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src/share/classes/com/sun/tools/javac/comp/Check.java@03cf47d4de15
src/share/classes/com/sun/tools/javac/comp/Check.java
Thu, 03 Feb 2011 09:37:28 +0000
- author
- mcimadamore
- date
- Thu, 03 Feb 2011 09:37:28 +0000
- changeset 854
- 03cf47d4de15
- parent 853
- 875262e89b52
- child 858
- 96d4226bdd60
- permissions
- -rw-r--r--
6969184: poor error recovery after symbol not found
Summary: generic type-well formedness check should ignore erroneous symbols
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 the type inferred using the diamond operator does not contain
668 * non-denotable types such as captured types or intersection types.
669 * @param t the type inferred using the diamond operator
670 */
671 List<Type> checkDiamond(ClassType t) {
672 DiamondTypeChecker dtc = new DiamondTypeChecker();
673 ListBuffer<Type> buf = ListBuffer.lb();
674 for (Type arg : t.getTypeArguments()) {
675 if (!dtc.visit(arg, null)) {
676 buf.append(arg);
677 }
678 }
679 return buf.toList();
680 }
682 static class DiamondTypeChecker extends Types.SimpleVisitor<Boolean, Void> {
683 public Boolean visitType(Type t, Void s) {
684 return true;
685 }
686 @Override
687 public Boolean visitClassType(ClassType t, Void s) {
688 if (t.isCompound()) {
689 return false;
690 }
691 for (Type targ : t.getTypeArguments()) {
692 if (!visit(targ, s)) {
693 return false;
694 }
695 }
696 return true;
697 }
698 @Override
699 public Boolean visitCapturedType(CapturedType t, Void s) {
700 return false;
701 }
702 }
704 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
705 MethodSymbol m = tree.sym;
706 if (!allowSimplifiedVarargs) return;
707 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
708 Type varargElemType = null;
709 if (m.isVarArgs()) {
710 varargElemType = types.elemtype(tree.params.last().type);
711 }
712 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
713 if (varargElemType != null) {
714 log.error(tree,
715 "varargs.invalid.trustme.anno",
716 syms.trustMeType.tsym,
717 diags.fragment("varargs.trustme.on.virtual.varargs", m));
718 } else {
719 log.error(tree,
720 "varargs.invalid.trustme.anno",
721 syms.trustMeType.tsym,
722 diags.fragment("varargs.trustme.on.non.varargs.meth", m));
723 }
724 } else if (hasTrustMeAnno && varargElemType != null &&
725 types.isReifiable(varargElemType)) {
726 warnUnsafeVararg(tree,
727 "varargs.redundant.trustme.anno",
728 syms.trustMeType.tsym,
729 diags.fragment("varargs.trustme.on.reifiable.varargs", varargElemType));
730 }
731 else if (!hasTrustMeAnno && varargElemType != null &&
732 !types.isReifiable(varargElemType)) {
733 warnUnchecked(tree.params.head.pos(), "unchecked.varargs.non.reifiable.type", varargElemType);
734 }
735 }
736 //where
737 private boolean isTrustMeAllowedOnMethod(Symbol s) {
738 return (s.flags() & VARARGS) != 0 &&
739 (s.isConstructor() ||
740 (s.flags() & (STATIC | FINAL)) != 0);
741 }
743 /**
744 * Check that vararg method call is sound
745 * @param pos Position to be used for error reporting.
746 * @param argtypes Actual arguments supplied to vararg method.
747 */
748 void checkVararg(DiagnosticPosition pos, List<Type> argtypes, Symbol msym) {
749 Type argtype = argtypes.last();
750 if (!types.isReifiable(argtype) &&
751 (!allowSimplifiedVarargs ||
752 msym.attribute(syms.trustMeType.tsym) == null ||
753 !isTrustMeAllowedOnMethod(msym))) {
754 warnUnchecked(pos,
755 "unchecked.generic.array.creation",
756 argtype);
757 }
758 }
760 /**
761 * Check that type 't' is a valid instantiation of a generic class
762 * (see JLS 4.5)
763 *
764 * @param t class type to be checked
765 * @return true if 't' is well-formed
766 */
767 public boolean checkValidGenericType(Type t) {
768 return firstIncompatibleTypeArg(t) == null;
769 }
770 //WHERE
771 private Type firstIncompatibleTypeArg(Type type) {
772 List<Type> formals = type.tsym.type.allparams();
773 List<Type> actuals = type.allparams();
774 List<Type> args = type.getTypeArguments();
775 List<Type> forms = type.tsym.type.getTypeArguments();
776 ListBuffer<Type> tvars_buf = new ListBuffer<Type>();
778 // For matching pairs of actual argument types `a' and
779 // formal type parameters with declared bound `b' ...
780 while (args.nonEmpty() && forms.nonEmpty()) {
781 // exact type arguments needs to know their
782 // bounds (for upper and lower bound
783 // calculations). So we create new TypeVars with
784 // bounds substed with actuals.
785 tvars_buf.append(types.substBound(((TypeVar)forms.head),
786 formals,
787 actuals));
788 args = args.tail;
789 forms = forms.tail;
790 }
792 args = type.getTypeArguments();
793 List<Type> tvars_cap = types.substBounds(formals,
794 formals,
795 types.capture(type).allparams());
796 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
797 // Let the actual arguments know their bound
798 args.head.withTypeVar((TypeVar)tvars_cap.head);
799 args = args.tail;
800 tvars_cap = tvars_cap.tail;
801 }
803 args = type.getTypeArguments();
804 List<Type> tvars = tvars_buf.toList();
806 while (args.nonEmpty() && tvars.nonEmpty()) {
807 Type actual = types.subst(args.head,
808 type.tsym.type.getTypeArguments(),
809 tvars_buf.toList());
810 if (!isTypeArgErroneous(actual) &&
811 !tvars.head.getUpperBound().isErroneous() &&
812 !checkExtends(actual, (TypeVar)tvars.head)) {
813 return args.head;
814 }
815 args = args.tail;
816 tvars = tvars.tail;
817 }
819 args = type.getTypeArguments();
820 tvars = tvars_buf.toList();
822 for (Type arg : types.capture(type).getTypeArguments()) {
823 if (arg.tag == TYPEVAR &&
824 arg.getUpperBound().isErroneous() &&
825 !tvars.head.getUpperBound().isErroneous() &&
826 !isTypeArgErroneous(args.head)) {
827 return args.head;
828 }
829 tvars = tvars.tail;
830 args = args.tail;
831 }
833 return null;
834 }
835 //where
836 boolean isTypeArgErroneous(Type t) {
837 return isTypeArgErroneous.visit(t);
838 }
840 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() {
841 public Boolean visitType(Type t, Void s) {
842 return t.isErroneous();
843 }
844 @Override
845 public Boolean visitTypeVar(TypeVar t, Void s) {
846 return visit(t.getUpperBound());
847 }
848 @Override
849 public Boolean visitCapturedType(CapturedType t, Void s) {
850 return visit(t.getUpperBound()) ||
851 visit(t.getLowerBound());
852 }
853 @Override
854 public Boolean visitWildcardType(WildcardType t, Void s) {
855 return visit(t.type);
856 }
857 };
859 /** Check that given modifiers are legal for given symbol and
860 * return modifiers together with any implicit modififiers for that symbol.
861 * Warning: we can't use flags() here since this method
862 * is called during class enter, when flags() would cause a premature
863 * completion.
864 * @param pos Position to be used for error reporting.
865 * @param flags The set of modifiers given in a definition.
866 * @param sym The defined symbol.
867 */
868 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
869 long mask;
870 long implicit = 0;
871 switch (sym.kind) {
872 case VAR:
873 if (sym.owner.kind != TYP)
874 mask = LocalVarFlags;
875 else if ((sym.owner.flags_field & INTERFACE) != 0)
876 mask = implicit = InterfaceVarFlags;
877 else
878 mask = VarFlags;
879 break;
880 case MTH:
881 if (sym.name == names.init) {
882 if ((sym.owner.flags_field & ENUM) != 0) {
883 // enum constructors cannot be declared public or
884 // protected and must be implicitly or explicitly
885 // private
886 implicit = PRIVATE;
887 mask = PRIVATE;
888 } else
889 mask = ConstructorFlags;
890 } else if ((sym.owner.flags_field & INTERFACE) != 0)
891 mask = implicit = InterfaceMethodFlags;
892 else {
893 mask = MethodFlags;
894 }
895 // Imply STRICTFP if owner has STRICTFP set.
896 if (((flags|implicit) & Flags.ABSTRACT) == 0)
897 implicit |= sym.owner.flags_field & STRICTFP;
898 break;
899 case TYP:
900 if (sym.isLocal()) {
901 mask = LocalClassFlags;
902 if (sym.name.isEmpty()) { // Anonymous class
903 // Anonymous classes in static methods are themselves static;
904 // that's why we admit STATIC here.
905 mask |= STATIC;
906 // JLS: Anonymous classes are final.
907 implicit |= FINAL;
908 }
909 if ((sym.owner.flags_field & STATIC) == 0 &&
910 (flags & ENUM) != 0)
911 log.error(pos, "enums.must.be.static");
912 } else if (sym.owner.kind == TYP) {
913 mask = MemberClassFlags;
914 if (sym.owner.owner.kind == PCK ||
915 (sym.owner.flags_field & STATIC) != 0)
916 mask |= STATIC;
917 else if ((flags & ENUM) != 0)
918 log.error(pos, "enums.must.be.static");
919 // Nested interfaces and enums are always STATIC (Spec ???)
920 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
921 } else {
922 mask = ClassFlags;
923 }
924 // Interfaces are always ABSTRACT
925 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
927 if ((flags & ENUM) != 0) {
928 // enums can't be declared abstract or final
929 mask &= ~(ABSTRACT | FINAL);
930 implicit |= implicitEnumFinalFlag(tree);
931 }
932 // Imply STRICTFP if owner has STRICTFP set.
933 implicit |= sym.owner.flags_field & STRICTFP;
934 break;
935 default:
936 throw new AssertionError();
937 }
938 long illegal = flags & StandardFlags & ~mask;
939 if (illegal != 0) {
940 if ((illegal & INTERFACE) != 0) {
941 log.error(pos, "intf.not.allowed.here");
942 mask |= INTERFACE;
943 }
944 else {
945 log.error(pos,
946 "mod.not.allowed.here", asFlagSet(illegal));
947 }
948 }
949 else if ((sym.kind == TYP ||
950 // ISSUE: Disallowing abstract&private is no longer appropriate
951 // in the presence of inner classes. Should it be deleted here?
952 checkDisjoint(pos, flags,
953 ABSTRACT,
954 PRIVATE | STATIC))
955 &&
956 checkDisjoint(pos, flags,
957 ABSTRACT | INTERFACE,
958 FINAL | NATIVE | SYNCHRONIZED)
959 &&
960 checkDisjoint(pos, flags,
961 PUBLIC,
962 PRIVATE | PROTECTED)
963 &&
964 checkDisjoint(pos, flags,
965 PRIVATE,
966 PUBLIC | PROTECTED)
967 &&
968 checkDisjoint(pos, flags,
969 FINAL,
970 VOLATILE)
971 &&
972 (sym.kind == TYP ||
973 checkDisjoint(pos, flags,
974 ABSTRACT | NATIVE,
975 STRICTFP))) {
976 // skip
977 }
978 return flags & (mask | ~StandardFlags) | implicit;
979 }
982 /** Determine if this enum should be implicitly final.
983 *
984 * If the enum has no specialized enum contants, it is final.
985 *
986 * If the enum does have specialized enum contants, it is
987 * <i>not</i> final.
988 */
989 private long implicitEnumFinalFlag(JCTree tree) {
990 if (tree.getTag() != JCTree.CLASSDEF) return 0;
991 class SpecialTreeVisitor extends JCTree.Visitor {
992 boolean specialized;
993 SpecialTreeVisitor() {
994 this.specialized = false;
995 };
997 @Override
998 public void visitTree(JCTree tree) { /* no-op */ }
1000 @Override
1001 public void visitVarDef(JCVariableDecl tree) {
1002 if ((tree.mods.flags & ENUM) != 0) {
1003 if (tree.init instanceof JCNewClass &&
1004 ((JCNewClass) tree.init).def != null) {
1005 specialized = true;
1006 }
1007 }
1008 }
1009 }
1011 SpecialTreeVisitor sts = new SpecialTreeVisitor();
1012 JCClassDecl cdef = (JCClassDecl) tree;
1013 for (JCTree defs: cdef.defs) {
1014 defs.accept(sts);
1015 if (sts.specialized) return 0;
1016 }
1017 return FINAL;
1018 }
1020 /* *************************************************************************
1021 * Type Validation
1022 **************************************************************************/
1024 /** Validate a type expression. That is,
1025 * check that all type arguments of a parametric type are within
1026 * their bounds. This must be done in a second phase after type attributon
1027 * since a class might have a subclass as type parameter bound. E.g:
1028 *
1029 * class B<A extends C> { ... }
1030 * class C extends B<C> { ... }
1031 *
1032 * and we can't make sure that the bound is already attributed because
1033 * of possible cycles.
1034 *
1035 * Visitor method: Validate a type expression, if it is not null, catching
1036 * and reporting any completion failures.
1037 */
1038 void validate(JCTree tree, Env<AttrContext> env) {
1039 validate(tree, env, true);
1040 }
1041 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1042 new Validator(env).validateTree(tree, checkRaw, true);
1043 }
1045 /** Visitor method: Validate a list of type expressions.
1046 */
1047 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1048 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1049 validate(l.head, env);
1050 }
1052 /** A visitor class for type validation.
1053 */
1054 class Validator extends JCTree.Visitor {
1056 boolean isOuter;
1057 Env<AttrContext> env;
1059 Validator(Env<AttrContext> env) {
1060 this.env = env;
1061 }
1063 @Override
1064 public void visitTypeArray(JCArrayTypeTree tree) {
1065 tree.elemtype.accept(this);
1066 }
1068 @Override
1069 public void visitTypeApply(JCTypeApply tree) {
1070 if (tree.type.tag == CLASS) {
1071 List<JCExpression> args = tree.arguments;
1072 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1074 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1075 if (incompatibleArg != null) {
1076 for (JCTree arg : tree.arguments) {
1077 if (arg.type == incompatibleArg) {
1078 log.error(arg, "not.within.bounds", incompatibleArg, forms.head);
1079 }
1080 forms = forms.tail;
1081 }
1082 }
1084 forms = tree.type.tsym.type.getTypeArguments();
1086 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1088 // For matching pairs of actual argument types `a' and
1089 // formal type parameters with declared bound `b' ...
1090 while (args.nonEmpty() && forms.nonEmpty()) {
1091 validateTree(args.head,
1092 !(isOuter && is_java_lang_Class),
1093 false);
1094 args = args.tail;
1095 forms = forms.tail;
1096 }
1098 // Check that this type is either fully parameterized, or
1099 // not parameterized at all.
1100 if (tree.type.getEnclosingType().isRaw())
1101 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
1102 if (tree.clazz.getTag() == JCTree.SELECT)
1103 visitSelectInternal((JCFieldAccess)tree.clazz);
1104 }
1105 }
1107 @Override
1108 public void visitTypeParameter(JCTypeParameter tree) {
1109 validateTrees(tree.bounds, true, isOuter);
1110 checkClassBounds(tree.pos(), tree.type);
1111 }
1113 @Override
1114 public void visitWildcard(JCWildcard tree) {
1115 if (tree.inner != null)
1116 validateTree(tree.inner, true, isOuter);
1117 }
1119 @Override
1120 public void visitSelect(JCFieldAccess tree) {
1121 if (tree.type.tag == CLASS) {
1122 visitSelectInternal(tree);
1124 // Check that this type is either fully parameterized, or
1125 // not parameterized at all.
1126 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1127 log.error(tree.pos(), "improperly.formed.type.param.missing");
1128 }
1129 }
1131 public void visitSelectInternal(JCFieldAccess tree) {
1132 if (tree.type.tsym.isStatic() &&
1133 tree.selected.type.isParameterized()) {
1134 // The enclosing type is not a class, so we are
1135 // looking at a static member type. However, the
1136 // qualifying expression is parameterized.
1137 log.error(tree.pos(), "cant.select.static.class.from.param.type");
1138 } else {
1139 // otherwise validate the rest of the expression
1140 tree.selected.accept(this);
1141 }
1142 }
1144 /** Default visitor method: do nothing.
1145 */
1146 @Override
1147 public void visitTree(JCTree tree) {
1148 }
1150 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1151 try {
1152 if (tree != null) {
1153 this.isOuter = isOuter;
1154 tree.accept(this);
1155 if (checkRaw)
1156 checkRaw(tree, env);
1157 }
1158 } catch (CompletionFailure ex) {
1159 completionError(tree.pos(), ex);
1160 }
1161 }
1163 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1164 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1165 validateTree(l.head, checkRaw, isOuter);
1166 }
1168 void checkRaw(JCTree tree, Env<AttrContext> env) {
1169 if (lint.isEnabled(LintCategory.RAW) &&
1170 tree.type.tag == CLASS &&
1171 !TreeInfo.isDiamond(tree) &&
1172 !env.enclClass.name.isEmpty() && //anonymous or intersection
1173 tree.type.isRaw()) {
1174 log.warning(LintCategory.RAW,
1175 tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
1176 }
1177 }
1178 }
1180 /* *************************************************************************
1181 * Exception checking
1182 **************************************************************************/
1184 /* The following methods treat classes as sets that contain
1185 * the class itself and all their subclasses
1186 */
1188 /** Is given type a subtype of some of the types in given list?
1189 */
1190 boolean subset(Type t, List<Type> ts) {
1191 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1192 if (types.isSubtype(t, l.head)) return true;
1193 return false;
1194 }
1196 /** Is given type a subtype or supertype of
1197 * some of the types in given list?
1198 */
1199 boolean intersects(Type t, List<Type> ts) {
1200 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1201 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1202 return false;
1203 }
1205 /** Add type set to given type list, unless it is a subclass of some class
1206 * in the list.
1207 */
1208 List<Type> incl(Type t, List<Type> ts) {
1209 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1210 }
1212 /** Remove type set from type set list.
1213 */
1214 List<Type> excl(Type t, List<Type> ts) {
1215 if (ts.isEmpty()) {
1216 return ts;
1217 } else {
1218 List<Type> ts1 = excl(t, ts.tail);
1219 if (types.isSubtype(ts.head, t)) return ts1;
1220 else if (ts1 == ts.tail) return ts;
1221 else return ts1.prepend(ts.head);
1222 }
1223 }
1225 /** Form the union of two type set lists.
1226 */
1227 List<Type> union(List<Type> ts1, List<Type> ts2) {
1228 List<Type> ts = ts1;
1229 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1230 ts = incl(l.head, ts);
1231 return ts;
1232 }
1234 /** Form the difference of two type lists.
1235 */
1236 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1237 List<Type> ts = ts1;
1238 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1239 ts = excl(l.head, ts);
1240 return ts;
1241 }
1243 /** Form the intersection of two type lists.
1244 */
1245 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1246 List<Type> ts = List.nil();
1247 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1248 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1249 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1250 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1251 return ts;
1252 }
1254 /** Is exc an exception symbol that need not be declared?
1255 */
1256 boolean isUnchecked(ClassSymbol exc) {
1257 return
1258 exc.kind == ERR ||
1259 exc.isSubClass(syms.errorType.tsym, types) ||
1260 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1261 }
1263 /** Is exc an exception type that need not be declared?
1264 */
1265 boolean isUnchecked(Type exc) {
1266 return
1267 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
1268 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
1269 exc.tag == BOT;
1270 }
1272 /** Same, but handling completion failures.
1273 */
1274 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1275 try {
1276 return isUnchecked(exc);
1277 } catch (CompletionFailure ex) {
1278 completionError(pos, ex);
1279 return true;
1280 }
1281 }
1283 /** Is exc handled by given exception list?
1284 */
1285 boolean isHandled(Type exc, List<Type> handled) {
1286 return isUnchecked(exc) || subset(exc, handled);
1287 }
1289 /** Return all exceptions in thrown list that are not in handled list.
1290 * @param thrown The list of thrown exceptions.
1291 * @param handled The list of handled exceptions.
1292 */
1293 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1294 List<Type> unhandled = List.nil();
1295 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1296 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1297 return unhandled;
1298 }
1300 /* *************************************************************************
1301 * Overriding/Implementation checking
1302 **************************************************************************/
1304 /** The level of access protection given by a flag set,
1305 * where PRIVATE is highest and PUBLIC is lowest.
1306 */
1307 static int protection(long flags) {
1308 switch ((short)(flags & AccessFlags)) {
1309 case PRIVATE: return 3;
1310 case PROTECTED: return 1;
1311 default:
1312 case PUBLIC: return 0;
1313 case 0: return 2;
1314 }
1315 }
1317 /** A customized "cannot override" error message.
1318 * @param m The overriding method.
1319 * @param other The overridden method.
1320 * @return An internationalized string.
1321 */
1322 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1323 String key;
1324 if ((other.owner.flags() & INTERFACE) == 0)
1325 key = "cant.override";
1326 else if ((m.owner.flags() & INTERFACE) == 0)
1327 key = "cant.implement";
1328 else
1329 key = "clashes.with";
1330 return diags.fragment(key, m, m.location(), other, other.location());
1331 }
1333 /** A customized "override" warning message.
1334 * @param m The overriding method.
1335 * @param other The overridden method.
1336 * @return An internationalized string.
1337 */
1338 Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1339 String key;
1340 if ((other.owner.flags() & INTERFACE) == 0)
1341 key = "unchecked.override";
1342 else if ((m.owner.flags() & INTERFACE) == 0)
1343 key = "unchecked.implement";
1344 else
1345 key = "unchecked.clash.with";
1346 return diags.fragment(key, m, m.location(), other, other.location());
1347 }
1349 /** A customized "override" warning message.
1350 * @param m The overriding method.
1351 * @param other The overridden method.
1352 * @return An internationalized string.
1353 */
1354 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1355 String key;
1356 if ((other.owner.flags() & INTERFACE) == 0)
1357 key = "varargs.override";
1358 else if ((m.owner.flags() & INTERFACE) == 0)
1359 key = "varargs.implement";
1360 else
1361 key = "varargs.clash.with";
1362 return diags.fragment(key, m, m.location(), other, other.location());
1363 }
1365 /** Check that this method conforms with overridden method 'other'.
1366 * where `origin' is the class where checking started.
1367 * Complications:
1368 * (1) Do not check overriding of synthetic methods
1369 * (reason: they might be final).
1370 * todo: check whether this is still necessary.
1371 * (2) Admit the case where an interface proxy throws fewer exceptions
1372 * than the method it implements. Augment the proxy methods with the
1373 * undeclared exceptions in this case.
1374 * (3) When generics are enabled, admit the case where an interface proxy
1375 * has a result type
1376 * extended by the result type of the method it implements.
1377 * Change the proxies result type to the smaller type in this case.
1378 *
1379 * @param tree The tree from which positions
1380 * are extracted for errors.
1381 * @param m The overriding method.
1382 * @param other The overridden method.
1383 * @param origin The class of which the overriding method
1384 * is a member.
1385 */
1386 void checkOverride(JCTree tree,
1387 MethodSymbol m,
1388 MethodSymbol other,
1389 ClassSymbol origin) {
1390 // Don't check overriding of synthetic methods or by bridge methods.
1391 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1392 return;
1393 }
1395 // Error if static method overrides instance method (JLS 8.4.6.2).
1396 if ((m.flags() & STATIC) != 0 &&
1397 (other.flags() & STATIC) == 0) {
1398 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1399 cannotOverride(m, other));
1400 return;
1401 }
1403 // Error if instance method overrides static or final
1404 // method (JLS 8.4.6.1).
1405 if ((other.flags() & FINAL) != 0 ||
1406 (m.flags() & STATIC) == 0 &&
1407 (other.flags() & STATIC) != 0) {
1408 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1409 cannotOverride(m, other),
1410 asFlagSet(other.flags() & (FINAL | STATIC)));
1411 return;
1412 }
1414 if ((m.owner.flags() & ANNOTATION) != 0) {
1415 // handled in validateAnnotationMethod
1416 return;
1417 }
1419 // Error if overriding method has weaker access (JLS 8.4.6.3).
1420 if ((origin.flags() & INTERFACE) == 0 &&
1421 protection(m.flags()) > protection(other.flags())) {
1422 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1423 cannotOverride(m, other),
1424 other.flags() == 0 ?
1425 Flag.PACKAGE :
1426 asFlagSet(other.flags() & AccessFlags));
1427 return;
1428 }
1430 Type mt = types.memberType(origin.type, m);
1431 Type ot = types.memberType(origin.type, other);
1432 // Error if overriding result type is different
1433 // (or, in the case of generics mode, not a subtype) of
1434 // overridden result type. We have to rename any type parameters
1435 // before comparing types.
1436 List<Type> mtvars = mt.getTypeArguments();
1437 List<Type> otvars = ot.getTypeArguments();
1438 Type mtres = mt.getReturnType();
1439 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1441 overrideWarner.clear();
1442 boolean resultTypesOK =
1443 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1444 if (!resultTypesOK) {
1445 if (!allowCovariantReturns &&
1446 m.owner != origin &&
1447 m.owner.isSubClass(other.owner, types)) {
1448 // allow limited interoperability with covariant returns
1449 } else {
1450 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1451 "override.incompatible.ret",
1452 cannotOverride(m, other),
1453 mtres, otres);
1454 return;
1455 }
1456 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1457 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1458 "override.unchecked.ret",
1459 uncheckedOverrides(m, other),
1460 mtres, otres);
1461 }
1463 // Error if overriding method throws an exception not reported
1464 // by overridden method.
1465 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1466 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1467 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1468 if (unhandledErased.nonEmpty()) {
1469 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1470 "override.meth.doesnt.throw",
1471 cannotOverride(m, other),
1472 unhandledUnerased.head);
1473 return;
1474 }
1475 else if (unhandledUnerased.nonEmpty()) {
1476 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1477 "override.unchecked.thrown",
1478 cannotOverride(m, other),
1479 unhandledUnerased.head);
1480 return;
1481 }
1483 // Optional warning if varargs don't agree
1484 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1485 && lint.isEnabled(LintCategory.OVERRIDES)) {
1486 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1487 ((m.flags() & Flags.VARARGS) != 0)
1488 ? "override.varargs.missing"
1489 : "override.varargs.extra",
1490 varargsOverrides(m, other));
1491 }
1493 // Warn if instance method overrides bridge method (compiler spec ??)
1494 if ((other.flags() & BRIDGE) != 0) {
1495 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1496 uncheckedOverrides(m, other));
1497 }
1499 // Warn if a deprecated method overridden by a non-deprecated one.
1500 if (!isDeprecatedOverrideIgnorable(other, origin)) {
1501 checkDeprecated(TreeInfo.diagnosticPositionFor(m, tree), m, other);
1502 }
1503 }
1504 // where
1505 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1506 // If the method, m, is defined in an interface, then ignore the issue if the method
1507 // is only inherited via a supertype and also implemented in the supertype,
1508 // because in that case, we will rediscover the issue when examining the method
1509 // in the supertype.
1510 // If the method, m, is not defined in an interface, then the only time we need to
1511 // address the issue is when the method is the supertype implemementation: any other
1512 // case, we will have dealt with when examining the supertype classes
1513 ClassSymbol mc = m.enclClass();
1514 Type st = types.supertype(origin.type);
1515 if (st.tag != CLASS)
1516 return true;
1517 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1519 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1520 List<Type> intfs = types.interfaces(origin.type);
1521 return (intfs.contains(mc.type) ? false : (stimpl != null));
1522 }
1523 else
1524 return (stimpl != m);
1525 }
1528 // used to check if there were any unchecked conversions
1529 Warner overrideWarner = new Warner();
1531 /** Check that a class does not inherit two concrete methods
1532 * with the same signature.
1533 * @param pos Position to be used for error reporting.
1534 * @param site The class type to be checked.
1535 */
1536 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1537 Type sup = types.supertype(site);
1538 if (sup.tag != CLASS) return;
1540 for (Type t1 = sup;
1541 t1.tsym.type.isParameterized();
1542 t1 = types.supertype(t1)) {
1543 for (Scope.Entry e1 = t1.tsym.members().elems;
1544 e1 != null;
1545 e1 = e1.sibling) {
1546 Symbol s1 = e1.sym;
1547 if (s1.kind != MTH ||
1548 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1549 !s1.isInheritedIn(site.tsym, types) ||
1550 ((MethodSymbol)s1).implementation(site.tsym,
1551 types,
1552 true) != s1)
1553 continue;
1554 Type st1 = types.memberType(t1, s1);
1555 int s1ArgsLength = st1.getParameterTypes().length();
1556 if (st1 == s1.type) continue;
1558 for (Type t2 = sup;
1559 t2.tag == CLASS;
1560 t2 = types.supertype(t2)) {
1561 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1562 e2.scope != null;
1563 e2 = e2.next()) {
1564 Symbol s2 = e2.sym;
1565 if (s2 == s1 ||
1566 s2.kind != MTH ||
1567 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1568 s2.type.getParameterTypes().length() != s1ArgsLength ||
1569 !s2.isInheritedIn(site.tsym, types) ||
1570 ((MethodSymbol)s2).implementation(site.tsym,
1571 types,
1572 true) != s2)
1573 continue;
1574 Type st2 = types.memberType(t2, s2);
1575 if (types.overrideEquivalent(st1, st2))
1576 log.error(pos, "concrete.inheritance.conflict",
1577 s1, t1, s2, t2, sup);
1578 }
1579 }
1580 }
1581 }
1582 }
1584 /** Check that classes (or interfaces) do not each define an abstract
1585 * method with same name and arguments but incompatible return types.
1586 * @param pos Position to be used for error reporting.
1587 * @param t1 The first argument type.
1588 * @param t2 The second argument type.
1589 */
1590 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1591 Type t1,
1592 Type t2) {
1593 return checkCompatibleAbstracts(pos, t1, t2,
1594 types.makeCompoundType(t1, t2));
1595 }
1597 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1598 Type t1,
1599 Type t2,
1600 Type site) {
1601 return firstIncompatibility(pos, t1, t2, site) == null;
1602 }
1604 /** Return the first method which is defined with same args
1605 * but different return types in two given interfaces, or null if none
1606 * exists.
1607 * @param t1 The first type.
1608 * @param t2 The second type.
1609 * @param site The most derived type.
1610 * @returns symbol from t2 that conflicts with one in t1.
1611 */
1612 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1613 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1614 closure(t1, interfaces1);
1615 Map<TypeSymbol,Type> interfaces2;
1616 if (t1 == t2)
1617 interfaces2 = interfaces1;
1618 else
1619 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1621 for (Type t3 : interfaces1.values()) {
1622 for (Type t4 : interfaces2.values()) {
1623 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
1624 if (s != null) return s;
1625 }
1626 }
1627 return null;
1628 }
1630 /** Compute all the supertypes of t, indexed by type symbol. */
1631 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1632 if (t.tag != CLASS) return;
1633 if (typeMap.put(t.tsym, t) == null) {
1634 closure(types.supertype(t), typeMap);
1635 for (Type i : types.interfaces(t))
1636 closure(i, typeMap);
1637 }
1638 }
1640 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1641 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1642 if (t.tag != CLASS) return;
1643 if (typesSkip.get(t.tsym) != null) return;
1644 if (typeMap.put(t.tsym, t) == null) {
1645 closure(types.supertype(t), typesSkip, typeMap);
1646 for (Type i : types.interfaces(t))
1647 closure(i, typesSkip, typeMap);
1648 }
1649 }
1651 /** Return the first method in t2 that conflicts with a method from t1. */
1652 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1653 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1654 Symbol s1 = e1.sym;
1655 Type st1 = null;
1656 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1657 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1658 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1659 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1660 Symbol s2 = e2.sym;
1661 if (s1 == s2) continue;
1662 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1663 if (st1 == null) st1 = types.memberType(t1, s1);
1664 Type st2 = types.memberType(t2, s2);
1665 if (types.overrideEquivalent(st1, st2)) {
1666 List<Type> tvars1 = st1.getTypeArguments();
1667 List<Type> tvars2 = st2.getTypeArguments();
1668 Type rt1 = st1.getReturnType();
1669 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1670 boolean compat =
1671 types.isSameType(rt1, rt2) ||
1672 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1673 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1674 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1675 checkCommonOverriderIn(s1,s2,site);
1676 if (!compat) {
1677 log.error(pos, "types.incompatible.diff.ret",
1678 t1, t2, s2.name +
1679 "(" + types.memberType(t2, s2).getParameterTypes() + ")");
1680 return s2;
1681 }
1682 } else if (!checkNameClash((ClassSymbol)site.tsym, s1, s2)) {
1683 log.error(pos,
1684 "name.clash.same.erasure.no.override",
1685 s1, s1.location(),
1686 s2, s2.location());
1687 return s2;
1688 }
1689 }
1690 }
1691 return null;
1692 }
1693 //WHERE
1694 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1695 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1696 Type st1 = types.memberType(site, s1);
1697 Type st2 = types.memberType(site, s2);
1698 closure(site, supertypes);
1699 for (Type t : supertypes.values()) {
1700 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1701 Symbol s3 = e.sym;
1702 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1703 Type st3 = types.memberType(site,s3);
1704 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1705 if (s3.owner == site.tsym) {
1706 return true;
1707 }
1708 List<Type> tvars1 = st1.getTypeArguments();
1709 List<Type> tvars2 = st2.getTypeArguments();
1710 List<Type> tvars3 = st3.getTypeArguments();
1711 Type rt1 = st1.getReturnType();
1712 Type rt2 = st2.getReturnType();
1713 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1714 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1715 boolean compat =
1716 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1717 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1718 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1719 if (compat)
1720 return true;
1721 }
1722 }
1723 }
1724 return false;
1725 }
1727 /** Check that a given method conforms with any method it overrides.
1728 * @param tree The tree from which positions are extracted
1729 * for errors.
1730 * @param m The overriding method.
1731 */
1732 void checkOverride(JCTree tree, MethodSymbol m) {
1733 ClassSymbol origin = (ClassSymbol)m.owner;
1734 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1735 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1736 log.error(tree.pos(), "enum.no.finalize");
1737 return;
1738 }
1739 for (Type t = origin.type; t.tag == CLASS;
1740 t = types.supertype(t)) {
1741 if (t != origin.type) {
1742 checkOverride(tree, t, origin, m);
1743 }
1744 for (Type t2 : types.interfaces(t)) {
1745 checkOverride(tree, t2, origin, m);
1746 }
1747 }
1748 }
1750 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
1751 TypeSymbol c = site.tsym;
1752 Scope.Entry e = c.members().lookup(m.name);
1753 while (e.scope != null) {
1754 if (m.overrides(e.sym, origin, types, false)) {
1755 if ((e.sym.flags() & ABSTRACT) == 0) {
1756 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1757 }
1758 }
1759 e = e.next();
1760 }
1761 }
1763 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
1764 if (s1.kind == MTH &&
1765 s1.isInheritedIn(origin, types) &&
1766 (s1.flags() & SYNTHETIC) == 0 &&
1767 !s2.isConstructor()) {
1768 Type er1 = s2.erasure(types);
1769 Type er2 = s1.erasure(types);
1770 if (types.isSameTypes(er1.getParameterTypes(),
1771 er2.getParameterTypes())) {
1772 return false;
1773 }
1774 }
1775 return true;
1776 }
1779 /** Check that all abstract members of given class have definitions.
1780 * @param pos Position to be used for error reporting.
1781 * @param c The class.
1782 */
1783 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1784 try {
1785 MethodSymbol undef = firstUndef(c, c);
1786 if (undef != null) {
1787 if ((c.flags() & ENUM) != 0 &&
1788 types.supertype(c.type).tsym == syms.enumSym &&
1789 (c.flags() & FINAL) == 0) {
1790 // add the ABSTRACT flag to an enum
1791 c.flags_field |= ABSTRACT;
1792 } else {
1793 MethodSymbol undef1 =
1794 new MethodSymbol(undef.flags(), undef.name,
1795 types.memberType(c.type, undef), undef.owner);
1796 log.error(pos, "does.not.override.abstract",
1797 c, undef1, undef1.location());
1798 }
1799 }
1800 } catch (CompletionFailure ex) {
1801 completionError(pos, ex);
1802 }
1803 }
1804 //where
1805 /** Return first abstract member of class `c' that is not defined
1806 * in `impl', null if there is none.
1807 */
1808 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1809 MethodSymbol undef = null;
1810 // Do not bother to search in classes that are not abstract,
1811 // since they cannot have abstract members.
1812 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1813 Scope s = c.members();
1814 for (Scope.Entry e = s.elems;
1815 undef == null && e != null;
1816 e = e.sibling) {
1817 if (e.sym.kind == MTH &&
1818 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1819 MethodSymbol absmeth = (MethodSymbol)e.sym;
1820 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1821 if (implmeth == null || implmeth == absmeth)
1822 undef = absmeth;
1823 }
1824 }
1825 if (undef == null) {
1826 Type st = types.supertype(c.type);
1827 if (st.tag == CLASS)
1828 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1829 }
1830 for (List<Type> l = types.interfaces(c.type);
1831 undef == null && l.nonEmpty();
1832 l = l.tail) {
1833 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1834 }
1835 }
1836 return undef;
1837 }
1839 void checkNonCyclicDecl(JCClassDecl tree) {
1840 CycleChecker cc = new CycleChecker();
1841 cc.scan(tree);
1842 if (!cc.errorFound && !cc.partialCheck) {
1843 tree.sym.flags_field |= ACYCLIC;
1844 }
1845 }
1847 class CycleChecker extends TreeScanner {
1849 List<Symbol> seenClasses = List.nil();
1850 boolean errorFound = false;
1851 boolean partialCheck = false;
1853 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
1854 if (sym != null && sym.kind == TYP) {
1855 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
1856 if (classEnv != null) {
1857 DiagnosticSource prevSource = log.currentSource();
1858 try {
1859 log.useSource(classEnv.toplevel.sourcefile);
1860 scan(classEnv.tree);
1861 }
1862 finally {
1863 log.useSource(prevSource.getFile());
1864 }
1865 } else if (sym.kind == TYP) {
1866 checkClass(pos, sym, List.<JCTree>nil());
1867 }
1868 } else {
1869 //not completed yet
1870 partialCheck = true;
1871 }
1872 }
1874 @Override
1875 public void visitSelect(JCFieldAccess tree) {
1876 super.visitSelect(tree);
1877 checkSymbol(tree.pos(), tree.sym);
1878 }
1880 @Override
1881 public void visitIdent(JCIdent tree) {
1882 checkSymbol(tree.pos(), tree.sym);
1883 }
1885 @Override
1886 public void visitTypeApply(JCTypeApply tree) {
1887 scan(tree.clazz);
1888 }
1890 @Override
1891 public void visitTypeArray(JCArrayTypeTree tree) {
1892 scan(tree.elemtype);
1893 }
1895 @Override
1896 public void visitClassDef(JCClassDecl tree) {
1897 List<JCTree> supertypes = List.nil();
1898 if (tree.getExtendsClause() != null) {
1899 supertypes = supertypes.prepend(tree.getExtendsClause());
1900 }
1901 if (tree.getImplementsClause() != null) {
1902 for (JCTree intf : tree.getImplementsClause()) {
1903 supertypes = supertypes.prepend(intf);
1904 }
1905 }
1906 checkClass(tree.pos(), tree.sym, supertypes);
1907 }
1909 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
1910 if ((c.flags_field & ACYCLIC) != 0)
1911 return;
1912 if (seenClasses.contains(c)) {
1913 errorFound = true;
1914 noteCyclic(pos, (ClassSymbol)c);
1915 } else if (!c.type.isErroneous()) {
1916 try {
1917 seenClasses = seenClasses.prepend(c);
1918 if (c.type.tag == CLASS) {
1919 if (supertypes.nonEmpty()) {
1920 scan(supertypes);
1921 }
1922 else {
1923 ClassType ct = (ClassType)c.type;
1924 if (ct.supertype_field == null ||
1925 ct.interfaces_field == null) {
1926 //not completed yet
1927 partialCheck = true;
1928 return;
1929 }
1930 checkSymbol(pos, ct.supertype_field.tsym);
1931 for (Type intf : ct.interfaces_field) {
1932 checkSymbol(pos, intf.tsym);
1933 }
1934 }
1935 if (c.owner.kind == TYP) {
1936 checkSymbol(pos, c.owner);
1937 }
1938 }
1939 } finally {
1940 seenClasses = seenClasses.tail;
1941 }
1942 }
1943 }
1944 }
1946 /** Check for cyclic references. Issue an error if the
1947 * symbol of the type referred to has a LOCKED flag set.
1948 *
1949 * @param pos Position to be used for error reporting.
1950 * @param t The type referred to.
1951 */
1952 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1953 checkNonCyclicInternal(pos, t);
1954 }
1957 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1958 checkNonCyclic1(pos, t, List.<TypeVar>nil());
1959 }
1961 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
1962 final TypeVar tv;
1963 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
1964 return;
1965 if (seen.contains(t)) {
1966 tv = (TypeVar)t;
1967 tv.bound = types.createErrorType(t);
1968 log.error(pos, "cyclic.inheritance", t);
1969 } else if (t.tag == TYPEVAR) {
1970 tv = (TypeVar)t;
1971 seen = seen.prepend(tv);
1972 for (Type b : types.getBounds(tv))
1973 checkNonCyclic1(pos, b, seen);
1974 }
1975 }
1977 /** Check for cyclic references. Issue an error if the
1978 * symbol of the type referred to has a LOCKED flag set.
1979 *
1980 * @param pos Position to be used for error reporting.
1981 * @param t The type referred to.
1982 * @returns True if the check completed on all attributed classes
1983 */
1984 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1985 boolean complete = true; // was the check complete?
1986 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1987 Symbol c = t.tsym;
1988 if ((c.flags_field & ACYCLIC) != 0) return true;
1990 if ((c.flags_field & LOCKED) != 0) {
1991 noteCyclic(pos, (ClassSymbol)c);
1992 } else if (!c.type.isErroneous()) {
1993 try {
1994 c.flags_field |= LOCKED;
1995 if (c.type.tag == CLASS) {
1996 ClassType clazz = (ClassType)c.type;
1997 if (clazz.interfaces_field != null)
1998 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1999 complete &= checkNonCyclicInternal(pos, l.head);
2000 if (clazz.supertype_field != null) {
2001 Type st = clazz.supertype_field;
2002 if (st != null && st.tag == CLASS)
2003 complete &= checkNonCyclicInternal(pos, st);
2004 }
2005 if (c.owner.kind == TYP)
2006 complete &= checkNonCyclicInternal(pos, c.owner.type);
2007 }
2008 } finally {
2009 c.flags_field &= ~LOCKED;
2010 }
2011 }
2012 if (complete)
2013 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
2014 if (complete) c.flags_field |= ACYCLIC;
2015 return complete;
2016 }
2018 /** Note that we found an inheritance cycle. */
2019 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
2020 log.error(pos, "cyclic.inheritance", c);
2021 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
2022 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
2023 Type st = types.supertype(c.type);
2024 if (st.tag == CLASS)
2025 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2026 c.type = types.createErrorType(c, c.type);
2027 c.flags_field |= ACYCLIC;
2028 }
2030 /** Check that all methods which implement some
2031 * method conform to the method they implement.
2032 * @param tree The class definition whose members are checked.
2033 */
2034 void checkImplementations(JCClassDecl tree) {
2035 checkImplementations(tree, tree.sym);
2036 }
2037 //where
2038 /** Check that all methods which implement some
2039 * method in `ic' conform to the method they implement.
2040 */
2041 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
2042 ClassSymbol origin = tree.sym;
2043 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2044 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2045 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
2046 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
2047 if (e.sym.kind == MTH &&
2048 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2049 MethodSymbol absmeth = (MethodSymbol)e.sym;
2050 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2051 if (implmeth != null && implmeth != absmeth &&
2052 (implmeth.owner.flags() & INTERFACE) ==
2053 (origin.flags() & INTERFACE)) {
2054 // don't check if implmeth is in a class, yet
2055 // origin is an interface. This case arises only
2056 // if implmeth is declared in Object. The reason is
2057 // that interfaces really don't inherit from
2058 // Object it's just that the compiler represents
2059 // things that way.
2060 checkOverride(tree, implmeth, absmeth, origin);
2061 }
2062 }
2063 }
2064 }
2065 }
2066 }
2068 /** Check that all abstract methods implemented by a class are
2069 * mutually compatible.
2070 * @param pos Position to be used for error reporting.
2071 * @param c The class whose interfaces are checked.
2072 */
2073 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2074 List<Type> supertypes = types.interfaces(c);
2075 Type supertype = types.supertype(c);
2076 if (supertype.tag == CLASS &&
2077 (supertype.tsym.flags() & ABSTRACT) != 0)
2078 supertypes = supertypes.prepend(supertype);
2079 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2080 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
2081 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2082 return;
2083 for (List<Type> m = supertypes; m != l; m = m.tail)
2084 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2085 return;
2086 }
2087 checkCompatibleConcretes(pos, c);
2088 }
2090 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
2091 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
2092 for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
2093 // VM allows methods and variables with differing types
2094 if (sym.kind == e.sym.kind &&
2095 types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
2096 sym != e.sym &&
2097 (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
2098 (sym.flags() & IPROXY) == 0 && (e.sym.flags() & IPROXY) == 0 &&
2099 (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
2100 syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
2101 return;
2102 }
2103 }
2104 }
2105 }
2107 /** Check that all non-override equivalent methods accessible from 'site'
2108 * are mutually compatible (JLS 8.4.8/9.4.1).
2109 *
2110 * @param pos Position to be used for error reporting.
2111 * @param site The class whose methods are checked.
2112 * @param sym The method symbol to be checked.
2113 */
2114 void checkClashes(DiagnosticPosition pos, Type site, Symbol sym) {
2115 List<Type> supertypes = types.closure(site);
2116 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2117 for (List<Type> m = supertypes; m.nonEmpty(); m = m.tail) {
2118 checkClashes(pos, l.head, m.head, site, sym);
2119 }
2120 }
2121 }
2123 /** Reports an error whenever 'sym' seen as a member of type 't1' clashes with
2124 * some unrelated method defined in 't2'.
2125 */
2126 private void checkClashes(DiagnosticPosition pos, Type t1, Type t2, Type site, Symbol s1) {
2127 ClashFilter cf = new ClashFilter(site);
2128 s1 = ((MethodSymbol)s1).implementedIn(t1.tsym, types);
2129 if (s1 == null) return;
2130 Type st1 = types.memberType(site, s1);
2131 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name, cf); e2.scope != null; e2 = e2.next(cf)) {
2132 Symbol s2 = e2.sym;
2133 if (s1 == s2) continue;
2134 Type st2 = types.memberType(site, s2);
2135 if (!types.overrideEquivalent(st1, st2) &&
2136 !checkNameClash((ClassSymbol)site.tsym, s1, s2)) {
2137 log.error(pos,
2138 "name.clash.same.erasure.no.override",
2139 s1, s1.location(),
2140 s2, s2.location());
2141 }
2142 }
2143 }
2144 //where
2145 private class ClashFilter implements Filter<Symbol> {
2147 Type site;
2149 ClashFilter(Type site) {
2150 this.site = site;
2151 }
2153 public boolean accepts(Symbol s) {
2154 return s.kind == MTH &&
2155 (s.flags() & (SYNTHETIC | CLASH)) == 0 &&
2156 s.isInheritedIn(site.tsym, types) &&
2157 !s.isConstructor();
2158 }
2159 }
2161 /** Report a conflict between a user symbol and a synthetic symbol.
2162 */
2163 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
2164 if (!sym.type.isErroneous()) {
2165 if (warnOnSyntheticConflicts) {
2166 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
2167 }
2168 else {
2169 log.error(pos, "synthetic.name.conflict", sym, sym.location());
2170 }
2171 }
2172 }
2174 /** Check that class c does not implement directly or indirectly
2175 * the same parameterized interface with two different argument lists.
2176 * @param pos Position to be used for error reporting.
2177 * @param type The type whose interfaces are checked.
2178 */
2179 void checkClassBounds(DiagnosticPosition pos, Type type) {
2180 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
2181 }
2182 //where
2183 /** Enter all interfaces of type `type' into the hash table `seensofar'
2184 * with their class symbol as key and their type as value. Make
2185 * sure no class is entered with two different types.
2186 */
2187 void checkClassBounds(DiagnosticPosition pos,
2188 Map<TypeSymbol,Type> seensofar,
2189 Type type) {
2190 if (type.isErroneous()) return;
2191 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
2192 Type it = l.head;
2193 Type oldit = seensofar.put(it.tsym, it);
2194 if (oldit != null) {
2195 List<Type> oldparams = oldit.allparams();
2196 List<Type> newparams = it.allparams();
2197 if (!types.containsTypeEquivalent(oldparams, newparams))
2198 log.error(pos, "cant.inherit.diff.arg",
2199 it.tsym, Type.toString(oldparams),
2200 Type.toString(newparams));
2201 }
2202 checkClassBounds(pos, seensofar, it);
2203 }
2204 Type st = types.supertype(type);
2205 if (st != null) checkClassBounds(pos, seensofar, st);
2206 }
2208 /** Enter interface into into set.
2209 * If it existed already, issue a "repeated interface" error.
2210 */
2211 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
2212 if (its.contains(it))
2213 log.error(pos, "repeated.interface");
2214 else {
2215 its.add(it);
2216 }
2217 }
2219 /* *************************************************************************
2220 * Check annotations
2221 **************************************************************************/
2223 /**
2224 * Recursively validate annotations values
2225 */
2226 void validateAnnotationTree(JCTree tree) {
2227 class AnnotationValidator extends TreeScanner {
2228 @Override
2229 public void visitAnnotation(JCAnnotation tree) {
2230 super.visitAnnotation(tree);
2231 validateAnnotation(tree);
2232 }
2233 }
2234 tree.accept(new AnnotationValidator());
2235 }
2237 /** Annotation types are restricted to primitives, String, an
2238 * enum, an annotation, Class, Class<?>, Class<? extends
2239 * Anything>, arrays of the preceding.
2240 */
2241 void validateAnnotationType(JCTree restype) {
2242 // restype may be null if an error occurred, so don't bother validating it
2243 if (restype != null) {
2244 validateAnnotationType(restype.pos(), restype.type);
2245 }
2246 }
2248 void validateAnnotationType(DiagnosticPosition pos, Type type) {
2249 if (type.isPrimitive()) return;
2250 if (types.isSameType(type, syms.stringType)) return;
2251 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
2252 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
2253 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
2254 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
2255 validateAnnotationType(pos, types.elemtype(type));
2256 return;
2257 }
2258 log.error(pos, "invalid.annotation.member.type");
2259 }
2261 /**
2262 * "It is also a compile-time error if any method declared in an
2263 * annotation type has a signature that is override-equivalent to
2264 * that of any public or protected method declared in class Object
2265 * or in the interface annotation.Annotation."
2266 *
2267 * @jls3 9.6 Annotation Types
2268 */
2269 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
2270 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
2271 Scope s = sup.tsym.members();
2272 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
2273 if (e.sym.kind == MTH &&
2274 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
2275 types.overrideEquivalent(m.type, e.sym.type))
2276 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
2277 }
2278 }
2279 }
2281 /** Check the annotations of a symbol.
2282 */
2283 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
2284 if (skipAnnotations) return;
2285 for (JCAnnotation a : annotations)
2286 validateAnnotation(a, s);
2287 }
2289 /** Check an annotation of a symbol.
2290 */
2291 public void validateAnnotation(JCAnnotation a, Symbol s) {
2292 validateAnnotationTree(a);
2294 if (!annotationApplicable(a, s))
2295 log.error(a.pos(), "annotation.type.not.applicable");
2297 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2298 if (!isOverrider(s))
2299 log.error(a.pos(), "method.does.not.override.superclass");
2300 }
2301 }
2303 /** Is s a method symbol that overrides a method in a superclass? */
2304 boolean isOverrider(Symbol s) {
2305 if (s.kind != MTH || s.isStatic())
2306 return false;
2307 MethodSymbol m = (MethodSymbol)s;
2308 TypeSymbol owner = (TypeSymbol)m.owner;
2309 for (Type sup : types.closure(owner.type)) {
2310 if (sup == owner.type)
2311 continue; // skip "this"
2312 Scope scope = sup.tsym.members();
2313 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
2314 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
2315 return true;
2316 }
2317 }
2318 return false;
2319 }
2321 /** Is the annotation applicable to the symbol? */
2322 boolean annotationApplicable(JCAnnotation a, Symbol s) {
2323 Attribute.Compound atTarget =
2324 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
2325 if (atTarget == null) return true;
2326 Attribute atValue = atTarget.member(names.value);
2327 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
2328 Attribute.Array arr = (Attribute.Array) atValue;
2329 for (Attribute app : arr.values) {
2330 if (!(app instanceof Attribute.Enum)) return true; // recovery
2331 Attribute.Enum e = (Attribute.Enum) app;
2332 if (e.value.name == names.TYPE)
2333 { if (s.kind == TYP) return true; }
2334 else if (e.value.name == names.FIELD)
2335 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
2336 else if (e.value.name == names.METHOD)
2337 { if (s.kind == MTH && !s.isConstructor()) return true; }
2338 else if (e.value.name == names.PARAMETER)
2339 { if (s.kind == VAR &&
2340 s.owner.kind == MTH &&
2341 (s.flags() & PARAMETER) != 0)
2342 return true;
2343 }
2344 else if (e.value.name == names.CONSTRUCTOR)
2345 { if (s.kind == MTH && s.isConstructor()) return true; }
2346 else if (e.value.name == names.LOCAL_VARIABLE)
2347 { if (s.kind == VAR && s.owner.kind == MTH &&
2348 (s.flags() & PARAMETER) == 0)
2349 return true;
2350 }
2351 else if (e.value.name == names.ANNOTATION_TYPE)
2352 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
2353 return true;
2354 }
2355 else if (e.value.name == names.PACKAGE)
2356 { if (s.kind == PCK) return true; }
2357 else if (e.value.name == names.TYPE_USE)
2358 { if (s.kind == TYP ||
2359 s.kind == VAR ||
2360 (s.kind == MTH && !s.isConstructor() &&
2361 s.type.getReturnType().tag != VOID))
2362 return true;
2363 }
2364 else
2365 return true; // recovery
2366 }
2367 return false;
2368 }
2370 /** Check an annotation value.
2371 */
2372 public void validateAnnotation(JCAnnotation a) {
2373 if (a.type.isErroneous()) return;
2375 // collect an inventory of the members (sorted alphabetically)
2376 Set<MethodSymbol> members = new TreeSet<MethodSymbol>(new Comparator<Symbol>() {
2377 public int compare(Symbol t, Symbol t1) {
2378 return t.name.compareTo(t1.name);
2379 }
2380 });
2381 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
2382 e != null;
2383 e = e.sibling)
2384 if (e.sym.kind == MTH)
2385 members.add((MethodSymbol) e.sym);
2387 // count them off as they're annotated
2388 for (JCTree arg : a.args) {
2389 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
2390 JCAssign assign = (JCAssign) arg;
2391 Symbol m = TreeInfo.symbol(assign.lhs);
2392 if (m == null || m.type.isErroneous()) continue;
2393 if (!members.remove(m))
2394 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
2395 m.name, a.type);
2396 }
2398 // all the remaining ones better have default values
2399 ListBuffer<Name> missingDefaults = ListBuffer.lb();
2400 for (MethodSymbol m : members) {
2401 if (m.defaultValue == null && !m.type.isErroneous()) {
2402 missingDefaults.append(m.name);
2403 }
2404 }
2405 if (missingDefaults.nonEmpty()) {
2406 String key = (missingDefaults.size() > 1)
2407 ? "annotation.missing.default.value.1"
2408 : "annotation.missing.default.value";
2409 log.error(a.pos(), key, a.type, missingDefaults);
2410 }
2412 // special case: java.lang.annotation.Target must not have
2413 // repeated values in its value member
2414 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
2415 a.args.tail == null)
2416 return;
2418 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
2419 JCAssign assign = (JCAssign) a.args.head;
2420 Symbol m = TreeInfo.symbol(assign.lhs);
2421 if (m.name != names.value) return;
2422 JCTree rhs = assign.rhs;
2423 if (rhs.getTag() != JCTree.NEWARRAY) return;
2424 JCNewArray na = (JCNewArray) rhs;
2425 Set<Symbol> targets = new HashSet<Symbol>();
2426 for (JCTree elem : na.elems) {
2427 if (!targets.add(TreeInfo.symbol(elem))) {
2428 log.error(elem.pos(), "repeated.annotation.target");
2429 }
2430 }
2431 }
2433 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
2434 if (allowAnnotations &&
2435 lint.isEnabled(LintCategory.DEP_ANN) &&
2436 (s.flags() & DEPRECATED) != 0 &&
2437 !syms.deprecatedType.isErroneous() &&
2438 s.attribute(syms.deprecatedType.tsym) == null) {
2439 log.warning(LintCategory.DEP_ANN,
2440 pos, "missing.deprecated.annotation");
2441 }
2442 }
2444 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
2445 if ((s.flags() & DEPRECATED) != 0 &&
2446 (other.flags() & DEPRECATED) == 0 &&
2447 s.outermostClass() != other.outermostClass()) {
2448 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
2449 @Override
2450 public void report() {
2451 warnDeprecated(pos, s);
2452 }
2453 });
2454 };
2455 }
2457 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
2458 if ((s.flags() & PROPRIETARY) != 0) {
2459 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
2460 public void report() {
2461 if (enableSunApiLintControl)
2462 warnSunApi(pos, "sun.proprietary", s);
2463 else
2464 log.strictWarning(pos, "sun.proprietary", s);
2465 }
2466 });
2467 }
2468 }
2470 /* *************************************************************************
2471 * Check for recursive annotation elements.
2472 **************************************************************************/
2474 /** Check for cycles in the graph of annotation elements.
2475 */
2476 void checkNonCyclicElements(JCClassDecl tree) {
2477 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
2478 Assert.check((tree.sym.flags_field & LOCKED) == 0);
2479 try {
2480 tree.sym.flags_field |= LOCKED;
2481 for (JCTree def : tree.defs) {
2482 if (def.getTag() != JCTree.METHODDEF) continue;
2483 JCMethodDecl meth = (JCMethodDecl)def;
2484 checkAnnotationResType(meth.pos(), meth.restype.type);
2485 }
2486 } finally {
2487 tree.sym.flags_field &= ~LOCKED;
2488 tree.sym.flags_field |= ACYCLIC_ANN;
2489 }
2490 }
2492 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
2493 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
2494 return;
2495 if ((tsym.flags_field & LOCKED) != 0) {
2496 log.error(pos, "cyclic.annotation.element");
2497 return;
2498 }
2499 try {
2500 tsym.flags_field |= LOCKED;
2501 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
2502 Symbol s = e.sym;
2503 if (s.kind != Kinds.MTH)
2504 continue;
2505 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
2506 }
2507 } finally {
2508 tsym.flags_field &= ~LOCKED;
2509 tsym.flags_field |= ACYCLIC_ANN;
2510 }
2511 }
2513 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
2514 switch (type.tag) {
2515 case TypeTags.CLASS:
2516 if ((type.tsym.flags() & ANNOTATION) != 0)
2517 checkNonCyclicElementsInternal(pos, type.tsym);
2518 break;
2519 case TypeTags.ARRAY:
2520 checkAnnotationResType(pos, types.elemtype(type));
2521 break;
2522 default:
2523 break; // int etc
2524 }
2525 }
2527 /* *************************************************************************
2528 * Check for cycles in the constructor call graph.
2529 **************************************************************************/
2531 /** Check for cycles in the graph of constructors calling other
2532 * constructors.
2533 */
2534 void checkCyclicConstructors(JCClassDecl tree) {
2535 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
2537 // enter each constructor this-call into the map
2538 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2539 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
2540 if (app == null) continue;
2541 JCMethodDecl meth = (JCMethodDecl) l.head;
2542 if (TreeInfo.name(app.meth) == names._this) {
2543 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
2544 } else {
2545 meth.sym.flags_field |= ACYCLIC;
2546 }
2547 }
2549 // Check for cycles in the map
2550 Symbol[] ctors = new Symbol[0];
2551 ctors = callMap.keySet().toArray(ctors);
2552 for (Symbol caller : ctors) {
2553 checkCyclicConstructor(tree, caller, callMap);
2554 }
2555 }
2557 /** Look in the map to see if the given constructor is part of a
2558 * call cycle.
2559 */
2560 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
2561 Map<Symbol,Symbol> callMap) {
2562 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
2563 if ((ctor.flags_field & LOCKED) != 0) {
2564 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
2565 "recursive.ctor.invocation");
2566 } else {
2567 ctor.flags_field |= LOCKED;
2568 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2569 ctor.flags_field &= ~LOCKED;
2570 }
2571 ctor.flags_field |= ACYCLIC;
2572 }
2573 }
2575 /* *************************************************************************
2576 * Miscellaneous
2577 **************************************************************************/
2579 /**
2580 * Return the opcode of the operator but emit an error if it is an
2581 * error.
2582 * @param pos position for error reporting.
2583 * @param operator an operator
2584 * @param tag a tree tag
2585 * @param left type of left hand side
2586 * @param right type of right hand side
2587 */
2588 int checkOperator(DiagnosticPosition pos,
2589 OperatorSymbol operator,
2590 int tag,
2591 Type left,
2592 Type right) {
2593 if (operator.opcode == ByteCodes.error) {
2594 log.error(pos,
2595 "operator.cant.be.applied.1",
2596 treeinfo.operatorName(tag),
2597 left, right);
2598 }
2599 return operator.opcode;
2600 }
2603 /**
2604 * Check for division by integer constant zero
2605 * @param pos Position for error reporting.
2606 * @param operator The operator for the expression
2607 * @param operand The right hand operand for the expression
2608 */
2609 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
2610 if (operand.constValue() != null
2611 && lint.isEnabled(LintCategory.DIVZERO)
2612 && operand.tag <= LONG
2613 && ((Number) (operand.constValue())).longValue() == 0) {
2614 int opc = ((OperatorSymbol)operator).opcode;
2615 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
2616 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
2617 log.warning(LintCategory.DIVZERO, pos, "div.zero");
2618 }
2619 }
2620 }
2622 /**
2623 * Check for empty statements after if
2624 */
2625 void checkEmptyIf(JCIf tree) {
2626 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(LintCategory.EMPTY))
2627 log.warning(LintCategory.EMPTY, tree.thenpart.pos(), "empty.if");
2628 }
2630 /** Check that symbol is unique in given scope.
2631 * @param pos Position for error reporting.
2632 * @param sym The symbol.
2633 * @param s The scope.
2634 */
2635 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2636 if (sym.type.isErroneous())
2637 return true;
2638 if (sym.owner.name == names.any) return false;
2639 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2640 if (sym != e.sym &&
2641 (e.sym.flags() & CLASH) == 0 &&
2642 sym.kind == e.sym.kind &&
2643 sym.name != names.error &&
2644 (sym.kind != MTH || types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
2645 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS)) {
2646 varargsDuplicateError(pos, sym, e.sym);
2647 return true;
2648 } else if (sym.kind == MTH && !hasSameSignature(sym.type, e.sym.type)) {
2649 duplicateErasureError(pos, sym, e.sym);
2650 sym.flags_field |= CLASH;
2651 return true;
2652 } else {
2653 duplicateError(pos, e.sym);
2654 return false;
2655 }
2656 }
2657 }
2658 return true;
2659 }
2660 //where
2661 boolean hasSameSignature(Type mt1, Type mt2) {
2662 if (mt1.tag == FORALL && mt2.tag == FORALL) {
2663 ForAll fa1 = (ForAll)mt1;
2664 ForAll fa2 = (ForAll)mt2;
2665 mt2 = types.subst(fa2, fa2.tvars, fa1.tvars);
2666 }
2667 return types.hasSameArgs(mt1.asMethodType(), mt2.asMethodType());
2668 }
2670 /** Report duplicate declaration error.
2671 */
2672 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
2673 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
2674 log.error(pos, "name.clash.same.erasure", sym1, sym2);
2675 }
2676 }
2678 /** Check that single-type import is not already imported or top-level defined,
2679 * but make an exception for two single-type imports which denote the same type.
2680 * @param pos Position for error reporting.
2681 * @param sym The symbol.
2682 * @param s The scope
2683 */
2684 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2685 return checkUniqueImport(pos, sym, s, false);
2686 }
2688 /** Check that static single-type import is not already imported or top-level defined,
2689 * but make an exception for two single-type imports which denote the same type.
2690 * @param pos Position for error reporting.
2691 * @param sym The symbol.
2692 * @param s The scope
2693 * @param staticImport Whether or not this was a static import
2694 */
2695 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2696 return checkUniqueImport(pos, sym, s, true);
2697 }
2699 /** Check that single-type import is not already imported or top-level defined,
2700 * but make an exception for two single-type imports which denote the same type.
2701 * @param pos Position for error reporting.
2702 * @param sym The symbol.
2703 * @param s The scope.
2704 * @param staticImport Whether or not this was a static import
2705 */
2706 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2707 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2708 // is encountered class entered via a class declaration?
2709 boolean isClassDecl = e.scope == s;
2710 if ((isClassDecl || sym != e.sym) &&
2711 sym.kind == e.sym.kind &&
2712 sym.name != names.error) {
2713 if (!e.sym.type.isErroneous()) {
2714 String what = e.sym.toString();
2715 if (!isClassDecl) {
2716 if (staticImport)
2717 log.error(pos, "already.defined.static.single.import", what);
2718 else
2719 log.error(pos, "already.defined.single.import", what);
2720 }
2721 else if (sym != e.sym)
2722 log.error(pos, "already.defined.this.unit", what);
2723 }
2724 return false;
2725 }
2726 }
2727 return true;
2728 }
2730 /** Check that a qualified name is in canonical form (for import decls).
2731 */
2732 public void checkCanonical(JCTree tree) {
2733 if (!isCanonical(tree))
2734 log.error(tree.pos(), "import.requires.canonical",
2735 TreeInfo.symbol(tree));
2736 }
2737 // where
2738 private boolean isCanonical(JCTree tree) {
2739 while (tree.getTag() == JCTree.SELECT) {
2740 JCFieldAccess s = (JCFieldAccess) tree;
2741 if (s.sym.owner != TreeInfo.symbol(s.selected))
2742 return false;
2743 tree = s.selected;
2744 }
2745 return true;
2746 }
2748 private class ConversionWarner extends Warner {
2749 final String uncheckedKey;
2750 final Type found;
2751 final Type expected;
2752 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
2753 super(pos);
2754 this.uncheckedKey = uncheckedKey;
2755 this.found = found;
2756 this.expected = expected;
2757 }
2759 @Override
2760 public void warn(LintCategory lint) {
2761 boolean warned = this.warned;
2762 super.warn(lint);
2763 if (warned) return; // suppress redundant diagnostics
2764 switch (lint) {
2765 case UNCHECKED:
2766 Check.this.warnUnchecked(pos(), "prob.found.req", diags.fragment(uncheckedKey), found, expected);
2767 break;
2768 case VARARGS:
2769 if (method != null &&
2770 method.attribute(syms.trustMeType.tsym) != null &&
2771 isTrustMeAllowedOnMethod(method) &&
2772 !types.isReifiable(method.type.getParameterTypes().last())) {
2773 Check.this.warnUnsafeVararg(pos(), "varargs.unsafe.use.varargs.param", method.params.last());
2774 }
2775 break;
2776 default:
2777 throw new AssertionError("Unexpected lint: " + lint);
2778 }
2779 }
2780 }
2782 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2783 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2784 }
2786 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2787 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2788 }
2789 }
