// This is an interface for the compiler that allows accessing non-resolved entries
// in the constant pool - but still performs the validations tests. Must be used
// in a pre-parse of the compiler - to determine what it can do and not do.
// Note: We cannot update the ConstantPool from the vm_thread.

klassOop constantPoolOopDesc::klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int index, TRAPS) {

  {- -------------------------------------------
  (1) constantPoolOopDesc::klass_ref_index_at() を呼んで
      class_index と name_and_type index からなる constant pool 情報から
      class_index 部分のみを取得する.
      ---------------------------------------- -}

      int which = this_oop->klass_ref_index_at(index);

  {- -------------------------------------------
  (1) 取得した index に対応する klassOop を取得しリターンする.

      (対象クラスが constantPoolOopDesc 中でまだ解決されてなくても
      解決が実行されないよう
      constantPoolOopDesc::klass_at() ではなく自前で klassOop を探している 
      (未だ解決されてない場合は SystemDictionary::find() で取得))
      ---------------------------------------- -}

      CPSlot entry = this_oop->slot_at(which);
      if (entry.is_oop()) {
        assert(entry.get_oop()->is_klass(), "must be");
        return (klassOop)entry.get_oop();
      } else {
        assert(entry.is_metadata(), "must be either symbol or klass");
        Symbol*  name  = entry.get_symbol();
        oop loader = instanceKlass::cast(this_oop->pool_holder())->class_loader();
        oop protection_domain = Klass::cast(this_oop->pool_holder())->protection_domain();
        Handle h_loader(THREAD, loader);
        Handle h_prot  (THREAD, protection_domain);
        KlassHandle k(THREAD, SystemDictionary::find(name, h_loader, h_prot, THREAD));

        // Do access check for klasses
        if( k.not_null() ) verify_constant_pool_resolve(this_oop, k, CHECK_NULL);
        return k();
      }
    }