virtual void do_object(oop obj) {

  {- -------------------------------------------
  (1) oop 引数がクラスオブジェクトであれば, 
      java_lang_Class::fixup_mirror() を呼んで mirror を生成する.

      (なお, クラスオブジェクトでない場合は何もしない)
      ---------------------------------------- -}

        if (obj->is_klass()) {
          EXCEPTION_MARK;
          KlassHandle k(THREAD, klassOop(obj));
          // We will never reach the CATCH below since Exceptions::_throw will cause
          // the VM to exit if an exception is thrown during initialization
          java_lang_Class::fixup_mirror(k, CATCH);
          // This call unconditionally creates a new mirror for k,
          // and links in k's component_mirror field if k is an array.
          // If k is an objArray, k's element type must already have
          // a mirror.  In other words, this closure must process
          // the component type of an objArray k before it processes k.
          // This works because the permgen iterator presents arrays
          // and their component types in order of creation.
        }
      }