1 /*
2 * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.comp;
27
28 import com.sun.tools.javac.api.Formattable.LocalizedString;
29 import com.sun.tools.javac.code.*;
30 import com.sun.tools.javac.code.Scope.WriteableScope;
31 import com.sun.tools.javac.code.Source.Feature;
32 import com.sun.tools.javac.code.Symbol.*;
33 import com.sun.tools.javac.code.Type.*;
34 import com.sun.tools.javac.comp.Attr.ResultInfo;
35 import com.sun.tools.javac.comp.Check.CheckContext;
36 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
37 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
38 import com.sun.tools.javac.comp.DeferredAttr.DeferredType;
39 import com.sun.tools.javac.comp.Resolve.MethodResolutionContext.Candidate;
40 import com.sun.tools.javac.comp.Resolve.MethodResolutionDiagHelper.Template;
41 import com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind;
42 import com.sun.tools.javac.jvm.*;
43 import com.sun.tools.javac.main.Option;
44 import com.sun.tools.javac.resources.CompilerProperties.Errors;
45 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
46 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
47 import com.sun.tools.javac.tree.*;
48 import com.sun.tools.javac.tree.JCTree.*;
49 import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind;
50 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
51 import com.sun.tools.javac.util.*;
52 import com.sun.tools.javac.util.DefinedBy.Api;
53 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
54 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
55 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
56 import com.sun.tools.javac.util.JCDiagnostic.Warning;
57
58 import java.util.Arrays;
59 import java.util.Collection;
60 import java.util.EnumSet;
61 import java.util.HashSet;
62 import java.util.Iterator;
63 import java.util.LinkedHashMap;
64 import java.util.Map;
65 import java.util.Set;
66 import java.util.function.BiFunction;
67 import java.util.function.BiPredicate;
68 import java.util.function.Consumer;
69 import java.util.function.Function;
70 import java.util.function.Predicate;
71 import java.util.stream.Stream;
72
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 DeferredAttr deferredAttr;
100 Check chk;
101 Infer infer;
102 ClassFinder finder;
103 ModuleFinder moduleFinder;
104 Types types;
105 JCDiagnostic.Factory diags;
106 public final boolean allowFunctionalInterfaceMostSpecific;
107 public final boolean allowModules;
108 public final boolean checkVarargsAccessAfterResolution;
109 private final boolean compactMethodDiags;
110 private final boolean allowLocalVariableTypeInference;
111 private final boolean allowYieldStatement;
112 final EnumSet<VerboseResolutionMode> verboseResolutionMode;
113
114 WriteableScope polymorphicSignatureScope;
115
116 protected Resolve(Context context) {
117 context.put(resolveKey, this);
118 syms = Symtab.instance(context);
119
120 varNotFound = new SymbolNotFoundError(ABSENT_VAR);
121 methodNotFound = new SymbolNotFoundError(ABSENT_MTH);
122 typeNotFound = new SymbolNotFoundError(ABSENT_TYP);
123 referenceNotFound = ReferenceLookupResult.error(methodNotFound);
124
125 names = Names.instance(context);
126 log = Log.instance(context);
127 attr = Attr.instance(context);
128 deferredAttr = DeferredAttr.instance(context);
129 chk = Check.instance(context);
130 infer = Infer.instance(context);
131 finder = ClassFinder.instance(context);
132 moduleFinder = ModuleFinder.instance(context);
133 types = Types.instance(context);
134 diags = JCDiagnostic.Factory.instance(context);
135 Preview preview = Preview.instance(context);
136 Source source = Source.instance(context);
137 Options options = Options.instance(context);
138 compactMethodDiags = options.isSet(Option.XDIAGS, "compact") ||
139 options.isUnset(Option.XDIAGS) && options.isUnset("rawDiagnostics");
140 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
141 Target target = Target.instance(context);
142 allowFunctionalInterfaceMostSpecific = Feature.FUNCTIONAL_INTERFACE_MOST_SPECIFIC.allowedInSource(source);
143 allowLocalVariableTypeInference = Feature.LOCAL_VARIABLE_TYPE_INFERENCE.allowedInSource(source);
144 allowYieldStatement = (!preview.isPreview(Feature.SWITCH_EXPRESSION) || preview.isEnabled()) &&
145 Feature.SWITCH_EXPRESSION.allowedInSource(source);
146 checkVarargsAccessAfterResolution =
147 Feature.POST_APPLICABILITY_VARARGS_ACCESS_CHECK.allowedInSource(source);
148 polymorphicSignatureScope = WriteableScope.create(syms.noSymbol);
149 allowModules = Feature.MODULES.allowedInSource(source);
150 }
151
152 /** error symbols, which are returned when resolution fails
153 */
154 private final SymbolNotFoundError varNotFound;
155 private final SymbolNotFoundError methodNotFound;
156 private final SymbolNotFoundError typeNotFound;
157
158 /** empty reference lookup result */
159 private final ReferenceLookupResult referenceNotFound;
160
161 public static Resolve instance(Context context) {
162 Resolve instance = context.get(resolveKey);
163 if (instance == null)
164 instance = new Resolve(context);
165 return instance;
166 }
167
168 private static Symbol bestOf(Symbol s1,
169 Symbol s2) {
170 return s1.kind.betterThan(s2.kind) ? s1 : s2;
171 }
172
173 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support">
174 enum VerboseResolutionMode {
175 SUCCESS("success"),
176 FAILURE("failure"),
177 APPLICABLE("applicable"),
178 INAPPLICABLE("inapplicable"),
179 DEFERRED_INST("deferred-inference"),
180 PREDEF("predef"),
181 OBJECT_INIT("object-init"),
182 INTERNAL("internal");
183
184 final String opt;
185
186 private VerboseResolutionMode(String opt) {
187 this.opt = opt;
188 }
189
190 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) {
191 String s = opts.get("debug.verboseResolution");
192 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class);
193 if (s == null) return res;
194 if (s.contains("all")) {
195 res = EnumSet.allOf(VerboseResolutionMode.class);
196 }
197 Collection<String> args = Arrays.asList(s.split(","));
198 for (VerboseResolutionMode mode : values()) {
199 if (args.contains(mode.opt)) {
200 res.add(mode);
201 } else if (args.contains("-" + mode.opt)) {
202 res.remove(mode);
203 }
204 }
205 return res;
206 }
207 }
208
209 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site,
210 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) {
211 boolean success = !bestSoFar.kind.isResolutionError();
212
213 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) {
214 return;
215 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) {
216 return;
217 }
218
219 if (bestSoFar.name == names.init &&
220 bestSoFar.owner == syms.objectType.tsym &&
221 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) {
222 return; //skip diags for Object constructor resolution
223 } else if (site == syms.predefClass.type &&
224 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) {
225 return; //skip spurious diags for predef symbols (i.e. operators)
226 } else if (currentResolutionContext.internalResolution &&
227 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) {
228 return;
229 }
230
231 int pos = 0;
232 int mostSpecificPos = -1;
233 ListBuffer<JCDiagnostic> subDiags = new ListBuffer<>();
234 for (Candidate c : currentResolutionContext.candidates) {
235 if (currentResolutionContext.step != c.step ||
236 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) ||
237 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) {
238 continue;
239 } else {
240 subDiags.append(c.isApplicable() ?
241 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) :
242 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details));
243 if (c.sym == bestSoFar)
244 mostSpecificPos = pos;
245 pos++;
246 }
247 }
248 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1";
249 List<Type> argtypes2 = argtypes.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step));
250 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name,
251 site.tsym, mostSpecificPos, currentResolutionContext.step,
252 methodArguments(argtypes2),
253 methodArguments(typeargtypes));
254 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
255 log.report(d);
256 }
257
258 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) {
259 JCDiagnostic subDiag = null;
260 if (sym.type.hasTag(FORALL)) {
261 subDiag = diags.fragment(Fragments.PartialInstSig(inst));
262 }
263
264 String key = subDiag == null ?
265 "applicable.method.found" :
266 "applicable.method.found.1";
267
268 return diags.fragment(key, pos, sym, subDiag);
269 }
270
271 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) {
272 return diags.fragment(Fragments.NotApplicableMethodFound(pos, sym, subDiag));
273 }
274 // </editor-fold>
275
276 /* ************************************************************************
277 * Identifier resolution
278 *************************************************************************/
279
280 /** An environment is "static" if its static level is greater than
281 * the one of its outer environment
282 */
283 protected static boolean isStatic(Env<AttrContext> env) {
284 return env.outer != null && env.info.staticLevel > env.outer.info.staticLevel;
285 }
286
287 /** An environment is an "initializer" if it is a constructor or
288 * an instance initializer.
289 */
290 static boolean isInitializer(Env<AttrContext> env) {
291 Symbol owner = env.info.scope.owner;
292 return owner.isConstructor() ||
293 owner.owner.kind == TYP &&
294 (owner.kind == VAR ||
295 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
296 (owner.flags() & STATIC) == 0;
297 }
298
299 /** Is class accessible in given environment?
300 * @param env The current environment.
301 * @param c The class whose accessibility is checked.
302 */
303 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
304 return isAccessible(env, c, false);
305 }
306
307 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) {
308
309 /* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor
310 to refer to an inaccessible type
311 */
312 if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0)
313 return true;
314
315 if (env.info.visitingServiceImplementation &&
316 env.toplevel.modle == c.packge().modle) {
317 return true;
318 }
319
320 boolean isAccessible = false;
321 switch ((short)(c.flags() & AccessFlags)) {
322 case PRIVATE:
323 isAccessible =
324 env.enclClass.sym.outermostClass() ==
325 c.owner.outermostClass();
326 break;
327 case 0:
328 isAccessible =
329 env.toplevel.packge == c.owner // fast special case
330 ||
331 env.toplevel.packge == c.packge();
332 break;
333 default: // error recovery
334 isAccessible = true;
335 break;
336 case PUBLIC:
337 if (allowModules) {
338 ModuleSymbol currModule = env.toplevel.modle;
339 currModule.complete();
340 PackageSymbol p = c.packge();
341 isAccessible =
342 currModule == p.modle ||
343 currModule.visiblePackages.get(p.fullname) == p ||
344 p == syms.rootPackage ||
345 (p.modle == syms.unnamedModule && currModule.readModules.contains(p.modle));
346 } else {
347 isAccessible = true;
348 }
349 break;
350 case PROTECTED:
351 isAccessible =
352 env.toplevel.packge == c.owner // fast special case
353 ||
354 env.toplevel.packge == c.packge()
355 ||
356 isInnerSubClass(env.enclClass.sym, c.owner);
357 break;
358 }
359 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
360 isAccessible :
361 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
362 }
363 //where
364 /** Is given class a subclass of given base class, or an inner class
365 * of a subclass?
366 * Return null if no such class exists.
367 * @param c The class which is the subclass or is contained in it.
368 * @param base The base class
369 */
370 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
371 while (c != null && !c.isSubClass(base, types)) {
372 c = c.owner.enclClass();
373 }
374 return c != null;
375 }
376
377 boolean isAccessible(Env<AttrContext> env, Type t) {
378 return isAccessible(env, t, false);
379 }
380
381 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) {
382 return (t.hasTag(ARRAY))
383 ? isAccessible(env, types.cvarUpperBound(types.elemtype(t)))
384 : isAccessible(env, t.tsym, checkInner);
385 }
386
387 /** Is symbol accessible as a member of given type in given environment?
388 * @param env The current environment.
389 * @param site The type of which the tested symbol is regarded
390 * as a member.
391 * @param sym The symbol.
392 */
393 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
394 return isAccessible(env, site, sym, false);
395 }
396 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) {
397 if (sym.name == names.init && sym.owner != site.tsym) return false;
398
399 /* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor
400 to refer to an inaccessible type
401 */
402 if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0)
403 return true;
404
405 if (env.info.visitingServiceImplementation &&
406 env.toplevel.modle == sym.packge().modle) {
407 return true;
408 }
409
410 switch ((short)(sym.flags() & AccessFlags)) {
411 case PRIVATE:
412 return
413 (env.enclClass.sym == sym.owner // fast special case
414 ||
415 env.enclClass.sym.outermostClass() ==
416 sym.owner.outermostClass())
417 &&
418 sym.isInheritedIn(site.tsym, types);
419 case 0:
420 return
421 (env.toplevel.packge == sym.owner.owner // fast special case
422 ||
423 env.toplevel.packge == sym.packge())
424 &&
425 isAccessible(env, site, checkInner)
426 &&
427 sym.isInheritedIn(site.tsym, types)
428 &&
429 notOverriddenIn(site, sym);
430 case PROTECTED:
431 return
432 (env.toplevel.packge == sym.owner.owner // fast special case
433 ||
434 env.toplevel.packge == sym.packge()
435 ||
436 isProtectedAccessible(sym, env.enclClass.sym, site)
437 ||
438 // OK to select instance method or field from 'super' or type name
439 // (but type names should be disallowed elsewhere!)
440 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
441 &&
442 isAccessible(env, site, checkInner)
443 &&
444 notOverriddenIn(site, sym);
445 default: // this case includes erroneous combinations as well
446 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
447 }
448 }
449 //where
450 /* `sym' is accessible only if not overridden by
451 * another symbol which is a member of `site'
452 * (because, if it is overridden, `sym' is not strictly
453 * speaking a member of `site'). A polymorphic signature method
454 * cannot be overridden (e.g. MH.invokeExact(Object[])).
455 */
456 private boolean notOverriddenIn(Type site, Symbol sym) {
457 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
458 return true;
459 else {
460 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
461 return (s2 == null || s2 == sym || sym.owner == s2.owner ||
462 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
463 }
464 }
465 //where
466 /** Is given protected symbol accessible if it is selected from given site
467 * and the selection takes place in given class?
468 * @param sym The symbol with protected access
469 * @param c The class where the access takes place
470 * @site The type of the qualifier
471 */
472 private
473 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
474 Type newSite = site.hasTag(TYPEVAR) ? site.getUpperBound() : site;
475 while (c != null &&
476 !(c.isSubClass(sym.owner, types) &&
477 (c.flags() & INTERFACE) == 0 &&
478 // In JLS 2e 6.6.2.1, the subclass restriction applies
479 // only to instance fields and methods -- types are excluded
480 // regardless of whether they are declared 'static' or not.
481 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || newSite.tsym.isSubClass(c, types))))
482 c = c.owner.enclClass();
483 return c != null;
484 }
485
486 /**
487 * Performs a recursive scan of a type looking for accessibility problems
488 * from current attribution environment
489 */
490 void checkAccessibleType(Env<AttrContext> env, Type t) {
491 accessibilityChecker.visit(t, env);
492 }
493
494 /**
495 * Accessibility type-visitor
496 */
497 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker =
498 new Types.SimpleVisitor<Void, Env<AttrContext>>() {
499
500 void visit(List<Type> ts, Env<AttrContext> env) {
501 for (Type t : ts) {
502 visit(t, env);
503 }
504 }
505
506 public Void visitType(Type t, Env<AttrContext> env) {
507 return null;
508 }
509
510 @Override
511 public Void visitArrayType(ArrayType t, Env<AttrContext> env) {
512 visit(t.elemtype, env);
513 return null;
514 }
515
516 @Override
517 public Void visitClassType(ClassType t, Env<AttrContext> env) {
518 visit(t.getTypeArguments(), env);
519 if (!isAccessible(env, t, true)) {
520 accessBase(new AccessError(env, null, t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true);
521 }
522 return null;
523 }
524
525 @Override
526 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) {
527 visit(t.type, env);
528 return null;
529 }
530
531 @Override
532 public Void visitMethodType(MethodType t, Env<AttrContext> env) {
533 visit(t.getParameterTypes(), env);
534 visit(t.getReturnType(), env);
535 visit(t.getThrownTypes(), env);
536 return null;
537 }
538 };
539
540 /** Try to instantiate the type of a method so that it fits
541 * given type arguments and argument types. If successful, return
542 * the method's instantiated type, else return null.
543 * The instantiation will take into account an additional leading
544 * formal parameter if the method is an instance method seen as a member
545 * of an under determined site. In this case, we treat site as an additional
546 * parameter and the parameters of the class containing the method as
547 * additional type variables that get instantiated.
548 *
549 * @param env The current environment
550 * @param site The type of which the method is a member.
551 * @param m The method symbol.
552 * @param argtypes The invocation's given value arguments.
553 * @param typeargtypes The invocation's given type arguments.
554 * @param allowBoxing Allow boxing conversions of arguments.
555 * @param useVarargs Box trailing arguments into an array for varargs.
556 */
557 Type rawInstantiate(Env<AttrContext> env,
558 Type site,
559 Symbol m,
560 ResultInfo resultInfo,
561 List<Type> argtypes,
562 List<Type> typeargtypes,
563 boolean allowBoxing,
564 boolean useVarargs,
565 Warner warn) throws Infer.InferenceException {
566 Type mt = types.memberType(site, m);
567 // tvars is the list of formal type variables for which type arguments
568 // need to inferred.
569 List<Type> tvars = List.nil();
570 if (typeargtypes == null) typeargtypes = List.nil();
571 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
572 // This is not a polymorphic method, but typeargs are supplied
573 // which is fine, see JLS 15.12.2.1
574 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
575 ForAll pmt = (ForAll) mt;
576 if (typeargtypes.length() != pmt.tvars.length())
577 // not enough args
578 throw new InapplicableMethodException(diags.fragment(Fragments.WrongNumberTypeArgs(Integer.toString(pmt.tvars.length()))));
579 // Check type arguments are within bounds
580 List<Type> formals = pmt.tvars;
581 List<Type> actuals = typeargtypes;
582 while (formals.nonEmpty() && actuals.nonEmpty()) {
583 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
584 pmt.tvars, typeargtypes);
585 for (; bounds.nonEmpty(); bounds = bounds.tail) {
586 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn)) {
587 throw new InapplicableMethodException(diags.fragment(Fragments.ExplicitParamDoNotConformToBounds(actuals.head, bounds)));
588 }
589 }
590 formals = formals.tail;
591 actuals = actuals.tail;
592 }
593 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
594 } else if (mt.hasTag(FORALL)) {
595 ForAll pmt = (ForAll) mt;
596 List<Type> tvars1 = types.newInstances(pmt.tvars);
597 tvars = tvars.appendList(tvars1);
598 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
599 }
600
601 // find out whether we need to go the slow route via infer
602 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/
603 for (List<Type> l = argtypes;
604 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
605 l = l.tail) {
606 if (l.head.hasTag(FORALL)) instNeeded = true;
607 }
608
609 if (instNeeded) {
610 return infer.instantiateMethod(env,
611 tvars,
612 (MethodType)mt,
613 resultInfo,
614 (MethodSymbol)m,
615 argtypes,
616 allowBoxing,
617 useVarargs,
618 currentResolutionContext,
619 warn);
620 }
621
622 DeferredAttr.DeferredAttrContext dc = currentResolutionContext.deferredAttrContext(m, infer.emptyContext, resultInfo, warn);
623 currentResolutionContext.methodCheck.argumentsAcceptable(env, dc,
624 argtypes, mt.getParameterTypes(), warn);
625 dc.complete();
626 return mt;
627 }
628
629 Type checkMethod(Env<AttrContext> env,
630 Type site,
631 Symbol m,
632 ResultInfo resultInfo,
633 List<Type> argtypes,
634 List<Type> typeargtypes,
635 Warner warn) {
636 MethodResolutionContext prevContext = currentResolutionContext;
637 try {
638 currentResolutionContext = new MethodResolutionContext();
639 currentResolutionContext.attrMode = (resultInfo.pt == Infer.anyPoly) ?
640 AttrMode.SPECULATIVE : DeferredAttr.AttrMode.CHECK;
641 if (env.tree.hasTag(JCTree.Tag.REFERENCE)) {
642 //method/constructor references need special check class
643 //to handle inference variables in 'argtypes' (might happen
644 //during an unsticking round)
645 currentResolutionContext.methodCheck =
646 new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
647 }
648 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase;
649 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
650 step.isBoxingRequired(), step.isVarargsRequired(), warn);
651 }
652 finally {
653 currentResolutionContext = prevContext;
654 }
655 }
656
657 /** Same but returns null instead throwing a NoInstanceException
658 */
659 Type instantiate(Env<AttrContext> env,
660 Type site,
661 Symbol m,
662 ResultInfo resultInfo,
663 List<Type> argtypes,
664 List<Type> typeargtypes,
665 boolean allowBoxing,
666 boolean useVarargs,
667 Warner warn) {
668 try {
669 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
670 allowBoxing, useVarargs, warn);
671 } catch (InapplicableMethodException ex) {
672 return null;
673 }
674 }
675
676 /**
677 * This interface defines an entry point that should be used to perform a
678 * method check. A method check usually consist in determining as to whether
679 * a set of types (actuals) is compatible with another set of types (formals).
680 * Since the notion of compatibility can vary depending on the circumstances,
681 * this interfaces allows to easily add new pluggable method check routines.
682 */
683 interface MethodCheck {
684 /**
685 * Main method check routine. A method check usually consist in determining
686 * as to whether a set of types (actuals) is compatible with another set of
687 * types (formals). If an incompatibility is found, an unchecked exception
688 * is assumed to be thrown.
689 */
690 void argumentsAcceptable(Env<AttrContext> env,
691 DeferredAttrContext deferredAttrContext,
692 List<Type> argtypes,
693 List<Type> formals,
694 Warner warn);
695
696 /**
697 * Retrieve the method check object that will be used during a
698 * most specific check.
699 */
700 MethodCheck mostSpecificCheck(List<Type> actuals);
701 }
702
703 /**
704 * Helper enum defining all method check diagnostics (used by resolveMethodCheck).
705 */
706 enum MethodCheckDiag {
707 /**
708 * Actuals and formals differs in length.
709 */
710 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"),
711 /**
712 * An actual is incompatible with a formal.
713 */
714 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"),
715 /**
716 * An actual is incompatible with the varargs element type.
717 */
718 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"),
719 /**
720 * The varargs element type is inaccessible.
721 */
722 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type");
723
724 final String basicKey;
725 final String inferKey;
726
727 MethodCheckDiag(String basicKey, String inferKey) {
728 this.basicKey = basicKey;
729 this.inferKey = inferKey;
730 }
731
732 String regex() {
733 return String.format("([a-z]*\\.)*(%s|%s)", basicKey, inferKey);
734 }
735 }
736
737 /**
738 * Dummy method check object. All methods are deemed applicable, regardless
739 * of their formal parameter types.
740 */
741 MethodCheck nilMethodCheck = new MethodCheck() {
742 public void argumentsAcceptable(Env<AttrContext> env, DeferredAttrContext deferredAttrContext, List<Type> argtypes, List<Type> formals, Warner warn) {
743 //do nothing - method always applicable regardless of actuals
744 }
745
746 public MethodCheck mostSpecificCheck(List<Type> actuals) {
747 return this;
748 }
749 };
750
751 /**
752 * Base class for 'real' method checks. The class defines the logic for
753 * iterating through formals and actuals and provides and entry point
754 * that can be used by subclasses in order to define the actual check logic.
755 */
756 abstract class AbstractMethodCheck implements MethodCheck {
757 @Override
758 public void argumentsAcceptable(final Env<AttrContext> env,
759 DeferredAttrContext deferredAttrContext,
760 List<Type> argtypes,
761 List<Type> formals,
762 Warner warn) {
763 //should we expand formals?
764 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired();
765 JCTree callTree = treeForDiagnostics(env);
766 List<JCExpression> trees = TreeInfo.args(callTree);
767
768 //inference context used during this method check
769 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
770
771 Type varargsFormal = useVarargs ? formals.last() : null;
772
773 if (varargsFormal == null &&
774 argtypes.size() != formals.size()) {
775 reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
776 }
777
778 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
779 DiagnosticPosition pos = trees != null ? trees.head : null;
780 checkArg(pos, false, argtypes.head, formals.head, deferredAttrContext, warn);
781 argtypes = argtypes.tail;
782 formals = formals.tail;
783 trees = trees != null ? trees.tail : trees;
784 }
785
786 if (formals.head != varargsFormal) {
787 reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
788 }
789
790 if (useVarargs) {
791 //note: if applicability check is triggered by most specific test,
792 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
793 final Type elt = types.elemtype(varargsFormal);
794 while (argtypes.nonEmpty()) {
795 DiagnosticPosition pos = trees != null ? trees.head : null;
796 checkArg(pos, true, argtypes.head, elt, deferredAttrContext, warn);
797 argtypes = argtypes.tail;
798 trees = trees != null ? trees.tail : trees;
799 }
800 }
801 }
802
803 // where
804 private JCTree treeForDiagnostics(Env<AttrContext> env) {
805 return env.info.preferredTreeForDiagnostics != null ? env.info.preferredTreeForDiagnostics : env.tree;
806 }
807
808 /**
809 * Does the actual argument conforms to the corresponding formal?
810 */
811 abstract void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn);
812
813 protected void reportMC(DiagnosticPosition pos, MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
814 boolean inferDiag = inferenceContext != infer.emptyContext;
815 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) {
816 Object[] args2 = new Object[args.length + 1];
817 System.arraycopy(args, 0, args2, 1, args.length);
818 args2[0] = inferenceContext.inferenceVars();
819 args = args2;
820 }
821 String key = inferDiag ? diag.inferKey : diag.basicKey;
822 throw inferDiag ?
823 infer.error(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args)) :
824 methodCheckFailure.setMessage(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args));
825 }
826
827 /**
828 * To eliminate the overhead associated with allocating an exception object in such an
829 * hot execution path, we use flyweight pattern - and share the same exception instance
830 * across multiple method check failures.
831 */
832 class SharedInapplicableMethodException extends InapplicableMethodException {
833 private static final long serialVersionUID = 0;
834
835 SharedInapplicableMethodException() {
836 super(null);
837 }
838
839 SharedInapplicableMethodException setMessage(JCDiagnostic details) {
840 this.diagnostic = details;
841 return this;
842 }
843 }
844
845 SharedInapplicableMethodException methodCheckFailure = new SharedInapplicableMethodException();
846
847 public MethodCheck mostSpecificCheck(List<Type> actuals) {
848 return nilMethodCheck;
849 }
850
851 }
852
853 /**
854 * Arity-based method check. A method is applicable if the number of actuals
855 * supplied conforms to the method signature.
856 */
857 MethodCheck arityMethodCheck = new AbstractMethodCheck() {
858 @Override
859 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
860 //do nothing - actual always compatible to formals
861 }
862
863 @Override
864 public String toString() {
865 return "arityMethodCheck";
866 }
867 };
868
869 /**
870 * Main method applicability routine. Given a list of actual types A,
871 * a list of formal types F, determines whether the types in A are
872 * compatible (by method invocation conversion) with the types in F.
873 *
874 * Since this routine is shared between overload resolution and method
875 * type-inference, a (possibly empty) inference context is used to convert
876 * formal types to the corresponding 'undet' form ahead of a compatibility
877 * check so that constraints can be propagated and collected.
878 *
879 * Moreover, if one or more types in A is a deferred type, this routine uses
880 * DeferredAttr in order to perform deferred attribution. If one or more actual
881 * deferred types are stuck, they are placed in a queue and revisited later
882 * after the remainder of the arguments have been seen. If this is not sufficient
883 * to 'unstuck' the argument, a cyclic inference error is called out.
884 *
885 * A method check handler (see above) is used in order to report errors.
886 */
887 MethodCheck resolveMethodCheck = new AbstractMethodCheck() {
888
889 @Override
890 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
891 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
892 mresult.check(pos, actual);
893 }
894
895 @Override
896 public void argumentsAcceptable(final Env<AttrContext> env,
897 DeferredAttrContext deferredAttrContext,
898 List<Type> argtypes,
899 List<Type> formals,
900 Warner warn) {
901 super.argumentsAcceptable(env, deferredAttrContext, argtypes, formals, warn);
902 // should we check varargs element type accessibility?
903 if (deferredAttrContext.phase.isVarargsRequired()) {
904 if (deferredAttrContext.mode == AttrMode.CHECK || !checkVarargsAccessAfterResolution) {
905 varargsAccessible(env, types.elemtype(formals.last()), deferredAttrContext.inferenceContext);
906 }
907 }
908 }
909
910 /**
911 * Test that the runtime array element type corresponding to 't' is accessible. 't' should be the
912 * varargs element type of either the method invocation type signature (after inference completes)
913 * or the method declaration signature (before inference completes).
914 */
915 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) {
916 if (inferenceContext.free(t)) {
917 inferenceContext.addFreeTypeListener(List.of(t),
918 solvedContext -> varargsAccessible(env, solvedContext.asInstType(t), solvedContext));
919 } else {
920 if (!isAccessible(env, types.erasure(t))) {
921 Symbol location = env.enclClass.sym;
922 reportMC(env.tree, MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
923 }
924 }
925 }
926
927 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
928 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
929 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
930 MethodCheckDiag methodDiag = varargsCheck ?
931 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
932
933 @Override
934 public void report(DiagnosticPosition pos, JCDiagnostic details) {
935 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
936 }
937 };
938 return new MethodResultInfo(to, checkContext);
939 }
940
941 @Override
942 public MethodCheck mostSpecificCheck(List<Type> actuals) {
943 return new MostSpecificCheck(actuals);
944 }
945
946 @Override
947 public String toString() {
948 return "resolveMethodCheck";
949 }
950 };
951
952 /**
953 * This class handles method reference applicability checks; since during
954 * these checks it's sometime possible to have inference variables on
955 * the actual argument types list, the method applicability check must be
956 * extended so that inference variables are 'opened' as needed.
957 */
958 class MethodReferenceCheck extends AbstractMethodCheck {
959
960 InferenceContext pendingInferenceContext;
961
962 MethodReferenceCheck(InferenceContext pendingInferenceContext) {
963 this.pendingInferenceContext = pendingInferenceContext;
964 }
965
966 @Override
967 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
968 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
969 mresult.check(pos, actual);
970 }
971
972 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
973 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
974 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
975 MethodCheckDiag methodDiag = varargsCheck ?
976 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
977
978 @Override
979 public boolean compatible(Type found, Type req, Warner warn) {
980 found = pendingInferenceContext.asUndetVar(found);
981 if (found.hasTag(UNDETVAR) && req.isPrimitive()) {
982 req = types.boxedClass(req).type;
983 }
984 return super.compatible(found, req, warn);
985 }
986
987 @Override
988 public void report(DiagnosticPosition pos, JCDiagnostic details) {
989 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
990 }
991 };
992 return new MethodResultInfo(to, checkContext);
993 }
994
995 @Override
996 public MethodCheck mostSpecificCheck(List<Type> actuals) {
997 return new MostSpecificCheck(actuals);
998 }
999
1000 @Override
1001 public String toString() {
1002 return "MethodReferenceCheck";
1003 }
1004 }
1005
1006 /**
1007 * Check context to be used during method applicability checks. A method check
1008 * context might contain inference variables.
1009 */
1010 abstract class MethodCheckContext implements CheckContext {
1011
1012 boolean strict;
1013 DeferredAttrContext deferredAttrContext;
1014 Warner rsWarner;
1015
1016 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) {
1017 this.strict = strict;
1018 this.deferredAttrContext = deferredAttrContext;
1019 this.rsWarner = rsWarner;
1020 }
1021
1022 public boolean compatible(Type found, Type req, Warner warn) {
1023 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
1024 return strict ?
1025 types.isSubtypeUnchecked(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn) :
1026 types.isConvertible(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn);
1027 }
1028
1029 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1030 throw new InapplicableMethodException(details);
1031 }
1032
1033 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
1034 return rsWarner;
1035 }
1036
1037 public InferenceContext inferenceContext() {
1038 return deferredAttrContext.inferenceContext;
1039 }
1040
1041 public DeferredAttrContext deferredAttrContext() {
1042 return deferredAttrContext;
1043 }
1044
1045 @Override
1046 public String toString() {
1047 return "MethodCheckContext";
1048 }
1049 }
1050
1051 /**
1052 * ResultInfo class to be used during method applicability checks. Check
1053 * for deferred types goes through special path.
1054 */
1055 class MethodResultInfo extends ResultInfo {
1056
1057 public MethodResultInfo(Type pt, CheckContext checkContext) {
1058 attr.super(KindSelector.VAL, pt, checkContext);
1059 }
1060
1061 @Override
1062 protected Type check(DiagnosticPosition pos, Type found) {
1063 if (found.hasTag(DEFERRED)) {
1064 DeferredType dt = (DeferredType)found;
1065 return dt.check(this);
1066 } else {
1067 Type uResult = U(found);
1068 Type capturedType = pos == null || pos.getTree() == null ?
1069 types.capture(uResult) :
1070 checkContext.inferenceContext()
1071 .cachedCapture(pos.getTree(), uResult, true);
1072 return super.check(pos, chk.checkNonVoid(pos, capturedType));
1073 }
1074 }
1075
1076 /**
1077 * javac has a long-standing 'simplification' (see 6391995):
1078 * given an actual argument type, the method check is performed
1079 * on its upper bound. This leads to inconsistencies when an
1080 * argument type is checked against itself. For example, given
1081 * a type-variable T, it is not true that {@code U(T) <: T},
1082 * so we need to guard against that.
1083 */
1084 private Type U(Type found) {
1085 return found == pt ?
1086 found : types.cvarUpperBound(found);
1087 }
1088
1089 @Override
1090 protected MethodResultInfo dup(Type newPt) {
1091 return new MethodResultInfo(newPt, checkContext);
1092 }
1093
1094 @Override
1095 protected ResultInfo dup(CheckContext newContext) {
1096 return new MethodResultInfo(pt, newContext);
1097 }
1098
1099 @Override
1100 protected ResultInfo dup(Type newPt, CheckContext newContext) {
1101 return new MethodResultInfo(newPt, newContext);
1102 }
1103 }
1104
1105 /**
1106 * Most specific method applicability routine. Given a list of actual types A,
1107 * a list of formal types F1, and a list of formal types F2, the routine determines
1108 * as to whether the types in F1 can be considered more specific than those in F2 w.r.t.
1109 * argument types A.
1110 */
1111 class MostSpecificCheck implements MethodCheck {
1112
1113 List<Type> actuals;
1114
1115 MostSpecificCheck(List<Type> actuals) {
1116 this.actuals = actuals;
1117 }
1118
1119 @Override
1120 public void argumentsAcceptable(final Env<AttrContext> env,
1121 DeferredAttrContext deferredAttrContext,
1122 List<Type> formals1,
1123 List<Type> formals2,
1124 Warner warn) {
1125 formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired());
1126 while (formals2.nonEmpty()) {
1127 ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head);
1128 mresult.check(null, formals1.head);
1129 formals1 = formals1.tail;
1130 formals2 = formals2.tail;
1131 actuals = actuals.isEmpty() ? actuals : actuals.tail;
1132 }
1133 }
1134
1135 /**
1136 * Create a method check context to be used during the most specific applicability check
1137 */
1138 ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext,
1139 Warner rsWarner, Type actual) {
1140 return attr.new ResultInfo(KindSelector.VAL, to,
1141 new MostSpecificCheckContext(deferredAttrContext, rsWarner, actual));
1142 }
1143
1144 /**
1145 * Subclass of method check context class that implements most specific
1146 * method conversion. If the actual type under analysis is a deferred type
1147 * a full blown structural analysis is carried out.
1148 */
1149 class MostSpecificCheckContext extends MethodCheckContext {
1150
1151 Type actual;
1152
1153 public MostSpecificCheckContext(DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) {
1154 super(true, deferredAttrContext, rsWarner);
1155 this.actual = actual;
1156 }
1157
1158 public boolean compatible(Type found, Type req, Warner warn) {
1159 if (allowFunctionalInterfaceMostSpecific &&
1160 unrelatedFunctionalInterfaces(found, req) &&
1161 (actual != null && actual.getTag() == DEFERRED)) {
1162 DeferredType dt = (DeferredType) actual;
1163 JCTree speculativeTree = dt.speculativeTree(deferredAttrContext);
1164 if (speculativeTree != deferredAttr.stuckTree) {
1165 return functionalInterfaceMostSpecific(found, req, speculativeTree);
1166 }
1167 }
1168 return compatibleBySubtyping(found, req);
1169 }
1170
1171 private boolean compatibleBySubtyping(Type found, Type req) {
1172 if (!strict && found.isPrimitive() != req.isPrimitive()) {
1173 found = found.isPrimitive() ? types.boxedClass(found).type : types.unboxedType(found);
1174 }
1175 return types.isSubtypeNoCapture(found, deferredAttrContext.inferenceContext.asUndetVar(req));
1176 }
1177
1178 /** Whether {@code t} and {@code s} are unrelated functional interface types. */
1179 private boolean unrelatedFunctionalInterfaces(Type t, Type s) {
1180 return types.isFunctionalInterface(t.tsym) &&
1181 types.isFunctionalInterface(s.tsym) &&
1182 unrelatedInterfaces(t, s);
1183 }
1184
1185 /** Whether {@code t} and {@code s} are unrelated interface types; recurs on intersections. **/
1186 private boolean unrelatedInterfaces(Type t, Type s) {
1187 if (t.isCompound()) {
1188 for (Type ti : types.interfaces(t)) {
1189 if (!unrelatedInterfaces(ti, s)) {
1190 return false;
1191 }
1192 }
1193 return true;
1194 } else if (s.isCompound()) {
1195 for (Type si : types.interfaces(s)) {
1196 if (!unrelatedInterfaces(t, si)) {
1197 return false;
1198 }
1199 }
1200 return true;
1201 } else {
1202 return types.asSuper(t, s.tsym) == null && types.asSuper(s, t.tsym) == null;
1203 }
1204 }
1205
1206 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */
1207 private boolean functionalInterfaceMostSpecific(Type t, Type s, JCTree tree) {
1208 Type tDesc = types.findDescriptorType(types.capture(t));
1209 Type tDescNoCapture = types.findDescriptorType(t);
1210 Type sDesc = types.findDescriptorType(s);
1211 final List<Type> tTypeParams = tDesc.getTypeArguments();
1212 final List<Type> tTypeParamsNoCapture = tDescNoCapture.getTypeArguments();
1213 final List<Type> sTypeParams = sDesc.getTypeArguments();
1214
1215 // compare type parameters
1216 if (tDesc.hasTag(FORALL) && !types.hasSameBounds((ForAll) tDesc, (ForAll) tDescNoCapture)) {
1217 return false;
1218 }
1219 // can't use Types.hasSameBounds on sDesc because bounds may have ivars
1220 List<Type> tIter = tTypeParams;
1221 List<Type> sIter = sTypeParams;
1222 while (tIter.nonEmpty() && sIter.nonEmpty()) {
1223 Type tBound = tIter.head.getUpperBound();
1224 Type sBound = types.subst(sIter.head.getUpperBound(), sTypeParams, tTypeParams);
1225 if (tBound.containsAny(tTypeParams) && inferenceContext().free(sBound)) {
1226 return false;
1227 }
1228 if (!types.isSameType(tBound, inferenceContext().asUndetVar(sBound))) {
1229 return false;
1230 }
1231 tIter = tIter.tail;
1232 sIter = sIter.tail;
1233 }
1234 if (!tIter.isEmpty() || !sIter.isEmpty()) {
1235 return false;
1236 }
1237
1238 // compare parameters
1239 List<Type> tParams = tDesc.getParameterTypes();
1240 List<Type> tParamsNoCapture = tDescNoCapture.getParameterTypes();
1241 List<Type> sParams = sDesc.getParameterTypes();
1242 while (tParams.nonEmpty() && tParamsNoCapture.nonEmpty() && sParams.nonEmpty()) {
1243 Type tParam = tParams.head;
1244 Type tParamNoCapture = types.subst(tParamsNoCapture.head, tTypeParamsNoCapture, tTypeParams);
1245 Type sParam = types.subst(sParams.head, sTypeParams, tTypeParams);
1246 if (tParam.containsAny(tTypeParams) && inferenceContext().free(sParam)) {
1247 return false;
1248 }
1249 if (!types.isSubtype(inferenceContext().asUndetVar(sParam), tParam)) {
1250 return false;
1251 }
1252 if (!types.isSameType(tParamNoCapture, inferenceContext().asUndetVar(sParam))) {
1253 return false;
1254 }
1255 tParams = tParams.tail;
1256 tParamsNoCapture = tParamsNoCapture.tail;
1257 sParams = sParams.tail;
1258 }
1259 if (!tParams.isEmpty() || !tParamsNoCapture.isEmpty() || !sParams.isEmpty()) {
1260 return false;
1261 }
1262
1263 // compare returns
1264 Type tRet = tDesc.getReturnType();
1265 Type sRet = types.subst(sDesc.getReturnType(), sTypeParams, tTypeParams);
1266 if (tRet.containsAny(tTypeParams) && inferenceContext().free(sRet)) {
1267 return false;
1268 }
1269 MostSpecificFunctionReturnChecker msc = new MostSpecificFunctionReturnChecker(tRet, sRet);
1270 msc.scan(tree);
1271 return msc.result;
1272 }
1273
1274 /**
1275 * Tests whether one functional interface type can be considered more specific
1276 * than another unrelated functional interface type for the scanned expression.
1277 */
1278 class MostSpecificFunctionReturnChecker extends DeferredAttr.PolyScanner {
1279
1280 final Type tRet;
1281 final Type sRet;
1282 boolean result;
1283
1284 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */
1285 MostSpecificFunctionReturnChecker(Type tRet, Type sRet) {
1286 this.tRet = tRet;
1287 this.sRet = sRet;
1288 result = true;
1289 }
1290
1291 @Override
1292 void skip(JCTree tree) {
1293 result &= false;
1294 }
1295
1296 @Override
1297 public void visitConditional(JCConditional tree) {
1298 scan(asExpr(tree.truepart));
1299 scan(asExpr(tree.falsepart));
1300 }
1301
1302 @Override
1303 public void visitReference(JCMemberReference tree) {
1304 if (sRet.hasTag(VOID)) {
1305 result &= true;
1306 } else if (tRet.hasTag(VOID)) {
1307 result &= false;
1308 } else if (tRet.isPrimitive() != sRet.isPrimitive()) {
1309 boolean retValIsPrimitive =
1310 tree.refPolyKind == PolyKind.STANDALONE &&
1311 tree.sym.type.getReturnType().isPrimitive();
1312 result &= (retValIsPrimitive == tRet.isPrimitive()) &&
1313 (retValIsPrimitive != sRet.isPrimitive());
1314 } else {
1315 result &= compatibleBySubtyping(tRet, sRet);
1316 }
1317 }
1318
1319 @Override
1320 public void visitParens(JCParens tree) {
1321 scan(asExpr(tree.expr));
1322 }
1323
1324 @Override
1325 public void visitLambda(JCLambda tree) {
1326 if (sRet.hasTag(VOID)) {
1327 result &= true;
1328 } else if (tRet.hasTag(VOID)) {
1329 result &= false;
1330 } else {
1331 List<JCExpression> lambdaResults = lambdaResults(tree);
1332 if (!lambdaResults.isEmpty() && unrelatedFunctionalInterfaces(tRet, sRet)) {
1333 for (JCExpression expr : lambdaResults) {
1334 result &= functionalInterfaceMostSpecific(tRet, sRet, expr);
1335 }
1336 } else if (!lambdaResults.isEmpty() && tRet.isPrimitive() != sRet.isPrimitive()) {
1337 for (JCExpression expr : lambdaResults) {
1338 boolean retValIsPrimitive = expr.isStandalone() && expr.type.isPrimitive();
1339 result &= (retValIsPrimitive == tRet.isPrimitive()) &&
1340 (retValIsPrimitive != sRet.isPrimitive());
1341 }
1342 } else {
1343 result &= compatibleBySubtyping(tRet, sRet);
1344 }
1345 }
1346 }
1347 //where
1348
1349 private List<JCExpression> lambdaResults(JCLambda lambda) {
1350 if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) {
1351 return List.of(asExpr((JCExpression) lambda.body));
1352 } else {
1353 final ListBuffer<JCExpression> buffer = new ListBuffer<>();
1354 DeferredAttr.LambdaReturnScanner lambdaScanner =
1355 new DeferredAttr.LambdaReturnScanner() {
1356 @Override
1357 public void visitReturn(JCReturn tree) {
1358 if (tree.expr != null) {
1359 buffer.append(asExpr(tree.expr));
1360 }
1361 }
1362 };
1363 lambdaScanner.scan(lambda.body);
1364 return buffer.toList();
1365 }
1366 }
1367
1368 private JCExpression asExpr(JCExpression expr) {
1369 if (expr.type.hasTag(DEFERRED)) {
1370 JCTree speculativeTree = ((DeferredType)expr.type).speculativeTree(deferredAttrContext);
1371 if (speculativeTree != deferredAttr.stuckTree) {
1372 expr = (JCExpression)speculativeTree;
1373 }
1374 }
1375 return expr;
1376 }
1377 }
1378
1379 }
1380
1381 public MethodCheck mostSpecificCheck(List<Type> actuals) {
1382 Assert.error("Cannot get here!");
1383 return null;
1384 }
1385 }
1386
1387 public static class InapplicableMethodException extends RuntimeException {
1388 private static final long serialVersionUID = 0;
1389
1390 transient JCDiagnostic diagnostic;
1391
1392 InapplicableMethodException(JCDiagnostic diag) {
1393 this.diagnostic = diag;
1394 }
1395
1396 public JCDiagnostic getDiagnostic() {
1397 return diagnostic;
1398 }
1399 }
1400
1401 /* ***************************************************************************
1402 * Symbol lookup
1403 * the following naming conventions for arguments are used
1404 *
1405 * env is the environment where the symbol was mentioned
1406 * site is the type of which the symbol is a member
1407 * name is the symbol's name
1408 * if no arguments are given
1409 * argtypes are the value arguments, if we search for a method
1410 *
1411 * If no symbol was found, a ResolveError detailing the problem is returned.
1412 ****************************************************************************/
1413
1414 /** Find field. Synthetic fields are always skipped.
1415 * @param env The current environment.
1416 * @param site The original type from where the selection takes place.
1417 * @param name The name of the field.
1418 * @param c The class to search for the field. This is always
1419 * a superclass or implemented interface of site's class.
1420 */
1421 Symbol findField(Env<AttrContext> env,
1422 Type site,
1423 Name name,
1424 TypeSymbol c) {
1425 while (c.type.hasTag(TYPEVAR))
1426 c = c.type.getUpperBound().tsym;
1427 Symbol bestSoFar = varNotFound;
1428 Symbol sym;
1429 for (Symbol s : c.members().getSymbolsByName(name)) {
1430 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) {
1431 return isAccessible(env, site, s)
1432 ? s : new AccessError(env, site, s);
1433 }
1434 }
1435 Type st = types.supertype(c.type);
1436 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) {
1437 sym = findField(env, site, name, st.tsym);
1438 bestSoFar = bestOf(bestSoFar, sym);
1439 }
1440 for (List<Type> l = types.interfaces(c.type);
1441 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1442 l = l.tail) {
1443 sym = findField(env, site, name, l.head.tsym);
1444 if (bestSoFar.exists() && sym.exists() &&
1445 sym.owner != bestSoFar.owner)
1446 bestSoFar = new AmbiguityError(bestSoFar, sym);
1447 else
1448 bestSoFar = bestOf(bestSoFar, sym);
1449 }
1450 return bestSoFar;
1451 }
1452
1453 /** Resolve a field identifier, throw a fatal error if not found.
1454 * @param pos The position to use for error reporting.
1455 * @param env The environment current at the method invocation.
1456 * @param site The type of the qualifying expression, in which
1457 * identifier is searched.
1458 * @param name The identifier's name.
1459 */
1460 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
1461 Type site, Name name) {
1462 Symbol sym = findField(env, site, name, site.tsym);
1463 if (sym.kind == VAR) return (VarSymbol)sym;
1464 else throw new FatalError(
1465 diags.fragment(Fragments.FatalErrCantLocateField(name)));
1466 }
1467
1468 /** Find unqualified variable or field with given name.
1469 * Synthetic fields always skipped.
1470 * @param env The current environment.
1471 * @param name The name of the variable or field.
1472 */
1473 Symbol findVar(Env<AttrContext> env, Name name) {
1474 Symbol bestSoFar = varNotFound;
1475 Env<AttrContext> env1 = env;
1476 boolean staticOnly = false;
1477 while (env1.outer != null) {
1478 Symbol sym = null;
1479 if (isStatic(env1)) staticOnly = true;
1480 for (Symbol s : env1.info.scope.getSymbolsByName(name)) {
1481 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) {
1482 sym = s;
1483 break;
1484 }
1485 }
1486 if (sym == null) {
1487 sym = findField(env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
1488 }
1489 if (sym.exists()) {
1490 if (staticOnly &&
1491 sym.kind == VAR &&
1492 sym.owner.kind == TYP &&
1493 (sym.flags() & STATIC) == 0)
1494 return new StaticError(sym);
1495 else
1496 return sym;
1497 } else {
1498 bestSoFar = bestOf(bestSoFar, sym);
1499 }
1500
1501 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1502 env1 = env1.outer;
1503 }
1504
1505 Symbol sym = findField(env, syms.predefClass.type, name, syms.predefClass);
1506 if (sym.exists())
1507 return sym;
1508 if (bestSoFar.exists())
1509 return bestSoFar;
1510
1511 Symbol origin = null;
1512 for (Scope sc : new Scope[] { env.toplevel.namedImportScope, env.toplevel.starImportScope }) {
1513 for (Symbol currentSymbol : sc.getSymbolsByName(name)) {
1514 if (currentSymbol.kind != VAR)
1515 continue;
1516 // invariant: sym.kind == Symbol.Kind.VAR
1517 if (!bestSoFar.kind.isResolutionError() &&
1518 currentSymbol.owner != bestSoFar.owner)
1519 return new AmbiguityError(bestSoFar, currentSymbol);
1520 else if (!bestSoFar.kind.betterThan(VAR)) {
1521 origin = sc.getOrigin(currentSymbol).owner;
1522 bestSoFar = isAccessible(env, origin.type, currentSymbol)
1523 ? currentSymbol : new AccessError(env, origin.type, currentSymbol);
1524 }
1525 }
1526 if (bestSoFar.exists()) break;
1527 }
1528 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
1529 return bestSoFar.clone(origin);
1530 else
1531 return bestSoFar;
1532 }
1533
1534 Warner noteWarner = new Warner();
1535
1536 /** Select the best method for a call site among two choices.
1537 * @param env The current environment.
1538 * @param site The original type from where the
1539 * selection takes place.
1540 * @param argtypes The invocation's value arguments,
1541 * @param typeargtypes The invocation's type arguments,
1542 * @param sym Proposed new best match.
1543 * @param bestSoFar Previously found best match.
1544 * @param allowBoxing Allow boxing conversions of arguments.
1545 * @param useVarargs Box trailing arguments into an array for varargs.
1546 */
1547 @SuppressWarnings("fallthrough")
1548 Symbol selectBest(Env<AttrContext> env,
1549 Type site,
1550 List<Type> argtypes,
1551 List<Type> typeargtypes,
1552 Symbol sym,
1553 Symbol bestSoFar,
1554 boolean allowBoxing,
1555 boolean useVarargs) {
1556 if (sym.kind == ERR ||
1557 (site.tsym != sym.owner && !sym.isInheritedIn(site.tsym, types)) ||
1558 !notOverriddenIn(site, sym)) {
1559 return bestSoFar;
1560 } else if (useVarargs && (sym.flags() & VARARGS) == 0) {
1561 return bestSoFar.kind.isResolutionError() ?
1562 new BadVarargsMethod((ResolveError)bestSoFar.baseSymbol()) :
1563 bestSoFar;
1564 }
1565 Assert.check(!sym.kind.isResolutionError());
1566 try {
1567 types.noWarnings.clear();
1568 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes,
1569 allowBoxing, useVarargs, types.noWarnings);
1570 currentResolutionContext.addApplicableCandidate(sym, mt);
1571 } catch (InapplicableMethodException ex) {
1572 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic());
1573 switch (bestSoFar.kind) {
1574 case ABSENT_MTH:
1575 return new InapplicableSymbolError(currentResolutionContext);
1576 case WRONG_MTH:
1577 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1578 default:
1579 return bestSoFar;
1580 }
1581 }
1582 if (!isAccessible(env, site, sym)) {
1583 return (bestSoFar.kind == ABSENT_MTH)
1584 ? new AccessError(env, site, sym)
1585 : bestSoFar;
1586 }
1587 return (bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS)
1588 ? sym
1589 : mostSpecific(argtypes, sym, bestSoFar, env, site, useVarargs);
1590 }
1591
1592 /* Return the most specific of the two methods for a call,
1593 * given that both are accessible and applicable.
1594 * @param m1 A new candidate for most specific.
1595 * @param m2 The previous most specific candidate.
1596 * @param env The current environment.
1597 * @param site The original type from where the selection
1598 * takes place.
1599 * @param allowBoxing Allow boxing conversions of arguments.
1600 * @param useVarargs Box trailing arguments into an array for varargs.
1601 */
1602 Symbol mostSpecific(List<Type> argtypes, Symbol m1,
1603 Symbol m2,
1604 Env<AttrContext> env,
1605 final Type site,
1606 boolean useVarargs) {
1607 switch (m2.kind) {
1608 case MTH:
1609 if (m1 == m2) return m1;
1610 boolean m1SignatureMoreSpecific =
1611 signatureMoreSpecific(argtypes, env, site, m1, m2, useVarargs);
1612 boolean m2SignatureMoreSpecific =
1613 signatureMoreSpecific(argtypes, env, site, m2, m1, useVarargs);
1614 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
1615 Type mt1 = types.memberType(site, m1);
1616 Type mt2 = types.memberType(site, m2);
1617 if (!types.overrideEquivalent(mt1, mt2))
1618 return ambiguityError(m1, m2);
1619
1620 // same signature; select (a) the non-bridge method, or
1621 // (b) the one that overrides the other, or (c) the concrete
1622 // one, or (d) merge both abstract signatures
1623 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
1624 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
1625
1626 if (m1.baseSymbol() == m2.baseSymbol()) {
1627 // this is the same imported symbol which has been cloned twice.
1628 // Return the first one (either will do).
1629 return m1;
1630 }
1631
1632 // if one overrides or hides the other, use it
1633 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
1634 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
1635 // the two owners can never be the same if the target methods are compiled from source,
1636 // but we need to protect against cases where the methods are defined in some classfile
1637 // and make sure we issue an ambiguity error accordingly (by skipping the logic below).
1638 if (m1Owner != m2Owner) {
1639 if (types.asSuper(m1Owner.type, m2Owner) != null &&
1640 ((m1.owner.flags_field & INTERFACE) == 0 ||
1641 (m2.owner.flags_field & INTERFACE) != 0) &&
1642 m1.overrides(m2, m1Owner, types, false))
1643 return m1;
1644 if (types.asSuper(m2Owner.type, m1Owner) != null &&
1645 ((m2.owner.flags_field & INTERFACE) == 0 ||
1646 (m1.owner.flags_field & INTERFACE) != 0) &&
1647 m2.overrides(m1, m2Owner, types, false))
1648 return m2;
1649 }
1650 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
1651 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
1652 if (m1Abstract && !m2Abstract) return m2;
1653 if (m2Abstract && !m1Abstract) return m1;
1654 // both abstract or both concrete
1655 return ambiguityError(m1, m2);
1656 }
1657 if (m1SignatureMoreSpecific) return m1;
1658 if (m2SignatureMoreSpecific) return m2;
1659 return ambiguityError(m1, m2);
1660 case AMBIGUOUS:
1661 //compare m1 to ambiguous methods in m2
1662 AmbiguityError e = (AmbiguityError)m2.baseSymbol();
1663 boolean m1MoreSpecificThanAnyAmbiguous = true;
1664 boolean allAmbiguousMoreSpecificThanM1 = true;
1665 for (Symbol s : e.ambiguousSyms) {
1666 Symbol moreSpecific = mostSpecific(argtypes, m1, s, env, site, useVarargs);
1667 m1MoreSpecificThanAnyAmbiguous &= moreSpecific == m1;
1668 allAmbiguousMoreSpecificThanM1 &= moreSpecific == s;
1669 }
1670 if (m1MoreSpecificThanAnyAmbiguous)
1671 return m1;
1672 //if m1 is more specific than some ambiguous methods, but other ambiguous methods are
1673 //more specific than m1, add it as a new ambiguous method:
1674 if (!allAmbiguousMoreSpecificThanM1)
1675 e.addAmbiguousSymbol(m1);
1676 return e;
1677 default:
1678 throw new AssertionError();
1679 }
1680 }
1681 //where
1682 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean useVarargs) {
1683 noteWarner.clear();
1684 int maxLength = Math.max(
1685 Math.max(m1.type.getParameterTypes().length(), actuals.length()),
1686 m2.type.getParameterTypes().length());
1687 MethodResolutionContext prevResolutionContext = currentResolutionContext;
1688 try {
1689 currentResolutionContext = new MethodResolutionContext();
1690 currentResolutionContext.step = prevResolutionContext.step;
1691 currentResolutionContext.methodCheck =
1692 prevResolutionContext.methodCheck.mostSpecificCheck(actuals);
1693 Type mst = instantiate(env, site, m2, null,
1694 adjustArgs(types.cvarLowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null,
1695 false, useVarargs, noteWarner);
1696 return mst != null &&
1697 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
1698 } finally {
1699 currentResolutionContext = prevResolutionContext;
1700 }
1701 }
1702
1703 List<Type> adjustArgs(List<Type> args, Symbol msym, int length, boolean allowVarargs) {
1704 if ((msym.flags() & VARARGS) != 0 && allowVarargs) {
1705 Type varargsElem = types.elemtype(args.last());
1706 if (varargsElem == null) {
1707 Assert.error("Bad varargs = " + args.last() + " " + msym);
1708 }
1709 List<Type> newArgs = args.reverse().tail.prepend(varargsElem).reverse();
1710 while (newArgs.length() < length) {
1711 newArgs = newArgs.append(newArgs.last());
1712 }
1713 return newArgs;
1714 } else {
1715 return args;
1716 }
1717 }
1718 //where
1719 Symbol ambiguityError(Symbol m1, Symbol m2) {
1720 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
1721 return (m1.flags() & CLASH) == 0 ? m1 : m2;
1722 } else {
1723 return new AmbiguityError(m1, m2);
1724 }
1725 }
1726
1727 Symbol findMethodInScope(Env<AttrContext> env,
1728 Type site,
1729 Name name,
1730 List<Type> argtypes,
1731 List<Type> typeargtypes,
1732 Scope sc,
1733 Symbol bestSoFar,
1734 boolean allowBoxing,
1735 boolean useVarargs,
1736 boolean abstractok) {
1737 for (Symbol s : sc.getSymbolsByName(name, new LookupFilter(abstractok))) {
1738 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s,
1739 bestSoFar, allowBoxing, useVarargs);
1740 }
1741 return bestSoFar;
1742 }
1743 //where
1744 class LookupFilter implements Filter<Symbol> {
1745
1746 boolean abstractOk;
1747
1748 LookupFilter(boolean abstractOk) {
1749 this.abstractOk = abstractOk;
1750 }
1751
1752 public boolean accepts(Symbol s) {
1753 long flags = s.flags();
1754 return s.kind == MTH &&
1755 (flags & SYNTHETIC) == 0 &&
1756 (abstractOk ||
1757 (flags & DEFAULT) != 0 ||
1758 (flags & ABSTRACT) == 0);
1759 }
1760 }
1761
1762 /** Find best qualified method matching given name, type and value
1763 * arguments.
1764 * @param env The current environment.
1765 * @param site The original type from where the selection
1766 * takes place.
1767 * @param name The method's name.
1768 * @param argtypes The method's value arguments.
1769 * @param typeargtypes The method's type arguments
1770 * @param allowBoxing Allow boxing conversions of arguments.
1771 * @param useVarargs Box trailing arguments into an array for varargs.
1772 */
1773 Symbol findMethod(Env<AttrContext> env,
1774 Type site,
1775 Name name,
1776 List<Type> argtypes,
1777 List<Type> typeargtypes,
1778 boolean allowBoxing,
1779 boolean useVarargs) {
1780 Symbol bestSoFar = methodNotFound;
1781 bestSoFar = findMethod(env,
1782 site,
1783 name,
1784 argtypes,
1785 typeargtypes,
1786 site.tsym.type,
1787 bestSoFar,
1788 allowBoxing,
1789 useVarargs);
1790 return bestSoFar;
1791 }
1792 // where
1793 private Symbol findMethod(Env<AttrContext> env,
1794 Type site,
1795 Name name,
1796 List<Type> argtypes,
1797 List<Type> typeargtypes,
1798 Type intype,
1799 Symbol bestSoFar,
1800 boolean allowBoxing,
1801 boolean useVarargs) {
1802 @SuppressWarnings({"unchecked","rawtypes"})
1803 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() };
1804
1805 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK;
1806 for (TypeSymbol s : superclasses(intype)) {
1807 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1808 s.members(), bestSoFar, allowBoxing, useVarargs, true);
1809 if (name == names.init) return bestSoFar;
1810 iphase = (iphase == null) ? null : iphase.update(s, this);
1811 if (iphase != null) {
1812 for (Type itype : types.interfaces(s.type)) {
1813 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]);
1814 }
1815 }
1816 }
1817
1818 Symbol concrete = bestSoFar.kind.isValid() &&
1819 (bestSoFar.flags() & ABSTRACT) == 0 ?
1820 bestSoFar : methodNotFound;
1821
1822 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) {
1823 //keep searching for abstract methods
1824 for (Type itype : itypes[iphase2.ordinal()]) {
1825 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure())
1826 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK &&
1827 (itype.tsym.flags() & DEFAULT) == 0) continue;
1828 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1829 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, true);
1830 if (concrete != bestSoFar &&
1831 concrete.kind.isValid() &&
1832 bestSoFar.kind.isValid() &&
1833 types.isSubSignature(concrete.type, bestSoFar.type)) {
1834 //this is an hack - as javac does not do full membership checks
1835 //most specific ends up comparing abstract methods that might have
1836 //been implemented by some concrete method in a subclass and,
1837 //because of raw override, it is possible for an abstract method
1838 //to be more specific than the concrete method - so we need
1839 //to explicitly call that out (see CR 6178365)
1840 bestSoFar = concrete;
1841 }
1842 }
1843 }
1844 return bestSoFar;
1845 }
1846
1847 enum InterfaceLookupPhase {
1848 ABSTRACT_OK() {
1849 @Override
1850 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1851 //We should not look for abstract methods if receiver is a concrete class
1852 //(as concrete classes are expected to implement all abstracts coming
1853 //from superinterfaces)
1854 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) {
1855 return this;
1856 } else {
1857 return DEFAULT_OK;
1858 }
1859 }
1860 },
1861 DEFAULT_OK() {
1862 @Override
1863 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1864 return this;
1865 }
1866 };
1867
1868 abstract InterfaceLookupPhase update(Symbol s, Resolve rs);
1869 }
1870
1871 /**
1872 * Return an Iterable object to scan the superclasses of a given type.
1873 * It's crucial that the scan is done lazily, as we don't want to accidentally
1874 * access more supertypes than strictly needed (as this could trigger completion
1875 * errors if some of the not-needed supertypes are missing/ill-formed).
1876 */
1877 Iterable<TypeSymbol> superclasses(final Type intype) {
1878 return () -> new Iterator<TypeSymbol>() {
1879
1880 List<TypeSymbol> seen = List.nil();
1881 TypeSymbol currentSym = symbolFor(intype);
1882 TypeSymbol prevSym = null;
1883
1884 public boolean hasNext() {
1885 if (currentSym == syms.noSymbol) {
1886 currentSym = symbolFor(types.supertype(prevSym.type));
1887 }
1888 return currentSym != null;
1889 }
1890
1891 public TypeSymbol next() {
1892 prevSym = currentSym;
1893 currentSym = syms.noSymbol;
1894 Assert.check(prevSym != null || prevSym != syms.noSymbol);
1895 return prevSym;
1896 }
1897
1898 public void remove() {
1899 throw new UnsupportedOperationException();
1900 }
1901
1902 TypeSymbol symbolFor(Type t) {
1903 if (!t.hasTag(CLASS) &&
1904 !t.hasTag(TYPEVAR)) {
1905 return null;
1906 }
1907 t = types.skipTypeVars(t, false);
1908 if (seen.contains(t.tsym)) {
1909 //degenerate case in which we have a circular
1910 //class hierarchy - because of ill-formed classfiles
1911 return null;
1912 }
1913 seen = seen.prepend(t.tsym);
1914 return t.tsym;
1915 }
1916 };
1917 }
1918
1919 /** Find unqualified method matching given name, type and value arguments.
1920 * @param env The current environment.
1921 * @param name The method's name.
1922 * @param argtypes The method's value arguments.
1923 * @param typeargtypes The method's type arguments.
1924 * @param allowBoxing Allow boxing conversions of arguments.
1925 * @param useVarargs Box trailing arguments into an array for varargs.
1926 */
1927 Symbol findFun(Env<AttrContext> env, Name name,
1928 List<Type> argtypes, List<Type> typeargtypes,
1929 boolean allowBoxing, boolean useVarargs) {
1930 Symbol bestSoFar = methodNotFound;
1931 Env<AttrContext> env1 = env;
1932 boolean staticOnly = false;
1933 while (env1.outer != null) {
1934 if (isStatic(env1)) staticOnly = true;
1935 Assert.check(env1.info.preferredTreeForDiagnostics == null);
1936 env1.info.preferredTreeForDiagnostics = env.tree;
1937 try {
1938 Symbol sym = findMethod(
1939 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
1940 allowBoxing, useVarargs);
1941 if (sym.exists()) {
1942 if (staticOnly &&
1943 sym.kind == MTH &&
1944 sym.owner.kind == TYP &&
1945 (sym.flags() & STATIC) == 0) return new StaticError(sym);
1946 else return sym;
1947 } else {
1948 bestSoFar = bestOf(bestSoFar, sym);
1949 }
1950 } finally {
1951 env1.info.preferredTreeForDiagnostics = null;
1952 }
1953 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1954 env1 = env1.outer;
1955 }
1956
1957 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
1958 typeargtypes, allowBoxing, useVarargs);
1959 if (sym.exists())
1960 return sym;
1961
1962 for (Symbol currentSym : env.toplevel.namedImportScope.getSymbolsByName(name)) {
1963 Symbol origin = env.toplevel.namedImportScope.getOrigin(currentSym).owner;
1964 if (currentSym.kind == MTH) {
1965 if (currentSym.owner.type != origin.type)
1966 currentSym = currentSym.clone(origin);
1967 if (!isAccessible(env, origin.type, currentSym))
1968 currentSym = new AccessError(env, origin.type, currentSym);
1969 bestSoFar = selectBest(env, origin.type,
1970 argtypes, typeargtypes,
1971 currentSym, bestSoFar,
1972 allowBoxing, useVarargs);
1973 }
1974 }
1975 if (bestSoFar.exists())
1976 return bestSoFar;
1977
1978 for (Symbol currentSym : env.toplevel.starImportScope.getSymbolsByName(name)) {
1979 Symbol origin = env.toplevel.starImportScope.getOrigin(currentSym).owner;
1980 if (currentSym.kind == MTH) {
1981 if (currentSym.owner.type != origin.type)
1982 currentSym = currentSym.clone(origin);
1983 if (!isAccessible(env, origin.type, currentSym))
1984 currentSym = new AccessError(env, origin.type, currentSym);
1985 bestSoFar = selectBest(env, origin.type,
1986 argtypes, typeargtypes,
1987 currentSym, bestSoFar,
1988 allowBoxing, useVarargs);
1989 }
1990 }
1991 return bestSoFar;
1992 }
1993
1994 /** Load toplevel or member class with given fully qualified name and
1995 * verify that it is accessible.
1996 * @param env The current environment.
1997 * @param name The fully qualified name of the class to be loaded.
1998 */
1999 Symbol loadClass(Env<AttrContext> env, Name name, RecoveryLoadClass recoveryLoadClass) {
2000 try {
2001 ClassSymbol c = finder.loadClass(env.toplevel.modle, name);
2002 return isAccessible(env, c) ? c : new AccessError(env, null, c);
2003 } catch (ClassFinder.BadClassFile err) {
2004 return new BadClassFileError(err);
2005 } catch (CompletionFailure ex) {
2006 Symbol candidate = recoveryLoadClass.loadClass(env, name);
2007
2008 if (candidate != null) {
2009 return candidate;
2010 }
2011
2012 return typeNotFound;
2013 }
2014 }
2015
2016 public interface RecoveryLoadClass {
2017 Symbol loadClass(Env<AttrContext> env, Name name);
2018 }
2019
2020 private final RecoveryLoadClass noRecovery = (env, name) -> null;
2021
2022 private final RecoveryLoadClass doRecoveryLoadClass = new RecoveryLoadClass() {
2023 @Override public Symbol loadClass(Env<AttrContext> env, Name name) {
2024 List<Name> candidates = Convert.classCandidates(name);
2025 return lookupInvisibleSymbol(env, name,
2026 n -> () -> createCompoundIterator(candidates,
2027 c -> syms.getClassesForName(c)
2028 .iterator()),
2029 (ms, n) -> {
2030 for (Name candidate : candidates) {
2031 try {
2032 return finder.loadClass(ms, candidate);
2033 } catch (CompletionFailure cf) {
2034 //ignore
2035 }
2036 }
2037 return null;
2038 }, sym -> sym.kind == Kind.TYP, typeNotFound);
2039 }
2040 };
2041
2042 private final RecoveryLoadClass namedImportScopeRecovery = (env, name) -> {
2043 Scope importScope = env.toplevel.namedImportScope;
2044 Symbol existing = importScope.findFirst(Convert.shortName(name),
2045 sym -> sym.kind == TYP && sym.flatName() == name);
2046
2047 if (existing != null) {
2048 return new InvisibleSymbolError(env, true, existing);
2049 }
2050 return null;
2051 };
2052
2053 private final RecoveryLoadClass starImportScopeRecovery = (env, name) -> {
2054 Scope importScope = env.toplevel.starImportScope;
2055 Symbol existing = importScope.findFirst(Convert.shortName(name),
2056 sym -> sym.kind == TYP && sym.flatName() == name);
2057
2058 if (existing != null) {
2059 try {
2060 existing = finder.loadClass(existing.packge().modle, name);
2061
2062 return new InvisibleSymbolError(env, true, existing);
2063 } catch (CompletionFailure cf) {
2064 //ignore
2065 }
2066 }
2067
2068 return null;
2069 };
2070
2071 Symbol lookupPackage(Env<AttrContext> env, Name name) {
2072 PackageSymbol pack = syms.lookupPackage(env.toplevel.modle, name);
2073
2074 if (allowModules && isImportOnDemand(env, name)) {
2075 if (pack.members().isEmpty()) {
2076 return lookupInvisibleSymbol(env, name, syms::getPackagesForName, syms::enterPackage, sym -> {
2077 sym.complete();
2078 return !sym.members().isEmpty();
2079 }, pack);
2080 }
2081 }
2082
2083 return pack;
2084 }
2085
2086 private boolean isImportOnDemand(Env<AttrContext> env, Name name) {
2087 if (!env.tree.hasTag(IMPORT))
2088 return false;
2089
2090 JCTree qualid = ((JCImport) env.tree).qualid;
2091
2092 if (!qualid.hasTag(SELECT))
2093 return false;
2094
2095 if (TreeInfo.name(qualid) != names.asterisk)
2096 return false;
2097
2098 return TreeInfo.fullName(((JCFieldAccess) qualid).selected) == name;
2099 }
2100
2101 private <S extends Symbol> Symbol lookupInvisibleSymbol(Env<AttrContext> env,
2102 Name name,
2103 Function<Name, Iterable<S>> get,
2104 BiFunction<ModuleSymbol, Name, S> load,
2105 Predicate<S> validate,
2106 Symbol defaultResult) {
2107 //even if a class/package cannot be found in the current module and among packages in modules
2108 //it depends on that are exported for any or this module, the class/package may exist internally
2109 //in some of these modules, or may exist in a module on which this module does not depend.
2110 //Provide better diagnostic in such cases by looking for the class in any module:
2111 Iterable<? extends S> candidates = get.apply(name);
2112
2113 for (S sym : candidates) {
2114 if (validate.test(sym))
2115 return createInvisibleSymbolError(env, sym);
2116 }
2117
2118 Set<ModuleSymbol> recoverableModules = new HashSet<>(syms.getAllModules());
2119
2120 recoverableModules.add(syms.unnamedModule);
2121 recoverableModules.remove(env.toplevel.modle);
2122
2123 for (ModuleSymbol ms : recoverableModules) {
2124 //avoid overly eager completing classes from source-based modules, as those
2125 //may not be completable with the current compiler settings:
2126 if (ms.sourceLocation == null) {
2127 if (ms.classLocation == null) {
2128 ms = moduleFinder.findModule(ms);
2129 }
2130
2131 if (ms.kind != ERR) {
2132 S sym = load.apply(ms, name);
2133
2134 if (sym != null && validate.test(sym)) {
2135 return createInvisibleSymbolError(env, sym);
2136 }
2137 }
2138 }
2139 }
2140
2141 return defaultResult;
2142 }
2143
2144 private Symbol createInvisibleSymbolError(Env<AttrContext> env, Symbol sym) {
2145 if (symbolPackageVisible(env, sym)) {
2146 return new AccessError(env, null, sym);
2147 } else {
2148 return new InvisibleSymbolError(env, false, sym);
2149 }
2150 }
2151
2152 private boolean symbolPackageVisible(Env<AttrContext> env, Symbol sym) {
2153 ModuleSymbol envMod = env.toplevel.modle;
2154 PackageSymbol symPack = sym.packge();
2155 return envMod == symPack.modle ||
2156 envMod.visiblePackages.containsKey(symPack.fullname);
2157 }
2158
2159 /**
2160 * Find a type declared in a scope (not inherited). Return null
2161 * if none is found.
2162 * @param env The current environment.
2163 * @param site The original type from where the selection takes
2164 * place.
2165 * @param name The type's name.
2166 * @param c The class to search for the member type. This is
2167 * always a superclass or implemented interface of
2168 * site's class.
2169 */
2170 Symbol findImmediateMemberType(Env<AttrContext> env,
2171 Type site,
2172 Name name,
2173 TypeSymbol c) {
2174 for (Symbol sym : c.members().getSymbolsByName(name)) {
2175 if (sym.kind == TYP) {
2176 return isAccessible(env, site, sym)
2177 ? sym
2178 : new AccessError(env, site, sym);
2179 }
2180 }
2181 return typeNotFound;
2182 }
2183
2184 /** Find a member type inherited from a superclass or interface.
2185 * @param env The current environment.
2186 * @param site The original type from where the selection takes
2187 * place.
2188 * @param name The type's name.
2189 * @param c The class to search for the member type. This is
2190 * always a superclass or implemented interface of
2191 * site's class.
2192 */
2193 Symbol findInheritedMemberType(Env<AttrContext> env,
2194 Type site,
2195 Name name,
2196 TypeSymbol c) {
2197 Symbol bestSoFar = typeNotFound;
2198 Symbol sym;
2199 Type st = types.supertype(c.type);
2200 if (st != null && st.hasTag(CLASS)) {
2201 sym = findMemberType(env, site, name, st.tsym);
2202 bestSoFar = bestOf(bestSoFar, sym);
2203 }
2204 for (List<Type> l = types.interfaces(c.type);
2205 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
2206 l = l.tail) {
2207 sym = findMemberType(env, site, name, l.head.tsym);
2208 if (!bestSoFar.kind.isResolutionError() &&
2209 !sym.kind.isResolutionError() &&
2210 sym.owner != bestSoFar.owner)
2211 bestSoFar = new AmbiguityError(bestSoFar, sym);
2212 else
2213 bestSoFar = bestOf(bestSoFar, sym);
2214 }
2215 return bestSoFar;
2216 }
2217
2218 /** Find qualified member type.
2219 * @param env The current environment.
2220 * @param site The original type from where the selection takes
2221 * place.
2222 * @param name The type's name.
2223 * @param c The class to search for the member type. This is
2224 * always a superclass or implemented interface of
2225 * site's class.
2226 */
2227 Symbol findMemberType(Env<AttrContext> env,
2228 Type site,
2229 Name name,
2230 TypeSymbol c) {
2231 Symbol sym = findImmediateMemberType(env, site, name, c);
2232
2233 if (sym != typeNotFound)
2234 return sym;
2235
2236 return findInheritedMemberType(env, site, name, c);
2237
2238 }
2239
2240 /** Find a global type in given scope and load corresponding class.
2241 * @param env The current environment.
2242 * @param scope The scope in which to look for the type.
2243 * @param name The type's name.
2244 */
2245 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name, RecoveryLoadClass recoveryLoadClass) {
2246 Symbol bestSoFar = typeNotFound;
2247 for (Symbol s : scope.getSymbolsByName(name)) {
2248 Symbol sym = loadClass(env, s.flatName(), recoveryLoadClass);
2249 if (bestSoFar.kind == TYP && sym.kind == TYP &&
2250 bestSoFar != sym)
2251 return new AmbiguityError(bestSoFar, sym);
2252 else
2253 bestSoFar = bestOf(bestSoFar, sym);
2254 }
2255 return bestSoFar;
2256 }
2257
2258 Symbol findTypeVar(Env<AttrContext> env, Name name, boolean staticOnly) {
2259 for (Symbol sym : env.info.scope.getSymbolsByName(name)) {
2260 if (sym.kind == TYP) {
2261 if (staticOnly &&
2262 sym.type.hasTag(TYPEVAR) &&
2263 sym.owner.kind == TYP)
2264 return new StaticError(sym);
2265 return sym;
2266 }
2267 }
2268 return typeNotFound;
2269 }
2270
2271 /** Find an unqualified type symbol.
2272 * @param env The current environment.
2273 * @param name The type's name.
2274 */
2275 Symbol findType(Env<AttrContext> env, Name name) {
2276 if (name == names.empty)
2277 return typeNotFound; // do not allow inadvertent "lookup" of anonymous types
2278 Symbol bestSoFar = typeNotFound;
2279 Symbol sym;
2280 boolean staticOnly = false;
2281 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
2282 if (isStatic(env1)) staticOnly = true;
2283 // First, look for a type variable and the first member type
2284 final Symbol tyvar = findTypeVar(env1, name, staticOnly);
2285 sym = findImmediateMemberType(env1, env1.enclClass.sym.type,
2286 name, env1.enclClass.sym);
2287
2288 // Return the type variable if we have it, and have no
2289 // immediate member, OR the type variable is for a method.
2290 if (tyvar != typeNotFound) {
2291 if (env.baseClause || sym == typeNotFound ||
2292 (tyvar.kind == TYP && tyvar.exists() &&
2293 tyvar.owner.kind == MTH)) {
2294 return tyvar;
2295 }
2296 }
2297
2298 // If the environment is a class def, finish up,
2299 // otherwise, do the entire findMemberType
2300 if (sym == typeNotFound)
2301 sym = findInheritedMemberType(env1, env1.enclClass.sym.type,
2302 name, env1.enclClass.sym);
2303
2304 if (staticOnly && sym.kind == TYP &&
2305 sym.type.hasTag(CLASS) &&
2306 sym.type.getEnclosingType().hasTag(CLASS) &&
2307 env1.enclClass.sym.type.isParameterized() &&
2308 sym.type.getEnclosingType().isParameterized())
2309 return new StaticError(sym);
2310 else if (sym.exists()) return sym;
2311 else bestSoFar = bestOf(bestSoFar, sym);
2312
2313 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
2314 if ((encl.sym.flags() & STATIC) != 0)
2315 staticOnly = true;
2316 }
2317
2318 if (!env.tree.hasTag(IMPORT)) {
2319 sym = findGlobalType(env, env.toplevel.namedImportScope, name, namedImportScopeRecovery);
2320 if (sym.exists()) return sym;
2321 else bestSoFar = bestOf(bestSoFar, sym);
2322
2323 sym = findGlobalType(env, env.toplevel.toplevelScope, name, noRecovery);
2324 if (sym.exists()) return sym;
2325 else bestSoFar = bestOf(bestSoFar, sym);
2326
2327 sym = findGlobalType(env, env.toplevel.packge.members(), name, noRecovery);
2328 if (sym.exists()) return sym;
2329 else bestSoFar = bestOf(bestSoFar, sym);
2330
2331 sym = findGlobalType(env, env.toplevel.starImportScope, name, starImportScopeRecovery);
2332 if (sym.exists()) return sym;
2333 else bestSoFar = bestOf(bestSoFar, sym);
2334 }
2335
2336 return bestSoFar;
2337 }
2338
2339 /** Find an unqualified identifier which matches a specified kind set.
2340 * @param pos position on which report warnings, if any;
2341 * null warnings should not be reported
2342 * @param env The current environment.
2343 * @param name The identifier's name.
2344 * @param kind Indicates the possible symbol kinds
2345 * (a subset of VAL, TYP, PCK).
2346 */
2347 Symbol findIdent(DiagnosticPosition pos, Env<AttrContext> env, Name name, KindSelector kind) {
2348 return checkRestrictedType(pos, findIdentInternal(env, name, kind), name);
2349 }
2350
2351 Symbol findIdentInternal(Env<AttrContext> env, Name name, KindSelector kind) {
2352 Symbol bestSoFar = typeNotFound;
2353 Symbol sym;
2354
2355 if (kind.contains(KindSelector.VAL)) {
2356 sym = findVar(env, name);
2357 if (sym.exists()) return sym;
2358 else bestSoFar = bestOf(bestSoFar, sym);
2359 }
2360
2361 if (kind.contains(KindSelector.TYP)) {
2362 sym = findType(env, name);
2363
2364 if (sym.exists()) return sym;
2365 else bestSoFar = bestOf(bestSoFar, sym);
2366 }
2367
2368 if (kind.contains(KindSelector.PCK))
2369 return lookupPackage(env, name);
2370 else return bestSoFar;
2371 }
2372
2373 /** Find an identifier in a package which matches a specified kind set.
2374 * @param pos position on which report warnings, if any;
2375 * null warnings should not be reported
2376 * @param env The current environment.
2377 * @param name The identifier's name.
2378 * @param kind Indicates the possible symbol kinds
2379 * (a nonempty subset of TYP, PCK).
2380 */
2381 Symbol findIdentInPackage(DiagnosticPosition pos,
2382 Env<AttrContext> env, TypeSymbol pck,
2383 Name name, KindSelector kind) {
2384 return checkRestrictedType(pos, findIdentInPackageInternal(env, pck, name, kind), name);
2385 }
2386
2387 Symbol findIdentInPackageInternal(Env<AttrContext> env, TypeSymbol pck,
2388 Name name, KindSelector kind) {
2389 Name fullname = TypeSymbol.formFullName(name, pck);
2390 Symbol bestSoFar = typeNotFound;
2391 if (kind.contains(KindSelector.TYP)) {
2392 RecoveryLoadClass recoveryLoadClass =
2393 allowModules && !kind.contains(KindSelector.PCK) &&
2394 !pck.exists() && !env.info.attributionMode.isSpeculative ?
2395 doRecoveryLoadClass : noRecovery;
2396 Symbol sym = loadClass(env, fullname, recoveryLoadClass);
2397 if (sym.exists()) {
2398 // don't allow programs to use flatnames
2399 if (name == sym.name) return sym;
2400 }
2401 else bestSoFar = bestOf(bestSoFar, sym);
2402 }
2403 if (kind.contains(KindSelector.PCK)) {
2404 return lookupPackage(env, fullname);
2405 }
2406 return bestSoFar;
2407 }
2408
2409 /** Find an identifier among the members of a given type `site'.
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 site The type containing the symbol to be found.
2414 * @param name The identifier's name.
2415 * @param kind Indicates the possible symbol kinds
2416 * (a subset of VAL, TYP).
2417 */
2418 Symbol findIdentInType(DiagnosticPosition pos,
2419 Env<AttrContext> env, Type site,
2420 Name name, KindSelector kind) {
2421 return checkRestrictedType(pos, findIdentInTypeInternal(env, site, name, kind), name);
2422 }
2423
2424 Symbol findIdentInTypeInternal(Env<AttrContext> env, Type site,
2425 Name name, KindSelector kind) {
2426 Symbol bestSoFar = typeNotFound;
2427 Symbol sym;
2428 if (kind.contains(KindSelector.VAL)) {
2429 sym = findField(env, site, name, site.tsym);
2430 if (sym.exists()) return sym;
2431 else bestSoFar = bestOf(bestSoFar, sym);
2432 }
2433
2434 if (kind.contains(KindSelector.TYP)) {
2435 sym = findMemberType(env, site, name, site.tsym);
2436 if (sym.exists()) return sym;
2437 else bestSoFar = bestOf(bestSoFar, sym);
2438 }
2439 return bestSoFar;
2440 }
2441
2442 private Symbol checkRestrictedType(DiagnosticPosition pos, Symbol bestSoFar, Name name) {
2443 if (bestSoFar.kind == TYP || bestSoFar.kind == ABSENT_TYP) {
2444 if (allowLocalVariableTypeInference && name.equals(names.var)) {
2445 bestSoFar = new BadRestrictedTypeError(names.var);
2446 } else if (name.equals(names.yield)) {
2447 if (allowYieldStatement) {
2448 bestSoFar = new BadRestrictedTypeError(names.yield);
2449 } else if (pos != null) {
2450 log.warning(pos, Warnings.IllegalRefToRestrictedType(names.yield));
2451 }
2452 }
2453 }
2454 return bestSoFar;
2455 }
2456
2457 /* ***************************************************************************
2458 * Access checking
2459 * The following methods convert ResolveErrors to ErrorSymbols, issuing
2460 * an error message in the process
2461 ****************************************************************************/
2462
2463 /** If `sym' is a bad symbol: report error and return errSymbol
2464 * else pass through unchanged,
2465 * additional arguments duplicate what has been used in trying to find the
2466 * symbol {@literal (--> flyweight pattern)}. This improves performance since we
2467 * expect misses to happen frequently.
2468 *
2469 * @param sym The symbol that was found, or a ResolveError.
2470 * @param pos The position to use for error reporting.
2471 * @param location The symbol the served as a context for this lookup
2472 * @param site The original type from where the selection took place.
2473 * @param name The symbol's name.
2474 * @param qualified Did we get here through a qualified expression resolution?
2475 * @param argtypes The invocation's value arguments,
2476 * if we looked for a method.
2477 * @param typeargtypes The invocation's type arguments,
2478 * if we looked for a method.
2479 * @param logResolveHelper helper class used to log resolve errors
2480 */
2481 Symbol accessInternal(Symbol sym,
2482 DiagnosticPosition pos,
2483 Symbol location,
2484 Type site,
2485 Name name,
2486 boolean qualified,
2487 List<Type> argtypes,
2488 List<Type> typeargtypes,
2489 LogResolveHelper logResolveHelper) {
2490 if (sym.kind.isResolutionError()) {
2491 ResolveError errSym = (ResolveError)sym.baseSymbol();
2492 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
2493 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes);
2494 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) {
2495 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
2496 }
2497 }
2498 return sym;
2499 }
2500
2501 /**
2502 * Variant of the generalized access routine, to be used for generating method
2503 * resolution diagnostics
2504 */
2505 Symbol accessMethod(Symbol sym,
2506 DiagnosticPosition pos,
2507 Symbol location,
2508 Type site,
2509 Name name,
2510 boolean qualified,
2511 List<Type> argtypes,
2512 List<Type> typeargtypes) {
2513 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper);
2514 }
2515
2516 /** Same as original accessMethod(), but without location.
2517 */
2518 Symbol accessMethod(Symbol sym,
2519 DiagnosticPosition pos,
2520 Type site,
2521 Name name,
2522 boolean qualified,
2523 List<Type> argtypes,
2524 List<Type> typeargtypes) {
2525 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
2526 }
2527
2528 /**
2529 * Variant of the generalized access routine, to be used for generating variable,
2530 * type resolution diagnostics
2531 */
2532 Symbol accessBase(Symbol sym,
2533 DiagnosticPosition pos,
2534 Symbol location,
2535 Type site,
2536 Name name,
2537 boolean qualified) {
2538 return accessInternal(sym, pos, location, site, name, qualified, List.nil(), null, basicLogResolveHelper);
2539 }
2540
2541 /** Same as original accessBase(), but without location.
2542 */
2543 Symbol accessBase(Symbol sym,
2544 DiagnosticPosition pos,
2545 Type site,
2546 Name name,
2547 boolean qualified) {
2548 return accessBase(sym, pos, site.tsym, site, name, qualified);
2549 }
2550
2551 interface LogResolveHelper {
2552 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes);
2553 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes);
2554 }
2555
2556 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() {
2557 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2558 return !site.isErroneous();
2559 }
2560 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2561 return argtypes;
2562 }
2563 };
2564
2565 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() {
2566 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2567 return !site.isErroneous() &&
2568 !Type.isErroneous(argtypes) &&
2569 (typeargtypes == null || !Type.isErroneous(typeargtypes));
2570 }
2571 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2572 return argtypes.map(new ResolveDeferredRecoveryMap(AttrMode.SPECULATIVE, accessedSym, currentResolutionContext.step));
2573 }
2574 };
2575
2576 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap {
2577
2578 public ResolveDeferredRecoveryMap(AttrMode mode, Symbol msym, MethodResolutionPhase step) {
2579 deferredAttr.super(mode, msym, step);
2580 }
2581
2582 @Override
2583 protected Type typeOf(DeferredType dt, Type pt) {
2584 Type res = super.typeOf(dt, pt);
2585 if (!res.isErroneous()) {
2586 switch (TreeInfo.skipParens(dt.tree).getTag()) {
2587 case LAMBDA:
2588 case REFERENCE:
2589 return dt;
2590 case CONDEXPR:
2591 return res == Type.recoveryType ?
2592 dt : res;
2593 }
2594 }
2595 return res;
2596 }
2597 }
2598
2599 /** Check that sym is not an abstract method.
2600 */
2601 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
2602 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0)
2603 log.error(pos,
2604 Errors.AbstractCantBeAccessedDirectly(kindName(sym),sym, sym.location()));
2605 }
2606
2607 /* ***************************************************************************
2608 * Name resolution
2609 * Naming conventions are as for symbol lookup
2610 * Unlike the find... methods these methods will report access errors
2611 ****************************************************************************/
2612
2613 /** Resolve an unqualified (non-method) identifier.
2614 * @param pos The position to use for error reporting.
2615 * @param env The environment current at the identifier use.
2616 * @param name The identifier's name.
2617 * @param kind The set of admissible symbol kinds for the identifier.
2618 */
2619 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
2620 Name name, KindSelector kind) {
2621 return accessBase(
2622 findIdent(pos, env, name, kind),
2623 pos, env.enclClass.sym.type, name, false);
2624 }
2625
2626 /** Resolve an unqualified method identifier.
2627 * @param pos The position to use for error reporting.
2628 * @param env The environment current at the method invocation.
2629 * @param name The identifier's name.
2630 * @param argtypes The types of the invocation's value arguments.
2631 * @param typeargtypes The types of the invocation's type arguments.
2632 */
2633 Symbol resolveMethod(DiagnosticPosition pos,
2634 Env<AttrContext> env,
2635 Name name,
2636 List<Type> argtypes,
2637 List<Type> typeargtypes) {
2638 return lookupMethod(env, pos, env.enclClass.sym, resolveMethodCheck,
2639 new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) {
2640 @Override
2641 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2642 return findFun(env, name, argtypes, typeargtypes,
2643 phase.isBoxingRequired(),
2644 phase.isVarargsRequired());
2645 }});
2646 }
2647
2648 /** Resolve a qualified method identifier
2649 * @param pos The position to use for error reporting.
2650 * @param env The environment current at the method invocation.
2651 * @param site The type of the qualifying expression, in which
2652 * identifier is searched.
2653 * @param name The identifier's name.
2654 * @param argtypes The types of the invocation's value arguments.
2655 * @param typeargtypes The types of the invocation's type arguments.
2656 */
2657 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2658 Type site, Name name, List<Type> argtypes,
2659 List<Type> typeargtypes) {
2660 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
2661 }
2662 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2663 Symbol location, Type site, Name name, List<Type> argtypes,
2664 List<Type> typeargtypes) {
2665 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
2666 }
2667 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
2668 DiagnosticPosition pos, Env<AttrContext> env,
2669 Symbol location, Type site, Name name, List<Type> argtypes,
2670 List<Type> typeargtypes) {
2671 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) {
2672 @Override
2673 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2674 return findMethod(env, site, name, argtypes, typeargtypes,
2675 phase.isBoxingRequired(),
2676 phase.isVarargsRequired());
2677 }
2678 @Override
2679 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2680 if (sym.kind.isResolutionError()) {
2681 sym = super.access(env, pos, location, sym);
2682 } else {
2683 MethodSymbol msym = (MethodSymbol)sym;
2684 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) {
2685 env.info.pendingResolutionPhase = BASIC;
2686 return findPolymorphicSignatureInstance(env, sym, argtypes);
2687 }
2688 }
2689 return sym;
2690 }
2691 });
2692 }
2693
2694 /** Find or create an implicit method of exactly the given type (after erasure).
2695 * Searches in a side table, not the main scope of the site.
2696 * This emulates the lookup process required by JSR 292 in JVM.
2697 * @param env Attribution environment
2698 * @param spMethod signature polymorphic method - i.e. MH.invokeExact
2699 * @param argtypes The required argument types
2700 */
2701 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env,
2702 final Symbol spMethod,
2703 List<Type> argtypes) {
2704 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
2705 (MethodSymbol)spMethod, currentResolutionContext, argtypes);
2706 return findPolymorphicSignatureInstance(spMethod, mtype);
2707 }
2708
2709 Symbol findPolymorphicSignatureInstance(final Symbol spMethod,
2710 Type mtype) {
2711 for (Symbol sym : polymorphicSignatureScope.getSymbolsByName(spMethod.name)) {
2712 // Check that there is already a method symbol for the method
2713 // type and owner
2714 if (types.isSameType(mtype, sym.type) &&
2715 spMethod.owner == sym.owner) {
2716 return sym;
2717 }
2718 }
2719
2720 // Create the desired method
2721 // Retain static modifier is to support invocations to
2722 // MethodHandle.linkTo* methods
2723 long flags = ABSTRACT | HYPOTHETICAL |
2724 spMethod.flags() & (Flags.AccessFlags | Flags.STATIC);
2725 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) {
2726 @Override
2727 public Symbol baseSymbol() {
2728 return spMethod;
2729 }
2730 };
2731 if (!mtype.isErroneous()) { // Cache only if kosher.
2732 polymorphicSignatureScope.enter(msym);
2733 }
2734 return msym;
2735 }
2736
2737 /** Resolve a qualified method identifier, throw a fatal error if not
2738 * found.
2739 * @param pos The position to use for error reporting.
2740 * @param env The environment current at the method invocation.
2741 * @param site The type of the qualifying expression, in which
2742 * identifier is searched.
2743 * @param name The identifier's name.
2744 * @param argtypes The types of the invocation's value arguments.
2745 * @param typeargtypes The types of the invocation's type arguments.
2746 */
2747 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
2748 Type site, Name name,
2749 List<Type> argtypes,
2750 List<Type> typeargtypes) {
2751 MethodResolutionContext resolveContext = new MethodResolutionContext();
2752 resolveContext.internalResolution = true;
2753 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
2754 site, name, argtypes, typeargtypes);
2755 if (sym.kind == MTH) return (MethodSymbol)sym;
2756 else throw new FatalError(
2757 diags.fragment(Fragments.FatalErrCantLocateMeth(name)));
2758 }
2759
2760 /** Resolve constructor.
2761 * @param pos The position to use for error reporting.
2762 * @param env The environment current at the constructor invocation.
2763 * @param site The type of class for which a constructor is searched.
2764 * @param argtypes The types of the constructor invocation's value
2765 * arguments.
2766 * @param typeargtypes The types of the constructor invocation's type
2767 * arguments.
2768 */
2769 Symbol resolveConstructor(DiagnosticPosition pos,
2770 Env<AttrContext> env,
2771 Type site,
2772 List<Type> argtypes,
2773 List<Type> typeargtypes) {
2774 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
2775 }
2776
2777 private Symbol resolveConstructor(MethodResolutionContext resolveContext,
2778 final DiagnosticPosition pos,
2779 Env<AttrContext> env,
2780 Type site,
2781 List<Type> argtypes,
2782 List<Type> typeargtypes) {
2783 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2784 @Override
2785 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2786 return findConstructor(pos, env, site, argtypes, typeargtypes,
2787 phase.isBoxingRequired(),
2788 phase.isVarargsRequired());
2789 }
2790 });
2791 }
2792
2793 /** Resolve a constructor, throw a fatal error if not found.
2794 * @param pos The position to use for error reporting.
2795 * @param env The environment current at the method invocation.
2796 * @param site The type to be constructed.
2797 * @param argtypes The types of the invocation's value arguments.
2798 * @param typeargtypes The types of the invocation's type arguments.
2799 */
2800 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2801 Type site,
2802 List<Type> argtypes,
2803 List<Type> typeargtypes) {
2804 MethodResolutionContext resolveContext = new MethodResolutionContext();
2805 resolveContext.internalResolution = true;
2806 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
2807 if (sym.kind == MTH) return (MethodSymbol)sym;
2808 else throw new FatalError(
2809 diags.fragment(Fragments.FatalErrCantLocateCtor(site)));
2810 }
2811
2812 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2813 Type site, List<Type> argtypes,
2814 List<Type> typeargtypes,
2815 boolean allowBoxing,
2816 boolean useVarargs) {
2817 Symbol sym = findMethod(env, site,
2818 names.init, argtypes,
2819 typeargtypes, allowBoxing,
2820 useVarargs);
2821 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2822 chk.checkPreview(pos, sym);
2823 return sym;
2824 }
2825
2826 /** Resolve constructor using diamond inference.
2827 * @param pos The position to use for error reporting.
2828 * @param env The environment current at the constructor invocation.
2829 * @param site The type of class for which a constructor is searched.
2830 * The scope of this class has been touched in attribution.
2831 * @param argtypes The types of the constructor invocation's value
2832 * arguments.
2833 * @param typeargtypes The types of the constructor invocation's type
2834 * arguments.
2835 */
2836 Symbol resolveDiamond(DiagnosticPosition pos,
2837 Env<AttrContext> env,
2838 Type site,
2839 List<Type> argtypes,
2840 List<Type> typeargtypes) {
2841 return lookupMethod(env, pos, site.tsym, resolveMethodCheck,
2842 new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2843 @Override
2844 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2845 return findDiamond(env, site, argtypes, typeargtypes,
2846 phase.isBoxingRequired(),
2847 phase.isVarargsRequired());
2848 }
2849 @Override
2850 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2851 if (sym.kind.isResolutionError()) {
2852 if (sym.kind != WRONG_MTH &&
2853 sym.kind != WRONG_MTHS) {
2854 sym = super.access(env, pos, location, sym);
2855 } else {
2856 final JCDiagnostic details = sym.kind == WRONG_MTH ?
2857 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd :
2858 null;
2859 sym = new DiamondError(sym, currentResolutionContext);
2860 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes);
2861 env.info.pendingResolutionPhase = currentResolutionContext.step;
2862 }
2863 }
2864 return sym;
2865 }});
2866 }
2867
2868 /** This method scans all the constructor symbol in a given class scope -
2869 * assuming that the original scope contains a constructor of the kind:
2870 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
2871 * a method check is executed against the modified constructor type:
2872 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond
2873 * inference. The inferred return type of the synthetic constructor IS
2874 * the inferred type for the diamond operator.
2875 */
2876 private Symbol findDiamond(Env<AttrContext> env,
2877 Type site,
2878 List<Type> argtypes,
2879 List<Type> typeargtypes,
2880 boolean allowBoxing,
2881 boolean useVarargs) {
2882 Symbol bestSoFar = methodNotFound;
2883 TypeSymbol tsym = site.tsym.isInterface() ? syms.objectType.tsym : site.tsym;
2884 for (final Symbol sym : tsym.members().getSymbolsByName(names.init)) {
2885 //- System.out.println(" e " + e.sym);
2886 if (sym.kind == MTH &&
2887 (sym.flags_field & SYNTHETIC) == 0) {
2888 List<Type> oldParams = sym.type.hasTag(FORALL) ?
2889 ((ForAll)sym.type).tvars :
2890 List.nil();
2891 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
2892 types.createMethodTypeWithReturn(sym.type.asMethodType(), site));
2893 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) {
2894 @Override
2895 public Symbol baseSymbol() {
2896 return sym;
2897 }
2898 };
2899 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
2900 newConstr,
2901 bestSoFar,
2902 allowBoxing,
2903 useVarargs);
2904 }
2905 }
2906 return bestSoFar;
2907 }
2908
2909 Symbol getMemberReference(DiagnosticPosition pos,
2910 Env<AttrContext> env,
2911 JCMemberReference referenceTree,
2912 Type site,
2913 Name name) {
2914
2915 site = types.capture(site);
2916
2917 ReferenceLookupHelper lookupHelper = makeReferenceLookupHelper(
2918 referenceTree, site, name, List.nil(), null, VARARITY);
2919
2920 Env<AttrContext> newEnv = env.dup(env.tree, env.info.dup());
2921 Symbol sym = lookupMethod(newEnv, env.tree.pos(), site.tsym,
2922 nilMethodCheck, lookupHelper);
2923
2924 env.info.pendingResolutionPhase = newEnv.info.pendingResolutionPhase;
2925
2926 return sym;
2927 }
2928
2929 ReferenceLookupHelper makeReferenceLookupHelper(JCMemberReference referenceTree,
2930 Type site,
2931 Name name,
2932 List<Type> argtypes,
2933 List<Type> typeargtypes,
2934 MethodResolutionPhase maxPhase) {
2935 if (!name.equals(names.init)) {
2936 //method reference
2937 return new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2938 } else if (site.hasTag(ARRAY)) {
2939 //array constructor reference
2940 return new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2941 } else {
2942 //class constructor reference
2943 return new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2944 }
2945 }
2946
2947 /**
2948 * Resolution of member references is typically done as a single
2949 * overload resolution step, where the argument types A are inferred from
2950 * the target functional descriptor.
2951 *
2952 * If the member reference is a method reference with a type qualifier,
2953 * a two-step lookup process is performed. The first step uses the
2954 * expected argument list A, while the second step discards the first
2955 * type from A (which is treated as a receiver type).
2956 *
2957 * There are two cases in which inference is performed: (i) if the member
2958 * reference is a constructor reference and the qualifier type is raw - in
2959 * which case diamond inference is used to infer a parameterization for the
2960 * type qualifier; (ii) if the member reference is an unbound reference
2961 * where the type qualifier is raw - in that case, during the unbound lookup
2962 * the receiver argument type is used to infer an instantiation for the raw
2963 * qualifier type.
2964 *
2965 * When a multi-step resolution process is exploited, the process of picking
2966 * the resulting symbol is delegated to an helper class {@link com.sun.tools.javac.comp.Resolve.ReferenceChooser}.
2967 *
2968 * This routine returns a pair (T,S), where S is the member reference symbol,
2969 * and T is the type of the class in which S is defined. This is necessary as
2970 * the type T might be dynamically inferred (i.e. if constructor reference
2971 * has a raw qualifier).
2972 */
2973 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(Env<AttrContext> env,
2974 JCMemberReference referenceTree,
2975 Type site,
2976 Name name,
2977 List<Type> argtypes,
2978 List<Type> typeargtypes,
2979 Type descriptor,
2980 MethodCheck methodCheck,
2981 InferenceContext inferenceContext,
2982 ReferenceChooser referenceChooser) {
2983
2984 //step 1 - bound lookup
2985 ReferenceLookupHelper boundLookupHelper = makeReferenceLookupHelper(
2986 referenceTree, site, name, argtypes, typeargtypes, VARARITY);
2987 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup());
2988 MethodResolutionContext boundSearchResolveContext = new MethodResolutionContext();
2989 boundSearchResolveContext.methodCheck = methodCheck;
2990 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(),
2991 site.tsym, boundSearchResolveContext, boundLookupHelper);
2992 ReferenceLookupResult boundRes = new ReferenceLookupResult(boundSym, boundSearchResolveContext);
2993
2994 //step 2 - unbound lookup
2995 Symbol unboundSym = methodNotFound;
2996 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup());
2997 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup(inferenceContext);
2998 ReferenceLookupResult unboundRes = referenceNotFound;
2999 if (unboundLookupHelper != null) {
3000 MethodResolutionContext unboundSearchResolveContext =
3001 new MethodResolutionContext();
3002 unboundSearchResolveContext.methodCheck = methodCheck;
3003 unboundSym = lookupMethod(unboundEnv, env.tree.pos(),
3004 site.tsym, unboundSearchResolveContext, unboundLookupHelper);
3005 unboundRes = new ReferenceLookupResult(unboundSym, unboundSearchResolveContext);
3006 }
3007
3008 //merge results
3009 Pair<Symbol, ReferenceLookupHelper> res;
3010 ReferenceLookupResult bestRes = referenceChooser.result(boundRes, unboundRes);
3011 res = new Pair<>(bestRes.sym,
3012 bestRes == unboundRes ? unboundLookupHelper : boundLookupHelper);
3013 env.info.pendingResolutionPhase = bestRes == unboundRes ?
3014 unboundEnv.info.pendingResolutionPhase :
3015 boundEnv.info.pendingResolutionPhase;
3016
3017 if (!res.fst.kind.isResolutionError()) {
3018 //handle sigpoly method references
3019 MethodSymbol msym = (MethodSymbol)res.fst;
3020 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) {
3021 env.info.pendingResolutionPhase = BASIC;
3022 res = new Pair<>(findPolymorphicSignatureInstance(msym, descriptor), res.snd);
3023 }
3024 }
3025
3026 return res;
3027 }
3028
3029 /**
3030 * This class is used to represent a method reference lookup result. It keeps track of two
3031 * things: (i) the symbol found during a method reference lookup and (ii) the static kind
3032 * of the lookup (see {@link com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind}).
3033 */
3034 static class ReferenceLookupResult {
3035
3036 /**
3037 * Static kind associated with a method reference lookup. Erroneous lookups end up with
3038 * the UNDEFINED kind; successful lookups will end up with either STATIC, NON_STATIC,
3039 * depending on whether all applicable candidates are static or non-static methods,
3040 * respectively. If a successful lookup has both static and non-static applicable methods,
3041 * its kind is set to BOTH.
3042 */
3043 enum StaticKind {
3044 STATIC,
3045 NON_STATIC,
3046 BOTH,
3047 UNDEFINED;
3048
3049 /**
3050 * Retrieve the static kind associated with a given (method) symbol.
3051 */
3052 static StaticKind from(Symbol s) {
3053 return s.isStatic() ?
3054 STATIC : NON_STATIC;
3055 }
3056
3057 /**
3058 * Merge two static kinds together.
3059 */
3060 static StaticKind reduce(StaticKind sk1, StaticKind sk2) {
3061 if (sk1 == UNDEFINED) {
3062 return sk2;
3063 } else if (sk2 == UNDEFINED) {
3064 return sk1;
3065 } else {
3066 return sk1 == sk2 ? sk1 : BOTH;
3067 }
3068 }
3069 }
3070
3071 /** The static kind. */
3072 StaticKind staticKind;
3073
3074 /** The lookup result. */
3075 Symbol sym;
3076
3077 ReferenceLookupResult(Symbol sym, MethodResolutionContext resolutionContext) {
3078 this(sym, staticKind(sym, resolutionContext));
3079 }
3080
3081 private ReferenceLookupResult(Symbol sym, StaticKind staticKind) {
3082 this.staticKind = staticKind;
3083 this.sym = sym;
3084 }
3085
3086 private static StaticKind staticKind(Symbol sym, MethodResolutionContext resolutionContext) {
3087 switch (sym.kind) {
3088 case MTH:
3089 case AMBIGUOUS:
3090 return resolutionContext.candidates.stream()
3091 .filter(c -> c.isApplicable() && c.step == resolutionContext.step)
3092 .map(c -> StaticKind.from(c.sym))
3093 .reduce(StaticKind::reduce)
3094 .orElse(StaticKind.UNDEFINED);
3095 default:
3096 return StaticKind.UNDEFINED;
3097 }
3098 }
3099
3100 /**
3101 * Does this result corresponds to a successful lookup (i.e. one where a method has been found?)
3102 */
3103 boolean isSuccess() {
3104 return staticKind != StaticKind.UNDEFINED;
3105 }
3106
3107 /**
3108 * Does this result have given static kind?
3109 */
3110 boolean hasKind(StaticKind sk) {
3111 return this.staticKind == sk;
3112 }
3113
3114 /**
3115 * Error recovery helper: can this lookup result be ignored (for the purpose of returning
3116 * some 'better' result) ?
3117 */
3118 boolean canIgnore() {
3119 switch (sym.kind) {
3120 case ABSENT_MTH:
3121 return true;
3122 case WRONG_MTH:
3123 InapplicableSymbolError errSym =
3124 (InapplicableSymbolError)sym.baseSymbol();
3125 return new Template(MethodCheckDiag.ARITY_MISMATCH.regex())
3126 .matches(errSym.errCandidate().snd);
3127 case WRONG_MTHS:
3128 InapplicableSymbolsError errSyms =
3129 (InapplicableSymbolsError)sym.baseSymbol();
3130 return errSyms.filterCandidates(errSyms.mapCandidates()).isEmpty();
3131 default:
3132 return false;
3133 }
3134 }
3135
3136 static ReferenceLookupResult error(Symbol sym) {
3137 return new ReferenceLookupResult(sym, StaticKind.UNDEFINED);
3138 }
3139 }
3140
3141 /**
3142 * This abstract class embodies the logic that converts one (bound lookup) or two (unbound lookup)
3143 * {@code ReferenceLookupResult} objects into a (@code Symbol), which is then regarded as the
3144 * result of method reference resolution.
3145 */
3146 abstract class ReferenceChooser {
3147 /**
3148 * Generate a result from a pair of lookup result objects. This method delegates to the
3149 * appropriate result generation routine.
3150 */
3151 ReferenceLookupResult result(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3152 return unboundRes != referenceNotFound ?
3153 unboundResult(boundRes, unboundRes) :
3154 boundResult(boundRes);
3155 }
3156
3157 /**
3158 * Generate a symbol from a given bound lookup result.
3159 */
3160 abstract ReferenceLookupResult boundResult(ReferenceLookupResult boundRes);
3161
3162 /**
3163 * Generate a symbol from a pair of bound/unbound lookup results.
3164 */
3165 abstract ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes);
3166 }
3167
3168 /**
3169 * This chooser implements the selection strategy used during a full lookup; this logic
3170 * is described in JLS SE 8 (15.3.2).
3171 */
3172 ReferenceChooser basicReferenceChooser = new ReferenceChooser() {
3173
3174 @Override
3175 ReferenceLookupResult boundResult(ReferenceLookupResult boundRes) {
3176 return !boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC) ?
3177 boundRes : //the search produces a non-static method
3178 ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.sym, false));
3179 }
3180
3181 @Override
3182 ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3183 if (boundRes.hasKind(StaticKind.STATIC) &&
3184 (!unboundRes.isSuccess() || unboundRes.hasKind(StaticKind.STATIC))) {
3185 //the first search produces a static method and no non-static method is applicable
3186 //during the second search
3187 return boundRes;
3188 } else if (unboundRes.hasKind(StaticKind.NON_STATIC) &&
3189 (!boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC))) {
3190 //the second search produces a non-static method and no static method is applicable
3191 //during the first search
3192 return unboundRes;
3193 } else if (boundRes.isSuccess() && unboundRes.isSuccess()) {
3194 //both searches produce some result; ambiguity (error recovery)
3195 return ReferenceLookupResult.error(ambiguityError(boundRes.sym, unboundRes.sym));
3196 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) {
3197 //Both searches failed to produce a result with correct staticness (i.e. first search
3198 //produces an non-static method). Alternatively, a given search produced a result
3199 //with the right staticness, but the other search has applicable methods with wrong
3200 //staticness (error recovery)
3201 return ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.isSuccess() ?
3202 boundRes.sym : unboundRes.sym, true));
3203 } else {
3204 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery)
3205 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ?
3206 unboundRes : boundRes;
3207 }
3208 }
3209 };
3210
3211 /**
3212 * This chooser implements the selection strategy used during an arity-based lookup; this logic
3213 * is described in JLS SE 8 (15.12.2.1).
3214 */
3215 ReferenceChooser structuralReferenceChooser = new ReferenceChooser() {
3216
3217 @Override
3218 ReferenceLookupResult boundResult(ReferenceLookupResult boundRes) {
3219 return (!boundRes.isSuccess() || !boundRes.hasKind(StaticKind.STATIC)) ?
3220 boundRes : //the search has at least one applicable non-static method
3221 ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.sym, false));
3222 }
3223
3224 @Override
3225 ReferenceLookupResult unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
3226 if (boundRes.isSuccess() && !boundRes.hasKind(StaticKind.NON_STATIC)) {
3227 //the first search has at least one applicable static method
3228 return boundRes;
3229 } else if (unboundRes.isSuccess() && !unboundRes.hasKind(StaticKind.STATIC)) {
3230 //the second search has at least one applicable non-static method
3231 return unboundRes;
3232 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) {
3233 //either the first search produces a non-static method, or second search produces
3234 //a non-static method (error recovery)
3235 return ReferenceLookupResult.error(new BadMethodReferenceError(boundRes.isSuccess() ?
3236 boundRes.sym : unboundRes.sym, true));
3237 } else {
3238 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery)
3239 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ?
3240 unboundRes : boundRes;
3241 }
3242 }
3243 };
3244
3245 /**
3246 * Helper for defining custom method-like lookup logic; a lookup helper
3247 * provides hooks for (i) the actual lookup logic and (ii) accessing the
3248 * lookup result (this step might result in compiler diagnostics to be generated)
3249 */
3250 abstract class LookupHelper {
3251
3252 /** name of the symbol to lookup */
3253 Name name;
3254
3255 /** location in which the lookup takes place */
3256 Type site;
3257
3258 /** actual types used during the lookup */
3259 List<Type> argtypes;
3260
3261 /** type arguments used during the lookup */
3262 List<Type> typeargtypes;
3263
3264 /** Max overload resolution phase handled by this helper */
3265 MethodResolutionPhase maxPhase;
3266
3267 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3268 this.name = name;
3269 this.site = site;
3270 this.argtypes = argtypes;
3271 this.typeargtypes = typeargtypes;
3272 this.maxPhase = maxPhase;
3273 }
3274
3275 /**
3276 * Should lookup stop at given phase with given result
3277 */
3278 final boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
3279 return phase.ordinal() > maxPhase.ordinal() ||
3280 !sym.kind.isResolutionError() || sym.kind == AMBIGUOUS;
3281 }
3282
3283 /**
3284 * Search for a symbol under a given overload resolution phase - this method
3285 * is usually called several times, once per each overload resolution phase
3286 */
3287 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase);
3288
3289 /**
3290 * Dump overload resolution info
3291 */
3292 void debug(DiagnosticPosition pos, Symbol sym) {
3293 //do nothing
3294 }
3295
3296 /**
3297 * Validate the result of the lookup
3298 */
3299 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym);
3300 }
3301
3302 abstract class BasicLookupHelper extends LookupHelper {
3303
3304 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) {
3305 this(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY);
3306 }
3307
3308 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3309 super(name, site, argtypes, typeargtypes, maxPhase);
3310 }
3311
3312 @Override
3313 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3314 Symbol sym = doLookup(env, phase);
3315 if (sym.kind == AMBIGUOUS) {
3316 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
3317 sym = a_err.mergeAbstracts(site);
3318 }
3319 return sym;
3320 }
3321
3322 abstract Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase);
3323
3324 @Override
3325 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
3326 if (sym.kind.isResolutionError()) {
3327 //if nothing is found return the 'first' error
3328 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes);
3329 }
3330 return sym;
3331 }
3332
3333 @Override
3334 void debug(DiagnosticPosition pos, Symbol sym) {
3335 reportVerboseResolutionDiagnostic(pos, name, site, argtypes, typeargtypes, sym);
3336 }
3337 }
3338
3339 /**
3340 * Helper class for member reference lookup. A reference lookup helper
3341 * defines the basic logic for member reference lookup; a method gives
3342 * access to an 'unbound' helper used to perform an unbound member
3343 * reference lookup.
3344 */
3345 abstract class ReferenceLookupHelper extends LookupHelper {
3346
3347 /** The member reference tree */
3348 JCMemberReference referenceTree;
3349
3350 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3351 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3352 super(name, site, argtypes, typeargtypes, maxPhase);
3353 this.referenceTree = referenceTree;
3354 }
3355
3356 /**
3357 * Returns an unbound version of this lookup helper. By default, this
3358 * method returns an dummy lookup helper.
3359 */
3360 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3361 return null;
3362 }
3363
3364 /**
3365 * Get the kind of the member reference
3366 */
3367 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym);
3368
3369 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
3370 if (sym.kind == AMBIGUOUS) {
3371 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
3372 sym = a_err.mergeAbstracts(site);
3373 }
3374 //skip error reporting
3375 return sym;
3376 }
3377 }
3378
3379 /**
3380 * Helper class for method reference lookup. The lookup logic is based
3381 * upon Resolve.findMethod; in certain cases, this helper class has a
3382 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper).
3383 * In such cases, non-static lookup results are thrown away.
3384 */
3385 class MethodReferenceLookupHelper extends ReferenceLookupHelper {
3386
3387 /** The original method reference lookup site. */
3388 Type originalSite;
3389
3390 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3391 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3392 super(referenceTree, name, types.skipTypeVars(site, true), argtypes, typeargtypes, maxPhase);
3393 this.originalSite = site;
3394 }
3395
3396 @Override
3397 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3398 return findMethod(env, site, name, argtypes, typeargtypes,
3399 phase.isBoxingRequired(), phase.isVarargsRequired());
3400 }
3401
3402 @Override
3403 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3404 if (TreeInfo.isStaticSelector(referenceTree.expr, names)) {
3405 if (argtypes.nonEmpty() &&
3406 (argtypes.head.hasTag(NONE) ||
3407 types.isSubtypeUnchecked(inferenceContext.asUndetVar(argtypes.head), originalSite))) {
3408 return new UnboundMethodReferenceLookupHelper(referenceTree, name,
3409 originalSite, argtypes, typeargtypes, maxPhase);
3410 } else {
3411 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) {
3412 @Override
3413 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3414 return this;
3415 }
3416
3417 @Override
3418 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3419 return methodNotFound;
3420 }
3421
3422 @Override
3423 ReferenceKind referenceKind(Symbol sym) {
3424 Assert.error();
3425 return null;
3426 }
3427 };
3428 }
3429 } else {
3430 return super.unboundLookup(inferenceContext);
3431 }
3432 }
3433
3434 @Override
3435 ReferenceKind referenceKind(Symbol sym) {
3436 if (sym.isStatic()) {
3437 return ReferenceKind.STATIC;
3438 } else {
3439 Name selName = TreeInfo.name(referenceTree.getQualifierExpression());
3440 return selName != null && selName == names._super ?
3441 ReferenceKind.SUPER :
3442 ReferenceKind.BOUND;
3443 }
3444 }
3445 }
3446
3447 /**
3448 * Helper class for unbound method reference lookup. Essentially the same
3449 * as the basic method reference lookup helper; main difference is that static
3450 * lookup results are thrown away. If qualifier type is raw, an attempt to
3451 * infer a parameterized type is made using the first actual argument (that
3452 * would otherwise be ignored during the lookup).
3453 */
3454 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper {
3455
3456 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3457 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3458 super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase);
3459 if (site.isRaw() && !argtypes.head.hasTag(NONE)) {
3460 Type asSuperSite = types.asSuper(argtypes.head, site.tsym);
3461 this.site = types.skipTypeVars(asSuperSite, true);
3462 }
3463 }
3464
3465 @Override
3466 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3467 return this;
3468 }
3469
3470 @Override
3471 ReferenceKind referenceKind(Symbol sym) {
3472 return ReferenceKind.UNBOUND;
3473 }
3474 }
3475
3476 /**
3477 * Helper class for array constructor lookup; an array constructor lookup
3478 * is simulated by looking up a method that returns the array type specified
3479 * as qualifier, and that accepts a single int parameter (size of the array).
3480 */
3481 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper {
3482
3483 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
3484 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3485 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
3486 }
3487
3488 @Override
3489 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3490 WriteableScope sc = WriteableScope.create(syms.arrayClass);
3491 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym);
3492 arrayConstr.type = new MethodType(List.of(syms.intType), site, List.nil(), syms.methodClass);
3493 sc.enter(arrayConstr);
3494 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false);
3495 }
3496
3497 @Override
3498 ReferenceKind referenceKind(Symbol sym) {
3499 return ReferenceKind.ARRAY_CTOR;
3500 }
3501 }
3502
3503 /**
3504 * Helper class for constructor reference lookup. The lookup logic is based
3505 * upon either Resolve.findMethod or Resolve.findDiamond - depending on
3506 * whether the constructor reference needs diamond inference (this is the case
3507 * if the qualifier type is raw). A special erroneous symbol is returned
3508 * if the lookup returns the constructor of an inner class and there's no
3509 * enclosing instance in scope.
3510 */
3511 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper {
3512
3513 boolean needsInference;
3514
3515 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
3516 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3517 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
3518 if (site.isRaw()) {
3519 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym, site.getMetadata());
3520 needsInference = true;
3521 }
3522 }
3523
3524 @Override
3525 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3526 Symbol sym = needsInference ?
3527 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) :
3528 findMethod(env, site, name, argtypes, typeargtypes,
3529 phase.isBoxingRequired(), phase.isVarargsRequired());
3530 return enclosingInstanceMissing(env, site) ? new BadConstructorReferenceError(sym) : sym;
3531 }
3532
3533 @Override
3534 ReferenceKind referenceKind(Symbol sym) {
3535 return site.getEnclosingType().hasTag(NONE) ?
3536 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER;
3537 }
3538 }
3539
3540 /**
3541 * Main overload resolution routine. On each overload resolution step, a
3542 * lookup helper class is used to perform the method/constructor lookup;
3543 * at the end of the lookup, the helper is used to validate the results
3544 * (this last step might trigger overload resolution diagnostics).
3545 */
3546 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, MethodCheck methodCheck, LookupHelper lookupHelper) {
3547 MethodResolutionContext resolveContext = new MethodResolutionContext();
3548 resolveContext.methodCheck = methodCheck;
3549 return lookupMethod(env, pos, location, resolveContext, lookupHelper);
3550 }
3551
3552 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location,
3553 MethodResolutionContext resolveContext, LookupHelper lookupHelper) {
3554 MethodResolutionContext prevResolutionContext = currentResolutionContext;
3555 try {
3556 Symbol bestSoFar = methodNotFound;
3557 currentResolutionContext = resolveContext;
3558 for (MethodResolutionPhase phase : methodResolutionSteps) {
3559 if (lookupHelper.shouldStop(bestSoFar, phase))
3560 break;
3561 MethodResolutionPhase prevPhase = currentResolutionContext.step;
3562 Symbol prevBest = bestSoFar;
3563 currentResolutionContext.step = phase;
3564 Symbol sym = lookupHelper.lookup(env, phase);
3565 lookupHelper.debug(pos, sym);
3566 bestSoFar = phase.mergeResults(bestSoFar, sym);
3567 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase;
3568 }
3569 return lookupHelper.access(env, pos, location, bestSoFar);
3570 } finally {
3571 currentResolutionContext = prevResolutionContext;
3572 }
3573 }
3574
3575 /**
3576 * Resolve `c.name' where name == this or name == super.
3577 * @param pos The position to use for error reporting.
3578 * @param env The environment current at the expression.
3579 * @param c The qualifier.
3580 * @param name The identifier's name.
3581 */
3582 Symbol resolveSelf(DiagnosticPosition pos,
3583 Env<AttrContext> env,
3584 TypeSymbol c,
3585 Name name) {
3586 Env<AttrContext> env1 = env;
3587 boolean staticOnly = false;
3588 while (env1.outer != null) {
3589 if (isStatic(env1)) staticOnly = true;
3590 if (env1.enclClass.sym == c) {
3591 Symbol sym = env1.info.scope.findFirst(name);
3592 if (sym != null) {
3593 if (staticOnly) sym = new StaticError(sym);
3594 return accessBase(sym, pos, env.enclClass.sym.type,
3595 name, true);
3596 }
3597 }
3598 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
3599 env1 = env1.outer;
3600 }
3601 if (c.isInterface() &&
3602 name == names._super && !isStatic(env) &&
3603 types.isDirectSuperInterface(c, env.enclClass.sym)) {
3604 //this might be a default super call if one of the superinterfaces is 'c'
3605 for (Type t : pruneInterfaces(env.enclClass.type)) {
3606 if (t.tsym == c) {
3607 env.info.defaultSuperCallSite = t;
3608 return new VarSymbol(0, names._super,
3609 types.asSuper(env.enclClass.type, c), env.enclClass.sym);
3610 }
3611 }
3612 //find a direct super type that is a subtype of 'c'
3613 for (Type i : types.directSupertypes(env.enclClass.type)) {
3614 if (i.tsym.isSubClass(c, types) && i.tsym != c) {
3615 log.error(pos,
3616 Errors.IllegalDefaultSuperCall(c,
3617 Fragments.RedundantSupertype(c, i)));
3618 return syms.errSymbol;
3619 }
3620 }
3621 Assert.error();
3622 }
3623 log.error(pos, Errors.NotEnclClass(c));
3624 return syms.errSymbol;
3625 }
3626 //where
3627 private List<Type> pruneInterfaces(Type t) {
3628 ListBuffer<Type> result = new ListBuffer<>();
3629 for (Type t1 : types.interfaces(t)) {
3630 boolean shouldAdd = true;
3631 for (Type t2 : types.directSupertypes(t)) {
3632 if (t1 != t2 && types.isSubtypeNoCapture(t2, t1)) {
3633 shouldAdd = false;
3634 }
3635 }
3636 if (shouldAdd) {
3637 result.append(t1);
3638 }
3639 }
3640 return result.toList();
3641 }
3642
3643
3644 /**
3645 * Resolve `c.this' for an enclosing class c that contains the
3646 * named member.
3647 * @param pos The position to use for error reporting.
3648 * @param env The environment current at the expression.
3649 * @param member The member that must be contained in the result.
3650 */
3651 Symbol resolveSelfContaining(DiagnosticPosition pos,
3652 Env<AttrContext> env,
3653 Symbol member,
3654 boolean isSuperCall) {
3655 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall);
3656 if (sym == null) {
3657 log.error(pos, Errors.EnclClassRequired(member));
3658 return syms.errSymbol;
3659 } else {
3660 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true);
3661 }
3662 }
3663
3664 boolean enclosingInstanceMissing(Env<AttrContext> env, Type type) {
3665 if (type.hasTag(CLASS) && type.getEnclosingType().hasTag(CLASS)) {
3666 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false);
3667 return encl == null || encl.kind.isResolutionError();
3668 }
3669 return false;
3670 }
3671
3672 private Symbol resolveSelfContainingInternal(Env<AttrContext> env,
3673 Symbol member,
3674 boolean isSuperCall) {
3675 Name name = names._this;
3676 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
3677 boolean staticOnly = false;
3678 if (env1 != null) {
3679 while (env1 != null && env1.outer != null) {
3680 if (isStatic(env1)) staticOnly = true;
3681 if (env1.enclClass.sym.isSubClass(member.owner.enclClass(), types)) {
3682 Symbol sym = env1.info.scope.findFirst(name);
3683 if (sym != null) {
3684 if (staticOnly) sym = new StaticError(sym);
3685 return sym;
3686 }
3687 }
3688 if ((env1.enclClass.sym.flags() & STATIC) != 0)
3689 staticOnly = true;
3690 env1 = env1.outer;
3691 }
3692 }
3693 return null;
3694 }
3695
3696 /**
3697 * Resolve an appropriate implicit this instance for t's container.
3698 * JLS 8.8.5.1 and 15.9.2
3699 */
3700 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
3701 return resolveImplicitThis(pos, env, t, false);
3702 }
3703
3704 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
3705 Type thisType = (t.tsym.owner.kind.matches(KindSelector.VAL_MTH)
3706 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
3707 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
3708 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym) {
3709 log.error(pos, Errors.CantRefBeforeCtorCalled("this"));
3710 }
3711 return thisType;
3712 }
3713
3714 /* ***************************************************************************
3715 * ResolveError classes, indicating error situations when accessing symbols
3716 ****************************************************************************/
3717
3718 //used by TransTypes when checking target type of synthetic cast
3719 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) {
3720 AccessError error = new AccessError(env, env.enclClass.type, type.tsym);
3721 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null);
3722 }
3723 //where
3724 private void logResolveError(ResolveError error,
3725 DiagnosticPosition pos,
3726 Symbol location,
3727 Type site,
3728 Name name,
3729 List<Type> argtypes,
3730 List<Type> typeargtypes) {
3731 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
3732 pos, location, site, name, argtypes, typeargtypes);
3733 if (d != null) {
3734 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
3735 log.report(d);
3736 }
3737 }
3738
3739 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
3740
3741 public Object methodArguments(List<Type> argtypes) {
3742 if (argtypes == null || argtypes.isEmpty()) {
3743 return noArgs;
3744 } else {
3745 ListBuffer<Object> diagArgs = new ListBuffer<>();
3746 for (Type t : argtypes) {
3747 if (t.hasTag(DEFERRED)) {
3748 diagArgs.append(((DeferredAttr.DeferredType)t).tree);
3749 } else {
3750 diagArgs.append(t);
3751 }
3752 }
3753 return diagArgs;
3754 }
3755 }
3756
3757 /**
3758 * Root class for resolution errors. Subclass of ResolveError
3759 * represent a different kinds of resolution error - as such they must
3760 * specify how they map into concrete compiler diagnostics.
3761 */
3762 abstract class ResolveError extends Symbol {
3763
3764 /** The name of the kind of error, for debugging only. */
3765 final String debugName;
3766
3767 ResolveError(Kind kind, String debugName) {
3768 super(kind, 0, null, null, null);
3769 this.debugName = debugName;
3770 }
3771
3772 @Override @DefinedBy(Api.LANGUAGE_MODEL)
3773 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
3774 throw new AssertionError();
3775 }
3776
3777 @Override
3778 public String toString() {
3779 return debugName;
3780 }
3781
3782 @Override
3783 public boolean exists() {
3784 return false;
3785 }
3786
3787 @Override
3788 public boolean isStatic() {
3789 return false;
3790 }
3791
3792 /**
3793 * Create an external representation for this erroneous symbol to be
3794 * used during attribution - by default this returns the symbol of a
3795 * brand new error type which stores the original type found
3796 * during resolution.
3797 *
3798 * @param name the name used during resolution
3799 * @param location the location from which the symbol is accessed
3800 */
3801 protected Symbol access(Name name, TypeSymbol location) {
3802 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3803 }
3804
3805 /**
3806 * Create a diagnostic representing this resolution error.
3807 *
3808 * @param dkind The kind of the diagnostic to be created (e.g error).
3809 * @param pos The position to be used for error reporting.
3810 * @param site The original type from where the selection took place.
3811 * @param name The name of the symbol to be resolved.
3812 * @param argtypes The invocation's value arguments,
3813 * if we looked for a method.
3814 * @param typeargtypes The invocation's type arguments,
3815 * if we looked for a method.
3816 */
3817 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3818 DiagnosticPosition pos,
3819 Symbol location,
3820 Type site,
3821 Name name,
3822 List<Type> argtypes,
3823 List<Type> typeargtypes);
3824 }
3825
3826 /**
3827 * This class is the root class of all resolution errors caused by
3828 * an invalid symbol being found during resolution.
3829 */
3830 abstract class InvalidSymbolError extends ResolveError {
3831
3832 /** The invalid symbol found during resolution */
3833 Symbol sym;
3834
3835 InvalidSymbolError(Kind kind, Symbol sym, String debugName) {
3836 super(kind, debugName);
3837 this.sym = sym;
3838 }
3839
3840 @Override
3841 public boolean exists() {
3842 return true;
3843 }
3844
3845 @Override
3846 public String toString() {
3847 return super.toString() + " wrongSym=" + sym;
3848 }
3849
3850 @Override
3851 public Symbol access(Name name, TypeSymbol location) {
3852 if (!sym.kind.isResolutionError() && sym.kind.matches(KindSelector.TYP))
3853 return types.createErrorType(name, location, sym.type).tsym;
3854 else
3855 return sym;
3856 }
3857 }
3858
3859 class BadRestrictedTypeError extends ResolveError {
3860 private final Name typeName;
3861 BadRestrictedTypeError(Name typeName) {
3862 super(Kind.BAD_RESTRICTED_TYPE, "bad var use");
3863 this.typeName = typeName;
3864 }
3865
3866 @Override
3867 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
3868 return diags.create(dkind, log.currentSource(), pos, "illegal.ref.to.restricted.type", typeName);
3869 }
3870 }
3871
3872 /**
3873 * InvalidSymbolError error class indicating that a symbol matching a
3874 * given name does not exists in a given site.
3875 */
3876 class SymbolNotFoundError extends ResolveError {
3877
3878 SymbolNotFoundError(Kind kind) {
3879 this(kind, "symbol not found error");
3880 }
3881
3882 SymbolNotFoundError(Kind kind, String debugName) {
3883 super(kind, debugName);
3884 }
3885
3886 @Override
3887 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3888 DiagnosticPosition pos,
3889 Symbol location,
3890 Type site,
3891 Name name,
3892 List<Type> argtypes,
3893 List<Type> typeargtypes) {
3894 argtypes = argtypes == null ? List.nil() : argtypes;
3895 typeargtypes = typeargtypes == null ? List.nil() : typeargtypes;
3896 if (name == names.error)
3897 return null;
3898
3899 boolean hasLocation = false;
3900 if (location == null) {
3901 location = site.tsym;
3902 }
3903 if (!location.name.isEmpty()) {
3904 if (location.kind == PCK && !site.tsym.exists()) {
3905 return diags.create(dkind, log.currentSource(), pos,
3906 "doesnt.exist", location);
3907 }
3908 hasLocation = !location.name.equals(names._this) &&
3909 !location.name.equals(names._super);
3910 }
3911 boolean isConstructor = name == names.init;
3912 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : kind.absentKind();
3913 Name idname = isConstructor ? site.tsym.name : name;
3914 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
3915 if (hasLocation) {
3916 return diags.create(dkind, log.currentSource(), pos,
3917 errKey, kindname, idname, //symbol kindname, name
3918 typeargtypes, args(argtypes), //type parameters and arguments (if any)
3919 getLocationDiag(location, site)); //location kindname, type
3920 }
3921 else {
3922 return diags.create(dkind, log.currentSource(), pos,
3923 errKey, kindname, idname, //symbol kindname, name
3924 typeargtypes, args(argtypes)); //type parameters and arguments (if any)
3925 }
3926 }
3927 //where
3928 private Object args(List<Type> args) {
3929 return args.isEmpty() ? args : methodArguments(args);
3930 }
3931
3932 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
3933 String key = "cant.resolve";
3934 String suffix = hasLocation ? ".location" : "";
3935 switch (kindname) {
3936 case METHOD:
3937 case CONSTRUCTOR: {
3938 suffix += ".args";
3939 suffix += hasTypeArgs ? ".params" : "";
3940 }
3941 }
3942 return key + suffix;
3943 }
3944 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
3945 if (location.kind == VAR) {
3946 return diags.fragment(Fragments.Location1(kindName(location),
3947 location,
3948 location.type));
3949 } else {
3950 return diags.fragment(Fragments.Location(typeKindName(site),
3951 site,
3952 null));
3953 }
3954 }
3955 }
3956
3957 /**
3958 * InvalidSymbolError error class indicating that a given symbol
3959 * (either a method, a constructor or an operand) is not applicable
3960 * given an actual arguments/type argument list.
3961 */
3962 class InapplicableSymbolError extends ResolveError {
3963
3964 protected MethodResolutionContext resolveContext;
3965
3966 InapplicableSymbolError(MethodResolutionContext context) {
3967 this(WRONG_MTH, "inapplicable symbol error", context);
3968 }
3969
3970 protected InapplicableSymbolError(Kind kind, String debugName, MethodResolutionContext context) {
3971 super(kind, debugName);
3972 this.resolveContext = context;
3973 }
3974
3975 @Override
3976 public String toString() {
3977 return super.toString();
3978 }
3979
3980 @Override
3981 public boolean exists() {
3982 return true;
3983 }
3984
3985 @Override
3986 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3987 DiagnosticPosition pos,
3988 Symbol location,
3989 Type site,
3990 Name name,
3991 List<Type> argtypes,
3992 List<Type> typeargtypes) {
3993 if (name == names.error)
3994 return null;
3995
3996 Pair<Symbol, JCDiagnostic> c = errCandidate();
3997 if (compactMethodDiags) {
3998 JCDiagnostic simpleDiag =
3999 MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, c.snd);
4000 if (simpleDiag != null) {
4001 return simpleDiag;
4002 }
4003 }
4004 Symbol ws = c.fst.asMemberOf(site, types);
4005 return diags.create(dkind, log.currentSource(), pos,
4006 "cant.apply.symbol",
4007 kindName(ws),
4008 ws.name == names.init ? ws.owner.name : ws.name,
4009 methodArguments(ws.type.getParameterTypes()),
4010 methodArguments(argtypes),
4011 kindName(ws.owner),
4012 ws.owner.type,
4013 c.snd);
4014 }
4015
4016 @Override
4017 public Symbol access(Name name, TypeSymbol location) {
4018 Symbol sym = bestCandidate();
4019 return types.createErrorType(name, location, sym != null ? sym.type : syms.errSymbol.type).tsym;
4020 }
4021
4022 protected Symbol bestCandidate() {
4023 return errCandidate().fst;
4024 }
4025
4026 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4027 Candidate bestSoFar = null;
4028 for (Candidate c : resolveContext.candidates) {
4029 if (c.isApplicable()) continue;
4030 bestSoFar = c;
4031 }
4032 Assert.checkNonNull(bestSoFar);
4033 return new Pair<>(bestSoFar.sym, bestSoFar.details);
4034 }
4035 }
4036
4037 /**
4038 * ResolveError error class indicating that a symbol (either methods, constructors or operand)
4039 * is not applicable given an actual arguments/type argument list.
4040 */
4041 class InapplicableSymbolsError extends InapplicableSymbolError {
4042
4043 InapplicableSymbolsError(MethodResolutionContext context) {
4044 super(WRONG_MTHS, "inapplicable symbols", context);
4045 }
4046
4047 @Override
4048 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4049 DiagnosticPosition pos,
4050 Symbol location,
4051 Type site,
4052 Name name,
4053 List<Type> argtypes,
4054 List<Type> typeargtypes) {
4055 Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates();
4056 Map<Symbol, JCDiagnostic> filteredCandidates = compactMethodDiags ?
4057 filterCandidates(candidatesMap) :
4058 mapCandidates();
4059 if (filteredCandidates.isEmpty()) {
4060 filteredCandidates = candidatesMap;
4061 }
4062 boolean truncatedDiag = candidatesMap.size() != filteredCandidates.size();
4063 if (filteredCandidates.size() > 1) {
4064 JCDiagnostic err = diags.create(dkind,
4065 null,
4066 truncatedDiag ?
4067 EnumSet.of(DiagnosticFlag.COMPRESSED) :
4068 EnumSet.noneOf(DiagnosticFlag.class),
4069 log.currentSource(),
4070 pos,
4071 "cant.apply.symbols",
4072 name == names.init ? KindName.CONSTRUCTOR : kind.absentKind(),
4073 name == names.init ? site.tsym.name : name,
4074 methodArguments(argtypes));
4075 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(filteredCandidates, site));
4076 } else if (filteredCandidates.size() == 1) {
4077 Map.Entry<Symbol, JCDiagnostic> _e =
4078 filteredCandidates.entrySet().iterator().next();
4079 final Pair<Symbol, JCDiagnostic> p = new Pair<>(_e.getKey(), _e.getValue());
4080 JCDiagnostic d = new InapplicableSymbolError(resolveContext) {
4081 @Override
4082 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4083 return p;
4084 }
4085 }.getDiagnostic(dkind, pos,
4086 location, site, name, argtypes, typeargtypes);
4087 if (truncatedDiag) {
4088 d.setFlag(DiagnosticFlag.COMPRESSED);
4089 }
4090 return d;
4091 } else {
4092 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
4093 location, site, name, argtypes, typeargtypes);
4094 }
4095 }
4096 //where
4097 private Map<Symbol, JCDiagnostic> mapCandidates() {
4098 MostSpecificMap candidates = new MostSpecificMap();
4099 for (Candidate c : resolveContext.candidates) {
4100 if (c.isApplicable()) continue;
4101 candidates.put(c);
4102 }
4103 return candidates;
4104 }
4105
4106 @SuppressWarnings("serial")
4107 private class MostSpecificMap extends LinkedHashMap<Symbol, JCDiagnostic> {
4108 private void put(Candidate c) {
4109 ListBuffer<Symbol> overridden = new ListBuffer<>();
4110 for (Symbol s : keySet()) {
4111 if (s == c.sym) {
4112 continue;
4113 }
4114 if (c.sym.overrides(s, (TypeSymbol)s.owner, types, false)) {
4115 overridden.add(s);
4116 } else if (s.overrides(c.sym, (TypeSymbol)c.sym.owner, types, false)) {
4117 return;
4118 }
4119 }
4120 for (Symbol s : overridden) {
4121 remove(s);
4122 }
4123 put(c.sym, c.details);
4124 }
4125 }
4126
4127 Map<Symbol, JCDiagnostic> filterCandidates(Map<Symbol, JCDiagnostic> candidatesMap) {
4128 Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<>();
4129 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
4130 JCDiagnostic d = _entry.getValue();
4131 if (!new Template(MethodCheckDiag.ARITY_MISMATCH.regex()).matches(d)) {
4132 candidates.put(_entry.getKey(), d);
4133 }
4134 }
4135 return candidates;
4136 }
4137
4138 private List<JCDiagnostic> candidateDetails(Map<Symbol, JCDiagnostic> candidatesMap, Type site) {
4139 List<JCDiagnostic> details = List.nil();
4140 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
4141 Symbol sym = _entry.getKey();
4142 JCDiagnostic detailDiag =
4143 diags.fragment(Fragments.InapplicableMethod(Kinds.kindName(sym),
4144 sym.location(site, types),
4145 sym.asMemberOf(site, types),
4146 _entry.getValue()));
4147 details = details.prepend(detailDiag);
4148 }
4149 //typically members are visited in reverse order (see Scope)
4150 //so we need to reverse the candidate list so that candidates
4151 //conform to source order
4152 return details;
4153 }
4154
4155 @Override
4156 protected Symbol bestCandidate() {
4157 Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates();
4158 Map<Symbol, JCDiagnostic> filteredCandidates = filterCandidates(candidatesMap);
4159 if (filteredCandidates.size() == 1) {
4160 return filteredCandidates.keySet().iterator().next();
4161 }
4162 return null;
4163 }
4164 }
4165
4166 /**
4167 * DiamondError error class indicating that a constructor symbol is not applicable
4168 * given an actual arguments/type argument list using diamond inference.
4169 */
4170 class DiamondError extends InapplicableSymbolError {
4171
4172 Symbol sym;
4173
4174 public DiamondError(Symbol sym, MethodResolutionContext context) {
4175 super(sym.kind, "diamondError", context);
4176 this.sym = sym;
4177 }
4178
4179 JCDiagnostic getDetails() {
4180 return (sym.kind == WRONG_MTH) ?
4181 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd :
4182 null;
4183 }
4184
4185 @Override
4186 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
4187 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4188 JCDiagnostic details = getDetails();
4189 if (details != null && compactMethodDiags) {
4190 JCDiagnostic simpleDiag =
4191 MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, details);
4192 if (simpleDiag != null) {
4193 return simpleDiag;
4194 }
4195 }
4196 String key = details == null ?
4197 "cant.apply.diamond" :
4198 "cant.apply.diamond.1";
4199 return diags.create(dkind, log.currentSource(), pos, key,
4200 Fragments.Diamond(site.tsym), details);
4201 }
4202 }
4203
4204 /**
4205 * An InvalidSymbolError error class indicating that a symbol is not
4206 * accessible from a given site
4207 */
4208 class AccessError extends InvalidSymbolError {
4209
4210 private Env<AttrContext> env;
4211 private Type site;
4212
4213 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
4214 super(HIDDEN, sym, "access error");
4215 this.env = env;
4216 this.site = site;
4217 }
4218
4219 @Override
4220 public boolean exists() {
4221 return false;
4222 }
4223
4224 @Override
4225 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4226 DiagnosticPosition pos,
4227 Symbol location,
4228 Type site,
4229 Name name,
4230 List<Type> argtypes,
4231 List<Type> typeargtypes) {
4232 if (sym.name == names.init && sym.owner != site.tsym) {
4233 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
4234 pos, location, site, name, argtypes, typeargtypes);
4235 }
4236 else if ((sym.flags() & PUBLIC) != 0
4237 || (env != null && this.site != null
4238 && !isAccessible(env, this.site))) {
4239 if (sym.owner.kind == PCK) {
4240 return diags.create(dkind, log.currentSource(),
4241 pos, "not.def.access.package.cant.access",
4242 sym, sym.location(), inaccessiblePackageReason(env, sym.packge()));
4243 } else if ( sym.packge() != syms.rootPackage
4244 && !symbolPackageVisible(env, sym)) {
4245 return diags.create(dkind, log.currentSource(),
4246 pos, "not.def.access.class.intf.cant.access.reason",
4247 sym, sym.location(), sym.location().packge(),
4248 inaccessiblePackageReason(env, sym.packge()));
4249 } else {
4250 return diags.create(dkind, log.currentSource(),
4251 pos, "not.def.access.class.intf.cant.access",
4252 sym, sym.location());
4253 }
4254 }
4255 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
4256 return diags.create(dkind, log.currentSource(),
4257 pos, "report.access", sym,
4258 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
4259 sym.location());
4260 }
4261 else {
4262 return diags.create(dkind, log.currentSource(),
4263 pos, "not.def.public.cant.access", sym, sym.location());
4264 }
4265 }
4266
4267 private String toString(Type type) {
4268 StringBuilder sb = new StringBuilder();
4269 sb.append(type);
4270 if (type != null) {
4271 sb.append("[tsym:").append(type.tsym);
4272 if (type.tsym != null)
4273 sb.append("packge:").append(type.tsym.packge());
4274 sb.append("]");
4275 }
4276 return sb.toString();
4277 }
4278 }
4279
4280 class InvisibleSymbolError extends InvalidSymbolError {
4281
4282 private final Env<AttrContext> env;
4283 private final boolean suppressError;
4284
4285 InvisibleSymbolError(Env<AttrContext> env, boolean suppressError, Symbol sym) {
4286 super(HIDDEN, sym, "invisible class error");
4287 this.env = env;
4288 this.suppressError = suppressError;
4289 this.name = sym.name;
4290 }
4291
4292 @Override
4293 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4294 DiagnosticPosition pos,
4295 Symbol location,
4296 Type site,
4297 Name name,
4298 List<Type> argtypes,
4299 List<Type> typeargtypes) {
4300 if (suppressError)
4301 return null;
4302
4303 if (sym.kind == PCK) {
4304 JCDiagnostic details = inaccessiblePackageReason(env, sym.packge());
4305 return diags.create(dkind, log.currentSource(),
4306 pos, "package.not.visible", sym, details);
4307 }
4308
4309 JCDiagnostic details = inaccessiblePackageReason(env, sym.packge());
4310
4311 if (pos.getTree() != null) {
4312 Symbol o = sym;
4313 JCTree tree = pos.getTree();
4314
4315 while (o.kind != PCK && tree.hasTag(SELECT)) {
4316 o = o.owner;
4317 tree = ((JCFieldAccess) tree).selected;
4318 }
4319
4320 if (o.kind == PCK) {
4321 pos = tree.pos();
4322
4323 return diags.create(dkind, log.currentSource(),
4324 pos, "package.not.visible", o, details);
4325 }
4326 }
4327
4328 return diags.create(dkind, log.currentSource(),
4329 pos, "not.def.access.package.cant.access", sym, sym.packge(), details);
4330 }
4331 }
4332
4333 JCDiagnostic inaccessiblePackageReason(Env<AttrContext> env, PackageSymbol sym) {
4334 //no dependency:
4335 if (!env.toplevel.modle.readModules.contains(sym.modle)) {
4336 //does not read:
4337 if (sym.modle != syms.unnamedModule) {
4338 if (env.toplevel.modle != syms.unnamedModule) {
4339 return diags.fragment(Fragments.NotDefAccessDoesNotRead(env.toplevel.modle,
4340 sym,
4341 sym.modle));
4342 } else {
4343 return diags.fragment(Fragments.NotDefAccessDoesNotReadFromUnnamed(sym,
4344 sym.modle));
4345 }
4346 } else {
4347 return diags.fragment(Fragments.NotDefAccessDoesNotReadUnnamed(sym,
4348 env.toplevel.modle));
4349 }
4350 } else {
4351 if (sym.packge().modle.exports.stream().anyMatch(e -> e.packge == sym)) {
4352 //not exported to this module:
4353 if (env.toplevel.modle != syms.unnamedModule) {
4354 return diags.fragment(Fragments.NotDefAccessNotExportedToModule(sym,
4355 sym.modle,
4356 env.toplevel.modle));
4357 } else {
4358 return diags.fragment(Fragments.NotDefAccessNotExportedToModuleFromUnnamed(sym,
4359 sym.modle));
4360 }
4361 } else {
4362 //not exported:
4363 if (env.toplevel.modle != syms.unnamedModule) {
4364 return diags.fragment(Fragments.NotDefAccessNotExported(sym,
4365 sym.modle));
4366 } else {
4367 return diags.fragment(Fragments.NotDefAccessNotExportedFromUnnamed(sym,
4368 sym.modle));
4369 }
4370 }
4371 }
4372 }
4373
4374 /**
4375 * InvalidSymbolError error class indicating that an instance member
4376 * has erroneously been accessed from a static context.
4377 */
4378 class StaticError extends InvalidSymbolError {
4379
4380 StaticError(Symbol sym) {
4381 super(STATICERR, sym, "static error");
4382 }
4383
4384 @Override
4385 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4386 DiagnosticPosition pos,
4387 Symbol location,
4388 Type site,
4389 Name name,
4390 List<Type> argtypes,
4391 List<Type> typeargtypes) {
4392 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS))
4393 ? types.erasure(sym.type).tsym
4394 : sym);
4395 return diags.create(dkind, log.currentSource(), pos,
4396 "non-static.cant.be.ref", kindName(sym), errSym);
4397 }
4398 }
4399
4400 /**
4401 * InvalidSymbolError error class indicating that a pair of symbols
4402 * (either methods, constructors or operands) are ambiguous
4403 * given an actual arguments/type argument list.
4404 */
4405 class AmbiguityError extends ResolveError {
4406
4407 /** The other maximally specific symbol */
4408 List<Symbol> ambiguousSyms = List.nil();
4409
4410 @Override
4411 public boolean exists() {
4412 return true;
4413 }
4414
4415 AmbiguityError(Symbol sym1, Symbol sym2) {
4416 super(AMBIGUOUS, "ambiguity error");
4417 ambiguousSyms = flatten(sym2).appendList(flatten(sym1));
4418 }
4419
4420 private List<Symbol> flatten(Symbol sym) {
4421 if (sym.kind == AMBIGUOUS) {
4422 return ((AmbiguityError)sym.baseSymbol()).ambiguousSyms;
4423 } else {
4424 return List.of(sym);
4425 }
4426 }
4427
4428 AmbiguityError addAmbiguousSymbol(Symbol s) {
4429 ambiguousSyms = ambiguousSyms.prepend(s);
4430 return this;
4431 }
4432
4433 @Override
4434 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4435 DiagnosticPosition pos,
4436 Symbol location,
4437 Type site,
4438 Name name,
4439 List<Type> argtypes,
4440 List<Type> typeargtypes) {
4441 List<Symbol> diagSyms = ambiguousSyms.reverse();
4442 Symbol s1 = diagSyms.head;
4443 Symbol s2 = diagSyms.tail.head;
4444 Name sname = s1.name;
4445 if (sname == names.init) sname = s1.owner.name;
4446 return diags.create(dkind, log.currentSource(),
4447 pos, "ref.ambiguous", sname,
4448 kindName(s1),
4449 s1,
4450 s1.location(site, types),
4451 kindName(s2),
4452 s2,
4453 s2.location(site, types));
4454 }
4455
4456 /**
4457 * If multiple applicable methods are found during overload and none of them
4458 * is more specific than the others, attempt to merge their signatures.
4459 */
4460 Symbol mergeAbstracts(Type site) {
4461 List<Symbol> ambiguousInOrder = ambiguousSyms.reverse();
4462 return types.mergeAbstracts(ambiguousInOrder, site, true).orElse(this);
4463 }
4464
4465 @Override
4466 protected Symbol access(Name name, TypeSymbol location) {
4467 Symbol firstAmbiguity = ambiguousSyms.last();
4468 return firstAmbiguity.kind == TYP ?
4469 types.createErrorType(name, location, firstAmbiguity.type).tsym :
4470 firstAmbiguity;
4471 }
4472 }
4473
4474 class BadVarargsMethod extends ResolveError {
4475
4476 ResolveError delegatedError;
4477
4478 BadVarargsMethod(ResolveError delegatedError) {
4479 super(delegatedError.kind, "badVarargs");
4480 this.delegatedError = delegatedError;
4481 }
4482
4483 @Override
4484 public Symbol baseSymbol() {
4485 return delegatedError.baseSymbol();
4486 }
4487
4488 @Override
4489 protected Symbol access(Name name, TypeSymbol location) {
4490 return delegatedError.access(name, location);
4491 }
4492
4493 @Override
4494 public boolean exists() {
4495 return true;
4496 }
4497
4498 @Override
4499 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4500 return delegatedError.getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes);
4501 }
4502 }
4503
4504 /**
4505 * BadMethodReferenceError error class indicating that a method reference symbol has been found,
4506 * but with the wrong staticness.
4507 */
4508 class BadMethodReferenceError extends StaticError {
4509
4510 boolean unboundLookup;
4511
4512 public BadMethodReferenceError(Symbol sym, boolean unboundLookup) {
4513 super(sym);
4514 this.unboundLookup = unboundLookup;
4515 }
4516
4517 @Override
4518 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4519 final String key;
4520 if (!unboundLookup) {
4521 key = "bad.static.method.in.bound.lookup";
4522 } else if (sym.isStatic()) {
4523 key = "bad.static.method.in.unbound.lookup";
4524 } else {
4525 key = "bad.instance.method.in.unbound.lookup";
4526 }
4527 return sym.kind.isResolutionError() ?
4528 ((ResolveError)sym).getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes) :
4529 diags.create(dkind, log.currentSource(), pos, key, Kinds.kindName(sym), sym);
4530 }
4531 }
4532
4533 /**
4534 * BadConstructorReferenceError error class indicating that a constructor reference symbol has been found,
4535 * but pointing to a class for which an enclosing instance is not available.
4536 */
4537 class BadConstructorReferenceError extends InvalidSymbolError {
4538
4539 public BadConstructorReferenceError(Symbol sym) {
4540 super(MISSING_ENCL, sym, "BadConstructorReferenceError");
4541 }
4542
4543 @Override
4544 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4545 return diags.create(dkind, log.currentSource(), pos,
4546 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType());
4547 }
4548 }
4549
4550 class BadClassFileError extends InvalidSymbolError {
4551
4552 private final CompletionFailure ex;
4553
4554 public BadClassFileError(CompletionFailure ex) {
4555 super(HIDDEN, ex.sym, "BadClassFileError");
4556 this.name = sym.name;
4557 this.ex = ex;
4558 }
4559
4560 @Override
4561 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4562 JCDiagnostic d = diags.create(dkind, log.currentSource(), pos,
4563 "cant.access", ex.sym, ex.getDetailValue());
4564
4565 d.setFlag(DiagnosticFlag.NON_DEFERRABLE);
4566 return d;
4567 }
4568
4569 }
4570
4571 /**
4572 * Helper class for method resolution diagnostic simplification.
4573 * Certain resolution diagnostic are rewritten as simpler diagnostic
4574 * where the enclosing resolution diagnostic (i.e. 'inapplicable method')
4575 * is stripped away, as it doesn't carry additional info. The logic
4576 * for matching a given diagnostic is given in terms of a template
4577 * hierarchy: a diagnostic template can be specified programmatically,
4578 * so that only certain diagnostics are matched. Each templete is then
4579 * associated with a rewriter object that carries out the task of rewtiting
4580 * the diagnostic to a simpler one.
4581 */
4582 static class MethodResolutionDiagHelper {
4583
4584 /**
4585 * A diagnostic rewriter transforms a method resolution diagnostic
4586 * into a simpler one
4587 */
4588 interface DiagnosticRewriter {
4589 JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
4590 DiagnosticPosition preferredPos, DiagnosticSource preferredSource,
4591 DiagnosticType preferredKind, JCDiagnostic d);
4592 }
4593
4594 /**
4595 * A diagnostic template is made up of two ingredients: (i) a regular
4596 * expression for matching a diagnostic key and (ii) a list of sub-templates
4597 * for matching diagnostic arguments.
4598 */
4599 static class Template {
4600
4601 /** regex used to match diag key */
4602 String regex;
4603
4604 /** templates used to match diagnostic args */
4605 Template[] subTemplates;
4606
4607 Template(String key, Template... subTemplates) {
4608 this.regex = key;
4609 this.subTemplates = subTemplates;
4610 }
4611
4612 /**
4613 * Returns true if the regex matches the diagnostic key and if
4614 * all diagnostic arguments are matches by corresponding sub-templates.
4615 */
4616 boolean matches(Object o) {
4617 JCDiagnostic d = (JCDiagnostic)o;
4618 Object[] args = d.getArgs();
4619 if (!d.getCode().matches(regex) ||
4620 subTemplates.length != d.getArgs().length) {
4621 return false;
4622 }
4623 for (int i = 0; i < args.length ; i++) {
4624 if (!subTemplates[i].matches(args[i])) {
4625 return false;
4626 }
4627 }
4628 return true;
4629 }
4630 }
4631
4632 /**
4633 * Common rewriter for all argument mismatch simplifications.
4634 */
4635 static class ArgMismatchRewriter implements DiagnosticRewriter {
4636
4637 /** the index of the subdiagnostic to be used as primary. */
4638 int causeIndex;
4639
4640 public ArgMismatchRewriter(int causeIndex) {
4641 this.causeIndex = causeIndex;
4642 }
4643
4644 @Override
4645 public JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
4646 DiagnosticPosition preferredPos, DiagnosticSource preferredSource,
4647 DiagnosticType preferredKind, JCDiagnostic d) {
4648 JCDiagnostic cause = (JCDiagnostic)d.getArgs()[causeIndex];
4649 DiagnosticPosition pos = d.getDiagnosticPosition();
4650 if (pos == null) {
4651 pos = preferredPos;
4652 }
4653 return diags.create(preferredKind, preferredSource, pos,
4654 "prob.found.req", cause);
4655 }
4656 }
4657
4658 /** a dummy template that match any diagnostic argument */
4659 static final Template skip = new Template("") {
4660 @Override
4661 boolean matches(Object d) {
4662 return true;
4663 }
4664 };
4665
4666 /** template for matching inference-free arguments mismatch failures */
4667 static final Template argMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip);
4668
4669 /** template for matching inference related arguments mismatch failures */
4670 static final Template inferArgMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip, skip) {
4671 @Override
4672 boolean matches(Object o) {
4673 if (!super.matches(o)) {
4674 return false;
4675 }
4676 JCDiagnostic d = (JCDiagnostic)o;
4677 @SuppressWarnings("unchecked")
4678 List<Type> tvars = (List<Type>)d.getArgs()[0];
4679 return !containsAny(d, tvars);
4680 }
4681
4682 BiPredicate<Object, List<Type>> containsPredicate = (o, ts) -> {
4683 if (o instanceof Type) {
4684 return ((Type)o).containsAny(ts);
4685 } else if (o instanceof JCDiagnostic) {
4686 return containsAny((JCDiagnostic)o, ts);
4687 } else {
4688 return false;
4689 }
4690 };
4691
4692 boolean containsAny(JCDiagnostic d, List<Type> ts) {
4693 return Stream.of(d.getArgs())
4694 .anyMatch(o -> containsPredicate.test(o, ts));
4695 }
4696 };
4697
4698 /** rewriter map used for method resolution simplification */
4699 static final Map<Template, DiagnosticRewriter> rewriters = new LinkedHashMap<>();
4700
4701 static {
4702 rewriters.put(argMismatchTemplate, new ArgMismatchRewriter(0));
4703 rewriters.put(inferArgMismatchTemplate, new ArgMismatchRewriter(1));
4704 }
4705
4706 /**
4707 * Main entry point for diagnostic rewriting - given a diagnostic, see if any templates matches it,
4708 * and rewrite it accordingly.
4709 */
4710 static JCDiagnostic rewrite(JCDiagnostic.Factory diags, DiagnosticPosition pos, DiagnosticSource source,
4711 DiagnosticType dkind, JCDiagnostic d) {
4712 for (Map.Entry<Template, DiagnosticRewriter> _entry : rewriters.entrySet()) {
4713 if (_entry.getKey().matches(d)) {
4714 JCDiagnostic simpleDiag =
4715 _entry.getValue().rewriteDiagnostic(diags, pos, source, dkind, d);
4716 simpleDiag.setFlag(DiagnosticFlag.COMPRESSED);
4717 return simpleDiag;
4718 }
4719 }
4720 return null;
4721 }
4722 }
4723
4724 enum MethodResolutionPhase {
4725 BASIC(false, false),
4726 BOX(true, false),
4727 VARARITY(true, true) {
4728 @Override
4729 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) {
4730 //Check invariants (see {@code LookupHelper.shouldStop})
4731 Assert.check(bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS);
4732 if (!sym.kind.isResolutionError()) {
4733 //varargs resolution successful
4734 return sym;
4735 } else {
4736 //pick best error
4737 switch (bestSoFar.kind) {
4738 case WRONG_MTH:
4739 case WRONG_MTHS:
4740 //Override previous errors if they were caused by argument mismatch.
4741 //This generally means preferring current symbols - but we need to pay
4742 //attention to the fact that the varargs lookup returns 'less' candidates
4743 //than the previous rounds, and adjust that accordingly.
4744 switch (sym.kind) {
4745 case WRONG_MTH:
4746 //if the previous round matched more than one method, return that
4747 //result instead
4748 return bestSoFar.kind == WRONG_MTHS ?
4749 bestSoFar : sym;
4750 case ABSENT_MTH:
4751 //do not override erroneous symbol if the arity lookup did not
4752 //match any method
4753 return bestSoFar;
4754 case WRONG_MTHS:
4755 default:
4756 //safe to override
4757 return sym;
4758 }
4759 default:
4760 //otherwise, return first error
4761 return bestSoFar;
4762 }
4763 }
4764 }
4765 };
4766
4767 final boolean isBoxingRequired;
4768 final boolean isVarargsRequired;
4769
4770 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
4771 this.isBoxingRequired = isBoxingRequired;
4772 this.isVarargsRequired = isVarargsRequired;
4773 }
4774
4775 public boolean isBoxingRequired() {
4776 return isBoxingRequired;
4777 }
4778
4779 public boolean isVarargsRequired() {
4780 return isVarargsRequired;
4781 }
4782
4783 public Symbol mergeResults(Symbol prev, Symbol sym) {
4784 return sym;
4785 }
4786 }
4787
4788 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
4789
4790 /**
4791 * A resolution context is used to keep track of intermediate results of
4792 * overload resolution, such as list of method that are not applicable
4793 * (used to generate more precise diagnostics) and so on. Resolution contexts
4794 * can be nested - this means that when each overload resolution routine should
4795 * work within the resolution context it created.
4796 */
4797 class MethodResolutionContext {
4798
4799 private List<Candidate> candidates = List.nil();
4800
4801 MethodResolutionPhase step = null;
4802
4803 MethodCheck methodCheck = resolveMethodCheck;
4804
4805 private boolean internalResolution = false;
4806 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE;
4807
4808 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) {
4809 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null);
4810 candidates = candidates.append(c);
4811 }
4812
4813 void addApplicableCandidate(Symbol sym, Type mtype) {
4814 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype);
4815 candidates = candidates.append(c);
4816 }
4817
4818 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext, ResultInfo pendingResult, Warner warn) {
4819 DeferredAttrContext parent = (pendingResult == null)
4820 ? deferredAttr.emptyDeferredAttrContext
4821 : pendingResult.checkContext.deferredAttrContext();
4822 return deferredAttr.new DeferredAttrContext(attrMode, sym, step,
4823 inferenceContext, parent, warn);
4824 }
4825
4826 /**
4827 * This class represents an overload resolution candidate. There are two
4828 * kinds of candidates: applicable methods and inapplicable methods;
4829 * applicable methods have a pointer to the instantiated method type,
4830 * while inapplicable candidates contain further details about the
4831 * reason why the method has been considered inapplicable.
4832 */
4833 @SuppressWarnings("overrides")
4834 class Candidate {
4835
4836 final MethodResolutionPhase step;
4837 final Symbol sym;
4838 final JCDiagnostic details;
4839 final Type mtype;
4840
4841 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) {
4842 this.step = step;
4843 this.sym = sym;
4844 this.details = details;
4845 this.mtype = mtype;
4846 }
4847
4848 boolean isApplicable() {
4849 return mtype != null;
4850 }
4851 }
4852
4853 DeferredAttr.AttrMode attrMode() {
4854 return attrMode;
4855 }
4856
4857 boolean internal() {
4858 return internalResolution;
4859 }
4860 }
4861
4862 MethodResolutionContext currentResolutionContext = null;
4863 }