Thu, 12 Jan 2012 15:28:34 +0000
7123100: javac fails with java.lang.StackOverflowError
Summary: Inference of under-constrained type-variables creates erroneous recursive wildcard types
Reviewed-by: jjg
1 /*
2 * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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10 *
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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).
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24 */
26 package com.sun.tools.javadoc;
29 import com.sun.javadoc.*;
31 import com.sun.tools.javac.code.Symbol.ClassSymbol;
32 import com.sun.tools.javac.code.Type;
33 import com.sun.tools.javac.util.List;
36 /**
37 * Implementation of <code>WildcardType</code>, which
38 * represents a wildcard type.
39 *
40 * @author Scott Seligman
41 * @since 1.5
42 */
43 public class WildcardTypeImpl extends AbstractTypeImpl implements WildcardType {
45 WildcardTypeImpl(DocEnv env, Type.WildcardType type) {
46 super(env, type);
47 }
49 /**
50 * Return the upper bounds of this wildcard type argument
51 * as given by the <i>extends</i> clause.
52 * Return an empty array if no such bounds are explicitly given.
53 */
54 public com.sun.javadoc.Type[] extendsBounds() {
55 return TypeMaker.getTypes(env, getExtendsBounds((Type.WildcardType)type));
56 }
58 /**
59 * Return the lower bounds of this wildcard type argument
60 * as given by the <i>super</i> clause.
61 * Return an empty array if no such bounds are explicitly given.
62 */
63 public com.sun.javadoc.Type[] superBounds() {
64 return TypeMaker.getTypes(env, getSuperBounds((Type.WildcardType)type));
65 }
67 /**
68 * Return the ClassDoc of the erasure of this wildcard type.
69 */
70 @Override
71 public ClassDoc asClassDoc() {
72 return env.getClassDoc((ClassSymbol)env.types.erasure(type).tsym);
73 }
75 @Override
76 public WildcardType asWildcardType() {
77 return this;
78 }
80 @Override
81 public String typeName() { return "?"; }
82 @Override
83 public String qualifiedTypeName() { return "?"; }
84 @Override
85 public String simpleTypeName() { return "?"; }
87 @Override
88 public String toString() {
89 return wildcardTypeToString(env, (Type.WildcardType)type, true);
90 }
93 /**
94 * Return the string form of a wildcard type ("?") along with any
95 * "extends" or "super" clause. Delimiting brackets are not
96 * included. Class names are qualified if "full" is true.
97 */
98 static String wildcardTypeToString(DocEnv env,
99 Type.WildcardType wildThing, boolean full) {
100 if (env.legacyDoclet) {
101 return TypeMaker.getTypeName(env.types.erasure(wildThing), full);
102 }
103 StringBuilder s = new StringBuilder("?");
104 List<Type> bounds = getExtendsBounds(wildThing);
105 if (bounds.nonEmpty()) {
106 s.append(" extends ");
107 } else {
108 bounds = getSuperBounds(wildThing);
109 if (bounds.nonEmpty()) {
110 s.append(" super ");
111 }
112 }
113 boolean first = true; // currently only one bound is allowed
114 for (Type b : bounds) {
115 if (!first) {
116 s.append(" & ");
117 }
118 s.append(TypeMaker.getTypeString(env, b, full));
119 first = false;
120 }
121 return s.toString();
122 }
124 private static List<Type> getExtendsBounds(Type.WildcardType wild) {
125 return wild.isSuperBound()
126 ? List.<Type>nil()
127 : List.of(wild.type);
128 }
130 private static List<Type> getSuperBounds(Type.WildcardType wild) {
131 return wild.isExtendsBound()
132 ? List.<Type>nil()
133 : List.of(wild.type);
134 }
135 }