context_.cpp_config.unit + "_ops.h");
  string with_underscores(self_path);
  std::replace(with_underscores.begin(), with_underscores.end(), '/', '_');
  std::replace(with_underscores.begin(), with_underscores.end(), '.', '_');
  guard_ = toUpperSnake(with_underscores) + "_";
}

void GuardRenderer::Open() {
  CodeLine("#ifndef $0", guard_);
  CodeLine("#define $0", guard_);