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src/share/classes/com/sun/tools/javac/comp/Resolve.java@2eca84194807
src/share/classes/com/sun/tools/javac/comp/Resolve.java
Tue, 25 Sep 2012 11:55:34 +0100
- author
- mcimadamore
- date
- Tue, 25 Sep 2012 11:55:34 +0100
- changeset 1337
- 2eca84194807
- parent 1335
- 99983a4a593b
- child 1338
- ad2ca2a4ab5e
- permissions
- -rw-r--r--
7175433: Inference cleanup: add helper class to handle inference variables
Summary: Add class to handle inference variables instantiation and associated info
Reviewed-by: jjg, dlsmith
1 /*
2 * Copyright (c) 1999, 2012, 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.Type.*;
31 import com.sun.tools.javac.code.Symbol.*;
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.Infer.InferenceContext;
35 import com.sun.tools.javac.comp.Infer.InferenceContext.FreeTypeListener;
36 import com.sun.tools.javac.comp.Resolve.MethodResolutionContext.Candidate;
37 import com.sun.tools.javac.jvm.*;
38 import com.sun.tools.javac.tree.*;
39 import com.sun.tools.javac.tree.JCTree.*;
40 import com.sun.tools.javac.util.*;
41 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
42 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
43 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
45 import java.util.ArrayList;
46 import java.util.Arrays;
47 import java.util.Collection;
48 import java.util.EnumMap;
49 import java.util.EnumSet;
50 import java.util.HashSet;
51 import java.util.Map;
52 import java.util.Set;
54 import javax.lang.model.element.ElementVisitor;
56 import static com.sun.tools.javac.code.Flags.*;
57 import static com.sun.tools.javac.code.Flags.BLOCK;
58 import static com.sun.tools.javac.code.Kinds.*;
59 import static com.sun.tools.javac.code.Kinds.ERRONEOUS;
60 import static com.sun.tools.javac.code.TypeTags.*;
61 import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*;
62 import static com.sun.tools.javac.tree.JCTree.Tag.*;
63 import java.util.Iterator;
65 /** Helper class for name resolution, used mostly by the attribution phase.
66 *
67 * <p><b>This is NOT part of any supported API.
68 * If you write code that depends on this, you do so at your own risk.
69 * This code and its internal interfaces are subject to change or
70 * deletion without notice.</b>
71 */
72 public class Resolve {
73 protected static final Context.Key<Resolve> resolveKey =
74 new Context.Key<Resolve>();
76 Names names;
77 Log log;
78 Symtab syms;
79 Attr attr;
80 Check chk;
81 Infer infer;
82 ClassReader reader;
83 TreeInfo treeinfo;
84 Types types;
85 JCDiagnostic.Factory diags;
86 public final boolean boxingEnabled; // = source.allowBoxing();
87 public final boolean varargsEnabled; // = source.allowVarargs();
88 public final boolean allowMethodHandles;
89 private final boolean debugResolve;
90 final EnumSet<VerboseResolutionMode> verboseResolutionMode;
92 Scope polymorphicSignatureScope;
94 protected Resolve(Context context) {
95 context.put(resolveKey, this);
96 syms = Symtab.instance(context);
98 varNotFound = new
99 SymbolNotFoundError(ABSENT_VAR);
100 wrongMethod = new
101 InapplicableSymbolError();
102 wrongMethods = new
103 InapplicableSymbolsError();
104 methodNotFound = new
105 SymbolNotFoundError(ABSENT_MTH);
106 typeNotFound = new
107 SymbolNotFoundError(ABSENT_TYP);
109 names = Names.instance(context);
110 log = Log.instance(context);
111 attr = Attr.instance(context);
112 chk = Check.instance(context);
113 infer = Infer.instance(context);
114 reader = ClassReader.instance(context);
115 treeinfo = TreeInfo.instance(context);
116 types = Types.instance(context);
117 diags = JCDiagnostic.Factory.instance(context);
118 Source source = Source.instance(context);
119 boxingEnabled = source.allowBoxing();
120 varargsEnabled = source.allowVarargs();
121 Options options = Options.instance(context);
122 debugResolve = options.isSet("debugresolve");
123 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
124 Target target = Target.instance(context);
125 allowMethodHandles = target.hasMethodHandles();
126 polymorphicSignatureScope = new Scope(syms.noSymbol);
128 inapplicableMethodException = new InapplicableMethodException(diags);
129 }
131 /** error symbols, which are returned when resolution fails
132 */
133 private final SymbolNotFoundError varNotFound;
134 private final InapplicableSymbolError wrongMethod;
135 private final InapplicableSymbolsError wrongMethods;
136 private final SymbolNotFoundError methodNotFound;
137 private final SymbolNotFoundError typeNotFound;
139 public static Resolve instance(Context context) {
140 Resolve instance = context.get(resolveKey);
141 if (instance == null)
142 instance = new Resolve(context);
143 return instance;
144 }
146 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support">
147 enum VerboseResolutionMode {
148 SUCCESS("success"),
149 FAILURE("failure"),
150 APPLICABLE("applicable"),
151 INAPPLICABLE("inapplicable"),
152 DEFERRED_INST("deferred-inference"),
153 PREDEF("predef"),
154 OBJECT_INIT("object-init"),
155 INTERNAL("internal");
157 String opt;
159 private VerboseResolutionMode(String opt) {
160 this.opt = opt;
161 }
163 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) {
164 String s = opts.get("verboseResolution");
165 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class);
166 if (s == null) return res;
167 if (s.contains("all")) {
168 res = EnumSet.allOf(VerboseResolutionMode.class);
169 }
170 Collection<String> args = Arrays.asList(s.split(","));
171 for (VerboseResolutionMode mode : values()) {
172 if (args.contains(mode.opt)) {
173 res.add(mode);
174 } else if (args.contains("-" + mode.opt)) {
175 res.remove(mode);
176 }
177 }
178 return res;
179 }
180 }
182 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site,
183 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) {
184 boolean success = bestSoFar.kind < ERRONEOUS;
186 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) {
187 return;
188 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) {
189 return;
190 }
192 if (bestSoFar.name == names.init &&
193 bestSoFar.owner == syms.objectType.tsym &&
194 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) {
195 return; //skip diags for Object constructor resolution
196 } else if (site == syms.predefClass.type &&
197 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) {
198 return; //skip spurious diags for predef symbols (i.e. operators)
199 } else if (currentResolutionContext.internalResolution &&
200 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) {
201 return;
202 }
204 int pos = 0;
205 int mostSpecificPos = -1;
206 ListBuffer<JCDiagnostic> subDiags = ListBuffer.lb();
207 for (Candidate c : currentResolutionContext.candidates) {
208 if (currentResolutionContext.step != c.step ||
209 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) ||
210 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) {
211 continue;
212 } else {
213 subDiags.append(c.isApplicable() ?
214 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) :
215 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details));
216 if (c.sym == bestSoFar)
217 mostSpecificPos = pos;
218 pos++;
219 }
220 }
221 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1";
222 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name,
223 site.tsym, mostSpecificPos, currentResolutionContext.step,
224 methodArguments(argtypes), methodArguments(typeargtypes));
225 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
226 log.report(d);
227 }
229 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) {
230 JCDiagnostic subDiag = null;
231 if (sym.type.tag == FORALL) {
232 subDiag = diags.fragment("partial.inst.sig", inst);
233 }
235 String key = subDiag == null ?
236 "applicable.method.found" :
237 "applicable.method.found.1";
239 return diags.fragment(key, pos, sym, subDiag);
240 }
242 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) {
243 return diags.fragment("not.applicable.method.found", pos, sym, subDiag);
244 }
245 // </editor-fold>
247 /* ************************************************************************
248 * Identifier resolution
249 *************************************************************************/
251 /** An environment is "static" if its static level is greater than
252 * the one of its outer environment
253 */
254 static boolean isStatic(Env<AttrContext> env) {
255 return env.info.staticLevel > env.outer.info.staticLevel;
256 }
258 /** An environment is an "initializer" if it is a constructor or
259 * an instance initializer.
260 */
261 static boolean isInitializer(Env<AttrContext> env) {
262 Symbol owner = env.info.scope.owner;
263 return owner.isConstructor() ||
264 owner.owner.kind == TYP &&
265 (owner.kind == VAR ||
266 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
267 (owner.flags() & STATIC) == 0;
268 }
270 /** Is class accessible in given evironment?
271 * @param env The current environment.
272 * @param c The class whose accessibility is checked.
273 */
274 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
275 return isAccessible(env, c, false);
276 }
278 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) {
279 boolean isAccessible = false;
280 switch ((short)(c.flags() & AccessFlags)) {
281 case PRIVATE:
282 isAccessible =
283 env.enclClass.sym.outermostClass() ==
284 c.owner.outermostClass();
285 break;
286 case 0:
287 isAccessible =
288 env.toplevel.packge == c.owner // fast special case
289 ||
290 env.toplevel.packge == c.packge()
291 ||
292 // Hack: this case is added since synthesized default constructors
293 // of anonymous classes should be allowed to access
294 // classes which would be inaccessible otherwise.
295 env.enclMethod != null &&
296 (env.enclMethod.mods.flags & ANONCONSTR) != 0;
297 break;
298 default: // error recovery
299 case PUBLIC:
300 isAccessible = true;
301 break;
302 case PROTECTED:
303 isAccessible =
304 env.toplevel.packge == c.owner // fast special case
305 ||
306 env.toplevel.packge == c.packge()
307 ||
308 isInnerSubClass(env.enclClass.sym, c.owner);
309 break;
310 }
311 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
312 isAccessible :
313 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
314 }
315 //where
316 /** Is given class a subclass of given base class, or an inner class
317 * of a subclass?
318 * Return null if no such class exists.
319 * @param c The class which is the subclass or is contained in it.
320 * @param base The base class
321 */
322 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
323 while (c != null && !c.isSubClass(base, types)) {
324 c = c.owner.enclClass();
325 }
326 return c != null;
327 }
329 boolean isAccessible(Env<AttrContext> env, Type t) {
330 return isAccessible(env, t, false);
331 }
333 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) {
334 return (t.tag == ARRAY)
335 ? isAccessible(env, types.elemtype(t))
336 : isAccessible(env, t.tsym, checkInner);
337 }
339 /** Is symbol accessible as a member of given type in given evironment?
340 * @param env The current environment.
341 * @param site The type of which the tested symbol is regarded
342 * as a member.
343 * @param sym The symbol.
344 */
345 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
346 return isAccessible(env, site, sym, false);
347 }
348 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) {
349 if (sym.name == names.init && sym.owner != site.tsym) return false;
350 switch ((short)(sym.flags() & AccessFlags)) {
351 case PRIVATE:
352 return
353 (env.enclClass.sym == sym.owner // fast special case
354 ||
355 env.enclClass.sym.outermostClass() ==
356 sym.owner.outermostClass())
357 &&
358 sym.isInheritedIn(site.tsym, types);
359 case 0:
360 return
361 (env.toplevel.packge == sym.owner.owner // fast special case
362 ||
363 env.toplevel.packge == sym.packge())
364 &&
365 isAccessible(env, site, checkInner)
366 &&
367 sym.isInheritedIn(site.tsym, types)
368 &&
369 notOverriddenIn(site, sym);
370 case PROTECTED:
371 return
372 (env.toplevel.packge == sym.owner.owner // fast special case
373 ||
374 env.toplevel.packge == sym.packge()
375 ||
376 isProtectedAccessible(sym, env.enclClass.sym, site)
377 ||
378 // OK to select instance method or field from 'super' or type name
379 // (but type names should be disallowed elsewhere!)
380 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
381 &&
382 isAccessible(env, site, checkInner)
383 &&
384 notOverriddenIn(site, sym);
385 default: // this case includes erroneous combinations as well
386 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
387 }
388 }
389 //where
390 /* `sym' is accessible only if not overridden by
391 * another symbol which is a member of `site'
392 * (because, if it is overridden, `sym' is not strictly
393 * speaking a member of `site'). A polymorphic signature method
394 * cannot be overridden (e.g. MH.invokeExact(Object[])).
395 */
396 private boolean notOverriddenIn(Type site, Symbol sym) {
397 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
398 return true;
399 else {
400 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
401 return (s2 == null || s2 == sym || sym.owner == s2.owner ||
402 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
403 }
404 }
405 //where
406 /** Is given protected symbol accessible if it is selected from given site
407 * and the selection takes place in given class?
408 * @param sym The symbol with protected access
409 * @param c The class where the access takes place
410 * @site The type of the qualifier
411 */
412 private
413 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
414 while (c != null &&
415 !(c.isSubClass(sym.owner, types) &&
416 (c.flags() & INTERFACE) == 0 &&
417 // In JLS 2e 6.6.2.1, the subclass restriction applies
418 // only to instance fields and methods -- types are excluded
419 // regardless of whether they are declared 'static' or not.
420 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || site.tsym.isSubClass(c, types))))
421 c = c.owner.enclClass();
422 return c != null;
423 }
425 /** Try to instantiate the type of a method so that it fits
426 * given type arguments and argument types. If succesful, return
427 * the method's instantiated type, else return null.
428 * The instantiation will take into account an additional leading
429 * formal parameter if the method is an instance method seen as a member
430 * of un underdetermined site In this case, we treat site as an additional
431 * parameter and the parameters of the class containing the method as
432 * additional type variables that get instantiated.
433 *
434 * @param env The current environment
435 * @param site The type of which the method is a member.
436 * @param m The method symbol.
437 * @param argtypes The invocation's given value arguments.
438 * @param typeargtypes The invocation's given type arguments.
439 * @param allowBoxing Allow boxing conversions of arguments.
440 * @param useVarargs Box trailing arguments into an array for varargs.
441 */
442 Type rawInstantiate(Env<AttrContext> env,
443 Type site,
444 Symbol m,
445 ResultInfo resultInfo,
446 List<Type> argtypes,
447 List<Type> typeargtypes,
448 boolean allowBoxing,
449 boolean useVarargs,
450 Warner warn)
451 throws Infer.InferenceException {
452 if (useVarargs && (m.flags() & VARARGS) == 0)
453 throw inapplicableMethodException.setMessage();
454 Type mt = types.memberType(site, m);
456 // tvars is the list of formal type variables for which type arguments
457 // need to inferred.
458 List<Type> tvars = List.nil();
459 if (typeargtypes == null) typeargtypes = List.nil();
460 if (mt.tag != FORALL && typeargtypes.nonEmpty()) {
461 // This is not a polymorphic method, but typeargs are supplied
462 // which is fine, see JLS 15.12.2.1
463 } else if (mt.tag == FORALL && typeargtypes.nonEmpty()) {
464 ForAll pmt = (ForAll) mt;
465 if (typeargtypes.length() != pmt.tvars.length())
466 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args
467 // Check type arguments are within bounds
468 List<Type> formals = pmt.tvars;
469 List<Type> actuals = typeargtypes;
470 while (formals.nonEmpty() && actuals.nonEmpty()) {
471 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
472 pmt.tvars, typeargtypes);
473 for (; bounds.nonEmpty(); bounds = bounds.tail)
474 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn))
475 throw inapplicableMethodException.setMessage("explicit.param.do.not.conform.to.bounds",actuals.head, bounds);
476 formals = formals.tail;
477 actuals = actuals.tail;
478 }
479 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
480 } else if (mt.tag == FORALL) {
481 ForAll pmt = (ForAll) mt;
482 List<Type> tvars1 = types.newInstances(pmt.tvars);
483 tvars = tvars.appendList(tvars1);
484 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
485 }
487 // find out whether we need to go the slow route via infer
488 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/
489 for (List<Type> l = argtypes;
490 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
491 l = l.tail) {
492 if (l.head.tag == FORALL) instNeeded = true;
493 }
495 if (instNeeded)
496 return infer.instantiateMethod(env,
497 tvars,
498 (MethodType)mt,
499 resultInfo,
500 m,
501 argtypes,
502 allowBoxing,
503 useVarargs,
504 warn);
506 checkRawArgumentsAcceptable(env, argtypes, mt.getParameterTypes(),
507 allowBoxing, useVarargs, warn);
508 return mt;
509 }
511 /** Same but returns null instead throwing a NoInstanceException
512 */
513 Type instantiate(Env<AttrContext> env,
514 Type site,
515 Symbol m,
516 ResultInfo resultInfo,
517 List<Type> argtypes,
518 List<Type> typeargtypes,
519 boolean allowBoxing,
520 boolean useVarargs,
521 Warner warn) {
522 try {
523 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
524 allowBoxing, useVarargs, warn);
525 } catch (InapplicableMethodException ex) {
526 return null;
527 }
528 }
530 /** Check if a parameter list accepts a list of args.
531 */
532 boolean argumentsAcceptable(Env<AttrContext> env,
533 List<Type> argtypes,
534 List<Type> formals,
535 boolean allowBoxing,
536 boolean useVarargs,
537 Warner warn) {
538 try {
539 checkRawArgumentsAcceptable(env, argtypes, formals, allowBoxing, useVarargs, warn);
540 return true;
541 } catch (InapplicableMethodException ex) {
542 return false;
543 }
544 }
545 /**
546 * A check handler is used by the main method applicability routine in order
547 * to handle specific method applicability failures. It is assumed that a class
548 * implementing this interface should throw exceptions that are a subtype of
549 * InapplicableMethodException (see below). Such exception will terminate the
550 * method applicability check and propagate important info outwards (for the
551 * purpose of generating better diagnostics).
552 */
553 interface MethodCheckHandler {
554 /* The number of actuals and formals differ */
555 InapplicableMethodException arityMismatch();
556 /* An actual argument type does not conform to the corresponding formal type */
557 InapplicableMethodException argumentMismatch(boolean varargs, JCDiagnostic details);
558 /* The element type of a varargs is not accessible in the current context */
559 InapplicableMethodException inaccessibleVarargs(Symbol location, Type expected);
560 }
562 /**
563 * Basic method check handler used within Resolve - all methods end up
564 * throwing InapplicableMethodException; a diagnostic fragment that describes
565 * the cause as to why the method is not applicable is set on the exception
566 * before it is thrown.
567 */
568 MethodCheckHandler resolveHandler = new MethodCheckHandler() {
569 public InapplicableMethodException arityMismatch() {
570 return inapplicableMethodException.setMessage("arg.length.mismatch");
571 }
572 public InapplicableMethodException argumentMismatch(boolean varargs, JCDiagnostic details) {
573 String key = varargs ?
574 "varargs.argument.mismatch" :
575 "no.conforming.assignment.exists";
576 return inapplicableMethodException.setMessage(key,
577 details);
578 }
579 public InapplicableMethodException inaccessibleVarargs(Symbol location, Type expected) {
580 return inapplicableMethodException.setMessage("inaccessible.varargs.type",
581 expected, Kinds.kindName(location), location);
582 }
583 };
585 void checkRawArgumentsAcceptable(Env<AttrContext> env,
586 List<Type> argtypes,
587 List<Type> formals,
588 boolean allowBoxing,
589 boolean useVarargs,
590 Warner warn) {
591 checkRawArgumentsAcceptable(env, infer.emptyContext, argtypes, formals,
592 allowBoxing, useVarargs, warn, resolveHandler);
593 }
595 /**
596 * Main method applicability routine. Given a list of actual types A,
597 * a list of formal types F, determines whether the types in A are
598 * compatible (by method invocation conversion) with the types in F.
599 *
600 * Since this routine is shared between overload resolution and method
601 * type-inference, it is crucial that actual types are converted to the
602 * corresponding 'undet' form (i.e. where inference variables are replaced
603 * with undetvars) so that constraints can be propagated and collected.
604 *
605 * Moreover, if one or more types in A is a poly type, this routine calls
606 * Infer.instantiateArg in order to complete the poly type (this might involve
607 * deferred attribution).
608 *
609 * A method check handler (see above) is used in order to report errors.
610 */
611 void checkRawArgumentsAcceptable(final Env<AttrContext> env,
612 final Infer.InferenceContext inferenceContext,
613 List<Type> argtypes,
614 List<Type> formals,
615 boolean allowBoxing,
616 boolean useVarargs,
617 Warner warn,
618 MethodCheckHandler handler) {
619 Type varargsFormal = useVarargs ? formals.last() : null;
620 ListBuffer<Type> checkedArgs = ListBuffer.lb();
622 if (varargsFormal == null &&
623 argtypes.size() != formals.size()) {
624 throw handler.arityMismatch(); // not enough args
625 }
627 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
628 ResultInfo resultInfo = methodCheckResult(formals.head, allowBoxing, false, inferenceContext, handler, warn);
629 checkedArgs.append(resultInfo.check(env.tree.pos(), argtypes.head));
630 argtypes = argtypes.tail;
631 formals = formals.tail;
632 }
634 if (formals.head != varargsFormal) {
635 throw handler.arityMismatch(); // not enough args
636 }
638 if (useVarargs) {
639 //note: if applicability check is triggered by most specific test,
640 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
641 Type elt = types.elemtype(varargsFormal);
642 while (argtypes.nonEmpty()) {
643 ResultInfo resultInfo = methodCheckResult(elt, allowBoxing, true, inferenceContext, handler, warn);
644 checkedArgs.append(resultInfo.check(env.tree.pos(), argtypes.head));
645 argtypes = argtypes.tail;
646 }
647 //check varargs element type accessibility
648 varargsAccessible(env, elt, handler, inferenceContext);
649 }
650 }
652 void varargsAccessible(final Env<AttrContext> env, final Type t, final Resolve.MethodCheckHandler handler, final InferenceContext inferenceContext) {
653 if (inferenceContext.free(t)) {
654 inferenceContext.addFreeTypeListener(List.of(t), new FreeTypeListener() {
655 @Override
656 public void typesInferred(InferenceContext inferenceContext) {
657 varargsAccessible(env, inferenceContext.asInstType(t, types), handler, inferenceContext);
658 }
659 });
660 } else {
661 if (!isAccessible(env, t)) {
662 Symbol location = env.enclClass.sym;
663 throw handler.inaccessibleVarargs(location, t);
664 }
665 }
666 }
668 /**
669 * Check context to be used during method applicability checks. A method check
670 * context might contain inference variables.
671 */
672 abstract class MethodCheckContext implements CheckContext {
674 MethodCheckHandler handler;
675 boolean useVarargs;
676 Infer.InferenceContext inferenceContext;
677 Warner rsWarner;
679 public MethodCheckContext(MethodCheckHandler handler, boolean useVarargs, Infer.InferenceContext inferenceContext, Warner rsWarner) {
680 this.handler = handler;
681 this.useVarargs = useVarargs;
682 this.inferenceContext = inferenceContext;
683 this.rsWarner = rsWarner;
684 }
686 public void report(DiagnosticPosition pos, JCDiagnostic details) {
687 throw handler.argumentMismatch(useVarargs, details);
688 }
690 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
691 return rsWarner;
692 }
694 public InferenceContext inferenceContext() {
695 return inferenceContext;
696 }
697 }
699 /**
700 * Subclass of method check context class that implements strict method conversion.
701 * Strict method conversion checks compatibility between types using subtyping tests.
702 */
703 class StrictMethodContext extends MethodCheckContext {
705 public StrictMethodContext(MethodCheckHandler handler, boolean useVarargs, Infer.InferenceContext inferenceContext, Warner rsWarner) {
706 super(handler, useVarargs, inferenceContext, rsWarner);
707 }
709 public boolean compatible(Type found, Type req, Warner warn) {
710 return types.isSubtypeUnchecked(found, inferenceContext.asFree(req, types), warn);
711 }
712 }
714 /**
715 * Subclass of method check context class that implements loose method conversion.
716 * Loose method conversion checks compatibility between types using method conversion tests.
717 */
718 class LooseMethodContext extends MethodCheckContext {
720 public LooseMethodContext(MethodCheckHandler handler, boolean useVarargs, Infer.InferenceContext inferenceContext, Warner rsWarner) {
721 super(handler, useVarargs, inferenceContext, rsWarner);
722 }
724 public boolean compatible(Type found, Type req, Warner warn) {
725 return types.isConvertible(found, inferenceContext.asFree(req, types), warn);
726 }
727 }
729 /**
730 * Create a method check context to be used during method applicability check
731 */
732 ResultInfo methodCheckResult(Type to, boolean allowBoxing, boolean useVarargs,
733 Infer.InferenceContext inferenceContext, MethodCheckHandler methodHandler, Warner rsWarner) {
734 MethodCheckContext checkContext = allowBoxing ?
735 new LooseMethodContext(methodHandler, useVarargs, inferenceContext, rsWarner) :
736 new StrictMethodContext(methodHandler, useVarargs, inferenceContext, rsWarner);
737 return attr.new ResultInfo(VAL, to, checkContext) {
738 @Override
739 protected Type check(DiagnosticPosition pos, Type found) {
740 return super.check(pos, chk.checkNonVoid(pos, types.capture(types.upperBound(found))));
741 }
742 };
743 }
745 public static class InapplicableMethodException extends RuntimeException {
746 private static final long serialVersionUID = 0;
748 JCDiagnostic diagnostic;
749 JCDiagnostic.Factory diags;
751 InapplicableMethodException(JCDiagnostic.Factory diags) {
752 this.diagnostic = null;
753 this.diags = diags;
754 }
755 InapplicableMethodException setMessage() {
756 return setMessage((JCDiagnostic)null);
757 }
758 InapplicableMethodException setMessage(String key) {
759 return setMessage(key != null ? diags.fragment(key) : null);
760 }
761 InapplicableMethodException setMessage(String key, Object... args) {
762 return setMessage(key != null ? diags.fragment(key, args) : null);
763 }
764 InapplicableMethodException setMessage(JCDiagnostic diag) {
765 this.diagnostic = diag;
766 return this;
767 }
769 public JCDiagnostic getDiagnostic() {
770 return diagnostic;
771 }
772 }
773 private final InapplicableMethodException inapplicableMethodException;
775 /* ***************************************************************************
776 * Symbol lookup
777 * the following naming conventions for arguments are used
778 *
779 * env is the environment where the symbol was mentioned
780 * site is the type of which the symbol is a member
781 * name is the symbol's name
782 * if no arguments are given
783 * argtypes are the value arguments, if we search for a method
784 *
785 * If no symbol was found, a ResolveError detailing the problem is returned.
786 ****************************************************************************/
788 /** Find field. Synthetic fields are always skipped.
789 * @param env The current environment.
790 * @param site The original type from where the selection takes place.
791 * @param name The name of the field.
792 * @param c The class to search for the field. This is always
793 * a superclass or implemented interface of site's class.
794 */
795 Symbol findField(Env<AttrContext> env,
796 Type site,
797 Name name,
798 TypeSymbol c) {
799 while (c.type.tag == TYPEVAR)
800 c = c.type.getUpperBound().tsym;
801 Symbol bestSoFar = varNotFound;
802 Symbol sym;
803 Scope.Entry e = c.members().lookup(name);
804 while (e.scope != null) {
805 if (e.sym.kind == VAR && (e.sym.flags_field & SYNTHETIC) == 0) {
806 return isAccessible(env, site, e.sym)
807 ? e.sym : new AccessError(env, site, e.sym);
808 }
809 e = e.next();
810 }
811 Type st = types.supertype(c.type);
812 if (st != null && (st.tag == CLASS || st.tag == TYPEVAR)) {
813 sym = findField(env, site, name, st.tsym);
814 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
815 }
816 for (List<Type> l = types.interfaces(c.type);
817 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
818 l = l.tail) {
819 sym = findField(env, site, name, l.head.tsym);
820 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
821 sym.owner != bestSoFar.owner)
822 bestSoFar = new AmbiguityError(bestSoFar, sym);
823 else if (sym.kind < bestSoFar.kind)
824 bestSoFar = sym;
825 }
826 return bestSoFar;
827 }
829 /** Resolve a field identifier, throw a fatal error if not found.
830 * @param pos The position to use for error reporting.
831 * @param env The environment current at the method invocation.
832 * @param site The type of the qualifying expression, in which
833 * identifier is searched.
834 * @param name The identifier's name.
835 */
836 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
837 Type site, Name name) {
838 Symbol sym = findField(env, site, name, site.tsym);
839 if (sym.kind == VAR) return (VarSymbol)sym;
840 else throw new FatalError(
841 diags.fragment("fatal.err.cant.locate.field",
842 name));
843 }
845 /** Find unqualified variable or field with given name.
846 * Synthetic fields always skipped.
847 * @param env The current environment.
848 * @param name The name of the variable or field.
849 */
850 Symbol findVar(Env<AttrContext> env, Name name) {
851 Symbol bestSoFar = varNotFound;
852 Symbol sym;
853 Env<AttrContext> env1 = env;
854 boolean staticOnly = false;
855 while (env1.outer != null) {
856 if (isStatic(env1)) staticOnly = true;
857 Scope.Entry e = env1.info.scope.lookup(name);
858 while (e.scope != null &&
859 (e.sym.kind != VAR ||
860 (e.sym.flags_field & SYNTHETIC) != 0))
861 e = e.next();
862 sym = (e.scope != null)
863 ? e.sym
864 : findField(
865 env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
866 if (sym.exists()) {
867 if (staticOnly &&
868 sym.kind == VAR &&
869 sym.owner.kind == TYP &&
870 (sym.flags() & STATIC) == 0)
871 return new StaticError(sym);
872 else
873 return sym;
874 } else if (sym.kind < bestSoFar.kind) {
875 bestSoFar = sym;
876 }
878 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
879 env1 = env1.outer;
880 }
882 sym = findField(env, syms.predefClass.type, name, syms.predefClass);
883 if (sym.exists())
884 return sym;
885 if (bestSoFar.exists())
886 return bestSoFar;
888 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
889 for (; e.scope != null; e = e.next()) {
890 sym = e.sym;
891 Type origin = e.getOrigin().owner.type;
892 if (sym.kind == VAR) {
893 if (e.sym.owner.type != origin)
894 sym = sym.clone(e.getOrigin().owner);
895 return isAccessible(env, origin, sym)
896 ? sym : new AccessError(env, origin, sym);
897 }
898 }
900 Symbol origin = null;
901 e = env.toplevel.starImportScope.lookup(name);
902 for (; e.scope != null; e = e.next()) {
903 sym = e.sym;
904 if (sym.kind != VAR)
905 continue;
906 // invariant: sym.kind == VAR
907 if (bestSoFar.kind < AMBIGUOUS && sym.owner != bestSoFar.owner)
908 return new AmbiguityError(bestSoFar, sym);
909 else if (bestSoFar.kind >= VAR) {
910 origin = e.getOrigin().owner;
911 bestSoFar = isAccessible(env, origin.type, sym)
912 ? sym : new AccessError(env, origin.type, sym);
913 }
914 }
915 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
916 return bestSoFar.clone(origin);
917 else
918 return bestSoFar;
919 }
921 Warner noteWarner = new Warner();
923 /** Select the best method for a call site among two choices.
924 * @param env The current environment.
925 * @param site The original type from where the
926 * selection takes place.
927 * @param argtypes The invocation's value arguments,
928 * @param typeargtypes The invocation's type arguments,
929 * @param sym Proposed new best match.
930 * @param bestSoFar Previously found best match.
931 * @param allowBoxing Allow boxing conversions of arguments.
932 * @param useVarargs Box trailing arguments into an array for varargs.
933 */
934 @SuppressWarnings("fallthrough")
935 Symbol selectBest(Env<AttrContext> env,
936 Type site,
937 List<Type> argtypes,
938 List<Type> typeargtypes,
939 Symbol sym,
940 Symbol bestSoFar,
941 boolean allowBoxing,
942 boolean useVarargs,
943 boolean operator) {
944 if (sym.kind == ERR) return bestSoFar;
945 if (!sym.isInheritedIn(site.tsym, types)) return bestSoFar;
946 Assert.check(sym.kind < AMBIGUOUS);
947 try {
948 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes,
949 allowBoxing, useVarargs, Warner.noWarnings);
950 if (!operator)
951 currentResolutionContext.addApplicableCandidate(sym, mt);
952 } catch (InapplicableMethodException ex) {
953 if (!operator)
954 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic());
955 switch (bestSoFar.kind) {
956 case ABSENT_MTH:
957 return wrongMethod;
958 case WRONG_MTH:
959 if (operator) return bestSoFar;
960 case WRONG_MTHS:
961 return wrongMethods;
962 default:
963 return bestSoFar;
964 }
965 }
966 if (!isAccessible(env, site, sym)) {
967 return (bestSoFar.kind == ABSENT_MTH)
968 ? new AccessError(env, site, sym)
969 : bestSoFar;
970 }
971 return (bestSoFar.kind > AMBIGUOUS)
972 ? sym
973 : mostSpecific(sym, bestSoFar, env, site,
974 allowBoxing && operator, useVarargs);
975 }
977 /* Return the most specific of the two methods for a call,
978 * given that both are accessible and applicable.
979 * @param m1 A new candidate for most specific.
980 * @param m2 The previous most specific candidate.
981 * @param env The current environment.
982 * @param site The original type from where the selection
983 * takes place.
984 * @param allowBoxing Allow boxing conversions of arguments.
985 * @param useVarargs Box trailing arguments into an array for varargs.
986 */
987 Symbol mostSpecific(Symbol m1,
988 Symbol m2,
989 Env<AttrContext> env,
990 final Type site,
991 boolean allowBoxing,
992 boolean useVarargs) {
993 switch (m2.kind) {
994 case MTH:
995 if (m1 == m2) return m1;
996 boolean m1SignatureMoreSpecific = signatureMoreSpecific(env, site, m1, m2, allowBoxing, useVarargs);
997 boolean m2SignatureMoreSpecific = signatureMoreSpecific(env, site, m2, m1, allowBoxing, useVarargs);
998 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
999 Type mt1 = types.memberType(site, m1);
1000 Type mt2 = types.memberType(site, m2);
1001 if (!types.overrideEquivalent(mt1, mt2))
1002 return ambiguityError(m1, m2);
1004 // same signature; select (a) the non-bridge method, or
1005 // (b) the one that overrides the other, or (c) the concrete
1006 // one, or (d) merge both abstract signatures
1007 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
1008 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
1010 // if one overrides or hides the other, use it
1011 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
1012 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
1013 if (types.asSuper(m1Owner.type, m2Owner) != null &&
1014 ((m1.owner.flags_field & INTERFACE) == 0 ||
1015 (m2.owner.flags_field & INTERFACE) != 0) &&
1016 m1.overrides(m2, m1Owner, types, false))
1017 return m1;
1018 if (types.asSuper(m2Owner.type, m1Owner) != null &&
1019 ((m2.owner.flags_field & INTERFACE) == 0 ||
1020 (m1.owner.flags_field & INTERFACE) != 0) &&
1021 m2.overrides(m1, m2Owner, types, false))
1022 return m2;
1023 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
1024 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
1025 if (m1Abstract && !m2Abstract) return m2;
1026 if (m2Abstract && !m1Abstract) return m1;
1027 // both abstract or both concrete
1028 if (!m1Abstract && !m2Abstract)
1029 return ambiguityError(m1, m2);
1030 // check that both signatures have the same erasure
1031 if (!types.isSameTypes(m1.erasure(types).getParameterTypes(),
1032 m2.erasure(types).getParameterTypes()))
1033 return ambiguityError(m1, m2);
1034 // both abstract, neither overridden; merge throws clause and result type
1035 Type mst = mostSpecificReturnType(mt1, mt2);
1036 if (mst == null) {
1037 // Theoretically, this can't happen, but it is possible
1038 // due to error recovery or mixing incompatible class files
1039 return ambiguityError(m1, m2);
1040 }
1041 Symbol mostSpecific = mst == mt1 ? m1 : m2;
1042 List<Type> allThrown = chk.intersect(mt1.getThrownTypes(), mt2.getThrownTypes());
1043 Type newSig = types.createMethodTypeWithThrown(mostSpecific.type, allThrown);
1044 MethodSymbol result = new MethodSymbol(
1045 mostSpecific.flags(),
1046 mostSpecific.name,
1047 newSig,
1048 mostSpecific.owner) {
1049 @Override
1050 public MethodSymbol implementation(TypeSymbol origin, Types types, boolean checkResult) {
1051 if (origin == site.tsym)
1052 return this;
1053 else
1054 return super.implementation(origin, types, checkResult);
1055 }
1056 };
1057 return result;
1058 }
1059 if (m1SignatureMoreSpecific) return m1;
1060 if (m2SignatureMoreSpecific) return m2;
1061 return ambiguityError(m1, m2);
1062 case AMBIGUOUS:
1063 AmbiguityError e = (AmbiguityError)m2;
1064 Symbol err1 = mostSpecific(m1, e.sym, env, site, allowBoxing, useVarargs);
1065 Symbol err2 = mostSpecific(m1, e.sym2, env, site, allowBoxing, useVarargs);
1066 if (err1 == err2) return err1;
1067 if (err1 == e.sym && err2 == e.sym2) return m2;
1068 if (err1 instanceof AmbiguityError &&
1069 err2 instanceof AmbiguityError &&
1070 ((AmbiguityError)err1).sym == ((AmbiguityError)err2).sym)
1071 return ambiguityError(m1, m2);
1072 else
1073 return ambiguityError(err1, err2);
1074 default:
1075 throw new AssertionError();
1076 }
1077 }
1078 //where
1079 private boolean signatureMoreSpecific(Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean allowBoxing, boolean useVarargs) {
1080 noteWarner.clear();
1081 Type mtype1 = types.memberType(site, adjustVarargs(m1, m2, useVarargs));
1082 Type mtype2 = instantiate(env, site, adjustVarargs(m2, m1, useVarargs), null,
1083 types.lowerBoundArgtypes(mtype1), null,
1084 allowBoxing, false, noteWarner);
1085 return mtype2 != null &&
1086 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
1087 }
1088 //where
1089 private Symbol adjustVarargs(Symbol to, Symbol from, boolean useVarargs) {
1090 List<Type> fromArgs = from.type.getParameterTypes();
1091 List<Type> toArgs = to.type.getParameterTypes();
1092 if (useVarargs &&
1093 (from.flags() & VARARGS) != 0 &&
1094 (to.flags() & VARARGS) != 0) {
1095 Type varargsTypeFrom = fromArgs.last();
1096 Type varargsTypeTo = toArgs.last();
1097 ListBuffer<Type> args = ListBuffer.lb();
1098 if (toArgs.length() < fromArgs.length()) {
1099 //if we are checking a varargs method 'from' against another varargs
1100 //method 'to' (where arity of 'to' < arity of 'from') then expand signature
1101 //of 'to' to 'fit' arity of 'from' (this means adding fake formals to 'to'
1102 //until 'to' signature has the same arity as 'from')
1103 while (fromArgs.head != varargsTypeFrom) {
1104 args.append(toArgs.head == varargsTypeTo ? types.elemtype(varargsTypeTo) : toArgs.head);
1105 fromArgs = fromArgs.tail;
1106 toArgs = toArgs.head == varargsTypeTo ?
1107 toArgs :
1108 toArgs.tail;
1109 }
1110 } else {
1111 //formal argument list is same as original list where last
1112 //argument (array type) is removed
1113 args.appendList(toArgs.reverse().tail.reverse());
1114 }
1115 //append varargs element type as last synthetic formal
1116 args.append(types.elemtype(varargsTypeTo));
1117 Type mtype = types.createMethodTypeWithParameters(to.type, args.toList());
1118 return new MethodSymbol(to.flags_field & ~VARARGS, to.name, mtype, to.owner);
1119 } else {
1120 return to;
1121 }
1122 }
1123 //where
1124 Type mostSpecificReturnType(Type mt1, Type mt2) {
1125 Type rt1 = mt1.getReturnType();
1126 Type rt2 = mt2.getReturnType();
1128 if (mt1.tag == FORALL && mt2.tag == FORALL) {
1129 //if both are generic methods, adjust return type ahead of subtyping check
1130 rt1 = types.subst(rt1, mt1.getTypeArguments(), mt2.getTypeArguments());
1131 }
1132 //first use subtyping, then return type substitutability
1133 if (types.isSubtype(rt1, rt2)) {
1134 return mt1;
1135 } else if (types.isSubtype(rt2, rt1)) {
1136 return mt2;
1137 } else if (types.returnTypeSubstitutable(mt1, mt2)) {
1138 return mt1;
1139 } else if (types.returnTypeSubstitutable(mt2, mt1)) {
1140 return mt2;
1141 } else {
1142 return null;
1143 }
1144 }
1145 //where
1146 Symbol ambiguityError(Symbol m1, Symbol m2) {
1147 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
1148 return (m1.flags() & CLASH) == 0 ? m1 : m2;
1149 } else {
1150 return new AmbiguityError(m1, m2);
1151 }
1152 }
1154 /** Find best qualified method matching given name, type and value
1155 * arguments.
1156 * @param env The current environment.
1157 * @param site The original type from where the selection
1158 * takes place.
1159 * @param name The method's name.
1160 * @param argtypes The method's value arguments.
1161 * @param typeargtypes The method's type arguments
1162 * @param allowBoxing Allow boxing conversions of arguments.
1163 * @param useVarargs Box trailing arguments into an array for varargs.
1164 */
1165 Symbol findMethod(Env<AttrContext> env,
1166 Type site,
1167 Name name,
1168 List<Type> argtypes,
1169 List<Type> typeargtypes,
1170 boolean allowBoxing,
1171 boolean useVarargs,
1172 boolean operator) {
1173 Symbol bestSoFar = methodNotFound;
1174 bestSoFar = findMethod(env,
1175 site,
1176 name,
1177 argtypes,
1178 typeargtypes,
1179 site.tsym.type,
1180 bestSoFar,
1181 allowBoxing,
1182 useVarargs,
1183 operator);
1184 reportVerboseResolutionDiagnostic(env.tree.pos(), name, site, argtypes, typeargtypes, bestSoFar);
1185 return bestSoFar;
1186 }
1187 // where
1188 private Symbol findMethod(Env<AttrContext> env,
1189 Type site,
1190 Name name,
1191 List<Type> argtypes,
1192 List<Type> typeargtypes,
1193 Type intype,
1194 Symbol bestSoFar,
1195 boolean allowBoxing,
1196 boolean useVarargs,
1197 boolean operator) {
1198 boolean abstractOk = true;
1199 List<Type> itypes = List.nil();
1200 for (TypeSymbol s : superclasses(intype)) {
1201 bestSoFar = lookupMethod(env, site, name, argtypes, typeargtypes,
1202 s.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1203 abstractOk &= excludeAbstractsFilter.accepts(s);
1204 if (abstractOk) {
1205 for (Type itype : types.interfaces(s.type)) {
1206 itypes = types.union(types.closure(itype), itypes);
1207 }
1208 }
1209 if (name == names.init) break;
1210 }
1212 Symbol concrete = bestSoFar.kind < ERR &&
1213 (bestSoFar.flags() & ABSTRACT) == 0 ?
1214 bestSoFar : methodNotFound;
1216 if (name != names.init) {
1217 //keep searching for abstract methods
1218 for (Type itype : itypes) {
1219 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure())
1220 bestSoFar = lookupMethod(env, site, name, argtypes, typeargtypes,
1221 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1222 if (concrete != bestSoFar &&
1223 concrete.kind < ERR && bestSoFar.kind < ERR &&
1224 types.isSubSignature(concrete.type, bestSoFar.type)) {
1225 //this is an hack - as javac does not do full membership checks
1226 //most specific ends up comparing abstract methods that might have
1227 //been implemented by some concrete method in a subclass and,
1228 //because of raw override, it is possible for an abstract method
1229 //to be more specific than the concrete method - so we need
1230 //to explicitly call that out (see CR 6178365)
1231 bestSoFar = concrete;
1232 }
1233 }
1234 }
1235 return bestSoFar;
1236 }
1238 /**
1239 * Return an Iterable object to scan the superclasses of a given type.
1240 * It's crucial that the scan is done lazily, as we don't want to accidentally
1241 * access more supertypes than strictly needed (as this could trigger completion
1242 * errors if some of the not-needed supertypes are missing/ill-formed).
1243 */
1244 Iterable<TypeSymbol> superclasses(final Type intype) {
1245 return new Iterable<TypeSymbol>() {
1246 public Iterator<TypeSymbol> iterator() {
1247 return new Iterator<TypeSymbol>() {
1249 List<TypeSymbol> seen = List.nil();
1250 TypeSymbol currentSym = getSymbol(intype);
1252 public boolean hasNext() {
1253 return currentSym != null;
1254 }
1256 public TypeSymbol next() {
1257 TypeSymbol prevSym = currentSym;
1258 currentSym = getSymbol(types.supertype(currentSym.type));
1259 return prevSym;
1260 }
1262 public void remove() {
1263 throw new UnsupportedOperationException("Not supported yet.");
1264 }
1266 TypeSymbol getSymbol(Type intype) {
1267 if (intype.tag != CLASS &&
1268 intype.tag != TYPEVAR) {
1269 return null;
1270 }
1271 while (intype.tag == TYPEVAR)
1272 intype = intype.getUpperBound();
1273 if (seen.contains(intype.tsym)) {
1274 //degenerate case in which we have a circular
1275 //class hierarchy - because of ill-formed classfiles
1276 return null;
1277 }
1278 seen = seen.prepend(intype.tsym);
1279 return intype.tsym;
1280 }
1281 };
1282 }
1283 };
1284 }
1286 /**
1287 * We should not look for abstract methods if receiver is a concrete class
1288 * (as concrete classes are expected to implement all abstracts coming
1289 * from superinterfaces)
1290 */
1291 Filter<Symbol> excludeAbstractsFilter = new Filter<Symbol>() {
1292 public boolean accepts(Symbol s) {
1293 return (s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0;
1294 }
1295 };
1297 /**
1298 * Lookup a method with given name and argument types in a given scope
1299 */
1300 Symbol lookupMethod(Env<AttrContext> env,
1301 Type site,
1302 Name name,
1303 List<Type> argtypes,
1304 List<Type> typeargtypes,
1305 Scope sc,
1306 Symbol bestSoFar,
1307 boolean allowBoxing,
1308 boolean useVarargs,
1309 boolean operator,
1310 boolean abstractok) {
1311 for (Symbol s : sc.getElementsByName(name, lookupFilter)) {
1312 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s,
1313 bestSoFar, allowBoxing, useVarargs, operator);
1314 }
1315 return bestSoFar;
1316 }
1317 //where
1318 Filter<Symbol> lookupFilter = new Filter<Symbol>() {
1319 public boolean accepts(Symbol s) {
1320 return s.kind == MTH &&
1321 (s.flags() & SYNTHETIC) == 0;
1322 }
1323 };
1325 /** Find unqualified method matching given name, type and value arguments.
1326 * @param env The current environment.
1327 * @param name The method's name.
1328 * @param argtypes The method's value arguments.
1329 * @param typeargtypes The method's type arguments.
1330 * @param allowBoxing Allow boxing conversions of arguments.
1331 * @param useVarargs Box trailing arguments into an array for varargs.
1332 */
1333 Symbol findFun(Env<AttrContext> env, Name name,
1334 List<Type> argtypes, List<Type> typeargtypes,
1335 boolean allowBoxing, boolean useVarargs) {
1336 Symbol bestSoFar = methodNotFound;
1337 Symbol sym;
1338 Env<AttrContext> env1 = env;
1339 boolean staticOnly = false;
1340 while (env1.outer != null) {
1341 if (isStatic(env1)) staticOnly = true;
1342 sym = findMethod(
1343 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
1344 allowBoxing, useVarargs, false);
1345 if (sym.exists()) {
1346 if (staticOnly &&
1347 sym.kind == MTH &&
1348 sym.owner.kind == TYP &&
1349 (sym.flags() & STATIC) == 0) return new StaticError(sym);
1350 else return sym;
1351 } else if (sym.kind < bestSoFar.kind) {
1352 bestSoFar = sym;
1353 }
1354 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1355 env1 = env1.outer;
1356 }
1358 sym = findMethod(env, syms.predefClass.type, name, argtypes,
1359 typeargtypes, allowBoxing, useVarargs, false);
1360 if (sym.exists())
1361 return sym;
1363 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
1364 for (; e.scope != null; e = e.next()) {
1365 sym = e.sym;
1366 Type origin = e.getOrigin().owner.type;
1367 if (sym.kind == MTH) {
1368 if (e.sym.owner.type != origin)
1369 sym = sym.clone(e.getOrigin().owner);
1370 if (!isAccessible(env, origin, sym))
1371 sym = new AccessError(env, origin, sym);
1372 bestSoFar = selectBest(env, origin,
1373 argtypes, typeargtypes,
1374 sym, bestSoFar,
1375 allowBoxing, useVarargs, false);
1376 }
1377 }
1378 if (bestSoFar.exists())
1379 return bestSoFar;
1381 e = env.toplevel.starImportScope.lookup(name);
1382 for (; e.scope != null; e = e.next()) {
1383 sym = e.sym;
1384 Type origin = e.getOrigin().owner.type;
1385 if (sym.kind == MTH) {
1386 if (e.sym.owner.type != origin)
1387 sym = sym.clone(e.getOrigin().owner);
1388 if (!isAccessible(env, origin, sym))
1389 sym = new AccessError(env, origin, sym);
1390 bestSoFar = selectBest(env, origin,
1391 argtypes, typeargtypes,
1392 sym, bestSoFar,
1393 allowBoxing, useVarargs, false);
1394 }
1395 }
1396 return bestSoFar;
1397 }
1399 /** Load toplevel or member class with given fully qualified name and
1400 * verify that it is accessible.
1401 * @param env The current environment.
1402 * @param name The fully qualified name of the class to be loaded.
1403 */
1404 Symbol loadClass(Env<AttrContext> env, Name name) {
1405 try {
1406 ClassSymbol c = reader.loadClass(name);
1407 return isAccessible(env, c) ? c : new AccessError(c);
1408 } catch (ClassReader.BadClassFile err) {
1409 throw err;
1410 } catch (CompletionFailure ex) {
1411 return typeNotFound;
1412 }
1413 }
1415 /** Find qualified member type.
1416 * @param env The current environment.
1417 * @param site The original type from where the selection takes
1418 * place.
1419 * @param name The type's name.
1420 * @param c The class to search for the member type. This is
1421 * always a superclass or implemented interface of
1422 * site's class.
1423 */
1424 Symbol findMemberType(Env<AttrContext> env,
1425 Type site,
1426 Name name,
1427 TypeSymbol c) {
1428 Symbol bestSoFar = typeNotFound;
1429 Symbol sym;
1430 Scope.Entry e = c.members().lookup(name);
1431 while (e.scope != null) {
1432 if (e.sym.kind == TYP) {
1433 return isAccessible(env, site, e.sym)
1434 ? e.sym
1435 : new AccessError(env, site, e.sym);
1436 }
1437 e = e.next();
1438 }
1439 Type st = types.supertype(c.type);
1440 if (st != null && st.tag == CLASS) {
1441 sym = findMemberType(env, site, name, st.tsym);
1442 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1443 }
1444 for (List<Type> l = types.interfaces(c.type);
1445 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1446 l = l.tail) {
1447 sym = findMemberType(env, site, name, l.head.tsym);
1448 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1449 sym.owner != bestSoFar.owner)
1450 bestSoFar = new AmbiguityError(bestSoFar, sym);
1451 else if (sym.kind < bestSoFar.kind)
1452 bestSoFar = sym;
1453 }
1454 return bestSoFar;
1455 }
1457 /** Find a global type in given scope and load corresponding class.
1458 * @param env The current environment.
1459 * @param scope The scope in which to look for the type.
1460 * @param name The type's name.
1461 */
1462 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) {
1463 Symbol bestSoFar = typeNotFound;
1464 for (Scope.Entry e = scope.lookup(name); e.scope != null; e = e.next()) {
1465 Symbol sym = loadClass(env, e.sym.flatName());
1466 if (bestSoFar.kind == TYP && sym.kind == TYP &&
1467 bestSoFar != sym)
1468 return new AmbiguityError(bestSoFar, sym);
1469 else if (sym.kind < bestSoFar.kind)
1470 bestSoFar = sym;
1471 }
1472 return bestSoFar;
1473 }
1475 /** Find an unqualified type symbol.
1476 * @param env The current environment.
1477 * @param name The type's name.
1478 */
1479 Symbol findType(Env<AttrContext> env, Name name) {
1480 Symbol bestSoFar = typeNotFound;
1481 Symbol sym;
1482 boolean staticOnly = false;
1483 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
1484 if (isStatic(env1)) staticOnly = true;
1485 for (Scope.Entry e = env1.info.scope.lookup(name);
1486 e.scope != null;
1487 e = e.next()) {
1488 if (e.sym.kind == TYP) {
1489 if (staticOnly &&
1490 e.sym.type.tag == TYPEVAR &&
1491 e.sym.owner.kind == TYP) return new StaticError(e.sym);
1492 return e.sym;
1493 }
1494 }
1496 sym = findMemberType(env1, env1.enclClass.sym.type, name,
1497 env1.enclClass.sym);
1498 if (staticOnly && sym.kind == TYP &&
1499 sym.type.tag == CLASS &&
1500 sym.type.getEnclosingType().tag == CLASS &&
1501 env1.enclClass.sym.type.isParameterized() &&
1502 sym.type.getEnclosingType().isParameterized())
1503 return new StaticError(sym);
1504 else if (sym.exists()) return sym;
1505 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1507 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
1508 if ((encl.sym.flags() & STATIC) != 0)
1509 staticOnly = true;
1510 }
1512 if (!env.tree.hasTag(IMPORT)) {
1513 sym = findGlobalType(env, env.toplevel.namedImportScope, name);
1514 if (sym.exists()) return sym;
1515 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1517 sym = findGlobalType(env, env.toplevel.packge.members(), name);
1518 if (sym.exists()) return sym;
1519 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1521 sym = findGlobalType(env, env.toplevel.starImportScope, name);
1522 if (sym.exists()) return sym;
1523 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1524 }
1526 return bestSoFar;
1527 }
1529 /** Find an unqualified identifier which matches a specified kind set.
1530 * @param env The current environment.
1531 * @param name The indentifier's name.
1532 * @param kind Indicates the possible symbol kinds
1533 * (a subset of VAL, TYP, PCK).
1534 */
1535 Symbol findIdent(Env<AttrContext> env, Name name, int kind) {
1536 Symbol bestSoFar = typeNotFound;
1537 Symbol sym;
1539 if ((kind & VAR) != 0) {
1540 sym = findVar(env, name);
1541 if (sym.exists()) return sym;
1542 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1543 }
1545 if ((kind & TYP) != 0) {
1546 sym = findType(env, name);
1547 if (sym.exists()) return sym;
1548 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1549 }
1551 if ((kind & PCK) != 0) return reader.enterPackage(name);
1552 else return bestSoFar;
1553 }
1555 /** Find an identifier in a package which matches a specified kind set.
1556 * @param env The current environment.
1557 * @param name The identifier's name.
1558 * @param kind Indicates the possible symbol kinds
1559 * (a nonempty subset of TYP, PCK).
1560 */
1561 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
1562 Name name, int kind) {
1563 Name fullname = TypeSymbol.formFullName(name, pck);
1564 Symbol bestSoFar = typeNotFound;
1565 PackageSymbol pack = null;
1566 if ((kind & PCK) != 0) {
1567 pack = reader.enterPackage(fullname);
1568 if (pack.exists()) return pack;
1569 }
1570 if ((kind & TYP) != 0) {
1571 Symbol sym = loadClass(env, fullname);
1572 if (sym.exists()) {
1573 // don't allow programs to use flatnames
1574 if (name == sym.name) return sym;
1575 }
1576 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1577 }
1578 return (pack != null) ? pack : bestSoFar;
1579 }
1581 /** Find an identifier among the members of a given type `site'.
1582 * @param env The current environment.
1583 * @param site The type containing the symbol to be found.
1584 * @param name The identifier's name.
1585 * @param kind Indicates the possible symbol kinds
1586 * (a subset of VAL, TYP).
1587 */
1588 Symbol findIdentInType(Env<AttrContext> env, Type site,
1589 Name name, int kind) {
1590 Symbol bestSoFar = typeNotFound;
1591 Symbol sym;
1592 if ((kind & VAR) != 0) {
1593 sym = findField(env, site, name, site.tsym);
1594 if (sym.exists()) return sym;
1595 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1596 }
1598 if ((kind & TYP) != 0) {
1599 sym = findMemberType(env, site, name, site.tsym);
1600 if (sym.exists()) return sym;
1601 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1602 }
1603 return bestSoFar;
1604 }
1606 /* ***************************************************************************
1607 * Access checking
1608 * The following methods convert ResolveErrors to ErrorSymbols, issuing
1609 * an error message in the process
1610 ****************************************************************************/
1612 /** If `sym' is a bad symbol: report error and return errSymbol
1613 * else pass through unchanged,
1614 * additional arguments duplicate what has been used in trying to find the
1615 * symbol {@literal (--> flyweight pattern)}. This improves performance since we
1616 * expect misses to happen frequently.
1617 *
1618 * @param sym The symbol that was found, or a ResolveError.
1619 * @param pos The position to use for error reporting.
1620 * @param site The original type from where the selection took place.
1621 * @param name The symbol's name.
1622 * @param argtypes The invocation's value arguments,
1623 * if we looked for a method.
1624 * @param typeargtypes The invocation's type arguments,
1625 * if we looked for a method.
1626 */
1627 Symbol access(Symbol sym,
1628 DiagnosticPosition pos,
1629 Symbol location,
1630 Type site,
1631 Name name,
1632 boolean qualified,
1633 List<Type> argtypes,
1634 List<Type> typeargtypes) {
1635 if (sym.kind >= AMBIGUOUS) {
1636 ResolveError errSym = (ResolveError)sym;
1637 if (!site.isErroneous() &&
1638 !Type.isErroneous(argtypes) &&
1639 (typeargtypes==null || !Type.isErroneous(typeargtypes)))
1640 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
1641 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
1642 }
1643 return sym;
1644 }
1646 /** Same as original access(), but without location.
1647 */
1648 Symbol access(Symbol sym,
1649 DiagnosticPosition pos,
1650 Type site,
1651 Name name,
1652 boolean qualified,
1653 List<Type> argtypes,
1654 List<Type> typeargtypes) {
1655 return access(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
1656 }
1658 /** Same as original access(), but without type arguments and arguments.
1659 */
1660 Symbol access(Symbol sym,
1661 DiagnosticPosition pos,
1662 Symbol location,
1663 Type site,
1664 Name name,
1665 boolean qualified) {
1666 if (sym.kind >= AMBIGUOUS)
1667 return access(sym, pos, location, site, name, qualified, List.<Type>nil(), null);
1668 else
1669 return sym;
1670 }
1672 /** Same as original access(), but without location, type arguments and arguments.
1673 */
1674 Symbol access(Symbol sym,
1675 DiagnosticPosition pos,
1676 Type site,
1677 Name name,
1678 boolean qualified) {
1679 return access(sym, pos, site.tsym, site, name, qualified);
1680 }
1682 /** Check that sym is not an abstract method.
1683 */
1684 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
1685 if ((sym.flags() & ABSTRACT) != 0)
1686 log.error(pos, "abstract.cant.be.accessed.directly",
1687 kindName(sym), sym, sym.location());
1688 }
1690 /* ***************************************************************************
1691 * Debugging
1692 ****************************************************************************/
1694 /** print all scopes starting with scope s and proceeding outwards.
1695 * used for debugging.
1696 */
1697 public void printscopes(Scope s) {
1698 while (s != null) {
1699 if (s.owner != null)
1700 System.err.print(s.owner + ": ");
1701 for (Scope.Entry e = s.elems; e != null; e = e.sibling) {
1702 if ((e.sym.flags() & ABSTRACT) != 0)
1703 System.err.print("abstract ");
1704 System.err.print(e.sym + " ");
1705 }
1706 System.err.println();
1707 s = s.next;
1708 }
1709 }
1711 void printscopes(Env<AttrContext> env) {
1712 while (env.outer != null) {
1713 System.err.println("------------------------------");
1714 printscopes(env.info.scope);
1715 env = env.outer;
1716 }
1717 }
1719 public void printscopes(Type t) {
1720 while (t.tag == CLASS) {
1721 printscopes(t.tsym.members());
1722 t = types.supertype(t);
1723 }
1724 }
1726 /* ***************************************************************************
1727 * Name resolution
1728 * Naming conventions are as for symbol lookup
1729 * Unlike the find... methods these methods will report access errors
1730 ****************************************************************************/
1732 /** Resolve an unqualified (non-method) identifier.
1733 * @param pos The position to use for error reporting.
1734 * @param env The environment current at the identifier use.
1735 * @param name The identifier's name.
1736 * @param kind The set of admissible symbol kinds for the identifier.
1737 */
1738 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
1739 Name name, int kind) {
1740 return access(
1741 findIdent(env, name, kind),
1742 pos, env.enclClass.sym.type, name, false);
1743 }
1745 /** Resolve an unqualified method identifier.
1746 * @param pos The position to use for error reporting.
1747 * @param env The environment current at the method invocation.
1748 * @param name The identifier's name.
1749 * @param argtypes The types of the invocation's value arguments.
1750 * @param typeargtypes The types of the invocation's type arguments.
1751 */
1752 Symbol resolveMethod(DiagnosticPosition pos,
1753 Env<AttrContext> env,
1754 Name name,
1755 List<Type> argtypes,
1756 List<Type> typeargtypes) {
1757 MethodResolutionContext prevResolutionContext = currentResolutionContext;
1758 try {
1759 currentResolutionContext = new MethodResolutionContext();
1760 Symbol sym = methodNotFound;
1761 List<MethodResolutionPhase> steps = methodResolutionSteps;
1762 while (steps.nonEmpty() &&
1763 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1764 sym.kind >= ERRONEOUS) {
1765 currentResolutionContext.step = steps.head;
1766 sym = findFun(env, name, argtypes, typeargtypes,
1767 steps.head.isBoxingRequired,
1768 env.info.varArgs = steps.head.isVarargsRequired);
1769 currentResolutionContext.resolutionCache.put(steps.head, sym);
1770 steps = steps.tail;
1771 }
1772 if (sym.kind >= AMBIGUOUS) {//if nothing is found return the 'first' error
1773 MethodResolutionPhase errPhase =
1774 currentResolutionContext.firstErroneousResolutionPhase();
1775 sym = access(currentResolutionContext.resolutionCache.get(errPhase),
1776 pos, env.enclClass.sym.type, name, false, argtypes, typeargtypes);
1777 env.info.varArgs = errPhase.isVarargsRequired;
1778 }
1779 return sym;
1780 }
1781 finally {
1782 currentResolutionContext = prevResolutionContext;
1783 }
1784 }
1786 /** Resolve a qualified method identifier
1787 * @param pos The position to use for error reporting.
1788 * @param env The environment current at the method invocation.
1789 * @param site The type of the qualifying expression, in which
1790 * identifier is searched.
1791 * @param name The identifier's name.
1792 * @param argtypes The types of the invocation's value arguments.
1793 * @param typeargtypes The types of the invocation's type arguments.
1794 */
1795 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
1796 Type site, Name name, List<Type> argtypes,
1797 List<Type> typeargtypes) {
1798 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
1799 }
1800 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
1801 Symbol location, Type site, Name name, List<Type> argtypes,
1802 List<Type> typeargtypes) {
1803 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
1804 }
1805 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
1806 DiagnosticPosition pos, Env<AttrContext> env,
1807 Symbol location, Type site, Name name, List<Type> argtypes,
1808 List<Type> typeargtypes) {
1809 MethodResolutionContext prevResolutionContext = currentResolutionContext;
1810 try {
1811 currentResolutionContext = resolveContext;
1812 Symbol sym = methodNotFound;
1813 List<MethodResolutionPhase> steps = methodResolutionSteps;
1814 while (steps.nonEmpty() &&
1815 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1816 sym.kind >= ERRONEOUS) {
1817 currentResolutionContext.step = steps.head;
1818 sym = findMethod(env, site, name, argtypes, typeargtypes,
1819 steps.head.isBoxingRequired(),
1820 env.info.varArgs = steps.head.isVarargsRequired(), false);
1821 currentResolutionContext.resolutionCache.put(steps.head, sym);
1822 steps = steps.tail;
1823 }
1824 if (sym.kind >= AMBIGUOUS) {
1825 //if nothing is found return the 'first' error
1826 MethodResolutionPhase errPhase =
1827 currentResolutionContext.firstErroneousResolutionPhase();
1828 sym = access(currentResolutionContext.resolutionCache.get(errPhase),
1829 pos, location, site, name, true, argtypes, typeargtypes);
1830 env.info.varArgs = errPhase.isVarargsRequired;
1831 } else if (allowMethodHandles) {
1832 MethodSymbol msym = (MethodSymbol)sym;
1833 if (msym.isSignaturePolymorphic(types)) {
1834 env.info.varArgs = false;
1835 return findPolymorphicSignatureInstance(env, sym, argtypes);
1836 }
1837 }
1838 return sym;
1839 }
1840 finally {
1841 currentResolutionContext = prevResolutionContext;
1842 }
1843 }
1845 /** Find or create an implicit method of exactly the given type (after erasure).
1846 * Searches in a side table, not the main scope of the site.
1847 * This emulates the lookup process required by JSR 292 in JVM.
1848 * @param env Attribution environment
1849 * @param spMethod signature polymorphic method - i.e. MH.invokeExact
1850 * @param argtypes The required argument types
1851 */
1852 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env,
1853 Symbol spMethod,
1854 List<Type> argtypes) {
1855 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
1856 (MethodSymbol)spMethod, argtypes);
1857 for (Symbol sym : polymorphicSignatureScope.getElementsByName(spMethod.name)) {
1858 if (types.isSameType(mtype, sym.type)) {
1859 return sym;
1860 }
1861 }
1863 // create the desired method
1864 long flags = ABSTRACT | HYPOTHETICAL | spMethod.flags() & Flags.AccessFlags;
1865 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner);
1866 polymorphicSignatureScope.enter(msym);
1867 return msym;
1868 }
1870 /** Resolve a qualified method identifier, throw a fatal error if not
1871 * found.
1872 * @param pos The position to use for error reporting.
1873 * @param env The environment current at the method invocation.
1874 * @param site The type of the qualifying expression, in which
1875 * identifier is searched.
1876 * @param name The identifier's name.
1877 * @param argtypes The types of the invocation's value arguments.
1878 * @param typeargtypes The types of the invocation's type arguments.
1879 */
1880 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
1881 Type site, Name name,
1882 List<Type> argtypes,
1883 List<Type> typeargtypes) {
1884 MethodResolutionContext resolveContext = new MethodResolutionContext();
1885 resolveContext.internalResolution = true;
1886 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
1887 site, name, argtypes, typeargtypes);
1888 if (sym.kind == MTH) return (MethodSymbol)sym;
1889 else throw new FatalError(
1890 diags.fragment("fatal.err.cant.locate.meth",
1891 name));
1892 }
1894 /** Resolve constructor.
1895 * @param pos The position to use for error reporting.
1896 * @param env The environment current at the constructor invocation.
1897 * @param site The type of class for which a constructor is searched.
1898 * @param argtypes The types of the constructor invocation's value
1899 * arguments.
1900 * @param typeargtypes The types of the constructor invocation's type
1901 * arguments.
1902 */
1903 Symbol resolveConstructor(DiagnosticPosition pos,
1904 Env<AttrContext> env,
1905 Type site,
1906 List<Type> argtypes,
1907 List<Type> typeargtypes) {
1908 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
1909 }
1910 private Symbol resolveConstructor(MethodResolutionContext resolveContext,
1911 DiagnosticPosition pos,
1912 Env<AttrContext> env,
1913 Type site,
1914 List<Type> argtypes,
1915 List<Type> typeargtypes) {
1916 MethodResolutionContext prevResolutionContext = currentResolutionContext;
1917 try {
1918 currentResolutionContext = resolveContext;
1919 Symbol sym = methodNotFound;
1920 List<MethodResolutionPhase> steps = methodResolutionSteps;
1921 while (steps.nonEmpty() &&
1922 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1923 sym.kind >= ERRONEOUS) {
1924 currentResolutionContext.step = steps.head;
1925 sym = findConstructor(pos, env, site, argtypes, typeargtypes,
1926 steps.head.isBoxingRequired(),
1927 env.info.varArgs = steps.head.isVarargsRequired());
1928 currentResolutionContext.resolutionCache.put(steps.head, sym);
1929 steps = steps.tail;
1930 }
1931 if (sym.kind >= AMBIGUOUS) {//if nothing is found return the 'first' error
1932 MethodResolutionPhase errPhase = currentResolutionContext.firstErroneousResolutionPhase();
1933 sym = access(currentResolutionContext.resolutionCache.get(errPhase),
1934 pos, site, names.init, true, argtypes, typeargtypes);
1935 env.info.varArgs = errPhase.isVarargsRequired();
1936 }
1937 return sym;
1938 }
1939 finally {
1940 currentResolutionContext = prevResolutionContext;
1941 }
1942 }
1944 /** Resolve constructor using diamond inference.
1945 * @param pos The position to use for error reporting.
1946 * @param env The environment current at the constructor invocation.
1947 * @param site The type of class for which a constructor is searched.
1948 * The scope of this class has been touched in attribution.
1949 * @param argtypes The types of the constructor invocation's value
1950 * arguments.
1951 * @param typeargtypes The types of the constructor invocation's type
1952 * arguments.
1953 */
1954 Symbol resolveDiamond(DiagnosticPosition pos,
1955 Env<AttrContext> env,
1956 Type site,
1957 List<Type> argtypes,
1958 List<Type> typeargtypes) {
1959 MethodResolutionContext prevResolutionContext = currentResolutionContext;
1960 try {
1961 currentResolutionContext = new MethodResolutionContext();
1962 Symbol sym = methodNotFound;
1963 List<MethodResolutionPhase> steps = methodResolutionSteps;
1964 while (steps.nonEmpty() &&
1965 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1966 sym.kind >= ERRONEOUS) {
1967 currentResolutionContext.step = steps.head;
1968 sym = findDiamond(env, site, argtypes, typeargtypes,
1969 steps.head.isBoxingRequired(),
1970 env.info.varArgs = steps.head.isVarargsRequired());
1971 currentResolutionContext.resolutionCache.put(steps.head, sym);
1972 steps = steps.tail;
1973 }
1974 if (sym.kind >= AMBIGUOUS) {
1975 final JCDiagnostic details = sym.kind == WRONG_MTH ?
1976 currentResolutionContext.candidates.head.details :
1977 null;
1978 Symbol errSym = new ResolveError(WRONG_MTH, "diamond error") {
1979 @Override
1980 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
1981 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
1982 String key = details == null ?
1983 "cant.apply.diamond" :
1984 "cant.apply.diamond.1";
1985 return diags.create(dkind, log.currentSource(), pos, key,
1986 diags.fragment("diamond", site.tsym), details);
1987 }
1988 };
1989 MethodResolutionPhase errPhase = currentResolutionContext.firstErroneousResolutionPhase();
1990 sym = access(errSym, pos, site, names.init, true, argtypes, typeargtypes);
1991 env.info.varArgs = errPhase.isVarargsRequired();
1992 }
1993 return sym;
1994 }
1995 finally {
1996 currentResolutionContext = prevResolutionContext;
1997 }
1998 }
2000 /** This method scans all the constructor symbol in a given class scope -
2001 * assuming that the original scope contains a constructor of the kind:
2002 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
2003 * a method check is executed against the modified constructor type:
2004 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond
2005 * inference. The inferred return type of the synthetic constructor IS
2006 * the inferred type for the diamond operator.
2007 */
2008 private Symbol findDiamond(Env<AttrContext> env,
2009 Type site,
2010 List<Type> argtypes,
2011 List<Type> typeargtypes,
2012 boolean allowBoxing,
2013 boolean useVarargs) {
2014 Symbol bestSoFar = methodNotFound;
2015 for (Scope.Entry e = site.tsym.members().lookup(names.init);
2016 e.scope != null;
2017 e = e.next()) {
2018 //- System.out.println(" e " + e.sym);
2019 if (e.sym.kind == MTH &&
2020 (e.sym.flags_field & SYNTHETIC) == 0) {
2021 List<Type> oldParams = e.sym.type.tag == FORALL ?
2022 ((ForAll)e.sym.type).tvars :
2023 List.<Type>nil();
2024 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
2025 types.createMethodTypeWithReturn(e.sym.type.asMethodType(), site));
2026 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
2027 new MethodSymbol(e.sym.flags(), names.init, constrType, site.tsym),
2028 bestSoFar,
2029 allowBoxing,
2030 useVarargs,
2031 false);
2032 }
2033 }
2034 return bestSoFar;
2035 }
2037 /** Resolve constructor.
2038 * @param pos The position to use for error reporting.
2039 * @param env The environment current at the constructor invocation.
2040 * @param site The type of class for which a constructor is searched.
2041 * @param argtypes The types of the constructor invocation's value
2042 * arguments.
2043 * @param typeargtypes The types of the constructor invocation's type
2044 * arguments.
2045 * @param allowBoxing Allow boxing and varargs conversions.
2046 * @param useVarargs Box trailing arguments into an array for varargs.
2047 */
2048 Symbol resolveConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2049 Type site, List<Type> argtypes,
2050 List<Type> typeargtypes,
2051 boolean allowBoxing,
2052 boolean useVarargs) {
2053 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2054 try {
2055 currentResolutionContext = new MethodResolutionContext();
2056 return findConstructor(pos, env, site, argtypes, typeargtypes, allowBoxing, useVarargs);
2057 }
2058 finally {
2059 currentResolutionContext = prevResolutionContext;
2060 }
2061 }
2063 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2064 Type site, List<Type> argtypes,
2065 List<Type> typeargtypes,
2066 boolean allowBoxing,
2067 boolean useVarargs) {
2068 Symbol sym = findMethod(env, site,
2069 names.init, argtypes,
2070 typeargtypes, allowBoxing,
2071 useVarargs, false);
2072 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2073 return sym;
2074 }
2076 /** Resolve a constructor, throw a fatal error if not found.
2077 * @param pos The position to use for error reporting.
2078 * @param env The environment current at the method invocation.
2079 * @param site The type to be constructed.
2080 * @param argtypes The types of the invocation's value arguments.
2081 * @param typeargtypes The types of the invocation's type arguments.
2082 */
2083 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2084 Type site,
2085 List<Type> argtypes,
2086 List<Type> typeargtypes) {
2087 MethodResolutionContext resolveContext = new MethodResolutionContext();
2088 resolveContext.internalResolution = true;
2089 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
2090 if (sym.kind == MTH) return (MethodSymbol)sym;
2091 else throw new FatalError(
2092 diags.fragment("fatal.err.cant.locate.ctor", site));
2093 }
2095 /** Resolve operator.
2096 * @param pos The position to use for error reporting.
2097 * @param optag The tag of the operation tree.
2098 * @param env The environment current at the operation.
2099 * @param argtypes The types of the operands.
2100 */
2101 Symbol resolveOperator(DiagnosticPosition pos, JCTree.Tag optag,
2102 Env<AttrContext> env, List<Type> argtypes) {
2103 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2104 try {
2105 currentResolutionContext = new MethodResolutionContext();
2106 Name name = treeinfo.operatorName(optag);
2107 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
2108 null, false, false, true);
2109 if (boxingEnabled && sym.kind >= WRONG_MTHS)
2110 sym = findMethod(env, syms.predefClass.type, name, argtypes,
2111 null, true, false, true);
2112 return access(sym, pos, env.enclClass.sym.type, name,
2113 false, argtypes, null);
2114 }
2115 finally {
2116 currentResolutionContext = prevResolutionContext;
2117 }
2118 }
2120 /** Resolve operator.
2121 * @param pos The position to use for error reporting.
2122 * @param optag The tag of the operation tree.
2123 * @param env The environment current at the operation.
2124 * @param arg The type of the operand.
2125 */
2126 Symbol resolveUnaryOperator(DiagnosticPosition pos, JCTree.Tag optag, Env<AttrContext> env, Type arg) {
2127 return resolveOperator(pos, optag, env, List.of(arg));
2128 }
2130 /** Resolve binary operator.
2131 * @param pos The position to use for error reporting.
2132 * @param optag The tag of the operation tree.
2133 * @param env The environment current at the operation.
2134 * @param left The types of the left operand.
2135 * @param right The types of the right operand.
2136 */
2137 Symbol resolveBinaryOperator(DiagnosticPosition pos,
2138 JCTree.Tag optag,
2139 Env<AttrContext> env,
2140 Type left,
2141 Type right) {
2142 return resolveOperator(pos, optag, env, List.of(left, right));
2143 }
2145 /**
2146 * Resolve `c.name' where name == this or name == super.
2147 * @param pos The position to use for error reporting.
2148 * @param env The environment current at the expression.
2149 * @param c The qualifier.
2150 * @param name The identifier's name.
2151 */
2152 Symbol resolveSelf(DiagnosticPosition pos,
2153 Env<AttrContext> env,
2154 TypeSymbol c,
2155 Name name) {
2156 Env<AttrContext> env1 = env;
2157 boolean staticOnly = false;
2158 while (env1.outer != null) {
2159 if (isStatic(env1)) staticOnly = true;
2160 if (env1.enclClass.sym == c) {
2161 Symbol sym = env1.info.scope.lookup(name).sym;
2162 if (sym != null) {
2163 if (staticOnly) sym = new StaticError(sym);
2164 return access(sym, pos, env.enclClass.sym.type,
2165 name, true);
2166 }
2167 }
2168 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
2169 env1 = env1.outer;
2170 }
2171 log.error(pos, "not.encl.class", c);
2172 return syms.errSymbol;
2173 }
2175 /**
2176 * Resolve `c.this' for an enclosing class c that contains the
2177 * named member.
2178 * @param pos The position to use for error reporting.
2179 * @param env The environment current at the expression.
2180 * @param member The member that must be contained in the result.
2181 */
2182 Symbol resolveSelfContaining(DiagnosticPosition pos,
2183 Env<AttrContext> env,
2184 Symbol member,
2185 boolean isSuperCall) {
2186 Name name = names._this;
2187 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
2188 boolean staticOnly = false;
2189 if (env1 != null) {
2190 while (env1 != null && env1.outer != null) {
2191 if (isStatic(env1)) staticOnly = true;
2192 if (env1.enclClass.sym.isSubClass(member.owner, types)) {
2193 Symbol sym = env1.info.scope.lookup(name).sym;
2194 if (sym != null) {
2195 if (staticOnly) sym = new StaticError(sym);
2196 return access(sym, pos, env.enclClass.sym.type,
2197 name, true);
2198 }
2199 }
2200 if ((env1.enclClass.sym.flags() & STATIC) != 0)
2201 staticOnly = true;
2202 env1 = env1.outer;
2203 }
2204 }
2205 log.error(pos, "encl.class.required", member);
2206 return syms.errSymbol;
2207 }
2209 /**
2210 * Resolve an appropriate implicit this instance for t's container.
2211 * JLS 8.8.5.1 and 15.9.2
2212 */
2213 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
2214 return resolveImplicitThis(pos, env, t, false);
2215 }
2217 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
2218 Type thisType = (((t.tsym.owner.kind & (MTH|VAR)) != 0)
2219 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
2220 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
2221 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym)
2222 log.error(pos, "cant.ref.before.ctor.called", "this");
2223 return thisType;
2224 }
2226 /* ***************************************************************************
2227 * ResolveError classes, indicating error situations when accessing symbols
2228 ****************************************************************************/
2230 //used by TransTypes when checking target type of synthetic cast
2231 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) {
2232 AccessError error = new AccessError(env, env.enclClass.type, type.tsym);
2233 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null);
2234 }
2235 //where
2236 private void logResolveError(ResolveError error,
2237 DiagnosticPosition pos,
2238 Symbol location,
2239 Type site,
2240 Name name,
2241 List<Type> argtypes,
2242 List<Type> typeargtypes) {
2243 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
2244 pos, location, site, name, argtypes, typeargtypes);
2245 if (d != null) {
2246 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
2247 log.report(d);
2248 }
2249 }
2251 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
2253 public Object methodArguments(List<Type> argtypes) {
2254 return argtypes == null || argtypes.isEmpty() ? noArgs : argtypes;
2255 }
2257 /**
2258 * Root class for resolution errors. Subclass of ResolveError
2259 * represent a different kinds of resolution error - as such they must
2260 * specify how they map into concrete compiler diagnostics.
2261 */
2262 private abstract class ResolveError extends Symbol {
2264 /** The name of the kind of error, for debugging only. */
2265 final String debugName;
2267 ResolveError(int kind, String debugName) {
2268 super(kind, 0, null, null, null);
2269 this.debugName = debugName;
2270 }
2272 @Override
2273 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
2274 throw new AssertionError();
2275 }
2277 @Override
2278 public String toString() {
2279 return debugName;
2280 }
2282 @Override
2283 public boolean exists() {
2284 return false;
2285 }
2287 /**
2288 * Create an external representation for this erroneous symbol to be
2289 * used during attribution - by default this returns the symbol of a
2290 * brand new error type which stores the original type found
2291 * during resolution.
2292 *
2293 * @param name the name used during resolution
2294 * @param location the location from which the symbol is accessed
2295 */
2296 protected Symbol access(Name name, TypeSymbol location) {
2297 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
2298 }
2300 /**
2301 * Create a diagnostic representing this resolution error.
2302 *
2303 * @param dkind The kind of the diagnostic to be created (e.g error).
2304 * @param pos The position to be used for error reporting.
2305 * @param site The original type from where the selection took place.
2306 * @param name The name of the symbol to be resolved.
2307 * @param argtypes The invocation's value arguments,
2308 * if we looked for a method.
2309 * @param typeargtypes The invocation's type arguments,
2310 * if we looked for a method.
2311 */
2312 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2313 DiagnosticPosition pos,
2314 Symbol location,
2315 Type site,
2316 Name name,
2317 List<Type> argtypes,
2318 List<Type> typeargtypes);
2320 /**
2321 * A name designates an operator if it consists
2322 * of a non-empty sequence of operator symbols {@literal +-~!/*%&|^<>= }
2323 */
2324 boolean isOperator(Name name) {
2325 int i = 0;
2326 while (i < name.getByteLength() &&
2327 "+-~!*/%&|^<>=".indexOf(name.getByteAt(i)) >= 0) i++;
2328 return i > 0 && i == name.getByteLength();
2329 }
2330 }
2332 /**
2333 * This class is the root class of all resolution errors caused by
2334 * an invalid symbol being found during resolution.
2335 */
2336 abstract class InvalidSymbolError extends ResolveError {
2338 /** The invalid symbol found during resolution */
2339 Symbol sym;
2341 InvalidSymbolError(int kind, Symbol sym, String debugName) {
2342 super(kind, debugName);
2343 this.sym = sym;
2344 }
2346 @Override
2347 public boolean exists() {
2348 return true;
2349 }
2351 @Override
2352 public String toString() {
2353 return super.toString() + " wrongSym=" + sym;
2354 }
2356 @Override
2357 public Symbol access(Name name, TypeSymbol location) {
2358 if (sym.kind >= AMBIGUOUS)
2359 return ((ResolveError)sym).access(name, location);
2360 else if ((sym.kind & ERRONEOUS) == 0 && (sym.kind & TYP) != 0)
2361 return types.createErrorType(name, location, sym.type).tsym;
2362 else
2363 return sym;
2364 }
2365 }
2367 /**
2368 * InvalidSymbolError error class indicating that a symbol matching a
2369 * given name does not exists in a given site.
2370 */
2371 class SymbolNotFoundError extends ResolveError {
2373 SymbolNotFoundError(int kind) {
2374 super(kind, "symbol not found error");
2375 }
2377 @Override
2378 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2379 DiagnosticPosition pos,
2380 Symbol location,
2381 Type site,
2382 Name name,
2383 List<Type> argtypes,
2384 List<Type> typeargtypes) {
2385 argtypes = argtypes == null ? List.<Type>nil() : argtypes;
2386 typeargtypes = typeargtypes == null ? List.<Type>nil() : typeargtypes;
2387 if (name == names.error)
2388 return null;
2390 if (isOperator(name)) {
2391 boolean isUnaryOp = argtypes.size() == 1;
2392 String key = argtypes.size() == 1 ?
2393 "operator.cant.be.applied" :
2394 "operator.cant.be.applied.1";
2395 Type first = argtypes.head;
2396 Type second = !isUnaryOp ? argtypes.tail.head : null;
2397 return diags.create(dkind, log.currentSource(), pos,
2398 key, name, first, second);
2399 }
2400 boolean hasLocation = false;
2401 if (location == null) {
2402 location = site.tsym;
2403 }
2404 if (!location.name.isEmpty()) {
2405 if (location.kind == PCK && !site.tsym.exists()) {
2406 return diags.create(dkind, log.currentSource(), pos,
2407 "doesnt.exist", location);
2408 }
2409 hasLocation = !location.name.equals(names._this) &&
2410 !location.name.equals(names._super);
2411 }
2412 boolean isConstructor = kind == ABSENT_MTH &&
2413 name == names.table.names.init;
2414 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : absentKind(kind);
2415 Name idname = isConstructor ? site.tsym.name : name;
2416 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
2417 if (hasLocation) {
2418 return diags.create(dkind, log.currentSource(), pos,
2419 errKey, kindname, idname, //symbol kindname, name
2420 typeargtypes, argtypes, //type parameters and arguments (if any)
2421 getLocationDiag(location, site)); //location kindname, type
2422 }
2423 else {
2424 return diags.create(dkind, log.currentSource(), pos,
2425 errKey, kindname, idname, //symbol kindname, name
2426 typeargtypes, argtypes); //type parameters and arguments (if any)
2427 }
2428 }
2429 //where
2430 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
2431 String key = "cant.resolve";
2432 String suffix = hasLocation ? ".location" : "";
2433 switch (kindname) {
2434 case METHOD:
2435 case CONSTRUCTOR: {
2436 suffix += ".args";
2437 suffix += hasTypeArgs ? ".params" : "";
2438 }
2439 }
2440 return key + suffix;
2441 }
2442 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
2443 if (location.kind == VAR) {
2444 return diags.fragment("location.1",
2445 kindName(location),
2446 location,
2447 location.type);
2448 } else {
2449 return diags.fragment("location",
2450 typeKindName(site),
2451 site,
2452 null);
2453 }
2454 }
2455 }
2457 /**
2458 * InvalidSymbolError error class indicating that a given symbol
2459 * (either a method, a constructor or an operand) is not applicable
2460 * given an actual arguments/type argument list.
2461 */
2462 class InapplicableSymbolError extends ResolveError {
2464 InapplicableSymbolError() {
2465 super(WRONG_MTH, "inapplicable symbol error");
2466 }
2468 protected InapplicableSymbolError(int kind, String debugName) {
2469 super(kind, debugName);
2470 }
2472 @Override
2473 public String toString() {
2474 return super.toString();
2475 }
2477 @Override
2478 public boolean exists() {
2479 return true;
2480 }
2482 @Override
2483 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2484 DiagnosticPosition pos,
2485 Symbol location,
2486 Type site,
2487 Name name,
2488 List<Type> argtypes,
2489 List<Type> typeargtypes) {
2490 if (name == names.error)
2491 return null;
2493 if (isOperator(name)) {
2494 boolean isUnaryOp = argtypes.size() == 1;
2495 String key = argtypes.size() == 1 ?
2496 "operator.cant.be.applied" :
2497 "operator.cant.be.applied.1";
2498 Type first = argtypes.head;
2499 Type second = !isUnaryOp ? argtypes.tail.head : null;
2500 return diags.create(dkind, log.currentSource(), pos,
2501 key, name, first, second);
2502 }
2503 else {
2504 Candidate c = errCandidate();
2505 Symbol ws = c.sym.asMemberOf(site, types);
2506 return diags.create(dkind, log.currentSource(), pos,
2507 "cant.apply.symbol" + (c.details != null ? ".1" : ""),
2508 kindName(ws),
2509 ws.name == names.init ? ws.owner.name : ws.name,
2510 methodArguments(ws.type.getParameterTypes()),
2511 methodArguments(argtypes),
2512 kindName(ws.owner),
2513 ws.owner.type,
2514 c.details);
2515 }
2516 }
2518 @Override
2519 public Symbol access(Name name, TypeSymbol location) {
2520 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
2521 }
2523 protected boolean shouldReport(Candidate c) {
2524 return !c.isApplicable() &&
2525 (((c.sym.flags() & VARARGS) != 0 && c.step == VARARITY) ||
2526 (c.sym.flags() & VARARGS) == 0 && c.step == (boxingEnabled ? BOX : BASIC));
2527 }
2529 private Candidate errCandidate() {
2530 for (Candidate c : currentResolutionContext.candidates) {
2531 if (shouldReport(c)) {
2532 return c;
2533 }
2534 }
2535 Assert.error();
2536 return null;
2537 }
2538 }
2540 /**
2541 * ResolveError error class indicating that a set of symbols
2542 * (either methods, constructors or operands) is not applicable
2543 * given an actual arguments/type argument list.
2544 */
2545 class InapplicableSymbolsError extends InapplicableSymbolError {
2547 InapplicableSymbolsError() {
2548 super(WRONG_MTHS, "inapplicable symbols");
2549 }
2551 @Override
2552 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2553 DiagnosticPosition pos,
2554 Symbol location,
2555 Type site,
2556 Name name,
2557 List<Type> argtypes,
2558 List<Type> typeargtypes) {
2559 if (currentResolutionContext.candidates.nonEmpty()) {
2560 JCDiagnostic err = diags.create(dkind,
2561 log.currentSource(),
2562 pos,
2563 "cant.apply.symbols",
2564 name == names.init ? KindName.CONSTRUCTOR : absentKind(kind),
2565 getName(),
2566 argtypes);
2567 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(site));
2568 } else {
2569 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
2570 location, site, name, argtypes, typeargtypes);
2571 }
2572 }
2574 //where
2575 List<JCDiagnostic> candidateDetails(Type site) {
2576 List<JCDiagnostic> details = List.nil();
2577 for (Candidate c : currentResolutionContext.candidates) {
2578 if (!shouldReport(c)) continue;
2579 JCDiagnostic detailDiag = diags.fragment("inapplicable.method",
2580 Kinds.kindName(c.sym),
2581 c.sym.location(site, types),
2582 c.sym.asMemberOf(site, types),
2583 c.details);
2584 details = details.prepend(detailDiag);
2585 }
2586 return details.reverse();
2587 }
2589 private Name getName() {
2590 Symbol sym = currentResolutionContext.candidates.head.sym;
2591 return sym.name == names.init ?
2592 sym.owner.name :
2593 sym.name;
2594 }
2595 }
2597 /**
2598 * An InvalidSymbolError error class indicating that a symbol is not
2599 * accessible from a given site
2600 */
2601 class AccessError extends InvalidSymbolError {
2603 private Env<AttrContext> env;
2604 private Type site;
2606 AccessError(Symbol sym) {
2607 this(null, null, sym);
2608 }
2610 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
2611 super(HIDDEN, sym, "access error");
2612 this.env = env;
2613 this.site = site;
2614 if (debugResolve)
2615 log.error("proc.messager", sym + " @ " + site + " is inaccessible.");
2616 }
2618 @Override
2619 public boolean exists() {
2620 return false;
2621 }
2623 @Override
2624 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2625 DiagnosticPosition pos,
2626 Symbol location,
2627 Type site,
2628 Name name,
2629 List<Type> argtypes,
2630 List<Type> typeargtypes) {
2631 if (sym.owner.type.tag == ERROR)
2632 return null;
2634 if (sym.name == names.init && sym.owner != site.tsym) {
2635 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
2636 pos, location, site, name, argtypes, typeargtypes);
2637 }
2638 else if ((sym.flags() & PUBLIC) != 0
2639 || (env != null && this.site != null
2640 && !isAccessible(env, this.site))) {
2641 return diags.create(dkind, log.currentSource(),
2642 pos, "not.def.access.class.intf.cant.access",
2643 sym, sym.location());
2644 }
2645 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
2646 return diags.create(dkind, log.currentSource(),
2647 pos, "report.access", sym,
2648 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
2649 sym.location());
2650 }
2651 else {
2652 return diags.create(dkind, log.currentSource(),
2653 pos, "not.def.public.cant.access", sym, sym.location());
2654 }
2655 }
2656 }
2658 /**
2659 * InvalidSymbolError error class indicating that an instance member
2660 * has erroneously been accessed from a static context.
2661 */
2662 class StaticError extends InvalidSymbolError {
2664 StaticError(Symbol sym) {
2665 super(STATICERR, sym, "static error");
2666 }
2668 @Override
2669 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2670 DiagnosticPosition pos,
2671 Symbol location,
2672 Type site,
2673 Name name,
2674 List<Type> argtypes,
2675 List<Type> typeargtypes) {
2676 Symbol errSym = ((sym.kind == TYP && sym.type.tag == CLASS)
2677 ? types.erasure(sym.type).tsym
2678 : sym);
2679 return diags.create(dkind, log.currentSource(), pos,
2680 "non-static.cant.be.ref", kindName(sym), errSym);
2681 }
2682 }
2684 /**
2685 * InvalidSymbolError error class indicating that a pair of symbols
2686 * (either methods, constructors or operands) are ambiguous
2687 * given an actual arguments/type argument list.
2688 */
2689 class AmbiguityError extends InvalidSymbolError {
2691 /** The other maximally specific symbol */
2692 Symbol sym2;
2694 AmbiguityError(Symbol sym1, Symbol sym2) {
2695 super(AMBIGUOUS, sym1, "ambiguity error");
2696 this.sym2 = sym2;
2697 }
2699 @Override
2700 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2701 DiagnosticPosition pos,
2702 Symbol location,
2703 Type site,
2704 Name name,
2705 List<Type> argtypes,
2706 List<Type> typeargtypes) {
2707 AmbiguityError pair = this;
2708 while (true) {
2709 if (pair.sym.kind == AMBIGUOUS)
2710 pair = (AmbiguityError)pair.sym;
2711 else if (pair.sym2.kind == AMBIGUOUS)
2712 pair = (AmbiguityError)pair.sym2;
2713 else break;
2714 }
2715 Name sname = pair.sym.name;
2716 if (sname == names.init) sname = pair.sym.owner.name;
2717 return diags.create(dkind, log.currentSource(),
2718 pos, "ref.ambiguous", sname,
2719 kindName(pair.sym),
2720 pair.sym,
2721 pair.sym.location(site, types),
2722 kindName(pair.sym2),
2723 pair.sym2,
2724 pair.sym2.location(site, types));
2725 }
2726 }
2728 enum MethodResolutionPhase {
2729 BASIC(false, false),
2730 BOX(true, false),
2731 VARARITY(true, true);
2733 boolean isBoxingRequired;
2734 boolean isVarargsRequired;
2736 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
2737 this.isBoxingRequired = isBoxingRequired;
2738 this.isVarargsRequired = isVarargsRequired;
2739 }
2741 public boolean isBoxingRequired() {
2742 return isBoxingRequired;
2743 }
2745 public boolean isVarargsRequired() {
2746 return isVarargsRequired;
2747 }
2749 public boolean isApplicable(boolean boxingEnabled, boolean varargsEnabled) {
2750 return (varargsEnabled || !isVarargsRequired) &&
2751 (boxingEnabled || !isBoxingRequired);
2752 }
2753 }
2755 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
2757 /**
2758 * A resolution context is used to keep track of intermediate results of
2759 * overload resolution, such as list of method that are not applicable
2760 * (used to generate more precise diagnostics) and so on. Resolution contexts
2761 * can be nested - this means that when each overload resolution routine should
2762 * work within the resolution context it created.
2763 */
2764 class MethodResolutionContext {
2766 private List<Candidate> candidates = List.nil();
2768 private Map<MethodResolutionPhase, Symbol> resolutionCache =
2769 new EnumMap<MethodResolutionPhase, Symbol>(MethodResolutionPhase.class);
2771 private MethodResolutionPhase step = null;
2773 private boolean internalResolution = false;
2775 private MethodResolutionPhase firstErroneousResolutionPhase() {
2776 MethodResolutionPhase bestSoFar = BASIC;
2777 Symbol sym = methodNotFound;
2778 List<MethodResolutionPhase> steps = methodResolutionSteps;
2779 while (steps.nonEmpty() &&
2780 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
2781 sym.kind >= WRONG_MTHS) {
2782 sym = resolutionCache.get(steps.head);
2783 bestSoFar = steps.head;
2784 steps = steps.tail;
2785 }
2786 return bestSoFar;
2787 }
2789 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) {
2790 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null);
2791 if (!candidates.contains(c))
2792 candidates = candidates.append(c);
2793 }
2795 void addApplicableCandidate(Symbol sym, Type mtype) {
2796 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype);
2797 candidates = candidates.append(c);
2798 }
2800 /**
2801 * This class represents an overload resolution candidate. There are two
2802 * kinds of candidates: applicable methods and inapplicable methods;
2803 * applicable methods have a pointer to the instantiated method type,
2804 * while inapplicable candidates contain further details about the
2805 * reason why the method has been considered inapplicable.
2806 */
2807 class Candidate {
2809 final MethodResolutionPhase step;
2810 final Symbol sym;
2811 final JCDiagnostic details;
2812 final Type mtype;
2814 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) {
2815 this.step = step;
2816 this.sym = sym;
2817 this.details = details;
2818 this.mtype = mtype;
2819 }
2821 @Override
2822 public boolean equals(Object o) {
2823 if (o instanceof Candidate) {
2824 Symbol s1 = this.sym;
2825 Symbol s2 = ((Candidate)o).sym;
2826 if ((s1 != s2 &&
2827 (s1.overrides(s2, s1.owner.type.tsym, types, false) ||
2828 (s2.overrides(s1, s2.owner.type.tsym, types, false)))) ||
2829 ((s1.isConstructor() || s2.isConstructor()) && s1.owner != s2.owner))
2830 return true;
2831 }
2832 return false;
2833 }
2835 boolean isApplicable() {
2836 return mtype != null;
2837 }
2838 }
2839 }
2841 MethodResolutionContext currentResolutionContext = null;
2842 }
