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.unpack200.bytecode; 020 021import java.io.DataOutputStream; 022import java.io.IOException; 023import java.util.Arrays; 024import java.util.List; 025 026import org.apache.commons.compress.harmony.pack200.Pack200Exception; 027 028/** 029 * Abstract superclass for attributes that have some part encoded with Byte Code Injection (BCI) renumbering. 030 */ 031public abstract class BCIRenumberedAttribute extends Attribute { 032 033 /** 034 * Whether renumbering has occurred. 035 */ 036 protected boolean renumbered; 037 038 /** 039 * Constructs a new instance for an attribute name. 040 * 041 * @param attributeName an attribute name. 042 */ 043 public BCIRenumberedAttribute(final CPUTF8 attributeName) { 044 super(attributeName); 045 } 046 047 @Override 048 protected abstract int getLength(); 049 050 /** 051 * Gets the array of indices for the start of line numbers. 052 * 053 * @return the array of indices for the start of line numbers. 054 */ 055 protected abstract int[] getStartPCs(); 056 057 /* 058 * (non-Javadoc) 059 * 060 * @see org.apache.commons.compress.harmony.unpack200.bytecode.Attribute#hasBCIRenumbering() 061 */ 062 @Override 063 public boolean hasBCIRenumbering() { 064 return true; 065 } 066 067 /** 068 * In Pack200, line number tables are BCI renumbered. This method takes the byteCodeOffsets (which is a List of Integers specifying the offset in the byte 069 * code array of each instruction) and updates the start_pcs so that it points to the instruction index itself, not the BCI renumbering of the instruction. 070 * 071 * @param byteCodeOffsets List of Integer offsets of the byte code array. 072 * @throws Pack200Exception Thrown from a subclass. 073 */ 074 public void renumber(final List<Integer> byteCodeOffsets) throws Pack200Exception { 075 if (renumbered) { 076 throw new Error("Trying to renumber a line number table that has already been renumbered"); 077 } 078 renumbered = true; 079 final int[] startPCs = getStartPCs(); 080 Arrays.setAll(startPCs, i -> byteCodeOffsets.get(startPCs[i]).intValue()); 081 } 082 083 @Override 084 public abstract String toString(); 085 086 @Override 087 protected abstract void writeBody(DataOutputStream dos) throws IOException; 088 089}