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src/share/classes/com/sun/tools/javac/code/Types.java@7c925f35f81c
src/share/classes/com/sun/tools/javac/code/Types.java
Fri, 23 May 2014 16:27:22 +0100
- author
- pgovereau
- date
- Fri, 23 May 2014 16:27:22 +0100
- changeset 2398
- 7c925f35f81c
- parent 2385
- 856d94394294
- child 2400
- 0e026d3f2786
- permissions
- -rw-r--r--
8033437: javac, inconsistent generic types behaviour when compiling together vs. separate
Reviewed-by: jjg
Contributed-by: vicente.romero@oracle.com, paul.govereau@oracle.com
1 /*
2 * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
26 package com.sun.tools.javac.code;
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.Set;
34 import java.util.WeakHashMap;
36 import javax.tools.JavaFileObject;
38 import com.sun.tools.javac.code.Attribute.RetentionPolicy;
39 import com.sun.tools.javac.code.Lint.LintCategory;
40 import com.sun.tools.javac.code.Type.UndetVar.InferenceBound;
41 import com.sun.tools.javac.comp.AttrContext;
42 import com.sun.tools.javac.comp.Check;
43 import com.sun.tools.javac.comp.Enter;
44 import com.sun.tools.javac.comp.Env;
45 import com.sun.tools.javac.jvm.ClassReader;
46 import com.sun.tools.javac.tree.JCTree;
47 import com.sun.tools.javac.util.*;
48 import static com.sun.tools.javac.code.BoundKind.*;
49 import static com.sun.tools.javac.code.Flags.*;
50 import static com.sun.tools.javac.code.Scope.*;
51 import static com.sun.tools.javac.code.Symbol.*;
52 import static com.sun.tools.javac.code.Type.*;
53 import static com.sun.tools.javac.code.TypeTag.*;
54 import static com.sun.tools.javac.jvm.ClassFile.externalize;
56 /**
57 * Utility class containing various operations on types.
58 *
59 * <p>Unless other names are more illustrative, the following naming
60 * conventions should be observed in this file:
61 *
62 * <dl>
63 * <dt>t</dt>
64 * <dd>If the first argument to an operation is a type, it should be named t.</dd>
65 * <dt>s</dt>
66 * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd>
67 * <dt>ts</dt>
68 * <dd>If an operations takes a list of types, the first should be named ts.</dd>
69 * <dt>ss</dt>
70 * <dd>A second list of types should be named ss.</dd>
71 * </dl>
72 *
73 * <p><b>This is NOT part of any supported API.
74 * If you write code that depends on this, you do so at your own risk.
75 * This code and its internal interfaces are subject to change or
76 * deletion without notice.</b>
77 */
78 public class Types {
79 protected static final Context.Key<Types> typesKey =
80 new Context.Key<Types>();
82 final Symtab syms;
83 final JavacMessages messages;
84 final Names names;
85 final boolean allowBoxing;
86 final boolean allowCovariantReturns;
87 final boolean allowObjectToPrimitiveCast;
88 final ClassReader reader;
89 final Check chk;
90 final Enter enter;
91 JCDiagnostic.Factory diags;
92 List<Warner> warnStack = List.nil();
93 final Name capturedName;
94 private final FunctionDescriptorLookupError functionDescriptorLookupError;
96 public final Warner noWarnings;
98 // <editor-fold defaultstate="collapsed" desc="Instantiating">
99 public static Types instance(Context context) {
100 Types instance = context.get(typesKey);
101 if (instance == null)
102 instance = new Types(context);
103 return instance;
104 }
106 protected Types(Context context) {
107 context.put(typesKey, this);
108 syms = Symtab.instance(context);
109 names = Names.instance(context);
110 Source source = Source.instance(context);
111 allowBoxing = source.allowBoxing();
112 allowCovariantReturns = source.allowCovariantReturns();
113 allowObjectToPrimitiveCast = source.allowObjectToPrimitiveCast();
114 reader = ClassReader.instance(context);
115 chk = Check.instance(context);
116 enter = Enter.instance(context);
117 capturedName = names.fromString("<captured wildcard>");
118 messages = JavacMessages.instance(context);
119 diags = JCDiagnostic.Factory.instance(context);
120 functionDescriptorLookupError = new FunctionDescriptorLookupError();
121 noWarnings = new Warner(null);
122 }
123 // </editor-fold>
125 // <editor-fold defaultstate="collapsed" desc="upperBound">
126 /**
127 * The "rvalue conversion".<br>
128 * The upper bound of most types is the type
129 * itself. Wildcards, on the other hand have upper
130 * and lower bounds.
131 * @param t a type
132 * @return the upper bound of the given type
133 */
134 public Type upperBound(Type t) {
135 return upperBound.visit(t).unannotatedType();
136 }
137 // where
138 private final MapVisitor<Void> upperBound = new MapVisitor<Void>() {
140 @Override
141 public Type visitWildcardType(WildcardType t, Void ignored) {
142 if (t.isSuperBound())
143 return t.bound == null ? syms.objectType : t.bound.bound;
144 else
145 return visit(t.type);
146 }
148 @Override
149 public Type visitCapturedType(CapturedType t, Void ignored) {
150 return visit(t.bound);
151 }
152 };
153 // </editor-fold>
155 // <editor-fold defaultstate="collapsed" desc="wildLowerBound">
156 /**
157 * Get a wildcard's lower bound, returning non-wildcards unchanged.
158 * @param t a type argument, either a wildcard or a type
159 */
160 public Type wildLowerBound(Type t) {
161 if (t.hasTag(WILDCARD)) {
162 WildcardType w = (WildcardType) t;
163 return w.isExtendsBound() ? syms.botType : wildLowerBound(w.type);
164 }
165 else return t;
166 }
167 // </editor-fold>
169 // <editor-fold defaultstate="collapsed" desc="cvarLowerBound">
170 /**
171 * Get a capture variable's lower bound, returning other types unchanged.
172 * @param t a type
173 */
174 public Type cvarLowerBound(Type t) {
175 if (t.hasTag(TYPEVAR) && ((TypeVar) t).isCaptured()) {
176 return cvarLowerBound(t.getLowerBound());
177 }
178 else return t;
179 }
180 // </editor-fold>
182 // <editor-fold defaultstate="collapsed" desc="isUnbounded">
183 /**
184 * Checks that all the arguments to a class are unbounded
185 * wildcards or something else that doesn't make any restrictions
186 * on the arguments. If a class isUnbounded, a raw super- or
187 * subclass can be cast to it without a warning.
188 * @param t a type
189 * @return true iff the given type is unbounded or raw
190 */
191 public boolean isUnbounded(Type t) {
192 return isUnbounded.visit(t);
193 }
194 // where
195 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() {
197 public Boolean visitType(Type t, Void ignored) {
198 return true;
199 }
201 @Override
202 public Boolean visitClassType(ClassType t, Void ignored) {
203 List<Type> parms = t.tsym.type.allparams();
204 List<Type> args = t.allparams();
205 while (parms.nonEmpty()) {
206 WildcardType unb = new WildcardType(syms.objectType,
207 BoundKind.UNBOUND,
208 syms.boundClass,
209 (TypeVar)parms.head.unannotatedType());
210 if (!containsType(args.head, unb))
211 return false;
212 parms = parms.tail;
213 args = args.tail;
214 }
215 return true;
216 }
217 };
218 // </editor-fold>
220 // <editor-fold defaultstate="collapsed" desc="asSub">
221 /**
222 * Return the least specific subtype of t that starts with symbol
223 * sym. If none exists, return null. The least specific subtype
224 * is determined as follows:
225 *
226 * <p>If there is exactly one parameterized instance of sym that is a
227 * subtype of t, that parameterized instance is returned.<br>
228 * Otherwise, if the plain type or raw type `sym' is a subtype of
229 * type t, the type `sym' itself is returned. Otherwise, null is
230 * returned.
231 */
232 public Type asSub(Type t, Symbol sym) {
233 return asSub.visit(t, sym);
234 }
235 // where
236 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() {
238 public Type visitType(Type t, Symbol sym) {
239 return null;
240 }
242 @Override
243 public Type visitClassType(ClassType t, Symbol sym) {
244 if (t.tsym == sym)
245 return t;
246 Type base = asSuper(sym.type, t.tsym);
247 if (base == null)
248 return null;
249 ListBuffer<Type> from = new ListBuffer<Type>();
250 ListBuffer<Type> to = new ListBuffer<Type>();
251 try {
252 adapt(base, t, from, to);
253 } catch (AdaptFailure ex) {
254 return null;
255 }
256 Type res = subst(sym.type, from.toList(), to.toList());
257 if (!isSubtype(res, t))
258 return null;
259 ListBuffer<Type> openVars = new ListBuffer<Type>();
260 for (List<Type> l = sym.type.allparams();
261 l.nonEmpty(); l = l.tail)
262 if (res.contains(l.head) && !t.contains(l.head))
263 openVars.append(l.head);
264 if (openVars.nonEmpty()) {
265 if (t.isRaw()) {
266 // The subtype of a raw type is raw
267 res = erasure(res);
268 } else {
269 // Unbound type arguments default to ?
270 List<Type> opens = openVars.toList();
271 ListBuffer<Type> qs = new ListBuffer<Type>();
272 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) {
273 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND, syms.boundClass, (TypeVar) iter.head.unannotatedType()));
274 }
275 res = subst(res, opens, qs.toList());
276 }
277 }
278 return res;
279 }
281 @Override
282 public Type visitErrorType(ErrorType t, Symbol sym) {
283 return t;
284 }
285 };
286 // </editor-fold>
288 // <editor-fold defaultstate="collapsed" desc="isConvertible">
289 /**
290 * Is t a subtype of or convertible via boxing/unboxing
291 * conversion to s?
292 */
293 public boolean isConvertible(Type t, Type s, Warner warn) {
294 if (t.hasTag(ERROR)) {
295 return true;
296 }
297 boolean tPrimitive = t.isPrimitive();
298 boolean sPrimitive = s.isPrimitive();
299 if (tPrimitive == sPrimitive) {
300 return isSubtypeUnchecked(t, s, warn);
301 }
302 if (!allowBoxing) return false;
303 return tPrimitive
304 ? isSubtype(boxedClass(t).type, s)
305 : isSubtype(unboxedType(t), s);
306 }
308 /**
309 * Is t a subtype of or convertible via boxing/unboxing
310 * conversions to s?
311 */
312 public boolean isConvertible(Type t, Type s) {
313 return isConvertible(t, s, noWarnings);
314 }
315 // </editor-fold>
317 // <editor-fold defaultstate="collapsed" desc="findSam">
319 /**
320 * Exception used to report a function descriptor lookup failure. The exception
321 * wraps a diagnostic that can be used to generate more details error
322 * messages.
323 */
324 public static class FunctionDescriptorLookupError extends RuntimeException {
325 private static final long serialVersionUID = 0;
327 JCDiagnostic diagnostic;
329 FunctionDescriptorLookupError() {
330 this.diagnostic = null;
331 }
333 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) {
334 this.diagnostic = diag;
335 return this;
336 }
338 public JCDiagnostic getDiagnostic() {
339 return diagnostic;
340 }
341 }
343 /**
344 * A cache that keeps track of function descriptors associated with given
345 * functional interfaces.
346 */
347 class DescriptorCache {
349 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<TypeSymbol, Entry>();
351 class FunctionDescriptor {
352 Symbol descSym;
354 FunctionDescriptor(Symbol descSym) {
355 this.descSym = descSym;
356 }
358 public Symbol getSymbol() {
359 return descSym;
360 }
362 public Type getType(Type site) {
363 site = removeWildcards(site);
364 if (!chk.checkValidGenericType(site)) {
365 //if the inferred functional interface type is not well-formed,
366 //or if it's not a subtype of the original target, issue an error
367 throw failure(diags.fragment("no.suitable.functional.intf.inst", site));
368 }
369 return memberType(site, descSym);
370 }
371 }
373 class Entry {
374 final FunctionDescriptor cachedDescRes;
375 final int prevMark;
377 public Entry(FunctionDescriptor cachedDescRes,
378 int prevMark) {
379 this.cachedDescRes = cachedDescRes;
380 this.prevMark = prevMark;
381 }
383 boolean matches(int mark) {
384 return this.prevMark == mark;
385 }
386 }
388 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError {
389 Entry e = _map.get(origin);
390 CompoundScope members = membersClosure(origin.type, false);
391 if (e == null ||
392 !e.matches(members.getMark())) {
393 FunctionDescriptor descRes = findDescriptorInternal(origin, members);
394 _map.put(origin, new Entry(descRes, members.getMark()));
395 return descRes;
396 }
397 else {
398 return e.cachedDescRes;
399 }
400 }
402 /**
403 * Compute the function descriptor associated with a given functional interface
404 */
405 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin,
406 CompoundScope membersCache) throws FunctionDescriptorLookupError {
407 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0) {
408 //t must be an interface
409 throw failure("not.a.functional.intf", origin);
410 }
412 final ListBuffer<Symbol> abstracts = new ListBuffer<>();
413 for (Symbol sym : membersCache.getElements(new DescriptorFilter(origin))) {
414 Type mtype = memberType(origin.type, sym);
415 if (abstracts.isEmpty() ||
416 (sym.name == abstracts.first().name &&
417 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) {
418 abstracts.append(sym);
419 } else {
420 //the target method(s) should be the only abstract members of t
421 throw failure("not.a.functional.intf.1", origin,
422 diags.fragment("incompatible.abstracts", Kinds.kindName(origin), origin));
423 }
424 }
425 if (abstracts.isEmpty()) {
426 //t must define a suitable non-generic method
427 throw failure("not.a.functional.intf.1", origin,
428 diags.fragment("no.abstracts", Kinds.kindName(origin), origin));
429 } else if (abstracts.size() == 1) {
430 return new FunctionDescriptor(abstracts.first());
431 } else { // size > 1
432 FunctionDescriptor descRes = mergeDescriptors(origin, abstracts.toList());
433 if (descRes == null) {
434 //we can get here if the functional interface is ill-formed
435 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>();
436 for (Symbol desc : abstracts) {
437 String key = desc.type.getThrownTypes().nonEmpty() ?
438 "descriptor.throws" : "descriptor";
439 descriptors.append(diags.fragment(key, desc.name,
440 desc.type.getParameterTypes(),
441 desc.type.getReturnType(),
442 desc.type.getThrownTypes()));
443 }
444 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors =
445 new JCDiagnostic.MultilineDiagnostic(diags.fragment("incompatible.descs.in.functional.intf",
446 Kinds.kindName(origin), origin), descriptors.toList());
447 throw failure(incompatibleDescriptors);
448 }
449 return descRes;
450 }
451 }
453 /**
454 * Compute a synthetic type for the target descriptor given a list
455 * of override-equivalent methods in the functional interface type.
456 * The resulting method type is a method type that is override-equivalent
457 * and return-type substitutable with each method in the original list.
458 */
459 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) {
460 //pick argument types - simply take the signature that is a
461 //subsignature of all other signatures in the list (as per JLS 8.4.2)
462 List<Symbol> mostSpecific = List.nil();
463 outer: for (Symbol msym1 : methodSyms) {
464 Type mt1 = memberType(origin.type, msym1);
465 for (Symbol msym2 : methodSyms) {
466 Type mt2 = memberType(origin.type, msym2);
467 if (!isSubSignature(mt1, mt2)) {
468 continue outer;
469 }
470 }
471 mostSpecific = mostSpecific.prepend(msym1);
472 }
473 if (mostSpecific.isEmpty()) {
474 return null;
475 }
478 //pick return types - this is done in two phases: (i) first, the most
479 //specific return type is chosen using strict subtyping; if this fails,
480 //a second attempt is made using return type substitutability (see JLS 8.4.5)
481 boolean phase2 = false;
482 Symbol bestSoFar = null;
483 while (bestSoFar == null) {
484 outer: for (Symbol msym1 : mostSpecific) {
485 Type mt1 = memberType(origin.type, msym1);
486 for (Symbol msym2 : methodSyms) {
487 Type mt2 = memberType(origin.type, msym2);
488 if (phase2 ?
489 !returnTypeSubstitutable(mt1, mt2) :
490 !isSubtypeInternal(mt1.getReturnType(), mt2.getReturnType())) {
491 continue outer;
492 }
493 }
494 bestSoFar = msym1;
495 }
496 if (phase2) {
497 break;
498 } else {
499 phase2 = true;
500 }
501 }
502 if (bestSoFar == null) return null;
504 //merge thrown types - form the intersection of all the thrown types in
505 //all the signatures in the list
506 boolean toErase = !bestSoFar.type.hasTag(FORALL);
507 List<Type> thrown = null;
508 Type mt1 = memberType(origin.type, bestSoFar);
509 for (Symbol msym2 : methodSyms) {
510 Type mt2 = memberType(origin.type, msym2);
511 List<Type> thrown_mt2 = mt2.getThrownTypes();
512 if (toErase) {
513 thrown_mt2 = erasure(thrown_mt2);
514 } else {
515 /* If bestSoFar is generic then all the methods are generic.
516 * The opposite is not true: a non generic method can override
517 * a generic method (raw override) so it's safe to cast mt1 and
518 * mt2 to ForAll.
519 */
520 ForAll fa1 = (ForAll)mt1;
521 ForAll fa2 = (ForAll)mt2;
522 thrown_mt2 = subst(thrown_mt2, fa2.tvars, fa1.tvars);
523 }
524 thrown = (thrown == null) ?
525 thrown_mt2 :
526 chk.intersect(thrown_mt2, thrown);
527 }
529 final List<Type> thrown1 = thrown;
530 return new FunctionDescriptor(bestSoFar) {
531 @Override
532 public Type getType(Type origin) {
533 Type mt = memberType(origin, getSymbol());
534 return createMethodTypeWithThrown(mt, thrown1);
535 }
536 };
537 }
539 boolean isSubtypeInternal(Type s, Type t) {
540 return (s.isPrimitive() && t.isPrimitive()) ?
541 isSameType(t, s) :
542 isSubtype(s, t);
543 }
545 FunctionDescriptorLookupError failure(String msg, Object... args) {
546 return failure(diags.fragment(msg, args));
547 }
549 FunctionDescriptorLookupError failure(JCDiagnostic diag) {
550 return functionDescriptorLookupError.setMessage(diag);
551 }
552 }
554 private DescriptorCache descCache = new DescriptorCache();
556 /**
557 * Find the method descriptor associated to this class symbol - if the
558 * symbol 'origin' is not a functional interface, an exception is thrown.
559 */
560 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError {
561 return descCache.get(origin).getSymbol();
562 }
564 /**
565 * Find the type of the method descriptor associated to this class symbol -
566 * if the symbol 'origin' is not a functional interface, an exception is thrown.
567 */
568 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError {
569 return descCache.get(origin.tsym).getType(origin);
570 }
572 /**
573 * Is given type a functional interface?
574 */
575 public boolean isFunctionalInterface(TypeSymbol tsym) {
576 try {
577 findDescriptorSymbol(tsym);
578 return true;
579 } catch (FunctionDescriptorLookupError ex) {
580 return false;
581 }
582 }
584 public boolean isFunctionalInterface(Type site) {
585 try {
586 findDescriptorType(site);
587 return true;
588 } catch (FunctionDescriptorLookupError ex) {
589 return false;
590 }
591 }
593 public Type removeWildcards(Type site) {
594 Type capturedSite = capture(site);
595 if (capturedSite != site) {
596 Type formalInterface = site.tsym.type;
597 ListBuffer<Type> typeargs = new ListBuffer<>();
598 List<Type> actualTypeargs = site.getTypeArguments();
599 List<Type> capturedTypeargs = capturedSite.getTypeArguments();
600 //simply replace the wildcards with its bound
601 for (Type t : formalInterface.getTypeArguments()) {
602 if (actualTypeargs.head.hasTag(WILDCARD)) {
603 WildcardType wt = (WildcardType)actualTypeargs.head.unannotatedType();
604 Type bound;
605 switch (wt.kind) {
606 case EXTENDS:
607 case UNBOUND:
608 CapturedType capVar = (CapturedType)capturedTypeargs.head.unannotatedType();
609 //use declared bound if it doesn't depend on formal type-args
610 bound = capVar.bound.containsAny(capturedSite.getTypeArguments()) ?
611 wt.type : capVar.bound;
612 break;
613 default:
614 bound = wt.type;
615 }
616 typeargs.append(bound);
617 } else {
618 typeargs.append(actualTypeargs.head);
619 }
620 actualTypeargs = actualTypeargs.tail;
621 capturedTypeargs = capturedTypeargs.tail;
622 }
623 return subst(formalInterface, formalInterface.getTypeArguments(), typeargs.toList());
624 } else {
625 return site;
626 }
627 }
629 /**
630 * Create a symbol for a class that implements a given functional interface
631 * and overrides its functional descriptor. This routine is used for two
632 * main purposes: (i) checking well-formedness of a functional interface;
633 * (ii) perform functional interface bridge calculation.
634 */
635 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, List<Type> targets, long cflags) {
636 if (targets.isEmpty() || !isFunctionalInterface(targets.head)) {
637 return null;
638 }
639 Symbol descSym = findDescriptorSymbol(targets.head.tsym);
640 Type descType = findDescriptorType(targets.head);
641 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass());
642 csym.completer = null;
643 csym.members_field = new Scope(csym);
644 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym);
645 csym.members_field.enter(instDescSym);
646 Type.ClassType ctype = new Type.ClassType(Type.noType, List.<Type>nil(), csym);
647 ctype.supertype_field = syms.objectType;
648 ctype.interfaces_field = targets;
649 csym.type = ctype;
650 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile;
651 return csym;
652 }
654 /**
655 * Find the minimal set of methods that are overridden by the functional
656 * descriptor in 'origin'. All returned methods are assumed to have different
657 * erased signatures.
658 */
659 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) {
660 Assert.check(isFunctionalInterface(origin));
661 Symbol descSym = findDescriptorSymbol(origin);
662 CompoundScope members = membersClosure(origin.type, false);
663 ListBuffer<Symbol> overridden = new ListBuffer<>();
664 outer: for (Symbol m2 : members.getElementsByName(descSym.name, bridgeFilter)) {
665 if (m2 == descSym) continue;
666 else if (descSym.overrides(m2, origin, Types.this, false)) {
667 for (Symbol m3 : overridden) {
668 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) ||
669 (m3.overrides(m2, origin, Types.this, false) &&
670 (pendingBridges((ClassSymbol)origin, m3.enclClass()) ||
671 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) {
672 continue outer;
673 }
674 }
675 overridden.add(m2);
676 }
677 }
678 return overridden.toList();
679 }
680 //where
681 private Filter<Symbol> bridgeFilter = new Filter<Symbol>() {
682 public boolean accepts(Symbol t) {
683 return t.kind == Kinds.MTH &&
684 t.name != names.init &&
685 t.name != names.clinit &&
686 (t.flags() & SYNTHETIC) == 0;
687 }
688 };
689 private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) {
690 //a symbol will be completed from a classfile if (a) symbol has
691 //an associated file object with CLASS kind and (b) the symbol has
692 //not been entered
693 if (origin.classfile != null &&
694 origin.classfile.getKind() == JavaFileObject.Kind.CLASS &&
695 enter.getEnv(origin) == null) {
696 return false;
697 }
698 if (origin == s) {
699 return true;
700 }
701 for (Type t : interfaces(origin.type)) {
702 if (pendingBridges((ClassSymbol)t.tsym, s)) {
703 return true;
704 }
705 }
706 return false;
707 }
708 // </editor-fold>
710 /**
711 * Scope filter used to skip methods that should be ignored (such as methods
712 * overridden by j.l.Object) during function interface conversion interface check
713 */
714 class DescriptorFilter implements Filter<Symbol> {
716 TypeSymbol origin;
718 DescriptorFilter(TypeSymbol origin) {
719 this.origin = origin;
720 }
722 @Override
723 public boolean accepts(Symbol sym) {
724 return sym.kind == Kinds.MTH &&
725 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT &&
726 !overridesObjectMethod(origin, sym) &&
727 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0;
728 }
729 };
731 // <editor-fold defaultstate="collapsed" desc="isSubtype">
732 /**
733 * Is t an unchecked subtype of s?
734 */
735 public boolean isSubtypeUnchecked(Type t, Type s) {
736 return isSubtypeUnchecked(t, s, noWarnings);
737 }
738 /**
739 * Is t an unchecked subtype of s?
740 */
741 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) {
742 boolean result = isSubtypeUncheckedInternal(t, s, warn);
743 if (result) {
744 checkUnsafeVarargsConversion(t, s, warn);
745 }
746 return result;
747 }
748 //where
749 private boolean isSubtypeUncheckedInternal(Type t, Type s, Warner warn) {
750 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) {
751 t = t.unannotatedType();
752 s = s.unannotatedType();
753 if (((ArrayType)t).elemtype.isPrimitive()) {
754 return isSameType(elemtype(t), elemtype(s));
755 } else {
756 return isSubtypeUnchecked(elemtype(t), elemtype(s), warn);
757 }
758 } else if (isSubtype(t, s)) {
759 return true;
760 } else if (t.hasTag(TYPEVAR)) {
761 return isSubtypeUnchecked(t.getUpperBound(), s, warn);
762 } else if (!s.isRaw()) {
763 Type t2 = asSuper(t, s.tsym);
764 if (t2 != null && t2.isRaw()) {
765 if (isReifiable(s)) {
766 warn.silentWarn(LintCategory.UNCHECKED);
767 } else {
768 warn.warn(LintCategory.UNCHECKED);
769 }
770 return true;
771 }
772 }
773 return false;
774 }
776 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) {
777 if (!t.hasTag(ARRAY) || isReifiable(t)) {
778 return;
779 }
780 t = t.unannotatedType();
781 s = s.unannotatedType();
782 ArrayType from = (ArrayType)t;
783 boolean shouldWarn = false;
784 switch (s.getTag()) {
785 case ARRAY:
786 ArrayType to = (ArrayType)s;
787 shouldWarn = from.isVarargs() &&
788 !to.isVarargs() &&
789 !isReifiable(from);
790 break;
791 case CLASS:
792 shouldWarn = from.isVarargs();
793 break;
794 }
795 if (shouldWarn) {
796 warn.warn(LintCategory.VARARGS);
797 }
798 }
800 /**
801 * Is t a subtype of s?<br>
802 * (not defined for Method and ForAll types)
803 */
804 final public boolean isSubtype(Type t, Type s) {
805 return isSubtype(t, s, true);
806 }
807 final public boolean isSubtypeNoCapture(Type t, Type s) {
808 return isSubtype(t, s, false);
809 }
810 public boolean isSubtype(Type t, Type s, boolean capture) {
811 if (t == s)
812 return true;
814 t = t.unannotatedType();
815 s = s.unannotatedType();
817 if (t == s)
818 return true;
820 if (s.isPartial())
821 return isSuperType(s, t);
823 if (s.isCompound()) {
824 for (Type s2 : interfaces(s).prepend(supertype(s))) {
825 if (!isSubtype(t, s2, capture))
826 return false;
827 }
828 return true;
829 }
831 // Generally, if 's' is a type variable, recur on lower bound; but
832 // for inference variables and intersections, we need to keep 's'
833 // (see JLS 4.10.2 for intersections and 18.2.3 for inference vars)
834 if (!t.hasTag(UNDETVAR) && !t.isCompound()) {
835 // TODO: JDK-8039198, bounds checking sometimes passes in a wildcard as s
836 Type lower = cvarLowerBound(wildLowerBound(s));
837 if (s != lower)
838 return isSubtype(capture ? capture(t) : t, lower, false);
839 }
841 return isSubtype.visit(capture ? capture(t) : t, s);
842 }
843 // where
844 private TypeRelation isSubtype = new TypeRelation()
845 {
846 @Override
847 public Boolean visitType(Type t, Type s) {
848 switch (t.getTag()) {
849 case BYTE:
850 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag()));
851 case CHAR:
852 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag()));
853 case SHORT: case INT: case LONG:
854 case FLOAT: case DOUBLE:
855 return t.getTag().isSubRangeOf(s.getTag());
856 case BOOLEAN: case VOID:
857 return t.hasTag(s.getTag());
858 case TYPEVAR:
859 return isSubtypeNoCapture(t.getUpperBound(), s);
860 case BOT:
861 return
862 s.hasTag(BOT) || s.hasTag(CLASS) ||
863 s.hasTag(ARRAY) || s.hasTag(TYPEVAR);
864 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495)
865 case NONE:
866 return false;
867 default:
868 throw new AssertionError("isSubtype " + t.getTag());
869 }
870 }
872 private Set<TypePair> cache = new HashSet<TypePair>();
874 private boolean containsTypeRecursive(Type t, Type s) {
875 TypePair pair = new TypePair(t, s);
876 if (cache.add(pair)) {
877 try {
878 return containsType(t.getTypeArguments(),
879 s.getTypeArguments());
880 } finally {
881 cache.remove(pair);
882 }
883 } else {
884 return containsType(t.getTypeArguments(),
885 rewriteSupers(s).getTypeArguments());
886 }
887 }
889 private Type rewriteSupers(Type t) {
890 if (!t.isParameterized())
891 return t;
892 ListBuffer<Type> from = new ListBuffer<>();
893 ListBuffer<Type> to = new ListBuffer<>();
894 adaptSelf(t, from, to);
895 if (from.isEmpty())
896 return t;
897 ListBuffer<Type> rewrite = new ListBuffer<>();
898 boolean changed = false;
899 for (Type orig : to.toList()) {
900 Type s = rewriteSupers(orig);
901 if (s.isSuperBound() && !s.isExtendsBound()) {
902 s = new WildcardType(syms.objectType,
903 BoundKind.UNBOUND,
904 syms.boundClass);
905 changed = true;
906 } else if (s != orig) {
907 s = new WildcardType(upperBound(s),
908 BoundKind.EXTENDS,
909 syms.boundClass);
910 changed = true;
911 }
912 rewrite.append(s);
913 }
914 if (changed)
915 return subst(t.tsym.type, from.toList(), rewrite.toList());
916 else
917 return t;
918 }
920 @Override
921 public Boolean visitClassType(ClassType t, Type s) {
922 Type sup = asSuper(t, s.tsym);
923 if (sup == null) return false;
924 // If t is an intersection, sup might not be a class type
925 if (!sup.hasTag(CLASS)) return isSubtypeNoCapture(sup, s);
926 return sup.tsym == s.tsym
927 // Check type variable containment
928 && (!s.isParameterized() || containsTypeRecursive(s, sup))
929 && isSubtypeNoCapture(sup.getEnclosingType(),
930 s.getEnclosingType());
931 }
933 @Override
934 public Boolean visitArrayType(ArrayType t, Type s) {
935 if (s.hasTag(ARRAY)) {
936 if (t.elemtype.isPrimitive())
937 return isSameType(t.elemtype, elemtype(s));
938 else
939 return isSubtypeNoCapture(t.elemtype, elemtype(s));
940 }
942 if (s.hasTag(CLASS)) {
943 Name sname = s.tsym.getQualifiedName();
944 return sname == names.java_lang_Object
945 || sname == names.java_lang_Cloneable
946 || sname == names.java_io_Serializable;
947 }
949 return false;
950 }
952 @Override
953 public Boolean visitUndetVar(UndetVar t, Type s) {
954 //todo: test against origin needed? or replace with substitution?
955 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
956 return true;
957 } else if (s.hasTag(BOT)) {
958 //if 's' is 'null' there's no instantiated type U for which
959 //U <: s (but 'null' itself, which is not a valid type)
960 return false;
961 }
963 t.addBound(InferenceBound.UPPER, s, Types.this);
964 return true;
965 }
967 @Override
968 public Boolean visitErrorType(ErrorType t, Type s) {
969 return true;
970 }
971 };
973 /**
974 * Is t a subtype of every type in given list `ts'?<br>
975 * (not defined for Method and ForAll types)<br>
976 * Allows unchecked conversions.
977 */
978 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) {
979 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
980 if (!isSubtypeUnchecked(t, l.head, warn))
981 return false;
982 return true;
983 }
985 /**
986 * Are corresponding elements of ts subtypes of ss? If lists are
987 * of different length, return false.
988 */
989 public boolean isSubtypes(List<Type> ts, List<Type> ss) {
990 while (ts.tail != null && ss.tail != null
991 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
992 isSubtype(ts.head, ss.head)) {
993 ts = ts.tail;
994 ss = ss.tail;
995 }
996 return ts.tail == null && ss.tail == null;
997 /*inlined: ts.isEmpty() && ss.isEmpty();*/
998 }
1000 /**
1001 * Are corresponding elements of ts subtypes of ss, allowing
1002 * unchecked conversions? If lists are of different length,
1003 * return false.
1004 **/
1005 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) {
1006 while (ts.tail != null && ss.tail != null
1007 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1008 isSubtypeUnchecked(ts.head, ss.head, warn)) {
1009 ts = ts.tail;
1010 ss = ss.tail;
1011 }
1012 return ts.tail == null && ss.tail == null;
1013 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1014 }
1015 // </editor-fold>
1017 // <editor-fold defaultstate="collapsed" desc="isSuperType">
1018 /**
1019 * Is t a supertype of s?
1020 */
1021 public boolean isSuperType(Type t, Type s) {
1022 switch (t.getTag()) {
1023 case ERROR:
1024 return true;
1025 case UNDETVAR: {
1026 UndetVar undet = (UndetVar)t;
1027 if (t == s ||
1028 undet.qtype == s ||
1029 s.hasTag(ERROR) ||
1030 s.hasTag(BOT)) {
1031 return true;
1032 }
1033 undet.addBound(InferenceBound.LOWER, s, this);
1034 return true;
1035 }
1036 default:
1037 return isSubtype(s, t);
1038 }
1039 }
1040 // </editor-fold>
1042 // <editor-fold defaultstate="collapsed" desc="isSameType">
1043 /**
1044 * Are corresponding elements of the lists the same type? If
1045 * lists are of different length, return false.
1046 */
1047 public boolean isSameTypes(List<Type> ts, List<Type> ss) {
1048 return isSameTypes(ts, ss, false);
1049 }
1050 public boolean isSameTypes(List<Type> ts, List<Type> ss, boolean strict) {
1051 while (ts.tail != null && ss.tail != null
1052 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1053 isSameType(ts.head, ss.head, strict)) {
1054 ts = ts.tail;
1055 ss = ss.tail;
1056 }
1057 return ts.tail == null && ss.tail == null;
1058 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1059 }
1061 /**
1062 * A polymorphic signature method (JLS SE 7, 8.4.1) is a method that
1063 * (i) is declared in the java.lang.invoke.MethodHandle class, (ii) takes
1064 * a single variable arity parameter (iii) whose declared type is Object[],
1065 * (iv) has a return type of Object and (v) is native.
1066 */
1067 public boolean isSignaturePolymorphic(MethodSymbol msym) {
1068 List<Type> argtypes = msym.type.getParameterTypes();
1069 return (msym.flags_field & NATIVE) != 0 &&
1070 msym.owner == syms.methodHandleType.tsym &&
1071 argtypes.tail.tail == null &&
1072 argtypes.head.hasTag(TypeTag.ARRAY) &&
1073 msym.type.getReturnType().tsym == syms.objectType.tsym &&
1074 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym;
1075 }
1077 /**
1078 * Is t the same type as s?
1079 */
1080 public boolean isSameType(Type t, Type s) {
1081 return isSameType(t, s, false);
1082 }
1083 public boolean isSameType(Type t, Type s, boolean strict) {
1084 return strict ?
1085 isSameTypeStrict.visit(t, s) :
1086 isSameTypeLoose.visit(t, s);
1087 }
1088 public boolean isSameAnnotatedType(Type t, Type s) {
1089 return isSameAnnotatedType.visit(t, s);
1090 }
1091 // where
1092 abstract class SameTypeVisitor extends TypeRelation {
1094 public Boolean visitType(Type t, Type s) {
1095 if (t == s)
1096 return true;
1098 if (s.isPartial())
1099 return visit(s, t);
1101 switch (t.getTag()) {
1102 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1103 case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE:
1104 return t.hasTag(s.getTag());
1105 case TYPEVAR: {
1106 if (s.hasTag(TYPEVAR)) {
1107 //type-substitution does not preserve type-var types
1108 //check that type var symbols and bounds are indeed the same
1109 return sameTypeVars((TypeVar)t.unannotatedType(), (TypeVar)s.unannotatedType());
1110 }
1111 else {
1112 //special case for s == ? super X, where upper(s) = u
1113 //check that u == t, where u has been set by Type.withTypeVar
1114 return s.isSuperBound() &&
1115 !s.isExtendsBound() &&
1116 visit(t, upperBound(s));
1117 }
1118 }
1119 default:
1120 throw new AssertionError("isSameType " + t.getTag());
1121 }
1122 }
1124 abstract boolean sameTypeVars(TypeVar tv1, TypeVar tv2);
1126 @Override
1127 public Boolean visitWildcardType(WildcardType t, Type s) {
1128 if (s.isPartial())
1129 return visit(s, t);
1130 else
1131 return false;
1132 }
1134 @Override
1135 public Boolean visitClassType(ClassType t, Type s) {
1136 if (t == s)
1137 return true;
1139 if (s.isPartial())
1140 return visit(s, t);
1142 if (s.isSuperBound() && !s.isExtendsBound())
1143 return visit(t, upperBound(s)) && visit(t, wildLowerBound(s));
1145 if (t.isCompound() && s.isCompound()) {
1146 if (!visit(supertype(t), supertype(s)))
1147 return false;
1149 HashSet<UniqueType> set = new HashSet<UniqueType>();
1150 for (Type x : interfaces(t))
1151 set.add(new UniqueType(x.unannotatedType(), Types.this));
1152 for (Type x : interfaces(s)) {
1153 if (!set.remove(new UniqueType(x.unannotatedType(), Types.this)))
1154 return false;
1155 }
1156 return (set.isEmpty());
1157 }
1158 return t.tsym == s.tsym
1159 && visit(t.getEnclosingType(), s.getEnclosingType())
1160 && containsTypes(t.getTypeArguments(), s.getTypeArguments());
1161 }
1163 abstract protected boolean containsTypes(List<Type> ts1, List<Type> ts2);
1165 @Override
1166 public Boolean visitArrayType(ArrayType t, Type s) {
1167 if (t == s)
1168 return true;
1170 if (s.isPartial())
1171 return visit(s, t);
1173 return s.hasTag(ARRAY)
1174 && containsTypeEquivalent(t.elemtype, elemtype(s));
1175 }
1177 @Override
1178 public Boolean visitMethodType(MethodType t, Type s) {
1179 // isSameType for methods does not take thrown
1180 // exceptions into account!
1181 return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType());
1182 }
1184 @Override
1185 public Boolean visitPackageType(PackageType t, Type s) {
1186 return t == s;
1187 }
1189 @Override
1190 public Boolean visitForAll(ForAll t, Type s) {
1191 if (!s.hasTag(FORALL)) {
1192 return false;
1193 }
1195 ForAll forAll = (ForAll)s;
1196 return hasSameBounds(t, forAll)
1197 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
1198 }
1200 @Override
1201 public Boolean visitUndetVar(UndetVar t, Type s) {
1202 if (s.hasTag(WILDCARD)) {
1203 // FIXME, this might be leftovers from before capture conversion
1204 return false;
1205 }
1207 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1208 return true;
1209 }
1211 t.addBound(InferenceBound.EQ, s, Types.this);
1213 return true;
1214 }
1216 @Override
1217 public Boolean visitErrorType(ErrorType t, Type s) {
1218 return true;
1219 }
1220 }
1222 /**
1223 * Standard type-equality relation - type variables are considered
1224 * equals if they share the same type symbol.
1225 */
1226 TypeRelation isSameTypeLoose = new LooseSameTypeVisitor();
1228 private class LooseSameTypeVisitor extends SameTypeVisitor {
1229 @Override
1230 boolean sameTypeVars(TypeVar tv1, TypeVar tv2) {
1231 return tv1.tsym == tv2.tsym && visit(tv1.getUpperBound(), tv2.getUpperBound());
1232 }
1233 @Override
1234 protected boolean containsTypes(List<Type> ts1, List<Type> ts2) {
1235 return containsTypeEquivalent(ts1, ts2);
1236 }
1237 };
1239 /**
1240 * Strict type-equality relation - type variables are considered
1241 * equals if they share the same object identity.
1242 */
1243 TypeRelation isSameTypeStrict = new SameTypeVisitor() {
1244 @Override
1245 boolean sameTypeVars(TypeVar tv1, TypeVar tv2) {
1246 return tv1 == tv2;
1247 }
1248 @Override
1249 protected boolean containsTypes(List<Type> ts1, List<Type> ts2) {
1250 return isSameTypes(ts1, ts2, true);
1251 }
1253 @Override
1254 public Boolean visitWildcardType(WildcardType t, Type s) {
1255 if (!s.hasTag(WILDCARD)) {
1256 return false;
1257 } else {
1258 WildcardType t2 = (WildcardType)s.unannotatedType();
1259 return t.kind == t2.kind &&
1260 isSameType(t.type, t2.type, true);
1261 }
1262 }
1263 };
1265 /**
1266 * A version of LooseSameTypeVisitor that takes AnnotatedTypes
1267 * into account.
1268 */
1269 TypeRelation isSameAnnotatedType = new LooseSameTypeVisitor() {
1270 @Override
1271 public Boolean visitAnnotatedType(AnnotatedType t, Type s) {
1272 if (!s.isAnnotated())
1273 return false;
1274 if (!t.getAnnotationMirrors().containsAll(s.getAnnotationMirrors()))
1275 return false;
1276 if (!s.getAnnotationMirrors().containsAll(t.getAnnotationMirrors()))
1277 return false;
1278 return visit(t.unannotatedType(), s);
1279 }
1280 };
1281 // </editor-fold>
1283 // <editor-fold defaultstate="collapsed" desc="Contains Type">
1284 public boolean containedBy(Type t, Type s) {
1285 switch (t.getTag()) {
1286 case UNDETVAR:
1287 if (s.hasTag(WILDCARD)) {
1288 UndetVar undetvar = (UndetVar)t;
1289 WildcardType wt = (WildcardType)s.unannotatedType();
1290 switch(wt.kind) {
1291 case UNBOUND: //similar to ? extends Object
1292 case EXTENDS: {
1293 Type bound = upperBound(s);
1294 undetvar.addBound(InferenceBound.UPPER, bound, this);
1295 break;
1296 }
1297 case SUPER: {
1298 Type bound = wildLowerBound(s);
1299 undetvar.addBound(InferenceBound.LOWER, bound, this);
1300 break;
1301 }
1302 }
1303 return true;
1304 } else {
1305 return isSameType(t, s);
1306 }
1307 case ERROR:
1308 return true;
1309 default:
1310 return containsType(s, t);
1311 }
1312 }
1314 boolean containsType(List<Type> ts, List<Type> ss) {
1315 while (ts.nonEmpty() && ss.nonEmpty()
1316 && containsType(ts.head, ss.head)) {
1317 ts = ts.tail;
1318 ss = ss.tail;
1319 }
1320 return ts.isEmpty() && ss.isEmpty();
1321 }
1323 /**
1324 * Check if t contains s.
1325 *
1326 * <p>T contains S if:
1327 *
1328 * <p>{@code L(T) <: L(S) && U(S) <: U(T)}
1329 *
1330 * <p>This relation is only used by ClassType.isSubtype(), that
1331 * is,
1332 *
1333 * <p>{@code C<S> <: C<T> if T contains S.}
1334 *
1335 * <p>Because of F-bounds, this relation can lead to infinite
1336 * recursion. Thus we must somehow break that recursion. Notice
1337 * that containsType() is only called from ClassType.isSubtype().
1338 * Since the arguments have already been checked against their
1339 * bounds, we know:
1340 *
1341 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)}
1342 *
1343 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)}
1344 *
1345 * @param t a type
1346 * @param s a type
1347 */
1348 public boolean containsType(Type t, Type s) {
1349 return containsType.visit(t, s);
1350 }
1351 // where
1352 private TypeRelation containsType = new TypeRelation() {
1354 private Type U(Type t) {
1355 while (t.hasTag(WILDCARD)) {
1356 WildcardType w = (WildcardType)t.unannotatedType();
1357 if (w.isSuperBound())
1358 return w.bound == null ? syms.objectType : w.bound.bound;
1359 else
1360 t = w.type;
1361 }
1362 return t;
1363 }
1365 private Type L(Type t) {
1366 while (t.hasTag(WILDCARD)) {
1367 WildcardType w = (WildcardType)t.unannotatedType();
1368 if (w.isExtendsBound())
1369 return syms.botType;
1370 else
1371 t = w.type;
1372 }
1373 return t;
1374 }
1376 public Boolean visitType(Type t, Type s) {
1377 if (s.isPartial())
1378 return containedBy(s, t);
1379 else
1380 return isSameType(t, s);
1381 }
1383 // void debugContainsType(WildcardType t, Type s) {
1384 // System.err.println();
1385 // System.err.format(" does %s contain %s?%n", t, s);
1386 // System.err.format(" %s U(%s) <: U(%s) %s = %s%n",
1387 // upperBound(s), s, t, U(t),
1388 // t.isSuperBound()
1389 // || isSubtypeNoCapture(upperBound(s), U(t)));
1390 // System.err.format(" %s L(%s) <: L(%s) %s = %s%n",
1391 // L(t), t, s, wildLowerBound(s),
1392 // t.isExtendsBound()
1393 // || isSubtypeNoCapture(L(t), wildLowerBound(s)));
1394 // System.err.println();
1395 // }
1397 @Override
1398 public Boolean visitWildcardType(WildcardType t, Type s) {
1399 if (s.isPartial())
1400 return containedBy(s, t);
1401 else {
1402 // debugContainsType(t, s);
1403 return isSameWildcard(t, s)
1404 || isCaptureOf(s, t)
1405 || ((t.isExtendsBound() || isSubtypeNoCapture(L(t), wildLowerBound(s))) &&
1406 (t.isSuperBound() || isSubtypeNoCapture(upperBound(s), U(t))));
1407 }
1408 }
1410 @Override
1411 public Boolean visitUndetVar(UndetVar t, Type s) {
1412 if (!s.hasTag(WILDCARD)) {
1413 return isSameType(t, s);
1414 } else {
1415 return false;
1416 }
1417 }
1419 @Override
1420 public Boolean visitErrorType(ErrorType t, Type s) {
1421 return true;
1422 }
1423 };
1425 public boolean isCaptureOf(Type s, WildcardType t) {
1426 if (!s.hasTag(TYPEVAR) || !((TypeVar)s.unannotatedType()).isCaptured())
1427 return false;
1428 return isSameWildcard(t, ((CapturedType)s.unannotatedType()).wildcard);
1429 }
1431 public boolean isSameWildcard(WildcardType t, Type s) {
1432 if (!s.hasTag(WILDCARD))
1433 return false;
1434 WildcardType w = (WildcardType)s.unannotatedType();
1435 return w.kind == t.kind && w.type == t.type;
1436 }
1438 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) {
1439 while (ts.nonEmpty() && ss.nonEmpty()
1440 && containsTypeEquivalent(ts.head, ss.head)) {
1441 ts = ts.tail;
1442 ss = ss.tail;
1443 }
1444 return ts.isEmpty() && ss.isEmpty();
1445 }
1446 // </editor-fold>
1448 /**
1449 * Can t and s be compared for equality? Any primitive ==
1450 * primitive or primitive == object comparisons here are an error.
1451 * Unboxing and correct primitive == primitive comparisons are
1452 * already dealt with in Attr.visitBinary.
1453 *
1454 */
1455 public boolean isEqualityComparable(Type s, Type t, Warner warn) {
1456 if (t.isNumeric() && s.isNumeric())
1457 return true;
1459 boolean tPrimitive = t.isPrimitive();
1460 boolean sPrimitive = s.isPrimitive();
1461 if (!tPrimitive && !sPrimitive) {
1462 return isCastable(s, t, warn) || isCastable(t, s, warn);
1463 } else {
1464 return false;
1465 }
1466 }
1468 // <editor-fold defaultstate="collapsed" desc="isCastable">
1469 public boolean isCastable(Type t, Type s) {
1470 return isCastable(t, s, noWarnings);
1471 }
1473 /**
1474 * Is t is castable to s?<br>
1475 * s is assumed to be an erased type.<br>
1476 * (not defined for Method and ForAll types).
1477 */
1478 public boolean isCastable(Type t, Type s, Warner warn) {
1479 if (t == s)
1480 return true;
1482 if (t.isPrimitive() != s.isPrimitive())
1483 return allowBoxing && (
1484 isConvertible(t, s, warn)
1485 || (allowObjectToPrimitiveCast &&
1486 s.isPrimitive() &&
1487 isSubtype(boxedClass(s).type, t)));
1488 if (warn != warnStack.head) {
1489 try {
1490 warnStack = warnStack.prepend(warn);
1491 checkUnsafeVarargsConversion(t, s, warn);
1492 return isCastable.visit(t,s);
1493 } finally {
1494 warnStack = warnStack.tail;
1495 }
1496 } else {
1497 return isCastable.visit(t,s);
1498 }
1499 }
1500 // where
1501 private TypeRelation isCastable = new TypeRelation() {
1503 public Boolean visitType(Type t, Type s) {
1504 if (s.hasTag(ERROR))
1505 return true;
1507 switch (t.getTag()) {
1508 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1509 case DOUBLE:
1510 return s.isNumeric();
1511 case BOOLEAN:
1512 return s.hasTag(BOOLEAN);
1513 case VOID:
1514 return false;
1515 case BOT:
1516 return isSubtype(t, s);
1517 default:
1518 throw new AssertionError();
1519 }
1520 }
1522 @Override
1523 public Boolean visitWildcardType(WildcardType t, Type s) {
1524 return isCastable(upperBound(t), s, warnStack.head);
1525 }
1527 @Override
1528 public Boolean visitClassType(ClassType t, Type s) {
1529 if (s.hasTag(ERROR) || s.hasTag(BOT))
1530 return true;
1532 if (s.hasTag(TYPEVAR)) {
1533 if (isCastable(t, s.getUpperBound(), noWarnings)) {
1534 warnStack.head.warn(LintCategory.UNCHECKED);
1535 return true;
1536 } else {
1537 return false;
1538 }
1539 }
1541 if (t.isCompound() || s.isCompound()) {
1542 return !t.isCompound() ?
1543 visitIntersectionType((IntersectionClassType)s.unannotatedType(), t, true) :
1544 visitIntersectionType((IntersectionClassType)t.unannotatedType(), s, false);
1545 }
1547 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) {
1548 boolean upcast;
1549 if ((upcast = isSubtype(erasure(t), erasure(s)))
1550 || isSubtype(erasure(s), erasure(t))) {
1551 if (!upcast && s.hasTag(ARRAY)) {
1552 if (!isReifiable(s))
1553 warnStack.head.warn(LintCategory.UNCHECKED);
1554 return true;
1555 } else if (s.isRaw()) {
1556 return true;
1557 } else if (t.isRaw()) {
1558 if (!isUnbounded(s))
1559 warnStack.head.warn(LintCategory.UNCHECKED);
1560 return true;
1561 }
1562 // Assume |a| <: |b|
1563 final Type a = upcast ? t : s;
1564 final Type b = upcast ? s : t;
1565 final boolean HIGH = true;
1566 final boolean LOW = false;
1567 final boolean DONT_REWRITE_TYPEVARS = false;
1568 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS);
1569 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS);
1570 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS);
1571 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS);
1572 Type lowSub = asSub(bLow, aLow.tsym);
1573 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1574 if (highSub == null) {
1575 final boolean REWRITE_TYPEVARS = true;
1576 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS);
1577 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS);
1578 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS);
1579 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS);
1580 lowSub = asSub(bLow, aLow.tsym);
1581 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1582 }
1583 if (highSub != null) {
1584 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) {
1585 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym);
1586 }
1587 if (!disjointTypes(aHigh.allparams(), highSub.allparams())
1588 && !disjointTypes(aHigh.allparams(), lowSub.allparams())
1589 && !disjointTypes(aLow.allparams(), highSub.allparams())
1590 && !disjointTypes(aLow.allparams(), lowSub.allparams())) {
1591 if (upcast ? giveWarning(a, b) :
1592 giveWarning(b, a))
1593 warnStack.head.warn(LintCategory.UNCHECKED);
1594 return true;
1595 }
1596 }
1597 if (isReifiable(s))
1598 return isSubtypeUnchecked(a, b);
1599 else
1600 return isSubtypeUnchecked(a, b, warnStack.head);
1601 }
1603 // Sidecast
1604 if (s.hasTag(CLASS)) {
1605 if ((s.tsym.flags() & INTERFACE) != 0) {
1606 return ((t.tsym.flags() & FINAL) == 0)
1607 ? sideCast(t, s, warnStack.head)
1608 : sideCastFinal(t, s, warnStack.head);
1609 } else if ((t.tsym.flags() & INTERFACE) != 0) {
1610 return ((s.tsym.flags() & FINAL) == 0)
1611 ? sideCast(t, s, warnStack.head)
1612 : sideCastFinal(t, s, warnStack.head);
1613 } else {
1614 // unrelated class types
1615 return false;
1616 }
1617 }
1618 }
1619 return false;
1620 }
1622 boolean visitIntersectionType(IntersectionClassType ict, Type s, boolean reverse) {
1623 Warner warn = noWarnings;
1624 for (Type c : ict.getComponents()) {
1625 warn.clear();
1626 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn))
1627 return false;
1628 }
1629 if (warn.hasLint(LintCategory.UNCHECKED))
1630 warnStack.head.warn(LintCategory.UNCHECKED);
1631 return true;
1632 }
1634 @Override
1635 public Boolean visitArrayType(ArrayType t, Type s) {
1636 switch (s.getTag()) {
1637 case ERROR:
1638 case BOT:
1639 return true;
1640 case TYPEVAR:
1641 if (isCastable(s, t, noWarnings)) {
1642 warnStack.head.warn(LintCategory.UNCHECKED);
1643 return true;
1644 } else {
1645 return false;
1646 }
1647 case CLASS:
1648 return isSubtype(t, s);
1649 case ARRAY:
1650 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) {
1651 return elemtype(t).hasTag(elemtype(s).getTag());
1652 } else {
1653 return visit(elemtype(t), elemtype(s));
1654 }
1655 default:
1656 return false;
1657 }
1658 }
1660 @Override
1661 public Boolean visitTypeVar(TypeVar t, Type s) {
1662 switch (s.getTag()) {
1663 case ERROR:
1664 case BOT:
1665 return true;
1666 case TYPEVAR:
1667 if (isSubtype(t, s)) {
1668 return true;
1669 } else if (isCastable(t.bound, s, noWarnings)) {
1670 warnStack.head.warn(LintCategory.UNCHECKED);
1671 return true;
1672 } else {
1673 return false;
1674 }
1675 default:
1676 return isCastable(t.bound, s, warnStack.head);
1677 }
1678 }
1680 @Override
1681 public Boolean visitErrorType(ErrorType t, Type s) {
1682 return true;
1683 }
1684 };
1685 // </editor-fold>
1687 // <editor-fold defaultstate="collapsed" desc="disjointTypes">
1688 public boolean disjointTypes(List<Type> ts, List<Type> ss) {
1689 while (ts.tail != null && ss.tail != null) {
1690 if (disjointType(ts.head, ss.head)) return true;
1691 ts = ts.tail;
1692 ss = ss.tail;
1693 }
1694 return false;
1695 }
1697 /**
1698 * Two types or wildcards are considered disjoint if it can be
1699 * proven that no type can be contained in both. It is
1700 * conservative in that it is allowed to say that two types are
1701 * not disjoint, even though they actually are.
1702 *
1703 * The type {@code C<X>} is castable to {@code C<Y>} exactly if
1704 * {@code X} and {@code Y} are not disjoint.
1705 */
1706 public boolean disjointType(Type t, Type s) {
1707 return disjointType.visit(t, s);
1708 }
1709 // where
1710 private TypeRelation disjointType = new TypeRelation() {
1712 private Set<TypePair> cache = new HashSet<TypePair>();
1714 @Override
1715 public Boolean visitType(Type t, Type s) {
1716 if (s.hasTag(WILDCARD))
1717 return visit(s, t);
1718 else
1719 return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t);
1720 }
1722 private boolean isCastableRecursive(Type t, Type s) {
1723 TypePair pair = new TypePair(t, s);
1724 if (cache.add(pair)) {
1725 try {
1726 return Types.this.isCastable(t, s);
1727 } finally {
1728 cache.remove(pair);
1729 }
1730 } else {
1731 return true;
1732 }
1733 }
1735 private boolean notSoftSubtypeRecursive(Type t, Type s) {
1736 TypePair pair = new TypePair(t, s);
1737 if (cache.add(pair)) {
1738 try {
1739 return Types.this.notSoftSubtype(t, s);
1740 } finally {
1741 cache.remove(pair);
1742 }
1743 } else {
1744 return false;
1745 }
1746 }
1748 @Override
1749 public Boolean visitWildcardType(WildcardType t, Type s) {
1750 if (t.isUnbound())
1751 return false;
1753 if (!s.hasTag(WILDCARD)) {
1754 if (t.isExtendsBound())
1755 return notSoftSubtypeRecursive(s, t.type);
1756 else
1757 return notSoftSubtypeRecursive(t.type, s);
1758 }
1760 if (s.isUnbound())
1761 return false;
1763 if (t.isExtendsBound()) {
1764 if (s.isExtendsBound())
1765 return !isCastableRecursive(t.type, upperBound(s));
1766 else if (s.isSuperBound())
1767 return notSoftSubtypeRecursive(wildLowerBound(s), t.type);
1768 } else if (t.isSuperBound()) {
1769 if (s.isExtendsBound())
1770 return notSoftSubtypeRecursive(t.type, upperBound(s));
1771 }
1772 return false;
1773 }
1774 };
1775 // </editor-fold>
1777 // <editor-fold defaultstate="collapsed" desc="cvarLowerBounds">
1778 public List<Type> cvarLowerBounds(List<Type> ts) {
1779 return map(ts, cvarLowerBoundMapping);
1780 }
1781 private final Mapping cvarLowerBoundMapping = new Mapping("cvarLowerBound") {
1782 public Type apply(Type t) {
1783 return cvarLowerBound(t);
1784 }
1785 };
1786 // </editor-fold>
1788 // <editor-fold defaultstate="collapsed" desc="notSoftSubtype">
1789 /**
1790 * This relation answers the question: is impossible that
1791 * something of type `t' can be a subtype of `s'? This is
1792 * different from the question "is `t' not a subtype of `s'?"
1793 * when type variables are involved: Integer is not a subtype of T
1794 * where {@code <T extends Number>} but it is not true that Integer cannot
1795 * possibly be a subtype of T.
1796 */
1797 public boolean notSoftSubtype(Type t, Type s) {
1798 if (t == s) return false;
1799 if (t.hasTag(TYPEVAR)) {
1800 TypeVar tv = (TypeVar) t;
1801 return !isCastable(tv.bound,
1802 relaxBound(s),
1803 noWarnings);
1804 }
1805 if (!s.hasTag(WILDCARD))
1806 s = upperBound(s);
1808 return !isSubtype(t, relaxBound(s));
1809 }
1811 private Type relaxBound(Type t) {
1812 if (t.hasTag(TYPEVAR)) {
1813 while (t.hasTag(TYPEVAR))
1814 t = t.getUpperBound();
1815 t = rewriteQuantifiers(t, true, true);
1816 }
1817 return t;
1818 }
1819 // </editor-fold>
1821 // <editor-fold defaultstate="collapsed" desc="isReifiable">
1822 public boolean isReifiable(Type t) {
1823 return isReifiable.visit(t);
1824 }
1825 // where
1826 private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() {
1828 public Boolean visitType(Type t, Void ignored) {
1829 return true;
1830 }
1832 @Override
1833 public Boolean visitClassType(ClassType t, Void ignored) {
1834 if (t.isCompound())
1835 return false;
1836 else {
1837 if (!t.isParameterized())
1838 return true;
1840 for (Type param : t.allparams()) {
1841 if (!param.isUnbound())
1842 return false;
1843 }
1844 return true;
1845 }
1846 }
1848 @Override
1849 public Boolean visitArrayType(ArrayType t, Void ignored) {
1850 return visit(t.elemtype);
1851 }
1853 @Override
1854 public Boolean visitTypeVar(TypeVar t, Void ignored) {
1855 return false;
1856 }
1857 };
1858 // </editor-fold>
1860 // <editor-fold defaultstate="collapsed" desc="Array Utils">
1861 public boolean isArray(Type t) {
1862 while (t.hasTag(WILDCARD))
1863 t = upperBound(t);
1864 return t.hasTag(ARRAY);
1865 }
1867 /**
1868 * The element type of an array.
1869 */
1870 public Type elemtype(Type t) {
1871 switch (t.getTag()) {
1872 case WILDCARD:
1873 return elemtype(upperBound(t));
1874 case ARRAY:
1875 t = t.unannotatedType();
1876 return ((ArrayType)t).elemtype;
1877 case FORALL:
1878 return elemtype(((ForAll)t).qtype);
1879 case ERROR:
1880 return t;
1881 default:
1882 return null;
1883 }
1884 }
1886 public Type elemtypeOrType(Type t) {
1887 Type elemtype = elemtype(t);
1888 return elemtype != null ?
1889 elemtype :
1890 t;
1891 }
1893 /**
1894 * Mapping to take element type of an arraytype
1895 */
1896 private Mapping elemTypeFun = new Mapping ("elemTypeFun") {
1897 public Type apply(Type t) { return elemtype(t); }
1898 };
1900 /**
1901 * The number of dimensions of an array type.
1902 */
1903 public int dimensions(Type t) {
1904 int result = 0;
1905 while (t.hasTag(ARRAY)) {
1906 result++;
1907 t = elemtype(t);
1908 }
1909 return result;
1910 }
1912 /**
1913 * Returns an ArrayType with the component type t
1914 *
1915 * @param t The component type of the ArrayType
1916 * @return the ArrayType for the given component
1917 */
1918 public ArrayType makeArrayType(Type t) {
1919 if (t.hasTag(VOID) || t.hasTag(PACKAGE)) {
1920 Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString());
1921 }
1922 return new ArrayType(t, syms.arrayClass);
1923 }
1924 // </editor-fold>
1926 // <editor-fold defaultstate="collapsed" desc="asSuper">
1927 /**
1928 * Return the (most specific) base type of t that starts with the
1929 * given symbol. If none exists, return null.
1930 *
1931 * @param t a type
1932 * @param sym a symbol
1933 */
1934 public Type asSuper(Type t, Symbol sym) {
1935 /* Some examples:
1936 *
1937 * (Enum<E>, Comparable) => Comparable<E>
1938 * (c.s.s.d.AttributeTree.ValueKind, Enum) => Enum<c.s.s.d.AttributeTree.ValueKind>
1939 * (c.s.s.t.ExpressionTree, c.s.s.t.Tree) => c.s.s.t.Tree
1940 * (j.u.List<capture#160 of ? extends c.s.s.d.DocTree>, Iterable) =>
1941 * Iterable<capture#160 of ? extends c.s.s.d.DocTree>
1942 */
1943 if (sym.type == syms.objectType) { //optimization
1944 return syms.objectType;
1945 }
1946 return asSuper.visit(t, sym);
1947 }
1948 // where
1949 private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() {
1951 public Type visitType(Type t, Symbol sym) {
1952 return null;
1953 }
1955 @Override
1956 public Type visitClassType(ClassType t, Symbol sym) {
1957 if (t.tsym == sym)
1958 return t;
1960 Type st = supertype(t);
1961 if (st.hasTag(CLASS) || st.hasTag(TYPEVAR)) {
1962 Type x = asSuper(st, sym);
1963 if (x != null)
1964 return x;
1965 }
1966 if ((sym.flags() & INTERFACE) != 0) {
1967 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
1968 if (!l.head.hasTag(ERROR)) {
1969 Type x = asSuper(l.head, sym);
1970 if (x != null)
1971 return x;
1972 }
1973 }
1974 }
1975 return null;
1976 }
1978 @Override
1979 public Type visitArrayType(ArrayType t, Symbol sym) {
1980 return isSubtype(t, sym.type) ? sym.type : null;
1981 }
1983 @Override
1984 public Type visitTypeVar(TypeVar t, Symbol sym) {
1985 if (t.tsym == sym)
1986 return t;
1987 else
1988 return asSuper(t.bound, sym);
1989 }
1991 @Override
1992 public Type visitErrorType(ErrorType t, Symbol sym) {
1993 return t;
1994 }
1995 };
1997 /**
1998 * Return the base type of t or any of its outer types that starts
1999 * with the given symbol. If none exists, return null.
2000 *
2001 * @param t a type
2002 * @param sym a symbol
2003 */
2004 public Type asOuterSuper(Type t, Symbol sym) {
2005 switch (t.getTag()) {
2006 case CLASS:
2007 do {
2008 Type s = asSuper(t, sym);
2009 if (s != null) return s;
2010 t = t.getEnclosingType();
2011 } while (t.hasTag(CLASS));
2012 return null;
2013 case ARRAY:
2014 return isSubtype(t, sym.type) ? sym.type : null;
2015 case TYPEVAR:
2016 return asSuper(t, sym);
2017 case ERROR:
2018 return t;
2019 default:
2020 return null;
2021 }
2022 }
2024 /**
2025 * Return the base type of t or any of its enclosing types that
2026 * starts with the given symbol. If none exists, return null.
2027 *
2028 * @param t a type
2029 * @param sym a symbol
2030 */
2031 public Type asEnclosingSuper(Type t, Symbol sym) {
2032 switch (t.getTag()) {
2033 case CLASS:
2034 do {
2035 Type s = asSuper(t, sym);
2036 if (s != null) return s;
2037 Type outer = t.getEnclosingType();
2038 t = (outer.hasTag(CLASS)) ? outer :
2039 (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type :
2040 Type.noType;
2041 } while (t.hasTag(CLASS));
2042 return null;
2043 case ARRAY:
2044 return isSubtype(t, sym.type) ? sym.type : null;
2045 case TYPEVAR:
2046 return asSuper(t, sym);
2047 case ERROR:
2048 return t;
2049 default:
2050 return null;
2051 }
2052 }
2053 // </editor-fold>
2055 // <editor-fold defaultstate="collapsed" desc="memberType">
2056 /**
2057 * The type of given symbol, seen as a member of t.
2058 *
2059 * @param t a type
2060 * @param sym a symbol
2061 */
2062 public Type memberType(Type t, Symbol sym) {
2063 return (sym.flags() & STATIC) != 0
2064 ? sym.type
2065 : memberType.visit(t, sym);
2066 }
2067 // where
2068 private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() {
2070 public Type visitType(Type t, Symbol sym) {
2071 return sym.type;
2072 }
2074 @Override
2075 public Type visitWildcardType(WildcardType t, Symbol sym) {
2076 return memberType(upperBound(t), sym);
2077 }
2079 @Override
2080 public Type visitClassType(ClassType t, Symbol sym) {
2081 Symbol owner = sym.owner;
2082 long flags = sym.flags();
2083 if (((flags & STATIC) == 0) && owner.type.isParameterized()) {
2084 Type base = asOuterSuper(t, owner);
2085 //if t is an intersection type T = CT & I1 & I2 ... & In
2086 //its supertypes CT, I1, ... In might contain wildcards
2087 //so we need to go through capture conversion
2088 base = t.isCompound() ? capture(base) : base;
2089 if (base != null) {
2090 List<Type> ownerParams = owner.type.allparams();
2091 List<Type> baseParams = base.allparams();
2092 if (ownerParams.nonEmpty()) {
2093 if (baseParams.isEmpty()) {
2094 // then base is a raw type
2095 return erasure(sym.type);
2096 } else {
2097 return subst(sym.type, ownerParams, baseParams);
2098 }
2099 }
2100 }
2101 }
2102 return sym.type;
2103 }
2105 @Override
2106 public Type visitTypeVar(TypeVar t, Symbol sym) {
2107 return memberType(t.bound, sym);
2108 }
2110 @Override
2111 public Type visitErrorType(ErrorType t, Symbol sym) {
2112 return t;
2113 }
2114 };
2115 // </editor-fold>
2117 // <editor-fold defaultstate="collapsed" desc="isAssignable">
2118 public boolean isAssignable(Type t, Type s) {
2119 return isAssignable(t, s, noWarnings);
2120 }
2122 /**
2123 * Is t assignable to s?<br>
2124 * Equivalent to subtype except for constant values and raw
2125 * types.<br>
2126 * (not defined for Method and ForAll types)
2127 */
2128 public boolean isAssignable(Type t, Type s, Warner warn) {
2129 if (t.hasTag(ERROR))
2130 return true;
2131 if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) {
2132 int value = ((Number)t.constValue()).intValue();
2133 switch (s.getTag()) {
2134 case BYTE:
2135 if (Byte.MIN_VALUE <= value && value <= Byte.MAX_VALUE)
2136 return true;
2137 break;
2138 case CHAR:
2139 if (Character.MIN_VALUE <= value && value <= Character.MAX_VALUE)
2140 return true;
2141 break;
2142 case SHORT:
2143 if (Short.MIN_VALUE <= value && value <= Short.MAX_VALUE)
2144 return true;
2145 break;
2146 case INT:
2147 return true;
2148 case CLASS:
2149 switch (unboxedType(s).getTag()) {
2150 case BYTE:
2151 case CHAR:
2152 case SHORT:
2153 return isAssignable(t, unboxedType(s), warn);
2154 }
2155 break;
2156 }
2157 }
2158 return isConvertible(t, s, warn);
2159 }
2160 // </editor-fold>
2162 // <editor-fold defaultstate="collapsed" desc="erasure">
2163 /**
2164 * The erasure of t {@code |t|} -- the type that results when all
2165 * type parameters in t are deleted.
2166 */
2167 public Type erasure(Type t) {
2168 return eraseNotNeeded(t)? t : erasure(t, false);
2169 }
2170 //where
2171 private boolean eraseNotNeeded(Type t) {
2172 // We don't want to erase primitive types and String type as that
2173 // operation is idempotent. Also, erasing these could result in loss
2174 // of information such as constant values attached to such types.
2175 return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym);
2176 }
2178 private Type erasure(Type t, boolean recurse) {
2179 if (t.isPrimitive())
2180 return t; /* fast special case */
2181 else
2182 return erasure.visit(t, recurse);
2183 }
2184 // where
2185 private SimpleVisitor<Type, Boolean> erasure = new SimpleVisitor<Type, Boolean>() {
2186 public Type visitType(Type t, Boolean recurse) {
2187 if (t.isPrimitive())
2188 return t; /*fast special case*/
2189 else
2190 return t.map(recurse ? erasureRecFun : erasureFun);
2191 }
2193 @Override
2194 public Type visitWildcardType(WildcardType t, Boolean recurse) {
2195 return erasure(upperBound(t), recurse);
2196 }
2198 @Override
2199 public Type visitClassType(ClassType t, Boolean recurse) {
2200 Type erased = t.tsym.erasure(Types.this);
2201 if (recurse) {
2202 erased = new ErasedClassType(erased.getEnclosingType(),erased.tsym);
2203 }
2204 return erased;
2205 }
2207 @Override
2208 public Type visitTypeVar(TypeVar t, Boolean recurse) {
2209 return erasure(t.bound, recurse);
2210 }
2212 @Override
2213 public Type visitErrorType(ErrorType t, Boolean recurse) {
2214 return t;
2215 }
2217 @Override
2218 public Type visitAnnotatedType(AnnotatedType t, Boolean recurse) {
2219 Type erased = erasure(t.unannotatedType(), recurse);
2220 if (erased.isAnnotated()) {
2221 // This can only happen when the underlying type is a
2222 // type variable and the upper bound of it is annotated.
2223 // The annotation on the type variable overrides the one
2224 // on the bound.
2225 erased = ((AnnotatedType)erased).unannotatedType();
2226 }
2227 return erased.annotatedType(t.getAnnotationMirrors());
2228 }
2229 };
2231 private Mapping erasureFun = new Mapping ("erasure") {
2232 public Type apply(Type t) { return erasure(t); }
2233 };
2235 private Mapping erasureRecFun = new Mapping ("erasureRecursive") {
2236 public Type apply(Type t) { return erasureRecursive(t); }
2237 };
2239 public List<Type> erasure(List<Type> ts) {
2240 return Type.map(ts, erasureFun);
2241 }
2243 public Type erasureRecursive(Type t) {
2244 return erasure(t, true);
2245 }
2247 public List<Type> erasureRecursive(List<Type> ts) {
2248 return Type.map(ts, erasureRecFun);
2249 }
2250 // </editor-fold>
2252 // <editor-fold defaultstate="collapsed" desc="makeCompoundType">
2253 /**
2254 * Make a compound type from non-empty list of types. The list should be
2255 * ordered according to {@link Symbol#precedes(TypeSymbol,Types)}.
2256 *
2257 * @param bounds the types from which the compound type is formed
2258 * @param supertype is objectType if all bounds are interfaces,
2259 * null otherwise.
2260 */
2261 public Type makeCompoundType(List<Type> bounds) {
2262 return makeCompoundType(bounds, bounds.head.tsym.isInterface());
2263 }
2264 public Type makeCompoundType(List<Type> bounds, boolean allInterfaces) {
2265 Assert.check(bounds.nonEmpty());
2266 Type firstExplicitBound = bounds.head;
2267 if (allInterfaces) {
2268 bounds = bounds.prepend(syms.objectType);
2269 }
2270 ClassSymbol bc =
2271 new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC,
2272 Type.moreInfo
2273 ? names.fromString(bounds.toString())
2274 : names.empty,
2275 null,
2276 syms.noSymbol);
2277 bc.type = new IntersectionClassType(bounds, bc, allInterfaces);
2278 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ?
2279 syms.objectType : // error condition, recover
2280 erasure(firstExplicitBound);
2281 bc.members_field = new Scope(bc);
2282 return bc.type;
2283 }
2285 /**
2286 * A convenience wrapper for {@link #makeCompoundType(List)}; the
2287 * arguments are converted to a list and passed to the other
2288 * method. Note that this might cause a symbol completion.
2289 * Hence, this version of makeCompoundType may not be called
2290 * during a classfile read.
2291 */
2292 public Type makeCompoundType(Type bound1, Type bound2) {
2293 return makeCompoundType(List.of(bound1, bound2));
2294 }
2295 // </editor-fold>
2297 // <editor-fold defaultstate="collapsed" desc="supertype">
2298 public Type supertype(Type t) {
2299 return supertype.visit(t);
2300 }
2301 // where
2302 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() {
2304 public Type visitType(Type t, Void ignored) {
2305 // A note on wildcards: there is no good way to
2306 // determine a supertype for a super bounded wildcard.
2307 return null;
2308 }
2310 @Override
2311 public Type visitClassType(ClassType t, Void ignored) {
2312 if (t.supertype_field == null) {
2313 Type supertype = ((ClassSymbol)t.tsym).getSuperclass();
2314 // An interface has no superclass; its supertype is Object.
2315 if (t.isInterface())
2316 supertype = ((ClassType)t.tsym.type).supertype_field;
2317 if (t.supertype_field == null) {
2318 List<Type> actuals = classBound(t).allparams();
2319 List<Type> formals = t.tsym.type.allparams();
2320 if (t.hasErasedSupertypes()) {
2321 t.supertype_field = erasureRecursive(supertype);
2322 } else if (formals.nonEmpty()) {
2323 t.supertype_field = subst(supertype, formals, actuals);
2324 }
2325 else {
2326 t.supertype_field = supertype;
2327 }
2328 }
2329 }
2330 return t.supertype_field;
2331 }
2333 /**
2334 * The supertype is always a class type. If the type
2335 * variable's bounds start with a class type, this is also
2336 * the supertype. Otherwise, the supertype is
2337 * java.lang.Object.
2338 */
2339 @Override
2340 public Type visitTypeVar(TypeVar t, Void ignored) {
2341 if (t.bound.hasTag(TYPEVAR) ||
2342 (!t.bound.isCompound() && !t.bound.isInterface())) {
2343 return t.bound;
2344 } else {
2345 return supertype(t.bound);
2346 }
2347 }
2349 @Override
2350 public Type visitArrayType(ArrayType t, Void ignored) {
2351 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType))
2352 return arraySuperType();
2353 else
2354 return new ArrayType(supertype(t.elemtype), t.tsym);
2355 }
2357 @Override
2358 public Type visitErrorType(ErrorType t, Void ignored) {
2359 return Type.noType;
2360 }
2361 };
2362 // </editor-fold>
2364 // <editor-fold defaultstate="collapsed" desc="interfaces">
2365 /**
2366 * Return the interfaces implemented by this class.
2367 */
2368 public List<Type> interfaces(Type t) {
2369 return interfaces.visit(t);
2370 }
2371 // where
2372 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() {
2374 public List<Type> visitType(Type t, Void ignored) {
2375 return List.nil();
2376 }
2378 @Override
2379 public List<Type> visitClassType(ClassType t, Void ignored) {
2380 if (t.interfaces_field == null) {
2381 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces();
2382 if (t.interfaces_field == null) {
2383 // If t.interfaces_field is null, then t must
2384 // be a parameterized type (not to be confused
2385 // with a generic type declaration).
2386 // Terminology:
2387 // Parameterized type: List<String>
2388 // Generic type declaration: class List<E> { ... }
2389 // So t corresponds to List<String> and
2390 // t.tsym.type corresponds to List<E>.
2391 // The reason t must be parameterized type is
2392 // that completion will happen as a side
2393 // effect of calling
2394 // ClassSymbol.getInterfaces. Since
2395 // t.interfaces_field is null after
2396 // completion, we can assume that t is not the
2397 // type of a class/interface declaration.
2398 Assert.check(t != t.tsym.type, t);
2399 List<Type> actuals = t.allparams();
2400 List<Type> formals = t.tsym.type.allparams();
2401 if (t.hasErasedSupertypes()) {
2402 t.interfaces_field = erasureRecursive(interfaces);
2403 } else if (formals.nonEmpty()) {
2404 t.interfaces_field =
2405 upperBounds(subst(interfaces, formals, actuals));
2406 }
2407 else {
2408 t.interfaces_field = interfaces;
2409 }
2410 }
2411 }
2412 return t.interfaces_field;
2413 }
2415 @Override
2416 public List<Type> visitTypeVar(TypeVar t, Void ignored) {
2417 if (t.bound.isCompound())
2418 return interfaces(t.bound);
2420 if (t.bound.isInterface())
2421 return List.of(t.bound);
2423 return List.nil();
2424 }
2425 };
2427 public List<Type> directSupertypes(Type t) {
2428 return directSupertypes.visit(t);
2429 }
2430 // where
2431 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() {
2433 public List<Type> visitType(final Type type, final Void ignored) {
2434 if (!type.isCompound()) {
2435 final Type sup = supertype(type);
2436 return (sup == Type.noType || sup == type || sup == null)
2437 ? interfaces(type)
2438 : interfaces(type).prepend(sup);
2439 } else {
2440 return visitIntersectionType((IntersectionClassType) type);
2441 }
2442 }
2444 private List<Type> visitIntersectionType(final IntersectionClassType it) {
2445 return it.getExplicitComponents();
2446 }
2448 };
2450 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) {
2451 for (Type i2 : interfaces(origin.type)) {
2452 if (isym == i2.tsym) return true;
2453 }
2454 return false;
2455 }
2456 // </editor-fold>
2458 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw">
2459 Map<Type,Boolean> isDerivedRawCache = new HashMap<Type,Boolean>();
2461 public boolean isDerivedRaw(Type t) {
2462 Boolean result = isDerivedRawCache.get(t);
2463 if (result == null) {
2464 result = isDerivedRawInternal(t);
2465 isDerivedRawCache.put(t, result);
2466 }
2467 return result;
2468 }
2470 public boolean isDerivedRawInternal(Type t) {
2471 if (t.isErroneous())
2472 return false;
2473 return
2474 t.isRaw() ||
2475 supertype(t) != null && isDerivedRaw(supertype(t)) ||
2476 isDerivedRaw(interfaces(t));
2477 }
2479 public boolean isDerivedRaw(List<Type> ts) {
2480 List<Type> l = ts;
2481 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail;
2482 return l.nonEmpty();
2483 }
2484 // </editor-fold>
2486 // <editor-fold defaultstate="collapsed" desc="setBounds">
2487 /**
2488 * Set the bounds field of the given type variable to reflect a
2489 * (possibly multiple) list of bounds.
2490 * @param t a type variable
2491 * @param bounds the bounds, must be nonempty
2492 * @param supertype is objectType if all bounds are interfaces,
2493 * null otherwise.
2494 */
2495 public void setBounds(TypeVar t, List<Type> bounds) {
2496 setBounds(t, bounds, bounds.head.tsym.isInterface());
2497 }
2499 /**
2500 * Same as {@link #setBounds(Type.TypeVar,List,Type)}, except that
2501 * third parameter is computed directly, as follows: if all
2502 * all bounds are interface types, the computed supertype is Object,
2503 * otherwise the supertype is simply left null (in this case, the supertype
2504 * is assumed to be the head of the bound list passed as second argument).
2505 * Note that this check might cause a symbol completion. Hence, this version of
2506 * setBounds may not be called during a classfile read.
2507 */
2508 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) {
2509 t.bound = bounds.tail.isEmpty() ?
2510 bounds.head :
2511 makeCompoundType(bounds, allInterfaces);
2512 t.rank_field = -1;
2513 }
2514 // </editor-fold>
2516 // <editor-fold defaultstate="collapsed" desc="getBounds">
2517 /**
2518 * Return list of bounds of the given type variable.
2519 */
2520 public List<Type> getBounds(TypeVar t) {
2521 if (t.bound.hasTag(NONE))
2522 return List.nil();
2523 else if (t.bound.isErroneous() || !t.bound.isCompound())
2524 return List.of(t.bound);
2525 else if ((erasure(t).tsym.flags() & INTERFACE) == 0)
2526 return interfaces(t).prepend(supertype(t));
2527 else
2528 // No superclass was given in bounds.
2529 // In this case, supertype is Object, erasure is first interface.
2530 return interfaces(t);
2531 }
2532 // </editor-fold>
2534 // <editor-fold defaultstate="collapsed" desc="classBound">
2535 /**
2536 * If the given type is a (possibly selected) type variable,
2537 * return the bounding class of this type, otherwise return the
2538 * type itself.
2539 */
2540 public Type classBound(Type t) {
2541 return classBound.visit(t);
2542 }
2543 // where
2544 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() {
2546 public Type visitType(Type t, Void ignored) {
2547 return t;
2548 }
2550 @Override
2551 public Type visitClassType(ClassType t, Void ignored) {
2552 Type outer1 = classBound(t.getEnclosingType());
2553 if (outer1 != t.getEnclosingType())
2554 return new ClassType(outer1, t.getTypeArguments(), t.tsym);
2555 else
2556 return t;
2557 }
2559 @Override
2560 public Type visitTypeVar(TypeVar t, Void ignored) {
2561 return classBound(supertype(t));
2562 }
2564 @Override
2565 public Type visitErrorType(ErrorType t, Void ignored) {
2566 return t;
2567 }
2568 };
2569 // </editor-fold>
2571 // <editor-fold defaultstate="collapsed" desc="sub signature / override equivalence">
2572 /**
2573 * Returns true iff the first signature is a <em>sub
2574 * signature</em> of the other. This is <b>not</b> an equivalence
2575 * relation.
2576 *
2577 * @jls section 8.4.2.
2578 * @see #overrideEquivalent(Type t, Type s)
2579 * @param t first signature (possibly raw).
2580 * @param s second signature (could be subjected to erasure).
2581 * @return true if t is a sub signature of s.
2582 */
2583 public boolean isSubSignature(Type t, Type s) {
2584 return isSubSignature(t, s, true);
2585 }
2587 public boolean isSubSignature(Type t, Type s, boolean strict) {
2588 return hasSameArgs(t, s, strict) || hasSameArgs(t, erasure(s), strict);
2589 }
2591 /**
2592 * Returns true iff these signatures are related by <em>override
2593 * equivalence</em>. This is the natural extension of
2594 * isSubSignature to an equivalence relation.
2595 *
2596 * @jls section 8.4.2.
2597 * @see #isSubSignature(Type t, Type s)
2598 * @param t a signature (possible raw, could be subjected to
2599 * erasure).
2600 * @param s a signature (possible raw, could be subjected to
2601 * erasure).
2602 * @return true if either argument is a sub signature of the other.
2603 */
2604 public boolean overrideEquivalent(Type t, Type s) {
2605 return hasSameArgs(t, s) ||
2606 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s);
2607 }
2609 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) {
2610 for (Scope.Entry e = syms.objectType.tsym.members().lookup(msym.name) ; e.scope != null ; e = e.next()) {
2611 if (msym.overrides(e.sym, origin, Types.this, true)) {
2612 return true;
2613 }
2614 }
2615 return false;
2616 }
2618 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site">
2619 class ImplementationCache {
2621 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map =
2622 new WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>>();
2624 class Entry {
2625 final MethodSymbol cachedImpl;
2626 final Filter<Symbol> implFilter;
2627 final boolean checkResult;
2628 final int prevMark;
2630 public Entry(MethodSymbol cachedImpl,
2631 Filter<Symbol> scopeFilter,
2632 boolean checkResult,
2633 int prevMark) {
2634 this.cachedImpl = cachedImpl;
2635 this.implFilter = scopeFilter;
2636 this.checkResult = checkResult;
2637 this.prevMark = prevMark;
2638 }
2640 boolean matches(Filter<Symbol> scopeFilter, boolean checkResult, int mark) {
2641 return this.implFilter == scopeFilter &&
2642 this.checkResult == checkResult &&
2643 this.prevMark == mark;
2644 }
2645 }
2647 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2648 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms);
2649 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null;
2650 if (cache == null) {
2651 cache = new HashMap<TypeSymbol, Entry>();
2652 _map.put(ms, new SoftReference<Map<TypeSymbol, Entry>>(cache));
2653 }
2654 Entry e = cache.get(origin);
2655 CompoundScope members = membersClosure(origin.type, true);
2656 if (e == null ||
2657 !e.matches(implFilter, checkResult, members.getMark())) {
2658 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter);
2659 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark()));
2660 return impl;
2661 }
2662 else {
2663 return e.cachedImpl;
2664 }
2665 }
2667 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2668 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) {
2669 while (t.hasTag(TYPEVAR))
2670 t = t.getUpperBound();
2671 TypeSymbol c = t.tsym;
2672 for (Scope.Entry e = c.members().lookup(ms.name, implFilter);
2673 e.scope != null;
2674 e = e.next(implFilter)) {
2675 if (e.sym != null &&
2676 e.sym.overrides(ms, origin, Types.this, checkResult))
2677 return (MethodSymbol)e.sym;
2678 }
2679 }
2680 return null;
2681 }
2682 }
2684 private ImplementationCache implCache = new ImplementationCache();
2686 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2687 return implCache.get(ms, origin, checkResult, implFilter);
2688 }
2689 // </editor-fold>
2691 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site">
2692 class MembersClosureCache extends SimpleVisitor<CompoundScope, Boolean> {
2694 private WeakHashMap<TypeSymbol, Entry> _map =
2695 new WeakHashMap<TypeSymbol, Entry>();
2697 class Entry {
2698 final boolean skipInterfaces;
2699 final CompoundScope compoundScope;
2701 public Entry(boolean skipInterfaces, CompoundScope compoundScope) {
2702 this.skipInterfaces = skipInterfaces;
2703 this.compoundScope = compoundScope;
2704 }
2706 boolean matches(boolean skipInterfaces) {
2707 return this.skipInterfaces == skipInterfaces;
2708 }
2709 }
2711 List<TypeSymbol> seenTypes = List.nil();
2713 /** members closure visitor methods **/
2715 public CompoundScope visitType(Type t, Boolean skipInterface) {
2716 return null;
2717 }
2719 @Override
2720 public CompoundScope visitClassType(ClassType t, Boolean skipInterface) {
2721 if (seenTypes.contains(t.tsym)) {
2722 //this is possible when an interface is implemented in multiple
2723 //superclasses, or when a classs hierarchy is circular - in such
2724 //cases we don't need to recurse (empty scope is returned)
2725 return new CompoundScope(t.tsym);
2726 }
2727 try {
2728 seenTypes = seenTypes.prepend(t.tsym);
2729 ClassSymbol csym = (ClassSymbol)t.tsym;
2730 Entry e = _map.get(csym);
2731 if (e == null || !e.matches(skipInterface)) {
2732 CompoundScope membersClosure = new CompoundScope(csym);
2733 if (!skipInterface) {
2734 for (Type i : interfaces(t)) {
2735 membersClosure.addSubScope(visit(i, skipInterface));
2736 }
2737 }
2738 membersClosure.addSubScope(visit(supertype(t), skipInterface));
2739 membersClosure.addSubScope(csym.members());
2740 e = new Entry(skipInterface, membersClosure);
2741 _map.put(csym, e);
2742 }
2743 return e.compoundScope;
2744 }
2745 finally {
2746 seenTypes = seenTypes.tail;
2747 }
2748 }
2750 @Override
2751 public CompoundScope visitTypeVar(TypeVar t, Boolean skipInterface) {
2752 return visit(t.getUpperBound(), skipInterface);
2753 }
2754 }
2756 private MembersClosureCache membersCache = new MembersClosureCache();
2758 public CompoundScope membersClosure(Type site, boolean skipInterface) {
2759 return membersCache.visit(site, skipInterface);
2760 }
2761 // </editor-fold>
2764 //where
2765 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) {
2766 Filter<Symbol> filter = new MethodFilter(ms, site);
2767 List<MethodSymbol> candidates = List.nil();
2768 for (Symbol s : membersClosure(site, false).getElements(filter)) {
2769 if (!site.tsym.isInterface() && !s.owner.isInterface()) {
2770 return List.of((MethodSymbol)s);
2771 } else if (!candidates.contains(s)) {
2772 candidates = candidates.prepend((MethodSymbol)s);
2773 }
2774 }
2775 return prune(candidates);
2776 }
2778 public List<MethodSymbol> prune(List<MethodSymbol> methods) {
2779 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>();
2780 for (MethodSymbol m1 : methods) {
2781 boolean isMin_m1 = true;
2782 for (MethodSymbol m2 : methods) {
2783 if (m1 == m2) continue;
2784 if (m2.owner != m1.owner &&
2785 asSuper(m2.owner.type, m1.owner) != null) {
2786 isMin_m1 = false;
2787 break;
2788 }
2789 }
2790 if (isMin_m1)
2791 methodsMin.append(m1);
2792 }
2793 return methodsMin.toList();
2794 }
2795 // where
2796 private class MethodFilter implements Filter<Symbol> {
2798 Symbol msym;
2799 Type site;
2801 MethodFilter(Symbol msym, Type site) {
2802 this.msym = msym;
2803 this.site = site;
2804 }
2806 public boolean accepts(Symbol s) {
2807 return s.kind == Kinds.MTH &&
2808 s.name == msym.name &&
2809 (s.flags() & SYNTHETIC) == 0 &&
2810 s.isInheritedIn(site.tsym, Types.this) &&
2811 overrideEquivalent(memberType(site, s), memberType(site, msym));
2812 }
2813 };
2814 // </editor-fold>
2816 /**
2817 * Does t have the same arguments as s? It is assumed that both
2818 * types are (possibly polymorphic) method types. Monomorphic
2819 * method types "have the same arguments", if their argument lists
2820 * are equal. Polymorphic method types "have the same arguments",
2821 * if they have the same arguments after renaming all type
2822 * variables of one to corresponding type variables in the other,
2823 * where correspondence is by position in the type parameter list.
2824 */
2825 public boolean hasSameArgs(Type t, Type s) {
2826 return hasSameArgs(t, s, true);
2827 }
2829 public boolean hasSameArgs(Type t, Type s, boolean strict) {
2830 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict);
2831 }
2833 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) {
2834 return hasSameArgs.visit(t, s);
2835 }
2836 // where
2837 private class HasSameArgs extends TypeRelation {
2839 boolean strict;
2841 public HasSameArgs(boolean strict) {
2842 this.strict = strict;
2843 }
2845 public Boolean visitType(Type t, Type s) {
2846 throw new AssertionError();
2847 }
2849 @Override
2850 public Boolean visitMethodType(MethodType t, Type s) {
2851 return s.hasTag(METHOD)
2852 && containsTypeEquivalent(t.argtypes, s.getParameterTypes());
2853 }
2855 @Override
2856 public Boolean visitForAll(ForAll t, Type s) {
2857 if (!s.hasTag(FORALL))
2858 return strict ? false : visitMethodType(t.asMethodType(), s);
2860 ForAll forAll = (ForAll)s;
2861 return hasSameBounds(t, forAll)
2862 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
2863 }
2865 @Override
2866 public Boolean visitErrorType(ErrorType t, Type s) {
2867 return false;
2868 }
2869 };
2871 TypeRelation hasSameArgs_strict = new HasSameArgs(true);
2872 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false);
2874 // </editor-fold>
2876 // <editor-fold defaultstate="collapsed" desc="subst">
2877 public List<Type> subst(List<Type> ts,
2878 List<Type> from,
2879 List<Type> to) {
2880 return new Subst(from, to).subst(ts);
2881 }
2883 /**
2884 * Substitute all occurrences of a type in `from' with the
2885 * corresponding type in `to' in 't'. Match lists `from' and `to'
2886 * from the right: If lists have different length, discard leading
2887 * elements of the longer list.
2888 */
2889 public Type subst(Type t, List<Type> from, List<Type> to) {
2890 return new Subst(from, to).subst(t);
2891 }
2893 private class Subst extends UnaryVisitor<Type> {
2894 List<Type> from;
2895 List<Type> to;
2897 public Subst(List<Type> from, List<Type> to) {
2898 int fromLength = from.length();
2899 int toLength = to.length();
2900 while (fromLength > toLength) {
2901 fromLength--;
2902 from = from.tail;
2903 }
2904 while (fromLength < toLength) {
2905 toLength--;
2906 to = to.tail;
2907 }
2908 this.from = from;
2909 this.to = to;
2910 }
2912 Type subst(Type t) {
2913 if (from.tail == null)
2914 return t;
2915 else
2916 return visit(t);
2917 }
2919 List<Type> subst(List<Type> ts) {
2920 if (from.tail == null)
2921 return ts;
2922 boolean wild = false;
2923 if (ts.nonEmpty() && from.nonEmpty()) {
2924 Type head1 = subst(ts.head);
2925 List<Type> tail1 = subst(ts.tail);
2926 if (head1 != ts.head || tail1 != ts.tail)
2927 return tail1.prepend(head1);
2928 }
2929 return ts;
2930 }
2932 public Type visitType(Type t, Void ignored) {
2933 return t;
2934 }
2936 @Override
2937 public Type visitMethodType(MethodType t, Void ignored) {
2938 List<Type> argtypes = subst(t.argtypes);
2939 Type restype = subst(t.restype);
2940 List<Type> thrown = subst(t.thrown);
2941 if (argtypes == t.argtypes &&
2942 restype == t.restype &&
2943 thrown == t.thrown)
2944 return t;
2945 else
2946 return new MethodType(argtypes, restype, thrown, t.tsym);
2947 }
2949 @Override
2950 public Type visitTypeVar(TypeVar t, Void ignored) {
2951 for (List<Type> from = this.from, to = this.to;
2952 from.nonEmpty();
2953 from = from.tail, to = to.tail) {
2954 if (t == from.head) {
2955 return to.head.withTypeVar(t);
2956 }
2957 }
2958 return t;
2959 }
2961 @Override
2962 public Type visitClassType(ClassType t, Void ignored) {
2963 if (!t.isCompound()) {
2964 List<Type> typarams = t.getTypeArguments();
2965 List<Type> typarams1 = subst(typarams);
2966 Type outer = t.getEnclosingType();
2967 Type outer1 = subst(outer);
2968 if (typarams1 == typarams && outer1 == outer)
2969 return t;
2970 else
2971 return new ClassType(outer1, typarams1, t.tsym);
2972 } else {
2973 Type st = subst(supertype(t));
2974 List<Type> is = upperBounds(subst(interfaces(t)));
2975 if (st == supertype(t) && is == interfaces(t))
2976 return t;
2977 else
2978 return makeCompoundType(is.prepend(st));
2979 }
2980 }
2982 @Override
2983 public Type visitWildcardType(WildcardType t, Void ignored) {
2984 Type bound = t.type;
2985 if (t.kind != BoundKind.UNBOUND)
2986 bound = subst(bound);
2987 if (bound == t.type) {
2988 return t;
2989 } else {
2990 if (t.isExtendsBound() && bound.isExtendsBound())
2991 bound = upperBound(bound);
2992 return new WildcardType(bound, t.kind, syms.boundClass, t.bound);
2993 }
2994 }
2996 @Override
2997 public Type visitArrayType(ArrayType t, Void ignored) {
2998 Type elemtype = subst(t.elemtype);
2999 if (elemtype == t.elemtype)
3000 return t;
3001 else
3002 return new ArrayType(elemtype, t.tsym);
3003 }
3005 @Override
3006 public Type visitForAll(ForAll t, Void ignored) {
3007 if (Type.containsAny(to, t.tvars)) {
3008 //perform alpha-renaming of free-variables in 't'
3009 //if 'to' types contain variables that are free in 't'
3010 List<Type> freevars = newInstances(t.tvars);
3011 t = new ForAll(freevars,
3012 Types.this.subst(t.qtype, t.tvars, freevars));
3013 }
3014 List<Type> tvars1 = substBounds(t.tvars, from, to);
3015 Type qtype1 = subst(t.qtype);
3016 if (tvars1 == t.tvars && qtype1 == t.qtype) {
3017 return t;
3018 } else if (tvars1 == t.tvars) {
3019 return new ForAll(tvars1, qtype1);
3020 } else {
3021 return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1));
3022 }
3023 }
3025 @Override
3026 public Type visitErrorType(ErrorType t, Void ignored) {
3027 return t;
3028 }
3029 }
3031 public List<Type> substBounds(List<Type> tvars,
3032 List<Type> from,
3033 List<Type> to) {
3034 if (tvars.isEmpty())
3035 return tvars;
3036 ListBuffer<Type> newBoundsBuf = new ListBuffer<>();
3037 boolean changed = false;
3038 // calculate new bounds
3039 for (Type t : tvars) {
3040 TypeVar tv = (TypeVar) t;
3041 Type bound = subst(tv.bound, from, to);
3042 if (bound != tv.bound)
3043 changed = true;
3044 newBoundsBuf.append(bound);
3045 }
3046 if (!changed)
3047 return tvars;
3048 ListBuffer<Type> newTvars = new ListBuffer<>();
3049 // create new type variables without bounds
3050 for (Type t : tvars) {
3051 newTvars.append(new TypeVar(t.tsym, null, syms.botType));
3052 }
3053 // the new bounds should use the new type variables in place
3054 // of the old
3055 List<Type> newBounds = newBoundsBuf.toList();
3056 from = tvars;
3057 to = newTvars.toList();
3058 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) {
3059 newBounds.head = subst(newBounds.head, from, to);
3060 }
3061 newBounds = newBoundsBuf.toList();
3062 // set the bounds of new type variables to the new bounds
3063 for (Type t : newTvars.toList()) {
3064 TypeVar tv = (TypeVar) t;
3065 tv.bound = newBounds.head;
3066 newBounds = newBounds.tail;
3067 }
3068 return newTvars.toList();
3069 }
3071 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) {
3072 Type bound1 = subst(t.bound, from, to);
3073 if (bound1 == t.bound)
3074 return t;
3075 else {
3076 // create new type variable without bounds
3077 TypeVar tv = new TypeVar(t.tsym, null, syms.botType);
3078 // the new bound should use the new type variable in place
3079 // of the old
3080 tv.bound = subst(bound1, List.<Type>of(t), List.<Type>of(tv));
3081 return tv;
3082 }
3083 }
3084 // </editor-fold>
3086 // <editor-fold defaultstate="collapsed" desc="hasSameBounds">
3087 /**
3088 * Does t have the same bounds for quantified variables as s?
3089 */
3090 public boolean hasSameBounds(ForAll t, ForAll s) {
3091 List<Type> l1 = t.tvars;
3092 List<Type> l2 = s.tvars;
3093 while (l1.nonEmpty() && l2.nonEmpty() &&
3094 isSameType(l1.head.getUpperBound(),
3095 subst(l2.head.getUpperBound(),
3096 s.tvars,
3097 t.tvars))) {
3098 l1 = l1.tail;
3099 l2 = l2.tail;
3100 }
3101 return l1.isEmpty() && l2.isEmpty();
3102 }
3103 // </editor-fold>
3105 // <editor-fold defaultstate="collapsed" desc="newInstances">
3106 /** Create new vector of type variables from list of variables
3107 * changing all recursive bounds from old to new list.
3108 */
3109 public List<Type> newInstances(List<Type> tvars) {
3110 List<Type> tvars1 = Type.map(tvars, newInstanceFun);
3111 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) {
3112 TypeVar tv = (TypeVar) l.head;
3113 tv.bound = subst(tv.bound, tvars, tvars1);
3114 }
3115 return tvars1;
3116 }
3117 private static final Mapping newInstanceFun = new Mapping("newInstanceFun") {
3118 public Type apply(Type t) { return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound()); }
3119 };
3120 // </editor-fold>
3122 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) {
3123 return original.accept(methodWithParameters, newParams);
3124 }
3125 // where
3126 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() {
3127 public Type visitType(Type t, List<Type> newParams) {
3128 throw new IllegalArgumentException("Not a method type: " + t);
3129 }
3130 public Type visitMethodType(MethodType t, List<Type> newParams) {
3131 return new MethodType(newParams, t.restype, t.thrown, t.tsym);
3132 }
3133 public Type visitForAll(ForAll t, List<Type> newParams) {
3134 return new ForAll(t.tvars, t.qtype.accept(this, newParams));
3135 }
3136 };
3138 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) {
3139 return original.accept(methodWithThrown, newThrown);
3140 }
3141 // where
3142 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() {
3143 public Type visitType(Type t, List<Type> newThrown) {
3144 throw new IllegalArgumentException("Not a method type: " + t);
3145 }
3146 public Type visitMethodType(MethodType t, List<Type> newThrown) {
3147 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym);
3148 }
3149 public Type visitForAll(ForAll t, List<Type> newThrown) {
3150 return new ForAll(t.tvars, t.qtype.accept(this, newThrown));
3151 }
3152 };
3154 public Type createMethodTypeWithReturn(Type original, Type newReturn) {
3155 return original.accept(methodWithReturn, newReturn);
3156 }
3157 // where
3158 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() {
3159 public Type visitType(Type t, Type newReturn) {
3160 throw new IllegalArgumentException("Not a method type: " + t);
3161 }
3162 public Type visitMethodType(MethodType t, Type newReturn) {
3163 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym);
3164 }
3165 public Type visitForAll(ForAll t, Type newReturn) {
3166 return new ForAll(t.tvars, t.qtype.accept(this, newReturn));
3167 }
3168 };
3170 // <editor-fold defaultstate="collapsed" desc="createErrorType">
3171 public Type createErrorType(Type originalType) {
3172 return new ErrorType(originalType, syms.errSymbol);
3173 }
3175 public Type createErrorType(ClassSymbol c, Type originalType) {
3176 return new ErrorType(c, originalType);
3177 }
3179 public Type createErrorType(Name name, TypeSymbol container, Type originalType) {
3180 return new ErrorType(name, container, originalType);
3181 }
3182 // </editor-fold>
3184 // <editor-fold defaultstate="collapsed" desc="rank">
3185 /**
3186 * The rank of a class is the length of the longest path between
3187 * the class and java.lang.Object in the class inheritance
3188 * graph. Undefined for all but reference types.
3189 */
3190 public int rank(Type t) {
3191 t = t.unannotatedType();
3192 switch(t.getTag()) {
3193 case CLASS: {
3194 ClassType cls = (ClassType)t;
3195 if (cls.rank_field < 0) {
3196 Name fullname = cls.tsym.getQualifiedName();
3197 if (fullname == names.java_lang_Object)
3198 cls.rank_field = 0;
3199 else {
3200 int r = rank(supertype(cls));
3201 for (List<Type> l = interfaces(cls);
3202 l.nonEmpty();
3203 l = l.tail) {
3204 if (rank(l.head) > r)
3205 r = rank(l.head);
3206 }
3207 cls.rank_field = r + 1;
3208 }
3209 }
3210 return cls.rank_field;
3211 }
3212 case TYPEVAR: {
3213 TypeVar tvar = (TypeVar)t;
3214 if (tvar.rank_field < 0) {
3215 int r = rank(supertype(tvar));
3216 for (List<Type> l = interfaces(tvar);
3217 l.nonEmpty();
3218 l = l.tail) {
3219 if (rank(l.head) > r) r = rank(l.head);
3220 }
3221 tvar.rank_field = r + 1;
3222 }
3223 return tvar.rank_field;
3224 }
3225 case ERROR:
3226 return 0;
3227 default:
3228 throw new AssertionError();
3229 }
3230 }
3231 // </editor-fold>
3233 /**
3234 * Helper method for generating a string representation of a given type
3235 * accordingly to a given locale
3236 */
3237 public String toString(Type t, Locale locale) {
3238 return Printer.createStandardPrinter(messages).visit(t, locale);
3239 }
3241 /**
3242 * Helper method for generating a string representation of a given type
3243 * accordingly to a given locale
3244 */
3245 public String toString(Symbol t, Locale locale) {
3246 return Printer.createStandardPrinter(messages).visit(t, locale);
3247 }
3249 // <editor-fold defaultstate="collapsed" desc="toString">
3250 /**
3251 * This toString is slightly more descriptive than the one on Type.
3252 *
3253 * @deprecated Types.toString(Type t, Locale l) provides better support
3254 * for localization
3255 */
3256 @Deprecated
3257 public String toString(Type t) {
3258 if (t.hasTag(FORALL)) {
3259 ForAll forAll = (ForAll)t;
3260 return typaramsString(forAll.tvars) + forAll.qtype;
3261 }
3262 return "" + t;
3263 }
3264 // where
3265 private String typaramsString(List<Type> tvars) {
3266 StringBuilder s = new StringBuilder();
3267 s.append('<');
3268 boolean first = true;
3269 for (Type t : tvars) {
3270 if (!first) s.append(", ");
3271 first = false;
3272 appendTyparamString(((TypeVar)t.unannotatedType()), s);
3273 }
3274 s.append('>');
3275 return s.toString();
3276 }
3277 private void appendTyparamString(TypeVar t, StringBuilder buf) {
3278 buf.append(t);
3279 if (t.bound == null ||
3280 t.bound.tsym.getQualifiedName() == names.java_lang_Object)
3281 return;
3282 buf.append(" extends "); // Java syntax; no need for i18n
3283 Type bound = t.bound;
3284 if (!bound.isCompound()) {
3285 buf.append(bound);
3286 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) {
3287 buf.append(supertype(t));
3288 for (Type intf : interfaces(t)) {
3289 buf.append('&');
3290 buf.append(intf);
3291 }
3292 } else {
3293 // No superclass was given in bounds.
3294 // In this case, supertype is Object, erasure is first interface.
3295 boolean first = true;
3296 for (Type intf : interfaces(t)) {
3297 if (!first) buf.append('&');
3298 first = false;
3299 buf.append(intf);
3300 }
3301 }
3302 }
3303 // </editor-fold>
3305 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types">
3306 /**
3307 * A cache for closures.
3308 *
3309 * <p>A closure is a list of all the supertypes and interfaces of
3310 * a class or interface type, ordered by ClassSymbol.precedes
3311 * (that is, subclasses come first, arbitrary but fixed
3312 * otherwise).
3313 */
3314 private Map<Type,List<Type>> closureCache = new HashMap<Type,List<Type>>();
3316 /**
3317 * Returns the closure of a class or interface type.
3318 */
3319 public List<Type> closure(Type t) {
3320 List<Type> cl = closureCache.get(t);
3321 if (cl == null) {
3322 Type st = supertype(t);
3323 if (!t.isCompound()) {
3324 if (st.hasTag(CLASS)) {
3325 cl = insert(closure(st), t);
3326 } else if (st.hasTag(TYPEVAR)) {
3327 cl = closure(st).prepend(t);
3328 } else {
3329 cl = List.of(t);
3330 }
3331 } else {
3332 cl = closure(supertype(t));
3333 }
3334 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail)
3335 cl = union(cl, closure(l.head));
3336 closureCache.put(t, cl);
3337 }
3338 return cl;
3339 }
3341 /**
3342 * Insert a type in a closure
3343 */
3344 public List<Type> insert(List<Type> cl, Type t) {
3345 if (cl.isEmpty()) {
3346 return cl.prepend(t);
3347 } else if (t.tsym == cl.head.tsym) {
3348 return cl;
3349 } else if (t.tsym.precedes(cl.head.tsym, this)) {
3350 return cl.prepend(t);
3351 } else {
3352 // t comes after head, or the two are unrelated
3353 return insert(cl.tail, t).prepend(cl.head);
3354 }
3355 }
3357 /**
3358 * Form the union of two closures
3359 */
3360 public List<Type> union(List<Type> cl1, List<Type> cl2) {
3361 if (cl1.isEmpty()) {
3362 return cl2;
3363 } else if (cl2.isEmpty()) {
3364 return cl1;
3365 } else if (cl1.head.tsym == cl2.head.tsym) {
3366 return union(cl1.tail, cl2.tail).prepend(cl1.head);
3367 } else if (cl1.head.tsym.precedes(cl2.head.tsym, this)) {
3368 return union(cl1.tail, cl2).prepend(cl1.head);
3369 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) {
3370 return union(cl1, cl2.tail).prepend(cl2.head);
3371 } else {
3372 // unrelated types
3373 return union(cl1.tail, cl2).prepend(cl1.head);
3374 }
3375 }
3377 /**
3378 * Intersect two closures
3379 */
3380 public List<Type> intersect(List<Type> cl1, List<Type> cl2) {
3381 if (cl1 == cl2)
3382 return cl1;
3383 if (cl1.isEmpty() || cl2.isEmpty())
3384 return List.nil();
3385 if (cl1.head.tsym.precedes(cl2.head.tsym, this))
3386 return intersect(cl1.tail, cl2);
3387 if (cl2.head.tsym.precedes(cl1.head.tsym, this))
3388 return intersect(cl1, cl2.tail);
3389 if (isSameType(cl1.head, cl2.head))
3390 return intersect(cl1.tail, cl2.tail).prepend(cl1.head);
3391 if (cl1.head.tsym == cl2.head.tsym &&
3392 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) {
3393 if (cl1.head.isParameterized() && cl2.head.isParameterized()) {
3394 Type merge = merge(cl1.head,cl2.head);
3395 return intersect(cl1.tail, cl2.tail).prepend(merge);
3396 }
3397 if (cl1.head.isRaw() || cl2.head.isRaw())
3398 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head));
3399 }
3400 return intersect(cl1.tail, cl2.tail);
3401 }
3402 // where
3403 class TypePair {
3404 final Type t1;
3405 final Type t2;
3406 TypePair(Type t1, Type t2) {
3407 this.t1 = t1;
3408 this.t2 = t2;
3409 }
3410 @Override
3411 public int hashCode() {
3412 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2);
3413 }
3414 @Override
3415 public boolean equals(Object obj) {
3416 if (!(obj instanceof TypePair))
3417 return false;
3418 TypePair typePair = (TypePair)obj;
3419 return isSameType(t1, typePair.t1)
3420 && isSameType(t2, typePair.t2);
3421 }
3422 }
3423 Set<TypePair> mergeCache = new HashSet<TypePair>();
3424 private Type merge(Type c1, Type c2) {
3425 ClassType class1 = (ClassType) c1;
3426 List<Type> act1 = class1.getTypeArguments();
3427 ClassType class2 = (ClassType) c2;
3428 List<Type> act2 = class2.getTypeArguments();
3429 ListBuffer<Type> merged = new ListBuffer<Type>();
3430 List<Type> typarams = class1.tsym.type.getTypeArguments();
3432 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) {
3433 if (containsType(act1.head, act2.head)) {
3434 merged.append(act1.head);
3435 } else if (containsType(act2.head, act1.head)) {
3436 merged.append(act2.head);
3437 } else {
3438 TypePair pair = new TypePair(c1, c2);
3439 Type m;
3440 if (mergeCache.add(pair)) {
3441 m = new WildcardType(lub(upperBound(act1.head),
3442 upperBound(act2.head)),
3443 BoundKind.EXTENDS,
3444 syms.boundClass);
3445 mergeCache.remove(pair);
3446 } else {
3447 m = new WildcardType(syms.objectType,
3448 BoundKind.UNBOUND,
3449 syms.boundClass);
3450 }
3451 merged.append(m.withTypeVar(typarams.head));
3452 }
3453 act1 = act1.tail;
3454 act2 = act2.tail;
3455 typarams = typarams.tail;
3456 }
3457 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty());
3458 return new ClassType(class1.getEnclosingType(), merged.toList(), class1.tsym);
3459 }
3461 /**
3462 * Return the minimum type of a closure, a compound type if no
3463 * unique minimum exists.
3464 */
3465 private Type compoundMin(List<Type> cl) {
3466 if (cl.isEmpty()) return syms.objectType;
3467 List<Type> compound = closureMin(cl);
3468 if (compound.isEmpty())
3469 return null;
3470 else if (compound.tail.isEmpty())
3471 return compound.head;
3472 else
3473 return makeCompoundType(compound);
3474 }
3476 /**
3477 * Return the minimum types of a closure, suitable for computing
3478 * compoundMin or glb.
3479 */
3480 private List<Type> closureMin(List<Type> cl) {
3481 ListBuffer<Type> classes = new ListBuffer<>();
3482 ListBuffer<Type> interfaces = new ListBuffer<>();
3483 Set<Type> toSkip = new HashSet<>();
3484 while (!cl.isEmpty()) {
3485 Type current = cl.head;
3486 boolean keep = !toSkip.contains(current);
3487 if (keep && current.hasTag(TYPEVAR)) {
3488 // skip lower-bounded variables with a subtype in cl.tail
3489 for (Type t : cl.tail) {
3490 if (isSubtypeNoCapture(t, current)) {
3491 keep = false;
3492 break;
3493 }
3494 }
3495 }
3496 if (keep) {
3497 if (current.isInterface())
3498 interfaces.append(current);
3499 else
3500 classes.append(current);
3501 for (Type t : cl.tail) {
3502 // skip supertypes of 'current' in cl.tail
3503 if (isSubtypeNoCapture(current, t))
3504 toSkip.add(t);
3505 }
3506 }
3507 cl = cl.tail;
3508 }
3509 return classes.appendList(interfaces).toList();
3510 }
3512 /**
3513 * Return the least upper bound of pair of types. if the lub does
3514 * not exist return null.
3515 */
3516 public Type lub(Type t1, Type t2) {
3517 return lub(List.of(t1, t2));
3518 }
3520 /**
3521 * Return the least upper bound (lub) of set of types. If the lub
3522 * does not exist return the type of null (bottom).
3523 */
3524 public Type lub(List<Type> ts) {
3525 final int ARRAY_BOUND = 1;
3526 final int CLASS_BOUND = 2;
3527 int boundkind = 0;
3528 for (Type t : ts) {
3529 switch (t.getTag()) {
3530 case CLASS:
3531 boundkind |= CLASS_BOUND;
3532 break;
3533 case ARRAY:
3534 boundkind |= ARRAY_BOUND;
3535 break;
3536 case TYPEVAR:
3537 do {
3538 t = t.getUpperBound();
3539 } while (t.hasTag(TYPEVAR));
3540 if (t.hasTag(ARRAY)) {
3541 boundkind |= ARRAY_BOUND;
3542 } else {
3543 boundkind |= CLASS_BOUND;
3544 }
3545 break;
3546 default:
3547 if (t.isPrimitive())
3548 return syms.errType;
3549 }
3550 }
3551 switch (boundkind) {
3552 case 0:
3553 return syms.botType;
3555 case ARRAY_BOUND:
3556 // calculate lub(A[], B[])
3557 List<Type> elements = Type.map(ts, elemTypeFun);
3558 for (Type t : elements) {
3559 if (t.isPrimitive()) {
3560 // if a primitive type is found, then return
3561 // arraySuperType unless all the types are the
3562 // same
3563 Type first = ts.head;
3564 for (Type s : ts.tail) {
3565 if (!isSameType(first, s)) {
3566 // lub(int[], B[]) is Cloneable & Serializable
3567 return arraySuperType();
3568 }
3569 }
3570 // all the array types are the same, return one
3571 // lub(int[], int[]) is int[]
3572 return first;
3573 }
3574 }
3575 // lub(A[], B[]) is lub(A, B)[]
3576 return new ArrayType(lub(elements), syms.arrayClass);
3578 case CLASS_BOUND:
3579 // calculate lub(A, B)
3580 while (!ts.head.hasTag(CLASS) && !ts.head.hasTag(TYPEVAR)) {
3581 ts = ts.tail;
3582 }
3583 Assert.check(!ts.isEmpty());
3584 //step 1 - compute erased candidate set (EC)
3585 List<Type> cl = erasedSupertypes(ts.head);
3586 for (Type t : ts.tail) {
3587 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR))
3588 cl = intersect(cl, erasedSupertypes(t));
3589 }
3590 //step 2 - compute minimal erased candidate set (MEC)
3591 List<Type> mec = closureMin(cl);
3592 //step 3 - for each element G in MEC, compute lci(Inv(G))
3593 List<Type> candidates = List.nil();
3594 for (Type erasedSupertype : mec) {
3595 List<Type> lci = List.of(asSuper(ts.head, erasedSupertype.tsym));
3596 for (Type t : ts) {
3597 lci = intersect(lci, List.of(asSuper(t, erasedSupertype.tsym)));
3598 }
3599 candidates = candidates.appendList(lci);
3600 }
3601 //step 4 - let MEC be { G1, G2 ... Gn }, then we have that
3602 //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn))
3603 return compoundMin(candidates);
3605 default:
3606 // calculate lub(A, B[])
3607 List<Type> classes = List.of(arraySuperType());
3608 for (Type t : ts) {
3609 if (!t.hasTag(ARRAY)) // Filter out any arrays
3610 classes = classes.prepend(t);
3611 }
3612 // lub(A, B[]) is lub(A, arraySuperType)
3613 return lub(classes);
3614 }
3615 }
3616 // where
3617 List<Type> erasedSupertypes(Type t) {
3618 ListBuffer<Type> buf = new ListBuffer<>();
3619 for (Type sup : closure(t)) {
3620 if (sup.hasTag(TYPEVAR)) {
3621 buf.append(sup);
3622 } else {
3623 buf.append(erasure(sup));
3624 }
3625 }
3626 return buf.toList();
3627 }
3629 private Type arraySuperType = null;
3630 private Type arraySuperType() {
3631 // initialized lazily to avoid problems during compiler startup
3632 if (arraySuperType == null) {
3633 synchronized (this) {
3634 if (arraySuperType == null) {
3635 // JLS 10.8: all arrays implement Cloneable and Serializable.
3636 arraySuperType = makeCompoundType(List.of(syms.serializableType,
3637 syms.cloneableType), true);
3638 }
3639 }
3640 }
3641 return arraySuperType;
3642 }
3643 // </editor-fold>
3645 // <editor-fold defaultstate="collapsed" desc="Greatest lower bound">
3646 public Type glb(List<Type> ts) {
3647 Type t1 = ts.head;
3648 for (Type t2 : ts.tail) {
3649 if (t1.isErroneous())
3650 return t1;
3651 t1 = glb(t1, t2);
3652 }
3653 return t1;
3654 }
3655 //where
3656 public Type glb(Type t, Type s) {
3657 if (s == null)
3658 return t;
3659 else if (t.isPrimitive() || s.isPrimitive())
3660 return syms.errType;
3661 else if (isSubtypeNoCapture(t, s))
3662 return t;
3663 else if (isSubtypeNoCapture(s, t))
3664 return s;
3666 List<Type> closure = union(closure(t), closure(s));
3667 return glbFlattened(closure, t);
3668 }
3669 //where
3670 /**
3671 * Perform glb for a list of non-primitive, non-error, non-compound types;
3672 * redundant elements are removed. Bounds should be ordered according to
3673 * {@link Symbol#precedes(TypeSymbol,Types)}.
3674 *
3675 * @param flatBounds List of type to glb
3676 * @param errT Original type to use if the result is an error type
3677 */
3678 private Type glbFlattened(List<Type> flatBounds, Type errT) {
3679 List<Type> bounds = closureMin(flatBounds);
3681 if (bounds.isEmpty()) { // length == 0
3682 return syms.objectType;
3683 } else if (bounds.tail.isEmpty()) { // length == 1
3684 return bounds.head;
3685 } else { // length > 1
3686 int classCount = 0;
3687 List<Type> lowers = List.nil();
3688 for (Type bound : bounds) {
3689 if (!bound.isInterface()) {
3690 classCount++;
3691 Type lower = cvarLowerBound(bound);
3692 if (bound != lower && !lower.hasTag(BOT))
3693 lowers = insert(lowers, lower);
3694 }
3695 }
3696 if (classCount > 1) {
3697 if (lowers.isEmpty())
3698 return createErrorType(errT);
3699 else
3700 return glbFlattened(union(bounds, lowers), errT);
3701 }
3702 }
3703 return makeCompoundType(bounds);
3704 }
3705 // </editor-fold>
3707 // <editor-fold defaultstate="collapsed" desc="hashCode">
3708 /**
3709 * Compute a hash code on a type.
3710 */
3711 public int hashCode(Type t) {
3712 return hashCode.visit(t);
3713 }
3714 // where
3715 private static final UnaryVisitor<Integer> hashCode = new UnaryVisitor<Integer>() {
3717 public Integer visitType(Type t, Void ignored) {
3718 return t.getTag().ordinal();
3719 }
3721 @Override
3722 public Integer visitClassType(ClassType t, Void ignored) {
3723 int result = visit(t.getEnclosingType());
3724 result *= 127;
3725 result += t.tsym.flatName().hashCode();
3726 for (Type s : t.getTypeArguments()) {
3727 result *= 127;
3728 result += visit(s);
3729 }
3730 return result;
3731 }
3733 @Override
3734 public Integer visitMethodType(MethodType t, Void ignored) {
3735 int h = METHOD.ordinal();
3736 for (List<Type> thisargs = t.argtypes;
3737 thisargs.tail != null;
3738 thisargs = thisargs.tail)
3739 h = (h << 5) + visit(thisargs.head);
3740 return (h << 5) + visit(t.restype);
3741 }
3743 @Override
3744 public Integer visitWildcardType(WildcardType t, Void ignored) {
3745 int result = t.kind.hashCode();
3746 if (t.type != null) {
3747 result *= 127;
3748 result += visit(t.type);
3749 }
3750 return result;
3751 }
3753 @Override
3754 public Integer visitArrayType(ArrayType t, Void ignored) {
3755 return visit(t.elemtype) + 12;
3756 }
3758 @Override
3759 public Integer visitTypeVar(TypeVar t, Void ignored) {
3760 return System.identityHashCode(t.tsym);
3761 }
3763 @Override
3764 public Integer visitUndetVar(UndetVar t, Void ignored) {
3765 return System.identityHashCode(t);
3766 }
3768 @Override
3769 public Integer visitErrorType(ErrorType t, Void ignored) {
3770 return 0;
3771 }
3772 };
3773 // </editor-fold>
3775 // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable">
3776 /**
3777 * Does t have a result that is a subtype of the result type of s,
3778 * suitable for covariant returns? It is assumed that both types
3779 * are (possibly polymorphic) method types. Monomorphic method
3780 * types are handled in the obvious way. Polymorphic method types
3781 * require renaming all type variables of one to corresponding
3782 * type variables in the other, where correspondence is by
3783 * position in the type parameter list. */
3784 public boolean resultSubtype(Type t, Type s, Warner warner) {
3785 List<Type> tvars = t.getTypeArguments();
3786 List<Type> svars = s.getTypeArguments();
3787 Type tres = t.getReturnType();
3788 Type sres = subst(s.getReturnType(), svars, tvars);
3789 return covariantReturnType(tres, sres, warner);
3790 }
3792 /**
3793 * Return-Type-Substitutable.
3794 * @jls section 8.4.5
3795 */
3796 public boolean returnTypeSubstitutable(Type r1, Type r2) {
3797 if (hasSameArgs(r1, r2))
3798 return resultSubtype(r1, r2, noWarnings);
3799 else
3800 return covariantReturnType(r1.getReturnType(),
3801 erasure(r2.getReturnType()),
3802 noWarnings);
3803 }
3805 public boolean returnTypeSubstitutable(Type r1,
3806 Type r2, Type r2res,
3807 Warner warner) {
3808 if (isSameType(r1.getReturnType(), r2res))
3809 return true;
3810 if (r1.getReturnType().isPrimitive() || r2res.isPrimitive())
3811 return false;
3813 if (hasSameArgs(r1, r2))
3814 return covariantReturnType(r1.getReturnType(), r2res, warner);
3815 if (!allowCovariantReturns)
3816 return false;
3817 if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner))
3818 return true;
3819 if (!isSubtype(r1.getReturnType(), erasure(r2res)))
3820 return false;
3821 warner.warn(LintCategory.UNCHECKED);
3822 return true;
3823 }
3825 /**
3826 * Is t an appropriate return type in an overrider for a
3827 * method that returns s?
3828 */
3829 public boolean covariantReturnType(Type t, Type s, Warner warner) {
3830 return
3831 isSameType(t, s) ||
3832 allowCovariantReturns &&
3833 !t.isPrimitive() &&
3834 !s.isPrimitive() &&
3835 isAssignable(t, s, warner);
3836 }
3837 // </editor-fold>
3839 // <editor-fold defaultstate="collapsed" desc="Box/unbox support">
3840 /**
3841 * Return the class that boxes the given primitive.
3842 */
3843 public ClassSymbol boxedClass(Type t) {
3844 return reader.enterClass(syms.boxedName[t.getTag().ordinal()]);
3845 }
3847 /**
3848 * Return the boxed type if 't' is primitive, otherwise return 't' itself.
3849 */
3850 public Type boxedTypeOrType(Type t) {
3851 return t.isPrimitive() ?
3852 boxedClass(t).type :
3853 t;
3854 }
3856 /**
3857 * Return the primitive type corresponding to a boxed type.
3858 */
3859 public Type unboxedType(Type t) {
3860 if (allowBoxing) {
3861 for (int i=0; i<syms.boxedName.length; i++) {
3862 Name box = syms.boxedName[i];
3863 if (box != null &&
3864 asSuper(t, reader.enterClass(box)) != null)
3865 return syms.typeOfTag[i];
3866 }
3867 }
3868 return Type.noType;
3869 }
3871 /**
3872 * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself.
3873 */
3874 public Type unboxedTypeOrType(Type t) {
3875 Type unboxedType = unboxedType(t);
3876 return unboxedType.hasTag(NONE) ? t : unboxedType;
3877 }
3878 // </editor-fold>
3880 // <editor-fold defaultstate="collapsed" desc="Capture conversion">
3881 /*
3882 * JLS 5.1.10 Capture Conversion:
3883 *
3884 * Let G name a generic type declaration with n formal type
3885 * parameters A1 ... An with corresponding bounds U1 ... Un. There
3886 * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>,
3887 * where, for 1 <= i <= n:
3888 *
3889 * + If Ti is a wildcard type argument (4.5.1) of the form ? then
3890 * Si is a fresh type variable whose upper bound is
3891 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null
3892 * type.
3893 *
3894 * + If Ti is a wildcard type argument of the form ? extends Bi,
3895 * then Si is a fresh type variable whose upper bound is
3896 * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is
3897 * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is
3898 * a compile-time error if for any two classes (not interfaces)
3899 * Vi and Vj,Vi is not a subclass of Vj or vice versa.
3900 *
3901 * + If Ti is a wildcard type argument of the form ? super Bi,
3902 * then Si is a fresh type variable whose upper bound is
3903 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi.
3904 *
3905 * + Otherwise, Si = Ti.
3906 *
3907 * Capture conversion on any type other than a parameterized type
3908 * (4.5) acts as an identity conversion (5.1.1). Capture
3909 * conversions never require a special action at run time and
3910 * therefore never throw an exception at run time.
3911 *
3912 * Capture conversion is not applied recursively.
3913 */
3914 /**
3915 * Capture conversion as specified by the JLS.
3916 */
3918 public List<Type> capture(List<Type> ts) {
3919 List<Type> buf = List.nil();
3920 for (Type t : ts) {
3921 buf = buf.prepend(capture(t));
3922 }
3923 return buf.reverse();
3924 }
3926 public Type capture(Type t) {
3927 if (!t.hasTag(CLASS)) {
3928 return t;
3929 }
3930 if (t.getEnclosingType() != Type.noType) {
3931 Type capturedEncl = capture(t.getEnclosingType());
3932 if (capturedEncl != t.getEnclosingType()) {
3933 Type type1 = memberType(capturedEncl, t.tsym);
3934 t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments());
3935 }
3936 }
3937 t = t.unannotatedType();
3938 ClassType cls = (ClassType)t;
3939 if (cls.isRaw() || !cls.isParameterized())
3940 return cls;
3942 ClassType G = (ClassType)cls.asElement().asType();
3943 List<Type> A = G.getTypeArguments();
3944 List<Type> T = cls.getTypeArguments();
3945 List<Type> S = freshTypeVariables(T);
3947 List<Type> currentA = A;
3948 List<Type> currentT = T;
3949 List<Type> currentS = S;
3950 boolean captured = false;
3951 while (!currentA.isEmpty() &&
3952 !currentT.isEmpty() &&
3953 !currentS.isEmpty()) {
3954 if (currentS.head != currentT.head) {
3955 captured = true;
3956 WildcardType Ti = (WildcardType)currentT.head.unannotatedType();
3957 Type Ui = currentA.head.getUpperBound();
3958 CapturedType Si = (CapturedType)currentS.head.unannotatedType();
3959 if (Ui == null)
3960 Ui = syms.objectType;
3961 switch (Ti.kind) {
3962 case UNBOUND:
3963 Si.bound = subst(Ui, A, S);
3964 Si.lower = syms.botType;
3965 break;
3966 case EXTENDS:
3967 Si.bound = glb(Ti.getExtendsBound(), subst(Ui, A, S));
3968 Si.lower = syms.botType;
3969 break;
3970 case SUPER:
3971 Si.bound = subst(Ui, A, S);
3972 Si.lower = Ti.getSuperBound();
3973 break;
3974 }
3975 Type tmpBound = Si.bound.hasTag(UNDETVAR) ? ((UndetVar)Si.bound).qtype : Si.bound;
3976 Type tmpLower = Si.lower.hasTag(UNDETVAR) ? ((UndetVar)Si.lower).qtype : Si.lower;
3977 if (!Si.bound.hasTag(ERROR) &&
3978 !Si.lower.hasTag(ERROR) &&
3979 isSameType(tmpBound, tmpLower, false)) {
3980 currentS.head = Si.bound;
3981 }
3982 }
3983 currentA = currentA.tail;
3984 currentT = currentT.tail;
3985 currentS = currentS.tail;
3986 }
3987 if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty())
3988 return erasure(t); // some "rare" type involved
3990 if (captured)
3991 return new ClassType(cls.getEnclosingType(), S, cls.tsym);
3992 else
3993 return t;
3994 }
3995 // where
3996 public List<Type> freshTypeVariables(List<Type> types) {
3997 ListBuffer<Type> result = new ListBuffer<>();
3998 for (Type t : types) {
3999 if (t.hasTag(WILDCARD)) {
4000 t = t.unannotatedType();
4001 Type bound = ((WildcardType)t).getExtendsBound();
4002 if (bound == null)
4003 bound = syms.objectType;
4004 result.append(new CapturedType(capturedName,
4005 syms.noSymbol,
4006 bound,
4007 syms.botType,
4008 (WildcardType)t));
4009 } else {
4010 result.append(t);
4011 }
4012 }
4013 return result.toList();
4014 }
4015 // </editor-fold>
4017 // <editor-fold defaultstate="collapsed" desc="Internal utility methods">
4018 private List<Type> upperBounds(List<Type> ss) {
4019 if (ss.isEmpty()) return ss;
4020 Type head = upperBound(ss.head);
4021 List<Type> tail = upperBounds(ss.tail);
4022 if (head != ss.head || tail != ss.tail)
4023 return tail.prepend(head);
4024 else
4025 return ss;
4026 }
4028 private boolean sideCast(Type from, Type to, Warner warn) {
4029 // We are casting from type $from$ to type $to$, which are
4030 // non-final unrelated types. This method
4031 // tries to reject a cast by transferring type parameters
4032 // from $to$ to $from$ by common superinterfaces.
4033 boolean reverse = false;
4034 Type target = to;
4035 if ((to.tsym.flags() & INTERFACE) == 0) {
4036 Assert.check((from.tsym.flags() & INTERFACE) != 0);
4037 reverse = true;
4038 to = from;
4039 from = target;
4040 }
4041 List<Type> commonSupers = superClosure(to, erasure(from));
4042 boolean giveWarning = commonSupers.isEmpty();
4043 // The arguments to the supers could be unified here to
4044 // get a more accurate analysis
4045 while (commonSupers.nonEmpty()) {
4046 Type t1 = asSuper(from, commonSupers.head.tsym);
4047 Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym);
4048 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4049 return false;
4050 giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2));
4051 commonSupers = commonSupers.tail;
4052 }
4053 if (giveWarning && !isReifiable(reverse ? from : to))
4054 warn.warn(LintCategory.UNCHECKED);
4055 if (!allowCovariantReturns)
4056 // reject if there is a common method signature with
4057 // incompatible return types.
4058 chk.checkCompatibleAbstracts(warn.pos(), from, to);
4059 return true;
4060 }
4062 private boolean sideCastFinal(Type from, Type to, Warner warn) {
4063 // We are casting from type $from$ to type $to$, which are
4064 // unrelated types one of which is final and the other of
4065 // which is an interface. This method
4066 // tries to reject a cast by transferring type parameters
4067 // from the final class to the interface.
4068 boolean reverse = false;
4069 Type target = to;
4070 if ((to.tsym.flags() & INTERFACE) == 0) {
4071 Assert.check((from.tsym.flags() & INTERFACE) != 0);
4072 reverse = true;
4073 to = from;
4074 from = target;
4075 }
4076 Assert.check((from.tsym.flags() & FINAL) != 0);
4077 Type t1 = asSuper(from, to.tsym);
4078 if (t1 == null) return false;
4079 Type t2 = to;
4080 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4081 return false;
4082 if (!allowCovariantReturns)
4083 // reject if there is a common method signature with
4084 // incompatible return types.
4085 chk.checkCompatibleAbstracts(warn.pos(), from, to);
4086 if (!isReifiable(target) &&
4087 (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)))
4088 warn.warn(LintCategory.UNCHECKED);
4089 return true;
4090 }
4092 private boolean giveWarning(Type from, Type to) {
4093 List<Type> bounds = to.isCompound() ?
4094 ((IntersectionClassType)to.unannotatedType()).getComponents() : List.of(to);
4095 for (Type b : bounds) {
4096 Type subFrom = asSub(from, b.tsym);
4097 if (b.isParameterized() &&
4098 (!(isUnbounded(b) ||
4099 isSubtype(from, b) ||
4100 ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) {
4101 return true;
4102 }
4103 }
4104 return false;
4105 }
4107 private List<Type> superClosure(Type t, Type s) {
4108 List<Type> cl = List.nil();
4109 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
4110 if (isSubtype(s, erasure(l.head))) {
4111 cl = insert(cl, l.head);
4112 } else {
4113 cl = union(cl, superClosure(l.head, s));
4114 }
4115 }
4116 return cl;
4117 }
4119 private boolean containsTypeEquivalent(Type t, Type s) {
4120 return
4121 isSameType(t, s) || // shortcut
4122 containsType(t, s) && containsType(s, t);
4123 }
4125 // <editor-fold defaultstate="collapsed" desc="adapt">
4126 /**
4127 * Adapt a type by computing a substitution which maps a source
4128 * type to a target type.
4129 *
4130 * @param source the source type
4131 * @param target the target type
4132 * @param from the type variables of the computed substitution
4133 * @param to the types of the computed substitution.
4134 */
4135 public void adapt(Type source,
4136 Type target,
4137 ListBuffer<Type> from,
4138 ListBuffer<Type> to) throws AdaptFailure {
4139 new Adapter(from, to).adapt(source, target);
4140 }
4142 class Adapter extends SimpleVisitor<Void, Type> {
4144 ListBuffer<Type> from;
4145 ListBuffer<Type> to;
4146 Map<Symbol,Type> mapping;
4148 Adapter(ListBuffer<Type> from, ListBuffer<Type> to) {
4149 this.from = from;
4150 this.to = to;
4151 mapping = new HashMap<Symbol,Type>();
4152 }
4154 public void adapt(Type source, Type target) throws AdaptFailure {
4155 visit(source, target);
4156 List<Type> fromList = from.toList();
4157 List<Type> toList = to.toList();
4158 while (!fromList.isEmpty()) {
4159 Type val = mapping.get(fromList.head.tsym);
4160 if (toList.head != val)
4161 toList.head = val;
4162 fromList = fromList.tail;
4163 toList = toList.tail;
4164 }
4165 }
4167 @Override
4168 public Void visitClassType(ClassType source, Type target) throws AdaptFailure {
4169 if (target.hasTag(CLASS))
4170 adaptRecursive(source.allparams(), target.allparams());
4171 return null;
4172 }
4174 @Override
4175 public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure {
4176 if (target.hasTag(ARRAY))
4177 adaptRecursive(elemtype(source), elemtype(target));
4178 return null;
4179 }
4181 @Override
4182 public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure {
4183 if (source.isExtendsBound())
4184 adaptRecursive(upperBound(source), upperBound(target));
4185 else if (source.isSuperBound())
4186 adaptRecursive(wildLowerBound(source), wildLowerBound(target));
4187 return null;
4188 }
4190 @Override
4191 public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure {
4192 // Check to see if there is
4193 // already a mapping for $source$, in which case
4194 // the old mapping will be merged with the new
4195 Type val = mapping.get(source.tsym);
4196 if (val != null) {
4197 if (val.isSuperBound() && target.isSuperBound()) {
4198 val = isSubtype(wildLowerBound(val), wildLowerBound(target))
4199 ? target : val;
4200 } else if (val.isExtendsBound() && target.isExtendsBound()) {
4201 val = isSubtype(upperBound(val), upperBound(target))
4202 ? val : target;
4203 } else if (!isSameType(val, target)) {
4204 throw new AdaptFailure();
4205 }
4206 } else {
4207 val = target;
4208 from.append(source);
4209 to.append(target);
4210 }
4211 mapping.put(source.tsym, val);
4212 return null;
4213 }
4215 @Override
4216 public Void visitType(Type source, Type target) {
4217 return null;
4218 }
4220 private Set<TypePair> cache = new HashSet<TypePair>();
4222 private void adaptRecursive(Type source, Type target) {
4223 TypePair pair = new TypePair(source, target);
4224 if (cache.add(pair)) {
4225 try {
4226 visit(source, target);
4227 } finally {
4228 cache.remove(pair);
4229 }
4230 }
4231 }
4233 private void adaptRecursive(List<Type> source, List<Type> target) {
4234 if (source.length() == target.length()) {
4235 while (source.nonEmpty()) {
4236 adaptRecursive(source.head, target.head);
4237 source = source.tail;
4238 target = target.tail;
4239 }
4240 }
4241 }
4242 }
4244 public static class AdaptFailure extends RuntimeException {
4245 static final long serialVersionUID = -7490231548272701566L;
4246 }
4248 private void adaptSelf(Type t,
4249 ListBuffer<Type> from,
4250 ListBuffer<Type> to) {
4251 try {
4252 //if (t.tsym.type != t)
4253 adapt(t.tsym.type, t, from, to);
4254 } catch (AdaptFailure ex) {
4255 // Adapt should never fail calculating a mapping from
4256 // t.tsym.type to t as there can be no merge problem.
4257 throw new AssertionError(ex);
4258 }
4259 }
4260 // </editor-fold>
4262 /**
4263 * Rewrite all type variables (universal quantifiers) in the given
4264 * type to wildcards (existential quantifiers). This is used to
4265 * determine if a cast is allowed. For example, if high is true
4266 * and {@code T <: Number}, then {@code List<T>} is rewritten to
4267 * {@code List<? extends Number>}. Since {@code List<Integer> <:
4268 * List<? extends Number>} a {@code List<T>} can be cast to {@code
4269 * List<Integer>} with a warning.
4270 * @param t a type
4271 * @param high if true return an upper bound; otherwise a lower
4272 * bound
4273 * @param rewriteTypeVars only rewrite captured wildcards if false;
4274 * otherwise rewrite all type variables
4275 * @return the type rewritten with wildcards (existential
4276 * quantifiers) only
4277 */
4278 private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) {
4279 return new Rewriter(high, rewriteTypeVars).visit(t);
4280 }
4282 class Rewriter extends UnaryVisitor<Type> {
4284 boolean high;
4285 boolean rewriteTypeVars;
4287 Rewriter(boolean high, boolean rewriteTypeVars) {
4288 this.high = high;
4289 this.rewriteTypeVars = rewriteTypeVars;
4290 }
4292 @Override
4293 public Type visitClassType(ClassType t, Void s) {
4294 ListBuffer<Type> rewritten = new ListBuffer<Type>();
4295 boolean changed = false;
4296 for (Type arg : t.allparams()) {
4297 Type bound = visit(arg);
4298 if (arg != bound) {
4299 changed = true;
4300 }
4301 rewritten.append(bound);
4302 }
4303 if (changed)
4304 return subst(t.tsym.type,
4305 t.tsym.type.allparams(),
4306 rewritten.toList());
4307 else
4308 return t;
4309 }
4311 public Type visitType(Type t, Void s) {
4312 return high ? upperBound(t) : t;
4313 }
4315 @Override
4316 public Type visitCapturedType(CapturedType t, Void s) {
4317 Type w_bound = t.wildcard.type;
4318 Type bound = w_bound.contains(t) ?
4319 erasure(w_bound) :
4320 visit(w_bound);
4321 return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind);
4322 }
4324 @Override
4325 public Type visitTypeVar(TypeVar t, Void s) {
4326 if (rewriteTypeVars) {
4327 Type bound = t.bound.contains(t) ?
4328 erasure(t.bound) :
4329 visit(t.bound);
4330 return rewriteAsWildcardType(bound, t, EXTENDS);
4331 } else {
4332 return t;
4333 }
4334 }
4336 @Override
4337 public Type visitWildcardType(WildcardType t, Void s) {
4338 Type bound2 = visit(t.type);
4339 return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind);
4340 }
4342 private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) {
4343 switch (bk) {
4344 case EXTENDS: return high ?
4345 makeExtendsWildcard(B(bound), formal) :
4346 makeExtendsWildcard(syms.objectType, formal);
4347 case SUPER: return high ?
4348 makeSuperWildcard(syms.botType, formal) :
4349 makeSuperWildcard(B(bound), formal);
4350 case UNBOUND: return makeExtendsWildcard(syms.objectType, formal);
4351 default:
4352 Assert.error("Invalid bound kind " + bk);
4353 return null;
4354 }
4355 }
4357 Type B(Type t) {
4358 while (t.hasTag(WILDCARD)) {
4359 WildcardType w = (WildcardType)t.unannotatedType();
4360 t = high ?
4361 w.getExtendsBound() :
4362 w.getSuperBound();
4363 if (t == null) {
4364 t = high ? syms.objectType : syms.botType;
4365 }
4366 }
4367 return t;
4368 }
4369 }
4372 /**
4373 * Create a wildcard with the given upper (extends) bound; create
4374 * an unbounded wildcard if bound is Object.
4375 *
4376 * @param bound the upper bound
4377 * @param formal the formal type parameter that will be
4378 * substituted by the wildcard
4379 */
4380 private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) {
4381 if (bound == syms.objectType) {
4382 return new WildcardType(syms.objectType,
4383 BoundKind.UNBOUND,
4384 syms.boundClass,
4385 formal);
4386 } else {
4387 return new WildcardType(bound,
4388 BoundKind.EXTENDS,
4389 syms.boundClass,
4390 formal);
4391 }
4392 }
4394 /**
4395 * Create a wildcard with the given lower (super) bound; create an
4396 * unbounded wildcard if bound is bottom (type of {@code null}).
4397 *
4398 * @param bound the lower bound
4399 * @param formal the formal type parameter that will be
4400 * substituted by the wildcard
4401 */
4402 private WildcardType makeSuperWildcard(Type bound, TypeVar formal) {
4403 if (bound.hasTag(BOT)) {
4404 return new WildcardType(syms.objectType,
4405 BoundKind.UNBOUND,
4406 syms.boundClass,
4407 formal);
4408 } else {
4409 return new WildcardType(bound,
4410 BoundKind.SUPER,
4411 syms.boundClass,
4412 formal);
4413 }
4414 }
4416 /**
4417 * A wrapper for a type that allows use in sets.
4418 */
4419 public static class UniqueType {
4420 public final Type type;
4421 final Types types;
4423 public UniqueType(Type type, Types types) {
4424 this.type = type;
4425 this.types = types;
4426 }
4428 public int hashCode() {
4429 return types.hashCode(type);
4430 }
4432 public boolean equals(Object obj) {
4433 return (obj instanceof UniqueType) &&
4434 types.isSameAnnotatedType(type, ((UniqueType)obj).type);
4435 }
4437 public String toString() {
4438 return type.toString();
4439 }
4441 }
4442 // </editor-fold>
4444 // <editor-fold defaultstate="collapsed" desc="Visitors">
4445 /**
4446 * A default visitor for types. All visitor methods except
4447 * visitType are implemented by delegating to visitType. Concrete
4448 * subclasses must provide an implementation of visitType and can
4449 * override other methods as needed.
4450 *
4451 * @param <R> the return type of the operation implemented by this
4452 * visitor; use Void if no return type is needed.
4453 * @param <S> the type of the second argument (the first being the
4454 * type itself) of the operation implemented by this visitor; use
4455 * Void if a second argument is not needed.
4456 */
4457 public static abstract class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> {
4458 final public R visit(Type t, S s) { return t.accept(this, s); }
4459 public R visitClassType(ClassType t, S s) { return visitType(t, s); }
4460 public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); }
4461 public R visitArrayType(ArrayType t, S s) { return visitType(t, s); }
4462 public R visitMethodType(MethodType t, S s) { return visitType(t, s); }
4463 public R visitPackageType(PackageType t, S s) { return visitType(t, s); }
4464 public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); }
4465 public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); }
4466 public R visitForAll(ForAll t, S s) { return visitType(t, s); }
4467 public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); }
4468 public R visitErrorType(ErrorType t, S s) { return visitType(t, s); }
4469 // Pretend annotations don't exist
4470 public R visitAnnotatedType(AnnotatedType t, S s) { return visit(t.unannotatedType(), s); }
4471 }
4473 /**
4474 * A default visitor for symbols. All visitor methods except
4475 * visitSymbol are implemented by delegating to visitSymbol. Concrete
4476 * subclasses must provide an implementation of visitSymbol and can
4477 * override other methods as needed.
4478 *
4479 * @param <R> the return type of the operation implemented by this
4480 * visitor; use Void if no return type is needed.
4481 * @param <S> the type of the second argument (the first being the
4482 * symbol itself) of the operation implemented by this visitor; use
4483 * Void if a second argument is not needed.
4484 */
4485 public static abstract class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> {
4486 final public R visit(Symbol s, S arg) { return s.accept(this, arg); }
4487 public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); }
4488 public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); }
4489 public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); }
4490 public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); }
4491 public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); }
4492 public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); }
4493 }
4495 /**
4496 * A <em>simple</em> visitor for types. This visitor is simple as
4497 * captured wildcards, for-all types (generic methods), and
4498 * undetermined type variables (part of inference) are hidden.
4499 * Captured wildcards are hidden by treating them as type
4500 * variables and the rest are hidden by visiting their qtypes.
4501 *
4502 * @param <R> the return type of the operation implemented by this
4503 * visitor; use Void if no return type is needed.
4504 * @param <S> the type of the second argument (the first being the
4505 * type itself) of the operation implemented by this visitor; use
4506 * Void if a second argument is not needed.
4507 */
4508 public static abstract class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> {
4509 @Override
4510 public R visitCapturedType(CapturedType t, S s) {
4511 return visitTypeVar(t, s);
4512 }
4513 @Override
4514 public R visitForAll(ForAll t, S s) {
4515 return visit(t.qtype, s);
4516 }
4517 @Override
4518 public R visitUndetVar(UndetVar t, S s) {
4519 return visit(t.qtype, s);
4520 }
4521 }
4523 /**
4524 * A plain relation on types. That is a 2-ary function on the
4525 * form Type × Type → Boolean.
4526 * <!-- In plain text: Type x Type -> Boolean -->
4527 */
4528 public static abstract class TypeRelation extends SimpleVisitor<Boolean,Type> {}
4530 /**
4531 * A convenience visitor for implementing operations that only
4532 * require one argument (the type itself), that is, unary
4533 * operations.
4534 *
4535 * @param <R> the return type of the operation implemented by this
4536 * visitor; use Void if no return type is needed.
4537 */
4538 public static abstract class UnaryVisitor<R> extends SimpleVisitor<R,Void> {
4539 final public R visit(Type t) { return t.accept(this, null); }
4540 }
4542 /**
4543 * A visitor for implementing a mapping from types to types. The
4544 * default behavior of this class is to implement the identity
4545 * mapping (mapping a type to itself). This can be overridden in
4546 * subclasses.
4547 *
4548 * @param <S> the type of the second argument (the first being the
4549 * type itself) of this mapping; use Void if a second argument is
4550 * not needed.
4551 */
4552 public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> {
4553 final public Type visit(Type t) { return t.accept(this, null); }
4554 public Type visitType(Type t, S s) { return t; }
4555 }
4556 // </editor-fold>
4559 // <editor-fold defaultstate="collapsed" desc="Annotation support">
4561 public RetentionPolicy getRetention(Attribute.Compound a) {
4562 return getRetention(a.type.tsym);
4563 }
4565 public RetentionPolicy getRetention(Symbol sym) {
4566 RetentionPolicy vis = RetentionPolicy.CLASS; // the default
4567 Attribute.Compound c = sym.attribute(syms.retentionType.tsym);
4568 if (c != null) {
4569 Attribute value = c.member(names.value);
4570 if (value != null && value instanceof Attribute.Enum) {
4571 Name levelName = ((Attribute.Enum)value).value.name;
4572 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE;
4573 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS;
4574 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME;
4575 else ;// /* fail soft */ throw new AssertionError(levelName);
4576 }
4577 }
4578 return vis;
4579 }
4580 // </editor-fold>
4582 // <editor-fold defaultstate="collapsed" desc="Signature Generation">
4584 public static abstract class SignatureGenerator {
4586 private final Types types;
4588 protected abstract void append(char ch);
4589 protected abstract void append(byte[] ba);
4590 protected abstract void append(Name name);
4591 protected void classReference(ClassSymbol c) { /* by default: no-op */ }
4593 protected SignatureGenerator(Types types) {
4594 this.types = types;
4595 }
4597 /**
4598 * Assemble signature of given type in string buffer.
4599 */
4600 public void assembleSig(Type type) {
4601 type = type.unannotatedType();
4602 switch (type.getTag()) {
4603 case BYTE:
4604 append('B');
4605 break;
4606 case SHORT:
4607 append('S');
4608 break;
4609 case CHAR:
4610 append('C');
4611 break;
4612 case INT:
4613 append('I');
4614 break;
4615 case LONG:
4616 append('J');
4617 break;
4618 case FLOAT:
4619 append('F');
4620 break;
4621 case DOUBLE:
4622 append('D');
4623 break;
4624 case BOOLEAN:
4625 append('Z');
4626 break;
4627 case VOID:
4628 append('V');
4629 break;
4630 case CLASS:
4631 append('L');
4632 assembleClassSig(type);
4633 append(';');
4634 break;
4635 case ARRAY:
4636 ArrayType at = (ArrayType) type;
4637 append('[');
4638 assembleSig(at.elemtype);
4639 break;
4640 case METHOD:
4641 MethodType mt = (MethodType) type;
4642 append('(');
4643 assembleSig(mt.argtypes);
4644 append(')');
4645 assembleSig(mt.restype);
4646 if (hasTypeVar(mt.thrown)) {
4647 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) {
4648 append('^');
4649 assembleSig(l.head);
4650 }
4651 }
4652 break;
4653 case WILDCARD: {
4654 Type.WildcardType ta = (Type.WildcardType) type;
4655 switch (ta.kind) {
4656 case SUPER:
4657 append('-');
4658 assembleSig(ta.type);
4659 break;
4660 case EXTENDS:
4661 append('+');
4662 assembleSig(ta.type);
4663 break;
4664 case UNBOUND:
4665 append('*');
4666 break;
4667 default:
4668 throw new AssertionError(ta.kind);
4669 }
4670 break;
4671 }
4672 case TYPEVAR:
4673 append('T');
4674 append(type.tsym.name);
4675 append(';');
4676 break;
4677 case FORALL:
4678 Type.ForAll ft = (Type.ForAll) type;
4679 assembleParamsSig(ft.tvars);
4680 assembleSig(ft.qtype);
4681 break;
4682 default:
4683 throw new AssertionError("typeSig " + type.getTag());
4684 }
4685 }
4687 public boolean hasTypeVar(List<Type> l) {
4688 while (l.nonEmpty()) {
4689 if (l.head.hasTag(TypeTag.TYPEVAR)) {
4690 return true;
4691 }
4692 l = l.tail;
4693 }
4694 return false;
4695 }
4697 public void assembleClassSig(Type type) {
4698 type = type.unannotatedType();
4699 ClassType ct = (ClassType) type;
4700 ClassSymbol c = (ClassSymbol) ct.tsym;
4701 classReference(c);
4702 Type outer = ct.getEnclosingType();
4703 if (outer.allparams().nonEmpty()) {
4704 boolean rawOuter =
4705 c.owner.kind == Kinds.MTH || // either a local class
4706 c.name == types.names.empty; // or anonymous
4707 assembleClassSig(rawOuter
4708 ? types.erasure(outer)
4709 : outer);
4710 append('.');
4711 Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname));
4712 append(rawOuter
4713 ? c.flatname.subName(c.owner.enclClass().flatname.getByteLength() + 1, c.flatname.getByteLength())
4714 : c.name);
4715 } else {
4716 append(externalize(c.flatname));
4717 }
4718 if (ct.getTypeArguments().nonEmpty()) {
4719 append('<');
4720 assembleSig(ct.getTypeArguments());
4721 append('>');
4722 }
4723 }
4725 public void assembleParamsSig(List<Type> typarams) {
4726 append('<');
4727 for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) {
4728 Type.TypeVar tvar = (Type.TypeVar) ts.head;
4729 append(tvar.tsym.name);
4730 List<Type> bounds = types.getBounds(tvar);
4731 if ((bounds.head.tsym.flags() & INTERFACE) != 0) {
4732 append(':');
4733 }
4734 for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) {
4735 append(':');
4736 assembleSig(l.head);
4737 }
4738 }
4739 append('>');
4740 }
4742 private void assembleSig(List<Type> types) {
4743 for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) {
4744 assembleSig(ts.head);
4745 }
4746 }
4747 }
4748 // </editor-fold>
4749 }
