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


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.classfile.ConstantPool;
57 import com.sun.org.apache.bcel.internal.Constants;
58 import com.sun.org.apache.bcel.internal.ExceptionConstants;
59
60 import java.io.*;
61 import com.sun.org.apache.bcel.internal.util.ByteSequence;
62
63 /**
64  * INVOKEINTERFACE - Invoke interface method
65  * <PRE>Stack: ..., objectref, [arg1, [arg2 ...]] -&gt; ...</PRE>
66  *
67  * @version $Id: INVOKEINTERFACE.java,v 1.1.1.1 2001/10/29 20:00:16 jvanzyl Exp $
68  * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
69  */
70 public final class INVOKEINTERFACE extends InvokeInstruction {
71   private int nargs; // Number of arguments on stack (number of stack slots), called "count" in vmspec2
72
73   /**
74    * Empty constructor needed for the Class.newInstance() statement in
75    * Instruction.readInstruction(). Not to be used otherwise.
76    */
77   INVOKEINTERFACE() {}
78
79   public INVOKEINTERFACE(int index, int nargs) {
80     super(Constants.INVOKEINTERFACE, index);
81     length = 5;
82
83     if(nargs < 1)
84       throw new ClassGenException("Number of arguments must be > 0 " + nargs);
85
86     this.nargs = nargs;
87   }
88
89   /**
90    * Dump instruction as byte code to stream out.
91    * @param out Output stream
92    */
93   public void dump(DataOutputStream out) throws IOException {
94     out.writeByte(opcode);
95     out.writeShort(index);
96     out.writeByte(nargs);
97     out.writeByte(0);
98   }
99
100   /**
101    * The <B>count</B> argument according to the Java Language Specification,
102    * Second Edition.
103    */
104   public int getCount() { return nargs; }
105
106   /**
107    * Read needed data (i.e., index) from file.
108    */
109   protected void initFromFile(ByteSequence bytes, boolean wide)
110        throws IOException
111   {
112     super.initFromFile(bytes, wide);
113
114     length = 5;
115     nargs = bytes.readUnsignedByte();
116     bytes.readByte(); // Skip 0 byte
117 }
118
119   /**
120    * @return mnemonic for instruction with symbolic references resolved
121    */
122   public String JavaDoc toString(ConstantPool cp) {
123     return super.toString(cp) + " " + nargs;
124   }
125
126   public int consumeStack(ConstantPoolGen cpg) { // nargs is given in byte-code
127 return nargs; // nargs includes this reference
128 }
129
130   public Class JavaDoc[] getExceptions() {
131     Class JavaDoc[] cs = new Class JavaDoc[4 + ExceptionConstants.EXCS_INTERFACE_METHOD_RESOLUTION.length];
132
133     System.arraycopy(ExceptionConstants.EXCS_INTERFACE_METHOD_RESOLUTION, 0,
134              cs, 0, ExceptionConstants.EXCS_INTERFACE_METHOD_RESOLUTION.length);
135
136     cs[ExceptionConstants.EXCS_INTERFACE_METHOD_RESOLUTION.length+3] = ExceptionConstants.INCOMPATIBLE_CLASS_CHANGE_ERROR;
137     cs[ExceptionConstants.EXCS_INTERFACE_METHOD_RESOLUTION.length+2] = ExceptionConstants.ILLEGAL_ACCESS_ERROR;
138     cs[ExceptionConstants.EXCS_INTERFACE_METHOD_RESOLUTION.length+1] = ExceptionConstants.ABSTRACT_METHOD_ERROR;
139     cs[ExceptionConstants.EXCS_INTERFACE_METHOD_RESOLUTION.length] = ExceptionConstants.UNSATISFIED_LINK_ERROR;
140
141     return cs;
142   }
143
144   /**
145    * Call corresponding visitor method(s). The order is:
146    * Call visitor methods of implemented interfaces first, then
147    * call methods according to the class hierarchy in descending order,
148    * i.e., the most specific visitXXX() call comes last.
149    *
150    * @param v Visitor object
151    */
152   public void accept(Visitor v) {
153     v.visitExceptionThrower(this);
154     v.visitTypedInstruction(this);
155     v.visitStackConsumer(this);
156     v.visitStackProducer(this);
157     v.visitLoadClass(this);
158     v.visitCPInstruction(this);
159     v.visitFieldOrMethod(this);
160     v.visitInvokeInstruction(this);
161     v.visitINVOKEINTERFACE(this);
162   }
163 }
164
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