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Java > Open Source Codes > com > sun > org > apache > bcel > internal > verifier > statics > LocalVariablesInfo


1 package com.sun.org.apache.bcel.internal.verifier.statics;
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.Constants;
58 import com.sun.org.apache.bcel.internal.generic.Type;
59 import com.sun.org.apache.bcel.internal.verifier.exc.*;
60
61 /**
62  * A utility class holding the information about
63  * the names and the types of the local variables in
64  * a given method.
65  *
66  * @version $Id: LocalVariablesInfo.java,v 1.1.1.1 2001/10/29 20:00:34 jvanzyl Exp $
67  * @author <A HREF="http://www.inf.fu-berlin.de/~ehaase"/>Enver Haase</A>
68  */

69 public class LocalVariablesInfo{
70     
71     /** The information about the local variables is stored here. */
72     private LocalVariableInfo[] localVariableInfos;
73
74     /**
75      * The ints in the list represent code offsets where either instructions must start
76      * or the offset is the length of the code array. This will be verified in Pass 3a.
77      */

78     private IntList instruction_offsets = new IntList();
79     
80     /** The constructor. */
81     LocalVariablesInfo(int max_locals){
82         localVariableInfos = new LocalVariableInfo[max_locals];
83         for (int i=0; i<max_locals; i++){
84             localVariableInfos[i] = new LocalVariableInfo();
85         }
86     }
87
88     /** Returns the LocalVariableInfo for the given slot. */
89     public LocalVariableInfo getLocalVariableInfo(int slot){
90         if (slot < 0 || slot >= localVariableInfos.length){
91             throw new AssertionViolatedException("Slot number for local variable information out of range.");
92         }
93         return localVariableInfos[slot];
94     }
95
96     /**
97      * Adds information about the local variable in slot 'slot'. Automatically
98      * adds information for slot+1 if 't' is Type.LONG or Type.DOUBLE.
99      * @throws LocalVariableInfoInconsistentException if the new information conflicts
100      * with already gathered information.
101      */

102     public void add(int slot, String JavaDoc name, int startpc, int length, Type t) throws LocalVariableInfoInconsistentException{
103         // The add operation on LocalVariableInfo may throw the '...Inconsistent...' exception, we don't throw it explicitely here.
104

105         if (slot < 0 || slot >= localVariableInfos.length){
106             throw new AssertionViolatedException("Slot number for local variable information out of range.");
107         }
108
109         localVariableInfos[slot].add(name, startpc, length, t);
110         if (t == Type.LONG) localVariableInfos[slot+1].add(name, startpc, length, LONG_Upper.theInstance());
111         if (t == Type.DOUBLE) localVariableInfos[slot+1].add(name, startpc, length, DOUBLE_Upper.theInstance());
112     }
113 }
114
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