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