01: /* Soot - a J*va Optimization Framework
02: * Copyright (C) 1999 Patrice Pominville, Raja Vallee-Rai
03: *
04: * This library is free software; you can redistribute it and/or
05: * modify it under the terms of the GNU Lesser General Public
06: * License as published by the Free Software Foundation; either
07: * version 2.1 of the License, or (at your option) any later version.
08: *
09: * 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: public CompleteUnitGraph(Body b) {
75: super (b, PedanticThrowAnalysis.v(), false);
76: }
77: }
|