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 * 017 */ 018package org.apache.bcel.generic; 019 020import java.io.DataOutputStream; 021import java.io.IOException; 022 023import org.apache.bcel.classfile.Constant; 024import org.apache.bcel.classfile.ConstantClass; 025import org.apache.bcel.classfile.ConstantPool; 026import org.apache.bcel.util.ByteSequence; 027 028/** 029 * Abstract super class for instructions that use an index into the 030 * constant pool such as LDC, INVOKEVIRTUAL, etc. 031 * 032 * @see ConstantPoolGen 033 * @see LDC 034 * @see INVOKEVIRTUAL 035 * 036 */ 037public abstract class CPInstruction extends Instruction implements TypedInstruction, 038 IndexedInstruction { 039 040 /** 041 * @deprecated (since 6.0) will be made private; do not access directly, use getter/setter 042 */ 043 @Deprecated 044 protected int index; // index to constant pool 045 046 047 /** 048 * Empty constructor needed for Instruction.readInstruction. 049 * Not to be used otherwise. 050 */ 051 CPInstruction() { 052 } 053 054 055 /** 056 * @param index to constant pool 057 */ 058 protected CPInstruction(final short opcode, final int index) { 059 super(opcode, (short) 3); 060 setIndex(index); 061 } 062 063 064 /** 065 * Dump instruction as byte code to stream out. 066 * @param out Output stream 067 */ 068 @Override 069 public void dump( final DataOutputStream out ) throws IOException { 070 out.writeByte(super.getOpcode()); 071 out.writeShort(index); 072 } 073 074 075 /** 076 * Long output format: 077 * 078 * <name of opcode> "["<opcode number>"]" 079 * "("<length of instruction>")" "<"< constant pool index>">" 080 * 081 * @param verbose long/short format switch 082 * @return mnemonic for instruction 083 */ 084 @Override 085 public String toString( final boolean verbose ) { 086 return super.toString(verbose) + " " + index; 087 } 088 089 090 /** 091 * @return mnemonic for instruction with symbolic references resolved 092 */ 093 @Override 094 public String toString( final ConstantPool cp ) { 095 final Constant c = cp.getConstant(index); 096 String str = cp.constantToString(c); 097 if (c instanceof ConstantClass) { 098 str = str.replace('.', '/'); 099 } 100 return org.apache.bcel.Const.getOpcodeName(super.getOpcode()) + " " + str; 101 } 102 103 104 /** 105 * Read needed data (i.e., index) from file. 106 * @param bytes input stream 107 * @param wide wide prefix? 108 */ 109 @Override 110 protected void initFromFile( final ByteSequence bytes, final boolean wide ) throws IOException { 111 setIndex(bytes.readUnsignedShort()); 112 super.setLength(3); 113 } 114 115 116 /** 117 * @return index in constant pool referred by this instruction. 118 */ 119 @Override 120 public final int getIndex() { 121 return index; 122 } 123 124 125 /** 126 * Set the index to constant pool. 127 * @param index in constant pool. 128 */ 129 @Override 130 public void setIndex( final int index ) { // TODO could be package-protected? 131 if (index < 0) { 132 throw new ClassGenException("Negative index value: " + index); 133 } 134 this.index = index; 135 } 136 137 138 /** @return type related with this instruction. 139 */ 140 @Override 141 public Type getType( final ConstantPoolGen cpg ) { 142 final ConstantPool cp = cpg.getConstantPool(); 143 String name = cp.getConstantString(index, org.apache.bcel.Const.CONSTANT_Class); 144 if (!name.startsWith("[")) { 145 name = "L" + name + ";"; 146 } 147 return Type.getType(name); 148 } 149}