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
1788 /**
1789 * Find a type declared in a scope (not inherited). Return null
1790 * if none is found.
1791 * @param env The current environment.
1792 * @param site The original type from where the selection takes
1793 * place.
1794 * @param name The type's name.
1795 * @param c The class to search for the member type. This is
1796 * always a superclass or implemented interface of
1797 * site's class.
1798 */
1799 Symbol findImmediateMemberType(Env<AttrContext> env,
1800 Type site,
1801 Name name,
1802 TypeSymbol c) {
1803 Scope.Entry e = c.members().lookup(name);
1804 while (e.scope != null) {
1805 if (e.sym.kind == TYP) {
1806 return isAccessible(env, site, e.sym)
1807 ? e.sym
1808 : new AccessError(env, site, e.sym);
1809 }
1810 e = e.next();
1811 }
1812 return null;
1813 }
1814
1815 /** Find a member type inherited from a superclass or interface.
1816 * @param env The current environment.
1817 * @param site The original type from where the selection takes
1818 * place.
1819 * @param name The type's name.
1820 * @param c The class to search for the member type. This is
1821 * always a superclass or implemented interface of
1822 * site's class.
1823 */
1824 Symbol findInheritedMemberType(Env<AttrContext> env,
1825 Type site,
1826 Name name,
1827 TypeSymbol c) {
1828 Symbol bestSoFar = typeNotFound;
1829 Symbol sym;
1830 Type st = types.supertype(c.type);
1831 if (st != null && st.hasTag(CLASS)) {
1832 sym = findMemberType(env, site, name, st.tsym);
1833 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1834 }
1835 for (List<Type> l = types.interfaces(c.type);
1836 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1837 l = l.tail) {
1838 sym = findMemberType(env, site, name, l.head.tsym);
1839 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1840 sym.owner != bestSoFar.owner)
1841 bestSoFar = new AmbiguityError(bestSoFar, sym);
1842 else if (sym.kind < bestSoFar.kind)
1843 bestSoFar = sym;
1844 }
1845 return bestSoFar;
1846 }
1847
1848 /** Find qualified member type.
1849 * @param env The current environment.
1850 * @param site The original type from where the selection takes
1851 * place.
1852 * @param name The type's name.
1853 * @param c The class to search for the member type. This is
1854 * always a superclass or implemented interface of
1855 * site's class.
1856 */
1857 Symbol findMemberType(Env<AttrContext> env,
1858 Type site,
1859 Name name,
1860 TypeSymbol c) {
1861 Symbol sym = findImmediateMemberType(env, site, name, c);
1862
1863 if (sym != null)
1864 return sym;
1865
1866 return findInheritedMemberType(env, site, name, c);
1867
1868 }
1869
1870 /** Find a global type in given scope and load corresponding class.
1871 * @param env The current environment.
1872 * @param scope The scope in which to look for the type.
1873 * @param name The type's name.
1874 */
1875 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) {
1876 Symbol bestSoFar = typeNotFound;
1877 for (Scope.Entry e = scope.lookup(name); e.scope != null; e = e.next()) {
1878 Symbol sym = loadClass(env, e.sym.flatName());
1879 if (bestSoFar.kind == TYP && sym.kind == TYP &&
1880 bestSoFar != sym)
1881 return new AmbiguityError(bestSoFar, sym);
1882 else if (sym.kind < bestSoFar.kind)
1883 bestSoFar = sym;
1884 }
1885 return bestSoFar;
1886 }
1887
1888 /** Find an unqualified type symbol.
1889 * @param env The current environment.
1890 * @param name The type's name.
1891 */
1892 Symbol findType(Env<AttrContext> env, Name name) {
1893 Symbol bestSoFar = typeNotFound;
1894 Symbol sym;
1895 boolean staticOnly = false;
1896 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
1897 // First, try the members declared in the class
1898 sym = findImmediateMemberType(env1, env1.enclClass.sym.type,
1899 name, env1.enclClass.sym);
1900 // Then try the type parameters
1901 if (sym == null) {
1902 if (isStatic(env1)) staticOnly = true;
1903 for (Scope.Entry e = env1.info.scope.lookup(name);
1904 e.scope != null;
1905 e = e.next()) {
1906 if (e.sym.kind == TYP) {
1907 if (staticOnly &&
1908 e.sym.type.hasTag(TYPEVAR) &&
1909 e.sym.owner.kind == TYP)
1910 return new StaticError(e.sym);
1911 return e.sym;
1912 }
1913 }
1914 sym = findInheritedMemberType(env1, env1.enclClass.sym.type,
1915 name, env1.enclClass.sym);
1916 }
1917
1918 if (staticOnly && sym.kind == TYP &&
1919 sym.type.hasTag(CLASS) &&
1920 sym.type.getEnclosingType().hasTag(CLASS) &&
1921 env1.enclClass.sym.type.isParameterized() &&
1922 sym.type.getEnclosingType().isParameterized())
1923 return new StaticError(sym);
1924 else if (sym.exists()) return sym;
1925 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1926
1927 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
1928 if ((encl.sym.flags() & STATIC) != 0)
1929 staticOnly = true;
1930 }
1931
1932 if (!env.tree.hasTag(IMPORT)) {
1933 sym = findGlobalType(env, env.toplevel.namedImportScope, name);
1934 if (sym.exists()) return sym;
1935 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1936
1937 sym = findGlobalType(env, env.toplevel.packge.members(), name);
1938 if (sym.exists()) return sym;
1939 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1940
1941 sym = findGlobalType(env, env.toplevel.starImportScope, name);
1942 if (sym.exists()) return sym;
1943 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1944 }
1945
1946 return bestSoFar;
1947 }
1948
1949 /** Find an unqualified identifier which matches a specified kind set.
1950 * @param env The current environment.
1951 * @param name The identifier's name.
1952 * @param kind Indicates the possible symbol kinds
1953 * (a subset of VAL, TYP, PCK).
1954 */
1955 Symbol findIdent(Env<AttrContext> env, Name name, int kind) {
1956 Symbol bestSoFar = typeNotFound;
1957 Symbol sym;
1958
1959 if ((kind & VAR) != 0) {
1960 sym = findVar(env, name);
1961 if (sym.exists()) return sym;
1962 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1963 }
1964
1965 if ((kind & TYP) != 0) {
1966 sym = findType(env, name);
1967 if (sym.kind==TYP) {
1968 reportDependence(env.enclClass.sym, sym);
1969 }
1970 if (sym.exists()) return sym;
1971 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1972 }
1973
1974 if ((kind & PCK) != 0) return reader.enterPackage(name);
1975 else return bestSoFar;
1976 }
1977
1978 /** Report dependencies.
1979 * @param from The enclosing class sym
1980 * @param to The found identifier that the class depends on.
1981 */
1982 public void reportDependence(Symbol from, Symbol to) {
1983 // Override if you want to collect the reported dependencies.
1984 }
1985
1986 /** Find an identifier in a package which matches a specified kind set.
1987 * @param env The current environment.
1988 * @param name The identifier's name.
1989 * @param kind Indicates the possible symbol kinds
1990 * (a nonempty subset of TYP, PCK).
1991 */
1992 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
1993 Name name, int kind) {
1994 Name fullname = TypeSymbol.formFullName(name, pck);
1995 Symbol bestSoFar = typeNotFound;
1996 PackageSymbol pack = null;
1997 if ((kind & PCK) != 0) {
1998 pack = reader.enterPackage(fullname);
1999 if (pack.exists()) return pack;
2000 }
2001 if ((kind & TYP) != 0) {
2002 Symbol sym = loadClass(env, fullname);
2003 if (sym.exists()) {
2004 // don't allow programs to use flatnames
2005 if (name == sym.name) return sym;
2006 }
2007 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2008 }
2009 return (pack != null) ? pack : bestSoFar;
2010 }
2011
2012 /** Find an identifier among the members of a given type `site'.
2013 * @param env The current environment.
2014 * @param site The type containing the symbol to be found.
2015 * @param name The identifier's name.
2016 * @param kind Indicates the possible symbol kinds
2017 * (a subset of VAL, TYP).
2018 */
2019 Symbol findIdentInType(Env<AttrContext> env, Type site,
2020 Name name, int kind) {
2021 Symbol bestSoFar = typeNotFound;
2022 Symbol sym;
2023 if ((kind & VAR) != 0) {
2024 sym = findField(env, site, name, site.tsym);
2025 if (sym.exists()) return sym;
2026 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2027 }
2028
2029 if ((kind & TYP) != 0) {
2030 sym = findMemberType(env, site, name, site.tsym);
2031 if (sym.exists()) return sym;
2032 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2033 }
2034 return bestSoFar;
2035 }
2036
2037 /* ***************************************************************************
2038 * Access checking
2039 * The following methods convert ResolveErrors to ErrorSymbols, issuing
2040 * an error message in the process
2041 ****************************************************************************/
2042
2043 /** If `sym' is a bad symbol: report error and return errSymbol
2044 * else pass through unchanged,
2045 * additional arguments duplicate what has been used in trying to find the
2046 * symbol {@literal (--> flyweight pattern)}. This improves performance since we
2047 * expect misses to happen frequently.
2048 *
2049 * @param sym The symbol that was found, or a ResolveError.
2050 * @param pos The position to use for error reporting.
2051 * @param location The symbol the served as a context for this lookup
2052 * @param site The original type from where the selection took place.
2053 * @param name The symbol's name.
2054 * @param qualified Did we get here through a qualified expression resolution?
2055 * @param argtypes The invocation's value arguments,
2056 * if we looked for a method.
2057 * @param typeargtypes The invocation's type arguments,
2058 * if we looked for a method.
2059 * @param logResolveHelper helper class used to log resolve errors
2060 */
2061 Symbol accessInternal(Symbol sym,
2062 DiagnosticPosition pos,
2063 Symbol location,
2064 Type site,
2065 Name name,
2066 boolean qualified,
2067 List<Type> argtypes,
2068 List<Type> typeargtypes,
2069 LogResolveHelper logResolveHelper) {
2070 if (sym.kind >= AMBIGUOUS) {
2071 ResolveError errSym = (ResolveError)sym;
2072 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
2073 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes);
2074 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) {
2075 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
2076 }
2077 }
2078 return sym;
2079 }
2080
2081 /**
2082 * Variant of the generalized access routine, to be used for generating method
2083 * resolution diagnostics
2084 */
2085 Symbol accessMethod(Symbol sym,
2086 DiagnosticPosition pos,
2087 Symbol location,
2088 Type site,
2089 Name name,
2090 boolean qualified,
2091 List<Type> argtypes,
2092 List<Type> typeargtypes) {
2093 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper);
2094 }
2095
2096 /** Same as original accessMethod(), but without location.
2097 */
2098 Symbol accessMethod(Symbol sym,
2099 DiagnosticPosition pos,
2100 Type site,
2101 Name name,
2102 boolean qualified,
2103 List<Type> argtypes,
2104 List<Type> typeargtypes) {
2105 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
2106 }
2107
2108 /**
2109 * Variant of the generalized access routine, to be used for generating variable,
2110 * type resolution diagnostics
2111 */
2112 Symbol accessBase(Symbol sym,
2113 DiagnosticPosition pos,
2114 Symbol location,
2115 Type site,
2116 Name name,
2117 boolean qualified) {
2118 return accessInternal(sym, pos, location, site, name, qualified, List.<Type>nil(), null, basicLogResolveHelper);
2119 }
2120
2121 /** Same as original accessBase(), but without location.
2122 */
2123 Symbol accessBase(Symbol sym,
2124 DiagnosticPosition pos,
2125 Type site,
2126 Name name,
2127 boolean qualified) {
2128 return accessBase(sym, pos, site.tsym, site, name, qualified);
2129 }
2130
2131 interface LogResolveHelper {
2132 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes);
2133 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes);
2134 }
2135
2136 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() {
2137 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2138 return !site.isErroneous();
2139 }
2140 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2141 return argtypes;
2142 }
2143 };
2144
2145 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() {
2146 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2147 return !site.isErroneous() &&
2148 !Type.isErroneous(argtypes) &&
2149 (typeargtypes == null || !Type.isErroneous(typeargtypes));
2150 }
2151 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2152 return (syms.operatorNames.contains(name)) ?
2153 argtypes :
2154 Type.map(argtypes, new ResolveDeferredRecoveryMap(accessedSym));
2155 }
2156
2157 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap {
2158
2159 public ResolveDeferredRecoveryMap(Symbol msym) {
2160 deferredAttr.super(AttrMode.SPECULATIVE, msym, currentResolutionContext.step);
2161 }
2162
2163 @Override
2164 protected Type typeOf(DeferredType dt) {
2165 Type res = super.typeOf(dt);
2166 if (!res.isErroneous()) {
2167 switch (TreeInfo.skipParens(dt.tree).getTag()) {
2168 case LAMBDA:
2169 case REFERENCE:
2170 return dt;
2171 case CONDEXPR:
2172 return res == Type.recoveryType ?
2173 dt : res;
2174 }
2175 }
2176 return res;
2177 }
2178 }
2179 };
2180
2181 /** Check that sym is not an abstract method.
2182 */
2183 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
2184 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0)
2185 log.error(pos, "abstract.cant.be.accessed.directly",
2186 kindName(sym), sym, sym.location());
2187 }
2188
2189 /* ***************************************************************************
2190 * Debugging
2191 ****************************************************************************/
2192
2193 /** print all scopes starting with scope s and proceeding outwards.
2194 * used for debugging.
2195 */
2196 public void printscopes(Scope s) {
2197 while (s != null) {
2198 if (s.owner != null)
2199 System.err.print(s.owner + ": ");
2200 for (Scope.Entry e = s.elems; e != null; e = e.sibling) {
2201 if ((e.sym.flags() & ABSTRACT) != 0)
2202 System.err.print("abstract ");
2203 System.err.print(e.sym + " ");
2204 }
2205 System.err.println();
2206 s = s.next;
2207 }
2208 }
2209
2210 void printscopes(Env<AttrContext> env) {
2211 while (env.outer != null) {
2212 System.err.println("------------------------------");
2213 printscopes(env.info.scope);
2214 env = env.outer;
2215 }
2216 }
2217
2218 public void printscopes(Type t) {
2219 while (t.hasTag(CLASS)) {
2220 printscopes(t.tsym.members());
2221 t = types.supertype(t);
2222 }
2223 }
2224
2225 /* ***************************************************************************
2226 * Name resolution
2227 * Naming conventions are as for symbol lookup
2228 * Unlike the find... methods these methods will report access errors
2229 ****************************************************************************/
2230
2231 /** Resolve an unqualified (non-method) identifier.
2232 * @param pos The position to use for error reporting.
2233 * @param env The environment current at the identifier use.
2234 * @param name The identifier's name.
2235 * @param kind The set of admissible symbol kinds for the identifier.
2236 */
2237 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
2238 Name name, int kind) {
2239 return accessBase(
2240 findIdent(env, name, kind),
2241 pos, env.enclClass.sym.type, name, false);
2242 }
2243
2244 /** Resolve an unqualified method identifier.
2245 * @param pos The position to use for error reporting.
2246 * @param env The environment current at the method invocation.
2247 * @param name The identifier's name.
2248 * @param argtypes The types of the invocation's value arguments.
2249 * @param typeargtypes The types of the invocation's type arguments.
2250 */
2251 Symbol resolveMethod(DiagnosticPosition pos,
2252 Env<AttrContext> env,
2253 Name name,
2254 List<Type> argtypes,
2255 List<Type> typeargtypes) {
2256 return lookupMethod(env, pos, env.enclClass.sym, resolveMethodCheck,
2257 new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) {
2258 @Override
2259 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2260 return findFun(env, name, argtypes, typeargtypes,
2261 phase.isBoxingRequired(),
2262 phase.isVarargsRequired());
2263 }});
2264 }
2265
2266 /** Resolve a qualified method identifier
2267 * @param pos The position to use for error reporting.
2268 * @param env The environment current at the method invocation.
2269 * @param site The type of the qualifying expression, in which
2270 * identifier is searched.
2271 * @param name The identifier's name.
2272 * @param argtypes The types of the invocation's value arguments.
2273 * @param typeargtypes The types of the invocation's type arguments.
2274 */
2275 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2276 Type site, Name name, List<Type> argtypes,
2277 List<Type> typeargtypes) {
2278 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
2279 }
2280 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2281 Symbol location, Type site, Name name, List<Type> argtypes,
2282 List<Type> typeargtypes) {
2283 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
2284 }
2285 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
2286 DiagnosticPosition pos, Env<AttrContext> env,
2287 Symbol location, Type site, Name name, List<Type> argtypes,
2288 List<Type> typeargtypes) {
2289 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) {
2290 @Override
2291 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2292 return findMethod(env, site, name, argtypes, typeargtypes,
2293 phase.isBoxingRequired(),
2294 phase.isVarargsRequired(), false);
2295 }
2296 @Override
2297 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2298 if (sym.kind >= AMBIGUOUS) {
2299 sym = super.access(env, pos, location, sym);
2300 } else if (allowMethodHandles) {
2301 MethodSymbol msym = (MethodSymbol)sym;
2302 if (msym.isSignaturePolymorphic(types)) {
2303 return findPolymorphicSignatureInstance(env, sym, argtypes);
2304 }
2305 }
2306 return sym;
2307 }
2308 });
2309 }
2310
2311 /** Find or create an implicit method of exactly the given type (after erasure).
2312 * Searches in a side table, not the main scope of the site.
2313 * This emulates the lookup process required by JSR 292 in JVM.
2314 * @param env Attribution environment
2315 * @param spMethod signature polymorphic method - i.e. MH.invokeExact
2316 * @param argtypes The required argument types
2317 */
2318 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env,
2319 final Symbol spMethod,
2320 List<Type> argtypes) {
2321 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
2322 (MethodSymbol)spMethod, currentResolutionContext, argtypes);
2323 for (Symbol sym : polymorphicSignatureScope.getElementsByName(spMethod.name)) {
2324 if (types.isSameType(mtype, sym.type)) {
2325 return sym;
2326 }
2327 }
2328
2329 // create the desired method
2330 long flags = ABSTRACT | HYPOTHETICAL | spMethod.flags() & Flags.AccessFlags;
2331 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) {
2332 @Override
2333 public Symbol baseSymbol() {
2334 return spMethod;
2335 }
2336 };
2337 polymorphicSignatureScope.enter(msym);
2338 return msym;
2339 }
2340
2341 /** Resolve a qualified method identifier, throw a fatal error if not
2342 * found.
2343 * @param pos The position to use for error reporting.
2344 * @param env The environment current at the method invocation.
2345 * @param site The type of the qualifying expression, in which
2346 * identifier is searched.
2347 * @param name The identifier's name.
2348 * @param argtypes The types of the invocation's value arguments.
2349 * @param typeargtypes The types of the invocation's type arguments.
2350 */
2351 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
2352 Type site, Name name,
2353 List<Type> argtypes,
2354 List<Type> typeargtypes) {
2355 MethodResolutionContext resolveContext = new MethodResolutionContext();
2356 resolveContext.internalResolution = true;
2357 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
2358 site, name, argtypes, typeargtypes);
2359 if (sym.kind == MTH) return (MethodSymbol)sym;
2360 else throw new FatalError(
2361 diags.fragment("fatal.err.cant.locate.meth",
2362 name));
2363 }
2364
2365 /** Resolve constructor.
2366 * @param pos The position to use for error reporting.
2367 * @param env The environment current at the constructor invocation.
2368 * @param site The type of class for which a constructor is searched.
2369 * @param argtypes The types of the constructor invocation's value
2370 * arguments.
2371 * @param typeargtypes The types of the constructor invocation's type
2372 * arguments.
2373 */
2374 Symbol resolveConstructor(DiagnosticPosition pos,
2375 Env<AttrContext> env,
2376 Type site,
2377 List<Type> argtypes,
2378 List<Type> typeargtypes) {
2379 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
2380 }
2381
2382 private Symbol resolveConstructor(MethodResolutionContext resolveContext,
2383 final DiagnosticPosition pos,
2384 Env<AttrContext> env,
2385 Type site,
2386 List<Type> argtypes,
2387 List<Type> typeargtypes) {
2388 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2389 @Override
2390 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2391 return findConstructor(pos, env, site, argtypes, typeargtypes,
2392 phase.isBoxingRequired(),
2393 phase.isVarargsRequired());
2394 }
2395 });
2396 }
2397
2398 /** Resolve a constructor, throw a fatal error if not found.
2399 * @param pos The position to use for error reporting.
2400 * @param env The environment current at the method invocation.
2401 * @param site The type to be constructed.
2402 * @param argtypes The types of the invocation's value arguments.
2403 * @param typeargtypes The types of the invocation's type arguments.
2404 */
2405 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2406 Type site,
2407 List<Type> argtypes,
2408 List<Type> typeargtypes) {
2409 MethodResolutionContext resolveContext = new MethodResolutionContext();
2410 resolveContext.internalResolution = true;
2411 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
2412 if (sym.kind == MTH) return (MethodSymbol)sym;
2413 else throw new FatalError(
2414 diags.fragment("fatal.err.cant.locate.ctor", site));
2415 }
2416
2417 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2418 Type site, List<Type> argtypes,
2419 List<Type> typeargtypes,
2420 boolean allowBoxing,
2421 boolean useVarargs) {
2422 Symbol sym = findMethod(env, site,
2423 names.init, argtypes,
2424 typeargtypes, allowBoxing,
2425 useVarargs, false);
2426 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2427 return sym;
2428 }
2429
2430 /** Resolve constructor using diamond inference.
2431 * @param pos The position to use for error reporting.
2432 * @param env The environment current at the constructor invocation.
2433 * @param site The type of class for which a constructor is searched.
2434 * The scope of this class has been touched in attribution.
2435 * @param argtypes The types of the constructor invocation's value
2436 * arguments.
2437 * @param typeargtypes The types of the constructor invocation's type
2438 * arguments.
2439 */
2440 Symbol resolveDiamond(DiagnosticPosition pos,
2441 Env<AttrContext> env,
2442 Type site,
2443 List<Type> argtypes,
2444 List<Type> typeargtypes) {
2445 return lookupMethod(env, pos, site.tsym, resolveMethodCheck,
2446 new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2447 @Override
2448 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2449 return findDiamond(env, site, argtypes, typeargtypes,
2450 phase.isBoxingRequired(),
2451 phase.isVarargsRequired());
2452 }
2453 @Override
2454 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2455 if (sym.kind >= AMBIGUOUS) {
2456 final JCDiagnostic details = sym.kind == WRONG_MTH ?
2457 ((InapplicableSymbolError)sym).errCandidate().details :
2458 null;
2459 sym = new InapplicableSymbolError(sym.kind, "diamondError", currentResolutionContext) {
2460 @Override
2461 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
2462 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
2463 String key = details == null ?
2464 "cant.apply.diamond" :
2465 "cant.apply.diamond.1";
2466 return diags.create(dkind, log.currentSource(), pos, key,
2467 diags.fragment("diamond", site.tsym), details);
2468 }
2469 };
2470 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes);
2471 env.info.pendingResolutionPhase = currentResolutionContext.step;
2472 }
2473 return sym;
2474 }});
2475 }
2476
2477 /** This method scans all the constructor symbol in a given class scope -
2478 * assuming that the original scope contains a constructor of the kind:
2479 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
2480 * a method check is executed against the modified constructor type:
2481 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond
2482 * inference. The inferred return type of the synthetic constructor IS
2483 * the inferred type for the diamond operator.
2484 */
2485 private Symbol findDiamond(Env<AttrContext> env,
2486 Type site,
2487 List<Type> argtypes,
2488 List<Type> typeargtypes,
2489 boolean allowBoxing,
2490 boolean useVarargs) {
2491 Symbol bestSoFar = methodNotFound;
2492 for (Scope.Entry e = site.tsym.members().lookup(names.init);
2493 e.scope != null;
2494 e = e.next()) {
2495 final Symbol sym = e.sym;
2496 //- System.out.println(" e " + e.sym);
2497 if (sym.kind == MTH &&
2498 (sym.flags_field & SYNTHETIC) == 0) {
2499 List<Type> oldParams = e.sym.type.hasTag(FORALL) ?
2500 ((ForAll)sym.type).tvars :
2501 List.<Type>nil();
2502 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
2503 types.createMethodTypeWithReturn(sym.type.asMethodType(), site));
2504 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) {
2505 @Override
2506 public Symbol baseSymbol() {
2507 return sym;
2508 }
2509 };
2510 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
2511 newConstr,
2512 bestSoFar,
2513 allowBoxing,
2514 useVarargs,
2515 false);
2516 }
2517 }
2518 return bestSoFar;
2519 }
2520
2521
2522
2523 /** Resolve operator.
2524 * @param pos The position to use for error reporting.
2525 * @param optag The tag of the operation tree.
2526 * @param env The environment current at the operation.
2527 * @param argtypes The types of the operands.
2528 */
2529 Symbol resolveOperator(DiagnosticPosition pos, JCTree.Tag optag,
2530 Env<AttrContext> env, List<Type> argtypes) {
2531 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2532 try {
2533 currentResolutionContext = new MethodResolutionContext();
2534 Name name = treeinfo.operatorName(optag);
2535 env.info.pendingResolutionPhase = currentResolutionContext.step = BASIC;
2536 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
2537 null, false, false, true);
2538 if (boxingEnabled && sym.kind >= WRONG_MTHS)
2539 env.info.pendingResolutionPhase = currentResolutionContext.step = BOX;
2540 sym = findMethod(env, syms.predefClass.type, name, argtypes,
2541 null, true, false, true);
2542 return accessMethod(sym, pos, env.enclClass.sym.type, name,
2543 false, argtypes, null);
2544 }
2545 finally {
2546 currentResolutionContext = prevResolutionContext;
2547 }
2548 }
2549
2550 /** Resolve operator.
2551 * @param pos The position to use for error reporting.
2552 * @param optag The tag of the operation tree.
2553 * @param env The environment current at the operation.
2554 * @param arg The type of the operand.
2555 */
2556 Symbol resolveUnaryOperator(DiagnosticPosition pos, JCTree.Tag optag, Env<AttrContext> env, Type arg) {
2557 return resolveOperator(pos, optag, env, List.of(arg));
2558 }
2559
2560 /** Resolve binary operator.
2561 * @param pos The position to use for error reporting.
2562 * @param optag The tag of the operation tree.
2563 * @param env The environment current at the operation.
2564 * @param left The types of the left operand.
2565 * @param right The types of the right operand.
2566 */
2567 Symbol resolveBinaryOperator(DiagnosticPosition pos,
2568 JCTree.Tag optag,
2569 Env<AttrContext> env,
2570 Type left,
2571 Type right) {
2572 return resolveOperator(pos, optag, env, List.of(left, right));
2573 }
2574
2575 /**
2576 * Resolution of member references is typically done as a single
2577 * overload resolution step, where the argument types A are inferred from
2578 * the target functional descriptor.
2579 *
2580 * If the member reference is a method reference with a type qualifier,
2581 * a two-step lookup process is performed. The first step uses the
2582 * expected argument list A, while the second step discards the first
2583 * type from A (which is treated as a receiver type).
2584 *
2585 * There are two cases in which inference is performed: (i) if the member
2586 * reference is a constructor reference and the qualifier type is raw - in
2587 * which case diamond inference is used to infer a parameterization for the
2588 * type qualifier; (ii) if the member reference is an unbound reference
2589 * where the type qualifier is raw - in that case, during the unbound lookup
2590 * the receiver argument type is used to infer an instantiation for the raw
2591 * qualifier type.
2592 *
2593 * When a multi-step resolution process is exploited, it is an error
2594 * if two candidates are found (ambiguity).
2595 *
2596 * This routine returns a pair (T,S), where S is the member reference symbol,
2597 * and T is the type of the class in which S is defined. This is necessary as
2598 * the type T might be dynamically inferred (i.e. if constructor reference
2599 * has a raw qualifier).
2600 */
2601 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(DiagnosticPosition pos,
2602 Env<AttrContext> env,
2603 JCMemberReference referenceTree,
2604 Type site,
2605 Name name, List<Type> argtypes,
2606 List<Type> typeargtypes,
2607 boolean boxingAllowed,
2608 MethodCheck methodCheck) {
2609 MethodResolutionPhase maxPhase = boxingAllowed ? VARARITY : BASIC;
2610
2611 ReferenceLookupHelper boundLookupHelper;
2612 if (!name.equals(names.init)) {
2613 //method reference
2614 boundLookupHelper =
2615 new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2616 } else if (site.hasTag(ARRAY)) {
2617 //array constructor reference
2618 boundLookupHelper =
2619 new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2620 } else {
2621 //class constructor reference
2622 boundLookupHelper =
2623 new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2624 }
2625
2626 //step 1 - bound lookup
2627 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup());
2628 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(), site.tsym, methodCheck, boundLookupHelper);
2629
2630 //step 2 - unbound lookup
2631 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup();
2632 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup());
2633 Symbol unboundSym = lookupMethod(unboundEnv, env.tree.pos(), site.tsym, methodCheck, unboundLookupHelper);
2634
2635 //merge results
2636 Pair<Symbol, ReferenceLookupHelper> res;
2637 if (!lookupSuccess(unboundSym)) {
2638 res = new Pair<Symbol, ReferenceLookupHelper>(boundSym, boundLookupHelper);
2639 env.info.pendingResolutionPhase = boundEnv.info.pendingResolutionPhase;
2640 } else if (lookupSuccess(boundSym)) {
2641 res = new Pair<Symbol, ReferenceLookupHelper>(ambiguityError(boundSym, unboundSym), boundLookupHelper);
2642 env.info.pendingResolutionPhase = boundEnv.info.pendingResolutionPhase;
2643 } else {
2644 res = new Pair<Symbol, ReferenceLookupHelper>(unboundSym, unboundLookupHelper);
2645 env.info.pendingResolutionPhase = unboundEnv.info.pendingResolutionPhase;
2646 }
2647
2648 return res;
2649 }
2650 //private
2651 boolean lookupSuccess(Symbol s) {
2652 return s.kind == MTH || s.kind == AMBIGUOUS;
2653 }
2654
2655 /**
2656 * Helper for defining custom method-like lookup logic; a lookup helper
2657 * provides hooks for (i) the actual lookup logic and (ii) accessing the
2658 * lookup result (this step might result in compiler diagnostics to be generated)
2659 */
2660 abstract class LookupHelper {
2661
2662 /** name of the symbol to lookup */
2663 Name name;
2664
2665 /** location in which the lookup takes place */
2666 Type site;
2667
2668 /** actual types used during the lookup */
2669 List<Type> argtypes;
2670
2671 /** type arguments used during the lookup */
2672 List<Type> typeargtypes;
2673
2674 /** Max overload resolution phase handled by this helper */
2675 MethodResolutionPhase maxPhase;
2676
2677 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2678 this.name = name;
2679 this.site = site;
2680 this.argtypes = argtypes;
2681 this.typeargtypes = typeargtypes;
2682 this.maxPhase = maxPhase;
2683 }
2684
2685 /**
2686 * Should lookup stop at given phase with given result
2687 */
2688 protected boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
2689 return phase.ordinal() > maxPhase.ordinal() ||
2690 sym.kind < ERRONEOUS || sym.kind == AMBIGUOUS;
2691 }
2692
2693 /**
2694 * Search for a symbol under a given overload resolution phase - this method
2695 * is usually called several times, once per each overload resolution phase
2696 */
2697 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase);
2698
2699 /**
2700 * Validate the result of the lookup
2701 */
2702 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym);
2703 }
2704
2705 abstract class BasicLookupHelper extends LookupHelper {
2706
2707 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) {
2708 super(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY);
2709 }
2710
2711 @Override
2712 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2713 if (sym.kind == AMBIGUOUS) {
2714 AmbiguityError a_err = (AmbiguityError)sym;
2715 sym = a_err.mergeAbstracts(site);
2716 }
2717 if (sym.kind >= AMBIGUOUS) {
2718 //if nothing is found return the 'first' error
2719 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes);
2720 }
2721 return sym;
2722 }
2723 }
2724
2725 /**
2726 * Helper class for member reference lookup. A reference lookup helper
2727 * defines the basic logic for member reference lookup; a method gives
2728 * access to an 'unbound' helper used to perform an unbound member
2729 * reference lookup.
2730 */
2731 abstract class ReferenceLookupHelper extends LookupHelper {
2732
2733 /** The member reference tree */
2734 JCMemberReference referenceTree;
2735
2736 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2737 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2738 super(name, site, argtypes, typeargtypes, maxPhase);
2739 this.referenceTree = referenceTree;
2740
2741 }
2742
2743 /**
2744 * Returns an unbound version of this lookup helper. By default, this
2745 * method returns an dummy lookup helper.
2746 */
2747 ReferenceLookupHelper unboundLookup() {
2748 //dummy loopkup helper that always return 'methodNotFound'
2749 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) {
2750 @Override
2751 ReferenceLookupHelper unboundLookup() {
2752 return this;
2753 }
2754 @Override
2755 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2756 return methodNotFound;
2757 }
2758 @Override
2759 ReferenceKind referenceKind(Symbol sym) {
2760 Assert.error();
2761 return null;
2762 }
2763 };
2764 }
2765
2766 /**
2767 * Get the kind of the member reference
2768 */
2769 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym);
2770
2771 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2772 if (sym.kind == AMBIGUOUS) {
2773 AmbiguityError a_err = (AmbiguityError)sym;
2774 sym = a_err.mergeAbstracts(site);
2775 }
2776 //skip error reporting
2777 return sym;
2778 }
2779 }
2780
2781 /**
2782 * Helper class for method reference lookup. The lookup logic is based
2783 * upon Resolve.findMethod; in certain cases, this helper class has a
2784 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper).
2785 * In such cases, non-static lookup results are thrown away.
2786 */
2787 class MethodReferenceLookupHelper extends ReferenceLookupHelper {
2788
2789 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2790 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2791 super(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2792 }
2793
2794 @Override
2795 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2796 return findMethod(env, site, name, argtypes, typeargtypes,
2797 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
2798 }
2799
2800 @Override
2801 ReferenceLookupHelper unboundLookup() {
2802 if (TreeInfo.isStaticSelector(referenceTree.expr, names) &&
2803 argtypes.nonEmpty() &&
2804 (argtypes.head.hasTag(NONE) || types.isSubtypeUnchecked(argtypes.head, site))) {
2805 return new UnboundMethodReferenceLookupHelper(referenceTree, name,
2806 site, argtypes, typeargtypes, maxPhase);
2807 } else {
2808 return super.unboundLookup();
2809 }
2810 }
2811
2812 @Override
2813 ReferenceKind referenceKind(Symbol sym) {
2814 if (sym.isStatic()) {
2815 return ReferenceKind.STATIC;
2816 } else {
2817 Name selName = TreeInfo.name(referenceTree.getQualifierExpression());
2818 return selName != null && selName == names._super ?
2819 ReferenceKind.SUPER :
2820 ReferenceKind.BOUND;
2821 }
2822 }
2823 }
2824
2825 /**
2826 * Helper class for unbound method reference lookup. Essentially the same
2827 * as the basic method reference lookup helper; main difference is that static
2828 * lookup results are thrown away. If qualifier type is raw, an attempt to
2829 * infer a parameterized type is made using the first actual argument (that
2830 * would otherwise be ignored during the lookup).
2831 */
2832 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper {
2833
2834 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2835 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2836 super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase);
2837 if (site.isRaw() && !argtypes.head.hasTag(NONE)) {
2838 Type asSuperSite = types.asSuper(argtypes.head, site.tsym);
2839 this.site = asSuperSite;
2840 }
2841 }
2842
2843 @Override
2844 ReferenceLookupHelper unboundLookup() {
2845 return this;
2846 }
2847
2848 @Override
2849 ReferenceKind referenceKind(Symbol sym) {
2850 return ReferenceKind.UNBOUND;
2851 }
2852 }
2853
2854 /**
2855 * Helper class for array constructor lookup; an array constructor lookup
2856 * is simulated by looking up a method that returns the array type specified
2857 * as qualifier, and that accepts a single int parameter (size of the array).
2858 */
2859 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper {
2860
2861 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
2862 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2863 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
2864 }
2865
2866 @Override
2867 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2868 Scope sc = new Scope(syms.arrayClass);
2869 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym);
2870 arrayConstr.type = new MethodType(List.of(syms.intType), site, List.<Type>nil(), syms.methodClass);
2871 sc.enter(arrayConstr);
2872 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false, false);
2873 }
2874
2875 @Override
2876 ReferenceKind referenceKind(Symbol sym) {
2877 return ReferenceKind.ARRAY_CTOR;
2878 }
2879 }
2880
2881 /**
2882 * Helper class for constructor reference lookup. The lookup logic is based
2883 * upon either Resolve.findMethod or Resolve.findDiamond - depending on
2884 * whether the constructor reference needs diamond inference (this is the case
2885 * if the qualifier type is raw). A special erroneous symbol is returned
2886 * if the lookup returns the constructor of an inner class and there's no
2887 * enclosing instance in scope.
2888 */
2889 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper {
2890
2891 boolean needsInference;
2892
2893 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
2894 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2895 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
2896 if (site.isRaw()) {
2897 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym);
2898 needsInference = true;
2899 }
2900 }
2901
2902 @Override
2903 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2904 Symbol sym = needsInference ?
2905 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) :
2906 findMethod(env, site, name, argtypes, typeargtypes,
2907 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
2908 return sym.kind != MTH ||
2909 site.getEnclosingType().hasTag(NONE) ||
2910 hasEnclosingInstance(env, site) ?
2911 sym : new InvalidSymbolError(Kinds.MISSING_ENCL, sym, null) {
2912 @Override
2913 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
2914 return diags.create(dkind, log.currentSource(), pos,
2915 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType());
2916 }
2917 };
2918 }
2919
2920 @Override
2921 ReferenceKind referenceKind(Symbol sym) {
2922 return site.getEnclosingType().hasTag(NONE) ?
2923 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER;
2924 }
2925 }
2926
2927 /**
2928 * Main overload resolution routine. On each overload resolution step, a
2929 * lookup helper class is used to perform the method/constructor lookup;
2930 * at the end of the lookup, the helper is used to validate the results
2931 * (this last step might trigger overload resolution diagnostics).
2932 */
2933 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, MethodCheck methodCheck, LookupHelper lookupHelper) {
2934 MethodResolutionContext resolveContext = new MethodResolutionContext();
2935 resolveContext.methodCheck = methodCheck;
2936 return lookupMethod(env, pos, location, resolveContext, lookupHelper);
2937 }
2938
2939 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location,
2940 MethodResolutionContext resolveContext, LookupHelper lookupHelper) {
2941 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2942 try {
2943 Symbol bestSoFar = methodNotFound;
2944 currentResolutionContext = resolveContext;
2945 for (MethodResolutionPhase phase : methodResolutionSteps) {
2946 if (!phase.isApplicable(boxingEnabled, varargsEnabled) ||
2947 lookupHelper.shouldStop(bestSoFar, phase)) break;
2948 MethodResolutionPhase prevPhase = currentResolutionContext.step;
2949 Symbol prevBest = bestSoFar;
2950 currentResolutionContext.step = phase;
2951 bestSoFar = phase.mergeResults(bestSoFar, lookupHelper.lookup(env, phase));
2952 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase;
2953 }
2954 return lookupHelper.access(env, pos, location, bestSoFar);
2955 } finally {
2956 currentResolutionContext = prevResolutionContext;
2957 }
2958 }
2959
2960 /**
2961 * Resolve `c.name' where name == this or name == super.
2962 * @param pos The position to use for error reporting.
2963 * @param env The environment current at the expression.
2964 * @param c The qualifier.
2965 * @param name The identifier's name.
2966 */
2967 Symbol resolveSelf(DiagnosticPosition pos,
2968 Env<AttrContext> env,
2969 TypeSymbol c,
2970 Name name) {
2971 Env<AttrContext> env1 = env;
2972 boolean staticOnly = false;
2973 while (env1.outer != null) {
2974 if (isStatic(env1)) staticOnly = true;
2975 if (env1.enclClass.sym == c) {
2976 Symbol sym = env1.info.scope.lookup(name).sym;
2977 if (sym != null) {
2978 if (staticOnly) sym = new StaticError(sym);
2979 return accessBase(sym, pos, env.enclClass.sym.type,
2980 name, true);
2981 }
2982 }
2983 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
2984 env1 = env1.outer;
2985 }
2986 if (allowDefaultMethods && c.isInterface() &&
2987 name == names._super && !isStatic(env) &&
2988 types.isDirectSuperInterface(c, env.enclClass.sym)) {
2989 //this might be a default super call if one of the superinterfaces is 'c'
2990 for (Type t : pruneInterfaces(env.enclClass.type)) {
2991 if (t.tsym == c) {
2992 env.info.defaultSuperCallSite = t;
2993 return new VarSymbol(0, names._super,
2994 types.asSuper(env.enclClass.type, c), env.enclClass.sym);
2995 }
2996 }
2997 //find a direct superinterface that is a subtype of 'c'
2998 for (Type i : types.interfaces(env.enclClass.type)) {
2999 if (i.tsym.isSubClass(c, types) && i.tsym != c) {
3000 log.error(pos, "illegal.default.super.call", c,
3001 diags.fragment("redundant.supertype", c, i));
3002 return syms.errSymbol;
3003 }
3004 }
3005 Assert.error();
3006 }
3007 log.error(pos, "not.encl.class", c);
3008 return syms.errSymbol;
3009 }
3010 //where
3011 private List<Type> pruneInterfaces(Type t) {
3012 ListBuffer<Type> result = ListBuffer.lb();
3013 for (Type t1 : types.interfaces(t)) {
3014 boolean shouldAdd = true;
3015 for (Type t2 : types.interfaces(t)) {
3016 if (t1 != t2 && types.isSubtypeNoCapture(t2, t1)) {
3017 shouldAdd = false;
3018 }
3019 }
3020 if (shouldAdd) {
3021 result.append(t1);
3022 }
3023 }
3024 return result.toList();
3025 }
3026
3027
3028 /**
3029 * Resolve `c.this' for an enclosing class c that contains the
3030 * named member.
3031 * @param pos The position to use for error reporting.
3032 * @param env The environment current at the expression.
3033 * @param member The member that must be contained in the result.
3034 */
3035 Symbol resolveSelfContaining(DiagnosticPosition pos,
3036 Env<AttrContext> env,
3037 Symbol member,
3038 boolean isSuperCall) {
3039 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall);
3040 if (sym == null) {
3041 log.error(pos, "encl.class.required", member);
3042 return syms.errSymbol;
3043 } else {
3044 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true);
3045 }
3046 }
3047
3048 boolean hasEnclosingInstance(Env<AttrContext> env, Type type) {
3049 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false);
3050 return encl != null && encl.kind < ERRONEOUS;
3051 }
3052
3053 private Symbol resolveSelfContainingInternal(Env<AttrContext> env,
3054 Symbol member,
3055 boolean isSuperCall) {
3056 Name name = names._this;
3057 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
3058 boolean staticOnly = false;
3059 if (env1 != null) {
3060 while (env1 != null && env1.outer != null) {
3061 if (isStatic(env1)) staticOnly = true;
3062 if (env1.enclClass.sym.isSubClass(member.owner, types)) {
3063 Symbol sym = env1.info.scope.lookup(name).sym;
3064 if (sym != null) {
3065 if (staticOnly) sym = new StaticError(sym);
3066 return sym;
3067 }
3068 }
3069 if ((env1.enclClass.sym.flags() & STATIC) != 0)
3070 staticOnly = true;
3071 env1 = env1.outer;
3072 }
3073 }
3074 return null;
3075 }
3076
3077 /**
3078 * Resolve an appropriate implicit this instance for t's container.
3079 * JLS 8.8.5.1 and 15.9.2
3080 */
3081 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
3082 return resolveImplicitThis(pos, env, t, false);
3083 }
3084
3085 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
3086 Type thisType = (((t.tsym.owner.kind & (MTH|VAR)) != 0)
3087 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
3088 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
3089 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym)
3090 log.error(pos, "cant.ref.before.ctor.called", "this");
3091 return thisType;
3092 }
3093
3094 /* ***************************************************************************
3095 * ResolveError classes, indicating error situations when accessing symbols
3096 ****************************************************************************/
3097
3098 //used by TransTypes when checking target type of synthetic cast
3099 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) {
3100 AccessError error = new AccessError(env, env.enclClass.type, type.tsym);
3101 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null);
3102 }
3103 //where
3104 private void logResolveError(ResolveError error,
3105 DiagnosticPosition pos,
3106 Symbol location,
3107 Type site,
3108 Name name,
3109 List<Type> argtypes,
3110 List<Type> typeargtypes) {
3111 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
3112 pos, location, site, name, argtypes, typeargtypes);
3113 if (d != null) {
3114 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
3115 log.report(d);
3116 }
3117 }
3118
3119 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
3120
3121 public Object methodArguments(List<Type> argtypes) {
3122 if (argtypes == null || argtypes.isEmpty()) {
3123 return noArgs;
3124 } else {
3125 ListBuffer<Object> diagArgs = ListBuffer.lb();
3126 for (Type t : argtypes) {
3127 if (t.hasTag(DEFERRED)) {
3128 diagArgs.append(((DeferredAttr.DeferredType)t).tree);
3129 } else {
3130 diagArgs.append(t);
3131 }
3132 }
3133 return diagArgs;
3134 }
3135 }
3136
3137 /**
3138 * Root class for resolution errors. Subclass of ResolveError
3139 * represent a different kinds of resolution error - as such they must
3140 * specify how they map into concrete compiler diagnostics.
3141 */
3142 abstract class ResolveError extends Symbol {
3143
3144 /** The name of the kind of error, for debugging only. */
3145 final String debugName;
3146
3147 ResolveError(int kind, String debugName) {
3148 super(kind, 0, null, null, null);
3149 this.debugName = debugName;
3150 }
3151
3152 @Override
3153 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
3154 throw new AssertionError();
3155 }
3156
3157 @Override
3158 public String toString() {
3159 return debugName;
3160 }
3161
3162 @Override
3163 public boolean exists() {
3164 return false;
3165 }
3166
3167 /**
3168 * Create an external representation for this erroneous symbol to be
3169 * used during attribution - by default this returns the symbol of a
3170 * brand new error type which stores the original type found
3171 * during resolution.
3172 *
3173 * @param name the name used during resolution
3174 * @param location the location from which the symbol is accessed
3175 */
3176 protected Symbol access(Name name, TypeSymbol location) {
3177 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3178 }
3179
3180 /**
3181 * Create a diagnostic representing this resolution error.
3182 *
3183 * @param dkind The kind of the diagnostic to be created (e.g error).
3184 * @param pos The position to be used for error reporting.
3185 * @param site The original type from where the selection took place.
3186 * @param name The name of the symbol to be resolved.
3187 * @param argtypes The invocation's value arguments,
3188 * if we looked for a method.
3189 * @param typeargtypes The invocation's type arguments,
3190 * if we looked for a method.
3191 */
3192 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3193 DiagnosticPosition pos,
3194 Symbol location,
3195 Type site,
3196 Name name,
3197 List<Type> argtypes,
3198 List<Type> typeargtypes);
3199 }
3200
3201 /**
3202 * This class is the root class of all resolution errors caused by
3203 * an invalid symbol being found during resolution.
3204 */
3205 abstract class InvalidSymbolError extends ResolveError {
3206
3207 /** The invalid symbol found during resolution */
3208 Symbol sym;
3209
3210 InvalidSymbolError(int kind, Symbol sym, String debugName) {
3211 super(kind, debugName);
3212 this.sym = sym;
3213 }
3214
3215 @Override
3216 public boolean exists() {
3217 return true;
3218 }
3219
3220 @Override
3221 public String toString() {
3222 return super.toString() + " wrongSym=" + sym;
3223 }
3224
3225 @Override
3226 public Symbol access(Name name, TypeSymbol location) {
3227 if ((sym.kind & ERRONEOUS) == 0 && (sym.kind & TYP) != 0)
3228 return types.createErrorType(name, location, sym.type).tsym;
3229 else
3230 return sym;
3231 }
3232 }
3233
3234 /**
3235 * InvalidSymbolError error class indicating that a symbol matching a
3236 * given name does not exists in a given site.
3237 */
3238 class SymbolNotFoundError extends ResolveError {
3239
3240 SymbolNotFoundError(int kind) {
3241 super(kind, "symbol not found error");
3242 }
3243
3244 @Override
3245 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3246 DiagnosticPosition pos,
3247 Symbol location,
3248 Type site,
3249 Name name,
3250 List<Type> argtypes,
3251 List<Type> typeargtypes) {
3252 argtypes = argtypes == null ? List.<Type>nil() : argtypes;
3253 typeargtypes = typeargtypes == null ? List.<Type>nil() : typeargtypes;
3254 if (name == names.error)
3255 return null;
3256
3257 if (syms.operatorNames.contains(name)) {
3258 boolean isUnaryOp = argtypes.size() == 1;
3259 String key = argtypes.size() == 1 ?
3260 "operator.cant.be.applied" :
3261 "operator.cant.be.applied.1";
3262 Type first = argtypes.head;
3263 Type second = !isUnaryOp ? argtypes.tail.head : null;
3264 return diags.create(dkind, log.currentSource(), pos,
3265 key, name, first, second);
3266 }
3267 boolean hasLocation = false;
3268 if (location == null) {
3269 location = site.tsym;
3270 }
3271 if (!location.name.isEmpty()) {
3272 if (location.kind == PCK && !site.tsym.exists()) {
3273 return diags.create(dkind, log.currentSource(), pos,
3274 "doesnt.exist", location);
3275 }
3276 hasLocation = !location.name.equals(names._this) &&
3277 !location.name.equals(names._super);
3278 }
3279 boolean isConstructor = kind == ABSENT_MTH && name == names.init;
3280 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : absentKind(kind);
3281 Name idname = isConstructor ? site.tsym.name : name;
3282 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
3283 if (hasLocation) {
3284 return diags.create(dkind, log.currentSource(), pos,
3285 errKey, kindname, idname, //symbol kindname, name
3286 typeargtypes, args(argtypes), //type parameters and arguments (if any)
3287 getLocationDiag(location, site)); //location kindname, type
3288 }
3289 else {
3290 return diags.create(dkind, log.currentSource(), pos,
3291 errKey, kindname, idname, //symbol kindname, name
3292 typeargtypes, args(argtypes)); //type parameters and arguments (if any)
3293 }
3294 }
3295 //where
3296 private Object args(List<Type> args) {
3297 return args.isEmpty() ? args : methodArguments(args);
3298 }
3299
3300 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
3301 String key = "cant.resolve";
3302 String suffix = hasLocation ? ".location" : "";
3303 switch (kindname) {
3304 case METHOD:
3305 case CONSTRUCTOR: {
3306 suffix += ".args";
3307 suffix += hasTypeArgs ? ".params" : "";
3308 }
3309 }
3310 return key + suffix;
3311 }
3312 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
3313 if (location.kind == VAR) {
3314 return diags.fragment("location.1",
3315 kindName(location),
3316 location,
3317 location.type);
3318 } else {
3319 return diags.fragment("location",
3320 typeKindName(site),
3321 site,
3322 null);
3323 }
3324 }
3325 }
3326
3327 /**
3328 * InvalidSymbolError error class indicating that a given symbol
3329 * (either a method, a constructor or an operand) is not applicable
3330 * given an actual arguments/type argument list.
3331 */
3332 class InapplicableSymbolError extends ResolveError {
3333
3334 protected MethodResolutionContext resolveContext;
3335
3336 InapplicableSymbolError(MethodResolutionContext context) {
3337 this(WRONG_MTH, "inapplicable symbol error", context);
3338 }
3339
3340 protected InapplicableSymbolError(int kind, String debugName, MethodResolutionContext context) {
3341 super(kind, debugName);
3342 this.resolveContext = context;
3343 }
3344
3345 @Override
3346 public String toString() {
3347 return super.toString();
3348 }
3349
3350 @Override
3351 public boolean exists() {
3352 return true;
3353 }
3354
3355 @Override
3356 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3357 DiagnosticPosition pos,
3358 Symbol location,
3359 Type site,
3360 Name name,
3361 List<Type> argtypes,
3362 List<Type> typeargtypes) {
3363 if (name == names.error)
3364 return null;
3365
3366 if (syms.operatorNames.contains(name)) {
3367 boolean isUnaryOp = argtypes.size() == 1;
3368 String key = argtypes.size() == 1 ?
3369 "operator.cant.be.applied" :
3370 "operator.cant.be.applied.1";
3371 Type first = argtypes.head;
3372 Type second = !isUnaryOp ? argtypes.tail.head : null;
3373 return diags.create(dkind, log.currentSource(), pos,
3374 key, name, first, second);
3375 }
3376 else {
3377 Candidate c = errCandidate();
3378 Symbol ws = c.sym.asMemberOf(site, types);
3379 return diags.create(dkind, log.currentSource(), pos,
3380 "cant.apply.symbol",
3381 kindName(ws),
3382 ws.name == names.init ? ws.owner.name : ws.name,
3383 methodArguments(ws.type.getParameterTypes()),
3384 methodArguments(argtypes),
3385 kindName(ws.owner),
3386 ws.owner.type,
3387 c.details);
3388 }
3389 }
3390
3391 @Override
3392 public Symbol access(Name name, TypeSymbol location) {
3393 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3394 }
3395
3396 private Candidate errCandidate() {
3397 Candidate bestSoFar = null;
3398 for (Candidate c : resolveContext.candidates) {
3399 if (c.isApplicable()) continue;
3400 bestSoFar = c;
3401 }
3402 Assert.checkNonNull(bestSoFar);
3403 return bestSoFar;
3404 }
3405 }
3406
3407 /**
3408 * ResolveError error class indicating that a set of symbols
3409 * (either methods, constructors or operands) is not applicable
3410 * given an actual arguments/type argument list.
3411 */
3412 class InapplicableSymbolsError extends InapplicableSymbolError {
3413
3414 InapplicableSymbolsError(MethodResolutionContext context) {
3415 super(WRONG_MTHS, "inapplicable symbols", context);
3416 }
3417
3418 @Override
3419 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3420 DiagnosticPosition pos,
3421 Symbol location,
3422 Type site,
3423 Name name,
3424 List<Type> argtypes,
3425 List<Type> typeargtypes) {
3426 if (!resolveContext.candidates.isEmpty()) {
3427 JCDiagnostic err = diags.create(dkind,
3428 log.currentSource(),
3429 pos,
3430 "cant.apply.symbols",
3431 name == names.init ? KindName.CONSTRUCTOR : absentKind(kind),
3432 name == names.init ? site.tsym.name : name,
3433 methodArguments(argtypes));
3434 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(site));
3435 } else {
3436 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
3437 location, site, name, argtypes, typeargtypes);
3438 }
3439 }
3440
3441 //where
3442 List<JCDiagnostic> candidateDetails(Type site) {
3443 Map<Symbol, JCDiagnostic> details = new LinkedHashMap<Symbol, JCDiagnostic>();
3444 for (Candidate c : resolveContext.candidates) {
3445 if (c.isApplicable()) continue;
3446 JCDiagnostic detailDiag = diags.fragment("inapplicable.method",
3447 Kinds.kindName(c.sym),
3448 c.sym.location(site, types),
3449 c.sym.asMemberOf(site, types),
3450 c.details);
3451 details.put(c.sym, detailDiag);
3452 }
3453 return List.from(details.values());
3454 }
3455 }
3456
3457 /**
3458 * An InvalidSymbolError error class indicating that a symbol is not
3459 * accessible from a given site
3460 */
3461 class AccessError extends InvalidSymbolError {
3462
3463 private Env<AttrContext> env;
3464 private Type site;
3465
3466 AccessError(Symbol sym) {
3467 this(null, null, sym);
3468 }
3469
3470 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
3471 super(HIDDEN, sym, "access error");
3472 this.env = env;
3473 this.site = site;
3474 if (debugResolve)
3475 log.error("proc.messager", sym + " @ " + site + " is inaccessible.");
3476 }
3477
3478 @Override
3479 public boolean exists() {
3480 return false;
3481 }
3482
3483 @Override
3484 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3485 DiagnosticPosition pos,
3486 Symbol location,
3487 Type site,
3488 Name name,
3489 List<Type> argtypes,
3490 List<Type> typeargtypes) {
3491 if (sym.owner.type.hasTag(ERROR))
3492 return null;
3493
3494 if (sym.name == names.init && sym.owner != site.tsym) {
3495 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
3496 pos, location, site, name, argtypes, typeargtypes);
3497 }
3498 else if ((sym.flags() & PUBLIC) != 0
3499 || (env != null && this.site != null
3500 && !isAccessible(env, this.site))) {
3501 return diags.create(dkind, log.currentSource(),
3502 pos, "not.def.access.class.intf.cant.access",
3503 sym, sym.location());
3504 }
3505 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
3506 return diags.create(dkind, log.currentSource(),
3507 pos, "report.access", sym,
3508 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
3509 sym.location());
3510 }
3511 else {
3512 return diags.create(dkind, log.currentSource(),
3513 pos, "not.def.public.cant.access", sym, sym.location());
3514 }
3515 }
3516 }
3517
3518 /**
3519 * InvalidSymbolError error class indicating that an instance member
3520 * has erroneously been accessed from a static context.
3521 */
3522 class StaticError extends InvalidSymbolError {
3523
3524 StaticError(Symbol sym) {
3525 super(STATICERR, sym, "static error");
3526 }
3527
3528 @Override
3529 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3530 DiagnosticPosition pos,
3531 Symbol location,
3532 Type site,
3533 Name name,
3534 List<Type> argtypes,
3535 List<Type> typeargtypes) {
3536 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS))
3537 ? types.erasure(sym.type).tsym
3538 : sym);
3539 return diags.create(dkind, log.currentSource(), pos,
3540 "non-static.cant.be.ref", kindName(sym), errSym);
3541 }
3542 }
3543
3544 /**
3545 * InvalidSymbolError error class indicating that a pair of symbols
3546 * (either methods, constructors or operands) are ambiguous
3547 * given an actual arguments/type argument list.
3548 */
3549 class AmbiguityError extends ResolveError {
3550
3551 /** The other maximally specific symbol */
3552 List<Symbol> ambiguousSyms = List.nil();
3553
3554 @Override
3555 public boolean exists() {
3556 return true;
3557 }
3558
3559 AmbiguityError(Symbol sym1, Symbol sym2) {
3560 super(AMBIGUOUS, "ambiguity error");
3561 ambiguousSyms = flatten(sym2).appendList(flatten(sym1));
3562 }
3563
3564 private List<Symbol> flatten(Symbol sym) {
3565 if (sym.kind == AMBIGUOUS) {
3566 return ((AmbiguityError)sym).ambiguousSyms;
3567 } else {
3568 return List.of(sym);
3569 }
3570 }
3571
3572 AmbiguityError addAmbiguousSymbol(Symbol s) {
3573 ambiguousSyms = ambiguousSyms.prepend(s);
3574 return this;
3575 }
3576
3577 @Override
3578 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3579 DiagnosticPosition pos,
3580 Symbol location,
3581 Type site,
3582 Name name,
3583 List<Type> argtypes,
3584 List<Type> typeargtypes) {
3585 List<Symbol> diagSyms = ambiguousSyms.reverse();
3586 Symbol s1 = diagSyms.head;
3587 Symbol s2 = diagSyms.tail.head;
3588 Name sname = s1.name;
3589 if (sname == names.init) sname = s1.owner.name;
3590 return diags.create(dkind, log.currentSource(),
3591 pos, "ref.ambiguous", sname,
3592 kindName(s1),
3593 s1,
3594 s1.location(site, types),
3595 kindName(s2),
3596 s2,
3597 s2.location(site, types));
3598 }
3599
3600 /**
3601 * If multiple applicable methods are found during overload and none of them
3602 * is more specific than the others, attempt to merge their signatures.
3603 */
3604 Symbol mergeAbstracts(Type site) {
3605 Symbol fst = ambiguousSyms.last();
3606 Symbol res = fst;
3607 for (Symbol s : ambiguousSyms.reverse()) {
3608 Type mt1 = types.memberType(site, res);
3609 Type mt2 = types.memberType(site, s);
3610 if ((s.flags() & ABSTRACT) == 0 ||
3611 !types.overrideEquivalent(mt1, mt2) ||
3612 !types.isSameTypes(fst.erasure(types).getParameterTypes(),
3613 s.erasure(types).getParameterTypes())) {
3614 //ambiguity cannot be resolved
3615 return this;
3616 } else {
3617 Type mst = mostSpecificReturnType(mt1, mt2);
3618 if (mst == null) {
3619 // Theoretically, this can't happen, but it is possible
3620 // due to error recovery or mixing incompatible class files
3621 return this;
3622 }
3623 Symbol mostSpecific = mst == mt1 ? res : s;
3624 List<Type> allThrown = chk.intersect(mt1.getThrownTypes(), mt2.getThrownTypes());
3625 Type newSig = types.createMethodTypeWithThrown(mostSpecific.type, allThrown);
3626 res = new MethodSymbol(
3627 mostSpecific.flags(),
3628 mostSpecific.name,
3629 newSig,
3630 mostSpecific.owner);
3631 }
3632 }
3633 return res;
3634 }
3635
3636 @Override
3637 protected Symbol access(Name name, TypeSymbol location) {
3638 Symbol firstAmbiguity = ambiguousSyms.last();
3639 return firstAmbiguity.kind == TYP ?
3640 types.createErrorType(name, location, firstAmbiguity.type).tsym :
3641 firstAmbiguity;
3642 }
3643 }
3644
3645 class BadVarargsMethod extends ResolveError {
3646
3647 ResolveError delegatedError;
3648
3649 BadVarargsMethod(ResolveError delegatedError) {
3650 super(delegatedError.kind, "badVarargs");
3651 this.delegatedError = delegatedError;
3652 }
3653
3654 @Override
3655 public Symbol baseSymbol() {
3656 return delegatedError.baseSymbol();
3657 }
3658
3659 @Override
3660 protected Symbol access(Name name, TypeSymbol location) {
3661 return delegatedError.access(name, location);
3662 }
3663
3664 @Override
3665 public boolean exists() {
3666 return true;
3667 }
3668
3669 @Override
3670 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
3671 return delegatedError.getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes);
3672 }
3673 }
3674
3675 enum MethodResolutionPhase {
3676 BASIC(false, false),
3677 BOX(true, false),
3678 VARARITY(true, true) {
3679 @Override
3680 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) {
3681 switch (sym.kind) {
3682 case WRONG_MTH:
3683 return (bestSoFar.kind == WRONG_MTH || bestSoFar.kind == WRONG_MTHS) ?
3684 bestSoFar :
3685 sym;
3686 case ABSENT_MTH:
3687 return bestSoFar;
3688 default:
3689 return sym;
3690 }
3691 }
3692 };
3693
3694 final boolean isBoxingRequired;
3695 final boolean isVarargsRequired;
3696
3697 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
3698 this.isBoxingRequired = isBoxingRequired;
3699 this.isVarargsRequired = isVarargsRequired;
3700 }
3701
3702 public boolean isBoxingRequired() {
3703 return isBoxingRequired;
3704 }
3705
3706 public boolean isVarargsRequired() {
3707 return isVarargsRequired;
3708 }
3709
3710 public boolean isApplicable(boolean boxingEnabled, boolean varargsEnabled) {
3711 return (varargsEnabled || !isVarargsRequired) &&
3712 (boxingEnabled || !isBoxingRequired);
3713 }
3714
3715 public Symbol mergeResults(Symbol prev, Symbol sym) {
3716 return sym;
3717 }
3718 }
3719
3720 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
3721
3722 /**
3723 * A resolution context is used to keep track of intermediate results of
3724 * overload resolution, such as list of method that are not applicable
3725 * (used to generate more precise diagnostics) and so on. Resolution contexts
3726 * can be nested - this means that when each overload resolution routine should
3727 * work within the resolution context it created.
3728 */
3729 class MethodResolutionContext {
3730
3731 private List<Candidate> candidates = List.nil();
3732
3733 MethodResolutionPhase step = null;
3734
3735 MethodCheck methodCheck = resolveMethodCheck;
3736
3737 private boolean internalResolution = false;
3738 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE;
3739
3740 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) {
3741 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null);
3742 candidates = candidates.append(c);
3743 }
3744
3745 void addApplicableCandidate(Symbol sym, Type mtype) {
3746 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype);
3747 candidates = candidates.append(c);
3748 }
3749
3750 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext, ResultInfo pendingResult, Warner warn) {
3751 return deferredAttr.new DeferredAttrContext(attrMode, sym, step, inferenceContext, pendingResult != null ? pendingResult.checkContext.deferredAttrContext() : deferredAttr.emptyDeferredAttrContext, warn);
3752 }
3753
3754 /**
3755 * This class represents an overload resolution candidate. There are two
3756 * kinds of candidates: applicable methods and inapplicable methods;
3757 * applicable methods have a pointer to the instantiated method type,
3758 * while inapplicable candidates contain further details about the
3759 * reason why the method has been considered inapplicable.
3760 */
3761 @SuppressWarnings("overrides")
3762 class Candidate {
3763
3764 final MethodResolutionPhase step;
3765 final Symbol sym;
3766 final JCDiagnostic details;
3767 final Type mtype;
3768
3769 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) {
3770 this.step = step;
3771 this.sym = sym;
3772 this.details = details;
3773 this.mtype = mtype;
3774 }
3775
3776 @Override
3777 public boolean equals(Object o) {
3778 if (o instanceof Candidate) {
3779 Symbol s1 = this.sym;
3780 Symbol s2 = ((Candidate)o).sym;
3781 if ((s1 != s2 &&
3782 (s1.overrides(s2, s1.owner.type.tsym, types, false) ||
3783 (s2.overrides(s1, s2.owner.type.tsym, types, false)))) ||
3784 ((s1.isConstructor() || s2.isConstructor()) && s1.owner != s2.owner))
3785 return true;
3786 }
3787 return false;
3788 }
3789
3790 boolean isApplicable() {
3791 return mtype != null;
3792 }
3793 }
3794
3795 DeferredAttr.AttrMode attrMode() {
3796 return attrMode;
3797 }
3798
3799 boolean internal() {
3800 return internalResolution;
3801 }
3802 }
3803
3804 MethodResolutionContext currentResolutionContext = null;
3805 }