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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-exception6//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/ADT/ScopeExit.h"16#include "llvm/ADT/StringExtras.h"17#include "llvm/Config/config.h"18#include "llvm/Config/llvm-config.h"19#include "llvm/Support/Errc.h"20#include "llvm/Support/ErrorHandling.h"21#include "llvm/Support/FileSystem.h"22#include "llvm/Support/Process.h"23#include "llvm/Support/Signals.h"24#include <cctype>25 26#if !defined(_MSC_VER) && !defined(__MINGW32__)27#include <unistd.h>28#else29#include <io.h>30#endif31 32using namespace llvm;33using namespace llvm::support::endian;34 35namespace {36  using llvm::StringRef;37  using llvm::sys::path::is_separator;38  using llvm::sys::path::Style;39 40  inline Style real_style(Style style) {41    if (style != Style::native)42      return style;43    if (is_style_posix(style))44      return Style::posix;45    return LLVM_WINDOWS_PREFER_FORWARD_SLASH ? Style::windows_slash46                                             : Style::windows_backslash;47  }48 49  inline const char *separators(Style style) {50    if (is_style_windows(style))51      return "\\/";52    return "/";53  }54 55  inline char preferred_separator(Style style) {56    if (real_style(style) == Style::windows)57      return '\\';58    return '/';59  }60 61  StringRef find_first_component(StringRef path, Style style) {62    // Look for this first component in the following order.63    // * empty (in this case we return an empty string)64    // * either C: or {//,\\}net.65    // * {/,\}66    // * {file,directory}name67 68    if (path.empty())69      return path;70 71    if (is_style_windows(style)) {72      // C:73      if (path.size() >= 2 &&74          std::isalpha(static_cast<unsigned char>(path[0])) && path[1] == ':')75        return path.substr(0, 2);76    }77 78    // //net79    if ((path.size() > 2) && is_separator(path[0], style) &&80        path[0] == path[1] && !is_separator(path[2], style)) {81      // Find the next directory separator.82      size_t end = path.find_first_of(separators(style), 2);83      return path.substr(0, end);84    }85 86    // {/,\}87    if (is_separator(path[0], style))88      return path.substr(0, 1);89 90    // * {file,directory}name91    size_t end = path.find_first_of(separators(style));92    return path.substr(0, end);93  }94 95  // Returns the first character of the filename in str. For paths ending in96  // '/', it returns the position of the '/'.97  size_t filename_pos(StringRef str, Style style) {98    if (str.size() > 0 && is_separator(str[str.size() - 1], style))99      return str.size() - 1;100 101    size_t pos = str.find_last_of(separators(style), str.size() - 1);102 103    if (is_style_windows(style)) {104      if (pos == StringRef::npos)105        pos = str.find_last_of(':', str.size() - 1);106    }107 108    if (pos == StringRef::npos || (pos == 1 && is_separator(str[0], style)))109      return 0;110 111    return pos + 1;112  }113 114  // Returns the position of the root directory in str. If there is no root115  // directory in str, it returns StringRef::npos.116  size_t root_dir_start(StringRef str, Style style) {117    // case "c:/"118    if (is_style_windows(style)) {119      if (str.size() > 2 && str[1] == ':' && is_separator(str[2], style))120        return 2;121    }122 123    // case "//net"124    if (str.size() > 3 && is_separator(str[0], style) && str[0] == str[1] &&125        !is_separator(str[2], style)) {126      return str.find_first_of(separators(style), 2);127    }128 129    // case "/"130    if (str.size() > 0 && is_separator(str[0], style))131      return 0;132 133    return StringRef::npos;134  }135 136  // Returns the position past the end of the "parent path" of path. The parent137  // path will not end in '/', unless the parent is the root directory. If the138  // path has no parent, 0 is returned.139  size_t parent_path_end(StringRef path, Style style) {140    size_t end_pos = filename_pos(path, style);141 142    bool filename_was_sep =143        path.size() > 0 && is_separator(path[end_pos], style);144 145    // Skip separators until we reach root dir (or the start of the string).146    size_t root_dir_pos = root_dir_start(path, style);147    while (end_pos > 0 &&148           (root_dir_pos == StringRef::npos || end_pos > root_dir_pos) &&149           is_separator(path[end_pos - 1], style))150      --end_pos;151 152    if (end_pos == root_dir_pos && !filename_was_sep) {153      // We've reached the root dir and the input path was *not* ending in a154      // sequence of slashes. Include the root dir in the parent path.155      return root_dir_pos + 1;156    }157 158    // Otherwise, just include before the last slash.159    return end_pos;160  }161} // end unnamed namespace162 163enum FSEntity {164  FS_Dir,165  FS_File,166  FS_Name167};168 169static std::error_code170createUniqueEntity(const Twine &Model, int &ResultFD,171                   SmallVectorImpl<char> &ResultPath, bool MakeAbsolute,172                   FSEntity Type, sys::fs::OpenFlags Flags = sys::fs::OF_None,173                   unsigned Mode = 0) {174 175  // Limit the number of attempts we make, so that we don't infinite loop. E.g.176  // "permission denied" could be for a specific file (so we retry with a177  // different name) or for the whole directory (retry would always fail).178  // Checking which is racy, so we try a number of times, then give up.179  std::error_code EC;180  for (int Retries = 128; Retries > 0; --Retries) {181    sys::fs::createUniquePath(Model, ResultPath, MakeAbsolute);182    // Try to open + create the file.183    switch (Type) {184    case FS_File: {185      EC = sys::fs::openFileForReadWrite(Twine(ResultPath.begin()), ResultFD,186                                         sys::fs::CD_CreateNew, Flags, Mode);187      if (EC) {188        // errc::permission_denied happens on Windows when we try to open a file189        // that has been marked for deletion.190        if (EC == errc::file_exists || EC == errc::permission_denied)191          continue;192        return EC;193      }194 195      return std::error_code();196    }197 198    case FS_Name: {199      EC = sys::fs::access(ResultPath.begin(), sys::fs::AccessMode::Exist);200      if (EC == errc::no_such_file_or_directory)201        return std::error_code();202      if (EC)203        return EC;204      continue;205    }206 207    case FS_Dir: {208      EC = sys::fs::create_directory(ResultPath.begin(), false);209      if (EC) {210        if (EC == errc::file_exists)211          continue;212        return EC;213      }214      return std::error_code();215    }216    }217    llvm_unreachable("Invalid Type");218  }219  return EC;220}221 222namespace llvm {223namespace sys  {224namespace path {225 226const_iterator begin(StringRef path, Style style) {227  const_iterator i;228  i.Path      = path;229  i.Component = find_first_component(path, style);230  i.Position  = 0;231  i.S = style;232  return i;233}234 235const_iterator end(StringRef path) {236  const_iterator i;237  i.Path      = path;238  i.Position  = path.size();239  return i;240}241 242const_iterator &const_iterator::operator++() {243  assert(Position < Path.size() && "Tried to increment past end!");244 245  // Increment Position to past the current component246  Position += Component.size();247 248  // Check for end.249  if (Position == Path.size()) {250    Component = StringRef();251    return *this;252  }253 254  // Both POSIX and Windows treat paths that begin with exactly two separators255  // specially.256  bool was_net = Component.size() > 2 && is_separator(Component[0], S) &&257                 Component[1] == Component[0] && !is_separator(Component[2], S);258 259  // Handle separators.260  if (is_separator(Path[Position], S)) {261    // Root dir.262    if (was_net ||263        // c:/264        (is_style_windows(S) && Component.ends_with(":"))) {265      Component = Path.substr(Position, 1);266      return *this;267    }268 269    // Skip extra separators.270    while (Position != Path.size() && is_separator(Path[Position], S)) {271      ++Position;272    }273 274    // Treat trailing '/' as a '.', unless it is the root dir.275    if (Position == Path.size() && Component != "/") {276      --Position;277      Component = ".";278      return *this;279    }280  }281 282  // Find next component.283  size_t end_pos = Path.find_first_of(separators(S), Position);284  Component = Path.slice(Position, end_pos);285 286  return *this;287}288 289bool const_iterator::operator==(const const_iterator &RHS) const {290  return Path.begin() == RHS.Path.begin() && Position == RHS.Position;291}292 293ptrdiff_t const_iterator::operator-(const const_iterator &RHS) const {294  return Position - RHS.Position;295}296 297reverse_iterator rbegin(StringRef Path, Style style) {298  reverse_iterator I;299  I.Path = Path;300  I.Position = Path.size();301  I.S = style;302  ++I;303  return I;304}305 306reverse_iterator rend(StringRef Path) {307  reverse_iterator I;308  I.Path = Path;309  I.Component = Path.substr(0, 0);310  I.Position = 0;311  return I;312}313 314reverse_iterator &reverse_iterator::operator++() {315  size_t root_dir_pos = root_dir_start(Path, S);316 317  // Skip separators unless it's the root directory.318  size_t end_pos = Position;319  while (end_pos > 0 && (end_pos - 1) != root_dir_pos &&320         is_separator(Path[end_pos - 1], S))321    --end_pos;322 323  // Treat trailing '/' as a '.', unless it is the root dir.324  if (Position == Path.size() && !Path.empty() &&325      is_separator(Path.back(), S) &&326      (root_dir_pos == StringRef::npos || end_pos - 1 > root_dir_pos)) {327    --Position;328    Component = ".";329    return *this;330  }331 332  // Find next separator.333  size_t start_pos = filename_pos(Path.substr(0, end_pos), S);334  Component = Path.slice(start_pos, end_pos);335  Position = start_pos;336  return *this;337}338 339bool reverse_iterator::operator==(const reverse_iterator &RHS) const {340  return Path.begin() == RHS.Path.begin() && Component == RHS.Component &&341         Position == RHS.Position;342}343 344ptrdiff_t reverse_iterator::operator-(const reverse_iterator &RHS) const {345  return Position - RHS.Position;346}347 348StringRef root_path(StringRef path, Style style) {349  const_iterator b = begin(path, style), pos = b, e = end(path);350  if (b != e) {351    bool has_net =352        b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0];353    bool has_drive = is_style_windows(style) && b->ends_with(":");354 355    if (has_net || has_drive) {356      if ((++pos != e) && is_separator((*pos)[0], style)) {357        // {C:/,//net/}, so get the first two components.358        return path.substr(0, b->size() + pos->size());359      }360      // just {C:,//net}, return the first component.361      return *b;362    }363 364    // POSIX style root directory.365    if (is_separator((*b)[0], style)) {366      return *b;367    }368  }369 370  return StringRef();371}372 373StringRef root_name(StringRef path, Style style) {374  const_iterator b = begin(path, style), e = end(path);375  if (b != e) {376    bool has_net =377        b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0];378    bool has_drive = is_style_windows(style) && b->ends_with(":");379 380    if (has_net || has_drive) {381      // just {C:,//net}, return the first component.382      return *b;383    }384  }385 386  // No path or no name.387  return StringRef();388}389 390StringRef root_directory(StringRef path, Style style) {391  const_iterator b = begin(path, style), pos = b, e = end(path);392  if (b != e) {393    bool has_net =394        b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0];395    bool has_drive = is_style_windows(style) && b->ends_with(":");396 397    if ((has_net || has_drive) &&398        // {C:,//net}, skip to the next component.399        (++pos != e) && is_separator((*pos)[0], style)) {400      return *pos;401    }402 403    // POSIX style root directory.404    if (!has_net && is_separator((*b)[0], style)) {405      return *b;406    }407  }408 409  // No path or no root.410  return StringRef();411}412 413StringRef relative_path(StringRef path, Style style) {414  StringRef root = root_path(path, style);415  return path.substr(root.size());416}417 418void append(SmallVectorImpl<char> &path, Style style, const Twine &a,419            const Twine &b, const Twine &c, const Twine &d) {420  SmallString<32> a_storage;421  SmallString<32> b_storage;422  SmallString<32> c_storage;423  SmallString<32> d_storage;424 425  SmallVector<StringRef, 4> components;426  if (!a.isTriviallyEmpty()) components.push_back(a.toStringRef(a_storage));427  if (!b.isTriviallyEmpty()) components.push_back(b.toStringRef(b_storage));428  if (!c.isTriviallyEmpty()) components.push_back(c.toStringRef(c_storage));429  if (!d.isTriviallyEmpty()) components.push_back(d.toStringRef(d_storage));430 431  for (auto &component : components) {432    bool path_has_sep =433        !path.empty() && is_separator(path[path.size() - 1], style);434    if (path_has_sep) {435      // Strip separators from beginning of component.436      size_t loc = component.find_first_not_of(separators(style));437      StringRef c = component.substr(loc);438 439      // Append it.440      path.append(c.begin(), c.end());441      continue;442    }443 444    bool component_has_sep =445        !component.empty() && is_separator(component[0], style);446    if (!component_has_sep &&447        !(path.empty() || has_root_name(component, style))) {448      // Add a separator.449      path.push_back(preferred_separator(style));450    }451 452    path.append(component.begin(), component.end());453  }454}455 456void append(SmallVectorImpl<char> &path, const Twine &a, const Twine &b,457            const Twine &c, const Twine &d) {458  append(path, Style::native, a, b, c, d);459}460 461void append(SmallVectorImpl<char> &path, const_iterator begin,462            const_iterator end, Style style) {463  for (; begin != end; ++begin)464    path::append(path, style, *begin);465}466 467StringRef parent_path(StringRef path, Style style) {468  size_t end_pos = parent_path_end(path, style);469  if (end_pos == StringRef::npos)470    return StringRef();471  return path.substr(0, end_pos);472}473 474void 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.truncate(end_pos);478}479 480void 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.truncate(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 499static bool starts_with(StringRef Path, StringRef Prefix,500                        Style style = Style::native) {501  // Windows prefix matching : case and separator insensitive502  if (is_style_windows(style)) {503    if (Path.size() < Prefix.size())504      return false;505    for (size_t I = 0, E = Prefix.size(); I != E; ++I) {506      bool SepPath = is_separator(Path[I], style);507      bool SepPrefix = is_separator(Prefix[I], style);508      if (SepPath != SepPrefix)509        return false;510      if (!SepPath && toLower(Path[I]) != toLower(Prefix[I]))511        return false;512    }513    return true;514  }515  return Path.starts_with(Prefix);516}517 518bool replace_path_prefix(SmallVectorImpl<char> &Path, StringRef OldPrefix,519                         StringRef NewPrefix, Style style) {520  if (OldPrefix.empty() && NewPrefix.empty())521    return false;522 523  StringRef OrigPath(Path.begin(), Path.size());524  if (!starts_with(OrigPath, OldPrefix, style))525    return false;526 527  // If prefixes have the same size we can simply copy the new one over.528  if (OldPrefix.size() == NewPrefix.size()) {529    llvm::copy(NewPrefix, Path.begin());530    return true;531  }532 533  StringRef RelPath = OrigPath.substr(OldPrefix.size());534  SmallString<256> NewPath;535  (Twine(NewPrefix) + RelPath).toVector(NewPath);536  Path.swap(NewPath);537  return true;538}539 540void native(const Twine &path, SmallVectorImpl<char> &result, Style style) {541  assert((!path.isSingleStringRef() ||542          path.getSingleStringRef().data() != result.data()) &&543         "path and result are not allowed to overlap!");544  // Clear result.545  result.clear();546  path.toVector(result);547  native(result, style);548}549 550void native(SmallVectorImpl<char> &Path, Style style) {551  if (Path.empty())552    return;553  if (is_style_windows(style)) {554    for (char &Ch : Path)555      if (is_separator(Ch, style))556        Ch = preferred_separator(style);557    if (Path[0] == '~' && (Path.size() == 1 || is_separator(Path[1], style))) {558      SmallString<128> PathHome;559      home_directory(PathHome);560      PathHome.append(Path.begin() + 1, Path.end());561      Path = PathHome;562    }563  } else {564    llvm::replace(Path, '\\', '/');565  }566}567 568std::string convert_to_slash(StringRef path, Style style) {569  if (is_style_posix(style))570    return std::string(path);571 572  std::string s = path.str();573  llvm::replace(s, '\\', '/');574  return s;575}576 577StringRef filename(StringRef path, Style style) { return *rbegin(path, style); }578 579StringRef stem(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 fname;584  if ((fname.size() == 1 && fname == ".") ||585      (fname.size() == 2 && fname == ".."))586    return fname;587  return fname.substr(0, pos);588}589 590StringRef extension(StringRef path, Style style) {591  StringRef fname = filename(path, style);592  size_t pos = fname.find_last_of('.');593  if (pos == StringRef::npos)594    return StringRef();595  if ((fname.size() == 1 && fname == ".") ||596      (fname.size() == 2 && fname == ".."))597    return StringRef();598  return fname.substr(pos);599}600 601bool is_separator(char value, Style style) {602  if (value == '/')603    return true;604  if (is_style_windows(style))605    return value == '\\';606  return false;607}608 609StringRef get_separator(Style style) {610  if (real_style(style) == Style::windows)611    return "\\";612  return "/";613}614 615bool has_root_name(const Twine &path, Style style) {616  SmallString<128> path_storage;617  StringRef p = path.toStringRef(path_storage);618 619  return !root_name(p, style).empty();620}621 622bool has_root_directory(const Twine &path, Style style) {623  SmallString<128> path_storage;624  StringRef p = path.toStringRef(path_storage);625 626  return !root_directory(p, style).empty();627}628 629bool has_root_path(const Twine &path, Style style) {630  SmallString<128> path_storage;631  StringRef p = path.toStringRef(path_storage);632 633  return !root_path(p, style).empty();634}635 636bool has_relative_path(const Twine &path, Style style) {637  SmallString<128> path_storage;638  StringRef p = path.toStringRef(path_storage);639 640  return !relative_path(p, style).empty();641}642 643bool has_filename(const Twine &path, Style style) {644  SmallString<128> path_storage;645  StringRef p = path.toStringRef(path_storage);646 647  return !filename(p, style).empty();648}649 650bool has_parent_path(const Twine &path, Style style) {651  SmallString<128> path_storage;652  StringRef p = path.toStringRef(path_storage);653 654  return !parent_path(p, style).empty();655}656 657bool has_stem(const Twine &path, Style style) {658  SmallString<128> path_storage;659  StringRef p = path.toStringRef(path_storage);660 661  return !stem(p, style).empty();662}663 664bool has_extension(const Twine &path, Style style) {665  SmallString<128> path_storage;666  StringRef p = path.toStringRef(path_storage);667 668  return !extension(p, style).empty();669}670 671bool is_absolute(const Twine &path, Style style) {672  SmallString<128> path_storage;673  StringRef p = path.toStringRef(path_storage);674 675  bool rootDir = has_root_directory(p, style);676  bool rootName = is_style_posix(style) || has_root_name(p, style);677 678  return rootDir && rootName;679}680 681bool is_absolute_gnu(const Twine &path, Style style) {682  SmallString<128> path_storage;683  StringRef p = path.toStringRef(path_storage);684 685  // Handle '/' which is absolute for both Windows and POSIX systems.686  // Handle '\\' on Windows.687  if (!p.empty() && is_separator(p.front(), style))688    return true;689 690  if (is_style_windows(style)) {691    // Handle drive letter pattern (a character followed by ':') on Windows.692    if (p.size() >= 2 && (p[0] && p[1] == ':'))693      return true;694  }695 696  return false;697}698 699bool is_relative(const Twine &path, Style style) {700  return !is_absolute(path, style);701}702 703void make_absolute(const Twine &current_directory,704                   SmallVectorImpl<char> &path) {705  StringRef p(path.data(), path.size());706 707  bool rootDirectory = has_root_directory(p);708  bool rootName = has_root_name(p);709 710  // Already absolute.711  if ((rootName || is_style_posix(Style::native)) && rootDirectory)712    return;713 714  // All the following conditions will need the current directory.715  SmallString<128> current_dir;716  current_directory.toVector(current_dir);717 718  // Relative path. Prepend the current directory.719  if (!rootName && !rootDirectory) {720    // Append path to the current directory.721    append(current_dir, p);722    // Set path to the result.723    path.swap(current_dir);724    return;725  }726 727  if (!rootName && rootDirectory) {728    StringRef cdrn = root_name(current_dir);729    SmallString<128> curDirRootName(cdrn.begin(), cdrn.end());730    append(curDirRootName, p);731    // Set path to the result.732    path.swap(curDirRootName);733    return;734  }735 736  if (rootName && !rootDirectory) {737    StringRef pRootName = root_name(p);738    StringRef bRootDirectory = root_directory(current_dir);739    StringRef bRelativePath = relative_path(current_dir);740    StringRef pRelativePath = relative_path(p);741 742    SmallString<128> res;743    append(res, pRootName, bRootDirectory, bRelativePath, pRelativePath);744    path.swap(res);745    return;746  }747 748  llvm_unreachable("All rootName and rootDirectory combinations should have "749                   "occurred above!");750}751 752StringRef remove_leading_dotslash(StringRef Path, Style style) {753  // Remove leading "./" (or ".//" or "././" etc.)754  while (Path.size() > 2 && Path[0] == '.' && is_separator(Path[1], style)) {755    Path = Path.substr(2);756    while (Path.size() > 0 && is_separator(Path[0], style))757      Path = Path.substr(1);758  }759  return Path;760}761 762// Remove path traversal components ("." and "..") when possible, and763// canonicalize slashes.764bool remove_dots(SmallVectorImpl<char> &the_path, bool remove_dot_dot,765                 Style style) {766  style = real_style(style);767  StringRef remaining(the_path.data(), the_path.size());768  bool needs_change = false;769  SmallVector<StringRef, 16> components;770 771  // Consume the root path, if present.772  StringRef root = path::root_path(remaining, style);773  bool absolute = !root.empty();774  if (absolute)775    remaining = remaining.drop_front(root.size());776 777  // Loop over path components manually. This makes it easier to detect778  // non-preferred slashes and double separators that must be canonicalized.779  while (!remaining.empty()) {780    size_t next_slash = remaining.find_first_of(separators(style));781    if (next_slash == StringRef::npos)782      next_slash = remaining.size();783    StringRef component = remaining.take_front(next_slash);784    remaining = remaining.drop_front(next_slash);785 786    // Eat the slash, and check if it is the preferred separator.787    if (!remaining.empty()) {788      needs_change |= remaining.front() != preferred_separator(style);789      remaining = remaining.drop_front();790      // The path needs to be rewritten if it has a trailing slash.791      // FIXME: This is emergent behavior that could be removed.792      needs_change |= remaining.empty();793    }794 795    // Check for path traversal components or double separators.796    if (component.empty() || component == ".") {797      needs_change = true;798    } else if (remove_dot_dot && component == "..") {799      needs_change = true;800      // Do not allow ".." to remove the root component. If this is the801      // beginning of a relative path, keep the ".." component.802      if (!components.empty() && components.back() != "..") {803        components.pop_back();804      } else if (!absolute) {805        components.push_back(component);806      }807    } else {808      components.push_back(component);809    }810  }811 812  SmallString<256> buffer = root;813  // "root" could be "/", which may need to be translated into "\".814  make_preferred(buffer, style);815  needs_change |= root != buffer;816 817  // Avoid rewriting the path unless we have to.818  if (!needs_change)819    return false;820 821  if (!components.empty()) {822    buffer += components[0];823    for (StringRef C : ArrayRef(components).drop_front()) {824      buffer += preferred_separator(style);825      buffer += C;826    }827  }828  the_path.swap(buffer);829  return true;830}831 832} // end namespace path833 834namespace fs {835 836std::error_code getUniqueID(const Twine Path, UniqueID &Result) {837  file_status Status;838  std::error_code EC = status(Path, Status);839  if (EC)840    return EC;841  Result = Status.getUniqueID();842  return std::error_code();843}844 845void createUniquePath(const Twine &Model, SmallVectorImpl<char> &ResultPath,846                      bool MakeAbsolute) {847  SmallString<128> ModelStorage;848  Model.toVector(ModelStorage);849 850  if (MakeAbsolute) {851    // Make model absolute by prepending a temp directory if it's not already.852    if (!sys::path::is_absolute(Twine(ModelStorage))) {853      SmallString<128> TDir;854      sys::path::system_temp_directory(true, TDir);855      sys::path::append(TDir, Twine(ModelStorage));856      ModelStorage.swap(TDir);857    }858  }859 860  ResultPath = ModelStorage;861  ResultPath.push_back(0);862  ResultPath.pop_back();863 864  // Replace '%' with random chars.865  for (unsigned i = 0, e = ModelStorage.size(); i != e; ++i) {866    if (ModelStorage[i] == '%')867      ResultPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];868  }869}870 871std::error_code createUniqueFile(const Twine &Model, int &ResultFd,872                                 SmallVectorImpl<char> &ResultPath,873                                 OpenFlags Flags, unsigned Mode) {874  return createUniqueEntity(Model, ResultFd, ResultPath, false, FS_File, Flags,875                            Mode);876}877 878std::error_code createUniqueFile(const Twine &Model,879                                 SmallVectorImpl<char> &ResultPath,880                                 unsigned Mode) {881  int FD;882  auto EC = createUniqueFile(Model, FD, ResultPath, OF_None, Mode);883  if (EC)884    return EC;885  // FD is only needed to avoid race conditions. Close it right away.886  close(FD);887  return EC;888}889 890static std::error_code891createTemporaryFile(const Twine &Model, int &ResultFD,892                    llvm::SmallVectorImpl<char> &ResultPath, FSEntity Type,893                    sys::fs::OpenFlags Flags = sys::fs::OF_None) {894  SmallString<128> Storage;895  StringRef P = Model.toNullTerminatedStringRef(Storage);896  assert(P.find_first_of(separators(Style::native)) == StringRef::npos &&897         "Model must be a simple filename.");898  // Use P.begin() so that createUniqueEntity doesn't need to recreate Storage.899  return createUniqueEntity(P.begin(), ResultFD, ResultPath, true, Type, Flags,900                            all_read | all_write);901}902 903static std::error_code904createTemporaryFile(const Twine &Prefix, StringRef Suffix, int &ResultFD,905                    llvm::SmallVectorImpl<char> &ResultPath, FSEntity Type,906                    sys::fs::OpenFlags Flags = sys::fs::OF_None) {907  const char *Middle = Suffix.empty() ? "-%%%%%%" : "-%%%%%%.";908  return createTemporaryFile(Prefix + Middle + Suffix, ResultFD, ResultPath,909                             Type, Flags);910}911 912std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,913                                    int &ResultFD,914                                    SmallVectorImpl<char> &ResultPath,915                                    sys::fs::OpenFlags Flags) {916  return createTemporaryFile(Prefix, Suffix, ResultFD, ResultPath, FS_File,917                             Flags);918}919 920std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,921                                    SmallVectorImpl<char> &ResultPath,922                                    sys::fs::OpenFlags Flags) {923  int FD;924  auto EC = createTemporaryFile(Prefix, Suffix, FD, ResultPath, Flags);925  if (EC)926    return EC;927  // FD is only needed to avoid race conditions. Close it right away.928  close(FD);929  return EC;930}931 932// This is a mkdtemp with a different pattern. We use createUniqueEntity mostly933// for consistency. We should try using mkdtemp.934std::error_code createUniqueDirectory(const Twine &Prefix,935                                      SmallVectorImpl<char> &ResultPath) {936  int Dummy;937  return createUniqueEntity(Prefix + "-%%%%%%", Dummy, ResultPath, true,938                            FS_Dir);939}940 941std::error_code942getPotentiallyUniqueFileName(const Twine &Model,943                             SmallVectorImpl<char> &ResultPath) {944  int Dummy;945  return createUniqueEntity(Model, Dummy, ResultPath, false, FS_Name);946}947 948std::error_code949getPotentiallyUniqueTempFileName(const Twine &Prefix, StringRef Suffix,950                                 SmallVectorImpl<char> &ResultPath) {951  int Dummy;952  return createTemporaryFile(Prefix, Suffix, Dummy, ResultPath, FS_Name);953}954 955std::error_code make_absolute(SmallVectorImpl<char> &path) {956  if (path::is_absolute(path))957    return {};958 959  SmallString<128> current_dir;960  if (std::error_code ec = current_path(current_dir))961    return ec;962 963  path::make_absolute(current_dir, path);964  return {};965}966 967std::error_code create_directories(const Twine &Path, bool IgnoreExisting,968                                   perms Perms) {969  SmallString<128> PathStorage;970  StringRef P = Path.toStringRef(PathStorage);971 972  // Be optimistic and try to create the directory973  std::error_code EC = create_directory(P, IgnoreExisting, Perms);974  // If we succeeded, or had any error other than the parent not existing, just975  // return it.976  if (EC != errc::no_such_file_or_directory)977    return EC;978 979  // We failed because of a no_such_file_or_directory, try to create the980  // parent.981  StringRef Parent = path::parent_path(P);982  if (Parent.empty())983    return EC;984 985  if ((EC = create_directories(Parent, IgnoreExisting, Perms)))986      return EC;987 988  return create_directory(P, IgnoreExisting, Perms);989}990 991static std::error_code copy_file_internal(int ReadFD, int WriteFD) {992  const size_t BufSize = 4096;993  char *Buf = new char[BufSize];994  int BytesRead = 0, BytesWritten = 0;995  for (;;) {996    BytesRead = read(ReadFD, Buf, BufSize);997    if (BytesRead <= 0)998      break;999    while (BytesRead) {1000      BytesWritten = write(WriteFD, Buf, BytesRead);1001      if (BytesWritten < 0)1002        break;1003      BytesRead -= BytesWritten;1004    }1005    if (BytesWritten < 0)1006      break;1007  }1008  delete[] Buf;1009 1010  if (BytesRead < 0 || BytesWritten < 0)1011    return errnoAsErrorCode();1012  return std::error_code();1013}1014 1015#ifndef __APPLE__1016std::error_code copy_file(const Twine &From, const Twine &To) {1017  int ReadFD, WriteFD;1018  if (std::error_code EC = openFileForRead(From, ReadFD, OF_None))1019    return EC;1020  if (std::error_code EC =1021          openFileForWrite(To, WriteFD, CD_CreateAlways, OF_None)) {1022    close(ReadFD);1023    return EC;1024  }1025 1026  std::error_code EC = copy_file_internal(ReadFD, WriteFD);1027 1028  close(ReadFD);1029  close(WriteFD);1030 1031  return EC;1032}1033#endif1034 1035std::error_code copy_file(const Twine &From, int ToFD) {1036  int ReadFD;1037  if (std::error_code EC = openFileForRead(From, ReadFD, OF_None))1038    return EC;1039 1040  std::error_code EC = copy_file_internal(ReadFD, ToFD);1041 1042  close(ReadFD);1043 1044  return EC;1045}1046 1047ErrorOr<MD5::MD5Result> md5_contents(int FD) {1048  MD5 Hash;1049 1050  constexpr size_t BufSize = 4096;1051  std::vector<uint8_t> Buf(BufSize);1052  int BytesRead = 0;1053  for (;;) {1054    BytesRead = read(FD, Buf.data(), BufSize);1055    if (BytesRead <= 0)1056      break;1057    Hash.update(ArrayRef(Buf.data(), BytesRead));1058  }1059 1060  if (BytesRead < 0)1061    return errnoAsErrorCode();1062  MD5::MD5Result Result;1063  Hash.final(Result);1064  return Result;1065}1066 1067ErrorOr<MD5::MD5Result> md5_contents(const Twine &Path) {1068  int FD;1069  if (auto EC = openFileForRead(Path, FD, OF_None))1070    return EC;1071 1072  auto Result = md5_contents(FD);1073  close(FD);1074  return Result;1075}1076 1077bool exists(const basic_file_status &status) {1078  return status_known(status) && status.type() != file_type::file_not_found;1079}1080 1081bool status_known(const basic_file_status &s) {1082  return s.type() != file_type::status_error;1083}1084 1085file_type get_file_type(const Twine &Path, bool Follow) {1086  file_status st;1087  if (status(Path, st, Follow))1088    return file_type::status_error;1089  return st.type();1090}1091 1092bool is_directory(const basic_file_status &status) {1093  return status.type() == file_type::directory_file;1094}1095 1096std::error_code is_directory(const Twine &path, bool &result) {1097  file_status st;1098  if (std::error_code ec = status(path, st))1099    return ec;1100  result = is_directory(st);1101  return std::error_code();1102}1103 1104bool is_regular_file(const basic_file_status &status) {1105  return status.type() == file_type::regular_file;1106}1107 1108std::error_code is_regular_file(const Twine &path, bool &result) {1109  file_status st;1110  if (std::error_code ec = status(path, st))1111    return ec;1112  result = is_regular_file(st);1113  return std::error_code();1114}1115 1116bool is_symlink_file(const basic_file_status &status) {1117  return status.type() == file_type::symlink_file;1118}1119 1120std::error_code is_symlink_file(const Twine &path, bool &result) {1121  file_status st;1122  if (std::error_code ec = status(path, st, false))1123    return ec;1124  result = is_symlink_file(st);1125  return std::error_code();1126}1127 1128bool is_other(const basic_file_status &status) {1129  return exists(status) &&1130         !is_regular_file(status) &&1131         !is_directory(status);1132}1133 1134std::error_code is_other(const Twine &Path, bool &Result) {1135  file_status FileStatus;1136  if (std::error_code EC = status(Path, FileStatus))1137    return EC;1138  Result = is_other(FileStatus);1139  return std::error_code();1140}1141 1142void directory_entry::replace_filename(const Twine &Filename, file_type Type,1143                                       basic_file_status Status) {1144  SmallString<128> PathStr = path::parent_path(Path);1145  path::append(PathStr, Filename);1146  this->Path = std::string(PathStr);1147  this->Type = Type;1148  this->Status = Status;1149}1150 1151ErrorOr<perms> getPermissions(const Twine &Path) {1152  file_status Status;1153  if (std::error_code EC = status(Path, Status))1154    return EC;1155 1156  return Status.permissions();1157}1158 1159size_t mapped_file_region::size() const {1160  assert(Mapping && "Mapping failed but used anyway!");1161  return Size;1162}1163 1164char *mapped_file_region::data() const {1165  assert(Mapping && "Mapping failed but used anyway!");1166  return reinterpret_cast<char *>(Mapping);1167}1168 1169const char *mapped_file_region::const_data() const {1170  assert(Mapping && "Mapping failed but used anyway!");1171  return reinterpret_cast<const char *>(Mapping);1172}1173 1174Error readNativeFileToEOF(file_t FileHandle, SmallVectorImpl<char> &Buffer,1175                          ssize_t ChunkSize) {1176  // Install a handler to truncate the buffer to the correct size on exit.1177  size_t Size = Buffer.size();1178  auto TruncateOnExit = make_scope_exit([&]() { Buffer.truncate(Size); });1179 1180  // Read into Buffer until we hit EOF.1181  for (;;) {1182    Buffer.resize_for_overwrite(Size + ChunkSize);1183    Expected<size_t> ReadBytes = readNativeFile(1184        FileHandle, MutableArrayRef(Buffer.begin() + Size, ChunkSize));1185    if (!ReadBytes)1186      return ReadBytes.takeError();1187    if (*ReadBytes == 0)1188      return Error::success();1189    Size += *ReadBytes;1190  }1191}1192 1193} // end namespace fs1194} // end namespace sys1195} // end namespace llvm1196 1197// Include the truly platform-specific parts.1198#if defined(LLVM_ON_UNIX)1199#include "Unix/Path.inc"1200#endif1201#if defined(_WIN32)1202#include "Windows/Path.inc"1203#endif1204 1205namespace llvm {1206namespace sys {1207namespace fs {1208 1209TempFile::TempFile(StringRef Name, int FD)1210    : TmpName(std::string(Name)), FD(FD) {}1211TempFile::TempFile(TempFile &&Other) { *this = std::move(Other); }1212TempFile &TempFile::operator=(TempFile &&Other) {1213  TmpName = std::move(Other.TmpName);1214  FD = Other.FD;1215  Other.Done = true;1216  Other.FD = -1;1217#ifdef _WIN321218  RemoveOnClose = Other.RemoveOnClose;1219  Other.RemoveOnClose = false;1220#endif1221  return *this;1222}1223 1224TempFile::~TempFile() { assert(Done); }1225 1226Error TempFile::discard() {1227  Done = true;1228  if (FD != -1 && close(FD) == -1) {1229    std::error_code EC = errnoAsErrorCode();1230    return errorCodeToError(EC);1231  }1232  FD = -1;1233 1234#ifdef _WIN321235  // On Windows, closing will remove the file, if we set the delete1236  // disposition. If not, remove it manually.1237  bool Remove = RemoveOnClose;1238#else1239  // Always try to remove the file.1240  bool Remove = true;1241#endif1242  std::error_code RemoveEC;1243  if (Remove && !TmpName.empty()) {1244    RemoveEC = fs::remove(TmpName);1245    sys::DontRemoveFileOnSignal(TmpName);1246    if (!RemoveEC)1247      TmpName = "";1248  } else {1249    TmpName = "";1250  }1251  return errorCodeToError(RemoveEC);1252}1253 1254Error TempFile::keep(const Twine &Name) {1255  assert(!Done);1256  Done = true;1257  // Always try to close and rename.1258#ifdef _WIN321259  // If we can't cancel the delete don't rename.1260  auto H = reinterpret_cast<HANDLE>(_get_osfhandle(FD));1261  std::error_code RenameEC =1262      RemoveOnClose ? std::error_code() : setDeleteDisposition(H, false);1263  bool ShouldDelete = false;1264  if (!RenameEC) {1265    RenameEC = rename_handle(H, Name);1266    // If rename failed because it's cross-device, copy instead1267    if (RenameEC ==1268      std::error_code(ERROR_NOT_SAME_DEVICE, std::system_category())) {1269      RenameEC = copy_file(TmpName, Name);1270      ShouldDelete = true;1271    }1272  }1273 1274  // If we can't rename or copy, discard the temporary file.1275  if (RenameEC)1276    ShouldDelete = true;1277  if (ShouldDelete) {1278    if (!RemoveOnClose)1279      setDeleteDisposition(H, true);1280    else1281      remove(TmpName);1282  }1283#else1284  std::error_code RenameEC = fs::rename(TmpName, Name);1285  if (RenameEC) {1286    // If we can't rename, try to copy to work around cross-device link issues.1287    RenameEC = sys::fs::copy_file(TmpName, Name);1288    // If we can't rename or copy, discard the temporary file.1289    if (RenameEC)1290      remove(TmpName);1291  }1292#endif1293  sys::DontRemoveFileOnSignal(TmpName);1294 1295  if (!RenameEC)1296    TmpName = "";1297 1298  if (close(FD) == -1)1299    return errorCodeToError(errnoAsErrorCode());1300  FD = -1;1301 1302  return errorCodeToError(RenameEC);1303}1304 1305Error TempFile::keep() {1306  assert(!Done);1307  Done = true;1308 1309#ifdef _WIN321310  auto H = reinterpret_cast<HANDLE>(_get_osfhandle(FD));1311  if (std::error_code EC = setDeleteDisposition(H, false))1312    return errorCodeToError(EC);1313#endif1314  sys::DontRemoveFileOnSignal(TmpName);1315 1316  TmpName = "";1317 1318  if (close(FD) == -1)1319    return errorCodeToError(errnoAsErrorCode());1320  FD = -1;1321 1322  return Error::success();1323}1324 1325Expected<TempFile> TempFile::create(const Twine &Model, unsigned Mode,1326                                    OpenFlags ExtraFlags) {1327  int FD;1328  SmallString<128> ResultPath;1329  if (std::error_code EC =1330          createUniqueFile(Model, FD, ResultPath, OF_Delete | ExtraFlags, Mode))1331    return errorCodeToError(EC);1332 1333  TempFile Ret(ResultPath, FD);1334#ifdef _WIN321335  auto H = reinterpret_cast<HANDLE>(_get_osfhandle(FD));1336  bool SetSignalHandler = false;1337  if (std::error_code EC = setDeleteDisposition(H, true)) {1338    Ret.RemoveOnClose = true;1339    SetSignalHandler = true;1340  }1341#else1342  bool SetSignalHandler = true;1343#endif1344  if (SetSignalHandler && sys::RemoveFileOnSignal(ResultPath)) {1345    // Make sure we delete the file when RemoveFileOnSignal fails.1346    consumeError(Ret.discard());1347    std::error_code EC(errc::operation_not_permitted);1348    return errorCodeToError(EC);1349  }1350  return std::move(Ret);1351}1352} // namespace fs1353 1354} // namespace sys1355} // namespace llvm1356