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Java > Open Source Codes > com > sun > org > apache > bcel > internal > generic > InvokeInstruction


1 package com.sun.org.apache.bcel.internal.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 com.sun.org.apache.bcel.internal.Constants;
57 import com.sun.org.apache.bcel.internal.classfile.*;
58 import java.util.StringTokenizer JavaDoc;
59
60 /**
61  * Super class for the INVOKExxx family of instructions.
62  *
63  * @version $Id: InvokeInstruction.java,v 1.1.1.1 2001/10/29 20:00:20 jvanzyl Exp $
64  * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
65  */
66 public abstract class InvokeInstruction extends FieldOrMethod
67   implements ExceptionThrower, TypedInstruction, StackConsumer, StackProducer {
68   /**
69    * Empty constructor needed for the Class.newInstance() statement in
70    * Instruction.readInstruction(). Not to be used otherwise.
71    */
72   InvokeInstruction() {}
73
74   /**
75    * @param index to constant pool
76    */
77   protected InvokeInstruction(short opcode, int index) {
78     super(opcode, index);
79   }
80
81   /**
82    * @return mnemonic for instruction with symbolic references resolved
83    */
84   public String JavaDoc toString(ConstantPool cp) {
85     Constant c = cp.getConstant(index);
86     StringTokenizer JavaDoc tok = new StringTokenizer JavaDoc(cp.constantToString(c));
87
88     return Constants.OPCODE_NAMES[opcode] + " " +
89       tok.nextToken().replace('.', '/') + tok.nextToken();
90   }
91
92   /**
93    * Also works for instructions whose stack effect depends on the
94    * constant pool entry they reference.
95    * @return Number of words consumed from stack by this instruction
96    */
97   public int consumeStack(ConstantPoolGen cpg) {
98       String JavaDoc signature = getSignature(cpg);
99       Type[] args = Type.getArgumentTypes(signature);
100       int sum;
101
102       if(opcode == Constants.INVOKESTATIC)
103     sum = 0;
104       else
105     sum = 1; // this reference
106
107       int n = args.length;
108       for (int i = 0; i < n; i++)
109     sum += args[i].getSize();
110
111       return sum;
112    }
113
114   /**
115    * Also works for instructions whose stack effect depends on the
116    * constant pool entry they reference.
117    * @return Number of words produced onto stack by this instruction
118    */
119   public int produceStack(ConstantPoolGen cpg) {
120     return getReturnType(cpg).getSize();
121   }
122
123   /** @return return type of referenced method.
124    */
125   public Type getType(ConstantPoolGen cpg) {
126     return getReturnType(cpg);
127   }
128
129   /** @return name of referenced method.
130    */
131   public String JavaDoc getMethodName(ConstantPoolGen cpg) {
132     return getName(cpg);
133   }
134
135   /** @return return type of referenced method.
136    */
137   public Type getReturnType(ConstantPoolGen cpg) {
138     return Type.getReturnType(getSignature(cpg));
139   }
140
141   /** @return argument types of referenced method.
142    */
143   public Type[] getArgumentTypes(ConstantPoolGen cpg) {
144     return Type.getArgumentTypes(getSignature(cpg));
145   }
146 }
147
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