klassOop instanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {

  {- -------------------------------------------
  (1) local_interfaces() の中を順に辿り, instanceKlass::find_local_field() と instanceKlass::find_interface_field() で調べていく.
      (まず instanceKlass::find_local_field() で調べ, ダメなら instanceKlass::find_interface_field() で再帰的に調べる.
       それでもダメなら次のインターフェースにうつる.)
      見つからなければ NULL をリターン.
      ---------------------------------------- -}

      const int n = local_interfaces()->length();
      for (int i = 0; i < n; i++) {
        klassOop intf1 = klassOop(local_interfaces()->obj_at(i));
        assert(Klass::cast(intf1)->is_interface(), "just checking type");
        // search for field in current interface
        if (instanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
          assert(fd->is_static(), "interface field must be static");
          return intf1;
        }
        // search for field in direct superinterfaces
        klassOop intf2 = instanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
        if (intf2 != NULL) return intf2;
      }
      // otherwise field lookup fails
      return NULL;
    }