// finds the byte code path root (dir or jar)
// TODO: inner classes will not be found (need to replace . with $)
static File byteCodePathForClass(Class c) {
  if (c == null) null;
  ClassLoader cl = getClassLoader(c);
  
  // handle JavaXClassLoader
  Cl<File> files = cast getOpt(cl, 'files);
  if (files != null) {
    S name = c.getName().replace('.', '/') + ".class";
    for (File location : files) 
      if (dirOrZipContainsPath(location, name))
        ret location;
    fail(name + " not found in: " + files);
  }
  
  null;
}

static File byteCodePathForClass(O o) {
  ret byteCodePathForClass(_getClass(o));
}