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 */
017package org.apache.bcel.generic;
018
019/**
020 * DCONST - Push 0.0 or 1.0, other values cause an exception
021 *
022 * <PRE>
023 * Stack: ... -&gt; ...,
024 * </PRE>
025 */
026public class DCONST extends Instruction implements ConstantPushInstruction {
027
028    private final double value;
029
030    /**
031     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
032     */
033    DCONST() {
034        this(0);
035    }
036
037    public DCONST(final double f) {
038        super(org.apache.bcel.Const.DCONST_0, (short) 1);
039        if (f == 0.0) {
040            super.setOpcode(org.apache.bcel.Const.DCONST_0);
041        } else if (f == 1.0) {
042            super.setOpcode(org.apache.bcel.Const.DCONST_1);
043        } else {
044            throw new ClassGenException("DCONST can be used only for 0.0 and 1.0: " + f);
045        }
046        value = f;
047    }
048
049    /**
050     * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
051     * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last.
052     *
053     * @param v Visitor object
054     */
055    @Override
056    public void accept(final Visitor v) {
057        v.visitPushInstruction(this);
058        v.visitStackProducer(this);
059        v.visitTypedInstruction(this);
060        v.visitConstantPushInstruction(this);
061        v.visitDCONST(this);
062    }
063
064    /**
065     * @return Type.DOUBLE
066     */
067    @Override
068    public Type getType(final ConstantPoolGen cp) {
069        return Type.DOUBLE;
070    }
071
072    @Override
073    public Number getValue() {
074        return Double.valueOf(value);
075    }
076}