1 /*
2 * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.comp;
27
28 import java.util.*;
29 import java.util.function.BiConsumer;
30 import java.util.function.BiPredicate;
31 import java.util.function.Function;
32 import java.util.function.Predicate;
33 import java.util.function.Supplier;
34 import java.util.function.ToIntBiFunction;
35 import java.util.stream.Collectors;
36 import java.util.stream.StreamSupport;
37
38 import javax.lang.model.element.ElementKind;
39 import javax.lang.model.element.NestingKind;
40 import javax.tools.JavaFileManager;
41
42 import com.sun.source.tree.CaseTree;
43 import com.sun.tools.javac.code.*;
44 import com.sun.tools.javac.code.Attribute.Compound;
45 import com.sun.tools.javac.code.Directive.ExportsDirective;
46 import com.sun.tools.javac.code.Directive.RequiresDirective;
47 import com.sun.tools.javac.code.Source.Feature;
48 import com.sun.tools.javac.comp.Annotate.AnnotationTypeMetadata;
49 import com.sun.tools.javac.jvm.*;
50 import com.sun.tools.javac.resources.CompilerProperties;
51 import com.sun.tools.javac.resources.CompilerProperties.Errors;
52 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
53 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
54 import com.sun.tools.javac.resources.CompilerProperties.LintWarnings;
55 import com.sun.tools.javac.tree.*;
56 import com.sun.tools.javac.util.*;
57 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
58 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
59 import com.sun.tools.javac.util.JCDiagnostic.Error;
60 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
61 import com.sun.tools.javac.util.JCDiagnostic.LintWarning;
62 import com.sun.tools.javac.util.List;
63
64 import com.sun.tools.javac.code.Lint;
65 import com.sun.tools.javac.code.Lint.LintCategory;
66 import com.sun.tools.javac.code.Scope.WriteableScope;
67 import com.sun.tools.javac.code.Type.*;
68 import com.sun.tools.javac.code.Symbol.*;
69 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
70 import com.sun.tools.javac.tree.JCTree.*;
71
72 import static com.sun.tools.javac.code.Flags.*;
73 import static com.sun.tools.javac.code.Flags.ANNOTATION;
74 import static com.sun.tools.javac.code.Flags.SYNCHRONIZED;
75 import static com.sun.tools.javac.code.Kinds.*;
76 import static com.sun.tools.javac.code.Kinds.Kind.*;
77 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
78 import static com.sun.tools.javac.code.Scope.LookupKind.RECURSIVE;
79 import static com.sun.tools.javac.code.TypeTag.*;
80 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
81
82 import static com.sun.tools.javac.tree.JCTree.Tag.*;
83 import javax.lang.model.element.Element;
84 import javax.lang.model.element.TypeElement;
85 import javax.lang.model.type.DeclaredType;
86 import javax.lang.model.util.ElementKindVisitor14;
87
88 /** Type checking helper class for the attribution phase.
89 *
90 * <p><b>This is NOT part of any supported API.
91 * If you write code that depends on this, you do so at your own risk.
92 * This code and its internal interfaces are subject to change or
93 * deletion without notice.</b>
94 */
95 public class Check {
96 protected static final Context.Key<Check> checkKey = new Context.Key<>();
97
98 // Flag bits indicating which item(s) chosen from a pair of items
99 private static final int FIRST = 0x01;
100 private static final int SECOND = 0x02;
101
102 private final Names names;
103 private final Log log;
104 private final Resolve rs;
105 private final Symtab syms;
106 private final Enter enter;
107 private final DeferredAttr deferredAttr;
108 private final Infer infer;
109 private final Types types;
110 private final TypeAnnotations typeAnnotations;
111 private final JCDiagnostic.Factory diags;
112 private final JavaFileManager fileManager;
113 private final Source source;
114 private final Target target;
115 private final Profile profile;
116 private final Preview preview;
117 private final boolean warnOnAnyAccessToMembers;
118
119 public boolean disablePreviewCheck;
120
121 // The set of lint options currently in effect. It is initialized
122 // from the context, and then is set/reset as needed by Attr as it
123 // visits all the various parts of the trees during attribution.
124 private Lint lint;
125
126 // The method being analyzed in Attr - it is set/reset as needed by
127 // Attr as it visits new method declarations.
128 private MethodSymbol method;
129
130 public static Check instance(Context context) {
131 Check instance = context.get(checkKey);
132 if (instance == null)
133 instance = new Check(context);
134 return instance;
135 }
136
137 @SuppressWarnings("this-escape")
138 protected Check(Context context) {
139 context.put(checkKey, this);
140
141 names = Names.instance(context);
142 log = Log.instance(context);
143 rs = Resolve.instance(context);
144 syms = Symtab.instance(context);
145 enter = Enter.instance(context);
146 deferredAttr = DeferredAttr.instance(context);
147 infer = Infer.instance(context);
148 types = Types.instance(context);
149 typeAnnotations = TypeAnnotations.instance(context);
150 diags = JCDiagnostic.Factory.instance(context);
151 Options options = Options.instance(context);
152 lint = Lint.instance(context);
153 fileManager = context.get(JavaFileManager.class);
154
155 source = Source.instance(context);
156 target = Target.instance(context);
157 warnOnAnyAccessToMembers = options.isSet("warnOnAccessToMembers");
158
159 disablePreviewCheck = false;
160
161 Target target = Target.instance(context);
162 syntheticNameChar = target.syntheticNameChar();
163
164 profile = Profile.instance(context);
165 preview = Preview.instance(context);
166
167 allowModules = Feature.MODULES.allowedInSource(source);
168 allowRecords = Feature.RECORDS.allowedInSource(source);
169 allowSealed = Feature.SEALED_CLASSES.allowedInSource(source);
170 allowValueClasses = (!preview.isPreview(Feature.VALUE_CLASSES) || preview.isEnabled()) &&
171 Feature.VALUE_CLASSES.allowedInSource(source);
172 }
173
174 /** Character for synthetic names
175 */
176 char syntheticNameChar;
177
178 /** A table mapping flat names of all compiled classes for each module in this run
179 * to their symbols; maintained from outside.
180 */
181 private Map<Pair<ModuleSymbol, Name>,ClassSymbol> compiled = new HashMap<>();
182
183 /** Are modules allowed
184 */
185 private final boolean allowModules;
186
187 /** Are records allowed
188 */
189 private final boolean allowRecords;
190
191 /** Are sealed classes allowed
192 */
193 private final boolean allowSealed;
194
195 /** Are value classes allowed
196 */
197 private final boolean allowValueClasses;
198
199 /** Whether to force suppression of deprecation and preview warnings.
200 * This happens when attributing import statements for JDK 9+.
201 * @see Feature#DEPRECATION_ON_IMPORT
202 */
203 private boolean importSuppression;
204
205 /* *************************************************************************
206 * Errors and Warnings
207 **************************************************************************/
208
209 Lint setLint(Lint newLint) {
210 Lint prev = lint;
211 lint = newLint;
212 return prev;
213 }
214
215 boolean setImportSuppression(boolean newImportSuppression) {
216 boolean prev = importSuppression;
217 importSuppression = newImportSuppression;
218 return prev;
219 }
220
221 MethodSymbol setMethod(MethodSymbol newMethod) {
222 MethodSymbol prev = method;
223 method = newMethod;
224 return prev;
225 }
226
227 /** Warn about deprecated symbol.
228 * @param pos Position to be used for error reporting.
229 * @param sym The deprecated symbol.
230 */
231 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
232 Assert.check(!importSuppression);
233 LintWarning warningKey = sym.isDeprecatedForRemoval() ?
234 (sym.kind == MDL ?
235 LintWarnings.HasBeenDeprecatedForRemovalModule(sym) :
236 LintWarnings.HasBeenDeprecatedForRemoval(sym, sym.location())) :
237 (sym.kind == MDL ?
238 LintWarnings.HasBeenDeprecatedModule(sym) :
239 LintWarnings.HasBeenDeprecated(sym, sym.location()));
240 log.warning(pos, warningKey);
241 }
242
243 /** Log a preview warning.
244 * @param pos Position to be used for error reporting.
245 * @param msg A Warning describing the problem.
246 */
247 public void warnPreviewAPI(DiagnosticPosition pos, LintWarning warnKey) {
248 if (!importSuppression)
249 log.warning(pos, warnKey);
250 }
251
252 /** Warn about unchecked operation.
253 * @param pos Position to be used for error reporting.
254 * @param msg A string describing the problem.
255 */
256 public void warnUnchecked(DiagnosticPosition pos, LintWarning warnKey) {
257 log.warning(pos, warnKey);
258 }
259
260 /** Report a failure to complete a class.
261 * @param pos Position to be used for error reporting.
262 * @param ex The failure to report.
263 */
264 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
265 log.error(DiagnosticFlag.NON_DEFERRABLE, pos, Errors.CantAccess(ex.sym, ex.getDetailValue()));
266 return syms.errType;
267 }
268
269 /** Report an error that wrong type tag was found.
270 * @param pos Position to be used for error reporting.
271 * @param required An internationalized string describing the type tag
272 * required.
273 * @param found The type that was found.
274 */
275 Type typeTagError(DiagnosticPosition pos, JCDiagnostic required, Object found) {
276 // this error used to be raised by the parser,
277 // but has been delayed to this point:
278 if (found instanceof Type type && type.hasTag(VOID)) {
279 log.error(pos, Errors.IllegalStartOfType);
280 return syms.errType;
281 }
282 log.error(pos, Errors.TypeFoundReq(found, required));
283 return types.createErrorType(found instanceof Type type ? type : syms.errType);
284 }
285
286 /** Report duplicate declaration error.
287 */
288 void duplicateError(DiagnosticPosition pos, Symbol sym) {
289 if (!sym.type.isErroneous()) {
290 Symbol location = sym.location();
291 if (location.kind == MTH &&
292 ((MethodSymbol)location).isStaticOrInstanceInit()) {
293 log.error(pos,
294 Errors.AlreadyDefinedInClinit(kindName(sym),
295 sym,
296 kindName(sym.location()),
297 kindName(sym.location().enclClass()),
298 sym.location().enclClass()));
299 } else {
300 /* dont error if this is a duplicated parameter of a generated canonical constructor
301 * as we should have issued an error for the duplicated fields
302 */
303 if (location.kind != MTH ||
304 ((sym.owner.flags_field & GENERATEDCONSTR) == 0) ||
305 ((sym.owner.flags_field & RECORD) == 0)) {
306 log.error(pos,
307 Errors.AlreadyDefined(kindName(sym),
308 sym,
309 kindName(sym.location()),
310 sym.location()));
311 }
312 }
313 }
314 }
315
316 /** Report array/varargs duplicate declaration
317 */
318 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
319 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
320 log.error(pos, Errors.ArrayAndVarargs(sym1, sym2, sym2.location()));
321 }
322 }
323
324 /* ************************************************************************
325 * duplicate declaration checking
326 *************************************************************************/
327
328 /** Check that variable does not hide variable with same name in
329 * immediately enclosing local scope.
330 * @param pos Position for error reporting.
331 * @param v The symbol.
332 * @param s The scope.
333 */
334 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
335 for (Symbol sym : s.getSymbolsByName(v.name)) {
336 if (sym.owner != v.owner) break;
337 if (sym.kind == VAR &&
338 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
339 v.name != names.error) {
340 duplicateError(pos, sym);
341 return;
342 }
343 }
344 }
345
346 /** Check that a class or interface does not hide a class or
347 * interface with same name in immediately enclosing local scope.
348 * @param pos Position for error reporting.
349 * @param c The symbol.
350 * @param s The scope.
351 */
352 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
353 for (Symbol sym : s.getSymbolsByName(c.name)) {
354 if (sym.owner != c.owner) break;
355 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR) &&
356 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
357 c.name != names.error) {
358 duplicateError(pos, sym);
359 return;
360 }
361 }
362 }
363
364 /** Check that class does not have the same name as one of
365 * its enclosing classes, or as a class defined in its enclosing scope.
366 * return true if class is unique in its enclosing scope.
367 * @param pos Position for error reporting.
368 * @param name The class name.
369 * @param s The enclosing scope.
370 */
371 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
372 for (Symbol sym : s.getSymbolsByName(name, NON_RECURSIVE)) {
373 if (sym.kind == TYP && sym.name != names.error) {
374 duplicateError(pos, sym);
375 return false;
376 }
377 }
378 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
379 if (sym.kind == TYP && sym.name == name && sym.name != names.error &&
380 !sym.isImplicit()) {
381 duplicateError(pos, sym);
382 return true;
383 }
384 }
385 return true;
386 }
387
388 /* *************************************************************************
389 * Class name generation
390 **************************************************************************/
391
392
393 private Map<Pair<Name, Name>, Integer> localClassNameIndexes = new HashMap<>();
394
395 /** Return name of local class.
396 * This is of the form {@code <enclClass> $ n <classname> }
397 * where
398 * enclClass is the flat name of the enclosing class,
399 * classname is the simple name of the local class
400 */
401 public Name localClassName(ClassSymbol c) {
402 Name enclFlatname = c.owner.enclClass().flatname;
403 String enclFlatnameStr = enclFlatname.toString();
404 Pair<Name, Name> key = new Pair<>(enclFlatname, c.name);
405 Integer index = localClassNameIndexes.get(key);
406 for (int i = (index == null) ? 1 : index; ; i++) {
407 Name flatname = names.fromString(enclFlatnameStr
408 + syntheticNameChar + i + c.name);
409 if (getCompiled(c.packge().modle, flatname) == null) {
410 localClassNameIndexes.put(key, i + 1);
411 return flatname;
412 }
413 }
414 }
415
416 public void clearLocalClassNameIndexes(ClassSymbol c) {
417 if (c.owner != null && c.owner.kind != NIL) {
418 localClassNameIndexes.remove(new Pair<>(
419 c.owner.enclClass().flatname, c.name));
420 }
421 }
422
423 public void newRound() {
424 compiled.clear();
425 localClassNameIndexes.clear();
426 }
427
428 public void putCompiled(ClassSymbol csym) {
429 compiled.put(Pair.of(csym.packge().modle, csym.flatname), csym);
430 }
431
432 public ClassSymbol getCompiled(ClassSymbol csym) {
433 return compiled.get(Pair.of(csym.packge().modle, csym.flatname));
434 }
435
436 public ClassSymbol getCompiled(ModuleSymbol msym, Name flatname) {
437 return compiled.get(Pair.of(msym, flatname));
438 }
439
440 public void removeCompiled(ClassSymbol csym) {
441 compiled.remove(Pair.of(csym.packge().modle, csym.flatname));
442 }
443
444 /* *************************************************************************
445 * Type Checking
446 **************************************************************************/
447
448 /**
449 * A check context is an object that can be used to perform compatibility
450 * checks - depending on the check context, meaning of 'compatibility' might
451 * vary significantly.
452 */
453 public interface CheckContext {
454 /**
455 * Is type 'found' compatible with type 'req' in given context
456 */
457 boolean compatible(Type found, Type req, Warner warn);
458 /**
459 * Report a check error
460 */
461 void report(DiagnosticPosition pos, JCDiagnostic details);
462 /**
463 * Obtain a warner for this check context
464 */
465 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req);
466
467 public InferenceContext inferenceContext();
468
469 public DeferredAttr.DeferredAttrContext deferredAttrContext();
470 }
471
472 /**
473 * This class represent a check context that is nested within another check
474 * context - useful to check sub-expressions. The default behavior simply
475 * redirects all method calls to the enclosing check context leveraging
476 * the forwarding pattern.
477 */
478 static class NestedCheckContext implements CheckContext {
479 CheckContext enclosingContext;
480
481 NestedCheckContext(CheckContext enclosingContext) {
482 this.enclosingContext = enclosingContext;
483 }
484
485 public boolean compatible(Type found, Type req, Warner warn) {
486 return enclosingContext.compatible(found, req, warn);
487 }
488
489 public void report(DiagnosticPosition pos, JCDiagnostic details) {
490 enclosingContext.report(pos, details);
491 }
492
493 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
494 return enclosingContext.checkWarner(pos, found, req);
495 }
496
497 public InferenceContext inferenceContext() {
498 return enclosingContext.inferenceContext();
499 }
500
501 public DeferredAttrContext deferredAttrContext() {
502 return enclosingContext.deferredAttrContext();
503 }
504 }
505
506 /**
507 * Check context to be used when evaluating assignment/return statements
508 */
509 CheckContext basicHandler = new CheckContext() {
510 public void report(DiagnosticPosition pos, JCDiagnostic details) {
511 log.error(pos, Errors.ProbFoundReq(details));
512 }
513 public boolean compatible(Type found, Type req, Warner warn) {
514 return types.isAssignable(found, req, warn);
515 }
516
517 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
518 return convertWarner(pos, found, req);
519 }
520
521 public InferenceContext inferenceContext() {
522 return infer.emptyContext;
523 }
524
525 public DeferredAttrContext deferredAttrContext() {
526 return deferredAttr.emptyDeferredAttrContext;
527 }
528
529 @Override
530 public String toString() {
531 return "CheckContext: basicHandler";
532 }
533 };
534
535 /** Check that a given type is assignable to a given proto-type.
536 * If it is, return the type, otherwise return errType.
537 * @param pos Position to be used for error reporting.
538 * @param found The type that was found.
539 * @param req The type that was required.
540 */
541 public Type checkType(DiagnosticPosition pos, Type found, Type req) {
542 return checkType(pos, found, req, basicHandler);
543 }
544
545 Type checkType(final DiagnosticPosition pos, final Type found, final Type req, final CheckContext checkContext) {
546 final InferenceContext inferenceContext = checkContext.inferenceContext();
547 if (inferenceContext.free(req) || inferenceContext.free(found)) {
548 inferenceContext.addFreeTypeListener(List.of(req, found),
549 solvedContext -> checkType(pos, solvedContext.asInstType(found), solvedContext.asInstType(req), checkContext));
550 }
551 if (req.hasTag(ERROR))
552 return req;
553 if (req.hasTag(NONE))
554 return found;
555 if (checkContext.compatible(found, req, checkContext.checkWarner(pos, found, req))) {
556 return found;
557 } else {
558 if (found.isNumeric() && req.isNumeric()) {
559 checkContext.report(pos, diags.fragment(Fragments.PossibleLossOfPrecision(found, req)));
560 return types.createErrorType(found);
561 }
562 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
563 return types.createErrorType(found);
564 }
565 }
566
567 /** Check that a given type can be cast to a given target type.
568 * Return the result of the cast.
569 * @param pos Position to be used for error reporting.
570 * @param found The type that is being cast.
571 * @param req The target type of the cast.
572 */
573 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
574 return checkCastable(pos, found, req, basicHandler);
575 }
576 Type checkCastable(DiagnosticPosition pos, Type found, Type req, CheckContext checkContext) {
577 if (types.isCastable(found, req, castWarner(pos, found, req))) {
578 return req;
579 } else {
580 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
581 return types.createErrorType(found);
582 }
583 }
584
585 /** Check for redundant casts (i.e. where source type is a subtype of target type)
586 * The problem should only be reported for non-292 cast
587 */
588 public void checkRedundantCast(Env<AttrContext> env, final JCTypeCast tree) {
589 if (!tree.type.isErroneous()
590 && types.isSameType(tree.expr.type, tree.clazz.type)
591 && !(ignoreAnnotatedCasts && TreeInfo.containsTypeAnnotation(tree.clazz))
592 && !is292targetTypeCast(tree)) {
593 log.warning(tree.pos(), LintWarnings.RedundantCast(tree.clazz.type));
594 }
595 }
596 //where
597 private boolean is292targetTypeCast(JCTypeCast tree) {
598 boolean is292targetTypeCast = false;
599 JCExpression expr = TreeInfo.skipParens(tree.expr);
600 if (expr.hasTag(APPLY)) {
601 JCMethodInvocation apply = (JCMethodInvocation)expr;
602 Symbol sym = TreeInfo.symbol(apply.meth);
603 is292targetTypeCast = sym != null &&
604 sym.kind == MTH &&
605 (sym.flags() & HYPOTHETICAL) != 0;
606 }
607 return is292targetTypeCast;
608 }
609
610 private static final boolean ignoreAnnotatedCasts = true;
611
612 /** Check that a type is within some bounds.
613 *
614 * Used in TypeApply to verify that, e.g., X in {@code V<X>} is a valid
615 * type argument.
616 * @param a The type that should be bounded by bs.
617 * @param bound The bound.
618 */
619 private boolean checkExtends(Type a, Type bound) {
620 if (a.isUnbound()) {
621 return true;
622 } else if (!a.hasTag(WILDCARD)) {
623 a = types.cvarUpperBound(a);
624 return types.isSubtype(a, bound);
625 } else if (a.isExtendsBound()) {
626 return types.isCastable(bound, types.wildUpperBound(a), types.noWarnings);
627 } else if (a.isSuperBound()) {
628 return !types.notSoftSubtype(types.wildLowerBound(a), bound);
629 }
630 return true;
631 }
632
633 /** Check that type is different from 'void'.
634 * @param pos Position to be used for error reporting.
635 * @param t The type to be checked.
636 */
637 Type checkNonVoid(DiagnosticPosition pos, Type t) {
638 if (t.hasTag(VOID)) {
639 log.error(pos, Errors.VoidNotAllowedHere);
640 return types.createErrorType(t);
641 } else {
642 return t;
643 }
644 }
645
646 Type checkClassOrArrayType(DiagnosticPosition pos, Type t) {
647 if (!t.hasTag(CLASS) && !t.hasTag(ARRAY) && !t.hasTag(ERROR)) {
648 return typeTagError(pos,
649 diags.fragment(Fragments.TypeReqClassArray),
650 asTypeParam(t));
651 } else {
652 return t;
653 }
654 }
655
656 /** Check that type is a class or interface type.
657 * @param pos Position to be used for error reporting.
658 * @param t The type to be checked.
659 */
660 Type checkClassType(DiagnosticPosition pos, Type t) {
661 if (!t.hasTag(CLASS) && !t.hasTag(ERROR)) {
662 return typeTagError(pos,
663 diags.fragment(Fragments.TypeReqClass),
664 asTypeParam(t));
665 } else {
666 return t;
667 }
668 }
669 //where
670 private Object asTypeParam(Type t) {
671 return (t.hasTag(TYPEVAR))
672 ? diags.fragment(Fragments.TypeParameter(t))
673 : t;
674 }
675
676 void checkConstraintsOfValueClass(JCClassDecl tree, ClassSymbol c) {
677 DiagnosticPosition pos = tree.pos();
678 for (Type st : types.closure(c.type)) {
679 if (st == null || st.tsym == null || st.tsym.kind == ERR)
680 continue;
681 if (st.tsym == syms.objectType.tsym || st.tsym == syms.recordType.tsym || st.isInterface())
682 continue;
683 if (!st.tsym.isAbstract()) {
684 if (c != st.tsym) {
685 log.error(pos, Errors.ConcreteSupertypeForValueClass(c, st));
686 }
687 continue;
688 }
689 // dealing with an abstract value or value super class below.
690 for (Symbol s : st.tsym.members().getSymbols(NON_RECURSIVE)) {
691 if (s.kind == MTH) {
692 if ((s.flags() & (SYNCHRONIZED | STATIC)) == SYNCHRONIZED) {
693 log.error(pos, Errors.SuperClassMethodCannotBeSynchronized(s, c, st));
694 }
695 break;
696 }
697 }
698 }
699 }
700
701 /** Check that type is a valid qualifier for a constructor reference expression
702 */
703 Type checkConstructorRefType(DiagnosticPosition pos, Type t) {
704 t = checkClassOrArrayType(pos, t);
705 if (t.hasTag(CLASS)) {
706 if ((t.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
707 log.error(pos, Errors.AbstractCantBeInstantiated(t.tsym));
708 t = types.createErrorType(t);
709 } else if ((t.tsym.flags() & ENUM) != 0) {
710 log.error(pos, Errors.EnumCantBeInstantiated);
711 t = types.createErrorType(t);
712 } else {
713 t = checkClassType(pos, t, true);
714 }
715 } else if (t.hasTag(ARRAY)) {
716 if (!types.isReifiable(((ArrayType)t).elemtype)) {
717 log.error(pos, Errors.GenericArrayCreation);
718 t = types.createErrorType(t);
719 }
720 }
721 return t;
722 }
723
724 /** Check that type is a class or interface type.
725 * @param pos Position to be used for error reporting.
726 * @param t The type to be checked.
727 * @param noBounds True if type bounds are illegal here.
728 */
729 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
730 t = checkClassType(pos, t);
731 if (noBounds && t.isParameterized()) {
732 List<Type> args = t.getTypeArguments();
733 while (args.nonEmpty()) {
734 if (args.head.hasTag(WILDCARD))
735 return typeTagError(pos,
736 diags.fragment(Fragments.TypeReqExact),
737 args.head);
738 args = args.tail;
739 }
740 }
741 return t;
742 }
743
744 /** Check that type is a reference type, i.e. a class, interface or array type
745 * or a type variable.
746 * @param pos Position to be used for error reporting.
747 * @param t The type to be checked.
748 */
749 Type checkRefType(DiagnosticPosition pos, Type t) {
750 if (t.isReference())
751 return t;
752 else
753 return typeTagError(pos,
754 diags.fragment(Fragments.TypeReqRef),
755 t);
756 }
757
758 /** Check that type is an identity type, i.e. not a value type.
759 * When not discernible statically, give it the benefit of doubt
760 * and defer to runtime.
761 *
762 * @param pos Position to be used for error reporting.
763 * @param t The type to be checked.
764 */
765 boolean checkIdentityType(DiagnosticPosition pos, Type t) {
766 if (t.hasTag(TYPEVAR)) {
767 t = types.skipTypeVars(t, false);
768 }
769 if (t.isIntersection()) {
770 IntersectionClassType ict = (IntersectionClassType)t;
771 boolean result = true;
772 for (Type component : ict.getExplicitComponents()) {
773 result &= checkIdentityType(pos, component);
774 }
775 return result;
776 }
777 if (t.isPrimitive() || (t.isValueClass() && !t.tsym.isAbstract())) {
778 typeTagError(pos, diags.fragment(Fragments.TypeReqIdentity), t);
779 return false;
780 }
781 return true;
782 }
783
784 /** Check that each type is a reference type, i.e. a class, interface or array type
785 * or a type variable.
786 * @param trees Original trees, used for error reporting.
787 * @param types The types to be checked.
788 */
789 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
790 List<JCExpression> tl = trees;
791 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
792 l.head = checkRefType(tl.head.pos(), l.head);
793 tl = tl.tail;
794 }
795 return types;
796 }
797
798 /** Check that type is a null or reference type.
799 * @param pos Position to be used for error reporting.
800 * @param t The type to be checked.
801 */
802 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
803 if (t.isReference() || t.hasTag(BOT))
804 return t;
805 else
806 return typeTagError(pos,
807 diags.fragment(Fragments.TypeReqRef),
808 t);
809 }
810
811 /** Check that flag set does not contain elements of two conflicting sets. s
812 * Return true if it doesn't.
813 * @param pos Position to be used for error reporting.
814 * @param flags The set of flags to be checked.
815 * @param set1 Conflicting flags set #1.
816 * @param set2 Conflicting flags set #2.
817 */
818 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
819 if ((flags & set1) != 0 && (flags & set2) != 0) {
820 log.error(pos,
821 Errors.IllegalCombinationOfModifiers(asFlagSet(TreeInfo.firstFlag(flags & set1)),
822 asFlagSet(TreeInfo.firstFlag(flags & set2))));
823 return false;
824 } else
825 return true;
826 }
827
828 /** Check that usage of diamond operator is correct (i.e. diamond should not
829 * be used with non-generic classes or in anonymous class creation expressions)
830 */
831 Type checkDiamond(JCNewClass tree, Type t) {
832 if (!TreeInfo.isDiamond(tree) ||
833 t.isErroneous()) {
834 return checkClassType(tree.clazz.pos(), t, true);
835 } else {
836 if (tree.def != null && !Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.allowedInSource(source)) {
837 log.error(DiagnosticFlag.SOURCE_LEVEL, tree.clazz.pos(),
838 Errors.CantApplyDiamond1(t, Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.fragment(source.name)));
839 }
840 if (t.tsym.type.getTypeArguments().isEmpty()) {
841 log.error(tree.clazz.pos(),
842 Errors.CantApplyDiamond1(t,
843 Fragments.DiamondNonGeneric(t)));
844 return types.createErrorType(t);
845 } else if (tree.typeargs != null &&
846 tree.typeargs.nonEmpty()) {
847 log.error(tree.clazz.pos(),
848 Errors.CantApplyDiamond1(t,
849 Fragments.DiamondAndExplicitParams(t)));
850 return types.createErrorType(t);
851 } else {
852 return t;
853 }
854 }
855 }
856
857 /** Check that the type inferred using the diamond operator does not contain
858 * non-denotable types such as captured types or intersection types.
859 * @param t the type inferred using the diamond operator
860 * @return the (possibly empty) list of non-denotable types.
861 */
862 List<Type> checkDiamondDenotable(ClassType t) {
863 ListBuffer<Type> buf = new ListBuffer<>();
864 for (Type arg : t.allparams()) {
865 if (!checkDenotable(arg)) {
866 buf.append(arg);
867 }
868 }
869 return buf.toList();
870 }
871
872 public boolean checkDenotable(Type t) {
873 return denotableChecker.visit(t, null);
874 }
875 // where
876
877 /** diamondTypeChecker: A type visitor that descends down the given type looking for non-denotable
878 * types. The visit methods return false as soon as a non-denotable type is encountered and true
879 * otherwise.
880 */
881 private static final Types.SimpleVisitor<Boolean, Void> denotableChecker = new Types.SimpleVisitor<Boolean, Void>() {
882 @Override
883 public Boolean visitType(Type t, Void s) {
884 return true;
885 }
886 @Override
887 public Boolean visitClassType(ClassType t, Void s) {
888 if (t.isUnion() || t.isIntersection()) {
889 return false;
890 }
891 for (Type targ : t.allparams()) {
892 if (!visit(targ, s)) {
893 return false;
894 }
895 }
896 return true;
897 }
898
899 @Override
900 public Boolean visitTypeVar(TypeVar t, Void s) {
901 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
902 (i.e cannot have been produced by inference (18.4))
903 */
904 return (t.tsym.flags() & SYNTHETIC) == 0;
905 }
906
907 @Override
908 public Boolean visitCapturedType(CapturedType t, Void s) {
909 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
910 (i.e cannot have been produced by capture conversion (5.1.10))
911 */
912 return false;
913 }
914
915 @Override
916 public Boolean visitArrayType(ArrayType t, Void s) {
917 return visit(t.elemtype, s);
918 }
919
920 @Override
921 public Boolean visitWildcardType(WildcardType t, Void s) {
922 return visit(t.type, s);
923 }
924 };
925
926 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
927 MethodSymbol m = tree.sym;
928 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
929 Type varargElemType = null;
930 if (m.isVarArgs()) {
931 varargElemType = types.elemtype(tree.params.last().type);
932 }
933 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
934 if (varargElemType != null) {
935 JCDiagnostic msg = Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ?
936 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargs(m)) :
937 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargsFinalOnly(m));
938 log.error(tree,
939 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
940 msg));
941 } else {
942 log.error(tree,
943 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
944 Fragments.VarargsTrustmeOnNonVarargsMeth(m)));
945 }
946 } else if (hasTrustMeAnno && varargElemType != null &&
947 types.isReifiable(varargElemType)) {
948 log.warning(tree.pos(), LintWarnings.VarargsRedundantTrustmeAnno(
949 syms.trustMeType.tsym,
950 diags.fragment(Fragments.VarargsTrustmeOnReifiableVarargs(varargElemType))));
951 }
952 else if (!hasTrustMeAnno && varargElemType != null &&
953 !types.isReifiable(varargElemType)) {
954 warnUnchecked(tree.params.head.pos(), LintWarnings.UncheckedVarargsNonReifiableType(varargElemType));
955 }
956 }
957 //where
958 private boolean isTrustMeAllowedOnMethod(Symbol s) {
959 return (s.flags() & VARARGS) != 0 &&
960 (s.isConstructor() ||
961 (s.flags() & (STATIC | FINAL |
962 (Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ? PRIVATE : 0) )) != 0);
963 }
964
965 Type checkLocalVarType(DiagnosticPosition pos, Type t, Name name) {
966 //check that resulting type is not the null type
967 if (t.hasTag(BOT)) {
968 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferNull));
969 return types.createErrorType(t);
970 } else if (t.hasTag(VOID)) {
971 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferVoid));
972 return types.createErrorType(t);
973 }
974
975 //upward project the initializer type
976 return types.upward(t, types.captures(t)).baseType();
977 }
978
979 Type checkMethod(final Type mtype,
980 final Symbol sym,
981 final Env<AttrContext> env,
982 final List<JCExpression> argtrees,
983 final List<Type> argtypes,
984 final boolean useVarargs,
985 InferenceContext inferenceContext) {
986 // System.out.println("call : " + env.tree);
987 // System.out.println("method : " + owntype);
988 // System.out.println("actuals: " + argtypes);
989 if (inferenceContext.free(mtype)) {
990 inferenceContext.addFreeTypeListener(List.of(mtype),
991 solvedContext -> checkMethod(solvedContext.asInstType(mtype), sym, env, argtrees, argtypes, useVarargs, solvedContext));
992 return mtype;
993 }
994 Type owntype = mtype;
995 List<Type> formals = owntype.getParameterTypes();
996 List<Type> nonInferred = sym.type.getParameterTypes();
997 if (nonInferred.length() != formals.length()) nonInferred = formals;
998 Type last = useVarargs ? formals.last() : null;
999 if (sym.name == names.init && sym.owner == syms.enumSym) {
1000 formals = formals.tail.tail;
1001 nonInferred = nonInferred.tail.tail;
1002 }
1003 if ((sym.flags() & ANONCONSTR_BASED) != 0) {
1004 formals = formals.tail;
1005 nonInferred = nonInferred.tail;
1006 }
1007 List<JCExpression> args = argtrees;
1008 if (args != null) {
1009 //this is null when type-checking a method reference
1010 while (formals.head != last) {
1011 JCTree arg = args.head;
1012 Warner warn = convertWarner(arg.pos(), arg.type, nonInferred.head);
1013 assertConvertible(arg, arg.type, formals.head, warn);
1014 args = args.tail;
1015 formals = formals.tail;
1016 nonInferred = nonInferred.tail;
1017 }
1018 if (useVarargs) {
1019 Type varArg = types.elemtype(last);
1020 while (args.tail != null) {
1021 JCTree arg = args.head;
1022 Warner warn = convertWarner(arg.pos(), arg.type, varArg);
1023 assertConvertible(arg, arg.type, varArg, warn);
1024 args = args.tail;
1025 }
1026 } else if ((sym.flags() & (VARARGS | SIGNATURE_POLYMORPHIC)) == VARARGS) {
1027 // non-varargs call to varargs method
1028 Type varParam = owntype.getParameterTypes().last();
1029 Type lastArg = argtypes.last();
1030 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
1031 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
1032 log.warning(argtrees.last().pos(),
1033 Warnings.InexactNonVarargsCall(types.elemtype(varParam),varParam));
1034 }
1035 }
1036 if (useVarargs) {
1037 Type argtype = owntype.getParameterTypes().last();
1038 if (!types.isReifiable(argtype) &&
1039 (sym.baseSymbol().attribute(syms.trustMeType.tsym) == null ||
1040 !isTrustMeAllowedOnMethod(sym))) {
1041 warnUnchecked(env.tree.pos(), LintWarnings.UncheckedGenericArrayCreation(argtype));
1042 }
1043 TreeInfo.setVarargsElement(env.tree, types.elemtype(argtype));
1044 }
1045 return owntype;
1046 }
1047 //where
1048 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
1049 if (types.isConvertible(actual, formal, warn))
1050 return;
1051
1052 if (formal.isCompound()
1053 && types.isSubtype(actual, types.supertype(formal))
1054 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
1055 return;
1056 }
1057
1058 /**
1059 * Check that type 't' is a valid instantiation of a generic class
1060 * (see JLS 4.5)
1061 *
1062 * @param t class type to be checked
1063 * @return true if 't' is well-formed
1064 */
1065 public boolean checkValidGenericType(Type t) {
1066 return firstIncompatibleTypeArg(t) == null;
1067 }
1068 //WHERE
1069 private Type firstIncompatibleTypeArg(Type type) {
1070 List<Type> formals = type.tsym.type.allparams();
1071 List<Type> actuals = type.allparams();
1072 List<Type> args = type.getTypeArguments();
1073 List<Type> forms = type.tsym.type.getTypeArguments();
1074 ListBuffer<Type> bounds_buf = new ListBuffer<>();
1075
1076 // For matching pairs of actual argument types `a' and
1077 // formal type parameters with declared bound `b' ...
1078 while (args.nonEmpty() && forms.nonEmpty()) {
1079 // exact type arguments needs to know their
1080 // bounds (for upper and lower bound
1081 // calculations). So we create new bounds where
1082 // type-parameters are replaced with actuals argument types.
1083 bounds_buf.append(types.subst(forms.head.getUpperBound(), formals, actuals));
1084 args = args.tail;
1085 forms = forms.tail;
1086 }
1087
1088 args = type.getTypeArguments();
1089 List<Type> tvars_cap = types.substBounds(formals,
1090 formals,
1091 types.capture(type).allparams());
1092 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
1093 // Let the actual arguments know their bound
1094 args.head.withTypeVar((TypeVar)tvars_cap.head);
1095 args = args.tail;
1096 tvars_cap = tvars_cap.tail;
1097 }
1098
1099 args = type.getTypeArguments();
1100 List<Type> bounds = bounds_buf.toList();
1101
1102 while (args.nonEmpty() && bounds.nonEmpty()) {
1103 Type actual = args.head;
1104 if (!isTypeArgErroneous(actual) &&
1105 !bounds.head.isErroneous() &&
1106 !checkExtends(actual, bounds.head)) {
1107 return args.head;
1108 }
1109 args = args.tail;
1110 bounds = bounds.tail;
1111 }
1112
1113 args = type.getTypeArguments();
1114 bounds = bounds_buf.toList();
1115
1116 for (Type arg : types.capture(type).getTypeArguments()) {
1117 if (arg.hasTag(TYPEVAR) &&
1118 arg.getUpperBound().isErroneous() &&
1119 !bounds.head.isErroneous() &&
1120 !isTypeArgErroneous(args.head)) {
1121 return args.head;
1122 }
1123 bounds = bounds.tail;
1124 args = args.tail;
1125 }
1126
1127 return null;
1128 }
1129 //where
1130 boolean isTypeArgErroneous(Type t) {
1131 return isTypeArgErroneous.visit(t);
1132 }
1133
1134 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() {
1135 public Boolean visitType(Type t, Void s) {
1136 return t.isErroneous();
1137 }
1138 @Override
1139 public Boolean visitTypeVar(TypeVar t, Void s) {
1140 return visit(t.getUpperBound());
1141 }
1142 @Override
1143 public Boolean visitCapturedType(CapturedType t, Void s) {
1144 return visit(t.getUpperBound()) ||
1145 visit(t.getLowerBound());
1146 }
1147 @Override
1148 public Boolean visitWildcardType(WildcardType t, Void s) {
1149 return visit(t.type);
1150 }
1151 };
1152
1153 /** Check that given modifiers are legal for given symbol and
1154 * return modifiers together with any implicit modifiers for that symbol.
1155 * Warning: we can't use flags() here since this method
1156 * is called during class enter, when flags() would cause a premature
1157 * completion.
1158 * @param flags The set of modifiers given in a definition.
1159 * @param sym The defined symbol.
1160 * @param tree The declaration
1161 */
1162 long checkFlags(long flags, Symbol sym, JCTree tree) {
1163 final DiagnosticPosition pos = tree.pos();
1164 long mask;
1165 long implicit = 0;
1166
1167 switch (sym.kind) {
1168 case VAR:
1169 if (TreeInfo.isReceiverParam(tree))
1170 mask = ReceiverParamFlags;
1171 else if (sym.owner.kind != TYP)
1172 mask = LocalVarFlags;
1173 else if ((sym.owner.flags_field & INTERFACE) != 0)
1174 mask = implicit = InterfaceVarFlags;
1175 else {
1176 boolean isInstanceField = (flags & STATIC) == 0;
1177 boolean isInstanceFieldOfValueClass = isInstanceField && sym.owner.type.isValueClass();
1178 boolean isRecordField = isInstanceField && (sym.owner.flags_field & RECORD) != 0;
1179 if (allowValueClasses && (isInstanceFieldOfValueClass || isRecordField)) {
1180 implicit |= FINAL | STRICT;
1181 mask = ValueFieldFlags;
1182 } else {
1183 mask = VarFlags;
1184 }
1185 }
1186 break;
1187 case MTH:
1188 if (sym.name == names.init) {
1189 if ((sym.owner.flags_field & ENUM) != 0) {
1190 // enum constructors cannot be declared public or
1191 // protected and must be implicitly or explicitly
1192 // private
1193 implicit = PRIVATE;
1194 mask = PRIVATE;
1195 } else
1196 mask = ConstructorFlags;
1197 } else if ((sym.owner.flags_field & INTERFACE) != 0) {
1198 if ((sym.owner.flags_field & ANNOTATION) != 0) {
1199 mask = AnnotationTypeElementMask;
1200 implicit = PUBLIC | ABSTRACT;
1201 } else if ((flags & (DEFAULT | STATIC | PRIVATE)) != 0) {
1202 mask = InterfaceMethodMask;
1203 implicit = (flags & PRIVATE) != 0 ? 0 : PUBLIC;
1204 if ((flags & DEFAULT) != 0) {
1205 implicit |= ABSTRACT;
1206 }
1207 } else {
1208 mask = implicit = InterfaceMethodFlags;
1209 }
1210 } else if ((sym.owner.flags_field & RECORD) != 0) {
1211 mask = ((sym.owner.flags_field & VALUE_CLASS) != 0 && (flags & Flags.STATIC) == 0) ?
1212 RecordMethodFlags & ~SYNCHRONIZED : RecordMethodFlags;
1213 } else {
1214 // value objects do not have an associated monitor/lock
1215 mask = ((sym.owner.flags_field & VALUE_CLASS) != 0 && (flags & Flags.STATIC) == 0) ?
1216 MethodFlags & ~SYNCHRONIZED : MethodFlags;
1217 }
1218 if ((flags & STRICTFP) != 0) {
1219 log.warning(tree.pos(), LintWarnings.Strictfp);
1220 }
1221 // Imply STRICTFP if owner has STRICTFP set.
1222 if (((flags|implicit) & Flags.ABSTRACT) == 0 ||
1223 ((flags) & Flags.DEFAULT) != 0)
1224 implicit |= sym.owner.flags_field & STRICTFP;
1225 break;
1226 case TYP:
1227 if (sym.owner.kind.matches(KindSelector.VAL_MTH) ||
1228 (sym.isDirectlyOrIndirectlyLocal() && (flags & ANNOTATION) != 0)) {
1229 boolean implicitlyStatic = !sym.isAnonymous() &&
1230 ((flags & RECORD) != 0 || (flags & ENUM) != 0 || (flags & INTERFACE) != 0);
1231 boolean staticOrImplicitlyStatic = (flags & STATIC) != 0 || implicitlyStatic;
1232 // local statics are allowed only if records are allowed too
1233 mask = staticOrImplicitlyStatic && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedStaticLocalClassFlags : ExtendedLocalClassFlags;
1234 implicit = implicitlyStatic ? STATIC : implicit;
1235 } else if (sym.owner.kind == TYP) {
1236 // statics in inner classes are allowed only if records are allowed too
1237 mask = ((flags & STATIC) != 0) && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedMemberStaticClassFlags : ExtendedMemberClassFlags;
1238 if (sym.owner.owner.kind == PCK ||
1239 (sym.owner.flags_field & STATIC) != 0) {
1240 mask |= STATIC;
1241 } else if (!allowRecords && ((flags & ENUM) != 0 || (flags & RECORD) != 0)) {
1242 log.error(pos, Errors.StaticDeclarationNotAllowedInInnerClasses);
1243 }
1244 // Nested interfaces and enums are always STATIC (Spec ???)
1245 if ((flags & (INTERFACE | ENUM | RECORD)) != 0 ) implicit = STATIC;
1246 } else {
1247 mask = ExtendedClassFlags;
1248 }
1249 if ((flags & (VALUE_CLASS | SEALED | ABSTRACT)) == (VALUE_CLASS | SEALED) ||
1250 (flags & (VALUE_CLASS | NON_SEALED | ABSTRACT)) == (VALUE_CLASS | NON_SEALED)) {
1251 log.error(pos, Errors.NonAbstractValueClassCantBeSealedOrNonSealed);
1252 }
1253 // Interfaces are always ABSTRACT
1254 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
1255
1256 if ((flags & (INTERFACE | VALUE_CLASS)) == 0) {
1257 implicit |= IDENTITY_TYPE;
1258 }
1259
1260 if ((flags & ENUM) != 0) {
1261 // enums can't be declared abstract, final, sealed or non-sealed or value
1262 mask &= ~(ABSTRACT | FINAL | SEALED | NON_SEALED | VALUE_CLASS);
1263 implicit |= implicitEnumFinalFlag(tree);
1264 }
1265 if ((flags & RECORD) != 0) {
1266 // records can't be declared abstract
1267 mask &= ~ABSTRACT;
1268 implicit |= FINAL;
1269 }
1270 if ((flags & STRICTFP) != 0) {
1271 log.warning(tree.pos(), LintWarnings.Strictfp);
1272 }
1273 // Imply STRICTFP if owner has STRICTFP set.
1274 implicit |= sym.owner.flags_field & STRICTFP;
1275
1276 // concrete value classes are implicitly final
1277 if ((flags & (ABSTRACT | INTERFACE | VALUE_CLASS)) == VALUE_CLASS) {
1278 implicit |= FINAL;
1279 }
1280 break;
1281 default:
1282 throw new AssertionError();
1283 }
1284 long illegal = flags & ExtendedStandardFlags & ~mask;
1285 if (illegal != 0) {
1286 if ((illegal & INTERFACE) != 0) {
1287 log.error(pos, ((flags & ANNOTATION) != 0) ? Errors.AnnotationDeclNotAllowedHere : Errors.IntfNotAllowedHere);
1288 mask |= INTERFACE;
1289 }
1290 else {
1291 log.error(pos,
1292 Errors.ModNotAllowedHere(asFlagSet(illegal)));
1293 }
1294 } else if ((sym.kind == TYP ||
1295 // ISSUE: Disallowing abstract&private is no longer appropriate
1296 // in the presence of inner classes. Should it be deleted here?
1297 checkDisjoint(pos, flags,
1298 ABSTRACT,
1299 PRIVATE | STATIC | DEFAULT))
1300 &&
1301 checkDisjoint(pos, flags,
1302 STATIC | PRIVATE,
1303 DEFAULT)
1304 &&
1305 checkDisjoint(pos, flags,
1306 ABSTRACT | INTERFACE,
1307 FINAL | NATIVE | SYNCHRONIZED)
1308 &&
1309 checkDisjoint(pos, flags,
1310 PUBLIC,
1311 PRIVATE | PROTECTED)
1312 &&
1313 checkDisjoint(pos, flags,
1314 PRIVATE,
1315 PUBLIC | PROTECTED)
1316 &&
1317 // we are using `implicit` here as instance fields of value classes are implicitly final
1318 checkDisjoint(pos, flags | implicit,
1319 FINAL,
1320 VOLATILE)
1321 &&
1322 (sym.kind == TYP ||
1323 checkDisjoint(pos, flags,
1324 ABSTRACT | NATIVE,
1325 STRICTFP))
1326 && checkDisjoint(pos, flags,
1327 FINAL,
1328 SEALED | NON_SEALED)
1329 && checkDisjoint(pos, flags,
1330 SEALED,
1331 FINAL | NON_SEALED)
1332 && checkDisjoint(pos, flags,
1333 SEALED,
1334 ANNOTATION)
1335 && checkDisjoint(pos, flags,
1336 VALUE_CLASS,
1337 ANNOTATION)
1338 && checkDisjoint(pos, flags,
1339 VALUE_CLASS,
1340 INTERFACE) ) {
1341 // skip
1342 }
1343 return flags & (mask | ~ExtendedStandardFlags) | implicit;
1344 }
1345
1346 /** Determine if this enum should be implicitly final.
1347 *
1348 * If the enum has no specialized enum constants, it is final.
1349 *
1350 * If the enum does have specialized enum constants, it is
1351 * <i>not</i> final.
1352 */
1353 private long implicitEnumFinalFlag(JCTree tree) {
1354 if (!tree.hasTag(CLASSDEF)) return 0;
1355 class SpecialTreeVisitor extends JCTree.Visitor {
1356 boolean specialized;
1357 SpecialTreeVisitor() {
1358 this.specialized = false;
1359 }
1360
1361 @Override
1362 public void visitTree(JCTree tree) { /* no-op */ }
1363
1364 @Override
1365 public void visitVarDef(JCVariableDecl tree) {
1366 if ((tree.mods.flags & ENUM) != 0) {
1367 if (tree.init instanceof JCNewClass newClass && newClass.def != null) {
1368 specialized = true;
1369 }
1370 }
1371 }
1372 }
1373
1374 SpecialTreeVisitor sts = new SpecialTreeVisitor();
1375 JCClassDecl cdef = (JCClassDecl) tree;
1376 for (JCTree defs: cdef.defs) {
1377 defs.accept(sts);
1378 if (sts.specialized) return allowSealed ? SEALED : 0;
1379 }
1380 return FINAL;
1381 }
1382
1383 /* *************************************************************************
1384 * Type Validation
1385 **************************************************************************/
1386
1387 /** Validate a type expression. That is,
1388 * check that all type arguments of a parametric type are within
1389 * their bounds. This must be done in a second phase after type attribution
1390 * since a class might have a subclass as type parameter bound. E.g:
1391 *
1392 * <pre>{@code
1393 * class B<A extends C> { ... }
1394 * class C extends B<C> { ... }
1395 * }</pre>
1396 *
1397 * and we can't make sure that the bound is already attributed because
1398 * of possible cycles.
1399 *
1400 * Visitor method: Validate a type expression, if it is not null, catching
1401 * and reporting any completion failures.
1402 */
1403 void validate(JCTree tree, Env<AttrContext> env) {
1404 validate(tree, env, true);
1405 }
1406 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1407 new Validator(env).validateTree(tree, checkRaw, true);
1408 }
1409
1410 /** Visitor method: Validate a list of type expressions.
1411 */
1412 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1413 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1414 validate(l.head, env);
1415 }
1416
1417 /** A visitor class for type validation.
1418 */
1419 class Validator extends JCTree.Visitor {
1420
1421 boolean checkRaw;
1422 boolean isOuter;
1423 Env<AttrContext> env;
1424
1425 Validator(Env<AttrContext> env) {
1426 this.env = env;
1427 }
1428
1429 @Override
1430 public void visitTypeArray(JCArrayTypeTree tree) {
1431 validateTree(tree.elemtype, checkRaw, isOuter);
1432 }
1433
1434 @Override
1435 public void visitTypeApply(JCTypeApply tree) {
1436 if (tree.type.hasTag(CLASS)) {
1437 List<JCExpression> args = tree.arguments;
1438 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1439
1440 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1441 if (incompatibleArg != null) {
1442 for (JCTree arg : tree.arguments) {
1443 if (arg.type == incompatibleArg) {
1444 log.error(arg, Errors.NotWithinBounds(incompatibleArg, forms.head));
1445 }
1446 forms = forms.tail;
1447 }
1448 }
1449
1450 forms = tree.type.tsym.type.getTypeArguments();
1451
1452 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1453
1454 // For matching pairs of actual argument types `a' and
1455 // formal type parameters with declared bound `b' ...
1456 while (args.nonEmpty() && forms.nonEmpty()) {
1457 validateTree(args.head,
1458 !(isOuter && is_java_lang_Class),
1459 false);
1460 args = args.tail;
1461 forms = forms.tail;
1462 }
1463
1464 // Check that this type is either fully parameterized, or
1465 // not parameterized at all.
1466 if (tree.type.getEnclosingType().isRaw())
1467 log.error(tree.pos(), Errors.ImproperlyFormedTypeInnerRawParam);
1468 if (tree.clazz.hasTag(SELECT))
1469 visitSelectInternal((JCFieldAccess)tree.clazz);
1470 }
1471 }
1472
1473 @Override
1474 public void visitTypeParameter(JCTypeParameter tree) {
1475 validateTrees(tree.bounds, true, isOuter);
1476 checkClassBounds(tree.pos(), tree.type);
1477 }
1478
1479 @Override
1480 public void visitWildcard(JCWildcard tree) {
1481 if (tree.inner != null)
1482 validateTree(tree.inner, true, isOuter);
1483 }
1484
1485 @Override
1486 public void visitSelect(JCFieldAccess tree) {
1487 if (tree.type.hasTag(CLASS)) {
1488 visitSelectInternal(tree);
1489
1490 // Check that this type is either fully parameterized, or
1491 // not parameterized at all.
1492 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1493 log.error(tree.pos(), Errors.ImproperlyFormedTypeParamMissing);
1494 }
1495 }
1496
1497 public void visitSelectInternal(JCFieldAccess tree) {
1498 if (tree.type.tsym.isStatic() &&
1499 tree.selected.type.isParameterized()) {
1500 // The enclosing type is not a class, so we are
1501 // looking at a static member type. However, the
1502 // qualifying expression is parameterized.
1503 log.error(tree.pos(), Errors.CantSelectStaticClassFromParamType);
1504 } else {
1505 // otherwise validate the rest of the expression
1506 tree.selected.accept(this);
1507 }
1508 }
1509
1510 @Override
1511 public void visitAnnotatedType(JCAnnotatedType tree) {
1512 tree.underlyingType.accept(this);
1513 }
1514
1515 @Override
1516 public void visitTypeIdent(JCPrimitiveTypeTree that) {
1517 if (that.type.hasTag(TypeTag.VOID)) {
1518 log.error(that.pos(), Errors.VoidNotAllowedHere);
1519 }
1520 super.visitTypeIdent(that);
1521 }
1522
1523 /** Default visitor method: do nothing.
1524 */
1525 @Override
1526 public void visitTree(JCTree tree) {
1527 }
1528
1529 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1530 if (tree != null) {
1531 boolean prevCheckRaw = this.checkRaw;
1532 this.checkRaw = checkRaw;
1533 this.isOuter = isOuter;
1534
1535 try {
1536 tree.accept(this);
1537 if (checkRaw)
1538 checkRaw(tree, env);
1539 } catch (CompletionFailure ex) {
1540 completionError(tree.pos(), ex);
1541 } finally {
1542 this.checkRaw = prevCheckRaw;
1543 }
1544 }
1545 }
1546
1547 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1548 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1549 validateTree(l.head, checkRaw, isOuter);
1550 }
1551 }
1552
1553 void checkRaw(JCTree tree, Env<AttrContext> env) {
1554 if (tree.type.hasTag(CLASS) &&
1555 !TreeInfo.isDiamond(tree) &&
1556 !withinAnonConstr(env) &&
1557 tree.type.isRaw()) {
1558 log.warning(tree.pos(), LintWarnings.RawClassUse(tree.type, tree.type.tsym.type));
1559 }
1560 }
1561 //where
1562 private boolean withinAnonConstr(Env<AttrContext> env) {
1563 return env.enclClass.name.isEmpty() &&
1564 env.enclMethod != null && env.enclMethod.name == names.init;
1565 }
1566
1567 /* *************************************************************************
1568 * Exception checking
1569 **************************************************************************/
1570
1571 /* The following methods treat classes as sets that contain
1572 * the class itself and all their subclasses
1573 */
1574
1575 /** Is given type a subtype of some of the types in given list?
1576 */
1577 boolean subset(Type t, List<Type> ts) {
1578 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1579 if (types.isSubtype(t, l.head)) return true;
1580 return false;
1581 }
1582
1583 /** Is given type a subtype or supertype of
1584 * some of the types in given list?
1585 */
1586 boolean intersects(Type t, List<Type> ts) {
1587 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1588 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1589 return false;
1590 }
1591
1592 /** Add type set to given type list, unless it is a subclass of some class
1593 * in the list.
1594 */
1595 List<Type> incl(Type t, List<Type> ts) {
1596 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1597 }
1598
1599 /** Remove type set from type set list.
1600 */
1601 List<Type> excl(Type t, List<Type> ts) {
1602 if (ts.isEmpty()) {
1603 return ts;
1604 } else {
1605 List<Type> ts1 = excl(t, ts.tail);
1606 if (types.isSubtype(ts.head, t)) return ts1;
1607 else if (ts1 == ts.tail) return ts;
1608 else return ts1.prepend(ts.head);
1609 }
1610 }
1611
1612 /** Form the union of two type set lists.
1613 */
1614 List<Type> union(List<Type> ts1, List<Type> ts2) {
1615 List<Type> ts = ts1;
1616 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1617 ts = incl(l.head, ts);
1618 return ts;
1619 }
1620
1621 /** Form the difference of two type lists.
1622 */
1623 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1624 List<Type> ts = ts1;
1625 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1626 ts = excl(l.head, ts);
1627 return ts;
1628 }
1629
1630 /** Form the intersection of two type lists.
1631 */
1632 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1633 List<Type> ts = List.nil();
1634 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1635 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1636 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1637 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1638 return ts;
1639 }
1640
1641 /** Is exc an exception symbol that need not be declared?
1642 */
1643 boolean isUnchecked(ClassSymbol exc) {
1644 return
1645 exc.kind == ERR ||
1646 exc.isSubClass(syms.errorType.tsym, types) ||
1647 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1648 }
1649
1650 /** Is exc an exception type that need not be declared?
1651 */
1652 boolean isUnchecked(Type exc) {
1653 return
1654 (exc.hasTag(TYPEVAR)) ? isUnchecked(types.supertype(exc)) :
1655 (exc.hasTag(CLASS)) ? isUnchecked((ClassSymbol)exc.tsym) :
1656 exc.hasTag(BOT);
1657 }
1658
1659 boolean isChecked(Type exc) {
1660 return !isUnchecked(exc);
1661 }
1662
1663 /** Same, but handling completion failures.
1664 */
1665 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1666 try {
1667 return isUnchecked(exc);
1668 } catch (CompletionFailure ex) {
1669 completionError(pos, ex);
1670 return true;
1671 }
1672 }
1673
1674 /** Is exc handled by given exception list?
1675 */
1676 boolean isHandled(Type exc, List<Type> handled) {
1677 return isUnchecked(exc) || subset(exc, handled);
1678 }
1679
1680 /** Return all exceptions in thrown list that are not in handled list.
1681 * @param thrown The list of thrown exceptions.
1682 * @param handled The list of handled exceptions.
1683 */
1684 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1685 List<Type> unhandled = List.nil();
1686 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1687 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1688 return unhandled;
1689 }
1690
1691 /* *************************************************************************
1692 * Overriding/Implementation checking
1693 **************************************************************************/
1694
1695 /** The level of access protection given by a flag set,
1696 * where PRIVATE is highest and PUBLIC is lowest.
1697 */
1698 static int protection(long flags) {
1699 switch ((short)(flags & AccessFlags)) {
1700 case PRIVATE: return 3;
1701 case PROTECTED: return 1;
1702 default:
1703 case PUBLIC: return 0;
1704 case 0: return 2;
1705 }
1706 }
1707
1708 /** A customized "cannot override" error message.
1709 * @param m The overriding method.
1710 * @param other The overridden method.
1711 * @return An internationalized string.
1712 */
1713 Fragment cannotOverride(MethodSymbol m, MethodSymbol other) {
1714 Symbol mloc = m.location();
1715 Symbol oloc = other.location();
1716
1717 if ((other.owner.flags() & INTERFACE) == 0)
1718 return Fragments.CantOverride(m, mloc, other, oloc);
1719 else if ((m.owner.flags() & INTERFACE) == 0)
1720 return Fragments.CantImplement(m, mloc, other, oloc);
1721 else
1722 return Fragments.ClashesWith(m, mloc, other, oloc);
1723 }
1724
1725 /** A customized "override" warning message.
1726 * @param m The overriding method.
1727 * @param other The overridden method.
1728 * @return An internationalized string.
1729 */
1730 Fragment uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1731 Symbol mloc = m.location();
1732 Symbol oloc = other.location();
1733
1734 if ((other.owner.flags() & INTERFACE) == 0)
1735 return Fragments.UncheckedOverride(m, mloc, other, oloc);
1736 else if ((m.owner.flags() & INTERFACE) == 0)
1737 return Fragments.UncheckedImplement(m, mloc, other, oloc);
1738 else
1739 return Fragments.UncheckedClashWith(m, mloc, other, oloc);
1740 }
1741
1742 /** A customized "override" warning message.
1743 * @param m The overriding method.
1744 * @param other The overridden method.
1745 * @return An internationalized string.
1746 */
1747 Fragment varargsOverrides(MethodSymbol m, MethodSymbol other) {
1748 Symbol mloc = m.location();
1749 Symbol oloc = other.location();
1750
1751 if ((other.owner.flags() & INTERFACE) == 0)
1752 return Fragments.VarargsOverride(m, mloc, other, oloc);
1753 else if ((m.owner.flags() & INTERFACE) == 0)
1754 return Fragments.VarargsImplement(m, mloc, other, oloc);
1755 else
1756 return Fragments.VarargsClashWith(m, mloc, other, oloc);
1757 }
1758
1759 /** Check that this method conforms with overridden method 'other'.
1760 * where `origin' is the class where checking started.
1761 * Complications:
1762 * (1) Do not check overriding of synthetic methods
1763 * (reason: they might be final).
1764 * todo: check whether this is still necessary.
1765 * (2) Admit the case where an interface proxy throws fewer exceptions
1766 * than the method it implements. Augment the proxy methods with the
1767 * undeclared exceptions in this case.
1768 * (3) When generics are enabled, admit the case where an interface proxy
1769 * has a result type
1770 * extended by the result type of the method it implements.
1771 * Change the proxies result type to the smaller type in this case.
1772 *
1773 * @param tree The tree from which positions
1774 * are extracted for errors.
1775 * @param m The overriding method.
1776 * @param other The overridden method.
1777 * @param origin The class of which the overriding method
1778 * is a member.
1779 */
1780 void checkOverride(JCTree tree,
1781 MethodSymbol m,
1782 MethodSymbol other,
1783 ClassSymbol origin) {
1784 // Don't check overriding of synthetic methods or by bridge methods.
1785 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1786 return;
1787 }
1788
1789 // Error if static method overrides instance method (JLS 8.4.8.2).
1790 if ((m.flags() & STATIC) != 0 &&
1791 (other.flags() & STATIC) == 0) {
1792 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1793 Errors.OverrideStatic(cannotOverride(m, other)));
1794 m.flags_field |= BAD_OVERRIDE;
1795 return;
1796 }
1797
1798 // Error if instance method overrides static or final
1799 // method (JLS 8.4.8.1).
1800 if ((other.flags() & FINAL) != 0 ||
1801 (m.flags() & STATIC) == 0 &&
1802 (other.flags() & STATIC) != 0) {
1803 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1804 Errors.OverrideMeth(cannotOverride(m, other),
1805 asFlagSet(other.flags() & (FINAL | STATIC))));
1806 m.flags_field |= BAD_OVERRIDE;
1807 return;
1808 }
1809
1810 if ((m.owner.flags() & ANNOTATION) != 0) {
1811 // handled in validateAnnotationMethod
1812 return;
1813 }
1814
1815 // Error if overriding method has weaker access (JLS 8.4.8.3).
1816 if (protection(m.flags()) > protection(other.flags())) {
1817 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1818 (other.flags() & AccessFlags) == 0 ?
1819 Errors.OverrideWeakerAccess(cannotOverride(m, other),
1820 "package") :
1821 Errors.OverrideWeakerAccess(cannotOverride(m, other),
1822 asFlagSet(other.flags() & AccessFlags)));
1823 m.flags_field |= BAD_OVERRIDE;
1824 return;
1825 }
1826
1827 if (shouldCheckPreview(m, other, origin)) {
1828 checkPreview(TreeInfo.diagnosticPositionFor(m, tree),
1829 m, origin.type, other);
1830 }
1831
1832 Type mt = types.memberType(origin.type, m);
1833 Type ot = types.memberType(origin.type, other);
1834 // Error if overriding result type is different
1835 // (or, in the case of generics mode, not a subtype) of
1836 // overridden result type. We have to rename any type parameters
1837 // before comparing types.
1838 List<Type> mtvars = mt.getTypeArguments();
1839 List<Type> otvars = ot.getTypeArguments();
1840 Type mtres = mt.getReturnType();
1841 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1842
1843 overrideWarner.clear();
1844 boolean resultTypesOK =
1845 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1846 if (!resultTypesOK) {
1847 if ((m.flags() & STATIC) != 0 && (other.flags() & STATIC) != 0) {
1848 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1849 Errors.OverrideIncompatibleRet(Fragments.CantHide(m, m.location(), other,
1850 other.location()), mtres, otres));
1851 m.flags_field |= BAD_OVERRIDE;
1852 } else {
1853 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1854 Errors.OverrideIncompatibleRet(cannotOverride(m, other), mtres, otres));
1855 m.flags_field |= BAD_OVERRIDE;
1856 }
1857 return;
1858 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1859 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1860 LintWarnings.OverrideUncheckedRet(uncheckedOverrides(m, other), mtres, otres));
1861 }
1862
1863 // Error if overriding method throws an exception not reported
1864 // by overridden method.
1865 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1866 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1867 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1868 if (unhandledErased.nonEmpty()) {
1869 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1870 Errors.OverrideMethDoesntThrow(cannotOverride(m, other), unhandledUnerased.head));
1871 m.flags_field |= BAD_OVERRIDE;
1872 return;
1873 }
1874 else if (unhandledUnerased.nonEmpty()) {
1875 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1876 LintWarnings.OverrideUncheckedThrown(cannotOverride(m, other), unhandledUnerased.head));
1877 return;
1878 }
1879
1880 // Optional warning if varargs don't agree
1881 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)) {
1882 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1883 ((m.flags() & Flags.VARARGS) != 0)
1884 ? LintWarnings.OverrideVarargsMissing(varargsOverrides(m, other))
1885 : LintWarnings.OverrideVarargsExtra(varargsOverrides(m, other)));
1886 }
1887
1888 // Warn if instance method overrides bridge method (compiler spec ??)
1889 if ((other.flags() & BRIDGE) != 0) {
1890 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1891 Warnings.OverrideBridge(uncheckedOverrides(m, other)));
1892 }
1893
1894 // Warn if a deprecated method overridden by a non-deprecated one.
1895 if (!isDeprecatedOverrideIgnorable(other, origin)) {
1896 checkDeprecated(() -> TreeInfo.diagnosticPositionFor(m, tree), m, other);
1897 }
1898 }
1899 // where
1900 private boolean shouldCheckPreview(MethodSymbol m, MethodSymbol other, ClassSymbol origin) {
1901 if (m.owner != origin ||
1902 //performance - only do the expensive checks when the overridden method is a Preview API:
1903 ((other.flags() & PREVIEW_API) == 0 &&
1904 (other.owner.flags() & PREVIEW_API) == 0)) {
1905 return false;
1906 }
1907
1908 for (Symbol s : types.membersClosure(origin.type, false).getSymbolsByName(m.name)) {
1909 if (m != s && m.overrides(s, origin, types, false)) {
1910 //only produce preview warnings or errors if "m" immediatelly overrides "other"
1911 //without intermediate overriding methods:
1912 return s == other;
1913 }
1914 }
1915
1916 return false;
1917 }
1918 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1919 // If the method, m, is defined in an interface, then ignore the issue if the method
1920 // is only inherited via a supertype and also implemented in the supertype,
1921 // because in that case, we will rediscover the issue when examining the method
1922 // in the supertype.
1923 // If the method, m, is not defined in an interface, then the only time we need to
1924 // address the issue is when the method is the supertype implementation: any other
1925 // case, we will have dealt with when examining the supertype classes
1926 ClassSymbol mc = m.enclClass();
1927 Type st = types.supertype(origin.type);
1928 if (!st.hasTag(CLASS))
1929 return true;
1930 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1931
1932 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1933 List<Type> intfs = types.interfaces(origin.type);
1934 return (intfs.contains(mc.type) ? false : (stimpl != null));
1935 }
1936 else
1937 return (stimpl != m);
1938 }
1939
1940
1941 // used to check if there were any unchecked conversions
1942 Warner overrideWarner = new Warner();
1943
1944 /** Check that a class does not inherit two concrete methods
1945 * with the same signature.
1946 * @param pos Position to be used for error reporting.
1947 * @param site The class type to be checked.
1948 */
1949 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1950 Type sup = types.supertype(site);
1951 if (!sup.hasTag(CLASS)) return;
1952
1953 for (Type t1 = sup;
1954 t1.hasTag(CLASS) && t1.tsym.type.isParameterized();
1955 t1 = types.supertype(t1)) {
1956 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) {
1957 if (s1.kind != MTH ||
1958 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1959 !s1.isInheritedIn(site.tsym, types) ||
1960 ((MethodSymbol)s1).implementation(site.tsym,
1961 types,
1962 true) != s1)
1963 continue;
1964 Type st1 = types.memberType(t1, s1);
1965 int s1ArgsLength = st1.getParameterTypes().length();
1966 if (st1 == s1.type) continue;
1967
1968 for (Type t2 = sup;
1969 t2.hasTag(CLASS);
1970 t2 = types.supertype(t2)) {
1971 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) {
1972 if (s2 == s1 ||
1973 s2.kind != MTH ||
1974 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1975 s2.type.getParameterTypes().length() != s1ArgsLength ||
1976 !s2.isInheritedIn(site.tsym, types) ||
1977 ((MethodSymbol)s2).implementation(site.tsym,
1978 types,
1979 true) != s2)
1980 continue;
1981 Type st2 = types.memberType(t2, s2);
1982 if (types.overrideEquivalent(st1, st2))
1983 log.error(pos,
1984 Errors.ConcreteInheritanceConflict(s1, t1, s2, t2, sup));
1985 }
1986 }
1987 }
1988 }
1989 }
1990
1991 /** Check that classes (or interfaces) do not each define an abstract
1992 * method with same name and arguments but incompatible return types.
1993 * @param pos Position to be used for error reporting.
1994 * @param t1 The first argument type.
1995 * @param t2 The second argument type.
1996 */
1997 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1998 Type t1,
1999 Type t2,
2000 Type site) {
2001 if ((site.tsym.flags() & COMPOUND) != 0) {
2002 // special case for intersections: need to eliminate wildcards in supertypes
2003 t1 = types.capture(t1);
2004 t2 = types.capture(t2);
2005 }
2006 return firstIncompatibility(pos, t1, t2, site) == null;
2007 }
2008
2009 /** Return the first method which is defined with same args
2010 * but different return types in two given interfaces, or null if none
2011 * exists.
2012 * @param t1 The first type.
2013 * @param t2 The second type.
2014 * @param site The most derived type.
2015 * @return symbol from t2 that conflicts with one in t1.
2016 */
2017 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
2018 Map<TypeSymbol,Type> interfaces1 = new HashMap<>();
2019 closure(t1, interfaces1);
2020 Map<TypeSymbol,Type> interfaces2;
2021 if (t1 == t2)
2022 interfaces2 = interfaces1;
2023 else
2024 closure(t2, interfaces1, interfaces2 = new HashMap<>());
2025
2026 for (Type t3 : interfaces1.values()) {
2027 for (Type t4 : interfaces2.values()) {
2028 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
2029 if (s != null) return s;
2030 }
2031 }
2032 return null;
2033 }
2034
2035 /** Compute all the supertypes of t, indexed by type symbol. */
2036 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
2037 if (!t.hasTag(CLASS)) return;
2038 if (typeMap.put(t.tsym, t) == null) {
2039 closure(types.supertype(t), typeMap);
2040 for (Type i : types.interfaces(t))
2041 closure(i, typeMap);
2042 }
2043 }
2044
2045 /** Compute all the supertypes of t, indexed by type symbol (except those in typesSkip). */
2046 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
2047 if (!t.hasTag(CLASS)) return;
2048 if (typesSkip.get(t.tsym) != null) return;
2049 if (typeMap.put(t.tsym, t) == null) {
2050 closure(types.supertype(t), typesSkip, typeMap);
2051 for (Type i : types.interfaces(t))
2052 closure(i, typesSkip, typeMap);
2053 }
2054 }
2055
2056 /** Return the first method in t2 that conflicts with a method from t1. */
2057 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
2058 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) {
2059 Type st1 = null;
2060 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types) ||
2061 (s1.flags() & SYNTHETIC) != 0) continue;
2062 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
2063 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
2064 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) {
2065 if (s1 == s2) continue;
2066 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types) ||
2067 (s2.flags() & SYNTHETIC) != 0) continue;
2068 if (st1 == null) st1 = types.memberType(t1, s1);
2069 Type st2 = types.memberType(t2, s2);
2070 if (types.overrideEquivalent(st1, st2)) {
2071 List<Type> tvars1 = st1.getTypeArguments();
2072 List<Type> tvars2 = st2.getTypeArguments();
2073 Type rt1 = st1.getReturnType();
2074 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
2075 boolean compat =
2076 types.isSameType(rt1, rt2) ||
2077 !rt1.isPrimitiveOrVoid() &&
2078 !rt2.isPrimitiveOrVoid() &&
2079 (types.covariantReturnType(rt1, rt2, types.noWarnings) ||
2080 types.covariantReturnType(rt2, rt1, types.noWarnings)) ||
2081 checkCommonOverriderIn(s1,s2,site);
2082 if (!compat) {
2083 if (types.isSameType(t1, t2)) {
2084 log.error(pos, Errors.IncompatibleDiffRetSameType(t1,
2085 s2.name, types.memberType(t2, s2).getParameterTypes()));
2086 } else {
2087 log.error(pos, Errors.TypesIncompatible(t1, t2,
2088 Fragments.IncompatibleDiffRet(s2.name, types.memberType(t2, s2).getParameterTypes())));
2089 }
2090 return s2;
2091 }
2092 } else if (checkNameClash((ClassSymbol)site.tsym, s1, s2) &&
2093 !checkCommonOverriderIn(s1, s2, site)) {
2094 log.error(pos, Errors.NameClashSameErasureNoOverride(
2095 s1.name, types.memberType(site, s1).asMethodType().getParameterTypes(), s1.location(),
2096 s2.name, types.memberType(site, s2).asMethodType().getParameterTypes(), s2.location()));
2097 return s2;
2098 }
2099 }
2100 }
2101 return null;
2102 }
2103 //WHERE
2104 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
2105 Map<TypeSymbol,Type> supertypes = new HashMap<>();
2106 Type st1 = types.memberType(site, s1);
2107 Type st2 = types.memberType(site, s2);
2108 closure(site, supertypes);
2109 for (Type t : supertypes.values()) {
2110 for (Symbol s3 : t.tsym.members().getSymbolsByName(s1.name)) {
2111 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
2112 Type st3 = types.memberType(site,s3);
2113 if (types.overrideEquivalent(st3, st1) &&
2114 types.overrideEquivalent(st3, st2) &&
2115 types.returnTypeSubstitutable(st3, st1) &&
2116 types.returnTypeSubstitutable(st3, st2)) {
2117 return true;
2118 }
2119 }
2120 }
2121 return false;
2122 }
2123
2124 /** Check that a given method conforms with any method it overrides.
2125 * @param tree The tree from which positions are extracted
2126 * for errors.
2127 * @param m The overriding method.
2128 */
2129 void checkOverride(Env<AttrContext> env, JCMethodDecl tree, MethodSymbol m) {
2130 ClassSymbol origin = (ClassSymbol)m.owner;
2131 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name)) {
2132 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
2133 log.error(tree.pos(), Errors.EnumNoFinalize);
2134 return;
2135 }
2136 }
2137 if (allowValueClasses && origin.isValueClass() && names.finalize.equals(m.name)) {
2138 if (m.overrides(syms.objectFinalize, origin, types, false)) {
2139 log.warning(tree.pos(), Warnings.ValueFinalize);
2140 }
2141 }
2142 if (allowRecords && origin.isRecord()) {
2143 // let's find out if this is a user defined accessor in which case the @Override annotation is acceptable
2144 Optional<? extends RecordComponent> recordComponent = origin.getRecordComponents().stream()
2145 .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
2146 if (recordComponent.isPresent()) {
2147 return;
2148 }
2149 }
2150
2151 for (Type t = origin.type; t.hasTag(CLASS);
2152 t = types.supertype(t)) {
2153 if (t != origin.type) {
2154 checkOverride(tree, t, origin, m);
2155 }
2156 for (Type t2 : types.interfaces(t)) {
2157 checkOverride(tree, t2, origin, m);
2158 }
2159 }
2160
2161 final boolean explicitOverride = m.attribute(syms.overrideType.tsym) != null;
2162 // Check if this method must override a super method due to being annotated with @Override
2163 // or by virtue of being a member of a diamond inferred anonymous class. Latter case is to
2164 // be treated "as if as they were annotated" with @Override.
2165 boolean mustOverride = explicitOverride ||
2166 (env.info.isAnonymousDiamond && !m.isConstructor() && !m.isPrivate());
2167 if (mustOverride && !isOverrider(m)) {
2168 DiagnosticPosition pos = tree.pos();
2169 for (JCAnnotation a : tree.getModifiers().annotations) {
2170 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2171 pos = a.pos();
2172 break;
2173 }
2174 }
2175 log.error(pos,
2176 explicitOverride ? (m.isStatic() ? Errors.StaticMethodsCannotBeAnnotatedWithOverride : Errors.MethodDoesNotOverrideSuperclass) :
2177 Errors.AnonymousDiamondMethodDoesNotOverrideSuperclass(Fragments.DiamondAnonymousMethodsImplicitlyOverride));
2178 }
2179 }
2180
2181 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
2182 TypeSymbol c = site.tsym;
2183 for (Symbol sym : c.members().getSymbolsByName(m.name)) {
2184 if (m.overrides(sym, origin, types, false)) {
2185 if ((sym.flags() & ABSTRACT) == 0) {
2186 checkOverride(tree, m, (MethodSymbol)sym, origin);
2187 }
2188 }
2189 }
2190 }
2191
2192 private Predicate<Symbol> equalsHasCodeFilter = s -> MethodSymbol.implementation_filter.test(s) &&
2193 (s.flags() & BAD_OVERRIDE) == 0;
2194
2195 public void checkClassOverrideEqualsAndHashIfNeeded(DiagnosticPosition pos,
2196 ClassSymbol someClass) {
2197 /* At present, annotations cannot possibly have a method that is override
2198 * equivalent with Object.equals(Object) but in any case the condition is
2199 * fine for completeness.
2200 */
2201 if (someClass == (ClassSymbol)syms.objectType.tsym ||
2202 someClass.isInterface() || someClass.isEnum() ||
2203 (someClass.flags() & ANNOTATION) != 0 ||
2204 (someClass.flags() & ABSTRACT) != 0) return;
2205 //anonymous inner classes implementing interfaces need especial treatment
2206 if (someClass.isAnonymous()) {
2207 List<Type> interfaces = types.interfaces(someClass.type);
2208 if (interfaces != null && !interfaces.isEmpty() &&
2209 interfaces.head.tsym == syms.comparatorType.tsym) return;
2210 }
2211 checkClassOverrideEqualsAndHash(pos, someClass);
2212 }
2213
2214 private void checkClassOverrideEqualsAndHash(DiagnosticPosition pos,
2215 ClassSymbol someClass) {
2216 if (lint.isEnabled(LintCategory.OVERRIDES)) {
2217 MethodSymbol equalsAtObject = (MethodSymbol)syms.objectType
2218 .tsym.members().findFirst(names.equals);
2219 MethodSymbol hashCodeAtObject = (MethodSymbol)syms.objectType
2220 .tsym.members().findFirst(names.hashCode);
2221 MethodSymbol equalsImpl = types.implementation(equalsAtObject,
2222 someClass, false, equalsHasCodeFilter);
2223 boolean overridesEquals = equalsImpl != null &&
2224 equalsImpl.owner == someClass;
2225 boolean overridesHashCode = types.implementation(hashCodeAtObject,
2226 someClass, false, equalsHasCodeFilter) != hashCodeAtObject;
2227
2228 if (overridesEquals && !overridesHashCode) {
2229 log.warning(pos,
2230 LintWarnings.OverrideEqualsButNotHashcode(someClass));
2231 }
2232 }
2233 }
2234
2235 public void checkHasMain(DiagnosticPosition pos, ClassSymbol c) {
2236 boolean found = false;
2237
2238 for (Symbol sym : c.members().getSymbolsByName(names.main)) {
2239 if (sym.kind == MTH && (sym.flags() & PRIVATE) == 0) {
2240 MethodSymbol meth = (MethodSymbol)sym;
2241 if (!types.isSameType(meth.getReturnType(), syms.voidType)) {
2242 continue;
2243 }
2244 if (meth.params.isEmpty()) {
2245 found = true;
2246 break;
2247 }
2248 if (meth.params.size() != 1) {
2249 continue;
2250 }
2251 if (!types.isSameType(meth.params.head.type, types.makeArrayType(syms.stringType))) {
2252 continue;
2253 }
2254
2255 found = true;
2256 break;
2257 }
2258 }
2259
2260 if (!found) {
2261 log.error(pos, Errors.ImplicitClassDoesNotHaveMainMethod);
2262 }
2263 }
2264
2265 public void checkModuleName (JCModuleDecl tree) {
2266 Name moduleName = tree.sym.name;
2267 Assert.checkNonNull(moduleName);
2268 if (lint.isEnabled(LintCategory.MODULE)) {
2269 JCExpression qualId = tree.qualId;
2270 while (qualId != null) {
2271 Name componentName;
2272 DiagnosticPosition pos;
2273 switch (qualId.getTag()) {
2274 case SELECT:
2275 JCFieldAccess selectNode = ((JCFieldAccess) qualId);
2276 componentName = selectNode.name;
2277 pos = selectNode.pos();
2278 qualId = selectNode.selected;
2279 break;
2280 case IDENT:
2281 componentName = ((JCIdent) qualId).name;
2282 pos = qualId.pos();
2283 qualId = null;
2284 break;
2285 default:
2286 throw new AssertionError("Unexpected qualified identifier: " + qualId.toString());
2287 }
2288 if (componentName != null) {
2289 String moduleNameComponentString = componentName.toString();
2290 int nameLength = moduleNameComponentString.length();
2291 if (nameLength > 0 && Character.isDigit(moduleNameComponentString.charAt(nameLength - 1))) {
2292 log.warning(pos, LintWarnings.PoorChoiceForModuleName(componentName));
2293 }
2294 }
2295 }
2296 }
2297 }
2298
2299 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
2300 ClashFilter cf = new ClashFilter(origin.type);
2301 return (cf.test(s1) &&
2302 cf.test(s2) &&
2303 types.hasSameArgs(s1.erasure(types), s2.erasure(types)));
2304 }
2305
2306
2307 /** Check that all abstract members of given class have definitions.
2308 * @param pos Position to be used for error reporting.
2309 * @param c The class.
2310 */
2311 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
2312 MethodSymbol undef = types.firstUnimplementedAbstract(c);
2313 if (undef != null) {
2314 MethodSymbol undef1 =
2315 new MethodSymbol(undef.flags(), undef.name,
2316 types.memberType(c.type, undef), undef.owner);
2317 log.error(pos,
2318 Errors.DoesNotOverrideAbstract(c, undef1, undef1.location()));
2319 }
2320 }
2321
2322 void checkNonCyclicDecl(JCClassDecl tree) {
2323 CycleChecker cc = new CycleChecker();
2324 cc.scan(tree);
2325 if (!cc.errorFound && !cc.partialCheck) {
2326 tree.sym.flags_field |= ACYCLIC;
2327 }
2328 }
2329
2330 class CycleChecker extends TreeScanner {
2331
2332 Set<Symbol> seenClasses = new HashSet<>();
2333 boolean errorFound = false;
2334 boolean partialCheck = false;
2335
2336 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
2337 if (sym != null && sym.kind == TYP) {
2338 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
2339 if (classEnv != null) {
2340 DiagnosticSource prevSource = log.currentSource();
2341 try {
2342 log.useSource(classEnv.toplevel.sourcefile);
2343 scan(classEnv.tree);
2344 }
2345 finally {
2346 log.useSource(prevSource.getFile());
2347 }
2348 } else if (sym.kind == TYP) {
2349 checkClass(pos, sym, List.nil());
2350 }
2351 } else if (sym == null || sym.kind != PCK) {
2352 //not completed yet
2353 partialCheck = true;
2354 }
2355 }
2356
2357 @Override
2358 public void visitSelect(JCFieldAccess tree) {
2359 super.visitSelect(tree);
2360 checkSymbol(tree.pos(), tree.sym);
2361 }
2362
2363 @Override
2364 public void visitIdent(JCIdent tree) {
2365 checkSymbol(tree.pos(), tree.sym);
2366 }
2367
2368 @Override
2369 public void visitTypeApply(JCTypeApply tree) {
2370 scan(tree.clazz);
2371 }
2372
2373 @Override
2374 public void visitTypeArray(JCArrayTypeTree tree) {
2375 scan(tree.elemtype);
2376 }
2377
2378 @Override
2379 public void visitClassDef(JCClassDecl tree) {
2380 List<JCTree> supertypes = List.nil();
2381 if (tree.getExtendsClause() != null) {
2382 supertypes = supertypes.prepend(tree.getExtendsClause());
2383 }
2384 if (tree.getImplementsClause() != null) {
2385 for (JCTree intf : tree.getImplementsClause()) {
2386 supertypes = supertypes.prepend(intf);
2387 }
2388 }
2389 checkClass(tree.pos(), tree.sym, supertypes);
2390 }
2391
2392 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
2393 if ((c.flags_field & ACYCLIC) != 0)
2394 return;
2395 if (seenClasses.contains(c)) {
2396 errorFound = true;
2397 log.error(pos, Errors.CyclicInheritance(c));
2398 seenClasses.stream()
2399 .filter(s -> !s.type.isErroneous())
2400 .filter(ClassSymbol.class::isInstance)
2401 .map(ClassSymbol.class::cast)
2402 .forEach(Check.this::handleCyclic);
2403 } else if (!c.type.isErroneous()) {
2404 try {
2405 seenClasses.add(c);
2406 if (c.type.hasTag(CLASS)) {
2407 if (supertypes.nonEmpty()) {
2408 scan(supertypes);
2409 }
2410 else {
2411 ClassType ct = (ClassType)c.type;
2412 if (ct.supertype_field == null ||
2413 ct.interfaces_field == null) {
2414 //not completed yet
2415 partialCheck = true;
2416 return;
2417 }
2418 checkSymbol(pos, ct.supertype_field.tsym);
2419 for (Type intf : ct.interfaces_field) {
2420 checkSymbol(pos, intf.tsym);
2421 }
2422 }
2423 if (c.owner.kind == TYP) {
2424 checkSymbol(pos, c.owner);
2425 }
2426 }
2427 } finally {
2428 seenClasses.remove(c);
2429 }
2430 }
2431 }
2432 }
2433
2434 /** Check for cyclic references. Issue an error if the
2435 * symbol of the type referred to has a LOCKED flag set.
2436 *
2437 * @param pos Position to be used for error reporting.
2438 * @param t The type referred to.
2439 */
2440 void checkNonCyclic(DiagnosticPosition pos, Type t) {
2441 checkNonCyclicInternal(pos, t);
2442 }
2443
2444
2445 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
2446 checkNonCyclic1(pos, t, List.nil());
2447 }
2448
2449 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
2450 final TypeVar tv;
2451 if (t.hasTag(TYPEVAR) && (t.tsym.flags() & UNATTRIBUTED) != 0)
2452 return;
2453 if (seen.contains(t)) {
2454 tv = (TypeVar)t;
2455 tv.setUpperBound(types.createErrorType(t));
2456 log.error(pos, Errors.CyclicInheritance(t));
2457 } else if (t.hasTag(TYPEVAR)) {
2458 tv = (TypeVar)t;
2459 seen = seen.prepend(tv);
2460 for (Type b : types.getBounds(tv))
2461 checkNonCyclic1(pos, b, seen);
2462 }
2463 }
2464
2465 /** Check for cyclic references. Issue an error if the
2466 * symbol of the type referred to has a LOCKED flag set.
2467 *
2468 * @param pos Position to be used for error reporting.
2469 * @param t The type referred to.
2470 * @return True if the check completed on all attributed classes
2471 */
2472 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
2473 boolean complete = true; // was the check complete?
2474 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
2475 Symbol c = t.tsym;
2476 if ((c.flags_field & ACYCLIC) != 0) return true;
2477
2478 if ((c.flags_field & LOCKED) != 0) {
2479 log.error(pos, Errors.CyclicInheritance(c));
2480 handleCyclic((ClassSymbol)c);
2481 } else if (!c.type.isErroneous()) {
2482 try {
2483 c.flags_field |= LOCKED;
2484 if (c.type.hasTag(CLASS)) {
2485 ClassType clazz = (ClassType)c.type;
2486 if (clazz.interfaces_field != null)
2487 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
2488 complete &= checkNonCyclicInternal(pos, l.head);
2489 if (clazz.supertype_field != null) {
2490 Type st = clazz.supertype_field;
2491 if (st != null && st.hasTag(CLASS))
2492 complete &= checkNonCyclicInternal(pos, st);
2493 }
2494 if (c.owner.kind == TYP)
2495 complete &= checkNonCyclicInternal(pos, c.owner.type);
2496 }
2497 } finally {
2498 c.flags_field &= ~LOCKED;
2499 }
2500 }
2501 if (complete)
2502 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.isCompleted();
2503 if (complete) c.flags_field |= ACYCLIC;
2504 return complete;
2505 }
2506
2507 /** Handle finding an inheritance cycle on a class by setting
2508 * the class' and its supertypes' types to the error type.
2509 **/
2510 private void handleCyclic(ClassSymbol c) {
2511 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
2512 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
2513 Type st = types.supertype(c.type);
2514 if (st.hasTag(CLASS))
2515 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2516 c.type = types.createErrorType(c, c.type);
2517 c.flags_field |= ACYCLIC;
2518 }
2519
2520 /** Check that all methods which implement some
2521 * method conform to the method they implement.
2522 * @param tree The class definition whose members are checked.
2523 */
2524 void checkImplementations(JCClassDecl tree) {
2525 checkImplementations(tree, tree.sym, tree.sym);
2526 }
2527 //where
2528 /** Check that all methods which implement some
2529 * method in `ic' conform to the method they implement.
2530 */
2531 void checkImplementations(JCTree tree, ClassSymbol origin, ClassSymbol ic) {
2532 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2533 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2534 if ((lc.flags() & ABSTRACT) != 0) {
2535 for (Symbol sym : lc.members().getSymbols(NON_RECURSIVE)) {
2536 if (sym.kind == MTH &&
2537 (sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2538 MethodSymbol absmeth = (MethodSymbol)sym;
2539 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2540 if (implmeth != null && implmeth != absmeth &&
2541 (implmeth.owner.flags() & INTERFACE) ==
2542 (origin.flags() & INTERFACE)) {
2543 // don't check if implmeth is in a class, yet
2544 // origin is an interface. This case arises only
2545 // if implmeth is declared in Object. The reason is
2546 // that interfaces really don't inherit from
2547 // Object it's just that the compiler represents
2548 // things that way.
2549 checkOverride(tree, implmeth, absmeth, origin);
2550 }
2551 }
2552 }
2553 }
2554 }
2555 }
2556
2557 /** Check that all abstract methods implemented by a class are
2558 * mutually compatible.
2559 * @param pos Position to be used for error reporting.
2560 * @param c The class whose interfaces are checked.
2561 */
2562 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2563 List<Type> supertypes = types.interfaces(c);
2564 Type supertype = types.supertype(c);
2565 if (supertype.hasTag(CLASS) &&
2566 (supertype.tsym.flags() & ABSTRACT) != 0)
2567 supertypes = supertypes.prepend(supertype);
2568 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2569 if (!l.head.getTypeArguments().isEmpty() &&
2570 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2571 return;
2572 for (List<Type> m = supertypes; m != l; m = m.tail)
2573 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2574 return;
2575 }
2576 checkCompatibleConcretes(pos, c);
2577
2578 Type identitySuper = null;
2579 for (Type t : types.closure(c)) {
2580 if (t != c) {
2581 if (t.isIdentityClass() && (t.tsym.flags() & VALUE_BASED) == 0)
2582 identitySuper = t;
2583 if (c.isValueClass() && identitySuper != null && identitySuper.tsym != syms.objectType.tsym) { // Object is special
2584 log.error(pos, Errors.ValueTypeHasIdentitySuperType(c, identitySuper));
2585 break;
2586 }
2587 }
2588 }
2589 }
2590
2591 /** Check that all non-override equivalent methods accessible from 'site'
2592 * are mutually compatible (JLS 8.4.8/9.4.1).
2593 *
2594 * @param pos Position to be used for error reporting.
2595 * @param site The class whose methods are checked.
2596 * @param sym The method symbol to be checked.
2597 */
2598 void checkOverrideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2599 ClashFilter cf = new ClashFilter(site);
2600 //for each method m1 that is overridden (directly or indirectly)
2601 //by method 'sym' in 'site'...
2602
2603 ArrayList<Symbol> symbolsByName = new ArrayList<>();
2604 types.membersClosure(site, false).getSymbolsByName(sym.name, cf).forEach(symbolsByName::add);
2605 for (Symbol m1 : symbolsByName) {
2606 if (!sym.overrides(m1, site.tsym, types, false)) {
2607 continue;
2608 }
2609
2610 //...check each method m2 that is a member of 'site'
2611 for (Symbol m2 : symbolsByName) {
2612 if (m2 == m1) continue;
2613 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2614 //a member of 'site') and (ii) m1 has the same erasure as m2, issue an error
2615 if (!types.isSubSignature(sym.type, types.memberType(site, m2)) &&
2616 types.hasSameArgs(m2.erasure(types), m1.erasure(types))) {
2617 sym.flags_field |= CLASH;
2618 if (m1 == sym) {
2619 log.error(pos, Errors.NameClashSameErasureNoOverride(
2620 m1.name, types.memberType(site, m1).asMethodType().getParameterTypes(), m1.location(),
2621 m2.name, types.memberType(site, m2).asMethodType().getParameterTypes(), m2.location()));
2622 } else {
2623 ClassType ct = (ClassType)site;
2624 String kind = ct.isInterface() ? "interface" : "class";
2625 log.error(pos, Errors.NameClashSameErasureNoOverride1(
2626 kind,
2627 ct.tsym.name,
2628 m1.name,
2629 types.memberType(site, m1).asMethodType().getParameterTypes(),
2630 m1.location(),
2631 m2.name,
2632 types.memberType(site, m2).asMethodType().getParameterTypes(),
2633 m2.location()));
2634 }
2635 return;
2636 }
2637 }
2638 }
2639 }
2640
2641 /** Check that all static methods accessible from 'site' are
2642 * mutually compatible (JLS 8.4.8).
2643 *
2644 * @param pos Position to be used for error reporting.
2645 * @param site The class whose methods are checked.
2646 * @param sym The method symbol to be checked.
2647 */
2648 void checkHideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2649 ClashFilter cf = new ClashFilter(site);
2650 //for each method m1 that is a member of 'site'...
2651 for (Symbol s : types.membersClosure(site, true).getSymbolsByName(sym.name, cf)) {
2652 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2653 //a member of 'site') and (ii) 'sym' has the same erasure as m1, issue an error
2654 if (!types.isSubSignature(sym.type, types.memberType(site, s))) {
2655 if (types.hasSameArgs(s.erasure(types), sym.erasure(types))) {
2656 log.error(pos,
2657 Errors.NameClashSameErasureNoHide(sym, sym.location(), s, s.location()));
2658 return;
2659 }
2660 }
2661 }
2662 }
2663
2664 //where
2665 private class ClashFilter implements Predicate<Symbol> {
2666
2667 Type site;
2668
2669 ClashFilter(Type site) {
2670 this.site = site;
2671 }
2672
2673 boolean shouldSkip(Symbol s) {
2674 return (s.flags() & CLASH) != 0 &&
2675 s.owner == site.tsym;
2676 }
2677
2678 @Override
2679 public boolean test(Symbol s) {
2680 return s.kind == MTH &&
2681 (s.flags() & SYNTHETIC) == 0 &&
2682 !shouldSkip(s) &&
2683 s.isInheritedIn(site.tsym, types) &&
2684 !s.isConstructor();
2685 }
2686 }
2687
2688 void checkDefaultMethodClashes(DiagnosticPosition pos, Type site) {
2689 DefaultMethodClashFilter dcf = new DefaultMethodClashFilter(site);
2690 for (Symbol m : types.membersClosure(site, false).getSymbols(dcf)) {
2691 Assert.check(m.kind == MTH);
2692 List<MethodSymbol> prov = types.interfaceCandidates(site, (MethodSymbol)m);
2693 if (prov.size() > 1) {
2694 ListBuffer<Symbol> abstracts = new ListBuffer<>();
2695 ListBuffer<Symbol> defaults = new ListBuffer<>();
2696 for (MethodSymbol provSym : prov) {
2697 if ((provSym.flags() & DEFAULT) != 0) {
2698 defaults = defaults.append(provSym);
2699 } else if ((provSym.flags() & ABSTRACT) != 0) {
2700 abstracts = abstracts.append(provSym);
2701 }
2702 if (defaults.nonEmpty() && defaults.size() + abstracts.size() >= 2) {
2703 //strong semantics - issue an error if two sibling interfaces
2704 //have two override-equivalent defaults - or if one is abstract
2705 //and the other is default
2706 Fragment diagKey;
2707 Symbol s1 = defaults.first();
2708 Symbol s2;
2709 if (defaults.size() > 1) {
2710 s2 = defaults.toList().tail.head;
2711 diagKey = Fragments.IncompatibleUnrelatedDefaults(Kinds.kindName(site.tsym), site,
2712 m.name, types.memberType(site, m).getParameterTypes(),
2713 s1.location(), s2.location());
2714
2715 } else {
2716 s2 = abstracts.first();
2717 diagKey = Fragments.IncompatibleAbstractDefault(Kinds.kindName(site.tsym), site,
2718 m.name, types.memberType(site, m).getParameterTypes(),
2719 s1.location(), s2.location());
2720 }
2721 log.error(pos, Errors.TypesIncompatible(s1.location().type, s2.location().type, diagKey));
2722 break;
2723 }
2724 }
2725 }
2726 }
2727 }
2728
2729 //where
2730 private class DefaultMethodClashFilter implements Predicate<Symbol> {
2731
2732 Type site;
2733
2734 DefaultMethodClashFilter(Type site) {
2735 this.site = site;
2736 }
2737
2738 @Override
2739 public boolean test(Symbol s) {
2740 return s.kind == MTH &&
2741 (s.flags() & DEFAULT) != 0 &&
2742 s.isInheritedIn(site.tsym, types) &&
2743 !s.isConstructor();
2744 }
2745 }
2746
2747 /** Report warnings for potentially ambiguous method declarations in the given site. */
2748 void checkPotentiallyAmbiguousOverloads(JCClassDecl tree, Type site) {
2749
2750 // Skip if warning not enabled
2751 if (!lint.isEnabled(LintCategory.OVERLOADS))
2752 return;
2753
2754 // Gather all of site's methods, including overridden methods, grouped by name (except Object methods)
2755 List<java.util.List<MethodSymbol>> methodGroups = methodsGroupedByName(site,
2756 new PotentiallyAmbiguousFilter(site), ArrayList::new);
2757
2758 // Build the predicate that determines if site is responsible for an ambiguity
2759 BiPredicate<MethodSymbol, MethodSymbol> responsible = buildResponsiblePredicate(site, methodGroups);
2760
2761 // Now remove overridden methods from each group, leaving only site's actual members
2762 methodGroups.forEach(list -> removePreempted(list, (m1, m2) -> m1.overrides(m2, site.tsym, types, false)));
2763
2764 // Allow site's own declared methods (only) to apply @SuppressWarnings("overloads")
2765 methodGroups.forEach(list -> list.removeIf(
2766 m -> m.owner == site.tsym && !lint.augment(m).isEnabled(LintCategory.OVERLOADS)));
2767
2768 // Warn about ambiguous overload method pairs for which site is responsible
2769 methodGroups.forEach(list -> compareAndRemove(list, (m1, m2) -> {
2770
2771 // See if this is an ambiguous overload for which "site" is responsible
2772 if (!potentiallyAmbiguousOverload(site, m1, m2) || !responsible.test(m1, m2))
2773 return 0;
2774
2775 // Locate the warning at one of the methods, if possible
2776 DiagnosticPosition pos =
2777 m1.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m1, tree) :
2778 m2.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m2, tree) :
2779 tree.pos();
2780
2781 // Log the warning
2782 log.warning(pos,
2783 LintWarnings.PotentiallyAmbiguousOverload(
2784 m1.asMemberOf(site, types), m1.location(),
2785 m2.asMemberOf(site, types), m2.location()));
2786
2787 // Don't warn again for either of these two methods
2788 return FIRST | SECOND;
2789 }));
2790 }
2791
2792 /** Build a predicate that determines, given two methods that are members of the given class,
2793 * whether the class should be held "responsible" if the methods are potentially ambiguous.
2794 *
2795 * Sometimes ambiguous methods are unavoidable because they're inherited from a supertype.
2796 * For example, any subtype of Spliterator.OfInt will have ambiguities for both
2797 * forEachRemaining() and tryAdvance() (in both cases the overloads are IntConsumer and
2798 * Consumer<? super Integer>). So we only want to "blame" a class when that class is
2799 * itself responsible for creating the ambiguity. We declare that a class C is "responsible"
2800 * for the ambiguity between two methods m1 and m2 if there is no direct supertype T of C
2801 * such that m1 and m2, or some overrides thereof, both exist in T and are ambiguous in T.
2802 * As an optimization, we first check if either method is declared in C and does not override
2803 * any other methods; in this case the class is definitely responsible.
2804 */
2805 BiPredicate<MethodSymbol, MethodSymbol> buildResponsiblePredicate(Type site,
2806 List<? extends Collection<MethodSymbol>> methodGroups) {
2807
2808 // Define the "overrides" predicate
2809 BiPredicate<MethodSymbol, MethodSymbol> overrides = (m1, m2) -> m1.overrides(m2, site.tsym, types, false);
2810
2811 // Map each method declared in site to a list of the supertype method(s) it directly overrides
2812 HashMap<MethodSymbol, ArrayList<MethodSymbol>> overriddenMethodsMap = new HashMap<>();
2813 methodGroups.forEach(list -> {
2814 for (MethodSymbol m : list) {
2815
2816 // Skip methods not declared in site
2817 if (m.owner != site.tsym)
2818 continue;
2819
2820 // Gather all supertype methods overridden by m, directly or indirectly
2821 ArrayList<MethodSymbol> overriddenMethods = list.stream()
2822 .filter(m2 -> m2 != m && overrides.test(m, m2))
2823 .collect(Collectors.toCollection(ArrayList::new));
2824
2825 // Eliminate non-direct overrides
2826 removePreempted(overriddenMethods, overrides);
2827
2828 // Add to map
2829 overriddenMethodsMap.put(m, overriddenMethods);
2830 }
2831 });
2832
2833 // Build the predicate
2834 return (m1, m2) -> {
2835
2836 // Get corresponding supertype methods (if declared in site)
2837 java.util.List<MethodSymbol> overriddenMethods1 = overriddenMethodsMap.get(m1);
2838 java.util.List<MethodSymbol> overriddenMethods2 = overriddenMethodsMap.get(m2);
2839
2840 // Quick check for the case where a method was added by site itself
2841 if (overriddenMethods1 != null && overriddenMethods1.isEmpty())
2842 return true;
2843 if (overriddenMethods2 != null && overriddenMethods2.isEmpty())
2844 return true;
2845
2846 // Get each method's corresponding method(s) from supertypes of site
2847 java.util.List<MethodSymbol> supertypeMethods1 = overriddenMethods1 != null ?
2848 overriddenMethods1 : Collections.singletonList(m1);
2849 java.util.List<MethodSymbol> supertypeMethods2 = overriddenMethods2 != null ?
2850 overriddenMethods2 : Collections.singletonList(m2);
2851
2852 // See if we can blame some direct supertype instead
2853 return types.directSupertypes(site).stream()
2854 .filter(stype -> stype != syms.objectType)
2855 .map(stype -> stype.tsym.type) // view supertype in its original form
2856 .noneMatch(stype -> {
2857 for (MethodSymbol sm1 : supertypeMethods1) {
2858 if (!types.isSubtype(types.erasure(stype), types.erasure(sm1.owner.type)))
2859 continue;
2860 for (MethodSymbol sm2 : supertypeMethods2) {
2861 if (!types.isSubtype(types.erasure(stype), types.erasure(sm2.owner.type)))
2862 continue;
2863 if (potentiallyAmbiguousOverload(stype, sm1, sm2))
2864 return true;
2865 }
2866 }
2867 return false;
2868 });
2869 };
2870 }
2871
2872 /** Gather all of site's methods, including overridden methods, grouped and sorted by name,
2873 * after applying the given filter.
2874 */
2875 <C extends Collection<MethodSymbol>> List<C> methodsGroupedByName(Type site,
2876 Predicate<Symbol> filter, Supplier<? extends C> groupMaker) {
2877 Iterable<Symbol> symbols = types.membersClosure(site, false).getSymbols(filter, RECURSIVE);
2878 return StreamSupport.stream(symbols.spliterator(), false)
2879 .map(MethodSymbol.class::cast)
2880 .collect(Collectors.groupingBy(m -> m.name, Collectors.toCollection(groupMaker)))
2881 .entrySet()
2882 .stream()
2883 .sorted(Comparator.comparing(e -> e.getKey().toString()))
2884 .map(Map.Entry::getValue)
2885 .collect(List.collector());
2886 }
2887
2888 /** Compare elements in a list pair-wise in order to remove some of them.
2889 * @param list mutable list of items
2890 * @param comparer returns flag bit(s) to remove FIRST and/or SECOND
2891 */
2892 <T> void compareAndRemove(java.util.List<T> list, ToIntBiFunction<? super T, ? super T> comparer) {
2893 for (int index1 = 0; index1 < list.size() - 1; index1++) {
2894 T item1 = list.get(index1);
2895 for (int index2 = index1 + 1; index2 < list.size(); index2++) {
2896 T item2 = list.get(index2);
2897 int flags = comparer.applyAsInt(item1, item2);
2898 if ((flags & SECOND) != 0)
2899 list.remove(index2--); // remove item2
2900 if ((flags & FIRST) != 0) {
2901 list.remove(index1--); // remove item1
2902 break;
2903 }
2904 }
2905 }
2906 }
2907
2908 /** Remove elements in a list that are preempted by some other element in the list.
2909 * @param list mutable list of items
2910 * @param preempts decides if one item preempts another, causing the second one to be removed
2911 */
2912 <T> void removePreempted(java.util.List<T> list, BiPredicate<? super T, ? super T> preempts) {
2913 compareAndRemove(list, (item1, item2) -> {
2914 int flags = 0;
2915 if (preempts.test(item1, item2))
2916 flags |= SECOND;
2917 if (preempts.test(item2, item1))
2918 flags |= FIRST;
2919 return flags;
2920 });
2921 }
2922
2923 /** Filters method candidates for the "potentially ambiguous method" check */
2924 class PotentiallyAmbiguousFilter extends ClashFilter {
2925
2926 PotentiallyAmbiguousFilter(Type site) {
2927 super(site);
2928 }
2929
2930 @Override
2931 boolean shouldSkip(Symbol s) {
2932 return s.owner.type.tsym == syms.objectType.tsym || super.shouldSkip(s);
2933 }
2934 }
2935
2936 /**
2937 * Report warnings for potentially ambiguous method declarations. Two declarations
2938 * are potentially ambiguous if they feature two unrelated functional interface
2939 * in same argument position (in which case, a call site passing an implicit
2940 * lambda would be ambiguous). This assumes they already have the same name.
2941 */
2942 boolean potentiallyAmbiguousOverload(Type site, MethodSymbol msym1, MethodSymbol msym2) {
2943 Assert.check(msym1.name == msym2.name);
2944 if (msym1 == msym2)
2945 return false;
2946 Type mt1 = types.memberType(site, msym1);
2947 Type mt2 = types.memberType(site, msym2);
2948 //if both generic methods, adjust type variables
2949 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL) &&
2950 types.hasSameBounds((ForAll)mt1, (ForAll)mt2)) {
2951 mt2 = types.subst(mt2, ((ForAll)mt2).tvars, ((ForAll)mt1).tvars);
2952 }
2953 //expand varargs methods if needed
2954 int maxLength = Math.max(mt1.getParameterTypes().length(), mt2.getParameterTypes().length());
2955 List<Type> args1 = rs.adjustArgs(mt1.getParameterTypes(), msym1, maxLength, true);
2956 List<Type> args2 = rs.adjustArgs(mt2.getParameterTypes(), msym2, maxLength, true);
2957 //if arities don't match, exit
2958 if (args1.length() != args2.length())
2959 return false;
2960 boolean potentiallyAmbiguous = false;
2961 while (args1.nonEmpty() && args2.nonEmpty()) {
2962 Type s = args1.head;
2963 Type t = args2.head;
2964 if (!types.isSubtype(t, s) && !types.isSubtype(s, t)) {
2965 if (types.isFunctionalInterface(s) && types.isFunctionalInterface(t) &&
2966 types.findDescriptorType(s).getParameterTypes().length() > 0 &&
2967 types.findDescriptorType(s).getParameterTypes().length() ==
2968 types.findDescriptorType(t).getParameterTypes().length()) {
2969 potentiallyAmbiguous = true;
2970 } else {
2971 return false;
2972 }
2973 }
2974 args1 = args1.tail;
2975 args2 = args2.tail;
2976 }
2977 return potentiallyAmbiguous;
2978 }
2979
2980 // Apply special flag "-XDwarnOnAccessToMembers" which turns on just this particular warning for all types of access
2981 void checkAccessFromSerializableElement(final JCTree tree, boolean isLambda) {
2982 if (warnOnAnyAccessToMembers || isLambda)
2983 checkAccessFromSerializableElementInner(tree, isLambda);
2984 }
2985
2986 private void checkAccessFromSerializableElementInner(final JCTree tree, boolean isLambda) {
2987 Symbol sym = TreeInfo.symbol(tree);
2988 if (!sym.kind.matches(KindSelector.VAL_MTH)) {
2989 return;
2990 }
2991
2992 if (sym.kind == VAR) {
2993 if ((sym.flags() & PARAMETER) != 0 ||
2994 sym.isDirectlyOrIndirectlyLocal() ||
2995 sym.name == names._this ||
2996 sym.name == names._super) {
2997 return;
2998 }
2999 }
3000
3001 if (!types.isSubtype(sym.owner.type, syms.serializableType) && isEffectivelyNonPublic(sym)) {
3002 DiagnosticFlag flag = warnOnAnyAccessToMembers ? DiagnosticFlag.DEFAULT_ENABLED : null;
3003 if (isLambda) {
3004 if (belongsToRestrictedPackage(sym)) {
3005 log.warning(flag, tree.pos(), LintWarnings.AccessToMemberFromSerializableLambda(sym));
3006 }
3007 } else {
3008 log.warning(flag, tree.pos(), LintWarnings.AccessToMemberFromSerializableElement(sym));
3009 }
3010 }
3011 }
3012
3013 private boolean isEffectivelyNonPublic(Symbol sym) {
3014 if (sym.packge() == syms.rootPackage) {
3015 return false;
3016 }
3017
3018 while (sym.kind != PCK) {
3019 if ((sym.flags() & PUBLIC) == 0) {
3020 return true;
3021 }
3022 sym = sym.owner;
3023 }
3024 return false;
3025 }
3026
3027 private boolean belongsToRestrictedPackage(Symbol sym) {
3028 String fullName = sym.packge().fullname.toString();
3029 return fullName.startsWith("java.") ||
3030 fullName.startsWith("javax.") ||
3031 fullName.startsWith("sun.") ||
3032 fullName.contains(".internal.");
3033 }
3034
3035 /** Check that class c does not implement directly or indirectly
3036 * the same parameterized interface with two different argument lists.
3037 * @param pos Position to be used for error reporting.
3038 * @param type The type whose interfaces are checked.
3039 */
3040 void checkClassBounds(DiagnosticPosition pos, Type type) {
3041 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
3042 }
3043 //where
3044 /** Enter all interfaces of type `type' into the hash table `seensofar'
3045 * with their class symbol as key and their type as value. Make
3046 * sure no class is entered with two different types.
3047 */
3048 void checkClassBounds(DiagnosticPosition pos,
3049 Map<TypeSymbol,Type> seensofar,
3050 Type type) {
3051 if (type.isErroneous()) return;
3052 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
3053 Type it = l.head;
3054 if (type.hasTag(CLASS) && !it.hasTag(CLASS)) continue; // JLS 8.1.5
3055
3056 Type oldit = seensofar.put(it.tsym, it);
3057 if (oldit != null) {
3058 List<Type> oldparams = oldit.allparams();
3059 List<Type> newparams = it.allparams();
3060 if (!types.containsTypeEquivalent(oldparams, newparams))
3061 log.error(pos,
3062 Errors.CantInheritDiffArg(it.tsym,
3063 Type.toString(oldparams),
3064 Type.toString(newparams)));
3065 }
3066 checkClassBounds(pos, seensofar, it);
3067 }
3068 Type st = types.supertype(type);
3069 if (type.hasTag(CLASS) && !st.hasTag(CLASS)) return; // JLS 8.1.4
3070 if (st != Type.noType) checkClassBounds(pos, seensofar, st);
3071 }
3072
3073 /** Enter interface into into set.
3074 * If it existed already, issue a "repeated interface" error.
3075 */
3076 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Symbol> its) {
3077 if (its.contains(it.tsym))
3078 log.error(pos, Errors.RepeatedInterface);
3079 else {
3080 its.add(it.tsym);
3081 }
3082 }
3083
3084 /* *************************************************************************
3085 * Check annotations
3086 **************************************************************************/
3087
3088 /**
3089 * Recursively validate annotations values
3090 */
3091 void validateAnnotationTree(JCTree tree) {
3092 class AnnotationValidator extends TreeScanner {
3093 @Override
3094 public void visitAnnotation(JCAnnotation tree) {
3095 if (!tree.type.isErroneous() && tree.type.tsym.isAnnotationType()) {
3096 super.visitAnnotation(tree);
3097 validateAnnotation(tree);
3098 }
3099 }
3100 }
3101 tree.accept(new AnnotationValidator());
3102 }
3103
3104 /**
3105 * {@literal
3106 * Annotation types are restricted to primitives, String, an
3107 * enum, an annotation, Class, Class<?>, Class<? extends
3108 * Anything>, arrays of the preceding.
3109 * }
3110 */
3111 void validateAnnotationType(JCTree restype) {
3112 // restype may be null if an error occurred, so don't bother validating it
3113 if (restype != null) {
3114 validateAnnotationType(restype.pos(), restype.type);
3115 }
3116 }
3117
3118 void validateAnnotationType(DiagnosticPosition pos, Type type) {
3119 if (type.isPrimitive()) return;
3120 if (types.isSameType(type, syms.stringType)) return;
3121 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
3122 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
3123 if (types.cvarLowerBound(type).tsym == syms.classType.tsym) return;
3124 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
3125 validateAnnotationType(pos, types.elemtype(type));
3126 return;
3127 }
3128 log.error(pos, Errors.InvalidAnnotationMemberType);
3129 }
3130
3131 /**
3132 * "It is also a compile-time error if any method declared in an
3133 * annotation type has a signature that is override-equivalent to
3134 * that of any public or protected method declared in class Object
3135 * or in the interface annotation.Annotation."
3136 *
3137 * @jls 9.6 Annotation Types
3138 */
3139 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
3140 for (Type sup = syms.annotationType; sup.hasTag(CLASS); sup = types.supertype(sup)) {
3141 Scope s = sup.tsym.members();
3142 for (Symbol sym : s.getSymbolsByName(m.name)) {
3143 if (sym.kind == MTH &&
3144 (sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
3145 types.overrideEquivalent(m.type, sym.type))
3146 log.error(pos, Errors.IntfAnnotationMemberClash(sym, sup));
3147 }
3148 }
3149 }
3150
3151 /** Check the annotations of a symbol.
3152 */
3153 public void validateAnnotations(List<JCAnnotation> annotations, JCTree declarationTree, Symbol s) {
3154 for (JCAnnotation a : annotations)
3155 validateAnnotation(a, declarationTree, s);
3156 }
3157
3158 /** Check the type annotations.
3159 */
3160 public void validateTypeAnnotations(List<JCAnnotation> annotations, Symbol s, boolean isTypeParameter) {
3161 for (JCAnnotation a : annotations)
3162 validateTypeAnnotation(a, s, isTypeParameter);
3163 }
3164
3165 /** Check an annotation of a symbol.
3166 */
3167 private void validateAnnotation(JCAnnotation a, JCTree declarationTree, Symbol s) {
3168 /** NOTE: if annotation processors are present, annotation processing rounds can happen after this method,
3169 * this can impact in particular records for which annotations are forcibly propagated.
3170 */
3171 validateAnnotationTree(a);
3172 boolean isRecordMember = ((s.flags_field & RECORD) != 0 || s.enclClass() != null && s.enclClass().isRecord());
3173
3174 boolean isRecordField = (s.flags_field & RECORD) != 0 &&
3175 declarationTree.hasTag(VARDEF) &&
3176 s.owner.kind == TYP;
3177
3178 if (isRecordField) {
3179 // first we need to check if the annotation is applicable to records
3180 Name[] targets = getTargetNames(a);
3181 boolean appliesToRecords = false;
3182 for (Name target : targets) {
3183 appliesToRecords =
3184 target == names.FIELD ||
3185 target == names.PARAMETER ||
3186 target == names.METHOD ||
3187 target == names.TYPE_USE ||
3188 target == names.RECORD_COMPONENT;
3189 if (appliesToRecords) {
3190 break;
3191 }
3192 }
3193 if (!appliesToRecords) {
3194 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3195 } else {
3196 /* lets now find the annotations in the field that are targeted to record components and append them to
3197 * the corresponding record component
3198 */
3199 ClassSymbol recordClass = (ClassSymbol) s.owner;
3200 RecordComponent rc = recordClass.getRecordComponent((VarSymbol)s);
3201 SymbolMetadata metadata = rc.getMetadata();
3202 if (metadata == null || metadata.isEmpty()) {
3203 /* if not is empty then we have already been here, which is the case if multiple annotations are applied
3204 * to the record component declaration
3205 */
3206 rc.appendAttributes(s.getRawAttributes().stream().filter(anno ->
3207 Arrays.stream(getTargetNames(anno.type.tsym)).anyMatch(name -> name == names.RECORD_COMPONENT)
3208 ).collect(List.collector()));
3209
3210 JCVariableDecl fieldAST = (JCVariableDecl) declarationTree;
3211 for (JCAnnotation fieldAnnot : fieldAST.mods.annotations) {
3212 for (JCAnnotation rcAnnot : rc.declarationFor().mods.annotations) {
3213 if (rcAnnot.pos == fieldAnnot.pos) {
3214 rcAnnot.setType(fieldAnnot.type);
3215 break;
3216 }
3217 }
3218 }
3219
3220 /* At this point, we used to carry over any type annotations from the VARDEF to the record component, but
3221 * that is problematic, since we get here only when *some* annotation is applied to the SE5 (declaration)
3222 * annotation location, inadvertently failing to carry over the type annotations when the VarDef has no
3223 * annotations in the SE5 annotation location.
3224 *
3225 * Now type annotations are assigned to record components in a method that would execute irrespective of
3226 * whether there are SE5 annotations on a VarDef viz com.sun.tools.javac.code.TypeAnnotations.TypeAnnotationPositions.visitVarDef
3227 */
3228 }
3229 }
3230 }
3231
3232 /* the section below is tricky. Annotations applied to record components are propagated to the corresponding
3233 * record member so if an annotation has target: FIELD, it is propagated to the corresponding FIELD, if it has
3234 * target METHOD, it is propagated to the accessor and so on. But at the moment when method members are generated
3235 * there is no enough information to propagate only the right annotations. So all the annotations are propagated
3236 * to all the possible locations.
3237 *
3238 * At this point we need to remove all the annotations that are not in place before going on with the annotation
3239 * party. On top of the above there is the issue that there is no AST representing record components, just symbols
3240 * so the corresponding field has been holding all the annotations and it's metadata has been modified as if it
3241 * was both a field and a record component.
3242 *
3243 * So there are two places where we need to trim annotations from: the metadata of the symbol and / or the modifiers
3244 * in the AST. Whatever is in the metadata will be written to the class file, whatever is in the modifiers could
3245 * be see by annotation processors.
3246 *
3247 * The metadata contains both type annotations and declaration annotations. At this point of the game we don't
3248 * need to care about type annotations, they are all in the right place. But we could need to remove declaration
3249 * annotations. So for declaration annotations if they are not applicable to the record member, excluding type
3250 * annotations which are already correct, then we will remove it. For the AST modifiers if the annotation is not
3251 * applicable either as type annotation and or declaration annotation, only in that case it will be removed.
3252 *
3253 * So it could be that annotation is removed as a declaration annotation but it is kept in the AST modifier for
3254 * further inspection by annotation processors.
3255 *
3256 * For example:
3257 *
3258 * import java.lang.annotation.*;
3259 *
3260 * @Target({ElementType.TYPE_USE, ElementType.RECORD_COMPONENT})
3261 * @Retention(RetentionPolicy.RUNTIME)
3262 * @interface Anno { }
3263 *
3264 * record R(@Anno String s) {}
3265 *
3266 * at this point we will have for the case of the generated field:
3267 * - @Anno in the modifier
3268 * - @Anno as a type annotation
3269 * - @Anno as a declaration annotation
3270 *
3271 * the last one should be removed because the annotation has not FIELD as target but it was applied as a
3272 * declaration annotation because the field was being treated both as a field and as a record component
3273 * as we have already copied the annotations to the record component, now the field doesn't need to hold
3274 * annotations that are not intended for it anymore. Still @Anno has to be kept in the AST's modifiers as it
3275 * is applicable as a type annotation to the type of the field.
3276 */
3277
3278 if (a.type.tsym.isAnnotationType()) {
3279 Optional<Set<Name>> applicableTargetsOp = getApplicableTargets(a, s);
3280 if (!applicableTargetsOp.isEmpty()) {
3281 Set<Name> applicableTargets = applicableTargetsOp.get();
3282 boolean notApplicableOrIsTypeUseOnly = applicableTargets.isEmpty() ||
3283 applicableTargets.size() == 1 && applicableTargets.contains(names.TYPE_USE);
3284 boolean isCompGeneratedRecordElement = isRecordMember && (s.flags_field & Flags.GENERATED_MEMBER) != 0;
3285 boolean isCompRecordElementWithNonApplicableDeclAnno = isCompGeneratedRecordElement && notApplicableOrIsTypeUseOnly;
3286
3287 if (applicableTargets.isEmpty() || isCompRecordElementWithNonApplicableDeclAnno) {
3288 if (isCompRecordElementWithNonApplicableDeclAnno) {
3289 /* so we have found an annotation that is not applicable to a record member that was generated by the
3290 * compiler. This was intentionally done at TypeEnter, now is the moment strip away the annotations
3291 * that are not applicable to the given record member
3292 */
3293 JCModifiers modifiers = TreeInfo.getModifiers(declarationTree);
3294 /* lets first remove the annotation from the modifier if it is not applicable, we have to check again as
3295 * it could be a type annotation
3296 */
3297 if (modifiers != null && applicableTargets.isEmpty()) {
3298 ListBuffer<JCAnnotation> newAnnotations = new ListBuffer<>();
3299 for (JCAnnotation anno : modifiers.annotations) {
3300 if (anno != a) {
3301 newAnnotations.add(anno);
3302 }
3303 }
3304 modifiers.annotations = newAnnotations.toList();
3305 }
3306 // now lets remove it from the symbol
3307 s.getMetadata().removeDeclarationMetadata(a.attribute);
3308 } else {
3309 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3310 }
3311 }
3312 /* if we are seeing the @SafeVarargs annotation applied to a compiler generated accessor,
3313 * then this is an error as we know that no compiler generated accessor will be a varargs
3314 * method, better to fail asap
3315 */
3316 if (isCompGeneratedRecordElement && !isRecordField && a.type.tsym == syms.trustMeType.tsym && declarationTree.hasTag(METHODDEF)) {
3317 log.error(a.pos(), Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym, Fragments.VarargsTrustmeOnNonVarargsAccessor(s)));
3318 }
3319 }
3320 }
3321
3322 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
3323 if (s.kind != TYP) {
3324 log.error(a.pos(), Errors.BadFunctionalIntfAnno);
3325 } else if (!s.isInterface() || (s.flags() & ANNOTATION) != 0) {
3326 log.error(a.pos(), Errors.BadFunctionalIntfAnno1(Fragments.NotAFunctionalIntf(s)));
3327 }
3328 }
3329 }
3330
3331 public void validateTypeAnnotation(JCAnnotation a, Symbol s, boolean isTypeParameter) {
3332 Assert.checkNonNull(a.type);
3333 // we just want to validate that the anotation doesn't have any wrong target
3334 if (s != null) getApplicableTargets(a, s);
3335 validateAnnotationTree(a);
3336
3337 if (a.hasTag(TYPE_ANNOTATION) &&
3338 !a.annotationType.type.isErroneous() &&
3339 !isTypeAnnotation(a, isTypeParameter)) {
3340 log.error(a.pos(), Errors.AnnotationTypeNotApplicableToType(a.type));
3341 }
3342 }
3343
3344 /**
3345 * Validate the proposed container 'repeatable' on the
3346 * annotation type symbol 's'. Report errors at position
3347 * 'pos'.
3348 *
3349 * @param s The (annotation)type declaration annotated with a @Repeatable
3350 * @param repeatable the @Repeatable on 's'
3351 * @param pos where to report errors
3352 */
3353 public void validateRepeatable(TypeSymbol s, Attribute.Compound repeatable, DiagnosticPosition pos) {
3354 Assert.check(types.isSameType(repeatable.type, syms.repeatableType));
3355
3356 Type t = null;
3357 List<Pair<MethodSymbol,Attribute>> l = repeatable.values;
3358 if (!l.isEmpty()) {
3359 Assert.check(l.head.fst.name == names.value);
3360 if (l.head.snd instanceof Attribute.Class) {
3361 t = ((Attribute.Class)l.head.snd).getValue();
3362 }
3363 }
3364
3365 if (t == null) {
3366 // errors should already have been reported during Annotate
3367 return;
3368 }
3369
3370 validateValue(t.tsym, s, pos);
3371 validateRetention(t.tsym, s, pos);
3372 validateDocumented(t.tsym, s, pos);
3373 validateInherited(t.tsym, s, pos);
3374 validateTarget(t.tsym, s, pos);
3375 validateDefault(t.tsym, pos);
3376 }
3377
3378 private void validateValue(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3379 Symbol sym = container.members().findFirst(names.value);
3380 if (sym != null && sym.kind == MTH) {
3381 MethodSymbol m = (MethodSymbol) sym;
3382 Type ret = m.getReturnType();
3383 if (!(ret.hasTag(ARRAY) && types.isSameType(((ArrayType)ret).elemtype, contained.type))) {
3384 log.error(pos,
3385 Errors.InvalidRepeatableAnnotationValueReturn(container,
3386 ret,
3387 types.makeArrayType(contained.type)));
3388 }
3389 } else {
3390 log.error(pos, Errors.InvalidRepeatableAnnotationNoValue(container));
3391 }
3392 }
3393
3394 private void validateRetention(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3395 Attribute.RetentionPolicy containerRetention = types.getRetention(container);
3396 Attribute.RetentionPolicy containedRetention = types.getRetention(contained);
3397
3398 boolean error = false;
3399 switch (containedRetention) {
3400 case RUNTIME:
3401 if (containerRetention != Attribute.RetentionPolicy.RUNTIME) {
3402 error = true;
3403 }
3404 break;
3405 case CLASS:
3406 if (containerRetention == Attribute.RetentionPolicy.SOURCE) {
3407 error = true;
3408 }
3409 }
3410 if (error ) {
3411 log.error(pos,
3412 Errors.InvalidRepeatableAnnotationRetention(container,
3413 containerRetention.name(),
3414 contained,
3415 containedRetention.name()));
3416 }
3417 }
3418
3419 private void validateDocumented(Symbol container, Symbol contained, DiagnosticPosition pos) {
3420 if (contained.attribute(syms.documentedType.tsym) != null) {
3421 if (container.attribute(syms.documentedType.tsym) == null) {
3422 log.error(pos, Errors.InvalidRepeatableAnnotationNotDocumented(container, contained));
3423 }
3424 }
3425 }
3426
3427 private void validateInherited(Symbol container, Symbol contained, DiagnosticPosition pos) {
3428 if (contained.attribute(syms.inheritedType.tsym) != null) {
3429 if (container.attribute(syms.inheritedType.tsym) == null) {
3430 log.error(pos, Errors.InvalidRepeatableAnnotationNotInherited(container, contained));
3431 }
3432 }
3433 }
3434
3435 private void validateTarget(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3436 // The set of targets the container is applicable to must be a subset
3437 // (with respect to annotation target semantics) of the set of targets
3438 // the contained is applicable to. The target sets may be implicit or
3439 // explicit.
3440
3441 Set<Name> containerTargets;
3442 Attribute.Array containerTarget = getAttributeTargetAttribute(container);
3443 if (containerTarget == null) {
3444 containerTargets = getDefaultTargetSet();
3445 } else {
3446 containerTargets = new HashSet<>();
3447 for (Attribute app : containerTarget.values) {
3448 if (!(app instanceof Attribute.Enum attributeEnum)) {
3449 continue; // recovery
3450 }
3451 containerTargets.add(attributeEnum.value.name);
3452 }
3453 }
3454
3455 Set<Name> containedTargets;
3456 Attribute.Array containedTarget = getAttributeTargetAttribute(contained);
3457 if (containedTarget == null) {
3458 containedTargets = getDefaultTargetSet();
3459 } else {
3460 containedTargets = new HashSet<>();
3461 for (Attribute app : containedTarget.values) {
3462 if (!(app instanceof Attribute.Enum attributeEnum)) {
3463 continue; // recovery
3464 }
3465 containedTargets.add(attributeEnum.value.name);
3466 }
3467 }
3468
3469 if (!isTargetSubsetOf(containerTargets, containedTargets)) {
3470 log.error(pos, Errors.InvalidRepeatableAnnotationIncompatibleTarget(container, contained));
3471 }
3472 }
3473
3474 /* get a set of names for the default target */
3475 private Set<Name> getDefaultTargetSet() {
3476 if (defaultTargets == null) {
3477 defaultTargets = Set.of(defaultTargetMetaInfo());
3478 }
3479
3480 return defaultTargets;
3481 }
3482 private Set<Name> defaultTargets;
3483
3484
3485 /** Checks that s is a subset of t, with respect to ElementType
3486 * semantics, specifically {ANNOTATION_TYPE} is a subset of {TYPE},
3487 * and {TYPE_USE} covers the set {ANNOTATION_TYPE, TYPE, TYPE_USE,
3488 * TYPE_PARAMETER}.
3489 */
3490 private boolean isTargetSubsetOf(Set<Name> s, Set<Name> t) {
3491 // Check that all elements in s are present in t
3492 for (Name n2 : s) {
3493 boolean currentElementOk = false;
3494 for (Name n1 : t) {
3495 if (n1 == n2) {
3496 currentElementOk = true;
3497 break;
3498 } else if (n1 == names.TYPE && n2 == names.ANNOTATION_TYPE) {
3499 currentElementOk = true;
3500 break;
3501 } else if (n1 == names.TYPE_USE &&
3502 (n2 == names.TYPE ||
3503 n2 == names.ANNOTATION_TYPE ||
3504 n2 == names.TYPE_PARAMETER)) {
3505 currentElementOk = true;
3506 break;
3507 }
3508 }
3509 if (!currentElementOk)
3510 return false;
3511 }
3512 return true;
3513 }
3514
3515 private void validateDefault(Symbol container, DiagnosticPosition pos) {
3516 // validate that all other elements of containing type has defaults
3517 Scope scope = container.members();
3518 for(Symbol elm : scope.getSymbols()) {
3519 if (elm.name != names.value &&
3520 elm.kind == MTH &&
3521 ((MethodSymbol)elm).defaultValue == null) {
3522 log.error(pos,
3523 Errors.InvalidRepeatableAnnotationElemNondefault(container, elm));
3524 }
3525 }
3526 }
3527
3528 /** Is s a method symbol that overrides a method in a superclass? */
3529 boolean isOverrider(Symbol s) {
3530 if (s.kind != MTH || s.isStatic())
3531 return false;
3532 MethodSymbol m = (MethodSymbol)s;
3533 TypeSymbol owner = (TypeSymbol)m.owner;
3534 for (Type sup : types.closure(owner.type)) {
3535 if (sup == owner.type)
3536 continue; // skip "this"
3537 Scope scope = sup.tsym.members();
3538 for (Symbol sym : scope.getSymbolsByName(m.name)) {
3539 if (!sym.isStatic() && m.overrides(sym, owner, types, true))
3540 return true;
3541 }
3542 }
3543 return false;
3544 }
3545
3546 /** Is the annotation applicable to types? */
3547 protected boolean isTypeAnnotation(JCAnnotation a, boolean isTypeParameter) {
3548 List<Attribute> targets = typeAnnotations.annotationTargets(a.annotationType.type.tsym);
3549 return (targets == null) ?
3550 (Feature.NO_TARGET_ANNOTATION_APPLICABILITY.allowedInSource(source) && isTypeParameter) :
3551 targets.stream()
3552 .anyMatch(attr -> isTypeAnnotation(attr, isTypeParameter));
3553 }
3554 //where
3555 boolean isTypeAnnotation(Attribute a, boolean isTypeParameter) {
3556 Attribute.Enum e = (Attribute.Enum)a;
3557 return (e.value.name == names.TYPE_USE ||
3558 (isTypeParameter && e.value.name == names.TYPE_PARAMETER));
3559 }
3560
3561 /** Is the annotation applicable to the symbol? */
3562 Name[] getTargetNames(JCAnnotation a) {
3563 return getTargetNames(a.annotationType.type.tsym);
3564 }
3565
3566 public Name[] getTargetNames(TypeSymbol annoSym) {
3567 Attribute.Array arr = getAttributeTargetAttribute(annoSym);
3568 Name[] targets;
3569 if (arr == null) {
3570 targets = defaultTargetMetaInfo();
3571 } else {
3572 // TODO: can we optimize this?
3573 targets = new Name[arr.values.length];
3574 for (int i=0; i<arr.values.length; ++i) {
3575 Attribute app = arr.values[i];
3576 if (!(app instanceof Attribute.Enum attributeEnum)) {
3577 return new Name[0];
3578 }
3579 targets[i] = attributeEnum.value.name;
3580 }
3581 }
3582 return targets;
3583 }
3584
3585 boolean annotationApplicable(JCAnnotation a, Symbol s) {
3586 Optional<Set<Name>> targets = getApplicableTargets(a, s);
3587 /* the optional could be empty if the annotation is unknown in that case
3588 * we return that it is applicable and if it is erroneous that should imply
3589 * an error at the declaration site
3590 */
3591 return targets.isEmpty() || targets.isPresent() && !targets.get().isEmpty();
3592 }
3593
3594 Optional<Set<Name>> getApplicableTargets(JCAnnotation a, Symbol s) {
3595 Attribute.Array arr = getAttributeTargetAttribute(a.annotationType.type.tsym);
3596 Name[] targets;
3597 Set<Name> applicableTargets = new HashSet<>();
3598
3599 if (arr == null) {
3600 targets = defaultTargetMetaInfo();
3601 } else {
3602 // TODO: can we optimize this?
3603 targets = new Name[arr.values.length];
3604 for (int i=0; i<arr.values.length; ++i) {
3605 Attribute app = arr.values[i];
3606 if (!(app instanceof Attribute.Enum attributeEnum)) {
3607 // recovery
3608 return Optional.empty();
3609 }
3610 targets[i] = attributeEnum.value.name;
3611 }
3612 }
3613 for (Name target : targets) {
3614 if (target == names.TYPE) {
3615 if (s.kind == TYP)
3616 applicableTargets.add(names.TYPE);
3617 } else if (target == names.FIELD) {
3618 if (s.kind == VAR && s.owner.kind != MTH)
3619 applicableTargets.add(names.FIELD);
3620 } else if (target == names.RECORD_COMPONENT) {
3621 if (s.getKind() == ElementKind.RECORD_COMPONENT) {
3622 applicableTargets.add(names.RECORD_COMPONENT);
3623 }
3624 } else if (target == names.METHOD) {
3625 if (s.kind == MTH && !s.isConstructor())
3626 applicableTargets.add(names.METHOD);
3627 } else if (target == names.PARAMETER) {
3628 if (s.kind == VAR &&
3629 (s.owner.kind == MTH && (s.flags() & PARAMETER) != 0)) {
3630 applicableTargets.add(names.PARAMETER);
3631 }
3632 } else if (target == names.CONSTRUCTOR) {
3633 if (s.kind == MTH && s.isConstructor())
3634 applicableTargets.add(names.CONSTRUCTOR);
3635 } else if (target == names.LOCAL_VARIABLE) {
3636 if (s.kind == VAR && s.owner.kind == MTH &&
3637 (s.flags() & PARAMETER) == 0) {
3638 applicableTargets.add(names.LOCAL_VARIABLE);
3639 }
3640 } else if (target == names.ANNOTATION_TYPE) {
3641 if (s.kind == TYP && (s.flags() & ANNOTATION) != 0) {
3642 applicableTargets.add(names.ANNOTATION_TYPE);
3643 }
3644 } else if (target == names.PACKAGE) {
3645 if (s.kind == PCK)
3646 applicableTargets.add(names.PACKAGE);
3647 } else if (target == names.TYPE_USE) {
3648 if (s.kind == VAR && s.owner.kind == MTH && s.type.hasTag(NONE)) {
3649 //cannot type annotate implicitly typed locals
3650 continue;
3651 } else if (s.kind == TYP || s.kind == VAR ||
3652 (s.kind == MTH && !s.isConstructor() &&
3653 !s.type.getReturnType().hasTag(VOID)) ||
3654 (s.kind == MTH && s.isConstructor())) {
3655 applicableTargets.add(names.TYPE_USE);
3656 }
3657 } else if (target == names.TYPE_PARAMETER) {
3658 if (s.kind == TYP && s.type.hasTag(TYPEVAR))
3659 applicableTargets.add(names.TYPE_PARAMETER);
3660 } else if (target == names.MODULE) {
3661 if (s.kind == MDL)
3662 applicableTargets.add(names.MODULE);
3663 } else {
3664 log.error(a, Errors.AnnotationUnrecognizedAttributeName(a.type, target));
3665 return Optional.empty(); // Unknown ElementType
3666 }
3667 }
3668 return Optional.of(applicableTargets);
3669 }
3670
3671 Attribute.Array getAttributeTargetAttribute(TypeSymbol s) {
3672 Attribute.Compound atTarget = s.getAnnotationTypeMetadata().getTarget();
3673 if (atTarget == null) return null; // ok, is applicable
3674 Attribute atValue = atTarget.member(names.value);
3675 return (atValue instanceof Attribute.Array attributeArray) ? attributeArray : null;
3676 }
3677
3678 private Name[] dfltTargetMeta;
3679 private Name[] defaultTargetMetaInfo() {
3680 if (dfltTargetMeta == null) {
3681 ArrayList<Name> defaultTargets = new ArrayList<>();
3682 defaultTargets.add(names.PACKAGE);
3683 defaultTargets.add(names.TYPE);
3684 defaultTargets.add(names.FIELD);
3685 defaultTargets.add(names.METHOD);
3686 defaultTargets.add(names.CONSTRUCTOR);
3687 defaultTargets.add(names.ANNOTATION_TYPE);
3688 defaultTargets.add(names.LOCAL_VARIABLE);
3689 defaultTargets.add(names.PARAMETER);
3690 if (allowRecords) {
3691 defaultTargets.add(names.RECORD_COMPONENT);
3692 }
3693 if (allowModules) {
3694 defaultTargets.add(names.MODULE);
3695 }
3696 dfltTargetMeta = defaultTargets.toArray(new Name[0]);
3697 }
3698 return dfltTargetMeta;
3699 }
3700
3701 /** Check an annotation value.
3702 *
3703 * @param a The annotation tree to check
3704 * @return true if this annotation tree is valid, otherwise false
3705 */
3706 public boolean validateAnnotationDeferErrors(JCAnnotation a) {
3707 boolean res = false;
3708 final Log.DiagnosticHandler diagHandler = log.new DiscardDiagnosticHandler();
3709 try {
3710 res = validateAnnotation(a);
3711 } finally {
3712 log.popDiagnosticHandler(diagHandler);
3713 }
3714 return res;
3715 }
3716
3717 private boolean validateAnnotation(JCAnnotation a) {
3718 boolean isValid = true;
3719 AnnotationTypeMetadata metadata = a.annotationType.type.tsym.getAnnotationTypeMetadata();
3720
3721 // collect an inventory of the annotation elements
3722 Set<MethodSymbol> elements = metadata.getAnnotationElements();
3723
3724 // remove the ones that are assigned values
3725 for (JCTree arg : a.args) {
3726 if (!arg.hasTag(ASSIGN)) continue; // recovery
3727 JCAssign assign = (JCAssign)arg;
3728 Symbol m = TreeInfo.symbol(assign.lhs);
3729 if (m == null || m.type.isErroneous()) continue;
3730 if (!elements.remove(m)) {
3731 isValid = false;
3732 log.error(assign.lhs.pos(),
3733 Errors.DuplicateAnnotationMemberValue(m.name, a.type));
3734 }
3735 }
3736
3737 // all the remaining ones better have default values
3738 List<Name> missingDefaults = List.nil();
3739 Set<MethodSymbol> membersWithDefault = metadata.getAnnotationElementsWithDefault();
3740 for (MethodSymbol m : elements) {
3741 if (m.type.isErroneous())
3742 continue;
3743
3744 if (!membersWithDefault.contains(m))
3745 missingDefaults = missingDefaults.append(m.name);
3746 }
3747 missingDefaults = missingDefaults.reverse();
3748 if (missingDefaults.nonEmpty()) {
3749 isValid = false;
3750 Error errorKey = (missingDefaults.size() > 1)
3751 ? Errors.AnnotationMissingDefaultValue1(a.type, missingDefaults)
3752 : Errors.AnnotationMissingDefaultValue(a.type, missingDefaults);
3753 log.error(a.pos(), errorKey);
3754 }
3755
3756 return isValid && validateTargetAnnotationValue(a);
3757 }
3758
3759 /* Validate the special java.lang.annotation.Target annotation */
3760 boolean validateTargetAnnotationValue(JCAnnotation a) {
3761 // special case: java.lang.annotation.Target must not have
3762 // repeated values in its value member
3763 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
3764 a.args.tail == null)
3765 return true;
3766
3767 boolean isValid = true;
3768 if (!a.args.head.hasTag(ASSIGN)) return false; // error recovery
3769 JCAssign assign = (JCAssign) a.args.head;
3770 Symbol m = TreeInfo.symbol(assign.lhs);
3771 if (m.name != names.value) return false;
3772 JCTree rhs = assign.rhs;
3773 if (!rhs.hasTag(NEWARRAY)) return false;
3774 JCNewArray na = (JCNewArray) rhs;
3775 Set<Symbol> targets = new HashSet<>();
3776 for (JCTree elem : na.elems) {
3777 if (!targets.add(TreeInfo.symbol(elem))) {
3778 isValid = false;
3779 log.error(elem.pos(), Errors.RepeatedAnnotationTarget);
3780 }
3781 }
3782 return isValid;
3783 }
3784
3785 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
3786 if (lint.isEnabled(LintCategory.DEP_ANN) && s.isDeprecatableViaAnnotation() &&
3787 (s.flags() & DEPRECATED) != 0 &&
3788 !syms.deprecatedType.isErroneous() &&
3789 s.attribute(syms.deprecatedType.tsym) == null) {
3790 log.warning(pos, LintWarnings.MissingDeprecatedAnnotation);
3791 }
3792 // Note: @Deprecated has no effect on local variables, parameters and package decls.
3793 if (lint.isEnabled(LintCategory.DEPRECATION) && !s.isDeprecatableViaAnnotation()) {
3794 if (!syms.deprecatedType.isErroneous() && s.attribute(syms.deprecatedType.tsym) != null) {
3795 log.warning(pos, LintWarnings.DeprecatedAnnotationHasNoEffect(Kinds.kindName(s)));
3796 }
3797 }
3798 }
3799
3800 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
3801 checkDeprecated(() -> pos, other, s);
3802 }
3803
3804 void checkDeprecated(Supplier<DiagnosticPosition> pos, final Symbol other, final Symbol s) {
3805 if (!importSuppression
3806 && (s.isDeprecatedForRemoval() || s.isDeprecated() && !other.isDeprecated())
3807 && (s.outermostClass() != other.outermostClass() || s.outermostClass() == null)
3808 && s.kind != Kind.PCK) {
3809 warnDeprecated(pos.get(), s);
3810 }
3811 }
3812
3813 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
3814 if ((s.flags() & PROPRIETARY) != 0) {
3815 log.warning(pos, Warnings.SunProprietary(s));
3816 }
3817 }
3818
3819 void checkProfile(final DiagnosticPosition pos, final Symbol s) {
3820 if (profile != Profile.DEFAULT && (s.flags() & NOT_IN_PROFILE) != 0) {
3821 log.error(pos, Errors.NotInProfile(s, profile));
3822 }
3823 }
3824
3825 void checkPreview(DiagnosticPosition pos, Symbol other, Symbol s) {
3826 checkPreview(pos, other, Type.noType, s);
3827 }
3828
3829 void checkPreview(DiagnosticPosition pos, Symbol other, Type site, Symbol s) {
3830 boolean sIsPreview;
3831 Symbol previewSymbol;
3832 if ((s.flags() & PREVIEW_API) != 0) {
3833 sIsPreview = true;
3834 previewSymbol= s;
3835 } else if ((s.kind == Kind.MTH || s.kind == Kind.VAR) &&
3836 site.tsym != null &&
3837 (site.tsym.flags() & PREVIEW_API) == 0 &&
3838 (s.owner.flags() & PREVIEW_API) != 0) {
3839 //calling a method, or using a field, whose owner is a preview, but
3840 //using a site that is not a preview. Also produce an error or warning:
3841 sIsPreview = true;
3842 previewSymbol = s.owner;
3843 } else {
3844 sIsPreview = false;
3845 previewSymbol = null;
3846 }
3847 if (sIsPreview && !preview.participatesInPreview(syms, other, s) && !disablePreviewCheck) {
3848 if ((previewSymbol.flags() & PREVIEW_REFLECTIVE) == 0) {
3849 if (!preview.isEnabled()) {
3850 log.error(pos, Errors.IsPreview(s));
3851 } else {
3852 preview.markUsesPreview(pos);
3853 warnPreviewAPI(pos, LintWarnings.IsPreview(s));
3854 }
3855 } else {
3856 warnPreviewAPI(pos, LintWarnings.IsPreviewReflective(s));
3857 }
3858 }
3859 if (preview.declaredUsingPreviewFeature(s)) {
3860 if (preview.isEnabled()) {
3861 //for preview disabled do presumably so not need to do anything?
3862 //If "s" is compiled from source, then there was an error for it already;
3863 //if "s" is from classfile, there already was an error for the classfile.
3864 preview.markUsesPreview(pos);
3865 warnPreviewAPI(pos, LintWarnings.DeclaredUsingPreview(kindName(s), s));
3866 }
3867 }
3868 }
3869
3870 void checkRestricted(DiagnosticPosition pos, Symbol s) {
3871 if (s.kind == MTH && (s.flags() & RESTRICTED) != 0) {
3872 log.warning(pos, LintWarnings.RestrictedMethod(s.enclClass(), s));
3873 }
3874 }
3875
3876 /* *************************************************************************
3877 * Check for recursive annotation elements.
3878 **************************************************************************/
3879
3880 /** Check for cycles in the graph of annotation elements.
3881 */
3882 void checkNonCyclicElements(JCClassDecl tree) {
3883 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
3884 Assert.check((tree.sym.flags_field & LOCKED) == 0);
3885 try {
3886 tree.sym.flags_field |= LOCKED;
3887 for (JCTree def : tree.defs) {
3888 if (!def.hasTag(METHODDEF)) continue;
3889 JCMethodDecl meth = (JCMethodDecl)def;
3890 checkAnnotationResType(meth.pos(), meth.restype.type);
3891 }
3892 } finally {
3893 tree.sym.flags_field &= ~LOCKED;
3894 tree.sym.flags_field |= ACYCLIC_ANN;
3895 }
3896 }
3897
3898 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
3899 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
3900 return;
3901 if ((tsym.flags_field & LOCKED) != 0) {
3902 log.error(pos, Errors.CyclicAnnotationElement(tsym));
3903 return;
3904 }
3905 try {
3906 tsym.flags_field |= LOCKED;
3907 for (Symbol s : tsym.members().getSymbols(NON_RECURSIVE)) {
3908 if (s.kind != MTH)
3909 continue;
3910 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
3911 }
3912 } finally {
3913 tsym.flags_field &= ~LOCKED;
3914 tsym.flags_field |= ACYCLIC_ANN;
3915 }
3916 }
3917
3918 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
3919 switch (type.getTag()) {
3920 case CLASS:
3921 if ((type.tsym.flags() & ANNOTATION) != 0)
3922 checkNonCyclicElementsInternal(pos, type.tsym);
3923 break;
3924 case ARRAY:
3925 checkAnnotationResType(pos, types.elemtype(type));
3926 break;
3927 default:
3928 break; // int etc
3929 }
3930 }
3931
3932 /* *************************************************************************
3933 * Check for cycles in the constructor call graph.
3934 **************************************************************************/
3935
3936 /** Check for cycles in the graph of constructors calling other
3937 * constructors.
3938 */
3939 void checkCyclicConstructors(JCClassDecl tree) {
3940 // use LinkedHashMap so we generate errors deterministically
3941 Map<Symbol,Symbol> callMap = new LinkedHashMap<>();
3942
3943 // enter each constructor this-call into the map
3944 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3945 if (!TreeInfo.isConstructor(l.head))
3946 continue;
3947 JCMethodDecl meth = (JCMethodDecl)l.head;
3948 JCMethodInvocation app = TreeInfo.findConstructorCall(meth);
3949 if (app != null && TreeInfo.name(app.meth) == names._this) {
3950 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
3951 } else {
3952 meth.sym.flags_field |= ACYCLIC;
3953 }
3954 }
3955
3956 // Check for cycles in the map
3957 Symbol[] ctors = new Symbol[0];
3958 ctors = callMap.keySet().toArray(ctors);
3959 for (Symbol caller : ctors) {
3960 checkCyclicConstructor(tree, caller, callMap);
3961 }
3962 }
3963
3964 /** Look in the map to see if the given constructor is part of a
3965 * call cycle.
3966 */
3967 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
3968 Map<Symbol,Symbol> callMap) {
3969 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
3970 if ((ctor.flags_field & LOCKED) != 0) {
3971 log.error(TreeInfo.diagnosticPositionFor(ctor, tree, false, t -> t.hasTag(IDENT)),
3972 Errors.RecursiveCtorInvocation);
3973 } else {
3974 ctor.flags_field |= LOCKED;
3975 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
3976 ctor.flags_field &= ~LOCKED;
3977 }
3978 ctor.flags_field |= ACYCLIC;
3979 }
3980 }
3981
3982 /* *************************************************************************
3983 * Verify the proper placement of super()/this() calls.
3984 *
3985 * - super()/this() may only appear in constructors
3986 * - There must be at most one super()/this() call per constructor
3987 * - The super()/this() call, if any, must be a top-level statement in the
3988 * constructor, i.e., not nested inside any other statement or block
3989 * - There must be no return statements prior to the super()/this() call
3990 **************************************************************************/
3991
3992 void checkSuperInitCalls(JCClassDecl tree) {
3993 new SuperThisChecker().check(tree);
3994 }
3995
3996 private class SuperThisChecker extends TreeScanner {
3997
3998 // Match this scan stack: 1=JCMethodDecl, 2=JCExpressionStatement, 3=JCMethodInvocation
3999 private static final int MATCH_SCAN_DEPTH = 3;
4000
4001 private boolean constructor; // is this method a constructor?
4002 private boolean firstStatement; // at the first statement in method?
4003 private JCReturn earlyReturn; // first return prior to the super()/init(), if any
4004 private Name initCall; // whichever of "super" or "init" we've seen already
4005 private int scanDepth; // current scan recursion depth in method body
4006
4007 public void check(JCClassDecl classDef) {
4008 scan(classDef.defs);
4009 }
4010
4011 @Override
4012 public void visitMethodDef(JCMethodDecl tree) {
4013 Assert.check(!constructor);
4014 Assert.check(earlyReturn == null);
4015 Assert.check(initCall == null);
4016 Assert.check(scanDepth == 1);
4017
4018 // Initialize state for this method
4019 constructor = TreeInfo.isConstructor(tree);
4020 try {
4021
4022 // Scan method body
4023 if (tree.body != null) {
4024 firstStatement = true;
4025 for (List<JCStatement> l = tree.body.stats; l.nonEmpty(); l = l.tail) {
4026 scan(l.head);
4027 firstStatement = false;
4028 }
4029 }
4030
4031 // Verify no 'return' seen prior to an explicit super()/this() call
4032 if (constructor && earlyReturn != null && initCall != null)
4033 log.error(earlyReturn.pos(), Errors.ReturnBeforeSuperclassInitialized);
4034 } finally {
4035 firstStatement = false;
4036 constructor = false;
4037 earlyReturn = null;
4038 initCall = null;
4039 }
4040 }
4041
4042 @Override
4043 public void scan(JCTree tree) {
4044 scanDepth++;
4045 try {
4046 super.scan(tree);
4047 } finally {
4048 scanDepth--;
4049 }
4050 }
4051
4052 @Override
4053 public void visitApply(JCMethodInvocation apply) {
4054 do {
4055
4056 // Is this a super() or this() call?
4057 Name methodName = TreeInfo.name(apply.meth);
4058 if (methodName != names._super && methodName != names._this)
4059 break;
4060
4061 // super()/this() calls must only appear in a constructor
4062 if (!constructor) {
4063 log.error(apply.pos(), Errors.CallMustOnlyAppearInCtor);
4064 break;
4065 }
4066
4067 // super()/this() calls must be a top level statement
4068 if (scanDepth != MATCH_SCAN_DEPTH) {
4069 log.error(apply.pos(), Errors.CtorCallsNotAllowedHere);
4070 break;
4071 }
4072
4073 // super()/this() calls must not appear more than once
4074 if (initCall != null) {
4075 log.error(apply.pos(), Errors.RedundantSuperclassInit);
4076 break;
4077 }
4078
4079 // If super()/this() isn't first, require flexible constructors feature
4080 if (!firstStatement)
4081 preview.checkSourceLevel(apply.pos(), Feature.FLEXIBLE_CONSTRUCTORS);
4082
4083 // We found a legitimate super()/this() call; remember it
4084 initCall = methodName;
4085 } while (false);
4086
4087 // Proceed
4088 super.visitApply(apply);
4089 }
4090
4091 @Override
4092 public void visitReturn(JCReturn tree) {
4093 if (constructor && initCall == null && earlyReturn == null)
4094 earlyReturn = tree; // we have seen a return but not (yet) a super()/this()
4095 super.visitReturn(tree);
4096 }
4097
4098 @Override
4099 public void visitClassDef(JCClassDecl tree) {
4100 // don't descend any further
4101 }
4102
4103 @Override
4104 public void visitLambda(JCLambda tree) {
4105 final boolean constructorPrev = constructor;
4106 final boolean firstStatementPrev = firstStatement;
4107 final JCReturn earlyReturnPrev = earlyReturn;
4108 final Name initCallPrev = initCall;
4109 final int scanDepthPrev = scanDepth;
4110 constructor = false;
4111 firstStatement = false;
4112 earlyReturn = null;
4113 initCall = null;
4114 scanDepth = 0;
4115 try {
4116 super.visitLambda(tree);
4117 } finally {
4118 constructor = constructorPrev;
4119 firstStatement = firstStatementPrev;
4120 earlyReturn = earlyReturnPrev;
4121 initCall = initCallPrev;
4122 scanDepth = scanDepthPrev;
4123 }
4124 }
4125 }
4126
4127 /* *************************************************************************
4128 * Miscellaneous
4129 **************************************************************************/
4130
4131 /**
4132 * Check for division by integer constant zero
4133 * @param pos Position for error reporting.
4134 * @param operator The operator for the expression
4135 * @param operand The right hand operand for the expression
4136 */
4137 void checkDivZero(final DiagnosticPosition pos, Symbol operator, Type operand) {
4138 if (operand.constValue() != null
4139 && operand.getTag().isSubRangeOf(LONG)
4140 && ((Number) (operand.constValue())).longValue() == 0) {
4141 int opc = ((OperatorSymbol)operator).opcode;
4142 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
4143 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
4144 log.warning(pos, LintWarnings.DivZero);
4145 }
4146 }
4147 }
4148
4149 /**
4150 * Check for possible loss of precission
4151 * @param pos Position for error reporting.
4152 * @param found The computed type of the tree
4153 * @param req The computed type of the tree
4154 */
4155 void checkLossOfPrecision(final DiagnosticPosition pos, Type found, Type req) {
4156 if (found.isNumeric() && req.isNumeric() && !types.isAssignable(found, req)) {
4157 log.warning(pos, LintWarnings.PossibleLossOfPrecision(found, req));
4158 }
4159 }
4160
4161 /**
4162 * Check for empty statements after if
4163 */
4164 void checkEmptyIf(JCIf tree) {
4165 if (tree.thenpart.hasTag(SKIP) && tree.elsepart == null) {
4166 log.warning(tree.thenpart.pos(), LintWarnings.EmptyIf);
4167 }
4168 }
4169
4170 /** Check that symbol is unique in given scope.
4171 * @param pos Position for error reporting.
4172 * @param sym The symbol.
4173 * @param s The scope.
4174 */
4175 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
4176 if (sym.type.isErroneous())
4177 return true;
4178 if (sym.owner.name == names.any) return false;
4179 for (Symbol byName : s.getSymbolsByName(sym.name, NON_RECURSIVE)) {
4180 if (sym != byName &&
4181 (byName.flags() & CLASH) == 0 &&
4182 sym.kind == byName.kind &&
4183 sym.name != names.error &&
4184 (sym.kind != MTH ||
4185 types.hasSameArgs(sym.type, byName.type) ||
4186 types.hasSameArgs(types.erasure(sym.type), types.erasure(byName.type)))) {
4187 if ((sym.flags() & VARARGS) != (byName.flags() & VARARGS)) {
4188 sym.flags_field |= CLASH;
4189 varargsDuplicateError(pos, sym, byName);
4190 return true;
4191 } else if (sym.kind == MTH && !types.hasSameArgs(sym.type, byName.type, false)) {
4192 duplicateErasureError(pos, sym, byName);
4193 sym.flags_field |= CLASH;
4194 return true;
4195 } else if ((sym.flags() & MATCH_BINDING) != 0 &&
4196 (byName.flags() & MATCH_BINDING) != 0 &&
4197 (byName.flags() & MATCH_BINDING_TO_OUTER) == 0) {
4198 if (!sym.type.isErroneous()) {
4199 log.error(pos, Errors.MatchBindingExists);
4200 sym.flags_field |= CLASH;
4201 }
4202 return false;
4203 } else {
4204 duplicateError(pos, byName);
4205 return false;
4206 }
4207 }
4208 }
4209 return true;
4210 }
4211
4212 /** Report duplicate declaration error.
4213 */
4214 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
4215 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
4216 log.error(pos, Errors.NameClashSameErasure(sym1, sym2));
4217 }
4218 }
4219
4220 /**Check that types imported through the ordinary imports don't clash with types imported
4221 * by other (static or ordinary) imports. Note that two static imports may import two clashing
4222 * types without an error on the imports.
4223 * @param toplevel The toplevel tree for which the test should be performed.
4224 */
4225 void checkImportsUnique(JCCompilationUnit toplevel) {
4226 WriteableScope ordinallyImportedSoFar = WriteableScope.create(toplevel.packge);
4227 WriteableScope staticallyImportedSoFar = WriteableScope.create(toplevel.packge);
4228 WriteableScope topLevelScope = toplevel.toplevelScope;
4229
4230 for (JCTree def : toplevel.defs) {
4231 if (!def.hasTag(IMPORT))
4232 continue;
4233
4234 JCImport imp = (JCImport) def;
4235
4236 if (imp.importScope == null)
4237 continue;
4238
4239 for (Symbol sym : imp.importScope.getSymbols(sym -> sym.kind == TYP)) {
4240 if (imp.isStatic()) {
4241 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, true);
4242 staticallyImportedSoFar.enter(sym);
4243 } else {
4244 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, false);
4245 ordinallyImportedSoFar.enter(sym);
4246 }
4247 }
4248
4249 imp.importScope = null;
4250 }
4251 }
4252
4253 /** Check that single-type import is not already imported or top-level defined,
4254 * but make an exception for two single-type imports which denote the same type.
4255 * @param pos Position for error reporting.
4256 * @param ordinallyImportedSoFar A Scope containing types imported so far through
4257 * ordinary imports.
4258 * @param staticallyImportedSoFar A Scope containing types imported so far through
4259 * static imports.
4260 * @param topLevelScope The current file's top-level Scope
4261 * @param sym The symbol.
4262 * @param staticImport Whether or not this was a static import
4263 */
4264 private boolean checkUniqueImport(DiagnosticPosition pos, Scope ordinallyImportedSoFar,
4265 Scope staticallyImportedSoFar, Scope topLevelScope,
4266 Symbol sym, boolean staticImport) {
4267 Predicate<Symbol> duplicates = candidate -> candidate != sym && !candidate.type.isErroneous();
4268 Symbol ordinaryClashing = ordinallyImportedSoFar.findFirst(sym.name, duplicates);
4269 Symbol staticClashing = null;
4270 if (ordinaryClashing == null && !staticImport) {
4271 staticClashing = staticallyImportedSoFar.findFirst(sym.name, duplicates);
4272 }
4273 if (ordinaryClashing != null || staticClashing != null) {
4274 if (ordinaryClashing != null)
4275 log.error(pos, Errors.AlreadyDefinedSingleImport(ordinaryClashing));
4276 else
4277 log.error(pos, Errors.AlreadyDefinedStaticSingleImport(staticClashing));
4278 return false;
4279 }
4280 Symbol clashing = topLevelScope.findFirst(sym.name, duplicates);
4281 if (clashing != null) {
4282 log.error(pos, Errors.AlreadyDefinedThisUnit(clashing));
4283 return false;
4284 }
4285 return true;
4286 }
4287
4288 /** Check that a qualified name is in canonical form (for import decls).
4289 */
4290 public void checkCanonical(JCTree tree) {
4291 if (!isCanonical(tree))
4292 log.error(tree.pos(),
4293 Errors.ImportRequiresCanonical(TreeInfo.symbol(tree)));
4294 }
4295 // where
4296 private boolean isCanonical(JCTree tree) {
4297 while (tree.hasTag(SELECT)) {
4298 JCFieldAccess s = (JCFieldAccess) tree;
4299 if (s.sym.owner.getQualifiedName() != TreeInfo.symbol(s.selected).getQualifiedName())
4300 return false;
4301 tree = s.selected;
4302 }
4303 return true;
4304 }
4305
4306 /** Check that an auxiliary class is not accessed from any other file than its own.
4307 */
4308 void checkForBadAuxiliaryClassAccess(DiagnosticPosition pos, Env<AttrContext> env, ClassSymbol c) {
4309 if ((c.flags() & AUXILIARY) != 0 &&
4310 rs.isAccessible(env, c) &&
4311 !fileManager.isSameFile(c.sourcefile, env.toplevel.sourcefile))
4312 {
4313 log.warning(pos, LintWarnings.AuxiliaryClassAccessedFromOutsideOfItsSourceFile(c, c.sourcefile));
4314 }
4315 }
4316
4317 /**
4318 * Check for a default constructor in an exported package.
4319 */
4320 void checkDefaultConstructor(ClassSymbol c, DiagnosticPosition pos) {
4321 if (lint.isEnabled(LintCategory.MISSING_EXPLICIT_CTOR) &&
4322 ((c.flags() & (ENUM | RECORD)) == 0) &&
4323 !c.isAnonymous() &&
4324 ((c.flags() & (PUBLIC | PROTECTED)) != 0) &&
4325 Feature.MODULES.allowedInSource(source)) {
4326 NestingKind nestingKind = c.getNestingKind();
4327 switch (nestingKind) {
4328 case ANONYMOUS,
4329 LOCAL -> {return;}
4330 case TOP_LEVEL -> {;} // No additional checks needed
4331 case MEMBER -> {
4332 // For nested member classes, all the enclosing
4333 // classes must be public or protected.
4334 Symbol owner = c.owner;
4335 while (owner != null && owner.kind == TYP) {
4336 if ((owner.flags() & (PUBLIC | PROTECTED)) == 0)
4337 return;
4338 owner = owner.owner;
4339 }
4340 }
4341 }
4342
4343 // Only check classes in named packages exported by its module
4344 PackageSymbol pkg = c.packge();
4345 if (!pkg.isUnnamed()) {
4346 ModuleSymbol modle = pkg.modle;
4347 for (ExportsDirective exportDir : modle.exports) {
4348 // Report warning only if the containing
4349 // package is unconditionally exported
4350 if (exportDir.packge.equals(pkg)) {
4351 if (exportDir.modules == null || exportDir.modules.isEmpty()) {
4352 // Warning may be suppressed by
4353 // annotations; check again for being
4354 // enabled in the deferred context.
4355 log.warning(pos, LintWarnings.MissingExplicitCtor(c, pkg, modle));
4356 } else {
4357 return;
4358 }
4359 }
4360 }
4361 }
4362 }
4363 return;
4364 }
4365
4366 private class ConversionWarner extends Warner {
4367 final String uncheckedKey;
4368 final Type found;
4369 final Type expected;
4370 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
4371 super(pos);
4372 this.uncheckedKey = uncheckedKey;
4373 this.found = found;
4374 this.expected = expected;
4375 }
4376
4377 @Override
4378 public void warn(LintCategory lint) {
4379 boolean warned = this.warned;
4380 super.warn(lint);
4381 if (warned) return; // suppress redundant diagnostics
4382 switch (lint) {
4383 case UNCHECKED:
4384 Check.this.warnUnchecked(pos(), LintWarnings.ProbFoundReq(diags.fragment(uncheckedKey), found, expected));
4385 break;
4386 case VARARGS:
4387 if (method != null &&
4388 method.attribute(syms.trustMeType.tsym) != null &&
4389 isTrustMeAllowedOnMethod(method) &&
4390 !types.isReifiable(method.type.getParameterTypes().last())) {
4391 log.warning(pos(), LintWarnings.VarargsUnsafeUseVarargsParam(method.params.last()));
4392 }
4393 break;
4394 default:
4395 throw new AssertionError("Unexpected lint: " + lint);
4396 }
4397 }
4398 }
4399
4400 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
4401 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
4402 }
4403
4404 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
4405 return new ConversionWarner(pos, "unchecked.assign", found, expected);
4406 }
4407
4408 public void checkFunctionalInterface(JCClassDecl tree, ClassSymbol cs) {
4409 Compound functionalType = cs.attribute(syms.functionalInterfaceType.tsym);
4410
4411 if (functionalType != null) {
4412 try {
4413 types.findDescriptorSymbol((TypeSymbol)cs);
4414 } catch (Types.FunctionDescriptorLookupError ex) {
4415 DiagnosticPosition pos = tree.pos();
4416 for (JCAnnotation a : tree.getModifiers().annotations) {
4417 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
4418 pos = a.pos();
4419 break;
4420 }
4421 }
4422 log.error(pos, Errors.BadFunctionalIntfAnno1(ex.getDiagnostic()));
4423 }
4424 }
4425 }
4426
4427 public void checkImportsResolvable(final JCCompilationUnit toplevel) {
4428 for (final JCImportBase impBase : toplevel.getImports()) {
4429 if (!(impBase instanceof JCImport imp))
4430 continue;
4431 if (!imp.staticImport || !imp.qualid.hasTag(SELECT))
4432 continue;
4433 final JCFieldAccess select = imp.qualid;
4434 final Symbol origin;
4435 if (select.name == names.asterisk || (origin = TreeInfo.symbol(select.selected)) == null || origin.kind != TYP)
4436 continue;
4437
4438 TypeSymbol site = (TypeSymbol) TreeInfo.symbol(select.selected);
4439 if (!checkTypeContainsImportableElement(site, site, toplevel.packge, select.name, new HashSet<Symbol>())) {
4440 log.error(imp.pos(),
4441 Errors.CantResolveLocation(KindName.STATIC,
4442 select.name,
4443 null,
4444 null,
4445 Fragments.Location(kindName(site),
4446 site,
4447 null)));
4448 }
4449 }
4450 }
4451
4452 // Check that packages imported are in scope (JLS 7.4.3, 6.3, 6.5.3.1, 6.5.3.2)
4453 public void checkImportedPackagesObservable(final JCCompilationUnit toplevel) {
4454 OUTER: for (JCImportBase impBase : toplevel.getImports()) {
4455 if (impBase instanceof JCImport imp && !imp.staticImport &&
4456 TreeInfo.name(imp.qualid) == names.asterisk) {
4457 TypeSymbol tsym = imp.qualid.selected.type.tsym;
4458 if (tsym.kind == PCK && tsym.members().isEmpty() &&
4459 !(Feature.IMPORT_ON_DEMAND_OBSERVABLE_PACKAGES.allowedInSource(source) && tsym.exists())) {
4460 log.error(DiagnosticFlag.RESOLVE_ERROR, imp.qualid.selected.pos(), Errors.DoesntExist(tsym));
4461 }
4462 }
4463 }
4464 }
4465
4466 private boolean checkTypeContainsImportableElement(TypeSymbol tsym, TypeSymbol origin, PackageSymbol packge, Name name, Set<Symbol> processed) {
4467 if (tsym == null || !processed.add(tsym))
4468 return false;
4469
4470 // also search through inherited names
4471 if (checkTypeContainsImportableElement(types.supertype(tsym.type).tsym, origin, packge, name, processed))
4472 return true;
4473
4474 for (Type t : types.interfaces(tsym.type))
4475 if (checkTypeContainsImportableElement(t.tsym, origin, packge, name, processed))
4476 return true;
4477
4478 for (Symbol sym : tsym.members().getSymbolsByName(name)) {
4479 if (sym.isStatic() &&
4480 importAccessible(sym, packge) &&
4481 sym.isMemberOf(origin, types)) {
4482 return true;
4483 }
4484 }
4485
4486 return false;
4487 }
4488
4489 // is the sym accessible everywhere in packge?
4490 public boolean importAccessible(Symbol sym, PackageSymbol packge) {
4491 try {
4492 int flags = (int)(sym.flags() & AccessFlags);
4493 switch (flags) {
4494 default:
4495 case PUBLIC:
4496 return true;
4497 case PRIVATE:
4498 return false;
4499 case 0:
4500 case PROTECTED:
4501 return sym.packge() == packge;
4502 }
4503 } catch (ClassFinder.BadClassFile err) {
4504 throw err;
4505 } catch (CompletionFailure ex) {
4506 return false;
4507 }
4508 }
4509
4510 public void checkLeaksNotAccessible(Env<AttrContext> env, JCClassDecl check) {
4511 JCCompilationUnit toplevel = env.toplevel;
4512
4513 if ( toplevel.modle == syms.unnamedModule
4514 || toplevel.modle == syms.noModule
4515 || (check.sym.flags() & COMPOUND) != 0) {
4516 return ;
4517 }
4518
4519 ExportsDirective currentExport = findExport(toplevel.packge);
4520
4521 if ( currentExport == null //not exported
4522 || currentExport.modules != null) //don't check classes in qualified export
4523 return ;
4524
4525 new TreeScanner() {
4526 Lint lint = env.info.lint;
4527 boolean inSuperType;
4528
4529 @Override
4530 public void visitBlock(JCBlock tree) {
4531 }
4532 @Override
4533 public void visitMethodDef(JCMethodDecl tree) {
4534 if (!isAPISymbol(tree.sym))
4535 return;
4536 Lint prevLint = lint;
4537 try {
4538 lint = lint.augment(tree.sym);
4539 if (lint.isEnabled(LintCategory.EXPORTS)) {
4540 super.visitMethodDef(tree);
4541 }
4542 } finally {
4543 lint = prevLint;
4544 }
4545 }
4546 @Override
4547 public void visitVarDef(JCVariableDecl tree) {
4548 if (!isAPISymbol(tree.sym) && tree.sym.owner.kind != MTH)
4549 return;
4550 Lint prevLint = lint;
4551 try {
4552 lint = lint.augment(tree.sym);
4553 if (lint.isEnabled(LintCategory.EXPORTS)) {
4554 scan(tree.mods);
4555 scan(tree.vartype);
4556 }
4557 } finally {
4558 lint = prevLint;
4559 }
4560 }
4561 @Override
4562 public void visitClassDef(JCClassDecl tree) {
4563 if (tree != check)
4564 return ;
4565
4566 if (!isAPISymbol(tree.sym))
4567 return ;
4568
4569 Lint prevLint = lint;
4570 try {
4571 lint = lint.augment(tree.sym);
4572 if (lint.isEnabled(LintCategory.EXPORTS)) {
4573 scan(tree.mods);
4574 scan(tree.typarams);
4575 try {
4576 inSuperType = true;
4577 scan(tree.extending);
4578 scan(tree.implementing);
4579 } finally {
4580 inSuperType = false;
4581 }
4582 scan(tree.defs);
4583 }
4584 } finally {
4585 lint = prevLint;
4586 }
4587 }
4588 @Override
4589 public void visitTypeApply(JCTypeApply tree) {
4590 scan(tree.clazz);
4591 boolean oldInSuperType = inSuperType;
4592 try {
4593 inSuperType = false;
4594 scan(tree.arguments);
4595 } finally {
4596 inSuperType = oldInSuperType;
4597 }
4598 }
4599 @Override
4600 public void visitIdent(JCIdent tree) {
4601 Symbol sym = TreeInfo.symbol(tree);
4602 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR)) {
4603 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4604 }
4605 }
4606
4607 @Override
4608 public void visitSelect(JCFieldAccess tree) {
4609 Symbol sym = TreeInfo.symbol(tree);
4610 Symbol sitesym = TreeInfo.symbol(tree.selected);
4611 if (sym.kind == TYP && sitesym.kind == PCK) {
4612 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4613 } else {
4614 super.visitSelect(tree);
4615 }
4616 }
4617
4618 @Override
4619 public void visitAnnotation(JCAnnotation tree) {
4620 if (tree.attribute.type.tsym.getAnnotation(java.lang.annotation.Documented.class) != null)
4621 super.visitAnnotation(tree);
4622 }
4623
4624 }.scan(check);
4625 }
4626 //where:
4627 private ExportsDirective findExport(PackageSymbol pack) {
4628 for (ExportsDirective d : pack.modle.exports) {
4629 if (d.packge == pack)
4630 return d;
4631 }
4632
4633 return null;
4634 }
4635 private boolean isAPISymbol(Symbol sym) {
4636 while (sym.kind != PCK) {
4637 if ((sym.flags() & Flags.PUBLIC) == 0 && (sym.flags() & Flags.PROTECTED) == 0) {
4638 return false;
4639 }
4640 sym = sym.owner;
4641 }
4642 return true;
4643 }
4644 private void checkVisible(DiagnosticPosition pos, Symbol what, PackageSymbol inPackage, boolean inSuperType) {
4645 if (!isAPISymbol(what) && !inSuperType) { //package private/private element
4646 log.warning(pos, LintWarnings.LeaksNotAccessible(kindName(what), what, what.packge().modle));
4647 return ;
4648 }
4649
4650 PackageSymbol whatPackage = what.packge();
4651 ExportsDirective whatExport = findExport(whatPackage);
4652 ExportsDirective inExport = findExport(inPackage);
4653
4654 if (whatExport == null) { //package not exported:
4655 log.warning(pos, LintWarnings.LeaksNotAccessibleUnexported(kindName(what), what, what.packge().modle));
4656 return ;
4657 }
4658
4659 if (whatExport.modules != null) {
4660 if (inExport.modules == null || !whatExport.modules.containsAll(inExport.modules)) {
4661 log.warning(pos, LintWarnings.LeaksNotAccessibleUnexportedQualified(kindName(what), what, what.packge().modle));
4662 }
4663 }
4664
4665 if (whatPackage.modle != inPackage.modle && whatPackage.modle != syms.java_base) {
4666 //check that relativeTo.modle requires transitive what.modle, somehow:
4667 List<ModuleSymbol> todo = List.of(inPackage.modle);
4668
4669 while (todo.nonEmpty()) {
4670 ModuleSymbol current = todo.head;
4671 todo = todo.tail;
4672 if (current == whatPackage.modle)
4673 return ; //OK
4674 if ((current.flags() & Flags.AUTOMATIC_MODULE) != 0)
4675 continue; //for automatic modules, don't look into their dependencies
4676 for (RequiresDirective req : current.requires) {
4677 if (req.isTransitive()) {
4678 todo = todo.prepend(req.module);
4679 }
4680 }
4681 }
4682
4683 log.warning(pos, LintWarnings.LeaksNotAccessibleNotRequiredTransitive(kindName(what), what, what.packge().modle));
4684 }
4685 }
4686
4687 void checkModuleExists(final DiagnosticPosition pos, ModuleSymbol msym) {
4688 if (msym.kind != MDL) {
4689 log.warning(pos, LintWarnings.ModuleNotFound(msym));
4690 }
4691 }
4692
4693 void checkPackageExistsForOpens(final DiagnosticPosition pos, PackageSymbol packge) {
4694 if (packge.members().isEmpty() &&
4695 ((packge.flags() & Flags.HAS_RESOURCE) == 0)) {
4696 log.warning(pos, LintWarnings.PackageEmptyOrNotFound(packge));
4697 }
4698 }
4699
4700 void checkModuleRequires(final DiagnosticPosition pos, final RequiresDirective rd) {
4701 if ((rd.module.flags() & Flags.AUTOMATIC_MODULE) != 0) {
4702 if (rd.isTransitive()) { // see comment in Log.applyLint() for special logic that applies
4703 log.warning(pos, LintWarnings.RequiresTransitiveAutomatic);
4704 } else {
4705 log.warning(pos, LintWarnings.RequiresAutomatic);
4706 }
4707 }
4708 }
4709
4710 /**
4711 * Verify the case labels conform to the constraints. Checks constraints related
4712 * combinations of patterns and other labels.
4713 *
4714 * @param cases the cases that should be checked.
4715 */
4716 void checkSwitchCaseStructure(List<JCCase> cases) {
4717 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4718 JCCase c = l.head;
4719 if (c.labels.head instanceof JCConstantCaseLabel constLabel) {
4720 if (TreeInfo.isNull(constLabel.expr)) {
4721 if (c.labels.tail.nonEmpty()) {
4722 if (c.labels.tail.head instanceof JCDefaultCaseLabel defLabel) {
4723 if (c.labels.tail.tail.nonEmpty()) {
4724 log.error(c.labels.tail.tail.head.pos(), Errors.InvalidCaseLabelCombination);
4725 }
4726 } else {
4727 log.error(c.labels.tail.head.pos(), Errors.InvalidCaseLabelCombination);
4728 }
4729 }
4730 } else {
4731 for (JCCaseLabel label : c.labels.tail) {
4732 if (!(label instanceof JCConstantCaseLabel) || TreeInfo.isNullCaseLabel(label)) {
4733 log.error(label.pos(), Errors.InvalidCaseLabelCombination);
4734 break;
4735 }
4736 }
4737 }
4738 } else if (c.labels.tail.nonEmpty()) {
4739 var patterCaseLabels = c.labels.stream().filter(ll -> ll instanceof JCPatternCaseLabel).map(cl -> (JCPatternCaseLabel)cl);
4740 var allUnderscore = patterCaseLabels.allMatch(pcl -> !hasBindings(pcl.getPattern()));
4741
4742 if (!allUnderscore) {
4743 log.error(c.labels.tail.head.pos(), Errors.FlowsThroughFromPattern);
4744 }
4745
4746 boolean allPatternCaseLabels = c.labels.stream().allMatch(p -> p instanceof JCPatternCaseLabel);
4747
4748 if (allPatternCaseLabels) {
4749 preview.checkSourceLevel(c.labels.tail.head.pos(), Feature.UNNAMED_VARIABLES);
4750 }
4751
4752 for (JCCaseLabel label : c.labels.tail) {
4753 if (label instanceof JCConstantCaseLabel) {
4754 log.error(label.pos(), Errors.InvalidCaseLabelCombination);
4755 break;
4756 }
4757 }
4758 }
4759 }
4760
4761 boolean isCaseStatementGroup = cases.nonEmpty() &&
4762 cases.head.caseKind == CaseTree.CaseKind.STATEMENT;
4763
4764 if (isCaseStatementGroup) {
4765 boolean previousCompletessNormally = false;
4766 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4767 JCCase c = l.head;
4768 if (previousCompletessNormally &&
4769 c.stats.nonEmpty() &&
4770 c.labels.head instanceof JCPatternCaseLabel patternLabel &&
4771 (hasBindings(patternLabel.pat) || hasBindings(c.guard))) {
4772 log.error(c.labels.head.pos(), Errors.FlowsThroughToPattern);
4773 } else if (c.stats.isEmpty() &&
4774 c.labels.head instanceof JCPatternCaseLabel patternLabel &&
4775 (hasBindings(patternLabel.pat) || hasBindings(c.guard)) &&
4776 hasStatements(l.tail)) {
4777 log.error(c.labels.head.pos(), Errors.FlowsThroughFromPattern);
4778 }
4779 previousCompletessNormally = c.completesNormally;
4780 }
4781 }
4782 }
4783
4784 boolean hasBindings(JCTree p) {
4785 boolean[] bindings = new boolean[1];
4786
4787 new TreeScanner() {
4788 @Override
4789 public void visitBindingPattern(JCBindingPattern tree) {
4790 bindings[0] |= !tree.var.sym.isUnnamedVariable();
4791 super.visitBindingPattern(tree);
4792 }
4793 }.scan(p);
4794
4795 return bindings[0];
4796 }
4797
4798 boolean hasStatements(List<JCCase> cases) {
4799 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4800 if (l.head.stats.nonEmpty()) {
4801 return true;
4802 }
4803 }
4804
4805 return false;
4806 }
4807 void checkSwitchCaseLabelDominated(JCCaseLabel unconditionalCaseLabel, List<JCCase> cases) {
4808 List<Pair<JCCase, JCCaseLabel>> caseLabels = List.nil();
4809 boolean seenDefault = false;
4810 boolean seenDefaultLabel = false;
4811 boolean warnDominatedByDefault = false;
4812 boolean unconditionalFound = false;
4813
4814 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4815 JCCase c = l.head;
4816 for (JCCaseLabel label : c.labels) {
4817 if (label.hasTag(DEFAULTCASELABEL)) {
4818 seenDefault = true;
4819 seenDefaultLabel |=
4820 TreeInfo.isNullCaseLabel(c.labels.head);
4821 continue;
4822 }
4823 if (TreeInfo.isNullCaseLabel(label)) {
4824 if (seenDefault) {
4825 log.error(label.pos(), Errors.PatternDominated);
4826 }
4827 continue;
4828 }
4829 if (seenDefault && !warnDominatedByDefault) {
4830 if (label.hasTag(PATTERNCASELABEL) ||
4831 (label instanceof JCConstantCaseLabel && seenDefaultLabel)) {
4832 log.error(label.pos(), Errors.PatternDominated);
4833 warnDominatedByDefault = true;
4834 }
4835 }
4836 Type currentType = labelType(label);
4837 for (Pair<JCCase, JCCaseLabel> caseAndLabel : caseLabels) {
4838 JCCase testCase = caseAndLabel.fst;
4839 JCCaseLabel testCaseLabel = caseAndLabel.snd;
4840 Type testType = labelType(testCaseLabel);
4841 boolean dominated = false;
4842 if (types.isUnconditionallyExact(currentType, testType) &&
4843 !currentType.hasTag(ERROR) && !testType.hasTag(ERROR)) {
4844 //the current label is potentially dominated by the existing (test) label, check:
4845 if (label instanceof JCConstantCaseLabel) {
4846 dominated |= !(testCaseLabel instanceof JCConstantCaseLabel) &&
4847 TreeInfo.unguardedCase(testCase);
4848 } else if (label instanceof JCPatternCaseLabel patternCL &&
4849 testCaseLabel instanceof JCPatternCaseLabel testPatternCaseLabel &&
4850 (testCase.equals(c) || TreeInfo.unguardedCase(testCase))) {
4851 dominated = patternDominated(testPatternCaseLabel.pat,
4852 patternCL.pat);
4853 }
4854 }
4855
4856 if (dominated) {
4857 log.error(label.pos(), Errors.PatternDominated);
4858 }
4859 }
4860 caseLabels = caseLabels.prepend(Pair.of(c, label));
4861 }
4862 }
4863 }
4864 //where:
4865 private Type labelType(JCCaseLabel label) {
4866 return types.erasure(switch (label.getTag()) {
4867 case PATTERNCASELABEL -> ((JCPatternCaseLabel) label).pat.type;
4868 case CONSTANTCASELABEL -> ((JCConstantCaseLabel) label).expr.type;
4869 default -> throw Assert.error("Unexpected tree kind: " + label.getTag());
4870 });
4871 }
4872 private boolean patternDominated(JCPattern existingPattern, JCPattern currentPattern) {
4873 Type existingPatternType = types.erasure(existingPattern.type);
4874 Type currentPatternType = types.erasure(currentPattern.type);
4875 if (!types.isUnconditionallyExact(currentPatternType, existingPatternType)) {
4876 return false;
4877 }
4878 if (currentPattern instanceof JCBindingPattern ||
4879 currentPattern instanceof JCAnyPattern) {
4880 return existingPattern instanceof JCBindingPattern ||
4881 existingPattern instanceof JCAnyPattern;
4882 } else if (currentPattern instanceof JCRecordPattern currentRecordPattern) {
4883 if (existingPattern instanceof JCBindingPattern ||
4884 existingPattern instanceof JCAnyPattern) {
4885 return true;
4886 } else if (existingPattern instanceof JCRecordPattern existingRecordPattern) {
4887 List<JCPattern> existingNested = existingRecordPattern.nested;
4888 List<JCPattern> currentNested = currentRecordPattern.nested;
4889 if (existingNested.size() != currentNested.size()) {
4890 return false;
4891 }
4892 while (existingNested.nonEmpty()) {
4893 if (!patternDominated(existingNested.head, currentNested.head)) {
4894 return false;
4895 }
4896 existingNested = existingNested.tail;
4897 currentNested = currentNested.tail;
4898 }
4899 return true;
4900 } else {
4901 Assert.error("Unknown pattern: " + existingPattern.getTag());
4902 }
4903 } else {
4904 Assert.error("Unknown pattern: " + currentPattern.getTag());
4905 }
4906 return false;
4907 }
4908
4909 /** check if a type is a subtype of Externalizable, if that is available. */
4910 boolean isExternalizable(Type t) {
4911 try {
4912 syms.externalizableType.complete();
4913 } catch (CompletionFailure e) {
4914 return false;
4915 }
4916 return types.isSubtype(t, syms.externalizableType);
4917 }
4918
4919 /**
4920 * Check structure of serialization declarations.
4921 */
4922 public void checkSerialStructure(Env<AttrContext> env, JCClassDecl tree, ClassSymbol c) {
4923 (new SerialTypeVisitor(env)).visit(c, tree);
4924 }
4925
4926 /**
4927 * This visitor will warn if a serialization-related field or
4928 * method is declared in a suspicious or incorrect way. In
4929 * particular, it will warn for cases where the runtime
4930 * serialization mechanism will silently ignore a mis-declared
4931 * entity.
4932 *
4933 * Distinguished serialization-related fields and methods:
4934 *
4935 * Methods:
4936 *
4937 * private void writeObject(ObjectOutputStream stream) throws IOException
4938 * ANY-ACCESS-MODIFIER Object writeReplace() throws ObjectStreamException
4939 *
4940 * private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException
4941 * private void readObjectNoData() throws ObjectStreamException
4942 * ANY-ACCESS-MODIFIER Object readResolve() throws ObjectStreamException
4943 *
4944 * Fields:
4945 *
4946 * private static final long serialVersionUID
4947 * private static final ObjectStreamField[] serialPersistentFields
4948 *
4949 * Externalizable: methods defined on the interface
4950 * public void writeExternal(ObjectOutput) throws IOException
4951 * public void readExternal(ObjectInput) throws IOException
4952 */
4953 private class SerialTypeVisitor extends ElementKindVisitor14<Void, JCClassDecl> {
4954 Env<AttrContext> env;
4955 SerialTypeVisitor(Env<AttrContext> env) {
4956 this.lint = Check.this.lint;
4957 this.env = env;
4958 }
4959
4960 private static final Set<String> serialMethodNames =
4961 Set.of("writeObject", "writeReplace",
4962 "readObject", "readObjectNoData",
4963 "readResolve");
4964
4965 private static final Set<String> serialFieldNames =
4966 Set.of("serialVersionUID", "serialPersistentFields");
4967
4968 // Type of serialPersistentFields
4969 private final Type OSF_TYPE = new Type.ArrayType(syms.objectStreamFieldType, syms.arrayClass);
4970
4971 Lint lint;
4972
4973 @Override
4974 public Void defaultAction(Element e, JCClassDecl p) {
4975 throw new IllegalArgumentException(Objects.requireNonNullElse(e.toString(), ""));
4976 }
4977
4978 @Override
4979 public Void visitType(TypeElement e, JCClassDecl p) {
4980 runUnderLint(e, p, (symbol, param) -> super.visitType(symbol, param));
4981 return null;
4982 }
4983
4984 @Override
4985 public Void visitTypeAsClass(TypeElement e,
4986 JCClassDecl p) {
4987 // Anonymous classes filtered out by caller.
4988
4989 ClassSymbol c = (ClassSymbol)e;
4990
4991 checkCtorAccess(p, c);
4992
4993 // Check for missing serialVersionUID; check *not* done
4994 // for enums or records.
4995 VarSymbol svuidSym = null;
4996 for (Symbol sym : c.members().getSymbolsByName(names.serialVersionUID)) {
4997 if (sym.kind == VAR) {
4998 svuidSym = (VarSymbol)sym;
4999 break;
5000 }
5001 }
5002
5003 if (svuidSym == null) {
5004 log.warning(p.pos(), LintWarnings.MissingSVUID(c));
5005 }
5006
5007 // Check for serialPersistentFields to gate checks for
5008 // non-serializable non-transient instance fields
5009 boolean serialPersistentFieldsPresent =
5010 c.members()
5011 .getSymbolsByName(names.serialPersistentFields, sym -> sym.kind == VAR)
5012 .iterator()
5013 .hasNext();
5014
5015 // Check declarations of serialization-related methods and
5016 // fields
5017 final boolean[] hasWriteReplace = {false};
5018 for(Symbol el : c.getEnclosedElements()) {
5019 runUnderLint(el, p, (enclosed, tree) -> {
5020 String name = null;
5021 switch(enclosed.getKind()) {
5022 case FIELD -> {
5023 if (!serialPersistentFieldsPresent) {
5024 var flags = enclosed.flags();
5025 if ( ((flags & TRANSIENT) == 0) &&
5026 ((flags & STATIC) == 0)) {
5027 Type varType = enclosed.asType();
5028 if (!canBeSerialized(varType)) {
5029 // Note per JLS arrays are
5030 // serializable even if the
5031 // component type is not.
5032 log.warning(
5033 TreeInfo.diagnosticPositionFor(enclosed, tree),
5034 LintWarnings.NonSerializableInstanceField);
5035 } else if (varType.hasTag(ARRAY)) {
5036 ArrayType arrayType = (ArrayType)varType;
5037 Type elementType = arrayType.elemtype;
5038 while (elementType.hasTag(ARRAY)) {
5039 arrayType = (ArrayType)elementType;
5040 elementType = arrayType.elemtype;
5041 }
5042 if (!canBeSerialized(elementType)) {
5043 log.warning(
5044 TreeInfo.diagnosticPositionFor(enclosed, tree),
5045 LintWarnings.NonSerializableInstanceFieldArray(elementType));
5046 }
5047 }
5048 }
5049 }
5050
5051 name = enclosed.getSimpleName().toString();
5052 if (serialFieldNames.contains(name)) {
5053 VarSymbol field = (VarSymbol)enclosed;
5054 switch (name) {
5055 case "serialVersionUID" -> checkSerialVersionUID(tree, e, field);
5056 case "serialPersistentFields" -> checkSerialPersistentFields(tree, e, field);
5057 default -> throw new AssertionError();
5058 }
5059 }
5060 }
5061
5062 // Correctly checking the serialization-related
5063 // methods is subtle. For the methods declared to be
5064 // private or directly declared in the class, the
5065 // enclosed elements of the class can be checked in
5066 // turn. However, writeReplace and readResolve can be
5067 // declared in a superclass and inherited. Note that
5068 // the runtime lookup walks the superclass chain
5069 // looking for writeReplace/readResolve via
5070 // Class.getDeclaredMethod. This differs from calling
5071 // Elements.getAllMembers(TypeElement) as the latter
5072 // will also pull in default methods from
5073 // superinterfaces. In other words, the runtime checks
5074 // (which long predate default methods on interfaces)
5075 // do not admit the possibility of inheriting methods
5076 // this way, a difference from general inheritance.
5077
5078 // The current implementation just checks the enclosed
5079 // elements and does not directly check the inherited
5080 // methods. If all the types are being checked this is
5081 // less of a concern; however, there are cases that
5082 // could be missed. In particular, readResolve and
5083 // writeReplace could, in principle, by inherited from
5084 // a non-serializable superclass and thus not checked
5085 // even if compiled with a serializable child class.
5086 case METHOD -> {
5087 var method = (MethodSymbol)enclosed;
5088 name = method.getSimpleName().toString();
5089 if (serialMethodNames.contains(name)) {
5090 switch (name) {
5091 case "writeObject" -> checkWriteObject(tree, e, method);
5092 case "writeReplace" -> {hasWriteReplace[0] = true; hasAppropriateWriteReplace(tree, method, true);}
5093 case "readObject" -> checkReadObject(tree,e, method);
5094 case "readObjectNoData" -> checkReadObjectNoData(tree, e, method);
5095 case "readResolve" -> checkReadResolve(tree, e, method);
5096 default -> throw new AssertionError();
5097 }
5098 }
5099 }
5100 }
5101 });
5102 }
5103 if (!hasWriteReplace[0] &&
5104 (c.isValueClass() || hasAbstractValueSuperClass(c, Set.of(syms.numberType.tsym))) &&
5105 !c.isAbstract() && !c.isRecord() &&
5106 types.unboxedType(c.type) == Type.noType) {
5107 // we need to check if the class is inheriting an appropriate writeReplace method
5108 MethodSymbol ms = null;
5109 Log.DiagnosticHandler discardHandler = log.new DiscardDiagnosticHandler();
5110 try {
5111 ms = rs.resolveInternalMethod(env.tree, env, c.type, names.writeReplace, List.nil(), List.nil());
5112 } catch (FatalError fe) {
5113 // ignore no method was found
5114 } finally {
5115 log.popDiagnosticHandler(discardHandler);
5116 }
5117 if (ms == null || !hasAppropriateWriteReplace(p, ms, false)) {
5118 log.warning(p.pos(),
5119 c.isValueClass() ? LintWarnings.SerializableValueClassWithoutWriteReplace1 :
5120 LintWarnings.SerializableValueClassWithoutWriteReplace2);
5121 }
5122 }
5123 return null;
5124 }
5125
5126 boolean canBeSerialized(Type type) {
5127 return type.isPrimitive() || rs.isSerializable(type);
5128 }
5129
5130 private boolean hasAbstractValueSuperClass(Symbol c, Set<Symbol> excluding) {
5131 while (c.getKind() == ElementKind.CLASS) {
5132 Type sup = ((ClassSymbol)c).getSuperclass();
5133 if (!sup.hasTag(CLASS) || sup.isErroneous() ||
5134 sup.tsym == syms.objectType.tsym) {
5135 return false;
5136 }
5137 // if it is a value super class it has to be abstract
5138 if (sup.isValueClass() && !excluding.contains(sup.tsym)) {
5139 return true;
5140 }
5141 c = sup.tsym;
5142 }
5143 return false;
5144 }
5145
5146 /**
5147 * Check that Externalizable class needs a public no-arg
5148 * constructor.
5149 *
5150 * Check that a Serializable class has access to the no-arg
5151 * constructor of its first nonserializable superclass.
5152 */
5153 private void checkCtorAccess(JCClassDecl tree, ClassSymbol c) {
5154 if (isExternalizable(c.type)) {
5155 for(var sym : c.getEnclosedElements()) {
5156 if (sym.isConstructor() &&
5157 ((sym.flags() & PUBLIC) == PUBLIC)) {
5158 if (((MethodSymbol)sym).getParameters().isEmpty()) {
5159 return;
5160 }
5161 }
5162 }
5163 log.warning(tree.pos(),
5164 LintWarnings.ExternalizableMissingPublicNoArgCtor);
5165 } else {
5166 // Approximate access to the no-arg constructor up in
5167 // the superclass chain by checking that the
5168 // constructor is not private. This may not handle
5169 // some cross-package situations correctly.
5170 Type superClass = c.getSuperclass();
5171 // java.lang.Object is *not* Serializable so this loop
5172 // should terminate.
5173 while (rs.isSerializable(superClass) ) {
5174 try {
5175 superClass = (Type)((TypeElement)(((DeclaredType)superClass)).asElement()).getSuperclass();
5176 } catch(ClassCastException cce) {
5177 return ; // Don't try to recover
5178 }
5179 }
5180 // Non-Serializable superclass
5181 try {
5182 ClassSymbol supertype = ((ClassSymbol)(((DeclaredType)superClass).asElement()));
5183 for(var sym : supertype.getEnclosedElements()) {
5184 if (sym.isConstructor()) {
5185 MethodSymbol ctor = (MethodSymbol)sym;
5186 if (ctor.getParameters().isEmpty()) {
5187 if (((ctor.flags() & PRIVATE) == PRIVATE) ||
5188 // Handle nested classes and implicit this$0
5189 (supertype.getNestingKind() == NestingKind.MEMBER &&
5190 ((supertype.flags() & STATIC) == 0)))
5191 log.warning(tree.pos(),
5192 LintWarnings.SerializableMissingAccessNoArgCtor(supertype.getQualifiedName()));
5193 }
5194 }
5195 }
5196 } catch (ClassCastException cce) {
5197 return ; // Don't try to recover
5198 }
5199 return;
5200 }
5201 }
5202
5203 private void checkSerialVersionUID(JCClassDecl tree, Element e, VarSymbol svuid) {
5204 // To be effective, serialVersionUID must be marked static
5205 // and final, but private is recommended. But alas, in
5206 // practice there are many non-private serialVersionUID
5207 // fields.
5208 if ((svuid.flags() & (STATIC | FINAL)) !=
5209 (STATIC | FINAL)) {
5210 log.warning(
5211 TreeInfo.diagnosticPositionFor(svuid, tree),
5212 LintWarnings.ImproperSVUID((Symbol)e));
5213 }
5214
5215 // check svuid has type long
5216 if (!svuid.type.hasTag(LONG)) {
5217 log.warning(
5218 TreeInfo.diagnosticPositionFor(svuid, tree),
5219 LintWarnings.LongSVUID((Symbol)e));
5220 }
5221
5222 if (svuid.getConstValue() == null)
5223 log.warning(
5224 TreeInfo.diagnosticPositionFor(svuid, tree),
5225 LintWarnings.ConstantSVUID((Symbol)e));
5226 }
5227
5228 private void checkSerialPersistentFields(JCClassDecl tree, Element e, VarSymbol spf) {
5229 // To be effective, serialPersisentFields must be private, static, and final.
5230 if ((spf.flags() & (PRIVATE | STATIC | FINAL)) !=
5231 (PRIVATE | STATIC | FINAL)) {
5232 log.warning(
5233 TreeInfo.diagnosticPositionFor(spf, tree),
5234 LintWarnings.ImproperSPF);
5235 }
5236
5237 if (!types.isSameType(spf.type, OSF_TYPE)) {
5238 log.warning(
5239 TreeInfo.diagnosticPositionFor(spf, tree),
5240 LintWarnings.OSFArraySPF);
5241 }
5242
5243 if (isExternalizable((Type)(e.asType()))) {
5244 log.warning(
5245 TreeInfo.diagnosticPositionFor(spf, tree),
5246 LintWarnings.IneffectualSerialFieldExternalizable);
5247 }
5248
5249 // Warn if serialPersistentFields is initialized to a
5250 // literal null.
5251 JCTree spfDecl = TreeInfo.declarationFor(spf, tree);
5252 if (spfDecl != null && spfDecl.getTag() == VARDEF) {
5253 JCVariableDecl variableDef = (JCVariableDecl) spfDecl;
5254 JCExpression initExpr = variableDef.init;
5255 if (initExpr != null && TreeInfo.isNull(initExpr)) {
5256 log.warning(initExpr.pos(),
5257 LintWarnings.SPFNullInit);
5258 }
5259 }
5260 }
5261
5262 private void checkWriteObject(JCClassDecl tree, Element e, MethodSymbol method) {
5263 // The "synchronized" modifier is seen in the wild on
5264 // readObject and writeObject methods and is generally
5265 // innocuous.
5266
5267 // private void writeObject(ObjectOutputStream stream) throws IOException
5268 checkPrivateNonStaticMethod(tree, method);
5269 isExpectedReturnType(tree, method, syms.voidType, true);
5270 checkOneArg(tree, e, method, syms.objectOutputStreamType);
5271 hasExpectedExceptions(tree, method, true, syms.ioExceptionType);
5272 checkExternalizable(tree, e, method);
5273 }
5274
5275 private boolean hasAppropriateWriteReplace(JCClassDecl tree, MethodSymbol method, boolean warn) {
5276 // ANY-ACCESS-MODIFIER Object writeReplace() throws
5277 // ObjectStreamException
5278
5279 // Excluding abstract, could have a more complicated
5280 // rule based on abstract-ness of the class
5281 return isConcreteInstanceMethod(tree, method, warn) &&
5282 isExpectedReturnType(tree, method, syms.objectType, warn) &&
5283 hasNoArgs(tree, method, warn) &&
5284 hasExpectedExceptions(tree, method, warn, syms.objectStreamExceptionType);
5285 }
5286
5287 private void checkReadObject(JCClassDecl tree, Element e, MethodSymbol method) {
5288 // The "synchronized" modifier is seen in the wild on
5289 // readObject and writeObject methods and is generally
5290 // innocuous.
5291
5292 // private void readObject(ObjectInputStream stream)
5293 // throws IOException, ClassNotFoundException
5294 checkPrivateNonStaticMethod(tree, method);
5295 isExpectedReturnType(tree, method, syms.voidType, true);
5296 checkOneArg(tree, e, method, syms.objectInputStreamType);
5297 hasExpectedExceptions(tree, method, true, syms.ioExceptionType, syms.classNotFoundExceptionType);
5298 checkExternalizable(tree, e, method);
5299 }
5300
5301 private void checkReadObjectNoData(JCClassDecl tree, Element e, MethodSymbol method) {
5302 // private void readObjectNoData() throws ObjectStreamException
5303 checkPrivateNonStaticMethod(tree, method);
5304 isExpectedReturnType(tree, method, syms.voidType, true);
5305 hasNoArgs(tree, method, true);
5306 hasExpectedExceptions(tree, method, true, syms.objectStreamExceptionType);
5307 checkExternalizable(tree, e, method);
5308 }
5309
5310 private void checkReadResolve(JCClassDecl tree, Element e, MethodSymbol method) {
5311 // ANY-ACCESS-MODIFIER Object readResolve()
5312 // throws ObjectStreamException
5313
5314 // Excluding abstract, could have a more complicated
5315 // rule based on abstract-ness of the class
5316 isConcreteInstanceMethod(tree, method, true);
5317 isExpectedReturnType(tree, method, syms.objectType, true);
5318 hasNoArgs(tree, method, true);
5319 hasExpectedExceptions(tree, method, true, syms.objectStreamExceptionType);
5320 }
5321
5322 private void checkWriteExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) {
5323 //public void writeExternal(ObjectOutput) throws IOException
5324 checkExternMethodRecord(tree, e, method, syms.objectOutputType, isExtern);
5325 }
5326
5327 private void checkReadExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) {
5328 // public void readExternal(ObjectInput) throws IOException
5329 checkExternMethodRecord(tree, e, method, syms.objectInputType, isExtern);
5330 }
5331
5332 private void checkExternMethodRecord(JCClassDecl tree, Element e, MethodSymbol method, Type argType,
5333 boolean isExtern) {
5334 if (isExtern && isExternMethod(tree, e, method, argType)) {
5335 log.warning(
5336 TreeInfo.diagnosticPositionFor(method, tree),
5337 LintWarnings.IneffectualExternalizableMethodRecord(method.getSimpleName().toString()));
5338 }
5339 }
5340
5341 void checkPrivateNonStaticMethod(JCClassDecl tree, MethodSymbol method) {
5342 var flags = method.flags();
5343 if ((flags & PRIVATE) == 0) {
5344 log.warning(
5345 TreeInfo.diagnosticPositionFor(method, tree),
5346 LintWarnings.SerialMethodNotPrivate(method.getSimpleName()));
5347 }
5348
5349 if ((flags & STATIC) != 0) {
5350 log.warning(
5351 TreeInfo.diagnosticPositionFor(method, tree),
5352 LintWarnings.SerialMethodStatic(method.getSimpleName()));
5353 }
5354 }
5355
5356 /**
5357 * Per section 1.12 "Serialization of Enum Constants" of
5358 * the serialization specification, due to the special
5359 * serialization handling of enums, any writeObject,
5360 * readObject, writeReplace, and readResolve methods are
5361 * ignored as are serialPersistentFields and
5362 * serialVersionUID fields.
5363 */
5364 @Override
5365 public Void visitTypeAsEnum(TypeElement e,
5366 JCClassDecl p) {
5367 boolean isExtern = isExternalizable((Type)e.asType());
5368 for(Element el : e.getEnclosedElements()) {
5369 runUnderLint(el, p, (enclosed, tree) -> {
5370 String name = enclosed.getSimpleName().toString();
5371 switch(enclosed.getKind()) {
5372 case FIELD -> {
5373 var field = (VarSymbol)enclosed;
5374 if (serialFieldNames.contains(name)) {
5375 log.warning(
5376 TreeInfo.diagnosticPositionFor(field, tree),
5377 LintWarnings.IneffectualSerialFieldEnum(name));
5378 }
5379 }
5380
5381 case METHOD -> {
5382 var method = (MethodSymbol)enclosed;
5383 if (serialMethodNames.contains(name)) {
5384 log.warning(
5385 TreeInfo.diagnosticPositionFor(method, tree),
5386 LintWarnings.IneffectualSerialMethodEnum(name));
5387 }
5388
5389 if (isExtern) {
5390 switch(name) {
5391 case "writeExternal" -> checkWriteExternalEnum(tree, e, method);
5392 case "readExternal" -> checkReadExternalEnum(tree, e, method);
5393 }
5394 }
5395 }
5396
5397 // Also perform checks on any class bodies of enum constants, see JLS 8.9.1.
5398 case ENUM_CONSTANT -> {
5399 var field = (VarSymbol)enclosed;
5400 JCVariableDecl decl = (JCVariableDecl) TreeInfo.declarationFor(field, p);
5401 if (decl.init instanceof JCNewClass nc && nc.def != null) {
5402 ClassSymbol enumConstantType = nc.def.sym;
5403 visitTypeAsEnum(enumConstantType, p);
5404 }
5405 }
5406
5407 }});
5408 }
5409 return null;
5410 }
5411
5412 private void checkWriteExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) {
5413 //public void writeExternal(ObjectOutput) throws IOException
5414 checkExternMethodEnum(tree, e, method, syms.objectOutputType);
5415 }
5416
5417 private void checkReadExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) {
5418 // public void readExternal(ObjectInput) throws IOException
5419 checkExternMethodEnum(tree, e, method, syms.objectInputType);
5420 }
5421
5422 private void checkExternMethodEnum(JCClassDecl tree, Element e, MethodSymbol method, Type argType) {
5423 if (isExternMethod(tree, e, method, argType)) {
5424 log.warning(
5425 TreeInfo.diagnosticPositionFor(method, tree),
5426 LintWarnings.IneffectualExternMethodEnum(method.getSimpleName().toString()));
5427 }
5428 }
5429
5430 private boolean isExternMethod(JCClassDecl tree, Element e, MethodSymbol method, Type argType) {
5431 long flags = method.flags();
5432 Type rtype = method.getReturnType();
5433
5434 // Not necessary to check throws clause in this context
5435 return (flags & PUBLIC) != 0 && (flags & STATIC) == 0 &&
5436 types.isSameType(syms.voidType, rtype) &&
5437 hasExactlyOneArgWithType(tree, e, method, argType);
5438 }
5439
5440 /**
5441 * Most serialization-related fields and methods on interfaces
5442 * are ineffectual or problematic.
5443 */
5444 @Override
5445 public Void visitTypeAsInterface(TypeElement e,
5446 JCClassDecl p) {
5447 for(Element el : e.getEnclosedElements()) {
5448 runUnderLint(el, p, (enclosed, tree) -> {
5449 String name = null;
5450 switch(enclosed.getKind()) {
5451 case FIELD -> {
5452 var field = (VarSymbol)enclosed;
5453 name = field.getSimpleName().toString();
5454 switch(name) {
5455 case "serialPersistentFields" -> {
5456 log.warning(
5457 TreeInfo.diagnosticPositionFor(field, tree),
5458 LintWarnings.IneffectualSerialFieldInterface);
5459 }
5460
5461 case "serialVersionUID" -> {
5462 checkSerialVersionUID(tree, e, field);
5463 }
5464 }
5465 }
5466
5467 case METHOD -> {
5468 var method = (MethodSymbol)enclosed;
5469 name = enclosed.getSimpleName().toString();
5470 if (serialMethodNames.contains(name)) {
5471 switch (name) {
5472 case
5473 "readObject",
5474 "readObjectNoData",
5475 "writeObject" -> checkPrivateMethod(tree, e, method);
5476
5477 case
5478 "writeReplace",
5479 "readResolve" -> checkDefaultIneffective(tree, e, method);
5480
5481 default -> throw new AssertionError();
5482 }
5483
5484 }
5485 }}
5486 });
5487 }
5488
5489 return null;
5490 }
5491
5492 private void checkPrivateMethod(JCClassDecl tree,
5493 Element e,
5494 MethodSymbol method) {
5495 if ((method.flags() & PRIVATE) == 0) {
5496 log.warning(
5497 TreeInfo.diagnosticPositionFor(method, tree),
5498 LintWarnings.NonPrivateMethodWeakerAccess);
5499 }
5500 }
5501
5502 private void checkDefaultIneffective(JCClassDecl tree,
5503 Element e,
5504 MethodSymbol method) {
5505 if ((method.flags() & DEFAULT) == DEFAULT) {
5506 log.warning(
5507 TreeInfo.diagnosticPositionFor(method, tree),
5508 LintWarnings.DefaultIneffective);
5509
5510 }
5511 }
5512
5513 @Override
5514 public Void visitTypeAsAnnotationType(TypeElement e,
5515 JCClassDecl p) {
5516 // Per the JLS, annotation types are not serializeable
5517 return null;
5518 }
5519
5520 /**
5521 * From the Java Object Serialization Specification, 1.13
5522 * Serialization of Records:
5523 *
5524 * "The process by which record objects are serialized or
5525 * externalized cannot be customized; any class-specific
5526 * writeObject, readObject, readObjectNoData, writeExternal,
5527 * and readExternal methods defined by record classes are
5528 * ignored during serialization and deserialization. However,
5529 * a substitute object to be serialized or a designate
5530 * replacement may be specified, by the writeReplace and
5531 * readResolve methods, respectively. Any
5532 * serialPersistentFields field declaration is
5533 * ignored. Documenting serializable fields and data for
5534 * record classes is unnecessary, since there is no variation
5535 * in the serial form, other than whether a substitute or
5536 * replacement object is used. The serialVersionUID of a
5537 * record class is 0L unless explicitly declared. The
5538 * requirement for matching serialVersionUID values is waived
5539 * for record classes."
5540 */
5541 @Override
5542 public Void visitTypeAsRecord(TypeElement e,
5543 JCClassDecl p) {
5544 boolean isExtern = isExternalizable((Type)e.asType());
5545 for(Element el : e.getEnclosedElements()) {
5546 runUnderLint(el, p, (enclosed, tree) -> {
5547 String name = enclosed.getSimpleName().toString();
5548 switch(enclosed.getKind()) {
5549 case FIELD -> {
5550 var field = (VarSymbol)enclosed;
5551 switch(name) {
5552 case "serialPersistentFields" -> {
5553 log.warning(
5554 TreeInfo.diagnosticPositionFor(field, tree),
5555 LintWarnings.IneffectualSerialFieldRecord);
5556 }
5557
5558 case "serialVersionUID" -> {
5559 // Could generate additional warning that
5560 // svuid value is not checked to match for
5561 // records.
5562 checkSerialVersionUID(tree, e, field);
5563 }}
5564 }
5565
5566 case METHOD -> {
5567 var method = (MethodSymbol)enclosed;
5568 switch(name) {
5569 case "writeReplace" -> hasAppropriateWriteReplace(tree, method, true);
5570 case "readResolve" -> checkReadResolve(tree, e, method);
5571
5572 case "writeExternal" -> checkWriteExternalRecord(tree, e, method, isExtern);
5573 case "readExternal" -> checkReadExternalRecord(tree, e, method, isExtern);
5574
5575 default -> {
5576 if (serialMethodNames.contains(name)) {
5577 log.warning(
5578 TreeInfo.diagnosticPositionFor(method, tree),
5579 LintWarnings.IneffectualSerialMethodRecord(name));
5580 }
5581 }}
5582 }}});
5583 }
5584 return null;
5585 }
5586
5587 boolean isConcreteInstanceMethod(JCClassDecl tree,
5588 MethodSymbol method,
5589 boolean warn) {
5590 if ((method.flags() & (STATIC | ABSTRACT)) != 0) {
5591 if (warn) {
5592 log.warning(
5593 TreeInfo.diagnosticPositionFor(method, tree),
5594 LintWarnings.SerialConcreteInstanceMethod(method.getSimpleName()));
5595 }
5596 return false;
5597 }
5598 return true;
5599 }
5600
5601 private boolean isExpectedReturnType(JCClassDecl tree,
5602 MethodSymbol method,
5603 Type expectedReturnType,
5604 boolean warn) {
5605 // Note: there may be complications checking writeReplace
5606 // and readResolve since they return Object and could, in
5607 // principle, have covariant overrides and any synthetic
5608 // bridge method would not be represented here for
5609 // checking.
5610 Type rtype = method.getReturnType();
5611 if (!types.isSameType(expectedReturnType, rtype)) {
5612 if (warn) {
5613 log.warning(
5614 TreeInfo.diagnosticPositionFor(method, tree),
5615 LintWarnings.SerialMethodUnexpectedReturnType(method.getSimpleName(),
5616 rtype, expectedReturnType));
5617 }
5618 return false;
5619 }
5620 return true;
5621 }
5622
5623 private void checkOneArg(JCClassDecl tree,
5624 Element enclosing,
5625 MethodSymbol method,
5626 Type expectedType) {
5627 String name = method.getSimpleName().toString();
5628
5629 var parameters= method.getParameters();
5630
5631 if (parameters.size() != 1) {
5632 log.warning(
5633 TreeInfo.diagnosticPositionFor(method, tree),
5634 LintWarnings.SerialMethodOneArg(method.getSimpleName(), parameters.size()));
5635 return;
5636 }
5637
5638 Type parameterType = parameters.get(0).asType();
5639 if (!types.isSameType(parameterType, expectedType)) {
5640 log.warning(
5641 TreeInfo.diagnosticPositionFor(method, tree),
5642 LintWarnings.SerialMethodParameterType(method.getSimpleName(),
5643 expectedType,
5644 parameterType));
5645 }
5646 }
5647
5648 private boolean hasExactlyOneArgWithType(JCClassDecl tree,
5649 Element enclosing,
5650 MethodSymbol method,
5651 Type expectedType) {
5652 var parameters = method.getParameters();
5653 return (parameters.size() == 1) &&
5654 types.isSameType(parameters.get(0).asType(), expectedType);
5655 }
5656
5657
5658 boolean hasNoArgs(JCClassDecl tree, MethodSymbol method, boolean warn) {
5659 var parameters = method.getParameters();
5660 if (!parameters.isEmpty()) {
5661 if (warn) {
5662 log.warning(
5663 TreeInfo.diagnosticPositionFor(parameters.get(0), tree),
5664 LintWarnings.SerialMethodNoArgs(method.getSimpleName()));
5665 }
5666 return false;
5667 }
5668 return true;
5669 }
5670
5671 private void checkExternalizable(JCClassDecl tree, Element enclosing, MethodSymbol method) {
5672 // If the enclosing class is externalizable, warn for the method
5673 if (isExternalizable((Type)enclosing.asType())) {
5674 log.warning(
5675 TreeInfo.diagnosticPositionFor(method, tree),
5676 LintWarnings.IneffectualSerialMethodExternalizable(method.getSimpleName()));
5677 }
5678 return;
5679 }
5680
5681 private boolean hasExpectedExceptions(JCClassDecl tree,
5682 MethodSymbol method,
5683 boolean warn,
5684 Type... declaredExceptions) {
5685 for (Type thrownType: method.getThrownTypes()) {
5686 // For each exception in the throws clause of the
5687 // method, if not an Error and not a RuntimeException,
5688 // check if the exception is a subtype of a declared
5689 // exception from the throws clause of the
5690 // serialization method in question.
5691 if (types.isSubtype(thrownType, syms.runtimeExceptionType) ||
5692 types.isSubtype(thrownType, syms.errorType) ) {
5693 continue;
5694 } else {
5695 boolean declared = false;
5696 for (Type declaredException : declaredExceptions) {
5697 if (types.isSubtype(thrownType, declaredException)) {
5698 declared = true;
5699 continue;
5700 }
5701 }
5702 if (!declared) {
5703 if (warn) {
5704 log.warning(
5705 TreeInfo.diagnosticPositionFor(method, tree),
5706 LintWarnings.SerialMethodUnexpectedException(method.getSimpleName(),
5707 thrownType));
5708 }
5709 return false;
5710 }
5711 }
5712 }
5713 return true;
5714 }
5715
5716 private <E extends Element> Void runUnderLint(E symbol, JCClassDecl p, BiConsumer<E, JCClassDecl> task) {
5717 Lint prevLint = lint;
5718 try {
5719 lint = lint.augment((Symbol) symbol);
5720
5721 if (lint.isEnabled(LintCategory.SERIAL)) {
5722 task.accept(symbol, p);
5723 }
5724
5725 return null;
5726 } finally {
5727 lint = prevLint;
5728 }
5729 }
5730
5731 }
5732
5733 void checkRequiresIdentity(JCTree tree, Lint lint) {
5734 switch (tree) {
5735 case JCClassDecl classDecl -> {
5736 Type st = types.supertype(classDecl.sym.type);
5737 if (st != null &&
5738 // no need to recheck j.l.Object, shortcut,
5739 st.tsym != syms.objectType.tsym &&
5740 // this one could be null, no explicit extends
5741 classDecl.extending != null) {
5742 checkIfIdentityIsExpected(classDecl.extending.pos(), st, lint);
5743 }
5744 for (JCExpression intrface: classDecl.implementing) {
5745 checkIfIdentityIsExpected(intrface.pos(), intrface.type, lint);
5746 }
5747 for (JCTypeParameter tp : classDecl.typarams) {
5748 checkIfIdentityIsExpected(tp.pos(), tp.type, lint);
5749 }
5750 }
5751 case JCVariableDecl variableDecl -> {
5752 if (variableDecl.vartype != null &&
5753 (variableDecl.sym.flags_field & RECORD) == 0 ||
5754 (variableDecl.sym.flags_field & ~(Flags.PARAMETER | RECORD | GENERATED_MEMBER)) != 0) {
5755 /* we don't want to warn twice so if this variable is a compiler generated parameter of
5756 * a canonical record constructor, we don't want to issue a warning as we will warn the
5757 * corresponding compiler generated private record field anyways
5758 */
5759 checkIfIdentityIsExpected(variableDecl.vartype.pos(), variableDecl.vartype.type, lint);
5760 }
5761 }
5762 case JCTypeCast typeCast -> checkIfIdentityIsExpected(typeCast.clazz.pos(), typeCast.clazz.type, lint);
5763 case JCBindingPattern bindingPattern -> {
5764 if (bindingPattern.var.vartype != null) {
5765 checkIfIdentityIsExpected(bindingPattern.var.vartype.pos(), bindingPattern.var.vartype.type, lint);
5766 }
5767 }
5768 case JCMethodDecl methodDecl -> {
5769 for (JCTypeParameter tp : methodDecl.typarams) {
5770 checkIfIdentityIsExpected(tp.pos(), tp.type, lint);
5771 }
5772 if (methodDecl.restype != null && !methodDecl.restype.type.hasTag(VOID)) {
5773 checkIfIdentityIsExpected(methodDecl.restype.pos(), methodDecl.restype.type, lint);
5774 }
5775 }
5776 case JCMemberReference mref -> {
5777 checkIfIdentityIsExpected(mref.expr.pos(), mref.target, lint);
5778 checkIfTypeParamsRequiresIdentity(mref.sym.getMetadata(), mref.typeargs, lint);
5779 }
5780 case JCPolyExpression poly
5781 when (poly instanceof JCNewClass || poly instanceof JCMethodInvocation) -> {
5782 if (poly instanceof JCNewClass newClass) {
5783 checkIfIdentityIsExpected(newClass.clazz.pos(), newClass.clazz.type, lint);
5784 }
5785 List<JCExpression> argExps = poly instanceof JCNewClass ?
5786 ((JCNewClass)poly).args :
5787 ((JCMethodInvocation)poly).args;
5788 Symbol msym = TreeInfo.symbolFor(poly);
5789 if (msym != null) {
5790 if (!argExps.isEmpty() && msym instanceof MethodSymbol ms && ms.params != null) {
5791 VarSymbol lastParam = ms.params.head;
5792 for (VarSymbol param: ms.params) {
5793 if ((param.flags_field & REQUIRES_IDENTITY) != 0 && argExps.head.type.isValueBased()) {
5794 log.warning(argExps.head.pos(), LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5795 }
5796 lastParam = param;
5797 argExps = argExps.tail;
5798 }
5799 while (argExps != null && !argExps.isEmpty() && lastParam != null) {
5800 if ((lastParam.flags_field & REQUIRES_IDENTITY) != 0 && argExps.head.type.isValueBased()) {
5801 log.warning(argExps.head.pos(), LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5802 }
5803 argExps = argExps.tail;
5804 }
5805 }
5806 checkIfTypeParamsRequiresIdentity(
5807 msym.getMetadata(),
5808 poly instanceof JCNewClass ?
5809 ((JCNewClass)poly).typeargs :
5810 ((JCMethodInvocation)poly).typeargs,
5811 lint);
5812 }
5813 }
5814 default -> throw new AssertionError("unexpected tree " + tree);
5815 }
5816 }
5817
5818 /** Check if a type required an identity class
5819 */
5820 private boolean checkIfIdentityIsExpected(DiagnosticPosition pos, Type t, Lint lint) {
5821 if (t != null &&
5822 lint != null &&
5823 lint.isEnabled(LintCategory.IDENTITY)) {
5824 RequiresIdentityVisitor requiresIdentityVisitor = new RequiresIdentityVisitor();
5825 // we need to avoid recursion due to self referencing type vars or captures, this is why we need a set
5826 requiresIdentityVisitor.visit(t, new HashSet<>());
5827 if (requiresIdentityVisitor.requiresWarning) {
5828 log.warning(pos, LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5829 return true;
5830 }
5831 }
5832 return false;
5833 }
5834
5835 // where
5836 private class RequiresIdentityVisitor extends Types.SimpleVisitor<Void, Set<Type>> {
5837 boolean requiresWarning = false;
5838
5839 @Override
5840 public Void visitType(Type t, Set<Type> seen) {
5841 return null;
5842 }
5843
5844 @Override
5845 public Void visitWildcardType(WildcardType t, Set<Type> seen) {
5846 return visit(t.type, seen);
5847 }
5848
5849 @Override
5850 public Void visitTypeVar(TypeVar t, Set<Type> seen) {
5851 if (seen.add(t)) {
5852 visit(t.getUpperBound(), seen);
5853 }
5854 return null;
5855 }
5856
5857 @Override
5858 public Void visitCapturedType(CapturedType t, Set<Type> seen) {
5859 if (seen.add(t)) {
5860 visit(t.getUpperBound(), seen);
5861 visit(t.getLowerBound(), seen);
5862 }
5863 return null;
5864 }
5865
5866 @Override
5867 public Void visitArrayType(ArrayType t, Set<Type> seen) {
5868 return visit(t.elemtype, seen);
5869 }
5870
5871 @Override
5872 public Void visitClassType(ClassType t, Set<Type> seen) {
5873 if (t != null && t.tsym != null) {
5874 SymbolMetadata sm = t.tsym.getMetadata();
5875 if (sm != null && !t.getTypeArguments().isEmpty()) {
5876 if (sm.getTypeAttributes().stream()
5877 .filter(ta -> isRequiresIdentityAnnotation(ta.type.tsym) &&
5878 t.getTypeArguments().get(ta.position.parameter_index) != null &&
5879 t.getTypeArguments().get(ta.position.parameter_index).isValueBased()).findAny().isPresent()) {
5880 requiresWarning = true;
5881 return null;
5882 }
5883 }
5884 }
5885 visit(t.getEnclosingType(), seen);
5886 for (Type targ : t.getTypeArguments()) {
5887 visit(targ, seen);
5888 }
5889 return null;
5890 }
5891 } // RequiresIdentityVisitor
5892
5893 private void checkIfTypeParamsRequiresIdentity(SymbolMetadata sm,
5894 List<JCExpression> typeParamTrees,
5895 Lint lint) {
5896 if (typeParamTrees != null && !typeParamTrees.isEmpty()) {
5897 for (JCExpression targ : typeParamTrees) {
5898 checkIfIdentityIsExpected(targ.pos(), targ.type, lint);
5899 }
5900 if (sm != null)
5901 sm.getTypeAttributes().stream()
5902 .filter(ta -> isRequiresIdentityAnnotation(ta.type.tsym) &&
5903 typeParamTrees.get(ta.position.parameter_index).type != null &&
5904 typeParamTrees.get(ta.position.parameter_index).type.isValueBased())
5905 .forEach(ta -> log.warning(typeParamTrees.get(ta.position.parameter_index).pos(),
5906 CompilerProperties.LintWarnings.AttemptToUseValueBasedWhereIdentityExpected));
5907 }
5908 }
5909
5910 private boolean isRequiresIdentityAnnotation(TypeSymbol annoType) {
5911 return annoType == syms.requiresIdentityType.tsym ||
5912 annoType.flatName() == syms.requiresIdentityInternalType.tsym.flatName();
5913 }
5914 }