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
019import java.io.DataOutputStream;
020import java.io.IOException;
021
022import org.apache.bcel.util.ByteSequence;
023
024/**
025 * TABLESWITCH - Switch within given range of values, i.e., low..high
026 *
027 * @see SWITCH
028 */
029public class TABLESWITCH extends Select {
030
031    /**
032     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
033     */
034    TABLESWITCH() {
035    }
036
037    /**
038     * @param match sorted array of match values, match[0] must be low value, match[match_length - 1] high value
039     * @param targets where to branch for matched values
040     * @param defaultTarget default branch
041     */
042    public TABLESWITCH(final int[] match, final InstructionHandle[] targets, final InstructionHandle defaultTarget) {
043        super(org.apache.bcel.Const.TABLESWITCH, match, targets, defaultTarget);
044        /* Alignment remainder assumed 0 here, until dump time */
045        final short length = (short) (13 + getMatchLength() * 4);
046        super.setLength(length);
047        setFixedLength(length);
048    }
049
050    /**
051     * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
052     * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last.
053     *
054     * @param v Visitor object
055     */
056    @Override
057    public void accept(final Visitor v) {
058        v.visitVariableLengthInstruction(this);
059        v.visitStackConsumer(this);
060        v.visitBranchInstruction(this);
061        v.visitSelect(this);
062        v.visitTABLESWITCH(this);
063    }
064
065    /**
066     * Dump instruction as byte code to stream out.
067     *
068     * @param out Output stream
069     */
070    @Override
071    public void dump(final DataOutputStream out) throws IOException {
072        super.dump(out);
073        final int matchLength = getMatchLength();
074        final int low = matchLength > 0 ? super.getMatch(0) : 0;
075        out.writeInt(low);
076        final int high = matchLength > 0 ? super.getMatch(matchLength - 1) : 0;
077        out.writeInt(high);
078        for (int i = 0; i < matchLength; i++) {
079            out.writeInt(setIndices(i, getTargetOffset(super.getTarget(i))));
080        }
081    }
082
083    /**
084     * Read needed data (e.g. index) from file.
085     */
086    @Override
087    protected void initFromFile(final ByteSequence bytes, final boolean wide) throws IOException {
088        super.initFromFile(bytes, wide);
089        final int low = bytes.readInt();
090        final int high = bytes.readInt();
091        final int matchLength = high - low + 1;
092        setMatchLength(matchLength);
093        final short fixedLength = (short) (13 + matchLength * 4);
094        setFixedLength(fixedLength);
095        super.setLength((short) (fixedLength + super.getPadding()));
096        super.setMatches(new int[matchLength]);
097        super.setIndices(new int[matchLength]);
098        super.setTargets(new InstructionHandle[matchLength]);
099        for (int i = 0; i < matchLength; i++) {
100            super.setMatch(i, low + i);
101            super.setIndices(i, bytes.readInt());
102        }
103    }
104}