1 /* 2 * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved. 3 */ 4 /* 5 * Licensed to the Apache Software Foundation (ASF) under one or more 6 * contributor license agreements. See the NOTICE file distributed with 7 * this work for additional information regarding copyright ownership. 8 * The ASF licenses this file to You under the Apache License, Version 2.0 9 * (the "License"); you may not use this file except in compliance with 10 * the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, software 15 * distributed under the License is distributed on an "AS IS" BASIS, 16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 17 * See the License for the specific language governing permissions and 18 * limitations under the License. 19 */ 20 package com.sun.org.apache.bcel.internal.generic; 21 22 import java.io.DataOutputStream; 23 import java.io.IOException; 24 25 import com.sun.org.apache.bcel.internal.classfile.Constant; 26 import com.sun.org.apache.bcel.internal.classfile.ConstantClass; 27 import com.sun.org.apache.bcel.internal.classfile.ConstantPool; 28 import com.sun.org.apache.bcel.internal.util.ByteSequence; 29 30 /** 31 * Abstract super class for instructions that use an index into the 32 * constant pool such as LDC, INVOKEVIRTUAL, etc. 33 * 34 * @see ConstantPoolGen 35 * @see LDC 36 * @see INVOKEVIRTUAL 37 * 38 * @version $Id$ 39 * @LastModified: Jun 2019 40 */ 41 public abstract class CPInstruction extends Instruction implements TypedInstruction, 42 IndexedInstruction { 43 44 private int index; // index to constant pool 45 46 47 /** 48 * Empty constructor needed for Instruction.readInstruction. 49 * Not to be used otherwise. 50 */ 51 CPInstruction() { 52 } 53 54 55 /** 56 * @param index to constant pool 57 */ 58 protected CPInstruction(final short opcode, final int index) { 59 super(opcode, (short) 3); 60 setIndex(index); 61 } 62 63 64 /** 65 * Dump instruction as byte code to stream out. 66 * @param out Output stream 67 */ 68 @Override 69 public void dump( final DataOutputStream out ) throws IOException { 70 out.writeByte(super.getOpcode()); 71 out.writeShort(index); 72 } 73 74 75 /** 76 * Long output format: 77 * 78 * <name of opcode> "["<opcode number>"]" 79 * "("<length of instruction>")" "<"< constant pool index>">" 80 * 81 * @param verbose long/short format switch 82 * @return mnemonic for instruction 83 */ 84 @Override 85 public String toString( final boolean verbose ) { 86 return super.toString(verbose) + " " + index; 87 } 88 89 90 /** 91 * @return mnemonic for instruction with symbolic references resolved 92 */ 93 @Override 94 public String toString( final ConstantPool cp ) { 95 final Constant c = cp.getConstant(index); 96 String str = cp.constantToString(c); 97 if (c instanceof ConstantClass) { 98 str = str.replace('.', '/'); 99 } 100 return com.sun.org.apache.bcel.internal.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, com.sun.org.apache.bcel.internal.Const.CONSTANT_Class); 144 if (!name.startsWith("[")) { 145 name = "L" + name + ";"; 146 } 147 return Type.getType(name); 148 } 149 }