001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.bcel.generic;
020
021/**
022 * Super class for stack operations like DUP and POP.
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}