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Java > Open Source Codes > soot > toolkits > graph > CompleteUnitGraph


1 /* Soot - a J*va Optimization Framework
2  * Copyright (C) 1999 Patrice Pominville, Raja Vallee-Rai
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with this library; if not, write to the
16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17  * Boston, MA 02111-1307, USA.
18  */
19
20 /*
21  * Modified by the Sable Research Group and others 1997-2004.
22  * See the 'credits' file distributed with Soot for the complete list of
23  * contributors. (Soot is distributed at http://www.sable.mcgill.ca/soot)
24  */
25
26 package soot.toolkits.graph;
27
28 import soot.Body;
29 import soot.toolkits.graph.ExceptionalUnitGraph;
30 import soot.toolkits.exceptions.PedanticThrowAnalysis;
31
32 /**
33  * <p>Represents a CFG for a {@link Body} instance where the nodes
34  * are {@link soot.Unit} instances, and where control flow
35  * associated with exceptions is taken into account. In a
36  * <code>CompleteUnitGraph</code>, every <code>Unit</code> covered by
37  * a {@link soot.Trap} is considered to have the potential to
38  * throw an exception caught by the <code>Trap</code>, so there are
39  * edges to the <code>Trap</code>'s handler from every trapped
40  * <code>Unit</code> , as well as from all the predecessors of the
41  * trapped <code>Unit</code>s.
42  *
43  * <p>This implementation of <code>CompleteUnitGraph</code> is
44  * included for backwards compatibility (new code should use {@link
45  * ExceptionalUnitGraph}), but the graphs it produces are not
46  * necessarily identical to the graphs produced by the implementation
47  * of <code>CompleteUnitGraph</code> provided by versions of Soot up
48  * to and including release 2.1.0. The known differences include:
49  *
50  * <ul>
51  *
52  * <li>If a <code>Body</code> includes <code>Unit</code>s which
53  * branch into the middle of the region protected by a
54  * <code>Trap</code> this implementation of
55  * <code>CompleteUnitGraph</code> will include edges from those
56  * branching <code>Unit</code>s to the <code>Trap</code>'s handler
57  * (since the branches are predecessors of an instruction which may
58  * throw an exception caught by the <code>Trap</code>). The 2.1.0
59  * implementation of <code>CompleteUnitGraph</code> mistakenly
60  * omitted these edges.</li>
61  *
62  * <li>If the initial <code>Unit</code> in the <code>Body</code>
63  * might throw an exception caught by a <code>Trap</code> within the
64  * body, this implementation will include the initial handler
65  * <code>Unit</code> in the list returned by
66  * <code>getHeads()</code> (since the handler unit might be the first
67  * Unit in the method to execute to completion). The 2.1.0
68  * implementation of <code>CompleteUnitGraph</code> mistakenly
69  * omitted the handler from the set of heads.</li>
70  *
71  * </ul></p>
72  */
73 public class CompleteUnitGraph extends ExceptionalUnitGraph
74 {
75     public CompleteUnitGraph(Body b) {
76     super(b, PedanticThrowAnalysis.v(), false);
77     }
78 }
79
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