AttrContext.java revision 3711:3fc90eaaf922 
1/*
2 * Copyright (c) 1999, 2016, 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
26package com.sun.tools.javac.comp;
27
28import com.sun.tools.javac.tree.JCTree;
29import com.sun.tools.javac.util.*;
30import com.sun.tools.javac.code.*;
31import com.sun.tools.javac.code.Scope.WriteableScope;
32
33/** Contains information specific to the attribute and enter
34 *  passes, to be used in place of the generic field in environments.
35 *
36 *  <p><b>This is NOT part of any supported API.
37 *  If you write code that depends on this, you do so at your own risk.
38 *  This code and its internal interfaces are subject to change or
39 *  deletion without notice.</b>
40 */
41public class AttrContext {
42
43    /** The scope of local symbols.
44     */
45    WriteableScope scope = null;
46
47    /** The number of enclosing `static' modifiers.
48     */
49    int staticLevel = 0;
50
51    /** Is this an environment for a this(...) or super(...) call?
52     */
53    boolean isSelfCall = false;
54
55    /** Are we evaluating the selector of a `super' or type name?
56     */
57    boolean selectSuper = false;
58
59    /** Is the current target of lambda expression or method reference serializable or is this a
60     *  serializable class?
61     */
62    boolean isSerializable = false;
63
64    /** Is this a lambda environment?
65     */
66    boolean isLambda = false;
67
68    /** Is this a speculative attribution environment?
69     */
70    boolean isSpeculative = false;
71
72    /**
73     *  Is this an attribution environment for an anonymous class instantiated using <> ?
74     */
75    boolean isAnonymousDiamond = false;
76
77    /**
78     *  Is this an attribution environment for an instance creation expression?
79     */
80    boolean isNewClass = false;
81
82    /** Are arguments to current function applications boxed into an array for varargs?
83     */
84    Resolve.MethodResolutionPhase pendingResolutionPhase = null;
85
86    /** A record of the lint/SuppressWarnings currently in effect
87     */
88    Lint lint;
89
90    /** The variable whose initializer is being attributed
91     * useful for detecting self-references in variable initializers
92     */
93    Symbol enclVar = null;
94
95    /** ResultInfo to be used for attributing 'return' statement expressions
96     * (set by Attr.visitMethod and Attr.visitLambda)
97     */
98    Attr.ResultInfo returnResult = null;
99
100    /** Symbol corresponding to the site of a qualified default super call
101     */
102    Type defaultSuperCallSite = null;
103
104    /** Tree that when non null, is to be preferentially used in diagnostics.
105     *  Usually Env<AttrContext>.tree is the tree to be referred to in messages,
106     *  but this may not be true during the window a method is looked up in enclosing
107     *  contexts (JDK-8145466)
108     */
109    JCTree preferredTreeForDiagnostics;
110
111    /** Duplicate this context, replacing scope field and copying all others.
112     */
113    AttrContext dup(WriteableScope scope) {
114        AttrContext info = new AttrContext();
115        info.scope = scope;
116        info.staticLevel = staticLevel;
117        info.isSelfCall = isSelfCall;
118        info.selectSuper = selectSuper;
119        info.pendingResolutionPhase = pendingResolutionPhase;
120        info.lint = lint;
121        info.enclVar = enclVar;
122        info.returnResult = returnResult;
123        info.defaultSuperCallSite = defaultSuperCallSite;
124        info.isSerializable = isSerializable;
125        info.isLambda = isLambda;
126        info.isSpeculative = isSpeculative;
127        info.isAnonymousDiamond = isAnonymousDiamond;
128        info.isNewClass = isNewClass;
129        info.preferredTreeForDiagnostics = preferredTreeForDiagnostics;
130        return info;
131    }
132
133    /** Duplicate this context, copying all fields.
134     */
135    AttrContext dup() {
136        return dup(scope);
137    }
138
139    public Iterable<Symbol> getLocalElements() {
140        if (scope == null)
141            return List.nil();
142        return scope.getSymbols();
143    }
144
145    boolean lastResolveVarargs() {
146        return pendingResolutionPhase != null &&
147                pendingResolutionPhase.isVarargsRequired();
148    }
149
150    @Override
151    public String toString() {
152        return "AttrContext[" + scope.toString() + "]";
153    }
154}
155