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Diffstat (limited to 'contrib/llvm/lib/Support/Path.cpp')
| -rw-r--r-- | contrib/llvm/lib/Support/Path.cpp | 1069 | 
1 files changed, 1069 insertions, 0 deletions
| diff --git a/contrib/llvm/lib/Support/Path.cpp b/contrib/llvm/lib/Support/Path.cpp new file mode 100644 index 000000000000..e58f856ca244 --- /dev/null +++ b/contrib/llvm/lib/Support/Path.cpp @@ -0,0 +1,1069 @@ +//===-- Path.cpp - Implement OS Path Concept ------------------------------===// +// +//                     The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +//  This file implements the operating system Path API. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Support/Path.h" +#include "llvm/ADT/ArrayRef.h" +#include "llvm/BinaryFormat/COFF.h" +#include "llvm/BinaryFormat/MachO.h" +#include "llvm/Support/Endian.h" +#include "llvm/Support/Errc.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/FileSystem.h" +#include "llvm/Support/Process.h" +#include <cctype> +#include <cstring> + +#if !defined(_MSC_VER) && !defined(__MINGW32__) +#include <unistd.h> +#else +#include <io.h> +#endif + +using namespace llvm; +using namespace llvm::support::endian; + +namespace { +  using llvm::StringRef; +  using llvm::sys::path::is_separator; +  using llvm::sys::path::Style; + +  inline Style real_style(Style style) { +#ifdef LLVM_ON_WIN32 +    return (style == Style::posix) ? Style::posix : Style::windows; +#else +    return (style == Style::windows) ? Style::windows : Style::posix; +#endif +  } + +  inline const char *separators(Style style) { +    if (real_style(style) == Style::windows) +      return "\\/"; +    return "/"; +  } + +  inline char preferred_separator(Style style) { +    if (real_style(style) == Style::windows) +      return '\\'; +    return '/'; +  } + +  StringRef find_first_component(StringRef path, Style style) { +    // Look for this first component in the following order. +    // * empty (in this case we return an empty string) +    // * either C: or {//,\\}net. +    // * {/,\} +    // * {file,directory}name + +    if (path.empty()) +      return path; + +    if (real_style(style) == Style::windows) { +      // C: +      if (path.size() >= 2 && +          std::isalpha(static_cast<unsigned char>(path[0])) && path[1] == ':') +        return path.substr(0, 2); +    } + +    // //net +    if ((path.size() > 2) && is_separator(path[0], style) && +        path[0] == path[1] && !is_separator(path[2], style)) { +      // Find the next directory separator. +      size_t end = path.find_first_of(separators(style), 2); +      return path.substr(0, end); +    } + +    // {/,\} +    if (is_separator(path[0], style)) +      return path.substr(0, 1); + +    // * {file,directory}name +    size_t end = path.find_first_of(separators(style)); +    return path.substr(0, end); +  } + +  size_t filename_pos(StringRef str, Style style) { +    if (str.size() == 2 && is_separator(str[0], style) && str[0] == str[1]) +      return 0; + +    if (str.size() > 0 && is_separator(str[str.size() - 1], style)) +      return str.size() - 1; + +    size_t pos = str.find_last_of(separators(style), str.size() - 1); + +    if (real_style(style) == Style::windows) { +      if (pos == StringRef::npos) +        pos = str.find_last_of(':', str.size() - 2); +    } + +    if (pos == StringRef::npos || (pos == 1 && is_separator(str[0], style))) +      return 0; + +    return pos + 1; +  } + +  size_t root_dir_start(StringRef str, Style style) { +    // case "c:/" +    if (real_style(style) == Style::windows) { +      if (str.size() > 2 && str[1] == ':' && is_separator(str[2], style)) +        return 2; +    } + +    // case "//" +    if (str.size() == 2 && is_separator(str[0], style) && str[0] == str[1]) +      return StringRef::npos; + +    // case "//net" +    if (str.size() > 3 && is_separator(str[0], style) && str[0] == str[1] && +        !is_separator(str[2], style)) { +      return str.find_first_of(separators(style), 2); +    } + +    // case "/" +    if (str.size() > 0 && is_separator(str[0], style)) +      return 0; + +    return StringRef::npos; +  } + +  size_t parent_path_end(StringRef path, Style style) { +    size_t end_pos = filename_pos(path, style); + +    bool filename_was_sep = +        path.size() > 0 && is_separator(path[end_pos], style); + +    // Skip separators except for root dir. +    size_t root_dir_pos = root_dir_start(path.substr(0, end_pos), style); + +    while (end_pos > 0 && (end_pos - 1) != root_dir_pos && +           is_separator(path[end_pos - 1], style)) +      --end_pos; + +    if (end_pos == 1 && root_dir_pos == 0 && filename_was_sep) +      return StringRef::npos; + +    return end_pos; +  } +} // end unnamed namespace + +enum FSEntity { +  FS_Dir, +  FS_File, +  FS_Name +}; + +static std::error_code createUniqueEntity(const Twine &Model, int &ResultFD, +                                          SmallVectorImpl<char> &ResultPath, +                                          bool MakeAbsolute, unsigned Mode, +                                          FSEntity Type) { +  SmallString<128> ModelStorage; +  Model.toVector(ModelStorage); + +  if (MakeAbsolute) { +    // Make model absolute by prepending a temp directory if it's not already. +    if (!sys::path::is_absolute(Twine(ModelStorage))) { +      SmallString<128> TDir; +      sys::path::system_temp_directory(true, TDir); +      sys::path::append(TDir, Twine(ModelStorage)); +      ModelStorage.swap(TDir); +    } +  } + +  // From here on, DO NOT modify model. It may be needed if the randomly chosen +  // path already exists. +  ResultPath = ModelStorage; +  // Null terminate. +  ResultPath.push_back(0); +  ResultPath.pop_back(); + +retry_random_path: +  // Replace '%' with random chars. +  for (unsigned i = 0, e = ModelStorage.size(); i != e; ++i) { +    if (ModelStorage[i] == '%') +      ResultPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15]; +  } + +  // Try to open + create the file. +  switch (Type) { +  case FS_File: { +    if (std::error_code EC = +            sys::fs::openFileForWrite(Twine(ResultPath.begin()), ResultFD, +                                      sys::fs::F_RW | sys::fs::F_Excl, Mode)) { +      if (EC == errc::file_exists) +        goto retry_random_path; +      return EC; +    } + +    return std::error_code(); +  } + +  case FS_Name: { +    std::error_code EC = +        sys::fs::access(ResultPath.begin(), sys::fs::AccessMode::Exist); +    if (EC == errc::no_such_file_or_directory) +      return std::error_code(); +    if (EC) +      return EC; +    goto retry_random_path; +  } + +  case FS_Dir: { +    if (std::error_code EC = +            sys::fs::create_directory(ResultPath.begin(), false)) { +      if (EC == errc::file_exists) +        goto retry_random_path; +      return EC; +    } +    return std::error_code(); +  } +  } +  llvm_unreachable("Invalid Type"); +} + +namespace llvm { +namespace sys  { +namespace path { + +const_iterator begin(StringRef path, Style style) { +  const_iterator i; +  i.Path      = path; +  i.Component = find_first_component(path, style); +  i.Position  = 0; +  i.S = style; +  return i; +} + +const_iterator end(StringRef path) { +  const_iterator i; +  i.Path      = path; +  i.Position  = path.size(); +  return i; +} + +const_iterator &const_iterator::operator++() { +  assert(Position < Path.size() && "Tried to increment past end!"); + +  // Increment Position to past the current component +  Position += Component.size(); + +  // Check for end. +  if (Position == Path.size()) { +    Component = StringRef(); +    return *this; +  } + +  // Both POSIX and Windows treat paths that begin with exactly two separators +  // specially. +  bool was_net = Component.size() > 2 && is_separator(Component[0], S) && +                 Component[1] == Component[0] && !is_separator(Component[2], S); + +  // Handle separators. +  if (is_separator(Path[Position], S)) { +    // Root dir. +    if (was_net || +        // c:/ +        (real_style(S) == Style::windows && Component.endswith(":"))) { +      Component = Path.substr(Position, 1); +      return *this; +    } + +    // Skip extra separators. +    while (Position != Path.size() && is_separator(Path[Position], S)) { +      ++Position; +    } + +    // Treat trailing '/' as a '.'. +    if (Position == Path.size()) { +      --Position; +      Component = "."; +      return *this; +    } +  } + +  // Find next component. +  size_t end_pos = Path.find_first_of(separators(S), Position); +  Component = Path.slice(Position, end_pos); + +  return *this; +} + +bool const_iterator::operator==(const const_iterator &RHS) const { +  return Path.begin() == RHS.Path.begin() && Position == RHS.Position; +} + +ptrdiff_t const_iterator::operator-(const const_iterator &RHS) const { +  return Position - RHS.Position; +} + +reverse_iterator rbegin(StringRef Path, Style style) { +  reverse_iterator I; +  I.Path = Path; +  I.Position = Path.size(); +  I.S = style; +  return ++I; +} + +reverse_iterator rend(StringRef Path) { +  reverse_iterator I; +  I.Path = Path; +  I.Component = Path.substr(0, 0); +  I.Position = 0; +  return I; +} + +reverse_iterator &reverse_iterator::operator++() { +  // If we're at the end and the previous char was a '/', return '.' unless +  // we are the root path. +  size_t root_dir_pos = root_dir_start(Path, S); +  if (Position == Path.size() && Path.size() > root_dir_pos + 1 && +      is_separator(Path[Position - 1], S)) { +    --Position; +    Component = "."; +    return *this; +  } + +  // Skip separators unless it's the root directory. +  size_t end_pos = Position; + +  while (end_pos > 0 && (end_pos - 1) != root_dir_pos && +         is_separator(Path[end_pos - 1], S)) +    --end_pos; + +  // Find next separator. +  size_t start_pos = filename_pos(Path.substr(0, end_pos), S); +  Component = Path.slice(start_pos, end_pos); +  Position = start_pos; +  return *this; +} + +bool reverse_iterator::operator==(const reverse_iterator &RHS) const { +  return Path.begin() == RHS.Path.begin() && Component == RHS.Component && +         Position == RHS.Position; +} + +ptrdiff_t reverse_iterator::operator-(const reverse_iterator &RHS) const { +  return Position - RHS.Position; +} + +StringRef root_path(StringRef path, Style style) { +  const_iterator b = begin(path, style), pos = b, e = end(path); +  if (b != e) { +    bool has_net = +        b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0]; +    bool has_drive = (real_style(style) == Style::windows) && b->endswith(":"); + +    if (has_net || has_drive) { +      if ((++pos != e) && is_separator((*pos)[0], style)) { +        // {C:/,//net/}, so get the first two components. +        return path.substr(0, b->size() + pos->size()); +      } else { +        // just {C:,//net}, return the first component. +        return *b; +      } +    } + +    // POSIX style root directory. +    if (is_separator((*b)[0], style)) { +      return *b; +    } +  } + +  return StringRef(); +} + +StringRef root_name(StringRef path, Style style) { +  const_iterator b = begin(path, style), e = end(path); +  if (b != e) { +    bool has_net = +        b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0]; +    bool has_drive = (real_style(style) == Style::windows) && b->endswith(":"); + +    if (has_net || has_drive) { +      // just {C:,//net}, return the first component. +      return *b; +    } +  } + +  // No path or no name. +  return StringRef(); +} + +StringRef root_directory(StringRef path, Style style) { +  const_iterator b = begin(path, style), pos = b, e = end(path); +  if (b != e) { +    bool has_net = +        b->size() > 2 && is_separator((*b)[0], style) && (*b)[1] == (*b)[0]; +    bool has_drive = (real_style(style) == Style::windows) && b->endswith(":"); + +    if ((has_net || has_drive) && +        // {C:,//net}, skip to the next component. +        (++pos != e) && is_separator((*pos)[0], style)) { +      return *pos; +    } + +    // POSIX style root directory. +    if (!has_net && is_separator((*b)[0], style)) { +      return *b; +    } +  } + +  // No path or no root. +  return StringRef(); +} + +StringRef relative_path(StringRef path, Style style) { +  StringRef root = root_path(path, style); +  return path.substr(root.size()); +} + +void append(SmallVectorImpl<char> &path, Style style, const Twine &a, +            const Twine &b, const Twine &c, const Twine &d) { +  SmallString<32> a_storage; +  SmallString<32> b_storage; +  SmallString<32> c_storage; +  SmallString<32> d_storage; + +  SmallVector<StringRef, 4> components; +  if (!a.isTriviallyEmpty()) components.push_back(a.toStringRef(a_storage)); +  if (!b.isTriviallyEmpty()) components.push_back(b.toStringRef(b_storage)); +  if (!c.isTriviallyEmpty()) components.push_back(c.toStringRef(c_storage)); +  if (!d.isTriviallyEmpty()) components.push_back(d.toStringRef(d_storage)); + +  for (auto &component : components) { +    bool path_has_sep = +        !path.empty() && is_separator(path[path.size() - 1], style); +    bool component_has_sep = +        !component.empty() && is_separator(component[0], style); +    bool is_root_name = has_root_name(component, style); + +    if (path_has_sep) { +      // Strip separators from beginning of component. +      size_t loc = component.find_first_not_of(separators(style)); +      StringRef c = component.substr(loc); + +      // Append it. +      path.append(c.begin(), c.end()); +      continue; +    } + +    if (!component_has_sep && !(path.empty() || is_root_name)) { +      // Add a separator. +      path.push_back(preferred_separator(style)); +    } + +    path.append(component.begin(), component.end()); +  } +} + +void append(SmallVectorImpl<char> &path, const Twine &a, const Twine &b, +            const Twine &c, const Twine &d) { +  append(path, Style::native, a, b, c, d); +} + +void append(SmallVectorImpl<char> &path, const_iterator begin, +            const_iterator end, Style style) { +  for (; begin != end; ++begin) +    path::append(path, style, *begin); +} + +StringRef parent_path(StringRef path, Style style) { +  size_t end_pos = parent_path_end(path, style); +  if (end_pos == StringRef::npos) +    return StringRef(); +  else +    return path.substr(0, end_pos); +} + +void remove_filename(SmallVectorImpl<char> &path, Style style) { +  size_t end_pos = parent_path_end(StringRef(path.begin(), path.size()), style); +  if (end_pos != StringRef::npos) +    path.set_size(end_pos); +} + +void replace_extension(SmallVectorImpl<char> &path, const Twine &extension, +                       Style style) { +  StringRef p(path.begin(), path.size()); +  SmallString<32> ext_storage; +  StringRef ext = extension.toStringRef(ext_storage); + +  // Erase existing extension. +  size_t pos = p.find_last_of('.'); +  if (pos != StringRef::npos && pos >= filename_pos(p, style)) +    path.set_size(pos); + +  // Append '.' if needed. +  if (ext.size() > 0 && ext[0] != '.') +    path.push_back('.'); + +  // Append extension. +  path.append(ext.begin(), ext.end()); +} + +void replace_path_prefix(SmallVectorImpl<char> &Path, +                         const StringRef &OldPrefix, const StringRef &NewPrefix, +                         Style style) { +  if (OldPrefix.empty() && NewPrefix.empty()) +    return; + +  StringRef OrigPath(Path.begin(), Path.size()); +  if (!OrigPath.startswith(OldPrefix)) +    return; + +  // If prefixes have the same size we can simply copy the new one over. +  if (OldPrefix.size() == NewPrefix.size()) { +    std::copy(NewPrefix.begin(), NewPrefix.end(), Path.begin()); +    return; +  } + +  StringRef RelPath = OrigPath.substr(OldPrefix.size()); +  SmallString<256> NewPath; +  path::append(NewPath, style, NewPrefix); +  path::append(NewPath, style, RelPath); +  Path.swap(NewPath); +} + +void native(const Twine &path, SmallVectorImpl<char> &result, Style style) { +  assert((!path.isSingleStringRef() || +          path.getSingleStringRef().data() != result.data()) && +         "path and result are not allowed to overlap!"); +  // Clear result. +  result.clear(); +  path.toVector(result); +  native(result, style); +} + +void native(SmallVectorImpl<char> &Path, Style style) { +  if (Path.empty()) +    return; +  if (real_style(style) == Style::windows) { +    std::replace(Path.begin(), Path.end(), '/', '\\'); +    if (Path[0] == '~' && (Path.size() == 1 || is_separator(Path[1], style))) { +      SmallString<128> PathHome; +      home_directory(PathHome); +      PathHome.append(Path.begin() + 1, Path.end()); +      Path = PathHome; +    } +  } else { +    for (auto PI = Path.begin(), PE = Path.end(); PI < PE; ++PI) { +      if (*PI == '\\') { +        auto PN = PI + 1; +        if (PN < PE && *PN == '\\') +          ++PI; // increment once, the for loop will move over the escaped slash +        else +          *PI = '/'; +      } +    } +  } +} + +std::string convert_to_slash(StringRef path, Style style) { +  if (real_style(style) != Style::windows) +    return path; + +  std::string s = path.str(); +  std::replace(s.begin(), s.end(), '\\', '/'); +  return s; +} + +StringRef filename(StringRef path, Style style) { return *rbegin(path, style); } + +StringRef stem(StringRef path, Style style) { +  StringRef fname = filename(path, style); +  size_t pos = fname.find_last_of('.'); +  if (pos == StringRef::npos) +    return fname; +  else +    if ((fname.size() == 1 && fname == ".") || +        (fname.size() == 2 && fname == "..")) +      return fname; +    else +      return fname.substr(0, pos); +} + +StringRef extension(StringRef path, Style style) { +  StringRef fname = filename(path, style); +  size_t pos = fname.find_last_of('.'); +  if (pos == StringRef::npos) +    return StringRef(); +  else +    if ((fname.size() == 1 && fname == ".") || +        (fname.size() == 2 && fname == "..")) +      return StringRef(); +    else +      return fname.substr(pos); +} + +bool is_separator(char value, Style style) { +  if (value == '/') +    return true; +  if (real_style(style) == Style::windows) +    return value == '\\'; +  return false; +} + +StringRef get_separator(Style style) { +  if (real_style(style) == Style::windows) +    return "\\"; +  return "/"; +} + +bool has_root_name(const Twine &path, Style style) { +  SmallString<128> path_storage; +  StringRef p = path.toStringRef(path_storage); + +  return !root_name(p, style).empty(); +} + +bool has_root_directory(const Twine &path, Style style) { +  SmallString<128> path_storage; +  StringRef p = path.toStringRef(path_storage); + +  return !root_directory(p, style).empty(); +} + +bool has_root_path(const Twine &path, Style style) { +  SmallString<128> path_storage; +  StringRef p = path.toStringRef(path_storage); + +  return !root_path(p, style).empty(); +} + +bool has_relative_path(const Twine &path, Style style) { +  SmallString<128> path_storage; +  StringRef p = path.toStringRef(path_storage); + +  return !relative_path(p, style).empty(); +} + +bool has_filename(const Twine &path, Style style) { +  SmallString<128> path_storage; +  StringRef p = path.toStringRef(path_storage); + +  return !filename(p, style).empty(); +} + +bool has_parent_path(const Twine &path, Style style) { +  SmallString<128> path_storage; +  StringRef p = path.toStringRef(path_storage); + +  return !parent_path(p, style).empty(); +} + +bool has_stem(const Twine &path, Style style) { +  SmallString<128> path_storage; +  StringRef p = path.toStringRef(path_storage); + +  return !stem(p, style).empty(); +} + +bool has_extension(const Twine &path, Style style) { +  SmallString<128> path_storage; +  StringRef p = path.toStringRef(path_storage); + +  return !extension(p, style).empty(); +} + +bool is_absolute(const Twine &path, Style style) { +  SmallString<128> path_storage; +  StringRef p = path.toStringRef(path_storage); + +  bool rootDir = has_root_directory(p, style); +  bool rootName = +      (real_style(style) != Style::windows) || has_root_name(p, style); + +  return rootDir && rootName; +} + +bool is_relative(const Twine &path, Style style) { +  return !is_absolute(path, style); +} + +StringRef remove_leading_dotslash(StringRef Path, Style style) { +  // Remove leading "./" (or ".//" or "././" etc.) +  while (Path.size() > 2 && Path[0] == '.' && is_separator(Path[1], style)) { +    Path = Path.substr(2); +    while (Path.size() > 0 && is_separator(Path[0], style)) +      Path = Path.substr(1); +  } +  return Path; +} + +static SmallString<256> remove_dots(StringRef path, bool remove_dot_dot, +                                    Style style) { +  SmallVector<StringRef, 16> components; + +  // Skip the root path, then look for traversal in the components. +  StringRef rel = path::relative_path(path, style); +  for (StringRef C : +       llvm::make_range(path::begin(rel, style), path::end(rel))) { +    if (C == ".") +      continue; +    // Leading ".." will remain in the path unless it's at the root. +    if (remove_dot_dot && C == "..") { +      if (!components.empty() && components.back() != "..") { +        components.pop_back(); +        continue; +      } +      if (path::is_absolute(path, style)) +        continue; +    } +    components.push_back(C); +  } + +  SmallString<256> buffer = path::root_path(path, style); +  for (StringRef C : components) +    path::append(buffer, style, C); +  return buffer; +} + +bool remove_dots(SmallVectorImpl<char> &path, bool remove_dot_dot, +                 Style style) { +  StringRef p(path.data(), path.size()); + +  SmallString<256> result = remove_dots(p, remove_dot_dot, style); +  if (result == path) +    return false; + +  path.swap(result); +  return true; +} + +} // end namespace path + +namespace fs { + +std::error_code getUniqueID(const Twine Path, UniqueID &Result) { +  file_status Status; +  std::error_code EC = status(Path, Status); +  if (EC) +    return EC; +  Result = Status.getUniqueID(); +  return std::error_code(); +} + +std::error_code createUniqueFile(const Twine &Model, int &ResultFd, +                                 SmallVectorImpl<char> &ResultPath, +                                 unsigned Mode) { +  return createUniqueEntity(Model, ResultFd, ResultPath, false, Mode, FS_File); +} + +std::error_code createUniqueFile(const Twine &Model, +                                 SmallVectorImpl<char> &ResultPath) { +  int Dummy; +  return createUniqueEntity(Model, Dummy, ResultPath, false, 0, FS_Name); +} + +static std::error_code +createTemporaryFile(const Twine &Model, int &ResultFD, +                    llvm::SmallVectorImpl<char> &ResultPath, FSEntity Type) { +  SmallString<128> Storage; +  StringRef P = Model.toNullTerminatedStringRef(Storage); +  assert(P.find_first_of(separators(Style::native)) == StringRef::npos && +         "Model must be a simple filename."); +  // Use P.begin() so that createUniqueEntity doesn't need to recreate Storage. +  return createUniqueEntity(P.begin(), ResultFD, ResultPath, +                            true, owner_read | owner_write, Type); +} + +static std::error_code +createTemporaryFile(const Twine &Prefix, StringRef Suffix, int &ResultFD, +                    llvm::SmallVectorImpl<char> &ResultPath, FSEntity Type) { +  const char *Middle = Suffix.empty() ? "-%%%%%%" : "-%%%%%%."; +  return createTemporaryFile(Prefix + Middle + Suffix, ResultFD, ResultPath, +                             Type); +} + +std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix, +                                    int &ResultFD, +                                    SmallVectorImpl<char> &ResultPath) { +  return createTemporaryFile(Prefix, Suffix, ResultFD, ResultPath, FS_File); +} + +std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix, +                                    SmallVectorImpl<char> &ResultPath) { +  int Dummy; +  return createTemporaryFile(Prefix, Suffix, Dummy, ResultPath, FS_Name); +} + + +// This is a mkdtemp with a different pattern. We use createUniqueEntity mostly +// for consistency. We should try using mkdtemp. +std::error_code createUniqueDirectory(const Twine &Prefix, +                                      SmallVectorImpl<char> &ResultPath) { +  int Dummy; +  return createUniqueEntity(Prefix + "-%%%%%%", Dummy, ResultPath, +                            true, 0, FS_Dir); +} + +static std::error_code make_absolute(const Twine ¤t_directory, +                                     SmallVectorImpl<char> &path, +                                     bool use_current_directory) { +  StringRef p(path.data(), path.size()); + +  bool rootDirectory = path::has_root_directory(p); +  bool rootName = +      (real_style(Style::native) != Style::windows) || path::has_root_name(p); + +  // Already absolute. +  if (rootName && rootDirectory) +    return std::error_code(); + +  // All of the following conditions will need the current directory. +  SmallString<128> current_dir; +  if (use_current_directory) +    current_directory.toVector(current_dir); +  else if (std::error_code ec = current_path(current_dir)) +    return ec; + +  // Relative path. Prepend the current directory. +  if (!rootName && !rootDirectory) { +    // Append path to the current directory. +    path::append(current_dir, p); +    // Set path to the result. +    path.swap(current_dir); +    return std::error_code(); +  } + +  if (!rootName && rootDirectory) { +    StringRef cdrn = path::root_name(current_dir); +    SmallString<128> curDirRootName(cdrn.begin(), cdrn.end()); +    path::append(curDirRootName, p); +    // Set path to the result. +    path.swap(curDirRootName); +    return std::error_code(); +  } + +  if (rootName && !rootDirectory) { +    StringRef pRootName      = path::root_name(p); +    StringRef bRootDirectory = path::root_directory(current_dir); +    StringRef bRelativePath  = path::relative_path(current_dir); +    StringRef pRelativePath  = path::relative_path(p); + +    SmallString<128> res; +    path::append(res, pRootName, bRootDirectory, bRelativePath, pRelativePath); +    path.swap(res); +    return std::error_code(); +  } + +  llvm_unreachable("All rootName and rootDirectory combinations should have " +                   "occurred above!"); +} + +std::error_code make_absolute(const Twine ¤t_directory, +                              SmallVectorImpl<char> &path) { +  return make_absolute(current_directory, path, true); +} + +std::error_code make_absolute(SmallVectorImpl<char> &path) { +  return make_absolute(Twine(), path, false); +} + +std::error_code create_directories(const Twine &Path, bool IgnoreExisting, +                                   perms Perms) { +  SmallString<128> PathStorage; +  StringRef P = Path.toStringRef(PathStorage); + +  // Be optimistic and try to create the directory +  std::error_code EC = create_directory(P, IgnoreExisting, Perms); +  // If we succeeded, or had any error other than the parent not existing, just +  // return it. +  if (EC != errc::no_such_file_or_directory) +    return EC; + +  // We failed because of a no_such_file_or_directory, try to create the +  // parent. +  StringRef Parent = path::parent_path(P); +  if (Parent.empty()) +    return EC; + +  if ((EC = create_directories(Parent, IgnoreExisting, Perms))) +      return EC; + +  return create_directory(P, IgnoreExisting, Perms); +} + +std::error_code copy_file(const Twine &From, const Twine &To) { +  int ReadFD, WriteFD; +  if (std::error_code EC = openFileForRead(From, ReadFD)) +    return EC; +  if (std::error_code EC = openFileForWrite(To, WriteFD, F_None)) { +    close(ReadFD); +    return EC; +  } + +  const size_t BufSize = 4096; +  char *Buf = new char[BufSize]; +  int BytesRead = 0, BytesWritten = 0; +  for (;;) { +    BytesRead = read(ReadFD, Buf, BufSize); +    if (BytesRead <= 0) +      break; +    while (BytesRead) { +      BytesWritten = write(WriteFD, Buf, BytesRead); +      if (BytesWritten < 0) +        break; +      BytesRead -= BytesWritten; +    } +    if (BytesWritten < 0) +      break; +  } +  close(ReadFD); +  close(WriteFD); +  delete[] Buf; + +  if (BytesRead < 0 || BytesWritten < 0) +    return std::error_code(errno, std::generic_category()); +  return std::error_code(); +} + +ErrorOr<MD5::MD5Result> md5_contents(int FD) { +  MD5 Hash; + +  constexpr size_t BufSize = 4096; +  std::vector<uint8_t> Buf(BufSize); +  int BytesRead = 0; +  for (;;) { +    BytesRead = read(FD, Buf.data(), BufSize); +    if (BytesRead <= 0) +      break; +    Hash.update(makeArrayRef(Buf.data(), BytesRead)); +  } + +  if (BytesRead < 0) +    return std::error_code(errno, std::generic_category()); +  MD5::MD5Result Result; +  Hash.final(Result); +  return Result; +} + +ErrorOr<MD5::MD5Result> md5_contents(const Twine &Path) { +  int FD; +  if (auto EC = openFileForRead(Path, FD)) +    return EC; + +  auto Result = md5_contents(FD); +  close(FD); +  return Result; +} + +bool exists(file_status status) { +  return status_known(status) && status.type() != file_type::file_not_found; +} + +bool status_known(file_status s) { +  return s.type() != file_type::status_error; +} + +file_type get_file_type(const Twine &Path, bool Follow) { +  file_status st; +  if (status(Path, st, Follow)) +    return file_type::status_error; +  return st.type(); +} + +bool is_directory(file_status status) { +  return status.type() == file_type::directory_file; +} + +std::error_code is_directory(const Twine &path, bool &result) { +  file_status st; +  if (std::error_code ec = status(path, st)) +    return ec; +  result = is_directory(st); +  return std::error_code(); +} + +bool is_regular_file(file_status status) { +  return status.type() == file_type::regular_file; +} + +std::error_code is_regular_file(const Twine &path, bool &result) { +  file_status st; +  if (std::error_code ec = status(path, st)) +    return ec; +  result = is_regular_file(st); +  return std::error_code(); +} + +bool is_symlink_file(file_status status) { +  return status.type() == file_type::symlink_file; +} + +std::error_code is_symlink_file(const Twine &path, bool &result) { +  file_status st; +  if (std::error_code ec = status(path, st, false)) +    return ec; +  result = is_symlink_file(st); +  return std::error_code(); +} + +bool is_other(file_status status) { +  return exists(status) && +         !is_regular_file(status) && +         !is_directory(status); +} + +std::error_code is_other(const Twine &Path, bool &Result) { +  file_status FileStatus; +  if (std::error_code EC = status(Path, FileStatus)) +    return EC; +  Result = is_other(FileStatus); +  return std::error_code(); +} + +void directory_entry::replace_filename(const Twine &filename, file_status st) { +  SmallString<128> path = path::parent_path(Path); +  path::append(path, filename); +  Path = path.str(); +  Status = st; +} + +std::error_code directory_entry::status(file_status &result) const { +  return fs::status(Path, result, FollowSymlinks); +} + +ErrorOr<perms> getPermissions(const Twine &Path) { +  file_status Status; +  if (std::error_code EC = status(Path, Status)) +    return EC; + +  return Status.permissions(); +} + +} // end namespace fs +} // end namespace sys +} // end namespace llvm + +// Include the truly platform-specific parts. +#if defined(LLVM_ON_UNIX) +#include "Unix/Path.inc" +#endif +#if defined(LLVM_ON_WIN32) +#include "Windows/Path.inc" +#endif + +namespace llvm { +namespace sys { +namespace path { + +bool user_cache_directory(SmallVectorImpl<char> &Result, const Twine &Path1, +                          const Twine &Path2, const Twine &Path3) { +  if (getUserCacheDir(Result)) { +    append(Result, Path1, Path2, Path3); +    return true; +  } +  return false; +} + +} // end namespace path +} // end namsspace sys +} // end namespace llvm | 
