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src/share/classes/com/sun/tools/javac/comp/Resolve.java@3806171b52d8
src/share/classes/com/sun/tools/javac/comp/Resolve.java
Thu, 07 Mar 2013 10:04:28 +0000
- author
- vromero
- date
- Thu, 07 Mar 2013 10:04:28 +0000
- changeset 1620
- 3806171b52d8
- parent 1610
- 08782b8b03ce
- child 1674
- b71a61d39cf7
- permissions
- -rw-r--r--
8009138: javac, equals-hashCode warning tuning
Reviewed-by: mcimadamore
1 /*
2 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
26 package com.sun.tools.javac.comp;
28 import com.sun.tools.javac.api.Formattable.LocalizedString;
29 import com.sun.tools.javac.code.*;
30 import com.sun.tools.javac.code.Symbol.*;
31 import com.sun.tools.javac.code.Type.*;
32 import com.sun.tools.javac.comp.Attr.ResultInfo;
33 import com.sun.tools.javac.comp.Check.CheckContext;
34 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
35 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
36 import com.sun.tools.javac.comp.DeferredAttr.DeferredType;
37 import com.sun.tools.javac.comp.Infer.InferenceContext;
38 import com.sun.tools.javac.comp.Infer.FreeTypeListener;
39 import com.sun.tools.javac.comp.Resolve.MethodResolutionContext.Candidate;
40 import com.sun.tools.javac.jvm.*;
41 import com.sun.tools.javac.tree.*;
42 import com.sun.tools.javac.tree.JCTree.*;
43 import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind;
44 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
45 import com.sun.tools.javac.util.*;
46 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
47 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
48 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
50 import java.util.Arrays;
51 import java.util.Collection;
52 import java.util.EnumMap;
53 import java.util.EnumSet;
54 import java.util.Iterator;
55 import java.util.LinkedHashMap;
56 import java.util.LinkedHashSet;
57 import java.util.Map;
59 import javax.lang.model.element.ElementVisitor;
61 import static com.sun.tools.javac.code.Flags.*;
62 import static com.sun.tools.javac.code.Flags.BLOCK;
63 import static com.sun.tools.javac.code.Kinds.*;
64 import static com.sun.tools.javac.code.Kinds.ERRONEOUS;
65 import static com.sun.tools.javac.code.TypeTag.*;
66 import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*;
67 import static com.sun.tools.javac.tree.JCTree.Tag.*;
69 /** Helper class for name resolution, used mostly by the attribution phase.
70 *
71 * <p><b>This is NOT part of any supported API.
72 * If you write code that depends on this, you do so at your own risk.
73 * This code and its internal interfaces are subject to change or
74 * deletion without notice.</b>
75 */
76 public class Resolve {
77 protected static final Context.Key<Resolve> resolveKey =
78 new Context.Key<Resolve>();
80 Names names;
81 Log log;
82 Symtab syms;
83 Attr attr;
84 DeferredAttr deferredAttr;
85 Check chk;
86 Infer infer;
87 ClassReader reader;
88 TreeInfo treeinfo;
89 Types types;
90 JCDiagnostic.Factory diags;
91 public final boolean boxingEnabled; // = source.allowBoxing();
92 public final boolean varargsEnabled; // = source.allowVarargs();
93 public final boolean allowMethodHandles;
94 public final boolean allowDefaultMethods;
95 public final boolean allowStructuralMostSpecific;
96 private final boolean debugResolve;
97 final EnumSet<VerboseResolutionMode> verboseResolutionMode;
99 Scope polymorphicSignatureScope;
101 protected Resolve(Context context) {
102 context.put(resolveKey, this);
103 syms = Symtab.instance(context);
105 varNotFound = new
106 SymbolNotFoundError(ABSENT_VAR);
107 methodNotFound = new
108 SymbolNotFoundError(ABSENT_MTH);
109 typeNotFound = new
110 SymbolNotFoundError(ABSENT_TYP);
112 names = Names.instance(context);
113 log = Log.instance(context);
114 attr = Attr.instance(context);
115 deferredAttr = DeferredAttr.instance(context);
116 chk = Check.instance(context);
117 infer = Infer.instance(context);
118 reader = ClassReader.instance(context);
119 treeinfo = TreeInfo.instance(context);
120 types = Types.instance(context);
121 diags = JCDiagnostic.Factory.instance(context);
122 Source source = Source.instance(context);
123 boxingEnabled = source.allowBoxing();
124 varargsEnabled = source.allowVarargs();
125 Options options = Options.instance(context);
126 debugResolve = options.isSet("debugresolve");
127 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
128 Target target = Target.instance(context);
129 allowMethodHandles = target.hasMethodHandles();
130 allowDefaultMethods = source.allowDefaultMethods();
131 allowStructuralMostSpecific = source.allowStructuralMostSpecific();
132 polymorphicSignatureScope = new Scope(syms.noSymbol);
134 inapplicableMethodException = new InapplicableMethodException(diags);
135 }
137 /** error symbols, which are returned when resolution fails
138 */
139 private final SymbolNotFoundError varNotFound;
140 private final SymbolNotFoundError methodNotFound;
141 private final SymbolNotFoundError typeNotFound;
143 public static Resolve instance(Context context) {
144 Resolve instance = context.get(resolveKey);
145 if (instance == null)
146 instance = new Resolve(context);
147 return instance;
148 }
150 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support">
151 enum VerboseResolutionMode {
152 SUCCESS("success"),
153 FAILURE("failure"),
154 APPLICABLE("applicable"),
155 INAPPLICABLE("inapplicable"),
156 DEFERRED_INST("deferred-inference"),
157 PREDEF("predef"),
158 OBJECT_INIT("object-init"),
159 INTERNAL("internal");
161 final String opt;
163 private VerboseResolutionMode(String opt) {
164 this.opt = opt;
165 }
167 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) {
168 String s = opts.get("verboseResolution");
169 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class);
170 if (s == null) return res;
171 if (s.contains("all")) {
172 res = EnumSet.allOf(VerboseResolutionMode.class);
173 }
174 Collection<String> args = Arrays.asList(s.split(","));
175 for (VerboseResolutionMode mode : values()) {
176 if (args.contains(mode.opt)) {
177 res.add(mode);
178 } else if (args.contains("-" + mode.opt)) {
179 res.remove(mode);
180 }
181 }
182 return res;
183 }
184 }
186 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site,
187 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) {
188 boolean success = bestSoFar.kind < ERRONEOUS;
190 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) {
191 return;
192 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) {
193 return;
194 }
196 if (bestSoFar.name == names.init &&
197 bestSoFar.owner == syms.objectType.tsym &&
198 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) {
199 return; //skip diags for Object constructor resolution
200 } else if (site == syms.predefClass.type &&
201 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) {
202 return; //skip spurious diags for predef symbols (i.e. operators)
203 } else if (currentResolutionContext.internalResolution &&
204 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) {
205 return;
206 }
208 int pos = 0;
209 int mostSpecificPos = -1;
210 ListBuffer<JCDiagnostic> subDiags = ListBuffer.lb();
211 for (Candidate c : currentResolutionContext.candidates) {
212 if (currentResolutionContext.step != c.step ||
213 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) ||
214 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) {
215 continue;
216 } else {
217 subDiags.append(c.isApplicable() ?
218 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) :
219 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details));
220 if (c.sym == bestSoFar)
221 mostSpecificPos = pos;
222 pos++;
223 }
224 }
225 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1";
226 List<Type> argtypes2 = Type.map(argtypes,
227 deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step));
228 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name,
229 site.tsym, mostSpecificPos, currentResolutionContext.step,
230 methodArguments(argtypes2),
231 methodArguments(typeargtypes));
232 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
233 log.report(d);
234 }
236 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) {
237 JCDiagnostic subDiag = null;
238 if (sym.type.hasTag(FORALL)) {
239 subDiag = diags.fragment("partial.inst.sig", inst);
240 }
242 String key = subDiag == null ?
243 "applicable.method.found" :
244 "applicable.method.found.1";
246 return diags.fragment(key, pos, sym, subDiag);
247 }
249 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) {
250 return diags.fragment("not.applicable.method.found", pos, sym, subDiag);
251 }
252 // </editor-fold>
254 /* ************************************************************************
255 * Identifier resolution
256 *************************************************************************/
258 /** An environment is "static" if its static level is greater than
259 * the one of its outer environment
260 */
261 protected static boolean isStatic(Env<AttrContext> env) {
262 return env.info.staticLevel > env.outer.info.staticLevel;
263 }
265 /** An environment is an "initializer" if it is a constructor or
266 * an instance initializer.
267 */
268 static boolean isInitializer(Env<AttrContext> env) {
269 Symbol owner = env.info.scope.owner;
270 return owner.isConstructor() ||
271 owner.owner.kind == TYP &&
272 (owner.kind == VAR ||
273 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
274 (owner.flags() & STATIC) == 0;
275 }
277 /** Is class accessible in given evironment?
278 * @param env The current environment.
279 * @param c The class whose accessibility is checked.
280 */
281 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
282 return isAccessible(env, c, false);
283 }
285 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) {
286 boolean isAccessible = false;
287 switch ((short)(c.flags() & AccessFlags)) {
288 case PRIVATE:
289 isAccessible =
290 env.enclClass.sym.outermostClass() ==
291 c.owner.outermostClass();
292 break;
293 case 0:
294 isAccessible =
295 env.toplevel.packge == c.owner // fast special case
296 ||
297 env.toplevel.packge == c.packge()
298 ||
299 // Hack: this case is added since synthesized default constructors
300 // of anonymous classes should be allowed to access
301 // classes which would be inaccessible otherwise.
302 env.enclMethod != null &&
303 (env.enclMethod.mods.flags & ANONCONSTR) != 0;
304 break;
305 default: // error recovery
306 case PUBLIC:
307 isAccessible = true;
308 break;
309 case PROTECTED:
310 isAccessible =
311 env.toplevel.packge == c.owner // fast special case
312 ||
313 env.toplevel.packge == c.packge()
314 ||
315 isInnerSubClass(env.enclClass.sym, c.owner);
316 break;
317 }
318 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
319 isAccessible :
320 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
321 }
322 //where
323 /** Is given class a subclass of given base class, or an inner class
324 * of a subclass?
325 * Return null if no such class exists.
326 * @param c The class which is the subclass or is contained in it.
327 * @param base The base class
328 */
329 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
330 while (c != null && !c.isSubClass(base, types)) {
331 c = c.owner.enclClass();
332 }
333 return c != null;
334 }
336 boolean isAccessible(Env<AttrContext> env, Type t) {
337 return isAccessible(env, t, false);
338 }
340 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) {
341 return (t.hasTag(ARRAY))
342 ? isAccessible(env, types.elemtype(t))
343 : isAccessible(env, t.tsym, checkInner);
344 }
346 /** Is symbol accessible as a member of given type in given evironment?
347 * @param env The current environment.
348 * @param site The type of which the tested symbol is regarded
349 * as a member.
350 * @param sym The symbol.
351 */
352 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
353 return isAccessible(env, site, sym, false);
354 }
355 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) {
356 if (sym.name == names.init && sym.owner != site.tsym) return false;
357 switch ((short)(sym.flags() & AccessFlags)) {
358 case PRIVATE:
359 return
360 (env.enclClass.sym == sym.owner // fast special case
361 ||
362 env.enclClass.sym.outermostClass() ==
363 sym.owner.outermostClass())
364 &&
365 sym.isInheritedIn(site.tsym, types);
366 case 0:
367 return
368 (env.toplevel.packge == sym.owner.owner // fast special case
369 ||
370 env.toplevel.packge == sym.packge())
371 &&
372 isAccessible(env, site, checkInner)
373 &&
374 sym.isInheritedIn(site.tsym, types)
375 &&
376 notOverriddenIn(site, sym);
377 case PROTECTED:
378 return
379 (env.toplevel.packge == sym.owner.owner // fast special case
380 ||
381 env.toplevel.packge == sym.packge()
382 ||
383 isProtectedAccessible(sym, env.enclClass.sym, site)
384 ||
385 // OK to select instance method or field from 'super' or type name
386 // (but type names should be disallowed elsewhere!)
387 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
388 &&
389 isAccessible(env, site, checkInner)
390 &&
391 notOverriddenIn(site, sym);
392 default: // this case includes erroneous combinations as well
393 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
394 }
395 }
396 //where
397 /* `sym' is accessible only if not overridden by
398 * another symbol which is a member of `site'
399 * (because, if it is overridden, `sym' is not strictly
400 * speaking a member of `site'). A polymorphic signature method
401 * cannot be overridden (e.g. MH.invokeExact(Object[])).
402 */
403 private boolean notOverriddenIn(Type site, Symbol sym) {
404 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
405 return true;
406 else {
407 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
408 return (s2 == null || s2 == sym || sym.owner == s2.owner ||
409 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
410 }
411 }
412 //where
413 /** Is given protected symbol accessible if it is selected from given site
414 * and the selection takes place in given class?
415 * @param sym The symbol with protected access
416 * @param c The class where the access takes place
417 * @site The type of the qualifier
418 */
419 private
420 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
421 while (c != null &&
422 !(c.isSubClass(sym.owner, types) &&
423 (c.flags() & INTERFACE) == 0 &&
424 // In JLS 2e 6.6.2.1, the subclass restriction applies
425 // only to instance fields and methods -- types are excluded
426 // regardless of whether they are declared 'static' or not.
427 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || site.tsym.isSubClass(c, types))))
428 c = c.owner.enclClass();
429 return c != null;
430 }
432 /**
433 * Performs a recursive scan of a type looking for accessibility problems
434 * from current attribution environment
435 */
436 void checkAccessibleType(Env<AttrContext> env, Type t) {
437 accessibilityChecker.visit(t, env);
438 }
440 /**
441 * Accessibility type-visitor
442 */
443 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker =
444 new Types.SimpleVisitor<Void, Env<AttrContext>>() {
446 void visit(List<Type> ts, Env<AttrContext> env) {
447 for (Type t : ts) {
448 visit(t, env);
449 }
450 }
452 public Void visitType(Type t, Env<AttrContext> env) {
453 return null;
454 }
456 @Override
457 public Void visitArrayType(ArrayType t, Env<AttrContext> env) {
458 visit(t.elemtype, env);
459 return null;
460 }
462 @Override
463 public Void visitClassType(ClassType t, Env<AttrContext> env) {
464 visit(t.getTypeArguments(), env);
465 if (!isAccessible(env, t, true)) {
466 accessBase(new AccessError(t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true);
467 }
468 return null;
469 }
471 @Override
472 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) {
473 visit(t.type, env);
474 return null;
475 }
477 @Override
478 public Void visitMethodType(MethodType t, Env<AttrContext> env) {
479 visit(t.getParameterTypes(), env);
480 visit(t.getReturnType(), env);
481 visit(t.getThrownTypes(), env);
482 return null;
483 }
484 };
486 /** Try to instantiate the type of a method so that it fits
487 * given type arguments and argument types. If succesful, return
488 * the method's instantiated type, else return null.
489 * The instantiation will take into account an additional leading
490 * formal parameter if the method is an instance method seen as a member
491 * of un underdetermined site In this case, we treat site as an additional
492 * parameter and the parameters of the class containing the method as
493 * additional type variables that get instantiated.
494 *
495 * @param env The current environment
496 * @param site The type of which the method is a member.
497 * @param m The method symbol.
498 * @param argtypes The invocation's given value arguments.
499 * @param typeargtypes The invocation's given type arguments.
500 * @param allowBoxing Allow boxing conversions of arguments.
501 * @param useVarargs Box trailing arguments into an array for varargs.
502 */
503 Type rawInstantiate(Env<AttrContext> env,
504 Type site,
505 Symbol m,
506 ResultInfo resultInfo,
507 List<Type> argtypes,
508 List<Type> typeargtypes,
509 boolean allowBoxing,
510 boolean useVarargs,
511 MethodCheck methodCheck,
512 Warner warn) throws Infer.InferenceException {
514 Type mt = types.memberType(site, m);
515 // tvars is the list of formal type variables for which type arguments
516 // need to inferred.
517 List<Type> tvars = List.nil();
518 if (typeargtypes == null) typeargtypes = List.nil();
519 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
520 // This is not a polymorphic method, but typeargs are supplied
521 // which is fine, see JLS 15.12.2.1
522 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
523 ForAll pmt = (ForAll) mt;
524 if (typeargtypes.length() != pmt.tvars.length())
525 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args
526 // Check type arguments are within bounds
527 List<Type> formals = pmt.tvars;
528 List<Type> actuals = typeargtypes;
529 while (formals.nonEmpty() && actuals.nonEmpty()) {
530 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
531 pmt.tvars, typeargtypes);
532 for (; bounds.nonEmpty(); bounds = bounds.tail)
533 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn))
534 throw inapplicableMethodException.setMessage("explicit.param.do.not.conform.to.bounds",actuals.head, bounds);
535 formals = formals.tail;
536 actuals = actuals.tail;
537 }
538 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
539 } else if (mt.hasTag(FORALL)) {
540 ForAll pmt = (ForAll) mt;
541 List<Type> tvars1 = types.newInstances(pmt.tvars);
542 tvars = tvars.appendList(tvars1);
543 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
544 }
546 // find out whether we need to go the slow route via infer
547 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/
548 for (List<Type> l = argtypes;
549 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
550 l = l.tail) {
551 if (l.head.hasTag(FORALL)) instNeeded = true;
552 }
554 if (instNeeded)
555 return infer.instantiateMethod(env,
556 tvars,
557 (MethodType)mt,
558 resultInfo,
559 m,
560 argtypes,
561 allowBoxing,
562 useVarargs,
563 currentResolutionContext,
564 methodCheck,
565 warn);
567 methodCheck.argumentsAcceptable(env, currentResolutionContext.deferredAttrContext(m, infer.emptyContext, resultInfo, warn),
568 argtypes, mt.getParameterTypes(), warn);
569 return mt;
570 }
572 Type checkMethod(Env<AttrContext> env,
573 Type site,
574 Symbol m,
575 ResultInfo resultInfo,
576 List<Type> argtypes,
577 List<Type> typeargtypes,
578 Warner warn) {
579 MethodResolutionContext prevContext = currentResolutionContext;
580 try {
581 currentResolutionContext = new MethodResolutionContext();
582 currentResolutionContext.attrMode = DeferredAttr.AttrMode.CHECK;
583 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase;
584 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
585 step.isBoxingRequired(), step.isVarargsRequired(), resolveMethodCheck, warn);
586 }
587 finally {
588 currentResolutionContext = prevContext;
589 }
590 }
592 /** Same but returns null instead throwing a NoInstanceException
593 */
594 Type instantiate(Env<AttrContext> env,
595 Type site,
596 Symbol m,
597 ResultInfo resultInfo,
598 List<Type> argtypes,
599 List<Type> typeargtypes,
600 boolean allowBoxing,
601 boolean useVarargs,
602 MethodCheck methodCheck,
603 Warner warn) {
604 try {
605 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
606 allowBoxing, useVarargs, methodCheck, warn);
607 } catch (InapplicableMethodException ex) {
608 return null;
609 }
610 }
612 /**
613 * This interface defines an entry point that should be used to perform a
614 * method check. A method check usually consist in determining as to whether
615 * a set of types (actuals) is compatible with another set of types (formals).
616 * Since the notion of compatibility can vary depending on the circumstances,
617 * this interfaces allows to easily add new pluggable method check routines.
618 */
619 interface MethodCheck {
620 /**
621 * Main method check routine. A method check usually consist in determining
622 * as to whether a set of types (actuals) is compatible with another set of
623 * types (formals). If an incompatibility is found, an unchecked exception
624 * is assumed to be thrown.
625 */
626 void argumentsAcceptable(Env<AttrContext> env,
627 DeferredAttrContext deferredAttrContext,
628 List<Type> argtypes,
629 List<Type> formals,
630 Warner warn);
631 }
633 /**
634 * Helper enum defining all method check diagnostics (used by resolveMethodCheck).
635 */
636 enum MethodCheckDiag {
637 /**
638 * Actuals and formals differs in length.
639 */
640 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"),
641 /**
642 * An actual is incompatible with a formal.
643 */
644 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"),
645 /**
646 * An actual is incompatible with the varargs element type.
647 */
648 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"),
649 /**
650 * The varargs element type is inaccessible.
651 */
652 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type");
654 final String basicKey;
655 final String inferKey;
657 MethodCheckDiag(String basicKey, String inferKey) {
658 this.basicKey = basicKey;
659 this.inferKey = inferKey;
660 }
661 }
663 /**
664 * Main method applicability routine. Given a list of actual types A,
665 * a list of formal types F, determines whether the types in A are
666 * compatible (by method invocation conversion) with the types in F.
667 *
668 * Since this routine is shared between overload resolution and method
669 * type-inference, a (possibly empty) inference context is used to convert
670 * formal types to the corresponding 'undet' form ahead of a compatibility
671 * check so that constraints can be propagated and collected.
672 *
673 * Moreover, if one or more types in A is a deferred type, this routine uses
674 * DeferredAttr in order to perform deferred attribution. If one or more actual
675 * deferred types are stuck, they are placed in a queue and revisited later
676 * after the remainder of the arguments have been seen. If this is not sufficient
677 * to 'unstuck' the argument, a cyclic inference error is called out.
678 *
679 * A method check handler (see above) is used in order to report errors.
680 */
681 MethodCheck resolveMethodCheck = new MethodCheck() {
682 @Override
683 public void argumentsAcceptable(final Env<AttrContext> env,
684 DeferredAttrContext deferredAttrContext,
685 List<Type> argtypes,
686 List<Type> formals,
687 Warner warn) {
688 //should we expand formals?
689 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired();
691 //inference context used during this method check
692 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
694 Type varargsFormal = useVarargs ? formals.last() : null;
696 if (varargsFormal == null &&
697 argtypes.size() != formals.size()) {
698 reportMC(MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
699 }
701 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
702 ResultInfo mresult = methodCheckResult(false, formals.head, deferredAttrContext, warn);
703 mresult.check(null, argtypes.head);
704 argtypes = argtypes.tail;
705 formals = formals.tail;
706 }
708 if (formals.head != varargsFormal) {
709 reportMC(MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
710 }
712 if (useVarargs) {
713 //note: if applicability check is triggered by most specific test,
714 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
715 final Type elt = types.elemtype(varargsFormal);
716 ResultInfo mresult = methodCheckResult(true, elt, deferredAttrContext, warn);
717 while (argtypes.nonEmpty()) {
718 mresult.check(null, argtypes.head);
719 argtypes = argtypes.tail;
720 }
721 //check varargs element type accessibility
722 varargsAccessible(env, elt, inferenceContext);
723 }
724 }
726 private void reportMC(MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
727 boolean inferDiag = inferenceContext != infer.emptyContext;
728 InapplicableMethodException ex = inferDiag ?
729 infer.inferenceException : inapplicableMethodException;
730 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) {
731 Object[] args2 = new Object[args.length + 1];
732 System.arraycopy(args, 0, args2, 1, args.length);
733 args2[0] = inferenceContext.inferenceVars();
734 args = args2;
735 }
736 throw ex.setMessage(inferDiag ? diag.inferKey : diag.basicKey, args);
737 }
739 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) {
740 if (inferenceContext.free(t)) {
741 inferenceContext.addFreeTypeListener(List.of(t), new FreeTypeListener() {
742 @Override
743 public void typesInferred(InferenceContext inferenceContext) {
744 varargsAccessible(env, inferenceContext.asInstType(t), inferenceContext);
745 }
746 });
747 } else {
748 if (!isAccessible(env, t)) {
749 Symbol location = env.enclClass.sym;
750 reportMC(MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
751 }
752 }
753 }
755 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
756 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
757 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
758 MethodCheckDiag methodDiag = varargsCheck ?
759 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
761 @Override
762 public void report(DiagnosticPosition pos, JCDiagnostic details) {
763 reportMC(methodDiag, deferredAttrContext.inferenceContext, details);
764 }
765 };
766 return new MethodResultInfo(to, checkContext);
767 }
768 };
770 /**
771 * Check context to be used during method applicability checks. A method check
772 * context might contain inference variables.
773 */
774 abstract class MethodCheckContext implements CheckContext {
776 boolean strict;
777 DeferredAttrContext deferredAttrContext;
778 Warner rsWarner;
780 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) {
781 this.strict = strict;
782 this.deferredAttrContext = deferredAttrContext;
783 this.rsWarner = rsWarner;
784 }
786 public boolean compatible(Type found, Type req, Warner warn) {
787 return strict ?
788 types.isSubtypeUnchecked(found, deferredAttrContext.inferenceContext.asFree(req), warn) :
789 types.isConvertible(found, deferredAttrContext.inferenceContext.asFree(req), warn);
790 }
792 public void report(DiagnosticPosition pos, JCDiagnostic details) {
793 throw inapplicableMethodException.setMessage(details);
794 }
796 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
797 return rsWarner;
798 }
800 public InferenceContext inferenceContext() {
801 return deferredAttrContext.inferenceContext;
802 }
804 public DeferredAttrContext deferredAttrContext() {
805 return deferredAttrContext;
806 }
807 }
809 /**
810 * ResultInfo class to be used during method applicability checks. Check
811 * for deferred types goes through special path.
812 */
813 class MethodResultInfo extends ResultInfo {
815 public MethodResultInfo(Type pt, CheckContext checkContext) {
816 attr.super(VAL, pt, checkContext);
817 }
819 @Override
820 protected Type check(DiagnosticPosition pos, Type found) {
821 if (found.hasTag(DEFERRED)) {
822 DeferredType dt = (DeferredType)found;
823 return dt.check(this);
824 } else {
825 return super.check(pos, chk.checkNonVoid(pos, types.capture(types.upperBound(found.baseType()))));
826 }
827 }
829 @Override
830 protected MethodResultInfo dup(Type newPt) {
831 return new MethodResultInfo(newPt, checkContext);
832 }
834 @Override
835 protected ResultInfo dup(CheckContext newContext) {
836 return new MethodResultInfo(pt, newContext);
837 }
838 }
840 /**
841 * Most specific method applicability routine. Given a list of actual types A,
842 * a list of formal types F1, and a list of formal types F2, the routine determines
843 * as to whether the types in F1 can be considered more specific than those in F2 w.r.t.
844 * argument types A.
845 */
846 class MostSpecificCheck implements MethodCheck {
848 boolean strict;
849 List<Type> actuals;
851 MostSpecificCheck(boolean strict, List<Type> actuals) {
852 this.strict = strict;
853 this.actuals = actuals;
854 }
856 @Override
857 public void argumentsAcceptable(final Env<AttrContext> env,
858 DeferredAttrContext deferredAttrContext,
859 List<Type> formals1,
860 List<Type> formals2,
861 Warner warn) {
862 formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired());
863 while (formals2.nonEmpty()) {
864 ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head);
865 mresult.check(null, formals1.head);
866 formals1 = formals1.tail;
867 formals2 = formals2.tail;
868 actuals = actuals.isEmpty() ? actuals : actuals.tail;
869 }
870 }
872 /**
873 * Create a method check context to be used during the most specific applicability check
874 */
875 ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext,
876 Warner rsWarner, Type actual) {
877 return attr.new ResultInfo(Kinds.VAL, to,
878 new MostSpecificCheckContext(strict, deferredAttrContext, rsWarner, actual));
879 }
881 /**
882 * Subclass of method check context class that implements most specific
883 * method conversion. If the actual type under analysis is a deferred type
884 * a full blown structural analysis is carried out.
885 */
886 class MostSpecificCheckContext extends MethodCheckContext {
888 Type actual;
890 public MostSpecificCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) {
891 super(strict, deferredAttrContext, rsWarner);
892 this.actual = actual;
893 }
895 public boolean compatible(Type found, Type req, Warner warn) {
896 if (!allowStructuralMostSpecific || actual == null) {
897 return super.compatible(found, req, warn);
898 } else {
899 switch (actual.getTag()) {
900 case DEFERRED:
901 DeferredType dt = (DeferredType) actual;
902 DeferredType.SpeculativeCache.Entry e = dt.speculativeCache.get(deferredAttrContext.msym, deferredAttrContext.phase);
903 return (e == null || e.speculativeTree == deferredAttr.stuckTree)
904 ? false : mostSpecific(found, req, e.speculativeTree, warn);
905 default:
906 return standaloneMostSpecific(found, req, actual, warn);
907 }
908 }
909 }
911 private boolean mostSpecific(Type t, Type s, JCTree tree, Warner warn) {
912 MostSpecificChecker msc = new MostSpecificChecker(t, s, warn);
913 msc.scan(tree);
914 return msc.result;
915 }
917 boolean polyMostSpecific(Type t1, Type t2, Warner warn) {
918 return (!t1.isPrimitive() && t2.isPrimitive())
919 ? true : super.compatible(t1, t2, warn);
920 }
922 boolean standaloneMostSpecific(Type t1, Type t2, Type exprType, Warner warn) {
923 return (exprType.isPrimitive() == t1.isPrimitive()
924 && exprType.isPrimitive() != t2.isPrimitive())
925 ? true : super.compatible(t1, t2, warn);
926 }
928 /**
929 * Structural checker for most specific.
930 */
931 class MostSpecificChecker extends DeferredAttr.PolyScanner {
933 final Type t;
934 final Type s;
935 final Warner warn;
936 boolean result;
938 MostSpecificChecker(Type t, Type s, Warner warn) {
939 this.t = t;
940 this.s = s;
941 this.warn = warn;
942 result = true;
943 }
945 @Override
946 void skip(JCTree tree) {
947 result &= standaloneMostSpecific(t, s, tree.type, warn);
948 }
950 @Override
951 public void visitConditional(JCConditional tree) {
952 if (tree.polyKind == PolyKind.STANDALONE) {
953 result &= standaloneMostSpecific(t, s, tree.type, warn);
954 } else {
955 super.visitConditional(tree);
956 }
957 }
959 @Override
960 public void visitApply(JCMethodInvocation tree) {
961 result &= (tree.polyKind == PolyKind.STANDALONE)
962 ? standaloneMostSpecific(t, s, tree.type, warn)
963 : polyMostSpecific(t, s, warn);
964 }
966 @Override
967 public void visitNewClass(JCNewClass tree) {
968 result &= (tree.polyKind == PolyKind.STANDALONE)
969 ? standaloneMostSpecific(t, s, tree.type, warn)
970 : polyMostSpecific(t, s, warn);
971 }
973 @Override
974 public void visitReference(JCMemberReference tree) {
975 if (types.isFunctionalInterface(t.tsym) &&
976 types.isFunctionalInterface(s.tsym) &&
977 types.asSuper(t, s.tsym) == null &&
978 types.asSuper(s, t.tsym) == null) {
979 Type desc_t = types.findDescriptorType(t);
980 Type desc_s = types.findDescriptorType(s);
981 if (types.isSameTypes(desc_t.getParameterTypes(), desc_s.getParameterTypes())) {
982 if (!desc_s.getReturnType().hasTag(VOID)) {
983 //perform structural comparison
984 Type ret_t = desc_t.getReturnType();
985 Type ret_s = desc_s.getReturnType();
986 result &= ((tree.refPolyKind == PolyKind.STANDALONE)
987 ? standaloneMostSpecific(ret_t, ret_s, tree.sym.type.getReturnType(), warn)
988 : polyMostSpecific(ret_t, ret_s, warn));
989 } else {
990 return;
991 }
992 } else {
993 result &= false;
994 }
995 } else {
996 result &= MostSpecificCheckContext.super.compatible(t, s, warn);
997 }
998 }
1000 @Override
1001 public void visitLambda(JCLambda tree) {
1002 if (types.isFunctionalInterface(t.tsym) &&
1003 types.isFunctionalInterface(s.tsym) &&
1004 types.asSuper(t, s.tsym) == null &&
1005 types.asSuper(s, t.tsym) == null) {
1006 Type desc_t = types.findDescriptorType(t);
1007 Type desc_s = types.findDescriptorType(s);
1008 if (tree.paramKind == JCLambda.ParameterKind.EXPLICIT
1009 || types.isSameTypes(desc_t.getParameterTypes(), desc_s.getParameterTypes())) {
1010 if (!desc_s.getReturnType().hasTag(VOID)) {
1011 //perform structural comparison
1012 Type ret_t = desc_t.getReturnType();
1013 Type ret_s = desc_s.getReturnType();
1014 scanLambdaBody(tree, ret_t, ret_s);
1015 } else {
1016 return;
1017 }
1018 } else {
1019 result &= false;
1020 }
1021 } else {
1022 result &= MostSpecificCheckContext.super.compatible(t, s, warn);
1023 }
1024 }
1025 //where
1027 void scanLambdaBody(JCLambda lambda, final Type t, final Type s) {
1028 if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) {
1029 result &= MostSpecificCheckContext.this.mostSpecific(t, s, lambda.body, warn);
1030 } else {
1031 DeferredAttr.LambdaReturnScanner lambdaScanner =
1032 new DeferredAttr.LambdaReturnScanner() {
1033 @Override
1034 public void visitReturn(JCReturn tree) {
1035 if (tree.expr != null) {
1036 result &= MostSpecificCheckContext.this.mostSpecific(t, s, tree.expr, warn);
1037 }
1038 }
1039 };
1040 lambdaScanner.scan(lambda.body);
1041 }
1042 }
1043 }
1044 }
1045 }
1047 public static class InapplicableMethodException extends RuntimeException {
1048 private static final long serialVersionUID = 0;
1050 JCDiagnostic diagnostic;
1051 JCDiagnostic.Factory diags;
1053 InapplicableMethodException(JCDiagnostic.Factory diags) {
1054 this.diagnostic = null;
1055 this.diags = diags;
1056 }
1057 InapplicableMethodException setMessage() {
1058 return setMessage((JCDiagnostic)null);
1059 }
1060 InapplicableMethodException setMessage(String key) {
1061 return setMessage(key != null ? diags.fragment(key) : null);
1062 }
1063 InapplicableMethodException setMessage(String key, Object... args) {
1064 return setMessage(key != null ? diags.fragment(key, args) : null);
1065 }
1066 InapplicableMethodException setMessage(JCDiagnostic diag) {
1067 this.diagnostic = diag;
1068 return this;
1069 }
1071 public JCDiagnostic getDiagnostic() {
1072 return diagnostic;
1073 }
1074 }
1075 private final InapplicableMethodException inapplicableMethodException;
1077 /* ***************************************************************************
1078 * Symbol lookup
1079 * the following naming conventions for arguments are used
1080 *
1081 * env is the environment where the symbol was mentioned
1082 * site is the type of which the symbol is a member
1083 * name is the symbol's name
1084 * if no arguments are given
1085 * argtypes are the value arguments, if we search for a method
1086 *
1087 * If no symbol was found, a ResolveError detailing the problem is returned.
1088 ****************************************************************************/
1090 /** Find field. Synthetic fields are always skipped.
1091 * @param env The current environment.
1092 * @param site The original type from where the selection takes place.
1093 * @param name The name of the field.
1094 * @param c The class to search for the field. This is always
1095 * a superclass or implemented interface of site's class.
1096 */
1097 Symbol findField(Env<AttrContext> env,
1098 Type site,
1099 Name name,
1100 TypeSymbol c) {
1101 while (c.type.hasTag(TYPEVAR))
1102 c = c.type.getUpperBound().tsym;
1103 Symbol bestSoFar = varNotFound;
1104 Symbol sym;
1105 Scope.Entry e = c.members().lookup(name);
1106 while (e.scope != null) {
1107 if (e.sym.kind == VAR && (e.sym.flags_field & SYNTHETIC) == 0) {
1108 return isAccessible(env, site, e.sym)
1109 ? e.sym : new AccessError(env, site, e.sym);
1110 }
1111 e = e.next();
1112 }
1113 Type st = types.supertype(c.type);
1114 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) {
1115 sym = findField(env, site, name, st.tsym);
1116 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1117 }
1118 for (List<Type> l = types.interfaces(c.type);
1119 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1120 l = l.tail) {
1121 sym = findField(env, site, name, l.head.tsym);
1122 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1123 sym.owner != bestSoFar.owner)
1124 bestSoFar = new AmbiguityError(bestSoFar, sym);
1125 else if (sym.kind < bestSoFar.kind)
1126 bestSoFar = sym;
1127 }
1128 return bestSoFar;
1129 }
1131 /** Resolve a field identifier, throw a fatal error if not found.
1132 * @param pos The position to use for error reporting.
1133 * @param env The environment current at the method invocation.
1134 * @param site The type of the qualifying expression, in which
1135 * identifier is searched.
1136 * @param name The identifier's name.
1137 */
1138 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
1139 Type site, Name name) {
1140 Symbol sym = findField(env, site, name, site.tsym);
1141 if (sym.kind == VAR) return (VarSymbol)sym;
1142 else throw new FatalError(
1143 diags.fragment("fatal.err.cant.locate.field",
1144 name));
1145 }
1147 /** Find unqualified variable or field with given name.
1148 * Synthetic fields always skipped.
1149 * @param env The current environment.
1150 * @param name The name of the variable or field.
1151 */
1152 Symbol findVar(Env<AttrContext> env, Name name) {
1153 Symbol bestSoFar = varNotFound;
1154 Symbol sym;
1155 Env<AttrContext> env1 = env;
1156 boolean staticOnly = false;
1157 while (env1.outer != null) {
1158 if (isStatic(env1)) staticOnly = true;
1159 Scope.Entry e = env1.info.scope.lookup(name);
1160 while (e.scope != null &&
1161 (e.sym.kind != VAR ||
1162 (e.sym.flags_field & SYNTHETIC) != 0))
1163 e = e.next();
1164 sym = (e.scope != null)
1165 ? e.sym
1166 : findField(
1167 env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
1168 if (sym.exists()) {
1169 if (staticOnly &&
1170 sym.kind == VAR &&
1171 sym.owner.kind == TYP &&
1172 (sym.flags() & STATIC) == 0)
1173 return new StaticError(sym);
1174 else
1175 return sym;
1176 } else if (sym.kind < bestSoFar.kind) {
1177 bestSoFar = sym;
1178 }
1180 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1181 env1 = env1.outer;
1182 }
1184 sym = findField(env, syms.predefClass.type, name, syms.predefClass);
1185 if (sym.exists())
1186 return sym;
1187 if (bestSoFar.exists())
1188 return bestSoFar;
1190 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
1191 for (; e.scope != null; e = e.next()) {
1192 sym = e.sym;
1193 Type origin = e.getOrigin().owner.type;
1194 if (sym.kind == VAR) {
1195 if (e.sym.owner.type != origin)
1196 sym = sym.clone(e.getOrigin().owner);
1197 return isAccessible(env, origin, sym)
1198 ? sym : new AccessError(env, origin, sym);
1199 }
1200 }
1202 Symbol origin = null;
1203 e = env.toplevel.starImportScope.lookup(name);
1204 for (; e.scope != null; e = e.next()) {
1205 sym = e.sym;
1206 if (sym.kind != VAR)
1207 continue;
1208 // invariant: sym.kind == VAR
1209 if (bestSoFar.kind < AMBIGUOUS && sym.owner != bestSoFar.owner)
1210 return new AmbiguityError(bestSoFar, sym);
1211 else if (bestSoFar.kind >= VAR) {
1212 origin = e.getOrigin().owner;
1213 bestSoFar = isAccessible(env, origin.type, sym)
1214 ? sym : new AccessError(env, origin.type, sym);
1215 }
1216 }
1217 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
1218 return bestSoFar.clone(origin);
1219 else
1220 return bestSoFar;
1221 }
1223 Warner noteWarner = new Warner();
1225 /** Select the best method for a call site among two choices.
1226 * @param env The current environment.
1227 * @param site The original type from where the
1228 * selection takes place.
1229 * @param argtypes The invocation's value arguments,
1230 * @param typeargtypes The invocation's type arguments,
1231 * @param sym Proposed new best match.
1232 * @param bestSoFar Previously found best match.
1233 * @param allowBoxing Allow boxing conversions of arguments.
1234 * @param useVarargs Box trailing arguments into an array for varargs.
1235 */
1236 @SuppressWarnings("fallthrough")
1237 Symbol selectBest(Env<AttrContext> env,
1238 Type site,
1239 List<Type> argtypes,
1240 List<Type> typeargtypes,
1241 Symbol sym,
1242 Symbol bestSoFar,
1243 boolean allowBoxing,
1244 boolean useVarargs,
1245 boolean operator) {
1246 if (sym.kind == ERR ||
1247 !sym.isInheritedIn(site.tsym, types)) {
1248 return bestSoFar;
1249 } else if (useVarargs && (sym.flags() & VARARGS) == 0) {
1250 return bestSoFar.kind >= ERRONEOUS ?
1251 new BadVarargsMethod((ResolveError)bestSoFar) :
1252 bestSoFar;
1253 }
1254 Assert.check(sym.kind < AMBIGUOUS);
1255 try {
1256 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes,
1257 allowBoxing, useVarargs, resolveMethodCheck, types.noWarnings);
1258 if (!operator)
1259 currentResolutionContext.addApplicableCandidate(sym, mt);
1260 } catch (InapplicableMethodException ex) {
1261 if (!operator)
1262 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic());
1263 switch (bestSoFar.kind) {
1264 case ABSENT_MTH:
1265 return new InapplicableSymbolError(currentResolutionContext);
1266 case WRONG_MTH:
1267 if (operator) return bestSoFar;
1268 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1269 default:
1270 return bestSoFar;
1271 }
1272 }
1273 if (!isAccessible(env, site, sym)) {
1274 return (bestSoFar.kind == ABSENT_MTH)
1275 ? new AccessError(env, site, sym)
1276 : bestSoFar;
1277 }
1278 return (bestSoFar.kind > AMBIGUOUS)
1279 ? sym
1280 : mostSpecific(argtypes, sym, bestSoFar, env, site,
1281 allowBoxing && operator, useVarargs);
1282 }
1284 /* Return the most specific of the two methods for a call,
1285 * given that both are accessible and applicable.
1286 * @param m1 A new candidate for most specific.
1287 * @param m2 The previous most specific candidate.
1288 * @param env The current environment.
1289 * @param site The original type from where the selection
1290 * takes place.
1291 * @param allowBoxing Allow boxing conversions of arguments.
1292 * @param useVarargs Box trailing arguments into an array for varargs.
1293 */
1294 Symbol mostSpecific(List<Type> argtypes, Symbol m1,
1295 Symbol m2,
1296 Env<AttrContext> env,
1297 final Type site,
1298 boolean allowBoxing,
1299 boolean useVarargs) {
1300 switch (m2.kind) {
1301 case MTH:
1302 if (m1 == m2) return m1;
1303 boolean m1SignatureMoreSpecific =
1304 signatureMoreSpecific(argtypes, env, site, m1, m2, allowBoxing, useVarargs);
1305 boolean m2SignatureMoreSpecific =
1306 signatureMoreSpecific(argtypes, env, site, m2, m1, allowBoxing, useVarargs);
1307 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
1308 Type mt1 = types.memberType(site, m1);
1309 Type mt2 = types.memberType(site, m2);
1310 if (!types.overrideEquivalent(mt1, mt2))
1311 return ambiguityError(m1, m2);
1313 // same signature; select (a) the non-bridge method, or
1314 // (b) the one that overrides the other, or (c) the concrete
1315 // one, or (d) merge both abstract signatures
1316 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
1317 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
1319 // if one overrides or hides the other, use it
1320 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
1321 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
1322 if (types.asSuper(m1Owner.type, m2Owner) != null &&
1323 ((m1.owner.flags_field & INTERFACE) == 0 ||
1324 (m2.owner.flags_field & INTERFACE) != 0) &&
1325 m1.overrides(m2, m1Owner, types, false))
1326 return m1;
1327 if (types.asSuper(m2Owner.type, m1Owner) != null &&
1328 ((m2.owner.flags_field & INTERFACE) == 0 ||
1329 (m1.owner.flags_field & INTERFACE) != 0) &&
1330 m2.overrides(m1, m2Owner, types, false))
1331 return m2;
1332 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
1333 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
1334 if (m1Abstract && !m2Abstract) return m2;
1335 if (m2Abstract && !m1Abstract) return m1;
1336 // both abstract or both concrete
1337 return ambiguityError(m1, m2);
1338 }
1339 if (m1SignatureMoreSpecific) return m1;
1340 if (m2SignatureMoreSpecific) return m2;
1341 return ambiguityError(m1, m2);
1342 case AMBIGUOUS:
1343 //check if m1 is more specific than all ambiguous methods in m2
1344 AmbiguityError e = (AmbiguityError)m2;
1345 for (Symbol s : e.ambiguousSyms) {
1346 if (mostSpecific(argtypes, m1, s, env, site, allowBoxing, useVarargs) != m1) {
1347 return e.addAmbiguousSymbol(m1);
1348 }
1349 }
1350 return m1;
1351 default:
1352 throw new AssertionError();
1353 }
1354 }
1355 //where
1356 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean allowBoxing, boolean useVarargs) {
1357 noteWarner.clear();
1358 int maxLength = Math.max(
1359 Math.max(m1.type.getParameterTypes().length(), actuals.length()),
1360 m2.type.getParameterTypes().length());
1361 Type mst = instantiate(env, site, m2, null,
1362 adjustArgs(types.lowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null,
1363 allowBoxing, useVarargs, new MostSpecificCheck(!allowBoxing, actuals), noteWarner);
1364 return mst != null &&
1365 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
1366 }
1367 private List<Type> adjustArgs(List<Type> args, Symbol msym, int length, boolean allowVarargs) {
1368 if ((msym.flags() & VARARGS) != 0 && allowVarargs) {
1369 Type varargsElem = types.elemtype(args.last());
1370 if (varargsElem == null) {
1371 Assert.error("Bad varargs = " + args.last() + " " + msym);
1372 }
1373 List<Type> newArgs = args.reverse().tail.prepend(varargsElem).reverse();
1374 while (newArgs.length() < length) {
1375 newArgs = newArgs.append(newArgs.last());
1376 }
1377 return newArgs;
1378 } else {
1379 return args;
1380 }
1381 }
1382 //where
1383 Type mostSpecificReturnType(Type mt1, Type mt2) {
1384 Type rt1 = mt1.getReturnType();
1385 Type rt2 = mt2.getReturnType();
1387 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL)) {
1388 //if both are generic methods, adjust return type ahead of subtyping check
1389 rt1 = types.subst(rt1, mt1.getTypeArguments(), mt2.getTypeArguments());
1390 }
1391 //first use subtyping, then return type substitutability
1392 if (types.isSubtype(rt1, rt2)) {
1393 return mt1;
1394 } else if (types.isSubtype(rt2, rt1)) {
1395 return mt2;
1396 } else if (types.returnTypeSubstitutable(mt1, mt2)) {
1397 return mt1;
1398 } else if (types.returnTypeSubstitutable(mt2, mt1)) {
1399 return mt2;
1400 } else {
1401 return null;
1402 }
1403 }
1404 //where
1405 Symbol ambiguityError(Symbol m1, Symbol m2) {
1406 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
1407 return (m1.flags() & CLASH) == 0 ? m1 : m2;
1408 } else {
1409 return new AmbiguityError(m1, m2);
1410 }
1411 }
1413 Symbol findMethodInScope(Env<AttrContext> env,
1414 Type site,
1415 Name name,
1416 List<Type> argtypes,
1417 List<Type> typeargtypes,
1418 Scope sc,
1419 Symbol bestSoFar,
1420 boolean allowBoxing,
1421 boolean useVarargs,
1422 boolean operator,
1423 boolean abstractok) {
1424 for (Symbol s : sc.getElementsByName(name, new LookupFilter(abstractok))) {
1425 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s,
1426 bestSoFar, allowBoxing, useVarargs, operator);
1427 }
1428 return bestSoFar;
1429 }
1430 //where
1431 class LookupFilter implements Filter<Symbol> {
1433 boolean abstractOk;
1435 LookupFilter(boolean abstractOk) {
1436 this.abstractOk = abstractOk;
1437 }
1439 public boolean accepts(Symbol s) {
1440 long flags = s.flags();
1441 return s.kind == MTH &&
1442 (flags & SYNTHETIC) == 0 &&
1443 (abstractOk ||
1444 (flags & DEFAULT) != 0 ||
1445 (flags & ABSTRACT) == 0);
1446 }
1447 };
1449 /** Find best qualified method matching given name, type and value
1450 * arguments.
1451 * @param env The current environment.
1452 * @param site The original type from where the selection
1453 * takes place.
1454 * @param name The method's name.
1455 * @param argtypes The method's value arguments.
1456 * @param typeargtypes The method's type arguments
1457 * @param allowBoxing Allow boxing conversions of arguments.
1458 * @param useVarargs Box trailing arguments into an array for varargs.
1459 */
1460 Symbol findMethod(Env<AttrContext> env,
1461 Type site,
1462 Name name,
1463 List<Type> argtypes,
1464 List<Type> typeargtypes,
1465 boolean allowBoxing,
1466 boolean useVarargs,
1467 boolean operator) {
1468 Symbol bestSoFar = methodNotFound;
1469 bestSoFar = findMethod(env,
1470 site,
1471 name,
1472 argtypes,
1473 typeargtypes,
1474 site.tsym.type,
1475 bestSoFar,
1476 allowBoxing,
1477 useVarargs,
1478 operator);
1479 reportVerboseResolutionDiagnostic(env.tree.pos(), name, site, argtypes, typeargtypes, bestSoFar);
1480 return bestSoFar;
1481 }
1482 // where
1483 private Symbol findMethod(Env<AttrContext> env,
1484 Type site,
1485 Name name,
1486 List<Type> argtypes,
1487 List<Type> typeargtypes,
1488 Type intype,
1489 Symbol bestSoFar,
1490 boolean allowBoxing,
1491 boolean useVarargs,
1492 boolean operator) {
1493 @SuppressWarnings({"unchecked","rawtypes"})
1494 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() };
1495 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK;
1496 for (TypeSymbol s : superclasses(intype)) {
1497 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1498 s.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1499 if (name == names.init) return bestSoFar;
1500 iphase = (iphase == null) ? null : iphase.update(s, this);
1501 if (iphase != null) {
1502 for (Type itype : types.interfaces(s.type)) {
1503 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]);
1504 }
1505 }
1506 }
1508 Symbol concrete = bestSoFar.kind < ERR &&
1509 (bestSoFar.flags() & ABSTRACT) == 0 ?
1510 bestSoFar : methodNotFound;
1512 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) {
1513 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK && !allowDefaultMethods) break;
1514 //keep searching for abstract methods
1515 for (Type itype : itypes[iphase2.ordinal()]) {
1516 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure())
1517 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK &&
1518 (itype.tsym.flags() & DEFAULT) == 0) continue;
1519 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1520 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1521 if (concrete != bestSoFar &&
1522 concrete.kind < ERR && bestSoFar.kind < ERR &&
1523 types.isSubSignature(concrete.type, bestSoFar.type)) {
1524 //this is an hack - as javac does not do full membership checks
1525 //most specific ends up comparing abstract methods that might have
1526 //been implemented by some concrete method in a subclass and,
1527 //because of raw override, it is possible for an abstract method
1528 //to be more specific than the concrete method - so we need
1529 //to explicitly call that out (see CR 6178365)
1530 bestSoFar = concrete;
1531 }
1532 }
1533 }
1534 return bestSoFar;
1535 }
1537 enum InterfaceLookupPhase {
1538 ABSTRACT_OK() {
1539 @Override
1540 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1541 //We should not look for abstract methods if receiver is a concrete class
1542 //(as concrete classes are expected to implement all abstracts coming
1543 //from superinterfaces)
1544 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) {
1545 return this;
1546 } else if (rs.allowDefaultMethods) {
1547 return DEFAULT_OK;
1548 } else {
1549 return null;
1550 }
1551 }
1552 },
1553 DEFAULT_OK() {
1554 @Override
1555 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1556 return this;
1557 }
1558 };
1560 abstract InterfaceLookupPhase update(Symbol s, Resolve rs);
1561 }
1563 /**
1564 * Return an Iterable object to scan the superclasses of a given type.
1565 * It's crucial that the scan is done lazily, as we don't want to accidentally
1566 * access more supertypes than strictly needed (as this could trigger completion
1567 * errors if some of the not-needed supertypes are missing/ill-formed).
1568 */
1569 Iterable<TypeSymbol> superclasses(final Type intype) {
1570 return new Iterable<TypeSymbol>() {
1571 public Iterator<TypeSymbol> iterator() {
1572 return new Iterator<TypeSymbol>() {
1574 List<TypeSymbol> seen = List.nil();
1575 TypeSymbol currentSym = symbolFor(intype);
1576 TypeSymbol prevSym = null;
1578 public boolean hasNext() {
1579 if (currentSym == syms.noSymbol) {
1580 currentSym = symbolFor(types.supertype(prevSym.type));
1581 }
1582 return currentSym != null;
1583 }
1585 public TypeSymbol next() {
1586 prevSym = currentSym;
1587 currentSym = syms.noSymbol;
1588 Assert.check(prevSym != null || prevSym != syms.noSymbol);
1589 return prevSym;
1590 }
1592 public void remove() {
1593 throw new UnsupportedOperationException();
1594 }
1596 TypeSymbol symbolFor(Type t) {
1597 if (!t.hasTag(CLASS) &&
1598 !t.hasTag(TYPEVAR)) {
1599 return null;
1600 }
1601 while (t.hasTag(TYPEVAR))
1602 t = t.getUpperBound();
1603 if (seen.contains(t.tsym)) {
1604 //degenerate case in which we have a circular
1605 //class hierarchy - because of ill-formed classfiles
1606 return null;
1607 }
1608 seen = seen.prepend(t.tsym);
1609 return t.tsym;
1610 }
1611 };
1612 }
1613 };
1614 }
1616 /** Find unqualified method matching given name, type and value arguments.
1617 * @param env The current environment.
1618 * @param name The method's name.
1619 * @param argtypes The method's value arguments.
1620 * @param typeargtypes The method's type arguments.
1621 * @param allowBoxing Allow boxing conversions of arguments.
1622 * @param useVarargs Box trailing arguments into an array for varargs.
1623 */
1624 Symbol findFun(Env<AttrContext> env, Name name,
1625 List<Type> argtypes, List<Type> typeargtypes,
1626 boolean allowBoxing, boolean useVarargs) {
1627 Symbol bestSoFar = methodNotFound;
1628 Symbol sym;
1629 Env<AttrContext> env1 = env;
1630 boolean staticOnly = false;
1631 while (env1.outer != null) {
1632 if (isStatic(env1)) staticOnly = true;
1633 sym = findMethod(
1634 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
1635 allowBoxing, useVarargs, false);
1636 if (sym.exists()) {
1637 if (staticOnly &&
1638 sym.kind == MTH &&
1639 sym.owner.kind == TYP &&
1640 (sym.flags() & STATIC) == 0) return new StaticError(sym);
1641 else return sym;
1642 } else if (sym.kind < bestSoFar.kind) {
1643 bestSoFar = sym;
1644 }
1645 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1646 env1 = env1.outer;
1647 }
1649 sym = findMethod(env, syms.predefClass.type, name, argtypes,
1650 typeargtypes, allowBoxing, useVarargs, false);
1651 if (sym.exists())
1652 return sym;
1654 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
1655 for (; e.scope != null; e = e.next()) {
1656 sym = e.sym;
1657 Type origin = e.getOrigin().owner.type;
1658 if (sym.kind == MTH) {
1659 if (e.sym.owner.type != origin)
1660 sym = sym.clone(e.getOrigin().owner);
1661 if (!isAccessible(env, origin, sym))
1662 sym = new AccessError(env, origin, sym);
1663 bestSoFar = selectBest(env, origin,
1664 argtypes, typeargtypes,
1665 sym, bestSoFar,
1666 allowBoxing, useVarargs, false);
1667 }
1668 }
1669 if (bestSoFar.exists())
1670 return bestSoFar;
1672 e = env.toplevel.starImportScope.lookup(name);
1673 for (; e.scope != null; e = e.next()) {
1674 sym = e.sym;
1675 Type origin = e.getOrigin().owner.type;
1676 if (sym.kind == MTH) {
1677 if (e.sym.owner.type != origin)
1678 sym = sym.clone(e.getOrigin().owner);
1679 if (!isAccessible(env, origin, sym))
1680 sym = new AccessError(env, origin, sym);
1681 bestSoFar = selectBest(env, origin,
1682 argtypes, typeargtypes,
1683 sym, bestSoFar,
1684 allowBoxing, useVarargs, false);
1685 }
1686 }
1687 return bestSoFar;
1688 }
1690 /** Load toplevel or member class with given fully qualified name and
1691 * verify that it is accessible.
1692 * @param env The current environment.
1693 * @param name The fully qualified name of the class to be loaded.
1694 */
1695 Symbol loadClass(Env<AttrContext> env, Name name) {
1696 try {
1697 ClassSymbol c = reader.loadClass(name);
1698 return isAccessible(env, c) ? c : new AccessError(c);
1699 } catch (ClassReader.BadClassFile err) {
1700 throw err;
1701 } catch (CompletionFailure ex) {
1702 return typeNotFound;
1703 }
1704 }
1706 /** Find qualified member type.
1707 * @param env The current environment.
1708 * @param site The original type from where the selection takes
1709 * place.
1710 * @param name The type's name.
1711 * @param c The class to search for the member type. This is
1712 * always a superclass or implemented interface of
1713 * site's class.
1714 */
1715 Symbol findMemberType(Env<AttrContext> env,
1716 Type site,
1717 Name name,
1718 TypeSymbol c) {
1719 Symbol bestSoFar = typeNotFound;
1720 Symbol sym;
1721 Scope.Entry e = c.members().lookup(name);
1722 while (e.scope != null) {
1723 if (e.sym.kind == TYP) {
1724 return isAccessible(env, site, e.sym)
1725 ? e.sym
1726 : new AccessError(env, site, e.sym);
1727 }
1728 e = e.next();
1729 }
1730 Type st = types.supertype(c.type);
1731 if (st != null && st.hasTag(CLASS)) {
1732 sym = findMemberType(env, site, name, st.tsym);
1733 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1734 }
1735 for (List<Type> l = types.interfaces(c.type);
1736 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1737 l = l.tail) {
1738 sym = findMemberType(env, site, name, l.head.tsym);
1739 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1740 sym.owner != bestSoFar.owner)
1741 bestSoFar = new AmbiguityError(bestSoFar, sym);
1742 else if (sym.kind < bestSoFar.kind)
1743 bestSoFar = sym;
1744 }
1745 return bestSoFar;
1746 }
1748 /** Find a global type in given scope and load corresponding class.
1749 * @param env The current environment.
1750 * @param scope The scope in which to look for the type.
1751 * @param name The type's name.
1752 */
1753 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) {
1754 Symbol bestSoFar = typeNotFound;
1755 for (Scope.Entry e = scope.lookup(name); e.scope != null; e = e.next()) {
1756 Symbol sym = loadClass(env, e.sym.flatName());
1757 if (bestSoFar.kind == TYP && sym.kind == TYP &&
1758 bestSoFar != sym)
1759 return new AmbiguityError(bestSoFar, sym);
1760 else if (sym.kind < bestSoFar.kind)
1761 bestSoFar = sym;
1762 }
1763 return bestSoFar;
1764 }
1766 /** Find an unqualified type symbol.
1767 * @param env The current environment.
1768 * @param name The type's name.
1769 */
1770 Symbol findType(Env<AttrContext> env, Name name) {
1771 Symbol bestSoFar = typeNotFound;
1772 Symbol sym;
1773 boolean staticOnly = false;
1774 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
1775 if (isStatic(env1)) staticOnly = true;
1776 for (Scope.Entry e = env1.info.scope.lookup(name);
1777 e.scope != null;
1778 e = e.next()) {
1779 if (e.sym.kind == TYP) {
1780 if (staticOnly &&
1781 e.sym.type.hasTag(TYPEVAR) &&
1782 e.sym.owner.kind == TYP) return new StaticError(e.sym);
1783 return e.sym;
1784 }
1785 }
1787 sym = findMemberType(env1, env1.enclClass.sym.type, name,
1788 env1.enclClass.sym);
1789 if (staticOnly && sym.kind == TYP &&
1790 sym.type.hasTag(CLASS) &&
1791 sym.type.getEnclosingType().hasTag(CLASS) &&
1792 env1.enclClass.sym.type.isParameterized() &&
1793 sym.type.getEnclosingType().isParameterized())
1794 return new StaticError(sym);
1795 else if (sym.exists()) return sym;
1796 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1798 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
1799 if ((encl.sym.flags() & STATIC) != 0)
1800 staticOnly = true;
1801 }
1803 if (!env.tree.hasTag(IMPORT)) {
1804 sym = findGlobalType(env, env.toplevel.namedImportScope, name);
1805 if (sym.exists()) return sym;
1806 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1808 sym = findGlobalType(env, env.toplevel.packge.members(), name);
1809 if (sym.exists()) return sym;
1810 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1812 sym = findGlobalType(env, env.toplevel.starImportScope, name);
1813 if (sym.exists()) return sym;
1814 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1815 }
1817 return bestSoFar;
1818 }
1820 /** Find an unqualified identifier which matches a specified kind set.
1821 * @param env The current environment.
1822 * @param name The identifier's name.
1823 * @param kind Indicates the possible symbol kinds
1824 * (a subset of VAL, TYP, PCK).
1825 */
1826 Symbol findIdent(Env<AttrContext> env, Name name, int kind) {
1827 Symbol bestSoFar = typeNotFound;
1828 Symbol sym;
1830 if ((kind & VAR) != 0) {
1831 sym = findVar(env, name);
1832 if (sym.exists()) return sym;
1833 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1834 }
1836 if ((kind & TYP) != 0) {
1837 sym = findType(env, name);
1838 if (sym.kind==TYP) {
1839 reportDependence(env.enclClass.sym, sym);
1840 }
1841 if (sym.exists()) return sym;
1842 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1843 }
1845 if ((kind & PCK) != 0) return reader.enterPackage(name);
1846 else return bestSoFar;
1847 }
1849 /** Report dependencies.
1850 * @param from The enclosing class sym
1851 * @param to The found identifier that the class depends on.
1852 */
1853 public void reportDependence(Symbol from, Symbol to) {
1854 // Override if you want to collect the reported dependencies.
1855 }
1857 /** Find an identifier in a package which matches a specified kind set.
1858 * @param env The current environment.
1859 * @param name The identifier's name.
1860 * @param kind Indicates the possible symbol kinds
1861 * (a nonempty subset of TYP, PCK).
1862 */
1863 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
1864 Name name, int kind) {
1865 Name fullname = TypeSymbol.formFullName(name, pck);
1866 Symbol bestSoFar = typeNotFound;
1867 PackageSymbol pack = null;
1868 if ((kind & PCK) != 0) {
1869 pack = reader.enterPackage(fullname);
1870 if (pack.exists()) return pack;
1871 }
1872 if ((kind & TYP) != 0) {
1873 Symbol sym = loadClass(env, fullname);
1874 if (sym.exists()) {
1875 // don't allow programs to use flatnames
1876 if (name == sym.name) return sym;
1877 }
1878 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1879 }
1880 return (pack != null) ? pack : bestSoFar;
1881 }
1883 /** Find an identifier among the members of a given type `site'.
1884 * @param env The current environment.
1885 * @param site The type containing the symbol to be found.
1886 * @param name The identifier's name.
1887 * @param kind Indicates the possible symbol kinds
1888 * (a subset of VAL, TYP).
1889 */
1890 Symbol findIdentInType(Env<AttrContext> env, Type site,
1891 Name name, int kind) {
1892 Symbol bestSoFar = typeNotFound;
1893 Symbol sym;
1894 if ((kind & VAR) != 0) {
1895 sym = findField(env, site, name, site.tsym);
1896 if (sym.exists()) return sym;
1897 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1898 }
1900 if ((kind & TYP) != 0) {
1901 sym = findMemberType(env, site, name, site.tsym);
1902 if (sym.exists()) return sym;
1903 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1904 }
1905 return bestSoFar;
1906 }
1908 /* ***************************************************************************
1909 * Access checking
1910 * The following methods convert ResolveErrors to ErrorSymbols, issuing
1911 * an error message in the process
1912 ****************************************************************************/
1914 /** If `sym' is a bad symbol: report error and return errSymbol
1915 * else pass through unchanged,
1916 * additional arguments duplicate what has been used in trying to find the
1917 * symbol {@literal (--> flyweight pattern)}. This improves performance since we
1918 * expect misses to happen frequently.
1919 *
1920 * @param sym The symbol that was found, or a ResolveError.
1921 * @param pos The position to use for error reporting.
1922 * @param location The symbol the served as a context for this lookup
1923 * @param site The original type from where the selection took place.
1924 * @param name The symbol's name.
1925 * @param qualified Did we get here through a qualified expression resolution?
1926 * @param argtypes The invocation's value arguments,
1927 * if we looked for a method.
1928 * @param typeargtypes The invocation's type arguments,
1929 * if we looked for a method.
1930 * @param logResolveHelper helper class used to log resolve errors
1931 */
1932 Symbol accessInternal(Symbol sym,
1933 DiagnosticPosition pos,
1934 Symbol location,
1935 Type site,
1936 Name name,
1937 boolean qualified,
1938 List<Type> argtypes,
1939 List<Type> typeargtypes,
1940 LogResolveHelper logResolveHelper) {
1941 if (sym.kind >= AMBIGUOUS) {
1942 ResolveError errSym = (ResolveError)sym;
1943 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
1944 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes);
1945 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) {
1946 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
1947 }
1948 }
1949 return sym;
1950 }
1952 /**
1953 * Variant of the generalized access routine, to be used for generating method
1954 * resolution diagnostics
1955 */
1956 Symbol accessMethod(Symbol sym,
1957 DiagnosticPosition pos,
1958 Symbol location,
1959 Type site,
1960 Name name,
1961 boolean qualified,
1962 List<Type> argtypes,
1963 List<Type> typeargtypes) {
1964 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper);
1965 }
1967 /** Same as original accessMethod(), but without location.
1968 */
1969 Symbol accessMethod(Symbol sym,
1970 DiagnosticPosition pos,
1971 Type site,
1972 Name name,
1973 boolean qualified,
1974 List<Type> argtypes,
1975 List<Type> typeargtypes) {
1976 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
1977 }
1979 /**
1980 * Variant of the generalized access routine, to be used for generating variable,
1981 * type resolution diagnostics
1982 */
1983 Symbol accessBase(Symbol sym,
1984 DiagnosticPosition pos,
1985 Symbol location,
1986 Type site,
1987 Name name,
1988 boolean qualified) {
1989 return accessInternal(sym, pos, location, site, name, qualified, List.<Type>nil(), null, basicLogResolveHelper);
1990 }
1992 /** Same as original accessBase(), but without location.
1993 */
1994 Symbol accessBase(Symbol sym,
1995 DiagnosticPosition pos,
1996 Type site,
1997 Name name,
1998 boolean qualified) {
1999 return accessBase(sym, pos, site.tsym, site, name, qualified);
2000 }
2002 interface LogResolveHelper {
2003 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes);
2004 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes);
2005 }
2007 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() {
2008 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2009 return !site.isErroneous();
2010 }
2011 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2012 return argtypes;
2013 }
2014 };
2016 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() {
2017 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2018 return !site.isErroneous() &&
2019 !Type.isErroneous(argtypes) &&
2020 (typeargtypes == null || !Type.isErroneous(typeargtypes));
2021 }
2022 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2023 return (syms.operatorNames.contains(name)) ?
2024 argtypes :
2025 Type.map(argtypes, new ResolveDeferredRecoveryMap(accessedSym));
2026 }
2028 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap {
2030 public ResolveDeferredRecoveryMap(Symbol msym) {
2031 deferredAttr.super(AttrMode.SPECULATIVE, msym, currentResolutionContext.step);
2032 }
2034 @Override
2035 protected Type typeOf(DeferredType dt) {
2036 Type res = super.typeOf(dt);
2037 if (!res.isErroneous()) {
2038 switch (TreeInfo.skipParens(dt.tree).getTag()) {
2039 case LAMBDA:
2040 case REFERENCE:
2041 return dt;
2042 case CONDEXPR:
2043 return res == Type.recoveryType ?
2044 dt : res;
2045 }
2046 }
2047 return res;
2048 }
2049 }
2050 };
2052 /** Check that sym is not an abstract method.
2053 */
2054 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
2055 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0)
2056 log.error(pos, "abstract.cant.be.accessed.directly",
2057 kindName(sym), sym, sym.location());
2058 }
2060 /* ***************************************************************************
2061 * Debugging
2062 ****************************************************************************/
2064 /** print all scopes starting with scope s and proceeding outwards.
2065 * used for debugging.
2066 */
2067 public void printscopes(Scope s) {
2068 while (s != null) {
2069 if (s.owner != null)
2070 System.err.print(s.owner + ": ");
2071 for (Scope.Entry e = s.elems; e != null; e = e.sibling) {
2072 if ((e.sym.flags() & ABSTRACT) != 0)
2073 System.err.print("abstract ");
2074 System.err.print(e.sym + " ");
2075 }
2076 System.err.println();
2077 s = s.next;
2078 }
2079 }
2081 void printscopes(Env<AttrContext> env) {
2082 while (env.outer != null) {
2083 System.err.println("------------------------------");
2084 printscopes(env.info.scope);
2085 env = env.outer;
2086 }
2087 }
2089 public void printscopes(Type t) {
2090 while (t.hasTag(CLASS)) {
2091 printscopes(t.tsym.members());
2092 t = types.supertype(t);
2093 }
2094 }
2096 /* ***************************************************************************
2097 * Name resolution
2098 * Naming conventions are as for symbol lookup
2099 * Unlike the find... methods these methods will report access errors
2100 ****************************************************************************/
2102 /** Resolve an unqualified (non-method) identifier.
2103 * @param pos The position to use for error reporting.
2104 * @param env The environment current at the identifier use.
2105 * @param name The identifier's name.
2106 * @param kind The set of admissible symbol kinds for the identifier.
2107 */
2108 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
2109 Name name, int kind) {
2110 return accessBase(
2111 findIdent(env, name, kind),
2112 pos, env.enclClass.sym.type, name, false);
2113 }
2115 /** Resolve an unqualified method identifier.
2116 * @param pos The position to use for error reporting.
2117 * @param env The environment current at the method invocation.
2118 * @param name The identifier's name.
2119 * @param argtypes The types of the invocation's value arguments.
2120 * @param typeargtypes The types of the invocation's type arguments.
2121 */
2122 Symbol resolveMethod(DiagnosticPosition pos,
2123 Env<AttrContext> env,
2124 Name name,
2125 List<Type> argtypes,
2126 List<Type> typeargtypes) {
2127 return lookupMethod(env, pos, env.enclClass.sym, new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) {
2128 @Override
2129 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2130 return findFun(env, name, argtypes, typeargtypes,
2131 phase.isBoxingRequired(),
2132 phase.isVarargsRequired());
2133 }
2134 });
2135 }
2137 /** Resolve a qualified method identifier
2138 * @param pos The position to use for error reporting.
2139 * @param env The environment current at the method invocation.
2140 * @param site The type of the qualifying expression, in which
2141 * identifier is searched.
2142 * @param name The identifier's name.
2143 * @param argtypes The types of the invocation's value arguments.
2144 * @param typeargtypes The types of the invocation's type arguments.
2145 */
2146 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2147 Type site, Name name, List<Type> argtypes,
2148 List<Type> typeargtypes) {
2149 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
2150 }
2151 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2152 Symbol location, Type site, Name name, List<Type> argtypes,
2153 List<Type> typeargtypes) {
2154 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
2155 }
2156 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
2157 DiagnosticPosition pos, Env<AttrContext> env,
2158 Symbol location, Type site, Name name, List<Type> argtypes,
2159 List<Type> typeargtypes) {
2160 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) {
2161 @Override
2162 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2163 return findMethod(env, site, name, argtypes, typeargtypes,
2164 phase.isBoxingRequired(),
2165 phase.isVarargsRequired(), false);
2166 }
2167 @Override
2168 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2169 if (sym.kind >= AMBIGUOUS) {
2170 sym = super.access(env, pos, location, sym);
2171 } else if (allowMethodHandles) {
2172 MethodSymbol msym = (MethodSymbol)sym;
2173 if (msym.isSignaturePolymorphic(types)) {
2174 return findPolymorphicSignatureInstance(env, sym, argtypes);
2175 }
2176 }
2177 return sym;
2178 }
2179 });
2180 }
2182 /** Find or create an implicit method of exactly the given type (after erasure).
2183 * Searches in a side table, not the main scope of the site.
2184 * This emulates the lookup process required by JSR 292 in JVM.
2185 * @param env Attribution environment
2186 * @param spMethod signature polymorphic method - i.e. MH.invokeExact
2187 * @param argtypes The required argument types
2188 */
2189 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env,
2190 final Symbol spMethod,
2191 List<Type> argtypes) {
2192 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
2193 (MethodSymbol)spMethod, currentResolutionContext, argtypes);
2194 for (Symbol sym : polymorphicSignatureScope.getElementsByName(spMethod.name)) {
2195 if (types.isSameType(mtype, sym.type)) {
2196 return sym;
2197 }
2198 }
2200 // create the desired method
2201 long flags = ABSTRACT | HYPOTHETICAL | spMethod.flags() & Flags.AccessFlags;
2202 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) {
2203 @Override
2204 public Symbol baseSymbol() {
2205 return spMethod;
2206 }
2207 };
2208 polymorphicSignatureScope.enter(msym);
2209 return msym;
2210 }
2212 /** Resolve a qualified method identifier, throw a fatal error if not
2213 * found.
2214 * @param pos The position to use for error reporting.
2215 * @param env The environment current at the method invocation.
2216 * @param site The type of the qualifying expression, in which
2217 * identifier is searched.
2218 * @param name The identifier's name.
2219 * @param argtypes The types of the invocation's value arguments.
2220 * @param typeargtypes The types of the invocation's type arguments.
2221 */
2222 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
2223 Type site, Name name,
2224 List<Type> argtypes,
2225 List<Type> typeargtypes) {
2226 MethodResolutionContext resolveContext = new MethodResolutionContext();
2227 resolveContext.internalResolution = true;
2228 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
2229 site, name, argtypes, typeargtypes);
2230 if (sym.kind == MTH) return (MethodSymbol)sym;
2231 else throw new FatalError(
2232 diags.fragment("fatal.err.cant.locate.meth",
2233 name));
2234 }
2236 /** Resolve constructor.
2237 * @param pos The position to use for error reporting.
2238 * @param env The environment current at the constructor invocation.
2239 * @param site The type of class for which a constructor is searched.
2240 * @param argtypes The types of the constructor invocation's value
2241 * arguments.
2242 * @param typeargtypes The types of the constructor invocation's type
2243 * arguments.
2244 */
2245 Symbol resolveConstructor(DiagnosticPosition pos,
2246 Env<AttrContext> env,
2247 Type site,
2248 List<Type> argtypes,
2249 List<Type> typeargtypes) {
2250 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
2251 }
2253 private Symbol resolveConstructor(MethodResolutionContext resolveContext,
2254 final DiagnosticPosition pos,
2255 Env<AttrContext> env,
2256 Type site,
2257 List<Type> argtypes,
2258 List<Type> typeargtypes) {
2259 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2260 @Override
2261 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2262 return findConstructor(pos, env, site, argtypes, typeargtypes,
2263 phase.isBoxingRequired(),
2264 phase.isVarargsRequired());
2265 }
2266 });
2267 }
2269 /** Resolve a constructor, throw a fatal error if not found.
2270 * @param pos The position to use for error reporting.
2271 * @param env The environment current at the method invocation.
2272 * @param site The type to be constructed.
2273 * @param argtypes The types of the invocation's value arguments.
2274 * @param typeargtypes The types of the invocation's type arguments.
2275 */
2276 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2277 Type site,
2278 List<Type> argtypes,
2279 List<Type> typeargtypes) {
2280 MethodResolutionContext resolveContext = new MethodResolutionContext();
2281 resolveContext.internalResolution = true;
2282 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
2283 if (sym.kind == MTH) return (MethodSymbol)sym;
2284 else throw new FatalError(
2285 diags.fragment("fatal.err.cant.locate.ctor", site));
2286 }
2288 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2289 Type site, List<Type> argtypes,
2290 List<Type> typeargtypes,
2291 boolean allowBoxing,
2292 boolean useVarargs) {
2293 Symbol sym = findMethod(env, site,
2294 names.init, argtypes,
2295 typeargtypes, allowBoxing,
2296 useVarargs, false);
2297 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2298 return sym;
2299 }
2301 /** Resolve constructor using diamond inference.
2302 * @param pos The position to use for error reporting.
2303 * @param env The environment current at the constructor invocation.
2304 * @param site The type of class for which a constructor is searched.
2305 * The scope of this class has been touched in attribution.
2306 * @param argtypes The types of the constructor invocation's value
2307 * arguments.
2308 * @param typeargtypes The types of the constructor invocation's type
2309 * arguments.
2310 */
2311 Symbol resolveDiamond(DiagnosticPosition pos,
2312 Env<AttrContext> env,
2313 Type site,
2314 List<Type> argtypes,
2315 List<Type> typeargtypes) {
2316 return lookupMethod(env, pos, site.tsym, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2317 @Override
2318 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2319 return findDiamond(env, site, argtypes, typeargtypes,
2320 phase.isBoxingRequired(),
2321 phase.isVarargsRequired());
2322 }
2323 @Override
2324 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2325 if (sym.kind >= AMBIGUOUS) {
2326 final JCDiagnostic details = sym.kind == WRONG_MTH ?
2327 ((InapplicableSymbolError)sym).errCandidate().details :
2328 null;
2329 sym = new InapplicableSymbolError(sym.kind, "diamondError", currentResolutionContext) {
2330 @Override
2331 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
2332 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
2333 String key = details == null ?
2334 "cant.apply.diamond" :
2335 "cant.apply.diamond.1";
2336 return diags.create(dkind, log.currentSource(), pos, key,
2337 diags.fragment("diamond", site.tsym), details);
2338 }
2339 };
2340 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes);
2341 env.info.pendingResolutionPhase = currentResolutionContext.step;
2342 }
2343 return sym;
2344 }
2345 });
2346 }
2348 /** This method scans all the constructor symbol in a given class scope -
2349 * assuming that the original scope contains a constructor of the kind:
2350 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
2351 * a method check is executed against the modified constructor type:
2352 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond
2353 * inference. The inferred return type of the synthetic constructor IS
2354 * the inferred type for the diamond operator.
2355 */
2356 private Symbol findDiamond(Env<AttrContext> env,
2357 Type site,
2358 List<Type> argtypes,
2359 List<Type> typeargtypes,
2360 boolean allowBoxing,
2361 boolean useVarargs) {
2362 Symbol bestSoFar = methodNotFound;
2363 for (Scope.Entry e = site.tsym.members().lookup(names.init);
2364 e.scope != null;
2365 e = e.next()) {
2366 final Symbol sym = e.sym;
2367 //- System.out.println(" e " + e.sym);
2368 if (sym.kind == MTH &&
2369 (sym.flags_field & SYNTHETIC) == 0) {
2370 List<Type> oldParams = e.sym.type.hasTag(FORALL) ?
2371 ((ForAll)sym.type).tvars :
2372 List.<Type>nil();
2373 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
2374 types.createMethodTypeWithReturn(sym.type.asMethodType(), site));
2375 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) {
2376 @Override
2377 public Symbol baseSymbol() {
2378 return sym;
2379 }
2380 };
2381 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
2382 newConstr,
2383 bestSoFar,
2384 allowBoxing,
2385 useVarargs,
2386 false);
2387 }
2388 }
2389 return bestSoFar;
2390 }
2394 /** Resolve operator.
2395 * @param pos The position to use for error reporting.
2396 * @param optag The tag of the operation tree.
2397 * @param env The environment current at the operation.
2398 * @param argtypes The types of the operands.
2399 */
2400 Symbol resolveOperator(DiagnosticPosition pos, JCTree.Tag optag,
2401 Env<AttrContext> env, List<Type> argtypes) {
2402 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2403 try {
2404 currentResolutionContext = new MethodResolutionContext();
2405 Name name = treeinfo.operatorName(optag);
2406 env.info.pendingResolutionPhase = currentResolutionContext.step = BASIC;
2407 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
2408 null, false, false, true);
2409 if (boxingEnabled && sym.kind >= WRONG_MTHS)
2410 env.info.pendingResolutionPhase = currentResolutionContext.step = BOX;
2411 sym = findMethod(env, syms.predefClass.type, name, argtypes,
2412 null, true, false, true);
2413 return accessMethod(sym, pos, env.enclClass.sym.type, name,
2414 false, argtypes, null);
2415 }
2416 finally {
2417 currentResolutionContext = prevResolutionContext;
2418 }
2419 }
2421 /** Resolve operator.
2422 * @param pos The position to use for error reporting.
2423 * @param optag The tag of the operation tree.
2424 * @param env The environment current at the operation.
2425 * @param arg The type of the operand.
2426 */
2427 Symbol resolveUnaryOperator(DiagnosticPosition pos, JCTree.Tag optag, Env<AttrContext> env, Type arg) {
2428 return resolveOperator(pos, optag, env, List.of(arg));
2429 }
2431 /** Resolve binary operator.
2432 * @param pos The position to use for error reporting.
2433 * @param optag The tag of the operation tree.
2434 * @param env The environment current at the operation.
2435 * @param left The types of the left operand.
2436 * @param right The types of the right operand.
2437 */
2438 Symbol resolveBinaryOperator(DiagnosticPosition pos,
2439 JCTree.Tag optag,
2440 Env<AttrContext> env,
2441 Type left,
2442 Type right) {
2443 return resolveOperator(pos, optag, env, List.of(left, right));
2444 }
2446 /**
2447 * Resolution of member references is typically done as a single
2448 * overload resolution step, where the argument types A are inferred from
2449 * the target functional descriptor.
2450 *
2451 * If the member reference is a method reference with a type qualifier,
2452 * a two-step lookup process is performed. The first step uses the
2453 * expected argument list A, while the second step discards the first
2454 * type from A (which is treated as a receiver type).
2455 *
2456 * There are two cases in which inference is performed: (i) if the member
2457 * reference is a constructor reference and the qualifier type is raw - in
2458 * which case diamond inference is used to infer a parameterization for the
2459 * type qualifier; (ii) if the member reference is an unbound reference
2460 * where the type qualifier is raw - in that case, during the unbound lookup
2461 * the receiver argument type is used to infer an instantiation for the raw
2462 * qualifier type.
2463 *
2464 * When a multi-step resolution process is exploited, it is an error
2465 * if two candidates are found (ambiguity).
2466 *
2467 * This routine returns a pair (T,S), where S is the member reference symbol,
2468 * and T is the type of the class in which S is defined. This is necessary as
2469 * the type T might be dynamically inferred (i.e. if constructor reference
2470 * has a raw qualifier).
2471 */
2472 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(DiagnosticPosition pos,
2473 Env<AttrContext> env,
2474 JCMemberReference referenceTree,
2475 Type site,
2476 Name name, List<Type> argtypes,
2477 List<Type> typeargtypes,
2478 boolean boxingAllowed) {
2479 MethodResolutionPhase maxPhase = boxingAllowed ? VARARITY : BASIC;
2481 ReferenceLookupHelper boundLookupHelper;
2482 if (!name.equals(names.init)) {
2483 //method reference
2484 boundLookupHelper =
2485 new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2486 } else if (site.hasTag(ARRAY)) {
2487 //array constructor reference
2488 boundLookupHelper =
2489 new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2490 } else {
2491 //class constructor reference
2492 boundLookupHelper =
2493 new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2494 }
2496 //step 1 - bound lookup
2497 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup());
2498 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(), site.tsym, boundLookupHelper);
2500 //step 2 - unbound lookup
2501 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup();
2502 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup());
2503 Symbol unboundSym = lookupMethod(unboundEnv, env.tree.pos(), site.tsym, unboundLookupHelper);
2505 //merge results
2506 Pair<Symbol, ReferenceLookupHelper> res;
2507 if (!lookupSuccess(unboundSym)) {
2508 res = new Pair<Symbol, ReferenceLookupHelper>(boundSym, boundLookupHelper);
2509 env.info.pendingResolutionPhase = boundEnv.info.pendingResolutionPhase;
2510 } else if (lookupSuccess(boundSym)) {
2511 res = new Pair<Symbol, ReferenceLookupHelper>(ambiguityError(boundSym, unboundSym), boundLookupHelper);
2512 env.info.pendingResolutionPhase = boundEnv.info.pendingResolutionPhase;
2513 } else {
2514 res = new Pair<Symbol, ReferenceLookupHelper>(unboundSym, unboundLookupHelper);
2515 env.info.pendingResolutionPhase = unboundEnv.info.pendingResolutionPhase;
2516 }
2518 return res;
2519 }
2520 //private
2521 boolean lookupSuccess(Symbol s) {
2522 return s.kind == MTH || s.kind == AMBIGUOUS;
2523 }
2525 /**
2526 * Helper for defining custom method-like lookup logic; a lookup helper
2527 * provides hooks for (i) the actual lookup logic and (ii) accessing the
2528 * lookup result (this step might result in compiler diagnostics to be generated)
2529 */
2530 abstract class LookupHelper {
2532 /** name of the symbol to lookup */
2533 Name name;
2535 /** location in which the lookup takes place */
2536 Type site;
2538 /** actual types used during the lookup */
2539 List<Type> argtypes;
2541 /** type arguments used during the lookup */
2542 List<Type> typeargtypes;
2544 /** Max overload resolution phase handled by this helper */
2545 MethodResolutionPhase maxPhase;
2547 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2548 this.name = name;
2549 this.site = site;
2550 this.argtypes = argtypes;
2551 this.typeargtypes = typeargtypes;
2552 this.maxPhase = maxPhase;
2553 }
2555 /**
2556 * Should lookup stop at given phase with given result
2557 */
2558 protected boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
2559 return phase.ordinal() > maxPhase.ordinal() ||
2560 sym.kind < ERRONEOUS || sym.kind == AMBIGUOUS;
2561 }
2563 /**
2564 * Search for a symbol under a given overload resolution phase - this method
2565 * is usually called several times, once per each overload resolution phase
2566 */
2567 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase);
2569 /**
2570 * Validate the result of the lookup
2571 */
2572 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym);
2573 }
2575 abstract class BasicLookupHelper extends LookupHelper {
2577 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) {
2578 super(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY);
2579 }
2581 @Override
2582 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2583 if (sym.kind == AMBIGUOUS) {
2584 AmbiguityError a_err = (AmbiguityError)sym;
2585 sym = a_err.mergeAbstracts(site);
2586 }
2587 if (sym.kind >= AMBIGUOUS) {
2588 //if nothing is found return the 'first' error
2589 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes);
2590 }
2591 return sym;
2592 }
2593 }
2595 /**
2596 * Helper class for member reference lookup. A reference lookup helper
2597 * defines the basic logic for member reference lookup; a method gives
2598 * access to an 'unbound' helper used to perform an unbound member
2599 * reference lookup.
2600 */
2601 abstract class ReferenceLookupHelper extends LookupHelper {
2603 /** The member reference tree */
2604 JCMemberReference referenceTree;
2606 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2607 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2608 super(name, site, argtypes, typeargtypes, maxPhase);
2609 this.referenceTree = referenceTree;
2611 }
2613 /**
2614 * Returns an unbound version of this lookup helper. By default, this
2615 * method returns an dummy lookup helper.
2616 */
2617 ReferenceLookupHelper unboundLookup() {
2618 //dummy loopkup helper that always return 'methodNotFound'
2619 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) {
2620 @Override
2621 ReferenceLookupHelper unboundLookup() {
2622 return this;
2623 }
2624 @Override
2625 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2626 return methodNotFound;
2627 }
2628 @Override
2629 ReferenceKind referenceKind(Symbol sym) {
2630 Assert.error();
2631 return null;
2632 }
2633 };
2634 }
2636 /**
2637 * Get the kind of the member reference
2638 */
2639 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym);
2641 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2642 if (sym.kind == AMBIGUOUS) {
2643 AmbiguityError a_err = (AmbiguityError)sym;
2644 sym = a_err.mergeAbstracts(site);
2645 }
2646 //skip error reporting
2647 return sym;
2648 }
2649 }
2651 /**
2652 * Helper class for method reference lookup. The lookup logic is based
2653 * upon Resolve.findMethod; in certain cases, this helper class has a
2654 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper).
2655 * In such cases, non-static lookup results are thrown away.
2656 */
2657 class MethodReferenceLookupHelper extends ReferenceLookupHelper {
2659 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2660 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2661 super(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2662 }
2664 @Override
2665 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2666 return findMethod(env, site, name, argtypes, typeargtypes,
2667 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
2668 }
2670 @Override
2671 ReferenceLookupHelper unboundLookup() {
2672 if (TreeInfo.isStaticSelector(referenceTree.expr, names) &&
2673 argtypes.nonEmpty() &&
2674 types.isSubtypeUnchecked(argtypes.head, site)) {
2675 return new UnboundMethodReferenceLookupHelper(referenceTree, name,
2676 site, argtypes, typeargtypes, maxPhase);
2677 } else {
2678 return super.unboundLookup();
2679 }
2680 }
2682 @Override
2683 ReferenceKind referenceKind(Symbol sym) {
2684 if (sym.isStatic()) {
2685 return ReferenceKind.STATIC;
2686 } else {
2687 Name selName = TreeInfo.name(referenceTree.getQualifierExpression());
2688 return selName != null && selName == names._super ?
2689 ReferenceKind.SUPER :
2690 ReferenceKind.BOUND;
2691 }
2692 }
2693 }
2695 /**
2696 * Helper class for unbound method reference lookup. Essentially the same
2697 * as the basic method reference lookup helper; main difference is that static
2698 * lookup results are thrown away. If qualifier type is raw, an attempt to
2699 * infer a parameterized type is made using the first actual argument (that
2700 * would otherwise be ignored during the lookup).
2701 */
2702 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper {
2704 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2705 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2706 super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase);
2707 Type asSuperSite = types.asSuper(argtypes.head, site.tsym);
2708 if (site.isRaw() && !asSuperSite.isErroneous()) {
2709 this.site = asSuperSite;
2710 }
2711 }
2713 @Override
2714 ReferenceLookupHelper unboundLookup() {
2715 return this;
2716 }
2718 @Override
2719 ReferenceKind referenceKind(Symbol sym) {
2720 return ReferenceKind.UNBOUND;
2721 }
2722 }
2724 /**
2725 * Helper class for array constructor lookup; an array constructor lookup
2726 * is simulated by looking up a method that returns the array type specified
2727 * as qualifier, and that accepts a single int parameter (size of the array).
2728 */
2729 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper {
2731 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
2732 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2733 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
2734 }
2736 @Override
2737 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2738 Scope sc = new Scope(syms.arrayClass);
2739 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym);
2740 arrayConstr.type = new MethodType(List.of(syms.intType), site, List.<Type>nil(), syms.methodClass);
2741 sc.enter(arrayConstr);
2742 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false, false);
2743 }
2745 @Override
2746 ReferenceKind referenceKind(Symbol sym) {
2747 return ReferenceKind.ARRAY_CTOR;
2748 }
2749 }
2751 /**
2752 * Helper class for constructor reference lookup. The lookup logic is based
2753 * upon either Resolve.findMethod or Resolve.findDiamond - depending on
2754 * whether the constructor reference needs diamond inference (this is the case
2755 * if the qualifier type is raw). A special erroneous symbol is returned
2756 * if the lookup returns the constructor of an inner class and there's no
2757 * enclosing instance in scope.
2758 */
2759 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper {
2761 boolean needsInference;
2763 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
2764 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2765 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
2766 if (site.isRaw()) {
2767 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym);
2768 needsInference = true;
2769 }
2770 }
2772 @Override
2773 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2774 Symbol sym = needsInference ?
2775 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) :
2776 findMethod(env, site, name, argtypes, typeargtypes,
2777 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
2778 return sym.kind != MTH ||
2779 site.getEnclosingType().hasTag(NONE) ||
2780 hasEnclosingInstance(env, site) ?
2781 sym : new InvalidSymbolError(Kinds.MISSING_ENCL, sym, null) {
2782 @Override
2783 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
2784 return diags.create(dkind, log.currentSource(), pos,
2785 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType());
2786 }
2787 };
2788 }
2790 @Override
2791 ReferenceKind referenceKind(Symbol sym) {
2792 return site.getEnclosingType().hasTag(NONE) ?
2793 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER;
2794 }
2795 }
2797 /**
2798 * Main overload resolution routine. On each overload resolution step, a
2799 * lookup helper class is used to perform the method/constructor lookup;
2800 * at the end of the lookup, the helper is used to validate the results
2801 * (this last step might trigger overload resolution diagnostics).
2802 */
2803 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, LookupHelper lookupHelper) {
2804 return lookupMethod(env, pos, location, new MethodResolutionContext(), lookupHelper);
2805 }
2807 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location,
2808 MethodResolutionContext resolveContext, LookupHelper lookupHelper) {
2809 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2810 try {
2811 Symbol bestSoFar = methodNotFound;
2812 currentResolutionContext = resolveContext;
2813 for (MethodResolutionPhase phase : methodResolutionSteps) {
2814 if (!phase.isApplicable(boxingEnabled, varargsEnabled) ||
2815 lookupHelper.shouldStop(bestSoFar, phase)) break;
2816 MethodResolutionPhase prevPhase = currentResolutionContext.step;
2817 Symbol prevBest = bestSoFar;
2818 currentResolutionContext.step = phase;
2819 bestSoFar = phase.mergeResults(bestSoFar, lookupHelper.lookup(env, phase));
2820 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase;
2821 }
2822 return lookupHelper.access(env, pos, location, bestSoFar);
2823 } finally {
2824 currentResolutionContext = prevResolutionContext;
2825 }
2826 }
2828 /**
2829 * Resolve `c.name' where name == this or name == super.
2830 * @param pos The position to use for error reporting.
2831 * @param env The environment current at the expression.
2832 * @param c The qualifier.
2833 * @param name The identifier's name.
2834 */
2835 Symbol resolveSelf(DiagnosticPosition pos,
2836 Env<AttrContext> env,
2837 TypeSymbol c,
2838 Name name) {
2839 Env<AttrContext> env1 = env;
2840 boolean staticOnly = false;
2841 while (env1.outer != null) {
2842 if (isStatic(env1)) staticOnly = true;
2843 if (env1.enclClass.sym == c) {
2844 Symbol sym = env1.info.scope.lookup(name).sym;
2845 if (sym != null) {
2846 if (staticOnly) sym = new StaticError(sym);
2847 return accessBase(sym, pos, env.enclClass.sym.type,
2848 name, true);
2849 }
2850 }
2851 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
2852 env1 = env1.outer;
2853 }
2854 if (allowDefaultMethods && c.isInterface() &&
2855 name == names._super && !isStatic(env) &&
2856 types.isDirectSuperInterface(c, env.enclClass.sym)) {
2857 //this might be a default super call if one of the superinterfaces is 'c'
2858 for (Type t : pruneInterfaces(env.enclClass.type)) {
2859 if (t.tsym == c) {
2860 env.info.defaultSuperCallSite = t;
2861 return new VarSymbol(0, names._super,
2862 types.asSuper(env.enclClass.type, c), env.enclClass.sym);
2863 }
2864 }
2865 //find a direct superinterface that is a subtype of 'c'
2866 for (Type i : types.interfaces(env.enclClass.type)) {
2867 if (i.tsym.isSubClass(c, types) && i.tsym != c) {
2868 log.error(pos, "illegal.default.super.call", c,
2869 diags.fragment("redundant.supertype", c, i));
2870 return syms.errSymbol;
2871 }
2872 }
2873 Assert.error();
2874 }
2875 log.error(pos, "not.encl.class", c);
2876 return syms.errSymbol;
2877 }
2878 //where
2879 private List<Type> pruneInterfaces(Type t) {
2880 ListBuffer<Type> result = ListBuffer.lb();
2881 for (Type t1 : types.interfaces(t)) {
2882 boolean shouldAdd = true;
2883 for (Type t2 : types.interfaces(t)) {
2884 if (t1 != t2 && types.isSubtypeNoCapture(t2, t1)) {
2885 shouldAdd = false;
2886 }
2887 }
2888 if (shouldAdd) {
2889 result.append(t1);
2890 }
2891 }
2892 return result.toList();
2893 }
2896 /**
2897 * Resolve `c.this' for an enclosing class c that contains the
2898 * named member.
2899 * @param pos The position to use for error reporting.
2900 * @param env The environment current at the expression.
2901 * @param member The member that must be contained in the result.
2902 */
2903 Symbol resolveSelfContaining(DiagnosticPosition pos,
2904 Env<AttrContext> env,
2905 Symbol member,
2906 boolean isSuperCall) {
2907 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall);
2908 if (sym == null) {
2909 log.error(pos, "encl.class.required", member);
2910 return syms.errSymbol;
2911 } else {
2912 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true);
2913 }
2914 }
2916 boolean hasEnclosingInstance(Env<AttrContext> env, Type type) {
2917 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false);
2918 return encl != null && encl.kind < ERRONEOUS;
2919 }
2921 private Symbol resolveSelfContainingInternal(Env<AttrContext> env,
2922 Symbol member,
2923 boolean isSuperCall) {
2924 Name name = names._this;
2925 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
2926 boolean staticOnly = false;
2927 if (env1 != null) {
2928 while (env1 != null && env1.outer != null) {
2929 if (isStatic(env1)) staticOnly = true;
2930 if (env1.enclClass.sym.isSubClass(member.owner, types)) {
2931 Symbol sym = env1.info.scope.lookup(name).sym;
2932 if (sym != null) {
2933 if (staticOnly) sym = new StaticError(sym);
2934 return sym;
2935 }
2936 }
2937 if ((env1.enclClass.sym.flags() & STATIC) != 0)
2938 staticOnly = true;
2939 env1 = env1.outer;
2940 }
2941 }
2942 return null;
2943 }
2945 /**
2946 * Resolve an appropriate implicit this instance for t's container.
2947 * JLS 8.8.5.1 and 15.9.2
2948 */
2949 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
2950 return resolveImplicitThis(pos, env, t, false);
2951 }
2953 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
2954 Type thisType = (((t.tsym.owner.kind & (MTH|VAR)) != 0)
2955 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
2956 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
2957 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym)
2958 log.error(pos, "cant.ref.before.ctor.called", "this");
2959 return thisType;
2960 }
2962 /* ***************************************************************************
2963 * ResolveError classes, indicating error situations when accessing symbols
2964 ****************************************************************************/
2966 //used by TransTypes when checking target type of synthetic cast
2967 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) {
2968 AccessError error = new AccessError(env, env.enclClass.type, type.tsym);
2969 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null);
2970 }
2971 //where
2972 private void logResolveError(ResolveError error,
2973 DiagnosticPosition pos,
2974 Symbol location,
2975 Type site,
2976 Name name,
2977 List<Type> argtypes,
2978 List<Type> typeargtypes) {
2979 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
2980 pos, location, site, name, argtypes, typeargtypes);
2981 if (d != null) {
2982 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
2983 log.report(d);
2984 }
2985 }
2987 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
2989 public Object methodArguments(List<Type> argtypes) {
2990 if (argtypes == null || argtypes.isEmpty()) {
2991 return noArgs;
2992 } else {
2993 ListBuffer<Object> diagArgs = ListBuffer.lb();
2994 for (Type t : argtypes) {
2995 if (t.hasTag(DEFERRED)) {
2996 diagArgs.append(((DeferredAttr.DeferredType)t).tree);
2997 } else {
2998 diagArgs.append(t);
2999 }
3000 }
3001 return diagArgs;
3002 }
3003 }
3005 /**
3006 * Root class for resolution errors. Subclass of ResolveError
3007 * represent a different kinds of resolution error - as such they must
3008 * specify how they map into concrete compiler diagnostics.
3009 */
3010 abstract class ResolveError extends Symbol {
3012 /** The name of the kind of error, for debugging only. */
3013 final String debugName;
3015 ResolveError(int kind, String debugName) {
3016 super(kind, 0, null, null, null);
3017 this.debugName = debugName;
3018 }
3020 @Override
3021 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
3022 throw new AssertionError();
3023 }
3025 @Override
3026 public String toString() {
3027 return debugName;
3028 }
3030 @Override
3031 public boolean exists() {
3032 return false;
3033 }
3035 /**
3036 * Create an external representation for this erroneous symbol to be
3037 * used during attribution - by default this returns the symbol of a
3038 * brand new error type which stores the original type found
3039 * during resolution.
3040 *
3041 * @param name the name used during resolution
3042 * @param location the location from which the symbol is accessed
3043 */
3044 protected Symbol access(Name name, TypeSymbol location) {
3045 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3046 }
3048 /**
3049 * Create a diagnostic representing this resolution error.
3050 *
3051 * @param dkind The kind of the diagnostic to be created (e.g error).
3052 * @param pos The position to be used for error reporting.
3053 * @param site The original type from where the selection took place.
3054 * @param name The name of the symbol to be resolved.
3055 * @param argtypes The invocation's value arguments,
3056 * if we looked for a method.
3057 * @param typeargtypes The invocation's type arguments,
3058 * if we looked for a method.
3059 */
3060 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3061 DiagnosticPosition pos,
3062 Symbol location,
3063 Type site,
3064 Name name,
3065 List<Type> argtypes,
3066 List<Type> typeargtypes);
3067 }
3069 /**
3070 * This class is the root class of all resolution errors caused by
3071 * an invalid symbol being found during resolution.
3072 */
3073 abstract class InvalidSymbolError extends ResolveError {
3075 /** The invalid symbol found during resolution */
3076 Symbol sym;
3078 InvalidSymbolError(int kind, Symbol sym, String debugName) {
3079 super(kind, debugName);
3080 this.sym = sym;
3081 }
3083 @Override
3084 public boolean exists() {
3085 return true;
3086 }
3088 @Override
3089 public String toString() {
3090 return super.toString() + " wrongSym=" + sym;
3091 }
3093 @Override
3094 public Symbol access(Name name, TypeSymbol location) {
3095 if ((sym.kind & ERRONEOUS) == 0 && (sym.kind & TYP) != 0)
3096 return types.createErrorType(name, location, sym.type).tsym;
3097 else
3098 return sym;
3099 }
3100 }
3102 /**
3103 * InvalidSymbolError error class indicating that a symbol matching a
3104 * given name does not exists in a given site.
3105 */
3106 class SymbolNotFoundError extends ResolveError {
3108 SymbolNotFoundError(int kind) {
3109 super(kind, "symbol not found error");
3110 }
3112 @Override
3113 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3114 DiagnosticPosition pos,
3115 Symbol location,
3116 Type site,
3117 Name name,
3118 List<Type> argtypes,
3119 List<Type> typeargtypes) {
3120 argtypes = argtypes == null ? List.<Type>nil() : argtypes;
3121 typeargtypes = typeargtypes == null ? List.<Type>nil() : typeargtypes;
3122 if (name == names.error)
3123 return null;
3125 if (syms.operatorNames.contains(name)) {
3126 boolean isUnaryOp = argtypes.size() == 1;
3127 String key = argtypes.size() == 1 ?
3128 "operator.cant.be.applied" :
3129 "operator.cant.be.applied.1";
3130 Type first = argtypes.head;
3131 Type second = !isUnaryOp ? argtypes.tail.head : null;
3132 return diags.create(dkind, log.currentSource(), pos,
3133 key, name, first, second);
3134 }
3135 boolean hasLocation = false;
3136 if (location == null) {
3137 location = site.tsym;
3138 }
3139 if (!location.name.isEmpty()) {
3140 if (location.kind == PCK && !site.tsym.exists()) {
3141 return diags.create(dkind, log.currentSource(), pos,
3142 "doesnt.exist", location);
3143 }
3144 hasLocation = !location.name.equals(names._this) &&
3145 !location.name.equals(names._super);
3146 }
3147 boolean isConstructor = kind == ABSENT_MTH && name == names.init;
3148 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : absentKind(kind);
3149 Name idname = isConstructor ? site.tsym.name : name;
3150 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
3151 if (hasLocation) {
3152 return diags.create(dkind, log.currentSource(), pos,
3153 errKey, kindname, idname, //symbol kindname, name
3154 typeargtypes, args(argtypes), //type parameters and arguments (if any)
3155 getLocationDiag(location, site)); //location kindname, type
3156 }
3157 else {
3158 return diags.create(dkind, log.currentSource(), pos,
3159 errKey, kindname, idname, //symbol kindname, name
3160 typeargtypes, args(argtypes)); //type parameters and arguments (if any)
3161 }
3162 }
3163 //where
3164 private Object args(List<Type> args) {
3165 return args.isEmpty() ? args : methodArguments(args);
3166 }
3168 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
3169 String key = "cant.resolve";
3170 String suffix = hasLocation ? ".location" : "";
3171 switch (kindname) {
3172 case METHOD:
3173 case CONSTRUCTOR: {
3174 suffix += ".args";
3175 suffix += hasTypeArgs ? ".params" : "";
3176 }
3177 }
3178 return key + suffix;
3179 }
3180 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
3181 if (location.kind == VAR) {
3182 return diags.fragment("location.1",
3183 kindName(location),
3184 location,
3185 location.type);
3186 } else {
3187 return diags.fragment("location",
3188 typeKindName(site),
3189 site,
3190 null);
3191 }
3192 }
3193 }
3195 /**
3196 * InvalidSymbolError error class indicating that a given symbol
3197 * (either a method, a constructor or an operand) is not applicable
3198 * given an actual arguments/type argument list.
3199 */
3200 class InapplicableSymbolError extends ResolveError {
3202 protected MethodResolutionContext resolveContext;
3204 InapplicableSymbolError(MethodResolutionContext context) {
3205 this(WRONG_MTH, "inapplicable symbol error", context);
3206 }
3208 protected InapplicableSymbolError(int kind, String debugName, MethodResolutionContext context) {
3209 super(kind, debugName);
3210 this.resolveContext = context;
3211 }
3213 @Override
3214 public String toString() {
3215 return super.toString();
3216 }
3218 @Override
3219 public boolean exists() {
3220 return true;
3221 }
3223 @Override
3224 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3225 DiagnosticPosition pos,
3226 Symbol location,
3227 Type site,
3228 Name name,
3229 List<Type> argtypes,
3230 List<Type> typeargtypes) {
3231 if (name == names.error)
3232 return null;
3234 if (syms.operatorNames.contains(name)) {
3235 boolean isUnaryOp = argtypes.size() == 1;
3236 String key = argtypes.size() == 1 ?
3237 "operator.cant.be.applied" :
3238 "operator.cant.be.applied.1";
3239 Type first = argtypes.head;
3240 Type second = !isUnaryOp ? argtypes.tail.head : null;
3241 return diags.create(dkind, log.currentSource(), pos,
3242 key, name, first, second);
3243 }
3244 else {
3245 Candidate c = errCandidate();
3246 Symbol ws = c.sym.asMemberOf(site, types);
3247 return diags.create(dkind, log.currentSource(), pos,
3248 "cant.apply.symbol",
3249 kindName(ws),
3250 ws.name == names.init ? ws.owner.name : ws.name,
3251 methodArguments(ws.type.getParameterTypes()),
3252 methodArguments(argtypes),
3253 kindName(ws.owner),
3254 ws.owner.type,
3255 c.details);
3256 }
3257 }
3259 @Override
3260 public Symbol access(Name name, TypeSymbol location) {
3261 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3262 }
3264 private Candidate errCandidate() {
3265 Candidate bestSoFar = null;
3266 for (Candidate c : resolveContext.candidates) {
3267 if (c.isApplicable()) continue;
3268 bestSoFar = c;
3269 }
3270 Assert.checkNonNull(bestSoFar);
3271 return bestSoFar;
3272 }
3273 }
3275 /**
3276 * ResolveError error class indicating that a set of symbols
3277 * (either methods, constructors or operands) is not applicable
3278 * given an actual arguments/type argument list.
3279 */
3280 class InapplicableSymbolsError extends InapplicableSymbolError {
3282 InapplicableSymbolsError(MethodResolutionContext context) {
3283 super(WRONG_MTHS, "inapplicable symbols", context);
3284 }
3286 @Override
3287 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3288 DiagnosticPosition pos,
3289 Symbol location,
3290 Type site,
3291 Name name,
3292 List<Type> argtypes,
3293 List<Type> typeargtypes) {
3294 if (!resolveContext.candidates.isEmpty()) {
3295 JCDiagnostic err = diags.create(dkind,
3296 log.currentSource(),
3297 pos,
3298 "cant.apply.symbols",
3299 name == names.init ? KindName.CONSTRUCTOR : absentKind(kind),
3300 name == names.init ? site.tsym.name : name,
3301 methodArguments(argtypes));
3302 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(site));
3303 } else {
3304 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
3305 location, site, name, argtypes, typeargtypes);
3306 }
3307 }
3309 //where
3310 List<JCDiagnostic> candidateDetails(Type site) {
3311 Map<Symbol, JCDiagnostic> details = new LinkedHashMap<Symbol, JCDiagnostic>();
3312 for (Candidate c : resolveContext.candidates) {
3313 if (c.isApplicable()) continue;
3314 JCDiagnostic detailDiag = diags.fragment("inapplicable.method",
3315 Kinds.kindName(c.sym),
3316 c.sym.location(site, types),
3317 c.sym.asMemberOf(site, types),
3318 c.details);
3319 details.put(c.sym, detailDiag);
3320 }
3321 return List.from(details.values());
3322 }
3323 }
3325 /**
3326 * An InvalidSymbolError error class indicating that a symbol is not
3327 * accessible from a given site
3328 */
3329 class AccessError extends InvalidSymbolError {
3331 private Env<AttrContext> env;
3332 private Type site;
3334 AccessError(Symbol sym) {
3335 this(null, null, sym);
3336 }
3338 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
3339 super(HIDDEN, sym, "access error");
3340 this.env = env;
3341 this.site = site;
3342 if (debugResolve)
3343 log.error("proc.messager", sym + " @ " + site + " is inaccessible.");
3344 }
3346 @Override
3347 public boolean exists() {
3348 return false;
3349 }
3351 @Override
3352 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3353 DiagnosticPosition pos,
3354 Symbol location,
3355 Type site,
3356 Name name,
3357 List<Type> argtypes,
3358 List<Type> typeargtypes) {
3359 if (sym.owner.type.hasTag(ERROR))
3360 return null;
3362 if (sym.name == names.init && sym.owner != site.tsym) {
3363 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
3364 pos, location, site, name, argtypes, typeargtypes);
3365 }
3366 else if ((sym.flags() & PUBLIC) != 0
3367 || (env != null && this.site != null
3368 && !isAccessible(env, this.site))) {
3369 return diags.create(dkind, log.currentSource(),
3370 pos, "not.def.access.class.intf.cant.access",
3371 sym, sym.location());
3372 }
3373 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
3374 return diags.create(dkind, log.currentSource(),
3375 pos, "report.access", sym,
3376 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
3377 sym.location());
3378 }
3379 else {
3380 return diags.create(dkind, log.currentSource(),
3381 pos, "not.def.public.cant.access", sym, sym.location());
3382 }
3383 }
3384 }
3386 /**
3387 * InvalidSymbolError error class indicating that an instance member
3388 * has erroneously been accessed from a static context.
3389 */
3390 class StaticError extends InvalidSymbolError {
3392 StaticError(Symbol sym) {
3393 super(STATICERR, sym, "static error");
3394 }
3396 @Override
3397 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3398 DiagnosticPosition pos,
3399 Symbol location,
3400 Type site,
3401 Name name,
3402 List<Type> argtypes,
3403 List<Type> typeargtypes) {
3404 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS))
3405 ? types.erasure(sym.type).tsym
3406 : sym);
3407 return diags.create(dkind, log.currentSource(), pos,
3408 "non-static.cant.be.ref", kindName(sym), errSym);
3409 }
3410 }
3412 /**
3413 * InvalidSymbolError error class indicating that a pair of symbols
3414 * (either methods, constructors or operands) are ambiguous
3415 * given an actual arguments/type argument list.
3416 */
3417 class AmbiguityError extends ResolveError {
3419 /** The other maximally specific symbol */
3420 List<Symbol> ambiguousSyms = List.nil();
3422 @Override
3423 public boolean exists() {
3424 return true;
3425 }
3427 AmbiguityError(Symbol sym1, Symbol sym2) {
3428 super(AMBIGUOUS, "ambiguity error");
3429 ambiguousSyms = flatten(sym2).appendList(flatten(sym1));
3430 }
3432 private List<Symbol> flatten(Symbol sym) {
3433 if (sym.kind == AMBIGUOUS) {
3434 return ((AmbiguityError)sym).ambiguousSyms;
3435 } else {
3436 return List.of(sym);
3437 }
3438 }
3440 AmbiguityError addAmbiguousSymbol(Symbol s) {
3441 ambiguousSyms = ambiguousSyms.prepend(s);
3442 return this;
3443 }
3445 @Override
3446 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3447 DiagnosticPosition pos,
3448 Symbol location,
3449 Type site,
3450 Name name,
3451 List<Type> argtypes,
3452 List<Type> typeargtypes) {
3453 List<Symbol> diagSyms = ambiguousSyms.reverse();
3454 Symbol s1 = diagSyms.head;
3455 Symbol s2 = diagSyms.tail.head;
3456 Name sname = s1.name;
3457 if (sname == names.init) sname = s1.owner.name;
3458 return diags.create(dkind, log.currentSource(),
3459 pos, "ref.ambiguous", sname,
3460 kindName(s1),
3461 s1,
3462 s1.location(site, types),
3463 kindName(s2),
3464 s2,
3465 s2.location(site, types));
3466 }
3468 /**
3469 * If multiple applicable methods are found during overload and none of them
3470 * is more specific than the others, attempt to merge their signatures.
3471 */
3472 Symbol mergeAbstracts(Type site) {
3473 Symbol fst = ambiguousSyms.last();
3474 Symbol res = fst;
3475 for (Symbol s : ambiguousSyms.reverse()) {
3476 Type mt1 = types.memberType(site, res);
3477 Type mt2 = types.memberType(site, s);
3478 if ((s.flags() & ABSTRACT) == 0 ||
3479 !types.overrideEquivalent(mt1, mt2) ||
3480 !types.isSameTypes(fst.erasure(types).getParameterTypes(),
3481 s.erasure(types).getParameterTypes())) {
3482 //ambiguity cannot be resolved
3483 return this;
3484 } else {
3485 Type mst = mostSpecificReturnType(mt1, mt2);
3486 if (mst == null) {
3487 // Theoretically, this can't happen, but it is possible
3488 // due to error recovery or mixing incompatible class files
3489 return this;
3490 }
3491 Symbol mostSpecific = mst == mt1 ? res : s;
3492 List<Type> allThrown = chk.intersect(mt1.getThrownTypes(), mt2.getThrownTypes());
3493 Type newSig = types.createMethodTypeWithThrown(mostSpecific.type, allThrown);
3494 res = new MethodSymbol(
3495 mostSpecific.flags(),
3496 mostSpecific.name,
3497 newSig,
3498 mostSpecific.owner);
3499 }
3500 }
3501 return res;
3502 }
3504 @Override
3505 protected Symbol access(Name name, TypeSymbol location) {
3506 Symbol firstAmbiguity = ambiguousSyms.last();
3507 return firstAmbiguity.kind == TYP ?
3508 types.createErrorType(name, location, firstAmbiguity.type).tsym :
3509 firstAmbiguity;
3510 }
3511 }
3513 class BadVarargsMethod extends ResolveError {
3515 ResolveError delegatedError;
3517 BadVarargsMethod(ResolveError delegatedError) {
3518 super(delegatedError.kind, "badVarargs");
3519 this.delegatedError = delegatedError;
3520 }
3522 @Override
3523 protected Symbol access(Name name, TypeSymbol location) {
3524 return delegatedError.access(name, location);
3525 }
3527 @Override
3528 public boolean exists() {
3529 return true;
3530 }
3532 @Override
3533 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
3534 return delegatedError.getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes);
3535 }
3536 }
3538 enum MethodResolutionPhase {
3539 BASIC(false, false),
3540 BOX(true, false),
3541 VARARITY(true, true) {
3542 @Override
3543 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) {
3544 switch (sym.kind) {
3545 case WRONG_MTH:
3546 return (bestSoFar.kind == WRONG_MTH || bestSoFar.kind == WRONG_MTHS) ?
3547 bestSoFar :
3548 sym;
3549 case ABSENT_MTH:
3550 return bestSoFar;
3551 default:
3552 return sym;
3553 }
3554 }
3555 };
3557 final boolean isBoxingRequired;
3558 final boolean isVarargsRequired;
3560 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
3561 this.isBoxingRequired = isBoxingRequired;
3562 this.isVarargsRequired = isVarargsRequired;
3563 }
3565 public boolean isBoxingRequired() {
3566 return isBoxingRequired;
3567 }
3569 public boolean isVarargsRequired() {
3570 return isVarargsRequired;
3571 }
3573 public boolean isApplicable(boolean boxingEnabled, boolean varargsEnabled) {
3574 return (varargsEnabled || !isVarargsRequired) &&
3575 (boxingEnabled || !isBoxingRequired);
3576 }
3578 public Symbol mergeResults(Symbol prev, Symbol sym) {
3579 return sym;
3580 }
3581 }
3583 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
3585 /**
3586 * A resolution context is used to keep track of intermediate results of
3587 * overload resolution, such as list of method that are not applicable
3588 * (used to generate more precise diagnostics) and so on. Resolution contexts
3589 * can be nested - this means that when each overload resolution routine should
3590 * work within the resolution context it created.
3591 */
3592 class MethodResolutionContext {
3594 private List<Candidate> candidates = List.nil();
3596 MethodResolutionPhase step = null;
3598 private boolean internalResolution = false;
3599 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE;
3601 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) {
3602 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null);
3603 candidates = candidates.append(c);
3604 }
3606 void addApplicableCandidate(Symbol sym, Type mtype) {
3607 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype);
3608 candidates = candidates.append(c);
3609 }
3611 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext, ResultInfo pendingResult, Warner warn) {
3612 return deferredAttr.new DeferredAttrContext(attrMode, sym, step, inferenceContext, pendingResult != null ? pendingResult.checkContext.deferredAttrContext() : deferredAttr.emptyDeferredAttrContext, warn);
3613 }
3615 /**
3616 * This class represents an overload resolution candidate. There are two
3617 * kinds of candidates: applicable methods and inapplicable methods;
3618 * applicable methods have a pointer to the instantiated method type,
3619 * while inapplicable candidates contain further details about the
3620 * reason why the method has been considered inapplicable.
3621 */
3622 @SuppressWarnings("overrides")
3623 class Candidate {
3625 final MethodResolutionPhase step;
3626 final Symbol sym;
3627 final JCDiagnostic details;
3628 final Type mtype;
3630 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) {
3631 this.step = step;
3632 this.sym = sym;
3633 this.details = details;
3634 this.mtype = mtype;
3635 }
3637 @Override
3638 public boolean equals(Object o) {
3639 if (o instanceof Candidate) {
3640 Symbol s1 = this.sym;
3641 Symbol s2 = ((Candidate)o).sym;
3642 if ((s1 != s2 &&
3643 (s1.overrides(s2, s1.owner.type.tsym, types, false) ||
3644 (s2.overrides(s1, s2.owner.type.tsym, types, false)))) ||
3645 ((s1.isConstructor() || s2.isConstructor()) && s1.owner != s2.owner))
3646 return true;
3647 }
3648 return false;
3649 }
3651 boolean isApplicable() {
3652 return mtype != null;
3653 }
3654 }
3656 DeferredAttr.AttrMode attrMode() {
3657 return attrMode;
3658 }
3660 boolean internal() {
3661 return internalResolution;
3662 }
3663 }
3665 MethodResolutionContext currentResolutionContext = null;
3666 }
