1 cananian 1.1.2.1 // FOOTER.java, created Mon Sep 7 10:36:08 1998 by cananian
2 cananian 1.1.2.1 // Copyright (C) 1998 C. Scott Ananian <cananian@alumni.princeton.edu>
3 cananian 1.1.2.1 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 cananian 1.1.2.1 package harpoon.IR.Quads;
5 cananian 1.1.2.1
6 cananian 1.1.2.9 import harpoon.ClassFile.HCodeElement;
7 cananian 1.1.2.1 import harpoon.Temp.TempMap;
8 cananian 1.1.2.1 import harpoon.Util.Util;
9 cananian 1.1.2.1 /**
10 cananian 1.1.2.1 * <code>FOOTER</code> nodes are used to anchor the bottom end of the quad
11 cananian 1.1.2.1 * graph. They do not represent bytecode and are not executable. <p>
12 cananian 1.1.2.1 * <code>RETURN</code> and <code>THROW</code> nodes should have a
13 cananian 1.1.2.1 * <code>FOOTER</code> node as their only successor.
14 cananian 1.1.2.1 *
15 cananian 1.1.2.1 * @author C. Scott Ananian <cananian@alumni.princeton.edu>
16 cananian 1.3 * @version $Id: FOOTER.java,v 1.3 2002/04/11 04:00:34 cananian Exp $
17 cananian 1.1.2.1 * @see HEADER
18 cananian 1.1.2.1 * @see RETURN
19 cananian 1.1.2.1 * @see THROW
20 cananian 1.1.2.1 */
21 cananian 1.1.2.1
22 cananian 1.1.2.1 public class FOOTER extends Quad {
23 cananian 1.1.2.1
24 cananian 1.1.2.1 /** Creates a <code>FOOTER</code>. */
25 cananian 1.1.2.4 public FOOTER(QuadFactory qf, HCodeElement source, int arity) {
26 cananian 1.1.2.4 super(qf, source, arity/*num predecessors*/, 0/*no successors ever*/);
27 cananian 1.1.2.1 }
28 cananian 1.1.2.4 /** Returns the number of predecessors of this <Code>FOOTER</code>. */
29 cananian 1.1.2.4 public int arity() { return prev.length; }
30 cananian 1.1.2.1
31 cananian 1.1.2.8 /** Attach a new Quad to this <code>FOOTER</code> by replacing it.
32 cananian 1.1.2.12 * @param q the new <code>Quad</code> to attach.
33 cananian 1.1.2.12 * @param which_succ the edge leaving q to attach to the
34 cananian 1.1.2.12 * <code>FOOTER</code>.
35 cananian 1.1.2.8 * @return the new <code>FOOTER</code>. */
36 cananian 1.1.2.8 public FOOTER attach(Quad q, int which_succ) {
37 cananian 1.1.2.10 FOOTER f = resize(arity()+1);
38 cananian 1.1.2.4 addEdge(q, which_succ, f, arity());
39 cananian 1.1.2.8 return f;
40 cananian 1.1.2.1 }
41 cananian 1.1.2.10 /** Change the arity of this <code>FOOTER</code> by replacing it.
42 cananian 1.1.2.12 * The new edges if any are the highest numbered incoming
43 cananian 1.1.2.12 * edges and are left null. */
44 cananian 1.1.2.10 public FOOTER resize(int new_arity) {
45 cananian 1.1.2.10 FOOTER f = new FOOTER(qf, this, new_arity);
46 cananian 1.1.2.10 for (int i=0; i<arity() && i<new_arity; i++)
47 cananian 1.1.2.10 Quad.addEdge(this.prev(i), this.prevEdge(i).which_succ(), f, i);
48 cananian 1.1.2.10 return f;
49 cananian 1.1.2.10 }
50 cananian 1.1.2.10
51 cananian 1.1.2.5 /** Remove an attachment from this <code>FOOTER</code> by replacing
52 cananian 1.1.2.8 * the footer.
53 cananian 1.1.2.12 * @param which_pred which incoming edge to remove.
54 cananian 1.1.2.8 * @return the new <code>FOOTER</code>. */
55 cananian 1.1.2.8 public FOOTER remove(int which_pred) {
56 cananian 1.1.2.4 FOOTER f = new FOOTER(qf, this, arity()-1);
57 cananian 1.1.2.4 for (int i=0, j=0; i<prev.length; i++)
58 cananian 1.1.2.4 if (i!=which_pred) {
59 cananian 1.1.2.4 Edge e = prevEdge(i);
60 cananian 1.1.2.4 Quad.addEdge((Quad)e.from(), e.which_succ(), f, j++);
61 cananian 1.1.2.4 }
62 cananian 1.1.2.8 return f;
63 cananian 1.1.2.1 }
64 cananian 1.1.2.1
65 cananian 1.1.2.2 public int kind() { return QuadKind.FOOTER; }
66 cananian 1.1.2.2
67 cananian 1.1.2.7 public Quad rename(QuadFactory qqf, TempMap defMap, TempMap useMap) {
68 cananian 1.1.2.4 return new FOOTER(qqf, this, prev.length);
69 cananian 1.1.2.2 }
70 cananian 1.1.2.1
71 cananian 1.1.2.11 public void accept(QuadVisitor v) { v.visit(this); }
72 cananian 1.3 public <T> T accept(QuadValueVisitor<T> v) { return v.visit(this); }
73 cananian 1.1.2.1
74 cananian 1.1.2.5 /** Returns human-readable representation of this <code>Quad</code>. */
75 cananian 1.1.2.4 public String toString() { return "FOOTER("+arity()+")"; }
76 cananian 1.2 }