op(FIRST, (x, y -- a, b)) {
            a = x;
            b = y;
        }

        op(SECOND, (a, b -- a, b)) {
        }

        op(THIRD, (j, k --)) {
            ERROR_IF(cond, error);
        }

        macro(TEST) = FIRST + SECOND + THIRD;
        """

     ...
     if (cond) goto pop_4_error;
     ...