1 /*
2 * Copyright (c) 1999, 2025, 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.comp;
27
28 import java.util.*;
29 import java.util.function.BiConsumer;
30 import java.util.function.BiPredicate;
31 import java.util.function.Function;
32 import java.util.function.Predicate;
33 import java.util.function.Supplier;
34 import java.util.function.ToIntBiFunction;
35 import java.util.stream.Collectors;
36 import java.util.stream.StreamSupport;
37
38 import javax.lang.model.element.ElementKind;
39 import javax.lang.model.element.NestingKind;
40 import javax.tools.JavaFileManager;
41
42 import com.sun.source.tree.CaseTree;
43 import com.sun.tools.javac.code.*;
44 import com.sun.tools.javac.code.Attribute.Compound;
45 import com.sun.tools.javac.code.Directive.ExportsDirective;
46 import com.sun.tools.javac.code.Directive.RequiresDirective;
47 import com.sun.tools.javac.code.Source.Feature;
48 import com.sun.tools.javac.comp.Annotate.AnnotationTypeMetadata;
49 import com.sun.tools.javac.jvm.*;
50 import com.sun.tools.javac.resources.CompilerProperties;
51 import com.sun.tools.javac.resources.CompilerProperties.Errors;
52 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
53 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
54 import com.sun.tools.javac.resources.CompilerProperties.LintWarnings;
55 import com.sun.tools.javac.tree.*;
56 import com.sun.tools.javac.util.*;
57 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
58 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
59 import com.sun.tools.javac.util.JCDiagnostic.Error;
60 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
61 import com.sun.tools.javac.util.JCDiagnostic.LintWarning;
62 import com.sun.tools.javac.util.List;
63
64 import com.sun.tools.javac.code.Lint;
65 import com.sun.tools.javac.code.Lint.LintCategory;
66 import com.sun.tools.javac.code.Scope.WriteableScope;
67 import com.sun.tools.javac.code.Type.*;
68 import com.sun.tools.javac.code.Symbol.*;
69 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
70 import com.sun.tools.javac.tree.JCTree.*;
71
72 import static com.sun.tools.javac.code.Flags.*;
73 import static com.sun.tools.javac.code.Flags.ANNOTATION;
74 import static com.sun.tools.javac.code.Flags.SYNCHRONIZED;
75 import static com.sun.tools.javac.code.Kinds.*;
76 import static com.sun.tools.javac.code.Kinds.Kind.*;
77 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
78 import static com.sun.tools.javac.code.Scope.LookupKind.RECURSIVE;
79 import static com.sun.tools.javac.code.TypeTag.*;
80 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
81
82 import static com.sun.tools.javac.tree.JCTree.Tag.*;
83 import javax.lang.model.element.Element;
84 import javax.lang.model.element.TypeElement;
85 import javax.lang.model.type.DeclaredType;
86 import javax.lang.model.util.ElementKindVisitor14;
87
88 /** Type checking helper class for the attribution phase.
89 *
90 * <p><b>This is NOT part of any supported API.
91 * If you write code that depends on this, you do so at your own risk.
92 * This code and its internal interfaces are subject to change or
93 * deletion without notice.</b>
94 */
95 public class Check {
96 protected static final Context.Key<Check> checkKey = new Context.Key<>();
97
98 // Flag bits indicating which item(s) chosen from a pair of items
99 private static final int FIRST = 0x01;
100 private static final int SECOND = 0x02;
101
102 private final Names names;
103 private final Log log;
104 private final Resolve rs;
105 private final Symtab syms;
106 private final Enter enter;
107 private final DeferredAttr deferredAttr;
108 private final Infer infer;
109 private final Types types;
110 private final TypeAnnotations typeAnnotations;
111 private final JCDiagnostic.Factory diags;
112 private final JavaFileManager fileManager;
113 private final Source source;
114 private final Target target;
115 private final Profile profile;
116 private final Preview preview;
117 private final boolean warnOnAnyAccessToMembers;
118
119 public boolean disablePreviewCheck;
120
121 // The set of lint options currently in effect. It is initialized
122 // from the context, and then is set/reset as needed by Attr as it
123 // visits all the various parts of the trees during attribution.
124 Lint lint;
125
126 // The method being analyzed in Attr - it is set/reset as needed by
127 // Attr as it visits new method declarations.
128 private MethodSymbol method;
129
130 public static Check instance(Context context) {
131 Check instance = context.get(checkKey);
132 if (instance == null)
133 instance = new Check(context);
134 return instance;
135 }
136
137 @SuppressWarnings("this-escape")
138 protected Check(Context context) {
139 context.put(checkKey, this);
140
141 names = Names.instance(context);
142 log = Log.instance(context);
143 rs = Resolve.instance(context);
144 syms = Symtab.instance(context);
145 enter = Enter.instance(context);
146 deferredAttr = DeferredAttr.instance(context);
147 infer = Infer.instance(context);
148 types = Types.instance(context);
149 typeAnnotations = TypeAnnotations.instance(context);
150 diags = JCDiagnostic.Factory.instance(context);
151 Options options = Options.instance(context);
152 lint = Lint.instance(context);
153 fileManager = context.get(JavaFileManager.class);
154
155 source = Source.instance(context);
156 target = Target.instance(context);
157 warnOnAnyAccessToMembers = options.isSet("warnOnAccessToMembers");
158
159 disablePreviewCheck = false;
160
161 Target target = Target.instance(context);
162 syntheticNameChar = target.syntheticNameChar();
163
164 profile = Profile.instance(context);
165 preview = Preview.instance(context);
166
167 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
168 boolean verboseRemoval = lint.isEnabled(LintCategory.REMOVAL);
169 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
170 boolean enforceMandatoryWarnings = true;
171
172 deprecationHandler = new MandatoryWarningHandler(log, null, verboseDeprecated,
173 enforceMandatoryWarnings, LintCategory.DEPRECATION, "deprecated");
174 removalHandler = new MandatoryWarningHandler(log, null, verboseRemoval,
175 enforceMandatoryWarnings, LintCategory.REMOVAL);
176 uncheckedHandler = new MandatoryWarningHandler(log, null, verboseUnchecked,
177 enforceMandatoryWarnings, LintCategory.UNCHECKED);
178
179 deferredLintHandler = DeferredLintHandler.instance(context);
180
181 allowModules = Feature.MODULES.allowedInSource(source);
182 allowRecords = Feature.RECORDS.allowedInSource(source);
183 allowSealed = Feature.SEALED_CLASSES.allowedInSource(source);
184 }
185
186 /** Character for synthetic names
187 */
188 char syntheticNameChar;
189
190 /** A table mapping flat names of all compiled classes for each module in this run
191 * to their symbols; maintained from outside.
192 */
193 private Map<Pair<ModuleSymbol, Name>,ClassSymbol> compiled = new HashMap<>();
194
195 /** A handler for messages about deprecated usage.
196 */
197 private MandatoryWarningHandler deprecationHandler;
198
199 /** A handler for messages about deprecated-for-removal usage.
200 */
201 private MandatoryWarningHandler removalHandler;
202
203 /** A handler for messages about unchecked or unsafe usage.
204 */
205 private MandatoryWarningHandler uncheckedHandler;
206
207 /** A handler for deferred lint warnings.
208 */
209 private DeferredLintHandler deferredLintHandler;
210
211 /** Are modules allowed
212 */
213 private final boolean allowModules;
214
215 /** Are records allowed
216 */
217 private final boolean allowRecords;
218
219 /** Are sealed classes allowed
220 */
221 private final boolean allowSealed;
222
223 /** Whether to force suppression of deprecation and preview warnings.
224 * This happens when attributing import statements for JDK 9+.
225 * @see Feature#DEPRECATION_ON_IMPORT
226 */
227 private boolean importSuppression;
228
229 /* *************************************************************************
230 * Errors and Warnings
231 **************************************************************************/
232
233 Lint setLint(Lint newLint) {
234 Lint prev = lint;
235 lint = newLint;
236 return prev;
237 }
238
239 boolean setImportSuppression(boolean newImportSuppression) {
240 boolean prev = importSuppression;
241 importSuppression = newImportSuppression;
242 return prev;
243 }
244
245 MethodSymbol setMethod(MethodSymbol newMethod) {
246 MethodSymbol prev = method;
247 method = newMethod;
248 return prev;
249 }
250
251 /** Warn about deprecated symbol.
252 * @param pos Position to be used for error reporting.
253 * @param sym The deprecated symbol.
254 */
255 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
256 if (sym.isDeprecatedForRemoval()) {
257 if (!lint.isSuppressed(LintCategory.REMOVAL)) {
258 if (sym.kind == MDL) {
259 removalHandler.report(pos, LintWarnings.HasBeenDeprecatedForRemovalModule(sym));
260 } else {
261 removalHandler.report(pos, LintWarnings.HasBeenDeprecatedForRemoval(sym, sym.location()));
262 }
263 }
264 } else if (!lint.isSuppressed(LintCategory.DEPRECATION)) {
265 if (sym.kind == MDL) {
266 deprecationHandler.report(pos, LintWarnings.HasBeenDeprecatedModule(sym));
267 } else {
268 deprecationHandler.report(pos, LintWarnings.HasBeenDeprecated(sym, sym.location()));
269 }
270 }
271 }
272
273 /** Log a preview warning.
274 * @param pos Position to be used for error reporting.
275 * @param msg A Warning describing the problem.
276 */
277 public void warnPreviewAPI(DiagnosticPosition pos, LintWarning warnKey) {
278 if (!importSuppression && !lint.isSuppressed(LintCategory.PREVIEW))
279 preview.reportPreviewWarning(pos, warnKey);
280 }
281
282 /** Log a preview warning.
283 * @param pos Position to be used for error reporting.
284 * @param msg A Warning describing the problem.
285 */
286 public void warnRestrictedAPI(DiagnosticPosition pos, Symbol sym) {
287 lint.logIfEnabled(pos, LintWarnings.RestrictedMethod(sym.enclClass(), sym));
288 }
289
290 /** Warn about unchecked operation.
291 * @param pos Position to be used for error reporting.
292 * @param msg A string describing the problem.
293 */
294 public void warnUnchecked(DiagnosticPosition pos, LintWarning warnKey) {
295 if (!lint.isSuppressed(LintCategory.UNCHECKED))
296 uncheckedHandler.report(pos, warnKey);
297 }
298
299 /**
300 * Report any deferred diagnostics.
301 */
302 public void reportDeferredDiagnostics() {
303 deprecationHandler.reportDeferredDiagnostic();
304 removalHandler.reportDeferredDiagnostic();
305 uncheckedHandler.reportDeferredDiagnostic();
306 }
307
308
309 /** Report a failure to complete a class.
310 * @param pos Position to be used for error reporting.
311 * @param ex The failure to report.
312 */
313 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
314 log.error(JCDiagnostic.DiagnosticFlag.NON_DEFERRABLE, pos, Errors.CantAccess(ex.sym, ex.getDetailValue()));
315 return syms.errType;
316 }
317
318 /** Report an error that wrong type tag was found.
319 * @param pos Position to be used for error reporting.
320 * @param required An internationalized string describing the type tag
321 * required.
322 * @param found The type that was found.
323 */
324 Type typeTagError(DiagnosticPosition pos, JCDiagnostic required, Object found) {
325 // this error used to be raised by the parser,
326 // but has been delayed to this point:
327 if (found instanceof Type type && type.hasTag(VOID)) {
328 log.error(pos, Errors.IllegalStartOfType);
329 return syms.errType;
330 }
331 log.error(pos, Errors.TypeFoundReq(found, required));
332 return types.createErrorType(found instanceof Type type ? type : syms.errType);
333 }
334
335 /** Report duplicate declaration error.
336 */
337 void duplicateError(DiagnosticPosition pos, Symbol sym) {
338 if (!sym.type.isErroneous()) {
339 Symbol location = sym.location();
340 if (location.kind == MTH &&
341 ((MethodSymbol)location).isStaticOrInstanceInit()) {
342 log.error(pos,
343 Errors.AlreadyDefinedInClinit(kindName(sym),
344 sym,
345 kindName(sym.location()),
346 kindName(sym.location().enclClass()),
347 sym.location().enclClass()));
348 } else {
349 /* dont error if this is a duplicated parameter of a generated canonical constructor
350 * as we should have issued an error for the duplicated fields
351 */
352 if (location.kind != MTH ||
353 ((sym.owner.flags_field & GENERATEDCONSTR) == 0) ||
354 ((sym.owner.flags_field & RECORD) == 0)) {
355 log.error(pos,
356 Errors.AlreadyDefined(kindName(sym),
357 sym,
358 kindName(sym.location()),
359 sym.location()));
360 }
361 }
362 }
363 }
364
365 /** Report array/varargs duplicate declaration
366 */
367 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
368 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
369 log.error(pos, Errors.ArrayAndVarargs(sym1, sym2, sym2.location()));
370 }
371 }
372
373 /* ************************************************************************
374 * duplicate declaration checking
375 *************************************************************************/
376
377 /** Check that variable does not hide variable with same name in
378 * immediately enclosing local scope.
379 * @param pos Position for error reporting.
380 * @param v The symbol.
381 * @param s The scope.
382 */
383 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
384 for (Symbol sym : s.getSymbolsByName(v.name)) {
385 if (sym.owner != v.owner) break;
386 if (sym.kind == VAR &&
387 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
388 v.name != names.error) {
389 duplicateError(pos, sym);
390 return;
391 }
392 }
393 }
394
395 /** Check that a class or interface does not hide a class or
396 * interface with same name in immediately enclosing local scope.
397 * @param pos Position for error reporting.
398 * @param c The symbol.
399 * @param s The scope.
400 */
401 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
402 for (Symbol sym : s.getSymbolsByName(c.name)) {
403 if (sym.owner != c.owner) break;
404 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR) &&
405 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
406 c.name != names.error) {
407 duplicateError(pos, sym);
408 return;
409 }
410 }
411 }
412
413 /** Check that class does not have the same name as one of
414 * its enclosing classes, or as a class defined in its enclosing scope.
415 * return true if class is unique in its enclosing scope.
416 * @param pos Position for error reporting.
417 * @param name The class name.
418 * @param s The enclosing scope.
419 */
420 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
421 for (Symbol sym : s.getSymbolsByName(name, NON_RECURSIVE)) {
422 if (sym.kind == TYP && sym.name != names.error) {
423 duplicateError(pos, sym);
424 return false;
425 }
426 }
427 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
428 if (sym.kind == TYP && sym.name == name && sym.name != names.error &&
429 !sym.isImplicit()) {
430 duplicateError(pos, sym);
431 return true;
432 }
433 }
434 return true;
435 }
436
437 /* *************************************************************************
438 * Class name generation
439 **************************************************************************/
440
441
442 private Map<Pair<Name, Name>, Integer> localClassNameIndexes = new HashMap<>();
443
444 /** Return name of local class.
445 * This is of the form {@code <enclClass> $ n <classname> }
446 * where
447 * enclClass is the flat name of the enclosing class,
448 * classname is the simple name of the local class
449 */
450 public Name localClassName(ClassSymbol c) {
451 Name enclFlatname = c.owner.enclClass().flatname;
452 String enclFlatnameStr = enclFlatname.toString();
453 Pair<Name, Name> key = new Pair<>(enclFlatname, c.name);
454 Integer index = localClassNameIndexes.get(key);
455 for (int i = (index == null) ? 1 : index; ; i++) {
456 Name flatname = names.fromString(enclFlatnameStr
457 + syntheticNameChar + i + c.name);
458 if (getCompiled(c.packge().modle, flatname) == null) {
459 localClassNameIndexes.put(key, i + 1);
460 return flatname;
461 }
462 }
463 }
464
465 public void clearLocalClassNameIndexes(ClassSymbol c) {
466 if (c.owner != null && c.owner.kind != NIL) {
467 localClassNameIndexes.remove(new Pair<>(
468 c.owner.enclClass().flatname, c.name));
469 }
470 }
471
472 public void newRound() {
473 compiled.clear();
474 localClassNameIndexes.clear();
475 }
476
477 public void clear() {
478 deprecationHandler.clear();
479 removalHandler.clear();
480 uncheckedHandler.clear();
481 }
482
483 public void putCompiled(ClassSymbol csym) {
484 compiled.put(Pair.of(csym.packge().modle, csym.flatname), csym);
485 }
486
487 public ClassSymbol getCompiled(ClassSymbol csym) {
488 return compiled.get(Pair.of(csym.packge().modle, csym.flatname));
489 }
490
491 public ClassSymbol getCompiled(ModuleSymbol msym, Name flatname) {
492 return compiled.get(Pair.of(msym, flatname));
493 }
494
495 public void removeCompiled(ClassSymbol csym) {
496 compiled.remove(Pair.of(csym.packge().modle, csym.flatname));
497 }
498
499 /* *************************************************************************
500 * Type Checking
501 **************************************************************************/
502
503 /**
504 * A check context is an object that can be used to perform compatibility
505 * checks - depending on the check context, meaning of 'compatibility' might
506 * vary significantly.
507 */
508 public interface CheckContext {
509 /**
510 * Is type 'found' compatible with type 'req' in given context
511 */
512 boolean compatible(Type found, Type req, Warner warn);
513 /**
514 * Report a check error
515 */
516 void report(DiagnosticPosition pos, JCDiagnostic details);
517 /**
518 * Obtain a warner for this check context
519 */
520 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req);
521
522 public InferenceContext inferenceContext();
523
524 public DeferredAttr.DeferredAttrContext deferredAttrContext();
525 }
526
527 /**
528 * This class represent a check context that is nested within another check
529 * context - useful to check sub-expressions. The default behavior simply
530 * redirects all method calls to the enclosing check context leveraging
531 * the forwarding pattern.
532 */
533 static class NestedCheckContext implements CheckContext {
534 CheckContext enclosingContext;
535
536 NestedCheckContext(CheckContext enclosingContext) {
537 this.enclosingContext = enclosingContext;
538 }
539
540 public boolean compatible(Type found, Type req, Warner warn) {
541 return enclosingContext.compatible(found, req, warn);
542 }
543
544 public void report(DiagnosticPosition pos, JCDiagnostic details) {
545 enclosingContext.report(pos, details);
546 }
547
548 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
549 return enclosingContext.checkWarner(pos, found, req);
550 }
551
552 public InferenceContext inferenceContext() {
553 return enclosingContext.inferenceContext();
554 }
555
556 public DeferredAttrContext deferredAttrContext() {
557 return enclosingContext.deferredAttrContext();
558 }
559 }
560
561 /**
562 * Check context to be used when evaluating assignment/return statements
563 */
564 CheckContext basicHandler = new CheckContext() {
565 public void report(DiagnosticPosition pos, JCDiagnostic details) {
566 log.error(pos, Errors.ProbFoundReq(details));
567 }
568 public boolean compatible(Type found, Type req, Warner warn) {
569 return types.isAssignable(found, req, warn);
570 }
571
572 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
573 return convertWarner(pos, found, req);
574 }
575
576 public InferenceContext inferenceContext() {
577 return infer.emptyContext;
578 }
579
580 public DeferredAttrContext deferredAttrContext() {
581 return deferredAttr.emptyDeferredAttrContext;
582 }
583
584 @Override
585 public String toString() {
586 return "CheckContext: basicHandler";
587 }
588 };
589
590 /** Check that a given type is assignable to a given proto-type.
591 * If it is, return the type, otherwise return errType.
592 * @param pos Position to be used for error reporting.
593 * @param found The type that was found.
594 * @param req The type that was required.
595 */
596 public Type checkType(DiagnosticPosition pos, Type found, Type req) {
597 return checkType(pos, found, req, basicHandler);
598 }
599
600 Type checkType(final DiagnosticPosition pos, final Type found, final Type req, final CheckContext checkContext) {
601 final InferenceContext inferenceContext = checkContext.inferenceContext();
602 if (inferenceContext.free(req) || inferenceContext.free(found)) {
603 inferenceContext.addFreeTypeListener(List.of(req, found),
604 solvedContext -> checkType(pos, solvedContext.asInstType(found), solvedContext.asInstType(req), checkContext));
605 }
606 if (req.hasTag(ERROR))
607 return req;
608 if (req.hasTag(NONE))
609 return found;
610 if (checkContext.compatible(found, req, checkContext.checkWarner(pos, found, req))) {
611 return found;
612 } else {
613 if (found.isNumeric() && req.isNumeric()) {
614 checkContext.report(pos, diags.fragment(Fragments.PossibleLossOfPrecision(found, req)));
615 return types.createErrorType(found);
616 }
617 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
618 return types.createErrorType(found);
619 }
620 }
621
622 /** Check that a given type can be cast to a given target type.
623 * Return the result of the cast.
624 * @param pos Position to be used for error reporting.
625 * @param found The type that is being cast.
626 * @param req The target type of the cast.
627 */
628 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
629 return checkCastable(pos, found, req, basicHandler);
630 }
631 Type checkCastable(DiagnosticPosition pos, Type found, Type req, CheckContext checkContext) {
632 if (types.isCastable(found, req, castWarner(pos, found, req))) {
633 return req;
634 } else {
635 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
636 return types.createErrorType(found);
637 }
638 }
639
640 /** Check for redundant casts (i.e. where source type is a subtype of target type)
641 * The problem should only be reported for non-292 cast
642 */
643 public void checkRedundantCast(Env<AttrContext> env, final JCTypeCast tree) {
644 if (!tree.type.isErroneous()
645 && types.isSameType(tree.expr.type, tree.clazz.type)
646 && !(ignoreAnnotatedCasts && TreeInfo.containsTypeAnnotation(tree.clazz))
647 && !is292targetTypeCast(tree)) {
648 deferredLintHandler.report(_l -> {
649 lint.logIfEnabled(tree.pos(), LintWarnings.RedundantCast(tree.clazz.type));
650 });
651 }
652 }
653 //where
654 private boolean is292targetTypeCast(JCTypeCast tree) {
655 boolean is292targetTypeCast = false;
656 JCExpression expr = TreeInfo.skipParens(tree.expr);
657 if (expr.hasTag(APPLY)) {
658 JCMethodInvocation apply = (JCMethodInvocation)expr;
659 Symbol sym = TreeInfo.symbol(apply.meth);
660 is292targetTypeCast = sym != null &&
661 sym.kind == MTH &&
662 (sym.flags() & HYPOTHETICAL) != 0;
663 }
664 return is292targetTypeCast;
665 }
666
667 private static final boolean ignoreAnnotatedCasts = true;
668
669 /** Check that a type is within some bounds.
670 *
671 * Used in TypeApply to verify that, e.g., X in {@code V<X>} is a valid
672 * type argument.
673 * @param a The type that should be bounded by bs.
674 * @param bound The bound.
675 */
676 private boolean checkExtends(Type a, Type bound) {
677 if (a.isUnbound()) {
678 return true;
679 } else if (!a.hasTag(WILDCARD)) {
680 a = types.cvarUpperBound(a);
681 return types.isSubtype(a, bound);
682 } else if (a.isExtendsBound()) {
683 return types.isCastable(bound, types.wildUpperBound(a), types.noWarnings);
684 } else if (a.isSuperBound()) {
685 return !types.notSoftSubtype(types.wildLowerBound(a), bound);
686 }
687 return true;
688 }
689
690 /** Check that type is different from 'void'.
691 * @param pos Position to be used for error reporting.
692 * @param t The type to be checked.
693 */
694 Type checkNonVoid(DiagnosticPosition pos, Type t) {
695 if (t.hasTag(VOID)) {
696 log.error(pos, Errors.VoidNotAllowedHere);
697 return types.createErrorType(t);
698 } else {
699 return t;
700 }
701 }
702
703 Type checkClassOrArrayType(DiagnosticPosition pos, Type t) {
704 if (!t.hasTag(CLASS) && !t.hasTag(ARRAY) && !t.hasTag(ERROR)) {
705 return typeTagError(pos,
706 diags.fragment(Fragments.TypeReqClassArray),
707 asTypeParam(t));
708 } else {
709 return t;
710 }
711 }
712
713 /** Check that type is a class or interface type.
714 * @param pos Position to be used for error reporting.
715 * @param t The type to be checked.
716 */
717 Type checkClassType(DiagnosticPosition pos, Type t) {
718 if (!t.hasTag(CLASS) && !t.hasTag(ERROR)) {
719 return typeTagError(pos,
720 diags.fragment(Fragments.TypeReqClass),
721 asTypeParam(t));
722 } else {
723 return t;
724 }
725 }
726 //where
727 private Object asTypeParam(Type t) {
728 return (t.hasTag(TYPEVAR))
729 ? diags.fragment(Fragments.TypeParameter(t))
730 : t;
731 }
732
733 /** Check that type is a valid qualifier for a constructor reference expression
734 */
735 Type checkConstructorRefType(DiagnosticPosition pos, Type t) {
736 t = checkClassOrArrayType(pos, t);
737 if (t.hasTag(CLASS)) {
738 if ((t.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
739 log.error(pos, Errors.AbstractCantBeInstantiated(t.tsym));
740 t = types.createErrorType(t);
741 } else if ((t.tsym.flags() & ENUM) != 0) {
742 log.error(pos, Errors.EnumCantBeInstantiated);
743 t = types.createErrorType(t);
744 } else {
745 t = checkClassType(pos, t, true);
746 }
747 } else if (t.hasTag(ARRAY)) {
748 if (!types.isReifiable(((ArrayType)t).elemtype)) {
749 log.error(pos, Errors.GenericArrayCreation);
750 t = types.createErrorType(t);
751 }
752 }
753 return t;
754 }
755
756 /** Check that type is a class or interface type.
757 * @param pos Position to be used for error reporting.
758 * @param t The type to be checked.
759 * @param noBounds True if type bounds are illegal here.
760 */
761 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
762 t = checkClassType(pos, t);
763 if (noBounds && t.isParameterized()) {
764 List<Type> args = t.getTypeArguments();
765 while (args.nonEmpty()) {
766 if (args.head.hasTag(WILDCARD))
767 return typeTagError(pos,
768 diags.fragment(Fragments.TypeReqExact),
769 args.head);
770 args = args.tail;
771 }
772 }
773 return t;
774 }
775
776 /** Check that type is a reference type, i.e. a class, interface or array type
777 * or a type variable.
778 * @param pos Position to be used for error reporting.
779 * @param t The type to be checked.
780 */
781 Type checkRefType(DiagnosticPosition pos, Type t) {
782 if (t.isReference())
783 return t;
784 else
785 return typeTagError(pos,
786 diags.fragment(Fragments.TypeReqRef),
787 t);
788 }
789
790 /** Check that each type is a reference type, i.e. a class, interface or array type
791 * or a type variable.
792 * @param trees Original trees, used for error reporting.
793 * @param types The types to be checked.
794 */
795 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
796 List<JCExpression> tl = trees;
797 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
798 l.head = checkRefType(tl.head.pos(), l.head);
799 tl = tl.tail;
800 }
801 return types;
802 }
803
804 /** Check that type is a null or reference type.
805 * @param pos Position to be used for error reporting.
806 * @param t The type to be checked.
807 */
808 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
809 if (t.isReference() || t.hasTag(BOT))
810 return t;
811 else
812 return typeTagError(pos,
813 diags.fragment(Fragments.TypeReqRef),
814 t);
815 }
816
817 /** Check that flag set does not contain elements of two conflicting sets. s
818 * Return true if it doesn't.
819 * @param pos Position to be used for error reporting.
820 * @param flags The set of flags to be checked.
821 * @param set1 Conflicting flags set #1.
822 * @param set2 Conflicting flags set #2.
823 */
824 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
825 if ((flags & set1) != 0 && (flags & set2) != 0) {
826 log.error(pos,
827 Errors.IllegalCombinationOfModifiers(asFlagSet(TreeInfo.firstFlag(flags & set1)),
828 asFlagSet(TreeInfo.firstFlag(flags & set2))));
829 return false;
830 } else
831 return true;
832 }
833
834 /** Check that usage of diamond operator is correct (i.e. diamond should not
835 * be used with non-generic classes or in anonymous class creation expressions)
836 */
837 Type checkDiamond(JCNewClass tree, Type t) {
838 if (!TreeInfo.isDiamond(tree) ||
839 t.isErroneous()) {
840 return checkClassType(tree.clazz.pos(), t, true);
841 } else {
842 if (tree.def != null && !Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.allowedInSource(source)) {
843 log.error(DiagnosticFlag.SOURCE_LEVEL, tree.clazz.pos(),
844 Errors.CantApplyDiamond1(t, Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.fragment(source.name)));
845 }
846 if (t.tsym.type.getTypeArguments().isEmpty()) {
847 log.error(tree.clazz.pos(),
848 Errors.CantApplyDiamond1(t,
849 Fragments.DiamondNonGeneric(t)));
850 return types.createErrorType(t);
851 } else if (tree.typeargs != null &&
852 tree.typeargs.nonEmpty()) {
853 log.error(tree.clazz.pos(),
854 Errors.CantApplyDiamond1(t,
855 Fragments.DiamondAndExplicitParams(t)));
856 return types.createErrorType(t);
857 } else {
858 return t;
859 }
860 }
861 }
862
863 /** Check that the type inferred using the diamond operator does not contain
864 * non-denotable types such as captured types or intersection types.
865 * @param t the type inferred using the diamond operator
866 * @return the (possibly empty) list of non-denotable types.
867 */
868 List<Type> checkDiamondDenotable(ClassType t) {
869 ListBuffer<Type> buf = new ListBuffer<>();
870 for (Type arg : t.allparams()) {
871 if (!checkDenotable(arg)) {
872 buf.append(arg);
873 }
874 }
875 return buf.toList();
876 }
877
878 public boolean checkDenotable(Type t) {
879 return denotableChecker.visit(t, null);
880 }
881 // where
882
883 /** diamondTypeChecker: A type visitor that descends down the given type looking for non-denotable
884 * types. The visit methods return false as soon as a non-denotable type is encountered and true
885 * otherwise.
886 */
887 private static final Types.SimpleVisitor<Boolean, Void> denotableChecker = new Types.SimpleVisitor<Boolean, Void>() {
888 @Override
889 public Boolean visitType(Type t, Void s) {
890 return true;
891 }
892 @Override
893 public Boolean visitClassType(ClassType t, Void s) {
894 if (t.isUnion() || t.isIntersection()) {
895 return false;
896 }
897 for (Type targ : t.allparams()) {
898 if (!visit(targ, s)) {
899 return false;
900 }
901 }
902 return true;
903 }
904
905 @Override
906 public Boolean visitTypeVar(TypeVar t, Void s) {
907 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
908 (i.e cannot have been produced by inference (18.4))
909 */
910 return (t.tsym.flags() & SYNTHETIC) == 0;
911 }
912
913 @Override
914 public Boolean visitCapturedType(CapturedType t, Void s) {
915 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
916 (i.e cannot have been produced by capture conversion (5.1.10))
917 */
918 return false;
919 }
920
921 @Override
922 public Boolean visitArrayType(ArrayType t, Void s) {
923 return visit(t.elemtype, s);
924 }
925
926 @Override
927 public Boolean visitWildcardType(WildcardType t, Void s) {
928 return visit(t.type, s);
929 }
930 };
931
932 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
933 MethodSymbol m = tree.sym;
934 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
935 Type varargElemType = null;
936 if (m.isVarArgs()) {
937 varargElemType = types.elemtype(tree.params.last().type);
938 }
939 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
940 if (varargElemType != null) {
941 JCDiagnostic msg = Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ?
942 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargs(m)) :
943 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargsFinalOnly(m));
944 log.error(tree,
945 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
946 msg));
947 } else {
948 log.error(tree,
949 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
950 Fragments.VarargsTrustmeOnNonVarargsMeth(m)));
951 }
952 } else if (hasTrustMeAnno && varargElemType != null &&
953 types.isReifiable(varargElemType)) {
954 lint.logIfEnabled(tree, LintWarnings.VarargsRedundantTrustmeAnno(
955 syms.trustMeType.tsym,
956 diags.fragment(Fragments.VarargsTrustmeOnReifiableVarargs(varargElemType))));
957 }
958 else if (!hasTrustMeAnno && varargElemType != null &&
959 !types.isReifiable(varargElemType)) {
960 warnUnchecked(tree.params.head.pos(), LintWarnings.UncheckedVarargsNonReifiableType(varargElemType));
961 }
962 }
963 //where
964 private boolean isTrustMeAllowedOnMethod(Symbol s) {
965 return (s.flags() & VARARGS) != 0 &&
966 (s.isConstructor() ||
967 (s.flags() & (STATIC | FINAL |
968 (Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ? PRIVATE : 0) )) != 0);
969 }
970
971 Type checkLocalVarType(DiagnosticPosition pos, Type t, Name name) {
972 //check that resulting type is not the null type
973 if (t.hasTag(BOT)) {
974 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferNull));
975 return types.createErrorType(t);
976 } else if (t.hasTag(VOID)) {
977 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferVoid));
978 return types.createErrorType(t);
979 }
980
981 //upward project the initializer type
982 return types.upward(t, types.captures(t)).baseType();
983 }
984
985 Type checkMethod(final Type mtype,
986 final Symbol sym,
987 final Env<AttrContext> env,
988 final List<JCExpression> argtrees,
989 final List<Type> argtypes,
990 final boolean useVarargs,
991 InferenceContext inferenceContext) {
992 // System.out.println("call : " + env.tree);
993 // System.out.println("method : " + owntype);
994 // System.out.println("actuals: " + argtypes);
995 if (inferenceContext.free(mtype)) {
996 inferenceContext.addFreeTypeListener(List.of(mtype),
997 solvedContext -> checkMethod(solvedContext.asInstType(mtype), sym, env, argtrees, argtypes, useVarargs, solvedContext));
998 return mtype;
999 }
1000 Type owntype = mtype;
1001 List<Type> formals = owntype.getParameterTypes();
1002 List<Type> nonInferred = sym.type.getParameterTypes();
1003 if (nonInferred.length() != formals.length()) nonInferred = formals;
1004 Type last = useVarargs ? formals.last() : null;
1005 if (sym.name == names.init && sym.owner == syms.enumSym) {
1006 formals = formals.tail.tail;
1007 nonInferred = nonInferred.tail.tail;
1008 }
1009 if ((sym.flags() & ANONCONSTR_BASED) != 0) {
1010 formals = formals.tail;
1011 nonInferred = nonInferred.tail;
1012 }
1013 List<JCExpression> args = argtrees;
1014 if (args != null) {
1015 //this is null when type-checking a method reference
1016 while (formals.head != last) {
1017 JCTree arg = args.head;
1018 Warner warn = convertWarner(arg.pos(), arg.type, nonInferred.head);
1019 assertConvertible(arg, arg.type, formals.head, warn);
1020 args = args.tail;
1021 formals = formals.tail;
1022 nonInferred = nonInferred.tail;
1023 }
1024 if (useVarargs) {
1025 Type varArg = types.elemtype(last);
1026 while (args.tail != null) {
1027 JCTree arg = args.head;
1028 Warner warn = convertWarner(arg.pos(), arg.type, varArg);
1029 assertConvertible(arg, arg.type, varArg, warn);
1030 args = args.tail;
1031 }
1032 } else if ((sym.flags() & (VARARGS | SIGNATURE_POLYMORPHIC)) == VARARGS) {
1033 // non-varargs call to varargs method
1034 Type varParam = owntype.getParameterTypes().last();
1035 Type lastArg = argtypes.last();
1036 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
1037 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
1038 log.warning(argtrees.last().pos(),
1039 Warnings.InexactNonVarargsCall(types.elemtype(varParam),varParam));
1040 }
1041 }
1042 if (useVarargs) {
1043 Type argtype = owntype.getParameterTypes().last();
1044 if (!types.isReifiable(argtype) &&
1045 (sym.baseSymbol().attribute(syms.trustMeType.tsym) == null ||
1046 !isTrustMeAllowedOnMethod(sym))) {
1047 warnUnchecked(env.tree.pos(), LintWarnings.UncheckedGenericArrayCreation(argtype));
1048 }
1049 TreeInfo.setVarargsElement(env.tree, types.elemtype(argtype));
1050 }
1051 return owntype;
1052 }
1053 //where
1054 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
1055 if (types.isConvertible(actual, formal, warn))
1056 return;
1057
1058 if (formal.isCompound()
1059 && types.isSubtype(actual, types.supertype(formal))
1060 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
1061 return;
1062 }
1063
1064 /**
1065 * Check that type 't' is a valid instantiation of a generic class
1066 * (see JLS 4.5)
1067 *
1068 * @param t class type to be checked
1069 * @return true if 't' is well-formed
1070 */
1071 public boolean checkValidGenericType(Type t) {
1072 return firstIncompatibleTypeArg(t) == null;
1073 }
1074 //WHERE
1075 private Type firstIncompatibleTypeArg(Type type) {
1076 List<Type> formals = type.tsym.type.allparams();
1077 List<Type> actuals = type.allparams();
1078 List<Type> args = type.getTypeArguments();
1079 List<Type> forms = type.tsym.type.getTypeArguments();
1080 ListBuffer<Type> bounds_buf = new ListBuffer<>();
1081
1082 // For matching pairs of actual argument types `a' and
1083 // formal type parameters with declared bound `b' ...
1084 while (args.nonEmpty() && forms.nonEmpty()) {
1085 // exact type arguments needs to know their
1086 // bounds (for upper and lower bound
1087 // calculations). So we create new bounds where
1088 // type-parameters are replaced with actuals argument types.
1089 bounds_buf.append(types.subst(forms.head.getUpperBound(), formals, actuals));
1090 args = args.tail;
1091 forms = forms.tail;
1092 }
1093
1094 args = type.getTypeArguments();
1095 List<Type> tvars_cap = types.substBounds(formals,
1096 formals,
1097 types.capture(type).allparams());
1098 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
1099 // Let the actual arguments know their bound
1100 args.head.withTypeVar((TypeVar)tvars_cap.head);
1101 args = args.tail;
1102 tvars_cap = tvars_cap.tail;
1103 }
1104
1105 args = type.getTypeArguments();
1106 List<Type> bounds = bounds_buf.toList();
1107
1108 while (args.nonEmpty() && bounds.nonEmpty()) {
1109 Type actual = args.head;
1110 if (!isTypeArgErroneous(actual) &&
1111 !bounds.head.isErroneous() &&
1112 !checkExtends(actual, bounds.head)) {
1113 return args.head;
1114 }
1115 args = args.tail;
1116 bounds = bounds.tail;
1117 }
1118
1119 args = type.getTypeArguments();
1120 bounds = bounds_buf.toList();
1121
1122 for (Type arg : types.capture(type).getTypeArguments()) {
1123 if (arg.hasTag(TYPEVAR) &&
1124 arg.getUpperBound().isErroneous() &&
1125 !bounds.head.isErroneous() &&
1126 !isTypeArgErroneous(args.head)) {
1127 return args.head;
1128 }
1129 bounds = bounds.tail;
1130 args = args.tail;
1131 }
1132
1133 return null;
1134 }
1135 //where
1136 boolean isTypeArgErroneous(Type t) {
1137 return isTypeArgErroneous.visit(t);
1138 }
1139
1140 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() {
1141 public Boolean visitType(Type t, Void s) {
1142 return t.isErroneous();
1143 }
1144 @Override
1145 public Boolean visitTypeVar(TypeVar t, Void s) {
1146 return visit(t.getUpperBound());
1147 }
1148 @Override
1149 public Boolean visitCapturedType(CapturedType t, Void s) {
1150 return visit(t.getUpperBound()) ||
1151 visit(t.getLowerBound());
1152 }
1153 @Override
1154 public Boolean visitWildcardType(WildcardType t, Void s) {
1155 return visit(t.type);
1156 }
1157 };
1158
1159 /** Check that given modifiers are legal for given symbol and
1160 * return modifiers together with any implicit modifiers for that symbol.
1161 * Warning: we can't use flags() here since this method
1162 * is called during class enter, when flags() would cause a premature
1163 * completion.
1164 * @param flags The set of modifiers given in a definition.
1165 * @param sym The defined symbol.
1166 * @param tree The declaration
1167 */
1168 long checkFlags(long flags, Symbol sym, JCTree tree) {
1169 final DiagnosticPosition pos = tree.pos();
1170 long mask;
1171 long implicit = 0;
1172
1173 switch (sym.kind) {
1174 case VAR:
1175 if (TreeInfo.isReceiverParam(tree))
1176 mask = ReceiverParamFlags;
1177 else if (sym.owner.kind != TYP)
1178 mask = LocalVarFlags;
1179 else if ((sym.owner.flags_field & INTERFACE) != 0)
1180 mask = implicit = InterfaceVarFlags;
1181 else
1182 mask = VarFlags;
1183 break;
1184 case MTH:
1185 if (sym.name == names.init) {
1186 if ((sym.owner.flags_field & ENUM) != 0) {
1187 // enum constructors cannot be declared public or
1188 // protected and must be implicitly or explicitly
1189 // private
1190 implicit = PRIVATE;
1191 mask = PRIVATE;
1192 } else
1193 mask = ConstructorFlags;
1194 } else if ((sym.owner.flags_field & INTERFACE) != 0) {
1195 if ((sym.owner.flags_field & ANNOTATION) != 0) {
1196 mask = AnnotationTypeElementMask;
1197 implicit = PUBLIC | ABSTRACT;
1198 } else if ((flags & (DEFAULT | STATIC | PRIVATE)) != 0) {
1199 mask = InterfaceMethodMask;
1200 implicit = (flags & PRIVATE) != 0 ? 0 : PUBLIC;
1201 if ((flags & DEFAULT) != 0) {
1202 implicit |= ABSTRACT;
1203 }
1204 } else {
1205 mask = implicit = InterfaceMethodFlags;
1206 }
1207 } else if ((sym.owner.flags_field & RECORD) != 0) {
1208 mask = RecordMethodFlags;
1209 } else {
1210 mask = MethodFlags;
1211 }
1212 if ((flags & STRICTFP) != 0) {
1213 warnOnExplicitStrictfp(tree);
1214 }
1215 // Imply STRICTFP if owner has STRICTFP set.
1216 if (((flags|implicit) & Flags.ABSTRACT) == 0 ||
1217 ((flags) & Flags.DEFAULT) != 0)
1218 implicit |= sym.owner.flags_field & STRICTFP;
1219 break;
1220 case TYP:
1221 if (sym.owner.kind.matches(KindSelector.VAL_MTH) ||
1222 (sym.isDirectlyOrIndirectlyLocal() && (flags & ANNOTATION) != 0)) {
1223 boolean implicitlyStatic = !sym.isAnonymous() &&
1224 ((flags & RECORD) != 0 || (flags & ENUM) != 0 || (flags & INTERFACE) != 0);
1225 boolean staticOrImplicitlyStatic = (flags & STATIC) != 0 || implicitlyStatic;
1226 // local statics are allowed only if records are allowed too
1227 mask = staticOrImplicitlyStatic && allowRecords && (flags & ANNOTATION) == 0 ? StaticLocalFlags : LocalClassFlags;
1228 implicit = implicitlyStatic ? STATIC : implicit;
1229 } else if (sym.owner.kind == TYP) {
1230 // statics in inner classes are allowed only if records are allowed too
1231 mask = ((flags & STATIC) != 0) && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedMemberStaticClassFlags : ExtendedMemberClassFlags;
1232 if (sym.owner.owner.kind == PCK ||
1233 (sym.owner.flags_field & STATIC) != 0) {
1234 mask |= STATIC;
1235 } else if (!allowRecords && ((flags & ENUM) != 0 || (flags & RECORD) != 0)) {
1236 log.error(pos, Errors.StaticDeclarationNotAllowedInInnerClasses);
1237 }
1238 // Nested interfaces and enums are always STATIC (Spec ???)
1239 if ((flags & (INTERFACE | ENUM | RECORD)) != 0 ) implicit = STATIC;
1240 } else {
1241 mask = ExtendedClassFlags;
1242 }
1243 // Interfaces are always ABSTRACT
1244 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
1245
1246 if ((flags & ENUM) != 0) {
1247 // enums can't be declared abstract, final, sealed or non-sealed
1248 mask &= ~(ABSTRACT | FINAL | SEALED | NON_SEALED);
1249 implicit |= implicitEnumFinalFlag(tree);
1250 }
1251 if ((flags & RECORD) != 0) {
1252 // records can't be declared abstract
1253 mask &= ~ABSTRACT;
1254 implicit |= FINAL;
1255 }
1256 if ((flags & STRICTFP) != 0) {
1257 warnOnExplicitStrictfp(tree);
1258 }
1259 // Imply STRICTFP if owner has STRICTFP set.
1260 implicit |= sym.owner.flags_field & STRICTFP;
1261 break;
1262 default:
1263 throw new AssertionError();
1264 }
1265 long illegal = flags & ExtendedStandardFlags & ~mask;
1266 if (illegal != 0) {
1267 if ((illegal & INTERFACE) != 0) {
1268 log.error(pos, ((flags & ANNOTATION) != 0) ? Errors.AnnotationDeclNotAllowedHere : Errors.IntfNotAllowedHere);
1269 mask |= INTERFACE;
1270 }
1271 else {
1272 log.error(pos,
1273 Errors.ModNotAllowedHere(asFlagSet(illegal)));
1274 }
1275 }
1276 else if ((sym.kind == TYP ||
1277 // ISSUE: Disallowing abstract&private is no longer appropriate
1278 // in the presence of inner classes. Should it be deleted here?
1279 checkDisjoint(pos, flags,
1280 ABSTRACT,
1281 PRIVATE | STATIC | DEFAULT))
1282 &&
1283 checkDisjoint(pos, flags,
1284 STATIC | PRIVATE,
1285 DEFAULT)
1286 &&
1287 checkDisjoint(pos, flags,
1288 ABSTRACT | INTERFACE,
1289 FINAL | NATIVE | SYNCHRONIZED)
1290 &&
1291 checkDisjoint(pos, flags,
1292 PUBLIC,
1293 PRIVATE | PROTECTED)
1294 &&
1295 checkDisjoint(pos, flags,
1296 PRIVATE,
1297 PUBLIC | PROTECTED)
1298 &&
1299 checkDisjoint(pos, flags,
1300 FINAL,
1301 VOLATILE)
1302 &&
1303 (sym.kind == TYP ||
1304 checkDisjoint(pos, flags,
1305 ABSTRACT | NATIVE,
1306 STRICTFP))
1307 && checkDisjoint(pos, flags,
1308 FINAL,
1309 SEALED | NON_SEALED)
1310 && checkDisjoint(pos, flags,
1311 SEALED,
1312 FINAL | NON_SEALED)
1313 && checkDisjoint(pos, flags,
1314 SEALED,
1315 ANNOTATION)) {
1316 // skip
1317 }
1318 return flags & (mask | ~ExtendedStandardFlags) | implicit;
1319 }
1320
1321 private void warnOnExplicitStrictfp(JCTree tree) {
1322 deferredLintHandler.push(tree);
1323 try {
1324 deferredLintHandler.report(_ -> lint.logIfEnabled(tree.pos(), LintWarnings.Strictfp));
1325 } finally {
1326 deferredLintHandler.pop();
1327 }
1328 }
1329
1330
1331 /** Determine if this enum should be implicitly final.
1332 *
1333 * If the enum has no specialized enum constants, it is final.
1334 *
1335 * If the enum does have specialized enum constants, it is
1336 * <i>not</i> final.
1337 */
1338 private long implicitEnumFinalFlag(JCTree tree) {
1339 if (!tree.hasTag(CLASSDEF)) return 0;
1340 class SpecialTreeVisitor extends JCTree.Visitor {
1341 boolean specialized;
1342 SpecialTreeVisitor() {
1343 this.specialized = false;
1344 }
1345
1346 @Override
1347 public void visitTree(JCTree tree) { /* no-op */ }
1348
1349 @Override
1350 public void visitVarDef(JCVariableDecl tree) {
1351 if ((tree.mods.flags & ENUM) != 0) {
1352 if (tree.init instanceof JCNewClass newClass && newClass.def != null) {
1353 specialized = true;
1354 }
1355 }
1356 }
1357 }
1358
1359 SpecialTreeVisitor sts = new SpecialTreeVisitor();
1360 JCClassDecl cdef = (JCClassDecl) tree;
1361 for (JCTree defs: cdef.defs) {
1362 defs.accept(sts);
1363 if (sts.specialized) return allowSealed ? SEALED : 0;
1364 }
1365 return FINAL;
1366 }
1367
1368 /* *************************************************************************
1369 * Type Validation
1370 **************************************************************************/
1371
1372 /** Validate a type expression. That is,
1373 * check that all type arguments of a parametric type are within
1374 * their bounds. This must be done in a second phase after type attribution
1375 * since a class might have a subclass as type parameter bound. E.g:
1376 *
1377 * <pre>{@code
1378 * class B<A extends C> { ... }
1379 * class C extends B<C> { ... }
1380 * }</pre>
1381 *
1382 * and we can't make sure that the bound is already attributed because
1383 * of possible cycles.
1384 *
1385 * Visitor method: Validate a type expression, if it is not null, catching
1386 * and reporting any completion failures.
1387 */
1388 void validate(JCTree tree, Env<AttrContext> env) {
1389 validate(tree, env, true);
1390 }
1391 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1392 new Validator(env).validateTree(tree, checkRaw, true);
1393 }
1394
1395 /** Visitor method: Validate a list of type expressions.
1396 */
1397 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1398 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1399 validate(l.head, env);
1400 }
1401
1402 /** A visitor class for type validation.
1403 */
1404 class Validator extends JCTree.Visitor {
1405
1406 boolean checkRaw;
1407 boolean isOuter;
1408 Env<AttrContext> env;
1409
1410 Validator(Env<AttrContext> env) {
1411 this.env = env;
1412 }
1413
1414 @Override
1415 public void visitTypeArray(JCArrayTypeTree tree) {
1416 validateTree(tree.elemtype, checkRaw, isOuter);
1417 }
1418
1419 @Override
1420 public void visitTypeApply(JCTypeApply tree) {
1421 if (tree.type.hasTag(CLASS)) {
1422 List<JCExpression> args = tree.arguments;
1423 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1424
1425 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1426 if (incompatibleArg != null) {
1427 for (JCTree arg : tree.arguments) {
1428 if (arg.type == incompatibleArg) {
1429 log.error(arg, Errors.NotWithinBounds(incompatibleArg, forms.head));
1430 }
1431 forms = forms.tail;
1432 }
1433 }
1434
1435 forms = tree.type.tsym.type.getTypeArguments();
1436
1437 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1438
1439 // For matching pairs of actual argument types `a' and
1440 // formal type parameters with declared bound `b' ...
1441 while (args.nonEmpty() && forms.nonEmpty()) {
1442 validateTree(args.head,
1443 !(isOuter && is_java_lang_Class),
1444 false);
1445 args = args.tail;
1446 forms = forms.tail;
1447 }
1448
1449 // Check that this type is either fully parameterized, or
1450 // not parameterized at all.
1451 if (tree.type.getEnclosingType().isRaw())
1452 log.error(tree.pos(), Errors.ImproperlyFormedTypeInnerRawParam);
1453 if (tree.clazz.hasTag(SELECT))
1454 visitSelectInternal((JCFieldAccess)tree.clazz);
1455 }
1456 }
1457
1458 @Override
1459 public void visitTypeParameter(JCTypeParameter tree) {
1460 validateTrees(tree.bounds, true, isOuter);
1461 checkClassBounds(tree.pos(), tree.type);
1462 }
1463
1464 @Override
1465 public void visitWildcard(JCWildcard tree) {
1466 if (tree.inner != null)
1467 validateTree(tree.inner, true, isOuter);
1468 }
1469
1470 @Override
1471 public void visitSelect(JCFieldAccess tree) {
1472 if (tree.type.hasTag(CLASS)) {
1473 visitSelectInternal(tree);
1474
1475 // Check that this type is either fully parameterized, or
1476 // not parameterized at all.
1477 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1478 log.error(tree.pos(), Errors.ImproperlyFormedTypeParamMissing);
1479 }
1480 }
1481
1482 public void visitSelectInternal(JCFieldAccess tree) {
1483 if (tree.type.tsym.isStatic() &&
1484 tree.selected.type.isParameterized()) {
1485 // The enclosing type is not a class, so we are
1486 // looking at a static member type. However, the
1487 // qualifying expression is parameterized.
1488 log.error(tree.pos(), Errors.CantSelectStaticClassFromParamType);
1489 } else {
1490 // otherwise validate the rest of the expression
1491 tree.selected.accept(this);
1492 }
1493 }
1494
1495 @Override
1496 public void visitAnnotatedType(JCAnnotatedType tree) {
1497 tree.underlyingType.accept(this);
1498 }
1499
1500 @Override
1501 public void visitTypeIdent(JCPrimitiveTypeTree that) {
1502 if (that.type.hasTag(TypeTag.VOID)) {
1503 log.error(that.pos(), Errors.VoidNotAllowedHere);
1504 }
1505 super.visitTypeIdent(that);
1506 }
1507
1508 /** Default visitor method: do nothing.
1509 */
1510 @Override
1511 public void visitTree(JCTree tree) {
1512 }
1513
1514 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1515 if (tree != null) {
1516 boolean prevCheckRaw = this.checkRaw;
1517 this.checkRaw = checkRaw;
1518 this.isOuter = isOuter;
1519
1520 try {
1521 tree.accept(this);
1522 if (checkRaw)
1523 checkRaw(tree, env);
1524 } catch (CompletionFailure ex) {
1525 completionError(tree.pos(), ex);
1526 } finally {
1527 this.checkRaw = prevCheckRaw;
1528 }
1529 }
1530 }
1531
1532 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1533 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1534 validateTree(l.head, checkRaw, isOuter);
1535 }
1536 }
1537
1538 void checkRaw(JCTree tree, Env<AttrContext> env) {
1539 if (tree.type.hasTag(CLASS) &&
1540 !TreeInfo.isDiamond(tree) &&
1541 !withinAnonConstr(env) &&
1542 tree.type.isRaw()) {
1543 lint.logIfEnabled(tree.pos(), LintWarnings.RawClassUse(tree.type, tree.type.tsym.type));
1544 }
1545 }
1546 //where
1547 private boolean withinAnonConstr(Env<AttrContext> env) {
1548 return env.enclClass.name.isEmpty() &&
1549 env.enclMethod != null && env.enclMethod.name == names.init;
1550 }
1551
1552 /* *************************************************************************
1553 * Exception checking
1554 **************************************************************************/
1555
1556 /* The following methods treat classes as sets that contain
1557 * the class itself and all their subclasses
1558 */
1559
1560 /** Is given type a subtype of some of the types in given list?
1561 */
1562 boolean subset(Type t, List<Type> ts) {
1563 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1564 if (types.isSubtype(t, l.head)) return true;
1565 return false;
1566 }
1567
1568 /** Is given type a subtype or supertype of
1569 * some of the types in given list?
1570 */
1571 boolean intersects(Type t, List<Type> ts) {
1572 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1573 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1574 return false;
1575 }
1576
1577 /** Add type set to given type list, unless it is a subclass of some class
1578 * in the list.
1579 */
1580 List<Type> incl(Type t, List<Type> ts) {
1581 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1582 }
1583
1584 /** Remove type set from type set list.
1585 */
1586 List<Type> excl(Type t, List<Type> ts) {
1587 if (ts.isEmpty()) {
1588 return ts;
1589 } else {
1590 List<Type> ts1 = excl(t, ts.tail);
1591 if (types.isSubtype(ts.head, t)) return ts1;
1592 else if (ts1 == ts.tail) return ts;
1593 else return ts1.prepend(ts.head);
1594 }
1595 }
1596
1597 /** Form the union of two type set lists.
1598 */
1599 List<Type> union(List<Type> ts1, List<Type> ts2) {
1600 List<Type> ts = ts1;
1601 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1602 ts = incl(l.head, ts);
1603 return ts;
1604 }
1605
1606 /** Form the difference of two type lists.
1607 */
1608 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1609 List<Type> ts = ts1;
1610 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1611 ts = excl(l.head, ts);
1612 return ts;
1613 }
1614
1615 /** Form the intersection of two type lists.
1616 */
1617 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1618 List<Type> ts = List.nil();
1619 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1620 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1621 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1622 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1623 return ts;
1624 }
1625
1626 /** Is exc an exception symbol that need not be declared?
1627 */
1628 boolean isUnchecked(ClassSymbol exc) {
1629 return
1630 exc.kind == ERR ||
1631 exc.isSubClass(syms.errorType.tsym, types) ||
1632 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1633 }
1634
1635 /** Is exc an exception type that need not be declared?
1636 */
1637 boolean isUnchecked(Type exc) {
1638 return
1639 (exc.hasTag(TYPEVAR)) ? isUnchecked(types.supertype(exc)) :
1640 (exc.hasTag(CLASS)) ? isUnchecked((ClassSymbol)exc.tsym) :
1641 exc.hasTag(BOT);
1642 }
1643
1644 boolean isChecked(Type exc) {
1645 return !isUnchecked(exc);
1646 }
1647
1648 /** Same, but handling completion failures.
1649 */
1650 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1651 try {
1652 return isUnchecked(exc);
1653 } catch (CompletionFailure ex) {
1654 completionError(pos, ex);
1655 return true;
1656 }
1657 }
1658
1659 /** Is exc handled by given exception list?
1660 */
1661 boolean isHandled(Type exc, List<Type> handled) {
1662 return isUnchecked(exc) || subset(exc, handled);
1663 }
1664
1665 /** Return all exceptions in thrown list that are not in handled list.
1666 * @param thrown The list of thrown exceptions.
1667 * @param handled The list of handled exceptions.
1668 */
1669 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1670 List<Type> unhandled = List.nil();
1671 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1672 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1673 return unhandled;
1674 }
1675
1676 /* *************************************************************************
1677 * Overriding/Implementation checking
1678 **************************************************************************/
1679
1680 /** The level of access protection given by a flag set,
1681 * where PRIVATE is highest and PUBLIC is lowest.
1682 */
1683 static int protection(long flags) {
1684 switch ((short)(flags & AccessFlags)) {
1685 case PRIVATE: return 3;
1686 case PROTECTED: return 1;
1687 default:
1688 case PUBLIC: return 0;
1689 case 0: return 2;
1690 }
1691 }
1692
1693 /** A customized "cannot override" error message.
1694 * @param m The overriding method.
1695 * @param other The overridden method.
1696 * @return An internationalized string.
1697 */
1698 Fragment cannotOverride(MethodSymbol m, MethodSymbol other) {
1699 Symbol mloc = m.location();
1700 Symbol oloc = other.location();
1701
1702 if ((other.owner.flags() & INTERFACE) == 0)
1703 return Fragments.CantOverride(m, mloc, other, oloc);
1704 else if ((m.owner.flags() & INTERFACE) == 0)
1705 return Fragments.CantImplement(m, mloc, other, oloc);
1706 else
1707 return Fragments.ClashesWith(m, mloc, other, oloc);
1708 }
1709
1710 /** A customized "override" warning message.
1711 * @param m The overriding method.
1712 * @param other The overridden method.
1713 * @return An internationalized string.
1714 */
1715 Fragment uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1716 Symbol mloc = m.location();
1717 Symbol oloc = other.location();
1718
1719 if ((other.owner.flags() & INTERFACE) == 0)
1720 return Fragments.UncheckedOverride(m, mloc, other, oloc);
1721 else if ((m.owner.flags() & INTERFACE) == 0)
1722 return Fragments.UncheckedImplement(m, mloc, other, oloc);
1723 else
1724 return Fragments.UncheckedClashWith(m, mloc, other, oloc);
1725 }
1726
1727 /** A customized "override" warning message.
1728 * @param m The overriding method.
1729 * @param other The overridden method.
1730 * @return An internationalized string.
1731 */
1732 Fragment varargsOverrides(MethodSymbol m, MethodSymbol other) {
1733 Symbol mloc = m.location();
1734 Symbol oloc = other.location();
1735
1736 if ((other.owner.flags() & INTERFACE) == 0)
1737 return Fragments.VarargsOverride(m, mloc, other, oloc);
1738 else if ((m.owner.flags() & INTERFACE) == 0)
1739 return Fragments.VarargsImplement(m, mloc, other, oloc);
1740 else
1741 return Fragments.VarargsClashWith(m, mloc, other, oloc);
1742 }
1743
1744 /** Check that this method conforms with overridden method 'other'.
1745 * where `origin' is the class where checking started.
1746 * Complications:
1747 * (1) Do not check overriding of synthetic methods
1748 * (reason: they might be final).
1749 * todo: check whether this is still necessary.
1750 * (2) Admit the case where an interface proxy throws fewer exceptions
1751 * than the method it implements. Augment the proxy methods with the
1752 * undeclared exceptions in this case.
1753 * (3) When generics are enabled, admit the case where an interface proxy
1754 * has a result type
1755 * extended by the result type of the method it implements.
1756 * Change the proxies result type to the smaller type in this case.
1757 *
1758 * @param tree The tree from which positions
1759 * are extracted for errors.
1760 * @param m The overriding method.
1761 * @param other The overridden method.
1762 * @param origin The class of which the overriding method
1763 * is a member.
1764 */
1765 void checkOverride(JCTree tree,
1766 MethodSymbol m,
1767 MethodSymbol other,
1768 ClassSymbol origin) {
1769 // Don't check overriding of synthetic methods or by bridge methods.
1770 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1771 return;
1772 }
1773
1774 // Error if static method overrides instance method (JLS 8.4.8.2).
1775 if ((m.flags() & STATIC) != 0 &&
1776 (other.flags() & STATIC) == 0) {
1777 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1778 Errors.OverrideStatic(cannotOverride(m, other)));
1779 m.flags_field |= BAD_OVERRIDE;
1780 return;
1781 }
1782
1783 // Error if instance method overrides static or final
1784 // method (JLS 8.4.8.1).
1785 if ((other.flags() & FINAL) != 0 ||
1786 (m.flags() & STATIC) == 0 &&
1787 (other.flags() & STATIC) != 0) {
1788 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1789 Errors.OverrideMeth(cannotOverride(m, other),
1790 asFlagSet(other.flags() & (FINAL | STATIC))));
1791 m.flags_field |= BAD_OVERRIDE;
1792 return;
1793 }
1794
1795 if ((m.owner.flags() & ANNOTATION) != 0) {
1796 // handled in validateAnnotationMethod
1797 return;
1798 }
1799
1800 // Error if overriding method has weaker access (JLS 8.4.8.3).
1801 if (protection(m.flags()) > protection(other.flags())) {
1802 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1803 (other.flags() & AccessFlags) == 0 ?
1804 Errors.OverrideWeakerAccess(cannotOverride(m, other),
1805 "package") :
1806 Errors.OverrideWeakerAccess(cannotOverride(m, other),
1807 asFlagSet(other.flags() & AccessFlags)));
1808 m.flags_field |= BAD_OVERRIDE;
1809 return;
1810 }
1811
1812 if (shouldCheckPreview(m, other, origin)) {
1813 checkPreview(TreeInfo.diagnosticPositionFor(m, tree),
1814 m, origin.type, other);
1815 }
1816
1817 Type mt = types.memberType(origin.type, m);
1818 Type ot = types.memberType(origin.type, other);
1819 // Error if overriding result type is different
1820 // (or, in the case of generics mode, not a subtype) of
1821 // overridden result type. We have to rename any type parameters
1822 // before comparing types.
1823 List<Type> mtvars = mt.getTypeArguments();
1824 List<Type> otvars = ot.getTypeArguments();
1825 Type mtres = mt.getReturnType();
1826 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1827
1828 overrideWarner.clear();
1829 boolean resultTypesOK =
1830 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1831 if (!resultTypesOK) {
1832 if ((m.flags() & STATIC) != 0 && (other.flags() & STATIC) != 0) {
1833 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1834 Errors.OverrideIncompatibleRet(Fragments.CantHide(m, m.location(), other,
1835 other.location()), mtres, otres));
1836 m.flags_field |= BAD_OVERRIDE;
1837 } else {
1838 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1839 Errors.OverrideIncompatibleRet(cannotOverride(m, other), mtres, otres));
1840 m.flags_field |= BAD_OVERRIDE;
1841 }
1842 return;
1843 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1844 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1845 LintWarnings.OverrideUncheckedRet(uncheckedOverrides(m, other), mtres, otres));
1846 }
1847
1848 // Error if overriding method throws an exception not reported
1849 // by overridden method.
1850 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1851 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1852 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1853 if (unhandledErased.nonEmpty()) {
1854 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1855 Errors.OverrideMethDoesntThrow(cannotOverride(m, other), unhandledUnerased.head));
1856 m.flags_field |= BAD_OVERRIDE;
1857 return;
1858 }
1859 else if (unhandledUnerased.nonEmpty()) {
1860 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1861 LintWarnings.OverrideUncheckedThrown(cannotOverride(m, other), unhandledUnerased.head));
1862 return;
1863 }
1864
1865 // Optional warning if varargs don't agree
1866 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)) {
1867 lint.logIfEnabled(TreeInfo.diagnosticPositionFor(m, tree),
1868 ((m.flags() & Flags.VARARGS) != 0)
1869 ? LintWarnings.OverrideVarargsMissing(varargsOverrides(m, other))
1870 : LintWarnings.OverrideVarargsExtra(varargsOverrides(m, other)));
1871 }
1872
1873 // Warn if instance method overrides bridge method (compiler spec ??)
1874 if ((other.flags() & BRIDGE) != 0) {
1875 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1876 Warnings.OverrideBridge(uncheckedOverrides(m, other)));
1877 }
1878
1879 // Warn if a deprecated method overridden by a non-deprecated one.
1880 if (!isDeprecatedOverrideIgnorable(other, origin)) {
1881 Lint prevLint = setLint(lint.augment(m));
1882 try {
1883 checkDeprecated(() -> TreeInfo.diagnosticPositionFor(m, tree), m, other);
1884 } finally {
1885 setLint(prevLint);
1886 }
1887 }
1888 }
1889 // where
1890 private boolean shouldCheckPreview(MethodSymbol m, MethodSymbol other, ClassSymbol origin) {
1891 if (m.owner != origin ||
1892 //performance - only do the expensive checks when the overridden method is a Preview API:
1893 ((other.flags() & PREVIEW_API) == 0 &&
1894 (other.owner.flags() & PREVIEW_API) == 0)) {
1895 return false;
1896 }
1897
1898 for (Symbol s : types.membersClosure(origin.type, false).getSymbolsByName(m.name)) {
1899 if (m != s && m.overrides(s, origin, types, false)) {
1900 //only produce preview warnings or errors if "m" immediatelly overrides "other"
1901 //without intermediate overriding methods:
1902 return s == other;
1903 }
1904 }
1905
1906 return false;
1907 }
1908 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1909 // If the method, m, is defined in an interface, then ignore the issue if the method
1910 // is only inherited via a supertype and also implemented in the supertype,
1911 // because in that case, we will rediscover the issue when examining the method
1912 // in the supertype.
1913 // If the method, m, is not defined in an interface, then the only time we need to
1914 // address the issue is when the method is the supertype implementation: any other
1915 // case, we will have dealt with when examining the supertype classes
1916 ClassSymbol mc = m.enclClass();
1917 Type st = types.supertype(origin.type);
1918 if (!st.hasTag(CLASS))
1919 return true;
1920 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1921
1922 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1923 List<Type> intfs = types.interfaces(origin.type);
1924 return (intfs.contains(mc.type) ? false : (stimpl != null));
1925 }
1926 else
1927 return (stimpl != m);
1928 }
1929
1930
1931 // used to check if there were any unchecked conversions
1932 Warner overrideWarner = new Warner();
1933
1934 /** Check that a class does not inherit two concrete methods
1935 * with the same signature.
1936 * @param pos Position to be used for error reporting.
1937 * @param site The class type to be checked.
1938 */
1939 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1940 Type sup = types.supertype(site);
1941 if (!sup.hasTag(CLASS)) return;
1942
1943 for (Type t1 = sup;
1944 t1.hasTag(CLASS) && t1.tsym.type.isParameterized();
1945 t1 = types.supertype(t1)) {
1946 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) {
1947 if (s1.kind != MTH ||
1948 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1949 !s1.isInheritedIn(site.tsym, types) ||
1950 ((MethodSymbol)s1).implementation(site.tsym,
1951 types,
1952 true) != s1)
1953 continue;
1954 Type st1 = types.memberType(t1, s1);
1955 int s1ArgsLength = st1.getParameterTypes().length();
1956 if (st1 == s1.type) continue;
1957
1958 for (Type t2 = sup;
1959 t2.hasTag(CLASS);
1960 t2 = types.supertype(t2)) {
1961 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) {
1962 if (s2 == s1 ||
1963 s2.kind != MTH ||
1964 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1965 s2.type.getParameterTypes().length() != s1ArgsLength ||
1966 !s2.isInheritedIn(site.tsym, types) ||
1967 ((MethodSymbol)s2).implementation(site.tsym,
1968 types,
1969 true) != s2)
1970 continue;
1971 Type st2 = types.memberType(t2, s2);
1972 if (types.overrideEquivalent(st1, st2))
1973 log.error(pos,
1974 Errors.ConcreteInheritanceConflict(s1, t1, s2, t2, sup));
1975 }
1976 }
1977 }
1978 }
1979 }
1980
1981 /** Check that classes (or interfaces) do not each define an abstract
1982 * method with same name and arguments but incompatible return types.
1983 * @param pos Position to be used for error reporting.
1984 * @param t1 The first argument type.
1985 * @param t2 The second argument type.
1986 */
1987 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1988 Type t1,
1989 Type t2,
1990 Type site) {
1991 if ((site.tsym.flags() & COMPOUND) != 0) {
1992 // special case for intersections: need to eliminate wildcards in supertypes
1993 t1 = types.capture(t1);
1994 t2 = types.capture(t2);
1995 }
1996 return firstIncompatibility(pos, t1, t2, site) == null;
1997 }
1998
1999 /** Return the first method which is defined with same args
2000 * but different return types in two given interfaces, or null if none
2001 * exists.
2002 * @param t1 The first type.
2003 * @param t2 The second type.
2004 * @param site The most derived type.
2005 * @return symbol from t2 that conflicts with one in t1.
2006 */
2007 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
2008 Map<TypeSymbol,Type> interfaces1 = new HashMap<>();
2009 closure(t1, interfaces1);
2010 Map<TypeSymbol,Type> interfaces2;
2011 if (t1 == t2)
2012 interfaces2 = interfaces1;
2013 else
2014 closure(t2, interfaces1, interfaces2 = new HashMap<>());
2015
2016 for (Type t3 : interfaces1.values()) {
2017 for (Type t4 : interfaces2.values()) {
2018 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
2019 if (s != null) return s;
2020 }
2021 }
2022 return null;
2023 }
2024
2025 /** Compute all the supertypes of t, indexed by type symbol. */
2026 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
2027 if (!t.hasTag(CLASS)) return;
2028 if (typeMap.put(t.tsym, t) == null) {
2029 closure(types.supertype(t), typeMap);
2030 for (Type i : types.interfaces(t))
2031 closure(i, typeMap);
2032 }
2033 }
2034
2035 /** Compute all the supertypes of t, indexed by type symbol (except those in typesSkip). */
2036 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
2037 if (!t.hasTag(CLASS)) return;
2038 if (typesSkip.get(t.tsym) != null) return;
2039 if (typeMap.put(t.tsym, t) == null) {
2040 closure(types.supertype(t), typesSkip, typeMap);
2041 for (Type i : types.interfaces(t))
2042 closure(i, typesSkip, typeMap);
2043 }
2044 }
2045
2046 /** Return the first method in t2 that conflicts with a method from t1. */
2047 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
2048 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) {
2049 Type st1 = null;
2050 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types) ||
2051 (s1.flags() & SYNTHETIC) != 0) continue;
2052 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
2053 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
2054 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) {
2055 if (s1 == s2) continue;
2056 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types) ||
2057 (s2.flags() & SYNTHETIC) != 0) continue;
2058 if (st1 == null) st1 = types.memberType(t1, s1);
2059 Type st2 = types.memberType(t2, s2);
2060 if (types.overrideEquivalent(st1, st2)) {
2061 List<Type> tvars1 = st1.getTypeArguments();
2062 List<Type> tvars2 = st2.getTypeArguments();
2063 Type rt1 = st1.getReturnType();
2064 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
2065 boolean compat =
2066 types.isSameType(rt1, rt2) ||
2067 !rt1.isPrimitiveOrVoid() &&
2068 !rt2.isPrimitiveOrVoid() &&
2069 (types.covariantReturnType(rt1, rt2, types.noWarnings) ||
2070 types.covariantReturnType(rt2, rt1, types.noWarnings)) ||
2071 checkCommonOverriderIn(s1,s2,site);
2072 if (!compat) {
2073 if (types.isSameType(t1, t2)) {
2074 log.error(pos, Errors.IncompatibleDiffRetSameType(t1,
2075 s2.name, types.memberType(t2, s2).getParameterTypes()));
2076 } else {
2077 log.error(pos, Errors.TypesIncompatible(t1, t2,
2078 Fragments.IncompatibleDiffRet(s2.name, types.memberType(t2, s2).getParameterTypes())));
2079 }
2080 return s2;
2081 }
2082 } else if (checkNameClash((ClassSymbol)site.tsym, s1, s2) &&
2083 !checkCommonOverriderIn(s1, s2, site)) {
2084 log.error(pos, Errors.NameClashSameErasureNoOverride(
2085 s1.name, types.memberType(site, s1).asMethodType().getParameterTypes(), s1.location(),
2086 s2.name, types.memberType(site, s2).asMethodType().getParameterTypes(), s2.location()));
2087 return s2;
2088 }
2089 }
2090 }
2091 return null;
2092 }
2093 //WHERE
2094 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
2095 Map<TypeSymbol,Type> supertypes = new HashMap<>();
2096 Type st1 = types.memberType(site, s1);
2097 Type st2 = types.memberType(site, s2);
2098 closure(site, supertypes);
2099 for (Type t : supertypes.values()) {
2100 for (Symbol s3 : t.tsym.members().getSymbolsByName(s1.name)) {
2101 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
2102 Type st3 = types.memberType(site,s3);
2103 if (types.overrideEquivalent(st3, st1) &&
2104 types.overrideEquivalent(st3, st2) &&
2105 types.returnTypeSubstitutable(st3, st1) &&
2106 types.returnTypeSubstitutable(st3, st2)) {
2107 return true;
2108 }
2109 }
2110 }
2111 return false;
2112 }
2113
2114 /** Check that a given method conforms with any method it overrides.
2115 * @param tree The tree from which positions are extracted
2116 * for errors.
2117 * @param m The overriding method.
2118 */
2119 void checkOverride(Env<AttrContext> env, JCMethodDecl tree, MethodSymbol m) {
2120 ClassSymbol origin = (ClassSymbol)m.owner;
2121 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name)) {
2122 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
2123 log.error(tree.pos(), Errors.EnumNoFinalize);
2124 return;
2125 }
2126 }
2127 if (allowRecords && origin.isRecord()) {
2128 // let's find out if this is a user defined accessor in which case the @Override annotation is acceptable
2129 Optional<? extends RecordComponent> recordComponent = origin.getRecordComponents().stream()
2130 .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
2131 if (recordComponent.isPresent()) {
2132 return;
2133 }
2134 }
2135
2136 for (Type t = origin.type; t.hasTag(CLASS);
2137 t = types.supertype(t)) {
2138 if (t != origin.type) {
2139 checkOverride(tree, t, origin, m);
2140 }
2141 for (Type t2 : types.interfaces(t)) {
2142 checkOverride(tree, t2, origin, m);
2143 }
2144 }
2145
2146 final boolean explicitOverride = m.attribute(syms.overrideType.tsym) != null;
2147 // Check if this method must override a super method due to being annotated with @Override
2148 // or by virtue of being a member of a diamond inferred anonymous class. Latter case is to
2149 // be treated "as if as they were annotated" with @Override.
2150 boolean mustOverride = explicitOverride ||
2151 (env.info.isAnonymousDiamond && !m.isConstructor() && !m.isPrivate());
2152 if (mustOverride && !isOverrider(m)) {
2153 DiagnosticPosition pos = tree.pos();
2154 for (JCAnnotation a : tree.getModifiers().annotations) {
2155 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2156 pos = a.pos();
2157 break;
2158 }
2159 }
2160 log.error(pos,
2161 explicitOverride ? (m.isStatic() ? Errors.StaticMethodsCannotBeAnnotatedWithOverride : Errors.MethodDoesNotOverrideSuperclass) :
2162 Errors.AnonymousDiamondMethodDoesNotOverrideSuperclass(Fragments.DiamondAnonymousMethodsImplicitlyOverride));
2163 }
2164 }
2165
2166 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
2167 TypeSymbol c = site.tsym;
2168 for (Symbol sym : c.members().getSymbolsByName(m.name)) {
2169 if (m.overrides(sym, origin, types, false)) {
2170 if ((sym.flags() & ABSTRACT) == 0) {
2171 checkOverride(tree, m, (MethodSymbol)sym, origin);
2172 }
2173 }
2174 }
2175 }
2176
2177 private Predicate<Symbol> equalsHasCodeFilter = s -> MethodSymbol.implementation_filter.test(s) &&
2178 (s.flags() & BAD_OVERRIDE) == 0;
2179
2180 public void checkClassOverrideEqualsAndHashIfNeeded(DiagnosticPosition pos,
2181 ClassSymbol someClass) {
2182 /* At present, annotations cannot possibly have a method that is override
2183 * equivalent with Object.equals(Object) but in any case the condition is
2184 * fine for completeness.
2185 */
2186 if (someClass == (ClassSymbol)syms.objectType.tsym ||
2187 someClass.isInterface() || someClass.isEnum() ||
2188 (someClass.flags() & ANNOTATION) != 0 ||
2189 (someClass.flags() & ABSTRACT) != 0) return;
2190 //anonymous inner classes implementing interfaces need especial treatment
2191 if (someClass.isAnonymous()) {
2192 List<Type> interfaces = types.interfaces(someClass.type);
2193 if (interfaces != null && !interfaces.isEmpty() &&
2194 interfaces.head.tsym == syms.comparatorType.tsym) return;
2195 }
2196 checkClassOverrideEqualsAndHash(pos, someClass);
2197 }
2198
2199 private void checkClassOverrideEqualsAndHash(DiagnosticPosition pos,
2200 ClassSymbol someClass) {
2201 if (lint.isEnabled(LintCategory.OVERRIDES)) {
2202 MethodSymbol equalsAtObject = (MethodSymbol)syms.objectType
2203 .tsym.members().findFirst(names.equals);
2204 MethodSymbol hashCodeAtObject = (MethodSymbol)syms.objectType
2205 .tsym.members().findFirst(names.hashCode);
2206 MethodSymbol equalsImpl = types.implementation(equalsAtObject,
2207 someClass, false, equalsHasCodeFilter);
2208 boolean overridesEquals = equalsImpl != null &&
2209 equalsImpl.owner == someClass;
2210 boolean overridesHashCode = types.implementation(hashCodeAtObject,
2211 someClass, false, equalsHasCodeFilter) != hashCodeAtObject;
2212
2213 if (overridesEquals && !overridesHashCode) {
2214 log.warning(pos,
2215 LintWarnings.OverrideEqualsButNotHashcode(someClass));
2216 }
2217 }
2218 }
2219
2220 public void checkHasMain(DiagnosticPosition pos, ClassSymbol c) {
2221 boolean found = false;
2222
2223 for (Symbol sym : c.members().getSymbolsByName(names.main)) {
2224 if (sym.kind == MTH && (sym.flags() & PRIVATE) == 0) {
2225 MethodSymbol meth = (MethodSymbol)sym;
2226 if (!types.isSameType(meth.getReturnType(), syms.voidType)) {
2227 continue;
2228 }
2229 if (meth.params.isEmpty()) {
2230 found = true;
2231 break;
2232 }
2233 if (meth.params.size() != 1) {
2234 continue;
2235 }
2236 if (!types.isSameType(meth.params.head.type, types.makeArrayType(syms.stringType))) {
2237 continue;
2238 }
2239
2240 found = true;
2241 break;
2242 }
2243 }
2244
2245 if (!found) {
2246 log.error(pos, Errors.ImplicitClassDoesNotHaveMainMethod);
2247 }
2248 }
2249
2250 public void checkModuleName (JCModuleDecl tree) {
2251 Name moduleName = tree.sym.name;
2252 Assert.checkNonNull(moduleName);
2253 if (lint.isEnabled(LintCategory.MODULE)) {
2254 JCExpression qualId = tree.qualId;
2255 while (qualId != null) {
2256 Name componentName;
2257 DiagnosticPosition pos;
2258 switch (qualId.getTag()) {
2259 case SELECT:
2260 JCFieldAccess selectNode = ((JCFieldAccess) qualId);
2261 componentName = selectNode.name;
2262 pos = selectNode.pos();
2263 qualId = selectNode.selected;
2264 break;
2265 case IDENT:
2266 componentName = ((JCIdent) qualId).name;
2267 pos = qualId.pos();
2268 qualId = null;
2269 break;
2270 default:
2271 throw new AssertionError("Unexpected qualified identifier: " + qualId.toString());
2272 }
2273 if (componentName != null) {
2274 String moduleNameComponentString = componentName.toString();
2275 int nameLength = moduleNameComponentString.length();
2276 if (nameLength > 0 && Character.isDigit(moduleNameComponentString.charAt(nameLength - 1))) {
2277 log.warning(pos, LintWarnings.PoorChoiceForModuleName(componentName));
2278 }
2279 }
2280 }
2281 }
2282 }
2283
2284 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
2285 ClashFilter cf = new ClashFilter(origin.type);
2286 return (cf.test(s1) &&
2287 cf.test(s2) &&
2288 types.hasSameArgs(s1.erasure(types), s2.erasure(types)));
2289 }
2290
2291
2292 /** Check that all abstract members of given class have definitions.
2293 * @param pos Position to be used for error reporting.
2294 * @param c The class.
2295 */
2296 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
2297 MethodSymbol undef = types.firstUnimplementedAbstract(c);
2298 if (undef != null) {
2299 MethodSymbol undef1 =
2300 new MethodSymbol(undef.flags(), undef.name,
2301 types.memberType(c.type, undef), undef.owner);
2302 log.error(pos,
2303 Errors.DoesNotOverrideAbstract(c, undef1, undef1.location()));
2304 }
2305 }
2306
2307 void checkNonCyclicDecl(JCClassDecl tree) {
2308 CycleChecker cc = new CycleChecker();
2309 cc.scan(tree);
2310 if (!cc.errorFound && !cc.partialCheck) {
2311 tree.sym.flags_field |= ACYCLIC;
2312 }
2313 }
2314
2315 class CycleChecker extends TreeScanner {
2316
2317 Set<Symbol> seenClasses = new HashSet<>();
2318 boolean errorFound = false;
2319 boolean partialCheck = false;
2320
2321 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
2322 if (sym != null && sym.kind == TYP) {
2323 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
2324 if (classEnv != null) {
2325 DiagnosticSource prevSource = log.currentSource();
2326 try {
2327 log.useSource(classEnv.toplevel.sourcefile);
2328 scan(classEnv.tree);
2329 }
2330 finally {
2331 log.useSource(prevSource.getFile());
2332 }
2333 } else if (sym.kind == TYP) {
2334 checkClass(pos, sym, List.nil());
2335 }
2336 } else if (sym == null || sym.kind != PCK) {
2337 //not completed yet
2338 partialCheck = true;
2339 }
2340 }
2341
2342 @Override
2343 public void visitSelect(JCFieldAccess tree) {
2344 super.visitSelect(tree);
2345 checkSymbol(tree.pos(), tree.sym);
2346 }
2347
2348 @Override
2349 public void visitIdent(JCIdent tree) {
2350 checkSymbol(tree.pos(), tree.sym);
2351 }
2352
2353 @Override
2354 public void visitTypeApply(JCTypeApply tree) {
2355 scan(tree.clazz);
2356 }
2357
2358 @Override
2359 public void visitTypeArray(JCArrayTypeTree tree) {
2360 scan(tree.elemtype);
2361 }
2362
2363 @Override
2364 public void visitClassDef(JCClassDecl tree) {
2365 List<JCTree> supertypes = List.nil();
2366 if (tree.getExtendsClause() != null) {
2367 supertypes = supertypes.prepend(tree.getExtendsClause());
2368 }
2369 if (tree.getImplementsClause() != null) {
2370 for (JCTree intf : tree.getImplementsClause()) {
2371 supertypes = supertypes.prepend(intf);
2372 }
2373 }
2374 checkClass(tree.pos(), tree.sym, supertypes);
2375 }
2376
2377 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
2378 if ((c.flags_field & ACYCLIC) != 0)
2379 return;
2380 if (seenClasses.contains(c)) {
2381 errorFound = true;
2382 log.error(pos, Errors.CyclicInheritance(c));
2383 seenClasses.stream()
2384 .filter(s -> !s.type.isErroneous())
2385 .filter(ClassSymbol.class::isInstance)
2386 .map(ClassSymbol.class::cast)
2387 .forEach(Check.this::handleCyclic);
2388 } else if (!c.type.isErroneous()) {
2389 try {
2390 seenClasses.add(c);
2391 if (c.type.hasTag(CLASS)) {
2392 if (supertypes.nonEmpty()) {
2393 scan(supertypes);
2394 }
2395 else {
2396 ClassType ct = (ClassType)c.type;
2397 if (ct.supertype_field == null ||
2398 ct.interfaces_field == null) {
2399 //not completed yet
2400 partialCheck = true;
2401 return;
2402 }
2403 checkSymbol(pos, ct.supertype_field.tsym);
2404 for (Type intf : ct.interfaces_field) {
2405 checkSymbol(pos, intf.tsym);
2406 }
2407 }
2408 if (c.owner.kind == TYP) {
2409 checkSymbol(pos, c.owner);
2410 }
2411 }
2412 } finally {
2413 seenClasses.remove(c);
2414 }
2415 }
2416 }
2417 }
2418
2419 /** Check for cyclic references. Issue an error if the
2420 * symbol of the type referred to has a LOCKED flag set.
2421 *
2422 * @param pos Position to be used for error reporting.
2423 * @param t The type referred to.
2424 */
2425 void checkNonCyclic(DiagnosticPosition pos, Type t) {
2426 checkNonCyclicInternal(pos, t);
2427 }
2428
2429
2430 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
2431 checkNonCyclic1(pos, t, List.nil());
2432 }
2433
2434 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
2435 final TypeVar tv;
2436 if (t.hasTag(TYPEVAR) && (t.tsym.flags() & UNATTRIBUTED) != 0)
2437 return;
2438 if (seen.contains(t)) {
2439 tv = (TypeVar)t;
2440 tv.setUpperBound(types.createErrorType(t));
2441 log.error(pos, Errors.CyclicInheritance(t));
2442 } else if (t.hasTag(TYPEVAR)) {
2443 tv = (TypeVar)t;
2444 seen = seen.prepend(tv);
2445 for (Type b : types.getBounds(tv))
2446 checkNonCyclic1(pos, b, seen);
2447 }
2448 }
2449
2450 /** Check for cyclic references. Issue an error if the
2451 * symbol of the type referred to has a LOCKED flag set.
2452 *
2453 * @param pos Position to be used for error reporting.
2454 * @param t The type referred to.
2455 * @return True if the check completed on all attributed classes
2456 */
2457 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
2458 boolean complete = true; // was the check complete?
2459 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
2460 Symbol c = t.tsym;
2461 if ((c.flags_field & ACYCLIC) != 0) return true;
2462
2463 if ((c.flags_field & LOCKED) != 0) {
2464 log.error(pos, Errors.CyclicInheritance(c));
2465 handleCyclic((ClassSymbol)c);
2466 } else if (!c.type.isErroneous()) {
2467 try {
2468 c.flags_field |= LOCKED;
2469 if (c.type.hasTag(CLASS)) {
2470 ClassType clazz = (ClassType)c.type;
2471 if (clazz.interfaces_field != null)
2472 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
2473 complete &= checkNonCyclicInternal(pos, l.head);
2474 if (clazz.supertype_field != null) {
2475 Type st = clazz.supertype_field;
2476 if (st != null && st.hasTag(CLASS))
2477 complete &= checkNonCyclicInternal(pos, st);
2478 }
2479 if (c.owner.kind == TYP)
2480 complete &= checkNonCyclicInternal(pos, c.owner.type);
2481 }
2482 } finally {
2483 c.flags_field &= ~LOCKED;
2484 }
2485 }
2486 if (complete)
2487 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.isCompleted();
2488 if (complete) c.flags_field |= ACYCLIC;
2489 return complete;
2490 }
2491
2492 /** Handle finding an inheritance cycle on a class by setting
2493 * the class' and its supertypes' types to the error type.
2494 **/
2495 private void handleCyclic(ClassSymbol c) {
2496 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
2497 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
2498 Type st = types.supertype(c.type);
2499 if (st.hasTag(CLASS))
2500 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2501 c.type = types.createErrorType(c, c.type);
2502 c.flags_field |= ACYCLIC;
2503 }
2504
2505 /** Check that all methods which implement some
2506 * method conform to the method they implement.
2507 * @param tree The class definition whose members are checked.
2508 */
2509 void checkImplementations(JCClassDecl tree) {
2510 checkImplementations(tree, tree.sym, tree.sym);
2511 }
2512 //where
2513 /** Check that all methods which implement some
2514 * method in `ic' conform to the method they implement.
2515 */
2516 void checkImplementations(JCTree tree, ClassSymbol origin, ClassSymbol ic) {
2517 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2518 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2519 if ((lc.flags() & ABSTRACT) != 0) {
2520 for (Symbol sym : lc.members().getSymbols(NON_RECURSIVE)) {
2521 if (sym.kind == MTH &&
2522 (sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2523 MethodSymbol absmeth = (MethodSymbol)sym;
2524 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2525 if (implmeth != null && implmeth != absmeth &&
2526 (implmeth.owner.flags() & INTERFACE) ==
2527 (origin.flags() & INTERFACE)) {
2528 // don't check if implmeth is in a class, yet
2529 // origin is an interface. This case arises only
2530 // if implmeth is declared in Object. The reason is
2531 // that interfaces really don't inherit from
2532 // Object it's just that the compiler represents
2533 // things that way.
2534 checkOverride(tree, implmeth, absmeth, origin);
2535 }
2536 }
2537 }
2538 }
2539 }
2540 }
2541
2542 /** Check that all abstract methods implemented by a class are
2543 * mutually compatible.
2544 * @param pos Position to be used for error reporting.
2545 * @param c The class whose interfaces are checked.
2546 */
2547 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2548 List<Type> supertypes = types.interfaces(c);
2549 Type supertype = types.supertype(c);
2550 if (supertype.hasTag(CLASS) &&
2551 (supertype.tsym.flags() & ABSTRACT) != 0)
2552 supertypes = supertypes.prepend(supertype);
2553 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2554 if (!l.head.getTypeArguments().isEmpty() &&
2555 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2556 return;
2557 for (List<Type> m = supertypes; m != l; m = m.tail)
2558 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2559 return;
2560 }
2561 checkCompatibleConcretes(pos, c);
2562 }
2563
2564 /** Check that all non-override equivalent methods accessible from 'site'
2565 * are mutually compatible (JLS 8.4.8/9.4.1).
2566 *
2567 * @param pos Position to be used for error reporting.
2568 * @param site The class whose methods are checked.
2569 * @param sym The method symbol to be checked.
2570 */
2571 void checkOverrideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2572 ClashFilter cf = new ClashFilter(site);
2573 //for each method m1 that is overridden (directly or indirectly)
2574 //by method 'sym' in 'site'...
2575
2576 ArrayList<Symbol> symbolsByName = new ArrayList<>();
2577 types.membersClosure(site, false).getSymbolsByName(sym.name, cf).forEach(symbolsByName::add);
2578 for (Symbol m1 : symbolsByName) {
2579 if (!sym.overrides(m1, site.tsym, types, false)) {
2580 continue;
2581 }
2582
2583 //...check each method m2 that is a member of 'site'
2584 for (Symbol m2 : symbolsByName) {
2585 if (m2 == m1) continue;
2586 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2587 //a member of 'site') and (ii) m1 has the same erasure as m2, issue an error
2588 if (!types.isSubSignature(sym.type, types.memberType(site, m2)) &&
2589 types.hasSameArgs(m2.erasure(types), m1.erasure(types))) {
2590 sym.flags_field |= CLASH;
2591 if (m1 == sym) {
2592 log.error(pos, Errors.NameClashSameErasureNoOverride(
2593 m1.name, types.memberType(site, m1).asMethodType().getParameterTypes(), m1.location(),
2594 m2.name, types.memberType(site, m2).asMethodType().getParameterTypes(), m2.location()));
2595 } else {
2596 ClassType ct = (ClassType)site;
2597 String kind = ct.isInterface() ? "interface" : "class";
2598 log.error(pos, Errors.NameClashSameErasureNoOverride1(
2599 kind,
2600 ct.tsym.name,
2601 m1.name,
2602 types.memberType(site, m1).asMethodType().getParameterTypes(),
2603 m1.location(),
2604 m2.name,
2605 types.memberType(site, m2).asMethodType().getParameterTypes(),
2606 m2.location()));
2607 }
2608 return;
2609 }
2610 }
2611 }
2612 }
2613
2614 /** Check that all static methods accessible from 'site' are
2615 * mutually compatible (JLS 8.4.8).
2616 *
2617 * @param pos Position to be used for error reporting.
2618 * @param site The class whose methods are checked.
2619 * @param sym The method symbol to be checked.
2620 */
2621 void checkHideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2622 ClashFilter cf = new ClashFilter(site);
2623 //for each method m1 that is a member of 'site'...
2624 for (Symbol s : types.membersClosure(site, true).getSymbolsByName(sym.name, cf)) {
2625 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2626 //a member of 'site') and (ii) 'sym' has the same erasure as m1, issue an error
2627 if (!types.isSubSignature(sym.type, types.memberType(site, s))) {
2628 if (types.hasSameArgs(s.erasure(types), sym.erasure(types))) {
2629 log.error(pos,
2630 Errors.NameClashSameErasureNoHide(sym, sym.location(), s, s.location()));
2631 return;
2632 }
2633 }
2634 }
2635 }
2636
2637 //where
2638 private class ClashFilter implements Predicate<Symbol> {
2639
2640 Type site;
2641
2642 ClashFilter(Type site) {
2643 this.site = site;
2644 }
2645
2646 boolean shouldSkip(Symbol s) {
2647 return (s.flags() & CLASH) != 0 &&
2648 s.owner == site.tsym;
2649 }
2650
2651 @Override
2652 public boolean test(Symbol s) {
2653 return s.kind == MTH &&
2654 (s.flags() & SYNTHETIC) == 0 &&
2655 !shouldSkip(s) &&
2656 s.isInheritedIn(site.tsym, types) &&
2657 !s.isConstructor();
2658 }
2659 }
2660
2661 void checkDefaultMethodClashes(DiagnosticPosition pos, Type site) {
2662 DefaultMethodClashFilter dcf = new DefaultMethodClashFilter(site);
2663 for (Symbol m : types.membersClosure(site, false).getSymbols(dcf)) {
2664 Assert.check(m.kind == MTH);
2665 List<MethodSymbol> prov = types.interfaceCandidates(site, (MethodSymbol)m);
2666 if (prov.size() > 1) {
2667 ListBuffer<Symbol> abstracts = new ListBuffer<>();
2668 ListBuffer<Symbol> defaults = new ListBuffer<>();
2669 for (MethodSymbol provSym : prov) {
2670 if ((provSym.flags() & DEFAULT) != 0) {
2671 defaults = defaults.append(provSym);
2672 } else if ((provSym.flags() & ABSTRACT) != 0) {
2673 abstracts = abstracts.append(provSym);
2674 }
2675 if (defaults.nonEmpty() && defaults.size() + abstracts.size() >= 2) {
2676 //strong semantics - issue an error if two sibling interfaces
2677 //have two override-equivalent defaults - or if one is abstract
2678 //and the other is default
2679 Fragment diagKey;
2680 Symbol s1 = defaults.first();
2681 Symbol s2;
2682 if (defaults.size() > 1) {
2683 s2 = defaults.toList().tail.head;
2684 diagKey = Fragments.IncompatibleUnrelatedDefaults(Kinds.kindName(site.tsym), site,
2685 m.name, types.memberType(site, m).getParameterTypes(),
2686 s1.location(), s2.location());
2687
2688 } else {
2689 s2 = abstracts.first();
2690 diagKey = Fragments.IncompatibleAbstractDefault(Kinds.kindName(site.tsym), site,
2691 m.name, types.memberType(site, m).getParameterTypes(),
2692 s1.location(), s2.location());
2693 }
2694 log.error(pos, Errors.TypesIncompatible(s1.location().type, s2.location().type, diagKey));
2695 break;
2696 }
2697 }
2698 }
2699 }
2700 }
2701
2702 //where
2703 private class DefaultMethodClashFilter implements Predicate<Symbol> {
2704
2705 Type site;
2706
2707 DefaultMethodClashFilter(Type site) {
2708 this.site = site;
2709 }
2710
2711 @Override
2712 public boolean test(Symbol s) {
2713 return s.kind == MTH &&
2714 (s.flags() & DEFAULT) != 0 &&
2715 s.isInheritedIn(site.tsym, types) &&
2716 !s.isConstructor();
2717 }
2718 }
2719
2720 /** Report warnings for potentially ambiguous method declarations in the given site. */
2721 void checkPotentiallyAmbiguousOverloads(JCClassDecl tree, Type site) {
2722
2723 // Skip if warning not enabled
2724 if (!lint.isEnabled(LintCategory.OVERLOADS))
2725 return;
2726
2727 // Gather all of site's methods, including overridden methods, grouped by name (except Object methods)
2728 List<java.util.List<MethodSymbol>> methodGroups = methodsGroupedByName(site,
2729 new PotentiallyAmbiguousFilter(site), ArrayList::new);
2730
2731 // Build the predicate that determines if site is responsible for an ambiguity
2732 BiPredicate<MethodSymbol, MethodSymbol> responsible = buildResponsiblePredicate(site, methodGroups);
2733
2734 // Now remove overridden methods from each group, leaving only site's actual members
2735 methodGroups.forEach(list -> removePreempted(list, (m1, m2) -> m1.overrides(m2, site.tsym, types, false)));
2736
2737 // Allow site's own declared methods (only) to apply @SuppressWarnings("overloads")
2738 methodGroups.forEach(list -> list.removeIf(
2739 m -> m.owner == site.tsym && !lint.augment(m).isEnabled(LintCategory.OVERLOADS)));
2740
2741 // Warn about ambiguous overload method pairs for which site is responsible
2742 methodGroups.forEach(list -> compareAndRemove(list, (m1, m2) -> {
2743
2744 // See if this is an ambiguous overload for which "site" is responsible
2745 if (!potentiallyAmbiguousOverload(site, m1, m2) || !responsible.test(m1, m2))
2746 return 0;
2747
2748 // Locate the warning at one of the methods, if possible
2749 DiagnosticPosition pos =
2750 m1.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m1, tree) :
2751 m2.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m2, tree) :
2752 tree.pos();
2753
2754 // Log the warning
2755 log.warning(pos,
2756 LintWarnings.PotentiallyAmbiguousOverload(
2757 m1.asMemberOf(site, types), m1.location(),
2758 m2.asMemberOf(site, types), m2.location()));
2759
2760 // Don't warn again for either of these two methods
2761 return FIRST | SECOND;
2762 }));
2763 }
2764
2765 /** Build a predicate that determines, given two methods that are members of the given class,
2766 * whether the class should be held "responsible" if the methods are potentially ambiguous.
2767 *
2768 * Sometimes ambiguous methods are unavoidable because they're inherited from a supertype.
2769 * For example, any subtype of Spliterator.OfInt will have ambiguities for both
2770 * forEachRemaining() and tryAdvance() (in both cases the overloads are IntConsumer and
2771 * Consumer<? super Integer>). So we only want to "blame" a class when that class is
2772 * itself responsible for creating the ambiguity. We declare that a class C is "responsible"
2773 * for the ambiguity between two methods m1 and m2 if there is no direct supertype T of C
2774 * such that m1 and m2, or some overrides thereof, both exist in T and are ambiguous in T.
2775 * As an optimization, we first check if either method is declared in C and does not override
2776 * any other methods; in this case the class is definitely responsible.
2777 */
2778 BiPredicate<MethodSymbol, MethodSymbol> buildResponsiblePredicate(Type site,
2779 List<? extends Collection<MethodSymbol>> methodGroups) {
2780
2781 // Define the "overrides" predicate
2782 BiPredicate<MethodSymbol, MethodSymbol> overrides = (m1, m2) -> m1.overrides(m2, site.tsym, types, false);
2783
2784 // Map each method declared in site to a list of the supertype method(s) it directly overrides
2785 HashMap<MethodSymbol, ArrayList<MethodSymbol>> overriddenMethodsMap = new HashMap<>();
2786 methodGroups.forEach(list -> {
2787 for (MethodSymbol m : list) {
2788
2789 // Skip methods not declared in site
2790 if (m.owner != site.tsym)
2791 continue;
2792
2793 // Gather all supertype methods overridden by m, directly or indirectly
2794 ArrayList<MethodSymbol> overriddenMethods = list.stream()
2795 .filter(m2 -> m2 != m && overrides.test(m, m2))
2796 .collect(Collectors.toCollection(ArrayList::new));
2797
2798 // Eliminate non-direct overrides
2799 removePreempted(overriddenMethods, overrides);
2800
2801 // Add to map
2802 overriddenMethodsMap.put(m, overriddenMethods);
2803 }
2804 });
2805
2806 // Build the predicate
2807 return (m1, m2) -> {
2808
2809 // Get corresponding supertype methods (if declared in site)
2810 java.util.List<MethodSymbol> overriddenMethods1 = overriddenMethodsMap.get(m1);
2811 java.util.List<MethodSymbol> overriddenMethods2 = overriddenMethodsMap.get(m2);
2812
2813 // Quick check for the case where a method was added by site itself
2814 if (overriddenMethods1 != null && overriddenMethods1.isEmpty())
2815 return true;
2816 if (overriddenMethods2 != null && overriddenMethods2.isEmpty())
2817 return true;
2818
2819 // Get each method's corresponding method(s) from supertypes of site
2820 java.util.List<MethodSymbol> supertypeMethods1 = overriddenMethods1 != null ?
2821 overriddenMethods1 : Collections.singletonList(m1);
2822 java.util.List<MethodSymbol> supertypeMethods2 = overriddenMethods2 != null ?
2823 overriddenMethods2 : Collections.singletonList(m2);
2824
2825 // See if we can blame some direct supertype instead
2826 return types.directSupertypes(site).stream()
2827 .filter(stype -> stype != syms.objectType)
2828 .map(stype -> stype.tsym.type) // view supertype in its original form
2829 .noneMatch(stype -> {
2830 for (MethodSymbol sm1 : supertypeMethods1) {
2831 if (!types.isSubtype(types.erasure(stype), types.erasure(sm1.owner.type)))
2832 continue;
2833 for (MethodSymbol sm2 : supertypeMethods2) {
2834 if (!types.isSubtype(types.erasure(stype), types.erasure(sm2.owner.type)))
2835 continue;
2836 if (potentiallyAmbiguousOverload(stype, sm1, sm2))
2837 return true;
2838 }
2839 }
2840 return false;
2841 });
2842 };
2843 }
2844
2845 /** Gather all of site's methods, including overridden methods, grouped and sorted by name,
2846 * after applying the given filter.
2847 */
2848 <C extends Collection<MethodSymbol>> List<C> methodsGroupedByName(Type site,
2849 Predicate<Symbol> filter, Supplier<? extends C> groupMaker) {
2850 Iterable<Symbol> symbols = types.membersClosure(site, false).getSymbols(filter, RECURSIVE);
2851 return StreamSupport.stream(symbols.spliterator(), false)
2852 .map(MethodSymbol.class::cast)
2853 .collect(Collectors.groupingBy(m -> m.name, Collectors.toCollection(groupMaker)))
2854 .entrySet()
2855 .stream()
2856 .sorted(Comparator.comparing(e -> e.getKey().toString()))
2857 .map(Map.Entry::getValue)
2858 .collect(List.collector());
2859 }
2860
2861 /** Compare elements in a list pair-wise in order to remove some of them.
2862 * @param list mutable list of items
2863 * @param comparer returns flag bit(s) to remove FIRST and/or SECOND
2864 */
2865 <T> void compareAndRemove(java.util.List<T> list, ToIntBiFunction<? super T, ? super T> comparer) {
2866 for (int index1 = 0; index1 < list.size() - 1; index1++) {
2867 T item1 = list.get(index1);
2868 for (int index2 = index1 + 1; index2 < list.size(); index2++) {
2869 T item2 = list.get(index2);
2870 int flags = comparer.applyAsInt(item1, item2);
2871 if ((flags & SECOND) != 0)
2872 list.remove(index2--); // remove item2
2873 if ((flags & FIRST) != 0) {
2874 list.remove(index1--); // remove item1
2875 break;
2876 }
2877 }
2878 }
2879 }
2880
2881 /** Remove elements in a list that are preempted by some other element in the list.
2882 * @param list mutable list of items
2883 * @param preempts decides if one item preempts another, causing the second one to be removed
2884 */
2885 <T> void removePreempted(java.util.List<T> list, BiPredicate<? super T, ? super T> preempts) {
2886 compareAndRemove(list, (item1, item2) -> {
2887 int flags = 0;
2888 if (preempts.test(item1, item2))
2889 flags |= SECOND;
2890 if (preempts.test(item2, item1))
2891 flags |= FIRST;
2892 return flags;
2893 });
2894 }
2895
2896 /** Filters method candidates for the "potentially ambiguous method" check */
2897 class PotentiallyAmbiguousFilter extends ClashFilter {
2898
2899 PotentiallyAmbiguousFilter(Type site) {
2900 super(site);
2901 }
2902
2903 @Override
2904 boolean shouldSkip(Symbol s) {
2905 return s.owner.type.tsym == syms.objectType.tsym || super.shouldSkip(s);
2906 }
2907 }
2908
2909 /**
2910 * Report warnings for potentially ambiguous method declarations. Two declarations
2911 * are potentially ambiguous if they feature two unrelated functional interface
2912 * in same argument position (in which case, a call site passing an implicit
2913 * lambda would be ambiguous). This assumes they already have the same name.
2914 */
2915 boolean potentiallyAmbiguousOverload(Type site, MethodSymbol msym1, MethodSymbol msym2) {
2916 Assert.check(msym1.name == msym2.name);
2917 if (msym1 == msym2)
2918 return false;
2919 Type mt1 = types.memberType(site, msym1);
2920 Type mt2 = types.memberType(site, msym2);
2921 //if both generic methods, adjust type variables
2922 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL) &&
2923 types.hasSameBounds((ForAll)mt1, (ForAll)mt2)) {
2924 mt2 = types.subst(mt2, ((ForAll)mt2).tvars, ((ForAll)mt1).tvars);
2925 }
2926 //expand varargs methods if needed
2927 int maxLength = Math.max(mt1.getParameterTypes().length(), mt2.getParameterTypes().length());
2928 List<Type> args1 = rs.adjustArgs(mt1.getParameterTypes(), msym1, maxLength, true);
2929 List<Type> args2 = rs.adjustArgs(mt2.getParameterTypes(), msym2, maxLength, true);
2930 //if arities don't match, exit
2931 if (args1.length() != args2.length())
2932 return false;
2933 boolean potentiallyAmbiguous = false;
2934 while (args1.nonEmpty() && args2.nonEmpty()) {
2935 Type s = args1.head;
2936 Type t = args2.head;
2937 if (!types.isSubtype(t, s) && !types.isSubtype(s, t)) {
2938 if (types.isFunctionalInterface(s) && types.isFunctionalInterface(t) &&
2939 types.findDescriptorType(s).getParameterTypes().length() > 0 &&
2940 types.findDescriptorType(s).getParameterTypes().length() ==
2941 types.findDescriptorType(t).getParameterTypes().length()) {
2942 potentiallyAmbiguous = true;
2943 } else {
2944 return false;
2945 }
2946 }
2947 args1 = args1.tail;
2948 args2 = args2.tail;
2949 }
2950 return potentiallyAmbiguous;
2951 }
2952
2953 // Apply special flag "-XDwarnOnAccessToMembers" which turns on just this particular warning for all types of access
2954 void checkAccessFromSerializableElement(final JCTree tree, boolean isLambda) {
2955 final Lint prevLint = setLint(warnOnAnyAccessToMembers ? lint.enable(LintCategory.SERIAL) : lint);
2956 try {
2957 if (warnOnAnyAccessToMembers || isLambda)
2958 checkAccessFromSerializableElementInner(tree, isLambda);
2959 } finally {
2960 setLint(prevLint);
2961 }
2962 }
2963
2964 private void checkAccessFromSerializableElementInner(final JCTree tree, boolean isLambda) {
2965 if (lint.isEnabled(LintCategory.SERIAL)) {
2966 Symbol sym = TreeInfo.symbol(tree);
2967 if (!sym.kind.matches(KindSelector.VAL_MTH)) {
2968 return;
2969 }
2970
2971 if (sym.kind == VAR) {
2972 if ((sym.flags() & PARAMETER) != 0 ||
2973 sym.isDirectlyOrIndirectlyLocal() ||
2974 sym.name == names._this ||
2975 sym.name == names._super) {
2976 return;
2977 }
2978 }
2979
2980 if (!types.isSubtype(sym.owner.type, syms.serializableType) &&
2981 isEffectivelyNonPublic(sym)) {
2982 if (isLambda) {
2983 if (belongsToRestrictedPackage(sym)) {
2984 log.warning(tree.pos(),
2985 LintWarnings.AccessToMemberFromSerializableLambda(sym));
2986 }
2987 } else {
2988 log.warning(tree.pos(),
2989 LintWarnings.AccessToMemberFromSerializableElement(sym));
2990 }
2991 }
2992 }
2993 }
2994
2995 private boolean isEffectivelyNonPublic(Symbol sym) {
2996 if (sym.packge() == syms.rootPackage) {
2997 return false;
2998 }
2999
3000 while (sym.kind != PCK) {
3001 if ((sym.flags() & PUBLIC) == 0) {
3002 return true;
3003 }
3004 sym = sym.owner;
3005 }
3006 return false;
3007 }
3008
3009 private boolean belongsToRestrictedPackage(Symbol sym) {
3010 String fullName = sym.packge().fullname.toString();
3011 return fullName.startsWith("java.") ||
3012 fullName.startsWith("javax.") ||
3013 fullName.startsWith("sun.") ||
3014 fullName.contains(".internal.");
3015 }
3016
3017 /** Check that class c does not implement directly or indirectly
3018 * the same parameterized interface with two different argument lists.
3019 * @param pos Position to be used for error reporting.
3020 * @param type The type whose interfaces are checked.
3021 */
3022 void checkClassBounds(DiagnosticPosition pos, Type type) {
3023 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
3024 }
3025 //where
3026 /** Enter all interfaces of type `type' into the hash table `seensofar'
3027 * with their class symbol as key and their type as value. Make
3028 * sure no class is entered with two different types.
3029 */
3030 void checkClassBounds(DiagnosticPosition pos,
3031 Map<TypeSymbol,Type> seensofar,
3032 Type type) {
3033 if (type.isErroneous()) return;
3034 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
3035 Type it = l.head;
3036 if (type.hasTag(CLASS) && !it.hasTag(CLASS)) continue; // JLS 8.1.5
3037
3038 Type oldit = seensofar.put(it.tsym, it);
3039 if (oldit != null) {
3040 List<Type> oldparams = oldit.allparams();
3041 List<Type> newparams = it.allparams();
3042 if (!types.containsTypeEquivalent(oldparams, newparams))
3043 log.error(pos,
3044 Errors.CantInheritDiffArg(it.tsym,
3045 Type.toString(oldparams),
3046 Type.toString(newparams)));
3047 }
3048 checkClassBounds(pos, seensofar, it);
3049 }
3050 Type st = types.supertype(type);
3051 if (type.hasTag(CLASS) && !st.hasTag(CLASS)) return; // JLS 8.1.4
3052 if (st != Type.noType) checkClassBounds(pos, seensofar, st);
3053 }
3054
3055 /** Enter interface into into set.
3056 * If it existed already, issue a "repeated interface" error.
3057 */
3058 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Symbol> its) {
3059 if (its.contains(it.tsym))
3060 log.error(pos, Errors.RepeatedInterface);
3061 else {
3062 its.add(it.tsym);
3063 }
3064 }
3065
3066 /* *************************************************************************
3067 * Check annotations
3068 **************************************************************************/
3069
3070 /**
3071 * Recursively validate annotations values
3072 */
3073 void validateAnnotationTree(JCTree tree) {
3074 class AnnotationValidator extends TreeScanner {
3075 @Override
3076 public void visitAnnotation(JCAnnotation tree) {
3077 if (!tree.type.isErroneous() && tree.type.tsym.isAnnotationType()) {
3078 super.visitAnnotation(tree);
3079 validateAnnotation(tree);
3080 }
3081 }
3082 }
3083 tree.accept(new AnnotationValidator());
3084 }
3085
3086 /**
3087 * {@literal
3088 * Annotation types are restricted to primitives, String, an
3089 * enum, an annotation, Class, Class<?>, Class<? extends
3090 * Anything>, arrays of the preceding.
3091 * }
3092 */
3093 void validateAnnotationType(JCTree restype) {
3094 // restype may be null if an error occurred, so don't bother validating it
3095 if (restype != null) {
3096 validateAnnotationType(restype.pos(), restype.type);
3097 }
3098 }
3099
3100 void validateAnnotationType(DiagnosticPosition pos, Type type) {
3101 if (type.isPrimitive()) return;
3102 if (types.isSameType(type, syms.stringType)) return;
3103 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
3104 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
3105 if (types.cvarLowerBound(type).tsym == syms.classType.tsym) return;
3106 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
3107 validateAnnotationType(pos, types.elemtype(type));
3108 return;
3109 }
3110 log.error(pos, Errors.InvalidAnnotationMemberType);
3111 }
3112
3113 /**
3114 * "It is also a compile-time error if any method declared in an
3115 * annotation type has a signature that is override-equivalent to
3116 * that of any public or protected method declared in class Object
3117 * or in the interface annotation.Annotation."
3118 *
3119 * @jls 9.6 Annotation Types
3120 */
3121 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
3122 for (Type sup = syms.annotationType; sup.hasTag(CLASS); sup = types.supertype(sup)) {
3123 Scope s = sup.tsym.members();
3124 for (Symbol sym : s.getSymbolsByName(m.name)) {
3125 if (sym.kind == MTH &&
3126 (sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
3127 types.overrideEquivalent(m.type, sym.type))
3128 log.error(pos, Errors.IntfAnnotationMemberClash(sym, sup));
3129 }
3130 }
3131 }
3132
3133 /** Check the annotations of a symbol.
3134 */
3135 public void validateAnnotations(List<JCAnnotation> annotations, JCTree declarationTree, Symbol s) {
3136 for (JCAnnotation a : annotations)
3137 validateAnnotation(a, declarationTree, s);
3138 }
3139
3140 /** Check the type annotations.
3141 */
3142 public void validateTypeAnnotations(List<JCAnnotation> annotations, Symbol s, boolean isTypeParameter) {
3143 for (JCAnnotation a : annotations)
3144 validateTypeAnnotation(a, s, isTypeParameter);
3145 }
3146
3147 /** Check an annotation of a symbol.
3148 */
3149 private void validateAnnotation(JCAnnotation a, JCTree declarationTree, Symbol s) {
3150 /** NOTE: if annotation processors are present, annotation processing rounds can happen after this method,
3151 * this can impact in particular records for which annotations are forcibly propagated.
3152 */
3153 validateAnnotationTree(a);
3154 boolean isRecordMember = ((s.flags_field & RECORD) != 0 || s.enclClass() != null && s.enclClass().isRecord());
3155
3156 boolean isRecordField = (s.flags_field & RECORD) != 0 &&
3157 declarationTree.hasTag(VARDEF) &&
3158 s.owner.kind == TYP;
3159
3160 if (isRecordField) {
3161 // first we need to check if the annotation is applicable to records
3162 Name[] targets = getTargetNames(a);
3163 boolean appliesToRecords = false;
3164 for (Name target : targets) {
3165 appliesToRecords =
3166 target == names.FIELD ||
3167 target == names.PARAMETER ||
3168 target == names.METHOD ||
3169 target == names.TYPE_USE ||
3170 target == names.RECORD_COMPONENT;
3171 if (appliesToRecords) {
3172 break;
3173 }
3174 }
3175 if (!appliesToRecords) {
3176 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3177 } else {
3178 /* lets now find the annotations in the field that are targeted to record components and append them to
3179 * the corresponding record component
3180 */
3181 ClassSymbol recordClass = (ClassSymbol) s.owner;
3182 RecordComponent rc = recordClass.getRecordComponent((VarSymbol)s);
3183 SymbolMetadata metadata = rc.getMetadata();
3184 if (metadata == null || metadata.isEmpty()) {
3185 /* if not is empty then we have already been here, which is the case if multiple annotations are applied
3186 * to the record component declaration
3187 */
3188 rc.appendAttributes(s.getRawAttributes().stream().filter(anno ->
3189 Arrays.stream(getTargetNames(anno.type.tsym)).anyMatch(name -> name == names.RECORD_COMPONENT)
3190 ).collect(List.collector()));
3191
3192 JCVariableDecl fieldAST = (JCVariableDecl) declarationTree;
3193 for (JCAnnotation fieldAnnot : fieldAST.mods.annotations) {
3194 for (JCAnnotation rcAnnot : rc.declarationFor().mods.annotations) {
3195 if (rcAnnot.pos == fieldAnnot.pos) {
3196 rcAnnot.setType(fieldAnnot.type);
3197 break;
3198 }
3199 }
3200 }
3201
3202 /* At this point, we used to carry over any type annotations from the VARDEF to the record component, but
3203 * that is problematic, since we get here only when *some* annotation is applied to the SE5 (declaration)
3204 * annotation location, inadvertently failing to carry over the type annotations when the VarDef has no
3205 * annotations in the SE5 annotation location.
3206 *
3207 * Now type annotations are assigned to record components in a method that would execute irrespective of
3208 * whether there are SE5 annotations on a VarDef viz com.sun.tools.javac.code.TypeAnnotations.TypeAnnotationPositions.visitVarDef
3209 */
3210 }
3211 }
3212 }
3213
3214 /* the section below is tricky. Annotations applied to record components are propagated to the corresponding
3215 * record member so if an annotation has target: FIELD, it is propagated to the corresponding FIELD, if it has
3216 * target METHOD, it is propagated to the accessor and so on. But at the moment when method members are generated
3217 * there is no enough information to propagate only the right annotations. So all the annotations are propagated
3218 * to all the possible locations.
3219 *
3220 * At this point we need to remove all the annotations that are not in place before going on with the annotation
3221 * party. On top of the above there is the issue that there is no AST representing record components, just symbols
3222 * so the corresponding field has been holding all the annotations and it's metadata has been modified as if it
3223 * was both a field and a record component.
3224 *
3225 * So there are two places where we need to trim annotations from: the metadata of the symbol and / or the modifiers
3226 * in the AST. Whatever is in the metadata will be written to the class file, whatever is in the modifiers could
3227 * be see by annotation processors.
3228 *
3229 * The metadata contains both type annotations and declaration annotations. At this point of the game we don't
3230 * need to care about type annotations, they are all in the right place. But we could need to remove declaration
3231 * annotations. So for declaration annotations if they are not applicable to the record member, excluding type
3232 * annotations which are already correct, then we will remove it. For the AST modifiers if the annotation is not
3233 * applicable either as type annotation and or declaration annotation, only in that case it will be removed.
3234 *
3235 * So it could be that annotation is removed as a declaration annotation but it is kept in the AST modifier for
3236 * further inspection by annotation processors.
3237 *
3238 * For example:
3239 *
3240 * import java.lang.annotation.*;
3241 *
3242 * @Target({ElementType.TYPE_USE, ElementType.RECORD_COMPONENT})
3243 * @Retention(RetentionPolicy.RUNTIME)
3244 * @interface Anno { }
3245 *
3246 * record R(@Anno String s) {}
3247 *
3248 * at this point we will have for the case of the generated field:
3249 * - @Anno in the modifier
3250 * - @Anno as a type annotation
3251 * - @Anno as a declaration annotation
3252 *
3253 * the last one should be removed because the annotation has not FIELD as target but it was applied as a
3254 * declaration annotation because the field was being treated both as a field and as a record component
3255 * as we have already copied the annotations to the record component, now the field doesn't need to hold
3256 * annotations that are not intended for it anymore. Still @Anno has to be kept in the AST's modifiers as it
3257 * is applicable as a type annotation to the type of the field.
3258 */
3259
3260 if (a.type.tsym.isAnnotationType()) {
3261 Optional<Set<Name>> applicableTargetsOp = getApplicableTargets(a, s);
3262 if (!applicableTargetsOp.isEmpty()) {
3263 Set<Name> applicableTargets = applicableTargetsOp.get();
3264 boolean notApplicableOrIsTypeUseOnly = applicableTargets.isEmpty() ||
3265 applicableTargets.size() == 1 && applicableTargets.contains(names.TYPE_USE);
3266 boolean isCompGeneratedRecordElement = isRecordMember && (s.flags_field & Flags.GENERATED_MEMBER) != 0;
3267 boolean isCompRecordElementWithNonApplicableDeclAnno = isCompGeneratedRecordElement && notApplicableOrIsTypeUseOnly;
3268
3269 if (applicableTargets.isEmpty() || isCompRecordElementWithNonApplicableDeclAnno) {
3270 if (isCompRecordElementWithNonApplicableDeclAnno) {
3271 /* so we have found an annotation that is not applicable to a record member that was generated by the
3272 * compiler. This was intentionally done at TypeEnter, now is the moment strip away the annotations
3273 * that are not applicable to the given record member
3274 */
3275 JCModifiers modifiers = TreeInfo.getModifiers(declarationTree);
3276 /* lets first remove the annotation from the modifier if it is not applicable, we have to check again as
3277 * it could be a type annotation
3278 */
3279 if (modifiers != null && applicableTargets.isEmpty()) {
3280 ListBuffer<JCAnnotation> newAnnotations = new ListBuffer<>();
3281 for (JCAnnotation anno : modifiers.annotations) {
3282 if (anno != a) {
3283 newAnnotations.add(anno);
3284 }
3285 }
3286 modifiers.annotations = newAnnotations.toList();
3287 }
3288 // now lets remove it from the symbol
3289 s.getMetadata().removeDeclarationMetadata(a.attribute);
3290 } else {
3291 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3292 }
3293 }
3294 /* if we are seeing the @SafeVarargs annotation applied to a compiler generated accessor,
3295 * then this is an error as we know that no compiler generated accessor will be a varargs
3296 * method, better to fail asap
3297 */
3298 if (isCompGeneratedRecordElement && !isRecordField && a.type.tsym == syms.trustMeType.tsym && declarationTree.hasTag(METHODDEF)) {
3299 log.error(a.pos(), Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym, Fragments.VarargsTrustmeOnNonVarargsAccessor(s)));
3300 }
3301 }
3302 }
3303
3304 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
3305 if (s.kind != TYP) {
3306 log.error(a.pos(), Errors.BadFunctionalIntfAnno);
3307 } else if (!s.isInterface() || (s.flags() & ANNOTATION) != 0) {
3308 log.error(a.pos(), Errors.BadFunctionalIntfAnno1(Fragments.NotAFunctionalIntf(s)));
3309 }
3310 }
3311 }
3312
3313 public void validateTypeAnnotation(JCAnnotation a, Symbol s, boolean isTypeParameter) {
3314 Assert.checkNonNull(a.type);
3315 // we just want to validate that the anotation doesn't have any wrong target
3316 if (s != null) getApplicableTargets(a, s);
3317 validateAnnotationTree(a);
3318
3319 if (a.hasTag(TYPE_ANNOTATION) &&
3320 !a.annotationType.type.isErroneous() &&
3321 !isTypeAnnotation(a, isTypeParameter)) {
3322 log.error(a.pos(), Errors.AnnotationTypeNotApplicableToType(a.type));
3323 }
3324 }
3325
3326 /**
3327 * Validate the proposed container 'repeatable' on the
3328 * annotation type symbol 's'. Report errors at position
3329 * 'pos'.
3330 *
3331 * @param s The (annotation)type declaration annotated with a @Repeatable
3332 * @param repeatable the @Repeatable on 's'
3333 * @param pos where to report errors
3334 */
3335 public void validateRepeatable(TypeSymbol s, Attribute.Compound repeatable, DiagnosticPosition pos) {
3336 Assert.check(types.isSameType(repeatable.type, syms.repeatableType));
3337
3338 Type t = null;
3339 List<Pair<MethodSymbol,Attribute>> l = repeatable.values;
3340 if (!l.isEmpty()) {
3341 Assert.check(l.head.fst.name == names.value);
3342 if (l.head.snd instanceof Attribute.Class) {
3343 t = ((Attribute.Class)l.head.snd).getValue();
3344 }
3345 }
3346
3347 if (t == null) {
3348 // errors should already have been reported during Annotate
3349 return;
3350 }
3351
3352 validateValue(t.tsym, s, pos);
3353 validateRetention(t.tsym, s, pos);
3354 validateDocumented(t.tsym, s, pos);
3355 validateInherited(t.tsym, s, pos);
3356 validateTarget(t.tsym, s, pos);
3357 validateDefault(t.tsym, pos);
3358 }
3359
3360 private void validateValue(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3361 Symbol sym = container.members().findFirst(names.value);
3362 if (sym != null && sym.kind == MTH) {
3363 MethodSymbol m = (MethodSymbol) sym;
3364 Type ret = m.getReturnType();
3365 if (!(ret.hasTag(ARRAY) && types.isSameType(((ArrayType)ret).elemtype, contained.type))) {
3366 log.error(pos,
3367 Errors.InvalidRepeatableAnnotationValueReturn(container,
3368 ret,
3369 types.makeArrayType(contained.type)));
3370 }
3371 } else {
3372 log.error(pos, Errors.InvalidRepeatableAnnotationNoValue(container));
3373 }
3374 }
3375
3376 private void validateRetention(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3377 Attribute.RetentionPolicy containerRetention = types.getRetention(container);
3378 Attribute.RetentionPolicy containedRetention = types.getRetention(contained);
3379
3380 boolean error = false;
3381 switch (containedRetention) {
3382 case RUNTIME:
3383 if (containerRetention != Attribute.RetentionPolicy.RUNTIME) {
3384 error = true;
3385 }
3386 break;
3387 case CLASS:
3388 if (containerRetention == Attribute.RetentionPolicy.SOURCE) {
3389 error = true;
3390 }
3391 }
3392 if (error ) {
3393 log.error(pos,
3394 Errors.InvalidRepeatableAnnotationRetention(container,
3395 containerRetention.name(),
3396 contained,
3397 containedRetention.name()));
3398 }
3399 }
3400
3401 private void validateDocumented(Symbol container, Symbol contained, DiagnosticPosition pos) {
3402 if (contained.attribute(syms.documentedType.tsym) != null) {
3403 if (container.attribute(syms.documentedType.tsym) == null) {
3404 log.error(pos, Errors.InvalidRepeatableAnnotationNotDocumented(container, contained));
3405 }
3406 }
3407 }
3408
3409 private void validateInherited(Symbol container, Symbol contained, DiagnosticPosition pos) {
3410 if (contained.attribute(syms.inheritedType.tsym) != null) {
3411 if (container.attribute(syms.inheritedType.tsym) == null) {
3412 log.error(pos, Errors.InvalidRepeatableAnnotationNotInherited(container, contained));
3413 }
3414 }
3415 }
3416
3417 private void validateTarget(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3418 // The set of targets the container is applicable to must be a subset
3419 // (with respect to annotation target semantics) of the set of targets
3420 // the contained is applicable to. The target sets may be implicit or
3421 // explicit.
3422
3423 Set<Name> containerTargets;
3424 Attribute.Array containerTarget = getAttributeTargetAttribute(container);
3425 if (containerTarget == null) {
3426 containerTargets = getDefaultTargetSet();
3427 } else {
3428 containerTargets = new HashSet<>();
3429 for (Attribute app : containerTarget.values) {
3430 if (!(app instanceof Attribute.Enum attributeEnum)) {
3431 continue; // recovery
3432 }
3433 containerTargets.add(attributeEnum.value.name);
3434 }
3435 }
3436
3437 Set<Name> containedTargets;
3438 Attribute.Array containedTarget = getAttributeTargetAttribute(contained);
3439 if (containedTarget == null) {
3440 containedTargets = getDefaultTargetSet();
3441 } else {
3442 containedTargets = new HashSet<>();
3443 for (Attribute app : containedTarget.values) {
3444 if (!(app instanceof Attribute.Enum attributeEnum)) {
3445 continue; // recovery
3446 }
3447 containedTargets.add(attributeEnum.value.name);
3448 }
3449 }
3450
3451 if (!isTargetSubsetOf(containerTargets, containedTargets)) {
3452 log.error(pos, Errors.InvalidRepeatableAnnotationIncompatibleTarget(container, contained));
3453 }
3454 }
3455
3456 /* get a set of names for the default target */
3457 private Set<Name> getDefaultTargetSet() {
3458 if (defaultTargets == null) {
3459 defaultTargets = Set.of(defaultTargetMetaInfo());
3460 }
3461
3462 return defaultTargets;
3463 }
3464 private Set<Name> defaultTargets;
3465
3466
3467 /** Checks that s is a subset of t, with respect to ElementType
3468 * semantics, specifically {ANNOTATION_TYPE} is a subset of {TYPE},
3469 * and {TYPE_USE} covers the set {ANNOTATION_TYPE, TYPE, TYPE_USE,
3470 * TYPE_PARAMETER}.
3471 */
3472 private boolean isTargetSubsetOf(Set<Name> s, Set<Name> t) {
3473 // Check that all elements in s are present in t
3474 for (Name n2 : s) {
3475 boolean currentElementOk = false;
3476 for (Name n1 : t) {
3477 if (n1 == n2) {
3478 currentElementOk = true;
3479 break;
3480 } else if (n1 == names.TYPE && n2 == names.ANNOTATION_TYPE) {
3481 currentElementOk = true;
3482 break;
3483 } else if (n1 == names.TYPE_USE &&
3484 (n2 == names.TYPE ||
3485 n2 == names.ANNOTATION_TYPE ||
3486 n2 == names.TYPE_PARAMETER)) {
3487 currentElementOk = true;
3488 break;
3489 }
3490 }
3491 if (!currentElementOk)
3492 return false;
3493 }
3494 return true;
3495 }
3496
3497 private void validateDefault(Symbol container, DiagnosticPosition pos) {
3498 // validate that all other elements of containing type has defaults
3499 Scope scope = container.members();
3500 for(Symbol elm : scope.getSymbols()) {
3501 if (elm.name != names.value &&
3502 elm.kind == MTH &&
3503 ((MethodSymbol)elm).defaultValue == null) {
3504 log.error(pos,
3505 Errors.InvalidRepeatableAnnotationElemNondefault(container, elm));
3506 }
3507 }
3508 }
3509
3510 /** Is s a method symbol that overrides a method in a superclass? */
3511 boolean isOverrider(Symbol s) {
3512 if (s.kind != MTH || s.isStatic())
3513 return false;
3514 MethodSymbol m = (MethodSymbol)s;
3515 TypeSymbol owner = (TypeSymbol)m.owner;
3516 for (Type sup : types.closure(owner.type)) {
3517 if (sup == owner.type)
3518 continue; // skip "this"
3519 Scope scope = sup.tsym.members();
3520 for (Symbol sym : scope.getSymbolsByName(m.name)) {
3521 if (!sym.isStatic() && m.overrides(sym, owner, types, true))
3522 return true;
3523 }
3524 }
3525 return false;
3526 }
3527
3528 /** Is the annotation applicable to types? */
3529 protected boolean isTypeAnnotation(JCAnnotation a, boolean isTypeParameter) {
3530 List<Attribute> targets = typeAnnotations.annotationTargets(a.annotationType.type.tsym);
3531 return (targets == null) ?
3532 (Feature.NO_TARGET_ANNOTATION_APPLICABILITY.allowedInSource(source) && isTypeParameter) :
3533 targets.stream()
3534 .anyMatch(attr -> isTypeAnnotation(attr, isTypeParameter));
3535 }
3536 //where
3537 boolean isTypeAnnotation(Attribute a, boolean isTypeParameter) {
3538 Attribute.Enum e = (Attribute.Enum)a;
3539 return (e.value.name == names.TYPE_USE ||
3540 (isTypeParameter && e.value.name == names.TYPE_PARAMETER));
3541 }
3542
3543 /** Is the annotation applicable to the symbol? */
3544 Name[] getTargetNames(JCAnnotation a) {
3545 return getTargetNames(a.annotationType.type.tsym);
3546 }
3547
3548 public Name[] getTargetNames(TypeSymbol annoSym) {
3549 Attribute.Array arr = getAttributeTargetAttribute(annoSym);
3550 Name[] targets;
3551 if (arr == null) {
3552 targets = defaultTargetMetaInfo();
3553 } else {
3554 // TODO: can we optimize this?
3555 targets = new Name[arr.values.length];
3556 for (int i=0; i<arr.values.length; ++i) {
3557 Attribute app = arr.values[i];
3558 if (!(app instanceof Attribute.Enum attributeEnum)) {
3559 return new Name[0];
3560 }
3561 targets[i] = attributeEnum.value.name;
3562 }
3563 }
3564 return targets;
3565 }
3566
3567 boolean annotationApplicable(JCAnnotation a, Symbol s) {
3568 Optional<Set<Name>> targets = getApplicableTargets(a, s);
3569 /* the optional could be empty if the annotation is unknown in that case
3570 * we return that it is applicable and if it is erroneous that should imply
3571 * an error at the declaration site
3572 */
3573 return targets.isEmpty() || targets.isPresent() && !targets.get().isEmpty();
3574 }
3575
3576 Optional<Set<Name>> getApplicableTargets(JCAnnotation a, Symbol s) {
3577 Attribute.Array arr = getAttributeTargetAttribute(a.annotationType.type.tsym);
3578 Name[] targets;
3579 Set<Name> applicableTargets = new HashSet<>();
3580
3581 if (arr == null) {
3582 targets = defaultTargetMetaInfo();
3583 } else {
3584 // TODO: can we optimize this?
3585 targets = new Name[arr.values.length];
3586 for (int i=0; i<arr.values.length; ++i) {
3587 Attribute app = arr.values[i];
3588 if (!(app instanceof Attribute.Enum attributeEnum)) {
3589 // recovery
3590 return Optional.empty();
3591 }
3592 targets[i] = attributeEnum.value.name;
3593 }
3594 }
3595 for (Name target : targets) {
3596 if (target == names.TYPE) {
3597 if (s.kind == TYP)
3598 applicableTargets.add(names.TYPE);
3599 } else if (target == names.FIELD) {
3600 if (s.kind == VAR && s.owner.kind != MTH)
3601 applicableTargets.add(names.FIELD);
3602 } else if (target == names.RECORD_COMPONENT) {
3603 if (s.getKind() == ElementKind.RECORD_COMPONENT) {
3604 applicableTargets.add(names.RECORD_COMPONENT);
3605 }
3606 } else if (target == names.METHOD) {
3607 if (s.kind == MTH && !s.isConstructor())
3608 applicableTargets.add(names.METHOD);
3609 } else if (target == names.PARAMETER) {
3610 if (s.kind == VAR &&
3611 (s.owner.kind == MTH && (s.flags() & PARAMETER) != 0)) {
3612 applicableTargets.add(names.PARAMETER);
3613 }
3614 } else if (target == names.CONSTRUCTOR) {
3615 if (s.kind == MTH && s.isConstructor())
3616 applicableTargets.add(names.CONSTRUCTOR);
3617 } else if (target == names.LOCAL_VARIABLE) {
3618 if (s.kind == VAR && s.owner.kind == MTH &&
3619 (s.flags() & PARAMETER) == 0) {
3620 applicableTargets.add(names.LOCAL_VARIABLE);
3621 }
3622 } else if (target == names.ANNOTATION_TYPE) {
3623 if (s.kind == TYP && (s.flags() & ANNOTATION) != 0) {
3624 applicableTargets.add(names.ANNOTATION_TYPE);
3625 }
3626 } else if (target == names.PACKAGE) {
3627 if (s.kind == PCK)
3628 applicableTargets.add(names.PACKAGE);
3629 } else if (target == names.TYPE_USE) {
3630 if (s.kind == VAR && s.owner.kind == MTH && s.type.hasTag(NONE)) {
3631 //cannot type annotate implicitly typed locals
3632 continue;
3633 } else if (s.kind == TYP || s.kind == VAR ||
3634 (s.kind == MTH && !s.isConstructor() &&
3635 !s.type.getReturnType().hasTag(VOID)) ||
3636 (s.kind == MTH && s.isConstructor())) {
3637 applicableTargets.add(names.TYPE_USE);
3638 }
3639 } else if (target == names.TYPE_PARAMETER) {
3640 if (s.kind == TYP && s.type.hasTag(TYPEVAR))
3641 applicableTargets.add(names.TYPE_PARAMETER);
3642 } else if (target == names.MODULE) {
3643 if (s.kind == MDL)
3644 applicableTargets.add(names.MODULE);
3645 } else {
3646 log.error(a, Errors.AnnotationUnrecognizedAttributeName(a.type, target));
3647 return Optional.empty(); // Unknown ElementType
3648 }
3649 }
3650 return Optional.of(applicableTargets);
3651 }
3652
3653 Attribute.Array getAttributeTargetAttribute(TypeSymbol s) {
3654 Attribute.Compound atTarget = s.getAnnotationTypeMetadata().getTarget();
3655 if (atTarget == null) return null; // ok, is applicable
3656 Attribute atValue = atTarget.member(names.value);
3657 return (atValue instanceof Attribute.Array attributeArray) ? attributeArray : null;
3658 }
3659
3660 private Name[] dfltTargetMeta;
3661 private Name[] defaultTargetMetaInfo() {
3662 if (dfltTargetMeta == null) {
3663 ArrayList<Name> defaultTargets = new ArrayList<>();
3664 defaultTargets.add(names.PACKAGE);
3665 defaultTargets.add(names.TYPE);
3666 defaultTargets.add(names.FIELD);
3667 defaultTargets.add(names.METHOD);
3668 defaultTargets.add(names.CONSTRUCTOR);
3669 defaultTargets.add(names.ANNOTATION_TYPE);
3670 defaultTargets.add(names.LOCAL_VARIABLE);
3671 defaultTargets.add(names.PARAMETER);
3672 if (allowRecords) {
3673 defaultTargets.add(names.RECORD_COMPONENT);
3674 }
3675 if (allowModules) {
3676 defaultTargets.add(names.MODULE);
3677 }
3678 dfltTargetMeta = defaultTargets.toArray(new Name[0]);
3679 }
3680 return dfltTargetMeta;
3681 }
3682
3683 /** Check an annotation value.
3684 *
3685 * @param a The annotation tree to check
3686 * @return true if this annotation tree is valid, otherwise false
3687 */
3688 public boolean validateAnnotationDeferErrors(JCAnnotation a) {
3689 boolean res = false;
3690 final Log.DiagnosticHandler diagHandler = log.new DiscardDiagnosticHandler();
3691 try {
3692 res = validateAnnotation(a);
3693 } finally {
3694 log.popDiagnosticHandler(diagHandler);
3695 }
3696 return res;
3697 }
3698
3699 private boolean validateAnnotation(JCAnnotation a) {
3700 boolean isValid = true;
3701 AnnotationTypeMetadata metadata = a.annotationType.type.tsym.getAnnotationTypeMetadata();
3702
3703 // collect an inventory of the annotation elements
3704 Set<MethodSymbol> elements = metadata.getAnnotationElements();
3705
3706 // remove the ones that are assigned values
3707 for (JCTree arg : a.args) {
3708 if (!arg.hasTag(ASSIGN)) continue; // recovery
3709 JCAssign assign = (JCAssign)arg;
3710 Symbol m = TreeInfo.symbol(assign.lhs);
3711 if (m == null || m.type.isErroneous()) continue;
3712 if (!elements.remove(m)) {
3713 isValid = false;
3714 log.error(assign.lhs.pos(),
3715 Errors.DuplicateAnnotationMemberValue(m.name, a.type));
3716 }
3717 }
3718
3719 // all the remaining ones better have default values
3720 List<Name> missingDefaults = List.nil();
3721 Set<MethodSymbol> membersWithDefault = metadata.getAnnotationElementsWithDefault();
3722 for (MethodSymbol m : elements) {
3723 if (m.type.isErroneous())
3724 continue;
3725
3726 if (!membersWithDefault.contains(m))
3727 missingDefaults = missingDefaults.append(m.name);
3728 }
3729 missingDefaults = missingDefaults.reverse();
3730 if (missingDefaults.nonEmpty()) {
3731 isValid = false;
3732 Error errorKey = (missingDefaults.size() > 1)
3733 ? Errors.AnnotationMissingDefaultValue1(a.type, missingDefaults)
3734 : Errors.AnnotationMissingDefaultValue(a.type, missingDefaults);
3735 log.error(a.pos(), errorKey);
3736 }
3737
3738 return isValid && validateTargetAnnotationValue(a);
3739 }
3740
3741 /* Validate the special java.lang.annotation.Target annotation */
3742 boolean validateTargetAnnotationValue(JCAnnotation a) {
3743 // special case: java.lang.annotation.Target must not have
3744 // repeated values in its value member
3745 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
3746 a.args.tail == null)
3747 return true;
3748
3749 boolean isValid = true;
3750 if (!a.args.head.hasTag(ASSIGN)) return false; // error recovery
3751 JCAssign assign = (JCAssign) a.args.head;
3752 Symbol m = TreeInfo.symbol(assign.lhs);
3753 if (m.name != names.value) return false;
3754 JCTree rhs = assign.rhs;
3755 if (!rhs.hasTag(NEWARRAY)) return false;
3756 JCNewArray na = (JCNewArray) rhs;
3757 Set<Symbol> targets = new HashSet<>();
3758 for (JCTree elem : na.elems) {
3759 if (!targets.add(TreeInfo.symbol(elem))) {
3760 isValid = false;
3761 log.error(elem.pos(), Errors.RepeatedAnnotationTarget);
3762 }
3763 }
3764 return isValid;
3765 }
3766
3767 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
3768 if (lint.isEnabled(LintCategory.DEP_ANN) && s.isDeprecatableViaAnnotation() &&
3769 (s.flags() & DEPRECATED) != 0 &&
3770 !syms.deprecatedType.isErroneous() &&
3771 s.attribute(syms.deprecatedType.tsym) == null) {
3772 log.warning(pos, LintWarnings.MissingDeprecatedAnnotation);
3773 }
3774 // Note: @Deprecated has no effect on local variables, parameters and package decls.
3775 if (lint.isEnabled(LintCategory.DEPRECATION) && !s.isDeprecatableViaAnnotation()) {
3776 if (!syms.deprecatedType.isErroneous() && s.attribute(syms.deprecatedType.tsym) != null) {
3777 log.warning(pos,
3778 LintWarnings.DeprecatedAnnotationHasNoEffect(Kinds.kindName(s)));
3779 }
3780 }
3781 }
3782
3783 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
3784 checkDeprecated(() -> pos, other, s);
3785 }
3786
3787 void checkDeprecated(Supplier<DiagnosticPosition> pos, final Symbol other, final Symbol s) {
3788 if (!importSuppression
3789 && (s.isDeprecatedForRemoval() || s.isDeprecated() && !other.isDeprecated())
3790 && (s.outermostClass() != other.outermostClass() || s.outermostClass() == null)
3791 && s.kind != Kind.PCK) {
3792 deferredLintHandler.report(_l -> warnDeprecated(pos.get(), s));
3793 }
3794 }
3795
3796 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
3797 if ((s.flags() & PROPRIETARY) != 0) {
3798 deferredLintHandler.report(_l -> {
3799 log.mandatoryWarning(pos, Warnings.SunProprietary(s));
3800 });
3801 }
3802 }
3803
3804 void checkProfile(final DiagnosticPosition pos, final Symbol s) {
3805 if (profile != Profile.DEFAULT && (s.flags() & NOT_IN_PROFILE) != 0) {
3806 log.error(pos, Errors.NotInProfile(s, profile));
3807 }
3808 }
3809
3810 void checkPreview(DiagnosticPosition pos, Symbol other, Symbol s) {
3811 checkPreview(pos, other, Type.noType, s);
3812 }
3813
3814 void checkPreview(DiagnosticPosition pos, Symbol other, Type site, Symbol s) {
3815 boolean sIsPreview;
3816 Symbol previewSymbol;
3817 if ((s.flags() & PREVIEW_API) != 0) {
3818 sIsPreview = true;
3819 previewSymbol= s;
3820 } else if ((s.kind == Kind.MTH || s.kind == Kind.VAR) &&
3821 site.tsym != null &&
3822 (site.tsym.flags() & PREVIEW_API) == 0 &&
3823 (s.owner.flags() & PREVIEW_API) != 0) {
3824 //calling a method, or using a field, whose owner is a preview, but
3825 //using a site that is not a preview. Also produce an error or warning:
3826 sIsPreview = true;
3827 previewSymbol = s.owner;
3828 } else {
3829 sIsPreview = false;
3830 previewSymbol = null;
3831 }
3832 if (sIsPreview && !preview.participatesInPreview(syms, other, s) && !disablePreviewCheck) {
3833 if ((previewSymbol.flags() & PREVIEW_REFLECTIVE) == 0) {
3834 if (!preview.isEnabled()) {
3835 log.error(pos, Errors.IsPreview(s));
3836 } else {
3837 preview.markUsesPreview(pos);
3838 warnPreviewAPI(pos, LintWarnings.IsPreview(s));
3839 }
3840 } else {
3841 warnPreviewAPI(pos, LintWarnings.IsPreviewReflective(s));
3842 }
3843 }
3844 if (preview.declaredUsingPreviewFeature(s)) {
3845 if (preview.isEnabled()) {
3846 //for preview disabled do presumably so not need to do anything?
3847 //If "s" is compiled from source, then there was an error for it already;
3848 //if "s" is from classfile, there already was an error for the classfile.
3849 preview.markUsesPreview(pos);
3850 warnPreviewAPI(pos, LintWarnings.DeclaredUsingPreview(kindName(s), s));
3851 }
3852 }
3853 }
3854
3855 void checkRestricted(DiagnosticPosition pos, Symbol s) {
3856 if (s.kind == MTH && (s.flags() & RESTRICTED) != 0) {
3857 deferredLintHandler.report(_l -> warnRestrictedAPI(pos, s));
3858 }
3859 }
3860
3861 /* *************************************************************************
3862 * Check for recursive annotation elements.
3863 **************************************************************************/
3864
3865 /** Check for cycles in the graph of annotation elements.
3866 */
3867 void checkNonCyclicElements(JCClassDecl tree) {
3868 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
3869 Assert.check((tree.sym.flags_field & LOCKED) == 0);
3870 try {
3871 tree.sym.flags_field |= LOCKED;
3872 for (JCTree def : tree.defs) {
3873 if (!def.hasTag(METHODDEF)) continue;
3874 JCMethodDecl meth = (JCMethodDecl)def;
3875 checkAnnotationResType(meth.pos(), meth.restype.type);
3876 }
3877 } finally {
3878 tree.sym.flags_field &= ~LOCKED;
3879 tree.sym.flags_field |= ACYCLIC_ANN;
3880 }
3881 }
3882
3883 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
3884 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
3885 return;
3886 if ((tsym.flags_field & LOCKED) != 0) {
3887 log.error(pos, Errors.CyclicAnnotationElement(tsym));
3888 return;
3889 }
3890 try {
3891 tsym.flags_field |= LOCKED;
3892 for (Symbol s : tsym.members().getSymbols(NON_RECURSIVE)) {
3893 if (s.kind != MTH)
3894 continue;
3895 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
3896 }
3897 } finally {
3898 tsym.flags_field &= ~LOCKED;
3899 tsym.flags_field |= ACYCLIC_ANN;
3900 }
3901 }
3902
3903 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
3904 switch (type.getTag()) {
3905 case CLASS:
3906 if ((type.tsym.flags() & ANNOTATION) != 0)
3907 checkNonCyclicElementsInternal(pos, type.tsym);
3908 break;
3909 case ARRAY:
3910 checkAnnotationResType(pos, types.elemtype(type));
3911 break;
3912 default:
3913 break; // int etc
3914 }
3915 }
3916
3917 /* *************************************************************************
3918 * Check for cycles in the constructor call graph.
3919 **************************************************************************/
3920
3921 /** Check for cycles in the graph of constructors calling other
3922 * constructors.
3923 */
3924 void checkCyclicConstructors(JCClassDecl tree) {
3925 // use LinkedHashMap so we generate errors deterministically
3926 Map<Symbol,Symbol> callMap = new LinkedHashMap<>();
3927
3928 // enter each constructor this-call into the map
3929 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3930 if (!TreeInfo.isConstructor(l.head))
3931 continue;
3932 JCMethodDecl meth = (JCMethodDecl)l.head;
3933 JCMethodInvocation app = TreeInfo.findConstructorCall(meth);
3934 if (app != null && TreeInfo.name(app.meth) == names._this) {
3935 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
3936 } else {
3937 meth.sym.flags_field |= ACYCLIC;
3938 }
3939 }
3940
3941 // Check for cycles in the map
3942 Symbol[] ctors = new Symbol[0];
3943 ctors = callMap.keySet().toArray(ctors);
3944 for (Symbol caller : ctors) {
3945 checkCyclicConstructor(tree, caller, callMap);
3946 }
3947 }
3948
3949 /** Look in the map to see if the given constructor is part of a
3950 * call cycle.
3951 */
3952 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
3953 Map<Symbol,Symbol> callMap) {
3954 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
3955 if ((ctor.flags_field & LOCKED) != 0) {
3956 log.error(TreeInfo.diagnosticPositionFor(ctor, tree, false, t -> t.hasTag(IDENT)),
3957 Errors.RecursiveCtorInvocation);
3958 } else {
3959 ctor.flags_field |= LOCKED;
3960 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
3961 ctor.flags_field &= ~LOCKED;
3962 }
3963 ctor.flags_field |= ACYCLIC;
3964 }
3965 }
3966
3967 /* *************************************************************************
3968 * Verify the proper placement of super()/this() calls.
3969 *
3970 * - super()/this() may only appear in constructors
3971 * - There must be at most one super()/this() call per constructor
3972 * - The super()/this() call, if any, must be a top-level statement in the
3973 * constructor, i.e., not nested inside any other statement or block
3974 * - There must be no return statements prior to the super()/this() call
3975 **************************************************************************/
3976
3977 void checkSuperInitCalls(JCClassDecl tree) {
3978 new SuperThisChecker().check(tree);
3979 }
3980
3981 private class SuperThisChecker extends TreeScanner {
3982
3983 // Match this scan stack: 1=JCMethodDecl, 2=JCExpressionStatement, 3=JCMethodInvocation
3984 private static final int MATCH_SCAN_DEPTH = 3;
3985
3986 private boolean constructor; // is this method a constructor?
3987 private boolean firstStatement; // at the first statement in method?
3988 private JCReturn earlyReturn; // first return prior to the super()/init(), if any
3989 private Name initCall; // whichever of "super" or "init" we've seen already
3990 private int scanDepth; // current scan recursion depth in method body
3991
3992 public void check(JCClassDecl classDef) {
3993 scan(classDef.defs);
3994 }
3995
3996 @Override
3997 public void visitMethodDef(JCMethodDecl tree) {
3998 Assert.check(!constructor);
3999 Assert.check(earlyReturn == null);
4000 Assert.check(initCall == null);
4001 Assert.check(scanDepth == 1);
4002
4003 // Initialize state for this method
4004 constructor = TreeInfo.isConstructor(tree);
4005 try {
4006
4007 // Scan method body
4008 if (tree.body != null) {
4009 firstStatement = true;
4010 for (List<JCStatement> l = tree.body.stats; l.nonEmpty(); l = l.tail) {
4011 scan(l.head);
4012 firstStatement = false;
4013 }
4014 }
4015
4016 // Verify no 'return' seen prior to an explicit super()/this() call
4017 if (constructor && earlyReturn != null && initCall != null)
4018 log.error(earlyReturn.pos(), Errors.ReturnBeforeSuperclassInitialized);
4019 } finally {
4020 firstStatement = false;
4021 constructor = false;
4022 earlyReturn = null;
4023 initCall = null;
4024 }
4025 }
4026
4027 @Override
4028 public void scan(JCTree tree) {
4029 scanDepth++;
4030 try {
4031 super.scan(tree);
4032 } finally {
4033 scanDepth--;
4034 }
4035 }
4036
4037 @Override
4038 public void visitApply(JCMethodInvocation apply) {
4039 do {
4040
4041 // Is this a super() or this() call?
4042 Name methodName = TreeInfo.name(apply.meth);
4043 if (methodName != names._super && methodName != names._this)
4044 break;
4045
4046 // super()/this() calls must only appear in a constructor
4047 if (!constructor) {
4048 log.error(apply.pos(), Errors.CallMustOnlyAppearInCtor);
4049 break;
4050 }
4051
4052 // super()/this() calls must be a top level statement
4053 if (scanDepth != MATCH_SCAN_DEPTH) {
4054 log.error(apply.pos(), Errors.CtorCallsNotAllowedHere);
4055 break;
4056 }
4057
4058 // super()/this() calls must not appear more than once
4059 if (initCall != null) {
4060 log.error(apply.pos(), Errors.RedundantSuperclassInit);
4061 break;
4062 }
4063
4064 // If super()/this() isn't first, require flexible constructors feature
4065 if (!firstStatement)
4066 preview.checkSourceLevel(apply.pos(), Feature.FLEXIBLE_CONSTRUCTORS);
4067
4068 // We found a legitimate super()/this() call; remember it
4069 initCall = methodName;
4070 } while (false);
4071
4072 // Proceed
4073 super.visitApply(apply);
4074 }
4075
4076 @Override
4077 public void visitReturn(JCReturn tree) {
4078 if (constructor && initCall == null && earlyReturn == null)
4079 earlyReturn = tree; // we have seen a return but not (yet) a super()/this()
4080 super.visitReturn(tree);
4081 }
4082
4083 @Override
4084 public void visitClassDef(JCClassDecl tree) {
4085 // don't descend any further
4086 }
4087
4088 @Override
4089 public void visitLambda(JCLambda tree) {
4090 final boolean constructorPrev = constructor;
4091 final boolean firstStatementPrev = firstStatement;
4092 final JCReturn earlyReturnPrev = earlyReturn;
4093 final Name initCallPrev = initCall;
4094 final int scanDepthPrev = scanDepth;
4095 constructor = false;
4096 firstStatement = false;
4097 earlyReturn = null;
4098 initCall = null;
4099 scanDepth = 0;
4100 try {
4101 super.visitLambda(tree);
4102 } finally {
4103 constructor = constructorPrev;
4104 firstStatement = firstStatementPrev;
4105 earlyReturn = earlyReturnPrev;
4106 initCall = initCallPrev;
4107 scanDepth = scanDepthPrev;
4108 }
4109 }
4110 }
4111
4112 /* *************************************************************************
4113 * Miscellaneous
4114 **************************************************************************/
4115
4116 /**
4117 * Check for division by integer constant zero
4118 * @param pos Position for error reporting.
4119 * @param operator The operator for the expression
4120 * @param operand The right hand operand for the expression
4121 */
4122 void checkDivZero(final DiagnosticPosition pos, Symbol operator, Type operand) {
4123 if (operand.constValue() != null
4124 && operand.getTag().isSubRangeOf(LONG)
4125 && ((Number) (operand.constValue())).longValue() == 0) {
4126 int opc = ((OperatorSymbol)operator).opcode;
4127 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
4128 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
4129 deferredLintHandler.report(_ -> lint.logIfEnabled(pos, LintWarnings.DivZero));
4130 }
4131 }
4132 }
4133
4134 /**
4135 * Check for possible loss of precission
4136 * @param pos Position for error reporting.
4137 * @param found The computed type of the tree
4138 * @param req The computed type of the tree
4139 */
4140 void checkLossOfPrecision(final DiagnosticPosition pos, Type found, Type req) {
4141 if (found.isNumeric() && req.isNumeric() && !types.isAssignable(found, req)) {
4142 deferredLintHandler.report(_ ->
4143 lint.logIfEnabled(pos, LintWarnings.PossibleLossOfPrecision(found, req)));
4144 }
4145 }
4146
4147 /**
4148 * Check for empty statements after if
4149 */
4150 void checkEmptyIf(JCIf tree) {
4151 if (tree.thenpart.hasTag(SKIP) && tree.elsepart == null) {
4152 lint.logIfEnabled(tree.thenpart.pos(), LintWarnings.EmptyIf);
4153 }
4154 }
4155
4156 /** Check that symbol is unique in given scope.
4157 * @param pos Position for error reporting.
4158 * @param sym The symbol.
4159 * @param s The scope.
4160 */
4161 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
4162 if (sym.type.isErroneous())
4163 return true;
4164 if (sym.owner.name == names.any) return false;
4165 for (Symbol byName : s.getSymbolsByName(sym.name, NON_RECURSIVE)) {
4166 if (sym != byName &&
4167 (byName.flags() & CLASH) == 0 &&
4168 sym.kind == byName.kind &&
4169 sym.name != names.error &&
4170 (sym.kind != MTH ||
4171 types.hasSameArgs(sym.type, byName.type) ||
4172 types.hasSameArgs(types.erasure(sym.type), types.erasure(byName.type)))) {
4173 if ((sym.flags() & VARARGS) != (byName.flags() & VARARGS)) {
4174 sym.flags_field |= CLASH;
4175 varargsDuplicateError(pos, sym, byName);
4176 return true;
4177 } else if (sym.kind == MTH && !types.hasSameArgs(sym.type, byName.type, false)) {
4178 duplicateErasureError(pos, sym, byName);
4179 sym.flags_field |= CLASH;
4180 return true;
4181 } else if ((sym.flags() & MATCH_BINDING) != 0 &&
4182 (byName.flags() & MATCH_BINDING) != 0 &&
4183 (byName.flags() & MATCH_BINDING_TO_OUTER) == 0) {
4184 if (!sym.type.isErroneous()) {
4185 log.error(pos, Errors.MatchBindingExists);
4186 sym.flags_field |= CLASH;
4187 }
4188 return false;
4189 } else {
4190 duplicateError(pos, byName);
4191 return false;
4192 }
4193 }
4194 }
4195 return true;
4196 }
4197
4198 /** Report duplicate declaration error.
4199 */
4200 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
4201 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
4202 log.error(pos, Errors.NameClashSameErasure(sym1, sym2));
4203 }
4204 }
4205
4206 /**Check that types imported through the ordinary imports don't clash with types imported
4207 * by other (static or ordinary) imports. Note that two static imports may import two clashing
4208 * types without an error on the imports.
4209 * @param toplevel The toplevel tree for which the test should be performed.
4210 */
4211 void checkImportsUnique(JCCompilationUnit toplevel) {
4212 WriteableScope ordinallyImportedSoFar = WriteableScope.create(toplevel.packge);
4213 WriteableScope staticallyImportedSoFar = WriteableScope.create(toplevel.packge);
4214 WriteableScope topLevelScope = toplevel.toplevelScope;
4215
4216 for (JCTree def : toplevel.defs) {
4217 if (!def.hasTag(IMPORT))
4218 continue;
4219
4220 JCImport imp = (JCImport) def;
4221
4222 if (imp.importScope == null)
4223 continue;
4224
4225 for (Symbol sym : imp.importScope.getSymbols(sym -> sym.kind == TYP)) {
4226 if (imp.isStatic()) {
4227 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, true);
4228 staticallyImportedSoFar.enter(sym);
4229 } else {
4230 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, false);
4231 ordinallyImportedSoFar.enter(sym);
4232 }
4233 }
4234
4235 imp.importScope = null;
4236 }
4237 }
4238
4239 /** Check that single-type import is not already imported or top-level defined,
4240 * but make an exception for two single-type imports which denote the same type.
4241 * @param pos Position for error reporting.
4242 * @param ordinallyImportedSoFar A Scope containing types imported so far through
4243 * ordinary imports.
4244 * @param staticallyImportedSoFar A Scope containing types imported so far through
4245 * static imports.
4246 * @param topLevelScope The current file's top-level Scope
4247 * @param sym The symbol.
4248 * @param staticImport Whether or not this was a static import
4249 */
4250 private boolean checkUniqueImport(DiagnosticPosition pos, Scope ordinallyImportedSoFar,
4251 Scope staticallyImportedSoFar, Scope topLevelScope,
4252 Symbol sym, boolean staticImport) {
4253 Predicate<Symbol> duplicates = candidate -> candidate != sym && !candidate.type.isErroneous();
4254 Symbol ordinaryClashing = ordinallyImportedSoFar.findFirst(sym.name, duplicates);
4255 Symbol staticClashing = null;
4256 if (ordinaryClashing == null && !staticImport) {
4257 staticClashing = staticallyImportedSoFar.findFirst(sym.name, duplicates);
4258 }
4259 if (ordinaryClashing != null || staticClashing != null) {
4260 if (ordinaryClashing != null)
4261 log.error(pos, Errors.AlreadyDefinedSingleImport(ordinaryClashing));
4262 else
4263 log.error(pos, Errors.AlreadyDefinedStaticSingleImport(staticClashing));
4264 return false;
4265 }
4266 Symbol clashing = topLevelScope.findFirst(sym.name, duplicates);
4267 if (clashing != null) {
4268 log.error(pos, Errors.AlreadyDefinedThisUnit(clashing));
4269 return false;
4270 }
4271 return true;
4272 }
4273
4274 /** Check that a qualified name is in canonical form (for import decls).
4275 */
4276 public void checkCanonical(JCTree tree) {
4277 if (!isCanonical(tree))
4278 log.error(tree.pos(),
4279 Errors.ImportRequiresCanonical(TreeInfo.symbol(tree)));
4280 }
4281 // where
4282 private boolean isCanonical(JCTree tree) {
4283 while (tree.hasTag(SELECT)) {
4284 JCFieldAccess s = (JCFieldAccess) tree;
4285 if (s.sym.owner.getQualifiedName() != TreeInfo.symbol(s.selected).getQualifiedName())
4286 return false;
4287 tree = s.selected;
4288 }
4289 return true;
4290 }
4291
4292 /** Check that an auxiliary class is not accessed from any other file than its own.
4293 */
4294 void checkForBadAuxiliaryClassAccess(DiagnosticPosition pos, Env<AttrContext> env, ClassSymbol c) {
4295 if ((c.flags() & AUXILIARY) != 0 &&
4296 rs.isAccessible(env, c) &&
4297 !fileManager.isSameFile(c.sourcefile, env.toplevel.sourcefile))
4298 {
4299 lint.logIfEnabled(pos,
4300 LintWarnings.AuxiliaryClassAccessedFromOutsideOfItsSourceFile(c, c.sourcefile));
4301 }
4302 }
4303
4304 /**
4305 * Check for a default constructor in an exported package.
4306 */
4307 void checkDefaultConstructor(ClassSymbol c, DiagnosticPosition pos) {
4308 if (lint.isEnabled(LintCategory.MISSING_EXPLICIT_CTOR) &&
4309 ((c.flags() & (ENUM | RECORD)) == 0) &&
4310 !c.isAnonymous() &&
4311 ((c.flags() & (PUBLIC | PROTECTED)) != 0) &&
4312 Feature.MODULES.allowedInSource(source)) {
4313 NestingKind nestingKind = c.getNestingKind();
4314 switch (nestingKind) {
4315 case ANONYMOUS,
4316 LOCAL -> {return;}
4317 case TOP_LEVEL -> {;} // No additional checks needed
4318 case MEMBER -> {
4319 // For nested member classes, all the enclosing
4320 // classes must be public or protected.
4321 Symbol owner = c.owner;
4322 while (owner != null && owner.kind == TYP) {
4323 if ((owner.flags() & (PUBLIC | PROTECTED)) == 0)
4324 return;
4325 owner = owner.owner;
4326 }
4327 }
4328 }
4329
4330 // Only check classes in named packages exported by its module
4331 PackageSymbol pkg = c.packge();
4332 if (!pkg.isUnnamed()) {
4333 ModuleSymbol modle = pkg.modle;
4334 for (ExportsDirective exportDir : modle.exports) {
4335 // Report warning only if the containing
4336 // package is unconditionally exported
4337 if (exportDir.packge.equals(pkg)) {
4338 if (exportDir.modules == null || exportDir.modules.isEmpty()) {
4339 // Warning may be suppressed by
4340 // annotations; check again for being
4341 // enabled in the deferred context.
4342 deferredLintHandler.report(_ ->
4343 lint.logIfEnabled(pos, LintWarnings.MissingExplicitCtor(c, pkg, modle)));
4344 } else {
4345 return;
4346 }
4347 }
4348 }
4349 }
4350 }
4351 return;
4352 }
4353
4354 private class ConversionWarner extends Warner {
4355 final String uncheckedKey;
4356 final Type found;
4357 final Type expected;
4358 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
4359 super(pos);
4360 this.uncheckedKey = uncheckedKey;
4361 this.found = found;
4362 this.expected = expected;
4363 }
4364
4365 @Override
4366 public void warn(LintCategory lint) {
4367 boolean warned = this.warned;
4368 super.warn(lint);
4369 if (warned) return; // suppress redundant diagnostics
4370 switch (lint) {
4371 case UNCHECKED:
4372 Check.this.warnUnchecked(pos(), LintWarnings.ProbFoundReq(diags.fragment(uncheckedKey), found, expected));
4373 break;
4374 case VARARGS:
4375 if (method != null &&
4376 method.attribute(syms.trustMeType.tsym) != null &&
4377 isTrustMeAllowedOnMethod(method) &&
4378 !types.isReifiable(method.type.getParameterTypes().last())) {
4379 Check.this.lint.logIfEnabled(pos(), LintWarnings.VarargsUnsafeUseVarargsParam(method.params.last()));
4380 }
4381 break;
4382 default:
4383 throw new AssertionError("Unexpected lint: " + lint);
4384 }
4385 }
4386 }
4387
4388 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
4389 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
4390 }
4391
4392 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
4393 return new ConversionWarner(pos, "unchecked.assign", found, expected);
4394 }
4395
4396 public void checkFunctionalInterface(JCClassDecl tree, ClassSymbol cs) {
4397 Compound functionalType = cs.attribute(syms.functionalInterfaceType.tsym);
4398
4399 if (functionalType != null) {
4400 try {
4401 types.findDescriptorSymbol((TypeSymbol)cs);
4402 } catch (Types.FunctionDescriptorLookupError ex) {
4403 DiagnosticPosition pos = tree.pos();
4404 for (JCAnnotation a : tree.getModifiers().annotations) {
4405 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
4406 pos = a.pos();
4407 break;
4408 }
4409 }
4410 log.error(pos, Errors.BadFunctionalIntfAnno1(ex.getDiagnostic()));
4411 }
4412 }
4413 }
4414
4415 public void checkImportsResolvable(final JCCompilationUnit toplevel) {
4416 for (final JCImportBase impBase : toplevel.getImports()) {
4417 if (!(impBase instanceof JCImport imp))
4418 continue;
4419 if (!imp.staticImport || !imp.qualid.hasTag(SELECT))
4420 continue;
4421 final JCFieldAccess select = imp.qualid;
4422 final Symbol origin;
4423 if (select.name == names.asterisk || (origin = TreeInfo.symbol(select.selected)) == null || origin.kind != TYP)
4424 continue;
4425
4426 TypeSymbol site = (TypeSymbol) TreeInfo.symbol(select.selected);
4427 if (!checkTypeContainsImportableElement(site, site, toplevel.packge, select.name, new HashSet<Symbol>())) {
4428 log.error(imp.pos(),
4429 Errors.CantResolveLocation(KindName.STATIC,
4430 select.name,
4431 null,
4432 null,
4433 Fragments.Location(kindName(site),
4434 site,
4435 null)));
4436 }
4437 }
4438 }
4439
4440 // Check that packages imported are in scope (JLS 7.4.3, 6.3, 6.5.3.1, 6.5.3.2)
4441 public void checkImportedPackagesObservable(final JCCompilationUnit toplevel) {
4442 OUTER: for (JCImportBase impBase : toplevel.getImports()) {
4443 if (impBase instanceof JCImport imp && !imp.staticImport &&
4444 TreeInfo.name(imp.qualid) == names.asterisk) {
4445 TypeSymbol tsym = imp.qualid.selected.type.tsym;
4446 if (tsym.kind == PCK && tsym.members().isEmpty() &&
4447 !(Feature.IMPORT_ON_DEMAND_OBSERVABLE_PACKAGES.allowedInSource(source) && tsym.exists())) {
4448 log.error(DiagnosticFlag.RESOLVE_ERROR, imp.qualid.selected.pos(), Errors.DoesntExist(tsym));
4449 }
4450 }
4451 }
4452 }
4453
4454 private boolean checkTypeContainsImportableElement(TypeSymbol tsym, TypeSymbol origin, PackageSymbol packge, Name name, Set<Symbol> processed) {
4455 if (tsym == null || !processed.add(tsym))
4456 return false;
4457
4458 // also search through inherited names
4459 if (checkTypeContainsImportableElement(types.supertype(tsym.type).tsym, origin, packge, name, processed))
4460 return true;
4461
4462 for (Type t : types.interfaces(tsym.type))
4463 if (checkTypeContainsImportableElement(t.tsym, origin, packge, name, processed))
4464 return true;
4465
4466 for (Symbol sym : tsym.members().getSymbolsByName(name)) {
4467 if (sym.isStatic() &&
4468 importAccessible(sym, packge) &&
4469 sym.isMemberOf(origin, types)) {
4470 return true;
4471 }
4472 }
4473
4474 return false;
4475 }
4476
4477 // is the sym accessible everywhere in packge?
4478 public boolean importAccessible(Symbol sym, PackageSymbol packge) {
4479 try {
4480 int flags = (int)(sym.flags() & AccessFlags);
4481 switch (flags) {
4482 default:
4483 case PUBLIC:
4484 return true;
4485 case PRIVATE:
4486 return false;
4487 case 0:
4488 case PROTECTED:
4489 return sym.packge() == packge;
4490 }
4491 } catch (ClassFinder.BadClassFile err) {
4492 throw err;
4493 } catch (CompletionFailure ex) {
4494 return false;
4495 }
4496 }
4497
4498 public void checkLeaksNotAccessible(Env<AttrContext> env, JCClassDecl check) {
4499 JCCompilationUnit toplevel = env.toplevel;
4500
4501 if ( toplevel.modle == syms.unnamedModule
4502 || toplevel.modle == syms.noModule
4503 || (check.sym.flags() & COMPOUND) != 0) {
4504 return ;
4505 }
4506
4507 ExportsDirective currentExport = findExport(toplevel.packge);
4508
4509 if ( currentExport == null //not exported
4510 || currentExport.modules != null) //don't check classes in qualified export
4511 return ;
4512
4513 new TreeScanner() {
4514 Lint lint = env.info.lint;
4515 boolean inSuperType;
4516
4517 @Override
4518 public void visitBlock(JCBlock tree) {
4519 }
4520 @Override
4521 public void visitMethodDef(JCMethodDecl tree) {
4522 if (!isAPISymbol(tree.sym))
4523 return;
4524 Lint prevLint = lint;
4525 try {
4526 lint = lint.augment(tree.sym);
4527 if (lint.isEnabled(LintCategory.EXPORTS)) {
4528 super.visitMethodDef(tree);
4529 }
4530 } finally {
4531 lint = prevLint;
4532 }
4533 }
4534 @Override
4535 public void visitVarDef(JCVariableDecl tree) {
4536 if (!isAPISymbol(tree.sym) && tree.sym.owner.kind != MTH)
4537 return;
4538 Lint prevLint = lint;
4539 try {
4540 lint = lint.augment(tree.sym);
4541 if (lint.isEnabled(LintCategory.EXPORTS)) {
4542 scan(tree.mods);
4543 scan(tree.vartype);
4544 }
4545 } finally {
4546 lint = prevLint;
4547 }
4548 }
4549 @Override
4550 public void visitClassDef(JCClassDecl tree) {
4551 if (tree != check)
4552 return ;
4553
4554 if (!isAPISymbol(tree.sym))
4555 return ;
4556
4557 Lint prevLint = lint;
4558 try {
4559 lint = lint.augment(tree.sym);
4560 if (lint.isEnabled(LintCategory.EXPORTS)) {
4561 scan(tree.mods);
4562 scan(tree.typarams);
4563 try {
4564 inSuperType = true;
4565 scan(tree.extending);
4566 scan(tree.implementing);
4567 } finally {
4568 inSuperType = false;
4569 }
4570 scan(tree.defs);
4571 }
4572 } finally {
4573 lint = prevLint;
4574 }
4575 }
4576 @Override
4577 public void visitTypeApply(JCTypeApply tree) {
4578 scan(tree.clazz);
4579 boolean oldInSuperType = inSuperType;
4580 try {
4581 inSuperType = false;
4582 scan(tree.arguments);
4583 } finally {
4584 inSuperType = oldInSuperType;
4585 }
4586 }
4587 @Override
4588 public void visitIdent(JCIdent tree) {
4589 Symbol sym = TreeInfo.symbol(tree);
4590 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR)) {
4591 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4592 }
4593 }
4594
4595 @Override
4596 public void visitSelect(JCFieldAccess tree) {
4597 Symbol sym = TreeInfo.symbol(tree);
4598 Symbol sitesym = TreeInfo.symbol(tree.selected);
4599 if (sym.kind == TYP && sitesym.kind == PCK) {
4600 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4601 } else {
4602 super.visitSelect(tree);
4603 }
4604 }
4605
4606 @Override
4607 public void visitAnnotation(JCAnnotation tree) {
4608 if (tree.attribute.type.tsym.getAnnotation(java.lang.annotation.Documented.class) != null)
4609 super.visitAnnotation(tree);
4610 }
4611
4612 }.scan(check);
4613 }
4614 //where:
4615 private ExportsDirective findExport(PackageSymbol pack) {
4616 for (ExportsDirective d : pack.modle.exports) {
4617 if (d.packge == pack)
4618 return d;
4619 }
4620
4621 return null;
4622 }
4623 private boolean isAPISymbol(Symbol sym) {
4624 while (sym.kind != PCK) {
4625 if ((sym.flags() & Flags.PUBLIC) == 0 && (sym.flags() & Flags.PROTECTED) == 0) {
4626 return false;
4627 }
4628 sym = sym.owner;
4629 }
4630 return true;
4631 }
4632 private void checkVisible(DiagnosticPosition pos, Symbol what, PackageSymbol inPackage, boolean inSuperType) {
4633 if (!isAPISymbol(what) && !inSuperType) { //package private/private element
4634 log.warning(pos, LintWarnings.LeaksNotAccessible(kindName(what), what, what.packge().modle));
4635 return ;
4636 }
4637
4638 PackageSymbol whatPackage = what.packge();
4639 ExportsDirective whatExport = findExport(whatPackage);
4640 ExportsDirective inExport = findExport(inPackage);
4641
4642 if (whatExport == null) { //package not exported:
4643 log.warning(pos, LintWarnings.LeaksNotAccessibleUnexported(kindName(what), what, what.packge().modle));
4644 return ;
4645 }
4646
4647 if (whatExport.modules != null) {
4648 if (inExport.modules == null || !whatExport.modules.containsAll(inExport.modules)) {
4649 log.warning(pos, LintWarnings.LeaksNotAccessibleUnexportedQualified(kindName(what), what, what.packge().modle));
4650 }
4651 }
4652
4653 if (whatPackage.modle != inPackage.modle && whatPackage.modle != syms.java_base) {
4654 //check that relativeTo.modle requires transitive what.modle, somehow:
4655 List<ModuleSymbol> todo = List.of(inPackage.modle);
4656
4657 while (todo.nonEmpty()) {
4658 ModuleSymbol current = todo.head;
4659 todo = todo.tail;
4660 if (current == whatPackage.modle)
4661 return ; //OK
4662 if ((current.flags() & Flags.AUTOMATIC_MODULE) != 0)
4663 continue; //for automatic modules, don't look into their dependencies
4664 for (RequiresDirective req : current.requires) {
4665 if (req.isTransitive()) {
4666 todo = todo.prepend(req.module);
4667 }
4668 }
4669 }
4670
4671 log.warning(pos, LintWarnings.LeaksNotAccessibleNotRequiredTransitive(kindName(what), what, what.packge().modle));
4672 }
4673 }
4674
4675 void checkModuleExists(final DiagnosticPosition pos, ModuleSymbol msym) {
4676 if (msym.kind != MDL) {
4677 deferredLintHandler.report(_ ->
4678 lint.logIfEnabled(pos, LintWarnings.ModuleNotFound(msym)));
4679 }
4680 }
4681
4682 void checkPackageExistsForOpens(final DiagnosticPosition pos, PackageSymbol packge) {
4683 if (packge.members().isEmpty() &&
4684 ((packge.flags() & Flags.HAS_RESOURCE) == 0)) {
4685 deferredLintHandler.report(_ ->
4686 lint.logIfEnabled(pos, LintWarnings.PackageEmptyOrNotFound(packge)));
4687 }
4688 }
4689
4690 void checkModuleRequires(final DiagnosticPosition pos, final RequiresDirective rd) {
4691 if ((rd.module.flags() & Flags.AUTOMATIC_MODULE) != 0) {
4692 deferredLintHandler.report(_ -> {
4693 if (rd.isTransitive() && lint.isEnabled(LintCategory.REQUIRES_TRANSITIVE_AUTOMATIC)) {
4694 log.warning(pos, LintWarnings.RequiresTransitiveAutomatic);
4695 } else {
4696 lint.logIfEnabled(pos, LintWarnings.RequiresAutomatic);
4697 }
4698 });
4699 }
4700 }
4701
4702 /**
4703 * Verify the case labels conform to the constraints. Checks constraints related
4704 * combinations of patterns and other labels.
4705 *
4706 * @param cases the cases that should be checked.
4707 */
4708 void checkSwitchCaseStructure(List<JCCase> cases) {
4709 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4710 JCCase c = l.head;
4711 if (c.labels.head instanceof JCConstantCaseLabel constLabel) {
4712 if (TreeInfo.isNull(constLabel.expr)) {
4713 if (c.labels.tail.nonEmpty()) {
4714 if (c.labels.tail.head instanceof JCDefaultCaseLabel defLabel) {
4715 if (c.labels.tail.tail.nonEmpty()) {
4716 log.error(c.labels.tail.tail.head.pos(), Errors.InvalidCaseLabelCombination);
4717 }
4718 } else {
4719 log.error(c.labels.tail.head.pos(), Errors.InvalidCaseLabelCombination);
4720 }
4721 }
4722 } else {
4723 for (JCCaseLabel label : c.labels.tail) {
4724 if (!(label instanceof JCConstantCaseLabel) || TreeInfo.isNullCaseLabel(label)) {
4725 log.error(label.pos(), Errors.InvalidCaseLabelCombination);
4726 break;
4727 }
4728 }
4729 }
4730 } else if (c.labels.tail.nonEmpty()) {
4731 var patterCaseLabels = c.labels.stream().filter(ll -> ll instanceof JCPatternCaseLabel).map(cl -> (JCPatternCaseLabel)cl);
4732 var allUnderscore = patterCaseLabels.allMatch(pcl -> !hasBindings(pcl.getPattern()));
4733
4734 if (!allUnderscore) {
4735 log.error(c.labels.tail.head.pos(), Errors.FlowsThroughFromPattern);
4736 }
4737
4738 boolean allPatternCaseLabels = c.labels.stream().allMatch(p -> p instanceof JCPatternCaseLabel);
4739
4740 if (allPatternCaseLabels) {
4741 preview.checkSourceLevel(c.labels.tail.head.pos(), Feature.UNNAMED_VARIABLES);
4742 }
4743
4744 for (JCCaseLabel label : c.labels.tail) {
4745 if (label instanceof JCConstantCaseLabel) {
4746 log.error(label.pos(), Errors.InvalidCaseLabelCombination);
4747 break;
4748 }
4749 }
4750 }
4751 }
4752
4753 boolean isCaseStatementGroup = cases.nonEmpty() &&
4754 cases.head.caseKind == CaseTree.CaseKind.STATEMENT;
4755
4756 if (isCaseStatementGroup) {
4757 boolean previousCompletessNormally = false;
4758 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4759 JCCase c = l.head;
4760 if (previousCompletessNormally &&
4761 c.stats.nonEmpty() &&
4762 c.labels.head instanceof JCPatternCaseLabel patternLabel &&
4763 (hasBindings(patternLabel.pat) || hasBindings(c.guard))) {
4764 log.error(c.labels.head.pos(), Errors.FlowsThroughToPattern);
4765 } else if (c.stats.isEmpty() &&
4766 c.labels.head instanceof JCPatternCaseLabel patternLabel &&
4767 (hasBindings(patternLabel.pat) || hasBindings(c.guard)) &&
4768 hasStatements(l.tail)) {
4769 log.error(c.labels.head.pos(), Errors.FlowsThroughFromPattern);
4770 }
4771 previousCompletessNormally = c.completesNormally;
4772 }
4773 }
4774 }
4775
4776 boolean hasBindings(JCTree p) {
4777 boolean[] bindings = new boolean[1];
4778
4779 new TreeScanner() {
4780 @Override
4781 public void visitBindingPattern(JCBindingPattern tree) {
4782 bindings[0] |= !tree.var.sym.isUnnamedVariable();
4783 super.visitBindingPattern(tree);
4784 }
4785 }.scan(p);
4786
4787 return bindings[0];
4788 }
4789
4790 boolean hasStatements(List<JCCase> cases) {
4791 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4792 if (l.head.stats.nonEmpty()) {
4793 return true;
4794 }
4795 }
4796
4797 return false;
4798 }
4799 void checkSwitchCaseLabelDominated(JCCaseLabel unconditionalCaseLabel, List<JCCase> cases) {
4800 List<Pair<JCCase, JCCaseLabel>> caseLabels = List.nil();
4801 boolean seenDefault = false;
4802 boolean seenDefaultLabel = false;
4803 boolean warnDominatedByDefault = false;
4804 boolean unconditionalFound = false;
4805
4806 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4807 JCCase c = l.head;
4808 for (JCCaseLabel label : c.labels) {
4809 if (label.hasTag(DEFAULTCASELABEL)) {
4810 seenDefault = true;
4811 seenDefaultLabel |=
4812 TreeInfo.isNullCaseLabel(c.labels.head);
4813 continue;
4814 }
4815 if (TreeInfo.isNullCaseLabel(label)) {
4816 if (seenDefault) {
4817 log.error(label.pos(), Errors.PatternDominated);
4818 }
4819 continue;
4820 }
4821 if (seenDefault && !warnDominatedByDefault) {
4822 if (label.hasTag(PATTERNCASELABEL) ||
4823 (label instanceof JCConstantCaseLabel && seenDefaultLabel)) {
4824 log.error(label.pos(), Errors.PatternDominated);
4825 warnDominatedByDefault = true;
4826 }
4827 }
4828 Type currentType = labelType(label);
4829 for (Pair<JCCase, JCCaseLabel> caseAndLabel : caseLabels) {
4830 JCCase testCase = caseAndLabel.fst;
4831 JCCaseLabel testCaseLabel = caseAndLabel.snd;
4832 Type testType = labelType(testCaseLabel);
4833 boolean dominated = false;
4834 if (types.isUnconditionallyExact(currentType, testType) &&
4835 !currentType.hasTag(ERROR) && !testType.hasTag(ERROR)) {
4836 //the current label is potentially dominated by the existing (test) label, check:
4837 if (label instanceof JCConstantCaseLabel) {
4838 dominated |= !(testCaseLabel instanceof JCConstantCaseLabel) &&
4839 TreeInfo.unguardedCase(testCase);
4840 } else if (label instanceof JCPatternCaseLabel patternCL &&
4841 testCaseLabel instanceof JCPatternCaseLabel testPatternCaseLabel &&
4842 (testCase.equals(c) || TreeInfo.unguardedCase(testCase))) {
4843 dominated = patternDominated(testPatternCaseLabel.pat,
4844 patternCL.pat);
4845 }
4846 }
4847
4848 if (dominated) {
4849 log.error(label.pos(), Errors.PatternDominated);
4850 }
4851 }
4852 caseLabels = caseLabels.prepend(Pair.of(c, label));
4853 }
4854 }
4855 }
4856 //where:
4857 private Type labelType(JCCaseLabel label) {
4858 return types.erasure(switch (label.getTag()) {
4859 case PATTERNCASELABEL -> ((JCPatternCaseLabel) label).pat.type;
4860 case CONSTANTCASELABEL -> ((JCConstantCaseLabel) label).expr.type;
4861 default -> throw Assert.error("Unexpected tree kind: " + label.getTag());
4862 });
4863 }
4864 private boolean patternDominated(JCPattern existingPattern, JCPattern currentPattern) {
4865 Type existingPatternType = types.erasure(existingPattern.type);
4866 Type currentPatternType = types.erasure(currentPattern.type);
4867 if (!types.isUnconditionallyExact(currentPatternType, existingPatternType)) {
4868 return false;
4869 }
4870 if (currentPattern instanceof JCBindingPattern ||
4871 currentPattern instanceof JCAnyPattern) {
4872 return existingPattern instanceof JCBindingPattern ||
4873 existingPattern instanceof JCAnyPattern;
4874 } else if (currentPattern instanceof JCRecordPattern currentRecordPattern) {
4875 if (existingPattern instanceof JCBindingPattern ||
4876 existingPattern instanceof JCAnyPattern) {
4877 return true;
4878 } else if (existingPattern instanceof JCRecordPattern existingRecordPattern) {
4879 List<JCPattern> existingNested = existingRecordPattern.nested;
4880 List<JCPattern> currentNested = currentRecordPattern.nested;
4881 if (existingNested.size() != currentNested.size()) {
4882 return false;
4883 }
4884 while (existingNested.nonEmpty()) {
4885 if (!patternDominated(existingNested.head, currentNested.head)) {
4886 return false;
4887 }
4888 existingNested = existingNested.tail;
4889 currentNested = currentNested.tail;
4890 }
4891 return true;
4892 } else {
4893 Assert.error("Unknown pattern: " + existingPattern.getTag());
4894 }
4895 } else {
4896 Assert.error("Unknown pattern: " + currentPattern.getTag());
4897 }
4898 return false;
4899 }
4900
4901 /** check if a type is a subtype of Externalizable, if that is available. */
4902 boolean isExternalizable(Type t) {
4903 try {
4904 syms.externalizableType.complete();
4905 } catch (CompletionFailure e) {
4906 return false;
4907 }
4908 return types.isSubtype(t, syms.externalizableType);
4909 }
4910
4911 /**
4912 * Check structure of serialization declarations.
4913 */
4914 public void checkSerialStructure(JCClassDecl tree, ClassSymbol c) {
4915 (new SerialTypeVisitor()).visit(c, tree);
4916 }
4917
4918 /**
4919 * This visitor will warn if a serialization-related field or
4920 * method is declared in a suspicious or incorrect way. In
4921 * particular, it will warn for cases where the runtime
4922 * serialization mechanism will silently ignore a mis-declared
4923 * entity.
4924 *
4925 * Distinguished serialization-related fields and methods:
4926 *
4927 * Methods:
4928 *
4929 * private void writeObject(ObjectOutputStream stream) throws IOException
4930 * ANY-ACCESS-MODIFIER Object writeReplace() throws ObjectStreamException
4931 *
4932 * private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException
4933 * private void readObjectNoData() throws ObjectStreamException
4934 * ANY-ACCESS-MODIFIER Object readResolve() throws ObjectStreamException
4935 *
4936 * Fields:
4937 *
4938 * private static final long serialVersionUID
4939 * private static final ObjectStreamField[] serialPersistentFields
4940 *
4941 * Externalizable: methods defined on the interface
4942 * public void writeExternal(ObjectOutput) throws IOException
4943 * public void readExternal(ObjectInput) throws IOException
4944 */
4945 private class SerialTypeVisitor extends ElementKindVisitor14<Void, JCClassDecl> {
4946 SerialTypeVisitor() {
4947 this.lint = Check.this.lint;
4948 }
4949
4950 private static final Set<String> serialMethodNames =
4951 Set.of("writeObject", "writeReplace",
4952 "readObject", "readObjectNoData",
4953 "readResolve");
4954
4955 private static final Set<String> serialFieldNames =
4956 Set.of("serialVersionUID", "serialPersistentFields");
4957
4958 // Type of serialPersistentFields
4959 private final Type OSF_TYPE = new Type.ArrayType(syms.objectStreamFieldType, syms.arrayClass);
4960
4961 Lint lint;
4962
4963 @Override
4964 public Void defaultAction(Element e, JCClassDecl p) {
4965 throw new IllegalArgumentException(Objects.requireNonNullElse(e.toString(), ""));
4966 }
4967
4968 @Override
4969 public Void visitType(TypeElement e, JCClassDecl p) {
4970 runUnderLint(e, p, (symbol, param) -> super.visitType(symbol, param));
4971 return null;
4972 }
4973
4974 @Override
4975 public Void visitTypeAsClass(TypeElement e,
4976 JCClassDecl p) {
4977 // Anonymous classes filtered out by caller.
4978
4979 ClassSymbol c = (ClassSymbol)e;
4980
4981 checkCtorAccess(p, c);
4982
4983 // Check for missing serialVersionUID; check *not* done
4984 // for enums or records.
4985 VarSymbol svuidSym = null;
4986 for (Symbol sym : c.members().getSymbolsByName(names.serialVersionUID)) {
4987 if (sym.kind == VAR) {
4988 svuidSym = (VarSymbol)sym;
4989 break;
4990 }
4991 }
4992
4993 if (svuidSym == null) {
4994 log.warning(p.pos(), LintWarnings.MissingSVUID(c));
4995 }
4996
4997 // Check for serialPersistentFields to gate checks for
4998 // non-serializable non-transient instance fields
4999 boolean serialPersistentFieldsPresent =
5000 c.members()
5001 .getSymbolsByName(names.serialPersistentFields, sym -> sym.kind == VAR)
5002 .iterator()
5003 .hasNext();
5004
5005 // Check declarations of serialization-related methods and
5006 // fields
5007 for(Symbol el : c.getEnclosedElements()) {
5008 runUnderLint(el, p, (enclosed, tree) -> {
5009 String name = null;
5010 switch(enclosed.getKind()) {
5011 case FIELD -> {
5012 if (!serialPersistentFieldsPresent) {
5013 var flags = enclosed.flags();
5014 if ( ((flags & TRANSIENT) == 0) &&
5015 ((flags & STATIC) == 0)) {
5016 Type varType = enclosed.asType();
5017 if (!canBeSerialized(varType)) {
5018 // Note per JLS arrays are
5019 // serializable even if the
5020 // component type is not.
5021 log.warning(
5022 TreeInfo.diagnosticPositionFor(enclosed, tree),
5023 LintWarnings.NonSerializableInstanceField);
5024 } else if (varType.hasTag(ARRAY)) {
5025 ArrayType arrayType = (ArrayType)varType;
5026 Type elementType = arrayType.elemtype;
5027 while (elementType.hasTag(ARRAY)) {
5028 arrayType = (ArrayType)elementType;
5029 elementType = arrayType.elemtype;
5030 }
5031 if (!canBeSerialized(elementType)) {
5032 log.warning(
5033 TreeInfo.diagnosticPositionFor(enclosed, tree),
5034 LintWarnings.NonSerializableInstanceFieldArray(elementType));
5035 }
5036 }
5037 }
5038 }
5039
5040 name = enclosed.getSimpleName().toString();
5041 if (serialFieldNames.contains(name)) {
5042 VarSymbol field = (VarSymbol)enclosed;
5043 switch (name) {
5044 case "serialVersionUID" -> checkSerialVersionUID(tree, e, field);
5045 case "serialPersistentFields" -> checkSerialPersistentFields(tree, e, field);
5046 default -> throw new AssertionError();
5047 }
5048 }
5049 }
5050
5051 // Correctly checking the serialization-related
5052 // methods is subtle. For the methods declared to be
5053 // private or directly declared in the class, the
5054 // enclosed elements of the class can be checked in
5055 // turn. However, writeReplace and readResolve can be
5056 // declared in a superclass and inherited. Note that
5057 // the runtime lookup walks the superclass chain
5058 // looking for writeReplace/readResolve via
5059 // Class.getDeclaredMethod. This differs from calling
5060 // Elements.getAllMembers(TypeElement) as the latter
5061 // will also pull in default methods from
5062 // superinterfaces. In other words, the runtime checks
5063 // (which long predate default methods on interfaces)
5064 // do not admit the possibility of inheriting methods
5065 // this way, a difference from general inheritance.
5066
5067 // The current implementation just checks the enclosed
5068 // elements and does not directly check the inherited
5069 // methods. If all the types are being checked this is
5070 // less of a concern; however, there are cases that
5071 // could be missed. In particular, readResolve and
5072 // writeReplace could, in principle, by inherited from
5073 // a non-serializable superclass and thus not checked
5074 // even if compiled with a serializable child class.
5075 case METHOD -> {
5076 var method = (MethodSymbol)enclosed;
5077 name = method.getSimpleName().toString();
5078 if (serialMethodNames.contains(name)) {
5079 switch (name) {
5080 case "writeObject" -> checkWriteObject(tree, e, method);
5081 case "writeReplace" -> checkWriteReplace(tree,e, method);
5082 case "readObject" -> checkReadObject(tree,e, method);
5083 case "readObjectNoData" -> checkReadObjectNoData(tree, e, method);
5084 case "readResolve" -> checkReadResolve(tree, e, method);
5085 default -> throw new AssertionError();
5086 }
5087 }
5088 }
5089 }
5090 });
5091 }
5092
5093 return null;
5094 }
5095
5096 boolean canBeSerialized(Type type) {
5097 return type.isPrimitive() || rs.isSerializable(type);
5098 }
5099
5100 /**
5101 * Check that Externalizable class needs a public no-arg
5102 * constructor.
5103 *
5104 * Check that a Serializable class has access to the no-arg
5105 * constructor of its first nonserializable superclass.
5106 */
5107 private void checkCtorAccess(JCClassDecl tree, ClassSymbol c) {
5108 if (isExternalizable(c.type)) {
5109 for(var sym : c.getEnclosedElements()) {
5110 if (sym.isConstructor() &&
5111 ((sym.flags() & PUBLIC) == PUBLIC)) {
5112 if (((MethodSymbol)sym).getParameters().isEmpty()) {
5113 return;
5114 }
5115 }
5116 }
5117 log.warning(tree.pos(),
5118 LintWarnings.ExternalizableMissingPublicNoArgCtor);
5119 } else {
5120 // Approximate access to the no-arg constructor up in
5121 // the superclass chain by checking that the
5122 // constructor is not private. This may not handle
5123 // some cross-package situations correctly.
5124 Type superClass = c.getSuperclass();
5125 // java.lang.Object is *not* Serializable so this loop
5126 // should terminate.
5127 while (rs.isSerializable(superClass) ) {
5128 try {
5129 superClass = (Type)((TypeElement)(((DeclaredType)superClass)).asElement()).getSuperclass();
5130 } catch(ClassCastException cce) {
5131 return ; // Don't try to recover
5132 }
5133 }
5134 // Non-Serializable superclass
5135 try {
5136 ClassSymbol supertype = ((ClassSymbol)(((DeclaredType)superClass).asElement()));
5137 for(var sym : supertype.getEnclosedElements()) {
5138 if (sym.isConstructor()) {
5139 MethodSymbol ctor = (MethodSymbol)sym;
5140 if (ctor.getParameters().isEmpty()) {
5141 if (((ctor.flags() & PRIVATE) == PRIVATE) ||
5142 // Handle nested classes and implicit this$0
5143 (supertype.getNestingKind() == NestingKind.MEMBER &&
5144 ((supertype.flags() & STATIC) == 0)))
5145 log.warning(tree.pos(),
5146 LintWarnings.SerializableMissingAccessNoArgCtor(supertype.getQualifiedName()));
5147 }
5148 }
5149 }
5150 } catch (ClassCastException cce) {
5151 return ; // Don't try to recover
5152 }
5153 return;
5154 }
5155 }
5156
5157 private void checkSerialVersionUID(JCClassDecl tree, Element e, VarSymbol svuid) {
5158 // To be effective, serialVersionUID must be marked static
5159 // and final, but private is recommended. But alas, in
5160 // practice there are many non-private serialVersionUID
5161 // fields.
5162 if ((svuid.flags() & (STATIC | FINAL)) !=
5163 (STATIC | FINAL)) {
5164 log.warning(
5165 TreeInfo.diagnosticPositionFor(svuid, tree),
5166 LintWarnings.ImproperSVUID((Symbol)e));
5167 }
5168
5169 // check svuid has type long
5170 if (!svuid.type.hasTag(LONG)) {
5171 log.warning(
5172 TreeInfo.diagnosticPositionFor(svuid, tree),
5173 LintWarnings.LongSVUID((Symbol)e));
5174 }
5175
5176 if (svuid.getConstValue() == null)
5177 log.warning(
5178 TreeInfo.diagnosticPositionFor(svuid, tree),
5179 LintWarnings.ConstantSVUID((Symbol)e));
5180 }
5181
5182 private void checkSerialPersistentFields(JCClassDecl tree, Element e, VarSymbol spf) {
5183 // To be effective, serialPersisentFields must be private, static, and final.
5184 if ((spf.flags() & (PRIVATE | STATIC | FINAL)) !=
5185 (PRIVATE | STATIC | FINAL)) {
5186 log.warning(
5187 TreeInfo.diagnosticPositionFor(spf, tree),
5188 LintWarnings.ImproperSPF);
5189 }
5190
5191 if (!types.isSameType(spf.type, OSF_TYPE)) {
5192 log.warning(
5193 TreeInfo.diagnosticPositionFor(spf, tree),
5194 LintWarnings.OSFArraySPF);
5195 }
5196
5197 if (isExternalizable((Type)(e.asType()))) {
5198 log.warning(
5199 TreeInfo.diagnosticPositionFor(spf, tree),
5200 LintWarnings.IneffectualSerialFieldExternalizable);
5201 }
5202
5203 // Warn if serialPersistentFields is initialized to a
5204 // literal null.
5205 JCTree spfDecl = TreeInfo.declarationFor(spf, tree);
5206 if (spfDecl != null && spfDecl.getTag() == VARDEF) {
5207 JCVariableDecl variableDef = (JCVariableDecl) spfDecl;
5208 JCExpression initExpr = variableDef.init;
5209 if (initExpr != null && TreeInfo.isNull(initExpr)) {
5210 log.warning(initExpr.pos(),
5211 LintWarnings.SPFNullInit);
5212 }
5213 }
5214 }
5215
5216 private void checkWriteObject(JCClassDecl tree, Element e, MethodSymbol method) {
5217 // The "synchronized" modifier is seen in the wild on
5218 // readObject and writeObject methods and is generally
5219 // innocuous.
5220
5221 // private void writeObject(ObjectOutputStream stream) throws IOException
5222 checkPrivateNonStaticMethod(tree, method);
5223 checkReturnType(tree, e, method, syms.voidType);
5224 checkOneArg(tree, e, method, syms.objectOutputStreamType);
5225 checkExceptions(tree, e, method, syms.ioExceptionType);
5226 checkExternalizable(tree, e, method);
5227 }
5228
5229 private void checkWriteReplace(JCClassDecl tree, Element e, MethodSymbol method) {
5230 // ANY-ACCESS-MODIFIER Object writeReplace() throws
5231 // ObjectStreamException
5232
5233 // Excluding abstract, could have a more complicated
5234 // rule based on abstract-ness of the class
5235 checkConcreteInstanceMethod(tree, e, method);
5236 checkReturnType(tree, e, method, syms.objectType);
5237 checkNoArgs(tree, e, method);
5238 checkExceptions(tree, e, method, syms.objectStreamExceptionType);
5239 }
5240
5241 private void checkReadObject(JCClassDecl tree, Element e, MethodSymbol method) {
5242 // The "synchronized" modifier is seen in the wild on
5243 // readObject and writeObject methods and is generally
5244 // innocuous.
5245
5246 // private void readObject(ObjectInputStream stream)
5247 // throws IOException, ClassNotFoundException
5248 checkPrivateNonStaticMethod(tree, method);
5249 checkReturnType(tree, e, method, syms.voidType);
5250 checkOneArg(tree, e, method, syms.objectInputStreamType);
5251 checkExceptions(tree, e, method, syms.ioExceptionType, syms.classNotFoundExceptionType);
5252 checkExternalizable(tree, e, method);
5253 }
5254
5255 private void checkReadObjectNoData(JCClassDecl tree, Element e, MethodSymbol method) {
5256 // private void readObjectNoData() throws ObjectStreamException
5257 checkPrivateNonStaticMethod(tree, method);
5258 checkReturnType(tree, e, method, syms.voidType);
5259 checkNoArgs(tree, e, method);
5260 checkExceptions(tree, e, method, syms.objectStreamExceptionType);
5261 checkExternalizable(tree, e, method);
5262 }
5263
5264 private void checkReadResolve(JCClassDecl tree, Element e, MethodSymbol method) {
5265 // ANY-ACCESS-MODIFIER Object readResolve()
5266 // throws ObjectStreamException
5267
5268 // Excluding abstract, could have a more complicated
5269 // rule based on abstract-ness of the class
5270 checkConcreteInstanceMethod(tree, e, method);
5271 checkReturnType(tree,e, method, syms.objectType);
5272 checkNoArgs(tree, e, method);
5273 checkExceptions(tree, e, method, syms.objectStreamExceptionType);
5274 }
5275
5276 private void checkWriteExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) {
5277 //public void writeExternal(ObjectOutput) throws IOException
5278 checkExternMethodRecord(tree, e, method, syms.objectOutputType, isExtern);
5279 }
5280
5281 private void checkReadExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) {
5282 // public void readExternal(ObjectInput) throws IOException
5283 checkExternMethodRecord(tree, e, method, syms.objectInputType, isExtern);
5284 }
5285
5286 private void checkExternMethodRecord(JCClassDecl tree, Element e, MethodSymbol method, Type argType,
5287 boolean isExtern) {
5288 if (isExtern && isExternMethod(tree, e, method, argType)) {
5289 log.warning(
5290 TreeInfo.diagnosticPositionFor(method, tree),
5291 LintWarnings.IneffectualExternalizableMethodRecord(method.getSimpleName().toString()));
5292 }
5293 }
5294
5295 void checkPrivateNonStaticMethod(JCClassDecl tree, MethodSymbol method) {
5296 var flags = method.flags();
5297 if ((flags & PRIVATE) == 0) {
5298 log.warning(
5299 TreeInfo.diagnosticPositionFor(method, tree),
5300 LintWarnings.SerialMethodNotPrivate(method.getSimpleName()));
5301 }
5302
5303 if ((flags & STATIC) != 0) {
5304 log.warning(
5305 TreeInfo.diagnosticPositionFor(method, tree),
5306 LintWarnings.SerialMethodStatic(method.getSimpleName()));
5307 }
5308 }
5309
5310 /**
5311 * Per section 1.12 "Serialization of Enum Constants" of
5312 * the serialization specification, due to the special
5313 * serialization handling of enums, any writeObject,
5314 * readObject, writeReplace, and readResolve methods are
5315 * ignored as are serialPersistentFields and
5316 * serialVersionUID fields.
5317 */
5318 @Override
5319 public Void visitTypeAsEnum(TypeElement e,
5320 JCClassDecl p) {
5321 boolean isExtern = isExternalizable((Type)e.asType());
5322 for(Element el : e.getEnclosedElements()) {
5323 runUnderLint(el, p, (enclosed, tree) -> {
5324 String name = enclosed.getSimpleName().toString();
5325 switch(enclosed.getKind()) {
5326 case FIELD -> {
5327 var field = (VarSymbol)enclosed;
5328 if (serialFieldNames.contains(name)) {
5329 log.warning(
5330 TreeInfo.diagnosticPositionFor(field, tree),
5331 LintWarnings.IneffectualSerialFieldEnum(name));
5332 }
5333 }
5334
5335 case METHOD -> {
5336 var method = (MethodSymbol)enclosed;
5337 if (serialMethodNames.contains(name)) {
5338 log.warning(
5339 TreeInfo.diagnosticPositionFor(method, tree),
5340 LintWarnings.IneffectualSerialMethodEnum(name));
5341 }
5342
5343 if (isExtern) {
5344 switch(name) {
5345 case "writeExternal" -> checkWriteExternalEnum(tree, e, method);
5346 case "readExternal" -> checkReadExternalEnum(tree, e, method);
5347 }
5348 }
5349 }
5350
5351 // Also perform checks on any class bodies of enum constants, see JLS 8.9.1.
5352 case ENUM_CONSTANT -> {
5353 var field = (VarSymbol)enclosed;
5354 JCVariableDecl decl = (JCVariableDecl) TreeInfo.declarationFor(field, p);
5355 if (decl.init instanceof JCNewClass nc && nc.def != null) {
5356 ClassSymbol enumConstantType = nc.def.sym;
5357 visitTypeAsEnum(enumConstantType, p);
5358 }
5359 }
5360
5361 }});
5362 }
5363 return null;
5364 }
5365
5366 private void checkWriteExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) {
5367 //public void writeExternal(ObjectOutput) throws IOException
5368 checkExternMethodEnum(tree, e, method, syms.objectOutputType);
5369 }
5370
5371 private void checkReadExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) {
5372 // public void readExternal(ObjectInput) throws IOException
5373 checkExternMethodEnum(tree, e, method, syms.objectInputType);
5374 }
5375
5376 private void checkExternMethodEnum(JCClassDecl tree, Element e, MethodSymbol method, Type argType) {
5377 if (isExternMethod(tree, e, method, argType)) {
5378 log.warning(
5379 TreeInfo.diagnosticPositionFor(method, tree),
5380 LintWarnings.IneffectualExternMethodEnum(method.getSimpleName().toString()));
5381 }
5382 }
5383
5384 private boolean isExternMethod(JCClassDecl tree, Element e, MethodSymbol method, Type argType) {
5385 long flags = method.flags();
5386 Type rtype = method.getReturnType();
5387
5388 // Not necessary to check throws clause in this context
5389 return (flags & PUBLIC) != 0 && (flags & STATIC) == 0 &&
5390 types.isSameType(syms.voidType, rtype) &&
5391 hasExactlyOneArgWithType(tree, e, method, argType);
5392 }
5393
5394 /**
5395 * Most serialization-related fields and methods on interfaces
5396 * are ineffectual or problematic.
5397 */
5398 @Override
5399 public Void visitTypeAsInterface(TypeElement e,
5400 JCClassDecl p) {
5401 for(Element el : e.getEnclosedElements()) {
5402 runUnderLint(el, p, (enclosed, tree) -> {
5403 String name = null;
5404 switch(enclosed.getKind()) {
5405 case FIELD -> {
5406 var field = (VarSymbol)enclosed;
5407 name = field.getSimpleName().toString();
5408 switch(name) {
5409 case "serialPersistentFields" -> {
5410 log.warning(
5411 TreeInfo.diagnosticPositionFor(field, tree),
5412 LintWarnings.IneffectualSerialFieldInterface);
5413 }
5414
5415 case "serialVersionUID" -> {
5416 checkSerialVersionUID(tree, e, field);
5417 }
5418 }
5419 }
5420
5421 case METHOD -> {
5422 var method = (MethodSymbol)enclosed;
5423 name = enclosed.getSimpleName().toString();
5424 if (serialMethodNames.contains(name)) {
5425 switch (name) {
5426 case
5427 "readObject",
5428 "readObjectNoData",
5429 "writeObject" -> checkPrivateMethod(tree, e, method);
5430
5431 case
5432 "writeReplace",
5433 "readResolve" -> checkDefaultIneffective(tree, e, method);
5434
5435 default -> throw new AssertionError();
5436 }
5437
5438 }
5439 }}
5440 });
5441 }
5442
5443 return null;
5444 }
5445
5446 private void checkPrivateMethod(JCClassDecl tree,
5447 Element e,
5448 MethodSymbol method) {
5449 if ((method.flags() & PRIVATE) == 0) {
5450 log.warning(
5451 TreeInfo.diagnosticPositionFor(method, tree),
5452 LintWarnings.NonPrivateMethodWeakerAccess);
5453 }
5454 }
5455
5456 private void checkDefaultIneffective(JCClassDecl tree,
5457 Element e,
5458 MethodSymbol method) {
5459 if ((method.flags() & DEFAULT) == DEFAULT) {
5460 log.warning(
5461 TreeInfo.diagnosticPositionFor(method, tree),
5462 LintWarnings.DefaultIneffective);
5463
5464 }
5465 }
5466
5467 @Override
5468 public Void visitTypeAsAnnotationType(TypeElement e,
5469 JCClassDecl p) {
5470 // Per the JLS, annotation types are not serializeable
5471 return null;
5472 }
5473
5474 /**
5475 * From the Java Object Serialization Specification, 1.13
5476 * Serialization of Records:
5477 *
5478 * "The process by which record objects are serialized or
5479 * externalized cannot be customized; any class-specific
5480 * writeObject, readObject, readObjectNoData, writeExternal,
5481 * and readExternal methods defined by record classes are
5482 * ignored during serialization and deserialization. However,
5483 * a substitute object to be serialized or a designate
5484 * replacement may be specified, by the writeReplace and
5485 * readResolve methods, respectively. Any
5486 * serialPersistentFields field declaration is
5487 * ignored. Documenting serializable fields and data for
5488 * record classes is unnecessary, since there is no variation
5489 * in the serial form, other than whether a substitute or
5490 * replacement object is used. The serialVersionUID of a
5491 * record class is 0L unless explicitly declared. The
5492 * requirement for matching serialVersionUID values is waived
5493 * for record classes."
5494 */
5495 @Override
5496 public Void visitTypeAsRecord(TypeElement e,
5497 JCClassDecl p) {
5498 boolean isExtern = isExternalizable((Type)e.asType());
5499 for(Element el : e.getEnclosedElements()) {
5500 runUnderLint(el, p, (enclosed, tree) -> {
5501 String name = enclosed.getSimpleName().toString();
5502 switch(enclosed.getKind()) {
5503 case FIELD -> {
5504 var field = (VarSymbol)enclosed;
5505 switch(name) {
5506 case "serialPersistentFields" -> {
5507 log.warning(
5508 TreeInfo.diagnosticPositionFor(field, tree),
5509 LintWarnings.IneffectualSerialFieldRecord);
5510 }
5511
5512 case "serialVersionUID" -> {
5513 // Could generate additional warning that
5514 // svuid value is not checked to match for
5515 // records.
5516 checkSerialVersionUID(tree, e, field);
5517 }}
5518 }
5519
5520 case METHOD -> {
5521 var method = (MethodSymbol)enclosed;
5522 switch(name) {
5523 case "writeReplace" -> checkWriteReplace(tree, e, method);
5524 case "readResolve" -> checkReadResolve(tree, e, method);
5525
5526 case "writeExternal" -> checkWriteExternalRecord(tree, e, method, isExtern);
5527 case "readExternal" -> checkReadExternalRecord(tree, e, method, isExtern);
5528
5529 default -> {
5530 if (serialMethodNames.contains(name)) {
5531 log.warning(
5532 TreeInfo.diagnosticPositionFor(method, tree),
5533 LintWarnings.IneffectualSerialMethodRecord(name));
5534 }
5535 }}
5536 }}});
5537 }
5538 return null;
5539 }
5540
5541 void checkConcreteInstanceMethod(JCClassDecl tree,
5542 Element enclosing,
5543 MethodSymbol method) {
5544 if ((method.flags() & (STATIC | ABSTRACT)) != 0) {
5545 log.warning(
5546 TreeInfo.diagnosticPositionFor(method, tree),
5547 LintWarnings.SerialConcreteInstanceMethod(method.getSimpleName()));
5548 }
5549 }
5550
5551 private void checkReturnType(JCClassDecl tree,
5552 Element enclosing,
5553 MethodSymbol method,
5554 Type expectedReturnType) {
5555 // Note: there may be complications checking writeReplace
5556 // and readResolve since they return Object and could, in
5557 // principle, have covariant overrides and any synthetic
5558 // bridge method would not be represented here for
5559 // checking.
5560 Type rtype = method.getReturnType();
5561 if (!types.isSameType(expectedReturnType, rtype)) {
5562 log.warning(
5563 TreeInfo.diagnosticPositionFor(method, tree),
5564 LintWarnings.SerialMethodUnexpectedReturnType(method.getSimpleName(),
5565 rtype, expectedReturnType));
5566 }
5567 }
5568
5569 private void checkOneArg(JCClassDecl tree,
5570 Element enclosing,
5571 MethodSymbol method,
5572 Type expectedType) {
5573 String name = method.getSimpleName().toString();
5574
5575 var parameters= method.getParameters();
5576
5577 if (parameters.size() != 1) {
5578 log.warning(
5579 TreeInfo.diagnosticPositionFor(method, tree),
5580 LintWarnings.SerialMethodOneArg(method.getSimpleName(), parameters.size()));
5581 return;
5582 }
5583
5584 Type parameterType = parameters.get(0).asType();
5585 if (!types.isSameType(parameterType, expectedType)) {
5586 log.warning(
5587 TreeInfo.diagnosticPositionFor(method, tree),
5588 LintWarnings.SerialMethodParameterType(method.getSimpleName(),
5589 expectedType,
5590 parameterType));
5591 }
5592 }
5593
5594 private boolean hasExactlyOneArgWithType(JCClassDecl tree,
5595 Element enclosing,
5596 MethodSymbol method,
5597 Type expectedType) {
5598 var parameters = method.getParameters();
5599 return (parameters.size() == 1) &&
5600 types.isSameType(parameters.get(0).asType(), expectedType);
5601 }
5602
5603
5604 private void checkNoArgs(JCClassDecl tree, Element enclosing, MethodSymbol method) {
5605 var parameters = method.getParameters();
5606 if (!parameters.isEmpty()) {
5607 log.warning(
5608 TreeInfo.diagnosticPositionFor(parameters.get(0), tree),
5609 LintWarnings.SerialMethodNoArgs(method.getSimpleName()));
5610 }
5611 }
5612
5613 private void checkExternalizable(JCClassDecl tree, Element enclosing, MethodSymbol method) {
5614 // If the enclosing class is externalizable, warn for the method
5615 if (isExternalizable((Type)enclosing.asType())) {
5616 log.warning(
5617 TreeInfo.diagnosticPositionFor(method, tree),
5618 LintWarnings.IneffectualSerialMethodExternalizable(method.getSimpleName()));
5619 }
5620 return;
5621 }
5622
5623 private void checkExceptions(JCClassDecl tree,
5624 Element enclosing,
5625 MethodSymbol method,
5626 Type... declaredExceptions) {
5627 for (Type thrownType: method.getThrownTypes()) {
5628 // For each exception in the throws clause of the
5629 // method, if not an Error and not a RuntimeException,
5630 // check if the exception is a subtype of a declared
5631 // exception from the throws clause of the
5632 // serialization method in question.
5633 if (types.isSubtype(thrownType, syms.runtimeExceptionType) ||
5634 types.isSubtype(thrownType, syms.errorType) ) {
5635 continue;
5636 } else {
5637 boolean declared = false;
5638 for (Type declaredException : declaredExceptions) {
5639 if (types.isSubtype(thrownType, declaredException)) {
5640 declared = true;
5641 continue;
5642 }
5643 }
5644 if (!declared) {
5645 log.warning(
5646 TreeInfo.diagnosticPositionFor(method, tree),
5647 LintWarnings.SerialMethodUnexpectedException(method.getSimpleName(),
5648 thrownType));
5649 }
5650 }
5651 }
5652 return;
5653 }
5654
5655 private <E extends Element> Void runUnderLint(E symbol, JCClassDecl p, BiConsumer<E, JCClassDecl> task) {
5656 Lint prevLint = lint;
5657 try {
5658 lint = lint.augment((Symbol) symbol);
5659
5660 if (lint.isEnabled(LintCategory.SERIAL)) {
5661 task.accept(symbol, p);
5662 }
5663
5664 return null;
5665 } finally {
5666 lint = prevLint;
5667 }
5668 }
5669
5670 }
5671
5672 void checkRequiresIdentity(JCTree tree, Lint lint) {
5673 switch (tree) {
5674 case JCClassDecl classDecl -> {
5675 Type st = types.supertype(classDecl.sym.type);
5676 if (st != null &&
5677 // no need to recheck j.l.Object, shortcut,
5678 st.tsym != syms.objectType.tsym &&
5679 // this one could be null, no explicit extends
5680 classDecl.extending != null) {
5681 checkIfIdentityIsExpected(classDecl.extending.pos(), st, lint);
5682 }
5683 for (JCExpression intrface: classDecl.implementing) {
5684 checkIfIdentityIsExpected(intrface.pos(), intrface.type, lint);
5685 }
5686 for (JCTypeParameter tp : classDecl.typarams) {
5687 checkIfIdentityIsExpected(tp.pos(), tp.type, lint);
5688 }
5689 }
5690 case JCVariableDecl variableDecl -> {
5691 if (variableDecl.vartype != null &&
5692 (variableDecl.sym.flags_field & RECORD) == 0 ||
5693 (variableDecl.sym.flags_field & ~(Flags.PARAMETER | RECORD | GENERATED_MEMBER)) != 0) {
5694 /* we don't want to warn twice so if this variable is a compiler generated parameter of
5695 * a canonical record constructor, we don't want to issue a warning as we will warn the
5696 * corresponding compiler generated private record field anyways
5697 */
5698 checkIfIdentityIsExpected(variableDecl.vartype.pos(), variableDecl.vartype.type, lint);
5699 }
5700 }
5701 case JCTypeCast typeCast -> checkIfIdentityIsExpected(typeCast.clazz.pos(), typeCast.clazz.type, lint);
5702 case JCBindingPattern bindingPattern -> {
5703 if (bindingPattern.var.vartype != null) {
5704 checkIfIdentityIsExpected(bindingPattern.var.vartype.pos(), bindingPattern.var.vartype.type, lint);
5705 }
5706 }
5707 case JCMethodDecl methodDecl -> {
5708 for (JCTypeParameter tp : methodDecl.typarams) {
5709 checkIfIdentityIsExpected(tp.pos(), tp.type, lint);
5710 }
5711 if (methodDecl.restype != null && !methodDecl.restype.type.hasTag(VOID)) {
5712 checkIfIdentityIsExpected(methodDecl.restype.pos(), methodDecl.restype.type, lint);
5713 }
5714 }
5715 case JCMemberReference mref -> {
5716 checkIfIdentityIsExpected(mref.expr.pos(), mref.target, lint);
5717 checkIfTypeParamsRequiresIdentity(mref.sym.getMetadata(), mref.typeargs, lint);
5718 }
5719 case JCPolyExpression poly
5720 when (poly instanceof JCNewClass || poly instanceof JCMethodInvocation) -> {
5721 if (poly instanceof JCNewClass newClass) {
5722 checkIfIdentityIsExpected(newClass.clazz.pos(), newClass.clazz.type, lint);
5723 }
5724 List<JCExpression> argExps = poly instanceof JCNewClass ?
5725 ((JCNewClass)poly).args :
5726 ((JCMethodInvocation)poly).args;
5727 Symbol msym = TreeInfo.symbolFor(poly);
5728 if (msym != null) {
5729 if (!argExps.isEmpty() && msym instanceof MethodSymbol ms && ms.params != null) {
5730 VarSymbol lastParam = ms.params.head;
5731 for (VarSymbol param: ms.params) {
5732 if ((param.flags_field & REQUIRES_IDENTITY) != 0 && argExps.head.type.isValueBased()) {
5733 lint.logIfEnabled(argExps.head.pos(), LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5734 }
5735 lastParam = param;
5736 argExps = argExps.tail;
5737 }
5738 while (argExps != null && !argExps.isEmpty() && lastParam != null) {
5739 if ((lastParam.flags_field & REQUIRES_IDENTITY) != 0 && argExps.head.type.isValueBased()) {
5740 lint.logIfEnabled(argExps.head.pos(), LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5741 }
5742 argExps = argExps.tail;
5743 }
5744 }
5745 checkIfTypeParamsRequiresIdentity(
5746 msym.getMetadata(),
5747 poly instanceof JCNewClass ?
5748 ((JCNewClass)poly).typeargs :
5749 ((JCMethodInvocation)poly).typeargs,
5750 lint);
5751 }
5752 }
5753 default -> throw new AssertionError("unexpected tree " + tree);
5754 }
5755 }
5756
5757 /** Check if a type required an identity class
5758 */
5759 private boolean checkIfIdentityIsExpected(DiagnosticPosition pos, Type t, Lint lint) {
5760 if (t != null &&
5761 lint != null &&
5762 lint.isEnabled(LintCategory.IDENTITY)) {
5763 RequiresIdentityVisitor requiresIdentityVisitor = new RequiresIdentityVisitor();
5764 // we need to avoid recursion due to self referencing type vars or captures, this is why we need a set
5765 requiresIdentityVisitor.visit(t, new HashSet<>());
5766 if (requiresIdentityVisitor.requiresWarning) {
5767 lint.logIfEnabled(pos, LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5768 return true;
5769 }
5770 }
5771 return false;
5772 }
5773
5774 // where
5775 private class RequiresIdentityVisitor extends Types.SimpleVisitor<Void, Set<Type>> {
5776 boolean requiresWarning = false;
5777
5778 @Override
5779 public Void visitType(Type t, Set<Type> seen) {
5780 return null;
5781 }
5782
5783 @Override
5784 public Void visitWildcardType(WildcardType t, Set<Type> seen) {
5785 return visit(t.type, seen);
5786 }
5787
5788 @Override
5789 public Void visitTypeVar(TypeVar t, Set<Type> seen) {
5790 if (seen.add(t)) {
5791 visit(t.getUpperBound(), seen);
5792 }
5793 return null;
5794 }
5795
5796 @Override
5797 public Void visitCapturedType(CapturedType t, Set<Type> seen) {
5798 if (seen.add(t)) {
5799 visit(t.getUpperBound(), seen);
5800 visit(t.getLowerBound(), seen);
5801 }
5802 return null;
5803 }
5804
5805 @Override
5806 public Void visitArrayType(ArrayType t, Set<Type> seen) {
5807 return visit(t.elemtype, seen);
5808 }
5809
5810 @Override
5811 public Void visitClassType(ClassType t, Set<Type> seen) {
5812 if (t != null && t.tsym != null) {
5813 SymbolMetadata sm = t.tsym.getMetadata();
5814 if (sm != null && !t.getTypeArguments().isEmpty()) {
5815 if (sm.getTypeAttributes().stream()
5816 .filter(ta -> isRequiresIdentityAnnotation(ta.type.tsym) &&
5817 t.getTypeArguments().get(ta.position.parameter_index) != null &&
5818 t.getTypeArguments().get(ta.position.parameter_index).isValueBased()).findAny().isPresent()) {
5819 requiresWarning = true;
5820 return null;
5821 }
5822 }
5823 }
5824 visit(t.getEnclosingType(), seen);
5825 for (Type targ : t.getTypeArguments()) {
5826 visit(targ, seen);
5827 }
5828 return null;
5829 }
5830 } // RequiresIdentityVisitor
5831
5832 private void checkIfTypeParamsRequiresIdentity(SymbolMetadata sm,
5833 List<JCExpression> typeParamTrees,
5834 Lint lint) {
5835 if (typeParamTrees != null && !typeParamTrees.isEmpty()) {
5836 for (JCExpression targ : typeParamTrees) {
5837 checkIfIdentityIsExpected(targ.pos(), targ.type, lint);
5838 }
5839 if (sm != null)
5840 sm.getTypeAttributes().stream()
5841 .filter(ta -> isRequiresIdentityAnnotation(ta.type.tsym) &&
5842 typeParamTrees.get(ta.position.parameter_index).type != null &&
5843 typeParamTrees.get(ta.position.parameter_index).type.isValueBased())
5844 .forEach(ta -> lint.logIfEnabled(typeParamTrees.get(ta.position.parameter_index).pos(),
5845 CompilerProperties.LintWarnings.AttemptToUseValueBasedWhereIdentityExpected));
5846 }
5847 }
5848
5849 private boolean isRequiresIdentityAnnotation(TypeSymbol annoType) {
5850 return annoType == syms.requiresIdentityType.tsym ||
5851 annoType.flatName() == syms.requiresIdentityInternalType.tsym.flatName();
5852 }
5853 }