1 /* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 4 */ 5 package com.sun.org.apache.bcel.internal.generic; 6 7 /* ==================================================================== 8 * The Apache Software License, Version 1.1 9 * 10 * Copyright (c) 2001 The Apache Software Foundation. All rights 11 * reserved. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in 22 * the documentation and/or other materials provided with the 23 * distribution. 24 * 25 * 3. The end-user documentation included with the redistribution, 26 * if any, must include the following acknowledgment: 27 * "This product includes software developed by the 28 * Apache Software Foundation (http://www.apache.org/)." 29 * Alternately, this acknowledgment may appear in the software itself, 30 * if and wherever such third-party acknowledgments normally appear. 31 * 32 * 4. The names "Apache" and "Apache Software Foundation" and 33 * "Apache BCEL" must not be used to endorse or promote products 34 * derived from this software without prior written permission. For 35 * written permission, please contact apache@apache.org. 36 * 37 * 5. Products derived from this software may not be called "Apache", 38 * "Apache BCEL", nor may "Apache" appear in their name, without 39 * prior written permission of the Apache Software Foundation. 40 * 41 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 42 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 43 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 44 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 45 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 48 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 49 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 50 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 51 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 52 * SUCH DAMAGE. 53 * ==================================================================== 54 * 55 * This software consists of voluntary contributions made by many 56 * individuals on behalf of the Apache Software Foundation. For more 57 * information on the Apache Software Foundation, please see 58 * <http://www.apache.org/>. 59 */ 60 61 /** 62 * Equality of instructions isn't clearly to be defined. You might 63 * wish, for example, to compare whether instructions have the same 64 * meaning. E.g., whether two INVOKEVIRTUALs describe the same 65 * call.<br>The DEFAULT comparator however, considers two instructions 66 * to be equal if they have same opcode and point to the same indexes 67 * (if any) in the constant pool or the same local variable index. Branch 68 * instructions must have the same target. 69 * 70 * @see Instruction 71 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> 72 */ 73 public interface InstructionComparator { 74 public static final InstructionComparator DEFAULT = 75 new InstructionComparator() { 76 public boolean equals(Instruction i1, Instruction i2) { 77 if(i1.opcode == i2.opcode) { 78 if(i1 instanceof Select) { 79 InstructionHandle[] t1 = ((Select)i1).getTargets(); 80 InstructionHandle[] t2 = ((Select)i2).getTargets(); 81 82 if(t1.length == t2.length) { 83 for(int i = 0; i < t1.length; i++) { 84 if(t1[i] != t2[i]) { 85 return false; 86 } 87 } 88 89 return true; 90 } 91 } else if(i1 instanceof BranchInstruction) { 92 return ((BranchInstruction)i1).target == 93 ((BranchInstruction)i2).target; 94 } else if(i1 instanceof ConstantPushInstruction) { 95 return ((ConstantPushInstruction)i1).getValue(). 96 equals(((ConstantPushInstruction)i2).getValue()); 97 } else if(i1 instanceof IndexedInstruction) { 98 return ((IndexedInstruction)i1).getIndex() == 99 ((IndexedInstruction)i2).getIndex(); 100 } else if(i1 instanceof NEWARRAY) { 101 return ((NEWARRAY)i1).getTypecode() == ((NEWARRAY)i2).getTypecode(); 102 } else { 103 return true; 104 } 105 } 106 107 return false; 108 } 109 }; 110 111 public boolean equals(Instruction i1, Instruction i2); 112 }