Mercurial > jdk8-mips64-public > langtools / file revision
src/share/classes/com/sun/tools/javac/comp/Check.java@36df13bde238
src/share/classes/com/sun/tools/javac/comp/Check.java
Thu, 24 Jul 2008 11:12:41 +0100
- author
- mcimadamore
- date
- Thu, 24 Jul 2008 11:12:41 +0100
- changeset 79
- 36df13bde238
- parent 78
- 77dba8b57346
- child 80
- 5c9cdeb740f2
- permissions
- -rw-r--r--
6594284: NPE thrown when calling a method on an intersection type
Summary: javac should report an error when the capture of an actual type parameter does not exist
Reviewed-by: jjg
1 /*
2 * Copyright 1999-2008 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
26 package com.sun.tools.javac.comp;
28 import java.util.*;
29 import java.util.Set;
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;
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.*;
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.*;
48 /** Type checking helper class for the attribution phase.
49 *
50 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
51 * 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>();
59 private final Name.Table names;
60 private final Log log;
61 private final Symtab syms;
62 private final Infer infer;
63 private final Target target;
64 private final Source source;
65 private final Types types;
66 private final boolean skipAnnotations;
67 private final TreeInfo treeinfo;
69 // The set of lint options currently in effect. It is initialized
70 // from the context, and then is set/reset as needed by Attr as it
71 // visits all the various parts of the trees during attribution.
72 private Lint lint;
74 public static Check instance(Context context) {
75 Check instance = context.get(checkKey);
76 if (instance == null)
77 instance = new Check(context);
78 return instance;
79 }
81 protected Check(Context context) {
82 context.put(checkKey, this);
84 names = Name.Table.instance(context);
85 log = Log.instance(context);
86 syms = Symtab.instance(context);
87 infer = Infer.instance(context);
88 this.types = Types.instance(context);
89 Options options = Options.instance(context);
90 target = Target.instance(context);
91 source = Source.instance(context);
92 lint = Lint.instance(context);
93 treeinfo = TreeInfo.instance(context);
95 Source source = Source.instance(context);
96 allowGenerics = source.allowGenerics();
97 allowAnnotations = source.allowAnnotations();
98 complexInference = options.get("-complexinference") != null;
99 skipAnnotations = options.get("skipAnnotations") != null;
101 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
102 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
103 boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
105 deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
106 enforceMandatoryWarnings, "deprecated");
107 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
108 enforceMandatoryWarnings, "unchecked");
109 }
111 /** Switch: generics enabled?
112 */
113 boolean allowGenerics;
115 /** Switch: annotations enabled?
116 */
117 boolean allowAnnotations;
119 /** Switch: -complexinference option set?
120 */
121 boolean complexInference;
123 /** A table mapping flat names of all compiled classes in this run to their
124 * symbols; maintained from outside.
125 */
126 public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
128 /** A handler for messages about deprecated usage.
129 */
130 private MandatoryWarningHandler deprecationHandler;
132 /** A handler for messages about unchecked or unsafe usage.
133 */
134 private MandatoryWarningHandler uncheckedHandler;
137 /* *************************************************************************
138 * Errors and Warnings
139 **************************************************************************/
141 Lint setLint(Lint newLint) {
142 Lint prev = lint;
143 lint = newLint;
144 return prev;
145 }
147 /** Warn about deprecated symbol.
148 * @param pos Position to be used for error reporting.
149 * @param sym The deprecated symbol.
150 */
151 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
152 if (!lint.isSuppressed(LintCategory.DEPRECATION))
153 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
154 }
156 /** Warn about unchecked operation.
157 * @param pos Position to be used for error reporting.
158 * @param msg A string describing the problem.
159 */
160 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
161 if (!lint.isSuppressed(LintCategory.UNCHECKED))
162 uncheckedHandler.report(pos, msg, args);
163 }
165 /**
166 * Report any deferred diagnostics.
167 */
168 public void reportDeferredDiagnostics() {
169 deprecationHandler.reportDeferredDiagnostic();
170 uncheckedHandler.reportDeferredDiagnostic();
171 }
174 /** Report a failure to complete a class.
175 * @param pos Position to be used for error reporting.
176 * @param ex The failure to report.
177 */
178 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
179 log.error(pos, "cant.access", ex.sym, ex.getDetailValue());
180 if (ex instanceof ClassReader.BadClassFile) throw new Abort();
181 else return syms.errType;
182 }
184 /** Report a type error.
185 * @param pos Position to be used for error reporting.
186 * @param problem A string describing the error.
187 * @param found The type that was found.
188 * @param req The type that was required.
189 */
190 Type typeError(DiagnosticPosition pos, Object problem, Type found, Type req) {
191 log.error(pos, "prob.found.req",
192 problem, found, req);
193 return syms.errType;
194 }
196 Type typeError(DiagnosticPosition pos, String problem, Type found, Type req, Object explanation) {
197 log.error(pos, "prob.found.req.1", problem, found, req, explanation);
198 return syms.errType;
199 }
201 /** Report an error that wrong type tag was found.
202 * @param pos Position to be used for error reporting.
203 * @param required An internationalized string describing the type tag
204 * required.
205 * @param found The type that was found.
206 */
207 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
208 log.error(pos, "type.found.req", found, required);
209 return syms.errType;
210 }
212 /** Report an error that symbol cannot be referenced before super
213 * has been called.
214 * @param pos Position to be used for error reporting.
215 * @param sym The referenced symbol.
216 */
217 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
218 log.error(pos, "cant.ref.before.ctor.called", sym);
219 }
221 /** Report duplicate declaration error.
222 */
223 void duplicateError(DiagnosticPosition pos, Symbol sym) {
224 if (!sym.type.isErroneous()) {
225 log.error(pos, "already.defined", sym, sym.location());
226 }
227 }
229 /** Report array/varargs duplicate declaration
230 */
231 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
232 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
233 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
234 }
235 }
237 /* ************************************************************************
238 * duplicate declaration checking
239 *************************************************************************/
241 /** Check that variable does not hide variable with same name in
242 * immediately enclosing local scope.
243 * @param pos Position for error reporting.
244 * @param v The symbol.
245 * @param s The scope.
246 */
247 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
248 if (s.next != null) {
249 for (Scope.Entry e = s.next.lookup(v.name);
250 e.scope != null && e.sym.owner == v.owner;
251 e = e.next()) {
252 if (e.sym.kind == VAR &&
253 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
254 v.name != names.error) {
255 duplicateError(pos, e.sym);
256 return;
257 }
258 }
259 }
260 }
262 /** Check that a class or interface does not hide a class or
263 * interface with same name in immediately enclosing local scope.
264 * @param pos Position for error reporting.
265 * @param c The symbol.
266 * @param s The scope.
267 */
268 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
269 if (s.next != null) {
270 for (Scope.Entry e = s.next.lookup(c.name);
271 e.scope != null && e.sym.owner == c.owner;
272 e = e.next()) {
273 if (e.sym.kind == TYP &&
274 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
275 c.name != names.error) {
276 duplicateError(pos, e.sym);
277 return;
278 }
279 }
280 }
281 }
283 /** Check that class does not have the same name as one of
284 * its enclosing classes, or as a class defined in its enclosing scope.
285 * return true if class is unique in its enclosing scope.
286 * @param pos Position for error reporting.
287 * @param name The class name.
288 * @param s The enclosing scope.
289 */
290 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
291 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
292 if (e.sym.kind == TYP && e.sym.name != names.error) {
293 duplicateError(pos, e.sym);
294 return false;
295 }
296 }
297 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
298 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
299 duplicateError(pos, sym);
300 return true;
301 }
302 }
303 return true;
304 }
306 /* *************************************************************************
307 * Class name generation
308 **************************************************************************/
310 /** Return name of local class.
311 * This is of the form <enclClass> $ n <classname>
312 * where
313 * enclClass is the flat name of the enclosing class,
314 * classname is the simple name of the local class
315 */
316 Name localClassName(ClassSymbol c) {
317 for (int i=1; ; i++) {
318 Name flatname = names.
319 fromString("" + c.owner.enclClass().flatname +
320 target.syntheticNameChar() + i +
321 c.name);
322 if (compiled.get(flatname) == null) return flatname;
323 }
324 }
326 /* *************************************************************************
327 * Type Checking
328 **************************************************************************/
330 /** Check that a given type is assignable to a given proto-type.
331 * If it is, return the type, otherwise return errType.
332 * @param pos Position to be used for error reporting.
333 * @param found The type that was found.
334 * @param req The type that was required.
335 */
336 Type checkType(DiagnosticPosition pos, Type found, Type req) {
337 if (req.tag == ERROR)
338 return req;
339 if (found.tag == FORALL)
340 return instantiatePoly(pos, (ForAll)found, req, convertWarner(pos, found, req));
341 if (req.tag == NONE)
342 return found;
343 if (types.isAssignable(found, req, convertWarner(pos, found, req)))
344 return found;
345 if (found.tag <= DOUBLE && req.tag <= DOUBLE)
346 return typeError(pos, JCDiagnostic.fragment("possible.loss.of.precision"), found, req);
347 if (found.isSuperBound()) {
348 log.error(pos, "assignment.from.super-bound", found);
349 return syms.errType;
350 }
351 if (req.isExtendsBound()) {
352 log.error(pos, "assignment.to.extends-bound", req);
353 return syms.errType;
354 }
355 return typeError(pos, JCDiagnostic.fragment("incompatible.types"), found, req);
356 }
358 /** Instantiate polymorphic type to some prototype, unless
359 * prototype is `anyPoly' in which case polymorphic type
360 * is returned unchanged.
361 */
362 Type instantiatePoly(DiagnosticPosition pos, ForAll t, Type pt, Warner warn) {
363 if (pt == Infer.anyPoly && complexInference) {
364 return t;
365 } else if (pt == Infer.anyPoly || pt.tag == NONE) {
366 Type newpt = t.qtype.tag <= VOID ? t.qtype : syms.objectType;
367 return instantiatePoly(pos, t, newpt, warn);
368 } else if (pt.tag == ERROR) {
369 return pt;
370 } else {
371 try {
372 return infer.instantiateExpr(t, pt, warn);
373 } catch (Infer.NoInstanceException ex) {
374 if (ex.isAmbiguous) {
375 JCDiagnostic d = ex.getDiagnostic();
376 log.error(pos,
377 "undetermined.type" + (d!=null ? ".1" : ""),
378 t, d);
379 return syms.errType;
380 } else {
381 JCDiagnostic d = ex.getDiagnostic();
382 return typeError(pos,
383 JCDiagnostic.fragment("incompatible.types" + (d!=null ? ".1" : ""), d),
384 t, pt);
385 }
386 }
387 }
388 }
390 /** Check that a given type can be cast to a given target type.
391 * Return the result of the cast.
392 * @param pos Position to be used for error reporting.
393 * @param found The type that is being cast.
394 * @param req The target type of the cast.
395 */
396 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
397 if (found.tag == FORALL) {
398 instantiatePoly(pos, (ForAll) found, req, castWarner(pos, found, req));
399 return req;
400 } else if (types.isCastable(found, req, castWarner(pos, found, req))) {
401 return req;
402 } else {
403 return typeError(pos,
404 JCDiagnostic.fragment("inconvertible.types"),
405 found, req);
406 }
407 }
408 //where
409 /** Is type a type variable, or a (possibly multi-dimensional) array of
410 * type variables?
411 */
412 boolean isTypeVar(Type t) {
413 return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
414 }
416 /** Check that a type is within some bounds.
417 *
418 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
419 * type argument.
420 * @param pos Position to be used for error reporting.
421 * @param a The type that should be bounded by bs.
422 * @param bs The bound.
423 */
424 private void checkExtends(DiagnosticPosition pos, Type a, TypeVar bs) {
425 if (a.tag == TYPEVAR && ((TypeVar)a).isCaptured()) {
426 CapturedType ct = (CapturedType)a;
427 boolean ok;
428 if (ct.bound.isErroneous()) {//capture doesn't exist
429 ok = false;
430 }
431 else {
432 switch (ct.wildcard.kind) {
433 case EXTENDS:
434 ok = types.isCastable(bs.getUpperBound(),
435 types.upperBound(a),
436 Warner.noWarnings);
437 break;
438 case SUPER:
439 ok = !types.notSoftSubtype(types.lowerBound(a),
440 bs.getUpperBound());
441 break;
442 case UNBOUND:
443 ok = true;
444 break;
445 default:
446 throw new AssertionError("Invalid bound kind");
447 }
448 }
449 if (!ok)
450 log.error(pos, "not.within.bounds", a);
451 }
452 else {
453 a = types.upperBound(a);
454 for (List<Type> l = types.getBounds(bs); l.nonEmpty(); l = l.tail) {
455 if (!types.isSubtype(a, l.head)) {
456 log.error(pos, "not.within.bounds", a);
457 return;
458 }
459 }
460 }
461 }
463 /** Check that type is different from 'void'.
464 * @param pos Position to be used for error reporting.
465 * @param t The type to be checked.
466 */
467 Type checkNonVoid(DiagnosticPosition pos, Type t) {
468 if (t.tag == VOID) {
469 log.error(pos, "void.not.allowed.here");
470 return syms.errType;
471 } else {
472 return t;
473 }
474 }
476 /** Check that type is a class or interface type.
477 * @param pos Position to be used for error reporting.
478 * @param t The type to be checked.
479 */
480 Type checkClassType(DiagnosticPosition pos, Type t) {
481 if (t.tag != CLASS && t.tag != ERROR)
482 return typeTagError(pos,
483 JCDiagnostic.fragment("type.req.class"),
484 (t.tag == TYPEVAR)
485 ? JCDiagnostic.fragment("type.parameter", t)
486 : t);
487 else
488 return t;
489 }
491 /** Check that type is a class or interface type.
492 * @param pos Position to be used for error reporting.
493 * @param t The type to be checked.
494 * @param noBounds True if type bounds are illegal here.
495 */
496 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
497 t = checkClassType(pos, t);
498 if (noBounds && t.isParameterized()) {
499 List<Type> args = t.getTypeArguments();
500 while (args.nonEmpty()) {
501 if (args.head.tag == WILDCARD)
502 return typeTagError(pos,
503 log.getLocalizedString("type.req.exact"),
504 args.head);
505 args = args.tail;
506 }
507 }
508 return t;
509 }
511 /** Check that type is a reifiable class, interface or array type.
512 * @param pos Position to be used for error reporting.
513 * @param t The type to be checked.
514 */
515 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
516 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
517 return typeTagError(pos,
518 JCDiagnostic.fragment("type.req.class.array"),
519 t);
520 } else if (!types.isReifiable(t)) {
521 log.error(pos, "illegal.generic.type.for.instof");
522 return syms.errType;
523 } else {
524 return t;
525 }
526 }
528 /** Check that type is a reference type, i.e. a class, interface or array type
529 * or a type variable.
530 * @param pos Position to be used for error reporting.
531 * @param t The type to be checked.
532 */
533 Type checkRefType(DiagnosticPosition pos, Type t) {
534 switch (t.tag) {
535 case CLASS:
536 case ARRAY:
537 case TYPEVAR:
538 case WILDCARD:
539 case ERROR:
540 return t;
541 default:
542 return typeTagError(pos,
543 JCDiagnostic.fragment("type.req.ref"),
544 t);
545 }
546 }
548 /** Check that type is a null or reference type.
549 * @param pos Position to be used for error reporting.
550 * @param t The type to be checked.
551 */
552 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
553 switch (t.tag) {
554 case CLASS:
555 case ARRAY:
556 case TYPEVAR:
557 case WILDCARD:
558 case BOT:
559 case ERROR:
560 return t;
561 default:
562 return typeTagError(pos,
563 JCDiagnostic.fragment("type.req.ref"),
564 t);
565 }
566 }
568 /** Check that flag set does not contain elements of two conflicting sets. s
569 * Return true if it doesn't.
570 * @param pos Position to be used for error reporting.
571 * @param flags The set of flags to be checked.
572 * @param set1 Conflicting flags set #1.
573 * @param set2 Conflicting flags set #2.
574 */
575 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
576 if ((flags & set1) != 0 && (flags & set2) != 0) {
577 log.error(pos,
578 "illegal.combination.of.modifiers",
579 TreeInfo.flagNames(TreeInfo.firstFlag(flags & set1)),
580 TreeInfo.flagNames(TreeInfo.firstFlag(flags & set2)));
581 return false;
582 } else
583 return true;
584 }
586 /** Check that given modifiers are legal for given symbol and
587 * return modifiers together with any implicit modififiers for that symbol.
588 * Warning: we can't use flags() here since this method
589 * is called during class enter, when flags() would cause a premature
590 * completion.
591 * @param pos Position to be used for error reporting.
592 * @param flags The set of modifiers given in a definition.
593 * @param sym The defined symbol.
594 */
595 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
596 long mask;
597 long implicit = 0;
598 switch (sym.kind) {
599 case VAR:
600 if (sym.owner.kind != TYP)
601 mask = LocalVarFlags;
602 else if ((sym.owner.flags_field & INTERFACE) != 0)
603 mask = implicit = InterfaceVarFlags;
604 else
605 mask = VarFlags;
606 break;
607 case MTH:
608 if (sym.name == names.init) {
609 if ((sym.owner.flags_field & ENUM) != 0) {
610 // enum constructors cannot be declared public or
611 // protected and must be implicitly or explicitly
612 // private
613 implicit = PRIVATE;
614 mask = PRIVATE;
615 } else
616 mask = ConstructorFlags;
617 } else if ((sym.owner.flags_field & INTERFACE) != 0)
618 mask = implicit = InterfaceMethodFlags;
619 else {
620 mask = MethodFlags;
621 }
622 // Imply STRICTFP if owner has STRICTFP set.
623 if (((flags|implicit) & Flags.ABSTRACT) == 0)
624 implicit |= sym.owner.flags_field & STRICTFP;
625 break;
626 case TYP:
627 if (sym.isLocal()) {
628 mask = LocalClassFlags;
629 if (sym.name.len == 0) { // Anonymous class
630 // Anonymous classes in static methods are themselves static;
631 // that's why we admit STATIC here.
632 mask |= STATIC;
633 // JLS: Anonymous classes are final.
634 implicit |= FINAL;
635 }
636 if ((sym.owner.flags_field & STATIC) == 0 &&
637 (flags & ENUM) != 0)
638 log.error(pos, "enums.must.be.static");
639 } else if (sym.owner.kind == TYP) {
640 mask = MemberClassFlags;
641 if (sym.owner.owner.kind == PCK ||
642 (sym.owner.flags_field & STATIC) != 0)
643 mask |= STATIC;
644 else if ((flags & ENUM) != 0)
645 log.error(pos, "enums.must.be.static");
646 // Nested interfaces and enums are always STATIC (Spec ???)
647 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
648 } else {
649 mask = ClassFlags;
650 }
651 // Interfaces are always ABSTRACT
652 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
654 if ((flags & ENUM) != 0) {
655 // enums can't be declared abstract or final
656 mask &= ~(ABSTRACT | FINAL);
657 implicit |= implicitEnumFinalFlag(tree);
658 }
659 // Imply STRICTFP if owner has STRICTFP set.
660 implicit |= sym.owner.flags_field & STRICTFP;
661 break;
662 default:
663 throw new AssertionError();
664 }
665 long illegal = flags & StandardFlags & ~mask;
666 if (illegal != 0) {
667 if ((illegal & INTERFACE) != 0) {
668 log.error(pos, "intf.not.allowed.here");
669 mask |= INTERFACE;
670 }
671 else {
672 log.error(pos,
673 "mod.not.allowed.here", TreeInfo.flagNames(illegal));
674 }
675 }
676 else if ((sym.kind == TYP ||
677 // ISSUE: Disallowing abstract&private is no longer appropriate
678 // in the presence of inner classes. Should it be deleted here?
679 checkDisjoint(pos, flags,
680 ABSTRACT,
681 PRIVATE | STATIC))
682 &&
683 checkDisjoint(pos, flags,
684 ABSTRACT | INTERFACE,
685 FINAL | NATIVE | SYNCHRONIZED)
686 &&
687 checkDisjoint(pos, flags,
688 PUBLIC,
689 PRIVATE | PROTECTED)
690 &&
691 checkDisjoint(pos, flags,
692 PRIVATE,
693 PUBLIC | PROTECTED)
694 &&
695 checkDisjoint(pos, flags,
696 FINAL,
697 VOLATILE)
698 &&
699 (sym.kind == TYP ||
700 checkDisjoint(pos, flags,
701 ABSTRACT | NATIVE,
702 STRICTFP))) {
703 // skip
704 }
705 return flags & (mask | ~StandardFlags) | implicit;
706 }
709 /** Determine if this enum should be implicitly final.
710 *
711 * If the enum has no specialized enum contants, it is final.
712 *
713 * If the enum does have specialized enum contants, it is
714 * <i>not</i> final.
715 */
716 private long implicitEnumFinalFlag(JCTree tree) {
717 if (tree.getTag() != JCTree.CLASSDEF) return 0;
718 class SpecialTreeVisitor extends JCTree.Visitor {
719 boolean specialized;
720 SpecialTreeVisitor() {
721 this.specialized = false;
722 };
724 public void visitTree(JCTree tree) { /* no-op */ }
726 public void visitVarDef(JCVariableDecl tree) {
727 if ((tree.mods.flags & ENUM) != 0) {
728 if (tree.init instanceof JCNewClass &&
729 ((JCNewClass) tree.init).def != null) {
730 specialized = true;
731 }
732 }
733 }
734 }
736 SpecialTreeVisitor sts = new SpecialTreeVisitor();
737 JCClassDecl cdef = (JCClassDecl) tree;
738 for (JCTree defs: cdef.defs) {
739 defs.accept(sts);
740 if (sts.specialized) return 0;
741 }
742 return FINAL;
743 }
745 /* *************************************************************************
746 * Type Validation
747 **************************************************************************/
749 /** Validate a type expression. That is,
750 * check that all type arguments of a parametric type are within
751 * their bounds. This must be done in a second phase after type attributon
752 * since a class might have a subclass as type parameter bound. E.g:
753 *
754 * class B<A extends C> { ... }
755 * class C extends B<C> { ... }
756 *
757 * and we can't make sure that the bound is already attributed because
758 * of possible cycles.
759 */
760 private Validator validator = new Validator();
762 /** Visitor method: Validate a type expression, if it is not null, catching
763 * and reporting any completion failures.
764 */
765 void validate(JCTree tree) {
766 try {
767 if (tree != null) tree.accept(validator);
768 } catch (CompletionFailure ex) {
769 completionError(tree.pos(), ex);
770 }
771 }
773 /** Visitor method: Validate a list of type expressions.
774 */
775 void validate(List<? extends JCTree> trees) {
776 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
777 validate(l.head);
778 }
780 /** Visitor method: Validate a list of type parameters.
781 */
782 void validateTypeParams(List<JCTypeParameter> trees) {
783 for (List<JCTypeParameter> l = trees; l.nonEmpty(); l = l.tail)
784 validate(l.head);
785 }
787 /** A visitor class for type validation.
788 */
789 class Validator extends JCTree.Visitor {
791 public void visitTypeArray(JCArrayTypeTree tree) {
792 validate(tree.elemtype);
793 }
795 public void visitTypeApply(JCTypeApply tree) {
796 if (tree.type.tag == CLASS) {
797 List<Type> formals = tree.type.tsym.type.getTypeArguments();
798 List<Type> actuals = types.capture(tree.type).getTypeArguments();
799 List<JCExpression> args = tree.arguments;
800 List<Type> forms = formals;
801 ListBuffer<TypeVar> tvars_buf = new ListBuffer<TypeVar>();
803 // For matching pairs of actual argument types `a' and
804 // formal type parameters with declared bound `b' ...
805 while (args.nonEmpty() && forms.nonEmpty()) {
806 validate(args.head);
808 // exact type arguments needs to know their
809 // bounds (for upper and lower bound
810 // calculations). So we create new TypeVars with
811 // bounds substed with actuals.
812 tvars_buf.append(types.substBound(((TypeVar)forms.head),
813 formals,
814 actuals));
816 args = args.tail;
817 forms = forms.tail;
818 }
820 args = tree.arguments;
821 List<TypeVar> tvars = tvars_buf.toList();
822 while (args.nonEmpty() && tvars.nonEmpty()) {
823 // Let the actual arguments know their bound
824 args.head.type.withTypeVar(tvars.head);
825 args = args.tail;
826 tvars = tvars.tail;
827 }
829 args = tree.arguments;
830 tvars = tvars_buf.toList();
831 while (args.nonEmpty() && tvars.nonEmpty()) {
832 checkExtends(args.head.pos(),
833 actuals.head,
834 tvars.head);
835 args = args.tail;
836 tvars = tvars.tail;
837 actuals = actuals.tail;
838 }
840 // Check that this type is either fully parameterized, or
841 // not parameterized at all.
842 if (tree.type.getEnclosingType().isRaw())
843 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
844 if (tree.clazz.getTag() == JCTree.SELECT)
845 visitSelectInternal((JCFieldAccess)tree.clazz);
846 }
847 }
849 public void visitTypeParameter(JCTypeParameter tree) {
850 validate(tree.bounds);
851 checkClassBounds(tree.pos(), tree.type);
852 }
854 @Override
855 public void visitWildcard(JCWildcard tree) {
856 if (tree.inner != null)
857 validate(tree.inner);
858 }
860 public void visitSelect(JCFieldAccess tree) {
861 if (tree.type.tag == CLASS) {
862 visitSelectInternal(tree);
864 // Check that this type is either fully parameterized, or
865 // not parameterized at all.
866 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
867 log.error(tree.pos(), "improperly.formed.type.param.missing");
868 }
869 }
870 public void visitSelectInternal(JCFieldAccess tree) {
871 if (tree.type.getEnclosingType().tag != CLASS &&
872 tree.selected.type.isParameterized()) {
873 // The enclosing type is not a class, so we are
874 // looking at a static member type. However, the
875 // qualifying expression is parameterized.
876 log.error(tree.pos(), "cant.select.static.class.from.param.type");
877 } else {
878 // otherwise validate the rest of the expression
879 validate(tree.selected);
880 }
881 }
883 /** Default visitor method: do nothing.
884 */
885 public void visitTree(JCTree tree) {
886 }
887 }
889 /* *************************************************************************
890 * Exception checking
891 **************************************************************************/
893 /* The following methods treat classes as sets that contain
894 * the class itself and all their subclasses
895 */
897 /** Is given type a subtype of some of the types in given list?
898 */
899 boolean subset(Type t, List<Type> ts) {
900 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
901 if (types.isSubtype(t, l.head)) return true;
902 return false;
903 }
905 /** Is given type a subtype or supertype of
906 * some of the types in given list?
907 */
908 boolean intersects(Type t, List<Type> ts) {
909 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
910 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
911 return false;
912 }
914 /** Add type set to given type list, unless it is a subclass of some class
915 * in the list.
916 */
917 List<Type> incl(Type t, List<Type> ts) {
918 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
919 }
921 /** Remove type set from type set list.
922 */
923 List<Type> excl(Type t, List<Type> ts) {
924 if (ts.isEmpty()) {
925 return ts;
926 } else {
927 List<Type> ts1 = excl(t, ts.tail);
928 if (types.isSubtype(ts.head, t)) return ts1;
929 else if (ts1 == ts.tail) return ts;
930 else return ts1.prepend(ts.head);
931 }
932 }
934 /** Form the union of two type set lists.
935 */
936 List<Type> union(List<Type> ts1, List<Type> ts2) {
937 List<Type> ts = ts1;
938 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
939 ts = incl(l.head, ts);
940 return ts;
941 }
943 /** Form the difference of two type lists.
944 */
945 List<Type> diff(List<Type> ts1, List<Type> ts2) {
946 List<Type> ts = ts1;
947 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
948 ts = excl(l.head, ts);
949 return ts;
950 }
952 /** Form the intersection of two type lists.
953 */
954 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
955 List<Type> ts = List.nil();
956 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
957 if (subset(l.head, ts2)) ts = incl(l.head, ts);
958 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
959 if (subset(l.head, ts1)) ts = incl(l.head, ts);
960 return ts;
961 }
963 /** Is exc an exception symbol that need not be declared?
964 */
965 boolean isUnchecked(ClassSymbol exc) {
966 return
967 exc.kind == ERR ||
968 exc.isSubClass(syms.errorType.tsym, types) ||
969 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
970 }
972 /** Is exc an exception type that need not be declared?
973 */
974 boolean isUnchecked(Type exc) {
975 return
976 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
977 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
978 exc.tag == BOT;
979 }
981 /** Same, but handling completion failures.
982 */
983 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
984 try {
985 return isUnchecked(exc);
986 } catch (CompletionFailure ex) {
987 completionError(pos, ex);
988 return true;
989 }
990 }
992 /** Is exc handled by given exception list?
993 */
994 boolean isHandled(Type exc, List<Type> handled) {
995 return isUnchecked(exc) || subset(exc, handled);
996 }
998 /** Return all exceptions in thrown list that are not in handled list.
999 * @param thrown The list of thrown exceptions.
1000 * @param handled The list of handled exceptions.
1001 */
1002 List<Type> unHandled(List<Type> thrown, List<Type> handled) {
1003 List<Type> unhandled = List.nil();
1004 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1005 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1006 return unhandled;
1007 }
1009 /* *************************************************************************
1010 * Overriding/Implementation checking
1011 **************************************************************************/
1013 /** The level of access protection given by a flag set,
1014 * where PRIVATE is highest and PUBLIC is lowest.
1015 */
1016 static int protection(long flags) {
1017 switch ((short)(flags & AccessFlags)) {
1018 case PRIVATE: return 3;
1019 case PROTECTED: return 1;
1020 default:
1021 case PUBLIC: return 0;
1022 case 0: return 2;
1023 }
1024 }
1026 /** A string describing the access permission given by a flag set.
1027 * This always returns a space-separated list of Java Keywords.
1028 */
1029 private static String protectionString(long flags) {
1030 long flags1 = flags & AccessFlags;
1031 return (flags1 == 0) ? "package" : TreeInfo.flagNames(flags1);
1032 }
1034 /** A customized "cannot override" error message.
1035 * @param m The overriding method.
1036 * @param other The overridden method.
1037 * @return An internationalized string.
1038 */
1039 static Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1040 String key;
1041 if ((other.owner.flags() & INTERFACE) == 0)
1042 key = "cant.override";
1043 else if ((m.owner.flags() & INTERFACE) == 0)
1044 key = "cant.implement";
1045 else
1046 key = "clashes.with";
1047 return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
1048 }
1050 /** A customized "override" warning message.
1051 * @param m The overriding method.
1052 * @param other The overridden method.
1053 * @return An internationalized string.
1054 */
1055 static Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1056 String key;
1057 if ((other.owner.flags() & INTERFACE) == 0)
1058 key = "unchecked.override";
1059 else if ((m.owner.flags() & INTERFACE) == 0)
1060 key = "unchecked.implement";
1061 else
1062 key = "unchecked.clash.with";
1063 return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
1064 }
1066 /** A customized "override" warning message.
1067 * @param m The overriding method.
1068 * @param other The overridden method.
1069 * @return An internationalized string.
1070 */
1071 static Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1072 String key;
1073 if ((other.owner.flags() & INTERFACE) == 0)
1074 key = "varargs.override";
1075 else if ((m.owner.flags() & INTERFACE) == 0)
1076 key = "varargs.implement";
1077 else
1078 key = "varargs.clash.with";
1079 return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
1080 }
1082 /** Check that this method conforms with overridden method 'other'.
1083 * where `origin' is the class where checking started.
1084 * Complications:
1085 * (1) Do not check overriding of synthetic methods
1086 * (reason: they might be final).
1087 * todo: check whether this is still necessary.
1088 * (2) Admit the case where an interface proxy throws fewer exceptions
1089 * than the method it implements. Augment the proxy methods with the
1090 * undeclared exceptions in this case.
1091 * (3) When generics are enabled, admit the case where an interface proxy
1092 * has a result type
1093 * extended by the result type of the method it implements.
1094 * Change the proxies result type to the smaller type in this case.
1095 *
1096 * @param tree The tree from which positions
1097 * are extracted for errors.
1098 * @param m The overriding method.
1099 * @param other The overridden method.
1100 * @param origin The class of which the overriding method
1101 * is a member.
1102 */
1103 void checkOverride(JCTree tree,
1104 MethodSymbol m,
1105 MethodSymbol other,
1106 ClassSymbol origin) {
1107 // Don't check overriding of synthetic methods or by bridge methods.
1108 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1109 return;
1110 }
1112 // Error if static method overrides instance method (JLS 8.4.6.2).
1113 if ((m.flags() & STATIC) != 0 &&
1114 (other.flags() & STATIC) == 0) {
1115 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1116 cannotOverride(m, other));
1117 return;
1118 }
1120 // Error if instance method overrides static or final
1121 // method (JLS 8.4.6.1).
1122 if ((other.flags() & FINAL) != 0 ||
1123 (m.flags() & STATIC) == 0 &&
1124 (other.flags() & STATIC) != 0) {
1125 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1126 cannotOverride(m, other),
1127 TreeInfo.flagNames(other.flags() & (FINAL | STATIC)));
1128 return;
1129 }
1131 if ((m.owner.flags() & ANNOTATION) != 0) {
1132 // handled in validateAnnotationMethod
1133 return;
1134 }
1136 // Error if overriding method has weaker access (JLS 8.4.6.3).
1137 if ((origin.flags() & INTERFACE) == 0 &&
1138 protection(m.flags()) > protection(other.flags())) {
1139 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1140 cannotOverride(m, other),
1141 protectionString(other.flags()));
1142 return;
1144 }
1146 Type mt = types.memberType(origin.type, m);
1147 Type ot = types.memberType(origin.type, other);
1148 // Error if overriding result type is different
1149 // (or, in the case of generics mode, not a subtype) of
1150 // overridden result type. We have to rename any type parameters
1151 // before comparing types.
1152 List<Type> mtvars = mt.getTypeArguments();
1153 List<Type> otvars = ot.getTypeArguments();
1154 Type mtres = mt.getReturnType();
1155 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1157 overrideWarner.warned = false;
1158 boolean resultTypesOK =
1159 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1160 if (!resultTypesOK) {
1161 if (!source.allowCovariantReturns() &&
1162 m.owner != origin &&
1163 m.owner.isSubClass(other.owner, types)) {
1164 // allow limited interoperability with covariant returns
1165 } else {
1166 typeError(TreeInfo.diagnosticPositionFor(m, tree),
1167 JCDiagnostic.fragment("override.incompatible.ret",
1168 cannotOverride(m, other)),
1169 mtres, otres);
1170 return;
1171 }
1172 } else if (overrideWarner.warned) {
1173 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1174 "prob.found.req",
1175 JCDiagnostic.fragment("override.unchecked.ret",
1176 uncheckedOverrides(m, other)),
1177 mtres, otres);
1178 }
1180 // Error if overriding method throws an exception not reported
1181 // by overridden method.
1182 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1183 List<Type> unhandled = unHandled(mt.getThrownTypes(), otthrown);
1184 if (unhandled.nonEmpty()) {
1185 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1186 "override.meth.doesnt.throw",
1187 cannotOverride(m, other),
1188 unhandled.head);
1189 return;
1190 }
1192 // Optional warning if varargs don't agree
1193 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1194 && lint.isEnabled(Lint.LintCategory.OVERRIDES)) {
1195 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1196 ((m.flags() & Flags.VARARGS) != 0)
1197 ? "override.varargs.missing"
1198 : "override.varargs.extra",
1199 varargsOverrides(m, other));
1200 }
1202 // Warn if instance method overrides bridge method (compiler spec ??)
1203 if ((other.flags() & BRIDGE) != 0) {
1204 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1205 uncheckedOverrides(m, other));
1206 }
1208 // Warn if a deprecated method overridden by a non-deprecated one.
1209 if ((other.flags() & DEPRECATED) != 0
1210 && (m.flags() & DEPRECATED) == 0
1211 && m.outermostClass() != other.outermostClass()
1212 && !isDeprecatedOverrideIgnorable(other, origin)) {
1213 warnDeprecated(TreeInfo.diagnosticPositionFor(m, tree), other);
1214 }
1215 }
1216 // where
1217 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1218 // If the method, m, is defined in an interface, then ignore the issue if the method
1219 // is only inherited via a supertype and also implemented in the supertype,
1220 // because in that case, we will rediscover the issue when examining the method
1221 // in the supertype.
1222 // If the method, m, is not defined in an interface, then the only time we need to
1223 // address the issue is when the method is the supertype implemementation: any other
1224 // case, we will have dealt with when examining the supertype classes
1225 ClassSymbol mc = m.enclClass();
1226 Type st = types.supertype(origin.type);
1227 if (st.tag != CLASS)
1228 return true;
1229 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1231 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1232 List<Type> intfs = types.interfaces(origin.type);
1233 return (intfs.contains(mc.type) ? false : (stimpl != null));
1234 }
1235 else
1236 return (stimpl != m);
1237 }
1240 // used to check if there were any unchecked conversions
1241 Warner overrideWarner = new Warner();
1243 /** Check that a class does not inherit two concrete methods
1244 * with the same signature.
1245 * @param pos Position to be used for error reporting.
1246 * @param site The class type to be checked.
1247 */
1248 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1249 Type sup = types.supertype(site);
1250 if (sup.tag != CLASS) return;
1252 for (Type t1 = sup;
1253 t1.tsym.type.isParameterized();
1254 t1 = types.supertype(t1)) {
1255 for (Scope.Entry e1 = t1.tsym.members().elems;
1256 e1 != null;
1257 e1 = e1.sibling) {
1258 Symbol s1 = e1.sym;
1259 if (s1.kind != MTH ||
1260 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1261 !s1.isInheritedIn(site.tsym, types) ||
1262 ((MethodSymbol)s1).implementation(site.tsym,
1263 types,
1264 true) != s1)
1265 continue;
1266 Type st1 = types.memberType(t1, s1);
1267 int s1ArgsLength = st1.getParameterTypes().length();
1268 if (st1 == s1.type) continue;
1270 for (Type t2 = sup;
1271 t2.tag == CLASS;
1272 t2 = types.supertype(t2)) {
1273 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1274 e2.scope != null;
1275 e2 = e2.next()) {
1276 Symbol s2 = e2.sym;
1277 if (s2 == s1 ||
1278 s2.kind != MTH ||
1279 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1280 s2.type.getParameterTypes().length() != s1ArgsLength ||
1281 !s2.isInheritedIn(site.tsym, types) ||
1282 ((MethodSymbol)s2).implementation(site.tsym,
1283 types,
1284 true) != s2)
1285 continue;
1286 Type st2 = types.memberType(t2, s2);
1287 if (types.overrideEquivalent(st1, st2))
1288 log.error(pos, "concrete.inheritance.conflict",
1289 s1, t1, s2, t2, sup);
1290 }
1291 }
1292 }
1293 }
1294 }
1296 /** Check that classes (or interfaces) do not each define an abstract
1297 * method with same name and arguments but incompatible return types.
1298 * @param pos Position to be used for error reporting.
1299 * @param t1 The first argument type.
1300 * @param t2 The second argument type.
1301 */
1302 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1303 Type t1,
1304 Type t2) {
1305 return checkCompatibleAbstracts(pos, t1, t2,
1306 types.makeCompoundType(t1, t2));
1307 }
1309 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1310 Type t1,
1311 Type t2,
1312 Type site) {
1313 Symbol sym = firstIncompatibility(t1, t2, site);
1314 if (sym != null) {
1315 log.error(pos, "types.incompatible.diff.ret",
1316 t1, t2, sym.name +
1317 "(" + types.memberType(t2, sym).getParameterTypes() + ")");
1318 return false;
1319 }
1320 return true;
1321 }
1323 /** Return the first method which is defined with same args
1324 * but different return types in two given interfaces, or null if none
1325 * exists.
1326 * @param t1 The first type.
1327 * @param t2 The second type.
1328 * @param site The most derived type.
1329 * @returns symbol from t2 that conflicts with one in t1.
1330 */
1331 private Symbol firstIncompatibility(Type t1, Type t2, Type site) {
1332 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1333 closure(t1, interfaces1);
1334 Map<TypeSymbol,Type> interfaces2;
1335 if (t1 == t2)
1336 interfaces2 = interfaces1;
1337 else
1338 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1340 for (Type t3 : interfaces1.values()) {
1341 for (Type t4 : interfaces2.values()) {
1342 Symbol s = firstDirectIncompatibility(t3, t4, site);
1343 if (s != null) return s;
1344 }
1345 }
1346 return null;
1347 }
1349 /** Compute all the supertypes of t, indexed by type symbol. */
1350 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1351 if (t.tag != CLASS) return;
1352 if (typeMap.put(t.tsym, t) == null) {
1353 closure(types.supertype(t), typeMap);
1354 for (Type i : types.interfaces(t))
1355 closure(i, typeMap);
1356 }
1357 }
1359 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1360 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1361 if (t.tag != CLASS) return;
1362 if (typesSkip.get(t.tsym) != null) return;
1363 if (typeMap.put(t.tsym, t) == null) {
1364 closure(types.supertype(t), typesSkip, typeMap);
1365 for (Type i : types.interfaces(t))
1366 closure(i, typesSkip, typeMap);
1367 }
1368 }
1370 /** Return the first method in t2 that conflicts with a method from t1. */
1371 private Symbol firstDirectIncompatibility(Type t1, Type t2, Type site) {
1372 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1373 Symbol s1 = e1.sym;
1374 Type st1 = null;
1375 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1376 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1377 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1378 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1379 Symbol s2 = e2.sym;
1380 if (s1 == s2) continue;
1381 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1382 if (st1 == null) st1 = types.memberType(t1, s1);
1383 Type st2 = types.memberType(t2, s2);
1384 if (types.overrideEquivalent(st1, st2)) {
1385 List<Type> tvars1 = st1.getTypeArguments();
1386 List<Type> tvars2 = st2.getTypeArguments();
1387 Type rt1 = st1.getReturnType();
1388 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1389 boolean compat =
1390 types.isSameType(rt1, rt2) ||
1391 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1392 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1393 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1394 checkCommonOverriderIn(s1,s2,site);
1395 if (!compat) return s2;
1396 }
1397 }
1398 }
1399 return null;
1400 }
1401 //WHERE
1402 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1403 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1404 Type st1 = types.memberType(site, s1);
1405 Type st2 = types.memberType(site, s2);
1406 closure(site, supertypes);
1407 for (Type t : supertypes.values()) {
1408 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1409 Symbol s3 = e.sym;
1410 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1411 Type st3 = types.memberType(site,s3);
1412 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1413 if (s3.owner == site.tsym) {
1414 return true;
1415 }
1416 List<Type> tvars1 = st1.getTypeArguments();
1417 List<Type> tvars2 = st2.getTypeArguments();
1418 List<Type> tvars3 = st3.getTypeArguments();
1419 Type rt1 = st1.getReturnType();
1420 Type rt2 = st2.getReturnType();
1421 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1422 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1423 boolean compat =
1424 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1425 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1426 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1427 if (compat)
1428 return true;
1429 }
1430 }
1431 }
1432 return false;
1433 }
1435 /** Check that a given method conforms with any method it overrides.
1436 * @param tree The tree from which positions are extracted
1437 * for errors.
1438 * @param m The overriding method.
1439 */
1440 void checkOverride(JCTree tree, MethodSymbol m) {
1441 ClassSymbol origin = (ClassSymbol)m.owner;
1442 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1443 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1444 log.error(tree.pos(), "enum.no.finalize");
1445 return;
1446 }
1447 for (Type t = types.supertype(origin.type); t.tag == CLASS;
1448 t = types.supertype(t)) {
1449 TypeSymbol c = t.tsym;
1450 Scope.Entry e = c.members().lookup(m.name);
1451 while (e.scope != null) {
1452 if (m.overrides(e.sym, origin, types, false))
1453 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1454 else if (e.sym.isInheritedIn(origin, types) && !m.isConstructor()) {
1455 Type er1 = m.erasure(types);
1456 Type er2 = e.sym.erasure(types);
1457 if (types.isSameType(er1,er2)) {
1458 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1459 "name.clash.same.erasure.no.override",
1460 m, m.location(),
1461 e.sym, e.sym.location());
1462 }
1463 }
1464 e = e.next();
1465 }
1466 }
1467 }
1469 /** Check that all abstract members of given class have definitions.
1470 * @param pos Position to be used for error reporting.
1471 * @param c The class.
1472 */
1473 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1474 try {
1475 MethodSymbol undef = firstUndef(c, c);
1476 if (undef != null) {
1477 if ((c.flags() & ENUM) != 0 &&
1478 types.supertype(c.type).tsym == syms.enumSym &&
1479 (c.flags() & FINAL) == 0) {
1480 // add the ABSTRACT flag to an enum
1481 c.flags_field |= ABSTRACT;
1482 } else {
1483 MethodSymbol undef1 =
1484 new MethodSymbol(undef.flags(), undef.name,
1485 types.memberType(c.type, undef), undef.owner);
1486 log.error(pos, "does.not.override.abstract",
1487 c, undef1, undef1.location());
1488 }
1489 }
1490 } catch (CompletionFailure ex) {
1491 completionError(pos, ex);
1492 }
1493 }
1494 //where
1495 /** Return first abstract member of class `c' that is not defined
1496 * in `impl', null if there is none.
1497 */
1498 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1499 MethodSymbol undef = null;
1500 // Do not bother to search in classes that are not abstract,
1501 // since they cannot have abstract members.
1502 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1503 Scope s = c.members();
1504 for (Scope.Entry e = s.elems;
1505 undef == null && e != null;
1506 e = e.sibling) {
1507 if (e.sym.kind == MTH &&
1508 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1509 MethodSymbol absmeth = (MethodSymbol)e.sym;
1510 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1511 if (implmeth == null || implmeth == absmeth)
1512 undef = absmeth;
1513 }
1514 }
1515 if (undef == null) {
1516 Type st = types.supertype(c.type);
1517 if (st.tag == CLASS)
1518 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1519 }
1520 for (List<Type> l = types.interfaces(c.type);
1521 undef == null && l.nonEmpty();
1522 l = l.tail) {
1523 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1524 }
1525 }
1526 return undef;
1527 }
1529 /** Check for cyclic references. Issue an error if the
1530 * symbol of the type referred to has a LOCKED flag set.
1531 *
1532 * @param pos Position to be used for error reporting.
1533 * @param t The type referred to.
1534 */
1535 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1536 checkNonCyclicInternal(pos, t);
1537 }
1540 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1541 checkNonCyclic1(pos, t, new HashSet<TypeVar>());
1542 }
1544 private void checkNonCyclic1(DiagnosticPosition pos, Type t, Set<TypeVar> seen) {
1545 final TypeVar tv;
1546 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
1547 return;
1548 if (seen.contains(t)) {
1549 tv = (TypeVar)t;
1550 tv.bound = new ErrorType();
1551 log.error(pos, "cyclic.inheritance", t);
1552 } else if (t.tag == TYPEVAR) {
1553 tv = (TypeVar)t;
1554 seen.add(tv);
1555 for (Type b : types.getBounds(tv))
1556 checkNonCyclic1(pos, b, seen);
1557 }
1558 }
1560 /** Check for cyclic references. Issue an error if the
1561 * symbol of the type referred to has a LOCKED flag set.
1562 *
1563 * @param pos Position to be used for error reporting.
1564 * @param t The type referred to.
1565 * @returns True if the check completed on all attributed classes
1566 */
1567 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1568 boolean complete = true; // was the check complete?
1569 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1570 Symbol c = t.tsym;
1571 if ((c.flags_field & ACYCLIC) != 0) return true;
1573 if ((c.flags_field & LOCKED) != 0) {
1574 noteCyclic(pos, (ClassSymbol)c);
1575 } else if (!c.type.isErroneous()) {
1576 try {
1577 c.flags_field |= LOCKED;
1578 if (c.type.tag == CLASS) {
1579 ClassType clazz = (ClassType)c.type;
1580 if (clazz.interfaces_field != null)
1581 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1582 complete &= checkNonCyclicInternal(pos, l.head);
1583 if (clazz.supertype_field != null) {
1584 Type st = clazz.supertype_field;
1585 if (st != null && st.tag == CLASS)
1586 complete &= checkNonCyclicInternal(pos, st);
1587 }
1588 if (c.owner.kind == TYP)
1589 complete &= checkNonCyclicInternal(pos, c.owner.type);
1590 }
1591 } finally {
1592 c.flags_field &= ~LOCKED;
1593 }
1594 }
1595 if (complete)
1596 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
1597 if (complete) c.flags_field |= ACYCLIC;
1598 return complete;
1599 }
1601 /** Note that we found an inheritance cycle. */
1602 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
1603 log.error(pos, "cyclic.inheritance", c);
1604 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
1605 l.head = new ErrorType((ClassSymbol)l.head.tsym);
1606 Type st = types.supertype(c.type);
1607 if (st.tag == CLASS)
1608 ((ClassType)c.type).supertype_field = new ErrorType((ClassSymbol)st.tsym);
1609 c.type = new ErrorType(c);
1610 c.flags_field |= ACYCLIC;
1611 }
1613 /** Check that all methods which implement some
1614 * method conform to the method they implement.
1615 * @param tree The class definition whose members are checked.
1616 */
1617 void checkImplementations(JCClassDecl tree) {
1618 checkImplementations(tree, tree.sym);
1619 }
1620 //where
1621 /** Check that all methods which implement some
1622 * method in `ic' conform to the method they implement.
1623 */
1624 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
1625 ClassSymbol origin = tree.sym;
1626 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
1627 ClassSymbol lc = (ClassSymbol)l.head.tsym;
1628 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
1629 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
1630 if (e.sym.kind == MTH &&
1631 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
1632 MethodSymbol absmeth = (MethodSymbol)e.sym;
1633 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
1634 if (implmeth != null && implmeth != absmeth &&
1635 (implmeth.owner.flags() & INTERFACE) ==
1636 (origin.flags() & INTERFACE)) {
1637 // don't check if implmeth is in a class, yet
1638 // origin is an interface. This case arises only
1639 // if implmeth is declared in Object. The reason is
1640 // that interfaces really don't inherit from
1641 // Object it's just that the compiler represents
1642 // things that way.
1643 checkOverride(tree, implmeth, absmeth, origin);
1644 }
1645 }
1646 }
1647 }
1648 }
1649 }
1651 /** Check that all abstract methods implemented by a class are
1652 * mutually compatible.
1653 * @param pos Position to be used for error reporting.
1654 * @param c The class whose interfaces are checked.
1655 */
1656 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
1657 List<Type> supertypes = types.interfaces(c);
1658 Type supertype = types.supertype(c);
1659 if (supertype.tag == CLASS &&
1660 (supertype.tsym.flags() & ABSTRACT) != 0)
1661 supertypes = supertypes.prepend(supertype);
1662 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
1663 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
1664 !checkCompatibleAbstracts(pos, l.head, l.head, c))
1665 return;
1666 for (List<Type> m = supertypes; m != l; m = m.tail)
1667 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
1668 return;
1669 }
1670 checkCompatibleConcretes(pos, c);
1671 }
1673 /** Check that class c does not implement directly or indirectly
1674 * the same parameterized interface with two different argument lists.
1675 * @param pos Position to be used for error reporting.
1676 * @param type The type whose interfaces are checked.
1677 */
1678 void checkClassBounds(DiagnosticPosition pos, Type type) {
1679 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
1680 }
1681 //where
1682 /** Enter all interfaces of type `type' into the hash table `seensofar'
1683 * with their class symbol as key and their type as value. Make
1684 * sure no class is entered with two different types.
1685 */
1686 void checkClassBounds(DiagnosticPosition pos,
1687 Map<TypeSymbol,Type> seensofar,
1688 Type type) {
1689 if (type.isErroneous()) return;
1690 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
1691 Type it = l.head;
1692 Type oldit = seensofar.put(it.tsym, it);
1693 if (oldit != null) {
1694 List<Type> oldparams = oldit.allparams();
1695 List<Type> newparams = it.allparams();
1696 if (!types.containsTypeEquivalent(oldparams, newparams))
1697 log.error(pos, "cant.inherit.diff.arg",
1698 it.tsym, Type.toString(oldparams),
1699 Type.toString(newparams));
1700 }
1701 checkClassBounds(pos, seensofar, it);
1702 }
1703 Type st = types.supertype(type);
1704 if (st != null) checkClassBounds(pos, seensofar, st);
1705 }
1707 /** Enter interface into into set.
1708 * If it existed already, issue a "repeated interface" error.
1709 */
1710 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
1711 if (its.contains(it))
1712 log.error(pos, "repeated.interface");
1713 else {
1714 its.add(it);
1715 }
1716 }
1718 /* *************************************************************************
1719 * Check annotations
1720 **************************************************************************/
1722 /** Annotation types are restricted to primitives, String, an
1723 * enum, an annotation, Class, Class<?>, Class<? extends
1724 * Anything>, arrays of the preceding.
1725 */
1726 void validateAnnotationType(JCTree restype) {
1727 // restype may be null if an error occurred, so don't bother validating it
1728 if (restype != null) {
1729 validateAnnotationType(restype.pos(), restype.type);
1730 }
1731 }
1733 void validateAnnotationType(DiagnosticPosition pos, Type type) {
1734 if (type.isPrimitive()) return;
1735 if (types.isSameType(type, syms.stringType)) return;
1736 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
1737 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
1738 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
1739 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
1740 validateAnnotationType(pos, types.elemtype(type));
1741 return;
1742 }
1743 log.error(pos, "invalid.annotation.member.type");
1744 }
1746 /**
1747 * "It is also a compile-time error if any method declared in an
1748 * annotation type has a signature that is override-equivalent to
1749 * that of any public or protected method declared in class Object
1750 * or in the interface annotation.Annotation."
1751 *
1752 * @jls3 9.6 Annotation Types
1753 */
1754 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
1755 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
1756 Scope s = sup.tsym.members();
1757 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
1758 if (e.sym.kind == MTH &&
1759 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
1760 types.overrideEquivalent(m.type, e.sym.type))
1761 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
1762 }
1763 }
1764 }
1766 /** Check the annotations of a symbol.
1767 */
1768 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
1769 if (skipAnnotations) return;
1770 for (JCAnnotation a : annotations)
1771 validateAnnotation(a, s);
1772 }
1774 /** Check an annotation of a symbol.
1775 */
1776 public void validateAnnotation(JCAnnotation a, Symbol s) {
1777 validateAnnotation(a);
1779 if (!annotationApplicable(a, s))
1780 log.error(a.pos(), "annotation.type.not.applicable");
1782 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
1783 if (!isOverrider(s))
1784 log.error(a.pos(), "method.does.not.override.superclass");
1785 }
1786 }
1788 /** Is s a method symbol that overrides a method in a superclass? */
1789 boolean isOverrider(Symbol s) {
1790 if (s.kind != MTH || s.isStatic())
1791 return false;
1792 MethodSymbol m = (MethodSymbol)s;
1793 TypeSymbol owner = (TypeSymbol)m.owner;
1794 for (Type sup : types.closure(owner.type)) {
1795 if (sup == owner.type)
1796 continue; // skip "this"
1797 Scope scope = sup.tsym.members();
1798 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
1799 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
1800 return true;
1801 }
1802 }
1803 return false;
1804 }
1806 /** Is the annotation applicable to the symbol? */
1807 boolean annotationApplicable(JCAnnotation a, Symbol s) {
1808 Attribute.Compound atTarget =
1809 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
1810 if (atTarget == null) return true;
1811 Attribute atValue = atTarget.member(names.value);
1812 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
1813 Attribute.Array arr = (Attribute.Array) atValue;
1814 for (Attribute app : arr.values) {
1815 if (!(app instanceof Attribute.Enum)) return true; // recovery
1816 Attribute.Enum e = (Attribute.Enum) app;
1817 if (e.value.name == names.TYPE)
1818 { if (s.kind == TYP) return true; }
1819 else if (e.value.name == names.FIELD)
1820 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
1821 else if (e.value.name == names.METHOD)
1822 { if (s.kind == MTH && !s.isConstructor()) return true; }
1823 else if (e.value.name == names.PARAMETER)
1824 { if (s.kind == VAR &&
1825 s.owner.kind == MTH &&
1826 (s.flags() & PARAMETER) != 0)
1827 return true;
1828 }
1829 else if (e.value.name == names.CONSTRUCTOR)
1830 { if (s.kind == MTH && s.isConstructor()) return true; }
1831 else if (e.value.name == names.LOCAL_VARIABLE)
1832 { if (s.kind == VAR && s.owner.kind == MTH &&
1833 (s.flags() & PARAMETER) == 0)
1834 return true;
1835 }
1836 else if (e.value.name == names.ANNOTATION_TYPE)
1837 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
1838 return true;
1839 }
1840 else if (e.value.name == names.PACKAGE)
1841 { if (s.kind == PCK) return true; }
1842 else
1843 return true; // recovery
1844 }
1845 return false;
1846 }
1848 /** Check an annotation value.
1849 */
1850 public void validateAnnotation(JCAnnotation a) {
1851 if (a.type.isErroneous()) return;
1853 // collect an inventory of the members
1854 Set<MethodSymbol> members = new HashSet<MethodSymbol>();
1855 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
1856 e != null;
1857 e = e.sibling)
1858 if (e.sym.kind == MTH)
1859 members.add((MethodSymbol) e.sym);
1861 // count them off as they're annotated
1862 for (JCTree arg : a.args) {
1863 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
1864 JCAssign assign = (JCAssign) arg;
1865 Symbol m = TreeInfo.symbol(assign.lhs);
1866 if (m == null || m.type.isErroneous()) continue;
1867 if (!members.remove(m))
1868 log.error(arg.pos(), "duplicate.annotation.member.value",
1869 m.name, a.type);
1870 if (assign.rhs.getTag() == ANNOTATION)
1871 validateAnnotation((JCAnnotation)assign.rhs);
1872 }
1874 // all the remaining ones better have default values
1875 for (MethodSymbol m : members)
1876 if (m.defaultValue == null && !m.type.isErroneous())
1877 log.error(a.pos(), "annotation.missing.default.value",
1878 a.type, m.name);
1880 // special case: java.lang.annotation.Target must not have
1881 // repeated values in its value member
1882 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
1883 a.args.tail == null)
1884 return;
1886 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
1887 JCAssign assign = (JCAssign) a.args.head;
1888 Symbol m = TreeInfo.symbol(assign.lhs);
1889 if (m.name != names.value) return;
1890 JCTree rhs = assign.rhs;
1891 if (rhs.getTag() != JCTree.NEWARRAY) return;
1892 JCNewArray na = (JCNewArray) rhs;
1893 Set<Symbol> targets = new HashSet<Symbol>();
1894 for (JCTree elem : na.elems) {
1895 if (!targets.add(TreeInfo.symbol(elem))) {
1896 log.error(elem.pos(), "repeated.annotation.target");
1897 }
1898 }
1899 }
1901 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
1902 if (allowAnnotations &&
1903 lint.isEnabled(Lint.LintCategory.DEP_ANN) &&
1904 (s.flags() & DEPRECATED) != 0 &&
1905 !syms.deprecatedType.isErroneous() &&
1906 s.attribute(syms.deprecatedType.tsym) == null) {
1907 log.warning(pos, "missing.deprecated.annotation");
1908 }
1909 }
1911 /* *************************************************************************
1912 * Check for recursive annotation elements.
1913 **************************************************************************/
1915 /** Check for cycles in the graph of annotation elements.
1916 */
1917 void checkNonCyclicElements(JCClassDecl tree) {
1918 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
1919 assert (tree.sym.flags_field & LOCKED) == 0;
1920 try {
1921 tree.sym.flags_field |= LOCKED;
1922 for (JCTree def : tree.defs) {
1923 if (def.getTag() != JCTree.METHODDEF) continue;
1924 JCMethodDecl meth = (JCMethodDecl)def;
1925 checkAnnotationResType(meth.pos(), meth.restype.type);
1926 }
1927 } finally {
1928 tree.sym.flags_field &= ~LOCKED;
1929 tree.sym.flags_field |= ACYCLIC_ANN;
1930 }
1931 }
1933 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
1934 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
1935 return;
1936 if ((tsym.flags_field & LOCKED) != 0) {
1937 log.error(pos, "cyclic.annotation.element");
1938 return;
1939 }
1940 try {
1941 tsym.flags_field |= LOCKED;
1942 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
1943 Symbol s = e.sym;
1944 if (s.kind != Kinds.MTH)
1945 continue;
1946 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
1947 }
1948 } finally {
1949 tsym.flags_field &= ~LOCKED;
1950 tsym.flags_field |= ACYCLIC_ANN;
1951 }
1952 }
1954 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
1955 switch (type.tag) {
1956 case TypeTags.CLASS:
1957 if ((type.tsym.flags() & ANNOTATION) != 0)
1958 checkNonCyclicElementsInternal(pos, type.tsym);
1959 break;
1960 case TypeTags.ARRAY:
1961 checkAnnotationResType(pos, types.elemtype(type));
1962 break;
1963 default:
1964 break; // int etc
1965 }
1966 }
1968 /* *************************************************************************
1969 * Check for cycles in the constructor call graph.
1970 **************************************************************************/
1972 /** Check for cycles in the graph of constructors calling other
1973 * constructors.
1974 */
1975 void checkCyclicConstructors(JCClassDecl tree) {
1976 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
1978 // enter each constructor this-call into the map
1979 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
1980 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
1981 if (app == null) continue;
1982 JCMethodDecl meth = (JCMethodDecl) l.head;
1983 if (TreeInfo.name(app.meth) == names._this) {
1984 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
1985 } else {
1986 meth.sym.flags_field |= ACYCLIC;
1987 }
1988 }
1990 // Check for cycles in the map
1991 Symbol[] ctors = new Symbol[0];
1992 ctors = callMap.keySet().toArray(ctors);
1993 for (Symbol caller : ctors) {
1994 checkCyclicConstructor(tree, caller, callMap);
1995 }
1996 }
1998 /** Look in the map to see if the given constructor is part of a
1999 * call cycle.
2000 */
2001 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
2002 Map<Symbol,Symbol> callMap) {
2003 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
2004 if ((ctor.flags_field & LOCKED) != 0) {
2005 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
2006 "recursive.ctor.invocation");
2007 } else {
2008 ctor.flags_field |= LOCKED;
2009 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2010 ctor.flags_field &= ~LOCKED;
2011 }
2012 ctor.flags_field |= ACYCLIC;
2013 }
2014 }
2016 /* *************************************************************************
2017 * Miscellaneous
2018 **************************************************************************/
2020 /**
2021 * Return the opcode of the operator but emit an error if it is an
2022 * error.
2023 * @param pos position for error reporting.
2024 * @param operator an operator
2025 * @param tag a tree tag
2026 * @param left type of left hand side
2027 * @param right type of right hand side
2028 */
2029 int checkOperator(DiagnosticPosition pos,
2030 OperatorSymbol operator,
2031 int tag,
2032 Type left,
2033 Type right) {
2034 if (operator.opcode == ByteCodes.error) {
2035 log.error(pos,
2036 "operator.cant.be.applied",
2037 treeinfo.operatorName(tag),
2038 left + "," + right);
2039 }
2040 return operator.opcode;
2041 }
2044 /**
2045 * Check for division by integer constant zero
2046 * @param pos Position for error reporting.
2047 * @param operator The operator for the expression
2048 * @param operand The right hand operand for the expression
2049 */
2050 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
2051 if (operand.constValue() != null
2052 && lint.isEnabled(Lint.LintCategory.DIVZERO)
2053 && operand.tag <= LONG
2054 && ((Number) (operand.constValue())).longValue() == 0) {
2055 int opc = ((OperatorSymbol)operator).opcode;
2056 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
2057 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
2058 log.warning(pos, "div.zero");
2059 }
2060 }
2061 }
2063 /**
2064 * Check for empty statements after if
2065 */
2066 void checkEmptyIf(JCIf tree) {
2067 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(Lint.LintCategory.EMPTY))
2068 log.warning(tree.thenpart.pos(), "empty.if");
2069 }
2071 /** Check that symbol is unique in given scope.
2072 * @param pos Position for error reporting.
2073 * @param sym The symbol.
2074 * @param s The scope.
2075 */
2076 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2077 if (sym.type.isErroneous())
2078 return true;
2079 if (sym.owner.name == names.any) return false;
2080 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2081 if (sym != e.sym &&
2082 sym.kind == e.sym.kind &&
2083 sym.name != names.error &&
2084 (sym.kind != MTH || types.overrideEquivalent(sym.type, e.sym.type))) {
2085 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS))
2086 varargsDuplicateError(pos, sym, e.sym);
2087 else
2088 duplicateError(pos, e.sym);
2089 return false;
2090 }
2091 }
2092 return true;
2093 }
2095 /** Check that single-type import is not already imported or top-level defined,
2096 * but make an exception for two single-type imports which denote the same type.
2097 * @param pos Position for error reporting.
2098 * @param sym The symbol.
2099 * @param s The scope
2100 */
2101 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2102 return checkUniqueImport(pos, sym, s, false);
2103 }
2105 /** Check that static single-type import is not already imported or top-level defined,
2106 * but make an exception for two single-type imports which denote the same type.
2107 * @param pos Position for error reporting.
2108 * @param sym The symbol.
2109 * @param s The scope
2110 * @param staticImport Whether or not this was a static import
2111 */
2112 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2113 return checkUniqueImport(pos, sym, s, true);
2114 }
2116 /** Check that single-type import is not already imported or top-level defined,
2117 * but make an exception for two single-type imports which denote the same type.
2118 * @param pos Position for error reporting.
2119 * @param sym The symbol.
2120 * @param s The scope.
2121 * @param staticImport Whether or not this was a static import
2122 */
2123 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2124 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2125 // is encountered class entered via a class declaration?
2126 boolean isClassDecl = e.scope == s;
2127 if ((isClassDecl || sym != e.sym) &&
2128 sym.kind == e.sym.kind &&
2129 sym.name != names.error) {
2130 if (!e.sym.type.isErroneous()) {
2131 String what = e.sym.toString();
2132 if (!isClassDecl) {
2133 if (staticImport)
2134 log.error(pos, "already.defined.static.single.import", what);
2135 else
2136 log.error(pos, "already.defined.single.import", what);
2137 }
2138 else if (sym != e.sym)
2139 log.error(pos, "already.defined.this.unit", what);
2140 }
2141 return false;
2142 }
2143 }
2144 return true;
2145 }
2147 /** Check that a qualified name is in canonical form (for import decls).
2148 */
2149 public void checkCanonical(JCTree tree) {
2150 if (!isCanonical(tree))
2151 log.error(tree.pos(), "import.requires.canonical",
2152 TreeInfo.symbol(tree));
2153 }
2154 // where
2155 private boolean isCanonical(JCTree tree) {
2156 while (tree.getTag() == JCTree.SELECT) {
2157 JCFieldAccess s = (JCFieldAccess) tree;
2158 if (s.sym.owner != TreeInfo.symbol(s.selected))
2159 return false;
2160 tree = s.selected;
2161 }
2162 return true;
2163 }
2165 private class ConversionWarner extends Warner {
2166 final String key;
2167 final Type found;
2168 final Type expected;
2169 public ConversionWarner(DiagnosticPosition pos, String key, Type found, Type expected) {
2170 super(pos);
2171 this.key = key;
2172 this.found = found;
2173 this.expected = expected;
2174 }
2176 public void warnUnchecked() {
2177 boolean warned = this.warned;
2178 super.warnUnchecked();
2179 if (warned) return; // suppress redundant diagnostics
2180 Object problem = JCDiagnostic.fragment(key);
2181 Check.this.warnUnchecked(pos(), "prob.found.req", problem, found, expected);
2182 }
2183 }
2185 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2186 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2187 }
2189 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2190 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2191 }
2192 }
