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.bcel.generic; 020 021/** 022 * Equality of instructions isn't clearly to be defined. You might wish, for example, to compare whether instructions 023 * have the same meaning. E.g., whether two INVOKEVIRTUALs describe the same call. 024 * <p> 025 * The DEFAULT comparator however, considers two instructions to be equal if they have same opcode and point to the same 026 * indexes (if any) in the constant pool or the same local variable index. Branch instructions must have the same 027 * target. 028 * </p> 029 * 030 * @see Instruction 031 */ 032public interface InstructionComparator { 033 034 InstructionComparator DEFAULT = (i1, i2) -> { 035 if (i1.getOpcode() == i2.getOpcode()) { 036 if (i1 instanceof BranchInstruction) { 037 // BIs are never equal to make targeters work correctly (BCEL-195) 038 return false; 039// } else if (i1 == i2) { TODO consider adding this shortcut 040// return true; // this must be AFTER the BI test 041 } 042 if (i1 instanceof ConstantPushInstruction) { 043 return ((ConstantPushInstruction) i1).getValue().equals(((ConstantPushInstruction) i2).getValue()); 044 } 045 if (i1 instanceof IndexedInstruction) { 046 return ((IndexedInstruction) i1).getIndex() == ((IndexedInstruction) i2).getIndex(); 047 } 048 if (i1 instanceof NEWARRAY) { 049 return ((NEWARRAY) i1).getTypecode() == ((NEWARRAY) i2).getTypecode(); 050 } 051 return true; 052 } 053 return false; 054 }; 055 056 boolean equals(Instruction i1, Instruction i2); 057}