Function createUniqueEntity

ext/src/llvm/Path.cpp:167–218

};

static std::error_code
createUniqueEntity(const Twine &Model, int &ResultFD,
                   SmallVectorImpl<char> &ResultPath, bool MakeAbsolute,
                   unsigned Mode, FSEntity Type,
                   sys::fs::OpenFlags Flags = sys::fs::OF_None) {

  // Limit the number of attempts we make, so that we don't infinite loop. E.g.
  // "permission denied" could be for a specific file (so we retry with a
  // different name) or for the whole directory (retry would always fail).
  // Checking which is racy, so we try a number of times, then give up.
  std::error_code EC;
  for (int Retries = 128; Retries > 0; --Retries) {
    sys::fs::createUniquePath(Model, ResultPath, MakeAbsolute);
    // Try to open + create the file.
    switch (Type) {
    case FS_File: {
      EC = sys::fs::openFileForReadWrite(Twine(ResultPath.begin()), ResultFD,
                                         sys::fs::CD_CreateNew, Flags, Mode);
      if (EC) {
        // errc::permission_denied happens on Windows when we try to open a file
        // that has been marked for deletion.
        if (EC == errc::file_exists || EC == errc::permission_denied)
          continue;
        return EC;
      }

      return std::error_code();
    }

    case FS_Name: {
      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;
      continue;
    }

    case FS_Dir: {
      EC = sys::fs::create_directory(ResultPath.begin(), false);
      if (EC) {
        if (EC == errc::file_exists)
          continue;
        return EC;
      }
      return std::error_code();
    }
    }
    llvm_unreachable("Invalid Type");
  }
  return EC;
}

namespace llvm {
namespace sys  {