Merge llvm 3.5.0 release from ^/vendor/llvm/dist, resolve conflicts, and

preserve our customizations, where necessary.

1 files changed, 141 insertions, 254 deletions

diff --git a/contrib/llvm/lib/Support/Unix/Path.inc b/contrib/llvm/lib/Support/Unix/Path.inc
index c9dc871..623547a 100644
--- a/contrib/llvm/lib/Support/Unix/Path.inc
+++ b/contrib/llvm/lib/Support/Unix/Path.inc
@@ -17,7 +17,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "Unix.h"
-#include "llvm/Support/Process.h"
 #include <limits.h>
 #include <stdio.h>
 #if HAVE_SYS_STAT_H
@@ -86,95 +85,22 @@ namespace {
 
     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")) ||
+static std::error_code TempDir(SmallVectorImpl<char> &result) {
+  // FIXME: Don't use TMPDIR if program is SUID or SGID enabled.
+  const char *dir = nullptr;
+  (dir = std::getenv("TMPDIR")) || (dir = std::getenv("TMP")) ||
+      (dir = std::getenv("TEMP")) || (dir = std::getenv("TEMPDIR")) ||
 #ifdef P_tmpdir
-    (dir = P_tmpdir) ||
+      (dir = P_tmpdir) ||
 #endif
-    (dir = "/tmp");
-
-    result.clear();
-    StringRef d(dir);
-    result.append(d.begin(), d.end());
-    return error_code::success();
-  }
-}
-
-static 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.
-    bool absolute = sys::path::is_absolute(Twine(ModelStorage));
-    if (!absolute) {
-      SmallString<128> TDir;
-      if (error_code ec = TempDir(TDir)) return ec;
-      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: {
-    int RandomFD = ::open(ResultPath.begin(), 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;
-      return error_code(SavedErrno, system_category());
-    }
-
-    ResultFD = RandomFD;
-    return error_code::success();
-  }
-
-  case FS_Name: {
-    bool Exists;
-    error_code EC = sys::fs::exists(ResultPath.begin(), Exists);
-    if (EC)
-      return EC;
-    if (Exists)
-      goto retry_random_path;
-    return error_code::success();
-  }
+      (dir = "/tmp");
 
-  case FS_Dir: {
-    bool Existed;
-    error_code EC = sys::fs::create_directory(ResultPath.begin(), Existed);
-    if (EC)
-      return EC;
-    if (Existed)
-      goto retry_random_path;
-    return error_code::success();
-  }
-  }
-  llvm_unreachable("Invalid Type");
+  result.clear();
+  StringRef d(dir);
+  result.append(d.begin(), d.end());
+  return std::error_code();
 }
 
 namespace llvm {
@@ -184,15 +110,15 @@ namespace fs {
     defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__) || \
     defined(__linux__) || defined(__CYGWIN__) || defined(__DragonFly__)
 static int
-test_dir(char buf[PATH_MAX], char ret[PATH_MAX],
-    const char *dir, const char *bin)
-{
+test_dir(char ret[PATH_MAX], const char *dir, const char *bin)
+{  
   struct stat sb;
+  char fullpath[PATH_MAX];
 
-  snprintf(buf, PATH_MAX, "%s/%s", dir, bin);
-  if (realpath(buf, ret) == NULL)
+  snprintf(fullpath, PATH_MAX, "%s/%s", dir, bin);
+  if (realpath(fullpath, ret) == NULL)
     return (1);
-  if (stat(buf, &sb) != 0)
+  if (stat(fullpath, &sb) != 0)
     return (1);
 
   return (0);
@@ -201,20 +127,21 @@ test_dir(char buf[PATH_MAX], char ret[PATH_MAX],
 static char *
 getprogpath(char ret[PATH_MAX], const char *bin)
 {
-  char *pv, *s, *t, buf[PATH_MAX];
+  char *pv, *s, *t;
 
   /* First approach: absolute path. */
   if (bin[0] == '/') {
-    if (test_dir(buf, ret, "/", bin) == 0)
+    if (test_dir(ret, "/", bin) == 0)
       return (ret);
     return (NULL);
   }
 
   /* Second approach: relative path. */
   if (strchr(bin, '/') != NULL) {
-    if (getcwd(buf, PATH_MAX) == NULL)
+    char cwd[PATH_MAX];
+    if (getcwd(cwd, PATH_MAX) == NULL)
       return (NULL);
-    if (test_dir(buf, ret, buf, bin) == 0)
+    if (test_dir(ret, cwd, bin) == 0)
       return (ret);
     return (NULL);
   }
@@ -226,7 +153,7 @@ getprogpath(char ret[PATH_MAX], const char *bin)
   if (pv == NULL)
     return (NULL);
   while ((t = strsep(&s, ":")) != NULL) {
-    if (test_dir(buf, ret, t, bin) == 0) {
+    if (test_dir(ret, t, bin) == 0) {
       free(pv);
       return (ret);
     }
@@ -298,7 +225,7 @@ UniqueID file_status::getUniqueID() const {
   return UniqueID(fs_st_dev, fs_st_ino);
 }
 
-error_code current_path(SmallVectorImpl<char> &result) {
+std::error_code current_path(SmallVectorImpl<char> &result) {
   result.clear();
 
   const char *pwd = ::getenv("PWD");
@@ -308,7 +235,7 @@ error_code current_path(SmallVectorImpl<char> &result) {
       !llvm::sys::fs::status(".", DotStatus) &&
       PWDStatus.getUniqueID() == DotStatus.getUniqueID()) {
     result.append(pwd, pwd + strlen(pwd));
-    return error_code::success();
+    return std::error_code();
   }
 
 #ifdef MAXPATHLEN
@@ -319,10 +246,10 @@ error_code current_path(SmallVectorImpl<char> &result) {
 #endif
 
   while (true) {
-    if (::getcwd(result.data(), result.capacity()) == 0) {
+    if (::getcwd(result.data(), result.capacity()) == nullptr) {
       // See if there was a real error.
-      if (errno != errc::not_enough_memory)
-        return error_code(errno, system_category());
+      if (errno != ENOMEM)
+        return std::error_code(errno, std::generic_category());
       // Otherwise there just wasn't enough space.
       result.reserve(result.capacity() * 2);
     } else
@@ -330,37 +257,37 @@ error_code current_path(SmallVectorImpl<char> &result) {
   }
 
   result.set_size(strlen(result.data()));
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code create_directory(const Twine &path, bool &existed) {
+std::error_code create_directory(const Twine &path, bool IgnoreExisting) {
   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;
+    if (errno != EEXIST || !IgnoreExisting)
+      return std::error_code(errno, std::generic_category());
+  }
 
-  return error_code::success();
+  return std::error_code();
 }
 
-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();
+std::error_code normalize_separators(SmallVectorImpl<char> &Path) {
+  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 = '/';
+    }
+  }
+  return std::error_code();
 }
 
-error_code create_symlink(const Twine &to, const Twine &from) {
+// Note that we are using symbolic link because hard links are not supported by
+// all filesystems (SMB doesn't).
+std::error_code create_link(const Twine &to, const Twine &from) {
   // Get arguments.
   SmallString<128> from_storage;
   SmallString<128> to_storage;
@@ -368,21 +295,20 @@ error_code create_symlink(const Twine &to, const Twine &from) {
   StringRef t = to.toNullTerminatedStringRef(to_storage);
 
   if (::symlink(t.begin(), f.begin()) == -1)
-    return error_code(errno, system_category());
+    return std::error_code(errno, std::generic_category());
 
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code remove(const Twine &path, bool &existed) {
+std::error_code remove(const Twine &path, bool IgnoreNonExisting) {
   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();
+  if (lstat(p.begin(), &buf) != 0) {
+    if (errno != ENOENT || !IgnoreNonExisting)
+      return std::error_code(errno, std::generic_category());
+    return std::error_code();
   }
 
   // Note: this check catches strange situations. In all cases, LLVM should
@@ -390,20 +316,18 @@ error_code remove(const Twine &path, bool &existed) {
   // 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))
+  if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode) && !S_ISLNK(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;
+    if (errno != ENOENT || !IgnoreNonExisting)
+      return std::error_code(errno, std::generic_category());
+  }
 
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code rename(const Twine &from, const Twine &to) {
+std::error_code rename(const Twine &from, const Twine &to) {
   // Get arguments.
   SmallString<128> from_storage;
   SmallString<128> to_storage;
@@ -411,33 +335,33 @@ error_code rename(const Twine &from, const Twine &to) {
   StringRef t = to.toNullTerminatedStringRef(to_storage);
 
   if (::rename(f.begin(), t.begin()) == -1)
-    return error_code(errno, system_category());
+    return std::error_code(errno, std::generic_category());
 
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code resize_file(const Twine &path, uint64_t size) {
+std::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 std::error_code(errno, std::generic_category());
 
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code exists(const Twine &path, bool &result) {
+std::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());
+    if (errno != ENOENT)
+      return std::error_code(errno, std::generic_category());
     result = false;
   } else
     result = true;
 
-  return error_code::success();
+  return std::error_code();
 }
 
 bool can_write(const Twine &Path) {
@@ -466,18 +390,20 @@ bool equivalent(file_status A, file_status B) {
          A.fs_st_ino == B.fs_st_ino;
 }
 
-error_code equivalent(const Twine &A, const Twine &B, bool &result) {
+std::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;
+  if (std::error_code ec = status(A, fsA))
+    return ec;
+  if (std::error_code ec = status(B, fsB))
+    return ec;
   result = equivalent(fsA, fsB);
-  return error_code::success();
+  return std::error_code();
 }
 
-static error_code fillStatus(int StatRet, const struct stat &Status,
+static std::error_code fillStatus(int StatRet, const struct stat &Status,
                              file_status &Result) {
   if (StatRet != 0) {
-    error_code ec(errno, system_category());
+    std::error_code ec(errno, std::generic_category());
     if (ec == errc::no_such_file_or_directory)
       Result = file_status(file_type::file_not_found);
     else
@@ -505,10 +431,10 @@ static error_code fillStatus(int StatRet, const struct stat &Status,
       file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_mtime,
                   Status.st_uid, Status.st_gid, Status.st_size);
 
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code status(const Twine &Path, file_status &Result) {
+std::error_code status(const Twine &Path, file_status &Result) {
   SmallString<128> PathStorage;
   StringRef P = Path.toNullTerminatedStringRef(PathStorage);
 
@@ -517,33 +443,36 @@ error_code status(const Twine &Path, file_status &Result) {
   return fillStatus(StatRet, Status, Result);
 }
 
-error_code status(int FD, file_status &Result) {
+std::error_code status(int FD, file_status &Result) {
   struct stat Status;
   int StatRet = ::fstat(FD, &Status);
   return fillStatus(StatRet, Status, Result);
 }
 
-error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
+std::error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
 #if defined(HAVE_FUTIMENS)
   timespec Times[2];
-  Times[0].tv_sec = Time.toPosixTime();
+  Times[0].tv_sec = Time.toEpochTime();
   Times[0].tv_nsec = 0;
   Times[1] = Times[0];
   if (::futimens(FD, Times))
+    return std::error_code(errno, std::generic_category());
+  return std::error_code();
 #elif defined(HAVE_FUTIMES)
   timeval Times[2];
-  Times[0].tv_sec = Time.toPosixTime();
+  Times[0].tv_sec = Time.toEpochTime();
   Times[0].tv_usec = 0;
   Times[1] = Times[0];
   if (::futimes(FD, Times))
+    return std::error_code(errno, std::generic_category());
+  return std::error_code();
 #else
-#error Missing futimes() and futimens()
+#warning Missing futimes() and futimens()
+  return make_error_code(errc::function_not_supported);
 #endif
-    return error_code(errno, system_category());
-  return error_code::success();
 }
 
-error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
+std::error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
   AutoFD ScopedFD(FD);
   if (!CloseFD)
     ScopedFD.take();
@@ -551,7 +480,7 @@ error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
   // Figure out how large the file is.
   struct stat FileInfo;
   if (fstat(FD, &FileInfo) == -1)
-    return error_code(errno, system_category());
+    return std::error_code(errno, std::generic_category());
   uint64_t FileSize = FileInfo.st_size;
 
   if (Size == 0)
@@ -559,7 +488,7 @@ error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
   else if (FileSize < Size) {
     // We need to grow the file.
     if (ftruncate(FD, Size) == -1)
-      return error_code(errno, system_category());
+      return std::error_code(errno, std::generic_category());
   }
 
   int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
@@ -567,17 +496,17 @@ error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
 #ifdef MAP_FILE
   flags |= MAP_FILE;
 #endif
-  Mapping = ::mmap(0, Size, prot, flags, FD, Offset);
+  Mapping = ::mmap(nullptr, Size, prot, flags, FD, Offset);
   if (Mapping == MAP_FAILED)
-    return error_code(errno, system_category());
-  return error_code::success();
+    return std::error_code(errno, std::generic_category());
+  return std::error_code();
 }
 
 mapped_file_region::mapped_file_region(const Twine &path,
                                        mapmode mode,
                                        uint64_t length,
                                        uint64_t offset,
-                                       error_code &ec)
+                                       std::error_code &ec)
   : Mode(mode)
   , Size(length)
   , Mapping() {
@@ -592,13 +521,13 @@ mapped_file_region::mapped_file_region(const Twine &path,
   int oflags = (mode == readonly) ? O_RDONLY : O_RDWR;
   int ofd = ::open(name.begin(), oflags);
   if (ofd == -1) {
-    ec = error_code(errno, system_category());
+    ec = std::error_code(errno, std::generic_category());
     return;
   }
 
   ec = init(ofd, true, offset);
   if (ec)
-    Mapping = 0;
+    Mapping = nullptr;
 }
 
 mapped_file_region::mapped_file_region(int fd,
@@ -606,7 +535,7 @@ mapped_file_region::mapped_file_region(int fd,
                                        mapmode mode,
                                        uint64_t length,
                                        uint64_t offset,
-                                       error_code &ec)
+                                       std::error_code &ec)
   : Mode(mode)
   , Size(length)
   , Mapping() {
@@ -618,7 +547,7 @@ mapped_file_region::mapped_file_region(int fd,
 
   ec = init(fd, closefd, offset);
   if (ec)
-    Mapping = 0;
+    Mapping = nullptr;
 }
 
 mapped_file_region::~mapped_file_region() {
@@ -626,12 +555,10 @@ mapped_file_region::~mapped_file_region() {
     ::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;
+  other.Mapping = nullptr;
 }
-#endif
 
 mapped_file_region::mapmode mapped_file_region::flags() const {
   assert(Mapping && "Mapping failed but used anyway!");
@@ -645,7 +572,7 @@ uint64_t mapped_file_region::size() const {
 
 char *mapped_file_region::data() const {
   assert(Mapping && "Mapping failed but used anyway!");
-  assert(Mode != readonly && "Cannot get non const data for readonly mapping!");
+  assert(Mode != readonly && "Cannot get non-const data for readonly mapping!");
   return reinterpret_cast<char*>(Mapping);
 }
 
@@ -658,12 +585,12 @@ int mapped_file_region::alignment() {
   return process::get_self()->page_size();
 }
 
-error_code detail::directory_iterator_construct(detail::DirIterState &it,
+std::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());
+  if (!directory)
+    return std::error_code(errno, std::generic_category());
 
   it.IterationHandle = reinterpret_cast<intptr_t>(directory);
   // Add something for replace_filename to replace.
@@ -672,20 +599,20 @@ error_code detail::directory_iterator_construct(detail::DirIterState &it,
   return directory_iterator_increment(it);
 }
 
-error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
+std::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();
+  return std::error_code();
 }
 
-error_code detail::directory_iterator_increment(detail::DirIterState &it) {
+std::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) {
+  if (cur_dir == nullptr && errno != 0) {
+    return std::error_code(errno, std::generic_category());
+  } else if (cur_dir != nullptr) {
     StringRef name(cur_dir->d_name, NAMLEN(cur_dir));
     if ((name.size() == 1 && name[0] == '.') ||
         (name.size() == 2 && name[0] == '.' && name[1] == '.'))
@@ -694,86 +621,31 @@ error_code detail::directory_iterator_increment(detail::DirIterState &it) {
   } 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();
+  return std::error_code();
 }
 
-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();
-}
-
-error_code openFileForRead(const Twine &Name, int &ResultFD) {
+std::error_code openFileForRead(const Twine &Name, int &ResultFD) {
   SmallString<128> Storage;
   StringRef P = Name.toNullTerminatedStringRef(Storage);
   while ((ResultFD = open(P.begin(), O_RDONLY)) < 0) {
     if (errno != EINTR)
-      return error_code(errno, system_category());
+      return std::error_code(errno, std::generic_category());
   }
-  return error_code::success();
+  return std::error_code();
 }
 
-error_code openFileForWrite(const Twine &Name, int &ResultFD,
+std::error_code openFileForWrite(const Twine &Name, int &ResultFD,
                             sys::fs::OpenFlags Flags, unsigned Mode) {
   // Verify that we don't have both "append" and "excl".
   assert((!(Flags & sys::fs::F_Excl) || !(Flags & sys::fs::F_Append)) &&
          "Cannot specify both 'excl' and 'append' file creation flags!");
 
-  int OpenFlags = O_WRONLY | O_CREAT;
+  int OpenFlags = O_CREAT;
+
+  if (Flags & F_RW)
+    OpenFlags |= O_RDWR;
+  else
+    OpenFlags |= O_WRONLY;
 
   if (Flags & F_Append)
     OpenFlags |= O_APPEND;
@@ -787,11 +659,26 @@ error_code openFileForWrite(const Twine &Name, int &ResultFD,
   StringRef P = Name.toNullTerminatedStringRef(Storage);
   while ((ResultFD = open(P.begin(), OpenFlags, Mode)) < 0) {
     if (errno != EINTR)
-      return error_code(errno, system_category());
+      return std::error_code(errno, std::generic_category());
   }
-  return error_code::success();
+  return std::error_code();
 }
 
 } // end namespace fs
+
+namespace path {
+
+bool home_directory(SmallVectorImpl<char> &result) {
+  if (char *RequestedDir = getenv("HOME")) {
+    result.clear();
+    result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
+    return true;
+  }
+
+  return false;
+}
+
+} // end namespace path
+
 } // end namespace sys
 } // end namespace llvm