Mercurial > jdk8-mips64-public > langtools / file revision
src/share/classes/com/sun/tools/javac/comp/Resolve.java@84a18d7da478
src/share/classes/com/sun/tools/javac/comp/Resolve.java
Thu, 05 Mar 2009 17:24:40 +0000
- author
- mcimadamore
- date
- Thu, 05 Mar 2009 17:24:40 +0000
- changeset 236
- 84a18d7da478
- parent 171
- 1d1f34b36535
- child 254
- 1ee128971f5d
- permissions
- -rw-r--r--
6804733: javac generates spourious diagnostics for ill-formed type-variable bounds
Summary: fixed algorithm for checking cycles in typevar declarations
Reviewed-by: jjg
1 /*
2 * Copyright 1999-2008 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
26 package com.sun.tools.javac.comp;
28 import com.sun.tools.javac.util.*;
29 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
30 import com.sun.tools.javac.code.*;
31 import com.sun.tools.javac.jvm.*;
32 import com.sun.tools.javac.tree.*;
33 import com.sun.tools.javac.api.Formattable.LocalizedString;
34 import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*;
36 import com.sun.tools.javac.code.Type.*;
37 import com.sun.tools.javac.code.Symbol.*;
38 import com.sun.tools.javac.tree.JCTree.*;
40 import static com.sun.tools.javac.code.Flags.*;
41 import static com.sun.tools.javac.code.Kinds.*;
42 import static com.sun.tools.javac.code.TypeTags.*;
43 import javax.lang.model.element.ElementVisitor;
45 import java.util.Map;
46 import java.util.HashMap;
48 /** Helper class for name resolution, used mostly by the attribution phase.
49 *
50 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
51 * you write code that depends on this, you do so at your own risk.
52 * This code and its internal interfaces are subject to change or
53 * deletion without notice.</b>
54 */
55 public class Resolve {
56 protected static final Context.Key<Resolve> resolveKey =
57 new Context.Key<Resolve>();
59 Names names;
60 Log log;
61 Symtab syms;
62 Check chk;
63 Infer infer;
64 ClassReader reader;
65 TreeInfo treeinfo;
66 Types types;
67 JCDiagnostic.Factory diags;
68 public final boolean boxingEnabled; // = source.allowBoxing();
69 public final boolean varargsEnabled; // = source.allowVarargs();
70 private final boolean debugResolve;
72 public static Resolve instance(Context context) {
73 Resolve instance = context.get(resolveKey);
74 if (instance == null)
75 instance = new Resolve(context);
76 return instance;
77 }
79 protected Resolve(Context context) {
80 context.put(resolveKey, this);
81 syms = Symtab.instance(context);
83 varNotFound = new
84 ResolveError(ABSENT_VAR, syms.errSymbol, "variable not found");
85 wrongMethod = new
86 ResolveError(WRONG_MTH, syms.errSymbol, "method not found");
87 wrongMethods = new
88 ResolveError(WRONG_MTHS, syms.errSymbol, "wrong methods");
89 methodNotFound = new
90 ResolveError(ABSENT_MTH, syms.errSymbol, "method not found");
91 typeNotFound = new
92 ResolveError(ABSENT_TYP, syms.errSymbol, "type not found");
94 names = Names.instance(context);
95 log = Log.instance(context);
96 chk = Check.instance(context);
97 infer = Infer.instance(context);
98 reader = ClassReader.instance(context);
99 treeinfo = TreeInfo.instance(context);
100 types = Types.instance(context);
101 diags = JCDiagnostic.Factory.instance(context);
102 Source source = Source.instance(context);
103 boxingEnabled = source.allowBoxing();
104 varargsEnabled = source.allowVarargs();
105 Options options = Options.instance(context);
106 debugResolve = options.get("debugresolve") != null;
107 }
109 /** error symbols, which are returned when resolution fails
110 */
111 final ResolveError varNotFound;
112 final ResolveError wrongMethod;
113 final ResolveError wrongMethods;
114 final ResolveError methodNotFound;
115 final ResolveError typeNotFound;
117 /* ************************************************************************
118 * Identifier resolution
119 *************************************************************************/
121 /** An environment is "static" if its static level is greater than
122 * the one of its outer environment
123 */
124 static boolean isStatic(Env<AttrContext> env) {
125 return env.info.staticLevel > env.outer.info.staticLevel;
126 }
128 /** An environment is an "initializer" if it is a constructor or
129 * an instance initializer.
130 */
131 static boolean isInitializer(Env<AttrContext> env) {
132 Symbol owner = env.info.scope.owner;
133 return owner.isConstructor() ||
134 owner.owner.kind == TYP &&
135 (owner.kind == VAR ||
136 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
137 (owner.flags() & STATIC) == 0;
138 }
140 /** Is class accessible in given evironment?
141 * @param env The current environment.
142 * @param c The class whose accessibility is checked.
143 */
144 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
145 switch ((short)(c.flags() & AccessFlags)) {
146 case PRIVATE:
147 return
148 env.enclClass.sym.outermostClass() ==
149 c.owner.outermostClass();
150 case 0:
151 return
152 env.toplevel.packge == c.owner // fast special case
153 ||
154 env.toplevel.packge == c.packge()
155 ||
156 // Hack: this case is added since synthesized default constructors
157 // of anonymous classes should be allowed to access
158 // classes which would be inaccessible otherwise.
159 env.enclMethod != null &&
160 (env.enclMethod.mods.flags & ANONCONSTR) != 0;
161 default: // error recovery
162 case PUBLIC:
163 return true;
164 case PROTECTED:
165 return
166 env.toplevel.packge == c.owner // fast special case
167 ||
168 env.toplevel.packge == c.packge()
169 ||
170 isInnerSubClass(env.enclClass.sym, c.owner);
171 }
172 }
173 //where
174 /** Is given class a subclass of given base class, or an inner class
175 * of a subclass?
176 * Return null if no such class exists.
177 * @param c The class which is the subclass or is contained in it.
178 * @param base The base class
179 */
180 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
181 while (c != null && !c.isSubClass(base, types)) {
182 c = c.owner.enclClass();
183 }
184 return c != null;
185 }
187 boolean isAccessible(Env<AttrContext> env, Type t) {
188 return (t.tag == ARRAY)
189 ? isAccessible(env, types.elemtype(t))
190 : isAccessible(env, t.tsym);
191 }
193 /** Is symbol accessible as a member of given type in given evironment?
194 * @param env The current environment.
195 * @param site The type of which the tested symbol is regarded
196 * as a member.
197 * @param sym The symbol.
198 */
199 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
200 if (sym.name == names.init && sym.owner != site.tsym) return false;
201 ClassSymbol sub;
202 switch ((short)(sym.flags() & AccessFlags)) {
203 case PRIVATE:
204 return
205 (env.enclClass.sym == sym.owner // fast special case
206 ||
207 env.enclClass.sym.outermostClass() ==
208 sym.owner.outermostClass())
209 &&
210 sym.isInheritedIn(site.tsym, types);
211 case 0:
212 return
213 (env.toplevel.packge == sym.owner.owner // fast special case
214 ||
215 env.toplevel.packge == sym.packge())
216 &&
217 isAccessible(env, site)
218 &&
219 sym.isInheritedIn(site.tsym, types);
220 case PROTECTED:
221 return
222 (env.toplevel.packge == sym.owner.owner // fast special case
223 ||
224 env.toplevel.packge == sym.packge()
225 ||
226 isProtectedAccessible(sym, env.enclClass.sym, site)
227 ||
228 // OK to select instance method or field from 'super' or type name
229 // (but type names should be disallowed elsewhere!)
230 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
231 &&
232 isAccessible(env, site)
233 &&
234 // `sym' is accessible only if not overridden by
235 // another symbol which is a member of `site'
236 // (because, if it is overridden, `sym' is not strictly
237 // speaking a member of `site'.)
238 (sym.kind != MTH || sym.isConstructor() || sym.isStatic() ||
239 ((MethodSymbol)sym).implementation(site.tsym, types, true) == sym);
240 default: // this case includes erroneous combinations as well
241 return isAccessible(env, site);
242 }
243 }
244 //where
245 /** Is given protected symbol accessible if it is selected from given site
246 * and the selection takes place in given class?
247 * @param sym The symbol with protected access
248 * @param c The class where the access takes place
249 * @site The type of the qualifier
250 */
251 private
252 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
253 while (c != null &&
254 !(c.isSubClass(sym.owner, types) &&
255 (c.flags() & INTERFACE) == 0 &&
256 // In JLS 2e 6.6.2.1, the subclass restriction applies
257 // only to instance fields and methods -- types are excluded
258 // regardless of whether they are declared 'static' or not.
259 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || site.tsym.isSubClass(c, types))))
260 c = c.owner.enclClass();
261 return c != null;
262 }
264 /** Try to instantiate the type of a method so that it fits
265 * given type arguments and argument types. If succesful, return
266 * the method's instantiated type, else return null.
267 * The instantiation will take into account an additional leading
268 * formal parameter if the method is an instance method seen as a member
269 * of un underdetermined site In this case, we treat site as an additional
270 * parameter and the parameters of the class containing the method as
271 * additional type variables that get instantiated.
272 *
273 * @param env The current environment
274 * @param site The type of which the method is a member.
275 * @param m The method symbol.
276 * @param argtypes The invocation's given value arguments.
277 * @param typeargtypes The invocation's given type arguments.
278 * @param allowBoxing Allow boxing conversions of arguments.
279 * @param useVarargs Box trailing arguments into an array for varargs.
280 */
281 Type rawInstantiate(Env<AttrContext> env,
282 Type site,
283 Symbol m,
284 List<Type> argtypes,
285 List<Type> typeargtypes,
286 boolean allowBoxing,
287 boolean useVarargs,
288 Warner warn)
289 throws Infer.NoInstanceException {
290 if (useVarargs && (m.flags() & VARARGS) == 0) return null;
291 Type mt = types.memberType(site, m);
293 // tvars is the list of formal type variables for which type arguments
294 // need to inferred.
295 List<Type> tvars = env.info.tvars;
296 if (typeargtypes == null) typeargtypes = List.nil();
297 if (mt.tag != FORALL && typeargtypes.nonEmpty()) {
298 // This is not a polymorphic method, but typeargs are supplied
299 // which is fine, see JLS3 15.12.2.1
300 } else if (mt.tag == FORALL && typeargtypes.nonEmpty()) {
301 ForAll pmt = (ForAll) mt;
302 if (typeargtypes.length() != pmt.tvars.length())
303 return null;
304 // Check type arguments are within bounds
305 List<Type> formals = pmt.tvars;
306 List<Type> actuals = typeargtypes;
307 while (formals.nonEmpty() && actuals.nonEmpty()) {
308 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
309 pmt.tvars, typeargtypes);
310 for (; bounds.nonEmpty(); bounds = bounds.tail)
311 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn))
312 return null;
313 formals = formals.tail;
314 actuals = actuals.tail;
315 }
316 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
317 } else if (mt.tag == FORALL) {
318 ForAll pmt = (ForAll) mt;
319 List<Type> tvars1 = types.newInstances(pmt.tvars);
320 tvars = tvars.appendList(tvars1);
321 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
322 }
324 // find out whether we need to go the slow route via infer
325 boolean instNeeded = tvars.tail != null/*inlined: tvars.nonEmpty()*/;
326 for (List<Type> l = argtypes;
327 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
328 l = l.tail) {
329 if (l.head.tag == FORALL) instNeeded = true;
330 }
332 if (instNeeded)
333 return
334 infer.instantiateMethod(tvars,
335 (MethodType)mt,
336 argtypes,
337 allowBoxing,
338 useVarargs,
339 warn);
340 return
341 argumentsAcceptable(argtypes, mt.getParameterTypes(),
342 allowBoxing, useVarargs, warn)
343 ? mt
344 : null;
345 }
347 /** Same but returns null instead throwing a NoInstanceException
348 */
349 Type instantiate(Env<AttrContext> env,
350 Type site,
351 Symbol m,
352 List<Type> argtypes,
353 List<Type> typeargtypes,
354 boolean allowBoxing,
355 boolean useVarargs,
356 Warner warn) {
357 try {
358 return rawInstantiate(env, site, m, argtypes, typeargtypes,
359 allowBoxing, useVarargs, warn);
360 } catch (Infer.NoInstanceException ex) {
361 return null;
362 }
363 }
365 /** Check if a parameter list accepts a list of args.
366 */
367 boolean argumentsAcceptable(List<Type> argtypes,
368 List<Type> formals,
369 boolean allowBoxing,
370 boolean useVarargs,
371 Warner warn) {
372 Type varargsFormal = useVarargs ? formals.last() : null;
373 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
374 boolean works = allowBoxing
375 ? types.isConvertible(argtypes.head, formals.head, warn)
376 : types.isSubtypeUnchecked(argtypes.head, formals.head, warn);
377 if (!works) return false;
378 argtypes = argtypes.tail;
379 formals = formals.tail;
380 }
381 if (formals.head != varargsFormal) return false; // not enough args
382 if (!useVarargs)
383 return argtypes.isEmpty();
384 Type elt = types.elemtype(varargsFormal);
385 while (argtypes.nonEmpty()) {
386 if (!types.isConvertible(argtypes.head, elt, warn))
387 return false;
388 argtypes = argtypes.tail;
389 }
390 return true;
391 }
393 /* ***************************************************************************
394 * Symbol lookup
395 * the following naming conventions for arguments are used
396 *
397 * env is the environment where the symbol was mentioned
398 * site is the type of which the symbol is a member
399 * name is the symbol's name
400 * if no arguments are given
401 * argtypes are the value arguments, if we search for a method
402 *
403 * If no symbol was found, a ResolveError detailing the problem is returned.
404 ****************************************************************************/
406 /** Find field. Synthetic fields are always skipped.
407 * @param env The current environment.
408 * @param site The original type from where the selection takes place.
409 * @param name The name of the field.
410 * @param c The class to search for the field. This is always
411 * a superclass or implemented interface of site's class.
412 */
413 Symbol findField(Env<AttrContext> env,
414 Type site,
415 Name name,
416 TypeSymbol c) {
417 while (c.type.tag == TYPEVAR)
418 c = c.type.getUpperBound().tsym;
419 Symbol bestSoFar = varNotFound;
420 Symbol sym;
421 Scope.Entry e = c.members().lookup(name);
422 while (e.scope != null) {
423 if (e.sym.kind == VAR && (e.sym.flags_field & SYNTHETIC) == 0) {
424 return isAccessible(env, site, e.sym)
425 ? e.sym : new AccessError(env, site, e.sym);
426 }
427 e = e.next();
428 }
429 Type st = types.supertype(c.type);
430 if (st != null && (st.tag == CLASS || st.tag == TYPEVAR)) {
431 sym = findField(env, site, name, st.tsym);
432 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
433 }
434 for (List<Type> l = types.interfaces(c.type);
435 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
436 l = l.tail) {
437 sym = findField(env, site, name, l.head.tsym);
438 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
439 sym.owner != bestSoFar.owner)
440 bestSoFar = new AmbiguityError(bestSoFar, sym);
441 else if (sym.kind < bestSoFar.kind)
442 bestSoFar = sym;
443 }
444 return bestSoFar;
445 }
447 /** Resolve a field identifier, throw a fatal error if not found.
448 * @param pos The position to use for error reporting.
449 * @param env The environment current at the method invocation.
450 * @param site The type of the qualifying expression, in which
451 * identifier is searched.
452 * @param name The identifier's name.
453 */
454 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
455 Type site, Name name) {
456 Symbol sym = findField(env, site, name, site.tsym);
457 if (sym.kind == VAR) return (VarSymbol)sym;
458 else throw new FatalError(
459 diags.fragment("fatal.err.cant.locate.field",
460 name));
461 }
463 /** Find unqualified variable or field with given name.
464 * Synthetic fields always skipped.
465 * @param env The current environment.
466 * @param name The name of the variable or field.
467 */
468 Symbol findVar(Env<AttrContext> env, Name name) {
469 Symbol bestSoFar = varNotFound;
470 Symbol sym;
471 Env<AttrContext> env1 = env;
472 boolean staticOnly = false;
473 while (env1.outer != null) {
474 if (isStatic(env1)) staticOnly = true;
475 Scope.Entry e = env1.info.scope.lookup(name);
476 while (e.scope != null &&
477 (e.sym.kind != VAR ||
478 (e.sym.flags_field & SYNTHETIC) != 0))
479 e = e.next();
480 sym = (e.scope != null)
481 ? e.sym
482 : findField(
483 env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
484 if (sym.exists()) {
485 if (staticOnly &&
486 sym.kind == VAR &&
487 sym.owner.kind == TYP &&
488 (sym.flags() & STATIC) == 0)
489 return new StaticError(sym);
490 else
491 return sym;
492 } else if (sym.kind < bestSoFar.kind) {
493 bestSoFar = sym;
494 }
496 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
497 env1 = env1.outer;
498 }
500 sym = findField(env, syms.predefClass.type, name, syms.predefClass);
501 if (sym.exists())
502 return sym;
503 if (bestSoFar.exists())
504 return bestSoFar;
506 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
507 for (; e.scope != null; e = e.next()) {
508 sym = e.sym;
509 Type origin = e.getOrigin().owner.type;
510 if (sym.kind == VAR) {
511 if (e.sym.owner.type != origin)
512 sym = sym.clone(e.getOrigin().owner);
513 return isAccessible(env, origin, sym)
514 ? sym : new AccessError(env, origin, sym);
515 }
516 }
518 Symbol origin = null;
519 e = env.toplevel.starImportScope.lookup(name);
520 for (; e.scope != null; e = e.next()) {
521 sym = e.sym;
522 if (sym.kind != VAR)
523 continue;
524 // invariant: sym.kind == VAR
525 if (bestSoFar.kind < AMBIGUOUS && sym.owner != bestSoFar.owner)
526 return new AmbiguityError(bestSoFar, sym);
527 else if (bestSoFar.kind >= VAR) {
528 origin = e.getOrigin().owner;
529 bestSoFar = isAccessible(env, origin.type, sym)
530 ? sym : new AccessError(env, origin.type, sym);
531 }
532 }
533 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
534 return bestSoFar.clone(origin);
535 else
536 return bestSoFar;
537 }
539 Warner noteWarner = new Warner();
541 /** Select the best method for a call site among two choices.
542 * @param env The current environment.
543 * @param site The original type from where the
544 * selection takes place.
545 * @param argtypes The invocation's value arguments,
546 * @param typeargtypes The invocation's type arguments,
547 * @param sym Proposed new best match.
548 * @param bestSoFar Previously found best match.
549 * @param allowBoxing Allow boxing conversions of arguments.
550 * @param useVarargs Box trailing arguments into an array for varargs.
551 */
552 Symbol selectBest(Env<AttrContext> env,
553 Type site,
554 List<Type> argtypes,
555 List<Type> typeargtypes,
556 Symbol sym,
557 Symbol bestSoFar,
558 boolean allowBoxing,
559 boolean useVarargs,
560 boolean operator) {
561 if (sym.kind == ERR) return bestSoFar;
562 if (!sym.isInheritedIn(site.tsym, types)) return bestSoFar;
563 assert sym.kind < AMBIGUOUS;
564 try {
565 if (rawInstantiate(env, site, sym, argtypes, typeargtypes,
566 allowBoxing, useVarargs, Warner.noWarnings) == null) {
567 // inapplicable
568 switch (bestSoFar.kind) {
569 case ABSENT_MTH: return wrongMethod.setWrongSym(sym);
570 case WRONG_MTH: return wrongMethods;
571 default: return bestSoFar;
572 }
573 }
574 } catch (Infer.NoInstanceException ex) {
575 switch (bestSoFar.kind) {
576 case ABSENT_MTH:
577 return wrongMethod.setWrongSym(sym, ex.getDiagnostic());
578 case WRONG_MTH:
579 return wrongMethods;
580 default:
581 return bestSoFar;
582 }
583 }
584 if (!isAccessible(env, site, sym)) {
585 return (bestSoFar.kind == ABSENT_MTH)
586 ? new AccessError(env, site, sym)
587 : bestSoFar;
588 }
589 return (bestSoFar.kind > AMBIGUOUS)
590 ? sym
591 : mostSpecific(sym, bestSoFar, env, site,
592 allowBoxing && operator, useVarargs);
593 }
595 /* Return the most specific of the two methods for a call,
596 * given that both are accessible and applicable.
597 * @param m1 A new candidate for most specific.
598 * @param m2 The previous most specific candidate.
599 * @param env The current environment.
600 * @param site The original type from where the selection
601 * takes place.
602 * @param allowBoxing Allow boxing conversions of arguments.
603 * @param useVarargs Box trailing arguments into an array for varargs.
604 */
605 Symbol mostSpecific(Symbol m1,
606 Symbol m2,
607 Env<AttrContext> env,
608 Type site,
609 boolean allowBoxing,
610 boolean useVarargs) {
611 switch (m2.kind) {
612 case MTH:
613 if (m1 == m2) return m1;
614 Type mt1 = types.memberType(site, m1);
615 noteWarner.unchecked = false;
616 boolean m1SignatureMoreSpecific =
617 (instantiate(env, site, m2, types.lowerBoundArgtypes(mt1), null,
618 allowBoxing, false, noteWarner) != null ||
619 useVarargs && instantiate(env, site, m2, types.lowerBoundArgtypes(mt1), null,
620 allowBoxing, true, noteWarner) != null) &&
621 !noteWarner.unchecked;
622 Type mt2 = types.memberType(site, m2);
623 noteWarner.unchecked = false;
624 boolean m2SignatureMoreSpecific =
625 (instantiate(env, site, m1, types.lowerBoundArgtypes(mt2), null,
626 allowBoxing, false, noteWarner) != null ||
627 useVarargs && instantiate(env, site, m1, types.lowerBoundArgtypes(mt2), null,
628 allowBoxing, true, noteWarner) != null) &&
629 !noteWarner.unchecked;
630 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
631 if (!types.overrideEquivalent(mt1, mt2))
632 return new AmbiguityError(m1, m2);
633 // same signature; select (a) the non-bridge method, or
634 // (b) the one that overrides the other, or (c) the concrete
635 // one, or (d) merge both abstract signatures
636 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE)) {
637 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
638 }
639 // if one overrides or hides the other, use it
640 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
641 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
642 if (types.asSuper(m1Owner.type, m2Owner) != null &&
643 ((m1.owner.flags_field & INTERFACE) == 0 ||
644 (m2.owner.flags_field & INTERFACE) != 0) &&
645 m1.overrides(m2, m1Owner, types, false))
646 return m1;
647 if (types.asSuper(m2Owner.type, m1Owner) != null &&
648 ((m2.owner.flags_field & INTERFACE) == 0 ||
649 (m1.owner.flags_field & INTERFACE) != 0) &&
650 m2.overrides(m1, m2Owner, types, false))
651 return m2;
652 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
653 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
654 if (m1Abstract && !m2Abstract) return m2;
655 if (m2Abstract && !m1Abstract) return m1;
656 // both abstract or both concrete
657 if (!m1Abstract && !m2Abstract)
658 return new AmbiguityError(m1, m2);
659 // check that both signatures have the same erasure
660 if (!types.isSameTypes(m1.erasure(types).getParameterTypes(),
661 m2.erasure(types).getParameterTypes()))
662 return new AmbiguityError(m1, m2);
663 // both abstract, neither overridden; merge throws clause and result type
664 Symbol result;
665 Type result2 = mt2.getReturnType();
666 if (mt2.tag == FORALL)
667 result2 = types.subst(result2, ((ForAll)mt2).tvars, ((ForAll)mt1).tvars);
668 if (types.isSubtype(mt1.getReturnType(), result2)) {
669 result = m1;
670 } else if (types.isSubtype(result2, mt1.getReturnType())) {
671 result = m2;
672 } else {
673 // Theoretically, this can't happen, but it is possible
674 // due to error recovery or mixing incompatible class files
675 return new AmbiguityError(m1, m2);
676 }
677 result = result.clone(result.owner);
678 result.type = (Type)result.type.clone();
679 result.type.setThrown(chk.intersect(mt1.getThrownTypes(),
680 mt2.getThrownTypes()));
681 return result;
682 }
683 if (m1SignatureMoreSpecific) return m1;
684 if (m2SignatureMoreSpecific) return m2;
685 return new AmbiguityError(m1, m2);
686 case AMBIGUOUS:
687 AmbiguityError e = (AmbiguityError)m2;
688 Symbol err1 = mostSpecific(m1, e.sym1, env, site, allowBoxing, useVarargs);
689 Symbol err2 = mostSpecific(m1, e.sym2, env, site, allowBoxing, useVarargs);
690 if (err1 == err2) return err1;
691 if (err1 == e.sym1 && err2 == e.sym2) return m2;
692 if (err1 instanceof AmbiguityError &&
693 err2 instanceof AmbiguityError &&
694 ((AmbiguityError)err1).sym1 == ((AmbiguityError)err2).sym1)
695 return new AmbiguityError(m1, m2);
696 else
697 return new AmbiguityError(err1, err2);
698 default:
699 throw new AssertionError();
700 }
701 }
703 /** Find best qualified method matching given name, type and value
704 * arguments.
705 * @param env The current environment.
706 * @param site The original type from where the selection
707 * takes place.
708 * @param name The method's name.
709 * @param argtypes The method's value arguments.
710 * @param typeargtypes The method's type arguments
711 * @param allowBoxing Allow boxing conversions of arguments.
712 * @param useVarargs Box trailing arguments into an array for varargs.
713 */
714 Symbol findMethod(Env<AttrContext> env,
715 Type site,
716 Name name,
717 List<Type> argtypes,
718 List<Type> typeargtypes,
719 boolean allowBoxing,
720 boolean useVarargs,
721 boolean operator) {
722 return findMethod(env,
723 site,
724 name,
725 argtypes,
726 typeargtypes,
727 site.tsym.type,
728 true,
729 methodNotFound,
730 allowBoxing,
731 useVarargs,
732 operator);
733 }
734 // where
735 private Symbol findMethod(Env<AttrContext> env,
736 Type site,
737 Name name,
738 List<Type> argtypes,
739 List<Type> typeargtypes,
740 Type intype,
741 boolean abstractok,
742 Symbol bestSoFar,
743 boolean allowBoxing,
744 boolean useVarargs,
745 boolean operator) {
746 for (Type ct = intype; ct.tag == CLASS || ct.tag == TYPEVAR; ct = types.supertype(ct)) {
747 while (ct.tag == TYPEVAR)
748 ct = ct.getUpperBound();
749 ClassSymbol c = (ClassSymbol)ct.tsym;
750 if ((c.flags() & (ABSTRACT | INTERFACE | ENUM)) == 0)
751 abstractok = false;
752 for (Scope.Entry e = c.members().lookup(name);
753 e.scope != null;
754 e = e.next()) {
755 //- System.out.println(" e " + e.sym);
756 if (e.sym.kind == MTH &&
757 (e.sym.flags_field & SYNTHETIC) == 0) {
758 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
759 e.sym, bestSoFar,
760 allowBoxing,
761 useVarargs,
762 operator);
763 }
764 }
765 //- System.out.println(" - " + bestSoFar);
766 if (abstractok) {
767 Symbol concrete = methodNotFound;
768 if ((bestSoFar.flags() & ABSTRACT) == 0)
769 concrete = bestSoFar;
770 for (List<Type> l = types.interfaces(c.type);
771 l.nonEmpty();
772 l = l.tail) {
773 bestSoFar = findMethod(env, site, name, argtypes,
774 typeargtypes,
775 l.head, abstractok, bestSoFar,
776 allowBoxing, useVarargs, operator);
777 }
778 if (concrete != bestSoFar &&
779 concrete.kind < ERR && bestSoFar.kind < ERR &&
780 types.isSubSignature(concrete.type, bestSoFar.type))
781 bestSoFar = concrete;
782 }
783 }
784 return bestSoFar;
785 }
787 /** Find unqualified method matching given name, type and value arguments.
788 * @param env The current environment.
789 * @param name The method's name.
790 * @param argtypes The method's value arguments.
791 * @param typeargtypes The method's type arguments.
792 * @param allowBoxing Allow boxing conversions of arguments.
793 * @param useVarargs Box trailing arguments into an array for varargs.
794 */
795 Symbol findFun(Env<AttrContext> env, Name name,
796 List<Type> argtypes, List<Type> typeargtypes,
797 boolean allowBoxing, boolean useVarargs) {
798 Symbol bestSoFar = methodNotFound;
799 Symbol sym;
800 Env<AttrContext> env1 = env;
801 boolean staticOnly = false;
802 while (env1.outer != null) {
803 if (isStatic(env1)) staticOnly = true;
804 sym = findMethod(
805 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
806 allowBoxing, useVarargs, false);
807 if (sym.exists()) {
808 if (staticOnly &&
809 sym.kind == MTH &&
810 sym.owner.kind == TYP &&
811 (sym.flags() & STATIC) == 0) return new StaticError(sym);
812 else return sym;
813 } else if (sym.kind < bestSoFar.kind) {
814 bestSoFar = sym;
815 }
816 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
817 env1 = env1.outer;
818 }
820 sym = findMethod(env, syms.predefClass.type, name, argtypes,
821 typeargtypes, allowBoxing, useVarargs, false);
822 if (sym.exists())
823 return sym;
825 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
826 for (; e.scope != null; e = e.next()) {
827 sym = e.sym;
828 Type origin = e.getOrigin().owner.type;
829 if (sym.kind == MTH) {
830 if (e.sym.owner.type != origin)
831 sym = sym.clone(e.getOrigin().owner);
832 if (!isAccessible(env, origin, sym))
833 sym = new AccessError(env, origin, sym);
834 bestSoFar = selectBest(env, origin,
835 argtypes, typeargtypes,
836 sym, bestSoFar,
837 allowBoxing, useVarargs, false);
838 }
839 }
840 if (bestSoFar.exists())
841 return bestSoFar;
843 e = env.toplevel.starImportScope.lookup(name);
844 for (; e.scope != null; e = e.next()) {
845 sym = e.sym;
846 Type origin = e.getOrigin().owner.type;
847 if (sym.kind == MTH) {
848 if (e.sym.owner.type != origin)
849 sym = sym.clone(e.getOrigin().owner);
850 if (!isAccessible(env, origin, sym))
851 sym = new AccessError(env, origin, sym);
852 bestSoFar = selectBest(env, origin,
853 argtypes, typeargtypes,
854 sym, bestSoFar,
855 allowBoxing, useVarargs, false);
856 }
857 }
858 return bestSoFar;
859 }
861 /** Load toplevel or member class with given fully qualified name and
862 * verify that it is accessible.
863 * @param env The current environment.
864 * @param name The fully qualified name of the class to be loaded.
865 */
866 Symbol loadClass(Env<AttrContext> env, Name name) {
867 try {
868 ClassSymbol c = reader.loadClass(name);
869 return isAccessible(env, c) ? c : new AccessError(c);
870 } catch (ClassReader.BadClassFile err) {
871 throw err;
872 } catch (CompletionFailure ex) {
873 return typeNotFound;
874 }
875 }
877 /** Find qualified member type.
878 * @param env The current environment.
879 * @param site The original type from where the selection takes
880 * place.
881 * @param name The type's name.
882 * @param c The class to search for the member type. This is
883 * always a superclass or implemented interface of
884 * site's class.
885 */
886 Symbol findMemberType(Env<AttrContext> env,
887 Type site,
888 Name name,
889 TypeSymbol c) {
890 Symbol bestSoFar = typeNotFound;
891 Symbol sym;
892 Scope.Entry e = c.members().lookup(name);
893 while (e.scope != null) {
894 if (e.sym.kind == TYP) {
895 return isAccessible(env, site, e.sym)
896 ? e.sym
897 : new AccessError(env, site, e.sym);
898 }
899 e = e.next();
900 }
901 Type st = types.supertype(c.type);
902 if (st != null && st.tag == CLASS) {
903 sym = findMemberType(env, site, name, st.tsym);
904 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
905 }
906 for (List<Type> l = types.interfaces(c.type);
907 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
908 l = l.tail) {
909 sym = findMemberType(env, site, name, l.head.tsym);
910 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
911 sym.owner != bestSoFar.owner)
912 bestSoFar = new AmbiguityError(bestSoFar, sym);
913 else if (sym.kind < bestSoFar.kind)
914 bestSoFar = sym;
915 }
916 return bestSoFar;
917 }
919 /** Find a global type in given scope and load corresponding class.
920 * @param env The current environment.
921 * @param scope The scope in which to look for the type.
922 * @param name The type's name.
923 */
924 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) {
925 Symbol bestSoFar = typeNotFound;
926 for (Scope.Entry e = scope.lookup(name); e.scope != null; e = e.next()) {
927 Symbol sym = loadClass(env, e.sym.flatName());
928 if (bestSoFar.kind == TYP && sym.kind == TYP &&
929 bestSoFar != sym)
930 return new AmbiguityError(bestSoFar, sym);
931 else if (sym.kind < bestSoFar.kind)
932 bestSoFar = sym;
933 }
934 return bestSoFar;
935 }
937 /** Find an unqualified type symbol.
938 * @param env The current environment.
939 * @param name The type's name.
940 */
941 Symbol findType(Env<AttrContext> env, Name name) {
942 Symbol bestSoFar = typeNotFound;
943 Symbol sym;
944 boolean staticOnly = false;
945 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
946 if (isStatic(env1)) staticOnly = true;
947 for (Scope.Entry e = env1.info.scope.lookup(name);
948 e.scope != null;
949 e = e.next()) {
950 if (e.sym.kind == TYP) {
951 if (staticOnly &&
952 e.sym.type.tag == TYPEVAR &&
953 e.sym.owner.kind == TYP) return new StaticError(e.sym);
954 return e.sym;
955 }
956 }
958 sym = findMemberType(env1, env1.enclClass.sym.type, name,
959 env1.enclClass.sym);
960 if (staticOnly && sym.kind == TYP &&
961 sym.type.tag == CLASS &&
962 sym.type.getEnclosingType().tag == CLASS &&
963 env1.enclClass.sym.type.isParameterized() &&
964 sym.type.getEnclosingType().isParameterized())
965 return new StaticError(sym);
966 else if (sym.exists()) return sym;
967 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
969 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
970 if ((encl.sym.flags() & STATIC) != 0)
971 staticOnly = true;
972 }
974 if (env.tree.getTag() != JCTree.IMPORT) {
975 sym = findGlobalType(env, env.toplevel.namedImportScope, name);
976 if (sym.exists()) return sym;
977 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
979 sym = findGlobalType(env, env.toplevel.packge.members(), name);
980 if (sym.exists()) return sym;
981 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
983 sym = findGlobalType(env, env.toplevel.starImportScope, name);
984 if (sym.exists()) return sym;
985 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
986 }
988 return bestSoFar;
989 }
991 /** Find an unqualified identifier which matches a specified kind set.
992 * @param env The current environment.
993 * @param name The indentifier's name.
994 * @param kind Indicates the possible symbol kinds
995 * (a subset of VAL, TYP, PCK).
996 */
997 Symbol findIdent(Env<AttrContext> env, Name name, int kind) {
998 Symbol bestSoFar = typeNotFound;
999 Symbol sym;
1001 if ((kind & VAR) != 0) {
1002 sym = findVar(env, name);
1003 if (sym.exists()) return sym;
1004 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1005 }
1007 if ((kind & TYP) != 0) {
1008 sym = findType(env, name);
1009 if (sym.exists()) return sym;
1010 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1011 }
1013 if ((kind & PCK) != 0) return reader.enterPackage(name);
1014 else return bestSoFar;
1015 }
1017 /** Find an identifier in a package which matches a specified kind set.
1018 * @param env The current environment.
1019 * @param name The identifier's name.
1020 * @param kind Indicates the possible symbol kinds
1021 * (a nonempty subset of TYP, PCK).
1022 */
1023 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
1024 Name name, int kind) {
1025 Name fullname = TypeSymbol.formFullName(name, pck);
1026 Symbol bestSoFar = typeNotFound;
1027 PackageSymbol pack = null;
1028 if ((kind & PCK) != 0) {
1029 pack = reader.enterPackage(fullname);
1030 if (pack.exists()) return pack;
1031 }
1032 if ((kind & TYP) != 0) {
1033 Symbol sym = loadClass(env, fullname);
1034 if (sym.exists()) {
1035 // don't allow programs to use flatnames
1036 if (name == sym.name) return sym;
1037 }
1038 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1039 }
1040 return (pack != null) ? pack : bestSoFar;
1041 }
1043 /** Find an identifier among the members of a given type `site'.
1044 * @param env The current environment.
1045 * @param site The type containing the symbol to be found.
1046 * @param name The identifier's name.
1047 * @param kind Indicates the possible symbol kinds
1048 * (a subset of VAL, TYP).
1049 */
1050 Symbol findIdentInType(Env<AttrContext> env, Type site,
1051 Name name, int kind) {
1052 Symbol bestSoFar = typeNotFound;
1053 Symbol sym;
1054 if ((kind & VAR) != 0) {
1055 sym = findField(env, site, name, site.tsym);
1056 if (sym.exists()) return sym;
1057 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1058 }
1060 if ((kind & TYP) != 0) {
1061 sym = findMemberType(env, site, name, site.tsym);
1062 if (sym.exists()) return sym;
1063 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1064 }
1065 return bestSoFar;
1066 }
1068 /* ***************************************************************************
1069 * Access checking
1070 * The following methods convert ResolveErrors to ErrorSymbols, issuing
1071 * an error message in the process
1072 ****************************************************************************/
1074 /** If `sym' is a bad symbol: report error and return errSymbol
1075 * else pass through unchanged,
1076 * additional arguments duplicate what has been used in trying to find the
1077 * symbol (--> flyweight pattern). This improves performance since we
1078 * expect misses to happen frequently.
1079 *
1080 * @param sym The symbol that was found, or a ResolveError.
1081 * @param pos The position to use for error reporting.
1082 * @param site The original type from where the selection took place.
1083 * @param name The symbol's name.
1084 * @param argtypes The invocation's value arguments,
1085 * if we looked for a method.
1086 * @param typeargtypes The invocation's type arguments,
1087 * if we looked for a method.
1088 */
1089 Symbol access(Symbol sym,
1090 DiagnosticPosition pos,
1091 Type site,
1092 Name name,
1093 boolean qualified,
1094 List<Type> argtypes,
1095 List<Type> typeargtypes) {
1096 if (sym.kind >= AMBIGUOUS) {
1097 // printscopes(site.tsym.members());//DEBUG
1098 if (!site.isErroneous() &&
1099 !Type.isErroneous(argtypes) &&
1100 (typeargtypes==null || !Type.isErroneous(typeargtypes)))
1101 ((ResolveError)sym).report(log, pos, site, name, argtypes, typeargtypes);
1102 do {
1103 sym = ((ResolveError)sym).sym;
1104 } while (sym.kind >= AMBIGUOUS);
1105 if (sym == syms.errSymbol // preserve the symbol name through errors
1106 || ((sym.kind & ERRONEOUS) == 0 // make sure an error symbol is returned
1107 && (sym.kind & TYP) != 0))
1108 sym = types.createErrorType(name, qualified ? site.tsym : syms.noSymbol, sym.type).tsym;
1109 }
1110 return sym;
1111 }
1113 /** Same as above, but without type arguments and arguments.
1114 */
1115 Symbol access(Symbol sym,
1116 DiagnosticPosition pos,
1117 Type site,
1118 Name name,
1119 boolean qualified) {
1120 if (sym.kind >= AMBIGUOUS)
1121 return access(sym, pos, site, name, qualified, List.<Type>nil(), null);
1122 else
1123 return sym;
1124 }
1126 /** Check that sym is not an abstract method.
1127 */
1128 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
1129 if ((sym.flags() & ABSTRACT) != 0)
1130 log.error(pos, "abstract.cant.be.accessed.directly",
1131 kindName(sym), sym, sym.location());
1132 }
1134 /* ***************************************************************************
1135 * Debugging
1136 ****************************************************************************/
1138 /** print all scopes starting with scope s and proceeding outwards.
1139 * used for debugging.
1140 */
1141 public void printscopes(Scope s) {
1142 while (s != null) {
1143 if (s.owner != null)
1144 System.err.print(s.owner + ": ");
1145 for (Scope.Entry e = s.elems; e != null; e = e.sibling) {
1146 if ((e.sym.flags() & ABSTRACT) != 0)
1147 System.err.print("abstract ");
1148 System.err.print(e.sym + " ");
1149 }
1150 System.err.println();
1151 s = s.next;
1152 }
1153 }
1155 void printscopes(Env<AttrContext> env) {
1156 while (env.outer != null) {
1157 System.err.println("------------------------------");
1158 printscopes(env.info.scope);
1159 env = env.outer;
1160 }
1161 }
1163 public void printscopes(Type t) {
1164 while (t.tag == CLASS) {
1165 printscopes(t.tsym.members());
1166 t = types.supertype(t);
1167 }
1168 }
1170 /* ***************************************************************************
1171 * Name resolution
1172 * Naming conventions are as for symbol lookup
1173 * Unlike the find... methods these methods will report access errors
1174 ****************************************************************************/
1176 /** Resolve an unqualified (non-method) identifier.
1177 * @param pos The position to use for error reporting.
1178 * @param env The environment current at the identifier use.
1179 * @param name The identifier's name.
1180 * @param kind The set of admissible symbol kinds for the identifier.
1181 */
1182 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
1183 Name name, int kind) {
1184 return access(
1185 findIdent(env, name, kind),
1186 pos, env.enclClass.sym.type, name, false);
1187 }
1189 /** Resolve an unqualified method identifier.
1190 * @param pos The position to use for error reporting.
1191 * @param env The environment current at the method invocation.
1192 * @param name The identifier's name.
1193 * @param argtypes The types of the invocation's value arguments.
1194 * @param typeargtypes The types of the invocation's type arguments.
1195 */
1196 Symbol resolveMethod(DiagnosticPosition pos,
1197 Env<AttrContext> env,
1198 Name name,
1199 List<Type> argtypes,
1200 List<Type> typeargtypes) {
1201 Symbol sym = methodNotFound;
1202 List<MethodResolutionPhase> steps = methodResolutionSteps;
1203 while (steps.nonEmpty() &&
1204 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1205 sym.kind >= ERRONEOUS) {
1206 sym = findFun(env, name, argtypes, typeargtypes,
1207 steps.head.isBoxingRequired,
1208 env.info.varArgs = steps.head.isVarargsRequired);
1209 methodResolutionCache.put(steps.head, sym);
1210 steps = steps.tail;
1211 }
1212 if (sym.kind >= AMBIGUOUS) {//if nothing is found return the 'first' error
1213 MethodResolutionPhase errPhase =
1214 firstErroneousResolutionPhase();
1215 sym = access(methodResolutionCache.get(errPhase),
1216 pos, env.enclClass.sym.type, name, false, argtypes, typeargtypes);
1217 env.info.varArgs = errPhase.isVarargsRequired;
1218 }
1219 return sym;
1220 }
1222 /** Resolve a qualified method identifier
1223 * @param pos The position to use for error reporting.
1224 * @param env The environment current at the method invocation.
1225 * @param site The type of the qualifying expression, in which
1226 * identifier is searched.
1227 * @param name The identifier's name.
1228 * @param argtypes The types of the invocation's value arguments.
1229 * @param typeargtypes The types of the invocation's type arguments.
1230 */
1231 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
1232 Type site, Name name, List<Type> argtypes,
1233 List<Type> typeargtypes) {
1234 Symbol sym = methodNotFound;
1235 List<MethodResolutionPhase> steps = methodResolutionSteps;
1236 while (steps.nonEmpty() &&
1237 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1238 sym.kind >= ERRONEOUS) {
1239 sym = findMethod(env, site, name, argtypes, typeargtypes,
1240 steps.head.isBoxingRequired(),
1241 env.info.varArgs = steps.head.isVarargsRequired(), false);
1242 methodResolutionCache.put(steps.head, sym);
1243 steps = steps.tail;
1244 }
1245 if (sym.kind >= AMBIGUOUS) {//if nothing is found return the 'first' error
1246 MethodResolutionPhase errPhase =
1247 firstErroneousResolutionPhase();
1248 sym = access(methodResolutionCache.get(errPhase),
1249 pos, site, name, true, argtypes, typeargtypes);
1250 env.info.varArgs = errPhase.isVarargsRequired;
1251 }
1252 return sym;
1253 }
1255 /** Resolve a qualified method identifier, throw a fatal error if not
1256 * found.
1257 * @param pos The position to use for error reporting.
1258 * @param env The environment current at the method invocation.
1259 * @param site The type of the qualifying expression, in which
1260 * identifier is searched.
1261 * @param name The identifier's name.
1262 * @param argtypes The types of the invocation's value arguments.
1263 * @param typeargtypes The types of the invocation's type arguments.
1264 */
1265 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
1266 Type site, Name name,
1267 List<Type> argtypes,
1268 List<Type> typeargtypes) {
1269 Symbol sym = resolveQualifiedMethod(
1270 pos, env, site, name, argtypes, typeargtypes);
1271 if (sym.kind == MTH) return (MethodSymbol)sym;
1272 else throw new FatalError(
1273 diags.fragment("fatal.err.cant.locate.meth",
1274 name));
1275 }
1277 /** Resolve constructor.
1278 * @param pos The position to use for error reporting.
1279 * @param env The environment current at the constructor invocation.
1280 * @param site The type of class for which a constructor is searched.
1281 * @param argtypes The types of the constructor invocation's value
1282 * arguments.
1283 * @param typeargtypes The types of the constructor invocation's type
1284 * arguments.
1285 */
1286 Symbol resolveConstructor(DiagnosticPosition pos,
1287 Env<AttrContext> env,
1288 Type site,
1289 List<Type> argtypes,
1290 List<Type> typeargtypes) {
1291 Symbol sym = methodNotFound;
1292 List<MethodResolutionPhase> steps = methodResolutionSteps;
1293 while (steps.nonEmpty() &&
1294 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1295 sym.kind >= ERRONEOUS) {
1296 sym = resolveConstructor(pos, env, site, argtypes, typeargtypes,
1297 steps.head.isBoxingRequired(),
1298 env.info.varArgs = steps.head.isVarargsRequired());
1299 methodResolutionCache.put(steps.head, sym);
1300 steps = steps.tail;
1301 }
1302 if (sym.kind >= AMBIGUOUS) {//if nothing is found return the 'first' error
1303 MethodResolutionPhase errPhase = firstErroneousResolutionPhase();
1304 sym = access(methodResolutionCache.get(errPhase),
1305 pos, site, names.init, true, argtypes, typeargtypes);
1306 env.info.varArgs = errPhase.isVarargsRequired();
1307 }
1308 return sym;
1309 }
1311 /** Resolve constructor.
1312 * @param pos The position to use for error reporting.
1313 * @param env The environment current at the constructor invocation.
1314 * @param site The type of class for which a constructor is searched.
1315 * @param argtypes The types of the constructor invocation's value
1316 * arguments.
1317 * @param typeargtypes The types of the constructor invocation's type
1318 * arguments.
1319 * @param allowBoxing Allow boxing and varargs conversions.
1320 * @param useVarargs Box trailing arguments into an array for varargs.
1321 */
1322 Symbol resolveConstructor(DiagnosticPosition pos, Env<AttrContext> env,
1323 Type site, List<Type> argtypes,
1324 List<Type> typeargtypes,
1325 boolean allowBoxing,
1326 boolean useVarargs) {
1327 Symbol sym = findMethod(env, site,
1328 names.init, argtypes,
1329 typeargtypes, allowBoxing,
1330 useVarargs, false);
1331 if ((sym.flags() & DEPRECATED) != 0 &&
1332 (env.info.scope.owner.flags() & DEPRECATED) == 0 &&
1333 env.info.scope.owner.outermostClass() != sym.outermostClass())
1334 chk.warnDeprecated(pos, sym);
1335 return sym;
1336 }
1338 /** Resolve a constructor, throw a fatal error if not found.
1339 * @param pos The position to use for error reporting.
1340 * @param env The environment current at the method invocation.
1341 * @param site The type to be constructed.
1342 * @param argtypes The types of the invocation's value arguments.
1343 * @param typeargtypes The types of the invocation's type arguments.
1344 */
1345 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
1346 Type site,
1347 List<Type> argtypes,
1348 List<Type> typeargtypes) {
1349 Symbol sym = resolveConstructor(
1350 pos, env, site, argtypes, typeargtypes);
1351 if (sym.kind == MTH) return (MethodSymbol)sym;
1352 else throw new FatalError(
1353 diags.fragment("fatal.err.cant.locate.ctor", site));
1354 }
1356 /** Resolve operator.
1357 * @param pos The position to use for error reporting.
1358 * @param optag The tag of the operation tree.
1359 * @param env The environment current at the operation.
1360 * @param argtypes The types of the operands.
1361 */
1362 Symbol resolveOperator(DiagnosticPosition pos, int optag,
1363 Env<AttrContext> env, List<Type> argtypes) {
1364 Name name = treeinfo.operatorName(optag);
1365 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
1366 null, false, false, true);
1367 if (boxingEnabled && sym.kind >= WRONG_MTHS)
1368 sym = findMethod(env, syms.predefClass.type, name, argtypes,
1369 null, true, false, true);
1370 return access(sym, pos, env.enclClass.sym.type, name,
1371 false, argtypes, null);
1372 }
1374 /** Resolve operator.
1375 * @param pos The position to use for error reporting.
1376 * @param optag The tag of the operation tree.
1377 * @param env The environment current at the operation.
1378 * @param arg The type of the operand.
1379 */
1380 Symbol resolveUnaryOperator(DiagnosticPosition pos, int optag, Env<AttrContext> env, Type arg) {
1381 return resolveOperator(pos, optag, env, List.of(arg));
1382 }
1384 /** Resolve binary operator.
1385 * @param pos The position to use for error reporting.
1386 * @param optag The tag of the operation tree.
1387 * @param env The environment current at the operation.
1388 * @param left The types of the left operand.
1389 * @param right The types of the right operand.
1390 */
1391 Symbol resolveBinaryOperator(DiagnosticPosition pos,
1392 int optag,
1393 Env<AttrContext> env,
1394 Type left,
1395 Type right) {
1396 return resolveOperator(pos, optag, env, List.of(left, right));
1397 }
1399 /**
1400 * Resolve `c.name' where name == this or name == super.
1401 * @param pos The position to use for error reporting.
1402 * @param env The environment current at the expression.
1403 * @param c The qualifier.
1404 * @param name The identifier's name.
1405 */
1406 Symbol resolveSelf(DiagnosticPosition pos,
1407 Env<AttrContext> env,
1408 TypeSymbol c,
1409 Name name) {
1410 Env<AttrContext> env1 = env;
1411 boolean staticOnly = false;
1412 while (env1.outer != null) {
1413 if (isStatic(env1)) staticOnly = true;
1414 if (env1.enclClass.sym == c) {
1415 Symbol sym = env1.info.scope.lookup(name).sym;
1416 if (sym != null) {
1417 if (staticOnly) sym = new StaticError(sym);
1418 return access(sym, pos, env.enclClass.sym.type,
1419 name, true);
1420 }
1421 }
1422 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1423 env1 = env1.outer;
1424 }
1425 log.error(pos, "not.encl.class", c);
1426 return syms.errSymbol;
1427 }
1429 /**
1430 * Resolve `c.this' for an enclosing class c that contains the
1431 * named member.
1432 * @param pos The position to use for error reporting.
1433 * @param env The environment current at the expression.
1434 * @param member The member that must be contained in the result.
1435 */
1436 Symbol resolveSelfContaining(DiagnosticPosition pos,
1437 Env<AttrContext> env,
1438 Symbol member) {
1439 Name name = names._this;
1440 Env<AttrContext> env1 = env;
1441 boolean staticOnly = false;
1442 while (env1.outer != null) {
1443 if (isStatic(env1)) staticOnly = true;
1444 if (env1.enclClass.sym.isSubClass(member.owner, types) &&
1445 isAccessible(env, env1.enclClass.sym.type, member)) {
1446 Symbol sym = env1.info.scope.lookup(name).sym;
1447 if (sym != null) {
1448 if (staticOnly) sym = new StaticError(sym);
1449 return access(sym, pos, env.enclClass.sym.type,
1450 name, true);
1451 }
1452 }
1453 if ((env1.enclClass.sym.flags() & STATIC) != 0)
1454 staticOnly = true;
1455 env1 = env1.outer;
1456 }
1457 log.error(pos, "encl.class.required", member);
1458 return syms.errSymbol;
1459 }
1461 /**
1462 * Resolve an appropriate implicit this instance for t's container.
1463 * JLS2 8.8.5.1 and 15.9.2
1464 */
1465 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
1466 Type thisType = (((t.tsym.owner.kind & (MTH|VAR)) != 0)
1467 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
1468 : resolveSelfContaining(pos, env, t.tsym)).type;
1469 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym)
1470 log.error(pos, "cant.ref.before.ctor.called", "this");
1471 return thisType;
1472 }
1474 /* ***************************************************************************
1475 * ResolveError classes, indicating error situations when accessing symbols
1476 ****************************************************************************/
1478 public void logAccessError(Env<AttrContext> env, JCTree tree, Type type) {
1479 AccessError error = new AccessError(env, type.getEnclosingType(), type.tsym);
1480 error.report(log, tree.pos(), type.getEnclosingType(), null, null, null);
1481 }
1483 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
1485 public Object methodArguments(List<Type> argtypes) {
1486 return argtypes.isEmpty() ? noArgs : argtypes;
1487 }
1489 /** Root class for resolve errors.
1490 * Instances of this class indicate "Symbol not found".
1491 * Instances of subclass indicate other errors.
1492 */
1493 private class ResolveError extends Symbol {
1495 ResolveError(int kind, Symbol sym, String debugName) {
1496 super(kind, 0, null, null, null);
1497 this.debugName = debugName;
1498 this.sym = sym;
1499 }
1501 /** The name of the kind of error, for debugging only.
1502 */
1503 final String debugName;
1505 /** The symbol that was determined by resolution, or errSymbol if none
1506 * was found.
1507 */
1508 final Symbol sym;
1510 /** The symbol that was a close mismatch, or null if none was found.
1511 * wrongSym is currently set if a simgle method with the correct name, but
1512 * the wrong parameters was found.
1513 */
1514 Symbol wrongSym;
1516 /** An auxiliary explanation set in case of instantiation errors.
1517 */
1518 JCDiagnostic explanation;
1521 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
1522 throw new AssertionError();
1523 }
1525 /** Print the (debug only) name of the kind of error.
1526 */
1527 public String toString() {
1528 return debugName + " wrongSym=" + wrongSym + " explanation=" + explanation;
1529 }
1531 /** Update wrongSym and explanation and return this.
1532 */
1533 ResolveError setWrongSym(Symbol sym, JCDiagnostic explanation) {
1534 this.wrongSym = sym;
1535 this.explanation = explanation;
1536 return this;
1537 }
1539 /** Update wrongSym and return this.
1540 */
1541 ResolveError setWrongSym(Symbol sym) {
1542 this.wrongSym = sym;
1543 this.explanation = null;
1544 return this;
1545 }
1547 public boolean exists() {
1548 switch (kind) {
1549 case HIDDEN:
1550 case ABSENT_VAR:
1551 case ABSENT_MTH:
1552 case ABSENT_TYP:
1553 return false;
1554 default:
1555 return true;
1556 }
1557 }
1559 /** Report error.
1560 * @param log The error log to be used for error reporting.
1561 * @param pos The position to be used for error reporting.
1562 * @param site The original type from where the selection took place.
1563 * @param name The name of the symbol to be resolved.
1564 * @param argtypes The invocation's value arguments,
1565 * if we looked for a method.
1566 * @param typeargtypes The invocation's type arguments,
1567 * if we looked for a method.
1568 */
1569 void report(Log log, DiagnosticPosition pos, Type site, Name name,
1570 List<Type> argtypes, List<Type> typeargtypes) {
1571 if (argtypes == null)
1572 argtypes = List.nil();
1573 if (typeargtypes == null)
1574 typeargtypes = List.nil();
1575 if (name != names.error) {
1576 KindName kindname = absentKind(kind);
1577 Name idname = name;
1578 if (kind >= WRONG_MTHS && kind <= ABSENT_MTH) {
1579 if (isOperator(name)) {
1580 log.error(pos, "operator.cant.be.applied",
1581 name, argtypes);
1582 return;
1583 }
1584 if (name == names.init) {
1585 kindname = KindName.CONSTRUCTOR;
1586 idname = site.tsym.name;
1587 }
1588 }
1589 if (kind == WRONG_MTH) {
1590 Symbol ws = wrongSym.asMemberOf(site, types);
1591 log.error(pos,
1592 "cant.apply.symbol" + (explanation != null ? ".1" : ""),
1593 kindname,
1594 ws.name == names.init ? ws.owner.name : ws.name,
1595 methodArguments(ws.type.getParameterTypes()),
1596 methodArguments(argtypes),
1597 kindName(ws.owner),
1598 ws.owner.type,
1599 explanation);
1600 } else if (!site.tsym.name.isEmpty()) {
1601 if (site.tsym.kind == PCK && !site.tsym.exists())
1602 log.error(pos, "doesnt.exist", site.tsym);
1603 else {
1604 String errKey = getErrorKey("cant.resolve.location",
1605 argtypes, typeargtypes,
1606 kindname);
1607 log.error(pos, errKey, kindname, idname, //symbol kindname, name
1608 typeargtypes, argtypes, //type parameters and arguments (if any)
1609 typeKindName(site), site); //location kindname, type
1610 }
1611 } else {
1612 String errKey = getErrorKey("cant.resolve",
1613 argtypes, typeargtypes,
1614 kindname);
1615 log.error(pos, errKey, kindname, idname, //symbol kindname, name
1616 typeargtypes, argtypes); //type parameters and arguments (if any)
1617 }
1618 }
1619 }
1620 //where
1621 String getErrorKey(String key, List<Type> argtypes, List<Type> typeargtypes, KindName kindname) {
1622 String suffix = "";
1623 switch (kindname) {
1624 case METHOD:
1625 case CONSTRUCTOR: {
1626 suffix += ".args";
1627 suffix += typeargtypes.nonEmpty() ? ".params" : "";
1628 }
1629 }
1630 return key + suffix;
1631 }
1633 /** A name designates an operator if it consists
1634 * of a non-empty sequence of operator symbols +-~!/*%&|^<>=
1635 */
1636 boolean isOperator(Name name) {
1637 int i = 0;
1638 while (i < name.getByteLength() &&
1639 "+-~!*/%&|^<>=".indexOf(name.getByteAt(i)) >= 0) i++;
1640 return i > 0 && i == name.getByteLength();
1641 }
1642 }
1644 /** Resolve error class indicating that a symbol is not accessible.
1645 */
1646 class AccessError extends ResolveError {
1648 AccessError(Symbol sym) {
1649 this(null, null, sym);
1650 }
1652 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
1653 super(HIDDEN, sym, "access error");
1654 this.env = env;
1655 this.site = site;
1656 if (debugResolve)
1657 log.error("proc.messager", sym + " @ " + site + " is inaccessible.");
1658 }
1660 private Env<AttrContext> env;
1661 private Type site;
1663 /** Report error.
1664 * @param log The error log to be used for error reporting.
1665 * @param pos The position to be used for error reporting.
1666 * @param site The original type from where the selection took place.
1667 * @param name The name of the symbol to be resolved.
1668 * @param argtypes The invocation's value arguments,
1669 * if we looked for a method.
1670 * @param typeargtypes The invocation's type arguments,
1671 * if we looked for a method.
1672 */
1673 void report(Log log, DiagnosticPosition pos, Type site, Name name,
1674 List<Type> argtypes, List<Type> typeargtypes) {
1675 if (sym.owner.type.tag != ERROR) {
1676 if (sym.name == names.init && sym.owner != site.tsym)
1677 new ResolveError(ABSENT_MTH, sym.owner, "absent method " + sym).report(
1678 log, pos, site, name, argtypes, typeargtypes);
1679 if ((sym.flags() & PUBLIC) != 0
1680 || (env != null && this.site != null
1681 && !isAccessible(env, this.site)))
1682 log.error(pos, "not.def.access.class.intf.cant.access",
1683 sym, sym.location());
1684 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0)
1685 log.error(pos, "report.access", sym,
1686 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
1687 sym.location());
1688 else
1689 log.error(pos, "not.def.public.cant.access",
1690 sym, sym.location());
1691 }
1692 }
1693 }
1695 /** Resolve error class indicating that an instance member was accessed
1696 * from a static context.
1697 */
1698 class StaticError extends ResolveError {
1699 StaticError(Symbol sym) {
1700 super(STATICERR, sym, "static error");
1701 }
1703 /** Report error.
1704 * @param log The error log to be used for error reporting.
1705 * @param pos The position to be used for error reporting.
1706 * @param site The original type from where the selection took place.
1707 * @param name The name of the symbol to be resolved.
1708 * @param argtypes The invocation's value arguments,
1709 * if we looked for a method.
1710 * @param typeargtypes The invocation's type arguments,
1711 * if we looked for a method.
1712 */
1713 void report(Log log,
1714 DiagnosticPosition pos,
1715 Type site,
1716 Name name,
1717 List<Type> argtypes,
1718 List<Type> typeargtypes) {
1719 Symbol errSym = ((sym.kind == TYP && sym.type.tag == CLASS)
1720 ? types.erasure(sym.type).tsym
1721 : sym);
1722 log.error(pos, "non-static.cant.be.ref",
1723 kindName(sym), errSym);
1724 }
1725 }
1727 /** Resolve error class indicating an ambiguous reference.
1728 */
1729 class AmbiguityError extends ResolveError {
1730 Symbol sym1;
1731 Symbol sym2;
1733 AmbiguityError(Symbol sym1, Symbol sym2) {
1734 super(AMBIGUOUS, sym1, "ambiguity error");
1735 this.sym1 = sym1;
1736 this.sym2 = sym2;
1737 }
1739 /** Report error.
1740 * @param log The error log to be used for error reporting.
1741 * @param pos The position to be used for error reporting.
1742 * @param site The original type from where the selection took place.
1743 * @param name The name of the symbol to be resolved.
1744 * @param argtypes The invocation's value arguments,
1745 * if we looked for a method.
1746 * @param typeargtypes The invocation's type arguments,
1747 * if we looked for a method.
1748 */
1749 void report(Log log, DiagnosticPosition pos, Type site, Name name,
1750 List<Type> argtypes, List<Type> typeargtypes) {
1751 AmbiguityError pair = this;
1752 while (true) {
1753 if (pair.sym1.kind == AMBIGUOUS)
1754 pair = (AmbiguityError)pair.sym1;
1755 else if (pair.sym2.kind == AMBIGUOUS)
1756 pair = (AmbiguityError)pair.sym2;
1757 else break;
1758 }
1759 Name sname = pair.sym1.name;
1760 if (sname == names.init) sname = pair.sym1.owner.name;
1761 log.error(pos, "ref.ambiguous", sname,
1762 kindName(pair.sym1),
1763 pair.sym1,
1764 pair.sym1.location(site, types),
1765 kindName(pair.sym2),
1766 pair.sym2,
1767 pair.sym2.location(site, types));
1768 }
1769 }
1771 enum MethodResolutionPhase {
1772 BASIC(false, false),
1773 BOX(true, false),
1774 VARARITY(true, true);
1776 boolean isBoxingRequired;
1777 boolean isVarargsRequired;
1779 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
1780 this.isBoxingRequired = isBoxingRequired;
1781 this.isVarargsRequired = isVarargsRequired;
1782 }
1784 public boolean isBoxingRequired() {
1785 return isBoxingRequired;
1786 }
1788 public boolean isVarargsRequired() {
1789 return isVarargsRequired;
1790 }
1792 public boolean isApplicable(boolean boxingEnabled, boolean varargsEnabled) {
1793 return (varargsEnabled || !isVarargsRequired) &&
1794 (boxingEnabled || !isBoxingRequired);
1795 }
1796 }
1798 private Map<MethodResolutionPhase, Symbol> methodResolutionCache =
1799 new HashMap<MethodResolutionPhase, Symbol>(MethodResolutionPhase.values().length);
1801 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
1803 private MethodResolutionPhase firstErroneousResolutionPhase() {
1804 MethodResolutionPhase bestSoFar = BASIC;
1805 Symbol sym = methodNotFound;
1806 List<MethodResolutionPhase> steps = methodResolutionSteps;
1807 while (steps.nonEmpty() &&
1808 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1809 sym.kind >= WRONG_MTHS) {
1810 sym = methodResolutionCache.get(steps.head);
1811 bestSoFar = steps.head;
1812 steps = steps.tail;
1813 }
1814 return bestSoFar;
1815 }
1816 }
