1 /*
2 * Copyright (c) 1999, 2023, 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
57 import java.util.Arrays;
58 import java.util.Collection;
59 import java.util.EnumSet;
60 import java.util.HashSet;
61 import java.util.Iterator;
62 import java.util.LinkedHashMap;
63 import java.util.Map;
64 import java.util.Set;
65 import java.util.function.BiFunction;
66 import java.util.function.BiPredicate;
67 import java.util.function.Function;
68 import java.util.function.Predicate;
69 import java.util.function.UnaryOperator;
70 import java.util.stream.Stream;
71 import java.util.stream.StreamSupport;
72
73 import javax.lang.model.element.ElementVisitor;
74
75 import static com.sun.tools.javac.code.Flags.*;
76 import static com.sun.tools.javac.code.Flags.BLOCK;
77 import static com.sun.tools.javac.code.Flags.STATIC;
78 import static com.sun.tools.javac.code.Kinds.*;
79 import static com.sun.tools.javac.code.Kinds.Kind.*;
80 import static com.sun.tools.javac.code.TypeTag.*;
81 import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*;
82 import static com.sun.tools.javac.tree.JCTree.Tag.*;
83 import static com.sun.tools.javac.util.Iterators.createCompoundIterator;
84
85 /** Helper class for name resolution, used mostly by the attribution phase.
86 *
87 * <p><b>This is NOT part of any supported API.
88 * If you write code that depends on this, you do so at your own risk.
89 * This code and its internal interfaces are subject to change or
90 * deletion without notice.</b>
91 */
92 public class Resolve {
93 protected static final Context.Key<Resolve> resolveKey = new Context.Key<>();
94
95 Names names;
96 Log log;
97 Symtab syms;
98 Attr attr;
99 AttrRecover attrRecover;
100 DeferredAttr deferredAttr;
101 Check chk;
102 Infer infer;
103 ClassFinder finder;
104 ModuleFinder moduleFinder;
105 Types types;
106 JCDiagnostic.Factory diags;
107 public final boolean allowModules;
108 public final boolean allowRecords;
109 private final boolean compactMethodDiags;
110 private final boolean allowLocalVariableTypeInference;
111 private final boolean allowYieldStatement;
112 final EnumSet<VerboseResolutionMode> verboseResolutionMode;
113 final boolean dumpMethodReferenceSearchResults;
114
115 WriteableScope polymorphicSignatureScope;
116
117 @SuppressWarnings("this-escape")
118 protected Resolve(Context context) {
119 context.put(resolveKey, this);
120 syms = Symtab.instance(context);
121
122 varNotFound = new SymbolNotFoundError(ABSENT_VAR);
123 methodNotFound = new SymbolNotFoundError(ABSENT_MTH);
124 typeNotFound = new SymbolNotFoundError(ABSENT_TYP);
125 referenceNotFound = ReferenceLookupResult.error(methodNotFound);
126
127 names = Names.instance(context);
128 log = Log.instance(context);
129 attr = Attr.instance(context);
130 attrRecover = AttrRecover.instance(context);
131 deferredAttr = DeferredAttr.instance(context);
132 chk = Check.instance(context);
133 infer = Infer.instance(context);
134 finder = ClassFinder.instance(context);
135 moduleFinder = ModuleFinder.instance(context);
136 types = Types.instance(context);
137 diags = JCDiagnostic.Factory.instance(context);
138 Preview preview = Preview.instance(context);
139 Source source = Source.instance(context);
140 Options options = Options.instance(context);
141 compactMethodDiags = options.isSet(Option.XDIAGS, "compact") ||
142 options.isUnset(Option.XDIAGS) && options.isUnset("rawDiagnostics");
143 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
144 Target target = Target.instance(context);
145 allowLocalVariableTypeInference = Feature.LOCAL_VARIABLE_TYPE_INFERENCE.allowedInSource(source);
146 allowYieldStatement = Feature.SWITCH_EXPRESSION.allowedInSource(source);
147 polymorphicSignatureScope = WriteableScope.create(syms.noSymbol);
148 allowModules = Feature.MODULES.allowedInSource(source);
149 allowRecords = Feature.RECORDS.allowedInSource(source);
150 dumpMethodReferenceSearchResults = options.isSet("debug.dumpMethodReferenceSearchResults");
151 }
152
153 /** error symbols, which are returned when resolution fails
154 */
155 private final SymbolNotFoundError varNotFound;
156 private final SymbolNotFoundError methodNotFound;
157 private final SymbolNotFoundError typeNotFound;
158
159 /** empty reference lookup result */
160 private final ReferenceLookupResult referenceNotFound;
161
162 public static Resolve instance(Context context) {
163 Resolve instance = context.get(resolveKey);
164 if (instance == null)
165 instance = new Resolve(context);
166 return instance;
167 }
168
169 private static Symbol bestOf(Symbol s1,
170 Symbol s2) {
171 return s1.kind.betterThan(s2.kind) ? s1 : s2;
172 }
173
174 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support">
175 enum VerboseResolutionMode {
176 SUCCESS("success"),
177 FAILURE("failure"),
178 APPLICABLE("applicable"),
179 INAPPLICABLE("inapplicable"),
180 DEFERRED_INST("deferred-inference"),
181 PREDEF("predef"),
182 OBJECT_INIT("object-init"),
183 INTERNAL("internal");
184
185 final String opt;
186
187 private VerboseResolutionMode(String opt) {
188 this.opt = opt;
189 }
190
191 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) {
192 String s = opts.get("debug.verboseResolution");
193 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class);
194 if (s == null) return res;
195 if (s.contains("all")) {
196 res = EnumSet.allOf(VerboseResolutionMode.class);
197 }
198 Collection<String> args = Arrays.asList(s.split(","));
199 for (VerboseResolutionMode mode : values()) {
200 if (args.contains(mode.opt)) {
201 res.add(mode);
202 } else if (args.contains("-" + mode.opt)) {
203 res.remove(mode);
204 }
205 }
206 return res;
207 }
208 }
209
210 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site,
211 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) {
212 boolean success = !bestSoFar.kind.isResolutionError();
213
214 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) {
215 return;
216 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) {
217 return;
218 }
219
220 if (bestSoFar.name == names.init &&
221 bestSoFar.owner == syms.objectType.tsym &&
222 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) {
223 return; //skip diags for Object constructor resolution
224 } else if (site == syms.predefClass.type &&
225 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) {
226 return; //skip spurious diags for predef symbols (i.e. operators)
227 } else if (currentResolutionContext.internalResolution &&
228 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) {
229 return;
230 }
231
232 int pos = 0;
233 int mostSpecificPos = -1;
234 ListBuffer<JCDiagnostic> subDiags = new ListBuffer<>();
235 for (Candidate c : currentResolutionContext.candidates) {
236 if (currentResolutionContext.step != c.step ||
237 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) ||
238 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) {
239 continue;
240 } else {
241 subDiags.append(c.isApplicable() ?
242 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) :
243 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details));
244 if (c.sym == bestSoFar)
245 mostSpecificPos = pos;
246 pos++;
247 }
248 }
249 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1";
250 List<Type> argtypes2 = argtypes.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step));
251 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name,
252 site.tsym, mostSpecificPos, currentResolutionContext.step,
253 methodArguments(argtypes2),
254 methodArguments(typeargtypes));
255 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
256 log.report(d);
257 }
258
259 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) {
260 JCDiagnostic subDiag = null;
261 if (sym.type.hasTag(FORALL)) {
262 subDiag = diags.fragment(Fragments.PartialInstSig(inst));
263 }
264
265 String key = subDiag == null ?
266 "applicable.method.found" :
267 "applicable.method.found.1";
268
269 return diags.fragment(key, pos, sym, subDiag);
270 }
271
272 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) {
273 return diags.fragment(Fragments.NotApplicableMethodFound(pos, sym, subDiag));
274 }
275 // </editor-fold>
276
277 /* ************************************************************************
278 * Identifier resolution
279 *************************************************************************/
280
281 /** An environment is "static" if its static level is greater than
282 * the one of its outer environment
283 */
284 protected static boolean isStatic(Env<AttrContext> env) {
285 return env.outer != null && env.info.staticLevel > env.outer.info.staticLevel;
286 }
287
288 /** An environment is an "initializer" if it is a constructor or
289 * an instance initializer.
290 */
291 static boolean isInitializer(Env<AttrContext> env) {
292 Symbol owner = env.info.scope.owner;
293 return owner.isConstructor() ||
294 owner.owner.kind == TYP &&
295 (owner.kind == VAR ||
296 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
297 (owner.flags() & STATIC) == 0;
298 }
299
300 /** Is class accessible in given environment?
301 * @param env The current environment.
302 * @param c The class whose accessibility is checked.
303 */
304 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
305 return isAccessible(env, c, false);
306 }
307
308 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) {
309
310 /* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor
311 to refer to an inaccessible type
312 */
313 if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0)
314 return true;
315
316 if (env.info.visitingServiceImplementation &&
317 env.toplevel.modle == c.packge().modle) {
318 return true;
319 }
320
321 boolean isAccessible = false;
322 switch ((short)(c.flags() & AccessFlags)) {
323 case PRIVATE:
324 isAccessible =
325 env.enclClass.sym.outermostClass() ==
326 c.owner.outermostClass();
327 break;
328 case 0:
329 isAccessible =
330 env.toplevel.packge == c.owner // fast special case
331 ||
332 env.toplevel.packge == c.packge();
333 break;
334 default: // error recovery
335 isAccessible = true;
336 break;
337 case PUBLIC:
338 if (allowModules) {
339 ModuleSymbol currModule = env.toplevel.modle;
340 currModule.complete();
341 PackageSymbol p = c.packge();
342 isAccessible =
343 currModule == p.modle ||
344 currModule.visiblePackages.get(p.fullname) == p ||
345 p == syms.rootPackage ||
346 (p.modle == syms.unnamedModule && currModule.readModules.contains(p.modle));
347 } else {
348 isAccessible = true;
349 }
350 break;
351 case PROTECTED:
352 isAccessible =
353 env.toplevel.packge == c.owner // fast special case
354 ||
355 env.toplevel.packge == c.packge()
356 ||
357 isInnerSubClass(env.enclClass.sym, c.owner)
358 ||
359 env.info.allowProtectedAccess;
360 break;
361 }
362 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
363 isAccessible :
364 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
365 }
366 //where
367 /** Is given class a subclass of given base class, or an inner class
368 * of a subclass?
369 * Return null if no such class exists.
370 * @param c The class which is the subclass or is contained in it.
371 * @param base The base class
372 */
373 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
374 while (c != null && !c.isSubClass(base, types)) {
375 c = c.owner.enclClass();
376 }
377 return c != null;
378 }
379
380 boolean isAccessible(Env<AttrContext> env, Type t) {
381 return isAccessible(env, t, false);
382 }
383
384 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) {
385 if (t.hasTag(ARRAY)) {
386 return isAccessible(env, types.cvarUpperBound(types.elemtype(t)));
387 } else if (t.isUnion()) {
388 return StreamSupport.stream(((UnionClassType) t).getAlternativeTypes().spliterator(), false)
389 .allMatch(alternative -> isAccessible(env, alternative.tsym, checkInner));
390 } else {
391 return isAccessible(env, t.tsym, checkInner);
392 }
393 }
394
395 /** Is symbol accessible as a member of given type in given environment?
396 * @param env The current environment.
397 * @param site The type of which the tested symbol is regarded
398 * as a member.
399 * @param sym The symbol.
400 */
401 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
402 return isAccessible(env, site, sym, false);
403 }
404 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) {
405 if (sym.name == names.init && sym.owner != site.tsym) return false;
406
407 /* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor
408 to refer to an inaccessible type
409 */
410 if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0)
411 return true;
412
413 if (env.info.visitingServiceImplementation &&
414 env.toplevel.modle == sym.packge().modle) {
415 return true;
416 }
417
418 switch ((short)(sym.flags() & AccessFlags)) {
419 case PRIVATE:
420 return
421 (env.enclClass.sym == sym.owner // fast special case
422 ||
423 env.enclClass.sym.outermostClass() ==
424 sym.owner.outermostClass())
425 &&
426 sym.isInheritedIn(site.tsym, types);
427 case 0:
428 return
429 (env.toplevel.packge == sym.owner.owner // fast special case
430 ||
431 env.toplevel.packge == sym.packge())
432 &&
433 isAccessible(env, site, checkInner)
434 &&
435 sym.isInheritedIn(site.tsym, types)
436 &&
437 notOverriddenIn(site, sym);
438 case PROTECTED:
439 return
440 (env.toplevel.packge == sym.owner.owner // fast special case
441 ||
442 env.toplevel.packge == sym.packge()
443 ||
444 isProtectedAccessible(sym, env.enclClass.sym, site)
445 ||
446 // OK to select instance method or field from 'super' or type name
447 // (but type names should be disallowed elsewhere!)
448 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
449 &&
450 isAccessible(env, site, checkInner)
451 &&
452 notOverriddenIn(site, sym);
453 default: // this case includes erroneous combinations as well
454 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
455 }
456 }
457 //where
458 /* `sym' is accessible only if not overridden by
459 * another symbol which is a member of `site'
460 * (because, if it is overridden, `sym' is not strictly
461 * speaking a member of `site'). A polymorphic signature method
462 * cannot be overridden (e.g. MH.invokeExact(Object[])).
463 */
464 private boolean notOverriddenIn(Type site, Symbol sym) {
465 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
466 return true;
467 else {
468 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
469 return (s2 == null || s2 == sym || sym.owner == s2.owner || (sym.owner.isInterface() && s2.owner == syms.objectType.tsym) ||
470 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
471 }
472 }
473 //where
474 /** Is given protected symbol accessible if it is selected from given site
475 * and the selection takes place in given class?
476 * @param sym The symbol with protected access
477 * @param c The class where the access takes place
478 * @param site The type of the qualifier
479 */
480 private
481 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
482 Type newSite = site.hasTag(TYPEVAR) ? site.getUpperBound() : site;
483 while (c != null &&
484 !(c.isSubClass(sym.owner, types) &&
485 (c.flags() & INTERFACE) == 0 &&
486 // In JLS 2e 6.6.2.1, the subclass restriction applies
487 // only to instance fields and methods -- types are excluded
488 // regardless of whether they are declared 'static' or not.
489 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || newSite.tsym.isSubClass(c, types))))
490 c = c.owner.enclClass();
491 return c != null;
492 }
493
494 /**
495 * Performs a recursive scan of a type looking for accessibility problems
496 * from current attribution environment
497 */
498 void checkAccessibleType(Env<AttrContext> env, Type t) {
499 accessibilityChecker.visit(t, env);
500 }
501
502 /**
503 * Accessibility type-visitor
504 */
505 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker =
506 new Types.SimpleVisitor<Void, Env<AttrContext>>() {
507
508 void visit(List<Type> ts, Env<AttrContext> env) {
509 for (Type t : ts) {
510 visit(t, env);
511 }
512 }
513
514 public Void visitType(Type t, Env<AttrContext> env) {
515 return null;
516 }
517
518 @Override
519 public Void visitArrayType(ArrayType t, Env<AttrContext> env) {
520 visit(t.elemtype, env);
521 return null;
522 }
523
524 @Override
525 public Void visitClassType(ClassType t, Env<AttrContext> env) {
526 visit(t.getTypeArguments(), env);
527 if (!isAccessible(env, t, true)) {
528 accessBase(new AccessError(env, null, t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true);
529 }
530 return null;
531 }
532
533 @Override
534 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) {
535 visit(t.type, env);
536 return null;
537 }
538
539 @Override
540 public Void visitMethodType(MethodType t, Env<AttrContext> env) {
541 visit(t.getParameterTypes(), env);
542 visit(t.getReturnType(), env);
543 visit(t.getThrownTypes(), env);
544 return null;
545 }
546 };
547
548 /** Try to instantiate the type of a method so that it fits
549 * given type arguments and argument types. If successful, return
550 * the method's instantiated type, else return null.
551 * The instantiation will take into account an additional leading
552 * formal parameter if the method is an instance method seen as a member
553 * of an under determined site. In this case, we treat site as an additional
554 * parameter and the parameters of the class containing the method as
555 * additional type variables that get instantiated.
556 *
557 * @param env The current environment
558 * @param site The type of which the method is a member.
559 * @param m The method symbol.
560 * @param argtypes The invocation's given value arguments.
561 * @param typeargtypes The invocation's given type arguments.
562 * @param allowBoxing Allow boxing conversions of arguments.
563 * @param useVarargs Box trailing arguments into an array for varargs.
564 */
565 Type rawInstantiate(Env<AttrContext> env,
566 Type site,
567 Symbol m,
568 ResultInfo resultInfo,
569 List<Type> argtypes,
570 List<Type> typeargtypes,
571 boolean allowBoxing,
572 boolean useVarargs,
573 Warner warn) throws Infer.InferenceException {
574 Type mt = types.memberType(site, m);
575 // tvars is the list of formal type variables for which type arguments
576 // need to inferred.
577 List<Type> tvars = List.nil();
578 if (typeargtypes == null) typeargtypes = List.nil();
579 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
580 // This is not a polymorphic method, but typeargs are supplied
581 // which is fine, see JLS 15.12.2.1
582 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
583 ForAll pmt = (ForAll) mt;
584 if (typeargtypes.length() != pmt.tvars.length())
585 // not enough args
586 throw new InapplicableMethodException(diags.fragment(Fragments.WrongNumberTypeArgs(Integer.toString(pmt.tvars.length()))));
587 // Check type arguments are within bounds
588 List<Type> formals = pmt.tvars;
589 List<Type> actuals = typeargtypes;
590 while (formals.nonEmpty() && actuals.nonEmpty()) {
591 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
592 pmt.tvars, typeargtypes);
593 for (; bounds.nonEmpty(); bounds = bounds.tail) {
594 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn)) {
595 throw new InapplicableMethodException(diags.fragment(Fragments.ExplicitParamDoNotConformToBounds(actuals.head, bounds)));
596 }
597 }
598 formals = formals.tail;
599 actuals = actuals.tail;
600 }
601 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
602 } else if (mt.hasTag(FORALL)) {
603 ForAll pmt = (ForAll) mt;
604 List<Type> tvars1 = types.newInstances(pmt.tvars);
605 tvars = tvars.appendList(tvars1);
606 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
607 }
608
609 // find out whether we need to go the slow route via infer
610 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/
611 for (List<Type> l = argtypes;
612 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
613 l = l.tail) {
614 if (l.head.hasTag(FORALL)) instNeeded = true;
615 }
616
617 if (instNeeded) {
618 return infer.instantiateMethod(env,
619 tvars,
620 (MethodType)mt,
621 resultInfo,
622 (MethodSymbol)m,
623 argtypes,
624 allowBoxing,
625 useVarargs,
626 currentResolutionContext,
627 warn);
628 }
629
630 DeferredAttr.DeferredAttrContext dc = currentResolutionContext.deferredAttrContext(m, infer.emptyContext, resultInfo, warn);
631 currentResolutionContext.methodCheck.argumentsAcceptable(env, dc,
632 argtypes, mt.getParameterTypes(), warn);
633 dc.complete();
634 return mt;
635 }
636
637 Type checkMethod(Env<AttrContext> env,
638 Type site,
639 Symbol m,
640 ResultInfo resultInfo,
641 List<Type> argtypes,
642 List<Type> typeargtypes,
643 Warner warn) {
644 MethodResolutionContext prevContext = currentResolutionContext;
645 try {
646 currentResolutionContext = new MethodResolutionContext();
647 currentResolutionContext.attrMode = (resultInfo.pt == Infer.anyPoly) ?
648 AttrMode.SPECULATIVE : DeferredAttr.AttrMode.CHECK;
649 if (env.tree.hasTag(JCTree.Tag.REFERENCE)) {
650 //method/constructor references need special check class
651 //to handle inference variables in 'argtypes' (might happen
652 //during an unsticking round)
653 currentResolutionContext.methodCheck =
654 new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
655 }
656 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase;
657 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
658 step.isBoxingRequired(), step.isVarargsRequired(), warn);
659 }
660 finally {
661 currentResolutionContext = prevContext;
662 }
663 }
664
665 /** Same but returns null instead throwing a NoInstanceException
666 */
667 Type instantiate(Env<AttrContext> env,
668 Type site,
669 Symbol m,
670 ResultInfo resultInfo,
671 List<Type> argtypes,
672 List<Type> typeargtypes,
673 boolean allowBoxing,
674 boolean useVarargs,
675 Warner warn) {
676 try {
677 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
678 allowBoxing, useVarargs, warn);
679 } catch (InapplicableMethodException ex) {
680 return null;
681 }
682 }
683
684 /**
685 * This interface defines an entry point that should be used to perform a
686 * method check. A method check usually consist in determining as to whether
687 * a set of types (actuals) is compatible with another set of types (formals).
688 * Since the notion of compatibility can vary depending on the circumstances,
689 * this interfaces allows to easily add new pluggable method check routines.
690 */
691 interface MethodCheck {
692 /**
693 * Main method check routine. A method check usually consist in determining
694 * as to whether a set of types (actuals) is compatible with another set of
695 * types (formals). If an incompatibility is found, an unchecked exception
696 * is assumed to be thrown.
697 */
698 void argumentsAcceptable(Env<AttrContext> env,
699 DeferredAttrContext deferredAttrContext,
700 List<Type> argtypes,
701 List<Type> formals,
702 Warner warn);
703
704 /**
705 * Retrieve the method check object that will be used during a
706 * most specific check.
707 */
708 MethodCheck mostSpecificCheck(List<Type> actuals);
709 }
710
711 /**
712 * Helper enum defining all method check diagnostics (used by resolveMethodCheck).
713 */
714 enum MethodCheckDiag {
715 /**
716 * Actuals and formals differs in length.
717 */
718 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"),
719 /**
720 * An actual is incompatible with a formal.
721 */
722 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"),
723 /**
724 * An actual is incompatible with the varargs element type.
725 */
726 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"),
727 /**
728 * The varargs element type is inaccessible.
729 */
730 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type");
731
732 final String basicKey;
733 final String inferKey;
734
735 MethodCheckDiag(String basicKey, String inferKey) {
736 this.basicKey = basicKey;
737 this.inferKey = inferKey;
738 }
739
740 String regex() {
741 return String.format("([a-z]*\\.)*(%s|%s)", basicKey, inferKey);
742 }
743 }
744
745 /**
746 * Dummy method check object. All methods are deemed applicable, regardless
747 * of their formal parameter types.
748 */
749 MethodCheck nilMethodCheck = new MethodCheck() {
750 public void argumentsAcceptable(Env<AttrContext> env, DeferredAttrContext deferredAttrContext, List<Type> argtypes, List<Type> formals, Warner warn) {
751 //do nothing - method always applicable regardless of actuals
752 }
753
754 public MethodCheck mostSpecificCheck(List<Type> actuals) {
755 return this;
756 }
757 };
758
759 /**
760 * Base class for 'real' method checks. The class defines the logic for
761 * iterating through formals and actuals and provides and entry point
762 * that can be used by subclasses in order to define the actual check logic.
763 */
764 abstract class AbstractMethodCheck implements MethodCheck {
765 @Override
766 public void argumentsAcceptable(final Env<AttrContext> env,
767 DeferredAttrContext deferredAttrContext,
768 List<Type> argtypes,
769 List<Type> formals,
770 Warner warn) {
771 //should we expand formals?
772 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired();
773 JCTree callTree = treeForDiagnostics(env);
774 List<JCExpression> trees = TreeInfo.args(callTree);
775
776 //inference context used during this method check
777 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
778
779 Type varargsFormal = useVarargs ? formals.last() : null;
780
781 if (varargsFormal == null &&
782 argtypes.size() != formals.size()) {
783 reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
784 }
785
786 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
787 DiagnosticPosition pos = trees != null ? trees.head : null;
788 checkArg(pos, false, argtypes.head, formals.head, deferredAttrContext, warn);
789 argtypes = argtypes.tail;
790 formals = formals.tail;
791 trees = trees != null ? trees.tail : trees;
792 }
793
794 if (formals.head != varargsFormal) {
795 reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
796 }
797
798 if (useVarargs) {
799 //note: if applicability check is triggered by most specific test,
800 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
801 final Type elt = types.elemtype(varargsFormal);
802 while (argtypes.nonEmpty()) {
803 DiagnosticPosition pos = trees != null ? trees.head : null;
804 checkArg(pos, true, argtypes.head, elt, deferredAttrContext, warn);
805 argtypes = argtypes.tail;
806 trees = trees != null ? trees.tail : trees;
807 }
808 }
809 }
810
811 // where
812 private JCTree treeForDiagnostics(Env<AttrContext> env) {
813 return env.info.preferredTreeForDiagnostics != null ? env.info.preferredTreeForDiagnostics : env.tree;
814 }
815
816 /**
817 * Does the actual argument conforms to the corresponding formal?
818 */
819 abstract void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn);
820
821 protected void reportMC(DiagnosticPosition pos, MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
822 boolean inferDiag = inferenceContext != infer.emptyContext;
823 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) {
824 Object[] args2 = new Object[args.length + 1];
825 System.arraycopy(args, 0, args2, 1, args.length);
826 args2[0] = inferenceContext.inferenceVars();
827 args = args2;
828 }
829 String key = inferDiag ? diag.inferKey : diag.basicKey;
830 throw inferDiag ?
831 infer.error(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args)) :
832 methodCheckFailure.setMessage(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args));
833 }
834
835 /**
836 * To eliminate the overhead associated with allocating an exception object in such an
837 * hot execution path, we use flyweight pattern - and share the same exception instance
838 * across multiple method check failures.
839 */
840 class SharedInapplicableMethodException extends InapplicableMethodException {
841 private static final long serialVersionUID = 0;
842
843 SharedInapplicableMethodException() {
844 super(null);
845 }
846
847 SharedInapplicableMethodException setMessage(JCDiagnostic details) {
848 this.diagnostic = details;
849 return this;
850 }
851 }
852
853 SharedInapplicableMethodException methodCheckFailure = new SharedInapplicableMethodException();
854
855 public MethodCheck mostSpecificCheck(List<Type> actuals) {
856 return nilMethodCheck;
857 }
858
859 }
860
861 /**
862 * Arity-based method check. A method is applicable if the number of actuals
863 * supplied conforms to the method signature.
864 */
865 MethodCheck arityMethodCheck = new AbstractMethodCheck() {
866 @Override
867 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
868 //do nothing - actual always compatible to formals
869 }
870
871 @Override
872 public String toString() {
873 return "arityMethodCheck";
874 }
875 };
876
877 /**
878 * Main method applicability routine. Given a list of actual types A,
879 * a list of formal types F, determines whether the types in A are
880 * compatible (by method invocation conversion) with the types in F.
881 *
882 * Since this routine is shared between overload resolution and method
883 * type-inference, a (possibly empty) inference context is used to convert
884 * formal types to the corresponding 'undet' form ahead of a compatibility
885 * check so that constraints can be propagated and collected.
886 *
887 * Moreover, if one or more types in A is a deferred type, this routine uses
888 * DeferredAttr in order to perform deferred attribution. If one or more actual
889 * deferred types are stuck, they are placed in a queue and revisited later
890 * after the remainder of the arguments have been seen. If this is not sufficient
891 * to 'unstuck' the argument, a cyclic inference error is called out.
892 *
893 * A method check handler (see above) is used in order to report errors.
894 */
895 MethodCheck resolveMethodCheck = new AbstractMethodCheck() {
896
897 @Override
898 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
899 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
900 mresult.check(pos, actual);
901 }
902
903 @Override
904 public void argumentsAcceptable(final Env<AttrContext> env,
905 DeferredAttrContext deferredAttrContext,
906 List<Type> argtypes,
907 List<Type> formals,
908 Warner warn) {
909 super.argumentsAcceptable(env, deferredAttrContext, argtypes, formals, warn);
910 // should we check varargs element type accessibility?
911 if (deferredAttrContext.phase.isVarargsRequired()) {
912 if (deferredAttrContext.mode == AttrMode.CHECK) {
913 varargsAccessible(env, types.elemtype(formals.last()), deferredAttrContext.inferenceContext);
914 }
915 }
916 }
917
918 /**
919 * Test that the runtime array element type corresponding to 't' is accessible. 't' should be the
920 * varargs element type of either the method invocation type signature (after inference completes)
921 * or the method declaration signature (before inference completes).
922 */
923 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) {
924 if (inferenceContext.free(t)) {
925 inferenceContext.addFreeTypeListener(List.of(t),
926 solvedContext -> varargsAccessible(env, solvedContext.asInstType(t), solvedContext));
927 } else {
928 if (!isAccessible(env, types.erasure(t))) {
929 Symbol location = env.enclClass.sym;
930 reportMC(env.tree, MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
931 }
932 }
933 }
934
935 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
936 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
937 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
938 MethodCheckDiag methodDiag = varargsCheck ?
939 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
940
941 @Override
942 public void report(DiagnosticPosition pos, JCDiagnostic details) {
943 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
944 }
945 };
946 return new MethodResultInfo(to, checkContext);
947 }
948
949 @Override
950 public MethodCheck mostSpecificCheck(List<Type> actuals) {
951 return new MostSpecificCheck(actuals);
952 }
953
954 @Override
955 public String toString() {
956 return "resolveMethodCheck";
957 }
958 };
959
960 /**
961 * This class handles method reference applicability checks; since during
962 * these checks it's sometime possible to have inference variables on
963 * the actual argument types list, the method applicability check must be
964 * extended so that inference variables are 'opened' as needed.
965 */
966 class MethodReferenceCheck extends AbstractMethodCheck {
967
968 InferenceContext pendingInferenceContext;
969
970 MethodReferenceCheck(InferenceContext pendingInferenceContext) {
971 this.pendingInferenceContext = pendingInferenceContext;
972 }
973
974 @Override
975 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
976 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
977 mresult.check(pos, actual);
978 }
979
980 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
981 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
982 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
983 MethodCheckDiag methodDiag = varargsCheck ?
984 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
985
986 @Override
987 public boolean compatible(Type found, Type req, Warner warn) {
988 found = pendingInferenceContext.asUndetVar(found);
989 if (found.hasTag(UNDETVAR) && req.isPrimitive()) {
990 req = types.boxedClass(req).type;
991 }
992 return super.compatible(found, req, warn);
993 }
994
995 @Override
996 public void report(DiagnosticPosition pos, JCDiagnostic details) {
997 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
998 }
999 };
1000 return new MethodResultInfo(to, checkContext);
1001 }
1002
1003 @Override
1004 public MethodCheck mostSpecificCheck(List<Type> actuals) {
1005 return new MostSpecificCheck(actuals);
1006 }
1007
1008 @Override
1009 public String toString() {
1010 return "MethodReferenceCheck";
1011 }
1012 }
1013
1014 /**
1015 * Check context to be used during method applicability checks. A method check
1016 * context might contain inference variables.
1017 */
1018 abstract class MethodCheckContext implements CheckContext {
1019
1020 boolean strict;
1021 DeferredAttrContext deferredAttrContext;
1022 Warner rsWarner;
1023
1024 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) {
1025 this.strict = strict;
1026 this.deferredAttrContext = deferredAttrContext;
1027 this.rsWarner = rsWarner;
1028 }
1029
1030 public boolean compatible(Type found, Type req, Warner warn) {
1031 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
1032 return strict ?
1033 types.isSubtypeUnchecked(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn) :
1034 types.isConvertible(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn);
1035 }
1036
1037 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1038 throw new InapplicableMethodException(details);
1039 }
1040
1041 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
1042 return rsWarner;
1043 }
1044
1045 public InferenceContext inferenceContext() {
1046 return deferredAttrContext.inferenceContext;
1047 }
1048
1049 public DeferredAttrContext deferredAttrContext() {
1050 return deferredAttrContext;
1051 }
1052
1053 @Override
1054 public String toString() {
1055 return "MethodCheckContext";
1056 }
1057 }
1058
1059 /**
1060 * ResultInfo class to be used during method applicability checks. Check
1061 * for deferred types goes through special path.
1062 */
1063 class MethodResultInfo extends ResultInfo {
1064
1065 public MethodResultInfo(Type pt, CheckContext checkContext) {
1066 attr.super(KindSelector.VAL, pt, checkContext);
1067 }
1068
1069 @Override
1070 protected Type check(DiagnosticPosition pos, Type found) {
1071 if (found.hasTag(DEFERRED)) {
1072 DeferredType dt = (DeferredType)found;
1073 return dt.check(this);
1074 } else {
1075 Type uResult = U(found);
1076 Type capturedType = pos == null || pos.getTree() == null ?
1077 types.capture(uResult) :
1078 checkContext.inferenceContext()
1079 .cachedCapture(pos.getTree(), uResult, true);
1080 return super.check(pos, chk.checkNonVoid(pos, capturedType));
1081 }
1082 }
1083
1084 /**
1085 * javac has a long-standing 'simplification' (see 6391995):
1086 * given an actual argument type, the method check is performed
1087 * on its upper bound. This leads to inconsistencies when an
1088 * argument type is checked against itself. For example, given
1089 * a type-variable T, it is not true that {@code U(T) <: T},
1090 * so we need to guard against that.
1091 */
1092 private Type U(Type found) {
1093 return found == pt ?
1094 found : types.cvarUpperBound(found);
1095 }
1096
1097 @Override
1098 protected MethodResultInfo dup(Type newPt) {
1099 return new MethodResultInfo(newPt, checkContext);
1100 }
1101
1102 @Override
1103 protected ResultInfo dup(CheckContext newContext) {
1104 return new MethodResultInfo(pt, newContext);
1105 }
1106
1107 @Override
1108 protected ResultInfo dup(Type newPt, CheckContext newContext) {
1109 return new MethodResultInfo(newPt, newContext);
1110 }
1111 }
1112
1113 /**
1114 * Most specific method applicability routine. Given a list of actual types A,
1115 * a list of formal types F1, and a list of formal types F2, the routine determines
1116 * as to whether the types in F1 can be considered more specific than those in F2 w.r.t.
1117 * argument types A.
1118 */
1119 class MostSpecificCheck implements MethodCheck {
1120
1121 List<Type> actuals;
1122
1123 MostSpecificCheck(List<Type> actuals) {
1124 this.actuals = actuals;
1125 }
1126
1127 @Override
1128 public void argumentsAcceptable(final Env<AttrContext> env,
1129 DeferredAttrContext deferredAttrContext,
1130 List<Type> formals1,
1131 List<Type> formals2,
1132 Warner warn) {
1133 formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired());
1134 while (formals2.nonEmpty()) {
1135 ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head);
1136 mresult.check(null, formals1.head);
1137 formals1 = formals1.tail;
1138 formals2 = formals2.tail;
1139 actuals = actuals.isEmpty() ? actuals : actuals.tail;
1140 }
1141 }
1142
1143 /**
1144 * Create a method check context to be used during the most specific applicability check
1145 */
1146 ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext,
1147 Warner rsWarner, Type actual) {
1148 return attr.new ResultInfo(KindSelector.VAL, to,
1149 new MostSpecificCheckContext(deferredAttrContext, rsWarner, actual));
1150 }
1151
1152 /**
1153 * Subclass of method check context class that implements most specific
1154 * method conversion. If the actual type under analysis is a deferred type
1155 * a full blown structural analysis is carried out.
1156 */
1157 class MostSpecificCheckContext extends MethodCheckContext {
1158
1159 Type actual;
1160
1161 public MostSpecificCheckContext(DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) {
1162 super(true, deferredAttrContext, rsWarner);
1163 this.actual = actual;
1164 }
1165
1166 public boolean compatible(Type found, Type req, Warner warn) {
1167 if (unrelatedFunctionalInterfaces(found, req) &&
1168 (actual != null && actual.getTag() == DEFERRED)) {
1169 DeferredType dt = (DeferredType) actual;
1170 JCTree speculativeTree = dt.speculativeTree(deferredAttrContext);
1171 if (speculativeTree != deferredAttr.stuckTree) {
1172 return functionalInterfaceMostSpecific(found, req, speculativeTree);
1173 }
1174 }
1175 return compatibleBySubtyping(found, req);
1176 }
1177
1178 private boolean compatibleBySubtyping(Type found, Type req) {
1179 if (!strict && found.isPrimitive() != req.isPrimitive()) {
1180 found = found.isPrimitive() ? types.boxedClass(found).type : types.unboxedType(found);
1181 }
1182 return types.isSubtypeNoCapture(found, deferredAttrContext.inferenceContext.asUndetVar(req));
1183 }
1184
1185 /** Whether {@code t} and {@code s} are unrelated functional interface types. */
1186 private boolean unrelatedFunctionalInterfaces(Type t, Type s) {
1187 return types.isFunctionalInterface(t.tsym) &&
1188 types.isFunctionalInterface(s.tsym) &&
1189 unrelatedInterfaces(t, s);
1190 }
1191
1192 /** Whether {@code t} and {@code s} are unrelated interface types; recurs on intersections. **/
1193 private boolean unrelatedInterfaces(Type t, Type s) {
1194 if (t.isCompound()) {
1195 for (Type ti : types.interfaces(t)) {
1196 if (!unrelatedInterfaces(ti, s)) {
1197 return false;
1198 }
1199 }
1200 return true;
1201 } else if (s.isCompound()) {
1202 for (Type si : types.interfaces(s)) {
1203 if (!unrelatedInterfaces(t, si)) {
1204 return false;
1205 }
1206 }
1207 return true;
1208 } else {
1209 return types.asSuper(t, s.tsym) == null && types.asSuper(s, t.tsym) == null;
1210 }
1211 }
1212
1213 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */
1214 private boolean functionalInterfaceMostSpecific(Type t, Type s, JCTree tree) {
1215 Type tDesc = types.findDescriptorType(types.capture(t));
1216 Type tDescNoCapture = types.findDescriptorType(t);
1217 Type sDesc = types.findDescriptorType(s);
1218 final List<Type> tTypeParams = tDesc.getTypeArguments();
1219 final List<Type> tTypeParamsNoCapture = tDescNoCapture.getTypeArguments();
1220 final List<Type> sTypeParams = sDesc.getTypeArguments();
1221
1222 // compare type parameters
1223 if (tDesc.hasTag(FORALL) && !types.hasSameBounds((ForAll) tDesc, (ForAll) tDescNoCapture)) {
1224 return false;
1225 }
1226 // can't use Types.hasSameBounds on sDesc because bounds may have ivars
1227 List<Type> tIter = tTypeParams;
1228 List<Type> sIter = sTypeParams;
1229 while (tIter.nonEmpty() && sIter.nonEmpty()) {
1230 Type tBound = tIter.head.getUpperBound();
1231 Type sBound = types.subst(sIter.head.getUpperBound(), sTypeParams, tTypeParams);
1232 if (tBound.containsAny(tTypeParams) && inferenceContext().free(sBound)) {
1233 return false;
1234 }
1235 if (!types.isSameType(tBound, inferenceContext().asUndetVar(sBound))) {
1236 return false;
1237 }
1238 tIter = tIter.tail;
1239 sIter = sIter.tail;
1240 }
1241 if (!tIter.isEmpty() || !sIter.isEmpty()) {
1242 return false;
1243 }
1244
1245 // compare parameters
1246 List<Type> tParams = tDesc.getParameterTypes();
1247 List<Type> tParamsNoCapture = tDescNoCapture.getParameterTypes();
1248 List<Type> sParams = sDesc.getParameterTypes();
1249 while (tParams.nonEmpty() && tParamsNoCapture.nonEmpty() && sParams.nonEmpty()) {
1250 Type tParam = tParams.head;
1251 Type tParamNoCapture = types.subst(tParamsNoCapture.head, tTypeParamsNoCapture, tTypeParams);
1252 Type sParam = types.subst(sParams.head, sTypeParams, tTypeParams);
1253 if (tParam.containsAny(tTypeParams) && inferenceContext().free(sParam)) {
1254 return false;
1255 }
1256 if (!types.isSubtype(inferenceContext().asUndetVar(sParam), tParam)) {
1257 return false;
1258 }
1259 if (!types.isSameType(tParamNoCapture, inferenceContext().asUndetVar(sParam))) {
1260 return false;
1261 }
1262 tParams = tParams.tail;
1263 tParamsNoCapture = tParamsNoCapture.tail;
1264 sParams = sParams.tail;
1265 }
1266 if (!tParams.isEmpty() || !tParamsNoCapture.isEmpty() || !sParams.isEmpty()) {
1267 return false;
1268 }
1269
1270 // compare returns
1271 Type tRet = tDesc.getReturnType();
1272 Type sRet = types.subst(sDesc.getReturnType(), sTypeParams, tTypeParams);
1273 if (tRet.containsAny(tTypeParams) && inferenceContext().free(sRet)) {
1274 return false;
1275 }
1276 MostSpecificFunctionReturnChecker msc = new MostSpecificFunctionReturnChecker(tRet, sRet);
1277 msc.scan(tree);
1278 return msc.result;
1279 }
1280
1281 /**
1282 * Tests whether one functional interface type can be considered more specific
1283 * than another unrelated functional interface type for the scanned expression.
1284 */
1285 class MostSpecificFunctionReturnChecker extends DeferredAttr.PolyScanner {
1286
1287 final Type tRet;
1288 final Type sRet;
1289 boolean result;
1290
1291 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */
1292 MostSpecificFunctionReturnChecker(Type tRet, Type sRet) {
1293 this.tRet = tRet;
1294 this.sRet = sRet;
1295 result = true;
1296 }
1297
1298 @Override
1299 void skip(JCTree tree) {
1300 result = false;
1301 }
1302
1303 @Override
1304 public void visitConditional(JCConditional tree) {
1305 scan(asExpr(tree.truepart));
1306 scan(asExpr(tree.falsepart));
1307 }
1308
1309 @Override
1310 public void visitReference(JCMemberReference tree) {
1311 if (sRet.hasTag(VOID)) {
1312 // do nothing
1313 } else if (tRet.hasTag(VOID)) {
1314 result = false;
1315 } else if (tRet.isPrimitive() != sRet.isPrimitive()) {
1316 boolean retValIsPrimitive =
1317 tree.refPolyKind == PolyKind.STANDALONE &&
1318 tree.sym.type.getReturnType().isPrimitive();
1319 result &= (retValIsPrimitive == tRet.isPrimitive()) &&
1320 (retValIsPrimitive != sRet.isPrimitive());
1321 } else {
1322 result &= compatibleBySubtyping(tRet, sRet);
1323 }
1324 }
1325
1326 @Override
1327 public void visitParens(JCParens tree) {
1328 scan(asExpr(tree.expr));
1329 }
1330
1331 @Override
1332 public void visitLambda(JCLambda tree) {
1333 if (sRet.hasTag(VOID)) {
1334 // do nothing
1335 } else if (tRet.hasTag(VOID)) {
1336 result = false;
1337 } else {
1338 List<JCExpression> lambdaResults = lambdaResults(tree);
1339 if (!lambdaResults.isEmpty() && unrelatedFunctionalInterfaces(tRet, sRet)) {
1340 for (JCExpression expr : lambdaResults) {
1341 result &= functionalInterfaceMostSpecific(tRet, sRet, expr);
1342 }
1343 } else if (!lambdaResults.isEmpty() && tRet.isPrimitive() != sRet.isPrimitive()) {
1344 for (JCExpression expr : lambdaResults) {
1345 boolean retValIsPrimitive = expr.isStandalone() && expr.type.isPrimitive();
1346 result &= (retValIsPrimitive == tRet.isPrimitive()) &&
1347 (retValIsPrimitive != sRet.isPrimitive());
1348 }
1349 } else {
1350 result &= compatibleBySubtyping(tRet, sRet);
1351 }
1352 }
1353 }
1354 //where
1355
1356 private List<JCExpression> lambdaResults(JCLambda lambda) {
1357 if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) {
1358 return List.of(asExpr((JCExpression) lambda.body));
1359 } else {
1360 final ListBuffer<JCExpression> buffer = new ListBuffer<>();
1361 DeferredAttr.LambdaReturnScanner lambdaScanner =
1362 new DeferredAttr.LambdaReturnScanner() {
1363 @Override
1364 public void visitReturn(JCReturn tree) {
1365 if (tree.expr != null) {
1366 buffer.append(asExpr(tree.expr));
1367 }
1368 }
1369 };
1370 lambdaScanner.scan(lambda.body);
1371 return buffer.toList();
1372 }
1373 }
1374
1375 private JCExpression asExpr(JCExpression expr) {
1376 if (expr.type.hasTag(DEFERRED)) {
1377 JCTree speculativeTree = ((DeferredType)expr.type).speculativeTree(deferredAttrContext);
1378 if (speculativeTree != deferredAttr.stuckTree) {
1379 expr = (JCExpression)speculativeTree;
1380 }
1381 }
1382 return expr;
1383 }
1384 }
1385
1386 }
1387
1388 public MethodCheck mostSpecificCheck(List<Type> actuals) {
1389 Assert.error("Cannot get here!");
1390 return null;
1391 }
1392 }
1393
1394 public static class InapplicableMethodException extends RuntimeException {
1395 private static final long serialVersionUID = 0;
1396
1397 transient JCDiagnostic diagnostic;
1398
1399 InapplicableMethodException(JCDiagnostic diag) {
1400 this.diagnostic = diag;
1401 }
1402
1403 public JCDiagnostic getDiagnostic() {
1404 return diagnostic;
1405 }
1406
1407 @Override
1408 public Throwable fillInStackTrace() {
1409 // This is an internal exception; the stack trace is irrelevant.
1410 return this;
1411 }
1412 }
1413
1414 /* ***************************************************************************
1415 * Symbol lookup
1416 * the following naming conventions for arguments are used
1417 *
1418 * env is the environment where the symbol was mentioned
1419 * site is the type of which the symbol is a member
1420 * name is the symbol's name
1421 * if no arguments are given
1422 * argtypes are the value arguments, if we search for a method
1423 *
1424 * If no symbol was found, a ResolveError detailing the problem is returned.
1425 ****************************************************************************/
1426
1427 /** Find field. Synthetic fields are always skipped.
1428 * @param env The current environment.
1429 * @param site The original type from where the selection takes place.
1430 * @param name The name of the field.
1431 * @param c The class to search for the field. This is always
1432 * a superclass or implemented interface of site's class.
1433 */
1434 Symbol findField(Env<AttrContext> env,
1435 Type site,
1436 Name name,
1437 TypeSymbol c) {
1438 while (c.type.hasTag(TYPEVAR))
1439 c = c.type.getUpperBound().tsym;
1440 Symbol bestSoFar = varNotFound;
1441 Symbol sym;
1442 for (Symbol s : c.members().getSymbolsByName(name)) {
1443 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) {
1444 return isAccessible(env, site, s)
1445 ? s : new AccessError(env, site, s);
1446 }
1447 }
1448 Type st = types.supertype(c.type);
1449 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) {
1450 sym = findField(env, site, name, st.tsym);
1451 bestSoFar = bestOf(bestSoFar, sym);
1452 }
1453 for (List<Type> l = types.interfaces(c.type);
1454 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1455 l = l.tail) {
1456 sym = findField(env, site, name, l.head.tsym);
1457 if (bestSoFar.exists() && sym.exists() &&
1458 sym.owner != bestSoFar.owner)
1459 bestSoFar = new AmbiguityError(bestSoFar, sym);
1460 else
1461 bestSoFar = bestOf(bestSoFar, sym);
1462 }
1463 return bestSoFar;
1464 }
1465
1466 /** Resolve a field identifier, throw a fatal error if not found.
1467 * @param pos The position to use for error reporting.
1468 * @param env The environment current at the method invocation.
1469 * @param site The type of the qualifying expression, in which
1470 * identifier is searched.
1471 * @param name The identifier's name.
1472 */
1473 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
1474 Type site, Name name) {
1475 Symbol sym = findField(env, site, name, site.tsym);
1476 if (sym.kind == VAR) return (VarSymbol)sym;
1477 else throw new FatalError(
1478 diags.fragment(Fragments.FatalErrCantLocateField(name)));
1479 }
1480
1481 /** Find unqualified variable or field with given name.
1482 * Synthetic fields always skipped.
1483 * @param env The current environment.
1484 * @param name The name of the variable or field.
1485 */
1486 Symbol findVar(Env<AttrContext> env, Name name) {
1487 Symbol bestSoFar = varNotFound;
1488 Env<AttrContext> env1 = env;
1489 boolean staticOnly = false;
1490 while (env1.outer != null) {
1491 Symbol sym = null;
1492 for (Symbol s : env1.info.scope.getSymbolsByName(name)) {
1493 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) {
1494 sym = s;
1495 if (staticOnly) {
1496 return new StaticError(sym);
1497 }
1498 break;
1499 }
1500 }
1501 if (isStatic(env1)) staticOnly = true;
1502 if (sym == null) {
1503 sym = findField(env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
1504 }
1505 if (sym.exists()) {
1506 if (staticOnly &&
1507 sym.kind == VAR &&
1508 sym.owner.kind == TYP &&
1509 (sym.flags() & STATIC) == 0)
1510 return new StaticError(sym);
1511 else
1512 return sym;
1513 } else {
1514 bestSoFar = bestOf(bestSoFar, sym);
1515 }
1516
1517 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1518 env1 = env1.outer;
1519 }
1520
1521 Symbol sym = findField(env, syms.predefClass.type, name, syms.predefClass);
1522 if (sym.exists())
1523 return sym;
1524 if (bestSoFar.exists())
1525 return bestSoFar;
1526
1527 Symbol origin = null;
1528 for (Scope sc : new Scope[] { env.toplevel.namedImportScope, env.toplevel.starImportScope }) {
1529 for (Symbol currentSymbol : sc.getSymbolsByName(name)) {
1530 if (currentSymbol.kind != VAR)
1531 continue;
1532 // invariant: sym.kind == Symbol.Kind.VAR
1533 if (!bestSoFar.kind.isResolutionError() &&
1534 currentSymbol.owner != bestSoFar.owner)
1535 return new AmbiguityError(bestSoFar, currentSymbol);
1536 else if (!bestSoFar.kind.betterThan(VAR)) {
1537 origin = sc.getOrigin(currentSymbol).owner;
1538 bestSoFar = isAccessible(env, origin.type, currentSymbol)
1539 ? currentSymbol : new AccessError(env, origin.type, currentSymbol);
1540 }
1541 }
1542 if (bestSoFar.exists()) break;
1543 }
1544 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
1545 return bestSoFar.clone(origin);
1546 else
1547 return bestSoFar;
1548 }
1549
1550 Warner noteWarner = new Warner();
1551
1552 /** Select the best method for a call site among two choices.
1553 * @param env The current environment.
1554 * @param site The original type from where the
1555 * selection takes place.
1556 * @param argtypes The invocation's value arguments,
1557 * @param typeargtypes The invocation's type arguments,
1558 * @param sym Proposed new best match.
1559 * @param bestSoFar Previously found best match.
1560 * @param allowBoxing Allow boxing conversions of arguments.
1561 * @param useVarargs Box trailing arguments into an array for varargs.
1562 */
1563 @SuppressWarnings("fallthrough")
1564 Symbol selectBest(Env<AttrContext> env,
1565 Type site,
1566 List<Type> argtypes,
1567 List<Type> typeargtypes,
1568 Symbol sym,
1569 Symbol bestSoFar,
1570 boolean allowBoxing,
1571 boolean useVarargs) {
1572 if (sym.kind == ERR ||
1573 (site.tsym != sym.owner && !sym.isInheritedIn(site.tsym, types)) ||
1574 !notOverriddenIn(site, sym)) {
1575 return bestSoFar;
1576 } else if (useVarargs && (sym.flags() & VARARGS) == 0) {
1577 return bestSoFar.kind.isResolutionError() ?
1578 new BadVarargsMethod((ResolveError)bestSoFar.baseSymbol()) :
1579 bestSoFar;
1580 }
1581 Assert.check(!sym.kind.isResolutionError());
1582 try {
1583 types.noWarnings.clear();
1584 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes,
1585 allowBoxing, useVarargs, types.noWarnings);
1586 currentResolutionContext.addApplicableCandidate(sym, mt);
1587 } catch (InapplicableMethodException ex) {
1588 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic());
1589 // Currently, an InapplicableMethodException occurs.
1590 // If bestSoFar.kind was ABSENT_MTH, return an InapplicableSymbolError(kind is WRONG_MTH).
1591 // If bestSoFar.kind was HIDDEN(AccessError)/WRONG_MTH/WRONG_MTHS, return an InapplicableSymbolsError(kind is WRONG_MTHS).
1592 // See JDK-8255968 for more information.
1593 switch (bestSoFar.kind) {
1594 case ABSENT_MTH:
1595 return new InapplicableSymbolError(currentResolutionContext);
1596 case HIDDEN:
1597 if (bestSoFar instanceof AccessError accessError) {
1598 // Add the JCDiagnostic of previous AccessError to the currentResolutionContext
1599 // and construct InapplicableSymbolsError.
1600 // Intentionally fallthrough.
1601 currentResolutionContext.addInapplicableCandidate(accessError.sym,
1602 accessError.getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT, null, null, site, null, argtypes, typeargtypes));
1603 } else {
1604 return bestSoFar;
1605 }
1606 case WRONG_MTH:
1607 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1608 default:
1609 return bestSoFar;
1610 }
1611 }
1612 if (!isAccessible(env, site, sym)) {
1613 AccessError curAccessError = new AccessError(env, site, sym);
1614 JCDiagnostic curDiagnostic = curAccessError.getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT, null, null, site, null, argtypes, typeargtypes);
1615 // Currently, an AccessError occurs.
1616 // If bestSoFar.kind was ABSENT_MTH, return an AccessError(kind is HIDDEN).
1617 // If bestSoFar.kind was HIDDEN(AccessError), WRONG_MTH, WRONG_MTHS, return an InapplicableSymbolsError(kind is WRONG_MTHS).
1618 // See JDK-8255968 for more information.
1619 if (bestSoFar.kind == ABSENT_MTH) {
1620 bestSoFar = curAccessError;
1621 } else if (bestSoFar.kind == WRONG_MTH) {
1622 // Add the JCDiagnostic of current AccessError to the currentResolutionContext
1623 // and construct InapplicableSymbolsError.
1624 currentResolutionContext.addInapplicableCandidate(sym, curDiagnostic);
1625 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1626 } else if (bestSoFar.kind == WRONG_MTHS) {
1627 // Add the JCDiagnostic of current AccessError to the currentResolutionContext
1628 currentResolutionContext.addInapplicableCandidate(sym, curDiagnostic);
1629 } else if (bestSoFar.kind == HIDDEN && bestSoFar instanceof AccessError accessError) {
1630 // Add the JCDiagnostics of previous and current AccessError to the currentResolutionContext
1631 // and construct InapplicableSymbolsError.
1632 currentResolutionContext.addInapplicableCandidate(accessError.sym,
1633 accessError.getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT, null, null, site, null, argtypes, typeargtypes));
1634 currentResolutionContext.addInapplicableCandidate(sym, curDiagnostic);
1635 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1636 }
1637 return bestSoFar;
1638 }
1639 return (bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS)
1640 ? sym
1641 : mostSpecific(argtypes, sym, bestSoFar, env, site, useVarargs);
1642 }
1643
1644 /* Return the most specific of the two methods for a call,
1645 * given that both are accessible and applicable.
1646 * @param m1 A new candidate for most specific.
1647 * @param m2 The previous most specific candidate.
1648 * @param env The current environment.
1649 * @param site The original type from where the selection
1650 * takes place.
1651 * @param allowBoxing Allow boxing conversions of arguments.
1652 * @param useVarargs Box trailing arguments into an array for varargs.
1653 */
1654 Symbol mostSpecific(List<Type> argtypes, Symbol m1,
1655 Symbol m2,
1656 Env<AttrContext> env,
1657 final Type site,
1658 boolean useVarargs) {
1659 switch (m2.kind) {
1660 case MTH:
1661 if (m1 == m2) return m1;
1662 boolean m1SignatureMoreSpecific =
1663 signatureMoreSpecific(argtypes, env, site, m1, m2, useVarargs);
1664 boolean m2SignatureMoreSpecific =
1665 signatureMoreSpecific(argtypes, env, site, m2, m1, useVarargs);
1666 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
1667 Type mt1 = types.memberType(site, m1);
1668 Type mt2 = types.memberType(site, m2);
1669 if (!types.overrideEquivalent(mt1, mt2))
1670 return ambiguityError(m1, m2);
1671
1672 // same signature; select (a) the non-bridge method, or
1673 // (b) the one that overrides the other, or (c) the concrete
1674 // one, or (d) merge both abstract signatures
1675 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
1676 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
1677
1678 if (m1.baseSymbol() == m2.baseSymbol()) {
1679 // this is the same imported symbol which has been cloned twice.
1680 // Return the first one (either will do).
1681 return m1;
1682 }
1683
1684 // if one overrides or hides the other, use it
1685 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
1686 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
1687 // the two owners can never be the same if the target methods are compiled from source,
1688 // but we need to protect against cases where the methods are defined in some classfile
1689 // and make sure we issue an ambiguity error accordingly (by skipping the logic below).
1690 if (m1Owner != m2Owner) {
1691 if (types.asSuper(m1Owner.type, m2Owner) != null &&
1692 ((m1.owner.flags_field & INTERFACE) == 0 ||
1693 (m2.owner.flags_field & INTERFACE) != 0) &&
1694 m1.overrides(m2, m1Owner, types, false))
1695 return m1;
1696 if (types.asSuper(m2Owner.type, m1Owner) != null &&
1697 ((m2.owner.flags_field & INTERFACE) == 0 ||
1698 (m1.owner.flags_field & INTERFACE) != 0) &&
1699 m2.overrides(m1, m2Owner, types, false))
1700 return m2;
1701 }
1702 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
1703 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
1704 if (m1Abstract && !m2Abstract) return m2;
1705 if (m2Abstract && !m1Abstract) return m1;
1706 // both abstract or both concrete
1707 return ambiguityError(m1, m2);
1708 }
1709 if (m1SignatureMoreSpecific) return m1;
1710 if (m2SignatureMoreSpecific) return m2;
1711 return ambiguityError(m1, m2);
1712 case AMBIGUOUS:
1713 //compare m1 to ambiguous methods in m2
1714 AmbiguityError e = (AmbiguityError)m2.baseSymbol();
1715 boolean m1MoreSpecificThanAnyAmbiguous = true;
1716 boolean allAmbiguousMoreSpecificThanM1 = true;
1717 for (Symbol s : e.ambiguousSyms) {
1718 Symbol moreSpecific = mostSpecific(argtypes, m1, s, env, site, useVarargs);
1719 m1MoreSpecificThanAnyAmbiguous &= moreSpecific == m1;
1720 allAmbiguousMoreSpecificThanM1 &= moreSpecific == s;
1721 }
1722 if (m1MoreSpecificThanAnyAmbiguous)
1723 return m1;
1724 //if m1 is more specific than some ambiguous methods, but other ambiguous methods are
1725 //more specific than m1, add it as a new ambiguous method:
1726 if (!allAmbiguousMoreSpecificThanM1)
1727 e.addAmbiguousSymbol(m1);
1728 return e;
1729 default:
1730 throw new AssertionError();
1731 }
1732 }
1733 //where
1734 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean useVarargs) {
1735 noteWarner.clear();
1736 int maxLength = Math.max(
1737 Math.max(m1.type.getParameterTypes().length(), actuals.length()),
1738 m2.type.getParameterTypes().length());
1739 MethodResolutionContext prevResolutionContext = currentResolutionContext;
1740 try {
1741 currentResolutionContext = new MethodResolutionContext();
1742 currentResolutionContext.step = prevResolutionContext.step;
1743 currentResolutionContext.methodCheck =
1744 prevResolutionContext.methodCheck.mostSpecificCheck(actuals);
1745 Type mst = instantiate(env, site, m2, null,
1746 adjustArgs(types.cvarLowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null,
1747 false, useVarargs, noteWarner);
1748 return mst != null &&
1749 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
1750 } finally {
1751 currentResolutionContext = prevResolutionContext;
1752 }
1753 }
1754
1755 List<Type> adjustArgs(List<Type> args, Symbol msym, int length, boolean allowVarargs) {
1756 if ((msym.flags() & VARARGS) != 0 && allowVarargs) {
1757 Type varargsElem = types.elemtype(args.last());
1758 if (varargsElem == null) {
1759 Assert.error("Bad varargs = " + args.last() + " " + msym);
1760 }
1761 List<Type> newArgs = args.reverse().tail.prepend(varargsElem).reverse();
1762 while (newArgs.length() < length) {
1763 newArgs = newArgs.append(newArgs.last());
1764 }
1765 return newArgs;
1766 } else {
1767 return args;
1768 }
1769 }
1770 //where
1771 Symbol ambiguityError(Symbol m1, Symbol m2) {
1772 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
1773 return (m1.flags() & CLASH) == 0 ? m1 : m2;
1774 } else {
1775 return new AmbiguityError(m1, m2);
1776 }
1777 }
1778
1779 Symbol findMethodInScope(Env<AttrContext> env,
1780 Type site,
1781 Name name,
1782 List<Type> argtypes,
1783 List<Type> typeargtypes,
1784 Scope sc,
1785 Symbol bestSoFar,
1786 boolean allowBoxing,
1787 boolean useVarargs,
1788 boolean abstractok) {
1789 for (Symbol s : sc.getSymbolsByName(name, new LookupFilter(abstractok))) {
1790 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s,
1791 bestSoFar, allowBoxing, useVarargs);
1792 }
1793 return bestSoFar;
1794 }
1795 //where
1796 class LookupFilter implements Predicate<Symbol> {
1797
1798 boolean abstractOk;
1799
1800 LookupFilter(boolean abstractOk) {
1801 this.abstractOk = abstractOk;
1802 }
1803
1804 @Override
1805 public boolean test(Symbol s) {
1806 long flags = s.flags();
1807 return s.kind == MTH &&
1808 (flags & SYNTHETIC) == 0 &&
1809 (abstractOk ||
1810 (flags & DEFAULT) != 0 ||
1811 (flags & ABSTRACT) == 0);
1812 }
1813 }
1814
1815 /** Find best qualified method matching given name, type and value
1816 * arguments.
1817 * @param env The current environment.
1818 * @param site The original type from where the selection
1819 * takes place.
1820 * @param name The method's name.
1821 * @param argtypes The method's value arguments.
1822 * @param typeargtypes The method's type arguments
1823 * @param allowBoxing Allow boxing conversions of arguments.
1824 * @param useVarargs Box trailing arguments into an array for varargs.
1825 */
1826 Symbol findMethod(Env<AttrContext> env,
1827 Type site,
1828 Name name,
1829 List<Type> argtypes,
1830 List<Type> typeargtypes,
1831 boolean allowBoxing,
1832 boolean useVarargs) {
1833 Symbol bestSoFar = methodNotFound;
1834 bestSoFar = findMethod(env,
1835 site,
1836 name,
1837 argtypes,
1838 typeargtypes,
1839 site.tsym.type,
1840 bestSoFar,
1841 allowBoxing,
1842 useVarargs);
1843 return bestSoFar;
1844 }
1845 // where
1846 private Symbol findMethod(Env<AttrContext> env,
1847 Type site,
1848 Name name,
1849 List<Type> argtypes,
1850 List<Type> typeargtypes,
1851 Type intype,
1852 Symbol bestSoFar,
1853 boolean allowBoxing,
1854 boolean useVarargs) {
1855 @SuppressWarnings({"unchecked","rawtypes"})
1856 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() };
1857
1858 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK;
1859 boolean isInterface = site.tsym.isInterface();
1860 for (TypeSymbol s : isInterface ? List.of(intype.tsym) : superclasses(intype)) {
1861 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1862 s.members(), bestSoFar, allowBoxing, useVarargs, true);
1863 if (name == names.init) return bestSoFar;
1864 iphase = (iphase == null) ? null : iphase.update(s, this);
1865 if (iphase != null) {
1866 for (Type itype : types.interfaces(s.type)) {
1867 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]);
1868 }
1869 }
1870 }
1871
1872 Symbol concrete = bestSoFar.kind.isValid() &&
1873 (bestSoFar.flags() & ABSTRACT) == 0 ?
1874 bestSoFar : methodNotFound;
1875
1876 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) {
1877 //keep searching for abstract methods
1878 for (Type itype : itypes[iphase2.ordinal()]) {
1879 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure())
1880 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK &&
1881 (itype.tsym.flags() & DEFAULT) == 0) continue;
1882 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1883 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, true);
1884 if (concrete != bestSoFar &&
1885 concrete.kind.isValid() &&
1886 bestSoFar.kind.isValid() &&
1887 types.isSubSignature(concrete.type, bestSoFar.type)) {
1888 //this is an hack - as javac does not do full membership checks
1889 //most specific ends up comparing abstract methods that might have
1890 //been implemented by some concrete method in a subclass and,
1891 //because of raw override, it is possible for an abstract method
1892 //to be more specific than the concrete method - so we need
1893 //to explicitly call that out (see CR 6178365)
1894 bestSoFar = concrete;
1895 }
1896 }
1897 }
1898 if (isInterface && bestSoFar.kind.isResolutionError()) {
1899 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1900 syms.objectType.tsym.members(), bestSoFar, allowBoxing, useVarargs, true);
1901 if (bestSoFar.kind.isValid()) {
1902 Symbol baseSymbol = bestSoFar;
1903 bestSoFar = new MethodSymbol(bestSoFar.flags_field, bestSoFar.name, bestSoFar.type, intype.tsym) {
1904 @Override
1905 public Symbol baseSymbol() {
1906 return baseSymbol;
1907 }
1908 };
1909 }
1910 }
1911 return bestSoFar;
1912 }
1913
1914 enum InterfaceLookupPhase {
1915 ABSTRACT_OK() {
1916 @Override
1917 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1918 //We should not look for abstract methods if receiver is a concrete class
1919 //(as concrete classes are expected to implement all abstracts coming
1920 //from superinterfaces)
1921 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) {
1922 return this;
1923 } else {
1924 return DEFAULT_OK;
1925 }
1926 }
1927 },
1928 DEFAULT_OK() {
1929 @Override
1930 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1931 return this;
1932 }
1933 };
1934
1935 abstract InterfaceLookupPhase update(Symbol s, Resolve rs);
1936 }
1937
1938 /**
1939 * Return an Iterable object to scan the superclasses of a given type.
1940 * It's crucial that the scan is done lazily, as we don't want to accidentally
1941 * access more supertypes than strictly needed (as this could trigger completion
1942 * errors if some of the not-needed supertypes are missing/ill-formed).
1943 */
1944 Iterable<TypeSymbol> superclasses(final Type intype) {
1945 return () -> new Iterator<TypeSymbol>() {
1946
1947 List<TypeSymbol> seen = List.nil();
1948 TypeSymbol currentSym = symbolFor(intype);
1949 TypeSymbol prevSym = null;
1950
1951 public boolean hasNext() {
1952 if (currentSym == syms.noSymbol) {
1953 currentSym = symbolFor(types.supertype(prevSym.type));
1954 }
1955 return currentSym != null;
1956 }
1957
1958 public TypeSymbol next() {
1959 prevSym = currentSym;
1960 currentSym = syms.noSymbol;
1961 Assert.check(prevSym != null || prevSym != syms.noSymbol);
1962 return prevSym;
1963 }
1964
1965 public void remove() {
1966 throw new UnsupportedOperationException();
1967 }
1968
1969 TypeSymbol symbolFor(Type t) {
1970 if (!t.hasTag(CLASS) &&
1971 !t.hasTag(TYPEVAR)) {
1972 return null;
1973 }
1974 t = types.skipTypeVars(t, false);
1975 if (seen.contains(t.tsym)) {
1976 //degenerate case in which we have a circular
1977 //class hierarchy - because of ill-formed classfiles
1978 return null;
1979 }
1980 seen = seen.prepend(t.tsym);
1981 return t.tsym;
1982 }
1983 };
1984 }
1985
1986 /** Find unqualified method matching given name, type and value arguments.
1987 * @param env The current environment.
1988 * @param name The method's name.
1989 * @param argtypes The method's value arguments.
1990 * @param typeargtypes The method's type arguments.
1991 * @param allowBoxing Allow boxing conversions of arguments.
1992 * @param useVarargs Box trailing arguments into an array for varargs.
1993 */
1994 Symbol findFun(Env<AttrContext> env, Name name,
1995 List<Type> argtypes, List<Type> typeargtypes,
1996 boolean allowBoxing, boolean useVarargs) {
1997 Symbol bestSoFar = methodNotFound;
1998 Env<AttrContext> env1 = env;
1999 boolean staticOnly = false;
2000 while (env1.outer != null) {
2001 if (isStatic(env1)) staticOnly = true;
2002 Assert.check(env1.info.preferredTreeForDiagnostics == null);
2003 env1.info.preferredTreeForDiagnostics = env.tree;
2004 try {
2005 Symbol sym = findMethod(
2006 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
2007 allowBoxing, useVarargs);
2008 if (sym.exists()) {
2009 if (staticOnly &&
2010 sym.kind == MTH &&
2011 sym.owner.kind == TYP &&
2012 (sym.flags() & STATIC) == 0) return new StaticError(sym);
2013 else return sym;
2014 } else {
2015 bestSoFar = bestOf(bestSoFar, sym);
2016 }
2017 } finally {
2018 env1.info.preferredTreeForDiagnostics = null;
2019 }
2020 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
2021 env1 = env1.outer;
2022 }
2023
2024 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
2025 typeargtypes, allowBoxing, useVarargs);
2026 if (sym.exists())
2027 return sym;
2028
2029 for (Symbol currentSym : env.toplevel.namedImportScope.getSymbolsByName(name)) {
2030 Symbol origin = env.toplevel.namedImportScope.getOrigin(currentSym).owner;
2031 if (currentSym.kind == MTH) {
2032 if (currentSym.owner.type != origin.type)
2033 currentSym = currentSym.clone(origin);
2034 if (!isAccessible(env, origin.type, currentSym))
2035 currentSym = new AccessError(env, origin.type, currentSym);
2036 bestSoFar = selectBest(env, origin.type,
2037 argtypes, typeargtypes,
2038 currentSym, bestSoFar,
2039 allowBoxing, useVarargs);
2040 }
2041 }
2042 if (bestSoFar.exists())
2043 return bestSoFar;
2044
2045 for (Symbol currentSym : env.toplevel.starImportScope.getSymbolsByName(name)) {
2046 Symbol origin = env.toplevel.starImportScope.getOrigin(currentSym).owner;
2047 if (currentSym.kind == MTH) {
2048 if (currentSym.owner.type != origin.type)
2049 currentSym = currentSym.clone(origin);
2050 if (!isAccessible(env, origin.type, currentSym))
2051 currentSym = new AccessError(env, origin.type, currentSym);
2052 bestSoFar = selectBest(env, origin.type,
2053 argtypes, typeargtypes,
2054 currentSym, bestSoFar,
2055 allowBoxing, useVarargs);
2056 }
2057 }
2058 return bestSoFar;
2059 }
2060
2061 /** Load toplevel or member class with given fully qualified name and
2062 * verify that it is accessible.
2063 * @param env The current environment.
2064 * @param name The fully qualified name of the class to be loaded.
2065 */
2066 Symbol loadClass(Env<AttrContext> env, Name name, RecoveryLoadClass recoveryLoadClass) {
2067 try {
2068 ClassSymbol c = finder.loadClass(env.toplevel.modle, name);
2069 return isAccessible(env, c) ? c : new AccessError(env, null, c);
2070 } catch (ClassFinder.BadClassFile err) {
2071 return new BadClassFileError(err);
2072 } catch (CompletionFailure ex) {
2073 Symbol candidate = recoveryLoadClass.loadClass(env, name);
2074
2075 if (candidate != null) {
2076 return candidate;
2077 }
2078
2079 return typeNotFound;
2080 }
2081 }
2082
2083 public interface RecoveryLoadClass {
2084 Symbol loadClass(Env<AttrContext> env, Name name);
2085 }
2086
2087 private final RecoveryLoadClass noRecovery = (env, name) -> null;
2088
2089 private final RecoveryLoadClass doRecoveryLoadClass = new RecoveryLoadClass() {
2090 @Override public Symbol loadClass(Env<AttrContext> env, Name name) {
2091 List<Name> candidates = Convert.classCandidates(name);
2092 return lookupInvisibleSymbol(env, name,
2093 n -> () -> createCompoundIterator(candidates,
2094 c -> syms.getClassesForName(c)
2095 .iterator()),
2096 (ms, n) -> {
2097 for (Name candidate : candidates) {
2098 try {
2099 return finder.loadClass(ms, candidate);
2100 } catch (CompletionFailure cf) {
2101 //ignore
2102 }
2103 }
2104 return null;
2105 }, sym -> sym.kind == Kind.TYP, typeNotFound);
2106 }
2107 };
2108
2109 private final RecoveryLoadClass namedImportScopeRecovery = (env, name) -> {
2110 Scope importScope = env.toplevel.namedImportScope;
2111 Symbol existing = importScope.findFirst(Convert.shortName(name),
2112 sym -> sym.kind == TYP && sym.flatName() == name);
2113
2114 if (existing != null) {
2115 return new InvisibleSymbolError(env, true, existing);
2116 }
2117 return null;
2118 };
2119
2120 private final RecoveryLoadClass starImportScopeRecovery = (env, name) -> {
2121 Scope importScope = env.toplevel.starImportScope;
2122 Symbol existing = importScope.findFirst(Convert.shortName(name),
2123 sym -> sym.kind == TYP && sym.flatName() == name);
2124
2125 if (existing != null) {
2126 try {
2127 existing = finder.loadClass(existing.packge().modle, name);
2128
2129 return new InvisibleSymbolError(env, true, existing);
2130 } catch (CompletionFailure cf) {
2131 //ignore
2132 }
2133 }
2134
2135 return null;
2136 };
2137
2138 Symbol lookupPackage(Env<AttrContext> env, Name name) {
2139 PackageSymbol pack = syms.lookupPackage(env.toplevel.modle, name);
2140
2141 if (allowModules && isImportOnDemand(env, name)) {
2142 if (pack.members().isEmpty()) {
2143 return lookupInvisibleSymbol(env, name, syms::getPackagesForName, syms::enterPackage, sym -> {
2144 sym.complete();
2145 return !sym.members().isEmpty();
2146 }, pack);
2147 }
2148 }
2149
2150 return pack;
2151 }
2152
2153 private boolean isImportOnDemand(Env<AttrContext> env, Name name) {
2154 if (!env.tree.hasTag(IMPORT))
2155 return false;
2156
2157 JCTree qualid = ((JCImport) env.tree).qualid;
2158
2159 if (!qualid.hasTag(SELECT))
2160 return false;
2161
2162 if (TreeInfo.name(qualid) != names.asterisk)
2163 return false;
2164
2165 return TreeInfo.fullName(((JCFieldAccess) qualid).selected) == name;
2166 }
2167
2168 private <S extends Symbol> Symbol lookupInvisibleSymbol(Env<AttrContext> env,
2169 Name name,
2170 Function<Name, Iterable<S>> get,
2171 BiFunction<ModuleSymbol, Name, S> load,
2172 Predicate<S> validate,
2173 Symbol defaultResult) {
2174 //even if a class/package cannot be found in the current module and among packages in modules
2175 //it depends on that are exported for any or this module, the class/package may exist internally
2176 //in some of these modules, or may exist in a module on which this module does not depend.
2177 //Provide better diagnostic in such cases by looking for the class in any module:
2178 Iterable<? extends S> candidates = get.apply(name);
2179
2180 for (S sym : candidates) {
2181 if (validate.test(sym))
2182 return createInvisibleSymbolError(env, sym);
2183 }
2184
2185 Set<ModuleSymbol> recoverableModules = new HashSet<>(syms.getAllModules());
2186
2187 recoverableModules.add(syms.unnamedModule);
2188 recoverableModules.remove(env.toplevel.modle);
2189
2190 for (ModuleSymbol ms : recoverableModules) {
2191 //avoid overly eager completing classes from source-based modules, as those
2192 //may not be completable with the current compiler settings:
2193 if (ms.sourceLocation == null) {
2194 if (ms.classLocation == null) {
2195 ms = moduleFinder.findModule(ms);
2196 }
2197
2198 if (ms.kind != ERR) {
2199 S sym = load.apply(ms, name);
2200
2201 if (sym != null && validate.test(sym)) {
2202 return createInvisibleSymbolError(env, sym);
2203 }
2204 }
2205 }
2206 }
2207
2208 return defaultResult;
2209 }
2210
2211 private Symbol createInvisibleSymbolError(Env<AttrContext> env, Symbol sym) {
2212 if (symbolPackageVisible(env, sym)) {
2213 return new AccessError(env, null, sym);
2214 } else {
2215 return new InvisibleSymbolError(env, false, sym);
2216 }
2217 }
2218
2219 private boolean symbolPackageVisible(Env<AttrContext> env, Symbol sym) {
2220 ModuleSymbol envMod = env.toplevel.modle;
2221 PackageSymbol symPack = sym.packge();
2222 return envMod == symPack.modle ||
2223 envMod.visiblePackages.containsKey(symPack.fullname);
2224 }
2225
2226 /**
2227 * Find a type declared in a scope (not inherited). Return null
2228 * if none is found.
2229 * @param env The current environment.
2230 * @param site The original type from where the selection takes
2231 * place.
2232 * @param name The type's name.
2233 * @param c The class to search for the member type. This is
2234 * always a superclass or implemented interface of
2235 * site's class.
2236 */
2237 Symbol findImmediateMemberType(Env<AttrContext> env,
2238 Type site,
2239 Name name,
2240 TypeSymbol c) {
2241 for (Symbol sym : c.members().getSymbolsByName(name)) {
2242 if (sym.kind == TYP) {
2243 return isAccessible(env, site, sym)
2244 ? sym
2245 : new AccessError(env, site, sym);
2246 }
2247 }
2248 return typeNotFound;
2249 }
2250
2251 /** Find a member type inherited from a superclass or interface.
2252 * @param env The current environment.
2253 * @param site The original type from where the selection takes
2254 * place.
2255 * @param name The type's name.
2256 * @param c The class to search for the member type. This is
2257 * always a superclass or implemented interface of
2258 * site's class.
2259 */
2260 Symbol findInheritedMemberType(Env<AttrContext> env,
2261 Type site,
2262 Name name,
2263 TypeSymbol c) {
2264 Symbol bestSoFar = typeNotFound;
2265 Symbol sym;
2266 Type st = types.supertype(c.type);
2267 if (st != null && st.hasTag(CLASS)) {
2268 sym = findMemberType(env, site, name, st.tsym);
2269 bestSoFar = bestOf(bestSoFar, sym);
2270 }
2271 for (List<Type> l = types.interfaces(c.type);
2272 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
2273 l = l.tail) {
2274 sym = findMemberType(env, site, name, l.head.tsym);
2275 if (!bestSoFar.kind.isResolutionError() &&
2276 !sym.kind.isResolutionError() &&
2277 sym.owner != bestSoFar.owner)
2278 bestSoFar = new AmbiguityError(bestSoFar, sym);
2279 else
2280 bestSoFar = bestOf(bestSoFar, sym);
2281 }
2282 return bestSoFar;
2283 }
2284
2285 /** Find qualified member type.
2286 * @param env The current environment.
2287 * @param site The original type from where the selection takes
2288 * place.
2289 * @param name The type's name.
2290 * @param c The class to search for the member type. This is
2291 * always a superclass or implemented interface of
2292 * site's class.
2293 */
2294 Symbol findMemberType(Env<AttrContext> env,
2295 Type site,
2296 Name name,
2297 TypeSymbol c) {
2298 Symbol sym = findImmediateMemberType(env, site, name, c);
2299
2300 if (sym != typeNotFound)
2301 return sym;
2302
2303 return findInheritedMemberType(env, site, name, c);
2304
2305 }
2306
2307 /** Find a global type in given scope and load corresponding class.
2308 * @param env The current environment.
2309 * @param scope The scope in which to look for the type.
2310 * @param name The type's name.
2311 */
2312 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name, RecoveryLoadClass recoveryLoadClass) {
2313 Symbol bestSoFar = typeNotFound;
2314 for (Symbol s : scope.getSymbolsByName(name)) {
2315 Symbol sym = loadClass(env, s.flatName(), recoveryLoadClass);
2316 if (bestSoFar.kind == TYP && sym.kind == TYP &&
2317 bestSoFar != sym)
2318 return new AmbiguityError(bestSoFar, sym);
2319 else
2320 bestSoFar = bestOf(bestSoFar, sym);
2321 }
2322 return bestSoFar;
2323 }
2324
2325 Symbol findTypeVar(Env<AttrContext> env, Name name, boolean staticOnly) {
2326 for (Symbol sym : env.info.scope.getSymbolsByName(name)) {
2327 if (sym.kind == TYP) {
2328 if (sym.type.hasTag(TYPEVAR) &&
2329 (staticOnly || (isStatic(env) && sym.owner.kind == TYP)))
2330 // if staticOnly is set, it means that we have recursed through a static declaration,
2331 // so type variable symbols should not be accessible. If staticOnly is unset, but
2332 // we are in a static declaration (field or method), we should not allow type-variables
2333 // defined in the enclosing class to "leak" into this context.
2334 return new StaticError(sym);
2335 return sym;
2336 }
2337 }
2338 return typeNotFound;
2339 }
2340
2341 /** Find an unqualified type symbol.
2342 * @param env The current environment.
2343 * @param name The type's name.
2344 */
2345 Symbol findType(Env<AttrContext> env, Name name) {
2346 if (name == names.empty)
2347 return typeNotFound; // do not allow inadvertent "lookup" of anonymous types
2348 Symbol bestSoFar = typeNotFound;
2349 Symbol sym;
2350 boolean staticOnly = false;
2351 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
2352 // First, look for a type variable and the first member type
2353 final Symbol tyvar = findTypeVar(env1, name, staticOnly);
2354 if (isStatic(env1)) staticOnly = true;
2355 sym = findImmediateMemberType(env1, env1.enclClass.sym.type,
2356 name, env1.enclClass.sym);
2357
2358 // Return the type variable if we have it, and have no
2359 // immediate member, OR the type variable is for a method.
2360 if (tyvar != typeNotFound) {
2361 if (env.baseClause || sym == typeNotFound ||
2362 (tyvar.kind == TYP && tyvar.exists() &&
2363 tyvar.owner.kind == MTH)) {
2364 return tyvar;
2365 }
2366 }
2367
2368 // If the environment is a class def, finish up,
2369 // otherwise, do the entire findMemberType
2370 if (sym == typeNotFound)
2371 sym = findInheritedMemberType(env1, env1.enclClass.sym.type,
2372 name, env1.enclClass.sym);
2373
2374 if (staticOnly && sym.kind == TYP &&
2375 sym.type.hasTag(CLASS) &&
2376 sym.type.getEnclosingType().hasTag(CLASS) &&
2377 env1.enclClass.sym.type.isParameterized() &&
2378 sym.type.getEnclosingType().isParameterized())
2379 return new StaticError(sym);
2380 else if (sym.exists()) return sym;
2381 else bestSoFar = bestOf(bestSoFar, sym);
2382
2383 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
2384 if ((encl.sym.flags() & STATIC) != 0)
2385 staticOnly = true;
2386 }
2387
2388 if (!env.tree.hasTag(IMPORT)) {
2389 sym = findGlobalType(env, env.toplevel.namedImportScope, name, namedImportScopeRecovery);
2390 if (sym.exists()) return sym;
2391 else bestSoFar = bestOf(bestSoFar, sym);
2392
2393 sym = findGlobalType(env, env.toplevel.toplevelScope, name, noRecovery);
2394 if (sym.exists()) return sym;
2395 else bestSoFar = bestOf(bestSoFar, sym);
2396
2397 sym = findGlobalType(env, env.toplevel.packge.members(), name, noRecovery);
2398 if (sym.exists()) return sym;
2399 else bestSoFar = bestOf(bestSoFar, sym);
2400
2401 sym = findGlobalType(env, env.toplevel.starImportScope, name, starImportScopeRecovery);
2402 if (sym.exists()) return sym;
2403 else bestSoFar = bestOf(bestSoFar, sym);
2404 }
2405
2406 return bestSoFar;
2407 }
2408
2409 /** Find an unqualified identifier which matches a specified kind set.
2410 * @param pos position on which report warnings, if any;
2411 * null warnings should not be reported
2412 * @param env The current environment.
2413 * @param name The identifier's name.
2414 * @param kind Indicates the possible symbol kinds
2415 * (a subset of VAL, TYP, PCK).
2416 */
2417 Symbol findIdent(DiagnosticPosition pos, Env<AttrContext> env, Name name, KindSelector kind) {
2418 return checkNonExistentType(checkRestrictedType(pos, findIdentInternal(env, name, kind), name));
2419 }
2420
2421 Symbol findIdentInternal(Env<AttrContext> env, Name name, KindSelector kind) {
2422 Symbol bestSoFar = typeNotFound;
2423 Symbol sym;
2424
2425 if (kind.contains(KindSelector.VAL)) {
2426 sym = findVar(env, name);
2427 if (sym.exists()) return sym;
2428 else bestSoFar = bestOf(bestSoFar, sym);
2429 }
2430
2431 if (kind.contains(KindSelector.TYP)) {
2432 sym = findType(env, name);
2433 if (sym.exists()) return sym;
2434 else bestSoFar = bestOf(bestSoFar, sym);
2435 }
2436
2437 if (kind.contains(KindSelector.PCK))
2438 return lookupPackage(env, name);
2439 else return bestSoFar;
2440 }
2441
2442 /** Find an identifier in a package which matches a specified kind set.
2443 * @param pos position on which report warnings, if any;
2444 * null warnings should not be reported
2445 * @param env The current environment.
2446 * @param name The identifier's name.
2447 * @param kind Indicates the possible symbol kinds
2448 * (a nonempty subset of TYP, PCK).
2449 */
2450 Symbol findIdentInPackage(DiagnosticPosition pos,
2451 Env<AttrContext> env, TypeSymbol pck,
2452 Name name, KindSelector kind) {
2453 return checkNonExistentType(checkRestrictedType(pos, findIdentInPackageInternal(env, pck, name, kind), name));
2454 }
2455
2456 Symbol findIdentInPackageInternal(Env<AttrContext> env, TypeSymbol pck,
2457 Name name, KindSelector kind) {
2458 Name fullname = TypeSymbol.formFullName(name, pck);
2459 Symbol bestSoFar = typeNotFound;
2460 if (kind.contains(KindSelector.TYP)) {
2461 RecoveryLoadClass recoveryLoadClass =
2462 allowModules && !kind.contains(KindSelector.PCK) &&
2463 !pck.exists() && !env.info.attributionMode.isSpeculative ?
2464 doRecoveryLoadClass : noRecovery;
2465 Symbol sym = loadClass(env, fullname, recoveryLoadClass);
2466 if (sym.exists()) {
2467 // don't allow programs to use flatnames
2468 if (name == sym.name) return sym;
2469 }
2470 else bestSoFar = bestOf(bestSoFar, sym);
2471 }
2472 if (kind.contains(KindSelector.PCK)) {
2473 return lookupPackage(env, fullname);
2474 }
2475 return bestSoFar;
2476 }
2477
2478 /** Find an identifier among the members of a given type `site'.
2479 * @param pos position on which report warnings, if any;
2480 * null warnings should not be reported
2481 * @param env The current environment.
2482 * @param site The type containing the symbol to be found.
2483 * @param name The identifier's name.
2484 * @param kind Indicates the possible symbol kinds
2485 * (a subset of VAL, TYP).
2486 */
2487 Symbol findIdentInType(DiagnosticPosition pos,
2488 Env<AttrContext> env, Type site,
2489 Name name, KindSelector kind) {
2490 return checkNonExistentType(checkRestrictedType(pos, findIdentInTypeInternal(env, site, name, kind), name));
2491 }
2492
2493 private Symbol checkNonExistentType(Symbol symbol) {
2494 /* Guard against returning a type is not on the class path of the current compilation,
2495 * but *was* on the class path of a separate compilation that produced a class file
2496 * that is on the class path of the current compilation. Such a type will fail completion
2497 * but the completion failure may have been silently swallowed (e.g. missing annotation types)
2498 * with an error stub symbol lingering in the symbol tables.
2499 */
2500 return symbol instanceof ClassSymbol c && c.type.isErroneous() && c.classfile == null ? typeNotFound : symbol;
2501 }
2502
2503 Symbol findIdentInTypeInternal(Env<AttrContext> env, Type site,
2504 Name name, KindSelector kind) {
2505 Symbol bestSoFar = typeNotFound;
2506 Symbol sym;
2507 if (kind.contains(KindSelector.VAL)) {
2508 sym = findField(env, site, name, site.tsym);
2509 if (sym.exists()) return sym;
2510 else bestSoFar = bestOf(bestSoFar, sym);
2511 }
2512
2513 if (kind.contains(KindSelector.TYP)) {
2514 sym = findMemberType(env, site, name, site.tsym);
2515 if (sym.exists()) return sym;
2516 else bestSoFar = bestOf(bestSoFar, sym);
2517 }
2518 return bestSoFar;
2519 }
2520
2521 private Symbol checkRestrictedType(DiagnosticPosition pos, Symbol bestSoFar, Name name) {
2522 if (bestSoFar.kind == TYP || bestSoFar.kind == ABSENT_TYP) {
2523 if (allowLocalVariableTypeInference && name.equals(names.var)) {
2524 bestSoFar = new BadRestrictedTypeError(names.var);
2525 } else if (name.equals(names.yield)) {
2526 if (allowYieldStatement) {
2527 bestSoFar = new BadRestrictedTypeError(names.yield);
2528 } else if (pos != null) {
2529 log.warning(pos, Warnings.IllegalRefToRestrictedType(names.yield));
2530 }
2531 }
2532 }
2533 return bestSoFar;
2534 }
2535
2536 /* ***************************************************************************
2537 * Access checking
2538 * The following methods convert ResolveErrors to ErrorSymbols, issuing
2539 * an error message in the process
2540 ****************************************************************************/
2541
2542 /** If `sym' is a bad symbol: report error and return errSymbol
2543 * else pass through unchanged,
2544 * additional arguments duplicate what has been used in trying to find the
2545 * symbol {@literal (--> flyweight pattern)}. This improves performance since we
2546 * expect misses to happen frequently.
2547 *
2548 * @param sym The symbol that was found, or a ResolveError.
2549 * @param pos The position to use for error reporting.
2550 * @param location The symbol the served as a context for this lookup
2551 * @param site The original type from where the selection took place.
2552 * @param name The symbol's name.
2553 * @param qualified Did we get here through a qualified expression resolution?
2554 * @param argtypes The invocation's value arguments,
2555 * if we looked for a method.
2556 * @param typeargtypes The invocation's type arguments,
2557 * if we looked for a method.
2558 * @param logResolveHelper helper class used to log resolve errors
2559 */
2560 Symbol accessInternal(Symbol sym,
2561 DiagnosticPosition pos,
2562 Symbol location,
2563 Type site,
2564 Name name,
2565 boolean qualified,
2566 List<Type> argtypes,
2567 List<Type> typeargtypes,
2568 LogResolveHelper logResolveHelper) {
2569 if (sym.kind.isResolutionError()) {
2570 ResolveError errSym = (ResolveError)sym.baseSymbol();
2571 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
2572 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes);
2573 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) {
2574 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
2575 }
2576 }
2577 return sym;
2578 }
2579
2580 /**
2581 * Variant of the generalized access routine, to be used for generating method
2582 * resolution diagnostics
2583 */
2584 Symbol accessMethod(Symbol sym,
2585 DiagnosticPosition pos,
2586 Symbol location,
2587 Type site,
2588 Name name,
2589 boolean qualified,
2590 List<Type> argtypes,
2591 List<Type> typeargtypes) {
2592 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper);
2593 }
2594
2595 /** Same as original accessMethod(), but without location.
2596 */
2597 Symbol accessMethod(Symbol sym,
2598 DiagnosticPosition pos,
2599 Type site,
2600 Name name,
2601 boolean qualified,
2602 List<Type> argtypes,
2603 List<Type> typeargtypes) {
2604 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
2605 }
2606
2607 /**
2608 * Variant of the generalized access routine, to be used for generating variable,
2609 * type resolution diagnostics
2610 */
2611 Symbol accessBase(Symbol sym,
2612 DiagnosticPosition pos,
2613 Symbol location,
2614 Type site,
2615 Name name,
2616 boolean qualified) {
2617 return accessInternal(sym, pos, location, site, name, qualified, List.nil(), null, basicLogResolveHelper);
2618 }
2619
2620 /** Same as original accessBase(), but without location.
2621 */
2622 Symbol accessBase(Symbol sym,
2623 DiagnosticPosition pos,
2624 Type site,
2625 Name name,
2626 boolean qualified) {
2627 return accessBase(sym, pos, site.tsym, site, name, qualified);
2628 }
2629
2630 interface LogResolveHelper {
2631 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes);
2632 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes);
2633 }
2634
2635 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() {
2636 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2637 return !site.isErroneous();
2638 }
2639 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2640 return argtypes;
2641 }
2642 };
2643
2644 LogResolveHelper silentLogResolveHelper = new LogResolveHelper() {
2645 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2646 return false;
2647 }
2648 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2649 return argtypes;
2650 }
2651 };
2652
2653 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() {
2654 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2655 return !site.isErroneous() &&
2656 !Type.isErroneous(argtypes) &&
2657 (typeargtypes == null || !Type.isErroneous(typeargtypes));
2658 }
2659 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2660 return argtypes.map(new ResolveDeferredRecoveryMap(AttrMode.SPECULATIVE, accessedSym, currentResolutionContext.step));
2661 }
2662 };
2663
2664 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap {
2665
2666 public ResolveDeferredRecoveryMap(AttrMode mode, Symbol msym, MethodResolutionPhase step) {
2667 deferredAttr.super(mode, msym, step);
2668 }
2669
2670 @Override
2671 protected Type typeOf(DeferredType dt, Type pt) {
2672 Type res = super.typeOf(dt, pt);
2673 if (!res.isErroneous()) {
2674 switch (TreeInfo.skipParens(dt.tree).getTag()) {
2675 case LAMBDA:
2676 case REFERENCE:
2677 return dt;
2678 case CONDEXPR:
2679 return res == Type.recoveryType ?
2680 dt : res;
2681 }
2682 }
2683 return res;
2684 }
2685 }
2686
2687 /** Check that sym is not an abstract method.
2688 */
2689 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
2690 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0)
2691 log.error(pos,
2692 Errors.AbstractCantBeAccessedDirectly(kindName(sym),sym, sym.location()));
2693 }
2694
2695 /* ***************************************************************************
2696 * Name resolution
2697 * Naming conventions are as for symbol lookup
2698 * Unlike the find... methods these methods will report access errors
2699 ****************************************************************************/
2700
2701 /** Resolve an unqualified (non-method) identifier.
2702 * @param pos The position to use for error reporting.
2703 * @param env The environment current at the identifier use.
2704 * @param name The identifier's name.
2705 * @param kind The set of admissible symbol kinds for the identifier.
2706 */
2707 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
2708 Name name, KindSelector kind) {
2709 return accessBase(
2710 findIdent(pos, env, name, kind),
2711 pos, env.enclClass.sym.type, name, false);
2712 }
2713
2714 /** Resolve an unqualified method identifier.
2715 * @param pos The position to use for error reporting.
2716 * @param env The environment current at the method invocation.
2717 * @param name The identifier's name.
2718 * @param argtypes The types of the invocation's value arguments.
2719 * @param typeargtypes The types of the invocation's type arguments.
2720 */
2721 Symbol resolveMethod(DiagnosticPosition pos,
2722 Env<AttrContext> env,
2723 Name name,
2724 List<Type> argtypes,
2725 List<Type> typeargtypes) {
2726 return lookupMethod(env, pos, env.enclClass.sym, resolveMethodCheck,
2727 new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) {
2728 @Override
2729 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2730 return findFun(env, name, argtypes, typeargtypes,
2731 phase.isBoxingRequired(),
2732 phase.isVarargsRequired());
2733 }});
2734 }
2735
2736 /** Resolve a qualified method identifier
2737 * @param pos The position to use for error reporting.
2738 * @param env The environment current at the method invocation.
2739 * @param site The type of the qualifying expression, in which
2740 * identifier is searched.
2741 * @param name The identifier's name.
2742 * @param argtypes The types of the invocation's value arguments.
2743 * @param typeargtypes The types of the invocation's type arguments.
2744 */
2745 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2746 Type site, Name name, List<Type> argtypes,
2747 List<Type> typeargtypes) {
2748 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
2749 }
2750 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2751 Symbol location, Type site, Name name, List<Type> argtypes,
2752 List<Type> typeargtypes) {
2753 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
2754 }
2755 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
2756 DiagnosticPosition pos, Env<AttrContext> env,
2757 Symbol location, Type site, Name name, List<Type> argtypes,
2758 List<Type> typeargtypes) {
2759 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) {
2760 @Override
2761 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2762 return findMethod(env, site, name, argtypes, typeargtypes,
2763 phase.isBoxingRequired(),
2764 phase.isVarargsRequired());
2765 }
2766 @Override
2767 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2768 if (sym.kind.isResolutionError()) {
2769 sym = super.access(env, pos, location, sym);
2770 } else {
2771 MethodSymbol msym = (MethodSymbol)sym;
2772 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) {
2773 env.info.pendingResolutionPhase = BASIC;
2774 return findPolymorphicSignatureInstance(env, sym, argtypes);
2775 }
2776 }
2777 return sym;
2778 }
2779 });
2780 }
2781
2782 /** Find or create an implicit method of exactly the given type (after erasure).
2783 * Searches in a side table, not the main scope of the site.
2784 * This emulates the lookup process required by JSR 292 in JVM.
2785 * @param env Attribution environment
2786 * @param spMethod signature polymorphic method - i.e. MH.invokeExact
2787 * @param argtypes The required argument types
2788 */
2789 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env,
2790 final Symbol spMethod,
2791 List<Type> argtypes) {
2792 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
2793 (MethodSymbol)spMethod, currentResolutionContext, argtypes);
2794 return findPolymorphicSignatureInstance(spMethod, mtype);
2795 }
2796
2797 Symbol findPolymorphicSignatureInstance(final Symbol spMethod,
2798 Type mtype) {
2799 for (Symbol sym : polymorphicSignatureScope.getSymbolsByName(spMethod.name)) {
2800 // Check that there is already a method symbol for the method
2801 // type and owner
2802 if (types.isSameType(mtype, sym.type) &&
2803 spMethod.owner == sym.owner) {
2804 return sym;
2805 }
2806 }
2807
2808 Type spReturnType = spMethod.asType().getReturnType();
2809 if (types.isSameType(spReturnType, syms.objectType)) {
2810 // Polymorphic return, pass through mtype
2811 } else if (!types.isSameType(spReturnType, mtype.getReturnType())) {
2812 // Retain the sig poly method's return type, which differs from that of mtype
2813 // Will result in an incompatible return type error
2814 mtype = new MethodType(mtype.getParameterTypes(),
2815 spReturnType,
2816 mtype.getThrownTypes(),
2817 syms.methodClass);
2818 }
2819
2820 // Create the desired method
2821 // Retain static modifier is to support invocations to
2822 // MethodHandle.linkTo* methods
2823 long flags = ABSTRACT | HYPOTHETICAL |
2824 spMethod.flags() & (Flags.AccessFlags | Flags.STATIC);
2825 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) {
2826 @Override
2827 public Symbol baseSymbol() {
2828 return spMethod;
2829 }
2830 };
2831 if (!mtype.isErroneous()) { // Cache only if kosher.
2832 polymorphicSignatureScope.enter(msym);
2833 }
2834 return msym;
2835 }
2836
2837 /** Resolve a qualified method identifier, throw a fatal error if not
2838 * found.
2839 * @param pos The position to use for error reporting.
2840 * @param env The environment current at the method invocation.
2841 * @param site The type of the qualifying expression, in which
2842 * identifier is searched.
2843 * @param name The identifier's name.
2844 * @param argtypes The types of the invocation's value arguments.
2845 * @param typeargtypes The types of the invocation's type arguments.
2846 */
2847 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
2848 Type site, Name name,
2849 List<Type> argtypes,
2850 List<Type> typeargtypes) {
2851 MethodResolutionContext resolveContext = new MethodResolutionContext();
2852 resolveContext.internalResolution = true;
2853 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
2854 site, name, argtypes, typeargtypes);
2855 if (sym.kind == MTH) return (MethodSymbol)sym;
2856 else throw new FatalError(
2857 diags.fragment(Fragments.FatalErrCantLocateMeth(name)));
2858 }
2859
2860 /** Resolve constructor.
2861 * @param pos The position to use for error reporting.
2862 * @param env The environment current at the constructor invocation.
2863 * @param site The type of class for which a constructor is searched.
2864 * @param argtypes The types of the constructor invocation's value
2865 * arguments.
2866 * @param typeargtypes The types of the constructor invocation's type
2867 * arguments.
2868 */
2869 Symbol resolveConstructor(DiagnosticPosition pos,
2870 Env<AttrContext> env,
2871 Type site,
2872 List<Type> argtypes,
2873 List<Type> typeargtypes) {
2874 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
2875 }
2876
2877 private Symbol resolveConstructor(MethodResolutionContext resolveContext,
2878 final DiagnosticPosition pos,
2879 Env<AttrContext> env,
2880 Type site,
2881 List<Type> argtypes,
2882 List<Type> typeargtypes) {
2883 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2884 @Override
2885 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2886 return findConstructor(pos, env, site, argtypes, typeargtypes,
2887 phase.isBoxingRequired(),
2888 phase.isVarargsRequired());
2889 }
2890 });
2891 }
2892
2893 /** Resolve a constructor, throw a fatal error if not found.
2894 * @param pos The position to use for error reporting.
2895 * @param env The environment current at the method invocation.
2896 * @param site The type to be constructed.
2897 * @param argtypes The types of the invocation's value arguments.
2898 * @param typeargtypes The types of the invocation's type arguments.
2899 */
2900 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2901 Type site,
2902 List<Type> argtypes,
2903 List<Type> typeargtypes) {
2904 MethodResolutionContext resolveContext = new MethodResolutionContext();
2905 resolveContext.internalResolution = true;
2906 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
2907 if (sym.kind == MTH) return (MethodSymbol)sym;
2908 else throw new FatalError(
2909 diags.fragment(Fragments.FatalErrCantLocateCtor(site)));
2910 }
2911
2912 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2913 Type site, List<Type> argtypes,
2914 List<Type> typeargtypes,
2915 boolean allowBoxing,
2916 boolean useVarargs) {
2917 Symbol sym = findMethod(env, site,
2918 names.init, argtypes,
2919 typeargtypes, allowBoxing,
2920 useVarargs);
2921 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2922 chk.checkPreview(pos, env.info.scope.owner, sym);
2923 return sym;
2924 }
2925
2926 /** Resolve constructor using diamond inference.
2927 * @param pos The position to use for error reporting.
2928 * @param env The environment current at the constructor invocation.
2929 * @param site The type of class for which a constructor is searched.
2930 * The scope of this class has been touched in attribution.
2931 * @param argtypes The types of the constructor invocation's value
2932 * arguments.
2933 * @param typeargtypes The types of the constructor invocation's type
2934 * arguments.
2935 */
2936 Symbol resolveDiamond(DiagnosticPosition pos,
2937 Env<AttrContext> env,
2938 Type site,
2939 List<Type> argtypes,
2940 List<Type> typeargtypes) {
2941 return lookupMethod(env, pos, site.tsym, resolveMethodCheck,
2942 new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2943 @Override
2944 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2945 return findDiamond(pos, env, site, argtypes, typeargtypes,
2946 phase.isBoxingRequired(),
2947 phase.isVarargsRequired());
2948 }
2949 @Override
2950 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2951 if (sym.kind.isResolutionError()) {
2952 if (sym.kind != WRONG_MTH &&
2953 sym.kind != WRONG_MTHS) {
2954 sym = super.access(env, pos, location, sym);
2955 } else {
2956 sym = new DiamondError(sym, currentResolutionContext);
2957 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes);
2958 env.info.pendingResolutionPhase = currentResolutionContext.step;
2959 }
2960 }
2961 return sym;
2962 }});
2963 }
2964
2965 /** Find the constructor using diamond inference and do some checks(deprecated and preview).
2966 * @param pos The position to use for error reporting.
2967 * @param env The environment current at the constructor invocation.
2968 * @param site The type of class for which a constructor is searched.
2969 * The scope of this class has been touched in attribution.
2970 * @param argtypes The types of the constructor invocation's value arguments.
2971 * @param typeargtypes The types of the constructor invocation's type arguments.
2972 * @param allowBoxing Allow boxing conversions of arguments.
2973 * @param useVarargs Box trailing arguments into an array for varargs.
2974 */
2975 private Symbol findDiamond(DiagnosticPosition pos,
2976 Env<AttrContext> env,
2977 Type site,
2978 List<Type> argtypes,
2979 List<Type> typeargtypes,
2980 boolean allowBoxing,
2981 boolean useVarargs) {
2982 Symbol sym = findDiamond(env, site, argtypes, typeargtypes, allowBoxing, useVarargs);
2983 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2984 chk.checkPreview(pos, env.info.scope.owner, sym);
2985 return sym;
2986 }
2987
2988 /** This method scans all the constructor symbol in a given class scope -
2989 * assuming that the original scope contains a constructor of the kind:
2990 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
2991 * a method check is executed against the modified constructor type:
2992 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond
2993 * inference. The inferred return type of the synthetic constructor IS
2994 * the inferred type for the diamond operator.
2995 */
2996 private Symbol findDiamond(Env<AttrContext> env,
2997 Type site,
2998 List<Type> argtypes,
2999 List<Type> typeargtypes,
3000 boolean allowBoxing,
3001 boolean useVarargs) {
3002 Symbol bestSoFar = methodNotFound;
3003 TypeSymbol tsym = site.tsym.isInterface() ? syms.objectType.tsym : site.tsym;
3004 for (final Symbol sym : tsym.members().getSymbolsByName(names.init)) {
3005 //- System.out.println(" e " + e.sym);
3006 if (sym.kind == MTH &&
3007 (sym.flags_field & SYNTHETIC) == 0) {
3008 List<Type> oldParams = sym.type.hasTag(FORALL) ?
3009 ((ForAll)sym.type).tvars :
3010 List.nil();
3011 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
3012 types.createMethodTypeWithReturn(sym.type.asMethodType(), site));
3013 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) {
3014 @Override
3015 public Symbol baseSymbol() {
3016 return sym;
3017 }
3018 };
3019 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
3020 newConstr,
3021 bestSoFar,
3022 allowBoxing,
3023 useVarargs);
3024 }
3025 }
3026 return bestSoFar;
3027 }
3028
3029 Symbol getMemberReference(DiagnosticPosition pos,
3030 Env<AttrContext> env,
3031 JCMemberReference referenceTree,
3032 Type site,
3033 Name name) {
3034
3035 site = types.capture(site);
3036
3037 ReferenceLookupHelper lookupHelper = makeReferenceLookupHelper(
3038 referenceTree, site, name, List.nil(), null, VARARITY);
3039
3040 Env<AttrContext> newEnv = env.dup(env.tree, env.info.dup());
3041 Symbol sym = lookupMethod(newEnv, env.tree.pos(), site.tsym,
3042 nilMethodCheck, lookupHelper);
3043
3044 env.info.pendingResolutionPhase = newEnv.info.pendingResolutionPhase;
3045
3046 return sym;
3047 }
3048
3049 ReferenceLookupHelper makeReferenceLookupHelper(JCMemberReference referenceTree,
3050 Type site,
3051 Name name,
3052 List<Type> argtypes,
3053 List<Type> typeargtypes,
3054 MethodResolutionPhase maxPhase) {
3055 if (!name.equals(names.init)) {
3056 //method reference
3057 return new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
3058 } else if (site.hasTag(ARRAY)) {
3059 //array constructor reference
3060 return new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
3061 } else {
3062 //class constructor reference
3063 return new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
3064 }
3065 }
3066
3067 /**
3068 * Resolution of member references is typically done as a single
3069 * overload resolution step, where the argument types A are inferred from
3070 * the target functional descriptor.
3071 *
3072 * If the member reference is a method reference with a type qualifier,
3073 * a two-step lookup process is performed. The first step uses the
3074 * expected argument list A, while the second step discards the first
3075 * type from A (which is treated as a receiver type).
3076 *
3077 * There are two cases in which inference is performed: (i) if the member
3078 * reference is a constructor reference and the qualifier type is raw - in
3079 * which case diamond inference is used to infer a parameterization for the
3080 * type qualifier; (ii) if the member reference is an unbound reference
3081 * where the type qualifier is raw - in that case, during the unbound lookup
3082 * the receiver argument type is used to infer an instantiation for the raw
3083 * qualifier type.
3084 *
3085 * When a multi-step resolution process is exploited, the process of picking
3086 * the resulting symbol is delegated to an helper class {@link com.sun.tools.javac.comp.Resolve.ReferenceChooser}.
3087 *
3088 * This routine returns a pair (T,S), where S is the member reference symbol,
3089 * and T is the type of the class in which S is defined. This is necessary as
3090 * the type T might be dynamically inferred (i.e. if constructor reference
3091 * has a raw qualifier).
3092 */
3093 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(Env<AttrContext> env,
3094 JCMemberReference referenceTree,
3095 Type site,
3096 Name name,
3097 List<Type> argtypes,
3098 List<Type> typeargtypes,
3099 Type descriptor,
3100 MethodCheck methodCheck,
3101 InferenceContext inferenceContext,
3102 ReferenceChooser referenceChooser) {
3103
3104 //step 1 - bound lookup
3105 ReferenceLookupHelper boundLookupHelper = makeReferenceLookupHelper(
3106 referenceTree, site, name, argtypes, typeargtypes, VARARITY);
3107 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup());
3108 MethodResolutionContext boundSearchResolveContext = new MethodResolutionContext();
3109 boundSearchResolveContext.methodCheck = methodCheck;
3110 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(),
3111 site.tsym, boundSearchResolveContext, boundLookupHelper);
3112 boolean isStaticSelector = TreeInfo.isStaticSelector(referenceTree.expr, names);
3113 ReferenceLookupResult boundRes = new ReferenceLookupResult(boundSym, boundSearchResolveContext, isStaticSelector);
3114 if (dumpMethodReferenceSearchResults) {
3115 dumpMethodReferenceSearchResults(referenceTree, boundSearchResolveContext, boundSym, true);
3116 }
3117
3118 //step 2 - unbound lookup
3119 Symbol unboundSym = methodNotFound;
3120 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup());
3121 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup(inferenceContext);
3122 ReferenceLookupResult unboundRes = referenceNotFound;
3123 if (unboundLookupHelper != null) {
3124 MethodResolutionContext unboundSearchResolveContext =
3125 new MethodResolutionContext();
3126 unboundSearchResolveContext.methodCheck = methodCheck;
3127 unboundSym = lookupMethod(unboundEnv, env.tree.pos(),
3128 site.tsym, unboundSearchResolveContext, unboundLookupHelper);
3129 unboundRes = new ReferenceLookupResult(unboundSym, unboundSearchResolveContext, isStaticSelector);
3130 if (dumpMethodReferenceSearchResults) {
3131 dumpMethodReferenceSearchResults(referenceTree, unboundSearchResolveContext, unboundSym, false);
3132 }
3133 }
3134
3135 //merge results
3136 Pair<Symbol, ReferenceLookupHelper> res;
3137 ReferenceLookupResult bestRes = referenceChooser.result(boundRes, unboundRes);
3138 res = new Pair<>(bestRes.sym,
3139 bestRes == unboundRes ? unboundLookupHelper : boundLookupHelper);
3140 env.info.pendingResolutionPhase = bestRes == unboundRes ?
3141 unboundEnv.info.pendingResolutionPhase :
3142 boundEnv.info.pendingResolutionPhase;
3143
3144 if (!res.fst.kind.isResolutionError()) {
3145 //handle sigpoly method references
3146 MethodSymbol msym = (MethodSymbol)res.fst;
3147 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) {
3148 env.info.pendingResolutionPhase = BASIC;
3149 res = new Pair<>(findPolymorphicSignatureInstance(msym, descriptor), res.snd);
3150 }
3151 }
3152
3153 return res;
3154 }
3155
3156 private void dumpMethodReferenceSearchResults(JCMemberReference referenceTree,
3157 MethodResolutionContext resolutionContext,
3158 Symbol bestSoFar,
3159 boolean bound) {
3160 ListBuffer<JCDiagnostic> subDiags = new ListBuffer<>();
3161 int pos = 0;
3162 int mostSpecificPos = -1;
3163 for (Candidate c : resolutionContext.candidates) {
3164 if (resolutionContext.step != c.step || !c.isApplicable()) {
3165 continue;
3166 } else {
3167 JCDiagnostic subDiag = null;
3168 if (c.sym.type.hasTag(FORALL)) {
3169 subDiag = diags.fragment(Fragments.PartialInstSig(c.mtype));
3170 }
3171
3172 String key = subDiag == null ?
3173 "applicable.method.found.2" :
3174 "applicable.method.found.3";
3175 subDiags.append(diags.fragment(key, pos,
3176 c.sym.isStatic() ? Fragments.Static : Fragments.NonStatic, c.sym, subDiag));
3177 if (c.sym == bestSoFar)
3178 mostSpecificPos = pos;
3179 pos++;
3180 }
3181 }
3182 JCDiagnostic main = diags.note(
3183 log.currentSource(),
3184 referenceTree,
3185 "method.ref.search.results.multi",
3186 bound ? Fragments.Bound : Fragments.Unbound,
3187 referenceTree.toString(), mostSpecificPos);
3188 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
3189 log.report(d);
3190 }
3191
3192 /**
3193 * This class is used to represent a method reference lookup result. It keeps track of two
3194 * things: (i) the symbol found during a method reference lookup and (ii) the static kind
3195 * of the lookup (see {@link com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind}).
3196 */
3197 static class ReferenceLookupResult {
3198
3199 /**
3200 * Static kind associated with a method reference lookup. Erroneous lookups end up with
3201 * the UNDEFINED kind; successful lookups will end up with either STATIC, NON_STATIC,
3202 * depending on whether all applicable candidates are static or non-static methods,
3203 * respectively. If a successful lookup has both static and non-static applicable methods,
3204 * its kind is set to BOTH.
3205 */
3206 enum StaticKind {
3207 STATIC,
3208 NON_STATIC,
3209 BOTH,
3210 UNDEFINED;
3211
3212 /**
3213 * Retrieve the static kind associated with a given (method) symbol.
3214 */
3215 static StaticKind from(Symbol s) {
3216 return s.isStatic() ?
3217 STATIC : NON_STATIC;
3218 }
3219
3220 /**
3221 * Merge two static kinds together.
3222 */
3223 static StaticKind reduce(StaticKind sk1, StaticKind sk2) {
3224 if (sk1 == UNDEFINED) {
3225 return sk2;
3226 } else if (sk2 == UNDEFINED) {
3227 return sk1;
3228 } else {
3229 return sk1 == sk2 ? sk1 : BOTH;
3230 }
3231 }
3232 }
3233
3234 /** The static kind. */
3235 StaticKind staticKind;
3236
3237 /** The lookup result. */
3238 Symbol sym;
3239
3240 ReferenceLookupResult(Symbol sym, MethodResolutionContext resolutionContext, boolean isStaticSelector) {
3241 this(sym, staticKind(sym, resolutionContext, isStaticSelector));
3242 }
3243
3244 private ReferenceLookupResult(Symbol sym, StaticKind staticKind) {
3245 this.staticKind = staticKind;
3246 this.sym = sym;
3247 }
3248
3249 private static StaticKind staticKind(Symbol sym, MethodResolutionContext resolutionContext, boolean isStaticSelector) {
3250 if (sym.kind == MTH && !isStaticSelector) {
3251 return StaticKind.from(sym);
3252 } else if (sym.kind == MTH || sym.kind == AMBIGUOUS) {
3253 return resolutionContext.candidates.stream()
3254 .filter(c -> c.isApplicable() && c.step == resolutionContext.step)
3255 .map(c -> StaticKind.from(c.sym))
3256 .reduce(StaticKind::reduce)
3257 .orElse(StaticKind.UNDEFINED);
3258 } else {
3259 return StaticKind.UNDEFINED;
3260 }
3261 }
3262
3263 /**
3264 * Does this result corresponds to a successful lookup (i.e. one where a method has been found?)
3265 */
3266 boolean isSuccess() {
3267 return staticKind != StaticKind.UNDEFINED;
3268 }
3269
3270 /**
3271 * Does this result have given static kind?
3272 */
3273 boolean hasKind(StaticKind sk) {
3274 return this.staticKind == sk;
3275 }
3276
3277 /**
3278 * Error recovery helper: can this lookup result be ignored (for the purpose of returning
3279 * some 'better' result) ?
3280 */
3281 boolean canIgnore() {
3282 switch (sym.kind) {
3283 case ABSENT_MTH:
3284 return true;
3285 case WRONG_MTH:
3286 InapplicableSymbolError errSym =
3287 (InapplicableSymbolError)sym.baseSymbol();
3288 return new Template(MethodCheckDiag.ARITY_MISMATCH.regex())
3289 .matches(errSym.errCandidate().snd);
3290 case WRONG_MTHS:
3291 InapplicableSymbolsError errSyms =
3292 (InapplicableSymbolsError)sym.baseSymbol();
3293 return errSyms.filterCandidates(errSyms.mapCandidates()).isEmpty();
3294 default:
3295 return false;
3296 }
3297 }
3298
3299 static ReferenceLookupResult error(Symbol sym) {
3300 return new ReferenceLookupResult(sym, StaticKind.UNDEFINED);
3301 }
3302 }
3303
3304 /**
3305 * This abstract class embodies the logic that converts one (bound lookup) or two (unbound lookup)
3306 * {@code ReferenceLookupResult} objects into a {@code Symbol}, which is then regarded as the
3307 * result of method reference resolution.
3308 */
3309 abstract class ReferenceChooser {
3310 /**
3311 * Generate a result from a pair of lookup result objects. This method delegates to the
3312 * appropriate result generation routine.
3313 */
3314 ReferenceLookupResult result(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3315 return unboundRes != referenceNotFound ?
3316 unboundResult(boundRes, unboundRes) :
3317 boundResult(boundRes);
3318 }
3319
3320 /**
3321 * Generate a symbol from a given bound lookup result.
3322 */
3323 abstract ReferenceLookupResult boundResult(ReferenceLookupResult boundRes);
3324
3325 /**
3326 * Generate a symbol from a pair of bound/unbound lookup results.
3327 */
3328 abstract ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes);
3329 }
3330
3331 /**
3332 * This chooser implements the selection strategy used during a full lookup; this logic
3333 * is described in JLS SE 8 (15.3.2).
3334 */
3335 ReferenceChooser basicReferenceChooser = new ReferenceChooser() {
3336
3337 @Override
3338 ReferenceLookupResult boundResult(ReferenceLookupResult boundRes) {
3339 return !boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC) ?
3340 boundRes : //the search produces a non-static method
3341 ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.sym, false));
3342 }
3343
3344 @Override
3345 ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3346 if (boundRes.isSuccess() && boundRes.sym.isStatic() &&
3347 (!unboundRes.isSuccess() || unboundRes.hasKind(StaticKind.STATIC))) {
3348 //the first search produces a static method and no non-static method is applicable
3349 //during the second search
3350 return boundRes;
3351 } else if (unboundRes.isSuccess() && !unboundRes.sym.isStatic() &&
3352 (!boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC))) {
3353 //the second search produces a non-static method and no static method is applicable
3354 //during the first search
3355 return unboundRes;
3356 } else if (boundRes.isSuccess() && unboundRes.isSuccess()) {
3357 //both searches produce some result; ambiguity (error recovery)
3358 return ReferenceLookupResult.error(ambiguityError(boundRes.sym, unboundRes.sym));
3359 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) {
3360 //Both searches failed to produce a result with correct staticness (i.e. first search
3361 //produces an non-static method). Alternatively, a given search produced a result
3362 //with the right staticness, but the other search has applicable methods with wrong
3363 //staticness (error recovery)
3364 return ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.isSuccess() ?
3365 boundRes.sym : unboundRes.sym, true));
3366 } else {
3367 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery)
3368 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ?
3369 unboundRes : boundRes;
3370 }
3371 }
3372 };
3373
3374 /**
3375 * This chooser implements the selection strategy used during an arity-based lookup; this logic
3376 * is described in JLS SE 8 (15.12.2.1).
3377 */
3378 ReferenceChooser structuralReferenceChooser = new ReferenceChooser() {
3379
3380 @Override
3381 ReferenceLookupResult boundResult(ReferenceLookupResult boundRes) {
3382 return (!boundRes.isSuccess() || !boundRes.hasKind(StaticKind.STATIC)) ?
3383 boundRes : //the search has at least one applicable non-static method
3384 ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.sym, false));
3385 }
3386
3387 @Override
3388 ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3389 if (boundRes.isSuccess() && !boundRes.hasKind(StaticKind.NON_STATIC)) {
3390 //the first search has at least one applicable static method
3391 return boundRes;
3392 } else if (unboundRes.isSuccess() && !unboundRes.hasKind(StaticKind.STATIC)) {
3393 //the second search has at least one applicable non-static method
3394 return unboundRes;
3395 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) {
3396 //either the first search produces a non-static method, or second search produces
3397 //a non-static method (error recovery)
3398 return ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.isSuccess() ?
3399 boundRes.sym : unboundRes.sym, true));
3400 } else {
3401 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery)
3402 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ?
3403 unboundRes : boundRes;
3404 }
3405 }
3406 };
3407
3408 /**
3409 * Helper for defining custom method-like lookup logic; a lookup helper
3410 * provides hooks for (i) the actual lookup logic and (ii) accessing the
3411 * lookup result (this step might result in compiler diagnostics to be generated)
3412 */
3413 abstract class LookupHelper {
3414
3415 /** name of the symbol to lookup */
3416 Name name;
3417
3418 /** location in which the lookup takes place */
3419 Type site;
3420
3421 /** actual types used during the lookup */
3422 List<Type> argtypes;
3423
3424 /** type arguments used during the lookup */
3425 List<Type> typeargtypes;
3426
3427 /** Max overload resolution phase handled by this helper */
3428 MethodResolutionPhase maxPhase;
3429
3430 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3431 this.name = name;
3432 this.site = site;
3433 this.argtypes = argtypes;
3434 this.typeargtypes = typeargtypes;
3435 this.maxPhase = maxPhase;
3436 }
3437
3438 /**
3439 * Should lookup stop at given phase with given result
3440 */
3441 final boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
3442 return phase.ordinal() > maxPhase.ordinal() ||
3443 !sym.kind.isResolutionError() || sym.kind == AMBIGUOUS || sym.kind == STATICERR;
3444 }
3445
3446 /**
3447 * Search for a symbol under a given overload resolution phase - this method
3448 * is usually called several times, once per each overload resolution phase
3449 */
3450 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase);
3451
3452 /**
3453 * Dump overload resolution info
3454 */
3455 void debug(DiagnosticPosition pos, Symbol sym) {
3456 //do nothing
3457 }
3458
3459 /**
3460 * Validate the result of the lookup
3461 */
3462 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym);
3463 }
3464
3465 abstract class BasicLookupHelper extends LookupHelper {
3466
3467 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) {
3468 this(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY);
3469 }
3470
3471 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3472 super(name, site, argtypes, typeargtypes, maxPhase);
3473 }
3474
3475 @Override
3476 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3477 Symbol sym = doLookup(env, phase);
3478 if (sym.kind == AMBIGUOUS) {
3479 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
3480 sym = a_err.mergeAbstracts(site);
3481 }
3482 return sym;
3483 }
3484
3485 abstract Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase);
3486
3487 @Override
3488 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
3489 if (sym.kind.isResolutionError()) {
3490 //if nothing is found return the 'first' error
3491 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes);
3492 }
3493 return sym;
3494 }
3495
3496 @Override
3497 void debug(DiagnosticPosition pos, Symbol sym) {
3498 reportVerboseResolutionDiagnostic(pos, name, site, argtypes, typeargtypes, sym);
3499 }
3500 }
3501
3502 /**
3503 * Helper class for member reference lookup. A reference lookup helper
3504 * defines the basic logic for member reference lookup; a method gives
3505 * access to an 'unbound' helper used to perform an unbound member
3506 * reference lookup.
3507 */
3508 abstract class ReferenceLookupHelper extends LookupHelper {
3509
3510 /** The member reference tree */
3511 JCMemberReference referenceTree;
3512
3513 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3514 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3515 super(name, site, argtypes, typeargtypes, maxPhase);
3516 this.referenceTree = referenceTree;
3517 }
3518
3519 /**
3520 * Returns an unbound version of this lookup helper. By default, this
3521 * method returns an dummy lookup helper.
3522 */
3523 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3524 return null;
3525 }
3526
3527 /**
3528 * Get the kind of the member reference
3529 */
3530 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym);
3531
3532 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
3533 if (sym.kind == AMBIGUOUS) {
3534 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
3535 sym = a_err.mergeAbstracts(site);
3536 }
3537 //skip error reporting
3538 return sym;
3539 }
3540 }
3541
3542 /**
3543 * Helper class for method reference lookup. The lookup logic is based
3544 * upon Resolve.findMethod; in certain cases, this helper class has a
3545 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper).
3546 * In such cases, non-static lookup results are thrown away.
3547 */
3548 class MethodReferenceLookupHelper extends ReferenceLookupHelper {
3549
3550 /** The original method reference lookup site. */
3551 Type originalSite;
3552
3553 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3554 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3555 super(referenceTree, name, types.skipTypeVars(site, true), argtypes, typeargtypes, maxPhase);
3556 this.originalSite = site;
3557 }
3558
3559 @Override
3560 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3561 return findMethod(env, site, name, argtypes, typeargtypes,
3562 phase.isBoxingRequired(), phase.isVarargsRequired());
3563 }
3564
3565 @Override
3566 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3567 if (TreeInfo.isStaticSelector(referenceTree.expr, names)) {
3568 if (argtypes.nonEmpty() &&
3569 (argtypes.head.hasTag(NONE) ||
3570 types.isSubtypeUnchecked(inferenceContext.asUndetVar(argtypes.head), originalSite))) {
3571 return new UnboundMethodReferenceLookupHelper(referenceTree, name,
3572 originalSite, argtypes, typeargtypes, maxPhase);
3573 } else {
3574 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) {
3575 @Override
3576 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3577 return this;
3578 }
3579
3580 @Override
3581 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3582 return methodNotFound;
3583 }
3584
3585 @Override
3586 ReferenceKind referenceKind(Symbol sym) {
3587 Assert.error();
3588 return null;
3589 }
3590 };
3591 }
3592 } else {
3593 return super.unboundLookup(inferenceContext);
3594 }
3595 }
3596
3597 @Override
3598 ReferenceKind referenceKind(Symbol sym) {
3599 if (sym.isStatic()) {
3600 return ReferenceKind.STATIC;
3601 } else {
3602 Name selName = TreeInfo.name(referenceTree.getQualifierExpression());
3603 return selName != null && selName == names._super ?
3604 ReferenceKind.SUPER :
3605 ReferenceKind.BOUND;
3606 }
3607 }
3608 }
3609
3610 /**
3611 * Helper class for unbound method reference lookup. Essentially the same
3612 * as the basic method reference lookup helper; main difference is that static
3613 * lookup results are thrown away. If qualifier type is raw, an attempt to
3614 * infer a parameterized type is made using the first actual argument (that
3615 * would otherwise be ignored during the lookup).
3616 */
3617 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper {
3618
3619 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3620 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3621 super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase);
3622 if (site.isRaw() && !argtypes.head.hasTag(NONE)) {
3623 Type asSuperSite = types.asSuper(argtypes.head, site.tsym);
3624 this.site = types.skipTypeVars(asSuperSite, true);
3625 }
3626 }
3627
3628 @Override
3629 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3630 return this;
3631 }
3632
3633 @Override
3634 ReferenceKind referenceKind(Symbol sym) {
3635 return ReferenceKind.UNBOUND;
3636 }
3637 }
3638
3639 /**
3640 * Helper class for array constructor lookup; an array constructor lookup
3641 * is simulated by looking up a method that returns the array type specified
3642 * as qualifier, and that accepts a single int parameter (size of the array).
3643 */
3644 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper {
3645
3646 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
3647 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3648 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
3649 }
3650
3651 @Override
3652 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3653 WriteableScope sc = WriteableScope.create(syms.arrayClass);
3654 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym);
3655 arrayConstr.type = new MethodType(List.of(syms.intType), site, List.nil(), syms.methodClass);
3656 sc.enter(arrayConstr);
3657 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false);
3658 }
3659
3660 @Override
3661 ReferenceKind referenceKind(Symbol sym) {
3662 return ReferenceKind.ARRAY_CTOR;
3663 }
3664 }
3665
3666 /**
3667 * Helper class for constructor reference lookup. The lookup logic is based
3668 * upon either Resolve.findMethod or Resolve.findDiamond - depending on
3669 * whether the constructor reference needs diamond inference (this is the case
3670 * if the qualifier type is raw). A special erroneous symbol is returned
3671 * if the lookup returns the constructor of an inner class and there's no
3672 * enclosing instance in scope.
3673 */
3674 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper {
3675
3676 boolean needsInference;
3677
3678 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
3679 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3680 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
3681 if (site.isRaw()) {
3682 this.site = new ClassType(site.getEnclosingType(),
3683 !(site.tsym.isInner() && site.getEnclosingType().isRaw()) ?
3684 site.tsym.type.getTypeArguments() : List.nil(), site.tsym, site.getMetadata());
3685 needsInference = true;
3686 }
3687 }
3688
3689 @Override
3690 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3691 Symbol sym = needsInference ?
3692 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) :
3693 findMethod(env, site, name, argtypes, typeargtypes,
3694 phase.isBoxingRequired(), phase.isVarargsRequired());
3695 return enclosingInstanceMissing(env, site) ? new BadConstructorReferenceError(sym) : sym;
3696 }
3697
3698 @Override
3699 ReferenceKind referenceKind(Symbol sym) {
3700 return site.getEnclosingType().hasTag(NONE) ?
3701 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER;
3702 }
3703 }
3704
3705 /**
3706 * Main overload resolution routine. On each overload resolution step, a
3707 * lookup helper class is used to perform the method/constructor lookup;
3708 * at the end of the lookup, the helper is used to validate the results
3709 * (this last step might trigger overload resolution diagnostics).
3710 */
3711 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, MethodCheck methodCheck, LookupHelper lookupHelper) {
3712 MethodResolutionContext resolveContext = new MethodResolutionContext();
3713 resolveContext.methodCheck = methodCheck;
3714 return lookupMethod(env, pos, location, resolveContext, lookupHelper);
3715 }
3716
3717 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location,
3718 MethodResolutionContext resolveContext, LookupHelper lookupHelper) {
3719 MethodResolutionContext prevResolutionContext = currentResolutionContext;
3720 try {
3721 Symbol bestSoFar = methodNotFound;
3722 currentResolutionContext = resolveContext;
3723 for (MethodResolutionPhase phase : methodResolutionSteps) {
3724 if (lookupHelper.shouldStop(bestSoFar, phase))
3725 break;
3726 MethodResolutionPhase prevPhase = currentResolutionContext.step;
3727 Symbol prevBest = bestSoFar;
3728 currentResolutionContext.step = phase;
3729 Symbol sym = lookupHelper.lookup(env, phase);
3730 lookupHelper.debug(pos, sym);
3731 bestSoFar = phase.mergeResults(bestSoFar, sym);
3732 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase;
3733 }
3734 return lookupHelper.access(env, pos, location, bestSoFar);
3735 } finally {
3736 currentResolutionContext = prevResolutionContext;
3737 }
3738 }
3739
3740 /**
3741 * Resolve `c.name' where name == this or name == super.
3742 * @param pos The position to use for error reporting.
3743 * @param env The environment current at the expression.
3744 * @param c The qualifier.
3745 * @param name The identifier's name.
3746 */
3747 Symbol resolveSelf(DiagnosticPosition pos,
3748 Env<AttrContext> env,
3749 TypeSymbol c,
3750 Name name) {
3751 Env<AttrContext> env1 = env;
3752 boolean staticOnly = false;
3753 while (env1.outer != null) {
3754 if (isStatic(env1)) staticOnly = true;
3755 if (env1.enclClass.sym == c) {
3756 Symbol sym = env1.info.scope.findFirst(name);
3757 if (sym != null) {
3758 if (staticOnly) sym = new StaticError(sym);
3759 return accessBase(sym, pos, env.enclClass.sym.type,
3760 name, true);
3761 }
3762 }
3763 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
3764 env1 = env1.outer;
3765 }
3766 if (c.isInterface() &&
3767 name == names._super && !isStatic(env) &&
3768 types.isDirectSuperInterface(c, env.enclClass.sym)) {
3769 //this might be a default super call if one of the superinterfaces is 'c'
3770 for (Type t : pruneInterfaces(env.enclClass.type)) {
3771 if (t.tsym == c) {
3772 env.info.defaultSuperCallSite = t;
3773 return new VarSymbol(0, names._super,
3774 types.asSuper(env.enclClass.type, c), env.enclClass.sym);
3775 }
3776 }
3777 //find a direct supertype that is a subtype of 'c'
3778 for (Type i : types.directSupertypes(env.enclClass.type)) {
3779 if (i.tsym.isSubClass(c, types) && i.tsym != c) {
3780 log.error(pos,
3781 Errors.IllegalDefaultSuperCall(c,
3782 Fragments.RedundantSupertype(c, i)));
3783 return syms.errSymbol;
3784 }
3785 }
3786 Assert.error();
3787 }
3788 log.error(pos, Errors.NotEnclClass(c));
3789 return syms.errSymbol;
3790 }
3791 //where
3792 private List<Type> pruneInterfaces(Type t) {
3793 ListBuffer<Type> result = new ListBuffer<>();
3794 for (Type t1 : types.interfaces(t)) {
3795 boolean shouldAdd = true;
3796 for (Type t2 : types.directSupertypes(t)) {
3797 if (t1 != t2 && !t2.hasTag(ERROR) && types.isSubtypeNoCapture(t2, t1)) {
3798 shouldAdd = false;
3799 }
3800 }
3801 if (shouldAdd) {
3802 result.append(t1);
3803 }
3804 }
3805 return result.toList();
3806 }
3807
3808
3809 /**
3810 * Resolve `c.this' for an enclosing class c that contains the
3811 * named member.
3812 * @param pos The position to use for error reporting.
3813 * @param env The environment current at the expression.
3814 * @param member The member that must be contained in the result.
3815 */
3816 Symbol resolveSelfContaining(DiagnosticPosition pos,
3817 Env<AttrContext> env,
3818 Symbol member,
3819 boolean isSuperCall) {
3820 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall);
3821 if (sym == null) {
3822 log.error(pos, Errors.EnclClassRequired(member));
3823 return syms.errSymbol;
3824 } else {
3825 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true);
3826 }
3827 }
3828
3829 boolean enclosingInstanceMissing(Env<AttrContext> env, Type type) {
3830 if (type.hasTag(CLASS) && type.getEnclosingType().hasTag(CLASS)) {
3831 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false);
3832 return encl == null || encl.kind.isResolutionError();
3833 }
3834 return false;
3835 }
3836
3837 private Symbol resolveSelfContainingInternal(Env<AttrContext> env,
3838 Symbol member,
3839 boolean isSuperCall) {
3840 Name name = names._this;
3841 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
3842 boolean staticOnly = false;
3843 if (env1 != null) {
3844 while (env1 != null && env1.outer != null) {
3845 if (isStatic(env1)) staticOnly = true;
3846 if (env1.enclClass.sym.isSubClass(member.owner.enclClass(), types)) {
3847 Symbol sym = env1.info.scope.findFirst(name);
3848 if (sym != null) {
3849 if (staticOnly) sym = new StaticError(sym);
3850 return sym;
3851 }
3852 }
3853 if ((env1.enclClass.sym.flags() & STATIC) != 0)
3854 staticOnly = true;
3855 env1 = env1.outer;
3856 }
3857 }
3858 return null;
3859 }
3860
3861 /**
3862 * Resolve an appropriate implicit this instance for t's container.
3863 * JLS 8.8.5.1 and 15.9.2
3864 */
3865 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
3866 return resolveImplicitThis(pos, env, t, false);
3867 }
3868
3869 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
3870 Type thisType = (t.tsym.owner.kind.matches(KindSelector.VAL_MTH)
3871 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
3872 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
3873 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym) {
3874 log.error(pos, Errors.CantRefBeforeCtorCalled("this"));
3875 }
3876 return thisType;
3877 }
3878
3879 /* ***************************************************************************
3880 * ResolveError classes, indicating error situations when accessing symbols
3881 ****************************************************************************/
3882
3883 //used by TransTypes when checking target type of synthetic cast
3884 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) {
3885 AccessError error = new AccessError(env, env.enclClass.type, type.tsym);
3886 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null);
3887 }
3888 //where
3889 private void logResolveError(ResolveError error,
3890 DiagnosticPosition pos,
3891 Symbol location,
3892 Type site,
3893 Name name,
3894 List<Type> argtypes,
3895 List<Type> typeargtypes) {
3896 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
3897 pos, location, site, name, argtypes, typeargtypes);
3898 if (d != null) {
3899 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
3900 log.report(d);
3901 }
3902 }
3903
3904 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
3905
3906 public Object methodArguments(List<Type> argtypes) {
3907 if (argtypes == null || argtypes.isEmpty()) {
3908 return noArgs;
3909 } else {
3910 ListBuffer<Object> diagArgs = new ListBuffer<>();
3911 for (Type t : argtypes) {
3912 if (t.hasTag(DEFERRED)) {
3913 diagArgs.append(((DeferredAttr.DeferredType)t).tree);
3914 } else {
3915 diagArgs.append(t);
3916 }
3917 }
3918 return diagArgs;
3919 }
3920 }
3921
3922 /** check if a type is a subtype of Serializable, if that is available.*/
3923 boolean isSerializable(Type t) {
3924 try {
3925 syms.serializableType.complete();
3926 }
3927 catch (CompletionFailure e) {
3928 return false;
3929 }
3930 return types.isSubtype(t, syms.serializableType);
3931 }
3932
3933 /**
3934 * Root class for resolution errors. Subclass of ResolveError
3935 * represent a different kinds of resolution error - as such they must
3936 * specify how they map into concrete compiler diagnostics.
3937 */
3938 abstract class ResolveError extends Symbol {
3939
3940 /** The name of the kind of error, for debugging only. */
3941 final String debugName;
3942
3943 ResolveError(Kind kind, String debugName) {
3944 super(kind, 0, null, null, null);
3945 this.debugName = debugName;
3946 }
3947
3948 @Override @DefinedBy(Api.LANGUAGE_MODEL)
3949 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
3950 throw new AssertionError();
3951 }
3952
3953 @Override
3954 public String toString() {
3955 return debugName;
3956 }
3957
3958 @Override
3959 public boolean exists() {
3960 return false;
3961 }
3962
3963 @Override
3964 public boolean isStatic() {
3965 return false;
3966 }
3967
3968 /**
3969 * Create an external representation for this erroneous symbol to be
3970 * used during attribution - by default this returns the symbol of a
3971 * brand new error type which stores the original type found
3972 * during resolution.
3973 *
3974 * @param name the name used during resolution
3975 * @param location the location from which the symbol is accessed
3976 */
3977 protected Symbol access(Name name, TypeSymbol location) {
3978 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3979 }
3980
3981 /**
3982 * Create a diagnostic representing this resolution error.
3983 *
3984 * @param dkind The kind of the diagnostic to be created (e.g error).
3985 * @param pos The position to be used for error reporting.
3986 * @param site The original type from where the selection took place.
3987 * @param name The name of the symbol to be resolved.
3988 * @param argtypes The invocation's value arguments,
3989 * if we looked for a method.
3990 * @param typeargtypes The invocation's type arguments,
3991 * if we looked for a method.
3992 */
3993 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3994 DiagnosticPosition pos,
3995 Symbol location,
3996 Type site,
3997 Name name,
3998 List<Type> argtypes,
3999 List<Type> typeargtypes);
4000 }
4001
4002 /**
4003 * This class is the root class of all resolution errors caused by
4004 * an invalid symbol being found during resolution.
4005 */
4006 abstract class InvalidSymbolError extends ResolveError {
4007
4008 /** The invalid symbol found during resolution */
4009 Symbol sym;
4010
4011 InvalidSymbolError(Kind kind, Symbol sym, String debugName) {
4012 super(kind, debugName);
4013 this.sym = sym;
4014 }
4015
4016 @Override
4017 public boolean exists() {
4018 return true;
4019 }
4020
4021 @Override
4022 public String toString() {
4023 return super.toString() + " wrongSym=" + sym;
4024 }
4025
4026 @Override
4027 public Symbol access(Name name, TypeSymbol location) {
4028 if (!sym.kind.isResolutionError() && sym.kind.matches(KindSelector.TYP))
4029 return types.createErrorType(name, location, sym.type).tsym;
4030 else
4031 return sym;
4032 }
4033 }
4034
4035 class BadRestrictedTypeError extends ResolveError {
4036 private final Name typeName;
4037 BadRestrictedTypeError(Name typeName) {
4038 super(Kind.BAD_RESTRICTED_TYPE, "bad var use");
4039 this.typeName = typeName;
4040 }
4041
4042 @Override
4043 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4044 return diags.create(dkind, log.currentSource(), pos, "illegal.ref.to.restricted.type", typeName);
4045 }
4046 }
4047
4048 /**
4049 * InvalidSymbolError error class indicating that a symbol matching a
4050 * given name does not exists in a given site.
4051 */
4052 class SymbolNotFoundError extends ResolveError {
4053
4054 SymbolNotFoundError(Kind kind) {
4055 this(kind, "symbol not found error");
4056 }
4057
4058 SymbolNotFoundError(Kind kind, String debugName) {
4059 super(kind, debugName);
4060 }
4061
4062 @Override
4063 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4064 DiagnosticPosition pos,
4065 Symbol location,
4066 Type site,
4067 Name name,
4068 List<Type> argtypes,
4069 List<Type> typeargtypes) {
4070 argtypes = argtypes == null ? List.nil() : argtypes;
4071 typeargtypes = typeargtypes == null ? List.nil() : typeargtypes;
4072 if (name == names.error)
4073 return null;
4074
4075 boolean hasLocation = false;
4076 if (location == null) {
4077 location = site.tsym;
4078 }
4079 if (!location.name.isEmpty()) {
4080 if (location.kind == PCK && !site.tsym.exists() && location.name != names.java) {
4081 return diags.create(dkind, log.currentSource(), pos,
4082 "doesnt.exist", location);
4083 }
4084 hasLocation = !location.name.equals(names._this) &&
4085 !location.name.equals(names._super);
4086 }
4087 boolean isConstructor = name == names.init;
4088 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : kind.absentKind();
4089 Name idname = isConstructor ? site.tsym.name : name;
4090 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
4091 if (hasLocation) {
4092 return diags.create(dkind, log.currentSource(), pos,
4093 errKey, kindname, idname, //symbol kindname, name
4094 typeargtypes, args(argtypes), //type parameters and arguments (if any)
4095 getLocationDiag(location, site)); //location kindname, type
4096 }
4097 else {
4098 return diags.create(dkind, log.currentSource(), pos,
4099 errKey, kindname, idname, //symbol kindname, name
4100 typeargtypes, args(argtypes)); //type parameters and arguments (if any)
4101 }
4102 }
4103 //where
4104 private Object args(List<Type> args) {
4105 return args.isEmpty() ? args : methodArguments(args);
4106 }
4107
4108 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
4109 String key = "cant.resolve";
4110 String suffix = hasLocation ? ".location" : "";
4111 switch (kindname) {
4112 case METHOD:
4113 case CONSTRUCTOR: {
4114 suffix += ".args";
4115 suffix += hasTypeArgs ? ".params" : "";
4116 }
4117 }
4118 return key + suffix;
4119 }
4120 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
4121 if (location.kind == VAR) {
4122 return diags.fragment(Fragments.Location1(kindName(location),
4123 location,
4124 location.type));
4125 } else {
4126 return diags.fragment(Fragments.Location(typeKindName(site),
4127 site,
4128 null));
4129 }
4130 }
4131 }
4132
4133 /**
4134 * InvalidSymbolError error class indicating that a given symbol
4135 * (either a method, a constructor or an operand) is not applicable
4136 * given an actual arguments/type argument list.
4137 */
4138 class InapplicableSymbolError extends ResolveError {
4139
4140 protected MethodResolutionContext resolveContext;
4141
4142 InapplicableSymbolError(MethodResolutionContext context) {
4143 this(WRONG_MTH, "inapplicable symbol error", context);
4144 }
4145
4146 protected InapplicableSymbolError(Kind kind, String debugName, MethodResolutionContext context) {
4147 super(kind, debugName);
4148 this.resolveContext = context;
4149 }
4150
4151 @Override
4152 public String toString() {
4153 return super.toString();
4154 }
4155
4156 @Override
4157 public boolean exists() {
4158 return true;
4159 }
4160
4161 @Override
4162 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4163 DiagnosticPosition pos,
4164 Symbol location,
4165 Type site,
4166 Name name,
4167 List<Type> argtypes,
4168 List<Type> typeargtypes) {
4169 if (name == names.error)
4170 return null;
4171
4172 Pair<Symbol, JCDiagnostic> c = errCandidate();
4173 Symbol ws = c.fst.asMemberOf(site, types);
4174 UnaryOperator<JCDiagnostic> rewriter = compactMethodDiags ?
4175 d -> MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, c.snd) : null;
4176
4177 // If the problem is due to type arguments, then the method parameters aren't relevant,
4178 // so use the error message that omits them to avoid confusion.
4179 switch (c.snd.getCode()) {
4180 case "compiler.misc.wrong.number.type.args":
4181 case "compiler.misc.explicit.param.do.not.conform.to.bounds":
4182 return diags.create(dkind, log.currentSource(), pos,
4183 "cant.apply.symbol.noargs",
4184 rewriter,
4185 kindName(ws),
4186 ws.name == names.init ? ws.owner.name : ws.name,
4187 kindName(ws.owner),
4188 ws.owner.type,
4189 c.snd);
4190 default:
4191 // Avoid saying "constructor Array in class Array"
4192 if (ws.owner == syms.arrayClass && ws.name == names.init) {
4193 return diags.create(dkind, log.currentSource(), pos,
4194 "cant.apply.array.ctor",
4195 rewriter,
4196 methodArguments(ws.type.getParameterTypes()),
4197 methodArguments(argtypes),
4198 c.snd);
4199 }
4200 return diags.create(dkind, log.currentSource(), pos,
4201 "cant.apply.symbol",
4202 rewriter,
4203 kindName(ws),
4204 ws.name == names.init ? ws.owner.name : ws.name,
4205 methodArguments(ws.type.getParameterTypes()),
4206 methodArguments(argtypes),
4207 kindName(ws.owner),
4208 ws.owner.type,
4209 c.snd);
4210 }
4211 }
4212
4213 @Override
4214 public Symbol access(Name name, TypeSymbol location) {
4215 Pair<Symbol, JCDiagnostic> cand = errCandidate();
4216 TypeSymbol errSymbol = types.createErrorType(name, location, cand != null ? cand.fst.type : syms.errSymbol.type).tsym;
4217 if (cand != null) {
4218 attrRecover.wrongMethodSymbolCandidate(errSymbol, cand.fst, cand.snd);
4219 }
4220 return errSymbol;
4221 }
4222
4223 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4224 Candidate bestSoFar = null;
4225 for (Candidate c : resolveContext.candidates) {
4226 if (c.isApplicable()) continue;
4227 bestSoFar = c;
4228 }
4229 Assert.checkNonNull(bestSoFar);
4230 return new Pair<>(bestSoFar.sym, bestSoFar.details);
4231 }
4232 }
4233
4234 /**
4235 * ResolveError error class indicating that a symbol (either methods, constructors or operand)
4236 * is not applicable given an actual arguments/type argument list.
4237 */
4238 class InapplicableSymbolsError extends InapplicableSymbolError {
4239
4240 InapplicableSymbolsError(MethodResolutionContext context) {
4241 super(WRONG_MTHS, "inapplicable symbols", context);
4242 }
4243
4244 @Override
4245 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4246 DiagnosticPosition pos,
4247 Symbol location,
4248 Type site,
4249 Name name,
4250 List<Type> argtypes,
4251 List<Type> typeargtypes) {
4252 Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates();
4253 Map<Symbol, JCDiagnostic> filteredCandidates = compactMethodDiags ?
4254 filterCandidates(candidatesMap) :
4255 mapCandidates();
4256 if (filteredCandidates.isEmpty()) {
4257 filteredCandidates = candidatesMap;
4258 }
4259 boolean truncatedDiag = candidatesMap.size() != filteredCandidates.size();
4260 if (filteredCandidates.size() > 1) {
4261 JCDiagnostic err = diags.create(dkind,
4262 null,
4263 truncatedDiag ?
4264 EnumSet.of(DiagnosticFlag.COMPRESSED) :
4265 EnumSet.noneOf(DiagnosticFlag.class),
4266 log.currentSource(),
4267 pos,
4268 "cant.apply.symbols",
4269 name == names.init ? KindName.CONSTRUCTOR : kind.absentKind(),
4270 name == names.init ? site.tsym.name : name,
4271 methodArguments(argtypes));
4272 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(filteredCandidates, site));
4273 } else if (filteredCandidates.size() == 1) {
4274 Map.Entry<Symbol, JCDiagnostic> _e =
4275 filteredCandidates.entrySet().iterator().next();
4276 final Pair<Symbol, JCDiagnostic> p = new Pair<>(_e.getKey(), _e.getValue());
4277 JCDiagnostic d = new InapplicableSymbolError(resolveContext) {
4278 @Override
4279 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4280 return p;
4281 }
4282 }.getDiagnostic(dkind, pos,
4283 location, site, name, argtypes, typeargtypes);
4284 if (truncatedDiag) {
4285 d.setFlag(DiagnosticFlag.COMPRESSED);
4286 }
4287 return d;
4288 } else {
4289 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
4290 location, site, name, argtypes, typeargtypes);
4291 }
4292 }
4293 //where
4294 private Map<Symbol, JCDiagnostic> mapCandidates() {
4295 MostSpecificMap candidates = new MostSpecificMap();
4296 for (Candidate c : resolveContext.candidates) {
4297 if (c.isApplicable()) continue;
4298 candidates.put(c);
4299 }
4300 return candidates;
4301 }
4302
4303 @SuppressWarnings("serial")
4304 private class MostSpecificMap extends LinkedHashMap<Symbol, JCDiagnostic> {
4305 private void put(Candidate c) {
4306 ListBuffer<Symbol> overridden = new ListBuffer<>();
4307 for (Symbol s : keySet()) {
4308 if (s == c.sym) {
4309 continue;
4310 }
4311 if (c.sym.overrides(s, (TypeSymbol)s.owner, types, false)) {
4312 overridden.add(s);
4313 } else if (s.overrides(c.sym, (TypeSymbol)c.sym.owner, types, false)) {
4314 return;
4315 }
4316 }
4317 for (Symbol s : overridden) {
4318 remove(s);
4319 }
4320 put(c.sym, c.details);
4321 }
4322 }
4323
4324 Map<Symbol, JCDiagnostic> filterCandidates(Map<Symbol, JCDiagnostic> candidatesMap) {
4325 Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<>();
4326 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
4327 JCDiagnostic d = _entry.getValue();
4328 if (!new Template(MethodCheckDiag.ARITY_MISMATCH.regex()).matches(d)) {
4329 candidates.put(_entry.getKey(), d);
4330 }
4331 }
4332 return candidates;
4333 }
4334
4335 private List<JCDiagnostic> candidateDetails(Map<Symbol, JCDiagnostic> candidatesMap, Type site) {
4336 List<JCDiagnostic> details = List.nil();
4337 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
4338 Symbol sym = _entry.getKey();
4339 JCDiagnostic detailDiag =
4340 diags.fragment(Fragments.InapplicableMethod(Kinds.kindName(sym),
4341 sym.location(site, types),
4342 sym.asMemberOf(site, types),
4343 _entry.getValue()));
4344 details = details.prepend(detailDiag);
4345 }
4346 //typically members are visited in reverse order (see Scope)
4347 //so we need to reverse the candidate list so that candidates
4348 //conform to source order
4349 return details;
4350 }
4351
4352 @Override
4353 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4354 Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates();
4355 Map<Symbol, JCDiagnostic> filteredCandidates = filterCandidates(candidatesMap);
4356 if (filteredCandidates.size() == 1) {
4357 return Pair.of(filteredCandidates.keySet().iterator().next(),
4358 filteredCandidates.values().iterator().next());
4359 }
4360 return null;
4361 }
4362 }
4363
4364 /**
4365 * DiamondError error class indicating that a constructor symbol is not applicable
4366 * given an actual arguments/type argument list using diamond inference.
4367 */
4368 class DiamondError extends InapplicableSymbolError {
4369
4370 Symbol sym;
4371
4372 public DiamondError(Symbol sym, MethodResolutionContext context) {
4373 super(sym.kind, "diamondError", context);
4374 this.sym = sym;
4375 }
4376
4377 JCDiagnostic getDetails() {
4378 return (sym.kind == WRONG_MTH) ?
4379 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd :
4380 null;
4381 }
4382
4383 @Override
4384 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
4385 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4386 JCDiagnostic details = getDetails();
4387 if (details != null && compactMethodDiags) {
4388 JCDiagnostic simpleDiag =
4389 MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, details);
4390 if (simpleDiag != null) {
4391 return simpleDiag;
4392 }
4393 }
4394 String key = details == null ?
4395 "cant.apply.diamond" :
4396 "cant.apply.diamond.1";
4397 return diags.create(dkind, log.currentSource(), pos, key,
4398 Fragments.Diamond(site.tsym), details);
4399 }
4400 }
4401
4402 /**
4403 * An InvalidSymbolError error class indicating that a symbol is not
4404 * accessible from a given site
4405 */
4406 class AccessError extends InvalidSymbolError {
4407
4408 private Env<AttrContext> env;
4409 private Type site;
4410
4411 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
4412 super(HIDDEN, sym, "access error");
4413 this.env = env;
4414 this.site = site;
4415 }
4416
4417 @Override
4418 public boolean exists() {
4419 return false;
4420 }
4421
4422 @Override
4423 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4424 DiagnosticPosition pos,
4425 Symbol location,
4426 Type site,
4427 Name name,
4428 List<Type> argtypes,
4429 List<Type> typeargtypes) {
4430 if (sym.name == names.init && sym.owner != site.tsym) {
4431 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
4432 pos, location, site, name, argtypes, typeargtypes);
4433 }
4434 else if ((sym.flags() & PUBLIC) != 0
4435 || (env != null && this.site != null
4436 && !isAccessible(env, this.site))) {
4437 if (sym.owner.kind == PCK) {
4438 return diags.create(dkind, log.currentSource(),
4439 pos, "not.def.access.package.cant.access",
4440 sym, sym.location(), inaccessiblePackageReason(env, sym.packge()));
4441 } else if ( sym.packge() != syms.rootPackage
4442 && !symbolPackageVisible(env, sym)) {
4443 return diags.create(dkind, log.currentSource(),
4444 pos, "not.def.access.class.intf.cant.access.reason",
4445 sym, sym.location(), sym.location().packge(),
4446 inaccessiblePackageReason(env, sym.packge()));
4447 } else {
4448 return diags.create(dkind, log.currentSource(),
4449 pos, "not.def.access.class.intf.cant.access",
4450 sym, sym.location());
4451 }
4452 }
4453 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
4454 return diags.create(dkind, log.currentSource(),
4455 pos, "report.access", sym,
4456 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
4457 sym.location());
4458 }
4459 else {
4460 return diags.create(dkind, log.currentSource(),
4461 pos, "not.def.public.cant.access", sym, sym.location());
4462 }
4463 }
4464
4465 private String toString(Type type) {
4466 StringBuilder sb = new StringBuilder();
4467 sb.append(type);
4468 if (type != null) {
4469 sb.append("[tsym:").append(type.tsym);
4470 if (type.tsym != null)
4471 sb.append("packge:").append(type.tsym.packge());
4472 sb.append("]");
4473 }
4474 return sb.toString();
4475 }
4476 }
4477
4478 class InvisibleSymbolError extends InvalidSymbolError {
4479
4480 private final Env<AttrContext> env;
4481 private final boolean suppressError;
4482
4483 InvisibleSymbolError(Env<AttrContext> env, boolean suppressError, Symbol sym) {
4484 super(HIDDEN, sym, "invisible class error");
4485 this.env = env;
4486 this.suppressError = suppressError;
4487 this.name = sym.name;
4488 }
4489
4490 @Override
4491 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4492 DiagnosticPosition pos,
4493 Symbol location,
4494 Type site,
4495 Name name,
4496 List<Type> argtypes,
4497 List<Type> typeargtypes) {
4498 if (suppressError)
4499 return null;
4500
4501 if (sym.kind == PCK) {
4502 JCDiagnostic details = inaccessiblePackageReason(env, sym.packge());
4503 return diags.create(dkind, log.currentSource(),
4504 pos, "package.not.visible", sym, details);
4505 }
4506
4507 JCDiagnostic details = inaccessiblePackageReason(env, sym.packge());
4508
4509 if (pos.getTree() != null) {
4510 Symbol o = sym;
4511 JCTree tree = pos.getTree();
4512
4513 while (o.kind != PCK && tree.hasTag(SELECT)) {
4514 o = o.owner;
4515 tree = ((JCFieldAccess) tree).selected;
4516 }
4517
4518 if (o.kind == PCK) {
4519 pos = tree.pos();
4520
4521 return diags.create(dkind, log.currentSource(),
4522 pos, "package.not.visible", o, details);
4523 }
4524 }
4525
4526 return diags.create(dkind, log.currentSource(),
4527 pos, "not.def.access.package.cant.access", sym, sym.packge(), details);
4528 }
4529 }
4530
4531 JCDiagnostic inaccessiblePackageReason(Env<AttrContext> env, PackageSymbol sym) {
4532 //no dependency:
4533 if (!env.toplevel.modle.readModules.contains(sym.modle)) {
4534 //does not read:
4535 if (sym.modle != syms.unnamedModule) {
4536 if (env.toplevel.modle != syms.unnamedModule) {
4537 return diags.fragment(Fragments.NotDefAccessDoesNotRead(env.toplevel.modle,
4538 sym,
4539 sym.modle));
4540 } else {
4541 return diags.fragment(Fragments.NotDefAccessDoesNotReadFromUnnamed(sym,
4542 sym.modle));
4543 }
4544 } else {
4545 return diags.fragment(Fragments.NotDefAccessDoesNotReadUnnamed(sym,
4546 env.toplevel.modle));
4547 }
4548 } else {
4549 if (sym.packge().modle.exports.stream().anyMatch(e -> e.packge == sym)) {
4550 //not exported to this module:
4551 if (env.toplevel.modle != syms.unnamedModule) {
4552 return diags.fragment(Fragments.NotDefAccessNotExportedToModule(sym,
4553 sym.modle,
4554 env.toplevel.modle));
4555 } else {
4556 return diags.fragment(Fragments.NotDefAccessNotExportedToModuleFromUnnamed(sym,
4557 sym.modle));
4558 }
4559 } else {
4560 //not exported:
4561 if (env.toplevel.modle != syms.unnamedModule) {
4562 return diags.fragment(Fragments.NotDefAccessNotExported(sym,
4563 sym.modle));
4564 } else {
4565 return diags.fragment(Fragments.NotDefAccessNotExportedFromUnnamed(sym,
4566 sym.modle));
4567 }
4568 }
4569 }
4570 }
4571
4572 /**
4573 * InvalidSymbolError error class indicating that an instance member
4574 * has erroneously been accessed from a static context.
4575 */
4576 class StaticError extends InvalidSymbolError {
4577
4578 StaticError(Symbol sym) {
4579 super(STATICERR, sym, "static error");
4580 }
4581
4582 @Override
4583 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4584 DiagnosticPosition pos,
4585 Symbol location,
4586 Type site,
4587 Name name,
4588 List<Type> argtypes,
4589 List<Type> typeargtypes) {
4590 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS))
4591 ? types.erasure(sym.type).tsym
4592 : sym);
4593 return diags.create(dkind, log.currentSource(), pos,
4594 "non-static.cant.be.ref", kindName(sym), errSym);
4595 }
4596 }
4597
4598 /**
4599 * InvalidSymbolError error class indicating that a pair of symbols
4600 * (either methods, constructors or operands) are ambiguous
4601 * given an actual arguments/type argument list.
4602 */
4603 class AmbiguityError extends ResolveError {
4604
4605 /** The other maximally specific symbol */
4606 List<Symbol> ambiguousSyms = List.nil();
4607
4608 @Override
4609 public boolean exists() {
4610 return true;
4611 }
4612
4613 AmbiguityError(Symbol sym1, Symbol sym2) {
4614 super(AMBIGUOUS, "ambiguity error");
4615 ambiguousSyms = flatten(sym2).appendList(flatten(sym1));
4616 }
4617
4618 private List<Symbol> flatten(Symbol sym) {
4619 if (sym.kind == AMBIGUOUS) {
4620 return ((AmbiguityError)sym.baseSymbol()).ambiguousSyms;
4621 } else {
4622 return List.of(sym);
4623 }
4624 }
4625
4626 AmbiguityError addAmbiguousSymbol(Symbol s) {
4627 ambiguousSyms = ambiguousSyms.prepend(s);
4628 return this;
4629 }
4630
4631 @Override
4632 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4633 DiagnosticPosition pos,
4634 Symbol location,
4635 Type site,
4636 Name name,
4637 List<Type> argtypes,
4638 List<Type> typeargtypes) {
4639 List<Symbol> diagSyms = ambiguousSyms.reverse();
4640 Symbol s1 = diagSyms.head;
4641 Symbol s2 = diagSyms.tail.head;
4642 Name sname = s1.name;
4643 if (sname == names.init) sname = s1.owner.name;
4644 return diags.create(dkind, log.currentSource(),
4645 pos, "ref.ambiguous", sname,
4646 kindName(s1),
4647 s1,
4648 s1.location(site, types),
4649 kindName(s2),
4650 s2,
4651 s2.location(site, types));
4652 }
4653
4654 /**
4655 * If multiple applicable methods are found during overload and none of them
4656 * is more specific than the others, attempt to merge their signatures.
4657 */
4658 Symbol mergeAbstracts(Type site) {
4659 List<Symbol> ambiguousInOrder = ambiguousSyms.reverse();
4660 return types.mergeAbstracts(ambiguousInOrder, site, true).orElse(this);
4661 }
4662
4663 @Override
4664 protected Symbol access(Name name, TypeSymbol location) {
4665 Symbol firstAmbiguity = ambiguousSyms.last();
4666 return firstAmbiguity.kind == TYP ?
4667 types.createErrorType(name, location, firstAmbiguity.type).tsym :
4668 firstAmbiguity;
4669 }
4670 }
4671
4672 class BadVarargsMethod extends ResolveError {
4673
4674 ResolveError delegatedError;
4675
4676 BadVarargsMethod(ResolveError delegatedError) {
4677 super(delegatedError.kind, "badVarargs");
4678 this.delegatedError = delegatedError;
4679 }
4680
4681 @Override
4682 public Symbol baseSymbol() {
4683 return delegatedError.baseSymbol();
4684 }
4685
4686 @Override
4687 protected Symbol access(Name name, TypeSymbol location) {
4688 return delegatedError.access(name, location);
4689 }
4690
4691 @Override
4692 public boolean exists() {
4693 return true;
4694 }
4695
4696 @Override
4697 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4698 return delegatedError.getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes);
4699 }
4700 }
4701
4702 /**
4703 * BadMethodReferenceError error class indicating that a method reference symbol has been found,
4704 * but with the wrong staticness.
4705 */
4706 class BadMethodReferenceError extends StaticError {
4707
4708 boolean unboundLookup;
4709
4710 public BadMethodReferenceError(Symbol sym, boolean unboundLookup) {
4711 super(sym);
4712 this.unboundLookup = unboundLookup;
4713 }
4714
4715 @Override
4716 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4717 final String key;
4718 if (!unboundLookup) {
4719 key = "bad.static.method.in.bound.lookup";
4720 } else if (sym.isStatic()) {
4721 key = "bad.static.method.in.unbound.lookup";
4722 } else {
4723 key = "bad.instance.method.in.unbound.lookup";
4724 }
4725 return sym.kind.isResolutionError() ?
4726 ((ResolveError)sym).getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes) :
4727 diags.create(dkind, log.currentSource(), pos, key, Kinds.kindName(sym), sym);
4728 }
4729 }
4730
4731 /**
4732 * BadConstructorReferenceError error class indicating that a constructor reference symbol has been found,
4733 * but pointing to a class for which an enclosing instance is not available.
4734 */
4735 class BadConstructorReferenceError extends InvalidSymbolError {
4736
4737 public BadConstructorReferenceError(Symbol sym) {
4738 super(MISSING_ENCL, sym, "BadConstructorReferenceError");
4739 }
4740
4741 @Override
4742 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4743 return diags.create(dkind, log.currentSource(), pos,
4744 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType());
4745 }
4746 }
4747
4748 class BadClassFileError extends InvalidSymbolError {
4749
4750 private final CompletionFailure ex;
4751
4752 public BadClassFileError(CompletionFailure ex) {
4753 super(HIDDEN, ex.sym, "BadClassFileError");
4754 this.name = sym.name;
4755 this.ex = ex;
4756 }
4757
4758 @Override
4759 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4760 JCDiagnostic d = diags.create(dkind, log.currentSource(), pos,
4761 "cant.access", ex.sym, ex.getDetailValue());
4762
4763 d.setFlag(DiagnosticFlag.NON_DEFERRABLE);
4764 return d;
4765 }
4766
4767 }
4768
4769 /**
4770 * Helper class for method resolution diagnostic simplification.
4771 * Certain resolution diagnostic are rewritten as simpler diagnostic
4772 * where the enclosing resolution diagnostic (i.e. 'inapplicable method')
4773 * is stripped away, as it doesn't carry additional info. The logic
4774 * for matching a given diagnostic is given in terms of a template
4775 * hierarchy: a diagnostic template can be specified programmatically,
4776 * so that only certain diagnostics are matched. Each templete is then
4777 * associated with a rewriter object that carries out the task of rewtiting
4778 * the diagnostic to a simpler one.
4779 */
4780 static class MethodResolutionDiagHelper {
4781
4782 /**
4783 * A diagnostic rewriter transforms a method resolution diagnostic
4784 * into a simpler one
4785 */
4786 interface DiagnosticRewriter {
4787 JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
4788 DiagnosticPosition preferredPos, DiagnosticSource preferredSource,
4789 DiagnosticType preferredKind, JCDiagnostic d);
4790 }
4791
4792 /**
4793 * A diagnostic template is made up of two ingredients: (i) a regular
4794 * expression for matching a diagnostic key and (ii) a list of sub-templates
4795 * for matching diagnostic arguments.
4796 */
4797 static class Template {
4798
4799 /** regex used to match diag key */
4800 String regex;
4801
4802 /** templates used to match diagnostic args */
4803 Template[] subTemplates;
4804
4805 Template(String key, Template... subTemplates) {
4806 this.regex = key;
4807 this.subTemplates = subTemplates;
4808 }
4809
4810 /**
4811 * Returns true if the regex matches the diagnostic key and if
4812 * all diagnostic arguments are matches by corresponding sub-templates.
4813 */
4814 boolean matches(Object o) {
4815 JCDiagnostic d = (JCDiagnostic)o;
4816 Object[] args = d.getArgs();
4817 if (!d.getCode().matches(regex) ||
4818 subTemplates.length != d.getArgs().length) {
4819 return false;
4820 }
4821 for (int i = 0; i < args.length ; i++) {
4822 if (!subTemplates[i].matches(args[i])) {
4823 return false;
4824 }
4825 }
4826 return true;
4827 }
4828 }
4829
4830 /**
4831 * Common rewriter for all argument mismatch simplifications.
4832 */
4833 static class ArgMismatchRewriter implements DiagnosticRewriter {
4834
4835 /** the index of the subdiagnostic to be used as primary. */
4836 int causeIndex;
4837
4838 public ArgMismatchRewriter(int causeIndex) {
4839 this.causeIndex = causeIndex;
4840 }
4841
4842 @Override
4843 public JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
4844 DiagnosticPosition preferredPos, DiagnosticSource preferredSource,
4845 DiagnosticType preferredKind, JCDiagnostic d) {
4846 JCDiagnostic cause = (JCDiagnostic)d.getArgs()[causeIndex];
4847 DiagnosticPosition pos = d.getDiagnosticPosition();
4848 if (pos == null) {
4849 pos = preferredPos;
4850 }
4851 return diags.create(preferredKind, preferredSource, pos,
4852 "prob.found.req", cause);
4853 }
4854 }
4855
4856 /** a dummy template that match any diagnostic argument */
4857 static final Template skip = new Template("") {
4858 @Override
4859 boolean matches(Object d) {
4860 return true;
4861 }
4862 };
4863
4864 /** template for matching inference-free arguments mismatch failures */
4865 static final Template argMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip);
4866
4867 /** template for matching inference related arguments mismatch failures */
4868 static final Template inferArgMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip, skip) {
4869 @Override
4870 boolean matches(Object o) {
4871 if (!super.matches(o)) {
4872 return false;
4873 }
4874 JCDiagnostic d = (JCDiagnostic)o;
4875 @SuppressWarnings("unchecked")
4876 List<Type> tvars = (List<Type>)d.getArgs()[0];
4877 return !containsAny(d, tvars);
4878 }
4879
4880 BiPredicate<Object, List<Type>> containsPredicate = (o, ts) -> {
4881 if (o instanceof Type type) {
4882 return type.containsAny(ts);
4883 } else if (o instanceof JCDiagnostic diagnostic) {
4884 return containsAny(diagnostic, ts);
4885 } else {
4886 return false;
4887 }
4888 };
4889
4890 boolean containsAny(JCDiagnostic d, List<Type> ts) {
4891 return Stream.of(d.getArgs())
4892 .anyMatch(o -> containsPredicate.test(o, ts));
4893 }
4894 };
4895
4896 /** rewriter map used for method resolution simplification */
4897 static final Map<Template, DiagnosticRewriter> rewriters = new LinkedHashMap<>();
4898
4899 static {
4900 rewriters.put(argMismatchTemplate, new ArgMismatchRewriter(0));
4901 rewriters.put(inferArgMismatchTemplate, new ArgMismatchRewriter(1));
4902 }
4903
4904 /**
4905 * Main entry point for diagnostic rewriting - given a diagnostic, see if any templates matches it,
4906 * and rewrite it accordingly.
4907 */
4908 static JCDiagnostic rewrite(JCDiagnostic.Factory diags, DiagnosticPosition pos, DiagnosticSource source,
4909 DiagnosticType dkind, JCDiagnostic d) {
4910 for (Map.Entry<Template, DiagnosticRewriter> _entry : rewriters.entrySet()) {
4911 if (_entry.getKey().matches(d)) {
4912 JCDiagnostic simpleDiag =
4913 _entry.getValue().rewriteDiagnostic(diags, pos, source, dkind, d);
4914 simpleDiag.setFlag(DiagnosticFlag.COMPRESSED);
4915 return simpleDiag;
4916 }
4917 }
4918 return null;
4919 }
4920 }
4921
4922 enum MethodResolutionPhase {
4923 BASIC(false, false),
4924 BOX(true, false),
4925 VARARITY(true, true) {
4926 @Override
4927 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) {
4928 //Check invariants (see {@code LookupHelper.shouldStop})
4929 Assert.check(bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS);
4930 if (!sym.kind.isResolutionError()) {
4931 //varargs resolution successful
4932 return sym;
4933 } else {
4934 //pick best error
4935 switch (bestSoFar.kind) {
4936 case WRONG_MTH:
4937 case WRONG_MTHS:
4938 //Override previous errors if they were caused by argument mismatch.
4939 //This generally means preferring current symbols - but we need to pay
4940 //attention to the fact that the varargs lookup returns 'less' candidates
4941 //than the previous rounds, and adjust that accordingly.
4942 switch (sym.kind) {
4943 case WRONG_MTH:
4944 //if the previous round matched more than one method, return that
4945 //result instead
4946 return bestSoFar.kind == WRONG_MTHS ?
4947 bestSoFar : sym;
4948 case ABSENT_MTH:
4949 //do not override erroneous symbol if the arity lookup did not
4950 //match any method
4951 return bestSoFar;
4952 case WRONG_MTHS:
4953 default:
4954 //safe to override
4955 return sym;
4956 }
4957 default:
4958 //otherwise, return first error
4959 return bestSoFar;
4960 }
4961 }
4962 }
4963 };
4964
4965 final boolean isBoxingRequired;
4966 final boolean isVarargsRequired;
4967
4968 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
4969 this.isBoxingRequired = isBoxingRequired;
4970 this.isVarargsRequired = isVarargsRequired;
4971 }
4972
4973 public boolean isBoxingRequired() {
4974 return isBoxingRequired;
4975 }
4976
4977 public boolean isVarargsRequired() {
4978 return isVarargsRequired;
4979 }
4980
4981 public Symbol mergeResults(Symbol prev, Symbol sym) {
4982 return sym;
4983 }
4984 }
4985
4986 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
4987
4988 /**
4989 * A resolution context is used to keep track of intermediate results of
4990 * overload resolution, such as list of method that are not applicable
4991 * (used to generate more precise diagnostics) and so on. Resolution contexts
4992 * can be nested - this means that when each overload resolution routine should
4993 * work within the resolution context it created.
4994 */
4995 class MethodResolutionContext {
4996
4997 private List<Candidate> candidates = List.nil();
4998
4999 MethodResolutionPhase step = null;
5000
5001 MethodCheck methodCheck = resolveMethodCheck;
5002
5003 private boolean internalResolution = false;
5004 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE;
5005
5006 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) {
5007 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null);
5008 candidates = candidates.append(c);
5009 }
5010
5011 void addApplicableCandidate(Symbol sym, Type mtype) {
5012 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype);
5013 candidates = candidates.append(c);
5014 }
5015
5016 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext, ResultInfo pendingResult, Warner warn) {
5017 DeferredAttrContext parent = (pendingResult == null)
5018 ? deferredAttr.emptyDeferredAttrContext
5019 : pendingResult.checkContext.deferredAttrContext();
5020 return deferredAttr.new DeferredAttrContext(attrMode, sym, step,
5021 inferenceContext, parent, warn);
5022 }
5023
5024 /**
5025 * This class represents an overload resolution candidate. There are two
5026 * kinds of candidates: applicable methods and inapplicable methods;
5027 * applicable methods have a pointer to the instantiated method type,
5028 * while inapplicable candidates contain further details about the
5029 * reason why the method has been considered inapplicable.
5030 */
5031 @SuppressWarnings("overrides")
5032 class Candidate {
5033
5034 final MethodResolutionPhase step;
5035 final Symbol sym;
5036 final JCDiagnostic details;
5037 final Type mtype;
5038
5039 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) {
5040 this.step = step;
5041 this.sym = sym;
5042 this.details = details;
5043 this.mtype = mtype;
5044 }
5045
5046 boolean isApplicable() {
5047 return mtype != null;
5048 }
5049 }
5050
5051 DeferredAttr.AttrMode attrMode() {
5052 return attrMode;
5053 }
5054
5055 boolean internal() {
5056 return internalResolution;
5057 }
5058 }
5059
5060 MethodResolutionContext currentResolutionContext = null;
5061 }