1 pnkfelix 1.1.2.1 // EdgesIterator.java, created Mon Apr 5 16:15:47 1999 by pnkfelix
2 cananian 1.1.2.6 // Copyright (C) 1999 Felix S. Klock II <pnkfelix@mit.edu>
3 pnkfelix 1.1.2.1 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 pnkfelix 1.1.2.1 package harpoon.Analysis;
5 pnkfelix 1.1.2.1
6 cananian 1.1.2.5 import harpoon.ClassFile.HCodeEdge;
7 cananian 1.1.2.5 import harpoon.ClassFile.HCodeElement;
8 cananian 1.1.2.4 import harpoon.IR.Properties.CFGraphable;
9 cananian 1.1.2.5 import harpoon.IR.Properties.CFGrapher;
10 cananian 1.5 import net.cscott.jutil.UnmodifiableIterator;
11 cananian 1.5 import net.cscott.jutil.WorkSet;
12 pnkfelix 1.1.2.1
13 pnkfelix 1.1.2.1 import java.util.Iterator;
14 pnkfelix 1.1.2.1 import java.util.Set;
15 pnkfelix 1.1.2.1 import java.util.HashSet;
16 pnkfelix 1.1.2.1
17 pnkfelix 1.1.2.1 /**
18 pnkfelix 1.1.2.1 * <code>EdgesIterator</code> is a generic iterator for a set of
19 cananian 1.1.2.4 * <code>CFGraphable</code> objects.
20 pnkfelix 1.1.2.1 *
21 cananian 1.1.2.6 * @author Felix S. Klock II <pnkfelix@mit.edu>
22 cananian 1.6 * @version $Id: EdgesIterator.java,v 1.6 2004/02/08 03:19:12 cananian Exp $
23 pnkfelix 1.1.2.1 */
24 cananian 1.1.2.3 public class EdgesIterator extends UnmodifiableIterator implements Iterator {
25 cananian 1.1.2.5 private CFGrapher grapher;
26 pnkfelix 1.1.2.1
27 cananian 1.1.2.5 private WorkSet worklist;
28 pnkfelix 1.1.2.1 private Set done;
29 pnkfelix 1.1.2.1
30 cananian 1.1.2.5 /** Convenience constructor. */
31 cananian 1.1.2.5 public EdgesIterator(CFGraphable e) {
32 cananian 1.1.2.5 this(e, CFGrapher.DEFAULT);
33 cananian 1.1.2.5 }
34 pnkfelix 1.1.2.1 /** Creates a <code>EdgesIterator</code> for all the edges
35 pnkfelix 1.1.2.1 reachable by recursively traversing the successors of
36 pnkfelix 1.1.2.1 <code>e</code>. Predecessors are not included in the set.
37 pnkfelix 1.1.2.1 */
38 cananian 1.1.2.5 public EdgesIterator(HCodeElement e, CFGrapher grapher) {
39 cananian 1.1.2.5 this.grapher = grapher;
40 cananian 1.1.2.5 worklist = new WorkSet();
41 pnkfelix 1.1.2.1 done = new HashSet();
42 pnkfelix 1.1.2.1 worklist.add(e);
43 pnkfelix 1.1.2.1 done.add(e);
44 pnkfelix 1.1.2.1 }
45 pnkfelix 1.1.2.1
46 pnkfelix 1.1.2.1 /** Checks if the set is empty.
47 cananian 1.1.2.4 <BR> <B>effects:</B> returns true if more <code>CFGraphable</code>
48 pnkfelix 1.1.2.1 remain in the set. Else returns false.
49 pnkfelix 1.1.2.1 */
50 pnkfelix 1.1.2.1 public boolean hasNext() { return worklist.size()!=0; }
51 pnkfelix 1.1.2.1
52 cananian 1.1.2.4 /** Returns an <code>CFGraphable</code> if one remains.
53 pnkfelix 1.1.2.1 <BR> <B>requires:</B> <code>this.hasNext()</code> == true.
54 cananian 1.1.2.4 <BR> <B>effects:</B> returns an <code>CFGraphable</code> from the
55 pnkfelix 1.1.2.1 set contained in <code>this</code> and removes it from the
56 pnkfelix 1.1.2.1 set.
57 pnkfelix 1.1.2.1 */
58 pnkfelix 1.1.2.1 public Object next() {
59 cananian 1.1.2.5 HCodeElement e = (HCodeElement) worklist.pop();
60 cananian 1.6 for (Object edgeO : grapher.succC(e)) {
61 cananian 1.6 HCodeEdge edge = (HCodeEdge) edgeO;
62 cananian 1.4 HCodeElement ne = edge.to();
63 pnkfelix 1.1.2.1 if (!done.contains(ne)) {
64 pnkfelix 1.1.2.1 done.add(ne);
65 pnkfelix 1.1.2.1 worklist.add(ne);
66 pnkfelix 1.1.2.1 }
67 pnkfelix 1.1.2.1 }
68 pnkfelix 1.1.2.1 return e;
69 pnkfelix 1.1.2.1 }
70 cananian 1.2 }