1 /*
   2  * Copyright (c) 2005, 2017, 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()) {
  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     protected Lint(Context context) {
 104         // initialize values according to the lint options
 105         Options options = Options.instance(context);
 106 
 107         if (options.isSet(Option.XLINT) || options.isSet(Option.XLINT_CUSTOM, "all")) {
 108             // If -Xlint or -Xlint:all is given, enable all categories by default
 109             values = EnumSet.allOf(LintCategory.class);
 110         } else if (options.isSet(Option.XLINT_CUSTOM, "none")) {
 111             // if -Xlint:none is given, disable all categories by default
 112             values = EnumSet.noneOf(LintCategory.class);
 113         } else {
 114             // otherwise, enable on-by-default categories
 115             values = EnumSet.noneOf(LintCategory.class);
 116 
 117             Source source = Source.instance(context);
 118             if (source.compareTo(Source.JDK9) >= 0) {
 119                 values.add(LintCategory.DEP_ANN);
 120             }
 121             values.add(LintCategory.REQUIRES_TRANSITIVE_AUTOMATIC);
 122             values.add(LintCategory.OPENS);
 123             values.add(LintCategory.MODULE);
 124             values.add(LintCategory.REMOVAL);
 125             if (!options.isSet(Option.PREVIEW)) {
 126                 values.add(LintCategory.PREVIEW);
 127             }
 128         }
 129 
 130         // Look for specific overrides
 131         for (LintCategory lc : LintCategory.values()) {
 132             if (options.isSet(Option.XLINT_CUSTOM, lc.option)) {
 133                 values.add(lc);
 134             } else if (options.isSet(Option.XLINT_CUSTOM, "-" + lc.option)) {
 135                 values.remove(lc);
 136             }
 137         }
 138 
 139         suppressedValues = EnumSet.noneOf(LintCategory.class);
 140 
 141         context.put(lintKey, this);
 142         augmentor = new AugmentVisitor(context);
 143     }
 144 
 145     protected Lint(Lint other) {
 146         this.augmentor = other.augmentor;
 147         this.values = other.values.clone();
 148         this.suppressedValues = other.suppressedValues.clone();
 149     }
 150 
 151     @Override
 152     public String toString() {
 153         return "Lint:[values" + values + " suppressedValues" + suppressedValues + "]";
 154     }
 155 
 156     /**
 157      * Categories of warnings that can be generated by the compiler.
 158      */
 159     public enum LintCategory {
 160         /**
 161          * Warn when code refers to a auxiliary class that is hidden in a source file (ie source file name is
 162          * different from the class name, and the type is not properly nested) and the referring code
 163          * is not located in the same source file.
 164          */
 165         AUXILIARYCLASS("auxiliaryclass"),
 166 
 167         /**
 168          * Warn about use of unnecessary casts.
 169          */
 170         CAST("cast"),
 171 
 172         /**
 173          * Warn about issues related to classfile contents
 174          */
 175         CLASSFILE("classfile"),
 176 
 177         /**
 178          * Warn about use of deprecated items.
 179          */
 180         DEPRECATION("deprecation"),
 181 
 182         /**
 183          * Warn about items which are documented with an {@code @deprecated} JavaDoc
 184          * comment, but which do not have {@code @Deprecated} annotation.
 185          */
 186         DEP_ANN("dep-ann"),
 187 
 188         /**
 189          * Warn about division by constant integer 0.
 190          */
 191         DIVZERO("divzero"),
 192 
 193         /**
 194          * Warn about empty statement after if.
 195          */
 196         EMPTY("empty"),
 197 
 198         /**
 199          * Warn about issues regarding module exports.
 200          */
 201         EXPORTS("exports"),
 202 
 203         /**
 204          * Warn about falling through from one case of a switch statement to the next.
 205          */
 206         FALLTHROUGH("fallthrough"),
 207 
 208         /**
 209          * Warn about finally clauses that do not terminate normally.
 210          */
 211         FINALLY("finally"),
 212 
 213         /**
 214          * Warn about module system related issues.
 215          */
 216         MODULE("module"),
 217 
 218         /**
 219          * Warn about issues regarding module opens.
 220          */
 221         OPENS("opens"),
 222 
 223         /**
 224          * Warn about issues relating to use of command line options
 225          */
 226         OPTIONS("options"),
 227 
 228         /**
 229          * Warn about issues regarding method overloads.
 230          */
 231         OVERLOADS("overloads"),
 232 
 233         /**
 234          * Warn about issues regarding method overrides.
 235          */
 236         OVERRIDES("overrides"),
 237 
 238         /**
 239          * Warn about invalid path elements on the command line.
 240          * Such warnings cannot be suppressed with the SuppressWarnings
 241          * annotation.
 242          */
 243         PATH("path"),
 244 
 245         /**
 246          * Warn about issues regarding annotation processing.
 247          */
 248         PROCESSING("processing"),
 249 
 250         /**
 251          * Warn about unchecked operations on raw types.
 252          */
 253         RAW("rawtypes"),
 254 
 255         /**
 256          * Warn about use of deprecated-for-removal items.
 257          */
 258         REMOVAL("removal"),
 259 
 260         /**
 261          * Warn about use of automatic modules in the requires clauses.
 262          */
 263         REQUIRES_AUTOMATIC("requires-automatic"),
 264 
 265         /**
 266          * Warn about automatic modules in requires transitive.
 267          */
 268         REQUIRES_TRANSITIVE_AUTOMATIC("requires-transitive-automatic"),
 269 
 270         /**
 271          * Warn about Serializable classes that do not provide a serial version ID.
 272          */
 273         SERIAL("serial"),
 274 
 275         /**
 276          * Warn about issues relating to use of statics
 277          */
 278         STATIC("static"),
 279 
 280         /**
 281          * Warn about issues relating to use of text blocks
 282          */
 283         TEXT_BLOCKS("text-blocks"),
 284 
 285         /**
 286          * Warn about issues relating to use of try blocks (i.e. try-with-resources)
 287          */
 288         TRY("try"),
 289 
 290         /**
 291          * Warn about unchecked operations on raw types.
 292          */
 293         UNCHECKED("unchecked"),
 294 
 295         /**
 296          * Warn about potentially unsafe vararg methods
 297          */
 298         VARARGS("varargs"),
 299 
 300         /**
 301          * Warn about use of preview features.
 302          */
 303         PREVIEW("preview");
 304 
 305         LintCategory(String option) {
 306             this(option, false);
 307         }
 308 
 309         LintCategory(String option, boolean hidden) {
 310             this.option = option;
 311             this.hidden = hidden;
 312             map.put(option, this);
 313         }
 314 
 315         static LintCategory get(String option) {
 316             return map.get(option);
 317         }
 318 
 319         public final String option;
 320         public final boolean hidden;
 321     }
 322 
 323     /**
 324      * Checks if a warning category is enabled. A warning category may be enabled
 325      * on the command line, or by default, and can be temporarily disabled with
 326      * the SuppressWarnings annotation.
 327      */
 328     public boolean isEnabled(LintCategory lc) {
 329         return values.contains(lc);
 330     }
 331 
 332     /**
 333      * Checks is a warning category has been specifically suppressed, by means
 334      * of the SuppressWarnings annotation, or, in the case of the deprecated
 335      * category, whether it has been implicitly suppressed by virtue of the
 336      * current entity being itself deprecated.
 337      */
 338     public boolean isSuppressed(LintCategory lc) {
 339         return suppressedValues.contains(lc);
 340     }
 341 
 342     protected static class AugmentVisitor implements Attribute.Visitor {
 343         private final Context context;
 344         private Symtab syms;
 345         private Lint parent;
 346         private Lint lint;
 347 
 348         AugmentVisitor(Context context) {
 349             // to break an ugly sequence of initialization dependencies,
 350             // we defer the initialization of syms until it is needed
 351             this.context = context;
 352         }
 353 
 354         Lint augment(Lint parent, Attribute.Compound attr) {
 355             initSyms();
 356             this.parent = parent;
 357             lint = null;
 358             attr.accept(this);
 359             return (lint == null ? parent : lint);
 360         }
 361 
 362         Lint augment(Lint parent, List<Attribute.Compound> attrs) {
 363             initSyms();
 364             this.parent = parent;
 365             lint = null;
 366             for (Attribute.Compound a: attrs) {
 367                 a.accept(this);
 368             }
 369             return (lint == null ? parent : lint);
 370         }
 371 
 372         private void initSyms() {
 373             if (syms == null)
 374                 syms = Symtab.instance(context);
 375         }
 376 
 377         private void suppress(LintCategory lc) {
 378             if (lint == null)
 379                 lint = new Lint(parent);
 380             lint.suppressedValues.add(lc);
 381             lint.values.remove(lc);
 382         }
 383 
 384         public void visitConstant(Attribute.Constant value) {
 385             if (value.type.tsym == syms.stringType.tsym) {
 386                 LintCategory lc = LintCategory.get((String) (value.value));
 387                 if (lc != null)
 388                     suppress(lc);
 389             }
 390         }
 391 
 392         public void visitClass(Attribute.Class clazz) {
 393         }
 394 
 395         // If we find a @SuppressWarnings annotation, then we continue
 396         // walking the tree, in order to suppress the individual warnings
 397         // specified in the @SuppressWarnings annotation.
 398         public void visitCompound(Attribute.Compound compound) {
 399             if (compound.type.tsym == syms.suppressWarningsType.tsym) {
 400                 for (List<Pair<MethodSymbol,Attribute>> v = compound.values;
 401                      v.nonEmpty(); v = v.tail) {
 402                     Pair<MethodSymbol,Attribute> value = v.head;
 403                     if (value.fst.name.toString().equals("value"))
 404                         value.snd.accept(this);
 405                 }
 406 
 407             }
 408         }
 409 
 410         public void visitArray(Attribute.Array array) {
 411             for (Attribute value : array.values)
 412                 value.accept(this);
 413         }
 414 
 415         public void visitEnum(Attribute.Enum e) {
 416         }
 417 
 418         public void visitError(Attribute.Error e) {
 419         }
 420     }
 421 }