Thu, 04 Oct 2012 13:04:53 +0100
7177387: Add target-typing support in method context
Summary: Add support for deferred types and speculative attribution
Reviewed-by: jjg, dlsmith
1 /*
2 * Copyright (c) 1999, 2012, 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.*;
43 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
44 import com.sun.tools.javac.comp.Infer.InferenceContext;
45 import com.sun.tools.javac.comp.Infer.InferenceContext.FreeTypeListener;
47 import static com.sun.tools.javac.code.Flags.*;
48 import static com.sun.tools.javac.code.Flags.ANNOTATION;
49 import static com.sun.tools.javac.code.Flags.SYNCHRONIZED;
50 import static com.sun.tools.javac.code.Kinds.*;
51 import static com.sun.tools.javac.code.TypeTags.*;
52 import static com.sun.tools.javac.code.TypeTags.WILDCARD;
54 import static com.sun.tools.javac.tree.JCTree.Tag.*;
56 /** Type checking helper class for the attribution phase.
57 *
58 * <p><b>This is NOT part of any supported API.
59 * If you write code that depends on this, you do so at your own risk.
60 * This code and its internal interfaces are subject to change or
61 * deletion without notice.</b>
62 */
63 public class Check {
64 protected static final Context.Key<Check> checkKey =
65 new Context.Key<Check>();
67 private final Names names;
68 private final Log log;
69 private final Resolve rs;
70 private final Symtab syms;
71 private final Enter enter;
72 private final DeferredAttr deferredAttr;
73 private final Infer infer;
74 private final Types types;
75 private final JCDiagnostic.Factory diags;
76 private boolean warnOnSyntheticConflicts;
77 private boolean suppressAbortOnBadClassFile;
78 private boolean enableSunApiLintControl;
79 private final TreeInfo treeinfo;
81 // The set of lint options currently in effect. It is initialized
82 // from the context, and then is set/reset as needed by Attr as it
83 // visits all the various parts of the trees during attribution.
84 private Lint lint;
86 // The method being analyzed in Attr - it is set/reset as needed by
87 // Attr as it visits new method declarations.
88 private MethodSymbol method;
90 public static Check instance(Context context) {
91 Check instance = context.get(checkKey);
92 if (instance == null)
93 instance = new Check(context);
94 return instance;
95 }
97 protected Check(Context context) {
98 context.put(checkKey, this);
100 names = Names.instance(context);
101 log = Log.instance(context);
102 rs = Resolve.instance(context);
103 syms = Symtab.instance(context);
104 enter = Enter.instance(context);
105 deferredAttr = DeferredAttr.instance(context);
106 infer = Infer.instance(context);
107 this.types = Types.instance(context);
108 diags = JCDiagnostic.Factory.instance(context);
109 Options options = Options.instance(context);
110 lint = Lint.instance(context);
111 treeinfo = TreeInfo.instance(context);
113 Source source = Source.instance(context);
114 allowGenerics = source.allowGenerics();
115 allowVarargs = source.allowVarargs();
116 allowAnnotations = source.allowAnnotations();
117 allowCovariantReturns = source.allowCovariantReturns();
118 allowSimplifiedVarargs = source.allowSimplifiedVarargs();
119 complexInference = options.isSet("complexinference");
120 warnOnSyntheticConflicts = options.isSet("warnOnSyntheticConflicts");
121 suppressAbortOnBadClassFile = options.isSet("suppressAbortOnBadClassFile");
122 enableSunApiLintControl = options.isSet("enableSunApiLintControl");
124 Target target = Target.instance(context);
125 syntheticNameChar = target.syntheticNameChar();
127 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
128 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
129 boolean verboseSunApi = lint.isEnabled(LintCategory.SUNAPI);
130 boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
132 deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
133 enforceMandatoryWarnings, "deprecated", LintCategory.DEPRECATION);
134 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
135 enforceMandatoryWarnings, "unchecked", LintCategory.UNCHECKED);
136 sunApiHandler = new MandatoryWarningHandler(log, verboseSunApi,
137 enforceMandatoryWarnings, "sunapi", null);
139 deferredLintHandler = DeferredLintHandler.immediateHandler;
140 }
142 /** Switch: generics enabled?
143 */
144 boolean allowGenerics;
146 /** Switch: varargs enabled?
147 */
148 boolean allowVarargs;
150 /** Switch: annotations enabled?
151 */
152 boolean allowAnnotations;
154 /** Switch: covariant returns enabled?
155 */
156 boolean allowCovariantReturns;
158 /** Switch: simplified varargs enabled?
159 */
160 boolean allowSimplifiedVarargs;
162 /** Switch: -complexinference option set?
163 */
164 boolean complexInference;
166 /** Character for synthetic names
167 */
168 char syntheticNameChar;
170 /** A table mapping flat names of all compiled classes in this run to their
171 * symbols; maintained from outside.
172 */
173 public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
175 /** A handler for messages about deprecated usage.
176 */
177 private MandatoryWarningHandler deprecationHandler;
179 /** A handler for messages about unchecked or unsafe usage.
180 */
181 private MandatoryWarningHandler uncheckedHandler;
183 /** A handler for messages about using proprietary API.
184 */
185 private MandatoryWarningHandler sunApiHandler;
187 /** A handler for deferred lint warnings.
188 */
189 private DeferredLintHandler deferredLintHandler;
191 /* *************************************************************************
192 * Errors and Warnings
193 **************************************************************************/
195 Lint setLint(Lint newLint) {
196 Lint prev = lint;
197 lint = newLint;
198 return prev;
199 }
201 DeferredLintHandler setDeferredLintHandler(DeferredLintHandler newDeferredLintHandler) {
202 DeferredLintHandler prev = deferredLintHandler;
203 deferredLintHandler = newDeferredLintHandler;
204 return prev;
205 }
207 MethodSymbol setMethod(MethodSymbol newMethod) {
208 MethodSymbol prev = method;
209 method = newMethod;
210 return prev;
211 }
213 /** Warn about deprecated symbol.
214 * @param pos Position to be used for error reporting.
215 * @param sym The deprecated symbol.
216 */
217 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
218 if (!lint.isSuppressed(LintCategory.DEPRECATION))
219 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
220 }
222 /** Warn about unchecked operation.
223 * @param pos Position to be used for error reporting.
224 * @param msg A string describing the problem.
225 */
226 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
227 if (!lint.isSuppressed(LintCategory.UNCHECKED))
228 uncheckedHandler.report(pos, msg, args);
229 }
231 /** Warn about unsafe vararg method decl.
232 * @param pos Position to be used for error reporting.
233 * @param sym The deprecated symbol.
234 */
235 void warnUnsafeVararg(DiagnosticPosition pos, String key, Object... args) {
236 if (lint.isEnabled(LintCategory.VARARGS) && allowSimplifiedVarargs)
237 log.warning(LintCategory.VARARGS, pos, key, args);
238 }
240 /** Warn about using proprietary API.
241 * @param pos Position to be used for error reporting.
242 * @param msg A string describing the problem.
243 */
244 public void warnSunApi(DiagnosticPosition pos, String msg, Object... args) {
245 if (!lint.isSuppressed(LintCategory.SUNAPI))
246 sunApiHandler.report(pos, msg, args);
247 }
249 public void warnStatic(DiagnosticPosition pos, String msg, Object... args) {
250 if (lint.isEnabled(LintCategory.STATIC))
251 log.warning(LintCategory.STATIC, pos, msg, args);
252 }
254 /**
255 * Report any deferred diagnostics.
256 */
257 public void reportDeferredDiagnostics() {
258 deprecationHandler.reportDeferredDiagnostic();
259 uncheckedHandler.reportDeferredDiagnostic();
260 sunApiHandler.reportDeferredDiagnostic();
261 }
264 /** Report a failure to complete a class.
265 * @param pos Position to be used for error reporting.
266 * @param ex The failure to report.
267 */
268 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
269 log.error(pos, "cant.access", ex.sym, ex.getDetailValue());
270 if (ex instanceof ClassReader.BadClassFile
271 && !suppressAbortOnBadClassFile) throw new Abort();
272 else return syms.errType;
273 }
275 /** Report an error that wrong type tag was found.
276 * @param pos Position to be used for error reporting.
277 * @param required An internationalized string describing the type tag
278 * required.
279 * @param found The type that was found.
280 */
281 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
282 // this error used to be raised by the parser,
283 // but has been delayed to this point:
284 if (found instanceof Type && ((Type)found).tag == VOID) {
285 log.error(pos, "illegal.start.of.type");
286 return syms.errType;
287 }
288 log.error(pos, "type.found.req", found, required);
289 return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
290 }
292 /** Report an error that symbol cannot be referenced before super
293 * has been called.
294 * @param pos Position to be used for error reporting.
295 * @param sym The referenced symbol.
296 */
297 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
298 log.error(pos, "cant.ref.before.ctor.called", sym);
299 }
301 /** Report duplicate declaration error.
302 */
303 void duplicateError(DiagnosticPosition pos, Symbol sym) {
304 if (!sym.type.isErroneous()) {
305 Symbol location = sym.location();
306 if (location.kind == MTH &&
307 ((MethodSymbol)location).isStaticOrInstanceInit()) {
308 log.error(pos, "already.defined.in.clinit", kindName(sym), sym,
309 kindName(sym.location()), kindName(sym.location().enclClass()),
310 sym.location().enclClass());
311 } else {
312 log.error(pos, "already.defined", kindName(sym), sym,
313 kindName(sym.location()), sym.location());
314 }
315 }
316 }
318 /** Report array/varargs duplicate declaration
319 */
320 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
321 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
322 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
323 }
324 }
326 /* ************************************************************************
327 * duplicate declaration checking
328 *************************************************************************/
330 /** Check that variable does not hide variable with same name in
331 * immediately enclosing local scope.
332 * @param pos Position for error reporting.
333 * @param v The symbol.
334 * @param s The scope.
335 */
336 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
337 if (s.next != null) {
338 for (Scope.Entry e = s.next.lookup(v.name);
339 e.scope != null && e.sym.owner == v.owner;
340 e = e.next()) {
341 if (e.sym.kind == VAR &&
342 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
343 v.name != names.error) {
344 duplicateError(pos, e.sym);
345 return;
346 }
347 }
348 }
349 }
351 /** Check that a class or interface does not hide a class or
352 * interface with same name in immediately enclosing local scope.
353 * @param pos Position for error reporting.
354 * @param c The symbol.
355 * @param s The scope.
356 */
357 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
358 if (s.next != null) {
359 for (Scope.Entry e = s.next.lookup(c.name);
360 e.scope != null && e.sym.owner == c.owner;
361 e = e.next()) {
362 if (e.sym.kind == TYP && e.sym.type.tag != TYPEVAR &&
363 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
364 c.name != names.error) {
365 duplicateError(pos, e.sym);
366 return;
367 }
368 }
369 }
370 }
372 /** Check that class does not have the same name as one of
373 * its enclosing classes, or as a class defined in its enclosing scope.
374 * return true if class is unique in its enclosing scope.
375 * @param pos Position for error reporting.
376 * @param name The class name.
377 * @param s The enclosing scope.
378 */
379 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
380 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
381 if (e.sym.kind == TYP && e.sym.name != names.error) {
382 duplicateError(pos, e.sym);
383 return false;
384 }
385 }
386 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
387 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
388 duplicateError(pos, sym);
389 return true;
390 }
391 }
392 return true;
393 }
395 /* *************************************************************************
396 * Class name generation
397 **************************************************************************/
399 /** Return name of local class.
400 * This is of the form <enclClass> $ n <classname>
401 * where
402 * enclClass is the flat name of the enclosing class,
403 * classname is the simple name of the local class
404 */
405 Name localClassName(ClassSymbol c) {
406 for (int i=1; ; i++) {
407 Name flatname = names.
408 fromString("" + c.owner.enclClass().flatname +
409 syntheticNameChar + i +
410 c.name);
411 if (compiled.get(flatname) == null) return flatname;
412 }
413 }
415 /* *************************************************************************
416 * Type Checking
417 **************************************************************************/
419 /**
420 * A check context is an object that can be used to perform compatibility
421 * checks - depending on the check context, meaning of 'compatibility' might
422 * vary significantly.
423 */
424 interface CheckContext {
425 /**
426 * Is type 'found' compatible with type 'req' in given context
427 */
428 boolean compatible(Type found, Type req, Warner warn);
429 /**
430 * Report a check error
431 */
432 void report(DiagnosticPosition pos, JCDiagnostic details);
433 /**
434 * Obtain a warner for this check context
435 */
436 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req);
438 public Infer.InferenceContext inferenceContext();
440 public DeferredAttr.DeferredAttrContext deferredAttrContext();
441 }
443 /**
444 * This class represent a check context that is nested within another check
445 * context - useful to check sub-expressions. The default behavior simply
446 * redirects all method calls to the enclosing check context leveraging
447 * the forwarding pattern.
448 */
449 static class NestedCheckContext implements CheckContext {
450 CheckContext enclosingContext;
452 NestedCheckContext(CheckContext enclosingContext) {
453 this.enclosingContext = enclosingContext;
454 }
456 public boolean compatible(Type found, Type req, Warner warn) {
457 return enclosingContext.compatible(found, req, warn);
458 }
460 public void report(DiagnosticPosition pos, JCDiagnostic details) {
461 enclosingContext.report(pos, details);
462 }
464 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
465 return enclosingContext.checkWarner(pos, found, req);
466 }
468 public Infer.InferenceContext inferenceContext() {
469 return enclosingContext.inferenceContext();
470 }
472 public DeferredAttrContext deferredAttrContext() {
473 return enclosingContext.deferredAttrContext();
474 }
475 }
477 /**
478 * Check context to be used when evaluating assignment/return statements
479 */
480 CheckContext basicHandler = new CheckContext() {
481 public void report(DiagnosticPosition pos, JCDiagnostic details) {
482 log.error(pos, "prob.found.req", details);
483 }
484 public boolean compatible(Type found, Type req, Warner warn) {
485 return types.isAssignable(found, req, warn);
486 }
488 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
489 return convertWarner(pos, found, req);
490 }
492 public InferenceContext inferenceContext() {
493 return infer.emptyContext;
494 }
496 public DeferredAttrContext deferredAttrContext() {
497 return deferredAttr.emptyDeferredAttrContext;
498 }
499 };
501 /** Check that a given type is assignable to a given proto-type.
502 * If it is, return the type, otherwise return errType.
503 * @param pos Position to be used for error reporting.
504 * @param found The type that was found.
505 * @param req The type that was required.
506 */
507 Type checkType(DiagnosticPosition pos, Type found, Type req) {
508 return checkType(pos, found, req, basicHandler);
509 }
511 Type checkType(final DiagnosticPosition pos, final Type found, final Type req, final CheckContext checkContext) {
512 final Infer.InferenceContext inferenceContext = checkContext.inferenceContext();
513 if (inferenceContext.free(req)) {
514 inferenceContext.addFreeTypeListener(List.of(req), new FreeTypeListener() {
515 @Override
516 public void typesInferred(InferenceContext inferenceContext) {
517 checkType(pos, found, inferenceContext.asInstType(req, types), checkContext);
518 }
519 });
520 }
521 if (req.tag == ERROR)
522 return req;
523 if (req.tag == NONE)
524 return found;
525 if (checkContext.compatible(found, req, checkContext.checkWarner(pos, found, req))) {
526 return found;
527 } else {
528 if (found.tag <= DOUBLE && req.tag <= DOUBLE) {
529 checkContext.report(pos, diags.fragment("possible.loss.of.precision", found, req));
530 return types.createErrorType(found);
531 }
532 checkContext.report(pos, diags.fragment("inconvertible.types", found, req));
533 return types.createErrorType(found);
534 }
535 }
537 /** Check that a given type can be cast to a given target type.
538 * Return the result of the cast.
539 * @param pos Position to be used for error reporting.
540 * @param found The type that is being cast.
541 * @param req The target type of the cast.
542 */
543 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
544 return checkCastable(pos, found, req, basicHandler);
545 }
546 Type checkCastable(DiagnosticPosition pos, Type found, Type req, CheckContext checkContext) {
547 if (types.isCastable(found, req, castWarner(pos, found, req))) {
548 return req;
549 } else {
550 checkContext.report(pos, diags.fragment("inconvertible.types", found, req));
551 return types.createErrorType(found);
552 }
553 }
555 /** Check for redundant casts (i.e. where source type is a subtype of target type)
556 * The problem should only be reported for non-292 cast
557 */
558 public void checkRedundantCast(Env<AttrContext> env, JCTypeCast tree) {
559 if (!tree.type.isErroneous() &&
560 (env.info.lint == null || env.info.lint.isEnabled(Lint.LintCategory.CAST))
561 && types.isSameType(tree.expr.type, tree.clazz.type)
562 && !is292targetTypeCast(tree)) {
563 log.warning(Lint.LintCategory.CAST,
564 tree.pos(), "redundant.cast", tree.expr.type);
565 }
566 }
567 //where
568 private boolean is292targetTypeCast(JCTypeCast tree) {
569 boolean is292targetTypeCast = false;
570 JCExpression expr = TreeInfo.skipParens(tree.expr);
571 if (expr.hasTag(APPLY)) {
572 JCMethodInvocation apply = (JCMethodInvocation)expr;
573 Symbol sym = TreeInfo.symbol(apply.meth);
574 is292targetTypeCast = sym != null &&
575 sym.kind == MTH &&
576 (sym.flags() & HYPOTHETICAL) != 0;
577 }
578 return is292targetTypeCast;
579 }
583 //where
584 /** Is type a type variable, or a (possibly multi-dimensional) array of
585 * type variables?
586 */
587 boolean isTypeVar(Type t) {
588 return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
589 }
591 /** Check that a type is within some bounds.
592 *
593 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
594 * type argument.
595 * @param pos Position to be used for error reporting.
596 * @param a The type that should be bounded by bs.
597 * @param bs The bound.
598 */
599 private boolean checkExtends(Type a, Type bound) {
600 if (a.isUnbound()) {
601 return true;
602 } else if (a.tag != WILDCARD) {
603 a = types.upperBound(a);
604 return types.isSubtype(a, bound);
605 } else if (a.isExtendsBound()) {
606 return types.isCastable(bound, types.upperBound(a), Warner.noWarnings);
607 } else if (a.isSuperBound()) {
608 return !types.notSoftSubtype(types.lowerBound(a), bound);
609 }
610 return true;
611 }
613 /** Check that type is different from 'void'.
614 * @param pos Position to be used for error reporting.
615 * @param t The type to be checked.
616 */
617 Type checkNonVoid(DiagnosticPosition pos, Type t) {
618 if (t.tag == VOID) {
619 log.error(pos, "void.not.allowed.here");
620 return types.createErrorType(t);
621 } else {
622 return t;
623 }
624 }
626 /** Check that type is a class or interface type.
627 * @param pos Position to be used for error reporting.
628 * @param t The type to be checked.
629 */
630 Type checkClassType(DiagnosticPosition pos, Type t) {
631 if (t.tag != CLASS && t.tag != ERROR)
632 return typeTagError(pos,
633 diags.fragment("type.req.class"),
634 (t.tag == TYPEVAR)
635 ? diags.fragment("type.parameter", t)
636 : t);
637 else
638 return t;
639 }
641 /** Check that type is a class or interface type.
642 * @param pos Position to be used for error reporting.
643 * @param t The type to be checked.
644 * @param noBounds True if type bounds are illegal here.
645 */
646 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
647 t = checkClassType(pos, t);
648 if (noBounds && t.isParameterized()) {
649 List<Type> args = t.getTypeArguments();
650 while (args.nonEmpty()) {
651 if (args.head.tag == WILDCARD)
652 return typeTagError(pos,
653 diags.fragment("type.req.exact"),
654 args.head);
655 args = args.tail;
656 }
657 }
658 return t;
659 }
661 /** Check that type is a reifiable class, interface or array type.
662 * @param pos Position to be used for error reporting.
663 * @param t The type to be checked.
664 */
665 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
666 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
667 return typeTagError(pos,
668 diags.fragment("type.req.class.array"),
669 t);
670 } else if (!types.isReifiable(t)) {
671 log.error(pos, "illegal.generic.type.for.instof");
672 return types.createErrorType(t);
673 } else {
674 return t;
675 }
676 }
678 /** Check that type is a reference type, i.e. a class, interface or array type
679 * or a type variable.
680 * @param pos Position to be used for error reporting.
681 * @param t The type to be checked.
682 */
683 Type checkRefType(DiagnosticPosition pos, Type t) {
684 switch (t.tag) {
685 case CLASS:
686 case ARRAY:
687 case TYPEVAR:
688 case WILDCARD:
689 case ERROR:
690 return t;
691 default:
692 return typeTagError(pos,
693 diags.fragment("type.req.ref"),
694 t);
695 }
696 }
698 /** Check that each type is a reference type, i.e. a class, interface or array type
699 * or a type variable.
700 * @param trees Original trees, used for error reporting.
701 * @param types The types to be checked.
702 */
703 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
704 List<JCExpression> tl = trees;
705 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
706 l.head = checkRefType(tl.head.pos(), l.head);
707 tl = tl.tail;
708 }
709 return types;
710 }
712 /** Check that type is a null or reference type.
713 * @param pos Position to be used for error reporting.
714 * @param t The type to be checked.
715 */
716 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
717 switch (t.tag) {
718 case CLASS:
719 case ARRAY:
720 case TYPEVAR:
721 case WILDCARD:
722 case BOT:
723 case ERROR:
724 return t;
725 default:
726 return typeTagError(pos,
727 diags.fragment("type.req.ref"),
728 t);
729 }
730 }
732 /** Check that flag set does not contain elements of two conflicting sets. s
733 * Return true if it doesn't.
734 * @param pos Position to be used for error reporting.
735 * @param flags The set of flags to be checked.
736 * @param set1 Conflicting flags set #1.
737 * @param set2 Conflicting flags set #2.
738 */
739 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
740 if ((flags & set1) != 0 && (flags & set2) != 0) {
741 log.error(pos,
742 "illegal.combination.of.modifiers",
743 asFlagSet(TreeInfo.firstFlag(flags & set1)),
744 asFlagSet(TreeInfo.firstFlag(flags & set2)));
745 return false;
746 } else
747 return true;
748 }
750 /** Check that usage of diamond operator is correct (i.e. diamond should not
751 * be used with non-generic classes or in anonymous class creation expressions)
752 */
753 Type checkDiamond(JCNewClass tree, Type t) {
754 if (!TreeInfo.isDiamond(tree) ||
755 t.isErroneous()) {
756 return checkClassType(tree.clazz.pos(), t, true);
757 } else if (tree.def != null) {
758 log.error(tree.clazz.pos(),
759 "cant.apply.diamond.1",
760 t, diags.fragment("diamond.and.anon.class", t));
761 return types.createErrorType(t);
762 } else if (t.tsym.type.getTypeArguments().isEmpty()) {
763 log.error(tree.clazz.pos(),
764 "cant.apply.diamond.1",
765 t, diags.fragment("diamond.non.generic", t));
766 return types.createErrorType(t);
767 } else if (tree.typeargs != null &&
768 tree.typeargs.nonEmpty()) {
769 log.error(tree.clazz.pos(),
770 "cant.apply.diamond.1",
771 t, diags.fragment("diamond.and.explicit.params", t));
772 return types.createErrorType(t);
773 } else {
774 return t;
775 }
776 }
778 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
779 MethodSymbol m = tree.sym;
780 if (!allowSimplifiedVarargs) return;
781 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
782 Type varargElemType = null;
783 if (m.isVarArgs()) {
784 varargElemType = types.elemtype(tree.params.last().type);
785 }
786 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
787 if (varargElemType != null) {
788 log.error(tree,
789 "varargs.invalid.trustme.anno",
790 syms.trustMeType.tsym,
791 diags.fragment("varargs.trustme.on.virtual.varargs", m));
792 } else {
793 log.error(tree,
794 "varargs.invalid.trustme.anno",
795 syms.trustMeType.tsym,
796 diags.fragment("varargs.trustme.on.non.varargs.meth", m));
797 }
798 } else if (hasTrustMeAnno && varargElemType != null &&
799 types.isReifiable(varargElemType)) {
800 warnUnsafeVararg(tree,
801 "varargs.redundant.trustme.anno",
802 syms.trustMeType.tsym,
803 diags.fragment("varargs.trustme.on.reifiable.varargs", varargElemType));
804 }
805 else if (!hasTrustMeAnno && varargElemType != null &&
806 !types.isReifiable(varargElemType)) {
807 warnUnchecked(tree.params.head.pos(), "unchecked.varargs.non.reifiable.type", varargElemType);
808 }
809 }
810 //where
811 private boolean isTrustMeAllowedOnMethod(Symbol s) {
812 return (s.flags() & VARARGS) != 0 &&
813 (s.isConstructor() ||
814 (s.flags() & (STATIC | FINAL)) != 0);
815 }
817 Type checkMethod(Type owntype,
818 Symbol sym,
819 Env<AttrContext> env,
820 final List<JCExpression> argtrees,
821 List<Type> argtypes,
822 boolean useVarargs,
823 boolean unchecked) {
824 // System.out.println("call : " + env.tree);
825 // System.out.println("method : " + owntype);
826 // System.out.println("actuals: " + argtypes);
827 List<Type> formals = owntype.getParameterTypes();
828 Type last = useVarargs ? formals.last() : null;
829 if (sym.name==names.init &&
830 sym.owner == syms.enumSym)
831 formals = formals.tail.tail;
832 List<JCExpression> args = argtrees;
833 DeferredAttr.DeferredTypeMap checkDeferredMap =
834 deferredAttr.new DeferredTypeMap(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
835 while (formals.head != last) {
836 JCTree arg = args.head;
837 Warner warn = convertWarner(arg.pos(), arg.type, formals.head);
838 assertConvertible(arg, arg.type, formals.head, warn);
839 args = args.tail;
840 formals = formals.tail;
841 }
842 if (useVarargs) {
843 Type varArg = types.elemtype(last);
844 while (args.tail != null) {
845 JCTree arg = args.head;
846 Warner warn = convertWarner(arg.pos(), arg.type, varArg);
847 assertConvertible(arg, arg.type, varArg, warn);
848 args = args.tail;
849 }
850 } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
851 // non-varargs call to varargs method
852 Type varParam = owntype.getParameterTypes().last();
853 Type lastArg = checkDeferredMap.apply(argtypes.last());
854 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
855 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
856 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
857 types.elemtype(varParam), varParam);
858 }
859 if (unchecked) {
860 warnUnchecked(env.tree.pos(),
861 "unchecked.meth.invocation.applied",
862 kindName(sym),
863 sym.name,
864 rs.methodArguments(sym.type.getParameterTypes()),
865 rs.methodArguments(Type.map(argtypes, checkDeferredMap)),
866 kindName(sym.location()),
867 sym.location());
868 owntype = new MethodType(owntype.getParameterTypes(),
869 types.erasure(owntype.getReturnType()),
870 types.erasure(owntype.getThrownTypes()),
871 syms.methodClass);
872 }
873 if (useVarargs) {
874 JCTree tree = env.tree;
875 Type argtype = owntype.getParameterTypes().last();
876 if (!types.isReifiable(argtype) &&
877 (!allowSimplifiedVarargs ||
878 sym.attribute(syms.trustMeType.tsym) == null ||
879 !isTrustMeAllowedOnMethod(sym))) {
880 warnUnchecked(env.tree.pos(),
881 "unchecked.generic.array.creation",
882 argtype);
883 }
884 Type elemtype = types.elemtype(argtype);
885 switch (tree.getTag()) {
886 case APPLY:
887 ((JCMethodInvocation) tree).varargsElement = elemtype;
888 break;
889 case NEWCLASS:
890 ((JCNewClass) tree).varargsElement = elemtype;
891 break;
892 default:
893 throw new AssertionError(""+tree);
894 }
895 }
896 return owntype;
897 }
898 //where
899 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
900 if (types.isConvertible(actual, formal, warn))
901 return;
903 if (formal.isCompound()
904 && types.isSubtype(actual, types.supertype(formal))
905 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
906 return;
907 }
909 /**
910 * Check that type 't' is a valid instantiation of a generic class
911 * (see JLS 4.5)
912 *
913 * @param t class type to be checked
914 * @return true if 't' is well-formed
915 */
916 public boolean checkValidGenericType(Type t) {
917 return firstIncompatibleTypeArg(t) == null;
918 }
919 //WHERE
920 private Type firstIncompatibleTypeArg(Type type) {
921 List<Type> formals = type.tsym.type.allparams();
922 List<Type> actuals = type.allparams();
923 List<Type> args = type.getTypeArguments();
924 List<Type> forms = type.tsym.type.getTypeArguments();
925 ListBuffer<Type> bounds_buf = new ListBuffer<Type>();
927 // For matching pairs of actual argument types `a' and
928 // formal type parameters with declared bound `b' ...
929 while (args.nonEmpty() && forms.nonEmpty()) {
930 // exact type arguments needs to know their
931 // bounds (for upper and lower bound
932 // calculations). So we create new bounds where
933 // type-parameters are replaced with actuals argument types.
934 bounds_buf.append(types.subst(forms.head.getUpperBound(), formals, actuals));
935 args = args.tail;
936 forms = forms.tail;
937 }
939 args = type.getTypeArguments();
940 List<Type> tvars_cap = types.substBounds(formals,
941 formals,
942 types.capture(type).allparams());
943 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
944 // Let the actual arguments know their bound
945 args.head.withTypeVar((TypeVar)tvars_cap.head);
946 args = args.tail;
947 tvars_cap = tvars_cap.tail;
948 }
950 args = type.getTypeArguments();
951 List<Type> bounds = bounds_buf.toList();
953 while (args.nonEmpty() && bounds.nonEmpty()) {
954 Type actual = args.head;
955 if (!isTypeArgErroneous(actual) &&
956 !bounds.head.isErroneous() &&
957 !checkExtends(actual, bounds.head)) {
958 return args.head;
959 }
960 args = args.tail;
961 bounds = bounds.tail;
962 }
964 args = type.getTypeArguments();
965 bounds = bounds_buf.toList();
967 for (Type arg : types.capture(type).getTypeArguments()) {
968 if (arg.tag == TYPEVAR &&
969 arg.getUpperBound().isErroneous() &&
970 !bounds.head.isErroneous() &&
971 !isTypeArgErroneous(args.head)) {
972 return args.head;
973 }
974 bounds = bounds.tail;
975 args = args.tail;
976 }
978 return null;
979 }
980 //where
981 boolean isTypeArgErroneous(Type t) {
982 return isTypeArgErroneous.visit(t);
983 }
985 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() {
986 public Boolean visitType(Type t, Void s) {
987 return t.isErroneous();
988 }
989 @Override
990 public Boolean visitTypeVar(TypeVar t, Void s) {
991 return visit(t.getUpperBound());
992 }
993 @Override
994 public Boolean visitCapturedType(CapturedType t, Void s) {
995 return visit(t.getUpperBound()) ||
996 visit(t.getLowerBound());
997 }
998 @Override
999 public Boolean visitWildcardType(WildcardType t, Void s) {
1000 return visit(t.type);
1001 }
1002 };
1004 /** Check that given modifiers are legal for given symbol and
1005 * return modifiers together with any implicit modififiers for that symbol.
1006 * Warning: we can't use flags() here since this method
1007 * is called during class enter, when flags() would cause a premature
1008 * completion.
1009 * @param pos Position to be used for error reporting.
1010 * @param flags The set of modifiers given in a definition.
1011 * @param sym The defined symbol.
1012 */
1013 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
1014 long mask;
1015 long implicit = 0;
1016 switch (sym.kind) {
1017 case VAR:
1018 if (sym.owner.kind != TYP)
1019 mask = LocalVarFlags;
1020 else if ((sym.owner.flags_field & INTERFACE) != 0)
1021 mask = implicit = InterfaceVarFlags;
1022 else
1023 mask = VarFlags;
1024 break;
1025 case MTH:
1026 if (sym.name == names.init) {
1027 if ((sym.owner.flags_field & ENUM) != 0) {
1028 // enum constructors cannot be declared public or
1029 // protected and must be implicitly or explicitly
1030 // private
1031 implicit = PRIVATE;
1032 mask = PRIVATE;
1033 } else
1034 mask = ConstructorFlags;
1035 } else if ((sym.owner.flags_field & INTERFACE) != 0)
1036 mask = implicit = InterfaceMethodFlags;
1037 else {
1038 mask = MethodFlags;
1039 }
1040 // Imply STRICTFP if owner has STRICTFP set.
1041 if (((flags|implicit) & Flags.ABSTRACT) == 0)
1042 implicit |= sym.owner.flags_field & STRICTFP;
1043 break;
1044 case TYP:
1045 if (sym.isLocal()) {
1046 mask = LocalClassFlags;
1047 if (sym.name.isEmpty()) { // Anonymous class
1048 // Anonymous classes in static methods are themselves static;
1049 // that's why we admit STATIC here.
1050 mask |= STATIC;
1051 // JLS: Anonymous classes are final.
1052 implicit |= FINAL;
1053 }
1054 if ((sym.owner.flags_field & STATIC) == 0 &&
1055 (flags & ENUM) != 0)
1056 log.error(pos, "enums.must.be.static");
1057 } else if (sym.owner.kind == TYP) {
1058 mask = MemberClassFlags;
1059 if (sym.owner.owner.kind == PCK ||
1060 (sym.owner.flags_field & STATIC) != 0)
1061 mask |= STATIC;
1062 else if ((flags & ENUM) != 0)
1063 log.error(pos, "enums.must.be.static");
1064 // Nested interfaces and enums are always STATIC (Spec ???)
1065 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
1066 } else {
1067 mask = ClassFlags;
1068 }
1069 // Interfaces are always ABSTRACT
1070 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
1072 if ((flags & ENUM) != 0) {
1073 // enums can't be declared abstract or final
1074 mask &= ~(ABSTRACT | FINAL);
1075 implicit |= implicitEnumFinalFlag(tree);
1076 }
1077 // Imply STRICTFP if owner has STRICTFP set.
1078 implicit |= sym.owner.flags_field & STRICTFP;
1079 break;
1080 default:
1081 throw new AssertionError();
1082 }
1083 long illegal = flags & StandardFlags & ~mask;
1084 if (illegal != 0) {
1085 if ((illegal & INTERFACE) != 0) {
1086 log.error(pos, "intf.not.allowed.here");
1087 mask |= INTERFACE;
1088 }
1089 else {
1090 log.error(pos,
1091 "mod.not.allowed.here", asFlagSet(illegal));
1092 }
1093 }
1094 else if ((sym.kind == TYP ||
1095 // ISSUE: Disallowing abstract&private is no longer appropriate
1096 // in the presence of inner classes. Should it be deleted here?
1097 checkDisjoint(pos, flags,
1098 ABSTRACT,
1099 PRIVATE | STATIC))
1100 &&
1101 checkDisjoint(pos, flags,
1102 ABSTRACT | INTERFACE,
1103 FINAL | NATIVE | SYNCHRONIZED)
1104 &&
1105 checkDisjoint(pos, flags,
1106 PUBLIC,
1107 PRIVATE | PROTECTED)
1108 &&
1109 checkDisjoint(pos, flags,
1110 PRIVATE,
1111 PUBLIC | PROTECTED)
1112 &&
1113 checkDisjoint(pos, flags,
1114 FINAL,
1115 VOLATILE)
1116 &&
1117 (sym.kind == TYP ||
1118 checkDisjoint(pos, flags,
1119 ABSTRACT | NATIVE,
1120 STRICTFP))) {
1121 // skip
1122 }
1123 return flags & (mask | ~StandardFlags) | implicit;
1124 }
1127 /** Determine if this enum should be implicitly final.
1128 *
1129 * If the enum has no specialized enum contants, it is final.
1130 *
1131 * If the enum does have specialized enum contants, it is
1132 * <i>not</i> final.
1133 */
1134 private long implicitEnumFinalFlag(JCTree tree) {
1135 if (!tree.hasTag(CLASSDEF)) return 0;
1136 class SpecialTreeVisitor extends JCTree.Visitor {
1137 boolean specialized;
1138 SpecialTreeVisitor() {
1139 this.specialized = false;
1140 };
1142 @Override
1143 public void visitTree(JCTree tree) { /* no-op */ }
1145 @Override
1146 public void visitVarDef(JCVariableDecl tree) {
1147 if ((tree.mods.flags & ENUM) != 0) {
1148 if (tree.init instanceof JCNewClass &&
1149 ((JCNewClass) tree.init).def != null) {
1150 specialized = true;
1151 }
1152 }
1153 }
1154 }
1156 SpecialTreeVisitor sts = new SpecialTreeVisitor();
1157 JCClassDecl cdef = (JCClassDecl) tree;
1158 for (JCTree defs: cdef.defs) {
1159 defs.accept(sts);
1160 if (sts.specialized) return 0;
1161 }
1162 return FINAL;
1163 }
1165 /* *************************************************************************
1166 * Type Validation
1167 **************************************************************************/
1169 /** Validate a type expression. That is,
1170 * check that all type arguments of a parametric type are within
1171 * their bounds. This must be done in a second phase after type attributon
1172 * since a class might have a subclass as type parameter bound. E.g:
1173 *
1174 * class B<A extends C> { ... }
1175 * class C extends B<C> { ... }
1176 *
1177 * and we can't make sure that the bound is already attributed because
1178 * of possible cycles.
1179 *
1180 * Visitor method: Validate a type expression, if it is not null, catching
1181 * and reporting any completion failures.
1182 */
1183 void validate(JCTree tree, Env<AttrContext> env) {
1184 validate(tree, env, true);
1185 }
1186 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1187 new Validator(env).validateTree(tree, checkRaw, true);
1188 }
1190 /** Visitor method: Validate a list of type expressions.
1191 */
1192 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1193 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1194 validate(l.head, env);
1195 }
1197 /** A visitor class for type validation.
1198 */
1199 class Validator extends JCTree.Visitor {
1201 boolean isOuter;
1202 Env<AttrContext> env;
1204 Validator(Env<AttrContext> env) {
1205 this.env = env;
1206 }
1208 @Override
1209 public void visitTypeArray(JCArrayTypeTree tree) {
1210 tree.elemtype.accept(this);
1211 }
1213 @Override
1214 public void visitTypeApply(JCTypeApply tree) {
1215 if (tree.type.tag == CLASS) {
1216 List<JCExpression> args = tree.arguments;
1217 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1219 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1220 if (incompatibleArg != null) {
1221 for (JCTree arg : tree.arguments) {
1222 if (arg.type == incompatibleArg) {
1223 log.error(arg, "not.within.bounds", incompatibleArg, forms.head);
1224 }
1225 forms = forms.tail;
1226 }
1227 }
1229 forms = tree.type.tsym.type.getTypeArguments();
1231 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1233 // For matching pairs of actual argument types `a' and
1234 // formal type parameters with declared bound `b' ...
1235 while (args.nonEmpty() && forms.nonEmpty()) {
1236 validateTree(args.head,
1237 !(isOuter && is_java_lang_Class),
1238 false);
1239 args = args.tail;
1240 forms = forms.tail;
1241 }
1243 // Check that this type is either fully parameterized, or
1244 // not parameterized at all.
1245 if (tree.type.getEnclosingType().isRaw())
1246 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
1247 if (tree.clazz.hasTag(SELECT))
1248 visitSelectInternal((JCFieldAccess)tree.clazz);
1249 }
1250 }
1252 @Override
1253 public void visitTypeParameter(JCTypeParameter tree) {
1254 validateTrees(tree.bounds, true, isOuter);
1255 checkClassBounds(tree.pos(), tree.type);
1256 }
1258 @Override
1259 public void visitWildcard(JCWildcard tree) {
1260 if (tree.inner != null)
1261 validateTree(tree.inner, true, isOuter);
1262 }
1264 @Override
1265 public void visitSelect(JCFieldAccess tree) {
1266 if (tree.type.tag == CLASS) {
1267 visitSelectInternal(tree);
1269 // Check that this type is either fully parameterized, or
1270 // not parameterized at all.
1271 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1272 log.error(tree.pos(), "improperly.formed.type.param.missing");
1273 }
1274 }
1276 public void visitSelectInternal(JCFieldAccess tree) {
1277 if (tree.type.tsym.isStatic() &&
1278 tree.selected.type.isParameterized()) {
1279 // The enclosing type is not a class, so we are
1280 // looking at a static member type. However, the
1281 // qualifying expression is parameterized.
1282 log.error(tree.pos(), "cant.select.static.class.from.param.type");
1283 } else {
1284 // otherwise validate the rest of the expression
1285 tree.selected.accept(this);
1286 }
1287 }
1289 /** Default visitor method: do nothing.
1290 */
1291 @Override
1292 public void visitTree(JCTree tree) {
1293 }
1295 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1296 try {
1297 if (tree != null) {
1298 this.isOuter = isOuter;
1299 tree.accept(this);
1300 if (checkRaw)
1301 checkRaw(tree, env);
1302 }
1303 } catch (CompletionFailure ex) {
1304 completionError(tree.pos(), ex);
1305 }
1306 }
1308 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1309 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1310 validateTree(l.head, checkRaw, isOuter);
1311 }
1313 void checkRaw(JCTree tree, Env<AttrContext> env) {
1314 if (lint.isEnabled(LintCategory.RAW) &&
1315 tree.type.tag == CLASS &&
1316 !TreeInfo.isDiamond(tree) &&
1317 !withinAnonConstr(env) &&
1318 tree.type.isRaw()) {
1319 log.warning(LintCategory.RAW,
1320 tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
1321 }
1322 }
1324 boolean withinAnonConstr(Env<AttrContext> env) {
1325 return env.enclClass.name.isEmpty() &&
1326 env.enclMethod != null && env.enclMethod.name == names.init;
1327 }
1328 }
1330 /* *************************************************************************
1331 * Exception checking
1332 **************************************************************************/
1334 /* The following methods treat classes as sets that contain
1335 * the class itself and all their subclasses
1336 */
1338 /** Is given type a subtype of some of the types in given list?
1339 */
1340 boolean subset(Type t, List<Type> ts) {
1341 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1342 if (types.isSubtype(t, l.head)) return true;
1343 return false;
1344 }
1346 /** Is given type a subtype or supertype of
1347 * some of the types in given list?
1348 */
1349 boolean intersects(Type t, List<Type> ts) {
1350 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1351 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1352 return false;
1353 }
1355 /** Add type set to given type list, unless it is a subclass of some class
1356 * in the list.
1357 */
1358 List<Type> incl(Type t, List<Type> ts) {
1359 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1360 }
1362 /** Remove type set from type set list.
1363 */
1364 List<Type> excl(Type t, List<Type> ts) {
1365 if (ts.isEmpty()) {
1366 return ts;
1367 } else {
1368 List<Type> ts1 = excl(t, ts.tail);
1369 if (types.isSubtype(ts.head, t)) return ts1;
1370 else if (ts1 == ts.tail) return ts;
1371 else return ts1.prepend(ts.head);
1372 }
1373 }
1375 /** Form the union of two type set lists.
1376 */
1377 List<Type> union(List<Type> ts1, List<Type> ts2) {
1378 List<Type> ts = ts1;
1379 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1380 ts = incl(l.head, ts);
1381 return ts;
1382 }
1384 /** Form the difference of two type lists.
1385 */
1386 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1387 List<Type> ts = ts1;
1388 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1389 ts = excl(l.head, ts);
1390 return ts;
1391 }
1393 /** Form the intersection of two type lists.
1394 */
1395 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1396 List<Type> ts = List.nil();
1397 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1398 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1399 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1400 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1401 return ts;
1402 }
1404 /** Is exc an exception symbol that need not be declared?
1405 */
1406 boolean isUnchecked(ClassSymbol exc) {
1407 return
1408 exc.kind == ERR ||
1409 exc.isSubClass(syms.errorType.tsym, types) ||
1410 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1411 }
1413 /** Is exc an exception type that need not be declared?
1414 */
1415 boolean isUnchecked(Type exc) {
1416 return
1417 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
1418 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
1419 exc.tag == BOT;
1420 }
1422 /** Same, but handling completion failures.
1423 */
1424 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1425 try {
1426 return isUnchecked(exc);
1427 } catch (CompletionFailure ex) {
1428 completionError(pos, ex);
1429 return true;
1430 }
1431 }
1433 /** Is exc handled by given exception list?
1434 */
1435 boolean isHandled(Type exc, List<Type> handled) {
1436 return isUnchecked(exc) || subset(exc, handled);
1437 }
1439 /** Return all exceptions in thrown list that are not in handled list.
1440 * @param thrown The list of thrown exceptions.
1441 * @param handled The list of handled exceptions.
1442 */
1443 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1444 List<Type> unhandled = List.nil();
1445 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1446 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1447 return unhandled;
1448 }
1450 /* *************************************************************************
1451 * Overriding/Implementation checking
1452 **************************************************************************/
1454 /** The level of access protection given by a flag set,
1455 * where PRIVATE is highest and PUBLIC is lowest.
1456 */
1457 static int protection(long flags) {
1458 switch ((short)(flags & AccessFlags)) {
1459 case PRIVATE: return 3;
1460 case PROTECTED: return 1;
1461 default:
1462 case PUBLIC: return 0;
1463 case 0: return 2;
1464 }
1465 }
1467 /** A customized "cannot override" error message.
1468 * @param m The overriding method.
1469 * @param other The overridden method.
1470 * @return An internationalized string.
1471 */
1472 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1473 String key;
1474 if ((other.owner.flags() & INTERFACE) == 0)
1475 key = "cant.override";
1476 else if ((m.owner.flags() & INTERFACE) == 0)
1477 key = "cant.implement";
1478 else
1479 key = "clashes.with";
1480 return diags.fragment(key, m, m.location(), other, other.location());
1481 }
1483 /** A customized "override" warning message.
1484 * @param m The overriding method.
1485 * @param other The overridden method.
1486 * @return An internationalized string.
1487 */
1488 Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1489 String key;
1490 if ((other.owner.flags() & INTERFACE) == 0)
1491 key = "unchecked.override";
1492 else if ((m.owner.flags() & INTERFACE) == 0)
1493 key = "unchecked.implement";
1494 else
1495 key = "unchecked.clash.with";
1496 return diags.fragment(key, m, m.location(), other, other.location());
1497 }
1499 /** A customized "override" warning message.
1500 * @param m The overriding method.
1501 * @param other The overridden method.
1502 * @return An internationalized string.
1503 */
1504 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1505 String key;
1506 if ((other.owner.flags() & INTERFACE) == 0)
1507 key = "varargs.override";
1508 else if ((m.owner.flags() & INTERFACE) == 0)
1509 key = "varargs.implement";
1510 else
1511 key = "varargs.clash.with";
1512 return diags.fragment(key, m, m.location(), other, other.location());
1513 }
1515 /** Check that this method conforms with overridden method 'other'.
1516 * where `origin' is the class where checking started.
1517 * Complications:
1518 * (1) Do not check overriding of synthetic methods
1519 * (reason: they might be final).
1520 * todo: check whether this is still necessary.
1521 * (2) Admit the case where an interface proxy throws fewer exceptions
1522 * than the method it implements. Augment the proxy methods with the
1523 * undeclared exceptions in this case.
1524 * (3) When generics are enabled, admit the case where an interface proxy
1525 * has a result type
1526 * extended by the result type of the method it implements.
1527 * Change the proxies result type to the smaller type in this case.
1528 *
1529 * @param tree The tree from which positions
1530 * are extracted for errors.
1531 * @param m The overriding method.
1532 * @param other The overridden method.
1533 * @param origin The class of which the overriding method
1534 * is a member.
1535 */
1536 void checkOverride(JCTree tree,
1537 MethodSymbol m,
1538 MethodSymbol other,
1539 ClassSymbol origin) {
1540 // Don't check overriding of synthetic methods or by bridge methods.
1541 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1542 return;
1543 }
1545 // Error if static method overrides instance method (JLS 8.4.6.2).
1546 if ((m.flags() & STATIC) != 0 &&
1547 (other.flags() & STATIC) == 0) {
1548 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1549 cannotOverride(m, other));
1550 return;
1551 }
1553 // Error if instance method overrides static or final
1554 // method (JLS 8.4.6.1).
1555 if ((other.flags() & FINAL) != 0 ||
1556 (m.flags() & STATIC) == 0 &&
1557 (other.flags() & STATIC) != 0) {
1558 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1559 cannotOverride(m, other),
1560 asFlagSet(other.flags() & (FINAL | STATIC)));
1561 return;
1562 }
1564 if ((m.owner.flags() & ANNOTATION) != 0) {
1565 // handled in validateAnnotationMethod
1566 return;
1567 }
1569 // Error if overriding method has weaker access (JLS 8.4.6.3).
1570 if ((origin.flags() & INTERFACE) == 0 &&
1571 protection(m.flags()) > protection(other.flags())) {
1572 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1573 cannotOverride(m, other),
1574 other.flags() == 0 ?
1575 Flag.PACKAGE :
1576 asFlagSet(other.flags() & AccessFlags));
1577 return;
1578 }
1580 Type mt = types.memberType(origin.type, m);
1581 Type ot = types.memberType(origin.type, other);
1582 // Error if overriding result type is different
1583 // (or, in the case of generics mode, not a subtype) of
1584 // overridden result type. We have to rename any type parameters
1585 // before comparing types.
1586 List<Type> mtvars = mt.getTypeArguments();
1587 List<Type> otvars = ot.getTypeArguments();
1588 Type mtres = mt.getReturnType();
1589 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1591 overrideWarner.clear();
1592 boolean resultTypesOK =
1593 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1594 if (!resultTypesOK) {
1595 if (!allowCovariantReturns &&
1596 m.owner != origin &&
1597 m.owner.isSubClass(other.owner, types)) {
1598 // allow limited interoperability with covariant returns
1599 } else {
1600 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1601 "override.incompatible.ret",
1602 cannotOverride(m, other),
1603 mtres, otres);
1604 return;
1605 }
1606 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1607 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1608 "override.unchecked.ret",
1609 uncheckedOverrides(m, other),
1610 mtres, otres);
1611 }
1613 // Error if overriding method throws an exception not reported
1614 // by overridden method.
1615 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1616 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1617 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1618 if (unhandledErased.nonEmpty()) {
1619 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1620 "override.meth.doesnt.throw",
1621 cannotOverride(m, other),
1622 unhandledUnerased.head);
1623 return;
1624 }
1625 else if (unhandledUnerased.nonEmpty()) {
1626 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1627 "override.unchecked.thrown",
1628 cannotOverride(m, other),
1629 unhandledUnerased.head);
1630 return;
1631 }
1633 // Optional warning if varargs don't agree
1634 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1635 && lint.isEnabled(LintCategory.OVERRIDES)) {
1636 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1637 ((m.flags() & Flags.VARARGS) != 0)
1638 ? "override.varargs.missing"
1639 : "override.varargs.extra",
1640 varargsOverrides(m, other));
1641 }
1643 // Warn if instance method overrides bridge method (compiler spec ??)
1644 if ((other.flags() & BRIDGE) != 0) {
1645 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1646 uncheckedOverrides(m, other));
1647 }
1649 // Warn if a deprecated method overridden by a non-deprecated one.
1650 if (!isDeprecatedOverrideIgnorable(other, origin)) {
1651 checkDeprecated(TreeInfo.diagnosticPositionFor(m, tree), m, other);
1652 }
1653 }
1654 // where
1655 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1656 // If the method, m, is defined in an interface, then ignore the issue if the method
1657 // is only inherited via a supertype and also implemented in the supertype,
1658 // because in that case, we will rediscover the issue when examining the method
1659 // in the supertype.
1660 // If the method, m, is not defined in an interface, then the only time we need to
1661 // address the issue is when the method is the supertype implemementation: any other
1662 // case, we will have dealt with when examining the supertype classes
1663 ClassSymbol mc = m.enclClass();
1664 Type st = types.supertype(origin.type);
1665 if (st.tag != CLASS)
1666 return true;
1667 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1669 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1670 List<Type> intfs = types.interfaces(origin.type);
1671 return (intfs.contains(mc.type) ? false : (stimpl != null));
1672 }
1673 else
1674 return (stimpl != m);
1675 }
1678 // used to check if there were any unchecked conversions
1679 Warner overrideWarner = new Warner();
1681 /** Check that a class does not inherit two concrete methods
1682 * with the same signature.
1683 * @param pos Position to be used for error reporting.
1684 * @param site The class type to be checked.
1685 */
1686 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1687 Type sup = types.supertype(site);
1688 if (sup.tag != CLASS) return;
1690 for (Type t1 = sup;
1691 t1.tsym.type.isParameterized();
1692 t1 = types.supertype(t1)) {
1693 for (Scope.Entry e1 = t1.tsym.members().elems;
1694 e1 != null;
1695 e1 = e1.sibling) {
1696 Symbol s1 = e1.sym;
1697 if (s1.kind != MTH ||
1698 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1699 !s1.isInheritedIn(site.tsym, types) ||
1700 ((MethodSymbol)s1).implementation(site.tsym,
1701 types,
1702 true) != s1)
1703 continue;
1704 Type st1 = types.memberType(t1, s1);
1705 int s1ArgsLength = st1.getParameterTypes().length();
1706 if (st1 == s1.type) continue;
1708 for (Type t2 = sup;
1709 t2.tag == CLASS;
1710 t2 = types.supertype(t2)) {
1711 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1712 e2.scope != null;
1713 e2 = e2.next()) {
1714 Symbol s2 = e2.sym;
1715 if (s2 == s1 ||
1716 s2.kind != MTH ||
1717 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1718 s2.type.getParameterTypes().length() != s1ArgsLength ||
1719 !s2.isInheritedIn(site.tsym, types) ||
1720 ((MethodSymbol)s2).implementation(site.tsym,
1721 types,
1722 true) != s2)
1723 continue;
1724 Type st2 = types.memberType(t2, s2);
1725 if (types.overrideEquivalent(st1, st2))
1726 log.error(pos, "concrete.inheritance.conflict",
1727 s1, t1, s2, t2, sup);
1728 }
1729 }
1730 }
1731 }
1732 }
1734 /** Check that classes (or interfaces) do not each define an abstract
1735 * method with same name and arguments but incompatible return types.
1736 * @param pos Position to be used for error reporting.
1737 * @param t1 The first argument type.
1738 * @param t2 The second argument type.
1739 */
1740 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1741 Type t1,
1742 Type t2) {
1743 return checkCompatibleAbstracts(pos, t1, t2,
1744 types.makeCompoundType(t1, t2));
1745 }
1747 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1748 Type t1,
1749 Type t2,
1750 Type site) {
1751 return firstIncompatibility(pos, t1, t2, site) == null;
1752 }
1754 /** Return the first method which is defined with same args
1755 * but different return types in two given interfaces, or null if none
1756 * exists.
1757 * @param t1 The first type.
1758 * @param t2 The second type.
1759 * @param site The most derived type.
1760 * @returns symbol from t2 that conflicts with one in t1.
1761 */
1762 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1763 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1764 closure(t1, interfaces1);
1765 Map<TypeSymbol,Type> interfaces2;
1766 if (t1 == t2)
1767 interfaces2 = interfaces1;
1768 else
1769 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1771 for (Type t3 : interfaces1.values()) {
1772 for (Type t4 : interfaces2.values()) {
1773 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
1774 if (s != null) return s;
1775 }
1776 }
1777 return null;
1778 }
1780 /** Compute all the supertypes of t, indexed by type symbol. */
1781 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1782 if (t.tag != CLASS) return;
1783 if (typeMap.put(t.tsym, t) == null) {
1784 closure(types.supertype(t), typeMap);
1785 for (Type i : types.interfaces(t))
1786 closure(i, typeMap);
1787 }
1788 }
1790 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1791 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1792 if (t.tag != CLASS) return;
1793 if (typesSkip.get(t.tsym) != null) return;
1794 if (typeMap.put(t.tsym, t) == null) {
1795 closure(types.supertype(t), typesSkip, typeMap);
1796 for (Type i : types.interfaces(t))
1797 closure(i, typesSkip, typeMap);
1798 }
1799 }
1801 /** Return the first method in t2 that conflicts with a method from t1. */
1802 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1803 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1804 Symbol s1 = e1.sym;
1805 Type st1 = null;
1806 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1807 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1808 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1809 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1810 Symbol s2 = e2.sym;
1811 if (s1 == s2) continue;
1812 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1813 if (st1 == null) st1 = types.memberType(t1, s1);
1814 Type st2 = types.memberType(t2, s2);
1815 if (types.overrideEquivalent(st1, st2)) {
1816 List<Type> tvars1 = st1.getTypeArguments();
1817 List<Type> tvars2 = st2.getTypeArguments();
1818 Type rt1 = st1.getReturnType();
1819 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1820 boolean compat =
1821 types.isSameType(rt1, rt2) ||
1822 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1823 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1824 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1825 checkCommonOverriderIn(s1,s2,site);
1826 if (!compat) {
1827 log.error(pos, "types.incompatible.diff.ret",
1828 t1, t2, s2.name +
1829 "(" + types.memberType(t2, s2).getParameterTypes() + ")");
1830 return s2;
1831 }
1832 } else if (checkNameClash((ClassSymbol)site.tsym, s1, s2) &&
1833 !checkCommonOverriderIn(s1, s2, site)) {
1834 log.error(pos,
1835 "name.clash.same.erasure.no.override",
1836 s1, s1.location(),
1837 s2, s2.location());
1838 return s2;
1839 }
1840 }
1841 }
1842 return null;
1843 }
1844 //WHERE
1845 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1846 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1847 Type st1 = types.memberType(site, s1);
1848 Type st2 = types.memberType(site, s2);
1849 closure(site, supertypes);
1850 for (Type t : supertypes.values()) {
1851 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1852 Symbol s3 = e.sym;
1853 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1854 Type st3 = types.memberType(site,s3);
1855 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1856 if (s3.owner == site.tsym) {
1857 return true;
1858 }
1859 List<Type> tvars1 = st1.getTypeArguments();
1860 List<Type> tvars2 = st2.getTypeArguments();
1861 List<Type> tvars3 = st3.getTypeArguments();
1862 Type rt1 = st1.getReturnType();
1863 Type rt2 = st2.getReturnType();
1864 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1865 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1866 boolean compat =
1867 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1868 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1869 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1870 if (compat)
1871 return true;
1872 }
1873 }
1874 }
1875 return false;
1876 }
1878 /** Check that a given method conforms with any method it overrides.
1879 * @param tree The tree from which positions are extracted
1880 * for errors.
1881 * @param m The overriding method.
1882 */
1883 void checkOverride(JCTree tree, MethodSymbol m) {
1884 ClassSymbol origin = (ClassSymbol)m.owner;
1885 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1886 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1887 log.error(tree.pos(), "enum.no.finalize");
1888 return;
1889 }
1890 for (Type t = origin.type; t.tag == CLASS;
1891 t = types.supertype(t)) {
1892 if (t != origin.type) {
1893 checkOverride(tree, t, origin, m);
1894 }
1895 for (Type t2 : types.interfaces(t)) {
1896 checkOverride(tree, t2, origin, m);
1897 }
1898 }
1899 }
1901 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
1902 TypeSymbol c = site.tsym;
1903 Scope.Entry e = c.members().lookup(m.name);
1904 while (e.scope != null) {
1905 if (m.overrides(e.sym, origin, types, false)) {
1906 if ((e.sym.flags() & ABSTRACT) == 0) {
1907 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1908 }
1909 }
1910 e = e.next();
1911 }
1912 }
1914 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
1915 ClashFilter cf = new ClashFilter(origin.type);
1916 return (cf.accepts(s1) &&
1917 cf.accepts(s2) &&
1918 types.hasSameArgs(s1.erasure(types), s2.erasure(types)));
1919 }
1922 /** Check that all abstract members of given class have definitions.
1923 * @param pos Position to be used for error reporting.
1924 * @param c The class.
1925 */
1926 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1927 try {
1928 MethodSymbol undef = firstUndef(c, c);
1929 if (undef != null) {
1930 if ((c.flags() & ENUM) != 0 &&
1931 types.supertype(c.type).tsym == syms.enumSym &&
1932 (c.flags() & FINAL) == 0) {
1933 // add the ABSTRACT flag to an enum
1934 c.flags_field |= ABSTRACT;
1935 } else {
1936 MethodSymbol undef1 =
1937 new MethodSymbol(undef.flags(), undef.name,
1938 types.memberType(c.type, undef), undef.owner);
1939 log.error(pos, "does.not.override.abstract",
1940 c, undef1, undef1.location());
1941 }
1942 }
1943 } catch (CompletionFailure ex) {
1944 completionError(pos, ex);
1945 }
1946 }
1947 //where
1948 /** Return first abstract member of class `c' that is not defined
1949 * in `impl', null if there is none.
1950 */
1951 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1952 MethodSymbol undef = null;
1953 // Do not bother to search in classes that are not abstract,
1954 // since they cannot have abstract members.
1955 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1956 Scope s = c.members();
1957 for (Scope.Entry e = s.elems;
1958 undef == null && e != null;
1959 e = e.sibling) {
1960 if (e.sym.kind == MTH &&
1961 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1962 MethodSymbol absmeth = (MethodSymbol)e.sym;
1963 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1964 if (implmeth == null || implmeth == absmeth)
1965 undef = absmeth;
1966 }
1967 }
1968 if (undef == null) {
1969 Type st = types.supertype(c.type);
1970 if (st.tag == CLASS)
1971 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1972 }
1973 for (List<Type> l = types.interfaces(c.type);
1974 undef == null && l.nonEmpty();
1975 l = l.tail) {
1976 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1977 }
1978 }
1979 return undef;
1980 }
1982 void checkNonCyclicDecl(JCClassDecl tree) {
1983 CycleChecker cc = new CycleChecker();
1984 cc.scan(tree);
1985 if (!cc.errorFound && !cc.partialCheck) {
1986 tree.sym.flags_field |= ACYCLIC;
1987 }
1988 }
1990 class CycleChecker extends TreeScanner {
1992 List<Symbol> seenClasses = List.nil();
1993 boolean errorFound = false;
1994 boolean partialCheck = false;
1996 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
1997 if (sym != null && sym.kind == TYP) {
1998 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
1999 if (classEnv != null) {
2000 DiagnosticSource prevSource = log.currentSource();
2001 try {
2002 log.useSource(classEnv.toplevel.sourcefile);
2003 scan(classEnv.tree);
2004 }
2005 finally {
2006 log.useSource(prevSource.getFile());
2007 }
2008 } else if (sym.kind == TYP) {
2009 checkClass(pos, sym, List.<JCTree>nil());
2010 }
2011 } else {
2012 //not completed yet
2013 partialCheck = true;
2014 }
2015 }
2017 @Override
2018 public void visitSelect(JCFieldAccess tree) {
2019 super.visitSelect(tree);
2020 checkSymbol(tree.pos(), tree.sym);
2021 }
2023 @Override
2024 public void visitIdent(JCIdent tree) {
2025 checkSymbol(tree.pos(), tree.sym);
2026 }
2028 @Override
2029 public void visitTypeApply(JCTypeApply tree) {
2030 scan(tree.clazz);
2031 }
2033 @Override
2034 public void visitTypeArray(JCArrayTypeTree tree) {
2035 scan(tree.elemtype);
2036 }
2038 @Override
2039 public void visitClassDef(JCClassDecl tree) {
2040 List<JCTree> supertypes = List.nil();
2041 if (tree.getExtendsClause() != null) {
2042 supertypes = supertypes.prepend(tree.getExtendsClause());
2043 }
2044 if (tree.getImplementsClause() != null) {
2045 for (JCTree intf : tree.getImplementsClause()) {
2046 supertypes = supertypes.prepend(intf);
2047 }
2048 }
2049 checkClass(tree.pos(), tree.sym, supertypes);
2050 }
2052 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
2053 if ((c.flags_field & ACYCLIC) != 0)
2054 return;
2055 if (seenClasses.contains(c)) {
2056 errorFound = true;
2057 noteCyclic(pos, (ClassSymbol)c);
2058 } else if (!c.type.isErroneous()) {
2059 try {
2060 seenClasses = seenClasses.prepend(c);
2061 if (c.type.tag == CLASS) {
2062 if (supertypes.nonEmpty()) {
2063 scan(supertypes);
2064 }
2065 else {
2066 ClassType ct = (ClassType)c.type;
2067 if (ct.supertype_field == null ||
2068 ct.interfaces_field == null) {
2069 //not completed yet
2070 partialCheck = true;
2071 return;
2072 }
2073 checkSymbol(pos, ct.supertype_field.tsym);
2074 for (Type intf : ct.interfaces_field) {
2075 checkSymbol(pos, intf.tsym);
2076 }
2077 }
2078 if (c.owner.kind == TYP) {
2079 checkSymbol(pos, c.owner);
2080 }
2081 }
2082 } finally {
2083 seenClasses = seenClasses.tail;
2084 }
2085 }
2086 }
2087 }
2089 /** Check for cyclic references. Issue an error if the
2090 * symbol of the type referred to has a LOCKED flag set.
2091 *
2092 * @param pos Position to be used for error reporting.
2093 * @param t The type referred to.
2094 */
2095 void checkNonCyclic(DiagnosticPosition pos, Type t) {
2096 checkNonCyclicInternal(pos, t);
2097 }
2100 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
2101 checkNonCyclic1(pos, t, List.<TypeVar>nil());
2102 }
2104 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
2105 final TypeVar tv;
2106 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
2107 return;
2108 if (seen.contains(t)) {
2109 tv = (TypeVar)t;
2110 tv.bound = types.createErrorType(t);
2111 log.error(pos, "cyclic.inheritance", t);
2112 } else if (t.tag == TYPEVAR) {
2113 tv = (TypeVar)t;
2114 seen = seen.prepend(tv);
2115 for (Type b : types.getBounds(tv))
2116 checkNonCyclic1(pos, b, seen);
2117 }
2118 }
2120 /** Check for cyclic references. Issue an error if the
2121 * symbol of the type referred to has a LOCKED flag set.
2122 *
2123 * @param pos Position to be used for error reporting.
2124 * @param t The type referred to.
2125 * @returns True if the check completed on all attributed classes
2126 */
2127 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
2128 boolean complete = true; // was the check complete?
2129 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
2130 Symbol c = t.tsym;
2131 if ((c.flags_field & ACYCLIC) != 0) return true;
2133 if ((c.flags_field & LOCKED) != 0) {
2134 noteCyclic(pos, (ClassSymbol)c);
2135 } else if (!c.type.isErroneous()) {
2136 try {
2137 c.flags_field |= LOCKED;
2138 if (c.type.tag == CLASS) {
2139 ClassType clazz = (ClassType)c.type;
2140 if (clazz.interfaces_field != null)
2141 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
2142 complete &= checkNonCyclicInternal(pos, l.head);
2143 if (clazz.supertype_field != null) {
2144 Type st = clazz.supertype_field;
2145 if (st != null && st.tag == CLASS)
2146 complete &= checkNonCyclicInternal(pos, st);
2147 }
2148 if (c.owner.kind == TYP)
2149 complete &= checkNonCyclicInternal(pos, c.owner.type);
2150 }
2151 } finally {
2152 c.flags_field &= ~LOCKED;
2153 }
2154 }
2155 if (complete)
2156 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
2157 if (complete) c.flags_field |= ACYCLIC;
2158 return complete;
2159 }
2161 /** Note that we found an inheritance cycle. */
2162 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
2163 log.error(pos, "cyclic.inheritance", c);
2164 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
2165 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
2166 Type st = types.supertype(c.type);
2167 if (st.tag == CLASS)
2168 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2169 c.type = types.createErrorType(c, c.type);
2170 c.flags_field |= ACYCLIC;
2171 }
2173 /** Check that all methods which implement some
2174 * method conform to the method they implement.
2175 * @param tree The class definition whose members are checked.
2176 */
2177 void checkImplementations(JCClassDecl tree) {
2178 checkImplementations(tree, tree.sym);
2179 }
2180 //where
2181 /** Check that all methods which implement some
2182 * method in `ic' conform to the method they implement.
2183 */
2184 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
2185 ClassSymbol origin = tree.sym;
2186 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2187 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2188 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
2189 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
2190 if (e.sym.kind == MTH &&
2191 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2192 MethodSymbol absmeth = (MethodSymbol)e.sym;
2193 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2194 if (implmeth != null && implmeth != absmeth &&
2195 (implmeth.owner.flags() & INTERFACE) ==
2196 (origin.flags() & INTERFACE)) {
2197 // don't check if implmeth is in a class, yet
2198 // origin is an interface. This case arises only
2199 // if implmeth is declared in Object. The reason is
2200 // that interfaces really don't inherit from
2201 // Object it's just that the compiler represents
2202 // things that way.
2203 checkOverride(tree, implmeth, absmeth, origin);
2204 }
2205 }
2206 }
2207 }
2208 }
2209 }
2211 /** Check that all abstract methods implemented by a class are
2212 * mutually compatible.
2213 * @param pos Position to be used for error reporting.
2214 * @param c The class whose interfaces are checked.
2215 */
2216 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2217 List<Type> supertypes = types.interfaces(c);
2218 Type supertype = types.supertype(c);
2219 if (supertype.tag == CLASS &&
2220 (supertype.tsym.flags() & ABSTRACT) != 0)
2221 supertypes = supertypes.prepend(supertype);
2222 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2223 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
2224 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2225 return;
2226 for (List<Type> m = supertypes; m != l; m = m.tail)
2227 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2228 return;
2229 }
2230 checkCompatibleConcretes(pos, c);
2231 }
2233 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
2234 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
2235 for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
2236 // VM allows methods and variables with differing types
2237 if (sym.kind == e.sym.kind &&
2238 types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
2239 sym != e.sym &&
2240 (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
2241 (sym.flags() & IPROXY) == 0 && (e.sym.flags() & IPROXY) == 0 &&
2242 (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
2243 syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
2244 return;
2245 }
2246 }
2247 }
2248 }
2250 /** Check that all non-override equivalent methods accessible from 'site'
2251 * are mutually compatible (JLS 8.4.8/9.4.1).
2252 *
2253 * @param pos Position to be used for error reporting.
2254 * @param site The class whose methods are checked.
2255 * @param sym The method symbol to be checked.
2256 */
2257 void checkOverrideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2258 ClashFilter cf = new ClashFilter(site);
2259 //for each method m1 that is overridden (directly or indirectly)
2260 //by method 'sym' in 'site'...
2261 for (Symbol m1 : types.membersClosure(site, false).getElementsByName(sym.name, cf)) {
2262 if (!sym.overrides(m1, site.tsym, types, false)) continue;
2263 //...check each method m2 that is a member of 'site'
2264 for (Symbol m2 : types.membersClosure(site, false).getElementsByName(sym.name, cf)) {
2265 if (m2 == m1) continue;
2266 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2267 //a member of 'site') and (ii) m1 has the same erasure as m2, issue an error
2268 if (!types.isSubSignature(sym.type, types.memberType(site, m2), false) &&
2269 types.hasSameArgs(m2.erasure(types), m1.erasure(types))) {
2270 sym.flags_field |= CLASH;
2271 String key = m1 == sym ?
2272 "name.clash.same.erasure.no.override" :
2273 "name.clash.same.erasure.no.override.1";
2274 log.error(pos,
2275 key,
2276 sym, sym.location(),
2277 m2, m2.location(),
2278 m1, m1.location());
2279 return;
2280 }
2281 }
2282 }
2283 }
2287 /** Check that all static methods accessible from 'site' are
2288 * mutually compatible (JLS 8.4.8).
2289 *
2290 * @param pos Position to be used for error reporting.
2291 * @param site The class whose methods are checked.
2292 * @param sym The method symbol to be checked.
2293 */
2294 void checkHideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2295 ClashFilter cf = new ClashFilter(site);
2296 //for each method m1 that is a member of 'site'...
2297 for (Symbol s : types.membersClosure(site, true).getElementsByName(sym.name, cf)) {
2298 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2299 //a member of 'site') and (ii) 'sym' has the same erasure as m1, issue an error
2300 if (!types.isSubSignature(sym.type, types.memberType(site, s), false) &&
2301 types.hasSameArgs(s.erasure(types), sym.erasure(types))) {
2302 log.error(pos,
2303 "name.clash.same.erasure.no.hide",
2304 sym, sym.location(),
2305 s, s.location());
2306 return;
2307 }
2308 }
2309 }
2311 //where
2312 private class ClashFilter implements Filter<Symbol> {
2314 Type site;
2316 ClashFilter(Type site) {
2317 this.site = site;
2318 }
2320 boolean shouldSkip(Symbol s) {
2321 return (s.flags() & CLASH) != 0 &&
2322 s.owner == site.tsym;
2323 }
2325 public boolean accepts(Symbol s) {
2326 return s.kind == MTH &&
2327 (s.flags() & SYNTHETIC) == 0 &&
2328 !shouldSkip(s) &&
2329 s.isInheritedIn(site.tsym, types) &&
2330 !s.isConstructor();
2331 }
2332 }
2334 /** Report a conflict between a user symbol and a synthetic symbol.
2335 */
2336 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
2337 if (!sym.type.isErroneous()) {
2338 if (warnOnSyntheticConflicts) {
2339 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
2340 }
2341 else {
2342 log.error(pos, "synthetic.name.conflict", sym, sym.location());
2343 }
2344 }
2345 }
2347 /** Check that class c does not implement directly or indirectly
2348 * the same parameterized interface with two different argument lists.
2349 * @param pos Position to be used for error reporting.
2350 * @param type The type whose interfaces are checked.
2351 */
2352 void checkClassBounds(DiagnosticPosition pos, Type type) {
2353 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
2354 }
2355 //where
2356 /** Enter all interfaces of type `type' into the hash table `seensofar'
2357 * with their class symbol as key and their type as value. Make
2358 * sure no class is entered with two different types.
2359 */
2360 void checkClassBounds(DiagnosticPosition pos,
2361 Map<TypeSymbol,Type> seensofar,
2362 Type type) {
2363 if (type.isErroneous()) return;
2364 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
2365 Type it = l.head;
2366 Type oldit = seensofar.put(it.tsym, it);
2367 if (oldit != null) {
2368 List<Type> oldparams = oldit.allparams();
2369 List<Type> newparams = it.allparams();
2370 if (!types.containsTypeEquivalent(oldparams, newparams))
2371 log.error(pos, "cant.inherit.diff.arg",
2372 it.tsym, Type.toString(oldparams),
2373 Type.toString(newparams));
2374 }
2375 checkClassBounds(pos, seensofar, it);
2376 }
2377 Type st = types.supertype(type);
2378 if (st != null) checkClassBounds(pos, seensofar, st);
2379 }
2381 /** Enter interface into into set.
2382 * If it existed already, issue a "repeated interface" error.
2383 */
2384 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
2385 if (its.contains(it))
2386 log.error(pos, "repeated.interface");
2387 else {
2388 its.add(it);
2389 }
2390 }
2392 /* *************************************************************************
2393 * Check annotations
2394 **************************************************************************/
2396 /**
2397 * Recursively validate annotations values
2398 */
2399 void validateAnnotationTree(JCTree tree) {
2400 class AnnotationValidator extends TreeScanner {
2401 @Override
2402 public void visitAnnotation(JCAnnotation tree) {
2403 if (!tree.type.isErroneous()) {
2404 super.visitAnnotation(tree);
2405 validateAnnotation(tree);
2406 }
2407 }
2408 }
2409 tree.accept(new AnnotationValidator());
2410 }
2412 /**
2413 * {@literal
2414 * Annotation types are restricted to primitives, String, an
2415 * enum, an annotation, Class, Class<?>, Class<? extends
2416 * Anything>, arrays of the preceding.
2417 * }
2418 */
2419 void validateAnnotationType(JCTree restype) {
2420 // restype may be null if an error occurred, so don't bother validating it
2421 if (restype != null) {
2422 validateAnnotationType(restype.pos(), restype.type);
2423 }
2424 }
2426 void validateAnnotationType(DiagnosticPosition pos, Type type) {
2427 if (type.isPrimitive()) return;
2428 if (types.isSameType(type, syms.stringType)) return;
2429 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
2430 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
2431 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
2432 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
2433 validateAnnotationType(pos, types.elemtype(type));
2434 return;
2435 }
2436 log.error(pos, "invalid.annotation.member.type");
2437 }
2439 /**
2440 * "It is also a compile-time error if any method declared in an
2441 * annotation type has a signature that is override-equivalent to
2442 * that of any public or protected method declared in class Object
2443 * or in the interface annotation.Annotation."
2444 *
2445 * @jls 9.6 Annotation Types
2446 */
2447 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
2448 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
2449 Scope s = sup.tsym.members();
2450 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
2451 if (e.sym.kind == MTH &&
2452 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
2453 types.overrideEquivalent(m.type, e.sym.type))
2454 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
2455 }
2456 }
2457 }
2459 /** Check the annotations of a symbol.
2460 */
2461 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
2462 for (JCAnnotation a : annotations)
2463 validateAnnotation(a, s);
2464 }
2466 /** Check an annotation of a symbol.
2467 */
2468 private void validateAnnotation(JCAnnotation a, Symbol s) {
2469 validateAnnotationTree(a);
2471 if (!annotationApplicable(a, s))
2472 log.error(a.pos(), "annotation.type.not.applicable");
2474 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2475 if (!isOverrider(s))
2476 log.error(a.pos(), "method.does.not.override.superclass");
2477 }
2478 }
2480 /**
2481 * Validate the proposed container 'containedBy' on the
2482 * annotation type symbol 's'. Report errors at position
2483 * 'pos'.
2484 *
2485 * @param s The (annotation)type declaration annotated with a @ContainedBy
2486 * @param containerAnno the @ContainedBy on 's'
2487 * @param pos where to report errors
2488 */
2489 public void validateContainedBy(TypeSymbol s, Attribute.Compound containedBy, DiagnosticPosition pos) {
2490 Assert.check(types.isSameType(containedBy.type, syms.containedByType));
2492 Type t = null;
2493 List<Pair<MethodSymbol,Attribute>> l = containedBy.values;
2494 if (!l.isEmpty()) {
2495 Assert.check(l.head.fst.name == names.value);
2496 t = ((Attribute.Class)l.head.snd).getValue();
2497 }
2499 if (t == null) {
2500 log.error(pos, "invalid.container.wrong.containedby", s, containedBy);
2501 return;
2502 }
2504 validateHasContainerFor(t.tsym, s, pos);
2505 validateRetention(t.tsym, s, pos);
2506 validateDocumented(t.tsym, s, pos);
2507 validateInherited(t.tsym, s, pos);
2508 validateTarget(t.tsym, s, pos);
2509 validateDefault(t.tsym, s, pos);
2510 }
2512 /**
2513 * Validate the proposed container 'containerFor' on the
2514 * annotation type symbol 's'. Report errors at position
2515 * 'pos'.
2516 *
2517 * @param s The (annotation)type declaration annotated with a @ContainerFor
2518 * @param containerFor the @ContainedFor on 's'
2519 * @param pos where to report errors
2520 */
2521 public void validateContainerFor(TypeSymbol s, Attribute.Compound containerFor, DiagnosticPosition pos) {
2522 Assert.check(types.isSameType(containerFor.type, syms.containerForType));
2524 Type t = null;
2525 List<Pair<MethodSymbol,Attribute>> l = containerFor.values;
2526 if (!l.isEmpty()) {
2527 Assert.check(l.head.fst.name == names.value);
2528 t = ((Attribute.Class)l.head.snd).getValue();
2529 }
2531 if (t == null) {
2532 log.error(pos, "invalid.container.wrong.containerfor", s, containerFor);
2533 return;
2534 }
2536 validateHasContainedBy(t.tsym, s, pos);
2537 }
2539 private void validateHasContainedBy(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
2540 Attribute.Compound containedBy = container.attribute(syms.containedByType.tsym);
2542 if (containedBy == null) {
2543 log.error(pos, "invalid.container.no.containedby", container, syms.containedByType.tsym);
2544 return;
2545 }
2547 Type t = null;
2548 List<Pair<MethodSymbol,Attribute>> l = containedBy.values;
2549 if (!l.isEmpty()) {
2550 Assert.check(l.head.fst.name == names.value);
2551 t = ((Attribute.Class)l.head.snd).getValue();
2552 }
2554 if (t == null) {
2555 log.error(pos, "invalid.container.wrong.containedby", container, contained);
2556 return;
2557 }
2559 if (!types.isSameType(t, contained.type))
2560 log.error(pos, "invalid.container.wrong.containedby", t.tsym, contained);
2561 }
2563 private void validateHasContainerFor(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
2564 Attribute.Compound containerFor = container.attribute(syms.containerForType.tsym);
2566 if (containerFor == null) {
2567 log.error(pos, "invalid.container.no.containerfor", container, syms.containerForType.tsym);
2568 return;
2569 }
2571 Type t = null;
2572 List<Pair<MethodSymbol,Attribute>> l = containerFor.values;
2573 if (!l.isEmpty()) {
2574 Assert.check(l.head.fst.name == names.value);
2575 t = ((Attribute.Class)l.head.snd).getValue();
2576 }
2578 if (t == null) {
2579 log.error(pos, "invalid.container.wrong.containerfor", container, contained);
2580 return;
2581 }
2583 if (!types.isSameType(t, contained.type))
2584 log.error(pos, "invalid.container.wrong.containerfor", t.tsym, contained);
2585 }
2587 private void validateRetention(Symbol container, Symbol contained, DiagnosticPosition pos) {
2588 Attribute.RetentionPolicy containerRetention = types.getRetention(container);
2589 Attribute.RetentionPolicy containedRetention = types.getRetention(contained);
2591 boolean error = false;
2592 switch (containedRetention) {
2593 case RUNTIME:
2594 if (containerRetention != Attribute.RetentionPolicy.RUNTIME) {
2595 error = true;
2596 }
2597 break;
2598 case CLASS:
2599 if (containerRetention == Attribute.RetentionPolicy.SOURCE) {
2600 error = true;
2601 }
2602 }
2603 if (error ) {
2604 log.error(pos, "invalid.containedby.annotation.retention",
2605 container, containerRetention,
2606 contained, containedRetention);
2607 }
2608 }
2610 private void validateDocumented(Symbol container, Symbol contained, DiagnosticPosition pos) {
2611 if (contained.attribute(syms.documentedType.tsym) != null) {
2612 if (container.attribute(syms.documentedType.tsym) == null) {
2613 log.error(pos, "invalid.containedby.annotation.not.documented", container, contained);
2614 }
2615 }
2616 }
2618 private void validateInherited(Symbol container, Symbol contained, DiagnosticPosition pos) {
2619 if (contained.attribute(syms.inheritedType.tsym) != null) {
2620 if (container.attribute(syms.inheritedType.tsym) == null) {
2621 log.error(pos, "invalid.containedby.annotation.not.inherited", container, contained);
2622 }
2623 }
2624 }
2626 private void validateTarget(Symbol container, Symbol contained, DiagnosticPosition pos) {
2627 Attribute.Array containedTarget = getAttributeTargetAttribute(contained);
2629 // If contained has no Target, we are done
2630 if (containedTarget == null) {
2631 return;
2632 }
2634 // If contained has Target m1, container must have a Target
2635 // annotation, m2, and m2 must be a subset of m1. (This is
2636 // trivially true if contained has no target as per above).
2638 // contained has target, but container has not, error
2639 Attribute.Array containerTarget = getAttributeTargetAttribute(container);
2640 if (containerTarget == null) {
2641 log.error(pos, "invalid.containedby.annotation.incompatible.target", container, contained);
2642 return;
2643 }
2645 Set<Name> containerTargets = new HashSet<Name>();
2646 for (Attribute app : containerTarget.values) {
2647 if (!(app instanceof Attribute.Enum)) {
2648 continue; // recovery
2649 }
2650 Attribute.Enum e = (Attribute.Enum)app;
2651 containerTargets.add(e.value.name);
2652 }
2654 Set<Name> containedTargets = new HashSet<Name>();
2655 for (Attribute app : containedTarget.values) {
2656 if (!(app instanceof Attribute.Enum)) {
2657 continue; // recovery
2658 }
2659 Attribute.Enum e = (Attribute.Enum)app;
2660 containedTargets.add(e.value.name);
2661 }
2663 if (!isTargetSubset(containedTargets, containerTargets)) {
2664 log.error(pos, "invalid.containedby.annotation.incompatible.target", container, contained);
2665 }
2666 }
2668 /** Checks that t is a subset of s, with respect to ElementType
2669 * semantics, specifically {ANNOTATION_TYPE} is a subset of {TYPE}
2670 */
2671 private boolean isTargetSubset(Set<Name> s, Set<Name> t) {
2672 // Check that all elements in t are present in s
2673 for (Name n2 : t) {
2674 boolean currentElementOk = false;
2675 for (Name n1 : s) {
2676 if (n1 == n2) {
2677 currentElementOk = true;
2678 break;
2679 } else if (n1 == names.TYPE && n2 == names.ANNOTATION_TYPE) {
2680 currentElementOk = true;
2681 break;
2682 }
2683 }
2684 if (!currentElementOk)
2685 return false;
2686 }
2687 return true;
2688 }
2690 private void validateDefault(Symbol container, Symbol contained, DiagnosticPosition pos) {
2691 // validate that all other elements of containing type has defaults
2692 Scope scope = container.members();
2693 for(Symbol elm : scope.getElements()) {
2694 if (elm.name != names.value &&
2695 elm.kind == Kinds.MTH &&
2696 ((MethodSymbol)elm).defaultValue == null) {
2697 log.error(pos,
2698 "invalid.containedby.annotation.elem.nondefault",
2699 container,
2700 elm);
2701 }
2702 }
2703 }
2705 /** Is s a method symbol that overrides a method in a superclass? */
2706 boolean isOverrider(Symbol s) {
2707 if (s.kind != MTH || s.isStatic())
2708 return false;
2709 MethodSymbol m = (MethodSymbol)s;
2710 TypeSymbol owner = (TypeSymbol)m.owner;
2711 for (Type sup : types.closure(owner.type)) {
2712 if (sup == owner.type)
2713 continue; // skip "this"
2714 Scope scope = sup.tsym.members();
2715 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
2716 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
2717 return true;
2718 }
2719 }
2720 return false;
2721 }
2723 /** Is the annotation applicable to the symbol? */
2724 boolean annotationApplicable(JCAnnotation a, Symbol s) {
2725 Attribute.Array arr = getAttributeTargetAttribute(a.annotationType.type.tsym);
2726 if (arr == null) {
2727 return true;
2728 }
2729 for (Attribute app : arr.values) {
2730 if (!(app instanceof Attribute.Enum)) return true; // recovery
2731 Attribute.Enum e = (Attribute.Enum) app;
2732 if (e.value.name == names.TYPE)
2733 { if (s.kind == TYP) return true; }
2734 else if (e.value.name == names.FIELD)
2735 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
2736 else if (e.value.name == names.METHOD)
2737 { if (s.kind == MTH && !s.isConstructor()) return true; }
2738 else if (e.value.name == names.PARAMETER)
2739 { if (s.kind == VAR &&
2740 s.owner.kind == MTH &&
2741 (s.flags() & PARAMETER) != 0)
2742 return true;
2743 }
2744 else if (e.value.name == names.CONSTRUCTOR)
2745 { if (s.kind == MTH && s.isConstructor()) return true; }
2746 else if (e.value.name == names.LOCAL_VARIABLE)
2747 { if (s.kind == VAR && s.owner.kind == MTH &&
2748 (s.flags() & PARAMETER) == 0)
2749 return true;
2750 }
2751 else if (e.value.name == names.ANNOTATION_TYPE)
2752 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
2753 return true;
2754 }
2755 else if (e.value.name == names.PACKAGE)
2756 { if (s.kind == PCK) return true; }
2757 else if (e.value.name == names.TYPE_USE)
2758 { if (s.kind == TYP ||
2759 s.kind == VAR ||
2760 (s.kind == MTH && !s.isConstructor() &&
2761 s.type.getReturnType().tag != VOID))
2762 return true;
2763 }
2764 else
2765 return true; // recovery
2766 }
2767 return false;
2768 }
2771 Attribute.Array getAttributeTargetAttribute(Symbol s) {
2772 Attribute.Compound atTarget =
2773 s.attribute(syms.annotationTargetType.tsym);
2774 if (atTarget == null) return null; // ok, is applicable
2775 Attribute atValue = atTarget.member(names.value);
2776 if (!(atValue instanceof Attribute.Array)) return null; // error recovery
2777 return (Attribute.Array) atValue;
2778 }
2780 /** Check an annotation value.
2781 */
2782 public void validateAnnotation(JCAnnotation a) {
2783 // collect an inventory of the members (sorted alphabetically)
2784 Set<MethodSymbol> members = new TreeSet<MethodSymbol>(new Comparator<Symbol>() {
2785 public int compare(Symbol t, Symbol t1) {
2786 return t.name.compareTo(t1.name);
2787 }
2788 });
2789 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
2790 e != null;
2791 e = e.sibling)
2792 if (e.sym.kind == MTH)
2793 members.add((MethodSymbol) e.sym);
2795 // count them off as they're annotated
2796 for (JCTree arg : a.args) {
2797 if (!arg.hasTag(ASSIGN)) continue; // recovery
2798 JCAssign assign = (JCAssign) arg;
2799 Symbol m = TreeInfo.symbol(assign.lhs);
2800 if (m == null || m.type.isErroneous()) continue;
2801 if (!members.remove(m))
2802 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
2803 m.name, a.type);
2804 }
2806 // all the remaining ones better have default values
2807 ListBuffer<Name> missingDefaults = ListBuffer.lb();
2808 for (MethodSymbol m : members) {
2809 if (m.defaultValue == null && !m.type.isErroneous()) {
2810 missingDefaults.append(m.name);
2811 }
2812 }
2813 if (missingDefaults.nonEmpty()) {
2814 String key = (missingDefaults.size() > 1)
2815 ? "annotation.missing.default.value.1"
2816 : "annotation.missing.default.value";
2817 log.error(a.pos(), key, a.type, missingDefaults);
2818 }
2820 // special case: java.lang.annotation.Target must not have
2821 // repeated values in its value member
2822 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
2823 a.args.tail == null)
2824 return;
2826 if (!a.args.head.hasTag(ASSIGN)) return; // error recovery
2827 JCAssign assign = (JCAssign) a.args.head;
2828 Symbol m = TreeInfo.symbol(assign.lhs);
2829 if (m.name != names.value) return;
2830 JCTree rhs = assign.rhs;
2831 if (!rhs.hasTag(NEWARRAY)) return;
2832 JCNewArray na = (JCNewArray) rhs;
2833 Set<Symbol> targets = new HashSet<Symbol>();
2834 for (JCTree elem : na.elems) {
2835 if (!targets.add(TreeInfo.symbol(elem))) {
2836 log.error(elem.pos(), "repeated.annotation.target");
2837 }
2838 }
2839 }
2841 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
2842 if (allowAnnotations &&
2843 lint.isEnabled(LintCategory.DEP_ANN) &&
2844 (s.flags() & DEPRECATED) != 0 &&
2845 !syms.deprecatedType.isErroneous() &&
2846 s.attribute(syms.deprecatedType.tsym) == null) {
2847 log.warning(LintCategory.DEP_ANN,
2848 pos, "missing.deprecated.annotation");
2849 }
2850 }
2852 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
2853 if ((s.flags() & DEPRECATED) != 0 &&
2854 (other.flags() & DEPRECATED) == 0 &&
2855 s.outermostClass() != other.outermostClass()) {
2856 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
2857 @Override
2858 public void report() {
2859 warnDeprecated(pos, s);
2860 }
2861 });
2862 }
2863 }
2865 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
2866 if ((s.flags() & PROPRIETARY) != 0) {
2867 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
2868 public void report() {
2869 if (enableSunApiLintControl)
2870 warnSunApi(pos, "sun.proprietary", s);
2871 else
2872 log.mandatoryWarning(pos, "sun.proprietary", s);
2873 }
2874 });
2875 }
2876 }
2878 /* *************************************************************************
2879 * Check for recursive annotation elements.
2880 **************************************************************************/
2882 /** Check for cycles in the graph of annotation elements.
2883 */
2884 void checkNonCyclicElements(JCClassDecl tree) {
2885 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
2886 Assert.check((tree.sym.flags_field & LOCKED) == 0);
2887 try {
2888 tree.sym.flags_field |= LOCKED;
2889 for (JCTree def : tree.defs) {
2890 if (!def.hasTag(METHODDEF)) continue;
2891 JCMethodDecl meth = (JCMethodDecl)def;
2892 checkAnnotationResType(meth.pos(), meth.restype.type);
2893 }
2894 } finally {
2895 tree.sym.flags_field &= ~LOCKED;
2896 tree.sym.flags_field |= ACYCLIC_ANN;
2897 }
2898 }
2900 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
2901 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
2902 return;
2903 if ((tsym.flags_field & LOCKED) != 0) {
2904 log.error(pos, "cyclic.annotation.element");
2905 return;
2906 }
2907 try {
2908 tsym.flags_field |= LOCKED;
2909 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
2910 Symbol s = e.sym;
2911 if (s.kind != Kinds.MTH)
2912 continue;
2913 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
2914 }
2915 } finally {
2916 tsym.flags_field &= ~LOCKED;
2917 tsym.flags_field |= ACYCLIC_ANN;
2918 }
2919 }
2921 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
2922 switch (type.tag) {
2923 case TypeTags.CLASS:
2924 if ((type.tsym.flags() & ANNOTATION) != 0)
2925 checkNonCyclicElementsInternal(pos, type.tsym);
2926 break;
2927 case TypeTags.ARRAY:
2928 checkAnnotationResType(pos, types.elemtype(type));
2929 break;
2930 default:
2931 break; // int etc
2932 }
2933 }
2935 /* *************************************************************************
2936 * Check for cycles in the constructor call graph.
2937 **************************************************************************/
2939 /** Check for cycles in the graph of constructors calling other
2940 * constructors.
2941 */
2942 void checkCyclicConstructors(JCClassDecl tree) {
2943 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
2945 // enter each constructor this-call into the map
2946 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2947 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
2948 if (app == null) continue;
2949 JCMethodDecl meth = (JCMethodDecl) l.head;
2950 if (TreeInfo.name(app.meth) == names._this) {
2951 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
2952 } else {
2953 meth.sym.flags_field |= ACYCLIC;
2954 }
2955 }
2957 // Check for cycles in the map
2958 Symbol[] ctors = new Symbol[0];
2959 ctors = callMap.keySet().toArray(ctors);
2960 for (Symbol caller : ctors) {
2961 checkCyclicConstructor(tree, caller, callMap);
2962 }
2963 }
2965 /** Look in the map to see if the given constructor is part of a
2966 * call cycle.
2967 */
2968 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
2969 Map<Symbol,Symbol> callMap) {
2970 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
2971 if ((ctor.flags_field & LOCKED) != 0) {
2972 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
2973 "recursive.ctor.invocation");
2974 } else {
2975 ctor.flags_field |= LOCKED;
2976 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2977 ctor.flags_field &= ~LOCKED;
2978 }
2979 ctor.flags_field |= ACYCLIC;
2980 }
2981 }
2983 /* *************************************************************************
2984 * Miscellaneous
2985 **************************************************************************/
2987 /**
2988 * Return the opcode of the operator but emit an error if it is an
2989 * error.
2990 * @param pos position for error reporting.
2991 * @param operator an operator
2992 * @param tag a tree tag
2993 * @param left type of left hand side
2994 * @param right type of right hand side
2995 */
2996 int checkOperator(DiagnosticPosition pos,
2997 OperatorSymbol operator,
2998 JCTree.Tag tag,
2999 Type left,
3000 Type right) {
3001 if (operator.opcode == ByteCodes.error) {
3002 log.error(pos,
3003 "operator.cant.be.applied.1",
3004 treeinfo.operatorName(tag),
3005 left, right);
3006 }
3007 return operator.opcode;
3008 }
3011 /**
3012 * Check for division by integer constant zero
3013 * @param pos Position for error reporting.
3014 * @param operator The operator for the expression
3015 * @param operand The right hand operand for the expression
3016 */
3017 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
3018 if (operand.constValue() != null
3019 && lint.isEnabled(LintCategory.DIVZERO)
3020 && operand.tag <= LONG
3021 && ((Number) (operand.constValue())).longValue() == 0) {
3022 int opc = ((OperatorSymbol)operator).opcode;
3023 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
3024 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
3025 log.warning(LintCategory.DIVZERO, pos, "div.zero");
3026 }
3027 }
3028 }
3030 /**
3031 * Check for empty statements after if
3032 */
3033 void checkEmptyIf(JCIf tree) {
3034 if (tree.thenpart.hasTag(SKIP) && tree.elsepart == null &&
3035 lint.isEnabled(LintCategory.EMPTY))
3036 log.warning(LintCategory.EMPTY, tree.thenpart.pos(), "empty.if");
3037 }
3039 /** Check that symbol is unique in given scope.
3040 * @param pos Position for error reporting.
3041 * @param sym The symbol.
3042 * @param s The scope.
3043 */
3044 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
3045 if (sym.type.isErroneous())
3046 return true;
3047 if (sym.owner.name == names.any) return false;
3048 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
3049 if (sym != e.sym &&
3050 (e.sym.flags() & CLASH) == 0 &&
3051 sym.kind == e.sym.kind &&
3052 sym.name != names.error &&
3053 (sym.kind != MTH || types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
3054 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS)) {
3055 varargsDuplicateError(pos, sym, e.sym);
3056 return true;
3057 } else if (sym.kind == MTH && !types.hasSameArgs(sym.type, e.sym.type, false)) {
3058 duplicateErasureError(pos, sym, e.sym);
3059 sym.flags_field |= CLASH;
3060 return true;
3061 } else {
3062 duplicateError(pos, e.sym);
3063 return false;
3064 }
3065 }
3066 }
3067 return true;
3068 }
3070 /** Report duplicate declaration error.
3071 */
3072 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
3073 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
3074 log.error(pos, "name.clash.same.erasure", sym1, sym2);
3075 }
3076 }
3078 /** Check that single-type import is not already imported or top-level defined,
3079 * but make an exception for two single-type imports which denote the same type.
3080 * @param pos Position for error reporting.
3081 * @param sym The symbol.
3082 * @param s The scope
3083 */
3084 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
3085 return checkUniqueImport(pos, sym, s, false);
3086 }
3088 /** Check that static single-type import is not already imported or top-level defined,
3089 * but make an exception for two single-type imports which denote the same type.
3090 * @param pos Position for error reporting.
3091 * @param sym The symbol.
3092 * @param s The scope
3093 * @param staticImport Whether or not this was a static import
3094 */
3095 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
3096 return checkUniqueImport(pos, sym, s, true);
3097 }
3099 /** Check that single-type import is not already imported or top-level defined,
3100 * but make an exception for two single-type imports which denote the same type.
3101 * @param pos Position for error reporting.
3102 * @param sym The symbol.
3103 * @param s The scope.
3104 * @param staticImport Whether or not this was a static import
3105 */
3106 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
3107 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
3108 // is encountered class entered via a class declaration?
3109 boolean isClassDecl = e.scope == s;
3110 if ((isClassDecl || sym != e.sym) &&
3111 sym.kind == e.sym.kind &&
3112 sym.name != names.error) {
3113 if (!e.sym.type.isErroneous()) {
3114 String what = e.sym.toString();
3115 if (!isClassDecl) {
3116 if (staticImport)
3117 log.error(pos, "already.defined.static.single.import", what);
3118 else
3119 log.error(pos, "already.defined.single.import", what);
3120 }
3121 else if (sym != e.sym)
3122 log.error(pos, "already.defined.this.unit", what);
3123 }
3124 return false;
3125 }
3126 }
3127 return true;
3128 }
3130 /** Check that a qualified name is in canonical form (for import decls).
3131 */
3132 public void checkCanonical(JCTree tree) {
3133 if (!isCanonical(tree))
3134 log.error(tree.pos(), "import.requires.canonical",
3135 TreeInfo.symbol(tree));
3136 }
3137 // where
3138 private boolean isCanonical(JCTree tree) {
3139 while (tree.hasTag(SELECT)) {
3140 JCFieldAccess s = (JCFieldAccess) tree;
3141 if (s.sym.owner != TreeInfo.symbol(s.selected))
3142 return false;
3143 tree = s.selected;
3144 }
3145 return true;
3146 }
3148 private class ConversionWarner extends Warner {
3149 final String uncheckedKey;
3150 final Type found;
3151 final Type expected;
3152 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
3153 super(pos);
3154 this.uncheckedKey = uncheckedKey;
3155 this.found = found;
3156 this.expected = expected;
3157 }
3159 @Override
3160 public void warn(LintCategory lint) {
3161 boolean warned = this.warned;
3162 super.warn(lint);
3163 if (warned) return; // suppress redundant diagnostics
3164 switch (lint) {
3165 case UNCHECKED:
3166 Check.this.warnUnchecked(pos(), "prob.found.req", diags.fragment(uncheckedKey), found, expected);
3167 break;
3168 case VARARGS:
3169 if (method != null &&
3170 method.attribute(syms.trustMeType.tsym) != null &&
3171 isTrustMeAllowedOnMethod(method) &&
3172 !types.isReifiable(method.type.getParameterTypes().last())) {
3173 Check.this.warnUnsafeVararg(pos(), "varargs.unsafe.use.varargs.param", method.params.last());
3174 }
3175 break;
3176 default:
3177 throw new AssertionError("Unexpected lint: " + lint);
3178 }
3179 }
3180 }
3182 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
3183 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
3184 }
3186 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
3187 return new ConversionWarner(pos, "unchecked.assign", found, expected);
3188 }
3189 }