Wed, 09 Apr 2008 13:41:45 +0100
5009937: hiding versus generics versus binary compatibility
Summary: missing implementation of JLS 8.4.8.3 (different arguments with same erasure not always triggering a compiler error)
Reviewed-by: jjg
1 /*
2 * Copyright 2005 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
26 package com.sun.tools.javac.model;
28 import com.sun.tools.javac.util.*;
29 import java.util.AbstractList;
30 import java.util.Iterator;
31 import java.util.NoSuchElementException;
32 import com.sun.tools.javac.code.Scope;
33 import com.sun.tools.javac.code.Symbol;
35 import static com.sun.tools.javac.code.Flags.*;
37 /**
38 * Utility to construct a view of a symbol's members,
39 * filtering out unwanted elements such as synthetic ones.
40 * This view is most efficiently accessed through its iterator() method.
41 *
42 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
43 * you write code that depends on this, you do so at your own risk.
44 * This code and its internal interfaces are subject to change or
45 * deletion without notice.</b>
46 */
47 public class FilteredMemberList extends AbstractList<Symbol> {
49 private final Scope scope;
51 public FilteredMemberList(Scope scope) {
52 this.scope = scope;
53 }
55 public int size() {
56 int cnt = 0;
57 for (Scope.Entry e = scope.elems; e != null; e = e.sibling) {
58 if (!unwanted(e.sym))
59 cnt++;
60 }
61 return cnt;
62 }
64 public Symbol get(int index) {
65 for (Scope.Entry e = scope.elems; e != null; e = e.sibling) {
66 if (!unwanted(e.sym) && (index-- == 0))
67 return e.sym;
68 }
69 throw new IndexOutOfBoundsException();
70 }
72 // A more efficient implementation than AbstractList's.
73 public Iterator<Symbol> iterator() {
74 return new Iterator<Symbol>() {
76 /** The next entry to examine, or null if none. */
77 private Scope.Entry nextEntry = scope.elems;
79 private boolean hasNextForSure = false;
81 public boolean hasNext() {
82 if (hasNextForSure) {
83 return true;
84 }
85 while (nextEntry != null && unwanted(nextEntry.sym)) {
86 nextEntry = nextEntry.sibling;
87 }
88 hasNextForSure = (nextEntry != null);
89 return hasNextForSure;
90 }
92 public Symbol next() {
93 if (hasNext()) {
94 Symbol result = nextEntry.sym;
95 nextEntry = nextEntry.sibling;
96 hasNextForSure = false;
97 return result;
98 } else {
99 throw new NoSuchElementException();
100 }
101 }
103 public void remove() {
104 throw new UnsupportedOperationException();
105 }
106 };
107 }
109 /**
110 * Tests whether this is a symbol that should never be seen by
111 * clients, such as a synthetic class. Returns true for null.
112 */
113 private static boolean unwanted(Symbol s) {
114 return s == null || (s.flags() & SYNTHETIC) != 0;
115 }
116 }