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; 019 020/** 021 * Equality of instructions isn't clearly to be defined. You might wish, for example, to compare whether instructions 022 * have the same meaning. E.g., whether two INVOKEVIRTUALs describe the same call. 023 * <p> 024 * The DEFAULT comparator however, considers two instructions to be equal if they have same opcode and point to the same 025 * indexes (if any) in the constant pool or the same local variable index. Branch instructions must have the same 026 * target. 027 * </p> 028 * 029 * @see Instruction 030 */ 031public interface InstructionComparator { 032 033 InstructionComparator DEFAULT = (i1, i2) -> { 034 if (i1.getOpcode() == i2.getOpcode()) { 035 if (i1 instanceof BranchInstruction) { 036 // BIs are never equal to make targeters work correctly (BCEL-195) 037 return false; 038// } else if (i1 == i2) { TODO consider adding this shortcut 039// return true; // this must be AFTER the BI test 040 } 041 if (i1 instanceof ConstantPushInstruction) { 042 return ((ConstantPushInstruction) i1).getValue().equals(((ConstantPushInstruction) i2).getValue()); 043 } 044 if (i1 instanceof IndexedInstruction) { 045 return ((IndexedInstruction) i1).getIndex() == ((IndexedInstruction) i2).getIndex(); 046 } 047 if (i1 instanceof NEWARRAY) { 048 return ((NEWARRAY) i1).getTypecode() == ((NEWARRAY) i2).getTypecode(); 049 } 050 return true; 051 } 052 return false; 053 }; 054 055 boolean equals(Instruction i1, Instruction i2); 056}