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) 2005, 2010, 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 */
26 package com.sun.tools.javac.code;
28 import java.util.EnumSet;
29 import java.util.HashMap;
30 import java.util.Map;
31 import com.sun.tools.javac.code.Symbol.*;
32 import com.sun.tools.javac.util.Context;
33 import com.sun.tools.javac.util.List;
34 import com.sun.tools.javac.util.Options;
35 import com.sun.tools.javac.util.Pair;
36 import static com.sun.tools.javac.code.Flags.*;
39 /**
40 * A class for handling -Xlint suboptions and @SuppresssWarnings.
41 *
42 * <p><b>This is NOT part of any supported API.
43 * If you write code that depends on this, you do so at your own risk.
44 * This code and its internal interfaces are subject to change or
45 * deletion without notice.</b>
46 */
47 public class Lint
48 {
49 /** The context key for the root Lint object. */
50 protected static final Context.Key<Lint> lintKey = new Context.Key<Lint>();
52 /** Get the root Lint instance. */
53 public static Lint instance(Context context) {
54 Lint instance = context.get(lintKey);
55 if (instance == null)
56 instance = new Lint(context);
57 return instance;
58 }
60 /**
61 * Returns the result of combining the values in this object with
62 * the given annotation.
63 */
64 public Lint augment(Attribute.Compound attr) {
65 return augmentor.augment(this, attr);
66 }
69 /**
70 * Returns the result of combining the values in this object with
71 * the given annotations.
72 */
73 public Lint augment(List<Attribute.Compound> attrs) {
74 return augmentor.augment(this, attrs);
75 }
77 /**
78 * Returns the result of combining the values in this object with
79 * the given annotations and flags.
80 */
81 public Lint augment(List<Attribute.Compound> attrs, long flags) {
82 Lint l = augmentor.augment(this, attrs);
83 if ((flags & DEPRECATED) != 0) {
84 if (l == this)
85 l = new Lint(this);
86 l.values.remove(LintCategory.DEPRECATION);
87 l.suppressedValues.add(LintCategory.DEPRECATION);
88 }
89 return l;
90 }
93 private final AugmentVisitor augmentor;
95 private final EnumSet<LintCategory> values;
96 private final EnumSet<LintCategory> suppressedValues;
98 private static Map<String, LintCategory> map = new HashMap<String,LintCategory>();
101 protected Lint(Context context) {
102 // initialize values according to the lint options
103 Options options = Options.instance(context);
104 values = EnumSet.noneOf(LintCategory.class);
105 for (Map.Entry<String, LintCategory> e: map.entrySet()) {
106 if (options.lint(e.getKey()))
107 values.add(e.getValue());
108 }
110 suppressedValues = EnumSet.noneOf(LintCategory.class);
112 context.put(lintKey, this);
113 augmentor = new AugmentVisitor(context);
114 }
116 protected Lint(Lint other) {
117 this.augmentor = other.augmentor;
118 this.values = other.values.clone();
119 this.suppressedValues = other.suppressedValues.clone();
120 }
122 @Override
123 public String toString() {
124 return "Lint:[values" + values + " suppressedValues" + suppressedValues + "]";
125 }
127 /**
128 * Categories of warnings that can be generated by the compiler.
129 */
130 public enum LintCategory {
131 /**
132 * Warn about use of unnecessary casts.
133 */
134 CAST("cast"),
136 /**
137 * Warn about issues related to classfile contents
138 */
139 CLASSFILE("classfile"),
141 /**
142 * Warn about use of deprecated items.
143 */
144 DEPRECATION("deprecation"),
146 /**
147 * Warn about items which are documented with an {@code @deprecated} JavaDoc
148 * comment, but which do not have {@code @Deprecated} annotation.
149 */
150 DEP_ANN("dep-ann"),
152 /**
153 * Warn about division by constant integer 0.
154 */
155 DIVZERO("divzero"),
157 /**
158 * Warn about empty statement after if.
159 */
160 EMPTY("empty"),
162 /**
163 * Warn about falling through from one case of a switch statement to the next.
164 */
165 FALLTHROUGH("fallthrough"),
167 /**
168 * Warn about finally clauses that do not terminate normally.
169 */
170 FINALLY("finally"),
172 /**
173 * Warn about issues relating to use of command line options
174 */
175 OPTIONS("options"),
177 /**
178 * Warn about issues regarding method overrides.
179 */
180 OVERRIDES("overrides"),
182 /**
183 * Warn about invalid path elements on the command line.
184 * Such warnings cannot be suppressed with the SuppressWarnings
185 * annotation.
186 */
187 PATH("path"),
189 /**
190 * Warn about issues regarding annotation processing.
191 */
192 PROCESSING("processing"),
194 /**
195 * Warn about unchecked operations on raw types.
196 */
197 RAW("rawtypes"),
199 /**
200 * Warn about Serializable classes that do not provide a serial version ID.
201 */
202 SERIAL("serial"),
204 /**
205 * Warn about issues relating to use of statics
206 */
207 STATIC("static"),
209 /**
210 * Warn about proprietary API that may be removed in a future release.
211 */
212 SUNAPI("sunapi", true),
214 /**
215 * Warn about issues relating to use of try blocks (i.e. try-with-resources)
216 */
217 TRY("try"),
219 /**
220 * Warn about unchecked operations on raw types.
221 */
222 UNCHECKED("unchecked"),
224 /**
225 * Warn about potentially unsafe vararg methods
226 */
227 VARARGS("varargs");
229 LintCategory(String option) {
230 this(option, false);
231 }
233 LintCategory(String option, boolean hidden) {
234 this.option = option;
235 this.hidden = hidden;
236 map.put(option, this);
237 }
239 static LintCategory get(String option) {
240 return map.get(option);
241 }
243 public final String option;
244 public final boolean hidden;
245 };
247 /**
248 * Checks if a warning category is enabled. A warning category may be enabled
249 * on the command line, or by default, and can be temporarily disabled with
250 * the SuppressWarnings annotation.
251 */
252 public boolean isEnabled(LintCategory lc) {
253 return values.contains(lc);
254 }
256 /**
257 * Checks is a warning category has been specifically suppressed, by means
258 * of the SuppressWarnings annotation, or, in the case of the deprecated
259 * category, whether it has been implicitly suppressed by virtue of the
260 * current entity being itself deprecated.
261 */
262 public boolean isSuppressed(LintCategory lc) {
263 return suppressedValues.contains(lc);
264 }
266 protected static class AugmentVisitor implements Attribute.Visitor {
267 private final Context context;
268 private Symtab syms;
269 private Lint parent;
270 private Lint lint;
272 AugmentVisitor(Context context) {
273 // to break an ugly sequence of initialization dependencies,
274 // we defer the initialization of syms until it is needed
275 this.context = context;
276 }
278 Lint augment(Lint parent, Attribute.Compound attr) {
279 initSyms();
280 this.parent = parent;
281 lint = null;
282 attr.accept(this);
283 return (lint == null ? parent : lint);
284 }
286 Lint augment(Lint parent, List<Attribute.Compound> attrs) {
287 initSyms();
288 this.parent = parent;
289 lint = null;
290 for (Attribute.Compound a: attrs) {
291 a.accept(this);
292 }
293 return (lint == null ? parent : lint);
294 }
296 private void initSyms() {
297 if (syms == null)
298 syms = Symtab.instance(context);
299 }
301 private void suppress(LintCategory lc) {
302 if (lint == null)
303 lint = new Lint(parent);
304 lint.suppressedValues.add(lc);
305 lint.values.remove(lc);
306 }
308 public void visitConstant(Attribute.Constant value) {
309 if (value.type.tsym == syms.stringType.tsym) {
310 LintCategory lc = LintCategory.get((String) (value.value));
311 if (lc != null)
312 suppress(lc);
313 }
314 }
316 public void visitClass(Attribute.Class clazz) {
317 }
319 // If we find a @SuppressWarnings annotation, then we continue
320 // walking the tree, in order to suppress the individual warnings
321 // specified in the @SuppressWarnings annotation.
322 public void visitCompound(Attribute.Compound compound) {
323 if (compound.type.tsym == syms.suppressWarningsType.tsym) {
324 for (List<Pair<MethodSymbol,Attribute>> v = compound.values;
325 v.nonEmpty(); v = v.tail) {
326 Pair<MethodSymbol,Attribute> value = v.head;
327 if (value.fst.name.toString().equals("value"))
328 value.snd.accept(this);
329 }
331 }
332 }
334 public void visitArray(Attribute.Array array) {
335 for (Attribute value : array.values)
336 value.accept(this);
337 }
339 public void visitEnum(Attribute.Enum e) {
340 }
342 public void visitError(Attribute.Error e) {
343 }
344 };
345 }