1 /*
2 * Copyright (c) 1999, 2021, 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.resources.CompilerProperties.Warnings;
47 import com.sun.tools.javac.tree.*;
48 import com.sun.tools.javac.tree.JCTree.*;
49 import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind;
50 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
51 import com.sun.tools.javac.util.*;
52 import com.sun.tools.javac.util.DefinedBy.Api;
53 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
54 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
55 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
56 import com.sun.tools.javac.util.JCDiagnostic.Warning;
57
58 import java.util.Arrays;
59 import java.util.Collection;
60 import java.util.EnumSet;
61 import java.util.HashSet;
62 import java.util.Iterator;
63 import java.util.LinkedHashMap;
64 import java.util.Map;
65 import java.util.Set;
66 import java.util.function.BiFunction;
67 import java.util.function.BiPredicate;
68 import java.util.function.Consumer;
69 import java.util.function.Function;
70 import java.util.function.Predicate;
71 import java.util.stream.Stream;
72 import java.util.stream.StreamSupport;
73
74 import javax.lang.model.element.ElementVisitor;
75
76 import static com.sun.tools.javac.code.Flags.*;
77 import static com.sun.tools.javac.code.Flags.BLOCK;
78 import static com.sun.tools.javac.code.Flags.STATIC;
79 import static com.sun.tools.javac.code.Kinds.*;
80 import static com.sun.tools.javac.code.Kinds.Kind.*;
81 import static com.sun.tools.javac.code.TypeTag.*;
82 import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*;
83 import static com.sun.tools.javac.tree.JCTree.Tag.*;
84 import static com.sun.tools.javac.util.Iterators.createCompoundIterator;
85
86 /** Helper class for name resolution, used mostly by the attribution phase.
87 *
88 * <p><b>This is NOT part of any supported API.
89 * If you write code that depends on this, you do so at your own risk.
90 * This code and its internal interfaces are subject to change or
91 * deletion without notice.</b>
92 */
93 public class Resolve {
94 protected static final Context.Key<Resolve> resolveKey = new Context.Key<>();
95
96 Names names;
97 Log log;
98 Symtab syms;
99 Attr attr;
100 AttrRecover attrRecover;
101 DeferredAttr deferredAttr;
102 Check chk;
103 Infer infer;
104 ClassFinder finder;
105 ModuleFinder moduleFinder;
106 Types types;
107 JCDiagnostic.Factory diags;
108 public final boolean allowFunctionalInterfaceMostSpecific;
109 public final boolean allowModules;
110 public final boolean allowRecords;
111 public final boolean checkVarargsAccessAfterResolution;
112 private final boolean compactMethodDiags;
113 private final boolean allowLocalVariableTypeInference;
114 private final boolean allowYieldStatement;
115 final EnumSet<VerboseResolutionMode> verboseResolutionMode;
116 final boolean dumpMethodReferenceSearchResults;
117
118 WriteableScope polymorphicSignatureScope;
119
120 protected Resolve(Context context) {
121 context.put(resolveKey, this);
122 syms = Symtab.instance(context);
123
124 varNotFound = new SymbolNotFoundError(ABSENT_VAR);
125 methodNotFound = new SymbolNotFoundError(ABSENT_MTH);
126 typeNotFound = new SymbolNotFoundError(ABSENT_TYP);
127 referenceNotFound = ReferenceLookupResult.error(methodNotFound);
128
129 names = Names.instance(context);
130 log = Log.instance(context);
131 attr = Attr.instance(context);
132 attrRecover = AttrRecover.instance(context);
133 deferredAttr = DeferredAttr.instance(context);
134 chk = Check.instance(context);
135 infer = Infer.instance(context);
136 finder = ClassFinder.instance(context);
137 moduleFinder = ModuleFinder.instance(context);
138 types = Types.instance(context);
139 diags = JCDiagnostic.Factory.instance(context);
140 Preview preview = Preview.instance(context);
141 Source source = Source.instance(context);
142 Options options = Options.instance(context);
143 compactMethodDiags = options.isSet(Option.XDIAGS, "compact") ||
144 options.isUnset(Option.XDIAGS) && options.isUnset("rawDiagnostics");
145 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
146 Target target = Target.instance(context);
147 allowFunctionalInterfaceMostSpecific = Feature.FUNCTIONAL_INTERFACE_MOST_SPECIFIC.allowedInSource(source);
148 allowLocalVariableTypeInference = Feature.LOCAL_VARIABLE_TYPE_INFERENCE.allowedInSource(source);
149 allowYieldStatement = Feature.SWITCH_EXPRESSION.allowedInSource(source);
150 checkVarargsAccessAfterResolution =
151 Feature.POST_APPLICABILITY_VARARGS_ACCESS_CHECK.allowedInSource(source);
152 polymorphicSignatureScope = WriteableScope.create(syms.noSymbol);
153 allowModules = Feature.MODULES.allowedInSource(source);
154 allowRecords = Feature.RECORDS.allowedInSource(source);
155 dumpMethodReferenceSearchResults = options.isSet("debug.dumpMethodReferenceSearchResults");
156 }
157
158 /** error symbols, which are returned when resolution fails
159 */
160 private final SymbolNotFoundError varNotFound;
161 private final SymbolNotFoundError methodNotFound;
162 private final SymbolNotFoundError typeNotFound;
163
164 /** empty reference lookup result */
165 private final ReferenceLookupResult referenceNotFound;
166
167 public static Resolve instance(Context context) {
168 Resolve instance = context.get(resolveKey);
169 if (instance == null)
170 instance = new Resolve(context);
171 return instance;
172 }
173
174 private static Symbol bestOf(Symbol s1,
175 Symbol s2) {
176 return s1.kind.betterThan(s2.kind) ? s1 : s2;
177 }
178
179 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support">
180 enum VerboseResolutionMode {
181 SUCCESS("success"),
182 FAILURE("failure"),
183 APPLICABLE("applicable"),
184 INAPPLICABLE("inapplicable"),
185 DEFERRED_INST("deferred-inference"),
186 PREDEF("predef"),
187 OBJECT_INIT("object-init"),
188 INTERNAL("internal");
189
190 final String opt;
191
192 private VerboseResolutionMode(String opt) {
193 this.opt = opt;
194 }
195
196 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) {
197 String s = opts.get("debug.verboseResolution");
198 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class);
199 if (s == null) return res;
200 if (s.contains("all")) {
201 res = EnumSet.allOf(VerboseResolutionMode.class);
202 }
203 Collection<String> args = Arrays.asList(s.split(","));
204 for (VerboseResolutionMode mode : values()) {
205 if (args.contains(mode.opt)) {
206 res.add(mode);
207 } else if (args.contains("-" + mode.opt)) {
208 res.remove(mode);
209 }
210 }
211 return res;
212 }
213 }
214
215 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site,
216 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) {
217 boolean success = !bestSoFar.kind.isResolutionError();
218
219 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) {
220 return;
221 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) {
222 return;
223 }
224
225 if (bestSoFar.name == names.init &&
226 bestSoFar.owner == syms.objectType.tsym &&
227 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) {
228 return; //skip diags for Object constructor resolution
229 } else if (site == syms.predefClass.type &&
230 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) {
231 return; //skip spurious diags for predef symbols (i.e. operators)
232 } else if (currentResolutionContext.internalResolution &&
233 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) {
234 return;
235 }
236
237 int pos = 0;
238 int mostSpecificPos = -1;
239 ListBuffer<JCDiagnostic> subDiags = new ListBuffer<>();
240 for (Candidate c : currentResolutionContext.candidates) {
241 if (currentResolutionContext.step != c.step ||
242 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) ||
243 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) {
244 continue;
245 } else {
246 subDiags.append(c.isApplicable() ?
247 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) :
248 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details));
249 if (c.sym == bestSoFar)
250 mostSpecificPos = pos;
251 pos++;
252 }
253 }
254 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1";
255 List<Type> argtypes2 = argtypes.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step));
256 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name,
257 site.tsym, mostSpecificPos, currentResolutionContext.step,
258 methodArguments(argtypes2),
259 methodArguments(typeargtypes));
260 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
261 log.report(d);
262 }
263
264 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) {
265 JCDiagnostic subDiag = null;
266 if (sym.type.hasTag(FORALL)) {
267 subDiag = diags.fragment(Fragments.PartialInstSig(inst));
268 }
269
270 String key = subDiag == null ?
271 "applicable.method.found" :
272 "applicable.method.found.1";
273
274 return diags.fragment(key, pos, sym, subDiag);
275 }
276
277 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) {
278 return diags.fragment(Fragments.NotApplicableMethodFound(pos, sym, subDiag));
279 }
280 // </editor-fold>
281
282 /* ************************************************************************
283 * Identifier resolution
284 *************************************************************************/
285
286 /** An environment is "static" if its static level is greater than
287 * the one of its outer environment
288 */
289 protected static boolean isStatic(Env<AttrContext> env) {
290 return env.outer != null && env.info.staticLevel > env.outer.info.staticLevel;
291 }
292
293 /** An environment is an "initializer" if it is a constructor or
294 * an instance initializer.
295 */
296 static boolean isInitializer(Env<AttrContext> env) {
297 Symbol owner = env.info.scope.owner;
298 return owner.isConstructor() ||
299 owner.owner.kind == TYP &&
300 (owner.kind == VAR ||
301 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
302 (owner.flags() & STATIC) == 0;
303 }
304
305 /** Is class accessible in given environment?
306 * @param env The current environment.
307 * @param c The class whose accessibility is checked.
308 */
309 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
310 return isAccessible(env, c, false);
311 }
312
313 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) {
314
315 /* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor
316 to refer to an inaccessible type
317 */
318 if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0)
319 return true;
320
321 if (env.info.visitingServiceImplementation &&
322 env.toplevel.modle == c.packge().modle) {
323 return true;
324 }
325
326 boolean isAccessible = false;
327 switch ((short)(c.flags() & AccessFlags)) {
328 case PRIVATE:
329 isAccessible =
330 env.enclClass.sym.outermostClass() ==
331 c.owner.outermostClass();
332 break;
333 case 0:
334 isAccessible =
335 env.toplevel.packge == c.owner // fast special case
336 ||
337 env.toplevel.packge == c.packge();
338 break;
339 default: // error recovery
340 isAccessible = true;
341 break;
342 case PUBLIC:
343 if (allowModules) {
344 ModuleSymbol currModule = env.toplevel.modle;
345 currModule.complete();
346 PackageSymbol p = c.packge();
347 isAccessible =
348 currModule == p.modle ||
349 currModule.visiblePackages.get(p.fullname) == p ||
350 p == syms.rootPackage ||
351 (p.modle == syms.unnamedModule && currModule.readModules.contains(p.modle));
352 } else {
353 isAccessible = true;
354 }
355 break;
356 case PROTECTED:
357 isAccessible =
358 env.toplevel.packge == c.owner // fast special case
359 ||
360 env.toplevel.packge == c.packge()
361 ||
362 isInnerSubClass(env.enclClass.sym, c.owner);
363 break;
364 }
365 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
366 isAccessible :
367 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
368 }
369 //where
370 /** Is given class a subclass of given base class, or an inner class
371 * of a subclass?
372 * Return null if no such class exists.
373 * @param c The class which is the subclass or is contained in it.
374 * @param base The base class
375 */
376 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
377 while (c != null && !c.isSubClass(base, types)) {
378 c = c.owner.enclClass();
379 }
380 return c != null;
381 }
382
383 boolean isAccessible(Env<AttrContext> env, Type t) {
384 return isAccessible(env, t, false);
385 }
386
387 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) {
388 if (t.hasTag(ARRAY)) {
389 return isAccessible(env, types.cvarUpperBound(types.elemtype(t)));
390 } else if (t.isUnion()) {
391 return StreamSupport.stream(((UnionClassType) t).getAlternativeTypes().spliterator(), false)
392 .allMatch(alternative -> isAccessible(env, alternative.tsym, checkInner));
393 } else {
394 return isAccessible(env, t.tsym, checkInner);
395 }
396 }
397
398 /** Is symbol accessible as a member of given type in given environment?
399 * @param env The current environment.
400 * @param site The type of which the tested symbol is regarded
401 * as a member.
402 * @param sym The symbol.
403 */
404 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
405 return isAccessible(env, site, sym, false);
406 }
407 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) {
408 if (sym.name == names.init && sym.owner != site.tsym) return false;
409
410 /* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor
411 to refer to an inaccessible type
412 */
413 if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0)
414 return true;
415
416 if (env.info.visitingServiceImplementation &&
417 env.toplevel.modle == sym.packge().modle) {
418 return true;
419 }
420
421 switch ((short)(sym.flags() & AccessFlags)) {
422 case PRIVATE:
423 return
424 (env.enclClass.sym == sym.owner // fast special case
425 ||
426 env.enclClass.sym.outermostClass() ==
427 sym.owner.outermostClass())
428 &&
429 sym.isInheritedIn(site.tsym, types);
430 case 0:
431 return
432 (env.toplevel.packge == sym.owner.owner // fast special case
433 ||
434 env.toplevel.packge == sym.packge())
435 &&
436 isAccessible(env, site, checkInner)
437 &&
438 sym.isInheritedIn(site.tsym, types)
439 &&
440 notOverriddenIn(site, sym);
441 case PROTECTED:
442 return
443 (env.toplevel.packge == sym.owner.owner // fast special case
444 ||
445 env.toplevel.packge == sym.packge()
446 ||
447 isProtectedAccessible(sym, env.enclClass.sym, site)
448 ||
449 // OK to select instance method or field from 'super' or type name
450 // (but type names should be disallowed elsewhere!)
451 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
452 &&
453 isAccessible(env, site, checkInner)
454 &&
455 notOverriddenIn(site, sym);
456 default: // this case includes erroneous combinations as well
457 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
458 }
459 }
460 //where
461 /* `sym' is accessible only if not overridden by
462 * another symbol which is a member of `site'
463 * (because, if it is overridden, `sym' is not strictly
464 * speaking a member of `site'). A polymorphic signature method
465 * cannot be overridden (e.g. MH.invokeExact(Object[])).
466 */
467 private boolean notOverriddenIn(Type site, Symbol sym) {
468 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
469 return true;
470 else {
471 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
472 return (s2 == null || s2 == sym || sym.owner == s2.owner || (sym.owner.isInterface() && s2.owner == syms.objectType.tsym) ||
473 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
474 }
475 }
476 //where
477 /** Is given protected symbol accessible if it is selected from given site
478 * and the selection takes place in given class?
479 * @param sym The symbol with protected access
480 * @param c The class where the access takes place
481 * @site The type of the qualifier
482 */
483 private
484 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
485 Type newSite = site.hasTag(TYPEVAR) ? site.getUpperBound() : site;
486 while (c != null &&
487 !(c.isSubClass(sym.owner, types) &&
488 (c.flags() & INTERFACE) == 0 &&
489 // In JLS 2e 6.6.2.1, the subclass restriction applies
490 // only to instance fields and methods -- types are excluded
491 // regardless of whether they are declared 'static' or not.
492 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || newSite.tsym.isSubClass(c, types))))
493 c = c.owner.enclClass();
494 return c != null;
495 }
496
497 /**
498 * Performs a recursive scan of a type looking for accessibility problems
499 * from current attribution environment
500 */
501 void checkAccessibleType(Env<AttrContext> env, Type t) {
502 accessibilityChecker.visit(t, env);
503 }
504
505 /**
506 * Accessibility type-visitor
507 */
508 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker =
509 new Types.SimpleVisitor<Void, Env<AttrContext>>() {
510
511 void visit(List<Type> ts, Env<AttrContext> env) {
512 for (Type t : ts) {
513 visit(t, env);
514 }
515 }
516
517 public Void visitType(Type t, Env<AttrContext> env) {
518 return null;
519 }
520
521 @Override
522 public Void visitArrayType(ArrayType t, Env<AttrContext> env) {
523 visit(t.elemtype, env);
524 return null;
525 }
526
527 @Override
528 public Void visitClassType(ClassType t, Env<AttrContext> env) {
529 visit(t.getTypeArguments(), env);
530 if (!isAccessible(env, t, true)) {
531 accessBase(new AccessError(env, null, t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true);
532 }
533 return null;
534 }
535
536 @Override
537 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) {
538 visit(t.type, env);
539 return null;
540 }
541
542 @Override
543 public Void visitMethodType(MethodType t, Env<AttrContext> env) {
544 visit(t.getParameterTypes(), env);
545 visit(t.getReturnType(), env);
546 visit(t.getThrownTypes(), env);
547 return null;
548 }
549 };
550
551 /** Try to instantiate the type of a method so that it fits
552 * given type arguments and argument types. If successful, return
553 * the method's instantiated type, else return null.
554 * The instantiation will take into account an additional leading
555 * formal parameter if the method is an instance method seen as a member
556 * of an under determined site. In this case, we treat site as an additional
557 * parameter and the parameters of the class containing the method as
558 * additional type variables that get instantiated.
559 *
560 * @param env The current environment
561 * @param site The type of which the method is a member.
562 * @param m The method symbol.
563 * @param argtypes The invocation's given value arguments.
564 * @param typeargtypes The invocation's given type arguments.
565 * @param allowBoxing Allow boxing conversions of arguments.
566 * @param useVarargs Box trailing arguments into an array for varargs.
567 */
568 Type rawInstantiate(Env<AttrContext> env,
569 Type site,
570 Symbol m,
571 ResultInfo resultInfo,
572 List<Type> argtypes,
573 List<Type> typeargtypes,
574 boolean allowBoxing,
575 boolean useVarargs,
576 Warner warn) throws Infer.InferenceException {
577 Type mt = types.memberType(site, m);
578 // tvars is the list of formal type variables for which type arguments
579 // need to inferred.
580 List<Type> tvars = List.nil();
581 if (typeargtypes == null) typeargtypes = List.nil();
582 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
583 // This is not a polymorphic method, but typeargs are supplied
584 // which is fine, see JLS 15.12.2.1
585 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
586 ForAll pmt = (ForAll) mt;
587 if (typeargtypes.length() != pmt.tvars.length())
588 // not enough args
589 throw new InapplicableMethodException(diags.fragment(Fragments.WrongNumberTypeArgs(Integer.toString(pmt.tvars.length()))));
590 // Check type arguments are within bounds
591 List<Type> formals = pmt.tvars;
592 List<Type> actuals = typeargtypes;
593 while (formals.nonEmpty() && actuals.nonEmpty()) {
594 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
595 pmt.tvars, typeargtypes);
596 for (; bounds.nonEmpty(); bounds = bounds.tail) {
597 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn)) {
598 throw new InapplicableMethodException(diags.fragment(Fragments.ExplicitParamDoNotConformToBounds(actuals.head, bounds)));
599 }
600 }
601 formals = formals.tail;
602 actuals = actuals.tail;
603 }
604 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
605 } else if (mt.hasTag(FORALL)) {
606 ForAll pmt = (ForAll) mt;
607 List<Type> tvars1 = types.newInstances(pmt.tvars);
608 tvars = tvars.appendList(tvars1);
609 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
610 }
611
612 // find out whether we need to go the slow route via infer
613 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/
614 for (List<Type> l = argtypes;
615 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
616 l = l.tail) {
617 if (l.head.hasTag(FORALL)) instNeeded = true;
618 }
619
620 if (instNeeded) {
621 return infer.instantiateMethod(env,
622 tvars,
623 (MethodType)mt,
624 resultInfo,
625 (MethodSymbol)m,
626 argtypes,
627 allowBoxing,
628 useVarargs,
629 currentResolutionContext,
630 warn);
631 }
632
633 DeferredAttr.DeferredAttrContext dc = currentResolutionContext.deferredAttrContext(m, infer.emptyContext, resultInfo, warn);
634 currentResolutionContext.methodCheck.argumentsAcceptable(env, dc,
635 argtypes, mt.getParameterTypes(), warn);
636 dc.complete();
637 return mt;
638 }
639
640 Type checkMethod(Env<AttrContext> env,
641 Type site,
642 Symbol m,
643 ResultInfo resultInfo,
644 List<Type> argtypes,
645 List<Type> typeargtypes,
646 Warner warn) {
647 MethodResolutionContext prevContext = currentResolutionContext;
648 try {
649 currentResolutionContext = new MethodResolutionContext();
650 currentResolutionContext.attrMode = (resultInfo.pt == Infer.anyPoly) ?
651 AttrMode.SPECULATIVE : DeferredAttr.AttrMode.CHECK;
652 if (env.tree.hasTag(JCTree.Tag.REFERENCE)) {
653 //method/constructor references need special check class
654 //to handle inference variables in 'argtypes' (might happen
655 //during an unsticking round)
656 currentResolutionContext.methodCheck =
657 new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
658 }
659 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase;
660 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
661 step.isBoxingRequired(), step.isVarargsRequired(), warn);
662 }
663 finally {
664 currentResolutionContext = prevContext;
665 }
666 }
667
668 /** Same but returns null instead throwing a NoInstanceException
669 */
670 Type instantiate(Env<AttrContext> env,
671 Type site,
672 Symbol m,
673 ResultInfo resultInfo,
674 List<Type> argtypes,
675 List<Type> typeargtypes,
676 boolean allowBoxing,
677 boolean useVarargs,
678 Warner warn) {
679 try {
680 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
681 allowBoxing, useVarargs, warn);
682 } catch (InapplicableMethodException ex) {
683 return null;
684 }
685 }
686
687 /**
688 * This interface defines an entry point that should be used to perform a
689 * method check. A method check usually consist in determining as to whether
690 * a set of types (actuals) is compatible with another set of types (formals).
691 * Since the notion of compatibility can vary depending on the circumstances,
692 * this interfaces allows to easily add new pluggable method check routines.
693 */
694 interface MethodCheck {
695 /**
696 * Main method check routine. A method check usually consist in determining
697 * as to whether a set of types (actuals) is compatible with another set of
698 * types (formals). If an incompatibility is found, an unchecked exception
699 * is assumed to be thrown.
700 */
701 void argumentsAcceptable(Env<AttrContext> env,
702 DeferredAttrContext deferredAttrContext,
703 List<Type> argtypes,
704 List<Type> formals,
705 Warner warn);
706
707 /**
708 * Retrieve the method check object that will be used during a
709 * most specific check.
710 */
711 MethodCheck mostSpecificCheck(List<Type> actuals);
712 }
713
714 /**
715 * Helper enum defining all method check diagnostics (used by resolveMethodCheck).
716 */
717 enum MethodCheckDiag {
718 /**
719 * Actuals and formals differs in length.
720 */
721 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"),
722 /**
723 * An actual is incompatible with a formal.
724 */
725 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"),
726 /**
727 * An actual is incompatible with the varargs element type.
728 */
729 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"),
730 /**
731 * The varargs element type is inaccessible.
732 */
733 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type");
734
735 final String basicKey;
736 final String inferKey;
737
738 MethodCheckDiag(String basicKey, String inferKey) {
739 this.basicKey = basicKey;
740 this.inferKey = inferKey;
741 }
742
743 String regex() {
744 return String.format("([a-z]*\\.)*(%s|%s)", basicKey, inferKey);
745 }
746 }
747
748 /**
749 * Dummy method check object. All methods are deemed applicable, regardless
750 * of their formal parameter types.
751 */
752 MethodCheck nilMethodCheck = new MethodCheck() {
753 public void argumentsAcceptable(Env<AttrContext> env, DeferredAttrContext deferredAttrContext, List<Type> argtypes, List<Type> formals, Warner warn) {
754 //do nothing - method always applicable regardless of actuals
755 }
756
757 public MethodCheck mostSpecificCheck(List<Type> actuals) {
758 return this;
759 }
760 };
761
762 /**
763 * Base class for 'real' method checks. The class defines the logic for
764 * iterating through formals and actuals and provides and entry point
765 * that can be used by subclasses in order to define the actual check logic.
766 */
767 abstract class AbstractMethodCheck implements MethodCheck {
768 @Override
769 public void argumentsAcceptable(final Env<AttrContext> env,
770 DeferredAttrContext deferredAttrContext,
771 List<Type> argtypes,
772 List<Type> formals,
773 Warner warn) {
774 //should we expand formals?
775 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired();
776 JCTree callTree = treeForDiagnostics(env);
777 List<JCExpression> trees = TreeInfo.args(callTree);
778
779 //inference context used during this method check
780 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
781
782 Type varargsFormal = useVarargs ? formals.last() : null;
783
784 if (varargsFormal == null &&
785 argtypes.size() != formals.size()) {
786 reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
787 }
788
789 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
790 DiagnosticPosition pos = trees != null ? trees.head : null;
791 checkArg(pos, false, argtypes.head, formals.head, deferredAttrContext, warn);
792 argtypes = argtypes.tail;
793 formals = formals.tail;
794 trees = trees != null ? trees.tail : trees;
795 }
796
797 if (formals.head != varargsFormal) {
798 reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
799 }
800
801 if (useVarargs) {
802 //note: if applicability check is triggered by most specific test,
803 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
804 final Type elt = types.elemtype(varargsFormal);
805 while (argtypes.nonEmpty()) {
806 DiagnosticPosition pos = trees != null ? trees.head : null;
807 checkArg(pos, true, argtypes.head, elt, deferredAttrContext, warn);
808 argtypes = argtypes.tail;
809 trees = trees != null ? trees.tail : trees;
810 }
811 }
812 }
813
814 // where
815 private JCTree treeForDiagnostics(Env<AttrContext> env) {
816 return env.info.preferredTreeForDiagnostics != null ? env.info.preferredTreeForDiagnostics : env.tree;
817 }
818
819 /**
820 * Does the actual argument conforms to the corresponding formal?
821 */
822 abstract void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn);
823
824 protected void reportMC(DiagnosticPosition pos, MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
825 boolean inferDiag = inferenceContext != infer.emptyContext;
826 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) {
827 Object[] args2 = new Object[args.length + 1];
828 System.arraycopy(args, 0, args2, 1, args.length);
829 args2[0] = inferenceContext.inferenceVars();
830 args = args2;
831 }
832 String key = inferDiag ? diag.inferKey : diag.basicKey;
833 throw inferDiag ?
834 infer.error(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args)) :
835 methodCheckFailure.setMessage(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args));
836 }
837
838 /**
839 * To eliminate the overhead associated with allocating an exception object in such an
840 * hot execution path, we use flyweight pattern - and share the same exception instance
841 * across multiple method check failures.
842 */
843 class SharedInapplicableMethodException extends InapplicableMethodException {
844 private static final long serialVersionUID = 0;
845
846 SharedInapplicableMethodException() {
847 super(null);
848 }
849
850 SharedInapplicableMethodException setMessage(JCDiagnostic details) {
851 this.diagnostic = details;
852 return this;
853 }
854 }
855
856 SharedInapplicableMethodException methodCheckFailure = new SharedInapplicableMethodException();
857
858 public MethodCheck mostSpecificCheck(List<Type> actuals) {
859 return nilMethodCheck;
860 }
861
862 }
863
864 /**
865 * Arity-based method check. A method is applicable if the number of actuals
866 * supplied conforms to the method signature.
867 */
868 MethodCheck arityMethodCheck = new AbstractMethodCheck() {
869 @Override
870 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
871 //do nothing - actual always compatible to formals
872 }
873
874 @Override
875 public String toString() {
876 return "arityMethodCheck";
877 }
878 };
879
880 /**
881 * Main method applicability routine. Given a list of actual types A,
882 * a list of formal types F, determines whether the types in A are
883 * compatible (by method invocation conversion) with the types in F.
884 *
885 * Since this routine is shared between overload resolution and method
886 * type-inference, a (possibly empty) inference context is used to convert
887 * formal types to the corresponding 'undet' form ahead of a compatibility
888 * check so that constraints can be propagated and collected.
889 *
890 * Moreover, if one or more types in A is a deferred type, this routine uses
891 * DeferredAttr in order to perform deferred attribution. If one or more actual
892 * deferred types are stuck, they are placed in a queue and revisited later
893 * after the remainder of the arguments have been seen. If this is not sufficient
894 * to 'unstuck' the argument, a cyclic inference error is called out.
895 *
896 * A method check handler (see above) is used in order to report errors.
897 */
898 MethodCheck resolveMethodCheck = new AbstractMethodCheck() {
899
900 @Override
901 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
902 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
903 mresult.check(pos, actual);
904 }
905
906 @Override
907 public void argumentsAcceptable(final Env<AttrContext> env,
908 DeferredAttrContext deferredAttrContext,
909 List<Type> argtypes,
910 List<Type> formals,
911 Warner warn) {
912 super.argumentsAcceptable(env, deferredAttrContext, argtypes, formals, warn);
913 // should we check varargs element type accessibility?
914 if (deferredAttrContext.phase.isVarargsRequired()) {
915 if (deferredAttrContext.mode == AttrMode.CHECK || !checkVarargsAccessAfterResolution) {
916 varargsAccessible(env, types.elemtype(formals.last()), deferredAttrContext.inferenceContext);
917 }
918 }
919 }
920
921 /**
922 * Test that the runtime array element type corresponding to 't' is accessible. 't' should be the
923 * varargs element type of either the method invocation type signature (after inference completes)
924 * or the method declaration signature (before inference completes).
925 */
926 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) {
927 if (inferenceContext.free(t)) {
928 inferenceContext.addFreeTypeListener(List.of(t),
929 solvedContext -> varargsAccessible(env, solvedContext.asInstType(t), solvedContext));
930 } else {
931 if (!isAccessible(env, types.erasure(t))) {
932 Symbol location = env.enclClass.sym;
933 reportMC(env.tree, MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
934 }
935 }
936 }
937
938 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
939 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
940 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
941 MethodCheckDiag methodDiag = varargsCheck ?
942 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
943
944 @Override
945 public void report(DiagnosticPosition pos, JCDiagnostic details) {
946 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
947 }
948 };
949 return new MethodResultInfo(to, checkContext);
950 }
951
952 @Override
953 public MethodCheck mostSpecificCheck(List<Type> actuals) {
954 return new MostSpecificCheck(actuals);
955 }
956
957 @Override
958 public String toString() {
959 return "resolveMethodCheck";
960 }
961 };
962
963 /**
964 * This class handles method reference applicability checks; since during
965 * these checks it's sometime possible to have inference variables on
966 * the actual argument types list, the method applicability check must be
967 * extended so that inference variables are 'opened' as needed.
968 */
969 class MethodReferenceCheck extends AbstractMethodCheck {
970
971 InferenceContext pendingInferenceContext;
972
973 MethodReferenceCheck(InferenceContext pendingInferenceContext) {
974 this.pendingInferenceContext = pendingInferenceContext;
975 }
976
977 @Override
978 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
979 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
980 mresult.check(pos, actual);
981 }
982
983 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
984 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
985 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
986 MethodCheckDiag methodDiag = varargsCheck ?
987 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
988
989 @Override
990 public boolean compatible(Type found, Type req, Warner warn) {
991 found = pendingInferenceContext.asUndetVar(found);
992 if (found.hasTag(UNDETVAR) && req.isPrimitive()) {
993 req = types.boxedClass(req).type;
994 }
995 return super.compatible(found, req, warn);
996 }
997
998 @Override
999 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1000 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
1001 }
1002 };
1003 return new MethodResultInfo(to, checkContext);
1004 }
1005
1006 @Override
1007 public MethodCheck mostSpecificCheck(List<Type> actuals) {
1008 return new MostSpecificCheck(actuals);
1009 }
1010
1011 @Override
1012 public String toString() {
1013 return "MethodReferenceCheck";
1014 }
1015 }
1016
1017 /**
1018 * Check context to be used during method applicability checks. A method check
1019 * context might contain inference variables.
1020 */
1021 abstract class MethodCheckContext implements CheckContext {
1022
1023 boolean strict;
1024 DeferredAttrContext deferredAttrContext;
1025 Warner rsWarner;
1026
1027 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) {
1028 this.strict = strict;
1029 this.deferredAttrContext = deferredAttrContext;
1030 this.rsWarner = rsWarner;
1031 }
1032
1033 public boolean compatible(Type found, Type req, Warner warn) {
1034 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
1035 return strict ?
1036 types.isSubtypeUnchecked(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn) :
1037 types.isConvertible(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn);
1038 }
1039
1040 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1041 throw new InapplicableMethodException(details);
1042 }
1043
1044 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
1045 return rsWarner;
1046 }
1047
1048 public InferenceContext inferenceContext() {
1049 return deferredAttrContext.inferenceContext;
1050 }
1051
1052 public DeferredAttrContext deferredAttrContext() {
1053 return deferredAttrContext;
1054 }
1055
1056 @Override
1057 public String toString() {
1058 return "MethodCheckContext";
1059 }
1060 }
1061
1062 /**
1063 * ResultInfo class to be used during method applicability checks. Check
1064 * for deferred types goes through special path.
1065 */
1066 class MethodResultInfo extends ResultInfo {
1067
1068 public MethodResultInfo(Type pt, CheckContext checkContext) {
1069 attr.super(KindSelector.VAL, pt, checkContext);
1070 }
1071
1072 @Override
1073 protected Type check(DiagnosticPosition pos, Type found) {
1074 if (found.hasTag(DEFERRED)) {
1075 DeferredType dt = (DeferredType)found;
1076 return dt.check(this);
1077 } else {
1078 Type uResult = U(found);
1079 Type capturedType = pos == null || pos.getTree() == null ?
1080 types.capture(uResult) :
1081 checkContext.inferenceContext()
1082 .cachedCapture(pos.getTree(), uResult, true);
1083 return super.check(pos, chk.checkNonVoid(pos, capturedType));
1084 }
1085 }
1086
1087 /**
1088 * javac has a long-standing 'simplification' (see 6391995):
1089 * given an actual argument type, the method check is performed
1090 * on its upper bound. This leads to inconsistencies when an
1091 * argument type is checked against itself. For example, given
1092 * a type-variable T, it is not true that {@code U(T) <: T},
1093 * so we need to guard against that.
1094 */
1095 private Type U(Type found) {
1096 return found == pt ?
1097 found : types.cvarUpperBound(found);
1098 }
1099
1100 @Override
1101 protected MethodResultInfo dup(Type newPt) {
1102 return new MethodResultInfo(newPt, checkContext);
1103 }
1104
1105 @Override
1106 protected ResultInfo dup(CheckContext newContext) {
1107 return new MethodResultInfo(pt, newContext);
1108 }
1109
1110 @Override
1111 protected ResultInfo dup(Type newPt, CheckContext newContext) {
1112 return new MethodResultInfo(newPt, newContext);
1113 }
1114 }
1115
1116 /**
1117 * Most specific method applicability routine. Given a list of actual types A,
1118 * a list of formal types F1, and a list of formal types F2, the routine determines
1119 * as to whether the types in F1 can be considered more specific than those in F2 w.r.t.
1120 * argument types A.
1121 */
1122 class MostSpecificCheck implements MethodCheck {
1123
1124 List<Type> actuals;
1125
1126 MostSpecificCheck(List<Type> actuals) {
1127 this.actuals = actuals;
1128 }
1129
1130 @Override
1131 public void argumentsAcceptable(final Env<AttrContext> env,
1132 DeferredAttrContext deferredAttrContext,
1133 List<Type> formals1,
1134 List<Type> formals2,
1135 Warner warn) {
1136 formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired());
1137 while (formals2.nonEmpty()) {
1138 ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head);
1139 mresult.check(null, formals1.head);
1140 formals1 = formals1.tail;
1141 formals2 = formals2.tail;
1142 actuals = actuals.isEmpty() ? actuals : actuals.tail;
1143 }
1144 }
1145
1146 /**
1147 * Create a method check context to be used during the most specific applicability check
1148 */
1149 ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext,
1150 Warner rsWarner, Type actual) {
1151 return attr.new ResultInfo(KindSelector.VAL, to,
1152 new MostSpecificCheckContext(deferredAttrContext, rsWarner, actual));
1153 }
1154
1155 /**
1156 * Subclass of method check context class that implements most specific
1157 * method conversion. If the actual type under analysis is a deferred type
1158 * a full blown structural analysis is carried out.
1159 */
1160 class MostSpecificCheckContext extends MethodCheckContext {
1161
1162 Type actual;
1163
1164 public MostSpecificCheckContext(DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) {
1165 super(true, deferredAttrContext, rsWarner);
1166 this.actual = actual;
1167 }
1168
1169 public boolean compatible(Type found, Type req, Warner warn) {
1170 if (allowFunctionalInterfaceMostSpecific &&
1171 unrelatedFunctionalInterfaces(found, req) &&
1172 (actual != null && actual.getTag() == DEFERRED)) {
1173 DeferredType dt = (DeferredType) actual;
1174 JCTree speculativeTree = dt.speculativeTree(deferredAttrContext);
1175 if (speculativeTree != deferredAttr.stuckTree) {
1176 return functionalInterfaceMostSpecific(found, req, speculativeTree);
1177 }
1178 }
1179 return compatibleBySubtyping(found, req);
1180 }
1181
1182 private boolean compatibleBySubtyping(Type found, Type req) {
1183 if (!strict && found.isPrimitive() != req.isPrimitive()) {
1184 found = found.isPrimitive() ? types.boxedClass(found).type : types.unboxedType(found);
1185 }
1186 return types.isSubtypeNoCapture(found, deferredAttrContext.inferenceContext.asUndetVar(req));
1187 }
1188
1189 /** Whether {@code t} and {@code s} are unrelated functional interface types. */
1190 private boolean unrelatedFunctionalInterfaces(Type t, Type s) {
1191 return types.isFunctionalInterface(t.tsym) &&
1192 types.isFunctionalInterface(s.tsym) &&
1193 unrelatedInterfaces(t, s);
1194 }
1195
1196 /** Whether {@code t} and {@code s} are unrelated interface types; recurs on intersections. **/
1197 private boolean unrelatedInterfaces(Type t, Type s) {
1198 if (t.isCompound()) {
1199 for (Type ti : types.interfaces(t)) {
1200 if (!unrelatedInterfaces(ti, s)) {
1201 return false;
1202 }
1203 }
1204 return true;
1205 } else if (s.isCompound()) {
1206 for (Type si : types.interfaces(s)) {
1207 if (!unrelatedInterfaces(t, si)) {
1208 return false;
1209 }
1210 }
1211 return true;
1212 } else {
1213 return types.asSuper(t, s.tsym) == null && types.asSuper(s, t.tsym) == null;
1214 }
1215 }
1216
1217 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */
1218 private boolean functionalInterfaceMostSpecific(Type t, Type s, JCTree tree) {
1219 Type tDesc = types.findDescriptorType(types.capture(t));
1220 Type tDescNoCapture = types.findDescriptorType(t);
1221 Type sDesc = types.findDescriptorType(s);
1222 final List<Type> tTypeParams = tDesc.getTypeArguments();
1223 final List<Type> tTypeParamsNoCapture = tDescNoCapture.getTypeArguments();
1224 final List<Type> sTypeParams = sDesc.getTypeArguments();
1225
1226 // compare type parameters
1227 if (tDesc.hasTag(FORALL) && !types.hasSameBounds((ForAll) tDesc, (ForAll) tDescNoCapture)) {
1228 return false;
1229 }
1230 // can't use Types.hasSameBounds on sDesc because bounds may have ivars
1231 List<Type> tIter = tTypeParams;
1232 List<Type> sIter = sTypeParams;
1233 while (tIter.nonEmpty() && sIter.nonEmpty()) {
1234 Type tBound = tIter.head.getUpperBound();
1235 Type sBound = types.subst(sIter.head.getUpperBound(), sTypeParams, tTypeParams);
1236 if (tBound.containsAny(tTypeParams) && inferenceContext().free(sBound)) {
1237 return false;
1238 }
1239 if (!types.isSameType(tBound, inferenceContext().asUndetVar(sBound))) {
1240 return false;
1241 }
1242 tIter = tIter.tail;
1243 sIter = sIter.tail;
1244 }
1245 if (!tIter.isEmpty() || !sIter.isEmpty()) {
1246 return false;
1247 }
1248
1249 // compare parameters
1250 List<Type> tParams = tDesc.getParameterTypes();
1251 List<Type> tParamsNoCapture = tDescNoCapture.getParameterTypes();
1252 List<Type> sParams = sDesc.getParameterTypes();
1253 while (tParams.nonEmpty() && tParamsNoCapture.nonEmpty() && sParams.nonEmpty()) {
1254 Type tParam = tParams.head;
1255 Type tParamNoCapture = types.subst(tParamsNoCapture.head, tTypeParamsNoCapture, tTypeParams);
1256 Type sParam = types.subst(sParams.head, sTypeParams, tTypeParams);
1257 if (tParam.containsAny(tTypeParams) && inferenceContext().free(sParam)) {
1258 return false;
1259 }
1260 if (!types.isSubtype(inferenceContext().asUndetVar(sParam), tParam)) {
1261 return false;
1262 }
1263 if (!types.isSameType(tParamNoCapture, inferenceContext().asUndetVar(sParam))) {
1264 return false;
1265 }
1266 tParams = tParams.tail;
1267 tParamsNoCapture = tParamsNoCapture.tail;
1268 sParams = sParams.tail;
1269 }
1270 if (!tParams.isEmpty() || !tParamsNoCapture.isEmpty() || !sParams.isEmpty()) {
1271 return false;
1272 }
1273
1274 // compare returns
1275 Type tRet = tDesc.getReturnType();
1276 Type sRet = types.subst(sDesc.getReturnType(), sTypeParams, tTypeParams);
1277 if (tRet.containsAny(tTypeParams) && inferenceContext().free(sRet)) {
1278 return false;
1279 }
1280 MostSpecificFunctionReturnChecker msc = new MostSpecificFunctionReturnChecker(tRet, sRet);
1281 msc.scan(tree);
1282 return msc.result;
1283 }
1284
1285 /**
1286 * Tests whether one functional interface type can be considered more specific
1287 * than another unrelated functional interface type for the scanned expression.
1288 */
1289 class MostSpecificFunctionReturnChecker extends DeferredAttr.PolyScanner {
1290
1291 final Type tRet;
1292 final Type sRet;
1293 boolean result;
1294
1295 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */
1296 MostSpecificFunctionReturnChecker(Type tRet, Type sRet) {
1297 this.tRet = tRet;
1298 this.sRet = sRet;
1299 result = true;
1300 }
1301
1302 @Override
1303 void skip(JCTree tree) {
1304 result = false;
1305 }
1306
1307 @Override
1308 public void visitConditional(JCConditional tree) {
1309 scan(asExpr(tree.truepart));
1310 scan(asExpr(tree.falsepart));
1311 }
1312
1313 @Override
1314 public void visitReference(JCMemberReference tree) {
1315 if (sRet.hasTag(VOID)) {
1316 // do nothing
1317 } else if (tRet.hasTag(VOID)) {
1318 result = false;
1319 } else if (tRet.isPrimitive() != sRet.isPrimitive()) {
1320 boolean retValIsPrimitive =
1321 tree.refPolyKind == PolyKind.STANDALONE &&
1322 tree.sym.type.getReturnType().isPrimitive();
1323 result &= (retValIsPrimitive == tRet.isPrimitive()) &&
1324 (retValIsPrimitive != sRet.isPrimitive());
1325 } else {
1326 result &= compatibleBySubtyping(tRet, sRet);
1327 }
1328 }
1329
1330 @Override
1331 public void visitParens(JCParens tree) {
1332 scan(asExpr(tree.expr));
1333 }
1334
1335 @Override
1336 public void visitLambda(JCLambda tree) {
1337 if (sRet.hasTag(VOID)) {
1338 // do nothing
1339 } else if (tRet.hasTag(VOID)) {
1340 result = false;
1341 } else {
1342 List<JCExpression> lambdaResults = lambdaResults(tree);
1343 if (!lambdaResults.isEmpty() && unrelatedFunctionalInterfaces(tRet, sRet)) {
1344 for (JCExpression expr : lambdaResults) {
1345 result &= functionalInterfaceMostSpecific(tRet, sRet, expr);
1346 }
1347 } else if (!lambdaResults.isEmpty() && tRet.isPrimitive() != sRet.isPrimitive()) {
1348 for (JCExpression expr : lambdaResults) {
1349 boolean retValIsPrimitive = expr.isStandalone() && expr.type.isPrimitive();
1350 result &= (retValIsPrimitive == tRet.isPrimitive()) &&
1351 (retValIsPrimitive != sRet.isPrimitive());
1352 }
1353 } else {
1354 result &= compatibleBySubtyping(tRet, sRet);
1355 }
1356 }
1357 }
1358 //where
1359
1360 private List<JCExpression> lambdaResults(JCLambda lambda) {
1361 if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) {
1362 return List.of(asExpr((JCExpression) lambda.body));
1363 } else {
1364 final ListBuffer<JCExpression> buffer = new ListBuffer<>();
1365 DeferredAttr.LambdaReturnScanner lambdaScanner =
1366 new DeferredAttr.LambdaReturnScanner() {
1367 @Override
1368 public void visitReturn(JCReturn tree) {
1369 if (tree.expr != null) {
1370 buffer.append(asExpr(tree.expr));
1371 }
1372 }
1373 };
1374 lambdaScanner.scan(lambda.body);
1375 return buffer.toList();
1376 }
1377 }
1378
1379 private JCExpression asExpr(JCExpression expr) {
1380 if (expr.type.hasTag(DEFERRED)) {
1381 JCTree speculativeTree = ((DeferredType)expr.type).speculativeTree(deferredAttrContext);
1382 if (speculativeTree != deferredAttr.stuckTree) {
1383 expr = (JCExpression)speculativeTree;
1384 }
1385 }
1386 return expr;
1387 }
1388 }
1389
1390 }
1391
1392 public MethodCheck mostSpecificCheck(List<Type> actuals) {
1393 Assert.error("Cannot get here!");
1394 return null;
1395 }
1396 }
1397
1398 public static class InapplicableMethodException extends RuntimeException {
1399 private static final long serialVersionUID = 0;
1400
1401 transient JCDiagnostic diagnostic;
1402
1403 InapplicableMethodException(JCDiagnostic diag) {
1404 this.diagnostic = diag;
1405 }
1406
1407 public JCDiagnostic getDiagnostic() {
1408 return diagnostic;
1409 }
1410 }
1411
1412 /* ***************************************************************************
1413 * Symbol lookup
1414 * the following naming conventions for arguments are used
1415 *
1416 * env is the environment where the symbol was mentioned
1417 * site is the type of which the symbol is a member
1418 * name is the symbol's name
1419 * if no arguments are given
1420 * argtypes are the value arguments, if we search for a method
1421 *
1422 * If no symbol was found, a ResolveError detailing the problem is returned.
1423 ****************************************************************************/
1424
1425 /** Find field. Synthetic fields are always skipped.
1426 * @param env The current environment.
1427 * @param site The original type from where the selection takes place.
1428 * @param name The name of the field.
1429 * @param c The class to search for the field. This is always
1430 * a superclass or implemented interface of site's class.
1431 */
1432 Symbol findField(Env<AttrContext> env,
1433 Type site,
1434 Name name,
1435 TypeSymbol c) {
1436 while (c.type.hasTag(TYPEVAR))
1437 c = c.type.getUpperBound().tsym;
1438 Symbol bestSoFar = varNotFound;
1439 Symbol sym;
1440 for (Symbol s : c.members().getSymbolsByName(name)) {
1441 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) {
1442 return isAccessible(env, site, s)
1443 ? s : new AccessError(env, site, s);
1444 }
1445 }
1446 Type st = types.supertype(c.type);
1447 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) {
1448 sym = findField(env, site, name, st.tsym);
1449 bestSoFar = bestOf(bestSoFar, sym);
1450 }
1451 for (List<Type> l = types.interfaces(c.type);
1452 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1453 l = l.tail) {
1454 sym = findField(env, site, name, l.head.tsym);
1455 if (bestSoFar.exists() && sym.exists() &&
1456 sym.owner != bestSoFar.owner)
1457 bestSoFar = new AmbiguityError(bestSoFar, sym);
1458 else
1459 bestSoFar = bestOf(bestSoFar, sym);
1460 }
1461 return bestSoFar;
1462 }
1463
1464 /** Resolve a field identifier, throw a fatal error if not found.
1465 * @param pos The position to use for error reporting.
1466 * @param env The environment current at the method invocation.
1467 * @param site The type of the qualifying expression, in which
1468 * identifier is searched.
1469 * @param name The identifier's name.
1470 */
1471 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
1472 Type site, Name name) {
1473 Symbol sym = findField(env, site, name, site.tsym);
1474 if (sym.kind == VAR) return (VarSymbol)sym;
1475 else throw new FatalError(
1476 diags.fragment(Fragments.FatalErrCantLocateField(name)));
1477 }
1478
1479 /** Find unqualified variable or field with given name.
1480 * Synthetic fields always skipped.
1481 * @param env The current environment.
1482 * @param name The name of the variable or field.
1483 */
1484 Symbol findVar(Env<AttrContext> env, Name name) {
1485 Symbol bestSoFar = varNotFound;
1486 Env<AttrContext> env1 = env;
1487 boolean staticOnly = false;
1488 while (env1.outer != null) {
1489 Symbol sym = null;
1490 for (Symbol s : env1.info.scope.getSymbolsByName(name)) {
1491 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) {
1492 sym = s;
1493 if (staticOnly) {
1494 return new StaticError(sym);
1495 }
1496 break;
1497 }
1498 }
1499 if (isStatic(env1)) staticOnly = true;
1500 if (sym == null) {
1501 sym = findField(env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
1502 }
1503 if (sym.exists()) {
1504 if (staticOnly &&
1505 sym.kind == VAR &&
1506 sym.owner.kind == TYP &&
1507 (sym.flags() & STATIC) == 0)
1508 return new StaticError(sym);
1509 else
1510 return sym;
1511 } else {
1512 bestSoFar = bestOf(bestSoFar, sym);
1513 }
1514
1515 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1516 env1 = env1.outer;
1517 }
1518
1519 Symbol sym = findField(env, syms.predefClass.type, name, syms.predefClass);
1520 if (sym.exists())
1521 return sym;
1522 if (bestSoFar.exists())
1523 return bestSoFar;
1524
1525 Symbol origin = null;
1526 for (Scope sc : new Scope[] { env.toplevel.namedImportScope, env.toplevel.starImportScope }) {
1527 for (Symbol currentSymbol : sc.getSymbolsByName(name)) {
1528 if (currentSymbol.kind != VAR)
1529 continue;
1530 // invariant: sym.kind == Symbol.Kind.VAR
1531 if (!bestSoFar.kind.isResolutionError() &&
1532 currentSymbol.owner != bestSoFar.owner)
1533 return new AmbiguityError(bestSoFar, currentSymbol);
1534 else if (!bestSoFar.kind.betterThan(VAR)) {
1535 origin = sc.getOrigin(currentSymbol).owner;
1536 bestSoFar = isAccessible(env, origin.type, currentSymbol)
1537 ? currentSymbol : new AccessError(env, origin.type, currentSymbol);
1538 }
1539 }
1540 if (bestSoFar.exists()) break;
1541 }
1542 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
1543 return bestSoFar.clone(origin);
1544 else
1545 return bestSoFar;
1546 }
1547
1548 Warner noteWarner = new Warner();
1549
1550 /** Select the best method for a call site among two choices.
1551 * @param env The current environment.
1552 * @param site The original type from where the
1553 * selection takes place.
1554 * @param argtypes The invocation's value arguments,
1555 * @param typeargtypes The invocation's type arguments,
1556 * @param sym Proposed new best match.
1557 * @param bestSoFar Previously found best match.
1558 * @param allowBoxing Allow boxing conversions of arguments.
1559 * @param useVarargs Box trailing arguments into an array for varargs.
1560 */
1561 @SuppressWarnings("fallthrough")
1562 Symbol selectBest(Env<AttrContext> env,
1563 Type site,
1564 List<Type> argtypes,
1565 List<Type> typeargtypes,
1566 Symbol sym,
1567 Symbol bestSoFar,
1568 boolean allowBoxing,
1569 boolean useVarargs) {
1570 if (sym.kind == ERR ||
1571 (site.tsym != sym.owner && !sym.isInheritedIn(site.tsym, types)) ||
1572 !notOverriddenIn(site, sym)) {
1573 return bestSoFar;
1574 } else if (useVarargs && (sym.flags() & VARARGS) == 0) {
1575 return bestSoFar.kind.isResolutionError() ?
1576 new BadVarargsMethod((ResolveError)bestSoFar.baseSymbol()) :
1577 bestSoFar;
1578 }
1579 Assert.check(!sym.kind.isResolutionError());
1580 try {
1581 types.noWarnings.clear();
1582 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes,
1583 allowBoxing, useVarargs, types.noWarnings);
1584 currentResolutionContext.addApplicableCandidate(sym, mt);
1585 } catch (InapplicableMethodException ex) {
1586 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic());
1587 // Currently, an InapplicableMethodException occurs.
1588 // If bestSoFar.kind was ABSENT_MTH, return an InapplicableSymbolError(kind is WRONG_MTH).
1589 // If bestSoFar.kind was HIDDEN(AccessError)/WRONG_MTH/WRONG_MTHS, return an InapplicableSymbolsError(kind is WRONG_MTHS).
1590 // See JDK-8255968 for more information.
1591 switch (bestSoFar.kind) {
1592 case ABSENT_MTH:
1593 return new InapplicableSymbolError(currentResolutionContext);
1594 case HIDDEN:
1595 if (bestSoFar instanceof AccessError accessError) {
1596 // Add the JCDiagnostic of previous AccessError to the currentResolutionContext
1597 // and construct InapplicableSymbolsError.
1598 // Intentionally fallthrough.
1599 currentResolutionContext.addInapplicableCandidate(accessError.sym,
1600 accessError.getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT, null, null, site, null, argtypes, typeargtypes));
1601 } else {
1602 return bestSoFar;
1603 }
1604 case WRONG_MTH:
1605 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1606 default:
1607 return bestSoFar;
1608 }
1609 }
1610 if (!isAccessible(env, site, sym)) {
1611 AccessError curAccessError = new AccessError(env, site, sym);
1612 JCDiagnostic curDiagnostic = curAccessError.getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT, null, null, site, null, argtypes, typeargtypes);
1613 // Currently, an AccessError occurs.
1614 // If bestSoFar.kind was ABSENT_MTH, return an AccessError(kind is HIDDEN).
1615 // If bestSoFar.kind was HIDDEN(AccessError), WRONG_MTH, WRONG_MTHS, return an InapplicableSymbolsError(kind is WRONG_MTHS).
1616 // See JDK-8255968 for more information.
1617 if (bestSoFar.kind == ABSENT_MTH) {
1618 bestSoFar = curAccessError;
1619 } else if (bestSoFar.kind == WRONG_MTH) {
1620 // Add the JCDiagnostic of current AccessError to the currentResolutionContext
1621 // and construct InapplicableSymbolsError.
1622 currentResolutionContext.addInapplicableCandidate(sym, curDiagnostic);
1623 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1624 } else if (bestSoFar.kind == WRONG_MTHS) {
1625 // Add the JCDiagnostic of current AccessError to the currentResolutionContext
1626 currentResolutionContext.addInapplicableCandidate(sym, curDiagnostic);
1627 } else if (bestSoFar.kind == HIDDEN && bestSoFar instanceof AccessError accessError) {
1628 // Add the JCDiagnostics of previous and current AccessError to the currentResolutionContext
1629 // and construct InapplicableSymbolsError.
1630 currentResolutionContext.addInapplicableCandidate(accessError.sym,
1631 accessError.getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT, null, null, site, null, argtypes, typeargtypes));
1632 currentResolutionContext.addInapplicableCandidate(sym, curDiagnostic);
1633 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1634 }
1635 return bestSoFar;
1636 }
1637 return (bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS)
1638 ? sym
1639 : mostSpecific(argtypes, sym, bestSoFar, env, site, useVarargs);
1640 }
1641
1642 /* Return the most specific of the two methods for a call,
1643 * given that both are accessible and applicable.
1644 * @param m1 A new candidate for most specific.
1645 * @param m2 The previous most specific candidate.
1646 * @param env The current environment.
1647 * @param site The original type from where the selection
1648 * takes place.
1649 * @param allowBoxing Allow boxing conversions of arguments.
1650 * @param useVarargs Box trailing arguments into an array for varargs.
1651 */
1652 Symbol mostSpecific(List<Type> argtypes, Symbol m1,
1653 Symbol m2,
1654 Env<AttrContext> env,
1655 final Type site,
1656 boolean useVarargs) {
1657 switch (m2.kind) {
1658 case MTH:
1659 if (m1 == m2) return m1;
1660 boolean m1SignatureMoreSpecific =
1661 signatureMoreSpecific(argtypes, env, site, m1, m2, useVarargs);
1662 boolean m2SignatureMoreSpecific =
1663 signatureMoreSpecific(argtypes, env, site, m2, m1, useVarargs);
1664 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
1665 Type mt1 = types.memberType(site, m1);
1666 Type mt2 = types.memberType(site, m2);
1667 if (!types.overrideEquivalent(mt1, mt2))
1668 return ambiguityError(m1, m2);
1669
1670 // same signature; select (a) the non-bridge method, or
1671 // (b) the one that overrides the other, or (c) the concrete
1672 // one, or (d) merge both abstract signatures
1673 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
1674 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
1675
1676 if (m1.baseSymbol() == m2.baseSymbol()) {
1677 // this is the same imported symbol which has been cloned twice.
1678 // Return the first one (either will do).
1679 return m1;
1680 }
1681
1682 // if one overrides or hides the other, use it
1683 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
1684 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
1685 // the two owners can never be the same if the target methods are compiled from source,
1686 // but we need to protect against cases where the methods are defined in some classfile
1687 // and make sure we issue an ambiguity error accordingly (by skipping the logic below).
1688 if (m1Owner != m2Owner) {
1689 if (types.asSuper(m1Owner.type, m2Owner) != null &&
1690 ((m1.owner.flags_field & INTERFACE) == 0 ||
1691 (m2.owner.flags_field & INTERFACE) != 0) &&
1692 m1.overrides(m2, m1Owner, types, false))
1693 return m1;
1694 if (types.asSuper(m2Owner.type, m1Owner) != null &&
1695 ((m2.owner.flags_field & INTERFACE) == 0 ||
1696 (m1.owner.flags_field & INTERFACE) != 0) &&
1697 m2.overrides(m1, m2Owner, types, false))
1698 return m2;
1699 }
1700 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
1701 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
1702 if (m1Abstract && !m2Abstract) return m2;
1703 if (m2Abstract && !m1Abstract) return m1;
1704 // both abstract or both concrete
1705 return ambiguityError(m1, m2);
1706 }
1707 if (m1SignatureMoreSpecific) return m1;
1708 if (m2SignatureMoreSpecific) return m2;
1709 return ambiguityError(m1, m2);
1710 case AMBIGUOUS:
1711 //compare m1 to ambiguous methods in m2
1712 AmbiguityError e = (AmbiguityError)m2.baseSymbol();
1713 boolean m1MoreSpecificThanAnyAmbiguous = true;
1714 boolean allAmbiguousMoreSpecificThanM1 = true;
1715 for (Symbol s : e.ambiguousSyms) {
1716 Symbol moreSpecific = mostSpecific(argtypes, m1, s, env, site, useVarargs);
1717 m1MoreSpecificThanAnyAmbiguous &= moreSpecific == m1;
1718 allAmbiguousMoreSpecificThanM1 &= moreSpecific == s;
1719 }
1720 if (m1MoreSpecificThanAnyAmbiguous)
1721 return m1;
1722 //if m1 is more specific than some ambiguous methods, but other ambiguous methods are
1723 //more specific than m1, add it as a new ambiguous method:
1724 if (!allAmbiguousMoreSpecificThanM1)
1725 e.addAmbiguousSymbol(m1);
1726 return e;
1727 default:
1728 throw new AssertionError();
1729 }
1730 }
1731 //where
1732 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean useVarargs) {
1733 noteWarner.clear();
1734 int maxLength = Math.max(
1735 Math.max(m1.type.getParameterTypes().length(), actuals.length()),
1736 m2.type.getParameterTypes().length());
1737 MethodResolutionContext prevResolutionContext = currentResolutionContext;
1738 try {
1739 currentResolutionContext = new MethodResolutionContext();
1740 currentResolutionContext.step = prevResolutionContext.step;
1741 currentResolutionContext.methodCheck =
1742 prevResolutionContext.methodCheck.mostSpecificCheck(actuals);
1743 Type mst = instantiate(env, site, m2, null,
1744 adjustArgs(types.cvarLowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null,
1745 false, useVarargs, noteWarner);
1746 return mst != null &&
1747 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
1748 } finally {
1749 currentResolutionContext = prevResolutionContext;
1750 }
1751 }
1752
1753 List<Type> adjustArgs(List<Type> args, Symbol msym, int length, boolean allowVarargs) {
1754 if ((msym.flags() & VARARGS) != 0 && allowVarargs) {
1755 Type varargsElem = types.elemtype(args.last());
1756 if (varargsElem == null) {
1757 Assert.error("Bad varargs = " + args.last() + " " + msym);
1758 }
1759 List<Type> newArgs = args.reverse().tail.prepend(varargsElem).reverse();
1760 while (newArgs.length() < length) {
1761 newArgs = newArgs.append(newArgs.last());
1762 }
1763 return newArgs;
1764 } else {
1765 return args;
1766 }
1767 }
1768 //where
1769 Symbol ambiguityError(Symbol m1, Symbol m2) {
1770 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
1771 return (m1.flags() & CLASH) == 0 ? m1 : m2;
1772 } else {
1773 return new AmbiguityError(m1, m2);
1774 }
1775 }
1776
1777 Symbol findMethodInScope(Env<AttrContext> env,
1778 Type site,
1779 Name name,
1780 List<Type> argtypes,
1781 List<Type> typeargtypes,
1782 Scope sc,
1783 Symbol bestSoFar,
1784 boolean allowBoxing,
1785 boolean useVarargs,
1786 boolean abstractok) {
1787 for (Symbol s : sc.getSymbolsByName(name, new LookupFilter(abstractok))) {
1788 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s,
1789 bestSoFar, allowBoxing, useVarargs);
1790 }
1791 return bestSoFar;
1792 }
1793 //where
1794 class LookupFilter implements Predicate<Symbol> {
1795
1796 boolean abstractOk;
1797
1798 LookupFilter(boolean abstractOk) {
1799 this.abstractOk = abstractOk;
1800 }
1801
1802 @Override
1803 public boolean test(Symbol s) {
1804 long flags = s.flags();
1805 return s.kind == MTH &&
1806 (flags & SYNTHETIC) == 0 &&
1807 (abstractOk ||
1808 (flags & DEFAULT) != 0 ||
1809 (flags & ABSTRACT) == 0);
1810 }
1811 }
1812
1813 /** Find best qualified method matching given name, type and value
1814 * arguments.
1815 * @param env The current environment.
1816 * @param site The original type from where the selection
1817 * takes place.
1818 * @param name The method's name.
1819 * @param argtypes The method's value arguments.
1820 * @param typeargtypes The method's type arguments
1821 * @param allowBoxing Allow boxing conversions of arguments.
1822 * @param useVarargs Box trailing arguments into an array for varargs.
1823 */
1824 Symbol findMethod(Env<AttrContext> env,
1825 Type site,
1826 Name name,
1827 List<Type> argtypes,
1828 List<Type> typeargtypes,
1829 boolean allowBoxing,
1830 boolean useVarargs) {
1831 Symbol bestSoFar = methodNotFound;
1832 bestSoFar = findMethod(env,
1833 site,
1834 name,
1835 argtypes,
1836 typeargtypes,
1837 site.tsym.type,
1838 bestSoFar,
1839 allowBoxing,
1840 useVarargs);
1841 return bestSoFar;
1842 }
1843 // where
1844 private Symbol findMethod(Env<AttrContext> env,
1845 Type site,
1846 Name name,
1847 List<Type> argtypes,
1848 List<Type> typeargtypes,
1849 Type intype,
1850 Symbol bestSoFar,
1851 boolean allowBoxing,
1852 boolean useVarargs) {
1853 @SuppressWarnings({"unchecked","rawtypes"})
1854 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() };
1855
1856 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK;
1857 boolean isInterface = site.tsym.isInterface();
1858 for (TypeSymbol s : isInterface ? List.of(intype.tsym) : superclasses(intype)) {
1859 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1860 s.members(), bestSoFar, allowBoxing, useVarargs, true);
1861 if (name == names.init) return bestSoFar;
1862 iphase = (iphase == null) ? null : iphase.update(s, this);
1863 if (iphase != null) {
1864 for (Type itype : types.interfaces(s.type)) {
1865 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]);
1866 }
1867 }
1868 }
1869
1870 Symbol concrete = bestSoFar.kind.isValid() &&
1871 (bestSoFar.flags() & ABSTRACT) == 0 ?
1872 bestSoFar : methodNotFound;
1873
1874 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) {
1875 //keep searching for abstract methods
1876 for (Type itype : itypes[iphase2.ordinal()]) {
1877 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure())
1878 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK &&
1879 (itype.tsym.flags() & DEFAULT) == 0) continue;
1880 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1881 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, true);
1882 if (concrete != bestSoFar &&
1883 concrete.kind.isValid() &&
1884 bestSoFar.kind.isValid() &&
1885 types.isSubSignature(concrete.type, bestSoFar.type)) {
1886 //this is an hack - as javac does not do full membership checks
1887 //most specific ends up comparing abstract methods that might have
1888 //been implemented by some concrete method in a subclass and,
1889 //because of raw override, it is possible for an abstract method
1890 //to be more specific than the concrete method - so we need
1891 //to explicitly call that out (see CR 6178365)
1892 bestSoFar = concrete;
1893 }
1894 }
1895 }
1896 if (isInterface && bestSoFar.kind.isResolutionError()) {
1897 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1898 syms.objectType.tsym.members(), bestSoFar, allowBoxing, useVarargs, true);
1899 if (bestSoFar.kind.isValid()) {
1900 Symbol baseSymbol = bestSoFar;
1901 bestSoFar = new MethodSymbol(bestSoFar.flags_field, bestSoFar.name, bestSoFar.type, intype.tsym) {
1902 @Override
1903 public Symbol baseSymbol() {
1904 return baseSymbol;
1905 }
1906 };
1907 }
1908 }
1909 return bestSoFar;
1910 }
1911
1912 enum InterfaceLookupPhase {
1913 ABSTRACT_OK() {
1914 @Override
1915 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1916 //We should not look for abstract methods if receiver is a concrete class
1917 //(as concrete classes are expected to implement all abstracts coming
1918 //from superinterfaces)
1919 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) {
1920 return this;
1921 } else {
1922 return DEFAULT_OK;
1923 }
1924 }
1925 },
1926 DEFAULT_OK() {
1927 @Override
1928 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1929 return this;
1930 }
1931 };
1932
1933 abstract InterfaceLookupPhase update(Symbol s, Resolve rs);
1934 }
1935
1936 /**
1937 * Return an Iterable object to scan the superclasses of a given type.
1938 * It's crucial that the scan is done lazily, as we don't want to accidentally
1939 * access more supertypes than strictly needed (as this could trigger completion
1940 * errors if some of the not-needed supertypes are missing/ill-formed).
1941 */
1942 Iterable<TypeSymbol> superclasses(final Type intype) {
1943 return () -> new Iterator<TypeSymbol>() {
1944
1945 List<TypeSymbol> seen = List.nil();
1946 TypeSymbol currentSym = symbolFor(intype);
1947 TypeSymbol prevSym = null;
1948
1949 public boolean hasNext() {
1950 if (currentSym == syms.noSymbol) {
1951 currentSym = symbolFor(types.supertype(prevSym.type));
1952 }
1953 return currentSym != null;
1954 }
1955
1956 public TypeSymbol next() {
1957 prevSym = currentSym;
1958 currentSym = syms.noSymbol;
1959 Assert.check(prevSym != null || prevSym != syms.noSymbol);
1960 return prevSym;
1961 }
1962
1963 public void remove() {
1964 throw new UnsupportedOperationException();
1965 }
1966
1967 TypeSymbol symbolFor(Type t) {
1968 if (!t.hasTag(CLASS) &&
1969 !t.hasTag(TYPEVAR)) {
1970 return null;
1971 }
1972 t = types.skipTypeVars(t, false);
1973 if (seen.contains(t.tsym)) {
1974 //degenerate case in which we have a circular
1975 //class hierarchy - because of ill-formed classfiles
1976 return null;
1977 }
1978 seen = seen.prepend(t.tsym);
1979 return t.tsym;
1980 }
1981 };
1982 }
1983
1984 /** Find unqualified method matching given name, type and value arguments.
1985 * @param env The current environment.
1986 * @param name The method's name.
1987 * @param argtypes The method's value arguments.
1988 * @param typeargtypes The method's type arguments.
1989 * @param allowBoxing Allow boxing conversions of arguments.
1990 * @param useVarargs Box trailing arguments into an array for varargs.
1991 */
1992 Symbol findFun(Env<AttrContext> env, Name name,
1993 List<Type> argtypes, List<Type> typeargtypes,
1994 boolean allowBoxing, boolean useVarargs) {
1995 Symbol bestSoFar = methodNotFound;
1996 Env<AttrContext> env1 = env;
1997 boolean staticOnly = false;
1998 while (env1.outer != null) {
1999 if (isStatic(env1)) staticOnly = true;
2000 Assert.check(env1.info.preferredTreeForDiagnostics == null);
2001 env1.info.preferredTreeForDiagnostics = env.tree;
2002 try {
2003 Symbol sym = findMethod(
2004 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
2005 allowBoxing, useVarargs);
2006 if (sym.exists()) {
2007 if (staticOnly &&
2008 sym.kind == MTH &&
2009 sym.owner.kind == TYP &&
2010 (sym.flags() & STATIC) == 0) return new StaticError(sym);
2011 else return sym;
2012 } else {
2013 bestSoFar = bestOf(bestSoFar, sym);
2014 }
2015 } finally {
2016 env1.info.preferredTreeForDiagnostics = null;
2017 }
2018 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
2019 env1 = env1.outer;
2020 }
2021
2022 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
2023 typeargtypes, allowBoxing, useVarargs);
2024 if (sym.exists())
2025 return sym;
2026
2027 for (Symbol currentSym : env.toplevel.namedImportScope.getSymbolsByName(name)) {
2028 Symbol origin = env.toplevel.namedImportScope.getOrigin(currentSym).owner;
2029 if (currentSym.kind == MTH) {
2030 if (currentSym.owner.type != origin.type)
2031 currentSym = currentSym.clone(origin);
2032 if (!isAccessible(env, origin.type, currentSym))
2033 currentSym = new AccessError(env, origin.type, currentSym);
2034 bestSoFar = selectBest(env, origin.type,
2035 argtypes, typeargtypes,
2036 currentSym, bestSoFar,
2037 allowBoxing, useVarargs);
2038 }
2039 }
2040 if (bestSoFar.exists())
2041 return bestSoFar;
2042
2043 for (Symbol currentSym : env.toplevel.starImportScope.getSymbolsByName(name)) {
2044 Symbol origin = env.toplevel.starImportScope.getOrigin(currentSym).owner;
2045 if (currentSym.kind == MTH) {
2046 if (currentSym.owner.type != origin.type)
2047 currentSym = currentSym.clone(origin);
2048 if (!isAccessible(env, origin.type, currentSym))
2049 currentSym = new AccessError(env, origin.type, currentSym);
2050 bestSoFar = selectBest(env, origin.type,
2051 argtypes, typeargtypes,
2052 currentSym, bestSoFar,
2053 allowBoxing, useVarargs);
2054 }
2055 }
2056 return bestSoFar;
2057 }
2058
2059 /** Load toplevel or member class with given fully qualified name and
2060 * verify that it is accessible.
2061 * @param env The current environment.
2062 * @param name The fully qualified name of the class to be loaded.
2063 */
2064 Symbol loadClass(Env<AttrContext> env, Name name, RecoveryLoadClass recoveryLoadClass) {
2065 try {
2066 ClassSymbol c = finder.loadClass(env.toplevel.modle, name);
2067 return isAccessible(env, c) ? c : new AccessError(env, null, c);
2068 } catch (ClassFinder.BadClassFile err) {
2069 return new BadClassFileError(err);
2070 } catch (CompletionFailure ex) {
2071 Symbol candidate = recoveryLoadClass.loadClass(env, name);
2072
2073 if (candidate != null) {
2074 return candidate;
2075 }
2076
2077 return typeNotFound;
2078 }
2079 }
2080
2081 public interface RecoveryLoadClass {
2082 Symbol loadClass(Env<AttrContext> env, Name name);
2083 }
2084
2085 private final RecoveryLoadClass noRecovery = (env, name) -> null;
2086
2087 private final RecoveryLoadClass doRecoveryLoadClass = new RecoveryLoadClass() {
2088 @Override public Symbol loadClass(Env<AttrContext> env, Name name) {
2089 List<Name> candidates = Convert.classCandidates(name);
2090 return lookupInvisibleSymbol(env, name,
2091 n -> () -> createCompoundIterator(candidates,
2092 c -> syms.getClassesForName(c)
2093 .iterator()),
2094 (ms, n) -> {
2095 for (Name candidate : candidates) {
2096 try {
2097 return finder.loadClass(ms, candidate);
2098 } catch (CompletionFailure cf) {
2099 //ignore
2100 }
2101 }
2102 return null;
2103 }, sym -> sym.kind == Kind.TYP, typeNotFound);
2104 }
2105 };
2106
2107 private final RecoveryLoadClass namedImportScopeRecovery = (env, name) -> {
2108 Scope importScope = env.toplevel.namedImportScope;
2109 Symbol existing = importScope.findFirst(Convert.shortName(name),
2110 sym -> sym.kind == TYP && sym.flatName() == name);
2111
2112 if (existing != null) {
2113 return new InvisibleSymbolError(env, true, existing);
2114 }
2115 return null;
2116 };
2117
2118 private final RecoveryLoadClass starImportScopeRecovery = (env, name) -> {
2119 Scope importScope = env.toplevel.starImportScope;
2120 Symbol existing = importScope.findFirst(Convert.shortName(name),
2121 sym -> sym.kind == TYP && sym.flatName() == name);
2122
2123 if (existing != null) {
2124 try {
2125 existing = finder.loadClass(existing.packge().modle, name);
2126
2127 return new InvisibleSymbolError(env, true, existing);
2128 } catch (CompletionFailure cf) {
2129 //ignore
2130 }
2131 }
2132
2133 return null;
2134 };
2135
2136 Symbol lookupPackage(Env<AttrContext> env, Name name) {
2137 PackageSymbol pack = syms.lookupPackage(env.toplevel.modle, name);
2138
2139 if (allowModules && isImportOnDemand(env, name)) {
2140 if (pack.members().isEmpty()) {
2141 return lookupInvisibleSymbol(env, name, syms::getPackagesForName, syms::enterPackage, sym -> {
2142 sym.complete();
2143 return !sym.members().isEmpty();
2144 }, pack);
2145 }
2146 }
2147
2148 return pack;
2149 }
2150
2151 private boolean isImportOnDemand(Env<AttrContext> env, Name name) {
2152 if (!env.tree.hasTag(IMPORT))
2153 return false;
2154
2155 JCTree qualid = ((JCImport) env.tree).qualid;
2156
2157 if (!qualid.hasTag(SELECT))
2158 return false;
2159
2160 if (TreeInfo.name(qualid) != names.asterisk)
2161 return false;
2162
2163 return TreeInfo.fullName(((JCFieldAccess) qualid).selected) == name;
2164 }
2165
2166 private <S extends Symbol> Symbol lookupInvisibleSymbol(Env<AttrContext> env,
2167 Name name,
2168 Function<Name, Iterable<S>> get,
2169 BiFunction<ModuleSymbol, Name, S> load,
2170 Predicate<S> validate,
2171 Symbol defaultResult) {
2172 //even if a class/package cannot be found in the current module and among packages in modules
2173 //it depends on that are exported for any or this module, the class/package may exist internally
2174 //in some of these modules, or may exist in a module on which this module does not depend.
2175 //Provide better diagnostic in such cases by looking for the class in any module:
2176 Iterable<? extends S> candidates = get.apply(name);
2177
2178 for (S sym : candidates) {
2179 if (validate.test(sym))
2180 return createInvisibleSymbolError(env, sym);
2181 }
2182
2183 Set<ModuleSymbol> recoverableModules = new HashSet<>(syms.getAllModules());
2184
2185 recoverableModules.add(syms.unnamedModule);
2186 recoverableModules.remove(env.toplevel.modle);
2187
2188 for (ModuleSymbol ms : recoverableModules) {
2189 //avoid overly eager completing classes from source-based modules, as those
2190 //may not be completable with the current compiler settings:
2191 if (ms.sourceLocation == null) {
2192 if (ms.classLocation == null) {
2193 ms = moduleFinder.findModule(ms);
2194 }
2195
2196 if (ms.kind != ERR) {
2197 S sym = load.apply(ms, name);
2198
2199 if (sym != null && validate.test(sym)) {
2200 return createInvisibleSymbolError(env, sym);
2201 }
2202 }
2203 }
2204 }
2205
2206 return defaultResult;
2207 }
2208
2209 private Symbol createInvisibleSymbolError(Env<AttrContext> env, Symbol sym) {
2210 if (symbolPackageVisible(env, sym)) {
2211 return new AccessError(env, null, sym);
2212 } else {
2213 return new InvisibleSymbolError(env, false, sym);
2214 }
2215 }
2216
2217 private boolean symbolPackageVisible(Env<AttrContext> env, Symbol sym) {
2218 ModuleSymbol envMod = env.toplevel.modle;
2219 PackageSymbol symPack = sym.packge();
2220 return envMod == symPack.modle ||
2221 envMod.visiblePackages.containsKey(symPack.fullname);
2222 }
2223
2224 /**
2225 * Find a type declared in a scope (not inherited). Return null
2226 * if none is found.
2227 * @param env The current environment.
2228 * @param site The original type from where the selection takes
2229 * place.
2230 * @param name The type's name.
2231 * @param c The class to search for the member type. This is
2232 * always a superclass or implemented interface of
2233 * site's class.
2234 */
2235 Symbol findImmediateMemberType(Env<AttrContext> env,
2236 Type site,
2237 Name name,
2238 TypeSymbol c) {
2239 for (Symbol sym : c.members().getSymbolsByName(name)) {
2240 if (sym.kind == TYP) {
2241 return isAccessible(env, site, sym)
2242 ? sym
2243 : new AccessError(env, site, sym);
2244 }
2245 }
2246 return typeNotFound;
2247 }
2248
2249 /** Find a member type inherited from a superclass or interface.
2250 * @param env The current environment.
2251 * @param site The original type from where the selection takes
2252 * place.
2253 * @param name The type's name.
2254 * @param c The class to search for the member type. This is
2255 * always a superclass or implemented interface of
2256 * site's class.
2257 */
2258 Symbol findInheritedMemberType(Env<AttrContext> env,
2259 Type site,
2260 Name name,
2261 TypeSymbol c) {
2262 Symbol bestSoFar = typeNotFound;
2263 Symbol sym;
2264 Type st = types.supertype(c.type);
2265 if (st != null && st.hasTag(CLASS)) {
2266 sym = findMemberType(env, site, name, st.tsym);
2267 bestSoFar = bestOf(bestSoFar, sym);
2268 }
2269 for (List<Type> l = types.interfaces(c.type);
2270 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
2271 l = l.tail) {
2272 sym = findMemberType(env, site, name, l.head.tsym);
2273 if (!bestSoFar.kind.isResolutionError() &&
2274 !sym.kind.isResolutionError() &&
2275 sym.owner != bestSoFar.owner)
2276 bestSoFar = new AmbiguityError(bestSoFar, sym);
2277 else
2278 bestSoFar = bestOf(bestSoFar, sym);
2279 }
2280 return bestSoFar;
2281 }
2282
2283 /** Find qualified member type.
2284 * @param env The current environment.
2285 * @param site The original type from where the selection takes
2286 * place.
2287 * @param name The type's name.
2288 * @param c The class to search for the member type. This is
2289 * always a superclass or implemented interface of
2290 * site's class.
2291 */
2292 Symbol findMemberType(Env<AttrContext> env,
2293 Type site,
2294 Name name,
2295 TypeSymbol c) {
2296 Symbol sym = findImmediateMemberType(env, site, name, c);
2297
2298 if (sym != typeNotFound)
2299 return sym;
2300
2301 return findInheritedMemberType(env, site, name, c);
2302
2303 }
2304
2305 /** Find a global type in given scope and load corresponding class.
2306 * @param env The current environment.
2307 * @param scope The scope in which to look for the type.
2308 * @param name The type's name.
2309 */
2310 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name, RecoveryLoadClass recoveryLoadClass) {
2311 Symbol bestSoFar = typeNotFound;
2312 for (Symbol s : scope.getSymbolsByName(name)) {
2313 Symbol sym = loadClass(env, s.flatName(), recoveryLoadClass);
2314 if (bestSoFar.kind == TYP && sym.kind == TYP &&
2315 bestSoFar != sym)
2316 return new AmbiguityError(bestSoFar, sym);
2317 else
2318 bestSoFar = bestOf(bestSoFar, sym);
2319 }
2320 return bestSoFar;
2321 }
2322
2323 Symbol findTypeVar(Env<AttrContext> env, Name name, boolean staticOnly) {
2324 for (Symbol sym : env.info.scope.getSymbolsByName(name)) {
2325 if (sym.kind == TYP) {
2326 if (sym.type.hasTag(TYPEVAR) &&
2327 (staticOnly || (isStatic(env) && sym.owner.kind == TYP)))
2328 // if staticOnly is set, it means that we have recursed through a static declaration,
2329 // so type variable symbols should not be accessible. If staticOnly is unset, but
2330 // we are in a static declaration (field or method), we should not allow type-variables
2331 // defined in the enclosing class to "leak" into this context.
2332 return new StaticError(sym);
2333 return sym;
2334 }
2335 }
2336 return typeNotFound;
2337 }
2338
2339 /** Find an unqualified type symbol.
2340 * @param env The current environment.
2341 * @param name The type's name.
2342 */
2343 Symbol findType(Env<AttrContext> env, Name name) {
2344 if (name == names.empty)
2345 return typeNotFound; // do not allow inadvertent "lookup" of anonymous types
2346 Symbol bestSoFar = typeNotFound;
2347 Symbol sym;
2348 boolean staticOnly = false;
2349 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
2350 // First, look for a type variable and the first member type
2351 final Symbol tyvar = findTypeVar(env1, name, staticOnly);
2352 if (isStatic(env1)) staticOnly = true;
2353 sym = findImmediateMemberType(env1, env1.enclClass.sym.type,
2354 name, env1.enclClass.sym);
2355
2356 // Return the type variable if we have it, and have no
2357 // immediate member, OR the type variable is for a method.
2358 if (tyvar != typeNotFound) {
2359 if (env.baseClause || sym == typeNotFound ||
2360 (tyvar.kind == TYP && tyvar.exists() &&
2361 tyvar.owner.kind == MTH)) {
2362 return tyvar;
2363 }
2364 }
2365
2366 // If the environment is a class def, finish up,
2367 // otherwise, do the entire findMemberType
2368 if (sym == typeNotFound)
2369 sym = findInheritedMemberType(env1, env1.enclClass.sym.type,
2370 name, env1.enclClass.sym);
2371
2372 if (staticOnly && sym.kind == TYP &&
2373 sym.type.hasTag(CLASS) &&
2374 sym.type.getEnclosingType().hasTag(CLASS) &&
2375 env1.enclClass.sym.type.isParameterized() &&
2376 sym.type.getEnclosingType().isParameterized())
2377 return new StaticError(sym);
2378 else if (sym.exists()) return sym;
2379 else bestSoFar = bestOf(bestSoFar, sym);
2380
2381 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
2382 if ((encl.sym.flags() & STATIC) != 0)
2383 staticOnly = true;
2384 }
2385
2386 if (!env.tree.hasTag(IMPORT)) {
2387 sym = findGlobalType(env, env.toplevel.namedImportScope, name, namedImportScopeRecovery);
2388 if (sym.exists()) return sym;
2389 else bestSoFar = bestOf(bestSoFar, sym);
2390
2391 sym = findGlobalType(env, env.toplevel.toplevelScope, name, noRecovery);
2392 if (sym.exists()) return sym;
2393 else bestSoFar = bestOf(bestSoFar, sym);
2394
2395 sym = findGlobalType(env, env.toplevel.packge.members(), name, noRecovery);
2396 if (sym.exists()) return sym;
2397 else bestSoFar = bestOf(bestSoFar, sym);
2398
2399 sym = findGlobalType(env, env.toplevel.starImportScope, name, starImportScopeRecovery);
2400 if (sym.exists()) return sym;
2401 else bestSoFar = bestOf(bestSoFar, sym);
2402 }
2403
2404 return bestSoFar;
2405 }
2406
2407 /** Find an unqualified identifier which matches a specified kind set.
2408 * @param pos position on which report warnings, if any;
2409 * null warnings should not be reported
2410 * @param env The current environment.
2411 * @param name The identifier's name.
2412 * @param kind Indicates the possible symbol kinds
2413 * (a subset of VAL, TYP, PCK).
2414 */
2415 Symbol findIdent(DiagnosticPosition pos, Env<AttrContext> env, Name name, KindSelector kind) {
2416 return checkRestrictedType(pos, findIdentInternal(env, name, kind), name);
2417 }
2418
2419 Symbol findIdentInternal(Env<AttrContext> env, Name name, KindSelector kind) {
2420 Symbol bestSoFar = typeNotFound;
2421 Symbol sym;
2422
2423 if (kind.contains(KindSelector.VAL)) {
2424 sym = findVar(env, name);
2425 if (sym.exists()) return sym;
2426 else bestSoFar = bestOf(bestSoFar, sym);
2427 }
2428
2429 if (kind.contains(KindSelector.TYP)) {
2430 sym = findType(env, name);
2431
2432 if (sym.exists()) return sym;
2433 else bestSoFar = bestOf(bestSoFar, sym);
2434 }
2435
2436 if (kind.contains(KindSelector.PCK))
2437 return lookupPackage(env, name);
2438 else return bestSoFar;
2439 }
2440
2441 /** Find an identifier in a package which matches a specified kind set.
2442 * @param pos position on which report warnings, if any;
2443 * null warnings should not be reported
2444 * @param env The current environment.
2445 * @param name The identifier's name.
2446 * @param kind Indicates the possible symbol kinds
2447 * (a nonempty subset of TYP, PCK).
2448 */
2449 Symbol findIdentInPackage(DiagnosticPosition pos,
2450 Env<AttrContext> env, TypeSymbol pck,
2451 Name name, KindSelector kind) {
2452 return checkRestrictedType(pos, findIdentInPackageInternal(env, pck, name, kind), name);
2453 }
2454
2455 Symbol findIdentInPackageInternal(Env<AttrContext> env, TypeSymbol pck,
2456 Name name, KindSelector kind) {
2457 Name fullname = TypeSymbol.formFullName(name, pck);
2458 Symbol bestSoFar = typeNotFound;
2459 if (kind.contains(KindSelector.TYP)) {
2460 RecoveryLoadClass recoveryLoadClass =
2461 allowModules && !kind.contains(KindSelector.PCK) &&
2462 !pck.exists() && !env.info.attributionMode.isSpeculative ?
2463 doRecoveryLoadClass : noRecovery;
2464 Symbol sym = loadClass(env, fullname, recoveryLoadClass);
2465 if (sym.exists()) {
2466 // don't allow programs to use flatnames
2467 if (name == sym.name) return sym;
2468 }
2469 else bestSoFar = bestOf(bestSoFar, sym);
2470 }
2471 if (kind.contains(KindSelector.PCK)) {
2472 return lookupPackage(env, fullname);
2473 }
2474 return bestSoFar;
2475 }
2476
2477 /** Find an identifier among the members of a given type `site'.
2478 * @param pos position on which report warnings, if any;
2479 * null warnings should not be reported
2480 * @param env The current environment.
2481 * @param site The type containing the symbol to be found.
2482 * @param name The identifier's name.
2483 * @param kind Indicates the possible symbol kinds
2484 * (a subset of VAL, TYP).
2485 */
2486 Symbol findIdentInType(DiagnosticPosition pos,
2487 Env<AttrContext> env, Type site,
2488 Name name, KindSelector kind) {
2489 return checkRestrictedType(pos, findIdentInTypeInternal(env, site, name, kind), name);
2490 }
2491
2492 Symbol findIdentInTypeInternal(Env<AttrContext> env, Type site,
2493 Name name, KindSelector kind) {
2494 Symbol bestSoFar = typeNotFound;
2495 Symbol sym;
2496 if (kind.contains(KindSelector.VAL)) {
2497 sym = findField(env, site, name, site.tsym);
2498 if (sym.exists()) return sym;
2499 else bestSoFar = bestOf(bestSoFar, sym);
2500 }
2501
2502 if (kind.contains(KindSelector.TYP)) {
2503 sym = findMemberType(env, site, name, site.tsym);
2504 if (sym.exists()) return sym;
2505 else bestSoFar = bestOf(bestSoFar, sym);
2506 }
2507 return bestSoFar;
2508 }
2509
2510 private Symbol checkRestrictedType(DiagnosticPosition pos, Symbol bestSoFar, Name name) {
2511 if (bestSoFar.kind == TYP || bestSoFar.kind == ABSENT_TYP) {
2512 if (allowLocalVariableTypeInference && name.equals(names.var)) {
2513 bestSoFar = new BadRestrictedTypeError(names.var);
2514 } else if (name.equals(names.yield)) {
2515 if (allowYieldStatement) {
2516 bestSoFar = new BadRestrictedTypeError(names.yield);
2517 } else if (pos != null) {
2518 log.warning(pos, Warnings.IllegalRefToRestrictedType(names.yield));
2519 }
2520 }
2521 }
2522 return bestSoFar;
2523 }
2524
2525 /* ***************************************************************************
2526 * Access checking
2527 * The following methods convert ResolveErrors to ErrorSymbols, issuing
2528 * an error message in the process
2529 ****************************************************************************/
2530
2531 /** If `sym' is a bad symbol: report error and return errSymbol
2532 * else pass through unchanged,
2533 * additional arguments duplicate what has been used in trying to find the
2534 * symbol {@literal (--> flyweight pattern)}. This improves performance since we
2535 * expect misses to happen frequently.
2536 *
2537 * @param sym The symbol that was found, or a ResolveError.
2538 * @param pos The position to use for error reporting.
2539 * @param location The symbol the served as a context for this lookup
2540 * @param site The original type from where the selection took place.
2541 * @param name The symbol's name.
2542 * @param qualified Did we get here through a qualified expression resolution?
2543 * @param argtypes The invocation's value arguments,
2544 * if we looked for a method.
2545 * @param typeargtypes The invocation's type arguments,
2546 * if we looked for a method.
2547 * @param logResolveHelper helper class used to log resolve errors
2548 */
2549 Symbol accessInternal(Symbol sym,
2550 DiagnosticPosition pos,
2551 Symbol location,
2552 Type site,
2553 Name name,
2554 boolean qualified,
2555 List<Type> argtypes,
2556 List<Type> typeargtypes,
2557 LogResolveHelper logResolveHelper) {
2558 if (sym.kind.isResolutionError()) {
2559 ResolveError errSym = (ResolveError)sym.baseSymbol();
2560 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
2561 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes);
2562 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) {
2563 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
2564 }
2565 }
2566 return sym;
2567 }
2568
2569 /**
2570 * Variant of the generalized access routine, to be used for generating method
2571 * resolution diagnostics
2572 */
2573 Symbol accessMethod(Symbol sym,
2574 DiagnosticPosition pos,
2575 Symbol location,
2576 Type site,
2577 Name name,
2578 boolean qualified,
2579 List<Type> argtypes,
2580 List<Type> typeargtypes) {
2581 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper);
2582 }
2583
2584 /** Same as original accessMethod(), but without location.
2585 */
2586 Symbol accessMethod(Symbol sym,
2587 DiagnosticPosition pos,
2588 Type site,
2589 Name name,
2590 boolean qualified,
2591 List<Type> argtypes,
2592 List<Type> typeargtypes) {
2593 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
2594 }
2595
2596 /**
2597 * Variant of the generalized access routine, to be used for generating variable,
2598 * type resolution diagnostics
2599 */
2600 Symbol accessBase(Symbol sym,
2601 DiagnosticPosition pos,
2602 Symbol location,
2603 Type site,
2604 Name name,
2605 boolean qualified) {
2606 return accessInternal(sym, pos, location, site, name, qualified, List.nil(), null, basicLogResolveHelper);
2607 }
2608
2609 /** Same as original accessBase(), but without location.
2610 */
2611 Symbol accessBase(Symbol sym,
2612 DiagnosticPosition pos,
2613 Type site,
2614 Name name,
2615 boolean qualified) {
2616 return accessBase(sym, pos, site.tsym, site, name, qualified);
2617 }
2618
2619 interface LogResolveHelper {
2620 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes);
2621 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes);
2622 }
2623
2624 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() {
2625 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2626 return !site.isErroneous();
2627 }
2628 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2629 return argtypes;
2630 }
2631 };
2632
2633 LogResolveHelper silentLogResolveHelper = new LogResolveHelper() {
2634 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2635 return false;
2636 }
2637 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2638 return argtypes;
2639 }
2640 };
2641
2642 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() {
2643 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2644 return !site.isErroneous() &&
2645 !Type.isErroneous(argtypes) &&
2646 (typeargtypes == null || !Type.isErroneous(typeargtypes));
2647 }
2648 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2649 return argtypes.map(new ResolveDeferredRecoveryMap(AttrMode.SPECULATIVE, accessedSym, currentResolutionContext.step));
2650 }
2651 };
2652
2653 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap {
2654
2655 public ResolveDeferredRecoveryMap(AttrMode mode, Symbol msym, MethodResolutionPhase step) {
2656 deferredAttr.super(mode, msym, step);
2657 }
2658
2659 @Override
2660 protected Type typeOf(DeferredType dt, Type pt) {
2661 Type res = super.typeOf(dt, pt);
2662 if (!res.isErroneous()) {
2663 switch (TreeInfo.skipParens(dt.tree).getTag()) {
2664 case LAMBDA:
2665 case REFERENCE:
2666 return dt;
2667 case CONDEXPR:
2668 return res == Type.recoveryType ?
2669 dt : res;
2670 }
2671 }
2672 return res;
2673 }
2674 }
2675
2676 /** Check that sym is not an abstract method.
2677 */
2678 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
2679 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0)
2680 log.error(pos,
2681 Errors.AbstractCantBeAccessedDirectly(kindName(sym),sym, sym.location()));
2682 }
2683
2684 /* ***************************************************************************
2685 * Name resolution
2686 * Naming conventions are as for symbol lookup
2687 * Unlike the find... methods these methods will report access errors
2688 ****************************************************************************/
2689
2690 /** Resolve an unqualified (non-method) identifier.
2691 * @param pos The position to use for error reporting.
2692 * @param env The environment current at the identifier use.
2693 * @param name The identifier's name.
2694 * @param kind The set of admissible symbol kinds for the identifier.
2695 */
2696 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
2697 Name name, KindSelector kind) {
2698 return accessBase(
2699 findIdent(pos, env, name, kind),
2700 pos, env.enclClass.sym.type, name, false);
2701 }
2702
2703 /** Resolve an unqualified method identifier.
2704 * @param pos The position to use for error reporting.
2705 * @param env The environment current at the method invocation.
2706 * @param name The identifier's name.
2707 * @param argtypes The types of the invocation's value arguments.
2708 * @param typeargtypes The types of the invocation's type arguments.
2709 */
2710 Symbol resolveMethod(DiagnosticPosition pos,
2711 Env<AttrContext> env,
2712 Name name,
2713 List<Type> argtypes,
2714 List<Type> typeargtypes) {
2715 return lookupMethod(env, pos, env.enclClass.sym, resolveMethodCheck,
2716 new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) {
2717 @Override
2718 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2719 return findFun(env, name, argtypes, typeargtypes,
2720 phase.isBoxingRequired(),
2721 phase.isVarargsRequired());
2722 }});
2723 }
2724
2725 /** Resolve a qualified method identifier
2726 * @param pos The position to use for error reporting.
2727 * @param env The environment current at the method invocation.
2728 * @param site The type of the qualifying expression, in which
2729 * identifier is searched.
2730 * @param name The identifier's name.
2731 * @param argtypes The types of the invocation's value arguments.
2732 * @param typeargtypes The types of the invocation's type arguments.
2733 */
2734 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2735 Type site, Name name, List<Type> argtypes,
2736 List<Type> typeargtypes) {
2737 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
2738 }
2739 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2740 Symbol location, Type site, Name name, List<Type> argtypes,
2741 List<Type> typeargtypes) {
2742 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
2743 }
2744 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
2745 DiagnosticPosition pos, Env<AttrContext> env,
2746 Symbol location, Type site, Name name, List<Type> argtypes,
2747 List<Type> typeargtypes) {
2748 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) {
2749 @Override
2750 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2751 return findMethod(env, site, name, argtypes, typeargtypes,
2752 phase.isBoxingRequired(),
2753 phase.isVarargsRequired());
2754 }
2755 @Override
2756 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2757 if (sym.kind.isResolutionError()) {
2758 sym = super.access(env, pos, location, sym);
2759 } else {
2760 MethodSymbol msym = (MethodSymbol)sym;
2761 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) {
2762 env.info.pendingResolutionPhase = BASIC;
2763 return findPolymorphicSignatureInstance(env, sym, argtypes);
2764 }
2765 }
2766 return sym;
2767 }
2768 });
2769 }
2770
2771 /** Find or create an implicit method of exactly the given type (after erasure).
2772 * Searches in a side table, not the main scope of the site.
2773 * This emulates the lookup process required by JSR 292 in JVM.
2774 * @param env Attribution environment
2775 * @param spMethod signature polymorphic method - i.e. MH.invokeExact
2776 * @param argtypes The required argument types
2777 */
2778 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env,
2779 final Symbol spMethod,
2780 List<Type> argtypes) {
2781 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
2782 (MethodSymbol)spMethod, currentResolutionContext, argtypes);
2783 return findPolymorphicSignatureInstance(spMethod, mtype);
2784 }
2785
2786 Symbol findPolymorphicSignatureInstance(final Symbol spMethod,
2787 Type mtype) {
2788 for (Symbol sym : polymorphicSignatureScope.getSymbolsByName(spMethod.name)) {
2789 // Check that there is already a method symbol for the method
2790 // type and owner
2791 if (types.isSameType(mtype, sym.type) &&
2792 spMethod.owner == sym.owner) {
2793 return sym;
2794 }
2795 }
2796
2797 Type spReturnType = spMethod.asType().getReturnType();
2798 if (types.isSameType(spReturnType, syms.objectType)) {
2799 // Polymorphic return, pass through mtype
2800 } else if (!types.isSameType(spReturnType, mtype.getReturnType())) {
2801 // Retain the sig poly method's return type, which differs from that of mtype
2802 // Will result in an incompatible return type error
2803 mtype = new MethodType(mtype.getParameterTypes(),
2804 spReturnType,
2805 mtype.getThrownTypes(),
2806 syms.methodClass);
2807 }
2808
2809 // Create the desired method
2810 // Retain static modifier is to support invocations to
2811 // MethodHandle.linkTo* methods
2812 long flags = ABSTRACT | HYPOTHETICAL |
2813 spMethod.flags() & (Flags.AccessFlags | Flags.STATIC);
2814 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) {
2815 @Override
2816 public Symbol baseSymbol() {
2817 return spMethod;
2818 }
2819 };
2820 if (!mtype.isErroneous()) { // Cache only if kosher.
2821 polymorphicSignatureScope.enter(msym);
2822 }
2823 return msym;
2824 }
2825
2826 /** Resolve a qualified method identifier, throw a fatal error if not
2827 * found.
2828 * @param pos The position to use for error reporting.
2829 * @param env The environment current at the method invocation.
2830 * @param site The type of the qualifying expression, in which
2831 * identifier is searched.
2832 * @param name The identifier's name.
2833 * @param argtypes The types of the invocation's value arguments.
2834 * @param typeargtypes The types of the invocation's type arguments.
2835 */
2836 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
2837 Type site, Name name,
2838 List<Type> argtypes,
2839 List<Type> typeargtypes) {
2840 MethodResolutionContext resolveContext = new MethodResolutionContext();
2841 resolveContext.internalResolution = true;
2842 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
2843 site, name, argtypes, typeargtypes);
2844 if (sym.kind == MTH) return (MethodSymbol)sym;
2845 else throw new FatalError(
2846 diags.fragment(Fragments.FatalErrCantLocateMeth(name)));
2847 }
2848
2849 /** Resolve constructor.
2850 * @param pos The position to use for error reporting.
2851 * @param env The environment current at the constructor invocation.
2852 * @param site The type of class for which a constructor is searched.
2853 * @param argtypes The types of the constructor invocation's value
2854 * arguments.
2855 * @param typeargtypes The types of the constructor invocation's type
2856 * arguments.
2857 */
2858 Symbol resolveConstructor(DiagnosticPosition pos,
2859 Env<AttrContext> env,
2860 Type site,
2861 List<Type> argtypes,
2862 List<Type> typeargtypes) {
2863 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
2864 }
2865
2866 private Symbol resolveConstructor(MethodResolutionContext resolveContext,
2867 final DiagnosticPosition pos,
2868 Env<AttrContext> env,
2869 Type site,
2870 List<Type> argtypes,
2871 List<Type> typeargtypes) {
2872 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2873 @Override
2874 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2875 return findConstructor(pos, env, site, argtypes, typeargtypes,
2876 phase.isBoxingRequired(),
2877 phase.isVarargsRequired());
2878 }
2879 });
2880 }
2881
2882 /** Resolve a constructor, throw a fatal error if not found.
2883 * @param pos The position to use for error reporting.
2884 * @param env The environment current at the method invocation.
2885 * @param site The type to be constructed.
2886 * @param argtypes The types of the invocation's value arguments.
2887 * @param typeargtypes The types of the invocation's type arguments.
2888 */
2889 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2890 Type site,
2891 List<Type> argtypes,
2892 List<Type> typeargtypes) {
2893 MethodResolutionContext resolveContext = new MethodResolutionContext();
2894 resolveContext.internalResolution = true;
2895 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
2896 if (sym.kind == MTH) return (MethodSymbol)sym;
2897 else throw new FatalError(
2898 diags.fragment(Fragments.FatalErrCantLocateCtor(site)));
2899 }
2900
2901 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2902 Type site, List<Type> argtypes,
2903 List<Type> typeargtypes,
2904 boolean allowBoxing,
2905 boolean useVarargs) {
2906 Symbol sym = findMethod(env, site,
2907 names.init, argtypes,
2908 typeargtypes, allowBoxing,
2909 useVarargs);
2910 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2911 chk.checkPreview(pos, env.info.scope.owner, sym);
2912 return sym;
2913 }
2914
2915 /** Resolve constructor using diamond inference.
2916 * @param pos The position to use for error reporting.
2917 * @param env The environment current at the constructor invocation.
2918 * @param site The type of class for which a constructor is searched.
2919 * The scope of this class has been touched in attribution.
2920 * @param argtypes The types of the constructor invocation's value
2921 * arguments.
2922 * @param typeargtypes The types of the constructor invocation's type
2923 * arguments.
2924 */
2925 Symbol resolveDiamond(DiagnosticPosition pos,
2926 Env<AttrContext> env,
2927 Type site,
2928 List<Type> argtypes,
2929 List<Type> typeargtypes) {
2930 return lookupMethod(env, pos, site.tsym, resolveMethodCheck,
2931 new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2932 @Override
2933 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2934 return findDiamond(pos, env, site, argtypes, typeargtypes,
2935 phase.isBoxingRequired(),
2936 phase.isVarargsRequired());
2937 }
2938 @Override
2939 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2940 if (sym.kind.isResolutionError()) {
2941 if (sym.kind != WRONG_MTH &&
2942 sym.kind != WRONG_MTHS) {
2943 sym = super.access(env, pos, location, sym);
2944 } else {
2945 sym = new DiamondError(sym, currentResolutionContext);
2946 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes);
2947 env.info.pendingResolutionPhase = currentResolutionContext.step;
2948 }
2949 }
2950 return sym;
2951 }});
2952 }
2953
2954 /** Find the constructor using diamond inference and do some checks(deprecated and preview).
2955 * @param pos The position to use for error reporting.
2956 * @param env The environment current at the constructor invocation.
2957 * @param site The type of class for which a constructor is searched.
2958 * The scope of this class has been touched in attribution.
2959 * @param argtypes The types of the constructor invocation's value arguments.
2960 * @param typeargtypes The types of the constructor invocation's type arguments.
2961 * @param allowBoxing Allow boxing conversions of arguments.
2962 * @param useVarargs Box trailing arguments into an array for varargs.
2963 */
2964 private Symbol findDiamond(DiagnosticPosition pos,
2965 Env<AttrContext> env,
2966 Type site,
2967 List<Type> argtypes,
2968 List<Type> typeargtypes,
2969 boolean allowBoxing,
2970 boolean useVarargs) {
2971 Symbol sym = findDiamond(env, site, argtypes, typeargtypes, allowBoxing, useVarargs);
2972 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2973 chk.checkPreview(pos, env.info.scope.owner, sym);
2974 return sym;
2975 }
2976
2977 /** This method scans all the constructor symbol in a given class scope -
2978 * assuming that the original scope contains a constructor of the kind:
2979 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
2980 * a method check is executed against the modified constructor type:
2981 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond
2982 * inference. The inferred return type of the synthetic constructor IS
2983 * the inferred type for the diamond operator.
2984 */
2985 private Symbol findDiamond(Env<AttrContext> env,
2986 Type site,
2987 List<Type> argtypes,
2988 List<Type> typeargtypes,
2989 boolean allowBoxing,
2990 boolean useVarargs) {
2991 Symbol bestSoFar = methodNotFound;
2992 TypeSymbol tsym = site.tsym.isInterface() ? syms.objectType.tsym : site.tsym;
2993 for (final Symbol sym : tsym.members().getSymbolsByName(names.init)) {
2994 //- System.out.println(" e " + e.sym);
2995 if (sym.kind == MTH &&
2996 (sym.flags_field & SYNTHETIC) == 0) {
2997 List<Type> oldParams = sym.type.hasTag(FORALL) ?
2998 ((ForAll)sym.type).tvars :
2999 List.nil();
3000 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
3001 types.createMethodTypeWithReturn(sym.type.asMethodType(), site));
3002 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) {
3003 @Override
3004 public Symbol baseSymbol() {
3005 return sym;
3006 }
3007 };
3008 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
3009 newConstr,
3010 bestSoFar,
3011 allowBoxing,
3012 useVarargs);
3013 }
3014 }
3015 return bestSoFar;
3016 }
3017
3018 Symbol getMemberReference(DiagnosticPosition pos,
3019 Env<AttrContext> env,
3020 JCMemberReference referenceTree,
3021 Type site,
3022 Name name) {
3023
3024 site = types.capture(site);
3025
3026 ReferenceLookupHelper lookupHelper = makeReferenceLookupHelper(
3027 referenceTree, site, name, List.nil(), null, VARARITY);
3028
3029 Env<AttrContext> newEnv = env.dup(env.tree, env.info.dup());
3030 Symbol sym = lookupMethod(newEnv, env.tree.pos(), site.tsym,
3031 nilMethodCheck, lookupHelper);
3032
3033 env.info.pendingResolutionPhase = newEnv.info.pendingResolutionPhase;
3034
3035 return sym;
3036 }
3037
3038 ReferenceLookupHelper makeReferenceLookupHelper(JCMemberReference referenceTree,
3039 Type site,
3040 Name name,
3041 List<Type> argtypes,
3042 List<Type> typeargtypes,
3043 MethodResolutionPhase maxPhase) {
3044 if (!name.equals(names.init)) {
3045 //method reference
3046 return new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
3047 } else if (site.hasTag(ARRAY)) {
3048 //array constructor reference
3049 return new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
3050 } else {
3051 //class constructor reference
3052 return new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
3053 }
3054 }
3055
3056 /**
3057 * Resolution of member references is typically done as a single
3058 * overload resolution step, where the argument types A are inferred from
3059 * the target functional descriptor.
3060 *
3061 * If the member reference is a method reference with a type qualifier,
3062 * a two-step lookup process is performed. The first step uses the
3063 * expected argument list A, while the second step discards the first
3064 * type from A (which is treated as a receiver type).
3065 *
3066 * There are two cases in which inference is performed: (i) if the member
3067 * reference is a constructor reference and the qualifier type is raw - in
3068 * which case diamond inference is used to infer a parameterization for the
3069 * type qualifier; (ii) if the member reference is an unbound reference
3070 * where the type qualifier is raw - in that case, during the unbound lookup
3071 * the receiver argument type is used to infer an instantiation for the raw
3072 * qualifier type.
3073 *
3074 * When a multi-step resolution process is exploited, the process of picking
3075 * the resulting symbol is delegated to an helper class {@link com.sun.tools.javac.comp.Resolve.ReferenceChooser}.
3076 *
3077 * This routine returns a pair (T,S), where S is the member reference symbol,
3078 * and T is the type of the class in which S is defined. This is necessary as
3079 * the type T might be dynamically inferred (i.e. if constructor reference
3080 * has a raw qualifier).
3081 */
3082 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(Env<AttrContext> env,
3083 JCMemberReference referenceTree,
3084 Type site,
3085 Name name,
3086 List<Type> argtypes,
3087 List<Type> typeargtypes,
3088 Type descriptor,
3089 MethodCheck methodCheck,
3090 InferenceContext inferenceContext,
3091 ReferenceChooser referenceChooser) {
3092
3093 //step 1 - bound lookup
3094 ReferenceLookupHelper boundLookupHelper = makeReferenceLookupHelper(
3095 referenceTree, site, name, argtypes, typeargtypes, VARARITY);
3096 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup());
3097 MethodResolutionContext boundSearchResolveContext = new MethodResolutionContext();
3098 boundSearchResolveContext.methodCheck = methodCheck;
3099 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(),
3100 site.tsym, boundSearchResolveContext, boundLookupHelper);
3101 ReferenceLookupResult boundRes = new ReferenceLookupResult(boundSym, boundSearchResolveContext);
3102 if (dumpMethodReferenceSearchResults) {
3103 dumpMethodReferenceSearchResults(referenceTree, boundSearchResolveContext, boundSym, true);
3104 }
3105
3106 //step 2 - unbound lookup
3107 Symbol unboundSym = methodNotFound;
3108 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup());
3109 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup(inferenceContext);
3110 ReferenceLookupResult unboundRes = referenceNotFound;
3111 if (unboundLookupHelper != null) {
3112 MethodResolutionContext unboundSearchResolveContext =
3113 new MethodResolutionContext();
3114 unboundSearchResolveContext.methodCheck = methodCheck;
3115 unboundSym = lookupMethod(unboundEnv, env.tree.pos(),
3116 site.tsym, unboundSearchResolveContext, unboundLookupHelper);
3117 unboundRes = new ReferenceLookupResult(unboundSym, unboundSearchResolveContext);
3118 if (dumpMethodReferenceSearchResults) {
3119 dumpMethodReferenceSearchResults(referenceTree, unboundSearchResolveContext, unboundSym, false);
3120 }
3121 }
3122
3123 //merge results
3124 Pair<Symbol, ReferenceLookupHelper> res;
3125 ReferenceLookupResult bestRes = referenceChooser.result(boundRes, unboundRes);
3126 res = new Pair<>(bestRes.sym,
3127 bestRes == unboundRes ? unboundLookupHelper : boundLookupHelper);
3128 env.info.pendingResolutionPhase = bestRes == unboundRes ?
3129 unboundEnv.info.pendingResolutionPhase :
3130 boundEnv.info.pendingResolutionPhase;
3131
3132 if (!res.fst.kind.isResolutionError()) {
3133 //handle sigpoly method references
3134 MethodSymbol msym = (MethodSymbol)res.fst;
3135 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) {
3136 env.info.pendingResolutionPhase = BASIC;
3137 res = new Pair<>(findPolymorphicSignatureInstance(msym, descriptor), res.snd);
3138 }
3139 }
3140
3141 return res;
3142 }
3143
3144 private void dumpMethodReferenceSearchResults(JCMemberReference referenceTree,
3145 MethodResolutionContext resolutionContext,
3146 Symbol bestSoFar,
3147 boolean bound) {
3148 ListBuffer<JCDiagnostic> subDiags = new ListBuffer<>();
3149 int pos = 0;
3150 int mostSpecificPos = -1;
3151 for (Candidate c : resolutionContext.candidates) {
3152 if (resolutionContext.step != c.step || !c.isApplicable()) {
3153 continue;
3154 } else {
3155 JCDiagnostic subDiag = null;
3156 if (c.sym.type.hasTag(FORALL)) {
3157 subDiag = diags.fragment(Fragments.PartialInstSig(c.mtype));
3158 }
3159
3160 String key = subDiag == null ?
3161 "applicable.method.found.2" :
3162 "applicable.method.found.3";
3163 subDiags.append(diags.fragment(key, pos,
3164 c.sym.isStatic() ? Fragments.Static : Fragments.NonStatic, c.sym, subDiag));
3165 if (c.sym == bestSoFar)
3166 mostSpecificPos = pos;
3167 pos++;
3168 }
3169 }
3170 JCDiagnostic main = diags.note(
3171 log.currentSource(),
3172 referenceTree,
3173 "method.ref.search.results.multi",
3174 bound ? Fragments.Bound : Fragments.Unbound,
3175 referenceTree.toString(), mostSpecificPos);
3176 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
3177 log.report(d);
3178 }
3179
3180 /**
3181 * This class is used to represent a method reference lookup result. It keeps track of two
3182 * things: (i) the symbol found during a method reference lookup and (ii) the static kind
3183 * of the lookup (see {@link com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind}).
3184 */
3185 static class ReferenceLookupResult {
3186
3187 /**
3188 * Static kind associated with a method reference lookup. Erroneous lookups end up with
3189 * the UNDEFINED kind; successful lookups will end up with either STATIC, NON_STATIC,
3190 * depending on whether all applicable candidates are static or non-static methods,
3191 * respectively. If a successful lookup has both static and non-static applicable methods,
3192 * its kind is set to BOTH.
3193 */
3194 enum StaticKind {
3195 STATIC,
3196 NON_STATIC,
3197 BOTH,
3198 UNDEFINED;
3199
3200 /**
3201 * Retrieve the static kind associated with a given (method) symbol.
3202 */
3203 static StaticKind from(Symbol s) {
3204 return s.isStatic() ?
3205 STATIC : NON_STATIC;
3206 }
3207
3208 /**
3209 * Merge two static kinds together.
3210 */
3211 static StaticKind reduce(StaticKind sk1, StaticKind sk2) {
3212 if (sk1 == UNDEFINED) {
3213 return sk2;
3214 } else if (sk2 == UNDEFINED) {
3215 return sk1;
3216 } else {
3217 return sk1 == sk2 ? sk1 : BOTH;
3218 }
3219 }
3220 }
3221
3222 /** The static kind. */
3223 StaticKind staticKind;
3224
3225 /** The lookup result. */
3226 Symbol sym;
3227
3228 ReferenceLookupResult(Symbol sym, MethodResolutionContext resolutionContext) {
3229 this(sym, staticKind(sym, resolutionContext));
3230 }
3231
3232 private ReferenceLookupResult(Symbol sym, StaticKind staticKind) {
3233 this.staticKind = staticKind;
3234 this.sym = sym;
3235 }
3236
3237 private static StaticKind staticKind(Symbol sym, MethodResolutionContext resolutionContext) {
3238 switch (sym.kind) {
3239 case MTH:
3240 case AMBIGUOUS:
3241 return resolutionContext.candidates.stream()
3242 .filter(c -> c.isApplicable() && c.step == resolutionContext.step)
3243 .map(c -> StaticKind.from(c.sym))
3244 .reduce(StaticKind::reduce)
3245 .orElse(StaticKind.UNDEFINED);
3246 default:
3247 return StaticKind.UNDEFINED;
3248 }
3249 }
3250
3251 /**
3252 * Does this result corresponds to a successful lookup (i.e. one where a method has been found?)
3253 */
3254 boolean isSuccess() {
3255 return staticKind != StaticKind.UNDEFINED;
3256 }
3257
3258 /**
3259 * Does this result have given static kind?
3260 */
3261 boolean hasKind(StaticKind sk) {
3262 return this.staticKind == sk;
3263 }
3264
3265 /**
3266 * Error recovery helper: can this lookup result be ignored (for the purpose of returning
3267 * some 'better' result) ?
3268 */
3269 boolean canIgnore() {
3270 switch (sym.kind) {
3271 case ABSENT_MTH:
3272 return true;
3273 case WRONG_MTH:
3274 InapplicableSymbolError errSym =
3275 (InapplicableSymbolError)sym.baseSymbol();
3276 return new Template(MethodCheckDiag.ARITY_MISMATCH.regex())
3277 .matches(errSym.errCandidate().snd);
3278 case WRONG_MTHS:
3279 InapplicableSymbolsError errSyms =
3280 (InapplicableSymbolsError)sym.baseSymbol();
3281 return errSyms.filterCandidates(errSyms.mapCandidates()).isEmpty();
3282 default:
3283 return false;
3284 }
3285 }
3286
3287 static ReferenceLookupResult error(Symbol sym) {
3288 return new ReferenceLookupResult(sym, StaticKind.UNDEFINED);
3289 }
3290 }
3291
3292 /**
3293 * This abstract class embodies the logic that converts one (bound lookup) or two (unbound lookup)
3294 * {@code ReferenceLookupResult} objects into a (@code Symbol), which is then regarded as the
3295 * result of method reference resolution.
3296 */
3297 abstract class ReferenceChooser {
3298 /**
3299 * Generate a result from a pair of lookup result objects. This method delegates to the
3300 * appropriate result generation routine.
3301 */
3302 ReferenceLookupResult result(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3303 return unboundRes != referenceNotFound ?
3304 unboundResult(boundRes, unboundRes) :
3305 boundResult(boundRes);
3306 }
3307
3308 /**
3309 * Generate a symbol from a given bound lookup result.
3310 */
3311 abstract ReferenceLookupResult boundResult(ReferenceLookupResult boundRes);
3312
3313 /**
3314 * Generate a symbol from a pair of bound/unbound lookup results.
3315 */
3316 abstract ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes);
3317 }
3318
3319 /**
3320 * This chooser implements the selection strategy used during a full lookup; this logic
3321 * is described in JLS SE 8 (15.3.2).
3322 */
3323 ReferenceChooser basicReferenceChooser = new ReferenceChooser() {
3324
3325 @Override
3326 ReferenceLookupResult boundResult(ReferenceLookupResult boundRes) {
3327 return !boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC) ?
3328 boundRes : //the search produces a non-static method
3329 ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.sym, false));
3330 }
3331
3332 @Override
3333 ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3334 if (boundRes.isSuccess() && boundRes.sym.isStatic() &&
3335 (!unboundRes.isSuccess() || unboundRes.hasKind(StaticKind.STATIC))) {
3336 //the first search produces a static method and no non-static method is applicable
3337 //during the second search
3338 return boundRes;
3339 } else if (unboundRes.isSuccess() && !unboundRes.sym.isStatic() &&
3340 (!boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC))) {
3341 //the second search produces a non-static method and no static method is applicable
3342 //during the first search
3343 return unboundRes;
3344 } else if (boundRes.isSuccess() && unboundRes.isSuccess()) {
3345 //both searches produce some result; ambiguity (error recovery)
3346 return ReferenceLookupResult.error(ambiguityError(boundRes.sym, unboundRes.sym));
3347 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) {
3348 //Both searches failed to produce a result with correct staticness (i.e. first search
3349 //produces an non-static method). Alternatively, a given search produced a result
3350 //with the right staticness, but the other search has applicable methods with wrong
3351 //staticness (error recovery)
3352 return ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.isSuccess() ?
3353 boundRes.sym : unboundRes.sym, true));
3354 } else {
3355 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery)
3356 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ?
3357 unboundRes : boundRes;
3358 }
3359 }
3360 };
3361
3362 /**
3363 * This chooser implements the selection strategy used during an arity-based lookup; this logic
3364 * is described in JLS SE 8 (15.12.2.1).
3365 */
3366 ReferenceChooser structuralReferenceChooser = new ReferenceChooser() {
3367
3368 @Override
3369 ReferenceLookupResult boundResult(ReferenceLookupResult boundRes) {
3370 return (!boundRes.isSuccess() || !boundRes.hasKind(StaticKind.STATIC)) ?
3371 boundRes : //the search has at least one applicable non-static method
3372 ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.sym, false));
3373 }
3374
3375 @Override
3376 ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3377 if (boundRes.isSuccess() && !boundRes.hasKind(StaticKind.NON_STATIC)) {
3378 //the first search has at least one applicable static method
3379 return boundRes;
3380 } else if (unboundRes.isSuccess() && !unboundRes.hasKind(StaticKind.STATIC)) {
3381 //the second search has at least one applicable non-static method
3382 return unboundRes;
3383 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) {
3384 //either the first search produces a non-static method, or second search produces
3385 //a non-static method (error recovery)
3386 return ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.isSuccess() ?
3387 boundRes.sym : unboundRes.sym, true));
3388 } else {
3389 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery)
3390 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ?
3391 unboundRes : boundRes;
3392 }
3393 }
3394 };
3395
3396 /**
3397 * Helper for defining custom method-like lookup logic; a lookup helper
3398 * provides hooks for (i) the actual lookup logic and (ii) accessing the
3399 * lookup result (this step might result in compiler diagnostics to be generated)
3400 */
3401 abstract class LookupHelper {
3402
3403 /** name of the symbol to lookup */
3404 Name name;
3405
3406 /** location in which the lookup takes place */
3407 Type site;
3408
3409 /** actual types used during the lookup */
3410 List<Type> argtypes;
3411
3412 /** type arguments used during the lookup */
3413 List<Type> typeargtypes;
3414
3415 /** Max overload resolution phase handled by this helper */
3416 MethodResolutionPhase maxPhase;
3417
3418 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3419 this.name = name;
3420 this.site = site;
3421 this.argtypes = argtypes;
3422 this.typeargtypes = typeargtypes;
3423 this.maxPhase = maxPhase;
3424 }
3425
3426 /**
3427 * Should lookup stop at given phase with given result
3428 */
3429 final boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
3430 return phase.ordinal() > maxPhase.ordinal() ||
3431 !sym.kind.isResolutionError() || sym.kind == AMBIGUOUS || sym.kind == STATICERR;
3432 }
3433
3434 /**
3435 * Search for a symbol under a given overload resolution phase - this method
3436 * is usually called several times, once per each overload resolution phase
3437 */
3438 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase);
3439
3440 /**
3441 * Dump overload resolution info
3442 */
3443 void debug(DiagnosticPosition pos, Symbol sym) {
3444 //do nothing
3445 }
3446
3447 /**
3448 * Validate the result of the lookup
3449 */
3450 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym);
3451 }
3452
3453 abstract class BasicLookupHelper extends LookupHelper {
3454
3455 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) {
3456 this(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY);
3457 }
3458
3459 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3460 super(name, site, argtypes, typeargtypes, maxPhase);
3461 }
3462
3463 @Override
3464 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3465 Symbol sym = doLookup(env, phase);
3466 if (sym.kind == AMBIGUOUS) {
3467 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
3468 sym = a_err.mergeAbstracts(site);
3469 }
3470 return sym;
3471 }
3472
3473 abstract Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase);
3474
3475 @Override
3476 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
3477 if (sym.kind.isResolutionError()) {
3478 //if nothing is found return the 'first' error
3479 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes);
3480 }
3481 return sym;
3482 }
3483
3484 @Override
3485 void debug(DiagnosticPosition pos, Symbol sym) {
3486 reportVerboseResolutionDiagnostic(pos, name, site, argtypes, typeargtypes, sym);
3487 }
3488 }
3489
3490 /**
3491 * Helper class for member reference lookup. A reference lookup helper
3492 * defines the basic logic for member reference lookup; a method gives
3493 * access to an 'unbound' helper used to perform an unbound member
3494 * reference lookup.
3495 */
3496 abstract class ReferenceLookupHelper extends LookupHelper {
3497
3498 /** The member reference tree */
3499 JCMemberReference referenceTree;
3500
3501 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3502 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3503 super(name, site, argtypes, typeargtypes, maxPhase);
3504 this.referenceTree = referenceTree;
3505 }
3506
3507 /**
3508 * Returns an unbound version of this lookup helper. By default, this
3509 * method returns an dummy lookup helper.
3510 */
3511 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3512 return null;
3513 }
3514
3515 /**
3516 * Get the kind of the member reference
3517 */
3518 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym);
3519
3520 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
3521 if (sym.kind == AMBIGUOUS) {
3522 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
3523 sym = a_err.mergeAbstracts(site);
3524 }
3525 //skip error reporting
3526 return sym;
3527 }
3528 }
3529
3530 /**
3531 * Helper class for method reference lookup. The lookup logic is based
3532 * upon Resolve.findMethod; in certain cases, this helper class has a
3533 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper).
3534 * In such cases, non-static lookup results are thrown away.
3535 */
3536 class MethodReferenceLookupHelper extends ReferenceLookupHelper {
3537
3538 /** The original method reference lookup site. */
3539 Type originalSite;
3540
3541 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3542 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3543 super(referenceTree, name, types.skipTypeVars(site, true), argtypes, typeargtypes, maxPhase);
3544 this.originalSite = site;
3545 }
3546
3547 @Override
3548 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3549 return findMethod(env, site, name, argtypes, typeargtypes,
3550 phase.isBoxingRequired(), phase.isVarargsRequired());
3551 }
3552
3553 @Override
3554 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3555 if (TreeInfo.isStaticSelector(referenceTree.expr, names)) {
3556 if (argtypes.nonEmpty() &&
3557 (argtypes.head.hasTag(NONE) ||
3558 types.isSubtypeUnchecked(inferenceContext.asUndetVar(argtypes.head), originalSite))) {
3559 return new UnboundMethodReferenceLookupHelper(referenceTree, name,
3560 originalSite, argtypes, typeargtypes, maxPhase);
3561 } else {
3562 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) {
3563 @Override
3564 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3565 return this;
3566 }
3567
3568 @Override
3569 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3570 return methodNotFound;
3571 }
3572
3573 @Override
3574 ReferenceKind referenceKind(Symbol sym) {
3575 Assert.error();
3576 return null;
3577 }
3578 };
3579 }
3580 } else {
3581 return super.unboundLookup(inferenceContext);
3582 }
3583 }
3584
3585 @Override
3586 ReferenceKind referenceKind(Symbol sym) {
3587 if (sym.isStatic()) {
3588 return ReferenceKind.STATIC;
3589 } else {
3590 Name selName = TreeInfo.name(referenceTree.getQualifierExpression());
3591 return selName != null && selName == names._super ?
3592 ReferenceKind.SUPER :
3593 ReferenceKind.BOUND;
3594 }
3595 }
3596 }
3597
3598 /**
3599 * Helper class for unbound method reference lookup. Essentially the same
3600 * as the basic method reference lookup helper; main difference is that static
3601 * lookup results are thrown away. If qualifier type is raw, an attempt to
3602 * infer a parameterized type is made using the first actual argument (that
3603 * would otherwise be ignored during the lookup).
3604 */
3605 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper {
3606
3607 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3608 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3609 super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase);
3610 if (site.isRaw() && !argtypes.head.hasTag(NONE)) {
3611 Type asSuperSite = types.asSuper(argtypes.head, site.tsym);
3612 this.site = types.skipTypeVars(asSuperSite, true);
3613 }
3614 }
3615
3616 @Override
3617 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3618 return this;
3619 }
3620
3621 @Override
3622 ReferenceKind referenceKind(Symbol sym) {
3623 return ReferenceKind.UNBOUND;
3624 }
3625 }
3626
3627 /**
3628 * Helper class for array constructor lookup; an array constructor lookup
3629 * is simulated by looking up a method that returns the array type specified
3630 * as qualifier, and that accepts a single int parameter (size of the array).
3631 */
3632 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper {
3633
3634 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
3635 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3636 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
3637 }
3638
3639 @Override
3640 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3641 WriteableScope sc = WriteableScope.create(syms.arrayClass);
3642 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym);
3643 arrayConstr.type = new MethodType(List.of(syms.intType), site, List.nil(), syms.methodClass);
3644 sc.enter(arrayConstr);
3645 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false);
3646 }
3647
3648 @Override
3649 ReferenceKind referenceKind(Symbol sym) {
3650 return ReferenceKind.ARRAY_CTOR;
3651 }
3652 }
3653
3654 /**
3655 * Helper class for constructor reference lookup. The lookup logic is based
3656 * upon either Resolve.findMethod or Resolve.findDiamond - depending on
3657 * whether the constructor reference needs diamond inference (this is the case
3658 * if the qualifier type is raw). A special erroneous symbol is returned
3659 * if the lookup returns the constructor of an inner class and there's no
3660 * enclosing instance in scope.
3661 */
3662 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper {
3663
3664 boolean needsInference;
3665
3666 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
3667 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3668 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
3669 if (site.isRaw()) {
3670 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym, site.getMetadata());
3671 needsInference = true;
3672 }
3673 }
3674
3675 @Override
3676 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3677 Symbol sym = needsInference ?
3678 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) :
3679 findMethod(env, site, name, argtypes, typeargtypes,
3680 phase.isBoxingRequired(), phase.isVarargsRequired());
3681 return enclosingInstanceMissing(env, site) ? new BadConstructorReferenceError(sym) : sym;
3682 }
3683
3684 @Override
3685 ReferenceKind referenceKind(Symbol sym) {
3686 return site.getEnclosingType().hasTag(NONE) ?
3687 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER;
3688 }
3689 }
3690
3691 /**
3692 * Main overload resolution routine. On each overload resolution step, a
3693 * lookup helper class is used to perform the method/constructor lookup;
3694 * at the end of the lookup, the helper is used to validate the results
3695 * (this last step might trigger overload resolution diagnostics).
3696 */
3697 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, MethodCheck methodCheck, LookupHelper lookupHelper) {
3698 MethodResolutionContext resolveContext = new MethodResolutionContext();
3699 resolveContext.methodCheck = methodCheck;
3700 return lookupMethod(env, pos, location, resolveContext, lookupHelper);
3701 }
3702
3703 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location,
3704 MethodResolutionContext resolveContext, LookupHelper lookupHelper) {
3705 MethodResolutionContext prevResolutionContext = currentResolutionContext;
3706 try {
3707 Symbol bestSoFar = methodNotFound;
3708 currentResolutionContext = resolveContext;
3709 for (MethodResolutionPhase phase : methodResolutionSteps) {
3710 if (lookupHelper.shouldStop(bestSoFar, phase))
3711 break;
3712 MethodResolutionPhase prevPhase = currentResolutionContext.step;
3713 Symbol prevBest = bestSoFar;
3714 currentResolutionContext.step = phase;
3715 Symbol sym = lookupHelper.lookup(env, phase);
3716 lookupHelper.debug(pos, sym);
3717 bestSoFar = phase.mergeResults(bestSoFar, sym);
3718 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase;
3719 }
3720 return lookupHelper.access(env, pos, location, bestSoFar);
3721 } finally {
3722 currentResolutionContext = prevResolutionContext;
3723 }
3724 }
3725
3726 /**
3727 * Resolve `c.name' where name == this or name == super.
3728 * @param pos The position to use for error reporting.
3729 * @param env The environment current at the expression.
3730 * @param c The qualifier.
3731 * @param name The identifier's name.
3732 */
3733 Symbol resolveSelf(DiagnosticPosition pos,
3734 Env<AttrContext> env,
3735 TypeSymbol c,
3736 Name name) {
3737 Env<AttrContext> env1 = env;
3738 boolean staticOnly = false;
3739 while (env1.outer != null) {
3740 if (isStatic(env1)) staticOnly = true;
3741 if (env1.enclClass.sym == c) {
3742 Symbol sym = env1.info.scope.findFirst(name);
3743 if (sym != null) {
3744 if (staticOnly) sym = new StaticError(sym);
3745 return accessBase(sym, pos, env.enclClass.sym.type,
3746 name, true);
3747 }
3748 }
3749 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
3750 env1 = env1.outer;
3751 }
3752 if (c.isInterface() &&
3753 name == names._super && !isStatic(env) &&
3754 types.isDirectSuperInterface(c, env.enclClass.sym)) {
3755 //this might be a default super call if one of the superinterfaces is 'c'
3756 for (Type t : pruneInterfaces(env.enclClass.type)) {
3757 if (t.tsym == c) {
3758 env.info.defaultSuperCallSite = t;
3759 return new VarSymbol(0, names._super,
3760 types.asSuper(env.enclClass.type, c), env.enclClass.sym);
3761 }
3762 }
3763 //find a direct super type that is a subtype of 'c'
3764 for (Type i : types.directSupertypes(env.enclClass.type)) {
3765 if (i.tsym.isSubClass(c, types) && i.tsym != c) {
3766 log.error(pos,
3767 Errors.IllegalDefaultSuperCall(c,
3768 Fragments.RedundantSupertype(c, i)));
3769 return syms.errSymbol;
3770 }
3771 }
3772 Assert.error();
3773 }
3774 log.error(pos, Errors.NotEnclClass(c));
3775 return syms.errSymbol;
3776 }
3777 //where
3778 private List<Type> pruneInterfaces(Type t) {
3779 ListBuffer<Type> result = new ListBuffer<>();
3780 for (Type t1 : types.interfaces(t)) {
3781 boolean shouldAdd = true;
3782 for (Type t2 : types.directSupertypes(t)) {
3783 if (t1 != t2 && !t2.hasTag(ERROR) && types.isSubtypeNoCapture(t2, t1)) {
3784 shouldAdd = false;
3785 }
3786 }
3787 if (shouldAdd) {
3788 result.append(t1);
3789 }
3790 }
3791 return result.toList();
3792 }
3793
3794
3795 /**
3796 * Resolve `c.this' for an enclosing class c that contains the
3797 * named member.
3798 * @param pos The position to use for error reporting.
3799 * @param env The environment current at the expression.
3800 * @param member The member that must be contained in the result.
3801 */
3802 Symbol resolveSelfContaining(DiagnosticPosition pos,
3803 Env<AttrContext> env,
3804 Symbol member,
3805 boolean isSuperCall) {
3806 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall);
3807 if (sym == null) {
3808 log.error(pos, Errors.EnclClassRequired(member));
3809 return syms.errSymbol;
3810 } else {
3811 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true);
3812 }
3813 }
3814
3815 boolean enclosingInstanceMissing(Env<AttrContext> env, Type type) {
3816 if (type.hasTag(CLASS) && type.getEnclosingType().hasTag(CLASS)) {
3817 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false);
3818 return encl == null || encl.kind.isResolutionError();
3819 }
3820 return false;
3821 }
3822
3823 private Symbol resolveSelfContainingInternal(Env<AttrContext> env,
3824 Symbol member,
3825 boolean isSuperCall) {
3826 Name name = names._this;
3827 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
3828 boolean staticOnly = false;
3829 if (env1 != null) {
3830 while (env1 != null && env1.outer != null) {
3831 if (isStatic(env1)) staticOnly = true;
3832 if (env1.enclClass.sym.isSubClass(member.owner.enclClass(), types)) {
3833 Symbol sym = env1.info.scope.findFirst(name);
3834 if (sym != null) {
3835 if (staticOnly) sym = new StaticError(sym);
3836 return sym;
3837 }
3838 }
3839 if ((env1.enclClass.sym.flags() & STATIC) != 0)
3840 staticOnly = true;
3841 env1 = env1.outer;
3842 }
3843 }
3844 return null;
3845 }
3846
3847 /**
3848 * Resolve an appropriate implicit this instance for t's container.
3849 * JLS 8.8.5.1 and 15.9.2
3850 */
3851 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
3852 return resolveImplicitThis(pos, env, t, false);
3853 }
3854
3855 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
3856 Type thisType = (t.tsym.owner.kind.matches(KindSelector.VAL_MTH)
3857 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
3858 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
3859 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym) {
3860 log.error(pos, Errors.CantRefBeforeCtorCalled("this"));
3861 }
3862 return thisType;
3863 }
3864
3865 /* ***************************************************************************
3866 * ResolveError classes, indicating error situations when accessing symbols
3867 ****************************************************************************/
3868
3869 //used by TransTypes when checking target type of synthetic cast
3870 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) {
3871 AccessError error = new AccessError(env, env.enclClass.type, type.tsym);
3872 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null);
3873 }
3874 //where
3875 private void logResolveError(ResolveError error,
3876 DiagnosticPosition pos,
3877 Symbol location,
3878 Type site,
3879 Name name,
3880 List<Type> argtypes,
3881 List<Type> typeargtypes) {
3882 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
3883 pos, location, site, name, argtypes, typeargtypes);
3884 if (d != null) {
3885 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
3886 log.report(d);
3887 }
3888 }
3889
3890 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
3891
3892 public Object methodArguments(List<Type> argtypes) {
3893 if (argtypes == null || argtypes.isEmpty()) {
3894 return noArgs;
3895 } else {
3896 ListBuffer<Object> diagArgs = new ListBuffer<>();
3897 for (Type t : argtypes) {
3898 if (t.hasTag(DEFERRED)) {
3899 diagArgs.append(((DeferredAttr.DeferredType)t).tree);
3900 } else {
3901 diagArgs.append(t);
3902 }
3903 }
3904 return diagArgs;
3905 }
3906 }
3907
3908 /** check if a type is a subtype of Serializable, if that is available.*/
3909 boolean isSerializable(Type t) {
3910 try {
3911 syms.serializableType.complete();
3912 }
3913 catch (CompletionFailure e) {
3914 return false;
3915 }
3916 return types.isSubtype(t, syms.serializableType);
3917 }
3918
3919 /**
3920 * Root class for resolution errors. Subclass of ResolveError
3921 * represent a different kinds of resolution error - as such they must
3922 * specify how they map into concrete compiler diagnostics.
3923 */
3924 abstract class ResolveError extends Symbol {
3925
3926 /** The name of the kind of error, for debugging only. */
3927 final String debugName;
3928
3929 ResolveError(Kind kind, String debugName) {
3930 super(kind, 0, null, null, null);
3931 this.debugName = debugName;
3932 }
3933
3934 @Override @DefinedBy(Api.LANGUAGE_MODEL)
3935 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
3936 throw new AssertionError();
3937 }
3938
3939 @Override
3940 public String toString() {
3941 return debugName;
3942 }
3943
3944 @Override
3945 public boolean exists() {
3946 return false;
3947 }
3948
3949 @Override
3950 public boolean isStatic() {
3951 return false;
3952 }
3953
3954 /**
3955 * Create an external representation for this erroneous symbol to be
3956 * used during attribution - by default this returns the symbol of a
3957 * brand new error type which stores the original type found
3958 * during resolution.
3959 *
3960 * @param name the name used during resolution
3961 * @param location the location from which the symbol is accessed
3962 */
3963 protected Symbol access(Name name, TypeSymbol location) {
3964 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3965 }
3966
3967 /**
3968 * Create a diagnostic representing this resolution error.
3969 *
3970 * @param dkind The kind of the diagnostic to be created (e.g error).
3971 * @param pos The position to be used for error reporting.
3972 * @param site The original type from where the selection took place.
3973 * @param name The name of the symbol to be resolved.
3974 * @param argtypes The invocation's value arguments,
3975 * if we looked for a method.
3976 * @param typeargtypes The invocation's type arguments,
3977 * if we looked for a method.
3978 */
3979 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3980 DiagnosticPosition pos,
3981 Symbol location,
3982 Type site,
3983 Name name,
3984 List<Type> argtypes,
3985 List<Type> typeargtypes);
3986 }
3987
3988 /**
3989 * This class is the root class of all resolution errors caused by
3990 * an invalid symbol being found during resolution.
3991 */
3992 abstract class InvalidSymbolError extends ResolveError {
3993
3994 /** The invalid symbol found during resolution */
3995 Symbol sym;
3996
3997 InvalidSymbolError(Kind kind, Symbol sym, String debugName) {
3998 super(kind, debugName);
3999 this.sym = sym;
4000 }
4001
4002 @Override
4003 public boolean exists() {
4004 return true;
4005 }
4006
4007 @Override
4008 public String toString() {
4009 return super.toString() + " wrongSym=" + sym;
4010 }
4011
4012 @Override
4013 public Symbol access(Name name, TypeSymbol location) {
4014 if (!sym.kind.isResolutionError() && sym.kind.matches(KindSelector.TYP))
4015 return types.createErrorType(name, location, sym.type).tsym;
4016 else
4017 return sym;
4018 }
4019 }
4020
4021 class BadRestrictedTypeError extends ResolveError {
4022 private final Name typeName;
4023 BadRestrictedTypeError(Name typeName) {
4024 super(Kind.BAD_RESTRICTED_TYPE, "bad var use");
4025 this.typeName = typeName;
4026 }
4027
4028 @Override
4029 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4030 return diags.create(dkind, log.currentSource(), pos, "illegal.ref.to.restricted.type", typeName);
4031 }
4032 }
4033
4034 /**
4035 * InvalidSymbolError error class indicating that a symbol matching a
4036 * given name does not exists in a given site.
4037 */
4038 class SymbolNotFoundError extends ResolveError {
4039
4040 SymbolNotFoundError(Kind kind) {
4041 this(kind, "symbol not found error");
4042 }
4043
4044 SymbolNotFoundError(Kind kind, String debugName) {
4045 super(kind, debugName);
4046 }
4047
4048 @Override
4049 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4050 DiagnosticPosition pos,
4051 Symbol location,
4052 Type site,
4053 Name name,
4054 List<Type> argtypes,
4055 List<Type> typeargtypes) {
4056 argtypes = argtypes == null ? List.nil() : argtypes;
4057 typeargtypes = typeargtypes == null ? List.nil() : typeargtypes;
4058 if (name == names.error)
4059 return null;
4060
4061 boolean hasLocation = false;
4062 if (location == null) {
4063 location = site.tsym;
4064 }
4065 if (!location.name.isEmpty()) {
4066 if (location.kind == PCK && !site.tsym.exists() && location.name != names.java) {
4067 return diags.create(dkind, log.currentSource(), pos,
4068 "doesnt.exist", location);
4069 }
4070 hasLocation = !location.name.equals(names._this) &&
4071 !location.name.equals(names._super);
4072 }
4073 boolean isConstructor = name == names.init;
4074 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : kind.absentKind();
4075 Name idname = isConstructor ? site.tsym.name : name;
4076 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
4077 if (hasLocation) {
4078 return diags.create(dkind, log.currentSource(), pos,
4079 errKey, kindname, idname, //symbol kindname, name
4080 typeargtypes, args(argtypes), //type parameters and arguments (if any)
4081 getLocationDiag(location, site)); //location kindname, type
4082 }
4083 else {
4084 return diags.create(dkind, log.currentSource(), pos,
4085 errKey, kindname, idname, //symbol kindname, name
4086 typeargtypes, args(argtypes)); //type parameters and arguments (if any)
4087 }
4088 }
4089 //where
4090 private Object args(List<Type> args) {
4091 return args.isEmpty() ? args : methodArguments(args);
4092 }
4093
4094 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
4095 String key = "cant.resolve";
4096 String suffix = hasLocation ? ".location" : "";
4097 switch (kindname) {
4098 case METHOD:
4099 case CONSTRUCTOR: {
4100 suffix += ".args";
4101 suffix += hasTypeArgs ? ".params" : "";
4102 }
4103 }
4104 return key + suffix;
4105 }
4106 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
4107 if (location.kind == VAR) {
4108 return diags.fragment(Fragments.Location1(kindName(location),
4109 location,
4110 location.type));
4111 } else {
4112 return diags.fragment(Fragments.Location(typeKindName(site),
4113 site,
4114 null));
4115 }
4116 }
4117 }
4118
4119 /**
4120 * InvalidSymbolError error class indicating that a given symbol
4121 * (either a method, a constructor or an operand) is not applicable
4122 * given an actual arguments/type argument list.
4123 */
4124 class InapplicableSymbolError extends ResolveError {
4125
4126 protected MethodResolutionContext resolveContext;
4127
4128 InapplicableSymbolError(MethodResolutionContext context) {
4129 this(WRONG_MTH, "inapplicable symbol error", context);
4130 }
4131
4132 protected InapplicableSymbolError(Kind kind, String debugName, MethodResolutionContext context) {
4133 super(kind, debugName);
4134 this.resolveContext = context;
4135 }
4136
4137 @Override
4138 public String toString() {
4139 return super.toString();
4140 }
4141
4142 @Override
4143 public boolean exists() {
4144 return true;
4145 }
4146
4147 @Override
4148 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4149 DiagnosticPosition pos,
4150 Symbol location,
4151 Type site,
4152 Name name,
4153 List<Type> argtypes,
4154 List<Type> typeargtypes) {
4155 if (name == names.error)
4156 return null;
4157
4158 Pair<Symbol, JCDiagnostic> c = errCandidate();
4159 if (compactMethodDiags) {
4160 JCDiagnostic simpleDiag =
4161 MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, c.snd);
4162 if (simpleDiag != null) {
4163 return simpleDiag;
4164 }
4165 }
4166 Symbol ws = c.fst.asMemberOf(site, types);
4167 return diags.create(dkind, log.currentSource(), pos,
4168 "cant.apply.symbol",
4169 kindName(ws),
4170 ws.name == names.init ? ws.owner.name : ws.name,
4171 methodArguments(ws.type.getParameterTypes()),
4172 methodArguments(argtypes),
4173 kindName(ws.owner),
4174 ws.owner.type,
4175 c.snd);
4176 }
4177
4178 @Override
4179 public Symbol access(Name name, TypeSymbol location) {
4180 Pair<Symbol, JCDiagnostic> cand = errCandidate();
4181 TypeSymbol errSymbol = types.createErrorType(name, location, cand != null ? cand.fst.type : syms.errSymbol.type).tsym;
4182 if (cand != null) {
4183 attrRecover.wrongMethodSymbolCandidate(errSymbol, cand.fst, cand.snd);
4184 }
4185 return errSymbol;
4186 }
4187
4188 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4189 Candidate bestSoFar = null;
4190 for (Candidate c : resolveContext.candidates) {
4191 if (c.isApplicable()) continue;
4192 bestSoFar = c;
4193 }
4194 Assert.checkNonNull(bestSoFar);
4195 return new Pair<>(bestSoFar.sym, bestSoFar.details);
4196 }
4197 }
4198
4199 /**
4200 * ResolveError error class indicating that a symbol (either methods, constructors or operand)
4201 * is not applicable given an actual arguments/type argument list.
4202 */
4203 class InapplicableSymbolsError extends InapplicableSymbolError {
4204
4205 InapplicableSymbolsError(MethodResolutionContext context) {
4206 super(WRONG_MTHS, "inapplicable symbols", context);
4207 }
4208
4209 @Override
4210 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4211 DiagnosticPosition pos,
4212 Symbol location,
4213 Type site,
4214 Name name,
4215 List<Type> argtypes,
4216 List<Type> typeargtypes) {
4217 Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates();
4218 Map<Symbol, JCDiagnostic> filteredCandidates = compactMethodDiags ?
4219 filterCandidates(candidatesMap) :
4220 mapCandidates();
4221 if (filteredCandidates.isEmpty()) {
4222 filteredCandidates = candidatesMap;
4223 }
4224 boolean truncatedDiag = candidatesMap.size() != filteredCandidates.size();
4225 if (filteredCandidates.size() > 1) {
4226 JCDiagnostic err = diags.create(dkind,
4227 null,
4228 truncatedDiag ?
4229 EnumSet.of(DiagnosticFlag.COMPRESSED) :
4230 EnumSet.noneOf(DiagnosticFlag.class),
4231 log.currentSource(),
4232 pos,
4233 "cant.apply.symbols",
4234 name == names.init ? KindName.CONSTRUCTOR : kind.absentKind(),
4235 name == names.init ? site.tsym.name : name,
4236 methodArguments(argtypes));
4237 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(filteredCandidates, site));
4238 } else if (filteredCandidates.size() == 1) {
4239 Map.Entry<Symbol, JCDiagnostic> _e =
4240 filteredCandidates.entrySet().iterator().next();
4241 final Pair<Symbol, JCDiagnostic> p = new Pair<>(_e.getKey(), _e.getValue());
4242 JCDiagnostic d = new InapplicableSymbolError(resolveContext) {
4243 @Override
4244 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4245 return p;
4246 }
4247 }.getDiagnostic(dkind, pos,
4248 location, site, name, argtypes, typeargtypes);
4249 if (truncatedDiag) {
4250 d.setFlag(DiagnosticFlag.COMPRESSED);
4251 }
4252 return d;
4253 } else {
4254 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
4255 location, site, name, argtypes, typeargtypes);
4256 }
4257 }
4258 //where
4259 private Map<Symbol, JCDiagnostic> mapCandidates() {
4260 MostSpecificMap candidates = new MostSpecificMap();
4261 for (Candidate c : resolveContext.candidates) {
4262 if (c.isApplicable()) continue;
4263 candidates.put(c);
4264 }
4265 return candidates;
4266 }
4267
4268 @SuppressWarnings("serial")
4269 private class MostSpecificMap extends LinkedHashMap<Symbol, JCDiagnostic> {
4270 private void put(Candidate c) {
4271 ListBuffer<Symbol> overridden = new ListBuffer<>();
4272 for (Symbol s : keySet()) {
4273 if (s == c.sym) {
4274 continue;
4275 }
4276 if (c.sym.overrides(s, (TypeSymbol)s.owner, types, false)) {
4277 overridden.add(s);
4278 } else if (s.overrides(c.sym, (TypeSymbol)c.sym.owner, types, false)) {
4279 return;
4280 }
4281 }
4282 for (Symbol s : overridden) {
4283 remove(s);
4284 }
4285 put(c.sym, c.details);
4286 }
4287 }
4288
4289 Map<Symbol, JCDiagnostic> filterCandidates(Map<Symbol, JCDiagnostic> candidatesMap) {
4290 Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<>();
4291 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
4292 JCDiagnostic d = _entry.getValue();
4293 if (!new Template(MethodCheckDiag.ARITY_MISMATCH.regex()).matches(d)) {
4294 candidates.put(_entry.getKey(), d);
4295 }
4296 }
4297 return candidates;
4298 }
4299
4300 private List<JCDiagnostic> candidateDetails(Map<Symbol, JCDiagnostic> candidatesMap, Type site) {
4301 List<JCDiagnostic> details = List.nil();
4302 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
4303 Symbol sym = _entry.getKey();
4304 JCDiagnostic detailDiag =
4305 diags.fragment(Fragments.InapplicableMethod(Kinds.kindName(sym),
4306 sym.location(site, types),
4307 sym.asMemberOf(site, types),
4308 _entry.getValue()));
4309 details = details.prepend(detailDiag);
4310 }
4311 //typically members are visited in reverse order (see Scope)
4312 //so we need to reverse the candidate list so that candidates
4313 //conform to source order
4314 return details;
4315 }
4316
4317 @Override
4318 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4319 Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates();
4320 Map<Symbol, JCDiagnostic> filteredCandidates = filterCandidates(candidatesMap);
4321 if (filteredCandidates.size() == 1) {
4322 return Pair.of(filteredCandidates.keySet().iterator().next(),
4323 filteredCandidates.values().iterator().next());
4324 }
4325 return null;
4326 }
4327 }
4328
4329 /**
4330 * DiamondError error class indicating that a constructor symbol is not applicable
4331 * given an actual arguments/type argument list using diamond inference.
4332 */
4333 class DiamondError extends InapplicableSymbolError {
4334
4335 Symbol sym;
4336
4337 public DiamondError(Symbol sym, MethodResolutionContext context) {
4338 super(sym.kind, "diamondError", context);
4339 this.sym = sym;
4340 }
4341
4342 JCDiagnostic getDetails() {
4343 return (sym.kind == WRONG_MTH) ?
4344 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd :
4345 null;
4346 }
4347
4348 @Override
4349 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
4350 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4351 JCDiagnostic details = getDetails();
4352 if (details != null && compactMethodDiags) {
4353 JCDiagnostic simpleDiag =
4354 MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, details);
4355 if (simpleDiag != null) {
4356 return simpleDiag;
4357 }
4358 }
4359 String key = details == null ?
4360 "cant.apply.diamond" :
4361 "cant.apply.diamond.1";
4362 return diags.create(dkind, log.currentSource(), pos, key,
4363 Fragments.Diamond(site.tsym), details);
4364 }
4365 }
4366
4367 /**
4368 * An InvalidSymbolError error class indicating that a symbol is not
4369 * accessible from a given site
4370 */
4371 class AccessError extends InvalidSymbolError {
4372
4373 private Env<AttrContext> env;
4374 private Type site;
4375
4376 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
4377 super(HIDDEN, sym, "access error");
4378 this.env = env;
4379 this.site = site;
4380 }
4381
4382 @Override
4383 public boolean exists() {
4384 return false;
4385 }
4386
4387 @Override
4388 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4389 DiagnosticPosition pos,
4390 Symbol location,
4391 Type site,
4392 Name name,
4393 List<Type> argtypes,
4394 List<Type> typeargtypes) {
4395 if (sym.name == names.init && sym.owner != site.tsym) {
4396 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
4397 pos, location, site, name, argtypes, typeargtypes);
4398 }
4399 else if ((sym.flags() & PUBLIC) != 0
4400 || (env != null && this.site != null
4401 && !isAccessible(env, this.site))) {
4402 if (sym.owner.kind == PCK) {
4403 return diags.create(dkind, log.currentSource(),
4404 pos, "not.def.access.package.cant.access",
4405 sym, sym.location(), inaccessiblePackageReason(env, sym.packge()));
4406 } else if ( sym.packge() != syms.rootPackage
4407 && !symbolPackageVisible(env, sym)) {
4408 return diags.create(dkind, log.currentSource(),
4409 pos, "not.def.access.class.intf.cant.access.reason",
4410 sym, sym.location(), sym.location().packge(),
4411 inaccessiblePackageReason(env, sym.packge()));
4412 } else {
4413 return diags.create(dkind, log.currentSource(),
4414 pos, "not.def.access.class.intf.cant.access",
4415 sym, sym.location());
4416 }
4417 }
4418 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
4419 return diags.create(dkind, log.currentSource(),
4420 pos, "report.access", sym,
4421 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
4422 sym.location());
4423 }
4424 else {
4425 return diags.create(dkind, log.currentSource(),
4426 pos, "not.def.public.cant.access", sym, sym.location());
4427 }
4428 }
4429
4430 private String toString(Type type) {
4431 StringBuilder sb = new StringBuilder();
4432 sb.append(type);
4433 if (type != null) {
4434 sb.append("[tsym:").append(type.tsym);
4435 if (type.tsym != null)
4436 sb.append("packge:").append(type.tsym.packge());
4437 sb.append("]");
4438 }
4439 return sb.toString();
4440 }
4441 }
4442
4443 class InvisibleSymbolError extends InvalidSymbolError {
4444
4445 private final Env<AttrContext> env;
4446 private final boolean suppressError;
4447
4448 InvisibleSymbolError(Env<AttrContext> env, boolean suppressError, Symbol sym) {
4449 super(HIDDEN, sym, "invisible class error");
4450 this.env = env;
4451 this.suppressError = suppressError;
4452 this.name = sym.name;
4453 }
4454
4455 @Override
4456 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4457 DiagnosticPosition pos,
4458 Symbol location,
4459 Type site,
4460 Name name,
4461 List<Type> argtypes,
4462 List<Type> typeargtypes) {
4463 if (suppressError)
4464 return null;
4465
4466 if (sym.kind == PCK) {
4467 JCDiagnostic details = inaccessiblePackageReason(env, sym.packge());
4468 return diags.create(dkind, log.currentSource(),
4469 pos, "package.not.visible", sym, details);
4470 }
4471
4472 JCDiagnostic details = inaccessiblePackageReason(env, sym.packge());
4473
4474 if (pos.getTree() != null) {
4475 Symbol o = sym;
4476 JCTree tree = pos.getTree();
4477
4478 while (o.kind != PCK && tree.hasTag(SELECT)) {
4479 o = o.owner;
4480 tree = ((JCFieldAccess) tree).selected;
4481 }
4482
4483 if (o.kind == PCK) {
4484 pos = tree.pos();
4485
4486 return diags.create(dkind, log.currentSource(),
4487 pos, "package.not.visible", o, details);
4488 }
4489 }
4490
4491 return diags.create(dkind, log.currentSource(),
4492 pos, "not.def.access.package.cant.access", sym, sym.packge(), details);
4493 }
4494 }
4495
4496 JCDiagnostic inaccessiblePackageReason(Env<AttrContext> env, PackageSymbol sym) {
4497 //no dependency:
4498 if (!env.toplevel.modle.readModules.contains(sym.modle)) {
4499 //does not read:
4500 if (sym.modle != syms.unnamedModule) {
4501 if (env.toplevel.modle != syms.unnamedModule) {
4502 return diags.fragment(Fragments.NotDefAccessDoesNotRead(env.toplevel.modle,
4503 sym,
4504 sym.modle));
4505 } else {
4506 return diags.fragment(Fragments.NotDefAccessDoesNotReadFromUnnamed(sym,
4507 sym.modle));
4508 }
4509 } else {
4510 return diags.fragment(Fragments.NotDefAccessDoesNotReadUnnamed(sym,
4511 env.toplevel.modle));
4512 }
4513 } else {
4514 if (sym.packge().modle.exports.stream().anyMatch(e -> e.packge == sym)) {
4515 //not exported to this module:
4516 if (env.toplevel.modle != syms.unnamedModule) {
4517 return diags.fragment(Fragments.NotDefAccessNotExportedToModule(sym,
4518 sym.modle,
4519 env.toplevel.modle));
4520 } else {
4521 return diags.fragment(Fragments.NotDefAccessNotExportedToModuleFromUnnamed(sym,
4522 sym.modle));
4523 }
4524 } else {
4525 //not exported:
4526 if (env.toplevel.modle != syms.unnamedModule) {
4527 return diags.fragment(Fragments.NotDefAccessNotExported(sym,
4528 sym.modle));
4529 } else {
4530 return diags.fragment(Fragments.NotDefAccessNotExportedFromUnnamed(sym,
4531 sym.modle));
4532 }
4533 }
4534 }
4535 }
4536
4537 /**
4538 * InvalidSymbolError error class indicating that an instance member
4539 * has erroneously been accessed from a static context.
4540 */
4541 class StaticError extends InvalidSymbolError {
4542
4543 StaticError(Symbol sym) {
4544 super(STATICERR, sym, "static error");
4545 }
4546
4547 @Override
4548 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4549 DiagnosticPosition pos,
4550 Symbol location,
4551 Type site,
4552 Name name,
4553 List<Type> argtypes,
4554 List<Type> typeargtypes) {
4555 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS))
4556 ? types.erasure(sym.type).tsym
4557 : sym);
4558 return diags.create(dkind, log.currentSource(), pos,
4559 "non-static.cant.be.ref", kindName(sym), errSym);
4560 }
4561 }
4562
4563 /**
4564 * InvalidSymbolError error class indicating that a pair of symbols
4565 * (either methods, constructors or operands) are ambiguous
4566 * given an actual arguments/type argument list.
4567 */
4568 class AmbiguityError extends ResolveError {
4569
4570 /** The other maximally specific symbol */
4571 List<Symbol> ambiguousSyms = List.nil();
4572
4573 @Override
4574 public boolean exists() {
4575 return true;
4576 }
4577
4578 AmbiguityError(Symbol sym1, Symbol sym2) {
4579 super(AMBIGUOUS, "ambiguity error");
4580 ambiguousSyms = flatten(sym2).appendList(flatten(sym1));
4581 }
4582
4583 private List<Symbol> flatten(Symbol sym) {
4584 if (sym.kind == AMBIGUOUS) {
4585 return ((AmbiguityError)sym.baseSymbol()).ambiguousSyms;
4586 } else {
4587 return List.of(sym);
4588 }
4589 }
4590
4591 AmbiguityError addAmbiguousSymbol(Symbol s) {
4592 ambiguousSyms = ambiguousSyms.prepend(s);
4593 return this;
4594 }
4595
4596 @Override
4597 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4598 DiagnosticPosition pos,
4599 Symbol location,
4600 Type site,
4601 Name name,
4602 List<Type> argtypes,
4603 List<Type> typeargtypes) {
4604 List<Symbol> diagSyms = ambiguousSyms.reverse();
4605 Symbol s1 = diagSyms.head;
4606 Symbol s2 = diagSyms.tail.head;
4607 Name sname = s1.name;
4608 if (sname == names.init) sname = s1.owner.name;
4609 return diags.create(dkind, log.currentSource(),
4610 pos, "ref.ambiguous", sname,
4611 kindName(s1),
4612 s1,
4613 s1.location(site, types),
4614 kindName(s2),
4615 s2,
4616 s2.location(site, types));
4617 }
4618
4619 /**
4620 * If multiple applicable methods are found during overload and none of them
4621 * is more specific than the others, attempt to merge their signatures.
4622 */
4623 Symbol mergeAbstracts(Type site) {
4624 List<Symbol> ambiguousInOrder = ambiguousSyms.reverse();
4625 return types.mergeAbstracts(ambiguousInOrder, site, true).orElse(this);
4626 }
4627
4628 @Override
4629 protected Symbol access(Name name, TypeSymbol location) {
4630 Symbol firstAmbiguity = ambiguousSyms.last();
4631 return firstAmbiguity.kind == TYP ?
4632 types.createErrorType(name, location, firstAmbiguity.type).tsym :
4633 firstAmbiguity;
4634 }
4635 }
4636
4637 class BadVarargsMethod extends ResolveError {
4638
4639 ResolveError delegatedError;
4640
4641 BadVarargsMethod(ResolveError delegatedError) {
4642 super(delegatedError.kind, "badVarargs");
4643 this.delegatedError = delegatedError;
4644 }
4645
4646 @Override
4647 public Symbol baseSymbol() {
4648 return delegatedError.baseSymbol();
4649 }
4650
4651 @Override
4652 protected Symbol access(Name name, TypeSymbol location) {
4653 return delegatedError.access(name, location);
4654 }
4655
4656 @Override
4657 public boolean exists() {
4658 return true;
4659 }
4660
4661 @Override
4662 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4663 return delegatedError.getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes);
4664 }
4665 }
4666
4667 /**
4668 * BadMethodReferenceError error class indicating that a method reference symbol has been found,
4669 * but with the wrong staticness.
4670 */
4671 class BadMethodReferenceError extends StaticError {
4672
4673 boolean unboundLookup;
4674
4675 public BadMethodReferenceError(Symbol sym, boolean unboundLookup) {
4676 super(sym);
4677 this.unboundLookup = unboundLookup;
4678 }
4679
4680 @Override
4681 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4682 final String key;
4683 if (!unboundLookup) {
4684 key = "bad.static.method.in.bound.lookup";
4685 } else if (sym.isStatic()) {
4686 key = "bad.static.method.in.unbound.lookup";
4687 } else {
4688 key = "bad.instance.method.in.unbound.lookup";
4689 }
4690 return sym.kind.isResolutionError() ?
4691 ((ResolveError)sym).getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes) :
4692 diags.create(dkind, log.currentSource(), pos, key, Kinds.kindName(sym), sym);
4693 }
4694 }
4695
4696 /**
4697 * BadConstructorReferenceError error class indicating that a constructor reference symbol has been found,
4698 * but pointing to a class for which an enclosing instance is not available.
4699 */
4700 class BadConstructorReferenceError extends InvalidSymbolError {
4701
4702 public BadConstructorReferenceError(Symbol sym) {
4703 super(MISSING_ENCL, sym, "BadConstructorReferenceError");
4704 }
4705
4706 @Override
4707 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4708 return diags.create(dkind, log.currentSource(), pos,
4709 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType());
4710 }
4711 }
4712
4713 class BadClassFileError extends InvalidSymbolError {
4714
4715 private final CompletionFailure ex;
4716
4717 public BadClassFileError(CompletionFailure ex) {
4718 super(HIDDEN, ex.sym, "BadClassFileError");
4719 this.name = sym.name;
4720 this.ex = ex;
4721 }
4722
4723 @Override
4724 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4725 JCDiagnostic d = diags.create(dkind, log.currentSource(), pos,
4726 "cant.access", ex.sym, ex.getDetailValue());
4727
4728 d.setFlag(DiagnosticFlag.NON_DEFERRABLE);
4729 return d;
4730 }
4731
4732 }
4733
4734 /**
4735 * Helper class for method resolution diagnostic simplification.
4736 * Certain resolution diagnostic are rewritten as simpler diagnostic
4737 * where the enclosing resolution diagnostic (i.e. 'inapplicable method')
4738 * is stripped away, as it doesn't carry additional info. The logic
4739 * for matching a given diagnostic is given in terms of a template
4740 * hierarchy: a diagnostic template can be specified programmatically,
4741 * so that only certain diagnostics are matched. Each templete is then
4742 * associated with a rewriter object that carries out the task of rewtiting
4743 * the diagnostic to a simpler one.
4744 */
4745 static class MethodResolutionDiagHelper {
4746
4747 /**
4748 * A diagnostic rewriter transforms a method resolution diagnostic
4749 * into a simpler one
4750 */
4751 interface DiagnosticRewriter {
4752 JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
4753 DiagnosticPosition preferredPos, DiagnosticSource preferredSource,
4754 DiagnosticType preferredKind, JCDiagnostic d);
4755 }
4756
4757 /**
4758 * A diagnostic template is made up of two ingredients: (i) a regular
4759 * expression for matching a diagnostic key and (ii) a list of sub-templates
4760 * for matching diagnostic arguments.
4761 */
4762 static class Template {
4763
4764 /** regex used to match diag key */
4765 String regex;
4766
4767 /** templates used to match diagnostic args */
4768 Template[] subTemplates;
4769
4770 Template(String key, Template... subTemplates) {
4771 this.regex = key;
4772 this.subTemplates = subTemplates;
4773 }
4774
4775 /**
4776 * Returns true if the regex matches the diagnostic key and if
4777 * all diagnostic arguments are matches by corresponding sub-templates.
4778 */
4779 boolean matches(Object o) {
4780 JCDiagnostic d = (JCDiagnostic)o;
4781 Object[] args = d.getArgs();
4782 if (!d.getCode().matches(regex) ||
4783 subTemplates.length != d.getArgs().length) {
4784 return false;
4785 }
4786 for (int i = 0; i < args.length ; i++) {
4787 if (!subTemplates[i].matches(args[i])) {
4788 return false;
4789 }
4790 }
4791 return true;
4792 }
4793 }
4794
4795 /**
4796 * Common rewriter for all argument mismatch simplifications.
4797 */
4798 static class ArgMismatchRewriter implements DiagnosticRewriter {
4799
4800 /** the index of the subdiagnostic to be used as primary. */
4801 int causeIndex;
4802
4803 public ArgMismatchRewriter(int causeIndex) {
4804 this.causeIndex = causeIndex;
4805 }
4806
4807 @Override
4808 public JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
4809 DiagnosticPosition preferredPos, DiagnosticSource preferredSource,
4810 DiagnosticType preferredKind, JCDiagnostic d) {
4811 JCDiagnostic cause = (JCDiagnostic)d.getArgs()[causeIndex];
4812 DiagnosticPosition pos = d.getDiagnosticPosition();
4813 if (pos == null) {
4814 pos = preferredPos;
4815 }
4816 return diags.create(preferredKind, preferredSource, pos,
4817 "prob.found.req", cause);
4818 }
4819 }
4820
4821 /** a dummy template that match any diagnostic argument */
4822 static final Template skip = new Template("") {
4823 @Override
4824 boolean matches(Object d) {
4825 return true;
4826 }
4827 };
4828
4829 /** template for matching inference-free arguments mismatch failures */
4830 static final Template argMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip);
4831
4832 /** template for matching inference related arguments mismatch failures */
4833 static final Template inferArgMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip, skip) {
4834 @Override
4835 boolean matches(Object o) {
4836 if (!super.matches(o)) {
4837 return false;
4838 }
4839 JCDiagnostic d = (JCDiagnostic)o;
4840 @SuppressWarnings("unchecked")
4841 List<Type> tvars = (List<Type>)d.getArgs()[0];
4842 return !containsAny(d, tvars);
4843 }
4844
4845 BiPredicate<Object, List<Type>> containsPredicate = (o, ts) -> {
4846 if (o instanceof Type type) {
4847 return type.containsAny(ts);
4848 } else if (o instanceof JCDiagnostic diagnostic) {
4849 return containsAny(diagnostic, ts);
4850 } else {
4851 return false;
4852 }
4853 };
4854
4855 boolean containsAny(JCDiagnostic d, List<Type> ts) {
4856 return Stream.of(d.getArgs())
4857 .anyMatch(o -> containsPredicate.test(o, ts));
4858 }
4859 };
4860
4861 /** rewriter map used for method resolution simplification */
4862 static final Map<Template, DiagnosticRewriter> rewriters = new LinkedHashMap<>();
4863
4864 static {
4865 rewriters.put(argMismatchTemplate, new ArgMismatchRewriter(0));
4866 rewriters.put(inferArgMismatchTemplate, new ArgMismatchRewriter(1));
4867 }
4868
4869 /**
4870 * Main entry point for diagnostic rewriting - given a diagnostic, see if any templates matches it,
4871 * and rewrite it accordingly.
4872 */
4873 static JCDiagnostic rewrite(JCDiagnostic.Factory diags, DiagnosticPosition pos, DiagnosticSource source,
4874 DiagnosticType dkind, JCDiagnostic d) {
4875 for (Map.Entry<Template, DiagnosticRewriter> _entry : rewriters.entrySet()) {
4876 if (_entry.getKey().matches(d)) {
4877 JCDiagnostic simpleDiag =
4878 _entry.getValue().rewriteDiagnostic(diags, pos, source, dkind, d);
4879 simpleDiag.setFlag(DiagnosticFlag.COMPRESSED);
4880 return simpleDiag;
4881 }
4882 }
4883 return null;
4884 }
4885 }
4886
4887 enum MethodResolutionPhase {
4888 BASIC(false, false),
4889 BOX(true, false),
4890 VARARITY(true, true) {
4891 @Override
4892 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) {
4893 //Check invariants (see {@code LookupHelper.shouldStop})
4894 Assert.check(bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS);
4895 if (!sym.kind.isResolutionError()) {
4896 //varargs resolution successful
4897 return sym;
4898 } else {
4899 //pick best error
4900 switch (bestSoFar.kind) {
4901 case WRONG_MTH:
4902 case WRONG_MTHS:
4903 //Override previous errors if they were caused by argument mismatch.
4904 //This generally means preferring current symbols - but we need to pay
4905 //attention to the fact that the varargs lookup returns 'less' candidates
4906 //than the previous rounds, and adjust that accordingly.
4907 switch (sym.kind) {
4908 case WRONG_MTH:
4909 //if the previous round matched more than one method, return that
4910 //result instead
4911 return bestSoFar.kind == WRONG_MTHS ?
4912 bestSoFar : sym;
4913 case ABSENT_MTH:
4914 //do not override erroneous symbol if the arity lookup did not
4915 //match any method
4916 return bestSoFar;
4917 case WRONG_MTHS:
4918 default:
4919 //safe to override
4920 return sym;
4921 }
4922 default:
4923 //otherwise, return first error
4924 return bestSoFar;
4925 }
4926 }
4927 }
4928 };
4929
4930 final boolean isBoxingRequired;
4931 final boolean isVarargsRequired;
4932
4933 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
4934 this.isBoxingRequired = isBoxingRequired;
4935 this.isVarargsRequired = isVarargsRequired;
4936 }
4937
4938 public boolean isBoxingRequired() {
4939 return isBoxingRequired;
4940 }
4941
4942 public boolean isVarargsRequired() {
4943 return isVarargsRequired;
4944 }
4945
4946 public Symbol mergeResults(Symbol prev, Symbol sym) {
4947 return sym;
4948 }
4949 }
4950
4951 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
4952
4953 /**
4954 * A resolution context is used to keep track of intermediate results of
4955 * overload resolution, such as list of method that are not applicable
4956 * (used to generate more precise diagnostics) and so on. Resolution contexts
4957 * can be nested - this means that when each overload resolution routine should
4958 * work within the resolution context it created.
4959 */
4960 class MethodResolutionContext {
4961
4962 private List<Candidate> candidates = List.nil();
4963
4964 MethodResolutionPhase step = null;
4965
4966 MethodCheck methodCheck = resolveMethodCheck;
4967
4968 private boolean internalResolution = false;
4969 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE;
4970
4971 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) {
4972 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null);
4973 candidates = candidates.append(c);
4974 }
4975
4976 void addApplicableCandidate(Symbol sym, Type mtype) {
4977 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype);
4978 candidates = candidates.append(c);
4979 }
4980
4981 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext, ResultInfo pendingResult, Warner warn) {
4982 DeferredAttrContext parent = (pendingResult == null)
4983 ? deferredAttr.emptyDeferredAttrContext
4984 : pendingResult.checkContext.deferredAttrContext();
4985 return deferredAttr.new DeferredAttrContext(attrMode, sym, step,
4986 inferenceContext, parent, warn);
4987 }
4988
4989 /**
4990 * This class represents an overload resolution candidate. There are two
4991 * kinds of candidates: applicable methods and inapplicable methods;
4992 * applicable methods have a pointer to the instantiated method type,
4993 * while inapplicable candidates contain further details about the
4994 * reason why the method has been considered inapplicable.
4995 */
4996 @SuppressWarnings("overrides")
4997 class Candidate {
4998
4999 final MethodResolutionPhase step;
5000 final Symbol sym;
5001 final JCDiagnostic details;
5002 final Type mtype;
5003
5004 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) {
5005 this.step = step;
5006 this.sym = sym;
5007 this.details = details;
5008 this.mtype = mtype;
5009 }
5010
5011 boolean isApplicable() {
5012 return mtype != null;
5013 }
5014 }
5015
5016 DeferredAttr.AttrMode attrMode() {
5017 return attrMode;
5018 }
5019
5020 boolean internal() {
5021 return internalResolution;
5022 }
5023 }
5024
5025 MethodResolutionContext currentResolutionContext = null;
5026 }