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src/share/classes/com/sun/tools/javac/comp/Check.java@77dba8b57346
src/share/classes/com/sun/tools/javac/comp/Check.java
Thu, 24 Jul 2008 10:35:38 +0100
- author
- mcimadamore
- date
- Thu, 24 Jul 2008 10:35:38 +0100
- changeset 78
- 77dba8b57346
- parent 62
- 07c916ecfc71
- child 79
- 36df13bde238
- permissions
- -rw-r--r--
6651719: Compiler crashes possibly during forward reference of TypeParameter
Summary: compiler should apply capture conversion when checking for bound conformance
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 instanceof CapturedType)) {
426 a = types.upperBound(a);
427 for (List<Type> l = types.getBounds(bs); l.nonEmpty(); l = l.tail) {
428 if (!types.isSubtype(a, l.head)) {
429 log.error(pos, "not.within.bounds", a);
430 return;
431 }
432 }
433 }
434 else {
435 CapturedType ct = (CapturedType)a;
436 boolean ok = false;
437 switch (ct.wildcard.kind) {
438 case EXTENDS:
439 ok = types.isCastable(bs.getUpperBound(),
440 types.upperBound(a),
441 Warner.noWarnings);
442 break;
443 case SUPER:
444 ok = !types.notSoftSubtype(types.lowerBound(a),
445 bs.getUpperBound());
446 break;
447 case UNBOUND:
448 ok = true;
449 }
450 if (!ok)
451 log.error(pos, "not.within.bounds", a);
452 }
453 }
455 /** Check that type is different from 'void'.
456 * @param pos Position to be used for error reporting.
457 * @param t The type to be checked.
458 */
459 Type checkNonVoid(DiagnosticPosition pos, Type t) {
460 if (t.tag == VOID) {
461 log.error(pos, "void.not.allowed.here");
462 return syms.errType;
463 } else {
464 return t;
465 }
466 }
468 /** Check that type is a class or interface type.
469 * @param pos Position to be used for error reporting.
470 * @param t The type to be checked.
471 */
472 Type checkClassType(DiagnosticPosition pos, Type t) {
473 if (t.tag != CLASS && t.tag != ERROR)
474 return typeTagError(pos,
475 JCDiagnostic.fragment("type.req.class"),
476 (t.tag == TYPEVAR)
477 ? JCDiagnostic.fragment("type.parameter", t)
478 : t);
479 else
480 return t;
481 }
483 /** Check that type is a class or interface type.
484 * @param pos Position to be used for error reporting.
485 * @param t The type to be checked.
486 * @param noBounds True if type bounds are illegal here.
487 */
488 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
489 t = checkClassType(pos, t);
490 if (noBounds && t.isParameterized()) {
491 List<Type> args = t.getTypeArguments();
492 while (args.nonEmpty()) {
493 if (args.head.tag == WILDCARD)
494 return typeTagError(pos,
495 log.getLocalizedString("type.req.exact"),
496 args.head);
497 args = args.tail;
498 }
499 }
500 return t;
501 }
503 /** Check that type is a reifiable class, interface or array type.
504 * @param pos Position to be used for error reporting.
505 * @param t The type to be checked.
506 */
507 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
508 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
509 return typeTagError(pos,
510 JCDiagnostic.fragment("type.req.class.array"),
511 t);
512 } else if (!types.isReifiable(t)) {
513 log.error(pos, "illegal.generic.type.for.instof");
514 return syms.errType;
515 } else {
516 return t;
517 }
518 }
520 /** Check that type is a reference type, i.e. a class, interface or array type
521 * or a type variable.
522 * @param pos Position to be used for error reporting.
523 * @param t The type to be checked.
524 */
525 Type checkRefType(DiagnosticPosition pos, Type t) {
526 switch (t.tag) {
527 case CLASS:
528 case ARRAY:
529 case TYPEVAR:
530 case WILDCARD:
531 case ERROR:
532 return t;
533 default:
534 return typeTagError(pos,
535 JCDiagnostic.fragment("type.req.ref"),
536 t);
537 }
538 }
540 /** Check that type is a null or reference type.
541 * @param pos Position to be used for error reporting.
542 * @param t The type to be checked.
543 */
544 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
545 switch (t.tag) {
546 case CLASS:
547 case ARRAY:
548 case TYPEVAR:
549 case WILDCARD:
550 case BOT:
551 case ERROR:
552 return t;
553 default:
554 return typeTagError(pos,
555 JCDiagnostic.fragment("type.req.ref"),
556 t);
557 }
558 }
560 /** Check that flag set does not contain elements of two conflicting sets. s
561 * Return true if it doesn't.
562 * @param pos Position to be used for error reporting.
563 * @param flags The set of flags to be checked.
564 * @param set1 Conflicting flags set #1.
565 * @param set2 Conflicting flags set #2.
566 */
567 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
568 if ((flags & set1) != 0 && (flags & set2) != 0) {
569 log.error(pos,
570 "illegal.combination.of.modifiers",
571 TreeInfo.flagNames(TreeInfo.firstFlag(flags & set1)),
572 TreeInfo.flagNames(TreeInfo.firstFlag(flags & set2)));
573 return false;
574 } else
575 return true;
576 }
578 /** Check that given modifiers are legal for given symbol and
579 * return modifiers together with any implicit modififiers for that symbol.
580 * Warning: we can't use flags() here since this method
581 * is called during class enter, when flags() would cause a premature
582 * completion.
583 * @param pos Position to be used for error reporting.
584 * @param flags The set of modifiers given in a definition.
585 * @param sym The defined symbol.
586 */
587 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
588 long mask;
589 long implicit = 0;
590 switch (sym.kind) {
591 case VAR:
592 if (sym.owner.kind != TYP)
593 mask = LocalVarFlags;
594 else if ((sym.owner.flags_field & INTERFACE) != 0)
595 mask = implicit = InterfaceVarFlags;
596 else
597 mask = VarFlags;
598 break;
599 case MTH:
600 if (sym.name == names.init) {
601 if ((sym.owner.flags_field & ENUM) != 0) {
602 // enum constructors cannot be declared public or
603 // protected and must be implicitly or explicitly
604 // private
605 implicit = PRIVATE;
606 mask = PRIVATE;
607 } else
608 mask = ConstructorFlags;
609 } else if ((sym.owner.flags_field & INTERFACE) != 0)
610 mask = implicit = InterfaceMethodFlags;
611 else {
612 mask = MethodFlags;
613 }
614 // Imply STRICTFP if owner has STRICTFP set.
615 if (((flags|implicit) & Flags.ABSTRACT) == 0)
616 implicit |= sym.owner.flags_field & STRICTFP;
617 break;
618 case TYP:
619 if (sym.isLocal()) {
620 mask = LocalClassFlags;
621 if (sym.name.len == 0) { // Anonymous class
622 // Anonymous classes in static methods are themselves static;
623 // that's why we admit STATIC here.
624 mask |= STATIC;
625 // JLS: Anonymous classes are final.
626 implicit |= FINAL;
627 }
628 if ((sym.owner.flags_field & STATIC) == 0 &&
629 (flags & ENUM) != 0)
630 log.error(pos, "enums.must.be.static");
631 } else if (sym.owner.kind == TYP) {
632 mask = MemberClassFlags;
633 if (sym.owner.owner.kind == PCK ||
634 (sym.owner.flags_field & STATIC) != 0)
635 mask |= STATIC;
636 else if ((flags & ENUM) != 0)
637 log.error(pos, "enums.must.be.static");
638 // Nested interfaces and enums are always STATIC (Spec ???)
639 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
640 } else {
641 mask = ClassFlags;
642 }
643 // Interfaces are always ABSTRACT
644 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
646 if ((flags & ENUM) != 0) {
647 // enums can't be declared abstract or final
648 mask &= ~(ABSTRACT | FINAL);
649 implicit |= implicitEnumFinalFlag(tree);
650 }
651 // Imply STRICTFP if owner has STRICTFP set.
652 implicit |= sym.owner.flags_field & STRICTFP;
653 break;
654 default:
655 throw new AssertionError();
656 }
657 long illegal = flags & StandardFlags & ~mask;
658 if (illegal != 0) {
659 if ((illegal & INTERFACE) != 0) {
660 log.error(pos, "intf.not.allowed.here");
661 mask |= INTERFACE;
662 }
663 else {
664 log.error(pos,
665 "mod.not.allowed.here", TreeInfo.flagNames(illegal));
666 }
667 }
668 else if ((sym.kind == TYP ||
669 // ISSUE: Disallowing abstract&private is no longer appropriate
670 // in the presence of inner classes. Should it be deleted here?
671 checkDisjoint(pos, flags,
672 ABSTRACT,
673 PRIVATE | STATIC))
674 &&
675 checkDisjoint(pos, flags,
676 ABSTRACT | INTERFACE,
677 FINAL | NATIVE | SYNCHRONIZED)
678 &&
679 checkDisjoint(pos, flags,
680 PUBLIC,
681 PRIVATE | PROTECTED)
682 &&
683 checkDisjoint(pos, flags,
684 PRIVATE,
685 PUBLIC | PROTECTED)
686 &&
687 checkDisjoint(pos, flags,
688 FINAL,
689 VOLATILE)
690 &&
691 (sym.kind == TYP ||
692 checkDisjoint(pos, flags,
693 ABSTRACT | NATIVE,
694 STRICTFP))) {
695 // skip
696 }
697 return flags & (mask | ~StandardFlags) | implicit;
698 }
701 /** Determine if this enum should be implicitly final.
702 *
703 * If the enum has no specialized enum contants, it is final.
704 *
705 * If the enum does have specialized enum contants, it is
706 * <i>not</i> final.
707 */
708 private long implicitEnumFinalFlag(JCTree tree) {
709 if (tree.getTag() != JCTree.CLASSDEF) return 0;
710 class SpecialTreeVisitor extends JCTree.Visitor {
711 boolean specialized;
712 SpecialTreeVisitor() {
713 this.specialized = false;
714 };
716 public void visitTree(JCTree tree) { /* no-op */ }
718 public void visitVarDef(JCVariableDecl tree) {
719 if ((tree.mods.flags & ENUM) != 0) {
720 if (tree.init instanceof JCNewClass &&
721 ((JCNewClass) tree.init).def != null) {
722 specialized = true;
723 }
724 }
725 }
726 }
728 SpecialTreeVisitor sts = new SpecialTreeVisitor();
729 JCClassDecl cdef = (JCClassDecl) tree;
730 for (JCTree defs: cdef.defs) {
731 defs.accept(sts);
732 if (sts.specialized) return 0;
733 }
734 return FINAL;
735 }
737 /* *************************************************************************
738 * Type Validation
739 **************************************************************************/
741 /** Validate a type expression. That is,
742 * check that all type arguments of a parametric type are within
743 * their bounds. This must be done in a second phase after type attributon
744 * since a class might have a subclass as type parameter bound. E.g:
745 *
746 * class B<A extends C> { ... }
747 * class C extends B<C> { ... }
748 *
749 * and we can't make sure that the bound is already attributed because
750 * of possible cycles.
751 */
752 private Validator validator = new Validator();
754 /** Visitor method: Validate a type expression, if it is not null, catching
755 * and reporting any completion failures.
756 */
757 void validate(JCTree tree) {
758 try {
759 if (tree != null) tree.accept(validator);
760 } catch (CompletionFailure ex) {
761 completionError(tree.pos(), ex);
762 }
763 }
765 /** Visitor method: Validate a list of type expressions.
766 */
767 void validate(List<? extends JCTree> trees) {
768 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
769 validate(l.head);
770 }
772 /** Visitor method: Validate a list of type parameters.
773 */
774 void validateTypeParams(List<JCTypeParameter> trees) {
775 for (List<JCTypeParameter> l = trees; l.nonEmpty(); l = l.tail)
776 validate(l.head);
777 }
779 /** A visitor class for type validation.
780 */
781 class Validator extends JCTree.Visitor {
783 public void visitTypeArray(JCArrayTypeTree tree) {
784 validate(tree.elemtype);
785 }
787 public void visitTypeApply(JCTypeApply tree) {
788 if (tree.type.tag == CLASS) {
789 List<Type> formals = tree.type.tsym.type.getTypeArguments();
790 List<Type> actuals = types.capture(tree.type).getTypeArguments();
791 List<JCExpression> args = tree.arguments;
792 List<Type> forms = formals;
793 ListBuffer<TypeVar> tvars_buf = new ListBuffer<TypeVar>();
795 // For matching pairs of actual argument types `a' and
796 // formal type parameters with declared bound `b' ...
797 while (args.nonEmpty() && forms.nonEmpty()) {
798 validate(args.head);
800 // exact type arguments needs to know their
801 // bounds (for upper and lower bound
802 // calculations). So we create new TypeVars with
803 // bounds substed with actuals.
804 tvars_buf.append(types.substBound(((TypeVar)forms.head),
805 formals,
806 actuals));
808 args = args.tail;
809 forms = forms.tail;
810 }
812 args = tree.arguments;
813 List<TypeVar> tvars = tvars_buf.toList();
814 while (args.nonEmpty() && tvars.nonEmpty()) {
815 // Let the actual arguments know their bound
816 args.head.type.withTypeVar(tvars.head);
817 args = args.tail;
818 tvars = tvars.tail;
819 }
821 args = tree.arguments;
822 tvars = tvars_buf.toList();
823 while (args.nonEmpty() && tvars.nonEmpty()) {
824 checkExtends(args.head.pos(),
825 actuals.head,
826 tvars.head);
827 args = args.tail;
828 tvars = tvars.tail;
829 actuals = actuals.tail;
830 }
832 // Check that this type is either fully parameterized, or
833 // not parameterized at all.
834 if (tree.type.getEnclosingType().isRaw())
835 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
836 if (tree.clazz.getTag() == JCTree.SELECT)
837 visitSelectInternal((JCFieldAccess)tree.clazz);
838 }
839 }
841 public void visitTypeParameter(JCTypeParameter tree) {
842 validate(tree.bounds);
843 checkClassBounds(tree.pos(), tree.type);
844 }
846 @Override
847 public void visitWildcard(JCWildcard tree) {
848 if (tree.inner != null)
849 validate(tree.inner);
850 }
852 public void visitSelect(JCFieldAccess tree) {
853 if (tree.type.tag == CLASS) {
854 visitSelectInternal(tree);
856 // Check that this type is either fully parameterized, or
857 // not parameterized at all.
858 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
859 log.error(tree.pos(), "improperly.formed.type.param.missing");
860 }
861 }
862 public void visitSelectInternal(JCFieldAccess tree) {
863 if (tree.type.getEnclosingType().tag != CLASS &&
864 tree.selected.type.isParameterized()) {
865 // The enclosing type is not a class, so we are
866 // looking at a static member type. However, the
867 // qualifying expression is parameterized.
868 log.error(tree.pos(), "cant.select.static.class.from.param.type");
869 } else {
870 // otherwise validate the rest of the expression
871 validate(tree.selected);
872 }
873 }
875 /** Default visitor method: do nothing.
876 */
877 public void visitTree(JCTree tree) {
878 }
879 }
881 /* *************************************************************************
882 * Exception checking
883 **************************************************************************/
885 /* The following methods treat classes as sets that contain
886 * the class itself and all their subclasses
887 */
889 /** Is given type a subtype of some of the types in given list?
890 */
891 boolean subset(Type t, List<Type> ts) {
892 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
893 if (types.isSubtype(t, l.head)) return true;
894 return false;
895 }
897 /** Is given type a subtype or supertype of
898 * some of the types in given list?
899 */
900 boolean intersects(Type t, List<Type> ts) {
901 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
902 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
903 return false;
904 }
906 /** Add type set to given type list, unless it is a subclass of some class
907 * in the list.
908 */
909 List<Type> incl(Type t, List<Type> ts) {
910 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
911 }
913 /** Remove type set from type set list.
914 */
915 List<Type> excl(Type t, List<Type> ts) {
916 if (ts.isEmpty()) {
917 return ts;
918 } else {
919 List<Type> ts1 = excl(t, ts.tail);
920 if (types.isSubtype(ts.head, t)) return ts1;
921 else if (ts1 == ts.tail) return ts;
922 else return ts1.prepend(ts.head);
923 }
924 }
926 /** Form the union of two type set lists.
927 */
928 List<Type> union(List<Type> ts1, List<Type> ts2) {
929 List<Type> ts = ts1;
930 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
931 ts = incl(l.head, ts);
932 return ts;
933 }
935 /** Form the difference of two type lists.
936 */
937 List<Type> diff(List<Type> ts1, List<Type> ts2) {
938 List<Type> ts = ts1;
939 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
940 ts = excl(l.head, ts);
941 return ts;
942 }
944 /** Form the intersection of two type lists.
945 */
946 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
947 List<Type> ts = List.nil();
948 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
949 if (subset(l.head, ts2)) ts = incl(l.head, ts);
950 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
951 if (subset(l.head, ts1)) ts = incl(l.head, ts);
952 return ts;
953 }
955 /** Is exc an exception symbol that need not be declared?
956 */
957 boolean isUnchecked(ClassSymbol exc) {
958 return
959 exc.kind == ERR ||
960 exc.isSubClass(syms.errorType.tsym, types) ||
961 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
962 }
964 /** Is exc an exception type that need not be declared?
965 */
966 boolean isUnchecked(Type exc) {
967 return
968 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
969 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
970 exc.tag == BOT;
971 }
973 /** Same, but handling completion failures.
974 */
975 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
976 try {
977 return isUnchecked(exc);
978 } catch (CompletionFailure ex) {
979 completionError(pos, ex);
980 return true;
981 }
982 }
984 /** Is exc handled by given exception list?
985 */
986 boolean isHandled(Type exc, List<Type> handled) {
987 return isUnchecked(exc) || subset(exc, handled);
988 }
990 /** Return all exceptions in thrown list that are not in handled list.
991 * @param thrown The list of thrown exceptions.
992 * @param handled The list of handled exceptions.
993 */
994 List<Type> unHandled(List<Type> thrown, List<Type> handled) {
995 List<Type> unhandled = List.nil();
996 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
997 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
998 return unhandled;
999 }
1001 /* *************************************************************************
1002 * Overriding/Implementation checking
1003 **************************************************************************/
1005 /** The level of access protection given by a flag set,
1006 * where PRIVATE is highest and PUBLIC is lowest.
1007 */
1008 static int protection(long flags) {
1009 switch ((short)(flags & AccessFlags)) {
1010 case PRIVATE: return 3;
1011 case PROTECTED: return 1;
1012 default:
1013 case PUBLIC: return 0;
1014 case 0: return 2;
1015 }
1016 }
1018 /** A string describing the access permission given by a flag set.
1019 * This always returns a space-separated list of Java Keywords.
1020 */
1021 private static String protectionString(long flags) {
1022 long flags1 = flags & AccessFlags;
1023 return (flags1 == 0) ? "package" : TreeInfo.flagNames(flags1);
1024 }
1026 /** A customized "cannot override" error message.
1027 * @param m The overriding method.
1028 * @param other The overridden method.
1029 * @return An internationalized string.
1030 */
1031 static Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1032 String key;
1033 if ((other.owner.flags() & INTERFACE) == 0)
1034 key = "cant.override";
1035 else if ((m.owner.flags() & INTERFACE) == 0)
1036 key = "cant.implement";
1037 else
1038 key = "clashes.with";
1039 return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
1040 }
1042 /** A customized "override" warning message.
1043 * @param m The overriding method.
1044 * @param other The overridden method.
1045 * @return An internationalized string.
1046 */
1047 static Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1048 String key;
1049 if ((other.owner.flags() & INTERFACE) == 0)
1050 key = "unchecked.override";
1051 else if ((m.owner.flags() & INTERFACE) == 0)
1052 key = "unchecked.implement";
1053 else
1054 key = "unchecked.clash.with";
1055 return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
1056 }
1058 /** A customized "override" warning message.
1059 * @param m The overriding method.
1060 * @param other The overridden method.
1061 * @return An internationalized string.
1062 */
1063 static Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1064 String key;
1065 if ((other.owner.flags() & INTERFACE) == 0)
1066 key = "varargs.override";
1067 else if ((m.owner.flags() & INTERFACE) == 0)
1068 key = "varargs.implement";
1069 else
1070 key = "varargs.clash.with";
1071 return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
1072 }
1074 /** Check that this method conforms with overridden method 'other'.
1075 * where `origin' is the class where checking started.
1076 * Complications:
1077 * (1) Do not check overriding of synthetic methods
1078 * (reason: they might be final).
1079 * todo: check whether this is still necessary.
1080 * (2) Admit the case where an interface proxy throws fewer exceptions
1081 * than the method it implements. Augment the proxy methods with the
1082 * undeclared exceptions in this case.
1083 * (3) When generics are enabled, admit the case where an interface proxy
1084 * has a result type
1085 * extended by the result type of the method it implements.
1086 * Change the proxies result type to the smaller type in this case.
1087 *
1088 * @param tree The tree from which positions
1089 * are extracted for errors.
1090 * @param m The overriding method.
1091 * @param other The overridden method.
1092 * @param origin The class of which the overriding method
1093 * is a member.
1094 */
1095 void checkOverride(JCTree tree,
1096 MethodSymbol m,
1097 MethodSymbol other,
1098 ClassSymbol origin) {
1099 // Don't check overriding of synthetic methods or by bridge methods.
1100 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1101 return;
1102 }
1104 // Error if static method overrides instance method (JLS 8.4.6.2).
1105 if ((m.flags() & STATIC) != 0 &&
1106 (other.flags() & STATIC) == 0) {
1107 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1108 cannotOverride(m, other));
1109 return;
1110 }
1112 // Error if instance method overrides static or final
1113 // method (JLS 8.4.6.1).
1114 if ((other.flags() & FINAL) != 0 ||
1115 (m.flags() & STATIC) == 0 &&
1116 (other.flags() & STATIC) != 0) {
1117 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1118 cannotOverride(m, other),
1119 TreeInfo.flagNames(other.flags() & (FINAL | STATIC)));
1120 return;
1121 }
1123 if ((m.owner.flags() & ANNOTATION) != 0) {
1124 // handled in validateAnnotationMethod
1125 return;
1126 }
1128 // Error if overriding method has weaker access (JLS 8.4.6.3).
1129 if ((origin.flags() & INTERFACE) == 0 &&
1130 protection(m.flags()) > protection(other.flags())) {
1131 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1132 cannotOverride(m, other),
1133 protectionString(other.flags()));
1134 return;
1136 }
1138 Type mt = types.memberType(origin.type, m);
1139 Type ot = types.memberType(origin.type, other);
1140 // Error if overriding result type is different
1141 // (or, in the case of generics mode, not a subtype) of
1142 // overridden result type. We have to rename any type parameters
1143 // before comparing types.
1144 List<Type> mtvars = mt.getTypeArguments();
1145 List<Type> otvars = ot.getTypeArguments();
1146 Type mtres = mt.getReturnType();
1147 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1149 overrideWarner.warned = false;
1150 boolean resultTypesOK =
1151 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1152 if (!resultTypesOK) {
1153 if (!source.allowCovariantReturns() &&
1154 m.owner != origin &&
1155 m.owner.isSubClass(other.owner, types)) {
1156 // allow limited interoperability with covariant returns
1157 } else {
1158 typeError(TreeInfo.diagnosticPositionFor(m, tree),
1159 JCDiagnostic.fragment("override.incompatible.ret",
1160 cannotOverride(m, other)),
1161 mtres, otres);
1162 return;
1163 }
1164 } else if (overrideWarner.warned) {
1165 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1166 "prob.found.req",
1167 JCDiagnostic.fragment("override.unchecked.ret",
1168 uncheckedOverrides(m, other)),
1169 mtres, otres);
1170 }
1172 // Error if overriding method throws an exception not reported
1173 // by overridden method.
1174 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1175 List<Type> unhandled = unHandled(mt.getThrownTypes(), otthrown);
1176 if (unhandled.nonEmpty()) {
1177 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1178 "override.meth.doesnt.throw",
1179 cannotOverride(m, other),
1180 unhandled.head);
1181 return;
1182 }
1184 // Optional warning if varargs don't agree
1185 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1186 && lint.isEnabled(Lint.LintCategory.OVERRIDES)) {
1187 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1188 ((m.flags() & Flags.VARARGS) != 0)
1189 ? "override.varargs.missing"
1190 : "override.varargs.extra",
1191 varargsOverrides(m, other));
1192 }
1194 // Warn if instance method overrides bridge method (compiler spec ??)
1195 if ((other.flags() & BRIDGE) != 0) {
1196 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1197 uncheckedOverrides(m, other));
1198 }
1200 // Warn if a deprecated method overridden by a non-deprecated one.
1201 if ((other.flags() & DEPRECATED) != 0
1202 && (m.flags() & DEPRECATED) == 0
1203 && m.outermostClass() != other.outermostClass()
1204 && !isDeprecatedOverrideIgnorable(other, origin)) {
1205 warnDeprecated(TreeInfo.diagnosticPositionFor(m, tree), other);
1206 }
1207 }
1208 // where
1209 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1210 // If the method, m, is defined in an interface, then ignore the issue if the method
1211 // is only inherited via a supertype and also implemented in the supertype,
1212 // because in that case, we will rediscover the issue when examining the method
1213 // in the supertype.
1214 // If the method, m, is not defined in an interface, then the only time we need to
1215 // address the issue is when the method is the supertype implemementation: any other
1216 // case, we will have dealt with when examining the supertype classes
1217 ClassSymbol mc = m.enclClass();
1218 Type st = types.supertype(origin.type);
1219 if (st.tag != CLASS)
1220 return true;
1221 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1223 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1224 List<Type> intfs = types.interfaces(origin.type);
1225 return (intfs.contains(mc.type) ? false : (stimpl != null));
1226 }
1227 else
1228 return (stimpl != m);
1229 }
1232 // used to check if there were any unchecked conversions
1233 Warner overrideWarner = new Warner();
1235 /** Check that a class does not inherit two concrete methods
1236 * with the same signature.
1237 * @param pos Position to be used for error reporting.
1238 * @param site The class type to be checked.
1239 */
1240 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1241 Type sup = types.supertype(site);
1242 if (sup.tag != CLASS) return;
1244 for (Type t1 = sup;
1245 t1.tsym.type.isParameterized();
1246 t1 = types.supertype(t1)) {
1247 for (Scope.Entry e1 = t1.tsym.members().elems;
1248 e1 != null;
1249 e1 = e1.sibling) {
1250 Symbol s1 = e1.sym;
1251 if (s1.kind != MTH ||
1252 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1253 !s1.isInheritedIn(site.tsym, types) ||
1254 ((MethodSymbol)s1).implementation(site.tsym,
1255 types,
1256 true) != s1)
1257 continue;
1258 Type st1 = types.memberType(t1, s1);
1259 int s1ArgsLength = st1.getParameterTypes().length();
1260 if (st1 == s1.type) continue;
1262 for (Type t2 = sup;
1263 t2.tag == CLASS;
1264 t2 = types.supertype(t2)) {
1265 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1266 e2.scope != null;
1267 e2 = e2.next()) {
1268 Symbol s2 = e2.sym;
1269 if (s2 == s1 ||
1270 s2.kind != MTH ||
1271 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1272 s2.type.getParameterTypes().length() != s1ArgsLength ||
1273 !s2.isInheritedIn(site.tsym, types) ||
1274 ((MethodSymbol)s2).implementation(site.tsym,
1275 types,
1276 true) != s2)
1277 continue;
1278 Type st2 = types.memberType(t2, s2);
1279 if (types.overrideEquivalent(st1, st2))
1280 log.error(pos, "concrete.inheritance.conflict",
1281 s1, t1, s2, t2, sup);
1282 }
1283 }
1284 }
1285 }
1286 }
1288 /** Check that classes (or interfaces) do not each define an abstract
1289 * method with same name and arguments but incompatible return types.
1290 * @param pos Position to be used for error reporting.
1291 * @param t1 The first argument type.
1292 * @param t2 The second argument type.
1293 */
1294 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1295 Type t1,
1296 Type t2) {
1297 return checkCompatibleAbstracts(pos, t1, t2,
1298 types.makeCompoundType(t1, t2));
1299 }
1301 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1302 Type t1,
1303 Type t2,
1304 Type site) {
1305 Symbol sym = firstIncompatibility(t1, t2, site);
1306 if (sym != null) {
1307 log.error(pos, "types.incompatible.diff.ret",
1308 t1, t2, sym.name +
1309 "(" + types.memberType(t2, sym).getParameterTypes() + ")");
1310 return false;
1311 }
1312 return true;
1313 }
1315 /** Return the first method which is defined with same args
1316 * but different return types in two given interfaces, or null if none
1317 * exists.
1318 * @param t1 The first type.
1319 * @param t2 The second type.
1320 * @param site The most derived type.
1321 * @returns symbol from t2 that conflicts with one in t1.
1322 */
1323 private Symbol firstIncompatibility(Type t1, Type t2, Type site) {
1324 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1325 closure(t1, interfaces1);
1326 Map<TypeSymbol,Type> interfaces2;
1327 if (t1 == t2)
1328 interfaces2 = interfaces1;
1329 else
1330 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1332 for (Type t3 : interfaces1.values()) {
1333 for (Type t4 : interfaces2.values()) {
1334 Symbol s = firstDirectIncompatibility(t3, t4, site);
1335 if (s != null) return s;
1336 }
1337 }
1338 return null;
1339 }
1341 /** Compute all the supertypes of t, indexed by type symbol. */
1342 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1343 if (t.tag != CLASS) return;
1344 if (typeMap.put(t.tsym, t) == null) {
1345 closure(types.supertype(t), typeMap);
1346 for (Type i : types.interfaces(t))
1347 closure(i, typeMap);
1348 }
1349 }
1351 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1352 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1353 if (t.tag != CLASS) return;
1354 if (typesSkip.get(t.tsym) != null) return;
1355 if (typeMap.put(t.tsym, t) == null) {
1356 closure(types.supertype(t), typesSkip, typeMap);
1357 for (Type i : types.interfaces(t))
1358 closure(i, typesSkip, typeMap);
1359 }
1360 }
1362 /** Return the first method in t2 that conflicts with a method from t1. */
1363 private Symbol firstDirectIncompatibility(Type t1, Type t2, Type site) {
1364 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1365 Symbol s1 = e1.sym;
1366 Type st1 = null;
1367 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1368 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1369 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1370 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1371 Symbol s2 = e2.sym;
1372 if (s1 == s2) continue;
1373 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1374 if (st1 == null) st1 = types.memberType(t1, s1);
1375 Type st2 = types.memberType(t2, s2);
1376 if (types.overrideEquivalent(st1, st2)) {
1377 List<Type> tvars1 = st1.getTypeArguments();
1378 List<Type> tvars2 = st2.getTypeArguments();
1379 Type rt1 = st1.getReturnType();
1380 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1381 boolean compat =
1382 types.isSameType(rt1, rt2) ||
1383 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1384 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1385 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1386 checkCommonOverriderIn(s1,s2,site);
1387 if (!compat) return s2;
1388 }
1389 }
1390 }
1391 return null;
1392 }
1393 //WHERE
1394 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1395 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1396 Type st1 = types.memberType(site, s1);
1397 Type st2 = types.memberType(site, s2);
1398 closure(site, supertypes);
1399 for (Type t : supertypes.values()) {
1400 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1401 Symbol s3 = e.sym;
1402 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1403 Type st3 = types.memberType(site,s3);
1404 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1405 if (s3.owner == site.tsym) {
1406 return true;
1407 }
1408 List<Type> tvars1 = st1.getTypeArguments();
1409 List<Type> tvars2 = st2.getTypeArguments();
1410 List<Type> tvars3 = st3.getTypeArguments();
1411 Type rt1 = st1.getReturnType();
1412 Type rt2 = st2.getReturnType();
1413 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1414 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1415 boolean compat =
1416 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1417 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1418 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1419 if (compat)
1420 return true;
1421 }
1422 }
1423 }
1424 return false;
1425 }
1427 /** Check that a given method conforms with any method it overrides.
1428 * @param tree The tree from which positions are extracted
1429 * for errors.
1430 * @param m The overriding method.
1431 */
1432 void checkOverride(JCTree tree, MethodSymbol m) {
1433 ClassSymbol origin = (ClassSymbol)m.owner;
1434 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1435 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1436 log.error(tree.pos(), "enum.no.finalize");
1437 return;
1438 }
1439 for (Type t = types.supertype(origin.type); t.tag == CLASS;
1440 t = types.supertype(t)) {
1441 TypeSymbol c = t.tsym;
1442 Scope.Entry e = c.members().lookup(m.name);
1443 while (e.scope != null) {
1444 if (m.overrides(e.sym, origin, types, false))
1445 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1446 else if (e.sym.isInheritedIn(origin, types) && !m.isConstructor()) {
1447 Type er1 = m.erasure(types);
1448 Type er2 = e.sym.erasure(types);
1449 if (types.isSameType(er1,er2)) {
1450 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1451 "name.clash.same.erasure.no.override",
1452 m, m.location(),
1453 e.sym, e.sym.location());
1454 }
1455 }
1456 e = e.next();
1457 }
1458 }
1459 }
1461 /** Check that all abstract members of given class have definitions.
1462 * @param pos Position to be used for error reporting.
1463 * @param c The class.
1464 */
1465 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1466 try {
1467 MethodSymbol undef = firstUndef(c, c);
1468 if (undef != null) {
1469 if ((c.flags() & ENUM) != 0 &&
1470 types.supertype(c.type).tsym == syms.enumSym &&
1471 (c.flags() & FINAL) == 0) {
1472 // add the ABSTRACT flag to an enum
1473 c.flags_field |= ABSTRACT;
1474 } else {
1475 MethodSymbol undef1 =
1476 new MethodSymbol(undef.flags(), undef.name,
1477 types.memberType(c.type, undef), undef.owner);
1478 log.error(pos, "does.not.override.abstract",
1479 c, undef1, undef1.location());
1480 }
1481 }
1482 } catch (CompletionFailure ex) {
1483 completionError(pos, ex);
1484 }
1485 }
1486 //where
1487 /** Return first abstract member of class `c' that is not defined
1488 * in `impl', null if there is none.
1489 */
1490 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1491 MethodSymbol undef = null;
1492 // Do not bother to search in classes that are not abstract,
1493 // since they cannot have abstract members.
1494 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1495 Scope s = c.members();
1496 for (Scope.Entry e = s.elems;
1497 undef == null && e != null;
1498 e = e.sibling) {
1499 if (e.sym.kind == MTH &&
1500 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1501 MethodSymbol absmeth = (MethodSymbol)e.sym;
1502 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1503 if (implmeth == null || implmeth == absmeth)
1504 undef = absmeth;
1505 }
1506 }
1507 if (undef == null) {
1508 Type st = types.supertype(c.type);
1509 if (st.tag == CLASS)
1510 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1511 }
1512 for (List<Type> l = types.interfaces(c.type);
1513 undef == null && l.nonEmpty();
1514 l = l.tail) {
1515 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1516 }
1517 }
1518 return undef;
1519 }
1521 /** Check for cyclic references. Issue an error if the
1522 * symbol of the type referred to has a LOCKED flag set.
1523 *
1524 * @param pos Position to be used for error reporting.
1525 * @param t The type referred to.
1526 */
1527 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1528 checkNonCyclicInternal(pos, t);
1529 }
1532 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1533 checkNonCyclic1(pos, t, new HashSet<TypeVar>());
1534 }
1536 private void checkNonCyclic1(DiagnosticPosition pos, Type t, Set<TypeVar> seen) {
1537 final TypeVar tv;
1538 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
1539 return;
1540 if (seen.contains(t)) {
1541 tv = (TypeVar)t;
1542 tv.bound = new ErrorType();
1543 log.error(pos, "cyclic.inheritance", t);
1544 } else if (t.tag == TYPEVAR) {
1545 tv = (TypeVar)t;
1546 seen.add(tv);
1547 for (Type b : types.getBounds(tv))
1548 checkNonCyclic1(pos, b, seen);
1549 }
1550 }
1552 /** Check for cyclic references. Issue an error if the
1553 * symbol of the type referred to has a LOCKED flag set.
1554 *
1555 * @param pos Position to be used for error reporting.
1556 * @param t The type referred to.
1557 * @returns True if the check completed on all attributed classes
1558 */
1559 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1560 boolean complete = true; // was the check complete?
1561 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1562 Symbol c = t.tsym;
1563 if ((c.flags_field & ACYCLIC) != 0) return true;
1565 if ((c.flags_field & LOCKED) != 0) {
1566 noteCyclic(pos, (ClassSymbol)c);
1567 } else if (!c.type.isErroneous()) {
1568 try {
1569 c.flags_field |= LOCKED;
1570 if (c.type.tag == CLASS) {
1571 ClassType clazz = (ClassType)c.type;
1572 if (clazz.interfaces_field != null)
1573 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1574 complete &= checkNonCyclicInternal(pos, l.head);
1575 if (clazz.supertype_field != null) {
1576 Type st = clazz.supertype_field;
1577 if (st != null && st.tag == CLASS)
1578 complete &= checkNonCyclicInternal(pos, st);
1579 }
1580 if (c.owner.kind == TYP)
1581 complete &= checkNonCyclicInternal(pos, c.owner.type);
1582 }
1583 } finally {
1584 c.flags_field &= ~LOCKED;
1585 }
1586 }
1587 if (complete)
1588 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
1589 if (complete) c.flags_field |= ACYCLIC;
1590 return complete;
1591 }
1593 /** Note that we found an inheritance cycle. */
1594 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
1595 log.error(pos, "cyclic.inheritance", c);
1596 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
1597 l.head = new ErrorType((ClassSymbol)l.head.tsym);
1598 Type st = types.supertype(c.type);
1599 if (st.tag == CLASS)
1600 ((ClassType)c.type).supertype_field = new ErrorType((ClassSymbol)st.tsym);
1601 c.type = new ErrorType(c);
1602 c.flags_field |= ACYCLIC;
1603 }
1605 /** Check that all methods which implement some
1606 * method conform to the method they implement.
1607 * @param tree The class definition whose members are checked.
1608 */
1609 void checkImplementations(JCClassDecl tree) {
1610 checkImplementations(tree, tree.sym);
1611 }
1612 //where
1613 /** Check that all methods which implement some
1614 * method in `ic' conform to the method they implement.
1615 */
1616 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
1617 ClassSymbol origin = tree.sym;
1618 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
1619 ClassSymbol lc = (ClassSymbol)l.head.tsym;
1620 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
1621 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
1622 if (e.sym.kind == MTH &&
1623 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
1624 MethodSymbol absmeth = (MethodSymbol)e.sym;
1625 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
1626 if (implmeth != null && implmeth != absmeth &&
1627 (implmeth.owner.flags() & INTERFACE) ==
1628 (origin.flags() & INTERFACE)) {
1629 // don't check if implmeth is in a class, yet
1630 // origin is an interface. This case arises only
1631 // if implmeth is declared in Object. The reason is
1632 // that interfaces really don't inherit from
1633 // Object it's just that the compiler represents
1634 // things that way.
1635 checkOverride(tree, implmeth, absmeth, origin);
1636 }
1637 }
1638 }
1639 }
1640 }
1641 }
1643 /** Check that all abstract methods implemented by a class are
1644 * mutually compatible.
1645 * @param pos Position to be used for error reporting.
1646 * @param c The class whose interfaces are checked.
1647 */
1648 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
1649 List<Type> supertypes = types.interfaces(c);
1650 Type supertype = types.supertype(c);
1651 if (supertype.tag == CLASS &&
1652 (supertype.tsym.flags() & ABSTRACT) != 0)
1653 supertypes = supertypes.prepend(supertype);
1654 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
1655 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
1656 !checkCompatibleAbstracts(pos, l.head, l.head, c))
1657 return;
1658 for (List<Type> m = supertypes; m != l; m = m.tail)
1659 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
1660 return;
1661 }
1662 checkCompatibleConcretes(pos, c);
1663 }
1665 /** Check that class c does not implement directly or indirectly
1666 * the same parameterized interface with two different argument lists.
1667 * @param pos Position to be used for error reporting.
1668 * @param type The type whose interfaces are checked.
1669 */
1670 void checkClassBounds(DiagnosticPosition pos, Type type) {
1671 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
1672 }
1673 //where
1674 /** Enter all interfaces of type `type' into the hash table `seensofar'
1675 * with their class symbol as key and their type as value. Make
1676 * sure no class is entered with two different types.
1677 */
1678 void checkClassBounds(DiagnosticPosition pos,
1679 Map<TypeSymbol,Type> seensofar,
1680 Type type) {
1681 if (type.isErroneous()) return;
1682 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
1683 Type it = l.head;
1684 Type oldit = seensofar.put(it.tsym, it);
1685 if (oldit != null) {
1686 List<Type> oldparams = oldit.allparams();
1687 List<Type> newparams = it.allparams();
1688 if (!types.containsTypeEquivalent(oldparams, newparams))
1689 log.error(pos, "cant.inherit.diff.arg",
1690 it.tsym, Type.toString(oldparams),
1691 Type.toString(newparams));
1692 }
1693 checkClassBounds(pos, seensofar, it);
1694 }
1695 Type st = types.supertype(type);
1696 if (st != null) checkClassBounds(pos, seensofar, st);
1697 }
1699 /** Enter interface into into set.
1700 * If it existed already, issue a "repeated interface" error.
1701 */
1702 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
1703 if (its.contains(it))
1704 log.error(pos, "repeated.interface");
1705 else {
1706 its.add(it);
1707 }
1708 }
1710 /* *************************************************************************
1711 * Check annotations
1712 **************************************************************************/
1714 /** Annotation types are restricted to primitives, String, an
1715 * enum, an annotation, Class, Class<?>, Class<? extends
1716 * Anything>, arrays of the preceding.
1717 */
1718 void validateAnnotationType(JCTree restype) {
1719 // restype may be null if an error occurred, so don't bother validating it
1720 if (restype != null) {
1721 validateAnnotationType(restype.pos(), restype.type);
1722 }
1723 }
1725 void validateAnnotationType(DiagnosticPosition pos, Type type) {
1726 if (type.isPrimitive()) return;
1727 if (types.isSameType(type, syms.stringType)) return;
1728 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
1729 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
1730 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
1731 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
1732 validateAnnotationType(pos, types.elemtype(type));
1733 return;
1734 }
1735 log.error(pos, "invalid.annotation.member.type");
1736 }
1738 /**
1739 * "It is also a compile-time error if any method declared in an
1740 * annotation type has a signature that is override-equivalent to
1741 * that of any public or protected method declared in class Object
1742 * or in the interface annotation.Annotation."
1743 *
1744 * @jls3 9.6 Annotation Types
1745 */
1746 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
1747 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
1748 Scope s = sup.tsym.members();
1749 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
1750 if (e.sym.kind == MTH &&
1751 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
1752 types.overrideEquivalent(m.type, e.sym.type))
1753 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
1754 }
1755 }
1756 }
1758 /** Check the annotations of a symbol.
1759 */
1760 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
1761 if (skipAnnotations) return;
1762 for (JCAnnotation a : annotations)
1763 validateAnnotation(a, s);
1764 }
1766 /** Check an annotation of a symbol.
1767 */
1768 public void validateAnnotation(JCAnnotation a, Symbol s) {
1769 validateAnnotation(a);
1771 if (!annotationApplicable(a, s))
1772 log.error(a.pos(), "annotation.type.not.applicable");
1774 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
1775 if (!isOverrider(s))
1776 log.error(a.pos(), "method.does.not.override.superclass");
1777 }
1778 }
1780 /** Is s a method symbol that overrides a method in a superclass? */
1781 boolean isOverrider(Symbol s) {
1782 if (s.kind != MTH || s.isStatic())
1783 return false;
1784 MethodSymbol m = (MethodSymbol)s;
1785 TypeSymbol owner = (TypeSymbol)m.owner;
1786 for (Type sup : types.closure(owner.type)) {
1787 if (sup == owner.type)
1788 continue; // skip "this"
1789 Scope scope = sup.tsym.members();
1790 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
1791 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
1792 return true;
1793 }
1794 }
1795 return false;
1796 }
1798 /** Is the annotation applicable to the symbol? */
1799 boolean annotationApplicable(JCAnnotation a, Symbol s) {
1800 Attribute.Compound atTarget =
1801 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
1802 if (atTarget == null) return true;
1803 Attribute atValue = atTarget.member(names.value);
1804 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
1805 Attribute.Array arr = (Attribute.Array) atValue;
1806 for (Attribute app : arr.values) {
1807 if (!(app instanceof Attribute.Enum)) return true; // recovery
1808 Attribute.Enum e = (Attribute.Enum) app;
1809 if (e.value.name == names.TYPE)
1810 { if (s.kind == TYP) return true; }
1811 else if (e.value.name == names.FIELD)
1812 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
1813 else if (e.value.name == names.METHOD)
1814 { if (s.kind == MTH && !s.isConstructor()) return true; }
1815 else if (e.value.name == names.PARAMETER)
1816 { if (s.kind == VAR &&
1817 s.owner.kind == MTH &&
1818 (s.flags() & PARAMETER) != 0)
1819 return true;
1820 }
1821 else if (e.value.name == names.CONSTRUCTOR)
1822 { if (s.kind == MTH && s.isConstructor()) return true; }
1823 else if (e.value.name == names.LOCAL_VARIABLE)
1824 { if (s.kind == VAR && s.owner.kind == MTH &&
1825 (s.flags() & PARAMETER) == 0)
1826 return true;
1827 }
1828 else if (e.value.name == names.ANNOTATION_TYPE)
1829 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
1830 return true;
1831 }
1832 else if (e.value.name == names.PACKAGE)
1833 { if (s.kind == PCK) return true; }
1834 else
1835 return true; // recovery
1836 }
1837 return false;
1838 }
1840 /** Check an annotation value.
1841 */
1842 public void validateAnnotation(JCAnnotation a) {
1843 if (a.type.isErroneous()) return;
1845 // collect an inventory of the members
1846 Set<MethodSymbol> members = new HashSet<MethodSymbol>();
1847 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
1848 e != null;
1849 e = e.sibling)
1850 if (e.sym.kind == MTH)
1851 members.add((MethodSymbol) e.sym);
1853 // count them off as they're annotated
1854 for (JCTree arg : a.args) {
1855 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
1856 JCAssign assign = (JCAssign) arg;
1857 Symbol m = TreeInfo.symbol(assign.lhs);
1858 if (m == null || m.type.isErroneous()) continue;
1859 if (!members.remove(m))
1860 log.error(arg.pos(), "duplicate.annotation.member.value",
1861 m.name, a.type);
1862 if (assign.rhs.getTag() == ANNOTATION)
1863 validateAnnotation((JCAnnotation)assign.rhs);
1864 }
1866 // all the remaining ones better have default values
1867 for (MethodSymbol m : members)
1868 if (m.defaultValue == null && !m.type.isErroneous())
1869 log.error(a.pos(), "annotation.missing.default.value",
1870 a.type, m.name);
1872 // special case: java.lang.annotation.Target must not have
1873 // repeated values in its value member
1874 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
1875 a.args.tail == null)
1876 return;
1878 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
1879 JCAssign assign = (JCAssign) a.args.head;
1880 Symbol m = TreeInfo.symbol(assign.lhs);
1881 if (m.name != names.value) return;
1882 JCTree rhs = assign.rhs;
1883 if (rhs.getTag() != JCTree.NEWARRAY) return;
1884 JCNewArray na = (JCNewArray) rhs;
1885 Set<Symbol> targets = new HashSet<Symbol>();
1886 for (JCTree elem : na.elems) {
1887 if (!targets.add(TreeInfo.symbol(elem))) {
1888 log.error(elem.pos(), "repeated.annotation.target");
1889 }
1890 }
1891 }
1893 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
1894 if (allowAnnotations &&
1895 lint.isEnabled(Lint.LintCategory.DEP_ANN) &&
1896 (s.flags() & DEPRECATED) != 0 &&
1897 !syms.deprecatedType.isErroneous() &&
1898 s.attribute(syms.deprecatedType.tsym) == null) {
1899 log.warning(pos, "missing.deprecated.annotation");
1900 }
1901 }
1903 /* *************************************************************************
1904 * Check for recursive annotation elements.
1905 **************************************************************************/
1907 /** Check for cycles in the graph of annotation elements.
1908 */
1909 void checkNonCyclicElements(JCClassDecl tree) {
1910 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
1911 assert (tree.sym.flags_field & LOCKED) == 0;
1912 try {
1913 tree.sym.flags_field |= LOCKED;
1914 for (JCTree def : tree.defs) {
1915 if (def.getTag() != JCTree.METHODDEF) continue;
1916 JCMethodDecl meth = (JCMethodDecl)def;
1917 checkAnnotationResType(meth.pos(), meth.restype.type);
1918 }
1919 } finally {
1920 tree.sym.flags_field &= ~LOCKED;
1921 tree.sym.flags_field |= ACYCLIC_ANN;
1922 }
1923 }
1925 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
1926 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
1927 return;
1928 if ((tsym.flags_field & LOCKED) != 0) {
1929 log.error(pos, "cyclic.annotation.element");
1930 return;
1931 }
1932 try {
1933 tsym.flags_field |= LOCKED;
1934 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
1935 Symbol s = e.sym;
1936 if (s.kind != Kinds.MTH)
1937 continue;
1938 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
1939 }
1940 } finally {
1941 tsym.flags_field &= ~LOCKED;
1942 tsym.flags_field |= ACYCLIC_ANN;
1943 }
1944 }
1946 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
1947 switch (type.tag) {
1948 case TypeTags.CLASS:
1949 if ((type.tsym.flags() & ANNOTATION) != 0)
1950 checkNonCyclicElementsInternal(pos, type.tsym);
1951 break;
1952 case TypeTags.ARRAY:
1953 checkAnnotationResType(pos, types.elemtype(type));
1954 break;
1955 default:
1956 break; // int etc
1957 }
1958 }
1960 /* *************************************************************************
1961 * Check for cycles in the constructor call graph.
1962 **************************************************************************/
1964 /** Check for cycles in the graph of constructors calling other
1965 * constructors.
1966 */
1967 void checkCyclicConstructors(JCClassDecl tree) {
1968 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
1970 // enter each constructor this-call into the map
1971 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
1972 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
1973 if (app == null) continue;
1974 JCMethodDecl meth = (JCMethodDecl) l.head;
1975 if (TreeInfo.name(app.meth) == names._this) {
1976 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
1977 } else {
1978 meth.sym.flags_field |= ACYCLIC;
1979 }
1980 }
1982 // Check for cycles in the map
1983 Symbol[] ctors = new Symbol[0];
1984 ctors = callMap.keySet().toArray(ctors);
1985 for (Symbol caller : ctors) {
1986 checkCyclicConstructor(tree, caller, callMap);
1987 }
1988 }
1990 /** Look in the map to see if the given constructor is part of a
1991 * call cycle.
1992 */
1993 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
1994 Map<Symbol,Symbol> callMap) {
1995 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
1996 if ((ctor.flags_field & LOCKED) != 0) {
1997 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
1998 "recursive.ctor.invocation");
1999 } else {
2000 ctor.flags_field |= LOCKED;
2001 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2002 ctor.flags_field &= ~LOCKED;
2003 }
2004 ctor.flags_field |= ACYCLIC;
2005 }
2006 }
2008 /* *************************************************************************
2009 * Miscellaneous
2010 **************************************************************************/
2012 /**
2013 * Return the opcode of the operator but emit an error if it is an
2014 * error.
2015 * @param pos position for error reporting.
2016 * @param operator an operator
2017 * @param tag a tree tag
2018 * @param left type of left hand side
2019 * @param right type of right hand side
2020 */
2021 int checkOperator(DiagnosticPosition pos,
2022 OperatorSymbol operator,
2023 int tag,
2024 Type left,
2025 Type right) {
2026 if (operator.opcode == ByteCodes.error) {
2027 log.error(pos,
2028 "operator.cant.be.applied",
2029 treeinfo.operatorName(tag),
2030 left + "," + right);
2031 }
2032 return operator.opcode;
2033 }
2036 /**
2037 * Check for division by integer constant zero
2038 * @param pos Position for error reporting.
2039 * @param operator The operator for the expression
2040 * @param operand The right hand operand for the expression
2041 */
2042 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
2043 if (operand.constValue() != null
2044 && lint.isEnabled(Lint.LintCategory.DIVZERO)
2045 && operand.tag <= LONG
2046 && ((Number) (operand.constValue())).longValue() == 0) {
2047 int opc = ((OperatorSymbol)operator).opcode;
2048 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
2049 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
2050 log.warning(pos, "div.zero");
2051 }
2052 }
2053 }
2055 /**
2056 * Check for empty statements after if
2057 */
2058 void checkEmptyIf(JCIf tree) {
2059 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(Lint.LintCategory.EMPTY))
2060 log.warning(tree.thenpart.pos(), "empty.if");
2061 }
2063 /** Check that symbol is unique in given scope.
2064 * @param pos Position for error reporting.
2065 * @param sym The symbol.
2066 * @param s The scope.
2067 */
2068 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2069 if (sym.type.isErroneous())
2070 return true;
2071 if (sym.owner.name == names.any) return false;
2072 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2073 if (sym != e.sym &&
2074 sym.kind == e.sym.kind &&
2075 sym.name != names.error &&
2076 (sym.kind != MTH || types.overrideEquivalent(sym.type, e.sym.type))) {
2077 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS))
2078 varargsDuplicateError(pos, sym, e.sym);
2079 else
2080 duplicateError(pos, e.sym);
2081 return false;
2082 }
2083 }
2084 return true;
2085 }
2087 /** Check that single-type import is not already imported or top-level defined,
2088 * but make an exception for two single-type imports which denote the same type.
2089 * @param pos Position for error reporting.
2090 * @param sym The symbol.
2091 * @param s The scope
2092 */
2093 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2094 return checkUniqueImport(pos, sym, s, false);
2095 }
2097 /** Check that static single-type import is not already imported or top-level defined,
2098 * but make an exception for two single-type imports which denote the same type.
2099 * @param pos Position for error reporting.
2100 * @param sym The symbol.
2101 * @param s The scope
2102 * @param staticImport Whether or not this was a static import
2103 */
2104 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2105 return checkUniqueImport(pos, sym, s, true);
2106 }
2108 /** Check that single-type import is not already imported or top-level defined,
2109 * but make an exception for two single-type imports which denote the same type.
2110 * @param pos Position for error reporting.
2111 * @param sym The symbol.
2112 * @param s The scope.
2113 * @param staticImport Whether or not this was a static import
2114 */
2115 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2116 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2117 // is encountered class entered via a class declaration?
2118 boolean isClassDecl = e.scope == s;
2119 if ((isClassDecl || sym != e.sym) &&
2120 sym.kind == e.sym.kind &&
2121 sym.name != names.error) {
2122 if (!e.sym.type.isErroneous()) {
2123 String what = e.sym.toString();
2124 if (!isClassDecl) {
2125 if (staticImport)
2126 log.error(pos, "already.defined.static.single.import", what);
2127 else
2128 log.error(pos, "already.defined.single.import", what);
2129 }
2130 else if (sym != e.sym)
2131 log.error(pos, "already.defined.this.unit", what);
2132 }
2133 return false;
2134 }
2135 }
2136 return true;
2137 }
2139 /** Check that a qualified name is in canonical form (for import decls).
2140 */
2141 public void checkCanonical(JCTree tree) {
2142 if (!isCanonical(tree))
2143 log.error(tree.pos(), "import.requires.canonical",
2144 TreeInfo.symbol(tree));
2145 }
2146 // where
2147 private boolean isCanonical(JCTree tree) {
2148 while (tree.getTag() == JCTree.SELECT) {
2149 JCFieldAccess s = (JCFieldAccess) tree;
2150 if (s.sym.owner != TreeInfo.symbol(s.selected))
2151 return false;
2152 tree = s.selected;
2153 }
2154 return true;
2155 }
2157 private class ConversionWarner extends Warner {
2158 final String key;
2159 final Type found;
2160 final Type expected;
2161 public ConversionWarner(DiagnosticPosition pos, String key, Type found, Type expected) {
2162 super(pos);
2163 this.key = key;
2164 this.found = found;
2165 this.expected = expected;
2166 }
2168 public void warnUnchecked() {
2169 boolean warned = this.warned;
2170 super.warnUnchecked();
2171 if (warned) return; // suppress redundant diagnostics
2172 Object problem = JCDiagnostic.fragment(key);
2173 Check.this.warnUnchecked(pos(), "prob.found.req", problem, found, expected);
2174 }
2175 }
2177 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2178 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2179 }
2181 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2182 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2183 }
2184 }
