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.unpack200.bytecode; 018 019import java.io.DataOutputStream; 020import java.io.IOException; 021import java.util.List; 022 023import org.apache.commons.compress.harmony.pack200.Pack200Exception; 024 025/** 026 * Abstract superclass for attributes that have some part encoded with a BCI renumbering 027 */ 028public abstract class BCIRenumberedAttribute extends Attribute { 029 030 protected boolean renumbered; 031 032 /* 033 * (non-Javadoc) 034 * 035 * @see org.apache.commons.compress.harmony.unpack200.bytecode.Attribute#hasBCIRenumbering() 036 */ 037 @Override 038 public boolean hasBCIRenumbering() { 039 return true; 040 } 041 042 public BCIRenumberedAttribute(final CPUTF8 attributeName) { 043 super(attributeName); 044 } 045 046 @Override 047 protected abstract int getLength(); 048 049 @Override 050 protected abstract void writeBody(DataOutputStream dos) throws IOException; 051 052 @Override 053 public abstract String toString(); 054 055 protected abstract int[] getStartPCs(); 056 057 /** 058 * In Pack200, line number tables are BCI renumbered. This method takes the byteCodeOffsets (which is a List of 059 * Integers specifying the offset in the byte code array of each instruction) and updates the start_pcs so that it 060 * points to the instruction index itself, not the BCI renumbering of the instruction. 061 * 062 * @param byteCodeOffsets List of Integer offsets of the bytecode array 063 * @throws Pack200Exception TODO 064 */ 065 public void renumber(final List byteCodeOffsets) throws Pack200Exception { 066 if (renumbered) { 067 throw new Error("Trying to renumber a line number table that has already been renumbered"); 068 } 069 renumbered = true; 070 final int[] startPCs = getStartPCs(); 071 for (int index = 0; index < startPCs.length; index++) { 072 startPCs[index] = ((Integer) byteCodeOffsets.get(startPCs[index])).intValue(); 073 } 074 } 075 076}