1 /*
2 * Copyright (c) 1999, 2014, 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
30 import javax.tools.JavaFileManager;
31
32 import com.sun.tools.javac.code.*;
33 import com.sun.tools.javac.code.Attribute.Compound;
34 import com.sun.tools.javac.jvm.*;
35 import com.sun.tools.javac.tree.*;
36 import com.sun.tools.javac.util.*;
37 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
38 import com.sun.tools.javac.util.List;
39
40 import com.sun.tools.javac.code.Lint;
41 import com.sun.tools.javac.code.Lint.LintCategory;
42 import com.sun.tools.javac.code.Type.*;
43 import com.sun.tools.javac.code.Symbol.*;
44 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
45 import com.sun.tools.javac.comp.Infer.InferenceContext;
46 import com.sun.tools.javac.comp.Infer.FreeTypeListener;
47 import com.sun.tools.javac.tree.JCTree.*;
48 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
49
50 import static com.sun.tools.javac.code.Flags.*;
51 import static com.sun.tools.javac.code.Flags.ANNOTATION;
52 import static com.sun.tools.javac.code.Flags.SYNCHRONIZED;
53 import static com.sun.tools.javac.code.Kinds.*;
54 import static com.sun.tools.javac.code.TypeTag.*;
55 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
56
57 import static com.sun.tools.javac.tree.JCTree.Tag.*;
58
59 /** Type checking helper class for the attribution phase.
60 *
61 * <p><b>This is NOT part of any supported API.
62 * If you write code that depends on this, you do so at your own risk.
63 * This code and its internal interfaces are subject to change or
64 * deletion without notice.</b>
65 */
66 public class Check {
67 protected static final Context.Key<Check> checkKey = new Context.Key<>();
68
69 private final Names names;
70 private final Log log;
71 private final Resolve rs;
72 private final Symtab syms;
73 private final Enter enter;
74 private final DeferredAttr deferredAttr;
75 private final Infer infer;
76 private final Types types;
77 private final JCDiagnostic.Factory diags;
78 private boolean warnOnSyntheticConflicts;
79 private boolean suppressAbortOnBadClassFile;
80 private boolean enableSunApiLintControl;
81 private final TreeInfo treeinfo;
82 private final JavaFileManager fileManager;
83 private final Profile profile;
84 private final boolean warnOnAccessToSensitiveMembers;
85
86 // The set of lint options currently in effect. It is initialized
87 // from the context, and then is set/reset as needed by Attr as it
88 // visits all the various parts of the trees during attribution.
89 private Lint lint;
90
91 // The method being analyzed in Attr - it is set/reset as needed by
92 // Attr as it visits new method declarations.
93 private MethodSymbol method;
94
95 public static Check instance(Context context) {
96 Check instance = context.get(checkKey);
97 if (instance == null)
98 instance = new Check(context);
99 return instance;
100 }
101
102 protected Check(Context context) {
103 context.put(checkKey, this);
104
105 names = Names.instance(context);
106 dfltTargetMeta = new Name[] { names.PACKAGE, names.TYPE,
107 names.FIELD, names.METHOD, names.CONSTRUCTOR,
108 names.ANNOTATION_TYPE, names.LOCAL_VARIABLE, names.PARAMETER};
109 log = Log.instance(context);
110 rs = Resolve.instance(context);
111 syms = Symtab.instance(context);
112 enter = Enter.instance(context);
113 deferredAttr = DeferredAttr.instance(context);
114 infer = Infer.instance(context);
115 types = Types.instance(context);
116 diags = JCDiagnostic.Factory.instance(context);
117 Options options = Options.instance(context);
118 lint = Lint.instance(context);
119 treeinfo = TreeInfo.instance(context);
120 fileManager = context.get(JavaFileManager.class);
121
122 Source source = Source.instance(context);
123 allowGenerics = source.allowGenerics();
124 allowVarargs = source.allowVarargs();
125 allowAnnotations = source.allowAnnotations();
126 allowCovariantReturns = source.allowCovariantReturns();
127 allowSimplifiedVarargs = source.allowSimplifiedVarargs();
128 allowDefaultMethods = source.allowDefaultMethods();
129 allowStrictMethodClashCheck = source.allowStrictMethodClashCheck();
130 allowPrivateSafeVarargs = source.allowPrivateSafeVarargs();
131 complexInference = options.isSet("complexinference");
132 warnOnSyntheticConflicts = options.isSet("warnOnSyntheticConflicts");
133 suppressAbortOnBadClassFile = options.isSet("suppressAbortOnBadClassFile");
134 enableSunApiLintControl = options.isSet("enableSunApiLintControl");
135 warnOnAccessToSensitiveMembers = options.isSet("warnOnAccessToSensitiveMembers");
136
137 Target target = Target.instance(context);
138 syntheticNameChar = target.syntheticNameChar();
139
140 profile = Profile.instance(context);
141
142 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
143 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
144 boolean verboseSunApi = lint.isEnabled(LintCategory.SUNAPI);
145 boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
146
147 deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
148 enforceMandatoryWarnings, "deprecated", LintCategory.DEPRECATION);
149 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
150 enforceMandatoryWarnings, "unchecked", LintCategory.UNCHECKED);
151 sunApiHandler = new MandatoryWarningHandler(log, verboseSunApi,
152 enforceMandatoryWarnings, "sunapi", null);
153
154 deferredLintHandler = DeferredLintHandler.instance(context);
155 }
156
157 /** Switch: generics enabled?
158 */
159 boolean allowGenerics;
160
161 /** Switch: varargs enabled?
162 */
163 boolean allowVarargs;
164
165 /** Switch: annotations enabled?
166 */
167 boolean allowAnnotations;
168
169 /** Switch: covariant returns enabled?
170 */
171 boolean allowCovariantReturns;
172
173 /** Switch: simplified varargs enabled?
174 */
175 boolean allowSimplifiedVarargs;
176
177 /** Switch: default methods enabled?
178 */
179 boolean allowDefaultMethods;
180
181 /** Switch: should unrelated return types trigger a method clash?
182 */
183 boolean allowStrictMethodClashCheck;
184
185 /** Switch: can the @SafeVarargs annotation be applied to private methods?
186 */
187 boolean allowPrivateSafeVarargs;
188
189 /** Switch: -complexinference option set?
190 */
191 boolean complexInference;
192
193 /** Character for synthetic names
194 */
195 char syntheticNameChar;
196
197 /** A table mapping flat names of all compiled classes in this run to their
198 * symbols; maintained from outside.
199 */
200 public Map<Name,ClassSymbol> compiled = new HashMap<>();
201
202 /** A handler for messages about deprecated usage.
203 */
204 private MandatoryWarningHandler deprecationHandler;
205
206 /** A handler for messages about unchecked or unsafe usage.
207 */
208 private MandatoryWarningHandler uncheckedHandler;
209
210 /** A handler for messages about using proprietary API.
211 */
212 private MandatoryWarningHandler sunApiHandler;
213
214 /** A handler for deferred lint warnings.
215 */
216 private DeferredLintHandler deferredLintHandler;
217
218 /* *************************************************************************
219 * Errors and Warnings
220 **************************************************************************/
221
222 Lint setLint(Lint newLint) {
223 Lint prev = lint;
224 lint = newLint;
225 return prev;
226 }
227
228 MethodSymbol setMethod(MethodSymbol newMethod) {
229 MethodSymbol prev = method;
230 method = newMethod;
231 return prev;
232 }
233
234 /** Warn about deprecated symbol.
235 * @param pos Position to be used for error reporting.
236 * @param sym The deprecated symbol.
237 */
238 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
239 if (!lint.isSuppressed(LintCategory.DEPRECATION))
240 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
241 }
242
243 /** Warn about unchecked operation.
244 * @param pos Position to be used for error reporting.
245 * @param msg A string describing the problem.
246 */
247 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
248 if (!lint.isSuppressed(LintCategory.UNCHECKED))
249 uncheckedHandler.report(pos, msg, args);
250 }
251
252 /** Warn about unsafe vararg method decl.
253 * @param pos Position to be used for error reporting.
254 */
255 void warnUnsafeVararg(DiagnosticPosition pos, String key, Object... args) {
256 if (lint.isEnabled(LintCategory.VARARGS) && allowSimplifiedVarargs)
257 log.warning(LintCategory.VARARGS, pos, key, args);
258 }
259
260 /** Warn about using proprietary API.
261 * @param pos Position to be used for error reporting.
262 * @param msg A string describing the problem.
263 */
264 public void warnSunApi(DiagnosticPosition pos, String msg, Object... args) {
265 if (!lint.isSuppressed(LintCategory.SUNAPI))
266 sunApiHandler.report(pos, msg, args);
267 }
268
269 public void warnStatic(DiagnosticPosition pos, String msg, Object... args) {
270 if (lint.isEnabled(LintCategory.STATIC))
271 log.warning(LintCategory.STATIC, pos, msg, args);
272 }
273
274 /**
275 * Report any deferred diagnostics.
276 */
277 public void reportDeferredDiagnostics() {
278 deprecationHandler.reportDeferredDiagnostic();
279 uncheckedHandler.reportDeferredDiagnostic();
280 sunApiHandler.reportDeferredDiagnostic();
281 }
282
283
284 /** Report a failure to complete a class.
285 * @param pos Position to be used for error reporting.
286 * @param ex The failure to report.
287 */
288 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
289 log.error(JCDiagnostic.DiagnosticFlag.NON_DEFERRABLE, pos, "cant.access", ex.sym, ex.getDetailValue());
290 if (ex instanceof ClassFinder.BadClassFile
291 && !suppressAbortOnBadClassFile) throw new Abort();
292 else return syms.errType;
293 }
294
295 /** Report an error that wrong type tag was found.
296 * @param pos Position to be used for error reporting.
297 * @param required An internationalized string describing the type tag
298 * required.
299 * @param found The type that was found.
300 */
301 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
302 // this error used to be raised by the parser,
303 // but has been delayed to this point:
304 if (found instanceof Type && ((Type)found).hasTag(VOID)) {
305 log.error(pos, "illegal.start.of.type");
306 return syms.errType;
307 }
308 log.error(pos, "type.found.req", found, required);
309 return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
310 }
311
312 /** Report an error that symbol cannot be referenced before super
313 * has been called.
314 * @param pos Position to be used for error reporting.
315 * @param sym The referenced symbol.
316 */
317 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
318 log.error(pos, "cant.ref.before.ctor.called", sym);
319 }
320
321 /** Report duplicate declaration error.
322 */
323 void duplicateError(DiagnosticPosition pos, Symbol sym) {
324 if (!sym.type.isErroneous()) {
325 Symbol location = sym.location();
326 if (location.kind == MTH &&
327 ((MethodSymbol)location).isStaticOrInstanceInit()) {
328 log.error(pos, "already.defined.in.clinit", kindName(sym), sym,
329 kindName(sym.location()), kindName(sym.location().enclClass()),
330 sym.location().enclClass());
331 } else {
332 log.error(pos, "already.defined", kindName(sym), sym,
333 kindName(sym.location()), sym.location());
334 }
335 }
336 }
337
338 /** Report array/varargs duplicate declaration
339 */
340 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
341 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
342 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
343 }
344 }
345
346 /* ************************************************************************
347 * duplicate declaration checking
348 *************************************************************************/
349
350 /** Check that variable does not hide variable with same name in
351 * immediately enclosing local scope.
352 * @param pos Position for error reporting.
353 * @param v The symbol.
354 * @param s The scope.
355 */
356 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
357 if (s.next != null) {
358 for (Scope.Entry e = s.next.lookup(v.name);
359 e.scope != null && e.sym.owner == v.owner;
360 e = e.next()) {
361 if (e.sym.kind == VAR &&
362 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
363 v.name != names.error) {
364 duplicateError(pos, e.sym);
365 return;
366 }
367 }
368 }
369 }
370
371 /** Check that a class or interface does not hide a class or
372 * interface with same name in immediately enclosing local scope.
373 * @param pos Position for error reporting.
374 * @param c The symbol.
375 * @param s The scope.
376 */
377 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
378 if (s.next != null) {
379 for (Scope.Entry e = s.next.lookup(c.name);
380 e.scope != null && e.sym.owner == c.owner;
381 e = e.next()) {
382 if (e.sym.kind == TYP && !e.sym.type.hasTag(TYPEVAR) &&
383 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
384 c.name != names.error) {
385 duplicateError(pos, e.sym);
386 return;
387 }
388 }
389 }
390 }
391
392 /** Check that class does not have the same name as one of
393 * its enclosing classes, or as a class defined in its enclosing scope.
394 * return true if class is unique in its enclosing scope.
395 * @param pos Position for error reporting.
396 * @param name The class name.
397 * @param s The enclosing scope.
398 */
399 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
400 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
401 if (e.sym.kind == TYP && e.sym.name != names.error) {
402 duplicateError(pos, e.sym);
403 return false;
404 }
405 }
406 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
407 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
408 duplicateError(pos, sym);
409 return true;
410 }
411 }
412 return true;
413 }
414
415 /* *************************************************************************
416 * Class name generation
417 **************************************************************************/
418
419 /** Return name of local class.
420 * This is of the form {@code <enclClass> $ n <classname> }
421 * where
422 * enclClass is the flat name of the enclosing class,
423 * classname is the simple name of the local class
424 */
425 Name localClassName(ClassSymbol c) {
426 for (int i=1; ; i++) {
427 Name flatname = names.
428 fromString("" + c.owner.enclClass().flatname +
429 syntheticNameChar + i +
430 c.name);
431 if (compiled.get(flatname) == null) return flatname;
432 }
433 }
434
435 public void newRound() {
436 compiled.clear();
437 }
438
439 /* *************************************************************************
440 * Type Checking
441 **************************************************************************/
442
443 /**
444 * A check context is an object that can be used to perform compatibility
445 * checks - depending on the check context, meaning of 'compatibility' might
446 * vary significantly.
447 */
448 public interface CheckContext {
449 /**
450 * Is type 'found' compatible with type 'req' in given context
451 */
452 boolean compatible(Type found, Type req, Warner warn);
453 /**
454 * Report a check error
455 */
456 void report(DiagnosticPosition pos, JCDiagnostic details);
457 /**
458 * Obtain a warner for this check context
459 */
460 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req);
461
462 public Infer.InferenceContext inferenceContext();
463
464 public DeferredAttr.DeferredAttrContext deferredAttrContext();
465 }
466
467 /**
468 * This class represent a check context that is nested within another check
469 * context - useful to check sub-expressions. The default behavior simply
470 * redirects all method calls to the enclosing check context leveraging
471 * the forwarding pattern.
472 */
473 static class NestedCheckContext implements CheckContext {
474 CheckContext enclosingContext;
475
476 NestedCheckContext(CheckContext enclosingContext) {
477 this.enclosingContext = enclosingContext;
478 }
479
480 public boolean compatible(Type found, Type req, Warner warn) {
481 return enclosingContext.compatible(found, req, warn);
482 }
483
484 public void report(DiagnosticPosition pos, JCDiagnostic details) {
485 enclosingContext.report(pos, details);
486 }
487
488 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
489 return enclosingContext.checkWarner(pos, found, req);
490 }
491
492 public Infer.InferenceContext inferenceContext() {
493 return enclosingContext.inferenceContext();
494 }
495
496 public DeferredAttrContext deferredAttrContext() {
497 return enclosingContext.deferredAttrContext();
498 }
499 }
500
501 /**
502 * Check context to be used when evaluating assignment/return statements
503 */
504 CheckContext basicHandler = new CheckContext() {
505 public void report(DiagnosticPosition pos, JCDiagnostic details) {
506 log.error(pos, "prob.found.req", details);
507 }
508 public boolean compatible(Type found, Type req, Warner warn) {
509 return types.isAssignable(found, req, warn);
510 }
511
512 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
513 return convertWarner(pos, found, req);
514 }
515
516 public InferenceContext inferenceContext() {
517 return infer.emptyContext;
518 }
519
520 public DeferredAttrContext deferredAttrContext() {
521 return deferredAttr.emptyDeferredAttrContext;
522 }
523
524 @Override
525 public String toString() {
526 return "CheckContext: basicHandler";
527 }
528 };
529
530 /** Check that a given type is assignable to a given proto-type.
531 * If it is, return the type, otherwise return errType.
532 * @param pos Position to be used for error reporting.
533 * @param found The type that was found.
534 * @param req The type that was required.
535 */
536 Type checkType(DiagnosticPosition pos, Type found, Type req) {
537 return checkType(pos, found, req, basicHandler);
538 }
539
540 Type checkType(final DiagnosticPosition pos, final Type found, final Type req, final CheckContext checkContext) {
541 final Infer.InferenceContext inferenceContext = checkContext.inferenceContext();
542 if (inferenceContext.free(req)) {
543 inferenceContext.addFreeTypeListener(List.of(req), new FreeTypeListener() {
544 @Override
545 public void typesInferred(InferenceContext inferenceContext) {
546 checkType(pos, inferenceContext.asInstType(found), inferenceContext.asInstType(req), checkContext);
547 }
548 });
549 }
550 if (req.hasTag(ERROR))
551 return req;
552 if (req.hasTag(NONE))
553 return found;
554 if (checkContext.compatible(found, req, checkContext.checkWarner(pos, found, req))) {
555 return found;
556 } else {
557 if (found.isNumeric() && req.isNumeric()) {
558 checkContext.report(pos, diags.fragment("possible.loss.of.precision", found, req));
559 return types.createErrorType(found);
560 }
561 checkContext.report(pos, diags.fragment("inconvertible.types", found, req));
562 return types.createErrorType(found);
563 }
564 }
565
566 /** Check that a given type can be cast to a given target type.
567 * Return the result of the cast.
568 * @param pos Position to be used for error reporting.
569 * @param found The type that is being cast.
570 * @param req The target type of the cast.
571 */
572 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
573 return checkCastable(pos, found, req, basicHandler);
574 }
575 Type checkCastable(DiagnosticPosition pos, Type found, Type req, CheckContext checkContext) {
576 if (types.isCastable(found, req, castWarner(pos, found, req))) {
577 return req;
578 } else {
579 checkContext.report(pos, diags.fragment("inconvertible.types", found, req));
580 return types.createErrorType(found);
581 }
582 }
583
584 /** Check for redundant casts (i.e. where source type is a subtype of target type)
585 * The problem should only be reported for non-292 cast
586 */
587 public void checkRedundantCast(Env<AttrContext> env, final JCTypeCast tree) {
588 if (!tree.type.isErroneous()
589 && types.isSameType(tree.expr.type, tree.clazz.type)
590 && !(ignoreAnnotatedCasts && TreeInfo.containsTypeAnnotation(tree.clazz))
591 && !is292targetTypeCast(tree)) {
592 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
593 @Override
594 public void report() {
595 if (lint.isEnabled(Lint.LintCategory.CAST))
596 log.warning(Lint.LintCategory.CAST,
597 tree.pos(), "redundant.cast", tree.expr.type);
598 }
599 });
600 }
601 }
602 //where
603 private boolean is292targetTypeCast(JCTypeCast tree) {
604 boolean is292targetTypeCast = false;
605 JCExpression expr = TreeInfo.skipParens(tree.expr);
606 if (expr.hasTag(APPLY)) {
607 JCMethodInvocation apply = (JCMethodInvocation)expr;
608 Symbol sym = TreeInfo.symbol(apply.meth);
609 is292targetTypeCast = sym != null &&
610 sym.kind == MTH &&
611 (sym.flags() & HYPOTHETICAL) != 0;
612 }
613 return is292targetTypeCast;
614 }
615
616 private static final boolean ignoreAnnotatedCasts = true;
617
618 /** Check that a type is within some bounds.
619 *
620 * Used in TypeApply to verify that, e.g., X in {@code V<X>} is a valid
621 * type argument.
622 * @param a The type that should be bounded by bs.
623 * @param bound The bound.
624 */
625 private boolean checkExtends(Type a, Type bound) {
626 if (a.isUnbound()) {
627 return true;
628 } else if (!a.hasTag(WILDCARD)) {
629 a = types.cvarUpperBound(a);
630 return types.isSubtype(a, bound);
631 } else if (a.isExtendsBound()) {
632 return types.isCastable(bound, types.wildUpperBound(a), types.noWarnings);
633 } else if (a.isSuperBound()) {
634 return !types.notSoftSubtype(types.wildLowerBound(a), bound);
635 }
636 return true;
637 }
638
639 /** Check that type is different from 'void'.
640 * @param pos Position to be used for error reporting.
641 * @param t The type to be checked.
642 */
643 Type checkNonVoid(DiagnosticPosition pos, Type t) {
644 if (t.hasTag(VOID)) {
645 log.error(pos, "void.not.allowed.here");
646 return types.createErrorType(t);
647 } else {
648 return t;
649 }
650 }
651
652 Type checkClassOrArrayType(DiagnosticPosition pos, Type t) {
653 if (!t.hasTag(CLASS) && !t.hasTag(ARRAY) && !t.hasTag(ERROR)) {
654 return typeTagError(pos,
655 diags.fragment("type.req.class.array"),
656 asTypeParam(t));
657 } else {
658 return t;
659 }
660 }
661
662 /** Check that type is a class or interface type.
663 * @param pos Position to be used for error reporting.
664 * @param t The type to be checked.
665 */
666 Type checkClassType(DiagnosticPosition pos, Type t) {
667 if (!t.hasTag(CLASS) && !t.hasTag(ERROR)) {
668 return typeTagError(pos,
669 diags.fragment("type.req.class"),
670 asTypeParam(t));
671 } else {
672 return t;
673 }
674 }
675 //where
676 private Object asTypeParam(Type t) {
677 return (t.hasTag(TYPEVAR))
678 ? diags.fragment("type.parameter", t)
679 : t;
680 }
681
682 /** Check that type is a valid qualifier for a constructor reference expression
683 */
684 Type checkConstructorRefType(DiagnosticPosition pos, Type t) {
685 t = checkClassOrArrayType(pos, t);
686 if (t.hasTag(CLASS)) {
687 if ((t.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
688 log.error(pos, "abstract.cant.be.instantiated", t.tsym);
689 t = types.createErrorType(t);
690 } else if ((t.tsym.flags() & ENUM) != 0) {
691 log.error(pos, "enum.cant.be.instantiated");
692 t = types.createErrorType(t);
693 } else {
694 t = checkClassType(pos, t, true);
695 }
696 } else if (t.hasTag(ARRAY)) {
697 if (!types.isReifiable(((ArrayType)t).elemtype)) {
698 log.error(pos, "generic.array.creation");
699 t = types.createErrorType(t);
700 }
701 }
702 return t;
703 }
704
705 /** Check that type is a class or interface type.
706 * @param pos Position to be used for error reporting.
707 * @param t The type to be checked.
708 * @param noBounds True if type bounds are illegal here.
709 */
710 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
711 t = checkClassType(pos, t);
712 if (noBounds && t.isParameterized()) {
713 List<Type> args = t.getTypeArguments();
714 while (args.nonEmpty()) {
715 if (args.head.hasTag(WILDCARD))
716 return typeTagError(pos,
717 diags.fragment("type.req.exact"),
718 args.head);
719 args = args.tail;
720 }
721 }
722 return t;
723 }
724
725 /** Check that type is a reference type, i.e. a class, interface or array type
726 * or a type variable.
727 * @param pos Position to be used for error reporting.
728 * @param t The type to be checked.
729 */
730 Type checkRefType(DiagnosticPosition pos, Type t) {
731 if (t.isReference())
732 return t;
733 else
734 return typeTagError(pos,
735 diags.fragment("type.req.ref"),
736 t);
737 }
738
739 /** Check that each type is a reference type, i.e. a class, interface or array type
740 * or a type variable.
741 * @param trees Original trees, used for error reporting.
742 * @param types The types to be checked.
743 */
744 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
745 List<JCExpression> tl = trees;
746 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
747 l.head = checkRefType(tl.head.pos(), l.head);
748 tl = tl.tail;
749 }
750 return types;
751 }
752
753 /** Check that type is a null or reference type.
754 * @param pos Position to be used for error reporting.
755 * @param t The type to be checked.
756 */
757 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
758 if (t.isReference() || t.hasTag(BOT))
759 return t;
760 else
761 return typeTagError(pos,
762 diags.fragment("type.req.ref"),
763 t);
764 }
765
766 /** Check that flag set does not contain elements of two conflicting sets. s
767 * Return true if it doesn't.
768 * @param pos Position to be used for error reporting.
769 * @param flags The set of flags to be checked.
770 * @param set1 Conflicting flags set #1.
771 * @param set2 Conflicting flags set #2.
772 */
773 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
774 if ((flags & set1) != 0 && (flags & set2) != 0) {
775 log.error(pos,
776 "illegal.combination.of.modifiers",
777 asFlagSet(TreeInfo.firstFlag(flags & set1)),
778 asFlagSet(TreeInfo.firstFlag(flags & set2)));
779 return false;
780 } else
781 return true;
782 }
783
784 /** Check that usage of diamond operator is correct (i.e. diamond should not
785 * be used with non-generic classes or in anonymous class creation expressions)
786 */
787 Type checkDiamond(JCNewClass tree, Type t) {
788 if (!TreeInfo.isDiamond(tree) ||
789 t.isErroneous()) {
790 return checkClassType(tree.clazz.pos(), t, true);
791 } else if (tree.def != null) {
792 log.error(tree.clazz.pos(),
793 "cant.apply.diamond.1",
794 t, diags.fragment("diamond.and.anon.class", t));
795 return types.createErrorType(t);
796 } else if (t.tsym.type.getTypeArguments().isEmpty()) {
797 log.error(tree.clazz.pos(),
798 "cant.apply.diamond.1",
799 t, diags.fragment("diamond.non.generic", t));
800 return types.createErrorType(t);
801 } else if (tree.typeargs != null &&
802 tree.typeargs.nonEmpty()) {
803 log.error(tree.clazz.pos(),
804 "cant.apply.diamond.1",
805 t, diags.fragment("diamond.and.explicit.params", t));
806 return types.createErrorType(t);
807 } else {
808 return t;
809 }
810 }
811
812 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
813 MethodSymbol m = tree.sym;
814 if (!allowSimplifiedVarargs) return;
815 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
816 Type varargElemType = null;
817 if (m.isVarArgs()) {
818 varargElemType = types.elemtype(tree.params.last().type);
819 }
820 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
821 if (varargElemType != null) {
822 log.error(tree,
823 "varargs.invalid.trustme.anno",
824 syms.trustMeType.tsym,
825 allowPrivateSafeVarargs ?
826 diags.fragment("varargs.trustme.on.virtual.varargs", m) :
827 diags.fragment("varargs.trustme.on.virtual.varargs.final.only", m));
828 } else {
829 log.error(tree,
830 "varargs.invalid.trustme.anno",
831 syms.trustMeType.tsym,
832 diags.fragment("varargs.trustme.on.non.varargs.meth", m));
833 }
834 } else if (hasTrustMeAnno && varargElemType != null &&
835 types.isReifiable(varargElemType)) {
836 warnUnsafeVararg(tree,
837 "varargs.redundant.trustme.anno",
838 syms.trustMeType.tsym,
839 diags.fragment("varargs.trustme.on.reifiable.varargs", varargElemType));
840 }
841 else if (!hasTrustMeAnno && varargElemType != null &&
842 !types.isReifiable(varargElemType)) {
843 warnUnchecked(tree.params.head.pos(), "unchecked.varargs.non.reifiable.type", varargElemType);
844 }
845 }
846 //where
847 private boolean isTrustMeAllowedOnMethod(Symbol s) {
848 return (s.flags() & VARARGS) != 0 &&
849 (s.isConstructor() ||
850 (s.flags() & (STATIC | FINAL |
851 (allowPrivateSafeVarargs ? PRIVATE : 0) )) != 0);
852 }
853
854 Type checkMethod(final Type mtype,
855 final Symbol sym,
856 final Env<AttrContext> env,
857 final List<JCExpression> argtrees,
858 final List<Type> argtypes,
859 final boolean useVarargs,
860 InferenceContext inferenceContext) {
861 // System.out.println("call : " + env.tree);
862 // System.out.println("method : " + owntype);
863 // System.out.println("actuals: " + argtypes);
864 if (inferenceContext.free(mtype)) {
865 inferenceContext.addFreeTypeListener(List.of(mtype), new FreeTypeListener() {
866 public void typesInferred(InferenceContext inferenceContext) {
867 checkMethod(inferenceContext.asInstType(mtype), sym, env, argtrees, argtypes, useVarargs, inferenceContext);
868 }
869 });
870 return mtype;
871 }
872 Type owntype = mtype;
873 List<Type> formals = owntype.getParameterTypes();
874 List<Type> nonInferred = sym.type.getParameterTypes();
875 if (nonInferred.length() != formals.length()) nonInferred = formals;
876 Type last = useVarargs ? formals.last() : null;
877 if (sym.name == names.init && sym.owner == syms.enumSym) {
878 formals = formals.tail.tail;
879 nonInferred = nonInferred.tail.tail;
880 }
881 List<JCExpression> args = argtrees;
882 if (args != null) {
883 //this is null when type-checking a method reference
884 while (formals.head != last) {
885 JCTree arg = args.head;
886 Warner warn = convertWarner(arg.pos(), arg.type, nonInferred.head);
887 assertConvertible(arg, arg.type, formals.head, warn);
888 args = args.tail;
889 formals = formals.tail;
890 nonInferred = nonInferred.tail;
891 }
892 if (useVarargs) {
893 Type varArg = types.elemtype(last);
894 while (args.tail != null) {
895 JCTree arg = args.head;
896 Warner warn = convertWarner(arg.pos(), arg.type, varArg);
897 assertConvertible(arg, arg.type, varArg, warn);
898 args = args.tail;
899 }
900 } else if ((sym.flags() & (VARARGS | SIGNATURE_POLYMORPHIC)) == VARARGS &&
901 allowVarargs) {
902 // non-varargs call to varargs method
903 Type varParam = owntype.getParameterTypes().last();
904 Type lastArg = argtypes.last();
905 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
906 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
907 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
908 types.elemtype(varParam), varParam);
909 }
910 }
911 if (useVarargs) {
912 Type argtype = owntype.getParameterTypes().last();
913 if (!types.isReifiable(argtype) &&
914 (!allowSimplifiedVarargs ||
915 sym.attribute(syms.trustMeType.tsym) == null ||
916 !isTrustMeAllowedOnMethod(sym))) {
917 warnUnchecked(env.tree.pos(),
918 "unchecked.generic.array.creation",
919 argtype);
920 }
921 if ((sym.baseSymbol().flags() & SIGNATURE_POLYMORPHIC) == 0) {
922 TreeInfo.setVarargsElement(env.tree, types.elemtype(argtype));
923 }
924 }
925 PolyKind pkind = (sym.type.hasTag(FORALL) &&
926 sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
927 PolyKind.POLY : PolyKind.STANDALONE;
928 TreeInfo.setPolyKind(env.tree, pkind);
929 return owntype;
930 }
931 //where
932 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
933 if (types.isConvertible(actual, formal, warn))
934 return;
935
936 if (formal.isCompound()
937 && types.isSubtype(actual, types.supertype(formal))
938 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
939 return;
940 }
941
942 /**
943 * Check that type 't' is a valid instantiation of a generic class
944 * (see JLS 4.5)
945 *
946 * @param t class type to be checked
947 * @return true if 't' is well-formed
948 */
949 public boolean checkValidGenericType(Type t) {
950 return firstIncompatibleTypeArg(t) == null;
951 }
952 //WHERE
953 private Type firstIncompatibleTypeArg(Type type) {
954 List<Type> formals = type.tsym.type.allparams();
955 List<Type> actuals = type.allparams();
956 List<Type> args = type.getTypeArguments();
957 List<Type> forms = type.tsym.type.getTypeArguments();
958 ListBuffer<Type> bounds_buf = new ListBuffer<>();
959
960 // For matching pairs of actual argument types `a' and
961 // formal type parameters with declared bound `b' ...
962 while (args.nonEmpty() && forms.nonEmpty()) {
963 // exact type arguments needs to know their
964 // bounds (for upper and lower bound
965 // calculations). So we create new bounds where
966 // type-parameters are replaced with actuals argument types.
967 bounds_buf.append(types.subst(forms.head.getUpperBound(), formals, actuals));
968 args = args.tail;
969 forms = forms.tail;
970 }
971
972 args = type.getTypeArguments();
973 List<Type> tvars_cap = types.substBounds(formals,
974 formals,
975 types.capture(type).allparams());
976 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
977 // Let the actual arguments know their bound
978 args.head.withTypeVar((TypeVar)tvars_cap.head);
979 args = args.tail;
980 tvars_cap = tvars_cap.tail;
981 }
982
983 args = type.getTypeArguments();
984 List<Type> bounds = bounds_buf.toList();
985
986 while (args.nonEmpty() && bounds.nonEmpty()) {
987 Type actual = args.head;
988 if (!isTypeArgErroneous(actual) &&
989 !bounds.head.isErroneous() &&
990 !checkExtends(actual, bounds.head)) {
991 return args.head;
992 }
993 args = args.tail;
994 bounds = bounds.tail;
995 }
996
997 args = type.getTypeArguments();
998 bounds = bounds_buf.toList();
999
1000 for (Type arg : types.capture(type).getTypeArguments()) {
1001 if (arg.hasTag(TYPEVAR) &&
1002 arg.getUpperBound().isErroneous() &&
1003 !bounds.head.isErroneous() &&
1004 !isTypeArgErroneous(args.head)) {
1005 return args.head;
1006 }
1007 bounds = bounds.tail;
1008 args = args.tail;
1009 }
1010
1011 return null;
1012 }
1013 //where
1014 boolean isTypeArgErroneous(Type t) {
1015 return isTypeArgErroneous.visit(t);
1016 }
1017
1018 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() {
1019 public Boolean visitType(Type t, Void s) {
1020 return t.isErroneous();
1021 }
1022 @Override
1023 public Boolean visitTypeVar(TypeVar t, Void s) {
1024 return visit(t.getUpperBound());
1025 }
1026 @Override
1027 public Boolean visitCapturedType(CapturedType t, Void s) {
1028 return visit(t.getUpperBound()) ||
1029 visit(t.getLowerBound());
1030 }
1031 @Override
1032 public Boolean visitWildcardType(WildcardType t, Void s) {
1033 return visit(t.type);
1034 }
1035 };
1036
1037 /** Check that given modifiers are legal for given symbol and
1038 * return modifiers together with any implicit modifiers for that symbol.
1039 * Warning: we can't use flags() here since this method
1040 * is called during class enter, when flags() would cause a premature
1041 * completion.
1042 * @param pos Position to be used for error reporting.
1043 * @param flags The set of modifiers given in a definition.
1044 * @param sym The defined symbol.
1045 */
1046 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
1047 long mask;
1048 long implicit = 0;
1049
1050 switch (sym.kind) {
1051 case VAR:
1052 if (TreeInfo.isReceiverParam(tree))
1053 mask = ReceiverParamFlags;
1054 else if (sym.owner.kind != TYP)
1055 mask = LocalVarFlags;
1056 else if ((sym.owner.flags_field & INTERFACE) != 0)
1057 mask = implicit = InterfaceVarFlags;
1058 else
1059 mask = VarFlags;
1060 break;
1061 case MTH:
1062 if (sym.name == names.init) {
1063 if ((sym.owner.flags_field & ENUM) != 0) {
1064 // enum constructors cannot be declared public or
1065 // protected and must be implicitly or explicitly
1066 // private
1067 implicit = PRIVATE;
1068 mask = PRIVATE;
1069 } else
1070 mask = ConstructorFlags;
1071 } else if ((sym.owner.flags_field & INTERFACE) != 0) {
1072 if ((sym.owner.flags_field & ANNOTATION) != 0) {
1073 mask = AnnotationTypeElementMask;
1074 implicit = PUBLIC | ABSTRACT;
1075 } else if ((flags & (DEFAULT | STATIC)) != 0) {
1076 mask = InterfaceMethodMask;
1077 implicit = PUBLIC;
1078 if ((flags & DEFAULT) != 0) {
1079 implicit |= ABSTRACT;
1080 }
1081 } else {
1082 mask = implicit = InterfaceMethodFlags;
1083 }
1084 } else {
1085 mask = MethodFlags;
1086 }
1087 // Imply STRICTFP if owner has STRICTFP set.
1088 if (((flags|implicit) & Flags.ABSTRACT) == 0 ||
1089 ((flags) & Flags.DEFAULT) != 0)
1090 implicit |= sym.owner.flags_field & STRICTFP;
1091 break;
1092 case TYP:
1093 if (sym.isLocal()) {
1094 mask = LocalClassFlags;
1095 if (sym.name.isEmpty()) { // Anonymous class
1096 // JLS: Anonymous classes are final.
1097 implicit |= FINAL;
1098 }
1099 if ((sym.owner.flags_field & STATIC) == 0 &&
1100 (flags & ENUM) != 0)
1101 log.error(pos, "enums.must.be.static");
1102 } else if (sym.owner.kind == TYP) {
1103 mask = MemberClassFlags;
1104 if (sym.owner.owner.kind == PCK ||
1105 (sym.owner.flags_field & STATIC) != 0)
1106 mask |= STATIC;
1107 else if ((flags & ENUM) != 0)
1108 log.error(pos, "enums.must.be.static");
1109 // Nested interfaces and enums are always STATIC (Spec ???)
1110 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
1111 } else {
1112 mask = ClassFlags;
1113 }
1114 // Interfaces are always ABSTRACT
1115 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
1116
1117 if ((flags & ENUM) != 0) {
1118 // enums can't be declared abstract or final
1119 mask &= ~(ABSTRACT | FINAL);
1120 implicit |= implicitEnumFinalFlag(tree);
1121 }
1122 // Imply STRICTFP if owner has STRICTFP set.
1123 implicit |= sym.owner.flags_field & STRICTFP;
1124 break;
1125 default:
1126 throw new AssertionError();
1127 }
1128 long illegal = flags & ExtendedStandardFlags & ~mask;
1129 if (illegal != 0) {
1130 if ((illegal & INTERFACE) != 0) {
1131 log.error(pos, "intf.not.allowed.here");
1132 mask |= INTERFACE;
1133 }
1134 else {
1135 log.error(pos,
1136 "mod.not.allowed.here", asFlagSet(illegal));
1137 }
1138 }
1139 else if ((sym.kind == TYP ||
1140 // ISSUE: Disallowing abstract&private is no longer appropriate
1141 // in the presence of inner classes. Should it be deleted here?
1142 checkDisjoint(pos, flags,
1143 ABSTRACT,
1144 PRIVATE | STATIC | DEFAULT))
1145 &&
1146 checkDisjoint(pos, flags,
1147 STATIC,
1148 DEFAULT)
1149 &&
1150 checkDisjoint(pos, flags,
1151 ABSTRACT | INTERFACE,
1152 FINAL | NATIVE | SYNCHRONIZED)
1153 &&
1154 checkDisjoint(pos, flags,
1155 PUBLIC,
1156 PRIVATE | PROTECTED)
1157 &&
1158 checkDisjoint(pos, flags,
1159 PRIVATE,
1160 PUBLIC | PROTECTED)
1161 &&
1162 checkDisjoint(pos, flags,
1163 FINAL,
1164 VOLATILE)
1165 &&
1166 (sym.kind == TYP ||
1167 checkDisjoint(pos, flags,
1168 ABSTRACT | NATIVE,
1169 STRICTFP))) {
1170 // skip
1171 }
1172 return flags & (mask | ~ExtendedStandardFlags) | implicit;
1173 }
1174
1175
1176 /** Determine if this enum should be implicitly final.
1177 *
1178 * If the enum has no specialized enum contants, it is final.
1179 *
1180 * If the enum does have specialized enum contants, it is
1181 * <i>not</i> final.
1182 */
1183 private long implicitEnumFinalFlag(JCTree tree) {
1184 if (!tree.hasTag(CLASSDEF)) return 0;
1185 class SpecialTreeVisitor extends JCTree.Visitor {
1186 boolean specialized;
1187 SpecialTreeVisitor() {
1188 this.specialized = false;
1189 }
1190
1191 @Override
1192 public void visitTree(JCTree tree) { /* no-op */ }
1193
1194 @Override
1195 public void visitVarDef(JCVariableDecl tree) {
1196 if ((tree.mods.flags & ENUM) != 0) {
1197 if (tree.init instanceof JCNewClass &&
1198 ((JCNewClass) tree.init).def != null) {
1199 specialized = true;
1200 }
1201 }
1202 }
1203 }
1204
1205 SpecialTreeVisitor sts = new SpecialTreeVisitor();
1206 JCClassDecl cdef = (JCClassDecl) tree;
1207 for (JCTree defs: cdef.defs) {
1208 defs.accept(sts);
1209 if (sts.specialized) return 0;
1210 }
1211 return FINAL;
1212 }
1213
1214 /* *************************************************************************
1215 * Type Validation
1216 **************************************************************************/
1217
1218 /** Validate a type expression. That is,
1219 * check that all type arguments of a parametric type are within
1220 * their bounds. This must be done in a second phase after type attribution
1221 * since a class might have a subclass as type parameter bound. E.g:
1222 *
1223 * <pre>{@code
1224 * class B<A extends C> { ... }
1225 * class C extends B<C> { ... }
1226 * }</pre>
1227 *
1228 * and we can't make sure that the bound is already attributed because
1229 * of possible cycles.
1230 *
1231 * Visitor method: Validate a type expression, if it is not null, catching
1232 * and reporting any completion failures.
1233 */
1234 void validate(JCTree tree, Env<AttrContext> env) {
1235 validate(tree, env, true);
1236 }
1237 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1238 new Validator(env).validateTree(tree, checkRaw, true);
1239 }
1240
1241 /** Visitor method: Validate a list of type expressions.
1242 */
1243 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1244 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1245 validate(l.head, env);
1246 }
1247
1248 /** A visitor class for type validation.
1249 */
1250 class Validator extends JCTree.Visitor {
1251
1252 boolean checkRaw;
1253 boolean isOuter;
1254 Env<AttrContext> env;
1255
1256 Validator(Env<AttrContext> env) {
1257 this.env = env;
1258 }
1259
1260 @Override
1261 public void visitTypeArray(JCArrayTypeTree tree) {
1262 validateTree(tree.elemtype, checkRaw, isOuter);
1263 }
1264
1265 @Override
1266 public void visitTypeApply(JCTypeApply tree) {
1267 if (tree.type.hasTag(CLASS)) {
1268 List<JCExpression> args = tree.arguments;
1269 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1270
1271 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1272 if (incompatibleArg != null) {
1273 for (JCTree arg : tree.arguments) {
1274 if (arg.type == incompatibleArg) {
1275 log.error(arg, "not.within.bounds", incompatibleArg, forms.head);
1276 }
1277 forms = forms.tail;
1278 }
1279 }
1280
1281 forms = tree.type.tsym.type.getTypeArguments();
1282
1283 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1284
1285 // For matching pairs of actual argument types `a' and
1286 // formal type parameters with declared bound `b' ...
1287 while (args.nonEmpty() && forms.nonEmpty()) {
1288 validateTree(args.head,
1289 !(isOuter && is_java_lang_Class),
1290 false);
1291 args = args.tail;
1292 forms = forms.tail;
1293 }
1294
1295 // Check that this type is either fully parameterized, or
1296 // not parameterized at all.
1297 if (tree.type.getEnclosingType().isRaw())
1298 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
1299 if (tree.clazz.hasTag(SELECT))
1300 visitSelectInternal((JCFieldAccess)tree.clazz);
1301 }
1302 }
1303
1304 @Override
1305 public void visitTypeParameter(JCTypeParameter tree) {
1306 validateTrees(tree.bounds, true, isOuter);
1307 checkClassBounds(tree.pos(), tree.type);
1308 }
1309
1310 @Override
1311 public void visitWildcard(JCWildcard tree) {
1312 if (tree.inner != null)
1313 validateTree(tree.inner, true, isOuter);
1314 }
1315
1316 @Override
1317 public void visitSelect(JCFieldAccess tree) {
1318 if (tree.type.hasTag(CLASS)) {
1319 visitSelectInternal(tree);
1320
1321 // Check that this type is either fully parameterized, or
1322 // not parameterized at all.
1323 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1324 log.error(tree.pos(), "improperly.formed.type.param.missing");
1325 }
1326 }
1327
1328 public void visitSelectInternal(JCFieldAccess tree) {
1329 if (tree.type.tsym.isStatic() &&
1330 tree.selected.type.isParameterized()) {
1331 // The enclosing type is not a class, so we are
1332 // looking at a static member type. However, the
1333 // qualifying expression is parameterized.
1334 log.error(tree.pos(), "cant.select.static.class.from.param.type");
1335 } else {
1336 // otherwise validate the rest of the expression
1337 tree.selected.accept(this);
1338 }
1339 }
1340
1341 @Override
1342 public void visitAnnotatedType(JCAnnotatedType tree) {
1343 tree.underlyingType.accept(this);
1344 }
1345
1346 @Override
1347 public void visitTypeIdent(JCPrimitiveTypeTree that) {
1348 if (that.type.hasTag(TypeTag.VOID)) {
1349 log.error(that.pos(), "void.not.allowed.here");
1350 }
1351 super.visitTypeIdent(that);
1352 }
1353
1354 /** Default visitor method: do nothing.
1355 */
1356 @Override
1357 public void visitTree(JCTree tree) {
1358 }
1359
1360 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1361 if (tree != null) {
1362 boolean prevCheckRaw = this.checkRaw;
1363 this.checkRaw = checkRaw;
1364 this.isOuter = isOuter;
1365
1366 try {
1367 tree.accept(this);
1368 if (checkRaw)
1369 checkRaw(tree, env);
1370 } catch (CompletionFailure ex) {
1371 completionError(tree.pos(), ex);
1372 } finally {
1373 this.checkRaw = prevCheckRaw;
1374 }
1375 }
1376 }
1377
1378 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1379 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1380 validateTree(l.head, checkRaw, isOuter);
1381 }
1382 }
1383
1384 void checkRaw(JCTree tree, Env<AttrContext> env) {
1385 if (lint.isEnabled(LintCategory.RAW) &&
1386 tree.type.hasTag(CLASS) &&
1387 !TreeInfo.isDiamond(tree) &&
1388 !withinAnonConstr(env) &&
1389 tree.type.isRaw()) {
1390 log.warning(LintCategory.RAW,
1391 tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
1392 }
1393 }
1394 //where
1395 private boolean withinAnonConstr(Env<AttrContext> env) {
1396 return env.enclClass.name.isEmpty() &&
1397 env.enclMethod != null && env.enclMethod.name == names.init;
1398 }
1399
1400 /* *************************************************************************
1401 * Exception checking
1402 **************************************************************************/
1403
1404 /* The following methods treat classes as sets that contain
1405 * the class itself and all their subclasses
1406 */
1407
1408 /** Is given type a subtype of some of the types in given list?
1409 */
1410 boolean subset(Type t, List<Type> ts) {
1411 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1412 if (types.isSubtype(t, l.head)) return true;
1413 return false;
1414 }
1415
1416 /** Is given type a subtype or supertype of
1417 * some of the types in given list?
1418 */
1419 boolean intersects(Type t, List<Type> ts) {
1420 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1421 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1422 return false;
1423 }
1424
1425 /** Add type set to given type list, unless it is a subclass of some class
1426 * in the list.
1427 */
1428 List<Type> incl(Type t, List<Type> ts) {
1429 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1430 }
1431
1432 /** Remove type set from type set list.
1433 */
1434 List<Type> excl(Type t, List<Type> ts) {
1435 if (ts.isEmpty()) {
1436 return ts;
1437 } else {
1438 List<Type> ts1 = excl(t, ts.tail);
1439 if (types.isSubtype(ts.head, t)) return ts1;
1440 else if (ts1 == ts.tail) return ts;
1441 else return ts1.prepend(ts.head);
1442 }
1443 }
1444
1445 /** Form the union of two type set lists.
1446 */
1447 List<Type> union(List<Type> ts1, List<Type> ts2) {
1448 List<Type> ts = ts1;
1449 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1450 ts = incl(l.head, ts);
1451 return ts;
1452 }
1453
1454 /** Form the difference of two type lists.
1455 */
1456 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1457 List<Type> ts = ts1;
1458 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1459 ts = excl(l.head, ts);
1460 return ts;
1461 }
1462
1463 /** Form the intersection of two type lists.
1464 */
1465 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1466 List<Type> ts = List.nil();
1467 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1468 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1469 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1470 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1471 return ts;
1472 }
1473
1474 /** Is exc an exception symbol that need not be declared?
1475 */
1476 boolean isUnchecked(ClassSymbol exc) {
1477 return
1478 exc.kind == ERR ||
1479 exc.isSubClass(syms.errorType.tsym, types) ||
1480 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1481 }
1482
1483 /** Is exc an exception type that need not be declared?
1484 */
1485 boolean isUnchecked(Type exc) {
1486 return
1487 (exc.hasTag(TYPEVAR)) ? isUnchecked(types.supertype(exc)) :
1488 (exc.hasTag(CLASS)) ? isUnchecked((ClassSymbol)exc.tsym) :
1489 exc.hasTag(BOT);
1490 }
1491
1492 /** Same, but handling completion failures.
1493 */
1494 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1495 try {
1496 return isUnchecked(exc);
1497 } catch (CompletionFailure ex) {
1498 completionError(pos, ex);
1499 return true;
1500 }
1501 }
1502
1503 /** Is exc handled by given exception list?
1504 */
1505 boolean isHandled(Type exc, List<Type> handled) {
1506 return isUnchecked(exc) || subset(exc, handled);
1507 }
1508
1509 /** Return all exceptions in thrown list that are not in handled list.
1510 * @param thrown The list of thrown exceptions.
1511 * @param handled The list of handled exceptions.
1512 */
1513 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1514 List<Type> unhandled = List.nil();
1515 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1516 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1517 return unhandled;
1518 }
1519
1520 /* *************************************************************************
1521 * Overriding/Implementation checking
1522 **************************************************************************/
1523
1524 /** The level of access protection given by a flag set,
1525 * where PRIVATE is highest and PUBLIC is lowest.
1526 */
1527 static int protection(long flags) {
1528 switch ((short)(flags & AccessFlags)) {
1529 case PRIVATE: return 3;
1530 case PROTECTED: return 1;
1531 default:
1532 case PUBLIC: return 0;
1533 case 0: return 2;
1534 }
1535 }
1536
1537 /** A customized "cannot override" error message.
1538 * @param m The overriding method.
1539 * @param other The overridden method.
1540 * @return An internationalized string.
1541 */
1542 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1543 String key;
1544 if ((other.owner.flags() & INTERFACE) == 0)
1545 key = "cant.override";
1546 else if ((m.owner.flags() & INTERFACE) == 0)
1547 key = "cant.implement";
1548 else
1549 key = "clashes.with";
1550 return diags.fragment(key, m, m.location(), other, other.location());
1551 }
1552
1553 /** A customized "override" warning message.
1554 * @param m The overriding method.
1555 * @param other The overridden method.
1556 * @return An internationalized string.
1557 */
1558 Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1559 String key;
1560 if ((other.owner.flags() & INTERFACE) == 0)
1561 key = "unchecked.override";
1562 else if ((m.owner.flags() & INTERFACE) == 0)
1563 key = "unchecked.implement";
1564 else
1565 key = "unchecked.clash.with";
1566 return diags.fragment(key, m, m.location(), other, other.location());
1567 }
1568
1569 /** A customized "override" warning message.
1570 * @param m The overriding method.
1571 * @param other The overridden method.
1572 * @return An internationalized string.
1573 */
1574 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1575 String key;
1576 if ((other.owner.flags() & INTERFACE) == 0)
1577 key = "varargs.override";
1578 else if ((m.owner.flags() & INTERFACE) == 0)
1579 key = "varargs.implement";
1580 else
1581 key = "varargs.clash.with";
1582 return diags.fragment(key, m, m.location(), other, other.location());
1583 }
1584
1585 /** Check that this method conforms with overridden method 'other'.
1586 * where `origin' is the class where checking started.
1587 * Complications:
1588 * (1) Do not check overriding of synthetic methods
1589 * (reason: they might be final).
1590 * todo: check whether this is still necessary.
1591 * (2) Admit the case where an interface proxy throws fewer exceptions
1592 * than the method it implements. Augment the proxy methods with the
1593 * undeclared exceptions in this case.
1594 * (3) When generics are enabled, admit the case where an interface proxy
1595 * has a result type
1596 * extended by the result type of the method it implements.
1597 * Change the proxies result type to the smaller type in this case.
1598 *
1599 * @param tree The tree from which positions
1600 * are extracted for errors.
1601 * @param m The overriding method.
1602 * @param other The overridden method.
1603 * @param origin The class of which the overriding method
1604 * is a member.
1605 */
1606 void checkOverride(JCTree tree,
1607 MethodSymbol m,
1608 MethodSymbol other,
1609 ClassSymbol origin) {
1610 // Don't check overriding of synthetic methods or by bridge methods.
1611 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1612 return;
1613 }
1614
1615 // Error if static method overrides instance method (JLS 8.4.6.2).
1616 if ((m.flags() & STATIC) != 0 &&
1617 (other.flags() & STATIC) == 0) {
1618 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1619 cannotOverride(m, other));
1620 m.flags_field |= BAD_OVERRIDE;
1621 return;
1622 }
1623
1624 // Error if instance method overrides static or final
1625 // method (JLS 8.4.6.1).
1626 if ((other.flags() & FINAL) != 0 ||
1627 (m.flags() & STATIC) == 0 &&
1628 (other.flags() & STATIC) != 0) {
1629 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1630 cannotOverride(m, other),
1631 asFlagSet(other.flags() & (FINAL | STATIC)));
1632 m.flags_field |= BAD_OVERRIDE;
1633 return;
1634 }
1635
1636 if ((m.owner.flags() & ANNOTATION) != 0) {
1637 // handled in validateAnnotationMethod
1638 return;
1639 }
1640
1641 // Error if overriding method has weaker access (JLS 8.4.6.3).
1642 if ((origin.flags() & INTERFACE) == 0 &&
1643 protection(m.flags()) > protection(other.flags())) {
1644 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1645 cannotOverride(m, other),
1646 (other.flags() & AccessFlags) == 0 ?
1647 "package" :
1648 asFlagSet(other.flags() & AccessFlags));
1649 m.flags_field |= BAD_OVERRIDE;
1650 return;
1651 }
1652
1653 Type mt = types.memberType(origin.type, m);
1654 Type ot = types.memberType(origin.type, other);
1655 // Error if overriding result type is different
1656 // (or, in the case of generics mode, not a subtype) of
1657 // overridden result type. We have to rename any type parameters
1658 // before comparing types.
1659 List<Type> mtvars = mt.getTypeArguments();
1660 List<Type> otvars = ot.getTypeArguments();
1661 Type mtres = mt.getReturnType();
1662 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1663
1664 overrideWarner.clear();
1665 boolean resultTypesOK =
1666 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1667 if (!resultTypesOK) {
1668 if (!allowCovariantReturns &&
1669 m.owner != origin &&
1670 m.owner.isSubClass(other.owner, types)) {
1671 // allow limited interoperability with covariant returns
1672 } else {
1673 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1674 "override.incompatible.ret",
1675 cannotOverride(m, other),
1676 mtres, otres);
1677 m.flags_field |= BAD_OVERRIDE;
1678 return;
1679 }
1680 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1681 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1682 "override.unchecked.ret",
1683 uncheckedOverrides(m, other),
1684 mtres, otres);
1685 }
1686
1687 // Error if overriding method throws an exception not reported
1688 // by overridden method.
1689 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1690 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1691 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1692 if (unhandledErased.nonEmpty()) {
1693 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1694 "override.meth.doesnt.throw",
1695 cannotOverride(m, other),
1696 unhandledUnerased.head);
1697 m.flags_field |= BAD_OVERRIDE;
1698 return;
1699 }
1700 else if (unhandledUnerased.nonEmpty()) {
1701 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1702 "override.unchecked.thrown",
1703 cannotOverride(m, other),
1704 unhandledUnerased.head);
1705 return;
1706 }
1707
1708 // Optional warning if varargs don't agree
1709 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1710 && lint.isEnabled(LintCategory.OVERRIDES)) {
1711 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1712 ((m.flags() & Flags.VARARGS) != 0)
1713 ? "override.varargs.missing"
1714 : "override.varargs.extra",
1715 varargsOverrides(m, other));
1716 }
1717
1718 // Warn if instance method overrides bridge method (compiler spec ??)
1719 if ((other.flags() & BRIDGE) != 0) {
1720 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1721 uncheckedOverrides(m, other));
1722 }
1723
1724 // Warn if a deprecated method overridden by a non-deprecated one.
1725 if (!isDeprecatedOverrideIgnorable(other, origin)) {
1726 Lint prevLint = setLint(lint.augment(m));
1727 try {
1728 checkDeprecated(TreeInfo.diagnosticPositionFor(m, tree), m, other);
1729 } finally {
1730 setLint(prevLint);
1731 }
1732 }
1733 }
1734 // where
1735 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1736 // If the method, m, is defined in an interface, then ignore the issue if the method
1737 // is only inherited via a supertype and also implemented in the supertype,
1738 // because in that case, we will rediscover the issue when examining the method
1739 // in the supertype.
1740 // If the method, m, is not defined in an interface, then the only time we need to
1741 // address the issue is when the method is the supertype implemementation: any other
1742 // case, we will have dealt with when examining the supertype classes
1743 ClassSymbol mc = m.enclClass();
1744 Type st = types.supertype(origin.type);
1745 if (!st.hasTag(CLASS))
1746 return true;
1747 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1748
1749 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1750 List<Type> intfs = types.interfaces(origin.type);
1751 return (intfs.contains(mc.type) ? false : (stimpl != null));
1752 }
1753 else
1754 return (stimpl != m);
1755 }
1756
1757
1758 // used to check if there were any unchecked conversions
1759 Warner overrideWarner = new Warner();
1760
1761 /** Check that a class does not inherit two concrete methods
1762 * with the same signature.
1763 * @param pos Position to be used for error reporting.
1764 * @param site The class type to be checked.
1765 */
1766 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1767 Type sup = types.supertype(site);
1768 if (!sup.hasTag(CLASS)) return;
1769
1770 for (Type t1 = sup;
1771 t1.hasTag(CLASS) && t1.tsym.type.isParameterized();
1772 t1 = types.supertype(t1)) {
1773 for (Scope.Entry e1 = t1.tsym.members().elems;
1774 e1 != null;
1775 e1 = e1.sibling) {
1776 Symbol s1 = e1.sym;
1777 if (s1.kind != MTH ||
1778 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1779 !s1.isInheritedIn(site.tsym, types) ||
1780 ((MethodSymbol)s1).implementation(site.tsym,
1781 types,
1782 true) != s1)
1783 continue;
1784 Type st1 = types.memberType(t1, s1);
1785 int s1ArgsLength = st1.getParameterTypes().length();
1786 if (st1 == s1.type) continue;
1787
1788 for (Type t2 = sup;
1789 t2.hasTag(CLASS);
1790 t2 = types.supertype(t2)) {
1791 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1792 e2.scope != null;
1793 e2 = e2.next()) {
1794 Symbol s2 = e2.sym;
1795 if (s2 == s1 ||
1796 s2.kind != MTH ||
1797 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1798 s2.type.getParameterTypes().length() != s1ArgsLength ||
1799 !s2.isInheritedIn(site.tsym, types) ||
1800 ((MethodSymbol)s2).implementation(site.tsym,
1801 types,
1802 true) != s2)
1803 continue;
1804 Type st2 = types.memberType(t2, s2);
1805 if (types.overrideEquivalent(st1, st2))
1806 log.error(pos, "concrete.inheritance.conflict",
1807 s1, t1, s2, t2, sup);
1808 }
1809 }
1810 }
1811 }
1812 }
1813
1814 /** Check that classes (or interfaces) do not each define an abstract
1815 * method with same name and arguments but incompatible return types.
1816 * @param pos Position to be used for error reporting.
1817 * @param t1 The first argument type.
1818 * @param t2 The second argument type.
1819 */
1820 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1821 Type t1,
1822 Type t2) {
1823 return checkCompatibleAbstracts(pos, t1, t2,
1824 types.makeCompoundType(t1, t2));
1825 }
1826
1827 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1828 Type t1,
1829 Type t2,
1830 Type site) {
1831 if ((site.tsym.flags() & COMPOUND) != 0) {
1832 // special case for intersections: need to eliminate wildcards in supertypes
1833 t1 = types.capture(t1);
1834 t2 = types.capture(t2);
1835 }
1836 return firstIncompatibility(pos, t1, t2, site) == null;
1837 }
1838
1839 /** Return the first method which is defined with same args
1840 * but different return types in two given interfaces, or null if none
1841 * exists.
1842 * @param t1 The first type.
1843 * @param t2 The second type.
1844 * @param site The most derived type.
1845 * @returns symbol from t2 that conflicts with one in t1.
1846 */
1847 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1848 Map<TypeSymbol,Type> interfaces1 = new HashMap<>();
1849 closure(t1, interfaces1);
1850 Map<TypeSymbol,Type> interfaces2;
1851 if (t1 == t2)
1852 interfaces2 = interfaces1;
1853 else
1854 closure(t2, interfaces1, interfaces2 = new HashMap<>());
1855
1856 for (Type t3 : interfaces1.values()) {
1857 for (Type t4 : interfaces2.values()) {
1858 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
1859 if (s != null) return s;
1860 }
1861 }
1862 return null;
1863 }
1864
1865 /** Compute all the supertypes of t, indexed by type symbol. */
1866 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1867 if (!t.hasTag(CLASS)) return;
1868 if (typeMap.put(t.tsym, t) == null) {
1869 closure(types.supertype(t), typeMap);
1870 for (Type i : types.interfaces(t))
1871 closure(i, typeMap);
1872 }
1873 }
1874
1875 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1876 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1877 if (!t.hasTag(CLASS)) return;
1878 if (typesSkip.get(t.tsym) != null) return;
1879 if (typeMap.put(t.tsym, t) == null) {
1880 closure(types.supertype(t), typesSkip, typeMap);
1881 for (Type i : types.interfaces(t))
1882 closure(i, typesSkip, typeMap);
1883 }
1884 }
1885
1886 /** Return the first method in t2 that conflicts with a method from t1. */
1887 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1888 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1889 Symbol s1 = e1.sym;
1890 Type st1 = null;
1891 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types) ||
1892 (s1.flags() & SYNTHETIC) != 0) continue;
1893 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1894 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1895 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1896 Symbol s2 = e2.sym;
1897 if (s1 == s2) continue;
1898 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types) ||
1899 (s2.flags() & SYNTHETIC) != 0) continue;
1900 if (st1 == null) st1 = types.memberType(t1, s1);
1901 Type st2 = types.memberType(t2, s2);
1902 if (types.overrideEquivalent(st1, st2)) {
1903 List<Type> tvars1 = st1.getTypeArguments();
1904 List<Type> tvars2 = st2.getTypeArguments();
1905 Type rt1 = st1.getReturnType();
1906 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1907 boolean compat =
1908 types.isSameType(rt1, rt2) ||
1909 !rt1.isPrimitiveOrVoid() &&
1910 !rt2.isPrimitiveOrVoid() &&
1911 (types.covariantReturnType(rt1, rt2, types.noWarnings) ||
1912 types.covariantReturnType(rt2, rt1, types.noWarnings)) ||
1913 checkCommonOverriderIn(s1,s2,site);
1914 if (!compat) {
1915 log.error(pos, "types.incompatible.diff.ret",
1916 t1, t2, s2.name +
1917 "(" + types.memberType(t2, s2).getParameterTypes() + ")");
1918 return s2;
1919 }
1920 } else if (checkNameClash((ClassSymbol)site.tsym, s1, s2) &&
1921 !checkCommonOverriderIn(s1, s2, site)) {
1922 log.error(pos,
1923 "name.clash.same.erasure.no.override",
1924 s1, s1.location(),
1925 s2, s2.location());
1926 return s2;
1927 }
1928 }
1929 }
1930 return null;
1931 }
1932 //WHERE
1933 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1934 Map<TypeSymbol,Type> supertypes = new HashMap<>();
1935 Type st1 = types.memberType(site, s1);
1936 Type st2 = types.memberType(site, s2);
1937 closure(site, supertypes);
1938 for (Type t : supertypes.values()) {
1939 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1940 Symbol s3 = e.sym;
1941 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1942 Type st3 = types.memberType(site,s3);
1943 if (types.overrideEquivalent(st3, st1) &&
1944 types.overrideEquivalent(st3, st2) &&
1945 types.returnTypeSubstitutable(st3, st1) &&
1946 types.returnTypeSubstitutable(st3, st2)) {
1947 return true;
1948 }
1949 }
1950 }
1951 return false;
1952 }
1953
1954 /** Check that a given method conforms with any method it overrides.
1955 * @param tree The tree from which positions are extracted
1956 * for errors.
1957 * @param m The overriding method.
1958 */
1959 void checkOverride(JCMethodDecl tree, MethodSymbol m) {
1960 ClassSymbol origin = (ClassSymbol)m.owner;
1961 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1962 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1963 log.error(tree.pos(), "enum.no.finalize");
1964 return;
1965 }
1966 for (Type t = origin.type; t.hasTag(CLASS);
1967 t = types.supertype(t)) {
1968 if (t != origin.type) {
1969 checkOverride(tree, t, origin, m);
1970 }
1971 for (Type t2 : types.interfaces(t)) {
1972 checkOverride(tree, t2, origin, m);
1973 }
1974 }
1975
1976 if (m.attribute(syms.overrideType.tsym) != null && !isOverrider(m)) {
1977 DiagnosticPosition pos = tree.pos();
1978 for (JCAnnotation a : tree.getModifiers().annotations) {
1979 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
1980 pos = a.pos();
1981 break;
1982 }
1983 }
1984 log.error(pos, "method.does.not.override.superclass");
1985 }
1986 }
1987
1988 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
1989 TypeSymbol c = site.tsym;
1990 Scope.Entry e = c.members().lookup(m.name);
1991 while (e.scope != null) {
1992 if (m.overrides(e.sym, origin, types, false)) {
1993 if ((e.sym.flags() & ABSTRACT) == 0) {
1994 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1995 }
1996 }
1997 e = e.next();
1998 }
1999 }
2000
2001 private Filter<Symbol> equalsHasCodeFilter = new Filter<Symbol>() {
2002 public boolean accepts(Symbol s) {
2003 return MethodSymbol.implementation_filter.accepts(s) &&
2004 (s.flags() & BAD_OVERRIDE) == 0;
2005
2006 }
2007 };
2008
2009 public void checkClassOverrideEqualsAndHashIfNeeded(DiagnosticPosition pos,
2010 ClassSymbol someClass) {
2011 /* At present, annotations cannot possibly have a method that is override
2012 * equivalent with Object.equals(Object) but in any case the condition is
2013 * fine for completeness.
2014 */
2015 if (someClass == (ClassSymbol)syms.objectType.tsym ||
2016 someClass.isInterface() || someClass.isEnum() ||
2017 (someClass.flags() & ANNOTATION) != 0 ||
2018 (someClass.flags() & ABSTRACT) != 0) return;
2019 //anonymous inner classes implementing interfaces need especial treatment
2020 if (someClass.isAnonymous()) {
2021 List<Type> interfaces = types.interfaces(someClass.type);
2022 if (interfaces != null && !interfaces.isEmpty() &&
2023 interfaces.head.tsym == syms.comparatorType.tsym) return;
2024 }
2025 checkClassOverrideEqualsAndHash(pos, someClass);
2026 }
2027
2028 private void checkClassOverrideEqualsAndHash(DiagnosticPosition pos,
2029 ClassSymbol someClass) {
2030 if (lint.isEnabled(LintCategory.OVERRIDES)) {
2031 MethodSymbol equalsAtObject = (MethodSymbol)syms.objectType
2032 .tsym.members().lookup(names.equals).sym;
2033 MethodSymbol hashCodeAtObject = (MethodSymbol)syms.objectType
2034 .tsym.members().lookup(names.hashCode).sym;
2035 boolean overridesEquals = types.implementation(equalsAtObject,
2036 someClass, false, equalsHasCodeFilter).owner == someClass;
2037 boolean overridesHashCode = types.implementation(hashCodeAtObject,
2038 someClass, false, equalsHasCodeFilter) != hashCodeAtObject;
2039
2040 if (overridesEquals && !overridesHashCode) {
2041 log.warning(LintCategory.OVERRIDES, pos,
2042 "override.equals.but.not.hashcode", someClass);
2043 }
2044 }
2045 }
2046
2047 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
2048 ClashFilter cf = new ClashFilter(origin.type);
2049 return (cf.accepts(s1) &&
2050 cf.accepts(s2) &&
2051 types.hasSameArgs(s1.erasure(types), s2.erasure(types)));
2052 }
2053
2054
2055 /** Check that all abstract members of given class have definitions.
2056 * @param pos Position to be used for error reporting.
2057 * @param c The class.
2058 */
2059 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
2060 try {
2061 MethodSymbol undef = firstUndef(c, c);
2062 if (undef != null) {
2063 if ((c.flags() & ENUM) != 0 &&
2064 types.supertype(c.type).tsym == syms.enumSym &&
2065 (c.flags() & FINAL) == 0) {
2066 // add the ABSTRACT flag to an enum
2067 c.flags_field |= ABSTRACT;
2068 } else {
2069 MethodSymbol undef1 =
2070 new MethodSymbol(undef.flags(), undef.name,
2071 types.memberType(c.type, undef), undef.owner);
2072 log.error(pos, "does.not.override.abstract",
2073 c, undef1, undef1.location());
2074 }
2075 }
2076 } catch (CompletionFailure ex) {
2077 completionError(pos, ex);
2078 }
2079 }
2080 //where
2081 /** Return first abstract member of class `c' that is not defined
2082 * in `impl', null if there is none.
2083 */
2084 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
2085 MethodSymbol undef = null;
2086 // Do not bother to search in classes that are not abstract,
2087 // since they cannot have abstract members.
2088 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
2089 Scope s = c.members();
2090 for (Scope.Entry e = s.elems;
2091 undef == null && e != null;
2092 e = e.sibling) {
2093 if (e.sym.kind == MTH &&
2094 (e.sym.flags() & (ABSTRACT|IPROXY|DEFAULT)) == ABSTRACT) {
2095 MethodSymbol absmeth = (MethodSymbol)e.sym;
2096 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
2097 if (implmeth == null || implmeth == absmeth) {
2098 //look for default implementations
2099 if (allowDefaultMethods) {
2100 MethodSymbol prov = types.interfaceCandidates(impl.type, absmeth).head;
2101 if (prov != null && prov.overrides(absmeth, impl, types, true)) {
2102 implmeth = prov;
2103 }
2104 }
2105 }
2106 if (implmeth == null || implmeth == absmeth) {
2107 undef = absmeth;
2108 }
2109 }
2110 }
2111 if (undef == null) {
2112 Type st = types.supertype(c.type);
2113 if (st.hasTag(CLASS))
2114 undef = firstUndef(impl, (ClassSymbol)st.tsym);
2115 }
2116 for (List<Type> l = types.interfaces(c.type);
2117 undef == null && l.nonEmpty();
2118 l = l.tail) {
2119 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
2120 }
2121 }
2122 return undef;
2123 }
2124
2125 void checkNonCyclicDecl(JCClassDecl tree) {
2126 CycleChecker cc = new CycleChecker();
2127 cc.scan(tree);
2128 if (!cc.errorFound && !cc.partialCheck) {
2129 tree.sym.flags_field |= ACYCLIC;
2130 }
2131 }
2132
2133 class CycleChecker extends TreeScanner {
2134
2135 List<Symbol> seenClasses = List.nil();
2136 boolean errorFound = false;
2137 boolean partialCheck = false;
2138
2139 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
2140 if (sym != null && sym.kind == TYP) {
2141 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
2142 if (classEnv != null) {
2143 DiagnosticSource prevSource = log.currentSource();
2144 try {
2145 log.useSource(classEnv.toplevel.sourcefile);
2146 scan(classEnv.tree);
2147 }
2148 finally {
2149 log.useSource(prevSource.getFile());
2150 }
2151 } else if (sym.kind == TYP) {
2152 checkClass(pos, sym, List.<JCTree>nil());
2153 }
2154 } else {
2155 //not completed yet
2156 partialCheck = true;
2157 }
2158 }
2159
2160 @Override
2161 public void visitSelect(JCFieldAccess tree) {
2162 super.visitSelect(tree);
2163 checkSymbol(tree.pos(), tree.sym);
2164 }
2165
2166 @Override
2167 public void visitIdent(JCIdent tree) {
2168 checkSymbol(tree.pos(), tree.sym);
2169 }
2170
2171 @Override
2172 public void visitTypeApply(JCTypeApply tree) {
2173 scan(tree.clazz);
2174 }
2175
2176 @Override
2177 public void visitTypeArray(JCArrayTypeTree tree) {
2178 scan(tree.elemtype);
2179 }
2180
2181 @Override
2182 public void visitClassDef(JCClassDecl tree) {
2183 List<JCTree> supertypes = List.nil();
2184 if (tree.getExtendsClause() != null) {
2185 supertypes = supertypes.prepend(tree.getExtendsClause());
2186 }
2187 if (tree.getImplementsClause() != null) {
2188 for (JCTree intf : tree.getImplementsClause()) {
2189 supertypes = supertypes.prepend(intf);
2190 }
2191 }
2192 checkClass(tree.pos(), tree.sym, supertypes);
2193 }
2194
2195 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
2196 if ((c.flags_field & ACYCLIC) != 0)
2197 return;
2198 if (seenClasses.contains(c)) {
2199 errorFound = true;
2200 noteCyclic(pos, (ClassSymbol)c);
2201 } else if (!c.type.isErroneous()) {
2202 try {
2203 seenClasses = seenClasses.prepend(c);
2204 if (c.type.hasTag(CLASS)) {
2205 if (supertypes.nonEmpty()) {
2206 scan(supertypes);
2207 }
2208 else {
2209 ClassType ct = (ClassType)c.type;
2210 if (ct.supertype_field == null ||
2211 ct.interfaces_field == null) {
2212 //not completed yet
2213 partialCheck = true;
2214 return;
2215 }
2216 checkSymbol(pos, ct.supertype_field.tsym);
2217 for (Type intf : ct.interfaces_field) {
2218 checkSymbol(pos, intf.tsym);
2219 }
2220 }
2221 if (c.owner.kind == TYP) {
2222 checkSymbol(pos, c.owner);
2223 }
2224 }
2225 } finally {
2226 seenClasses = seenClasses.tail;
2227 }
2228 }
2229 }
2230 }
2231
2232 /** Check for cyclic references. Issue an error if the
2233 * symbol of the type referred to has a LOCKED flag set.
2234 *
2235 * @param pos Position to be used for error reporting.
2236 * @param t The type referred to.
2237 */
2238 void checkNonCyclic(DiagnosticPosition pos, Type t) {
2239 checkNonCyclicInternal(pos, t);
2240 }
2241
2242
2243 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
2244 checkNonCyclic1(pos, t, List.<TypeVar>nil());
2245 }
2246
2247 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
2248 final TypeVar tv;
2249 if (t.hasTag(TYPEVAR) && (t.tsym.flags() & UNATTRIBUTED) != 0)
2250 return;
2251 if (seen.contains(t)) {
2252 tv = (TypeVar)t;
2253 tv.bound = types.createErrorType(t);
2254 log.error(pos, "cyclic.inheritance", t);
2255 } else if (t.hasTag(TYPEVAR)) {
2256 tv = (TypeVar)t;
2257 seen = seen.prepend(tv);
2258 for (Type b : types.getBounds(tv))
2259 checkNonCyclic1(pos, b, seen);
2260 }
2261 }
2262
2263 /** Check for cyclic references. Issue an error if the
2264 * symbol of the type referred to has a LOCKED flag set.
2265 *
2266 * @param pos Position to be used for error reporting.
2267 * @param t The type referred to.
2268 * @returns True if the check completed on all attributed classes
2269 */
2270 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
2271 boolean complete = true; // was the check complete?
2272 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
2273 Symbol c = t.tsym;
2274 if ((c.flags_field & ACYCLIC) != 0) return true;
2275
2276 if ((c.flags_field & LOCKED) != 0) {
2277 noteCyclic(pos, (ClassSymbol)c);
2278 } else if (!c.type.isErroneous()) {
2279 try {
2280 c.flags_field |= LOCKED;
2281 if (c.type.hasTag(CLASS)) {
2282 ClassType clazz = (ClassType)c.type;
2283 if (clazz.interfaces_field != null)
2284 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
2285 complete &= checkNonCyclicInternal(pos, l.head);
2286 if (clazz.supertype_field != null) {
2287 Type st = clazz.supertype_field;
2288 if (st != null && st.hasTag(CLASS))
2289 complete &= checkNonCyclicInternal(pos, st);
2290 }
2291 if (c.owner.kind == TYP)
2292 complete &= checkNonCyclicInternal(pos, c.owner.type);
2293 }
2294 } finally {
2295 c.flags_field &= ~LOCKED;
2296 }
2297 }
2298 if (complete)
2299 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
2300 if (complete) c.flags_field |= ACYCLIC;
2301 return complete;
2302 }
2303
2304 /** Note that we found an inheritance cycle. */
2305 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
2306 log.error(pos, "cyclic.inheritance", c);
2307 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
2308 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
2309 Type st = types.supertype(c.type);
2310 if (st.hasTag(CLASS))
2311 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2312 c.type = types.createErrorType(c, c.type);
2313 c.flags_field |= ACYCLIC;
2314 }
2315
2316 /** Check that all methods which implement some
2317 * method conform to the method they implement.
2318 * @param tree The class definition whose members are checked.
2319 */
2320 void checkImplementations(JCClassDecl tree) {
2321 checkImplementations(tree, tree.sym, tree.sym);
2322 }
2323 //where
2324 /** Check that all methods which implement some
2325 * method in `ic' conform to the method they implement.
2326 */
2327 void checkImplementations(JCTree tree, ClassSymbol origin, ClassSymbol ic) {
2328 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2329 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2330 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
2331 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
2332 if (e.sym.kind == MTH &&
2333 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2334 MethodSymbol absmeth = (MethodSymbol)e.sym;
2335 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2336 if (implmeth != null && implmeth != absmeth &&
2337 (implmeth.owner.flags() & INTERFACE) ==
2338 (origin.flags() & INTERFACE)) {
2339 // don't check if implmeth is in a class, yet
2340 // origin is an interface. This case arises only
2341 // if implmeth is declared in Object. The reason is
2342 // that interfaces really don't inherit from
2343 // Object it's just that the compiler represents
2344 // things that way.
2345 checkOverride(tree, implmeth, absmeth, origin);
2346 }
2347 }
2348 }
2349 }
2350 }
2351 }
2352
2353 /** Check that all abstract methods implemented by a class are
2354 * mutually compatible.
2355 * @param pos Position to be used for error reporting.
2356 * @param c The class whose interfaces are checked.
2357 */
2358 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2359 List<Type> supertypes = types.interfaces(c);
2360 Type supertype = types.supertype(c);
2361 if (supertype.hasTag(CLASS) &&
2362 (supertype.tsym.flags() & ABSTRACT) != 0)
2363 supertypes = supertypes.prepend(supertype);
2364 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2365 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
2366 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2367 return;
2368 for (List<Type> m = supertypes; m != l; m = m.tail)
2369 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2370 return;
2371 }
2372 checkCompatibleConcretes(pos, c);
2373 }
2374
2375 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
2376 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
2377 for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
2378 // VM allows methods and variables with differing types
2379 if (sym.kind == e.sym.kind &&
2380 types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
2381 sym != e.sym &&
2382 (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
2383 (sym.flags() & IPROXY) == 0 && (e.sym.flags() & IPROXY) == 0 &&
2384 (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
2385 syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
2386 return;
2387 }
2388 }
2389 }
2390 }
2391
2392 /** Check that all non-override equivalent methods accessible from 'site'
2393 * are mutually compatible (JLS 8.4.8/9.4.1).
2394 *
2395 * @param pos Position to be used for error reporting.
2396 * @param site The class whose methods are checked.
2397 * @param sym The method symbol to be checked.
2398 */
2399 void checkOverrideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2400 ClashFilter cf = new ClashFilter(site);
2401 //for each method m1 that is overridden (directly or indirectly)
2402 //by method 'sym' in 'site'...
2403
2404 List<MethodSymbol> potentiallyAmbiguousList = List.nil();
2405 boolean overridesAny = false;
2406 for (Symbol m1 : types.membersClosure(site, false).getElementsByName(sym.name, cf)) {
2407 if (!sym.overrides(m1, site.tsym, types, false)) {
2408 if (m1 == sym) {
2409 continue;
2410 }
2411
2412 if (!overridesAny) {
2413 potentiallyAmbiguousList = potentiallyAmbiguousList.prepend((MethodSymbol)m1);
2414 }
2415 continue;
2416 }
2417
2418 if (m1 != sym) {
2419 overridesAny = true;
2420 potentiallyAmbiguousList = List.nil();
2421 }
2422
2423 //...check each method m2 that is a member of 'site'
2424 for (Symbol m2 : types.membersClosure(site, false).getElementsByName(sym.name, cf)) {
2425 if (m2 == m1) continue;
2426 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2427 //a member of 'site') and (ii) m1 has the same erasure as m2, issue an error
2428 if (!types.isSubSignature(sym.type, types.memberType(site, m2), allowStrictMethodClashCheck) &&
2429 types.hasSameArgs(m2.erasure(types), m1.erasure(types))) {
2430 sym.flags_field |= CLASH;
2431 String key = m1 == sym ?
2432 "name.clash.same.erasure.no.override" :
2433 "name.clash.same.erasure.no.override.1";
2434 log.error(pos,
2435 key,
2436 sym, sym.location(),
2437 m2, m2.location(),
2438 m1, m1.location());
2439 return;
2440 }
2441 }
2442 }
2443
2444 if (!overridesAny) {
2445 for (MethodSymbol m: potentiallyAmbiguousList) {
2446 checkPotentiallyAmbiguousOverloads(pos, site, sym, m);
2447 }
2448 }
2449 }
2450
2451 /** Check that all static methods accessible from 'site' are
2452 * mutually compatible (JLS 8.4.8).
2453 *
2454 * @param pos Position to be used for error reporting.
2455 * @param site The class whose methods are checked.
2456 * @param sym The method symbol to be checked.
2457 */
2458 void checkHideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2459 ClashFilter cf = new ClashFilter(site);
2460 //for each method m1 that is a member of 'site'...
2461 for (Symbol s : types.membersClosure(site, true).getElementsByName(sym.name, cf)) {
2462 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2463 //a member of 'site') and (ii) 'sym' has the same erasure as m1, issue an error
2464 if (!types.isSubSignature(sym.type, types.memberType(site, s), allowStrictMethodClashCheck)) {
2465 if (types.hasSameArgs(s.erasure(types), sym.erasure(types))) {
2466 log.error(pos,
2467 "name.clash.same.erasure.no.hide",
2468 sym, sym.location(),
2469 s, s.location());
2470 return;
2471 } else {
2472 checkPotentiallyAmbiguousOverloads(pos, site, sym, (MethodSymbol)s);
2473 }
2474 }
2475 }
2476 }
2477
2478 //where
2479 private class ClashFilter implements Filter<Symbol> {
2480
2481 Type site;
2482
2483 ClashFilter(Type site) {
2484 this.site = site;
2485 }
2486
2487 boolean shouldSkip(Symbol s) {
2488 return (s.flags() & CLASH) != 0 &&
2489 s.owner == site.tsym;
2490 }
2491
2492 public boolean accepts(Symbol s) {
2493 return s.kind == MTH &&
2494 (s.flags() & SYNTHETIC) == 0 &&
2495 !shouldSkip(s) &&
2496 s.isInheritedIn(site.tsym, types) &&
2497 !s.isConstructor();
2498 }
2499 }
2500
2501 void checkDefaultMethodClashes(DiagnosticPosition pos, Type site) {
2502 DefaultMethodClashFilter dcf = new DefaultMethodClashFilter(site);
2503 for (Symbol m : types.membersClosure(site, false).getElements(dcf)) {
2504 Assert.check(m.kind == MTH);
2505 List<MethodSymbol> prov = types.interfaceCandidates(site, (MethodSymbol)m);
2506 if (prov.size() > 1) {
2507 ListBuffer<Symbol> abstracts = new ListBuffer<>();
2508 ListBuffer<Symbol> defaults = new ListBuffer<>();
2509 for (MethodSymbol provSym : prov) {
2510 if ((provSym.flags() & DEFAULT) != 0) {
2511 defaults = defaults.append(provSym);
2512 } else if ((provSym.flags() & ABSTRACT) != 0) {
2513 abstracts = abstracts.append(provSym);
2514 }
2515 if (defaults.nonEmpty() && defaults.size() + abstracts.size() >= 2) {
2516 //strong semantics - issue an error if two sibling interfaces
2517 //have two override-equivalent defaults - or if one is abstract
2518 //and the other is default
2519 String errKey;
2520 Symbol s1 = defaults.first();
2521 Symbol s2;
2522 if (defaults.size() > 1) {
2523 errKey = "types.incompatible.unrelated.defaults";
2524 s2 = defaults.toList().tail.head;
2525 } else {
2526 errKey = "types.incompatible.abstract.default";
2527 s2 = abstracts.first();
2528 }
2529 log.error(pos, errKey,
2530 Kinds.kindName(site.tsym), site,
2531 m.name, types.memberType(site, m).getParameterTypes(),
2532 s1.location(), s2.location());
2533 break;
2534 }
2535 }
2536 }
2537 }
2538 }
2539
2540 //where
2541 private class DefaultMethodClashFilter implements Filter<Symbol> {
2542
2543 Type site;
2544
2545 DefaultMethodClashFilter(Type site) {
2546 this.site = site;
2547 }
2548
2549 public boolean accepts(Symbol s) {
2550 return s.kind == MTH &&
2551 (s.flags() & DEFAULT) != 0 &&
2552 s.isInheritedIn(site.tsym, types) &&
2553 !s.isConstructor();
2554 }
2555 }
2556
2557 /**
2558 * Report warnings for potentially ambiguous method declarations. Two declarations
2559 * are potentially ambiguous if they feature two unrelated functional interface
2560 * in same argument position (in which case, a call site passing an implicit
2561 * lambda would be ambiguous).
2562 */
2563 void checkPotentiallyAmbiguousOverloads(DiagnosticPosition pos, Type site,
2564 MethodSymbol msym1, MethodSymbol msym2) {
2565 if (msym1 != msym2 &&
2566 allowDefaultMethods &&
2567 lint.isEnabled(LintCategory.OVERLOADS) &&
2568 (msym1.flags() & POTENTIALLY_AMBIGUOUS) == 0 &&
2569 (msym2.flags() & POTENTIALLY_AMBIGUOUS) == 0) {
2570 Type mt1 = types.memberType(site, msym1);
2571 Type mt2 = types.memberType(site, msym2);
2572 //if both generic methods, adjust type variables
2573 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL) &&
2574 types.hasSameBounds((ForAll)mt1, (ForAll)mt2)) {
2575 mt2 = types.subst(mt2, ((ForAll)mt2).tvars, ((ForAll)mt1).tvars);
2576 }
2577 //expand varargs methods if needed
2578 int maxLength = Math.max(mt1.getParameterTypes().length(), mt2.getParameterTypes().length());
2579 List<Type> args1 = rs.adjustArgs(mt1.getParameterTypes(), msym1, maxLength, true);
2580 List<Type> args2 = rs.adjustArgs(mt2.getParameterTypes(), msym2, maxLength, true);
2581 //if arities don't match, exit
2582 if (args1.length() != args2.length()) return;
2583 boolean potentiallyAmbiguous = false;
2584 while (args1.nonEmpty() && args2.nonEmpty()) {
2585 Type s = args1.head;
2586 Type t = args2.head;
2587 if (!types.isSubtype(t, s) && !types.isSubtype(s, t)) {
2588 if (types.isFunctionalInterface(s) && types.isFunctionalInterface(t) &&
2589 types.findDescriptorType(s).getParameterTypes().length() > 0 &&
2590 types.findDescriptorType(s).getParameterTypes().length() ==
2591 types.findDescriptorType(t).getParameterTypes().length()) {
2592 potentiallyAmbiguous = true;
2593 } else {
2594 break;
2595 }
2596 }
2597 args1 = args1.tail;
2598 args2 = args2.tail;
2599 }
2600 if (potentiallyAmbiguous) {
2601 //we found two incompatible functional interfaces with same arity
2602 //this means a call site passing an implicit lambda would be ambigiuous
2603 msym1.flags_field |= POTENTIALLY_AMBIGUOUS;
2604 msym2.flags_field |= POTENTIALLY_AMBIGUOUS;
2605 log.warning(LintCategory.OVERLOADS, pos, "potentially.ambiguous.overload",
2606 msym1, msym1.location(),
2607 msym2, msym2.location());
2608 return;
2609 }
2610 }
2611 }
2612
2613 void checkElemAccessFromSerializableLambda(final JCTree tree) {
2614 if (warnOnAccessToSensitiveMembers) {
2615 Symbol sym = TreeInfo.symbol(tree);
2616 if ((sym.kind & (VAR | MTH)) == 0) {
2617 return;
2618 }
2619
2620 if (sym.kind == VAR) {
2621 if ((sym.flags() & PARAMETER) != 0 ||
2622 sym.isLocal() ||
2623 sym.name == names._this ||
2624 sym.name == names._super) {
2625 return;
2626 }
2627 }
2628
2629 if (!types.isSubtype(sym.owner.type, syms.serializableType) &&
2630 isEffectivelyNonPublic(sym)) {
2631 log.warning(tree.pos(),
2632 "access.to.sensitive.member.from.serializable.element", sym);
2633 }
2634 }
2635 }
2636
2637 private boolean isEffectivelyNonPublic(Symbol sym) {
2638 if (sym.packge() == syms.rootPackage) {
2639 return false;
2640 }
2641
2642 while (sym.kind != Kinds.PCK) {
2643 if ((sym.flags() & PUBLIC) == 0) {
2644 return true;
2645 }
2646 sym = sym.owner;
2647 }
2648 return false;
2649 }
2650
2651 /** Report a conflict between a user symbol and a synthetic symbol.
2652 */
2653 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
2654 if (!sym.type.isErroneous()) {
2655 if (warnOnSyntheticConflicts) {
2656 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
2657 }
2658 else {
2659 log.error(pos, "synthetic.name.conflict", sym, sym.location());
2660 }
2661 }
2662 }
2663
2664 /** Check that class c does not implement directly or indirectly
2665 * the same parameterized interface with two different argument lists.
2666 * @param pos Position to be used for error reporting.
2667 * @param type The type whose interfaces are checked.
2668 */
2669 void checkClassBounds(DiagnosticPosition pos, Type type) {
2670 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
2671 }
2672 //where
2673 /** Enter all interfaces of type `type' into the hash table `seensofar'
2674 * with their class symbol as key and their type as value. Make
2675 * sure no class is entered with two different types.
2676 */
2677 void checkClassBounds(DiagnosticPosition pos,
2678 Map<TypeSymbol,Type> seensofar,
2679 Type type) {
2680 if (type.isErroneous()) return;
2681 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
2682 Type it = l.head;
2683 Type oldit = seensofar.put(it.tsym, it);
2684 if (oldit != null) {
2685 List<Type> oldparams = oldit.allparams();
2686 List<Type> newparams = it.allparams();
2687 if (!types.containsTypeEquivalent(oldparams, newparams))
2688 log.error(pos, "cant.inherit.diff.arg",
2689 it.tsym, Type.toString(oldparams),
2690 Type.toString(newparams));
2691 }
2692 checkClassBounds(pos, seensofar, it);
2693 }
2694 Type st = types.supertype(type);
2695 if (st != null) checkClassBounds(pos, seensofar, st);
2696 }
2697
2698 /** Enter interface into into set.
2699 * If it existed already, issue a "repeated interface" error.
2700 */
2701 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
2702 if (its.contains(it))
2703 log.error(pos, "repeated.interface");
2704 else {
2705 its.add(it);
2706 }
2707 }
2708
2709 /* *************************************************************************
2710 * Check annotations
2711 **************************************************************************/
2712
2713 /**
2714 * Recursively validate annotations values
2715 */
2716 void validateAnnotationTree(JCTree tree) {
2717 class AnnotationValidator extends TreeScanner {
2718 @Override
2719 public void visitAnnotation(JCAnnotation tree) {
2720 if (!tree.type.isErroneous()) {
2721 super.visitAnnotation(tree);
2722 validateAnnotation(tree);
2723 }
2724 }
2725 }
2726 tree.accept(new AnnotationValidator());
2727 }
2728
2729 /**
2730 * {@literal
2731 * Annotation types are restricted to primitives, String, an
2732 * enum, an annotation, Class, Class<?>, Class<? extends
2733 * Anything>, arrays of the preceding.
2734 * }
2735 */
2736 void validateAnnotationType(JCTree restype) {
2737 // restype may be null if an error occurred, so don't bother validating it
2738 if (restype != null) {
2739 validateAnnotationType(restype.pos(), restype.type);
2740 }
2741 }
2742
2743 void validateAnnotationType(DiagnosticPosition pos, Type type) {
2744 if (type.isPrimitive()) return;
2745 if (types.isSameType(type, syms.stringType)) return;
2746 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
2747 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
2748 if (types.cvarLowerBound(type).tsym == syms.classType.tsym) return;
2749 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
2750 validateAnnotationType(pos, types.elemtype(type));
2751 return;
2752 }
2753 log.error(pos, "invalid.annotation.member.type");
2754 }
2755
2756 /**
2757 * "It is also a compile-time error if any method declared in an
2758 * annotation type has a signature that is override-equivalent to
2759 * that of any public or protected method declared in class Object
2760 * or in the interface annotation.Annotation."
2761 *
2762 * @jls 9.6 Annotation Types
2763 */
2764 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
2765 for (Type sup = syms.annotationType; sup.hasTag(CLASS); sup = types.supertype(sup)) {
2766 Scope s = sup.tsym.members();
2767 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
2768 if (e.sym.kind == MTH &&
2769 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
2770 types.overrideEquivalent(m.type, e.sym.type))
2771 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
2772 }
2773 }
2774 }
2775
2776 /** Check the annotations of a symbol.
2777 */
2778 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
2779 for (JCAnnotation a : annotations)
2780 validateAnnotation(a, s);
2781 }
2782
2783 /** Check the type annotations.
2784 */
2785 public void validateTypeAnnotations(List<JCAnnotation> annotations, boolean isTypeParameter) {
2786 for (JCAnnotation a : annotations)
2787 validateTypeAnnotation(a, isTypeParameter);
2788 }
2789
2790 /** Check an annotation of a symbol.
2791 */
2792 private void validateAnnotation(JCAnnotation a, Symbol s) {
2793 validateAnnotationTree(a);
2794
2795 if (!annotationApplicable(a, s))
2796 log.error(a.pos(), "annotation.type.not.applicable");
2797
2798 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
2799 if (s.kind != TYP) {
2800 log.error(a.pos(), "bad.functional.intf.anno");
2801 } else if (!s.isInterface() || (s.flags() & ANNOTATION) != 0) {
2802 log.error(a.pos(), "bad.functional.intf.anno.1", diags.fragment("not.a.functional.intf", s));
2803 }
2804 }
2805 }
2806
2807 public void validateTypeAnnotation(JCAnnotation a, boolean isTypeParameter) {
2808 Assert.checkNonNull(a.type, "annotation tree hasn't been attributed yet: " + a);
2809 validateAnnotationTree(a);
2810
2811 if (a.hasTag(TYPE_ANNOTATION) &&
2812 !a.annotationType.type.isErroneous() &&
2813 !isTypeAnnotation(a, isTypeParameter)) {
2814 log.error(a.pos(), "annotation.type.not.applicable");
2815 }
2816 }
2817
2818 /**
2819 * Validate the proposed container 'repeatable' on the
2820 * annotation type symbol 's'. Report errors at position
2821 * 'pos'.
2822 *
2823 * @param s The (annotation)type declaration annotated with a @Repeatable
2824 * @param repeatable the @Repeatable on 's'
2825 * @param pos where to report errors
2826 */
2827 public void validateRepeatable(TypeSymbol s, Attribute.Compound repeatable, DiagnosticPosition pos) {
2828 Assert.check(types.isSameType(repeatable.type, syms.repeatableType));
2829
2830 Type t = null;
2831 List<Pair<MethodSymbol,Attribute>> l = repeatable.values;
2832 if (!l.isEmpty()) {
2833 Assert.check(l.head.fst.name == names.value);
2834 t = ((Attribute.Class)l.head.snd).getValue();
2835 }
2836
2837 if (t == null) {
2838 // errors should already have been reported during Annotate
2839 return;
2840 }
2841
2842 validateValue(t.tsym, s, pos);
2843 validateRetention(t.tsym, s, pos);
2844 validateDocumented(t.tsym, s, pos);
2845 validateInherited(t.tsym, s, pos);
2846 validateTarget(t.tsym, s, pos);
2847 validateDefault(t.tsym, pos);
2848 }
2849
2850 private void validateValue(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
2851 Scope.Entry e = container.members().lookup(names.value);
2852 if (e.scope != null && e.sym.kind == MTH) {
2853 MethodSymbol m = (MethodSymbol) e.sym;
2854 Type ret = m.getReturnType();
2855 if (!(ret.hasTag(ARRAY) && types.isSameType(((ArrayType)ret).elemtype, contained.type))) {
2856 log.error(pos, "invalid.repeatable.annotation.value.return",
2857 container, ret, types.makeArrayType(contained.type));
2858 }
2859 } else {
2860 log.error(pos, "invalid.repeatable.annotation.no.value", container);
2861 }
2862 }
2863
2864 private void validateRetention(Symbol container, Symbol contained, DiagnosticPosition pos) {
2865 Attribute.RetentionPolicy containerRetention = types.getRetention(container);
2866 Attribute.RetentionPolicy containedRetention = types.getRetention(contained);
2867
2868 boolean error = false;
2869 switch (containedRetention) {
2870 case RUNTIME:
2871 if (containerRetention != Attribute.RetentionPolicy.RUNTIME) {
2872 error = true;
2873 }
2874 break;
2875 case CLASS:
2876 if (containerRetention == Attribute.RetentionPolicy.SOURCE) {
2877 error = true;
2878 }
2879 }
2880 if (error ) {
2881 log.error(pos, "invalid.repeatable.annotation.retention",
2882 container, containerRetention,
2883 contained, containedRetention);
2884 }
2885 }
2886
2887 private void validateDocumented(Symbol container, Symbol contained, DiagnosticPosition pos) {
2888 if (contained.attribute(syms.documentedType.tsym) != null) {
2889 if (container.attribute(syms.documentedType.tsym) == null) {
2890 log.error(pos, "invalid.repeatable.annotation.not.documented", container, contained);
2891 }
2892 }
2893 }
2894
2895 private void validateInherited(Symbol container, Symbol contained, DiagnosticPosition pos) {
2896 if (contained.attribute(syms.inheritedType.tsym) != null) {
2897 if (container.attribute(syms.inheritedType.tsym) == null) {
2898 log.error(pos, "invalid.repeatable.annotation.not.inherited", container, contained);
2899 }
2900 }
2901 }
2902
2903 private void validateTarget(Symbol container, Symbol contained, DiagnosticPosition pos) {
2904 // The set of targets the container is applicable to must be a subset
2905 // (with respect to annotation target semantics) of the set of targets
2906 // the contained is applicable to. The target sets may be implicit or
2907 // explicit.
2908
2909 Set<Name> containerTargets;
2910 Attribute.Array containerTarget = getAttributeTargetAttribute(container);
2911 if (containerTarget == null) {
2912 containerTargets = getDefaultTargetSet();
2913 } else {
2914 containerTargets = new HashSet<>();
2915 for (Attribute app : containerTarget.values) {
2916 if (!(app instanceof Attribute.Enum)) {
2917 continue; // recovery
2918 }
2919 Attribute.Enum e = (Attribute.Enum)app;
2920 containerTargets.add(e.value.name);
2921 }
2922 }
2923
2924 Set<Name> containedTargets;
2925 Attribute.Array containedTarget = getAttributeTargetAttribute(contained);
2926 if (containedTarget == null) {
2927 containedTargets = getDefaultTargetSet();
2928 } else {
2929 containedTargets = new HashSet<>();
2930 for (Attribute app : containedTarget.values) {
2931 if (!(app instanceof Attribute.Enum)) {
2932 continue; // recovery
2933 }
2934 Attribute.Enum e = (Attribute.Enum)app;
2935 containedTargets.add(e.value.name);
2936 }
2937 }
2938
2939 if (!isTargetSubsetOf(containerTargets, containedTargets)) {
2940 log.error(pos, "invalid.repeatable.annotation.incompatible.target", container, contained);
2941 }
2942 }
2943
2944 /* get a set of names for the default target */
2945 private Set<Name> getDefaultTargetSet() {
2946 if (defaultTargets == null) {
2947 Set<Name> targets = new HashSet<>();
2948 targets.add(names.ANNOTATION_TYPE);
2949 targets.add(names.CONSTRUCTOR);
2950 targets.add(names.FIELD);
2951 targets.add(names.LOCAL_VARIABLE);
2952 targets.add(names.METHOD);
2953 targets.add(names.PACKAGE);
2954 targets.add(names.PARAMETER);
2955 targets.add(names.TYPE);
2956
2957 defaultTargets = java.util.Collections.unmodifiableSet(targets);
2958 }
2959
2960 return defaultTargets;
2961 }
2962 private Set<Name> defaultTargets;
2963
2964
2965 /** Checks that s is a subset of t, with respect to ElementType
2966 * semantics, specifically {ANNOTATION_TYPE} is a subset of {TYPE},
2967 * and {TYPE_USE} covers the set {ANNOTATION_TYPE, TYPE, TYPE_USE,
2968 * TYPE_PARAMETER}.
2969 */
2970 private boolean isTargetSubsetOf(Set<Name> s, Set<Name> t) {
2971 // Check that all elements in s are present in t
2972 for (Name n2 : s) {
2973 boolean currentElementOk = false;
2974 for (Name n1 : t) {
2975 if (n1 == n2) {
2976 currentElementOk = true;
2977 break;
2978 } else if (n1 == names.TYPE && n2 == names.ANNOTATION_TYPE) {
2979 currentElementOk = true;
2980 break;
2981 } else if (n1 == names.TYPE_USE &&
2982 (n2 == names.TYPE ||
2983 n2 == names.ANNOTATION_TYPE ||
2984 n2 == names.TYPE_PARAMETER)) {
2985 currentElementOk = true;
2986 break;
2987 }
2988 }
2989 if (!currentElementOk)
2990 return false;
2991 }
2992 return true;
2993 }
2994
2995 private void validateDefault(Symbol container, DiagnosticPosition pos) {
2996 // validate that all other elements of containing type has defaults
2997 Scope scope = container.members();
2998 for(Symbol elm : scope.getElements()) {
2999 if (elm.name != names.value &&
3000 elm.kind == Kinds.MTH &&
3001 ((MethodSymbol)elm).defaultValue == null) {
3002 log.error(pos,
3003 "invalid.repeatable.annotation.elem.nondefault",
3004 container,
3005 elm);
3006 }
3007 }
3008 }
3009
3010 /** Is s a method symbol that overrides a method in a superclass? */
3011 boolean isOverrider(Symbol s) {
3012 if (s.kind != MTH || s.isStatic())
3013 return false;
3014 MethodSymbol m = (MethodSymbol)s;
3015 TypeSymbol owner = (TypeSymbol)m.owner;
3016 for (Type sup : types.closure(owner.type)) {
3017 if (sup == owner.type)
3018 continue; // skip "this"
3019 Scope scope = sup.tsym.members();
3020 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
3021 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
3022 return true;
3023 }
3024 }
3025 return false;
3026 }
3027
3028 /** Is the annotation applicable to types? */
3029 protected boolean isTypeAnnotation(JCAnnotation a, boolean isTypeParameter) {
3030 Attribute.Compound atTarget =
3031 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
3032 if (atTarget == null) {
3033 // An annotation without @Target is not a type annotation.
3034 return false;
3035 }
3036
3037 Attribute atValue = atTarget.member(names.value);
3038 if (!(atValue instanceof Attribute.Array)) {
3039 return false; // error recovery
3040 }
3041
3042 Attribute.Array arr = (Attribute.Array) atValue;
3043 for (Attribute app : arr.values) {
3044 if (!(app instanceof Attribute.Enum)) {
3045 return false; // recovery
3046 }
3047 Attribute.Enum e = (Attribute.Enum) app;
3048
3049 if (e.value.name == names.TYPE_USE)
3050 return true;
3051 else if (isTypeParameter && e.value.name == names.TYPE_PARAMETER)
3052 return true;
3053 }
3054 return false;
3055 }
3056
3057 /** Is the annotation applicable to the symbol? */
3058 boolean annotationApplicable(JCAnnotation a, Symbol s) {
3059 Attribute.Array arr = getAttributeTargetAttribute(a.annotationType.type.tsym);
3060 Name[] targets;
3061
3062 if (arr == null) {
3063 targets = defaultTargetMetaInfo(a, s);
3064 } else {
3065 // TODO: can we optimize this?
3066 targets = new Name[arr.values.length];
3067 for (int i=0; i<arr.values.length; ++i) {
3068 Attribute app = arr.values[i];
3069 if (!(app instanceof Attribute.Enum)) {
3070 return true; // recovery
3071 }
3072 Attribute.Enum e = (Attribute.Enum) app;
3073 targets[i] = e.value.name;
3074 }
3075 }
3076 for (Name target : targets) {
3077 if (target == names.TYPE)
3078 { if (s.kind == TYP) return true; }
3079 else if (target == names.FIELD)
3080 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
3081 else if (target == names.METHOD)
3082 { if (s.kind == MTH && !s.isConstructor()) return true; }
3083 else if (target == names.PARAMETER)
3084 { if (s.kind == VAR &&
3085 s.owner.kind == MTH &&
3086 (s.flags() & PARAMETER) != 0)
3087 return true;
3088 }
3089 else if (target == names.CONSTRUCTOR)
3090 { if (s.kind == MTH && s.isConstructor()) return true; }
3091 else if (target == names.LOCAL_VARIABLE)
3092 { if (s.kind == VAR && s.owner.kind == MTH &&
3093 (s.flags() & PARAMETER) == 0)
3094 return true;
3095 }
3096 else if (target == names.ANNOTATION_TYPE)
3097 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
3098 return true;
3099 }
3100 else if (target == names.PACKAGE)
3101 { if (s.kind == PCK) return true; }
3102 else if (target == names.TYPE_USE)
3103 { if (s.kind == TYP ||
3104 s.kind == VAR ||
3105 (s.kind == MTH && !s.isConstructor() &&
3106 !s.type.getReturnType().hasTag(VOID)) ||
3107 (s.kind == MTH && s.isConstructor()))
3108 return true;
3109 }
3110 else if (target == names.TYPE_PARAMETER)
3111 { if (s.kind == TYP && s.type.hasTag(TYPEVAR))
3112 return true;
3113 }
3114 else
3115 return true; // recovery
3116 }
3117 return false;
3118 }
3119
3120
3121 Attribute.Array getAttributeTargetAttribute(Symbol s) {
3122 Attribute.Compound atTarget =
3123 s.attribute(syms.annotationTargetType.tsym);
3124 if (atTarget == null) return null; // ok, is applicable
3125 Attribute atValue = atTarget.member(names.value);
3126 if (!(atValue instanceof Attribute.Array)) return null; // error recovery
3127 return (Attribute.Array) atValue;
3128 }
3129
3130 private final Name[] dfltTargetMeta;
3131 private Name[] defaultTargetMetaInfo(JCAnnotation a, Symbol s) {
3132 return dfltTargetMeta;
3133 }
3134
3135 /** Check an annotation value.
3136 *
3137 * @param a The annotation tree to check
3138 * @return true if this annotation tree is valid, otherwise false
3139 */
3140 public boolean validateAnnotationDeferErrors(JCAnnotation a) {
3141 boolean res = false;
3142 final Log.DiagnosticHandler diagHandler = new Log.DiscardDiagnosticHandler(log);
3143 try {
3144 res = validateAnnotation(a);
3145 } finally {
3146 log.popDiagnosticHandler(diagHandler);
3147 }
3148 return res;
3149 }
3150
3151 private boolean validateAnnotation(JCAnnotation a) {
3152 boolean isValid = true;
3153 // collect an inventory of the annotation elements
3154 Set<MethodSymbol> members = new LinkedHashSet<>();
3155 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
3156 e != null;
3157 e = e.sibling)
3158 if (e.sym.kind == MTH && e.sym.name != names.clinit &&
3159 (e.sym.flags() & SYNTHETIC) == 0)
3160 members.add((MethodSymbol) e.sym);
3161
3162 // remove the ones that are assigned values
3163 for (JCTree arg : a.args) {
3164 if (!arg.hasTag(ASSIGN)) continue; // recovery
3165 JCAssign assign = (JCAssign) arg;
3166 Symbol m = TreeInfo.symbol(assign.lhs);
3167 if (m == null || m.type.isErroneous()) continue;
3168 if (!members.remove(m)) {
3169 isValid = false;
3170 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
3171 m.name, a.type);
3172 }
3173 }
3174
3175 // all the remaining ones better have default values
3176 List<Name> missingDefaults = List.nil();
3177 for (MethodSymbol m : members) {
3178 if (m.defaultValue == null && !m.type.isErroneous()) {
3179 missingDefaults = missingDefaults.append(m.name);
3180 }
3181 }
3182 missingDefaults = missingDefaults.reverse();
3183 if (missingDefaults.nonEmpty()) {
3184 isValid = false;
3185 String key = (missingDefaults.size() > 1)
3186 ? "annotation.missing.default.value.1"
3187 : "annotation.missing.default.value";
3188 log.error(a.pos(), key, a.type, missingDefaults);
3189 }
3190
3191 // special case: java.lang.annotation.Target must not have
3192 // repeated values in its value member
3193 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
3194 a.args.tail == null)
3195 return isValid;
3196
3197 if (!a.args.head.hasTag(ASSIGN)) return false; // error recovery
3198 JCAssign assign = (JCAssign) a.args.head;
3199 Symbol m = TreeInfo.symbol(assign.lhs);
3200 if (m.name != names.value) return false;
3201 JCTree rhs = assign.rhs;
3202 if (!rhs.hasTag(NEWARRAY)) return false;
3203 JCNewArray na = (JCNewArray) rhs;
3204 Set<Symbol> targets = new HashSet<>();
3205 for (JCTree elem : na.elems) {
3206 if (!targets.add(TreeInfo.symbol(elem))) {
3207 isValid = false;
3208 log.error(elem.pos(), "repeated.annotation.target");
3209 }
3210 }
3211 return isValid;
3212 }
3213
3214 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
3215 if (allowAnnotations &&
3216 lint.isEnabled(LintCategory.DEP_ANN) &&
3217 (s.flags() & DEPRECATED) != 0 &&
3218 !syms.deprecatedType.isErroneous() &&
3219 s.attribute(syms.deprecatedType.tsym) == null) {
3220 log.warning(LintCategory.DEP_ANN,
3221 pos, "missing.deprecated.annotation");
3222 }
3223 }
3224
3225 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
3226 if ((s.flags() & DEPRECATED) != 0 &&
3227 (other.flags() & DEPRECATED) == 0 &&
3228 s.outermostClass() != other.outermostClass()) {
3229 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
3230 @Override
3231 public void report() {
3232 warnDeprecated(pos, s);
3233 }
3234 });
3235 }
3236 }
3237
3238 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
3239 if ((s.flags() & PROPRIETARY) != 0) {
3240 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
3241 public void report() {
3242 if (enableSunApiLintControl)
3243 warnSunApi(pos, "sun.proprietary", s);
3244 else
3245 log.mandatoryWarning(pos, "sun.proprietary", s);
3246 }
3247 });
3248 }
3249 }
3250
3251 void checkProfile(final DiagnosticPosition pos, final Symbol s) {
3252 if (profile != Profile.DEFAULT && (s.flags() & NOT_IN_PROFILE) != 0) {
3253 log.error(pos, "not.in.profile", s, profile);
3254 }
3255 }
3256
3257 /* *************************************************************************
3258 * Check for recursive annotation elements.
3259 **************************************************************************/
3260
3261 /** Check for cycles in the graph of annotation elements.
3262 */
3263 void checkNonCyclicElements(JCClassDecl tree) {
3264 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
3265 Assert.check((tree.sym.flags_field & LOCKED) == 0);
3266 try {
3267 tree.sym.flags_field |= LOCKED;
3268 for (JCTree def : tree.defs) {
3269 if (!def.hasTag(METHODDEF)) continue;
3270 JCMethodDecl meth = (JCMethodDecl)def;
3271 checkAnnotationResType(meth.pos(), meth.restype.type);
3272 }
3273 } finally {
3274 tree.sym.flags_field &= ~LOCKED;
3275 tree.sym.flags_field |= ACYCLIC_ANN;
3276 }
3277 }
3278
3279 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
3280 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
3281 return;
3282 if ((tsym.flags_field & LOCKED) != 0) {
3283 log.error(pos, "cyclic.annotation.element");
3284 return;
3285 }
3286 try {
3287 tsym.flags_field |= LOCKED;
3288 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
3289 Symbol s = e.sym;
3290 if (s.kind != Kinds.MTH)
3291 continue;
3292 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
3293 }
3294 } finally {
3295 tsym.flags_field &= ~LOCKED;
3296 tsym.flags_field |= ACYCLIC_ANN;
3297 }
3298 }
3299
3300 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
3301 switch (type.getTag()) {
3302 case CLASS:
3303 if ((type.tsym.flags() & ANNOTATION) != 0)
3304 checkNonCyclicElementsInternal(pos, type.tsym);
3305 break;
3306 case ARRAY:
3307 checkAnnotationResType(pos, types.elemtype(type));
3308 break;
3309 default:
3310 break; // int etc
3311 }
3312 }
3313
3314 /* *************************************************************************
3315 * Check for cycles in the constructor call graph.
3316 **************************************************************************/
3317
3318 /** Check for cycles in the graph of constructors calling other
3319 * constructors.
3320 */
3321 void checkCyclicConstructors(JCClassDecl tree) {
3322 Map<Symbol,Symbol> callMap = new HashMap<>();
3323
3324 // enter each constructor this-call into the map
3325 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3326 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
3327 if (app == null) continue;
3328 JCMethodDecl meth = (JCMethodDecl) l.head;
3329 if (TreeInfo.name(app.meth) == names._this) {
3330 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
3331 } else {
3332 meth.sym.flags_field |= ACYCLIC;
3333 }
3334 }
3335
3336 // Check for cycles in the map
3337 Symbol[] ctors = new Symbol[0];
3338 ctors = callMap.keySet().toArray(ctors);
3339 for (Symbol caller : ctors) {
3340 checkCyclicConstructor(tree, caller, callMap);
3341 }
3342 }
3343
3344 /** Look in the map to see if the given constructor is part of a
3345 * call cycle.
3346 */
3347 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
3348 Map<Symbol,Symbol> callMap) {
3349 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
3350 if ((ctor.flags_field & LOCKED) != 0) {
3351 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
3352 "recursive.ctor.invocation");
3353 } else {
3354 ctor.flags_field |= LOCKED;
3355 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
3356 ctor.flags_field &= ~LOCKED;
3357 }
3358 ctor.flags_field |= ACYCLIC;
3359 }
3360 }
3361
3362 /* *************************************************************************
3363 * Miscellaneous
3364 **************************************************************************/
3365
3366 /**
3367 * Return the opcode of the operator but emit an error if it is an
3368 * error.
3369 * @param pos position for error reporting.
3370 * @param operator an operator
3371 * @param tag a tree tag
3372 * @param left type of left hand side
3373 * @param right type of right hand side
3374 */
3375 int checkOperator(DiagnosticPosition pos,
3376 OperatorSymbol operator,
3377 JCTree.Tag tag,
3378 Type left,
3379 Type right) {
3380 if (operator.opcode == ByteCodes.error) {
3381 log.error(pos,
3382 "operator.cant.be.applied.1",
3383 treeinfo.operatorName(tag),
3384 left, right);
3385 }
3386 return operator.opcode;
3387 }
3388
3389
3390 /**
3391 * Check for division by integer constant zero
3392 * @param pos Position for error reporting.
3393 * @param operator The operator for the expression
3394 * @param operand The right hand operand for the expression
3395 */
3396 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
3397 if (operand.constValue() != null
3398 && lint.isEnabled(LintCategory.DIVZERO)
3399 && operand.getTag().isSubRangeOf(LONG)
3400 && ((Number) (operand.constValue())).longValue() == 0) {
3401 int opc = ((OperatorSymbol)operator).opcode;
3402 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
3403 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
3404 log.warning(LintCategory.DIVZERO, pos, "div.zero");
3405 }
3406 }
3407 }
3408
3409 /**
3410 * Check for empty statements after if
3411 */
3412 void checkEmptyIf(JCIf tree) {
3413 if (tree.thenpart.hasTag(SKIP) && tree.elsepart == null &&
3414 lint.isEnabled(LintCategory.EMPTY))
3415 log.warning(LintCategory.EMPTY, tree.thenpart.pos(), "empty.if");
3416 }
3417
3418 /** Check that symbol is unique in given scope.
3419 * @param pos Position for error reporting.
3420 * @param sym The symbol.
3421 * @param s The scope.
3422 */
3423 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
3424 if (sym.type.isErroneous())
3425 return true;
3426 if (sym.owner.name == names.any) return false;
3427 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
3428 if (sym != e.sym &&
3429 (e.sym.flags() & CLASH) == 0 &&
3430 sym.kind == e.sym.kind &&
3431 sym.name != names.error &&
3432 (sym.kind != MTH ||
3433 types.hasSameArgs(sym.type, e.sym.type) ||
3434 types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
3435 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS)) {
3436 varargsDuplicateError(pos, sym, e.sym);
3437 return true;
3438 } else if (sym.kind == MTH && !types.hasSameArgs(sym.type, e.sym.type, false)) {
3439 duplicateErasureError(pos, sym, e.sym);
3440 sym.flags_field |= CLASH;
3441 return true;
3442 } else {
3443 duplicateError(pos, e.sym);
3444 return false;
3445 }
3446 }
3447 }
3448 return true;
3449 }
3450
3451 /** Report duplicate declaration error.
3452 */
3453 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
3454 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
3455 log.error(pos, "name.clash.same.erasure", sym1, sym2);
3456 }
3457 }
3458
3459 /** Check that single-type import is not already imported or top-level defined,
3460 * but make an exception for two single-type imports which denote the same type.
3461 * @param pos Position for error reporting.
3462 * @param sym The symbol.
3463 * @param s The scope
3464 */
3465 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
3466 return checkUniqueImport(pos, sym, s, false);
3467 }
3468
3469 /** Check that static single-type import is not already imported or top-level defined,
3470 * but make an exception for two single-type imports which denote the same type.
3471 * @param pos Position for error reporting.
3472 * @param sym The symbol.
3473 * @param s The scope
3474 */
3475 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
3476 return checkUniqueImport(pos, sym, s, true);
3477 }
3478
3479 /** Check that single-type import is not already imported or top-level defined,
3480 * but make an exception for two single-type imports which denote the same type.
3481 * @param pos Position for error reporting.
3482 * @param sym The symbol.
3483 * @param s The scope.
3484 * @param staticImport Whether or not this was a static import
3485 */
3486 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
3487 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
3488 // is encountered class entered via a class declaration?
3489 boolean isClassDecl = e.scope == s;
3490 if ((isClassDecl || sym != e.sym) &&
3491 sym.kind == e.sym.kind &&
3492 sym.name != names.error &&
3493 (!staticImport || !e.isStaticallyImported())) {
3494 if (!e.sym.type.isErroneous()) {
3495 if (!isClassDecl) {
3496 if (staticImport)
3497 log.error(pos, "already.defined.static.single.import", e.sym);
3498 else
3499 log.error(pos, "already.defined.single.import", e.sym);
3500 }
3501 else if (sym != e.sym)
3502 log.error(pos, "already.defined.this.unit", e.sym);
3503 }
3504 return false;
3505 }
3506 }
3507 return true;
3508 }
3509
3510 /** Check that a qualified name is in canonical form (for import decls).
3511 */
3512 public void checkCanonical(JCTree tree) {
3513 if (!isCanonical(tree))
3514 log.error(tree.pos(), "import.requires.canonical",
3515 TreeInfo.symbol(tree));
3516 }
3517 // where
3518 private boolean isCanonical(JCTree tree) {
3519 while (tree.hasTag(SELECT)) {
3520 JCFieldAccess s = (JCFieldAccess) tree;
3521 if (s.sym.owner != TreeInfo.symbol(s.selected))
3522 return false;
3523 tree = s.selected;
3524 }
3525 return true;
3526 }
3527
3528 /** Check that an auxiliary class is not accessed from any other file than its own.
3529 */
3530 void checkForBadAuxiliaryClassAccess(DiagnosticPosition pos, Env<AttrContext> env, ClassSymbol c) {
3531 if (lint.isEnabled(Lint.LintCategory.AUXILIARYCLASS) &&
3532 (c.flags() & AUXILIARY) != 0 &&
3533 rs.isAccessible(env, c) &&
3534 !fileManager.isSameFile(c.sourcefile, env.toplevel.sourcefile))
3535 {
3536 log.warning(pos, "auxiliary.class.accessed.from.outside.of.its.source.file",
3537 c, c.sourcefile);
3538 }
3539 }
3540
3541 private class ConversionWarner extends Warner {
3542 final String uncheckedKey;
3543 final Type found;
3544 final Type expected;
3545 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
3546 super(pos);
3547 this.uncheckedKey = uncheckedKey;
3548 this.found = found;
3549 this.expected = expected;
3550 }
3551
3552 @Override
3553 public void warn(LintCategory lint) {
3554 boolean warned = this.warned;
3555 super.warn(lint);
3556 if (warned) return; // suppress redundant diagnostics
3557 switch (lint) {
3558 case UNCHECKED:
3559 Check.this.warnUnchecked(pos(), "prob.found.req", diags.fragment(uncheckedKey), found, expected);
3560 break;
3561 case VARARGS:
3562 if (method != null &&
3563 method.attribute(syms.trustMeType.tsym) != null &&
3564 isTrustMeAllowedOnMethod(method) &&
3565 !types.isReifiable(method.type.getParameterTypes().last())) {
3566 Check.this.warnUnsafeVararg(pos(), "varargs.unsafe.use.varargs.param", method.params.last());
3567 }
3568 break;
3569 default:
3570 throw new AssertionError("Unexpected lint: " + lint);
3571 }
3572 }
3573 }
3574
3575 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
3576 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
3577 }
3578
3579 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
3580 return new ConversionWarner(pos, "unchecked.assign", found, expected);
3581 }
3582
3583 public void checkFunctionalInterface(JCClassDecl tree, ClassSymbol cs) {
3584 Compound functionalType = cs.attribute(syms.functionalInterfaceType.tsym);
3585
3586 if (functionalType != null) {
3587 try {
3588 types.findDescriptorSymbol((TypeSymbol)cs);
3589 } catch (Types.FunctionDescriptorLookupError ex) {
3590 DiagnosticPosition pos = tree.pos();
3591 for (JCAnnotation a : tree.getModifiers().annotations) {
3592 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
3593 pos = a.pos();
3594 break;
3595 }
3596 }
3597 log.error(pos, "bad.functional.intf.anno.1", ex.getDiagnostic());
3598 }
3599 }
3600 }
3601 }