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src/share/classes/com/sun/tools/javac/comp/Check.java@8c55d5b0ed71
src/share/classes/com/sun/tools/javac/comp/Check.java
Mon, 09 Mar 2009 23:53:41 -0700
- author
- tbell
- date
- Mon, 09 Mar 2009 23:53:41 -0700
- changeset 240
- 8c55d5b0ed71
- parent 229
- 03bcd66bd8e7
- parent 236
- 84a18d7da478
- child 252
- 5caa6c45936a
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Merge
1 /*
2 * Copyright 1999-2009 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 Names 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 JCDiagnostic.Factory diags;
67 private final boolean skipAnnotations;
68 private final TreeInfo treeinfo;
70 // The set of lint options currently in effect. It is initialized
71 // from the context, and then is set/reset as needed by Attr as it
72 // visits all the various parts of the trees during attribution.
73 private Lint lint;
75 public static Check instance(Context context) {
76 Check instance = context.get(checkKey);
77 if (instance == null)
78 instance = new Check(context);
79 return instance;
80 }
82 protected Check(Context context) {
83 context.put(checkKey, this);
85 names = Names.instance(context);
86 log = Log.instance(context);
87 syms = Symtab.instance(context);
88 infer = Infer.instance(context);
89 this.types = Types.instance(context);
90 diags = JCDiagnostic.Factory.instance(context);
91 Options options = Options.instance(context);
92 target = Target.instance(context);
93 source = Source.instance(context);
94 lint = Lint.instance(context);
95 treeinfo = TreeInfo.instance(context);
97 Source source = Source.instance(context);
98 allowGenerics = source.allowGenerics();
99 allowAnnotations = source.allowAnnotations();
100 complexInference = options.get("-complexinference") != null;
101 skipAnnotations = options.get("skipAnnotations") != null;
103 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
104 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
105 boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
107 deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
108 enforceMandatoryWarnings, "deprecated");
109 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
110 enforceMandatoryWarnings, "unchecked");
111 }
113 /** Switch: generics enabled?
114 */
115 boolean allowGenerics;
117 /** Switch: annotations enabled?
118 */
119 boolean allowAnnotations;
121 /** Switch: -complexinference option set?
122 */
123 boolean complexInference;
125 /** A table mapping flat names of all compiled classes in this run to their
126 * symbols; maintained from outside.
127 */
128 public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
130 /** A handler for messages about deprecated usage.
131 */
132 private MandatoryWarningHandler deprecationHandler;
134 /** A handler for messages about unchecked or unsafe usage.
135 */
136 private MandatoryWarningHandler uncheckedHandler;
139 /* *************************************************************************
140 * Errors and Warnings
141 **************************************************************************/
143 Lint setLint(Lint newLint) {
144 Lint prev = lint;
145 lint = newLint;
146 return prev;
147 }
149 /** Warn about deprecated symbol.
150 * @param pos Position to be used for error reporting.
151 * @param sym The deprecated symbol.
152 */
153 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
154 if (!lint.isSuppressed(LintCategory.DEPRECATION))
155 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
156 }
158 /** Warn about unchecked operation.
159 * @param pos Position to be used for error reporting.
160 * @param msg A string describing the problem.
161 */
162 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
163 if (!lint.isSuppressed(LintCategory.UNCHECKED))
164 uncheckedHandler.report(pos, msg, args);
165 }
167 /**
168 * Report any deferred diagnostics.
169 */
170 public void reportDeferredDiagnostics() {
171 deprecationHandler.reportDeferredDiagnostic();
172 uncheckedHandler.reportDeferredDiagnostic();
173 }
176 /** Report a failure to complete a class.
177 * @param pos Position to be used for error reporting.
178 * @param ex The failure to report.
179 */
180 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
181 log.error(pos, "cant.access", ex.sym, ex.getDetailValue());
182 if (ex instanceof ClassReader.BadClassFile) throw new Abort();
183 else return syms.errType;
184 }
186 /** Report a type error.
187 * @param pos Position to be used for error reporting.
188 * @param problem A string describing the error.
189 * @param found The type that was found.
190 * @param req The type that was required.
191 */
192 Type typeError(DiagnosticPosition pos, Object problem, Type found, Type req) {
193 log.error(pos, "prob.found.req",
194 problem, found, req);
195 return types.createErrorType(found);
196 }
198 Type typeError(DiagnosticPosition pos, String problem, Type found, Type req, Object explanation) {
199 log.error(pos, "prob.found.req.1", problem, found, req, explanation);
200 return types.createErrorType(found);
201 }
203 /** Report an error that wrong type tag was found.
204 * @param pos Position to be used for error reporting.
205 * @param required An internationalized string describing the type tag
206 * required.
207 * @param found The type that was found.
208 */
209 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
210 log.error(pos, "type.found.req", found, required);
211 return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
212 }
214 /** Report an error that symbol cannot be referenced before super
215 * has been called.
216 * @param pos Position to be used for error reporting.
217 * @param sym The referenced symbol.
218 */
219 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
220 log.error(pos, "cant.ref.before.ctor.called", sym);
221 }
223 /** Report duplicate declaration error.
224 */
225 void duplicateError(DiagnosticPosition pos, Symbol sym) {
226 if (!sym.type.isErroneous()) {
227 log.error(pos, "already.defined", sym, sym.location());
228 }
229 }
231 /** Report array/varargs duplicate declaration
232 */
233 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
234 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
235 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
236 }
237 }
239 /* ************************************************************************
240 * duplicate declaration checking
241 *************************************************************************/
243 /** Check that variable does not hide variable with same name in
244 * immediately enclosing local scope.
245 * @param pos Position for error reporting.
246 * @param v The symbol.
247 * @param s The scope.
248 */
249 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
250 if (s.next != null) {
251 for (Scope.Entry e = s.next.lookup(v.name);
252 e.scope != null && e.sym.owner == v.owner;
253 e = e.next()) {
254 if (e.sym.kind == VAR &&
255 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
256 v.name != names.error) {
257 duplicateError(pos, e.sym);
258 return;
259 }
260 }
261 }
262 }
264 /** Check that a class or interface does not hide a class or
265 * interface with same name in immediately enclosing local scope.
266 * @param pos Position for error reporting.
267 * @param c The symbol.
268 * @param s The scope.
269 */
270 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
271 if (s.next != null) {
272 for (Scope.Entry e = s.next.lookup(c.name);
273 e.scope != null && e.sym.owner == c.owner;
274 e = e.next()) {
275 if (e.sym.kind == TYP &&
276 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
277 c.name != names.error) {
278 duplicateError(pos, e.sym);
279 return;
280 }
281 }
282 }
283 }
285 /** Check that class does not have the same name as one of
286 * its enclosing classes, or as a class defined in its enclosing scope.
287 * return true if class is unique in its enclosing scope.
288 * @param pos Position for error reporting.
289 * @param name The class name.
290 * @param s The enclosing scope.
291 */
292 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
293 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
294 if (e.sym.kind == TYP && e.sym.name != names.error) {
295 duplicateError(pos, e.sym);
296 return false;
297 }
298 }
299 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
300 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
301 duplicateError(pos, sym);
302 return true;
303 }
304 }
305 return true;
306 }
308 /* *************************************************************************
309 * Class name generation
310 **************************************************************************/
312 /** Return name of local class.
313 * This is of the form <enclClass> $ n <classname>
314 * where
315 * enclClass is the flat name of the enclosing class,
316 * classname is the simple name of the local class
317 */
318 Name localClassName(ClassSymbol c) {
319 for (int i=1; ; i++) {
320 Name flatname = names.
321 fromString("" + c.owner.enclClass().flatname +
322 target.syntheticNameChar() + i +
323 c.name);
324 if (compiled.get(flatname) == null) return flatname;
325 }
326 }
328 /* *************************************************************************
329 * Type Checking
330 **************************************************************************/
332 /** Check that a given type is assignable to a given proto-type.
333 * If it is, return the type, otherwise return errType.
334 * @param pos Position to be used for error reporting.
335 * @param found The type that was found.
336 * @param req The type that was required.
337 */
338 Type checkType(DiagnosticPosition pos, Type found, Type req) {
339 if (req.tag == ERROR)
340 return req;
341 if (found.tag == FORALL)
342 return instantiatePoly(pos, (ForAll)found, req, convertWarner(pos, found, req));
343 if (req.tag == NONE)
344 return found;
345 if (types.isAssignable(found, req, convertWarner(pos, found, req)))
346 return found;
347 if (found.tag <= DOUBLE && req.tag <= DOUBLE)
348 return typeError(pos, diags.fragment("possible.loss.of.precision"), found, req);
349 if (found.isSuperBound()) {
350 log.error(pos, "assignment.from.super-bound", found);
351 return types.createErrorType(found);
352 }
353 if (req.isExtendsBound()) {
354 log.error(pos, "assignment.to.extends-bound", req);
355 return types.createErrorType(found);
356 }
357 return typeError(pos, diags.fragment("incompatible.types"), found, req);
358 }
360 /** Instantiate polymorphic type to some prototype, unless
361 * prototype is `anyPoly' in which case polymorphic type
362 * is returned unchanged.
363 */
364 Type instantiatePoly(DiagnosticPosition pos, ForAll t, Type pt, Warner warn) {
365 if (pt == Infer.anyPoly && complexInference) {
366 return t;
367 } else if (pt == Infer.anyPoly || pt.tag == NONE) {
368 Type newpt = t.qtype.tag <= VOID ? t.qtype : syms.objectType;
369 return instantiatePoly(pos, t, newpt, warn);
370 } else if (pt.tag == ERROR) {
371 return pt;
372 } else {
373 try {
374 return infer.instantiateExpr(t, pt, warn);
375 } catch (Infer.NoInstanceException ex) {
376 if (ex.isAmbiguous) {
377 JCDiagnostic d = ex.getDiagnostic();
378 log.error(pos,
379 "undetermined.type" + (d!=null ? ".1" : ""),
380 t, d);
381 return types.createErrorType(pt);
382 } else {
383 JCDiagnostic d = ex.getDiagnostic();
384 return typeError(pos,
385 diags.fragment("incompatible.types" + (d!=null ? ".1" : ""), d),
386 t, pt);
387 }
388 }
389 }
390 }
392 /** Check that a given type can be cast to a given target type.
393 * Return the result of the cast.
394 * @param pos Position to be used for error reporting.
395 * @param found The type that is being cast.
396 * @param req The target type of the cast.
397 */
398 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
399 if (found.tag == FORALL) {
400 instantiatePoly(pos, (ForAll) found, req, castWarner(pos, found, req));
401 return req;
402 } else if (types.isCastable(found, req, castWarner(pos, found, req))) {
403 return req;
404 } else {
405 return typeError(pos,
406 diags.fragment("inconvertible.types"),
407 found, req);
408 }
409 }
410 //where
411 /** Is type a type variable, or a (possibly multi-dimensional) array of
412 * type variables?
413 */
414 boolean isTypeVar(Type t) {
415 return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
416 }
418 /** Check that a type is within some bounds.
419 *
420 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
421 * type argument.
422 * @param pos Position to be used for error reporting.
423 * @param a The type that should be bounded by bs.
424 * @param bs The bound.
425 */
426 private void checkExtends(DiagnosticPosition pos, Type a, TypeVar bs) {
427 if (a.isUnbound()) {
428 return;
429 } else if (a.tag != WILDCARD) {
430 a = types.upperBound(a);
431 for (List<Type> l = types.getBounds(bs); l.nonEmpty(); l = l.tail) {
432 if (!types.isSubtype(a, l.head)) {
433 log.error(pos, "not.within.bounds", a);
434 return;
435 }
436 }
437 } else if (a.isExtendsBound()) {
438 if (!types.isCastable(bs.getUpperBound(), types.upperBound(a), Warner.noWarnings))
439 log.error(pos, "not.within.bounds", a);
440 } else if (a.isSuperBound()) {
441 if (types.notSoftSubtype(types.lowerBound(a), bs.getUpperBound()))
442 log.error(pos, "not.within.bounds", a);
443 }
444 }
446 /** Check that a type is within some bounds.
447 *
448 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
449 * type argument.
450 * @param pos Position to be used for error reporting.
451 * @param a The type that should be bounded by bs.
452 * @param bs The bound.
453 */
454 private void checkCapture(JCTypeApply tree) {
455 List<JCExpression> args = tree.getTypeArguments();
456 for (Type arg : types.capture(tree.type).getTypeArguments()) {
457 if (arg.tag == TYPEVAR && arg.getUpperBound().isErroneous()) {
458 log.error(args.head.pos, "not.within.bounds", args.head.type);
459 break;
460 }
461 args = args.tail;
462 }
463 }
465 /** Check that type is different from 'void'.
466 * @param pos Position to be used for error reporting.
467 * @param t The type to be checked.
468 */
469 Type checkNonVoid(DiagnosticPosition pos, Type t) {
470 if (t.tag == VOID) {
471 log.error(pos, "void.not.allowed.here");
472 return types.createErrorType(t);
473 } else {
474 return t;
475 }
476 }
478 /** Check that type is a class or interface type.
479 * @param pos Position to be used for error reporting.
480 * @param t The type to be checked.
481 */
482 Type checkClassType(DiagnosticPosition pos, Type t) {
483 if (t.tag != CLASS && t.tag != ERROR)
484 return typeTagError(pos,
485 diags.fragment("type.req.class"),
486 (t.tag == TYPEVAR)
487 ? diags.fragment("type.parameter", t)
488 : t);
489 else
490 return t;
491 }
493 /** Check that type is a class or interface type.
494 * @param pos Position to be used for error reporting.
495 * @param t The type to be checked.
496 * @param noBounds True if type bounds are illegal here.
497 */
498 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
499 t = checkClassType(pos, t);
500 if (noBounds && t.isParameterized()) {
501 List<Type> args = t.getTypeArguments();
502 while (args.nonEmpty()) {
503 if (args.head.tag == WILDCARD)
504 return typeTagError(pos,
505 log.getLocalizedString("type.req.exact"),
506 args.head);
507 args = args.tail;
508 }
509 }
510 return t;
511 }
513 /** Check that type is a reifiable class, interface or array type.
514 * @param pos Position to be used for error reporting.
515 * @param t The type to be checked.
516 */
517 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
518 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
519 return typeTagError(pos,
520 diags.fragment("type.req.class.array"),
521 t);
522 } else if (!types.isReifiable(t)) {
523 log.error(pos, "illegal.generic.type.for.instof");
524 return types.createErrorType(t);
525 } else {
526 return t;
527 }
528 }
530 /** Check that type is a reference type, i.e. a class, interface or array type
531 * or a type variable.
532 * @param pos Position to be used for error reporting.
533 * @param t The type to be checked.
534 */
535 Type checkRefType(DiagnosticPosition pos, Type t) {
536 switch (t.tag) {
537 case CLASS:
538 case ARRAY:
539 case TYPEVAR:
540 case WILDCARD:
541 case ERROR:
542 return t;
543 default:
544 return typeTagError(pos,
545 diags.fragment("type.req.ref"),
546 t);
547 }
548 }
550 /** Check that type is a null or reference type.
551 * @param pos Position to be used for error reporting.
552 * @param t The type to be checked.
553 */
554 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
555 switch (t.tag) {
556 case CLASS:
557 case ARRAY:
558 case TYPEVAR:
559 case WILDCARD:
560 case BOT:
561 case ERROR:
562 return t;
563 default:
564 return typeTagError(pos,
565 diags.fragment("type.req.ref"),
566 t);
567 }
568 }
570 /** Check that flag set does not contain elements of two conflicting sets. s
571 * Return true if it doesn't.
572 * @param pos Position to be used for error reporting.
573 * @param flags The set of flags to be checked.
574 * @param set1 Conflicting flags set #1.
575 * @param set2 Conflicting flags set #2.
576 */
577 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
578 if ((flags & set1) != 0 && (flags & set2) != 0) {
579 log.error(pos,
580 "illegal.combination.of.modifiers",
581 asFlagSet(TreeInfo.firstFlag(flags & set1)),
582 asFlagSet(TreeInfo.firstFlag(flags & set2)));
583 return false;
584 } else
585 return true;
586 }
588 /** Check that given modifiers are legal for given symbol and
589 * return modifiers together with any implicit modififiers for that symbol.
590 * Warning: we can't use flags() here since this method
591 * is called during class enter, when flags() would cause a premature
592 * completion.
593 * @param pos Position to be used for error reporting.
594 * @param flags The set of modifiers given in a definition.
595 * @param sym The defined symbol.
596 */
597 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
598 long mask;
599 long implicit = 0;
600 switch (sym.kind) {
601 case VAR:
602 if (sym.owner.kind != TYP)
603 mask = LocalVarFlags;
604 else if ((sym.owner.flags_field & INTERFACE) != 0)
605 mask = implicit = InterfaceVarFlags;
606 else
607 mask = VarFlags;
608 break;
609 case MTH:
610 if (sym.name == names.init) {
611 if ((sym.owner.flags_field & ENUM) != 0) {
612 // enum constructors cannot be declared public or
613 // protected and must be implicitly or explicitly
614 // private
615 implicit = PRIVATE;
616 mask = PRIVATE;
617 } else
618 mask = ConstructorFlags;
619 } else if ((sym.owner.flags_field & INTERFACE) != 0)
620 mask = implicit = InterfaceMethodFlags;
621 else {
622 mask = MethodFlags;
623 }
624 // Imply STRICTFP if owner has STRICTFP set.
625 if (((flags|implicit) & Flags.ABSTRACT) == 0)
626 implicit |= sym.owner.flags_field & STRICTFP;
627 break;
628 case TYP:
629 if (sym.isLocal()) {
630 mask = LocalClassFlags;
631 if (sym.name.isEmpty()) { // Anonymous class
632 // Anonymous classes in static methods are themselves static;
633 // that's why we admit STATIC here.
634 mask |= STATIC;
635 // JLS: Anonymous classes are final.
636 implicit |= FINAL;
637 }
638 if ((sym.owner.flags_field & STATIC) == 0 &&
639 (flags & ENUM) != 0)
640 log.error(pos, "enums.must.be.static");
641 } else if (sym.owner.kind == TYP) {
642 mask = MemberClassFlags;
643 if (sym.owner.owner.kind == PCK ||
644 (sym.owner.flags_field & STATIC) != 0)
645 mask |= STATIC;
646 else if ((flags & ENUM) != 0)
647 log.error(pos, "enums.must.be.static");
648 // Nested interfaces and enums are always STATIC (Spec ???)
649 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
650 } else {
651 mask = ClassFlags;
652 }
653 // Interfaces are always ABSTRACT
654 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
656 if ((flags & ENUM) != 0) {
657 // enums can't be declared abstract or final
658 mask &= ~(ABSTRACT | FINAL);
659 implicit |= implicitEnumFinalFlag(tree);
660 }
661 // Imply STRICTFP if owner has STRICTFP set.
662 implicit |= sym.owner.flags_field & STRICTFP;
663 break;
664 default:
665 throw new AssertionError();
666 }
667 long illegal = flags & StandardFlags & ~mask;
668 if (illegal != 0) {
669 if ((illegal & INTERFACE) != 0) {
670 log.error(pos, "intf.not.allowed.here");
671 mask |= INTERFACE;
672 }
673 else {
674 log.error(pos,
675 "mod.not.allowed.here", asFlagSet(illegal));
676 }
677 }
678 else if ((sym.kind == TYP ||
679 // ISSUE: Disallowing abstract&private is no longer appropriate
680 // in the presence of inner classes. Should it be deleted here?
681 checkDisjoint(pos, flags,
682 ABSTRACT,
683 PRIVATE | STATIC))
684 &&
685 checkDisjoint(pos, flags,
686 ABSTRACT | INTERFACE,
687 FINAL | NATIVE | SYNCHRONIZED)
688 &&
689 checkDisjoint(pos, flags,
690 PUBLIC,
691 PRIVATE | PROTECTED)
692 &&
693 checkDisjoint(pos, flags,
694 PRIVATE,
695 PUBLIC | PROTECTED)
696 &&
697 checkDisjoint(pos, flags,
698 FINAL,
699 VOLATILE)
700 &&
701 (sym.kind == TYP ||
702 checkDisjoint(pos, flags,
703 ABSTRACT | NATIVE,
704 STRICTFP))) {
705 // skip
706 }
707 return flags & (mask | ~StandardFlags) | implicit;
708 }
711 /** Determine if this enum should be implicitly final.
712 *
713 * If the enum has no specialized enum contants, it is final.
714 *
715 * If the enum does have specialized enum contants, it is
716 * <i>not</i> final.
717 */
718 private long implicitEnumFinalFlag(JCTree tree) {
719 if (tree.getTag() != JCTree.CLASSDEF) return 0;
720 class SpecialTreeVisitor extends JCTree.Visitor {
721 boolean specialized;
722 SpecialTreeVisitor() {
723 this.specialized = false;
724 };
726 public void visitTree(JCTree tree) { /* no-op */ }
728 public void visitVarDef(JCVariableDecl tree) {
729 if ((tree.mods.flags & ENUM) != 0) {
730 if (tree.init instanceof JCNewClass &&
731 ((JCNewClass) tree.init).def != null) {
732 specialized = true;
733 }
734 }
735 }
736 }
738 SpecialTreeVisitor sts = new SpecialTreeVisitor();
739 JCClassDecl cdef = (JCClassDecl) tree;
740 for (JCTree defs: cdef.defs) {
741 defs.accept(sts);
742 if (sts.specialized) return 0;
743 }
744 return FINAL;
745 }
747 /* *************************************************************************
748 * Type Validation
749 **************************************************************************/
751 /** Validate a type expression. That is,
752 * check that all type arguments of a parametric type are within
753 * their bounds. This must be done in a second phase after type attributon
754 * since a class might have a subclass as type parameter bound. E.g:
755 *
756 * class B<A extends C> { ... }
757 * class C extends B<C> { ... }
758 *
759 * and we can't make sure that the bound is already attributed because
760 * of possible cycles.
761 */
762 private Validator validator = new Validator();
764 /** Visitor method: Validate a type expression, if it is not null, catching
765 * and reporting any completion failures.
766 */
767 void validate(JCTree tree, Env<AttrContext> env) {
768 try {
769 if (tree != null) {
770 validator.env = env;
771 tree.accept(validator);
772 checkRaw(tree, env);
773 }
774 } catch (CompletionFailure ex) {
775 completionError(tree.pos(), ex);
776 }
777 }
778 //where
779 void checkRaw(JCTree tree, Env<AttrContext> env) {
780 if (lint.isEnabled(Lint.LintCategory.RAW) &&
781 tree.type.tag == CLASS &&
782 !env.enclClass.name.isEmpty() && //anonymous or intersection
783 tree.type.isRaw()) {
784 log.warning(tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
785 }
786 }
788 /** Visitor method: Validate a list of type expressions.
789 */
790 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
791 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
792 validate(l.head, env);
793 }
795 /** A visitor class for type validation.
796 */
797 class Validator extends JCTree.Visitor {
799 public void visitTypeArray(JCArrayTypeTree tree) {
800 validate(tree.elemtype, env);
801 }
803 public void visitTypeApply(JCTypeApply tree) {
804 if (tree.type.tag == CLASS) {
805 List<Type> formals = tree.type.tsym.type.allparams();
806 List<Type> actuals = tree.type.allparams();
807 List<JCExpression> args = tree.arguments;
808 List<Type> forms = tree.type.tsym.type.getTypeArguments();
809 ListBuffer<TypeVar> tvars_buf = new ListBuffer<TypeVar>();
811 // For matching pairs of actual argument types `a' and
812 // formal type parameters with declared bound `b' ...
813 while (args.nonEmpty() && forms.nonEmpty()) {
814 validate(args.head, env);
816 // exact type arguments needs to know their
817 // bounds (for upper and lower bound
818 // calculations). So we create new TypeVars with
819 // bounds substed with actuals.
820 tvars_buf.append(types.substBound(((TypeVar)forms.head),
821 formals,
822 actuals));
824 args = args.tail;
825 forms = forms.tail;
826 }
828 args = tree.arguments;
829 List<Type> tvars_cap = types.substBounds(formals,
830 formals,
831 types.capture(tree.type).allparams());
832 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
833 // Let the actual arguments know their bound
834 args.head.type.withTypeVar((TypeVar)tvars_cap.head);
835 args = args.tail;
836 tvars_cap = tvars_cap.tail;
837 }
839 args = tree.arguments;
840 List<TypeVar> tvars = tvars_buf.toList();
842 while (args.nonEmpty() && tvars.nonEmpty()) {
843 checkExtends(args.head.pos(),
844 args.head.type,
845 tvars.head);
846 args = args.tail;
847 tvars = tvars.tail;
848 }
850 checkCapture(tree);
852 // Check that this type is either fully parameterized, or
853 // not parameterized at all.
854 if (tree.type.getEnclosingType().isRaw())
855 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
856 if (tree.clazz.getTag() == JCTree.SELECT)
857 visitSelectInternal((JCFieldAccess)tree.clazz);
858 }
859 }
861 public void visitTypeParameter(JCTypeParameter tree) {
862 validate(tree.bounds, env);
863 checkClassBounds(tree.pos(), tree.type);
864 }
866 @Override
867 public void visitWildcard(JCWildcard tree) {
868 if (tree.inner != null)
869 validate(tree.inner, env);
870 }
872 public void visitSelect(JCFieldAccess tree) {
873 if (tree.type.tag == CLASS) {
874 visitSelectInternal(tree);
876 // Check that this type is either fully parameterized, or
877 // not parameterized at all.
878 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
879 log.error(tree.pos(), "improperly.formed.type.param.missing");
880 }
881 }
882 public void visitSelectInternal(JCFieldAccess tree) {
883 if (tree.type.tsym.isStatic() &&
884 tree.selected.type.isParameterized()) {
885 // The enclosing type is not a class, so we are
886 // looking at a static member type. However, the
887 // qualifying expression is parameterized.
888 log.error(tree.pos(), "cant.select.static.class.from.param.type");
889 } else {
890 // otherwise validate the rest of the expression
891 tree.selected.accept(this);
892 }
893 }
895 /** Default visitor method: do nothing.
896 */
897 public void visitTree(JCTree tree) {
898 }
900 Env<AttrContext> env;
901 }
903 /* *************************************************************************
904 * Exception checking
905 **************************************************************************/
907 /* The following methods treat classes as sets that contain
908 * the class itself and all their subclasses
909 */
911 /** Is given type a subtype of some of the types in given list?
912 */
913 boolean subset(Type t, List<Type> ts) {
914 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
915 if (types.isSubtype(t, l.head)) return true;
916 return false;
917 }
919 /** Is given type a subtype or supertype of
920 * some of the types in given list?
921 */
922 boolean intersects(Type t, List<Type> ts) {
923 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
924 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
925 return false;
926 }
928 /** Add type set to given type list, unless it is a subclass of some class
929 * in the list.
930 */
931 List<Type> incl(Type t, List<Type> ts) {
932 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
933 }
935 /** Remove type set from type set list.
936 */
937 List<Type> excl(Type t, List<Type> ts) {
938 if (ts.isEmpty()) {
939 return ts;
940 } else {
941 List<Type> ts1 = excl(t, ts.tail);
942 if (types.isSubtype(ts.head, t)) return ts1;
943 else if (ts1 == ts.tail) return ts;
944 else return ts1.prepend(ts.head);
945 }
946 }
948 /** Form the union of two type set lists.
949 */
950 List<Type> union(List<Type> ts1, List<Type> ts2) {
951 List<Type> ts = ts1;
952 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
953 ts = incl(l.head, ts);
954 return ts;
955 }
957 /** Form the difference of two type lists.
958 */
959 List<Type> diff(List<Type> ts1, List<Type> ts2) {
960 List<Type> ts = ts1;
961 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
962 ts = excl(l.head, ts);
963 return ts;
964 }
966 /** Form the intersection of two type lists.
967 */
968 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
969 List<Type> ts = List.nil();
970 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
971 if (subset(l.head, ts2)) ts = incl(l.head, ts);
972 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
973 if (subset(l.head, ts1)) ts = incl(l.head, ts);
974 return ts;
975 }
977 /** Is exc an exception symbol that need not be declared?
978 */
979 boolean isUnchecked(ClassSymbol exc) {
980 return
981 exc.kind == ERR ||
982 exc.isSubClass(syms.errorType.tsym, types) ||
983 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
984 }
986 /** Is exc an exception type that need not be declared?
987 */
988 boolean isUnchecked(Type exc) {
989 return
990 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
991 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
992 exc.tag == BOT;
993 }
995 /** Same, but handling completion failures.
996 */
997 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
998 try {
999 return isUnchecked(exc);
1000 } catch (CompletionFailure ex) {
1001 completionError(pos, ex);
1002 return true;
1003 }
1004 }
1006 /** Is exc handled by given exception list?
1007 */
1008 boolean isHandled(Type exc, List<Type> handled) {
1009 return isUnchecked(exc) || subset(exc, handled);
1010 }
1012 /** Return all exceptions in thrown list that are not in handled list.
1013 * @param thrown The list of thrown exceptions.
1014 * @param handled The list of handled exceptions.
1015 */
1016 List<Type> unHandled(List<Type> thrown, List<Type> handled) {
1017 List<Type> unhandled = List.nil();
1018 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1019 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1020 return unhandled;
1021 }
1023 /* *************************************************************************
1024 * Overriding/Implementation checking
1025 **************************************************************************/
1027 /** The level of access protection given by a flag set,
1028 * where PRIVATE is highest and PUBLIC is lowest.
1029 */
1030 static int protection(long flags) {
1031 switch ((short)(flags & AccessFlags)) {
1032 case PRIVATE: return 3;
1033 case PROTECTED: return 1;
1034 default:
1035 case PUBLIC: return 0;
1036 case 0: return 2;
1037 }
1038 }
1040 /** A customized "cannot override" error message.
1041 * @param m The overriding method.
1042 * @param other The overridden method.
1043 * @return An internationalized string.
1044 */
1045 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1046 String key;
1047 if ((other.owner.flags() & INTERFACE) == 0)
1048 key = "cant.override";
1049 else if ((m.owner.flags() & INTERFACE) == 0)
1050 key = "cant.implement";
1051 else
1052 key = "clashes.with";
1053 return diags.fragment(key, m, m.location(), other, other.location());
1054 }
1056 /** A customized "override" warning message.
1057 * @param m The overriding method.
1058 * @param other The overridden method.
1059 * @return An internationalized string.
1060 */
1061 Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1062 String key;
1063 if ((other.owner.flags() & INTERFACE) == 0)
1064 key = "unchecked.override";
1065 else if ((m.owner.flags() & INTERFACE) == 0)
1066 key = "unchecked.implement";
1067 else
1068 key = "unchecked.clash.with";
1069 return diags.fragment(key, m, m.location(), other, other.location());
1070 }
1072 /** A customized "override" warning message.
1073 * @param m The overriding method.
1074 * @param other The overridden method.
1075 * @return An internationalized string.
1076 */
1077 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1078 String key;
1079 if ((other.owner.flags() & INTERFACE) == 0)
1080 key = "varargs.override";
1081 else if ((m.owner.flags() & INTERFACE) == 0)
1082 key = "varargs.implement";
1083 else
1084 key = "varargs.clash.with";
1085 return diags.fragment(key, m, m.location(), other, other.location());
1086 }
1088 /** Check that this method conforms with overridden method 'other'.
1089 * where `origin' is the class where checking started.
1090 * Complications:
1091 * (1) Do not check overriding of synthetic methods
1092 * (reason: they might be final).
1093 * todo: check whether this is still necessary.
1094 * (2) Admit the case where an interface proxy throws fewer exceptions
1095 * than the method it implements. Augment the proxy methods with the
1096 * undeclared exceptions in this case.
1097 * (3) When generics are enabled, admit the case where an interface proxy
1098 * has a result type
1099 * extended by the result type of the method it implements.
1100 * Change the proxies result type to the smaller type in this case.
1101 *
1102 * @param tree The tree from which positions
1103 * are extracted for errors.
1104 * @param m The overriding method.
1105 * @param other The overridden method.
1106 * @param origin The class of which the overriding method
1107 * is a member.
1108 */
1109 void checkOverride(JCTree tree,
1110 MethodSymbol m,
1111 MethodSymbol other,
1112 ClassSymbol origin) {
1113 // Don't check overriding of synthetic methods or by bridge methods.
1114 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1115 return;
1116 }
1118 // Error if static method overrides instance method (JLS 8.4.6.2).
1119 if ((m.flags() & STATIC) != 0 &&
1120 (other.flags() & STATIC) == 0) {
1121 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1122 cannotOverride(m, other));
1123 return;
1124 }
1126 // Error if instance method overrides static or final
1127 // method (JLS 8.4.6.1).
1128 if ((other.flags() & FINAL) != 0 ||
1129 (m.flags() & STATIC) == 0 &&
1130 (other.flags() & STATIC) != 0) {
1131 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1132 cannotOverride(m, other),
1133 asFlagSet(other.flags() & (FINAL | STATIC)));
1134 return;
1135 }
1137 if ((m.owner.flags() & ANNOTATION) != 0) {
1138 // handled in validateAnnotationMethod
1139 return;
1140 }
1142 // Error if overriding method has weaker access (JLS 8.4.6.3).
1143 if ((origin.flags() & INTERFACE) == 0 &&
1144 protection(m.flags()) > protection(other.flags())) {
1145 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1146 cannotOverride(m, other),
1147 other.flags() == 0 ?
1148 Flag.PACKAGE :
1149 asFlagSet(other.flags() & AccessFlags));
1150 return;
1151 }
1153 Type mt = types.memberType(origin.type, m);
1154 Type ot = types.memberType(origin.type, other);
1155 // Error if overriding result type is different
1156 // (or, in the case of generics mode, not a subtype) of
1157 // overridden result type. We have to rename any type parameters
1158 // before comparing types.
1159 List<Type> mtvars = mt.getTypeArguments();
1160 List<Type> otvars = ot.getTypeArguments();
1161 Type mtres = mt.getReturnType();
1162 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1164 overrideWarner.warned = false;
1165 boolean resultTypesOK =
1166 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1167 if (!resultTypesOK) {
1168 if (!source.allowCovariantReturns() &&
1169 m.owner != origin &&
1170 m.owner.isSubClass(other.owner, types)) {
1171 // allow limited interoperability with covariant returns
1172 } else {
1173 typeError(TreeInfo.diagnosticPositionFor(m, tree),
1174 diags.fragment("override.incompatible.ret",
1175 cannotOverride(m, other)),
1176 mtres, otres);
1177 return;
1178 }
1179 } else if (overrideWarner.warned) {
1180 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1181 "prob.found.req",
1182 diags.fragment("override.unchecked.ret",
1183 uncheckedOverrides(m, other)),
1184 mtres, otres);
1185 }
1187 // Error if overriding method throws an exception not reported
1188 // by overridden method.
1189 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1190 List<Type> unhandled = unHandled(mt.getThrownTypes(), otthrown);
1191 if (unhandled.nonEmpty()) {
1192 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1193 "override.meth.doesnt.throw",
1194 cannotOverride(m, other),
1195 unhandled.head);
1196 return;
1197 }
1199 // Optional warning if varargs don't agree
1200 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1201 && lint.isEnabled(Lint.LintCategory.OVERRIDES)) {
1202 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1203 ((m.flags() & Flags.VARARGS) != 0)
1204 ? "override.varargs.missing"
1205 : "override.varargs.extra",
1206 varargsOverrides(m, other));
1207 }
1209 // Warn if instance method overrides bridge method (compiler spec ??)
1210 if ((other.flags() & BRIDGE) != 0) {
1211 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1212 uncheckedOverrides(m, other));
1213 }
1215 // Warn if a deprecated method overridden by a non-deprecated one.
1216 if ((other.flags() & DEPRECATED) != 0
1217 && (m.flags() & DEPRECATED) == 0
1218 && m.outermostClass() != other.outermostClass()
1219 && !isDeprecatedOverrideIgnorable(other, origin)) {
1220 warnDeprecated(TreeInfo.diagnosticPositionFor(m, tree), other);
1221 }
1222 }
1223 // where
1224 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1225 // If the method, m, is defined in an interface, then ignore the issue if the method
1226 // is only inherited via a supertype and also implemented in the supertype,
1227 // because in that case, we will rediscover the issue when examining the method
1228 // in the supertype.
1229 // If the method, m, is not defined in an interface, then the only time we need to
1230 // address the issue is when the method is the supertype implemementation: any other
1231 // case, we will have dealt with when examining the supertype classes
1232 ClassSymbol mc = m.enclClass();
1233 Type st = types.supertype(origin.type);
1234 if (st.tag != CLASS)
1235 return true;
1236 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1238 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1239 List<Type> intfs = types.interfaces(origin.type);
1240 return (intfs.contains(mc.type) ? false : (stimpl != null));
1241 }
1242 else
1243 return (stimpl != m);
1244 }
1247 // used to check if there were any unchecked conversions
1248 Warner overrideWarner = new Warner();
1250 /** Check that a class does not inherit two concrete methods
1251 * with the same signature.
1252 * @param pos Position to be used for error reporting.
1253 * @param site The class type to be checked.
1254 */
1255 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1256 Type sup = types.supertype(site);
1257 if (sup.tag != CLASS) return;
1259 for (Type t1 = sup;
1260 t1.tsym.type.isParameterized();
1261 t1 = types.supertype(t1)) {
1262 for (Scope.Entry e1 = t1.tsym.members().elems;
1263 e1 != null;
1264 e1 = e1.sibling) {
1265 Symbol s1 = e1.sym;
1266 if (s1.kind != MTH ||
1267 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1268 !s1.isInheritedIn(site.tsym, types) ||
1269 ((MethodSymbol)s1).implementation(site.tsym,
1270 types,
1271 true) != s1)
1272 continue;
1273 Type st1 = types.memberType(t1, s1);
1274 int s1ArgsLength = st1.getParameterTypes().length();
1275 if (st1 == s1.type) continue;
1277 for (Type t2 = sup;
1278 t2.tag == CLASS;
1279 t2 = types.supertype(t2)) {
1280 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1281 e2.scope != null;
1282 e2 = e2.next()) {
1283 Symbol s2 = e2.sym;
1284 if (s2 == s1 ||
1285 s2.kind != MTH ||
1286 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1287 s2.type.getParameterTypes().length() != s1ArgsLength ||
1288 !s2.isInheritedIn(site.tsym, types) ||
1289 ((MethodSymbol)s2).implementation(site.tsym,
1290 types,
1291 true) != s2)
1292 continue;
1293 Type st2 = types.memberType(t2, s2);
1294 if (types.overrideEquivalent(st1, st2))
1295 log.error(pos, "concrete.inheritance.conflict",
1296 s1, t1, s2, t2, sup);
1297 }
1298 }
1299 }
1300 }
1301 }
1303 /** Check that classes (or interfaces) do not each define an abstract
1304 * method with same name and arguments but incompatible return types.
1305 * @param pos Position to be used for error reporting.
1306 * @param t1 The first argument type.
1307 * @param t2 The second argument type.
1308 */
1309 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1310 Type t1,
1311 Type t2) {
1312 return checkCompatibleAbstracts(pos, t1, t2,
1313 types.makeCompoundType(t1, t2));
1314 }
1316 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1317 Type t1,
1318 Type t2,
1319 Type site) {
1320 Symbol sym = firstIncompatibility(t1, t2, site);
1321 if (sym != null) {
1322 log.error(pos, "types.incompatible.diff.ret",
1323 t1, t2, sym.name +
1324 "(" + types.memberType(t2, sym).getParameterTypes() + ")");
1325 return false;
1326 }
1327 return true;
1328 }
1330 /** Return the first method which is defined with same args
1331 * but different return types in two given interfaces, or null if none
1332 * exists.
1333 * @param t1 The first type.
1334 * @param t2 The second type.
1335 * @param site The most derived type.
1336 * @returns symbol from t2 that conflicts with one in t1.
1337 */
1338 private Symbol firstIncompatibility(Type t1, Type t2, Type site) {
1339 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1340 closure(t1, interfaces1);
1341 Map<TypeSymbol,Type> interfaces2;
1342 if (t1 == t2)
1343 interfaces2 = interfaces1;
1344 else
1345 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1347 for (Type t3 : interfaces1.values()) {
1348 for (Type t4 : interfaces2.values()) {
1349 Symbol s = firstDirectIncompatibility(t3, t4, site);
1350 if (s != null) return s;
1351 }
1352 }
1353 return null;
1354 }
1356 /** Compute all the supertypes of t, indexed by type symbol. */
1357 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1358 if (t.tag != CLASS) return;
1359 if (typeMap.put(t.tsym, t) == null) {
1360 closure(types.supertype(t), typeMap);
1361 for (Type i : types.interfaces(t))
1362 closure(i, typeMap);
1363 }
1364 }
1366 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1367 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1368 if (t.tag != CLASS) return;
1369 if (typesSkip.get(t.tsym) != null) return;
1370 if (typeMap.put(t.tsym, t) == null) {
1371 closure(types.supertype(t), typesSkip, typeMap);
1372 for (Type i : types.interfaces(t))
1373 closure(i, typesSkip, typeMap);
1374 }
1375 }
1377 /** Return the first method in t2 that conflicts with a method from t1. */
1378 private Symbol firstDirectIncompatibility(Type t1, Type t2, Type site) {
1379 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1380 Symbol s1 = e1.sym;
1381 Type st1 = null;
1382 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1383 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1384 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1385 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1386 Symbol s2 = e2.sym;
1387 if (s1 == s2) continue;
1388 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1389 if (st1 == null) st1 = types.memberType(t1, s1);
1390 Type st2 = types.memberType(t2, s2);
1391 if (types.overrideEquivalent(st1, st2)) {
1392 List<Type> tvars1 = st1.getTypeArguments();
1393 List<Type> tvars2 = st2.getTypeArguments();
1394 Type rt1 = st1.getReturnType();
1395 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1396 boolean compat =
1397 types.isSameType(rt1, rt2) ||
1398 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1399 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1400 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1401 checkCommonOverriderIn(s1,s2,site);
1402 if (!compat) return s2;
1403 }
1404 }
1405 }
1406 return null;
1407 }
1408 //WHERE
1409 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1410 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1411 Type st1 = types.memberType(site, s1);
1412 Type st2 = types.memberType(site, s2);
1413 closure(site, supertypes);
1414 for (Type t : supertypes.values()) {
1415 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1416 Symbol s3 = e.sym;
1417 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1418 Type st3 = types.memberType(site,s3);
1419 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1420 if (s3.owner == site.tsym) {
1421 return true;
1422 }
1423 List<Type> tvars1 = st1.getTypeArguments();
1424 List<Type> tvars2 = st2.getTypeArguments();
1425 List<Type> tvars3 = st3.getTypeArguments();
1426 Type rt1 = st1.getReturnType();
1427 Type rt2 = st2.getReturnType();
1428 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1429 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1430 boolean compat =
1431 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1432 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1433 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1434 if (compat)
1435 return true;
1436 }
1437 }
1438 }
1439 return false;
1440 }
1442 /** Check that a given method conforms with any method it overrides.
1443 * @param tree The tree from which positions are extracted
1444 * for errors.
1445 * @param m The overriding method.
1446 */
1447 void checkOverride(JCTree tree, MethodSymbol m) {
1448 ClassSymbol origin = (ClassSymbol)m.owner;
1449 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1450 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1451 log.error(tree.pos(), "enum.no.finalize");
1452 return;
1453 }
1454 for (Type t = types.supertype(origin.type); t.tag == CLASS;
1455 t = types.supertype(t)) {
1456 TypeSymbol c = t.tsym;
1457 Scope.Entry e = c.members().lookup(m.name);
1458 while (e.scope != null) {
1459 if (m.overrides(e.sym, origin, types, false))
1460 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1461 else if (e.sym.isInheritedIn(origin, types) && !m.isConstructor()) {
1462 Type er1 = m.erasure(types);
1463 Type er2 = e.sym.erasure(types);
1464 if (types.isSameType(er1,er2)) {
1465 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1466 "name.clash.same.erasure.no.override",
1467 m, m.location(),
1468 e.sym, e.sym.location());
1469 }
1470 }
1471 e = e.next();
1472 }
1473 }
1474 }
1476 /** Check that all abstract members of given class have definitions.
1477 * @param pos Position to be used for error reporting.
1478 * @param c The class.
1479 */
1480 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1481 try {
1482 MethodSymbol undef = firstUndef(c, c);
1483 if (undef != null) {
1484 if ((c.flags() & ENUM) != 0 &&
1485 types.supertype(c.type).tsym == syms.enumSym &&
1486 (c.flags() & FINAL) == 0) {
1487 // add the ABSTRACT flag to an enum
1488 c.flags_field |= ABSTRACT;
1489 } else {
1490 MethodSymbol undef1 =
1491 new MethodSymbol(undef.flags(), undef.name,
1492 types.memberType(c.type, undef), undef.owner);
1493 log.error(pos, "does.not.override.abstract",
1494 c, undef1, undef1.location());
1495 }
1496 }
1497 } catch (CompletionFailure ex) {
1498 completionError(pos, ex);
1499 }
1500 }
1501 //where
1502 /** Return first abstract member of class `c' that is not defined
1503 * in `impl', null if there is none.
1504 */
1505 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1506 MethodSymbol undef = null;
1507 // Do not bother to search in classes that are not abstract,
1508 // since they cannot have abstract members.
1509 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1510 Scope s = c.members();
1511 for (Scope.Entry e = s.elems;
1512 undef == null && e != null;
1513 e = e.sibling) {
1514 if (e.sym.kind == MTH &&
1515 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1516 MethodSymbol absmeth = (MethodSymbol)e.sym;
1517 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1518 if (implmeth == null || implmeth == absmeth)
1519 undef = absmeth;
1520 }
1521 }
1522 if (undef == null) {
1523 Type st = types.supertype(c.type);
1524 if (st.tag == CLASS)
1525 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1526 }
1527 for (List<Type> l = types.interfaces(c.type);
1528 undef == null && l.nonEmpty();
1529 l = l.tail) {
1530 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1531 }
1532 }
1533 return undef;
1534 }
1536 /** Check for cyclic references. Issue an error if the
1537 * symbol of the type referred to has a LOCKED flag set.
1538 *
1539 * @param pos Position to be used for error reporting.
1540 * @param t The type referred to.
1541 */
1542 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1543 checkNonCyclicInternal(pos, t);
1544 }
1547 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1548 checkNonCyclic1(pos, t, List.<TypeVar>nil());
1549 }
1551 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
1552 final TypeVar tv;
1553 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
1554 return;
1555 if (seen.contains(t)) {
1556 tv = (TypeVar)t;
1557 tv.bound = types.createErrorType(t);
1558 log.error(pos, "cyclic.inheritance", t);
1559 } else if (t.tag == TYPEVAR) {
1560 tv = (TypeVar)t;
1561 seen = seen.prepend(tv);
1562 for (Type b : types.getBounds(tv))
1563 checkNonCyclic1(pos, b, seen);
1564 }
1565 }
1567 /** Check for cyclic references. Issue an error if the
1568 * symbol of the type referred to has a LOCKED flag set.
1569 *
1570 * @param pos Position to be used for error reporting.
1571 * @param t The type referred to.
1572 * @returns True if the check completed on all attributed classes
1573 */
1574 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1575 boolean complete = true; // was the check complete?
1576 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1577 Symbol c = t.tsym;
1578 if ((c.flags_field & ACYCLIC) != 0) return true;
1580 if ((c.flags_field & LOCKED) != 0) {
1581 noteCyclic(pos, (ClassSymbol)c);
1582 } else if (!c.type.isErroneous()) {
1583 try {
1584 c.flags_field |= LOCKED;
1585 if (c.type.tag == CLASS) {
1586 ClassType clazz = (ClassType)c.type;
1587 if (clazz.interfaces_field != null)
1588 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1589 complete &= checkNonCyclicInternal(pos, l.head);
1590 if (clazz.supertype_field != null) {
1591 Type st = clazz.supertype_field;
1592 if (st != null && st.tag == CLASS)
1593 complete &= checkNonCyclicInternal(pos, st);
1594 }
1595 if (c.owner.kind == TYP)
1596 complete &= checkNonCyclicInternal(pos, c.owner.type);
1597 }
1598 } finally {
1599 c.flags_field &= ~LOCKED;
1600 }
1601 }
1602 if (complete)
1603 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
1604 if (complete) c.flags_field |= ACYCLIC;
1605 return complete;
1606 }
1608 /** Note that we found an inheritance cycle. */
1609 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
1610 log.error(pos, "cyclic.inheritance", c);
1611 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
1612 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
1613 Type st = types.supertype(c.type);
1614 if (st.tag == CLASS)
1615 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
1616 c.type = types.createErrorType(c, c.type);
1617 c.flags_field |= ACYCLIC;
1618 }
1620 /** Check that all methods which implement some
1621 * method conform to the method they implement.
1622 * @param tree The class definition whose members are checked.
1623 */
1624 void checkImplementations(JCClassDecl tree) {
1625 checkImplementations(tree, tree.sym);
1626 }
1627 //where
1628 /** Check that all methods which implement some
1629 * method in `ic' conform to the method they implement.
1630 */
1631 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
1632 ClassSymbol origin = tree.sym;
1633 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
1634 ClassSymbol lc = (ClassSymbol)l.head.tsym;
1635 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
1636 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
1637 if (e.sym.kind == MTH &&
1638 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
1639 MethodSymbol absmeth = (MethodSymbol)e.sym;
1640 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
1641 if (implmeth != null && implmeth != absmeth &&
1642 (implmeth.owner.flags() & INTERFACE) ==
1643 (origin.flags() & INTERFACE)) {
1644 // don't check if implmeth is in a class, yet
1645 // origin is an interface. This case arises only
1646 // if implmeth is declared in Object. The reason is
1647 // that interfaces really don't inherit from
1648 // Object it's just that the compiler represents
1649 // things that way.
1650 checkOverride(tree, implmeth, absmeth, origin);
1651 }
1652 }
1653 }
1654 }
1655 }
1656 }
1658 /** Check that all abstract methods implemented by a class are
1659 * mutually compatible.
1660 * @param pos Position to be used for error reporting.
1661 * @param c The class whose interfaces are checked.
1662 */
1663 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
1664 List<Type> supertypes = types.interfaces(c);
1665 Type supertype = types.supertype(c);
1666 if (supertype.tag == CLASS &&
1667 (supertype.tsym.flags() & ABSTRACT) != 0)
1668 supertypes = supertypes.prepend(supertype);
1669 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
1670 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
1671 !checkCompatibleAbstracts(pos, l.head, l.head, c))
1672 return;
1673 for (List<Type> m = supertypes; m != l; m = m.tail)
1674 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
1675 return;
1676 }
1677 checkCompatibleConcretes(pos, c);
1678 }
1680 /** Check that class c does not implement directly or indirectly
1681 * the same parameterized interface with two different argument lists.
1682 * @param pos Position to be used for error reporting.
1683 * @param type The type whose interfaces are checked.
1684 */
1685 void checkClassBounds(DiagnosticPosition pos, Type type) {
1686 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
1687 }
1688 //where
1689 /** Enter all interfaces of type `type' into the hash table `seensofar'
1690 * with their class symbol as key and their type as value. Make
1691 * sure no class is entered with two different types.
1692 */
1693 void checkClassBounds(DiagnosticPosition pos,
1694 Map<TypeSymbol,Type> seensofar,
1695 Type type) {
1696 if (type.isErroneous()) return;
1697 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
1698 Type it = l.head;
1699 Type oldit = seensofar.put(it.tsym, it);
1700 if (oldit != null) {
1701 List<Type> oldparams = oldit.allparams();
1702 List<Type> newparams = it.allparams();
1703 if (!types.containsTypeEquivalent(oldparams, newparams))
1704 log.error(pos, "cant.inherit.diff.arg",
1705 it.tsym, Type.toString(oldparams),
1706 Type.toString(newparams));
1707 }
1708 checkClassBounds(pos, seensofar, it);
1709 }
1710 Type st = types.supertype(type);
1711 if (st != null) checkClassBounds(pos, seensofar, st);
1712 }
1714 /** Enter interface into into set.
1715 * If it existed already, issue a "repeated interface" error.
1716 */
1717 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
1718 if (its.contains(it))
1719 log.error(pos, "repeated.interface");
1720 else {
1721 its.add(it);
1722 }
1723 }
1725 /* *************************************************************************
1726 * Check annotations
1727 **************************************************************************/
1729 /** Annotation types are restricted to primitives, String, an
1730 * enum, an annotation, Class, Class<?>, Class<? extends
1731 * Anything>, arrays of the preceding.
1732 */
1733 void validateAnnotationType(JCTree restype) {
1734 // restype may be null if an error occurred, so don't bother validating it
1735 if (restype != null) {
1736 validateAnnotationType(restype.pos(), restype.type);
1737 }
1738 }
1740 void validateAnnotationType(DiagnosticPosition pos, Type type) {
1741 if (type.isPrimitive()) return;
1742 if (types.isSameType(type, syms.stringType)) return;
1743 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
1744 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
1745 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
1746 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
1747 validateAnnotationType(pos, types.elemtype(type));
1748 return;
1749 }
1750 log.error(pos, "invalid.annotation.member.type");
1751 }
1753 /**
1754 * "It is also a compile-time error if any method declared in an
1755 * annotation type has a signature that is override-equivalent to
1756 * that of any public or protected method declared in class Object
1757 * or in the interface annotation.Annotation."
1758 *
1759 * @jls3 9.6 Annotation Types
1760 */
1761 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
1762 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
1763 Scope s = sup.tsym.members();
1764 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
1765 if (e.sym.kind == MTH &&
1766 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
1767 types.overrideEquivalent(m.type, e.sym.type))
1768 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
1769 }
1770 }
1771 }
1773 /** Check the annotations of a symbol.
1774 */
1775 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
1776 if (skipAnnotations) return;
1777 for (JCAnnotation a : annotations)
1778 validateAnnotation(a, s);
1779 }
1781 /** Check an annotation of a symbol.
1782 */
1783 public void validateAnnotation(JCAnnotation a, Symbol s) {
1784 validateAnnotation(a);
1786 if (!annotationApplicable(a, s))
1787 log.error(a.pos(), "annotation.type.not.applicable");
1789 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
1790 if (!isOverrider(s))
1791 log.error(a.pos(), "method.does.not.override.superclass");
1792 }
1793 }
1795 /** Is s a method symbol that overrides a method in a superclass? */
1796 boolean isOverrider(Symbol s) {
1797 if (s.kind != MTH || s.isStatic())
1798 return false;
1799 MethodSymbol m = (MethodSymbol)s;
1800 TypeSymbol owner = (TypeSymbol)m.owner;
1801 for (Type sup : types.closure(owner.type)) {
1802 if (sup == owner.type)
1803 continue; // skip "this"
1804 Scope scope = sup.tsym.members();
1805 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
1806 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
1807 return true;
1808 }
1809 }
1810 return false;
1811 }
1813 /** Is the annotation applicable to the symbol? */
1814 boolean annotationApplicable(JCAnnotation a, Symbol s) {
1815 Attribute.Compound atTarget =
1816 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
1817 if (atTarget == null) return true;
1818 Attribute atValue = atTarget.member(names.value);
1819 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
1820 Attribute.Array arr = (Attribute.Array) atValue;
1821 for (Attribute app : arr.values) {
1822 if (!(app instanceof Attribute.Enum)) return true; // recovery
1823 Attribute.Enum e = (Attribute.Enum) app;
1824 if (e.value.name == names.TYPE)
1825 { if (s.kind == TYP) return true; }
1826 else if (e.value.name == names.FIELD)
1827 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
1828 else if (e.value.name == names.METHOD)
1829 { if (s.kind == MTH && !s.isConstructor()) return true; }
1830 else if (e.value.name == names.PARAMETER)
1831 { if (s.kind == VAR &&
1832 s.owner.kind == MTH &&
1833 (s.flags() & PARAMETER) != 0)
1834 return true;
1835 }
1836 else if (e.value.name == names.CONSTRUCTOR)
1837 { if (s.kind == MTH && s.isConstructor()) return true; }
1838 else if (e.value.name == names.LOCAL_VARIABLE)
1839 { if (s.kind == VAR && s.owner.kind == MTH &&
1840 (s.flags() & PARAMETER) == 0)
1841 return true;
1842 }
1843 else if (e.value.name == names.ANNOTATION_TYPE)
1844 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
1845 return true;
1846 }
1847 else if (e.value.name == names.PACKAGE)
1848 { if (s.kind == PCK) return true; }
1849 else
1850 return true; // recovery
1851 }
1852 return false;
1853 }
1855 /** Check an annotation value.
1856 */
1857 public void validateAnnotation(JCAnnotation a) {
1858 if (a.type.isErroneous()) return;
1860 // collect an inventory of the members
1861 Set<MethodSymbol> members = new HashSet<MethodSymbol>();
1862 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
1863 e != null;
1864 e = e.sibling)
1865 if (e.sym.kind == MTH)
1866 members.add((MethodSymbol) e.sym);
1868 // count them off as they're annotated
1869 for (JCTree arg : a.args) {
1870 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
1871 JCAssign assign = (JCAssign) arg;
1872 Symbol m = TreeInfo.symbol(assign.lhs);
1873 if (m == null || m.type.isErroneous()) continue;
1874 if (!members.remove(m))
1875 log.error(arg.pos(), "duplicate.annotation.member.value",
1876 m.name, a.type);
1877 if (assign.rhs.getTag() == ANNOTATION)
1878 validateAnnotation((JCAnnotation)assign.rhs);
1879 }
1881 // all the remaining ones better have default values
1882 for (MethodSymbol m : members)
1883 if (m.defaultValue == null && !m.type.isErroneous())
1884 log.error(a.pos(), "annotation.missing.default.value",
1885 a.type, m.name);
1887 // special case: java.lang.annotation.Target must not have
1888 // repeated values in its value member
1889 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
1890 a.args.tail == null)
1891 return;
1893 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
1894 JCAssign assign = (JCAssign) a.args.head;
1895 Symbol m = TreeInfo.symbol(assign.lhs);
1896 if (m.name != names.value) return;
1897 JCTree rhs = assign.rhs;
1898 if (rhs.getTag() != JCTree.NEWARRAY) return;
1899 JCNewArray na = (JCNewArray) rhs;
1900 Set<Symbol> targets = new HashSet<Symbol>();
1901 for (JCTree elem : na.elems) {
1902 if (!targets.add(TreeInfo.symbol(elem))) {
1903 log.error(elem.pos(), "repeated.annotation.target");
1904 }
1905 }
1906 }
1908 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
1909 if (allowAnnotations &&
1910 lint.isEnabled(Lint.LintCategory.DEP_ANN) &&
1911 (s.flags() & DEPRECATED) != 0 &&
1912 !syms.deprecatedType.isErroneous() &&
1913 s.attribute(syms.deprecatedType.tsym) == null) {
1914 log.warning(pos, "missing.deprecated.annotation");
1915 }
1916 }
1918 /* *************************************************************************
1919 * Check for recursive annotation elements.
1920 **************************************************************************/
1922 /** Check for cycles in the graph of annotation elements.
1923 */
1924 void checkNonCyclicElements(JCClassDecl tree) {
1925 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
1926 assert (tree.sym.flags_field & LOCKED) == 0;
1927 try {
1928 tree.sym.flags_field |= LOCKED;
1929 for (JCTree def : tree.defs) {
1930 if (def.getTag() != JCTree.METHODDEF) continue;
1931 JCMethodDecl meth = (JCMethodDecl)def;
1932 checkAnnotationResType(meth.pos(), meth.restype.type);
1933 }
1934 } finally {
1935 tree.sym.flags_field &= ~LOCKED;
1936 tree.sym.flags_field |= ACYCLIC_ANN;
1937 }
1938 }
1940 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
1941 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
1942 return;
1943 if ((tsym.flags_field & LOCKED) != 0) {
1944 log.error(pos, "cyclic.annotation.element");
1945 return;
1946 }
1947 try {
1948 tsym.flags_field |= LOCKED;
1949 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
1950 Symbol s = e.sym;
1951 if (s.kind != Kinds.MTH)
1952 continue;
1953 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
1954 }
1955 } finally {
1956 tsym.flags_field &= ~LOCKED;
1957 tsym.flags_field |= ACYCLIC_ANN;
1958 }
1959 }
1961 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
1962 switch (type.tag) {
1963 case TypeTags.CLASS:
1964 if ((type.tsym.flags() & ANNOTATION) != 0)
1965 checkNonCyclicElementsInternal(pos, type.tsym);
1966 break;
1967 case TypeTags.ARRAY:
1968 checkAnnotationResType(pos, types.elemtype(type));
1969 break;
1970 default:
1971 break; // int etc
1972 }
1973 }
1975 /* *************************************************************************
1976 * Check for cycles in the constructor call graph.
1977 **************************************************************************/
1979 /** Check for cycles in the graph of constructors calling other
1980 * constructors.
1981 */
1982 void checkCyclicConstructors(JCClassDecl tree) {
1983 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
1985 // enter each constructor this-call into the map
1986 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
1987 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
1988 if (app == null) continue;
1989 JCMethodDecl meth = (JCMethodDecl) l.head;
1990 if (TreeInfo.name(app.meth) == names._this) {
1991 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
1992 } else {
1993 meth.sym.flags_field |= ACYCLIC;
1994 }
1995 }
1997 // Check for cycles in the map
1998 Symbol[] ctors = new Symbol[0];
1999 ctors = callMap.keySet().toArray(ctors);
2000 for (Symbol caller : ctors) {
2001 checkCyclicConstructor(tree, caller, callMap);
2002 }
2003 }
2005 /** Look in the map to see if the given constructor is part of a
2006 * call cycle.
2007 */
2008 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
2009 Map<Symbol,Symbol> callMap) {
2010 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
2011 if ((ctor.flags_field & LOCKED) != 0) {
2012 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
2013 "recursive.ctor.invocation");
2014 } else {
2015 ctor.flags_field |= LOCKED;
2016 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2017 ctor.flags_field &= ~LOCKED;
2018 }
2019 ctor.flags_field |= ACYCLIC;
2020 }
2021 }
2023 /* *************************************************************************
2024 * Miscellaneous
2025 **************************************************************************/
2027 /**
2028 * Return the opcode of the operator but emit an error if it is an
2029 * error.
2030 * @param pos position for error reporting.
2031 * @param operator an operator
2032 * @param tag a tree tag
2033 * @param left type of left hand side
2034 * @param right type of right hand side
2035 */
2036 int checkOperator(DiagnosticPosition pos,
2037 OperatorSymbol operator,
2038 int tag,
2039 Type left,
2040 Type right) {
2041 if (operator.opcode == ByteCodes.error) {
2042 log.error(pos,
2043 "operator.cant.be.applied",
2044 treeinfo.operatorName(tag),
2045 List.of(left, right));
2046 }
2047 return operator.opcode;
2048 }
2051 /**
2052 * Check for division by integer constant zero
2053 * @param pos Position for error reporting.
2054 * @param operator The operator for the expression
2055 * @param operand The right hand operand for the expression
2056 */
2057 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
2058 if (operand.constValue() != null
2059 && lint.isEnabled(Lint.LintCategory.DIVZERO)
2060 && operand.tag <= LONG
2061 && ((Number) (operand.constValue())).longValue() == 0) {
2062 int opc = ((OperatorSymbol)operator).opcode;
2063 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
2064 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
2065 log.warning(pos, "div.zero");
2066 }
2067 }
2068 }
2070 /**
2071 * Check for empty statements after if
2072 */
2073 void checkEmptyIf(JCIf tree) {
2074 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(Lint.LintCategory.EMPTY))
2075 log.warning(tree.thenpart.pos(), "empty.if");
2076 }
2078 /** Check that symbol is unique in given scope.
2079 * @param pos Position for error reporting.
2080 * @param sym The symbol.
2081 * @param s The scope.
2082 */
2083 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2084 if (sym.type.isErroneous())
2085 return true;
2086 if (sym.owner.name == names.any) return false;
2087 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2088 if (sym != e.sym &&
2089 sym.kind == e.sym.kind &&
2090 sym.name != names.error &&
2091 (sym.kind != MTH || types.overrideEquivalent(sym.type, e.sym.type))) {
2092 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS))
2093 varargsDuplicateError(pos, sym, e.sym);
2094 else
2095 duplicateError(pos, e.sym);
2096 return false;
2097 }
2098 }
2099 return true;
2100 }
2102 /** Check that single-type import is not already imported or top-level defined,
2103 * but make an exception for two single-type imports which denote the same type.
2104 * @param pos Position for error reporting.
2105 * @param sym The symbol.
2106 * @param s The scope
2107 */
2108 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2109 return checkUniqueImport(pos, sym, s, false);
2110 }
2112 /** Check that static single-type import is not already imported or top-level defined,
2113 * but make an exception for two single-type imports which denote the same type.
2114 * @param pos Position for error reporting.
2115 * @param sym The symbol.
2116 * @param s The scope
2117 * @param staticImport Whether or not this was a static import
2118 */
2119 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2120 return checkUniqueImport(pos, sym, s, true);
2121 }
2123 /** Check that single-type import is not already imported or top-level defined,
2124 * but make an exception for two single-type imports which denote the same type.
2125 * @param pos Position for error reporting.
2126 * @param sym The symbol.
2127 * @param s The scope.
2128 * @param staticImport Whether or not this was a static import
2129 */
2130 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2131 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2132 // is encountered class entered via a class declaration?
2133 boolean isClassDecl = e.scope == s;
2134 if ((isClassDecl || sym != e.sym) &&
2135 sym.kind == e.sym.kind &&
2136 sym.name != names.error) {
2137 if (!e.sym.type.isErroneous()) {
2138 String what = e.sym.toString();
2139 if (!isClassDecl) {
2140 if (staticImport)
2141 log.error(pos, "already.defined.static.single.import", what);
2142 else
2143 log.error(pos, "already.defined.single.import", what);
2144 }
2145 else if (sym != e.sym)
2146 log.error(pos, "already.defined.this.unit", what);
2147 }
2148 return false;
2149 }
2150 }
2151 return true;
2152 }
2154 /** Check that a qualified name is in canonical form (for import decls).
2155 */
2156 public void checkCanonical(JCTree tree) {
2157 if (!isCanonical(tree))
2158 log.error(tree.pos(), "import.requires.canonical",
2159 TreeInfo.symbol(tree));
2160 }
2161 // where
2162 private boolean isCanonical(JCTree tree) {
2163 while (tree.getTag() == JCTree.SELECT) {
2164 JCFieldAccess s = (JCFieldAccess) tree;
2165 if (s.sym.owner != TreeInfo.symbol(s.selected))
2166 return false;
2167 tree = s.selected;
2168 }
2169 return true;
2170 }
2172 private class ConversionWarner extends Warner {
2173 final String key;
2174 final Type found;
2175 final Type expected;
2176 public ConversionWarner(DiagnosticPosition pos, String key, Type found, Type expected) {
2177 super(pos);
2178 this.key = key;
2179 this.found = found;
2180 this.expected = expected;
2181 }
2183 public void warnUnchecked() {
2184 boolean warned = this.warned;
2185 super.warnUnchecked();
2186 if (warned) return; // suppress redundant diagnostics
2187 Object problem = diags.fragment(key);
2188 Check.this.warnUnchecked(pos(), "prob.found.req", problem, found, expected);
2189 }
2190 }
2192 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2193 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2194 }
2196 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2197 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2198 }
2199 }
