View Javadoc
1 package org.apache.bcel.generic; 2 3 /* ==================================================================== 4 * The Apache Software License, Version 1.1 5 * 6 * Copyright (c) 2001 The Apache Software Foundation. All rights 7 * reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. The end-user documentation included with the redistribution, 22 * if any, must include the following acknowledgment: 23 * "This product includes software developed by the 24 * Apache Software Foundation (http://www.apache.org/)." 25 * Alternately, this acknowledgment may appear in the software itself, 26 * if and wherever such third-party acknowledgments normally appear. 27 * 28 * 4. The names "Apache" and "Apache Software Foundation" and 29 * "Apache BCEL" must not be used to endorse or promote products 30 * derived from this software without prior written permission. For 31 * written permission, please contact apache@apache.org. 32 * 33 * 5. Products derived from this software may not be called "Apache", 34 * "Apache BCEL", nor may "Apache" appear in their name, without 35 * prior written permission of the Apache Software Foundation. 36 * 37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 40 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 43 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 44 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 45 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 46 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 47 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 48 * SUCH DAMAGE. 49 * ==================================================================== 50 * 51 * This software consists of voluntary contributions made by many 52 * individuals on behalf of the Apache Software Foundation. For more 53 * information on the Apache Software Foundation, please see 54 * <http://www.apache.org/>;. 55 */ 56 import java.io.*; 57 import org.apache.bcel.util.ByteSequence; 58 59 /*** 60 * RET - Return from subroutine 61 * 62 * <PRE>Stack: ..., -> ..., address</PRE> 63 * 64 * @version $Id: RET.java,v 1.1.1.1 2001/10/29 20:00:25 jvanzyl Exp $ 65 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> 66 */ 67 public class RET extends Instruction implements IndexedInstruction, TypedInstruction { 68 private boolean wide; 69 private int index; // index to local variable containg the return address 70 71 /*** 72 * Empty constructor needed for the Class.newInstance() statement in 73 * Instruction.readInstruction(). Not to be used otherwise. 74 */ 75 RET() {} 76 77 public RET(int index) { 78 super(org.apache.bcel.Constants.RET, (short)2); 79 setIndex(index); // May set wide as side effect 80 } 81 82 /*** 83 * Dump instruction as byte code to stream out. 84 * @param out Output stream 85 */ 86 public void dump(DataOutputStream out) throws IOException { 87 if(wide) 88 out.writeByte(org.apache.bcel.Constants.WIDE); 89 90 out.writeByte(opcode); 91 92 if(wide) 93 out.writeShort(index); 94 else 95 out.writeByte(index); 96 } 97 98 private final void setWide() { 99 if(wide = index > org.apache.bcel.Constants.MAX_BYTE) 100 length = 4; // Including the wide byte 101 else 102 length = 2; 103 } 104 105 /*** 106 * Read needed data (e.g. index) from file. 107 */ 108 protected void initFromFile(ByteSequence bytes, boolean wide) throws IOException 109 { 110 this.wide = wide; 111 112 if(wide) { 113 index = bytes.readUnsignedShort(); 114 length = 4; 115 } else { 116 index = bytes.readUnsignedByte(); 117 length = 2; 118 } 119 } 120 121 /*** 122 * @return index of local variable containg the return address 123 */ 124 public final int getIndex() { return index; } 125 126 /*** 127 * Set index of local variable containg the return address 128 */ 129 public final void setIndex(int n) { 130 if(n < 0) 131 throw new ClassGenException("Negative index value: " + n); 132 133 index = n; 134 setWide(); 135 } 136 137 /*** 138 * @return mnemonic for instruction 139 */ 140 public String toString(boolean verbose) { 141 return super.toString(verbose) + " " + index; 142 } 143 144 /*** @return return address type 145 */ 146 public Type getType(ConstantPoolGen cp) { 147 return ReturnaddressType.NO_TARGET; 148 } 149 150 /*** 151 * Call corresponding visitor method(s). The order is: 152 * Call visitor methods of implemented interfaces first, then 153 * call methods according to the class hierarchy in descending order, 154 * i.e., the most specific visitXXX() call comes last. 155 * 156 * @param v Visitor object 157 */ 158 public void accept(Visitor v) { 159 v.visitRET(this); 160 } 161 }

This page was automatically generated by Maven