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src/share/classes/com/sun/tools/javac/comp/Check.java@a2d422d480cb
src/share/classes/com/sun/tools/javac/comp/Check.java
Wed, 11 May 2011 13:10:57 +0200
- author
- mcimadamore
- date
- Wed, 11 May 2011 13:10:57 +0200
- changeset 1006
- a2d422d480cb
- parent 993
- 4caf17560ae0
- child 1015
- 6bb526ccf5ff
- permissions
- -rw-r--r--
7042566: Regression: new ambiguity between varargs method
Summary: Erroneous ambiguity error when choosing most specific varargs method
Reviewed-by: jjg
1 /*
2 * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
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 import static com.sun.tools.javac.main.OptionName.*;
50 /** Type checking helper class for the attribution phase.
51 *
52 * <p><b>This is NOT part of any supported API.
53 * If you write code that depends on this, you do so at your own risk.
54 * This code and its internal interfaces are subject to change or
55 * deletion without notice.</b>
56 */
57 public class Check {
58 protected static final Context.Key<Check> checkKey =
59 new Context.Key<Check>();
61 private final Names names;
62 private final Log log;
63 private final Symtab syms;
64 private final Enter enter;
65 private final Infer infer;
66 private final Types types;
67 private final JCDiagnostic.Factory diags;
68 private final boolean skipAnnotations;
69 private boolean warnOnSyntheticConflicts;
70 private boolean suppressAbortOnBadClassFile;
71 private boolean enableSunApiLintControl;
72 private final TreeInfo treeinfo;
74 // The set of lint options currently in effect. It is initialized
75 // from the context, and then is set/reset as needed by Attr as it
76 // visits all the various parts of the trees during attribution.
77 private Lint lint;
79 // The method being analyzed in Attr - it is set/reset as needed by
80 // Attr as it visits new method declarations.
81 private MethodSymbol method;
83 public static Check instance(Context context) {
84 Check instance = context.get(checkKey);
85 if (instance == null)
86 instance = new Check(context);
87 return instance;
88 }
90 protected Check(Context context) {
91 context.put(checkKey, this);
93 names = Names.instance(context);
94 log = Log.instance(context);
95 syms = Symtab.instance(context);
96 enter = Enter.instance(context);
97 infer = Infer.instance(context);
98 this.types = Types.instance(context);
99 diags = JCDiagnostic.Factory.instance(context);
100 Options options = Options.instance(context);
101 lint = Lint.instance(context);
102 treeinfo = TreeInfo.instance(context);
104 Source source = Source.instance(context);
105 allowGenerics = source.allowGenerics();
106 allowAnnotations = source.allowAnnotations();
107 allowCovariantReturns = source.allowCovariantReturns();
108 allowSimplifiedVarargs = source.allowSimplifiedVarargs();
109 complexInference = options.isSet(COMPLEXINFERENCE);
110 skipAnnotations = options.isSet("skipAnnotations");
111 warnOnSyntheticConflicts = options.isSet("warnOnSyntheticConflicts");
112 suppressAbortOnBadClassFile = options.isSet("suppressAbortOnBadClassFile");
113 enableSunApiLintControl = options.isSet("enableSunApiLintControl");
115 Target target = Target.instance(context);
116 syntheticNameChar = target.syntheticNameChar();
118 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
119 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
120 boolean verboseSunApi = lint.isEnabled(LintCategory.SUNAPI);
121 boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
123 deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
124 enforceMandatoryWarnings, "deprecated", LintCategory.DEPRECATION);
125 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
126 enforceMandatoryWarnings, "unchecked", LintCategory.UNCHECKED);
127 sunApiHandler = new MandatoryWarningHandler(log, verboseSunApi,
128 enforceMandatoryWarnings, "sunapi", null);
130 deferredLintHandler = DeferredLintHandler.immediateHandler;
131 }
133 /** Switch: generics enabled?
134 */
135 boolean allowGenerics;
137 /** Switch: annotations enabled?
138 */
139 boolean allowAnnotations;
141 /** Switch: covariant returns enabled?
142 */
143 boolean allowCovariantReturns;
145 /** Switch: simplified varargs enabled?
146 */
147 boolean allowSimplifiedVarargs;
149 /** Switch: -complexinference option set?
150 */
151 boolean complexInference;
153 /** Character for synthetic names
154 */
155 char syntheticNameChar;
157 /** A table mapping flat names of all compiled classes in this run to their
158 * symbols; maintained from outside.
159 */
160 public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
162 /** A handler for messages about deprecated usage.
163 */
164 private MandatoryWarningHandler deprecationHandler;
166 /** A handler for messages about unchecked or unsafe usage.
167 */
168 private MandatoryWarningHandler uncheckedHandler;
170 /** A handler for messages about using proprietary API.
171 */
172 private MandatoryWarningHandler sunApiHandler;
174 /** A handler for deferred lint warnings.
175 */
176 private DeferredLintHandler deferredLintHandler;
178 /* *************************************************************************
179 * Errors and Warnings
180 **************************************************************************/
182 Lint setLint(Lint newLint) {
183 Lint prev = lint;
184 lint = newLint;
185 return prev;
186 }
188 DeferredLintHandler setDeferredLintHandler(DeferredLintHandler newDeferredLintHandler) {
189 DeferredLintHandler prev = deferredLintHandler;
190 deferredLintHandler = newDeferredLintHandler;
191 return prev;
192 }
194 MethodSymbol setMethod(MethodSymbol newMethod) {
195 MethodSymbol prev = method;
196 method = newMethod;
197 return prev;
198 }
200 /** Warn about deprecated symbol.
201 * @param pos Position to be used for error reporting.
202 * @param sym The deprecated symbol.
203 */
204 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
205 if (!lint.isSuppressed(LintCategory.DEPRECATION))
206 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
207 }
209 /** Warn about unchecked operation.
210 * @param pos Position to be used for error reporting.
211 * @param msg A string describing the problem.
212 */
213 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
214 if (!lint.isSuppressed(LintCategory.UNCHECKED))
215 uncheckedHandler.report(pos, msg, args);
216 }
218 /** Warn about unsafe vararg method decl.
219 * @param pos Position to be used for error reporting.
220 * @param sym The deprecated symbol.
221 */
222 void warnUnsafeVararg(DiagnosticPosition pos, String key, Object... args) {
223 if (lint.isEnabled(LintCategory.VARARGS) && allowSimplifiedVarargs)
224 log.warning(LintCategory.VARARGS, pos, key, args);
225 }
227 /** Warn about using proprietary API.
228 * @param pos Position to be used for error reporting.
229 * @param msg A string describing the problem.
230 */
231 public void warnSunApi(DiagnosticPosition pos, String msg, Object... args) {
232 if (!lint.isSuppressed(LintCategory.SUNAPI))
233 sunApiHandler.report(pos, msg, args);
234 }
236 public void warnStatic(DiagnosticPosition pos, String msg, Object... args) {
237 if (lint.isEnabled(LintCategory.STATIC))
238 log.warning(LintCategory.STATIC, pos, msg, args);
239 }
241 /**
242 * Report any deferred diagnostics.
243 */
244 public void reportDeferredDiagnostics() {
245 deprecationHandler.reportDeferredDiagnostic();
246 uncheckedHandler.reportDeferredDiagnostic();
247 sunApiHandler.reportDeferredDiagnostic();
248 }
251 /** Report a failure to complete a class.
252 * @param pos Position to be used for error reporting.
253 * @param ex The failure to report.
254 */
255 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
256 log.error(pos, "cant.access", ex.sym, ex.getDetailValue());
257 if (ex instanceof ClassReader.BadClassFile
258 && !suppressAbortOnBadClassFile) throw new Abort();
259 else return syms.errType;
260 }
262 /** Report a type error.
263 * @param pos Position to be used for error reporting.
264 * @param problem A string describing the error.
265 * @param found The type that was found.
266 * @param req The type that was required.
267 */
268 Type typeError(DiagnosticPosition pos, Object problem, Type found, Type req) {
269 log.error(pos, "prob.found.req",
270 problem, found, req);
271 return types.createErrorType(found);
272 }
274 Type typeError(DiagnosticPosition pos, String problem, Type found, Type req, Object explanation) {
275 log.error(pos, "prob.found.req.1", problem, found, req, explanation);
276 return types.createErrorType(found);
277 }
279 /** Report an error that wrong type tag was found.
280 * @param pos Position to be used for error reporting.
281 * @param required An internationalized string describing the type tag
282 * required.
283 * @param found The type that was found.
284 */
285 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
286 // this error used to be raised by the parser,
287 // but has been delayed to this point:
288 if (found instanceof Type && ((Type)found).tag == VOID) {
289 log.error(pos, "illegal.start.of.type");
290 return syms.errType;
291 }
292 log.error(pos, "type.found.req", found, required);
293 return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
294 }
296 /** Report an error that symbol cannot be referenced before super
297 * has been called.
298 * @param pos Position to be used for error reporting.
299 * @param sym The referenced symbol.
300 */
301 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
302 log.error(pos, "cant.ref.before.ctor.called", sym);
303 }
305 /** Report duplicate declaration error.
306 */
307 void duplicateError(DiagnosticPosition pos, Symbol sym) {
308 if (!sym.type.isErroneous()) {
309 log.error(pos, "already.defined", sym, sym.location());
310 }
311 }
313 /** Report array/varargs duplicate declaration
314 */
315 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
316 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
317 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
318 }
319 }
321 /* ************************************************************************
322 * duplicate declaration checking
323 *************************************************************************/
325 /** Check that variable does not hide variable with same name in
326 * immediately enclosing local scope.
327 * @param pos Position for error reporting.
328 * @param v The symbol.
329 * @param s The scope.
330 */
331 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
332 if (s.next != null) {
333 for (Scope.Entry e = s.next.lookup(v.name);
334 e.scope != null && e.sym.owner == v.owner;
335 e = e.next()) {
336 if (e.sym.kind == VAR &&
337 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
338 v.name != names.error) {
339 duplicateError(pos, e.sym);
340 return;
341 }
342 }
343 }
344 }
346 /** Check that a class or interface does not hide a class or
347 * interface with same name in immediately enclosing local scope.
348 * @param pos Position for error reporting.
349 * @param c The symbol.
350 * @param s The scope.
351 */
352 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
353 if (s.next != null) {
354 for (Scope.Entry e = s.next.lookup(c.name);
355 e.scope != null && e.sym.owner == c.owner;
356 e = e.next()) {
357 if (e.sym.kind == TYP && e.sym.type.tag != TYPEVAR &&
358 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
359 c.name != names.error) {
360 duplicateError(pos, e.sym);
361 return;
362 }
363 }
364 }
365 }
367 /** Check that class does not have the same name as one of
368 * its enclosing classes, or as a class defined in its enclosing scope.
369 * return true if class is unique in its enclosing scope.
370 * @param pos Position for error reporting.
371 * @param name The class name.
372 * @param s The enclosing scope.
373 */
374 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
375 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
376 if (e.sym.kind == TYP && e.sym.name != names.error) {
377 duplicateError(pos, e.sym);
378 return false;
379 }
380 }
381 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
382 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
383 duplicateError(pos, sym);
384 return true;
385 }
386 }
387 return true;
388 }
390 /* *************************************************************************
391 * Class name generation
392 **************************************************************************/
394 /** Return name of local class.
395 * This is of the form <enclClass> $ n <classname>
396 * where
397 * enclClass is the flat name of the enclosing class,
398 * classname is the simple name of the local class
399 */
400 Name localClassName(ClassSymbol c) {
401 for (int i=1; ; i++) {
402 Name flatname = names.
403 fromString("" + c.owner.enclClass().flatname +
404 syntheticNameChar + i +
405 c.name);
406 if (compiled.get(flatname) == null) return flatname;
407 }
408 }
410 /* *************************************************************************
411 * Type Checking
412 **************************************************************************/
414 /** Check that a given type is assignable to a given proto-type.
415 * If it is, return the type, otherwise return errType.
416 * @param pos Position to be used for error reporting.
417 * @param found The type that was found.
418 * @param req The type that was required.
419 */
420 Type checkType(DiagnosticPosition pos, Type found, Type req) {
421 return checkType(pos, found, req, "incompatible.types");
422 }
424 Type checkType(DiagnosticPosition pos, Type found, Type req, String errKey) {
425 if (req.tag == ERROR)
426 return req;
427 if (found.tag == FORALL)
428 return instantiatePoly(pos, (ForAll)found, req, convertWarner(pos, found, req));
429 if (req.tag == NONE)
430 return found;
431 if (types.isAssignable(found, req, convertWarner(pos, found, req)))
432 return found;
433 if (found.tag <= DOUBLE && req.tag <= DOUBLE)
434 return typeError(pos, diags.fragment("possible.loss.of.precision"), found, req);
435 if (found.isSuperBound()) {
436 log.error(pos, "assignment.from.super-bound", found);
437 return types.createErrorType(found);
438 }
439 if (req.isExtendsBound()) {
440 log.error(pos, "assignment.to.extends-bound", req);
441 return types.createErrorType(found);
442 }
443 return typeError(pos, diags.fragment(errKey), found, req);
444 }
446 /** Instantiate polymorphic type to some prototype, unless
447 * prototype is `anyPoly' in which case polymorphic type
448 * is returned unchanged.
449 */
450 Type instantiatePoly(DiagnosticPosition pos, ForAll t, Type pt, Warner warn) throws Infer.NoInstanceException {
451 if (pt == Infer.anyPoly && complexInference) {
452 return t;
453 } else if (pt == Infer.anyPoly || pt.tag == NONE) {
454 Type newpt = t.qtype.tag <= VOID ? t.qtype : syms.objectType;
455 return instantiatePoly(pos, t, newpt, warn);
456 } else if (pt.tag == ERROR) {
457 return pt;
458 } else {
459 try {
460 return infer.instantiateExpr(t, pt, warn);
461 } catch (Infer.NoInstanceException ex) {
462 if (ex.isAmbiguous) {
463 JCDiagnostic d = ex.getDiagnostic();
464 log.error(pos,
465 "undetermined.type" + (d!=null ? ".1" : ""),
466 t, d);
467 return types.createErrorType(pt);
468 } else {
469 JCDiagnostic d = ex.getDiagnostic();
470 return typeError(pos,
471 diags.fragment("incompatible.types" + (d!=null ? ".1" : ""), d),
472 t, pt);
473 }
474 } catch (Infer.InvalidInstanceException ex) {
475 JCDiagnostic d = ex.getDiagnostic();
476 log.error(pos, "invalid.inferred.types", t.tvars, d);
477 return types.createErrorType(pt);
478 }
479 }
480 }
482 /** Check that a given type can be cast to a given target type.
483 * Return the result of the cast.
484 * @param pos Position to be used for error reporting.
485 * @param found The type that is being cast.
486 * @param req The target type of the cast.
487 */
488 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
489 if (found.tag == FORALL) {
490 instantiatePoly(pos, (ForAll) found, req, castWarner(pos, found, req));
491 return req;
492 } else if (types.isCastable(found, req, castWarner(pos, found, req))) {
493 return req;
494 } else {
495 return typeError(pos,
496 diags.fragment("inconvertible.types"),
497 found, req);
498 }
499 }
500 //where
501 /** Is type a type variable, or a (possibly multi-dimensional) array of
502 * type variables?
503 */
504 boolean isTypeVar(Type t) {
505 return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
506 }
508 /** Check that a type is within some bounds.
509 *
510 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
511 * type argument.
512 * @param pos Position to be used for error reporting.
513 * @param a The type that should be bounded by bs.
514 * @param bs The bound.
515 */
516 private boolean checkExtends(Type a, TypeVar bs) {
517 if (a.isUnbound()) {
518 return true;
519 } else if (a.tag != WILDCARD) {
520 a = types.upperBound(a);
521 return types.isSubtype(a, bs.bound);
522 } else if (a.isExtendsBound()) {
523 return types.isCastable(bs.getUpperBound(), types.upperBound(a), Warner.noWarnings);
524 } else if (a.isSuperBound()) {
525 return !types.notSoftSubtype(types.lowerBound(a), bs.getUpperBound());
526 }
527 return true;
528 }
530 /** Check that type is different from 'void'.
531 * @param pos Position to be used for error reporting.
532 * @param t The type to be checked.
533 */
534 Type checkNonVoid(DiagnosticPosition pos, Type t) {
535 if (t.tag == VOID) {
536 log.error(pos, "void.not.allowed.here");
537 return types.createErrorType(t);
538 } else {
539 return t;
540 }
541 }
543 /** Check that type is a class or interface type.
544 * @param pos Position to be used for error reporting.
545 * @param t The type to be checked.
546 */
547 Type checkClassType(DiagnosticPosition pos, Type t) {
548 if (t.tag != CLASS && t.tag != ERROR)
549 return typeTagError(pos,
550 diags.fragment("type.req.class"),
551 (t.tag == TYPEVAR)
552 ? diags.fragment("type.parameter", t)
553 : t);
554 else
555 return t;
556 }
558 /** Check that type is a class or interface type.
559 * @param pos Position to be used for error reporting.
560 * @param t The type to be checked.
561 * @param noBounds True if type bounds are illegal here.
562 */
563 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
564 t = checkClassType(pos, t);
565 if (noBounds && t.isParameterized()) {
566 List<Type> args = t.getTypeArguments();
567 while (args.nonEmpty()) {
568 if (args.head.tag == WILDCARD)
569 return typeTagError(pos,
570 diags.fragment("type.req.exact"),
571 args.head);
572 args = args.tail;
573 }
574 }
575 return t;
576 }
578 /** Check that type is a reifiable class, interface or array type.
579 * @param pos Position to be used for error reporting.
580 * @param t The type to be checked.
581 */
582 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
583 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
584 return typeTagError(pos,
585 diags.fragment("type.req.class.array"),
586 t);
587 } else if (!types.isReifiable(t)) {
588 log.error(pos, "illegal.generic.type.for.instof");
589 return types.createErrorType(t);
590 } else {
591 return t;
592 }
593 }
595 /** Check that type is a reference type, i.e. a class, interface or array type
596 * or a type variable.
597 * @param pos Position to be used for error reporting.
598 * @param t The type to be checked.
599 */
600 Type checkRefType(DiagnosticPosition pos, Type t) {
601 switch (t.tag) {
602 case CLASS:
603 case ARRAY:
604 case TYPEVAR:
605 case WILDCARD:
606 case ERROR:
607 return t;
608 default:
609 return typeTagError(pos,
610 diags.fragment("type.req.ref"),
611 t);
612 }
613 }
615 /** Check that each type is a reference type, i.e. a class, interface or array type
616 * or a type variable.
617 * @param trees Original trees, used for error reporting.
618 * @param types The types to be checked.
619 */
620 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
621 List<JCExpression> tl = trees;
622 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
623 l.head = checkRefType(tl.head.pos(), l.head);
624 tl = tl.tail;
625 }
626 return types;
627 }
629 /** Check that type is a null or reference type.
630 * @param pos Position to be used for error reporting.
631 * @param t The type to be checked.
632 */
633 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
634 switch (t.tag) {
635 case CLASS:
636 case ARRAY:
637 case TYPEVAR:
638 case WILDCARD:
639 case BOT:
640 case ERROR:
641 return t;
642 default:
643 return typeTagError(pos,
644 diags.fragment("type.req.ref"),
645 t);
646 }
647 }
649 /** Check that flag set does not contain elements of two conflicting sets. s
650 * Return true if it doesn't.
651 * @param pos Position to be used for error reporting.
652 * @param flags The set of flags to be checked.
653 * @param set1 Conflicting flags set #1.
654 * @param set2 Conflicting flags set #2.
655 */
656 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
657 if ((flags & set1) != 0 && (flags & set2) != 0) {
658 log.error(pos,
659 "illegal.combination.of.modifiers",
660 asFlagSet(TreeInfo.firstFlag(flags & set1)),
661 asFlagSet(TreeInfo.firstFlag(flags & set2)));
662 return false;
663 } else
664 return true;
665 }
667 /** Check that usage of diamond operator is correct (i.e. diamond should not
668 * be used with non-generic classes or in anonymous class creation expressions)
669 */
670 Type checkDiamond(JCNewClass tree, Type t) {
671 if (!TreeInfo.isDiamond(tree) ||
672 t.isErroneous()) {
673 return checkClassType(tree.clazz.pos(), t, true);
674 } else if (tree.def != null) {
675 log.error(tree.clazz.pos(),
676 "cant.apply.diamond.1",
677 t, diags.fragment("diamond.and.anon.class", t));
678 return types.createErrorType(t);
679 } else if (t.tsym.type.getTypeArguments().isEmpty()) {
680 log.error(tree.clazz.pos(),
681 "cant.apply.diamond.1",
682 t, diags.fragment("diamond.non.generic", t));
683 return types.createErrorType(t);
684 } else if (tree.typeargs != null &&
685 tree.typeargs.nonEmpty()) {
686 log.error(tree.clazz.pos(),
687 "cant.apply.diamond.1",
688 t, diags.fragment("diamond.and.explicit.params", t));
689 return types.createErrorType(t);
690 } else {
691 return t;
692 }
693 }
695 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
696 MethodSymbol m = tree.sym;
697 if (!allowSimplifiedVarargs) return;
698 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
699 Type varargElemType = null;
700 if (m.isVarArgs()) {
701 varargElemType = types.elemtype(tree.params.last().type);
702 }
703 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
704 if (varargElemType != null) {
705 log.error(tree,
706 "varargs.invalid.trustme.anno",
707 syms.trustMeType.tsym,
708 diags.fragment("varargs.trustme.on.virtual.varargs", m));
709 } else {
710 log.error(tree,
711 "varargs.invalid.trustme.anno",
712 syms.trustMeType.tsym,
713 diags.fragment("varargs.trustme.on.non.varargs.meth", m));
714 }
715 } else if (hasTrustMeAnno && varargElemType != null &&
716 types.isReifiable(varargElemType)) {
717 warnUnsafeVararg(tree,
718 "varargs.redundant.trustme.anno",
719 syms.trustMeType.tsym,
720 diags.fragment("varargs.trustme.on.reifiable.varargs", varargElemType));
721 }
722 else if (!hasTrustMeAnno && varargElemType != null &&
723 !types.isReifiable(varargElemType)) {
724 warnUnchecked(tree.params.head.pos(), "unchecked.varargs.non.reifiable.type", varargElemType);
725 }
726 }
727 //where
728 private boolean isTrustMeAllowedOnMethod(Symbol s) {
729 return (s.flags() & VARARGS) != 0 &&
730 (s.isConstructor() ||
731 (s.flags() & (STATIC | FINAL)) != 0);
732 }
734 /**
735 * Check that vararg method call is sound
736 * @param pos Position to be used for error reporting.
737 * @param argtypes Actual arguments supplied to vararg method.
738 */
739 void checkVararg(DiagnosticPosition pos, List<Type> argtypes, Symbol msym) {
740 Type argtype = argtypes.last();
741 if (!types.isReifiable(argtype) &&
742 (!allowSimplifiedVarargs ||
743 msym.attribute(syms.trustMeType.tsym) == null ||
744 !isTrustMeAllowedOnMethod(msym))) {
745 warnUnchecked(pos,
746 "unchecked.generic.array.creation",
747 argtype);
748 }
749 }
751 /**
752 * Check that type 't' is a valid instantiation of a generic class
753 * (see JLS 4.5)
754 *
755 * @param t class type to be checked
756 * @return true if 't' is well-formed
757 */
758 public boolean checkValidGenericType(Type t) {
759 return firstIncompatibleTypeArg(t) == null;
760 }
761 //WHERE
762 private Type firstIncompatibleTypeArg(Type type) {
763 List<Type> formals = type.tsym.type.allparams();
764 List<Type> actuals = type.allparams();
765 List<Type> args = type.getTypeArguments();
766 List<Type> forms = type.tsym.type.getTypeArguments();
767 ListBuffer<Type> tvars_buf = new ListBuffer<Type>();
769 // For matching pairs of actual argument types `a' and
770 // formal type parameters with declared bound `b' ...
771 while (args.nonEmpty() && forms.nonEmpty()) {
772 // exact type arguments needs to know their
773 // bounds (for upper and lower bound
774 // calculations). So we create new TypeVars with
775 // bounds substed with actuals.
776 tvars_buf.append(types.substBound(((TypeVar)forms.head),
777 formals,
778 actuals));
779 args = args.tail;
780 forms = forms.tail;
781 }
783 args = type.getTypeArguments();
784 List<Type> tvars_cap = types.substBounds(formals,
785 formals,
786 types.capture(type).allparams());
787 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
788 // Let the actual arguments know their bound
789 args.head.withTypeVar((TypeVar)tvars_cap.head);
790 args = args.tail;
791 tvars_cap = tvars_cap.tail;
792 }
794 args = type.getTypeArguments();
795 List<Type> tvars = tvars_buf.toList();
797 while (args.nonEmpty() && tvars.nonEmpty()) {
798 Type actual = types.subst(args.head,
799 type.tsym.type.getTypeArguments(),
800 tvars_buf.toList());
801 if (!isTypeArgErroneous(actual) &&
802 !tvars.head.getUpperBound().isErroneous() &&
803 !checkExtends(actual, (TypeVar)tvars.head)) {
804 return args.head;
805 }
806 args = args.tail;
807 tvars = tvars.tail;
808 }
810 args = type.getTypeArguments();
811 tvars = tvars_buf.toList();
813 for (Type arg : types.capture(type).getTypeArguments()) {
814 if (arg.tag == TYPEVAR &&
815 arg.getUpperBound().isErroneous() &&
816 !tvars.head.getUpperBound().isErroneous() &&
817 !isTypeArgErroneous(args.head)) {
818 return args.head;
819 }
820 tvars = tvars.tail;
821 args = args.tail;
822 }
824 return null;
825 }
826 //where
827 boolean isTypeArgErroneous(Type t) {
828 return isTypeArgErroneous.visit(t);
829 }
831 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() {
832 public Boolean visitType(Type t, Void s) {
833 return t.isErroneous();
834 }
835 @Override
836 public Boolean visitTypeVar(TypeVar t, Void s) {
837 return visit(t.getUpperBound());
838 }
839 @Override
840 public Boolean visitCapturedType(CapturedType t, Void s) {
841 return visit(t.getUpperBound()) ||
842 visit(t.getLowerBound());
843 }
844 @Override
845 public Boolean visitWildcardType(WildcardType t, Void s) {
846 return visit(t.type);
847 }
848 };
850 /** Check that given modifiers are legal for given symbol and
851 * return modifiers together with any implicit modififiers for that symbol.
852 * Warning: we can't use flags() here since this method
853 * is called during class enter, when flags() would cause a premature
854 * completion.
855 * @param pos Position to be used for error reporting.
856 * @param flags The set of modifiers given in a definition.
857 * @param sym The defined symbol.
858 */
859 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
860 long mask;
861 long implicit = 0;
862 switch (sym.kind) {
863 case VAR:
864 if (sym.owner.kind != TYP)
865 mask = LocalVarFlags;
866 else if ((sym.owner.flags_field & INTERFACE) != 0)
867 mask = implicit = InterfaceVarFlags;
868 else
869 mask = VarFlags;
870 break;
871 case MTH:
872 if (sym.name == names.init) {
873 if ((sym.owner.flags_field & ENUM) != 0) {
874 // enum constructors cannot be declared public or
875 // protected and must be implicitly or explicitly
876 // private
877 implicit = PRIVATE;
878 mask = PRIVATE;
879 } else
880 mask = ConstructorFlags;
881 } else if ((sym.owner.flags_field & INTERFACE) != 0)
882 mask = implicit = InterfaceMethodFlags;
883 else {
884 mask = MethodFlags;
885 }
886 // Imply STRICTFP if owner has STRICTFP set.
887 if (((flags|implicit) & Flags.ABSTRACT) == 0)
888 implicit |= sym.owner.flags_field & STRICTFP;
889 break;
890 case TYP:
891 if (sym.isLocal()) {
892 mask = LocalClassFlags;
893 if (sym.name.isEmpty()) { // Anonymous class
894 // Anonymous classes in static methods are themselves static;
895 // that's why we admit STATIC here.
896 mask |= STATIC;
897 // JLS: Anonymous classes are final.
898 implicit |= FINAL;
899 }
900 if ((sym.owner.flags_field & STATIC) == 0 &&
901 (flags & ENUM) != 0)
902 log.error(pos, "enums.must.be.static");
903 } else if (sym.owner.kind == TYP) {
904 mask = MemberClassFlags;
905 if (sym.owner.owner.kind == PCK ||
906 (sym.owner.flags_field & STATIC) != 0)
907 mask |= STATIC;
908 else if ((flags & ENUM) != 0)
909 log.error(pos, "enums.must.be.static");
910 // Nested interfaces and enums are always STATIC (Spec ???)
911 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
912 } else {
913 mask = ClassFlags;
914 }
915 // Interfaces are always ABSTRACT
916 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
918 if ((flags & ENUM) != 0) {
919 // enums can't be declared abstract or final
920 mask &= ~(ABSTRACT | FINAL);
921 implicit |= implicitEnumFinalFlag(tree);
922 }
923 // Imply STRICTFP if owner has STRICTFP set.
924 implicit |= sym.owner.flags_field & STRICTFP;
925 break;
926 default:
927 throw new AssertionError();
928 }
929 long illegal = flags & StandardFlags & ~mask;
930 if (illegal != 0) {
931 if ((illegal & INTERFACE) != 0) {
932 log.error(pos, "intf.not.allowed.here");
933 mask |= INTERFACE;
934 }
935 else {
936 log.error(pos,
937 "mod.not.allowed.here", asFlagSet(illegal));
938 }
939 }
940 else if ((sym.kind == TYP ||
941 // ISSUE: Disallowing abstract&private is no longer appropriate
942 // in the presence of inner classes. Should it be deleted here?
943 checkDisjoint(pos, flags,
944 ABSTRACT,
945 PRIVATE | STATIC))
946 &&
947 checkDisjoint(pos, flags,
948 ABSTRACT | INTERFACE,
949 FINAL | NATIVE | SYNCHRONIZED)
950 &&
951 checkDisjoint(pos, flags,
952 PUBLIC,
953 PRIVATE | PROTECTED)
954 &&
955 checkDisjoint(pos, flags,
956 PRIVATE,
957 PUBLIC | PROTECTED)
958 &&
959 checkDisjoint(pos, flags,
960 FINAL,
961 VOLATILE)
962 &&
963 (sym.kind == TYP ||
964 checkDisjoint(pos, flags,
965 ABSTRACT | NATIVE,
966 STRICTFP))) {
967 // skip
968 }
969 return flags & (mask | ~StandardFlags) | implicit;
970 }
973 /** Determine if this enum should be implicitly final.
974 *
975 * If the enum has no specialized enum contants, it is final.
976 *
977 * If the enum does have specialized enum contants, it is
978 * <i>not</i> final.
979 */
980 private long implicitEnumFinalFlag(JCTree tree) {
981 if (tree.getTag() != JCTree.CLASSDEF) return 0;
982 class SpecialTreeVisitor extends JCTree.Visitor {
983 boolean specialized;
984 SpecialTreeVisitor() {
985 this.specialized = false;
986 };
988 @Override
989 public void visitTree(JCTree tree) { /* no-op */ }
991 @Override
992 public void visitVarDef(JCVariableDecl tree) {
993 if ((tree.mods.flags & ENUM) != 0) {
994 if (tree.init instanceof JCNewClass &&
995 ((JCNewClass) tree.init).def != null) {
996 specialized = true;
997 }
998 }
999 }
1000 }
1002 SpecialTreeVisitor sts = new SpecialTreeVisitor();
1003 JCClassDecl cdef = (JCClassDecl) tree;
1004 for (JCTree defs: cdef.defs) {
1005 defs.accept(sts);
1006 if (sts.specialized) return 0;
1007 }
1008 return FINAL;
1009 }
1011 /* *************************************************************************
1012 * Type Validation
1013 **************************************************************************/
1015 /** Validate a type expression. That is,
1016 * check that all type arguments of a parametric type are within
1017 * their bounds. This must be done in a second phase after type attributon
1018 * since a class might have a subclass as type parameter bound. E.g:
1019 *
1020 * class B<A extends C> { ... }
1021 * class C extends B<C> { ... }
1022 *
1023 * and we can't make sure that the bound is already attributed because
1024 * of possible cycles.
1025 *
1026 * Visitor method: Validate a type expression, if it is not null, catching
1027 * and reporting any completion failures.
1028 */
1029 void validate(JCTree tree, Env<AttrContext> env) {
1030 validate(tree, env, true);
1031 }
1032 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1033 new Validator(env).validateTree(tree, checkRaw, true);
1034 }
1036 /** Visitor method: Validate a list of type expressions.
1037 */
1038 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1039 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1040 validate(l.head, env);
1041 }
1043 /** A visitor class for type validation.
1044 */
1045 class Validator extends JCTree.Visitor {
1047 boolean isOuter;
1048 Env<AttrContext> env;
1050 Validator(Env<AttrContext> env) {
1051 this.env = env;
1052 }
1054 @Override
1055 public void visitTypeArray(JCArrayTypeTree tree) {
1056 tree.elemtype.accept(this);
1057 }
1059 @Override
1060 public void visitTypeApply(JCTypeApply tree) {
1061 if (tree.type.tag == CLASS) {
1062 List<JCExpression> args = tree.arguments;
1063 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1065 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1066 if (incompatibleArg != null) {
1067 for (JCTree arg : tree.arguments) {
1068 if (arg.type == incompatibleArg) {
1069 log.error(arg, "not.within.bounds", incompatibleArg, forms.head);
1070 }
1071 forms = forms.tail;
1072 }
1073 }
1075 forms = tree.type.tsym.type.getTypeArguments();
1077 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1079 // For matching pairs of actual argument types `a' and
1080 // formal type parameters with declared bound `b' ...
1081 while (args.nonEmpty() && forms.nonEmpty()) {
1082 validateTree(args.head,
1083 !(isOuter && is_java_lang_Class),
1084 false);
1085 args = args.tail;
1086 forms = forms.tail;
1087 }
1089 // Check that this type is either fully parameterized, or
1090 // not parameterized at all.
1091 if (tree.type.getEnclosingType().isRaw())
1092 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
1093 if (tree.clazz.getTag() == JCTree.SELECT)
1094 visitSelectInternal((JCFieldAccess)tree.clazz);
1095 }
1096 }
1098 @Override
1099 public void visitTypeParameter(JCTypeParameter tree) {
1100 validateTrees(tree.bounds, true, isOuter);
1101 checkClassBounds(tree.pos(), tree.type);
1102 }
1104 @Override
1105 public void visitWildcard(JCWildcard tree) {
1106 if (tree.inner != null)
1107 validateTree(tree.inner, true, isOuter);
1108 }
1110 @Override
1111 public void visitSelect(JCFieldAccess tree) {
1112 if (tree.type.tag == CLASS) {
1113 visitSelectInternal(tree);
1115 // Check that this type is either fully parameterized, or
1116 // not parameterized at all.
1117 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1118 log.error(tree.pos(), "improperly.formed.type.param.missing");
1119 }
1120 }
1122 public void visitSelectInternal(JCFieldAccess tree) {
1123 if (tree.type.tsym.isStatic() &&
1124 tree.selected.type.isParameterized()) {
1125 // The enclosing type is not a class, so we are
1126 // looking at a static member type. However, the
1127 // qualifying expression is parameterized.
1128 log.error(tree.pos(), "cant.select.static.class.from.param.type");
1129 } else {
1130 // otherwise validate the rest of the expression
1131 tree.selected.accept(this);
1132 }
1133 }
1135 /** Default visitor method: do nothing.
1136 */
1137 @Override
1138 public void visitTree(JCTree tree) {
1139 }
1141 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1142 try {
1143 if (tree != null) {
1144 this.isOuter = isOuter;
1145 tree.accept(this);
1146 if (checkRaw)
1147 checkRaw(tree, env);
1148 }
1149 } catch (CompletionFailure ex) {
1150 completionError(tree.pos(), ex);
1151 }
1152 }
1154 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1155 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1156 validateTree(l.head, checkRaw, isOuter);
1157 }
1159 void checkRaw(JCTree tree, Env<AttrContext> env) {
1160 if (lint.isEnabled(LintCategory.RAW) &&
1161 tree.type.tag == CLASS &&
1162 !TreeInfo.isDiamond(tree) &&
1163 !env.enclClass.name.isEmpty() && //anonymous or intersection
1164 tree.type.isRaw()) {
1165 log.warning(LintCategory.RAW,
1166 tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
1167 }
1168 }
1169 }
1171 /* *************************************************************************
1172 * Exception checking
1173 **************************************************************************/
1175 /* The following methods treat classes as sets that contain
1176 * the class itself and all their subclasses
1177 */
1179 /** Is given type a subtype of some of the types in given list?
1180 */
1181 boolean subset(Type t, List<Type> ts) {
1182 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1183 if (types.isSubtype(t, l.head)) return true;
1184 return false;
1185 }
1187 /** Is given type a subtype or supertype of
1188 * some of the types in given list?
1189 */
1190 boolean intersects(Type t, List<Type> ts) {
1191 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1192 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1193 return false;
1194 }
1196 /** Add type set to given type list, unless it is a subclass of some class
1197 * in the list.
1198 */
1199 List<Type> incl(Type t, List<Type> ts) {
1200 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1201 }
1203 /** Remove type set from type set list.
1204 */
1205 List<Type> excl(Type t, List<Type> ts) {
1206 if (ts.isEmpty()) {
1207 return ts;
1208 } else {
1209 List<Type> ts1 = excl(t, ts.tail);
1210 if (types.isSubtype(ts.head, t)) return ts1;
1211 else if (ts1 == ts.tail) return ts;
1212 else return ts1.prepend(ts.head);
1213 }
1214 }
1216 /** Form the union of two type set lists.
1217 */
1218 List<Type> union(List<Type> ts1, List<Type> ts2) {
1219 List<Type> ts = ts1;
1220 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1221 ts = incl(l.head, ts);
1222 return ts;
1223 }
1225 /** Form the difference of two type lists.
1226 */
1227 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1228 List<Type> ts = ts1;
1229 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1230 ts = excl(l.head, ts);
1231 return ts;
1232 }
1234 /** Form the intersection of two type lists.
1235 */
1236 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1237 List<Type> ts = List.nil();
1238 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1239 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1240 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1241 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1242 return ts;
1243 }
1245 /** Is exc an exception symbol that need not be declared?
1246 */
1247 boolean isUnchecked(ClassSymbol exc) {
1248 return
1249 exc.kind == ERR ||
1250 exc.isSubClass(syms.errorType.tsym, types) ||
1251 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1252 }
1254 /** Is exc an exception type that need not be declared?
1255 */
1256 boolean isUnchecked(Type exc) {
1257 return
1258 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
1259 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
1260 exc.tag == BOT;
1261 }
1263 /** Same, but handling completion failures.
1264 */
1265 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1266 try {
1267 return isUnchecked(exc);
1268 } catch (CompletionFailure ex) {
1269 completionError(pos, ex);
1270 return true;
1271 }
1272 }
1274 /** Is exc handled by given exception list?
1275 */
1276 boolean isHandled(Type exc, List<Type> handled) {
1277 return isUnchecked(exc) || subset(exc, handled);
1278 }
1280 /** Return all exceptions in thrown list that are not in handled list.
1281 * @param thrown The list of thrown exceptions.
1282 * @param handled The list of handled exceptions.
1283 */
1284 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1285 List<Type> unhandled = List.nil();
1286 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1287 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1288 return unhandled;
1289 }
1291 /* *************************************************************************
1292 * Overriding/Implementation checking
1293 **************************************************************************/
1295 /** The level of access protection given by a flag set,
1296 * where PRIVATE is highest and PUBLIC is lowest.
1297 */
1298 static int protection(long flags) {
1299 switch ((short)(flags & AccessFlags)) {
1300 case PRIVATE: return 3;
1301 case PROTECTED: return 1;
1302 default:
1303 case PUBLIC: return 0;
1304 case 0: return 2;
1305 }
1306 }
1308 /** A customized "cannot override" error message.
1309 * @param m The overriding method.
1310 * @param other The overridden method.
1311 * @return An internationalized string.
1312 */
1313 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1314 String key;
1315 if ((other.owner.flags() & INTERFACE) == 0)
1316 key = "cant.override";
1317 else if ((m.owner.flags() & INTERFACE) == 0)
1318 key = "cant.implement";
1319 else
1320 key = "clashes.with";
1321 return diags.fragment(key, m, m.location(), other, other.location());
1322 }
1324 /** A customized "override" warning message.
1325 * @param m The overriding method.
1326 * @param other The overridden method.
1327 * @return An internationalized string.
1328 */
1329 Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1330 String key;
1331 if ((other.owner.flags() & INTERFACE) == 0)
1332 key = "unchecked.override";
1333 else if ((m.owner.flags() & INTERFACE) == 0)
1334 key = "unchecked.implement";
1335 else
1336 key = "unchecked.clash.with";
1337 return diags.fragment(key, m, m.location(), other, other.location());
1338 }
1340 /** A customized "override" warning message.
1341 * @param m The overriding method.
1342 * @param other The overridden method.
1343 * @return An internationalized string.
1344 */
1345 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1346 String key;
1347 if ((other.owner.flags() & INTERFACE) == 0)
1348 key = "varargs.override";
1349 else if ((m.owner.flags() & INTERFACE) == 0)
1350 key = "varargs.implement";
1351 else
1352 key = "varargs.clash.with";
1353 return diags.fragment(key, m, m.location(), other, other.location());
1354 }
1356 /** Check that this method conforms with overridden method 'other'.
1357 * where `origin' is the class where checking started.
1358 * Complications:
1359 * (1) Do not check overriding of synthetic methods
1360 * (reason: they might be final).
1361 * todo: check whether this is still necessary.
1362 * (2) Admit the case where an interface proxy throws fewer exceptions
1363 * than the method it implements. Augment the proxy methods with the
1364 * undeclared exceptions in this case.
1365 * (3) When generics are enabled, admit the case where an interface proxy
1366 * has a result type
1367 * extended by the result type of the method it implements.
1368 * Change the proxies result type to the smaller type in this case.
1369 *
1370 * @param tree The tree from which positions
1371 * are extracted for errors.
1372 * @param m The overriding method.
1373 * @param other The overridden method.
1374 * @param origin The class of which the overriding method
1375 * is a member.
1376 */
1377 void checkOverride(JCTree tree,
1378 MethodSymbol m,
1379 MethodSymbol other,
1380 ClassSymbol origin) {
1381 // Don't check overriding of synthetic methods or by bridge methods.
1382 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1383 return;
1384 }
1386 // Error if static method overrides instance method (JLS 8.4.6.2).
1387 if ((m.flags() & STATIC) != 0 &&
1388 (other.flags() & STATIC) == 0) {
1389 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1390 cannotOverride(m, other));
1391 return;
1392 }
1394 // Error if instance method overrides static or final
1395 // method (JLS 8.4.6.1).
1396 if ((other.flags() & FINAL) != 0 ||
1397 (m.flags() & STATIC) == 0 &&
1398 (other.flags() & STATIC) != 0) {
1399 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1400 cannotOverride(m, other),
1401 asFlagSet(other.flags() & (FINAL | STATIC)));
1402 return;
1403 }
1405 if ((m.owner.flags() & ANNOTATION) != 0) {
1406 // handled in validateAnnotationMethod
1407 return;
1408 }
1410 // Error if overriding method has weaker access (JLS 8.4.6.3).
1411 if ((origin.flags() & INTERFACE) == 0 &&
1412 protection(m.flags()) > protection(other.flags())) {
1413 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1414 cannotOverride(m, other),
1415 other.flags() == 0 ?
1416 Flag.PACKAGE :
1417 asFlagSet(other.flags() & AccessFlags));
1418 return;
1419 }
1421 Type mt = types.memberType(origin.type, m);
1422 Type ot = types.memberType(origin.type, other);
1423 // Error if overriding result type is different
1424 // (or, in the case of generics mode, not a subtype) of
1425 // overridden result type. We have to rename any type parameters
1426 // before comparing types.
1427 List<Type> mtvars = mt.getTypeArguments();
1428 List<Type> otvars = ot.getTypeArguments();
1429 Type mtres = mt.getReturnType();
1430 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1432 overrideWarner.clear();
1433 boolean resultTypesOK =
1434 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1435 if (!resultTypesOK) {
1436 if (!allowCovariantReturns &&
1437 m.owner != origin &&
1438 m.owner.isSubClass(other.owner, types)) {
1439 // allow limited interoperability with covariant returns
1440 } else {
1441 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1442 "override.incompatible.ret",
1443 cannotOverride(m, other),
1444 mtres, otres);
1445 return;
1446 }
1447 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1448 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1449 "override.unchecked.ret",
1450 uncheckedOverrides(m, other),
1451 mtres, otres);
1452 }
1454 // Error if overriding method throws an exception not reported
1455 // by overridden method.
1456 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1457 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1458 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1459 if (unhandledErased.nonEmpty()) {
1460 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1461 "override.meth.doesnt.throw",
1462 cannotOverride(m, other),
1463 unhandledUnerased.head);
1464 return;
1465 }
1466 else if (unhandledUnerased.nonEmpty()) {
1467 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1468 "override.unchecked.thrown",
1469 cannotOverride(m, other),
1470 unhandledUnerased.head);
1471 return;
1472 }
1474 // Optional warning if varargs don't agree
1475 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1476 && lint.isEnabled(LintCategory.OVERRIDES)) {
1477 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1478 ((m.flags() & Flags.VARARGS) != 0)
1479 ? "override.varargs.missing"
1480 : "override.varargs.extra",
1481 varargsOverrides(m, other));
1482 }
1484 // Warn if instance method overrides bridge method (compiler spec ??)
1485 if ((other.flags() & BRIDGE) != 0) {
1486 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1487 uncheckedOverrides(m, other));
1488 }
1490 // Warn if a deprecated method overridden by a non-deprecated one.
1491 if (!isDeprecatedOverrideIgnorable(other, origin)) {
1492 checkDeprecated(TreeInfo.diagnosticPositionFor(m, tree), m, other);
1493 }
1494 }
1495 // where
1496 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1497 // If the method, m, is defined in an interface, then ignore the issue if the method
1498 // is only inherited via a supertype and also implemented in the supertype,
1499 // because in that case, we will rediscover the issue when examining the method
1500 // in the supertype.
1501 // If the method, m, is not defined in an interface, then the only time we need to
1502 // address the issue is when the method is the supertype implemementation: any other
1503 // case, we will have dealt with when examining the supertype classes
1504 ClassSymbol mc = m.enclClass();
1505 Type st = types.supertype(origin.type);
1506 if (st.tag != CLASS)
1507 return true;
1508 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1510 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1511 List<Type> intfs = types.interfaces(origin.type);
1512 return (intfs.contains(mc.type) ? false : (stimpl != null));
1513 }
1514 else
1515 return (stimpl != m);
1516 }
1519 // used to check if there were any unchecked conversions
1520 Warner overrideWarner = new Warner();
1522 /** Check that a class does not inherit two concrete methods
1523 * with the same signature.
1524 * @param pos Position to be used for error reporting.
1525 * @param site The class type to be checked.
1526 */
1527 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1528 Type sup = types.supertype(site);
1529 if (sup.tag != CLASS) return;
1531 for (Type t1 = sup;
1532 t1.tsym.type.isParameterized();
1533 t1 = types.supertype(t1)) {
1534 for (Scope.Entry e1 = t1.tsym.members().elems;
1535 e1 != null;
1536 e1 = e1.sibling) {
1537 Symbol s1 = e1.sym;
1538 if (s1.kind != MTH ||
1539 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1540 !s1.isInheritedIn(site.tsym, types) ||
1541 ((MethodSymbol)s1).implementation(site.tsym,
1542 types,
1543 true) != s1)
1544 continue;
1545 Type st1 = types.memberType(t1, s1);
1546 int s1ArgsLength = st1.getParameterTypes().length();
1547 if (st1 == s1.type) continue;
1549 for (Type t2 = sup;
1550 t2.tag == CLASS;
1551 t2 = types.supertype(t2)) {
1552 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1553 e2.scope != null;
1554 e2 = e2.next()) {
1555 Symbol s2 = e2.sym;
1556 if (s2 == s1 ||
1557 s2.kind != MTH ||
1558 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1559 s2.type.getParameterTypes().length() != s1ArgsLength ||
1560 !s2.isInheritedIn(site.tsym, types) ||
1561 ((MethodSymbol)s2).implementation(site.tsym,
1562 types,
1563 true) != s2)
1564 continue;
1565 Type st2 = types.memberType(t2, s2);
1566 if (types.overrideEquivalent(st1, st2))
1567 log.error(pos, "concrete.inheritance.conflict",
1568 s1, t1, s2, t2, sup);
1569 }
1570 }
1571 }
1572 }
1573 }
1575 /** Check that classes (or interfaces) do not each define an abstract
1576 * method with same name and arguments but incompatible return types.
1577 * @param pos Position to be used for error reporting.
1578 * @param t1 The first argument type.
1579 * @param t2 The second argument type.
1580 */
1581 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1582 Type t1,
1583 Type t2) {
1584 return checkCompatibleAbstracts(pos, t1, t2,
1585 types.makeCompoundType(t1, t2));
1586 }
1588 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1589 Type t1,
1590 Type t2,
1591 Type site) {
1592 return firstIncompatibility(pos, t1, t2, site) == null;
1593 }
1595 /** Return the first method which is defined with same args
1596 * but different return types in two given interfaces, or null if none
1597 * exists.
1598 * @param t1 The first type.
1599 * @param t2 The second type.
1600 * @param site The most derived type.
1601 * @returns symbol from t2 that conflicts with one in t1.
1602 */
1603 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1604 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1605 closure(t1, interfaces1);
1606 Map<TypeSymbol,Type> interfaces2;
1607 if (t1 == t2)
1608 interfaces2 = interfaces1;
1609 else
1610 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1612 for (Type t3 : interfaces1.values()) {
1613 for (Type t4 : interfaces2.values()) {
1614 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
1615 if (s != null) return s;
1616 }
1617 }
1618 return null;
1619 }
1621 /** Compute all the supertypes of t, indexed by type symbol. */
1622 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1623 if (t.tag != CLASS) return;
1624 if (typeMap.put(t.tsym, t) == null) {
1625 closure(types.supertype(t), typeMap);
1626 for (Type i : types.interfaces(t))
1627 closure(i, typeMap);
1628 }
1629 }
1631 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1632 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1633 if (t.tag != CLASS) return;
1634 if (typesSkip.get(t.tsym) != null) return;
1635 if (typeMap.put(t.tsym, t) == null) {
1636 closure(types.supertype(t), typesSkip, typeMap);
1637 for (Type i : types.interfaces(t))
1638 closure(i, typesSkip, typeMap);
1639 }
1640 }
1642 /** Return the first method in t2 that conflicts with a method from t1. */
1643 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1644 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1645 Symbol s1 = e1.sym;
1646 Type st1 = null;
1647 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1648 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1649 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1650 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1651 Symbol s2 = e2.sym;
1652 if (s1 == s2) continue;
1653 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1654 if (st1 == null) st1 = types.memberType(t1, s1);
1655 Type st2 = types.memberType(t2, s2);
1656 if (types.overrideEquivalent(st1, st2)) {
1657 List<Type> tvars1 = st1.getTypeArguments();
1658 List<Type> tvars2 = st2.getTypeArguments();
1659 Type rt1 = st1.getReturnType();
1660 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1661 boolean compat =
1662 types.isSameType(rt1, rt2) ||
1663 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1664 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1665 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1666 checkCommonOverriderIn(s1,s2,site);
1667 if (!compat) {
1668 log.error(pos, "types.incompatible.diff.ret",
1669 t1, t2, s2.name +
1670 "(" + types.memberType(t2, s2).getParameterTypes() + ")");
1671 return s2;
1672 }
1673 } else if (checkNameClash((ClassSymbol)site.tsym, s1, s2) &&
1674 !checkCommonOverriderIn(s1, s2, site)) {
1675 log.error(pos,
1676 "name.clash.same.erasure.no.override",
1677 s1, s1.location(),
1678 s2, s2.location());
1679 return s2;
1680 }
1681 }
1682 }
1683 return null;
1684 }
1685 //WHERE
1686 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1687 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1688 Type st1 = types.memberType(site, s1);
1689 Type st2 = types.memberType(site, s2);
1690 closure(site, supertypes);
1691 for (Type t : supertypes.values()) {
1692 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1693 Symbol s3 = e.sym;
1694 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1695 Type st3 = types.memberType(site,s3);
1696 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1697 if (s3.owner == site.tsym) {
1698 return true;
1699 }
1700 List<Type> tvars1 = st1.getTypeArguments();
1701 List<Type> tvars2 = st2.getTypeArguments();
1702 List<Type> tvars3 = st3.getTypeArguments();
1703 Type rt1 = st1.getReturnType();
1704 Type rt2 = st2.getReturnType();
1705 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1706 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1707 boolean compat =
1708 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1709 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1710 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1711 if (compat)
1712 return true;
1713 }
1714 }
1715 }
1716 return false;
1717 }
1719 /** Check that a given method conforms with any method it overrides.
1720 * @param tree The tree from which positions are extracted
1721 * for errors.
1722 * @param m The overriding method.
1723 */
1724 void checkOverride(JCTree tree, MethodSymbol m) {
1725 ClassSymbol origin = (ClassSymbol)m.owner;
1726 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1727 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1728 log.error(tree.pos(), "enum.no.finalize");
1729 return;
1730 }
1731 for (Type t = origin.type; t.tag == CLASS;
1732 t = types.supertype(t)) {
1733 if (t != origin.type) {
1734 checkOverride(tree, t, origin, m);
1735 }
1736 for (Type t2 : types.interfaces(t)) {
1737 checkOverride(tree, t2, origin, m);
1738 }
1739 }
1740 }
1742 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
1743 TypeSymbol c = site.tsym;
1744 Scope.Entry e = c.members().lookup(m.name);
1745 while (e.scope != null) {
1746 if (m.overrides(e.sym, origin, types, false)) {
1747 if ((e.sym.flags() & ABSTRACT) == 0) {
1748 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1749 }
1750 }
1751 e = e.next();
1752 }
1753 }
1755 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
1756 ClashFilter cf = new ClashFilter(origin.type);
1757 return (cf.accepts(s1) &&
1758 cf.accepts(s2) &&
1759 types.hasSameArgs(s1.erasure(types), s2.erasure(types)));
1760 }
1763 /** Check that all abstract members of given class have definitions.
1764 * @param pos Position to be used for error reporting.
1765 * @param c The class.
1766 */
1767 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1768 try {
1769 MethodSymbol undef = firstUndef(c, c);
1770 if (undef != null) {
1771 if ((c.flags() & ENUM) != 0 &&
1772 types.supertype(c.type).tsym == syms.enumSym &&
1773 (c.flags() & FINAL) == 0) {
1774 // add the ABSTRACT flag to an enum
1775 c.flags_field |= ABSTRACT;
1776 } else {
1777 MethodSymbol undef1 =
1778 new MethodSymbol(undef.flags(), undef.name,
1779 types.memberType(c.type, undef), undef.owner);
1780 log.error(pos, "does.not.override.abstract",
1781 c, undef1, undef1.location());
1782 }
1783 }
1784 } catch (CompletionFailure ex) {
1785 completionError(pos, ex);
1786 }
1787 }
1788 //where
1789 /** Return first abstract member of class `c' that is not defined
1790 * in `impl', null if there is none.
1791 */
1792 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1793 MethodSymbol undef = null;
1794 // Do not bother to search in classes that are not abstract,
1795 // since they cannot have abstract members.
1796 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1797 Scope s = c.members();
1798 for (Scope.Entry e = s.elems;
1799 undef == null && e != null;
1800 e = e.sibling) {
1801 if (e.sym.kind == MTH &&
1802 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1803 MethodSymbol absmeth = (MethodSymbol)e.sym;
1804 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1805 if (implmeth == null || implmeth == absmeth)
1806 undef = absmeth;
1807 }
1808 }
1809 if (undef == null) {
1810 Type st = types.supertype(c.type);
1811 if (st.tag == CLASS)
1812 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1813 }
1814 for (List<Type> l = types.interfaces(c.type);
1815 undef == null && l.nonEmpty();
1816 l = l.tail) {
1817 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1818 }
1819 }
1820 return undef;
1821 }
1823 void checkNonCyclicDecl(JCClassDecl tree) {
1824 CycleChecker cc = new CycleChecker();
1825 cc.scan(tree);
1826 if (!cc.errorFound && !cc.partialCheck) {
1827 tree.sym.flags_field |= ACYCLIC;
1828 }
1829 }
1831 class CycleChecker extends TreeScanner {
1833 List<Symbol> seenClasses = List.nil();
1834 boolean errorFound = false;
1835 boolean partialCheck = false;
1837 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
1838 if (sym != null && sym.kind == TYP) {
1839 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
1840 if (classEnv != null) {
1841 DiagnosticSource prevSource = log.currentSource();
1842 try {
1843 log.useSource(classEnv.toplevel.sourcefile);
1844 scan(classEnv.tree);
1845 }
1846 finally {
1847 log.useSource(prevSource.getFile());
1848 }
1849 } else if (sym.kind == TYP) {
1850 checkClass(pos, sym, List.<JCTree>nil());
1851 }
1852 } else {
1853 //not completed yet
1854 partialCheck = true;
1855 }
1856 }
1858 @Override
1859 public void visitSelect(JCFieldAccess tree) {
1860 super.visitSelect(tree);
1861 checkSymbol(tree.pos(), tree.sym);
1862 }
1864 @Override
1865 public void visitIdent(JCIdent tree) {
1866 checkSymbol(tree.pos(), tree.sym);
1867 }
1869 @Override
1870 public void visitTypeApply(JCTypeApply tree) {
1871 scan(tree.clazz);
1872 }
1874 @Override
1875 public void visitTypeArray(JCArrayTypeTree tree) {
1876 scan(tree.elemtype);
1877 }
1879 @Override
1880 public void visitClassDef(JCClassDecl tree) {
1881 List<JCTree> supertypes = List.nil();
1882 if (tree.getExtendsClause() != null) {
1883 supertypes = supertypes.prepend(tree.getExtendsClause());
1884 }
1885 if (tree.getImplementsClause() != null) {
1886 for (JCTree intf : tree.getImplementsClause()) {
1887 supertypes = supertypes.prepend(intf);
1888 }
1889 }
1890 checkClass(tree.pos(), tree.sym, supertypes);
1891 }
1893 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
1894 if ((c.flags_field & ACYCLIC) != 0)
1895 return;
1896 if (seenClasses.contains(c)) {
1897 errorFound = true;
1898 noteCyclic(pos, (ClassSymbol)c);
1899 } else if (!c.type.isErroneous()) {
1900 try {
1901 seenClasses = seenClasses.prepend(c);
1902 if (c.type.tag == CLASS) {
1903 if (supertypes.nonEmpty()) {
1904 scan(supertypes);
1905 }
1906 else {
1907 ClassType ct = (ClassType)c.type;
1908 if (ct.supertype_field == null ||
1909 ct.interfaces_field == null) {
1910 //not completed yet
1911 partialCheck = true;
1912 return;
1913 }
1914 checkSymbol(pos, ct.supertype_field.tsym);
1915 for (Type intf : ct.interfaces_field) {
1916 checkSymbol(pos, intf.tsym);
1917 }
1918 }
1919 if (c.owner.kind == TYP) {
1920 checkSymbol(pos, c.owner);
1921 }
1922 }
1923 } finally {
1924 seenClasses = seenClasses.tail;
1925 }
1926 }
1927 }
1928 }
1930 /** Check for cyclic references. Issue an error if the
1931 * symbol of the type referred to has a LOCKED flag set.
1932 *
1933 * @param pos Position to be used for error reporting.
1934 * @param t The type referred to.
1935 */
1936 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1937 checkNonCyclicInternal(pos, t);
1938 }
1941 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1942 checkNonCyclic1(pos, t, List.<TypeVar>nil());
1943 }
1945 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
1946 final TypeVar tv;
1947 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
1948 return;
1949 if (seen.contains(t)) {
1950 tv = (TypeVar)t;
1951 tv.bound = types.createErrorType(t);
1952 log.error(pos, "cyclic.inheritance", t);
1953 } else if (t.tag == TYPEVAR) {
1954 tv = (TypeVar)t;
1955 seen = seen.prepend(tv);
1956 for (Type b : types.getBounds(tv))
1957 checkNonCyclic1(pos, b, seen);
1958 }
1959 }
1961 /** Check for cyclic references. Issue an error if the
1962 * symbol of the type referred to has a LOCKED flag set.
1963 *
1964 * @param pos Position to be used for error reporting.
1965 * @param t The type referred to.
1966 * @returns True if the check completed on all attributed classes
1967 */
1968 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1969 boolean complete = true; // was the check complete?
1970 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1971 Symbol c = t.tsym;
1972 if ((c.flags_field & ACYCLIC) != 0) return true;
1974 if ((c.flags_field & LOCKED) != 0) {
1975 noteCyclic(pos, (ClassSymbol)c);
1976 } else if (!c.type.isErroneous()) {
1977 try {
1978 c.flags_field |= LOCKED;
1979 if (c.type.tag == CLASS) {
1980 ClassType clazz = (ClassType)c.type;
1981 if (clazz.interfaces_field != null)
1982 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1983 complete &= checkNonCyclicInternal(pos, l.head);
1984 if (clazz.supertype_field != null) {
1985 Type st = clazz.supertype_field;
1986 if (st != null && st.tag == CLASS)
1987 complete &= checkNonCyclicInternal(pos, st);
1988 }
1989 if (c.owner.kind == TYP)
1990 complete &= checkNonCyclicInternal(pos, c.owner.type);
1991 }
1992 } finally {
1993 c.flags_field &= ~LOCKED;
1994 }
1995 }
1996 if (complete)
1997 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
1998 if (complete) c.flags_field |= ACYCLIC;
1999 return complete;
2000 }
2002 /** Note that we found an inheritance cycle. */
2003 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
2004 log.error(pos, "cyclic.inheritance", c);
2005 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
2006 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
2007 Type st = types.supertype(c.type);
2008 if (st.tag == CLASS)
2009 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2010 c.type = types.createErrorType(c, c.type);
2011 c.flags_field |= ACYCLIC;
2012 }
2014 /** Check that all methods which implement some
2015 * method conform to the method they implement.
2016 * @param tree The class definition whose members are checked.
2017 */
2018 void checkImplementations(JCClassDecl tree) {
2019 checkImplementations(tree, tree.sym);
2020 }
2021 //where
2022 /** Check that all methods which implement some
2023 * method in `ic' conform to the method they implement.
2024 */
2025 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
2026 ClassSymbol origin = tree.sym;
2027 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2028 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2029 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
2030 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
2031 if (e.sym.kind == MTH &&
2032 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2033 MethodSymbol absmeth = (MethodSymbol)e.sym;
2034 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2035 if (implmeth != null && implmeth != absmeth &&
2036 (implmeth.owner.flags() & INTERFACE) ==
2037 (origin.flags() & INTERFACE)) {
2038 // don't check if implmeth is in a class, yet
2039 // origin is an interface. This case arises only
2040 // if implmeth is declared in Object. The reason is
2041 // that interfaces really don't inherit from
2042 // Object it's just that the compiler represents
2043 // things that way.
2044 checkOverride(tree, implmeth, absmeth, origin);
2045 }
2046 }
2047 }
2048 }
2049 }
2050 }
2052 /** Check that all abstract methods implemented by a class are
2053 * mutually compatible.
2054 * @param pos Position to be used for error reporting.
2055 * @param c The class whose interfaces are checked.
2056 */
2057 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2058 List<Type> supertypes = types.interfaces(c);
2059 Type supertype = types.supertype(c);
2060 if (supertype.tag == CLASS &&
2061 (supertype.tsym.flags() & ABSTRACT) != 0)
2062 supertypes = supertypes.prepend(supertype);
2063 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2064 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
2065 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2066 return;
2067 for (List<Type> m = supertypes; m != l; m = m.tail)
2068 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2069 return;
2070 }
2071 checkCompatibleConcretes(pos, c);
2072 }
2074 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
2075 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
2076 for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
2077 // VM allows methods and variables with differing types
2078 if (sym.kind == e.sym.kind &&
2079 types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
2080 sym != e.sym &&
2081 (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
2082 (sym.flags() & IPROXY) == 0 && (e.sym.flags() & IPROXY) == 0 &&
2083 (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
2084 syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
2085 return;
2086 }
2087 }
2088 }
2089 }
2091 /** Check that all non-override equivalent methods accessible from 'site'
2092 * are mutually compatible (JLS 8.4.8/9.4.1).
2093 *
2094 * @param pos Position to be used for error reporting.
2095 * @param site The class whose methods are checked.
2096 * @param sym The method symbol to be checked.
2097 */
2098 void checkOverrideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2099 ClashFilter cf = new ClashFilter(site);
2100 //for each method m1 that is a member of 'site'...
2101 for (Symbol s1 : types.membersClosure(site).getElementsByName(sym.name, cf)) {
2102 //...find another method m2 that is overridden (directly or indirectly)
2103 //by method 'sym' in 'site'
2104 for (Symbol s2 : types.membersClosure(site).getElementsByName(sym.name, cf)) {
2105 if (s1 == s2 || !sym.overrides(s2, site.tsym, types, false)) continue;
2106 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2107 //a member of 'site') and (ii) m1 has the same erasure as m2, issue an error
2108 if (!types.isSubSignature(sym.type, types.memberType(site, s1), false) &&
2109 types.hasSameArgs(s1.erasure(types), s2.erasure(types))) {
2110 sym.flags_field |= CLASH;
2111 String key = s2 == sym ?
2112 "name.clash.same.erasure.no.override" :
2113 "name.clash.same.erasure.no.override.1";
2114 log.error(pos,
2115 key,
2116 sym, sym.location(),
2117 s1, s1.location(),
2118 s2, s2.location());
2119 return;
2120 }
2121 }
2122 }
2123 }
2127 /** Check that all static methods accessible from 'site' are
2128 * mutually compatible (JLS 8.4.8).
2129 *
2130 * @param pos Position to be used for error reporting.
2131 * @param site The class whose methods are checked.
2132 * @param sym The method symbol to be checked.
2133 */
2134 void checkHideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2135 ClashFilter cf = new ClashFilter(site);
2136 //for each method m1 that is a member of 'site'...
2137 for (Symbol s : types.membersClosure(site).getElementsByName(sym.name, cf)) {
2138 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2139 //a member of 'site') and (ii) 'sym' has the same erasure as m1, issue an error
2140 if (!types.isSubSignature(sym.type, types.memberType(site, s), false) &&
2141 types.hasSameArgs(s.erasure(types), sym.erasure(types))) {
2142 log.error(pos,
2143 "name.clash.same.erasure.no.hide",
2144 sym, sym.location(),
2145 s, s.location());
2146 return;
2147 }
2148 }
2149 }
2151 //where
2152 private class ClashFilter implements Filter<Symbol> {
2154 Type site;
2156 ClashFilter(Type site) {
2157 this.site = site;
2158 }
2160 boolean shouldSkip(Symbol s) {
2161 return (s.flags() & CLASH) != 0 &&
2162 s.owner == site.tsym;
2163 }
2165 public boolean accepts(Symbol s) {
2166 return s.kind == MTH &&
2167 (s.flags() & SYNTHETIC) == 0 &&
2168 !shouldSkip(s) &&
2169 s.isInheritedIn(site.tsym, types) &&
2170 !s.isConstructor();
2171 }
2172 }
2174 /** Report a conflict between a user symbol and a synthetic symbol.
2175 */
2176 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
2177 if (!sym.type.isErroneous()) {
2178 if (warnOnSyntheticConflicts) {
2179 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
2180 }
2181 else {
2182 log.error(pos, "synthetic.name.conflict", sym, sym.location());
2183 }
2184 }
2185 }
2187 /** Check that class c does not implement directly or indirectly
2188 * the same parameterized interface with two different argument lists.
2189 * @param pos Position to be used for error reporting.
2190 * @param type The type whose interfaces are checked.
2191 */
2192 void checkClassBounds(DiagnosticPosition pos, Type type) {
2193 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
2194 }
2195 //where
2196 /** Enter all interfaces of type `type' into the hash table `seensofar'
2197 * with their class symbol as key and their type as value. Make
2198 * sure no class is entered with two different types.
2199 */
2200 void checkClassBounds(DiagnosticPosition pos,
2201 Map<TypeSymbol,Type> seensofar,
2202 Type type) {
2203 if (type.isErroneous()) return;
2204 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
2205 Type it = l.head;
2206 Type oldit = seensofar.put(it.tsym, it);
2207 if (oldit != null) {
2208 List<Type> oldparams = oldit.allparams();
2209 List<Type> newparams = it.allparams();
2210 if (!types.containsTypeEquivalent(oldparams, newparams))
2211 log.error(pos, "cant.inherit.diff.arg",
2212 it.tsym, Type.toString(oldparams),
2213 Type.toString(newparams));
2214 }
2215 checkClassBounds(pos, seensofar, it);
2216 }
2217 Type st = types.supertype(type);
2218 if (st != null) checkClassBounds(pos, seensofar, st);
2219 }
2221 /** Enter interface into into set.
2222 * If it existed already, issue a "repeated interface" error.
2223 */
2224 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
2225 if (its.contains(it))
2226 log.error(pos, "repeated.interface");
2227 else {
2228 its.add(it);
2229 }
2230 }
2232 /* *************************************************************************
2233 * Check annotations
2234 **************************************************************************/
2236 /**
2237 * Recursively validate annotations values
2238 */
2239 void validateAnnotationTree(JCTree tree) {
2240 class AnnotationValidator extends TreeScanner {
2241 @Override
2242 public void visitAnnotation(JCAnnotation tree) {
2243 super.visitAnnotation(tree);
2244 validateAnnotation(tree);
2245 }
2246 }
2247 tree.accept(new AnnotationValidator());
2248 }
2250 /** Annotation types are restricted to primitives, String, an
2251 * enum, an annotation, Class, Class<?>, Class<? extends
2252 * Anything>, arrays of the preceding.
2253 */
2254 void validateAnnotationType(JCTree restype) {
2255 // restype may be null if an error occurred, so don't bother validating it
2256 if (restype != null) {
2257 validateAnnotationType(restype.pos(), restype.type);
2258 }
2259 }
2261 void validateAnnotationType(DiagnosticPosition pos, Type type) {
2262 if (type.isPrimitive()) return;
2263 if (types.isSameType(type, syms.stringType)) return;
2264 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
2265 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
2266 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
2267 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
2268 validateAnnotationType(pos, types.elemtype(type));
2269 return;
2270 }
2271 log.error(pos, "invalid.annotation.member.type");
2272 }
2274 /**
2275 * "It is also a compile-time error if any method declared in an
2276 * annotation type has a signature that is override-equivalent to
2277 * that of any public or protected method declared in class Object
2278 * or in the interface annotation.Annotation."
2279 *
2280 * @jls 9.6 Annotation Types
2281 */
2282 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
2283 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
2284 Scope s = sup.tsym.members();
2285 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
2286 if (e.sym.kind == MTH &&
2287 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
2288 types.overrideEquivalent(m.type, e.sym.type))
2289 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
2290 }
2291 }
2292 }
2294 /** Check the annotations of a symbol.
2295 */
2296 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
2297 if (skipAnnotations) return;
2298 for (JCAnnotation a : annotations)
2299 validateAnnotation(a, s);
2300 }
2302 /** Check an annotation of a symbol.
2303 */
2304 public void validateAnnotation(JCAnnotation a, Symbol s) {
2305 validateAnnotationTree(a);
2307 if (!annotationApplicable(a, s))
2308 log.error(a.pos(), "annotation.type.not.applicable");
2310 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2311 if (!isOverrider(s))
2312 log.error(a.pos(), "method.does.not.override.superclass");
2313 }
2314 }
2316 /** Is s a method symbol that overrides a method in a superclass? */
2317 boolean isOverrider(Symbol s) {
2318 if (s.kind != MTH || s.isStatic())
2319 return false;
2320 MethodSymbol m = (MethodSymbol)s;
2321 TypeSymbol owner = (TypeSymbol)m.owner;
2322 for (Type sup : types.closure(owner.type)) {
2323 if (sup == owner.type)
2324 continue; // skip "this"
2325 Scope scope = sup.tsym.members();
2326 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
2327 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
2328 return true;
2329 }
2330 }
2331 return false;
2332 }
2334 /** Is the annotation applicable to the symbol? */
2335 boolean annotationApplicable(JCAnnotation a, Symbol s) {
2336 Attribute.Compound atTarget =
2337 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
2338 if (atTarget == null) return true;
2339 Attribute atValue = atTarget.member(names.value);
2340 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
2341 Attribute.Array arr = (Attribute.Array) atValue;
2342 for (Attribute app : arr.values) {
2343 if (!(app instanceof Attribute.Enum)) return true; // recovery
2344 Attribute.Enum e = (Attribute.Enum) app;
2345 if (e.value.name == names.TYPE)
2346 { if (s.kind == TYP) return true; }
2347 else if (e.value.name == names.FIELD)
2348 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
2349 else if (e.value.name == names.METHOD)
2350 { if (s.kind == MTH && !s.isConstructor()) return true; }
2351 else if (e.value.name == names.PARAMETER)
2352 { if (s.kind == VAR &&
2353 s.owner.kind == MTH &&
2354 (s.flags() & PARAMETER) != 0)
2355 return true;
2356 }
2357 else if (e.value.name == names.CONSTRUCTOR)
2358 { if (s.kind == MTH && s.isConstructor()) return true; }
2359 else if (e.value.name == names.LOCAL_VARIABLE)
2360 { if (s.kind == VAR && s.owner.kind == MTH &&
2361 (s.flags() & PARAMETER) == 0)
2362 return true;
2363 }
2364 else if (e.value.name == names.ANNOTATION_TYPE)
2365 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
2366 return true;
2367 }
2368 else if (e.value.name == names.PACKAGE)
2369 { if (s.kind == PCK) return true; }
2370 else if (e.value.name == names.TYPE_USE)
2371 { if (s.kind == TYP ||
2372 s.kind == VAR ||
2373 (s.kind == MTH && !s.isConstructor() &&
2374 s.type.getReturnType().tag != VOID))
2375 return true;
2376 }
2377 else
2378 return true; // recovery
2379 }
2380 return false;
2381 }
2383 /** Check an annotation value.
2384 */
2385 public void validateAnnotation(JCAnnotation a) {
2386 if (a.type.isErroneous()) return;
2388 // collect an inventory of the members (sorted alphabetically)
2389 Set<MethodSymbol> members = new TreeSet<MethodSymbol>(new Comparator<Symbol>() {
2390 public int compare(Symbol t, Symbol t1) {
2391 return t.name.compareTo(t1.name);
2392 }
2393 });
2394 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
2395 e != null;
2396 e = e.sibling)
2397 if (e.sym.kind == MTH)
2398 members.add((MethodSymbol) e.sym);
2400 // count them off as they're annotated
2401 for (JCTree arg : a.args) {
2402 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
2403 JCAssign assign = (JCAssign) arg;
2404 Symbol m = TreeInfo.symbol(assign.lhs);
2405 if (m == null || m.type.isErroneous()) continue;
2406 if (!members.remove(m))
2407 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
2408 m.name, a.type);
2409 }
2411 // all the remaining ones better have default values
2412 ListBuffer<Name> missingDefaults = ListBuffer.lb();
2413 for (MethodSymbol m : members) {
2414 if (m.defaultValue == null && !m.type.isErroneous()) {
2415 missingDefaults.append(m.name);
2416 }
2417 }
2418 if (missingDefaults.nonEmpty()) {
2419 String key = (missingDefaults.size() > 1)
2420 ? "annotation.missing.default.value.1"
2421 : "annotation.missing.default.value";
2422 log.error(a.pos(), key, a.type, missingDefaults);
2423 }
2425 // special case: java.lang.annotation.Target must not have
2426 // repeated values in its value member
2427 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
2428 a.args.tail == null)
2429 return;
2431 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
2432 JCAssign assign = (JCAssign) a.args.head;
2433 Symbol m = TreeInfo.symbol(assign.lhs);
2434 if (m.name != names.value) return;
2435 JCTree rhs = assign.rhs;
2436 if (rhs.getTag() != JCTree.NEWARRAY) return;
2437 JCNewArray na = (JCNewArray) rhs;
2438 Set<Symbol> targets = new HashSet<Symbol>();
2439 for (JCTree elem : na.elems) {
2440 if (!targets.add(TreeInfo.symbol(elem))) {
2441 log.error(elem.pos(), "repeated.annotation.target");
2442 }
2443 }
2444 }
2446 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
2447 if (allowAnnotations &&
2448 lint.isEnabled(LintCategory.DEP_ANN) &&
2449 (s.flags() & DEPRECATED) != 0 &&
2450 !syms.deprecatedType.isErroneous() &&
2451 s.attribute(syms.deprecatedType.tsym) == null) {
2452 log.warning(LintCategory.DEP_ANN,
2453 pos, "missing.deprecated.annotation");
2454 }
2455 }
2457 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
2458 if ((s.flags() & DEPRECATED) != 0 &&
2459 (other.flags() & DEPRECATED) == 0 &&
2460 s.outermostClass() != other.outermostClass()) {
2461 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
2462 @Override
2463 public void report() {
2464 warnDeprecated(pos, s);
2465 }
2466 });
2467 };
2468 }
2470 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
2471 if ((s.flags() & PROPRIETARY) != 0) {
2472 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
2473 public void report() {
2474 if (enableSunApiLintControl)
2475 warnSunApi(pos, "sun.proprietary", s);
2476 else
2477 log.strictWarning(pos, "sun.proprietary", s);
2478 }
2479 });
2480 }
2481 }
2483 /* *************************************************************************
2484 * Check for recursive annotation elements.
2485 **************************************************************************/
2487 /** Check for cycles in the graph of annotation elements.
2488 */
2489 void checkNonCyclicElements(JCClassDecl tree) {
2490 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
2491 Assert.check((tree.sym.flags_field & LOCKED) == 0);
2492 try {
2493 tree.sym.flags_field |= LOCKED;
2494 for (JCTree def : tree.defs) {
2495 if (def.getTag() != JCTree.METHODDEF) continue;
2496 JCMethodDecl meth = (JCMethodDecl)def;
2497 checkAnnotationResType(meth.pos(), meth.restype.type);
2498 }
2499 } finally {
2500 tree.sym.flags_field &= ~LOCKED;
2501 tree.sym.flags_field |= ACYCLIC_ANN;
2502 }
2503 }
2505 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
2506 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
2507 return;
2508 if ((tsym.flags_field & LOCKED) != 0) {
2509 log.error(pos, "cyclic.annotation.element");
2510 return;
2511 }
2512 try {
2513 tsym.flags_field |= LOCKED;
2514 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
2515 Symbol s = e.sym;
2516 if (s.kind != Kinds.MTH)
2517 continue;
2518 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
2519 }
2520 } finally {
2521 tsym.flags_field &= ~LOCKED;
2522 tsym.flags_field |= ACYCLIC_ANN;
2523 }
2524 }
2526 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
2527 switch (type.tag) {
2528 case TypeTags.CLASS:
2529 if ((type.tsym.flags() & ANNOTATION) != 0)
2530 checkNonCyclicElementsInternal(pos, type.tsym);
2531 break;
2532 case TypeTags.ARRAY:
2533 checkAnnotationResType(pos, types.elemtype(type));
2534 break;
2535 default:
2536 break; // int etc
2537 }
2538 }
2540 /* *************************************************************************
2541 * Check for cycles in the constructor call graph.
2542 **************************************************************************/
2544 /** Check for cycles in the graph of constructors calling other
2545 * constructors.
2546 */
2547 void checkCyclicConstructors(JCClassDecl tree) {
2548 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
2550 // enter each constructor this-call into the map
2551 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2552 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
2553 if (app == null) continue;
2554 JCMethodDecl meth = (JCMethodDecl) l.head;
2555 if (TreeInfo.name(app.meth) == names._this) {
2556 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
2557 } else {
2558 meth.sym.flags_field |= ACYCLIC;
2559 }
2560 }
2562 // Check for cycles in the map
2563 Symbol[] ctors = new Symbol[0];
2564 ctors = callMap.keySet().toArray(ctors);
2565 for (Symbol caller : ctors) {
2566 checkCyclicConstructor(tree, caller, callMap);
2567 }
2568 }
2570 /** Look in the map to see if the given constructor is part of a
2571 * call cycle.
2572 */
2573 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
2574 Map<Symbol,Symbol> callMap) {
2575 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
2576 if ((ctor.flags_field & LOCKED) != 0) {
2577 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
2578 "recursive.ctor.invocation");
2579 } else {
2580 ctor.flags_field |= LOCKED;
2581 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2582 ctor.flags_field &= ~LOCKED;
2583 }
2584 ctor.flags_field |= ACYCLIC;
2585 }
2586 }
2588 /* *************************************************************************
2589 * Miscellaneous
2590 **************************************************************************/
2592 /**
2593 * Return the opcode of the operator but emit an error if it is an
2594 * error.
2595 * @param pos position for error reporting.
2596 * @param operator an operator
2597 * @param tag a tree tag
2598 * @param left type of left hand side
2599 * @param right type of right hand side
2600 */
2601 int checkOperator(DiagnosticPosition pos,
2602 OperatorSymbol operator,
2603 int tag,
2604 Type left,
2605 Type right) {
2606 if (operator.opcode == ByteCodes.error) {
2607 log.error(pos,
2608 "operator.cant.be.applied.1",
2609 treeinfo.operatorName(tag),
2610 left, right);
2611 }
2612 return operator.opcode;
2613 }
2616 /**
2617 * Check for division by integer constant zero
2618 * @param pos Position for error reporting.
2619 * @param operator The operator for the expression
2620 * @param operand The right hand operand for the expression
2621 */
2622 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
2623 if (operand.constValue() != null
2624 && lint.isEnabled(LintCategory.DIVZERO)
2625 && operand.tag <= LONG
2626 && ((Number) (operand.constValue())).longValue() == 0) {
2627 int opc = ((OperatorSymbol)operator).opcode;
2628 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
2629 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
2630 log.warning(LintCategory.DIVZERO, pos, "div.zero");
2631 }
2632 }
2633 }
2635 /**
2636 * Check for empty statements after if
2637 */
2638 void checkEmptyIf(JCIf tree) {
2639 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(LintCategory.EMPTY))
2640 log.warning(LintCategory.EMPTY, tree.thenpart.pos(), "empty.if");
2641 }
2643 /** Check that symbol is unique in given scope.
2644 * @param pos Position for error reporting.
2645 * @param sym The symbol.
2646 * @param s The scope.
2647 */
2648 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2649 if (sym.type.isErroneous())
2650 return true;
2651 if (sym.owner.name == names.any) return false;
2652 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2653 if (sym != e.sym &&
2654 (e.sym.flags() & CLASH) == 0 &&
2655 sym.kind == e.sym.kind &&
2656 sym.name != names.error &&
2657 (sym.kind != MTH || types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
2658 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS)) {
2659 varargsDuplicateError(pos, sym, e.sym);
2660 return true;
2661 } else if (sym.kind == MTH && !types.hasSameArgs(sym.type, e.sym.type, false)) {
2662 duplicateErasureError(pos, sym, e.sym);
2663 sym.flags_field |= CLASH;
2664 return true;
2665 } else {
2666 duplicateError(pos, e.sym);
2667 return false;
2668 }
2669 }
2670 }
2671 return true;
2672 }
2674 /** Report duplicate declaration error.
2675 */
2676 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
2677 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
2678 log.error(pos, "name.clash.same.erasure", sym1, sym2);
2679 }
2680 }
2682 /** Check that single-type import is not already imported or top-level defined,
2683 * but make an exception for two single-type imports which denote the same type.
2684 * @param pos Position for error reporting.
2685 * @param sym The symbol.
2686 * @param s The scope
2687 */
2688 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2689 return checkUniqueImport(pos, sym, s, false);
2690 }
2692 /** Check that static single-type import is not already imported or top-level defined,
2693 * but make an exception for two single-type imports which denote the same type.
2694 * @param pos Position for error reporting.
2695 * @param sym The symbol.
2696 * @param s The scope
2697 * @param staticImport Whether or not this was a static import
2698 */
2699 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2700 return checkUniqueImport(pos, sym, s, true);
2701 }
2703 /** Check that single-type import is not already imported or top-level defined,
2704 * but make an exception for two single-type imports which denote the same type.
2705 * @param pos Position for error reporting.
2706 * @param sym The symbol.
2707 * @param s The scope.
2708 * @param staticImport Whether or not this was a static import
2709 */
2710 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2711 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2712 // is encountered class entered via a class declaration?
2713 boolean isClassDecl = e.scope == s;
2714 if ((isClassDecl || sym != e.sym) &&
2715 sym.kind == e.sym.kind &&
2716 sym.name != names.error) {
2717 if (!e.sym.type.isErroneous()) {
2718 String what = e.sym.toString();
2719 if (!isClassDecl) {
2720 if (staticImport)
2721 log.error(pos, "already.defined.static.single.import", what);
2722 else
2723 log.error(pos, "already.defined.single.import", what);
2724 }
2725 else if (sym != e.sym)
2726 log.error(pos, "already.defined.this.unit", what);
2727 }
2728 return false;
2729 }
2730 }
2731 return true;
2732 }
2734 /** Check that a qualified name is in canonical form (for import decls).
2735 */
2736 public void checkCanonical(JCTree tree) {
2737 if (!isCanonical(tree))
2738 log.error(tree.pos(), "import.requires.canonical",
2739 TreeInfo.symbol(tree));
2740 }
2741 // where
2742 private boolean isCanonical(JCTree tree) {
2743 while (tree.getTag() == JCTree.SELECT) {
2744 JCFieldAccess s = (JCFieldAccess) tree;
2745 if (s.sym.owner != TreeInfo.symbol(s.selected))
2746 return false;
2747 tree = s.selected;
2748 }
2749 return true;
2750 }
2752 private class ConversionWarner extends Warner {
2753 final String uncheckedKey;
2754 final Type found;
2755 final Type expected;
2756 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
2757 super(pos);
2758 this.uncheckedKey = uncheckedKey;
2759 this.found = found;
2760 this.expected = expected;
2761 }
2763 @Override
2764 public void warn(LintCategory lint) {
2765 boolean warned = this.warned;
2766 super.warn(lint);
2767 if (warned) return; // suppress redundant diagnostics
2768 switch (lint) {
2769 case UNCHECKED:
2770 Check.this.warnUnchecked(pos(), "prob.found.req", diags.fragment(uncheckedKey), found, expected);
2771 break;
2772 case VARARGS:
2773 if (method != null &&
2774 method.attribute(syms.trustMeType.tsym) != null &&
2775 isTrustMeAllowedOnMethod(method) &&
2776 !types.isReifiable(method.type.getParameterTypes().last())) {
2777 Check.this.warnUnsafeVararg(pos(), "varargs.unsafe.use.varargs.param", method.params.last());
2778 }
2779 break;
2780 default:
2781 throw new AssertionError("Unexpected lint: " + lint);
2782 }
2783 }
2784 }
2786 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2787 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2788 }
2790 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2791 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2792 }
2793 }
