1 /*
2 * Copyright (c) 1999, 2018, 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 */
25
26 package com.sun.tools.javac.comp;
27
28 import com.sun.tools.javac.api.Formattable.LocalizedString;
29 import com.sun.tools.javac.code.*;
30 import com.sun.tools.javac.code.Scope.WriteableScope;
31 import com.sun.tools.javac.code.Source.Feature;
32 import com.sun.tools.javac.code.Symbol.*;
33 import com.sun.tools.javac.code.Type.*;
34 import com.sun.tools.javac.comp.Attr.ResultInfo;
35 import com.sun.tools.javac.comp.Check.CheckContext;
36 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
37 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
38 import com.sun.tools.javac.comp.DeferredAttr.DeferredType;
39 import com.sun.tools.javac.comp.Resolve.MethodResolutionContext.Candidate;
40 import com.sun.tools.javac.comp.Resolve.MethodResolutionDiagHelper.Template;
41 import com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind;
42 import com.sun.tools.javac.jvm.*;
43 import com.sun.tools.javac.main.Option;
44 import com.sun.tools.javac.resources.CompilerProperties.Errors;
45 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
46 import com.sun.tools.javac.tree.*;
47 import com.sun.tools.javac.tree.JCTree.*;
48 import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind;
49 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
50 import com.sun.tools.javac.util.*;
51 import com.sun.tools.javac.util.DefinedBy.Api;
52 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
53 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
54 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
55
56 import java.util.Arrays;
57 import java.util.Collection;
58 import java.util.EnumSet;
59 import java.util.HashSet;
60 import java.util.Iterator;
61 import java.util.LinkedHashMap;
62 import java.util.Map;
63 import java.util.Set;
64 import java.util.function.BiFunction;
65 import java.util.function.BiPredicate;
66 import java.util.function.Function;
67 import java.util.function.Predicate;
68 import java.util.stream.Stream;
69
70 import javax.lang.model.element.ElementVisitor;
71
72 import static com.sun.tools.javac.code.Flags.*;
73 import static com.sun.tools.javac.code.Flags.BLOCK;
74 import static com.sun.tools.javac.code.Flags.STATIC;
75 import static com.sun.tools.javac.code.Kinds.*;
76 import static com.sun.tools.javac.code.Kinds.Kind.*;
77 import static com.sun.tools.javac.code.TypeTag.*;
78 import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*;
79 import static com.sun.tools.javac.tree.JCTree.Tag.*;
80 import static com.sun.tools.javac.util.Iterators.createCompoundIterator;
81
82 /** Helper class for name resolution, used mostly by the attribution phase.
83 *
84 * <p><b>This is NOT part of any supported API.
85 * If you write code that depends on this, you do so at your own risk.
86 * This code and its internal interfaces are subject to change or
87 * deletion without notice.</b>
88 */
89 public class Resolve {
90 protected static final Context.Key<Resolve> resolveKey = new Context.Key<>();
91
92 Names names;
93 Log log;
94 Symtab syms;
95 Attr attr;
96 DeferredAttr deferredAttr;
97 Check chk;
98 Infer infer;
99 ClassFinder finder;
100 ModuleFinder moduleFinder;
101 Types types;
102 JCDiagnostic.Factory diags;
103 public final boolean allowMethodHandles;
104 public final boolean allowFunctionalInterfaceMostSpecific;
105 public final boolean allowModules;
106 public final boolean checkVarargsAccessAfterResolution;
107 private final boolean compactMethodDiags;
108 private final boolean allowLocalVariableTypeInference;
109 final EnumSet<VerboseResolutionMode> verboseResolutionMode;
110
111 WriteableScope polymorphicSignatureScope;
112
113 protected Resolve(Context context) {
114 context.put(resolveKey, this);
115 syms = Symtab.instance(context);
116
117 varNotFound = new SymbolNotFoundError(ABSENT_VAR);
118 methodNotFound = new SymbolNotFoundError(ABSENT_MTH);
119 typeNotFound = new SymbolNotFoundError(ABSENT_TYP);
120 referenceNotFound = ReferenceLookupResult.error(methodNotFound);
121
122 names = Names.instance(context);
123 log = Log.instance(context);
124 attr = Attr.instance(context);
125 deferredAttr = DeferredAttr.instance(context);
126 chk = Check.instance(context);
127 infer = Infer.instance(context);
128 finder = ClassFinder.instance(context);
129 moduleFinder = ModuleFinder.instance(context);
130 types = Types.instance(context);
131 diags = JCDiagnostic.Factory.instance(context);
132 Source source = Source.instance(context);
133 Options options = Options.instance(context);
134 compactMethodDiags = options.isSet(Option.XDIAGS, "compact") ||
135 options.isUnset(Option.XDIAGS) && options.isUnset("rawDiagnostics");
136 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
137 Target target = Target.instance(context);
138 allowMethodHandles = target.hasMethodHandles();
139 allowFunctionalInterfaceMostSpecific = Feature.FUNCTIONAL_INTERFACE_MOST_SPECIFIC.allowedInSource(source);
140 allowLocalVariableTypeInference = Feature.LOCAL_VARIABLE_TYPE_INFERENCE.allowedInSource(source);
141 checkVarargsAccessAfterResolution =
142 Feature.POST_APPLICABILITY_VARARGS_ACCESS_CHECK.allowedInSource(source);
143 polymorphicSignatureScope = WriteableScope.create(syms.noSymbol);
144 allowModules = Feature.MODULES.allowedInSource(source);
145 }
146
147 /** error symbols, which are returned when resolution fails
148 */
149 private final SymbolNotFoundError varNotFound;
150 private final SymbolNotFoundError methodNotFound;
151 private final SymbolNotFoundError typeNotFound;
152
153 /** empty reference lookup result */
154 private final ReferenceLookupResult referenceNotFound;
155
156 public static Resolve instance(Context context) {
157 Resolve instance = context.get(resolveKey);
158 if (instance == null)
159 instance = new Resolve(context);
160 return instance;
161 }
162
163 private static Symbol bestOf(Symbol s1,
164 Symbol s2) {
165 return s1.kind.betterThan(s2.kind) ? s1 : s2;
166 }
167
168 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support">
169 enum VerboseResolutionMode {
170 SUCCESS("success"),
171 FAILURE("failure"),
172 APPLICABLE("applicable"),
173 INAPPLICABLE("inapplicable"),
174 DEFERRED_INST("deferred-inference"),
175 PREDEF("predef"),
176 OBJECT_INIT("object-init"),
177 INTERNAL("internal");
178
179 final String opt;
180
181 private VerboseResolutionMode(String opt) {
182 this.opt = opt;
183 }
184
185 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) {
186 String s = opts.get("debug.verboseResolution");
187 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class);
188 if (s == null) return res;
189 if (s.contains("all")) {
190 res = EnumSet.allOf(VerboseResolutionMode.class);
191 }
192 Collection<String> args = Arrays.asList(s.split(","));
193 for (VerboseResolutionMode mode : values()) {
194 if (args.contains(mode.opt)) {
195 res.add(mode);
196 } else if (args.contains("-" + mode.opt)) {
197 res.remove(mode);
198 }
199 }
200 return res;
201 }
202 }
203
204 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site,
205 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) {
206 boolean success = !bestSoFar.kind.isResolutionError();
207
208 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) {
209 return;
210 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) {
211 return;
212 }
213
214 if (bestSoFar.name == names.init &&
215 bestSoFar.owner == syms.objectType.tsym &&
216 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) {
217 return; //skip diags for Object constructor resolution
218 } else if (site == syms.predefClass.type &&
219 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) {
220 return; //skip spurious diags for predef symbols (i.e. operators)
221 } else if (currentResolutionContext.internalResolution &&
222 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) {
223 return;
224 }
225
226 int pos = 0;
227 int mostSpecificPos = -1;
228 ListBuffer<JCDiagnostic> subDiags = new ListBuffer<>();
229 for (Candidate c : currentResolutionContext.candidates) {
230 if (currentResolutionContext.step != c.step ||
231 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) ||
232 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) {
233 continue;
234 } else {
235 subDiags.append(c.isApplicable() ?
236 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) :
237 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details));
238 if (c.sym == bestSoFar)
239 mostSpecificPos = pos;
240 pos++;
241 }
242 }
243 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1";
244 List<Type> argtypes2 = argtypes.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step));
245 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name,
246 site.tsym, mostSpecificPos, currentResolutionContext.step,
247 methodArguments(argtypes2),
248 methodArguments(typeargtypes));
249 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
250 log.report(d);
251 }
252
253 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) {
254 JCDiagnostic subDiag = null;
255 if (sym.type.hasTag(FORALL)) {
256 subDiag = diags.fragment(Fragments.PartialInstSig(inst));
257 }
258
259 String key = subDiag == null ?
260 "applicable.method.found" :
261 "applicable.method.found.1";
262
263 return diags.fragment(key, pos, sym, subDiag);
264 }
265
266 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) {
267 return diags.fragment(Fragments.NotApplicableMethodFound(pos, sym, subDiag));
268 }
269 // </editor-fold>
270
271 /* ************************************************************************
272 * Identifier resolution
273 *************************************************************************/
274
275 /** An environment is "static" if its static level is greater than
276 * the one of its outer environment
277 */
278 protected static boolean isStatic(Env<AttrContext> env) {
279 return env.outer != null && env.info.staticLevel > env.outer.info.staticLevel;
280 }
281
282 /** An environment is an "initializer" if it is a constructor or
283 * an instance initializer.
284 */
285 static boolean isInitializer(Env<AttrContext> env) {
286 Symbol owner = env.info.scope.owner;
287 return owner.isConstructor() ||
288 owner.owner.kind == TYP &&
289 (owner.kind == VAR ||
290 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
291 (owner.flags() & STATIC) == 0;
292 }
293
294 /** Is class accessible in given evironment?
295 * @param env The current environment.
296 * @param c The class whose accessibility is checked.
297 */
298 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
299 return isAccessible(env, c, false);
300 }
301
302 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) {
303
304 /* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor
305 to refer to an inaccessible type
306 */
307 if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0)
308 return true;
309
310 if (env.info.visitingServiceImplementation &&
311 env.toplevel.modle == c.packge().modle) {
312 return true;
313 }
314
315 boolean isAccessible = false;
316 switch ((short)(c.flags() & AccessFlags)) {
317 case PRIVATE:
318 isAccessible =
319 env.enclClass.sym.outermostClass() ==
320 c.owner.outermostClass();
321 break;
322 case 0:
323 isAccessible =
324 env.toplevel.packge == c.owner // fast special case
325 ||
326 env.toplevel.packge == c.packge();
327 break;
328 default: // error recovery
329 isAccessible = true;
330 break;
331 case PUBLIC:
332 if (allowModules) {
333 ModuleSymbol currModule = env.toplevel.modle;
334 currModule.complete();
335 PackageSymbol p = c.packge();
336 isAccessible =
337 currModule == p.modle ||
338 currModule.visiblePackages.get(p.fullname) == p ||
339 p == syms.rootPackage ||
340 (p.modle == syms.unnamedModule && currModule.readModules.contains(p.modle));
341 } else {
342 isAccessible = true;
343 }
344 break;
345 case PROTECTED:
346 isAccessible =
347 env.toplevel.packge == c.owner // fast special case
348 ||
349 env.toplevel.packge == c.packge()
350 ||
351 isInnerSubClass(env.enclClass.sym, c.owner);
352 break;
353 }
354 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
355 isAccessible :
356 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
357 }
358 //where
359 /** Is given class a subclass of given base class, or an inner class
360 * of a subclass?
361 * Return null if no such class exists.
362 * @param c The class which is the subclass or is contained in it.
363 * @param base The base class
364 */
365 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
366 while (c != null && !c.isSubClass(base, types)) {
367 c = c.owner.enclClass();
368 }
369 return c != null;
370 }
371
372 boolean isAccessible(Env<AttrContext> env, Type t) {
373 return isAccessible(env, t, false);
374 }
375
376 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) {
377 return (t.hasTag(ARRAY))
378 ? isAccessible(env, types.cvarUpperBound(types.elemtype(t)))
379 : isAccessible(env, t.tsym, checkInner);
380 }
381
382 /** Is symbol accessible as a member of given type in given environment?
383 * @param env The current environment.
384 * @param site The type of which the tested symbol is regarded
385 * as a member.
386 * @param sym The symbol.
387 */
388 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
389 return isAccessible(env, site, sym, false);
390 }
391 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) {
392 if (sym.name == names.init && sym.owner != site.tsym) return false;
393
394 /* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor
395 to refer to an inaccessible type
396 */
397 if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0)
398 return true;
399
400 if (env.info.visitingServiceImplementation &&
401 env.toplevel.modle == sym.packge().modle) {
402 return true;
403 }
404
405 switch ((short)(sym.flags() & AccessFlags)) {
406 case PRIVATE:
407 return
408 (env.enclClass.sym == sym.owner // fast special case
409 ||
410 env.enclClass.sym.outermostClass() ==
411 sym.owner.outermostClass())
412 &&
413 sym.isInheritedIn(site.tsym, types);
414 case 0:
415 return
416 (env.toplevel.packge == sym.owner.owner // fast special case
417 ||
418 env.toplevel.packge == sym.packge())
419 &&
420 isAccessible(env, site, checkInner)
421 &&
422 sym.isInheritedIn(site.tsym, types)
423 &&
424 notOverriddenIn(site, sym);
425 case PROTECTED:
426 return
427 (env.toplevel.packge == sym.owner.owner // fast special case
428 ||
429 env.toplevel.packge == sym.packge()
430 ||
431 isProtectedAccessible(sym, env.enclClass.sym, site)
432 ||
433 // OK to select instance method or field from 'super' or type name
434 // (but type names should be disallowed elsewhere!)
435 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
436 &&
437 isAccessible(env, site, checkInner)
438 &&
439 notOverriddenIn(site, sym);
440 default: // this case includes erroneous combinations as well
441 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
442 }
443 }
444 //where
445 /* `sym' is accessible only if not overridden by
446 * another symbol which is a member of `site'
447 * (because, if it is overridden, `sym' is not strictly
448 * speaking a member of `site'). A polymorphic signature method
449 * cannot be overridden (e.g. MH.invokeExact(Object[])).
450 */
451 private boolean notOverriddenIn(Type site, Symbol sym) {
452 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
453 return true;
454 else {
455 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
456 return (s2 == null || s2 == sym || sym.owner == s2.owner ||
457 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
458 }
459 }
460 //where
461 /** Is given protected symbol accessible if it is selected from given site
462 * and the selection takes place in given class?
463 * @param sym The symbol with protected access
464 * @param c The class where the access takes place
465 * @site The type of the qualifier
466 */
467 private
468 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
469 Type newSite = site.hasTag(TYPEVAR) ? site.getUpperBound() : site;
470 while (c != null &&
471 !(c.isSubClass(sym.owner, types) &&
472 (c.flags() & INTERFACE) == 0 &&
473 // In JLS 2e 6.6.2.1, the subclass restriction applies
474 // only to instance fields and methods -- types are excluded
475 // regardless of whether they are declared 'static' or not.
476 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || newSite.tsym.isSubClass(c, types))))
477 c = c.owner.enclClass();
478 return c != null;
479 }
480
481 /**
482 * Performs a recursive scan of a type looking for accessibility problems
483 * from current attribution environment
484 */
485 void checkAccessibleType(Env<AttrContext> env, Type t) {
486 accessibilityChecker.visit(t, env);
487 }
488
489 /**
490 * Accessibility type-visitor
491 */
492 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker =
493 new Types.SimpleVisitor<Void, Env<AttrContext>>() {
494
495 void visit(List<Type> ts, Env<AttrContext> env) {
496 for (Type t : ts) {
497 visit(t, env);
498 }
499 }
500
501 public Void visitType(Type t, Env<AttrContext> env) {
502 return null;
503 }
504
505 @Override
506 public Void visitArrayType(ArrayType t, Env<AttrContext> env) {
507 visit(t.elemtype, env);
508 return null;
509 }
510
511 @Override
512 public Void visitClassType(ClassType t, Env<AttrContext> env) {
513 visit(t.getTypeArguments(), env);
514 if (!isAccessible(env, t, true)) {
515 accessBase(new AccessError(env, null, t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true);
516 }
517 return null;
518 }
519
520 @Override
521 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) {
522 visit(t.type, env);
523 return null;
524 }
525
526 @Override
527 public Void visitMethodType(MethodType t, Env<AttrContext> env) {
528 visit(t.getParameterTypes(), env);
529 visit(t.getReturnType(), env);
530 visit(t.getThrownTypes(), env);
531 return null;
532 }
533 };
534
535 /** Try to instantiate the type of a method so that it fits
536 * given type arguments and argument types. If successful, return
537 * the method's instantiated type, else return null.
538 * The instantiation will take into account an additional leading
539 * formal parameter if the method is an instance method seen as a member
540 * of an under determined site. In this case, we treat site as an additional
541 * parameter and the parameters of the class containing the method as
542 * additional type variables that get instantiated.
543 *
544 * @param env The current environment
545 * @param site The type of which the method is a member.
546 * @param m The method symbol.
547 * @param argtypes The invocation's given value arguments.
548 * @param typeargtypes The invocation's given type arguments.
549 * @param allowBoxing Allow boxing conversions of arguments.
550 * @param useVarargs Box trailing arguments into an array for varargs.
551 */
552 Type rawInstantiate(Env<AttrContext> env,
553 Type site,
554 Symbol m,
555 ResultInfo resultInfo,
556 List<Type> argtypes,
557 List<Type> typeargtypes,
558 boolean allowBoxing,
559 boolean useVarargs,
560 Warner warn) throws Infer.InferenceException {
561 Type mt = types.memberType(site, m);
562 // tvars is the list of formal type variables for which type arguments
563 // need to inferred.
564 List<Type> tvars = List.nil();
565 if (typeargtypes == null) typeargtypes = List.nil();
566 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
567 // This is not a polymorphic method, but typeargs are supplied
568 // which is fine, see JLS 15.12.2.1
569 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
570 ForAll pmt = (ForAll) mt;
571 if (typeargtypes.length() != pmt.tvars.length())
572 // not enough args
573 throw new InapplicableMethodException(diags.fragment(Fragments.WrongNumberTypeArgs(Integer.toString(pmt.tvars.length()))));
574 // Check type arguments are within bounds
575 List<Type> formals = pmt.tvars;
576 List<Type> actuals = typeargtypes;
577 while (formals.nonEmpty() && actuals.nonEmpty()) {
578 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
579 pmt.tvars, typeargtypes);
580 for (; bounds.nonEmpty(); bounds = bounds.tail) {
581 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn)) {
582 throw new InapplicableMethodException(diags.fragment(Fragments.ExplicitParamDoNotConformToBounds(actuals.head, bounds)));
583 }
584 }
585 formals = formals.tail;
586 actuals = actuals.tail;
587 }
588 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
589 } else if (mt.hasTag(FORALL)) {
590 ForAll pmt = (ForAll) mt;
591 List<Type> tvars1 = types.newInstances(pmt.tvars);
592 tvars = tvars.appendList(tvars1);
593 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
594 }
595
596 // find out whether we need to go the slow route via infer
597 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/
598 for (List<Type> l = argtypes;
599 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
600 l = l.tail) {
601 if (l.head.hasTag(FORALL)) instNeeded = true;
602 }
603
604 if (instNeeded) {
605 return infer.instantiateMethod(env,
606 tvars,
607 (MethodType)mt,
608 resultInfo,
609 (MethodSymbol)m,
610 argtypes,
611 allowBoxing,
612 useVarargs,
613 currentResolutionContext,
614 warn);
615 }
616
617 DeferredAttr.DeferredAttrContext dc = currentResolutionContext.deferredAttrContext(m, infer.emptyContext, resultInfo, warn);
618 currentResolutionContext.methodCheck.argumentsAcceptable(env, dc,
619 argtypes, mt.getParameterTypes(), warn);
620 dc.complete();
621 return mt;
622 }
623
624 Type checkMethod(Env<AttrContext> env,
625 Type site,
626 Symbol m,
627 ResultInfo resultInfo,
628 List<Type> argtypes,
629 List<Type> typeargtypes,
630 Warner warn) {
631 MethodResolutionContext prevContext = currentResolutionContext;
632 try {
633 currentResolutionContext = new MethodResolutionContext();
634 currentResolutionContext.attrMode = (resultInfo.pt == Infer.anyPoly) ?
635 AttrMode.SPECULATIVE : DeferredAttr.AttrMode.CHECK;
636 if (env.tree.hasTag(JCTree.Tag.REFERENCE)) {
637 //method/constructor references need special check class
638 //to handle inference variables in 'argtypes' (might happen
639 //during an unsticking round)
640 currentResolutionContext.methodCheck =
641 new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
642 }
643 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase;
644 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
645 step.isBoxingRequired(), step.isVarargsRequired(), warn);
646 }
647 finally {
648 currentResolutionContext = prevContext;
649 }
650 }
651
652 /** Same but returns null instead throwing a NoInstanceException
653 */
654 Type instantiate(Env<AttrContext> env,
655 Type site,
656 Symbol m,
657 ResultInfo resultInfo,
658 List<Type> argtypes,
659 List<Type> typeargtypes,
660 boolean allowBoxing,
661 boolean useVarargs,
662 Warner warn) {
663 try {
664 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
665 allowBoxing, useVarargs, warn);
666 } catch (InapplicableMethodException ex) {
667 return null;
668 }
669 }
670
671 /**
672 * This interface defines an entry point that should be used to perform a
673 * method check. A method check usually consist in determining as to whether
674 * a set of types (actuals) is compatible with another set of types (formals).
675 * Since the notion of compatibility can vary depending on the circumstances,
676 * this interfaces allows to easily add new pluggable method check routines.
677 */
678 interface MethodCheck {
679 /**
680 * Main method check routine. A method check usually consist in determining
681 * as to whether a set of types (actuals) is compatible with another set of
682 * types (formals). If an incompatibility is found, an unchecked exception
683 * is assumed to be thrown.
684 */
685 void argumentsAcceptable(Env<AttrContext> env,
686 DeferredAttrContext deferredAttrContext,
687 List<Type> argtypes,
688 List<Type> formals,
689 Warner warn);
690
691 /**
692 * Retrieve the method check object that will be used during a
693 * most specific check.
694 */
695 MethodCheck mostSpecificCheck(List<Type> actuals);
696 }
697
698 /**
699 * Helper enum defining all method check diagnostics (used by resolveMethodCheck).
700 */
701 enum MethodCheckDiag {
702 /**
703 * Actuals and formals differs in length.
704 */
705 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"),
706 /**
707 * An actual is incompatible with a formal.
708 */
709 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"),
710 /**
711 * An actual is incompatible with the varargs element type.
712 */
713 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"),
714 /**
715 * The varargs element type is inaccessible.
716 */
717 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type");
718
719 final String basicKey;
720 final String inferKey;
721
722 MethodCheckDiag(String basicKey, String inferKey) {
723 this.basicKey = basicKey;
724 this.inferKey = inferKey;
725 }
726
727 String regex() {
728 return String.format("([a-z]*\\.)*(%s|%s)", basicKey, inferKey);
729 }
730 }
731
732 /**
733 * Dummy method check object. All methods are deemed applicable, regardless
734 * of their formal parameter types.
735 */
736 MethodCheck nilMethodCheck = new MethodCheck() {
737 public void argumentsAcceptable(Env<AttrContext> env, DeferredAttrContext deferredAttrContext, List<Type> argtypes, List<Type> formals, Warner warn) {
738 //do nothing - method always applicable regardless of actuals
739 }
740
741 public MethodCheck mostSpecificCheck(List<Type> actuals) {
742 return this;
743 }
744 };
745
746 /**
747 * Base class for 'real' method checks. The class defines the logic for
748 * iterating through formals and actuals and provides and entry point
749 * that can be used by subclasses in order to define the actual check logic.
750 */
751 abstract class AbstractMethodCheck implements MethodCheck {
752 @Override
753 public void argumentsAcceptable(final Env<AttrContext> env,
754 DeferredAttrContext deferredAttrContext,
755 List<Type> argtypes,
756 List<Type> formals,
757 Warner warn) {
758 //should we expand formals?
759 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired();
760 JCTree callTree = treeForDiagnostics(env);
761 List<JCExpression> trees = TreeInfo.args(callTree);
762
763 //inference context used during this method check
764 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
765
766 Type varargsFormal = useVarargs ? formals.last() : null;
767
768 if (varargsFormal == null &&
769 argtypes.size() != formals.size()) {
770 reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
771 }
772
773 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
774 DiagnosticPosition pos = trees != null ? trees.head : null;
775 checkArg(pos, false, argtypes.head, formals.head, deferredAttrContext, warn);
776 argtypes = argtypes.tail;
777 formals = formals.tail;
778 trees = trees != null ? trees.tail : trees;
779 }
780
781 if (formals.head != varargsFormal) {
782 reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
783 }
784
785 if (useVarargs) {
786 //note: if applicability check is triggered by most specific test,
787 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
788 final Type elt = types.elemtype(varargsFormal);
789 while (argtypes.nonEmpty()) {
790 DiagnosticPosition pos = trees != null ? trees.head : null;
791 checkArg(pos, true, argtypes.head, elt, deferredAttrContext, warn);
792 argtypes = argtypes.tail;
793 trees = trees != null ? trees.tail : trees;
794 }
795 }
796 }
797
798 // where
799 private JCTree treeForDiagnostics(Env<AttrContext> env) {
800 return env.info.preferredTreeForDiagnostics != null ? env.info.preferredTreeForDiagnostics : env.tree;
801 }
802
803 /**
804 * Does the actual argument conforms to the corresponding formal?
805 */
806 abstract void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn);
807
808 protected void reportMC(DiagnosticPosition pos, MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
809 boolean inferDiag = inferenceContext != infer.emptyContext;
810 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) {
811 Object[] args2 = new Object[args.length + 1];
812 System.arraycopy(args, 0, args2, 1, args.length);
813 args2[0] = inferenceContext.inferenceVars();
814 args = args2;
815 }
816 String key = inferDiag ? diag.inferKey : diag.basicKey;
817 throw inferDiag ?
818 infer.error(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args)) :
819 methodCheckFailure.setMessage(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args));
820 }
821
822 /**
823 * To eliminate the overhead associated with allocating an exception object in such an
824 * hot execution path, we use flyweight pattern - and share the same exception instance
825 * across multiple method check failures.
826 */
827 class SharedInapplicableMethodException extends InapplicableMethodException {
828 private static final long serialVersionUID = 0;
829
830 SharedInapplicableMethodException() {
831 super(null);
832 }
833
834 SharedInapplicableMethodException setMessage(JCDiagnostic details) {
835 this.diagnostic = details;
836 return this;
837 }
838 }
839
840 SharedInapplicableMethodException methodCheckFailure = new SharedInapplicableMethodException();
841
842 public MethodCheck mostSpecificCheck(List<Type> actuals) {
843 return nilMethodCheck;
844 }
845
846 }
847
848 /**
849 * Arity-based method check. A method is applicable if the number of actuals
850 * supplied conforms to the method signature.
851 */
852 MethodCheck arityMethodCheck = new AbstractMethodCheck() {
853 @Override
854 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
855 //do nothing - actual always compatible to formals
856 }
857
858 @Override
859 public String toString() {
860 return "arityMethodCheck";
861 }
862 };
863
864 /**
865 * Main method applicability routine. Given a list of actual types A,
866 * a list of formal types F, determines whether the types in A are
867 * compatible (by method invocation conversion) with the types in F.
868 *
869 * Since this routine is shared between overload resolution and method
870 * type-inference, a (possibly empty) inference context is used to convert
871 * formal types to the corresponding 'undet' form ahead of a compatibility
872 * check so that constraints can be propagated and collected.
873 *
874 * Moreover, if one or more types in A is a deferred type, this routine uses
875 * DeferredAttr in order to perform deferred attribution. If one or more actual
876 * deferred types are stuck, they are placed in a queue and revisited later
877 * after the remainder of the arguments have been seen. If this is not sufficient
878 * to 'unstuck' the argument, a cyclic inference error is called out.
879 *
880 * A method check handler (see above) is used in order to report errors.
881 */
882 MethodCheck resolveMethodCheck = new AbstractMethodCheck() {
883
884 @Override
885 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
886 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
887 mresult.check(pos, actual);
888 }
889
890 @Override
891 public void argumentsAcceptable(final Env<AttrContext> env,
892 DeferredAttrContext deferredAttrContext,
893 List<Type> argtypes,
894 List<Type> formals,
895 Warner warn) {
896 super.argumentsAcceptable(env, deferredAttrContext, argtypes, formals, warn);
897 // should we check varargs element type accessibility?
898 if (deferredAttrContext.phase.isVarargsRequired()) {
899 if (deferredAttrContext.mode == AttrMode.CHECK || !checkVarargsAccessAfterResolution) {
900 varargsAccessible(env, types.elemtype(formals.last()), deferredAttrContext.inferenceContext);
901 }
902 }
903 }
904
905 /**
906 * Test that the runtime array element type corresponding to 't' is accessible. 't' should be the
907 * varargs element type of either the method invocation type signature (after inference completes)
908 * or the method declaration signature (before inference completes).
909 */
910 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) {
911 if (inferenceContext.free(t)) {
912 inferenceContext.addFreeTypeListener(List.of(t),
913 solvedContext -> varargsAccessible(env, solvedContext.asInstType(t), solvedContext));
914 } else {
915 if (!isAccessible(env, types.erasure(t))) {
916 Symbol location = env.enclClass.sym;
917 reportMC(env.tree, MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
918 }
919 }
920 }
921
922 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
923 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
924 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
925 MethodCheckDiag methodDiag = varargsCheck ?
926 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
927
928 @Override
929 public void report(DiagnosticPosition pos, JCDiagnostic details) {
930 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
931 }
932 };
933 return new MethodResultInfo(to, checkContext);
934 }
935
936 @Override
937 public MethodCheck mostSpecificCheck(List<Type> actuals) {
938 return new MostSpecificCheck(actuals);
939 }
940
941 @Override
942 public String toString() {
943 return "resolveMethodCheck";
944 }
945 };
946
947 /**
948 * This class handles method reference applicability checks; since during
949 * these checks it's sometime possible to have inference variables on
950 * the actual argument types list, the method applicability check must be
951 * extended so that inference variables are 'opened' as needed.
952 */
953 class MethodReferenceCheck extends AbstractMethodCheck {
954
955 InferenceContext pendingInferenceContext;
956
957 MethodReferenceCheck(InferenceContext pendingInferenceContext) {
958 this.pendingInferenceContext = pendingInferenceContext;
959 }
960
961 @Override
962 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
963 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
964 mresult.check(pos, actual);
965 }
966
967 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
968 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
969 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
970 MethodCheckDiag methodDiag = varargsCheck ?
971 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
972
973 @Override
974 public boolean compatible(Type found, Type req, Warner warn) {
975 found = pendingInferenceContext.asUndetVar(found);
976 if (found.hasTag(UNDETVAR) && req.isPrimitive()) {
977 req = types.boxedClass(req).type;
978 }
979 return super.compatible(found, req, warn);
980 }
981
982 @Override
983 public void report(DiagnosticPosition pos, JCDiagnostic details) {
984 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
985 }
986 };
987 return new MethodResultInfo(to, checkContext);
988 }
989
990 @Override
991 public MethodCheck mostSpecificCheck(List<Type> actuals) {
992 return new MostSpecificCheck(actuals);
993 }
994
995 @Override
996 public String toString() {
997 return "MethodReferenceCheck";
998 }
999 }
1000
1001 /**
1002 * Check context to be used during method applicability checks. A method check
1003 * context might contain inference variables.
1004 */
1005 abstract class MethodCheckContext implements CheckContext {
1006
1007 boolean strict;
1008 DeferredAttrContext deferredAttrContext;
1009 Warner rsWarner;
1010
1011 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) {
1012 this.strict = strict;
1013 this.deferredAttrContext = deferredAttrContext;
1014 this.rsWarner = rsWarner;
1015 }
1016
1017 public boolean compatible(Type found, Type req, Warner warn) {
1018 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
1019 return strict ?
1020 types.isSubtypeUnchecked(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn) :
1021 types.isConvertible(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn);
1022 }
1023
1024 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1025 throw new InapplicableMethodException(details);
1026 }
1027
1028 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
1029 return rsWarner;
1030 }
1031
1032 public InferenceContext inferenceContext() {
1033 return deferredAttrContext.inferenceContext;
1034 }
1035
1036 public DeferredAttrContext deferredAttrContext() {
1037 return deferredAttrContext;
1038 }
1039
1040 @Override
1041 public String toString() {
1042 return "MethodCheckContext";
1043 }
1044 }
1045
1046 /**
1047 * ResultInfo class to be used during method applicability checks. Check
1048 * for deferred types goes through special path.
1049 */
1050 class MethodResultInfo extends ResultInfo {
1051
1052 public MethodResultInfo(Type pt, CheckContext checkContext) {
1053 attr.super(KindSelector.VAL, pt, checkContext);
1054 }
1055
1056 @Override
1057 protected Type check(DiagnosticPosition pos, Type found) {
1058 if (found.hasTag(DEFERRED)) {
1059 DeferredType dt = (DeferredType)found;
1060 return dt.check(this);
1061 } else {
1062 Type uResult = U(found);
1063 Type capturedType = pos == null || pos.getTree() == null ?
1064 types.capture(uResult) :
1065 checkContext.inferenceContext()
1066 .cachedCapture(pos.getTree(), uResult, true);
1067 return super.check(pos, chk.checkNonVoid(pos, capturedType));
1068 }
1069 }
1070
1071 /**
1072 * javac has a long-standing 'simplification' (see 6391995):
1073 * given an actual argument type, the method check is performed
1074 * on its upper bound. This leads to inconsistencies when an
1075 * argument type is checked against itself. For example, given
1076 * a type-variable T, it is not true that {@code U(T) <: T},
1077 * so we need to guard against that.
1078 */
1079 private Type U(Type found) {
1080 return found == pt ?
1081 found : types.cvarUpperBound(found);
1082 }
1083
1084 @Override
1085 protected MethodResultInfo dup(Type newPt) {
1086 return new MethodResultInfo(newPt, checkContext);
1087 }
1088
1089 @Override
1090 protected ResultInfo dup(CheckContext newContext) {
1091 return new MethodResultInfo(pt, newContext);
1092 }
1093
1094 @Override
1095 protected ResultInfo dup(Type newPt, CheckContext newContext) {
1096 return new MethodResultInfo(newPt, newContext);
1097 }
1098 }
1099
1100 /**
1101 * Most specific method applicability routine. Given a list of actual types A,
1102 * a list of formal types F1, and a list of formal types F2, the routine determines
1103 * as to whether the types in F1 can be considered more specific than those in F2 w.r.t.
1104 * argument types A.
1105 */
1106 class MostSpecificCheck implements MethodCheck {
1107
1108 List<Type> actuals;
1109
1110 MostSpecificCheck(List<Type> actuals) {
1111 this.actuals = actuals;
1112 }
1113
1114 @Override
1115 public void argumentsAcceptable(final Env<AttrContext> env,
1116 DeferredAttrContext deferredAttrContext,
1117 List<Type> formals1,
1118 List<Type> formals2,
1119 Warner warn) {
1120 formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired());
1121 while (formals2.nonEmpty()) {
1122 ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head);
1123 mresult.check(null, formals1.head);
1124 formals1 = formals1.tail;
1125 formals2 = formals2.tail;
1126 actuals = actuals.isEmpty() ? actuals : actuals.tail;
1127 }
1128 }
1129
1130 /**
1131 * Create a method check context to be used during the most specific applicability check
1132 */
1133 ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext,
1134 Warner rsWarner, Type actual) {
1135 return attr.new ResultInfo(KindSelector.VAL, to,
1136 new MostSpecificCheckContext(deferredAttrContext, rsWarner, actual));
1137 }
1138
1139 /**
1140 * Subclass of method check context class that implements most specific
1141 * method conversion. If the actual type under analysis is a deferred type
1142 * a full blown structural analysis is carried out.
1143 */
1144 class MostSpecificCheckContext extends MethodCheckContext {
1145
1146 Type actual;
1147
1148 public MostSpecificCheckContext(DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) {
1149 super(true, deferredAttrContext, rsWarner);
1150 this.actual = actual;
1151 }
1152
1153 public boolean compatible(Type found, Type req, Warner warn) {
1154 if (allowFunctionalInterfaceMostSpecific &&
1155 unrelatedFunctionalInterfaces(found, req) &&
1156 (actual != null && actual.getTag() == DEFERRED)) {
1157 DeferredType dt = (DeferredType) actual;
1158 JCTree speculativeTree = dt.speculativeTree(deferredAttrContext);
1159 if (speculativeTree != deferredAttr.stuckTree) {
1160 return functionalInterfaceMostSpecific(found, req, speculativeTree);
1161 }
1162 }
1163 return compatibleBySubtyping(found, req);
1164 }
1165
1166 private boolean compatibleBySubtyping(Type found, Type req) {
1167 if (!strict && found.isPrimitive() != req.isPrimitive()) {
1168 found = found.isPrimitive() ? types.boxedClass(found).type : types.unboxedType(found);
1169 }
1170 return types.isSubtypeNoCapture(found, deferredAttrContext.inferenceContext.asUndetVar(req));
1171 }
1172
1173 /** Whether {@code t} and {@code s} are unrelated functional interface types. */
1174 private boolean unrelatedFunctionalInterfaces(Type t, Type s) {
1175 return types.isFunctionalInterface(t.tsym) &&
1176 types.isFunctionalInterface(s.tsym) &&
1177 unrelatedInterfaces(t, s);
1178 }
1179
1180 /** Whether {@code t} and {@code s} are unrelated interface types; recurs on intersections. **/
1181 private boolean unrelatedInterfaces(Type t, Type s) {
1182 if (t.isCompound()) {
1183 for (Type ti : types.interfaces(t)) {
1184 if (!unrelatedInterfaces(ti, s)) {
1185 return false;
1186 }
1187 }
1188 return true;
1189 } else if (s.isCompound()) {
1190 for (Type si : types.interfaces(s)) {
1191 if (!unrelatedInterfaces(t, si)) {
1192 return false;
1193 }
1194 }
1195 return true;
1196 } else {
1197 return types.asSuper(t, s.tsym) == null && types.asSuper(s, t.tsym) == null;
1198 }
1199 }
1200
1201 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */
1202 private boolean functionalInterfaceMostSpecific(Type t, Type s, JCTree tree) {
1203 Type tDesc = types.findDescriptorType(types.capture(t));
1204 Type tDescNoCapture = types.findDescriptorType(t);
1205 Type sDesc = types.findDescriptorType(s);
1206 final List<Type> tTypeParams = tDesc.getTypeArguments();
1207 final List<Type> tTypeParamsNoCapture = tDescNoCapture.getTypeArguments();
1208 final List<Type> sTypeParams = sDesc.getTypeArguments();
1209
1210 // compare type parameters
1211 if (tDesc.hasTag(FORALL) && !types.hasSameBounds((ForAll) tDesc, (ForAll) tDescNoCapture)) {
1212 return false;
1213 }
1214 // can't use Types.hasSameBounds on sDesc because bounds may have ivars
1215 List<Type> tIter = tTypeParams;
1216 List<Type> sIter = sTypeParams;
1217 while (tIter.nonEmpty() && sIter.nonEmpty()) {
1218 Type tBound = tIter.head.getUpperBound();
1219 Type sBound = types.subst(sIter.head.getUpperBound(), sTypeParams, tTypeParams);
1220 if (tBound.containsAny(tTypeParams) && inferenceContext().free(sBound)) {
1221 return false;
1222 }
1223 if (!types.isSameType(tBound, inferenceContext().asUndetVar(sBound))) {
1224 return false;
1225 }
1226 tIter = tIter.tail;
1227 sIter = sIter.tail;
1228 }
1229 if (!tIter.isEmpty() || !sIter.isEmpty()) {
1230 return false;
1231 }
1232
1233 // compare parameters
1234 List<Type> tParams = tDesc.getParameterTypes();
1235 List<Type> tParamsNoCapture = tDescNoCapture.getParameterTypes();
1236 List<Type> sParams = sDesc.getParameterTypes();
1237 while (tParams.nonEmpty() && tParamsNoCapture.nonEmpty() && sParams.nonEmpty()) {
1238 Type tParam = tParams.head;
1239 Type tParamNoCapture = types.subst(tParamsNoCapture.head, tTypeParamsNoCapture, tTypeParams);
1240 Type sParam = types.subst(sParams.head, sTypeParams, tTypeParams);
1241 if (tParam.containsAny(tTypeParams) && inferenceContext().free(sParam)) {
1242 return false;
1243 }
1244 if (!types.isSubtype(inferenceContext().asUndetVar(sParam), tParam)) {
1245 return false;
1246 }
1247 if (!types.isSameType(tParamNoCapture, inferenceContext().asUndetVar(sParam))) {
1248 return false;
1249 }
1250 tParams = tParams.tail;
1251 tParamsNoCapture = tParamsNoCapture.tail;
1252 sParams = sParams.tail;
1253 }
1254 if (!tParams.isEmpty() || !tParamsNoCapture.isEmpty() || !sParams.isEmpty()) {
1255 return false;
1256 }
1257
1258 // compare returns
1259 Type tRet = tDesc.getReturnType();
1260 Type sRet = types.subst(sDesc.getReturnType(), sTypeParams, tTypeParams);
1261 if (tRet.containsAny(tTypeParams) && inferenceContext().free(sRet)) {
1262 return false;
1263 }
1264 MostSpecificFunctionReturnChecker msc = new MostSpecificFunctionReturnChecker(tRet, sRet);
1265 msc.scan(tree);
1266 return msc.result;
1267 }
1268
1269 /**
1270 * Tests whether one functional interface type can be considered more specific
1271 * than another unrelated functional interface type for the scanned expression.
1272 */
1273 class MostSpecificFunctionReturnChecker extends DeferredAttr.PolyScanner {
1274
1275 final Type tRet;
1276 final Type sRet;
1277 boolean result;
1278
1279 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */
1280 MostSpecificFunctionReturnChecker(Type tRet, Type sRet) {
1281 this.tRet = tRet;
1282 this.sRet = sRet;
1283 result = true;
1284 }
1285
1286 @Override
1287 void skip(JCTree tree) {
1288 result &= false;
1289 }
1290
1291 @Override
1292 public void visitConditional(JCConditional tree) {
1293 scan(asExpr(tree.truepart));
1294 scan(asExpr(tree.falsepart));
1295 }
1296
1297 @Override
1298 public void visitReference(JCMemberReference tree) {
1299 if (sRet.hasTag(VOID)) {
1300 result &= true;
1301 } else if (tRet.hasTag(VOID)) {
1302 result &= false;
1303 } else if (tRet.isPrimitive() != sRet.isPrimitive()) {
1304 boolean retValIsPrimitive =
1305 tree.refPolyKind == PolyKind.STANDALONE &&
1306 tree.sym.type.getReturnType().isPrimitive();
1307 result &= (retValIsPrimitive == tRet.isPrimitive()) &&
1308 (retValIsPrimitive != sRet.isPrimitive());
1309 } else {
1310 result &= compatibleBySubtyping(tRet, sRet);
1311 }
1312 }
1313
1314 @Override
1315 public void visitParens(JCParens tree) {
1316 scan(asExpr(tree.expr));
1317 }
1318
1319 @Override
1320 public void visitLambda(JCLambda tree) {
1321 if (sRet.hasTag(VOID)) {
1322 result &= true;
1323 } else if (tRet.hasTag(VOID)) {
1324 result &= false;
1325 } else {
1326 List<JCExpression> lambdaResults = lambdaResults(tree);
1327 if (!lambdaResults.isEmpty() && unrelatedFunctionalInterfaces(tRet, sRet)) {
1328 for (JCExpression expr : lambdaResults) {
1329 result &= functionalInterfaceMostSpecific(tRet, sRet, expr);
1330 }
1331 } else if (!lambdaResults.isEmpty() && tRet.isPrimitive() != sRet.isPrimitive()) {
1332 for (JCExpression expr : lambdaResults) {
1333 boolean retValIsPrimitive = expr.isStandalone() && expr.type.isPrimitive();
1334 result &= (retValIsPrimitive == tRet.isPrimitive()) &&
1335 (retValIsPrimitive != sRet.isPrimitive());
1336 }
1337 } else {
1338 result &= compatibleBySubtyping(tRet, sRet);
1339 }
1340 }
1341 }
1342 //where
1343
1344 private List<JCExpression> lambdaResults(JCLambda lambda) {
1345 if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) {
1346 return List.of(asExpr((JCExpression) lambda.body));
1347 } else {
1348 final ListBuffer<JCExpression> buffer = new ListBuffer<>();
1349 DeferredAttr.LambdaReturnScanner lambdaScanner =
1350 new DeferredAttr.LambdaReturnScanner() {
1351 @Override
1352 public void visitReturn(JCReturn tree) {
1353 if (tree.expr != null) {
1354 buffer.append(asExpr(tree.expr));
1355 }
1356 }
1357 };
1358 lambdaScanner.scan(lambda.body);
1359 return buffer.toList();
1360 }
1361 }
1362
1363 private JCExpression asExpr(JCExpression expr) {
1364 if (expr.type.hasTag(DEFERRED)) {
1365 JCTree speculativeTree = ((DeferredType)expr.type).speculativeTree(deferredAttrContext);
1366 if (speculativeTree != deferredAttr.stuckTree) {
1367 expr = (JCExpression)speculativeTree;
1368 }
1369 }
1370 return expr;
1371 }
1372 }
1373
1374 }
1375
1376 public MethodCheck mostSpecificCheck(List<Type> actuals) {
1377 Assert.error("Cannot get here!");
1378 return null;
1379 }
1380 }
1381
1382 public static class InapplicableMethodException extends RuntimeException {
1383 private static final long serialVersionUID = 0;
1384
1385 JCDiagnostic diagnostic;
1386
1387 InapplicableMethodException(JCDiagnostic diag) {
1388 this.diagnostic = diag;
1389 }
1390
1391 public JCDiagnostic getDiagnostic() {
1392 return diagnostic;
1393 }
1394 }
1395
1396 /* ***************************************************************************
1397 * Symbol lookup
1398 * the following naming conventions for arguments are used
1399 *
1400 * env is the environment where the symbol was mentioned
1401 * site is the type of which the symbol is a member
1402 * name is the symbol's name
1403 * if no arguments are given
1404 * argtypes are the value arguments, if we search for a method
1405 *
1406 * If no symbol was found, a ResolveError detailing the problem is returned.
1407 ****************************************************************************/
1408
1409 /** Find field. Synthetic fields are always skipped.
1410 * @param env The current environment.
1411 * @param site The original type from where the selection takes place.
1412 * @param name The name of the field.
1413 * @param c The class to search for the field. This is always
1414 * a superclass or implemented interface of site's class.
1415 */
1416 Symbol findField(Env<AttrContext> env,
1417 Type site,
1418 Name name,
1419 TypeSymbol c) {
1420 while (c.type.hasTag(TYPEVAR))
1421 c = c.type.getUpperBound().tsym;
1422 Symbol bestSoFar = varNotFound;
1423 Symbol sym;
1424 for (Symbol s : c.members().getSymbolsByName(name)) {
1425 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) {
1426 return isAccessible(env, site, s)
1427 ? s : new AccessError(env, site, s);
1428 }
1429 }
1430 Type st = types.supertype(c.type);
1431 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) {
1432 sym = findField(env, site, name, st.tsym);
1433 bestSoFar = bestOf(bestSoFar, sym);
1434 }
1435 for (List<Type> l = types.interfaces(c.type);
1436 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1437 l = l.tail) {
1438 sym = findField(env, site, name, l.head.tsym);
1439 if (bestSoFar.exists() && sym.exists() &&
1440 sym.owner != bestSoFar.owner)
1441 bestSoFar = new AmbiguityError(bestSoFar, sym);
1442 else
1443 bestSoFar = bestOf(bestSoFar, sym);
1444 }
1445 return bestSoFar;
1446 }
1447
1448 /** Resolve a field identifier, throw a fatal error if not found.
1449 * @param pos The position to use for error reporting.
1450 * @param env The environment current at the method invocation.
1451 * @param site The type of the qualifying expression, in which
1452 * identifier is searched.
1453 * @param name The identifier's name.
1454 */
1455 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
1456 Type site, Name name) {
1457 Symbol sym = findField(env, site, name, site.tsym);
1458 if (sym.kind == VAR) return (VarSymbol)sym;
1459 else throw new FatalError(
1460 diags.fragment(Fragments.FatalErrCantLocateField(name)));
1461 }
1462
1463 /** Find unqualified variable or field with given name.
1464 * Synthetic fields always skipped.
1465 * @param env The current environment.
1466 * @param name The name of the variable or field.
1467 */
1468 Symbol findVar(Env<AttrContext> env, Name name) {
1469 Symbol bestSoFar = varNotFound;
1470 Env<AttrContext> env1 = env;
1471 boolean staticOnly = false;
1472 while (env1.outer != null) {
1473 Symbol sym = null;
1474 if (isStatic(env1)) staticOnly = true;
1475 for (Symbol s : env1.info.scope.getSymbolsByName(name)) {
1476 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) {
1477 sym = s;
1478 break;
1479 }
1480 }
1481 if (sym == null) {
1482 sym = findField(env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
1483 }
1484 if (sym.exists()) {
1485 if (staticOnly &&
1486 sym.kind == VAR &&
1487 sym.owner.kind == TYP &&
1488 (sym.flags() & STATIC) == 0)
1489 return new StaticError(sym);
1490 else
1491 return sym;
1492 } else {
1493 bestSoFar = bestOf(bestSoFar, sym);
1494 }
1495
1496 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1497 env1 = env1.outer;
1498 }
1499
1500 Symbol sym = findField(env, syms.predefClass.type, name, syms.predefClass);
1501 if (sym.exists())
1502 return sym;
1503 if (bestSoFar.exists())
1504 return bestSoFar;
1505
1506 Symbol origin = null;
1507 for (Scope sc : new Scope[] { env.toplevel.namedImportScope, env.toplevel.starImportScope }) {
1508 for (Symbol currentSymbol : sc.getSymbolsByName(name)) {
1509 if (currentSymbol.kind != VAR)
1510 continue;
1511 // invariant: sym.kind == Symbol.Kind.VAR
1512 if (!bestSoFar.kind.isResolutionError() &&
1513 currentSymbol.owner != bestSoFar.owner)
1514 return new AmbiguityError(bestSoFar, currentSymbol);
1515 else if (!bestSoFar.kind.betterThan(VAR)) {
1516 origin = sc.getOrigin(currentSymbol).owner;
1517 bestSoFar = isAccessible(env, origin.type, currentSymbol)
1518 ? currentSymbol : new AccessError(env, origin.type, currentSymbol);
1519 }
1520 }
1521 if (bestSoFar.exists()) break;
1522 }
1523 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
1524 return bestSoFar.clone(origin);
1525 else
1526 return bestSoFar;
1527 }
1528
1529 Warner noteWarner = new Warner();
1530
1531 /** Select the best method for a call site among two choices.
1532 * @param env The current environment.
1533 * @param site The original type from where the
1534 * selection takes place.
1535 * @param argtypes The invocation's value arguments,
1536 * @param typeargtypes The invocation's type arguments,
1537 * @param sym Proposed new best match.
1538 * @param bestSoFar Previously found best match.
1539 * @param allowBoxing Allow boxing conversions of arguments.
1540 * @param useVarargs Box trailing arguments into an array for varargs.
1541 */
1542 @SuppressWarnings("fallthrough")
1543 Symbol selectBest(Env<AttrContext> env,
1544 Type site,
1545 List<Type> argtypes,
1546 List<Type> typeargtypes,
1547 Symbol sym,
1548 Symbol bestSoFar,
1549 boolean allowBoxing,
1550 boolean useVarargs) {
1551 if (sym.kind == ERR ||
1552 (site.tsym != sym.owner && !sym.isInheritedIn(site.tsym, types)) ||
1553 !notOverriddenIn(site, sym)) {
1554 return bestSoFar;
1555 } else if (useVarargs && (sym.flags() & VARARGS) == 0) {
1556 return bestSoFar.kind.isResolutionError() ?
1557 new BadVarargsMethod((ResolveError)bestSoFar.baseSymbol()) :
1558 bestSoFar;
1559 }
1560 Assert.check(!sym.kind.isResolutionError());
1561 try {
1562 types.noWarnings.clear();
1563 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes,
1564 allowBoxing, useVarargs, types.noWarnings);
1565 currentResolutionContext.addApplicableCandidate(sym, mt);
1566 } catch (InapplicableMethodException ex) {
1567 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic());
1568 switch (bestSoFar.kind) {
1569 case ABSENT_MTH:
1570 return new InapplicableSymbolError(currentResolutionContext);
1571 case WRONG_MTH:
1572 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1573 default:
1574 return bestSoFar;
1575 }
1576 }
1577 if (!isAccessible(env, site, sym)) {
1578 return (bestSoFar.kind == ABSENT_MTH)
1579 ? new AccessError(env, site, sym)
1580 : bestSoFar;
1581 }
1582 return (bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS)
1583 ? sym
1584 : mostSpecific(argtypes, sym, bestSoFar, env, site, useVarargs);
1585 }
1586
1587 /* Return the most specific of the two methods for a call,
1588 * given that both are accessible and applicable.
1589 * @param m1 A new candidate for most specific.
1590 * @param m2 The previous most specific candidate.
1591 * @param env The current environment.
1592 * @param site The original type from where the selection
1593 * takes place.
1594 * @param allowBoxing Allow boxing conversions of arguments.
1595 * @param useVarargs Box trailing arguments into an array for varargs.
1596 */
1597 Symbol mostSpecific(List<Type> argtypes, Symbol m1,
1598 Symbol m2,
1599 Env<AttrContext> env,
1600 final Type site,
1601 boolean useVarargs) {
1602 switch (m2.kind) {
1603 case MTH:
1604 if (m1 == m2) return m1;
1605 boolean m1SignatureMoreSpecific =
1606 signatureMoreSpecific(argtypes, env, site, m1, m2, useVarargs);
1607 boolean m2SignatureMoreSpecific =
1608 signatureMoreSpecific(argtypes, env, site, m2, m1, useVarargs);
1609 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
1610 Type mt1 = types.memberType(site, m1);
1611 Type mt2 = types.memberType(site, m2);
1612 if (!types.overrideEquivalent(mt1, mt2))
1613 return ambiguityError(m1, m2);
1614
1615 // same signature; select (a) the non-bridge method, or
1616 // (b) the one that overrides the other, or (c) the concrete
1617 // one, or (d) merge both abstract signatures
1618 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
1619 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
1620
1621 if (m1.baseSymbol() == m2.baseSymbol()) {
1622 // this is the same imported symbol which has been cloned twice.
1623 // Return the first one (either will do).
1624 return m1;
1625 }
1626
1627 // if one overrides or hides the other, use it
1628 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
1629 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
1630 // the two owners can never be the same if the target methods are compiled from source,
1631 // but we need to protect against cases where the methods are defined in some classfile
1632 // and make sure we issue an ambiguity error accordingly (by skipping the logic below).
1633 if (m1Owner != m2Owner) {
1634 if (types.asSuper(m1Owner.type, m2Owner) != null &&
1635 ((m1.owner.flags_field & INTERFACE) == 0 ||
1636 (m2.owner.flags_field & INTERFACE) != 0) &&
1637 m1.overrides(m2, m1Owner, types, false))
1638 return m1;
1639 if (types.asSuper(m2Owner.type, m1Owner) != null &&
1640 ((m2.owner.flags_field & INTERFACE) == 0 ||
1641 (m1.owner.flags_field & INTERFACE) != 0) &&
1642 m2.overrides(m1, m2Owner, types, false))
1643 return m2;
1644 }
1645 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
1646 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
1647 if (m1Abstract && !m2Abstract) return m2;
1648 if (m2Abstract && !m1Abstract) return m1;
1649 // both abstract or both concrete
1650 return ambiguityError(m1, m2);
1651 }
1652 if (m1SignatureMoreSpecific) return m1;
1653 if (m2SignatureMoreSpecific) return m2;
1654 return ambiguityError(m1, m2);
1655 case AMBIGUOUS:
1656 //compare m1 to ambiguous methods in m2
1657 AmbiguityError e = (AmbiguityError)m2.baseSymbol();
1658 boolean m1MoreSpecificThanAnyAmbiguous = true;
1659 boolean allAmbiguousMoreSpecificThanM1 = true;
1660 for (Symbol s : e.ambiguousSyms) {
1661 Symbol moreSpecific = mostSpecific(argtypes, m1, s, env, site, useVarargs);
1662 m1MoreSpecificThanAnyAmbiguous &= moreSpecific == m1;
1663 allAmbiguousMoreSpecificThanM1 &= moreSpecific == s;
1664 }
1665 if (m1MoreSpecificThanAnyAmbiguous)
1666 return m1;
1667 //if m1 is more specific than some ambiguous methods, but other ambiguous methods are
1668 //more specific than m1, add it as a new ambiguous method:
1669 if (!allAmbiguousMoreSpecificThanM1)
1670 e.addAmbiguousSymbol(m1);
1671 return e;
1672 default:
1673 throw new AssertionError();
1674 }
1675 }
1676 //where
1677 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean useVarargs) {
1678 noteWarner.clear();
1679 int maxLength = Math.max(
1680 Math.max(m1.type.getParameterTypes().length(), actuals.length()),
1681 m2.type.getParameterTypes().length());
1682 MethodResolutionContext prevResolutionContext = currentResolutionContext;
1683 try {
1684 currentResolutionContext = new MethodResolutionContext();
1685 currentResolutionContext.step = prevResolutionContext.step;
1686 currentResolutionContext.methodCheck =
1687 prevResolutionContext.methodCheck.mostSpecificCheck(actuals);
1688 Type mst = instantiate(env, site, m2, null,
1689 adjustArgs(types.cvarLowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null,
1690 false, useVarargs, noteWarner);
1691 return mst != null &&
1692 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
1693 } finally {
1694 currentResolutionContext = prevResolutionContext;
1695 }
1696 }
1697
1698 List<Type> adjustArgs(List<Type> args, Symbol msym, int length, boolean allowVarargs) {
1699 if ((msym.flags() & VARARGS) != 0 && allowVarargs) {
1700 Type varargsElem = types.elemtype(args.last());
1701 if (varargsElem == null) {
1702 Assert.error("Bad varargs = " + args.last() + " " + msym);
1703 }
1704 List<Type> newArgs = args.reverse().tail.prepend(varargsElem).reverse();
1705 while (newArgs.length() < length) {
1706 newArgs = newArgs.append(newArgs.last());
1707 }
1708 return newArgs;
1709 } else {
1710 return args;
1711 }
1712 }
1713 //where
1714 Symbol ambiguityError(Symbol m1, Symbol m2) {
1715 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
1716 return (m1.flags() & CLASH) == 0 ? m1 : m2;
1717 } else {
1718 return new AmbiguityError(m1, m2);
1719 }
1720 }
1721
1722 Symbol findMethodInScope(Env<AttrContext> env,
1723 Type site,
1724 Name name,
1725 List<Type> argtypes,
1726 List<Type> typeargtypes,
1727 Scope sc,
1728 Symbol bestSoFar,
1729 boolean allowBoxing,
1730 boolean useVarargs,
1731 boolean abstractok) {
1732 for (Symbol s : sc.getSymbolsByName(name, new LookupFilter(abstractok))) {
1733 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s,
1734 bestSoFar, allowBoxing, useVarargs);
1735 }
1736 return bestSoFar;
1737 }
1738 //where
1739 class LookupFilter implements Filter<Symbol> {
1740
1741 boolean abstractOk;
1742
1743 LookupFilter(boolean abstractOk) {
1744 this.abstractOk = abstractOk;
1745 }
1746
1747 public boolean accepts(Symbol s) {
1748 long flags = s.flags();
1749 return s.kind == MTH &&
1750 (flags & SYNTHETIC) == 0 &&
1751 (abstractOk ||
1752 (flags & DEFAULT) != 0 ||
1753 (flags & ABSTRACT) == 0);
1754 }
1755 }
1756
1757 /** Find best qualified method matching given name, type and value
1758 * arguments.
1759 * @param env The current environment.
1760 * @param site The original type from where the selection
1761 * takes place.
1762 * @param name The method's name.
1763 * @param argtypes The method's value arguments.
1764 * @param typeargtypes The method's type arguments
1765 * @param allowBoxing Allow boxing conversions of arguments.
1766 * @param useVarargs Box trailing arguments into an array for varargs.
1767 */
1768 Symbol findMethod(Env<AttrContext> env,
1769 Type site,
1770 Name name,
1771 List<Type> argtypes,
1772 List<Type> typeargtypes,
1773 boolean allowBoxing,
1774 boolean useVarargs) {
1775 Symbol bestSoFar = methodNotFound;
1776 bestSoFar = findMethod(env,
1777 site,
1778 name,
1779 argtypes,
1780 typeargtypes,
1781 site.tsym.type,
1782 bestSoFar,
1783 allowBoxing,
1784 useVarargs);
1785 return bestSoFar;
1786 }
1787 // where
1788 private Symbol findMethod(Env<AttrContext> env,
1789 Type site,
1790 Name name,
1791 List<Type> argtypes,
1792 List<Type> typeargtypes,
1793 Type intype,
1794 Symbol bestSoFar,
1795 boolean allowBoxing,
1796 boolean useVarargs) {
1797 @SuppressWarnings({"unchecked","rawtypes"})
1798 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() };
1799
1800 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK;
1801 for (TypeSymbol s : superclasses(intype)) {
1802 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1803 s.members(), bestSoFar, allowBoxing, useVarargs, true);
1804 if (name == names.init) return bestSoFar;
1805 iphase = (iphase == null) ? null : iphase.update(s, this);
1806 if (iphase != null) {
1807 for (Type itype : types.interfaces(s.type)) {
1808 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]);
1809 }
1810 }
1811 }
1812
1813 Symbol concrete = bestSoFar.kind.isValid() &&
1814 (bestSoFar.flags() & ABSTRACT) == 0 ?
1815 bestSoFar : methodNotFound;
1816
1817 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) {
1818 //keep searching for abstract methods
1819 for (Type itype : itypes[iphase2.ordinal()]) {
1820 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure())
1821 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK &&
1822 (itype.tsym.flags() & DEFAULT) == 0) continue;
1823 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1824 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, true);
1825 if (concrete != bestSoFar &&
1826 concrete.kind.isValid() &&
1827 bestSoFar.kind.isValid() &&
1828 types.isSubSignature(concrete.type, bestSoFar.type)) {
1829 //this is an hack - as javac does not do full membership checks
1830 //most specific ends up comparing abstract methods that might have
1831 //been implemented by some concrete method in a subclass and,
1832 //because of raw override, it is possible for an abstract method
1833 //to be more specific than the concrete method - so we need
1834 //to explicitly call that out (see CR 6178365)
1835 bestSoFar = concrete;
1836 }
1837 }
1838 }
1839 return bestSoFar;
1840 }
1841
1842 enum InterfaceLookupPhase {
1843 ABSTRACT_OK() {
1844 @Override
1845 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1846 //We should not look for abstract methods if receiver is a concrete class
1847 //(as concrete classes are expected to implement all abstracts coming
1848 //from superinterfaces)
1849 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) {
1850 return this;
1851 } else {
1852 return DEFAULT_OK;
1853 }
1854 }
1855 },
1856 DEFAULT_OK() {
1857 @Override
1858 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1859 return this;
1860 }
1861 };
1862
1863 abstract InterfaceLookupPhase update(Symbol s, Resolve rs);
1864 }
1865
1866 /**
1867 * Return an Iterable object to scan the superclasses of a given type.
1868 * It's crucial that the scan is done lazily, as we don't want to accidentally
1869 * access more supertypes than strictly needed (as this could trigger completion
1870 * errors if some of the not-needed supertypes are missing/ill-formed).
1871 */
1872 Iterable<TypeSymbol> superclasses(final Type intype) {
1873 return () -> new Iterator<TypeSymbol>() {
1874
1875 List<TypeSymbol> seen = List.nil();
1876 TypeSymbol currentSym = symbolFor(intype);
1877 TypeSymbol prevSym = null;
1878
1879 public boolean hasNext() {
1880 if (currentSym == syms.noSymbol) {
1881 currentSym = symbolFor(types.supertype(prevSym.type));
1882 }
1883 return currentSym != null;
1884 }
1885
1886 public TypeSymbol next() {
1887 prevSym = currentSym;
1888 currentSym = syms.noSymbol;
1889 Assert.check(prevSym != null || prevSym != syms.noSymbol);
1890 return prevSym;
1891 }
1892
1893 public void remove() {
1894 throw new UnsupportedOperationException();
1895 }
1896
1897 TypeSymbol symbolFor(Type t) {
1898 if (!t.hasTag(CLASS) &&
1899 !t.hasTag(TYPEVAR)) {
1900 return null;
1901 }
1902 t = types.skipTypeVars(t, false);
1903 if (seen.contains(t.tsym)) {
1904 //degenerate case in which we have a circular
1905 //class hierarchy - because of ill-formed classfiles
1906 return null;
1907 }
1908 seen = seen.prepend(t.tsym);
1909 return t.tsym;
1910 }
1911 };
1912 }
1913
1914 /** Find unqualified method matching given name, type and value arguments.
1915 * @param env The current environment.
1916 * @param name The method's name.
1917 * @param argtypes The method's value arguments.
1918 * @param typeargtypes The method's type arguments.
1919 * @param allowBoxing Allow boxing conversions of arguments.
1920 * @param useVarargs Box trailing arguments into an array for varargs.
1921 */
1922 Symbol findFun(Env<AttrContext> env, Name name,
1923 List<Type> argtypes, List<Type> typeargtypes,
1924 boolean allowBoxing, boolean useVarargs) {
1925 Symbol bestSoFar = methodNotFound;
1926 Env<AttrContext> env1 = env;
1927 boolean staticOnly = false;
1928 while (env1.outer != null) {
1929 if (isStatic(env1)) staticOnly = true;
1930 Assert.check(env1.info.preferredTreeForDiagnostics == null);
1931 env1.info.preferredTreeForDiagnostics = env.tree;
1932 try {
1933 Symbol sym = findMethod(
1934 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
1935 allowBoxing, useVarargs);
1936 if (sym.exists()) {
1937 if (staticOnly &&
1938 sym.kind == MTH &&
1939 sym.owner.kind == TYP &&
1940 (sym.flags() & STATIC) == 0) return new StaticError(sym);
1941 else return sym;
1942 } else {
1943 bestSoFar = bestOf(bestSoFar, sym);
1944 }
1945 } finally {
1946 env1.info.preferredTreeForDiagnostics = null;
1947 }
1948 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1949 env1 = env1.outer;
1950 }
1951
1952 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
1953 typeargtypes, allowBoxing, useVarargs);
1954 if (sym.exists())
1955 return sym;
1956
1957 for (Symbol currentSym : env.toplevel.namedImportScope.getSymbolsByName(name)) {
1958 Symbol origin = env.toplevel.namedImportScope.getOrigin(currentSym).owner;
1959 if (currentSym.kind == MTH) {
1960 if (currentSym.owner.type != origin.type)
1961 currentSym = currentSym.clone(origin);
1962 if (!isAccessible(env, origin.type, currentSym))
1963 currentSym = new AccessError(env, origin.type, currentSym);
1964 bestSoFar = selectBest(env, origin.type,
1965 argtypes, typeargtypes,
1966 currentSym, bestSoFar,
1967 allowBoxing, useVarargs);
1968 }
1969 }
1970 if (bestSoFar.exists())
1971 return bestSoFar;
1972
1973 for (Symbol currentSym : env.toplevel.starImportScope.getSymbolsByName(name)) {
1974 Symbol origin = env.toplevel.starImportScope.getOrigin(currentSym).owner;
1975 if (currentSym.kind == MTH) {
1976 if (currentSym.owner.type != origin.type)
1977 currentSym = currentSym.clone(origin);
1978 if (!isAccessible(env, origin.type, currentSym))
1979 currentSym = new AccessError(env, origin.type, currentSym);
1980 bestSoFar = selectBest(env, origin.type,
1981 argtypes, typeargtypes,
1982 currentSym, bestSoFar,
1983 allowBoxing, useVarargs);
1984 }
1985 }
1986 return bestSoFar;
1987 }
1988
1989 /** Load toplevel or member class with given fully qualified name and
1990 * verify that it is accessible.
1991 * @param env The current environment.
1992 * @param name The fully qualified name of the class to be loaded.
1993 */
1994 Symbol loadClass(Env<AttrContext> env, Name name, RecoveryLoadClass recoveryLoadClass) {
1995 try {
1996 ClassSymbol c = finder.loadClass(env.toplevel.modle, name);
1997 return isAccessible(env, c) ? c : new AccessError(env, null, c);
1998 } catch (ClassFinder.BadClassFile err) {
1999 return new BadClassFileError(err);
2000 } catch (CompletionFailure ex) {
2001 Symbol candidate = recoveryLoadClass.loadClass(env, name);
2002
2003 if (candidate != null) {
2004 return candidate;
2005 }
2006
2007 return typeNotFound;
2008 }
2009 }
2010
2011 public interface RecoveryLoadClass {
2012 Symbol loadClass(Env<AttrContext> env, Name name);
2013 }
2014
2015 private final RecoveryLoadClass noRecovery = (env, name) -> null;
2016
2017 private final RecoveryLoadClass doRecoveryLoadClass = new RecoveryLoadClass() {
2018 @Override public Symbol loadClass(Env<AttrContext> env, Name name) {
2019 List<Name> candidates = Convert.classCandidates(name);
2020 return lookupInvisibleSymbol(env, name,
2021 n -> () -> createCompoundIterator(candidates,
2022 c -> syms.getClassesForName(c)
2023 .iterator()),
2024 (ms, n) -> {
2025 for (Name candidate : candidates) {
2026 try {
2027 return finder.loadClass(ms, candidate);
2028 } catch (CompletionFailure cf) {
2029 //ignore
2030 }
2031 }
2032 return null;
2033 }, sym -> sym.kind == Kind.TYP, typeNotFound);
2034 }
2035 };
2036
2037 private final RecoveryLoadClass namedImportScopeRecovery = (env, name) -> {
2038 Scope importScope = env.toplevel.namedImportScope;
2039 Symbol existing = importScope.findFirst(Convert.shortName(name),
2040 sym -> sym.kind == TYP && sym.flatName() == name);
2041
2042 if (existing != null) {
2043 return new InvisibleSymbolError(env, true, existing);
2044 }
2045 return null;
2046 };
2047
2048 private final RecoveryLoadClass starImportScopeRecovery = (env, name) -> {
2049 Scope importScope = env.toplevel.starImportScope;
2050 Symbol existing = importScope.findFirst(Convert.shortName(name),
2051 sym -> sym.kind == TYP && sym.flatName() == name);
2052
2053 if (existing != null) {
2054 try {
2055 existing = finder.loadClass(existing.packge().modle, name);
2056
2057 return new InvisibleSymbolError(env, true, existing);
2058 } catch (CompletionFailure cf) {
2059 //ignore
2060 }
2061 }
2062
2063 return null;
2064 };
2065
2066 Symbol lookupPackage(Env<AttrContext> env, Name name) {
2067 PackageSymbol pack = syms.lookupPackage(env.toplevel.modle, name);
2068
2069 if (allowModules && isImportOnDemand(env, name)) {
2070 if (pack.members().isEmpty()) {
2071 return lookupInvisibleSymbol(env, name, syms::getPackagesForName, syms::enterPackage, sym -> {
2072 sym.complete();
2073 return !sym.members().isEmpty();
2074 }, pack);
2075 }
2076 }
2077
2078 return pack;
2079 }
2080
2081 private boolean isImportOnDemand(Env<AttrContext> env, Name name) {
2082 if (!env.tree.hasTag(IMPORT))
2083 return false;
2084
2085 JCTree qualid = ((JCImport) env.tree).qualid;
2086
2087 if (!qualid.hasTag(SELECT))
2088 return false;
2089
2090 if (TreeInfo.name(qualid) != names.asterisk)
2091 return false;
2092
2093 return TreeInfo.fullName(((JCFieldAccess) qualid).selected) == name;
2094 }
2095
2096 private <S extends Symbol> Symbol lookupInvisibleSymbol(Env<AttrContext> env,
2097 Name name,
2098 Function<Name, Iterable<S>> get,
2099 BiFunction<ModuleSymbol, Name, S> load,
2100 Predicate<S> validate,
2101 Symbol defaultResult) {
2102 //even if a class/package cannot be found in the current module and among packages in modules
2103 //it depends on that are exported for any or this module, the class/package may exist internally
2104 //in some of these modules, or may exist in a module on which this module does not depend.
2105 //Provide better diagnostic in such cases by looking for the class in any module:
2106 Iterable<? extends S> candidates = get.apply(name);
2107
2108 for (S sym : candidates) {
2109 if (validate.test(sym))
2110 return createInvisibleSymbolError(env, sym);
2111 }
2112
2113 Set<ModuleSymbol> recoverableModules = new HashSet<>(syms.getAllModules());
2114
2115 recoverableModules.add(syms.unnamedModule);
2116 recoverableModules.remove(env.toplevel.modle);
2117
2118 for (ModuleSymbol ms : recoverableModules) {
2119 //avoid overly eager completing classes from source-based modules, as those
2120 //may not be completable with the current compiler settings:
2121 if (ms.sourceLocation == null) {
2122 if (ms.classLocation == null) {
2123 ms = moduleFinder.findModule(ms);
2124 }
2125
2126 if (ms.kind != ERR) {
2127 S sym = load.apply(ms, name);
2128
2129 if (sym != null && validate.test(sym)) {
2130 return createInvisibleSymbolError(env, sym);
2131 }
2132 }
2133 }
2134 }
2135
2136 return defaultResult;
2137 }
2138
2139 private Symbol createInvisibleSymbolError(Env<AttrContext> env, Symbol sym) {
2140 if (symbolPackageVisible(env, sym)) {
2141 return new AccessError(env, null, sym);
2142 } else {
2143 return new InvisibleSymbolError(env, false, sym);
2144 }
2145 }
2146
2147 private boolean symbolPackageVisible(Env<AttrContext> env, Symbol sym) {
2148 ModuleSymbol envMod = env.toplevel.modle;
2149 PackageSymbol symPack = sym.packge();
2150 return envMod == symPack.modle ||
2151 envMod.visiblePackages.containsKey(symPack.fullname);
2152 }
2153
2154 /**
2155 * Find a type declared in a scope (not inherited). Return null
2156 * if none is found.
2157 * @param env The current environment.
2158 * @param site The original type from where the selection takes
2159 * place.
2160 * @param name The type's name.
2161 * @param c The class to search for the member type. This is
2162 * always a superclass or implemented interface of
2163 * site's class.
2164 */
2165 Symbol findImmediateMemberType(Env<AttrContext> env,
2166 Type site,
2167 Name name,
2168 TypeSymbol c) {
2169 for (Symbol sym : c.members().getSymbolsByName(name)) {
2170 if (sym.kind == TYP) {
2171 return isAccessible(env, site, sym)
2172 ? sym
2173 : new AccessError(env, site, sym);
2174 }
2175 }
2176 return typeNotFound;
2177 }
2178
2179 /** Find a member type inherited from a superclass or interface.
2180 * @param env The current environment.
2181 * @param site The original type from where the selection takes
2182 * place.
2183 * @param name The type's name.
2184 * @param c The class to search for the member type. This is
2185 * always a superclass or implemented interface of
2186 * site's class.
2187 */
2188 Symbol findInheritedMemberType(Env<AttrContext> env,
2189 Type site,
2190 Name name,
2191 TypeSymbol c) {
2192 Symbol bestSoFar = typeNotFound;
2193 Symbol sym;
2194 Type st = types.supertype(c.type);
2195 if (st != null && st.hasTag(CLASS)) {
2196 sym = findMemberType(env, site, name, st.tsym);
2197 bestSoFar = bestOf(bestSoFar, sym);
2198 }
2199 for (List<Type> l = types.interfaces(c.type);
2200 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
2201 l = l.tail) {
2202 sym = findMemberType(env, site, name, l.head.tsym);
2203 if (!bestSoFar.kind.isResolutionError() &&
2204 !sym.kind.isResolutionError() &&
2205 sym.owner != bestSoFar.owner)
2206 bestSoFar = new AmbiguityError(bestSoFar, sym);
2207 else
2208 bestSoFar = bestOf(bestSoFar, sym);
2209 }
2210 return bestSoFar;
2211 }
2212
2213 /** Find qualified member type.
2214 * @param env The current environment.
2215 * @param site The original type from where the selection takes
2216 * place.
2217 * @param name The type's name.
2218 * @param c The class to search for the member type. This is
2219 * always a superclass or implemented interface of
2220 * site's class.
2221 */
2222 Symbol findMemberType(Env<AttrContext> env,
2223 Type site,
2224 Name name,
2225 TypeSymbol c) {
2226 Symbol sym = findImmediateMemberType(env, site, name, c);
2227
2228 if (sym != typeNotFound)
2229 return sym;
2230
2231 return findInheritedMemberType(env, site, name, c);
2232
2233 }
2234
2235 /** Find a global type in given scope and load corresponding class.
2236 * @param env The current environment.
2237 * @param scope The scope in which to look for the type.
2238 * @param name The type's name.
2239 */
2240 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name, RecoveryLoadClass recoveryLoadClass) {
2241 Symbol bestSoFar = typeNotFound;
2242 for (Symbol s : scope.getSymbolsByName(name)) {
2243 Symbol sym = loadClass(env, s.flatName(), recoveryLoadClass);
2244 if (bestSoFar.kind == TYP && sym.kind == TYP &&
2245 bestSoFar != sym)
2246 return new AmbiguityError(bestSoFar, sym);
2247 else
2248 bestSoFar = bestOf(bestSoFar, sym);
2249 }
2250 return bestSoFar;
2251 }
2252
2253 Symbol findTypeVar(Env<AttrContext> env, Name name, boolean staticOnly) {
2254 for (Symbol sym : env.info.scope.getSymbolsByName(name)) {
2255 if (sym.kind == TYP) {
2256 if (staticOnly &&
2257 sym.type.hasTag(TYPEVAR) &&
2258 sym.owner.kind == TYP)
2259 return new StaticError(sym);
2260 return sym;
2261 }
2262 }
2263 return typeNotFound;
2264 }
2265
2266 /** Find an unqualified type symbol.
2267 * @param env The current environment.
2268 * @param name The type's name.
2269 */
2270 Symbol findType(Env<AttrContext> env, Name name) {
2271 if (name == names.empty)
2272 return typeNotFound; // do not allow inadvertent "lookup" of anonymous types
2273 Symbol bestSoFar = typeNotFound;
2274 Symbol sym;
2275 boolean staticOnly = false;
2276 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
2277 if (isStatic(env1)) staticOnly = true;
2278 // First, look for a type variable and the first member type
2279 final Symbol tyvar = findTypeVar(env1, name, staticOnly);
2280 sym = findImmediateMemberType(env1, env1.enclClass.sym.type,
2281 name, env1.enclClass.sym);
2282
2283 // Return the type variable if we have it, and have no
2284 // immediate member, OR the type variable is for a method.
2285 if (tyvar != typeNotFound) {
2286 if (env.baseClause || sym == typeNotFound ||
2287 (tyvar.kind == TYP && tyvar.exists() &&
2288 tyvar.owner.kind == MTH)) {
2289 return tyvar;
2290 }
2291 }
2292
2293 // If the environment is a class def, finish up,
2294 // otherwise, do the entire findMemberType
2295 if (sym == typeNotFound)
2296 sym = findInheritedMemberType(env1, env1.enclClass.sym.type,
2297 name, env1.enclClass.sym);
2298
2299 if (staticOnly && sym.kind == TYP &&
2300 sym.type.hasTag(CLASS) &&
2301 sym.type.getEnclosingType().hasTag(CLASS) &&
2302 env1.enclClass.sym.type.isParameterized() &&
2303 sym.type.getEnclosingType().isParameterized())
2304 return new StaticError(sym);
2305 else if (sym.exists()) return sym;
2306 else bestSoFar = bestOf(bestSoFar, sym);
2307
2308 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
2309 if ((encl.sym.flags() & STATIC) != 0)
2310 staticOnly = true;
2311 }
2312
2313 if (!env.tree.hasTag(IMPORT)) {
2314 sym = findGlobalType(env, env.toplevel.namedImportScope, name, namedImportScopeRecovery);
2315 if (sym.exists()) return sym;
2316 else bestSoFar = bestOf(bestSoFar, sym);
2317
2318 sym = findGlobalType(env, env.toplevel.toplevelScope, name, noRecovery);
2319 if (sym.exists()) return sym;
2320 else bestSoFar = bestOf(bestSoFar, sym);
2321
2322 sym = findGlobalType(env, env.toplevel.packge.members(), name, noRecovery);
2323 if (sym.exists()) return sym;
2324 else bestSoFar = bestOf(bestSoFar, sym);
2325
2326 sym = findGlobalType(env, env.toplevel.starImportScope, name, starImportScopeRecovery);
2327 if (sym.exists()) return sym;
2328 else bestSoFar = bestOf(bestSoFar, sym);
2329 }
2330
2331 return bestSoFar;
2332 }
2333
2334 /** Find an unqualified identifier which matches a specified kind set.
2335 * @param env The current environment.
2336 * @param name The identifier's name.
2337 * @param kind Indicates the possible symbol kinds
2338 * (a subset of VAL, TYP, PCK).
2339 */
2340 Symbol findIdent(Env<AttrContext> env, Name name, KindSelector kind) {
2341 return checkVarType(findIdentInternal(env, name, kind), name);
2342 }
2343
2344 Symbol findIdentInternal(Env<AttrContext> env, Name name, KindSelector kind) {
2345 Symbol bestSoFar = typeNotFound;
2346 Symbol sym;
2347
2348 if (kind.contains(KindSelector.VAL)) {
2349 sym = findVar(env, name);
2350 if (sym.exists()) return sym;
2351 else bestSoFar = bestOf(bestSoFar, sym);
2352 }
2353
2354 if (kind.contains(KindSelector.TYP)) {
2355 sym = findType(env, name);
2356
2357 if (sym.exists()) return sym;
2358 else bestSoFar = bestOf(bestSoFar, sym);
2359 }
2360
2361 if (kind.contains(KindSelector.PCK))
2362 return lookupPackage(env, name);
2363 else return bestSoFar;
2364 }
2365
2366 /** Find an identifier in a package which matches a specified kind set.
2367 * @param env The current environment.
2368 * @param name The identifier's name.
2369 * @param kind Indicates the possible symbol kinds
2370 * (a nonempty subset of TYP, PCK).
2371 */
2372 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
2373 Name name, KindSelector kind) {
2374 return checkVarType(findIdentInPackageInternal(env, pck, name, kind), name);
2375 }
2376
2377 Symbol findIdentInPackageInternal(Env<AttrContext> env, TypeSymbol pck,
2378 Name name, KindSelector kind) {
2379 Name fullname = TypeSymbol.formFullName(name, pck);
2380 Symbol bestSoFar = typeNotFound;
2381 if (kind.contains(KindSelector.TYP)) {
2382 RecoveryLoadClass recoveryLoadClass =
2383 allowModules && !kind.contains(KindSelector.PCK) &&
2384 !pck.exists() && !env.info.isSpeculative ?
2385 doRecoveryLoadClass : noRecovery;
2386 Symbol sym = loadClass(env, fullname, recoveryLoadClass);
2387 if (sym.exists()) {
2388 // don't allow programs to use flatnames
2389 if (name == sym.name) return sym;
2390 }
2391 else bestSoFar = bestOf(bestSoFar, sym);
2392 }
2393 if (kind.contains(KindSelector.PCK)) {
2394 return lookupPackage(env, fullname);
2395 }
2396 return bestSoFar;
2397 }
2398
2399 /** Find an identifier among the members of a given type `site'.
2400 * @param env The current environment.
2401 * @param site The type containing the symbol to be found.
2402 * @param name The identifier's name.
2403 * @param kind Indicates the possible symbol kinds
2404 * (a subset of VAL, TYP).
2405 */
2406 Symbol findIdentInType(Env<AttrContext> env, Type site,
2407 Name name, KindSelector kind) {
2408 return checkVarType(findIdentInTypeInternal(env, site, name, kind), name);
2409 }
2410
2411 Symbol findIdentInTypeInternal(Env<AttrContext> env, Type site,
2412 Name name, KindSelector kind) {
2413 Symbol bestSoFar = typeNotFound;
2414 Symbol sym;
2415 if (kind.contains(KindSelector.VAL)) {
2416 sym = findField(env, site, name, site.tsym);
2417 if (sym.exists()) return sym;
2418 else bestSoFar = bestOf(bestSoFar, sym);
2419 }
2420
2421 if (kind.contains(KindSelector.TYP)) {
2422 sym = findMemberType(env, site, name, site.tsym);
2423 if (sym.exists()) return sym;
2424 else bestSoFar = bestOf(bestSoFar, sym);
2425 }
2426 return bestSoFar;
2427 }
2428
2429 private Symbol checkVarType(Symbol bestSoFar, Name name) {
2430 if (allowLocalVariableTypeInference && name.equals(names.var) &&
2431 (bestSoFar.kind == TYP || bestSoFar.kind == ABSENT_TYP)) {
2432 bestSoFar = new BadVarTypeError();
2433 }
2434 return bestSoFar;
2435 }
2436
2437 /* ***************************************************************************
2438 * Access checking
2439 * The following methods convert ResolveErrors to ErrorSymbols, issuing
2440 * an error message in the process
2441 ****************************************************************************/
2442
2443 /** If `sym' is a bad symbol: report error and return errSymbol
2444 * else pass through unchanged,
2445 * additional arguments duplicate what has been used in trying to find the
2446 * symbol {@literal (--> flyweight pattern)}. This improves performance since we
2447 * expect misses to happen frequently.
2448 *
2449 * @param sym The symbol that was found, or a ResolveError.
2450 * @param pos The position to use for error reporting.
2451 * @param location The symbol the served as a context for this lookup
2452 * @param site The original type from where the selection took place.
2453 * @param name The symbol's name.
2454 * @param qualified Did we get here through a qualified expression resolution?
2455 * @param argtypes The invocation's value arguments,
2456 * if we looked for a method.
2457 * @param typeargtypes The invocation's type arguments,
2458 * if we looked for a method.
2459 * @param logResolveHelper helper class used to log resolve errors
2460 */
2461 Symbol accessInternal(Symbol sym,
2462 DiagnosticPosition pos,
2463 Symbol location,
2464 Type site,
2465 Name name,
2466 boolean qualified,
2467 List<Type> argtypes,
2468 List<Type> typeargtypes,
2469 LogResolveHelper logResolveHelper) {
2470 if (sym.kind.isResolutionError()) {
2471 ResolveError errSym = (ResolveError)sym.baseSymbol();
2472 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
2473 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes);
2474 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) {
2475 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
2476 }
2477 }
2478 return sym;
2479 }
2480
2481 /**
2482 * Variant of the generalized access routine, to be used for generating method
2483 * resolution diagnostics
2484 */
2485 Symbol accessMethod(Symbol sym,
2486 DiagnosticPosition pos,
2487 Symbol location,
2488 Type site,
2489 Name name,
2490 boolean qualified,
2491 List<Type> argtypes,
2492 List<Type> typeargtypes) {
2493 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper);
2494 }
2495
2496 /** Same as original accessMethod(), but without location.
2497 */
2498 Symbol accessMethod(Symbol sym,
2499 DiagnosticPosition pos,
2500 Type site,
2501 Name name,
2502 boolean qualified,
2503 List<Type> argtypes,
2504 List<Type> typeargtypes) {
2505 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
2506 }
2507
2508 /**
2509 * Variant of the generalized access routine, to be used for generating variable,
2510 * type resolution diagnostics
2511 */
2512 Symbol accessBase(Symbol sym,
2513 DiagnosticPosition pos,
2514 Symbol location,
2515 Type site,
2516 Name name,
2517 boolean qualified) {
2518 return accessInternal(sym, pos, location, site, name, qualified, List.nil(), null, basicLogResolveHelper);
2519 }
2520
2521 /** Same as original accessBase(), but without location.
2522 */
2523 Symbol accessBase(Symbol sym,
2524 DiagnosticPosition pos,
2525 Type site,
2526 Name name,
2527 boolean qualified) {
2528 return accessBase(sym, pos, site.tsym, site, name, qualified);
2529 }
2530
2531 interface LogResolveHelper {
2532 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes);
2533 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes);
2534 }
2535
2536 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() {
2537 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2538 return !site.isErroneous();
2539 }
2540 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2541 return argtypes;
2542 }
2543 };
2544
2545 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() {
2546 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2547 return !site.isErroneous() &&
2548 !Type.isErroneous(argtypes) &&
2549 (typeargtypes == null || !Type.isErroneous(typeargtypes));
2550 }
2551 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2552 return argtypes.map(new ResolveDeferredRecoveryMap(AttrMode.SPECULATIVE, accessedSym, currentResolutionContext.step));
2553 }
2554 };
2555
2556 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap {
2557
2558 public ResolveDeferredRecoveryMap(AttrMode mode, Symbol msym, MethodResolutionPhase step) {
2559 deferredAttr.super(mode, msym, step);
2560 }
2561
2562 @Override
2563 protected Type typeOf(DeferredType dt, Type pt) {
2564 Type res = super.typeOf(dt, pt);
2565 if (!res.isErroneous()) {
2566 switch (TreeInfo.skipParens(dt.tree).getTag()) {
2567 case LAMBDA:
2568 case REFERENCE:
2569 return dt;
2570 case CONDEXPR:
2571 return res == Type.recoveryType ?
2572 dt : res;
2573 }
2574 }
2575 return res;
2576 }
2577 }
2578
2579 /** Check that sym is not an abstract method.
2580 */
2581 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
2582 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0)
2583 log.error(pos,
2584 Errors.AbstractCantBeAccessedDirectly(kindName(sym),sym, sym.location()));
2585 }
2586
2587 /* ***************************************************************************
2588 * Name resolution
2589 * Naming conventions are as for symbol lookup
2590 * Unlike the find... methods these methods will report access errors
2591 ****************************************************************************/
2592
2593 /** Resolve an unqualified (non-method) identifier.
2594 * @param pos The position to use for error reporting.
2595 * @param env The environment current at the identifier use.
2596 * @param name The identifier's name.
2597 * @param kind The set of admissible symbol kinds for the identifier.
2598 */
2599 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
2600 Name name, KindSelector kind) {
2601 return accessBase(
2602 findIdent(env, name, kind),
2603 pos, env.enclClass.sym.type, name, false);
2604 }
2605
2606 /** Resolve an unqualified method identifier.
2607 * @param pos The position to use for error reporting.
2608 * @param env The environment current at the method invocation.
2609 * @param name The identifier's name.
2610 * @param argtypes The types of the invocation's value arguments.
2611 * @param typeargtypes The types of the invocation's type arguments.
2612 */
2613 Symbol resolveMethod(DiagnosticPosition pos,
2614 Env<AttrContext> env,
2615 Name name,
2616 List<Type> argtypes,
2617 List<Type> typeargtypes) {
2618 return lookupMethod(env, pos, env.enclClass.sym, resolveMethodCheck,
2619 new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) {
2620 @Override
2621 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2622 return findFun(env, name, argtypes, typeargtypes,
2623 phase.isBoxingRequired(),
2624 phase.isVarargsRequired());
2625 }});
2626 }
2627
2628 /** Resolve a qualified method identifier
2629 * @param pos The position to use for error reporting.
2630 * @param env The environment current at the method invocation.
2631 * @param site The type of the qualifying expression, in which
2632 * identifier is searched.
2633 * @param name The identifier's name.
2634 * @param argtypes The types of the invocation's value arguments.
2635 * @param typeargtypes The types of the invocation's type arguments.
2636 */
2637 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2638 Type site, Name name, List<Type> argtypes,
2639 List<Type> typeargtypes) {
2640 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
2641 }
2642 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2643 Symbol location, Type site, Name name, List<Type> argtypes,
2644 List<Type> typeargtypes) {
2645 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
2646 }
2647 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
2648 DiagnosticPosition pos, Env<AttrContext> env,
2649 Symbol location, Type site, Name name, List<Type> argtypes,
2650 List<Type> typeargtypes) {
2651 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) {
2652 @Override
2653 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2654 return findMethod(env, site, name, argtypes, typeargtypes,
2655 phase.isBoxingRequired(),
2656 phase.isVarargsRequired());
2657 }
2658 @Override
2659 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2660 if (sym.kind.isResolutionError()) {
2661 sym = super.access(env, pos, location, sym);
2662 } else if (allowMethodHandles) {
2663 MethodSymbol msym = (MethodSymbol)sym;
2664 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) {
2665 env.info.pendingResolutionPhase = BASIC;
2666 return findPolymorphicSignatureInstance(env, sym, argtypes);
2667 }
2668 }
2669 return sym;
2670 }
2671 });
2672 }
2673
2674 /** Find or create an implicit method of exactly the given type (after erasure).
2675 * Searches in a side table, not the main scope of the site.
2676 * This emulates the lookup process required by JSR 292 in JVM.
2677 * @param env Attribution environment
2678 * @param spMethod signature polymorphic method - i.e. MH.invokeExact
2679 * @param argtypes The required argument types
2680 */
2681 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env,
2682 final Symbol spMethod,
2683 List<Type> argtypes) {
2684 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
2685 (MethodSymbol)spMethod, currentResolutionContext, argtypes);
2686 return findPolymorphicSignatureInstance(spMethod, mtype);
2687 }
2688
2689 Symbol findPolymorphicSignatureInstance(final Symbol spMethod,
2690 Type mtype) {
2691 for (Symbol sym : polymorphicSignatureScope.getSymbolsByName(spMethod.name)) {
2692 // Check that there is already a method symbol for the method
2693 // type and owner
2694 if (types.isSameType(mtype, sym.type) &&
2695 spMethod.owner == sym.owner) {
2696 return sym;
2697 }
2698 }
2699
2700 // Create the desired method
2701 // Retain static modifier is to support invocations to
2702 // MethodHandle.linkTo* methods
2703 long flags = ABSTRACT | HYPOTHETICAL |
2704 spMethod.flags() & (Flags.AccessFlags | Flags.STATIC);
2705 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) {
2706 @Override
2707 public Symbol baseSymbol() {
2708 return spMethod;
2709 }
2710 };
2711 if (!mtype.isErroneous()) { // Cache only if kosher.
2712 polymorphicSignatureScope.enter(msym);
2713 }
2714 return msym;
2715 }
2716
2717 /** Resolve a qualified method identifier, throw a fatal error if not
2718 * found.
2719 * @param pos The position to use for error reporting.
2720 * @param env The environment current at the method invocation.
2721 * @param site The type of the qualifying expression, in which
2722 * identifier is searched.
2723 * @param name The identifier's name.
2724 * @param argtypes The types of the invocation's value arguments.
2725 * @param typeargtypes The types of the invocation's type arguments.
2726 */
2727 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
2728 Type site, Name name,
2729 List<Type> argtypes,
2730 List<Type> typeargtypes) {
2731 MethodResolutionContext resolveContext = new MethodResolutionContext();
2732 resolveContext.internalResolution = true;
2733 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
2734 site, name, argtypes, typeargtypes);
2735 if (sym.kind == MTH) return (MethodSymbol)sym;
2736 else throw new FatalError(
2737 diags.fragment(Fragments.FatalErrCantLocateMeth(name)));
2738 }
2739
2740 /** Resolve constructor.
2741 * @param pos The position to use for error reporting.
2742 * @param env The environment current at the constructor invocation.
2743 * @param site The type of class for which a constructor is searched.
2744 * @param argtypes The types of the constructor invocation's value
2745 * arguments.
2746 * @param typeargtypes The types of the constructor invocation's type
2747 * arguments.
2748 */
2749 Symbol resolveConstructor(DiagnosticPosition pos,
2750 Env<AttrContext> env,
2751 Type site,
2752 List<Type> argtypes,
2753 List<Type> typeargtypes) {
2754 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
2755 }
2756
2757 private Symbol resolveConstructor(MethodResolutionContext resolveContext,
2758 final DiagnosticPosition pos,
2759 Env<AttrContext> env,
2760 Type site,
2761 List<Type> argtypes,
2762 List<Type> typeargtypes) {
2763 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2764 @Override
2765 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2766 return findConstructor(pos, env, site, argtypes, typeargtypes,
2767 phase.isBoxingRequired(),
2768 phase.isVarargsRequired());
2769 }
2770 });
2771 }
2772
2773 /** Resolve a constructor, throw a fatal error if not found.
2774 * @param pos The position to use for error reporting.
2775 * @param env The environment current at the method invocation.
2776 * @param site The type to be constructed.
2777 * @param argtypes The types of the invocation's value arguments.
2778 * @param typeargtypes The types of the invocation's type arguments.
2779 */
2780 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2781 Type site,
2782 List<Type> argtypes,
2783 List<Type> typeargtypes) {
2784 MethodResolutionContext resolveContext = new MethodResolutionContext();
2785 resolveContext.internalResolution = true;
2786 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
2787 if (sym.kind == MTH) return (MethodSymbol)sym;
2788 else throw new FatalError(
2789 diags.fragment(Fragments.FatalErrCantLocateCtor(site)));
2790 }
2791
2792 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2793 Type site, List<Type> argtypes,
2794 List<Type> typeargtypes,
2795 boolean allowBoxing,
2796 boolean useVarargs) {
2797 Symbol sym = findMethod(env, site,
2798 names.init, argtypes,
2799 typeargtypes, allowBoxing,
2800 useVarargs);
2801 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2802 return sym;
2803 }
2804
2805 /** Resolve constructor using diamond inference.
2806 * @param pos The position to use for error reporting.
2807 * @param env The environment current at the constructor invocation.
2808 * @param site The type of class for which a constructor is searched.
2809 * The scope of this class has been touched in attribution.
2810 * @param argtypes The types of the constructor invocation's value
2811 * arguments.
2812 * @param typeargtypes The types of the constructor invocation's type
2813 * arguments.
2814 */
2815 Symbol resolveDiamond(DiagnosticPosition pos,
2816 Env<AttrContext> env,
2817 Type site,
2818 List<Type> argtypes,
2819 List<Type> typeargtypes) {
2820 return lookupMethod(env, pos, site.tsym, resolveMethodCheck,
2821 new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2822 @Override
2823 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2824 return findDiamond(env, site, argtypes, typeargtypes,
2825 phase.isBoxingRequired(),
2826 phase.isVarargsRequired());
2827 }
2828 @Override
2829 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2830 if (sym.kind.isResolutionError()) {
2831 if (sym.kind != WRONG_MTH &&
2832 sym.kind != WRONG_MTHS) {
2833 sym = super.access(env, pos, location, sym);
2834 } else {
2835 final JCDiagnostic details = sym.kind == WRONG_MTH ?
2836 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd :
2837 null;
2838 sym = new DiamondError(sym, currentResolutionContext);
2839 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes);
2840 env.info.pendingResolutionPhase = currentResolutionContext.step;
2841 }
2842 }
2843 return sym;
2844 }});
2845 }
2846
2847 /** This method scans all the constructor symbol in a given class scope -
2848 * assuming that the original scope contains a constructor of the kind:
2849 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
2850 * a method check is executed against the modified constructor type:
2851 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond
2852 * inference. The inferred return type of the synthetic constructor IS
2853 * the inferred type for the diamond operator.
2854 */
2855 private Symbol findDiamond(Env<AttrContext> env,
2856 Type site,
2857 List<Type> argtypes,
2858 List<Type> typeargtypes,
2859 boolean allowBoxing,
2860 boolean useVarargs) {
2861 Symbol bestSoFar = methodNotFound;
2862 TypeSymbol tsym = site.tsym.isInterface() ? syms.objectType.tsym : site.tsym;
2863 for (final Symbol sym : tsym.members().getSymbolsByName(names.init)) {
2864 //- System.out.println(" e " + e.sym);
2865 if (sym.kind == MTH &&
2866 (sym.flags_field & SYNTHETIC) == 0) {
2867 List<Type> oldParams = sym.type.hasTag(FORALL) ?
2868 ((ForAll)sym.type).tvars :
2869 List.nil();
2870 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
2871 types.createMethodTypeWithReturn(sym.type.asMethodType(), site));
2872 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) {
2873 @Override
2874 public Symbol baseSymbol() {
2875 return sym;
2876 }
2877 };
2878 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
2879 newConstr,
2880 bestSoFar,
2881 allowBoxing,
2882 useVarargs);
2883 }
2884 }
2885 return bestSoFar;
2886 }
2887
2888 Symbol getMemberReference(DiagnosticPosition pos,
2889 Env<AttrContext> env,
2890 JCMemberReference referenceTree,
2891 Type site,
2892 Name name) {
2893
2894 site = types.capture(site);
2895
2896 ReferenceLookupHelper lookupHelper = makeReferenceLookupHelper(
2897 referenceTree, site, name, List.nil(), null, VARARITY);
2898
2899 Env<AttrContext> newEnv = env.dup(env.tree, env.info.dup());
2900 Symbol sym = lookupMethod(newEnv, env.tree.pos(), site.tsym,
2901 nilMethodCheck, lookupHelper);
2902
2903 env.info.pendingResolutionPhase = newEnv.info.pendingResolutionPhase;
2904
2905 return sym;
2906 }
2907
2908 ReferenceLookupHelper makeReferenceLookupHelper(JCMemberReference referenceTree,
2909 Type site,
2910 Name name,
2911 List<Type> argtypes,
2912 List<Type> typeargtypes,
2913 MethodResolutionPhase maxPhase) {
2914 if (!name.equals(names.init)) {
2915 //method reference
2916 return new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2917 } else if (site.hasTag(ARRAY)) {
2918 //array constructor reference
2919 return new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2920 } else {
2921 //class constructor reference
2922 return new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2923 }
2924 }
2925
2926 /**
2927 * Resolution of member references is typically done as a single
2928 * overload resolution step, where the argument types A are inferred from
2929 * the target functional descriptor.
2930 *
2931 * If the member reference is a method reference with a type qualifier,
2932 * a two-step lookup process is performed. The first step uses the
2933 * expected argument list A, while the second step discards the first
2934 * type from A (which is treated as a receiver type).
2935 *
2936 * There are two cases in which inference is performed: (i) if the member
2937 * reference is a constructor reference and the qualifier type is raw - in
2938 * which case diamond inference is used to infer a parameterization for the
2939 * type qualifier; (ii) if the member reference is an unbound reference
2940 * where the type qualifier is raw - in that case, during the unbound lookup
2941 * the receiver argument type is used to infer an instantiation for the raw
2942 * qualifier type.
2943 *
2944 * When a multi-step resolution process is exploited, the process of picking
2945 * the resulting symbol is delegated to an helper class {@link com.sun.tools.javac.comp.Resolve.ReferenceChooser}.
2946 *
2947 * This routine returns a pair (T,S), where S is the member reference symbol,
2948 * and T is the type of the class in which S is defined. This is necessary as
2949 * the type T might be dynamically inferred (i.e. if constructor reference
2950 * has a raw qualifier).
2951 */
2952 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(Env<AttrContext> env,
2953 JCMemberReference referenceTree,
2954 Type site,
2955 Name name,
2956 List<Type> argtypes,
2957 List<Type> typeargtypes,
2958 Type descriptor,
2959 MethodCheck methodCheck,
2960 InferenceContext inferenceContext,
2961 ReferenceChooser referenceChooser) {
2962
2963 //step 1 - bound lookup
2964 ReferenceLookupHelper boundLookupHelper = makeReferenceLookupHelper(
2965 referenceTree, site, name, argtypes, typeargtypes, VARARITY);
2966 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup());
2967 MethodResolutionContext boundSearchResolveContext = new MethodResolutionContext();
2968 boundSearchResolveContext.methodCheck = methodCheck;
2969 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(),
2970 site.tsym, boundSearchResolveContext, boundLookupHelper);
2971 ReferenceLookupResult boundRes = new ReferenceLookupResult(boundSym, boundSearchResolveContext);
2972
2973 //step 2 - unbound lookup
2974 Symbol unboundSym = methodNotFound;
2975 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup());
2976 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup(inferenceContext);
2977 ReferenceLookupResult unboundRes = referenceNotFound;
2978 if (unboundLookupHelper != null) {
2979 MethodResolutionContext unboundSearchResolveContext =
2980 new MethodResolutionContext();
2981 unboundSearchResolveContext.methodCheck = methodCheck;
2982 unboundSym = lookupMethod(unboundEnv, env.tree.pos(),
2983 site.tsym, unboundSearchResolveContext, unboundLookupHelper);
2984 unboundRes = new ReferenceLookupResult(unboundSym, unboundSearchResolveContext);
2985 }
2986
2987 //merge results
2988 Pair<Symbol, ReferenceLookupHelper> res;
2989 ReferenceLookupResult bestRes = referenceChooser.result(boundRes, unboundRes);
2990 res = new Pair<>(bestRes.sym,
2991 bestRes == unboundRes ? unboundLookupHelper : boundLookupHelper);
2992 env.info.pendingResolutionPhase = bestRes == unboundRes ?
2993 unboundEnv.info.pendingResolutionPhase :
2994 boundEnv.info.pendingResolutionPhase;
2995
2996 if (!res.fst.kind.isResolutionError()) {
2997 //handle sigpoly method references
2998 MethodSymbol msym = (MethodSymbol)res.fst;
2999 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) {
3000 env.info.pendingResolutionPhase = BASIC;
3001 res = new Pair<>(findPolymorphicSignatureInstance(msym, descriptor), res.snd);
3002 }
3003 }
3004
3005 return res;
3006 }
3007
3008 /**
3009 * This class is used to represent a method reference lookup result. It keeps track of two
3010 * things: (i) the symbol found during a method reference lookup and (ii) the static kind
3011 * of the lookup (see {@link com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind}).
3012 */
3013 static class ReferenceLookupResult {
3014
3015 /**
3016 * Static kind associated with a method reference lookup. Erroneous lookups end up with
3017 * the UNDEFINED kind; successful lookups will end up with either STATIC, NON_STATIC,
3018 * depending on whether all applicable candidates are static or non-static methods,
3019 * respectively. If a successful lookup has both static and non-static applicable methods,
3020 * its kind is set to BOTH.
3021 */
3022 enum StaticKind {
3023 STATIC,
3024 NON_STATIC,
3025 BOTH,
3026 UNDEFINED;
3027
3028 /**
3029 * Retrieve the static kind associated with a given (method) symbol.
3030 */
3031 static StaticKind from(Symbol s) {
3032 return s.isStatic() ?
3033 STATIC : NON_STATIC;
3034 }
3035
3036 /**
3037 * Merge two static kinds together.
3038 */
3039 static StaticKind reduce(StaticKind sk1, StaticKind sk2) {
3040 if (sk1 == UNDEFINED) {
3041 return sk2;
3042 } else if (sk2 == UNDEFINED) {
3043 return sk1;
3044 } else {
3045 return sk1 == sk2 ? sk1 : BOTH;
3046 }
3047 }
3048 }
3049
3050 /** The static kind. */
3051 StaticKind staticKind;
3052
3053 /** The lookup result. */
3054 Symbol sym;
3055
3056 ReferenceLookupResult(Symbol sym, MethodResolutionContext resolutionContext) {
3057 this(sym, staticKind(sym, resolutionContext));
3058 }
3059
3060 private ReferenceLookupResult(Symbol sym, StaticKind staticKind) {
3061 this.staticKind = staticKind;
3062 this.sym = sym;
3063 }
3064
3065 private static StaticKind staticKind(Symbol sym, MethodResolutionContext resolutionContext) {
3066 switch (sym.kind) {
3067 case MTH:
3068 case AMBIGUOUS:
3069 return resolutionContext.candidates.stream()
3070 .filter(c -> c.isApplicable() && c.step == resolutionContext.step)
3071 .map(c -> StaticKind.from(c.sym))
3072 .reduce(StaticKind::reduce)
3073 .orElse(StaticKind.UNDEFINED);
3074 default:
3075 return StaticKind.UNDEFINED;
3076 }
3077 }
3078
3079 /**
3080 * Does this result corresponds to a successful lookup (i.e. one where a method has been found?)
3081 */
3082 boolean isSuccess() {
3083 return staticKind != StaticKind.UNDEFINED;
3084 }
3085
3086 /**
3087 * Does this result have given static kind?
3088 */
3089 boolean hasKind(StaticKind sk) {
3090 return this.staticKind == sk;
3091 }
3092
3093 /**
3094 * Error recovery helper: can this lookup result be ignored (for the purpose of returning
3095 * some 'better' result) ?
3096 */
3097 boolean canIgnore() {
3098 switch (sym.kind) {
3099 case ABSENT_MTH:
3100 return true;
3101 case WRONG_MTH:
3102 InapplicableSymbolError errSym =
3103 (InapplicableSymbolError)sym.baseSymbol();
3104 return new Template(MethodCheckDiag.ARITY_MISMATCH.regex())
3105 .matches(errSym.errCandidate().snd);
3106 case WRONG_MTHS:
3107 InapplicableSymbolsError errSyms =
3108 (InapplicableSymbolsError)sym.baseSymbol();
3109 return errSyms.filterCandidates(errSyms.mapCandidates()).isEmpty();
3110 default:
3111 return false;
3112 }
3113 }
3114
3115 static ReferenceLookupResult error(Symbol sym) {
3116 return new ReferenceLookupResult(sym, StaticKind.UNDEFINED);
3117 }
3118 }
3119
3120 /**
3121 * This abstract class embodies the logic that converts one (bound lookup) or two (unbound lookup)
3122 * {@code ReferenceLookupResult} objects into a (@code Symbol), which is then regarded as the
3123 * result of method reference resolution.
3124 */
3125 abstract class ReferenceChooser {
3126 /**
3127 * Generate a result from a pair of lookup result objects. This method delegates to the
3128 * appropriate result generation routine.
3129 */
3130 ReferenceLookupResult result(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3131 return unboundRes != referenceNotFound ?
3132 unboundResult(boundRes, unboundRes) :
3133 boundResult(boundRes);
3134 }
3135
3136 /**
3137 * Generate a symbol from a given bound lookup result.
3138 */
3139 abstract ReferenceLookupResult boundResult(ReferenceLookupResult boundRes);
3140
3141 /**
3142 * Generate a symbol from a pair of bound/unbound lookup results.
3143 */
3144 abstract ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes);
3145 }
3146
3147 /**
3148 * This chooser implements the selection strategy used during a full lookup; this logic
3149 * is described in JLS SE 8 (15.3.2).
3150 */
3151 ReferenceChooser basicReferenceChooser = new ReferenceChooser() {
3152
3153 @Override
3154 ReferenceLookupResult boundResult(ReferenceLookupResult boundRes) {
3155 return !boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC) ?
3156 boundRes : //the search produces a non-static method
3157 ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.sym, false));
3158 }
3159
3160 @Override
3161 ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3162 if (boundRes.hasKind(StaticKind.STATIC) &&
3163 (!unboundRes.isSuccess() || unboundRes.hasKind(StaticKind.STATIC))) {
3164 //the first search produces a static method and no non-static method is applicable
3165 //during the second search
3166 return boundRes;
3167 } else if (unboundRes.hasKind(StaticKind.NON_STATIC) &&
3168 (!boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC))) {
3169 //the second search produces a non-static method and no static method is applicable
3170 //during the first search
3171 return unboundRes;
3172 } else if (boundRes.isSuccess() && unboundRes.isSuccess()) {
3173 //both searches produce some result; ambiguity (error recovery)
3174 return ReferenceLookupResult.error(ambiguityError(boundRes.sym, unboundRes.sym));
3175 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) {
3176 //Both searches failed to produce a result with correct staticness (i.e. first search
3177 //produces an non-static method). Alternatively, a given search produced a result
3178 //with the right staticness, but the other search has applicable methods with wrong
3179 //staticness (error recovery)
3180 return ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.isSuccess() ?
3181 boundRes.sym : unboundRes.sym, true));
3182 } else {
3183 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery)
3184 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ?
3185 unboundRes : boundRes;
3186 }
3187 }
3188 };
3189
3190 /**
3191 * This chooser implements the selection strategy used during an arity-based lookup; this logic
3192 * is described in JLS SE 8 (15.12.2.1).
3193 */
3194 ReferenceChooser structuralReferenceChooser = new ReferenceChooser() {
3195
3196 @Override
3197 ReferenceLookupResult boundResult(ReferenceLookupResult boundRes) {
3198 return (!boundRes.isSuccess() || !boundRes.hasKind(StaticKind.STATIC)) ?
3199 boundRes : //the search has at least one applicable non-static method
3200 ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.sym, false));
3201 }
3202
3203 @Override
3204 ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3205 if (boundRes.isSuccess() && !boundRes.hasKind(StaticKind.NON_STATIC)) {
3206 //the first serach has at least one applicable static method
3207 return boundRes;
3208 } else if (unboundRes.isSuccess() && !unboundRes.hasKind(StaticKind.STATIC)) {
3209 //the second search has at least one applicable non-static method
3210 return unboundRes;
3211 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) {
3212 //either the first search produces a non-static method, or second search produces
3213 //a non-static method (error recovery)
3214 return ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.isSuccess() ?
3215 boundRes.sym : unboundRes.sym, true));
3216 } else {
3217 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery)
3218 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ?
3219 unboundRes : boundRes;
3220 }
3221 }
3222 };
3223
3224 /**
3225 * Helper for defining custom method-like lookup logic; a lookup helper
3226 * provides hooks for (i) the actual lookup logic and (ii) accessing the
3227 * lookup result (this step might result in compiler diagnostics to be generated)
3228 */
3229 abstract class LookupHelper {
3230
3231 /** name of the symbol to lookup */
3232 Name name;
3233
3234 /** location in which the lookup takes place */
3235 Type site;
3236
3237 /** actual types used during the lookup */
3238 List<Type> argtypes;
3239
3240 /** type arguments used during the lookup */
3241 List<Type> typeargtypes;
3242
3243 /** Max overload resolution phase handled by this helper */
3244 MethodResolutionPhase maxPhase;
3245
3246 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3247 this.name = name;
3248 this.site = site;
3249 this.argtypes = argtypes;
3250 this.typeargtypes = typeargtypes;
3251 this.maxPhase = maxPhase;
3252 }
3253
3254 /**
3255 * Should lookup stop at given phase with given result
3256 */
3257 final boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
3258 return phase.ordinal() > maxPhase.ordinal() ||
3259 !sym.kind.isResolutionError() || sym.kind == AMBIGUOUS;
3260 }
3261
3262 /**
3263 * Search for a symbol under a given overload resolution phase - this method
3264 * is usually called several times, once per each overload resolution phase
3265 */
3266 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase);
3267
3268 /**
3269 * Dump overload resolution info
3270 */
3271 void debug(DiagnosticPosition pos, Symbol sym) {
3272 //do nothing
3273 }
3274
3275 /**
3276 * Validate the result of the lookup
3277 */
3278 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym);
3279 }
3280
3281 abstract class BasicLookupHelper extends LookupHelper {
3282
3283 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) {
3284 this(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY);
3285 }
3286
3287 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3288 super(name, site, argtypes, typeargtypes, maxPhase);
3289 }
3290
3291 @Override
3292 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3293 Symbol sym = doLookup(env, phase);
3294 if (sym.kind == AMBIGUOUS) {
3295 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
3296 sym = a_err.mergeAbstracts(site);
3297 }
3298 return sym;
3299 }
3300
3301 abstract Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase);
3302
3303 @Override
3304 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
3305 if (sym.kind.isResolutionError()) {
3306 //if nothing is found return the 'first' error
3307 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes);
3308 }
3309 return sym;
3310 }
3311
3312 @Override
3313 void debug(DiagnosticPosition pos, Symbol sym) {
3314 reportVerboseResolutionDiagnostic(pos, name, site, argtypes, typeargtypes, sym);
3315 }
3316 }
3317
3318 /**
3319 * Helper class for member reference lookup. A reference lookup helper
3320 * defines the basic logic for member reference lookup; a method gives
3321 * access to an 'unbound' helper used to perform an unbound member
3322 * reference lookup.
3323 */
3324 abstract class ReferenceLookupHelper extends LookupHelper {
3325
3326 /** The member reference tree */
3327 JCMemberReference referenceTree;
3328
3329 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3330 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3331 super(name, site, argtypes, typeargtypes, maxPhase);
3332 this.referenceTree = referenceTree;
3333 }
3334
3335 /**
3336 * Returns an unbound version of this lookup helper. By default, this
3337 * method returns an dummy lookup helper.
3338 */
3339 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3340 return null;
3341 }
3342
3343 /**
3344 * Get the kind of the member reference
3345 */
3346 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym);
3347
3348 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
3349 if (sym.kind == AMBIGUOUS) {
3350 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
3351 sym = a_err.mergeAbstracts(site);
3352 }
3353 //skip error reporting
3354 return sym;
3355 }
3356 }
3357
3358 /**
3359 * Helper class for method reference lookup. The lookup logic is based
3360 * upon Resolve.findMethod; in certain cases, this helper class has a
3361 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper).
3362 * In such cases, non-static lookup results are thrown away.
3363 */
3364 class MethodReferenceLookupHelper extends ReferenceLookupHelper {
3365
3366 /** The original method reference lookup site. */
3367 Type originalSite;
3368
3369 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3370 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3371 super(referenceTree, name, types.skipTypeVars(site, true), argtypes, typeargtypes, maxPhase);
3372 this.originalSite = site;
3373 }
3374
3375 @Override
3376 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3377 return findMethod(env, site, name, argtypes, typeargtypes,
3378 phase.isBoxingRequired(), phase.isVarargsRequired());
3379 }
3380
3381 @Override
3382 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3383 if (TreeInfo.isStaticSelector(referenceTree.expr, names)) {
3384 if (argtypes.nonEmpty() &&
3385 (argtypes.head.hasTag(NONE) ||
3386 types.isSubtypeUnchecked(inferenceContext.asUndetVar(argtypes.head), originalSite))) {
3387 return new UnboundMethodReferenceLookupHelper(referenceTree, name,
3388 originalSite, argtypes, typeargtypes, maxPhase);
3389 } else {
3390 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) {
3391 @Override
3392 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3393 return this;
3394 }
3395
3396 @Override
3397 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3398 return methodNotFound;
3399 }
3400
3401 @Override
3402 ReferenceKind referenceKind(Symbol sym) {
3403 Assert.error();
3404 return null;
3405 }
3406 };
3407 }
3408 } else {
3409 return super.unboundLookup(inferenceContext);
3410 }
3411 }
3412
3413 @Override
3414 ReferenceKind referenceKind(Symbol sym) {
3415 if (sym.isStatic()) {
3416 return ReferenceKind.STATIC;
3417 } else {
3418 Name selName = TreeInfo.name(referenceTree.getQualifierExpression());
3419 return selName != null && selName == names._super ?
3420 ReferenceKind.SUPER :
3421 ReferenceKind.BOUND;
3422 }
3423 }
3424 }
3425
3426 /**
3427 * Helper class for unbound method reference lookup. Essentially the same
3428 * as the basic method reference lookup helper; main difference is that static
3429 * lookup results are thrown away. If qualifier type is raw, an attempt to
3430 * infer a parameterized type is made using the first actual argument (that
3431 * would otherwise be ignored during the lookup).
3432 */
3433 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper {
3434
3435 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3436 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3437 super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase);
3438 if (site.isRaw() && !argtypes.head.hasTag(NONE)) {
3439 Type asSuperSite = types.asSuper(argtypes.head, site.tsym);
3440 this.site = types.skipTypeVars(asSuperSite, true);
3441 }
3442 }
3443
3444 @Override
3445 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3446 return this;
3447 }
3448
3449 @Override
3450 ReferenceKind referenceKind(Symbol sym) {
3451 return ReferenceKind.UNBOUND;
3452 }
3453 }
3454
3455 /**
3456 * Helper class for array constructor lookup; an array constructor lookup
3457 * is simulated by looking up a method that returns the array type specified
3458 * as qualifier, and that accepts a single int parameter (size of the array).
3459 */
3460 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper {
3461
3462 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
3463 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3464 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
3465 }
3466
3467 @Override
3468 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3469 WriteableScope sc = WriteableScope.create(syms.arrayClass);
3470 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym);
3471 arrayConstr.type = new MethodType(List.of(syms.intType), site, List.nil(), syms.methodClass);
3472 sc.enter(arrayConstr);
3473 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false);
3474 }
3475
3476 @Override
3477 ReferenceKind referenceKind(Symbol sym) {
3478 return ReferenceKind.ARRAY_CTOR;
3479 }
3480 }
3481
3482 /**
3483 * Helper class for constructor reference lookup. The lookup logic is based
3484 * upon either Resolve.findMethod or Resolve.findDiamond - depending on
3485 * whether the constructor reference needs diamond inference (this is the case
3486 * if the qualifier type is raw). A special erroneous symbol is returned
3487 * if the lookup returns the constructor of an inner class and there's no
3488 * enclosing instance in scope.
3489 */
3490 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper {
3491
3492 boolean needsInference;
3493
3494 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
3495 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3496 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
3497 if (site.isRaw()) {
3498 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym, site.getMetadata());
3499 needsInference = true;
3500 }
3501 }
3502
3503 @Override
3504 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3505 Symbol sym = needsInference ?
3506 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) :
3507 findMethod(env, site, name, argtypes, typeargtypes,
3508 phase.isBoxingRequired(), phase.isVarargsRequired());
3509 return enclosingInstanceMissing(env, site) ? new BadConstructorReferenceError(sym) : sym;
3510 }
3511
3512 @Override
3513 ReferenceKind referenceKind(Symbol sym) {
3514 return site.getEnclosingType().hasTag(NONE) ?
3515 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER;
3516 }
3517 }
3518
3519 /**
3520 * Main overload resolution routine. On each overload resolution step, a
3521 * lookup helper class is used to perform the method/constructor lookup;
3522 * at the end of the lookup, the helper is used to validate the results
3523 * (this last step might trigger overload resolution diagnostics).
3524 */
3525 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, MethodCheck methodCheck, LookupHelper lookupHelper) {
3526 MethodResolutionContext resolveContext = new MethodResolutionContext();
3527 resolveContext.methodCheck = methodCheck;
3528 return lookupMethod(env, pos, location, resolveContext, lookupHelper);
3529 }
3530
3531 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location,
3532 MethodResolutionContext resolveContext, LookupHelper lookupHelper) {
3533 MethodResolutionContext prevResolutionContext = currentResolutionContext;
3534 try {
3535 Symbol bestSoFar = methodNotFound;
3536 currentResolutionContext = resolveContext;
3537 for (MethodResolutionPhase phase : methodResolutionSteps) {
3538 if (lookupHelper.shouldStop(bestSoFar, phase))
3539 break;
3540 MethodResolutionPhase prevPhase = currentResolutionContext.step;
3541 Symbol prevBest = bestSoFar;
3542 currentResolutionContext.step = phase;
3543 Symbol sym = lookupHelper.lookup(env, phase);
3544 lookupHelper.debug(pos, sym);
3545 bestSoFar = phase.mergeResults(bestSoFar, sym);
3546 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase;
3547 }
3548 return lookupHelper.access(env, pos, location, bestSoFar);
3549 } finally {
3550 currentResolutionContext = prevResolutionContext;
3551 }
3552 }
3553
3554 /**
3555 * Resolve `c.name' where name == this or name == super.
3556 * @param pos The position to use for error reporting.
3557 * @param env The environment current at the expression.
3558 * @param c The qualifier.
3559 * @param name The identifier's name.
3560 */
3561 Symbol resolveSelf(DiagnosticPosition pos,
3562 Env<AttrContext> env,
3563 TypeSymbol c,
3564 Name name) {
3565 Env<AttrContext> env1 = env;
3566 boolean staticOnly = false;
3567 while (env1.outer != null) {
3568 if (isStatic(env1)) staticOnly = true;
3569 if (env1.enclClass.sym == c) {
3570 Symbol sym = env1.info.scope.findFirst(name);
3571 if (sym != null) {
3572 if (staticOnly) sym = new StaticError(sym);
3573 return accessBase(sym, pos, env.enclClass.sym.type,
3574 name, true);
3575 }
3576 }
3577 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
3578 env1 = env1.outer;
3579 }
3580 if (c.isInterface() &&
3581 name == names._super && !isStatic(env) &&
3582 types.isDirectSuperInterface(c, env.enclClass.sym)) {
3583 //this might be a default super call if one of the superinterfaces is 'c'
3584 for (Type t : pruneInterfaces(env.enclClass.type)) {
3585 if (t.tsym == c) {
3586 env.info.defaultSuperCallSite = t;
3587 return new VarSymbol(0, names._super,
3588 types.asSuper(env.enclClass.type, c), env.enclClass.sym);
3589 }
3590 }
3591 //find a direct super type that is a subtype of 'c'
3592 for (Type i : types.directSupertypes(env.enclClass.type)) {
3593 if (i.tsym.isSubClass(c, types) && i.tsym != c) {
3594 log.error(pos,
3595 Errors.IllegalDefaultSuperCall(c,
3596 Fragments.RedundantSupertype(c, i)));
3597 return syms.errSymbol;
3598 }
3599 }
3600 Assert.error();
3601 }
3602 log.error(pos, Errors.NotEnclClass(c));
3603 return syms.errSymbol;
3604 }
3605 //where
3606 private List<Type> pruneInterfaces(Type t) {
3607 ListBuffer<Type> result = new ListBuffer<>();
3608 for (Type t1 : types.interfaces(t)) {
3609 boolean shouldAdd = true;
3610 for (Type t2 : types.directSupertypes(t)) {
3611 if (t1 != t2 && types.isSubtypeNoCapture(t2, t1)) {
3612 shouldAdd = false;
3613 }
3614 }
3615 if (shouldAdd) {
3616 result.append(t1);
3617 }
3618 }
3619 return result.toList();
3620 }
3621
3622
3623 /**
3624 * Resolve `c.this' for an enclosing class c that contains the
3625 * named member.
3626 * @param pos The position to use for error reporting.
3627 * @param env The environment current at the expression.
3628 * @param member The member that must be contained in the result.
3629 */
3630 Symbol resolveSelfContaining(DiagnosticPosition pos,
3631 Env<AttrContext> env,
3632 Symbol member,
3633 boolean isSuperCall) {
3634 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall);
3635 if (sym == null) {
3636 log.error(pos, Errors.EnclClassRequired(member));
3637 return syms.errSymbol;
3638 } else {
3639 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true);
3640 }
3641 }
3642
3643 boolean enclosingInstanceMissing(Env<AttrContext> env, Type type) {
3644 if (type.hasTag(CLASS) && type.getEnclosingType().hasTag(CLASS)) {
3645 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false);
3646 return encl == null || encl.kind.isResolutionError();
3647 }
3648 return false;
3649 }
3650
3651 private Symbol resolveSelfContainingInternal(Env<AttrContext> env,
3652 Symbol member,
3653 boolean isSuperCall) {
3654 Name name = names._this;
3655 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
3656 boolean staticOnly = false;
3657 if (env1 != null) {
3658 while (env1 != null && env1.outer != null) {
3659 if (isStatic(env1)) staticOnly = true;
3660 if (env1.enclClass.sym.isSubClass(member.owner.enclClass(), types)) {
3661 Symbol sym = env1.info.scope.findFirst(name);
3662 if (sym != null) {
3663 if (staticOnly) sym = new StaticError(sym);
3664 return sym;
3665 }
3666 }
3667 if ((env1.enclClass.sym.flags() & STATIC) != 0)
3668 staticOnly = true;
3669 env1 = env1.outer;
3670 }
3671 }
3672 return null;
3673 }
3674
3675 /**
3676 * Resolve an appropriate implicit this instance for t's container.
3677 * JLS 8.8.5.1 and 15.9.2
3678 */
3679 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
3680 return resolveImplicitThis(pos, env, t, false);
3681 }
3682
3683 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
3684 Type thisType = (t.tsym.owner.kind.matches(KindSelector.VAL_MTH)
3685 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
3686 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
3687 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym) {
3688 log.error(pos, Errors.CantRefBeforeCtorCalled("this"));
3689 }
3690 return thisType;
3691 }
3692
3693 /* ***************************************************************************
3694 * ResolveError classes, indicating error situations when accessing symbols
3695 ****************************************************************************/
3696
3697 //used by TransTypes when checking target type of synthetic cast
3698 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) {
3699 AccessError error = new AccessError(env, env.enclClass.type, type.tsym);
3700 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null);
3701 }
3702 //where
3703 private void logResolveError(ResolveError error,
3704 DiagnosticPosition pos,
3705 Symbol location,
3706 Type site,
3707 Name name,
3708 List<Type> argtypes,
3709 List<Type> typeargtypes) {
3710 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
3711 pos, location, site, name, argtypes, typeargtypes);
3712 if (d != null) {
3713 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
3714 log.report(d);
3715 }
3716 }
3717
3718 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
3719
3720 public Object methodArguments(List<Type> argtypes) {
3721 if (argtypes == null || argtypes.isEmpty()) {
3722 return noArgs;
3723 } else {
3724 ListBuffer<Object> diagArgs = new ListBuffer<>();
3725 for (Type t : argtypes) {
3726 if (t.hasTag(DEFERRED)) {
3727 diagArgs.append(((DeferredAttr.DeferredType)t).tree);
3728 } else {
3729 diagArgs.append(t);
3730 }
3731 }
3732 return diagArgs;
3733 }
3734 }
3735
3736 /**
3737 * Root class for resolution errors. Subclass of ResolveError
3738 * represent a different kinds of resolution error - as such they must
3739 * specify how they map into concrete compiler diagnostics.
3740 */
3741 abstract class ResolveError extends Symbol {
3742
3743 /** The name of the kind of error, for debugging only. */
3744 final String debugName;
3745
3746 ResolveError(Kind kind, String debugName) {
3747 super(kind, 0, null, null, null);
3748 this.debugName = debugName;
3749 }
3750
3751 @Override @DefinedBy(Api.LANGUAGE_MODEL)
3752 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
3753 throw new AssertionError();
3754 }
3755
3756 @Override
3757 public String toString() {
3758 return debugName;
3759 }
3760
3761 @Override
3762 public boolean exists() {
3763 return false;
3764 }
3765
3766 @Override
3767 public boolean isStatic() {
3768 return false;
3769 }
3770
3771 /**
3772 * Create an external representation for this erroneous symbol to be
3773 * used during attribution - by default this returns the symbol of a
3774 * brand new error type which stores the original type found
3775 * during resolution.
3776 *
3777 * @param name the name used during resolution
3778 * @param location the location from which the symbol is accessed
3779 */
3780 protected Symbol access(Name name, TypeSymbol location) {
3781 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3782 }
3783
3784 /**
3785 * Create a diagnostic representing this resolution error.
3786 *
3787 * @param dkind The kind of the diagnostic to be created (e.g error).
3788 * @param pos The position to be used for error reporting.
3789 * @param site The original type from where the selection took place.
3790 * @param name The name of the symbol to be resolved.
3791 * @param argtypes The invocation's value arguments,
3792 * if we looked for a method.
3793 * @param typeargtypes The invocation's type arguments,
3794 * if we looked for a method.
3795 */
3796 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3797 DiagnosticPosition pos,
3798 Symbol location,
3799 Type site,
3800 Name name,
3801 List<Type> argtypes,
3802 List<Type> typeargtypes);
3803 }
3804
3805 /**
3806 * This class is the root class of all resolution errors caused by
3807 * an invalid symbol being found during resolution.
3808 */
3809 abstract class InvalidSymbolError extends ResolveError {
3810
3811 /** The invalid symbol found during resolution */
3812 Symbol sym;
3813
3814 InvalidSymbolError(Kind kind, Symbol sym, String debugName) {
3815 super(kind, debugName);
3816 this.sym = sym;
3817 }
3818
3819 @Override
3820 public boolean exists() {
3821 return true;
3822 }
3823
3824 @Override
3825 public String toString() {
3826 return super.toString() + " wrongSym=" + sym;
3827 }
3828
3829 @Override
3830 public Symbol access(Name name, TypeSymbol location) {
3831 if (!sym.kind.isResolutionError() && sym.kind.matches(KindSelector.TYP))
3832 return types.createErrorType(name, location, sym.type).tsym;
3833 else
3834 return sym;
3835 }
3836 }
3837
3838 class BadVarTypeError extends ResolveError {
3839 BadVarTypeError() {
3840 super(Kind.BAD_VAR, "bad var use");
3841 }
3842
3843 @Override
3844 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
3845 return diags.create(dkind, log.currentSource(), pos, "illegal.ref.to.var.type");
3846 }
3847 }
3848
3849 /**
3850 * InvalidSymbolError error class indicating that a symbol matching a
3851 * given name does not exists in a given site.
3852 */
3853 class SymbolNotFoundError extends ResolveError {
3854
3855 SymbolNotFoundError(Kind kind) {
3856 this(kind, "symbol not found error");
3857 }
3858
3859 SymbolNotFoundError(Kind kind, String debugName) {
3860 super(kind, debugName);
3861 }
3862
3863 @Override
3864 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3865 DiagnosticPosition pos,
3866 Symbol location,
3867 Type site,
3868 Name name,
3869 List<Type> argtypes,
3870 List<Type> typeargtypes) {
3871 argtypes = argtypes == null ? List.nil() : argtypes;
3872 typeargtypes = typeargtypes == null ? List.nil() : typeargtypes;
3873 if (name == names.error)
3874 return null;
3875
3876 boolean hasLocation = false;
3877 if (location == null) {
3878 location = site.tsym;
3879 }
3880 if (!location.name.isEmpty()) {
3881 if (location.kind == PCK && !site.tsym.exists()) {
3882 return diags.create(dkind, log.currentSource(), pos,
3883 "doesnt.exist", location);
3884 }
3885 hasLocation = !location.name.equals(names._this) &&
3886 !location.name.equals(names._super);
3887 }
3888 boolean isConstructor = name == names.init;
3889 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : kind.absentKind();
3890 Name idname = isConstructor ? site.tsym.name : name;
3891 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
3892 if (hasLocation) {
3893 return diags.create(dkind, log.currentSource(), pos,
3894 errKey, kindname, idname, //symbol kindname, name
3895 typeargtypes, args(argtypes), //type parameters and arguments (if any)
3896 getLocationDiag(location, site)); //location kindname, type
3897 }
3898 else {
3899 return diags.create(dkind, log.currentSource(), pos,
3900 errKey, kindname, idname, //symbol kindname, name
3901 typeargtypes, args(argtypes)); //type parameters and arguments (if any)
3902 }
3903 }
3904 //where
3905 private Object args(List<Type> args) {
3906 return args.isEmpty() ? args : methodArguments(args);
3907 }
3908
3909 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
3910 String key = "cant.resolve";
3911 String suffix = hasLocation ? ".location" : "";
3912 switch (kindname) {
3913 case METHOD:
3914 case CONSTRUCTOR: {
3915 suffix += ".args";
3916 suffix += hasTypeArgs ? ".params" : "";
3917 }
3918 }
3919 return key + suffix;
3920 }
3921 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
3922 if (location.kind == VAR) {
3923 return diags.fragment(Fragments.Location1(kindName(location),
3924 location,
3925 location.type));
3926 } else {
3927 return diags.fragment(Fragments.Location(typeKindName(site),
3928 site,
3929 null));
3930 }
3931 }
3932 }
3933
3934 /**
3935 * InvalidSymbolError error class indicating that a given symbol
3936 * (either a method, a constructor or an operand) is not applicable
3937 * given an actual arguments/type argument list.
3938 */
3939 class InapplicableSymbolError extends ResolveError {
3940
3941 protected MethodResolutionContext resolveContext;
3942
3943 InapplicableSymbolError(MethodResolutionContext context) {
3944 this(WRONG_MTH, "inapplicable symbol error", context);
3945 }
3946
3947 protected InapplicableSymbolError(Kind kind, String debugName, MethodResolutionContext context) {
3948 super(kind, debugName);
3949 this.resolveContext = context;
3950 }
3951
3952 @Override
3953 public String toString() {
3954 return super.toString();
3955 }
3956
3957 @Override
3958 public boolean exists() {
3959 return true;
3960 }
3961
3962 @Override
3963 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3964 DiagnosticPosition pos,
3965 Symbol location,
3966 Type site,
3967 Name name,
3968 List<Type> argtypes,
3969 List<Type> typeargtypes) {
3970 if (name == names.error)
3971 return null;
3972
3973 Pair<Symbol, JCDiagnostic> c = errCandidate();
3974 if (compactMethodDiags) {
3975 JCDiagnostic simpleDiag =
3976 MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, c.snd);
3977 if (simpleDiag != null) {
3978 return simpleDiag;
3979 }
3980 }
3981 Symbol ws = c.fst.asMemberOf(site, types);
3982 return diags.create(dkind, log.currentSource(), pos,
3983 "cant.apply.symbol",
3984 kindName(ws),
3985 ws.name == names.init ? ws.owner.name : ws.name,
3986 methodArguments(ws.type.getParameterTypes()),
3987 methodArguments(argtypes),
3988 kindName(ws.owner),
3989 ws.owner.type,
3990 c.snd);
3991 }
3992
3993 @Override
3994 public Symbol access(Name name, TypeSymbol location) {
3995 Symbol sym = bestCandidate();
3996 return types.createErrorType(name, location, sym != null ? sym.type : syms.errSymbol.type).tsym;
3997 }
3998
3999 protected Symbol bestCandidate() {
4000 return errCandidate().fst;
4001 }
4002
4003 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4004 Candidate bestSoFar = null;
4005 for (Candidate c : resolveContext.candidates) {
4006 if (c.isApplicable()) continue;
4007 bestSoFar = c;
4008 }
4009 Assert.checkNonNull(bestSoFar);
4010 return new Pair<>(bestSoFar.sym, bestSoFar.details);
4011 }
4012 }
4013
4014 /**
4015 * ResolveError error class indicating that a symbol (either methods, constructors or operand)
4016 * is not applicable given an actual arguments/type argument list.
4017 */
4018 class InapplicableSymbolsError extends InapplicableSymbolError {
4019
4020 InapplicableSymbolsError(MethodResolutionContext context) {
4021 super(WRONG_MTHS, "inapplicable symbols", context);
4022 }
4023
4024 @Override
4025 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4026 DiagnosticPosition pos,
4027 Symbol location,
4028 Type site,
4029 Name name,
4030 List<Type> argtypes,
4031 List<Type> typeargtypes) {
4032 Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates();
4033 Map<Symbol, JCDiagnostic> filteredCandidates = compactMethodDiags ?
4034 filterCandidates(candidatesMap) :
4035 mapCandidates();
4036 if (filteredCandidates.isEmpty()) {
4037 filteredCandidates = candidatesMap;
4038 }
4039 boolean truncatedDiag = candidatesMap.size() != filteredCandidates.size();
4040 if (filteredCandidates.size() > 1) {
4041 JCDiagnostic err = diags.create(dkind,
4042 null,
4043 truncatedDiag ?
4044 EnumSet.of(DiagnosticFlag.COMPRESSED) :
4045 EnumSet.noneOf(DiagnosticFlag.class),
4046 log.currentSource(),
4047 pos,
4048 "cant.apply.symbols",
4049 name == names.init ? KindName.CONSTRUCTOR : kind.absentKind(),
4050 name == names.init ? site.tsym.name : name,
4051 methodArguments(argtypes));
4052 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(filteredCandidates, site));
4053 } else if (filteredCandidates.size() == 1) {
4054 Map.Entry<Symbol, JCDiagnostic> _e =
4055 filteredCandidates.entrySet().iterator().next();
4056 final Pair<Symbol, JCDiagnostic> p = new Pair<>(_e.getKey(), _e.getValue());
4057 JCDiagnostic d = new InapplicableSymbolError(resolveContext) {
4058 @Override
4059 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4060 return p;
4061 }
4062 }.getDiagnostic(dkind, pos,
4063 location, site, name, argtypes, typeargtypes);
4064 if (truncatedDiag) {
4065 d.setFlag(DiagnosticFlag.COMPRESSED);
4066 }
4067 return d;
4068 } else {
4069 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
4070 location, site, name, argtypes, typeargtypes);
4071 }
4072 }
4073 //where
4074 private Map<Symbol, JCDiagnostic> mapCandidates() {
4075 MostSpecificMap candidates = new MostSpecificMap();
4076 for (Candidate c : resolveContext.candidates) {
4077 if (c.isApplicable()) continue;
4078 candidates.put(c);
4079 }
4080 return candidates;
4081 }
4082
4083 @SuppressWarnings("serial")
4084 private class MostSpecificMap extends LinkedHashMap<Symbol, JCDiagnostic> {
4085 private void put(Candidate c) {
4086 ListBuffer<Symbol> overridden = new ListBuffer<>();
4087 for (Symbol s : keySet()) {
4088 if (s == c.sym) {
4089 continue;
4090 }
4091 if (c.sym.overrides(s, (TypeSymbol)s.owner, types, false)) {
4092 overridden.add(s);
4093 } else if (s.overrides(c.sym, (TypeSymbol)c.sym.owner, types, false)) {
4094 return;
4095 }
4096 }
4097 for (Symbol s : overridden) {
4098 remove(s);
4099 }
4100 put(c.sym, c.details);
4101 }
4102 }
4103
4104 Map<Symbol, JCDiagnostic> filterCandidates(Map<Symbol, JCDiagnostic> candidatesMap) {
4105 Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<>();
4106 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
4107 JCDiagnostic d = _entry.getValue();
4108 if (!new Template(MethodCheckDiag.ARITY_MISMATCH.regex()).matches(d)) {
4109 candidates.put(_entry.getKey(), d);
4110 }
4111 }
4112 return candidates;
4113 }
4114
4115 private List<JCDiagnostic> candidateDetails(Map<Symbol, JCDiagnostic> candidatesMap, Type site) {
4116 List<JCDiagnostic> details = List.nil();
4117 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
4118 Symbol sym = _entry.getKey();
4119 JCDiagnostic detailDiag =
4120 diags.fragment(Fragments.InapplicableMethod(Kinds.kindName(sym),
4121 sym.location(site, types),
4122 sym.asMemberOf(site, types),
4123 _entry.getValue()));
4124 details = details.prepend(detailDiag);
4125 }
4126 //typically members are visited in reverse order (see Scope)
4127 //so we need to reverse the candidate list so that candidates
4128 //conform to source order
4129 return details;
4130 }
4131
4132 @Override
4133 protected Symbol bestCandidate() {
4134 Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates();
4135 Map<Symbol, JCDiagnostic> filteredCandidates = filterCandidates(candidatesMap);
4136 if (filteredCandidates.size() == 1) {
4137 return filteredCandidates.keySet().iterator().next();
4138 }
4139 return null;
4140 }
4141 }
4142
4143 /**
4144 * DiamondError error class indicating that a constructor symbol is not applicable
4145 * given an actual arguments/type argument list using diamond inference.
4146 */
4147 class DiamondError extends InapplicableSymbolError {
4148
4149 Symbol sym;
4150
4151 public DiamondError(Symbol sym, MethodResolutionContext context) {
4152 super(sym.kind, "diamondError", context);
4153 this.sym = sym;
4154 }
4155
4156 JCDiagnostic getDetails() {
4157 return (sym.kind == WRONG_MTH) ?
4158 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd :
4159 null;
4160 }
4161
4162 @Override
4163 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
4164 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4165 JCDiagnostic details = getDetails();
4166 if (details != null && compactMethodDiags) {
4167 JCDiagnostic simpleDiag =
4168 MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, details);
4169 if (simpleDiag != null) {
4170 return simpleDiag;
4171 }
4172 }
4173 String key = details == null ?
4174 "cant.apply.diamond" :
4175 "cant.apply.diamond.1";
4176 return diags.create(dkind, log.currentSource(), pos, key,
4177 Fragments.Diamond(site.tsym), details);
4178 }
4179 }
4180
4181 /**
4182 * An InvalidSymbolError error class indicating that a symbol is not
4183 * accessible from a given site
4184 */
4185 class AccessError extends InvalidSymbolError {
4186
4187 private Env<AttrContext> env;
4188 private Type site;
4189
4190 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
4191 super(HIDDEN, sym, "access error");
4192 this.env = env;
4193 this.site = site;
4194 }
4195
4196 @Override
4197 public boolean exists() {
4198 return false;
4199 }
4200
4201 @Override
4202 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4203 DiagnosticPosition pos,
4204 Symbol location,
4205 Type site,
4206 Name name,
4207 List<Type> argtypes,
4208 List<Type> typeargtypes) {
4209 if (sym.name == names.init && sym.owner != site.tsym) {
4210 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
4211 pos, location, site, name, argtypes, typeargtypes);
4212 }
4213 else if ((sym.flags() & PUBLIC) != 0
4214 || (env != null && this.site != null
4215 && !isAccessible(env, this.site))) {
4216 if (sym.owner.kind == PCK) {
4217 return diags.create(dkind, log.currentSource(),
4218 pos, "not.def.access.package.cant.access",
4219 sym, sym.location(), inaccessiblePackageReason(env, sym.packge()));
4220 } else if ( sym.packge() != syms.rootPackage
4221 && !symbolPackageVisible(env, sym)) {
4222 return diags.create(dkind, log.currentSource(),
4223 pos, "not.def.access.class.intf.cant.access.reason",
4224 sym, sym.location(), sym.location().packge(),
4225 inaccessiblePackageReason(env, sym.packge()));
4226 } else {
4227 return diags.create(dkind, log.currentSource(),
4228 pos, "not.def.access.class.intf.cant.access",
4229 sym, sym.location());
4230 }
4231 }
4232 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
4233 return diags.create(dkind, log.currentSource(),
4234 pos, "report.access", sym,
4235 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
4236 sym.location());
4237 }
4238 else {
4239 return diags.create(dkind, log.currentSource(),
4240 pos, "not.def.public.cant.access", sym, sym.location());
4241 }
4242 }
4243
4244 private String toString(Type type) {
4245 StringBuilder sb = new StringBuilder();
4246 sb.append(type);
4247 if (type != null) {
4248 sb.append("[tsym:").append(type.tsym);
4249 if (type.tsym != null)
4250 sb.append("packge:").append(type.tsym.packge());
4251 sb.append("]");
4252 }
4253 return sb.toString();
4254 }
4255 }
4256
4257 class InvisibleSymbolError extends InvalidSymbolError {
4258
4259 private final Env<AttrContext> env;
4260 private final boolean suppressError;
4261
4262 InvisibleSymbolError(Env<AttrContext> env, boolean suppressError, Symbol sym) {
4263 super(HIDDEN, sym, "invisible class error");
4264 this.env = env;
4265 this.suppressError = suppressError;
4266 this.name = sym.name;
4267 }
4268
4269 @Override
4270 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4271 DiagnosticPosition pos,
4272 Symbol location,
4273 Type site,
4274 Name name,
4275 List<Type> argtypes,
4276 List<Type> typeargtypes) {
4277 if (suppressError)
4278 return null;
4279
4280 if (sym.kind == PCK) {
4281 JCDiagnostic details = inaccessiblePackageReason(env, sym.packge());
4282 return diags.create(dkind, log.currentSource(),
4283 pos, "package.not.visible", sym, details);
4284 }
4285
4286 JCDiagnostic details = inaccessiblePackageReason(env, sym.packge());
4287
4288 if (pos.getTree() != null) {
4289 Symbol o = sym;
4290 JCTree tree = pos.getTree();
4291
4292 while (o.kind != PCK && tree.hasTag(SELECT)) {
4293 o = o.owner;
4294 tree = ((JCFieldAccess) tree).selected;
4295 }
4296
4297 if (o.kind == PCK) {
4298 pos = tree.pos();
4299
4300 return diags.create(dkind, log.currentSource(),
4301 pos, "package.not.visible", o, details);
4302 }
4303 }
4304
4305 return diags.create(dkind, log.currentSource(),
4306 pos, "not.def.access.package.cant.access", sym, sym.packge(), details);
4307 }
4308 }
4309
4310 JCDiagnostic inaccessiblePackageReason(Env<AttrContext> env, PackageSymbol sym) {
4311 //no dependency:
4312 if (!env.toplevel.modle.readModules.contains(sym.modle)) {
4313 //does not read:
4314 if (sym.modle != syms.unnamedModule) {
4315 if (env.toplevel.modle != syms.unnamedModule) {
4316 return diags.fragment(Fragments.NotDefAccessDoesNotRead(env.toplevel.modle,
4317 sym,
4318 sym.modle));
4319 } else {
4320 return diags.fragment(Fragments.NotDefAccessDoesNotReadFromUnnamed(sym,
4321 sym.modle));
4322 }
4323 } else {
4324 return diags.fragment(Fragments.NotDefAccessDoesNotReadUnnamed(sym,
4325 env.toplevel.modle));
4326 }
4327 } else {
4328 if (sym.packge().modle.exports.stream().anyMatch(e -> e.packge == sym)) {
4329 //not exported to this module:
4330 if (env.toplevel.modle != syms.unnamedModule) {
4331 return diags.fragment(Fragments.NotDefAccessNotExportedToModule(sym,
4332 sym.modle,
4333 env.toplevel.modle));
4334 } else {
4335 return diags.fragment(Fragments.NotDefAccessNotExportedToModuleFromUnnamed(sym,
4336 sym.modle));
4337 }
4338 } else {
4339 //not exported:
4340 if (env.toplevel.modle != syms.unnamedModule) {
4341 return diags.fragment(Fragments.NotDefAccessNotExported(sym,
4342 sym.modle));
4343 } else {
4344 return diags.fragment(Fragments.NotDefAccessNotExportedFromUnnamed(sym,
4345 sym.modle));
4346 }
4347 }
4348 }
4349 }
4350
4351 /**
4352 * InvalidSymbolError error class indicating that an instance member
4353 * has erroneously been accessed from a static context.
4354 */
4355 class StaticError extends InvalidSymbolError {
4356
4357 StaticError(Symbol sym) {
4358 super(STATICERR, sym, "static error");
4359 }
4360
4361 @Override
4362 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4363 DiagnosticPosition pos,
4364 Symbol location,
4365 Type site,
4366 Name name,
4367 List<Type> argtypes,
4368 List<Type> typeargtypes) {
4369 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS))
4370 ? types.erasure(sym.type).tsym
4371 : sym);
4372 return diags.create(dkind, log.currentSource(), pos,
4373 "non-static.cant.be.ref", kindName(sym), errSym);
4374 }
4375 }
4376
4377 /**
4378 * InvalidSymbolError error class indicating that a pair of symbols
4379 * (either methods, constructors or operands) are ambiguous
4380 * given an actual arguments/type argument list.
4381 */
4382 class AmbiguityError extends ResolveError {
4383
4384 /** The other maximally specific symbol */
4385 List<Symbol> ambiguousSyms = List.nil();
4386
4387 @Override
4388 public boolean exists() {
4389 return true;
4390 }
4391
4392 AmbiguityError(Symbol sym1, Symbol sym2) {
4393 super(AMBIGUOUS, "ambiguity error");
4394 ambiguousSyms = flatten(sym2).appendList(flatten(sym1));
4395 }
4396
4397 private List<Symbol> flatten(Symbol sym) {
4398 if (sym.kind == AMBIGUOUS) {
4399 return ((AmbiguityError)sym.baseSymbol()).ambiguousSyms;
4400 } else {
4401 return List.of(sym);
4402 }
4403 }
4404
4405 AmbiguityError addAmbiguousSymbol(Symbol s) {
4406 ambiguousSyms = ambiguousSyms.prepend(s);
4407 return this;
4408 }
4409
4410 @Override
4411 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4412 DiagnosticPosition pos,
4413 Symbol location,
4414 Type site,
4415 Name name,
4416 List<Type> argtypes,
4417 List<Type> typeargtypes) {
4418 List<Symbol> diagSyms = ambiguousSyms.reverse();
4419 Symbol s1 = diagSyms.head;
4420 Symbol s2 = diagSyms.tail.head;
4421 Name sname = s1.name;
4422 if (sname == names.init) sname = s1.owner.name;
4423 return diags.create(dkind, log.currentSource(),
4424 pos, "ref.ambiguous", sname,
4425 kindName(s1),
4426 s1,
4427 s1.location(site, types),
4428 kindName(s2),
4429 s2,
4430 s2.location(site, types));
4431 }
4432
4433 /**
4434 * If multiple applicable methods are found during overload and none of them
4435 * is more specific than the others, attempt to merge their signatures.
4436 */
4437 Symbol mergeAbstracts(Type site) {
4438 List<Symbol> ambiguousInOrder = ambiguousSyms.reverse();
4439 return types.mergeAbstracts(ambiguousInOrder, site, true).orElse(this);
4440 }
4441
4442 @Override
4443 protected Symbol access(Name name, TypeSymbol location) {
4444 Symbol firstAmbiguity = ambiguousSyms.last();
4445 return firstAmbiguity.kind == TYP ?
4446 types.createErrorType(name, location, firstAmbiguity.type).tsym :
4447 firstAmbiguity;
4448 }
4449 }
4450
4451 class BadVarargsMethod extends ResolveError {
4452
4453 ResolveError delegatedError;
4454
4455 BadVarargsMethod(ResolveError delegatedError) {
4456 super(delegatedError.kind, "badVarargs");
4457 this.delegatedError = delegatedError;
4458 }
4459
4460 @Override
4461 public Symbol baseSymbol() {
4462 return delegatedError.baseSymbol();
4463 }
4464
4465 @Override
4466 protected Symbol access(Name name, TypeSymbol location) {
4467 return delegatedError.access(name, location);
4468 }
4469
4470 @Override
4471 public boolean exists() {
4472 return true;
4473 }
4474
4475 @Override
4476 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4477 return delegatedError.getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes);
4478 }
4479 }
4480
4481 /**
4482 * BadMethodReferenceError error class indicating that a method reference symbol has been found,
4483 * but with the wrong staticness.
4484 */
4485 class BadMethodReferenceError extends StaticError {
4486
4487 boolean unboundLookup;
4488
4489 public BadMethodReferenceError(Symbol sym, boolean unboundLookup) {
4490 super(sym);
4491 this.unboundLookup = unboundLookup;
4492 }
4493
4494 @Override
4495 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4496 final String key;
4497 if (!unboundLookup) {
4498 key = "bad.static.method.in.bound.lookup";
4499 } else if (sym.isStatic()) {
4500 key = "bad.static.method.in.unbound.lookup";
4501 } else {
4502 key = "bad.instance.method.in.unbound.lookup";
4503 }
4504 return sym.kind.isResolutionError() ?
4505 ((ResolveError)sym).getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes) :
4506 diags.create(dkind, log.currentSource(), pos, key, Kinds.kindName(sym), sym);
4507 }
4508 }
4509
4510 /**
4511 * BadConstructorReferenceError error class indicating that a constructor reference symbol has been found,
4512 * but pointing to a class for which an enclosing instance is not available.
4513 */
4514 class BadConstructorReferenceError extends InvalidSymbolError {
4515
4516 public BadConstructorReferenceError(Symbol sym) {
4517 super(MISSING_ENCL, sym, "BadConstructorReferenceError");
4518 }
4519
4520 @Override
4521 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4522 return diags.create(dkind, log.currentSource(), pos,
4523 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType());
4524 }
4525 }
4526
4527 class BadClassFileError extends InvalidSymbolError {
4528
4529 private final CompletionFailure ex;
4530
4531 public BadClassFileError(CompletionFailure ex) {
4532 super(HIDDEN, ex.sym, "BadClassFileError");
4533 this.name = sym.name;
4534 this.ex = ex;
4535 }
4536
4537 @Override
4538 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4539 JCDiagnostic d = diags.create(dkind, log.currentSource(), pos,
4540 "cant.access", ex.sym, ex.getDetailValue());
4541
4542 d.setFlag(DiagnosticFlag.NON_DEFERRABLE);
4543 return d;
4544 }
4545
4546 }
4547
4548 /**
4549 * Helper class for method resolution diagnostic simplification.
4550 * Certain resolution diagnostic are rewritten as simpler diagnostic
4551 * where the enclosing resolution diagnostic (i.e. 'inapplicable method')
4552 * is stripped away, as it doesn't carry additional info. The logic
4553 * for matching a given diagnostic is given in terms of a template
4554 * hierarchy: a diagnostic template can be specified programmatically,
4555 * so that only certain diagnostics are matched. Each templete is then
4556 * associated with a rewriter object that carries out the task of rewtiting
4557 * the diagnostic to a simpler one.
4558 */
4559 static class MethodResolutionDiagHelper {
4560
4561 /**
4562 * A diagnostic rewriter transforms a method resolution diagnostic
4563 * into a simpler one
4564 */
4565 interface DiagnosticRewriter {
4566 JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
4567 DiagnosticPosition preferedPos, DiagnosticSource preferredSource,
4568 DiagnosticType preferredKind, JCDiagnostic d);
4569 }
4570
4571 /**
4572 * A diagnostic template is made up of two ingredients: (i) a regular
4573 * expression for matching a diagnostic key and (ii) a list of sub-templates
4574 * for matching diagnostic arguments.
4575 */
4576 static class Template {
4577
4578 /** regex used to match diag key */
4579 String regex;
4580
4581 /** templates used to match diagnostic args */
4582 Template[] subTemplates;
4583
4584 Template(String key, Template... subTemplates) {
4585 this.regex = key;
4586 this.subTemplates = subTemplates;
4587 }
4588
4589 /**
4590 * Returns true if the regex matches the diagnostic key and if
4591 * all diagnostic arguments are matches by corresponding sub-templates.
4592 */
4593 boolean matches(Object o) {
4594 JCDiagnostic d = (JCDiagnostic)o;
4595 Object[] args = d.getArgs();
4596 if (!d.getCode().matches(regex) ||
4597 subTemplates.length != d.getArgs().length) {
4598 return false;
4599 }
4600 for (int i = 0; i < args.length ; i++) {
4601 if (!subTemplates[i].matches(args[i])) {
4602 return false;
4603 }
4604 }
4605 return true;
4606 }
4607 }
4608
4609 /**
4610 * Common rewriter for all argument mismatch simplifications.
4611 */
4612 static class ArgMismatchRewriter implements DiagnosticRewriter {
4613
4614 /** the index of the subdiagnostic to be used as primary. */
4615 int causeIndex;
4616
4617 public ArgMismatchRewriter(int causeIndex) {
4618 this.causeIndex = causeIndex;
4619 }
4620
4621 @Override
4622 public JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
4623 DiagnosticPosition preferedPos, DiagnosticSource preferredSource,
4624 DiagnosticType preferredKind, JCDiagnostic d) {
4625 JCDiagnostic cause = (JCDiagnostic)d.getArgs()[causeIndex];
4626 DiagnosticPosition pos = d.getDiagnosticPosition();
4627 if (pos == null) {
4628 pos = preferedPos;
4629 }
4630 return diags.create(preferredKind, preferredSource, pos,
4631 "prob.found.req", cause);
4632 }
4633 }
4634
4635 /** a dummy template that match any diagnostic argument */
4636 static final Template skip = new Template("") {
4637 @Override
4638 boolean matches(Object d) {
4639 return true;
4640 }
4641 };
4642
4643 /** template for matching inference-free arguments mismatch failures */
4644 static final Template argMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip);
4645
4646 /** template for matching inference related arguments mismatch failures */
4647 static final Template inferArgMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip, skip) {
4648 @Override
4649 boolean matches(Object o) {
4650 if (!super.matches(o)) {
4651 return false;
4652 }
4653 JCDiagnostic d = (JCDiagnostic)o;
4654 @SuppressWarnings("unchecked")
4655 List<Type> tvars = (List<Type>)d.getArgs()[0];
4656 return !containsAny(d, tvars);
4657 }
4658
4659 BiPredicate<Object, List<Type>> containsPredicate = (o, ts) -> {
4660 if (o instanceof Type) {
4661 return ((Type)o).containsAny(ts);
4662 } else if (o instanceof JCDiagnostic) {
4663 return containsAny((JCDiagnostic)o, ts);
4664 } else {
4665 return false;
4666 }
4667 };
4668
4669 boolean containsAny(JCDiagnostic d, List<Type> ts) {
4670 return Stream.of(d.getArgs())
4671 .anyMatch(o -> containsPredicate.test(o, ts));
4672 }
4673 };
4674
4675 /** rewriter map used for method resolution simplification */
4676 static final Map<Template, DiagnosticRewriter> rewriters = new LinkedHashMap<>();
4677
4678 static {
4679 rewriters.put(argMismatchTemplate, new ArgMismatchRewriter(0));
4680 rewriters.put(inferArgMismatchTemplate, new ArgMismatchRewriter(1));
4681 }
4682
4683 /**
4684 * Main entry point for diagnostic rewriting - given a diagnostic, see if any templates matches it,
4685 * and rewrite it accordingly.
4686 */
4687 static JCDiagnostic rewrite(JCDiagnostic.Factory diags, DiagnosticPosition pos, DiagnosticSource source,
4688 DiagnosticType dkind, JCDiagnostic d) {
4689 for (Map.Entry<Template, DiagnosticRewriter> _entry : rewriters.entrySet()) {
4690 if (_entry.getKey().matches(d)) {
4691 JCDiagnostic simpleDiag =
4692 _entry.getValue().rewriteDiagnostic(diags, pos, source, dkind, d);
4693 simpleDiag.setFlag(DiagnosticFlag.COMPRESSED);
4694 return simpleDiag;
4695 }
4696 }
4697 return null;
4698 }
4699 }
4700
4701 enum MethodResolutionPhase {
4702 BASIC(false, false),
4703 BOX(true, false),
4704 VARARITY(true, true) {
4705 @Override
4706 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) {
4707 //Check invariants (see {@code LookupHelper.shouldStop})
4708 Assert.check(bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS);
4709 if (!sym.kind.isResolutionError()) {
4710 //varargs resolution successful
4711 return sym;
4712 } else {
4713 //pick best error
4714 switch (bestSoFar.kind) {
4715 case WRONG_MTH:
4716 case WRONG_MTHS:
4717 //Override previous errors if they were caused by argument mismatch.
4718 //This generally means preferring current symbols - but we need to pay
4719 //attention to the fact that the varargs lookup returns 'less' candidates
4720 //than the previous rounds, and adjust that accordingly.
4721 switch (sym.kind) {
4722 case WRONG_MTH:
4723 //if the previous round matched more than one method, return that
4724 //result instead
4725 return bestSoFar.kind == WRONG_MTHS ?
4726 bestSoFar : sym;
4727 case ABSENT_MTH:
4728 //do not override erroneous symbol if the arity lookup did not
4729 //match any method
4730 return bestSoFar;
4731 case WRONG_MTHS:
4732 default:
4733 //safe to override
4734 return sym;
4735 }
4736 default:
4737 //otherwise, return first error
4738 return bestSoFar;
4739 }
4740 }
4741 }
4742 };
4743
4744 final boolean isBoxingRequired;
4745 final boolean isVarargsRequired;
4746
4747 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
4748 this.isBoxingRequired = isBoxingRequired;
4749 this.isVarargsRequired = isVarargsRequired;
4750 }
4751
4752 public boolean isBoxingRequired() {
4753 return isBoxingRequired;
4754 }
4755
4756 public boolean isVarargsRequired() {
4757 return isVarargsRequired;
4758 }
4759
4760 public Symbol mergeResults(Symbol prev, Symbol sym) {
4761 return sym;
4762 }
4763 }
4764
4765 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
4766
4767 /**
4768 * A resolution context is used to keep track of intermediate results of
4769 * overload resolution, such as list of method that are not applicable
4770 * (used to generate more precise diagnostics) and so on. Resolution contexts
4771 * can be nested - this means that when each overload resolution routine should
4772 * work within the resolution context it created.
4773 */
4774 class MethodResolutionContext {
4775
4776 private List<Candidate> candidates = List.nil();
4777
4778 MethodResolutionPhase step = null;
4779
4780 MethodCheck methodCheck = resolveMethodCheck;
4781
4782 private boolean internalResolution = false;
4783 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE;
4784
4785 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) {
4786 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null);
4787 candidates = candidates.append(c);
4788 }
4789
4790 void addApplicableCandidate(Symbol sym, Type mtype) {
4791 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype);
4792 candidates = candidates.append(c);
4793 }
4794
4795 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext, ResultInfo pendingResult, Warner warn) {
4796 DeferredAttrContext parent = (pendingResult == null)
4797 ? deferredAttr.emptyDeferredAttrContext
4798 : pendingResult.checkContext.deferredAttrContext();
4799 return deferredAttr.new DeferredAttrContext(attrMode, sym, step,
4800 inferenceContext, parent, warn);
4801 }
4802
4803 /**
4804 * This class represents an overload resolution candidate. There are two
4805 * kinds of candidates: applicable methods and inapplicable methods;
4806 * applicable methods have a pointer to the instantiated method type,
4807 * while inapplicable candidates contain further details about the
4808 * reason why the method has been considered inapplicable.
4809 */
4810 @SuppressWarnings("overrides")
4811 class Candidate {
4812
4813 final MethodResolutionPhase step;
4814 final Symbol sym;
4815 final JCDiagnostic details;
4816 final Type mtype;
4817
4818 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) {
4819 this.step = step;
4820 this.sym = sym;
4821 this.details = details;
4822 this.mtype = mtype;
4823 }
4824
4825 boolean isApplicable() {
4826 return mtype != null;
4827 }
4828 }
4829
4830 DeferredAttr.AttrMode attrMode() {
4831 return attrMode;
4832 }
4833
4834 boolean internal() {
4835 return internalResolution;
4836 }
4837 }
4838
4839 MethodResolutionContext currentResolutionContext = null;
4840 }