KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > com > sun > org > apache > bcel > internal > verifier > structurals > InstructionContext


1 package com.sun.org.apache.bcel.internal.verifier.structurals;
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
57 import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
58 import java.util.ArrayList JavaDoc;
59 import java.util.Iterator JavaDoc;
60
61 /**
62  * An InstructionContext offers convenient access
63  * to information like control flow successors and
64  * such.
65  *
66  * @version $Id: InstructionContext.java,v 1.1.1.1 2001/10/29 20:00:41 jvanzyl Exp $
67  * @author <A HREF="http://www.inf.fu-berlin.de/~ehaase"/>Enver Haase</A>
68  */
69 public interface InstructionContext{
70
71     /**
72      * The getTag and setTag methods may be used for
73      * temporary flagging, such as graph colouring.
74      * Nothing in the InstructionContext object depends
75      * on the value of the tag. JustIce does not use it.
76      *
77      * @see #setTag(int tag)
78      */
79     public int getTag();
80
81     /**
82      * The getTag and setTag methods may be used for
83      * temporary flagging, such as graph colouring.
84      * Nothing in the InstructionContext object depends
85      * on the value of the tag. JustIce does not use it.
86      *
87      * @see #getTag()
88      */
89     public void setTag(int tag);
90
91     /**
92      * This method symbolically executes the Instruction
93      * held in the InstructionContext.
94      * It "merges in" the incoming execution frame situation
95      * (see The Java Virtual Machine Specification, 2nd
96      * edition, page 146).
97      * By so doing, the outgoing execution frame situation
98      * is calculated.
99      *
100      * This method is JustIce-specific and is usually of
101      * no sense for users of the ControlFlowGraph class.
102      * They should use getInstruction().accept(Visitor),
103      * possibly in conjunction with the ExecutionVisitor.
104      *
105      *
106      * @see ControlFlowGraph
107      * @see ExecutionVisitor
108      * @see #getOutFrame(ArrayList)
109      * @return true - if and only if the "outgoing" frame situation
110      * changed from the one before execute()ing.
111      */
112     boolean execute(Frame inFrame, ArrayList JavaDoc executionPredecessors, InstConstraintVisitor icv, ExecutionVisitor ev);
113
114     /**
115      * This method returns the outgoing execution frame situation;
116      * therefore <B>it has to be calculated by execute(Frame, ArrayList)
117      * first.</B>
118      *
119      * @see #execute(Frame, ArrayList, InstConstraintVisitor, ExecutionVisitor)
120      */
121     Frame getOutFrame(ArrayList JavaDoc executionPredecessors);
122     
123     /**
124      * Returns the InstructionHandle this InstructionContext is wrapped around.
125      *
126      * @return The InstructionHandle this InstructionContext is wrapped around.
127      */
128     InstructionHandle getInstruction();
129
130     /**
131      * Returns the usual control flow successors.
132      * @see #getExceptionHandlers()
133      */
134     InstructionContext[] getSuccessors();
135
136     /**
137      * Returns the exception handlers that protect this instruction.
138      * They are special control flow successors.
139      */
140     ExceptionHandler[] getExceptionHandlers();
141 }
142
Popular Tags