1 /*
2 * Copyright (c) 2024, 2025, Oracle and/or its affiliates. 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.comp;
27
28 import java.util.HashMap;
29 import java.util.Map;
30 import java.util.Set;
31 import java.util.WeakHashMap;
32
33 import com.sun.tools.javac.util.List;
34
35 import com.sun.tools.javac.code.Symbol.ClassSymbol;
36 import com.sun.tools.javac.code.Symbol.VarSymbol;
37 import com.sun.tools.javac.tree.JCTree;
38 import com.sun.tools.javac.util.Context;
39
40 /**
41 * A Context class, that can keep useful information about unset fields.
42 * This information will be produced during flow analysis and used during
43 * code generation.
44 *
45 * <p><b>This is NOT part of any supported API.
46 * If you write code that depends on this, you do so at your own risk.
47 * This code and its internal interfaces are subject to change or
48 * deletion without notice.</b>
49 */
50 public class UnsetFieldsInfo {
51 protected static final Context.Key<UnsetFieldsInfo> unsetFieldsInfoKey = new Context.Key<>();
52
53 public static UnsetFieldsInfo instance(Context context) {
54 UnsetFieldsInfo instance = context.get(unsetFieldsInfoKey);
55 if (instance == null)
56 instance = new UnsetFieldsInfo(context);
57 return instance;
58 }
59
60 @SuppressWarnings("this-escape")
61 protected UnsetFieldsInfo(Context context) {
62 context.put(unsetFieldsInfoKey, this);
63 }
64
65 private WeakHashMap<ClassSymbol, Map<JCTree, Set<VarSymbol>>> unsetFieldsMap = new WeakHashMap<>();
66
67 public void addUnsetFieldsInfo(ClassSymbol csym, JCTree tree, Set<VarSymbol> unsetFields) {
68 Map<JCTree, Set<VarSymbol>> treeToFieldsMap = unsetFieldsMap.get(csym);
69 if (treeToFieldsMap == null) {
70 treeToFieldsMap = new HashMap<>();
71 treeToFieldsMap.put(tree, unsetFields);
72 unsetFieldsMap.put(csym, treeToFieldsMap);
73 } else {
74 if (!treeToFieldsMap.containsKey(tree)) {
75 // only add if there is no info for the given tree
76 treeToFieldsMap.put(tree, unsetFields);
77 }
78 }
79 }
80
81 public Set<VarSymbol> getUnsetFields(ClassSymbol csym, JCTree tree) {
82 Map<JCTree, Set<VarSymbol>> treeToFieldsMap = unsetFieldsMap.get(csym);
83 if (treeToFieldsMap != null) {
84 Set<VarSymbol> result = treeToFieldsMap.get(tree);
85 if (result != null) {
86 return result;
87 }
88 }
89 return null;
90 }
91
92 public void removeUnsetFieldInfo(ClassSymbol csym, JCTree tree) {
93 Map<JCTree, Set<VarSymbol>> treeToFieldsMap = unsetFieldsMap.get(csym);
94 if (treeToFieldsMap != null) {
95 treeToFieldsMap.remove(tree);
96 }
97 }
98 }