1 /*
  2  * Copyright (c) 2005, 2022, 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 com.sun.tools.javac.code;
 27 
 28 import java.util.Arrays;
 29 import java.util.EnumSet;
 30 import java.util.Map;
 31 import java.util.concurrent.ConcurrentHashMap;
 32 
 33 import com.sun.tools.javac.code.Symbol.*;
 34 import com.sun.tools.javac.main.Option;
 35 import com.sun.tools.javac.util.Context;
 36 import com.sun.tools.javac.util.List;
 37 import com.sun.tools.javac.util.Options;
 38 import com.sun.tools.javac.util.Pair;
 39 
 40 /**
 41  * A class for handling -Xlint suboptions and @SuppressWarnings.
 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 public class Lint
 49 {
 50     /** The context key for the root Lint object. */
 51     protected static final Context.Key<Lint> lintKey = new Context.Key<>();
 52 
 53     /** Get the root Lint instance. */
 54     public static Lint instance(Context context) {
 55         Lint instance = context.get(lintKey);
 56         if (instance == null)
 57             instance = new Lint(context);
 58         return instance;
 59     }
 60 
 61     /**
 62      * Returns the result of combining the values in this object with
 63      * the given annotation.
 64      */
 65     public Lint augment(Attribute.Compound attr) {
 66         return augmentor.augment(this, attr);
 67     }
 68 
 69 
 70     /**
 71      * Returns the result of combining the values in this object with
 72      * the metadata on the given symbol.
 73      */
 74     public Lint augment(Symbol sym) {
 75         Lint l = augmentor.augment(this, sym.getDeclarationAttributes());
 76         if (sym.isDeprecated() && sym.isDeprecatableViaAnnotation()) {
 77             if (l == this)
 78                 l = new Lint(this);
 79             l.values.remove(LintCategory.DEPRECATION);
 80             l.suppressedValues.add(LintCategory.DEPRECATION);
 81         }
 82         return l;
 83     }
 84 
 85     /**
 86      * Returns a new Lint that has the given LintCategorys suppressed.
 87      * @param lc one or more categories to be suppressed
 88      */
 89     public Lint suppress(LintCategory... lc) {
 90         Lint l = new Lint(this);
 91         l.values.removeAll(Arrays.asList(lc));
 92         l.suppressedValues.addAll(Arrays.asList(lc));
 93         return l;
 94     }
 95 
 96     private final AugmentVisitor augmentor;
 97 
 98     private final EnumSet<LintCategory> values;
 99     private final EnumSet<LintCategory> suppressedValues;
100 
101     private static final Map<String, LintCategory> map = new ConcurrentHashMap<>(20);
102 
103     @SuppressWarnings("this-escape")
104     protected Lint(Context context) {
105         // initialize values according to the lint options
106         Options options = Options.instance(context);
107 
108         if (options.isSet(Option.XLINT) || options.isSet(Option.XLINT_CUSTOM, "all")) {
109             // If -Xlint or -Xlint:all is given, enable all categories by default
110             values = EnumSet.allOf(LintCategory.class);
111         } else if (options.isSet(Option.XLINT_CUSTOM, "none")) {
112             // if -Xlint:none is given, disable all categories by default
113             values = EnumSet.noneOf(LintCategory.class);
114         } else {
115             // otherwise, enable on-by-default categories
116             values = EnumSet.noneOf(LintCategory.class);
117 
118             Source source = Source.instance(context);
119             if (source.compareTo(Source.JDK9) >= 0) {
120                 values.add(LintCategory.DEP_ANN);
121             }
122             if (Source.Feature.REDUNDANT_STRICTFP.allowedInSource(source)) {
123                 values.add(LintCategory.STRICTFP);
124             }
125             values.add(LintCategory.REQUIRES_TRANSITIVE_AUTOMATIC);
126             values.add(LintCategory.OPENS);
127             values.add(LintCategory.MODULE);
128             values.add(LintCategory.REMOVAL);
129             if (!options.isSet(Option.PREVIEW)) {
130                 values.add(LintCategory.PREVIEW);
131             }
132             values.add(LintCategory.SYNCHRONIZATION);
133             values.add(LintCategory.INCUBATING);
134         }
135 
136         // Look for specific overrides
137         for (LintCategory lc : LintCategory.values()) {
138             if (options.isSet(Option.XLINT_CUSTOM, lc.option)) {
139                 values.add(lc);
140             } else if (options.isSet(Option.XLINT_CUSTOM, "-" + lc.option)) {
141                 values.remove(lc);
142             }
143         }
144 
145         suppressedValues = EnumSet.noneOf(LintCategory.class);
146 
147         context.put(lintKey, this);
148         augmentor = new AugmentVisitor(context);
149     }
150 
151     protected Lint(Lint other) {
152         this.augmentor = other.augmentor;
153         this.values = other.values.clone();
154         this.suppressedValues = other.suppressedValues.clone();
155     }
156 
157     @Override
158     public String toString() {
159         return "Lint:[values" + values + " suppressedValues" + suppressedValues + "]";
160     }
161 
162     /**
163      * Categories of warnings that can be generated by the compiler.
164      */
165     public enum LintCategory {
166         /**
167          * Warn when code refers to a auxiliary class that is hidden in a source file (ie source file name is
168          * different from the class name, and the type is not properly nested) and the referring code
169          * is not located in the same source file.
170          */
171         AUXILIARYCLASS("auxiliaryclass"),
172 
173         /**
174          * Warn about use of unnecessary casts.
175          */
176         CAST("cast"),
177 
178         /**
179          * Warn about issues related to classfile contents
180          */
181         CLASSFILE("classfile"),
182 
183         /**
184          * Warn about use of deprecated items.
185          */
186         DEPRECATION("deprecation"),
187 
188         /**
189          * Warn about items which are documented with an {@code @deprecated} JavaDoc
190          * comment, but which do not have {@code @Deprecated} annotation.
191          */
192         DEP_ANN("dep-ann"),
193 
194         /**
195          * Warn about division by constant integer 0.
196          */
197         DIVZERO("divzero"),
198 
199         /**
200          * Warn about empty statement after if.
201          */
202         EMPTY("empty"),
203 
204         /**
205          * Warn about issues regarding module exports.
206          */
207         EXPORTS("exports"),
208 
209         /**
210          * Warn about falling through from one case of a switch statement to the next.
211          */
212         FALLTHROUGH("fallthrough"),
213 
214         /**
215          * Warn about finally clauses that do not terminate normally.
216          */
217         FINALLY("finally"),
218 
219         /**
220          * Warn about use of incubating modules.
221          */
222         INCUBATING("incubating"),
223 
224         /**
225           * Warn about compiler possible lossy conversions.
226           */
227         LOSSY_CONVERSIONS("lossy-conversions"),
228 
229         /**
230           * Warn about compiler generation of a default constructor.
231           */
232         MISSING_EXPLICIT_CTOR("missing-explicit-ctor"),
233 
234         /**
235          * Warn about module system related issues.
236          */
237         MODULE("module"),
238 





239         /**
240          * Warn about issues regarding module opens.
241          */
242         OPENS("opens"),
243 
244         /**
245          * Warn about issues relating to use of command line options
246          */
247         OPTIONS("options"),
248 
249         /**
250          * Warn when any output file is written to more than once.
251          */
252         OUTPUT_FILE_CLASH("output-file-clash"),
253 
254         /**
255          * Warn about issues regarding method overloads.
256          */
257         OVERLOADS("overloads"),
258 
259         /**
260          * Warn about issues regarding method overrides.
261          */
262         OVERRIDES("overrides"),
263 
264         /**
265          * Warn about invalid path elements on the command line.
266          * Such warnings cannot be suppressed with the SuppressWarnings
267          * annotation.
268          */
269         PATH("path"),
270 
271         /**
272          * Warn about issues regarding annotation processing.
273          */
274         PROCESSING("processing"),
275 
276         /**
277          * Warn about unchecked operations on raw types.
278          */
279         RAW("rawtypes"),
280 
281         /**
282          * Warn about use of deprecated-for-removal items.
283          */
284         REMOVAL("removal"),
285 
286         /**
287          * Warn about use of automatic modules in the requires clauses.
288          */
289         REQUIRES_AUTOMATIC("requires-automatic"),
290 
291         /**
292          * Warn about automatic modules in requires transitive.
293          */
294         REQUIRES_TRANSITIVE_AUTOMATIC("requires-transitive-automatic"),
295 
296         /**
297          * Warn about Serializable classes that do not provide a serial version ID.
298          */
299         SERIAL("serial"),
300 
301         /**
302          * Warn about issues relating to use of statics
303          */
304         STATIC("static"),
305 
306         /**
307          * Warn about unnecessary uses of the strictfp modifier
308          */
309         STRICTFP("strictfp"),
310 
311         /**
312          * Warn about synchronization attempts on instances of @ValueBased classes.
313          */
314         SYNCHRONIZATION("synchronization"),
315 
316         /**
317          * Warn about issues relating to use of text blocks
318          */
319         TEXT_BLOCKS("text-blocks"),
320 
321         /**
322          * Warn about possible 'this' escapes before subclass instance is fully initialized.
323          */
324         THIS_ESCAPE("this-escape"),
325 
326         /**
327          * Warn about issues relating to use of try blocks (i.e. try-with-resources)
328          */
329         TRY("try"),
330 
331         /**
332          * Warn about unchecked operations on raw types.
333          */
334         UNCHECKED("unchecked"),
335 
336         /**
337          * Warn about potentially unsafe vararg methods
338          */
339         VARARGS("varargs"),
340 
341         /**
342          * Warn about use of preview features.
343          */
344         PREVIEW("preview"),
345 
346         /**
347          * Warn about use of restricted methods.
348          */
349         RESTRICTED("restricted");
350 
351         LintCategory(String option) {
352             this(option, false);
353         }
354 
355         LintCategory(String option, boolean hidden) {
356             this.option = option;
357             this.hidden = hidden;
358             map.put(option, this);
359         }
360 
361         static LintCategory get(String option) {
362             return map.get(option);
363         }
364 
365         public final String option;
366         public final boolean hidden;
367     }
368 
369     /**
370      * Checks if a warning category is enabled. A warning category may be enabled
371      * on the command line, or by default, and can be temporarily disabled with
372      * the SuppressWarnings annotation.
373      */
374     public boolean isEnabled(LintCategory lc) {
375         return values.contains(lc);
376     }
377 
378     /**
379      * Checks is a warning category has been specifically suppressed, by means
380      * of the SuppressWarnings annotation, or, in the case of the deprecated
381      * category, whether it has been implicitly suppressed by virtue of the
382      * current entity being itself deprecated.
383      */
384     public boolean isSuppressed(LintCategory lc) {
385         return suppressedValues.contains(lc);
386     }
387 
388     protected static class AugmentVisitor implements Attribute.Visitor {
389         private final Context context;
390         private Symtab syms;
391         private Lint parent;
392         private Lint lint;
393 
394         AugmentVisitor(Context context) {
395             // to break an ugly sequence of initialization dependencies,
396             // we defer the initialization of syms until it is needed
397             this.context = context;
398         }
399 
400         Lint augment(Lint parent, Attribute.Compound attr) {
401             initSyms();
402             this.parent = parent;
403             lint = null;
404             attr.accept(this);
405             return (lint == null ? parent : lint);
406         }
407 
408         Lint augment(Lint parent, List<Attribute.Compound> attrs) {
409             initSyms();
410             this.parent = parent;
411             lint = null;
412             for (Attribute.Compound a: attrs) {
413                 a.accept(this);
414             }
415             return (lint == null ? parent : lint);
416         }
417 
418         private void initSyms() {
419             if (syms == null)
420                 syms = Symtab.instance(context);
421         }
422 
423         private void suppress(LintCategory lc) {
424             if (lint == null)
425                 lint = new Lint(parent);
426             lint.suppressedValues.add(lc);
427             lint.values.remove(lc);
428         }
429 
430         public void visitConstant(Attribute.Constant value) {
431             if (value.type.tsym == syms.stringType.tsym) {
432                 LintCategory lc = LintCategory.get((String) (value.value));
433                 if (lc != null)
434                     suppress(lc);
435             }
436         }
437 
438         public void visitClass(Attribute.Class clazz) {
439         }
440 
441         // If we find a @SuppressWarnings annotation, then we continue
442         // walking the tree, in order to suppress the individual warnings
443         // specified in the @SuppressWarnings annotation.
444         public void visitCompound(Attribute.Compound compound) {
445             if (compound.type.tsym == syms.suppressWarningsType.tsym) {
446                 for (List<Pair<MethodSymbol,Attribute>> v = compound.values;
447                      v.nonEmpty(); v = v.tail) {
448                     Pair<MethodSymbol,Attribute> value = v.head;
449                     if (value.fst.name.toString().equals("value"))
450                         value.snd.accept(this);
451                 }
452 
453             }
454         }
455 
456         public void visitArray(Attribute.Array array) {
457             for (Attribute value : array.values)
458                 value.accept(this);
459         }
460 
461         public void visitEnum(Attribute.Enum e) {
462         }
463 
464         public void visitError(Attribute.Error e) {
465         }
466     }
467 }
--- EOF ---