Fri, 17 Apr 2015 08:55:59 -0600
8075520: Varargs access check mishandles capture variables
8077786: Check varargs access against inferred signature
Reviewed-by: vromero
1 /*
2 * Copyright (c) 1999, 2014, 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 */
26 package com.sun.tools.javac.comp;
28 import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
29 import com.sun.tools.javac.api.Formattable.LocalizedString;
30 import com.sun.tools.javac.code.*;
31 import com.sun.tools.javac.code.Symbol.*;
32 import com.sun.tools.javac.code.Type.*;
33 import com.sun.tools.javac.comp.Attr.ResultInfo;
34 import com.sun.tools.javac.comp.Check.CheckContext;
35 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
36 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
37 import com.sun.tools.javac.comp.DeferredAttr.DeferredType;
38 import com.sun.tools.javac.comp.Infer.InferenceContext;
39 import com.sun.tools.javac.comp.Infer.FreeTypeListener;
40 import com.sun.tools.javac.comp.Resolve.MethodResolutionContext.Candidate;
41 import com.sun.tools.javac.comp.Resolve.MethodResolutionDiagHelper.DiagnosticRewriter;
42 import com.sun.tools.javac.comp.Resolve.MethodResolutionDiagHelper.Template;
43 import com.sun.tools.javac.jvm.*;
44 import com.sun.tools.javac.main.Option;
45 import com.sun.tools.javac.tree.*;
46 import com.sun.tools.javac.tree.JCTree.*;
47 import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind;
48 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
49 import com.sun.tools.javac.util.*;
50 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
51 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
52 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
54 import java.util.Arrays;
55 import java.util.Collection;
56 import java.util.EnumMap;
57 import java.util.EnumSet;
58 import java.util.Iterator;
59 import java.util.LinkedHashMap;
60 import java.util.LinkedHashSet;
61 import java.util.Map;
63 import javax.lang.model.element.ElementVisitor;
65 import static com.sun.tools.javac.code.Flags.*;
66 import static com.sun.tools.javac.code.Flags.BLOCK;
67 import static com.sun.tools.javac.code.Kinds.*;
68 import static com.sun.tools.javac.code.Kinds.ERRONEOUS;
69 import static com.sun.tools.javac.code.TypeTag.*;
70 import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*;
71 import static com.sun.tools.javac.tree.JCTree.Tag.*;
73 /** Helper class for name resolution, used mostly by the attribution phase.
74 *
75 * <p><b>This is NOT part of any supported API.
76 * If you write code that depends on this, you do so at your own risk.
77 * This code and its internal interfaces are subject to change or
78 * deletion without notice.</b>
79 */
80 public class Resolve {
81 protected static final Context.Key<Resolve> resolveKey =
82 new Context.Key<Resolve>();
84 Names names;
85 Log log;
86 Symtab syms;
87 Attr attr;
88 DeferredAttr deferredAttr;
89 Check chk;
90 Infer infer;
91 ClassReader reader;
92 TreeInfo treeinfo;
93 Types types;
94 JCDiagnostic.Factory diags;
95 public final boolean boxingEnabled;
96 public final boolean varargsEnabled;
97 public final boolean allowMethodHandles;
98 public final boolean allowFunctionalInterfaceMostSpecific;
99 public final boolean checkVarargsAccessAfterResolution;
100 private final boolean debugResolve;
101 private final boolean compactMethodDiags;
102 final EnumSet<VerboseResolutionMode> verboseResolutionMode;
104 Scope polymorphicSignatureScope;
106 protected Resolve(Context context) {
107 context.put(resolveKey, this);
108 syms = Symtab.instance(context);
110 varNotFound = new
111 SymbolNotFoundError(ABSENT_VAR);
112 methodNotFound = new
113 SymbolNotFoundError(ABSENT_MTH);
114 methodWithCorrectStaticnessNotFound = new
115 SymbolNotFoundError(WRONG_STATICNESS,
116 "method found has incorrect staticness");
117 typeNotFound = new
118 SymbolNotFoundError(ABSENT_TYP);
120 names = Names.instance(context);
121 log = Log.instance(context);
122 attr = Attr.instance(context);
123 deferredAttr = DeferredAttr.instance(context);
124 chk = Check.instance(context);
125 infer = Infer.instance(context);
126 reader = ClassReader.instance(context);
127 treeinfo = TreeInfo.instance(context);
128 types = Types.instance(context);
129 diags = JCDiagnostic.Factory.instance(context);
130 Source source = Source.instance(context);
131 boxingEnabled = source.allowBoxing();
132 varargsEnabled = source.allowVarargs();
133 Options options = Options.instance(context);
134 debugResolve = options.isSet("debugresolve");
135 compactMethodDiags = options.isSet(Option.XDIAGS, "compact") ||
136 options.isUnset(Option.XDIAGS) && options.isUnset("rawDiagnostics");
137 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
138 Target target = Target.instance(context);
139 allowMethodHandles = target.hasMethodHandles();
140 allowFunctionalInterfaceMostSpecific = source.allowFunctionalInterfaceMostSpecific();
141 checkVarargsAccessAfterResolution =
142 source.allowPostApplicabilityVarargsAccessCheck();
143 polymorphicSignatureScope = new Scope(syms.noSymbol);
145 inapplicableMethodException = new InapplicableMethodException(diags);
146 }
148 /** error symbols, which are returned when resolution fails
149 */
150 private final SymbolNotFoundError varNotFound;
151 private final SymbolNotFoundError methodNotFound;
152 private final SymbolNotFoundError methodWithCorrectStaticnessNotFound;
153 private final SymbolNotFoundError typeNotFound;
155 public static Resolve instance(Context context) {
156 Resolve instance = context.get(resolveKey);
157 if (instance == null)
158 instance = new Resolve(context);
159 return instance;
160 }
162 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support">
163 enum VerboseResolutionMode {
164 SUCCESS("success"),
165 FAILURE("failure"),
166 APPLICABLE("applicable"),
167 INAPPLICABLE("inapplicable"),
168 DEFERRED_INST("deferred-inference"),
169 PREDEF("predef"),
170 OBJECT_INIT("object-init"),
171 INTERNAL("internal");
173 final String opt;
175 private VerboseResolutionMode(String opt) {
176 this.opt = opt;
177 }
179 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) {
180 String s = opts.get("verboseResolution");
181 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class);
182 if (s == null) return res;
183 if (s.contains("all")) {
184 res = EnumSet.allOf(VerboseResolutionMode.class);
185 }
186 Collection<String> args = Arrays.asList(s.split(","));
187 for (VerboseResolutionMode mode : values()) {
188 if (args.contains(mode.opt)) {
189 res.add(mode);
190 } else if (args.contains("-" + mode.opt)) {
191 res.remove(mode);
192 }
193 }
194 return res;
195 }
196 }
198 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site,
199 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) {
200 boolean success = bestSoFar.kind < ERRONEOUS;
202 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) {
203 return;
204 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) {
205 return;
206 }
208 if (bestSoFar.name == names.init &&
209 bestSoFar.owner == syms.objectType.tsym &&
210 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) {
211 return; //skip diags for Object constructor resolution
212 } else if (site == syms.predefClass.type &&
213 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) {
214 return; //skip spurious diags for predef symbols (i.e. operators)
215 } else if (currentResolutionContext.internalResolution &&
216 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) {
217 return;
218 }
220 int pos = 0;
221 int mostSpecificPos = -1;
222 ListBuffer<JCDiagnostic> subDiags = new ListBuffer<>();
223 for (Candidate c : currentResolutionContext.candidates) {
224 if (currentResolutionContext.step != c.step ||
225 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) ||
226 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) {
227 continue;
228 } else {
229 subDiags.append(c.isApplicable() ?
230 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) :
231 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details));
232 if (c.sym == bestSoFar)
233 mostSpecificPos = pos;
234 pos++;
235 }
236 }
237 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1";
238 List<Type> argtypes2 = Type.map(argtypes,
239 deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step));
240 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name,
241 site.tsym, mostSpecificPos, currentResolutionContext.step,
242 methodArguments(argtypes2),
243 methodArguments(typeargtypes));
244 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
245 log.report(d);
246 }
248 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) {
249 JCDiagnostic subDiag = null;
250 if (sym.type.hasTag(FORALL)) {
251 subDiag = diags.fragment("partial.inst.sig", inst);
252 }
254 String key = subDiag == null ?
255 "applicable.method.found" :
256 "applicable.method.found.1";
258 return diags.fragment(key, pos, sym, subDiag);
259 }
261 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) {
262 return diags.fragment("not.applicable.method.found", pos, sym, subDiag);
263 }
264 // </editor-fold>
266 /* ************************************************************************
267 * Identifier resolution
268 *************************************************************************/
270 /** An environment is "static" if its static level is greater than
271 * the one of its outer environment
272 */
273 protected static boolean isStatic(Env<AttrContext> env) {
274 return env.info.staticLevel > env.outer.info.staticLevel;
275 }
277 /** An environment is an "initializer" if it is a constructor or
278 * an instance initializer.
279 */
280 static boolean isInitializer(Env<AttrContext> env) {
281 Symbol owner = env.info.scope.owner;
282 return owner.isConstructor() ||
283 owner.owner.kind == TYP &&
284 (owner.kind == VAR ||
285 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
286 (owner.flags() & STATIC) == 0;
287 }
289 /** Is class accessible in given evironment?
290 * @param env The current environment.
291 * @param c The class whose accessibility is checked.
292 */
293 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
294 return isAccessible(env, c, false);
295 }
297 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) {
298 boolean isAccessible = false;
299 switch ((short)(c.flags() & AccessFlags)) {
300 case PRIVATE:
301 isAccessible =
302 env.enclClass.sym.outermostClass() ==
303 c.owner.outermostClass();
304 break;
305 case 0:
306 isAccessible =
307 env.toplevel.packge == c.owner // fast special case
308 ||
309 env.toplevel.packge == c.packge()
310 ||
311 // Hack: this case is added since synthesized default constructors
312 // of anonymous classes should be allowed to access
313 // classes which would be inaccessible otherwise.
314 env.enclMethod != null &&
315 (env.enclMethod.mods.flags & ANONCONSTR) != 0;
316 break;
317 default: // error recovery
318 case PUBLIC:
319 isAccessible = true;
320 break;
321 case PROTECTED:
322 isAccessible =
323 env.toplevel.packge == c.owner // fast special case
324 ||
325 env.toplevel.packge == c.packge()
326 ||
327 isInnerSubClass(env.enclClass.sym, c.owner);
328 break;
329 }
330 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
331 isAccessible :
332 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
333 }
334 //where
335 /** Is given class a subclass of given base class, or an inner class
336 * of a subclass?
337 * Return null if no such class exists.
338 * @param c The class which is the subclass or is contained in it.
339 * @param base The base class
340 */
341 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
342 while (c != null && !c.isSubClass(base, types)) {
343 c = c.owner.enclClass();
344 }
345 return c != null;
346 }
348 boolean isAccessible(Env<AttrContext> env, Type t) {
349 return isAccessible(env, t, false);
350 }
352 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) {
353 return (t.hasTag(ARRAY))
354 ? isAccessible(env, types.cvarUpperBound(types.elemtype(t)))
355 : isAccessible(env, t.tsym, checkInner);
356 }
358 /** Is symbol accessible as a member of given type in given environment?
359 * @param env The current environment.
360 * @param site The type of which the tested symbol is regarded
361 * as a member.
362 * @param sym The symbol.
363 */
364 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
365 return isAccessible(env, site, sym, false);
366 }
367 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) {
368 if (sym.name == names.init && sym.owner != site.tsym) return false;
369 switch ((short)(sym.flags() & AccessFlags)) {
370 case PRIVATE:
371 return
372 (env.enclClass.sym == sym.owner // fast special case
373 ||
374 env.enclClass.sym.outermostClass() ==
375 sym.owner.outermostClass())
376 &&
377 sym.isInheritedIn(site.tsym, types);
378 case 0:
379 return
380 (env.toplevel.packge == sym.owner.owner // fast special case
381 ||
382 env.toplevel.packge == sym.packge())
383 &&
384 isAccessible(env, site, checkInner)
385 &&
386 sym.isInheritedIn(site.tsym, types)
387 &&
388 notOverriddenIn(site, sym);
389 case PROTECTED:
390 return
391 (env.toplevel.packge == sym.owner.owner // fast special case
392 ||
393 env.toplevel.packge == sym.packge()
394 ||
395 isProtectedAccessible(sym, env.enclClass.sym, site)
396 ||
397 // OK to select instance method or field from 'super' or type name
398 // (but type names should be disallowed elsewhere!)
399 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
400 &&
401 isAccessible(env, site, checkInner)
402 &&
403 notOverriddenIn(site, sym);
404 default: // this case includes erroneous combinations as well
405 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
406 }
407 }
408 //where
409 /* `sym' is accessible only if not overridden by
410 * another symbol which is a member of `site'
411 * (because, if it is overridden, `sym' is not strictly
412 * speaking a member of `site'). A polymorphic signature method
413 * cannot be overridden (e.g. MH.invokeExact(Object[])).
414 */
415 private boolean notOverriddenIn(Type site, Symbol sym) {
416 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
417 return true;
418 else {
419 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
420 return (s2 == null || s2 == sym || sym.owner == s2.owner ||
421 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
422 }
423 }
424 //where
425 /** Is given protected symbol accessible if it is selected from given site
426 * and the selection takes place in given class?
427 * @param sym The symbol with protected access
428 * @param c The class where the access takes place
429 * @site The type of the qualifier
430 */
431 private
432 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
433 Type newSite = site.hasTag(TYPEVAR) ? site.getUpperBound() : site;
434 while (c != null &&
435 !(c.isSubClass(sym.owner, types) &&
436 (c.flags() & INTERFACE) == 0 &&
437 // In JLS 2e 6.6.2.1, the subclass restriction applies
438 // only to instance fields and methods -- types are excluded
439 // regardless of whether they are declared 'static' or not.
440 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || newSite.tsym.isSubClass(c, types))))
441 c = c.owner.enclClass();
442 return c != null;
443 }
445 /**
446 * Performs a recursive scan of a type looking for accessibility problems
447 * from current attribution environment
448 */
449 void checkAccessibleType(Env<AttrContext> env, Type t) {
450 accessibilityChecker.visit(t, env);
451 }
453 /**
454 * Accessibility type-visitor
455 */
456 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker =
457 new Types.SimpleVisitor<Void, Env<AttrContext>>() {
459 void visit(List<Type> ts, Env<AttrContext> env) {
460 for (Type t : ts) {
461 visit(t, env);
462 }
463 }
465 public Void visitType(Type t, Env<AttrContext> env) {
466 return null;
467 }
469 @Override
470 public Void visitArrayType(ArrayType t, Env<AttrContext> env) {
471 visit(t.elemtype, env);
472 return null;
473 }
475 @Override
476 public Void visitClassType(ClassType t, Env<AttrContext> env) {
477 visit(t.getTypeArguments(), env);
478 if (!isAccessible(env, t, true)) {
479 accessBase(new AccessError(t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true);
480 }
481 return null;
482 }
484 @Override
485 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) {
486 visit(t.type, env);
487 return null;
488 }
490 @Override
491 public Void visitMethodType(MethodType t, Env<AttrContext> env) {
492 visit(t.getParameterTypes(), env);
493 visit(t.getReturnType(), env);
494 visit(t.getThrownTypes(), env);
495 return null;
496 }
497 };
499 /** Try to instantiate the type of a method so that it fits
500 * given type arguments and argument types. If successful, return
501 * the method's instantiated type, else return null.
502 * The instantiation will take into account an additional leading
503 * formal parameter if the method is an instance method seen as a member
504 * of an under determined site. In this case, we treat site as an additional
505 * parameter and the parameters of the class containing the method as
506 * additional type variables that get instantiated.
507 *
508 * @param env The current environment
509 * @param site The type of which the method is a member.
510 * @param m The method symbol.
511 * @param argtypes The invocation's given value arguments.
512 * @param typeargtypes The invocation's given type arguments.
513 * @param allowBoxing Allow boxing conversions of arguments.
514 * @param useVarargs Box trailing arguments into an array for varargs.
515 */
516 Type rawInstantiate(Env<AttrContext> env,
517 Type site,
518 Symbol m,
519 ResultInfo resultInfo,
520 List<Type> argtypes,
521 List<Type> typeargtypes,
522 boolean allowBoxing,
523 boolean useVarargs,
524 Warner warn) throws Infer.InferenceException {
526 Type mt = types.memberType(site, m);
527 // tvars is the list of formal type variables for which type arguments
528 // need to inferred.
529 List<Type> tvars = List.nil();
530 if (typeargtypes == null) typeargtypes = List.nil();
531 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
532 // This is not a polymorphic method, but typeargs are supplied
533 // which is fine, see JLS 15.12.2.1
534 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
535 ForAll pmt = (ForAll) mt;
536 if (typeargtypes.length() != pmt.tvars.length())
537 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args
538 // Check type arguments are within bounds
539 List<Type> formals = pmt.tvars;
540 List<Type> actuals = typeargtypes;
541 while (formals.nonEmpty() && actuals.nonEmpty()) {
542 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
543 pmt.tvars, typeargtypes);
544 for (; bounds.nonEmpty(); bounds = bounds.tail)
545 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn))
546 throw inapplicableMethodException.setMessage("explicit.param.do.not.conform.to.bounds",actuals.head, bounds);
547 formals = formals.tail;
548 actuals = actuals.tail;
549 }
550 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
551 } else if (mt.hasTag(FORALL)) {
552 ForAll pmt = (ForAll) mt;
553 List<Type> tvars1 = types.newInstances(pmt.tvars);
554 tvars = tvars.appendList(tvars1);
555 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
556 }
558 // find out whether we need to go the slow route via infer
559 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/
560 for (List<Type> l = argtypes;
561 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
562 l = l.tail) {
563 if (l.head.hasTag(FORALL)) instNeeded = true;
564 }
566 if (instNeeded)
567 return infer.instantiateMethod(env,
568 tvars,
569 (MethodType)mt,
570 resultInfo,
571 (MethodSymbol)m,
572 argtypes,
573 allowBoxing,
574 useVarargs,
575 currentResolutionContext,
576 warn);
578 DeferredAttr.DeferredAttrContext dc = currentResolutionContext.deferredAttrContext(m, infer.emptyContext, resultInfo, warn);
579 currentResolutionContext.methodCheck.argumentsAcceptable(env, dc,
580 argtypes, mt.getParameterTypes(), warn);
581 dc.complete();
582 return mt;
583 }
585 Type checkMethod(Env<AttrContext> env,
586 Type site,
587 Symbol m,
588 ResultInfo resultInfo,
589 List<Type> argtypes,
590 List<Type> typeargtypes,
591 Warner warn) {
592 MethodResolutionContext prevContext = currentResolutionContext;
593 try {
594 currentResolutionContext = new MethodResolutionContext();
595 currentResolutionContext.attrMode = DeferredAttr.AttrMode.CHECK;
596 if (env.tree.hasTag(JCTree.Tag.REFERENCE)) {
597 //method/constructor references need special check class
598 //to handle inference variables in 'argtypes' (might happen
599 //during an unsticking round)
600 currentResolutionContext.methodCheck =
601 new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
602 }
603 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase;
604 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
605 step.isBoxingRequired(), step.isVarargsRequired(), warn);
606 }
607 finally {
608 currentResolutionContext = prevContext;
609 }
610 }
612 /** Same but returns null instead throwing a NoInstanceException
613 */
614 Type instantiate(Env<AttrContext> env,
615 Type site,
616 Symbol m,
617 ResultInfo resultInfo,
618 List<Type> argtypes,
619 List<Type> typeargtypes,
620 boolean allowBoxing,
621 boolean useVarargs,
622 Warner warn) {
623 try {
624 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
625 allowBoxing, useVarargs, warn);
626 } catch (InapplicableMethodException ex) {
627 return null;
628 }
629 }
631 /**
632 * This interface defines an entry point that should be used to perform a
633 * method check. A method check usually consist in determining as to whether
634 * a set of types (actuals) is compatible with another set of types (formals).
635 * Since the notion of compatibility can vary depending on the circumstances,
636 * this interfaces allows to easily add new pluggable method check routines.
637 */
638 interface MethodCheck {
639 /**
640 * Main method check routine. A method check usually consist in determining
641 * as to whether a set of types (actuals) is compatible with another set of
642 * types (formals). If an incompatibility is found, an unchecked exception
643 * is assumed to be thrown.
644 */
645 void argumentsAcceptable(Env<AttrContext> env,
646 DeferredAttrContext deferredAttrContext,
647 List<Type> argtypes,
648 List<Type> formals,
649 Warner warn);
651 /**
652 * Retrieve the method check object that will be used during a
653 * most specific check.
654 */
655 MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict);
656 }
658 /**
659 * Helper enum defining all method check diagnostics (used by resolveMethodCheck).
660 */
661 enum MethodCheckDiag {
662 /**
663 * Actuals and formals differs in length.
664 */
665 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"),
666 /**
667 * An actual is incompatible with a formal.
668 */
669 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"),
670 /**
671 * An actual is incompatible with the varargs element type.
672 */
673 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"),
674 /**
675 * The varargs element type is inaccessible.
676 */
677 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type");
679 final String basicKey;
680 final String inferKey;
682 MethodCheckDiag(String basicKey, String inferKey) {
683 this.basicKey = basicKey;
684 this.inferKey = inferKey;
685 }
687 String regex() {
688 return String.format("([a-z]*\\.)*(%s|%s)", basicKey, inferKey);
689 }
690 }
692 /**
693 * Dummy method check object. All methods are deemed applicable, regardless
694 * of their formal parameter types.
695 */
696 MethodCheck nilMethodCheck = new MethodCheck() {
697 public void argumentsAcceptable(Env<AttrContext> env, DeferredAttrContext deferredAttrContext, List<Type> argtypes, List<Type> formals, Warner warn) {
698 //do nothing - method always applicable regardless of actuals
699 }
701 public MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict) {
702 return this;
703 }
704 };
706 /**
707 * Base class for 'real' method checks. The class defines the logic for
708 * iterating through formals and actuals and provides and entry point
709 * that can be used by subclasses in order to define the actual check logic.
710 */
711 abstract class AbstractMethodCheck implements MethodCheck {
712 @Override
713 public void argumentsAcceptable(final Env<AttrContext> env,
714 DeferredAttrContext deferredAttrContext,
715 List<Type> argtypes,
716 List<Type> formals,
717 Warner warn) {
718 //should we expand formals?
719 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired();
720 List<JCExpression> trees = TreeInfo.args(env.tree);
722 //inference context used during this method check
723 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
725 Type varargsFormal = useVarargs ? formals.last() : null;
727 if (varargsFormal == null &&
728 argtypes.size() != formals.size()) {
729 reportMC(env.tree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
730 }
732 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
733 DiagnosticPosition pos = trees != null ? trees.head : null;
734 checkArg(pos, false, argtypes.head, formals.head, deferredAttrContext, warn);
735 argtypes = argtypes.tail;
736 formals = formals.tail;
737 trees = trees != null ? trees.tail : trees;
738 }
740 if (formals.head != varargsFormal) {
741 reportMC(env.tree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
742 }
744 if (useVarargs) {
745 //note: if applicability check is triggered by most specific test,
746 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
747 final Type elt = types.elemtype(varargsFormal);
748 while (argtypes.nonEmpty()) {
749 DiagnosticPosition pos = trees != null ? trees.head : null;
750 checkArg(pos, true, argtypes.head, elt, deferredAttrContext, warn);
751 argtypes = argtypes.tail;
752 trees = trees != null ? trees.tail : trees;
753 }
754 }
755 }
757 /**
758 * Does the actual argument conforms to the corresponding formal?
759 */
760 abstract void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn);
762 protected void reportMC(DiagnosticPosition pos, MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
763 boolean inferDiag = inferenceContext != infer.emptyContext;
764 InapplicableMethodException ex = inferDiag ?
765 infer.inferenceException : inapplicableMethodException;
766 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) {
767 Object[] args2 = new Object[args.length + 1];
768 System.arraycopy(args, 0, args2, 1, args.length);
769 args2[0] = inferenceContext.inferenceVars();
770 args = args2;
771 }
772 String key = inferDiag ? diag.inferKey : diag.basicKey;
773 throw ex.setMessage(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args));
774 }
776 public MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict) {
777 return nilMethodCheck;
778 }
780 }
782 /**
783 * Arity-based method check. A method is applicable if the number of actuals
784 * supplied conforms to the method signature.
785 */
786 MethodCheck arityMethodCheck = new AbstractMethodCheck() {
787 @Override
788 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
789 //do nothing - actual always compatible to formals
790 }
792 @Override
793 public String toString() {
794 return "arityMethodCheck";
795 }
796 };
798 List<Type> dummyArgs(int length) {
799 ListBuffer<Type> buf = new ListBuffer<>();
800 for (int i = 0 ; i < length ; i++) {
801 buf.append(Type.noType);
802 }
803 return buf.toList();
804 }
806 /**
807 * Main method applicability routine. Given a list of actual types A,
808 * a list of formal types F, determines whether the types in A are
809 * compatible (by method invocation conversion) with the types in F.
810 *
811 * Since this routine is shared between overload resolution and method
812 * type-inference, a (possibly empty) inference context is used to convert
813 * formal types to the corresponding 'undet' form ahead of a compatibility
814 * check so that constraints can be propagated and collected.
815 *
816 * Moreover, if one or more types in A is a deferred type, this routine uses
817 * DeferredAttr in order to perform deferred attribution. If one or more actual
818 * deferred types are stuck, they are placed in a queue and revisited later
819 * after the remainder of the arguments have been seen. If this is not sufficient
820 * to 'unstuck' the argument, a cyclic inference error is called out.
821 *
822 * A method check handler (see above) is used in order to report errors.
823 */
824 MethodCheck resolveMethodCheck = new AbstractMethodCheck() {
826 @Override
827 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
828 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
829 mresult.check(pos, actual);
830 }
832 @Override
833 public void argumentsAcceptable(final Env<AttrContext> env,
834 DeferredAttrContext deferredAttrContext,
835 List<Type> argtypes,
836 List<Type> formals,
837 Warner warn) {
838 super.argumentsAcceptable(env, deferredAttrContext, argtypes, formals, warn);
839 // should we check varargs element type accessibility?
840 if (deferredAttrContext.phase.isVarargsRequired()) {
841 if (deferredAttrContext.mode == AttrMode.CHECK || !checkVarargsAccessAfterResolution) {
842 varargsAccessible(env, types.elemtype(formals.last()), deferredAttrContext.inferenceContext);
843 }
844 }
845 }
847 /**
848 * Test that the runtime array element type corresponding to 't' is accessible. 't' should be the
849 * varargs element type of either the method invocation type signature (after inference completes)
850 * or the method declaration signature (before inference completes).
851 */
852 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) {
853 if (inferenceContext.free(t)) {
854 inferenceContext.addFreeTypeListener(List.of(t), new FreeTypeListener() {
855 @Override
856 public void typesInferred(InferenceContext inferenceContext) {
857 varargsAccessible(env, inferenceContext.asInstType(t), inferenceContext);
858 }
859 });
860 } else {
861 if (!isAccessible(env, types.erasure(t))) {
862 Symbol location = env.enclClass.sym;
863 reportMC(env.tree, MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
864 }
865 }
866 }
868 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
869 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
870 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
871 MethodCheckDiag methodDiag = varargsCheck ?
872 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
874 @Override
875 public void report(DiagnosticPosition pos, JCDiagnostic details) {
876 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
877 }
878 };
879 return new MethodResultInfo(to, checkContext);
880 }
882 @Override
883 public MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict) {
884 return new MostSpecificCheck(strict, actuals);
885 }
887 @Override
888 public String toString() {
889 return "resolveMethodCheck";
890 }
891 };
893 /**
894 * This class handles method reference applicability checks; since during
895 * these checks it's sometime possible to have inference variables on
896 * the actual argument types list, the method applicability check must be
897 * extended so that inference variables are 'opened' as needed.
898 */
899 class MethodReferenceCheck extends AbstractMethodCheck {
901 InferenceContext pendingInferenceContext;
903 MethodReferenceCheck(InferenceContext pendingInferenceContext) {
904 this.pendingInferenceContext = pendingInferenceContext;
905 }
907 @Override
908 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
909 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
910 mresult.check(pos, actual);
911 }
913 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
914 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
915 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
916 MethodCheckDiag methodDiag = varargsCheck ?
917 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
919 @Override
920 public boolean compatible(Type found, Type req, Warner warn) {
921 found = pendingInferenceContext.asUndetVar(found);
922 if (found.hasTag(UNDETVAR) && req.isPrimitive()) {
923 req = types.boxedClass(req).type;
924 }
925 return super.compatible(found, req, warn);
926 }
928 @Override
929 public void report(DiagnosticPosition pos, JCDiagnostic details) {
930 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
931 }
932 };
933 return new MethodResultInfo(to, checkContext);
934 }
936 @Override
937 public MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict) {
938 return new MostSpecificCheck(strict, actuals);
939 }
940 };
942 /**
943 * Check context to be used during method applicability checks. A method check
944 * context might contain inference variables.
945 */
946 abstract class MethodCheckContext implements CheckContext {
948 boolean strict;
949 DeferredAttrContext deferredAttrContext;
950 Warner rsWarner;
952 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) {
953 this.strict = strict;
954 this.deferredAttrContext = deferredAttrContext;
955 this.rsWarner = rsWarner;
956 }
958 public boolean compatible(Type found, Type req, Warner warn) {
959 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
960 return strict ?
961 types.isSubtypeUnchecked(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn) :
962 types.isConvertible(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn);
963 }
965 public void report(DiagnosticPosition pos, JCDiagnostic details) {
966 throw inapplicableMethodException.setMessage(details);
967 }
969 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
970 return rsWarner;
971 }
973 public InferenceContext inferenceContext() {
974 return deferredAttrContext.inferenceContext;
975 }
977 public DeferredAttrContext deferredAttrContext() {
978 return deferredAttrContext;
979 }
981 @Override
982 public String toString() {
983 return "MethodReferenceCheck";
984 }
986 }
988 /**
989 * ResultInfo class to be used during method applicability checks. Check
990 * for deferred types goes through special path.
991 */
992 class MethodResultInfo extends ResultInfo {
994 public MethodResultInfo(Type pt, CheckContext checkContext) {
995 attr.super(VAL, pt, checkContext);
996 }
998 @Override
999 protected Type check(DiagnosticPosition pos, Type found) {
1000 if (found.hasTag(DEFERRED)) {
1001 DeferredType dt = (DeferredType)found;
1002 return dt.check(this);
1003 } else {
1004 Type uResult = U(found.baseType());
1005 Type capturedType = pos == null || pos.getTree() == null ?
1006 types.capture(uResult) :
1007 checkContext.inferenceContext()
1008 .cachedCapture(pos.getTree(), uResult, true);
1009 return super.check(pos, chk.checkNonVoid(pos, capturedType));
1010 }
1011 }
1013 /**
1014 * javac has a long-standing 'simplification' (see 6391995):
1015 * given an actual argument type, the method check is performed
1016 * on its upper bound. This leads to inconsistencies when an
1017 * argument type is checked against itself. For example, given
1018 * a type-variable T, it is not true that {@code U(T) <: T},
1019 * so we need to guard against that.
1020 */
1021 private Type U(Type found) {
1022 return found == pt ?
1023 found : types.cvarUpperBound(found);
1024 }
1026 @Override
1027 protected MethodResultInfo dup(Type newPt) {
1028 return new MethodResultInfo(newPt, checkContext);
1029 }
1031 @Override
1032 protected ResultInfo dup(CheckContext newContext) {
1033 return new MethodResultInfo(pt, newContext);
1034 }
1035 }
1037 /**
1038 * Most specific method applicability routine. Given a list of actual types A,
1039 * a list of formal types F1, and a list of formal types F2, the routine determines
1040 * as to whether the types in F1 can be considered more specific than those in F2 w.r.t.
1041 * argument types A.
1042 */
1043 class MostSpecificCheck implements MethodCheck {
1045 boolean strict;
1046 List<Type> actuals;
1048 MostSpecificCheck(boolean strict, List<Type> actuals) {
1049 this.strict = strict;
1050 this.actuals = actuals;
1051 }
1053 @Override
1054 public void argumentsAcceptable(final Env<AttrContext> env,
1055 DeferredAttrContext deferredAttrContext,
1056 List<Type> formals1,
1057 List<Type> formals2,
1058 Warner warn) {
1059 formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired());
1060 while (formals2.nonEmpty()) {
1061 ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head);
1062 mresult.check(null, formals1.head);
1063 formals1 = formals1.tail;
1064 formals2 = formals2.tail;
1065 actuals = actuals.isEmpty() ? actuals : actuals.tail;
1066 }
1067 }
1069 /**
1070 * Create a method check context to be used during the most specific applicability check
1071 */
1072 ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext,
1073 Warner rsWarner, Type actual) {
1074 return attr.new ResultInfo(Kinds.VAL, to,
1075 new MostSpecificCheckContext(strict, deferredAttrContext, rsWarner, actual));
1076 }
1078 /**
1079 * Subclass of method check context class that implements most specific
1080 * method conversion. If the actual type under analysis is a deferred type
1081 * a full blown structural analysis is carried out.
1082 */
1083 class MostSpecificCheckContext extends MethodCheckContext {
1085 Type actual;
1087 public MostSpecificCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) {
1088 super(strict, deferredAttrContext, rsWarner);
1089 this.actual = actual;
1090 }
1092 public boolean compatible(Type found, Type req, Warner warn) {
1093 if (allowFunctionalInterfaceMostSpecific &&
1094 unrelatedFunctionalInterfaces(found, req) &&
1095 (actual != null && actual.getTag() == DEFERRED)) {
1096 DeferredType dt = (DeferredType) actual;
1097 DeferredType.SpeculativeCache.Entry e =
1098 dt.speculativeCache.get(deferredAttrContext.msym, deferredAttrContext.phase);
1099 if (e != null && e.speculativeTree != deferredAttr.stuckTree) {
1100 return functionalInterfaceMostSpecific(found, req, e.speculativeTree, warn);
1101 }
1102 }
1103 return super.compatible(found, req, warn);
1104 }
1106 /** Whether {@code t} and {@code s} are unrelated functional interface types. */
1107 private boolean unrelatedFunctionalInterfaces(Type t, Type s) {
1108 return types.isFunctionalInterface(t.tsym) &&
1109 types.isFunctionalInterface(s.tsym) &&
1110 types.asSuper(t, s.tsym) == null &&
1111 types.asSuper(s, t.tsym) == null;
1112 }
1114 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */
1115 private boolean functionalInterfaceMostSpecific(Type t, Type s, JCTree tree, Warner warn) {
1116 FunctionalInterfaceMostSpecificChecker msc = new FunctionalInterfaceMostSpecificChecker(t, s, warn);
1117 msc.scan(tree);
1118 return msc.result;
1119 }
1121 /**
1122 * Tests whether one functional interface type can be considered more specific
1123 * than another unrelated functional interface type for the scanned expression.
1124 */
1125 class FunctionalInterfaceMostSpecificChecker extends DeferredAttr.PolyScanner {
1127 final Type t;
1128 final Type s;
1129 final Warner warn;
1130 boolean result;
1132 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */
1133 FunctionalInterfaceMostSpecificChecker(Type t, Type s, Warner warn) {
1134 this.t = t;
1135 this.s = s;
1136 this.warn = warn;
1137 result = true;
1138 }
1140 @Override
1141 void skip(JCTree tree) {
1142 result &= false;
1143 }
1145 @Override
1146 public void visitConditional(JCConditional tree) {
1147 scan(tree.truepart);
1148 scan(tree.falsepart);
1149 }
1151 @Override
1152 public void visitReference(JCMemberReference tree) {
1153 Type desc_t = types.findDescriptorType(t);
1154 Type desc_s = types.findDescriptorType(s);
1155 // use inference variables here for more-specific inference (18.5.4)
1156 if (!types.isSameTypes(desc_t.getParameterTypes(),
1157 inferenceContext().asUndetVars(desc_s.getParameterTypes()))) {
1158 result &= false;
1159 } else {
1160 // compare return types
1161 Type ret_t = desc_t.getReturnType();
1162 Type ret_s = desc_s.getReturnType();
1163 if (ret_s.hasTag(VOID)) {
1164 result &= true;
1165 } else if (ret_t.hasTag(VOID)) {
1166 result &= false;
1167 } else if (ret_t.isPrimitive() != ret_s.isPrimitive()) {
1168 boolean retValIsPrimitive =
1169 tree.refPolyKind == PolyKind.STANDALONE &&
1170 tree.sym.type.getReturnType().isPrimitive();
1171 result &= (retValIsPrimitive == ret_t.isPrimitive()) &&
1172 (retValIsPrimitive != ret_s.isPrimitive());
1173 } else {
1174 result &= MostSpecificCheckContext.super.compatible(ret_t, ret_s, warn);
1175 }
1176 }
1177 }
1179 @Override
1180 public void visitLambda(JCLambda tree) {
1181 Type desc_t = types.findDescriptorType(t);
1182 Type desc_s = types.findDescriptorType(s);
1183 // use inference variables here for more-specific inference (18.5.4)
1184 if (!types.isSameTypes(desc_t.getParameterTypes(),
1185 inferenceContext().asUndetVars(desc_s.getParameterTypes()))) {
1186 result &= false;
1187 } else {
1188 // compare return types
1189 Type ret_t = desc_t.getReturnType();
1190 Type ret_s = desc_s.getReturnType();
1191 if (ret_s.hasTag(VOID)) {
1192 result &= true;
1193 } else if (ret_t.hasTag(VOID)) {
1194 result &= false;
1195 } else if (unrelatedFunctionalInterfaces(ret_t, ret_s)) {
1196 for (JCExpression expr : lambdaResults(tree)) {
1197 result &= functionalInterfaceMostSpecific(ret_t, ret_s, expr, warn);
1198 }
1199 } else if (ret_t.isPrimitive() != ret_s.isPrimitive()) {
1200 for (JCExpression expr : lambdaResults(tree)) {
1201 boolean retValIsPrimitive = expr.isStandalone() && expr.type.isPrimitive();
1202 result &= (retValIsPrimitive == ret_t.isPrimitive()) &&
1203 (retValIsPrimitive != ret_s.isPrimitive());
1204 }
1205 } else {
1206 result &= MostSpecificCheckContext.super.compatible(ret_t, ret_s, warn);
1207 }
1208 }
1209 }
1210 //where
1212 private List<JCExpression> lambdaResults(JCLambda lambda) {
1213 if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) {
1214 return List.of((JCExpression) lambda.body);
1215 } else {
1216 final ListBuffer<JCExpression> buffer = new ListBuffer<>();
1217 DeferredAttr.LambdaReturnScanner lambdaScanner =
1218 new DeferredAttr.LambdaReturnScanner() {
1219 @Override
1220 public void visitReturn(JCReturn tree) {
1221 if (tree.expr != null) {
1222 buffer.append(tree.expr);
1223 }
1224 }
1225 };
1226 lambdaScanner.scan(lambda.body);
1227 return buffer.toList();
1228 }
1229 }
1230 }
1232 }
1234 public MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict) {
1235 Assert.error("Cannot get here!");
1236 return null;
1237 }
1238 }
1240 public static class InapplicableMethodException extends RuntimeException {
1241 private static final long serialVersionUID = 0;
1243 JCDiagnostic diagnostic;
1244 JCDiagnostic.Factory diags;
1246 InapplicableMethodException(JCDiagnostic.Factory diags) {
1247 this.diagnostic = null;
1248 this.diags = diags;
1249 }
1250 InapplicableMethodException setMessage() {
1251 return setMessage((JCDiagnostic)null);
1252 }
1253 InapplicableMethodException setMessage(String key) {
1254 return setMessage(key != null ? diags.fragment(key) : null);
1255 }
1256 InapplicableMethodException setMessage(String key, Object... args) {
1257 return setMessage(key != null ? diags.fragment(key, args) : null);
1258 }
1259 InapplicableMethodException setMessage(JCDiagnostic diag) {
1260 this.diagnostic = diag;
1261 return this;
1262 }
1264 public JCDiagnostic getDiagnostic() {
1265 return diagnostic;
1266 }
1267 }
1268 private final InapplicableMethodException inapplicableMethodException;
1270 /* ***************************************************************************
1271 * Symbol lookup
1272 * the following naming conventions for arguments are used
1273 *
1274 * env is the environment where the symbol was mentioned
1275 * site is the type of which the symbol is a member
1276 * name is the symbol's name
1277 * if no arguments are given
1278 * argtypes are the value arguments, if we search for a method
1279 *
1280 * If no symbol was found, a ResolveError detailing the problem is returned.
1281 ****************************************************************************/
1283 /** Find field. Synthetic fields are always skipped.
1284 * @param env The current environment.
1285 * @param site The original type from where the selection takes place.
1286 * @param name The name of the field.
1287 * @param c The class to search for the field. This is always
1288 * a superclass or implemented interface of site's class.
1289 */
1290 Symbol findField(Env<AttrContext> env,
1291 Type site,
1292 Name name,
1293 TypeSymbol c) {
1294 while (c.type.hasTag(TYPEVAR))
1295 c = c.type.getUpperBound().tsym;
1296 Symbol bestSoFar = varNotFound;
1297 Symbol sym;
1298 Scope.Entry e = c.members().lookup(name);
1299 while (e.scope != null) {
1300 if (e.sym.kind == VAR && (e.sym.flags_field & SYNTHETIC) == 0) {
1301 return isAccessible(env, site, e.sym)
1302 ? e.sym : new AccessError(env, site, e.sym);
1303 }
1304 e = e.next();
1305 }
1306 Type st = types.supertype(c.type);
1307 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) {
1308 sym = findField(env, site, name, st.tsym);
1309 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1310 }
1311 for (List<Type> l = types.interfaces(c.type);
1312 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1313 l = l.tail) {
1314 sym = findField(env, site, name, l.head.tsym);
1315 if (bestSoFar.exists() && sym.exists() &&
1316 sym.owner != bestSoFar.owner)
1317 bestSoFar = new AmbiguityError(bestSoFar, sym);
1318 else if (sym.kind < bestSoFar.kind)
1319 bestSoFar = sym;
1320 }
1321 return bestSoFar;
1322 }
1324 /** Resolve a field identifier, throw a fatal error if not found.
1325 * @param pos The position to use for error reporting.
1326 * @param env The environment current at the method invocation.
1327 * @param site The type of the qualifying expression, in which
1328 * identifier is searched.
1329 * @param name The identifier's name.
1330 */
1331 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
1332 Type site, Name name) {
1333 Symbol sym = findField(env, site, name, site.tsym);
1334 if (sym.kind == VAR) return (VarSymbol)sym;
1335 else throw new FatalError(
1336 diags.fragment("fatal.err.cant.locate.field",
1337 name));
1338 }
1340 /** Find unqualified variable or field with given name.
1341 * Synthetic fields always skipped.
1342 * @param env The current environment.
1343 * @param name The name of the variable or field.
1344 */
1345 Symbol findVar(Env<AttrContext> env, Name name) {
1346 Symbol bestSoFar = varNotFound;
1347 Symbol sym;
1348 Env<AttrContext> env1 = env;
1349 boolean staticOnly = false;
1350 while (env1.outer != null) {
1351 if (isStatic(env1)) staticOnly = true;
1352 Scope.Entry e = env1.info.scope.lookup(name);
1353 while (e.scope != null &&
1354 (e.sym.kind != VAR ||
1355 (e.sym.flags_field & SYNTHETIC) != 0))
1356 e = e.next();
1357 sym = (e.scope != null)
1358 ? e.sym
1359 : findField(
1360 env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
1361 if (sym.exists()) {
1362 if (staticOnly &&
1363 sym.kind == VAR &&
1364 sym.owner.kind == TYP &&
1365 (sym.flags() & STATIC) == 0)
1366 return new StaticError(sym);
1367 else
1368 return sym;
1369 } else if (sym.kind < bestSoFar.kind) {
1370 bestSoFar = sym;
1371 }
1373 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1374 env1 = env1.outer;
1375 }
1377 sym = findField(env, syms.predefClass.type, name, syms.predefClass);
1378 if (sym.exists())
1379 return sym;
1380 if (bestSoFar.exists())
1381 return bestSoFar;
1383 Symbol origin = null;
1384 for (Scope sc : new Scope[] { env.toplevel.namedImportScope, env.toplevel.starImportScope }) {
1385 Scope.Entry e = sc.lookup(name);
1386 for (; e.scope != null; e = e.next()) {
1387 sym = e.sym;
1388 if (sym.kind != VAR)
1389 continue;
1390 // invariant: sym.kind == VAR
1391 if (bestSoFar.kind < AMBIGUOUS && sym.owner != bestSoFar.owner)
1392 return new AmbiguityError(bestSoFar, sym);
1393 else if (bestSoFar.kind >= VAR) {
1394 origin = e.getOrigin().owner;
1395 bestSoFar = isAccessible(env, origin.type, sym)
1396 ? sym : new AccessError(env, origin.type, sym);
1397 }
1398 }
1399 if (bestSoFar.exists()) break;
1400 }
1401 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
1402 return bestSoFar.clone(origin);
1403 else
1404 return bestSoFar;
1405 }
1407 Warner noteWarner = new Warner();
1409 /** Select the best method for a call site among two choices.
1410 * @param env The current environment.
1411 * @param site The original type from where the
1412 * selection takes place.
1413 * @param argtypes The invocation's value arguments,
1414 * @param typeargtypes The invocation's type arguments,
1415 * @param sym Proposed new best match.
1416 * @param bestSoFar Previously found best match.
1417 * @param allowBoxing Allow boxing conversions of arguments.
1418 * @param useVarargs Box trailing arguments into an array for varargs.
1419 */
1420 @SuppressWarnings("fallthrough")
1421 Symbol selectBest(Env<AttrContext> env,
1422 Type site,
1423 List<Type> argtypes,
1424 List<Type> typeargtypes,
1425 Symbol sym,
1426 Symbol bestSoFar,
1427 boolean allowBoxing,
1428 boolean useVarargs,
1429 boolean operator) {
1430 if (sym.kind == ERR ||
1431 !sym.isInheritedIn(site.tsym, types)) {
1432 return bestSoFar;
1433 } else if (useVarargs && (sym.flags() & VARARGS) == 0) {
1434 return bestSoFar.kind >= ERRONEOUS ?
1435 new BadVarargsMethod((ResolveError)bestSoFar.baseSymbol()) :
1436 bestSoFar;
1437 }
1438 Assert.check(sym.kind < AMBIGUOUS);
1439 try {
1440 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes,
1441 allowBoxing, useVarargs, types.noWarnings);
1442 if (!operator || verboseResolutionMode.contains(VerboseResolutionMode.PREDEF))
1443 currentResolutionContext.addApplicableCandidate(sym, mt);
1444 } catch (InapplicableMethodException ex) {
1445 if (!operator)
1446 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic());
1447 switch (bestSoFar.kind) {
1448 case ABSENT_MTH:
1449 return new InapplicableSymbolError(currentResolutionContext);
1450 case WRONG_MTH:
1451 if (operator) return bestSoFar;
1452 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1453 default:
1454 return bestSoFar;
1455 }
1456 }
1457 if (!isAccessible(env, site, sym)) {
1458 return (bestSoFar.kind == ABSENT_MTH)
1459 ? new AccessError(env, site, sym)
1460 : bestSoFar;
1461 }
1462 return (bestSoFar.kind > AMBIGUOUS)
1463 ? sym
1464 : mostSpecific(argtypes, sym, bestSoFar, env, site,
1465 allowBoxing && operator, useVarargs);
1466 }
1468 /* Return the most specific of the two methods for a call,
1469 * given that both are accessible and applicable.
1470 * @param m1 A new candidate for most specific.
1471 * @param m2 The previous most specific candidate.
1472 * @param env The current environment.
1473 * @param site The original type from where the selection
1474 * takes place.
1475 * @param allowBoxing Allow boxing conversions of arguments.
1476 * @param useVarargs Box trailing arguments into an array for varargs.
1477 */
1478 Symbol mostSpecific(List<Type> argtypes, Symbol m1,
1479 Symbol m2,
1480 Env<AttrContext> env,
1481 final Type site,
1482 boolean allowBoxing,
1483 boolean useVarargs) {
1484 switch (m2.kind) {
1485 case MTH:
1486 if (m1 == m2) return m1;
1487 boolean m1SignatureMoreSpecific =
1488 signatureMoreSpecific(argtypes, env, site, m1, m2, allowBoxing, useVarargs);
1489 boolean m2SignatureMoreSpecific =
1490 signatureMoreSpecific(argtypes, env, site, m2, m1, allowBoxing, useVarargs);
1491 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
1492 Type mt1 = types.memberType(site, m1);
1493 Type mt2 = types.memberType(site, m2);
1494 if (!types.overrideEquivalent(mt1, mt2))
1495 return ambiguityError(m1, m2);
1497 // same signature; select (a) the non-bridge method, or
1498 // (b) the one that overrides the other, or (c) the concrete
1499 // one, or (d) merge both abstract signatures
1500 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
1501 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
1503 // if one overrides or hides the other, use it
1504 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
1505 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
1506 if (types.asSuper(m1Owner.type, m2Owner) != null &&
1507 ((m1.owner.flags_field & INTERFACE) == 0 ||
1508 (m2.owner.flags_field & INTERFACE) != 0) &&
1509 m1.overrides(m2, m1Owner, types, false))
1510 return m1;
1511 if (types.asSuper(m2Owner.type, m1Owner) != null &&
1512 ((m2.owner.flags_field & INTERFACE) == 0 ||
1513 (m1.owner.flags_field & INTERFACE) != 0) &&
1514 m2.overrides(m1, m2Owner, types, false))
1515 return m2;
1516 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
1517 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
1518 if (m1Abstract && !m2Abstract) return m2;
1519 if (m2Abstract && !m1Abstract) return m1;
1520 // both abstract or both concrete
1521 return ambiguityError(m1, m2);
1522 }
1523 if (m1SignatureMoreSpecific) return m1;
1524 if (m2SignatureMoreSpecific) return m2;
1525 return ambiguityError(m1, m2);
1526 case AMBIGUOUS:
1527 //compare m1 to ambiguous methods in m2
1528 AmbiguityError e = (AmbiguityError)m2.baseSymbol();
1529 boolean m1MoreSpecificThanAnyAmbiguous = true;
1530 boolean allAmbiguousMoreSpecificThanM1 = true;
1531 for (Symbol s : e.ambiguousSyms) {
1532 Symbol moreSpecific = mostSpecific(argtypes, m1, s, env, site, allowBoxing, useVarargs);
1533 m1MoreSpecificThanAnyAmbiguous &= moreSpecific == m1;
1534 allAmbiguousMoreSpecificThanM1 &= moreSpecific == s;
1535 }
1536 if (m1MoreSpecificThanAnyAmbiguous)
1537 return m1;
1538 //if m1 is more specific than some ambiguous methods, but other ambiguous methods are
1539 //more specific than m1, add it as a new ambiguous method:
1540 if (!allAmbiguousMoreSpecificThanM1)
1541 e.addAmbiguousSymbol(m1);
1542 return e;
1543 default:
1544 throw new AssertionError();
1545 }
1546 }
1547 //where
1548 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean allowBoxing, boolean useVarargs) {
1549 noteWarner.clear();
1550 int maxLength = Math.max(
1551 Math.max(m1.type.getParameterTypes().length(), actuals.length()),
1552 m2.type.getParameterTypes().length());
1553 MethodResolutionContext prevResolutionContext = currentResolutionContext;
1554 try {
1555 currentResolutionContext = new MethodResolutionContext();
1556 currentResolutionContext.step = prevResolutionContext.step;
1557 currentResolutionContext.methodCheck =
1558 prevResolutionContext.methodCheck.mostSpecificCheck(actuals, !allowBoxing);
1559 Type mst = instantiate(env, site, m2, null,
1560 adjustArgs(types.cvarLowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null,
1561 allowBoxing, useVarargs, noteWarner);
1562 return mst != null &&
1563 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
1564 } finally {
1565 currentResolutionContext = prevResolutionContext;
1566 }
1567 }
1569 List<Type> adjustArgs(List<Type> args, Symbol msym, int length, boolean allowVarargs) {
1570 if ((msym.flags() & VARARGS) != 0 && allowVarargs) {
1571 Type varargsElem = types.elemtype(args.last());
1572 if (varargsElem == null) {
1573 Assert.error("Bad varargs = " + args.last() + " " + msym);
1574 }
1575 List<Type> newArgs = args.reverse().tail.prepend(varargsElem).reverse();
1576 while (newArgs.length() < length) {
1577 newArgs = newArgs.append(newArgs.last());
1578 }
1579 return newArgs;
1580 } else {
1581 return args;
1582 }
1583 }
1584 //where
1585 Type mostSpecificReturnType(Type mt1, Type mt2) {
1586 Type rt1 = mt1.getReturnType();
1587 Type rt2 = mt2.getReturnType();
1589 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL)) {
1590 //if both are generic methods, adjust return type ahead of subtyping check
1591 rt1 = types.subst(rt1, mt1.getTypeArguments(), mt2.getTypeArguments());
1592 }
1593 //first use subtyping, then return type substitutability
1594 if (types.isSubtype(rt1, rt2)) {
1595 return mt1;
1596 } else if (types.isSubtype(rt2, rt1)) {
1597 return mt2;
1598 } else if (types.returnTypeSubstitutable(mt1, mt2)) {
1599 return mt1;
1600 } else if (types.returnTypeSubstitutable(mt2, mt1)) {
1601 return mt2;
1602 } else {
1603 return null;
1604 }
1605 }
1606 //where
1607 Symbol ambiguityError(Symbol m1, Symbol m2) {
1608 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
1609 return (m1.flags() & CLASH) == 0 ? m1 : m2;
1610 } else {
1611 return new AmbiguityError(m1, m2);
1612 }
1613 }
1615 Symbol findMethodInScope(Env<AttrContext> env,
1616 Type site,
1617 Name name,
1618 List<Type> argtypes,
1619 List<Type> typeargtypes,
1620 Scope sc,
1621 Symbol bestSoFar,
1622 boolean allowBoxing,
1623 boolean useVarargs,
1624 boolean operator,
1625 boolean abstractok) {
1626 for (Symbol s : sc.getElementsByName(name, new LookupFilter(abstractok))) {
1627 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s,
1628 bestSoFar, allowBoxing, useVarargs, operator);
1629 }
1630 return bestSoFar;
1631 }
1632 //where
1633 class LookupFilter implements Filter<Symbol> {
1635 boolean abstractOk;
1637 LookupFilter(boolean abstractOk) {
1638 this.abstractOk = abstractOk;
1639 }
1641 public boolean accepts(Symbol s) {
1642 long flags = s.flags();
1643 return s.kind == MTH &&
1644 (flags & SYNTHETIC) == 0 &&
1645 (abstractOk ||
1646 (flags & DEFAULT) != 0 ||
1647 (flags & ABSTRACT) == 0);
1648 }
1649 };
1651 /** Find best qualified method matching given name, type and value
1652 * arguments.
1653 * @param env The current environment.
1654 * @param site The original type from where the selection
1655 * takes place.
1656 * @param name The method's name.
1657 * @param argtypes The method's value arguments.
1658 * @param typeargtypes The method's type arguments
1659 * @param allowBoxing Allow boxing conversions of arguments.
1660 * @param useVarargs Box trailing arguments into an array for varargs.
1661 */
1662 Symbol findMethod(Env<AttrContext> env,
1663 Type site,
1664 Name name,
1665 List<Type> argtypes,
1666 List<Type> typeargtypes,
1667 boolean allowBoxing,
1668 boolean useVarargs,
1669 boolean operator) {
1670 Symbol bestSoFar = methodNotFound;
1671 bestSoFar = findMethod(env,
1672 site,
1673 name,
1674 argtypes,
1675 typeargtypes,
1676 site.tsym.type,
1677 bestSoFar,
1678 allowBoxing,
1679 useVarargs,
1680 operator);
1681 return bestSoFar;
1682 }
1683 // where
1684 private Symbol findMethod(Env<AttrContext> env,
1685 Type site,
1686 Name name,
1687 List<Type> argtypes,
1688 List<Type> typeargtypes,
1689 Type intype,
1690 Symbol bestSoFar,
1691 boolean allowBoxing,
1692 boolean useVarargs,
1693 boolean operator) {
1694 @SuppressWarnings({"unchecked","rawtypes"})
1695 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() };
1696 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK;
1697 for (TypeSymbol s : superclasses(intype)) {
1698 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1699 s.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1700 if (name == names.init) return bestSoFar;
1701 iphase = (iphase == null) ? null : iphase.update(s, this);
1702 if (iphase != null) {
1703 for (Type itype : types.interfaces(s.type)) {
1704 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]);
1705 }
1706 }
1707 }
1709 Symbol concrete = bestSoFar.kind < ERR &&
1710 (bestSoFar.flags() & ABSTRACT) == 0 ?
1711 bestSoFar : methodNotFound;
1713 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) {
1714 //keep searching for abstract methods
1715 for (Type itype : itypes[iphase2.ordinal()]) {
1716 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure())
1717 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK &&
1718 (itype.tsym.flags() & DEFAULT) == 0) continue;
1719 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1720 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1721 if (concrete != bestSoFar &&
1722 concrete.kind < ERR && bestSoFar.kind < ERR &&
1723 types.isSubSignature(concrete.type, bestSoFar.type)) {
1724 //this is an hack - as javac does not do full membership checks
1725 //most specific ends up comparing abstract methods that might have
1726 //been implemented by some concrete method in a subclass and,
1727 //because of raw override, it is possible for an abstract method
1728 //to be more specific than the concrete method - so we need
1729 //to explicitly call that out (see CR 6178365)
1730 bestSoFar = concrete;
1731 }
1732 }
1733 }
1734 return bestSoFar;
1735 }
1737 enum InterfaceLookupPhase {
1738 ABSTRACT_OK() {
1739 @Override
1740 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1741 //We should not look for abstract methods if receiver is a concrete class
1742 //(as concrete classes are expected to implement all abstracts coming
1743 //from superinterfaces)
1744 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) {
1745 return this;
1746 } else {
1747 return DEFAULT_OK;
1748 }
1749 }
1750 },
1751 DEFAULT_OK() {
1752 @Override
1753 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1754 return this;
1755 }
1756 };
1758 abstract InterfaceLookupPhase update(Symbol s, Resolve rs);
1759 }
1761 /**
1762 * Return an Iterable object to scan the superclasses of a given type.
1763 * It's crucial that the scan is done lazily, as we don't want to accidentally
1764 * access more supertypes than strictly needed (as this could trigger completion
1765 * errors if some of the not-needed supertypes are missing/ill-formed).
1766 */
1767 Iterable<TypeSymbol> superclasses(final Type intype) {
1768 return new Iterable<TypeSymbol>() {
1769 public Iterator<TypeSymbol> iterator() {
1770 return new Iterator<TypeSymbol>() {
1772 List<TypeSymbol> seen = List.nil();
1773 TypeSymbol currentSym = symbolFor(intype);
1774 TypeSymbol prevSym = null;
1776 public boolean hasNext() {
1777 if (currentSym == syms.noSymbol) {
1778 currentSym = symbolFor(types.supertype(prevSym.type));
1779 }
1780 return currentSym != null;
1781 }
1783 public TypeSymbol next() {
1784 prevSym = currentSym;
1785 currentSym = syms.noSymbol;
1786 Assert.check(prevSym != null || prevSym != syms.noSymbol);
1787 return prevSym;
1788 }
1790 public void remove() {
1791 throw new UnsupportedOperationException();
1792 }
1794 TypeSymbol symbolFor(Type t) {
1795 if (!t.hasTag(CLASS) &&
1796 !t.hasTag(TYPEVAR)) {
1797 return null;
1798 }
1799 while (t.hasTag(TYPEVAR))
1800 t = t.getUpperBound();
1801 if (seen.contains(t.tsym)) {
1802 //degenerate case in which we have a circular
1803 //class hierarchy - because of ill-formed classfiles
1804 return null;
1805 }
1806 seen = seen.prepend(t.tsym);
1807 return t.tsym;
1808 }
1809 };
1810 }
1811 };
1812 }
1814 /** Find unqualified method matching given name, type and value arguments.
1815 * @param env The current environment.
1816 * @param name The method's name.
1817 * @param argtypes The method's value arguments.
1818 * @param typeargtypes The method's type arguments.
1819 * @param allowBoxing Allow boxing conversions of arguments.
1820 * @param useVarargs Box trailing arguments into an array for varargs.
1821 */
1822 Symbol findFun(Env<AttrContext> env, Name name,
1823 List<Type> argtypes, List<Type> typeargtypes,
1824 boolean allowBoxing, boolean useVarargs) {
1825 Symbol bestSoFar = methodNotFound;
1826 Symbol sym;
1827 Env<AttrContext> env1 = env;
1828 boolean staticOnly = false;
1829 while (env1.outer != null) {
1830 if (isStatic(env1)) staticOnly = true;
1831 sym = findMethod(
1832 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
1833 allowBoxing, useVarargs, false);
1834 if (sym.exists()) {
1835 if (staticOnly &&
1836 sym.kind == MTH &&
1837 sym.owner.kind == TYP &&
1838 (sym.flags() & STATIC) == 0) return new StaticError(sym);
1839 else return sym;
1840 } else if (sym.kind < bestSoFar.kind) {
1841 bestSoFar = sym;
1842 }
1843 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1844 env1 = env1.outer;
1845 }
1847 sym = findMethod(env, syms.predefClass.type, name, argtypes,
1848 typeargtypes, allowBoxing, useVarargs, false);
1849 if (sym.exists())
1850 return sym;
1852 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
1853 for (; e.scope != null; e = e.next()) {
1854 sym = e.sym;
1855 Type origin = e.getOrigin().owner.type;
1856 if (sym.kind == MTH) {
1857 if (e.sym.owner.type != origin)
1858 sym = sym.clone(e.getOrigin().owner);
1859 if (!isAccessible(env, origin, sym))
1860 sym = new AccessError(env, origin, sym);
1861 bestSoFar = selectBest(env, origin,
1862 argtypes, typeargtypes,
1863 sym, bestSoFar,
1864 allowBoxing, useVarargs, false);
1865 }
1866 }
1867 if (bestSoFar.exists())
1868 return bestSoFar;
1870 e = env.toplevel.starImportScope.lookup(name);
1871 for (; e.scope != null; e = e.next()) {
1872 sym = e.sym;
1873 Type origin = e.getOrigin().owner.type;
1874 if (sym.kind == MTH) {
1875 if (e.sym.owner.type != origin)
1876 sym = sym.clone(e.getOrigin().owner);
1877 if (!isAccessible(env, origin, sym))
1878 sym = new AccessError(env, origin, sym);
1879 bestSoFar = selectBest(env, origin,
1880 argtypes, typeargtypes,
1881 sym, bestSoFar,
1882 allowBoxing, useVarargs, false);
1883 }
1884 }
1885 return bestSoFar;
1886 }
1888 /** Load toplevel or member class with given fully qualified name and
1889 * verify that it is accessible.
1890 * @param env The current environment.
1891 * @param name The fully qualified name of the class to be loaded.
1892 */
1893 Symbol loadClass(Env<AttrContext> env, Name name) {
1894 try {
1895 ClassSymbol c = reader.loadClass(name);
1896 return isAccessible(env, c) ? c : new AccessError(c);
1897 } catch (ClassReader.BadClassFile err) {
1898 throw err;
1899 } catch (CompletionFailure ex) {
1900 return typeNotFound;
1901 }
1902 }
1905 /**
1906 * Find a type declared in a scope (not inherited). Return null
1907 * if none is found.
1908 * @param env The current environment.
1909 * @param site The original type from where the selection takes
1910 * place.
1911 * @param name The type's name.
1912 * @param c The class to search for the member type. This is
1913 * always a superclass or implemented interface of
1914 * site's class.
1915 */
1916 Symbol findImmediateMemberType(Env<AttrContext> env,
1917 Type site,
1918 Name name,
1919 TypeSymbol c) {
1920 Scope.Entry e = c.members().lookup(name);
1921 while (e.scope != null) {
1922 if (e.sym.kind == TYP) {
1923 return isAccessible(env, site, e.sym)
1924 ? e.sym
1925 : new AccessError(env, site, e.sym);
1926 }
1927 e = e.next();
1928 }
1929 return typeNotFound;
1930 }
1932 /** Find a member type inherited from a superclass or interface.
1933 * @param env The current environment.
1934 * @param site The original type from where the selection takes
1935 * place.
1936 * @param name The type's name.
1937 * @param c The class to search for the member type. This is
1938 * always a superclass or implemented interface of
1939 * site's class.
1940 */
1941 Symbol findInheritedMemberType(Env<AttrContext> env,
1942 Type site,
1943 Name name,
1944 TypeSymbol c) {
1945 Symbol bestSoFar = typeNotFound;
1946 Symbol sym;
1947 Type st = types.supertype(c.type);
1948 if (st != null && st.hasTag(CLASS)) {
1949 sym = findMemberType(env, site, name, st.tsym);
1950 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1951 }
1952 for (List<Type> l = types.interfaces(c.type);
1953 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1954 l = l.tail) {
1955 sym = findMemberType(env, site, name, l.head.tsym);
1956 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1957 sym.owner != bestSoFar.owner)
1958 bestSoFar = new AmbiguityError(bestSoFar, sym);
1959 else if (sym.kind < bestSoFar.kind)
1960 bestSoFar = sym;
1961 }
1962 return bestSoFar;
1963 }
1965 /** Find qualified member type.
1966 * @param env The current environment.
1967 * @param site The original type from where the selection takes
1968 * place.
1969 * @param name The type's name.
1970 * @param c The class to search for the member type. This is
1971 * always a superclass or implemented interface of
1972 * site's class.
1973 */
1974 Symbol findMemberType(Env<AttrContext> env,
1975 Type site,
1976 Name name,
1977 TypeSymbol c) {
1978 Symbol sym = findImmediateMemberType(env, site, name, c);
1980 if (sym != typeNotFound)
1981 return sym;
1983 return findInheritedMemberType(env, site, name, c);
1985 }
1987 /** Find a global type in given scope and load corresponding class.
1988 * @param env The current environment.
1989 * @param scope The scope in which to look for the type.
1990 * @param name The type's name.
1991 */
1992 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) {
1993 Symbol bestSoFar = typeNotFound;
1994 for (Scope.Entry e = scope.lookup(name); e.scope != null; e = e.next()) {
1995 Symbol sym = loadClass(env, e.sym.flatName());
1996 if (bestSoFar.kind == TYP && sym.kind == TYP &&
1997 bestSoFar != sym)
1998 return new AmbiguityError(bestSoFar, sym);
1999 else if (sym.kind < bestSoFar.kind)
2000 bestSoFar = sym;
2001 }
2002 return bestSoFar;
2003 }
2005 Symbol findTypeVar(Env<AttrContext> env, Name name, boolean staticOnly) {
2006 for (Scope.Entry e = env.info.scope.lookup(name);
2007 e.scope != null;
2008 e = e.next()) {
2009 if (e.sym.kind == TYP) {
2010 if (staticOnly &&
2011 e.sym.type.hasTag(TYPEVAR) &&
2012 e.sym.owner.kind == TYP)
2013 return new StaticError(e.sym);
2014 return e.sym;
2015 }
2016 }
2017 return typeNotFound;
2018 }
2020 /** Find an unqualified type symbol.
2021 * @param env The current environment.
2022 * @param name The type's name.
2023 */
2024 Symbol findType(Env<AttrContext> env, Name name) {
2025 Symbol bestSoFar = typeNotFound;
2026 Symbol sym;
2027 boolean staticOnly = false;
2028 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
2029 if (isStatic(env1)) staticOnly = true;
2030 // First, look for a type variable and the first member type
2031 final Symbol tyvar = findTypeVar(env1, name, staticOnly);
2032 sym = findImmediateMemberType(env1, env1.enclClass.sym.type,
2033 name, env1.enclClass.sym);
2035 // Return the type variable if we have it, and have no
2036 // immediate member, OR the type variable is for a method.
2037 if (tyvar != typeNotFound) {
2038 if (sym == typeNotFound ||
2039 (tyvar.kind == TYP && tyvar.exists() &&
2040 tyvar.owner.kind == MTH))
2041 return tyvar;
2042 }
2044 // If the environment is a class def, finish up,
2045 // otherwise, do the entire findMemberType
2046 if (sym == typeNotFound)
2047 sym = findInheritedMemberType(env1, env1.enclClass.sym.type,
2048 name, env1.enclClass.sym);
2050 if (staticOnly && sym.kind == TYP &&
2051 sym.type.hasTag(CLASS) &&
2052 sym.type.getEnclosingType().hasTag(CLASS) &&
2053 env1.enclClass.sym.type.isParameterized() &&
2054 sym.type.getEnclosingType().isParameterized())
2055 return new StaticError(sym);
2056 else if (sym.exists()) return sym;
2057 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2059 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
2060 if ((encl.sym.flags() & STATIC) != 0)
2061 staticOnly = true;
2062 }
2064 if (!env.tree.hasTag(IMPORT)) {
2065 sym = findGlobalType(env, env.toplevel.namedImportScope, name);
2066 if (sym.exists()) return sym;
2067 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2069 sym = findGlobalType(env, env.toplevel.packge.members(), name);
2070 if (sym.exists()) return sym;
2071 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2073 sym = findGlobalType(env, env.toplevel.starImportScope, name);
2074 if (sym.exists()) return sym;
2075 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2076 }
2078 return bestSoFar;
2079 }
2081 /** Find an unqualified identifier which matches a specified kind set.
2082 * @param env The current environment.
2083 * @param name The identifier's name.
2084 * @param kind Indicates the possible symbol kinds
2085 * (a subset of VAL, TYP, PCK).
2086 */
2087 Symbol findIdent(Env<AttrContext> env, Name name, int kind) {
2088 Symbol bestSoFar = typeNotFound;
2089 Symbol sym;
2091 if ((kind & VAR) != 0) {
2092 sym = findVar(env, name);
2093 if (sym.exists()) return sym;
2094 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2095 }
2097 if ((kind & TYP) != 0) {
2098 sym = findType(env, name);
2099 if (sym.kind==TYP) {
2100 reportDependence(env.enclClass.sym, sym);
2101 }
2102 if (sym.exists()) return sym;
2103 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2104 }
2106 if ((kind & PCK) != 0) return reader.enterPackage(name);
2107 else return bestSoFar;
2108 }
2110 /** Report dependencies.
2111 * @param from The enclosing class sym
2112 * @param to The found identifier that the class depends on.
2113 */
2114 public void reportDependence(Symbol from, Symbol to) {
2115 // Override if you want to collect the reported dependencies.
2116 }
2118 /** Find an identifier in a package which matches a specified kind set.
2119 * @param env The current environment.
2120 * @param name The identifier's name.
2121 * @param kind Indicates the possible symbol kinds
2122 * (a nonempty subset of TYP, PCK).
2123 */
2124 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
2125 Name name, int kind) {
2126 Name fullname = TypeSymbol.formFullName(name, pck);
2127 Symbol bestSoFar = typeNotFound;
2128 PackageSymbol pack = null;
2129 if ((kind & PCK) != 0) {
2130 pack = reader.enterPackage(fullname);
2131 if (pack.exists()) return pack;
2132 }
2133 if ((kind & TYP) != 0) {
2134 Symbol sym = loadClass(env, fullname);
2135 if (sym.exists()) {
2136 // don't allow programs to use flatnames
2137 if (name == sym.name) return sym;
2138 }
2139 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2140 }
2141 return (pack != null) ? pack : bestSoFar;
2142 }
2144 /** Find an identifier among the members of a given type `site'.
2145 * @param env The current environment.
2146 * @param site The type containing the symbol to be found.
2147 * @param name The identifier's name.
2148 * @param kind Indicates the possible symbol kinds
2149 * (a subset of VAL, TYP).
2150 */
2151 Symbol findIdentInType(Env<AttrContext> env, Type site,
2152 Name name, int kind) {
2153 Symbol bestSoFar = typeNotFound;
2154 Symbol sym;
2155 if ((kind & VAR) != 0) {
2156 sym = findField(env, site, name, site.tsym);
2157 if (sym.exists()) return sym;
2158 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2159 }
2161 if ((kind & TYP) != 0) {
2162 sym = findMemberType(env, site, name, site.tsym);
2163 if (sym.exists()) return sym;
2164 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
2165 }
2166 return bestSoFar;
2167 }
2169 /* ***************************************************************************
2170 * Access checking
2171 * The following methods convert ResolveErrors to ErrorSymbols, issuing
2172 * an error message in the process
2173 ****************************************************************************/
2175 /** If `sym' is a bad symbol: report error and return errSymbol
2176 * else pass through unchanged,
2177 * additional arguments duplicate what has been used in trying to find the
2178 * symbol {@literal (--> flyweight pattern)}. This improves performance since we
2179 * expect misses to happen frequently.
2180 *
2181 * @param sym The symbol that was found, or a ResolveError.
2182 * @param pos The position to use for error reporting.
2183 * @param location The symbol the served as a context for this lookup
2184 * @param site The original type from where the selection took place.
2185 * @param name The symbol's name.
2186 * @param qualified Did we get here through a qualified expression resolution?
2187 * @param argtypes The invocation's value arguments,
2188 * if we looked for a method.
2189 * @param typeargtypes The invocation's type arguments,
2190 * if we looked for a method.
2191 * @param logResolveHelper helper class used to log resolve errors
2192 */
2193 Symbol accessInternal(Symbol sym,
2194 DiagnosticPosition pos,
2195 Symbol location,
2196 Type site,
2197 Name name,
2198 boolean qualified,
2199 List<Type> argtypes,
2200 List<Type> typeargtypes,
2201 LogResolveHelper logResolveHelper) {
2202 if (sym.kind >= AMBIGUOUS) {
2203 ResolveError errSym = (ResolveError)sym.baseSymbol();
2204 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
2205 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes);
2206 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) {
2207 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
2208 }
2209 }
2210 return sym;
2211 }
2213 /**
2214 * Variant of the generalized access routine, to be used for generating method
2215 * resolution diagnostics
2216 */
2217 Symbol accessMethod(Symbol sym,
2218 DiagnosticPosition pos,
2219 Symbol location,
2220 Type site,
2221 Name name,
2222 boolean qualified,
2223 List<Type> argtypes,
2224 List<Type> typeargtypes) {
2225 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper);
2226 }
2228 /** Same as original accessMethod(), but without location.
2229 */
2230 Symbol accessMethod(Symbol sym,
2231 DiagnosticPosition pos,
2232 Type site,
2233 Name name,
2234 boolean qualified,
2235 List<Type> argtypes,
2236 List<Type> typeargtypes) {
2237 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
2238 }
2240 /**
2241 * Variant of the generalized access routine, to be used for generating variable,
2242 * type resolution diagnostics
2243 */
2244 Symbol accessBase(Symbol sym,
2245 DiagnosticPosition pos,
2246 Symbol location,
2247 Type site,
2248 Name name,
2249 boolean qualified) {
2250 return accessInternal(sym, pos, location, site, name, qualified, List.<Type>nil(), null, basicLogResolveHelper);
2251 }
2253 /** Same as original accessBase(), but without location.
2254 */
2255 Symbol accessBase(Symbol sym,
2256 DiagnosticPosition pos,
2257 Type site,
2258 Name name,
2259 boolean qualified) {
2260 return accessBase(sym, pos, site.tsym, site, name, qualified);
2261 }
2263 interface LogResolveHelper {
2264 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes);
2265 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes);
2266 }
2268 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() {
2269 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2270 return !site.isErroneous();
2271 }
2272 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2273 return argtypes;
2274 }
2275 };
2277 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() {
2278 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2279 return !site.isErroneous() &&
2280 !Type.isErroneous(argtypes) &&
2281 (typeargtypes == null || !Type.isErroneous(typeargtypes));
2282 }
2283 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2284 return (syms.operatorNames.contains(name)) ?
2285 argtypes :
2286 Type.map(argtypes, new ResolveDeferredRecoveryMap(AttrMode.SPECULATIVE, accessedSym, currentResolutionContext.step));
2287 }
2288 };
2290 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap {
2292 public ResolveDeferredRecoveryMap(AttrMode mode, Symbol msym, MethodResolutionPhase step) {
2293 deferredAttr.super(mode, msym, step);
2294 }
2296 @Override
2297 protected Type typeOf(DeferredType dt) {
2298 Type res = super.typeOf(dt);
2299 if (!res.isErroneous()) {
2300 switch (TreeInfo.skipParens(dt.tree).getTag()) {
2301 case LAMBDA:
2302 case REFERENCE:
2303 return dt;
2304 case CONDEXPR:
2305 return res == Type.recoveryType ?
2306 dt : res;
2307 }
2308 }
2309 return res;
2310 }
2311 }
2313 /** Check that sym is not an abstract method.
2314 */
2315 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
2316 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0)
2317 log.error(pos, "abstract.cant.be.accessed.directly",
2318 kindName(sym), sym, sym.location());
2319 }
2321 /* ***************************************************************************
2322 * Debugging
2323 ****************************************************************************/
2325 /** print all scopes starting with scope s and proceeding outwards.
2326 * used for debugging.
2327 */
2328 public void printscopes(Scope s) {
2329 while (s != null) {
2330 if (s.owner != null)
2331 System.err.print(s.owner + ": ");
2332 for (Scope.Entry e = s.elems; e != null; e = e.sibling) {
2333 if ((e.sym.flags() & ABSTRACT) != 0)
2334 System.err.print("abstract ");
2335 System.err.print(e.sym + " ");
2336 }
2337 System.err.println();
2338 s = s.next;
2339 }
2340 }
2342 void printscopes(Env<AttrContext> env) {
2343 while (env.outer != null) {
2344 System.err.println("------------------------------");
2345 printscopes(env.info.scope);
2346 env = env.outer;
2347 }
2348 }
2350 public void printscopes(Type t) {
2351 while (t.hasTag(CLASS)) {
2352 printscopes(t.tsym.members());
2353 t = types.supertype(t);
2354 }
2355 }
2357 /* ***************************************************************************
2358 * Name resolution
2359 * Naming conventions are as for symbol lookup
2360 * Unlike the find... methods these methods will report access errors
2361 ****************************************************************************/
2363 /** Resolve an unqualified (non-method) identifier.
2364 * @param pos The position to use for error reporting.
2365 * @param env The environment current at the identifier use.
2366 * @param name The identifier's name.
2367 * @param kind The set of admissible symbol kinds for the identifier.
2368 */
2369 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
2370 Name name, int kind) {
2371 return accessBase(
2372 findIdent(env, name, kind),
2373 pos, env.enclClass.sym.type, name, false);
2374 }
2376 /** Resolve an unqualified method identifier.
2377 * @param pos The position to use for error reporting.
2378 * @param env The environment current at the method invocation.
2379 * @param name The identifier's name.
2380 * @param argtypes The types of the invocation's value arguments.
2381 * @param typeargtypes The types of the invocation's type arguments.
2382 */
2383 Symbol resolveMethod(DiagnosticPosition pos,
2384 Env<AttrContext> env,
2385 Name name,
2386 List<Type> argtypes,
2387 List<Type> typeargtypes) {
2388 return lookupMethod(env, pos, env.enclClass.sym, resolveMethodCheck,
2389 new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) {
2390 @Override
2391 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2392 return findFun(env, name, argtypes, typeargtypes,
2393 phase.isBoxingRequired(),
2394 phase.isVarargsRequired());
2395 }});
2396 }
2398 /** Resolve a qualified method identifier
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 of the qualifying expression, in which
2402 * identifier is searched.
2403 * @param name The identifier's name.
2404 * @param argtypes The types of the invocation's value arguments.
2405 * @param typeargtypes The types of the invocation's type arguments.
2406 */
2407 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2408 Type site, Name name, List<Type> argtypes,
2409 List<Type> typeargtypes) {
2410 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
2411 }
2412 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2413 Symbol location, Type site, Name name, List<Type> argtypes,
2414 List<Type> typeargtypes) {
2415 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
2416 }
2417 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
2418 DiagnosticPosition pos, Env<AttrContext> env,
2419 Symbol location, Type site, Name name, List<Type> argtypes,
2420 List<Type> typeargtypes) {
2421 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) {
2422 @Override
2423 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2424 return findMethod(env, site, name, argtypes, typeargtypes,
2425 phase.isBoxingRequired(),
2426 phase.isVarargsRequired(), false);
2427 }
2428 @Override
2429 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2430 if (sym.kind >= AMBIGUOUS) {
2431 sym = super.access(env, pos, location, sym);
2432 } else if (allowMethodHandles) {
2433 MethodSymbol msym = (MethodSymbol)sym;
2434 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) {
2435 return findPolymorphicSignatureInstance(env, sym, argtypes);
2436 }
2437 }
2438 return sym;
2439 }
2440 });
2441 }
2443 /** Find or create an implicit method of exactly the given type (after erasure).
2444 * Searches in a side table, not the main scope of the site.
2445 * This emulates the lookup process required by JSR 292 in JVM.
2446 * @param env Attribution environment
2447 * @param spMethod signature polymorphic method - i.e. MH.invokeExact
2448 * @param argtypes The required argument types
2449 */
2450 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env,
2451 final Symbol spMethod,
2452 List<Type> argtypes) {
2453 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
2454 (MethodSymbol)spMethod, currentResolutionContext, argtypes);
2455 for (Symbol sym : polymorphicSignatureScope.getElementsByName(spMethod.name)) {
2456 if (types.isSameType(mtype, sym.type)) {
2457 return sym;
2458 }
2459 }
2461 // create the desired method
2462 long flags = ABSTRACT | HYPOTHETICAL | spMethod.flags() & Flags.AccessFlags;
2463 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) {
2464 @Override
2465 public Symbol baseSymbol() {
2466 return spMethod;
2467 }
2468 };
2469 polymorphicSignatureScope.enter(msym);
2470 return msym;
2471 }
2473 /** Resolve a qualified method identifier, throw a fatal error if not
2474 * found.
2475 * @param pos The position to use for error reporting.
2476 * @param env The environment current at the method invocation.
2477 * @param site The type of the qualifying expression, in which
2478 * identifier is searched.
2479 * @param name The identifier's name.
2480 * @param argtypes The types of the invocation's value arguments.
2481 * @param typeargtypes The types of the invocation's type arguments.
2482 */
2483 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
2484 Type site, Name name,
2485 List<Type> argtypes,
2486 List<Type> typeargtypes) {
2487 MethodResolutionContext resolveContext = new MethodResolutionContext();
2488 resolveContext.internalResolution = true;
2489 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
2490 site, name, argtypes, typeargtypes);
2491 if (sym.kind == MTH) return (MethodSymbol)sym;
2492 else throw new FatalError(
2493 diags.fragment("fatal.err.cant.locate.meth",
2494 name));
2495 }
2497 /** Resolve constructor.
2498 * @param pos The position to use for error reporting.
2499 * @param env The environment current at the constructor invocation.
2500 * @param site The type of class for which a constructor is searched.
2501 * @param argtypes The types of the constructor invocation's value
2502 * arguments.
2503 * @param typeargtypes The types of the constructor invocation's type
2504 * arguments.
2505 */
2506 Symbol resolveConstructor(DiagnosticPosition pos,
2507 Env<AttrContext> env,
2508 Type site,
2509 List<Type> argtypes,
2510 List<Type> typeargtypes) {
2511 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
2512 }
2514 private Symbol resolveConstructor(MethodResolutionContext resolveContext,
2515 final DiagnosticPosition pos,
2516 Env<AttrContext> env,
2517 Type site,
2518 List<Type> argtypes,
2519 List<Type> typeargtypes) {
2520 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2521 @Override
2522 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2523 return findConstructor(pos, env, site, argtypes, typeargtypes,
2524 phase.isBoxingRequired(),
2525 phase.isVarargsRequired());
2526 }
2527 });
2528 }
2530 /** Resolve a constructor, throw a fatal error if not found.
2531 * @param pos The position to use for error reporting.
2532 * @param env The environment current at the method invocation.
2533 * @param site The type to be constructed.
2534 * @param argtypes The types of the invocation's value arguments.
2535 * @param typeargtypes The types of the invocation's type arguments.
2536 */
2537 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2538 Type site,
2539 List<Type> argtypes,
2540 List<Type> typeargtypes) {
2541 MethodResolutionContext resolveContext = new MethodResolutionContext();
2542 resolveContext.internalResolution = true;
2543 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
2544 if (sym.kind == MTH) return (MethodSymbol)sym;
2545 else throw new FatalError(
2546 diags.fragment("fatal.err.cant.locate.ctor", site));
2547 }
2549 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2550 Type site, List<Type> argtypes,
2551 List<Type> typeargtypes,
2552 boolean allowBoxing,
2553 boolean useVarargs) {
2554 Symbol sym = findMethod(env, site,
2555 names.init, argtypes,
2556 typeargtypes, allowBoxing,
2557 useVarargs, false);
2558 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2559 return sym;
2560 }
2562 /** Resolve constructor using diamond inference.
2563 * @param pos The position to use for error reporting.
2564 * @param env The environment current at the constructor invocation.
2565 * @param site The type of class for which a constructor is searched.
2566 * The scope of this class has been touched in attribution.
2567 * @param argtypes The types of the constructor invocation's value
2568 * arguments.
2569 * @param typeargtypes The types of the constructor invocation's type
2570 * arguments.
2571 */
2572 Symbol resolveDiamond(DiagnosticPosition pos,
2573 Env<AttrContext> env,
2574 Type site,
2575 List<Type> argtypes,
2576 List<Type> typeargtypes) {
2577 return lookupMethod(env, pos, site.tsym, resolveMethodCheck,
2578 new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2579 @Override
2580 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2581 return findDiamond(env, site, argtypes, typeargtypes,
2582 phase.isBoxingRequired(),
2583 phase.isVarargsRequired());
2584 }
2585 @Override
2586 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2587 if (sym.kind >= AMBIGUOUS) {
2588 if (sym.kind != WRONG_MTH && sym.kind != WRONG_MTHS) {
2589 sym = super.access(env, pos, location, sym);
2590 } else {
2591 final JCDiagnostic details = sym.kind == WRONG_MTH ?
2592 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd :
2593 null;
2594 sym = new InapplicableSymbolError(sym.kind, "diamondError", currentResolutionContext) {
2595 @Override
2596 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
2597 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
2598 String key = details == null ?
2599 "cant.apply.diamond" :
2600 "cant.apply.diamond.1";
2601 return diags.create(dkind, log.currentSource(), pos, key,
2602 diags.fragment("diamond", site.tsym), details);
2603 }
2604 };
2605 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes);
2606 env.info.pendingResolutionPhase = currentResolutionContext.step;
2607 }
2608 }
2609 return sym;
2610 }});
2611 }
2613 /** This method scans all the constructor symbol in a given class scope -
2614 * assuming that the original scope contains a constructor of the kind:
2615 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
2616 * a method check is executed against the modified constructor type:
2617 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond
2618 * inference. The inferred return type of the synthetic constructor IS
2619 * the inferred type for the diamond operator.
2620 */
2621 private Symbol findDiamond(Env<AttrContext> env,
2622 Type site,
2623 List<Type> argtypes,
2624 List<Type> typeargtypes,
2625 boolean allowBoxing,
2626 boolean useVarargs) {
2627 Symbol bestSoFar = methodNotFound;
2628 for (Scope.Entry e = site.tsym.members().lookup(names.init);
2629 e.scope != null;
2630 e = e.next()) {
2631 final Symbol sym = e.sym;
2632 //- System.out.println(" e " + e.sym);
2633 if (sym.kind == MTH &&
2634 (sym.flags_field & SYNTHETIC) == 0) {
2635 List<Type> oldParams = e.sym.type.hasTag(FORALL) ?
2636 ((ForAll)sym.type).tvars :
2637 List.<Type>nil();
2638 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
2639 types.createMethodTypeWithReturn(sym.type.asMethodType(), site));
2640 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) {
2641 @Override
2642 public Symbol baseSymbol() {
2643 return sym;
2644 }
2645 };
2646 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
2647 newConstr,
2648 bestSoFar,
2649 allowBoxing,
2650 useVarargs,
2651 false);
2652 }
2653 }
2654 return bestSoFar;
2655 }
2659 /** Resolve operator.
2660 * @param pos The position to use for error reporting.
2661 * @param optag The tag of the operation tree.
2662 * @param env The environment current at the operation.
2663 * @param argtypes The types of the operands.
2664 */
2665 Symbol resolveOperator(DiagnosticPosition pos, JCTree.Tag optag,
2666 Env<AttrContext> env, List<Type> argtypes) {
2667 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2668 try {
2669 currentResolutionContext = new MethodResolutionContext();
2670 Name name = treeinfo.operatorName(optag);
2671 return lookupMethod(env, pos, syms.predefClass, currentResolutionContext,
2672 new BasicLookupHelper(name, syms.predefClass.type, argtypes, null, BOX) {
2673 @Override
2674 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2675 return findMethod(env, site, name, argtypes, typeargtypes,
2676 phase.isBoxingRequired(),
2677 phase.isVarargsRequired(), true);
2678 }
2679 @Override
2680 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2681 return accessMethod(sym, pos, env.enclClass.sym.type, name,
2682 false, argtypes, null);
2683 }
2684 });
2685 } finally {
2686 currentResolutionContext = prevResolutionContext;
2687 }
2688 }
2690 /** Resolve operator.
2691 * @param pos The position to use for error reporting.
2692 * @param optag The tag of the operation tree.
2693 * @param env The environment current at the operation.
2694 * @param arg The type of the operand.
2695 */
2696 Symbol resolveUnaryOperator(DiagnosticPosition pos, JCTree.Tag optag, Env<AttrContext> env, Type arg) {
2697 return resolveOperator(pos, optag, env, List.of(arg));
2698 }
2700 /** Resolve binary operator.
2701 * @param pos The position to use for error reporting.
2702 * @param optag The tag of the operation tree.
2703 * @param env The environment current at the operation.
2704 * @param left The types of the left operand.
2705 * @param right The types of the right operand.
2706 */
2707 Symbol resolveBinaryOperator(DiagnosticPosition pos,
2708 JCTree.Tag optag,
2709 Env<AttrContext> env,
2710 Type left,
2711 Type right) {
2712 return resolveOperator(pos, optag, env, List.of(left, right));
2713 }
2715 Symbol getMemberReference(DiagnosticPosition pos,
2716 Env<AttrContext> env,
2717 JCMemberReference referenceTree,
2718 Type site,
2719 Name name) {
2721 site = types.capture(site);
2723 ReferenceLookupHelper lookupHelper = makeReferenceLookupHelper(
2724 referenceTree, site, name, List.<Type>nil(), null, VARARITY);
2726 Env<AttrContext> newEnv = env.dup(env.tree, env.info.dup());
2727 Symbol sym = lookupMethod(newEnv, env.tree.pos(), site.tsym,
2728 nilMethodCheck, lookupHelper);
2730 env.info.pendingResolutionPhase = newEnv.info.pendingResolutionPhase;
2732 return sym;
2733 }
2735 ReferenceLookupHelper makeReferenceLookupHelper(JCMemberReference referenceTree,
2736 Type site,
2737 Name name,
2738 List<Type> argtypes,
2739 List<Type> typeargtypes,
2740 MethodResolutionPhase maxPhase) {
2741 ReferenceLookupHelper result;
2742 if (!name.equals(names.init)) {
2743 //method reference
2744 result =
2745 new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2746 } else {
2747 if (site.hasTag(ARRAY)) {
2748 //array constructor reference
2749 result =
2750 new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2751 } else {
2752 //class constructor reference
2753 result =
2754 new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2755 }
2756 }
2757 return result;
2758 }
2760 Symbol resolveMemberReferenceByArity(Env<AttrContext> env,
2761 JCMemberReference referenceTree,
2762 Type site,
2763 Name name,
2764 List<Type> argtypes,
2765 InferenceContext inferenceContext) {
2767 boolean isStaticSelector = TreeInfo.isStaticSelector(referenceTree.expr, names);
2768 site = types.capture(site);
2770 ReferenceLookupHelper boundLookupHelper = makeReferenceLookupHelper(
2771 referenceTree, site, name, argtypes, null, VARARITY);
2772 //step 1 - bound lookup
2773 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup());
2774 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(), site.tsym,
2775 arityMethodCheck, boundLookupHelper);
2776 if (isStaticSelector &&
2777 !name.equals(names.init) &&
2778 !boundSym.isStatic() &&
2779 boundSym.kind < ERRONEOUS) {
2780 boundSym = methodNotFound;
2781 }
2783 //step 2 - unbound lookup
2784 Symbol unboundSym = methodNotFound;
2785 ReferenceLookupHelper unboundLookupHelper = null;
2786 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup());
2787 if (isStaticSelector) {
2788 unboundLookupHelper = boundLookupHelper.unboundLookup(inferenceContext);
2789 unboundSym = lookupMethod(unboundEnv, env.tree.pos(), site.tsym,
2790 arityMethodCheck, unboundLookupHelper);
2791 if (unboundSym.isStatic() &&
2792 unboundSym.kind < ERRONEOUS) {
2793 unboundSym = methodNotFound;
2794 }
2795 }
2797 //merge results
2798 Symbol bestSym = choose(boundSym, unboundSym);
2799 env.info.pendingResolutionPhase = bestSym == unboundSym ?
2800 unboundEnv.info.pendingResolutionPhase :
2801 boundEnv.info.pendingResolutionPhase;
2803 return bestSym;
2804 }
2806 /**
2807 * Resolution of member references is typically done as a single
2808 * overload resolution step, where the argument types A are inferred from
2809 * the target functional descriptor.
2810 *
2811 * If the member reference is a method reference with a type qualifier,
2812 * a two-step lookup process is performed. The first step uses the
2813 * expected argument list A, while the second step discards the first
2814 * type from A (which is treated as a receiver type).
2815 *
2816 * There are two cases in which inference is performed: (i) if the member
2817 * reference is a constructor reference and the qualifier type is raw - in
2818 * which case diamond inference is used to infer a parameterization for the
2819 * type qualifier; (ii) if the member reference is an unbound reference
2820 * where the type qualifier is raw - in that case, during the unbound lookup
2821 * the receiver argument type is used to infer an instantiation for the raw
2822 * qualifier type.
2823 *
2824 * When a multi-step resolution process is exploited, it is an error
2825 * if two candidates are found (ambiguity).
2826 *
2827 * This routine returns a pair (T,S), where S is the member reference symbol,
2828 * and T is the type of the class in which S is defined. This is necessary as
2829 * the type T might be dynamically inferred (i.e. if constructor reference
2830 * has a raw qualifier).
2831 */
2832 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(Env<AttrContext> env,
2833 JCMemberReference referenceTree,
2834 Type site,
2835 Name name,
2836 List<Type> argtypes,
2837 List<Type> typeargtypes,
2838 MethodCheck methodCheck,
2839 InferenceContext inferenceContext,
2840 AttrMode mode) {
2842 site = types.capture(site);
2843 ReferenceLookupHelper boundLookupHelper = makeReferenceLookupHelper(
2844 referenceTree, site, name, argtypes, typeargtypes, VARARITY);
2846 //step 1 - bound lookup
2847 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup());
2848 Symbol origBoundSym;
2849 boolean staticErrorForBound = false;
2850 MethodResolutionContext boundSearchResolveContext = new MethodResolutionContext();
2851 boundSearchResolveContext.methodCheck = methodCheck;
2852 Symbol boundSym = origBoundSym = lookupMethod(boundEnv, env.tree.pos(),
2853 site.tsym, boundSearchResolveContext, boundLookupHelper);
2854 SearchResultKind boundSearchResultKind = SearchResultKind.NOT_APPLICABLE_MATCH;
2855 boolean isStaticSelector = TreeInfo.isStaticSelector(referenceTree.expr, names);
2856 boolean shouldCheckForStaticness = isStaticSelector &&
2857 referenceTree.getMode() == ReferenceMode.INVOKE;
2858 if (boundSym.kind != WRONG_MTHS && boundSym.kind != WRONG_MTH) {
2859 if (shouldCheckForStaticness) {
2860 if (!boundSym.isStatic()) {
2861 staticErrorForBound = true;
2862 if (hasAnotherApplicableMethod(
2863 boundSearchResolveContext, boundSym, true)) {
2864 boundSearchResultKind = SearchResultKind.BAD_MATCH_MORE_SPECIFIC;
2865 } else {
2866 boundSearchResultKind = SearchResultKind.BAD_MATCH;
2867 if (boundSym.kind < ERRONEOUS) {
2868 boundSym = methodWithCorrectStaticnessNotFound;
2869 }
2870 }
2871 } else if (boundSym.kind < ERRONEOUS) {
2872 boundSearchResultKind = SearchResultKind.GOOD_MATCH;
2873 }
2874 }
2875 }
2877 //step 2 - unbound lookup
2878 Symbol origUnboundSym = null;
2879 Symbol unboundSym = methodNotFound;
2880 ReferenceLookupHelper unboundLookupHelper = null;
2881 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup());
2882 SearchResultKind unboundSearchResultKind = SearchResultKind.NOT_APPLICABLE_MATCH;
2883 boolean staticErrorForUnbound = false;
2884 if (isStaticSelector) {
2885 unboundLookupHelper = boundLookupHelper.unboundLookup(inferenceContext);
2886 MethodResolutionContext unboundSearchResolveContext =
2887 new MethodResolutionContext();
2888 unboundSearchResolveContext.methodCheck = methodCheck;
2889 unboundSym = origUnboundSym = lookupMethod(unboundEnv, env.tree.pos(),
2890 site.tsym, unboundSearchResolveContext, unboundLookupHelper);
2892 if (unboundSym.kind != WRONG_MTH && unboundSym.kind != WRONG_MTHS) {
2893 if (shouldCheckForStaticness) {
2894 if (unboundSym.isStatic()) {
2895 staticErrorForUnbound = true;
2896 if (hasAnotherApplicableMethod(
2897 unboundSearchResolveContext, unboundSym, false)) {
2898 unboundSearchResultKind = SearchResultKind.BAD_MATCH_MORE_SPECIFIC;
2899 } else {
2900 unboundSearchResultKind = SearchResultKind.BAD_MATCH;
2901 if (unboundSym.kind < ERRONEOUS) {
2902 unboundSym = methodWithCorrectStaticnessNotFound;
2903 }
2904 }
2905 } else if (unboundSym.kind < ERRONEOUS) {
2906 unboundSearchResultKind = SearchResultKind.GOOD_MATCH;
2907 }
2908 }
2909 }
2910 }
2912 //merge results
2913 Pair<Symbol, ReferenceLookupHelper> res;
2914 Symbol bestSym = choose(boundSym, unboundSym);
2915 if (bestSym.kind < ERRONEOUS && (staticErrorForBound || staticErrorForUnbound)) {
2916 if (staticErrorForBound) {
2917 boundSym = methodWithCorrectStaticnessNotFound;
2918 }
2919 if (staticErrorForUnbound) {
2920 unboundSym = methodWithCorrectStaticnessNotFound;
2921 }
2922 bestSym = choose(boundSym, unboundSym);
2923 }
2924 if (bestSym == methodWithCorrectStaticnessNotFound && mode == AttrMode.CHECK) {
2925 Symbol symToPrint = origBoundSym;
2926 String errorFragmentToPrint = "non-static.cant.be.ref";
2927 if (staticErrorForBound && staticErrorForUnbound) {
2928 if (unboundSearchResultKind == SearchResultKind.BAD_MATCH_MORE_SPECIFIC) {
2929 symToPrint = origUnboundSym;
2930 errorFragmentToPrint = "static.method.in.unbound.lookup";
2931 }
2932 } else {
2933 if (!staticErrorForBound) {
2934 symToPrint = origUnboundSym;
2935 errorFragmentToPrint = "static.method.in.unbound.lookup";
2936 }
2937 }
2938 log.error(referenceTree.expr.pos(), "invalid.mref",
2939 Kinds.kindName(referenceTree.getMode()),
2940 diags.fragment(errorFragmentToPrint,
2941 Kinds.kindName(symToPrint), symToPrint));
2942 }
2943 res = new Pair<>(bestSym,
2944 bestSym == unboundSym ? unboundLookupHelper : boundLookupHelper);
2945 env.info.pendingResolutionPhase = bestSym == unboundSym ?
2946 unboundEnv.info.pendingResolutionPhase :
2947 boundEnv.info.pendingResolutionPhase;
2949 return res;
2950 }
2952 enum SearchResultKind {
2953 GOOD_MATCH, //type I
2954 BAD_MATCH_MORE_SPECIFIC, //type II
2955 BAD_MATCH, //type III
2956 NOT_APPLICABLE_MATCH //type IV
2957 }
2959 boolean hasAnotherApplicableMethod(MethodResolutionContext resolutionContext,
2960 Symbol bestSoFar, boolean staticMth) {
2961 for (Candidate c : resolutionContext.candidates) {
2962 if (resolutionContext.step != c.step ||
2963 !c.isApplicable() ||
2964 c.sym == bestSoFar) {
2965 continue;
2966 } else {
2967 if (c.sym.isStatic() == staticMth) {
2968 return true;
2969 }
2970 }
2971 }
2972 return false;
2973 }
2975 //where
2976 private Symbol choose(Symbol boundSym, Symbol unboundSym) {
2977 if (lookupSuccess(boundSym) && lookupSuccess(unboundSym)) {
2978 return ambiguityError(boundSym, unboundSym);
2979 } else if (lookupSuccess(boundSym) ||
2980 (canIgnore(unboundSym) && !canIgnore(boundSym))) {
2981 return boundSym;
2982 } else if (lookupSuccess(unboundSym) ||
2983 (canIgnore(boundSym) && !canIgnore(unboundSym))) {
2984 return unboundSym;
2985 } else {
2986 return boundSym;
2987 }
2988 }
2990 private boolean lookupSuccess(Symbol s) {
2991 return s.kind == MTH || s.kind == AMBIGUOUS;
2992 }
2994 private boolean canIgnore(Symbol s) {
2995 switch (s.kind) {
2996 case ABSENT_MTH:
2997 return true;
2998 case WRONG_MTH:
2999 InapplicableSymbolError errSym =
3000 (InapplicableSymbolError)s.baseSymbol();
3001 return new Template(MethodCheckDiag.ARITY_MISMATCH.regex())
3002 .matches(errSym.errCandidate().snd);
3003 case WRONG_MTHS:
3004 InapplicableSymbolsError errSyms =
3005 (InapplicableSymbolsError)s.baseSymbol();
3006 return errSyms.filterCandidates(errSyms.mapCandidates()).isEmpty();
3007 case WRONG_STATICNESS:
3008 return false;
3009 default:
3010 return false;
3011 }
3012 }
3014 /**
3015 * Helper for defining custom method-like lookup logic; a lookup helper
3016 * provides hooks for (i) the actual lookup logic and (ii) accessing the
3017 * lookup result (this step might result in compiler diagnostics to be generated)
3018 */
3019 abstract class LookupHelper {
3021 /** name of the symbol to lookup */
3022 Name name;
3024 /** location in which the lookup takes place */
3025 Type site;
3027 /** actual types used during the lookup */
3028 List<Type> argtypes;
3030 /** type arguments used during the lookup */
3031 List<Type> typeargtypes;
3033 /** Max overload resolution phase handled by this helper */
3034 MethodResolutionPhase maxPhase;
3036 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3037 this.name = name;
3038 this.site = site;
3039 this.argtypes = argtypes;
3040 this.typeargtypes = typeargtypes;
3041 this.maxPhase = maxPhase;
3042 }
3044 /**
3045 * Should lookup stop at given phase with given result
3046 */
3047 final boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
3048 return phase.ordinal() > maxPhase.ordinal() ||
3049 sym.kind < ERRONEOUS || sym.kind == AMBIGUOUS;
3050 }
3052 /**
3053 * Search for a symbol under a given overload resolution phase - this method
3054 * is usually called several times, once per each overload resolution phase
3055 */
3056 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase);
3058 /**
3059 * Dump overload resolution info
3060 */
3061 void debug(DiagnosticPosition pos, Symbol sym) {
3062 //do nothing
3063 }
3065 /**
3066 * Validate the result of the lookup
3067 */
3068 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym);
3069 }
3071 abstract class BasicLookupHelper extends LookupHelper {
3073 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) {
3074 this(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY);
3075 }
3077 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3078 super(name, site, argtypes, typeargtypes, maxPhase);
3079 }
3081 @Override
3082 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3083 Symbol sym = doLookup(env, phase);
3084 if (sym.kind == AMBIGUOUS) {
3085 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
3086 sym = a_err.mergeAbstracts(site);
3087 }
3088 return sym;
3089 }
3091 abstract Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase);
3093 @Override
3094 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
3095 if (sym.kind >= AMBIGUOUS) {
3096 //if nothing is found return the 'first' error
3097 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes);
3098 }
3099 return sym;
3100 }
3102 @Override
3103 void debug(DiagnosticPosition pos, Symbol sym) {
3104 reportVerboseResolutionDiagnostic(pos, name, site, argtypes, typeargtypes, sym);
3105 }
3106 }
3108 /**
3109 * Helper class for member reference lookup. A reference lookup helper
3110 * defines the basic logic for member reference lookup; a method gives
3111 * access to an 'unbound' helper used to perform an unbound member
3112 * reference lookup.
3113 */
3114 abstract class ReferenceLookupHelper extends LookupHelper {
3116 /** The member reference tree */
3117 JCMemberReference referenceTree;
3119 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3120 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3121 super(name, site, argtypes, typeargtypes, maxPhase);
3122 this.referenceTree = referenceTree;
3123 }
3125 /**
3126 * Returns an unbound version of this lookup helper. By default, this
3127 * method returns an dummy lookup helper.
3128 */
3129 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3130 //dummy loopkup helper that always return 'methodNotFound'
3131 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) {
3132 @Override
3133 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3134 return this;
3135 }
3136 @Override
3137 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3138 return methodNotFound;
3139 }
3140 @Override
3141 ReferenceKind referenceKind(Symbol sym) {
3142 Assert.error();
3143 return null;
3144 }
3145 };
3146 }
3148 /**
3149 * Get the kind of the member reference
3150 */
3151 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym);
3153 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
3154 if (sym.kind == AMBIGUOUS) {
3155 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
3156 sym = a_err.mergeAbstracts(site);
3157 }
3158 //skip error reporting
3159 return sym;
3160 }
3161 }
3163 /**
3164 * Helper class for method reference lookup. The lookup logic is based
3165 * upon Resolve.findMethod; in certain cases, this helper class has a
3166 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper).
3167 * In such cases, non-static lookup results are thrown away.
3168 */
3169 class MethodReferenceLookupHelper extends ReferenceLookupHelper {
3171 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3172 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3173 super(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
3174 }
3176 @Override
3177 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3178 return findMethod(env, site, name, argtypes, typeargtypes,
3179 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
3180 }
3182 @Override
3183 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3184 if (TreeInfo.isStaticSelector(referenceTree.expr, names) &&
3185 argtypes.nonEmpty() &&
3186 (argtypes.head.hasTag(NONE) ||
3187 types.isSubtypeUnchecked(inferenceContext.asUndetVar(argtypes.head), site))) {
3188 return new UnboundMethodReferenceLookupHelper(referenceTree, name,
3189 site, argtypes, typeargtypes, maxPhase);
3190 } else {
3191 return super.unboundLookup(inferenceContext);
3192 }
3193 }
3195 @Override
3196 ReferenceKind referenceKind(Symbol sym) {
3197 if (sym.isStatic()) {
3198 return ReferenceKind.STATIC;
3199 } else {
3200 Name selName = TreeInfo.name(referenceTree.getQualifierExpression());
3201 return selName != null && selName == names._super ?
3202 ReferenceKind.SUPER :
3203 ReferenceKind.BOUND;
3204 }
3205 }
3206 }
3208 /**
3209 * Helper class for unbound method reference lookup. Essentially the same
3210 * as the basic method reference lookup helper; main difference is that static
3211 * lookup results are thrown away. If qualifier type is raw, an attempt to
3212 * infer a parameterized type is made using the first actual argument (that
3213 * would otherwise be ignored during the lookup).
3214 */
3215 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper {
3217 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
3218 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3219 super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase);
3220 if (site.isRaw() && !argtypes.head.hasTag(NONE)) {
3221 Type asSuperSite = types.asSuper(argtypes.head, site.tsym);
3222 this.site = types.capture(asSuperSite);
3223 }
3224 }
3226 @Override
3227 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
3228 return this;
3229 }
3231 @Override
3232 ReferenceKind referenceKind(Symbol sym) {
3233 return ReferenceKind.UNBOUND;
3234 }
3235 }
3237 /**
3238 * Helper class for array constructor lookup; an array constructor lookup
3239 * is simulated by looking up a method that returns the array type specified
3240 * as qualifier, and that accepts a single int parameter (size of the array).
3241 */
3242 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper {
3244 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
3245 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3246 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
3247 }
3249 @Override
3250 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3251 Scope sc = new Scope(syms.arrayClass);
3252 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym);
3253 arrayConstr.type = new MethodType(List.<Type>of(syms.intType), site, List.<Type>nil(), syms.methodClass);
3254 sc.enter(arrayConstr);
3255 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false, false);
3256 }
3258 @Override
3259 ReferenceKind referenceKind(Symbol sym) {
3260 return ReferenceKind.ARRAY_CTOR;
3261 }
3262 }
3264 /**
3265 * Helper class for constructor reference lookup. The lookup logic is based
3266 * upon either Resolve.findMethod or Resolve.findDiamond - depending on
3267 * whether the constructor reference needs diamond inference (this is the case
3268 * if the qualifier type is raw). A special erroneous symbol is returned
3269 * if the lookup returns the constructor of an inner class and there's no
3270 * enclosing instance in scope.
3271 */
3272 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper {
3274 boolean needsInference;
3276 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
3277 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
3278 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
3279 if (site.isRaw()) {
3280 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym);
3281 needsInference = true;
3282 }
3283 }
3285 @Override
3286 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
3287 Symbol sym = needsInference ?
3288 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) :
3289 findMethod(env, site, name, argtypes, typeargtypes,
3290 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
3291 return sym.kind != MTH ||
3292 site.getEnclosingType().hasTag(NONE) ||
3293 hasEnclosingInstance(env, site) ?
3294 sym : new InvalidSymbolError(Kinds.MISSING_ENCL, sym, null) {
3295 @Override
3296 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
3297 return diags.create(dkind, log.currentSource(), pos,
3298 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType());
3299 }
3300 };
3301 }
3303 @Override
3304 ReferenceKind referenceKind(Symbol sym) {
3305 return site.getEnclosingType().hasTag(NONE) ?
3306 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER;
3307 }
3308 }
3310 /**
3311 * Main overload resolution routine. On each overload resolution step, a
3312 * lookup helper class is used to perform the method/constructor lookup;
3313 * at the end of the lookup, the helper is used to validate the results
3314 * (this last step might trigger overload resolution diagnostics).
3315 */
3316 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, MethodCheck methodCheck, LookupHelper lookupHelper) {
3317 MethodResolutionContext resolveContext = new MethodResolutionContext();
3318 resolveContext.methodCheck = methodCheck;
3319 return lookupMethod(env, pos, location, resolveContext, lookupHelper);
3320 }
3322 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location,
3323 MethodResolutionContext resolveContext, LookupHelper lookupHelper) {
3324 MethodResolutionContext prevResolutionContext = currentResolutionContext;
3325 try {
3326 Symbol bestSoFar = methodNotFound;
3327 currentResolutionContext = resolveContext;
3328 for (MethodResolutionPhase phase : methodResolutionSteps) {
3329 if (!phase.isApplicable(boxingEnabled, varargsEnabled) ||
3330 lookupHelper.shouldStop(bestSoFar, phase)) break;
3331 MethodResolutionPhase prevPhase = currentResolutionContext.step;
3332 Symbol prevBest = bestSoFar;
3333 currentResolutionContext.step = phase;
3334 Symbol sym = lookupHelper.lookup(env, phase);
3335 lookupHelper.debug(pos, sym);
3336 bestSoFar = phase.mergeResults(bestSoFar, sym);
3337 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase;
3338 }
3339 return lookupHelper.access(env, pos, location, bestSoFar);
3340 } finally {
3341 currentResolutionContext = prevResolutionContext;
3342 }
3343 }
3345 /**
3346 * Resolve `c.name' where name == this or name == super.
3347 * @param pos The position to use for error reporting.
3348 * @param env The environment current at the expression.
3349 * @param c The qualifier.
3350 * @param name The identifier's name.
3351 */
3352 Symbol resolveSelf(DiagnosticPosition pos,
3353 Env<AttrContext> env,
3354 TypeSymbol c,
3355 Name name) {
3356 Env<AttrContext> env1 = env;
3357 boolean staticOnly = false;
3358 while (env1.outer != null) {
3359 if (isStatic(env1)) staticOnly = true;
3360 if (env1.enclClass.sym == c) {
3361 Symbol sym = env1.info.scope.lookup(name).sym;
3362 if (sym != null) {
3363 if (staticOnly) sym = new StaticError(sym);
3364 return accessBase(sym, pos, env.enclClass.sym.type,
3365 name, true);
3366 }
3367 }
3368 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
3369 env1 = env1.outer;
3370 }
3371 if (c.isInterface() &&
3372 name == names._super && !isStatic(env) &&
3373 types.isDirectSuperInterface(c, env.enclClass.sym)) {
3374 //this might be a default super call if one of the superinterfaces is 'c'
3375 for (Type t : pruneInterfaces(env.enclClass.type)) {
3376 if (t.tsym == c) {
3377 env.info.defaultSuperCallSite = t;
3378 return new VarSymbol(0, names._super,
3379 types.asSuper(env.enclClass.type, c), env.enclClass.sym);
3380 }
3381 }
3382 //find a direct superinterface that is a subtype of 'c'
3383 for (Type i : types.interfaces(env.enclClass.type)) {
3384 if (i.tsym.isSubClass(c, types) && i.tsym != c) {
3385 log.error(pos, "illegal.default.super.call", c,
3386 diags.fragment("redundant.supertype", c, i));
3387 return syms.errSymbol;
3388 }
3389 }
3390 Assert.error();
3391 }
3392 log.error(pos, "not.encl.class", c);
3393 return syms.errSymbol;
3394 }
3395 //where
3396 private List<Type> pruneInterfaces(Type t) {
3397 ListBuffer<Type> result = new ListBuffer<>();
3398 for (Type t1 : types.interfaces(t)) {
3399 boolean shouldAdd = true;
3400 for (Type t2 : types.interfaces(t)) {
3401 if (t1 != t2 && types.isSubtypeNoCapture(t2, t1)) {
3402 shouldAdd = false;
3403 }
3404 }
3405 if (shouldAdd) {
3406 result.append(t1);
3407 }
3408 }
3409 return result.toList();
3410 }
3413 /**
3414 * Resolve `c.this' for an enclosing class c that contains the
3415 * named member.
3416 * @param pos The position to use for error reporting.
3417 * @param env The environment current at the expression.
3418 * @param member The member that must be contained in the result.
3419 */
3420 Symbol resolveSelfContaining(DiagnosticPosition pos,
3421 Env<AttrContext> env,
3422 Symbol member,
3423 boolean isSuperCall) {
3424 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall);
3425 if (sym == null) {
3426 log.error(pos, "encl.class.required", member);
3427 return syms.errSymbol;
3428 } else {
3429 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true);
3430 }
3431 }
3433 boolean hasEnclosingInstance(Env<AttrContext> env, Type type) {
3434 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false);
3435 return encl != null && encl.kind < ERRONEOUS;
3436 }
3438 private Symbol resolveSelfContainingInternal(Env<AttrContext> env,
3439 Symbol member,
3440 boolean isSuperCall) {
3441 Name name = names._this;
3442 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
3443 boolean staticOnly = false;
3444 if (env1 != null) {
3445 while (env1 != null && env1.outer != null) {
3446 if (isStatic(env1)) staticOnly = true;
3447 if (env1.enclClass.sym.isSubClass(member.owner, types)) {
3448 Symbol sym = env1.info.scope.lookup(name).sym;
3449 if (sym != null) {
3450 if (staticOnly) sym = new StaticError(sym);
3451 return sym;
3452 }
3453 }
3454 if ((env1.enclClass.sym.flags() & STATIC) != 0)
3455 staticOnly = true;
3456 env1 = env1.outer;
3457 }
3458 }
3459 return null;
3460 }
3462 /**
3463 * Resolve an appropriate implicit this instance for t's container.
3464 * JLS 8.8.5.1 and 15.9.2
3465 */
3466 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
3467 return resolveImplicitThis(pos, env, t, false);
3468 }
3470 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
3471 Type thisType = (((t.tsym.owner.kind & (MTH|VAR)) != 0)
3472 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
3473 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
3474 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym)
3475 log.error(pos, "cant.ref.before.ctor.called", "this");
3476 return thisType;
3477 }
3479 /* ***************************************************************************
3480 * ResolveError classes, indicating error situations when accessing symbols
3481 ****************************************************************************/
3483 //used by TransTypes when checking target type of synthetic cast
3484 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) {
3485 AccessError error = new AccessError(env, env.enclClass.type, type.tsym);
3486 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null);
3487 }
3488 //where
3489 private void logResolveError(ResolveError error,
3490 DiagnosticPosition pos,
3491 Symbol location,
3492 Type site,
3493 Name name,
3494 List<Type> argtypes,
3495 List<Type> typeargtypes) {
3496 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
3497 pos, location, site, name, argtypes, typeargtypes);
3498 if (d != null) {
3499 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
3500 log.report(d);
3501 }
3502 }
3504 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
3506 public Object methodArguments(List<Type> argtypes) {
3507 if (argtypes == null || argtypes.isEmpty()) {
3508 return noArgs;
3509 } else {
3510 ListBuffer<Object> diagArgs = new ListBuffer<>();
3511 for (Type t : argtypes) {
3512 if (t.hasTag(DEFERRED)) {
3513 diagArgs.append(((DeferredAttr.DeferredType)t).tree);
3514 } else {
3515 diagArgs.append(t);
3516 }
3517 }
3518 return diagArgs;
3519 }
3520 }
3522 /**
3523 * Root class for resolution errors. Subclass of ResolveError
3524 * represent a different kinds of resolution error - as such they must
3525 * specify how they map into concrete compiler diagnostics.
3526 */
3527 abstract class ResolveError extends Symbol {
3529 /** The name of the kind of error, for debugging only. */
3530 final String debugName;
3532 ResolveError(int kind, String debugName) {
3533 super(kind, 0, null, null, null);
3534 this.debugName = debugName;
3535 }
3537 @Override
3538 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
3539 throw new AssertionError();
3540 }
3542 @Override
3543 public String toString() {
3544 return debugName;
3545 }
3547 @Override
3548 public boolean exists() {
3549 return false;
3550 }
3552 @Override
3553 public boolean isStatic() {
3554 return false;
3555 }
3557 /**
3558 * Create an external representation for this erroneous symbol to be
3559 * used during attribution - by default this returns the symbol of a
3560 * brand new error type which stores the original type found
3561 * during resolution.
3562 *
3563 * @param name the name used during resolution
3564 * @param location the location from which the symbol is accessed
3565 */
3566 protected Symbol access(Name name, TypeSymbol location) {
3567 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3568 }
3570 /**
3571 * Create a diagnostic representing this resolution error.
3572 *
3573 * @param dkind The kind of the diagnostic to be created (e.g error).
3574 * @param pos The position to be used for error reporting.
3575 * @param site The original type from where the selection took place.
3576 * @param name The name of the symbol to be resolved.
3577 * @param argtypes The invocation's value arguments,
3578 * if we looked for a method.
3579 * @param typeargtypes The invocation's type arguments,
3580 * if we looked for a method.
3581 */
3582 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3583 DiagnosticPosition pos,
3584 Symbol location,
3585 Type site,
3586 Name name,
3587 List<Type> argtypes,
3588 List<Type> typeargtypes);
3589 }
3591 /**
3592 * This class is the root class of all resolution errors caused by
3593 * an invalid symbol being found during resolution.
3594 */
3595 abstract class InvalidSymbolError extends ResolveError {
3597 /** The invalid symbol found during resolution */
3598 Symbol sym;
3600 InvalidSymbolError(int kind, Symbol sym, String debugName) {
3601 super(kind, debugName);
3602 this.sym = sym;
3603 }
3605 @Override
3606 public boolean exists() {
3607 return true;
3608 }
3610 @Override
3611 public String toString() {
3612 return super.toString() + " wrongSym=" + sym;
3613 }
3615 @Override
3616 public Symbol access(Name name, TypeSymbol location) {
3617 if ((sym.kind & ERRONEOUS) == 0 && (sym.kind & TYP) != 0)
3618 return types.createErrorType(name, location, sym.type).tsym;
3619 else
3620 return sym;
3621 }
3622 }
3624 /**
3625 * InvalidSymbolError error class indicating that a symbol matching a
3626 * given name does not exists in a given site.
3627 */
3628 class SymbolNotFoundError extends ResolveError {
3630 SymbolNotFoundError(int kind) {
3631 this(kind, "symbol not found error");
3632 }
3634 SymbolNotFoundError(int kind, String debugName) {
3635 super(kind, debugName);
3636 }
3638 @Override
3639 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3640 DiagnosticPosition pos,
3641 Symbol location,
3642 Type site,
3643 Name name,
3644 List<Type> argtypes,
3645 List<Type> typeargtypes) {
3646 argtypes = argtypes == null ? List.<Type>nil() : argtypes;
3647 typeargtypes = typeargtypes == null ? List.<Type>nil() : typeargtypes;
3648 if (name == names.error)
3649 return null;
3651 if (syms.operatorNames.contains(name)) {
3652 boolean isUnaryOp = argtypes.size() == 1;
3653 String key = argtypes.size() == 1 ?
3654 "operator.cant.be.applied" :
3655 "operator.cant.be.applied.1";
3656 Type first = argtypes.head;
3657 Type second = !isUnaryOp ? argtypes.tail.head : null;
3658 return diags.create(dkind, log.currentSource(), pos,
3659 key, name, first, second);
3660 }
3661 boolean hasLocation = false;
3662 if (location == null) {
3663 location = site.tsym;
3664 }
3665 if (!location.name.isEmpty()) {
3666 if (location.kind == PCK && !site.tsym.exists()) {
3667 return diags.create(dkind, log.currentSource(), pos,
3668 "doesnt.exist", location);
3669 }
3670 hasLocation = !location.name.equals(names._this) &&
3671 !location.name.equals(names._super);
3672 }
3673 boolean isConstructor = (kind == ABSENT_MTH || kind == WRONG_STATICNESS) &&
3674 name == names.init;
3675 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : absentKind(kind);
3676 Name idname = isConstructor ? site.tsym.name : name;
3677 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
3678 if (hasLocation) {
3679 return diags.create(dkind, log.currentSource(), pos,
3680 errKey, kindname, idname, //symbol kindname, name
3681 typeargtypes, args(argtypes), //type parameters and arguments (if any)
3682 getLocationDiag(location, site)); //location kindname, type
3683 }
3684 else {
3685 return diags.create(dkind, log.currentSource(), pos,
3686 errKey, kindname, idname, //symbol kindname, name
3687 typeargtypes, args(argtypes)); //type parameters and arguments (if any)
3688 }
3689 }
3690 //where
3691 private Object args(List<Type> args) {
3692 return args.isEmpty() ? args : methodArguments(args);
3693 }
3695 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
3696 String key = "cant.resolve";
3697 String suffix = hasLocation ? ".location" : "";
3698 switch (kindname) {
3699 case METHOD:
3700 case CONSTRUCTOR: {
3701 suffix += ".args";
3702 suffix += hasTypeArgs ? ".params" : "";
3703 }
3704 }
3705 return key + suffix;
3706 }
3707 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
3708 if (location.kind == VAR) {
3709 return diags.fragment("location.1",
3710 kindName(location),
3711 location,
3712 location.type);
3713 } else {
3714 return diags.fragment("location",
3715 typeKindName(site),
3716 site,
3717 null);
3718 }
3719 }
3720 }
3722 /**
3723 * InvalidSymbolError error class indicating that a given symbol
3724 * (either a method, a constructor or an operand) is not applicable
3725 * given an actual arguments/type argument list.
3726 */
3727 class InapplicableSymbolError extends ResolveError {
3729 protected MethodResolutionContext resolveContext;
3731 InapplicableSymbolError(MethodResolutionContext context) {
3732 this(WRONG_MTH, "inapplicable symbol error", context);
3733 }
3735 protected InapplicableSymbolError(int kind, String debugName, MethodResolutionContext context) {
3736 super(kind, debugName);
3737 this.resolveContext = context;
3738 }
3740 @Override
3741 public String toString() {
3742 return super.toString();
3743 }
3745 @Override
3746 public boolean exists() {
3747 return true;
3748 }
3750 @Override
3751 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3752 DiagnosticPosition pos,
3753 Symbol location,
3754 Type site,
3755 Name name,
3756 List<Type> argtypes,
3757 List<Type> typeargtypes) {
3758 if (name == names.error)
3759 return null;
3761 if (syms.operatorNames.contains(name)) {
3762 boolean isUnaryOp = argtypes.size() == 1;
3763 String key = argtypes.size() == 1 ?
3764 "operator.cant.be.applied" :
3765 "operator.cant.be.applied.1";
3766 Type first = argtypes.head;
3767 Type second = !isUnaryOp ? argtypes.tail.head : null;
3768 return diags.create(dkind, log.currentSource(), pos,
3769 key, name, first, second);
3770 }
3771 else {
3772 Pair<Symbol, JCDiagnostic> c = errCandidate();
3773 if (compactMethodDiags) {
3774 for (Map.Entry<Template, DiagnosticRewriter> _entry :
3775 MethodResolutionDiagHelper.rewriters.entrySet()) {
3776 if (_entry.getKey().matches(c.snd)) {
3777 JCDiagnostic simpleDiag =
3778 _entry.getValue().rewriteDiagnostic(diags, pos,
3779 log.currentSource(), dkind, c.snd);
3780 simpleDiag.setFlag(DiagnosticFlag.COMPRESSED);
3781 return simpleDiag;
3782 }
3783 }
3784 }
3785 Symbol ws = c.fst.asMemberOf(site, types);
3786 return diags.create(dkind, log.currentSource(), pos,
3787 "cant.apply.symbol",
3788 kindName(ws),
3789 ws.name == names.init ? ws.owner.name : ws.name,
3790 methodArguments(ws.type.getParameterTypes()),
3791 methodArguments(argtypes),
3792 kindName(ws.owner),
3793 ws.owner.type,
3794 c.snd);
3795 }
3796 }
3798 @Override
3799 public Symbol access(Name name, TypeSymbol location) {
3800 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3801 }
3803 protected Pair<Symbol, JCDiagnostic> errCandidate() {
3804 Candidate bestSoFar = null;
3805 for (Candidate c : resolveContext.candidates) {
3806 if (c.isApplicable()) continue;
3807 bestSoFar = c;
3808 }
3809 Assert.checkNonNull(bestSoFar);
3810 return new Pair<Symbol, JCDiagnostic>(bestSoFar.sym, bestSoFar.details);
3811 }
3812 }
3814 /**
3815 * ResolveError error class indicating that a set of symbols
3816 * (either methods, constructors or operands) is not applicable
3817 * given an actual arguments/type argument list.
3818 */
3819 class InapplicableSymbolsError extends InapplicableSymbolError {
3821 InapplicableSymbolsError(MethodResolutionContext context) {
3822 super(WRONG_MTHS, "inapplicable symbols", context);
3823 }
3825 @Override
3826 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3827 DiagnosticPosition pos,
3828 Symbol location,
3829 Type site,
3830 Name name,
3831 List<Type> argtypes,
3832 List<Type> typeargtypes) {
3833 Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates();
3834 Map<Symbol, JCDiagnostic> filteredCandidates = compactMethodDiags ?
3835 filterCandidates(candidatesMap) :
3836 mapCandidates();
3837 if (filteredCandidates.isEmpty()) {
3838 filteredCandidates = candidatesMap;
3839 }
3840 boolean truncatedDiag = candidatesMap.size() != filteredCandidates.size();
3841 if (filteredCandidates.size() > 1) {
3842 JCDiagnostic err = diags.create(dkind,
3843 null,
3844 truncatedDiag ?
3845 EnumSet.of(DiagnosticFlag.COMPRESSED) :
3846 EnumSet.noneOf(DiagnosticFlag.class),
3847 log.currentSource(),
3848 pos,
3849 "cant.apply.symbols",
3850 name == names.init ? KindName.CONSTRUCTOR : absentKind(kind),
3851 name == names.init ? site.tsym.name : name,
3852 methodArguments(argtypes));
3853 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(filteredCandidates, site));
3854 } else if (filteredCandidates.size() == 1) {
3855 Map.Entry<Symbol, JCDiagnostic> _e =
3856 filteredCandidates.entrySet().iterator().next();
3857 final Pair<Symbol, JCDiagnostic> p = new Pair<Symbol, JCDiagnostic>(_e.getKey(), _e.getValue());
3858 JCDiagnostic d = new InapplicableSymbolError(resolveContext) {
3859 @Override
3860 protected Pair<Symbol, JCDiagnostic> errCandidate() {
3861 return p;
3862 }
3863 }.getDiagnostic(dkind, pos,
3864 location, site, name, argtypes, typeargtypes);
3865 if (truncatedDiag) {
3866 d.setFlag(DiagnosticFlag.COMPRESSED);
3867 }
3868 return d;
3869 } else {
3870 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
3871 location, site, name, argtypes, typeargtypes);
3872 }
3873 }
3874 //where
3875 private Map<Symbol, JCDiagnostic> mapCandidates() {
3876 Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<Symbol, JCDiagnostic>();
3877 for (Candidate c : resolveContext.candidates) {
3878 if (c.isApplicable()) continue;
3879 candidates.put(c.sym, c.details);
3880 }
3881 return candidates;
3882 }
3884 Map<Symbol, JCDiagnostic> filterCandidates(Map<Symbol, JCDiagnostic> candidatesMap) {
3885 Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<Symbol, JCDiagnostic>();
3886 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
3887 JCDiagnostic d = _entry.getValue();
3888 if (!new Template(MethodCheckDiag.ARITY_MISMATCH.regex()).matches(d)) {
3889 candidates.put(_entry.getKey(), d);
3890 }
3891 }
3892 return candidates;
3893 }
3895 private List<JCDiagnostic> candidateDetails(Map<Symbol, JCDiagnostic> candidatesMap, Type site) {
3896 List<JCDiagnostic> details = List.nil();
3897 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
3898 Symbol sym = _entry.getKey();
3899 JCDiagnostic detailDiag = diags.fragment("inapplicable.method",
3900 Kinds.kindName(sym),
3901 sym.location(site, types),
3902 sym.asMemberOf(site, types),
3903 _entry.getValue());
3904 details = details.prepend(detailDiag);
3905 }
3906 //typically members are visited in reverse order (see Scope)
3907 //so we need to reverse the candidate list so that candidates
3908 //conform to source order
3909 return details;
3910 }
3911 }
3913 /**
3914 * An InvalidSymbolError error class indicating that a symbol is not
3915 * accessible from a given site
3916 */
3917 class AccessError extends InvalidSymbolError {
3919 private Env<AttrContext> env;
3920 private Type site;
3922 AccessError(Symbol sym) {
3923 this(null, null, sym);
3924 }
3926 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
3927 super(HIDDEN, sym, "access error");
3928 this.env = env;
3929 this.site = site;
3930 if (debugResolve)
3931 log.error("proc.messager", sym + " @ " + site + " is inaccessible.");
3932 }
3934 @Override
3935 public boolean exists() {
3936 return false;
3937 }
3939 @Override
3940 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3941 DiagnosticPosition pos,
3942 Symbol location,
3943 Type site,
3944 Name name,
3945 List<Type> argtypes,
3946 List<Type> typeargtypes) {
3947 if (sym.owner.type.hasTag(ERROR))
3948 return null;
3950 if (sym.name == names.init && sym.owner != site.tsym) {
3951 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
3952 pos, location, site, name, argtypes, typeargtypes);
3953 }
3954 else if ((sym.flags() & PUBLIC) != 0
3955 || (env != null && this.site != null
3956 && !isAccessible(env, this.site))) {
3957 return diags.create(dkind, log.currentSource(),
3958 pos, "not.def.access.class.intf.cant.access",
3959 sym, sym.location());
3960 }
3961 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
3962 return diags.create(dkind, log.currentSource(),
3963 pos, "report.access", sym,
3964 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
3965 sym.location());
3966 }
3967 else {
3968 return diags.create(dkind, log.currentSource(),
3969 pos, "not.def.public.cant.access", sym, sym.location());
3970 }
3971 }
3972 }
3974 /**
3975 * InvalidSymbolError error class indicating that an instance member
3976 * has erroneously been accessed from a static context.
3977 */
3978 class StaticError extends InvalidSymbolError {
3980 StaticError(Symbol sym) {
3981 super(STATICERR, sym, "static error");
3982 }
3984 @Override
3985 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3986 DiagnosticPosition pos,
3987 Symbol location,
3988 Type site,
3989 Name name,
3990 List<Type> argtypes,
3991 List<Type> typeargtypes) {
3992 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS))
3993 ? types.erasure(sym.type).tsym
3994 : sym);
3995 return diags.create(dkind, log.currentSource(), pos,
3996 "non-static.cant.be.ref", kindName(sym), errSym);
3997 }
3998 }
4000 /**
4001 * InvalidSymbolError error class indicating that a pair of symbols
4002 * (either methods, constructors or operands) are ambiguous
4003 * given an actual arguments/type argument list.
4004 */
4005 class AmbiguityError extends ResolveError {
4007 /** The other maximally specific symbol */
4008 List<Symbol> ambiguousSyms = List.nil();
4010 @Override
4011 public boolean exists() {
4012 return true;
4013 }
4015 AmbiguityError(Symbol sym1, Symbol sym2) {
4016 super(AMBIGUOUS, "ambiguity error");
4017 ambiguousSyms = flatten(sym2).appendList(flatten(sym1));
4018 }
4020 private List<Symbol> flatten(Symbol sym) {
4021 if (sym.kind == AMBIGUOUS) {
4022 return ((AmbiguityError)sym.baseSymbol()).ambiguousSyms;
4023 } else {
4024 return List.of(sym);
4025 }
4026 }
4028 AmbiguityError addAmbiguousSymbol(Symbol s) {
4029 ambiguousSyms = ambiguousSyms.prepend(s);
4030 return this;
4031 }
4033 @Override
4034 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
4035 DiagnosticPosition pos,
4036 Symbol location,
4037 Type site,
4038 Name name,
4039 List<Type> argtypes,
4040 List<Type> typeargtypes) {
4041 List<Symbol> diagSyms = ambiguousSyms.reverse();
4042 Symbol s1 = diagSyms.head;
4043 Symbol s2 = diagSyms.tail.head;
4044 Name sname = s1.name;
4045 if (sname == names.init) sname = s1.owner.name;
4046 return diags.create(dkind, log.currentSource(),
4047 pos, "ref.ambiguous", sname,
4048 kindName(s1),
4049 s1,
4050 s1.location(site, types),
4051 kindName(s2),
4052 s2,
4053 s2.location(site, types));
4054 }
4056 /**
4057 * If multiple applicable methods are found during overload and none of them
4058 * is more specific than the others, attempt to merge their signatures.
4059 */
4060 Symbol mergeAbstracts(Type site) {
4061 List<Symbol> ambiguousInOrder = ambiguousSyms.reverse();
4062 for (Symbol s : ambiguousInOrder) {
4063 Type mt = types.memberType(site, s);
4064 boolean found = true;
4065 List<Type> allThrown = mt.getThrownTypes();
4066 for (Symbol s2 : ambiguousInOrder) {
4067 Type mt2 = types.memberType(site, s2);
4068 if ((s2.flags() & ABSTRACT) == 0 ||
4069 !types.overrideEquivalent(mt, mt2) ||
4070 !types.isSameTypes(s.erasure(types).getParameterTypes(),
4071 s2.erasure(types).getParameterTypes())) {
4072 //ambiguity cannot be resolved
4073 return this;
4074 }
4075 Type mst = mostSpecificReturnType(mt, mt2);
4076 if (mst == null || mst != mt) {
4077 found = false;
4078 break;
4079 }
4080 allThrown = chk.intersect(allThrown, mt2.getThrownTypes());
4081 }
4082 if (found) {
4083 //all ambiguous methods were abstract and one method had
4084 //most specific return type then others
4085 return (allThrown == mt.getThrownTypes()) ?
4086 s : new MethodSymbol(
4087 s.flags(),
4088 s.name,
4089 types.createMethodTypeWithThrown(mt, allThrown),
4090 s.owner);
4091 }
4092 }
4093 return this;
4094 }
4096 @Override
4097 protected Symbol access(Name name, TypeSymbol location) {
4098 Symbol firstAmbiguity = ambiguousSyms.last();
4099 return firstAmbiguity.kind == TYP ?
4100 types.createErrorType(name, location, firstAmbiguity.type).tsym :
4101 firstAmbiguity;
4102 }
4103 }
4105 class BadVarargsMethod extends ResolveError {
4107 ResolveError delegatedError;
4109 BadVarargsMethod(ResolveError delegatedError) {
4110 super(delegatedError.kind, "badVarargs");
4111 this.delegatedError = delegatedError;
4112 }
4114 @Override
4115 public Symbol baseSymbol() {
4116 return delegatedError.baseSymbol();
4117 }
4119 @Override
4120 protected Symbol access(Name name, TypeSymbol location) {
4121 return delegatedError.access(name, location);
4122 }
4124 @Override
4125 public boolean exists() {
4126 return true;
4127 }
4129 @Override
4130 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
4131 return delegatedError.getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes);
4132 }
4133 }
4135 /**
4136 * Helper class for method resolution diagnostic simplification.
4137 * Certain resolution diagnostic are rewritten as simpler diagnostic
4138 * where the enclosing resolution diagnostic (i.e. 'inapplicable method')
4139 * is stripped away, as it doesn't carry additional info. The logic
4140 * for matching a given diagnostic is given in terms of a template
4141 * hierarchy: a diagnostic template can be specified programmatically,
4142 * so that only certain diagnostics are matched. Each templete is then
4143 * associated with a rewriter object that carries out the task of rewtiting
4144 * the diagnostic to a simpler one.
4145 */
4146 static class MethodResolutionDiagHelper {
4148 /**
4149 * A diagnostic rewriter transforms a method resolution diagnostic
4150 * into a simpler one
4151 */
4152 interface DiagnosticRewriter {
4153 JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
4154 DiagnosticPosition preferedPos, DiagnosticSource preferredSource,
4155 DiagnosticType preferredKind, JCDiagnostic d);
4156 }
4158 /**
4159 * A diagnostic template is made up of two ingredients: (i) a regular
4160 * expression for matching a diagnostic key and (ii) a list of sub-templates
4161 * for matching diagnostic arguments.
4162 */
4163 static class Template {
4165 /** regex used to match diag key */
4166 String regex;
4168 /** templates used to match diagnostic args */
4169 Template[] subTemplates;
4171 Template(String key, Template... subTemplates) {
4172 this.regex = key;
4173 this.subTemplates = subTemplates;
4174 }
4176 /**
4177 * Returns true if the regex matches the diagnostic key and if
4178 * all diagnostic arguments are matches by corresponding sub-templates.
4179 */
4180 boolean matches(Object o) {
4181 JCDiagnostic d = (JCDiagnostic)o;
4182 Object[] args = d.getArgs();
4183 if (!d.getCode().matches(regex) ||
4184 subTemplates.length != d.getArgs().length) {
4185 return false;
4186 }
4187 for (int i = 0; i < args.length ; i++) {
4188 if (!subTemplates[i].matches(args[i])) {
4189 return false;
4190 }
4191 }
4192 return true;
4193 }
4194 }
4196 /** a dummy template that match any diagnostic argument */
4197 static final Template skip = new Template("") {
4198 @Override
4199 boolean matches(Object d) {
4200 return true;
4201 }
4202 };
4204 /** rewriter map used for method resolution simplification */
4205 static final Map<Template, DiagnosticRewriter> rewriters =
4206 new LinkedHashMap<Template, DiagnosticRewriter>();
4208 static {
4209 String argMismatchRegex = MethodCheckDiag.ARG_MISMATCH.regex();
4210 rewriters.put(new Template(argMismatchRegex, skip),
4211 new DiagnosticRewriter() {
4212 @Override
4213 public JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
4214 DiagnosticPosition preferedPos, DiagnosticSource preferredSource,
4215 DiagnosticType preferredKind, JCDiagnostic d) {
4216 JCDiagnostic cause = (JCDiagnostic)d.getArgs()[0];
4217 return diags.create(preferredKind, preferredSource, d.getDiagnosticPosition(),
4218 "prob.found.req", cause);
4219 }
4220 });
4221 }
4222 }
4224 enum MethodResolutionPhase {
4225 BASIC(false, false),
4226 BOX(true, false),
4227 VARARITY(true, true) {
4228 @Override
4229 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) {
4230 //Check invariants (see {@code LookupHelper.shouldStop})
4231 Assert.check(bestSoFar.kind >= ERRONEOUS && bestSoFar.kind != AMBIGUOUS);
4232 if (sym.kind < ERRONEOUS) {
4233 //varargs resolution successful
4234 return sym;
4235 } else {
4236 //pick best error
4237 switch (bestSoFar.kind) {
4238 case WRONG_MTH:
4239 case WRONG_MTHS:
4240 //Override previous errors if they were caused by argument mismatch.
4241 //This generally means preferring current symbols - but we need to pay
4242 //attention to the fact that the varargs lookup returns 'less' candidates
4243 //than the previous rounds, and adjust that accordingly.
4244 switch (sym.kind) {
4245 case WRONG_MTH:
4246 //if the previous round matched more than one method, return that
4247 //result instead
4248 return bestSoFar.kind == WRONG_MTHS ?
4249 bestSoFar : sym;
4250 case ABSENT_MTH:
4251 //do not override erroneous symbol if the arity lookup did not
4252 //match any method
4253 return bestSoFar;
4254 case WRONG_MTHS:
4255 default:
4256 //safe to override
4257 return sym;
4258 }
4259 default:
4260 //otherwise, return first error
4261 return bestSoFar;
4262 }
4263 }
4264 }
4265 };
4267 final boolean isBoxingRequired;
4268 final boolean isVarargsRequired;
4270 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
4271 this.isBoxingRequired = isBoxingRequired;
4272 this.isVarargsRequired = isVarargsRequired;
4273 }
4275 public boolean isBoxingRequired() {
4276 return isBoxingRequired;
4277 }
4279 public boolean isVarargsRequired() {
4280 return isVarargsRequired;
4281 }
4283 public boolean isApplicable(boolean boxingEnabled, boolean varargsEnabled) {
4284 return (varargsEnabled || !isVarargsRequired) &&
4285 (boxingEnabled || !isBoxingRequired);
4286 }
4288 public Symbol mergeResults(Symbol prev, Symbol sym) {
4289 return sym;
4290 }
4291 }
4293 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
4295 /**
4296 * A resolution context is used to keep track of intermediate results of
4297 * overload resolution, such as list of method that are not applicable
4298 * (used to generate more precise diagnostics) and so on. Resolution contexts
4299 * can be nested - this means that when each overload resolution routine should
4300 * work within the resolution context it created.
4301 */
4302 class MethodResolutionContext {
4304 private List<Candidate> candidates = List.nil();
4306 MethodResolutionPhase step = null;
4308 MethodCheck methodCheck = resolveMethodCheck;
4310 private boolean internalResolution = false;
4311 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE;
4313 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) {
4314 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null);
4315 candidates = candidates.append(c);
4316 }
4318 void addApplicableCandidate(Symbol sym, Type mtype) {
4319 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype);
4320 candidates = candidates.append(c);
4321 }
4323 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext, ResultInfo pendingResult, Warner warn) {
4324 DeferredAttrContext parent = (pendingResult == null)
4325 ? deferredAttr.emptyDeferredAttrContext
4326 : pendingResult.checkContext.deferredAttrContext();
4327 return deferredAttr.new DeferredAttrContext(attrMode, sym, step,
4328 inferenceContext, parent, warn);
4329 }
4331 /**
4332 * This class represents an overload resolution candidate. There are two
4333 * kinds of candidates: applicable methods and inapplicable methods;
4334 * applicable methods have a pointer to the instantiated method type,
4335 * while inapplicable candidates contain further details about the
4336 * reason why the method has been considered inapplicable.
4337 */
4338 @SuppressWarnings("overrides")
4339 class Candidate {
4341 final MethodResolutionPhase step;
4342 final Symbol sym;
4343 final JCDiagnostic details;
4344 final Type mtype;
4346 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) {
4347 this.step = step;
4348 this.sym = sym;
4349 this.details = details;
4350 this.mtype = mtype;
4351 }
4353 @Override
4354 public boolean equals(Object o) {
4355 if (o instanceof Candidate) {
4356 Symbol s1 = this.sym;
4357 Symbol s2 = ((Candidate)o).sym;
4358 if ((s1 != s2 &&
4359 (s1.overrides(s2, s1.owner.type.tsym, types, false) ||
4360 (s2.overrides(s1, s2.owner.type.tsym, types, false)))) ||
4361 ((s1.isConstructor() || s2.isConstructor()) && s1.owner != s2.owner))
4362 return true;
4363 }
4364 return false;
4365 }
4367 boolean isApplicable() {
4368 return mtype != null;
4369 }
4370 }
4372 DeferredAttr.AttrMode attrMode() {
4373 return attrMode;
4374 }
4376 boolean internal() {
4377 return internalResolution;
4378 }
4379 }
4381 MethodResolutionContext currentResolutionContext = null;
4382 }