1 /*
2 * Copyright (c) 2003, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.code;
27
28 import java.lang.ref.SoftReference;
29 import java.util.HashSet;
30 import java.util.HashMap;
31 import java.util.Locale;
32 import java.util.Map;
33 import java.util.Optional;
34 import java.util.Set;
35 import java.util.WeakHashMap;
36 import java.util.function.BiPredicate;
37 import java.util.function.Function;
38 import java.util.function.Predicate;
39 import java.util.stream.Collector;
40
41 import javax.tools.JavaFileObject;
42
43 import com.sun.tools.javac.code.Attribute.RetentionPolicy;
44 import com.sun.tools.javac.code.Lint.LintCategory;
45 import com.sun.tools.javac.code.Source.Feature;
46 import com.sun.tools.javac.code.Type.UndetVar.InferenceBound;
47 import com.sun.tools.javac.code.TypeMetadata.Annotations;
48 import com.sun.tools.javac.comp.AttrContext;
49 import com.sun.tools.javac.comp.Check;
50 import com.sun.tools.javac.comp.Enter;
51 import com.sun.tools.javac.comp.Env;
52 import com.sun.tools.javac.jvm.ClassFile;
53 import com.sun.tools.javac.util.*;
54
55 import static com.sun.tools.javac.code.BoundKind.*;
56 import static com.sun.tools.javac.code.Flags.*;
57 import static com.sun.tools.javac.code.Kinds.Kind.*;
58 import static com.sun.tools.javac.code.Scope.*;
59 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
60 import static com.sun.tools.javac.code.Symbol.*;
61 import static com.sun.tools.javac.code.Type.*;
62 import static com.sun.tools.javac.code.TypeTag.*;
63 import static com.sun.tools.javac.jvm.ClassFile.externalize;
64 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
65
66 /**
67 * Utility class containing various operations on types.
68 *
69 * <p>Unless other names are more illustrative, the following naming
70 * conventions should be observed in this file:
71 *
72 * <dl>
73 * <dt>t</dt>
74 * <dd>If the first argument to an operation is a type, it should be named t.</dd>
75 * <dt>s</dt>
76 * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd>
77 * <dt>ts</dt>
78 * <dd>If an operations takes a list of types, the first should be named ts.</dd>
79 * <dt>ss</dt>
80 * <dd>A second list of types should be named ss.</dd>
81 * </dl>
82 *
83 * <p><b>This is NOT part of any supported API.
84 * If you write code that depends on this, you do so at your own risk.
85 * This code and its internal interfaces are subject to change or
86 * deletion without notice.</b>
87 */
88 public class Types {
89 protected static final Context.Key<Types> typesKey = new Context.Key<>();
90
91 final Symtab syms;
92 final JavacMessages messages;
93 final Names names;
94 final boolean allowPrimitiveClasses;
95 final Check chk;
96 final Enter enter;
97 JCDiagnostic.Factory diags;
98 List<Warner> warnStack = List.nil();
99 final Name capturedName;
100
101 public final Warner noWarnings;
102
103 // <editor-fold defaultstate="collapsed" desc="Instantiating">
104 public static Types instance(Context context) {
105 Types instance = context.get(typesKey);
106 if (instance == null)
107 instance = new Types(context);
108 return instance;
109 }
110
111 @SuppressWarnings("this-escape")
112 protected Types(Context context) {
113 context.put(typesKey, this);
114 syms = Symtab.instance(context);
115 names = Names.instance(context);
116 Source source = Source.instance(context);
117 chk = Check.instance(context);
118 enter = Enter.instance(context);
119 capturedName = names.fromString("<captured wildcard>");
120 messages = JavacMessages.instance(context);
121 diags = JCDiagnostic.Factory.instance(context);
122 noWarnings = new Warner(null);
123 Options options = Options.instance(context);
124 allowPrimitiveClasses = Feature.PRIMITIVE_CLASSES.allowedInSource(source) && options.isSet("enablePrimitiveClasses");
125 }
126 // </editor-fold>
127
128 // <editor-fold defaultstate="collapsed" desc="bounds">
129 /**
130 * Get a wildcard's upper bound, returning non-wildcards unchanged.
131 * @param t a type argument, either a wildcard or a type
132 */
133 public Type wildUpperBound(Type t) {
134 if (t.hasTag(WILDCARD)) {
135 WildcardType w = (WildcardType) t;
136 if (w.isSuperBound())
137 return w.bound == null ? syms.objectType : w.bound.getUpperBound();
138 else
139 return wildUpperBound(w.type);
140 }
141 else return t;
142 }
143
144 /**
145 * Get a capture variable's upper bound, returning other types unchanged.
146 * @param t a type
147 */
148 public Type cvarUpperBound(Type t) {
149 if (t.hasTag(TYPEVAR)) {
150 TypeVar v = (TypeVar) t;
151 return v.isCaptured() ? cvarUpperBound(v.getUpperBound()) : v;
152 }
153 else return t;
154 }
155
156 /**
157 * Get a wildcard's lower bound, returning non-wildcards unchanged.
158 * @param t a type argument, either a wildcard or a type
159 */
160 public Type wildLowerBound(Type t) {
161 if (t.hasTag(WILDCARD)) {
162 WildcardType w = (WildcardType) t;
163 return w.isExtendsBound() ? syms.botType : wildLowerBound(w.type);
164 }
165 else return t;
166 }
167
168 /**
169 * Get a capture variable's lower bound, returning other types unchanged.
170 * @param t a type
171 */
172 public Type cvarLowerBound(Type t) {
173 if (t.hasTag(TYPEVAR) && ((TypeVar) t).isCaptured()) {
174 return cvarLowerBound(t.getLowerBound());
175 }
176 else return t;
177 }
178
179 /**
180 * Recursively skip type-variables until a class/array type is found; capture conversion is then
181 * (optionally) applied to the resulting type. This is useful for i.e. computing a site that is
182 * suitable for a method lookup.
183 */
184 public Type skipTypeVars(Type site, boolean capture) {
185 while (site.hasTag(TYPEVAR)) {
186 site = site.getUpperBound();
187 }
188 return capture ? capture(site) : site;
189 }
190 // </editor-fold>
191
192 // <editor-fold defaultstate="collapsed" desc="projections">
193
194 /**
195 * A projection kind. See {@link TypeProjection}
196 */
197 enum ProjectionKind {
198 UPWARDS() {
199 @Override
200 ProjectionKind complement() {
201 return DOWNWARDS;
202 }
203 },
204 DOWNWARDS() {
205 @Override
206 ProjectionKind complement() {
207 return UPWARDS;
208 }
209 };
210
211 abstract ProjectionKind complement();
212 }
213
214 /**
215 * This visitor performs upwards and downwards projections on types.
216 *
217 * A projection is defined as a function that takes a type T, a set of type variables V and that
218 * produces another type S.
219 *
220 * An upwards projection maps a type T into a type S such that (i) T has no variables in V,
221 * and (ii) S is an upper bound of T.
222 *
223 * A downwards projection maps a type T into a type S such that (i) T has no variables in V,
224 * and (ii) S is a lower bound of T.
225 *
226 * Note that projections are only allowed to touch variables in V. Therefore, it is possible for
227 * a projection to leave its input type unchanged if it does not contain any variables in V.
228 *
229 * Moreover, note that while an upwards projection is always defined (every type as an upper bound),
230 * a downwards projection is not always defined.
231 *
232 * Examples:
233 *
234 * {@code upwards(List<#CAP1>, [#CAP1]) = List<? extends String>, where #CAP1 <: String }
235 * {@code downwards(List<#CAP2>, [#CAP2]) = List<? super String>, where #CAP2 :> String }
236 * {@code upwards(List<#CAP1>, [#CAP2]) = List<#CAP1> }
237 * {@code downwards(List<#CAP1>, [#CAP1]) = not defined }
238 */
239 class TypeProjection extends TypeMapping<ProjectionKind> {
240
241 List<Type> vars;
242 Set<Type> seen = new HashSet<>();
243
244 public TypeProjection(List<Type> vars) {
245 this.vars = vars;
246 }
247
248 @Override
249 public Type visitClassType(ClassType t, ProjectionKind pkind) {
250 if (t.isCompound()) {
251 List<Type> components = directSupertypes(t);
252 List<Type> components1 = components.map(c -> c.map(this, pkind));
253 if (components == components1) return t;
254 else return makeIntersectionType(components1);
255 } else {
256 Type outer = t.getEnclosingType();
257 Type outer1 = visit(outer, pkind);
258 List<Type> typarams = t.getTypeArguments();
259 List<Type> formals = t.tsym.type.getTypeArguments();
260 ListBuffer<Type> typarams1 = new ListBuffer<>();
261 boolean changed = false;
262 for (Type actual : typarams) {
263 Type t2 = mapTypeArgument(t, formals.head.getUpperBound(), actual, pkind);
264 if (t2.hasTag(BOT)) {
265 //not defined
266 return syms.botType;
267 }
268 typarams1.add(t2);
269 changed |= actual != t2;
270 formals = formals.tail;
271 }
272 if (outer1 == outer && !changed) return t;
273 else return new ClassType(outer1, typarams1.toList(), t.tsym, t.getMetadata(), t.getFlavor()) {
274 @Override
275 protected boolean needsStripping() {
276 return true;
277 }
278 };
279 }
280 }
281
282 @Override
283 public Type visitArrayType(ArrayType t, ProjectionKind s) {
284 Type elemtype = t.elemtype;
285 Type elemtype1 = visit(elemtype, s);
286 if (elemtype1 == elemtype) {
287 return t;
288 } else if (elemtype1.hasTag(BOT)) {
289 //undefined
290 return syms.botType;
291 } else {
292 return new ArrayType(elemtype1, t.tsym, t.metadata) {
293 @Override
294 protected boolean needsStripping() {
295 return true;
296 }
297 };
298 }
299 }
300
301 @Override
302 public Type visitTypeVar(TypeVar t, ProjectionKind pkind) {
303 if (vars.contains(t)) {
304 if (seen.add(t)) {
305 try {
306 final Type bound;
307 switch (pkind) {
308 case UPWARDS:
309 bound = t.getUpperBound();
310 break;
311 case DOWNWARDS:
312 bound = (t.getLowerBound() == null) ?
313 syms.botType :
314 t.getLowerBound();
315 break;
316 default:
317 Assert.error();
318 return null;
319 }
320 return bound.map(this, pkind);
321 } finally {
322 seen.remove(t);
323 }
324 } else {
325 //cycle
326 return pkind == ProjectionKind.UPWARDS ?
327 syms.objectType : syms.botType;
328 }
329 } else {
330 return t;
331 }
332 }
333
334 private Type mapTypeArgument(Type site, Type declaredBound, Type t, ProjectionKind pkind) {
335 return t.containsAny(vars) ?
336 t.map(new TypeArgumentProjection(site, declaredBound), pkind) :
337 t;
338 }
339
340 class TypeArgumentProjection extends TypeMapping<ProjectionKind> {
341
342 Type site;
343 Type declaredBound;
344
345 TypeArgumentProjection(Type site, Type declaredBound) {
346 this.site = site;
347 this.declaredBound = declaredBound;
348 }
349
350 @Override
351 public Type visitType(Type t, ProjectionKind pkind) {
352 //type argument is some type containing restricted vars
353 if (pkind == ProjectionKind.DOWNWARDS) {
354 //not defined
355 return syms.botType;
356 }
357 Type upper = t.map(TypeProjection.this, ProjectionKind.UPWARDS);
358 Type lower = t.map(TypeProjection.this, ProjectionKind.DOWNWARDS);
359 List<Type> formals = site.tsym.type.getTypeArguments();
360 BoundKind bk;
361 Type bound;
362 if (!isSameType(upper, syms.objectType) &&
363 (declaredBound.containsAny(formals) ||
364 !isSubtype(declaredBound, upper))) {
365 bound = upper;
366 bk = EXTENDS;
367 } else if (!lower.hasTag(BOT)) {
368 bound = lower;
369 bk = SUPER;
370 } else {
371 bound = syms.objectType;
372 bk = UNBOUND;
373 }
374 return makeWildcard(bound, bk);
375 }
376
377 @Override
378 public Type visitWildcardType(WildcardType wt, ProjectionKind pkind) {
379 //type argument is some wildcard whose bound contains restricted vars
380 Type bound = syms.botType;
381 BoundKind bk = wt.kind;
382 switch (wt.kind) {
383 case EXTENDS:
384 bound = wt.type.map(TypeProjection.this, pkind);
385 if (bound.hasTag(BOT)) {
386 return syms.botType;
387 }
388 break;
389 case SUPER:
390 bound = wt.type.map(TypeProjection.this, pkind.complement());
391 if (bound.hasTag(BOT)) {
392 bound = syms.objectType;
393 bk = UNBOUND;
394 }
395 break;
396 }
397 return makeWildcard(bound, bk);
398 }
399
400 private Type makeWildcard(Type bound, BoundKind bk) {
401 return new WildcardType(bound, bk, syms.boundClass) {
402 @Override
403 protected boolean needsStripping() {
404 return true;
405 }
406 };
407 }
408 }
409 }
410
411 /**
412 * Computes an upward projection of given type, and vars. See {@link TypeProjection}.
413 *
414 * @param t the type to be projected
415 * @param vars the set of type variables to be mapped
416 * @return the type obtained as result of the projection
417 */
418 public Type upward(Type t, List<Type> vars) {
419 return t.map(new TypeProjection(vars), ProjectionKind.UPWARDS);
420 }
421
422 /**
423 * Computes the set of captured variables mentioned in a given type. See {@link CaptureScanner}.
424 * This routine is typically used to computed the input set of variables to be used during
425 * an upwards projection (see {@link Types#upward(Type, List)}).
426 *
427 * @param t the type where occurrences of captured variables have to be found
428 * @return the set of captured variables found in t
429 */
430 public List<Type> captures(Type t) {
431 CaptureScanner cs = new CaptureScanner();
432 Set<Type> captures = new HashSet<>();
433 cs.visit(t, captures);
434 return List.from(captures);
435 }
436
437 /**
438 * This visitor scans a type recursively looking for occurrences of captured type variables.
439 */
440 class CaptureScanner extends SimpleVisitor<Void, Set<Type>> {
441
442 @Override
443 public Void visitType(Type t, Set<Type> types) {
444 return null;
445 }
446
447 @Override
448 public Void visitClassType(ClassType t, Set<Type> seen) {
449 if (t.isCompound()) {
450 directSupertypes(t).forEach(s -> visit(s, seen));
451 } else {
452 t.allparams().forEach(ta -> visit(ta, seen));
453 }
454 return null;
455 }
456
457 @Override
458 public Void visitArrayType(ArrayType t, Set<Type> seen) {
459 return visit(t.elemtype, seen);
460 }
461
462 @Override
463 public Void visitWildcardType(WildcardType t, Set<Type> seen) {
464 visit(t.type, seen);
465 return null;
466 }
467
468 @Override
469 public Void visitTypeVar(TypeVar t, Set<Type> seen) {
470 if ((t.tsym.flags() & Flags.SYNTHETIC) != 0 && seen.add(t)) {
471 visit(t.getUpperBound(), seen);
472 }
473 return null;
474 }
475
476 @Override
477 public Void visitCapturedType(CapturedType t, Set<Type> seen) {
478 if (seen.add(t)) {
479 visit(t.getUpperBound(), seen);
480 visit(t.getLowerBound(), seen);
481 }
482 return null;
483 }
484 }
485
486 // </editor-fold>
487
488 // <editor-fold defaultstate="collapsed" desc="isUnbounded">
489 /**
490 * Checks that all the arguments to a class are unbounded
491 * wildcards or something else that doesn't make any restrictions
492 * on the arguments. If a class isUnbounded, a raw super- or
493 * subclass can be cast to it without a warning.
494 * @param t a type
495 * @return true iff the given type is unbounded or raw
496 */
497 public boolean isUnbounded(Type t) {
498 return isUnbounded.visit(t);
499 }
500 // where
501 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() {
502
503 public Boolean visitType(Type t, Void ignored) {
504 return true;
505 }
506
507 @Override
508 public Boolean visitClassType(ClassType t, Void ignored) {
509 List<Type> parms = t.tsym.type.allparams();
510 List<Type> args = t.allparams();
511 while (parms.nonEmpty()) {
512 WildcardType unb = new WildcardType(syms.objectType,
513 BoundKind.UNBOUND,
514 syms.boundClass,
515 (TypeVar)parms.head);
516 if (!containsType(args.head, unb))
517 return false;
518 parms = parms.tail;
519 args = args.tail;
520 }
521 return true;
522 }
523 };
524 // </editor-fold>
525
526 // <editor-fold defaultstate="collapsed" desc="asSub">
527 /**
528 * Return the least specific subtype of t that starts with symbol
529 * sym. If none exists, return null. The least specific subtype
530 * is determined as follows:
531 *
532 * <p>If there is exactly one parameterized instance of sym that is a
533 * subtype of t, that parameterized instance is returned.<br>
534 * Otherwise, if the plain type or raw type `sym' is a subtype of
535 * type t, the type `sym' itself is returned. Otherwise, null is
536 * returned.
537 */
538 public Type asSub(Type t, Symbol sym) {
539 return asSub.visit(t, sym);
540 }
541 // where
542 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() {
543
544 public Type visitType(Type t, Symbol sym) {
545 return null;
546 }
547
548 @Override
549 public Type visitClassType(ClassType t, Symbol sym) {
550 if (t.tsym == sym)
551 return t;
552 Type base = asSuper(sym.type, t.tsym);
553 if (base == null)
554 return null;
555 ListBuffer<Type> from = new ListBuffer<>();
556 ListBuffer<Type> to = new ListBuffer<>();
557 try {
558 adapt(base, t, from, to);
559 } catch (AdaptFailure ex) {
560 return null;
561 }
562 Type res = subst(sym.type, from.toList(), to.toList());
563 if (!isSubtype(res, t))
564 return null;
565 ListBuffer<Type> openVars = new ListBuffer<>();
566 for (List<Type> l = sym.type.allparams();
567 l.nonEmpty(); l = l.tail)
568 if (res.contains(l.head) && !t.contains(l.head))
569 openVars.append(l.head);
570 if (openVars.nonEmpty()) {
571 if (t.isRaw()) {
572 // The subtype of a raw type is raw
573 res = erasure(res);
574 } else {
575 // Unbound type arguments default to ?
576 List<Type> opens = openVars.toList();
577 ListBuffer<Type> qs = new ListBuffer<>();
578 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) {
579 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND,
580 syms.boundClass, (TypeVar) iter.head));
581 }
582 res = subst(res, opens, qs.toList());
583 }
584 }
585 return res;
586 }
587
588 @Override
589 public Type visitErrorType(ErrorType t, Symbol sym) {
590 return t;
591 }
592 };
593 // </editor-fold>
594
595 // <editor-fold defaultstate="collapsed" desc="isConvertible">
596 /**
597 * Is t a subtype of or convertible via boxing/unboxing
598 * conversion to s?
599 */
600 public boolean isConvertible(Type t, Type s, Warner warn) {
601 if (t.hasTag(ERROR)) {
602 return true;
603 }
604
605 if (allowPrimitiveClasses) {
606 boolean tValue = t.isPrimitiveClass();
607 boolean sValue = s.isPrimitiveClass();
608 if (tValue != sValue) {
609 return tValue ?
610 isSubtype(t.referenceProjection(), s) :
611 !t.hasTag(BOT) && isSubtype(t, s.referenceProjection());
612 }
613 }
614
615 boolean tPrimitive = t.isPrimitive();
616 boolean sPrimitive = s.isPrimitive();
617 if (tPrimitive == sPrimitive) {
618 return isSubtypeUnchecked(t, s, warn);
619 }
620 boolean tUndet = t.hasTag(UNDETVAR);
621 boolean sUndet = s.hasTag(UNDETVAR);
622
623 if (tUndet || sUndet) {
624 return tUndet ?
625 isSubtype(t, boxedTypeOrType(s)) :
626 isSubtype(boxedTypeOrType(t), s);
627 }
628
629 return tPrimitive
630 ? isSubtype(boxedClass(t).type, s)
631 : isSubtype(unboxedType(t), s);
632 }
633
634 /**
635 * Is t a subtype of or convertible via boxing/unboxing
636 * conversions to s?
637 */
638 public boolean isConvertible(Type t, Type s) {
639 return isConvertible(t, s, noWarnings);
640 }
641 // </editor-fold>
642
643 // <editor-fold defaultstate="collapsed" desc="findSam">
644
645 /**
646 * Exception used to report a function descriptor lookup failure. The exception
647 * wraps a diagnostic that can be used to generate more details error
648 * messages.
649 */
650 public static class FunctionDescriptorLookupError extends RuntimeException {
651 private static final long serialVersionUID = 0;
652
653 transient JCDiagnostic diagnostic;
654
655 FunctionDescriptorLookupError() {
656 this.diagnostic = null;
657 }
658
659 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) {
660 this.diagnostic = diag;
661 return this;
662 }
663
664 public JCDiagnostic getDiagnostic() {
665 return diagnostic;
666 }
667
668 @Override
669 public Throwable fillInStackTrace() {
670 // This is an internal exception; the stack trace is irrelevant.
671 return this;
672 }
673 }
674
675 /**
676 * A cache that keeps track of function descriptors associated with given
677 * functional interfaces.
678 */
679 class DescriptorCache {
680
681 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<>();
682
683 class FunctionDescriptor {
684 Symbol descSym;
685
686 FunctionDescriptor(Symbol descSym) {
687 this.descSym = descSym;
688 }
689
690 public Symbol getSymbol() {
691 return descSym;
692 }
693
694 public Type getType(Type site) {
695 site = removeWildcards(site);
696 if (site.isIntersection()) {
697 IntersectionClassType ict = (IntersectionClassType)site;
698 for (Type component : ict.getExplicitComponents()) {
699 if (!chk.checkValidGenericType(component)) {
700 //if the inferred functional interface type is not well-formed,
701 //or if it's not a subtype of the original target, issue an error
702 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site)));
703 }
704 }
705 } else {
706 if (!chk.checkValidGenericType(site)) {
707 //if the inferred functional interface type is not well-formed,
708 //or if it's not a subtype of the original target, issue an error
709 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site)));
710 }
711 }
712 return memberType(site, descSym);
713 }
714 }
715
716 class Entry {
717 final FunctionDescriptor cachedDescRes;
718 final int prevMark;
719
720 public Entry(FunctionDescriptor cachedDescRes,
721 int prevMark) {
722 this.cachedDescRes = cachedDescRes;
723 this.prevMark = prevMark;
724 }
725
726 boolean matches(int mark) {
727 return this.prevMark == mark;
728 }
729 }
730
731 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError {
732 Entry e = _map.get(origin);
733 CompoundScope members = membersClosure(origin.type, false);
734 if (e == null ||
735 !e.matches(members.getMark())) {
736 FunctionDescriptor descRes = findDescriptorInternal(origin, members);
737 _map.put(origin, new Entry(descRes, members.getMark()));
738 return descRes;
739 }
740 else {
741 return e.cachedDescRes;
742 }
743 }
744
745 /**
746 * Compute the function descriptor associated with a given functional interface
747 */
748 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin,
749 CompoundScope membersCache) throws FunctionDescriptorLookupError {
750 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0 || origin.isSealed()) {
751 //t must be an interface
752 throw failure("not.a.functional.intf", origin);
753 }
754
755 final ListBuffer<Symbol> abstracts = new ListBuffer<>();
756 for (Symbol sym : membersCache.getSymbols(new DescriptorFilter(origin))) {
757 Type mtype = memberType(origin.type, sym);
758 if (abstracts.isEmpty()) {
759 abstracts.append(sym);
760 } else if ((sym.name == abstracts.first().name &&
761 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) {
762 if (!abstracts.stream().filter(msym -> msym.owner.isSubClass(sym.enclClass(), Types.this))
763 .map(msym -> memberType(origin.type, msym))
764 .anyMatch(abstractMType -> isSubSignature(abstractMType, mtype))) {
765 abstracts.append(sym);
766 }
767 } else {
768 //the target method(s) should be the only abstract members of t
769 throw failure("not.a.functional.intf.1", origin,
770 diags.fragment(Fragments.IncompatibleAbstracts(Kinds.kindName(origin), origin)));
771 }
772 }
773 if (abstracts.isEmpty()) {
774 //t must define a suitable non-generic method
775 throw failure("not.a.functional.intf.1", origin,
776 diags.fragment(Fragments.NoAbstracts(Kinds.kindName(origin), origin)));
777 }
778 FunctionDescriptor descRes;
779 if (abstracts.size() == 1) {
780 descRes = new FunctionDescriptor(abstracts.first());
781 } else { // size > 1
782 descRes = mergeDescriptors(origin, abstracts.toList());
783 if (descRes == null) {
784 //we can get here if the functional interface is ill-formed
785 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>();
786 for (Symbol desc : abstracts) {
787 String key = desc.type.getThrownTypes().nonEmpty() ?
788 "descriptor.throws" : "descriptor";
789 descriptors.append(diags.fragment(key, desc.name,
790 desc.type.getParameterTypes(),
791 desc.type.getReturnType(),
792 desc.type.getThrownTypes()));
793 }
794 JCDiagnostic msg =
795 diags.fragment(Fragments.IncompatibleDescsInFunctionalIntf(Kinds.kindName(origin),
796 origin));
797 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors =
798 new JCDiagnostic.MultilineDiagnostic(msg, descriptors.toList());
799 throw failure(incompatibleDescriptors);
800 }
801 }
802 // an interface must be neither an identity interface nor a value interface to be functional.
803 List<Type> allInterfaces = closure(origin.type);
804 for (Type iface : allInterfaces) {
805 if (iface.isValueInterface()) {
806 throw failure("not.a.functional.intf.1", origin, diags.fragment(Fragments.ValueInterfaceNonfunctional));
807 }
808 if (iface.isIdentityInterface()) {
809 throw failure("not.a.functional.intf.1", origin, diags.fragment(Fragments.IdentityInterfaceNonfunctional));
810 }
811 }
812 return descRes;
813 }
814
815 /**
816 * Compute a synthetic type for the target descriptor given a list
817 * of override-equivalent methods in the functional interface type.
818 * The resulting method type is a method type that is override-equivalent
819 * and return-type substitutable with each method in the original list.
820 */
821 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) {
822 return mergeAbstracts(methodSyms, origin.type, false)
823 .map(bestSoFar -> new FunctionDescriptor(bestSoFar.baseSymbol()) {
824 @Override
825 public Type getType(Type origin) {
826 Type mt = memberType(origin, getSymbol());
827 return createMethodTypeWithThrown(mt, bestSoFar.type.getThrownTypes());
828 }
829 }).orElse(null);
830 }
831
832 FunctionDescriptorLookupError failure(String msg, Object... args) {
833 return failure(diags.fragment(msg, args));
834 }
835
836 FunctionDescriptorLookupError failure(JCDiagnostic diag) {
837 return new FunctionDescriptorLookupError().setMessage(diag);
838 }
839 }
840
841 private DescriptorCache descCache = new DescriptorCache();
842
843 /**
844 * Find the method descriptor associated to this class symbol - if the
845 * symbol 'origin' is not a functional interface, an exception is thrown.
846 */
847 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError {
848 return descCache.get(origin).getSymbol();
849 }
850
851 /**
852 * Find the type of the method descriptor associated to this class symbol -
853 * if the symbol 'origin' is not a functional interface, an exception is thrown.
854 */
855 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError {
856 return descCache.get(origin.tsym).getType(origin);
857 }
858
859 /**
860 * Is given type a functional interface?
861 */
862 public boolean isFunctionalInterface(TypeSymbol tsym) {
863 try {
864 findDescriptorSymbol(tsym);
865 return true;
866 } catch (FunctionDescriptorLookupError ex) {
867 return false;
868 }
869 }
870
871 public boolean isFunctionalInterface(Type site) {
872 try {
873 findDescriptorType(site);
874 return true;
875 } catch (FunctionDescriptorLookupError ex) {
876 return false;
877 }
878 }
879
880 public Type removeWildcards(Type site) {
881 if (site.getTypeArguments().stream().anyMatch(t -> t.hasTag(WILDCARD))) {
882 //compute non-wildcard parameterization - JLS 9.9
883 List<Type> actuals = site.getTypeArguments();
884 List<Type> formals = site.tsym.type.getTypeArguments();
885 ListBuffer<Type> targs = new ListBuffer<>();
886 for (Type formal : formals) {
887 Type actual = actuals.head;
888 Type bound = formal.getUpperBound();
889 if (actuals.head.hasTag(WILDCARD)) {
890 WildcardType wt = (WildcardType)actual;
891 //check that bound does not contain other formals
892 if (bound.containsAny(formals)) {
893 targs.add(wt.type);
894 } else {
895 //compute new type-argument based on declared bound and wildcard bound
896 switch (wt.kind) {
897 case UNBOUND:
898 targs.add(bound);
899 break;
900 case EXTENDS:
901 targs.add(glb(bound, wt.type));
902 break;
903 case SUPER:
904 targs.add(wt.type);
905 break;
906 default:
907 Assert.error("Cannot get here!");
908 }
909 }
910 } else {
911 //not a wildcard - the new type argument remains unchanged
912 targs.add(actual);
913 }
914 actuals = actuals.tail;
915 }
916 return subst(site.tsym.type, formals, targs.toList());
917 } else {
918 return site;
919 }
920 }
921
922 /**
923 * Create a symbol for a class that implements a given functional interface
924 * and overrides its functional descriptor. This routine is used for two
925 * main purposes: (i) checking well-formedness of a functional interface;
926 * (ii) perform functional interface bridge calculation.
927 */
928 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, Type target, long cflags) {
929 if (target == null || target == syms.unknownType) {
930 return null;
931 }
932 Symbol descSym = findDescriptorSymbol(target.tsym);
933 Type descType = findDescriptorType(target);
934 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass());
935 csym.completer = Completer.NULL_COMPLETER;
936 csym.members_field = WriteableScope.create(csym);
937 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym);
938 csym.members_field.enter(instDescSym);
939 Type.ClassType ctype = new Type.ClassType(Type.noType, List.nil(), csym);
940 ctype.supertype_field = syms.objectType;
941 ctype.interfaces_field = target.isIntersection() ?
942 directSupertypes(target) :
943 List.of(target);
944 csym.type = ctype;
945 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile;
946 return csym;
947 }
948
949 /**
950 * Find the minimal set of methods that are overridden by the functional
951 * descriptor in 'origin'. All returned methods are assumed to have different
952 * erased signatures.
953 */
954 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) {
955 Assert.check(isFunctionalInterface(origin));
956 Symbol descSym = findDescriptorSymbol(origin);
957 CompoundScope members = membersClosure(origin.type, false);
958 ListBuffer<Symbol> overridden = new ListBuffer<>();
959 outer: for (Symbol m2 : members.getSymbolsByName(descSym.name, bridgeFilter)) {
960 if (m2 == descSym) continue;
961 else if (descSym.overrides(m2, origin, Types.this, false)) {
962 for (Symbol m3 : overridden) {
963 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) ||
964 (m3.overrides(m2, origin, Types.this, false) &&
965 (pendingBridges((ClassSymbol)origin, m3.enclClass()) ||
966 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) {
967 continue outer;
968 }
969 }
970 overridden.add(m2);
971 }
972 }
973 return overridden.toList();
974 }
975 //where
976 // Use anonymous class instead of lambda expression intentionally,
977 // because the variable `names` has modifier: final.
978 private Predicate<Symbol> bridgeFilter = new Predicate<Symbol>() {
979 public boolean test(Symbol t) {
980 return t.kind == MTH &&
981 !names.isInitOrVNew(t.name) &&
982 t.name != names.clinit &&
983 (t.flags() & SYNTHETIC) == 0;
984 }
985 };
986
987 private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) {
988 //a symbol will be completed from a classfile if (a) symbol has
989 //an associated file object with CLASS kind and (b) the symbol has
990 //not been entered
991 if (origin.classfile != null &&
992 origin.classfile.getKind() == JavaFileObject.Kind.CLASS &&
993 enter.getEnv(origin) == null) {
994 return false;
995 }
996 if (origin == s) {
997 return true;
998 }
999 for (Type t : interfaces(origin.type)) {
1000 if (pendingBridges((ClassSymbol)t.tsym, s)) {
1001 return true;
1002 }
1003 }
1004 return false;
1005 }
1006 // </editor-fold>
1007
1008 /**
1009 * Scope filter used to skip methods that should be ignored (such as methods
1010 * overridden by j.l.Object) during function interface conversion interface check
1011 */
1012 class DescriptorFilter implements Predicate<Symbol> {
1013
1014 TypeSymbol origin;
1015
1016 DescriptorFilter(TypeSymbol origin) {
1017 this.origin = origin;
1018 }
1019
1020 @Override
1021 public boolean test(Symbol sym) {
1022 return sym.kind == MTH &&
1023 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT &&
1024 !overridesObjectMethod(origin, sym) &&
1025 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0;
1026 }
1027 }
1028
1029 // <editor-fold defaultstate="collapsed" desc="isSubtype">
1030 /**
1031 * Is t an unchecked subtype of s?
1032 */
1033 public boolean isSubtypeUnchecked(Type t, Type s) {
1034 return isSubtypeUnchecked(t, s, noWarnings);
1035 }
1036 /**
1037 * Is t an unchecked subtype of s?
1038 */
1039 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) {
1040 boolean result = isSubtypeUncheckedInternal(t, s, true, warn);
1041 if (result) {
1042 checkUnsafeVarargsConversion(t, s, warn);
1043 }
1044 return result;
1045 }
1046 //where
1047 private boolean isSubtypeUncheckedInternal(Type t, Type s, boolean capture, Warner warn) {
1048 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) {
1049 if (((ArrayType)t).elemtype.isPrimitive()) {
1050 return isSameType(elemtype(t), elemtype(s));
1051 } else {
1052 // if T.ref <: S, then T[] <: S[]
1053 Type es = elemtype(s);
1054 Type et = elemtype(t);
1055 if (allowPrimitiveClasses) {
1056 if (et.isPrimitiveClass()) {
1057 et = et.referenceProjection();
1058 if (es.isPrimitiveClass())
1059 es = es.referenceProjection(); // V <: V, surely
1060 }
1061 }
1062 if (!isSubtypeUncheckedInternal(et, es, false, warn))
1063 return false;
1064 return true;
1065 }
1066 } else if (isSubtype(t, s, capture)) {
1067 return true;
1068 } else if (t.hasTag(TYPEVAR)) {
1069 return isSubtypeUncheckedInternal(t.getUpperBound(), s, false, warn);
1070 } else if (!s.isRaw()) {
1071 Type t2 = asSuper(t, s.tsym);
1072 if (t2 != null && t2.isRaw()) {
1073 if (isReifiable(s)) {
1074 warn.silentWarn(LintCategory.UNCHECKED);
1075 } else {
1076 warn.warn(LintCategory.UNCHECKED);
1077 }
1078 return true;
1079 }
1080 }
1081 return false;
1082 }
1083
1084 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) {
1085 if (!t.hasTag(ARRAY) || isReifiable(t)) {
1086 return;
1087 }
1088 ArrayType from = (ArrayType)t;
1089 boolean shouldWarn = false;
1090 switch (s.getTag()) {
1091 case ARRAY:
1092 ArrayType to = (ArrayType)s;
1093 shouldWarn = from.isVarargs() &&
1094 !to.isVarargs() &&
1095 !isReifiable(from);
1096 break;
1097 case CLASS:
1098 shouldWarn = from.isVarargs();
1099 break;
1100 }
1101 if (shouldWarn) {
1102 warn.warn(LintCategory.VARARGS);
1103 }
1104 }
1105
1106 /**
1107 * Is t a subtype of s?<br>
1108 * (not defined for Method and ForAll types)
1109 */
1110 public final boolean isSubtype(Type t, Type s) {
1111 return isSubtype(t, s, true);
1112 }
1113 public final boolean isSubtypeNoCapture(Type t, Type s) {
1114 return isSubtype(t, s, false);
1115 }
1116 public boolean isSubtype(Type t, Type s, boolean capture) {
1117 if (t.equalsIgnoreMetadata(s))
1118 return true;
1119 if (s.isPartial())
1120 return isSuperType(s, t);
1121
1122 if (s.isCompound()) {
1123 for (Type s2 : interfaces(s).prepend(supertype(s))) {
1124 if (!isSubtype(t, s2, capture))
1125 return false;
1126 }
1127 return true;
1128 }
1129
1130 // Generally, if 's' is a lower-bounded type variable, recur on lower bound; but
1131 // for inference variables and intersections, we need to keep 's'
1132 // (see JLS 4.10.2 for intersections and 18.2.3 for inference vars)
1133 if (!t.hasTag(UNDETVAR) && !t.isCompound()) {
1134 // TODO: JDK-8039198, bounds checking sometimes passes in a wildcard as s
1135 Type lower = cvarLowerBound(wildLowerBound(s));
1136 if (s != lower && !lower.hasTag(BOT))
1137 return isSubtype(capture ? capture(t) : t, lower, false);
1138 }
1139
1140 return isSubtype.visit(capture ? capture(t) : t, s);
1141 }
1142 // where
1143 private TypeRelation isSubtype = new TypeRelation()
1144 {
1145 @Override
1146 public Boolean visitType(Type t, Type s) {
1147 switch (t.getTag()) {
1148 case BYTE:
1149 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag()));
1150 case CHAR:
1151 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag()));
1152 case SHORT: case INT: case LONG:
1153 case FLOAT: case DOUBLE:
1154 return t.getTag().isSubRangeOf(s.getTag());
1155 case BOOLEAN: case VOID:
1156 return t.hasTag(s.getTag());
1157 case TYPEVAR:
1158 return isSubtypeNoCapture(t.getUpperBound(), s);
1159 case BOT:
1160 return
1161 s.hasTag(BOT) || (s.hasTag(CLASS) && (!allowPrimitiveClasses || !s.isPrimitiveClass())) ||
1162 s.hasTag(ARRAY) || s.hasTag(TYPEVAR);
1163 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495)
1164 case NONE:
1165 return false;
1166 default:
1167 throw new AssertionError("isSubtype " + t.getTag());
1168 }
1169 }
1170
1171 private Set<TypePair> cache = new HashSet<>();
1172
1173 private boolean containsTypeRecursive(Type t, Type s) {
1174 TypePair pair = new TypePair(t, s);
1175 if (cache.add(pair)) {
1176 try {
1177 return containsType(t.getTypeArguments(),
1178 s.getTypeArguments());
1179 } finally {
1180 cache.remove(pair);
1181 }
1182 } else {
1183 return containsType(t.getTypeArguments(),
1184 rewriteSupers(s).getTypeArguments());
1185 }
1186 }
1187
1188 private Type rewriteSupers(Type t) {
1189 if (!t.isParameterized())
1190 return t;
1191 ListBuffer<Type> from = new ListBuffer<>();
1192 ListBuffer<Type> to = new ListBuffer<>();
1193 adaptSelf(t, from, to);
1194 if (from.isEmpty())
1195 return t;
1196 ListBuffer<Type> rewrite = new ListBuffer<>();
1197 boolean changed = false;
1198 for (Type orig : to.toList()) {
1199 Type s = rewriteSupers(orig);
1200 if (s.isSuperBound() && !s.isExtendsBound()) {
1201 s = new WildcardType(syms.objectType,
1202 BoundKind.UNBOUND,
1203 syms.boundClass,
1204 s.getMetadata());
1205 changed = true;
1206 } else if (s != orig) {
1207 s = new WildcardType(wildUpperBound(s),
1208 BoundKind.EXTENDS,
1209 syms.boundClass,
1210 s.getMetadata());
1211 changed = true;
1212 }
1213 rewrite.append(s);
1214 }
1215 if (changed)
1216 return subst(t.tsym.type, from.toList(), rewrite.toList());
1217 else
1218 return t;
1219 }
1220
1221 @Override
1222 public Boolean visitClassType(ClassType t, Type s) {
1223 Type sup = asSuper(t, s.tsym);
1224 if (sup == null) return false;
1225 // If t is an intersection, sup might not be a class type
1226 if (!sup.hasTag(CLASS)) return isSubtypeNoCapture(sup, s);
1227 return sup.tsym == s.tsym
1228 && (t.tsym != s.tsym || t.isReferenceProjection() == s.isReferenceProjection())
1229 // Check type variable containment
1230 && (!s.isParameterized() || containsTypeRecursive(s, sup))
1231 && isSubtypeNoCapture(sup.getEnclosingType(),
1232 s.getEnclosingType());
1233 }
1234
1235 @Override
1236 public Boolean visitArrayType(ArrayType t, Type s) {
1237 if (s.hasTag(ARRAY)) {
1238 if (t.elemtype.isPrimitive())
1239 return isSameType(t.elemtype, elemtype(s));
1240 else {
1241 // if T.ref <: S, then T[] <: S[]
1242 Type es = elemtype(s);
1243 Type et = elemtype(t);
1244 if (allowPrimitiveClasses && et.isPrimitiveClass()) {
1245 et = et.referenceProjection();
1246 if (es.isPrimitiveClass())
1247 es = es.referenceProjection(); // V <: V, surely
1248 }
1249 return isSubtypeNoCapture(et, es);
1250 }
1251 }
1252
1253 if (s.hasTag(CLASS)) {
1254 Name sname = s.tsym.getQualifiedName();
1255 return sname == names.java_lang_Object
1256 || sname == names.java_lang_Cloneable
1257 || sname == names.java_io_Serializable;
1258 }
1259
1260 return false;
1261 }
1262
1263 @Override
1264 public Boolean visitUndetVar(UndetVar t, Type s) {
1265 //todo: test against origin needed? or replace with substitution?
1266 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1267 return true;
1268 } else if (s.hasTag(BOT)) {
1269 //if 's' is 'null' there's no instantiated type U for which
1270 //U <: s (but 'null' itself, which is not a valid type)
1271 return false;
1272 }
1273
1274 t.addBound(InferenceBound.UPPER, s, Types.this);
1275 return true;
1276 }
1277
1278 @Override
1279 public Boolean visitErrorType(ErrorType t, Type s) {
1280 return true;
1281 }
1282 };
1283
1284 /**
1285 * Is t a subtype of every type in given list `ts'?<br>
1286 * (not defined for Method and ForAll types)<br>
1287 * Allows unchecked conversions.
1288 */
1289 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) {
1290 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1291 if (!isSubtypeUnchecked(t, l.head, warn))
1292 return false;
1293 return true;
1294 }
1295
1296 /**
1297 * Are corresponding elements of ts subtypes of ss? If lists are
1298 * of different length, return false.
1299 */
1300 public boolean isSubtypes(List<Type> ts, List<Type> ss) {
1301 while (ts.tail != null && ss.tail != null
1302 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1303 isSubtype(ts.head, ss.head)) {
1304 ts = ts.tail;
1305 ss = ss.tail;
1306 }
1307 return ts.tail == null && ss.tail == null;
1308 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1309 }
1310
1311 /**
1312 * Are corresponding elements of ts subtypes of ss, allowing
1313 * unchecked conversions? If lists are of different length,
1314 * return false.
1315 **/
1316 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) {
1317 while (ts.tail != null && ss.tail != null
1318 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1319 isSubtypeUnchecked(ts.head, ss.head, warn)) {
1320 ts = ts.tail;
1321 ss = ss.tail;
1322 }
1323 return ts.tail == null && ss.tail == null;
1324 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1325 }
1326 // </editor-fold>
1327
1328 // <editor-fold defaultstate="collapsed" desc="isSuperType">
1329 /**
1330 * Is t a supertype of s?
1331 */
1332 public boolean isSuperType(Type t, Type s) {
1333 switch (t.getTag()) {
1334 case ERROR:
1335 return true;
1336 case UNDETVAR: {
1337 UndetVar undet = (UndetVar)t;
1338 if (t == s ||
1339 undet.qtype == s ||
1340 s.hasTag(ERROR) ||
1341 s.hasTag(BOT)) {
1342 return true;
1343 }
1344 undet.addBound(InferenceBound.LOWER, s, this);
1345 return true;
1346 }
1347 default:
1348 return isSubtype(s, t);
1349 }
1350 }
1351 // </editor-fold>
1352
1353 // <editor-fold defaultstate="collapsed" desc="isSameType">
1354 /**
1355 * Are corresponding elements of the lists the same type? If
1356 * lists are of different length, return false.
1357 */
1358 public boolean isSameTypes(List<Type> ts, List<Type> ss) {
1359 while (ts.tail != null && ss.tail != null
1360 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1361 isSameType(ts.head, ss.head)) {
1362 ts = ts.tail;
1363 ss = ss.tail;
1364 }
1365 return ts.tail == null && ss.tail == null;
1366 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1367 }
1368
1369 /**
1370 * A polymorphic signature method (JLS 15.12.3) is a method that
1371 * (i) is declared in the java.lang.invoke.MethodHandle/VarHandle classes;
1372 * (ii) takes a single variable arity parameter;
1373 * (iii) whose declared type is Object[];
1374 * (iv) has any return type, Object signifying a polymorphic return type; and
1375 * (v) is native.
1376 */
1377 public boolean isSignaturePolymorphic(MethodSymbol msym) {
1378 List<Type> argtypes = msym.type.getParameterTypes();
1379 return (msym.flags_field & NATIVE) != 0 &&
1380 (msym.owner == syms.methodHandleType.tsym || msym.owner == syms.varHandleType.tsym) &&
1381 argtypes.length() == 1 &&
1382 argtypes.head.hasTag(TypeTag.ARRAY) &&
1383 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym;
1384 }
1385
1386 /**
1387 * Is t the same type as s?
1388 */
1389 public boolean isSameType(Type t, Type s) {
1390 return isSameTypeVisitor.visit(t, s);
1391 }
1392 // where
1393
1394 /**
1395 * Type-equality relation - type variables are considered
1396 * equals if they share the same object identity.
1397 */
1398 TypeRelation isSameTypeVisitor = new TypeRelation() {
1399
1400 public Boolean visitType(Type t, Type s) {
1401 if (t.equalsIgnoreMetadata(s))
1402 return true;
1403
1404 if (s.isPartial())
1405 return visit(s, t);
1406
1407 switch (t.getTag()) {
1408 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1409 case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE:
1410 return t.hasTag(s.getTag());
1411 case TYPEVAR: {
1412 if (s.hasTag(TYPEVAR)) {
1413 //type-substitution does not preserve type-var types
1414 //check that type var symbols and bounds are indeed the same
1415 return t == s;
1416 }
1417 else {
1418 //special case for s == ? super X, where upper(s) = u
1419 //check that u == t, where u has been set by Type.withTypeVar
1420 return s.isSuperBound() &&
1421 !s.isExtendsBound() &&
1422 visit(t, wildUpperBound(s));
1423 }
1424 }
1425 default:
1426 throw new AssertionError("isSameType " + t.getTag());
1427 }
1428 }
1429
1430 @Override
1431 public Boolean visitWildcardType(WildcardType t, Type s) {
1432 if (!s.hasTag(WILDCARD)) {
1433 return false;
1434 } else {
1435 WildcardType t2 = (WildcardType)s;
1436 return (t.kind == t2.kind || (t.isExtendsBound() && s.isExtendsBound())) &&
1437 isSameType(t.type, t2.type);
1438 }
1439 }
1440
1441 @Override
1442 public Boolean visitClassType(ClassType t, Type s) {
1443 if (t == s)
1444 return true;
1445
1446 if (s.isPartial())
1447 return visit(s, t);
1448
1449 if (s.isSuperBound() && !s.isExtendsBound())
1450 return visit(t, wildUpperBound(s)) && visit(t, wildLowerBound(s));
1451
1452 if (t.isCompound() && s.isCompound()) {
1453 if (!visit(supertype(t), supertype(s)))
1454 return false;
1455
1456 Map<Symbol,Type> tMap = new HashMap<>();
1457 for (Type ti : interfaces(t)) {
1458 tMap.put(ti.tsym, ti);
1459 }
1460 for (Type si : interfaces(s)) {
1461 if (!tMap.containsKey(si.tsym))
1462 return false;
1463 Type ti = tMap.remove(si.tsym);
1464 if (!visit(ti, si))
1465 return false;
1466 }
1467 return tMap.isEmpty();
1468 }
1469 return t.tsym == s.tsym
1470 && t.isReferenceProjection() == s.isReferenceProjection()
1471 && visit(getEnclosingType(t), getEnclosingType(s))
1472 && containsTypeEquivalent(t.getTypeArguments(), s.getTypeArguments());
1473 }
1474 // where
1475 private Type getEnclosingType(Type t) {
1476 Type et = t.getEnclosingType();
1477 if (et.isReferenceProjection()) {
1478 et = et.valueProjection();
1479 }
1480 return et;
1481 }
1482
1483 @Override
1484 public Boolean visitArrayType(ArrayType t, Type s) {
1485 if (t == s)
1486 return true;
1487
1488 if (s.isPartial())
1489 return visit(s, t);
1490
1491 return s.hasTag(ARRAY)
1492 && containsTypeEquivalent(t.elemtype, elemtype(s));
1493 }
1494
1495 @Override
1496 public Boolean visitMethodType(MethodType t, Type s) {
1497 // isSameType for methods does not take thrown
1498 // exceptions into account!
1499 return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType());
1500 }
1501
1502 @Override
1503 public Boolean visitPackageType(PackageType t, Type s) {
1504 return t == s;
1505 }
1506
1507 @Override
1508 public Boolean visitForAll(ForAll t, Type s) {
1509 if (!s.hasTag(FORALL)) {
1510 return false;
1511 }
1512
1513 ForAll forAll = (ForAll)s;
1514 return hasSameBounds(t, forAll)
1515 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
1516 }
1517
1518 @Override
1519 public Boolean visitUndetVar(UndetVar t, Type s) {
1520 if (s.hasTag(WILDCARD)) {
1521 // FIXME, this might be leftovers from before capture conversion
1522 return false;
1523 }
1524
1525 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1526 return true;
1527 }
1528
1529 t.addBound(InferenceBound.EQ, s, Types.this);
1530
1531 return true;
1532 }
1533
1534 @Override
1535 public Boolean visitErrorType(ErrorType t, Type s) {
1536 return true;
1537 }
1538 };
1539
1540 // </editor-fold>
1541
1542 // <editor-fold defaultstate="collapsed" desc="Contains Type">
1543 public boolean containedBy(Type t, Type s) {
1544 switch (t.getTag()) {
1545 case UNDETVAR:
1546 if (s.hasTag(WILDCARD)) {
1547 UndetVar undetvar = (UndetVar)t;
1548 WildcardType wt = (WildcardType)s;
1549 switch(wt.kind) {
1550 case UNBOUND:
1551 break;
1552 case EXTENDS: {
1553 Type bound = wildUpperBound(s);
1554 undetvar.addBound(InferenceBound.UPPER, bound, this);
1555 break;
1556 }
1557 case SUPER: {
1558 Type bound = wildLowerBound(s);
1559 undetvar.addBound(InferenceBound.LOWER, bound, this);
1560 break;
1561 }
1562 }
1563 return true;
1564 } else {
1565 return isSameType(t, s);
1566 }
1567 case ERROR:
1568 return true;
1569 default:
1570 return containsType(s, t);
1571 }
1572 }
1573
1574 boolean containsType(List<Type> ts, List<Type> ss) {
1575 while (ts.nonEmpty() && ss.nonEmpty()
1576 && containsType(ts.head, ss.head)) {
1577 ts = ts.tail;
1578 ss = ss.tail;
1579 }
1580 return ts.isEmpty() && ss.isEmpty();
1581 }
1582
1583 /**
1584 * Check if t contains s.
1585 *
1586 * <p>T contains S if:
1587 *
1588 * <p>{@code L(T) <: L(S) && U(S) <: U(T)}
1589 *
1590 * <p>This relation is only used by ClassType.isSubtype(), that
1591 * is,
1592 *
1593 * <p>{@code C<S> <: C<T> if T contains S.}
1594 *
1595 * <p>Because of F-bounds, this relation can lead to infinite
1596 * recursion. Thus we must somehow break that recursion. Notice
1597 * that containsType() is only called from ClassType.isSubtype().
1598 * Since the arguments have already been checked against their
1599 * bounds, we know:
1600 *
1601 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)}
1602 *
1603 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)}
1604 *
1605 * @param t a type
1606 * @param s a type
1607 */
1608 public boolean containsType(Type t, Type s) {
1609 return containsType.visit(t, s);
1610 }
1611 // where
1612 private TypeRelation containsType = new TypeRelation() {
1613
1614 public Boolean visitType(Type t, Type s) {
1615 if (s.isPartial())
1616 return containedBy(s, t);
1617 else
1618 return isSameType(t, s);
1619 }
1620
1621 // void debugContainsType(WildcardType t, Type s) {
1622 // System.err.println();
1623 // System.err.format(" does %s contain %s?%n", t, s);
1624 // System.err.format(" %s U(%s) <: U(%s) %s = %s%n",
1625 // wildUpperBound(s), s, t, wildUpperBound(t),
1626 // t.isSuperBound()
1627 // || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t)));
1628 // System.err.format(" %s L(%s) <: L(%s) %s = %s%n",
1629 // wildLowerBound(t), t, s, wildLowerBound(s),
1630 // t.isExtendsBound()
1631 // || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s)));
1632 // System.err.println();
1633 // }
1634
1635 @Override
1636 public Boolean visitWildcardType(WildcardType t, Type s) {
1637 if (s.isPartial())
1638 return containedBy(s, t);
1639 else {
1640 // debugContainsType(t, s);
1641
1642 // ----------------------------------- Unspecified behavior ----------------
1643
1644 /* If a primitive class V implements an interface I, then does "? extends I" contain V?
1645 It seems widening must be applied here to answer yes to compile some common code
1646 patterns.
1647 */
1648
1649 // ---------------------------------------------------------------------------
1650 return isSameWildcard(t, s)
1651 || isCaptureOf(s, t)
1652 || ((t.isExtendsBound() || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))) &&
1653 (t.isSuperBound() || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t))));
1654 }
1655 }
1656
1657 @Override
1658 public Boolean visitUndetVar(UndetVar t, Type s) {
1659 if (!s.hasTag(WILDCARD)) {
1660 return isSameType(t, s);
1661 } else {
1662 return false;
1663 }
1664 }
1665
1666 @Override
1667 public Boolean visitErrorType(ErrorType t, Type s) {
1668 return true;
1669 }
1670 };
1671
1672 public boolean isCaptureOf(Type s, WildcardType t) {
1673 if (!s.hasTag(TYPEVAR) || !((TypeVar)s).isCaptured())
1674 return false;
1675 return isSameWildcard(t, ((CapturedType)s).wildcard);
1676 }
1677
1678 public boolean isSameWildcard(WildcardType t, Type s) {
1679 if (!s.hasTag(WILDCARD))
1680 return false;
1681 WildcardType w = (WildcardType)s;
1682 return w.kind == t.kind && w.type == t.type;
1683 }
1684
1685 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) {
1686 while (ts.nonEmpty() && ss.nonEmpty()
1687 && containsTypeEquivalent(ts.head, ss.head)) {
1688 ts = ts.tail;
1689 ss = ss.tail;
1690 }
1691 return ts.isEmpty() && ss.isEmpty();
1692 }
1693 // </editor-fold>
1694
1695 // <editor-fold defaultstate="collapsed" desc="isCastable">
1696 public boolean isCastable(Type t, Type s) {
1697 return isCastable(t, s, noWarnings);
1698 }
1699
1700 /**
1701 * Is t castable to s?<br>
1702 * s is assumed to be an erased type.<br>
1703 * (not defined for Method and ForAll types).
1704 */
1705 public boolean isCastable(Type t, Type s, Warner warn) {
1706 // if same type
1707 if (t == s)
1708 return true;
1709 // if one of the types is primitive
1710 if (t.isPrimitive() != s.isPrimitive()) {
1711 t = skipTypeVars(t, false);
1712 return (isConvertible(t, s, warn)
1713 || (s.isPrimitive() &&
1714 isSubtype(boxedClass(s).type, t)));
1715 }
1716 boolean result;
1717 if (warn != warnStack.head) {
1718 try {
1719 warnStack = warnStack.prepend(warn);
1720 checkUnsafeVarargsConversion(t, s, warn);
1721 result = isCastable.visit(t,s);
1722 } finally {
1723 warnStack = warnStack.tail;
1724 }
1725 } else {
1726 result = isCastable.visit(t,s);
1727 }
1728 if (result && t.hasTag(CLASS) && t.tsym.kind.matches(Kinds.KindSelector.TYP)
1729 && s.hasTag(CLASS) && s.tsym.kind.matches(Kinds.KindSelector.TYP)
1730 && (t.tsym.isSealed() || s.tsym.isSealed())) {
1731 return (t.isCompound() || s.isCompound()) ?
1732 true :
1733 !areDisjoint((ClassSymbol)t.tsym, (ClassSymbol)s.tsym);
1734 }
1735 return result;
1736 }
1737 // where
1738 private boolean areDisjoint(ClassSymbol ts, ClassSymbol ss) {
1739 if (isSubtype(erasure(ts.type.referenceProjectionOrSelf()), erasure(ss.type))) {
1740 return false;
1741 }
1742 // if both are classes or both are interfaces, shortcut
1743 if (ts.isInterface() == ss.isInterface() && isSubtype(erasure(ss.type), erasure(ts.type))) {
1744 return false;
1745 }
1746 if (ts.isInterface() && !ss.isInterface()) {
1747 /* so ts is interface but ss is a class
1748 * an interface is disjoint from a class if the class is disjoint form the interface
1749 */
1750 return areDisjoint(ss, ts);
1751 }
1752 // a final class that is not subtype of ss is disjoint
1753 if (!ts.isInterface() && ts.isFinal()) {
1754 return true;
1755 }
1756 // if at least one is sealed
1757 if (ts.isSealed() || ss.isSealed()) {
1758 // permitted subtypes have to be disjoint with the other symbol
1759 ClassSymbol sealedOne = ts.isSealed() ? ts : ss;
1760 ClassSymbol other = sealedOne == ts ? ss : ts;
1761 return sealedOne.permitted.stream().allMatch(sym -> areDisjoint((ClassSymbol)sym, other));
1762 }
1763 return false;
1764 }
1765
1766 private TypeRelation isCastable = new TypeRelation() {
1767
1768 public Boolean visitType(Type t, Type s) {
1769 if (s.hasTag(ERROR) || t.hasTag(NONE))
1770 return true;
1771
1772 switch (t.getTag()) {
1773 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1774 case DOUBLE:
1775 return s.isNumeric();
1776 case BOOLEAN:
1777 return s.hasTag(BOOLEAN);
1778 case VOID:
1779 return false;
1780 case BOT:
1781 return isSubtype(t, s);
1782 default:
1783 throw new AssertionError();
1784 }
1785 }
1786
1787 @Override
1788 public Boolean visitWildcardType(WildcardType t, Type s) {
1789 return isCastable(wildUpperBound(t), s, warnStack.head);
1790 }
1791
1792 @Override
1793 public Boolean visitClassType(ClassType t, Type s) {
1794 if (s.hasTag(ERROR) || (s.hasTag(BOT) && (!allowPrimitiveClasses || !t.isPrimitiveClass())))
1795 return true;
1796
1797 if (s.hasTag(TYPEVAR)) {
1798 if (isCastable(t, s.getUpperBound(), noWarnings)) {
1799 warnStack.head.warn(LintCategory.UNCHECKED);
1800 return true;
1801 } else {
1802 return false;
1803 }
1804 }
1805
1806 if (t.isCompound() || s.isCompound()) {
1807 return !t.isCompound() ?
1808 visitCompoundType((ClassType)s, t, true) :
1809 visitCompoundType(t, s, false);
1810 }
1811
1812 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) {
1813 if (allowPrimitiveClasses) {
1814 if (t.isPrimitiveClass()) {
1815 // (s) Value ? == (s) Value.ref
1816 t = t.referenceProjection();
1817 }
1818 if (s.isPrimitiveClass()) {
1819 // (Value) t ? == (Value.ref) t
1820 s = s.referenceProjection();
1821 }
1822 }
1823 boolean upcast;
1824 if ((upcast = isSubtype(erasure(t), erasure(s)))
1825 || isSubtype(erasure(s), erasure(t))) {
1826 if (!upcast && s.hasTag(ARRAY)) {
1827 if (!isReifiable(s))
1828 warnStack.head.warn(LintCategory.UNCHECKED);
1829 return true;
1830 } else if (s.isRaw()) {
1831 return true;
1832 } else if (t.isRaw()) {
1833 if (!isUnbounded(s))
1834 warnStack.head.warn(LintCategory.UNCHECKED);
1835 return true;
1836 }
1837 // Assume |a| <: |b|
1838 final Type a = upcast ? t : s;
1839 final Type b = upcast ? s : t;
1840 final boolean HIGH = true;
1841 final boolean LOW = false;
1842 final boolean DONT_REWRITE_TYPEVARS = false;
1843 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS);
1844 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS);
1845 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS);
1846 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS);
1847 Type lowSub = asSub(bLow, aLow.tsym);
1848 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1849 if (highSub == null) {
1850 final boolean REWRITE_TYPEVARS = true;
1851 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS);
1852 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS);
1853 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS);
1854 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS);
1855 lowSub = asSub(bLow, aLow.tsym);
1856 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1857 }
1858 if (highSub != null) {
1859 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) {
1860 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym);
1861 }
1862 if (!disjointTypes(aHigh.allparams(), highSub.allparams())
1863 && !disjointTypes(aHigh.allparams(), lowSub.allparams())
1864 && !disjointTypes(aLow.allparams(), highSub.allparams())
1865 && !disjointTypes(aLow.allparams(), lowSub.allparams())) {
1866 if (upcast ? giveWarning(a, b) :
1867 giveWarning(b, a))
1868 warnStack.head.warn(LintCategory.UNCHECKED);
1869 return true;
1870 }
1871 }
1872 if (isReifiable(s))
1873 return isSubtypeUnchecked(a, b);
1874 else
1875 return isSubtypeUnchecked(a, b, warnStack.head);
1876 }
1877
1878 // Sidecast
1879 if (s.hasTag(CLASS)) {
1880 if ((s.tsym.flags() & INTERFACE) != 0) {
1881 return ((t.tsym.flags() & FINAL) == 0)
1882 ? sideCast(t, s, warnStack.head)
1883 : sideCastFinal(t, s, warnStack.head);
1884 } else if ((t.tsym.flags() & INTERFACE) != 0) {
1885 return ((s.tsym.flags() & FINAL) == 0)
1886 ? sideCast(t, s, warnStack.head)
1887 : sideCastFinal(t, s, warnStack.head);
1888 } else {
1889 // unrelated class types
1890 return false;
1891 }
1892 }
1893 }
1894 return false;
1895 }
1896
1897 boolean visitCompoundType(ClassType ct, Type s, boolean reverse) {
1898 Warner warn = noWarnings;
1899 for (Type c : directSupertypes(ct)) {
1900 warn.clear();
1901 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn))
1902 return false;
1903 }
1904 if (warn.hasLint(LintCategory.UNCHECKED))
1905 warnStack.head.warn(LintCategory.UNCHECKED);
1906 return true;
1907 }
1908
1909 @Override
1910 public Boolean visitArrayType(ArrayType t, Type s) {
1911 switch (s.getTag()) {
1912 case ERROR:
1913 case BOT:
1914 return true;
1915 case TYPEVAR:
1916 if (isCastable(s, t, noWarnings)) {
1917 warnStack.head.warn(LintCategory.UNCHECKED);
1918 return true;
1919 } else {
1920 return false;
1921 }
1922 case CLASS:
1923 return isSubtype(t, s);
1924 case ARRAY:
1925 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) {
1926 return elemtype(t).hasTag(elemtype(s).getTag());
1927 } else {
1928 return isCastable(elemtype(t), elemtype(s), warnStack.head);
1929 }
1930 default:
1931 return false;
1932 }
1933 }
1934
1935 @Override
1936 public Boolean visitTypeVar(TypeVar t, Type s) {
1937 switch (s.getTag()) {
1938 case ERROR:
1939 case BOT:
1940 return true;
1941 case TYPEVAR:
1942 if (isSubtype(t, s)) {
1943 return true;
1944 } else if (isCastable(t.getUpperBound(), s, noWarnings)) {
1945 warnStack.head.warn(LintCategory.UNCHECKED);
1946 return true;
1947 } else {
1948 return false;
1949 }
1950 default:
1951 return isCastable(t.getUpperBound(), s, warnStack.head);
1952 }
1953 }
1954
1955 @Override
1956 public Boolean visitErrorType(ErrorType t, Type s) {
1957 return true;
1958 }
1959 };
1960 // </editor-fold>
1961
1962 // <editor-fold defaultstate="collapsed" desc="disjointTypes">
1963 public boolean disjointTypes(List<Type> ts, List<Type> ss) {
1964 while (ts.tail != null && ss.tail != null) {
1965 if (disjointType(ts.head, ss.head)) return true;
1966 ts = ts.tail;
1967 ss = ss.tail;
1968 }
1969 return false;
1970 }
1971
1972 /**
1973 * Two types or wildcards are considered disjoint if it can be
1974 * proven that no type can be contained in both. It is
1975 * conservative in that it is allowed to say that two types are
1976 * not disjoint, even though they actually are.
1977 *
1978 * The type {@code C<X>} is castable to {@code C<Y>} exactly if
1979 * {@code X} and {@code Y} are not disjoint.
1980 */
1981 public boolean disjointType(Type t, Type s) {
1982 return disjointType.visit(t, s);
1983 }
1984 // where
1985 private TypeRelation disjointType = new TypeRelation() {
1986
1987 private Set<TypePair> cache = new HashSet<>();
1988
1989 @Override
1990 public Boolean visitType(Type t, Type s) {
1991 if (s.hasTag(WILDCARD))
1992 return visit(s, t);
1993 else
1994 return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t);
1995 }
1996
1997 private boolean isCastableRecursive(Type t, Type s) {
1998 TypePair pair = new TypePair(t, s);
1999 if (cache.add(pair)) {
2000 try {
2001 return Types.this.isCastable(t, s);
2002 } finally {
2003 cache.remove(pair);
2004 }
2005 } else {
2006 return true;
2007 }
2008 }
2009
2010 private boolean notSoftSubtypeRecursive(Type t, Type s) {
2011 TypePair pair = new TypePair(t, s);
2012 if (cache.add(pair)) {
2013 try {
2014 return Types.this.notSoftSubtype(t, s);
2015 } finally {
2016 cache.remove(pair);
2017 }
2018 } else {
2019 return false;
2020 }
2021 }
2022
2023 @Override
2024 public Boolean visitWildcardType(WildcardType t, Type s) {
2025 if (t.isUnbound())
2026 return false;
2027
2028 if (!s.hasTag(WILDCARD)) {
2029 if (t.isExtendsBound())
2030 return notSoftSubtypeRecursive(s, t.type);
2031 else
2032 return notSoftSubtypeRecursive(t.type, s);
2033 }
2034
2035 if (s.isUnbound())
2036 return false;
2037
2038 if (t.isExtendsBound()) {
2039 if (s.isExtendsBound())
2040 return !isCastableRecursive(t.type, wildUpperBound(s));
2041 else if (s.isSuperBound())
2042 return notSoftSubtypeRecursive(wildLowerBound(s), t.type);
2043 } else if (t.isSuperBound()) {
2044 if (s.isExtendsBound())
2045 return notSoftSubtypeRecursive(t.type, wildUpperBound(s));
2046 }
2047 return false;
2048 }
2049 };
2050 // </editor-fold>
2051
2052 // <editor-fold defaultstate="collapsed" desc="cvarLowerBounds">
2053 public List<Type> cvarLowerBounds(List<Type> ts) {
2054 return ts.map(cvarLowerBoundMapping);
2055 }
2056 private final TypeMapping<Void> cvarLowerBoundMapping = new TypeMapping<Void>() {
2057 @Override
2058 public Type visitCapturedType(CapturedType t, Void _unused) {
2059 return cvarLowerBound(t);
2060 }
2061 };
2062 // </editor-fold>
2063
2064 // <editor-fold defaultstate="collapsed" desc="notSoftSubtype">
2065 /**
2066 * This relation answers the question: is impossible that
2067 * something of type `t' can be a subtype of `s'? This is
2068 * different from the question "is `t' not a subtype of `s'?"
2069 * when type variables are involved: Integer is not a subtype of T
2070 * where {@code <T extends Number>} but it is not true that Integer cannot
2071 * possibly be a subtype of T.
2072 */
2073 public boolean notSoftSubtype(Type t, Type s) {
2074 if (t == s) return false;
2075 if (t.hasTag(TYPEVAR)) {
2076 TypeVar tv = (TypeVar) t;
2077 return !isCastable(tv.getUpperBound(),
2078 relaxBound(s),
2079 noWarnings);
2080 }
2081 if (!s.hasTag(WILDCARD))
2082 s = cvarUpperBound(s);
2083
2084 return !isSubtype(t, relaxBound(s));
2085 }
2086
2087 private Type relaxBound(Type t) {
2088 return (t.hasTag(TYPEVAR)) ?
2089 rewriteQuantifiers(skipTypeVars(t, false), true, true) :
2090 t;
2091 }
2092 // </editor-fold>
2093
2094 // <editor-fold defaultstate="collapsed" desc="isReifiable">
2095 public boolean isReifiable(Type t) {
2096 return isReifiable.visit(t);
2097 }
2098 // where
2099 private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() {
2100
2101 public Boolean visitType(Type t, Void ignored) {
2102 return true;
2103 }
2104
2105 @Override
2106 public Boolean visitClassType(ClassType t, Void ignored) {
2107 if (t.isCompound())
2108 return false;
2109 else {
2110 if (!t.isParameterized())
2111 return true;
2112
2113 for (Type param : t.allparams()) {
2114 if (!param.isUnbound())
2115 return false;
2116 }
2117 return true;
2118 }
2119 }
2120
2121 @Override
2122 public Boolean visitArrayType(ArrayType t, Void ignored) {
2123 return visit(t.elemtype);
2124 }
2125
2126 @Override
2127 public Boolean visitTypeVar(TypeVar t, Void ignored) {
2128 return false;
2129 }
2130 };
2131 // </editor-fold>
2132
2133 // <editor-fold defaultstate="collapsed" desc="Array Utils">
2134 public boolean isArray(Type t) {
2135 while (t.hasTag(WILDCARD))
2136 t = wildUpperBound(t);
2137 return t.hasTag(ARRAY);
2138 }
2139
2140 /**
2141 * The element type of an array.
2142 */
2143 public Type elemtype(Type t) {
2144 switch (t.getTag()) {
2145 case WILDCARD:
2146 return elemtype(wildUpperBound(t));
2147 case ARRAY:
2148 return ((ArrayType)t).elemtype;
2149 case FORALL:
2150 return elemtype(((ForAll)t).qtype);
2151 case ERROR:
2152 return t;
2153 default:
2154 return null;
2155 }
2156 }
2157
2158 public Type elemtypeOrType(Type t) {
2159 Type elemtype = elemtype(t);
2160 return elemtype != null ?
2161 elemtype :
2162 t;
2163 }
2164
2165 /**
2166 * Mapping to take element type of an arraytype
2167 */
2168 private TypeMapping<Void> elemTypeFun = new TypeMapping<Void>() {
2169 @Override
2170 public Type visitArrayType(ArrayType t, Void _unused) {
2171 return t.elemtype;
2172 }
2173
2174 @Override
2175 public Type visitTypeVar(TypeVar t, Void _unused) {
2176 return visit(skipTypeVars(t, false));
2177 }
2178 };
2179
2180 /**
2181 * The number of dimensions of an array type.
2182 */
2183 public int dimensions(Type t) {
2184 int result = 0;
2185 while (t.hasTag(ARRAY)) {
2186 result++;
2187 t = elemtype(t);
2188 }
2189 return result;
2190 }
2191
2192 /**
2193 * Returns an ArrayType with the component type t
2194 *
2195 * @param t The component type of the ArrayType
2196 * @return the ArrayType for the given component
2197 */
2198 public ArrayType makeArrayType(Type t) {
2199 if (t.hasTag(VOID) || t.hasTag(PACKAGE)) {
2200 Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString());
2201 }
2202 return new ArrayType(t, syms.arrayClass);
2203 }
2204 // </editor-fold>
2205
2206 // <editor-fold defaultstate="collapsed" desc="asSuper">
2207 /**
2208 * Return the (most specific) base type of t that starts with the
2209 * given symbol. If none exists, return null.
2210 *
2211 * Caveat Emptor: Since javac represents the class of all arrays with a singleton
2212 * symbol Symtab.arrayClass, which by being a singleton cannot hold any discriminant,
2213 * this method could yield surprising answers when invoked on arrays. For example when
2214 * invoked with t being byte [] and sym being t.sym itself, asSuper would answer null.
2215 *
2216 * Further caveats in Valhalla: There are two "hazards" we need to watch out for when using
2217 * this method.
2218 *
2219 * 1. Since Foo.ref and Foo.val share the same symbol, that of Foo.class, a call to
2220 * asSuper(Foo.ref.type, Foo.val.type.tsym) would return non-null. This MAY NOT BE correct
2221 * depending on the call site. Foo.val is NOT a super type of Foo.ref either in the language
2222 * model or in the VM's world view. An example of such an hazardous call used to exist in
2223 * Gen.visitTypeCast. When we emit code for (Foo) Foo.ref.instance a check for whether we
2224 * really need the cast cannot/shouldn't be gated on
2225 *
2226 * asSuper(tree.expr.type, tree.clazz.type.tsym) == null)
2227 *
2228 * but use !types.isSubtype(tree.expr.type, tree.clazz.type) which operates in terms of
2229 * types. When we operate in terms of symbols, there is a loss of type information leading
2230 * to a hazard. Whether a call to asSuper should be transformed into a isSubtype call is
2231 * tricky. isSubtype returns just a boolean while asSuper returns richer information which
2232 * may be required at the call site. Also where the concerned symbol corresponds to a
2233 * generic class, an asSuper call cannot be conveniently rewritten as an isSubtype call
2234 * (see that asSuper(ArrayList<String>.type, List<T>.tsym) != null while
2235 * isSubType(ArrayList<String>.type, List<T>.type) is false;) So care needs to be exercised.
2236 *
2237 * 2. Given a primitive class Foo, a call to asSuper(Foo.type, SuperclassOfFoo.tsym) and/or
2238 * a call to asSuper(Foo.type, SuperinterfaceOfFoo.tsym) would answer null. In many places
2239 * that is NOT what we want. An example of such a hazardous call used to occur in
2240 * Attr.visitForeachLoop when checking to make sure the for loop's control variable of a type
2241 * that implements Iterable: viz: types.asSuper(exprType, syms.iterableType.tsym);
2242 * These hazardous calls should be rewritten as
2243 * types.asSuper(exprType.referenceProjectionOrSelf(), syms.iterableType.tsym); instead.
2244 *
2245 * @param t a type
2246 * @param sym a symbol
2247 */
2248 public Type asSuper(Type t, Symbol sym) {
2249 /* Some examples:
2250 *
2251 * (Enum<E>, Comparable) => Comparable<E>
2252 * (c.s.s.d.AttributeTree.ValueKind, Enum) => Enum<c.s.s.d.AttributeTree.ValueKind>
2253 * (c.s.s.t.ExpressionTree, c.s.s.t.Tree) => c.s.s.t.Tree
2254 * (j.u.List<capture#160 of ? extends c.s.s.d.DocTree>, Iterable) =>
2255 * Iterable<capture#160 of ? extends c.s.s.d.DocTree>
2256 */
2257
2258 if (allowPrimitiveClasses && t.isPrimitiveClass()) {
2259 // No man may be an island, but the bell tolls for a value.
2260 return t.tsym == sym ? t : null;
2261 }
2262
2263 if (sym.type == syms.objectType) { //optimization
2264 return syms.objectType;
2265 }
2266 return asSuper.visit(t, sym);
2267 }
2268 // where
2269 private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() {
2270
2271 private Set<Symbol> seenTypes = new HashSet<>();
2272
2273 public Type visitType(Type t, Symbol sym) {
2274 return null;
2275 }
2276
2277 @Override
2278 public Type visitClassType(ClassType t, Symbol sym) {
2279 if (t.tsym == sym)
2280 return t;
2281
2282 Symbol c = t.tsym;
2283 if (!seenTypes.add(c)) {
2284 return null;
2285 }
2286 try {
2287 Type st = supertype(t);
2288 if (st.hasTag(CLASS) || st.hasTag(TYPEVAR)) {
2289 Type x = asSuper(st, sym);
2290 if (x != null)
2291 return x;
2292 }
2293 if ((sym.flags() & INTERFACE) != 0) {
2294 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
2295 if (!l.head.hasTag(ERROR)) {
2296 Type x = asSuper(l.head, sym);
2297 if (x != null)
2298 return x;
2299 }
2300 }
2301 }
2302 return null;
2303 } finally {
2304 seenTypes.remove(c);
2305 }
2306 }
2307
2308 @Override
2309 public Type visitArrayType(ArrayType t, Symbol sym) {
2310 return isSubtype(t, sym.type) ? sym.type : null;
2311 }
2312
2313 @Override
2314 public Type visitTypeVar(TypeVar t, Symbol sym) {
2315 if (t.tsym == sym)
2316 return t;
2317 else
2318 return asSuper(t.getUpperBound(), sym);
2319 }
2320
2321 @Override
2322 public Type visitErrorType(ErrorType t, Symbol sym) {
2323 return t;
2324 }
2325 };
2326
2327 /**
2328 * Return the base type of t or any of its outer types that starts
2329 * with the given symbol. If none exists, return null.
2330 *
2331 * @param t a type
2332 * @param sym a symbol
2333 */
2334 public Type asOuterSuper(Type t, Symbol sym) {
2335 switch (t.getTag()) {
2336 case CLASS:
2337 do {
2338 Type s = asSuper(t, sym);
2339 if (s != null) return s;
2340 t = t.getEnclosingType();
2341 } while (t.hasTag(CLASS));
2342 return null;
2343 case ARRAY:
2344 return isSubtype(t, sym.type) ? sym.type : null;
2345 case TYPEVAR:
2346 return asSuper(t, sym);
2347 case ERROR:
2348 return t;
2349 default:
2350 return null;
2351 }
2352 }
2353
2354 /**
2355 * Return the base type of t or any of its enclosing types that
2356 * starts with the given symbol. If none exists, return null.
2357 *
2358 * @param t a type
2359 * @param sym a symbol
2360 */
2361 public Type asEnclosingSuper(Type t, Symbol sym) {
2362 switch (t.getTag()) {
2363 case CLASS:
2364 do {
2365 Type s = asSuper(t, sym);
2366 if (s != null) return s;
2367 Type outer = t.getEnclosingType();
2368 t = (outer.hasTag(CLASS)) ? outer :
2369 (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type :
2370 Type.noType;
2371 } while (t.hasTag(CLASS));
2372 return null;
2373 case ARRAY:
2374 return isSubtype(t, sym.type) ? sym.type : null;
2375 case TYPEVAR:
2376 return asSuper(t, sym);
2377 case ERROR:
2378 return t;
2379 default:
2380 return null;
2381 }
2382 }
2383 // </editor-fold>
2384
2385 // <editor-fold defaultstate="collapsed" desc="memberType">
2386 /**
2387 * The type of given symbol, seen as a member of t.
2388 *
2389 * @param t a type
2390 * @param sym a symbol
2391 */
2392 public Type memberType(Type t, Symbol sym) {
2393
2394 if ((sym.flags() & STATIC) != 0)
2395 return sym.type;
2396
2397 /* If any primitive class types are involved, switch over to the reference universe,
2398 where the hierarchy is navigable. V and V.ref have identical membership
2399 with no bridging needs.
2400 */
2401 if (allowPrimitiveClasses && t.isPrimitiveClass())
2402 t = t.referenceProjection();
2403
2404 return memberType.visit(t, sym);
2405 }
2406 // where
2407 private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() {
2408
2409 public Type visitType(Type t, Symbol sym) {
2410 return sym.type;
2411 }
2412
2413 @Override
2414 public Type visitWildcardType(WildcardType t, Symbol sym) {
2415 return memberType(wildUpperBound(t), sym);
2416 }
2417
2418 @Override
2419 public Type visitClassType(ClassType t, Symbol sym) {
2420 Symbol owner = sym.owner;
2421 long flags = sym.flags();
2422 if (((flags & STATIC) == 0) && owner.type.isParameterized()) {
2423 Type base = asOuterSuper(t, owner);
2424 //if t is an intersection type T = CT & I1 & I2 ... & In
2425 //its supertypes CT, I1, ... In might contain wildcards
2426 //so we need to go through capture conversion
2427 base = t.isCompound() ? capture(base) : base;
2428 if (base != null) {
2429 List<Type> ownerParams = owner.type.allparams();
2430 List<Type> baseParams = base.allparams();
2431 if (ownerParams.nonEmpty()) {
2432 if (baseParams.isEmpty()) {
2433 // then base is a raw type
2434 return erasure(sym.type);
2435 } else {
2436 return subst(sym.type, ownerParams, baseParams);
2437 }
2438 }
2439 }
2440 }
2441 return sym.type;
2442 }
2443
2444 @Override
2445 public Type visitTypeVar(TypeVar t, Symbol sym) {
2446 return memberType(t.getUpperBound(), sym);
2447 }
2448
2449 @Override
2450 public Type visitErrorType(ErrorType t, Symbol sym) {
2451 return t;
2452 }
2453 };
2454 // </editor-fold>
2455
2456 // <editor-fold defaultstate="collapsed" desc="isAssignable">
2457 public boolean isAssignable(Type t, Type s) {
2458 return isAssignable(t, s, noWarnings);
2459 }
2460
2461 /**
2462 * Is t assignable to s?<br>
2463 * Equivalent to subtype except for constant values and raw
2464 * types.<br>
2465 * (not defined for Method and ForAll types)
2466 */
2467 public boolean isAssignable(Type t, Type s, Warner warn) {
2468 if (t.hasTag(ERROR))
2469 return true;
2470 if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) {
2471 int value = ((Number)t.constValue()).intValue();
2472 switch (s.getTag()) {
2473 case BYTE:
2474 case CHAR:
2475 case SHORT:
2476 case INT:
2477 if (s.getTag().checkRange(value))
2478 return true;
2479 break;
2480 case CLASS:
2481 switch (unboxedType(s).getTag()) {
2482 case BYTE:
2483 case CHAR:
2484 case SHORT:
2485 return isAssignable(t, unboxedType(s), warn);
2486 }
2487 break;
2488 }
2489 }
2490 return isConvertible(t, s, warn);
2491 }
2492 // </editor-fold>
2493
2494 // <editor-fold defaultstate="collapsed" desc="erasure">
2495 /**
2496 * The erasure of t {@code |t|} -- the type that results when all
2497 * type parameters in t are deleted.
2498 */
2499 public Type erasure(Type t) {
2500 return eraseNotNeeded(t) ? t : erasure(t, false);
2501 }
2502 //where
2503 private boolean eraseNotNeeded(Type t) {
2504 // We don't want to erase primitive types and String type as that
2505 // operation is idempotent. Also, erasing these could result in loss
2506 // of information such as constant values attached to such types.
2507 return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym);
2508 }
2509
2510 private Type erasure(Type t, boolean recurse) {
2511 if (t.isPrimitive()) {
2512 return t; /* fast special case */
2513 } else {
2514 Type out = erasure.visit(t, recurse);
2515 return out;
2516 }
2517 }
2518 // where
2519 private TypeMapping<Boolean> erasure = new StructuralTypeMapping<Boolean>() {
2520 private Type combineMetadata(final Type s,
2521 final Type t) {
2522 if (t.getMetadata().nonEmpty()) {
2523 switch (s.getKind()) {
2524 case OTHER:
2525 case UNION:
2526 case INTERSECTION:
2527 case PACKAGE:
2528 case EXECUTABLE:
2529 case NONE:
2530 case VOID:
2531 case ERROR:
2532 return s;
2533 default: return s.dropMetadata(Annotations.class);
2534 }
2535 } else {
2536 return s;
2537 }
2538 }
2539
2540 public Type visitType(Type t, Boolean recurse) {
2541 if (t.isPrimitive())
2542 return t; /*fast special case*/
2543 else {
2544 //other cases already handled
2545 return combineMetadata(t, t);
2546 }
2547 }
2548
2549 @Override
2550 public Type visitWildcardType(WildcardType t, Boolean recurse) {
2551 Type erased = erasure(wildUpperBound(t), recurse);
2552 return combineMetadata(erased, t);
2553 }
2554
2555 @Override
2556 public Type visitClassType(ClassType t, Boolean recurse) {
2557 // erasure(projection(primitive)) = projection(erasure(primitive))
2558 Type erased = eraseClassType(t, recurse);
2559 if (erased.hasTag(CLASS) && t.flavor != erased.getFlavor()) {
2560 erased = new ClassType(erased.getEnclosingType(),
2561 List.nil(), erased.tsym,
2562 erased.getMetadata(), t.flavor);
2563 }
2564 return erased;
2565 }
2566 // where
2567 private Type eraseClassType(ClassType t, Boolean recurse) {
2568 Type erased = t.tsym.erasure(Types.this);
2569 if (recurse) {
2570 erased = new ErasedClassType(erased.getEnclosingType(), erased.tsym,
2571 t.dropMetadata(Annotations.class).getMetadata());
2572 return erased;
2573 } else {
2574 return combineMetadata(erased, t);
2575 }
2576 }
2577
2578 @Override
2579 public Type visitTypeVar(TypeVar t, Boolean recurse) {
2580 Type erased = erasure(t.getUpperBound(), recurse);
2581 return combineMetadata(erased, t);
2582 }
2583 };
2584
2585 public List<Type> erasure(List<Type> ts) {
2586 return erasure.visit(ts, false);
2587 }
2588
2589 public Type erasureRecursive(Type t) {
2590 return erasure(t, true);
2591 }
2592
2593 public List<Type> erasureRecursive(List<Type> ts) {
2594 return erasure.visit(ts, true);
2595 }
2596 // </editor-fold>
2597
2598 // <editor-fold defaultstate="collapsed" desc="makeIntersectionType">
2599 /**
2600 * Make an intersection type from non-empty list of types. The list should be ordered according to
2601 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. Note that this might cause a symbol completion.
2602 * Hence, this version of makeIntersectionType may not be called during a classfile read.
2603 *
2604 * @param bounds the types from which the intersection type is formed
2605 */
2606 public IntersectionClassType makeIntersectionType(List<Type> bounds) {
2607 return makeIntersectionType(bounds, bounds.head.tsym.isInterface());
2608 }
2609
2610 /**
2611 * Make an intersection type from non-empty list of types. The list should be ordered according to
2612 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. This does not cause symbol completion as
2613 * an extra parameter indicates as to whether all bounds are interfaces - in which case the
2614 * supertype is implicitly assumed to be 'Object'.
2615 *
2616 * @param bounds the types from which the intersection type is formed
2617 * @param allInterfaces are all bounds interface types?
2618 */
2619 public IntersectionClassType makeIntersectionType(List<Type> bounds, boolean allInterfaces) {
2620 Assert.check(bounds.nonEmpty());
2621 Type firstExplicitBound = bounds.head;
2622 if (allInterfaces) {
2623 bounds = bounds.prepend(syms.objectType);
2624 }
2625 ClassSymbol bc =
2626 new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC,
2627 Type.moreInfo
2628 ? names.fromString(bounds.toString())
2629 : names.empty,
2630 null,
2631 syms.noSymbol);
2632 IntersectionClassType intersectionType = new IntersectionClassType(bounds, bc, allInterfaces);
2633 bc.type = intersectionType;
2634 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ?
2635 syms.objectType : // error condition, recover
2636 erasure(firstExplicitBound);
2637 bc.members_field = WriteableScope.create(bc);
2638 return intersectionType;
2639 }
2640 // </editor-fold>
2641
2642 // <editor-fold defaultstate="collapsed" desc="supertype">
2643 public Type supertype(Type t) {
2644 return supertype.visit(t);
2645 }
2646 // where
2647 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() {
2648
2649 public Type visitType(Type t, Void ignored) {
2650 // A note on wildcards: there is no good way to
2651 // determine a supertype for a lower-bounded wildcard.
2652 return Type.noType;
2653 }
2654
2655 @Override
2656 public Type visitClassType(ClassType t, Void ignored) {
2657 if (t.supertype_field == null) {
2658 Type supertype = ((ClassSymbol)t.tsym).getSuperclass();
2659 // An interface has no superclass; its supertype is Object.
2660 if (t.isInterface())
2661 supertype = ((ClassType)t.tsym.type).supertype_field;
2662 if (t.supertype_field == null) {
2663 List<Type> actuals = classBound(t).allparams();
2664 List<Type> formals = t.tsym.type.allparams();
2665 if (t.hasErasedSupertypes()) {
2666 t.supertype_field = erasureRecursive(supertype);
2667 } else if (formals.nonEmpty()) {
2668 t.supertype_field = subst(supertype, formals, actuals);
2669 }
2670 else {
2671 t.supertype_field = supertype;
2672 }
2673 }
2674 }
2675 return t.supertype_field;
2676 }
2677
2678 /**
2679 * The supertype is always a class type. If the type
2680 * variable's bounds start with a class type, this is also
2681 * the supertype. Otherwise, the supertype is
2682 * java.lang.Object.
2683 */
2684 @Override
2685 public Type visitTypeVar(TypeVar t, Void ignored) {
2686 if (t.getUpperBound().hasTag(TYPEVAR) ||
2687 (!t.getUpperBound().isCompound() && !t.getUpperBound().isInterface())) {
2688 return t.getUpperBound();
2689 } else {
2690 return supertype(t.getUpperBound());
2691 }
2692 }
2693
2694 @Override
2695 public Type visitArrayType(ArrayType t, Void ignored) {
2696 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType))
2697 return arraySuperType();
2698 else
2699 return new ArrayType(supertype(t.elemtype), t.tsym);
2700 }
2701
2702 @Override
2703 public Type visitErrorType(ErrorType t, Void ignored) {
2704 return Type.noType;
2705 }
2706 };
2707 // </editor-fold>
2708
2709 // <editor-fold defaultstate="collapsed" desc="interfaces">
2710 /**
2711 * Return the interfaces implemented by this class.
2712 */
2713 public List<Type> interfaces(Type t) {
2714 return interfaces.visit(t);
2715 }
2716 // where
2717 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() {
2718
2719 public List<Type> visitType(Type t, Void ignored) {
2720 return List.nil();
2721 }
2722
2723 @Override
2724 public List<Type> visitClassType(ClassType t, Void ignored) {
2725 if (t.interfaces_field == null) {
2726 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces();
2727 if (t.interfaces_field == null) {
2728 // If t.interfaces_field is null, then t must
2729 // be a parameterized type (not to be confused
2730 // with a generic type declaration).
2731 // Terminology:
2732 // Parameterized type: List<String>
2733 // Generic type declaration: class List<E> { ... }
2734 // So t corresponds to List<String> and
2735 // t.tsym.type corresponds to List<E>.
2736 // The reason t must be parameterized type is
2737 // that completion will happen as a side
2738 // effect of calling
2739 // ClassSymbol.getInterfaces. Since
2740 // t.interfaces_field is null after
2741 // completion, we can assume that t is not the
2742 // type of a class/interface declaration.
2743 Assert.check(t != t.tsym.type, t);
2744 List<Type> actuals = t.allparams();
2745 List<Type> formals = t.tsym.type.allparams();
2746 if (t.hasErasedSupertypes()) {
2747 t.interfaces_field = erasureRecursive(interfaces);
2748 } else if (formals.nonEmpty()) {
2749 t.interfaces_field = subst(interfaces, formals, actuals);
2750 }
2751 else {
2752 t.interfaces_field = interfaces;
2753 }
2754 }
2755 }
2756 return t.interfaces_field;
2757 }
2758
2759 @Override
2760 public List<Type> visitTypeVar(TypeVar t, Void ignored) {
2761 if (t.getUpperBound().isCompound())
2762 return interfaces(t.getUpperBound());
2763
2764 if (t.getUpperBound().isInterface())
2765 return List.of(t.getUpperBound());
2766
2767 return List.nil();
2768 }
2769 };
2770
2771 public List<Type> directSupertypes(Type t) {
2772 return directSupertypes.visit(t);
2773 }
2774 // where
2775 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() {
2776
2777 public List<Type> visitType(final Type type, final Void ignored) {
2778 if (!type.isIntersection()) {
2779 final Type sup = supertype(type);
2780 return (sup == Type.noType || sup == type || sup == null)
2781 ? interfaces(type)
2782 : interfaces(type).prepend(sup);
2783 } else {
2784 return ((IntersectionClassType)type).getExplicitComponents();
2785 }
2786 }
2787 };
2788
2789 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) {
2790 for (Type i2 : interfaces(origin.type)) {
2791 if (isym == i2.tsym) return true;
2792 }
2793 return false;
2794 }
2795 // </editor-fold>
2796
2797 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw">
2798 Map<Type,Boolean> isDerivedRawCache = new HashMap<>();
2799
2800 public boolean isDerivedRaw(Type t) {
2801 Boolean result = isDerivedRawCache.get(t);
2802 if (result == null) {
2803 result = isDerivedRawInternal(t);
2804 isDerivedRawCache.put(t, result);
2805 }
2806 return result;
2807 }
2808
2809 public boolean isDerivedRawInternal(Type t) {
2810 if (t.isErroneous())
2811 return false;
2812 return
2813 t.isRaw() ||
2814 supertype(t) != Type.noType && isDerivedRaw(supertype(t)) ||
2815 isDerivedRaw(interfaces(t));
2816 }
2817
2818 public boolean isDerivedRaw(List<Type> ts) {
2819 List<Type> l = ts;
2820 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail;
2821 return l.nonEmpty();
2822 }
2823 // </editor-fold>
2824
2825 // <editor-fold defaultstate="collapsed" desc="setBounds">
2826 /**
2827 * Same as {@link Types#setBounds(TypeVar, List, boolean)}, except that third parameter is computed directly,
2828 * as follows: if all all bounds are interface types, the computed supertype is Object,otherwise
2829 * the supertype is simply left null (in this case, the supertype is assumed to be the head of
2830 * the bound list passed as second argument). Note that this check might cause a symbol completion.
2831 * Hence, this version of setBounds may not be called during a classfile read.
2832 *
2833 * @param t a type variable
2834 * @param bounds the bounds, must be nonempty
2835 */
2836 public void setBounds(TypeVar t, List<Type> bounds) {
2837 setBounds(t, bounds, bounds.head.tsym.isInterface());
2838 }
2839
2840 /**
2841 * Set the bounds field of the given type variable to reflect a (possibly multiple) list of bounds.
2842 * This does not cause symbol completion as an extra parameter indicates as to whether all bounds
2843 * are interfaces - in which case the supertype is implicitly assumed to be 'Object'.
2844 *
2845 * @param t a type variable
2846 * @param bounds the bounds, must be nonempty
2847 * @param allInterfaces are all bounds interface types?
2848 */
2849 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) {
2850 t.setUpperBound( bounds.tail.isEmpty() ?
2851 bounds.head :
2852 makeIntersectionType(bounds, allInterfaces) );
2853 t.rank_field = -1;
2854 }
2855 // </editor-fold>
2856
2857 // <editor-fold defaultstate="collapsed" desc="getBounds">
2858 /**
2859 * Return list of bounds of the given type variable.
2860 */
2861 public List<Type> getBounds(TypeVar t) {
2862 if (t.getUpperBound().hasTag(NONE))
2863 return List.nil();
2864 else if (t.getUpperBound().isErroneous() || !t.getUpperBound().isCompound())
2865 return List.of(t.getUpperBound());
2866 else if ((erasure(t).tsym.flags() & INTERFACE) == 0)
2867 return interfaces(t).prepend(supertype(t));
2868 else
2869 // No superclass was given in bounds.
2870 // In this case, supertype is Object, erasure is first interface.
2871 return interfaces(t);
2872 }
2873 // </editor-fold>
2874
2875 // <editor-fold defaultstate="collapsed" desc="classBound">
2876 /**
2877 * If the given type is a (possibly selected) type variable,
2878 * return the bounding class of this type, otherwise return the
2879 * type itself.
2880 */
2881 public Type classBound(Type t) {
2882 return classBound.visit(t);
2883 }
2884 // where
2885 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() {
2886
2887 public Type visitType(Type t, Void ignored) {
2888 return t;
2889 }
2890
2891 @Override
2892 public Type visitClassType(ClassType t, Void ignored) {
2893 Type outer1 = classBound(t.getEnclosingType());
2894 if (outer1 != t.getEnclosingType())
2895 return new ClassType(outer1, t.getTypeArguments(), t.tsym,
2896 t.getMetadata(), t.getFlavor());
2897 else
2898 return t;
2899 }
2900
2901 @Override
2902 public Type visitTypeVar(TypeVar t, Void ignored) {
2903 return classBound(supertype(t));
2904 }
2905
2906 @Override
2907 public Type visitErrorType(ErrorType t, Void ignored) {
2908 return t;
2909 }
2910 };
2911 // </editor-fold>
2912
2913 // <editor-fold defaultstate="collapsed" desc="subsignature / override equivalence">
2914 /**
2915 * Returns true iff the first signature is a <em>subsignature</em>
2916 * of the other. This is <b>not</b> an equivalence
2917 * relation.
2918 *
2919 * @jls 8.4.2 Method Signature
2920 * @see #overrideEquivalent(Type t, Type s)
2921 * @param t first signature (possibly raw).
2922 * @param s second signature (could be subjected to erasure).
2923 * @return true if t is a subsignature of s.
2924 */
2925 public boolean isSubSignature(Type t, Type s) {
2926 return hasSameArgs(t, s, true) || hasSameArgs(t, erasure(s), true);
2927 }
2928
2929 /**
2930 * Returns true iff these signatures are related by <em>override
2931 * equivalence</em>. This is the natural extension of
2932 * isSubSignature to an equivalence relation.
2933 *
2934 * @jls 8.4.2 Method Signature
2935 * @see #isSubSignature(Type t, Type s)
2936 * @param t a signature (possible raw, could be subjected to
2937 * erasure).
2938 * @param s a signature (possible raw, could be subjected to
2939 * erasure).
2940 * @return true if either argument is a subsignature of the other.
2941 */
2942 public boolean overrideEquivalent(Type t, Type s) {
2943 return hasSameArgs(t, s) ||
2944 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s);
2945 }
2946
2947 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) {
2948 for (Symbol sym : syms.objectType.tsym.members().getSymbolsByName(msym.name)) {
2949 if (msym.overrides(sym, origin, Types.this, true)) {
2950 return true;
2951 }
2952 }
2953 return false;
2954 }
2955
2956 /**
2957 * This enum defines the strategy for implementing most specific return type check
2958 * during the most specific and functional interface checks.
2959 */
2960 public enum MostSpecificReturnCheck {
2961 /**
2962 * Return r1 is more specific than r2 if {@code r1 <: r2}. Extra care required for (i) handling
2963 * method type variables (if either method is generic) and (ii) subtyping should be replaced
2964 * by type-equivalence for primitives. This is essentially an inlined version of
2965 * {@link Types#resultSubtype(Type, Type, Warner)}, where the assignability check has been
2966 * replaced with a strict subtyping check.
2967 */
2968 BASIC() {
2969 @Override
2970 public boolean test(Type mt1, Type mt2, Types types) {
2971 List<Type> tvars = mt1.getTypeArguments();
2972 List<Type> svars = mt2.getTypeArguments();
2973 Type t = mt1.getReturnType();
2974 Type s = types.subst(mt2.getReturnType(), svars, tvars);
2975 return types.isSameType(t, s) ||
2976 !t.isPrimitive() &&
2977 !s.isPrimitive() &&
2978 types.isSubtype(t, s);
2979 }
2980 },
2981 /**
2982 * Return r1 is more specific than r2 if r1 is return-type-substitutable for r2.
2983 */
2984 RTS() {
2985 @Override
2986 public boolean test(Type mt1, Type mt2, Types types) {
2987 return types.returnTypeSubstitutable(mt1, mt2);
2988 }
2989 };
2990
2991 public abstract boolean test(Type mt1, Type mt2, Types types);
2992 }
2993
2994 /**
2995 * Merge multiple abstract methods. The preferred method is a method that is a subsignature
2996 * of all the other signatures and whose return type is more specific {@link MostSpecificReturnCheck}.
2997 * The resulting preferred method has a throws clause that is the intersection of the merged
2998 * methods' clauses.
2999 */
3000 public Optional<Symbol> mergeAbstracts(List<Symbol> ambiguousInOrder, Type site, boolean sigCheck) {
3001 //first check for preconditions
3002 boolean shouldErase = false;
3003 List<Type> erasedParams = ambiguousInOrder.head.erasure(this).getParameterTypes();
3004 for (Symbol s : ambiguousInOrder) {
3005 if ((s.flags() & ABSTRACT) == 0 ||
3006 (sigCheck && !isSameTypes(erasedParams, s.erasure(this).getParameterTypes()))) {
3007 return Optional.empty();
3008 } else if (s.type.hasTag(FORALL)) {
3009 shouldErase = true;
3010 }
3011 }
3012 //then merge abstracts
3013 for (MostSpecificReturnCheck mostSpecificReturnCheck : MostSpecificReturnCheck.values()) {
3014 outer: for (Symbol s : ambiguousInOrder) {
3015 Type mt = memberType(site, s);
3016 List<Type> allThrown = mt.getThrownTypes();
3017 for (Symbol s2 : ambiguousInOrder) {
3018 if (s != s2) {
3019 Type mt2 = memberType(site, s2);
3020 if (!isSubSignature(mt, mt2) ||
3021 !mostSpecificReturnCheck.test(mt, mt2, this)) {
3022 //ambiguity cannot be resolved
3023 continue outer;
3024 } else {
3025 List<Type> thrownTypes2 = mt2.getThrownTypes();
3026 if (!mt.hasTag(FORALL) && shouldErase) {
3027 thrownTypes2 = erasure(thrownTypes2);
3028 } else if (mt.hasTag(FORALL)) {
3029 //subsignature implies that if most specific is generic, then all other
3030 //methods are too
3031 Assert.check(mt2.hasTag(FORALL));
3032 // if both are generic methods, adjust thrown types ahead of intersection computation
3033 thrownTypes2 = subst(thrownTypes2, mt2.getTypeArguments(), mt.getTypeArguments());
3034 }
3035 allThrown = chk.intersect(allThrown, thrownTypes2);
3036 }
3037 }
3038 }
3039 return (allThrown == mt.getThrownTypes()) ?
3040 Optional.of(s) :
3041 Optional.of(new MethodSymbol(
3042 s.flags(),
3043 s.name,
3044 createMethodTypeWithThrown(s.type, allThrown),
3045 s.owner) {
3046 @Override
3047 public Symbol baseSymbol() {
3048 return s;
3049 }
3050 });
3051 }
3052 }
3053 return Optional.empty();
3054 }
3055
3056 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site">
3057 class ImplementationCache {
3058
3059 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map = new WeakHashMap<>();
3060
3061 class Entry {
3062 final MethodSymbol cachedImpl;
3063 final Predicate<Symbol> implFilter;
3064 final boolean checkResult;
3065 final int prevMark;
3066
3067 public Entry(MethodSymbol cachedImpl,
3068 Predicate<Symbol> scopeFilter,
3069 boolean checkResult,
3070 int prevMark) {
3071 this.cachedImpl = cachedImpl;
3072 this.implFilter = scopeFilter;
3073 this.checkResult = checkResult;
3074 this.prevMark = prevMark;
3075 }
3076
3077 boolean matches(Predicate<Symbol> scopeFilter, boolean checkResult, int mark) {
3078 return this.implFilter == scopeFilter &&
3079 this.checkResult == checkResult &&
3080 this.prevMark == mark;
3081 }
3082 }
3083
3084 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3085 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms);
3086 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null;
3087 if (cache == null) {
3088 cache = new HashMap<>();
3089 _map.put(ms, new SoftReference<>(cache));
3090 }
3091 Entry e = cache.get(origin);
3092 CompoundScope members = membersClosure(origin.type, true);
3093 if (e == null ||
3094 !e.matches(implFilter, checkResult, members.getMark())) {
3095 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter);
3096 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark()));
3097 return impl;
3098 }
3099 else {
3100 return e.cachedImpl;
3101 }
3102 }
3103
3104 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3105 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) {
3106 t = skipTypeVars(t, false);
3107 TypeSymbol c = t.tsym;
3108 Symbol bestSoFar = null;
3109 for (Symbol sym : c.members().getSymbolsByName(ms.name, implFilter)) {
3110 if (sym != null && sym.overrides(ms, origin, Types.this, checkResult)) {
3111 bestSoFar = sym;
3112 if ((sym.flags() & ABSTRACT) == 0) {
3113 //if concrete impl is found, exit immediately
3114 break;
3115 }
3116 }
3117 }
3118 if (bestSoFar != null) {
3119 //return either the (only) concrete implementation or the first abstract one
3120 return (MethodSymbol)bestSoFar;
3121 }
3122 }
3123 return null;
3124 }
3125 }
3126
3127 private ImplementationCache implCache = new ImplementationCache();
3128
3129 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3130 return implCache.get(ms, origin, checkResult, implFilter);
3131 }
3132 // </editor-fold>
3133
3134 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site">
3135 class MembersClosureCache extends SimpleVisitor<Scope.CompoundScope, Void> {
3136
3137 private Map<TypeSymbol, CompoundScope> _map = new HashMap<>();
3138
3139 Set<TypeSymbol> seenTypes = new HashSet<>();
3140
3141 class MembersScope extends CompoundScope {
3142
3143 CompoundScope scope;
3144
3145 public MembersScope(CompoundScope scope) {
3146 super(scope.owner);
3147 this.scope = scope;
3148 }
3149
3150 Predicate<Symbol> combine(Predicate<Symbol> sf) {
3151 return s -> !s.owner.isInterface() && (sf == null || sf.test(s));
3152 }
3153
3154 @Override
3155 public Iterable<Symbol> getSymbols(Predicate<Symbol> sf, LookupKind lookupKind) {
3156 return scope.getSymbols(combine(sf), lookupKind);
3157 }
3158
3159 @Override
3160 public Iterable<Symbol> getSymbolsByName(Name name, Predicate<Symbol> sf, LookupKind lookupKind) {
3161 return scope.getSymbolsByName(name, combine(sf), lookupKind);
3162 }
3163
3164 @Override
3165 public int getMark() {
3166 return scope.getMark();
3167 }
3168 }
3169
3170 CompoundScope nilScope;
3171
3172 /** members closure visitor methods **/
3173
3174 public CompoundScope visitType(Type t, Void _unused) {
3175 if (nilScope == null) {
3176 nilScope = new CompoundScope(syms.noSymbol);
3177 }
3178 return nilScope;
3179 }
3180
3181 @Override
3182 public CompoundScope visitClassType(ClassType t, Void _unused) {
3183 if (!seenTypes.add(t.tsym)) {
3184 //this is possible when an interface is implemented in multiple
3185 //superclasses, or when a class hierarchy is circular - in such
3186 //cases we don't need to recurse (empty scope is returned)
3187 return new CompoundScope(t.tsym);
3188 }
3189 try {
3190 seenTypes.add(t.tsym);
3191 ClassSymbol csym = (ClassSymbol)t.tsym;
3192 CompoundScope membersClosure = _map.get(csym);
3193 if (membersClosure == null) {
3194 membersClosure = new CompoundScope(csym);
3195 for (Type i : interfaces(t)) {
3196 membersClosure.prependSubScope(visit(i, null));
3197 }
3198 membersClosure.prependSubScope(visit(supertype(t), null));
3199 membersClosure.prependSubScope(csym.members());
3200 _map.put(csym, membersClosure);
3201 }
3202 return membersClosure;
3203 }
3204 finally {
3205 seenTypes.remove(t.tsym);
3206 }
3207 }
3208
3209 @Override
3210 public CompoundScope visitTypeVar(TypeVar t, Void _unused) {
3211 return visit(t.getUpperBound(), null);
3212 }
3213 }
3214
3215 private MembersClosureCache membersCache = new MembersClosureCache();
3216
3217 public CompoundScope membersClosure(Type site, boolean skipInterface) {
3218 CompoundScope cs = membersCache.visit(site, null);
3219 Assert.checkNonNull(cs, () -> "type " + site);
3220 return skipInterface ? membersCache.new MembersScope(cs) : cs;
3221 }
3222 // </editor-fold>
3223
3224
3225 /** Return first abstract member of class `sym'.
3226 */
3227 public MethodSymbol firstUnimplementedAbstract(ClassSymbol sym) {
3228 try {
3229 return firstUnimplementedAbstractImpl(sym, sym);
3230 } catch (CompletionFailure ex) {
3231 chk.completionError(enter.getEnv(sym).tree.pos(), ex);
3232 return null;
3233 }
3234 }
3235 //where:
3236 private MethodSymbol firstUnimplementedAbstractImpl(ClassSymbol impl, ClassSymbol c) {
3237 MethodSymbol undef = null;
3238 // Do not bother to search in classes that are not abstract,
3239 // since they cannot have abstract members.
3240 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
3241 Scope s = c.members();
3242 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) {
3243 if (sym.kind == MTH &&
3244 (sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
3245 MethodSymbol absmeth = (MethodSymbol)sym;
3246 MethodSymbol implmeth = absmeth.implementation(impl, this, true);
3247 if (implmeth == null || implmeth == absmeth) {
3248 //look for default implementations
3249 MethodSymbol prov = interfaceCandidates(impl.type, absmeth).head;
3250 if (prov != null && prov.overrides(absmeth, impl, this, true)) {
3251 implmeth = prov;
3252 }
3253 }
3254 if (implmeth == null || implmeth == absmeth) {
3255 undef = absmeth;
3256 break;
3257 }
3258 }
3259 }
3260 if (undef == null) {
3261 Type st = supertype(c.type);
3262 if (st.hasTag(CLASS))
3263 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)st.tsym);
3264 }
3265 for (List<Type> l = interfaces(c.type);
3266 undef == null && l.nonEmpty();
3267 l = l.tail) {
3268 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)l.head.tsym);
3269 }
3270 }
3271 return undef;
3272 }
3273
3274 public class CandidatesCache {
3275 public Map<Entry, List<MethodSymbol>> cache = new WeakHashMap<>();
3276
3277 class Entry {
3278 Type site;
3279 MethodSymbol msym;
3280
3281 Entry(Type site, MethodSymbol msym) {
3282 this.site = site;
3283 this.msym = msym;
3284 }
3285
3286 @Override
3287 public boolean equals(Object obj) {
3288 return (obj instanceof Entry entry)
3289 && entry.msym == msym
3290 && isSameType(site, entry.site);
3291 }
3292
3293 @Override
3294 public int hashCode() {
3295 return Types.this.hashCode(site) & ~msym.hashCode();
3296 }
3297 }
3298
3299 public List<MethodSymbol> get(Entry e) {
3300 return cache.get(e);
3301 }
3302
3303 public void put(Entry e, List<MethodSymbol> msymbols) {
3304 cache.put(e, msymbols);
3305 }
3306 }
3307
3308 public CandidatesCache candidatesCache = new CandidatesCache();
3309
3310 //where
3311 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) {
3312 CandidatesCache.Entry e = candidatesCache.new Entry(site, ms);
3313 List<MethodSymbol> candidates = candidatesCache.get(e);
3314 if (candidates == null) {
3315 Predicate<Symbol> filter = new MethodFilter(ms, site);
3316 List<MethodSymbol> candidates2 = List.nil();
3317 for (Symbol s : membersClosure(site, false).getSymbols(filter)) {
3318 if (!site.tsym.isInterface() && !s.owner.isInterface()) {
3319 return List.of((MethodSymbol)s);
3320 } else if (!candidates2.contains(s)) {
3321 candidates2 = candidates2.prepend((MethodSymbol)s);
3322 }
3323 }
3324 candidates = prune(candidates2);
3325 candidatesCache.put(e, candidates);
3326 }
3327 return candidates;
3328 }
3329
3330 public List<MethodSymbol> prune(List<MethodSymbol> methods) {
3331 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>();
3332 for (MethodSymbol m1 : methods) {
3333 boolean isMin_m1 = true;
3334 for (MethodSymbol m2 : methods) {
3335 if (m1 == m2) continue;
3336 if (m2.owner != m1.owner &&
3337 asSuper(m2.owner.type, m1.owner) != null) {
3338 isMin_m1 = false;
3339 break;
3340 }
3341 }
3342 if (isMin_m1)
3343 methodsMin.append(m1);
3344 }
3345 return methodsMin.toList();
3346 }
3347 // where
3348 private class MethodFilter implements Predicate<Symbol> {
3349
3350 Symbol msym;
3351 Type site;
3352
3353 MethodFilter(Symbol msym, Type site) {
3354 this.msym = msym;
3355 this.site = site;
3356 }
3357
3358 @Override
3359 public boolean test(Symbol s) {
3360 return s.kind == MTH &&
3361 s.name == msym.name &&
3362 (s.flags() & SYNTHETIC) == 0 &&
3363 s.isInheritedIn(site.tsym, Types.this) &&
3364 overrideEquivalent(memberType(site, s), memberType(site, msym));
3365 }
3366 }
3367 // </editor-fold>
3368
3369 /**
3370 * Does t have the same arguments as s? It is assumed that both
3371 * types are (possibly polymorphic) method types. Monomorphic
3372 * method types "have the same arguments", if their argument lists
3373 * are equal. Polymorphic method types "have the same arguments",
3374 * if they have the same arguments after renaming all type
3375 * variables of one to corresponding type variables in the other,
3376 * where correspondence is by position in the type parameter list.
3377 */
3378 public boolean hasSameArgs(Type t, Type s) {
3379 return hasSameArgs(t, s, true);
3380 }
3381
3382 public boolean hasSameArgs(Type t, Type s, boolean strict) {
3383 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict);
3384 }
3385
3386 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) {
3387 return hasSameArgs.visit(t, s);
3388 }
3389 // where
3390 private class HasSameArgs extends TypeRelation {
3391
3392 boolean strict;
3393
3394 public HasSameArgs(boolean strict) {
3395 this.strict = strict;
3396 }
3397
3398 public Boolean visitType(Type t, Type s) {
3399 throw new AssertionError();
3400 }
3401
3402 @Override
3403 public Boolean visitMethodType(MethodType t, Type s) {
3404 return s.hasTag(METHOD)
3405 && containsTypeEquivalent(t.argtypes, s.getParameterTypes());
3406 }
3407
3408 @Override
3409 public Boolean visitForAll(ForAll t, Type s) {
3410 if (!s.hasTag(FORALL))
3411 return strict ? false : visitMethodType(t.asMethodType(), s);
3412
3413 ForAll forAll = (ForAll)s;
3414 return hasSameBounds(t, forAll)
3415 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
3416 }
3417
3418 @Override
3419 public Boolean visitErrorType(ErrorType t, Type s) {
3420 return false;
3421 }
3422 }
3423
3424 TypeRelation hasSameArgs_strict = new HasSameArgs(true);
3425 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false);
3426
3427 // </editor-fold>
3428
3429 // <editor-fold defaultstate="collapsed" desc="subst">
3430 public List<Type> subst(List<Type> ts,
3431 List<Type> from,
3432 List<Type> to) {
3433 return ts.map(new Subst(from, to));
3434 }
3435
3436 /**
3437 * Substitute all occurrences of a type in `from' with the
3438 * corresponding type in `to' in 't'. Match lists `from' and `to'
3439 * from the right: If lists have different length, discard leading
3440 * elements of the longer list.
3441 */
3442 public Type subst(Type t, List<Type> from, List<Type> to) {
3443 return t.map(new Subst(from, to));
3444 }
3445
3446 private class Subst extends StructuralTypeMapping<Void> {
3447 List<Type> from;
3448 List<Type> to;
3449
3450 public Subst(List<Type> from, List<Type> to) {
3451 int fromLength = from.length();
3452 int toLength = to.length();
3453 while (fromLength > toLength) {
3454 fromLength--;
3455 from = from.tail;
3456 }
3457 while (fromLength < toLength) {
3458 toLength--;
3459 to = to.tail;
3460 }
3461 this.from = from;
3462 this.to = to;
3463 }
3464
3465 @Override
3466 public Type visitTypeVar(TypeVar t, Void ignored) {
3467 for (List<Type> from = this.from, to = this.to;
3468 from.nonEmpty();
3469 from = from.tail, to = to.tail) {
3470 if (t.equalsIgnoreMetadata(from.head)) {
3471 return to.head.withTypeVar(t);
3472 }
3473 }
3474 return t;
3475 }
3476
3477 @Override
3478 public Type visitClassType(ClassType t, Void ignored) {
3479 if (!t.isCompound()) {
3480 return super.visitClassType(t, ignored);
3481 } else {
3482 Type st = visit(supertype(t));
3483 List<Type> is = visit(interfaces(t), ignored);
3484 if (st == supertype(t) && is == interfaces(t))
3485 return t;
3486 else
3487 return makeIntersectionType(is.prepend(st));
3488 }
3489 }
3490
3491 @Override
3492 public Type visitWildcardType(WildcardType t, Void ignored) {
3493 WildcardType t2 = (WildcardType)super.visitWildcardType(t, ignored);
3494 if (t2 != t && t.isExtendsBound() && t2.type.isExtendsBound()) {
3495 t2.type = wildUpperBound(t2.type);
3496 }
3497 return t2;
3498 }
3499
3500 @Override
3501 public Type visitForAll(ForAll t, Void ignored) {
3502 if (Type.containsAny(to, t.tvars)) {
3503 //perform alpha-renaming of free-variables in 't'
3504 //if 'to' types contain variables that are free in 't'
3505 List<Type> freevars = newInstances(t.tvars);
3506 t = new ForAll(freevars,
3507 Types.this.subst(t.qtype, t.tvars, freevars));
3508 }
3509 List<Type> tvars1 = substBounds(t.tvars, from, to);
3510 Type qtype1 = visit(t.qtype);
3511 if (tvars1 == t.tvars && qtype1 == t.qtype) {
3512 return t;
3513 } else if (tvars1 == t.tvars) {
3514 return new ForAll(tvars1, qtype1) {
3515 @Override
3516 public boolean needsStripping() {
3517 return true;
3518 }
3519 };
3520 } else {
3521 return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1)) {
3522 @Override
3523 public boolean needsStripping() {
3524 return true;
3525 }
3526 };
3527 }
3528 }
3529 }
3530
3531 public List<Type> substBounds(List<Type> tvars,
3532 List<Type> from,
3533 List<Type> to) {
3534 if (tvars.isEmpty())
3535 return tvars;
3536 ListBuffer<Type> newBoundsBuf = new ListBuffer<>();
3537 boolean changed = false;
3538 // calculate new bounds
3539 for (Type t : tvars) {
3540 TypeVar tv = (TypeVar) t;
3541 Type bound = subst(tv.getUpperBound(), from, to);
3542 if (bound != tv.getUpperBound())
3543 changed = true;
3544 newBoundsBuf.append(bound);
3545 }
3546 if (!changed)
3547 return tvars;
3548 ListBuffer<Type> newTvars = new ListBuffer<>();
3549 // create new type variables without bounds
3550 for (Type t : tvars) {
3551 newTvars.append(new TypeVar(t.tsym, null, syms.botType,
3552 t.getMetadata()));
3553 }
3554 // the new bounds should use the new type variables in place
3555 // of the old
3556 List<Type> newBounds = newBoundsBuf.toList();
3557 from = tvars;
3558 to = newTvars.toList();
3559 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) {
3560 newBounds.head = subst(newBounds.head, from, to);
3561 }
3562 newBounds = newBoundsBuf.toList();
3563 // set the bounds of new type variables to the new bounds
3564 for (Type t : newTvars.toList()) {
3565 TypeVar tv = (TypeVar) t;
3566 tv.setUpperBound( newBounds.head );
3567 newBounds = newBounds.tail;
3568 }
3569 return newTvars.toList();
3570 }
3571
3572 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) {
3573 Type bound1 = subst(t.getUpperBound(), from, to);
3574 if (bound1 == t.getUpperBound())
3575 return t;
3576 else {
3577 // create new type variable without bounds
3578 TypeVar tv = new TypeVar(t.tsym, null, syms.botType,
3579 t.getMetadata());
3580 // the new bound should use the new type variable in place
3581 // of the old
3582 tv.setUpperBound( subst(bound1, List.of(t), List.of(tv)) );
3583 return tv;
3584 }
3585 }
3586 // </editor-fold>
3587
3588 // <editor-fold defaultstate="collapsed" desc="hasSameBounds">
3589 /**
3590 * Does t have the same bounds for quantified variables as s?
3591 */
3592 public boolean hasSameBounds(ForAll t, ForAll s) {
3593 List<Type> l1 = t.tvars;
3594 List<Type> l2 = s.tvars;
3595 while (l1.nonEmpty() && l2.nonEmpty() &&
3596 isSameType(l1.head.getUpperBound(),
3597 subst(l2.head.getUpperBound(),
3598 s.tvars,
3599 t.tvars))) {
3600 l1 = l1.tail;
3601 l2 = l2.tail;
3602 }
3603 return l1.isEmpty() && l2.isEmpty();
3604 }
3605 // </editor-fold>
3606
3607 // <editor-fold defaultstate="collapsed" desc="newInstances">
3608 /** Create new vector of type variables from list of variables
3609 * changing all recursive bounds from old to new list.
3610 */
3611 public List<Type> newInstances(List<Type> tvars) {
3612 List<Type> tvars1 = tvars.map(newInstanceFun);
3613 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) {
3614 TypeVar tv = (TypeVar) l.head;
3615 tv.setUpperBound( subst(tv.getUpperBound(), tvars, tvars1) );
3616 }
3617 return tvars1;
3618 }
3619 private static final TypeMapping<Void> newInstanceFun = new TypeMapping<Void>() {
3620 @Override
3621 public TypeVar visitTypeVar(TypeVar t, Void _unused) {
3622 return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound(), t.getMetadata());
3623 }
3624 };
3625 // </editor-fold>
3626
3627 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) {
3628 return original.accept(methodWithParameters, newParams);
3629 }
3630 // where
3631 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() {
3632 public Type visitType(Type t, List<Type> newParams) {
3633 throw new IllegalArgumentException("Not a method type: " + t);
3634 }
3635 public Type visitMethodType(MethodType t, List<Type> newParams) {
3636 return new MethodType(newParams, t.restype, t.thrown, t.tsym);
3637 }
3638 public Type visitForAll(ForAll t, List<Type> newParams) {
3639 return new ForAll(t.tvars, t.qtype.accept(this, newParams));
3640 }
3641 };
3642
3643 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) {
3644 return original.accept(methodWithThrown, newThrown);
3645 }
3646 // where
3647 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() {
3648 public Type visitType(Type t, List<Type> newThrown) {
3649 throw new IllegalArgumentException("Not a method type: " + t);
3650 }
3651 public Type visitMethodType(MethodType t, List<Type> newThrown) {
3652 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym);
3653 }
3654 public Type visitForAll(ForAll t, List<Type> newThrown) {
3655 return new ForAll(t.tvars, t.qtype.accept(this, newThrown));
3656 }
3657 };
3658
3659 public Type createMethodTypeWithReturn(Type original, Type newReturn) {
3660 return original.accept(methodWithReturn, newReturn);
3661 }
3662 // where
3663 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() {
3664 public Type visitType(Type t, Type newReturn) {
3665 throw new IllegalArgumentException("Not a method type: " + t);
3666 }
3667 public Type visitMethodType(MethodType t, Type newReturn) {
3668 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym) {
3669 @Override
3670 public Type baseType() {
3671 return t;
3672 }
3673 };
3674 }
3675 public Type visitForAll(ForAll t, Type newReturn) {
3676 return new ForAll(t.tvars, t.qtype.accept(this, newReturn)) {
3677 @Override
3678 public Type baseType() {
3679 return t;
3680 }
3681 };
3682 }
3683 };
3684
3685 // <editor-fold defaultstate="collapsed" desc="createErrorType">
3686 public Type createErrorType(Type originalType) {
3687 return new ErrorType(originalType, syms.errSymbol);
3688 }
3689
3690 public Type createErrorType(ClassSymbol c, Type originalType) {
3691 return new ErrorType(c, originalType);
3692 }
3693
3694 public Type createErrorType(Name name, TypeSymbol container, Type originalType) {
3695 return new ErrorType(name, container, originalType);
3696 }
3697 // </editor-fold>
3698
3699 // <editor-fold defaultstate="collapsed" desc="rank">
3700 /**
3701 * The rank of a class is the length of the longest path between
3702 * the class and java.lang.Object in the class inheritance
3703 * graph. Undefined for all but reference types.
3704 */
3705 public int rank(Type t) {
3706 switch(t.getTag()) {
3707 case CLASS: {
3708 ClassType cls = (ClassType)t;
3709 if (cls.rank_field < 0) {
3710 Name fullname = cls.tsym.getQualifiedName();
3711 if (fullname == names.java_lang_Object)
3712 cls.rank_field = 0;
3713 else {
3714 int r = rank(supertype(cls));
3715 for (List<Type> l = interfaces(cls);
3716 l.nonEmpty();
3717 l = l.tail) {
3718 if (rank(l.head) > r)
3719 r = rank(l.head);
3720 }
3721 cls.rank_field = r + 1;
3722 }
3723 }
3724 return cls.rank_field;
3725 }
3726 case TYPEVAR: {
3727 TypeVar tvar = (TypeVar)t;
3728 if (tvar.rank_field < 0) {
3729 int r = rank(supertype(tvar));
3730 for (List<Type> l = interfaces(tvar);
3731 l.nonEmpty();
3732 l = l.tail) {
3733 if (rank(l.head) > r) r = rank(l.head);
3734 }
3735 tvar.rank_field = r + 1;
3736 }
3737 return tvar.rank_field;
3738 }
3739 case ERROR:
3740 case NONE:
3741 return 0;
3742 default:
3743 throw new AssertionError();
3744 }
3745 }
3746 // </editor-fold>
3747
3748 /**
3749 * Helper method for generating a string representation of a given type
3750 * accordingly to a given locale
3751 */
3752 public String toString(Type t, Locale locale) {
3753 return Printer.createStandardPrinter(messages).visit(t, locale);
3754 }
3755
3756 /**
3757 * Helper method for generating a string representation of a given type
3758 * accordingly to a given locale
3759 */
3760 public String toString(Symbol t, Locale locale) {
3761 return Printer.createStandardPrinter(messages).visit(t, locale);
3762 }
3763
3764 // <editor-fold defaultstate="collapsed" desc="toString">
3765 /**
3766 * This toString is slightly more descriptive than the one on Type.
3767 *
3768 * @deprecated Types.toString(Type t, Locale l) provides better support
3769 * for localization
3770 */
3771 @Deprecated
3772 public String toString(Type t) {
3773 if (t.hasTag(FORALL)) {
3774 ForAll forAll = (ForAll)t;
3775 return typaramsString(forAll.tvars) + forAll.qtype;
3776 }
3777 return "" + t;
3778 }
3779 // where
3780 private String typaramsString(List<Type> tvars) {
3781 StringBuilder s = new StringBuilder();
3782 s.append('<');
3783 boolean first = true;
3784 for (Type t : tvars) {
3785 if (!first) s.append(", ");
3786 first = false;
3787 appendTyparamString(((TypeVar)t), s);
3788 }
3789 s.append('>');
3790 return s.toString();
3791 }
3792 private void appendTyparamString(TypeVar t, StringBuilder buf) {
3793 buf.append(t);
3794 if (t.getUpperBound() == null ||
3795 t.getUpperBound().tsym.getQualifiedName() == names.java_lang_Object)
3796 return;
3797 buf.append(" extends "); // Java syntax; no need for i18n
3798 Type bound = t.getUpperBound();
3799 if (!bound.isCompound()) {
3800 buf.append(bound);
3801 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) {
3802 buf.append(supertype(t));
3803 for (Type intf : interfaces(t)) {
3804 buf.append('&');
3805 buf.append(intf);
3806 }
3807 } else {
3808 // No superclass was given in bounds.
3809 // In this case, supertype is Object, erasure is first interface.
3810 boolean first = true;
3811 for (Type intf : interfaces(t)) {
3812 if (!first) buf.append('&');
3813 first = false;
3814 buf.append(intf);
3815 }
3816 }
3817 }
3818 // </editor-fold>
3819
3820 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types">
3821 /**
3822 * A cache for closures.
3823 *
3824 * <p>A closure is a list of all the supertypes and interfaces of
3825 * a class or interface type, ordered by ClassSymbol.precedes
3826 * (that is, subclasses come first, arbitrarily but fixed
3827 * otherwise).
3828 */
3829 private Map<Type,List<Type>> closureCache = new HashMap<>();
3830
3831 /**
3832 * Returns the closure of a class or interface type.
3833 */
3834 public List<Type> closure(Type t) {
3835 List<Type> cl = closureCache.get(t);
3836 if (cl == null) {
3837 Type st = supertype(t);
3838 if (!t.isCompound()) {
3839 if (st.hasTag(CLASS)) {
3840 cl = insert(closure(st), t);
3841 } else if (st.hasTag(TYPEVAR)) {
3842 cl = closure(st).prepend(t);
3843 } else {
3844 cl = List.of(t);
3845 }
3846 } else {
3847 cl = closure(supertype(t));
3848 }
3849 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail)
3850 cl = union(cl, closure(l.head));
3851 closureCache.put(t, cl);
3852 }
3853 return cl;
3854 }
3855
3856 /**
3857 * Collect types into a new closure (using a {@code ClosureHolder})
3858 */
3859 public Collector<Type, ClosureHolder, List<Type>> closureCollector(boolean minClosure, BiPredicate<Type, Type> shouldSkip) {
3860 return Collector.of(() -> new ClosureHolder(minClosure, shouldSkip),
3861 ClosureHolder::add,
3862 ClosureHolder::merge,
3863 ClosureHolder::closure);
3864 }
3865 //where
3866 class ClosureHolder {
3867 List<Type> closure;
3868 final boolean minClosure;
3869 final BiPredicate<Type, Type> shouldSkip;
3870
3871 ClosureHolder(boolean minClosure, BiPredicate<Type, Type> shouldSkip) {
3872 this.closure = List.nil();
3873 this.minClosure = minClosure;
3874 this.shouldSkip = shouldSkip;
3875 }
3876
3877 void add(Type type) {
3878 closure = insert(closure, type, shouldSkip);
3879 }
3880
3881 ClosureHolder merge(ClosureHolder other) {
3882 closure = union(closure, other.closure, shouldSkip);
3883 return this;
3884 }
3885
3886 List<Type> closure() {
3887 return minClosure ? closureMin(closure) : closure;
3888 }
3889 }
3890
3891 BiPredicate<Type, Type> basicClosureSkip = (t1, t2) -> t1.tsym == t2.tsym;
3892
3893 /**
3894 * Insert a type in a closure
3895 */
3896 public List<Type> insert(List<Type> cl, Type t, BiPredicate<Type, Type> shouldSkip) {
3897 if (cl.isEmpty()) {
3898 return cl.prepend(t);
3899 } else if (shouldSkip.test(t, cl.head)) {
3900 return cl;
3901 } else if (t.tsym.precedes(cl.head.tsym, this)) {
3902 return cl.prepend(t);
3903 } else {
3904 // t comes after head, or the two are unrelated
3905 return insert(cl.tail, t, shouldSkip).prepend(cl.head);
3906 }
3907 }
3908
3909 public List<Type> insert(List<Type> cl, Type t) {
3910 return insert(cl, t, basicClosureSkip);
3911 }
3912
3913 /**
3914 * Form the union of two closures
3915 */
3916 public List<Type> union(List<Type> cl1, List<Type> cl2, BiPredicate<Type, Type> shouldSkip) {
3917 if (cl1.isEmpty()) {
3918 return cl2;
3919 } else if (cl2.isEmpty()) {
3920 return cl1;
3921 } else if (shouldSkip.test(cl1.head, cl2.head)) {
3922 return union(cl1.tail, cl2.tail, shouldSkip).prepend(cl1.head);
3923 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) {
3924 return union(cl1, cl2.tail, shouldSkip).prepend(cl2.head);
3925 } else {
3926 return union(cl1.tail, cl2, shouldSkip).prepend(cl1.head);
3927 }
3928 }
3929
3930 public List<Type> union(List<Type> cl1, List<Type> cl2) {
3931 return union(cl1, cl2, basicClosureSkip);
3932 }
3933
3934 /**
3935 * Intersect two closures
3936 */
3937 public List<Type> intersect(List<Type> cl1, List<Type> cl2) {
3938 if (cl1 == cl2)
3939 return cl1;
3940 if (cl1.isEmpty() || cl2.isEmpty())
3941 return List.nil();
3942 if (cl1.head.tsym.precedes(cl2.head.tsym, this))
3943 return intersect(cl1.tail, cl2);
3944 if (cl2.head.tsym.precedes(cl1.head.tsym, this))
3945 return intersect(cl1, cl2.tail);
3946 if (isSameType(cl1.head, cl2.head))
3947 return intersect(cl1.tail, cl2.tail).prepend(cl1.head);
3948 if (cl1.head.tsym == cl2.head.tsym &&
3949 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) {
3950 if (cl1.head.isParameterized() && cl2.head.isParameterized()) {
3951 Type merge = merge(cl1.head,cl2.head);
3952 return intersect(cl1.tail, cl2.tail).prepend(merge);
3953 }
3954 if (cl1.head.isRaw() || cl2.head.isRaw())
3955 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head));
3956 }
3957 return intersect(cl1.tail, cl2.tail);
3958 }
3959 // where
3960 class TypePair {
3961 final Type t1;
3962 final Type t2;;
3963
3964 TypePair(Type t1, Type t2) {
3965 this.t1 = t1;
3966 this.t2 = t2;
3967 }
3968 @Override
3969 public int hashCode() {
3970 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2);
3971 }
3972 @Override
3973 public boolean equals(Object obj) {
3974 return (obj instanceof TypePair typePair)
3975 && isSameType(t1, typePair.t1)
3976 && isSameType(t2, typePair.t2);
3977 }
3978 }
3979 Set<TypePair> mergeCache = new HashSet<>();
3980 private Type merge(Type c1, Type c2) {
3981 ClassType class1 = (ClassType) c1;
3982 List<Type> act1 = class1.getTypeArguments();
3983 ClassType class2 = (ClassType) c2;
3984 List<Type> act2 = class2.getTypeArguments();
3985 ListBuffer<Type> merged = new ListBuffer<>();
3986 List<Type> typarams = class1.tsym.type.getTypeArguments();
3987
3988 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) {
3989 if (containsType(act1.head, act2.head)) {
3990 merged.append(act1.head);
3991 } else if (containsType(act2.head, act1.head)) {
3992 merged.append(act2.head);
3993 } else {
3994 TypePair pair = new TypePair(c1, c2);
3995 Type m;
3996 if (mergeCache.add(pair)) {
3997 m = new WildcardType(lub(wildUpperBound(act1.head),
3998 wildUpperBound(act2.head)),
3999 BoundKind.EXTENDS,
4000 syms.boundClass);
4001 mergeCache.remove(pair);
4002 } else {
4003 m = new WildcardType(syms.objectType,
4004 BoundKind.UNBOUND,
4005 syms.boundClass);
4006 }
4007 merged.append(m.withTypeVar(typarams.head));
4008 }
4009 act1 = act1.tail;
4010 act2 = act2.tail;
4011 typarams = typarams.tail;
4012 }
4013 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty());
4014 // There is no spec detailing how type annotations are to
4015 // be inherited. So set it to noAnnotations for now
4016 return new ClassType(class1.getEnclosingType(), merged.toList(),
4017 class1.tsym, List.nil(), class1.getFlavor());
4018 }
4019
4020 /**
4021 * Return the minimum type of a closure, a compound type if no
4022 * unique minimum exists.
4023 */
4024 private Type compoundMin(List<Type> cl) {
4025 if (cl.isEmpty()) return syms.objectType;
4026 List<Type> compound = closureMin(cl);
4027 if (compound.isEmpty())
4028 return null;
4029 else if (compound.tail.isEmpty())
4030 return compound.head;
4031 else
4032 return makeIntersectionType(compound);
4033 }
4034
4035 /**
4036 * Return the minimum types of a closure, suitable for computing
4037 * compoundMin or glb.
4038 */
4039 private List<Type> closureMin(List<Type> cl) {
4040 ListBuffer<Type> classes = new ListBuffer<>();
4041 ListBuffer<Type> interfaces = new ListBuffer<>();
4042 Set<Type> toSkip = new HashSet<>();
4043 while (!cl.isEmpty()) {
4044 Type current = cl.head;
4045 boolean keep = !toSkip.contains(current);
4046 if (keep && current.hasTag(TYPEVAR)) {
4047 // skip lower-bounded variables with a subtype in cl.tail
4048 for (Type t : cl.tail) {
4049 if (isSubtypeNoCapture(t, current)) {
4050 keep = false;
4051 break;
4052 }
4053 }
4054 }
4055 if (keep) {
4056 if (current.isInterface())
4057 interfaces.append(current);
4058 else
4059 classes.append(current);
4060 for (Type t : cl.tail) {
4061 // skip supertypes of 'current' in cl.tail
4062 if (isSubtypeNoCapture(current, t))
4063 toSkip.add(t);
4064 }
4065 }
4066 cl = cl.tail;
4067 }
4068 return classes.appendList(interfaces).toList();
4069 }
4070
4071 /**
4072 * Return the least upper bound of list of types. if the lub does
4073 * not exist return null.
4074 */
4075 public Type lub(List<Type> ts) {
4076 return lub(ts.toArray(new Type[ts.length()]));
4077 }
4078
4079 /**
4080 * Return the least upper bound (lub) of set of types. If the lub
4081 * does not exist return the type of null (bottom).
4082 */
4083 public Type lub(Type... ts) {
4084 final int UNKNOWN_BOUND = 0;
4085 final int ARRAY_BOUND = 1;
4086 final int CLASS_BOUND = 2;
4087
4088 int[] kinds = new int[ts.length];
4089
4090 int boundkind = UNKNOWN_BOUND;
4091 for (int i = 0 ; i < ts.length ; i++) {
4092 Type t = ts[i];
4093 switch (t.getTag()) {
4094 case CLASS:
4095 boundkind |= kinds[i] = CLASS_BOUND;
4096 break;
4097 case ARRAY:
4098 boundkind |= kinds[i] = ARRAY_BOUND;
4099 break;
4100 case TYPEVAR:
4101 do {
4102 t = t.getUpperBound();
4103 } while (t.hasTag(TYPEVAR));
4104 if (t.hasTag(ARRAY)) {
4105 boundkind |= kinds[i] = ARRAY_BOUND;
4106 } else {
4107 boundkind |= kinds[i] = CLASS_BOUND;
4108 }
4109 break;
4110 default:
4111 kinds[i] = UNKNOWN_BOUND;
4112 if (t.isPrimitive())
4113 return syms.errType;
4114 }
4115 }
4116 switch (boundkind) {
4117 case 0:
4118 return syms.botType;
4119
4120 case ARRAY_BOUND:
4121 // calculate lub(A[], B[])
4122 Type[] elements = new Type[ts.length];
4123 for (int i = 0 ; i < ts.length ; i++) {
4124 Type elem = elements[i] = elemTypeFun.apply(ts[i]);
4125 if (elem.isPrimitive()) {
4126 // if a primitive type is found, then return
4127 // arraySuperType unless all the types are the
4128 // same
4129 Type first = ts[0];
4130 for (int j = 1 ; j < ts.length ; j++) {
4131 if (!isSameType(first, ts[j])) {
4132 // lub(int[], B[]) is Cloneable & Serializable
4133 return arraySuperType();
4134 }
4135 }
4136 // all the array types are the same, return one
4137 // lub(int[], int[]) is int[]
4138 return first;
4139 }
4140 }
4141 // lub(A[], B[]) is lub(A, B)[]
4142 return new ArrayType(lub(elements), syms.arrayClass);
4143
4144 case CLASS_BOUND:
4145 // calculate lub(A, B)
4146 int startIdx = 0;
4147 for (int i = 0; i < ts.length ; i++) {
4148 Type t = ts[i];
4149 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) {
4150 break;
4151 } else {
4152 startIdx++;
4153 }
4154 }
4155 Assert.check(startIdx < ts.length);
4156 //step 1 - compute erased candidate set (EC)
4157 List<Type> cl = erasedSupertypes(ts[startIdx]);
4158 for (int i = startIdx + 1 ; i < ts.length ; i++) {
4159 Type t = ts[i];
4160 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR))
4161 cl = intersect(cl, erasedSupertypes(t));
4162 }
4163 //step 2 - compute minimal erased candidate set (MEC)
4164 List<Type> mec = closureMin(cl);
4165 //step 3 - for each element G in MEC, compute lci(Inv(G))
4166 List<Type> candidates = List.nil();
4167 for (Type erasedSupertype : mec) {
4168 List<Type> lci = List.of(asSuper(ts[startIdx], erasedSupertype.tsym));
4169 for (int i = startIdx + 1 ; i < ts.length ; i++) {
4170 Type superType = asSuper(ts[i], erasedSupertype.tsym);
4171 lci = intersect(lci, superType != null ? List.of(superType) : List.nil());
4172 }
4173 candidates = candidates.appendList(lci);
4174 }
4175 //step 4 - let MEC be { G1, G2 ... Gn }, then we have that
4176 //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn))
4177 return compoundMin(candidates);
4178
4179 default:
4180 // calculate lub(A, B[])
4181 List<Type> classes = List.of(arraySuperType());
4182 for (int i = 0 ; i < ts.length ; i++) {
4183 if (kinds[i] != ARRAY_BOUND) // Filter out any arrays
4184 classes = classes.prepend(ts[i]);
4185 }
4186 // lub(A, B[]) is lub(A, arraySuperType)
4187 return lub(classes);
4188 }
4189 }
4190 // where
4191 List<Type> erasedSupertypes(Type t) {
4192 ListBuffer<Type> buf = new ListBuffer<>();
4193 for (Type sup : closure(t)) {
4194 if (sup.hasTag(TYPEVAR)) {
4195 buf.append(sup);
4196 } else {
4197 buf.append(erasure(sup));
4198 }
4199 }
4200 return buf.toList();
4201 }
4202
4203 private Type arraySuperType;
4204 private Type arraySuperType() {
4205 // initialized lazily to avoid problems during compiler startup
4206 if (arraySuperType == null) {
4207 // JLS 10.8: all arrays implement Cloneable and Serializable.
4208 arraySuperType = makeIntersectionType(List.of(syms.serializableType,
4209 syms.cloneableType), true);
4210 }
4211 return arraySuperType;
4212 }
4213 // </editor-fold>
4214
4215 // <editor-fold defaultstate="collapsed" desc="Greatest lower bound">
4216 public Type glb(List<Type> ts) {
4217 Type t1 = ts.head;
4218 for (Type t2 : ts.tail) {
4219 if (t1.isErroneous())
4220 return t1;
4221 t1 = glb(t1, t2);
4222 }
4223 return t1;
4224 }
4225 //where
4226 public Type glb(Type t, Type s) {
4227 if (s == null)
4228 return t;
4229 else if (t.isPrimitive() || s.isPrimitive())
4230 return syms.errType;
4231 else if (isSubtypeNoCapture(t, s))
4232 return t;
4233 else if (isSubtypeNoCapture(s, t))
4234 return s;
4235
4236 List<Type> closure = union(closure(t), closure(s));
4237 return glbFlattened(closure, t);
4238 }
4239 //where
4240 /**
4241 * Perform glb for a list of non-primitive, non-error, non-compound types;
4242 * redundant elements are removed. Bounds should be ordered according to
4243 * {@link Symbol#precedes(TypeSymbol,Types)}.
4244 *
4245 * @param flatBounds List of type to glb
4246 * @param errT Original type to use if the result is an error type
4247 */
4248 private Type glbFlattened(List<Type> flatBounds, Type errT) {
4249 List<Type> bounds = closureMin(flatBounds);
4250
4251 if (bounds.isEmpty()) { // length == 0
4252 return syms.objectType;
4253 } else if (bounds.tail.isEmpty()) { // length == 1
4254 return bounds.head;
4255 } else { // length > 1
4256 int classCount = 0;
4257 List<Type> cvars = List.nil();
4258 List<Type> lowers = List.nil();
4259 for (Type bound : bounds) {
4260 if (!bound.isInterface()) {
4261 classCount++;
4262 Type lower = cvarLowerBound(bound);
4263 if (bound != lower && !lower.hasTag(BOT)) {
4264 cvars = cvars.append(bound);
4265 lowers = lowers.append(lower);
4266 }
4267 }
4268 }
4269 if (classCount > 1) {
4270 if (lowers.isEmpty()) {
4271 return createErrorType(errT);
4272 } else {
4273 // try again with lower bounds included instead of capture variables
4274 List<Type> newBounds = bounds.diff(cvars).appendList(lowers);
4275 return glb(newBounds);
4276 }
4277 }
4278 }
4279 return makeIntersectionType(bounds);
4280 }
4281 // </editor-fold>
4282
4283 // <editor-fold defaultstate="collapsed" desc="hashCode">
4284 /**
4285 * Compute a hash code on a type.
4286 */
4287 public int hashCode(Type t) {
4288 return hashCode(t, false);
4289 }
4290
4291 public int hashCode(Type t, boolean strict) {
4292 return strict ?
4293 hashCodeStrictVisitor.visit(t) :
4294 hashCodeVisitor.visit(t);
4295 }
4296 // where
4297 private static final HashCodeVisitor hashCodeVisitor = new HashCodeVisitor();
4298 private static final HashCodeVisitor hashCodeStrictVisitor = new HashCodeVisitor() {
4299 @Override
4300 public Integer visitTypeVar(TypeVar t, Void ignored) {
4301 return System.identityHashCode(t);
4302 }
4303 };
4304
4305 private static class HashCodeVisitor extends UnaryVisitor<Integer> {
4306 public Integer visitType(Type t, Void ignored) {
4307 return t.getTag().ordinal();
4308 }
4309
4310 @Override
4311 public Integer visitClassType(ClassType t, Void ignored) {
4312 int result = visit(t.getEnclosingType());
4313 result *= 127;
4314 result += t.tsym.flatName().hashCode();
4315 for (Type s : t.getTypeArguments()) {
4316 result *= 127;
4317 result += visit(s);
4318 }
4319 return result;
4320 }
4321
4322 @Override
4323 public Integer visitMethodType(MethodType t, Void ignored) {
4324 int h = METHOD.ordinal();
4325 for (List<Type> thisargs = t.argtypes;
4326 thisargs.tail != null;
4327 thisargs = thisargs.tail)
4328 h = (h << 5) + visit(thisargs.head);
4329 return (h << 5) + visit(t.restype);
4330 }
4331
4332 @Override
4333 public Integer visitWildcardType(WildcardType t, Void ignored) {
4334 int result = t.kind.hashCode();
4335 if (t.type != null) {
4336 result *= 127;
4337 result += visit(t.type);
4338 }
4339 return result;
4340 }
4341
4342 @Override
4343 public Integer visitArrayType(ArrayType t, Void ignored) {
4344 return visit(t.elemtype) + 12;
4345 }
4346
4347 @Override
4348 public Integer visitTypeVar(TypeVar t, Void ignored) {
4349 return System.identityHashCode(t);
4350 }
4351
4352 @Override
4353 public Integer visitUndetVar(UndetVar t, Void ignored) {
4354 return System.identityHashCode(t);
4355 }
4356
4357 @Override
4358 public Integer visitErrorType(ErrorType t, Void ignored) {
4359 return 0;
4360 }
4361 }
4362 // </editor-fold>
4363
4364 // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable">
4365 /**
4366 * Does t have a result that is a subtype of the result type of s,
4367 * suitable for covariant returns? It is assumed that both types
4368 * are (possibly polymorphic) method types. Monomorphic method
4369 * types are handled in the obvious way. Polymorphic method types
4370 * require renaming all type variables of one to corresponding
4371 * type variables in the other, where correspondence is by
4372 * position in the type parameter list. */
4373 public boolean resultSubtype(Type t, Type s, Warner warner) {
4374 List<Type> tvars = t.getTypeArguments();
4375 List<Type> svars = s.getTypeArguments();
4376 Type tres = t.getReturnType();
4377 Type sres = subst(s.getReturnType(), svars, tvars);
4378 return covariantReturnType(tres, sres, warner);
4379 }
4380
4381 /**
4382 * Return-Type-Substitutable.
4383 * @jls 8.4.5 Method Result
4384 */
4385 public boolean returnTypeSubstitutable(Type r1, Type r2) {
4386 if (hasSameArgs(r1, r2))
4387 return resultSubtype(r1, r2, noWarnings);
4388 else
4389 return covariantReturnType(r1.getReturnType(),
4390 erasure(r2.getReturnType()),
4391 noWarnings);
4392 }
4393
4394 public boolean returnTypeSubstitutable(Type r1,
4395 Type r2, Type r2res,
4396 Warner warner) {
4397 if (isSameType(r1.getReturnType(), r2res))
4398 return true;
4399 if (r1.getReturnType().isPrimitive() || r2res.isPrimitive())
4400 return false;
4401
4402 if (hasSameArgs(r1, r2))
4403 return covariantReturnType(r1.getReturnType(), r2res, warner);
4404 if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner))
4405 return true;
4406 if (!isSubtype(r1.getReturnType(), erasure(r2res)))
4407 return false;
4408 warner.warn(LintCategory.UNCHECKED);
4409 return true;
4410 }
4411
4412 /**
4413 * Is t an appropriate return type in an overrider for a
4414 * method that returns s?
4415 */
4416 public boolean covariantReturnType(Type t, Type s, Warner warner) {
4417 return
4418 isSameType(t, s) ||
4419 !t.isPrimitive() &&
4420 !s.isPrimitive() &&
4421 isAssignable(t, s, warner);
4422 }
4423 // </editor-fold>
4424
4425 // <editor-fold defaultstate="collapsed" desc="Box/unbox support">
4426 /**
4427 * Return the class that boxes the given primitive.
4428 */
4429 public ClassSymbol boxedClass(Type t) {
4430 return syms.enterClass(syms.java_base, syms.boxedName[t.getTag().ordinal()]);
4431 }
4432
4433 /**
4434 * Return the boxed type if 't' is primitive, otherwise return 't' itself.
4435 */
4436 public Type boxedTypeOrType(Type t) {
4437 return t.isPrimitive() ?
4438 boxedClass(t).type :
4439 t;
4440 }
4441
4442 /**
4443 * Return the primitive type corresponding to a boxed type.
4444 */
4445 public Type unboxedType(Type t) {
4446 if (t.hasTag(ERROR))
4447 return Type.noType;
4448 for (int i=0; i<syms.boxedName.length; i++) {
4449 Name box = syms.boxedName[i];
4450 if (box != null &&
4451 asSuper(t, syms.enterClass(syms.java_base, box)) != null)
4452 return syms.typeOfTag[i];
4453 }
4454 return Type.noType;
4455 }
4456
4457 /**
4458 * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself.
4459 */
4460 public Type unboxedTypeOrType(Type t) {
4461 Type unboxedType = unboxedType(t);
4462 return unboxedType.hasTag(NONE) ? t : unboxedType;
4463 }
4464 // </editor-fold>
4465
4466 // <editor-fold defaultstate="collapsed" desc="Capture conversion">
4467 /*
4468 * JLS 5.1.10 Capture Conversion:
4469 *
4470 * Let G name a generic type declaration with n formal type
4471 * parameters A1 ... An with corresponding bounds U1 ... Un. There
4472 * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>,
4473 * where, for 1 <= i <= n:
4474 *
4475 * + If Ti is a wildcard type argument (4.5.1) of the form ? then
4476 * Si is a fresh type variable whose upper bound is
4477 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null
4478 * type.
4479 *
4480 * + If Ti is a wildcard type argument of the form ? extends Bi,
4481 * then Si is a fresh type variable whose upper bound is
4482 * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is
4483 * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is
4484 * a compile-time error if for any two classes (not interfaces)
4485 * Vi and Vj,Vi is not a subclass of Vj or vice versa.
4486 *
4487 * + If Ti is a wildcard type argument of the form ? super Bi,
4488 * then Si is a fresh type variable whose upper bound is
4489 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi.
4490 *
4491 * + Otherwise, Si = Ti.
4492 *
4493 * Capture conversion on any type other than a parameterized type
4494 * (4.5) acts as an identity conversion (5.1.1). Capture
4495 * conversions never require a special action at run time and
4496 * therefore never throw an exception at run time.
4497 *
4498 * Capture conversion is not applied recursively.
4499 */
4500 /**
4501 * Capture conversion as specified by the JLS.
4502 */
4503
4504 public List<Type> capture(List<Type> ts) {
4505 List<Type> buf = List.nil();
4506 for (Type t : ts) {
4507 buf = buf.prepend(capture(t));
4508 }
4509 return buf.reverse();
4510 }
4511
4512 public Type capture(Type t) {
4513 if (!t.hasTag(CLASS)) {
4514 return t;
4515 }
4516 if (t.getEnclosingType() != Type.noType) {
4517 Type capturedEncl = capture(t.getEnclosingType());
4518 if (capturedEncl != t.getEnclosingType()) {
4519 Type type1 = memberType(capturedEncl, t.tsym);
4520 t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments());
4521 }
4522 }
4523 ClassType cls = (ClassType)t;
4524 if (cls.isRaw() || !cls.isParameterized())
4525 return cls;
4526
4527 ClassType G = (ClassType)cls.asElement().asType();
4528 List<Type> A = G.getTypeArguments();
4529 List<Type> T = cls.getTypeArguments();
4530 List<Type> S = freshTypeVariables(T);
4531
4532 List<Type> currentA = A;
4533 List<Type> currentT = T;
4534 List<Type> currentS = S;
4535 boolean captured = false;
4536 while (!currentA.isEmpty() &&
4537 !currentT.isEmpty() &&
4538 !currentS.isEmpty()) {
4539 if (currentS.head != currentT.head) {
4540 captured = true;
4541 WildcardType Ti = (WildcardType)currentT.head;
4542 Type Ui = currentA.head.getUpperBound();
4543 CapturedType Si = (CapturedType)currentS.head;
4544 if (Ui == null)
4545 Ui = syms.objectType;
4546 switch (Ti.kind) {
4547 case UNBOUND:
4548 Si.setUpperBound( subst(Ui, A, S) );
4549 Si.lower = syms.botType;
4550 break;
4551 case EXTENDS:
4552 Si.setUpperBound( glb(Ti.getExtendsBound(), subst(Ui, A, S)) );
4553 Si.lower = syms.botType;
4554 break;
4555 case SUPER:
4556 Si.setUpperBound( subst(Ui, A, S) );
4557 Si.lower = Ti.getSuperBound();
4558 break;
4559 }
4560 Type tmpBound = Si.getUpperBound().hasTag(UNDETVAR) ? ((UndetVar)Si.getUpperBound()).qtype : Si.getUpperBound();
4561 Type tmpLower = Si.lower.hasTag(UNDETVAR) ? ((UndetVar)Si.lower).qtype : Si.lower;
4562 if (!Si.getUpperBound().hasTag(ERROR) &&
4563 !Si.lower.hasTag(ERROR) &&
4564 isSameType(tmpBound, tmpLower)) {
4565 currentS.head = Si.getUpperBound();
4566 }
4567 }
4568 currentA = currentA.tail;
4569 currentT = currentT.tail;
4570 currentS = currentS.tail;
4571 }
4572 if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty())
4573 return erasure(t); // some "rare" type involved
4574
4575 if (captured)
4576 return new ClassType(cls.getEnclosingType(), S, cls.tsym,
4577 cls.getMetadata(), cls.getFlavor());
4578 else
4579 return t;
4580 }
4581 // where
4582 public List<Type> freshTypeVariables(List<Type> types) {
4583 ListBuffer<Type> result = new ListBuffer<>();
4584 for (Type t : types) {
4585 if (t.hasTag(WILDCARD)) {
4586 Type bound = ((WildcardType)t).getExtendsBound();
4587 if (bound == null)
4588 bound = syms.objectType;
4589 result.append(new CapturedType(capturedName,
4590 syms.noSymbol,
4591 bound,
4592 syms.botType,
4593 (WildcardType)t));
4594 } else {
4595 result.append(t);
4596 }
4597 }
4598 return result.toList();
4599 }
4600 // </editor-fold>
4601
4602 // <editor-fold defaultstate="collapsed" desc="Internal utility methods">
4603 private boolean sideCast(Type from, Type to, Warner warn) {
4604 // We are casting from type $from$ to type $to$, which are
4605 // non-final unrelated types. This method
4606 // tries to reject a cast by transferring type parameters
4607 // from $to$ to $from$ by common superinterfaces.
4608 boolean reverse = false;
4609 Type target = to;
4610 if ((to.tsym.flags() & INTERFACE) == 0) {
4611 Assert.check((from.tsym.flags() & INTERFACE) != 0);
4612 reverse = true;
4613 to = from;
4614 from = target;
4615 }
4616 List<Type> commonSupers = superClosure(to, erasure(from));
4617 boolean giveWarning = commonSupers.isEmpty();
4618 // The arguments to the supers could be unified here to
4619 // get a more accurate analysis
4620 while (commonSupers.nonEmpty()) {
4621 Type t1 = asSuper(from, commonSupers.head.tsym);
4622 Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym);
4623 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4624 return false;
4625 giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2));
4626 commonSupers = commonSupers.tail;
4627 }
4628 if (giveWarning && !isReifiable(reverse ? from : to))
4629 warn.warn(LintCategory.UNCHECKED);
4630 return true;
4631 }
4632
4633 private boolean sideCastFinal(Type from, Type to, Warner warn) {
4634 // We are casting from type $from$ to type $to$, which are
4635 // unrelated types one of which is final and the other of
4636 // which is an interface. This method
4637 // tries to reject a cast by transferring type parameters
4638 // from the final class to the interface.
4639 boolean reverse = false;
4640 Type target = to;
4641 if ((to.tsym.flags() & INTERFACE) == 0) {
4642 Assert.check((from.tsym.flags() & INTERFACE) != 0);
4643 reverse = true;
4644 to = from;
4645 from = target;
4646 }
4647 Assert.check((from.tsym.flags() & FINAL) != 0);
4648 Type t1 = asSuper(from, to.tsym);
4649 if (t1 == null) return false;
4650 Type t2 = to;
4651 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4652 return false;
4653 if (!isReifiable(target) &&
4654 (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)))
4655 warn.warn(LintCategory.UNCHECKED);
4656 return true;
4657 }
4658
4659 private boolean giveWarning(Type from, Type to) {
4660 List<Type> bounds = to.isCompound() ?
4661 directSupertypes(to) : List.of(to);
4662 for (Type b : bounds) {
4663 Type subFrom = asSub(from, b.tsym);
4664 if (b.isParameterized() &&
4665 (!(isUnbounded(b) ||
4666 isSubtype(from, b) ||
4667 ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) {
4668 return true;
4669 }
4670 }
4671 return false;
4672 }
4673
4674 private List<Type> superClosure(Type t, Type s) {
4675 List<Type> cl = List.nil();
4676 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
4677 if (isSubtype(s, erasure(l.head))) {
4678 cl = insert(cl, l.head);
4679 } else {
4680 cl = union(cl, superClosure(l.head, s));
4681 }
4682 }
4683 return cl;
4684 }
4685
4686 private boolean containsTypeEquivalent(Type t, Type s) {
4687 return isSameType(t, s) || // shortcut
4688 containsType(t, s) && containsType(s, t);
4689 }
4690
4691 // <editor-fold defaultstate="collapsed" desc="adapt">
4692 /**
4693 * Adapt a type by computing a substitution which maps a source
4694 * type to a target type.
4695 *
4696 * @param source the source type
4697 * @param target the target type
4698 * @param from the type variables of the computed substitution
4699 * @param to the types of the computed substitution.
4700 */
4701 public void adapt(Type source,
4702 Type target,
4703 ListBuffer<Type> from,
4704 ListBuffer<Type> to) throws AdaptFailure {
4705 new Adapter(from, to).adapt(source, target);
4706 }
4707
4708 class Adapter extends SimpleVisitor<Void, Type> {
4709
4710 ListBuffer<Type> from;
4711 ListBuffer<Type> to;
4712 Map<Symbol,Type> mapping;
4713
4714 Adapter(ListBuffer<Type> from, ListBuffer<Type> to) {
4715 this.from = from;
4716 this.to = to;
4717 mapping = new HashMap<>();
4718 }
4719
4720 public void adapt(Type source, Type target) throws AdaptFailure {
4721 visit(source, target);
4722 List<Type> fromList = from.toList();
4723 List<Type> toList = to.toList();
4724 while (!fromList.isEmpty()) {
4725 Type val = mapping.get(fromList.head.tsym);
4726 if (toList.head != val)
4727 toList.head = val;
4728 fromList = fromList.tail;
4729 toList = toList.tail;
4730 }
4731 }
4732
4733 @Override
4734 public Void visitClassType(ClassType source, Type target) throws AdaptFailure {
4735 if (target.hasTag(CLASS))
4736 adaptRecursive(source.allparams(), target.allparams());
4737 return null;
4738 }
4739
4740 @Override
4741 public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure {
4742 if (target.hasTag(ARRAY))
4743 adaptRecursive(elemtype(source), elemtype(target));
4744 return null;
4745 }
4746
4747 @Override
4748 public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure {
4749 if (source.isExtendsBound())
4750 adaptRecursive(wildUpperBound(source), wildUpperBound(target));
4751 else if (source.isSuperBound())
4752 adaptRecursive(wildLowerBound(source), wildLowerBound(target));
4753 return null;
4754 }
4755
4756 @Override
4757 public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure {
4758 // Check to see if there is
4759 // already a mapping for $source$, in which case
4760 // the old mapping will be merged with the new
4761 Type val = mapping.get(source.tsym);
4762 if (val != null) {
4763 if (val.isSuperBound() && target.isSuperBound()) {
4764 val = isSubtype(wildLowerBound(val), wildLowerBound(target))
4765 ? target : val;
4766 } else if (val.isExtendsBound() && target.isExtendsBound()) {
4767 val = isSubtype(wildUpperBound(val), wildUpperBound(target))
4768 ? val : target;
4769 } else if (!isSameType(val, target)) {
4770 throw new AdaptFailure();
4771 }
4772 } else {
4773 val = target;
4774 from.append(source);
4775 to.append(target);
4776 }
4777 mapping.put(source.tsym, val);
4778 return null;
4779 }
4780
4781 @Override
4782 public Void visitType(Type source, Type target) {
4783 return null;
4784 }
4785
4786 private Set<TypePair> cache = new HashSet<>();
4787
4788 private void adaptRecursive(Type source, Type target) {
4789 TypePair pair = new TypePair(source, target);
4790 if (cache.add(pair)) {
4791 try {
4792 visit(source, target);
4793 } finally {
4794 cache.remove(pair);
4795 }
4796 }
4797 }
4798
4799 private void adaptRecursive(List<Type> source, List<Type> target) {
4800 if (source.length() == target.length()) {
4801 while (source.nonEmpty()) {
4802 adaptRecursive(source.head, target.head);
4803 source = source.tail;
4804 target = target.tail;
4805 }
4806 }
4807 }
4808 }
4809
4810 public static class AdaptFailure extends RuntimeException {
4811 static final long serialVersionUID = -7490231548272701566L;
4812 }
4813
4814 private void adaptSelf(Type t,
4815 ListBuffer<Type> from,
4816 ListBuffer<Type> to) {
4817 try {
4818 //if (t.tsym.type != t)
4819 adapt(t.tsym.type, t, from, to);
4820 } catch (AdaptFailure ex) {
4821 // Adapt should never fail calculating a mapping from
4822 // t.tsym.type to t as there can be no merge problem.
4823 throw new AssertionError(ex);
4824 }
4825 }
4826 // </editor-fold>
4827
4828 /**
4829 * Rewrite all type variables (universal quantifiers) in the given
4830 * type to wildcards (existential quantifiers). This is used to
4831 * determine if a cast is allowed. For example, if high is true
4832 * and {@code T <: Number}, then {@code List<T>} is rewritten to
4833 * {@code List<? extends Number>}. Since {@code List<Integer> <:
4834 * List<? extends Number>} a {@code List<T>} can be cast to {@code
4835 * List<Integer>} with a warning.
4836 * @param t a type
4837 * @param high if true return an upper bound; otherwise a lower
4838 * bound
4839 * @param rewriteTypeVars only rewrite captured wildcards if false;
4840 * otherwise rewrite all type variables
4841 * @return the type rewritten with wildcards (existential
4842 * quantifiers) only
4843 */
4844 private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) {
4845 return new Rewriter(high, rewriteTypeVars).visit(t);
4846 }
4847
4848 class Rewriter extends UnaryVisitor<Type> {
4849
4850 boolean high;
4851 boolean rewriteTypeVars;
4852
4853 Rewriter(boolean high, boolean rewriteTypeVars) {
4854 this.high = high;
4855 this.rewriteTypeVars = rewriteTypeVars;
4856 }
4857
4858 @Override
4859 public Type visitClassType(ClassType t, Void s) {
4860 ListBuffer<Type> rewritten = new ListBuffer<>();
4861 boolean changed = false;
4862 for (Type arg : t.allparams()) {
4863 Type bound = visit(arg);
4864 if (arg != bound) {
4865 changed = true;
4866 }
4867 rewritten.append(bound);
4868 }
4869 if (changed)
4870 return subst(t.tsym.type,
4871 t.tsym.type.allparams(),
4872 rewritten.toList());
4873 else
4874 return t;
4875 }
4876
4877 public Type visitType(Type t, Void s) {
4878 return t;
4879 }
4880
4881 @Override
4882 public Type visitCapturedType(CapturedType t, Void s) {
4883 Type w_bound = t.wildcard.type;
4884 Type bound = w_bound.contains(t) ?
4885 erasure(w_bound) :
4886 visit(w_bound);
4887 return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind);
4888 }
4889
4890 @Override
4891 public Type visitTypeVar(TypeVar t, Void s) {
4892 if (rewriteTypeVars) {
4893 Type bound = t.getUpperBound().contains(t) ?
4894 erasure(t.getUpperBound()) :
4895 visit(t.getUpperBound());
4896 return rewriteAsWildcardType(bound, t, EXTENDS);
4897 } else {
4898 return t;
4899 }
4900 }
4901
4902 @Override
4903 public Type visitWildcardType(WildcardType t, Void s) {
4904 Type bound2 = visit(t.type);
4905 return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind);
4906 }
4907
4908 private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) {
4909 switch (bk) {
4910 case EXTENDS: return high ?
4911 makeExtendsWildcard(B(bound), formal) :
4912 makeExtendsWildcard(syms.objectType, formal);
4913 case SUPER: return high ?
4914 makeSuperWildcard(syms.botType, formal) :
4915 makeSuperWildcard(B(bound), formal);
4916 case UNBOUND: return makeExtendsWildcard(syms.objectType, formal);
4917 default:
4918 Assert.error("Invalid bound kind " + bk);
4919 return null;
4920 }
4921 }
4922
4923 Type B(Type t) {
4924 while (t.hasTag(WILDCARD)) {
4925 WildcardType w = (WildcardType)t;
4926 t = high ?
4927 w.getExtendsBound() :
4928 w.getSuperBound();
4929 if (t == null) {
4930 t = high ? syms.objectType : syms.botType;
4931 }
4932 }
4933 return t;
4934 }
4935 }
4936
4937
4938 /**
4939 * Create a wildcard with the given upper (extends) bound; create
4940 * an unbounded wildcard if bound is Object.
4941 *
4942 * @param bound the upper bound
4943 * @param formal the formal type parameter that will be
4944 * substituted by the wildcard
4945 */
4946 private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) {
4947 if (bound == syms.objectType) {
4948 return new WildcardType(syms.objectType,
4949 BoundKind.UNBOUND,
4950 syms.boundClass,
4951 formal);
4952 } else {
4953 return new WildcardType(bound,
4954 BoundKind.EXTENDS,
4955 syms.boundClass,
4956 formal);
4957 }
4958 }
4959
4960 /**
4961 * Create a wildcard with the given lower (super) bound; create an
4962 * unbounded wildcard if bound is bottom (type of {@code null}).
4963 *
4964 * @param bound the lower bound
4965 * @param formal the formal type parameter that will be
4966 * substituted by the wildcard
4967 */
4968 private WildcardType makeSuperWildcard(Type bound, TypeVar formal) {
4969 if (bound.hasTag(BOT)) {
4970 return new WildcardType(syms.objectType,
4971 BoundKind.UNBOUND,
4972 syms.boundClass,
4973 formal);
4974 } else {
4975 return new WildcardType(bound,
4976 BoundKind.SUPER,
4977 syms.boundClass,
4978 formal);
4979 }
4980 }
4981
4982 /**
4983 * A wrapper for a type that allows use in sets.
4984 */
4985 public static class UniqueType {
4986 public final Type type;
4987 final Types types;
4988 private boolean encodeTypeSig;
4989
4990 public UniqueType(Type type, Types types, boolean encodeTypeSig) {
4991 this.type = type;
4992 this.types = types;
4993 this.encodeTypeSig = encodeTypeSig;
4994 }
4995
4996 public UniqueType(Type type, Types types) {
4997 this(type, types, true);
4998 }
4999
5000 public int hashCode() {
5001 return types.hashCode(type);
5002 }
5003
5004 public boolean equals(Object obj) {
5005 return (obj instanceof UniqueType uniqueType) &&
5006 types.isSameType(type, uniqueType.type);
5007 }
5008
5009 public boolean encodeTypeSig() {
5010 return encodeTypeSig;
5011 }
5012
5013 public String toString() {
5014 return type.toString();
5015 }
5016
5017 }
5018 // </editor-fold>
5019
5020 // <editor-fold defaultstate="collapsed" desc="Visitors">
5021 /**
5022 * A default visitor for types. All visitor methods except
5023 * visitType are implemented by delegating to visitType. Concrete
5024 * subclasses must provide an implementation of visitType and can
5025 * override other methods as needed.
5026 *
5027 * @param <R> the return type of the operation implemented by this
5028 * visitor; use Void if no return type is needed.
5029 * @param <S> the type of the second argument (the first being the
5030 * type itself) of the operation implemented by this visitor; use
5031 * Void if a second argument is not needed.
5032 */
5033 public abstract static class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> {
5034 public final R visit(Type t, S s) { return t.accept(this, s); }
5035 public R visitClassType(ClassType t, S s) { return visitType(t, s); }
5036 public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); }
5037 public R visitArrayType(ArrayType t, S s) { return visitType(t, s); }
5038 public R visitMethodType(MethodType t, S s) { return visitType(t, s); }
5039 public R visitPackageType(PackageType t, S s) { return visitType(t, s); }
5040 public R visitModuleType(ModuleType t, S s) { return visitType(t, s); }
5041 public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); }
5042 public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); }
5043 public R visitForAll(ForAll t, S s) { return visitType(t, s); }
5044 public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); }
5045 public R visitErrorType(ErrorType t, S s) { return visitType(t, s); }
5046 }
5047
5048 /**
5049 * A default visitor for symbols. All visitor methods except
5050 * visitSymbol are implemented by delegating to visitSymbol. Concrete
5051 * subclasses must provide an implementation of visitSymbol and can
5052 * override other methods as needed.
5053 *
5054 * @param <R> the return type of the operation implemented by this
5055 * visitor; use Void if no return type is needed.
5056 * @param <S> the type of the second argument (the first being the
5057 * symbol itself) of the operation implemented by this visitor; use
5058 * Void if a second argument is not needed.
5059 */
5060 public abstract static class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> {
5061 public final R visit(Symbol s, S arg) { return s.accept(this, arg); }
5062 public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); }
5063 public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); }
5064 public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); }
5065 public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); }
5066 public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); }
5067 public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); }
5068 }
5069
5070 /**
5071 * A <em>simple</em> visitor for types. This visitor is simple as
5072 * captured wildcards, for-all types (generic methods), and
5073 * undetermined type variables (part of inference) are hidden.
5074 * Captured wildcards are hidden by treating them as type
5075 * variables and the rest are hidden by visiting their qtypes.
5076 *
5077 * @param <R> the return type of the operation implemented by this
5078 * visitor; use Void if no return type is needed.
5079 * @param <S> the type of the second argument (the first being the
5080 * type itself) of the operation implemented by this visitor; use
5081 * Void if a second argument is not needed.
5082 */
5083 public abstract static class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> {
5084 @Override
5085 public R visitCapturedType(CapturedType t, S s) {
5086 return visitTypeVar(t, s);
5087 }
5088 @Override
5089 public R visitForAll(ForAll t, S s) {
5090 return visit(t.qtype, s);
5091 }
5092 @Override
5093 public R visitUndetVar(UndetVar t, S s) {
5094 return visit(t.qtype, s);
5095 }
5096 }
5097
5098 /**
5099 * A plain relation on types. That is a 2-ary function on the
5100 * form Type × Type → Boolean.
5101 * <!-- In plain text: Type x Type -> Boolean -->
5102 */
5103 public abstract static class TypeRelation extends SimpleVisitor<Boolean,Type> {}
5104
5105 /**
5106 * A convenience visitor for implementing operations that only
5107 * require one argument (the type itself), that is, unary
5108 * operations.
5109 *
5110 * @param <R> the return type of the operation implemented by this
5111 * visitor; use Void if no return type is needed.
5112 */
5113 public abstract static class UnaryVisitor<R> extends SimpleVisitor<R,Void> {
5114 public final R visit(Type t) { return t.accept(this, null); }
5115 }
5116
5117 /**
5118 * A visitor for implementing a mapping from types to types. The
5119 * default behavior of this class is to implement the identity
5120 * mapping (mapping a type to itself). This can be overridden in
5121 * subclasses.
5122 *
5123 * @param <S> the type of the second argument (the first being the
5124 * type itself) of this mapping; use Void if a second argument is
5125 * not needed.
5126 */
5127 public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> {
5128 public final Type visit(Type t) { return t.accept(this, null); }
5129 public Type visitType(Type t, S s) { return t; }
5130 }
5131
5132 /**
5133 * An abstract class for mappings from types to types (see {@link Type#map(TypeMapping)}.
5134 * This class implements the functional interface {@code Function}, that allows it to be used
5135 * fluently in stream-like processing.
5136 */
5137 public static class TypeMapping<S> extends MapVisitor<S> implements Function<Type, Type> {
5138 @Override
5139 public Type apply(Type type) { return visit(type); }
5140
5141 List<Type> visit(List<Type> ts, S s) {
5142 return ts.map(t -> visit(t, s));
5143 }
5144
5145 @Override
5146 public Type visitCapturedType(CapturedType t, S s) {
5147 return visitTypeVar(t, s);
5148 }
5149 }
5150 // </editor-fold>
5151
5152
5153 // <editor-fold defaultstate="collapsed" desc="Annotation support">
5154
5155 public RetentionPolicy getRetention(Attribute.Compound a) {
5156 return getRetention(a.type.tsym);
5157 }
5158
5159 public RetentionPolicy getRetention(TypeSymbol sym) {
5160 RetentionPolicy vis = RetentionPolicy.CLASS; // the default
5161 Attribute.Compound c = sym.attribute(syms.retentionType.tsym);
5162 if (c != null) {
5163 Attribute value = c.member(names.value);
5164 if (value != null && value instanceof Attribute.Enum attributeEnum) {
5165 Name levelName = attributeEnum.value.name;
5166 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE;
5167 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS;
5168 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME;
5169 else ;// /* fail soft */ throw new AssertionError(levelName);
5170 }
5171 }
5172 return vis;
5173 }
5174 // </editor-fold>
5175
5176 // <editor-fold defaultstate="collapsed" desc="Signature Generation">
5177
5178 public abstract static class SignatureGenerator {
5179
5180 public static class InvalidSignatureException extends RuntimeException {
5181 private static final long serialVersionUID = 0;
5182
5183 private final transient Type type;
5184
5185 InvalidSignatureException(Type type) {
5186 this.type = type;
5187 }
5188
5189 public Type type() {
5190 return type;
5191 }
5192
5193 @Override
5194 public Throwable fillInStackTrace() {
5195 // This is an internal exception; the stack trace is irrelevant.
5196 return this;
5197 }
5198 }
5199
5200 private final Types types;
5201
5202 protected abstract void append(char ch);
5203 protected abstract void append(byte[] ba);
5204 protected abstract void append(Name name);
5205 protected void classReference(ClassSymbol c) { /* by default: no-op */ }
5206
5207 protected SignatureGenerator(Types types) {
5208 this.types = types;
5209 }
5210
5211 protected void reportIllegalSignature(Type t) {
5212 throw new InvalidSignatureException(t);
5213 }
5214
5215 /**
5216 * Assemble signature of given type in string buffer.
5217 */
5218 public void assembleSig(Type type) {
5219 switch (type.getTag()) {
5220 case BYTE:
5221 append('B');
5222 break;
5223 case SHORT:
5224 append('S');
5225 break;
5226 case CHAR:
5227 append('C');
5228 break;
5229 case INT:
5230 append('I');
5231 break;
5232 case LONG:
5233 append('J');
5234 break;
5235 case FLOAT:
5236 append('F');
5237 break;
5238 case DOUBLE:
5239 append('D');
5240 break;
5241 case BOOLEAN:
5242 append('Z');
5243 break;
5244 case VOID:
5245 append('V');
5246 break;
5247 case CLASS:
5248 if (type.isCompound()) {
5249 reportIllegalSignature(type);
5250 }
5251 if (types.allowPrimitiveClasses && type.isPrimitiveClass())
5252 append('Q');
5253 else
5254 append('L');
5255 assembleClassSig(type);
5256 append(';');
5257 break;
5258 case ARRAY:
5259 ArrayType at = (ArrayType) type;
5260 append('[');
5261 assembleSig(at.elemtype);
5262 break;
5263 case METHOD:
5264 MethodType mt = (MethodType) type;
5265 append('(');
5266 assembleSig(mt.argtypes);
5267 append(')');
5268 assembleSig(mt.restype);
5269 if (hasTypeVar(mt.thrown)) {
5270 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) {
5271 append('^');
5272 assembleSig(l.head);
5273 }
5274 }
5275 break;
5276 case WILDCARD: {
5277 Type.WildcardType ta = (Type.WildcardType) type;
5278 switch (ta.kind) {
5279 case SUPER:
5280 append('-');
5281 assembleSig(ta.type);
5282 break;
5283 case EXTENDS:
5284 append('+');
5285 assembleSig(ta.type);
5286 break;
5287 case UNBOUND:
5288 append('*');
5289 break;
5290 default:
5291 throw new AssertionError(ta.kind);
5292 }
5293 break;
5294 }
5295 case TYPEVAR:
5296 if (((TypeVar)type).isCaptured()) {
5297 reportIllegalSignature(type);
5298 }
5299 append('T');
5300 append(type.tsym.name);
5301 append(';');
5302 break;
5303 case FORALL:
5304 Type.ForAll ft = (Type.ForAll) type;
5305 assembleParamsSig(ft.tvars);
5306 assembleSig(ft.qtype);
5307 break;
5308 default:
5309 throw new AssertionError("typeSig " + type.getTag());
5310 }
5311 }
5312
5313 public boolean hasTypeVar(List<Type> l) {
5314 while (l.nonEmpty()) {
5315 if (l.head.hasTag(TypeTag.TYPEVAR)) {
5316 return true;
5317 }
5318 l = l.tail;
5319 }
5320 return false;
5321 }
5322
5323 public void assembleClassSig(Type type) {
5324 ClassType ct = (ClassType) type;
5325 ClassSymbol c = (ClassSymbol) ct.tsym;
5326 classReference(c);
5327 Type outer = ct.getEnclosingType();
5328 if (outer.allparams().nonEmpty()) {
5329 boolean rawOuter =
5330 c.owner.kind == MTH || // either a local class
5331 c.name == types.names.empty; // or anonymous
5332 assembleClassSig(rawOuter
5333 ? types.erasure(outer)
5334 : outer);
5335 append(rawOuter ? '$' : '.');
5336 Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname));
5337 append(rawOuter
5338 ? c.flatname.subName(c.owner.enclClass().flatname.length() + 1)
5339 : c.name);
5340 } else {
5341 append(externalize(c.flatname));
5342 }
5343 if (ct.getTypeArguments().nonEmpty()) {
5344 append('<');
5345 assembleSig(ct.getTypeArguments());
5346 append('>');
5347 }
5348 }
5349
5350 public void assembleParamsSig(List<Type> typarams) {
5351 append('<');
5352 for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) {
5353 Type.TypeVar tvar = (Type.TypeVar) ts.head;
5354 append(tvar.tsym.name);
5355 List<Type> bounds = types.getBounds(tvar);
5356 if ((bounds.head.tsym.flags() & INTERFACE) != 0) {
5357 append(':');
5358 }
5359 for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) {
5360 append(':');
5361 assembleSig(l.head);
5362 }
5363 }
5364 append('>');
5365 }
5366
5367 public void assembleSig(List<Type> types) {
5368 for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) {
5369 assembleSig(ts.head);
5370 }
5371 }
5372 }
5373
5374 public Type constantType(LoadableConstant c) {
5375 switch (c.poolTag()) {
5376 case ClassFile.CONSTANT_Class:
5377 return syms.classType;
5378 case ClassFile.CONSTANT_String:
5379 return syms.stringType;
5380 case ClassFile.CONSTANT_Integer:
5381 return syms.intType;
5382 case ClassFile.CONSTANT_Float:
5383 return syms.floatType;
5384 case ClassFile.CONSTANT_Long:
5385 return syms.longType;
5386 case ClassFile.CONSTANT_Double:
5387 return syms.doubleType;
5388 case ClassFile.CONSTANT_MethodHandle:
5389 return syms.methodHandleType;
5390 case ClassFile.CONSTANT_MethodType:
5391 return syms.methodTypeType;
5392 case ClassFile.CONSTANT_Dynamic:
5393 return ((DynamicVarSymbol)c).type;
5394 default:
5395 throw new AssertionError("Not a loadable constant: " + c.poolTag());
5396 }
5397 }
5398 // </editor-fold>
5399
5400 public void newRound() {
5401 descCache._map.clear();
5402 isDerivedRawCache.clear();
5403 implCache._map.clear();
5404 membersCache._map.clear();
5405 closureCache.clear();
5406 }
5407 }