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 related to migration of JDK classes.
241          */
242         MIGRATION("migration"),
243 
244         /**
245          * Warn about issues regarding module opens.
246          */
247         OPENS("opens"),
248 
249         /**
250          * Warn about issues relating to use of command line options
251          */
252         OPTIONS("options"),
253 
254         /**
255          * Warn when any output file is written to more than once.
256          */
257         OUTPUT_FILE_CLASH("output-file-clash"),
258 
259         /**
260          * Warn about issues regarding method overloads.
261          */
262         OVERLOADS("overloads"),
263 
264         /**
265          * Warn about issues regarding method overrides.
266          */
267         OVERRIDES("overrides"),
268 
269         /**
270          * Warn about invalid path elements on the command line.
271          * Such warnings cannot be suppressed with the SuppressWarnings
272          * annotation.
273          */
274         PATH("path"),
275 
276         /**
277          * Warn about issues regarding annotation processing.
278          */
279         PROCESSING("processing"),
280 
281         /**
282          * Warn about unchecked operations on raw types.
283          */
284         RAW("rawtypes"),
285 
286         /**
287          * Warn about use of deprecated-for-removal items.
288          */
289         REMOVAL("removal"),
290 
291         /**
292          * Warn about use of automatic modules in the requires clauses.
293          */
294         REQUIRES_AUTOMATIC("requires-automatic"),
295 
296         /**
297          * Warn about automatic modules in requires transitive.
298          */
299         REQUIRES_TRANSITIVE_AUTOMATIC("requires-transitive-automatic"),
300 
301         /**
302          * Warn about Serializable classes that do not provide a serial version ID.
303          */
304         SERIAL("serial"),
305 
306         /**
307          * Warn about issues relating to use of statics
308          */
309         STATIC("static"),
310 
311         /**
312          * Warn about unnecessary uses of the strictfp modifier
313          */
314         STRICTFP("strictfp"),
315 
316         /**
317          * Warn about synchronization attempts on instances of @ValueBased classes.
318          */
319         SYNCHRONIZATION("synchronization"),
320 
321         /**
322          * Warn about issues relating to use of text blocks
323          */
324         TEXT_BLOCKS("text-blocks"),
325 
326         /**
327          * Warn about possible 'this' escapes before subclass instance is fully initialized.
328          */
329         THIS_ESCAPE("this-escape"),
330 
331         /**
332          * Warn about issues relating to use of try blocks (i.e. try-with-resources)
333          */
334         TRY("try"),
335 
336         /**
337          * Warn about unchecked operations on raw types.
338          */
339         UNCHECKED("unchecked"),
340 
341         /**
342          * Warn about potentially unsafe vararg methods
343          */
344         VARARGS("varargs"),
345 
346         /**
347          * Warn about use of preview features.
348          */
349         PREVIEW("preview"),
350 
351         /**
352          * Warn about use of restricted methods.
353          */
354         RESTRICTED("restricted");
355 
356         LintCategory(String option) {
357             this(option, false);
358         }
359 
360         LintCategory(String option, boolean hidden) {
361             this.option = option;
362             this.hidden = hidden;
363             map.put(option, this);
364         }
365 
366         static LintCategory get(String option) {
367             return map.get(option);
368         }
369 
370         public final String option;
371         public final boolean hidden;
372     }
373 
374     /**
375      * Checks if a warning category is enabled. A warning category may be enabled
376      * on the command line, or by default, and can be temporarily disabled with
377      * the SuppressWarnings annotation.
378      */
379     public boolean isEnabled(LintCategory lc) {
380         return values.contains(lc);
381     }
382 
383     /**
384      * Checks is a warning category has been specifically suppressed, by means
385      * of the SuppressWarnings annotation, or, in the case of the deprecated
386      * category, whether it has been implicitly suppressed by virtue of the
387      * current entity being itself deprecated.
388      */
389     public boolean isSuppressed(LintCategory lc) {
390         return suppressedValues.contains(lc);
391     }
392 
393     protected static class AugmentVisitor implements Attribute.Visitor {
394         private final Context context;
395         private Symtab syms;
396         private Lint parent;
397         private Lint lint;
398 
399         AugmentVisitor(Context context) {
400             // to break an ugly sequence of initialization dependencies,
401             // we defer the initialization of syms until it is needed
402             this.context = context;
403         }
404 
405         Lint augment(Lint parent, Attribute.Compound attr) {
406             initSyms();
407             this.parent = parent;
408             lint = null;
409             attr.accept(this);
410             return (lint == null ? parent : lint);
411         }
412 
413         Lint augment(Lint parent, List<Attribute.Compound> attrs) {
414             initSyms();
415             this.parent = parent;
416             lint = null;
417             for (Attribute.Compound a: attrs) {
418                 a.accept(this);
419             }
420             return (lint == null ? parent : lint);
421         }
422 
423         private void initSyms() {
424             if (syms == null)
425                 syms = Symtab.instance(context);
426         }
427 
428         private void suppress(LintCategory lc) {
429             if (lint == null)
430                 lint = new Lint(parent);
431             lint.suppressedValues.add(lc);
432             lint.values.remove(lc);
433         }
434 
435         public void visitConstant(Attribute.Constant value) {
436             if (value.type.tsym == syms.stringType.tsym) {
437                 LintCategory lc = LintCategory.get((String) (value.value));
438                 if (lc != null)
439                     suppress(lc);
440             }
441         }
442 
443         public void visitClass(Attribute.Class clazz) {
444         }
445 
446         // If we find a @SuppressWarnings annotation, then we continue
447         // walking the tree, in order to suppress the individual warnings
448         // specified in the @SuppressWarnings annotation.
449         public void visitCompound(Attribute.Compound compound) {
450             if (compound.type.tsym == syms.suppressWarningsType.tsym) {
451                 for (List<Pair<MethodSymbol,Attribute>> v = compound.values;
452                      v.nonEmpty(); v = v.tail) {
453                     Pair<MethodSymbol,Attribute> value = v.head;
454                     if (value.fst.name.toString().equals("value"))
455                         value.snd.accept(this);
456                 }
457 
458             }
459         }
460 
461         public void visitArray(Attribute.Array array) {
462             for (Attribute value : array.values)
463                 value.accept(this);
464         }
465 
466         public void visitEnum(Attribute.Enum e) {
467         }
468 
469         public void visitError(Attribute.Error e) {
470         }
471     }
472 }
--- EOF ---