Wed, 16 Jan 2013 17:40:28 +0000
8005964: Regression: difference in error recovery after ambiguity causes JCK test failure
Summary: Wrong implementation of ResolveError.access in AmbiguityError
Reviewed-by: jjh
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 com.sun.tools.javac.api.Formattable.LocalizedString;
29 import com.sun.tools.javac.code.*;
30 import com.sun.tools.javac.code.Symbol.*;
31 import com.sun.tools.javac.code.Type.*;
32 import com.sun.tools.javac.comp.Attr.ResultInfo;
33 import com.sun.tools.javac.comp.Check.CheckContext;
34 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
35 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
36 import com.sun.tools.javac.comp.DeferredAttr.DeferredType;
37 import com.sun.tools.javac.comp.Infer.InferenceContext;
38 import com.sun.tools.javac.comp.Infer.InferenceContext.FreeTypeListener;
39 import com.sun.tools.javac.comp.Resolve.MethodResolutionContext.Candidate;
40 import com.sun.tools.javac.jvm.*;
41 import com.sun.tools.javac.tree.*;
42 import com.sun.tools.javac.tree.JCTree.*;
43 import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind;
44 import com.sun.tools.javac.util.*;
45 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
46 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
47 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
49 import java.util.Arrays;
50 import java.util.Collection;
51 import java.util.EnumMap;
52 import java.util.EnumSet;
53 import java.util.Iterator;
54 import java.util.LinkedHashMap;
55 import java.util.LinkedHashSet;
56 import java.util.Map;
57 import java.util.Set;
59 import javax.lang.model.element.ElementVisitor;
61 import static com.sun.tools.javac.code.Flags.*;
62 import static com.sun.tools.javac.code.Flags.BLOCK;
63 import static com.sun.tools.javac.code.Kinds.*;
64 import static com.sun.tools.javac.code.Kinds.ERRONEOUS;
65 import static com.sun.tools.javac.code.TypeTag.*;
66 import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*;
67 import static com.sun.tools.javac.tree.JCTree.Tag.*;
69 /** Helper class for name resolution, used mostly by the attribution phase.
70 *
71 * <p><b>This is NOT part of any supported API.
72 * If you write code that depends on this, you do so at your own risk.
73 * This code and its internal interfaces are subject to change or
74 * deletion without notice.</b>
75 */
76 public class Resolve {
77 protected static final Context.Key<Resolve> resolveKey =
78 new Context.Key<Resolve>();
80 Names names;
81 Log log;
82 Symtab syms;
83 Attr attr;
84 DeferredAttr deferredAttr;
85 Check chk;
86 Infer infer;
87 ClassReader reader;
88 TreeInfo treeinfo;
89 Types types;
90 JCDiagnostic.Factory diags;
91 public final boolean boxingEnabled; // = source.allowBoxing();
92 public final boolean varargsEnabled; // = source.allowVarargs();
93 public final boolean allowMethodHandles;
94 public final boolean allowDefaultMethods;
95 private final boolean debugResolve;
96 final EnumSet<VerboseResolutionMode> verboseResolutionMode;
98 Scope polymorphicSignatureScope;
100 protected Resolve(Context context) {
101 context.put(resolveKey, this);
102 syms = Symtab.instance(context);
104 varNotFound = new
105 SymbolNotFoundError(ABSENT_VAR);
106 methodNotFound = new
107 SymbolNotFoundError(ABSENT_MTH);
108 typeNotFound = new
109 SymbolNotFoundError(ABSENT_TYP);
111 names = Names.instance(context);
112 log = Log.instance(context);
113 attr = Attr.instance(context);
114 deferredAttr = DeferredAttr.instance(context);
115 chk = Check.instance(context);
116 infer = Infer.instance(context);
117 reader = ClassReader.instance(context);
118 treeinfo = TreeInfo.instance(context);
119 types = Types.instance(context);
120 diags = JCDiagnostic.Factory.instance(context);
121 Source source = Source.instance(context);
122 boxingEnabled = source.allowBoxing();
123 varargsEnabled = source.allowVarargs();
124 Options options = Options.instance(context);
125 debugResolve = options.isSet("debugresolve");
126 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
127 Target target = Target.instance(context);
128 allowMethodHandles = target.hasMethodHandles();
129 allowDefaultMethods = source.allowDefaultMethods();
130 polymorphicSignatureScope = new Scope(syms.noSymbol);
132 inapplicableMethodException = new InapplicableMethodException(diags);
133 }
135 /** error symbols, which are returned when resolution fails
136 */
137 private final SymbolNotFoundError varNotFound;
138 private final SymbolNotFoundError methodNotFound;
139 private final SymbolNotFoundError typeNotFound;
141 public static Resolve instance(Context context) {
142 Resolve instance = context.get(resolveKey);
143 if (instance == null)
144 instance = new Resolve(context);
145 return instance;
146 }
148 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support">
149 enum VerboseResolutionMode {
150 SUCCESS("success"),
151 FAILURE("failure"),
152 APPLICABLE("applicable"),
153 INAPPLICABLE("inapplicable"),
154 DEFERRED_INST("deferred-inference"),
155 PREDEF("predef"),
156 OBJECT_INIT("object-init"),
157 INTERNAL("internal");
159 final String opt;
161 private VerboseResolutionMode(String opt) {
162 this.opt = opt;
163 }
165 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) {
166 String s = opts.get("verboseResolution");
167 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class);
168 if (s == null) return res;
169 if (s.contains("all")) {
170 res = EnumSet.allOf(VerboseResolutionMode.class);
171 }
172 Collection<String> args = Arrays.asList(s.split(","));
173 for (VerboseResolutionMode mode : values()) {
174 if (args.contains(mode.opt)) {
175 res.add(mode);
176 } else if (args.contains("-" + mode.opt)) {
177 res.remove(mode);
178 }
179 }
180 return res;
181 }
182 }
184 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site,
185 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) {
186 boolean success = bestSoFar.kind < ERRONEOUS;
188 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) {
189 return;
190 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) {
191 return;
192 }
194 if (bestSoFar.name == names.init &&
195 bestSoFar.owner == syms.objectType.tsym &&
196 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) {
197 return; //skip diags for Object constructor resolution
198 } else if (site == syms.predefClass.type &&
199 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) {
200 return; //skip spurious diags for predef symbols (i.e. operators)
201 } else if (currentResolutionContext.internalResolution &&
202 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) {
203 return;
204 }
206 int pos = 0;
207 int mostSpecificPos = -1;
208 ListBuffer<JCDiagnostic> subDiags = ListBuffer.lb();
209 for (Candidate c : currentResolutionContext.candidates) {
210 if (currentResolutionContext.step != c.step ||
211 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) ||
212 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) {
213 continue;
214 } else {
215 subDiags.append(c.isApplicable() ?
216 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) :
217 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details));
218 if (c.sym == bestSoFar)
219 mostSpecificPos = pos;
220 pos++;
221 }
222 }
223 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1";
224 List<Type> argtypes2 = Type.map(argtypes,
225 deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step));
226 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name,
227 site.tsym, mostSpecificPos, currentResolutionContext.step,
228 methodArguments(argtypes2),
229 methodArguments(typeargtypes));
230 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
231 log.report(d);
232 }
234 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) {
235 JCDiagnostic subDiag = null;
236 if (sym.type.hasTag(FORALL)) {
237 subDiag = diags.fragment("partial.inst.sig", inst);
238 }
240 String key = subDiag == null ?
241 "applicable.method.found" :
242 "applicable.method.found.1";
244 return diags.fragment(key, pos, sym, subDiag);
245 }
247 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) {
248 return diags.fragment("not.applicable.method.found", pos, sym, subDiag);
249 }
250 // </editor-fold>
252 /* ************************************************************************
253 * Identifier resolution
254 *************************************************************************/
256 /** An environment is "static" if its static level is greater than
257 * the one of its outer environment
258 */
259 protected static boolean isStatic(Env<AttrContext> env) {
260 return env.info.staticLevel > env.outer.info.staticLevel;
261 }
263 /** An environment is an "initializer" if it is a constructor or
264 * an instance initializer.
265 */
266 static boolean isInitializer(Env<AttrContext> env) {
267 Symbol owner = env.info.scope.owner;
268 return owner.isConstructor() ||
269 owner.owner.kind == TYP &&
270 (owner.kind == VAR ||
271 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
272 (owner.flags() & STATIC) == 0;
273 }
275 /** Is class accessible in given evironment?
276 * @param env The current environment.
277 * @param c The class whose accessibility is checked.
278 */
279 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
280 return isAccessible(env, c, false);
281 }
283 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) {
284 boolean isAccessible = false;
285 switch ((short)(c.flags() & AccessFlags)) {
286 case PRIVATE:
287 isAccessible =
288 env.enclClass.sym.outermostClass() ==
289 c.owner.outermostClass();
290 break;
291 case 0:
292 isAccessible =
293 env.toplevel.packge == c.owner // fast special case
294 ||
295 env.toplevel.packge == c.packge()
296 ||
297 // Hack: this case is added since synthesized default constructors
298 // of anonymous classes should be allowed to access
299 // classes which would be inaccessible otherwise.
300 env.enclMethod != null &&
301 (env.enclMethod.mods.flags & ANONCONSTR) != 0;
302 break;
303 default: // error recovery
304 case PUBLIC:
305 isAccessible = true;
306 break;
307 case PROTECTED:
308 isAccessible =
309 env.toplevel.packge == c.owner // fast special case
310 ||
311 env.toplevel.packge == c.packge()
312 ||
313 isInnerSubClass(env.enclClass.sym, c.owner);
314 break;
315 }
316 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
317 isAccessible :
318 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
319 }
320 //where
321 /** Is given class a subclass of given base class, or an inner class
322 * of a subclass?
323 * Return null if no such class exists.
324 * @param c The class which is the subclass or is contained in it.
325 * @param base The base class
326 */
327 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
328 while (c != null && !c.isSubClass(base, types)) {
329 c = c.owner.enclClass();
330 }
331 return c != null;
332 }
334 boolean isAccessible(Env<AttrContext> env, Type t) {
335 return isAccessible(env, t, false);
336 }
338 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) {
339 return (t.hasTag(ARRAY))
340 ? isAccessible(env, types.elemtype(t))
341 : isAccessible(env, t.tsym, checkInner);
342 }
344 /** Is symbol accessible as a member of given type in given evironment?
345 * @param env The current environment.
346 * @param site The type of which the tested symbol is regarded
347 * as a member.
348 * @param sym The symbol.
349 */
350 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
351 return isAccessible(env, site, sym, false);
352 }
353 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) {
354 if (sym.name == names.init && sym.owner != site.tsym) return false;
355 switch ((short)(sym.flags() & AccessFlags)) {
356 case PRIVATE:
357 return
358 (env.enclClass.sym == sym.owner // fast special case
359 ||
360 env.enclClass.sym.outermostClass() ==
361 sym.owner.outermostClass())
362 &&
363 sym.isInheritedIn(site.tsym, types);
364 case 0:
365 return
366 (env.toplevel.packge == sym.owner.owner // fast special case
367 ||
368 env.toplevel.packge == sym.packge())
369 &&
370 isAccessible(env, site, checkInner)
371 &&
372 sym.isInheritedIn(site.tsym, types)
373 &&
374 notOverriddenIn(site, sym);
375 case PROTECTED:
376 return
377 (env.toplevel.packge == sym.owner.owner // fast special case
378 ||
379 env.toplevel.packge == sym.packge()
380 ||
381 isProtectedAccessible(sym, env.enclClass.sym, site)
382 ||
383 // OK to select instance method or field from 'super' or type name
384 // (but type names should be disallowed elsewhere!)
385 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
386 &&
387 isAccessible(env, site, checkInner)
388 &&
389 notOverriddenIn(site, sym);
390 default: // this case includes erroneous combinations as well
391 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
392 }
393 }
394 //where
395 /* `sym' is accessible only if not overridden by
396 * another symbol which is a member of `site'
397 * (because, if it is overridden, `sym' is not strictly
398 * speaking a member of `site'). A polymorphic signature method
399 * cannot be overridden (e.g. MH.invokeExact(Object[])).
400 */
401 private boolean notOverriddenIn(Type site, Symbol sym) {
402 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
403 return true;
404 else {
405 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
406 return (s2 == null || s2 == sym || sym.owner == s2.owner ||
407 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
408 }
409 }
410 //where
411 /** Is given protected symbol accessible if it is selected from given site
412 * and the selection takes place in given class?
413 * @param sym The symbol with protected access
414 * @param c The class where the access takes place
415 * @site The type of the qualifier
416 */
417 private
418 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
419 while (c != null &&
420 !(c.isSubClass(sym.owner, types) &&
421 (c.flags() & INTERFACE) == 0 &&
422 // In JLS 2e 6.6.2.1, the subclass restriction applies
423 // only to instance fields and methods -- types are excluded
424 // regardless of whether they are declared 'static' or not.
425 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || site.tsym.isSubClass(c, types))))
426 c = c.owner.enclClass();
427 return c != null;
428 }
430 /**
431 * Performs a recursive scan of a type looking for accessibility problems
432 * from current attribution environment
433 */
434 void checkAccessibleType(Env<AttrContext> env, Type t) {
435 accessibilityChecker.visit(t, env);
436 }
438 /**
439 * Accessibility type-visitor
440 */
441 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker =
442 new Types.SimpleVisitor<Void, Env<AttrContext>>() {
444 void visit(List<Type> ts, Env<AttrContext> env) {
445 for (Type t : ts) {
446 visit(t, env);
447 }
448 }
450 public Void visitType(Type t, Env<AttrContext> env) {
451 return null;
452 }
454 @Override
455 public Void visitArrayType(ArrayType t, Env<AttrContext> env) {
456 visit(t.elemtype, env);
457 return null;
458 }
460 @Override
461 public Void visitClassType(ClassType t, Env<AttrContext> env) {
462 visit(t.getTypeArguments(), env);
463 if (!isAccessible(env, t, true)) {
464 accessBase(new AccessError(t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true);
465 }
466 return null;
467 }
469 @Override
470 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) {
471 visit(t.type, env);
472 return null;
473 }
475 @Override
476 public Void visitMethodType(MethodType t, Env<AttrContext> env) {
477 visit(t.getParameterTypes(), env);
478 visit(t.getReturnType(), env);
479 visit(t.getThrownTypes(), env);
480 return null;
481 }
482 };
484 /** Try to instantiate the type of a method so that it fits
485 * given type arguments and argument types. If succesful, return
486 * the method's instantiated type, else return null.
487 * The instantiation will take into account an additional leading
488 * formal parameter if the method is an instance method seen as a member
489 * of un underdetermined site In this case, we treat site as an additional
490 * parameter and the parameters of the class containing the method as
491 * additional type variables that get instantiated.
492 *
493 * @param env The current environment
494 * @param site The type of which the method is a member.
495 * @param m The method symbol.
496 * @param argtypes The invocation's given value arguments.
497 * @param typeargtypes The invocation's given type arguments.
498 * @param allowBoxing Allow boxing conversions of arguments.
499 * @param useVarargs Box trailing arguments into an array for varargs.
500 */
501 Type rawInstantiate(Env<AttrContext> env,
502 Type site,
503 Symbol m,
504 ResultInfo resultInfo,
505 List<Type> argtypes,
506 List<Type> typeargtypes,
507 boolean allowBoxing,
508 boolean useVarargs,
509 MethodCheck methodCheck,
510 Warner warn) throws Infer.InferenceException {
512 Type mt = types.memberType(site, m);
513 // tvars is the list of formal type variables for which type arguments
514 // need to inferred.
515 List<Type> tvars = List.nil();
516 if (typeargtypes == null) typeargtypes = List.nil();
517 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
518 // This is not a polymorphic method, but typeargs are supplied
519 // which is fine, see JLS 15.12.2.1
520 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
521 ForAll pmt = (ForAll) mt;
522 if (typeargtypes.length() != pmt.tvars.length())
523 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args
524 // Check type arguments are within bounds
525 List<Type> formals = pmt.tvars;
526 List<Type> actuals = typeargtypes;
527 while (formals.nonEmpty() && actuals.nonEmpty()) {
528 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
529 pmt.tvars, typeargtypes);
530 for (; bounds.nonEmpty(); bounds = bounds.tail)
531 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn))
532 throw inapplicableMethodException.setMessage("explicit.param.do.not.conform.to.bounds",actuals.head, bounds);
533 formals = formals.tail;
534 actuals = actuals.tail;
535 }
536 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
537 } else if (mt.hasTag(FORALL)) {
538 ForAll pmt = (ForAll) mt;
539 List<Type> tvars1 = types.newInstances(pmt.tvars);
540 tvars = tvars.appendList(tvars1);
541 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
542 }
544 // find out whether we need to go the slow route via infer
545 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/
546 for (List<Type> l = argtypes;
547 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
548 l = l.tail) {
549 if (l.head.hasTag(FORALL)) instNeeded = true;
550 }
552 if (instNeeded)
553 return infer.instantiateMethod(env,
554 tvars,
555 (MethodType)mt,
556 resultInfo,
557 m,
558 argtypes,
559 allowBoxing,
560 useVarargs,
561 currentResolutionContext,
562 methodCheck,
563 warn);
565 methodCheck.argumentsAcceptable(env, currentResolutionContext.deferredAttrContext(m, infer.emptyContext),
566 argtypes, mt.getParameterTypes(), warn);
567 return mt;
568 }
570 Type checkMethod(Env<AttrContext> env,
571 Type site,
572 Symbol m,
573 ResultInfo resultInfo,
574 List<Type> argtypes,
575 List<Type> typeargtypes,
576 Warner warn) {
577 MethodResolutionContext prevContext = currentResolutionContext;
578 try {
579 currentResolutionContext = new MethodResolutionContext();
580 currentResolutionContext.attrMode = DeferredAttr.AttrMode.CHECK;
581 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase;
582 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
583 step.isBoxingRequired(), step.isVarargsRequired(), resolveMethodCheck, warn);
584 }
585 finally {
586 currentResolutionContext = prevContext;
587 }
588 }
590 /** Same but returns null instead throwing a NoInstanceException
591 */
592 Type instantiate(Env<AttrContext> env,
593 Type site,
594 Symbol m,
595 ResultInfo resultInfo,
596 List<Type> argtypes,
597 List<Type> typeargtypes,
598 boolean allowBoxing,
599 boolean useVarargs,
600 MethodCheck methodCheck,
601 Warner warn) {
602 try {
603 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
604 allowBoxing, useVarargs, methodCheck, warn);
605 } catch (InapplicableMethodException ex) {
606 return null;
607 }
608 }
610 /**
611 * This interface defines an entry point that should be used to perform a
612 * method check. A method check usually consist in determining as to whether
613 * a set of types (actuals) is compatible with another set of types (formals).
614 * Since the notion of compatibility can vary depending on the circumstances,
615 * this interfaces allows to easily add new pluggable method check routines.
616 */
617 interface MethodCheck {
618 /**
619 * Main method check routine. A method check usually consist in determining
620 * as to whether a set of types (actuals) is compatible with another set of
621 * types (formals). If an incompatibility is found, an unchecked exception
622 * is assumed to be thrown.
623 */
624 void argumentsAcceptable(Env<AttrContext> env,
625 DeferredAttrContext deferredAttrContext,
626 List<Type> argtypes,
627 List<Type> formals,
628 Warner warn);
629 }
631 /**
632 * Helper enum defining all method check diagnostics (used by resolveMethodCheck).
633 */
634 enum MethodCheckDiag {
635 /**
636 * Actuals and formals differs in length.
637 */
638 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"),
639 /**
640 * An actual is incompatible with a formal.
641 */
642 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"),
643 /**
644 * An actual is incompatible with the varargs element type.
645 */
646 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"),
647 /**
648 * The varargs element type is inaccessible.
649 */
650 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type");
652 final String basicKey;
653 final String inferKey;
655 MethodCheckDiag(String basicKey, String inferKey) {
656 this.basicKey = basicKey;
657 this.inferKey = inferKey;
658 }
659 }
661 /**
662 * Main method applicability routine. Given a list of actual types A,
663 * a list of formal types F, determines whether the types in A are
664 * compatible (by method invocation conversion) with the types in F.
665 *
666 * Since this routine is shared between overload resolution and method
667 * type-inference, a (possibly empty) inference context is used to convert
668 * formal types to the corresponding 'undet' form ahead of a compatibility
669 * check so that constraints can be propagated and collected.
670 *
671 * Moreover, if one or more types in A is a deferred type, this routine uses
672 * DeferredAttr in order to perform deferred attribution. If one or more actual
673 * deferred types are stuck, they are placed in a queue and revisited later
674 * after the remainder of the arguments have been seen. If this is not sufficient
675 * to 'unstuck' the argument, a cyclic inference error is called out.
676 *
677 * A method check handler (see above) is used in order to report errors.
678 */
679 MethodCheck resolveMethodCheck = new MethodCheck() {
680 @Override
681 public void argumentsAcceptable(final Env<AttrContext> env,
682 DeferredAttrContext deferredAttrContext,
683 List<Type> argtypes,
684 List<Type> formals,
685 Warner warn) {
686 //should we expand formals?
687 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired();
689 //inference context used during this method check
690 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
692 Type varargsFormal = useVarargs ? formals.last() : null;
694 if (varargsFormal == null &&
695 argtypes.size() != formals.size()) {
696 report(MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
697 }
699 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
700 ResultInfo mresult = methodCheckResult(false, formals.head, deferredAttrContext, warn);
701 mresult.check(null, argtypes.head);
702 argtypes = argtypes.tail;
703 formals = formals.tail;
704 }
706 if (formals.head != varargsFormal) {
707 report(MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
708 }
710 if (useVarargs) {
711 //note: if applicability check is triggered by most specific test,
712 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
713 final Type elt = types.elemtype(varargsFormal);
714 ResultInfo mresult = methodCheckResult(true, elt, deferredAttrContext, warn);
715 while (argtypes.nonEmpty()) {
716 mresult.check(null, argtypes.head);
717 argtypes = argtypes.tail;
718 }
719 //check varargs element type accessibility
720 varargsAccessible(env, elt, inferenceContext);
721 }
722 }
724 private void report(MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
725 boolean inferDiag = inferenceContext != infer.emptyContext;
726 InapplicableMethodException ex = inferDiag ?
727 infer.inferenceException : inapplicableMethodException;
728 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) {
729 Object[] args2 = new Object[args.length + 1];
730 System.arraycopy(args, 0, args2, 1, args.length);
731 args2[0] = inferenceContext.inferenceVars();
732 args = args2;
733 }
734 throw ex.setMessage(inferDiag ? diag.inferKey : diag.basicKey, args);
735 }
737 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) {
738 if (inferenceContext.free(t)) {
739 inferenceContext.addFreeTypeListener(List.of(t), new FreeTypeListener() {
740 @Override
741 public void typesInferred(InferenceContext inferenceContext) {
742 varargsAccessible(env, inferenceContext.asInstType(t, types), inferenceContext);
743 }
744 });
745 } else {
746 if (!isAccessible(env, t)) {
747 Symbol location = env.enclClass.sym;
748 report(MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
749 }
750 }
751 }
753 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
754 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
755 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
756 MethodCheckDiag methodDiag = varargsCheck ?
757 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
759 @Override
760 public void report(DiagnosticPosition pos, JCDiagnostic details) {
761 report(methodDiag, deferredAttrContext.inferenceContext, details);
762 }
763 };
764 return new MethodResultInfo(to, checkContext);
765 }
766 };
768 /**
769 * Check context to be used during method applicability checks. A method check
770 * context might contain inference variables.
771 */
772 abstract class MethodCheckContext implements CheckContext {
774 boolean strict;
775 DeferredAttrContext deferredAttrContext;
776 Warner rsWarner;
778 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) {
779 this.strict = strict;
780 this.deferredAttrContext = deferredAttrContext;
781 this.rsWarner = rsWarner;
782 }
784 public boolean compatible(Type found, Type req, Warner warn) {
785 return strict ?
786 types.isSubtypeUnchecked(found, deferredAttrContext.inferenceContext.asFree(req, types), warn) :
787 types.isConvertible(found, deferredAttrContext.inferenceContext.asFree(req, types), warn);
788 }
790 public void report(DiagnosticPosition pos, JCDiagnostic details) {
791 throw inapplicableMethodException.setMessage(details);
792 }
794 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
795 return rsWarner;
796 }
798 public InferenceContext inferenceContext() {
799 return deferredAttrContext.inferenceContext;
800 }
802 public DeferredAttrContext deferredAttrContext() {
803 return deferredAttrContext;
804 }
805 }
807 /**
808 * ResultInfo class to be used during method applicability checks. Check
809 * for deferred types goes through special path.
810 */
811 class MethodResultInfo extends ResultInfo {
813 public MethodResultInfo(Type pt, CheckContext checkContext) {
814 attr.super(VAL, pt, checkContext);
815 }
817 @Override
818 protected Type check(DiagnosticPosition pos, Type found) {
819 if (found.hasTag(DEFERRED)) {
820 DeferredType dt = (DeferredType)found;
821 return dt.check(this);
822 } else {
823 return super.check(pos, chk.checkNonVoid(pos, types.capture(types.upperBound(found.baseType()))));
824 }
825 }
827 @Override
828 protected MethodResultInfo dup(Type newPt) {
829 return new MethodResultInfo(newPt, checkContext);
830 }
832 @Override
833 protected ResultInfo dup(CheckContext newContext) {
834 return new MethodResultInfo(pt, newContext);
835 }
836 }
838 public static class InapplicableMethodException extends RuntimeException {
839 private static final long serialVersionUID = 0;
841 JCDiagnostic diagnostic;
842 JCDiagnostic.Factory diags;
844 InapplicableMethodException(JCDiagnostic.Factory diags) {
845 this.diagnostic = null;
846 this.diags = diags;
847 }
848 InapplicableMethodException setMessage() {
849 return setMessage((JCDiagnostic)null);
850 }
851 InapplicableMethodException setMessage(String key) {
852 return setMessage(key != null ? diags.fragment(key) : null);
853 }
854 InapplicableMethodException setMessage(String key, Object... args) {
855 return setMessage(key != null ? diags.fragment(key, args) : null);
856 }
857 InapplicableMethodException setMessage(JCDiagnostic diag) {
858 this.diagnostic = diag;
859 return this;
860 }
862 public JCDiagnostic getDiagnostic() {
863 return diagnostic;
864 }
865 }
866 private final InapplicableMethodException inapplicableMethodException;
868 /* ***************************************************************************
869 * Symbol lookup
870 * the following naming conventions for arguments are used
871 *
872 * env is the environment where the symbol was mentioned
873 * site is the type of which the symbol is a member
874 * name is the symbol's name
875 * if no arguments are given
876 * argtypes are the value arguments, if we search for a method
877 *
878 * If no symbol was found, a ResolveError detailing the problem is returned.
879 ****************************************************************************/
881 /** Find field. Synthetic fields are always skipped.
882 * @param env The current environment.
883 * @param site The original type from where the selection takes place.
884 * @param name The name of the field.
885 * @param c The class to search for the field. This is always
886 * a superclass or implemented interface of site's class.
887 */
888 Symbol findField(Env<AttrContext> env,
889 Type site,
890 Name name,
891 TypeSymbol c) {
892 while (c.type.hasTag(TYPEVAR))
893 c = c.type.getUpperBound().tsym;
894 Symbol bestSoFar = varNotFound;
895 Symbol sym;
896 Scope.Entry e = c.members().lookup(name);
897 while (e.scope != null) {
898 if (e.sym.kind == VAR && (e.sym.flags_field & SYNTHETIC) == 0) {
899 return isAccessible(env, site, e.sym)
900 ? e.sym : new AccessError(env, site, e.sym);
901 }
902 e = e.next();
903 }
904 Type st = types.supertype(c.type);
905 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) {
906 sym = findField(env, site, name, st.tsym);
907 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
908 }
909 for (List<Type> l = types.interfaces(c.type);
910 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
911 l = l.tail) {
912 sym = findField(env, site, name, l.head.tsym);
913 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
914 sym.owner != bestSoFar.owner)
915 bestSoFar = new AmbiguityError(bestSoFar, sym);
916 else if (sym.kind < bestSoFar.kind)
917 bestSoFar = sym;
918 }
919 return bestSoFar;
920 }
922 /** Resolve a field identifier, throw a fatal error if not found.
923 * @param pos The position to use for error reporting.
924 * @param env The environment current at the method invocation.
925 * @param site The type of the qualifying expression, in which
926 * identifier is searched.
927 * @param name The identifier's name.
928 */
929 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
930 Type site, Name name) {
931 Symbol sym = findField(env, site, name, site.tsym);
932 if (sym.kind == VAR) return (VarSymbol)sym;
933 else throw new FatalError(
934 diags.fragment("fatal.err.cant.locate.field",
935 name));
936 }
938 /** Find unqualified variable or field with given name.
939 * Synthetic fields always skipped.
940 * @param env The current environment.
941 * @param name The name of the variable or field.
942 */
943 Symbol findVar(Env<AttrContext> env, Name name) {
944 Symbol bestSoFar = varNotFound;
945 Symbol sym;
946 Env<AttrContext> env1 = env;
947 boolean staticOnly = false;
948 while (env1.outer != null) {
949 if (isStatic(env1)) staticOnly = true;
950 Scope.Entry e = env1.info.scope.lookup(name);
951 while (e.scope != null &&
952 (e.sym.kind != VAR ||
953 (e.sym.flags_field & SYNTHETIC) != 0))
954 e = e.next();
955 sym = (e.scope != null)
956 ? e.sym
957 : findField(
958 env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
959 if (sym.exists()) {
960 if (staticOnly &&
961 sym.kind == VAR &&
962 sym.owner.kind == TYP &&
963 (sym.flags() & STATIC) == 0)
964 return new StaticError(sym);
965 else
966 return sym;
967 } else if (sym.kind < bestSoFar.kind) {
968 bestSoFar = sym;
969 }
971 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
972 env1 = env1.outer;
973 }
975 sym = findField(env, syms.predefClass.type, name, syms.predefClass);
976 if (sym.exists())
977 return sym;
978 if (bestSoFar.exists())
979 return bestSoFar;
981 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
982 for (; e.scope != null; e = e.next()) {
983 sym = e.sym;
984 Type origin = e.getOrigin().owner.type;
985 if (sym.kind == VAR) {
986 if (e.sym.owner.type != origin)
987 sym = sym.clone(e.getOrigin().owner);
988 return isAccessible(env, origin, sym)
989 ? sym : new AccessError(env, origin, sym);
990 }
991 }
993 Symbol origin = null;
994 e = env.toplevel.starImportScope.lookup(name);
995 for (; e.scope != null; e = e.next()) {
996 sym = e.sym;
997 if (sym.kind != VAR)
998 continue;
999 // invariant: sym.kind == VAR
1000 if (bestSoFar.kind < AMBIGUOUS && sym.owner != bestSoFar.owner)
1001 return new AmbiguityError(bestSoFar, sym);
1002 else if (bestSoFar.kind >= VAR) {
1003 origin = e.getOrigin().owner;
1004 bestSoFar = isAccessible(env, origin.type, sym)
1005 ? sym : new AccessError(env, origin.type, sym);
1006 }
1007 }
1008 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
1009 return bestSoFar.clone(origin);
1010 else
1011 return bestSoFar;
1012 }
1014 Warner noteWarner = new Warner();
1016 /** Select the best method for a call site among two choices.
1017 * @param env The current environment.
1018 * @param site The original type from where the
1019 * selection takes place.
1020 * @param argtypes The invocation's value arguments,
1021 * @param typeargtypes The invocation's type arguments,
1022 * @param sym Proposed new best match.
1023 * @param bestSoFar Previously found best match.
1024 * @param allowBoxing Allow boxing conversions of arguments.
1025 * @param useVarargs Box trailing arguments into an array for varargs.
1026 */
1027 @SuppressWarnings("fallthrough")
1028 Symbol selectBest(Env<AttrContext> env,
1029 Type site,
1030 List<Type> argtypes,
1031 List<Type> typeargtypes,
1032 Symbol sym,
1033 Symbol bestSoFar,
1034 boolean allowBoxing,
1035 boolean useVarargs,
1036 boolean operator) {
1037 if (sym.kind == ERR ||
1038 !sym.isInheritedIn(site.tsym, types) ||
1039 (useVarargs && (sym.flags() & VARARGS) == 0)) {
1040 return bestSoFar;
1041 }
1042 Assert.check(sym.kind < AMBIGUOUS);
1043 try {
1044 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes,
1045 allowBoxing, useVarargs, resolveMethodCheck, types.noWarnings);
1046 if (!operator)
1047 currentResolutionContext.addApplicableCandidate(sym, mt);
1048 } catch (InapplicableMethodException ex) {
1049 if (!operator)
1050 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic());
1051 switch (bestSoFar.kind) {
1052 case ABSENT_MTH:
1053 return new InapplicableSymbolError(currentResolutionContext);
1054 case WRONG_MTH:
1055 if (operator) return bestSoFar;
1056 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1057 default:
1058 return bestSoFar;
1059 }
1060 }
1061 if (!isAccessible(env, site, sym)) {
1062 return (bestSoFar.kind == ABSENT_MTH)
1063 ? new AccessError(env, site, sym)
1064 : bestSoFar;
1065 }
1066 return (bestSoFar.kind > AMBIGUOUS)
1067 ? sym
1068 : mostSpecific(argtypes, sym, bestSoFar, env, site,
1069 allowBoxing && operator, useVarargs);
1070 }
1072 /* Return the most specific of the two methods for a call,
1073 * given that both are accessible and applicable.
1074 * @param m1 A new candidate for most specific.
1075 * @param m2 The previous most specific candidate.
1076 * @param env The current environment.
1077 * @param site The original type from where the selection
1078 * takes place.
1079 * @param allowBoxing Allow boxing conversions of arguments.
1080 * @param useVarargs Box trailing arguments into an array for varargs.
1081 */
1082 Symbol mostSpecific(List<Type> argtypes, Symbol m1,
1083 Symbol m2,
1084 Env<AttrContext> env,
1085 final Type site,
1086 boolean allowBoxing,
1087 boolean useVarargs) {
1088 switch (m2.kind) {
1089 case MTH:
1090 if (m1 == m2) return m1;
1091 boolean m1SignatureMoreSpecific =
1092 signatureMoreSpecific(argtypes, env, site, m1, m2, allowBoxing, useVarargs);
1093 boolean m2SignatureMoreSpecific =
1094 signatureMoreSpecific(argtypes, env, site, m2, m1, allowBoxing, useVarargs);
1095 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
1096 Type mt1 = types.memberType(site, m1);
1097 Type mt2 = types.memberType(site, m2);
1098 if (!types.overrideEquivalent(mt1, mt2))
1099 return ambiguityError(m1, m2);
1101 // same signature; select (a) the non-bridge method, or
1102 // (b) the one that overrides the other, or (c) the concrete
1103 // one, or (d) merge both abstract signatures
1104 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
1105 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
1107 // if one overrides or hides the other, use it
1108 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
1109 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
1110 if (types.asSuper(m1Owner.type, m2Owner) != null &&
1111 ((m1.owner.flags_field & INTERFACE) == 0 ||
1112 (m2.owner.flags_field & INTERFACE) != 0) &&
1113 m1.overrides(m2, m1Owner, types, false))
1114 return m1;
1115 if (types.asSuper(m2Owner.type, m1Owner) != null &&
1116 ((m2.owner.flags_field & INTERFACE) == 0 ||
1117 (m1.owner.flags_field & INTERFACE) != 0) &&
1118 m2.overrides(m1, m2Owner, types, false))
1119 return m2;
1120 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
1121 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
1122 if (m1Abstract && !m2Abstract) return m2;
1123 if (m2Abstract && !m1Abstract) return m1;
1124 // both abstract or both concrete
1125 return ambiguityError(m1, m2);
1126 }
1127 if (m1SignatureMoreSpecific) return m1;
1128 if (m2SignatureMoreSpecific) return m2;
1129 return ambiguityError(m1, m2);
1130 case AMBIGUOUS:
1131 //check if m1 is more specific than all ambiguous methods in m2
1132 AmbiguityError e = (AmbiguityError)m2;
1133 for (Symbol s : e.ambiguousSyms) {
1134 if (mostSpecific(argtypes, m1, s, env, site, allowBoxing, useVarargs) != m1) {
1135 return e.addAmbiguousSymbol(m1);
1136 }
1137 }
1138 return m1;
1139 default:
1140 throw new AssertionError();
1141 }
1142 }
1143 //where
1144 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean allowBoxing, boolean useVarargs) {
1145 Symbol m12 = adjustVarargs(m1, m2, useVarargs);
1146 Symbol m22 = adjustVarargs(m2, m1, useVarargs);
1147 Type mtype1 = types.memberType(site, m12);
1148 Type mtype2 = types.memberType(site, m22);
1150 //check if invocation is more specific
1151 if (invocationMoreSpecific(env, site, m22, mtype1.getParameterTypes(), allowBoxing, useVarargs)) {
1152 return true;
1153 }
1155 //perform structural check
1157 List<Type> formals1 = mtype1.getParameterTypes();
1158 Type lastFormal1 = formals1.last();
1159 List<Type> formals2 = mtype2.getParameterTypes();
1160 Type lastFormal2 = formals2.last();
1161 ListBuffer<Type> newFormals = ListBuffer.lb();
1163 boolean hasStructuralPoly = false;
1164 for (Type actual : actuals) {
1165 //perform formal argument adaptation in case actuals > formals (varargs)
1166 Type f1 = formals1.isEmpty() ?
1167 lastFormal1 : formals1.head;
1168 Type f2 = formals2.isEmpty() ?
1169 lastFormal2 : formals2.head;
1171 //is this a structural actual argument?
1172 boolean isStructuralPoly = actual.hasTag(DEFERRED) &&
1173 (((DeferredType)actual).tree.hasTag(LAMBDA) ||
1174 ((DeferredType)actual).tree.hasTag(REFERENCE));
1176 Type newFormal = f1;
1178 if (isStructuralPoly) {
1179 //for structural arguments only - check that corresponding formals
1180 //are related - if so replace formal with <null>
1181 hasStructuralPoly = true;
1182 DeferredType dt = (DeferredType)actual;
1183 Type t1 = deferredAttr.new DeferredTypeMap(AttrMode.SPECULATIVE, m1, currentResolutionContext.step).apply(dt);
1184 Type t2 = deferredAttr.new DeferredTypeMap(AttrMode.SPECULATIVE, m2, currentResolutionContext.step).apply(dt);
1185 if (t1.isErroneous() || t2.isErroneous() || !isStructuralSubtype(t1, t2)) {
1186 //not structural subtypes - simply fail
1187 return false;
1188 } else {
1189 newFormal = syms.botType;
1190 }
1191 }
1193 newFormals.append(newFormal);
1194 if (newFormals.length() > mtype2.getParameterTypes().length()) {
1195 //expand m2's type so as to fit the new formal arity (varargs)
1196 m22.type = types.createMethodTypeWithParameters(m22.type, m22.type.getParameterTypes().append(f2));
1197 }
1199 formals1 = formals1.isEmpty() ? formals1 : formals1.tail;
1200 formals2 = formals2.isEmpty() ? formals2 : formals2.tail;
1201 }
1203 if (!hasStructuralPoly) {
1204 //if no structural actual was found, we're done
1205 return false;
1206 }
1207 //perform additional adaptation if actuals < formals (varargs)
1208 for (Type t : formals1) {
1209 newFormals.append(t);
1210 }
1211 //check if invocation (with tweaked args) is more specific
1212 return invocationMoreSpecific(env, site, m22, newFormals.toList(), allowBoxing, useVarargs);
1213 }
1214 //where
1215 private boolean invocationMoreSpecific(Env<AttrContext> env, Type site, Symbol m2, List<Type> argtypes1, boolean allowBoxing, boolean useVarargs) {
1216 MethodResolutionContext prevContext = currentResolutionContext;
1217 try {
1218 currentResolutionContext = new MethodResolutionContext();
1219 currentResolutionContext.step = allowBoxing ? BOX : BASIC;
1220 noteWarner.clear();
1221 Type mst = instantiate(env, site, m2, null,
1222 types.lowerBounds(argtypes1), null,
1223 allowBoxing, false, resolveMethodCheck, noteWarner);
1224 return mst != null &&
1225 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
1226 } finally {
1227 currentResolutionContext = prevContext;
1228 }
1229 }
1230 //where
1231 private Symbol adjustVarargs(Symbol to, Symbol from, boolean useVarargs) {
1232 List<Type> fromArgs = from.type.getParameterTypes();
1233 List<Type> toArgs = to.type.getParameterTypes();
1234 if (useVarargs &&
1235 (from.flags() & VARARGS) != 0 &&
1236 (to.flags() & VARARGS) != 0) {
1237 Type varargsTypeFrom = fromArgs.last();
1238 Type varargsTypeTo = toArgs.last();
1239 ListBuffer<Type> args = ListBuffer.lb();
1240 if (toArgs.length() < fromArgs.length()) {
1241 //if we are checking a varargs method 'from' against another varargs
1242 //method 'to' (where arity of 'to' < arity of 'from') then expand signature
1243 //of 'to' to 'fit' arity of 'from' (this means adding fake formals to 'to'
1244 //until 'to' signature has the same arity as 'from')
1245 while (fromArgs.head != varargsTypeFrom) {
1246 args.append(toArgs.head == varargsTypeTo ? types.elemtype(varargsTypeTo) : toArgs.head);
1247 fromArgs = fromArgs.tail;
1248 toArgs = toArgs.head == varargsTypeTo ?
1249 toArgs :
1250 toArgs.tail;
1251 }
1252 } else {
1253 //formal argument list is same as original list where last
1254 //argument (array type) is removed
1255 args.appendList(toArgs.reverse().tail.reverse());
1256 }
1257 //append varargs element type as last synthetic formal
1258 args.append(types.elemtype(varargsTypeTo));
1259 Type mtype = types.createMethodTypeWithParameters(to.type, args.toList());
1260 return new MethodSymbol(to.flags_field & ~VARARGS, to.name, mtype, to.owner);
1261 } else {
1262 return to;
1263 }
1264 }
1265 //where
1266 boolean isStructuralSubtype(Type s, Type t) {
1268 Type ret_s = types.findDescriptorType(s).getReturnType();
1269 Type ret_t = types.findDescriptorType(t).getReturnType();
1271 //covariant most specific check for function descriptor return type
1272 if (!types.isSubtype(ret_s, ret_t)) {
1273 return false;
1274 }
1276 List<Type> args_s = types.findDescriptorType(s).getParameterTypes();
1277 List<Type> args_t = types.findDescriptorType(t).getParameterTypes();
1279 //arity must be identical
1280 if (args_s.length() != args_t.length()) {
1281 return false;
1282 }
1284 //invariant most specific check for function descriptor parameter types
1285 if (!types.isSameTypes(args_t, args_s)) {
1286 return false;
1287 }
1289 return true;
1290 }
1291 //where
1292 Type mostSpecificReturnType(Type mt1, Type mt2) {
1293 Type rt1 = mt1.getReturnType();
1294 Type rt2 = mt2.getReturnType();
1296 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL)) {
1297 //if both are generic methods, adjust return type ahead of subtyping check
1298 rt1 = types.subst(rt1, mt1.getTypeArguments(), mt2.getTypeArguments());
1299 }
1300 //first use subtyping, then return type substitutability
1301 if (types.isSubtype(rt1, rt2)) {
1302 return mt1;
1303 } else if (types.isSubtype(rt2, rt1)) {
1304 return mt2;
1305 } else if (types.returnTypeSubstitutable(mt1, mt2)) {
1306 return mt1;
1307 } else if (types.returnTypeSubstitutable(mt2, mt1)) {
1308 return mt2;
1309 } else {
1310 return null;
1311 }
1312 }
1313 //where
1314 Symbol ambiguityError(Symbol m1, Symbol m2) {
1315 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
1316 return (m1.flags() & CLASH) == 0 ? m1 : m2;
1317 } else {
1318 return new AmbiguityError(m1, m2);
1319 }
1320 }
1322 Symbol findMethodInScope(Env<AttrContext> env,
1323 Type site,
1324 Name name,
1325 List<Type> argtypes,
1326 List<Type> typeargtypes,
1327 Scope sc,
1328 Symbol bestSoFar,
1329 boolean allowBoxing,
1330 boolean useVarargs,
1331 boolean operator,
1332 boolean abstractok) {
1333 for (Symbol s : sc.getElementsByName(name, new LookupFilter(abstractok))) {
1334 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s,
1335 bestSoFar, allowBoxing, useVarargs, operator);
1336 }
1337 return bestSoFar;
1338 }
1339 //where
1340 class LookupFilter implements Filter<Symbol> {
1342 boolean abstractOk;
1344 LookupFilter(boolean abstractOk) {
1345 this.abstractOk = abstractOk;
1346 }
1348 public boolean accepts(Symbol s) {
1349 long flags = s.flags();
1350 return s.kind == MTH &&
1351 (flags & SYNTHETIC) == 0 &&
1352 (abstractOk ||
1353 (flags & DEFAULT) != 0 ||
1354 (flags & ABSTRACT) == 0);
1355 }
1356 };
1358 /** Find best qualified method matching given name, type and value
1359 * arguments.
1360 * @param env The current environment.
1361 * @param site The original type from where the selection
1362 * takes place.
1363 * @param name The method's name.
1364 * @param argtypes The method's value arguments.
1365 * @param typeargtypes The method's type arguments
1366 * @param allowBoxing Allow boxing conversions of arguments.
1367 * @param useVarargs Box trailing arguments into an array for varargs.
1368 */
1369 Symbol findMethod(Env<AttrContext> env,
1370 Type site,
1371 Name name,
1372 List<Type> argtypes,
1373 List<Type> typeargtypes,
1374 boolean allowBoxing,
1375 boolean useVarargs,
1376 boolean operator) {
1377 Symbol bestSoFar = methodNotFound;
1378 bestSoFar = findMethod(env,
1379 site,
1380 name,
1381 argtypes,
1382 typeargtypes,
1383 site.tsym.type,
1384 bestSoFar,
1385 allowBoxing,
1386 useVarargs,
1387 operator);
1388 reportVerboseResolutionDiagnostic(env.tree.pos(), name, site, argtypes, typeargtypes, bestSoFar);
1389 return bestSoFar;
1390 }
1391 // where
1392 private Symbol findMethod(Env<AttrContext> env,
1393 Type site,
1394 Name name,
1395 List<Type> argtypes,
1396 List<Type> typeargtypes,
1397 Type intype,
1398 Symbol bestSoFar,
1399 boolean allowBoxing,
1400 boolean useVarargs,
1401 boolean operator) {
1402 @SuppressWarnings({"unchecked","rawtypes"})
1403 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() };
1404 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK;
1405 for (TypeSymbol s : superclasses(intype)) {
1406 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1407 s.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1408 if (name == names.init) return bestSoFar;
1409 iphase = (iphase == null) ? null : iphase.update(s, this);
1410 if (iphase != null) {
1411 for (Type itype : types.interfaces(s.type)) {
1412 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]);
1413 }
1414 }
1415 }
1417 Symbol concrete = bestSoFar.kind < ERR &&
1418 (bestSoFar.flags() & ABSTRACT) == 0 ?
1419 bestSoFar : methodNotFound;
1421 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) {
1422 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK && !allowDefaultMethods) break;
1423 //keep searching for abstract methods
1424 for (Type itype : itypes[iphase2.ordinal()]) {
1425 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure())
1426 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK &&
1427 (itype.tsym.flags() & DEFAULT) == 0) continue;
1428 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1429 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1430 if (concrete != bestSoFar &&
1431 concrete.kind < ERR && bestSoFar.kind < ERR &&
1432 types.isSubSignature(concrete.type, bestSoFar.type)) {
1433 //this is an hack - as javac does not do full membership checks
1434 //most specific ends up comparing abstract methods that might have
1435 //been implemented by some concrete method in a subclass and,
1436 //because of raw override, it is possible for an abstract method
1437 //to be more specific than the concrete method - so we need
1438 //to explicitly call that out (see CR 6178365)
1439 bestSoFar = concrete;
1440 }
1441 }
1442 }
1443 return bestSoFar;
1444 }
1446 enum InterfaceLookupPhase {
1447 ABSTRACT_OK() {
1448 @Override
1449 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1450 //We should not look for abstract methods if receiver is a concrete class
1451 //(as concrete classes are expected to implement all abstracts coming
1452 //from superinterfaces)
1453 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) {
1454 return this;
1455 } else if (rs.allowDefaultMethods) {
1456 return DEFAULT_OK;
1457 } else {
1458 return null;
1459 }
1460 }
1461 },
1462 DEFAULT_OK() {
1463 @Override
1464 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1465 return this;
1466 }
1467 };
1469 abstract InterfaceLookupPhase update(Symbol s, Resolve rs);
1470 }
1472 /**
1473 * Return an Iterable object to scan the superclasses of a given type.
1474 * It's crucial that the scan is done lazily, as we don't want to accidentally
1475 * access more supertypes than strictly needed (as this could trigger completion
1476 * errors if some of the not-needed supertypes are missing/ill-formed).
1477 */
1478 Iterable<TypeSymbol> superclasses(final Type intype) {
1479 return new Iterable<TypeSymbol>() {
1480 public Iterator<TypeSymbol> iterator() {
1481 return new Iterator<TypeSymbol>() {
1483 List<TypeSymbol> seen = List.nil();
1484 TypeSymbol currentSym = symbolFor(intype);
1485 TypeSymbol prevSym = null;
1487 public boolean hasNext() {
1488 if (currentSym == syms.noSymbol) {
1489 currentSym = symbolFor(types.supertype(prevSym.type));
1490 }
1491 return currentSym != null;
1492 }
1494 public TypeSymbol next() {
1495 prevSym = currentSym;
1496 currentSym = syms.noSymbol;
1497 Assert.check(prevSym != null || prevSym != syms.noSymbol);
1498 return prevSym;
1499 }
1501 public void remove() {
1502 throw new UnsupportedOperationException();
1503 }
1505 TypeSymbol symbolFor(Type t) {
1506 if (!t.hasTag(CLASS) &&
1507 !t.hasTag(TYPEVAR)) {
1508 return null;
1509 }
1510 while (t.hasTag(TYPEVAR))
1511 t = t.getUpperBound();
1512 if (seen.contains(t.tsym)) {
1513 //degenerate case in which we have a circular
1514 //class hierarchy - because of ill-formed classfiles
1515 return null;
1516 }
1517 seen = seen.prepend(t.tsym);
1518 return t.tsym;
1519 }
1520 };
1521 }
1522 };
1523 }
1525 /** Find unqualified method matching given name, type and value arguments.
1526 * @param env The current environment.
1527 * @param name The method's name.
1528 * @param argtypes The method's value arguments.
1529 * @param typeargtypes The method's type arguments.
1530 * @param allowBoxing Allow boxing conversions of arguments.
1531 * @param useVarargs Box trailing arguments into an array for varargs.
1532 */
1533 Symbol findFun(Env<AttrContext> env, Name name,
1534 List<Type> argtypes, List<Type> typeargtypes,
1535 boolean allowBoxing, boolean useVarargs) {
1536 Symbol bestSoFar = methodNotFound;
1537 Symbol sym;
1538 Env<AttrContext> env1 = env;
1539 boolean staticOnly = false;
1540 while (env1.outer != null) {
1541 if (isStatic(env1)) staticOnly = true;
1542 sym = findMethod(
1543 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
1544 allowBoxing, useVarargs, false);
1545 if (sym.exists()) {
1546 if (staticOnly &&
1547 sym.kind == MTH &&
1548 sym.owner.kind == TYP &&
1549 (sym.flags() & STATIC) == 0) return new StaticError(sym);
1550 else return sym;
1551 } else if (sym.kind < bestSoFar.kind) {
1552 bestSoFar = sym;
1553 }
1554 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1555 env1 = env1.outer;
1556 }
1558 sym = findMethod(env, syms.predefClass.type, name, argtypes,
1559 typeargtypes, allowBoxing, useVarargs, false);
1560 if (sym.exists())
1561 return sym;
1563 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
1564 for (; e.scope != null; e = e.next()) {
1565 sym = e.sym;
1566 Type origin = e.getOrigin().owner.type;
1567 if (sym.kind == MTH) {
1568 if (e.sym.owner.type != origin)
1569 sym = sym.clone(e.getOrigin().owner);
1570 if (!isAccessible(env, origin, sym))
1571 sym = new AccessError(env, origin, sym);
1572 bestSoFar = selectBest(env, origin,
1573 argtypes, typeargtypes,
1574 sym, bestSoFar,
1575 allowBoxing, useVarargs, false);
1576 }
1577 }
1578 if (bestSoFar.exists())
1579 return bestSoFar;
1581 e = env.toplevel.starImportScope.lookup(name);
1582 for (; e.scope != null; e = e.next()) {
1583 sym = e.sym;
1584 Type origin = e.getOrigin().owner.type;
1585 if (sym.kind == MTH) {
1586 if (e.sym.owner.type != origin)
1587 sym = sym.clone(e.getOrigin().owner);
1588 if (!isAccessible(env, origin, sym))
1589 sym = new AccessError(env, origin, sym);
1590 bestSoFar = selectBest(env, origin,
1591 argtypes, typeargtypes,
1592 sym, bestSoFar,
1593 allowBoxing, useVarargs, false);
1594 }
1595 }
1596 return bestSoFar;
1597 }
1599 /** Load toplevel or member class with given fully qualified name and
1600 * verify that it is accessible.
1601 * @param env The current environment.
1602 * @param name The fully qualified name of the class to be loaded.
1603 */
1604 Symbol loadClass(Env<AttrContext> env, Name name) {
1605 try {
1606 ClassSymbol c = reader.loadClass(name);
1607 return isAccessible(env, c) ? c : new AccessError(c);
1608 } catch (ClassReader.BadClassFile err) {
1609 throw err;
1610 } catch (CompletionFailure ex) {
1611 return typeNotFound;
1612 }
1613 }
1615 /** Find qualified member type.
1616 * @param env The current environment.
1617 * @param site The original type from where the selection takes
1618 * place.
1619 * @param name The type's name.
1620 * @param c The class to search for the member type. This is
1621 * always a superclass or implemented interface of
1622 * site's class.
1623 */
1624 Symbol findMemberType(Env<AttrContext> env,
1625 Type site,
1626 Name name,
1627 TypeSymbol c) {
1628 Symbol bestSoFar = typeNotFound;
1629 Symbol sym;
1630 Scope.Entry e = c.members().lookup(name);
1631 while (e.scope != null) {
1632 if (e.sym.kind == TYP) {
1633 return isAccessible(env, site, e.sym)
1634 ? e.sym
1635 : new AccessError(env, site, e.sym);
1636 }
1637 e = e.next();
1638 }
1639 Type st = types.supertype(c.type);
1640 if (st != null && st.hasTag(CLASS)) {
1641 sym = findMemberType(env, site, name, st.tsym);
1642 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1643 }
1644 for (List<Type> l = types.interfaces(c.type);
1645 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1646 l = l.tail) {
1647 sym = findMemberType(env, site, name, l.head.tsym);
1648 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1649 sym.owner != bestSoFar.owner)
1650 bestSoFar = new AmbiguityError(bestSoFar, sym);
1651 else if (sym.kind < bestSoFar.kind)
1652 bestSoFar = sym;
1653 }
1654 return bestSoFar;
1655 }
1657 /** Find a global type in given scope and load corresponding class.
1658 * @param env The current environment.
1659 * @param scope The scope in which to look for the type.
1660 * @param name The type's name.
1661 */
1662 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) {
1663 Symbol bestSoFar = typeNotFound;
1664 for (Scope.Entry e = scope.lookup(name); e.scope != null; e = e.next()) {
1665 Symbol sym = loadClass(env, e.sym.flatName());
1666 if (bestSoFar.kind == TYP && sym.kind == TYP &&
1667 bestSoFar != sym)
1668 return new AmbiguityError(bestSoFar, sym);
1669 else if (sym.kind < bestSoFar.kind)
1670 bestSoFar = sym;
1671 }
1672 return bestSoFar;
1673 }
1675 /** Find an unqualified type symbol.
1676 * @param env The current environment.
1677 * @param name The type's name.
1678 */
1679 Symbol findType(Env<AttrContext> env, Name name) {
1680 Symbol bestSoFar = typeNotFound;
1681 Symbol sym;
1682 boolean staticOnly = false;
1683 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
1684 if (isStatic(env1)) staticOnly = true;
1685 for (Scope.Entry e = env1.info.scope.lookup(name);
1686 e.scope != null;
1687 e = e.next()) {
1688 if (e.sym.kind == TYP) {
1689 if (staticOnly &&
1690 e.sym.type.hasTag(TYPEVAR) &&
1691 e.sym.owner.kind == TYP) return new StaticError(e.sym);
1692 return e.sym;
1693 }
1694 }
1696 sym = findMemberType(env1, env1.enclClass.sym.type, name,
1697 env1.enclClass.sym);
1698 if (staticOnly && sym.kind == TYP &&
1699 sym.type.hasTag(CLASS) &&
1700 sym.type.getEnclosingType().hasTag(CLASS) &&
1701 env1.enclClass.sym.type.isParameterized() &&
1702 sym.type.getEnclosingType().isParameterized())
1703 return new StaticError(sym);
1704 else if (sym.exists()) return sym;
1705 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1707 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
1708 if ((encl.sym.flags() & STATIC) != 0)
1709 staticOnly = true;
1710 }
1712 if (!env.tree.hasTag(IMPORT)) {
1713 sym = findGlobalType(env, env.toplevel.namedImportScope, name);
1714 if (sym.exists()) return sym;
1715 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1717 sym = findGlobalType(env, env.toplevel.packge.members(), name);
1718 if (sym.exists()) return sym;
1719 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1721 sym = findGlobalType(env, env.toplevel.starImportScope, name);
1722 if (sym.exists()) return sym;
1723 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1724 }
1726 return bestSoFar;
1727 }
1729 /** Find an unqualified identifier which matches a specified kind set.
1730 * @param env The current environment.
1731 * @param name The identifier's name.
1732 * @param kind Indicates the possible symbol kinds
1733 * (a subset of VAL, TYP, PCK).
1734 */
1735 Symbol findIdent(Env<AttrContext> env, Name name, int kind) {
1736 Symbol bestSoFar = typeNotFound;
1737 Symbol sym;
1739 if ((kind & VAR) != 0) {
1740 sym = findVar(env, name);
1741 if (sym.exists()) return sym;
1742 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1743 }
1745 if ((kind & TYP) != 0) {
1746 sym = findType(env, name);
1747 if (sym.kind==TYP) {
1748 reportDependence(env.enclClass.sym, sym);
1749 }
1750 if (sym.exists()) return sym;
1751 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1752 }
1754 if ((kind & PCK) != 0) return reader.enterPackage(name);
1755 else return bestSoFar;
1756 }
1758 /** Report dependencies.
1759 * @param from The enclosing class sym
1760 * @param to The found identifier that the class depends on.
1761 */
1762 public void reportDependence(Symbol from, Symbol to) {
1763 // Override if you want to collect the reported dependencies.
1764 }
1766 /** Find an identifier in a package which matches a specified kind set.
1767 * @param env The current environment.
1768 * @param name The identifier's name.
1769 * @param kind Indicates the possible symbol kinds
1770 * (a nonempty subset of TYP, PCK).
1771 */
1772 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
1773 Name name, int kind) {
1774 Name fullname = TypeSymbol.formFullName(name, pck);
1775 Symbol bestSoFar = typeNotFound;
1776 PackageSymbol pack = null;
1777 if ((kind & PCK) != 0) {
1778 pack = reader.enterPackage(fullname);
1779 if (pack.exists()) return pack;
1780 }
1781 if ((kind & TYP) != 0) {
1782 Symbol sym = loadClass(env, fullname);
1783 if (sym.exists()) {
1784 // don't allow programs to use flatnames
1785 if (name == sym.name) return sym;
1786 }
1787 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1788 }
1789 return (pack != null) ? pack : bestSoFar;
1790 }
1792 /** Find an identifier among the members of a given type `site'.
1793 * @param env The current environment.
1794 * @param site The type containing the symbol to be found.
1795 * @param name The identifier's name.
1796 * @param kind Indicates the possible symbol kinds
1797 * (a subset of VAL, TYP).
1798 */
1799 Symbol findIdentInType(Env<AttrContext> env, Type site,
1800 Name name, int kind) {
1801 Symbol bestSoFar = typeNotFound;
1802 Symbol sym;
1803 if ((kind & VAR) != 0) {
1804 sym = findField(env, site, name, site.tsym);
1805 if (sym.exists()) return sym;
1806 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1807 }
1809 if ((kind & TYP) != 0) {
1810 sym = findMemberType(env, site, name, site.tsym);
1811 if (sym.exists()) return sym;
1812 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1813 }
1814 return bestSoFar;
1815 }
1817 /* ***************************************************************************
1818 * Access checking
1819 * The following methods convert ResolveErrors to ErrorSymbols, issuing
1820 * an error message in the process
1821 ****************************************************************************/
1823 /** If `sym' is a bad symbol: report error and return errSymbol
1824 * else pass through unchanged,
1825 * additional arguments duplicate what has been used in trying to find the
1826 * symbol {@literal (--> flyweight pattern)}. This improves performance since we
1827 * expect misses to happen frequently.
1828 *
1829 * @param sym The symbol that was found, or a ResolveError.
1830 * @param pos The position to use for error reporting.
1831 * @param location The symbol the served as a context for this lookup
1832 * @param site The original type from where the selection took place.
1833 * @param name The symbol's name.
1834 * @param qualified Did we get here through a qualified expression resolution?
1835 * @param argtypes The invocation's value arguments,
1836 * if we looked for a method.
1837 * @param typeargtypes The invocation's type arguments,
1838 * if we looked for a method.
1839 * @param logResolveHelper helper class used to log resolve errors
1840 */
1841 Symbol accessInternal(Symbol sym,
1842 DiagnosticPosition pos,
1843 Symbol location,
1844 Type site,
1845 Name name,
1846 boolean qualified,
1847 List<Type> argtypes,
1848 List<Type> typeargtypes,
1849 LogResolveHelper logResolveHelper) {
1850 if (sym.kind >= AMBIGUOUS) {
1851 ResolveError errSym = (ResolveError)sym;
1852 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
1853 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes);
1854 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) {
1855 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
1856 }
1857 }
1858 return sym;
1859 }
1861 /**
1862 * Variant of the generalized access routine, to be used for generating method
1863 * resolution diagnostics
1864 */
1865 Symbol accessMethod(Symbol sym,
1866 DiagnosticPosition pos,
1867 Symbol location,
1868 Type site,
1869 Name name,
1870 boolean qualified,
1871 List<Type> argtypes,
1872 List<Type> typeargtypes) {
1873 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper);
1874 }
1876 /** Same as original accessMethod(), but without location.
1877 */
1878 Symbol accessMethod(Symbol sym,
1879 DiagnosticPosition pos,
1880 Type site,
1881 Name name,
1882 boolean qualified,
1883 List<Type> argtypes,
1884 List<Type> typeargtypes) {
1885 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
1886 }
1888 /**
1889 * Variant of the generalized access routine, to be used for generating variable,
1890 * type resolution diagnostics
1891 */
1892 Symbol accessBase(Symbol sym,
1893 DiagnosticPosition pos,
1894 Symbol location,
1895 Type site,
1896 Name name,
1897 boolean qualified) {
1898 return accessInternal(sym, pos, location, site, name, qualified, List.<Type>nil(), null, basicLogResolveHelper);
1899 }
1901 /** Same as original accessBase(), but without location.
1902 */
1903 Symbol accessBase(Symbol sym,
1904 DiagnosticPosition pos,
1905 Type site,
1906 Name name,
1907 boolean qualified) {
1908 return accessBase(sym, pos, site.tsym, site, name, qualified);
1909 }
1911 interface LogResolveHelper {
1912 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes);
1913 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes);
1914 }
1916 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() {
1917 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
1918 return !site.isErroneous();
1919 }
1920 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
1921 return argtypes;
1922 }
1923 };
1925 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() {
1926 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
1927 return !site.isErroneous() &&
1928 !Type.isErroneous(argtypes) &&
1929 (typeargtypes == null || !Type.isErroneous(typeargtypes));
1930 }
1931 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
1932 return (syms.operatorNames.contains(name)) ?
1933 argtypes :
1934 Type.map(argtypes, new ResolveDeferredRecoveryMap(accessedSym));
1935 }
1937 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap {
1939 public ResolveDeferredRecoveryMap(Symbol msym) {
1940 deferredAttr.super(AttrMode.SPECULATIVE, msym, currentResolutionContext.step);
1941 }
1943 @Override
1944 protected Type typeOf(DeferredType dt) {
1945 Type res = super.typeOf(dt);
1946 if (!res.isErroneous()) {
1947 switch (TreeInfo.skipParens(dt.tree).getTag()) {
1948 case LAMBDA:
1949 case REFERENCE:
1950 return dt;
1951 case CONDEXPR:
1952 return res == Type.recoveryType ?
1953 dt : res;
1954 }
1955 }
1956 return res;
1957 }
1958 }
1959 };
1961 /** Check that sym is not an abstract method.
1962 */
1963 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
1964 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0)
1965 log.error(pos, "abstract.cant.be.accessed.directly",
1966 kindName(sym), sym, sym.location());
1967 }
1969 /* ***************************************************************************
1970 * Debugging
1971 ****************************************************************************/
1973 /** print all scopes starting with scope s and proceeding outwards.
1974 * used for debugging.
1975 */
1976 public void printscopes(Scope s) {
1977 while (s != null) {
1978 if (s.owner != null)
1979 System.err.print(s.owner + ": ");
1980 for (Scope.Entry e = s.elems; e != null; e = e.sibling) {
1981 if ((e.sym.flags() & ABSTRACT) != 0)
1982 System.err.print("abstract ");
1983 System.err.print(e.sym + " ");
1984 }
1985 System.err.println();
1986 s = s.next;
1987 }
1988 }
1990 void printscopes(Env<AttrContext> env) {
1991 while (env.outer != null) {
1992 System.err.println("------------------------------");
1993 printscopes(env.info.scope);
1994 env = env.outer;
1995 }
1996 }
1998 public void printscopes(Type t) {
1999 while (t.hasTag(CLASS)) {
2000 printscopes(t.tsym.members());
2001 t = types.supertype(t);
2002 }
2003 }
2005 /* ***************************************************************************
2006 * Name resolution
2007 * Naming conventions are as for symbol lookup
2008 * Unlike the find... methods these methods will report access errors
2009 ****************************************************************************/
2011 /** Resolve an unqualified (non-method) identifier.
2012 * @param pos The position to use for error reporting.
2013 * @param env The environment current at the identifier use.
2014 * @param name The identifier's name.
2015 * @param kind The set of admissible symbol kinds for the identifier.
2016 */
2017 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
2018 Name name, int kind) {
2019 return accessBase(
2020 findIdent(env, name, kind),
2021 pos, env.enclClass.sym.type, name, false);
2022 }
2024 /** Resolve an unqualified method identifier.
2025 * @param pos The position to use for error reporting.
2026 * @param env The environment current at the method invocation.
2027 * @param name The identifier's name.
2028 * @param argtypes The types of the invocation's value arguments.
2029 * @param typeargtypes The types of the invocation's type arguments.
2030 */
2031 Symbol resolveMethod(DiagnosticPosition pos,
2032 Env<AttrContext> env,
2033 Name name,
2034 List<Type> argtypes,
2035 List<Type> typeargtypes) {
2036 return lookupMethod(env, pos, env.enclClass.sym, new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) {
2037 @Override
2038 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2039 return findFun(env, name, argtypes, typeargtypes,
2040 phase.isBoxingRequired(),
2041 phase.isVarargsRequired());
2042 }
2043 });
2044 }
2046 /** Resolve a qualified method identifier
2047 * @param pos The position to use for error reporting.
2048 * @param env The environment current at the method invocation.
2049 * @param site The type of the qualifying expression, in which
2050 * identifier is searched.
2051 * @param name The identifier's name.
2052 * @param argtypes The types of the invocation's value arguments.
2053 * @param typeargtypes The types of the invocation's type arguments.
2054 */
2055 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2056 Type site, Name name, List<Type> argtypes,
2057 List<Type> typeargtypes) {
2058 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
2059 }
2060 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2061 Symbol location, Type site, Name name, List<Type> argtypes,
2062 List<Type> typeargtypes) {
2063 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
2064 }
2065 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
2066 DiagnosticPosition pos, Env<AttrContext> env,
2067 Symbol location, Type site, Name name, List<Type> argtypes,
2068 List<Type> typeargtypes) {
2069 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) {
2070 @Override
2071 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2072 return findMethod(env, site, name, argtypes, typeargtypes,
2073 phase.isBoxingRequired(),
2074 phase.isVarargsRequired(), false);
2075 }
2076 @Override
2077 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2078 if (sym.kind >= AMBIGUOUS) {
2079 sym = super.access(env, pos, location, sym);
2080 } else if (allowMethodHandles) {
2081 MethodSymbol msym = (MethodSymbol)sym;
2082 if (msym.isSignaturePolymorphic(types)) {
2083 return findPolymorphicSignatureInstance(env, sym, argtypes);
2084 }
2085 }
2086 return sym;
2087 }
2088 });
2089 }
2091 /** Find or create an implicit method of exactly the given type (after erasure).
2092 * Searches in a side table, not the main scope of the site.
2093 * This emulates the lookup process required by JSR 292 in JVM.
2094 * @param env Attribution environment
2095 * @param spMethod signature polymorphic method - i.e. MH.invokeExact
2096 * @param argtypes The required argument types
2097 */
2098 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env,
2099 final Symbol spMethod,
2100 List<Type> argtypes) {
2101 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
2102 (MethodSymbol)spMethod, currentResolutionContext, argtypes);
2103 for (Symbol sym : polymorphicSignatureScope.getElementsByName(spMethod.name)) {
2104 if (types.isSameType(mtype, sym.type)) {
2105 return sym;
2106 }
2107 }
2109 // create the desired method
2110 long flags = ABSTRACT | HYPOTHETICAL | spMethod.flags() & Flags.AccessFlags;
2111 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) {
2112 @Override
2113 public Symbol baseSymbol() {
2114 return spMethod;
2115 }
2116 };
2117 polymorphicSignatureScope.enter(msym);
2118 return msym;
2119 }
2121 /** Resolve a qualified method identifier, throw a fatal error if not
2122 * found.
2123 * @param pos The position to use for error reporting.
2124 * @param env The environment current at the method invocation.
2125 * @param site The type of the qualifying expression, in which
2126 * identifier is searched.
2127 * @param name The identifier's name.
2128 * @param argtypes The types of the invocation's value arguments.
2129 * @param typeargtypes The types of the invocation's type arguments.
2130 */
2131 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
2132 Type site, Name name,
2133 List<Type> argtypes,
2134 List<Type> typeargtypes) {
2135 MethodResolutionContext resolveContext = new MethodResolutionContext();
2136 resolveContext.internalResolution = true;
2137 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
2138 site, name, argtypes, typeargtypes);
2139 if (sym.kind == MTH) return (MethodSymbol)sym;
2140 else throw new FatalError(
2141 diags.fragment("fatal.err.cant.locate.meth",
2142 name));
2143 }
2145 /** Resolve constructor.
2146 * @param pos The position to use for error reporting.
2147 * @param env The environment current at the constructor invocation.
2148 * @param site The type of class for which a constructor is searched.
2149 * @param argtypes The types of the constructor invocation's value
2150 * arguments.
2151 * @param typeargtypes The types of the constructor invocation's type
2152 * arguments.
2153 */
2154 Symbol resolveConstructor(DiagnosticPosition pos,
2155 Env<AttrContext> env,
2156 Type site,
2157 List<Type> argtypes,
2158 List<Type> typeargtypes) {
2159 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
2160 }
2162 private Symbol resolveConstructor(MethodResolutionContext resolveContext,
2163 final DiagnosticPosition pos,
2164 Env<AttrContext> env,
2165 Type site,
2166 List<Type> argtypes,
2167 List<Type> typeargtypes) {
2168 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2169 @Override
2170 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2171 return findConstructor(pos, env, site, argtypes, typeargtypes,
2172 phase.isBoxingRequired(),
2173 phase.isVarargsRequired());
2174 }
2175 });
2176 }
2178 /** Resolve a constructor, throw a fatal error if not found.
2179 * @param pos The position to use for error reporting.
2180 * @param env The environment current at the method invocation.
2181 * @param site The type to be constructed.
2182 * @param argtypes The types of the invocation's value arguments.
2183 * @param typeargtypes The types of the invocation's type arguments.
2184 */
2185 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2186 Type site,
2187 List<Type> argtypes,
2188 List<Type> typeargtypes) {
2189 MethodResolutionContext resolveContext = new MethodResolutionContext();
2190 resolveContext.internalResolution = true;
2191 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
2192 if (sym.kind == MTH) return (MethodSymbol)sym;
2193 else throw new FatalError(
2194 diags.fragment("fatal.err.cant.locate.ctor", site));
2195 }
2197 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2198 Type site, List<Type> argtypes,
2199 List<Type> typeargtypes,
2200 boolean allowBoxing,
2201 boolean useVarargs) {
2202 Symbol sym = findMethod(env, site,
2203 names.init, argtypes,
2204 typeargtypes, allowBoxing,
2205 useVarargs, false);
2206 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2207 return sym;
2208 }
2210 /** Resolve constructor using diamond inference.
2211 * @param pos The position to use for error reporting.
2212 * @param env The environment current at the constructor invocation.
2213 * @param site The type of class for which a constructor is searched.
2214 * The scope of this class has been touched in attribution.
2215 * @param argtypes The types of the constructor invocation's value
2216 * arguments.
2217 * @param typeargtypes The types of the constructor invocation's type
2218 * arguments.
2219 */
2220 Symbol resolveDiamond(DiagnosticPosition pos,
2221 Env<AttrContext> env,
2222 Type site,
2223 List<Type> argtypes,
2224 List<Type> typeargtypes) {
2225 return lookupMethod(env, pos, site.tsym, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2226 @Override
2227 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2228 return findDiamond(env, site, argtypes, typeargtypes,
2229 phase.isBoxingRequired(),
2230 phase.isVarargsRequired());
2231 }
2232 @Override
2233 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2234 if (sym.kind >= AMBIGUOUS) {
2235 final JCDiagnostic details = sym.kind == WRONG_MTH ?
2236 ((InapplicableSymbolError)sym).errCandidate().details :
2237 null;
2238 sym = new InapplicableSymbolError(sym.kind, "diamondError", currentResolutionContext) {
2239 @Override
2240 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
2241 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
2242 String key = details == null ?
2243 "cant.apply.diamond" :
2244 "cant.apply.diamond.1";
2245 return diags.create(dkind, log.currentSource(), pos, key,
2246 diags.fragment("diamond", site.tsym), details);
2247 }
2248 };
2249 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes);
2250 env.info.pendingResolutionPhase = currentResolutionContext.step;
2251 }
2252 return sym;
2253 }
2254 });
2255 }
2257 /** This method scans all the constructor symbol in a given class scope -
2258 * assuming that the original scope contains a constructor of the kind:
2259 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
2260 * a method check is executed against the modified constructor type:
2261 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond
2262 * inference. The inferred return type of the synthetic constructor IS
2263 * the inferred type for the diamond operator.
2264 */
2265 private Symbol findDiamond(Env<AttrContext> env,
2266 Type site,
2267 List<Type> argtypes,
2268 List<Type> typeargtypes,
2269 boolean allowBoxing,
2270 boolean useVarargs) {
2271 Symbol bestSoFar = methodNotFound;
2272 for (Scope.Entry e = site.tsym.members().lookup(names.init);
2273 e.scope != null;
2274 e = e.next()) {
2275 final Symbol sym = e.sym;
2276 //- System.out.println(" e " + e.sym);
2277 if (sym.kind == MTH &&
2278 (sym.flags_field & SYNTHETIC) == 0) {
2279 List<Type> oldParams = e.sym.type.hasTag(FORALL) ?
2280 ((ForAll)sym.type).tvars :
2281 List.<Type>nil();
2282 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
2283 types.createMethodTypeWithReturn(sym.type.asMethodType(), site));
2284 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) {
2285 @Override
2286 public Symbol baseSymbol() {
2287 return sym;
2288 }
2289 };
2290 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
2291 newConstr,
2292 bestSoFar,
2293 allowBoxing,
2294 useVarargs,
2295 false);
2296 }
2297 }
2298 return bestSoFar;
2299 }
2303 /** Resolve operator.
2304 * @param pos The position to use for error reporting.
2305 * @param optag The tag of the operation tree.
2306 * @param env The environment current at the operation.
2307 * @param argtypes The types of the operands.
2308 */
2309 Symbol resolveOperator(DiagnosticPosition pos, JCTree.Tag optag,
2310 Env<AttrContext> env, List<Type> argtypes) {
2311 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2312 try {
2313 currentResolutionContext = new MethodResolutionContext();
2314 Name name = treeinfo.operatorName(optag);
2315 env.info.pendingResolutionPhase = currentResolutionContext.step = BASIC;
2316 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
2317 null, false, false, true);
2318 if (boxingEnabled && sym.kind >= WRONG_MTHS)
2319 env.info.pendingResolutionPhase = currentResolutionContext.step = BOX;
2320 sym = findMethod(env, syms.predefClass.type, name, argtypes,
2321 null, true, false, true);
2322 return accessMethod(sym, pos, env.enclClass.sym.type, name,
2323 false, argtypes, null);
2324 }
2325 finally {
2326 currentResolutionContext = prevResolutionContext;
2327 }
2328 }
2330 /** Resolve operator.
2331 * @param pos The position to use for error reporting.
2332 * @param optag The tag of the operation tree.
2333 * @param env The environment current at the operation.
2334 * @param arg The type of the operand.
2335 */
2336 Symbol resolveUnaryOperator(DiagnosticPosition pos, JCTree.Tag optag, Env<AttrContext> env, Type arg) {
2337 return resolveOperator(pos, optag, env, List.of(arg));
2338 }
2340 /** Resolve binary operator.
2341 * @param pos The position to use for error reporting.
2342 * @param optag The tag of the operation tree.
2343 * @param env The environment current at the operation.
2344 * @param left The types of the left operand.
2345 * @param right The types of the right operand.
2346 */
2347 Symbol resolveBinaryOperator(DiagnosticPosition pos,
2348 JCTree.Tag optag,
2349 Env<AttrContext> env,
2350 Type left,
2351 Type right) {
2352 return resolveOperator(pos, optag, env, List.of(left, right));
2353 }
2355 /**
2356 * Resolution of member references is typically done as a single
2357 * overload resolution step, where the argument types A are inferred from
2358 * the target functional descriptor.
2359 *
2360 * If the member reference is a method reference with a type qualifier,
2361 * a two-step lookup process is performed. The first step uses the
2362 * expected argument list A, while the second step discards the first
2363 * type from A (which is treated as a receiver type).
2364 *
2365 * There are two cases in which inference is performed: (i) if the member
2366 * reference is a constructor reference and the qualifier type is raw - in
2367 * which case diamond inference is used to infer a parameterization for the
2368 * type qualifier; (ii) if the member reference is an unbound reference
2369 * where the type qualifier is raw - in that case, during the unbound lookup
2370 * the receiver argument type is used to infer an instantiation for the raw
2371 * qualifier type.
2372 *
2373 * When a multi-step resolution process is exploited, it is an error
2374 * if two candidates are found (ambiguity).
2375 *
2376 * This routine returns a pair (T,S), where S is the member reference symbol,
2377 * and T is the type of the class in which S is defined. This is necessary as
2378 * the type T might be dynamically inferred (i.e. if constructor reference
2379 * has a raw qualifier).
2380 */
2381 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(DiagnosticPosition pos,
2382 Env<AttrContext> env,
2383 JCMemberReference referenceTree,
2384 Type site,
2385 Name name, List<Type> argtypes,
2386 List<Type> typeargtypes,
2387 boolean boxingAllowed) {
2388 MethodResolutionPhase maxPhase = boxingAllowed ? VARARITY : BASIC;
2390 ReferenceLookupHelper boundLookupHelper;
2391 if (!name.equals(names.init)) {
2392 //method reference
2393 boundLookupHelper =
2394 new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2395 } else if (site.hasTag(ARRAY)) {
2396 //array constructor reference
2397 boundLookupHelper =
2398 new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2399 } else {
2400 //class constructor reference
2401 boundLookupHelper =
2402 new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2403 }
2405 //step 1 - bound lookup
2406 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup());
2407 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(), site.tsym, boundLookupHelper);
2409 //step 2 - unbound lookup
2410 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup();
2411 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup());
2412 Symbol unboundSym = lookupMethod(unboundEnv, env.tree.pos(), site.tsym, unboundLookupHelper);
2414 //merge results
2415 Pair<Symbol, ReferenceLookupHelper> res;
2416 if (unboundSym.kind != MTH) {
2417 res = new Pair<Symbol, ReferenceLookupHelper>(boundSym, boundLookupHelper);
2418 env.info.pendingResolutionPhase = boundEnv.info.pendingResolutionPhase;
2419 } else if (boundSym.kind == MTH) {
2420 res = new Pair<Symbol, ReferenceLookupHelper>(ambiguityError(boundSym, unboundSym), boundLookupHelper);
2421 env.info.pendingResolutionPhase = boundEnv.info.pendingResolutionPhase;
2422 } else {
2423 res = new Pair<Symbol, ReferenceLookupHelper>(unboundSym, unboundLookupHelper);
2424 env.info.pendingResolutionPhase = unboundEnv.info.pendingResolutionPhase;
2425 }
2427 return res;
2428 }
2430 /**
2431 * Helper for defining custom method-like lookup logic; a lookup helper
2432 * provides hooks for (i) the actual lookup logic and (ii) accessing the
2433 * lookup result (this step might result in compiler diagnostics to be generated)
2434 */
2435 abstract class LookupHelper {
2437 /** name of the symbol to lookup */
2438 Name name;
2440 /** location in which the lookup takes place */
2441 Type site;
2443 /** actual types used during the lookup */
2444 List<Type> argtypes;
2446 /** type arguments used during the lookup */
2447 List<Type> typeargtypes;
2449 /** Max overload resolution phase handled by this helper */
2450 MethodResolutionPhase maxPhase;
2452 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2453 this.name = name;
2454 this.site = site;
2455 this.argtypes = argtypes;
2456 this.typeargtypes = typeargtypes;
2457 this.maxPhase = maxPhase;
2458 }
2460 /**
2461 * Should lookup stop at given phase with given result
2462 */
2463 protected boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
2464 return phase.ordinal() > maxPhase.ordinal() ||
2465 sym.kind < ERRONEOUS || sym.kind == AMBIGUOUS;
2466 }
2468 /**
2469 * Search for a symbol under a given overload resolution phase - this method
2470 * is usually called several times, once per each overload resolution phase
2471 */
2472 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase);
2474 /**
2475 * Validate the result of the lookup
2476 */
2477 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym);
2478 }
2480 abstract class BasicLookupHelper extends LookupHelper {
2482 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) {
2483 super(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY);
2484 }
2486 @Override
2487 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2488 if (sym.kind == AMBIGUOUS) {
2489 AmbiguityError a_err = (AmbiguityError)sym;
2490 sym = a_err.mergeAbstracts(site);
2491 }
2492 if (sym.kind >= AMBIGUOUS) {
2493 //if nothing is found return the 'first' error
2494 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes);
2495 }
2496 return sym;
2497 }
2498 }
2500 /**
2501 * Helper class for member reference lookup. A reference lookup helper
2502 * defines the basic logic for member reference lookup; a method gives
2503 * access to an 'unbound' helper used to perform an unbound member
2504 * reference lookup.
2505 */
2506 abstract class ReferenceLookupHelper extends LookupHelper {
2508 /** The member reference tree */
2509 JCMemberReference referenceTree;
2511 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2512 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2513 super(name, site, argtypes, typeargtypes, maxPhase);
2514 this.referenceTree = referenceTree;
2516 }
2518 /**
2519 * Returns an unbound version of this lookup helper. By default, this
2520 * method returns an dummy lookup helper.
2521 */
2522 ReferenceLookupHelper unboundLookup() {
2523 //dummy loopkup helper that always return 'methodNotFound'
2524 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) {
2525 @Override
2526 ReferenceLookupHelper unboundLookup() {
2527 return this;
2528 }
2529 @Override
2530 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2531 return methodNotFound;
2532 }
2533 @Override
2534 ReferenceKind referenceKind(Symbol sym) {
2535 Assert.error();
2536 return null;
2537 }
2538 };
2539 }
2541 /**
2542 * Get the kind of the member reference
2543 */
2544 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym);
2546 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2547 if (sym.kind == AMBIGUOUS) {
2548 AmbiguityError a_err = (AmbiguityError)sym;
2549 sym = a_err.mergeAbstracts(site);
2550 }
2551 //skip error reporting
2552 return sym;
2553 }
2554 }
2556 /**
2557 * Helper class for method reference lookup. The lookup logic is based
2558 * upon Resolve.findMethod; in certain cases, this helper class has a
2559 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper).
2560 * In such cases, non-static lookup results are thrown away.
2561 */
2562 class MethodReferenceLookupHelper extends ReferenceLookupHelper {
2564 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2565 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2566 super(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2567 }
2569 protected Symbol lookupReferenceInternal(Env<AttrContext> env, MethodResolutionPhase phase) {
2570 return findMethod(env, site, name, argtypes, typeargtypes,
2571 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
2572 }
2574 protected Symbol adjustLookupResult(Env<AttrContext> env, Symbol sym) {
2575 return !TreeInfo.isStaticSelector(referenceTree.expr, names) ||
2576 sym.kind != MTH ||
2577 sym.isStatic() ? sym : new StaticError(sym);
2578 }
2580 @Override
2581 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2582 return adjustLookupResult(env, lookupReferenceInternal(env, phase));
2583 }
2585 @Override
2586 ReferenceLookupHelper unboundLookup() {
2587 if (TreeInfo.isStaticSelector(referenceTree.expr, names) &&
2588 argtypes.nonEmpty() &&
2589 types.isSubtypeUnchecked(argtypes.head, site)) {
2590 return new UnboundMethodReferenceLookupHelper(referenceTree, name,
2591 site, argtypes, typeargtypes, maxPhase);
2592 } else {
2593 return super.unboundLookup();
2594 }
2595 }
2597 @Override
2598 ReferenceKind referenceKind(Symbol sym) {
2599 if (sym.isStatic()) {
2600 return ReferenceKind.STATIC;
2601 } else {
2602 Name selName = TreeInfo.name(referenceTree.getQualifierExpression());
2603 return selName != null && selName == names._super ?
2604 ReferenceKind.SUPER :
2605 ReferenceKind.BOUND;
2606 }
2607 }
2608 }
2610 /**
2611 * Helper class for unbound method reference lookup. Essentially the same
2612 * as the basic method reference lookup helper; main difference is that static
2613 * lookup results are thrown away. If qualifier type is raw, an attempt to
2614 * infer a parameterized type is made using the first actual argument (that
2615 * would otherwise be ignored during the lookup).
2616 */
2617 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper {
2619 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2620 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2621 super(referenceTree, name,
2622 site.isRaw() ? types.asSuper(argtypes.head, site.tsym) : site,
2623 argtypes.tail, typeargtypes, maxPhase);
2624 }
2626 @Override
2627 protected Symbol adjustLookupResult(Env<AttrContext> env, Symbol sym) {
2628 return sym.kind != MTH || !sym.isStatic() ? sym : new StaticError(sym);
2629 }
2631 @Override
2632 ReferenceLookupHelper unboundLookup() {
2633 return this;
2634 }
2636 @Override
2637 ReferenceKind referenceKind(Symbol sym) {
2638 return ReferenceKind.UNBOUND;
2639 }
2640 }
2642 /**
2643 * Helper class for array constructor lookup; an array constructor lookup
2644 * is simulated by looking up a method that returns the array type specified
2645 * as qualifier, and that accepts a single int parameter (size of the array).
2646 */
2647 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper {
2649 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
2650 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2651 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
2652 }
2654 @Override
2655 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2656 Scope sc = new Scope(syms.arrayClass);
2657 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym);
2658 arrayConstr.type = new MethodType(List.of(syms.intType), site, List.<Type>nil(), syms.methodClass);
2659 sc.enter(arrayConstr);
2660 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false, false);
2661 }
2663 @Override
2664 ReferenceKind referenceKind(Symbol sym) {
2665 return ReferenceKind.ARRAY_CTOR;
2666 }
2667 }
2669 /**
2670 * Helper class for constructor reference lookup. The lookup logic is based
2671 * upon either Resolve.findMethod or Resolve.findDiamond - depending on
2672 * whether the constructor reference needs diamond inference (this is the case
2673 * if the qualifier type is raw). A special erroneous symbol is returned
2674 * if the lookup returns the constructor of an inner class and there's no
2675 * enclosing instance in scope.
2676 */
2677 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper {
2679 boolean needsInference;
2681 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
2682 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2683 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
2684 if (site.isRaw()) {
2685 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym);
2686 needsInference = true;
2687 }
2688 }
2690 @Override
2691 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2692 Symbol sym = needsInference ?
2693 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) :
2694 findMethod(env, site, name, argtypes, typeargtypes,
2695 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
2696 return sym.kind != MTH ||
2697 site.getEnclosingType().hasTag(NONE) ||
2698 hasEnclosingInstance(env, site) ?
2699 sym : new InvalidSymbolError(Kinds.MISSING_ENCL, sym, null) {
2700 @Override
2701 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
2702 return diags.create(dkind, log.currentSource(), pos,
2703 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType());
2704 }
2705 };
2706 }
2708 @Override
2709 ReferenceKind referenceKind(Symbol sym) {
2710 return site.getEnclosingType().hasTag(NONE) ?
2711 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER;
2712 }
2713 }
2715 /**
2716 * Main overload resolution routine. On each overload resolution step, a
2717 * lookup helper class is used to perform the method/constructor lookup;
2718 * at the end of the lookup, the helper is used to validate the results
2719 * (this last step might trigger overload resolution diagnostics).
2720 */
2721 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, LookupHelper lookupHelper) {
2722 return lookupMethod(env, pos, location, new MethodResolutionContext(), lookupHelper);
2723 }
2725 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location,
2726 MethodResolutionContext resolveContext, LookupHelper lookupHelper) {
2727 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2728 try {
2729 Symbol bestSoFar = methodNotFound;
2730 currentResolutionContext = resolveContext;
2731 for (MethodResolutionPhase phase : methodResolutionSteps) {
2732 if (!phase.isApplicable(boxingEnabled, varargsEnabled) ||
2733 lookupHelper.shouldStop(bestSoFar, phase)) break;
2734 MethodResolutionPhase prevPhase = currentResolutionContext.step;
2735 Symbol prevBest = bestSoFar;
2736 currentResolutionContext.step = phase;
2737 bestSoFar = phase.mergeResults(bestSoFar, lookupHelper.lookup(env, phase));
2738 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase;
2739 }
2740 return lookupHelper.access(env, pos, location, bestSoFar);
2741 } finally {
2742 currentResolutionContext = prevResolutionContext;
2743 }
2744 }
2746 /**
2747 * Resolve `c.name' where name == this or name == super.
2748 * @param pos The position to use for error reporting.
2749 * @param env The environment current at the expression.
2750 * @param c The qualifier.
2751 * @param name The identifier's name.
2752 */
2753 Symbol resolveSelf(DiagnosticPosition pos,
2754 Env<AttrContext> env,
2755 TypeSymbol c,
2756 Name name) {
2757 Env<AttrContext> env1 = env;
2758 boolean staticOnly = false;
2759 while (env1.outer != null) {
2760 if (isStatic(env1)) staticOnly = true;
2761 if (env1.enclClass.sym == c) {
2762 Symbol sym = env1.info.scope.lookup(name).sym;
2763 if (sym != null) {
2764 if (staticOnly) sym = new StaticError(sym);
2765 return accessBase(sym, pos, env.enclClass.sym.type,
2766 name, true);
2767 }
2768 }
2769 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
2770 env1 = env1.outer;
2771 }
2772 if (allowDefaultMethods && c.isInterface() &&
2773 name == names._super && !isStatic(env) &&
2774 types.isDirectSuperInterface(c, env.enclClass.sym)) {
2775 //this might be a default super call if one of the superinterfaces is 'c'
2776 for (Type t : pruneInterfaces(env.enclClass.type)) {
2777 if (t.tsym == c) {
2778 env.info.defaultSuperCallSite = t;
2779 return new VarSymbol(0, names._super,
2780 types.asSuper(env.enclClass.type, c), env.enclClass.sym);
2781 }
2782 }
2783 //find a direct superinterface that is a subtype of 'c'
2784 for (Type i : types.interfaces(env.enclClass.type)) {
2785 if (i.tsym.isSubClass(c, types) && i.tsym != c) {
2786 log.error(pos, "illegal.default.super.call", c,
2787 diags.fragment("redundant.supertype", c, i));
2788 return syms.errSymbol;
2789 }
2790 }
2791 Assert.error();
2792 }
2793 log.error(pos, "not.encl.class", c);
2794 return syms.errSymbol;
2795 }
2796 //where
2797 private List<Type> pruneInterfaces(Type t) {
2798 ListBuffer<Type> result = ListBuffer.lb();
2799 for (Type t1 : types.interfaces(t)) {
2800 boolean shouldAdd = true;
2801 for (Type t2 : types.interfaces(t)) {
2802 if (t1 != t2 && types.isSubtypeNoCapture(t2, t1)) {
2803 shouldAdd = false;
2804 }
2805 }
2806 if (shouldAdd) {
2807 result.append(t1);
2808 }
2809 }
2810 return result.toList();
2811 }
2814 /**
2815 * Resolve `c.this' for an enclosing class c that contains the
2816 * named member.
2817 * @param pos The position to use for error reporting.
2818 * @param env The environment current at the expression.
2819 * @param member The member that must be contained in the result.
2820 */
2821 Symbol resolveSelfContaining(DiagnosticPosition pos,
2822 Env<AttrContext> env,
2823 Symbol member,
2824 boolean isSuperCall) {
2825 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall);
2826 if (sym == null) {
2827 log.error(pos, "encl.class.required", member);
2828 return syms.errSymbol;
2829 } else {
2830 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true);
2831 }
2832 }
2834 boolean hasEnclosingInstance(Env<AttrContext> env, Type type) {
2835 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false);
2836 return encl != null && encl.kind < ERRONEOUS;
2837 }
2839 private Symbol resolveSelfContainingInternal(Env<AttrContext> env,
2840 Symbol member,
2841 boolean isSuperCall) {
2842 Name name = names._this;
2843 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
2844 boolean staticOnly = false;
2845 if (env1 != null) {
2846 while (env1 != null && env1.outer != null) {
2847 if (isStatic(env1)) staticOnly = true;
2848 if (env1.enclClass.sym.isSubClass(member.owner, types)) {
2849 Symbol sym = env1.info.scope.lookup(name).sym;
2850 if (sym != null) {
2851 if (staticOnly) sym = new StaticError(sym);
2852 return sym;
2853 }
2854 }
2855 if ((env1.enclClass.sym.flags() & STATIC) != 0)
2856 staticOnly = true;
2857 env1 = env1.outer;
2858 }
2859 }
2860 return null;
2861 }
2863 /**
2864 * Resolve an appropriate implicit this instance for t's container.
2865 * JLS 8.8.5.1 and 15.9.2
2866 */
2867 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
2868 return resolveImplicitThis(pos, env, t, false);
2869 }
2871 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
2872 Type thisType = (((t.tsym.owner.kind & (MTH|VAR)) != 0)
2873 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
2874 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
2875 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym)
2876 log.error(pos, "cant.ref.before.ctor.called", "this");
2877 return thisType;
2878 }
2880 /* ***************************************************************************
2881 * ResolveError classes, indicating error situations when accessing symbols
2882 ****************************************************************************/
2884 //used by TransTypes when checking target type of synthetic cast
2885 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) {
2886 AccessError error = new AccessError(env, env.enclClass.type, type.tsym);
2887 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null);
2888 }
2889 //where
2890 private void logResolveError(ResolveError error,
2891 DiagnosticPosition pos,
2892 Symbol location,
2893 Type site,
2894 Name name,
2895 List<Type> argtypes,
2896 List<Type> typeargtypes) {
2897 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
2898 pos, location, site, name, argtypes, typeargtypes);
2899 if (d != null) {
2900 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
2901 log.report(d);
2902 }
2903 }
2905 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
2907 public Object methodArguments(List<Type> argtypes) {
2908 if (argtypes == null || argtypes.isEmpty()) {
2909 return noArgs;
2910 } else {
2911 ListBuffer<Object> diagArgs = ListBuffer.lb();
2912 for (Type t : argtypes) {
2913 if (t.hasTag(DEFERRED)) {
2914 diagArgs.append(((DeferredAttr.DeferredType)t).tree);
2915 } else {
2916 diagArgs.append(t);
2917 }
2918 }
2919 return diagArgs;
2920 }
2921 }
2923 /**
2924 * Root class for resolution errors. Subclass of ResolveError
2925 * represent a different kinds of resolution error - as such they must
2926 * specify how they map into concrete compiler diagnostics.
2927 */
2928 abstract class ResolveError extends Symbol {
2930 /** The name of the kind of error, for debugging only. */
2931 final String debugName;
2933 ResolveError(int kind, String debugName) {
2934 super(kind, 0, null, null, null);
2935 this.debugName = debugName;
2936 }
2938 @Override
2939 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
2940 throw new AssertionError();
2941 }
2943 @Override
2944 public String toString() {
2945 return debugName;
2946 }
2948 @Override
2949 public boolean exists() {
2950 return false;
2951 }
2953 /**
2954 * Create an external representation for this erroneous symbol to be
2955 * used during attribution - by default this returns the symbol of a
2956 * brand new error type which stores the original type found
2957 * during resolution.
2958 *
2959 * @param name the name used during resolution
2960 * @param location the location from which the symbol is accessed
2961 */
2962 protected Symbol access(Name name, TypeSymbol location) {
2963 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
2964 }
2966 /**
2967 * Create a diagnostic representing this resolution error.
2968 *
2969 * @param dkind The kind of the diagnostic to be created (e.g error).
2970 * @param pos The position to be used for error reporting.
2971 * @param site The original type from where the selection took place.
2972 * @param name The name of the symbol to be resolved.
2973 * @param argtypes The invocation's value arguments,
2974 * if we looked for a method.
2975 * @param typeargtypes The invocation's type arguments,
2976 * if we looked for a method.
2977 */
2978 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2979 DiagnosticPosition pos,
2980 Symbol location,
2981 Type site,
2982 Name name,
2983 List<Type> argtypes,
2984 List<Type> typeargtypes);
2985 }
2987 /**
2988 * This class is the root class of all resolution errors caused by
2989 * an invalid symbol being found during resolution.
2990 */
2991 abstract class InvalidSymbolError extends ResolveError {
2993 /** The invalid symbol found during resolution */
2994 Symbol sym;
2996 InvalidSymbolError(int kind, Symbol sym, String debugName) {
2997 super(kind, debugName);
2998 this.sym = sym;
2999 }
3001 @Override
3002 public boolean exists() {
3003 return true;
3004 }
3006 @Override
3007 public String toString() {
3008 return super.toString() + " wrongSym=" + sym;
3009 }
3011 @Override
3012 public Symbol access(Name name, TypeSymbol location) {
3013 if ((sym.kind & ERRONEOUS) == 0 && (sym.kind & TYP) != 0)
3014 return types.createErrorType(name, location, sym.type).tsym;
3015 else
3016 return sym;
3017 }
3018 }
3020 /**
3021 * InvalidSymbolError error class indicating that a symbol matching a
3022 * given name does not exists in a given site.
3023 */
3024 class SymbolNotFoundError extends ResolveError {
3026 SymbolNotFoundError(int kind) {
3027 super(kind, "symbol not found error");
3028 }
3030 @Override
3031 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3032 DiagnosticPosition pos,
3033 Symbol location,
3034 Type site,
3035 Name name,
3036 List<Type> argtypes,
3037 List<Type> typeargtypes) {
3038 argtypes = argtypes == null ? List.<Type>nil() : argtypes;
3039 typeargtypes = typeargtypes == null ? List.<Type>nil() : typeargtypes;
3040 if (name == names.error)
3041 return null;
3043 if (syms.operatorNames.contains(name)) {
3044 boolean isUnaryOp = argtypes.size() == 1;
3045 String key = argtypes.size() == 1 ?
3046 "operator.cant.be.applied" :
3047 "operator.cant.be.applied.1";
3048 Type first = argtypes.head;
3049 Type second = !isUnaryOp ? argtypes.tail.head : null;
3050 return diags.create(dkind, log.currentSource(), pos,
3051 key, name, first, second);
3052 }
3053 boolean hasLocation = false;
3054 if (location == null) {
3055 location = site.tsym;
3056 }
3057 if (!location.name.isEmpty()) {
3058 if (location.kind == PCK && !site.tsym.exists()) {
3059 return diags.create(dkind, log.currentSource(), pos,
3060 "doesnt.exist", location);
3061 }
3062 hasLocation = !location.name.equals(names._this) &&
3063 !location.name.equals(names._super);
3064 }
3065 boolean isConstructor = kind == ABSENT_MTH && name == names.init;
3066 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : absentKind(kind);
3067 Name idname = isConstructor ? site.tsym.name : name;
3068 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
3069 if (hasLocation) {
3070 return diags.create(dkind, log.currentSource(), pos,
3071 errKey, kindname, idname, //symbol kindname, name
3072 typeargtypes, args(argtypes), //type parameters and arguments (if any)
3073 getLocationDiag(location, site)); //location kindname, type
3074 }
3075 else {
3076 return diags.create(dkind, log.currentSource(), pos,
3077 errKey, kindname, idname, //symbol kindname, name
3078 typeargtypes, args(argtypes)); //type parameters and arguments (if any)
3079 }
3080 }
3081 //where
3082 private Object args(List<Type> args) {
3083 return args.isEmpty() ? args : methodArguments(args);
3084 }
3086 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
3087 String key = "cant.resolve";
3088 String suffix = hasLocation ? ".location" : "";
3089 switch (kindname) {
3090 case METHOD:
3091 case CONSTRUCTOR: {
3092 suffix += ".args";
3093 suffix += hasTypeArgs ? ".params" : "";
3094 }
3095 }
3096 return key + suffix;
3097 }
3098 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
3099 if (location.kind == VAR) {
3100 return diags.fragment("location.1",
3101 kindName(location),
3102 location,
3103 location.type);
3104 } else {
3105 return diags.fragment("location",
3106 typeKindName(site),
3107 site,
3108 null);
3109 }
3110 }
3111 }
3113 /**
3114 * InvalidSymbolError error class indicating that a given symbol
3115 * (either a method, a constructor or an operand) is not applicable
3116 * given an actual arguments/type argument list.
3117 */
3118 class InapplicableSymbolError extends ResolveError {
3120 protected MethodResolutionContext resolveContext;
3122 InapplicableSymbolError(MethodResolutionContext context) {
3123 this(WRONG_MTH, "inapplicable symbol error", context);
3124 }
3126 protected InapplicableSymbolError(int kind, String debugName, MethodResolutionContext context) {
3127 super(kind, debugName);
3128 this.resolveContext = context;
3129 }
3131 @Override
3132 public String toString() {
3133 return super.toString();
3134 }
3136 @Override
3137 public boolean exists() {
3138 return true;
3139 }
3141 @Override
3142 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3143 DiagnosticPosition pos,
3144 Symbol location,
3145 Type site,
3146 Name name,
3147 List<Type> argtypes,
3148 List<Type> typeargtypes) {
3149 if (name == names.error)
3150 return null;
3152 if (syms.operatorNames.contains(name)) {
3153 boolean isUnaryOp = argtypes.size() == 1;
3154 String key = argtypes.size() == 1 ?
3155 "operator.cant.be.applied" :
3156 "operator.cant.be.applied.1";
3157 Type first = argtypes.head;
3158 Type second = !isUnaryOp ? argtypes.tail.head : null;
3159 return diags.create(dkind, log.currentSource(), pos,
3160 key, name, first, second);
3161 }
3162 else {
3163 Candidate c = errCandidate();
3164 Symbol ws = c.sym.asMemberOf(site, types);
3165 return diags.create(dkind, log.currentSource(), pos,
3166 "cant.apply.symbol",
3167 kindName(ws),
3168 ws.name == names.init ? ws.owner.name : ws.name,
3169 methodArguments(ws.type.getParameterTypes()),
3170 methodArguments(argtypes),
3171 kindName(ws.owner),
3172 ws.owner.type,
3173 c.details);
3174 }
3175 }
3177 @Override
3178 public Symbol access(Name name, TypeSymbol location) {
3179 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3180 }
3182 private Candidate errCandidate() {
3183 Candidate bestSoFar = null;
3184 for (Candidate c : resolveContext.candidates) {
3185 if (c.isApplicable()) continue;
3186 bestSoFar = c;
3187 }
3188 Assert.checkNonNull(bestSoFar);
3189 return bestSoFar;
3190 }
3191 }
3193 /**
3194 * ResolveError error class indicating that a set of symbols
3195 * (either methods, constructors or operands) is not applicable
3196 * given an actual arguments/type argument list.
3197 */
3198 class InapplicableSymbolsError extends InapplicableSymbolError {
3200 InapplicableSymbolsError(MethodResolutionContext context) {
3201 super(WRONG_MTHS, "inapplicable symbols", context);
3202 }
3204 @Override
3205 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3206 DiagnosticPosition pos,
3207 Symbol location,
3208 Type site,
3209 Name name,
3210 List<Type> argtypes,
3211 List<Type> typeargtypes) {
3212 if (!resolveContext.candidates.isEmpty()) {
3213 JCDiagnostic err = diags.create(dkind,
3214 log.currentSource(),
3215 pos,
3216 "cant.apply.symbols",
3217 name == names.init ? KindName.CONSTRUCTOR : absentKind(kind),
3218 name == names.init ? site.tsym.name : name,
3219 methodArguments(argtypes));
3220 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(site));
3221 } else {
3222 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
3223 location, site, name, argtypes, typeargtypes);
3224 }
3225 }
3227 //where
3228 List<JCDiagnostic> candidateDetails(Type site) {
3229 Map<Symbol, JCDiagnostic> details = new LinkedHashMap<Symbol, JCDiagnostic>();
3230 for (Candidate c : resolveContext.candidates) {
3231 if (c.isApplicable()) continue;
3232 JCDiagnostic detailDiag = diags.fragment("inapplicable.method",
3233 Kinds.kindName(c.sym),
3234 c.sym.location(site, types),
3235 c.sym.asMemberOf(site, types),
3236 c.details);
3237 details.put(c.sym, detailDiag);
3238 }
3239 return List.from(details.values());
3240 }
3241 }
3243 /**
3244 * An InvalidSymbolError error class indicating that a symbol is not
3245 * accessible from a given site
3246 */
3247 class AccessError extends InvalidSymbolError {
3249 private Env<AttrContext> env;
3250 private Type site;
3252 AccessError(Symbol sym) {
3253 this(null, null, sym);
3254 }
3256 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
3257 super(HIDDEN, sym, "access error");
3258 this.env = env;
3259 this.site = site;
3260 if (debugResolve)
3261 log.error("proc.messager", sym + " @ " + site + " is inaccessible.");
3262 }
3264 @Override
3265 public boolean exists() {
3266 return false;
3267 }
3269 @Override
3270 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3271 DiagnosticPosition pos,
3272 Symbol location,
3273 Type site,
3274 Name name,
3275 List<Type> argtypes,
3276 List<Type> typeargtypes) {
3277 if (sym.owner.type.hasTag(ERROR))
3278 return null;
3280 if (sym.name == names.init && sym.owner != site.tsym) {
3281 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
3282 pos, location, site, name, argtypes, typeargtypes);
3283 }
3284 else if ((sym.flags() & PUBLIC) != 0
3285 || (env != null && this.site != null
3286 && !isAccessible(env, this.site))) {
3287 return diags.create(dkind, log.currentSource(),
3288 pos, "not.def.access.class.intf.cant.access",
3289 sym, sym.location());
3290 }
3291 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
3292 return diags.create(dkind, log.currentSource(),
3293 pos, "report.access", sym,
3294 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
3295 sym.location());
3296 }
3297 else {
3298 return diags.create(dkind, log.currentSource(),
3299 pos, "not.def.public.cant.access", sym, sym.location());
3300 }
3301 }
3302 }
3304 /**
3305 * InvalidSymbolError error class indicating that an instance member
3306 * has erroneously been accessed from a static context.
3307 */
3308 class StaticError extends InvalidSymbolError {
3310 StaticError(Symbol sym) {
3311 super(STATICERR, sym, "static error");
3312 }
3314 @Override
3315 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3316 DiagnosticPosition pos,
3317 Symbol location,
3318 Type site,
3319 Name name,
3320 List<Type> argtypes,
3321 List<Type> typeargtypes) {
3322 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS))
3323 ? types.erasure(sym.type).tsym
3324 : sym);
3325 return diags.create(dkind, log.currentSource(), pos,
3326 "non-static.cant.be.ref", kindName(sym), errSym);
3327 }
3328 }
3330 /**
3331 * InvalidSymbolError error class indicating that a pair of symbols
3332 * (either methods, constructors or operands) are ambiguous
3333 * given an actual arguments/type argument list.
3334 */
3335 class AmbiguityError extends ResolveError {
3337 /** The other maximally specific symbol */
3338 List<Symbol> ambiguousSyms = List.nil();
3340 @Override
3341 public boolean exists() {
3342 return true;
3343 }
3345 AmbiguityError(Symbol sym1, Symbol sym2) {
3346 super(AMBIGUOUS, "ambiguity error");
3347 ambiguousSyms = flatten(sym2).appendList(flatten(sym1));
3348 }
3350 private List<Symbol> flatten(Symbol sym) {
3351 if (sym.kind == AMBIGUOUS) {
3352 return ((AmbiguityError)sym).ambiguousSyms;
3353 } else {
3354 return List.of(sym);
3355 }
3356 }
3358 AmbiguityError addAmbiguousSymbol(Symbol s) {
3359 ambiguousSyms = ambiguousSyms.prepend(s);
3360 return this;
3361 }
3363 @Override
3364 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3365 DiagnosticPosition pos,
3366 Symbol location,
3367 Type site,
3368 Name name,
3369 List<Type> argtypes,
3370 List<Type> typeargtypes) {
3371 List<Symbol> diagSyms = ambiguousSyms.reverse();
3372 Symbol s1 = diagSyms.head;
3373 Symbol s2 = diagSyms.tail.head;
3374 Name sname = s1.name;
3375 if (sname == names.init) sname = s1.owner.name;
3376 return diags.create(dkind, log.currentSource(),
3377 pos, "ref.ambiguous", sname,
3378 kindName(s1),
3379 s1,
3380 s1.location(site, types),
3381 kindName(s2),
3382 s2,
3383 s2.location(site, types));
3384 }
3386 /**
3387 * If multiple applicable methods are found during overload and none of them
3388 * is more specific than the others, attempt to merge their signatures.
3389 */
3390 Symbol mergeAbstracts(Type site) {
3391 Symbol fst = ambiguousSyms.last();
3392 Symbol res = fst;
3393 for (Symbol s : ambiguousSyms.reverse()) {
3394 Type mt1 = types.memberType(site, res);
3395 Type mt2 = types.memberType(site, s);
3396 if ((s.flags() & ABSTRACT) == 0 ||
3397 !types.overrideEquivalent(mt1, mt2) ||
3398 !types.isSameTypes(fst.erasure(types).getParameterTypes(),
3399 s.erasure(types).getParameterTypes())) {
3400 //ambiguity cannot be resolved
3401 return this;
3402 } else {
3403 Type mst = mostSpecificReturnType(mt1, mt2);
3404 if (mst == null) {
3405 // Theoretically, this can't happen, but it is possible
3406 // due to error recovery or mixing incompatible class files
3407 return this;
3408 }
3409 Symbol mostSpecific = mst == mt1 ? res : s;
3410 List<Type> allThrown = chk.intersect(mt1.getThrownTypes(), mt2.getThrownTypes());
3411 Type newSig = types.createMethodTypeWithThrown(mostSpecific.type, allThrown);
3412 res = new MethodSymbol(
3413 mostSpecific.flags(),
3414 mostSpecific.name,
3415 newSig,
3416 mostSpecific.owner);
3417 }
3418 }
3419 return res;
3420 }
3422 @Override
3423 protected Symbol access(Name name, TypeSymbol location) {
3424 Symbol firstAmbiguity = ambiguousSyms.last();
3425 return firstAmbiguity.kind == TYP ?
3426 types.createErrorType(name, location, firstAmbiguity.type).tsym :
3427 firstAmbiguity;
3428 }
3429 }
3431 enum MethodResolutionPhase {
3432 BASIC(false, false),
3433 BOX(true, false),
3434 VARARITY(true, true) {
3435 @Override
3436 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) {
3437 switch (sym.kind) {
3438 case WRONG_MTH:
3439 return (bestSoFar.kind == WRONG_MTH || bestSoFar.kind == WRONG_MTHS) ?
3440 bestSoFar :
3441 sym;
3442 case ABSENT_MTH:
3443 return bestSoFar;
3444 default:
3445 return sym;
3446 }
3447 }
3448 };
3450 final boolean isBoxingRequired;
3451 final boolean isVarargsRequired;
3453 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
3454 this.isBoxingRequired = isBoxingRequired;
3455 this.isVarargsRequired = isVarargsRequired;
3456 }
3458 public boolean isBoxingRequired() {
3459 return isBoxingRequired;
3460 }
3462 public boolean isVarargsRequired() {
3463 return isVarargsRequired;
3464 }
3466 public boolean isApplicable(boolean boxingEnabled, boolean varargsEnabled) {
3467 return (varargsEnabled || !isVarargsRequired) &&
3468 (boxingEnabled || !isBoxingRequired);
3469 }
3471 public Symbol mergeResults(Symbol prev, Symbol sym) {
3472 return sym;
3473 }
3474 }
3476 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
3478 /**
3479 * A resolution context is used to keep track of intermediate results of
3480 * overload resolution, such as list of method that are not applicable
3481 * (used to generate more precise diagnostics) and so on. Resolution contexts
3482 * can be nested - this means that when each overload resolution routine should
3483 * work within the resolution context it created.
3484 */
3485 class MethodResolutionContext {
3487 private List<Candidate> candidates = List.nil();
3489 MethodResolutionPhase step = null;
3491 private boolean internalResolution = false;
3492 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE;
3494 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) {
3495 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null);
3496 candidates = candidates.append(c);
3497 }
3499 void addApplicableCandidate(Symbol sym, Type mtype) {
3500 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype);
3501 candidates = candidates.append(c);
3502 }
3504 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext) {
3505 return deferredAttr.new DeferredAttrContext(attrMode, sym, step, inferenceContext);
3506 }
3508 /**
3509 * This class represents an overload resolution candidate. There are two
3510 * kinds of candidates: applicable methods and inapplicable methods;
3511 * applicable methods have a pointer to the instantiated method type,
3512 * while inapplicable candidates contain further details about the
3513 * reason why the method has been considered inapplicable.
3514 */
3515 class Candidate {
3517 final MethodResolutionPhase step;
3518 final Symbol sym;
3519 final JCDiagnostic details;
3520 final Type mtype;
3522 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) {
3523 this.step = step;
3524 this.sym = sym;
3525 this.details = details;
3526 this.mtype = mtype;
3527 }
3529 @Override
3530 public boolean equals(Object o) {
3531 if (o instanceof Candidate) {
3532 Symbol s1 = this.sym;
3533 Symbol s2 = ((Candidate)o).sym;
3534 if ((s1 != s2 &&
3535 (s1.overrides(s2, s1.owner.type.tsym, types, false) ||
3536 (s2.overrides(s1, s2.owner.type.tsym, types, false)))) ||
3537 ((s1.isConstructor() || s2.isConstructor()) && s1.owner != s2.owner))
3538 return true;
3539 }
3540 return false;
3541 }
3543 boolean isApplicable() {
3544 return mtype != null;
3545 }
3546 }
3548 DeferredAttr.AttrMode attrMode() {
3549 return attrMode;
3550 }
3552 boolean internal() {
3553 return internalResolution;
3554 }
3555 }
3557 MethodResolutionContext currentResolutionContext = null;
3558 }