1 cananian 1.1.4.1 // ClassFieldMap.java, created Sun Oct 10 19:30:33 1999 by cananian
2 cananian 1.1.4.1 // Copyright (C) 1999 C. Scott Ananian <cananian@alumni.princeton.edu>
3 cananian 1.1.4.1 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 cananian 1.1.4.1 package harpoon.Backend.Analysis;
5 cananian 1.1.4.1
6 cananian 1.1.4.1 import harpoon.ClassFile.HClass;
7 cananian 1.1.4.1 import harpoon.ClassFile.HField;
8 cananian 1.1.4.1 import harpoon.Util.HClassUtil;
9 cananian 1.6 import net.cscott.jutil.UnmodifiableListIterator;
10 cananian 1.1.4.1 import harpoon.Util.Util;
11 cananian 1.1.4.1
12 cananian 1.1.4.1 import java.util.AbstractSequentialList;
13 cananian 1.1.4.1 import java.util.HashMap;
14 cananian 1.1.4.1 import java.util.Iterator;
15 cananian 1.1.4.1 import java.util.List;
16 cananian 1.1.4.1 import java.util.ListIterator;
17 cananian 1.1.4.1 import java.util.Map;
18 cananian 1.1.4.1 import java.util.NoSuchElementException;
19 cananian 1.1.4.1 /**
20 cananian 1.1.4.1 * A <code>ClassFieldMap</code> is a <code>FieldMap</code> for
21 cananian 1.1.4.1 * non-static fields of a class. The user must implement a function
22 cananian 1.1.4.1 * giving the size of a field to complete the implementation.
23 cananian 1.1.4.1 * Results are cached for efficiency.
24 cananian 1.1.4.1 *
25 cananian 1.1.4.1 * @author C. Scott Ananian <cananian@alumni.princeton.edu>
26 cananian 1.7 * @version $Id: ClassFieldMap.java,v 1.7 2004/02/08 03:20:42 cananian Exp $
27 cananian 1.1.4.1 */
28 cananian 1.1.4.1 public abstract class ClassFieldMap extends harpoon.Backend.Maps.FieldMap {
29 cananian 1.1.4.1 /** Creates a <code>ClassFieldMap</code>. */
30 cananian 1.1.4.1 public ClassFieldMap() { /* no special initialization. */ }
31 cananian 1.1.4.2
32 cananian 1.1.4.1 // caching version of method inherited from superclass.
33 cananian 1.1.4.1 public int fieldOffset(HField hf) {
34 cananian 1.3.2.1 assert hf!=null && !hf.isStatic();
35 cananian 1.1.4.1 if (!cache.containsKey(hf)) {
36 cananian 1.1.4.1 int offset=0;
37 cananian 1.7 for (HField nexthf : fieldList(hf.getDeclaringClass())) {
38 cananian 1.1.4.2 int align = fieldAlignment(nexthf);
39 cananian 1.3.2.1 assert align>0;
40 cananian 1.1.4.2 if ((offset % align) != 0)
41 cananian 1.1.4.2 offset += align - (offset%align);
42 cananian 1.3.2.1 assert (offset % align) == 0;
43 cananian 1.1.4.1 if (!cache.containsKey(nexthf))
44 cananian 1.1.4.1 cache.put(nexthf, new Integer(offset));
45 cananian 1.1.4.1 offset+=fieldSize(nexthf);
46 cananian 1.1.4.1 }
47 cananian 1.1.4.1 }
48 cananian 1.3.2.1 assert cache.containsKey(hf) : hf+" not in fieldList()";
49 cananian 1.3.2.2 return cache.get(hf).intValue();
50 cananian 1.1.4.1 }
51 cananian 1.3.2.2 private final Map<HField,Integer> cache = new HashMap<HField,Integer>();
52 cananian 1.1.4.1
53 cananian 1.1.4.1 // the meat of this class: return non-static fields in order, from
54 cananian 1.1.4.1 // top-most superclass down.
55 cananian 1.3.2.2 public List<HField> fieldList(final HClass hc) {
56 cananian 1.3.2.1 assert hc!=null;
57 cananian 1.1.4.1 // first calculate size of list.
58 cananian 1.1.4.1 int n=0;
59 cananian 1.1.4.1 for (HClass hcp=hc; hcp!=null; hcp=hcp.getSuperclass()) {
60 cananian 1.1.4.3 HField[] fields = declaredFields(hcp);
61 cananian 1.1.4.1 for (int i=0; i<fields.length; i++)
62 cananian 1.1.4.1 if (!fields[i].isStatic()) n++;
63 cananian 1.1.4.1 }
64 cananian 1.1.4.1 final int size = n;
65 cananian 1.1.4.1 // now make & return list object.
66 cananian 1.3.2.2 return new AbstractSequentialList<HField>() {
67 cananian 1.1.4.1 public int size() { return size; }
68 cananian 1.3.2.2 public ListIterator<HField> listIterator(final int index) {
69 cananian 1.3.2.2 return new UnmodifiableListIterator<HField>() {
70 cananian 1.1.4.1 final HClass[] parents = HClassUtil.parents(hc);
71 cananian 1.1.4.1 HField[] fields;
72 cananian 1.1.4.1 int pindex, findex, xindex;
73 cananian 1.1.4.1 boolean done=true, forwards;
74 cananian 1.1.4.1 { // initialization code: count from beginning or end
75 cananian 1.1.4.1 // depending on which is closer.
76 cananian 1.1.4.1 if (index < size/2) { // count from beginning.
77 cananian 1.1.4.1 pindex=0;
78 cananian 1.1.4.3 fields = declaredFields(parents[pindex]);
79 cananian 1.1.4.1 findex=-1; forwards=true;
80 cananian 1.1.4.1 for (xindex=-1; xindex < index; xindex++)
81 cananian 1.1.4.1 advance();
82 cananian 1.1.4.1 } else { // count from end.
83 cananian 1.1.4.1 pindex = parents.length-1;
84 cananian 1.1.4.3 fields = declaredFields(parents[pindex]);
85 cananian 1.1.4.1 findex=fields.length; forwards=true;
86 cananian 1.1.4.1 for (xindex=size; xindex > index; xindex--)
87 cananian 1.1.4.1 retreat();
88 cananian 1.1.4.1 }
89 cananian 1.1.4.1 }
90 cananian 1.1.4.1 public boolean hasNext() {
91 cananian 1.1.4.1 if (!forwards) changeDirection();
92 cananian 1.1.4.1 return !done;
93 cananian 1.1.4.1 }
94 cananian 1.1.4.1 public boolean hasPrevious() {
95 cananian 1.1.4.1 if (forwards) changeDirection();
96 cananian 1.1.4.1 return !done;
97 cananian 1.1.4.1 }
98 cananian 1.3.2.2 public HField next() {
99 cananian 1.1.4.1 if (!forwards) changeDirection();
100 cananian 1.1.4.1 if (done) throw new NoSuchElementException();
101 cananian 1.1.4.1 xindex++;
102 cananian 1.1.4.1 HField hf = fields[findex]; advance(); return hf;
103 cananian 1.1.4.1 }
104 cananian 1.3.2.2 public HField previous() {
105 cananian 1.1.4.1 if (forwards) changeDirection();
106 cananian 1.1.4.1 if (done) throw new NoSuchElementException();
107 cananian 1.1.4.1 xindex--;
108 cananian 1.1.4.1 HField hf = fields[findex]; retreat(); return hf;
109 cananian 1.1.4.1 }
110 cananian 1.1.4.1 public int nextIndex() { return xindex; }
111 cananian 1.1.4.1 private void advance() {
112 cananian 1.1.4.1 done=false;
113 cananian 1.1.4.1 while (true) {
114 cananian 1.1.4.1 for (findex++; findex < fields.length; findex++)
115 cananian 1.1.4.1 if (!fields[findex].isStatic()) return;
116 cananian 1.1.4.1 if (++pindex >= parents.length) break;
117 cananian 1.1.4.3 fields = declaredFields(parents[pindex]);
118 cananian 1.1.4.1 findex = -1;
119 cananian 1.1.4.1 }
120 cananian 1.1.4.1 --pindex; done=true;
121 cananian 1.1.4.1 }
122 cananian 1.1.4.1 private void retreat() {
123 cananian 1.1.4.1 done=false;
124 cananian 1.1.4.1 while (true) {
125 cananian 1.1.4.1 for (findex--; findex >= 0; findex--)
126 cananian 1.1.4.1 if (!fields[findex].isStatic()) return;
127 cananian 1.1.4.1 if (--pindex < 0) break;
128 cananian 1.1.4.3 fields = declaredFields(parents[pindex]);
129 cananian 1.1.4.1 findex = fields.length;
130 cananian 1.1.4.1 }
131 cananian 1.1.4.1 ++pindex; done=true;
132 cananian 1.1.4.1 }
133 cananian 1.1.4.1 private void changeDirection() {
134 cananian 1.1.4.1 if (forwards) retreat(); else advance();
135 cananian 1.1.4.1 forwards = !forwards;
136 cananian 1.1.4.1 }
137 cananian 1.1.4.1 };
138 cananian 1.1.4.1 }
139 cananian 1.1.4.1 };
140 cananian 1.1.4.3 }
141 cananian 1.1.4.3 /** Return the declared fields of the specified class in the
142 cananian 1.1.4.3 * order in which they should be allocated. This implementation
143 cananian 1.1.4.3 * just returns the result of <code>hc.getDeclaredFields()</code>,
144 cananian 1.1.4.3 * but you can override this to use a more intelligent sorting
145 cananian 1.1.4.3 * routine to save space. You do not have to filter static methods
146 cananian 1.1.4.3 * out of the returned array, but you may if you like. */
147 cananian 1.1.4.3 protected HField[] declaredFields(HClass hc) {
148 cananian 1.1.4.3 return hc.getDeclaredFields();
149 cananian 1.1.4.1 }
150 cananian 1.2 }