01: /*
02: * Bytecode Analysis Framework
03: * Copyright (C) 2003,2004 University of Maryland
04: *
05: * This library is free software; you can redistribute it and/or
06: * modify it under the terms of the GNU Lesser General Public
07: * License as published by the Free Software Foundation; either
08: * version 2.1 of the License, or (at your option) any later version.
09: *
10: * This library is distributed in the hope that it will be useful,
11: * but WITHOUT ANY WARRANTY; without even the implied warranty of
12: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13: * Lesser General Public License for more details.
14: *
15: * You should have received a copy of the GNU Lesser General Public
16: * License along with this library; if not, write to the Free Software
17: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18: */
19:
20: package edu.umd.cs.findbugs.ba;
21:
22: import java.util.Comparator;
23:
24: /**
25: * A BlockOrder for visiting the blocks of a CFG in
26: * the reverse of the order in which they are finished in
27: * a depth first search. This is the most efficient visitation
28: * order for forward dataflow analyses.
29: *
30: * @see BlockOrder
31: * @see DepthFirstSearch
32: * @see CFG
33: * @see BasicBlock
34: */
35: public class ReversePostOrder extends AbstractBlockOrder {
36: /**
37: * A Comparator to order the blocks in the reverse of the
38: * order in which they would be finished by a depth first search.
39: */
40: private static class ReversePostfixComparator implements
41: Comparator<BasicBlock> {
42: private DepthFirstSearch dfs;
43:
44: public ReversePostfixComparator(DepthFirstSearch dfs) {
45: this .dfs = dfs;
46: }
47:
48: public int compare(BasicBlock aa, BasicBlock bb) {
49: return dfs.getFinishTime(bb) - dfs.getFinishTime(aa);
50: }
51: }
52:
53: /**
54: * Constructor.
55: *
56: * @param cfg the CFG for the method
57: * @param dfs the DepthFirstSearch on the method
58: */
59: public ReversePostOrder(CFG cfg, DepthFirstSearch dfs) {
60: super (cfg, new ReversePostfixComparator(dfs));
61: }
62: }
63:
64: // vim:ts=4
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