001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 *
017 */
018package org.apache.bcel.generic;
019
020/**
021 * Super class for stack operations like DUP and POP.
022 *
023 */
024public abstract class StackInstruction extends Instruction {
025
026    /**
027     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
028     */
029    StackInstruction() {
030    }
031
032    /**
033     * @param opcode instruction opcode
034     */
035    protected StackInstruction(final short opcode) {
036        super(opcode, (short) 1);
037    }
038
039    /**
040     * @return Type.UNKNOWN
041     */
042    public Type getType(final ConstantPoolGen cp) {
043        return Type.UNKNOWN;
044    }
045}