1 files changed, 1148 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Support/Path.cpp b/contrib/llvm/lib/Support/Path.cpp
new file mode 100644
index 0000000..4952f59
--- /dev/null
+++ b/contrib/llvm/lib/Support/Path.cpp
@@ -0,0 +1,1148 @@
+//===-- 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/COFF.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.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;
+
+#ifdef LLVM_ON_WIN32
+  const char *separators = "\\/";
+  const char preferred_separator = '\\';
+#else
+  const char  separators = '/';
+  const char preferred_separator = '/';
+#endif
+
+  StringRef find_first_component(StringRef path) {
+    // 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;
+
+#ifdef LLVM_ON_WIN32
+    // C:
+    if (path.size() >= 2 && std::isalpha(static_cast<unsigned char>(path[0])) &&
+        path[1] == ':')
+      return path.substr(0, 2);
+#endif
+
+    // //net
+    if ((path.size() > 2) &&
+        is_separator(path[0]) &&
+        path[0] == path[1] &&
+        !is_separator(path[2])) {
+      // Find the next directory separator.
+      size_t end = path.find_first_of(separators, 2);
+      return path.substr(0, end);
+    }
+
+    // {/,\}
+    if (is_separator(path[0]))
+      return path.substr(0, 1);
+
+    // * {file,directory}name
+    size_t end = path.find_first_of(separators);
+    return path.substr(0, end);
+  }
+
+  size_t filename_pos(StringRef str) {
+    if (str.size() == 2 &&
+        is_separator(str[0]) &&
+        str[0] == str[1])
+      return 0;
+
+    if (str.size() > 0 && is_separator(str[str.size() - 1]))
+      return str.size() - 1;
+
+    size_t pos = str.find_last_of(separators, str.size() - 1);
+
+#ifdef LLVM_ON_WIN32
+    if (pos == StringRef::npos)
+      pos = str.find_last_of(':', str.size() - 2);
+#endif
+
+    if (pos == StringRef::npos ||
+        (pos == 1 && is_separator(str[0])))
+      return 0;
+
+    return pos + 1;
+  }
+
+  size_t root_dir_start(StringRef str) {
+    // case "c:/"
+#ifdef LLVM_ON_WIN32
+    if (str.size() > 2 &&
+        str[1] == ':' &&
+        is_separator(str[2]))
+      return 2;
+#endif
+
+    // case "//"
+    if (str.size() == 2 &&
+        is_separator(str[0]) &&
+        str[0] == str[1])
+      return StringRef::npos;
+
+    // case "//net"
+    if (str.size() > 3 &&
+        is_separator(str[0]) &&
+        str[0] == str[1] &&
+        !is_separator(str[2])) {
+      return str.find_first_of(separators, 2);
+    }
+
+    // case "/"
+    if (str.size() > 0 && is_separator(str[0]))
+      return 0;
+
+    return StringRef::npos;
+  }
+
+  size_t parent_path_end(StringRef path) {
+    size_t end_pos = filename_pos(path);
+
+    bool filename_was_sep = path.size() > 0 && is_separator(path[end_pos]);
+
+    // Skip separators except for root dir.
+    size_t root_dir_pos = root_dir_start(path.substr(0, end_pos));
+
+    while(end_pos > 0 &&
+          (end_pos - 1) != root_dir_pos &&
+          is_separator(path[end_pos - 1]))
+      --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) {
+  const_iterator i;
+  i.Path      = path;
+  i.Component = find_first_component(path);
+  i.Position  = 0;
+  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]) &&
+    Component[1] == Component[0] &&
+    !is_separator(Component[2]);
+
+  // Handle separators.
+  if (is_separator(Path[Position])) {
+    // Root dir.
+    if (was_net
+#ifdef LLVM_ON_WIN32
+        // c:/
+        || Component.endswith(":")
+#endif
+        ) {
+      Component = Path.substr(Position, 1);
+      return *this;
+    }
+
+    // Skip extra separators.
+    while (Position != Path.size() &&
+           is_separator(Path[Position])) {
+      ++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, 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) {
+  reverse_iterator I;
+  I.Path = Path;
+  I.Position = Path.size();
+  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);
+  if (Position == Path.size() &&
+      Path.size() > root_dir_pos + 1 &&
+      is_separator(Path[Position - 1])) {
+    --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]))
+    --end_pos;
+
+  // Find next separator.
+  size_t start_pos = filename_pos(Path.substr(0, end_pos));
+  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;
+}
+
+StringRef root_path(StringRef path) {
+  const_iterator b = begin(path),
+                 pos = b,
+                 e = end(path);
+  if (b != e) {
+    bool has_net = b->size() > 2 && is_separator((*b)[0]) && (*b)[1] == (*b)[0];
+    bool has_drive =
+#ifdef LLVM_ON_WIN32
+      b->endswith(":");
+#else
+      false;
+#endif
+
+    if (has_net || has_drive) {
+      if ((++pos != e) && is_separator((*pos)[0])) {
+        // {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])) {
+      return *b;
+    }
+  }
+
+  return StringRef();
+}
+
+StringRef root_name(StringRef path) {
+  const_iterator b = begin(path),
+                 e = end(path);
+  if (b != e) {
+    bool has_net = b->size() > 2 && is_separator((*b)[0]) && (*b)[1] == (*b)[0];
+    bool has_drive =
+#ifdef LLVM_ON_WIN32
+      b->endswith(":");
+#else
+      false;
+#endif
+
+    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) {
+  const_iterator b = begin(path),
+                 pos = b,
+                 e = end(path);
+  if (b != e) {
+    bool has_net = b->size() > 2 && is_separator((*b)[0]) && (*b)[1] == (*b)[0];
+    bool has_drive =
+#ifdef LLVM_ON_WIN32
+      b->endswith(":");
+#else
+      false;
+#endif
+
+    if ((has_net || has_drive) &&
+        // {C:,//net}, skip to the next component.
+        (++pos != e) && is_separator((*pos)[0])) {
+      return *pos;
+    }
+
+    // POSIX style root directory.
+    if (!has_net && is_separator((*b)[0])) {
+      return *b;
+    }
+  }
+
+  // No path or no root.
+  return StringRef();
+}
+
+StringRef relative_path(StringRef path) {
+  StringRef root = root_path(path);
+  return path.substr(root.size());
+}
+
+void append(SmallVectorImpl<char> &path, 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]);
+    bool component_has_sep = !component.empty() && is_separator(component[0]);
+    bool is_root_name = has_root_name(component);
+
+    if (path_has_sep) {
+      // Strip separators from beginning of component.
+      size_t loc = component.find_first_not_of(separators);
+      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);
+    }
+
+    path.append(component.begin(), component.end());
+  }
+}
+
+void append(SmallVectorImpl<char> &path,
+            const_iterator begin, const_iterator end) {
+  for (; begin != end; ++begin)
+    path::append(path, *begin);
+}
+
+StringRef parent_path(StringRef path) {
+  size_t end_pos = parent_path_end(path);
+  if (end_pos == StringRef::npos)
+    return StringRef();
+  else
+    return path.substr(0, end_pos);
+}
+
+void remove_filename(SmallVectorImpl<char> &path) {
+  size_t end_pos = parent_path_end(StringRef(path.begin(), path.size()));
+  if (end_pos != StringRef::npos)
+    path.set_size(end_pos);
+}
+
+void replace_extension(SmallVectorImpl<char> &path, const Twine &extension) {
+  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))
+    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 native(const Twine &path, SmallVectorImpl<char> &result) {
+  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);
+}
+
+void native(SmallVectorImpl<char> &Path) {
+#ifdef LLVM_ON_WIN32
+  std::replace(Path.begin(), Path.end(), '/', '\\');
+#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 = '/';
+    }
+  }
+#endif
+}
+
+StringRef filename(StringRef path) {
+  return *rbegin(path);
+}
+
+StringRef stem(StringRef path) {
+  StringRef fname = filename(path);
+  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) {
+  StringRef fname = filename(path);
+  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) {
+  switch(value) {
+#ifdef LLVM_ON_WIN32
+    case '\\': // fall through
+#endif
+    case '/': return true;
+    default: return false;
+  }
+}
+
+static const char preferred_separator_string[] = { preferred_separator, '\0' };
+
+StringRef get_separator() {
+  return preferred_separator_string;
+}
+
+bool has_root_name(const Twine &path) {
+  SmallString<128> path_storage;
+  StringRef p = path.toStringRef(path_storage);
+
+  return !root_name(p).empty();
+}
+
+bool has_root_directory(const Twine &path) {
+  SmallString<128> path_storage;
+  StringRef p = path.toStringRef(path_storage);
+
+  return !root_directory(p).empty();
+}
+
+bool has_root_path(const Twine &path) {
+  SmallString<128> path_storage;
+  StringRef p = path.toStringRef(path_storage);
+
+  return !root_path(p).empty();
+}
+
+bool has_relative_path(const Twine &path) {
+  SmallString<128> path_storage;
+  StringRef p = path.toStringRef(path_storage);
+
+  return !relative_path(p).empty();
+}
+
+bool has_filename(const Twine &path) {
+  SmallString<128> path_storage;
+  StringRef p = path.toStringRef(path_storage);
+
+  return !filename(p).empty();
+}
+
+bool has_parent_path(const Twine &path) {
+  SmallString<128> path_storage;
+  StringRef p = path.toStringRef(path_storage);
+
+  return !parent_path(p).empty();
+}
+
+bool has_stem(const Twine &path) {
+  SmallString<128> path_storage;
+  StringRef p = path.toStringRef(path_storage);
+
+  return !stem(p).empty();
+}
+
+bool has_extension(const Twine &path) {
+  SmallString<128> path_storage;
+  StringRef p = path.toStringRef(path_storage);
+
+  return !extension(p).empty();
+}
+
+bool is_absolute(const Twine &path) {
+  SmallString<128> path_storage;
+  StringRef p = path.toStringRef(path_storage);
+
+  bool rootDir = has_root_directory(p),
+#ifdef LLVM_ON_WIN32
+       rootName = has_root_name(p);
+#else
+       rootName = true;
+#endif
+
+  return rootDir && rootName;
+}
+
+bool is_relative(const Twine &path) { return !is_absolute(path); }
+
+StringRef remove_leading_dotslash(StringRef Path) {
+  // Remove leading "./" (or ".//" or "././" etc.)
+  while (Path.size() > 2 && Path[0] == '.' && is_separator(Path[1])) {
+    Path = Path.substr(2);
+    while (Path.size() > 0 && is_separator(Path[0]))
+      Path = Path.substr(1);
+  }
+  return Path;
+}
+
+static SmallString<256> remove_dots(StringRef path, bool remove_dot_dot) {
+  SmallVector<StringRef, 16> components;
+
+  // Skip the root path, then look for traversal in the components.
+  StringRef rel = path::relative_path(path);
+  for (StringRef C : llvm::make_range(path::begin(rel), path::end(rel))) {
+    if (C == ".")
+      continue;
+    if (remove_dot_dot) {
+      if (C == "..") {
+        if (!components.empty())
+          components.pop_back();
+        continue;
+      }
+    }
+    components.push_back(C);
+  }
+
+  SmallString<256> buffer = path::root_path(path);
+  for (StringRef C : components)
+    path::append(buffer, C);
+  return buffer;
+}
+
+bool remove_dots(SmallVectorImpl<char> &path, bool remove_dot_dot) {
+  StringRef p(path.data(), path.size());
+
+  SmallString<256> result = remove_dots(p, remove_dot_dot);
+  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) == 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 &current_directory,
+                                     SmallVectorImpl<char> &path,
+                                     bool use_current_directory) {
+  StringRef p(path.data(), path.size());
+
+  bool rootDirectory = path::has_root_directory(p),
+#ifdef LLVM_ON_WIN32
+       rootName = path::has_root_name(p);
+#else
+       rootName = true;
+#endif
+
+  // 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 &current_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();
+}
+
+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;
+}
+
+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_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;
+}
+
+/// @brief Identify the magic in magic.
+file_magic identify_magic(StringRef Magic) {
+  if (Magic.size() < 4)
+    return file_magic::unknown;
+  switch ((unsigned char)Magic[0]) {
+    case 0x00: {
+      // COFF bigobj or short import library file
+      if (Magic[1] == (char)0x00 && Magic[2] == (char)0xff &&
+          Magic[3] == (char)0xff) {
+        size_t MinSize = offsetof(COFF::BigObjHeader, UUID) + sizeof(COFF::BigObjMagic);
+        if (Magic.size() < MinSize)
+          return file_magic::coff_import_library;
+
+        int BigObjVersion = read16le(
+            Magic.data() + offsetof(COFF::BigObjHeader, Version));
+        if (BigObjVersion < COFF::BigObjHeader::MinBigObjectVersion)
+          return file_magic::coff_import_library;
+
+        const char *Start = Magic.data() + offsetof(COFF::BigObjHeader, UUID);
+        if (memcmp(Start, COFF::BigObjMagic, sizeof(COFF::BigObjMagic)) != 0)
+          return file_magic::coff_import_library;
+        return file_magic::coff_object;
+      }
+      // Windows resource file
+      const char Expected[] = { 0, 0, 0, 0, '\x20', 0, 0, 0, '\xff' };
+      if (Magic.size() >= sizeof(Expected) &&
+          memcmp(Magic.data(), Expected, sizeof(Expected)) == 0)
+        return file_magic::windows_resource;
+      // 0x0000 = COFF unknown machine type
+      if (Magic[1] == 0)
+        return file_magic::coff_object;
+      break;
+    }
+    case 0xDE:  // 0x0B17C0DE = BC wraper
+      if (Magic[1] == (char)0xC0 && Magic[2] == (char)0x17 &&
+          Magic[3] == (char)0x0B)
+        return file_magic::bitcode;
+      break;
+    case 'B':
+      if (Magic[1] == 'C' && Magic[2] == (char)0xC0 && Magic[3] == (char)0xDE)
+        return file_magic::bitcode;
+      break;
+    case '!':
+      if (Magic.size() >= 8)
+        if (memcmp(Magic.data(), "!<arch>\n", 8) == 0 ||
+            memcmp(Magic.data(), "!<thin>\n", 8) == 0)
+          return file_magic::archive;
+      break;
+
+    case '\177':
+      if (Magic.size() >= 18 && Magic[1] == 'E' && Magic[2] == 'L' &&
+          Magic[3] == 'F') {
+        bool Data2MSB = Magic[5] == 2;
+        unsigned high = Data2MSB ? 16 : 17;
+        unsigned low  = Data2MSB ? 17 : 16;
+        if (Magic[high] == 0)
+          switch (Magic[low]) {
+            default: return file_magic::elf;
+            case 1: return file_magic::elf_relocatable;
+            case 2: return file_magic::elf_executable;
+            case 3: return file_magic::elf_shared_object;
+            case 4: return file_magic::elf_core;
+          }
+        else
+          // It's still some type of ELF file.
+          return file_magic::elf;
+      }
+      break;
+
+    case 0xCA:
+      if (Magic[1] == char(0xFE) && Magic[2] == char(0xBA) &&
+          Magic[3] == char(0xBE)) {
+        // This is complicated by an overlap with Java class files.
+        // See the Mach-O section in /usr/share/file/magic for details.
+        if (Magic.size() >= 8 && Magic[7] < 43)
+          return file_magic::macho_universal_binary;
+      }
+      break;
+
+      // The two magic numbers for mach-o are:
+      // 0xfeedface - 32-bit mach-o
+      // 0xfeedfacf - 64-bit mach-o
+    case 0xFE:
+    case 0xCE:
+    case 0xCF: {
+      uint16_t type = 0;
+      if (Magic[0] == char(0xFE) && Magic[1] == char(0xED) &&
+          Magic[2] == char(0xFA) &&
+          (Magic[3] == char(0xCE) || Magic[3] == char(0xCF))) {
+        /* Native endian */
+        if (Magic.size() >= 16) type = Magic[14] << 8 | Magic[15];
+      } else if ((Magic[0] == char(0xCE) || Magic[0] == char(0xCF)) &&
+                 Magic[1] == char(0xFA) && Magic[2] == char(0xED) &&
+                 Magic[3] == char(0xFE)) {
+        /* Reverse endian */
+        if (Magic.size() >= 14) type = Magic[13] << 8 | Magic[12];
+      }
+      switch (type) {
+        default: break;
+        case 1: return file_magic::macho_object;
+        case 2: return file_magic::macho_executable;
+        case 3: return file_magic::macho_fixed_virtual_memory_shared_lib;
+        case 4: return file_magic::macho_core;
+        case 5: return file_magic::macho_preload_executable;
+        case 6: return file_magic::macho_dynamically_linked_shared_lib;
+        case 7: return file_magic::macho_dynamic_linker;
+        case 8: return file_magic::macho_bundle;
+        case 9: return file_magic::macho_dynamically_linked_shared_lib_stub;
+        case 10: return file_magic::macho_dsym_companion;
+        case 11: return file_magic::macho_kext_bundle;
+      }
+      break;
+    }
+    case 0xF0: // PowerPC Windows
+    case 0x83: // Alpha 32-bit
+    case 0x84: // Alpha 64-bit
+    case 0x66: // MPS R4000 Windows
+    case 0x50: // mc68K
+    case 0x4c: // 80386 Windows
+    case 0xc4: // ARMNT Windows
+      if (Magic[1] == 0x01)
+        return file_magic::coff_object;
+
+    case 0x90: // PA-RISC Windows
+    case 0x68: // mc68K Windows
+      if (Magic[1] == 0x02)
+        return file_magic::coff_object;
+      break;
+
+    case 'M': // Possible MS-DOS stub on Windows PE file
+      if (Magic[1] == 'Z') {
+        uint32_t off = read32le(Magic.data() + 0x3c);
+        // PE/COFF file, either EXE or DLL.
+        if (off < Magic.size() &&
+            memcmp(Magic.data()+off, COFF::PEMagic, sizeof(COFF::PEMagic)) == 0)
+          return file_magic::pecoff_executable;
+      }
+      break;
+
+    case 0x64: // x86-64 Windows.
+      if (Magic[1] == char(0x86))
+        return file_magic::coff_object;
+      break;
+
+    default:
+      break;
+  }
+  return file_magic::unknown;
+}
+
+std::error_code identify_magic(const Twine &Path, file_magic &Result) {
+  int FD;
+  if (std::error_code EC = openFileForRead(Path, FD))
+    return EC;
+
+  char Buffer[32];
+  int Length = read(FD, Buffer, sizeof(Buffer));
+  if (close(FD) != 0 || Length < 0)
+    return std::error_code(errno, std::generic_category());
+
+  Result = identify_magic(StringRef(Buffer, Length));
+  return std::error_code();
+}
+
+std::error_code directory_entry::status(file_status &result) const {
+  return fs::status(Path, result);
+}
+
+} // 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