1 /*
2 * Copyright (c) 1999, 2026, 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;
50 import com.sun.tools.javac.resources.CompilerProperties.Errors;
51 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
52 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
53 import com.sun.tools.javac.resources.CompilerProperties.LintWarnings;
54 import com.sun.tools.javac.tree.*;
55 import com.sun.tools.javac.util.*;
56 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
57 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
58 import com.sun.tools.javac.util.JCDiagnostic.Error;
59 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
60 import com.sun.tools.javac.util.JCDiagnostic.LintWarning;
61 import com.sun.tools.javac.util.List;
62
63 import com.sun.tools.javac.code.Lint;
64 import com.sun.tools.javac.code.Lint.LintCategory;
65 import com.sun.tools.javac.code.Scope.WriteableScope;
66 import com.sun.tools.javac.code.Type.*;
67 import com.sun.tools.javac.code.Symbol.*;
68 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
69 import com.sun.tools.javac.tree.JCTree.*;
70
71 import static com.sun.tools.javac.code.Flags.*;
72 import static com.sun.tools.javac.code.Flags.ANNOTATION;
73 import static com.sun.tools.javac.code.Flags.SYNCHRONIZED;
74 import static com.sun.tools.javac.code.Kinds.*;
75 import static com.sun.tools.javac.code.Kinds.Kind.*;
76 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
77 import static com.sun.tools.javac.code.Scope.LookupKind.RECURSIVE;
78 import static com.sun.tools.javac.code.TypeTag.*;
79 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
80
81 import static com.sun.tools.javac.tree.JCTree.Tag.*;
82 import javax.lang.model.element.Element;
83 import javax.lang.model.element.TypeElement;
84 import javax.lang.model.type.DeclaredType;
85 import javax.lang.model.util.ElementKindVisitor14;
86
87 /** Type checking helper class for the attribution phase.
88 *
89 * <p><b>This is NOT part of any supported API.
90 * If you write code that depends on this, you do so at your own risk.
91 * This code and its internal interfaces are subject to change or
92 * deletion without notice.</b>
93 */
94 public class Check {
95 protected static final Context.Key<Check> checkKey = new Context.Key<>();
96
97 // Flag bits indicating which item(s) chosen from a pair of items
98 private static final int FIRST = 0x01;
99 private static final int SECOND = 0x02;
100
101 private final Names names;
102 private final Log log;
103 private final Resolve rs;
104 private final Symtab syms;
105 private final Enter enter;
106 private final DeferredAttr deferredAttr;
107 private final Infer infer;
108 private final Types types;
109 private final TypeAnnotations typeAnnotations;
110 private final JCDiagnostic.Factory diags;
111 private final JavaFileManager fileManager;
112 private final Source source;
113 private final Target target;
114 private final Profile profile;
115 private final Preview preview;
116 private final boolean warnOnAnyAccessToMembers;
117
118 public boolean disablePreviewCheck;
119
120 // The set of lint options currently in effect. It is initialized
121 // from the context, and then is set/reset as needed by Attr as it
122 // visits all the various parts of the trees during attribution.
123 private Lint lint;
124
125 // The method being analyzed in Attr - it is set/reset as needed by
126 // Attr as it visits new method declarations.
127 private MethodSymbol method;
128
129 public static Check instance(Context context) {
130 Check instance = context.get(checkKey);
131 if (instance == null)
132 instance = new Check(context);
133 return instance;
134 }
135
136 @SuppressWarnings("this-escape")
137 protected Check(Context context) {
138 context.put(checkKey, this);
139
140 names = Names.instance(context);
141 log = Log.instance(context);
142 rs = Resolve.instance(context);
143 syms = Symtab.instance(context);
144 enter = Enter.instance(context);
145 deferredAttr = DeferredAttr.instance(context);
146 infer = Infer.instance(context);
147 types = Types.instance(context);
148 typeAnnotations = TypeAnnotations.instance(context);
149 diags = JCDiagnostic.Factory.instance(context);
150 Options options = Options.instance(context);
151 lint = Lint.instance(context);
152 fileManager = context.get(JavaFileManager.class);
153
154 source = Source.instance(context);
155 target = Target.instance(context);
156 warnOnAnyAccessToMembers = options.isSet("warnOnAccessToMembers");
157
158 disablePreviewCheck = false;
159
160 Target target = Target.instance(context);
161 syntheticNameChar = target.syntheticNameChar();
162
163 profile = Profile.instance(context);
164 preview = Preview.instance(context);
165
166 allowModules = Feature.MODULES.allowedInSource(source);
167 allowRecords = Feature.RECORDS.allowedInSource(source);
168 allowSealed = Feature.SEALED_CLASSES.allowedInSource(source);
169 allowPrimitivePatterns = preview.isEnabled() && Feature.PRIMITIVE_PATTERNS.allowedInSource(source);
170 allowValueClasses = preview.isEnabled() && Feature.VALUE_CLASSES.allowedInSource(source);
171 }
172
173 /** Character for synthetic names
174 */
175 char syntheticNameChar;
176
177 /** A table mapping flat names of all compiled classes for each module in this run
178 * to their symbols; maintained from outside.
179 */
180 private Map<Pair<ModuleSymbol, Name>,ClassSymbol> compiled = new HashMap<>();
181
182 /** Are modules allowed
183 */
184 private final boolean allowModules;
185
186 /** Are records allowed
187 */
188 private final boolean allowRecords;
189
190 /** Are sealed classes allowed
191 */
192 private final boolean allowSealed;
193
194 /** Are primitive patterns allowed
195 */
196 private final boolean allowPrimitivePatterns;
197
198 /** Are value classes allowed
199 */
200 private final boolean allowValueClasses;
201
202 /** Whether to force suppression of deprecation and preview warnings.
203 * This happens when attributing import statements for JDK 9+.
204 * @see Feature#DEPRECATION_ON_IMPORT
205 */
206 private boolean importSuppression;
207
208 /* *************************************************************************
209 * Errors and Warnings
210 **************************************************************************/
211
212 Lint setLint(Lint newLint) {
213 Lint prev = lint;
214 lint = newLint;
215 return prev;
216 }
217
218 boolean setImportSuppression(boolean newImportSuppression) {
219 boolean prev = importSuppression;
220 importSuppression = newImportSuppression;
221 return prev;
222 }
223
224 MethodSymbol setMethod(MethodSymbol newMethod) {
225 MethodSymbol prev = method;
226 method = newMethod;
227 return prev;
228 }
229
230 /** Warn about deprecated symbol.
231 * @param pos Position to be used for error reporting.
232 * @param sym The deprecated symbol.
233 */
234 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
235 Assert.check(!importSuppression);
236 LintWarning warningKey = sym.isDeprecatedForRemoval() ?
237 (sym.kind == MDL ?
238 LintWarnings.HasBeenDeprecatedForRemovalModule(sym) :
239 LintWarnings.HasBeenDeprecatedForRemoval(sym, sym.location())) :
240 (sym.kind == MDL ?
241 LintWarnings.HasBeenDeprecatedModule(sym) :
242 LintWarnings.HasBeenDeprecated(sym, sym.location()));
243 log.warning(pos, warningKey);
244 }
245
246 /** Log a preview warning.
247 * @param pos Position to be used for error reporting.
248 * @param msg A Warning describing the problem.
249 */
250 public void warnPreviewAPI(DiagnosticPosition pos, LintWarning warnKey) {
251 if (!importSuppression)
252 log.warning(pos, warnKey);
253 }
254
255 /** Warn about unchecked operation.
256 * @param pos Position to be used for error reporting.
257 * @param msg A string describing the problem.
258 */
259 public void warnUnchecked(DiagnosticPosition pos, LintWarning warnKey) {
260 log.warning(pos, warnKey);
261 }
262
263 /** Report a failure to complete a class.
264 * @param pos Position to be used for error reporting.
265 * @param ex The failure to report.
266 */
267 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
268 log.error(DiagnosticFlag.NON_DEFERRABLE, pos, Errors.CantAccess(ex.sym, ex.getDetailValue()));
269 return syms.errType;
270 }
271
272 /** Report an error that wrong type tag was found.
273 * @param pos Position to be used for error reporting.
274 * @param required An internationalized string describing the type tag
275 * required.
276 * @param type The type that was found.
277 */
278 Type typeTagError(DiagnosticPosition pos, JCDiagnostic required, Type type) {
279 // this error used to be raised by the parser,
280 // but has been delayed to this point:
281 if (type.hasTag(VOID)) {
282 log.error(pos, Errors.IllegalStartOfType);
283 return syms.errType;
284 }
285 log.error(pos, Errors.TypeFoundReq(asTypeParam(type), required));
286 return types.createErrorType(type);
287 }
288
289 /** Report duplicate declaration error.
290 */
291 void duplicateError(DiagnosticPosition pos, Symbol sym) {
292 if (!sym.type.isErroneous()) {
293 Symbol location = sym.location();
294 if (location.kind == MTH &&
295 ((MethodSymbol)location).isStaticOrInstanceInit()) {
296 log.error(pos,
297 Errors.AlreadyDefinedInClinit(kindName(sym),
298 sym,
299 kindName(sym.location()),
300 kindName(sym.location().enclClass()),
301 sym.location().enclClass()));
302 } else {
303 /* dont error if this is a duplicated parameter of a generated canonical constructor
304 * as we should have issued an error for the duplicated fields
305 */
306 if (location.kind != MTH ||
307 ((sym.owner.flags_field & GENERATEDCONSTR) == 0) ||
308 ((sym.owner.flags_field & RECORD) == 0)) {
309 log.error(pos,
310 Errors.AlreadyDefined(kindName(sym),
311 sym,
312 kindName(sym.location()),
313 sym.location()));
314 }
315 }
316 }
317 }
318
319 /** Report array/varargs duplicate declaration
320 */
321 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
322 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
323 log.error(pos, Errors.ArrayAndVarargs(sym1, sym2, sym2.location()));
324 }
325 }
326
327 /* ************************************************************************
328 * duplicate declaration checking
329 *************************************************************************/
330
331 /** Check that variable does not hide variable with same name in
332 * immediately enclosing local scope.
333 * @param pos Position for error reporting.
334 * @param v The symbol.
335 * @param s The scope.
336 */
337 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
338 for (Symbol sym : s.getSymbolsByName(v.name)) {
339 if (sym.owner != v.owner) break;
340 if (sym.kind == VAR &&
341 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
342 v.name != names.error) {
343 duplicateError(pos, sym);
344 return;
345 }
346 }
347 }
348
349 /** Check that a class or interface does not hide a class or
350 * interface with same name in immediately enclosing local scope.
351 * @param pos Position for error reporting.
352 * @param c The symbol.
353 * @param s The scope.
354 */
355 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
356 for (Symbol sym : s.getSymbolsByName(c.name)) {
357 if (sym.owner != c.owner) break;
358 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR) &&
359 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
360 c.name != names.error) {
361 duplicateError(pos, sym);
362 return;
363 }
364 }
365 }
366
367 /** Check that class does not have the same name as one of
368 * its enclosing classes, or as a class defined in its enclosing scope.
369 * return true if class is unique in its enclosing scope.
370 * @param pos Position for error reporting.
371 * @param name The class name.
372 * @param s The enclosing scope.
373 */
374 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
375 for (Symbol sym : s.getSymbolsByName(name, NON_RECURSIVE)) {
376 if (sym.kind == TYP && sym.name != names.error) {
377 duplicateError(pos, sym);
378 return false;
379 }
380 }
381 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
382 if (sym.kind == TYP && sym.name == name && sym.name != names.error &&
383 !sym.isImplicit()) {
384 duplicateError(pos, sym);
385 return true;
386 }
387 }
388 return true;
389 }
390
391 /* *************************************************************************
392 * Class name generation
393 **************************************************************************/
394
395
396 private Map<Pair<Name, Name>, Integer> localClassNameIndexes = new HashMap<>();
397
398 /** Return name of local class.
399 * This is of the form {@code <enclClass> $ n <classname> }
400 * where
401 * enclClass is the flat name of the enclosing class,
402 * classname is the simple name of the local class
403 */
404 public Name localClassName(ClassSymbol c) {
405 Name enclFlatname = c.owner.enclClass().flatname;
406 String enclFlatnameStr = enclFlatname.toString();
407 Pair<Name, Name> key = new Pair<>(enclFlatname, c.name);
408 Integer index = localClassNameIndexes.get(key);
409 for (int i = (index == null) ? 1 : index; ; i++) {
410 Name flatname = names.fromString(enclFlatnameStr
411 + syntheticNameChar + i + c.name);
412 if (getCompiled(c.packge().modle, flatname) == null) {
413 localClassNameIndexes.put(key, i + 1);
414 return flatname;
415 }
416 }
417 }
418
419 public void clearLocalClassNameIndexes(ClassSymbol c) {
420 if (c.owner != null && c.owner.kind != NIL) {
421 localClassNameIndexes.remove(new Pair<>(
422 c.owner.enclClass().flatname, c.name));
423 }
424 }
425
426 public void newRound() {
427 compiled.clear();
428 localClassNameIndexes.clear();
429 }
430
431 public void putCompiled(ClassSymbol csym) {
432 compiled.put(Pair.of(csym.packge().modle, csym.flatname), csym);
433 }
434
435 public ClassSymbol getCompiled(ClassSymbol csym) {
436 return compiled.get(Pair.of(csym.packge().modle, csym.flatname));
437 }
438
439 public ClassSymbol getCompiled(ModuleSymbol msym, Name flatname) {
440 return compiled.get(Pair.of(msym, flatname));
441 }
442
443 public void removeCompiled(ClassSymbol csym) {
444 compiled.remove(Pair.of(csym.packge().modle, csym.flatname));
445 }
446
447 /* *************************************************************************
448 * Type Checking
449 **************************************************************************/
450
451 /**
452 * A check context is an object that can be used to perform compatibility
453 * checks - depending on the check context, meaning of 'compatibility' might
454 * vary significantly.
455 */
456 public interface CheckContext {
457 /**
458 * Is type 'found' compatible with type 'req' in given context
459 */
460 boolean compatible(Type found, Type req, Warner warn);
461 /**
462 * Report a check error
463 */
464 void report(DiagnosticPosition pos, JCDiagnostic details);
465 /**
466 * Obtain a warner for this check context
467 */
468 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req);
469
470 public InferenceContext inferenceContext();
471
472 public DeferredAttr.DeferredAttrContext deferredAttrContext();
473 }
474
475 /**
476 * This class represent a check context that is nested within another check
477 * context - useful to check sub-expressions. The default behavior simply
478 * redirects all method calls to the enclosing check context leveraging
479 * the forwarding pattern.
480 */
481 static class NestedCheckContext implements CheckContext {
482 CheckContext enclosingContext;
483
484 NestedCheckContext(CheckContext enclosingContext) {
485 this.enclosingContext = enclosingContext;
486 }
487
488 public boolean compatible(Type found, Type req, Warner warn) {
489 return enclosingContext.compatible(found, req, warn);
490 }
491
492 public void report(DiagnosticPosition pos, JCDiagnostic details) {
493 enclosingContext.report(pos, details);
494 }
495
496 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
497 return enclosingContext.checkWarner(pos, found, req);
498 }
499
500 public InferenceContext inferenceContext() {
501 return enclosingContext.inferenceContext();
502 }
503
504 public DeferredAttrContext deferredAttrContext() {
505 return enclosingContext.deferredAttrContext();
506 }
507 }
508
509 /**
510 * Check context to be used when evaluating assignment/return statements
511 */
512 CheckContext basicHandler = new CheckContext() {
513 public void report(DiagnosticPosition pos, JCDiagnostic details) {
514 log.error(pos, Errors.ProbFoundReq(details));
515 }
516 public boolean compatible(Type found, Type req, Warner warn) {
517 return types.isAssignable(found, req, warn);
518 }
519
520 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
521 return convertWarner(pos, found, req);
522 }
523
524 public InferenceContext inferenceContext() {
525 return infer.emptyContext;
526 }
527
528 public DeferredAttrContext deferredAttrContext() {
529 return deferredAttr.emptyDeferredAttrContext;
530 }
531
532 @Override
533 public String toString() {
534 return "CheckContext: basicHandler";
535 }
536 };
537
538 /** Check that a given type is assignable to a given proto-type.
539 * If it is, return the type, otherwise return errType.
540 * @param pos Position to be used for error reporting.
541 * @param found The type that was found.
542 * @param req The type that was required.
543 */
544 public Type checkType(DiagnosticPosition pos, Type found, Type req) {
545 return checkType(pos, found, req, basicHandler);
546 }
547
548 Type checkType(final DiagnosticPosition pos, final Type found, final Type req, final CheckContext checkContext) {
549 final InferenceContext inferenceContext = checkContext.inferenceContext();
550 if (inferenceContext.free(req) || inferenceContext.free(found)) {
551 inferenceContext.addFreeTypeListener(List.of(req, found),
552 solvedContext -> checkType(pos, solvedContext.asInstType(found), solvedContext.asInstType(req), checkContext));
553 }
554 if (req.hasTag(ERROR))
555 return req;
556 if (req.hasTag(NONE))
557 return found;
558 if (checkContext.compatible(found, req, checkContext.checkWarner(pos, found, req))) {
559 return found;
560 } else {
561 if (found.isNumeric() && req.isNumeric()) {
562 checkContext.report(pos, diags.fragment(Fragments.PossibleLossOfPrecision(found, req)));
563 return types.createErrorType(found);
564 }
565 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
566 return types.createErrorType(found);
567 }
568 }
569
570 /** Check that a given type can be cast to a given target type.
571 * Return the result of the cast.
572 * @param pos Position to be used for error reporting.
573 * @param found The type that is being cast.
574 * @param req The target type of the cast.
575 */
576 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
577 return checkCastable(pos, found, req, basicHandler);
578 }
579 Type checkCastable(DiagnosticPosition pos, Type found, Type req, CheckContext checkContext) {
580 if (types.isCastable(found, req, castWarner(pos, found, req))) {
581 return req;
582 } else {
583 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
584 return types.createErrorType(found);
585 }
586 }
587
588 /** Check for redundant casts (i.e. where source type is a subtype of target type)
589 * The problem should only be reported for non-292 cast
590 */
591 public void checkRedundantCast(Env<AttrContext> env, final JCTypeCast tree) {
592 if (!tree.type.isErroneous()
593 && types.isSameType(tree.expr.type, tree.clazz.type)
594 && !(ignoreAnnotatedCasts && TreeInfo.containsTypeAnnotation(tree.clazz))
595 && !is292targetTypeCast(tree)) {
596 log.warning(tree.pos(), LintWarnings.RedundantCast(tree.clazz.type));
597 }
598 }
599 //where
600 private boolean is292targetTypeCast(JCTypeCast tree) {
601 boolean is292targetTypeCast = false;
602 JCExpression expr = TreeInfo.skipParens(tree.expr);
603 if (expr.hasTag(APPLY)) {
604 JCMethodInvocation apply = (JCMethodInvocation)expr;
605 Symbol sym = TreeInfo.symbol(apply.meth);
606 is292targetTypeCast = sym != null &&
607 sym.kind == MTH &&
608 (sym.flags() & HYPOTHETICAL) != 0;
609 }
610 return is292targetTypeCast;
611 }
612
613 private static final boolean ignoreAnnotatedCasts = true;
614
615 /** Check that a type is within some bounds.
616 *
617 * Used in TypeApply to verify that, e.g., X in {@code V<X>} is a valid
618 * type argument.
619 * @param a The type that should be bounded by bs.
620 * @param bound The bound.
621 */
622 private boolean checkExtends(Type a, Type bound) {
623 if (a.isUnbound()) {
624 return true;
625 } else if (!a.hasTag(WILDCARD)) {
626 a = types.cvarUpperBound(a);
627 return types.isSubtype(a, bound);
628 } else if (a.isExtendsBound()) {
629 return types.isCastable(bound, types.wildUpperBound(a), types.noWarnings);
630 } else if (a.isSuperBound()) {
631 return !types.notSoftSubtype(types.wildLowerBound(a), bound);
632 }
633 return true;
634 }
635
636 /** Check that type is different from 'void'.
637 * @param pos Position to be used for error reporting.
638 * @param t The type to be checked.
639 */
640 Type checkNonVoid(DiagnosticPosition pos, Type t) {
641 if (t.hasTag(VOID)) {
642 log.error(pos, Errors.VoidNotAllowedHere);
643 return types.createErrorType(t);
644 } else {
645 return t;
646 }
647 }
648
649 Type checkClassOrArrayType(DiagnosticPosition pos, Type t) {
650 if (!t.hasTag(CLASS) && !t.hasTag(ARRAY) && !t.hasTag(ERROR)) {
651 return typeTagError(pos,
652 diags.fragment(Fragments.TypeReqClassArray),
653 t);
654 } else {
655 return t;
656 }
657 }
658
659 /** Check that type is a class or interface type.
660 * @param pos Position to be used for error reporting.
661 * @param t The type to be checked.
662 */
663 Type checkClassType(DiagnosticPosition pos, Type t) {
664 if (!t.hasTag(CLASS) && !t.hasTag(ERROR)) {
665 return typeTagError(pos,
666 diags.fragment(Fragments.TypeReqClass),
667 t);
668 } else {
669 return t;
670 }
671 }
672 //where
673 private Object asTypeParam(Type t) {
674 return (t.hasTag(TYPEVAR))
675 ? diags.fragment(Fragments.TypeParameter(t))
676 : t;
677 }
678
679 /** Check that type is a valid qualifier for a constructor reference expression
680 */
681 Type checkConstructorRefType(DiagnosticPosition pos, Type t) {
682 t = checkClassOrArrayType(pos, t);
683 if (t.hasTag(CLASS)) {
684 if ((t.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
685 log.error(pos, Errors.AbstractCantBeInstantiated(t.tsym));
686 t = types.createErrorType(t);
687 } else if ((t.tsym.flags() & ENUM) != 0) {
688 log.error(pos, Errors.EnumCantBeInstantiated);
689 t = types.createErrorType(t);
690 } else {
691 t = checkClassType(pos, t, true);
692 }
693 } else if (t.hasTag(ARRAY)) {
694 if (!types.isReifiable(((ArrayType)t).elemtype)) {
695 log.error(pos, Errors.GenericArrayCreation);
696 t = types.createErrorType(t);
697 }
698 }
699 return t;
700 }
701
702 /** Check that type is a class or interface type.
703 * @param pos Position to be used for error reporting.
704 * @param t The type to be checked.
705 * @param noBounds True if type bounds are illegal here.
706 */
707 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
708 t = checkClassType(pos, t);
709 if (noBounds && t.isParameterized()) {
710 List<Type> args = t.getTypeArguments();
711 while (args.nonEmpty()) {
712 if (args.head.hasTag(WILDCARD))
713 return typeTagError(pos,
714 diags.fragment(Fragments.TypeReqExact),
715 args.head);
716 args = args.tail;
717 }
718 }
719 return t;
720 }
721
722 /** Check that type is a reference type, i.e. a class, interface or array type
723 * or a type variable.
724 * @param pos Position to be used for error reporting.
725 * @param t The type to be checked.
726 */
727 Type checkRefType(DiagnosticPosition pos, Type t) {
728 if (t.isReference())
729 return t;
730 else
731 return typeTagError(pos,
732 diags.fragment(Fragments.TypeReqRef),
733 t);
734 }
735
736 /** Check that type is an identity type, i.e. not a value type.
737 * When not discernible statically, give it the benefit of doubt
738 * and defer to runtime.
739 *
740 * @param pos Position to be used for error reporting.
741 * @param t The type to be checked.
742 */
743 boolean checkIdentityType(DiagnosticPosition pos, Type t) {
744 if (t.hasTag(TYPEVAR)) {
745 t = types.skipTypeVars(t, false);
746 }
747 if (t.isIntersection()) {
748 IntersectionClassType ict = (IntersectionClassType)t;
749 boolean result = true;
750 for (Type component : ict.getExplicitComponents()) {
751 result &= checkIdentityType(pos, component);
752 }
753 return result;
754 }
755 if (t.isPrimitive() || (t.isValueClass() && !t.tsym.isAbstract())) {
756 typeTagError(pos, diags.fragment(Fragments.TypeReqIdentity), t);
757 return false;
758 }
759 return true;
760 }
761
762 /** Check that each type is a reference type, i.e. a class, interface or array type
763 * or a type variable.
764 * @param trees Original trees, used for error reporting.
765 * @param types The types to be checked.
766 */
767 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
768 List<JCExpression> tl = trees;
769 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
770 l.head = checkRefType(tl.head.pos(), l.head);
771 tl = tl.tail;
772 }
773 return types;
774 }
775
776 /** Check that type is a null or reference type.
777 * @param pos Position to be used for error reporting.
778 * @param t The type to be checked.
779 */
780 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
781 if (t.isReference() || t.hasTag(BOT))
782 return t;
783 else
784 return typeTagError(pos,
785 diags.fragment(Fragments.TypeReqRef),
786 t);
787 }
788
789 /** Check that flag set does not contain elements of two conflicting sets. s
790 * Return true if it doesn't.
791 * @param pos Position to be used for error reporting.
792 * @param flags The set of flags to be checked.
793 * @param set1 Conflicting flags set #1.
794 * @param set2 Conflicting flags set #2.
795 */
796 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
797 if ((flags & set1) != 0 && (flags & set2) != 0) {
798 log.error(pos,
799 Errors.IllegalCombinationOfModifiers(asFlagSet(TreeInfo.firstFlag(flags & set1)),
800 asFlagSet(TreeInfo.firstFlag(flags & set2))));
801 return false;
802 } else
803 return true;
804 }
805
806 /** Check that usage of diamond operator is correct (i.e. diamond should not
807 * be used with non-generic classes or in anonymous class creation expressions)
808 */
809 Type checkDiamond(JCNewClass tree, Type t) {
810 if (!TreeInfo.isDiamond(tree) ||
811 t.isErroneous()) {
812 return checkClassType(tree.clazz.pos(), t, true);
813 } else {
814 if (tree.def != null && !Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.allowedInSource(source)) {
815 log.error(DiagnosticFlag.SOURCE_LEVEL, tree.clazz.pos(),
816 Errors.CantApplyDiamond1(t, Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.fragment(source.name)));
817 }
818 if (t.tsym.type.getTypeArguments().isEmpty()) {
819 log.error(tree.clazz.pos(),
820 Errors.CantApplyDiamond1(t,
821 Fragments.DiamondNonGeneric(t)));
822 return types.createErrorType(t);
823 } else if (tree.typeargs != null &&
824 tree.typeargs.nonEmpty()) {
825 log.error(tree.clazz.pos(),
826 Errors.CantApplyDiamond1(t,
827 Fragments.DiamondAndExplicitParams(t)));
828 return types.createErrorType(t);
829 } else {
830 return t;
831 }
832 }
833 }
834
835 /** Check that the type inferred using the diamond operator does not contain
836 * non-denotable types such as captured types or intersection types.
837 * @param t the type inferred using the diamond operator
838 * @return the (possibly empty) list of non-denotable types.
839 */
840 List<Type> checkDiamondDenotable(ClassType t) {
841 ListBuffer<Type> buf = new ListBuffer<>();
842 for (Type arg : t.allparams()) {
843 if (!checkDenotable(arg)) {
844 buf.append(arg);
845 }
846 }
847 return buf.toList();
848 }
849
850 public boolean checkDenotable(Type t) {
851 return denotableChecker.visit(t, null);
852 }
853 // where
854
855 /** diamondTypeChecker: A type visitor that descends down the given type looking for non-denotable
856 * types. The visit methods return false as soon as a non-denotable type is encountered and true
857 * otherwise.
858 */
859 private static final Types.SimpleVisitor<Boolean, Void> denotableChecker = new Types.SimpleVisitor<Boolean, Void>() {
860 @Override
861 public Boolean visitType(Type t, Void s) {
862 return true;
863 }
864 @Override
865 public Boolean visitClassType(ClassType t, Void s) {
866 if (t.isUnion() || t.isIntersection()) {
867 return false;
868 }
869 for (Type targ : t.allparams()) {
870 if (!visit(targ, s)) {
871 return false;
872 }
873 }
874 return true;
875 }
876
877 @Override
878 public Boolean visitTypeVar(TypeVar t, Void s) {
879 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
880 (i.e cannot have been produced by inference (18.4))
881 */
882 return (t.tsym.flags() & SYNTHETIC) == 0;
883 }
884
885 @Override
886 public Boolean visitCapturedType(CapturedType t, Void s) {
887 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
888 (i.e cannot have been produced by capture conversion (5.1.10))
889 */
890 return false;
891 }
892
893 @Override
894 public Boolean visitArrayType(ArrayType t, Void s) {
895 return visit(t.elemtype, s);
896 }
897
898 @Override
899 public Boolean visitWildcardType(WildcardType t, Void s) {
900 return visit(t.type, s);
901 }
902 };
903
904 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
905 MethodSymbol m = tree.sym;
906 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
907 Type varargElemType = null;
908 if (m.isVarArgs()) {
909 varargElemType = types.elemtype(tree.params.last().type);
910 }
911 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
912 if (varargElemType != null) {
913 JCDiagnostic msg = Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ?
914 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargs(m)) :
915 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargsFinalOnly(m));
916 log.error(tree,
917 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
918 msg));
919 } else {
920 log.error(tree,
921 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
922 Fragments.VarargsTrustmeOnNonVarargsMeth(m)));
923 }
924 } else if (hasTrustMeAnno && varargElemType != null &&
925 types.isReifiable(varargElemType)) {
926 log.warning(tree.pos(), LintWarnings.VarargsRedundantTrustmeAnno(
927 syms.trustMeType.tsym,
928 diags.fragment(Fragments.VarargsTrustmeOnReifiableVarargs(varargElemType))));
929 }
930 else if (!hasTrustMeAnno && varargElemType != null &&
931 !types.isReifiable(varargElemType)) {
932 warnUnchecked(tree.params.last().pos(), LintWarnings.UncheckedVarargsNonReifiableType(varargElemType));
933 }
934 }
935 //where
936 private boolean isTrustMeAllowedOnMethod(Symbol s) {
937 return (s.flags() & VARARGS) != 0 &&
938 (s.isConstructor() ||
939 (s.flags() & (STATIC | FINAL |
940 (Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ? PRIVATE : 0) )) != 0);
941 }
942
943 Type checkLocalVarType(DiagnosticPosition pos, Type t, Name name) {
944 //check that resulting type is not the null type
945 if (t.hasTag(BOT)) {
946 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferNull));
947 return types.createErrorType(t);
948 } else if (t.hasTag(VOID)) {
949 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferVoid));
950 return types.createErrorType(t);
951 }
952
953 //upward project the initializer type
954 return types.upward(t, types.captures(t)).baseType();
955 }
956
957 Type checkMethod(final Type mtype,
958 final Symbol sym,
959 final Env<AttrContext> env,
960 final List<JCExpression> argtrees,
961 final List<Type> argtypes,
962 final boolean useVarargs,
963 InferenceContext inferenceContext) {
964 // System.out.println("call : " + env.tree);
965 // System.out.println("method : " + owntype);
966 // System.out.println("actuals: " + argtypes);
967 if (inferenceContext.free(mtype)) {
968 inferenceContext.addFreeTypeListener(List.of(mtype),
969 solvedContext -> checkMethod(solvedContext.asInstType(mtype), sym, env, argtrees, argtypes, useVarargs, solvedContext));
970 return mtype;
971 }
972 Type owntype = mtype;
973 List<Type> formals = owntype.getParameterTypes();
974 List<Type> nonInferred = sym.type.getParameterTypes();
975 if (nonInferred.length() != formals.length()) nonInferred = formals;
976 Type last = useVarargs ? formals.last() : null;
977 if (sym.name == names.init && sym.owner == syms.enumSym) {
978 formals = formals.tail.tail;
979 nonInferred = nonInferred.tail.tail;
980 }
981 if ((sym.flags() & ANONCONSTR_BASED) != 0) {
982 formals = formals.tail;
983 nonInferred = nonInferred.tail;
984 }
985 List<JCExpression> args = argtrees;
986 if (args != null) {
987 //this is null when type-checking a method reference
988 while (formals.head != last) {
989 JCTree arg = args.head;
990 Warner warn = convertWarner(arg.pos(), arg.type, nonInferred.head);
991 assertConvertible(arg, arg.type, formals.head, warn);
992 args = args.tail;
993 formals = formals.tail;
994 nonInferred = nonInferred.tail;
995 }
996 if (useVarargs) {
997 Type varArg = types.elemtype(last);
998 while (args.tail != null) {
999 JCTree arg = args.head;
1000 Warner warn = convertWarner(arg.pos(), arg.type, varArg);
1001 assertConvertible(arg, arg.type, varArg, warn);
1002 args = args.tail;
1003 }
1004 } else if ((sym.flags() & (VARARGS | SIGNATURE_POLYMORPHIC)) == VARARGS) {
1005 // non-varargs call to varargs method
1006 Type varParam = owntype.getParameterTypes().last();
1007 Type lastArg = argtypes.last();
1008 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
1009 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
1010 log.warning(argtrees.last().pos(),
1011 Warnings.InexactNonVarargsCall(types.elemtype(varParam),varParam));
1012 }
1013 }
1014 if (useVarargs) {
1015 Type argtype = owntype.getParameterTypes().last();
1016 if (!types.isReifiable(argtype) &&
1017 (sym.baseSymbol().attribute(syms.trustMeType.tsym) == null ||
1018 !isTrustMeAllowedOnMethod(sym))) {
1019 warnUnchecked(env.tree.pos(), LintWarnings.UncheckedGenericArrayCreation(argtype));
1020 }
1021 TreeInfo.setVarargsElement(env.tree, types.elemtype(argtype));
1022 }
1023 return owntype;
1024 }
1025 //where
1026 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
1027 if (types.isConvertible(actual, formal, warn))
1028 return;
1029
1030 if (formal.isCompound()
1031 && types.isSubtype(actual, types.supertype(formal))
1032 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
1033 return;
1034 }
1035
1036 /**
1037 * Check that type 't' is a valid instantiation of a generic class
1038 * (see JLS 4.5)
1039 *
1040 * @param t class type to be checked
1041 * @return true if 't' is well-formed
1042 */
1043 public boolean checkValidGenericType(Type t) {
1044 return firstIncompatibleTypeArg(t) == null;
1045 }
1046 //WHERE
1047 private Type firstIncompatibleTypeArg(Type type) {
1048 List<Type> formals = type.tsym.type.allparams();
1049 List<Type> actuals = type.allparams();
1050 List<Type> args = type.getTypeArguments();
1051 List<Type> forms = type.tsym.type.getTypeArguments();
1052 ListBuffer<Type> bounds_buf = new ListBuffer<>();
1053
1054 // For matching pairs of actual argument types `a' and
1055 // formal type parameters with declared bound `b' ...
1056 while (args.nonEmpty() && forms.nonEmpty()) {
1057 // exact type arguments needs to know their
1058 // bounds (for upper and lower bound
1059 // calculations). So we create new bounds where
1060 // type-parameters are replaced with actuals argument types.
1061 bounds_buf.append(types.subst(forms.head.getUpperBound(), formals, actuals));
1062 args = args.tail;
1063 forms = forms.tail;
1064 }
1065
1066 args = type.getTypeArguments();
1067 List<Type> tvars_cap = types.substBounds(formals,
1068 formals,
1069 types.capture(type).allparams());
1070 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
1071 // Let the actual arguments know their bound
1072 args.head.withTypeVar((TypeVar)tvars_cap.head);
1073 args = args.tail;
1074 tvars_cap = tvars_cap.tail;
1075 }
1076
1077 args = type.getTypeArguments();
1078 List<Type> bounds = bounds_buf.toList();
1079
1080 while (args.nonEmpty() && bounds.nonEmpty()) {
1081 Type actual = args.head;
1082 if (!isTypeArgErroneous(actual) &&
1083 !bounds.head.isErroneous() &&
1084 !checkExtends(actual, bounds.head)) {
1085 return args.head;
1086 }
1087 args = args.tail;
1088 bounds = bounds.tail;
1089 }
1090
1091 args = type.getTypeArguments();
1092 bounds = bounds_buf.toList();
1093
1094 for (Type arg : types.capture(type).getTypeArguments()) {
1095 if (arg.hasTag(TYPEVAR) &&
1096 arg.getUpperBound().isErroneous() &&
1097 !bounds.head.isErroneous() &&
1098 !isTypeArgErroneous(args.head)) {
1099 return args.head;
1100 }
1101 bounds = bounds.tail;
1102 args = args.tail;
1103 }
1104
1105 return null;
1106 }
1107 //where
1108 boolean isTypeArgErroneous(Type t) {
1109 return isTypeArgErroneous.visit(t);
1110 }
1111
1112 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() {
1113 public Boolean visitType(Type t, Void s) {
1114 return t.isErroneous();
1115 }
1116 @Override
1117 public Boolean visitTypeVar(TypeVar t, Void s) {
1118 return visit(t.getUpperBound());
1119 }
1120 @Override
1121 public Boolean visitCapturedType(CapturedType t, Void s) {
1122 return visit(t.getUpperBound()) ||
1123 visit(t.getLowerBound());
1124 }
1125 @Override
1126 public Boolean visitWildcardType(WildcardType t, Void s) {
1127 return visit(t.type);
1128 }
1129 };
1130
1131 /** Check that given modifiers are legal for given symbol and
1132 * return modifiers together with any implicit modifiers for that symbol.
1133 * Warning: we can't use flags() here since this method
1134 * is called during class enter, when flags() would cause a premature
1135 * completion.
1136 * @param flags The set of modifiers given in a definition.
1137 * @param sym The defined symbol.
1138 * @param tree The declaration
1139 */
1140 long checkFlags(long flags, Symbol sym, JCTree tree) {
1141 final DiagnosticPosition pos = tree.pos();
1142 long mask;
1143 long implicit = 0;
1144
1145 switch (sym.kind) {
1146 case VAR:
1147 if (TreeInfo.isReceiverParam(tree))
1148 mask = ReceiverParamFlags;
1149 else if (sym.owner.kind != TYP)
1150 mask = LocalVarFlags;
1151 else if ((sym.owner.flags_field & INTERFACE) != 0)
1152 mask = implicit = InterfaceVarFlags;
1153 else {
1154 boolean isInstanceField = (flags & STATIC) == 0;
1155 boolean isInstanceFieldOfValueClass = isInstanceField && sym.owner.type.isValueClass();
1156 boolean isRecordField = isInstanceField && (sym.owner.flags_field & RECORD) != 0;
1157 if (allowValueClasses && (isInstanceFieldOfValueClass || isRecordField)) {
1158 implicit |= FINAL | STRICT;
1159 preview.markUsesPreview(pos); // STRICT_INIT is a preview VM feature
1160 mask = ValueFieldFlags;
1161 } else {
1162 mask = VarFlags;
1163 }
1164 }
1165 break;
1166 case MTH:
1167 if (sym.name == names.init) {
1168 if ((sym.owner.flags_field & ENUM) != 0) {
1169 // enum constructors cannot be declared public or
1170 // protected and must be implicitly or explicitly
1171 // private
1172 implicit = PRIVATE;
1173 mask = PRIVATE;
1174 } else
1175 mask = ConstructorFlags;
1176 } else if ((sym.owner.flags_field & INTERFACE) != 0) {
1177 if ((sym.owner.flags_field & ANNOTATION) != 0) {
1178 mask = AnnotationTypeElementMask;
1179 implicit = PUBLIC | ABSTRACT;
1180 } else if ((flags & (DEFAULT | STATIC | PRIVATE)) != 0) {
1181 mask = InterfaceMethodMask;
1182 implicit = (flags & PRIVATE) != 0 ? 0 : PUBLIC;
1183 if ((flags & DEFAULT) != 0) {
1184 implicit |= ABSTRACT;
1185 }
1186 } else {
1187 mask = implicit = InterfaceMethodFlags;
1188 }
1189 } else if ((sym.owner.flags_field & RECORD) != 0) {
1190 mask = ((sym.owner.flags_field & VALUE_CLASS) != 0 && (flags & Flags.STATIC) == 0) ?
1191 RecordMethodFlags & ~SYNCHRONIZED : RecordMethodFlags;
1192 } else {
1193 // value objects do not have an associated monitor/lock
1194 mask = ((sym.owner.flags_field & VALUE_CLASS) != 0 && (flags & Flags.STATIC) == 0) ?
1195 MethodFlags & ~SYNCHRONIZED : MethodFlags;
1196 }
1197 if ((flags & STRICTFP) != 0) {
1198 log.warning(tree.pos(), LintWarnings.Strictfp);
1199 }
1200 // Imply STRICTFP if owner has STRICTFP set.
1201 if (((flags|implicit) & Flags.ABSTRACT) == 0 ||
1202 ((flags) & Flags.DEFAULT) != 0)
1203 implicit |= sym.owner.flags_field & STRICTFP;
1204 break;
1205 case TYP:
1206 if (sym.owner.kind.matches(KindSelector.VAL_MTH) ||
1207 (sym.isDirectlyOrIndirectlyLocal() && (flags & ANNOTATION) != 0)) {
1208 boolean implicitlyStatic = !sym.isAnonymous() &&
1209 ((flags & RECORD) != 0 || (flags & ENUM) != 0 || (flags & INTERFACE) != 0);
1210 boolean staticOrImplicitlyStatic = (flags & STATIC) != 0 || implicitlyStatic;
1211 // local statics are allowed only if records are allowed too
1212 mask = staticOrImplicitlyStatic && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedStaticLocalClassFlags : ExtendedLocalClassFlags;
1213 implicit = implicitlyStatic ? STATIC : implicit;
1214 } else if (sym.owner.kind == TYP) {
1215 // statics in inner classes are allowed only if records are allowed too
1216 mask = ((flags & STATIC) != 0) && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedMemberStaticClassFlags : ExtendedMemberClassFlags;
1217 if (sym.owner.owner.kind == PCK ||
1218 (sym.owner.flags_field & STATIC) != 0) {
1219 mask |= STATIC;
1220 } else if (!allowRecords && ((flags & ENUM) != 0 || (flags & RECORD) != 0)) {
1221 log.error(pos, Errors.StaticDeclarationNotAllowedInInnerClasses);
1222 }
1223 // Nested interfaces and enums are always STATIC (Spec ???)
1224 if ((flags & (INTERFACE | ENUM | RECORD)) != 0 ) implicit = STATIC;
1225 } else {
1226 mask = ExtendedClassFlags;
1227 }
1228 if ((flags & (VALUE_CLASS | SEALED | ABSTRACT)) == (VALUE_CLASS | SEALED) ||
1229 (flags & (VALUE_CLASS | NON_SEALED | ABSTRACT)) == (VALUE_CLASS | NON_SEALED)) {
1230 log.error(pos, Errors.NonAbstractValueClassCantBeSealedOrNonSealed);
1231 }
1232 // Interfaces are always ABSTRACT
1233 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
1234
1235 if ((flags & (INTERFACE | VALUE_CLASS)) == 0) {
1236 implicit |= IDENTITY_TYPE;
1237 }
1238
1239 if ((flags & ENUM) != 0) {
1240 // enums can't be declared abstract, final, sealed or non-sealed or value
1241 mask &= ~(ABSTRACT | FINAL | SEALED | NON_SEALED | VALUE_CLASS);
1242 implicit |= implicitEnumFinalFlag(tree);
1243 }
1244 if ((flags & RECORD) != 0) {
1245 // records can't be declared abstract
1246 mask &= ~ABSTRACT;
1247 implicit |= FINAL;
1248 }
1249 if ((flags & STRICTFP) != 0) {
1250 log.warning(tree.pos(), LintWarnings.Strictfp);
1251 }
1252 // Imply STRICTFP if owner has STRICTFP set.
1253 implicit |= sym.owner.flags_field & STRICTFP;
1254
1255 // concrete value classes are implicitly final
1256 if ((flags & (ABSTRACT | INTERFACE | VALUE_CLASS)) == VALUE_CLASS) {
1257 implicit |= FINAL;
1258 }
1259 break;
1260 default:
1261 throw new AssertionError();
1262 }
1263 long illegal = flags & ExtendedStandardFlags & ~mask;
1264 if (illegal != 0) {
1265 if ((illegal & INTERFACE) != 0) {
1266 log.error(pos, ((flags & ANNOTATION) != 0) ? Errors.AnnotationDeclNotAllowedHere : Errors.IntfNotAllowedHere);
1267 mask |= INTERFACE;
1268 }
1269 else {
1270 log.error(pos,
1271 Errors.ModNotAllowedHere(asFlagSet(illegal)));
1272 }
1273 } else if ((sym.kind == TYP ||
1274 // ISSUE: Disallowing abstract&private is no longer appropriate
1275 // in the presence of inner classes. Should it be deleted here?
1276 checkDisjoint(pos, flags,
1277 ABSTRACT,
1278 PRIVATE | STATIC | DEFAULT))
1279 &&
1280 checkDisjoint(pos, flags,
1281 STATIC | PRIVATE,
1282 DEFAULT)
1283 &&
1284 checkDisjoint(pos, flags,
1285 ABSTRACT | INTERFACE,
1286 FINAL | NATIVE | SYNCHRONIZED)
1287 &&
1288 checkDisjoint(pos, flags,
1289 PUBLIC,
1290 PRIVATE | PROTECTED)
1291 &&
1292 checkDisjoint(pos, flags,
1293 PRIVATE,
1294 PUBLIC | PROTECTED)
1295 &&
1296 // we are using `implicit` here as instance fields of value classes are implicitly final
1297 checkDisjoint(pos, flags | implicit,
1298 FINAL,
1299 VOLATILE)
1300 &&
1301 (sym.kind == TYP ||
1302 checkDisjoint(pos, flags,
1303 ABSTRACT | NATIVE,
1304 STRICTFP))
1305 && checkDisjoint(pos, flags,
1306 FINAL,
1307 SEALED | NON_SEALED)
1308 && checkDisjoint(pos, flags,
1309 SEALED,
1310 FINAL | NON_SEALED)
1311 && checkDisjoint(pos, flags,
1312 SEALED,
1313 ANNOTATION)
1314 && checkDisjoint(pos, flags,
1315 VALUE_CLASS,
1316 ANNOTATION)
1317 && checkDisjoint(pos, flags,
1318 VALUE_CLASS,
1319 INTERFACE) ) {
1320 // skip
1321 }
1322 return flags & (mask | ~ExtendedStandardFlags) | implicit;
1323 }
1324
1325 /** Determine if this enum should be implicitly final.
1326 *
1327 * If the enum has no specialized enum constants, it is final.
1328 *
1329 * If the enum does have specialized enum constants, it is
1330 * <i>not</i> final.
1331 */
1332 private long implicitEnumFinalFlag(JCTree tree) {
1333 if (!tree.hasTag(CLASSDEF)) return 0;
1334 class SpecialTreeVisitor extends JCTree.Visitor {
1335 boolean specialized;
1336 SpecialTreeVisitor() {
1337 this.specialized = false;
1338 }
1339
1340 @Override
1341 public void visitTree(JCTree tree) { /* no-op */ }
1342
1343 @Override
1344 public void visitVarDef(JCVariableDecl tree) {
1345 if ((tree.mods.flags & ENUM) != 0) {
1346 if (tree.init instanceof JCNewClass newClass && newClass.def != null) {
1347 specialized = true;
1348 }
1349 }
1350 }
1351 }
1352
1353 SpecialTreeVisitor sts = new SpecialTreeVisitor();
1354 JCClassDecl cdef = (JCClassDecl) tree;
1355 for (JCTree defs: cdef.defs) {
1356 defs.accept(sts);
1357 if (sts.specialized) return allowSealed ? SEALED : 0;
1358 }
1359 return FINAL;
1360 }
1361
1362 /* *************************************************************************
1363 * Type Validation
1364 **************************************************************************/
1365
1366 /** Validate a type expression. That is,
1367 * check that all type arguments of a parametric type are within
1368 * their bounds. This must be done in a second phase after type attribution
1369 * since a class might have a subclass as type parameter bound. E.g:
1370 *
1371 * <pre>{@code
1372 * class B<A extends C> { ... }
1373 * class C extends B<C> { ... }
1374 * }</pre>
1375 *
1376 * and we can't make sure that the bound is already attributed because
1377 * of possible cycles.
1378 *
1379 * Visitor method: Validate a type expression, if it is not null, catching
1380 * and reporting any completion failures.
1381 */
1382 void validate(JCTree tree, Env<AttrContext> env) {
1383 validate(tree, env, true);
1384 }
1385 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1386 new Validator(env).validateTree(tree, checkRaw, true);
1387 }
1388
1389 /** Visitor method: Validate a list of type expressions.
1390 */
1391 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1392 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1393 validate(l.head, env);
1394 }
1395
1396 /** A visitor class for type validation.
1397 */
1398 class Validator extends JCTree.Visitor {
1399
1400 boolean checkRaw;
1401 boolean isOuter;
1402 Env<AttrContext> env;
1403
1404 Validator(Env<AttrContext> env) {
1405 this.env = env;
1406 }
1407
1408 @Override
1409 public void visitTypeArray(JCArrayTypeTree tree) {
1410 validateTree(tree.elemtype, checkRaw, isOuter);
1411 }
1412
1413 @Override
1414 public void visitTypeApply(JCTypeApply tree) {
1415 if (tree.type.hasTag(CLASS)) {
1416 List<JCExpression> args = tree.arguments;
1417 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1418
1419 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1420 if (incompatibleArg != null) {
1421 for (JCTree arg : tree.arguments) {
1422 if (arg.type == incompatibleArg) {
1423 log.error(arg, Errors.NotWithinBounds(incompatibleArg, forms.head));
1424 }
1425 forms = forms.tail;
1426 }
1427 }
1428
1429 forms = tree.type.tsym.type.getTypeArguments();
1430
1431 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1432
1433 // For matching pairs of actual argument types `a' and
1434 // formal type parameters with declared bound `b' ...
1435 while (args.nonEmpty() && forms.nonEmpty()) {
1436 validateTree(args.head,
1437 !(isOuter && is_java_lang_Class),
1438 false);
1439 args = args.tail;
1440 forms = forms.tail;
1441 }
1442
1443 // Check that this type is either fully parameterized, or
1444 // not parameterized at all.
1445 if (tree.type.getEnclosingType().isRaw())
1446 log.error(tree.pos(), Errors.ImproperlyFormedTypeInnerRawParam);
1447 if (tree.clazz.hasTag(SELECT))
1448 visitSelectInternal((JCFieldAccess)tree.clazz);
1449 }
1450 }
1451
1452 @Override
1453 public void visitTypeParameter(JCTypeParameter tree) {
1454 validateTrees(tree.bounds, true, isOuter);
1455 checkClassBounds(tree.pos(), tree.type);
1456 }
1457
1458 @Override
1459 public void visitWildcard(JCWildcard tree) {
1460 if (tree.inner != null)
1461 validateTree(tree.inner, true, isOuter);
1462 }
1463
1464 @Override
1465 public void visitSelect(JCFieldAccess tree) {
1466 if (tree.type.hasTag(CLASS)) {
1467 visitSelectInternal(tree);
1468
1469 // Check that this type is either fully parameterized, or
1470 // not parameterized at all.
1471 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1472 log.error(tree.pos(), Errors.ImproperlyFormedTypeParamMissing);
1473 }
1474 }
1475
1476 public void visitSelectInternal(JCFieldAccess tree) {
1477 if (tree.type.tsym.isStatic() &&
1478 tree.selected.type.isParameterized()) {
1479 // The enclosing type is not a class, so we are
1480 // looking at a static member type. However, the
1481 // qualifying expression is parameterized.
1482 log.error(tree.pos(), Errors.CantSelectStaticClassFromParamType);
1483 } else {
1484 // otherwise validate the rest of the expression
1485 tree.selected.accept(this);
1486 }
1487 }
1488
1489 @Override
1490 public void visitAnnotatedType(JCAnnotatedType tree) {
1491 tree.underlyingType.accept(this);
1492 }
1493
1494 @Override
1495 public void visitTypeIdent(JCPrimitiveTypeTree that) {
1496 if (that.type.hasTag(TypeTag.VOID)) {
1497 log.error(that.pos(), Errors.VoidNotAllowedHere);
1498 }
1499 super.visitTypeIdent(that);
1500 }
1501
1502 /** Default visitor method: do nothing.
1503 */
1504 @Override
1505 public void visitTree(JCTree tree) {
1506 }
1507
1508 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1509 if (tree != null) {
1510 boolean prevCheckRaw = this.checkRaw;
1511 this.checkRaw = checkRaw;
1512 this.isOuter = isOuter;
1513
1514 try {
1515 tree.accept(this);
1516 if (checkRaw)
1517 checkRaw(tree, env);
1518 } catch (CompletionFailure ex) {
1519 completionError(tree.pos(), ex);
1520 } finally {
1521 this.checkRaw = prevCheckRaw;
1522 }
1523 }
1524 }
1525
1526 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1527 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1528 validateTree(l.head, checkRaw, isOuter);
1529 }
1530 }
1531
1532 void checkRaw(JCTree tree, Env<AttrContext> env) {
1533 if (tree.type.hasTag(CLASS) &&
1534 !TreeInfo.isDiamond(tree) &&
1535 !withinAnonConstr(env) &&
1536 tree.type.isRaw()) {
1537 log.warning(tree.pos(), LintWarnings.RawClassUse(tree.type, tree.type.tsym.type));
1538 }
1539 }
1540 //where
1541 private boolean withinAnonConstr(Env<AttrContext> env) {
1542 return env.enclClass.name.isEmpty() &&
1543 env.enclMethod != null && env.enclMethod.name == names.init;
1544 }
1545
1546 /* *************************************************************************
1547 * Exception checking
1548 **************************************************************************/
1549
1550 /* The following methods treat classes as sets that contain
1551 * the class itself and all their subclasses
1552 */
1553
1554 /** Is given type a subtype of some of the types in given list?
1555 */
1556 boolean subset(Type t, List<Type> ts) {
1557 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1558 if (types.isSubtype(t, l.head)) return true;
1559 return false;
1560 }
1561
1562 /** Is given type a subtype or supertype of
1563 * some of the types in given list?
1564 */
1565 boolean intersects(Type t, List<Type> ts) {
1566 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1567 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1568 return false;
1569 }
1570
1571 /** Add type set to given type list, unless it is a subclass of some class
1572 * in the list.
1573 */
1574 List<Type> incl(Type t, List<Type> ts) {
1575 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1576 }
1577
1578 /** Remove type set from type set list.
1579 */
1580 List<Type> excl(Type t, List<Type> ts) {
1581 if (ts.isEmpty()) {
1582 return ts;
1583 } else {
1584 List<Type> ts1 = excl(t, ts.tail);
1585 if (types.isSubtype(ts.head, t)) return ts1;
1586 else if (ts1 == ts.tail) return ts;
1587 else return ts1.prepend(ts.head);
1588 }
1589 }
1590
1591 /** Form the union of two type set lists.
1592 */
1593 List<Type> union(List<Type> ts1, List<Type> ts2) {
1594 List<Type> ts = ts1;
1595 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1596 ts = incl(l.head, ts);
1597 return ts;
1598 }
1599
1600 /** Form the difference of two type lists.
1601 */
1602 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1603 List<Type> ts = ts1;
1604 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1605 ts = excl(l.head, ts);
1606 return ts;
1607 }
1608
1609 /** Form the intersection of two type lists.
1610 */
1611 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1612 List<Type> ts = List.nil();
1613 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1614 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1615 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1616 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1617 return ts;
1618 }
1619
1620 /** Is exc an exception symbol that need not be declared?
1621 */
1622 boolean isUnchecked(ClassSymbol exc) {
1623 return
1624 exc.kind == ERR ||
1625 exc.isSubClass(syms.errorType.tsym, types) ||
1626 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1627 }
1628
1629 /** Is exc an exception type that need not be declared?
1630 */
1631 boolean isUnchecked(Type exc) {
1632 return
1633 (exc.hasTag(TYPEVAR)) ? isUnchecked(types.supertype(exc)) :
1634 (exc.hasTag(CLASS)) ? isUnchecked((ClassSymbol)exc.tsym) :
1635 exc.hasTag(BOT);
1636 }
1637
1638 boolean isChecked(Type exc) {
1639 return !isUnchecked(exc);
1640 }
1641
1642 /** Same, but handling completion failures.
1643 */
1644 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1645 try {
1646 return isUnchecked(exc);
1647 } catch (CompletionFailure ex) {
1648 completionError(pos, ex);
1649 return true;
1650 }
1651 }
1652
1653 /** Is exc handled by given exception list?
1654 */
1655 boolean isHandled(Type exc, List<Type> handled) {
1656 return isUnchecked(exc) || subset(exc, handled);
1657 }
1658
1659 /** Return all exceptions in thrown list that are not in handled list.
1660 * @param thrown The list of thrown exceptions.
1661 * @param handled The list of handled exceptions.
1662 */
1663 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1664 List<Type> unhandled = List.nil();
1665 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1666 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1667 return unhandled;
1668 }
1669
1670 /* *************************************************************************
1671 * Overriding/Implementation checking
1672 **************************************************************************/
1673
1674 /** The level of access protection given by a flag set,
1675 * where PRIVATE is highest and PUBLIC is lowest.
1676 */
1677 static int protection(long flags) {
1678 switch ((short)(flags & AccessFlags)) {
1679 case PRIVATE: return 3;
1680 case PROTECTED: return 1;
1681 default:
1682 case PUBLIC: return 0;
1683 case 0: return 2;
1684 }
1685 }
1686
1687 /** A customized "cannot override" error message.
1688 * @param m The overriding method.
1689 * @param other The overridden method.
1690 * @return An internationalized string.
1691 */
1692 Fragment cannotOverride(MethodSymbol m, MethodSymbol other) {
1693 Symbol mloc = m.location();
1694 Symbol oloc = other.location();
1695
1696 if ((other.owner.flags() & INTERFACE) == 0)
1697 return Fragments.CantOverride(m, mloc, other, oloc);
1698 else if ((m.owner.flags() & INTERFACE) == 0)
1699 return Fragments.CantImplement(m, mloc, other, oloc);
1700 else
1701 return Fragments.ClashesWith(m, mloc, other, oloc);
1702 }
1703
1704 /** A customized "override" warning message.
1705 * @param m The overriding method.
1706 * @param other The overridden method.
1707 * @return An internationalized string.
1708 */
1709 Fragment uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1710 Symbol mloc = m.location();
1711 Symbol oloc = other.location();
1712
1713 if ((other.owner.flags() & INTERFACE) == 0)
1714 return Fragments.UncheckedOverride(m, mloc, other, oloc);
1715 else if ((m.owner.flags() & INTERFACE) == 0)
1716 return Fragments.UncheckedImplement(m, mloc, other, oloc);
1717 else
1718 return Fragments.UncheckedClashWith(m, mloc, other, oloc);
1719 }
1720
1721 /** A customized "override" warning message.
1722 * @param m The overriding method.
1723 * @param other The overridden method.
1724 * @return An internationalized string.
1725 */
1726 Fragment varargsOverrides(MethodSymbol m, MethodSymbol other) {
1727 Symbol mloc = m.location();
1728 Symbol oloc = other.location();
1729
1730 if ((other.owner.flags() & INTERFACE) == 0)
1731 return Fragments.VarargsOverride(m, mloc, other, oloc);
1732 else if ((m.owner.flags() & INTERFACE) == 0)
1733 return Fragments.VarargsImplement(m, mloc, other, oloc);
1734 else
1735 return Fragments.VarargsClashWith(m, mloc, other, oloc);
1736 }
1737
1738 /** Check that this method conforms with overridden method 'other'.
1739 * where `origin' is the class where checking started.
1740 * Complications:
1741 * (1) Do not check overriding of synthetic methods
1742 * (reason: they might be final).
1743 * todo: check whether this is still necessary.
1744 * (2) Admit the case where an interface proxy throws fewer exceptions
1745 * than the method it implements. Augment the proxy methods with the
1746 * undeclared exceptions in this case.
1747 * (3) When generics are enabled, admit the case where an interface proxy
1748 * has a result type
1749 * extended by the result type of the method it implements.
1750 * Change the proxies result type to the smaller type in this case.
1751 *
1752 * @param tree The tree from which positions
1753 * are extracted for errors.
1754 * @param m The overriding method.
1755 * @param other The overridden method.
1756 * @param origin The class of which the overriding method
1757 * is a member.
1758 */
1759 void checkOverride(JCTree tree,
1760 MethodSymbol m,
1761 MethodSymbol other,
1762 ClassSymbol origin) {
1763 // Don't check overriding of synthetic methods or by bridge methods.
1764 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1765 return;
1766 }
1767
1768 // Error if static method overrides instance method (JLS 8.4.8.2).
1769 if ((m.flags() & STATIC) != 0 &&
1770 (other.flags() & STATIC) == 0) {
1771 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1772 Errors.OverrideStatic(cannotOverride(m, other)));
1773 m.flags_field |= BAD_OVERRIDE;
1774 return;
1775 }
1776
1777 // Error if instance method overrides static or final
1778 // method (JLS 8.4.8.1).
1779 if ((other.flags() & FINAL) != 0 ||
1780 (m.flags() & STATIC) == 0 &&
1781 (other.flags() & STATIC) != 0) {
1782 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1783 Errors.OverrideMeth(cannotOverride(m, other),
1784 asFlagSet(other.flags() & (FINAL | STATIC))));
1785 m.flags_field |= BAD_OVERRIDE;
1786 return;
1787 }
1788
1789 if ((m.owner.flags() & ANNOTATION) != 0) {
1790 // handled in validateAnnotationMethod
1791 return;
1792 }
1793
1794 // Error if overriding method has weaker access (JLS 8.4.8.3).
1795 if (protection(m.flags()) > protection(other.flags())) {
1796 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1797 (other.flags() & AccessFlags) == 0 ?
1798 Errors.OverrideWeakerAccess(cannotOverride(m, other),
1799 "package") :
1800 Errors.OverrideWeakerAccess(cannotOverride(m, other),
1801 asFlagSet(other.flags() & AccessFlags)));
1802 m.flags_field |= BAD_OVERRIDE;
1803 return;
1804 }
1805
1806 if (shouldCheckPreview(m, other, origin)) {
1807 checkPreview(TreeInfo.diagnosticPositionFor(m, tree),
1808 m, origin.type, other);
1809 }
1810
1811 Type mt = types.memberType(origin.type, m);
1812 Type ot = types.memberType(origin.type, other);
1813 // Error if overriding result type is different
1814 // (or, in the case of generics mode, not a subtype) of
1815 // overridden result type. We have to rename any type parameters
1816 // before comparing types.
1817 List<Type> mtvars = mt.getTypeArguments();
1818 List<Type> otvars = ot.getTypeArguments();
1819 Type mtres = mt.getReturnType();
1820 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1821
1822 overrideWarner.clear();
1823 boolean resultTypesOK =
1824 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1825 if (!resultTypesOK) {
1826 if ((m.flags() & STATIC) != 0 && (other.flags() & STATIC) != 0) {
1827 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1828 Errors.OverrideIncompatibleRet(Fragments.CantHide(m, m.location(), other,
1829 other.location()), mtres, otres));
1830 m.flags_field |= BAD_OVERRIDE;
1831 } else {
1832 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1833 Errors.OverrideIncompatibleRet(cannotOverride(m, other), mtres, otres));
1834 m.flags_field |= BAD_OVERRIDE;
1835 }
1836 return;
1837 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1838 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1839 LintWarnings.OverrideUncheckedRet(uncheckedOverrides(m, other), mtres, otres));
1840 }
1841
1842 // Error if overriding method throws an exception not reported
1843 // by overridden method.
1844 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1845 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1846 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1847 if (unhandledErased.nonEmpty()) {
1848 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1849 Errors.OverrideMethDoesntThrow(cannotOverride(m, other), unhandledUnerased.head));
1850 m.flags_field |= BAD_OVERRIDE;
1851 return;
1852 }
1853 else if (unhandledUnerased.nonEmpty()) {
1854 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1855 LintWarnings.OverrideUncheckedThrown(cannotOverride(m, other), unhandledUnerased.head));
1856 return;
1857 }
1858
1859 // Optional warning if varargs don't agree
1860 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)) {
1861 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1862 ((m.flags() & Flags.VARARGS) != 0)
1863 ? LintWarnings.OverrideVarargsMissing(varargsOverrides(m, other))
1864 : LintWarnings.OverrideVarargsExtra(varargsOverrides(m, other)));
1865 }
1866
1867 // Warn if instance method overrides bridge method (compiler spec ??)
1868 if ((other.flags() & BRIDGE) != 0) {
1869 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1870 Warnings.OverrideBridge(uncheckedOverrides(m, other)));
1871 }
1872
1873 // Warn if a deprecated method overridden by a non-deprecated one.
1874 if (!isDeprecatedOverrideIgnorable(other, origin)) {
1875 checkDeprecated(() -> TreeInfo.diagnosticPositionFor(m, tree), m, other);
1876 }
1877 }
1878 // where
1879 private boolean shouldCheckPreview(MethodSymbol m, MethodSymbol other, ClassSymbol origin) {
1880 if (m.owner != origin ||
1881 //performance - only do the expensive checks when the overridden method is a Preview API:
1882 ((other.flags() & PREVIEW_API) == 0 &&
1883 (other.owner.flags() & PREVIEW_API) == 0)) {
1884 return false;
1885 }
1886
1887 for (Symbol s : types.membersClosure(origin.type, false).getSymbolsByName(m.name)) {
1888 if (m != s && m.overrides(s, origin, types, false)) {
1889 //only produce preview warnings or errors if "m" immediatelly overrides "other"
1890 //without intermediate overriding methods:
1891 return s == other;
1892 }
1893 }
1894
1895 return false;
1896 }
1897 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1898 // If the method, m, is defined in an interface, then ignore the issue if the method
1899 // is only inherited via a supertype and also implemented in the supertype,
1900 // because in that case, we will rediscover the issue when examining the method
1901 // in the supertype.
1902 // If the method, m, is not defined in an interface, then the only time we need to
1903 // address the issue is when the method is the supertype implementation: any other
1904 // case, we will have dealt with when examining the supertype classes
1905 ClassSymbol mc = m.enclClass();
1906 Type st = types.supertype(origin.type);
1907 if (!st.hasTag(CLASS))
1908 return true;
1909 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1910
1911 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1912 List<Type> intfs = types.interfaces(origin.type);
1913 return (intfs.contains(mc.type) ? false : (stimpl != null));
1914 }
1915 else
1916 return (stimpl != m);
1917 }
1918
1919
1920 // used to check if there were any unchecked conversions
1921 Warner overrideWarner = new Warner();
1922
1923 /** Check that a class does not inherit two concrete methods
1924 * with the same signature.
1925 * @param pos Position to be used for error reporting.
1926 * @param site The class type to be checked.
1927 */
1928 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1929 Type sup = types.supertype(site);
1930 if (!sup.hasTag(CLASS)) return;
1931
1932 for (Type t1 = sup;
1933 t1.hasTag(CLASS) && t1.tsym.type.isParameterized();
1934 t1 = types.supertype(t1)) {
1935 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) {
1936 if (s1.kind != MTH ||
1937 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1938 !s1.isInheritedIn(site.tsym, types) ||
1939 ((MethodSymbol)s1).implementation(site.tsym,
1940 types,
1941 true) != s1)
1942 continue;
1943 Type st1 = types.memberType(t1, s1);
1944 int s1ArgsLength = st1.getParameterTypes().length();
1945 if (st1 == s1.type) continue;
1946
1947 for (Type t2 = sup;
1948 t2.hasTag(CLASS);
1949 t2 = types.supertype(t2)) {
1950 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) {
1951 if (s2 == s1 ||
1952 s2.kind != MTH ||
1953 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1954 s2.type.getParameterTypes().length() != s1ArgsLength ||
1955 !s2.isInheritedIn(site.tsym, types) ||
1956 ((MethodSymbol)s2).implementation(site.tsym,
1957 types,
1958 true) != s2)
1959 continue;
1960 Type st2 = types.memberType(t2, s2);
1961 if (types.overrideEquivalent(st1, st2))
1962 log.error(pos,
1963 Errors.ConcreteInheritanceConflict(s1, t1, s2, t2, sup));
1964 }
1965 }
1966 }
1967 }
1968 }
1969
1970 /** Check that classes (or interfaces) do not each define an abstract
1971 * method with same name and arguments but incompatible return types.
1972 * @param pos Position to be used for error reporting.
1973 * @param t1 The first argument type.
1974 * @param t2 The second argument type.
1975 */
1976 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1977 Type t1,
1978 Type t2,
1979 Type site) {
1980 if ((site.tsym.flags() & COMPOUND) != 0) {
1981 // special case for intersections: need to eliminate wildcards in supertypes
1982 t1 = types.capture(t1);
1983 t2 = types.capture(t2);
1984 }
1985 return firstIncompatibility(pos, t1, t2, site) == null;
1986 }
1987
1988 /** Return the first method which is defined with same args
1989 * but different return types in two given interfaces, or null if none
1990 * exists.
1991 * @param t1 The first type.
1992 * @param t2 The second type.
1993 * @param site The most derived type.
1994 * @return symbol from t2 that conflicts with one in t1.
1995 */
1996 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1997 Map<TypeSymbol,Type> interfaces1 = new HashMap<>();
1998 closure(t1, interfaces1);
1999 Map<TypeSymbol,Type> interfaces2;
2000 if (t1 == t2)
2001 interfaces2 = interfaces1;
2002 else
2003 closure(t2, interfaces1, interfaces2 = new HashMap<>());
2004
2005 for (Type t3 : interfaces1.values()) {
2006 for (Type t4 : interfaces2.values()) {
2007 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
2008 if (s != null) return s;
2009 }
2010 }
2011 return null;
2012 }
2013
2014 /** Compute all the supertypes of t, indexed by type symbol. */
2015 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
2016 if (!t.hasTag(CLASS)) return;
2017 if (typeMap.put(t.tsym, t) == null) {
2018 closure(types.supertype(t), typeMap);
2019 for (Type i : types.interfaces(t))
2020 closure(i, typeMap);
2021 }
2022 }
2023
2024 /** Compute all the supertypes of t, indexed by type symbol (except those in typesSkip). */
2025 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
2026 if (!t.hasTag(CLASS)) return;
2027 if (typesSkip.get(t.tsym) != null) return;
2028 if (typeMap.put(t.tsym, t) == null) {
2029 closure(types.supertype(t), typesSkip, typeMap);
2030 for (Type i : types.interfaces(t))
2031 closure(i, typesSkip, typeMap);
2032 }
2033 }
2034
2035 /** Return the first method in t2 that conflicts with a method from t1. */
2036 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
2037 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) {
2038 Type st1 = null;
2039 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types) ||
2040 (s1.flags() & SYNTHETIC) != 0) continue;
2041 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
2042 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
2043 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) {
2044 if (s1 == s2) continue;
2045 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types) ||
2046 (s2.flags() & SYNTHETIC) != 0) continue;
2047 if (st1 == null) st1 = types.memberType(t1, s1);
2048 Type st2 = types.memberType(t2, s2);
2049 if (types.overrideEquivalent(st1, st2)) {
2050 List<Type> tvars1 = st1.getTypeArguments();
2051 List<Type> tvars2 = st2.getTypeArguments();
2052 Type rt1 = st1.getReturnType();
2053 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
2054 boolean compat =
2055 types.isSameType(rt1, rt2) ||
2056 !rt1.isPrimitiveOrVoid() &&
2057 !rt2.isPrimitiveOrVoid() &&
2058 (types.covariantReturnType(rt1, rt2, types.noWarnings) ||
2059 types.covariantReturnType(rt2, rt1, types.noWarnings)) ||
2060 checkCommonOverriderIn(s1,s2,site);
2061 if (!compat) {
2062 if (types.isSameType(t1, t2)) {
2063 log.error(pos, Errors.IncompatibleDiffRetSameType(t1,
2064 s2.name, types.memberType(t2, s2).getParameterTypes()));
2065 } else {
2066 log.error(pos, Errors.TypesIncompatible(t1, t2,
2067 Fragments.IncompatibleDiffRet(s2.name, types.memberType(t2, s2).getParameterTypes())));
2068 }
2069 return s2;
2070 }
2071 } else if (checkNameClash((ClassSymbol)site.tsym, s1, s2) &&
2072 !checkCommonOverriderIn(s1, s2, site)) {
2073 log.error(pos, Errors.NameClashSameErasureNoOverride(
2074 s1.name, types.memberType(site, s1).asMethodType().getParameterTypes(), s1.location(),
2075 s2.name, types.memberType(site, s2).asMethodType().getParameterTypes(), s2.location()));
2076 return s2;
2077 }
2078 }
2079 }
2080 return null;
2081 }
2082 //WHERE
2083 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
2084 Map<TypeSymbol,Type> supertypes = new HashMap<>();
2085 Type st1 = types.memberType(site, s1);
2086 Type st2 = types.memberType(site, s2);
2087 closure(site, supertypes);
2088 for (Type t : supertypes.values()) {
2089 for (Symbol s3 : t.tsym.members().getSymbolsByName(s1.name)) {
2090 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
2091 Type st3 = types.memberType(site,s3);
2092 if (types.overrideEquivalent(st3, st1) &&
2093 types.overrideEquivalent(st3, st2) &&
2094 types.returnTypeSubstitutable(st3, st1) &&
2095 types.returnTypeSubstitutable(st3, st2)) {
2096 return true;
2097 }
2098 }
2099 }
2100 return false;
2101 }
2102
2103 /** Check that a given method conforms with any method it overrides.
2104 * @param tree The tree from which positions are extracted
2105 * for errors.
2106 * @param m The overriding method.
2107 */
2108 void checkOverride(Env<AttrContext> env, JCMethodDecl tree, MethodSymbol m) {
2109 ClassSymbol origin = (ClassSymbol)m.owner;
2110 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name)) {
2111 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
2112 log.error(tree.pos(), Errors.EnumNoFinalize);
2113 return;
2114 }
2115 }
2116 if (allowValueClasses && origin.isValueClass() && names.finalize.equals(m.name)) {
2117 if (m.overrides(syms.objectFinalize, origin, types, false)) {
2118 log.warning(tree.pos(), Warnings.ValueFinalize);
2119 }
2120 }
2121 if (allowRecords && origin.isRecord()) {
2122 // let's find out if this is a user defined accessor in which case the @Override annotation is acceptable
2123 Optional<? extends RecordComponent> recordComponent = origin.getRecordComponents().stream()
2124 .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
2125 if (recordComponent.isPresent()) {
2126 return;
2127 }
2128 }
2129
2130 for (Type t = origin.type; t.hasTag(CLASS);
2131 t = types.supertype(t)) {
2132 if (t != origin.type) {
2133 checkOverride(tree, t, origin, m);
2134 }
2135 for (Type t2 : types.interfaces(t)) {
2136 checkOverride(tree, t2, origin, m);
2137 }
2138 }
2139
2140 final boolean explicitOverride = m.attribute(syms.overrideType.tsym) != null;
2141 // Check if this method must override a super method due to being annotated with @Override
2142 // or by virtue of being a member of a diamond inferred anonymous class. Latter case is to
2143 // be treated "as if as they were annotated" with @Override.
2144 boolean mustOverride = explicitOverride ||
2145 (env.info.isAnonymousDiamond && !m.isConstructor() && !m.isPrivate());
2146 if (mustOverride && !isOverrider(m)) {
2147 DiagnosticPosition pos = tree.pos();
2148 for (JCAnnotation a : tree.getModifiers().annotations) {
2149 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2150 pos = a.pos();
2151 break;
2152 }
2153 }
2154 log.error(pos,
2155 explicitOverride ? (m.isStatic() ? Errors.StaticMethodsCannotBeAnnotatedWithOverride(m, m.enclClass()) : Errors.MethodDoesNotOverrideSuperclass(m, m.enclClass())) :
2156 Errors.AnonymousDiamondMethodDoesNotOverrideSuperclass(Fragments.DiamondAnonymousMethodsImplicitlyOverride));
2157 }
2158 }
2159
2160 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
2161 TypeSymbol c = site.tsym;
2162 for (Symbol sym : c.members().getSymbolsByName(m.name)) {
2163 if (m.overrides(sym, origin, types, false)) {
2164 if ((sym.flags() & ABSTRACT) == 0) {
2165 checkOverride(tree, m, (MethodSymbol)sym, origin);
2166 }
2167 }
2168 }
2169 }
2170
2171 private Predicate<Symbol> equalsHasCodeFilter = s -> MethodSymbol.implementation_filter.test(s) &&
2172 (s.flags() & BAD_OVERRIDE) == 0;
2173
2174 public void checkClassOverrideEqualsAndHashIfNeeded(DiagnosticPosition pos,
2175 ClassSymbol someClass) {
2176 /* At present, annotations cannot possibly have a method that is override
2177 * equivalent with Object.equals(Object) but in any case the condition is
2178 * fine for completeness.
2179 */
2180 if (someClass == (ClassSymbol)syms.objectType.tsym ||
2181 someClass.isInterface() || someClass.isEnum() ||
2182 (someClass.flags() & ANNOTATION) != 0 ||
2183 (someClass.flags() & ABSTRACT) != 0) return;
2184 //anonymous inner classes implementing interfaces need especial treatment
2185 if (someClass.isAnonymous()) {
2186 List<Type> interfaces = types.interfaces(someClass.type);
2187 if (interfaces != null && !interfaces.isEmpty() &&
2188 interfaces.head.tsym == syms.comparatorType.tsym) return;
2189 }
2190 checkClassOverrideEqualsAndHash(pos, someClass);
2191 }
2192
2193 private void checkClassOverrideEqualsAndHash(DiagnosticPosition pos,
2194 ClassSymbol someClass) {
2195 if (lint.isEnabled(LintCategory.OVERRIDES)) {
2196 MethodSymbol equalsAtObject = (MethodSymbol)syms.objectType
2197 .tsym.members().findFirst(names.equals);
2198 MethodSymbol hashCodeAtObject = (MethodSymbol)syms.objectType
2199 .tsym.members().findFirst(names.hashCode);
2200 MethodSymbol equalsImpl = types.implementation(equalsAtObject,
2201 someClass, false, equalsHasCodeFilter);
2202 boolean overridesEquals = equalsImpl != null &&
2203 equalsImpl.owner == someClass;
2204 boolean overridesHashCode = types.implementation(hashCodeAtObject,
2205 someClass, false, equalsHasCodeFilter) != hashCodeAtObject;
2206
2207 if (overridesEquals && !overridesHashCode) {
2208 log.warning(pos,
2209 LintWarnings.OverrideEqualsButNotHashcode(someClass));
2210 }
2211 }
2212 }
2213
2214 public void checkHasMain(DiagnosticPosition pos, ClassSymbol c) {
2215 boolean found = false;
2216
2217 for (Symbol sym : c.members().getSymbolsByName(names.main)) {
2218 if (sym.kind == MTH && (sym.flags() & PRIVATE) == 0) {
2219 MethodSymbol meth = (MethodSymbol)sym;
2220 if (!types.isSameType(meth.getReturnType(), syms.voidType)) {
2221 continue;
2222 }
2223 if (meth.params.isEmpty()) {
2224 found = true;
2225 break;
2226 }
2227 if (meth.params.size() != 1) {
2228 continue;
2229 }
2230 if (!types.isSameType(meth.params.head.type, types.makeArrayType(syms.stringType))) {
2231 continue;
2232 }
2233
2234 found = true;
2235 break;
2236 }
2237 }
2238
2239 if (!found) {
2240 log.error(pos, Errors.ImplicitClassDoesNotHaveMainMethod);
2241 }
2242 }
2243
2244 public void checkModuleName (JCModuleDecl tree) {
2245 Name moduleName = tree.sym.name;
2246 Assert.checkNonNull(moduleName);
2247 if (lint.isEnabled(LintCategory.MODULE)) {
2248 JCExpression qualId = tree.qualId;
2249 while (qualId != null) {
2250 Name componentName;
2251 DiagnosticPosition pos;
2252 switch (qualId.getTag()) {
2253 case SELECT:
2254 JCFieldAccess selectNode = ((JCFieldAccess) qualId);
2255 componentName = selectNode.name;
2256 pos = selectNode.pos();
2257 qualId = selectNode.selected;
2258 break;
2259 case IDENT:
2260 componentName = ((JCIdent) qualId).name;
2261 pos = qualId.pos();
2262 qualId = null;
2263 break;
2264 default:
2265 throw new AssertionError("Unexpected qualified identifier: " + qualId.toString());
2266 }
2267 if (componentName != null) {
2268 String moduleNameComponentString = componentName.toString();
2269 int nameLength = moduleNameComponentString.length();
2270 if (nameLength > 0 && Character.isDigit(moduleNameComponentString.charAt(nameLength - 1))) {
2271 log.warning(pos, LintWarnings.PoorChoiceForModuleName(componentName));
2272 }
2273 }
2274 }
2275 }
2276 }
2277
2278 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
2279 ClashFilter cf = new ClashFilter(origin.type);
2280 return (cf.test(s1) &&
2281 cf.test(s2) &&
2282 types.hasSameArgs(s1.erasure(types), s2.erasure(types)));
2283 }
2284
2285
2286 /** Check that all abstract members of given class have definitions.
2287 * @param pos Position to be used for error reporting.
2288 * @param c The class.
2289 */
2290 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
2291 MethodSymbol undef = types.firstUnimplementedAbstract(c);
2292 if (undef != null) {
2293 MethodSymbol undef1 =
2294 new MethodSymbol(undef.flags(), undef.name,
2295 types.memberType(c.type, undef), undef.owner);
2296 log.error(pos,
2297 Errors.DoesNotOverrideAbstract(c, undef1, undef1.location()));
2298 }
2299 }
2300
2301 void checkNonCyclicDecl(JCClassDecl tree) {
2302 CycleChecker cc = new CycleChecker();
2303 cc.scan(tree);
2304 if (!cc.errorFound && !cc.partialCheck) {
2305 tree.sym.flags_field |= ACYCLIC;
2306 }
2307 }
2308
2309 class CycleChecker extends TreeScanner {
2310
2311 Set<Symbol> seenClasses = new HashSet<>();
2312 boolean errorFound = false;
2313 boolean partialCheck = false;
2314
2315 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
2316 if (sym != null && sym.kind == TYP) {
2317 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
2318 if (classEnv != null) {
2319 DiagnosticSource prevSource = log.currentSource();
2320 try {
2321 log.useSource(classEnv.toplevel.sourcefile);
2322 scan(classEnv.tree);
2323 }
2324 finally {
2325 log.useSource(prevSource.getFile());
2326 }
2327 } else if (sym.kind == TYP) {
2328 checkClass(pos, sym, List.nil());
2329 }
2330 } else if (sym == null || sym.kind != PCK) {
2331 //not completed yet
2332 partialCheck = true;
2333 }
2334 }
2335
2336 @Override
2337 public void visitSelect(JCFieldAccess tree) {
2338 super.visitSelect(tree);
2339 checkSymbol(tree.pos(), tree.sym);
2340 }
2341
2342 @Override
2343 public void visitIdent(JCIdent tree) {
2344 checkSymbol(tree.pos(), tree.sym);
2345 }
2346
2347 @Override
2348 public void visitTypeApply(JCTypeApply tree) {
2349 scan(tree.clazz);
2350 }
2351
2352 @Override
2353 public void visitTypeArray(JCArrayTypeTree tree) {
2354 scan(tree.elemtype);
2355 }
2356
2357 @Override
2358 public void visitClassDef(JCClassDecl tree) {
2359 List<JCTree> supertypes = List.nil();
2360 if (tree.getExtendsClause() != null) {
2361 supertypes = supertypes.prepend(tree.getExtendsClause());
2362 }
2363 if (tree.getImplementsClause() != null) {
2364 for (JCTree intf : tree.getImplementsClause()) {
2365 supertypes = supertypes.prepend(intf);
2366 }
2367 }
2368 checkClass(tree.pos(), tree.sym, supertypes);
2369 }
2370
2371 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
2372 if ((c.flags_field & ACYCLIC) != 0)
2373 return;
2374 if (seenClasses.contains(c)) {
2375 errorFound = true;
2376 log.error(pos, Errors.CyclicInheritance(c));
2377 seenClasses.stream()
2378 .filter(s -> !s.type.isErroneous())
2379 .filter(ClassSymbol.class::isInstance)
2380 .map(ClassSymbol.class::cast)
2381 .forEach(Check.this::handleCyclic);
2382 } else if (!c.type.isErroneous()) {
2383 try {
2384 seenClasses.add(c);
2385 if (c.type.hasTag(CLASS)) {
2386 if (supertypes.nonEmpty()) {
2387 scan(supertypes);
2388 }
2389 else {
2390 ClassType ct = (ClassType)c.type;
2391 if (ct.supertype_field == null ||
2392 ct.interfaces_field == null) {
2393 //not completed yet
2394 partialCheck = true;
2395 return;
2396 }
2397 checkSymbol(pos, ct.supertype_field.tsym);
2398 for (Type intf : ct.interfaces_field) {
2399 checkSymbol(pos, intf.tsym);
2400 }
2401 }
2402 if (c.owner.kind == TYP) {
2403 checkSymbol(pos, c.owner);
2404 }
2405 }
2406 } finally {
2407 seenClasses.remove(c);
2408 }
2409 }
2410 }
2411 }
2412
2413 /** Check for cyclic references. Issue an error if the
2414 * symbol of the type referred to has a LOCKED flag set.
2415 *
2416 * @param pos Position to be used for error reporting.
2417 * @param t The type referred to.
2418 */
2419 void checkNonCyclic(DiagnosticPosition pos, Type t) {
2420 checkNonCyclicInternal(pos, t);
2421 }
2422
2423
2424 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
2425 checkNonCyclic1(pos, t, List.nil());
2426 }
2427
2428 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
2429 final TypeVar tv;
2430 if (t.hasTag(TYPEVAR) && (t.tsym.flags() & UNATTRIBUTED) != 0)
2431 return;
2432 if (seen.contains(t)) {
2433 tv = (TypeVar)t;
2434 tv.setUpperBound(types.createErrorType(t));
2435 log.error(pos, Errors.CyclicInheritance(t));
2436 } else if (t.hasTag(TYPEVAR)) {
2437 tv = (TypeVar)t;
2438 seen = seen.prepend(tv);
2439 for (Type b : types.getBounds(tv))
2440 checkNonCyclic1(pos, b, seen);
2441 }
2442 }
2443
2444 /** Check for cyclic references. Issue an error if the
2445 * symbol of the type referred to has a LOCKED flag set.
2446 *
2447 * @param pos Position to be used for error reporting.
2448 * @param t The type referred to.
2449 * @return True if the check completed on all attributed classes
2450 */
2451 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
2452 boolean complete = true; // was the check complete?
2453 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
2454 Symbol c = t.tsym;
2455 if ((c.flags_field & ACYCLIC) != 0) return true;
2456
2457 if ((c.flags_field & LOCKED) != 0) {
2458 log.error(pos, Errors.CyclicInheritance(c));
2459 handleCyclic((ClassSymbol)c);
2460 } else if (!c.type.isErroneous()) {
2461 try {
2462 c.flags_field |= LOCKED;
2463 if (c.type.hasTag(CLASS)) {
2464 ClassType clazz = (ClassType)c.type;
2465 if (clazz.interfaces_field != null)
2466 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
2467 complete &= checkNonCyclicInternal(pos, l.head);
2468 if (clazz.supertype_field != null) {
2469 Type st = clazz.supertype_field;
2470 if (st != null && st.hasTag(CLASS))
2471 complete &= checkNonCyclicInternal(pos, st);
2472 }
2473 if (c.owner.kind == TYP)
2474 complete &= checkNonCyclicInternal(pos, c.owner.type);
2475 }
2476 } finally {
2477 c.flags_field &= ~LOCKED;
2478 }
2479 }
2480 if (complete)
2481 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.isCompleted();
2482 if (complete) c.flags_field |= ACYCLIC;
2483 return complete;
2484 }
2485
2486 /** Handle finding an inheritance cycle on a class by setting
2487 * the class' and its supertypes' types to the error type.
2488 **/
2489 private void handleCyclic(ClassSymbol c) {
2490 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
2491 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
2492 Type st = types.supertype(c.type);
2493 if (st.hasTag(CLASS))
2494 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2495 c.type = types.createErrorType(c, c.type);
2496 c.flags_field |= ACYCLIC;
2497 }
2498
2499 /** Check that all methods which implement some
2500 * method conform to the method they implement.
2501 * @param tree The class definition whose members are checked.
2502 */
2503 void checkImplementations(JCClassDecl tree) {
2504 checkImplementations(tree, tree.sym, tree.sym);
2505 }
2506 //where
2507 /** Check that all methods which implement some
2508 * method in `ic' conform to the method they implement.
2509 */
2510 void checkImplementations(JCTree tree, ClassSymbol origin, ClassSymbol ic) {
2511 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2512 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2513 if ((lc.flags() & ABSTRACT) != 0) {
2514 for (Symbol sym : lc.members().getSymbols(NON_RECURSIVE)) {
2515 if (sym.kind == MTH &&
2516 (sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2517 MethodSymbol absmeth = (MethodSymbol)sym;
2518 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2519 if (implmeth != null && implmeth != absmeth &&
2520 (implmeth.owner.flags() & INTERFACE) ==
2521 (origin.flags() & INTERFACE)) {
2522 // don't check if implmeth is in a class, yet
2523 // origin is an interface. This case arises only
2524 // if implmeth is declared in Object. The reason is
2525 // that interfaces really don't inherit from
2526 // Object it's just that the compiler represents
2527 // things that way.
2528 checkOverride(tree, implmeth, absmeth, origin);
2529 }
2530 }
2531 }
2532 }
2533 }
2534 }
2535
2536 /** Check that all abstract methods implemented by a class are
2537 * mutually compatible.
2538 * @param pos Position to be used for error reporting.
2539 * @param c The class whose interfaces are checked.
2540 */
2541 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2542 List<Type> supertypes = types.interfaces(c);
2543 Type supertype = types.supertype(c);
2544 if (supertype.hasTag(CLASS) &&
2545 (supertype.tsym.flags() & ABSTRACT) != 0)
2546 supertypes = supertypes.prepend(supertype);
2547 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2548 if (!l.head.getTypeArguments().isEmpty() &&
2549 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2550 return;
2551 for (List<Type> m = supertypes; m != l; m = m.tail)
2552 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2553 return;
2554 }
2555 checkCompatibleConcretes(pos, c);
2556
2557 Type identitySuper = null;
2558 Type superType = types.supertype(c);
2559 if (superType.isIdentityClass())
2560 identitySuper = superType;
2561 if (c.isValueClass() && identitySuper != null && identitySuper.tsym != syms.objectType.tsym) { // Object is special
2562 log.error(pos, Errors.ValueTypeHasIdentitySuperType(c, identitySuper));
2563 }
2564 }
2565
2566 /** Check that all non-override equivalent methods accessible from 'site'
2567 * are mutually compatible (JLS 8.4.8/9.4.1).
2568 *
2569 * @param pos Position to be used for error reporting.
2570 * @param site The class whose methods are checked.
2571 * @param sym The method symbol to be checked.
2572 */
2573 void checkOverrideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2574 ClashFilter cf = new ClashFilter(site);
2575 //for each method m1 that is overridden (directly or indirectly)
2576 //by method 'sym' in 'site'...
2577
2578 ArrayList<Symbol> symbolsByName = new ArrayList<>();
2579 types.membersClosure(site, false).getSymbolsByName(sym.name, cf).forEach(symbolsByName::add);
2580 for (Symbol m1 : symbolsByName) {
2581 if (!sym.overrides(m1, site.tsym, types, false)) {
2582 continue;
2583 }
2584
2585 //...check each method m2 that is a member of 'site'
2586 for (Symbol m2 : symbolsByName) {
2587 if (m2 == m1) continue;
2588 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2589 //a member of 'site') and (ii) m1 has the same erasure as m2, issue an error
2590 if (!types.isSubSignature(sym.type, types.memberType(site, m2)) &&
2591 types.hasSameArgs(m2.erasure(types), m1.erasure(types))) {
2592 sym.flags_field |= CLASH;
2593 if (m1 == sym) {
2594 log.error(pos, Errors.NameClashSameErasureNoOverride(
2595 m1.name, types.memberType(site, m1).asMethodType().getParameterTypes(), m1.location(),
2596 m2.name, types.memberType(site, m2).asMethodType().getParameterTypes(), m2.location()));
2597 } else {
2598 ClassType ct = (ClassType)site;
2599 String kind = ct.isInterface() ? "interface" : "class";
2600 log.error(pos, Errors.NameClashSameErasureNoOverride1(
2601 kind,
2602 ct.tsym.name,
2603 m1.name,
2604 types.memberType(site, m1).asMethodType().getParameterTypes(),
2605 m1.location(),
2606 m2.name,
2607 types.memberType(site, m2).asMethodType().getParameterTypes(),
2608 m2.location()));
2609 }
2610 return;
2611 }
2612 }
2613 }
2614 }
2615
2616 /** Check that all static methods accessible from 'site' are
2617 * mutually compatible (JLS 8.4.8).
2618 *
2619 * @param pos Position to be used for error reporting.
2620 * @param site The class whose methods are checked.
2621 * @param sym The method symbol to be checked.
2622 */
2623 void checkHideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2624 ClashFilter cf = new ClashFilter(site);
2625 //for each method m1 that is a member of 'site'...
2626 for (Symbol s : types.membersClosure(site, true).getSymbolsByName(sym.name, cf)) {
2627 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2628 //a member of 'site') and (ii) 'sym' has the same erasure as m1, issue an error
2629 if (!types.isSubSignature(sym.type, types.memberType(site, s))) {
2630 if (types.hasSameArgs(s.erasure(types), sym.erasure(types))) {
2631 log.error(pos,
2632 Errors.NameClashSameErasureNoHide(sym, sym.location(), s, s.location()));
2633 return;
2634 }
2635 }
2636 }
2637 }
2638
2639 //where
2640 private class ClashFilter implements Predicate<Symbol> {
2641
2642 Type site;
2643
2644 ClashFilter(Type site) {
2645 this.site = site;
2646 }
2647
2648 boolean shouldSkip(Symbol s) {
2649 return (s.flags() & CLASH) != 0 &&
2650 s.owner == site.tsym;
2651 }
2652
2653 @Override
2654 public boolean test(Symbol s) {
2655 return s.kind == MTH &&
2656 (s.flags() & SYNTHETIC) == 0 &&
2657 !shouldSkip(s) &&
2658 s.isInheritedIn(site.tsym, types) &&
2659 !s.isConstructor();
2660 }
2661 }
2662
2663 void checkDefaultMethodClashes(DiagnosticPosition pos, Type site) {
2664 DefaultMethodClashFilter dcf = new DefaultMethodClashFilter(site);
2665 for (Symbol m : types.membersClosure(site, false).getSymbols(dcf)) {
2666 Assert.check(m.kind == MTH);
2667 List<MethodSymbol> prov = types.interfaceCandidates(site, (MethodSymbol)m);
2668 if (prov.size() > 1) {
2669 ListBuffer<Symbol> abstracts = new ListBuffer<>();
2670 ListBuffer<Symbol> defaults = new ListBuffer<>();
2671 for (MethodSymbol provSym : prov) {
2672 if ((provSym.flags() & DEFAULT) != 0) {
2673 defaults = defaults.append(provSym);
2674 } else if ((provSym.flags() & ABSTRACT) != 0) {
2675 abstracts = abstracts.append(provSym);
2676 }
2677 if (defaults.nonEmpty() && defaults.size() + abstracts.size() >= 2) {
2678 //strong semantics - issue an error if two sibling interfaces
2679 //have two override-equivalent defaults - or if one is abstract
2680 //and the other is default
2681 Fragment diagKey;
2682 Symbol s1 = defaults.first();
2683 Symbol s2;
2684 if (defaults.size() > 1) {
2685 s2 = defaults.toList().tail.head;
2686 diagKey = Fragments.IncompatibleUnrelatedDefaults(Kinds.kindName(site.tsym), site,
2687 m.name, types.memberType(site, m).getParameterTypes(),
2688 s1.location(), s2.location());
2689
2690 } else {
2691 s2 = abstracts.first();
2692 diagKey = Fragments.IncompatibleAbstractDefault(Kinds.kindName(site.tsym), site,
2693 m.name, types.memberType(site, m).getParameterTypes(),
2694 s1.location(), s2.location());
2695 }
2696 log.error(pos, Errors.TypesIncompatible(s1.location().type, s2.location().type, diagKey));
2697 break;
2698 }
2699 }
2700 }
2701 }
2702 }
2703
2704 //where
2705 private class DefaultMethodClashFilter implements Predicate<Symbol> {
2706
2707 Type site;
2708
2709 DefaultMethodClashFilter(Type site) {
2710 this.site = site;
2711 }
2712
2713 @Override
2714 public boolean test(Symbol s) {
2715 return s.kind == MTH &&
2716 (s.flags() & DEFAULT) != 0 &&
2717 s.isInheritedIn(site.tsym, types) &&
2718 !s.isConstructor();
2719 }
2720 }
2721
2722 /** Report warnings for potentially ambiguous method declarations in the given site. */
2723 void checkPotentiallyAmbiguousOverloads(JCClassDecl tree, Type site) {
2724
2725 // Skip if warning not enabled
2726 if (!lint.isEnabled(LintCategory.OVERLOADS))
2727 return;
2728
2729 // Gather all of site's methods, including overridden methods, grouped by name (except Object methods)
2730 List<java.util.List<MethodSymbol>> methodGroups = methodsGroupedByName(site,
2731 new PotentiallyAmbiguousFilter(site), ArrayList::new);
2732
2733 // Build the predicate that determines if site is responsible for an ambiguity
2734 BiPredicate<MethodSymbol, MethodSymbol> responsible = buildResponsiblePredicate(site, methodGroups);
2735
2736 // Now remove overridden methods from each group, leaving only site's actual members
2737 methodGroups.forEach(list -> removePreempted(list, (m1, m2) -> m1.overrides(m2, site.tsym, types, false)));
2738
2739 // Allow site's own declared methods (only) to apply @SuppressWarnings("overloads")
2740 methodGroups.forEach(list -> list.removeIf(
2741 m -> m.owner == site.tsym && !lint.augment(m).isEnabled(LintCategory.OVERLOADS)));
2742
2743 // Warn about ambiguous overload method pairs for which site is responsible
2744 methodGroups.forEach(list -> compareAndRemove(list, (m1, m2) -> {
2745
2746 // See if this is an ambiguous overload for which "site" is responsible
2747 if (!potentiallyAmbiguousOverload(site, m1, m2) || !responsible.test(m1, m2))
2748 return 0;
2749
2750 // Locate the warning at one of the methods, if possible
2751 DiagnosticPosition pos =
2752 m1.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m1, tree) :
2753 m2.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m2, tree) :
2754 tree.pos();
2755
2756 // Log the warning
2757 log.warning(pos,
2758 LintWarnings.PotentiallyAmbiguousOverload(
2759 m1.asMemberOf(site, types), m1.location(),
2760 m2.asMemberOf(site, types), m2.location()));
2761
2762 // Don't warn again for either of these two methods
2763 return FIRST | SECOND;
2764 }));
2765 }
2766
2767 /** Build a predicate that determines, given two methods that are members of the given class,
2768 * whether the class should be held "responsible" if the methods are potentially ambiguous.
2769 *
2770 * Sometimes ambiguous methods are unavoidable because they're inherited from a supertype.
2771 * For example, any subtype of Spliterator.OfInt will have ambiguities for both
2772 * forEachRemaining() and tryAdvance() (in both cases the overloads are IntConsumer and
2773 * Consumer<? super Integer>). So we only want to "blame" a class when that class is
2774 * itself responsible for creating the ambiguity. We declare that a class C is "responsible"
2775 * for the ambiguity between two methods m1 and m2 if there is no direct supertype T of C
2776 * such that m1 and m2, or some overrides thereof, both exist in T and are ambiguous in T.
2777 * As an optimization, we first check if either method is declared in C and does not override
2778 * any other methods; in this case the class is definitely responsible.
2779 */
2780 BiPredicate<MethodSymbol, MethodSymbol> buildResponsiblePredicate(Type site,
2781 List<? extends Collection<MethodSymbol>> methodGroups) {
2782
2783 // Define the "overrides" predicate
2784 BiPredicate<MethodSymbol, MethodSymbol> overrides = (m1, m2) -> m1.overrides(m2, site.tsym, types, false);
2785
2786 // Map each method declared in site to a list of the supertype method(s) it directly overrides
2787 HashMap<MethodSymbol, ArrayList<MethodSymbol>> overriddenMethodsMap = new HashMap<>();
2788 methodGroups.forEach(list -> {
2789 for (MethodSymbol m : list) {
2790
2791 // Skip methods not declared in site
2792 if (m.owner != site.tsym)
2793 continue;
2794
2795 // Gather all supertype methods overridden by m, directly or indirectly
2796 ArrayList<MethodSymbol> overriddenMethods = list.stream()
2797 .filter(m2 -> m2 != m && overrides.test(m, m2))
2798 .collect(Collectors.toCollection(ArrayList::new));
2799
2800 // Eliminate non-direct overrides
2801 removePreempted(overriddenMethods, overrides);
2802
2803 // Add to map
2804 overriddenMethodsMap.put(m, overriddenMethods);
2805 }
2806 });
2807
2808 // Build the predicate
2809 return (m1, m2) -> {
2810
2811 // Get corresponding supertype methods (if declared in site)
2812 java.util.List<MethodSymbol> overriddenMethods1 = overriddenMethodsMap.get(m1);
2813 java.util.List<MethodSymbol> overriddenMethods2 = overriddenMethodsMap.get(m2);
2814
2815 // Quick check for the case where a method was added by site itself
2816 if (overriddenMethods1 != null && overriddenMethods1.isEmpty())
2817 return true;
2818 if (overriddenMethods2 != null && overriddenMethods2.isEmpty())
2819 return true;
2820
2821 // Get each method's corresponding method(s) from supertypes of site
2822 java.util.List<MethodSymbol> supertypeMethods1 = overriddenMethods1 != null ?
2823 overriddenMethods1 : Collections.singletonList(m1);
2824 java.util.List<MethodSymbol> supertypeMethods2 = overriddenMethods2 != null ?
2825 overriddenMethods2 : Collections.singletonList(m2);
2826
2827 // See if we can blame some direct supertype instead
2828 return types.directSupertypes(site).stream()
2829 .filter(stype -> stype != syms.objectType)
2830 .map(stype -> stype.tsym.type) // view supertype in its original form
2831 .noneMatch(stype -> {
2832 for (MethodSymbol sm1 : supertypeMethods1) {
2833 if (!types.isSubtype(types.erasure(stype), types.erasure(sm1.owner.type)))
2834 continue;
2835 for (MethodSymbol sm2 : supertypeMethods2) {
2836 if (!types.isSubtype(types.erasure(stype), types.erasure(sm2.owner.type)))
2837 continue;
2838 if (potentiallyAmbiguousOverload(stype, sm1, sm2))
2839 return true;
2840 }
2841 }
2842 return false;
2843 });
2844 };
2845 }
2846
2847 /** Gather all of site's methods, including overridden methods, grouped and sorted by name,
2848 * after applying the given filter.
2849 */
2850 <C extends Collection<MethodSymbol>> List<C> methodsGroupedByName(Type site,
2851 Predicate<Symbol> filter, Supplier<? extends C> groupMaker) {
2852 Iterable<Symbol> symbols = types.membersClosure(site, false).getSymbols(filter, RECURSIVE);
2853 return StreamSupport.stream(symbols.spliterator(), false)
2854 .map(MethodSymbol.class::cast)
2855 .collect(Collectors.groupingBy(m -> m.name, Collectors.toCollection(groupMaker)))
2856 .entrySet()
2857 .stream()
2858 .sorted(Comparator.comparing(e -> e.getKey().toString()))
2859 .map(Map.Entry::getValue)
2860 .collect(List.collector());
2861 }
2862
2863 /** Compare elements in a list pair-wise in order to remove some of them.
2864 * @param list mutable list of items
2865 * @param comparer returns flag bit(s) to remove FIRST and/or SECOND
2866 */
2867 <T> void compareAndRemove(java.util.List<T> list, ToIntBiFunction<? super T, ? super T> comparer) {
2868 for (int index1 = 0; index1 < list.size() - 1; index1++) {
2869 T item1 = list.get(index1);
2870 for (int index2 = index1 + 1; index2 < list.size(); index2++) {
2871 T item2 = list.get(index2);
2872 int flags = comparer.applyAsInt(item1, item2);
2873 if ((flags & SECOND) != 0)
2874 list.remove(index2--); // remove item2
2875 if ((flags & FIRST) != 0) {
2876 list.remove(index1--); // remove item1
2877 break;
2878 }
2879 }
2880 }
2881 }
2882
2883 /** Remove elements in a list that are preempted by some other element in the list.
2884 * @param list mutable list of items
2885 * @param preempts decides if one item preempts another, causing the second one to be removed
2886 */
2887 <T> void removePreempted(java.util.List<T> list, BiPredicate<? super T, ? super T> preempts) {
2888 compareAndRemove(list, (item1, item2) -> {
2889 int flags = 0;
2890 if (preempts.test(item1, item2))
2891 flags |= SECOND;
2892 if (preempts.test(item2, item1))
2893 flags |= FIRST;
2894 return flags;
2895 });
2896 }
2897
2898 /** Filters method candidates for the "potentially ambiguous method" check */
2899 class PotentiallyAmbiguousFilter extends ClashFilter {
2900
2901 PotentiallyAmbiguousFilter(Type site) {
2902 super(site);
2903 }
2904
2905 @Override
2906 boolean shouldSkip(Symbol s) {
2907 return s.owner.type.tsym == syms.objectType.tsym || super.shouldSkip(s);
2908 }
2909 }
2910
2911 /**
2912 * Report warnings for potentially ambiguous method declarations. Two declarations
2913 * are potentially ambiguous if they feature two unrelated functional interface
2914 * in same argument position (in which case, a call site passing an implicit
2915 * lambda would be ambiguous). This assumes they already have the same name.
2916 */
2917 boolean potentiallyAmbiguousOverload(Type site, MethodSymbol msym1, MethodSymbol msym2) {
2918 Assert.check(msym1.name == msym2.name);
2919 if (msym1 == msym2)
2920 return false;
2921 Type mt1 = types.memberType(site, msym1);
2922 Type mt2 = types.memberType(site, msym2);
2923 //if both generic methods, adjust type variables
2924 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL) &&
2925 types.hasSameBounds((ForAll)mt1, (ForAll)mt2)) {
2926 mt2 = types.subst(mt2, ((ForAll)mt2).tvars, ((ForAll)mt1).tvars);
2927 }
2928 //expand varargs methods if needed
2929 int maxLength = Math.max(mt1.getParameterTypes().length(), mt2.getParameterTypes().length());
2930 List<Type> args1 = rs.adjustArgs(mt1.getParameterTypes(), msym1, maxLength, true);
2931 List<Type> args2 = rs.adjustArgs(mt2.getParameterTypes(), msym2, maxLength, true);
2932 //if arities don't match, exit
2933 if (args1.length() != args2.length())
2934 return false;
2935 boolean potentiallyAmbiguous = false;
2936 while (args1.nonEmpty() && args2.nonEmpty()) {
2937 Type s = args1.head;
2938 Type t = args2.head;
2939 if (!types.isSubtype(t, s) && !types.isSubtype(s, t)) {
2940 if (types.isFunctionalInterface(s) && types.isFunctionalInterface(t) &&
2941 types.findDescriptorType(s).getParameterTypes().length() > 0 &&
2942 types.findDescriptorType(s).getParameterTypes().length() ==
2943 types.findDescriptorType(t).getParameterTypes().length()) {
2944 potentiallyAmbiguous = true;
2945 } else {
2946 return false;
2947 }
2948 }
2949 args1 = args1.tail;
2950 args2 = args2.tail;
2951 }
2952 return potentiallyAmbiguous;
2953 }
2954
2955 // Apply special flag "-XDwarnOnAccessToMembers" which turns on just this particular warning for all types of access
2956 void checkAccessFromSerializableElement(final JCTree tree, boolean isLambda) {
2957 if (warnOnAnyAccessToMembers || isLambda)
2958 checkAccessFromSerializableElementInner(tree, isLambda);
2959 }
2960
2961 private void checkAccessFromSerializableElementInner(final JCTree tree, boolean isLambda) {
2962 Symbol sym = TreeInfo.symbol(tree);
2963 if (!sym.kind.matches(KindSelector.VAL_MTH)) {
2964 return;
2965 }
2966
2967 if (sym.kind == VAR) {
2968 if ((sym.flags() & PARAMETER) != 0 ||
2969 sym.isDirectlyOrIndirectlyLocal() ||
2970 sym.name == names._this ||
2971 sym.name == names._super) {
2972 return;
2973 }
2974 }
2975
2976 if (!types.isSubtype(sym.owner.type, syms.serializableType) && isEffectivelyNonPublic(sym)) {
2977 DiagnosticFlag flag = warnOnAnyAccessToMembers ? DiagnosticFlag.DEFAULT_ENABLED : null;
2978 if (isLambda) {
2979 if (belongsToRestrictedPackage(sym)) {
2980 log.warning(flag, tree.pos(), LintWarnings.AccessToMemberFromSerializableLambda(sym));
2981 }
2982 } else {
2983 log.warning(flag, tree.pos(), LintWarnings.AccessToMemberFromSerializableElement(sym));
2984 }
2985 }
2986 }
2987
2988 private boolean isEffectivelyNonPublic(Symbol sym) {
2989 if (sym.packge() == syms.rootPackage) {
2990 return false;
2991 }
2992
2993 while (sym.kind != PCK) {
2994 if ((sym.flags() & PUBLIC) == 0) {
2995 return true;
2996 }
2997 sym = sym.owner;
2998 }
2999 return false;
3000 }
3001
3002 private boolean belongsToRestrictedPackage(Symbol sym) {
3003 String fullName = sym.packge().fullname.toString();
3004 return fullName.startsWith("java.") ||
3005 fullName.startsWith("javax.") ||
3006 fullName.startsWith("sun.") ||
3007 fullName.contains(".internal.");
3008 }
3009
3010 /** Check that class c does not implement directly or indirectly
3011 * the same parameterized interface with two different argument lists.
3012 * @param pos Position to be used for error reporting.
3013 * @param type The type whose interfaces are checked.
3014 */
3015 void checkClassBounds(DiagnosticPosition pos, Type type) {
3016 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
3017 }
3018 //where
3019 /** Enter all interfaces of type `type' into the hash table `seensofar'
3020 * with their class symbol as key and their type as value. Make
3021 * sure no class is entered with two different types.
3022 */
3023 void checkClassBounds(DiagnosticPosition pos,
3024 Map<TypeSymbol,Type> seensofar,
3025 Type type) {
3026 if (type.isErroneous()) return;
3027 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
3028 Type it = l.head;
3029 if (type.hasTag(CLASS) && !it.hasTag(CLASS)) continue; // JLS 8.1.5
3030
3031 Type oldit = seensofar.put(it.tsym, it);
3032 if (oldit != null) {
3033 List<Type> oldparams = oldit.allparams();
3034 List<Type> newparams = it.allparams();
3035 if (!types.containsTypeEquivalent(oldparams, newparams))
3036 log.error(pos,
3037 Errors.CantInheritDiffArg(it.tsym,
3038 Type.toString(oldparams),
3039 Type.toString(newparams)));
3040 }
3041 checkClassBounds(pos, seensofar, it);
3042 }
3043 Type st = types.supertype(type);
3044 if (type.hasTag(CLASS) && !st.hasTag(CLASS)) return; // JLS 8.1.4
3045 if (st != Type.noType) checkClassBounds(pos, seensofar, st);
3046 }
3047
3048 /** Enter interface into into set.
3049 * If it existed already, issue a "repeated interface" error.
3050 */
3051 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Symbol> its) {
3052 if (its.contains(it.tsym))
3053 log.error(pos, Errors.RepeatedInterface);
3054 else {
3055 its.add(it.tsym);
3056 }
3057 }
3058
3059 /* *************************************************************************
3060 * Check annotations
3061 **************************************************************************/
3062
3063 /**
3064 * Recursively validate annotations values
3065 */
3066 void validateAnnotationTree(JCTree tree) {
3067 class AnnotationValidator extends TreeScanner {
3068 @Override
3069 public void visitAnnotation(JCAnnotation tree) {
3070 if (!tree.type.isErroneous() && tree.type.tsym.isAnnotationType()) {
3071 super.visitAnnotation(tree);
3072 validateAnnotation(tree);
3073 }
3074 }
3075 }
3076 tree.accept(new AnnotationValidator());
3077 }
3078
3079 /**
3080 * {@literal
3081 * Annotation types are restricted to primitives, String, an
3082 * enum, an annotation, Class, Class<?>, Class<? extends
3083 * Anything>, arrays of the preceding.
3084 * }
3085 */
3086 void validateAnnotationType(JCTree restype) {
3087 // restype may be null if an error occurred, so don't bother validating it
3088 if (restype != null) {
3089 validateAnnotationType(restype.pos(), restype.type);
3090 }
3091 }
3092
3093 void validateAnnotationType(DiagnosticPosition pos, Type type) {
3094 if (type.isPrimitive()) return;
3095 if (types.isSameType(type, syms.stringType)) return;
3096 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
3097 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
3098 if (types.cvarLowerBound(type).tsym == syms.classType.tsym) return;
3099 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
3100 validateAnnotationType(pos, types.elemtype(type));
3101 return;
3102 }
3103 log.error(pos, Errors.InvalidAnnotationMemberType);
3104 }
3105
3106 /**
3107 * "It is also a compile-time error if any method declared in an
3108 * annotation type has a signature that is override-equivalent to
3109 * that of any public or protected method declared in class Object
3110 * or in the interface annotation.Annotation."
3111 *
3112 * @jls 9.6 Annotation Types
3113 */
3114 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
3115 for (Type sup = syms.annotationType; sup.hasTag(CLASS); sup = types.supertype(sup)) {
3116 Scope s = sup.tsym.members();
3117 for (Symbol sym : s.getSymbolsByName(m.name)) {
3118 if (sym.kind == MTH &&
3119 (sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
3120 types.overrideEquivalent(m.type, sym.type))
3121 log.error(pos, Errors.IntfAnnotationMemberClash(sym, sup));
3122 }
3123 }
3124 }
3125
3126 /** Check the annotations of a symbol.
3127 */
3128 public void validateAnnotations(List<JCAnnotation> annotations, JCTree declarationTree, Symbol s) {
3129 for (JCAnnotation a : annotations)
3130 validateAnnotation(a, declarationTree, s);
3131 }
3132
3133 /** Check the type annotations.
3134 */
3135 public void validateTypeAnnotations(List<JCAnnotation> annotations, Symbol s, boolean isTypeParameter) {
3136 for (JCAnnotation a : annotations)
3137 validateTypeAnnotation(a, s, isTypeParameter);
3138 }
3139
3140 /** Check an annotation of a symbol.
3141 */
3142 private void validateAnnotation(JCAnnotation a, JCTree declarationTree, Symbol s) {
3143 /** NOTE: if annotation processors are present, annotation processing rounds can happen after this method,
3144 * this can impact in particular records for which annotations are forcibly propagated.
3145 */
3146 validateAnnotationTree(a);
3147 boolean isRecordMember = ((s.flags_field & RECORD) != 0 || s.enclClass() != null && s.enclClass().isRecord());
3148
3149 boolean isRecordField = (s.flags_field & RECORD) != 0 &&
3150 declarationTree.hasTag(VARDEF) &&
3151 s.owner.kind == TYP;
3152
3153 if (isRecordField) {
3154 // first we need to check if the annotation is applicable to records
3155 Name[] targets = getTargetNames(a);
3156 boolean appliesToRecords = false;
3157 for (Name target : targets) {
3158 appliesToRecords =
3159 target == names.FIELD ||
3160 target == names.PARAMETER ||
3161 target == names.METHOD ||
3162 target == names.TYPE_USE ||
3163 target == names.RECORD_COMPONENT;
3164 if (appliesToRecords) {
3165 break;
3166 }
3167 }
3168 if (!appliesToRecords) {
3169 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3170 } else {
3171 /* lets now find the annotations in the field that are targeted to record components and append them to
3172 * the corresponding record component
3173 */
3174 ClassSymbol recordClass = (ClassSymbol) s.owner;
3175 RecordComponent rc = recordClass.getRecordComponent((VarSymbol)s);
3176 SymbolMetadata metadata = rc.getMetadata();
3177 if (metadata == null || metadata.isEmpty()) {
3178 /* if not is empty then we have already been here, which is the case if multiple annotations are applied
3179 * to the record component declaration
3180 */
3181 rc.appendAttributes(s.getRawAttributes().stream().filter(anno ->
3182 Arrays.stream(getTargetNames(anno.type.tsym)).anyMatch(name -> name == names.RECORD_COMPONENT)
3183 ).collect(List.collector()));
3184
3185 JCVariableDecl fieldAST = (JCVariableDecl) declarationTree;
3186 for (JCAnnotation fieldAnnot : fieldAST.mods.annotations) {
3187 for (JCAnnotation rcAnnot : rc.declarationFor().mods.annotations) {
3188 if (rcAnnot.pos == fieldAnnot.pos) {
3189 rcAnnot.setType(fieldAnnot.type);
3190 break;
3191 }
3192 }
3193 }
3194
3195 /* At this point, we used to carry over any type annotations from the VARDEF to the record component, but
3196 * that is problematic, since we get here only when *some* annotation is applied to the SE5 (declaration)
3197 * annotation location, inadvertently failing to carry over the type annotations when the VarDef has no
3198 * annotations in the SE5 annotation location.
3199 *
3200 * Now type annotations are assigned to record components in a method that would execute irrespective of
3201 * whether there are SE5 annotations on a VarDef viz com.sun.tools.javac.code.TypeAnnotations.TypeAnnotationPositions.visitVarDef
3202 */
3203 }
3204 }
3205 }
3206
3207 /* the section below is tricky. Annotations applied to record components are propagated to the corresponding
3208 * record member so if an annotation has target: FIELD, it is propagated to the corresponding FIELD, if it has
3209 * target METHOD, it is propagated to the accessor and so on. But at the moment when method members are generated
3210 * there is no enough information to propagate only the right annotations. So all the annotations are propagated
3211 * to all the possible locations.
3212 *
3213 * At this point we need to remove all the annotations that are not in place before going on with the annotation
3214 * party. On top of the above there is the issue that there is no AST representing record components, just symbols
3215 * so the corresponding field has been holding all the annotations and it's metadata has been modified as if it
3216 * was both a field and a record component.
3217 *
3218 * So there are two places where we need to trim annotations from: the metadata of the symbol and / or the modifiers
3219 * in the AST. Whatever is in the metadata will be written to the class file, whatever is in the modifiers could
3220 * be see by annotation processors.
3221 *
3222 * The metadata contains both type annotations and declaration annotations. At this point of the game we don't
3223 * need to care about type annotations, they are all in the right place. But we could need to remove declaration
3224 * annotations. So for declaration annotations if they are not applicable to the record member, excluding type
3225 * annotations which are already correct, then we will remove it. For the AST modifiers if the annotation is not
3226 * applicable either as type annotation and or declaration annotation, only in that case it will be removed.
3227 *
3228 * So it could be that annotation is removed as a declaration annotation but it is kept in the AST modifier for
3229 * further inspection by annotation processors.
3230 *
3231 * For example:
3232 *
3233 * import java.lang.annotation.*;
3234 *
3235 * @Target({ElementType.TYPE_USE, ElementType.RECORD_COMPONENT})
3236 * @Retention(RetentionPolicy.RUNTIME)
3237 * @interface Anno { }
3238 *
3239 * record R(@Anno String s) {}
3240 *
3241 * at this point we will have for the case of the generated field:
3242 * - @Anno in the modifier
3243 * - @Anno as a type annotation
3244 * - @Anno as a declaration annotation
3245 *
3246 * the last one should be removed because the annotation has not FIELD as target but it was applied as a
3247 * declaration annotation because the field was being treated both as a field and as a record component
3248 * as we have already copied the annotations to the record component, now the field doesn't need to hold
3249 * annotations that are not intended for it anymore. Still @Anno has to be kept in the AST's modifiers as it
3250 * is applicable as a type annotation to the type of the field.
3251 */
3252
3253 if (a.type.tsym.isAnnotationType()) {
3254 Optional<Set<Name>> applicableTargetsOp = getApplicableTargets(a, s);
3255 if (!applicableTargetsOp.isEmpty()) {
3256 Set<Name> applicableTargets = applicableTargetsOp.get();
3257 boolean notApplicableOrIsTypeUseOnly = applicableTargets.isEmpty() ||
3258 applicableTargets.size() == 1 && applicableTargets.contains(names.TYPE_USE);
3259 boolean isCompGeneratedRecordElement = isRecordMember && (s.flags_field & Flags.GENERATED_MEMBER) != 0;
3260 boolean isCompRecordElementWithNonApplicableDeclAnno = isCompGeneratedRecordElement && notApplicableOrIsTypeUseOnly;
3261
3262 if (applicableTargets.isEmpty() || isCompRecordElementWithNonApplicableDeclAnno) {
3263 if (isCompRecordElementWithNonApplicableDeclAnno) {
3264 /* so we have found an annotation that is not applicable to a record member that was generated by the
3265 * compiler. This was intentionally done at TypeEnter, now is the moment strip away the annotations
3266 * that are not applicable to the given record member
3267 */
3268 JCModifiers modifiers = TreeInfo.getModifiers(declarationTree);
3269 /* lets first remove the annotation from the modifier if it is not applicable, we have to check again as
3270 * it could be a type annotation
3271 */
3272 if (modifiers != null && applicableTargets.isEmpty()) {
3273 ListBuffer<JCAnnotation> newAnnotations = new ListBuffer<>();
3274 for (JCAnnotation anno : modifiers.annotations) {
3275 if (anno != a) {
3276 newAnnotations.add(anno);
3277 }
3278 }
3279 modifiers.annotations = newAnnotations.toList();
3280 }
3281 // now lets remove it from the symbol
3282 s.getMetadata().removeDeclarationMetadata(a.attribute);
3283 } else {
3284 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3285 }
3286 }
3287 /* if we are seeing the @SafeVarargs annotation applied to a compiler generated accessor,
3288 * then this is an error as we know that no compiler generated accessor will be a varargs
3289 * method, better to fail asap
3290 */
3291 if (isCompGeneratedRecordElement && !isRecordField && a.type.tsym == syms.trustMeType.tsym && declarationTree.hasTag(METHODDEF)) {
3292 log.error(a.pos(), Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym, Fragments.VarargsTrustmeOnNonVarargsAccessor(s)));
3293 }
3294 }
3295 }
3296
3297 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
3298 if (s.kind != TYP) {
3299 log.error(a.pos(), Errors.BadFunctionalIntfAnno);
3300 } else if (!s.isInterface() || (s.flags() & ANNOTATION) != 0) {
3301 log.error(a.pos(), Errors.BadFunctionalIntfAnno1(Fragments.NotAFunctionalIntf(s)));
3302 }
3303 }
3304 }
3305
3306 public void validateTypeAnnotation(JCAnnotation a, Symbol s, boolean isTypeParameter) {
3307 Assert.checkNonNull(a.type);
3308 // we just want to validate that the anotation doesn't have any wrong target
3309 if (s != null) getApplicableTargets(a, s);
3310 validateAnnotationTree(a);
3311
3312 if (a.hasTag(TYPE_ANNOTATION) &&
3313 !a.annotationType.type.isErroneous() &&
3314 !isTypeAnnotation(a, isTypeParameter)) {
3315 log.error(a.pos(), Errors.AnnotationTypeNotApplicableToType(a.type));
3316 }
3317 }
3318
3319 /**
3320 * Validate the proposed container 'repeatable' on the
3321 * annotation type symbol 's'. Report errors at position
3322 * 'pos'.
3323 *
3324 * @param s The (annotation)type declaration annotated with a @Repeatable
3325 * @param repeatable the @Repeatable on 's'
3326 * @param pos where to report errors
3327 */
3328 public void validateRepeatable(TypeSymbol s, Attribute.Compound repeatable, DiagnosticPosition pos) {
3329 Assert.check(types.isSameType(repeatable.type, syms.repeatableType));
3330
3331 Type t = null;
3332 List<Pair<MethodSymbol,Attribute>> l = repeatable.values;
3333 if (!l.isEmpty()) {
3334 Assert.check(l.head.fst.name == names.value);
3335 if (l.head.snd instanceof Attribute.Class) {
3336 t = ((Attribute.Class)l.head.snd).getValue();
3337 }
3338 }
3339
3340 if (t == null) {
3341 // errors should already have been reported during Annotate
3342 return;
3343 }
3344
3345 validateValue(t.tsym, s, pos);
3346 validateRetention(t.tsym, s, pos);
3347 validateDocumented(t.tsym, s, pos);
3348 validateInherited(t.tsym, s, pos);
3349 validateTarget(t.tsym, s, pos);
3350 validateDefault(t.tsym, pos);
3351 }
3352
3353 private void validateValue(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3354 Symbol sym = container.members().findFirst(names.value);
3355 if (sym != null && sym.kind == MTH) {
3356 MethodSymbol m = (MethodSymbol) sym;
3357 Type ret = m.getReturnType();
3358 if (!(ret.hasTag(ARRAY) && types.isSameType(((ArrayType)ret).elemtype, contained.type))) {
3359 log.error(pos,
3360 Errors.InvalidRepeatableAnnotationValueReturn(container,
3361 ret,
3362 types.makeArrayType(contained.type)));
3363 }
3364 } else {
3365 log.error(pos, Errors.InvalidRepeatableAnnotationNoValue(container));
3366 }
3367 }
3368
3369 private void validateRetention(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3370 Attribute.RetentionPolicy containerRetention = types.getRetention(container);
3371 Attribute.RetentionPolicy containedRetention = types.getRetention(contained);
3372
3373 boolean error = false;
3374 switch (containedRetention) {
3375 case RUNTIME:
3376 if (containerRetention != Attribute.RetentionPolicy.RUNTIME) {
3377 error = true;
3378 }
3379 break;
3380 case CLASS:
3381 if (containerRetention == Attribute.RetentionPolicy.SOURCE) {
3382 error = true;
3383 }
3384 }
3385 if (error ) {
3386 log.error(pos,
3387 Errors.InvalidRepeatableAnnotationRetention(container,
3388 containerRetention.name(),
3389 contained,
3390 containedRetention.name()));
3391 }
3392 }
3393
3394 private void validateDocumented(Symbol container, Symbol contained, DiagnosticPosition pos) {
3395 if (contained.attribute(syms.documentedType.tsym) != null) {
3396 if (container.attribute(syms.documentedType.tsym) == null) {
3397 log.error(pos, Errors.InvalidRepeatableAnnotationNotDocumented(container, contained));
3398 }
3399 }
3400 }
3401
3402 private void validateInherited(Symbol container, Symbol contained, DiagnosticPosition pos) {
3403 if (contained.attribute(syms.inheritedType.tsym) != null) {
3404 if (container.attribute(syms.inheritedType.tsym) == null) {
3405 log.error(pos, Errors.InvalidRepeatableAnnotationNotInherited(container, contained));
3406 }
3407 }
3408 }
3409
3410 private void validateTarget(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3411 // The set of targets the container is applicable to must be a subset
3412 // (with respect to annotation target semantics) of the set of targets
3413 // the contained is applicable to. The target sets may be implicit or
3414 // explicit.
3415
3416 Set<Name> containerTargets;
3417 Attribute.Array containerTarget = getAttributeTargetAttribute(container);
3418 if (containerTarget == null) {
3419 containerTargets = getDefaultTargetSet();
3420 } else {
3421 containerTargets = new HashSet<>();
3422 for (Attribute app : containerTarget.values) {
3423 if (!(app instanceof Attribute.Enum attributeEnum)) {
3424 continue; // recovery
3425 }
3426 containerTargets.add(attributeEnum.value.name);
3427 }
3428 }
3429
3430 Set<Name> containedTargets;
3431 Attribute.Array containedTarget = getAttributeTargetAttribute(contained);
3432 if (containedTarget == null) {
3433 containedTargets = getDefaultTargetSet();
3434 } else {
3435 containedTargets = new HashSet<>();
3436 for (Attribute app : containedTarget.values) {
3437 if (!(app instanceof Attribute.Enum attributeEnum)) {
3438 continue; // recovery
3439 }
3440 containedTargets.add(attributeEnum.value.name);
3441 }
3442 }
3443
3444 if (!isTargetSubsetOf(containerTargets, containedTargets)) {
3445 log.error(pos, Errors.InvalidRepeatableAnnotationIncompatibleTarget(container, contained));
3446 }
3447 }
3448
3449 /* get a set of names for the default target */
3450 private Set<Name> getDefaultTargetSet() {
3451 if (defaultTargets == null) {
3452 defaultTargets = Set.of(defaultTargetMetaInfo());
3453 }
3454
3455 return defaultTargets;
3456 }
3457 private Set<Name> defaultTargets;
3458
3459
3460 /** Checks that s is a subset of t, with respect to ElementType
3461 * semantics, specifically {ANNOTATION_TYPE} is a subset of {TYPE},
3462 * and {TYPE_USE} covers the set {ANNOTATION_TYPE, TYPE, TYPE_USE,
3463 * TYPE_PARAMETER}.
3464 */
3465 private boolean isTargetSubsetOf(Set<Name> s, Set<Name> t) {
3466 // Check that all elements in s are present in t
3467 for (Name n2 : s) {
3468 boolean currentElementOk = false;
3469 for (Name n1 : t) {
3470 if (n1 == n2) {
3471 currentElementOk = true;
3472 break;
3473 } else if (n1 == names.TYPE && n2 == names.ANNOTATION_TYPE) {
3474 currentElementOk = true;
3475 break;
3476 } else if (n1 == names.TYPE_USE &&
3477 (n2 == names.TYPE ||
3478 n2 == names.ANNOTATION_TYPE ||
3479 n2 == names.TYPE_PARAMETER)) {
3480 currentElementOk = true;
3481 break;
3482 }
3483 }
3484 if (!currentElementOk)
3485 return false;
3486 }
3487 return true;
3488 }
3489
3490 private void validateDefault(Symbol container, DiagnosticPosition pos) {
3491 // validate that all other elements of containing type has defaults
3492 Scope scope = container.members();
3493 for(Symbol elm : scope.getSymbols()) {
3494 if (elm.name != names.value &&
3495 elm.kind == MTH &&
3496 ((MethodSymbol)elm).defaultValue == null) {
3497 log.error(pos,
3498 Errors.InvalidRepeatableAnnotationElemNondefault(container, elm));
3499 }
3500 }
3501 }
3502
3503 /** Is s a method symbol that overrides a method in a superclass? */
3504 boolean isOverrider(Symbol s) {
3505 if (s.kind != MTH || s.isStatic())
3506 return false;
3507 MethodSymbol m = (MethodSymbol)s;
3508 TypeSymbol owner = (TypeSymbol)m.owner;
3509 for (Type sup : types.closure(owner.type)) {
3510 if (sup == owner.type)
3511 continue; // skip "this"
3512 Scope scope = sup.tsym.members();
3513 for (Symbol sym : scope.getSymbolsByName(m.name)) {
3514 if (!sym.isStatic() && m.overrides(sym, owner, types, true))
3515 return true;
3516 }
3517 }
3518 return false;
3519 }
3520
3521 /** Is the annotation applicable to types? */
3522 protected boolean isTypeAnnotation(JCAnnotation a, boolean isTypeParameter) {
3523 List<Attribute> targets = typeAnnotations.annotationTargets(a.annotationType.type.tsym);
3524 return (targets == null) ?
3525 (Feature.NO_TARGET_ANNOTATION_APPLICABILITY.allowedInSource(source) && isTypeParameter) :
3526 targets.stream()
3527 .anyMatch(attr -> isTypeAnnotation(attr, isTypeParameter));
3528 }
3529 //where
3530 boolean isTypeAnnotation(Attribute a, boolean isTypeParameter) {
3531 Attribute.Enum e = (Attribute.Enum)a;
3532 return (e.value.name == names.TYPE_USE ||
3533 (isTypeParameter && e.value.name == names.TYPE_PARAMETER));
3534 }
3535
3536 /** Is the annotation applicable to the symbol? */
3537 Name[] getTargetNames(JCAnnotation a) {
3538 return getTargetNames(a.annotationType.type.tsym);
3539 }
3540
3541 public Name[] getTargetNames(TypeSymbol annoSym) {
3542 Attribute.Array arr = getAttributeTargetAttribute(annoSym);
3543 Name[] targets;
3544 if (arr == null) {
3545 targets = defaultTargetMetaInfo();
3546 } else {
3547 // TODO: can we optimize this?
3548 targets = new Name[arr.values.length];
3549 for (int i=0; i<arr.values.length; ++i) {
3550 Attribute app = arr.values[i];
3551 if (!(app instanceof Attribute.Enum attributeEnum)) {
3552 return new Name[0];
3553 }
3554 targets[i] = attributeEnum.value.name;
3555 }
3556 }
3557 return targets;
3558 }
3559
3560 boolean annotationApplicable(JCAnnotation a, Symbol s) {
3561 Optional<Set<Name>> targets = getApplicableTargets(a, s);
3562 /* the optional could be empty if the annotation is unknown in that case
3563 * we return that it is applicable and if it is erroneous that should imply
3564 * an error at the declaration site
3565 */
3566 return targets.isEmpty() || targets.isPresent() && !targets.get().isEmpty();
3567 }
3568
3569 Optional<Set<Name>> getApplicableTargets(JCAnnotation a, Symbol s) {
3570 Attribute.Array arr = getAttributeTargetAttribute(a.annotationType.type.tsym);
3571 Name[] targets;
3572 Set<Name> applicableTargets = new HashSet<>();
3573
3574 if (arr == null) {
3575 targets = defaultTargetMetaInfo();
3576 } else {
3577 // TODO: can we optimize this?
3578 targets = new Name[arr.values.length];
3579 for (int i=0; i<arr.values.length; ++i) {
3580 Attribute app = arr.values[i];
3581 if (!(app instanceof Attribute.Enum attributeEnum)) {
3582 // recovery
3583 return Optional.empty();
3584 }
3585 targets[i] = attributeEnum.value.name;
3586 }
3587 }
3588 for (Name target : targets) {
3589 if (target == names.TYPE) {
3590 if (s.kind == TYP)
3591 applicableTargets.add(names.TYPE);
3592 } else if (target == names.FIELD) {
3593 if (s.kind == VAR && s.owner.kind != MTH)
3594 applicableTargets.add(names.FIELD);
3595 } else if (target == names.RECORD_COMPONENT) {
3596 if (s.getKind() == ElementKind.RECORD_COMPONENT) {
3597 applicableTargets.add(names.RECORD_COMPONENT);
3598 }
3599 } else if (target == names.METHOD) {
3600 if (s.kind == MTH && !s.isConstructor())
3601 applicableTargets.add(names.METHOD);
3602 } else if (target == names.PARAMETER) {
3603 if (s.kind == VAR &&
3604 (s.owner.kind == MTH && (s.flags() & PARAMETER) != 0)) {
3605 applicableTargets.add(names.PARAMETER);
3606 }
3607 } else if (target == names.CONSTRUCTOR) {
3608 if (s.kind == MTH && s.isConstructor())
3609 applicableTargets.add(names.CONSTRUCTOR);
3610 } else if (target == names.LOCAL_VARIABLE) {
3611 if (s.kind == VAR && s.owner.kind == MTH &&
3612 (s.flags() & PARAMETER) == 0) {
3613 applicableTargets.add(names.LOCAL_VARIABLE);
3614 }
3615 } else if (target == names.ANNOTATION_TYPE) {
3616 if (s.kind == TYP && (s.flags() & ANNOTATION) != 0) {
3617 applicableTargets.add(names.ANNOTATION_TYPE);
3618 }
3619 } else if (target == names.PACKAGE) {
3620 if (s.kind == PCK)
3621 applicableTargets.add(names.PACKAGE);
3622 } else if (target == names.TYPE_USE) {
3623 if (s.kind == VAR &&
3624 (s.flags() & Flags.VAR_VARIABLE) != 0 &&
3625 (!Feature.TYPE_ANNOTATIONS_ON_VAR_LAMBDA_PARAMETER.allowedInSource(source) ||
3626 ((s.flags() & Flags.LAMBDA_PARAMETER) == 0))) {
3627 //cannot type annotate implicitly typed locals
3628 continue;
3629 } else if (s.kind == TYP || s.kind == VAR ||
3630 (s.kind == MTH && !s.isConstructor() &&
3631 !s.type.getReturnType().hasTag(VOID)) ||
3632 (s.kind == MTH && s.isConstructor())) {
3633 applicableTargets.add(names.TYPE_USE);
3634 }
3635 } else if (target == names.TYPE_PARAMETER) {
3636 if (s.kind == TYP && s.type.hasTag(TYPEVAR))
3637 applicableTargets.add(names.TYPE_PARAMETER);
3638 } else if (target == names.MODULE) {
3639 if (s.kind == MDL)
3640 applicableTargets.add(names.MODULE);
3641 } else {
3642 log.error(a, Errors.AnnotationUnrecognizedAttributeName(a.type, target));
3643 return Optional.empty(); // Unknown ElementType
3644 }
3645 }
3646 return Optional.of(applicableTargets);
3647 }
3648
3649 Attribute.Array getAttributeTargetAttribute(TypeSymbol s) {
3650 Attribute.Compound atTarget = s.getAnnotationTypeMetadata().getTarget();
3651 if (atTarget == null) return null; // ok, is applicable
3652 Attribute atValue = atTarget.member(names.value);
3653 return (atValue instanceof Attribute.Array attributeArray) ? attributeArray : null;
3654 }
3655
3656 private Name[] dfltTargetMeta;
3657 private Name[] defaultTargetMetaInfo() {
3658 if (dfltTargetMeta == null) {
3659 ArrayList<Name> defaultTargets = new ArrayList<>();
3660 defaultTargets.add(names.PACKAGE);
3661 defaultTargets.add(names.TYPE);
3662 defaultTargets.add(names.FIELD);
3663 defaultTargets.add(names.METHOD);
3664 defaultTargets.add(names.CONSTRUCTOR);
3665 defaultTargets.add(names.ANNOTATION_TYPE);
3666 defaultTargets.add(names.LOCAL_VARIABLE);
3667 defaultTargets.add(names.PARAMETER);
3668 if (allowRecords) {
3669 defaultTargets.add(names.RECORD_COMPONENT);
3670 }
3671 if (allowModules) {
3672 defaultTargets.add(names.MODULE);
3673 }
3674 dfltTargetMeta = defaultTargets.toArray(new Name[0]);
3675 }
3676 return dfltTargetMeta;
3677 }
3678
3679 /** Check an annotation value.
3680 *
3681 * @param a The annotation tree to check
3682 * @return true if this annotation tree is valid, otherwise false
3683 */
3684 public boolean validateAnnotationDeferErrors(JCAnnotation a) {
3685 boolean res = false;
3686 final Log.DiagnosticHandler diagHandler = log.new DiscardDiagnosticHandler();
3687 try {
3688 res = validateAnnotation(a);
3689 } finally {
3690 log.popDiagnosticHandler(diagHandler);
3691 }
3692 return res;
3693 }
3694
3695 private boolean validateAnnotation(JCAnnotation a) {
3696 boolean isValid = true;
3697 AnnotationTypeMetadata metadata = a.annotationType.type.tsym.getAnnotationTypeMetadata();
3698
3699 // collect an inventory of the annotation elements
3700 Set<MethodSymbol> elements = metadata.getAnnotationElements();
3701
3702 // remove the ones that are assigned values
3703 for (JCTree arg : a.args) {
3704 if (!arg.hasTag(ASSIGN)) continue; // recovery
3705 JCAssign assign = (JCAssign)arg;
3706 Symbol m = TreeInfo.symbol(assign.lhs);
3707 if (m == null || m.type.isErroneous()) continue;
3708 if (!elements.remove(m)) {
3709 isValid = false;
3710 log.error(assign.lhs.pos(),
3711 Errors.DuplicateAnnotationMemberValue(m.name, a.type));
3712 }
3713 }
3714
3715 // all the remaining ones better have default values
3716 List<Name> missingDefaults = List.nil();
3717 Set<MethodSymbol> membersWithDefault = metadata.getAnnotationElementsWithDefault();
3718 for (MethodSymbol m : elements) {
3719 if (m.type.isErroneous())
3720 continue;
3721
3722 if (!membersWithDefault.contains(m))
3723 missingDefaults = missingDefaults.append(m.name);
3724 }
3725 missingDefaults = missingDefaults.reverse();
3726 if (missingDefaults.nonEmpty()) {
3727 isValid = false;
3728 Error errorKey = (missingDefaults.size() > 1)
3729 ? Errors.AnnotationMissingDefaultValue1(a.type, missingDefaults)
3730 : Errors.AnnotationMissingDefaultValue(a.type, missingDefaults);
3731 log.error(a.pos(), errorKey);
3732 }
3733
3734 return isValid && validateTargetAnnotationValue(a);
3735 }
3736
3737 /* Validate the special java.lang.annotation.Target annotation */
3738 boolean validateTargetAnnotationValue(JCAnnotation a) {
3739 // special case: java.lang.annotation.Target must not have
3740 // repeated values in its value member
3741 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
3742 a.args.tail == null)
3743 return true;
3744
3745 boolean isValid = true;
3746 if (!a.args.head.hasTag(ASSIGN)) return false; // error recovery
3747 JCAssign assign = (JCAssign) a.args.head;
3748 Symbol m = TreeInfo.symbol(assign.lhs);
3749 if (m.name != names.value) return false;
3750 JCTree rhs = assign.rhs;
3751 if (!rhs.hasTag(NEWARRAY)) return false;
3752 JCNewArray na = (JCNewArray) rhs;
3753 Set<Symbol> targets = new HashSet<>();
3754 for (JCTree elem : na.elems) {
3755 if (!targets.add(TreeInfo.symbol(elem))) {
3756 isValid = false;
3757 log.error(elem.pos(), Errors.RepeatedAnnotationTarget);
3758 }
3759 }
3760 return isValid;
3761 }
3762
3763 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
3764 if (lint.isEnabled(LintCategory.DEP_ANN) && s.isDeprecatableViaAnnotation() &&
3765 (s.flags() & DEPRECATED) != 0 &&
3766 !syms.deprecatedType.isErroneous() &&
3767 s.attribute(syms.deprecatedType.tsym) == null) {
3768 log.warning(pos, LintWarnings.MissingDeprecatedAnnotation);
3769 }
3770 // Note: @Deprecated has no effect on local variables, parameters and package decls.
3771 if (lint.isEnabled(LintCategory.DEPRECATION) && !s.isDeprecatableViaAnnotation() &&
3772 (s.flags() & RECORD) == 0 &&
3773 !syms.deprecatedType.isErroneous() &&
3774 s.attribute(syms.deprecatedType.tsym) != null) {
3775 log.warning(pos, LintWarnings.DeprecatedAnnotationHasNoEffect(Kinds.kindName(s)));
3776 }
3777 }
3778
3779 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
3780 checkDeprecated(() -> pos, other, s);
3781 }
3782
3783 void checkDeprecated(Supplier<DiagnosticPosition> pos, final Symbol other, final Symbol s) {
3784 if (!importSuppression
3785 && (s.isDeprecatedForRemoval() || s.isDeprecated() && !other.isDeprecated())
3786 && (s.outermostClass() != other.outermostClass() || s.outermostClass() == null)
3787 && s.kind != Kind.PCK) {
3788 warnDeprecated(pos.get(), s);
3789 }
3790 }
3791
3792 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
3793 if ((s.flags() & PROPRIETARY) != 0) {
3794 log.warning(pos, Warnings.SunProprietary(s));
3795 }
3796 }
3797
3798 void checkProfile(final DiagnosticPosition pos, final Symbol s) {
3799 if (profile != Profile.DEFAULT && (s.flags() & NOT_IN_PROFILE) != 0) {
3800 log.error(pos, Errors.NotInProfile(s, profile));
3801 }
3802 }
3803
3804 void checkPreview(DiagnosticPosition pos, Symbol other, Symbol s) {
3805 checkPreview(pos, other, Type.noType, s);
3806 }
3807
3808 void checkPreview(DiagnosticPosition pos, Symbol other, Type site, Symbol s) {
3809 boolean sIsPreview;
3810 Symbol previewSymbol;
3811 if ((s.flags() & PREVIEW_API) != 0) {
3812 sIsPreview = true;
3813 previewSymbol= s;
3814 } else if ((s.kind == Kind.MTH || s.kind == Kind.VAR) &&
3815 site.tsym != null &&
3816 (site.tsym.flags() & PREVIEW_API) == 0 &&
3817 (s.owner.flags() & PREVIEW_API) != 0) {
3818 //calling a method, or using a field, whose owner is a preview, but
3819 //using a site that is not a preview. Also produce an error or warning:
3820 sIsPreview = true;
3821 previewSymbol = s.owner;
3822 } else {
3823 sIsPreview = false;
3824 previewSymbol = null;
3825 }
3826 if (sIsPreview && !preview.participatesInPreview(syms, other, s) && !disablePreviewCheck) {
3827 if ((previewSymbol.flags() & PREVIEW_REFLECTIVE) == 0) {
3828 if (!preview.isEnabled()) {
3829 log.error(pos, Errors.IsPreview(s));
3830 } else {
3831 preview.markUsesPreview(pos);
3832 warnPreviewAPI(pos, LintWarnings.IsPreview(s));
3833 }
3834 } else {
3835 warnPreviewAPI(pos, LintWarnings.IsPreviewReflective(s));
3836 }
3837 }
3838 if (preview.declaredUsingPreviewFeature(s)) {
3839 if (preview.isEnabled()) {
3840 //for preview disabled do presumably so not need to do anything?
3841 //If "s" is compiled from source, then there was an error for it already;
3842 //if "s" is from classfile, there already was an error for the classfile.
3843 preview.markUsesPreview(pos);
3844 warnPreviewAPI(pos, LintWarnings.DeclaredUsingPreview(kindName(s), s));
3845 }
3846 }
3847 }
3848
3849 void checkRestricted(DiagnosticPosition pos, Symbol s) {
3850 if (s.kind == MTH && (s.flags() & RESTRICTED) != 0) {
3851 log.warning(pos, LintWarnings.RestrictedMethod(s.enclClass(), s));
3852 }
3853 }
3854
3855 /* *************************************************************************
3856 * Check for recursive annotation elements.
3857 **************************************************************************/
3858
3859 /** Check for cycles in the graph of annotation elements.
3860 */
3861 void checkNonCyclicElements(JCClassDecl tree) {
3862 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
3863 Assert.check((tree.sym.flags_field & LOCKED) == 0);
3864 try {
3865 tree.sym.flags_field |= LOCKED;
3866 for (JCTree def : tree.defs) {
3867 if (!def.hasTag(METHODDEF)) continue;
3868 JCMethodDecl meth = (JCMethodDecl)def;
3869 checkAnnotationResType(meth.pos(), meth.restype.type);
3870 }
3871 } finally {
3872 tree.sym.flags_field &= ~LOCKED;
3873 tree.sym.flags_field |= ACYCLIC_ANN;
3874 }
3875 }
3876
3877 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
3878 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
3879 return;
3880 if ((tsym.flags_field & LOCKED) != 0) {
3881 log.error(pos, Errors.CyclicAnnotationElement(tsym));
3882 return;
3883 }
3884 try {
3885 tsym.flags_field |= LOCKED;
3886 for (Symbol s : tsym.members().getSymbols(NON_RECURSIVE)) {
3887 if (s.kind != MTH)
3888 continue;
3889 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
3890 }
3891 } finally {
3892 tsym.flags_field &= ~LOCKED;
3893 tsym.flags_field |= ACYCLIC_ANN;
3894 }
3895 }
3896
3897 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
3898 switch (type.getTag()) {
3899 case CLASS:
3900 if ((type.tsym.flags() & ANNOTATION) != 0)
3901 checkNonCyclicElementsInternal(pos, type.tsym);
3902 break;
3903 case ARRAY:
3904 checkAnnotationResType(pos, types.elemtype(type));
3905 break;
3906 default:
3907 break; // int etc
3908 }
3909 }
3910
3911 /* *************************************************************************
3912 * Check for cycles in the constructor call graph.
3913 **************************************************************************/
3914
3915 /** Check for cycles in the graph of constructors calling other
3916 * constructors.
3917 */
3918 void checkCyclicConstructors(JCClassDecl tree) {
3919 // use LinkedHashMap so we generate errors deterministically
3920 Map<Symbol,Symbol> callMap = new LinkedHashMap<>();
3921
3922 // enter each constructor this-call into the map
3923 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3924 if (!TreeInfo.isConstructor(l.head))
3925 continue;
3926 JCMethodDecl meth = (JCMethodDecl)l.head;
3927 JCMethodInvocation app = TreeInfo.findConstructorCall(meth);
3928 if (app != null && TreeInfo.name(app.meth) == names._this) {
3929 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
3930 } else {
3931 meth.sym.flags_field |= ACYCLIC;
3932 }
3933 }
3934
3935 // Check for cycles in the map
3936 Symbol[] ctors = new Symbol[0];
3937 ctors = callMap.keySet().toArray(ctors);
3938 for (Symbol caller : ctors) {
3939 checkCyclicConstructor(tree, caller, callMap);
3940 }
3941 }
3942
3943 /** Look in the map to see if the given constructor is part of a
3944 * call cycle.
3945 */
3946 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
3947 Map<Symbol,Symbol> callMap) {
3948 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
3949 if ((ctor.flags_field & LOCKED) != 0) {
3950 log.error(TreeInfo.diagnosticPositionFor(ctor, tree, false, t -> t.hasTag(IDENT)),
3951 Errors.RecursiveCtorInvocation);
3952 } else {
3953 ctor.flags_field |= LOCKED;
3954 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
3955 ctor.flags_field &= ~LOCKED;
3956 }
3957 ctor.flags_field |= ACYCLIC;
3958 }
3959 }
3960
3961 /* *************************************************************************
3962 * Verify the proper placement of super()/this() calls.
3963 *
3964 * - super()/this() may only appear in constructors
3965 * - There must be at most one super()/this() call per constructor
3966 * - The super()/this() call, if any, must be a top-level statement in the
3967 * constructor, i.e., not nested inside any other statement or block
3968 * - There must be no return statements prior to the super()/this() call
3969 **************************************************************************/
3970
3971 void checkSuperInitCalls(JCClassDecl tree) {
3972 new SuperThisChecker().check(tree);
3973 }
3974
3975 private class SuperThisChecker extends TreeScanner {
3976
3977 // Match this scan stack: 1=JCMethodDecl, 2=JCExpressionStatement, 3=JCMethodInvocation
3978 private static final int MATCH_SCAN_DEPTH = 3;
3979
3980 private boolean constructor; // is this method a constructor?
3981 private boolean firstStatement; // at the first statement in method?
3982 private JCReturn earlyReturn; // first return prior to the super()/init(), if any
3983 private Name initCall; // whichever of "super" or "init" we've seen already
3984 private int scanDepth; // current scan recursion depth in method body
3985
3986 public void check(JCClassDecl classDef) {
3987 scan(classDef.defs);
3988 }
3989
3990 @Override
3991 public void visitMethodDef(JCMethodDecl tree) {
3992 Assert.check(!constructor);
3993 Assert.check(earlyReturn == null);
3994 Assert.check(initCall == null);
3995 Assert.check(scanDepth == 1);
3996
3997 // Initialize state for this method
3998 constructor = TreeInfo.isConstructor(tree);
3999 try {
4000
4001 // Scan method body
4002 if (tree.body != null) {
4003 firstStatement = true;
4004 for (List<JCStatement> l = tree.body.stats; l.nonEmpty(); l = l.tail) {
4005 scan(l.head);
4006 firstStatement = false;
4007 }
4008 }
4009
4010 // Verify no 'return' seen prior to an explicit super()/this() call
4011 if (constructor && earlyReturn != null && initCall != null)
4012 log.error(earlyReturn.pos(), Errors.ReturnBeforeSuperclassInitialized);
4013 } finally {
4014 firstStatement = false;
4015 constructor = false;
4016 earlyReturn = null;
4017 initCall = null;
4018 }
4019 }
4020
4021 @Override
4022 public void scan(JCTree tree) {
4023 scanDepth++;
4024 try {
4025 super.scan(tree);
4026 } finally {
4027 scanDepth--;
4028 }
4029 }
4030
4031 @Override
4032 public void visitApply(JCMethodInvocation apply) {
4033 do {
4034
4035 // Is this a super() or this() call?
4036 Name methodName = TreeInfo.name(apply.meth);
4037 if (methodName != names._super && methodName != names._this)
4038 break;
4039
4040 // super()/this() calls must only appear in a constructor
4041 if (!constructor) {
4042 log.error(apply.pos(), Errors.CallMustOnlyAppearInCtor);
4043 break;
4044 }
4045
4046 // super()/this() calls must be a top level statement
4047 if (scanDepth != MATCH_SCAN_DEPTH) {
4048 log.error(apply.pos(), Errors.CtorCallsNotAllowedHere);
4049 break;
4050 }
4051
4052 // super()/this() calls must not appear more than once
4053 if (initCall != null) {
4054 log.error(apply.pos(), Errors.RedundantSuperclassInit);
4055 break;
4056 }
4057
4058 // If super()/this() isn't first, require flexible constructors feature
4059 if (!firstStatement)
4060 preview.checkSourceLevel(apply.pos(), Feature.FLEXIBLE_CONSTRUCTORS);
4061
4062 // We found a legitimate super()/this() call; remember it
4063 initCall = methodName;
4064 } while (false);
4065
4066 // Proceed
4067 super.visitApply(apply);
4068 }
4069
4070 @Override
4071 public void visitReturn(JCReturn tree) {
4072 if (constructor && initCall == null && earlyReturn == null)
4073 earlyReturn = tree; // we have seen a return but not (yet) a super()/this()
4074 super.visitReturn(tree);
4075 }
4076
4077 @Override
4078 public void visitClassDef(JCClassDecl tree) {
4079 // don't descend any further
4080 }
4081
4082 @Override
4083 public void visitLambda(JCLambda tree) {
4084 final boolean constructorPrev = constructor;
4085 final boolean firstStatementPrev = firstStatement;
4086 final JCReturn earlyReturnPrev = earlyReturn;
4087 final Name initCallPrev = initCall;
4088 final int scanDepthPrev = scanDepth;
4089 constructor = false;
4090 firstStatement = false;
4091 earlyReturn = null;
4092 initCall = null;
4093 scanDepth = 0;
4094 try {
4095 super.visitLambda(tree);
4096 } finally {
4097 constructor = constructorPrev;
4098 firstStatement = firstStatementPrev;
4099 earlyReturn = earlyReturnPrev;
4100 initCall = initCallPrev;
4101 scanDepth = scanDepthPrev;
4102 }
4103 }
4104 }
4105
4106 /* *************************************************************************
4107 * Miscellaneous
4108 **************************************************************************/
4109
4110 /**
4111 * Check for division by integer constant zero
4112 * @param pos Position for error reporting.
4113 * @param operator The operator for the expression
4114 * @param operand The right hand operand for the expression
4115 */
4116 void checkDivZero(final DiagnosticPosition pos, Symbol operator, Type operand) {
4117 if (operand.constValue() != null
4118 && operand.getTag().isSubRangeOf(LONG)
4119 && ((Number) (operand.constValue())).longValue() == 0) {
4120 int opc = ((OperatorSymbol)operator).opcode;
4121 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
4122 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
4123 log.warning(pos, LintWarnings.DivZero);
4124 }
4125 }
4126 }
4127
4128 /**
4129 * Check for bit shifts using an out-of-range bit count.
4130 * @param pos Position for error reporting.
4131 * @param operator The operator for the expression
4132 * @param operand The right hand operand for the expression
4133 */
4134 void checkOutOfRangeShift(final DiagnosticPosition pos, Symbol operator, Type operand) {
4135 if (operand.constValue() instanceof Number shiftAmount) {
4136 Type targetType;
4137 int maximumShift;
4138 switch (((OperatorSymbol)operator).opcode) {
4139 case ByteCodes.ishl, ByteCodes.ishr, ByteCodes.iushr, ByteCodes.ishll, ByteCodes.ishrl, ByteCodes.iushrl -> {
4140 targetType = syms.intType;
4141 maximumShift = 0x1f;
4142 }
4143 case ByteCodes.lshl, ByteCodes.lshr, ByteCodes.lushr, ByteCodes.lshll, ByteCodes.lshrl, ByteCodes.lushrl -> {
4144 targetType = syms.longType;
4145 maximumShift = 0x3f;
4146 }
4147 default -> {
4148 return;
4149 }
4150 }
4151 long specifiedShift = shiftAmount.longValue();
4152 if (specifiedShift > maximumShift || specifiedShift < -maximumShift) {
4153 int actualShift = (int)specifiedShift & (maximumShift - 1);
4154 log.warning(pos, LintWarnings.BitShiftOutOfRange(targetType, specifiedShift, actualShift));
4155 }
4156 }
4157 }
4158
4159 /**
4160 * Check for possible loss of precission
4161 * @param pos Position for error reporting.
4162 * @param found The computed type of the tree
4163 * @param req The computed type of the tree
4164 */
4165 void checkLossOfPrecision(final DiagnosticPosition pos, Type found, Type req) {
4166 if (found.isNumeric() && req.isNumeric() && !types.isAssignable(found, req)) {
4167 log.warning(pos, LintWarnings.PossibleLossOfPrecision(found, req));
4168 }
4169 }
4170
4171 /**
4172 * Check for empty statements after if
4173 */
4174 void checkEmptyIf(JCIf tree) {
4175 if (tree.thenpart.hasTag(SKIP) && tree.elsepart == null) {
4176 log.warning(tree.thenpart.pos(), LintWarnings.EmptyIf);
4177 }
4178 }
4179
4180 /** Check that symbol is unique in given scope.
4181 * @param pos Position for error reporting.
4182 * @param sym The symbol.
4183 * @param s The scope.
4184 */
4185 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
4186 if (sym.type.isErroneous())
4187 return true;
4188 if (sym.owner.name == names.any) return false;
4189 for (Symbol byName : s.getSymbolsByName(sym.name, NON_RECURSIVE)) {
4190 if (sym != byName &&
4191 (byName.flags() & CLASH) == 0 &&
4192 sym.kind == byName.kind &&
4193 sym.name != names.error &&
4194 (sym.kind != MTH ||
4195 types.hasSameArgs(sym.type, byName.type) ||
4196 types.hasSameArgs(types.erasure(sym.type), types.erasure(byName.type)))) {
4197 if ((sym.flags() & VARARGS) != (byName.flags() & VARARGS)) {
4198 sym.flags_field |= CLASH;
4199 varargsDuplicateError(pos, sym, byName);
4200 return true;
4201 } else if (sym.kind == MTH && !types.hasSameArgs(sym.type, byName.type, false)) {
4202 duplicateErasureError(pos, sym, byName);
4203 sym.flags_field |= CLASH;
4204 return true;
4205 } else if ((sym.flags() & MATCH_BINDING) != 0 &&
4206 (byName.flags() & MATCH_BINDING) != 0 &&
4207 (byName.flags() & MATCH_BINDING_TO_OUTER) == 0) {
4208 if (!sym.type.isErroneous()) {
4209 log.error(pos, Errors.MatchBindingExists);
4210 sym.flags_field |= CLASH;
4211 }
4212 return false;
4213 } else {
4214 duplicateError(pos, byName);
4215 return false;
4216 }
4217 }
4218 }
4219 return true;
4220 }
4221
4222 /** Report duplicate declaration error.
4223 */
4224 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
4225 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
4226 log.error(pos, Errors.NameClashSameErasure(sym1, sym2));
4227 }
4228 }
4229
4230 /**Check that types imported through the ordinary imports don't clash with types imported
4231 * by other (static or ordinary) imports. Note that two static imports may import two clashing
4232 * types without an error on the imports.
4233 * @param toplevel The toplevel tree for which the test should be performed.
4234 */
4235 void checkImportsUnique(JCCompilationUnit toplevel) {
4236 WriteableScope ordinallyImportedSoFar = WriteableScope.create(toplevel.packge);
4237 WriteableScope staticallyImportedSoFar = WriteableScope.create(toplevel.packge);
4238 WriteableScope topLevelScope = toplevel.toplevelScope;
4239
4240 for (JCTree def : toplevel.defs) {
4241 if (!def.hasTag(IMPORT))
4242 continue;
4243
4244 JCImport imp = (JCImport) def;
4245
4246 if (imp.importScope == null)
4247 continue;
4248
4249 for (Symbol sym : imp.importScope.getSymbols(sym -> sym.kind == TYP)) {
4250 if (imp.isStatic()) {
4251 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, true);
4252 staticallyImportedSoFar.enter(sym);
4253 } else {
4254 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, false);
4255 ordinallyImportedSoFar.enter(sym);
4256 }
4257 }
4258
4259 imp.importScope = null;
4260 }
4261 }
4262
4263 /** Check that single-type import is not already imported or top-level defined,
4264 * but make an exception for two single-type imports which denote the same type.
4265 * @param pos Position for error reporting.
4266 * @param ordinallyImportedSoFar A Scope containing types imported so far through
4267 * ordinary imports.
4268 * @param staticallyImportedSoFar A Scope containing types imported so far through
4269 * static imports.
4270 * @param topLevelScope The current file's top-level Scope
4271 * @param sym The symbol.
4272 * @param staticImport Whether or not this was a static import
4273 */
4274 private boolean checkUniqueImport(DiagnosticPosition pos, Scope ordinallyImportedSoFar,
4275 Scope staticallyImportedSoFar, Scope topLevelScope,
4276 Symbol sym, boolean staticImport) {
4277 Predicate<Symbol> duplicates = candidate -> candidate != sym && !candidate.type.isErroneous();
4278 Symbol ordinaryClashing = ordinallyImportedSoFar.findFirst(sym.name, duplicates);
4279 Symbol staticClashing = null;
4280 if (ordinaryClashing == null && !staticImport) {
4281 staticClashing = staticallyImportedSoFar.findFirst(sym.name, duplicates);
4282 }
4283 if (ordinaryClashing != null || staticClashing != null) {
4284 if (ordinaryClashing != null)
4285 log.error(pos, Errors.AlreadyDefinedSingleImport(ordinaryClashing));
4286 else
4287 log.error(pos, Errors.AlreadyDefinedStaticSingleImport(staticClashing));
4288 return false;
4289 }
4290 Symbol clashing = topLevelScope.findFirst(sym.name, duplicates);
4291 if (clashing != null) {
4292 log.error(pos, Errors.AlreadyDefinedThisUnit(clashing));
4293 return false;
4294 }
4295 return true;
4296 }
4297
4298 /** Check that a qualified name is in canonical form (for import decls).
4299 */
4300 public void checkCanonical(JCTree tree) {
4301 if (!isCanonical(tree))
4302 log.error(tree.pos(),
4303 Errors.ImportRequiresCanonical(TreeInfo.symbol(tree)));
4304 }
4305 // where
4306 private boolean isCanonical(JCTree tree) {
4307 while (tree.hasTag(SELECT)) {
4308 JCFieldAccess s = (JCFieldAccess) tree;
4309 if (s.sym.owner.getQualifiedName() != TreeInfo.symbol(s.selected).getQualifiedName())
4310 return false;
4311 tree = s.selected;
4312 }
4313 return true;
4314 }
4315
4316 /** Check that an auxiliary class is not accessed from any other file than its own.
4317 */
4318 void checkForBadAuxiliaryClassAccess(DiagnosticPosition pos, Env<AttrContext> env, ClassSymbol c) {
4319 if ((c.flags() & AUXILIARY) != 0 &&
4320 rs.isAccessible(env, c) &&
4321 !fileManager.isSameFile(c.sourcefile, env.toplevel.sourcefile))
4322 {
4323 log.warning(pos, LintWarnings.AuxiliaryClassAccessedFromOutsideOfItsSourceFile(c, c.sourcefile));
4324 }
4325 }
4326
4327 /**
4328 * Check for a default constructor in an exported package.
4329 */
4330 void checkDefaultConstructor(ClassSymbol c, DiagnosticPosition pos) {
4331 if (lint.isEnabled(LintCategory.MISSING_EXPLICIT_CTOR) &&
4332 ((c.flags() & (ENUM | RECORD)) == 0) &&
4333 !c.isAnonymous() &&
4334 ((c.flags() & (PUBLIC | PROTECTED)) != 0) &&
4335 Feature.MODULES.allowedInSource(source)) {
4336 NestingKind nestingKind = c.getNestingKind();
4337 switch (nestingKind) {
4338 case ANONYMOUS,
4339 LOCAL -> {return;}
4340 case TOP_LEVEL -> {;} // No additional checks needed
4341 case MEMBER -> {
4342 // For nested member classes, all the enclosing
4343 // classes must be public or protected.
4344 Symbol owner = c.owner;
4345 while (owner != null && owner.kind == TYP) {
4346 if ((owner.flags() & (PUBLIC | PROTECTED)) == 0)
4347 return;
4348 owner = owner.owner;
4349 }
4350 }
4351 }
4352
4353 // Only check classes in named packages exported by its module
4354 PackageSymbol pkg = c.packge();
4355 if (!pkg.isUnnamed()) {
4356 ModuleSymbol modle = pkg.modle;
4357 for (ExportsDirective exportDir : modle.exports) {
4358 // Report warning only if the containing
4359 // package is unconditionally exported
4360 if (exportDir.packge.equals(pkg)) {
4361 if (exportDir.modules == null || exportDir.modules.isEmpty()) {
4362 // Warning may be suppressed by
4363 // annotations; check again for being
4364 // enabled in the deferred context.
4365 log.warning(pos, LintWarnings.MissingExplicitCtor(c, pkg, modle));
4366 } else {
4367 return;
4368 }
4369 }
4370 }
4371 }
4372 }
4373 return;
4374 }
4375
4376 private class ConversionWarner extends Warner {
4377 final String uncheckedKey;
4378 final Type found;
4379 final Type expected;
4380 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
4381 super(pos);
4382 this.uncheckedKey = uncheckedKey;
4383 this.found = found;
4384 this.expected = expected;
4385 }
4386
4387 @Override
4388 public void warn(LintCategory lint) {
4389 boolean warned = this.warned;
4390 super.warn(lint);
4391 if (warned) return; // suppress redundant diagnostics
4392 switch (lint) {
4393 case UNCHECKED:
4394 Check.this.warnUnchecked(pos(), LintWarnings.ProbFoundReq(diags.fragment(uncheckedKey), found, expected));
4395 break;
4396 case VARARGS:
4397 if (method != null &&
4398 method.attribute(syms.trustMeType.tsym) != null &&
4399 isTrustMeAllowedOnMethod(method) &&
4400 !types.isReifiable(method.type.getParameterTypes().last())) {
4401 log.warning(pos(), LintWarnings.VarargsUnsafeUseVarargsParam(method.params.last()));
4402 }
4403 break;
4404 default:
4405 throw new AssertionError("Unexpected lint: " + lint);
4406 }
4407 }
4408 }
4409
4410 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
4411 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
4412 }
4413
4414 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
4415 return new ConversionWarner(pos, "unchecked.assign", found, expected);
4416 }
4417
4418 public void checkFunctionalInterface(JCClassDecl tree, ClassSymbol cs) {
4419 Compound functionalType = cs.attribute(syms.functionalInterfaceType.tsym);
4420
4421 if (functionalType != null) {
4422 try {
4423 types.findDescriptorSymbol((TypeSymbol)cs);
4424 } catch (Types.FunctionDescriptorLookupError ex) {
4425 DiagnosticPosition pos = tree.pos();
4426 for (JCAnnotation a : tree.getModifiers().annotations) {
4427 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
4428 pos = a.pos();
4429 break;
4430 }
4431 }
4432 log.error(pos, Errors.BadFunctionalIntfAnno1(ex.getDiagnostic()));
4433 }
4434 }
4435 }
4436
4437 public void checkImportsResolvable(final JCCompilationUnit toplevel) {
4438 for (final JCImportBase impBase : toplevel.getImports()) {
4439 if (!(impBase instanceof JCImport imp))
4440 continue;
4441 if (!imp.staticImport || !imp.qualid.hasTag(SELECT))
4442 continue;
4443 final JCFieldAccess select = imp.qualid;
4444 final Symbol origin;
4445 if (select.name == names.asterisk || (origin = TreeInfo.symbol(select.selected)) == null || origin.kind != TYP)
4446 continue;
4447
4448 TypeSymbol site = (TypeSymbol) TreeInfo.symbol(select.selected);
4449 if (!checkTypeContainsImportableElement(site, site, toplevel.packge, select.name, new HashSet<Symbol>())) {
4450 log.error(imp.pos(),
4451 Errors.CantResolveLocation(KindName.STATIC,
4452 select.name,
4453 null,
4454 null,
4455 Fragments.Location(kindName(site),
4456 site,
4457 null)));
4458 }
4459 }
4460 }
4461
4462 // Check that packages imported are in scope (JLS 7.4.3, 6.3, 6.5.3.1, 6.5.3.2)
4463 public void checkImportedPackagesObservable(final JCCompilationUnit toplevel) {
4464 OUTER: for (JCImportBase impBase : toplevel.getImports()) {
4465 if (impBase instanceof JCImport imp && !imp.staticImport &&
4466 TreeInfo.name(imp.qualid) == names.asterisk) {
4467 TypeSymbol tsym = imp.qualid.selected.type.tsym;
4468 if (tsym.kind == PCK && tsym.members().isEmpty() &&
4469 !(Feature.IMPORT_ON_DEMAND_OBSERVABLE_PACKAGES.allowedInSource(source) && tsym.exists())) {
4470 log.error(DiagnosticFlag.RESOLVE_ERROR, imp.qualid.selected.pos(), Errors.DoesntExist(tsym));
4471 }
4472 }
4473 }
4474 }
4475
4476 private boolean checkTypeContainsImportableElement(TypeSymbol tsym, TypeSymbol origin, PackageSymbol packge, Name name, Set<Symbol> processed) {
4477 if (tsym == null || !processed.add(tsym))
4478 return false;
4479
4480 // also search through inherited names
4481 if (checkTypeContainsImportableElement(types.supertype(tsym.type).tsym, origin, packge, name, processed))
4482 return true;
4483
4484 for (Type t : types.interfaces(tsym.type))
4485 if (checkTypeContainsImportableElement(t.tsym, origin, packge, name, processed))
4486 return true;
4487
4488 for (Symbol sym : tsym.members().getSymbolsByName(name)) {
4489 if (sym.isStatic() &&
4490 importAccessible(sym, packge) &&
4491 sym.isMemberOf(origin, types)) {
4492 return true;
4493 }
4494 }
4495
4496 return false;
4497 }
4498
4499 // is the sym accessible everywhere in packge?
4500 public boolean importAccessible(Symbol sym, PackageSymbol packge) {
4501 try {
4502 int flags = (int)(sym.flags() & AccessFlags);
4503 switch (flags) {
4504 default:
4505 case PUBLIC:
4506 return true;
4507 case PRIVATE:
4508 return false;
4509 case 0:
4510 case PROTECTED:
4511 return sym.packge() == packge;
4512 }
4513 } catch (ClassFinder.BadClassFile err) {
4514 throw err;
4515 } catch (CompletionFailure ex) {
4516 return false;
4517 }
4518 }
4519
4520 public void checkLeaksNotAccessible(Env<AttrContext> env, JCClassDecl check) {
4521 JCCompilationUnit toplevel = env.toplevel;
4522
4523 if ( toplevel.modle == syms.unnamedModule
4524 || toplevel.modle == syms.noModule
4525 || (check.sym.flags() & COMPOUND) != 0) {
4526 return ;
4527 }
4528
4529 ExportsDirective currentExport = findExport(toplevel.packge);
4530
4531 if ( currentExport == null //not exported
4532 || currentExport.modules != null) //don't check classes in qualified export
4533 return ;
4534
4535 new TreeScanner() {
4536 Lint lint = env.info.lint;
4537 boolean inSuperType;
4538
4539 @Override
4540 public void visitBlock(JCBlock tree) {
4541 }
4542 @Override
4543 public void visitMethodDef(JCMethodDecl tree) {
4544 if (!isAPISymbol(tree.sym))
4545 return;
4546 Lint prevLint = lint;
4547 try {
4548 lint = lint.augment(tree.sym);
4549 if (lint.isEnabled(LintCategory.EXPORTS)) {
4550 super.visitMethodDef(tree);
4551 }
4552 } finally {
4553 lint = prevLint;
4554 }
4555 }
4556 @Override
4557 public void visitVarDef(JCVariableDecl tree) {
4558 if (!isAPISymbol(tree.sym) && tree.sym.owner.kind != MTH)
4559 return;
4560 Lint prevLint = lint;
4561 try {
4562 lint = lint.augment(tree.sym);
4563 if (lint.isEnabled(LintCategory.EXPORTS)) {
4564 scan(tree.mods);
4565 scan(tree.vartype);
4566 }
4567 } finally {
4568 lint = prevLint;
4569 }
4570 }
4571 @Override
4572 public void visitClassDef(JCClassDecl tree) {
4573 if (tree != check)
4574 return ;
4575
4576 if (!isAPISymbol(tree.sym))
4577 return ;
4578
4579 Lint prevLint = lint;
4580 try {
4581 lint = lint.augment(tree.sym);
4582 if (lint.isEnabled(LintCategory.EXPORTS)) {
4583 scan(tree.mods);
4584 scan(tree.typarams);
4585 try {
4586 inSuperType = true;
4587 scan(tree.extending);
4588 scan(tree.implementing);
4589 } finally {
4590 inSuperType = false;
4591 }
4592 scan(tree.defs);
4593 }
4594 } finally {
4595 lint = prevLint;
4596 }
4597 }
4598 @Override
4599 public void visitTypeApply(JCTypeApply tree) {
4600 scan(tree.clazz);
4601 boolean oldInSuperType = inSuperType;
4602 try {
4603 inSuperType = false;
4604 scan(tree.arguments);
4605 } finally {
4606 inSuperType = oldInSuperType;
4607 }
4608 }
4609 @Override
4610 public void visitIdent(JCIdent tree) {
4611 Symbol sym = TreeInfo.symbol(tree);
4612 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR)) {
4613 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4614 }
4615 }
4616
4617 @Override
4618 public void visitSelect(JCFieldAccess tree) {
4619 Symbol sym = TreeInfo.symbol(tree);
4620 Symbol sitesym = TreeInfo.symbol(tree.selected);
4621 if (sym.kind == TYP && sitesym.kind == PCK) {
4622 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4623 } else {
4624 super.visitSelect(tree);
4625 }
4626 }
4627
4628 @Override
4629 public void visitAnnotation(JCAnnotation tree) {
4630 if (tree.attribute.type.tsym.getAnnotation(java.lang.annotation.Documented.class) != null)
4631 super.visitAnnotation(tree);
4632 }
4633
4634 }.scan(check);
4635 }
4636 //where:
4637 private ExportsDirective findExport(PackageSymbol pack) {
4638 for (ExportsDirective d : pack.modle.exports) {
4639 if (d.packge == pack)
4640 return d;
4641 }
4642
4643 return null;
4644 }
4645 private boolean isAPISymbol(Symbol sym) {
4646 while (sym.kind != PCK) {
4647 if ((sym.flags() & Flags.PUBLIC) == 0 && (sym.flags() & Flags.PROTECTED) == 0) {
4648 return false;
4649 }
4650 sym = sym.owner;
4651 }
4652 return true;
4653 }
4654 private void checkVisible(DiagnosticPosition pos, Symbol what, PackageSymbol inPackage, boolean inSuperType) {
4655 if (!isAPISymbol(what) && !inSuperType) { //package private/private element
4656 log.warning(pos, LintWarnings.LeaksNotAccessible(kindName(what), what, what.packge().modle));
4657 return ;
4658 }
4659
4660 PackageSymbol whatPackage = what.packge();
4661 ExportsDirective whatExport = findExport(whatPackage);
4662 ExportsDirective inExport = findExport(inPackage);
4663
4664 if (whatExport == null) { //package not exported:
4665 log.warning(pos, LintWarnings.LeaksNotAccessibleUnexported(kindName(what), what, what.packge().modle));
4666 return ;
4667 }
4668
4669 if (whatExport.modules != null) {
4670 if (inExport.modules == null || !whatExport.modules.containsAll(inExport.modules)) {
4671 log.warning(pos, LintWarnings.LeaksNotAccessibleUnexportedQualified(kindName(what), what, what.packge().modle));
4672 }
4673 }
4674
4675 if (whatPackage.modle != inPackage.modle && whatPackage.modle != syms.java_base) {
4676 //check that relativeTo.modle requires transitive what.modle, somehow:
4677 List<ModuleSymbol> todo = List.of(inPackage.modle);
4678
4679 while (todo.nonEmpty()) {
4680 ModuleSymbol current = todo.head;
4681 todo = todo.tail;
4682 if (current == whatPackage.modle)
4683 return ; //OK
4684 if ((current.flags() & Flags.AUTOMATIC_MODULE) != 0)
4685 continue; //for automatic modules, don't look into their dependencies
4686 for (RequiresDirective req : current.requires) {
4687 if (req.isTransitive()) {
4688 todo = todo.prepend(req.module);
4689 }
4690 }
4691 }
4692
4693 log.warning(pos, LintWarnings.LeaksNotAccessibleNotRequiredTransitive(kindName(what), what, what.packge().modle));
4694 }
4695 }
4696
4697 void checkModuleExists(final DiagnosticPosition pos, ModuleSymbol msym) {
4698 if (msym.kind != MDL) {
4699 log.warning(pos, LintWarnings.ModuleNotFound(msym));
4700 }
4701 }
4702
4703 void checkPackageExistsForOpens(final DiagnosticPosition pos, PackageSymbol packge) {
4704 if (packge.members().isEmpty() &&
4705 ((packge.flags() & Flags.HAS_RESOURCE) == 0)) {
4706 log.warning(pos, LintWarnings.PackageEmptyOrNotFound(packge));
4707 }
4708 }
4709
4710 void checkModuleRequires(final DiagnosticPosition pos, final RequiresDirective rd) {
4711 if ((rd.module.flags() & Flags.AUTOMATIC_MODULE) != 0) {
4712 if (rd.isTransitive()) { // see comment in Log.applyLint() for special logic that applies
4713 log.warning(pos, LintWarnings.RequiresTransitiveAutomatic);
4714 } else {
4715 log.warning(pos, LintWarnings.RequiresAutomatic);
4716 }
4717 }
4718 }
4719
4720 /**
4721 * Verify the case labels conform to the constraints. Checks constraints related
4722 * combinations of patterns and other labels.
4723 *
4724 * @param cases the cases that should be checked.
4725 */
4726 void checkSwitchCaseStructure(List<JCCase> cases) {
4727 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4728 JCCase c = l.head;
4729 if (c.labels.head instanceof JCConstantCaseLabel constLabel) {
4730 if (TreeInfo.isNull(constLabel.expr)) {
4731 if (c.labels.tail.nonEmpty()) {
4732 if (c.labels.tail.head instanceof JCDefaultCaseLabel defLabel) {
4733 if (c.labels.tail.tail.nonEmpty()) {
4734 log.error(c.labels.tail.tail.head.pos(), Errors.InvalidCaseLabelCombination);
4735 }
4736 } else {
4737 log.error(c.labels.tail.head.pos(), Errors.InvalidCaseLabelCombination);
4738 }
4739 }
4740 } else {
4741 for (JCCaseLabel label : c.labels.tail) {
4742 if (!(label instanceof JCConstantCaseLabel) || TreeInfo.isNullCaseLabel(label)) {
4743 log.error(label.pos(), Errors.InvalidCaseLabelCombination);
4744 break;
4745 }
4746 }
4747 }
4748 } else if (c.labels.tail.nonEmpty()) {
4749 var patterCaseLabels = c.labels.stream().filter(ll -> ll instanceof JCPatternCaseLabel).map(cl -> (JCPatternCaseLabel)cl);
4750 var allUnderscore = patterCaseLabels.allMatch(pcl -> !hasBindings(pcl.getPattern()));
4751
4752 if (!allUnderscore) {
4753 log.error(c.labels.tail.head.pos(), Errors.FlowsThroughFromPattern);
4754 }
4755
4756 boolean allPatternCaseLabels = c.labels.stream().allMatch(p -> p instanceof JCPatternCaseLabel);
4757
4758 if (allPatternCaseLabels) {
4759 preview.checkSourceLevel(c.labels.tail.head.pos(), Feature.UNNAMED_VARIABLES);
4760 }
4761
4762 for (JCCaseLabel label : c.labels.tail) {
4763 if (label instanceof JCConstantCaseLabel) {
4764 log.error(label.pos(), Errors.InvalidCaseLabelCombination);
4765 break;
4766 }
4767 }
4768 }
4769 }
4770
4771 boolean isCaseStatementGroup = cases.nonEmpty() &&
4772 cases.head.caseKind == CaseTree.CaseKind.STATEMENT;
4773
4774 if (isCaseStatementGroup) {
4775 boolean previousCompletessNormally = false;
4776 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4777 JCCase c = l.head;
4778 if (previousCompletessNormally &&
4779 c.stats.nonEmpty() &&
4780 c.labels.head instanceof JCPatternCaseLabel patternLabel &&
4781 (hasBindings(patternLabel.pat) || hasBindings(c.guard))) {
4782 log.error(c.labels.head.pos(), Errors.FlowsThroughToPattern);
4783 } else if (c.stats.isEmpty() &&
4784 c.labels.head instanceof JCPatternCaseLabel patternLabel &&
4785 (hasBindings(patternLabel.pat) || hasBindings(c.guard)) &&
4786 hasStatements(l.tail)) {
4787 log.error(c.labels.head.pos(), Errors.FlowsThroughFromPattern);
4788 }
4789 previousCompletessNormally = c.completesNormally;
4790 }
4791 }
4792 }
4793
4794 boolean hasBindings(JCTree p) {
4795 boolean[] bindings = new boolean[1];
4796
4797 new TreeScanner() {
4798 @Override
4799 public void visitBindingPattern(JCBindingPattern tree) {
4800 bindings[0] |= !tree.var.sym.isUnnamedVariable();
4801 super.visitBindingPattern(tree);
4802 }
4803 }.scan(p);
4804
4805 return bindings[0];
4806 }
4807
4808 boolean hasStatements(List<JCCase> cases) {
4809 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4810 if (l.head.stats.nonEmpty()) {
4811 return true;
4812 }
4813 }
4814
4815 return false;
4816 }
4817 void checkSwitchCaseLabelDominated(JCCaseLabel unconditionalCaseLabel, List<JCCase> cases) {
4818 List<Pair<JCCase, JCCaseLabel>> caseLabels = List.nil();
4819 boolean seenDefault = false;
4820 boolean seenDefaultLabel = false;
4821 boolean warnDominatedByDefault = false;
4822 boolean unconditionalFound = false;
4823
4824 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4825 JCCase c = l.head;
4826 for (JCCaseLabel label : c.labels) {
4827 if (label.hasTag(DEFAULTCASELABEL)) {
4828 seenDefault = true;
4829 seenDefaultLabel |=
4830 TreeInfo.isNullCaseLabel(c.labels.head);
4831 continue;
4832 }
4833 if (TreeInfo.isNullCaseLabel(label)) {
4834 if (seenDefault) {
4835 log.error(label.pos(), Errors.PatternDominated);
4836 }
4837 continue;
4838 }
4839 if (seenDefault && !warnDominatedByDefault) {
4840 if (label.hasTag(PATTERNCASELABEL) ||
4841 (label instanceof JCConstantCaseLabel && seenDefaultLabel)) {
4842 log.error(label.pos(), Errors.PatternDominated);
4843 warnDominatedByDefault = true;
4844 }
4845 }
4846 Type currentType = labelType(label);
4847 for (Pair<JCCase, JCCaseLabel> caseAndLabel : caseLabels) {
4848 JCCase testCase = caseAndLabel.fst;
4849 JCCaseLabel testCaseLabel = caseAndLabel.snd;
4850 Type testType = labelType(testCaseLabel);
4851
4852 // an unconditional pattern cannot be followed by any other label
4853 if (allowPrimitivePatterns && unconditionalCaseLabel == testCaseLabel && unconditionalCaseLabel != label) {
4854 log.error(label.pos(), Errors.PatternDominated);
4855 continue;
4856 }
4857
4858 boolean dominated = false;
4859 if (!currentType.hasTag(ERROR) && !testType.hasTag(ERROR)) {
4860 // the current label is potentially dominated by the existing (test) label, check:
4861 if (types.isUnconditionallyExactCombined(currentType, testType) &&
4862 label instanceof JCConstantCaseLabel) {
4863 dominated = !(testCaseLabel instanceof JCConstantCaseLabel) &&
4864 TreeInfo.unguardedCase(testCase);
4865 } else if (label instanceof JCPatternCaseLabel patternCL &&
4866 testCaseLabel instanceof JCPatternCaseLabel testPatternCaseLabel &&
4867 (testCase.equals(c) || TreeInfo.unguardedCase(testCase))) {
4868 dominated = patternDominated(testPatternCaseLabel.pat, patternCL.pat);
4869 }
4870 }
4871 if (dominated) {
4872 log.error(label.pos(), Errors.PatternDominated);
4873 }
4874 }
4875 caseLabels = caseLabels.prepend(Pair.of(c, label));
4876 }
4877 }
4878 }
4879 //where:
4880 private Type labelType(JCCaseLabel label) {
4881 return types.erasure(switch (label.getTag()) {
4882 case PATTERNCASELABEL -> ((JCPatternCaseLabel) label).pat.type;
4883 case CONSTANTCASELABEL -> ((JCConstantCaseLabel) label).expr.type;
4884 default -> throw Assert.error("Unexpected tree kind: " + label.getTag());
4885 });
4886 }
4887 private boolean patternDominated(JCPattern existingPattern, JCPattern currentPattern) {
4888 Type existingPatternType = types.erasure(existingPattern.type);
4889 Type currentPatternType = types.erasure(currentPattern.type);
4890 if (!types.isUnconditionallyExactTypeBased(currentPatternType, existingPatternType)) {
4891 return false;
4892 }
4893 if (currentPattern instanceof JCBindingPattern ||
4894 currentPattern instanceof JCAnyPattern) {
4895 return existingPattern instanceof JCBindingPattern ||
4896 existingPattern instanceof JCAnyPattern;
4897 } else if (currentPattern instanceof JCRecordPattern currentRecordPattern) {
4898 if (existingPattern instanceof JCBindingPattern ||
4899 existingPattern instanceof JCAnyPattern) {
4900 return true;
4901 } else if (existingPattern instanceof JCRecordPattern existingRecordPattern) {
4902 List<JCPattern> existingNested = existingRecordPattern.nested;
4903 List<JCPattern> currentNested = currentRecordPattern.nested;
4904 if (existingNested.size() != currentNested.size()) {
4905 return false;
4906 }
4907 while (existingNested.nonEmpty()) {
4908 if (!patternDominated(existingNested.head, currentNested.head)) {
4909 return false;
4910 }
4911 existingNested = existingNested.tail;
4912 currentNested = currentNested.tail;
4913 }
4914 return true;
4915 } else {
4916 Assert.error("Unknown pattern: " + existingPattern.getTag());
4917 }
4918 } else {
4919 Assert.error("Unknown pattern: " + currentPattern.getTag());
4920 }
4921 return false;
4922 }
4923
4924 /** check if a type is a subtype of Externalizable, if that is available. */
4925 boolean isExternalizable(Type t) {
4926 try {
4927 syms.externalizableType.complete();
4928 } catch (CompletionFailure e) {
4929 return false;
4930 }
4931 return types.isSubtype(t, syms.externalizableType);
4932 }
4933
4934 /**
4935 * Check structure of serialization declarations.
4936 */
4937 public void checkSerialStructure(Env<AttrContext> env, JCClassDecl tree, ClassSymbol c) {
4938 (new SerialTypeVisitor(env)).visit(c, tree);
4939 }
4940
4941 /**
4942 * This visitor will warn if a serialization-related field or
4943 * method is declared in a suspicious or incorrect way. In
4944 * particular, it will warn for cases where the runtime
4945 * serialization mechanism will silently ignore a mis-declared
4946 * entity.
4947 *
4948 * Distinguished serialization-related fields and methods:
4949 *
4950 * Methods:
4951 *
4952 * private void writeObject(ObjectOutputStream stream) throws IOException
4953 * ANY-ACCESS-MODIFIER Object writeReplace() throws ObjectStreamException
4954 *
4955 * private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException
4956 * private void readObjectNoData() throws ObjectStreamException
4957 * ANY-ACCESS-MODIFIER Object readResolve() throws ObjectStreamException
4958 *
4959 * Fields:
4960 *
4961 * private static final long serialVersionUID
4962 * private static final ObjectStreamField[] serialPersistentFields
4963 *
4964 * Externalizable: methods defined on the interface
4965 * public void writeExternal(ObjectOutput) throws IOException
4966 * public void readExternal(ObjectInput) throws IOException
4967 */
4968 private class SerialTypeVisitor extends ElementKindVisitor14<Void, JCClassDecl> {
4969 Env<AttrContext> env;
4970 SerialTypeVisitor(Env<AttrContext> env) {
4971 this.lint = Check.this.lint;
4972 this.env = env;
4973 }
4974
4975 private static final Set<String> serialMethodNames =
4976 Set.of("writeObject", "writeReplace",
4977 "readObject", "readObjectNoData",
4978 "readResolve");
4979
4980 private static final Set<String> serialFieldNames =
4981 Set.of("serialVersionUID", "serialPersistentFields");
4982
4983 // Type of serialPersistentFields
4984 private final Type OSF_TYPE = new Type.ArrayType(syms.objectStreamFieldType, syms.arrayClass);
4985
4986 Lint lint;
4987
4988 @Override
4989 public Void defaultAction(Element e, JCClassDecl p) {
4990 throw new IllegalArgumentException(Objects.requireNonNullElse(e.toString(), ""));
4991 }
4992
4993 @Override
4994 public Void visitType(TypeElement e, JCClassDecl p) {
4995 runUnderLint(e, p, (symbol, param) -> super.visitType(symbol, param));
4996 return null;
4997 }
4998
4999 @Override
5000 public Void visitTypeAsClass(TypeElement e,
5001 JCClassDecl p) {
5002 // Anonymous classes filtered out by caller.
5003
5004 ClassSymbol c = (ClassSymbol)e;
5005
5006 checkCtorAccess(p, c);
5007
5008 /* Check for missing serialVersionUID; check *not* done
5009 * for enums or records.
5010 * Migrated value classes, need the value class and its corresponding
5011 * identity class to have the same SVUID.
5012 */
5013 VarSymbol svuidSym = null;
5014 for (Symbol sym : c.members().getSymbolsByName(names.serialVersionUID)) {
5015 if (sym.kind == VAR) {
5016 svuidSym = (VarSymbol)sym;
5017 break;
5018 }
5019 }
5020
5021 if (svuidSym == null) {
5022 log.warning(p.pos(), LintWarnings.MissingSVUID(c));
5023 }
5024
5025 // Check for serialPersistentFields to gate checks for
5026 // non-serializable non-transient instance fields
5027 boolean serialPersistentFieldsPresent =
5028 c.members()
5029 .getSymbolsByName(names.serialPersistentFields, sym -> sym.kind == VAR)
5030 .iterator()
5031 .hasNext();
5032
5033 // Check declarations of serialization-related methods and
5034 // fields
5035 final Map<String, Symbol> declaredSerialMethodNames = new HashMap<>();
5036 for(Symbol el : c.getEnclosedElements()) {
5037 runUnderLint(el, p, (enclosed, tree) -> {
5038 String name = null;
5039 switch(enclosed.getKind()) {
5040 case FIELD -> {
5041 if (!serialPersistentFieldsPresent) {
5042 var flags = enclosed.flags();
5043 if ( ((flags & TRANSIENT) == 0) &&
5044 ((flags & STATIC) == 0)) {
5045 Type varType = enclosed.asType();
5046 if (!canBeSerialized(varType)) {
5047 // Note per JLS arrays are
5048 // serializable even if the
5049 // component type is not.
5050 log.warning(
5051 TreeInfo.diagnosticPositionFor(enclosed, tree),
5052 LintWarnings.NonSerializableInstanceField);
5053 } else if (varType.hasTag(ARRAY)) {
5054 ArrayType arrayType = (ArrayType)varType;
5055 Type elementType = arrayType.elemtype;
5056 while (elementType.hasTag(ARRAY)) {
5057 arrayType = (ArrayType)elementType;
5058 elementType = arrayType.elemtype;
5059 }
5060 if (!canBeSerialized(elementType)) {
5061 log.warning(
5062 TreeInfo.diagnosticPositionFor(enclosed, tree),
5063 LintWarnings.NonSerializableInstanceFieldArray(elementType));
5064 }
5065 }
5066 }
5067 }
5068
5069 name = enclosed.getSimpleName().toString();
5070 if (serialFieldNames.contains(name)) {
5071 VarSymbol field = (VarSymbol)enclosed;
5072 switch (name) {
5073 case "serialVersionUID" -> checkSerialVersionUID(tree, e, field);
5074 case "serialPersistentFields" -> checkSerialPersistentFields(tree, e, field);
5075 default -> throw new AssertionError();
5076 }
5077 }
5078 }
5079
5080 // Correctly checking the serialization-related
5081 // methods is subtle. For the methods declared to be
5082 // private or directly declared in the class, the
5083 // enclosed elements of the class can be checked in
5084 // turn. However, writeReplace and readResolve can be
5085 // declared in a superclass and inherited. Note that
5086 // the runtime lookup walks the superclass chain
5087 // looking for writeReplace/readResolve via
5088 // Class.getDeclaredMethod. This differs from calling
5089 // Elements.getAllMembers(TypeElement) as the latter
5090 // will also pull in default methods from
5091 // superinterfaces. In other words, the runtime checks
5092 // (which long predate default methods on interfaces)
5093 // do not admit the possibility of inheriting methods
5094 // this way, a difference from general inheritance.
5095
5096 // The current implementation just checks the enclosed
5097 // elements and does not directly check the inherited
5098 // methods. If all the types are being checked this is
5099 // less of a concern; however, there are cases that
5100 // could be missed. In particular, readResolve and
5101 // writeReplace could, in principle, by inherited from
5102 // a non-serializable superclass and thus not checked
5103 // even if compiled with a serializable child class.
5104 case METHOD -> {
5105 var method = (MethodSymbol)enclosed;
5106 name = method.getSimpleName().toString();
5107 if (serialMethodNames.contains(name)) {
5108 if (switch (name) {
5109 case "writeObject" -> hasAppropriateWriteObject(tree, e, method);
5110 case "writeReplace" -> hasAppropriateWriteReplace(tree, method, true);
5111 case "readObject" -> hasAppropriateReadObject(tree, e, method);
5112 case "readObjectNoData" -> hasAppropriateReadObjectNoData(tree, e, method);
5113 case "readResolve" -> hasAppropriateReadResolve(tree, e, method);
5114 default -> throw new AssertionError();
5115 }) {
5116 declaredSerialMethodNames.put(name, el);
5117 }
5118 }
5119 }
5120 }
5121 });
5122 }
5123 if (declaredSerialMethodNames.get("writeReplace") == null &&
5124 (c.isValueClass() || hasAbstractValueSuperClass(c, Set.of(syms.numberType.tsym))) &&
5125 !c.isAbstract() && !c.isRecord() &&
5126 types.unboxedType(c.type) == Type.noType) {
5127 /* if we are dealing with a value class or with a class with a super class that happens to
5128 * be an abstract value class, that is not declaring a proper `writeReplace` method, then we
5129 * need to make sure then that it is inheriting an appropriate one.
5130 */
5131 MethodSymbol ms = null;
5132 Log.DiagnosticHandler discardHandler = log.new DiscardDiagnosticHandler();
5133 try {
5134 ms = rs.resolveInternalMethod(env.tree, env, c.type, names.writeReplace, List.nil(), List.nil());
5135 } catch (FatalError fe) {
5136 // ignore no method was found
5137 } finally {
5138 log.popDiagnosticHandler(discardHandler);
5139 }
5140 if (ms == null || !hasAppropriateWriteReplace(p, ms, false)) {
5141 log.warning(p.pos(),
5142 c.isValueClass() ? LintWarnings.SerializableValueClassWithoutWriteReplace1 :
5143 LintWarnings.SerializableValueClassWithoutWriteReplace2);
5144 }
5145 }
5146 if (c.isValueClass()) {
5147 /* Value classes are Serializable through the use of the serialization proxy pattern.
5148 * The serialization protocol does not support a standard serialized form for value classes.
5149 * The value class delegates to a serialization proxy by supplying an alternate
5150 * record or object to be serialized instead of the value class.
5151 * When the proxy is deserialized it re-constructs the value object and returns the value object.
5152 *
5153 * In particular methods:
5154 * - writeObject
5155 * - readObject and
5156 * - readObjectNoData
5157 * are not invoked for value classes, we need to warn the user about this
5158 */
5159 for (Map.Entry<String, Symbol> entry : declaredSerialMethodNames.entrySet()) {
5160 String key = entry.getKey();
5161 if (key.equals("writeObject") || key.equals("readObject") || key.equals("readObjectNoData")) {
5162 log.warning(TreeInfo.diagnosticPositionFor(entry.getValue(), p), LintWarnings.IneffectualSerialMethodValueClass(key));
5163 }
5164 }
5165 }
5166 return null;
5167 }
5168
5169 boolean canBeSerialized(Type type) {
5170 return type.isPrimitive() || rs.isSerializable(type);
5171 }
5172
5173 private boolean hasAbstractValueSuperClass(Symbol c, Set<Symbol> excluding) {
5174 while (c.getKind() == ElementKind.CLASS) {
5175 Type sup = ((ClassSymbol)c).getSuperclass();
5176 if (!sup.hasTag(CLASS) || sup.isErroneous() ||
5177 sup.tsym == syms.objectType.tsym) {
5178 return false;
5179 }
5180 // if it is a value super class it has to be abstract
5181 if (sup.isValueClass() && !excluding.contains(sup.tsym)) {
5182 return true;
5183 }
5184 c = sup.tsym;
5185 }
5186 return false;
5187 }
5188
5189 /**
5190 * Check that Externalizable class needs a public no-arg
5191 * constructor.
5192 *
5193 * Check that a Serializable class has access to the no-arg
5194 * constructor of its first nonserializable superclass.
5195 */
5196 private void checkCtorAccess(JCClassDecl tree, ClassSymbol c) {
5197 if (isExternalizable(c.type)) {
5198 for(var sym : c.getEnclosedElements()) {
5199 if (sym.isConstructor() &&
5200 ((sym.flags() & PUBLIC) == PUBLIC)) {
5201 if (((MethodSymbol)sym).getParameters().isEmpty()) {
5202 return;
5203 }
5204 }
5205 }
5206 log.warning(tree.pos(),
5207 LintWarnings.ExternalizableMissingPublicNoArgCtor);
5208 } else {
5209 // Approximate access to the no-arg constructor up in
5210 // the superclass chain by checking that the
5211 // constructor is not private. This may not handle
5212 // some cross-package situations correctly.
5213 Type superClass = c.getSuperclass();
5214 // java.lang.Object is *not* Serializable so this loop
5215 // should terminate.
5216 while (rs.isSerializable(superClass) ) {
5217 try {
5218 superClass = (Type)((TypeElement)(((DeclaredType)superClass)).asElement()).getSuperclass();
5219 } catch(ClassCastException cce) {
5220 return ; // Don't try to recover
5221 }
5222 }
5223 // Non-Serializable superclass
5224 try {
5225 ClassSymbol supertype = ((ClassSymbol)(((DeclaredType)superClass).asElement()));
5226 for(var sym : supertype.getEnclosedElements()) {
5227 if (sym.isConstructor()) {
5228 MethodSymbol ctor = (MethodSymbol)sym;
5229 if (ctor.getParameters().isEmpty()) {
5230 if (((ctor.flags() & PRIVATE) == PRIVATE) ||
5231 // Handle nested classes and implicit this$0
5232 (supertype.getNestingKind() == NestingKind.MEMBER &&
5233 ((supertype.flags() & STATIC) == 0)))
5234 log.warning(tree.pos(),
5235 LintWarnings.SerializableMissingAccessNoArgCtor(supertype.getQualifiedName()));
5236 }
5237 }
5238 }
5239 } catch (ClassCastException cce) {
5240 return ; // Don't try to recover
5241 }
5242 return;
5243 }
5244 }
5245
5246 private void checkSerialVersionUID(JCClassDecl tree, Element e, VarSymbol svuid) {
5247 // To be effective, serialVersionUID must be marked static
5248 // and final, but private is recommended. But alas, in
5249 // practice there are many non-private serialVersionUID
5250 // fields.
5251 if ((svuid.flags() & (STATIC | FINAL)) !=
5252 (STATIC | FINAL)) {
5253 log.warning(
5254 TreeInfo.diagnosticPositionFor(svuid, tree),
5255 LintWarnings.ImproperSVUID((Symbol)e));
5256 }
5257
5258 // check svuid has type long
5259 if (!svuid.type.hasTag(LONG)) {
5260 log.warning(
5261 TreeInfo.diagnosticPositionFor(svuid, tree),
5262 LintWarnings.LongSVUID((Symbol)e));
5263 }
5264
5265 if (svuid.getConstValue() == null)
5266 log.warning(
5267 TreeInfo.diagnosticPositionFor(svuid, tree),
5268 LintWarnings.ConstantSVUID((Symbol)e));
5269 }
5270
5271 private void checkSerialPersistentFields(JCClassDecl tree, Element e, VarSymbol spf) {
5272 // To be effective, serialPersisentFields must be private, static, and final.
5273 if ((spf.flags() & (PRIVATE | STATIC | FINAL)) !=
5274 (PRIVATE | STATIC | FINAL)) {
5275 log.warning(
5276 TreeInfo.diagnosticPositionFor(spf, tree),
5277 LintWarnings.ImproperSPF);
5278 }
5279
5280 if (!types.isSameType(spf.type, OSF_TYPE)) {
5281 log.warning(
5282 TreeInfo.diagnosticPositionFor(spf, tree),
5283 LintWarnings.OSFArraySPF);
5284 }
5285
5286 if (isExternalizable((Type)(e.asType()))) {
5287 log.warning(
5288 TreeInfo.diagnosticPositionFor(spf, tree),
5289 LintWarnings.IneffectualSerialFieldExternalizable);
5290 }
5291
5292 // Warn if serialPersistentFields is initialized to a
5293 // literal null.
5294 JCTree spfDecl = TreeInfo.declarationFor(spf, tree);
5295 if (spfDecl != null && spfDecl.getTag() == VARDEF) {
5296 JCVariableDecl variableDef = (JCVariableDecl) spfDecl;
5297 JCExpression initExpr = variableDef.init;
5298 if (initExpr != null && TreeInfo.isNull(initExpr)) {
5299 log.warning(initExpr.pos(),
5300 LintWarnings.SPFNullInit);
5301 }
5302 }
5303 }
5304
5305 private boolean hasAppropriateWriteObject(JCClassDecl tree, Element e, MethodSymbol method) {
5306 // The "synchronized" modifier is seen in the wild on
5307 // readObject and writeObject methods and is generally
5308 // innocuous.
5309
5310 // private void writeObject(ObjectOutputStream stream) throws IOException
5311 return isPrivateNonStaticMethod(tree, method) & // no short-circuit we need to log warnings
5312 isExpectedReturnType(tree, method, syms.voidType, true) &
5313 hasExpectedArg(tree, method, syms.objectOutputStreamType) &
5314 hasExpectedExceptions(tree, method, true, syms.ioExceptionType) &
5315 checkExternalizable(tree, e, method);
5316 }
5317
5318 private boolean hasAppropriateWriteReplace(JCClassDecl tree, MethodSymbol method, boolean warn) {
5319 // ANY-ACCESS-MODIFIER Object writeReplace() throws
5320 // ObjectStreamException
5321
5322 // Excluding abstract, could have a more complicated
5323 // rule based on abstract-ness of the class
5324 return isConcreteInstanceMethod(tree, method, warn) & // no short-circuit we need to log warnings
5325 isExpectedReturnType(tree, method, syms.objectType, warn) &
5326 hasNoArgs(tree, method, warn) &
5327 hasExpectedExceptions(tree, method, warn, syms.objectStreamExceptionType);
5328 }
5329
5330 private boolean hasAppropriateReadObject(JCClassDecl tree, Element e, MethodSymbol method) {
5331 // The "synchronized" modifier is seen in the wild on
5332 // readObject and writeObject methods and is generally
5333 // innocuous.
5334
5335 // private void readObject(ObjectInputStream stream)
5336 // throws IOException, ClassNotFoundException
5337 return isPrivateNonStaticMethod(tree, method) & // no short-circuit we need to log warnings
5338 isExpectedReturnType(tree, method, syms.voidType, true) &
5339 hasExpectedArg(tree, method, syms.objectInputStreamType) &
5340 hasExpectedExceptions(tree, method, true, syms.ioExceptionType, syms.classNotFoundExceptionType) &
5341 checkExternalizable(tree, e, method);
5342 }
5343
5344 private boolean hasAppropriateReadObjectNoData(JCClassDecl tree, Element e, MethodSymbol method) {
5345 // private void readObjectNoData() throws ObjectStreamException
5346 return isPrivateNonStaticMethod(tree, method) & // no short-circuit we need to log warnings
5347 isExpectedReturnType(tree, method, syms.voidType, true) &
5348 hasNoArgs(tree, method, true) &
5349 hasExpectedExceptions(tree, method, true, syms.objectStreamExceptionType) &
5350 checkExternalizable(tree, e, method);
5351 }
5352
5353 private boolean hasAppropriateReadResolve(JCClassDecl tree, Element e, MethodSymbol method) {
5354 // ANY-ACCESS-MODIFIER Object readResolve()
5355 // throws ObjectStreamException
5356
5357 // Excluding abstract, could have a more complicated
5358 // rule based on abstract-ness of the class
5359 return isConcreteInstanceMethod(tree, method, true) & // no short-circuit we need to log warnings
5360 isExpectedReturnType(tree, method, syms.objectType, true) &
5361 hasNoArgs(tree, method, true) &
5362 hasExpectedExceptions(tree, method, true, syms.objectStreamExceptionType);
5363 }
5364
5365 private void checkWriteExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) {
5366 //public void writeExternal(ObjectOutput) throws IOException
5367 checkExternMethodRecord(tree, e, method, syms.objectOutputType, isExtern);
5368 }
5369
5370 private void checkReadExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) {
5371 // public void readExternal(ObjectInput) throws IOException
5372 checkExternMethodRecord(tree, e, method, syms.objectInputType, isExtern);
5373 }
5374
5375 private void checkExternMethodRecord(JCClassDecl tree, Element e, MethodSymbol method, Type argType,
5376 boolean isExtern) {
5377 if (isExtern && isExternMethod(tree, e, method, argType)) {
5378 log.warning(
5379 TreeInfo.diagnosticPositionFor(method, tree),
5380 LintWarnings.IneffectualExternalizableMethodRecord(method.getSimpleName().toString()));
5381 }
5382 }
5383
5384 boolean isPrivateNonStaticMethod(JCClassDecl tree, MethodSymbol method) {
5385 var flags = method.flags();
5386 boolean result = true;
5387 if ((flags & PRIVATE) == 0) {
5388 log.warning(
5389 TreeInfo.diagnosticPositionFor(method, tree),
5390 LintWarnings.SerialMethodNotPrivate(method.getSimpleName()));
5391 result = false;
5392 }
5393
5394 if ((flags & STATIC) != 0) {
5395 log.warning(
5396 TreeInfo.diagnosticPositionFor(method, tree),
5397 LintWarnings.SerialMethodStatic(method.getSimpleName()));
5398 result = false;
5399 }
5400 return result;
5401 }
5402
5403 /**
5404 * Per section 1.12 "Serialization of Enum Constants" of
5405 * the serialization specification, due to the special
5406 * serialization handling of enums, any writeObject,
5407 * readObject, writeReplace, and readResolve methods are
5408 * ignored as are serialPersistentFields and
5409 * serialVersionUID fields.
5410 */
5411 @Override
5412 public Void visitTypeAsEnum(TypeElement e,
5413 JCClassDecl p) {
5414 boolean isExtern = isExternalizable((Type)e.asType());
5415 for(Element el : e.getEnclosedElements()) {
5416 runUnderLint(el, p, (enclosed, tree) -> {
5417 String name = enclosed.getSimpleName().toString();
5418 switch(enclosed.getKind()) {
5419 case FIELD -> {
5420 var field = (VarSymbol)enclosed;
5421 if (serialFieldNames.contains(name)) {
5422 log.warning(
5423 TreeInfo.diagnosticPositionFor(field, tree),
5424 LintWarnings.IneffectualSerialFieldEnum(name));
5425 }
5426 }
5427
5428 case METHOD -> {
5429 var method = (MethodSymbol)enclosed;
5430 if (serialMethodNames.contains(name)) {
5431 log.warning(
5432 TreeInfo.diagnosticPositionFor(method, tree),
5433 LintWarnings.IneffectualSerialMethodEnum(name));
5434 }
5435
5436 if (isExtern) {
5437 switch(name) {
5438 case "writeExternal" -> checkWriteExternalEnum(tree, e, method);
5439 case "readExternal" -> checkReadExternalEnum(tree, e, method);
5440 }
5441 }
5442 }
5443
5444 // Also perform checks on any class bodies of enum constants, see JLS 8.9.1.
5445 case ENUM_CONSTANT -> {
5446 var field = (VarSymbol)enclosed;
5447 JCVariableDecl decl = (JCVariableDecl) TreeInfo.declarationFor(field, p);
5448 if (decl.init instanceof JCNewClass nc && nc.def != null) {
5449 ClassSymbol enumConstantType = nc.def.sym;
5450 visitTypeAsEnum(enumConstantType, p);
5451 }
5452 }
5453
5454 }});
5455 }
5456 return null;
5457 }
5458
5459 private void checkWriteExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) {
5460 //public void writeExternal(ObjectOutput) throws IOException
5461 checkExternMethodEnum(tree, e, method, syms.objectOutputType);
5462 }
5463
5464 private void checkReadExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) {
5465 // public void readExternal(ObjectInput) throws IOException
5466 checkExternMethodEnum(tree, e, method, syms.objectInputType);
5467 }
5468
5469 private void checkExternMethodEnum(JCClassDecl tree, Element e, MethodSymbol method, Type argType) {
5470 if (isExternMethod(tree, e, method, argType)) {
5471 log.warning(
5472 TreeInfo.diagnosticPositionFor(method, tree),
5473 LintWarnings.IneffectualExternMethodEnum(method.getSimpleName().toString()));
5474 }
5475 }
5476
5477 private boolean isExternMethod(JCClassDecl tree, Element e, MethodSymbol method, Type argType) {
5478 long flags = method.flags();
5479 Type rtype = method.getReturnType();
5480
5481 // Not necessary to check throws clause in this context
5482 return (flags & PUBLIC) != 0 && (flags & STATIC) == 0 &&
5483 types.isSameType(syms.voidType, rtype) &&
5484 hasExactlyOneArgWithType(tree, e, method, argType);
5485 }
5486
5487 /**
5488 * Most serialization-related fields and methods on interfaces
5489 * are ineffectual or problematic.
5490 */
5491 @Override
5492 public Void visitTypeAsInterface(TypeElement e,
5493 JCClassDecl p) {
5494 for(Element el : e.getEnclosedElements()) {
5495 runUnderLint(el, p, (enclosed, tree) -> {
5496 String name = null;
5497 switch(enclosed.getKind()) {
5498 case FIELD -> {
5499 var field = (VarSymbol)enclosed;
5500 name = field.getSimpleName().toString();
5501 switch(name) {
5502 case "serialPersistentFields" -> {
5503 log.warning(
5504 TreeInfo.diagnosticPositionFor(field, tree),
5505 LintWarnings.IneffectualSerialFieldInterface);
5506 }
5507
5508 case "serialVersionUID" -> {
5509 checkSerialVersionUID(tree, e, field);
5510 }
5511 }
5512 }
5513
5514 case METHOD -> {
5515 var method = (MethodSymbol)enclosed;
5516 name = enclosed.getSimpleName().toString();
5517 if (serialMethodNames.contains(name)) {
5518 switch (name) {
5519 case
5520 "readObject",
5521 "readObjectNoData",
5522 "writeObject" -> checkPrivateMethod(tree, e, method);
5523
5524 case
5525 "writeReplace",
5526 "readResolve" -> checkDefaultIneffective(tree, e, method);
5527
5528 default -> throw new AssertionError();
5529 }
5530
5531 }
5532 }}
5533 });
5534 }
5535
5536 return null;
5537 }
5538
5539 private void checkPrivateMethod(JCClassDecl tree,
5540 Element e,
5541 MethodSymbol method) {
5542 if ((method.flags() & PRIVATE) == 0) {
5543 log.warning(
5544 TreeInfo.diagnosticPositionFor(method, tree),
5545 LintWarnings.NonPrivateMethodWeakerAccess);
5546 }
5547 }
5548
5549 private void checkDefaultIneffective(JCClassDecl tree,
5550 Element e,
5551 MethodSymbol method) {
5552 if ((method.flags() & DEFAULT) == DEFAULT) {
5553 log.warning(
5554 TreeInfo.diagnosticPositionFor(method, tree),
5555 LintWarnings.DefaultIneffective);
5556
5557 }
5558 }
5559
5560 @Override
5561 public Void visitTypeAsAnnotationType(TypeElement e,
5562 JCClassDecl p) {
5563 // Per the JLS, annotation types are not serializeable
5564 return null;
5565 }
5566
5567 /**
5568 * From the Java Object Serialization Specification, 1.13
5569 * Serialization of Records:
5570 *
5571 * "The process by which record objects are serialized or
5572 * externalized cannot be customized; any class-specific
5573 * writeObject, readObject, readObjectNoData, writeExternal,
5574 * and readExternal methods defined by record classes are
5575 * ignored during serialization and deserialization. However,
5576 * a substitute object to be serialized or a designate
5577 * replacement may be specified, by the writeReplace and
5578 * readResolve methods, respectively. Any
5579 * serialPersistentFields field declaration is
5580 * ignored. Documenting serializable fields and data for
5581 * record classes is unnecessary, since there is no variation
5582 * in the serial form, other than whether a substitute or
5583 * replacement object is used. The serialVersionUID of a
5584 * record class is 0L unless explicitly declared. The
5585 * requirement for matching serialVersionUID values is waived
5586 * for record classes."
5587 */
5588 @Override
5589 public Void visitTypeAsRecord(TypeElement e,
5590 JCClassDecl p) {
5591 boolean isExtern = isExternalizable((Type)e.asType());
5592 for(Element el : e.getEnclosedElements()) {
5593 runUnderLint(el, p, (enclosed, tree) -> {
5594 String name = enclosed.getSimpleName().toString();
5595 switch(enclosed.getKind()) {
5596 case FIELD -> {
5597 var field = (VarSymbol)enclosed;
5598 switch(name) {
5599 case "serialPersistentFields" -> {
5600 log.warning(
5601 TreeInfo.diagnosticPositionFor(field, tree),
5602 LintWarnings.IneffectualSerialFieldRecord);
5603 }
5604
5605 case "serialVersionUID" -> {
5606 // Could generate additional warning that
5607 // svuid value is not checked to match for
5608 // records.
5609 checkSerialVersionUID(tree, e, field);
5610 }}
5611 }
5612
5613 case METHOD -> {
5614 var method = (MethodSymbol)enclosed;
5615 switch(name) {
5616 case "writeReplace" -> hasAppropriateWriteReplace(tree, method, true);
5617 case "readResolve" -> hasAppropriateReadResolve(tree, e, method);
5618
5619 case "writeExternal" -> checkWriteExternalRecord(tree, e, method, isExtern);
5620 case "readExternal" -> checkReadExternalRecord(tree, e, method, isExtern);
5621
5622 default -> {
5623 if (serialMethodNames.contains(name)) {
5624 log.warning(
5625 TreeInfo.diagnosticPositionFor(method, tree),
5626 LintWarnings.IneffectualSerialMethodRecord(name));
5627 }
5628 }}
5629 }}});
5630 }
5631 return null;
5632 }
5633
5634 boolean isConcreteInstanceMethod(JCClassDecl tree,
5635 MethodSymbol method,
5636 boolean warn) {
5637 if ((method.flags() & (STATIC | ABSTRACT)) != 0) {
5638 if (warn) {
5639 log.warning(
5640 TreeInfo.diagnosticPositionFor(method, tree),
5641 LintWarnings.SerialConcreteInstanceMethod(method.getSimpleName()));
5642 }
5643 return false;
5644 }
5645 return true;
5646 }
5647
5648 private boolean isExpectedReturnType(JCClassDecl tree,
5649 MethodSymbol method,
5650 Type expectedReturnType,
5651 boolean warn) {
5652 // Note: there may be complications checking writeReplace
5653 // and readResolve since they return Object and could, in
5654 // principle, have covariant overrides and any synthetic
5655 // bridge method would not be represented here for
5656 // checking.
5657 Type rtype = method.getReturnType();
5658 if (!types.isSameType(expectedReturnType, rtype)) {
5659 if (warn) {
5660 log.warning(
5661 TreeInfo.diagnosticPositionFor(method, tree),
5662 LintWarnings.SerialMethodUnexpectedReturnType(method.getSimpleName(),
5663 rtype, expectedReturnType));
5664 }
5665 return false;
5666 }
5667 return true;
5668 }
5669
5670 private boolean hasExpectedArg(JCClassDecl tree,
5671 MethodSymbol method,
5672 Type expectedType) {
5673
5674 var parameters= method.getParameters();
5675
5676 if (parameters.size() != 1) {
5677 log.warning(
5678 TreeInfo.diagnosticPositionFor(method, tree),
5679 LintWarnings.SerialMethodOneArg(method.getSimpleName(), parameters.size()));
5680 return false;
5681 }
5682
5683 Type parameterType = parameters.get(0).asType();
5684 if (!types.isSameType(parameterType, expectedType)) {
5685 log.warning(
5686 TreeInfo.diagnosticPositionFor(method, tree),
5687 LintWarnings.SerialMethodParameterType(method.getSimpleName(),
5688 expectedType,
5689 parameterType));
5690 return false;
5691 }
5692 return true;
5693 }
5694
5695 private boolean hasExactlyOneArgWithType(JCClassDecl tree,
5696 Element enclosing,
5697 MethodSymbol method,
5698 Type expectedType) {
5699 var parameters = method.getParameters();
5700 return (parameters.size() == 1) &&
5701 types.isSameType(parameters.get(0).asType(), expectedType);
5702 }
5703
5704
5705 boolean hasNoArgs(JCClassDecl tree, MethodSymbol method, boolean warn) {
5706 var parameters = method.getParameters();
5707 if (!parameters.isEmpty()) {
5708 if (warn) {
5709 log.warning(
5710 TreeInfo.diagnosticPositionFor(parameters.get(0), tree),
5711 LintWarnings.SerialMethodNoArgs(method.getSimpleName()));
5712 }
5713 return false;
5714 }
5715 return true;
5716 }
5717
5718 private boolean checkExternalizable(JCClassDecl tree, Element enclosing, MethodSymbol method) {
5719 // If the enclosing class is externalizable, warn for the method
5720 if (isExternalizable((Type)enclosing.asType())) {
5721 log.warning(
5722 TreeInfo.diagnosticPositionFor(method, tree),
5723 LintWarnings.IneffectualSerialMethodExternalizable(method.getSimpleName()));
5724 return false;
5725 }
5726 return true;
5727 }
5728
5729 private boolean hasExpectedExceptions(JCClassDecl tree,
5730 MethodSymbol method,
5731 boolean warn,
5732 Type... declaredExceptions) {
5733 for (Type thrownType: method.getThrownTypes()) {
5734 // For each exception in the throws clause of the
5735 // method, if not an Error and not a RuntimeException,
5736 // check if the exception is a subtype of a declared
5737 // exception from the throws clause of the
5738 // serialization method in question.
5739 if (types.isSubtype(thrownType, syms.runtimeExceptionType) ||
5740 types.isSubtype(thrownType, syms.errorType) ) {
5741 continue;
5742 } else {
5743 boolean declared = false;
5744 for (Type declaredException : declaredExceptions) {
5745 if (types.isSubtype(thrownType, declaredException)) {
5746 declared = true;
5747 continue;
5748 }
5749 }
5750 if (!declared) {
5751 if (warn) {
5752 log.warning(
5753 TreeInfo.diagnosticPositionFor(method, tree),
5754 LintWarnings.SerialMethodUnexpectedException(method.getSimpleName(),
5755 thrownType));
5756 }
5757 return false;
5758 }
5759 }
5760 }
5761 return true;
5762 }
5763
5764 private <E extends Element> Void runUnderLint(E symbol, JCClassDecl p, BiConsumer<E, JCClassDecl> task) {
5765 Lint prevLint = lint;
5766 try {
5767 lint = lint.augment((Symbol) symbol);
5768
5769 if (lint.isEnabled(LintCategory.SERIAL)) {
5770 task.accept(symbol, p);
5771 }
5772
5773 return null;
5774 } finally {
5775 lint = prevLint;
5776 }
5777 }
5778
5779 }
5780
5781 void checkRequiresIdentity(JCTree tree, Lint lint) {
5782 switch (tree) {
5783 case JCClassDecl classDecl -> {
5784 Type st = types.supertype(classDecl.sym.type);
5785 if (st != null &&
5786 // no need to recheck j.l.Object, shortcut,
5787 st.tsym != syms.objectType.tsym &&
5788 // this one could be null, no explicit extends
5789 classDecl.extending != null) {
5790 checkIfIdentityIsExpected(classDecl.extending.pos(), st, lint);
5791 }
5792 for (JCExpression intrface: classDecl.implementing) {
5793 checkIfIdentityIsExpected(intrface.pos(), intrface.type, lint);
5794 }
5795 for (JCTypeParameter tp : classDecl.typarams) {
5796 checkIfIdentityIsExpected(tp.pos(), tp.type, lint);
5797 }
5798 }
5799 case JCVariableDecl variableDecl -> {
5800 if (variableDecl.vartype != null &&
5801 ((variableDecl.sym.flags_field & RECORD) == 0 ||
5802 (variableDecl.sym.flags_field & ~(Flags.PARAMETER | RECORD | GENERATED_MEMBER)) != 0)) {
5803 /* we don't want to warn twice so if this variable is a compiler generated parameter of
5804 * a canonical record constructor, we don't want to issue a warning as we will warn the
5805 * corresponding compiler generated private record field anyways
5806 */
5807 checkIfIdentityIsExpected(variableDecl.vartype.pos(), variableDecl.vartype.type, lint);
5808 }
5809 }
5810 case JCTypeCast typeCast -> checkIfIdentityIsExpected(typeCast.clazz.pos(), typeCast.clazz.type, lint);
5811 case JCBindingPattern bindingPattern -> {
5812 if (bindingPattern.var.vartype != null) {
5813 checkIfIdentityIsExpected(bindingPattern.var.vartype.pos(), bindingPattern.var.vartype.type, lint);
5814 }
5815 }
5816 case JCMethodDecl methodDecl -> {
5817 for (JCTypeParameter tp : methodDecl.typarams) {
5818 checkIfIdentityIsExpected(tp.pos(), tp.type, lint);
5819 }
5820 if (methodDecl.restype != null && !methodDecl.restype.type.hasTag(VOID)) {
5821 checkIfIdentityIsExpected(methodDecl.restype.pos(), methodDecl.restype.type, lint);
5822 }
5823 }
5824 case JCMemberReference mref -> {
5825 checkIfIdentityIsExpected(mref.expr.pos(), mref.target, lint);
5826 checkIfTypeParamsRequiresIdentity(mref.sym.getMetadata(), mref.typeargs, lint);
5827 }
5828 case JCPolyExpression poly
5829 when (poly instanceof JCNewClass || poly instanceof JCMethodInvocation) -> {
5830 if (poly instanceof JCNewClass newClass) {
5831 checkIfIdentityIsExpected(newClass.clazz.pos(), newClass.clazz.type, lint);
5832 }
5833 List<JCExpression> argExps = poly instanceof JCNewClass ?
5834 ((JCNewClass)poly).args :
5835 ((JCMethodInvocation)poly).args;
5836 Symbol msym = TreeInfo.symbolFor(poly);
5837 if (msym != null) {
5838 if (!argExps.isEmpty() && msym instanceof MethodSymbol ms && ms.params != null) {
5839 VarSymbol lastParam = ms.params.head;
5840 for (VarSymbol param: ms.params) {
5841 if ((param.flags_field & REQUIRES_IDENTITY) != 0 && argExps.head.type.isValueBased()) {
5842 log.warning(argExps.head.pos(), LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5843 }
5844 lastParam = param;
5845 argExps = argExps.tail;
5846 }
5847 while (argExps != null && !argExps.isEmpty() && lastParam != null) {
5848 if ((lastParam.flags_field & REQUIRES_IDENTITY) != 0 && argExps.head.type.isValueBased()) {
5849 log.warning(argExps.head.pos(), LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5850 }
5851 argExps = argExps.tail;
5852 }
5853 }
5854 checkIfTypeParamsRequiresIdentity(
5855 msym.getMetadata(),
5856 poly instanceof JCNewClass ?
5857 ((JCNewClass)poly).typeargs :
5858 ((JCMethodInvocation)poly).typeargs,
5859 lint);
5860 }
5861 }
5862 default -> throw new AssertionError("unexpected tree " + tree);
5863 }
5864 }
5865
5866 /** Check if a type required an identity class
5867 */
5868 private boolean checkIfIdentityIsExpected(DiagnosticPosition pos, Type t, Lint lint) {
5869 if (t != null &&
5870 lint != null &&
5871 lint.isEnabled(LintCategory.IDENTITY)) {
5872 RequiresIdentityVisitor requiresIdentityVisitor = new RequiresIdentityVisitor();
5873 // we need to avoid recursion due to self referencing type vars or captures, this is why we need a set
5874 requiresIdentityVisitor.visit(t, new HashSet<>());
5875 if (requiresIdentityVisitor.requiresWarning) {
5876 log.warning(pos, LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5877 return true;
5878 }
5879 }
5880 return false;
5881 }
5882
5883 // where
5884 private class RequiresIdentityVisitor extends Types.SimpleVisitor<Void, Set<Type>> {
5885 boolean requiresWarning = false;
5886
5887 @Override
5888 public Void visitType(Type t, Set<Type> seen) {
5889 return null;
5890 }
5891
5892 @Override
5893 public Void visitWildcardType(WildcardType t, Set<Type> seen) {
5894 return visit(t.type, seen);
5895 }
5896
5897 @Override
5898 public Void visitTypeVar(TypeVar t, Set<Type> seen) {
5899 if (seen.add(t)) {
5900 visit(t.getUpperBound(), seen);
5901 }
5902 return null;
5903 }
5904
5905 @Override
5906 public Void visitCapturedType(CapturedType t, Set<Type> seen) {
5907 if (seen.add(t)) {
5908 visit(t.getUpperBound(), seen);
5909 visit(t.getLowerBound(), seen);
5910 }
5911 return null;
5912 }
5913
5914 @Override
5915 public Void visitArrayType(ArrayType t, Set<Type> seen) {
5916 return visit(t.elemtype, seen);
5917 }
5918
5919 @Override
5920 public Void visitClassType(ClassType t, Set<Type> seen) {
5921 if (t != null && t.tsym != null) {
5922 SymbolMetadata sm = t.tsym.getMetadata();
5923 if (sm != null && !t.getTypeArguments().isEmpty()) {
5924 if (sm.getTypeAttributes().stream()
5925 .filter(ta -> isRequiresIdentityAnnotation(ta.type.tsym) &&
5926 t.getTypeArguments().get(ta.position.parameter_index) != null &&
5927 t.getTypeArguments().get(ta.position.parameter_index).isValueBased()).findAny().isPresent()) {
5928 requiresWarning = true;
5929 return null;
5930 }
5931 }
5932 }
5933 visit(t.getEnclosingType(), seen);
5934 for (Type targ : t.getTypeArguments()) {
5935 visit(targ, seen);
5936 }
5937 return null;
5938 }
5939 } // RequiresIdentityVisitor
5940
5941 private void checkIfTypeParamsRequiresIdentity(SymbolMetadata sm,
5942 List<JCExpression> typeParamTrees,
5943 Lint lint) {
5944 if (typeParamTrees != null && !typeParamTrees.isEmpty()) {
5945 for (JCExpression targ : typeParamTrees) {
5946 checkIfIdentityIsExpected(targ.pos(), targ.type, lint);
5947 }
5948 if (sm != null)
5949 sm.getTypeAttributes().stream()
5950 .filter(ta -> isRequiresIdentityAnnotation(ta.type.tsym) &&
5951 typeParamTrees.get(ta.position.parameter_index).type != null &&
5952 typeParamTrees.get(ta.position.parameter_index).type.isValueBased())
5953 .forEach(ta -> log.warning(typeParamTrees.get(ta.position.parameter_index).pos(),
5954 CompilerProperties.LintWarnings.AttemptToUseValueBasedWhereIdentityExpected));
5955 }
5956 }
5957
5958 private boolean isRequiresIdentityAnnotation(TypeSymbol annoType) {
5959 return annoType == syms.requiresIdentityType.tsym ||
5960 annoType.flatName() == syms.requiresIdentityInternalType.tsym.flatName();
5961 }
5962 }