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 */ 017package org.apache.bcel.generic; 018 019import org.apache.bcel.Const; 020 021/** 022 * Returnaddress, the type JSR or JSR_W instructions push upon the stack. 023 * 024 * see vmspec2 �3.3.3 025 */ 026public class ReturnaddressType extends Type { 027 028 public static final ReturnaddressType NO_TARGET = new ReturnaddressType(); 029 private InstructionHandle returnTarget; 030 031 /** 032 * A Returnaddress [that doesn't know where to return to]. 033 */ 034 private ReturnaddressType() { 035 super(Const.T_ADDRESS, "<return address>"); 036 } 037 038 /** 039 * Creates a ReturnaddressType object with a target. 040 */ 041 public ReturnaddressType(final InstructionHandle returnTarget) { 042 super(Const.T_ADDRESS, "<return address targeting " + returnTarget + ">"); 043 this.returnTarget = returnTarget; 044 } 045 046 /** 047 * Returns if the two Returnaddresses refer to the same target. 048 */ 049 @Override 050 public boolean equals(final Object rat) { 051 if (!(rat instanceof ReturnaddressType)) { 052 return false; 053 } 054 final ReturnaddressType that = (ReturnaddressType) rat; 055 if (this.returnTarget == null || that.returnTarget == null) { 056 return that.returnTarget == this.returnTarget; 057 } 058 return that.returnTarget.equals(this.returnTarget); 059 } 060 061 /** 062 * @return the target of this ReturnaddressType 063 */ 064 public InstructionHandle getTarget() { 065 return returnTarget; 066 } 067 068 /** 069 * @return a hash code value for the object. 070 */ 071 @Override 072 public int hashCode() { 073 if (returnTarget == null) { 074 return 0; 075 } 076 return returnTarget.hashCode(); 077 } 078}