/*
* Bytecode Analysis Framework
* Copyright (C) 2003,2004 University of Maryland
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package edu.umd.cs.findbugs.ba;
import java.util.Comparator;
/**
* A BlockOrder for visiting the blocks of a CFG in
* the order they would be visited in a depth first search
* of the reversed CFG. This is the most efficient visitation
* order for backwards dataflow analyses.
*
* @see BlockOrder
* @see ReverseDepthFirstSearch
* @see CFG
* @see BasicBlock
*/
public class ReverseDFSOrder extends AbstractBlockOrder {
public ReverseDepthFirstSearch rdfs;
public DepthFirstSearch dfs;
private static class ReverseDFSComparator implements Comparator<BasicBlock> {
public ReverseDepthFirstSearch rdfs;
public DepthFirstSearch dfs;
public ReverseDFSComparator(ReverseDepthFirstSearch rdfs, DepthFirstSearch dfs) {
if (rdfs == null) throw new IllegalArgumentException();
this.rdfs = rdfs;
if (dfs == null) throw new IllegalArgumentException();
this.dfs = dfs;
}
public int compare(BasicBlock a, BasicBlock b) {
return dfs.getFinishTime(a) - dfs.getFinishTime(b);
}
}
/**
* Constructor.
*
* @param cfg the CFG
* @param rdfs the ReverseDepthFirstSearch of the CFG
* @param dfs TODO
*/
public ReverseDFSOrder(CFG cfg, ReverseDepthFirstSearch rdfs, DepthFirstSearch dfs) {
super(cfg, new ReverseDFSComparator(rdfs, dfs));
this.rdfs = rdfs;
this.dfs = dfs;
}
}
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