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 020import org.apache.bcel.Const; 021 022/** 023 * Returnaddress, the type JSR or JSR_W instructions push upon the stack. 024 * 025 * see vmspec2 �3.3.3 026 */ 027public class ReturnaddressType extends Type { 028 029 public static final ReturnaddressType NO_TARGET = new ReturnaddressType(); 030 private InstructionHandle returnTarget; 031 032 033 /** 034 * A Returnaddress [that doesn't know where to return to]. 035 */ 036 private ReturnaddressType() { 037 super(Const.T_ADDRESS, "<return address>"); 038 } 039 040 041 /** 042 * Creates a ReturnaddressType object with a target. 043 */ 044 public ReturnaddressType(final InstructionHandle returnTarget) { 045 super(Const.T_ADDRESS, "<return address targeting " + returnTarget + ">"); 046 this.returnTarget = returnTarget; 047 } 048 049 050 /** @return a hash code value for the object. 051 */ 052 @Override 053 public int hashCode() { 054 if (returnTarget == null) { 055 return 0; 056 } 057 return returnTarget.hashCode(); 058 } 059 060 061 /** 062 * Returns if the two Returnaddresses refer to the same target. 063 */ 064 @Override 065 public boolean equals( final Object rat ) { 066 if (!(rat instanceof ReturnaddressType)) { 067 return false; 068 } 069 final ReturnaddressType that = (ReturnaddressType) rat; 070 if (this.returnTarget == null || that.returnTarget == null) { 071 return that.returnTarget == this.returnTarget; 072 } 073 return that.returnTarget.equals(this.returnTarget); 074 } 075 076 077 /** 078 * @return the target of this ReturnaddressType 079 */ 080 public InstructionHandle getTarget() { 081 return returnTarget; 082 } 083}