1 /*
2 * Copyright (c) 2003, 2022, 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.Entry.Kind;
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 allowValueBasedClasses;
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 protected Types(Context context) {
112 context.put(typesKey, this);
113 syms = Symtab.instance(context);
114 names = Names.instance(context);
115 Source source = Source.instance(context);
116 chk = Check.instance(context);
117 enter = Enter.instance(context);
118 capturedName = names.fromString("<captured wildcard>");
119 messages = JavacMessages.instance(context);
120 diags = JCDiagnostic.Factory.instance(context);
121 noWarnings = new Warner(null);
122 Options options = Options.instance(context);
123 allowValueBasedClasses = options.isSet("allowValueBasedClasses");
124 }
125 // </editor-fold>
126
127 // <editor-fold defaultstate="collapsed" desc="bounds">
128 /**
129 * Get a wildcard's upper bound, returning non-wildcards unchanged.
130 * @param t a type argument, either a wildcard or a type
131 */
132 public Type wildUpperBound(Type t) {
133 if (t.hasTag(WILDCARD)) {
134 WildcardType w = (WildcardType) t;
135 if (w.isSuperBound())
136 return w.bound == null ? syms.objectType : w.bound.getUpperBound();
137 else
138 return wildUpperBound(w.type);
139 }
140 else return t;
141 }
142
143 /**
144 * Get a capture variable's upper bound, returning other types unchanged.
145 * @param t a type
146 */
147 public Type cvarUpperBound(Type t) {
148 if (t.hasTag(TYPEVAR)) {
149 TypeVar v = (TypeVar) t;
150 return v.isCaptured() ? cvarUpperBound(v.getUpperBound()) : v;
151 }
152 else return t;
153 }
154
155 /**
156 * Get a wildcard's lower bound, returning non-wildcards unchanged.
157 * @param t a type argument, either a wildcard or a type
158 */
159 public Type wildLowerBound(Type t) {
160 if (t.hasTag(WILDCARD)) {
161 WildcardType w = (WildcardType) t;
162 return w.isExtendsBound() ? syms.botType : wildLowerBound(w.type);
163 }
164 else return t;
165 }
166
167 /**
168 * Get a capture variable's lower bound, returning other types unchanged.
169 * @param t a type
170 */
171 public Type cvarLowerBound(Type t) {
172 if (t.hasTag(TYPEVAR) && ((TypeVar) t).isCaptured()) {
173 return cvarLowerBound(t.getLowerBound());
174 }
175 else return t;
176 }
177
178 /**
179 * Recursively skip type-variables until a class/array type is found; capture conversion is then
180 * (optionally) applied to the resulting type. This is useful for i.e. computing a site that is
181 * suitable for a method lookup.
182 */
183 public Type skipTypeVars(Type site, boolean capture) {
184 while (site.hasTag(TYPEVAR)) {
185 site = site.getUpperBound();
186 }
187 return capture ? capture(site) : site;
188 }
189 // </editor-fold>
190
191 // <editor-fold defaultstate="collapsed" desc="projections">
192
193 /**
194 * A projection kind. See {@link TypeProjection}
195 */
196 enum ProjectionKind {
197 UPWARDS() {
198 @Override
199 ProjectionKind complement() {
200 return DOWNWARDS;
201 }
202 },
203 DOWNWARDS() {
204 @Override
205 ProjectionKind complement() {
206 return UPWARDS;
207 }
208 };
209
210 abstract ProjectionKind complement();
211 }
212
213 /**
214 * This visitor performs upwards and downwards projections on types.
215 *
216 * A projection is defined as a function that takes a type T, a set of type variables V and that
217 * produces another type S.
218 *
219 * An upwards projection maps a type T into a type S such that (i) T has no variables in V,
220 * and (ii) S is an upper bound of T.
221 *
222 * A downwards projection maps a type T into a type S such that (i) T has no variables in V,
223 * and (ii) S is a lower bound of T.
224 *
225 * Note that projections are only allowed to touch variables in V. Therefore, it is possible for
226 * a projection to leave its input type unchanged if it does not contain any variables in V.
227 *
228 * Moreover, note that while an upwards projection is always defined (every type as an upper bound),
229 * a downwards projection is not always defined.
230 *
231 * Examples:
232 *
233 * {@code upwards(List<#CAP1>, [#CAP1]) = List<? extends String>, where #CAP1 <: String }
234 * {@code downwards(List<#CAP2>, [#CAP2]) = List<? super String>, where #CAP2 :> String }
235 * {@code upwards(List<#CAP1>, [#CAP2]) = List<#CAP1> }
236 * {@code downwards(List<#CAP1>, [#CAP1]) = not defined }
237 */
238 class TypeProjection extends TypeMapping<ProjectionKind> {
239
240 List<Type> vars;
241 Set<Type> seen = new HashSet<>();
242
243 public TypeProjection(List<Type> vars) {
244 this.vars = vars;
245 }
246
247 @Override
248 public Type visitClassType(ClassType t, ProjectionKind pkind) {
249 if (t.isCompound()) {
250 List<Type> components = directSupertypes(t);
251 List<Type> components1 = components.map(c -> c.map(this, pkind));
252 if (components == components1) return t;
253 else return makeIntersectionType(components1);
254 } else {
255 Type outer = t.getEnclosingType();
256 Type outer1 = visit(outer, pkind);
257 List<Type> typarams = t.getTypeArguments();
258 List<Type> formals = t.tsym.type.getTypeArguments();
259 ListBuffer<Type> typarams1 = new ListBuffer<>();
260 boolean changed = false;
261 for (Type actual : typarams) {
262 Type t2 = mapTypeArgument(t, formals.head.getUpperBound(), actual, pkind);
263 if (t2.hasTag(BOT)) {
264 //not defined
265 return syms.botType;
266 }
267 typarams1.add(t2);
268 changed |= actual != t2;
269 formals = formals.tail;
270 }
271 if (outer1 == outer && !changed) return t;
272 else return new ClassType(outer1, typarams1.toList(), t.tsym, t.getMetadata(), t.getFlavor()) {
273 @Override
274 protected boolean needsStripping() {
275 return true;
276 }
277 };
278 }
279 }
280
281 @Override
282 public Type visitArrayType(ArrayType t, ProjectionKind s) {
283 Type elemtype = t.elemtype;
284 Type elemtype1 = visit(elemtype, s);
285 if (elemtype1 == elemtype) {
286 return t;
287 } else if (elemtype1.hasTag(BOT)) {
288 //undefined
289 return syms.botType;
290 } else {
291 return new ArrayType(elemtype1, t.tsym, t.metadata) {
292 @Override
293 protected boolean needsStripping() {
294 return true;
295 }
296 };
297 }
298 }
299
300 @Override
301 public Type visitTypeVar(TypeVar t, ProjectionKind pkind) {
302 if (vars.contains(t)) {
303 if (seen.add(t)) {
304 try {
305 final Type bound;
306 switch (pkind) {
307 case UPWARDS:
308 bound = t.getUpperBound();
309 break;
310 case DOWNWARDS:
311 bound = (t.getLowerBound() == null) ?
312 syms.botType :
313 t.getLowerBound();
314 break;
315 default:
316 Assert.error();
317 return null;
318 }
319 return bound.map(this, pkind);
320 } finally {
321 seen.remove(t);
322 }
323 } else {
324 //cycle
325 return pkind == ProjectionKind.UPWARDS ?
326 syms.objectType : syms.botType;
327 }
328 } else {
329 return t;
330 }
331 }
332
333 private Type mapTypeArgument(Type site, Type declaredBound, Type t, ProjectionKind pkind) {
334 return t.containsAny(vars) ?
335 t.map(new TypeArgumentProjection(site, declaredBound), pkind) :
336 t;
337 }
338
339 class TypeArgumentProjection extends TypeMapping<ProjectionKind> {
340
341 Type site;
342 Type declaredBound;
343
344 TypeArgumentProjection(Type site, Type declaredBound) {
345 this.site = site;
346 this.declaredBound = declaredBound;
347 }
348
349 @Override
350 public Type visitType(Type t, ProjectionKind pkind) {
351 //type argument is some type containing restricted vars
352 if (pkind == ProjectionKind.DOWNWARDS) {
353 //not defined
354 return syms.botType;
355 }
356 Type upper = t.map(TypeProjection.this, ProjectionKind.UPWARDS);
357 Type lower = t.map(TypeProjection.this, ProjectionKind.DOWNWARDS);
358 List<Type> formals = site.tsym.type.getTypeArguments();
359 BoundKind bk;
360 Type bound;
361 if (!isSameType(upper, syms.objectType) &&
362 (declaredBound.containsAny(formals) ||
363 !isSubtype(declaredBound, upper))) {
364 bound = upper;
365 bk = EXTENDS;
366 } else if (!lower.hasTag(BOT)) {
367 bound = lower;
368 bk = SUPER;
369 } else {
370 bound = syms.objectType;
371 bk = UNBOUND;
372 }
373 return makeWildcard(bound, bk);
374 }
375
376 @Override
377 public Type visitWildcardType(WildcardType wt, ProjectionKind pkind) {
378 //type argument is some wildcard whose bound contains restricted vars
379 Type bound = syms.botType;
380 BoundKind bk = wt.kind;
381 switch (wt.kind) {
382 case EXTENDS:
383 bound = wt.type.map(TypeProjection.this, pkind);
384 if (bound.hasTag(BOT)) {
385 return syms.botType;
386 }
387 break;
388 case SUPER:
389 bound = wt.type.map(TypeProjection.this, pkind.complement());
390 if (bound.hasTag(BOT)) {
391 bound = syms.objectType;
392 bk = UNBOUND;
393 }
394 break;
395 }
396 return makeWildcard(bound, bk);
397 }
398
399 private Type makeWildcard(Type bound, BoundKind bk) {
400 return new WildcardType(bound, bk, syms.boundClass) {
401 @Override
402 protected boolean needsStripping() {
403 return true;
404 }
405 };
406 }
407 }
408 }
409
410 /**
411 * Computes an upward projection of given type, and vars. See {@link TypeProjection}.
412 *
413 * @param t the type to be projected
414 * @param vars the set of type variables to be mapped
415 * @return the type obtained as result of the projection
416 */
417 public Type upward(Type t, List<Type> vars) {
418 return t.map(new TypeProjection(vars), ProjectionKind.UPWARDS);
419 }
420
421 /**
422 * Computes the set of captured variables mentioned in a given type. See {@link CaptureScanner}.
423 * This routine is typically used to computed the input set of variables to be used during
424 * an upwards projection (see {@link Types#upward(Type, List)}).
425 *
426 * @param t the type where occurrences of captured variables have to be found
427 * @return the set of captured variables found in t
428 */
429 public List<Type> captures(Type t) {
430 CaptureScanner cs = new CaptureScanner();
431 Set<Type> captures = new HashSet<>();
432 cs.visit(t, captures);
433 return List.from(captures);
434 }
435
436 /**
437 * This visitor scans a type recursively looking for occurrences of captured type variables.
438 */
439 class CaptureScanner extends SimpleVisitor<Void, Set<Type>> {
440
441 @Override
442 public Void visitType(Type t, Set<Type> types) {
443 return null;
444 }
445
446 @Override
447 public Void visitClassType(ClassType t, Set<Type> seen) {
448 if (t.isCompound()) {
449 directSupertypes(t).forEach(s -> visit(s, seen));
450 } else {
451 t.allparams().forEach(ta -> visit(ta, seen));
452 }
453 return null;
454 }
455
456 @Override
457 public Void visitArrayType(ArrayType t, Set<Type> seen) {
458 return visit(t.elemtype, seen);
459 }
460
461 @Override
462 public Void visitWildcardType(WildcardType t, Set<Type> seen) {
463 visit(t.type, seen);
464 return null;
465 }
466
467 @Override
468 public Void visitTypeVar(TypeVar t, Set<Type> seen) {
469 if ((t.tsym.flags() & Flags.SYNTHETIC) != 0 && seen.add(t)) {
470 visit(t.getUpperBound(), seen);
471 }
472 return null;
473 }
474
475 @Override
476 public Void visitCapturedType(CapturedType t, Set<Type> seen) {
477 if (seen.add(t)) {
478 visit(t.getUpperBound(), seen);
479 visit(t.getLowerBound(), seen);
480 }
481 return null;
482 }
483 }
484
485 // </editor-fold>
486
487 // <editor-fold defaultstate="collapsed" desc="isUnbounded">
488 /**
489 * Checks that all the arguments to a class are unbounded
490 * wildcards or something else that doesn't make any restrictions
491 * on the arguments. If a class isUnbounded, a raw super- or
492 * subclass can be cast to it without a warning.
493 * @param t a type
494 * @return true iff the given type is unbounded or raw
495 */
496 public boolean isUnbounded(Type t) {
497 return isUnbounded.visit(t);
498 }
499 // where
500 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() {
501
502 public Boolean visitType(Type t, Void ignored) {
503 return true;
504 }
505
506 @Override
507 public Boolean visitClassType(ClassType t, Void ignored) {
508 List<Type> parms = t.tsym.type.allparams();
509 List<Type> args = t.allparams();
510 while (parms.nonEmpty()) {
511 WildcardType unb = new WildcardType(syms.objectType,
512 BoundKind.UNBOUND,
513 syms.boundClass,
514 (TypeVar)parms.head);
515 if (!containsType(args.head, unb))
516 return false;
517 parms = parms.tail;
518 args = args.tail;
519 }
520 return true;
521 }
522 };
523 // </editor-fold>
524
525 // <editor-fold defaultstate="collapsed" desc="asSub">
526 /**
527 * Return the least specific subtype of t that starts with symbol
528 * sym. If none exists, return null. The least specific subtype
529 * is determined as follows:
530 *
531 * <p>If there is exactly one parameterized instance of sym that is a
532 * subtype of t, that parameterized instance is returned.<br>
533 * Otherwise, if the plain type or raw type `sym' is a subtype of
534 * type t, the type `sym' itself is returned. Otherwise, null is
535 * returned.
536 */
537 public Type asSub(Type t, Symbol sym) {
538 return asSub.visit(t, sym);
539 }
540 // where
541 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() {
542
543 public Type visitType(Type t, Symbol sym) {
544 return null;
545 }
546
547 @Override
548 public Type visitClassType(ClassType t, Symbol sym) {
549 if (t.tsym == sym)
550 return t;
551 Type base = asSuper(sym.type, t.tsym);
552 if (base == null)
553 return null;
554 ListBuffer<Type> from = new ListBuffer<>();
555 ListBuffer<Type> to = new ListBuffer<>();
556 try {
557 adapt(base, t, from, to);
558 } catch (AdaptFailure ex) {
559 return null;
560 }
561 Type res = subst(sym.type, from.toList(), to.toList());
562 if (!isSubtype(res, t))
563 return null;
564 ListBuffer<Type> openVars = new ListBuffer<>();
565 for (List<Type> l = sym.type.allparams();
566 l.nonEmpty(); l = l.tail)
567 if (res.contains(l.head) && !t.contains(l.head))
568 openVars.append(l.head);
569 if (openVars.nonEmpty()) {
570 if (t.isRaw()) {
571 // The subtype of a raw type is raw
572 res = erasure(res);
573 } else {
574 // Unbound type arguments default to ?
575 List<Type> opens = openVars.toList();
576 ListBuffer<Type> qs = new ListBuffer<>();
577 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) {
578 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND,
579 syms.boundClass, (TypeVar) iter.head));
580 }
581 res = subst(res, opens, qs.toList());
582 }
583 }
584 return res;
585 }
586
587 @Override
588 public Type visitErrorType(ErrorType t, Symbol sym) {
589 return t;
590 }
591 };
592 // </editor-fold>
593
594 // <editor-fold defaultstate="collapsed" desc="isConvertible">
595 /**
596 * Is t a subtype of or convertible via boxing/unboxing
597 * conversion to s?
598 */
599 public boolean isConvertible(Type t, Type s, Warner warn) {
600 if (t.hasTag(ERROR)) {
601 return true;
602 }
603
604 boolean tValue = t.isPrimitiveClass();
605 boolean sValue = s.isPrimitiveClass();
606 if (tValue != sValue) {
607 return tValue ?
608 isSubtype(t.referenceProjection(), s) :
609 !t.hasTag(BOT) && isSubtype(t, s.referenceProjection());
610 }
611
612 boolean tPrimitive = t.isPrimitive();
613 boolean sPrimitive = s.isPrimitive();
614 if (tPrimitive == sPrimitive) {
615 return isSubtypeUnchecked(t, s, warn);
616 }
617 boolean tUndet = t.hasTag(UNDETVAR);
618 boolean sUndet = s.hasTag(UNDETVAR);
619
620 if (tUndet || sUndet) {
621 return tUndet ?
622 isSubtype(t, boxedTypeOrType(s)) :
623 isSubtype(boxedTypeOrType(t), s);
624 }
625
626 return tPrimitive
627 ? isSubtype(boxedClass(t).type, s)
628 : isSubtype(unboxedType(t), s);
629 }
630
631 /**
632 * Is t a subtype of or convertible via boxing/unboxing
633 * conversions to s?
634 */
635 public boolean isConvertible(Type t, Type s) {
636 return isConvertible(t, s, noWarnings);
637 }
638 // </editor-fold>
639
640 // <editor-fold defaultstate="collapsed" desc="findSam">
641
642 /**
643 * Exception used to report a function descriptor lookup failure. The exception
644 * wraps a diagnostic that can be used to generate more details error
645 * messages.
646 */
647 public static class FunctionDescriptorLookupError extends RuntimeException {
648 private static final long serialVersionUID = 0;
649
650 transient JCDiagnostic diagnostic;
651
652 FunctionDescriptorLookupError() {
653 this.diagnostic = null;
654 }
655
656 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) {
657 this.diagnostic = diag;
658 return this;
659 }
660
661 public JCDiagnostic getDiagnostic() {
662 return diagnostic;
663 }
664
665 @Override
666 public Throwable fillInStackTrace() {
667 // This is an internal exception; the stack trace is irrelevant.
668 return this;
669 }
670 }
671
672 /**
673 * A cache that keeps track of function descriptors associated with given
674 * functional interfaces.
675 */
676 class DescriptorCache {
677
678 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<>();
679
680 class FunctionDescriptor {
681 Symbol descSym;
682
683 FunctionDescriptor(Symbol descSym) {
684 this.descSym = descSym;
685 }
686
687 public Symbol getSymbol() {
688 return descSym;
689 }
690
691 public Type getType(Type site) {
692 site = removeWildcards(site);
693 if (site.isIntersection()) {
694 IntersectionClassType ict = (IntersectionClassType)site;
695 for (Type component : ict.getExplicitComponents()) {
696 if (!chk.checkValidGenericType(component)) {
697 //if the inferred functional interface type is not well-formed,
698 //or if it's not a subtype of the original target, issue an error
699 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site)));
700 }
701 }
702 } else {
703 if (!chk.checkValidGenericType(site)) {
704 //if the inferred functional interface type is not well-formed,
705 //or if it's not a subtype of the original target, issue an error
706 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site)));
707 }
708 }
709 return memberType(site, descSym);
710 }
711 }
712
713 class Entry {
714 final FunctionDescriptor cachedDescRes;
715 final int prevMark;
716
717 public Entry(FunctionDescriptor cachedDescRes,
718 int prevMark) {
719 this.cachedDescRes = cachedDescRes;
720 this.prevMark = prevMark;
721 }
722
723 boolean matches(int mark) {
724 return this.prevMark == mark;
725 }
726 }
727
728 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError {
729 Entry e = _map.get(origin);
730 CompoundScope members = membersClosure(origin.type, false);
731 if (e == null ||
732 !e.matches(members.getMark())) {
733 FunctionDescriptor descRes = findDescriptorInternal(origin, members);
734 _map.put(origin, new Entry(descRes, members.getMark()));
735 return descRes;
736 }
737 else {
738 return e.cachedDescRes;
739 }
740 }
741
742 /**
743 * Compute the function descriptor associated with a given functional interface
744 */
745 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin,
746 CompoundScope membersCache) throws FunctionDescriptorLookupError {
747 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0 || origin.isSealed()) {
748 //t must be an interface
749 throw failure("not.a.functional.intf", origin);
750 }
751
752 final ListBuffer<Symbol> abstracts = new ListBuffer<>();
753 for (Symbol sym : membersCache.getSymbols(new DescriptorFilter(origin))) {
754 Type mtype = memberType(origin.type, sym);
755 if (abstracts.isEmpty()) {
756 abstracts.append(sym);
757 } else if ((sym.name == abstracts.first().name &&
758 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) {
759 if (!abstracts.stream().filter(msym -> msym.owner.isSubClass(sym.enclClass(), Types.this))
760 .map(msym -> memberType(origin.type, msym))
761 .anyMatch(abstractMType -> isSubSignature(abstractMType, mtype))) {
762 abstracts.append(sym);
763 }
764 } else {
765 //the target method(s) should be the only abstract members of t
766 throw failure("not.a.functional.intf.1", origin,
767 diags.fragment(Fragments.IncompatibleAbstracts(Kinds.kindName(origin), origin)));
768 }
769 }
770 if (abstracts.isEmpty()) {
771 //t must define a suitable non-generic method
772 throw failure("not.a.functional.intf.1", origin,
773 diags.fragment(Fragments.NoAbstracts(Kinds.kindName(origin), origin)));
774 }
775 FunctionDescriptor descRes;
776 if (abstracts.size() == 1) {
777 descRes = new FunctionDescriptor(abstracts.first());
778 } else { // size > 1
779 descRes = mergeDescriptors(origin, abstracts.toList());
780 if (descRes == null) {
781 //we can get here if the functional interface is ill-formed
782 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>();
783 for (Symbol desc : abstracts) {
784 String key = desc.type.getThrownTypes().nonEmpty() ?
785 "descriptor.throws" : "descriptor";
786 descriptors.append(diags.fragment(key, desc.name,
787 desc.type.getParameterTypes(),
788 desc.type.getReturnType(),
789 desc.type.getThrownTypes()));
790 }
791 JCDiagnostic msg =
792 diags.fragment(Fragments.IncompatibleDescsInFunctionalIntf(Kinds.kindName(origin),
793 origin));
794 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors =
795 new JCDiagnostic.MultilineDiagnostic(msg, descriptors.toList());
796 throw failure(incompatibleDescriptors);
797 }
798 }
799 // an interface must be neither an identity interface nor a value interface to be functional.
800 List<Type> allInterfaces = closure(origin.type);
801 for (Type iface : allInterfaces) {
802 if (iface.isValueInterface()) {
803 throw failure("not.a.functional.intf.1", origin, diags.fragment(Fragments.ValueInterfaceNonfunctional));
804 }
805 if (iface.isIdentityInterface()) {
806 throw failure("not.a.functional.intf.1", origin, diags.fragment(Fragments.IdentityInterfaceNonfunctional));
807 }
808 }
809 return descRes;
810 }
811
812 /**
813 * Compute a synthetic type for the target descriptor given a list
814 * of override-equivalent methods in the functional interface type.
815 * The resulting method type is a method type that is override-equivalent
816 * and return-type substitutable with each method in the original list.
817 */
818 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) {
819 return mergeAbstracts(methodSyms, origin.type, false)
820 .map(bestSoFar -> new FunctionDescriptor(bestSoFar.baseSymbol()) {
821 @Override
822 public Type getType(Type origin) {
823 Type mt = memberType(origin, getSymbol());
824 return createMethodTypeWithThrown(mt, bestSoFar.type.getThrownTypes());
825 }
826 }).orElse(null);
827 }
828
829 FunctionDescriptorLookupError failure(String msg, Object... args) {
830 return failure(diags.fragment(msg, args));
831 }
832
833 FunctionDescriptorLookupError failure(JCDiagnostic diag) {
834 return new FunctionDescriptorLookupError().setMessage(diag);
835 }
836 }
837
838 private DescriptorCache descCache = new DescriptorCache();
839
840 /**
841 * Find the method descriptor associated to this class symbol - if the
842 * symbol 'origin' is not a functional interface, an exception is thrown.
843 */
844 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError {
845 return descCache.get(origin).getSymbol();
846 }
847
848 /**
849 * Find the type of the method descriptor associated to this class symbol -
850 * if the symbol 'origin' is not a functional interface, an exception is thrown.
851 */
852 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError {
853 return descCache.get(origin.tsym).getType(origin);
854 }
855
856 /**
857 * Is given type a functional interface?
858 */
859 public boolean isFunctionalInterface(TypeSymbol tsym) {
860 try {
861 findDescriptorSymbol(tsym);
862 return true;
863 } catch (FunctionDescriptorLookupError ex) {
864 return false;
865 }
866 }
867
868 public boolean isFunctionalInterface(Type site) {
869 try {
870 findDescriptorType(site);
871 return true;
872 } catch (FunctionDescriptorLookupError ex) {
873 return false;
874 }
875 }
876
877 public Type removeWildcards(Type site) {
878 if (site.getTypeArguments().stream().anyMatch(t -> t.hasTag(WILDCARD))) {
879 //compute non-wildcard parameterization - JLS 9.9
880 List<Type> actuals = site.getTypeArguments();
881 List<Type> formals = site.tsym.type.getTypeArguments();
882 ListBuffer<Type> targs = new ListBuffer<>();
883 for (Type formal : formals) {
884 Type actual = actuals.head;
885 Type bound = formal.getUpperBound();
886 if (actuals.head.hasTag(WILDCARD)) {
887 WildcardType wt = (WildcardType)actual;
888 //check that bound does not contain other formals
889 if (bound.containsAny(formals)) {
890 targs.add(wt.type);
891 } else {
892 //compute new type-argument based on declared bound and wildcard bound
893 switch (wt.kind) {
894 case UNBOUND:
895 targs.add(bound);
896 break;
897 case EXTENDS:
898 targs.add(glb(bound, wt.type));
899 break;
900 case SUPER:
901 targs.add(wt.type);
902 break;
903 default:
904 Assert.error("Cannot get here!");
905 }
906 }
907 } else {
908 //not a wildcard - the new type argument remains unchanged
909 targs.add(actual);
910 }
911 actuals = actuals.tail;
912 }
913 return subst(site.tsym.type, formals, targs.toList());
914 } else {
915 return site;
916 }
917 }
918
919 /**
920 * Create a symbol for a class that implements a given functional interface
921 * and overrides its functional descriptor. This routine is used for two
922 * main purposes: (i) checking well-formedness of a functional interface;
923 * (ii) perform functional interface bridge calculation.
924 */
925 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, Type target, long cflags) {
926 if (target == null || target == syms.unknownType) {
927 return null;
928 }
929 Symbol descSym = findDescriptorSymbol(target.tsym);
930 Type descType = findDescriptorType(target);
931 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass());
932 csym.completer = Completer.NULL_COMPLETER;
933 csym.members_field = WriteableScope.create(csym);
934 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym);
935 csym.members_field.enter(instDescSym);
936 Type.ClassType ctype = new Type.ClassType(Type.noType, List.nil(), csym);
937 ctype.supertype_field = syms.objectType;
938 ctype.interfaces_field = target.isIntersection() ?
939 directSupertypes(target) :
940 List.of(target);
941 csym.type = ctype;
942 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile;
943 return csym;
944 }
945
946 /**
947 * Find the minimal set of methods that are overridden by the functional
948 * descriptor in 'origin'. All returned methods are assumed to have different
949 * erased signatures.
950 */
951 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) {
952 Assert.check(isFunctionalInterface(origin));
953 Symbol descSym = findDescriptorSymbol(origin);
954 CompoundScope members = membersClosure(origin.type, false);
955 ListBuffer<Symbol> overridden = new ListBuffer<>();
956 outer: for (Symbol m2 : members.getSymbolsByName(descSym.name, bridgeFilter)) {
957 if (m2 == descSym) continue;
958 else if (descSym.overrides(m2, origin, Types.this, false)) {
959 for (Symbol m3 : overridden) {
960 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) ||
961 (m3.overrides(m2, origin, Types.this, false) &&
962 (pendingBridges((ClassSymbol)origin, m3.enclClass()) ||
963 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) {
964 continue outer;
965 }
966 }
967 overridden.add(m2);
968 }
969 }
970 return overridden.toList();
971 }
972 //where
973 // Use anonymous class instead of lambda expression intentionally,
974 // because the variable `names` has modifier: final.
975 private Predicate<Symbol> bridgeFilter = new Predicate<Symbol>() {
976 public boolean test(Symbol t) {
977 return t.kind == MTH &&
978 t.name != names.init &&
979 t.name != names.clinit &&
980 (t.flags() & SYNTHETIC) == 0;
981 }
982 };
983
984 private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) {
985 //a symbol will be completed from a classfile if (a) symbol has
986 //an associated file object with CLASS kind and (b) the symbol has
987 //not been entered
988 if (origin.classfile != null &&
989 origin.classfile.getKind() == JavaFileObject.Kind.CLASS &&
990 enter.getEnv(origin) == null) {
991 return false;
992 }
993 if (origin == s) {
994 return true;
995 }
996 for (Type t : interfaces(origin.type)) {
997 if (pendingBridges((ClassSymbol)t.tsym, s)) {
998 return true;
999 }
1000 }
1001 return false;
1002 }
1003 // </editor-fold>
1004
1005 /**
1006 * Scope filter used to skip methods that should be ignored (such as methods
1007 * overridden by j.l.Object) during function interface conversion interface check
1008 */
1009 class DescriptorFilter implements Predicate<Symbol> {
1010
1011 TypeSymbol origin;
1012
1013 DescriptorFilter(TypeSymbol origin) {
1014 this.origin = origin;
1015 }
1016
1017 @Override
1018 public boolean test(Symbol sym) {
1019 return sym.kind == MTH &&
1020 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT &&
1021 !overridesObjectMethod(origin, sym) &&
1022 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0;
1023 }
1024 }
1025
1026 // <editor-fold defaultstate="collapsed" desc="isSubtype">
1027 /**
1028 * Is t an unchecked subtype of s?
1029 */
1030 public boolean isSubtypeUnchecked(Type t, Type s) {
1031 return isSubtypeUnchecked(t, s, noWarnings);
1032 }
1033 /**
1034 * Is t an unchecked subtype of s?
1035 */
1036 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) {
1037 boolean result = isSubtypeUncheckedInternal(t, s, true, warn);
1038 if (result) {
1039 checkUnsafeVarargsConversion(t, s, warn);
1040 }
1041 return result;
1042 }
1043 //where
1044 private boolean isSubtypeUncheckedInternal(Type t, Type s, boolean capture, Warner warn) {
1045 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) {
1046 if (((ArrayType)t).elemtype.isPrimitive()) {
1047 return isSameType(elemtype(t), elemtype(s));
1048 } else {
1049 // if T.ref <: S, then T[] <: S[]
1050 Type es = elemtype(s);
1051 Type et = elemtype(t);
1052 if (et.isPrimitiveClass()) {
1053 et = et.referenceProjection();
1054 if (es.isPrimitiveClass())
1055 es = es.referenceProjection(); // V <: V, surely
1056 }
1057 if (!isSubtypeUncheckedInternal(et, es, false, warn))
1058 return false;
1059 return true;
1060 }
1061 } else if (isSubtype(t, s, capture)) {
1062 return true;
1063 } else if (t.hasTag(TYPEVAR)) {
1064 return isSubtypeUncheckedInternal(t.getUpperBound(), s, false, warn);
1065 } else if (!s.isRaw()) {
1066 Type t2 = asSuper(t, s.tsym);
1067 if (t2 != null && t2.isRaw()) {
1068 if (isReifiable(s)) {
1069 warn.silentWarn(LintCategory.UNCHECKED);
1070 } else {
1071 warn.warn(LintCategory.UNCHECKED);
1072 }
1073 return true;
1074 }
1075 }
1076 return false;
1077 }
1078
1079 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) {
1080 if (!t.hasTag(ARRAY) || isReifiable(t)) {
1081 return;
1082 }
1083 ArrayType from = (ArrayType)t;
1084 boolean shouldWarn = false;
1085 switch (s.getTag()) {
1086 case ARRAY:
1087 ArrayType to = (ArrayType)s;
1088 shouldWarn = from.isVarargs() &&
1089 !to.isVarargs() &&
1090 !isReifiable(from);
1091 break;
1092 case CLASS:
1093 shouldWarn = from.isVarargs();
1094 break;
1095 }
1096 if (shouldWarn) {
1097 warn.warn(LintCategory.VARARGS);
1098 }
1099 }
1100
1101 /**
1102 * Is t a subtype of s?<br>
1103 * (not defined for Method and ForAll types)
1104 */
1105 public final boolean isSubtype(Type t, Type s) {
1106 return isSubtype(t, s, true);
1107 }
1108 public final boolean isSubtypeNoCapture(Type t, Type s) {
1109 return isSubtype(t, s, false);
1110 }
1111 public boolean isSubtype(Type t, Type s, boolean capture) {
1112 if (t.equalsIgnoreMetadata(s))
1113 return true;
1114 if (s.isPartial())
1115 return isSuperType(s, t);
1116
1117 if (s.isCompound()) {
1118 for (Type s2 : interfaces(s).prepend(supertype(s))) {
1119 if (!isSubtype(t, s2, capture))
1120 return false;
1121 }
1122 return true;
1123 }
1124
1125 // Generally, if 's' is a lower-bounded type variable, recur on lower bound; but
1126 // for inference variables and intersections, we need to keep 's'
1127 // (see JLS 4.10.2 for intersections and 18.2.3 for inference vars)
1128 if (!t.hasTag(UNDETVAR) && !t.isCompound()) {
1129 // TODO: JDK-8039198, bounds checking sometimes passes in a wildcard as s
1130 Type lower = cvarLowerBound(wildLowerBound(s));
1131 if (s != lower && !lower.hasTag(BOT))
1132 return isSubtype(capture ? capture(t) : t, lower, false);
1133 }
1134
1135 return isSubtype.visit(capture ? capture(t) : t, s);
1136 }
1137 // where
1138 private TypeRelation isSubtype = new TypeRelation()
1139 {
1140 @Override
1141 public Boolean visitType(Type t, Type s) {
1142 switch (t.getTag()) {
1143 case BYTE:
1144 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag()));
1145 case CHAR:
1146 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag()));
1147 case SHORT: case INT: case LONG:
1148 case FLOAT: case DOUBLE:
1149 return t.getTag().isSubRangeOf(s.getTag());
1150 case BOOLEAN: case VOID:
1151 return t.hasTag(s.getTag());
1152 case TYPEVAR:
1153 return isSubtypeNoCapture(t.getUpperBound(), s);
1154 case BOT:
1155 return
1156 s.hasTag(BOT) || (s.hasTag(CLASS) && !s.isPrimitiveClass()) ||
1157 s.hasTag(ARRAY) || s.hasTag(TYPEVAR);
1158 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495)
1159 case NONE:
1160 return false;
1161 default:
1162 throw new AssertionError("isSubtype " + t.getTag());
1163 }
1164 }
1165
1166 private Set<TypePair> cache = new HashSet<>();
1167
1168 private boolean containsTypeRecursive(Type t, Type s) {
1169 TypePair pair = new TypePair(t, s);
1170 if (cache.add(pair)) {
1171 try {
1172 return containsType(t.getTypeArguments(),
1173 s.getTypeArguments());
1174 } finally {
1175 cache.remove(pair);
1176 }
1177 } else {
1178 return containsType(t.getTypeArguments(),
1179 rewriteSupers(s).getTypeArguments());
1180 }
1181 }
1182
1183 private Type rewriteSupers(Type t) {
1184 if (!t.isParameterized())
1185 return t;
1186 ListBuffer<Type> from = new ListBuffer<>();
1187 ListBuffer<Type> to = new ListBuffer<>();
1188 adaptSelf(t, from, to);
1189 if (from.isEmpty())
1190 return t;
1191 ListBuffer<Type> rewrite = new ListBuffer<>();
1192 boolean changed = false;
1193 for (Type orig : to.toList()) {
1194 Type s = rewriteSupers(orig);
1195 if (s.isSuperBound() && !s.isExtendsBound()) {
1196 s = new WildcardType(syms.objectType,
1197 BoundKind.UNBOUND,
1198 syms.boundClass,
1199 s.getMetadata());
1200 changed = true;
1201 } else if (s != orig) {
1202 s = new WildcardType(wildUpperBound(s),
1203 BoundKind.EXTENDS,
1204 syms.boundClass,
1205 s.getMetadata());
1206 changed = true;
1207 }
1208 rewrite.append(s);
1209 }
1210 if (changed)
1211 return subst(t.tsym.type, from.toList(), rewrite.toList());
1212 else
1213 return t;
1214 }
1215
1216 @Override
1217 public Boolean visitClassType(ClassType t, Type s) {
1218 Type sup = asSuper(t, s.tsym);
1219 if (sup == null) return false;
1220 // If t is an intersection, sup might not be a class type
1221 if (!sup.hasTag(CLASS)) return isSubtypeNoCapture(sup, s);
1222 return sup.tsym == s.tsym
1223 && (t.tsym != s.tsym || t.isReferenceProjection() == s.isReferenceProjection())
1224 // Check type variable containment
1225 && (!s.isParameterized() || containsTypeRecursive(s, sup))
1226 && isSubtypeNoCapture(sup.getEnclosingType(),
1227 s.getEnclosingType());
1228 }
1229
1230 @Override
1231 public Boolean visitArrayType(ArrayType t, Type s) {
1232 if (s.hasTag(ARRAY)) {
1233 if (t.elemtype.isPrimitive())
1234 return isSameType(t.elemtype, elemtype(s));
1235 else {
1236 // if T.ref <: S, then T[] <: S[]
1237 Type es = elemtype(s);
1238 Type et = elemtype(t);
1239 if (et.isPrimitiveClass()) {
1240 et = et.referenceProjection();
1241 if (es.isPrimitiveClass())
1242 es = es.referenceProjection(); // V <: V, surely
1243 }
1244 return isSubtypeNoCapture(et, es);
1245 }
1246 }
1247
1248 if (s.hasTag(CLASS)) {
1249 Name sname = s.tsym.getQualifiedName();
1250 return sname == names.java_lang_Object
1251 || sname == names.java_lang_Cloneable
1252 || sname == names.java_io_Serializable;
1253 }
1254
1255 return false;
1256 }
1257
1258 @Override
1259 public Boolean visitUndetVar(UndetVar t, Type s) {
1260 //todo: test against origin needed? or replace with substitution?
1261 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1262 return true;
1263 } else if (s.hasTag(BOT)) {
1264 //if 's' is 'null' there's no instantiated type U for which
1265 //U <: s (but 'null' itself, which is not a valid type)
1266 return false;
1267 }
1268
1269 t.addBound(InferenceBound.UPPER, s, Types.this);
1270 return true;
1271 }
1272
1273 @Override
1274 public Boolean visitErrorType(ErrorType t, Type s) {
1275 return true;
1276 }
1277 };
1278
1279 /**
1280 * Is t a subtype of every type in given list `ts'?<br>
1281 * (not defined for Method and ForAll types)<br>
1282 * Allows unchecked conversions.
1283 */
1284 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) {
1285 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1286 if (!isSubtypeUnchecked(t, l.head, warn))
1287 return false;
1288 return true;
1289 }
1290
1291 /**
1292 * Are corresponding elements of ts subtypes of ss? If lists are
1293 * of different length, return false.
1294 */
1295 public boolean isSubtypes(List<Type> ts, List<Type> ss) {
1296 while (ts.tail != null && ss.tail != null
1297 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1298 isSubtype(ts.head, ss.head)) {
1299 ts = ts.tail;
1300 ss = ss.tail;
1301 }
1302 return ts.tail == null && ss.tail == null;
1303 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1304 }
1305
1306 /**
1307 * Are corresponding elements of ts subtypes of ss, allowing
1308 * unchecked conversions? If lists are of different length,
1309 * return false.
1310 **/
1311 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) {
1312 while (ts.tail != null && ss.tail != null
1313 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1314 isSubtypeUnchecked(ts.head, ss.head, warn)) {
1315 ts = ts.tail;
1316 ss = ss.tail;
1317 }
1318 return ts.tail == null && ss.tail == null;
1319 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1320 }
1321 // </editor-fold>
1322
1323 // <editor-fold defaultstate="collapsed" desc="isSuperType">
1324 /**
1325 * Is t a supertype of s?
1326 */
1327 public boolean isSuperType(Type t, Type s) {
1328 switch (t.getTag()) {
1329 case ERROR:
1330 return true;
1331 case UNDETVAR: {
1332 UndetVar undet = (UndetVar)t;
1333 if (t == s ||
1334 undet.qtype == s ||
1335 s.hasTag(ERROR) ||
1336 s.hasTag(BOT)) {
1337 return true;
1338 }
1339 undet.addBound(InferenceBound.LOWER, s, this);
1340 return true;
1341 }
1342 default:
1343 return isSubtype(s, t);
1344 }
1345 }
1346 // </editor-fold>
1347
1348 // <editor-fold defaultstate="collapsed" desc="isSameType">
1349 /**
1350 * Are corresponding elements of the lists the same type? If
1351 * lists are of different length, return false.
1352 */
1353 public boolean isSameTypes(List<Type> ts, List<Type> ss) {
1354 while (ts.tail != null && ss.tail != null
1355 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1356 isSameType(ts.head, ss.head)) {
1357 ts = ts.tail;
1358 ss = ss.tail;
1359 }
1360 return ts.tail == null && ss.tail == null;
1361 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1362 }
1363
1364 /**
1365 * A polymorphic signature method (JLS 15.12.3) is a method that
1366 * (i) is declared in the java.lang.invoke.MethodHandle/VarHandle classes;
1367 * (ii) takes a single variable arity parameter;
1368 * (iii) whose declared type is Object[];
1369 * (iv) has any return type, Object signifying a polymorphic return type; and
1370 * (v) is native.
1371 */
1372 public boolean isSignaturePolymorphic(MethodSymbol msym) {
1373 List<Type> argtypes = msym.type.getParameterTypes();
1374 return (msym.flags_field & NATIVE) != 0 &&
1375 (msym.owner == syms.methodHandleType.tsym || msym.owner == syms.varHandleType.tsym) &&
1376 argtypes.length() == 1 &&
1377 argtypes.head.hasTag(TypeTag.ARRAY) &&
1378 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym;
1379 }
1380
1381 /**
1382 * Is t the same type as s?
1383 */
1384 public boolean isSameType(Type t, Type s) {
1385 return isSameTypeVisitor.visit(t, s);
1386 }
1387 // where
1388
1389 /**
1390 * Type-equality relation - type variables are considered
1391 * equals if they share the same object identity.
1392 */
1393 TypeRelation isSameTypeVisitor = new TypeRelation() {
1394
1395 public Boolean visitType(Type t, Type s) {
1396 if (t.equalsIgnoreMetadata(s))
1397 return true;
1398
1399 if (s.isPartial())
1400 return visit(s, t);
1401
1402 switch (t.getTag()) {
1403 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1404 case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE:
1405 return t.hasTag(s.getTag());
1406 case TYPEVAR: {
1407 if (s.hasTag(TYPEVAR)) {
1408 //type-substitution does not preserve type-var types
1409 //check that type var symbols and bounds are indeed the same
1410 return t == s;
1411 }
1412 else {
1413 //special case for s == ? super X, where upper(s) = u
1414 //check that u == t, where u has been set by Type.withTypeVar
1415 return s.isSuperBound() &&
1416 !s.isExtendsBound() &&
1417 visit(t, wildUpperBound(s));
1418 }
1419 }
1420 default:
1421 throw new AssertionError("isSameType " + t.getTag());
1422 }
1423 }
1424
1425 @Override
1426 public Boolean visitWildcardType(WildcardType t, Type s) {
1427 if (!s.hasTag(WILDCARD)) {
1428 return false;
1429 } else {
1430 WildcardType t2 = (WildcardType)s;
1431 return (t.kind == t2.kind || (t.isExtendsBound() && s.isExtendsBound())) &&
1432 isSameType(t.type, t2.type);
1433 }
1434 }
1435
1436 @Override
1437 public Boolean visitClassType(ClassType t, Type s) {
1438 if (t == s)
1439 return true;
1440
1441 if (s.isPartial())
1442 return visit(s, t);
1443
1444 if (s.isSuperBound() && !s.isExtendsBound())
1445 return visit(t, wildUpperBound(s)) && visit(t, wildLowerBound(s));
1446
1447 if (t.isCompound() && s.isCompound()) {
1448 if (!visit(supertype(t), supertype(s)))
1449 return false;
1450
1451 Map<Symbol,Type> tMap = new HashMap<>();
1452 for (Type ti : interfaces(t)) {
1453 if (tMap.containsKey(ti)) {
1454 throw new AssertionError("Malformed intersection");
1455 }
1456 tMap.put(ti.tsym, ti);
1457 }
1458 for (Type si : interfaces(s)) {
1459 if (!tMap.containsKey(si.tsym))
1460 return false;
1461 Type ti = tMap.remove(si.tsym);
1462 if (!visit(ti, si))
1463 return false;
1464 }
1465 return tMap.isEmpty();
1466 }
1467 return t.tsym == s.tsym
1468 && t.isReferenceProjection() == s.isReferenceProjection()
1469 && visit(getEnclosingType(t), getEnclosingType(s))
1470 && containsTypeEquivalent(t.getTypeArguments(), s.getTypeArguments());
1471 }
1472 // where
1473 private Type getEnclosingType(Type t) {
1474 Type et = t.getEnclosingType();
1475 if (et.isReferenceProjection()) {
1476 et = et.valueProjection();
1477 }
1478 return et;
1479 }
1480
1481 @Override
1482 public Boolean visitArrayType(ArrayType t, Type s) {
1483 if (t == s)
1484 return true;
1485
1486 if (s.isPartial())
1487 return visit(s, t);
1488
1489 return s.hasTag(ARRAY)
1490 && containsTypeEquivalent(t.elemtype, elemtype(s));
1491 }
1492
1493 @Override
1494 public Boolean visitMethodType(MethodType t, Type s) {
1495 // isSameType for methods does not take thrown
1496 // exceptions into account!
1497 return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType());
1498 }
1499
1500 @Override
1501 public Boolean visitPackageType(PackageType t, Type s) {
1502 return t == s;
1503 }
1504
1505 @Override
1506 public Boolean visitForAll(ForAll t, Type s) {
1507 if (!s.hasTag(FORALL)) {
1508 return false;
1509 }
1510
1511 ForAll forAll = (ForAll)s;
1512 return hasSameBounds(t, forAll)
1513 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
1514 }
1515
1516 @Override
1517 public Boolean visitUndetVar(UndetVar t, Type s) {
1518 if (s.hasTag(WILDCARD)) {
1519 // FIXME, this might be leftovers from before capture conversion
1520 return false;
1521 }
1522
1523 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1524 return true;
1525 }
1526
1527 t.addBound(InferenceBound.EQ, s, Types.this);
1528
1529 return true;
1530 }
1531
1532 @Override
1533 public Boolean visitErrorType(ErrorType t, Type s) {
1534 return true;
1535 }
1536 };
1537
1538 // </editor-fold>
1539
1540 // <editor-fold defaultstate="collapsed" desc="Contains Type">
1541 public boolean containedBy(Type t, Type s) {
1542 switch (t.getTag()) {
1543 case UNDETVAR:
1544 if (s.hasTag(WILDCARD)) {
1545 UndetVar undetvar = (UndetVar)t;
1546 WildcardType wt = (WildcardType)s;
1547 switch(wt.kind) {
1548 case UNBOUND:
1549 break;
1550 case EXTENDS: {
1551 Type bound = wildUpperBound(s);
1552 undetvar.addBound(InferenceBound.UPPER, bound, this);
1553 break;
1554 }
1555 case SUPER: {
1556 Type bound = wildLowerBound(s);
1557 undetvar.addBound(InferenceBound.LOWER, bound, this);
1558 break;
1559 }
1560 }
1561 return true;
1562 } else {
1563 return isSameType(t, s);
1564 }
1565 case ERROR:
1566 return true;
1567 default:
1568 return containsType(s, t);
1569 }
1570 }
1571
1572 boolean containsType(List<Type> ts, List<Type> ss) {
1573 while (ts.nonEmpty() && ss.nonEmpty()
1574 && containsType(ts.head, ss.head)) {
1575 ts = ts.tail;
1576 ss = ss.tail;
1577 }
1578 return ts.isEmpty() && ss.isEmpty();
1579 }
1580
1581 /**
1582 * Check if t contains s.
1583 *
1584 * <p>T contains S if:
1585 *
1586 * <p>{@code L(T) <: L(S) && U(S) <: U(T)}
1587 *
1588 * <p>This relation is only used by ClassType.isSubtype(), that
1589 * is,
1590 *
1591 * <p>{@code C<S> <: C<T> if T contains S.}
1592 *
1593 * <p>Because of F-bounds, this relation can lead to infinite
1594 * recursion. Thus we must somehow break that recursion. Notice
1595 * that containsType() is only called from ClassType.isSubtype().
1596 * Since the arguments have already been checked against their
1597 * bounds, we know:
1598 *
1599 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)}
1600 *
1601 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)}
1602 *
1603 * @param t a type
1604 * @param s a type
1605 */
1606 public boolean containsType(Type t, Type s) {
1607 return containsType.visit(t, s);
1608 }
1609 // where
1610 private TypeRelation containsType = new TypeRelation() {
1611
1612 public Boolean visitType(Type t, Type s) {
1613 if (s.isPartial())
1614 return containedBy(s, t);
1615 else
1616 return isSameType(t, s);
1617 }
1618
1619 // void debugContainsType(WildcardType t, Type s) {
1620 // System.err.println();
1621 // System.err.format(" does %s contain %s?%n", t, s);
1622 // System.err.format(" %s U(%s) <: U(%s) %s = %s%n",
1623 // wildUpperBound(s), s, t, wildUpperBound(t),
1624 // t.isSuperBound()
1625 // || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t)));
1626 // System.err.format(" %s L(%s) <: L(%s) %s = %s%n",
1627 // wildLowerBound(t), t, s, wildLowerBound(s),
1628 // t.isExtendsBound()
1629 // || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s)));
1630 // System.err.println();
1631 // }
1632
1633 @Override
1634 public Boolean visitWildcardType(WildcardType t, Type s) {
1635 if (s.isPartial())
1636 return containedBy(s, t);
1637 else {
1638 // debugContainsType(t, s);
1639
1640 // ----------------------------------- Unspecified behavior ----------------
1641
1642 /* If a primitive class V implements an interface I, then does "? extends I" contain V?
1643 It seems widening must be applied here to answer yes to compile some common code
1644 patterns.
1645 */
1646
1647 // ---------------------------------------------------------------------------
1648 return isSameWildcard(t, s)
1649 || isCaptureOf(s, t)
1650 || ((t.isExtendsBound() || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))) &&
1651 (t.isSuperBound() || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t))));
1652 }
1653 }
1654
1655 @Override
1656 public Boolean visitUndetVar(UndetVar t, Type s) {
1657 if (!s.hasTag(WILDCARD)) {
1658 return isSameType(t, s);
1659 } else {
1660 return false;
1661 }
1662 }
1663
1664 @Override
1665 public Boolean visitErrorType(ErrorType t, Type s) {
1666 return true;
1667 }
1668 };
1669
1670 public boolean isCaptureOf(Type s, WildcardType t) {
1671 if (!s.hasTag(TYPEVAR) || !((TypeVar)s).isCaptured())
1672 return false;
1673 return isSameWildcard(t, ((CapturedType)s).wildcard);
1674 }
1675
1676 public boolean isSameWildcard(WildcardType t, Type s) {
1677 if (!s.hasTag(WILDCARD))
1678 return false;
1679 WildcardType w = (WildcardType)s;
1680 return w.kind == t.kind && w.type == t.type;
1681 }
1682
1683 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) {
1684 while (ts.nonEmpty() && ss.nonEmpty()
1685 && containsTypeEquivalent(ts.head, ss.head)) {
1686 ts = ts.tail;
1687 ss = ss.tail;
1688 }
1689 return ts.isEmpty() && ss.isEmpty();
1690 }
1691 // </editor-fold>
1692
1693 // <editor-fold defaultstate="collapsed" desc="isCastable">
1694 public boolean isCastable(Type t, Type s) {
1695 return isCastable(t, s, noWarnings);
1696 }
1697
1698 /**
1699 * Is t castable to s?<br>
1700 * s is assumed to be an erased type.<br>
1701 * (not defined for Method and ForAll types).
1702 */
1703 public boolean isCastable(Type t, Type s, Warner warn) {
1704 // if same type
1705 if (t == s)
1706 return true;
1707 // if one of the types is primitive
1708 if (t.isPrimitive() != s.isPrimitive()) {
1709 t = skipTypeVars(t, false);
1710 return (isConvertible(t, s, warn)
1711 || (s.isPrimitive() &&
1712 isSubtype(boxedClass(s).type, t)));
1713 }
1714 boolean result;
1715 if (warn != warnStack.head) {
1716 try {
1717 warnStack = warnStack.prepend(warn);
1718 checkUnsafeVarargsConversion(t, s, warn);
1719 result = isCastable.visit(t,s);
1720 } finally {
1721 warnStack = warnStack.tail;
1722 }
1723 } else {
1724 result = isCastable.visit(t,s);
1725 }
1726 if (result && t.hasTag(CLASS) && t.tsym.kind.matches(Kinds.KindSelector.TYP)
1727 && s.hasTag(CLASS) && s.tsym.kind.matches(Kinds.KindSelector.TYP)
1728 && (t.tsym.isSealed() || s.tsym.isSealed())) {
1729 return (t.isCompound() || s.isCompound()) ?
1730 true :
1731 !areDisjoint((ClassSymbol)t.tsym, (ClassSymbol)s.tsym);
1732 }
1733 return result;
1734 }
1735 // where
1736 private boolean areDisjoint(ClassSymbol ts, ClassSymbol ss) {
1737 if (isSubtype(erasure(ts.type.referenceProjectionOrSelf()), erasure(ss.type))) {
1738 return false;
1739 }
1740 // if both are classes or both are interfaces, shortcut
1741 if (ts.isInterface() == ss.isInterface() && isSubtype(erasure(ss.type), erasure(ts.type))) {
1742 return false;
1743 }
1744 if (ts.isInterface() && !ss.isInterface()) {
1745 /* so ts is interface but ss is a class
1746 * an interface is disjoint from a class if the class is disjoint form the interface
1747 */
1748 return areDisjoint(ss, ts);
1749 }
1750 // a final class that is not subtype of ss is disjoint
1751 if (!ts.isInterface() && ts.isFinal()) {
1752 return true;
1753 }
1754 // if at least one is sealed
1755 if (ts.isSealed() || ss.isSealed()) {
1756 // permitted subtypes have to be disjoint with the other symbol
1757 ClassSymbol sealedOne = ts.isSealed() ? ts : ss;
1758 ClassSymbol other = sealedOne == ts ? ss : ts;
1759 return sealedOne.permitted.stream().allMatch(sym -> areDisjoint((ClassSymbol)sym, other));
1760 }
1761 return false;
1762 }
1763
1764 private TypeRelation isCastable = new TypeRelation() {
1765
1766 public Boolean visitType(Type t, Type s) {
1767 if (s.hasTag(ERROR) || t.hasTag(NONE))
1768 return true;
1769
1770 switch (t.getTag()) {
1771 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1772 case DOUBLE:
1773 return s.isNumeric();
1774 case BOOLEAN:
1775 return s.hasTag(BOOLEAN);
1776 case VOID:
1777 return false;
1778 case BOT:
1779 return isSubtype(t, s);
1780 default:
1781 throw new AssertionError();
1782 }
1783 }
1784
1785 @Override
1786 public Boolean visitWildcardType(WildcardType t, Type s) {
1787 return isCastable(wildUpperBound(t), s, warnStack.head);
1788 }
1789
1790 @Override
1791 public Boolean visitClassType(ClassType t, Type s) {
1792 if (s.hasTag(ERROR) || (s.hasTag(BOT) && !t.isPrimitiveClass()))
1793 return true;
1794
1795 if (s.hasTag(TYPEVAR)) {
1796 if (isCastable(t, s.getUpperBound(), noWarnings)) {
1797 warnStack.head.warn(LintCategory.UNCHECKED);
1798 return true;
1799 } else {
1800 return false;
1801 }
1802 }
1803
1804 if (t.isCompound() || s.isCompound()) {
1805 return !t.isCompound() ?
1806 visitCompoundType((ClassType)s, t, true) :
1807 visitCompoundType(t, s, false);
1808 }
1809
1810 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) {
1811 if (t.isPrimitiveClass()) {
1812 // (s) Value ? == (s) Value.ref
1813 t = t.referenceProjection();
1814 }
1815 if (s.isPrimitiveClass()) {
1816 // (Value) t ? == (Value.ref) t
1817 s = s.referenceProjection();
1818 }
1819 boolean upcast;
1820 if ((upcast = isSubtype(erasure(t), erasure(s)))
1821 || isSubtype(erasure(s), erasure(t))) {
1822 if (!upcast && s.hasTag(ARRAY)) {
1823 if (!isReifiable(s))
1824 warnStack.head.warn(LintCategory.UNCHECKED);
1825 return true;
1826 } else if (s.isRaw()) {
1827 return true;
1828 } else if (t.isRaw()) {
1829 if (!isUnbounded(s))
1830 warnStack.head.warn(LintCategory.UNCHECKED);
1831 return true;
1832 }
1833 // Assume |a| <: |b|
1834 final Type a = upcast ? t : s;
1835 final Type b = upcast ? s : t;
1836 final boolean HIGH = true;
1837 final boolean LOW = false;
1838 final boolean DONT_REWRITE_TYPEVARS = false;
1839 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS);
1840 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS);
1841 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS);
1842 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS);
1843 Type lowSub = asSub(bLow, aLow.tsym);
1844 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1845 if (highSub == null) {
1846 final boolean REWRITE_TYPEVARS = true;
1847 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS);
1848 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS);
1849 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS);
1850 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS);
1851 lowSub = asSub(bLow, aLow.tsym);
1852 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1853 }
1854 if (highSub != null) {
1855 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) {
1856 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym);
1857 }
1858 if (!disjointTypes(aHigh.allparams(), highSub.allparams())
1859 && !disjointTypes(aHigh.allparams(), lowSub.allparams())
1860 && !disjointTypes(aLow.allparams(), highSub.allparams())
1861 && !disjointTypes(aLow.allparams(), lowSub.allparams())) {
1862 if (upcast ? giveWarning(a, b) :
1863 giveWarning(b, a))
1864 warnStack.head.warn(LintCategory.UNCHECKED);
1865 return true;
1866 }
1867 }
1868 if (isReifiable(s))
1869 return isSubtypeUnchecked(a, b);
1870 else
1871 return isSubtypeUnchecked(a, b, warnStack.head);
1872 }
1873
1874 // Sidecast
1875 if (s.hasTag(CLASS)) {
1876 if ((s.tsym.flags() & INTERFACE) != 0) {
1877 return ((t.tsym.flags() & FINAL) == 0)
1878 ? sideCast(t, s, warnStack.head)
1879 : sideCastFinal(t, s, warnStack.head);
1880 } else if ((t.tsym.flags() & INTERFACE) != 0) {
1881 return ((s.tsym.flags() & FINAL) == 0)
1882 ? sideCast(t, s, warnStack.head)
1883 : sideCastFinal(t, s, warnStack.head);
1884 } else {
1885 // unrelated class types
1886 return false;
1887 }
1888 }
1889 }
1890 return false;
1891 }
1892
1893 boolean visitCompoundType(ClassType ct, Type s, boolean reverse) {
1894 Warner warn = noWarnings;
1895 for (Type c : directSupertypes(ct)) {
1896 warn.clear();
1897 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn))
1898 return false;
1899 }
1900 if (warn.hasLint(LintCategory.UNCHECKED))
1901 warnStack.head.warn(LintCategory.UNCHECKED);
1902 return true;
1903 }
1904
1905 @Override
1906 public Boolean visitArrayType(ArrayType t, Type s) {
1907 switch (s.getTag()) {
1908 case ERROR:
1909 case BOT:
1910 return true;
1911 case TYPEVAR:
1912 if (isCastable(s, t, noWarnings)) {
1913 warnStack.head.warn(LintCategory.UNCHECKED);
1914 return true;
1915 } else {
1916 return false;
1917 }
1918 case CLASS:
1919 return isSubtype(t, s);
1920 case ARRAY:
1921 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) {
1922 return elemtype(t).hasTag(elemtype(s).getTag());
1923 } else {
1924 Type et = elemtype(t);
1925 Type es = elemtype(s);
1926 if (!visit(et, es))
1927 return false;
1928 return true;
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 (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 (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() != TypeMetadata.EMPTY) {
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.cloneWithMetadata(s.getMetadata().without(Kind.ANNOTATIONS));
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.getMetadata().without(Kind.ANNOTATIONS));
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 long flags = ABSTRACT | PUBLIC | SYNTHETIC | COMPOUND | ACYCLIC;
2626 ClassSymbol bc =
2627 new ClassSymbol(flags,
2628 Type.moreInfo
2629 ? names.fromString(bounds.toString())
2630 : names.empty,
2631 null,
2632 syms.noSymbol);
2633 IntersectionClassType intersectionType = new IntersectionClassType(bounds, bc, allInterfaces);
2634 bc.type = intersectionType;
2635 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ?
2636 syms.objectType : // error condition, recover
2637 erasure(firstExplicitBound);
2638 bc.members_field = WriteableScope.create(bc);
2639 return intersectionType;
2640 }
2641 // </editor-fold>
2642
2643 // <editor-fold defaultstate="collapsed" desc="supertype">
2644 public Type supertype(Type t) {
2645 return supertype.visit(t);
2646 }
2647 // where
2648 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() {
2649
2650 public Type visitType(Type t, Void ignored) {
2651 // A note on wildcards: there is no good way to
2652 // determine a supertype for a lower-bounded wildcard.
2653 return Type.noType;
2654 }
2655
2656 @Override
2657 public Type visitClassType(ClassType t, Void ignored) {
2658 if (t.supertype_field == null) {
2659 Type supertype = ((ClassSymbol)t.tsym).getSuperclass();
2660 // An interface has no superclass; its supertype is Object.
2661 if (t.isInterface())
2662 supertype = ((ClassType)t.tsym.type).supertype_field;
2663 if (t.supertype_field == null) {
2664 List<Type> actuals = classBound(t).allparams();
2665 List<Type> formals = t.tsym.type.allparams();
2666 if (t.hasErasedSupertypes()) {
2667 t.supertype_field = erasureRecursive(supertype);
2668 } else if (formals.nonEmpty()) {
2669 t.supertype_field = subst(supertype, formals, actuals);
2670 }
2671 else {
2672 t.supertype_field = supertype;
2673 }
2674 }
2675 }
2676 return t.supertype_field;
2677 }
2678
2679 /**
2680 * The supertype is always a class type. If the type
2681 * variable's bounds start with a class type, this is also
2682 * the supertype. Otherwise, the supertype is
2683 * java.lang.Object.
2684 */
2685 @Override
2686 public Type visitTypeVar(TypeVar t, Void ignored) {
2687 if (t.getUpperBound().hasTag(TYPEVAR) ||
2688 (!t.getUpperBound().isCompound() && !t.getUpperBound().isInterface())) {
2689 return t.getUpperBound();
2690 } else {
2691 return supertype(t.getUpperBound());
2692 }
2693 }
2694
2695 @Override
2696 public Type visitArrayType(ArrayType t, Void ignored) {
2697 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType))
2698 return arraySuperType();
2699 else
2700 return new ArrayType(supertype(t.elemtype), t.tsym);
2701 }
2702
2703 @Override
2704 public Type visitErrorType(ErrorType t, Void ignored) {
2705 return Type.noType;
2706 }
2707 };
2708 // </editor-fold>
2709
2710 // <editor-fold defaultstate="collapsed" desc="interfaces">
2711 /**
2712 * Return the interfaces implemented by this class.
2713 */
2714 public List<Type> interfaces(Type t) {
2715 return interfaces.visit(t);
2716 }
2717 // where
2718 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() {
2719
2720 public List<Type> visitType(Type t, Void ignored) {
2721 return List.nil();
2722 }
2723
2724 @Override
2725 public List<Type> visitClassType(ClassType t, Void ignored) {
2726 if (t.interfaces_field == null) {
2727 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces();
2728 if (t.interfaces_field == null) {
2729 // If t.interfaces_field is null, then t must
2730 // be a parameterized type (not to be confused
2731 // with a generic type declaration).
2732 // Terminology:
2733 // Parameterized type: List<String>
2734 // Generic type declaration: class List<E> { ... }
2735 // So t corresponds to List<String> and
2736 // t.tsym.type corresponds to List<E>.
2737 // The reason t must be parameterized type is
2738 // that completion will happen as a side
2739 // effect of calling
2740 // ClassSymbol.getInterfaces. Since
2741 // t.interfaces_field is null after
2742 // completion, we can assume that t is not the
2743 // type of a class/interface declaration.
2744 Assert.check(t != t.tsym.type, t);
2745 List<Type> actuals = t.allparams();
2746 List<Type> formals = t.tsym.type.allparams();
2747 if (t.hasErasedSupertypes()) {
2748 t.interfaces_field = erasureRecursive(interfaces);
2749 } else if (formals.nonEmpty()) {
2750 t.interfaces_field = subst(interfaces, formals, actuals);
2751 }
2752 else {
2753 t.interfaces_field = interfaces;
2754 }
2755 }
2756 }
2757 return t.interfaces_field;
2758 }
2759
2760 @Override
2761 public List<Type> visitTypeVar(TypeVar t, Void ignored) {
2762 if (t.getUpperBound().isCompound())
2763 return interfaces(t.getUpperBound());
2764
2765 if (t.getUpperBound().isInterface())
2766 return List.of(t.getUpperBound());
2767
2768 return List.nil();
2769 }
2770 };
2771
2772 public List<Type> directSupertypes(Type t) {
2773 return directSupertypes.visit(t);
2774 }
2775 // where
2776 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() {
2777
2778 public List<Type> visitType(final Type type, final Void ignored) {
2779 if (!type.isIntersection()) {
2780 final Type sup = supertype(type);
2781 return (sup == Type.noType || sup == type || sup == null)
2782 ? interfaces(type)
2783 : interfaces(type).prepend(sup);
2784 } else {
2785 return ((IntersectionClassType)type).getExplicitComponents();
2786 }
2787 }
2788 };
2789
2790 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) {
2791 for (Type i2 : interfaces(origin.type)) {
2792 if (isym == i2.tsym) return true;
2793 }
2794 return false;
2795 }
2796 // </editor-fold>
2797
2798 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw">
2799 Map<Type,Boolean> isDerivedRawCache = new HashMap<>();
2800
2801 public boolean isDerivedRaw(Type t) {
2802 Boolean result = isDerivedRawCache.get(t);
2803 if (result == null) {
2804 result = isDerivedRawInternal(t);
2805 isDerivedRawCache.put(t, result);
2806 }
2807 return result;
2808 }
2809
2810 public boolean isDerivedRawInternal(Type t) {
2811 if (t.isErroneous())
2812 return false;
2813 return
2814 t.isRaw() ||
2815 supertype(t) != Type.noType && isDerivedRaw(supertype(t)) ||
2816 isDerivedRaw(interfaces(t));
2817 }
2818
2819 public boolean isDerivedRaw(List<Type> ts) {
2820 List<Type> l = ts;
2821 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail;
2822 return l.nonEmpty();
2823 }
2824 // </editor-fold>
2825
2826 // <editor-fold defaultstate="collapsed" desc="setBounds">
2827 /**
2828 * Same as {@link Types#setBounds(TypeVar, List, boolean)}, except that third parameter is computed directly,
2829 * as follows: if all all bounds are interface types, the computed supertype is Object,otherwise
2830 * the supertype is simply left null (in this case, the supertype is assumed to be the head of
2831 * the bound list passed as second argument). Note that this check might cause a symbol completion.
2832 * Hence, this version of setBounds may not be called during a classfile read.
2833 *
2834 * @param t a type variable
2835 * @param bounds the bounds, must be nonempty
2836 */
2837 public void setBounds(TypeVar t, List<Type> bounds) {
2838 setBounds(t, bounds, bounds.head.tsym.isInterface());
2839 }
2840
2841 /**
2842 * Set the bounds field of the given type variable to reflect a (possibly multiple) list of bounds.
2843 * This does not cause symbol completion as an extra parameter indicates as to whether all bounds
2844 * are interfaces - in which case the supertype is implicitly assumed to be 'Object'.
2845 *
2846 * @param t a type variable
2847 * @param bounds the bounds, must be nonempty
2848 * @param allInterfaces are all bounds interface types?
2849 */
2850 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) {
2851 t.setUpperBound( bounds.tail.isEmpty() ?
2852 bounds.head :
2853 makeIntersectionType(bounds, allInterfaces) );
2854 t.rank_field = -1;
2855 }
2856 // </editor-fold>
2857
2858 // <editor-fold defaultstate="collapsed" desc="getBounds">
2859 /**
2860 * Return list of bounds of the given type variable.
2861 */
2862 public List<Type> getBounds(TypeVar t) {
2863 if (t.getUpperBound().hasTag(NONE))
2864 return List.nil();
2865 else if (t.getUpperBound().isErroneous() || !t.getUpperBound().isCompound())
2866 return List.of(t.getUpperBound());
2867 else if ((erasure(t).tsym.flags() & INTERFACE) == 0)
2868 return interfaces(t).prepend(supertype(t));
2869 else
2870 // No superclass was given in bounds.
2871 // In this case, supertype is Object, erasure is first interface.
2872 return interfaces(t);
2873 }
2874 // </editor-fold>
2875
2876 // <editor-fold defaultstate="collapsed" desc="classBound">
2877 /**
2878 * If the given type is a (possibly selected) type variable,
2879 * return the bounding class of this type, otherwise return the
2880 * type itself.
2881 */
2882 public Type classBound(Type t) {
2883 return classBound.visit(t);
2884 }
2885 // where
2886 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() {
2887
2888 public Type visitType(Type t, Void ignored) {
2889 return t;
2890 }
2891
2892 @Override
2893 public Type visitClassType(ClassType t, Void ignored) {
2894 Type outer1 = classBound(t.getEnclosingType());
2895 if (outer1 != t.getEnclosingType())
2896 return new ClassType(outer1, t.getTypeArguments(), t.tsym,
2897 t.getMetadata(), t.getFlavor());
2898 else
2899 return t;
2900 }
2901
2902 @Override
2903 public Type visitTypeVar(TypeVar t, Void ignored) {
2904 return classBound(supertype(t));
2905 }
2906
2907 @Override
2908 public Type visitErrorType(ErrorType t, Void ignored) {
2909 return t;
2910 }
2911 };
2912 // </editor-fold>
2913
2914 // <editor-fold defaultstate="collapsed" desc="subsignature / override equivalence">
2915 /**
2916 * Returns true iff the first signature is a <em>subsignature</em>
2917 * of the other. This is <b>not</b> an equivalence
2918 * relation.
2919 *
2920 * @jls 8.4.2 Method Signature
2921 * @see #overrideEquivalent(Type t, Type s)
2922 * @param t first signature (possibly raw).
2923 * @param s second signature (could be subjected to erasure).
2924 * @return true if t is a subsignature of s.
2925 */
2926 public boolean isSubSignature(Type t, Type s) {
2927 return hasSameArgs(t, s, true) || hasSameArgs(t, erasure(s), true);
2928 }
2929
2930 /**
2931 * Returns true iff these signatures are related by <em>override
2932 * equivalence</em>. This is the natural extension of
2933 * isSubSignature to an equivalence relation.
2934 *
2935 * @jls 8.4.2 Method Signature
2936 * @see #isSubSignature(Type t, Type s)
2937 * @param t a signature (possible raw, could be subjected to
2938 * erasure).
2939 * @param s a signature (possible raw, could be subjected to
2940 * erasure).
2941 * @return true if either argument is a subsignature of the other.
2942 */
2943 public boolean overrideEquivalent(Type t, Type s) {
2944 return hasSameArgs(t, s) ||
2945 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s);
2946 }
2947
2948 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) {
2949 for (Symbol sym : syms.objectType.tsym.members().getSymbolsByName(msym.name)) {
2950 if (msym.overrides(sym, origin, Types.this, true)) {
2951 return true;
2952 }
2953 }
2954 return false;
2955 }
2956
2957 /**
2958 * This enum defines the strategy for implementing most specific return type check
2959 * during the most specific and functional interface checks.
2960 */
2961 public enum MostSpecificReturnCheck {
2962 /**
2963 * Return r1 is more specific than r2 if {@code r1 <: r2}. Extra care required for (i) handling
2964 * method type variables (if either method is generic) and (ii) subtyping should be replaced
2965 * by type-equivalence for primitives. This is essentially an inlined version of
2966 * {@link Types#resultSubtype(Type, Type, Warner)}, where the assignability check has been
2967 * replaced with a strict subtyping check.
2968 */
2969 BASIC() {
2970 @Override
2971 public boolean test(Type mt1, Type mt2, Types types) {
2972 List<Type> tvars = mt1.getTypeArguments();
2973 List<Type> svars = mt2.getTypeArguments();
2974 Type t = mt1.getReturnType();
2975 Type s = types.subst(mt2.getReturnType(), svars, tvars);
2976 return types.isSameType(t, s) ||
2977 !t.isPrimitive() &&
2978 !s.isPrimitive() &&
2979 types.isSubtype(t, s);
2980 }
2981 },
2982 /**
2983 * Return r1 is more specific than r2 if r1 is return-type-substitutable for r2.
2984 */
2985 RTS() {
2986 @Override
2987 public boolean test(Type mt1, Type mt2, Types types) {
2988 return types.returnTypeSubstitutable(mt1, mt2);
2989 }
2990 };
2991
2992 public abstract boolean test(Type mt1, Type mt2, Types types);
2993 }
2994
2995 /**
2996 * Merge multiple abstract methods. The preferred method is a method that is a subsignature
2997 * of all the other signatures and whose return type is more specific {@see MostSpecificReturnCheck}.
2998 * The resulting preferred method has a thrown clause that is the intersection of the merged
2999 * methods' clauses.
3000 */
3001 public Optional<Symbol> mergeAbstracts(List<Symbol> ambiguousInOrder, Type site, boolean sigCheck) {
3002 //first check for preconditions
3003 boolean shouldErase = false;
3004 List<Type> erasedParams = ambiguousInOrder.head.erasure(this).getParameterTypes();
3005 for (Symbol s : ambiguousInOrder) {
3006 if ((s.flags() & ABSTRACT) == 0 ||
3007 (sigCheck && !isSameTypes(erasedParams, s.erasure(this).getParameterTypes()))) {
3008 return Optional.empty();
3009 } else if (s.type.hasTag(FORALL)) {
3010 shouldErase = true;
3011 }
3012 }
3013 //then merge abstracts
3014 for (MostSpecificReturnCheck mostSpecificReturnCheck : MostSpecificReturnCheck.values()) {
3015 outer: for (Symbol s : ambiguousInOrder) {
3016 Type mt = memberType(site, s);
3017 List<Type> allThrown = mt.getThrownTypes();
3018 for (Symbol s2 : ambiguousInOrder) {
3019 if (s != s2) {
3020 Type mt2 = memberType(site, s2);
3021 if (!isSubSignature(mt, mt2) ||
3022 !mostSpecificReturnCheck.test(mt, mt2, this)) {
3023 //ambiguity cannot be resolved
3024 continue outer;
3025 } else {
3026 List<Type> thrownTypes2 = mt2.getThrownTypes();
3027 if (!mt.hasTag(FORALL) && shouldErase) {
3028 thrownTypes2 = erasure(thrownTypes2);
3029 } else if (mt.hasTag(FORALL)) {
3030 //subsignature implies that if most specific is generic, then all other
3031 //methods are too
3032 Assert.check(mt2.hasTag(FORALL));
3033 // if both are generic methods, adjust thrown types ahead of intersection computation
3034 thrownTypes2 = subst(thrownTypes2, mt2.getTypeArguments(), mt.getTypeArguments());
3035 }
3036 allThrown = chk.intersect(allThrown, thrownTypes2);
3037 }
3038 }
3039 }
3040 return (allThrown == mt.getThrownTypes()) ?
3041 Optional.of(s) :
3042 Optional.of(new MethodSymbol(
3043 s.flags(),
3044 s.name,
3045 createMethodTypeWithThrown(s.type, allThrown),
3046 s.owner) {
3047 @Override
3048 public Symbol baseSymbol() {
3049 return s;
3050 }
3051 });
3052 }
3053 }
3054 return Optional.empty();
3055 }
3056
3057 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site">
3058 class ImplementationCache {
3059
3060 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map = new WeakHashMap<>();
3061
3062 class Entry {
3063 final MethodSymbol cachedImpl;
3064 final Predicate<Symbol> implFilter;
3065 final boolean checkResult;
3066 final int prevMark;
3067
3068 public Entry(MethodSymbol cachedImpl,
3069 Predicate<Symbol> scopeFilter,
3070 boolean checkResult,
3071 int prevMark) {
3072 this.cachedImpl = cachedImpl;
3073 this.implFilter = scopeFilter;
3074 this.checkResult = checkResult;
3075 this.prevMark = prevMark;
3076 }
3077
3078 boolean matches(Predicate<Symbol> scopeFilter, boolean checkResult, int mark) {
3079 return this.implFilter == scopeFilter &&
3080 this.checkResult == checkResult &&
3081 this.prevMark == mark;
3082 }
3083 }
3084
3085 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3086 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms);
3087 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null;
3088 if (cache == null) {
3089 cache = new HashMap<>();
3090 _map.put(ms, new SoftReference<>(cache));
3091 }
3092 Entry e = cache.get(origin);
3093 CompoundScope members = membersClosure(origin.type, true);
3094 if (e == null ||
3095 !e.matches(implFilter, checkResult, members.getMark())) {
3096 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter);
3097 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark()));
3098 return impl;
3099 }
3100 else {
3101 return e.cachedImpl;
3102 }
3103 }
3104
3105 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3106 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) {
3107 t = skipTypeVars(t, false);
3108 TypeSymbol c = t.tsym;
3109 Symbol bestSoFar = null;
3110 for (Symbol sym : c.members().getSymbolsByName(ms.name, implFilter)) {
3111 if (sym != null && sym.overrides(ms, origin, Types.this, checkResult)) {
3112 bestSoFar = sym;
3113 if ((sym.flags() & ABSTRACT) == 0) {
3114 //if concrete impl is found, exit immediately
3115 break;
3116 }
3117 }
3118 }
3119 if (bestSoFar != null) {
3120 //return either the (only) concrete implementation or the first abstract one
3121 return (MethodSymbol)bestSoFar;
3122 }
3123 }
3124 return null;
3125 }
3126 }
3127
3128 private ImplementationCache implCache = new ImplementationCache();
3129
3130 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3131 return implCache.get(ms, origin, checkResult, implFilter);
3132 }
3133 // </editor-fold>
3134
3135 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site">
3136 class MembersClosureCache extends SimpleVisitor<Scope.CompoundScope, Void> {
3137
3138 private Map<TypeSymbol, CompoundScope> _map = new HashMap<>();
3139
3140 Set<TypeSymbol> seenTypes = new HashSet<>();
3141
3142 class MembersScope extends CompoundScope {
3143
3144 CompoundScope scope;
3145
3146 public MembersScope(CompoundScope scope) {
3147 super(scope.owner);
3148 this.scope = scope;
3149 }
3150
3151 Predicate<Symbol> combine(Predicate<Symbol> sf) {
3152 return s -> !s.owner.isInterface() && (sf == null || sf.test(s));
3153 }
3154
3155 @Override
3156 public Iterable<Symbol> getSymbols(Predicate<Symbol> sf, LookupKind lookupKind) {
3157 return scope.getSymbols(combine(sf), lookupKind);
3158 }
3159
3160 @Override
3161 public Iterable<Symbol> getSymbolsByName(Name name, Predicate<Symbol> sf, LookupKind lookupKind) {
3162 return scope.getSymbolsByName(name, combine(sf), lookupKind);
3163 }
3164
3165 @Override
3166 public int getMark() {
3167 return scope.getMark();
3168 }
3169 }
3170
3171 CompoundScope nilScope;
3172
3173 /** members closure visitor methods **/
3174
3175 public CompoundScope visitType(Type t, Void _unused) {
3176 if (nilScope == null) {
3177 nilScope = new CompoundScope(syms.noSymbol);
3178 }
3179 return nilScope;
3180 }
3181
3182 @Override
3183 public CompoundScope visitClassType(ClassType t, Void _unused) {
3184 if (!seenTypes.add(t.tsym)) {
3185 //this is possible when an interface is implemented in multiple
3186 //superclasses, or when a class hierarchy is circular - in such
3187 //cases we don't need to recurse (empty scope is returned)
3188 return new CompoundScope(t.tsym);
3189 }
3190 try {
3191 seenTypes.add(t.tsym);
3192 ClassSymbol csym = (ClassSymbol)t.tsym;
3193 CompoundScope membersClosure = _map.get(csym);
3194 if (membersClosure == null) {
3195 membersClosure = new CompoundScope(csym);
3196 for (Type i : interfaces(t)) {
3197 membersClosure.prependSubScope(visit(i, null));
3198 }
3199 membersClosure.prependSubScope(visit(supertype(t), null));
3200 membersClosure.prependSubScope(csym.members());
3201 _map.put(csym, membersClosure);
3202 }
3203 return membersClosure;
3204 }
3205 finally {
3206 seenTypes.remove(t.tsym);
3207 }
3208 }
3209
3210 @Override
3211 public CompoundScope visitTypeVar(TypeVar t, Void _unused) {
3212 return visit(t.getUpperBound(), null);
3213 }
3214 }
3215
3216 private MembersClosureCache membersCache = new MembersClosureCache();
3217
3218 public CompoundScope membersClosure(Type site, boolean skipInterface) {
3219 CompoundScope cs = membersCache.visit(site, null);
3220 Assert.checkNonNull(cs, () -> "type " + site);
3221 return skipInterface ? membersCache.new MembersScope(cs) : cs;
3222 }
3223 // </editor-fold>
3224
3225
3226 /** Return first abstract member of class `sym'.
3227 */
3228 public MethodSymbol firstUnimplementedAbstract(ClassSymbol sym) {
3229 try {
3230 return firstUnimplementedAbstractImpl(sym, sym);
3231 } catch (CompletionFailure ex) {
3232 chk.completionError(enter.getEnv(sym).tree.pos(), ex);
3233 return null;
3234 }
3235 }
3236 //where:
3237 private MethodSymbol firstUnimplementedAbstractImpl(ClassSymbol impl, ClassSymbol c) {
3238 MethodSymbol undef = null;
3239 // Do not bother to search in classes that are not abstract,
3240 // since they cannot have abstract members.
3241 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
3242 Scope s = c.members();
3243 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) {
3244 if (sym.kind == MTH &&
3245 (sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
3246 MethodSymbol absmeth = (MethodSymbol)sym;
3247 MethodSymbol implmeth = absmeth.implementation(impl, this, true);
3248 if (implmeth == null || implmeth == absmeth) {
3249 //look for default implementations
3250 MethodSymbol prov = interfaceCandidates(impl.type, absmeth).head;
3251 if (prov != null && prov.overrides(absmeth, impl, this, true)) {
3252 implmeth = prov;
3253 }
3254 }
3255 if (implmeth == null || implmeth == absmeth) {
3256 undef = absmeth;
3257 break;
3258 }
3259 }
3260 }
3261 if (undef == null) {
3262 Type st = supertype(c.type);
3263 if (st.hasTag(CLASS))
3264 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)st.tsym);
3265 }
3266 for (List<Type> l = interfaces(c.type);
3267 undef == null && l.nonEmpty();
3268 l = l.tail) {
3269 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)l.head.tsym);
3270 }
3271 }
3272 return undef;
3273 }
3274
3275 public class CandidatesCache {
3276 public Map<Entry, List<MethodSymbol>> cache = new WeakHashMap<>();
3277
3278 class Entry {
3279 Type site;
3280 MethodSymbol msym;
3281
3282 Entry(Type site, MethodSymbol msym) {
3283 this.site = site;
3284 this.msym = msym;
3285 }
3286
3287 @Override
3288 public boolean equals(Object obj) {
3289 return (obj instanceof Entry entry)
3290 && entry.msym == msym
3291 && isSameType(site, entry.site);
3292 }
3293
3294 @Override
3295 public int hashCode() {
3296 return Types.this.hashCode(site) & ~msym.hashCode();
3297 }
3298 }
3299
3300 public List<MethodSymbol> get(Entry e) {
3301 return cache.get(e);
3302 }
3303
3304 public void put(Entry e, List<MethodSymbol> msymbols) {
3305 cache.put(e, msymbols);
3306 }
3307 }
3308
3309 public CandidatesCache candidatesCache = new CandidatesCache();
3310
3311 //where
3312 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) {
3313 CandidatesCache.Entry e = candidatesCache.new Entry(site, ms);
3314 List<MethodSymbol> candidates = candidatesCache.get(e);
3315 if (candidates == null) {
3316 Predicate<Symbol> filter = new MethodFilter(ms, site);
3317 List<MethodSymbol> candidates2 = List.nil();
3318 for (Symbol s : membersClosure(site, false).getSymbols(filter)) {
3319 if (!site.tsym.isInterface() && !s.owner.isInterface()) {
3320 return List.of((MethodSymbol)s);
3321 } else if (!candidates2.contains(s)) {
3322 candidates2 = candidates2.prepend((MethodSymbol)s);
3323 }
3324 }
3325 candidates = prune(candidates2);
3326 candidatesCache.put(e, candidates);
3327 }
3328 return candidates;
3329 }
3330
3331 public List<MethodSymbol> prune(List<MethodSymbol> methods) {
3332 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>();
3333 for (MethodSymbol m1 : methods) {
3334 boolean isMin_m1 = true;
3335 for (MethodSymbol m2 : methods) {
3336 if (m1 == m2) continue;
3337 if (m2.owner != m1.owner &&
3338 asSuper(m2.owner.type, m1.owner) != null) {
3339 isMin_m1 = false;
3340 break;
3341 }
3342 }
3343 if (isMin_m1)
3344 methodsMin.append(m1);
3345 }
3346 return methodsMin.toList();
3347 }
3348 // where
3349 private class MethodFilter implements Predicate<Symbol> {
3350
3351 Symbol msym;
3352 Type site;
3353
3354 MethodFilter(Symbol msym, Type site) {
3355 this.msym = msym;
3356 this.site = site;
3357 }
3358
3359 @Override
3360 public boolean test(Symbol s) {
3361 return s.kind == MTH &&
3362 s.name == msym.name &&
3363 (s.flags() & SYNTHETIC) == 0 &&
3364 s.isInheritedIn(site.tsym, Types.this) &&
3365 overrideEquivalent(memberType(site, s), memberType(site, msym));
3366 }
3367 }
3368 // </editor-fold>
3369
3370 /**
3371 * Does t have the same arguments as s? It is assumed that both
3372 * types are (possibly polymorphic) method types. Monomorphic
3373 * method types "have the same arguments", if their argument lists
3374 * are equal. Polymorphic method types "have the same arguments",
3375 * if they have the same arguments after renaming all type
3376 * variables of one to corresponding type variables in the other,
3377 * where correspondence is by position in the type parameter list.
3378 */
3379 public boolean hasSameArgs(Type t, Type s) {
3380 return hasSameArgs(t, s, true);
3381 }
3382
3383 public boolean hasSameArgs(Type t, Type s, boolean strict) {
3384 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict);
3385 }
3386
3387 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) {
3388 return hasSameArgs.visit(t, s);
3389 }
3390 // where
3391 private class HasSameArgs extends TypeRelation {
3392
3393 boolean strict;
3394
3395 public HasSameArgs(boolean strict) {
3396 this.strict = strict;
3397 }
3398
3399 public Boolean visitType(Type t, Type s) {
3400 throw new AssertionError();
3401 }
3402
3403 @Override
3404 public Boolean visitMethodType(MethodType t, Type s) {
3405 return s.hasTag(METHOD)
3406 && containsTypeEquivalent(t.argtypes, s.getParameterTypes());
3407 }
3408
3409 @Override
3410 public Boolean visitForAll(ForAll t, Type s) {
3411 if (!s.hasTag(FORALL))
3412 return strict ? false : visitMethodType(t.asMethodType(), s);
3413
3414 ForAll forAll = (ForAll)s;
3415 return hasSameBounds(t, forAll)
3416 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
3417 }
3418
3419 @Override
3420 public Boolean visitErrorType(ErrorType t, Type s) {
3421 return false;
3422 }
3423 }
3424
3425 TypeRelation hasSameArgs_strict = new HasSameArgs(true);
3426 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false);
3427
3428 // </editor-fold>
3429
3430 // <editor-fold defaultstate="collapsed" desc="subst">
3431 public List<Type> subst(List<Type> ts,
3432 List<Type> from,
3433 List<Type> to) {
3434 return ts.map(new Subst(from, to));
3435 }
3436
3437 /**
3438 * Substitute all occurrences of a type in `from' with the
3439 * corresponding type in `to' in 't'. Match lists `from' and `to'
3440 * from the right: If lists have different length, discard leading
3441 * elements of the longer list.
3442 */
3443 public Type subst(Type t, List<Type> from, List<Type> to) {
3444 return t.map(new Subst(from, to));
3445 }
3446
3447 private class Subst extends StructuralTypeMapping<Void> {
3448 List<Type> from;
3449 List<Type> to;
3450
3451 public Subst(List<Type> from, List<Type> to) {
3452 int fromLength = from.length();
3453 int toLength = to.length();
3454 while (fromLength > toLength) {
3455 fromLength--;
3456 from = from.tail;
3457 }
3458 while (fromLength < toLength) {
3459 toLength--;
3460 to = to.tail;
3461 }
3462 this.from = from;
3463 this.to = to;
3464 }
3465
3466 @Override
3467 public Type visitTypeVar(TypeVar t, Void ignored) {
3468 for (List<Type> from = this.from, to = this.to;
3469 from.nonEmpty();
3470 from = from.tail, to = to.tail) {
3471 if (t.equalsIgnoreMetadata(from.head)) {
3472 return to.head.withTypeVar(t);
3473 }
3474 }
3475 return t;
3476 }
3477
3478 @Override
3479 public Type visitClassType(ClassType t, Void ignored) {
3480 if (!t.isCompound()) {
3481 return super.visitClassType(t, ignored);
3482 } else {
3483 Type st = visit(supertype(t));
3484 List<Type> is = visit(interfaces(t), ignored);
3485 if (st == supertype(t) && is == interfaces(t))
3486 return t;
3487 else
3488 return makeIntersectionType(is.prepend(st));
3489 }
3490 }
3491
3492 @Override
3493 public Type visitWildcardType(WildcardType t, Void ignored) {
3494 WildcardType t2 = (WildcardType)super.visitWildcardType(t, ignored);
3495 if (t2 != t && t.isExtendsBound() && t2.type.isExtendsBound()) {
3496 t2.type = wildUpperBound(t2.type);
3497 }
3498 return t2;
3499 }
3500
3501 @Override
3502 public Type visitForAll(ForAll t, Void ignored) {
3503 if (Type.containsAny(to, t.tvars)) {
3504 //perform alpha-renaming of free-variables in 't'
3505 //if 'to' types contain variables that are free in 't'
3506 List<Type> freevars = newInstances(t.tvars);
3507 t = new ForAll(freevars,
3508 Types.this.subst(t.qtype, t.tvars, freevars));
3509 }
3510 List<Type> tvars1 = substBounds(t.tvars, from, to);
3511 Type qtype1 = visit(t.qtype);
3512 if (tvars1 == t.tvars && qtype1 == t.qtype) {
3513 return t;
3514 } else if (tvars1 == t.tvars) {
3515 return new ForAll(tvars1, qtype1) {
3516 @Override
3517 public boolean needsStripping() {
3518 return true;
3519 }
3520 };
3521 } else {
3522 return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1)) {
3523 @Override
3524 public boolean needsStripping() {
3525 return true;
3526 }
3527 };
3528 }
3529 }
3530 }
3531
3532 public List<Type> substBounds(List<Type> tvars,
3533 List<Type> from,
3534 List<Type> to) {
3535 if (tvars.isEmpty())
3536 return tvars;
3537 ListBuffer<Type> newBoundsBuf = new ListBuffer<>();
3538 boolean changed = false;
3539 // calculate new bounds
3540 for (Type t : tvars) {
3541 TypeVar tv = (TypeVar) t;
3542 Type bound = subst(tv.getUpperBound(), from, to);
3543 if (bound != tv.getUpperBound())
3544 changed = true;
3545 newBoundsBuf.append(bound);
3546 }
3547 if (!changed)
3548 return tvars;
3549 ListBuffer<Type> newTvars = new ListBuffer<>();
3550 // create new type variables without bounds
3551 for (Type t : tvars) {
3552 newTvars.append(new TypeVar(t.tsym, null, syms.botType,
3553 t.getMetadata()));
3554 }
3555 // the new bounds should use the new type variables in place
3556 // of the old
3557 List<Type> newBounds = newBoundsBuf.toList();
3558 from = tvars;
3559 to = newTvars.toList();
3560 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) {
3561 newBounds.head = subst(newBounds.head, from, to);
3562 }
3563 newBounds = newBoundsBuf.toList();
3564 // set the bounds of new type variables to the new bounds
3565 for (Type t : newTvars.toList()) {
3566 TypeVar tv = (TypeVar) t;
3567 tv.setUpperBound( newBounds.head );
3568 newBounds = newBounds.tail;
3569 }
3570 return newTvars.toList();
3571 }
3572
3573 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) {
3574 Type bound1 = subst(t.getUpperBound(), from, to);
3575 if (bound1 == t.getUpperBound())
3576 return t;
3577 else {
3578 // create new type variable without bounds
3579 TypeVar tv = new TypeVar(t.tsym, null, syms.botType,
3580 t.getMetadata());
3581 // the new bound should use the new type variable in place
3582 // of the old
3583 tv.setUpperBound( subst(bound1, List.of(t), List.of(tv)) );
3584 return tv;
3585 }
3586 }
3587 // </editor-fold>
3588
3589 // <editor-fold defaultstate="collapsed" desc="hasSameBounds">
3590 /**
3591 * Does t have the same bounds for quantified variables as s?
3592 */
3593 public boolean hasSameBounds(ForAll t, ForAll s) {
3594 List<Type> l1 = t.tvars;
3595 List<Type> l2 = s.tvars;
3596 while (l1.nonEmpty() && l2.nonEmpty() &&
3597 isSameType(l1.head.getUpperBound(),
3598 subst(l2.head.getUpperBound(),
3599 s.tvars,
3600 t.tvars))) {
3601 l1 = l1.tail;
3602 l2 = l2.tail;
3603 }
3604 return l1.isEmpty() && l2.isEmpty();
3605 }
3606 // </editor-fold>
3607
3608 // <editor-fold defaultstate="collapsed" desc="newInstances">
3609 /** Create new vector of type variables from list of variables
3610 * changing all recursive bounds from old to new list.
3611 */
3612 public List<Type> newInstances(List<Type> tvars) {
3613 List<Type> tvars1 = tvars.map(newInstanceFun);
3614 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) {
3615 TypeVar tv = (TypeVar) l.head;
3616 tv.setUpperBound( subst(tv.getUpperBound(), tvars, tvars1) );
3617 }
3618 return tvars1;
3619 }
3620 private static final TypeMapping<Void> newInstanceFun = new TypeMapping<Void>() {
3621 @Override
3622 public TypeVar visitTypeVar(TypeVar t, Void _unused) {
3623 return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound(), t.getMetadata());
3624 }
3625 };
3626 // </editor-fold>
3627
3628 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) {
3629 return original.accept(methodWithParameters, newParams);
3630 }
3631 // where
3632 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() {
3633 public Type visitType(Type t, List<Type> newParams) {
3634 throw new IllegalArgumentException("Not a method type: " + t);
3635 }
3636 public Type visitMethodType(MethodType t, List<Type> newParams) {
3637 return new MethodType(newParams, t.restype, t.thrown, t.tsym);
3638 }
3639 public Type visitForAll(ForAll t, List<Type> newParams) {
3640 return new ForAll(t.tvars, t.qtype.accept(this, newParams));
3641 }
3642 };
3643
3644 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) {
3645 return original.accept(methodWithThrown, newThrown);
3646 }
3647 // where
3648 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() {
3649 public Type visitType(Type t, List<Type> newThrown) {
3650 throw new IllegalArgumentException("Not a method type: " + t);
3651 }
3652 public Type visitMethodType(MethodType t, List<Type> newThrown) {
3653 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym);
3654 }
3655 public Type visitForAll(ForAll t, List<Type> newThrown) {
3656 return new ForAll(t.tvars, t.qtype.accept(this, newThrown));
3657 }
3658 };
3659
3660 public Type createMethodTypeWithReturn(Type original, Type newReturn) {
3661 return original.accept(methodWithReturn, newReturn);
3662 }
3663 // where
3664 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() {
3665 public Type visitType(Type t, Type newReturn) {
3666 throw new IllegalArgumentException("Not a method type: " + t);
3667 }
3668 public Type visitMethodType(MethodType t, Type newReturn) {
3669 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym) {
3670 @Override
3671 public Type baseType() {
3672 return t;
3673 }
3674 };
3675 }
3676 public Type visitForAll(ForAll t, Type newReturn) {
3677 return new ForAll(t.tvars, t.qtype.accept(this, newReturn)) {
3678 @Override
3679 public Type baseType() {
3680 return t;
3681 }
3682 };
3683 }
3684 };
3685
3686 // <editor-fold defaultstate="collapsed" desc="createErrorType">
3687 public Type createErrorType(Type originalType) {
3688 return new ErrorType(originalType, syms.errSymbol);
3689 }
3690
3691 public Type createErrorType(ClassSymbol c, Type originalType) {
3692 return new ErrorType(c, originalType);
3693 }
3694
3695 public Type createErrorType(Name name, TypeSymbol container, Type originalType) {
3696 return new ErrorType(name, container, originalType);
3697 }
3698 // </editor-fold>
3699
3700 // <editor-fold defaultstate="collapsed" desc="rank">
3701 /**
3702 * The rank of a class is the length of the longest path between
3703 * the class and java.lang.Object in the class inheritance
3704 * graph. Undefined for all but reference types.
3705 */
3706 public int rank(Type t) {
3707 switch(t.getTag()) {
3708 case CLASS: {
3709 ClassType cls = (ClassType)t;
3710 if (cls.rank_field < 0) {
3711 Name fullname = cls.tsym.getQualifiedName();
3712 if (fullname == names.java_lang_Object)
3713 cls.rank_field = 0;
3714 else {
3715 int r = rank(supertype(cls));
3716 for (List<Type> l = interfaces(cls);
3717 l.nonEmpty();
3718 l = l.tail) {
3719 if (rank(l.head) > r)
3720 r = rank(l.head);
3721 }
3722 cls.rank_field = r + 1;
3723 }
3724 }
3725 return cls.rank_field;
3726 }
3727 case TYPEVAR: {
3728 TypeVar tvar = (TypeVar)t;
3729 if (tvar.rank_field < 0) {
3730 int r = rank(supertype(tvar));
3731 for (List<Type> l = interfaces(tvar);
3732 l.nonEmpty();
3733 l = l.tail) {
3734 if (rank(l.head) > r) r = rank(l.head);
3735 }
3736 tvar.rank_field = r + 1;
3737 }
3738 return tvar.rank_field;
3739 }
3740 case ERROR:
3741 case NONE:
3742 return 0;
3743 default:
3744 throw new AssertionError();
3745 }
3746 }
3747 // </editor-fold>
3748
3749 /**
3750 * Helper method for generating a string representation of a given type
3751 * accordingly to a given locale
3752 */
3753 public String toString(Type t, Locale locale) {
3754 return Printer.createStandardPrinter(messages).visit(t, locale);
3755 }
3756
3757 /**
3758 * Helper method for generating a string representation of a given type
3759 * accordingly to a given locale
3760 */
3761 public String toString(Symbol t, Locale locale) {
3762 return Printer.createStandardPrinter(messages).visit(t, locale);
3763 }
3764
3765 // <editor-fold defaultstate="collapsed" desc="toString">
3766 /**
3767 * This toString is slightly more descriptive than the one on Type.
3768 *
3769 * @deprecated Types.toString(Type t, Locale l) provides better support
3770 * for localization
3771 */
3772 @Deprecated
3773 public String toString(Type t) {
3774 if (t.hasTag(FORALL)) {
3775 ForAll forAll = (ForAll)t;
3776 return typaramsString(forAll.tvars) + forAll.qtype;
3777 }
3778 return "" + t;
3779 }
3780 // where
3781 private String typaramsString(List<Type> tvars) {
3782 StringBuilder s = new StringBuilder();
3783 s.append('<');
3784 boolean first = true;
3785 for (Type t : tvars) {
3786 if (!first) s.append(", ");
3787 first = false;
3788 appendTyparamString(((TypeVar)t), s);
3789 }
3790 s.append('>');
3791 return s.toString();
3792 }
3793 private void appendTyparamString(TypeVar t, StringBuilder buf) {
3794 buf.append(t);
3795 if (t.getUpperBound() == null ||
3796 t.getUpperBound().tsym.getQualifiedName() == names.java_lang_Object)
3797 return;
3798 buf.append(" extends "); // Java syntax; no need for i18n
3799 Type bound = t.getUpperBound();
3800 if (!bound.isCompound()) {
3801 buf.append(bound);
3802 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) {
3803 buf.append(supertype(t));
3804 for (Type intf : interfaces(t)) {
3805 buf.append('&');
3806 buf.append(intf);
3807 }
3808 } else {
3809 // No superclass was given in bounds.
3810 // In this case, supertype is Object, erasure is first interface.
3811 boolean first = true;
3812 for (Type intf : interfaces(t)) {
3813 if (!first) buf.append('&');
3814 first = false;
3815 buf.append(intf);
3816 }
3817 }
3818 }
3819 // </editor-fold>
3820
3821 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types">
3822 /**
3823 * A cache for closures.
3824 *
3825 * <p>A closure is a list of all the supertypes and interfaces of
3826 * a class or interface type, ordered by ClassSymbol.precedes
3827 * (that is, subclasses come first, arbitrary but fixed
3828 * otherwise).
3829 */
3830 private Map<Type,List<Type>> closureCache = new HashMap<>();
3831
3832 /**
3833 * Returns the closure of a class or interface type.
3834 */
3835 public List<Type> closure(Type t) {
3836 List<Type> cl = closureCache.get(t);
3837 if (cl == null) {
3838 Type st = supertype(t);
3839 if (!t.isCompound()) {
3840 if (st.hasTag(CLASS)) {
3841 cl = insert(closure(st), t);
3842 } else if (st.hasTag(TYPEVAR)) {
3843 cl = closure(st).prepend(t);
3844 } else {
3845 cl = List.of(t);
3846 }
3847 } else {
3848 cl = closure(supertype(t));
3849 }
3850 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail)
3851 cl = union(cl, closure(l.head));
3852 closureCache.put(t, cl);
3853 }
3854 return cl;
3855 }
3856
3857 /**
3858 * Collect types into a new closure (using a @code{ClosureHolder})
3859 */
3860 public Collector<Type, ClosureHolder, List<Type>> closureCollector(boolean minClosure, BiPredicate<Type, Type> shouldSkip) {
3861 return Collector.of(() -> new ClosureHolder(minClosure, shouldSkip),
3862 ClosureHolder::add,
3863 ClosureHolder::merge,
3864 ClosureHolder::closure);
3865 }
3866 //where
3867 class ClosureHolder {
3868 List<Type> closure;
3869 final boolean minClosure;
3870 final BiPredicate<Type, Type> shouldSkip;
3871
3872 ClosureHolder(boolean minClosure, BiPredicate<Type, Type> shouldSkip) {
3873 this.closure = List.nil();
3874 this.minClosure = minClosure;
3875 this.shouldSkip = shouldSkip;
3876 }
3877
3878 void add(Type type) {
3879 closure = insert(closure, type, shouldSkip);
3880 }
3881
3882 ClosureHolder merge(ClosureHolder other) {
3883 closure = union(closure, other.closure, shouldSkip);
3884 return this;
3885 }
3886
3887 List<Type> closure() {
3888 return minClosure ? closureMin(closure) : closure;
3889 }
3890 }
3891
3892 BiPredicate<Type, Type> basicClosureSkip = (t1, t2) -> t1.tsym == t2.tsym;
3893
3894 /**
3895 * Insert a type in a closure
3896 */
3897 public List<Type> insert(List<Type> cl, Type t, BiPredicate<Type, Type> shouldSkip) {
3898 if (cl.isEmpty()) {
3899 return cl.prepend(t);
3900 } else if (shouldSkip.test(t, cl.head)) {
3901 return cl;
3902 } else if (t.tsym.precedes(cl.head.tsym, this)) {
3903 return cl.prepend(t);
3904 } else {
3905 // t comes after head, or the two are unrelated
3906 return insert(cl.tail, t, shouldSkip).prepend(cl.head);
3907 }
3908 }
3909
3910 public List<Type> insert(List<Type> cl, Type t) {
3911 return insert(cl, t, basicClosureSkip);
3912 }
3913
3914 /**
3915 * Form the union of two closures
3916 */
3917 public List<Type> union(List<Type> cl1, List<Type> cl2, BiPredicate<Type, Type> shouldSkip) {
3918 if (cl1.isEmpty()) {
3919 return cl2;
3920 } else if (cl2.isEmpty()) {
3921 return cl1;
3922 } else if (shouldSkip.test(cl1.head, cl2.head)) {
3923 return union(cl1.tail, cl2.tail, shouldSkip).prepend(cl1.head);
3924 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) {
3925 return union(cl1, cl2.tail, shouldSkip).prepend(cl2.head);
3926 } else {
3927 return union(cl1.tail, cl2, shouldSkip).prepend(cl1.head);
3928 }
3929 }
3930
3931 public List<Type> union(List<Type> cl1, List<Type> cl2) {
3932 return union(cl1, cl2, basicClosureSkip);
3933 }
3934
3935 /**
3936 * Intersect two closures
3937 */
3938 public List<Type> intersect(List<Type> cl1, List<Type> cl2) {
3939 if (cl1 == cl2)
3940 return cl1;
3941 if (cl1.isEmpty() || cl2.isEmpty())
3942 return List.nil();
3943 if (cl1.head.tsym.precedes(cl2.head.tsym, this))
3944 return intersect(cl1.tail, cl2);
3945 if (cl2.head.tsym.precedes(cl1.head.tsym, this))
3946 return intersect(cl1, cl2.tail);
3947 if (isSameType(cl1.head, cl2.head))
3948 return intersect(cl1.tail, cl2.tail).prepend(cl1.head);
3949 if (cl1.head.tsym == cl2.head.tsym &&
3950 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) {
3951 if (cl1.head.isParameterized() && cl2.head.isParameterized()) {
3952 Type merge = merge(cl1.head,cl2.head);
3953 return intersect(cl1.tail, cl2.tail).prepend(merge);
3954 }
3955 if (cl1.head.isRaw() || cl2.head.isRaw())
3956 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head));
3957 }
3958 return intersect(cl1.tail, cl2.tail);
3959 }
3960 // where
3961 class TypePair {
3962 final Type t1;
3963 final Type t2;;
3964
3965 TypePair(Type t1, Type t2) {
3966 this.t1 = t1;
3967 this.t2 = t2;
3968 }
3969 @Override
3970 public int hashCode() {
3971 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2);
3972 }
3973 @Override
3974 public boolean equals(Object obj) {
3975 return (obj instanceof TypePair typePair)
3976 && isSameType(t1, typePair.t1)
3977 && isSameType(t2, typePair.t2);
3978 }
3979 }
3980 Set<TypePair> mergeCache = new HashSet<>();
3981 private Type merge(Type c1, Type c2) {
3982 ClassType class1 = (ClassType) c1;
3983 List<Type> act1 = class1.getTypeArguments();
3984 ClassType class2 = (ClassType) c2;
3985 List<Type> act2 = class2.getTypeArguments();
3986 ListBuffer<Type> merged = new ListBuffer<>();
3987 List<Type> typarams = class1.tsym.type.getTypeArguments();
3988
3989 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) {
3990 if (containsType(act1.head, act2.head)) {
3991 merged.append(act1.head);
3992 } else if (containsType(act2.head, act1.head)) {
3993 merged.append(act2.head);
3994 } else {
3995 TypePair pair = new TypePair(c1, c2);
3996 Type m;
3997 if (mergeCache.add(pair)) {
3998 m = new WildcardType(lub(wildUpperBound(act1.head),
3999 wildUpperBound(act2.head)),
4000 BoundKind.EXTENDS,
4001 syms.boundClass);
4002 mergeCache.remove(pair);
4003 } else {
4004 m = new WildcardType(syms.objectType,
4005 BoundKind.UNBOUND,
4006 syms.boundClass);
4007 }
4008 merged.append(m.withTypeVar(typarams.head));
4009 }
4010 act1 = act1.tail;
4011 act2 = act2.tail;
4012 typarams = typarams.tail;
4013 }
4014 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty());
4015 // There is no spec detailing how type annotations are to
4016 // be inherited. So set it to noAnnotations for now
4017 return new ClassType(class1.getEnclosingType(), merged.toList(),
4018 class1.tsym, TypeMetadata.EMPTY, class1.getFlavor());
4019 }
4020
4021 /**
4022 * Return the minimum type of a closure, a compound type if no
4023 * unique minimum exists.
4024 */
4025 private Type compoundMin(List<Type> cl) {
4026 if (cl.isEmpty()) return syms.objectType;
4027 List<Type> compound = closureMin(cl);
4028 if (compound.isEmpty())
4029 return null;
4030 else if (compound.tail.isEmpty())
4031 return compound.head;
4032 else
4033 return makeIntersectionType(compound);
4034 }
4035
4036 /**
4037 * Return the minimum types of a closure, suitable for computing
4038 * compoundMin or glb.
4039 */
4040 private List<Type> closureMin(List<Type> cl) {
4041 ListBuffer<Type> classes = new ListBuffer<>();
4042 ListBuffer<Type> interfaces = new ListBuffer<>();
4043 Set<Type> toSkip = new HashSet<>();
4044 while (!cl.isEmpty()) {
4045 Type current = cl.head;
4046 boolean keep = !toSkip.contains(current);
4047 if (keep && current.hasTag(TYPEVAR)) {
4048 // skip lower-bounded variables with a subtype in cl.tail
4049 for (Type t : cl.tail) {
4050 if (isSubtypeNoCapture(t, current)) {
4051 keep = false;
4052 break;
4053 }
4054 }
4055 }
4056 if (keep) {
4057 if (current.isInterface())
4058 interfaces.append(current);
4059 else
4060 classes.append(current);
4061 for (Type t : cl.tail) {
4062 // skip supertypes of 'current' in cl.tail
4063 if (isSubtypeNoCapture(current, t))
4064 toSkip.add(t);
4065 }
4066 }
4067 cl = cl.tail;
4068 }
4069 return classes.appendList(interfaces).toList();
4070 }
4071
4072 /**
4073 * Return the least upper bound of list of types. if the lub does
4074 * not exist return null.
4075 */
4076 public Type lub(List<Type> ts) {
4077 return lub(ts.toArray(new Type[ts.length()]));
4078 }
4079
4080 /**
4081 * Return the least upper bound (lub) of set of types. If the lub
4082 * does not exist return the type of null (bottom).
4083 */
4084 public Type lub(Type... ts) {
4085 final int UNKNOWN_BOUND = 0;
4086 final int ARRAY_BOUND = 1;
4087 final int CLASS_BOUND = 2;
4088
4089 int[] kinds = new int[ts.length];
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 (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.getByteLength() + 1, c.flatname.getByteLength())
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 }