1 cananian 1.1 // TypeMap.java, created Wed Aug 19 01:02:27 1998 by cananian
2 cananian 1.3 // Copyright (C) 1998 C. Scott Ananian <cananian@alumni.princeton.edu>
3 cananian 1.3 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 cananian 1.1 package harpoon.Analysis.Maps;
5 cananian 1.1
6 cananian 1.1 import harpoon.Temp.Temp;
7 cananian 1.1 import harpoon.ClassFile.HClass;
8 duncan 1.3.2.2 import harpoon.ClassFile.HCodeElement;
9 cananian 1.1
10 cananian 1.1 /**
11 cananian 1.2 * A <code>TypeMap</code> is a mapping from temporaries to their types.
12 cananian 1.1 *
13 cananian 1.1 * @author C. Scott Ananian <cananian@alumni.princeton.edu>
14 cananian 1.5 * @version $Id: TypeMap.java,v 1.5 2002/09/02 19:23:26 cananian Exp $
15 cananian 1.1 */
16 cananian 1.5 public interface TypeMap<HCE extends HCodeElement> {
17 cananian 1.1 /**
18 cananian 1.3.2.3 * Return the type of a given temporary <code>t</code>, as defined
19 cananian 1.3.2.3 * at the definition point <code>hce</code>. Iff the type of the
20 cananian 1.3.2.3 * temporary is not known, or if <code>hce</code> does not define
21 cananian 1.3.2.3 * <code>t</code>, throws <code>TypeNotKnownException</code>. If
22 cananian 1.3.2.3 * the temporary represents a derived pointer, <code>null</code>
23 cananian 1.3.2.3 * should be returned; in which case the <code>Derivation</code>
24 cananian 1.3.2.3 * <b>must</b> return a non-<code>null</code> value. Obviously,
25 cananian 1.3.2.3 * <code>TypeMap</code>s for high-level representations without
26 cananian 1.3.2.3 * derived pointers should never return <code>null</code>. As a
27 cananian 1.3.2.3 * special case, <code>HClass.Void</code> may be returned in
28 cananian 1.3.2.3 * low-level IRs to indicate an opaque pointer value which does
29 cananian 1.3.2.3 * <b>not</b> correspond to a java object pointer or some
30 cananian 1.3.2.3 * derivation thereof --- for example, a pointer into a method
31 cananian 1.3.2.4 * dispatch table. The only other time <code>HClass.Void</code>
32 cananian 1.3.2.4 * should be returned is for known-<code>null</code> pointer values.
33 duncan 1.3.2.1 *
34 cananian 1.3.2.3 * @param hce The <code>HCodeElement</code> defining <code>t</code>.
35 cananian 1.1 * @param t The temporary to examine.
36 duncan 1.3.2.1 * @return the static type of <code>t</code>.
37 cananian 1.3.2.3 * @exception NullPointerException if <code>t</code> or <code>hc</code>
38 cananian 1.3.2.3 * is <code>null</code>.
39 cananian 1.3.2.3 * @exception TypeNotKnownException if the <code>TypeMap</code> does
40 cananian 1.3.2.3 * not have any information about <code>t</code> as defined
41 cananian 1.3.2.3 * at <code>hc</code>. */
42 cananian 1.5 public HClass typeMap(HCE hce, Temp t)
43 cananian 1.3.2.3 throws TypeNotKnownException;
44 cananian 1.3.2.3
45 cananian 1.3.2.3 /** <code>TypeNotKnownException</code> is thrown to indicate that
46 cananian 1.3.2.3 * the <code>TypeMap</code> does not have type information for the
47 cananian 1.3.2.3 * specified <code>Temp</code> in the given <code>HCodeElement</code>.
48 cananian 1.3.2.3 * This could be because the <code>HCodeElement</code> does not
49 cananian 1.3.2.3 * define the specified <code>Temp</code>, or because the type
50 cananian 1.3.2.3 * analysis was faulty. In either case, this exception should
51 cananian 1.3.2.3 * never be caught -- it indicates a flaw in either the type
52 cananian 1.3.2.3 * analysis or the querying method, which should be fixed. */
53 cananian 1.3.2.3 public static class TypeNotKnownException extends RuntimeException {
54 cananian 1.3.2.3 public TypeNotKnownException(HCodeElement hce, Temp t) {
55 cananian 1.3.2.3 super("Type not known for Temp "+t+" in "+hce);
56 cananian 1.3.2.3 }
57 cananian 1.3.2.3 }
58 cananian 1.1 }