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


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 java.util.Set JavaDoc;
33
34 import com.tc.asm.tree.AbstractInsnNode;
35
36 /**
37  * A {@link Value} that is represented by its type in a two types type system.
38  * This type system distinguishes the ONEWORD and TWOWORDS types.
39  *
40  * @author Eric Bruneton
41  */
42 public class DataflowValue implements Value {
43
44     /**
45      * The size of this value.
46      */
47     public final int size;
48
49     /**
50      * The instructions that can produce this value. For example, for the Java
51      * code below, the instructions that can produce the value of <tt>i</tt>
52      * at line 5 are the txo ISTORE instructions at line 1 and 3:
53      *
54      * <pre>
55      * 1: i = 0;
56      * 2: if (...) {
57      * 3: i = 1;
58      * 4: }
59      * 5: return i;
60      * </pre>
61      *
62      * This field is a set of {@link AbstractInsnNode} objects.
63      */
64     public final Set JavaDoc insns;
65
66     public DataflowValue(final int size) {
67         this(size, SmallSet.EMPTY_SET);
68     }
69
70     public DataflowValue(final int size, final AbstractInsnNode insn) {
71         this.size = size;
72         this.insns = new SmallSet(insn, null);
73     }
74
75     public DataflowValue(final int size, final Set JavaDoc insns) {
76         this.size = size;
77         this.insns = insns;
78     }
79
80     public int getSize() {
81         return size;
82     }
83
84     public boolean equals(final Object JavaDoc value) {
85         DataflowValue v = (DataflowValue) value;
86         return size == v.size && insns.equals(v.insns);
87     }
88
89     public int hashCode() {
90         return insns.hashCode();
91     }
92 }
93
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