1 /*
2 * Copyright (c) 1999, 2013, 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.Symbol.*;
31 import com.sun.tools.javac.code.Type.*;
32 import com.sun.tools.javac.comp.Attr.ResultInfo;
33 import com.sun.tools.javac.comp.Check.CheckContext;
34 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
35 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
36 import com.sun.tools.javac.comp.DeferredAttr.DeferredType;
37 import com.sun.tools.javac.comp.Infer.InferenceContext;
38 import com.sun.tools.javac.comp.Infer.FreeTypeListener;
39 import com.sun.tools.javac.comp.Resolve.MethodResolutionContext.Candidate;
40 import com.sun.tools.javac.jvm.*;
41 import com.sun.tools.javac.tree.*;
42 import com.sun.tools.javac.tree.JCTree.*;
43 import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind;
44 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
45 import com.sun.tools.javac.util.*;
46 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
47 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
48 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
49
50 import java.util.Arrays;
51 import java.util.Collection;
52 import java.util.EnumMap;
53 import java.util.EnumSet;
54 import java.util.Iterator;
55 import java.util.LinkedHashMap;
56 import java.util.LinkedHashSet;
57 import java.util.Map;
58
59 import javax.lang.model.element.ElementVisitor;
60
61 import static com.sun.tools.javac.code.Flags.*;
62 import static com.sun.tools.javac.code.Flags.BLOCK;
63 import static com.sun.tools.javac.code.Kinds.*;
64 import static com.sun.tools.javac.code.Kinds.ERRONEOUS;
65 import static com.sun.tools.javac.code.TypeTag.*;
66 import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*;
67 import static com.sun.tools.javac.tree.JCTree.Tag.*;
68
69 /** Helper class for name resolution, used mostly by the attribution phase.
70 *
71 * <p><b>This is NOT part of any supported API.
72 * If you write code that depends on this, you do so at your own risk.
73 * This code and its internal interfaces are subject to change or
74 * deletion without notice.</b>
75 */
76 public class Resolve {
77 protected static final Context.Key<Resolve> resolveKey =
78 new Context.Key<Resolve>();
79
80 Names names;
81 Log log;
82 Symtab syms;
83 Attr attr;
84 DeferredAttr deferredAttr;
85 Check chk;
86 Infer infer;
87 ClassReader reader;
88 TreeInfo treeinfo;
89 Types types;
90 JCDiagnostic.Factory diags;
91 public final boolean boxingEnabled; // = source.allowBoxing();
92 public final boolean varargsEnabled; // = source.allowVarargs();
93 public final boolean allowMethodHandles;
94 public final boolean allowDefaultMethods;
95 public final boolean allowStructuralMostSpecific;
96 private final boolean debugResolve;
97 final EnumSet<VerboseResolutionMode> verboseResolutionMode;
98
99 Scope polymorphicSignatureScope;
100
101 protected Resolve(Context context) {
102 context.put(resolveKey, this);
103 syms = Symtab.instance(context);
104
105 varNotFound = new
106 SymbolNotFoundError(ABSENT_VAR);
107 methodNotFound = new
108 SymbolNotFoundError(ABSENT_MTH);
109 typeNotFound = new
110 SymbolNotFoundError(ABSENT_TYP);
111
112 names = Names.instance(context);
113 log = Log.instance(context);
114 attr = Attr.instance(context);
115 deferredAttr = DeferredAttr.instance(context);
116 chk = Check.instance(context);
117 infer = Infer.instance(context);
118 reader = ClassReader.instance(context);
119 treeinfo = TreeInfo.instance(context);
120 types = Types.instance(context);
121 diags = JCDiagnostic.Factory.instance(context);
122 Source source = Source.instance(context);
123 boxingEnabled = source.allowBoxing();
124 varargsEnabled = source.allowVarargs();
125 Options options = Options.instance(context);
126 debugResolve = options.isSet("debugresolve");
127 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
128 Target target = Target.instance(context);
129 allowMethodHandles = target.hasMethodHandles();
130 allowDefaultMethods = source.allowDefaultMethods();
131 allowStructuralMostSpecific = source.allowStructuralMostSpecific();
132 polymorphicSignatureScope = new Scope(syms.noSymbol);
133
134 inapplicableMethodException = new InapplicableMethodException(diags);
135 }
136
137 /** error symbols, which are returned when resolution fails
138 */
139 private final SymbolNotFoundError varNotFound;
140 private final SymbolNotFoundError methodNotFound;
141 private final SymbolNotFoundError typeNotFound;
142
143 public static Resolve instance(Context context) {
144 Resolve instance = context.get(resolveKey);
145 if (instance == null)
146 instance = new Resolve(context);
147 return instance;
148 }
149
150 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support">
151 enum VerboseResolutionMode {
152 SUCCESS("success"),
153 FAILURE("failure"),
154 APPLICABLE("applicable"),
155 INAPPLICABLE("inapplicable"),
156 DEFERRED_INST("deferred-inference"),
157 PREDEF("predef"),
158 OBJECT_INIT("object-init"),
159 INTERNAL("internal");
160
161 final String opt;
162
163 private VerboseResolutionMode(String opt) {
164 this.opt = opt;
165 }
166
167 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) {
168 String s = opts.get("verboseResolution");
169 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class);
170 if (s == null) return res;
171 if (s.contains("all")) {
172 res = EnumSet.allOf(VerboseResolutionMode.class);
173 }
174 Collection<String> args = Arrays.asList(s.split(","));
175 for (VerboseResolutionMode mode : values()) {
176 if (args.contains(mode.opt)) {
177 res.add(mode);
178 } else if (args.contains("-" + mode.opt)) {
179 res.remove(mode);
180 }
181 }
182 return res;
183 }
184 }
185
186 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site,
187 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) {
188 boolean success = bestSoFar.kind < ERRONEOUS;
189
190 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) {
191 return;
192 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) {
193 return;
194 }
195
196 if (bestSoFar.name == names.init &&
197 bestSoFar.owner == syms.objectType.tsym &&
198 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) {
199 return; //skip diags for Object constructor resolution
200 } else if (site == syms.predefClass.type &&
201 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) {
202 return; //skip spurious diags for predef symbols (i.e. operators)
203 } else if (currentResolutionContext.internalResolution &&
204 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) {
205 return;
206 }
207
208 int pos = 0;
209 int mostSpecificPos = -1;
210 ListBuffer<JCDiagnostic> subDiags = ListBuffer.lb();
211 for (Candidate c : currentResolutionContext.candidates) {
212 if (currentResolutionContext.step != c.step ||
213 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) ||
214 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) {
215 continue;
216 } else {
217 subDiags.append(c.isApplicable() ?
218 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) :
219 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details));
220 if (c.sym == bestSoFar)
221 mostSpecificPos = pos;
222 pos++;
223 }
224 }
225 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1";
226 List<Type> argtypes2 = Type.map(argtypes,
227 deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step));
228 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name,
229 site.tsym, mostSpecificPos, currentResolutionContext.step,
230 methodArguments(argtypes2),
231 methodArguments(typeargtypes));
232 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
233 log.report(d);
234 }
235
236 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) {
237 JCDiagnostic subDiag = null;
238 if (sym.type.hasTag(FORALL)) {
239 subDiag = diags.fragment("partial.inst.sig", inst);
240 }
241
242 String key = subDiag == null ?
243 "applicable.method.found" :
244 "applicable.method.found.1";
245
246 return diags.fragment(key, pos, sym, subDiag);
247 }
248
249 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) {
250 return diags.fragment("not.applicable.method.found", pos, sym, subDiag);
251 }
252 // </editor-fold>
253
254 /* ************************************************************************
255 * Identifier resolution
256 *************************************************************************/
257
258 /** An environment is "static" if its static level is greater than
259 * the one of its outer environment
260 */
261 protected static boolean isStatic(Env<AttrContext> env) {
262 return env.info.staticLevel > env.outer.info.staticLevel;
263 }
264
265 /** An environment is an "initializer" if it is a constructor or
266 * an instance initializer.
267 */
268 static boolean isInitializer(Env<AttrContext> env) {
269 Symbol owner = env.info.scope.owner;
270 return owner.isConstructor() ||
271 owner.owner.kind == TYP &&
272 (owner.kind == VAR ||
273 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
274 (owner.flags() & STATIC) == 0;
275 }
276
277 /** Is class accessible in given evironment?
278 * @param env The current environment.
279 * @param c The class whose accessibility is checked.
280 */
281 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
282 return isAccessible(env, c, false);
283 }
284
285 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) {
286 boolean isAccessible = false;
287 switch ((short)(c.flags() & AccessFlags)) {
288 case PRIVATE:
289 isAccessible =
290 env.enclClass.sym.outermostClass() ==
291 c.owner.outermostClass();
292 break;
293 case 0:
294 isAccessible =
295 env.toplevel.packge == c.owner // fast special case
296 ||
297 env.toplevel.packge == c.packge()
298 ||
299 // Hack: this case is added since synthesized default constructors
300 // of anonymous classes should be allowed to access
301 // classes which would be inaccessible otherwise.
302 env.enclMethod != null &&
303 (env.enclMethod.mods.flags & ANONCONSTR) != 0;
304 break;
305 default: // error recovery
306 case PUBLIC:
307 isAccessible = true;
308 break;
309 case PROTECTED:
310 isAccessible =
311 env.toplevel.packge == c.owner // fast special case
312 ||
313 env.toplevel.packge == c.packge()
314 ||
315 isInnerSubClass(env.enclClass.sym, c.owner);
316 break;
317 }
318 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
319 isAccessible :
320 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
321 }
322 //where
323 /** Is given class a subclass of given base class, or an inner class
324 * of a subclass?
325 * Return null if no such class exists.
326 * @param c The class which is the subclass or is contained in it.
327 * @param base The base class
328 */
329 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
330 while (c != null && !c.isSubClass(base, types)) {
331 c = c.owner.enclClass();
332 }
333 return c != null;
334 }
335
336 boolean isAccessible(Env<AttrContext> env, Type t) {
337 return isAccessible(env, t, false);
338 }
339
340 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) {
341 return (t.hasTag(ARRAY))
342 ? isAccessible(env, types.elemtype(t))
343 : isAccessible(env, t.tsym, checkInner);
344 }
345
346 /** Is symbol accessible as a member of given type in given evironment?
347 * @param env The current environment.
348 * @param site The type of which the tested symbol is regarded
349 * as a member.
350 * @param sym The symbol.
351 */
352 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
353 return isAccessible(env, site, sym, false);
354 }
355 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) {
356 if (sym.name == names.init && sym.owner != site.tsym) return false;
357 switch ((short)(sym.flags() & AccessFlags)) {
358 case PRIVATE:
359 return
360 (env.enclClass.sym == sym.owner // fast special case
361 ||
362 env.enclClass.sym.outermostClass() ==
363 sym.owner.outermostClass())
364 &&
365 sym.isInheritedIn(site.tsym, types);
366 case 0:
367 return
368 (env.toplevel.packge == sym.owner.owner // fast special case
369 ||
370 env.toplevel.packge == sym.packge())
371 &&
372 isAccessible(env, site, checkInner)
373 &&
374 sym.isInheritedIn(site.tsym, types)
375 &&
376 notOverriddenIn(site, sym);
377 case PROTECTED:
378 return
379 (env.toplevel.packge == sym.owner.owner // fast special case
380 ||
381 env.toplevel.packge == sym.packge()
382 ||
383 isProtectedAccessible(sym, env.enclClass.sym, site)
384 ||
385 // OK to select instance method or field from 'super' or type name
386 // (but type names should be disallowed elsewhere!)
387 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
388 &&
389 isAccessible(env, site, checkInner)
390 &&
391 notOverriddenIn(site, sym);
392 default: // this case includes erroneous combinations as well
393 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
394 }
395 }
396 //where
397 /* `sym' is accessible only if not overridden by
398 * another symbol which is a member of `site'
399 * (because, if it is overridden, `sym' is not strictly
400 * speaking a member of `site'). A polymorphic signature method
401 * cannot be overridden (e.g. MH.invokeExact(Object[])).
402 */
403 private boolean notOverriddenIn(Type site, Symbol sym) {
404 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
405 return true;
406 else {
407 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
408 return (s2 == null || s2 == sym || sym.owner == s2.owner ||
409 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
410 }
411 }
412 //where
413 /** Is given protected symbol accessible if it is selected from given site
414 * and the selection takes place in given class?
415 * @param sym The symbol with protected access
416 * @param c The class where the access takes place
417 * @site The type of the qualifier
418 */
419 private
420 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
421 while (c != null &&
422 !(c.isSubClass(sym.owner, types) &&
423 (c.flags() & INTERFACE) == 0 &&
424 // In JLS 2e 6.6.2.1, the subclass restriction applies
425 // only to instance fields and methods -- types are excluded
426 // regardless of whether they are declared 'static' or not.
427 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || site.tsym.isSubClass(c, types))))
428 c = c.owner.enclClass();
429 return c != null;
430 }
431
432 /**
433 * Performs a recursive scan of a type looking for accessibility problems
434 * from current attribution environment
435 */
436 void checkAccessibleType(Env<AttrContext> env, Type t) {
437 accessibilityChecker.visit(t, env);
438 }
439
440 /**
441 * Accessibility type-visitor
442 */
443 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker =
444 new Types.SimpleVisitor<Void, Env<AttrContext>>() {
445
446 void visit(List<Type> ts, Env<AttrContext> env) {
447 for (Type t : ts) {
448 visit(t, env);
449 }
450 }
451
452 public Void visitType(Type t, Env<AttrContext> env) {
453 return null;
454 }
455
456 @Override
457 public Void visitArrayType(ArrayType t, Env<AttrContext> env) {
458 visit(t.elemtype, env);
459 return null;
460 }
461
462 @Override
463 public Void visitClassType(ClassType t, Env<AttrContext> env) {
464 visit(t.getTypeArguments(), env);
465 if (!isAccessible(env, t, true)) {
466 accessBase(new AccessError(t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true);
467 }
468 return null;
469 }
470
471 @Override
472 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) {
473 visit(t.type, env);
474 return null;
475 }
476
477 @Override
478 public Void visitMethodType(MethodType t, Env<AttrContext> env) {
479 visit(t.getParameterTypes(), env);
480 visit(t.getReturnType(), env);
481 visit(t.getThrownTypes(), env);
482 return null;
483 }
484 };
485
486 /** Try to instantiate the type of a method so that it fits
487 * given type arguments and argument types. If succesful, return
488 * the method's instantiated type, else return null.
489 * The instantiation will take into account an additional leading
490 * formal parameter if the method is an instance method seen as a member
491 * of un underdetermined site In this case, we treat site as an additional
492 * parameter and the parameters of the class containing the method as
493 * additional type variables that get instantiated.
494 *
495 * @param env The current environment
496 * @param site The type of which the method is a member.
497 * @param m The method symbol.
498 * @param argtypes The invocation's given value arguments.
499 * @param typeargtypes The invocation's given type arguments.
500 * @param allowBoxing Allow boxing conversions of arguments.
501 * @param useVarargs Box trailing arguments into an array for varargs.
502 */
503 Type rawInstantiate(Env<AttrContext> env,
504 Type site,
505 Symbol m,
506 ResultInfo resultInfo,
507 List<Type> argtypes,
508 List<Type> typeargtypes,
509 boolean allowBoxing,
510 boolean useVarargs,
511 Warner warn) throws Infer.InferenceException {
512
513 Type mt = types.memberType(site, m);
514 // tvars is the list of formal type variables for which type arguments
515 // need to inferred.
516 List<Type> tvars = List.nil();
517 if (typeargtypes == null) typeargtypes = List.nil();
518 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
519 // This is not a polymorphic method, but typeargs are supplied
520 // which is fine, see JLS 15.12.2.1
521 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
522 ForAll pmt = (ForAll) mt;
523 if (typeargtypes.length() != pmt.tvars.length())
524 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args
525 // Check type arguments are within bounds
526 List<Type> formals = pmt.tvars;
527 List<Type> actuals = typeargtypes;
528 while (formals.nonEmpty() && actuals.nonEmpty()) {
529 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
530 pmt.tvars, typeargtypes);
531 for (; bounds.nonEmpty(); bounds = bounds.tail)
532 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn))
533 throw inapplicableMethodException.setMessage("explicit.param.do.not.conform.to.bounds",actuals.head, bounds);
534 formals = formals.tail;
535 actuals = actuals.tail;
536 }
537 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
538 } else if (mt.hasTag(FORALL)) {
539 ForAll pmt = (ForAll) mt;
540 List<Type> tvars1 = types.newInstances(pmt.tvars);
541 tvars = tvars.appendList(tvars1);
542 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
543 }
544
545 // find out whether we need to go the slow route via infer
546 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/
547 for (List<Type> l = argtypes;
548 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
549 l = l.tail) {
550 if (l.head.hasTag(FORALL)) instNeeded = true;
551 }
552
553 if (instNeeded)
554 return infer.instantiateMethod(env,
555 tvars,
556 (MethodType)mt,
557 resultInfo,
558 m,
559 argtypes,
560 allowBoxing,
561 useVarargs,
562 currentResolutionContext,
563 warn);
564
565 currentResolutionContext.methodCheck.argumentsAcceptable(env, currentResolutionContext.deferredAttrContext(m, infer.emptyContext, resultInfo, warn),
566 argtypes, mt.getParameterTypes(), warn);
567 return mt;
568 }
569
570 Type checkMethod(Env<AttrContext> env,
571 Type site,
572 Symbol m,
573 ResultInfo resultInfo,
574 List<Type> argtypes,
575 List<Type> typeargtypes,
576 Warner warn) {
577 MethodResolutionContext prevContext = currentResolutionContext;
578 try {
579 currentResolutionContext = new MethodResolutionContext();
580 currentResolutionContext.attrMode = DeferredAttr.AttrMode.CHECK;
581 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase;
582 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
583 step.isBoxingRequired(), step.isVarargsRequired(), warn);
584 }
585 finally {
586 currentResolutionContext = prevContext;
587 }
588 }
589
590 /** Same but returns null instead throwing a NoInstanceException
591 */
592 Type instantiate(Env<AttrContext> env,
593 Type site,
594 Symbol m,
595 ResultInfo resultInfo,
596 List<Type> argtypes,
597 List<Type> typeargtypes,
598 boolean allowBoxing,
599 boolean useVarargs,
600 Warner warn) {
601 try {
602 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
603 allowBoxing, useVarargs, warn);
604 } catch (InapplicableMethodException ex) {
605 return null;
606 }
607 }
608
609 /**
610 * This interface defines an entry point that should be used to perform a
611 * method check. A method check usually consist in determining as to whether
612 * a set of types (actuals) is compatible with another set of types (formals).
613 * Since the notion of compatibility can vary depending on the circumstances,
614 * this interfaces allows to easily add new pluggable method check routines.
615 */
616 interface MethodCheck {
617 /**
618 * Main method check routine. A method check usually consist in determining
619 * as to whether a set of types (actuals) is compatible with another set of
620 * types (formals). If an incompatibility is found, an unchecked exception
621 * is assumed to be thrown.
622 */
623 void argumentsAcceptable(Env<AttrContext> env,
624 DeferredAttrContext deferredAttrContext,
625 List<Type> argtypes,
626 List<Type> formals,
627 Warner warn);
628
629 /**
630 * Retrieve the method check object that will be used during a
631 * most specific check.
632 */
633 MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict);
634 }
635
636 /**
637 * Helper enum defining all method check diagnostics (used by resolveMethodCheck).
638 */
639 enum MethodCheckDiag {
640 /**
641 * Actuals and formals differs in length.
642 */
643 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"),
644 /**
645 * An actual is incompatible with a formal.
646 */
647 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"),
648 /**
649 * An actual is incompatible with the varargs element type.
650 */
651 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"),
652 /**
653 * The varargs element type is inaccessible.
654 */
655 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type");
656
657 final String basicKey;
658 final String inferKey;
659
660 MethodCheckDiag(String basicKey, String inferKey) {
661 this.basicKey = basicKey;
662 this.inferKey = inferKey;
663 }
664 }
665
666 /**
667 * Dummy method check object. All methods are deemed applicable, regardless
668 * of their formal parameter types.
669 */
670 MethodCheck nilMethodCheck = new MethodCheck() {
671 public void argumentsAcceptable(Env<AttrContext> env, DeferredAttrContext deferredAttrContext, List<Type> argtypes, List<Type> formals, Warner warn) {
672 //do nothing - method always applicable regardless of actuals
673 }
674
675 public MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict) {
676 return this;
677 }
678 };
679
680 /**
681 * Base class for 'real' method checks. The class defines the logic for
682 * iterating through formals and actuals and provides and entry point
683 * that can be used by subclasses in order to define the actual check logic.
684 */
685 abstract class AbstractMethodCheck implements MethodCheck {
686 @Override
687 public void argumentsAcceptable(final Env<AttrContext> env,
688 DeferredAttrContext deferredAttrContext,
689 List<Type> argtypes,
690 List<Type> formals,
691 Warner warn) {
692 //should we expand formals?
693 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired();
694
695 //inference context used during this method check
696 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
697
698 Type varargsFormal = useVarargs ? formals.last() : null;
699
700 if (varargsFormal == null &&
701 argtypes.size() != formals.size()) {
702 reportMC(MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
703 }
704
705 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
706 checkArg(false, argtypes.head, formals.head, deferredAttrContext, warn);
707 argtypes = argtypes.tail;
708 formals = formals.tail;
709 }
710
711 if (formals.head != varargsFormal) {
712 reportMC(MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
713 }
714
715 if (useVarargs) {
716 //note: if applicability check is triggered by most specific test,
717 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
718 final Type elt = types.elemtype(varargsFormal);
719 while (argtypes.nonEmpty()) {
720 checkArg(true, argtypes.head, elt, deferredAttrContext, warn);
721 argtypes = argtypes.tail;
722 }
723 }
724 }
725
726 /**
727 * Does the actual argument conforms to the corresponding formal?
728 */
729 abstract void checkArg(boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn);
730
731 protected void reportMC(MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
732 boolean inferDiag = inferenceContext != infer.emptyContext;
733 InapplicableMethodException ex = inferDiag ?
734 infer.inferenceException : inapplicableMethodException;
735 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) {
736 Object[] args2 = new Object[args.length + 1];
737 System.arraycopy(args, 0, args2, 1, args.length);
738 args2[0] = inferenceContext.inferenceVars();
739 args = args2;
740 }
741 throw ex.setMessage(inferDiag ? diag.inferKey : diag.basicKey, args);
742 }
743
744 public MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict) {
745 return nilMethodCheck;
746 }
747 }
748
749 /**
750 * Arity-based method check. A method is applicable if the number of actuals
751 * supplied conforms to the method signature.
752 */
753 MethodCheck arityMethodCheck = new AbstractMethodCheck() {
754 @Override
755 void checkArg(boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
756 //do nothing - actual always compatible to formals
757 }
758 };
759
760 /**
761 * Main method applicability routine. Given a list of actual types A,
762 * a list of formal types F, determines whether the types in A are
763 * compatible (by method invocation conversion) with the types in F.
764 *
765 * Since this routine is shared between overload resolution and method
766 * type-inference, a (possibly empty) inference context is used to convert
767 * formal types to the corresponding 'undet' form ahead of a compatibility
768 * check so that constraints can be propagated and collected.
769 *
770 * Moreover, if one or more types in A is a deferred type, this routine uses
771 * DeferredAttr in order to perform deferred attribution. If one or more actual
772 * deferred types are stuck, they are placed in a queue and revisited later
773 * after the remainder of the arguments have been seen. If this is not sufficient
774 * to 'unstuck' the argument, a cyclic inference error is called out.
775 *
776 * A method check handler (see above) is used in order to report errors.
777 */
778 MethodCheck resolveMethodCheck = new AbstractMethodCheck() {
779
780 @Override
781 void checkArg(boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
782 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
783 mresult.check(null, actual);
784 }
785
786 @Override
787 public void argumentsAcceptable(final Env<AttrContext> env,
788 DeferredAttrContext deferredAttrContext,
789 List<Type> argtypes,
790 List<Type> formals,
791 Warner warn) {
792 super.argumentsAcceptable(env, deferredAttrContext, argtypes, formals, warn);
793 //should we expand formals?
794 if (deferredAttrContext.phase.isVarargsRequired()) {
795 //check varargs element type accessibility
796 varargsAccessible(env, types.elemtype(formals.last()),
797 deferredAttrContext.inferenceContext);
798 }
799 }
800
801 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) {
802 if (inferenceContext.free(t)) {
803 inferenceContext.addFreeTypeListener(List.of(t), new FreeTypeListener() {
804 @Override
805 public void typesInferred(InferenceContext inferenceContext) {
806 varargsAccessible(env, inferenceContext.asInstType(t), inferenceContext);
807 }
808 });
809 } else {
810 if (!isAccessible(env, t)) {
811 Symbol location = env.enclClass.sym;
812 reportMC(MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
813 }
814 }
815 }
816
817 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
818 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
819 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
820 MethodCheckDiag methodDiag = varargsCheck ?
821 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
822
823 @Override
824 public void report(DiagnosticPosition pos, JCDiagnostic details) {
825 reportMC(methodDiag, deferredAttrContext.inferenceContext, details);
826 }
827 };
828 return new MethodResultInfo(to, checkContext);
829 }
830
831 @Override
832 public MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict) {
833 return new MostSpecificCheck(strict, actuals);
834 }
835 };
836
837 /**
838 * Check context to be used during method applicability checks. A method check
839 * context might contain inference variables.
840 */
841 abstract class MethodCheckContext implements CheckContext {
842
843 boolean strict;
844 DeferredAttrContext deferredAttrContext;
845 Warner rsWarner;
846
847 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) {
848 this.strict = strict;
849 this.deferredAttrContext = deferredAttrContext;
850 this.rsWarner = rsWarner;
851 }
852
853 public boolean compatible(Type found, Type req, Warner warn) {
854 return strict ?
855 types.isSubtypeUnchecked(found, deferredAttrContext.inferenceContext.asFree(req), warn) :
856 types.isConvertible(found, deferredAttrContext.inferenceContext.asFree(req), warn);
857 }
858
859 public void report(DiagnosticPosition pos, JCDiagnostic details) {
860 throw inapplicableMethodException.setMessage(details);
861 }
862
863 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
864 return rsWarner;
865 }
866
867 public InferenceContext inferenceContext() {
868 return deferredAttrContext.inferenceContext;
869 }
870
871 public DeferredAttrContext deferredAttrContext() {
872 return deferredAttrContext;
873 }
874 }
875
876 /**
877 * ResultInfo class to be used during method applicability checks. Check
878 * for deferred types goes through special path.
879 */
880 class MethodResultInfo extends ResultInfo {
881
882 public MethodResultInfo(Type pt, CheckContext checkContext) {
883 attr.super(VAL, pt, checkContext);
884 }
885
886 @Override
887 protected Type check(DiagnosticPosition pos, Type found) {
888 if (found.hasTag(DEFERRED)) {
889 DeferredType dt = (DeferredType)found;
890 return dt.check(this);
891 } else {
892 return super.check(pos, chk.checkNonVoid(pos, types.capture(types.upperBound(found.baseType()))));
893 }
894 }
895
896 @Override
897 protected MethodResultInfo dup(Type newPt) {
898 return new MethodResultInfo(newPt, checkContext);
899 }
900
901 @Override
902 protected ResultInfo dup(CheckContext newContext) {
903 return new MethodResultInfo(pt, newContext);
904 }
905 }
906
907 /**
908 * Most specific method applicability routine. Given a list of actual types A,
909 * a list of formal types F1, and a list of formal types F2, the routine determines
910 * as to whether the types in F1 can be considered more specific than those in F2 w.r.t.
911 * argument types A.
912 */
913 class MostSpecificCheck implements MethodCheck {
914
915 boolean strict;
916 List<Type> actuals;
917
918 MostSpecificCheck(boolean strict, List<Type> actuals) {
919 this.strict = strict;
920 this.actuals = actuals;
921 }
922
923 @Override
924 public void argumentsAcceptable(final Env<AttrContext> env,
925 DeferredAttrContext deferredAttrContext,
926 List<Type> formals1,
927 List<Type> formals2,
928 Warner warn) {
929 formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired());
930 while (formals2.nonEmpty()) {
931 ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head);
932 mresult.check(null, formals1.head);
933 formals1 = formals1.tail;
934 formals2 = formals2.tail;
935 actuals = actuals.isEmpty() ? actuals : actuals.tail;
936 }
937 }
938
939 /**
940 * Create a method check context to be used during the most specific applicability check
941 */
942 ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext,
943 Warner rsWarner, Type actual) {
944 return attr.new ResultInfo(Kinds.VAL, to,
945 new MostSpecificCheckContext(strict, deferredAttrContext, rsWarner, actual));
946 }
947
948 /**
949 * Subclass of method check context class that implements most specific
950 * method conversion. If the actual type under analysis is a deferred type
951 * a full blown structural analysis is carried out.
952 */
953 class MostSpecificCheckContext extends MethodCheckContext {
954
955 Type actual;
956
957 public MostSpecificCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) {
958 super(strict, deferredAttrContext, rsWarner);
959 this.actual = actual;
960 }
961
962 public boolean compatible(Type found, Type req, Warner warn) {
963 if (!allowStructuralMostSpecific || actual == null) {
964 return super.compatible(found, req, warn);
965 } else {
966 switch (actual.getTag()) {
967 case DEFERRED:
968 DeferredType dt = (DeferredType) actual;
969 DeferredType.SpeculativeCache.Entry e = dt.speculativeCache.get(deferredAttrContext.msym, deferredAttrContext.phase);
970 return (e == null || e.speculativeTree == deferredAttr.stuckTree)
971 ? false : mostSpecific(found, req, e.speculativeTree, warn);
972 default:
973 return standaloneMostSpecific(found, req, actual, warn);
974 }
975 }
976 }
977
978 private boolean mostSpecific(Type t, Type s, JCTree tree, Warner warn) {
979 MostSpecificChecker msc = new MostSpecificChecker(t, s, warn);
980 msc.scan(tree);
981 return msc.result;
982 }
983
984 boolean polyMostSpecific(Type t1, Type t2, Warner warn) {
985 return (!t1.isPrimitive() && t2.isPrimitive())
986 ? true : super.compatible(t1, t2, warn);
987 }
988
989 boolean standaloneMostSpecific(Type t1, Type t2, Type exprType, Warner warn) {
990 return (exprType.isPrimitive() == t1.isPrimitive()
991 && exprType.isPrimitive() != t2.isPrimitive())
992 ? true : super.compatible(t1, t2, warn);
993 }
994
995 /**
996 * Structural checker for most specific.
997 */
998 class MostSpecificChecker extends DeferredAttr.PolyScanner {
999
1000 final Type t;
1001 final Type s;
1002 final Warner warn;
1003 boolean result;
1004
1005 MostSpecificChecker(Type t, Type s, Warner warn) {
1006 this.t = t;
1007 this.s = s;
1008 this.warn = warn;
1009 result = true;
1010 }
1011
1012 @Override
1013 void skip(JCTree tree) {
1014 result &= standaloneMostSpecific(t, s, tree.type, warn);
1015 }
1016
1017 @Override
1018 public void visitConditional(JCConditional tree) {
1019 if (tree.polyKind == PolyKind.STANDALONE) {
1020 result &= standaloneMostSpecific(t, s, tree.type, warn);
1021 } else {
1022 super.visitConditional(tree);
1023 }
1024 }
1025
1026 @Override
1027 public void visitApply(JCMethodInvocation tree) {
1028 result &= (tree.polyKind == PolyKind.STANDALONE)
1029 ? standaloneMostSpecific(t, s, tree.type, warn)
1030 : polyMostSpecific(t, s, warn);
1031 }
1032
1033 @Override
1034 public void visitNewClass(JCNewClass tree) {
1035 result &= (tree.polyKind == PolyKind.STANDALONE)
1036 ? standaloneMostSpecific(t, s, tree.type, warn)
1037 : polyMostSpecific(t, s, warn);
1038 }
1039
1040 @Override
1041 public void visitReference(JCMemberReference tree) {
1042 if (types.isFunctionalInterface(t.tsym) &&
1043 types.isFunctionalInterface(s.tsym) &&
1044 types.asSuper(t, s.tsym) == null &&
1045 types.asSuper(s, t.tsym) == null) {
1046 Type desc_t = types.findDescriptorType(t);
1047 Type desc_s = types.findDescriptorType(s);
1048 if (types.isSameTypes(desc_t.getParameterTypes(), desc_s.getParameterTypes())) {
1049 if (!desc_s.getReturnType().hasTag(VOID)) {
1050 //perform structural comparison
1051 Type ret_t = desc_t.getReturnType();
1052 Type ret_s = desc_s.getReturnType();
1053 result &= ((tree.refPolyKind == PolyKind.STANDALONE)
1054 ? standaloneMostSpecific(ret_t, ret_s, tree.sym.type.getReturnType(), warn)
1055 : polyMostSpecific(ret_t, ret_s, warn));
1056 } else {
1057 return;
1058 }
1059 } else {
1060 result &= false;
1061 }
1062 } else {
1063 result &= MostSpecificCheckContext.super.compatible(t, s, warn);
1064 }
1065 }
1066
1067 @Override
1068 public void visitLambda(JCLambda tree) {
1069 if (types.isFunctionalInterface(t.tsym) &&
1070 types.isFunctionalInterface(s.tsym) &&
1071 types.asSuper(t, s.tsym) == null &&
1072 types.asSuper(s, t.tsym) == null) {
1073 Type desc_t = types.findDescriptorType(t);
1074 Type desc_s = types.findDescriptorType(s);
1075 if (tree.paramKind == JCLambda.ParameterKind.EXPLICIT
1076 || types.isSameTypes(desc_t.getParameterTypes(), desc_s.getParameterTypes())) {
1077 if (!desc_s.getReturnType().hasTag(VOID)) {
1078 //perform structural comparison
1079 Type ret_t = desc_t.getReturnType();
1080 Type ret_s = desc_s.getReturnType();
1081 scanLambdaBody(tree, ret_t, ret_s);
1082 } else {
1083 return;
1084 }
1085 } else {
1086 result &= false;
1087 }
1088 } else {
1089 result &= MostSpecificCheckContext.super.compatible(t, s, warn);
1090 }
1091 }
1092 //where
1093
1094 void scanLambdaBody(JCLambda lambda, final Type t, final Type s) {
1095 if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) {
1096 result &= MostSpecificCheckContext.this.mostSpecific(t, s, lambda.body, warn);
1097 } else {
1098 DeferredAttr.LambdaReturnScanner lambdaScanner =
1099 new DeferredAttr.LambdaReturnScanner() {
1100 @Override
1101 public void visitReturn(JCReturn tree) {
1102 if (tree.expr != null) {
1103 result &= MostSpecificCheckContext.this.mostSpecific(t, s, tree.expr, warn);
1104 }
1105 }
1106 };
1107 lambdaScanner.scan(lambda.body);
1108 }
1109 }
1110 }
1111 }
1112
1113 public MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict) {
1114 Assert.error("Cannot get here!");
1115 return null;
1116 }
1117 }
1118
1119 public static class InapplicableMethodException extends RuntimeException {
1120 private static final long serialVersionUID = 0;
1121
1122 JCDiagnostic diagnostic;
1123 JCDiagnostic.Factory diags;
1124
1125 InapplicableMethodException(JCDiagnostic.Factory diags) {
1126 this.diagnostic = null;
1127 this.diags = diags;
1128 }
1129 InapplicableMethodException setMessage() {
1130 return setMessage((JCDiagnostic)null);
1131 }
1132 InapplicableMethodException setMessage(String key) {
1133 return setMessage(key != null ? diags.fragment(key) : null);
1134 }
1135 InapplicableMethodException setMessage(String key, Object... args) {
1136 return setMessage(key != null ? diags.fragment(key, args) : null);
1137 }
1138 InapplicableMethodException setMessage(JCDiagnostic diag) {
1139 this.diagnostic = diag;
1140 return this;
1141 }
1142
1143 public JCDiagnostic getDiagnostic() {
1144 return diagnostic;
1145 }
1146 }
1147 private final InapplicableMethodException inapplicableMethodException;
1148
1149 /* ***************************************************************************
1150 * Symbol lookup
1151 * the following naming conventions for arguments are used
1152 *
1153 * env is the environment where the symbol was mentioned
1154 * site is the type of which the symbol is a member
1155 * name is the symbol's name
1156 * if no arguments are given
1157 * argtypes are the value arguments, if we search for a method
1158 *
1159 * If no symbol was found, a ResolveError detailing the problem is returned.
1160 ****************************************************************************/
1161
1162 /** Find field. Synthetic fields are always skipped.
1163 * @param env The current environment.
1164 * @param site The original type from where the selection takes place.
1165 * @param name The name of the field.
1166 * @param c The class to search for the field. This is always
1167 * a superclass or implemented interface of site's class.
1168 */
1169 Symbol findField(Env<AttrContext> env,
1170 Type site,
1171 Name name,
1172 TypeSymbol c) {
1173 while (c.type.hasTag(TYPEVAR))
1174 c = c.type.getUpperBound().tsym;
1175 Symbol bestSoFar = varNotFound;
1176 Symbol sym;
1177 Scope.Entry e = c.members().lookup(name);
1178 while (e.scope != null) {
1179 if (e.sym.kind == VAR && (e.sym.flags_field & SYNTHETIC) == 0) {
1180 return isAccessible(env, site, e.sym)
1181 ? e.sym : new AccessError(env, site, e.sym);
1182 }
1183 e = e.next();
1184 }
1185 Type st = types.supertype(c.type);
1186 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) {
1187 sym = findField(env, site, name, st.tsym);
1188 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1189 }
1190 for (List<Type> l = types.interfaces(c.type);
1191 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1192 l = l.tail) {
1193 sym = findField(env, site, name, l.head.tsym);
1194 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1195 sym.owner != bestSoFar.owner)
1196 bestSoFar = new AmbiguityError(bestSoFar, sym);
1197 else if (sym.kind < bestSoFar.kind)
1198 bestSoFar = sym;
1199 }
1200 return bestSoFar;
1201 }
1202
1203 /** Resolve a field identifier, throw a fatal error if not found.
1204 * @param pos The position to use for error reporting.
1205 * @param env The environment current at the method invocation.
1206 * @param site The type of the qualifying expression, in which
1207 * identifier is searched.
1208 * @param name The identifier's name.
1209 */
1210 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
1211 Type site, Name name) {
1212 Symbol sym = findField(env, site, name, site.tsym);
1213 if (sym.kind == VAR) return (VarSymbol)sym;
1214 else throw new FatalError(
1215 diags.fragment("fatal.err.cant.locate.field",
1216 name));
1217 }
1218
1219 /** Find unqualified variable or field with given name.
1220 * Synthetic fields always skipped.
1221 * @param env The current environment.
1222 * @param name The name of the variable or field.
1223 */
1224 Symbol findVar(Env<AttrContext> env, Name name) {
1225 Symbol bestSoFar = varNotFound;
1226 Symbol sym;
1227 Env<AttrContext> env1 = env;
1228 boolean staticOnly = false;
1229 while (env1.outer != null) {
1230 if (isStatic(env1)) staticOnly = true;
1231 Scope.Entry e = env1.info.scope.lookup(name);
1232 while (e.scope != null &&
1233 (e.sym.kind != VAR ||
1234 (e.sym.flags_field & SYNTHETIC) != 0))
1235 e = e.next();
1236 sym = (e.scope != null)
1237 ? e.sym
1238 : findField(
1239 env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
1240 if (sym.exists()) {
1241 if (staticOnly &&
1242 sym.kind == VAR &&
1243 sym.owner.kind == TYP &&
1244 (sym.flags() & STATIC) == 0)
1245 return new StaticError(sym);
1246 else
1247 return sym;
1248 } else if (sym.kind < bestSoFar.kind) {
1249 bestSoFar = sym;
1250 }
1251
1252 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1253 env1 = env1.outer;
1254 }
1255
1256 sym = findField(env, syms.predefClass.type, name, syms.predefClass);
1257 if (sym.exists())
1258 return sym;
1259 if (bestSoFar.exists())
1260 return bestSoFar;
1261
1262 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
1263 for (; e.scope != null; e = e.next()) {
1264 sym = e.sym;
1265 Type origin = e.getOrigin().owner.type;
1266 if (sym.kind == VAR) {
1267 if (e.sym.owner.type != origin)
1268 sym = sym.clone(e.getOrigin().owner);
1269 return isAccessible(env, origin, sym)
1270 ? sym : new AccessError(env, origin, sym);
1271 }
1272 }
1273
1274 Symbol origin = null;
1275 e = env.toplevel.starImportScope.lookup(name);
1276 for (; e.scope != null; e = e.next()) {
1277 sym = e.sym;
1278 if (sym.kind != VAR)
1279 continue;
1280 // invariant: sym.kind == VAR
1281 if (bestSoFar.kind < AMBIGUOUS && sym.owner != bestSoFar.owner)
1282 return new AmbiguityError(bestSoFar, sym);
1283 else if (bestSoFar.kind >= VAR) {
1284 origin = e.getOrigin().owner;
1285 bestSoFar = isAccessible(env, origin.type, sym)
1286 ? sym : new AccessError(env, origin.type, sym);
1287 }
1288 }
1289 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
1290 return bestSoFar.clone(origin);
1291 else
1292 return bestSoFar;
1293 }
1294
1295 Warner noteWarner = new Warner();
1296
1297 /** Select the best method for a call site among two choices.
1298 * @param env The current environment.
1299 * @param site The original type from where the
1300 * selection takes place.
1301 * @param argtypes The invocation's value arguments,
1302 * @param typeargtypes The invocation's type arguments,
1303 * @param sym Proposed new best match.
1304 * @param bestSoFar Previously found best match.
1305 * @param allowBoxing Allow boxing conversions of arguments.
1306 * @param useVarargs Box trailing arguments into an array for varargs.
1307 */
1308 @SuppressWarnings("fallthrough")
1309 Symbol selectBest(Env<AttrContext> env,
1310 Type site,
1311 List<Type> argtypes,
1312 List<Type> typeargtypes,
1313 Symbol sym,
1314 Symbol bestSoFar,
1315 boolean allowBoxing,
1316 boolean useVarargs,
1317 boolean operator) {
1318 if (sym.kind == ERR ||
1319 !sym.isInheritedIn(site.tsym, types)) {
1320 return bestSoFar;
1321 } else if (useVarargs && (sym.flags() & VARARGS) == 0) {
1322 return bestSoFar.kind >= ERRONEOUS ?
1323 new BadVarargsMethod((ResolveError)bestSoFar) :
1324 bestSoFar;
1325 }
1326 Assert.check(sym.kind < AMBIGUOUS);
1327 try {
1328 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes,
1329 allowBoxing, useVarargs, types.noWarnings);
1330 if (!operator)
1331 currentResolutionContext.addApplicableCandidate(sym, mt);
1332 } catch (InapplicableMethodException ex) {
1333 if (!operator)
1334 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic());
1335 switch (bestSoFar.kind) {
1336 case ABSENT_MTH:
1337 return new InapplicableSymbolError(currentResolutionContext);
1338 case WRONG_MTH:
1339 if (operator) return bestSoFar;
1340 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1341 default:
1342 return bestSoFar;
1343 }
1344 }
1345 if (!isAccessible(env, site, sym)) {
1346 return (bestSoFar.kind == ABSENT_MTH)
1347 ? new AccessError(env, site, sym)
1348 : bestSoFar;
1349 }
1350 return (bestSoFar.kind > AMBIGUOUS)
1351 ? sym
1352 : mostSpecific(argtypes, sym, bestSoFar, env, site,
1353 allowBoxing && operator, useVarargs);
1354 }
1355
1356 /* Return the most specific of the two methods for a call,
1357 * given that both are accessible and applicable.
1358 * @param m1 A new candidate for most specific.
1359 * @param m2 The previous most specific candidate.
1360 * @param env The current environment.
1361 * @param site The original type from where the selection
1362 * takes place.
1363 * @param allowBoxing Allow boxing conversions of arguments.
1364 * @param useVarargs Box trailing arguments into an array for varargs.
1365 */
1366 Symbol mostSpecific(List<Type> argtypes, Symbol m1,
1367 Symbol m2,
1368 Env<AttrContext> env,
1369 final Type site,
1370 boolean allowBoxing,
1371 boolean useVarargs) {
1372 switch (m2.kind) {
1373 case MTH:
1374 if (m1 == m2) return m1;
1375 boolean m1SignatureMoreSpecific =
1376 signatureMoreSpecific(argtypes, env, site, m1, m2, allowBoxing, useVarargs);
1377 boolean m2SignatureMoreSpecific =
1378 signatureMoreSpecific(argtypes, env, site, m2, m1, allowBoxing, useVarargs);
1379 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
1380 Type mt1 = types.memberType(site, m1);
1381 Type mt2 = types.memberType(site, m2);
1382 if (!types.overrideEquivalent(mt1, mt2))
1383 return ambiguityError(m1, m2);
1384
1385 // same signature; select (a) the non-bridge method, or
1386 // (b) the one that overrides the other, or (c) the concrete
1387 // one, or (d) merge both abstract signatures
1388 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
1389 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
1390
1391 // if one overrides or hides the other, use it
1392 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
1393 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
1394 if (types.asSuper(m1Owner.type, m2Owner) != null &&
1395 ((m1.owner.flags_field & INTERFACE) == 0 ||
1396 (m2.owner.flags_field & INTERFACE) != 0) &&
1397 m1.overrides(m2, m1Owner, types, false))
1398 return m1;
1399 if (types.asSuper(m2Owner.type, m1Owner) != null &&
1400 ((m2.owner.flags_field & INTERFACE) == 0 ||
1401 (m1.owner.flags_field & INTERFACE) != 0) &&
1402 m2.overrides(m1, m2Owner, types, false))
1403 return m2;
1404 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
1405 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
1406 if (m1Abstract && !m2Abstract) return m2;
1407 if (m2Abstract && !m1Abstract) return m1;
1408 // both abstract or both concrete
1409 return ambiguityError(m1, m2);
1410 }
1411 if (m1SignatureMoreSpecific) return m1;
1412 if (m2SignatureMoreSpecific) return m2;
1413 return ambiguityError(m1, m2);
1414 case AMBIGUOUS:
1415 //check if m1 is more specific than all ambiguous methods in m2
1416 AmbiguityError e = (AmbiguityError)m2;
1417 for (Symbol s : e.ambiguousSyms) {
1418 if (mostSpecific(argtypes, m1, s, env, site, allowBoxing, useVarargs) != m1) {
1419 return e.addAmbiguousSymbol(m1);
1420 }
1421 }
1422 return m1;
1423 default:
1424 throw new AssertionError();
1425 }
1426 }
1427 //where
1428 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean allowBoxing, boolean useVarargs) {
1429 noteWarner.clear();
1430 int maxLength = Math.max(
1431 Math.max(m1.type.getParameterTypes().length(), actuals.length()),
1432 m2.type.getParameterTypes().length());
1433 MethodResolutionContext prevResolutionContext = currentResolutionContext;
1434 try {
1435 currentResolutionContext = new MethodResolutionContext();
1436 currentResolutionContext.step = prevResolutionContext.step;
1437 currentResolutionContext.methodCheck =
1438 prevResolutionContext.methodCheck.mostSpecificCheck(actuals, !allowBoxing);
1439 Type mst = instantiate(env, site, m2, null,
1440 adjustArgs(types.lowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null,
1441 allowBoxing, useVarargs, noteWarner);
1442 return mst != null &&
1443 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
1444 } finally {
1445 currentResolutionContext = prevResolutionContext;
1446 }
1447 }
1448 private List<Type> adjustArgs(List<Type> args, Symbol msym, int length, boolean allowVarargs) {
1449 if ((msym.flags() & VARARGS) != 0 && allowVarargs) {
1450 Type varargsElem = types.elemtype(args.last());
1451 if (varargsElem == null) {
1452 Assert.error("Bad varargs = " + args.last() + " " + msym);
1453 }
1454 List<Type> newArgs = args.reverse().tail.prepend(varargsElem).reverse();
1455 while (newArgs.length() < length) {
1456 newArgs = newArgs.append(newArgs.last());
1457 }
1458 return newArgs;
1459 } else {
1460 return args;
1461 }
1462 }
1463 //where
1464 Type mostSpecificReturnType(Type mt1, Type mt2) {
1465 Type rt1 = mt1.getReturnType();
1466 Type rt2 = mt2.getReturnType();
1467
1468 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL)) {
1469 //if both are generic methods, adjust return type ahead of subtyping check
1470 rt1 = types.subst(rt1, mt1.getTypeArguments(), mt2.getTypeArguments());
1471 }
1472 //first use subtyping, then return type substitutability
1473 if (types.isSubtype(rt1, rt2)) {
1474 return mt1;
1475 } else if (types.isSubtype(rt2, rt1)) {
1476 return mt2;
1477 } else if (types.returnTypeSubstitutable(mt1, mt2)) {
1478 return mt1;
1479 } else if (types.returnTypeSubstitutable(mt2, mt1)) {
1480 return mt2;
1481 } else {
1482 return null;
1483 }
1484 }
1485 //where
1486 Symbol ambiguityError(Symbol m1, Symbol m2) {
1487 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
1488 return (m1.flags() & CLASH) == 0 ? m1 : m2;
1489 } else {
1490 return new AmbiguityError(m1, m2);
1491 }
1492 }
1493
1494 Symbol findMethodInScope(Env<AttrContext> env,
1495 Type site,
1496 Name name,
1497 List<Type> argtypes,
1498 List<Type> typeargtypes,
1499 Scope sc,
1500 Symbol bestSoFar,
1501 boolean allowBoxing,
1502 boolean useVarargs,
1503 boolean operator,
1504 boolean abstractok) {
1505 for (Symbol s : sc.getElementsByName(name, new LookupFilter(abstractok))) {
1506 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s,
1507 bestSoFar, allowBoxing, useVarargs, operator);
1508 }
1509 return bestSoFar;
1510 }
1511 //where
1512 class LookupFilter implements Filter<Symbol> {
1513
1514 boolean abstractOk;
1515
1516 LookupFilter(boolean abstractOk) {
1517 this.abstractOk = abstractOk;
1518 }
1519
1520 public boolean accepts(Symbol s) {
1521 long flags = s.flags();
1522 return s.kind == MTH &&
1523 (flags & SYNTHETIC) == 0 &&
1524 (abstractOk ||
1525 (flags & DEFAULT) != 0 ||
1526 (flags & ABSTRACT) == 0);
1527 }
1528 };
1529
1530 /** Find best qualified method matching given name, type and value
1531 * arguments.
1532 * @param env The current environment.
1533 * @param site The original type from where the selection
1534 * takes place.
1535 * @param name The method's name.
1536 * @param argtypes The method's value arguments.
1537 * @param typeargtypes The method's type arguments
1538 * @param allowBoxing Allow boxing conversions of arguments.
1539 * @param useVarargs Box trailing arguments into an array for varargs.
1540 */
1541 Symbol findMethod(Env<AttrContext> env,
1542 Type site,
1543 Name name,
1544 List<Type> argtypes,
1545 List<Type> typeargtypes,
1546 boolean allowBoxing,
1547 boolean useVarargs,
1548 boolean operator) {
1549 Symbol bestSoFar = methodNotFound;
1550 bestSoFar = findMethod(env,
1551 site,
1552 name,
1553 argtypes,
1554 typeargtypes,
1555 site.tsym.type,
1556 bestSoFar,
1557 allowBoxing,
1558 useVarargs,
1559 operator);
1560 reportVerboseResolutionDiagnostic(env.tree.pos(), name, site, argtypes, typeargtypes, bestSoFar);
1561 return bestSoFar;
1562 }
1563 // where
1564 private Symbol findMethod(Env<AttrContext> env,
1565 Type site,
1566 Name name,
1567 List<Type> argtypes,
1568 List<Type> typeargtypes,
1569 Type intype,
1570 Symbol bestSoFar,
1571 boolean allowBoxing,
1572 boolean useVarargs,
1573 boolean operator) {
1574 @SuppressWarnings({"unchecked","rawtypes"})
1575 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() };
1576 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK;
1577 for (TypeSymbol s : superclasses(intype)) {
1578 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1579 s.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1580 if (name == names.init) return bestSoFar;
1581 iphase = (iphase == null) ? null : iphase.update(s, this);
1582 if (iphase != null) {
1583 for (Type itype : types.interfaces(s.type)) {
1584 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]);
1585 }
1586 }
1587 }
1588
1589 Symbol concrete = bestSoFar.kind < ERR &&
1590 (bestSoFar.flags() & ABSTRACT) == 0 ?
1591 bestSoFar : methodNotFound;
1592
1593 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) {
1594 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK && !allowDefaultMethods) break;
1595 //keep searching for abstract methods
1596 for (Type itype : itypes[iphase2.ordinal()]) {
1597 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure())
1598 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK &&
1599 (itype.tsym.flags() & DEFAULT) == 0) continue;
1600 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1601 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1602 if (concrete != bestSoFar &&
1603 concrete.kind < ERR && bestSoFar.kind < ERR &&
1604 types.isSubSignature(concrete.type, bestSoFar.type)) {
1605 //this is an hack - as javac does not do full membership checks
1606 //most specific ends up comparing abstract methods that might have
1607 //been implemented by some concrete method in a subclass and,
1608 //because of raw override, it is possible for an abstract method
1609 //to be more specific than the concrete method - so we need
1610 //to explicitly call that out (see CR 6178365)
1611 bestSoFar = concrete;
1612 }
1613 }
1614 }
1615 return bestSoFar;
1616 }
1617
1618 enum InterfaceLookupPhase {
1619 ABSTRACT_OK() {
1620 @Override
1621 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1622 //We should not look for abstract methods if receiver is a concrete class
1623 //(as concrete classes are expected to implement all abstracts coming
1624 //from superinterfaces)
1625 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) {
1626 return this;
1627 } else if (rs.allowDefaultMethods) {
1628 return DEFAULT_OK;
1629 } else {
1630 return null;
1631 }
1632 }
1633 },
1634 DEFAULT_OK() {
1635 @Override
1636 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1637 return this;
1638 }
1639 };
1640
1641 abstract InterfaceLookupPhase update(Symbol s, Resolve rs);
1642 }
1643
1644 /**
1645 * Return an Iterable object to scan the superclasses of a given type.
1646 * It's crucial that the scan is done lazily, as we don't want to accidentally
1647 * access more supertypes than strictly needed (as this could trigger completion
1648 * errors if some of the not-needed supertypes are missing/ill-formed).
1649 */
1650 Iterable<TypeSymbol> superclasses(final Type intype) {
1651 return new Iterable<TypeSymbol>() {
1652 public Iterator<TypeSymbol> iterator() {
1653 return new Iterator<TypeSymbol>() {
1654
1655 List<TypeSymbol> seen = List.nil();
1656 TypeSymbol currentSym = symbolFor(intype);
1657 TypeSymbol prevSym = null;
1658
1659 public boolean hasNext() {
1660 if (currentSym == syms.noSymbol) {
1661 currentSym = symbolFor(types.supertype(prevSym.type));
1662 }
1663 return currentSym != null;
1664 }
1665
1666 public TypeSymbol next() {
1667 prevSym = currentSym;
1668 currentSym = syms.noSymbol;
1669 Assert.check(prevSym != null || prevSym != syms.noSymbol);
1670 return prevSym;
1671 }
1672
1673 public void remove() {
1674 throw new UnsupportedOperationException();
1675 }
1676
1677 TypeSymbol symbolFor(Type t) {
1678 if (!t.hasTag(CLASS) &&
1679 !t.hasTag(TYPEVAR)) {
1680 return null;
1681 }
1682 while (t.hasTag(TYPEVAR))
1683 t = t.getUpperBound();
1684 if (seen.contains(t.tsym)) {
1685 //degenerate case in which we have a circular
1686 //class hierarchy - because of ill-formed classfiles
1687 return null;
1688 }
1689 seen = seen.prepend(t.tsym);
1690 return t.tsym;
1691 }
1692 };
1693 }
1694 };
1695 }
1696
1697 /** Find unqualified method matching given name, type and value arguments.
1698 * @param env The current environment.
1699 * @param name The method's name.
1700 * @param argtypes The method's value arguments.
1701 * @param typeargtypes The method's type arguments.
1702 * @param allowBoxing Allow boxing conversions of arguments.
1703 * @param useVarargs Box trailing arguments into an array for varargs.
1704 */
1705 Symbol findFun(Env<AttrContext> env, Name name,
1706 List<Type> argtypes, List<Type> typeargtypes,
1707 boolean allowBoxing, boolean useVarargs) {
1708 Symbol bestSoFar = methodNotFound;
1709 Symbol sym;
1710 Env<AttrContext> env1 = env;
1711 boolean staticOnly = false;
1712 while (env1.outer != null) {
1713 if (isStatic(env1)) staticOnly = true;
1714 sym = findMethod(
1715 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
1716 allowBoxing, useVarargs, false);
1717 if (sym.exists()) {
1718 if (staticOnly &&
1719 sym.kind == MTH &&
1720 sym.owner.kind == TYP &&
1721 (sym.flags() & STATIC) == 0) return new StaticError(sym);
1722 else return sym;
1723 } else if (sym.kind < bestSoFar.kind) {
1724 bestSoFar = sym;
1725 }
1726 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1727 env1 = env1.outer;
1728 }
1729
1730 sym = findMethod(env, syms.predefClass.type, name, argtypes,
1731 typeargtypes, allowBoxing, useVarargs, false);
1732 if (sym.exists())
1733 return sym;
1734
1735 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
1736 for (; e.scope != null; e = e.next()) {
1737 sym = e.sym;
1738 Type origin = e.getOrigin().owner.type;
1739 if (sym.kind == MTH) {
1740 if (e.sym.owner.type != origin)
1741 sym = sym.clone(e.getOrigin().owner);
1742 if (!isAccessible(env, origin, sym))
1743 sym = new AccessError(env, origin, sym);
1744 bestSoFar = selectBest(env, origin,
1745 argtypes, typeargtypes,
1746 sym, bestSoFar,
1747 allowBoxing, useVarargs, false);
1748 }
1749 }
1750 if (bestSoFar.exists())
1751 return bestSoFar;
1752
1753 e = env.toplevel.starImportScope.lookup(name);
1754 for (; e.scope != null; e = e.next()) {
1755 sym = e.sym;
1756 Type origin = e.getOrigin().owner.type;
1757 if (sym.kind == MTH) {
1758 if (e.sym.owner.type != origin)
1759 sym = sym.clone(e.getOrigin().owner);
1760 if (!isAccessible(env, origin, sym))
1761 sym = new AccessError(env, origin, sym);
1762 bestSoFar = selectBest(env, origin,
1763 argtypes, typeargtypes,
1764 sym, bestSoFar,
1765 allowBoxing, useVarargs, false);
1766 }
1767 }
1768 return bestSoFar;
1769 }
1770
1771 /** Load toplevel or member class with given fully qualified name and
1772 * verify that it is accessible.
1773 * @param env The current environment.
1774 * @param name The fully qualified name of the class to be loaded.
1775 */
1776 Symbol loadClass(Env<AttrContext> env, Name name) {
1777 try {
1778 ClassSymbol c = reader.loadClass(name);
1779 return isAccessible(env, c) ? c : new AccessError(c);
1780 } catch (ClassReader.BadClassFile err) {
1781 throw err;
1782 } catch (CompletionFailure ex) {
1783 return typeNotFound;
1784 }
1785 }
1786
1787 /** Find qualified member type.
1788 * @param env The current environment.
1789 * @param site The original type from where the selection takes
1790 * place.
1791 * @param name The type's name.
1792 * @param c The class to search for the member type. This is
1793 * always a superclass or implemented interface of
1794 * site's class.
1795 */
1796 Symbol findMemberType(Env<AttrContext> env,
1797 Type site,
1798 Name name,
1799 TypeSymbol c) {
1800 Symbol bestSoFar = typeNotFound;
1801 Symbol sym;
1802 Scope.Entry e = c.members().lookup(name);
1803 while (e.scope != null) {
1804 if (e.sym.kind == TYP) {
1805 return isAccessible(env, site, e.sym)
1806 ? e.sym
1807 : new AccessError(env, site, e.sym);
1808 }
1809 e = e.next();
1810 }
1811 Type st = types.supertype(c.type);
1812 if (st != null && st.hasTag(CLASS)) {
1813 sym = findMemberType(env, site, name, st.tsym);
1814 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1815 }
1816 for (List<Type> l = types.interfaces(c.type);
1817 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1818 l = l.tail) {
1819 sym = findMemberType(env, site, name, l.head.tsym);
1820 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1821 sym.owner != bestSoFar.owner)
1822 bestSoFar = new AmbiguityError(bestSoFar, sym);
1823 else if (sym.kind < bestSoFar.kind)
1824 bestSoFar = sym;
1825 }
1826 return bestSoFar;
1827 }
1828
1829 /** Find a global type in given scope and load corresponding class.
1830 * @param env The current environment.
1831 * @param scope The scope in which to look for the type.
1832 * @param name The type's name.
1833 */
1834 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) {
1835 Symbol bestSoFar = typeNotFound;
1836 for (Scope.Entry e = scope.lookup(name); e.scope != null; e = e.next()) {
1837 Symbol sym = loadClass(env, e.sym.flatName());
1838 if (bestSoFar.kind == TYP && sym.kind == TYP &&
1839 bestSoFar != sym)
1840 return new AmbiguityError(bestSoFar, sym);
1841 else if (sym.kind < bestSoFar.kind)
1842 bestSoFar = sym;
1843 }
1844 return bestSoFar;
1845 }
1846
1847 /** Find an unqualified type symbol.
1848 * @param env The current environment.
1849 * @param name The type's name.
1850 */
1851 Symbol findType(Env<AttrContext> env, Name name) {
1852 Symbol bestSoFar = typeNotFound;
1853 Symbol sym;
1854 boolean staticOnly = false;
1855 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
1856 if (isStatic(env1)) staticOnly = true;
1857 for (Scope.Entry e = env1.info.scope.lookup(name);
1858 e.scope != null;
1859 e = e.next()) {
1860 if (e.sym.kind == TYP) {
1861 if (staticOnly &&
1862 e.sym.type.hasTag(TYPEVAR) &&
1863 e.sym.owner.kind == TYP) return new StaticError(e.sym);
1864 return e.sym;
1865 }
1866 }
1867
1868 sym = findMemberType(env1, env1.enclClass.sym.type, name,
1869 env1.enclClass.sym);
1870 if (staticOnly && sym.kind == TYP &&
1871 sym.type.hasTag(CLASS) &&
1872 sym.type.getEnclosingType().hasTag(CLASS) &&
1873 env1.enclClass.sym.type.isParameterized() &&
1874 sym.type.getEnclosingType().isParameterized())
1875 return new StaticError(sym);
1876 else if (sym.exists()) return sym;
1877 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1878
1879 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
1880 if ((encl.sym.flags() & STATIC) != 0)
1881 staticOnly = true;
1882 }
1883
1884 if (!env.tree.hasTag(IMPORT)) {
1885 sym = findGlobalType(env, env.toplevel.namedImportScope, name);
1886 if (sym.exists()) return sym;
1887 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1888
1889 sym = findGlobalType(env, env.toplevel.packge.members(), name);
1890 if (sym.exists()) return sym;
1891 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1892
1893 sym = findGlobalType(env, env.toplevel.starImportScope, name);
1894 if (sym.exists()) return sym;
1895 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1896 }
1897
1898 return bestSoFar;
1899 }
1900
1901 /** Find an unqualified identifier which matches a specified kind set.
1902 * @param env The current environment.
1903 * @param name The identifier's name.
1904 * @param kind Indicates the possible symbol kinds
1905 * (a subset of VAL, TYP, PCK).
1906 */
1907 Symbol findIdent(Env<AttrContext> env, Name name, int kind) {
1908 Symbol bestSoFar = typeNotFound;
1909 Symbol sym;
1910
1911 if ((kind & VAR) != 0) {
1912 sym = findVar(env, name);
1913 if (sym.exists()) return sym;
1914 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1915 }
1916
1917 if ((kind & TYP) != 0) {
1918 sym = findType(env, name);
1919 if (sym.kind==TYP) {
1920 reportDependence(env.enclClass.sym, sym);
1921 }
1922 if (sym.exists()) return sym;
1923 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1924 }
1925
1926 if ((kind & PCK) != 0) return reader.enterPackage(name);
1927 else return bestSoFar;
1928 }
1929
1930 /** Report dependencies.
1931 * @param from The enclosing class sym
1932 * @param to The found identifier that the class depends on.
1933 */
1934 public void reportDependence(Symbol from, Symbol to) {
1935 // Override if you want to collect the reported dependencies.
1936 }
1937
1938 /** Find an identifier in a package which matches a specified kind set.
1939 * @param env The current environment.
1940 * @param name The identifier's name.
1941 * @param kind Indicates the possible symbol kinds
1942 * (a nonempty subset of TYP, PCK).
1943 */
1944 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
1945 Name name, int kind) {
1946 Name fullname = TypeSymbol.formFullName(name, pck);
1947 Symbol bestSoFar = typeNotFound;
1948 PackageSymbol pack = null;
1949 if ((kind & PCK) != 0) {
1950 pack = reader.enterPackage(fullname);
1951 if (pack.exists()) return pack;
1952 }
1953 if ((kind & TYP) != 0) {
1954 Symbol sym = loadClass(env, fullname);
1955 if (sym.exists()) {
1956 // don't allow programs to use flatnames
1957 if (name == sym.name) return sym;
1958 }
1959 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1960 }
1961 return (pack != null) ? pack : bestSoFar;
1962 }
1963
1964 /** Find an identifier among the members of a given type `site'.
1965 * @param env The current environment.
1966 * @param site The type containing the symbol to be found.
1967 * @param name The identifier's name.
1968 * @param kind Indicates the possible symbol kinds
1969 * (a subset of VAL, TYP).
1970 */
1971 Symbol findIdentInType(Env<AttrContext> env, Type site,
1972 Name name, int kind) {
1973 Symbol bestSoFar = typeNotFound;
1974 Symbol sym;
1975 if ((kind & VAR) != 0) {
1976 sym = findField(env, site, name, site.tsym);
1977 if (sym.exists()) return sym;
1978 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1979 }
1980
1981 if ((kind & TYP) != 0) {
1982 sym = findMemberType(env, site, name, site.tsym);
1983 if (sym.exists()) return sym;
1984 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1985 }
1986 return bestSoFar;
1987 }
1988
1989 /* ***************************************************************************
1990 * Access checking
1991 * The following methods convert ResolveErrors to ErrorSymbols, issuing
1992 * an error message in the process
1993 ****************************************************************************/
1994
1995 /** If `sym' is a bad symbol: report error and return errSymbol
1996 * else pass through unchanged,
1997 * additional arguments duplicate what has been used in trying to find the
1998 * symbol {@literal (--> flyweight pattern)}. This improves performance since we
1999 * expect misses to happen frequently.
2000 *
2001 * @param sym The symbol that was found, or a ResolveError.
2002 * @param pos The position to use for error reporting.
2003 * @param location The symbol the served as a context for this lookup
2004 * @param site The original type from where the selection took place.
2005 * @param name The symbol's name.
2006 * @param qualified Did we get here through a qualified expression resolution?
2007 * @param argtypes The invocation's value arguments,
2008 * if we looked for a method.
2009 * @param typeargtypes The invocation's type arguments,
2010 * if we looked for a method.
2011 * @param logResolveHelper helper class used to log resolve errors
2012 */
2013 Symbol accessInternal(Symbol sym,
2014 DiagnosticPosition pos,
2015 Symbol location,
2016 Type site,
2017 Name name,
2018 boolean qualified,
2019 List<Type> argtypes,
2020 List<Type> typeargtypes,
2021 LogResolveHelper logResolveHelper) {
2022 if (sym.kind >= AMBIGUOUS) {
2023 ResolveError errSym = (ResolveError)sym;
2024 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
2025 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes);
2026 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) {
2027 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
2028 }
2029 }
2030 return sym;
2031 }
2032
2033 /**
2034 * Variant of the generalized access routine, to be used for generating method
2035 * resolution diagnostics
2036 */
2037 Symbol accessMethod(Symbol sym,
2038 DiagnosticPosition pos,
2039 Symbol location,
2040 Type site,
2041 Name name,
2042 boolean qualified,
2043 List<Type> argtypes,
2044 List<Type> typeargtypes) {
2045 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper);
2046 }
2047
2048 /** Same as original accessMethod(), but without location.
2049 */
2050 Symbol accessMethod(Symbol sym,
2051 DiagnosticPosition pos,
2052 Type site,
2053 Name name,
2054 boolean qualified,
2055 List<Type> argtypes,
2056 List<Type> typeargtypes) {
2057 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
2058 }
2059
2060 /**
2061 * Variant of the generalized access routine, to be used for generating variable,
2062 * type resolution diagnostics
2063 */
2064 Symbol accessBase(Symbol sym,
2065 DiagnosticPosition pos,
2066 Symbol location,
2067 Type site,
2068 Name name,
2069 boolean qualified) {
2070 return accessInternal(sym, pos, location, site, name, qualified, List.<Type>nil(), null, basicLogResolveHelper);
2071 }
2072
2073 /** Same as original accessBase(), but without location.
2074 */
2075 Symbol accessBase(Symbol sym,
2076 DiagnosticPosition pos,
2077 Type site,
2078 Name name,
2079 boolean qualified) {
2080 return accessBase(sym, pos, site.tsym, site, name, qualified);
2081 }
2082
2083 interface LogResolveHelper {
2084 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes);
2085 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes);
2086 }
2087
2088 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() {
2089 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2090 return !site.isErroneous();
2091 }
2092 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2093 return argtypes;
2094 }
2095 };
2096
2097 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() {
2098 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2099 return !site.isErroneous() &&
2100 !Type.isErroneous(argtypes) &&
2101 (typeargtypes == null || !Type.isErroneous(typeargtypes));
2102 }
2103 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2104 return (syms.operatorNames.contains(name)) ?
2105 argtypes :
2106 Type.map(argtypes, new ResolveDeferredRecoveryMap(accessedSym));
2107 }
2108
2109 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap {
2110
2111 public ResolveDeferredRecoveryMap(Symbol msym) {
2112 deferredAttr.super(AttrMode.SPECULATIVE, msym, currentResolutionContext.step);
2113 }
2114
2115 @Override
2116 protected Type typeOf(DeferredType dt) {
2117 Type res = super.typeOf(dt);
2118 if (!res.isErroneous()) {
2119 switch (TreeInfo.skipParens(dt.tree).getTag()) {
2120 case LAMBDA:
2121 case REFERENCE:
2122 return dt;
2123 case CONDEXPR:
2124 return res == Type.recoveryType ?
2125 dt : res;
2126 }
2127 }
2128 return res;
2129 }
2130 }
2131 };
2132
2133 /** Check that sym is not an abstract method.
2134 */
2135 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
2136 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0)
2137 log.error(pos, "abstract.cant.be.accessed.directly",
2138 kindName(sym), sym, sym.location());
2139 }
2140
2141 /* ***************************************************************************
2142 * Debugging
2143 ****************************************************************************/
2144
2145 /** print all scopes starting with scope s and proceeding outwards.
2146 * used for debugging.
2147 */
2148 public void printscopes(Scope s) {
2149 while (s != null) {
2150 if (s.owner != null)
2151 System.err.print(s.owner + ": ");
2152 for (Scope.Entry e = s.elems; e != null; e = e.sibling) {
2153 if ((e.sym.flags() & ABSTRACT) != 0)
2154 System.err.print("abstract ");
2155 System.err.print(e.sym + " ");
2156 }
2157 System.err.println();
2158 s = s.next;
2159 }
2160 }
2161
2162 void printscopes(Env<AttrContext> env) {
2163 while (env.outer != null) {
2164 System.err.println("------------------------------");
2165 printscopes(env.info.scope);
2166 env = env.outer;
2167 }
2168 }
2169
2170 public void printscopes(Type t) {
2171 while (t.hasTag(CLASS)) {
2172 printscopes(t.tsym.members());
2173 t = types.supertype(t);
2174 }
2175 }
2176
2177 /* ***************************************************************************
2178 * Name resolution
2179 * Naming conventions are as for symbol lookup
2180 * Unlike the find... methods these methods will report access errors
2181 ****************************************************************************/
2182
2183 /** Resolve an unqualified (non-method) identifier.
2184 * @param pos The position to use for error reporting.
2185 * @param env The environment current at the identifier use.
2186 * @param name The identifier's name.
2187 * @param kind The set of admissible symbol kinds for the identifier.
2188 */
2189 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
2190 Name name, int kind) {
2191 return accessBase(
2192 findIdent(env, name, kind),
2193 pos, env.enclClass.sym.type, name, false);
2194 }
2195
2196 /** Resolve an unqualified method identifier.
2197 * @param pos The position to use for error reporting.
2198 * @param env The environment current at the method invocation.
2199 * @param name The identifier's name.
2200 * @param argtypes The types of the invocation's value arguments.
2201 * @param typeargtypes The types of the invocation's type arguments.
2202 */
2203 Symbol resolveMethod(DiagnosticPosition pos,
2204 Env<AttrContext> env,
2205 Name name,
2206 List<Type> argtypes,
2207 List<Type> typeargtypes) {
2208 return lookupMethod(env, pos, env.enclClass.sym, resolveMethodCheck,
2209 new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) {
2210 @Override
2211 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2212 return findFun(env, name, argtypes, typeargtypes,
2213 phase.isBoxingRequired(),
2214 phase.isVarargsRequired());
2215 }});
2216 }
2217
2218 /** Resolve a qualified method identifier
2219 * @param pos The position to use for error reporting.
2220 * @param env The environment current at the method invocation.
2221 * @param site The type of the qualifying expression, in which
2222 * identifier is searched.
2223 * @param name The identifier's name.
2224 * @param argtypes The types of the invocation's value arguments.
2225 * @param typeargtypes The types of the invocation's type arguments.
2226 */
2227 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2228 Type site, Name name, List<Type> argtypes,
2229 List<Type> typeargtypes) {
2230 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
2231 }
2232 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2233 Symbol location, Type site, Name name, List<Type> argtypes,
2234 List<Type> typeargtypes) {
2235 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
2236 }
2237 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
2238 DiagnosticPosition pos, Env<AttrContext> env,
2239 Symbol location, Type site, Name name, List<Type> argtypes,
2240 List<Type> typeargtypes) {
2241 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) {
2242 @Override
2243 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2244 return findMethod(env, site, name, argtypes, typeargtypes,
2245 phase.isBoxingRequired(),
2246 phase.isVarargsRequired(), false);
2247 }
2248 @Override
2249 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2250 if (sym.kind >= AMBIGUOUS) {
2251 sym = super.access(env, pos, location, sym);
2252 } else if (allowMethodHandles) {
2253 MethodSymbol msym = (MethodSymbol)sym;
2254 if (msym.isSignaturePolymorphic(types)) {
2255 return findPolymorphicSignatureInstance(env, sym, argtypes);
2256 }
2257 }
2258 return sym;
2259 }
2260 });
2261 }
2262
2263 /** Find or create an implicit method of exactly the given type (after erasure).
2264 * Searches in a side table, not the main scope of the site.
2265 * This emulates the lookup process required by JSR 292 in JVM.
2266 * @param env Attribution environment
2267 * @param spMethod signature polymorphic method - i.e. MH.invokeExact
2268 * @param argtypes The required argument types
2269 */
2270 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env,
2271 final Symbol spMethod,
2272 List<Type> argtypes) {
2273 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
2274 (MethodSymbol)spMethod, currentResolutionContext, argtypes);
2275 for (Symbol sym : polymorphicSignatureScope.getElementsByName(spMethod.name)) {
2276 if (types.isSameType(mtype, sym.type)) {
2277 return sym;
2278 }
2279 }
2280
2281 // create the desired method
2282 long flags = ABSTRACT | HYPOTHETICAL | spMethod.flags() & Flags.AccessFlags;
2283 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) {
2284 @Override
2285 public Symbol baseSymbol() {
2286 return spMethod;
2287 }
2288 };
2289 polymorphicSignatureScope.enter(msym);
2290 return msym;
2291 }
2292
2293 /** Resolve a qualified method identifier, throw a fatal error if not
2294 * found.
2295 * @param pos The position to use for error reporting.
2296 * @param env The environment current at the method invocation.
2297 * @param site The type of the qualifying expression, in which
2298 * identifier is searched.
2299 * @param name The identifier's name.
2300 * @param argtypes The types of the invocation's value arguments.
2301 * @param typeargtypes The types of the invocation's type arguments.
2302 */
2303 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
2304 Type site, Name name,
2305 List<Type> argtypes,
2306 List<Type> typeargtypes) {
2307 MethodResolutionContext resolveContext = new MethodResolutionContext();
2308 resolveContext.internalResolution = true;
2309 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
2310 site, name, argtypes, typeargtypes);
2311 if (sym.kind == MTH) return (MethodSymbol)sym;
2312 else throw new FatalError(
2313 diags.fragment("fatal.err.cant.locate.meth",
2314 name));
2315 }
2316
2317 /** Resolve constructor.
2318 * @param pos The position to use for error reporting.
2319 * @param env The environment current at the constructor invocation.
2320 * @param site The type of class for which a constructor is searched.
2321 * @param argtypes The types of the constructor invocation's value
2322 * arguments.
2323 * @param typeargtypes The types of the constructor invocation's type
2324 * arguments.
2325 */
2326 Symbol resolveConstructor(DiagnosticPosition pos,
2327 Env<AttrContext> env,
2328 Type site,
2329 List<Type> argtypes,
2330 List<Type> typeargtypes) {
2331 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
2332 }
2333
2334 private Symbol resolveConstructor(MethodResolutionContext resolveContext,
2335 final DiagnosticPosition pos,
2336 Env<AttrContext> env,
2337 Type site,
2338 List<Type> argtypes,
2339 List<Type> typeargtypes) {
2340 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2341 @Override
2342 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2343 return findConstructor(pos, env, site, argtypes, typeargtypes,
2344 phase.isBoxingRequired(),
2345 phase.isVarargsRequired());
2346 }
2347 });
2348 }
2349
2350 /** Resolve a constructor, throw a fatal error if not found.
2351 * @param pos The position to use for error reporting.
2352 * @param env The environment current at the method invocation.
2353 * @param site The type to be constructed.
2354 * @param argtypes The types of the invocation's value arguments.
2355 * @param typeargtypes The types of the invocation's type arguments.
2356 */
2357 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2358 Type site,
2359 List<Type> argtypes,
2360 List<Type> typeargtypes) {
2361 MethodResolutionContext resolveContext = new MethodResolutionContext();
2362 resolveContext.internalResolution = true;
2363 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
2364 if (sym.kind == MTH) return (MethodSymbol)sym;
2365 else throw new FatalError(
2366 diags.fragment("fatal.err.cant.locate.ctor", site));
2367 }
2368
2369 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2370 Type site, List<Type> argtypes,
2371 List<Type> typeargtypes,
2372 boolean allowBoxing,
2373 boolean useVarargs) {
2374 Symbol sym = findMethod(env, site,
2375 names.init, argtypes,
2376 typeargtypes, allowBoxing,
2377 useVarargs, false);
2378 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2379 return sym;
2380 }
2381
2382 /** Resolve constructor using diamond inference.
2383 * @param pos The position to use for error reporting.
2384 * @param env The environment current at the constructor invocation.
2385 * @param site The type of class for which a constructor is searched.
2386 * The scope of this class has been touched in attribution.
2387 * @param argtypes The types of the constructor invocation's value
2388 * arguments.
2389 * @param typeargtypes The types of the constructor invocation's type
2390 * arguments.
2391 */
2392 Symbol resolveDiamond(DiagnosticPosition pos,
2393 Env<AttrContext> env,
2394 Type site,
2395 List<Type> argtypes,
2396 List<Type> typeargtypes) {
2397 return lookupMethod(env, pos, site.tsym, resolveMethodCheck,
2398 new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2399 @Override
2400 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2401 return findDiamond(env, site, argtypes, typeargtypes,
2402 phase.isBoxingRequired(),
2403 phase.isVarargsRequired());
2404 }
2405 @Override
2406 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2407 if (sym.kind >= AMBIGUOUS) {
2408 final JCDiagnostic details = sym.kind == WRONG_MTH ?
2409 ((InapplicableSymbolError)sym).errCandidate().details :
2410 null;
2411 sym = new InapplicableSymbolError(sym.kind, "diamondError", currentResolutionContext) {
2412 @Override
2413 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
2414 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
2415 String key = details == null ?
2416 "cant.apply.diamond" :
2417 "cant.apply.diamond.1";
2418 return diags.create(dkind, log.currentSource(), pos, key,
2419 diags.fragment("diamond", site.tsym), details);
2420 }
2421 };
2422 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes);
2423 env.info.pendingResolutionPhase = currentResolutionContext.step;
2424 }
2425 return sym;
2426 }});
2427 }
2428
2429 /** This method scans all the constructor symbol in a given class scope -
2430 * assuming that the original scope contains a constructor of the kind:
2431 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
2432 * a method check is executed against the modified constructor type:
2433 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond
2434 * inference. The inferred return type of the synthetic constructor IS
2435 * the inferred type for the diamond operator.
2436 */
2437 private Symbol findDiamond(Env<AttrContext> env,
2438 Type site,
2439 List<Type> argtypes,
2440 List<Type> typeargtypes,
2441 boolean allowBoxing,
2442 boolean useVarargs) {
2443 Symbol bestSoFar = methodNotFound;
2444 for (Scope.Entry e = site.tsym.members().lookup(names.init);
2445 e.scope != null;
2446 e = e.next()) {
2447 final Symbol sym = e.sym;
2448 //- System.out.println(" e " + e.sym);
2449 if (sym.kind == MTH &&
2450 (sym.flags_field & SYNTHETIC) == 0) {
2451 List<Type> oldParams = e.sym.type.hasTag(FORALL) ?
2452 ((ForAll)sym.type).tvars :
2453 List.<Type>nil();
2454 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
2455 types.createMethodTypeWithReturn(sym.type.asMethodType(), site));
2456 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) {
2457 @Override
2458 public Symbol baseSymbol() {
2459 return sym;
2460 }
2461 };
2462 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
2463 newConstr,
2464 bestSoFar,
2465 allowBoxing,
2466 useVarargs,
2467 false);
2468 }
2469 }
2470 return bestSoFar;
2471 }
2472
2473
2474
2475 /** Resolve operator.
2476 * @param pos The position to use for error reporting.
2477 * @param optag The tag of the operation tree.
2478 * @param env The environment current at the operation.
2479 * @param argtypes The types of the operands.
2480 */
2481 Symbol resolveOperator(DiagnosticPosition pos, JCTree.Tag optag,
2482 Env<AttrContext> env, List<Type> argtypes) {
2483 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2484 try {
2485 currentResolutionContext = new MethodResolutionContext();
2486 Name name = treeinfo.operatorName(optag);
2487 env.info.pendingResolutionPhase = currentResolutionContext.step = BASIC;
2488 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
2489 null, false, false, true);
2490 if (boxingEnabled && sym.kind >= WRONG_MTHS)
2491 env.info.pendingResolutionPhase = currentResolutionContext.step = BOX;
2492 sym = findMethod(env, syms.predefClass.type, name, argtypes,
2493 null, true, false, true);
2494 return accessMethod(sym, pos, env.enclClass.sym.type, name,
2495 false, argtypes, null);
2496 }
2497 finally {
2498 currentResolutionContext = prevResolutionContext;
2499 }
2500 }
2501
2502 /** Resolve operator.
2503 * @param pos The position to use for error reporting.
2504 * @param optag The tag of the operation tree.
2505 * @param env The environment current at the operation.
2506 * @param arg The type of the operand.
2507 */
2508 Symbol resolveUnaryOperator(DiagnosticPosition pos, JCTree.Tag optag, Env<AttrContext> env, Type arg) {
2509 return resolveOperator(pos, optag, env, List.of(arg));
2510 }
2511
2512 /** Resolve binary operator.
2513 * @param pos The position to use for error reporting.
2514 * @param optag The tag of the operation tree.
2515 * @param env The environment current at the operation.
2516 * @param left The types of the left operand.
2517 * @param right The types of the right operand.
2518 */
2519 Symbol resolveBinaryOperator(DiagnosticPosition pos,
2520 JCTree.Tag optag,
2521 Env<AttrContext> env,
2522 Type left,
2523 Type right) {
2524 return resolveOperator(pos, optag, env, List.of(left, right));
2525 }
2526
2527 /**
2528 * Resolution of member references is typically done as a single
2529 * overload resolution step, where the argument types A are inferred from
2530 * the target functional descriptor.
2531 *
2532 * If the member reference is a method reference with a type qualifier,
2533 * a two-step lookup process is performed. The first step uses the
2534 * expected argument list A, while the second step discards the first
2535 * type from A (which is treated as a receiver type).
2536 *
2537 * There are two cases in which inference is performed: (i) if the member
2538 * reference is a constructor reference and the qualifier type is raw - in
2539 * which case diamond inference is used to infer a parameterization for the
2540 * type qualifier; (ii) if the member reference is an unbound reference
2541 * where the type qualifier is raw - in that case, during the unbound lookup
2542 * the receiver argument type is used to infer an instantiation for the raw
2543 * qualifier type.
2544 *
2545 * When a multi-step resolution process is exploited, it is an error
2546 * if two candidates are found (ambiguity).
2547 *
2548 * This routine returns a pair (T,S), where S is the member reference symbol,
2549 * and T is the type of the class in which S is defined. This is necessary as
2550 * the type T might be dynamically inferred (i.e. if constructor reference
2551 * has a raw qualifier).
2552 */
2553 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(DiagnosticPosition pos,
2554 Env<AttrContext> env,
2555 JCMemberReference referenceTree,
2556 Type site,
2557 Name name, List<Type> argtypes,
2558 List<Type> typeargtypes,
2559 boolean boxingAllowed,
2560 MethodCheck methodCheck) {
2561 MethodResolutionPhase maxPhase = boxingAllowed ? VARARITY : BASIC;
2562
2563 ReferenceLookupHelper boundLookupHelper;
2564 if (!name.equals(names.init)) {
2565 //method reference
2566 boundLookupHelper =
2567 new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2568 } else if (site.hasTag(ARRAY)) {
2569 //array constructor reference
2570 boundLookupHelper =
2571 new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2572 } else {
2573 //class constructor reference
2574 boundLookupHelper =
2575 new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2576 }
2577
2578 //step 1 - bound lookup
2579 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup());
2580 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(), site.tsym, methodCheck, boundLookupHelper);
2581
2582 //step 2 - unbound lookup
2583 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup();
2584 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup());
2585 Symbol unboundSym = lookupMethod(unboundEnv, env.tree.pos(), site.tsym, methodCheck, unboundLookupHelper);
2586
2587 //merge results
2588 Pair<Symbol, ReferenceLookupHelper> res;
2589 if (!lookupSuccess(unboundSym)) {
2590 res = new Pair<Symbol, ReferenceLookupHelper>(boundSym, boundLookupHelper);
2591 env.info.pendingResolutionPhase = boundEnv.info.pendingResolutionPhase;
2592 } else if (lookupSuccess(boundSym)) {
2593 res = new Pair<Symbol, ReferenceLookupHelper>(ambiguityError(boundSym, unboundSym), boundLookupHelper);
2594 env.info.pendingResolutionPhase = boundEnv.info.pendingResolutionPhase;
2595 } else {
2596 res = new Pair<Symbol, ReferenceLookupHelper>(unboundSym, unboundLookupHelper);
2597 env.info.pendingResolutionPhase = unboundEnv.info.pendingResolutionPhase;
2598 }
2599
2600 return res;
2601 }
2602 //private
2603 boolean lookupSuccess(Symbol s) {
2604 return s.kind == MTH || s.kind == AMBIGUOUS;
2605 }
2606
2607 /**
2608 * Helper for defining custom method-like lookup logic; a lookup helper
2609 * provides hooks for (i) the actual lookup logic and (ii) accessing the
2610 * lookup result (this step might result in compiler diagnostics to be generated)
2611 */
2612 abstract class LookupHelper {
2613
2614 /** name of the symbol to lookup */
2615 Name name;
2616
2617 /** location in which the lookup takes place */
2618 Type site;
2619
2620 /** actual types used during the lookup */
2621 List<Type> argtypes;
2622
2623 /** type arguments used during the lookup */
2624 List<Type> typeargtypes;
2625
2626 /** Max overload resolution phase handled by this helper */
2627 MethodResolutionPhase maxPhase;
2628
2629 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2630 this.name = name;
2631 this.site = site;
2632 this.argtypes = argtypes;
2633 this.typeargtypes = typeargtypes;
2634 this.maxPhase = maxPhase;
2635 }
2636
2637 /**
2638 * Should lookup stop at given phase with given result
2639 */
2640 protected boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
2641 return phase.ordinal() > maxPhase.ordinal() ||
2642 sym.kind < ERRONEOUS || sym.kind == AMBIGUOUS;
2643 }
2644
2645 /**
2646 * Search for a symbol under a given overload resolution phase - this method
2647 * is usually called several times, once per each overload resolution phase
2648 */
2649 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase);
2650
2651 /**
2652 * Validate the result of the lookup
2653 */
2654 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym);
2655 }
2656
2657 abstract class BasicLookupHelper extends LookupHelper {
2658
2659 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) {
2660 super(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY);
2661 }
2662
2663 @Override
2664 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2665 if (sym.kind == AMBIGUOUS) {
2666 AmbiguityError a_err = (AmbiguityError)sym;
2667 sym = a_err.mergeAbstracts(site);
2668 }
2669 if (sym.kind >= AMBIGUOUS) {
2670 //if nothing is found return the 'first' error
2671 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes);
2672 }
2673 return sym;
2674 }
2675 }
2676
2677 /**
2678 * Helper class for member reference lookup. A reference lookup helper
2679 * defines the basic logic for member reference lookup; a method gives
2680 * access to an 'unbound' helper used to perform an unbound member
2681 * reference lookup.
2682 */
2683 abstract class ReferenceLookupHelper extends LookupHelper {
2684
2685 /** The member reference tree */
2686 JCMemberReference referenceTree;
2687
2688 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2689 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2690 super(name, site, argtypes, typeargtypes, maxPhase);
2691 this.referenceTree = referenceTree;
2692
2693 }
2694
2695 /**
2696 * Returns an unbound version of this lookup helper. By default, this
2697 * method returns an dummy lookup helper.
2698 */
2699 ReferenceLookupHelper unboundLookup() {
2700 //dummy loopkup helper that always return 'methodNotFound'
2701 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) {
2702 @Override
2703 ReferenceLookupHelper unboundLookup() {
2704 return this;
2705 }
2706 @Override
2707 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2708 return methodNotFound;
2709 }
2710 @Override
2711 ReferenceKind referenceKind(Symbol sym) {
2712 Assert.error();
2713 return null;
2714 }
2715 };
2716 }
2717
2718 /**
2719 * Get the kind of the member reference
2720 */
2721 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym);
2722
2723 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2724 if (sym.kind == AMBIGUOUS) {
2725 AmbiguityError a_err = (AmbiguityError)sym;
2726 sym = a_err.mergeAbstracts(site);
2727 }
2728 //skip error reporting
2729 return sym;
2730 }
2731 }
2732
2733 /**
2734 * Helper class for method reference lookup. The lookup logic is based
2735 * upon Resolve.findMethod; in certain cases, this helper class has a
2736 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper).
2737 * In such cases, non-static lookup results are thrown away.
2738 */
2739 class MethodReferenceLookupHelper extends ReferenceLookupHelper {
2740
2741 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2742 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2743 super(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2744 }
2745
2746 @Override
2747 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2748 return findMethod(env, site, name, argtypes, typeargtypes,
2749 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
2750 }
2751
2752 @Override
2753 ReferenceLookupHelper unboundLookup() {
2754 if (TreeInfo.isStaticSelector(referenceTree.expr, names) &&
2755 argtypes.nonEmpty() &&
2756 (argtypes.head.hasTag(NONE) || types.isSubtypeUnchecked(argtypes.head, site))) {
2757 return new UnboundMethodReferenceLookupHelper(referenceTree, name,
2758 site, argtypes, typeargtypes, maxPhase);
2759 } else {
2760 return super.unboundLookup();
2761 }
2762 }
2763
2764 @Override
2765 ReferenceKind referenceKind(Symbol sym) {
2766 if (sym.isStatic()) {
2767 return ReferenceKind.STATIC;
2768 } else {
2769 Name selName = TreeInfo.name(referenceTree.getQualifierExpression());
2770 return selName != null && selName == names._super ?
2771 ReferenceKind.SUPER :
2772 ReferenceKind.BOUND;
2773 }
2774 }
2775 }
2776
2777 /**
2778 * Helper class for unbound method reference lookup. Essentially the same
2779 * as the basic method reference lookup helper; main difference is that static
2780 * lookup results are thrown away. If qualifier type is raw, an attempt to
2781 * infer a parameterized type is made using the first actual argument (that
2782 * would otherwise be ignored during the lookup).
2783 */
2784 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper {
2785
2786 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2787 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2788 super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase);
2789 if (site.isRaw() && !argtypes.head.hasTag(NONE)) {
2790 Type asSuperSite = types.asSuper(argtypes.head, site.tsym);
2791 this.site = asSuperSite;
2792 }
2793 }
2794
2795 @Override
2796 ReferenceLookupHelper unboundLookup() {
2797 return this;
2798 }
2799
2800 @Override
2801 ReferenceKind referenceKind(Symbol sym) {
2802 return ReferenceKind.UNBOUND;
2803 }
2804 }
2805
2806 /**
2807 * Helper class for array constructor lookup; an array constructor lookup
2808 * is simulated by looking up a method that returns the array type specified
2809 * as qualifier, and that accepts a single int parameter (size of the array).
2810 */
2811 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper {
2812
2813 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
2814 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2815 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
2816 }
2817
2818 @Override
2819 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2820 Scope sc = new Scope(syms.arrayClass);
2821 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym);
2822 arrayConstr.type = new MethodType(List.of(syms.intType), site, List.<Type>nil(), syms.methodClass);
2823 sc.enter(arrayConstr);
2824 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false, false);
2825 }
2826
2827 @Override
2828 ReferenceKind referenceKind(Symbol sym) {
2829 return ReferenceKind.ARRAY_CTOR;
2830 }
2831 }
2832
2833 /**
2834 * Helper class for constructor reference lookup. The lookup logic is based
2835 * upon either Resolve.findMethod or Resolve.findDiamond - depending on
2836 * whether the constructor reference needs diamond inference (this is the case
2837 * if the qualifier type is raw). A special erroneous symbol is returned
2838 * if the lookup returns the constructor of an inner class and there's no
2839 * enclosing instance in scope.
2840 */
2841 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper {
2842
2843 boolean needsInference;
2844
2845 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
2846 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2847 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
2848 if (site.isRaw()) {
2849 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym);
2850 needsInference = true;
2851 }
2852 }
2853
2854 @Override
2855 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2856 Symbol sym = needsInference ?
2857 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) :
2858 findMethod(env, site, name, argtypes, typeargtypes,
2859 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
2860 return sym.kind != MTH ||
2861 site.getEnclosingType().hasTag(NONE) ||
2862 hasEnclosingInstance(env, site) ?
2863 sym : new InvalidSymbolError(Kinds.MISSING_ENCL, sym, null) {
2864 @Override
2865 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
2866 return diags.create(dkind, log.currentSource(), pos,
2867 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType());
2868 }
2869 };
2870 }
2871
2872 @Override
2873 ReferenceKind referenceKind(Symbol sym) {
2874 return site.getEnclosingType().hasTag(NONE) ?
2875 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER;
2876 }
2877 }
2878
2879 /**
2880 * Main overload resolution routine. On each overload resolution step, a
2881 * lookup helper class is used to perform the method/constructor lookup;
2882 * at the end of the lookup, the helper is used to validate the results
2883 * (this last step might trigger overload resolution diagnostics).
2884 */
2885 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, MethodCheck methodCheck, LookupHelper lookupHelper) {
2886 MethodResolutionContext resolveContext = new MethodResolutionContext();
2887 resolveContext.methodCheck = methodCheck;
2888 return lookupMethod(env, pos, location, resolveContext, lookupHelper);
2889 }
2890
2891 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location,
2892 MethodResolutionContext resolveContext, LookupHelper lookupHelper) {
2893 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2894 try {
2895 Symbol bestSoFar = methodNotFound;
2896 currentResolutionContext = resolveContext;
2897 for (MethodResolutionPhase phase : methodResolutionSteps) {
2898 if (!phase.isApplicable(boxingEnabled, varargsEnabled) ||
2899 lookupHelper.shouldStop(bestSoFar, phase)) break;
2900 MethodResolutionPhase prevPhase = currentResolutionContext.step;
2901 Symbol prevBest = bestSoFar;
2902 currentResolutionContext.step = phase;
2903 bestSoFar = phase.mergeResults(bestSoFar, lookupHelper.lookup(env, phase));
2904 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase;
2905 }
2906 return lookupHelper.access(env, pos, location, bestSoFar);
2907 } finally {
2908 currentResolutionContext = prevResolutionContext;
2909 }
2910 }
2911
2912 /**
2913 * Resolve `c.name' where name == this or name == super.
2914 * @param pos The position to use for error reporting.
2915 * @param env The environment current at the expression.
2916 * @param c The qualifier.
2917 * @param name The identifier's name.
2918 */
2919 Symbol resolveSelf(DiagnosticPosition pos,
2920 Env<AttrContext> env,
2921 TypeSymbol c,
2922 Name name) {
2923 Env<AttrContext> env1 = env;
2924 boolean staticOnly = false;
2925 while (env1.outer != null) {
2926 if (isStatic(env1)) staticOnly = true;
2927 if (env1.enclClass.sym == c) {
2928 Symbol sym = env1.info.scope.lookup(name).sym;
2929 if (sym != null) {
2930 if (staticOnly) sym = new StaticError(sym);
2931 return accessBase(sym, pos, env.enclClass.sym.type,
2932 name, true);
2933 }
2934 }
2935 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
2936 env1 = env1.outer;
2937 }
2938 if (allowDefaultMethods && c.isInterface() &&
2939 name == names._super && !isStatic(env) &&
2940 types.isDirectSuperInterface(c, env.enclClass.sym)) {
2941 //this might be a default super call if one of the superinterfaces is 'c'
2942 for (Type t : pruneInterfaces(env.enclClass.type)) {
2943 if (t.tsym == c) {
2944 env.info.defaultSuperCallSite = t;
2945 return new VarSymbol(0, names._super,
2946 types.asSuper(env.enclClass.type, c), env.enclClass.sym);
2947 }
2948 }
2949 //find a direct superinterface that is a subtype of 'c'
2950 for (Type i : types.interfaces(env.enclClass.type)) {
2951 if (i.tsym.isSubClass(c, types) && i.tsym != c) {
2952 log.error(pos, "illegal.default.super.call", c,
2953 diags.fragment("redundant.supertype", c, i));
2954 return syms.errSymbol;
2955 }
2956 }
2957 Assert.error();
2958 }
2959 log.error(pos, "not.encl.class", c);
2960 return syms.errSymbol;
2961 }
2962 //where
2963 private List<Type> pruneInterfaces(Type t) {
2964 ListBuffer<Type> result = ListBuffer.lb();
2965 for (Type t1 : types.interfaces(t)) {
2966 boolean shouldAdd = true;
2967 for (Type t2 : types.interfaces(t)) {
2968 if (t1 != t2 && types.isSubtypeNoCapture(t2, t1)) {
2969 shouldAdd = false;
2970 }
2971 }
2972 if (shouldAdd) {
2973 result.append(t1);
2974 }
2975 }
2976 return result.toList();
2977 }
2978
2979
2980 /**
2981 * Resolve `c.this' for an enclosing class c that contains the
2982 * named member.
2983 * @param pos The position to use for error reporting.
2984 * @param env The environment current at the expression.
2985 * @param member The member that must be contained in the result.
2986 */
2987 Symbol resolveSelfContaining(DiagnosticPosition pos,
2988 Env<AttrContext> env,
2989 Symbol member,
2990 boolean isSuperCall) {
2991 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall);
2992 if (sym == null) {
2993 log.error(pos, "encl.class.required", member);
2994 return syms.errSymbol;
2995 } else {
2996 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true);
2997 }
2998 }
2999
3000 boolean hasEnclosingInstance(Env<AttrContext> env, Type type) {
3001 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false);
3002 return encl != null && encl.kind < ERRONEOUS;
3003 }
3004
3005 private Symbol resolveSelfContainingInternal(Env<AttrContext> env,
3006 Symbol member,
3007 boolean isSuperCall) {
3008 Name name = names._this;
3009 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
3010 boolean staticOnly = false;
3011 if (env1 != null) {
3012 while (env1 != null && env1.outer != null) {
3013 if (isStatic(env1)) staticOnly = true;
3014 if (env1.enclClass.sym.isSubClass(member.owner, types)) {
3015 Symbol sym = env1.info.scope.lookup(name).sym;
3016 if (sym != null) {
3017 if (staticOnly) sym = new StaticError(sym);
3018 return sym;
3019 }
3020 }
3021 if ((env1.enclClass.sym.flags() & STATIC) != 0)
3022 staticOnly = true;
3023 env1 = env1.outer;
3024 }
3025 }
3026 return null;
3027 }
3028
3029 /**
3030 * Resolve an appropriate implicit this instance for t's container.
3031 * JLS 8.8.5.1 and 15.9.2
3032 */
3033 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
3034 return resolveImplicitThis(pos, env, t, false);
3035 }
3036
3037 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
3038 Type thisType = (((t.tsym.owner.kind & (MTH|VAR)) != 0)
3039 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
3040 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
3041 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym)
3042 log.error(pos, "cant.ref.before.ctor.called", "this");
3043 return thisType;
3044 }
3045
3046 /* ***************************************************************************
3047 * ResolveError classes, indicating error situations when accessing symbols
3048 ****************************************************************************/
3049
3050 //used by TransTypes when checking target type of synthetic cast
3051 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) {
3052 AccessError error = new AccessError(env, env.enclClass.type, type.tsym);
3053 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null);
3054 }
3055 //where
3056 private void logResolveError(ResolveError error,
3057 DiagnosticPosition pos,
3058 Symbol location,
3059 Type site,
3060 Name name,
3061 List<Type> argtypes,
3062 List<Type> typeargtypes) {
3063 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
3064 pos, location, site, name, argtypes, typeargtypes);
3065 if (d != null) {
3066 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
3067 log.report(d);
3068 }
3069 }
3070
3071 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
3072
3073 public Object methodArguments(List<Type> argtypes) {
3074 if (argtypes == null || argtypes.isEmpty()) {
3075 return noArgs;
3076 } else {
3077 ListBuffer<Object> diagArgs = ListBuffer.lb();
3078 for (Type t : argtypes) {
3079 if (t.hasTag(DEFERRED)) {
3080 diagArgs.append(((DeferredAttr.DeferredType)t).tree);
3081 } else {
3082 diagArgs.append(t);
3083 }
3084 }
3085 return diagArgs;
3086 }
3087 }
3088
3089 /**
3090 * Root class for resolution errors. Subclass of ResolveError
3091 * represent a different kinds of resolution error - as such they must
3092 * specify how they map into concrete compiler diagnostics.
3093 */
3094 abstract class ResolveError extends Symbol {
3095
3096 /** The name of the kind of error, for debugging only. */
3097 final String debugName;
3098
3099 ResolveError(int kind, String debugName) {
3100 super(kind, 0, null, null, null);
3101 this.debugName = debugName;
3102 }
3103
3104 @Override
3105 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
3106 throw new AssertionError();
3107 }
3108
3109 @Override
3110 public String toString() {
3111 return debugName;
3112 }
3113
3114 @Override
3115 public boolean exists() {
3116 return false;
3117 }
3118
3119 /**
3120 * Create an external representation for this erroneous symbol to be
3121 * used during attribution - by default this returns the symbol of a
3122 * brand new error type which stores the original type found
3123 * during resolution.
3124 *
3125 * @param name the name used during resolution
3126 * @param location the location from which the symbol is accessed
3127 */
3128 protected Symbol access(Name name, TypeSymbol location) {
3129 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3130 }
3131
3132 /**
3133 * Create a diagnostic representing this resolution error.
3134 *
3135 * @param dkind The kind of the diagnostic to be created (e.g error).
3136 * @param pos The position to be used for error reporting.
3137 * @param site The original type from where the selection took place.
3138 * @param name The name of the symbol to be resolved.
3139 * @param argtypes The invocation's value arguments,
3140 * if we looked for a method.
3141 * @param typeargtypes The invocation's type arguments,
3142 * if we looked for a method.
3143 */
3144 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3145 DiagnosticPosition pos,
3146 Symbol location,
3147 Type site,
3148 Name name,
3149 List<Type> argtypes,
3150 List<Type> typeargtypes);
3151 }
3152
3153 /**
3154 * This class is the root class of all resolution errors caused by
3155 * an invalid symbol being found during resolution.
3156 */
3157 abstract class InvalidSymbolError extends ResolveError {
3158
3159 /** The invalid symbol found during resolution */
3160 Symbol sym;
3161
3162 InvalidSymbolError(int kind, Symbol sym, String debugName) {
3163 super(kind, debugName);
3164 this.sym = sym;
3165 }
3166
3167 @Override
3168 public boolean exists() {
3169 return true;
3170 }
3171
3172 @Override
3173 public String toString() {
3174 return super.toString() + " wrongSym=" + sym;
3175 }
3176
3177 @Override
3178 public Symbol access(Name name, TypeSymbol location) {
3179 if ((sym.kind & ERRONEOUS) == 0 && (sym.kind & TYP) != 0)
3180 return types.createErrorType(name, location, sym.type).tsym;
3181 else
3182 return sym;
3183 }
3184 }
3185
3186 /**
3187 * InvalidSymbolError error class indicating that a symbol matching a
3188 * given name does not exists in a given site.
3189 */
3190 class SymbolNotFoundError extends ResolveError {
3191
3192 SymbolNotFoundError(int kind) {
3193 super(kind, "symbol not found error");
3194 }
3195
3196 @Override
3197 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3198 DiagnosticPosition pos,
3199 Symbol location,
3200 Type site,
3201 Name name,
3202 List<Type> argtypes,
3203 List<Type> typeargtypes) {
3204 argtypes = argtypes == null ? List.<Type>nil() : argtypes;
3205 typeargtypes = typeargtypes == null ? List.<Type>nil() : typeargtypes;
3206 if (name == names.error)
3207 return null;
3208
3209 if (syms.operatorNames.contains(name)) {
3210 boolean isUnaryOp = argtypes.size() == 1;
3211 String key = argtypes.size() == 1 ?
3212 "operator.cant.be.applied" :
3213 "operator.cant.be.applied.1";
3214 Type first = argtypes.head;
3215 Type second = !isUnaryOp ? argtypes.tail.head : null;
3216 return diags.create(dkind, log.currentSource(), pos,
3217 key, name, first, second);
3218 }
3219 boolean hasLocation = false;
3220 if (location == null) {
3221 location = site.tsym;
3222 }
3223 if (!location.name.isEmpty()) {
3224 if (location.kind == PCK && !site.tsym.exists()) {
3225 return diags.create(dkind, log.currentSource(), pos,
3226 "doesnt.exist", location);
3227 }
3228 hasLocation = !location.name.equals(names._this) &&
3229 !location.name.equals(names._super);
3230 }
3231 boolean isConstructor = kind == ABSENT_MTH && name == names.init;
3232 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : absentKind(kind);
3233 Name idname = isConstructor ? site.tsym.name : name;
3234 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
3235 if (hasLocation) {
3236 return diags.create(dkind, log.currentSource(), pos,
3237 errKey, kindname, idname, //symbol kindname, name
3238 typeargtypes, args(argtypes), //type parameters and arguments (if any)
3239 getLocationDiag(location, site)); //location kindname, type
3240 }
3241 else {
3242 return diags.create(dkind, log.currentSource(), pos,
3243 errKey, kindname, idname, //symbol kindname, name
3244 typeargtypes, args(argtypes)); //type parameters and arguments (if any)
3245 }
3246 }
3247 //where
3248 private Object args(List<Type> args) {
3249 return args.isEmpty() ? args : methodArguments(args);
3250 }
3251
3252 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
3253 String key = "cant.resolve";
3254 String suffix = hasLocation ? ".location" : "";
3255 switch (kindname) {
3256 case METHOD:
3257 case CONSTRUCTOR: {
3258 suffix += ".args";
3259 suffix += hasTypeArgs ? ".params" : "";
3260 }
3261 }
3262 return key + suffix;
3263 }
3264 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
3265 if (location.kind == VAR) {
3266 return diags.fragment("location.1",
3267 kindName(location),
3268 location,
3269 location.type);
3270 } else {
3271 return diags.fragment("location",
3272 typeKindName(site),
3273 site,
3274 null);
3275 }
3276 }
3277 }
3278
3279 /**
3280 * InvalidSymbolError error class indicating that a given symbol
3281 * (either a method, a constructor or an operand) is not applicable
3282 * given an actual arguments/type argument list.
3283 */
3284 class InapplicableSymbolError extends ResolveError {
3285
3286 protected MethodResolutionContext resolveContext;
3287
3288 InapplicableSymbolError(MethodResolutionContext context) {
3289 this(WRONG_MTH, "inapplicable symbol error", context);
3290 }
3291
3292 protected InapplicableSymbolError(int kind, String debugName, MethodResolutionContext context) {
3293 super(kind, debugName);
3294 this.resolveContext = context;
3295 }
3296
3297 @Override
3298 public String toString() {
3299 return super.toString();
3300 }
3301
3302 @Override
3303 public boolean exists() {
3304 return true;
3305 }
3306
3307 @Override
3308 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3309 DiagnosticPosition pos,
3310 Symbol location,
3311 Type site,
3312 Name name,
3313 List<Type> argtypes,
3314 List<Type> typeargtypes) {
3315 if (name == names.error)
3316 return null;
3317
3318 if (syms.operatorNames.contains(name)) {
3319 boolean isUnaryOp = argtypes.size() == 1;
3320 String key = argtypes.size() == 1 ?
3321 "operator.cant.be.applied" :
3322 "operator.cant.be.applied.1";
3323 Type first = argtypes.head;
3324 Type second = !isUnaryOp ? argtypes.tail.head : null;
3325 return diags.create(dkind, log.currentSource(), pos,
3326 key, name, first, second);
3327 }
3328 else {
3329 Candidate c = errCandidate();
3330 Symbol ws = c.sym.asMemberOf(site, types);
3331 return diags.create(dkind, log.currentSource(), pos,
3332 "cant.apply.symbol",
3333 kindName(ws),
3334 ws.name == names.init ? ws.owner.name : ws.name,
3335 methodArguments(ws.type.getParameterTypes()),
3336 methodArguments(argtypes),
3337 kindName(ws.owner),
3338 ws.owner.type,
3339 c.details);
3340 }
3341 }
3342
3343 @Override
3344 public Symbol access(Name name, TypeSymbol location) {
3345 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3346 }
3347
3348 private Candidate errCandidate() {
3349 Candidate bestSoFar = null;
3350 for (Candidate c : resolveContext.candidates) {
3351 if (c.isApplicable()) continue;
3352 bestSoFar = c;
3353 }
3354 Assert.checkNonNull(bestSoFar);
3355 return bestSoFar;
3356 }
3357 }
3358
3359 /**
3360 * ResolveError error class indicating that a set of symbols
3361 * (either methods, constructors or operands) is not applicable
3362 * given an actual arguments/type argument list.
3363 */
3364 class InapplicableSymbolsError extends InapplicableSymbolError {
3365
3366 InapplicableSymbolsError(MethodResolutionContext context) {
3367 super(WRONG_MTHS, "inapplicable symbols", context);
3368 }
3369
3370 @Override
3371 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3372 DiagnosticPosition pos,
3373 Symbol location,
3374 Type site,
3375 Name name,
3376 List<Type> argtypes,
3377 List<Type> typeargtypes) {
3378 if (!resolveContext.candidates.isEmpty()) {
3379 JCDiagnostic err = diags.create(dkind,
3380 log.currentSource(),
3381 pos,
3382 "cant.apply.symbols",
3383 name == names.init ? KindName.CONSTRUCTOR : absentKind(kind),
3384 name == names.init ? site.tsym.name : name,
3385 methodArguments(argtypes));
3386 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(site));
3387 } else {
3388 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
3389 location, site, name, argtypes, typeargtypes);
3390 }
3391 }
3392
3393 //where
3394 List<JCDiagnostic> candidateDetails(Type site) {
3395 Map<Symbol, JCDiagnostic> details = new LinkedHashMap<Symbol, JCDiagnostic>();
3396 for (Candidate c : resolveContext.candidates) {
3397 if (c.isApplicable()) continue;
3398 JCDiagnostic detailDiag = diags.fragment("inapplicable.method",
3399 Kinds.kindName(c.sym),
3400 c.sym.location(site, types),
3401 c.sym.asMemberOf(site, types),
3402 c.details);
3403 details.put(c.sym, detailDiag);
3404 }
3405 return List.from(details.values());
3406 }
3407 }
3408
3409 /**
3410 * An InvalidSymbolError error class indicating that a symbol is not
3411 * accessible from a given site
3412 */
3413 class AccessError extends InvalidSymbolError {
3414
3415 private Env<AttrContext> env;
3416 private Type site;
3417
3418 AccessError(Symbol sym) {
3419 this(null, null, sym);
3420 }
3421
3422 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
3423 super(HIDDEN, sym, "access error");
3424 this.env = env;
3425 this.site = site;
3426 if (debugResolve)
3427 log.error("proc.messager", sym + " @ " + site + " is inaccessible.");
3428 }
3429
3430 @Override
3431 public boolean exists() {
3432 return false;
3433 }
3434
3435 @Override
3436 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3437 DiagnosticPosition pos,
3438 Symbol location,
3439 Type site,
3440 Name name,
3441 List<Type> argtypes,
3442 List<Type> typeargtypes) {
3443 if (sym.owner.type.hasTag(ERROR))
3444 return null;
3445
3446 if (sym.name == names.init && sym.owner != site.tsym) {
3447 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
3448 pos, location, site, name, argtypes, typeargtypes);
3449 }
3450 else if ((sym.flags() & PUBLIC) != 0
3451 || (env != null && this.site != null
3452 && !isAccessible(env, this.site))) {
3453 return diags.create(dkind, log.currentSource(),
3454 pos, "not.def.access.class.intf.cant.access",
3455 sym, sym.location());
3456 }
3457 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
3458 return diags.create(dkind, log.currentSource(),
3459 pos, "report.access", sym,
3460 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
3461 sym.location());
3462 }
3463 else {
3464 return diags.create(dkind, log.currentSource(),
3465 pos, "not.def.public.cant.access", sym, sym.location());
3466 }
3467 }
3468 }
3469
3470 /**
3471 * InvalidSymbolError error class indicating that an instance member
3472 * has erroneously been accessed from a static context.
3473 */
3474 class StaticError extends InvalidSymbolError {
3475
3476 StaticError(Symbol sym) {
3477 super(STATICERR, sym, "static error");
3478 }
3479
3480 @Override
3481 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3482 DiagnosticPosition pos,
3483 Symbol location,
3484 Type site,
3485 Name name,
3486 List<Type> argtypes,
3487 List<Type> typeargtypes) {
3488 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS))
3489 ? types.erasure(sym.type).tsym
3490 : sym);
3491 return diags.create(dkind, log.currentSource(), pos,
3492 "non-static.cant.be.ref", kindName(sym), errSym);
3493 }
3494 }
3495
3496 /**
3497 * InvalidSymbolError error class indicating that a pair of symbols
3498 * (either methods, constructors or operands) are ambiguous
3499 * given an actual arguments/type argument list.
3500 */
3501 class AmbiguityError extends ResolveError {
3502
3503 /** The other maximally specific symbol */
3504 List<Symbol> ambiguousSyms = List.nil();
3505
3506 @Override
3507 public boolean exists() {
3508 return true;
3509 }
3510
3511 AmbiguityError(Symbol sym1, Symbol sym2) {
3512 super(AMBIGUOUS, "ambiguity error");
3513 ambiguousSyms = flatten(sym2).appendList(flatten(sym1));
3514 }
3515
3516 private List<Symbol> flatten(Symbol sym) {
3517 if (sym.kind == AMBIGUOUS) {
3518 return ((AmbiguityError)sym).ambiguousSyms;
3519 } else {
3520 return List.of(sym);
3521 }
3522 }
3523
3524 AmbiguityError addAmbiguousSymbol(Symbol s) {
3525 ambiguousSyms = ambiguousSyms.prepend(s);
3526 return this;
3527 }
3528
3529 @Override
3530 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3531 DiagnosticPosition pos,
3532 Symbol location,
3533 Type site,
3534 Name name,
3535 List<Type> argtypes,
3536 List<Type> typeargtypes) {
3537 List<Symbol> diagSyms = ambiguousSyms.reverse();
3538 Symbol s1 = diagSyms.head;
3539 Symbol s2 = diagSyms.tail.head;
3540 Name sname = s1.name;
3541 if (sname == names.init) sname = s1.owner.name;
3542 return diags.create(dkind, log.currentSource(),
3543 pos, "ref.ambiguous", sname,
3544 kindName(s1),
3545 s1,
3546 s1.location(site, types),
3547 kindName(s2),
3548 s2,
3549 s2.location(site, types));
3550 }
3551
3552 /**
3553 * If multiple applicable methods are found during overload and none of them
3554 * is more specific than the others, attempt to merge their signatures.
3555 */
3556 Symbol mergeAbstracts(Type site) {
3557 Symbol fst = ambiguousSyms.last();
3558 Symbol res = fst;
3559 for (Symbol s : ambiguousSyms.reverse()) {
3560 Type mt1 = types.memberType(site, res);
3561 Type mt2 = types.memberType(site, s);
3562 if ((s.flags() & ABSTRACT) == 0 ||
3563 !types.overrideEquivalent(mt1, mt2) ||
3564 !types.isSameTypes(fst.erasure(types).getParameterTypes(),
3565 s.erasure(types).getParameterTypes())) {
3566 //ambiguity cannot be resolved
3567 return this;
3568 } else {
3569 Type mst = mostSpecificReturnType(mt1, mt2);
3570 if (mst == null) {
3571 // Theoretically, this can't happen, but it is possible
3572 // due to error recovery or mixing incompatible class files
3573 return this;
3574 }
3575 Symbol mostSpecific = mst == mt1 ? res : s;
3576 List<Type> allThrown = chk.intersect(mt1.getThrownTypes(), mt2.getThrownTypes());
3577 Type newSig = types.createMethodTypeWithThrown(mostSpecific.type, allThrown);
3578 res = new MethodSymbol(
3579 mostSpecific.flags(),
3580 mostSpecific.name,
3581 newSig,
3582 mostSpecific.owner);
3583 }
3584 }
3585 return res;
3586 }
3587
3588 @Override
3589 protected Symbol access(Name name, TypeSymbol location) {
3590 Symbol firstAmbiguity = ambiguousSyms.last();
3591 return firstAmbiguity.kind == TYP ?
3592 types.createErrorType(name, location, firstAmbiguity.type).tsym :
3593 firstAmbiguity;
3594 }
3595 }
3596
3597 class BadVarargsMethod extends ResolveError {
3598
3599 ResolveError delegatedError;
3600
3601 BadVarargsMethod(ResolveError delegatedError) {
3602 super(delegatedError.kind, "badVarargs");
3603 this.delegatedError = delegatedError;
3604 }
3605
3606 @Override
3607 public Symbol baseSymbol() {
3608 return delegatedError.baseSymbol();
3609 }
3610
3611 @Override
3612 protected Symbol access(Name name, TypeSymbol location) {
3613 return delegatedError.access(name, location);
3614 }
3615
3616 @Override
3617 public boolean exists() {
3618 return true;
3619 }
3620
3621 @Override
3622 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
3623 return delegatedError.getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes);
3624 }
3625 }
3626
3627 enum MethodResolutionPhase {
3628 BASIC(false, false),
3629 BOX(true, false),
3630 VARARITY(true, true) {
3631 @Override
3632 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) {
3633 switch (sym.kind) {
3634 case WRONG_MTH:
3635 return (bestSoFar.kind == WRONG_MTH || bestSoFar.kind == WRONG_MTHS) ?
3636 bestSoFar :
3637 sym;
3638 case ABSENT_MTH:
3639 return bestSoFar;
3640 default:
3641 return sym;
3642 }
3643 }
3644 };
3645
3646 final boolean isBoxingRequired;
3647 final boolean isVarargsRequired;
3648
3649 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
3650 this.isBoxingRequired = isBoxingRequired;
3651 this.isVarargsRequired = isVarargsRequired;
3652 }
3653
3654 public boolean isBoxingRequired() {
3655 return isBoxingRequired;
3656 }
3657
3658 public boolean isVarargsRequired() {
3659 return isVarargsRequired;
3660 }
3661
3662 public boolean isApplicable(boolean boxingEnabled, boolean varargsEnabled) {
3663 return (varargsEnabled || !isVarargsRequired) &&
3664 (boxingEnabled || !isBoxingRequired);
3665 }
3666
3667 public Symbol mergeResults(Symbol prev, Symbol sym) {
3668 return sym;
3669 }
3670 }
3671
3672 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
3673
3674 /**
3675 * A resolution context is used to keep track of intermediate results of
3676 * overload resolution, such as list of method that are not applicable
3677 * (used to generate more precise diagnostics) and so on. Resolution contexts
3678 * can be nested - this means that when each overload resolution routine should
3679 * work within the resolution context it created.
3680 */
3681 class MethodResolutionContext {
3682
3683 private List<Candidate> candidates = List.nil();
3684
3685 MethodResolutionPhase step = null;
3686
3687 MethodCheck methodCheck = resolveMethodCheck;
3688
3689 private boolean internalResolution = false;
3690 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE;
3691
3692 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) {
3693 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null);
3694 candidates = candidates.append(c);
3695 }
3696
3697 void addApplicableCandidate(Symbol sym, Type mtype) {
3698 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype);
3699 candidates = candidates.append(c);
3700 }
3701
3702 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext, ResultInfo pendingResult, Warner warn) {
3703 return deferredAttr.new DeferredAttrContext(attrMode, sym, step, inferenceContext, pendingResult != null ? pendingResult.checkContext.deferredAttrContext() : deferredAttr.emptyDeferredAttrContext, warn);
3704 }
3705
3706 /**
3707 * This class represents an overload resolution candidate. There are two
3708 * kinds of candidates: applicable methods and inapplicable methods;
3709 * applicable methods have a pointer to the instantiated method type,
3710 * while inapplicable candidates contain further details about the
3711 * reason why the method has been considered inapplicable.
3712 */
3713 @SuppressWarnings("overrides")
3714 class Candidate {
3715
3716 final MethodResolutionPhase step;
3717 final Symbol sym;
3718 final JCDiagnostic details;
3719 final Type mtype;
3720
3721 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) {
3722 this.step = step;
3723 this.sym = sym;
3724 this.details = details;
3725 this.mtype = mtype;
3726 }
3727
3728 @Override
3729 public boolean equals(Object o) {
3730 if (o instanceof Candidate) {
3731 Symbol s1 = this.sym;
3732 Symbol s2 = ((Candidate)o).sym;
3733 if ((s1 != s2 &&
3734 (s1.overrides(s2, s1.owner.type.tsym, types, false) ||
3735 (s2.overrides(s1, s2.owner.type.tsym, types, false)))) ||
3736 ((s1.isConstructor() || s2.isConstructor()) && s1.owner != s2.owner))
3737 return true;
3738 }
3739 return false;
3740 }
3741
3742 boolean isApplicable() {
3743 return mtype != null;
3744 }
3745 }
3746
3747 DeferredAttr.AttrMode attrMode() {
3748 return attrMode;
3749 }
3750
3751 boolean internal() {
3752 return internalResolution;
3753 }
3754 }
3755
3756 MethodResolutionContext currentResolutionContext = null;
3757 }