1 /*
2 * Copyright (c) 1999, 2009, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.comp;
27
28 import java.util.*;
29 import java.util.Set;
30
31 import com.sun.tools.javac.code.*;
32 import com.sun.tools.javac.jvm.*;
33 import com.sun.tools.javac.tree.*;
34 import com.sun.tools.javac.util.*;
35 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
36 import com.sun.tools.javac.util.List;
37
38 import com.sun.tools.javac.tree.JCTree.*;
39 import com.sun.tools.javac.code.Lint;
40 import com.sun.tools.javac.code.Lint.LintCategory;
41 import com.sun.tools.javac.code.Type.*;
42 import com.sun.tools.javac.code.Symbol.*;
43
44 import static com.sun.tools.javac.code.Flags.*;
45 import static com.sun.tools.javac.code.Kinds.*;
46 import static com.sun.tools.javac.code.TypeTags.*;
47
48 /** Type checking helper class for the attribution phase.
49 *
50 * <p><b>This is NOT part of any supported API.
51 * If you write code that depends on this, you do so at your own risk.
52 * This code and its internal interfaces are subject to change or
53 * deletion without notice.</b>
54 */
55 public class Check {
56 protected static final Context.Key<Check> checkKey =
57 new Context.Key<Check>();
58
59 private final Names names;
60 private final Log log;
61 private final Symtab syms;
62 private final Infer infer;
63 private final Types types;
64 private final JCDiagnostic.Factory diags;
65 private final boolean skipAnnotations;
66 private boolean warnOnSyntheticConflicts;
67 private boolean suppressAbortOnBadClassFile;
68 private final TreeInfo treeinfo;
69
70 // The set of lint options currently in effect. It is initialized
71 // from the context, and then is set/reset as needed by Attr as it
72 // visits all the various parts of the trees during attribution.
73 private Lint lint;
74
75 public static Check instance(Context context) {
76 Check instance = context.get(checkKey);
77 if (instance == null)
78 instance = new Check(context);
79 return instance;
80 }
81
82 protected Check(Context context) {
83 context.put(checkKey, this);
84
85 names = Names.instance(context);
86 log = Log.instance(context);
87 syms = Symtab.instance(context);
88 infer = Infer.instance(context);
89 this.types = Types.instance(context);
90 diags = JCDiagnostic.Factory.instance(context);
91 Options options = Options.instance(context);
92 lint = Lint.instance(context);
93 treeinfo = TreeInfo.instance(context);
94
95 Source source = Source.instance(context);
96 allowGenerics = source.allowGenerics();
97 allowAnnotations = source.allowAnnotations();
98 allowCovariantReturns = source.allowCovariantReturns();
99 complexInference = options.get("-complexinference") != null;
100 skipAnnotations = options.get("skipAnnotations") != null;
101 warnOnSyntheticConflicts = options.get("warnOnSyntheticConflicts") != null;
102 suppressAbortOnBadClassFile = options.get("suppressAbortOnBadClassFile") != null;
103
104 Target target = Target.instance(context);
105 syntheticNameChar = target.syntheticNameChar();
106
107 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
108 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
109 boolean verboseVarargs = lint.isEnabled(LintCategory.VARARGS);
110 boolean verboseSunApi = lint.isEnabled(LintCategory.SUNAPI);
111 boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
112
113 deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
114 enforceMandatoryWarnings, "deprecated");
115 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
116 enforceMandatoryWarnings, "unchecked");
117 unsafeVarargsHandler = new MandatoryWarningHandler(log, verboseVarargs,
118 enforceMandatoryWarnings, "varargs");
119 sunApiHandler = new MandatoryWarningHandler(log, verboseSunApi,
120 enforceMandatoryWarnings, "sunapi");
121 }
122
123 /** Switch: generics enabled?
124 */
125 boolean allowGenerics;
126
127 /** Switch: annotations enabled?
128 */
129 boolean allowAnnotations;
130
131 /** Switch: covariant returns enabled?
132 */
133 boolean allowCovariantReturns;
134
135 /** Switch: -complexinference option set?
136 */
137 boolean complexInference;
138
139 /** Character for synthetic names
140 */
141 char syntheticNameChar;
142
143 /** A table mapping flat names of all compiled classes in this run to their
144 * symbols; maintained from outside.
145 */
146 public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
147
148 /** A handler for messages about deprecated usage.
149 */
150 private MandatoryWarningHandler deprecationHandler;
151
152 /** A handler for messages about unchecked or unsafe usage.
153 */
154 private MandatoryWarningHandler uncheckedHandler;
155
156 /** A handler for messages about unchecked or unsafe vararg method decl.
157 */
158 private MandatoryWarningHandler unsafeVarargsHandler;
159
160 /** A handler for messages about using proprietary API.
161 */
162 private MandatoryWarningHandler sunApiHandler;
163
164 /* *************************************************************************
165 * Errors and Warnings
166 **************************************************************************/
167
168 Lint setLint(Lint newLint) {
169 Lint prev = lint;
170 lint = newLint;
171 return prev;
172 }
173
174 /** Warn about deprecated symbol.
175 * @param pos Position to be used for error reporting.
176 * @param sym The deprecated symbol.
177 */
178 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
179 if (!lint.isSuppressed(LintCategory.DEPRECATION))
180 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
181 }
182
183 /** Warn about unchecked operation.
184 * @param pos Position to be used for error reporting.
185 * @param msg A string describing the problem.
186 */
187 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
188 if (!lint.isSuppressed(LintCategory.UNCHECKED))
189 uncheckedHandler.report(pos, msg, args);
190 }
191
192 /** Warn about unsafe vararg method decl.
193 * @param pos Position to be used for error reporting.
194 * @param sym The deprecated symbol.
195 */
196 void warnUnsafeVararg(DiagnosticPosition pos, Type elemType) {
197 if (!lint.isSuppressed(LintCategory.VARARGS))
198 unsafeVarargsHandler.report(pos, "varargs.non.reifiable.type", elemType);
199 }
200
201 /** Warn about using proprietary API.
202 * @param pos Position to be used for error reporting.
203 * @param msg A string describing the problem.
204 */
205 public void warnSunApi(DiagnosticPosition pos, String msg, Object... args) {
206 if (!lint.isSuppressed(LintCategory.SUNAPI))
207 sunApiHandler.report(pos, msg, args);
208 }
209
210 public void warnStatic(DiagnosticPosition pos, String msg, Object... args) {
211 if (lint.isEnabled(LintCategory.STATIC))
212 log.warning(pos, msg, args);
213 }
214
215 /**
216 * Report any deferred diagnostics.
217 */
218 public void reportDeferredDiagnostics() {
219 deprecationHandler.reportDeferredDiagnostic();
220 uncheckedHandler.reportDeferredDiagnostic();
221 unsafeVarargsHandler.reportDeferredDiagnostic();
222 sunApiHandler.reportDeferredDiagnostic();
223 }
224
225
226 /** Report a failure to complete a class.
227 * @param pos Position to be used for error reporting.
228 * @param ex The failure to report.
229 */
230 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
231 log.error(pos, "cant.access", ex.sym, ex.getDetailValue());
232 if (ex instanceof ClassReader.BadClassFile
233 && !suppressAbortOnBadClassFile) throw new Abort();
234 else return syms.errType;
235 }
236
237 /** Report a type error.
238 * @param pos Position to be used for error reporting.
239 * @param problem A string describing the error.
240 * @param found The type that was found.
241 * @param req The type that was required.
242 */
243 Type typeError(DiagnosticPosition pos, Object problem, Type found, Type req) {
244 log.error(pos, "prob.found.req",
245 problem, found, req);
246 return types.createErrorType(found);
247 }
248
249 Type typeError(DiagnosticPosition pos, String problem, Type found, Type req, Object explanation) {
250 log.error(pos, "prob.found.req.1", problem, found, req, explanation);
251 return types.createErrorType(found);
252 }
253
254 /** Report an error that wrong type tag was found.
255 * @param pos Position to be used for error reporting.
256 * @param required An internationalized string describing the type tag
257 * required.
258 * @param found The type that was found.
259 */
260 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
261 // this error used to be raised by the parser,
262 // but has been delayed to this point:
263 if (found instanceof Type && ((Type)found).tag == VOID) {
264 log.error(pos, "illegal.start.of.type");
265 return syms.errType;
266 }
267 log.error(pos, "type.found.req", found, required);
268 return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
269 }
270
271 /** Report an error that symbol cannot be referenced before super
272 * has been called.
273 * @param pos Position to be used for error reporting.
274 * @param sym The referenced symbol.
275 */
276 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
277 log.error(pos, "cant.ref.before.ctor.called", sym);
278 }
279
280 /** Report duplicate declaration error.
281 */
282 void duplicateError(DiagnosticPosition pos, Symbol sym) {
283 if (!sym.type.isErroneous()) {
284 log.error(pos, "already.defined", sym, sym.location());
285 }
286 }
287
288 /** Report array/varargs duplicate declaration
289 */
290 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
291 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
292 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
293 }
294 }
295
296 /* ************************************************************************
297 * duplicate declaration checking
298 *************************************************************************/
299
300 /** Check that variable does not hide variable with same name in
301 * immediately enclosing local scope.
302 * @param pos Position for error reporting.
303 * @param v The symbol.
304 * @param s The scope.
305 */
306 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
307 if (s.next != null) {
308 for (Scope.Entry e = s.next.lookup(v.name);
309 e.scope != null && e.sym.owner == v.owner;
310 e = e.next()) {
311 if (e.sym.kind == VAR &&
312 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
313 v.name != names.error) {
314 duplicateError(pos, e.sym);
315 return;
316 }
317 }
318 }
319 }
320
321 /** Check that a class or interface does not hide a class or
322 * interface with same name in immediately enclosing local scope.
323 * @param pos Position for error reporting.
324 * @param c The symbol.
325 * @param s The scope.
326 */
327 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
328 if (s.next != null) {
329 for (Scope.Entry e = s.next.lookup(c.name);
330 e.scope != null && e.sym.owner == c.owner;
331 e = e.next()) {
332 if (e.sym.kind == TYP &&
333 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
334 c.name != names.error) {
335 duplicateError(pos, e.sym);
336 return;
337 }
338 }
339 }
340 }
341
342 /** Check that class does not have the same name as one of
343 * its enclosing classes, or as a class defined in its enclosing scope.
344 * return true if class is unique in its enclosing scope.
345 * @param pos Position for error reporting.
346 * @param name The class name.
347 * @param s The enclosing scope.
348 */
349 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
350 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
351 if (e.sym.kind == TYP && e.sym.name != names.error) {
352 duplicateError(pos, e.sym);
353 return false;
354 }
355 }
356 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
357 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
358 duplicateError(pos, sym);
359 return true;
360 }
361 }
362 return true;
363 }
364
365 /* *************************************************************************
366 * Class name generation
367 **************************************************************************/
368
369 /** Return name of local class.
370 * This is of the form <enclClass> $ n <classname>
371 * where
372 * enclClass is the flat name of the enclosing class,
373 * classname is the simple name of the local class
374 */
375 Name localClassName(ClassSymbol c) {
376 for (int i=1; ; i++) {
377 Name flatname = names.
378 fromString("" + c.owner.enclClass().flatname +
379 syntheticNameChar + i +
380 c.name);
381 if (compiled.get(flatname) == null) return flatname;
382 }
383 }
384
385 /* *************************************************************************
386 * Type Checking
387 **************************************************************************/
388
389 /** Check that a given type is assignable to a given proto-type.
390 * If it is, return the type, otherwise return errType.
391 * @param pos Position to be used for error reporting.
392 * @param found The type that was found.
393 * @param req The type that was required.
394 */
395 Type checkType(DiagnosticPosition pos, Type found, Type req) {
396 if (req.tag == ERROR)
397 return req;
398 if (found.tag == FORALL)
399 return instantiatePoly(pos, (ForAll)found, req, convertWarner(pos, found, req));
400 if (req.tag == NONE)
401 return found;
402 if (types.isAssignable(found, req, convertWarner(pos, found, req)))
403 return found;
404 if (found.tag <= DOUBLE && req.tag <= DOUBLE)
405 return typeError(pos, diags.fragment("possible.loss.of.precision"), found, req);
406 if (found.isSuperBound()) {
407 log.error(pos, "assignment.from.super-bound", found);
408 return types.createErrorType(found);
409 }
410 if (req.isExtendsBound()) {
411 log.error(pos, "assignment.to.extends-bound", req);
412 return types.createErrorType(found);
413 }
414 return typeError(pos, diags.fragment("incompatible.types"), found, req);
415 }
416
417 /** Instantiate polymorphic type to some prototype, unless
418 * prototype is `anyPoly' in which case polymorphic type
419 * is returned unchanged.
420 */
421 Type instantiatePoly(DiagnosticPosition pos, ForAll t, Type pt, Warner warn) throws Infer.NoInstanceException {
422 if (pt == Infer.anyPoly && complexInference) {
423 return t;
424 } else if (pt == Infer.anyPoly || pt.tag == NONE) {
425 Type newpt = t.qtype.tag <= VOID ? t.qtype : syms.objectType;
426 return instantiatePoly(pos, t, newpt, warn);
427 } else if (pt.tag == ERROR) {
428 return pt;
429 } else {
430 try {
431 return infer.instantiateExpr(t, pt, warn);
432 } catch (Infer.NoInstanceException ex) {
433 if (ex.isAmbiguous) {
434 JCDiagnostic d = ex.getDiagnostic();
435 log.error(pos,
436 "undetermined.type" + (d!=null ? ".1" : ""),
437 t, d);
438 return types.createErrorType(pt);
439 } else {
440 JCDiagnostic d = ex.getDiagnostic();
441 return typeError(pos,
442 diags.fragment("incompatible.types" + (d!=null ? ".1" : ""), d),
443 t, pt);
444 }
445 } catch (Infer.InvalidInstanceException ex) {
446 JCDiagnostic d = ex.getDiagnostic();
447 log.error(pos, "invalid.inferred.types", t.tvars, d);
448 return types.createErrorType(pt);
449 }
450 }
451 }
452
453 /** Check that a given type can be cast to a given target type.
454 * Return the result of the cast.
455 * @param pos Position to be used for error reporting.
456 * @param found The type that is being cast.
457 * @param req The target type of the cast.
458 */
459 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
460 if (found.tag == FORALL) {
461 instantiatePoly(pos, (ForAll) found, req, castWarner(pos, found, req));
462 return req;
463 } else if (types.isCastable(found, req, castWarner(pos, found, req))) {
464 return req;
465 } else {
466 return typeError(pos,
467 diags.fragment("inconvertible.types"),
468 found, req);
469 }
470 }
471 //where
472 /** Is type a type variable, or a (possibly multi-dimensional) array of
473 * type variables?
474 */
475 boolean isTypeVar(Type t) {
476 return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
477 }
478
479 /** Check that a type is within some bounds.
480 *
481 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
482 * type argument.
483 * @param pos Position to be used for error reporting.
484 * @param a The type that should be bounded by bs.
485 * @param bs The bound.
486 */
487 private void checkExtends(DiagnosticPosition pos, Type a, TypeVar bs) {
488 if (a.isUnbound()) {
489 return;
490 } else if (a.tag != WILDCARD) {
491 a = types.upperBound(a);
492 for (List<Type> l = types.getBounds(bs); l.nonEmpty(); l = l.tail) {
493 if (!types.isSubtype(a, l.head)) {
494 log.error(pos, "not.within.bounds", a);
495 return;
496 }
497 }
498 } else if (a.isExtendsBound()) {
499 if (!types.isCastable(bs.getUpperBound(), types.upperBound(a), Warner.noWarnings))
500 log.error(pos, "not.within.bounds", a);
501 } else if (a.isSuperBound()) {
502 if (types.notSoftSubtype(types.lowerBound(a), bs.getUpperBound()))
503 log.error(pos, "not.within.bounds", a);
504 }
505 }
506
507 /** Check that a type is within some bounds.
508 *
509 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
510 * type argument.
511 * @param pos Position to be used for error reporting.
512 * @param a The type that should be bounded by bs.
513 * @param bs The bound.
514 */
515 private void checkCapture(JCTypeApply tree) {
516 List<JCExpression> args = tree.getTypeArguments();
517 for (Type arg : types.capture(tree.type).getTypeArguments()) {
518 if (arg.tag == TYPEVAR && arg.getUpperBound().isErroneous()) {
519 log.error(args.head.pos, "not.within.bounds", args.head.type);
520 break;
521 }
522 args = args.tail;
523 }
524 }
525
526 /** Check that type is different from 'void'.
527 * @param pos Position to be used for error reporting.
528 * @param t The type to be checked.
529 */
530 Type checkNonVoid(DiagnosticPosition pos, Type t) {
531 if (t.tag == VOID) {
532 log.error(pos, "void.not.allowed.here");
533 return types.createErrorType(t);
534 } else {
535 return t;
536 }
537 }
538
539 /** Check that type is a class or interface type.
540 * @param pos Position to be used for error reporting.
541 * @param t The type to be checked.
542 */
543 Type checkClassType(DiagnosticPosition pos, Type t) {
544 if (t.tag != CLASS && t.tag != ERROR)
545 return typeTagError(pos,
546 diags.fragment("type.req.class"),
547 (t.tag == TYPEVAR)
548 ? diags.fragment("type.parameter", t)
549 : t);
550 else
551 return t;
552 }
553
554 /** Check that type is a class or interface type.
555 * @param pos Position to be used for error reporting.
556 * @param t The type to be checked.
557 * @param noBounds True if type bounds are illegal here.
558 */
559 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
560 t = checkClassType(pos, t);
561 if (noBounds && t.isParameterized()) {
562 List<Type> args = t.getTypeArguments();
563 while (args.nonEmpty()) {
564 if (args.head.tag == WILDCARD)
565 return typeTagError(pos,
566 Log.getLocalizedString("type.req.exact"),
567 args.head);
568 args = args.tail;
569 }
570 }
571 return t;
572 }
573
574 /** Check that type is a reifiable class, interface or array type.
575 * @param pos Position to be used for error reporting.
576 * @param t The type to be checked.
577 */
578 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
579 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
580 return typeTagError(pos,
581 diags.fragment("type.req.class.array"),
582 t);
583 } else if (!types.isReifiable(t)) {
584 log.error(pos, "illegal.generic.type.for.instof");
585 return types.createErrorType(t);
586 } else {
587 return t;
588 }
589 }
590
591 /** Check that type is a reference type, i.e. a class, interface or array type
592 * or a type variable.
593 * @param pos Position to be used for error reporting.
594 * @param t The type to be checked.
595 */
596 Type checkRefType(DiagnosticPosition pos, Type t) {
597 switch (t.tag) {
598 case CLASS:
599 case ARRAY:
600 case TYPEVAR:
601 case WILDCARD:
602 case ERROR:
603 return t;
604 default:
605 return typeTagError(pos,
606 diags.fragment("type.req.ref"),
607 t);
608 }
609 }
610
611 /** Check that each type is a reference type, i.e. a class, interface or array type
612 * or a type variable.
613 * @param trees Original trees, used for error reporting.
614 * @param types The types to be checked.
615 */
616 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
617 List<JCExpression> tl = trees;
618 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
619 l.head = checkRefType(tl.head.pos(), l.head);
620 tl = tl.tail;
621 }
622 return types;
623 }
624
625 /** Check that type is a null or reference type.
626 * @param pos Position to be used for error reporting.
627 * @param t The type to be checked.
628 */
629 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
630 switch (t.tag) {
631 case CLASS:
632 case ARRAY:
633 case TYPEVAR:
634 case WILDCARD:
635 case BOT:
636 case ERROR:
637 return t;
638 default:
639 return typeTagError(pos,
640 diags.fragment("type.req.ref"),
641 t);
642 }
643 }
644
645 /** Check that flag set does not contain elements of two conflicting sets. s
646 * Return true if it doesn't.
647 * @param pos Position to be used for error reporting.
648 * @param flags The set of flags to be checked.
649 * @param set1 Conflicting flags set #1.
650 * @param set2 Conflicting flags set #2.
651 */
652 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
653 if ((flags & set1) != 0 && (flags & set2) != 0) {
654 log.error(pos,
655 "illegal.combination.of.modifiers",
656 asFlagSet(TreeInfo.firstFlag(flags & set1)),
657 asFlagSet(TreeInfo.firstFlag(flags & set2)));
658 return false;
659 } else
660 return true;
661 }
662
663 /** Check that the type inferred using the diamond operator does not contain
664 * non-denotable types such as captured types or intersection types.
665 * @param t the type inferred using the diamond operator
666 */
667 List<Type> checkDiamond(ClassType t) {
668 DiamondTypeChecker dtc = new DiamondTypeChecker();
669 ListBuffer<Type> buf = ListBuffer.lb();
670 for (Type arg : t.getTypeArguments()) {
671 if (!dtc.visit(arg, null)) {
672 buf.append(arg);
673 }
674 }
675 return buf.toList();
676 }
677
678 static class DiamondTypeChecker extends Types.SimpleVisitor<Boolean, Void> {
679 public Boolean visitType(Type t, Void s) {
680 return true;
681 }
682 @Override
683 public Boolean visitClassType(ClassType t, Void s) {
684 if (t.isCompound()) {
685 return false;
686 }
687 for (Type targ : t.getTypeArguments()) {
688 if (!visit(targ, s)) {
689 return false;
690 }
691 }
692 return true;
693 }
694 @Override
695 public Boolean visitCapturedType(CapturedType t, Void s) {
696 return false;
697 }
698 }
699
700 void checkVarargMethodDecl(JCMethodDecl tree) {
701 MethodSymbol m = tree.sym;
702 //check the element type of the vararg
703 if (m.isVarArgs()) {
704 Type varargElemType = types.elemtype(tree.params.last().type);
705 if (!types.isReifiable(varargElemType)) {
706 warnUnsafeVararg(tree.params.head.pos(), varargElemType);
707 }
708 }
709 }
710
711 /**
712 * Check that vararg method call is sound
713 * @param pos Position to be used for error reporting.
714 * @param argtypes Actual arguments supplied to vararg method.
715 */
716 void checkVararg(DiagnosticPosition pos, List<Type> argtypes, Symbol msym, Env<AttrContext> env) {
717 Env<AttrContext> calleeLintEnv = env;
718 while (calleeLintEnv.info.lint == null)
719 calleeLintEnv = calleeLintEnv.next;
720 Lint calleeLint = calleeLintEnv.info.lint.augment(msym.attributes_field, msym.flags());
721 Type argtype = argtypes.last();
722 if (!types.isReifiable(argtype) && !calleeLint.isSuppressed(Lint.LintCategory.VARARGS)) {
723 warnUnchecked(pos,
724 "unchecked.generic.array.creation",
725 argtype);
726 }
727 }
728
729 /** Check that given modifiers are legal for given symbol and
730 * return modifiers together with any implicit modififiers for that symbol.
731 * Warning: we can't use flags() here since this method
732 * is called during class enter, when flags() would cause a premature
733 * completion.
734 * @param pos Position to be used for error reporting.
735 * @param flags The set of modifiers given in a definition.
736 * @param sym The defined symbol.
737 */
738 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
739 long mask;
740 long implicit = 0;
741 switch (sym.kind) {
742 case VAR:
743 if (sym.owner.kind != TYP)
744 mask = LocalVarFlags;
745 else if ((sym.owner.flags_field & INTERFACE) != 0)
746 mask = implicit = InterfaceVarFlags;
747 else
748 mask = VarFlags;
749 break;
750 case MTH:
751 if (sym.name == names.init) {
752 if ((sym.owner.flags_field & ENUM) != 0) {
753 // enum constructors cannot be declared public or
754 // protected and must be implicitly or explicitly
755 // private
756 implicit = PRIVATE;
757 mask = PRIVATE;
758 } else
759 mask = ConstructorFlags;
760 } else if ((sym.owner.flags_field & INTERFACE) != 0)
761 mask = implicit = InterfaceMethodFlags;
762 else {
763 mask = MethodFlags;
764 }
765 // Imply STRICTFP if owner has STRICTFP set.
766 if (((flags|implicit) & Flags.ABSTRACT) == 0)
767 implicit |= sym.owner.flags_field & STRICTFP;
768 break;
769 case TYP:
770 if (sym.isLocal()) {
771 mask = LocalClassFlags;
772 if (sym.name.isEmpty()) { // Anonymous class
773 // Anonymous classes in static methods are themselves static;
774 // that's why we admit STATIC here.
775 mask |= STATIC;
776 // JLS: Anonymous classes are final.
777 implicit |= FINAL;
778 }
779 if ((sym.owner.flags_field & STATIC) == 0 &&
780 (flags & ENUM) != 0)
781 log.error(pos, "enums.must.be.static");
782 } else if (sym.owner.kind == TYP) {
783 mask = MemberClassFlags;
784 if (sym.owner.owner.kind == PCK ||
785 (sym.owner.flags_field & STATIC) != 0)
786 mask |= STATIC;
787 else if ((flags & ENUM) != 0)
788 log.error(pos, "enums.must.be.static");
789 // Nested interfaces and enums are always STATIC (Spec ???)
790 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
791 } else {
792 mask = ClassFlags;
793 }
794 // Interfaces are always ABSTRACT
795 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
796
797 if ((flags & ENUM) != 0) {
798 // enums can't be declared abstract or final
799 mask &= ~(ABSTRACT | FINAL);
800 implicit |= implicitEnumFinalFlag(tree);
801 }
802 // Imply STRICTFP if owner has STRICTFP set.
803 implicit |= sym.owner.flags_field & STRICTFP;
804 break;
805 default:
806 throw new AssertionError();
807 }
808 long illegal = flags & StandardFlags & ~mask;
809 if (illegal != 0) {
810 if ((illegal & INTERFACE) != 0) {
811 log.error(pos, "intf.not.allowed.here");
812 mask |= INTERFACE;
813 }
814 else {
815 log.error(pos,
816 "mod.not.allowed.here", asFlagSet(illegal));
817 }
818 }
819 else if ((sym.kind == TYP ||
820 // ISSUE: Disallowing abstract&private is no longer appropriate
821 // in the presence of inner classes. Should it be deleted here?
822 checkDisjoint(pos, flags,
823 ABSTRACT,
824 PRIVATE | STATIC))
825 &&
826 checkDisjoint(pos, flags,
827 ABSTRACT | INTERFACE,
828 FINAL | NATIVE | SYNCHRONIZED)
829 &&
830 checkDisjoint(pos, flags,
831 PUBLIC,
832 PRIVATE | PROTECTED)
833 &&
834 checkDisjoint(pos, flags,
835 PRIVATE,
836 PUBLIC | PROTECTED)
837 &&
838 checkDisjoint(pos, flags,
839 FINAL,
840 VOLATILE)
841 &&
842 (sym.kind == TYP ||
843 checkDisjoint(pos, flags,
844 ABSTRACT | NATIVE,
845 STRICTFP))) {
846 // skip
847 }
848 return flags & (mask | ~StandardFlags) | implicit;
849 }
850
851
852 /** Determine if this enum should be implicitly final.
853 *
854 * If the enum has no specialized enum contants, it is final.
855 *
856 * If the enum does have specialized enum contants, it is
857 * <i>not</i> final.
858 */
859 private long implicitEnumFinalFlag(JCTree tree) {
860 if (tree.getTag() != JCTree.CLASSDEF) return 0;
861 class SpecialTreeVisitor extends JCTree.Visitor {
862 boolean specialized;
863 SpecialTreeVisitor() {
864 this.specialized = false;
865 };
866
867 @Override
868 public void visitTree(JCTree tree) { /* no-op */ }
869
870 @Override
871 public void visitVarDef(JCVariableDecl tree) {
872 if ((tree.mods.flags & ENUM) != 0) {
873 if (tree.init instanceof JCNewClass &&
874 ((JCNewClass) tree.init).def != null) {
875 specialized = true;
876 }
877 }
878 }
879 }
880
881 SpecialTreeVisitor sts = new SpecialTreeVisitor();
882 JCClassDecl cdef = (JCClassDecl) tree;
883 for (JCTree defs: cdef.defs) {
884 defs.accept(sts);
885 if (sts.specialized) return 0;
886 }
887 return FINAL;
888 }
889
890 /* *************************************************************************
891 * Type Validation
892 **************************************************************************/
893
894 /** Validate a type expression. That is,
895 * check that all type arguments of a parametric type are within
896 * their bounds. This must be done in a second phase after type attributon
897 * since a class might have a subclass as type parameter bound. E.g:
898 *
899 * class B<A extends C> { ... }
900 * class C extends B<C> { ... }
901 *
902 * and we can't make sure that the bound is already attributed because
903 * of possible cycles.
904 */
905 private Validator validator = new Validator();
906
907 /** Visitor method: Validate a type expression, if it is not null, catching
908 * and reporting any completion failures.
909 */
910 void validate(JCTree tree, Env<AttrContext> env) {
911 try {
912 if (tree != null) {
913 validator.env = env;
914 tree.accept(validator);
915 checkRaw(tree, env);
916 }
917 } catch (CompletionFailure ex) {
918 completionError(tree.pos(), ex);
919 }
920 }
921 //where
922 void checkRaw(JCTree tree, Env<AttrContext> env) {
923 if (lint.isEnabled(Lint.LintCategory.RAW) &&
924 tree.type.tag == CLASS &&
925 !TreeInfo.isDiamond(tree) &&
926 !env.enclClass.name.isEmpty() && //anonymous or intersection
927 tree.type.isRaw()) {
928 log.warning(tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
929 }
930 }
931
932 /** Visitor method: Validate a list of type expressions.
933 */
934 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
935 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
936 validate(l.head, env);
937 }
938
939 /** A visitor class for type validation.
940 */
941 class Validator extends JCTree.Visitor {
942
943 @Override
944 public void visitTypeArray(JCArrayTypeTree tree) {
945 validate(tree.elemtype, env);
946 }
947
948 @Override
949 public void visitTypeApply(JCTypeApply tree) {
950 if (tree.type.tag == CLASS) {
951 List<Type> formals = tree.type.tsym.type.allparams();
952 List<Type> actuals = tree.type.allparams();
953 List<JCExpression> args = tree.arguments;
954 List<Type> forms = tree.type.tsym.type.getTypeArguments();
955 ListBuffer<Type> tvars_buf = new ListBuffer<Type>();
956
957 // For matching pairs of actual argument types `a' and
958 // formal type parameters with declared bound `b' ...
959 while (args.nonEmpty() && forms.nonEmpty()) {
960 validate(args.head, env);
961
962 // exact type arguments needs to know their
963 // bounds (for upper and lower bound
964 // calculations). So we create new TypeVars with
965 // bounds substed with actuals.
966 tvars_buf.append(types.substBound(((TypeVar)forms.head),
967 formals,
968 actuals));
969
970 args = args.tail;
971 forms = forms.tail;
972 }
973
974 args = tree.arguments;
975 List<Type> tvars_cap = types.substBounds(formals,
976 formals,
977 types.capture(tree.type).allparams());
978 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
979 // Let the actual arguments know their bound
980 args.head.type.withTypeVar((TypeVar)tvars_cap.head);
981 args = args.tail;
982 tvars_cap = tvars_cap.tail;
983 }
984
985 args = tree.arguments;
986 List<Type> tvars = tvars_buf.toList();
987
988 while (args.nonEmpty() && tvars.nonEmpty()) {
989 Type actual = types.subst(args.head.type,
990 tree.type.tsym.type.getTypeArguments(),
991 tvars_buf.toList());
992 checkExtends(args.head.pos(),
993 actual,
994 (TypeVar)tvars.head);
995 args = args.tail;
996 tvars = tvars.tail;
997 }
998
999 checkCapture(tree);
1000
1001 // Check that this type is either fully parameterized, or
1002 // not parameterized at all.
1003 if (tree.type.getEnclosingType().isRaw())
1004 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
1005 if (tree.clazz.getTag() == JCTree.SELECT)
1006 visitSelectInternal((JCFieldAccess)tree.clazz);
1007 }
1008 }
1009
1010 @Override
1011 public void visitTypeParameter(JCTypeParameter tree) {
1012 validate(tree.bounds, env);
1013 checkClassBounds(tree.pos(), tree.type);
1014 }
1015
1016 @Override
1017 public void visitWildcard(JCWildcard tree) {
1018 if (tree.inner != null)
1019 validate(tree.inner, env);
1020 }
1021
1022 @Override
1023 public void visitSelect(JCFieldAccess tree) {
1024 if (tree.type.tag == CLASS) {
1025 visitSelectInternal(tree);
1026
1027 // Check that this type is either fully parameterized, or
1028 // not parameterized at all.
1029 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1030 log.error(tree.pos(), "improperly.formed.type.param.missing");
1031 }
1032 }
1033 public void visitSelectInternal(JCFieldAccess tree) {
1034 if (tree.type.tsym.isStatic() &&
1035 tree.selected.type.isParameterized()) {
1036 // The enclosing type is not a class, so we are
1037 // looking at a static member type. However, the
1038 // qualifying expression is parameterized.
1039 log.error(tree.pos(), "cant.select.static.class.from.param.type");
1040 } else {
1041 // otherwise validate the rest of the expression
1042 tree.selected.accept(this);
1043 }
1044 }
1045
1046 @Override
1047 public void visitAnnotatedType(JCAnnotatedType tree) {
1048 tree.underlyingType.accept(this);
1049 }
1050
1051 /** Default visitor method: do nothing.
1052 */
1053 @Override
1054 public void visitTree(JCTree tree) {
1055 }
1056
1057 Env<AttrContext> env;
1058 }
1059
1060 /* *************************************************************************
1061 * Exception checking
1062 **************************************************************************/
1063
1064 /* The following methods treat classes as sets that contain
1065 * the class itself and all their subclasses
1066 */
1067
1068 /** Is given type a subtype of some of the types in given list?
1069 */
1070 boolean subset(Type t, List<Type> ts) {
1071 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1072 if (types.isSubtype(t, l.head)) return true;
1073 return false;
1074 }
1075
1076 /** Is given type a subtype or supertype of
1077 * some of the types in given list?
1078 */
1079 boolean intersects(Type t, List<Type> ts) {
1080 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1081 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1082 return false;
1083 }
1084
1085 /** Add type set to given type list, unless it is a subclass of some class
1086 * in the list.
1087 */
1088 List<Type> incl(Type t, List<Type> ts) {
1089 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1090 }
1091
1092 /** Remove type set from type set list.
1093 */
1094 List<Type> excl(Type t, List<Type> ts) {
1095 if (ts.isEmpty()) {
1096 return ts;
1097 } else {
1098 List<Type> ts1 = excl(t, ts.tail);
1099 if (types.isSubtype(ts.head, t)) return ts1;
1100 else if (ts1 == ts.tail) return ts;
1101 else return ts1.prepend(ts.head);
1102 }
1103 }
1104
1105 /** Form the union of two type set lists.
1106 */
1107 List<Type> union(List<Type> ts1, List<Type> ts2) {
1108 List<Type> ts = ts1;
1109 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1110 ts = incl(l.head, ts);
1111 return ts;
1112 }
1113
1114 /** Form the difference of two type lists.
1115 */
1116 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1117 List<Type> ts = ts1;
1118 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1119 ts = excl(l.head, ts);
1120 return ts;
1121 }
1122
1123 /** Form the intersection of two type lists.
1124 */
1125 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1126 List<Type> ts = List.nil();
1127 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1128 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1129 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1130 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1131 return ts;
1132 }
1133
1134 /** Is exc an exception symbol that need not be declared?
1135 */
1136 boolean isUnchecked(ClassSymbol exc) {
1137 return
1138 exc.kind == ERR ||
1139 exc.isSubClass(syms.errorType.tsym, types) ||
1140 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1141 }
1142
1143 /** Is exc an exception type that need not be declared?
1144 */
1145 boolean isUnchecked(Type exc) {
1146 return
1147 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
1148 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
1149 exc.tag == BOT;
1150 }
1151
1152 /** Same, but handling completion failures.
1153 */
1154 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1155 try {
1156 return isUnchecked(exc);
1157 } catch (CompletionFailure ex) {
1158 completionError(pos, ex);
1159 return true;
1160 }
1161 }
1162
1163 /** Is exc handled by given exception list?
1164 */
1165 boolean isHandled(Type exc, List<Type> handled) {
1166 return isUnchecked(exc) || subset(exc, handled);
1167 }
1168
1169 /** Return all exceptions in thrown list that are not in handled list.
1170 * @param thrown The list of thrown exceptions.
1171 * @param handled The list of handled exceptions.
1172 */
1173 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1174 List<Type> unhandled = List.nil();
1175 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1176 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1177 return unhandled;
1178 }
1179
1180 /* *************************************************************************
1181 * Overriding/Implementation checking
1182 **************************************************************************/
1183
1184 /** The level of access protection given by a flag set,
1185 * where PRIVATE is highest and PUBLIC is lowest.
1186 */
1187 static int protection(long flags) {
1188 switch ((short)(flags & AccessFlags)) {
1189 case PRIVATE: return 3;
1190 case PROTECTED: return 1;
1191 default:
1192 case PUBLIC: return 0;
1193 case 0: return 2;
1194 }
1195 }
1196
1197 /** A customized "cannot override" error message.
1198 * @param m The overriding method.
1199 * @param other The overridden method.
1200 * @return An internationalized string.
1201 */
1202 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1203 String key;
1204 if ((other.owner.flags() & INTERFACE) == 0)
1205 key = "cant.override";
1206 else if ((m.owner.flags() & INTERFACE) == 0)
1207 key = "cant.implement";
1208 else
1209 key = "clashes.with";
1210 return diags.fragment(key, m, m.location(), other, other.location());
1211 }
1212
1213 /** A customized "override" warning message.
1214 * @param m The overriding method.
1215 * @param other The overridden method.
1216 * @return An internationalized string.
1217 */
1218 Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1219 String key;
1220 if ((other.owner.flags() & INTERFACE) == 0)
1221 key = "unchecked.override";
1222 else if ((m.owner.flags() & INTERFACE) == 0)
1223 key = "unchecked.implement";
1224 else
1225 key = "unchecked.clash.with";
1226 return diags.fragment(key, m, m.location(), other, other.location());
1227 }
1228
1229 /** A customized "override" warning message.
1230 * @param m The overriding method.
1231 * @param other The overridden method.
1232 * @return An internationalized string.
1233 */
1234 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1235 String key;
1236 if ((other.owner.flags() & INTERFACE) == 0)
1237 key = "varargs.override";
1238 else if ((m.owner.flags() & INTERFACE) == 0)
1239 key = "varargs.implement";
1240 else
1241 key = "varargs.clash.with";
1242 return diags.fragment(key, m, m.location(), other, other.location());
1243 }
1244
1245 /** Check that this method conforms with overridden method 'other'.
1246 * where `origin' is the class where checking started.
1247 * Complications:
1248 * (1) Do not check overriding of synthetic methods
1249 * (reason: they might be final).
1250 * todo: check whether this is still necessary.
1251 * (2) Admit the case where an interface proxy throws fewer exceptions
1252 * than the method it implements. Augment the proxy methods with the
1253 * undeclared exceptions in this case.
1254 * (3) When generics are enabled, admit the case where an interface proxy
1255 * has a result type
1256 * extended by the result type of the method it implements.
1257 * Change the proxies result type to the smaller type in this case.
1258 *
1259 * @param tree The tree from which positions
1260 * are extracted for errors.
1261 * @param m The overriding method.
1262 * @param other The overridden method.
1263 * @param origin The class of which the overriding method
1264 * is a member.
1265 */
1266 void checkOverride(JCTree tree,
1267 MethodSymbol m,
1268 MethodSymbol other,
1269 ClassSymbol origin) {
1270 // Don't check overriding of synthetic methods or by bridge methods.
1271 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1272 return;
1273 }
1274
1275 // Error if static method overrides instance method (JLS 8.4.6.2).
1276 if ((m.flags() & STATIC) != 0 &&
1277 (other.flags() & STATIC) == 0) {
1278 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1279 cannotOverride(m, other));
1280 return;
1281 }
1282
1283 // Error if instance method overrides static or final
1284 // method (JLS 8.4.6.1).
1285 if ((other.flags() & FINAL) != 0 ||
1286 (m.flags() & STATIC) == 0 &&
1287 (other.flags() & STATIC) != 0) {
1288 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1289 cannotOverride(m, other),
1290 asFlagSet(other.flags() & (FINAL | STATIC)));
1291 return;
1292 }
1293
1294 if ((m.owner.flags() & ANNOTATION) != 0) {
1295 // handled in validateAnnotationMethod
1296 return;
1297 }
1298
1299 // Error if overriding method has weaker access (JLS 8.4.6.3).
1300 if ((origin.flags() & INTERFACE) == 0 &&
1301 protection(m.flags()) > protection(other.flags())) {
1302 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1303 cannotOverride(m, other),
1304 other.flags() == 0 ?
1305 Flag.PACKAGE :
1306 asFlagSet(other.flags() & AccessFlags));
1307 return;
1308 }
1309
1310 Type mt = types.memberType(origin.type, m);
1311 Type ot = types.memberType(origin.type, other);
1312 // Error if overriding result type is different
1313 // (or, in the case of generics mode, not a subtype) of
1314 // overridden result type. We have to rename any type parameters
1315 // before comparing types.
1316 List<Type> mtvars = mt.getTypeArguments();
1317 List<Type> otvars = ot.getTypeArguments();
1318 Type mtres = mt.getReturnType();
1319 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1320
1321 overrideWarner.warned = false;
1322 boolean resultTypesOK =
1323 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1324 if (!resultTypesOK) {
1325 if (!allowCovariantReturns &&
1326 m.owner != origin &&
1327 m.owner.isSubClass(other.owner, types)) {
1328 // allow limited interoperability with covariant returns
1329 } else {
1330 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1331 "override.incompatible.ret",
1332 cannotOverride(m, other),
1333 mtres, otres);
1334 return;
1335 }
1336 } else if (overrideWarner.warned) {
1337 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1338 "override.unchecked.ret",
1339 uncheckedOverrides(m, other),
1340 mtres, otres);
1341 }
1342
1343 // Error if overriding method throws an exception not reported
1344 // by overridden method.
1345 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1346 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1347 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1348 if (unhandledErased.nonEmpty()) {
1349 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1350 "override.meth.doesnt.throw",
1351 cannotOverride(m, other),
1352 unhandledUnerased.head);
1353 return;
1354 }
1355 else if (unhandledUnerased.nonEmpty()) {
1356 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1357 "override.unchecked.thrown",
1358 cannotOverride(m, other),
1359 unhandledUnerased.head);
1360 return;
1361 }
1362
1363 // Optional warning if varargs don't agree
1364 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1365 && lint.isEnabled(Lint.LintCategory.OVERRIDES)) {
1366 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1367 ((m.flags() & Flags.VARARGS) != 0)
1368 ? "override.varargs.missing"
1369 : "override.varargs.extra",
1370 varargsOverrides(m, other));
1371 }
1372
1373 // Warn if instance method overrides bridge method (compiler spec ??)
1374 if ((other.flags() & BRIDGE) != 0) {
1375 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1376 uncheckedOverrides(m, other));
1377 }
1378
1379 // Warn if a deprecated method overridden by a non-deprecated one.
1380 if ((other.flags() & DEPRECATED) != 0
1381 && (m.flags() & DEPRECATED) == 0
1382 && m.outermostClass() != other.outermostClass()
1383 && !isDeprecatedOverrideIgnorable(other, origin)) {
1384 warnDeprecated(TreeInfo.diagnosticPositionFor(m, tree), other);
1385 }
1386 }
1387 // where
1388 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1389 // If the method, m, is defined in an interface, then ignore the issue if the method
1390 // is only inherited via a supertype and also implemented in the supertype,
1391 // because in that case, we will rediscover the issue when examining the method
1392 // in the supertype.
1393 // If the method, m, is not defined in an interface, then the only time we need to
1394 // address the issue is when the method is the supertype implemementation: any other
1395 // case, we will have dealt with when examining the supertype classes
1396 ClassSymbol mc = m.enclClass();
1397 Type st = types.supertype(origin.type);
1398 if (st.tag != CLASS)
1399 return true;
1400 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1401
1402 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1403 List<Type> intfs = types.interfaces(origin.type);
1404 return (intfs.contains(mc.type) ? false : (stimpl != null));
1405 }
1406 else
1407 return (stimpl != m);
1408 }
1409
1410
1411 // used to check if there were any unchecked conversions
1412 Warner overrideWarner = new Warner();
1413
1414 /** Check that a class does not inherit two concrete methods
1415 * with the same signature.
1416 * @param pos Position to be used for error reporting.
1417 * @param site The class type to be checked.
1418 */
1419 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1420 Type sup = types.supertype(site);
1421 if (sup.tag != CLASS) return;
1422
1423 for (Type t1 = sup;
1424 t1.tsym.type.isParameterized();
1425 t1 = types.supertype(t1)) {
1426 for (Scope.Entry e1 = t1.tsym.members().elems;
1427 e1 != null;
1428 e1 = e1.sibling) {
1429 Symbol s1 = e1.sym;
1430 if (s1.kind != MTH ||
1431 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1432 !s1.isInheritedIn(site.tsym, types) ||
1433 ((MethodSymbol)s1).implementation(site.tsym,
1434 types,
1435 true) != s1)
1436 continue;
1437 Type st1 = types.memberType(t1, s1);
1438 int s1ArgsLength = st1.getParameterTypes().length();
1439 if (st1 == s1.type) continue;
1440
1441 for (Type t2 = sup;
1442 t2.tag == CLASS;
1443 t2 = types.supertype(t2)) {
1444 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1445 e2.scope != null;
1446 e2 = e2.next()) {
1447 Symbol s2 = e2.sym;
1448 if (s2 == s1 ||
1449 s2.kind != MTH ||
1450 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1451 s2.type.getParameterTypes().length() != s1ArgsLength ||
1452 !s2.isInheritedIn(site.tsym, types) ||
1453 ((MethodSymbol)s2).implementation(site.tsym,
1454 types,
1455 true) != s2)
1456 continue;
1457 Type st2 = types.memberType(t2, s2);
1458 if (types.overrideEquivalent(st1, st2))
1459 log.error(pos, "concrete.inheritance.conflict",
1460 s1, t1, s2, t2, sup);
1461 }
1462 }
1463 }
1464 }
1465 }
1466
1467 /** Check that classes (or interfaces) do not each define an abstract
1468 * method with same name and arguments but incompatible return types.
1469 * @param pos Position to be used for error reporting.
1470 * @param t1 The first argument type.
1471 * @param t2 The second argument type.
1472 */
1473 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1474 Type t1,
1475 Type t2) {
1476 return checkCompatibleAbstracts(pos, t1, t2,
1477 types.makeCompoundType(t1, t2));
1478 }
1479
1480 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1481 Type t1,
1482 Type t2,
1483 Type site) {
1484 Symbol sym = firstIncompatibility(t1, t2, site);
1485 if (sym != null) {
1486 log.error(pos, "types.incompatible.diff.ret",
1487 t1, t2, sym.name +
1488 "(" + types.memberType(t2, sym).getParameterTypes() + ")");
1489 return false;
1490 }
1491 return true;
1492 }
1493
1494 /** Return the first method which is defined with same args
1495 * but different return types in two given interfaces, or null if none
1496 * exists.
1497 * @param t1 The first type.
1498 * @param t2 The second type.
1499 * @param site The most derived type.
1500 * @returns symbol from t2 that conflicts with one in t1.
1501 */
1502 private Symbol firstIncompatibility(Type t1, Type t2, Type site) {
1503 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1504 closure(t1, interfaces1);
1505 Map<TypeSymbol,Type> interfaces2;
1506 if (t1 == t2)
1507 interfaces2 = interfaces1;
1508 else
1509 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1510
1511 for (Type t3 : interfaces1.values()) {
1512 for (Type t4 : interfaces2.values()) {
1513 Symbol s = firstDirectIncompatibility(t3, t4, site);
1514 if (s != null) return s;
1515 }
1516 }
1517 return null;
1518 }
1519
1520 /** Compute all the supertypes of t, indexed by type symbol. */
1521 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1522 if (t.tag != CLASS) return;
1523 if (typeMap.put(t.tsym, t) == null) {
1524 closure(types.supertype(t), typeMap);
1525 for (Type i : types.interfaces(t))
1526 closure(i, typeMap);
1527 }
1528 }
1529
1530 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1531 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1532 if (t.tag != CLASS) return;
1533 if (typesSkip.get(t.tsym) != null) return;
1534 if (typeMap.put(t.tsym, t) == null) {
1535 closure(types.supertype(t), typesSkip, typeMap);
1536 for (Type i : types.interfaces(t))
1537 closure(i, typesSkip, typeMap);
1538 }
1539 }
1540
1541 /** Return the first method in t2 that conflicts with a method from t1. */
1542 private Symbol firstDirectIncompatibility(Type t1, Type t2, Type site) {
1543 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1544 Symbol s1 = e1.sym;
1545 Type st1 = null;
1546 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1547 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1548 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1549 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1550 Symbol s2 = e2.sym;
1551 if (s1 == s2) continue;
1552 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1553 if (st1 == null) st1 = types.memberType(t1, s1);
1554 Type st2 = types.memberType(t2, s2);
1555 if (types.overrideEquivalent(st1, st2)) {
1556 List<Type> tvars1 = st1.getTypeArguments();
1557 List<Type> tvars2 = st2.getTypeArguments();
1558 Type rt1 = st1.getReturnType();
1559 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1560 boolean compat =
1561 types.isSameType(rt1, rt2) ||
1562 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1563 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1564 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1565 checkCommonOverriderIn(s1,s2,site);
1566 if (!compat) return s2;
1567 }
1568 }
1569 }
1570 return null;
1571 }
1572 //WHERE
1573 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1574 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1575 Type st1 = types.memberType(site, s1);
1576 Type st2 = types.memberType(site, s2);
1577 closure(site, supertypes);
1578 for (Type t : supertypes.values()) {
1579 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1580 Symbol s3 = e.sym;
1581 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1582 Type st3 = types.memberType(site,s3);
1583 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1584 if (s3.owner == site.tsym) {
1585 return true;
1586 }
1587 List<Type> tvars1 = st1.getTypeArguments();
1588 List<Type> tvars2 = st2.getTypeArguments();
1589 List<Type> tvars3 = st3.getTypeArguments();
1590 Type rt1 = st1.getReturnType();
1591 Type rt2 = st2.getReturnType();
1592 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1593 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1594 boolean compat =
1595 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1596 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1597 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1598 if (compat)
1599 return true;
1600 }
1601 }
1602 }
1603 return false;
1604 }
1605
1606 /** Check that a given method conforms with any method it overrides.
1607 * @param tree The tree from which positions are extracted
1608 * for errors.
1609 * @param m The overriding method.
1610 */
1611 void checkOverride(JCTree tree, MethodSymbol m) {
1612 ClassSymbol origin = (ClassSymbol)m.owner;
1613 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1614 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1615 log.error(tree.pos(), "enum.no.finalize");
1616 return;
1617 }
1618 for (Type t = types.supertype(origin.type); t.tag == CLASS;
1619 t = types.supertype(t)) {
1620 TypeSymbol c = t.tsym;
1621 Scope.Entry e = c.members().lookup(m.name);
1622 while (e.scope != null) {
1623 if (m.overrides(e.sym, origin, types, false))
1624 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1625 else if (e.sym.kind == MTH &&
1626 e.sym.isInheritedIn(origin, types) &&
1627 (e.sym.flags() & SYNTHETIC) == 0 &&
1628 !m.isConstructor()) {
1629 Type er1 = m.erasure(types);
1630 Type er2 = e.sym.erasure(types);
1631 if (types.isSameTypes(er1.getParameterTypes(),
1632 er2.getParameterTypes())) {
1633 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1634 "name.clash.same.erasure.no.override",
1635 m, m.location(),
1636 e.sym, e.sym.location());
1637 }
1638 }
1639 e = e.next();
1640 }
1641 }
1642 }
1643
1644 /** Check that all abstract members of given class have definitions.
1645 * @param pos Position to be used for error reporting.
1646 * @param c The class.
1647 */
1648 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1649 try {
1650 MethodSymbol undef = firstUndef(c, c);
1651 if (undef != null) {
1652 if ((c.flags() & ENUM) != 0 &&
1653 types.supertype(c.type).tsym == syms.enumSym &&
1654 (c.flags() & FINAL) == 0) {
1655 // add the ABSTRACT flag to an enum
1656 c.flags_field |= ABSTRACT;
1657 } else {
1658 MethodSymbol undef1 =
1659 new MethodSymbol(undef.flags(), undef.name,
1660 types.memberType(c.type, undef), undef.owner);
1661 log.error(pos, "does.not.override.abstract",
1662 c, undef1, undef1.location());
1663 }
1664 }
1665 } catch (CompletionFailure ex) {
1666 completionError(pos, ex);
1667 }
1668 }
1669 //where
1670 /** Return first abstract member of class `c' that is not defined
1671 * in `impl', null if there is none.
1672 */
1673 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1674 MethodSymbol undef = null;
1675 // Do not bother to search in classes that are not abstract,
1676 // since they cannot have abstract members.
1677 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1678 Scope s = c.members();
1679 for (Scope.Entry e = s.elems;
1680 undef == null && e != null;
1681 e = e.sibling) {
1682 if (e.sym.kind == MTH &&
1683 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1684 MethodSymbol absmeth = (MethodSymbol)e.sym;
1685 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1686 if (implmeth == null || implmeth == absmeth)
1687 undef = absmeth;
1688 }
1689 }
1690 if (undef == null) {
1691 Type st = types.supertype(c.type);
1692 if (st.tag == CLASS)
1693 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1694 }
1695 for (List<Type> l = types.interfaces(c.type);
1696 undef == null && l.nonEmpty();
1697 l = l.tail) {
1698 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1699 }
1700 }
1701 return undef;
1702 }
1703
1704 /** Check for cyclic references. Issue an error if the
1705 * symbol of the type referred to has a LOCKED flag set.
1706 *
1707 * @param pos Position to be used for error reporting.
1708 * @param t The type referred to.
1709 */
1710 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1711 checkNonCyclicInternal(pos, t);
1712 }
1713
1714
1715 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1716 checkNonCyclic1(pos, t, List.<TypeVar>nil());
1717 }
1718
1719 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
1720 final TypeVar tv;
1721 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
1722 return;
1723 if (seen.contains(t)) {
1724 tv = (TypeVar)t;
1725 tv.bound = types.createErrorType(t);
1726 log.error(pos, "cyclic.inheritance", t);
1727 } else if (t.tag == TYPEVAR) {
1728 tv = (TypeVar)t;
1729 seen = seen.prepend(tv);
1730 for (Type b : types.getBounds(tv))
1731 checkNonCyclic1(pos, b, seen);
1732 }
1733 }
1734
1735 /** Check for cyclic references. Issue an error if the
1736 * symbol of the type referred to has a LOCKED flag set.
1737 *
1738 * @param pos Position to be used for error reporting.
1739 * @param t The type referred to.
1740 * @returns True if the check completed on all attributed classes
1741 */
1742 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1743 boolean complete = true; // was the check complete?
1744 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1745 Symbol c = t.tsym;
1746 if ((c.flags_field & ACYCLIC) != 0) return true;
1747
1748 if ((c.flags_field & LOCKED) != 0) {
1749 noteCyclic(pos, (ClassSymbol)c);
1750 } else if (!c.type.isErroneous()) {
1751 try {
1752 c.flags_field |= LOCKED;
1753 if (c.type.tag == CLASS) {
1754 ClassType clazz = (ClassType)c.type;
1755 if (clazz.interfaces_field != null)
1756 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1757 complete &= checkNonCyclicInternal(pos, l.head);
1758 if (clazz.supertype_field != null) {
1759 Type st = clazz.supertype_field;
1760 if (st != null && st.tag == CLASS)
1761 complete &= checkNonCyclicInternal(pos, st);
1762 }
1763 if (c.owner.kind == TYP)
1764 complete &= checkNonCyclicInternal(pos, c.owner.type);
1765 }
1766 } finally {
1767 c.flags_field &= ~LOCKED;
1768 }
1769 }
1770 if (complete)
1771 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
1772 if (complete) c.flags_field |= ACYCLIC;
1773 return complete;
1774 }
1775
1776 /** Note that we found an inheritance cycle. */
1777 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
1778 log.error(pos, "cyclic.inheritance", c);
1779 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
1780 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
1781 Type st = types.supertype(c.type);
1782 if (st.tag == CLASS)
1783 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
1784 c.type = types.createErrorType(c, c.type);
1785 c.flags_field |= ACYCLIC;
1786 }
1787
1788 /** Check that all methods which implement some
1789 * method conform to the method they implement.
1790 * @param tree The class definition whose members are checked.
1791 */
1792 void checkImplementations(JCClassDecl tree) {
1793 checkImplementations(tree, tree.sym);
1794 }
1795 //where
1796 /** Check that all methods which implement some
1797 * method in `ic' conform to the method they implement.
1798 */
1799 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
1800 ClassSymbol origin = tree.sym;
1801 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
1802 ClassSymbol lc = (ClassSymbol)l.head.tsym;
1803 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
1804 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
1805 if (e.sym.kind == MTH &&
1806 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
1807 MethodSymbol absmeth = (MethodSymbol)e.sym;
1808 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
1809 if (implmeth != null && implmeth != absmeth &&
1810 (implmeth.owner.flags() & INTERFACE) ==
1811 (origin.flags() & INTERFACE)) {
1812 // don't check if implmeth is in a class, yet
1813 // origin is an interface. This case arises only
1814 // if implmeth is declared in Object. The reason is
1815 // that interfaces really don't inherit from
1816 // Object it's just that the compiler represents
1817 // things that way.
1818 checkOverride(tree, implmeth, absmeth, origin);
1819 }
1820 }
1821 }
1822 }
1823 }
1824 }
1825
1826 /** Check that all abstract methods implemented by a class are
1827 * mutually compatible.
1828 * @param pos Position to be used for error reporting.
1829 * @param c The class whose interfaces are checked.
1830 */
1831 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
1832 List<Type> supertypes = types.interfaces(c);
1833 Type supertype = types.supertype(c);
1834 if (supertype.tag == CLASS &&
1835 (supertype.tsym.flags() & ABSTRACT) != 0)
1836 supertypes = supertypes.prepend(supertype);
1837 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
1838 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
1839 !checkCompatibleAbstracts(pos, l.head, l.head, c))
1840 return;
1841 for (List<Type> m = supertypes; m != l; m = m.tail)
1842 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
1843 return;
1844 }
1845 checkCompatibleConcretes(pos, c);
1846 }
1847
1848 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
1849 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
1850 for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
1851 // VM allows methods and variables with differing types
1852 if (sym.kind == e.sym.kind &&
1853 types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
1854 sym != e.sym &&
1855 (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
1856 (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
1857 syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
1858 return;
1859 }
1860 }
1861 }
1862 }
1863
1864 /** Report a conflict between a user symbol and a synthetic symbol.
1865 */
1866 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
1867 if (!sym.type.isErroneous()) {
1868 if (warnOnSyntheticConflicts) {
1869 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
1870 }
1871 else {
1872 log.error(pos, "synthetic.name.conflict", sym, sym.location());
1873 }
1874 }
1875 }
1876
1877 /** Check that class c does not implement directly or indirectly
1878 * the same parameterized interface with two different argument lists.
1879 * @param pos Position to be used for error reporting.
1880 * @param type The type whose interfaces are checked.
1881 */
1882 void checkClassBounds(DiagnosticPosition pos, Type type) {
1883 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
1884 }
1885 //where
1886 /** Enter all interfaces of type `type' into the hash table `seensofar'
1887 * with their class symbol as key and their type as value. Make
1888 * sure no class is entered with two different types.
1889 */
1890 void checkClassBounds(DiagnosticPosition pos,
1891 Map<TypeSymbol,Type> seensofar,
1892 Type type) {
1893 if (type.isErroneous()) return;
1894 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
1895 Type it = l.head;
1896 Type oldit = seensofar.put(it.tsym, it);
1897 if (oldit != null) {
1898 List<Type> oldparams = oldit.allparams();
1899 List<Type> newparams = it.allparams();
1900 if (!types.containsTypeEquivalent(oldparams, newparams))
1901 log.error(pos, "cant.inherit.diff.arg",
1902 it.tsym, Type.toString(oldparams),
1903 Type.toString(newparams));
1904 }
1905 checkClassBounds(pos, seensofar, it);
1906 }
1907 Type st = types.supertype(type);
1908 if (st != null) checkClassBounds(pos, seensofar, st);
1909 }
1910
1911 /** Enter interface into into set.
1912 * If it existed already, issue a "repeated interface" error.
1913 */
1914 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
1915 if (its.contains(it))
1916 log.error(pos, "repeated.interface");
1917 else {
1918 its.add(it);
1919 }
1920 }
1921
1922 /* *************************************************************************
1923 * Check annotations
1924 **************************************************************************/
1925
1926 /** Annotation types are restricted to primitives, String, an
1927 * enum, an annotation, Class, Class<?>, Class<? extends
1928 * Anything>, arrays of the preceding.
1929 */
1930 void validateAnnotationType(JCTree restype) {
1931 // restype may be null if an error occurred, so don't bother validating it
1932 if (restype != null) {
1933 validateAnnotationType(restype.pos(), restype.type);
1934 }
1935 }
1936
1937 void validateAnnotationType(DiagnosticPosition pos, Type type) {
1938 if (type.isPrimitive()) return;
1939 if (types.isSameType(type, syms.stringType)) return;
1940 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
1941 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
1942 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
1943 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
1944 validateAnnotationType(pos, types.elemtype(type));
1945 return;
1946 }
1947 log.error(pos, "invalid.annotation.member.type");
1948 }
1949
1950 /**
1951 * "It is also a compile-time error if any method declared in an
1952 * annotation type has a signature that is override-equivalent to
1953 * that of any public or protected method declared in class Object
1954 * or in the interface annotation.Annotation."
1955 *
1956 * @jls3 9.6 Annotation Types
1957 */
1958 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
1959 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
1960 Scope s = sup.tsym.members();
1961 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
1962 if (e.sym.kind == MTH &&
1963 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
1964 types.overrideEquivalent(m.type, e.sym.type))
1965 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
1966 }
1967 }
1968 }
1969
1970 /** Check the annotations of a symbol.
1971 */
1972 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
1973 if (skipAnnotations) return;
1974 for (JCAnnotation a : annotations)
1975 validateAnnotation(a, s);
1976 }
1977
1978 /** Check the type annotations
1979 */
1980 public void validateTypeAnnotations(List<JCTypeAnnotation> annotations, boolean isTypeParameter) {
1981 if (skipAnnotations) return;
1982 for (JCTypeAnnotation a : annotations)
1983 validateTypeAnnotation(a, isTypeParameter);
1984 }
1985
1986 /** Check an annotation of a symbol.
1987 */
1988 public void validateAnnotation(JCAnnotation a, Symbol s) {
1989 validateAnnotation(a);
1990
1991 if (!annotationApplicable(a, s))
1992 log.error(a.pos(), "annotation.type.not.applicable");
1993
1994 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
1995 if (!isOverrider(s))
1996 log.error(a.pos(), "method.does.not.override.superclass");
1997 }
1998 }
1999
2000 public void validateTypeAnnotation(JCTypeAnnotation a, boolean isTypeParameter) {
2001 if (a.type == null)
2002 throw new AssertionError("annotation tree hasn't been attributed yet: " + a);
2003 validateAnnotation(a);
2004
2005 if (!isTypeAnnotation(a, isTypeParameter))
2006 log.error(a.pos(), "annotation.type.not.applicable");
2007 }
2008
2009 /** Is s a method symbol that overrides a method in a superclass? */
2010 boolean isOverrider(Symbol s) {
2011 if (s.kind != MTH || s.isStatic())
2012 return false;
2013 MethodSymbol m = (MethodSymbol)s;
2014 TypeSymbol owner = (TypeSymbol)m.owner;
2015 for (Type sup : types.closure(owner.type)) {
2016 if (sup == owner.type)
2017 continue; // skip "this"
2018 Scope scope = sup.tsym.members();
2019 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
2020 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
2021 return true;
2022 }
2023 }
2024 return false;
2025 }
2026
2027 /** Is the annotation applicable to type annotations */
2028 boolean isTypeAnnotation(JCTypeAnnotation a, boolean isTypeParameter) {
2029 Attribute.Compound atTarget =
2030 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
2031 if (atTarget == null) return true;
2032 Attribute atValue = atTarget.member(names.value);
2033 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
2034 Attribute.Array arr = (Attribute.Array) atValue;
2035 for (Attribute app : arr.values) {
2036 if (!(app instanceof Attribute.Enum)) return true; // recovery
2037 Attribute.Enum e = (Attribute.Enum) app;
2038 if (!isTypeParameter && e.value.name == names.TYPE_USE)
2039 return true;
2040 else if (isTypeParameter && e.value.name == names.TYPE_PARAMETER)
2041 return true;
2042 }
2043 return false;
2044 }
2045
2046 /** Is the annotation applicable to the symbol? */
2047 boolean annotationApplicable(JCAnnotation a, Symbol s) {
2048 Attribute.Compound atTarget =
2049 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
2050 if (atTarget == null) return true;
2051 Attribute atValue = atTarget.member(names.value);
2052 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
2053 Attribute.Array arr = (Attribute.Array) atValue;
2054 for (Attribute app : arr.values) {
2055 if (!(app instanceof Attribute.Enum)) return true; // recovery
2056 Attribute.Enum e = (Attribute.Enum) app;
2057 if (e.value.name == names.TYPE)
2058 { if (s.kind == TYP) return true; }
2059 else if (e.value.name == names.FIELD)
2060 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
2061 else if (e.value.name == names.METHOD)
2062 { if (s.kind == MTH && !s.isConstructor()) return true; }
2063 else if (e.value.name == names.PARAMETER)
2064 { if (s.kind == VAR &&
2065 s.owner.kind == MTH &&
2066 (s.flags() & PARAMETER) != 0)
2067 return true;
2068 }
2069 else if (e.value.name == names.CONSTRUCTOR)
2070 { if (s.kind == MTH && s.isConstructor()) return true; }
2071 else if (e.value.name == names.LOCAL_VARIABLE)
2072 { if (s.kind == VAR && s.owner.kind == MTH &&
2073 (s.flags() & PARAMETER) == 0)
2074 return true;
2075 }
2076 else if (e.value.name == names.ANNOTATION_TYPE)
2077 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
2078 return true;
2079 }
2080 else if (e.value.name == names.PACKAGE)
2081 { if (s.kind == PCK) return true; }
2082 else if (e.value.name == names.TYPE_USE)
2083 { if (s.kind == TYP ||
2084 s.kind == VAR ||
2085 (s.kind == MTH && !s.isConstructor() &&
2086 s.type.getReturnType().tag != VOID))
2087 return true;
2088 }
2089 else
2090 return true; // recovery
2091 }
2092 return false;
2093 }
2094
2095 /** Check an annotation value.
2096 */
2097 public void validateAnnotation(JCAnnotation a) {
2098 if (a.type.isErroneous()) return;
2099
2100 // collect an inventory of the members
2101 Set<MethodSymbol> members = new HashSet<MethodSymbol>();
2102 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
2103 e != null;
2104 e = e.sibling)
2105 if (e.sym.kind == MTH)
2106 members.add((MethodSymbol) e.sym);
2107
2108 // count them off as they're annotated
2109 for (JCTree arg : a.args) {
2110 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
2111 JCAssign assign = (JCAssign) arg;
2112 Symbol m = TreeInfo.symbol(assign.lhs);
2113 if (m == null || m.type.isErroneous()) continue;
2114 if (!members.remove(m))
2115 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
2116 m.name, a.type);
2117 if (assign.rhs.getTag() == ANNOTATION)
2118 validateAnnotation((JCAnnotation)assign.rhs);
2119 }
2120
2121 // all the remaining ones better have default values
2122 for (MethodSymbol m : members)
2123 if (m.defaultValue == null && !m.type.isErroneous())
2124 log.error(a.pos(), "annotation.missing.default.value",
2125 a.type, m.name);
2126
2127 // special case: java.lang.annotation.Target must not have
2128 // repeated values in its value member
2129 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
2130 a.args.tail == null)
2131 return;
2132
2133 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
2134 JCAssign assign = (JCAssign) a.args.head;
2135 Symbol m = TreeInfo.symbol(assign.lhs);
2136 if (m.name != names.value) return;
2137 JCTree rhs = assign.rhs;
2138 if (rhs.getTag() != JCTree.NEWARRAY) return;
2139 JCNewArray na = (JCNewArray) rhs;
2140 Set<Symbol> targets = new HashSet<Symbol>();
2141 for (JCTree elem : na.elems) {
2142 if (!targets.add(TreeInfo.symbol(elem))) {
2143 log.error(elem.pos(), "repeated.annotation.target");
2144 }
2145 }
2146 }
2147
2148 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
2149 if (allowAnnotations &&
2150 lint.isEnabled(Lint.LintCategory.DEP_ANN) &&
2151 (s.flags() & DEPRECATED) != 0 &&
2152 !syms.deprecatedType.isErroneous() &&
2153 s.attribute(syms.deprecatedType.tsym) == null) {
2154 log.warning(pos, "missing.deprecated.annotation");
2155 }
2156 }
2157
2158 /* *************************************************************************
2159 * Check for recursive annotation elements.
2160 **************************************************************************/
2161
2162 /** Check for cycles in the graph of annotation elements.
2163 */
2164 void checkNonCyclicElements(JCClassDecl tree) {
2165 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
2166 assert (tree.sym.flags_field & LOCKED) == 0;
2167 try {
2168 tree.sym.flags_field |= LOCKED;
2169 for (JCTree def : tree.defs) {
2170 if (def.getTag() != JCTree.METHODDEF) continue;
2171 JCMethodDecl meth = (JCMethodDecl)def;
2172 checkAnnotationResType(meth.pos(), meth.restype.type);
2173 }
2174 } finally {
2175 tree.sym.flags_field &= ~LOCKED;
2176 tree.sym.flags_field |= ACYCLIC_ANN;
2177 }
2178 }
2179
2180 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
2181 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
2182 return;
2183 if ((tsym.flags_field & LOCKED) != 0) {
2184 log.error(pos, "cyclic.annotation.element");
2185 return;
2186 }
2187 try {
2188 tsym.flags_field |= LOCKED;
2189 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
2190 Symbol s = e.sym;
2191 if (s.kind != Kinds.MTH)
2192 continue;
2193 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
2194 }
2195 } finally {
2196 tsym.flags_field &= ~LOCKED;
2197 tsym.flags_field |= ACYCLIC_ANN;
2198 }
2199 }
2200
2201 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
2202 switch (type.tag) {
2203 case TypeTags.CLASS:
2204 if ((type.tsym.flags() & ANNOTATION) != 0)
2205 checkNonCyclicElementsInternal(pos, type.tsym);
2206 break;
2207 case TypeTags.ARRAY:
2208 checkAnnotationResType(pos, types.elemtype(type));
2209 break;
2210 default:
2211 break; // int etc
2212 }
2213 }
2214
2215 /* *************************************************************************
2216 * Check for cycles in the constructor call graph.
2217 **************************************************************************/
2218
2219 /** Check for cycles in the graph of constructors calling other
2220 * constructors.
2221 */
2222 void checkCyclicConstructors(JCClassDecl tree) {
2223 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
2224
2225 // enter each constructor this-call into the map
2226 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2227 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
2228 if (app == null) continue;
2229 JCMethodDecl meth = (JCMethodDecl) l.head;
2230 if (TreeInfo.name(app.meth) == names._this) {
2231 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
2232 } else {
2233 meth.sym.flags_field |= ACYCLIC;
2234 }
2235 }
2236
2237 // Check for cycles in the map
2238 Symbol[] ctors = new Symbol[0];
2239 ctors = callMap.keySet().toArray(ctors);
2240 for (Symbol caller : ctors) {
2241 checkCyclicConstructor(tree, caller, callMap);
2242 }
2243 }
2244
2245 /** Look in the map to see if the given constructor is part of a
2246 * call cycle.
2247 */
2248 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
2249 Map<Symbol,Symbol> callMap) {
2250 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
2251 if ((ctor.flags_field & LOCKED) != 0) {
2252 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
2253 "recursive.ctor.invocation");
2254 } else {
2255 ctor.flags_field |= LOCKED;
2256 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2257 ctor.flags_field &= ~LOCKED;
2258 }
2259 ctor.flags_field |= ACYCLIC;
2260 }
2261 }
2262
2263 /* *************************************************************************
2264 * Miscellaneous
2265 **************************************************************************/
2266
2267 /**
2268 * Return the opcode of the operator but emit an error if it is an
2269 * error.
2270 * @param pos position for error reporting.
2271 * @param operator an operator
2272 * @param tag a tree tag
2273 * @param left type of left hand side
2274 * @param right type of right hand side
2275 */
2276 int checkOperator(DiagnosticPosition pos,
2277 OperatorSymbol operator,
2278 int tag,
2279 Type left,
2280 Type right) {
2281 if (operator.opcode == ByteCodes.error) {
2282 log.error(pos,
2283 "operator.cant.be.applied",
2284 treeinfo.operatorName(tag),
2285 List.of(left, right));
2286 }
2287 return operator.opcode;
2288 }
2289
2290
2291 /**
2292 * Check for division by integer constant zero
2293 * @param pos Position for error reporting.
2294 * @param operator The operator for the expression
2295 * @param operand The right hand operand for the expression
2296 */
2297 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
2298 if (operand.constValue() != null
2299 && lint.isEnabled(Lint.LintCategory.DIVZERO)
2300 && operand.tag <= LONG
2301 && ((Number) (operand.constValue())).longValue() == 0) {
2302 int opc = ((OperatorSymbol)operator).opcode;
2303 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
2304 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
2305 log.warning(pos, "div.zero");
2306 }
2307 }
2308 }
2309
2310 /**
2311 * Check for empty statements after if
2312 */
2313 void checkEmptyIf(JCIf tree) {
2314 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(Lint.LintCategory.EMPTY))
2315 log.warning(tree.thenpart.pos(), "empty.if");
2316 }
2317
2318 /** Check that symbol is unique in given scope.
2319 * @param pos Position for error reporting.
2320 * @param sym The symbol.
2321 * @param s The scope.
2322 */
2323 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2324 if (sym.type.isErroneous())
2325 return true;
2326 if (sym.owner.name == names.any) return false;
2327 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2328 if (sym != e.sym &&
2329 sym.kind == e.sym.kind &&
2330 sym.name != names.error &&
2331 (sym.kind != MTH || types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
2332 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS))
2333 varargsDuplicateError(pos, sym, e.sym);
2334 else if (sym.kind == MTH && !types.overrideEquivalent(sym.type, e.sym.type))
2335 duplicateErasureError(pos, sym, e.sym);
2336 else
2337 duplicateError(pos, e.sym);
2338 return false;
2339 }
2340 }
2341 return true;
2342 }
2343 //where
2344 /** Report duplicate declaration error.
2345 */
2346 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
2347 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
2348 log.error(pos, "name.clash.same.erasure", sym1, sym2);
2349 }
2350 }
2351
2352 /** Check that single-type import is not already imported or top-level defined,
2353 * but make an exception for two single-type imports which denote the same type.
2354 * @param pos Position for error reporting.
2355 * @param sym The symbol.
2356 * @param s The scope
2357 */
2358 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2359 return checkUniqueImport(pos, sym, s, false);
2360 }
2361
2362 /** Check that static single-type import is not already imported or top-level defined,
2363 * but make an exception for two single-type imports which denote the same type.
2364 * @param pos Position for error reporting.
2365 * @param sym The symbol.
2366 * @param s The scope
2367 * @param staticImport Whether or not this was a static import
2368 */
2369 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2370 return checkUniqueImport(pos, sym, s, true);
2371 }
2372
2373 /** Check that single-type import is not already imported or top-level defined,
2374 * but make an exception for two single-type imports which denote the same type.
2375 * @param pos Position for error reporting.
2376 * @param sym The symbol.
2377 * @param s The scope.
2378 * @param staticImport Whether or not this was a static import
2379 */
2380 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2381 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2382 // is encountered class entered via a class declaration?
2383 boolean isClassDecl = e.scope == s;
2384 if ((isClassDecl || sym != e.sym) &&
2385 sym.kind == e.sym.kind &&
2386 sym.name != names.error) {
2387 if (!e.sym.type.isErroneous()) {
2388 String what = e.sym.toString();
2389 if (!isClassDecl) {
2390 if (staticImport)
2391 log.error(pos, "already.defined.static.single.import", what);
2392 else
2393 log.error(pos, "already.defined.single.import", what);
2394 }
2395 else if (sym != e.sym)
2396 log.error(pos, "already.defined.this.unit", what);
2397 }
2398 return false;
2399 }
2400 }
2401 return true;
2402 }
2403
2404 /** Check that a qualified name is in canonical form (for import decls).
2405 */
2406 public void checkCanonical(JCTree tree) {
2407 if (!isCanonical(tree))
2408 log.error(tree.pos(), "import.requires.canonical",
2409 TreeInfo.symbol(tree));
2410 }
2411 // where
2412 private boolean isCanonical(JCTree tree) {
2413 while (tree.getTag() == JCTree.SELECT) {
2414 JCFieldAccess s = (JCFieldAccess) tree;
2415 if (s.sym.owner != TreeInfo.symbol(s.selected))
2416 return false;
2417 tree = s.selected;
2418 }
2419 return true;
2420 }
2421
2422 private class ConversionWarner extends Warner {
2423 final String key;
2424 final Type found;
2425 final Type expected;
2426 public ConversionWarner(DiagnosticPosition pos, String key, Type found, Type expected) {
2427 super(pos);
2428 this.key = key;
2429 this.found = found;
2430 this.expected = expected;
2431 }
2432
2433 @Override
2434 public void warnUnchecked() {
2435 boolean warned = this.warned;
2436 super.warnUnchecked();
2437 if (warned) return; // suppress redundant diagnostics
2438 Object problem = diags.fragment(key);
2439 Check.this.warnUnchecked(pos(), "prob.found.req", problem, found, expected);
2440 }
2441 }
2442
2443 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2444 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2445 }
2446
2447 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2448 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2449 }
2450 }