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Java > Open Source Codes > oracle > toplink > libraries > asm > tree > analysis > BasicValue


1 /***
2  * ASM: a very small and fast Java bytecode manipulation framework
3  * Copyright (c) 2000,2002,2003 INRIA, France Telecom
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  * notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  * notice, this list of conditions and the following disclaimer in the
13  * documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the copyright holders nor the names of its
15  * contributors may be used to endorse or promote products derived from
16  * this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
28  * THE POSSIBILITY OF SUCH DAMAGE.
29  */
30
31 package oracle.toplink.libraries.asm.tree.analysis;
32
33 import oracle.toplink.libraries.asm.Type;
34
35 /**
36  * A {@link Value} that is represented by its type in a seven types type sytem.
37  * This type system distinguishes the UNINITIALZED, INT, FLOAT, LONG, DOUBLE,
38  * REFERENCE and RETURNADDRESS types.
39  *
40  * @author Eric Bruneton
41  */
42
43 public class BasicValue implements Value {
44
45   public final static Value UNINITIALIZED_VALUE = new BasicValue(null);
46   
47   public final static Value INT_VALUE = new BasicValue(Type.INT_TYPE);
48   
49   public final static Value FLOAT_VALUE = new BasicValue(Type.FLOAT_TYPE);
50   
51   public final static Value LONG_VALUE = new BasicValue(Type.LONG_TYPE);
52   
53   public final static Value DOUBLE_VALUE = new BasicValue(Type.DOUBLE_TYPE);
54   
55   public final static Value REFERENCE_VALUE = new BasicValue(Type.getType("Ljava/lang/Object;"));
56   
57   public final static Value RETURNADDRESS_VALUE = new BasicValue(null);
58   
59   private Type type;
60   
61   public BasicValue (final Type type) {
62     this.type = type;
63   }
64   
65   public Type getType () {
66     return type;
67   }
68   
69   public int getSize () {
70     return type == Type.LONG_TYPE || type == Type.DOUBLE_TYPE ? 2 : 1;
71   }
72   
73   public boolean isReference () {
74     return type != null && (type.getSort() == Type.OBJECT || type.getSort() == Type.ARRAY);
75   }
76   
77   public boolean equals (final Value value) {
78     if (value == this) {
79       return true;
80     } else if (value instanceof BasicValue) {
81       if (type == null) {
82         return ((BasicValue)value).type == null;
83       } else {
84         return type.equals(((BasicValue)value).type);
85       }
86     } else {
87       return false;
88     }
89   }
90   
91   public String JavaDoc toString () {
92     if (this == UNINITIALIZED_VALUE) {
93       return ".";
94     } else if (this == RETURNADDRESS_VALUE) {
95       return "A";
96     } else if (this == REFERENCE_VALUE) {
97       return "R";
98     } else {
99       return type.getDescriptor();
100     }
101   }
102 }
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