[Support] Remove getPathFromOpenFD, it was unused

[rnk]

Summary

It was added to support clang warnings about includes with case
mismatches, but it ended up not being necessary.

llvm/include/llvm/Support/FileSystem.h

 
 /// @brief Simpler version for clients that don't want an open file.
 std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
                                     SmallVectorImpl<char> &ResultPath);
 
 std::error_code createUniqueDirectory(const Twine &Prefix,
                                       SmallVectorImpl<char> &ResultPath);
 
-/// @brief Fetch a path to an open file, as specified by a file descriptor
-///
-/// @param FD File descriptor to a currently open file
-/// @param ResultPath The buffer into which to write the path
-std::error_code getPathFromOpenFD(int FD, SmallVectorImpl<char> &ResultPath);
-
 enum OpenFlags : unsigned {
   F_None = 0,
 
   /// F_Excl - When opening a file, this flag makes raw_fd_ostream
   /// report an error if the file already exists.
   F_Excl = 1,
 
   /// F_Append - When opening a file, if it already exists append to the

llvm/lib/Support/Unix/Path.inc

 #ifndef O_CLOEXEC
   int r = fcntl(ResultFD, F_SETFD, FD_CLOEXEC);
   (void)r;
   assert(r == 0 && "fcntl(F_SETFD, FD_CLOEXEC) failed");
 #endif
   return std::error_code();
 }
 
-std::error_code getPathFromOpenFD(int FD, SmallVectorImpl<char> &ResultPath) {
-  if (FD < 0)
-    return make_error_code(errc::bad_file_descriptor);
-
-#if defined(F_GETPATH)
-  // When F_GETPATH is availble, it is the quickest way to get
-  // the path from a file descriptor.
-  ResultPath.reserve(MAXPATHLEN);
-  if (::fcntl(FD, F_GETPATH, ResultPath.begin()) == -1)
-    return std::error_code(errno, std::generic_category());
-
-  ResultPath.set_size(strlen(ResultPath.begin()));
-#else
-  // If we have a /proc filesystem mounted, we can quickly establish the
-  // real name of the file with readlink. Otherwise, we don't know how to
-  // get the filename from a file descriptor. Give up.
-  if (!fs::hasProcSelfFD())
-    return make_error_code(errc::function_not_supported);
-
-  ResultPath.reserve(PATH_MAX);
-  char ProcPath[64];
-  snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", FD);
-  ssize_t CharCount = ::readlink(ProcPath, ResultPath.begin(), ResultPath.capacity());
-  if (CharCount < 0)
-      return std::error_code(errno, std::generic_category());
-
-  // Was the filename truncated?
-  if (static_cast<size_t>(CharCount) == ResultPath.capacity()) {
-    // Use lstat to get the size of the filename
-    struct stat sb;
-    if (::lstat(ProcPath, &sb) < 0)
-      return std::error_code(errno, std::generic_category());
-
-    ResultPath.reserve(sb.st_size + 1);
-    CharCount = ::readlink(ProcPath, ResultPath.begin(), ResultPath.capacity());
-    if (CharCount < 0)
-      return std::error_code(errno, std::generic_category());
-
-    // Test for race condition: did the link size change?
-    if (CharCount > sb.st_size)
-      return std::error_code(ENAMETOOLONG, std::generic_category());
-  }
-  ResultPath.set_size(static_cast<size_t>(CharCount));
-#endif
-  return std::error_code();
-}
-
 template <typename T>
 static std::error_code remove_directories_impl(const T &Entry,
                                                bool IgnoreErrors) {
   std::error_code EC;
   directory_iterator Begin(Entry, EC, false);
   directory_iterator End;
   while (Begin != End) {
     auto &Item = *Begin;

llvm/lib/Support/Windows/Path.inc

if (FD == -1) {
     ::CloseHandle(H);
     return mapWindowsError(ERROR_INVALID_HANDLE);
   }
 
   ResultFD = FD;
   return std::error_code();
 }
 
-std::error_code getPathFromOpenFD(int FD, SmallVectorImpl<char> &ResultPath) {
-  HANDLE FileHandle = reinterpret_cast<HANDLE>(::_get_osfhandle(FD));
-  if (FileHandle == INVALID_HANDLE_VALUE)
-    return make_error_code(errc::bad_file_descriptor);
-
-  DWORD CharCount;
-  SmallVector<wchar_t, 1024> TempPath;
-  do {
-    CharCount = ::GetFinalPathNameByHandleW(FileHandle, TempPath.begin(),
-                                            TempPath.capacity(),
-                                            FILE_NAME_NORMALIZED);
-    if (CharCount < TempPath.capacity())
-      break;
-
-    // Reserve sufficient space for the path as well as the null character. Even
-    // though the API does not document that it is required, if we reserve just
-    // CharCount space, the function call will not store the resulting path and
-    // still report success.
-    TempPath.reserve(CharCount + 1);
-  } while (true);
-
-  if (CharCount == 0)
-    return mapWindowsError(::GetLastError());
-
-  TempPath.set_size(CharCount);
-
-  // On earlier Windows releases, the character count includes the terminating
-  // null.
-  if (TempPath.back() == L'\0') {
-    --CharCount;
-    TempPath.pop_back();
-  }
-
-  return windows::UTF16ToUTF8(TempPath.data(), CharCount, ResultPath);
-}
-
 std::error_code remove_directories(const Twine &path, bool IgnoreErrors) {
   // Convert to utf-16.
   SmallVector<wchar_t, 128> Path16;
   std::error_code EC = widenPath(path, Path16);
   if (EC && !IgnoreErrors)
     return EC;
 
   // SHFileOperation() accepts a list of paths, and so must be double null-

llvm/unittests/Support/Path.cpp

TEST(Support, ReplacePathPrefix) {
   Path = Path1;
   path::replace_path_prefix(Path, EmptyPrefix, NewPrefix);
   EXPECT_EQ(Path, "/new/foo");
   Path = Path2;
   path::replace_path_prefix(Path, OldPrefix, EmptyPrefix);
   EXPECT_EQ(Path, "/foo");
 }
 
-TEST_F(FileSystemTest, PathFromFD) {
-  // Create a temp file.
-  int FileDescriptor;
-  SmallString<64> TempPath;
-  ASSERT_NO_ERROR(
-      fs::createTemporaryFile("prefix", "temp", FileDescriptor, TempPath));
-  FileRemover Cleanup(TempPath);
-
-  // Make sure it exists.
-  ASSERT_TRUE(sys::fs::exists(Twine(TempPath)));
-
-  // Try to get the path from the file descriptor
-  SmallString<64> ResultPath;
-  std::error_code ErrorCode =
-      fs::getPathFromOpenFD(FileDescriptor, ResultPath);
-
-  // If we succeeded, check that the paths are the same (modulo case):
-  if (!ErrorCode) {
-    // The paths returned by createTemporaryFile and getPathFromOpenFD
-    // should reference the same file on disk.
-    fs::UniqueID D1, D2;
-    ASSERT_NO_ERROR(fs::getUniqueID(Twine(TempPath), D1));
-    ASSERT_NO_ERROR(fs::getUniqueID(Twine(ResultPath), D2));
-    ASSERT_EQ(D1, D2);
-  }
-
-  ::close(FileDescriptor);
-}
-
-TEST_F(FileSystemTest, PathFromFDWin32) {
-  // Create a temp file.
-  int FileDescriptor;
-  SmallString<64> TempPath;
-  ASSERT_NO_ERROR(
-    fs::createTemporaryFile("prefix", "temp", FileDescriptor, TempPath));
-  FileRemover Cleanup(TempPath);
-
-  // Make sure it exists.
-  ASSERT_TRUE(sys::fs::exists(Twine(TempPath)));
-  
-  SmallVector<char, 8> ResultPath;
-  std::error_code ErrorCode =
-    fs::getPathFromOpenFD(FileDescriptor, ResultPath);
-
-  if (!ErrorCode) {
-    // Now that we know how much space is required for the path, create a path
-    // buffer with exactly enough space (sans null terminator, which should not
-    // be present), and call getPathFromOpenFD again to ensure that the API
-    // properly handles exactly-sized buffers.
-    SmallVector<char, 8> ExactSizedPath(ResultPath.size());
-    ErrorCode = fs::getPathFromOpenFD(FileDescriptor, ExactSizedPath);
-    ResultPath = ExactSizedPath;
-  }
-
-  if (!ErrorCode) {
-    fs::UniqueID D1, D2;
-    ASSERT_NO_ERROR(fs::getUniqueID(Twine(TempPath), D1));
-    ASSERT_NO_ERROR(fs::getUniqueID(Twine(ResultPath), D2));
-    ASSERT_EQ(D1, D2);
-  }
-  ::close(FileDescriptor);
-}
-
-TEST_F(FileSystemTest, PathFromFDUnicode) {
-  // Create a temp file.
-  int FileDescriptor;
-  SmallString<64> TempPath;
-
-  // Test Unicode: "<temp directory>/(pi)r^2<temp rand chars>.aleth.0"
-  ASSERT_NO_ERROR(
-    fs::createTemporaryFile("\xCF\x80r\xC2\xB2",
-                            "\xE2\x84\xB5.0", FileDescriptor, TempPath));
-  FileRemover Cleanup(TempPath);
-
-  // Make sure it exists.
-  ASSERT_TRUE(sys::fs::exists(Twine(TempPath)));
-
-  SmallVector<char, 8> ResultPath;
-  std::error_code ErrorCode =
-    fs::getPathFromOpenFD(FileDescriptor, ResultPath);
-
-  if (!ErrorCode) {
-    fs::UniqueID D1, D2;
-    ASSERT_NO_ERROR(fs::getUniqueID(Twine(TempPath), D1));
-    ASSERT_NO_ERROR(fs::getUniqueID(Twine(ResultPath), D2));
-    ASSERT_EQ(D1, D2);
-  }
-  ::close(FileDescriptor);
-}
-
 TEST_F(FileSystemTest, OpenFileForRead) {
   // Create a temp file.
   int FileDescriptor;
   SmallString<64> TempPath;
   ASSERT_NO_ERROR(
       fs::createTemporaryFile("prefix", "temp", FileDescriptor, TempPath));
   FileRemover Cleanup(TempPath);