I find a strange things. I find there is variable called

FLAGS_allow_unsafe

in

filesystem.cpp

,but I can't find where it is defined.I have searched the whole project but still can't find it.does anybody konw?here is the code.

bool safePermissions(const fs::path& dir,
                     const fs::path& path,
                     bool executable) {
  if (!platformIsFileAccessible(path).ok()) {
    // Path was not real, had too may links, or could not be accessed.
    return false;
  }

  if (FLAGS_allow_unsafe) {
    return true;
  }

  Status result = platformIsTmpDir(dir);
  if (!result.ok() && result.getCode() < 0) {
    // An error has occurred in stat() on dir, most likely because the file path
    // does not exist
    return false;
  } else if (result.ok()) {
    // Do not load modules from /tmp-like directories.
    return false;
  }
......