    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.commons.compress.harmony.pack200;
    020
    021import org.objectweb.asm.ClassReader;
    022
    023/**
    024 * Wrapper for ClassReader that enables pack200 to obtain extra class file information
    025 */
    026public class Pack200ClassReader extends ClassReader {
    027
    028    private boolean lastConstantHadWideIndex;
    029    private int lastUnsignedShort;
    030    private boolean anySyntheticAttributes;
    031    private String fileName;
    032
    033    /**
    034     * @param b the contents of class file in the format of bytes
    035     */
    036    public Pack200ClassReader(final byte[] b) {
    037        super(b);
    038    }
    039
    040    public String getFileName() {
    041        return fileName;
    042    }
    043
    044    public boolean hasSyntheticAttributes() {
    045        return anySyntheticAttributes;
    046    }
    047
    048    public boolean lastConstantHadWideIndex() {
    049        return lastConstantHadWideIndex;
    050    }
    051
    052    @Override
    053    public Object readConst(final int item, final char[] buf) {
    054        lastConstantHadWideIndex = item == lastUnsignedShort;
    055        return super.readConst(item, buf);
    056    }
    057
    058    @Override
    059    public int readUnsignedShort(final int index) {
    060        // Doing this to check whether last load-constant instruction was ldc (18) or ldc_w (19)
    061        // TODO: Assess whether this impacts on performance
    062        final int unsignedShort = super.readUnsignedShort(index);
    063        if (index > 0 && b[index - 1] == 19) {
    064            lastUnsignedShort = unsignedShort;
    065        } else {
    066            lastUnsignedShort = Short.MIN_VALUE;
    067        }
    068        return unsignedShort;
    069    }
    070
    071    @Override
    072    public String readUTF8(final int arg0, final char[] arg1) {
    073        final String utf8 = super.readUTF8(arg0, arg1);
    074        if (!anySyntheticAttributes && "Synthetic".equals(utf8)) {
    075            anySyntheticAttributes = true;
    076        }
    077        return utf8;
    078    }
    079
    080    public void setFileName(final String name) {
    081        this.fileName = name;
    082    }
    083
    084}