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Java > Open Source Codes > com > tc > asm > tree > analysis > BasicValue


1 /***
2  * ASM: a very small and fast Java bytecode manipulation framework
3  * Copyright (c) 2000-2005 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 package com.tc.asm.tree.analysis;
31
32 import com.tc.asm.Type;
33
34 /**
35  * A {@link Value} that is represented by its type in a seven types type sytem.
36  * This type system distinguishes the UNINITIALZED, INT, FLOAT, LONG, DOUBLE,
37  * REFERENCE and RETURNADDRESS types.
38  *
39  * @author Eric Bruneton
40  */
41 public class BasicValue implements Value {
42
43     public final static Value UNINITIALIZED_VALUE = new BasicValue(null);
44
45     public final static Value INT_VALUE = new BasicValue(Type.INT_TYPE);
46
47     public final static Value FLOAT_VALUE = new BasicValue(Type.FLOAT_TYPE);
48
49     public final static Value LONG_VALUE = new BasicValue(Type.LONG_TYPE);
50
51     public final static Value DOUBLE_VALUE = new BasicValue(Type.DOUBLE_TYPE);
52
53     public final static Value REFERENCE_VALUE = new BasicValue(Type.getType("Ljava/lang/Object;"));
54
55     public final static Value RETURNADDRESS_VALUE = new BasicValue(null);
56
57     private Type type;
58
59     public BasicValue(final Type type) {
60         this.type = type;
61     }
62
63     public Type getType() {
64         return type;
65     }
66
67     public int getSize() {
68         return type == Type.LONG_TYPE || type == Type.DOUBLE_TYPE ? 2 : 1;
69     }
70
71     public boolean isReference() {
72         return type != null
73                 && (type.getSort() == Type.OBJECT || type.getSort() == Type.ARRAY);
74     }
75
76     public boolean equals(final Object JavaDoc value) {
77         if (value == this) {
78             return true;
79         } else if (value instanceof BasicValue) {
80             if (type == null) {
81                 return ((BasicValue) value).type == null;
82             } else {
83                 return type.equals(((BasicValue) value).type);
84             }
85         } else {
86             return false;
87         }
88     }
89
90     public int hashCode() {
91         return type == null ? 0 : type.hashCode();
92     }
93
94     public String JavaDoc toString() {
95         if (this == UNINITIALIZED_VALUE) {
96             return ".";
97         } else if (this == RETURNADDRESS_VALUE) {
98             return "A";
99         } else if (this == REFERENCE_VALUE) {
100             return "R";
101         } else {
102             return type.getDescriptor();
103         }
104     }
105 }
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