    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.commons.compress.harmony.pack200;
    018
    019import org.objectweb.asm.ClassReader;
    020
    021/**
    022 * Wrapper for ClassReader that enables pack200 to obtain extra class file information
    023 */
    024public class Pack200ClassReader extends ClassReader {
    025
    026    private boolean lastConstantHadWideIndex;
    027    private int lastUnsignedShort;
    028    private boolean anySyntheticAttributes;
    029    private String fileName;
    030
    031    /**
    032     * @param b the contents of class file in the format of bytes
    033     */
    034    public Pack200ClassReader(final byte[] b) {
    035        super(b);
    036    }
    037
    038    public String getFileName() {
    039        return fileName;
    040    }
    041
    042    public boolean hasSyntheticAttributes() {
    043        return anySyntheticAttributes;
    044    }
    045
    046    public boolean lastConstantHadWideIndex() {
    047        return lastConstantHadWideIndex;
    048    }
    049
    050    @Override
    051    public Object readConst(final int item, final char[] buf) {
    052        lastConstantHadWideIndex = item == lastUnsignedShort;
    053        return super.readConst(item, buf);
    054    }
    055
    056    @Override
    057    public int readUnsignedShort(final int index) {
    058        // Doing this to check whether last load-constant instruction was ldc (18) or ldc_w (19)
    059        // TODO: Assess whether this impacts on performance
    060        final int unsignedShort = super.readUnsignedShort(index);
    061        if (index > 0 && b[index - 1] == 19) {
    062            lastUnsignedShort = unsignedShort;
    063        } else {
    064            lastUnsignedShort = Short.MIN_VALUE;
    065        }
    066        return unsignedShort;
    067    }
    068
    069    @Override
    070    public String readUTF8(final int arg0, final char[] arg1) {
    071        final String utf8 = super.readUTF8(arg0, arg1);
    072        if (!anySyntheticAttributes && "Synthetic".equals(utf8)) {
    073            anySyntheticAttributes = true;
    074        }
    075        return utf8;
    076    }
    077
    078    public void setFileName(final String name) {
    079        this.fileName = name;
    080    }
    081
    082}