1 cananian 1.1.2.1 // OffsetMap.java, created Thu Jan 14 22:17:20 1999 by duncan
2 cananian 1.1.2.2 // Copyright (C) 1998 Duncan Bryce <duncan@lcs.mit.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.Interpret.Tree;
5 cananian 1.1.2.1
6 cananian 1.1.2.1 import harpoon.ClassFile.HMethod;
7 cananian 1.1.2.1 import harpoon.ClassFile.HField;
8 cananian 1.1.2.1 import harpoon.ClassFile.HClass;
9 cananian 1.1.2.1 import harpoon.Temp.Label;
10 cananian 1.1.2.1
11 cananian 1.1.2.1 import java.util.Set;
12 cananian 1.1.2.1
13 cananian 1.1.2.1 /**
14 cananian 1.1.2.1 * An <code>OffsetMap</code> maps an <code>HField</code> or an
15 cananian 1.1.2.1 * <code>HMethod</code> to an offset in bytes. It also reports the
16 cananian 1.1.2.1 * total size of an <code>HClass</code> object.
17 cananian 1.1.2.1 *
18 cananian 1.1.2.2 * @author Duncan Bryce <duncan@lcs.mit.edu>
19 cananian 1.2 * @version $Id: OffsetMap.java,v 1.2 2002/02/25 21:06:01 cananian Exp $
20 cananian 1.1.2.1 */
21 cananian 1.1.2.1 abstract class OffsetMap { // use an abstract class, if we can.
22 cananian 1.1.2.1
23 cananian 1.1.2.1 /** Maps an <code>HClass</code> to an offset (in bytes).
24 cananian 1.1.2.1 * Returns the offset from an object reference of the class pointer */
25 cananian 1.1.2.1 public abstract int clazzPtrOffset(HClass hc);
26 cananian 1.1.2.1
27 cananian 1.1.2.1 /** If returns the offset from the clazz pointer of the component type
28 cananian 1.1.2.1 * of <code>hc</code>. This location in memory will contain
29 cananian 1.1.2.1 * <code>null</code> if <code>hc</code> is not an array. If
30 cananian 1.1.2.1 * <code>hc</code> is an array, contains a pointer to the
31 cananian 1.1.2.1 * component type of the array. */
32 cananian 1.1.2.1 public abstract int componentTypeOffset(HClass hc);
33 cananian 1.1.2.1
34 cananian 1.1.2.1 /** Returns the size (in bytes) of the display information.
35 cananian 1.1.2.1 */
36 cananian 1.1.2.1 public abstract int displaySize();
37 cananian 1.1.2.1
38 cananian 1.1.2.1 /** Maps an <code>HClass</code> to an offset (in bytes).
39 cananian 1.1.2.1 * If hc is an array type, returns the offset of the
40 cananian 1.1.2.1 * array's 0th element. */
41 cananian 1.1.2.1 public abstract int elementsOffset(HClass hc);
42 cananian 1.1.2.1
43 cananian 1.1.2.1 /** Maps an <code>HClass</code> to an offset (in bytes).
44 cananian 1.1.2.1 * Returns the offset of the object's first field. */
45 cananian 1.1.2.1 public abstract int fieldsOffset(HClass hc);
46 cananian 1.1.2.1
47 cananian 1.1.2.1 /** Maps an <code>HClass</code> to an offset (in bytes).
48 cananian 1.1.2.1 * Returns the offset from an object reference at which the hashcode
49 cananian 1.1.2.1 * is stored. */
50 cananian 1.1.2.1 public abstract int hashCodeOffset(HClass hc);
51 cananian 1.1.2.1
52 cananian 1.1.2.1 /** Returns the offset from the class pointer of the list of interfaces
53 cananian 1.1.2.1 * implemented by the specified class
54 cananian 1.1.2.1 */
55 cananian 1.1.2.1 public abstract int interfaceListOffset(HClass hc);
56 cananian 1.1.2.1
57 cananian 1.1.2.1 /** Maps an <code>HClass</code> to an offset (in bytes).
58 cananian 1.1.2.1 * If <code>hc</code> is an array type, returns the offset from
59 cananian 1.1.2.1 * an object reference of the array's length field. */
60 cananian 1.1.2.1 public abstract int lengthOffset(HClass hc);
61 cananian 1.1.2.1
62 cananian 1.1.2.1 /** Maps an <code>HClass</code> to an offset (in bytes).
63 cananian 1.1.2.1 * Returns the offset from the class pointer of the specified
64 cananian 1.1.2.1 * class. This will be some function of the class's depth in
65 cananian 1.1.2.1 * the class hierarchy. */
66 cananian 1.1.2.1 public abstract int offset(HClass hc);
67 cananian 1.1.2.1
68 cananian 1.1.2.1 /** Maps a non-static <code>HField</code> to an offset (in bytes).
69 cananian 1.1.2.1 * If the field is inlined using type 1 inlining (which preserves
70 cananian 1.1.2.1 * the class pointer) then the specified offset points just after the
71 cananian 1.1.2.1 * class descriptor, in the same place a normal object pointer points.
72 cananian 1.1.2.1 * If the field in inlined using type 2 inlining (which omits the
73 cananian 1.1.2.1 * class pointer) then the specified offset points to the first field
74 cananian 1.1.2.1 * of the object. */
75 cananian 1.1.2.1 public abstract int offset(HField hf);
76 cananian 1.1.2.1
77 cananian 1.1.2.1 /** Maps a non-static <code>HMethod</code> to an offset (in bytes).
78 cananian 1.1.2.1 * This method must work for interface methods as well as class methods.*/
79 cananian 1.1.2.1 public abstract int offset(HMethod hm);
80 cananian 1.1.2.1
81 cananian 1.1.2.1 /** Maps an <code>HClass</code> to a size (in bytes). */
82 cananian 1.1.2.1 public abstract int size(HClass hc);
83 cananian 1.1.2.1
84 cananian 1.1.2.1 /** Returns the size (in bytes) of a word in the architecture represented
85 cananian 1.1.2.1 * by this <code>OffsetMap</code>. */
86 cananian 1.1.2.1 public abstract int wordsize();
87 cananian 1.1.2.1 }
88 cananian 1.1.2.1
89 cananian 1.1.2.1
90 cananian 1.2