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