Source code

    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}