Rename PathV2 to just Path now that it is the only one.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185015 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 870 insertions, 0 deletions

diff --git a/lib/Support/Unix/Path.inc b/lib/Support/Unix/Path.inc
new file mode 100644
index 0000000000..94f872077a
--- /dev/null
+++ b/lib/Support/Unix/Path.inc
@@ -0,0 +1,870 @@
+//===- llvm/Support/Unix/Path.inc - Unix Path Implementation ----*- C++ -*-===//
+//
+//                     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 Unix specific implementation of the Path API.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+#include "Unix.h"
+#include "llvm/Support/Process.h"
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+#if HAVE_DIRENT_H
+# include <dirent.h>
+# define NAMLEN(dirent) strlen((dirent)->d_name)
+#else
+# define dirent direct
+# define NAMLEN(dirent) (dirent)->d_namlen
+# if HAVE_SYS_NDIR_H
+#  include <sys/ndir.h>
+# endif
+# if HAVE_SYS_DIR_H
+#  include <sys/dir.h>
+# endif
+# if HAVE_NDIR_H
+#  include <ndir.h>
+# endif
+#endif
+#if HAVE_STDIO_H
+#include <stdio.h>
+#endif
+#if HAVE_LIMITS_H
+#include <limits.h>
+#endif
+
+#ifdef __APPLE__
+#include <mach-o/dyld.h>
+#endif
+
+// Both stdio.h and cstdio are included via different pathes and
+// stdcxx's cstdio doesn't include stdio.h, so it doesn't #undef the macros
+// either.
+#undef ferror
+#undef feof
+
+// For GNU Hurd
+#if defined(__GNU__) && !defined(PATH_MAX)
+# define PATH_MAX 4096
+#endif
+
+using namespace llvm;
+
+namespace {
+  /// This class automatically closes the given file descriptor when it goes out
+  /// of scope. You can take back explicit ownership of the file descriptor by
+  /// calling take(). The destructor does not verify that close was successful.
+  /// Therefore, never allow this class to call close on a file descriptor that
+  /// has been read from or written to.
+  struct AutoFD {
+    int FileDescriptor;
+
+    AutoFD(int fd) : FileDescriptor(fd) {}
+    ~AutoFD() {
+      if (FileDescriptor >= 0)
+        ::close(FileDescriptor);
+    }
+
+    int take() {
+      int ret = FileDescriptor;
+      FileDescriptor = -1;
+      return ret;
+    }
+
+    operator int() const {return FileDescriptor;}
+  };
+
+  error_code TempDir(SmallVectorImpl<char> &result) {
+    // FIXME: Don't use TMPDIR if program is SUID or SGID enabled.
+    const char *dir = 0;
+    (dir = std::getenv("TMPDIR" )) ||
+    (dir = std::getenv("TMP"    )) ||
+    (dir = std::getenv("TEMP"   )) ||
+    (dir = std::getenv("TEMPDIR")) ||
+#ifdef P_tmpdir
+    (dir = P_tmpdir) ||
+#endif
+    (dir = "/tmp");
+
+    result.clear();
+    StringRef d(dir);
+    result.append(d.begin(), d.end());
+    return error_code::success();
+  }
+}
+
+namespace llvm {
+namespace sys  {
+namespace fs {
+#if defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
+    defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__) || \
+    defined(__linux__) || defined(__CYGWIN__)
+static int
+test_dir(char buf[PATH_MAX], char ret[PATH_MAX],
+    const char *dir, const char *bin)
+{
+  struct stat sb;
+
+  snprintf(buf, PATH_MAX, "%s/%s", dir, bin);
+  if (realpath(buf, ret) == NULL)
+    return (1);
+  if (stat(buf, &sb) != 0)
+    return (1);
+
+  return (0);
+}
+
+static char *
+getprogpath(char ret[PATH_MAX], const char *bin)
+{
+  char *pv, *s, *t, buf[PATH_MAX];
+
+  /* First approach: absolute path. */
+  if (bin[0] == '/') {
+    if (test_dir(buf, ret, "/", bin) == 0)
+      return (ret);
+    return (NULL);
+  }
+
+  /* Second approach: relative path. */
+  if (strchr(bin, '/') != NULL) {
+    if (getcwd(buf, PATH_MAX) == NULL)
+      return (NULL);
+    if (test_dir(buf, ret, buf, bin) == 0)
+      return (ret);
+    return (NULL);
+  }
+
+  /* Third approach: $PATH */
+  if ((pv = getenv("PATH")) == NULL)
+    return (NULL);
+  s = pv = strdup(pv);
+  if (pv == NULL)
+    return (NULL);
+  while ((t = strsep(&s, ":")) != NULL) {
+    if (test_dir(buf, ret, t, bin) == 0) {
+      free(pv);
+      return (ret);
+    }
+  }
+  free(pv);
+  return (NULL);
+}
+#endif // __FreeBSD__ || __NetBSD__ || __FreeBSD_kernel__
+
+/// GetMainExecutable - Return the path to the main executable, given the
+/// value of argv[0] from program startup.
+std::string getMainExecutable(const char *argv0, void *MainAddr) {
+#if defined(__APPLE__)
+  // On OS X the executable path is saved to the stack by dyld. Reading it
+  // from there is much faster than calling dladdr, especially for large
+  // binaries with symbols.
+  char exe_path[MAXPATHLEN];
+  uint32_t size = sizeof(exe_path);
+  if (_NSGetExecutablePath(exe_path, &size) == 0) {
+    char link_path[MAXPATHLEN];
+    if (realpath(exe_path, link_path))
+      return link_path;
+  }
+#elif defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
+      defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__)
+  char exe_path[PATH_MAX];
+
+  if (getprogpath(exe_path, argv0) != NULL)
+    return exe_path;
+#elif defined(__linux__) || defined(__CYGWIN__)
+  char exe_path[MAXPATHLEN];
+  StringRef aPath("/proc/self/exe");
+  if (sys::fs::exists(aPath)) {
+      // /proc is not always mounted under Linux (chroot for example).
+      ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path));
+      if (len >= 0)
+          return StringRef(exe_path, len);
+  } else {
+      // Fall back to the classical detection.
+      if (getprogpath(exe_path, argv0) != NULL)
+          return exe_path;
+  }
+#elif defined(HAVE_DLFCN_H)
+  // Use dladdr to get executable path if available.
+  Dl_info DLInfo;
+  int err = dladdr(MainAddr, &DLInfo);
+  if (err == 0)
+    return "";
+
+  // If the filename is a symlink, we need to resolve and return the location of
+  // the actual executable.
+  char link_path[MAXPATHLEN];
+  if (realpath(DLInfo.dli_fname, link_path))
+    return link_path;
+#else
+#error GetMainExecutable is not implemented on this host yet.
+#endif
+  return "";
+}
+
+TimeValue file_status::getLastModificationTime() const {
+  TimeValue Ret;
+  Ret.fromEpochTime(fs_st_mtime);
+  return Ret;
+}
+
+error_code current_path(SmallVectorImpl<char> &result) {
+#ifdef MAXPATHLEN
+  result.reserve(MAXPATHLEN);
+#else
+// For GNU Hurd
+  result.reserve(1024);
+#endif
+
+  while (true) {
+    if (::getcwd(result.data(), result.capacity()) == 0) {
+      // See if there was a real error.
+      if (errno != errc::not_enough_memory)
+        return error_code(errno, system_category());
+      // Otherwise there just wasn't enough space.
+      result.reserve(result.capacity() * 2);
+    } else
+      break;
+  }
+
+  result.set_size(strlen(result.data()));
+  return error_code::success();
+}
+
+error_code copy_file(const Twine &from, const Twine &to, copy_option copt) {
+ // Get arguments.
+  SmallString<128> from_storage;
+  SmallString<128> to_storage;
+  StringRef f = from.toNullTerminatedStringRef(from_storage);
+  StringRef t = to.toNullTerminatedStringRef(to_storage);
+
+  const size_t buf_sz = 32768;
+  char buffer[buf_sz];
+  int from_file = -1, to_file = -1;
+
+  // Open from.
+  if ((from_file = ::open(f.begin(), O_RDONLY)) < 0)
+    return error_code(errno, system_category());
+  AutoFD from_fd(from_file);
+
+  // Stat from.
+  struct stat from_stat;
+  if (::stat(f.begin(), &from_stat) != 0)
+    return error_code(errno, system_category());
+
+  // Setup to flags.
+  int to_flags = O_CREAT | O_WRONLY;
+  if (copt == copy_option::fail_if_exists)
+    to_flags |= O_EXCL;
+
+  // Open to.
+  if ((to_file = ::open(t.begin(), to_flags, from_stat.st_mode)) < 0)
+    return error_code(errno, system_category());
+  AutoFD to_fd(to_file);
+
+  // Copy!
+  ssize_t sz, sz_read = 1, sz_write;
+  while (sz_read > 0 &&
+         (sz_read = ::read(from_fd, buffer, buf_sz)) > 0) {
+    // Allow for partial writes - see Advanced Unix Programming (2nd Ed.),
+    // Marc Rochkind, Addison-Wesley, 2004, page 94
+    sz_write = 0;
+    do {
+      if ((sz = ::write(to_fd, buffer + sz_write, sz_read - sz_write)) < 0) {
+        sz_read = sz;  // cause read loop termination.
+        break;         // error.
+      }
+      sz_write += sz;
+    } while (sz_write < sz_read);
+  }
+
+  // After all the file operations above the return value of close actually
+  // matters.
+  if (::close(from_fd.take()) < 0) sz_read = -1;
+  if (::close(to_fd.take()) < 0) sz_read = -1;
+
+  // Check for errors.
+  if (sz_read < 0)
+    return error_code(errno, system_category());
+
+  return error_code::success();
+}
+
+error_code create_directory(const Twine &path, bool &existed) {
+  SmallString<128> path_storage;
+  StringRef p = path.toNullTerminatedStringRef(path_storage);
+
+  if (::mkdir(p.begin(), S_IRWXU | S_IRWXG) == -1) {
+    if (errno != errc::file_exists)
+      return error_code(errno, system_category());
+    existed = true;
+  } else
+    existed = false;
+
+  return error_code::success();
+}
+
+error_code create_hard_link(const Twine &to, const Twine &from) {
+  // Get arguments.
+  SmallString<128> from_storage;
+  SmallString<128> to_storage;
+  StringRef f = from.toNullTerminatedStringRef(from_storage);
+  StringRef t = to.toNullTerminatedStringRef(to_storage);
+
+  if (::link(t.begin(), f.begin()) == -1)
+    return error_code(errno, system_category());
+
+  return error_code::success();
+}
+
+error_code create_symlink(const Twine &to, const Twine &from) {
+  // Get arguments.
+  SmallString<128> from_storage;
+  SmallString<128> to_storage;
+  StringRef f = from.toNullTerminatedStringRef(from_storage);
+  StringRef t = to.toNullTerminatedStringRef(to_storage);
+
+  if (::symlink(t.begin(), f.begin()) == -1)
+    return error_code(errno, system_category());
+
+  return error_code::success();
+}
+
+error_code remove(const Twine &path, bool &existed) {
+  SmallString<128> path_storage;
+  StringRef p = path.toNullTerminatedStringRef(path_storage);
+
+  struct stat buf;
+  if (stat(p.begin(), &buf) != 0) {
+    if (errno != errc::no_such_file_or_directory)
+      return error_code(errno, system_category());
+    existed = false;
+    return error_code::success();
+  }
+
+  // Note: this check catches strange situations. In all cases, LLVM should
+  // only be involved in the creation and deletion of regular files.  This
+  // check ensures that what we're trying to erase is a regular file. It
+  // effectively prevents LLVM from erasing things like /dev/null, any block
+  // special file, or other things that aren't "regular" files.
+  if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode))
+    return make_error_code(errc::operation_not_permitted);
+
+  if (::remove(p.begin()) == -1) {
+    if (errno != errc::no_such_file_or_directory)
+      return error_code(errno, system_category());
+    existed = false;
+  } else
+    existed = true;
+
+  return error_code::success();
+}
+
+error_code rename(const Twine &from, const Twine &to) {
+  // Get arguments.
+  SmallString<128> from_storage;
+  SmallString<128> to_storage;
+  StringRef f = from.toNullTerminatedStringRef(from_storage);
+  StringRef t = to.toNullTerminatedStringRef(to_storage);
+
+  if (::rename(f.begin(), t.begin()) == -1) {
+    // If it's a cross device link, copy then delete, otherwise return the error
+    if (errno == EXDEV) {
+      if (error_code ec = copy_file(from, to, copy_option::overwrite_if_exists))
+        return ec;
+      bool Existed;
+      if (error_code ec = remove(from, Existed))
+        return ec;
+    } else
+      return error_code(errno, system_category());
+  }
+
+  return error_code::success();
+}
+
+error_code resize_file(const Twine &path, uint64_t size) {
+  SmallString<128> path_storage;
+  StringRef p = path.toNullTerminatedStringRef(path_storage);
+
+  if (::truncate(p.begin(), size) == -1)
+    return error_code(errno, system_category());
+
+  return error_code::success();
+}
+
+error_code exists(const Twine &path, bool &result) {
+  SmallString<128> path_storage;
+  StringRef p = path.toNullTerminatedStringRef(path_storage);
+
+  if (::access(p.begin(), F_OK) == -1) {
+    if (errno != errc::no_such_file_or_directory)
+      return error_code(errno, system_category());
+    result = false;
+  } else
+    result = true;
+
+  return error_code::success();
+}
+
+bool can_write(const Twine &Path) {
+  SmallString<128> PathStorage;
+  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
+  return 0 == access(P.begin(), W_OK);
+}
+
+bool can_execute(const Twine &Path) {
+  SmallString<128> PathStorage;
+  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
+
+  if (0 != access(P.begin(), R_OK | X_OK))
+    return false;
+  struct stat buf;
+  if (0 != stat(P.begin(), &buf))
+    return false;
+  if (!S_ISREG(buf.st_mode))
+    return false;
+  return true;
+}
+
+bool equivalent(file_status A, file_status B) {
+  assert(status_known(A) && status_known(B));
+  return A.fs_st_dev == B.fs_st_dev &&
+         A.fs_st_ino == B.fs_st_ino;
+}
+
+error_code equivalent(const Twine &A, const Twine &B, bool &result) {
+  file_status fsA, fsB;
+  if (error_code ec = status(A, fsA)) return ec;
+  if (error_code ec = status(B, fsB)) return ec;
+  result = equivalent(fsA, fsB);
+  return error_code::success();
+}
+
+error_code file_size(const Twine &path, uint64_t &result) {
+  SmallString<128> path_storage;
+  StringRef p = path.toNullTerminatedStringRef(path_storage);
+
+  struct stat status;
+  if (::stat(p.begin(), &status) == -1)
+    return error_code(errno, system_category());
+  if (!S_ISREG(status.st_mode))
+    return make_error_code(errc::operation_not_permitted);
+
+  result = status.st_size;
+  return error_code::success();
+}
+
+error_code getUniqueID(const Twine Path, uint64_t &Result) {
+  SmallString<128> Storage;
+  StringRef P = Path.toNullTerminatedStringRef(Storage);
+
+  struct stat Status;
+  if (::stat(P.begin(), &Status) != 0)
+    return error_code(errno, system_category());
+
+  Result = Status.st_ino;
+  return error_code::success();
+}
+
+error_code status(const Twine &path, file_status &result) {
+  SmallString<128> path_storage;
+  StringRef p = path.toNullTerminatedStringRef(path_storage);
+
+  struct stat status;
+  if (::stat(p.begin(), &status) != 0) {
+    error_code ec(errno, system_category());
+    if (ec == errc::no_such_file_or_directory)
+      result = file_status(file_type::file_not_found);
+    else
+      result = file_status(file_type::status_error);
+    return ec;
+  }
+
+  perms prms = static_cast<perms>(status.st_mode & perms_mask);
+  
+  if (S_ISDIR(status.st_mode))
+    result = file_status(file_type::directory_file, prms);
+  else if (S_ISREG(status.st_mode))
+    result = file_status(file_type::regular_file, prms);
+  else if (S_ISBLK(status.st_mode))
+    result = file_status(file_type::block_file, prms);
+  else if (S_ISCHR(status.st_mode))
+    result = file_status(file_type::character_file, prms);
+  else if (S_ISFIFO(status.st_mode))
+    result = file_status(file_type::fifo_file, prms);
+  else if (S_ISSOCK(status.st_mode))
+    result = file_status(file_type::socket_file, prms);
+  else
+    result = file_status(file_type::type_unknown, prms);
+
+  result.fs_st_dev = status.st_dev;
+  result.fs_st_ino = status.st_ino;
+  result.fs_st_mtime = status.st_mtime;
+  result.fs_st_uid = status.st_uid;
+  result.fs_st_gid = status.st_gid;
+
+  return error_code::success();
+}
+
+// Modifies permissions on a file.
+error_code permissions(const Twine &path, perms prms) {
+  if ((prms & add_perms) && (prms & remove_perms))
+    llvm_unreachable("add_perms and remove_perms are mutually exclusive");
+
+  // Get current permissions
+  // FIXME: We only need this stat for add_perms and remove_perms.
+  file_status info;
+  if (error_code ec = status(path, info)) {
+    return ec;
+  }
+  
+  // Set updated permissions.
+  SmallString<128> path_storage;
+  StringRef p = path.toNullTerminatedStringRef(path_storage);
+  perms permsToSet;
+  if (prms & add_perms) {
+    permsToSet = (info.permissions() | prms) & perms_mask;
+  } else if (prms & remove_perms) {
+    permsToSet = (info.permissions() & ~prms) & perms_mask;
+  } else {
+    permsToSet = prms & perms_mask;
+  }
+  if (::chmod(p.begin(), static_cast<mode_t>(permsToSet))) {
+    return error_code(errno, system_category()); 
+  }
+
+  return error_code::success();
+}
+
+error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
+  timeval Times[2];
+  Times[0].tv_sec = Time.toPosixTime();
+  Times[0].tv_usec = 0;
+  Times[1] = Times[0];
+  if (::futimes(FD, Times))
+    return error_code(errno, system_category());
+  return error_code::success();
+}
+
+error_code unique_file(const Twine &model, int &result_fd,
+                       SmallVectorImpl<char> &result_path,
+                       bool makeAbsolute, unsigned mode) {
+  SmallString<128> Model;
+  model.toVector(Model);
+  // Null terminate.
+  Model.c_str();
+
+  if (makeAbsolute) {
+    // Make model absolute by prepending a temp directory if it's not already.
+    bool absolute = path::is_absolute(Twine(Model));
+    if (!absolute) {
+      SmallString<128> TDir;
+      if (error_code ec = TempDir(TDir)) return ec;
+      path::append(TDir, Twine(Model));
+      Model.swap(TDir);
+    }
+  }
+
+  // From here on, DO NOT modify model. It may be needed if the randomly chosen
+  // path already exists.
+  SmallString<128> RandomPath = Model;
+
+retry_random_path:
+  // Replace '%' with random chars.
+  for (unsigned i = 0, e = Model.size(); i != e; ++i) {
+    if (Model[i] == '%')
+      RandomPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];
+  }
+
+  // Make sure we don't fall into an infinite loop by constantly trying
+  // to create the parent path.
+  bool TriedToCreateParent = false;
+
+  // Try to open + create the file.
+rety_open_create:
+  int RandomFD = ::open(RandomPath.c_str(), O_RDWR | O_CREAT | O_EXCL, mode);
+  if (RandomFD == -1) {
+    int SavedErrno = errno;
+    // If the file existed, try again, otherwise, error.
+    if (SavedErrno == errc::file_exists)
+      goto retry_random_path;
+    // If path prefix doesn't exist, try to create it.
+    if (SavedErrno == errc::no_such_file_or_directory && !TriedToCreateParent) {
+      TriedToCreateParent = true;
+      StringRef p(RandomPath);
+      SmallString<64> dir_to_create;
+      for (path::const_iterator i = path::begin(p),
+                                e = --path::end(p); i != e; ++i) {
+        path::append(dir_to_create, *i);
+        bool Exists;
+        if (error_code ec = exists(Twine(dir_to_create), Exists)) return ec;
+        if (!Exists) {
+          // Don't try to create network paths.
+          if (i->size() > 2 && (*i)[0] == '/' &&
+                               (*i)[1] == '/' &&
+                               (*i)[2] != '/')
+            return make_error_code(errc::no_such_file_or_directory);
+          if (::mkdir(dir_to_create.c_str(), 0700) == -1 &&
+              errno != errc::file_exists)
+            return error_code(errno, system_category());
+        }
+      }
+      goto rety_open_create;
+    }
+
+    return error_code(SavedErrno, system_category());
+  }
+
+   // Make the path absolute.
+  char real_path_buff[PATH_MAX + 1];
+  if (realpath(RandomPath.c_str(), real_path_buff) == NULL) {
+    int error = errno;
+    ::close(RandomFD);
+    ::unlink(RandomPath.c_str());
+    return error_code(error, system_category());
+  }
+
+  result_path.clear();
+  StringRef d(real_path_buff);
+  result_path.append(d.begin(), d.end());
+
+  result_fd = RandomFD;
+  return error_code::success();
+}
+
+error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
+  AutoFD ScopedFD(FD);
+  if (!CloseFD)
+    ScopedFD.take();
+
+  // Figure out how large the file is.
+  struct stat FileInfo;
+  if (fstat(FD, &FileInfo) == -1)
+    return error_code(errno, system_category());
+  uint64_t FileSize = FileInfo.st_size;
+
+  if (Size == 0)
+    Size = FileSize;
+  else if (FileSize < Size) {
+    // We need to grow the file.
+    if (ftruncate(FD, Size) == -1)
+      return error_code(errno, system_category());
+  }
+
+  int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
+  int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
+#ifdef MAP_FILE
+  flags |= MAP_FILE;
+#endif
+  Mapping = ::mmap(0, Size, prot, flags, FD, Offset);
+  if (Mapping == MAP_FAILED)
+    return error_code(errno, system_category());
+  return error_code::success();
+}
+
+mapped_file_region::mapped_file_region(const Twine &path,
+                                       mapmode mode,
+                                       uint64_t length,
+                                       uint64_t offset,
+                                       error_code &ec)
+  : Mode(mode)
+  , Size(length)
+  , Mapping() {
+  // Make sure that the requested size fits within SIZE_T.
+  if (length > std::numeric_limits<size_t>::max()) {
+    ec = make_error_code(errc::invalid_argument);
+    return;
+  }
+
+  SmallString<128> path_storage;
+  StringRef name = path.toNullTerminatedStringRef(path_storage);
+  int oflags = (mode == readonly) ? O_RDONLY : O_RDWR;
+  int ofd = ::open(name.begin(), oflags);
+  if (ofd == -1) {
+    ec = error_code(errno, system_category());
+    return;
+  }
+
+  ec = init(ofd, true, offset);
+  if (ec)
+    Mapping = 0;
+}
+
+mapped_file_region::mapped_file_region(int fd,
+                                       bool closefd,
+                                       mapmode mode,
+                                       uint64_t length,
+                                       uint64_t offset,
+                                       error_code &ec)
+  : Mode(mode)
+  , Size(length)
+  , Mapping() {
+  // Make sure that the requested size fits within SIZE_T.
+  if (length > std::numeric_limits<size_t>::max()) {
+    ec = make_error_code(errc::invalid_argument);
+    return;
+  }
+
+  ec = init(fd, closefd, offset);
+  if (ec)
+    Mapping = 0;
+}
+
+mapped_file_region::~mapped_file_region() {
+  if (Mapping)
+    ::munmap(Mapping, Size);
+}
+
+#if LLVM_HAS_RVALUE_REFERENCES
+mapped_file_region::mapped_file_region(mapped_file_region &&other)
+  : Mode(other.Mode), Size(other.Size), Mapping(other.Mapping) {
+  other.Mapping = 0;
+}
+#endif
+
+mapped_file_region::mapmode mapped_file_region::flags() const {
+  assert(Mapping && "Mapping failed but used anyway!");
+  return Mode;
+}
+
+uint64_t mapped_file_region::size() const {
+  assert(Mapping && "Mapping failed but used anyway!");
+  return Size;
+}
+
+char *mapped_file_region::data() const {
+  assert(Mapping && "Mapping failed but used anyway!");
+  assert(Mode != readonly && "Cannot get non const data for readonly mapping!");
+  return reinterpret_cast<char*>(Mapping);
+}
+
+const char *mapped_file_region::const_data() const {
+  assert(Mapping && "Mapping failed but used anyway!");
+  return reinterpret_cast<const char*>(Mapping);
+}
+
+int mapped_file_region::alignment() {
+  return process::get_self()->page_size();
+}
+
+error_code detail::directory_iterator_construct(detail::DirIterState &it,
+                                                StringRef path){
+  SmallString<128> path_null(path);
+  DIR *directory = ::opendir(path_null.c_str());
+  if (directory == 0)
+    return error_code(errno, system_category());
+
+  it.IterationHandle = reinterpret_cast<intptr_t>(directory);
+  // Add something for replace_filename to replace.
+  path::append(path_null, ".");
+  it.CurrentEntry = directory_entry(path_null.str());
+  return directory_iterator_increment(it);
+}
+
+error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
+  if (it.IterationHandle)
+    ::closedir(reinterpret_cast<DIR *>(it.IterationHandle));
+  it.IterationHandle = 0;
+  it.CurrentEntry = directory_entry();
+  return error_code::success();
+}
+
+error_code detail::directory_iterator_increment(detail::DirIterState &it) {
+  errno = 0;
+  dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
+  if (cur_dir == 0 && errno != 0) {
+    return error_code(errno, system_category());
+  } else if (cur_dir != 0) {
+    StringRef name(cur_dir->d_name, NAMLEN(cur_dir));
+    if ((name.size() == 1 && name[0] == '.') ||
+        (name.size() == 2 && name[0] == '.' && name[1] == '.'))
+      return directory_iterator_increment(it);
+    it.CurrentEntry.replace_filename(name);
+  } else
+    return directory_iterator_destruct(it);
+
+  return error_code::success();
+}
+
+error_code get_magic(const Twine &path, uint32_t len,
+                     SmallVectorImpl<char> &result) {
+  SmallString<128> PathStorage;
+  StringRef Path = path.toNullTerminatedStringRef(PathStorage);
+  result.set_size(0);
+
+  // Open path.
+  std::FILE *file = std::fopen(Path.data(), "rb");
+  if (file == 0)
+    return error_code(errno, system_category());
+
+  // Reserve storage.
+  result.reserve(len);
+
+  // Read magic!
+  size_t size = std::fread(result.data(), 1, len, file);
+  if (std::ferror(file) != 0) {
+    std::fclose(file);
+    return error_code(errno, system_category());
+  } else if (size != len) {
+    if (std::feof(file) != 0) {
+      std::fclose(file);
+      result.set_size(size);
+      return make_error_code(errc::value_too_large);
+    }
+  }
+  std::fclose(file);
+  result.set_size(size);
+  return error_code::success();
+}
+
+error_code map_file_pages(const Twine &path, off_t file_offset, size_t size,  
+                                            bool map_writable, void *&result) {
+  SmallString<128> path_storage;
+  StringRef name = path.toNullTerminatedStringRef(path_storage);
+  int oflags = map_writable ? O_RDWR : O_RDONLY;
+  int ofd = ::open(name.begin(), oflags);
+  if ( ofd == -1 )
+    return error_code(errno, system_category());
+  AutoFD fd(ofd);
+  int flags = map_writable ? MAP_SHARED : MAP_PRIVATE;
+  int prot = map_writable ? (PROT_READ|PROT_WRITE) : PROT_READ;
+#ifdef MAP_FILE
+  flags |= MAP_FILE;
+#endif
+  result = ::mmap(0, size, prot, flags, fd, file_offset);
+  if (result == MAP_FAILED) {
+    return error_code(errno, system_category());
+  }
+  
+  return error_code::success();
+}
+
+error_code unmap_file_pages(void *base, size_t size) {
+  if ( ::munmap(base, size) == -1 )
+    return error_code(errno, system_category());
+   
+  return error_code::success();
+}
+
+
+} // end namespace fs
+} // end namespace sys
+} // end namespace llvm