1 /*
2 * Copyright (c) 2003, 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
26 package jdk.javadoc.internal.tool;
27
28 import com.sun.source.util.TreePath;
29 import com.sun.tools.javac.code.Flags;
30 import com.sun.tools.javac.code.Symbol.*;
31 import com.sun.tools.javac.comp.MemberEnter;
32 import com.sun.tools.javac.tree.JCTree;
33 import com.sun.tools.javac.tree.JCTree.*;
34 import com.sun.tools.javac.tree.TreeInfo;
35 import com.sun.tools.javac.util.Context;
36 import com.sun.tools.javac.util.List;
37 import com.sun.tools.javac.util.Names;
38
39 import static com.sun.tools.javac.code.Flags.*;
40 import static com.sun.tools.javac.code.Kinds.Kind.*;
41
42 /**
43 * Javadoc's own memberEnter phase does a few things above and beyond that
44 * done by javac.
45 *
46 * <p><b>This is NOT part of any supported API.
47 * If you write code that depends on this, you do so at your own risk.
48 * This code and its internal interfaces are subject to change or
49 * deletion without notice.</b>
50 *
51 * @author Neal Gafter
52 */
53 public class JavadocMemberEnter extends MemberEnter {
54 public static JavadocMemberEnter instance0(Context context) {
55 MemberEnter instance = context.get(memberEnterKey);
56 if (instance == null)
57 instance = new JavadocMemberEnter(context);
58 return (JavadocMemberEnter)instance;
59 }
60
61 public static void preRegister(Context context) {
62 context.put(memberEnterKey, (Context.Factory<MemberEnter>)JavadocMemberEnter::new);
63 }
64
65 final ToolEnvironment toolEnv;
66
67
68 protected JavadocMemberEnter(Context context) {
69 super(context);
70 toolEnv = ToolEnvironment.instance(context);
71 }
72
73 @Override
74 public void visitMethodDef(JCMethodDecl tree) {
75 super.visitMethodDef(tree);
76 MethodSymbol meth = tree.sym;
77 if (meth == null || meth.kind != MTH) return;
78 TreePath treePath = toolEnv.getTreePath(env.toplevel, env.enclClass, tree);
79 // do not add those methods that may be mandated by the spec,
80 // or those that are synthesized, thus if it does not exist in
81 // tree best to let other logic determine the TreePath.
82 if (env.enclClass.defs.contains(tree)) {
83 toolEnv.setElementToTreePath(meth, treePath);
84 }
85 // release resources
86 // handle constructors for record types specially, because of downstream checks
87 if ((env.enclClass.mods.flags & Flags.RECORD) != 0 && TreeInfo.isConstructor(tree)) {
88 tree.body.stats = List.nil();
89 } else {
90 tree.body = null;
91 }
92 }
93
94 @Override
95 public void visitVarDef(JCVariableDecl tree) {
96 if (tree.init != null) {
97 boolean isFinal = (tree.mods.flags & FINAL) != 0
98 || (env.enclClass.mods.flags & INTERFACE) != 0;
99 if (!isFinal || containsNonConstantExpression(tree.init)) {
100 // Avoid unnecessary analysis and release resources.
101 // In particular, remove non-constant expressions
102 // which may trigger Attr.attribClass, since
103 // method bodies are also removed, in visitMethodDef.
104 tree.init = null;
105 }
106 }
107 super.visitVarDef(tree);
108 if (tree.sym != null && tree.sym.kind == VAR && !isParameter(tree.sym)) {
109 toolEnv.setElementToTreePath(tree.sym, toolEnv.getTreePath(env.toplevel, env.enclClass, tree));
110 }
111 }
112
113 private static boolean isParameter(VarSymbol var) {
114 return (var.flags() & Flags.PARAMETER) != 0;
115 }
116
117 /**
118 * Simple analysis of an expression tree to see if it contains tree nodes
119 * for any non-constant expression. This does not include checking references
120 * to other fields which may or may not be constant.
121 */
122 private static boolean containsNonConstantExpression(JCExpression tree) {
123 return new MaybeConstantExpressionScanner().containsNonConstantExpression(tree);
124 }
125
126 /**
127 * See JLS 15.18, Constant Expression
128 */
129 private static class MaybeConstantExpressionScanner extends JCTree.Visitor {
130 boolean maybeConstantExpr = true;
131
132 public boolean containsNonConstantExpression(JCExpression tree) {
133 scan(tree);
134 return !maybeConstantExpr;
135 }
136
137 public void scan(JCTree tree) {
138 // short circuit scan when end result is definitely false
139 if (maybeConstantExpr && tree != null)
140 tree.accept(this);
141 }
142
143 @Override
144 /** default for any non-overridden visit method. */
145 public void visitTree(JCTree tree) {
146 maybeConstantExpr = false;
147 }
148
149 @Override
150 public void visitBinary(JCBinary tree) {
151 switch (tree.getTag()) {
152 case MUL: case DIV: case MOD:
153 case PLUS: case MINUS:
154 case SL: case SR: case USR:
155 case LT: case LE: case GT: case GE:
156 case EQ: case NE:
157 case BITAND: case BITXOR: case BITOR:
158 case AND: case OR:
159 break;
160 default:
161 maybeConstantExpr = false;
162 }
163 }
164
165 @Override
166 public void visitConditional(JCConditional tree) {
167 scan(tree.cond);
168 scan(tree.truepart);
169 scan(tree.falsepart);
170 }
171
172 @Override
173 public void visitIdent(JCIdent tree) { }
174
175 @Override
176 public void visitLiteral(JCLiteral tree) { }
177
178 @Override
179 public void visitParens(JCParens tree) {
180 scan(tree.expr);
181 }
182
183 @Override
184 public void visitSelect(JCTree.JCFieldAccess tree) {
185 scan(tree.selected);
186 }
187
188 @Override
189 public void visitTypeCast(JCTypeCast tree) {
190 scan(tree.clazz);
191 scan(tree.expr);
192 }
193
194 @Override
195 public void visitTypeIdent(JCPrimitiveTypeTree tree) { }
196
197 @Override
198 public void visitUnary(JCUnary tree) {
199 switch (tree.getTag()) {
200 case POS: case NEG: case COMPL: case NOT:
201 break;
202 default:
203 maybeConstantExpr = false;
204 }
205 }
206 }
207 }