)) {
 398       return *pos;
 399     }
 400
 401     // POSIX style root directory.
 402     if (!has_net && is_separator((*b)[0], style)) {
 403       return *b;
 404     }
 405   }
 406
 407   // No path or no root.
 408   return StringRef();
 409 }
 410
 411 StringRef relative_path(StringRef path, Style style) {
 412   StringRef root = root_path(path, style);
 413   return path.substr(root.size());
 414 }
 415
 416 void append(SmallVectorImpl<char> &path, Style style, const Twine &a,
 417             const Twine &b, const Twine &c, const Twine &d) {
 418   SmallString<32> a_storage;
 419   SmallString<32> b_storage;
 420   SmallString<32> c_storage;
 421   SmallString<32> d_storage;
 422
 423   SmallVector<StringRef, 4> components;
 424   if (!a.isTriviallyEmpty()) components.push_back(a.toStringRef(a_storage));
 425   if (!b.isTriviallyEmpty()) components.push_back(b.toStringRef(b_storage));
 426   if (!c.isTriviallyEmpty()) components.push_back(c.toStringRef(c_storage));
 427   if (!d.isTriviallyEmpty()) components.push_back(d.toStringRef(d_storage));
 428
 429   for (auto &component : components) {
 430     bool path_has_sep =
 431         !path.empty() && is_separator(path[path.size() - 1], style);
 432     if (path_has_sep) {
 433       // Strip separators from beginning of component.
 434       size_t loc = component.find_first_not_of(separators(style));
 435       StringRef c = component.substr(loc);
 436
 437       // Append it.
 438       path.append(c.begin(), c.end());
 439       continue;
 440     }
 441
 442     bool component_has_sep =
 443         !component.empty() && is_separator(component[0], style);
 444     if (!component_has_sep &&
 445         !(path.empty() || has_root_name(component, style))) {
 446       // Add a separator.
 447       path.push_back(preferred_separator(style));
 448     }
 449
 450     path.append(component.begin(), component.end());
 451   }
 452 }
 453
 454 void append(SmallVectorImpl<char> &path, const Twine &a, const Twine &b,
 455             const Twine &c, const Twine &d) {
 456   append(path, Style::native, a, b, c, d);
 457 }
 458
 459 void append(SmallVectorImpl<char> &path, const_iterator begin,
 460             const_iterator end, Style style) {
 461   for (; begin != end; ++begin)
 462     path::append(path, style, *begin);
 463 }
 464
 465 StringRef parent_path(StringRef path, Style style) {
 466   size_t end_pos = parent_path_end(path, style);
 467   if (end_pos == StringRef::npos)
 468     return StringRef();
 469   else
 470     return path.substr(0, end_pos);
 471 }
 472
 473 void remove_filename(SmallVectorImpl<char> &path, Style style) {
 474   size_t end_pos = parent_path_end(StringRef(path.begin(), path.size()), style);
 475   if (end_pos != StringRef::npos)
 476     path.set_size(end_pos);
 477 }
 478
 479 void replace_extension(SmallVectorImpl<char> &path, const Twine &extension,
 480                        Style style) {
 481   StringRef p(path.begin(), path.size());
 482   SmallString<32> ext_storage;
 483   StringRef ext = extension.toStringRef(ext_storage);
 484
 485   // Erase existing extension.
 486   size_t pos = p.find_last_of('.');
 487   if (pos != StringRef::npos && pos >= filename_pos(p, style))
 488     path.set_size(pos);
 489
 490   // Append '.' if needed.
 491   if (ext.size() > 0 && ext[0] != '.')
 492     path.push_back('.');
 493
 494   // Append extension.
 495   path.append(ext.begin(), ext.end());
 496 }
 497
 498 void replace_path_prefix(SmallVectorImpl<char> &Path,
 499                          const StringRef &OldPrefix, const StringRef &NewPrefix,
 500                          Style style) {
 501   if (OldPrefix.empty() && NewPrefix.empty())
 502     return;
 503
 504   StringRef OrigPath(Path.begin(), Path.size());
 505   if (!OrigPath.startswith(OldPrefix))
 506     return;
 507
 508   // If prefixes have the same size we can simply copy the new one over.
 509   if (OldPrefix.size() == NewPrefix.size()) {
 510     llvm::copy(NewPrefix, Path.begin());
 511     return;
 512   }
 513
 514   StringRef RelPath = OrigPath.substr(OldPrefix.size());
 515   SmallString<256> NewPath;
 516   path::append(NewPath, style, NewPrefix);
 517   path::append(NewPath, style, RelPath);
 518   Path.swap(NewPath);
 519 }
 520
 521 void native(const Twine &path, SmallVectorImpl<char> &result, Style style) {
 522   assert((!path.isSingleStringRef() ||
 523           path.getSingleStringRef().data() != result.data()) &&
 524          "path and result are not allowed to overlap!");
 525   // Clear result.
 526   result.clear();
 527   path.toVector(result);
 528   native(result, style);
 529 }
 530
 531 void native(SmallVectorImpl<char> &Path, Style style) {
 532   if (Path.empty())
 533     return;
 534   if (real_style(style) == Style::windows) {
 535     std::replace(Path.begin(), Path.end(), '/', '\\');
 536     if (Path[0] == '~' && (Path.size() == 1 || is_separator(Path[1], style))) {
 537       SmallString<128> PathHome;
 538       home_directory(PathHome);
 539       PathHome.append(Path.begin() + 1, Path.end());
 540       Path = PathHome;
 541     }
 542   } else {
 543     for (auto PI = Path.begin(), PE = Path.end(); PI < PE; ++PI) {
 544       if (*PI == '\\') {
 545         auto PN = PI + 1;
 546         if (PN < PE && *PN == '\\')
 547           ++PI; // increment once, the for loop will move over the escaped slash
 548         else
 549           *PI = '/';
 550       }
 551     }
 552   }
 553 }
 554
 555 std::string convert_to_slash(StringRef path, Style style) {
 556   if (real_style(style) != Style::windows)
 557     return path;
 558
 559   std::string s = path.str();
 560   std::replace(s.begin(), s.end(), '\\', '/');
 561   return s;
 562 }
 563
 564 StringRef filename(StringRef path, Style style) { return *rbegin(path, style); }
 565
 566 StringRef stem(StringRef path, Style style) {
 567   StringRef fname = filename(path, style);
 568   size_t pos = fname.find_last_of('.');
 569   if (pos == StringRef::npos)
 570     return fname;
 571   else
 572     if ((fname.size() == 1 && fname == ".") ||
 573         (fname.size() == 2 && fname == ".."))
 574       return fname;
 575     else
 576       return fname.substr(0, pos);
 577 }
 578
 579 StringRef extension(StringRef path, Style style) {
 580   StringRef fname = filename(path, style);
 581   size_t pos = fname.find_last_of('.');
 582   if (pos == StringRef::npos)
 583     return StringRef();
 584   else
 585     if ((fname.size() == 1 && fname == ".") ||
 586         (fname.size() == 2 && fname == ".."))
 587       return StringRef();
 588     else
 589       return fname.substr(pos);
 590 }
 591
 592 bool is_separator(char value, Style style) {
 593   if (value == '/')
 594     return true;
 595   if (real_style(style) == Style::windows)
 596     return value == '\\';
 597   return false;
 598 }
 599
 600 StringRef get_separator(Style style) {
 601   if (real_style(style) == Style::windows)
 602     return "\\";
 603   return "/";
 604 }
 605
 606 bool has_root_name(const Twine &path, Style style) {
 607   SmallString<128> path_storage;
 608   StringRef p = path.toStringRef(path_storage);
 609
 610   return !root_name(p, style).empty();
 611 }
 612
 613 bool has_root_directory(const Twine &path, Style style) {
 614   SmallString<128> path_storage;
 615   StringRef p = path.toStringRef(path_storage);
 616
 617   return !root_directory(p, style).empty();
 618 }
 619
 620 bool has_root_path(const Twine &path, Style style) {
 621   SmallString<128> path_storage;
 622   StringRef p = path.toStringRef(path_storage);
 623
 624   return !root_path(p, style).empty();
 625 }
 626
 627 bool has_relative_path(const Twine &path, Style style) {
 628   SmallString<128> path_storage;
 629   StringRef p = path.toStringRef(path_storage);
 630
 631   return !relative_path(p, style).empty();
 632 }
 633
 634 bool has_filename(const Twine &path, Style style) {
 635   SmallString<128> path_storage;
 636   StringRef p = path.toStringRef(path_storage);
 637
 638   return !filename(p, style).empty();
 639 }
 640
 641 bool has_parent_path(const Twine &path, Style style) {
 642   SmallString<128> path_storage;
 643   StringRef p = path.toStringRef(path_storage);
 644
 645   return !parent_path(p, style).empty();
 646 }
 647
 648 bool has_stem(const Twine &path, Style style) {
 649   SmallString<128> path_storage;
 650   StringRef p = path.toStringRef(path_storage);
 651
 652   return !stem(p, style).empty();
 653 }
 654
 655 bool has_extension(const Twine &path, Style style) {
 656   SmallString<128> path_storage;
 657   StringRef p = path.toStringRef(path_storage);
 658
 659   return !extension(p, style).empty();
 660 }
 661
 662 bool is_absolute(const Twine &path, Style style) {
 663   SmallString<128> path_storage;
 664   StringRef p = path.toStringRef(path_storage);
 665
 666   bool rootDir = has_root_directory(p, style);
 667   bool rootName =
 668       (real_style(style) != Style::windows) || has_root_name(p, style);
 669
 670   return rootDir && rootName;
 671 }
 672
 673 bool is_relative(const Twine &path, Style style) {
 674   return !is_absolute(path, style);
 675 }
 676
 677 StringRef remove_leading_dotslash(StringRef Path, Style style) {
 678   // Remove leading "./" (or ".//" or "././" etc.)
 679   while (Path.size() > 2 && Path[0] == '.' && is_separator(Path[1], style)) {
 680     Path = Path.substr(2);
 681     while (Path.size() > 0 && is_separator(Path[0], style))
 682       Path = Path.substr(1);
 683   }
 684   return Path;
 685 }
 686
 687 static SmallString<256> remove_dots(StringRef path, bool remove_dot_dot,
 688                                     Style style) {
 689   SmallVector<StringRef, 16> components;
 690
 691   // Skip the root path, then look for traversal in the components.
 692   StringRef rel = path::relative_path(path, style);
 693   for (StringRef C :
 694        llvm::make_range(path::begin(rel, style), path::end(rel))) {
 695     if (C == ".")
 696       continue;
 697     // Leading ".." will remain in the path unless it's at the root.
 698     if (remove_dot_dot && C == "..") {
 699       if (!components.empty() && components.back() != "..") {
 700         components.pop_back();
 701         continue;
 702       }
 703       if (path::is_absolute(path, style))
 704         continue;
 705     }
 706     components.push_back(C);
 707   }
 708
 709   SmallString<256> buffer = path::root_path(path, style);
 710   for (StringRef C : components)
 711     path::append(buffer, style, C);
 712   return buffer;
 713 }
 714
 715 bool remove_dots(SmallVectorImpl<char> &path, bool remove_dot_dot,
 716                  Style style) {
 717   StringRef p(path.data(), path.size());
 718
 719   SmallString<256> result = remove_dots(p, remove_dot_dot, style);
 720   if (result == path)
 721     return false;
 722
 723   path.swap(result);
 724   return true;
 725 }
 726
 727 } // end namespace path
 728
 729 namespace fs {
 730
 731 std::error_code getUniqueID(const Twine Path, UniqueID &Result) {
 732   file_status Status;
 733   std::error_code EC = status(Path, Status);
 734   if (EC)
 735     return EC;
 736   Result = Status.getUniqueID();
 737   return std::error_code();
 738 }
 739
 740 void createUniquePath(const Twine &Model, SmallVectorImpl<char> &ResultPath,
 741                       bool MakeAbsolute) {
 742   SmallString<128> ModelStorage;
 743   Model.toVector(ModelStorage);
 744
 745   if (MakeAbsolute) {
 746     // Make model absolute by prepending a temp directory if it's not already.
 747     if (!sys::path::is_absolute(Twine(ModelStorage))) {
 748       SmallString<128> TDir;
 749       sys::path::system_temp_directory(true, TDir);
 750       sys::path::append(TDir, Twine(ModelStorage));
 751       ModelStorage.swap(TDir);
 752     }
 753   }
 754
 755   ResultPath = ModelStorage;
 756   ResultPath.push_back(0);
 757   ResultPath.pop_back();
 758
 759   // Replace '%' with random chars.
 760   for (unsigned i = 0, e = ModelStorage.size(); i != e; ++i) {
 761     if (ModelStorage[i] == '%')
 762       ResultPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];
 763   }
 764 }
 765
 766 std::error_code createUniqueFile(const Twine &Model, int &ResultFd,
 767                                  SmallVectorImpl<char> &ResultPath,
 768                                  unsigned Mode) {
 769   return createUniqueEntity(Model, ResultFd, ResultPath, false, Mode, FS_File);
 770 }
 771
 772 static std::error_code createUniqueFile(const Twine &Model, int &ResultFd,
 773                                         SmallVectorImpl<char> &ResultPath,
 774                                         unsigned Mode, OpenFlags Flags) {
 775   return createUniqueEntity(Model, ResultFd, ResultPath, false, Mode, FS_File,
 776                             Flags);
 777 }
 778
 779 std::error_code createUniqueFile(const Twine &Model,
 780                                  SmallVectorImpl<char> &ResultPath,
 781                                  unsigned Mode) {
 782   int FD;
 783   auto EC = createUniqueFile(Model, FD, ResultPath, Mode);
 784   if (EC)
 785     return EC;
 786   // FD is only needed to avoid race conditions. Close it right away.
 787   close(FD);
 788   return EC;
 789 }
 790
 791 static std::error_code
 792 createTemporaryFile(const Twine &Model, int &ResultFD,
 793                     llvm::SmallVectorImpl<char> &ResultPath, FSEntity Type) {
 794   SmallString<128> Storage;
 795   StringRef P = Model.toNullTerminatedStringRef(Storage);
 796   assert(P.find_first_of(separators(Style::native)) == StringRef::npos &&
 797          "Model must be a simple filename.");
 798   // Use P.begin() so that createUniqueEntity doesn't need to recreate Storage.
 799   return createUniqueEntity(P.begin(), ResultFD, ResultPath, true,
 800                             owner_read | owner_write, Type);
 801 }
 802
 803 static std::error_code
 804 createTemporaryFile(const Twine &Prefix, StringRef Suffix, int &ResultFD,
 805                     llvm::SmallVectorImpl<char> &ResultPath, FSEntity Type) {
 806   const char *Middle = Suffix.empty() ? "-%%%%%%" : "-%%%%%%.";
 807   return createTemporaryFile(Prefix + Middle + Suffix, ResultFD, ResultPath,
 808                              Type);
 809 }
 810
 811 std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
 812                                     int &ResultFD,
 813                                     SmallVectorImpl<char> &ResultPath) {
 814   return createTemporaryFile(Prefix, Suffix, ResultFD, ResultPath, FS_File);
 815 }
 816
 817 std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
 818                                     SmallVectorImpl<char> &ResultPath) {
 819   int FD;
 820   auto EC = createTemporaryFile(Prefix, Suffix, FD, ResultPath);
 821   if (EC)
 822     return EC;
 823   // FD is only needed to avoid race conditions. Close it right away.
 824   close(FD);
 825   return EC;
 826 }
 827
 828
 829 // This is a mkdtemp with a different pattern. We use createUniqueEntity mostly
 830 // for consistency. We should try using mkdtemp.
 831 std::error_code createUniqueDirectory(const Twine &Prefix,
 832                                       SmallVectorImpl<char> &ResultPath) {
 833   int Dummy;
 834   return createUniqueEntity(Prefix + "-%%%%%%", Dummy, ResultPath, true, 0,
 835                             FS_Dir);
 836 }
 837
 838 std::error_code
 839 getPotentiallyUniqueFileName(const Twine &Model,
 840                              SmallVectorImpl<char> &ResultPath) {
 841   int Dummy;
 842   return createUniqueEntity(Model, Dummy, ResultPath, false, 0, FS_Name);
 843 }
 844
 845 std::error_code
 846 getPotentiallyUniqueTempFileName(const Twine &Prefix, StringRef Suffix,
 847                                  SmallVectorImpl<char> &ResultPath) {
 848   int Dummy;
 849   return createTemporaryFile(Prefix, Suffix, Dummy, ResultPath, FS_Name);
 850 }
 851
 852 void make_absolute(const Twine &current_directory,
 853                    SmallVectorImpl<char> &path) {
 854   StringRef p(path.data(), path.size());
 855
 856   bool rootDirectory = path::has_root_directory(p);
 857   bool rootName =
 858       (real_style(Style::native) != Style::windows) || path::has_root_name(p);
 859
 860   // Already absolute.
 861   if (rootName && rootDirectory)
 862     return;
 863
 864   // All of the following conditions will need the current directory.
 865   SmallString<128> current_dir;
 866   current_directory.toVector(current_dir);
 867
 868   // Relative path. Prepend the current directory.
 869   if (!rootName && !rootDirectory) {
 870     // Append path to the current directory.
 871     path::append(current_dir, p);
 872     // Set path to the result.
 873     path.swap(current_dir);
 874     return;
 875   }
 876
 877   if (!rootName && rootDirectory) {
 878     StringRef cdrn = path::root_name(current_dir);
 879     SmallString<128> curDirRootName(cdrn.begin(), cdrn.end());
 880     path::append(curDirRootName, p);
 881     // Set path to the result.
 882     path.swap(curDirRootName);
 883     return;
 884   }
 885
 886   if (rootName && !rootDirectory) {
 887     StringRef pRootName      = path::root_name(p);
 888     StringRef bRootDirectory = path::root_directory(current_dir);
 889     StringRef bRelativePath  = path::relative_path(current_dir);
 890     StringRef pRelativePath  = path::relative_path(p);
 891
 892     SmallString<128> res;
 893     path::append(res, pRootName, bRootDirectory, bRelativePath, pRelativePath);
 894     path.swap(res);
 895     return;
 896   }
 897
 898   llvm_unreachable("All rootName and rootDirectory combinations should have "
 899                    "occurred above!");
 900 }
 901
 902 std::error_code make_absolute(SmallVectorImpl<char> &path) {
 903   if (path::is_absolute(path))
 904     return {};
 905
 906   SmallString<128> current_dir;
 907   if (std::error_code ec = current_path(current_dir))
 908     return ec;
 909
 910   make_absolute(current_dir, path);
 911   return {};
 912 }
 913
 914 std::error_code create_directories(const Twine &Path, bool IgnoreExisting,
 915                                    perms Perms) {
 916   SmallString<128> PathStorage;
 917   StringRef P = Path.toStringRef(PathStorage);
 918
 919   // Be optimistic and try to create the directory
 920   std::error_code EC = create_directory(P, IgnoreExisting, Perms);
 921   // If we succeeded, or had any error other than the parent not existing, just
 922   // return it.
 923   if (EC != errc::no_such_file_or_directory)
 924     return EC;
 925
 926   // We failed because of a no_such_file_or_directory, try to create the
 927   // parent.
 928   StringRef Parent = path::parent_path(P);
 929   if (Parent.empty())
 930     return EC;
 931
 932   if ((EC = create_directories(Parent, IgnoreExisting, Perms)))
 933       return EC;
 934
 935   return create_directory(P, IgnoreExisting, Perms);
 936 }
 937
 938 static std::error_code copy_file_internal(int ReadFD, int WriteFD) {
 939   const size_t BufSize = 4096;
 940   char *Buf = new char[BufSize];
 941   int BytesRead = 0, BytesWritten = 0;
 942   for (;;) {
 943     BytesRead = read(ReadFD, Buf, BufSize);
 944     if (BytesRead <= 0)
 945       break;
 946     while (BytesRead) {
 947       BytesWritten = write(WriteFD, Buf, BytesRead);
 948       if (BytesWritten < 0)
 949         break;
 950       BytesRead -= BytesWritten;
 951     }
 952     if (BytesWritten < 0)
 953       break;
 954   }
 955   delete[] Buf;
 956
 957   if (BytesRead < 0 || BytesWritten < 0)
 958     return std::error_code(errno, std::generic_category());
 959   return std::error_code();
 960 }
 961
 962 std::error_code copy_file(const Twine &From, const Twine &To) {
 963   int ReadFD, WriteFD;
 964   if (std::error_code EC = openFileForRead(From, ReadFD, OF_None))
 965     return EC;
 966   if (std::error_code EC =
 967           openFileForWrite(To, WriteFD, CD_CreateAlways, OF_None)) {
 968     close(ReadFD);
 969     return EC;
 970   }
 971
 972   std::error_code EC = copy_file_internal(ReadFD, WriteFD);
 973
 974   close(ReadFD);
 975   close(WriteFD);
 976
 977   return EC;
 978 }
 979
 980 std::error_code copy_file(const Twine &From, int ToFD) {
 981   int ReadFD;
 982   if (std::error_code EC = openFileForRead(From, ReadFD, OF_None))
 983     return EC;
 984
 985   std::error_code EC = copy_file_internal(ReadFD, ToFD);
 986
 987   close(ReadFD);
 988
 989   return EC;
 990 }
 991
 992 ErrorOr<MD5::MD5Result> md5_contents(int FD) {
 993   MD5 Hash;
 994
 995   constexpr size_t BufSize = 4096;
 996   std::vector<uint8_t> Buf(BufSize);
 997   int BytesRead = 0;
 998   for (;;) {
 999     BytesRead = read(FD, Buf.data(), BufSize);
1000     if (BytesRead <= 0)
1001       break;
1002     Hash.update(makeArrayRef(Buf.data(), BytesRead));
1003   }
1004
1005   if (BytesRead < 0)
1006     return std::error_code(errno, std::generic_category());
1007   MD5::MD5Result Result;
1008   Hash.final(Result);
1009   return Result;
1010 }
1011
1012 ErrorOr<MD5::MD5Result> md5_contents(const Twine &Path) {
1013   int FD;
1014   if (auto EC = openFileForRead(Path, FD, OF_None))
1015     return EC;
1016
1017   auto Result = md5_contents(FD);
1018   close(FD);
1019   return Result;
1020 }
1021
1022 bool exists(const basic_file_status &status) {
1023   return status_known(status) && status.type() != file_type::file_not_found;
1024 }
1025
1026 bool status_known(const basic_file_status &s) {
1027   return s.type() != file_type::status_error;
1028 }
1029
1030 file_type get_file_type(const Twine &Path, bool Follow) {
1031   file_status st;
1032   if (status(Path, st, Follow))
1033     return file_type::status_error;
1034   return st.type();
1035 }
1036
1037 bool is_directory(const basic_file_status &status) {
1038   return status.type() == file_type::directory_file;
1039 }
1040
1041 std::error_code is_directory(const Twine &path, bool &result) {
1042   file_status st;
1043   if (std::error_code ec = status(path, st))
1044     return ec;
1045   result = is_directory(st);
1046   return std::error_code();
1047 }
1048
1049 bool is_regular_file(const basic_file_status &status) {
1050   return status.type() == file_type::regular_file;
1051 }
1052
1053 std::error_code is_regular_file(const Twine &path, bool &result) {
1054   file_status st;
1055   if (std::error_code ec = status(path, st))
1056     return ec;
1057   result = is_regular_file(st);
1058   return std::error_code();
1059 }
1060
1061 bool is_symlink_file(const basic_file_status &status) {
1062   return status.type() == file_type::symlink_file;
1063 }
1064
1065 std::error_code is_symlink_file(const Twine &path, bool &result) {
1066   file_status st;
1067   if (std::error_code ec = status(path, st, false))
1068     return ec;
1069   result = is_symlink_file(st);
1070   return std::error_code();
1071 }
1072
1073 bool is_other(const basic_file_status &status) {
1074   return exists(status) &&
1075          !is_regular_file(status) &&
1076          !is_directory(status);
1077 }
1078
1079 std::error_code is_other(const Twine &Path, bool &Result) {
1080   file_status FileStatus;
1081   if (std::error_code EC = status(Path, FileStatus))
1082     return EC;
1083   Result = is_other(FileStatus);
1084   return std::error_code();
1085 }
1086
1087 void directory_entry::replace_filename(const Twine &Filename, file_type Type,
1088                                        basic_file_status Status) {
1089   SmallString<128> PathStr = path::parent_path(Path);
1090   path::append(PathStr, Filename);
1091   this->Path = PathStr.str();
1092   this->Type = Type;
1093   this->Status = Status;
1094 }
1095
1096 ErrorOr<perms> getPermissions(const Twine &Path) {
1097   file_status Status;
1098   if (std::error_code EC = status(Path, Status))
1099     return EC;
1100
1101   return Status.permissions();
1102 }
1103
1104 } // end namespace fs
1105 } // end namespace sys
1106 } // end namespace llvm
1107
1108 // Include the truly platform-specific parts.
1109 #if defined(LLVM_ON_UNIX)
1110 #include "Unix/Path.inc"
1111 #endif
1112 #if defined(_WIN32)
1113 #include "Windows/Path.inc"
1114 #endif
1115
1116 namespace llvm {
1117 namespace sys {
1118 namespace fs {
1119 TempFile::TempFile(StringRef Name, int FD) : TmpName(Name), FD(FD) {}
1120 TempFile::TempFile(TempFile &&Other) { *this = std::move(Other); }
1121 TempFile &TempFile::operator=(TempFile &&Other) {
1122   TmpName = std::move(Other.TmpName);
1123   FD = Other.FD;
1124   Other.Done = true;
1125   return *this;
1126 }
1127
1128 TempFile::~TempFile() { assert(Done); }
1129
1130 Error TempFile::discard() {
1131   Done = true;
1132   if (FD != -1 && close(FD) == -1) {
1133     std::error_code EC = std::error_code(errno, std::generic_category());
1134     return errorCodeToError(EC);
1135   }
1136   FD = -1;
1137
1138 #ifdef _WIN32
1139   // On windows closing will remove the file.
1140   TmpName = "";
1141   return Error::success();
1142 #else
1143   // Always try to close and remove.
1144   std::error_code RemoveEC;
1145   if (!TmpName.empty()) {
1146     RemoveEC = fs::remove(TmpName);
1147     sys::DontRemoveFileOnSignal(TmpName);
1148     if (!RemoveEC)
1149       TmpName = "";
1150   }
1151   return errorCodeToError(RemoveEC);
1152 #endif
1153 }
1154
1155 Error TempFile::keep(const Twine &Name) {
1156   assert(!Done);
1157   Done = true;
1158   // Always try to close and rename.
1159 #ifdef _WIN32
1160   // If we can't cancel the delete don't rename.
1161   auto H = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
1162   std::error_code RenameEC = setDeleteDisposition(H, false);
1163   if (!RenameEC) {
1164     RenameEC = rename_fd(FD, Name);
1165     // If rename failed because it's cross-device, copy instead
1166     if (RenameEC ==
1167       std::error_code(ERROR_NOT_SAME_DEVICE, std::system_category())) {
1168       RenameEC = copy_file(TmpName, Name);
1169       setDeleteDisposition(H, true);
1170     }
1171   }
1172
1173   // If we can't rename, discard the temporary file.
1174   if (RenameEC)
1175     setDeleteDisposition(H, true);
1176 #else
1177   std::error_code RenameEC = fs::rename(TmpName, Name);
1178   if (RenameEC) {
1179     // If we can't rename, try to copy to work around cross-device link issues.
1180     RenameEC = sys::fs::copy_file(TmpName, Name);
1181     // If we can't rename or copy, discard the temporary file.
1182     if (RenameEC)
1183       remove(TmpName);
1184   }
1185   sys::DontRemoveFileOnSignal(TmpName);
1186 #endif
1187
1188   if (!RenameEC)
1189     TmpName = "";
1190
1191   if (close(FD) == -1) {
1192     std::error_code EC(errno, std::generic_category());
1193     return errorCodeToError(EC);
1194   }
1195   FD = -1;
1196
1197   return errorCodeToError(RenameEC);
1198 }
1199
1200 Error TempFile::keep() {
1201   assert(!Done);
1202   Done = true;
1203
1204 #ifdef _WIN32
1205   auto H = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
1206   if (std::error_code EC = setDeleteDisposition(H, false))
1207     return errorCodeToError(EC);
1208 #else
1209   sys::DontRemoveFileOnSignal(TmpName);
1210 #endif
1211
1212   TmpName = "";
1213
1214   if (close(FD) == -1) {
1215     std::error_code EC(errno, std::generic_category());
1216     return errorCodeToError(EC);
1217   }
1218   FD = -1;
1219
1220   return Error::success();
1221 }
1222
1223 Expected<TempFile> TempFile::create(const Twine &Model, unsigned Mode) {
1224   int FD;
1225   SmallString<128> ResultPath;
1226   if (std::error_code EC =
1227           createUniqueFile(Model, FD, ResultPath, Mode, OF_Delete))
1228     return errorCodeToError(EC);
1229
1230   TempFile Ret(ResultPath, FD);
1231 #ifndef _WIN32
1232   if (sys::RemoveFileOnSignal(ResultPath)) {
1233     // Make sure we delete the file when RemoveFileOnSignal fails.
1234     consumeError(Ret.discard());
1235     std::error_code EC(errc::operation_not_permitted);
1236     return errorCodeToError(EC);
1237   }
1238 #endif
1239   return std::move(Ret);
1240 }
1241 }
1242
1243 } // end namsspace sys
1244 } // end namespace llvm