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src/share/classes/com/sun/tools/javac/code/Types.java@4788eb38cac5
src/share/classes/com/sun/tools/javac/code/Types.java
Mon, 11 Nov 2013 09:47:46 -0500
- author
- emc
- date
- Mon, 11 Nov 2013 09:47:46 -0500
- changeset 2187
- 4788eb38cac5
- parent 2134
- b0c086cd4520
- child 2260
- fb870c70e774
- permissions
- -rw-r--r--
8027439: Compile-time error in the case of ((Integer[] & Serializable)new Integer[1]).getClass()
8027253: javac illegally accepts array as bound
Summary: backing out change allowing arrays in intersection types
Reviewed-by: vromero
1 /*
2 * Copyright (c) 2003, 2013, 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.util.*;
47 import static com.sun.tools.javac.code.BoundKind.*;
48 import static com.sun.tools.javac.code.Flags.*;
49 import static com.sun.tools.javac.code.Scope.*;
50 import static com.sun.tools.javac.code.Symbol.*;
51 import static com.sun.tools.javac.code.Type.*;
52 import static com.sun.tools.javac.code.TypeTag.*;
53 import static com.sun.tools.javac.jvm.ClassFile.externalize;
55 /**
56 * Utility class containing various operations on types.
57 *
58 * <p>Unless other names are more illustrative, the following naming
59 * conventions should be observed in this file:
60 *
61 * <dl>
62 * <dt>t</dt>
63 * <dd>If the first argument to an operation is a type, it should be named t.</dd>
64 * <dt>s</dt>
65 * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd>
66 * <dt>ts</dt>
67 * <dd>If an operations takes a list of types, the first should be named ts.</dd>
68 * <dt>ss</dt>
69 * <dd>A second list of types should be named ss.</dd>
70 * </dl>
71 *
72 * <p><b>This is NOT part of any supported API.
73 * If you write code that depends on this, you do so at your own risk.
74 * This code and its internal interfaces are subject to change or
75 * deletion without notice.</b>
76 */
77 public class Types {
78 protected static final Context.Key<Types> typesKey =
79 new Context.Key<Types>();
81 final Symtab syms;
82 final JavacMessages messages;
83 final Names names;
84 final boolean allowBoxing;
85 final boolean allowCovariantReturns;
86 final boolean allowObjectToPrimitiveCast;
87 final boolean allowDefaultMethods;
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 allowDefaultMethods = source.allowDefaultMethods();
115 reader = ClassReader.instance(context);
116 chk = Check.instance(context);
117 enter = Enter.instance(context);
118 capturedName = names.fromString("<captured wildcard>");
119 messages = JavacMessages.instance(context);
120 diags = JCDiagnostic.Factory.instance(context);
121 functionDescriptorLookupError = new FunctionDescriptorLookupError();
122 noWarnings = new Warner(null);
123 }
124 // </editor-fold>
126 // <editor-fold defaultstate="collapsed" desc="upperBound">
127 /**
128 * The "rvalue conversion".<br>
129 * The upper bound of most types is the type
130 * itself. Wildcards, on the other hand have upper
131 * and lower bounds.
132 * @param t a type
133 * @return the upper bound of the given type
134 */
135 public Type upperBound(Type t) {
136 return upperBound.visit(t).unannotatedType();
137 }
138 // where
139 private final MapVisitor<Void> upperBound = new MapVisitor<Void>() {
141 @Override
142 public Type visitWildcardType(WildcardType t, Void ignored) {
143 if (t.isSuperBound())
144 return t.bound == null ? syms.objectType : t.bound.bound;
145 else
146 return visit(t.type);
147 }
149 @Override
150 public Type visitCapturedType(CapturedType t, Void ignored) {
151 return visit(t.bound);
152 }
153 };
154 // </editor-fold>
156 // <editor-fold defaultstate="collapsed" desc="lowerBound">
157 /**
158 * The "lvalue conversion".<br>
159 * The lower bound of most types is the type
160 * itself. Wildcards, on the other hand have upper
161 * and lower bounds.
162 * @param t a type
163 * @return the lower bound of the given type
164 */
165 public Type lowerBound(Type t) {
166 return lowerBound.visit(t);
167 }
168 // where
169 private final MapVisitor<Void> lowerBound = new MapVisitor<Void>() {
171 @Override
172 public Type visitWildcardType(WildcardType t, Void ignored) {
173 return t.isExtendsBound() ? syms.botType : visit(t.type);
174 }
176 @Override
177 public Type visitCapturedType(CapturedType t, Void ignored) {
178 return visit(t.getLowerBound());
179 }
180 };
181 // </editor-fold>
183 // <editor-fold defaultstate="collapsed" desc="isUnbounded">
184 /**
185 * Checks that all the arguments to a class are unbounded
186 * wildcards or something else that doesn't make any restrictions
187 * on the arguments. If a class isUnbounded, a raw super- or
188 * subclass can be cast to it without a warning.
189 * @param t a type
190 * @return true iff the given type is unbounded or raw
191 */
192 public boolean isUnbounded(Type t) {
193 return isUnbounded.visit(t);
194 }
195 // where
196 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() {
198 public Boolean visitType(Type t, Void ignored) {
199 return true;
200 }
202 @Override
203 public Boolean visitClassType(ClassType t, Void ignored) {
204 List<Type> parms = t.tsym.type.allparams();
205 List<Type> args = t.allparams();
206 while (parms.nonEmpty()) {
207 WildcardType unb = new WildcardType(syms.objectType,
208 BoundKind.UNBOUND,
209 syms.boundClass,
210 (TypeVar)parms.head.unannotatedType());
211 if (!containsType(args.head, unb))
212 return false;
213 parms = parms.tail;
214 args = args.tail;
215 }
216 return true;
217 }
218 };
219 // </editor-fold>
221 // <editor-fold defaultstate="collapsed" desc="asSub">
222 /**
223 * Return the least specific subtype of t that starts with symbol
224 * sym. If none exists, return null. The least specific subtype
225 * is determined as follows:
226 *
227 * <p>If there is exactly one parameterized instance of sym that is a
228 * subtype of t, that parameterized instance is returned.<br>
229 * Otherwise, if the plain type or raw type `sym' is a subtype of
230 * type t, the type `sym' itself is returned. Otherwise, null is
231 * returned.
232 */
233 public Type asSub(Type t, Symbol sym) {
234 return asSub.visit(t, sym);
235 }
236 // where
237 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() {
239 public Type visitType(Type t, Symbol sym) {
240 return null;
241 }
243 @Override
244 public Type visitClassType(ClassType t, Symbol sym) {
245 if (t.tsym == sym)
246 return t;
247 Type base = asSuper(sym.type, t.tsym);
248 if (base == null)
249 return null;
250 ListBuffer<Type> from = new ListBuffer<Type>();
251 ListBuffer<Type> to = new ListBuffer<Type>();
252 try {
253 adapt(base, t, from, to);
254 } catch (AdaptFailure ex) {
255 return null;
256 }
257 Type res = subst(sym.type, from.toList(), to.toList());
258 if (!isSubtype(res, t))
259 return null;
260 ListBuffer<Type> openVars = new ListBuffer<Type>();
261 for (List<Type> l = sym.type.allparams();
262 l.nonEmpty(); l = l.tail)
263 if (res.contains(l.head) && !t.contains(l.head))
264 openVars.append(l.head);
265 if (openVars.nonEmpty()) {
266 if (t.isRaw()) {
267 // The subtype of a raw type is raw
268 res = erasure(res);
269 } else {
270 // Unbound type arguments default to ?
271 List<Type> opens = openVars.toList();
272 ListBuffer<Type> qs = new ListBuffer<Type>();
273 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) {
274 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND, syms.boundClass, (TypeVar) iter.head.unannotatedType()));
275 }
276 res = subst(res, opens, qs.toList());
277 }
278 }
279 return res;
280 }
282 @Override
283 public Type visitErrorType(ErrorType t, Symbol sym) {
284 return t;
285 }
286 };
287 // </editor-fold>
289 // <editor-fold defaultstate="collapsed" desc="isConvertible">
290 /**
291 * Is t a subtype of or convertible via boxing/unboxing
292 * conversion to s?
293 */
294 public boolean isConvertible(Type t, Type s, Warner warn) {
295 if (t.hasTag(ERROR)) {
296 return true;
297 }
298 boolean tPrimitive = t.isPrimitive();
299 boolean sPrimitive = s.isPrimitive();
300 if (tPrimitive == sPrimitive) {
301 return isSubtypeUnchecked(t, s, warn);
302 }
303 if (!allowBoxing) return false;
304 return tPrimitive
305 ? isSubtype(boxedClass(t).type, s)
306 : isSubtype(unboxedType(t), s);
307 }
309 /**
310 * Is t a subtype of or convertiable via boxing/unboxing
311 * convertions to s?
312 */
313 public boolean isConvertible(Type t, Type s) {
314 return isConvertible(t, s, noWarnings);
315 }
316 // </editor-fold>
318 // <editor-fold defaultstate="collapsed" desc="findSam">
320 /**
321 * Exception used to report a function descriptor lookup failure. The exception
322 * wraps a diagnostic that can be used to generate more details error
323 * messages.
324 */
325 public static class FunctionDescriptorLookupError extends RuntimeException {
326 private static final long serialVersionUID = 0;
328 JCDiagnostic diagnostic;
330 FunctionDescriptorLookupError() {
331 this.diagnostic = null;
332 }
334 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) {
335 this.diagnostic = diag;
336 return this;
337 }
339 public JCDiagnostic getDiagnostic() {
340 return diagnostic;
341 }
342 }
344 /**
345 * A cache that keeps track of function descriptors associated with given
346 * functional interfaces.
347 */
348 class DescriptorCache {
350 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<TypeSymbol, Entry>();
352 class FunctionDescriptor {
353 Symbol descSym;
355 FunctionDescriptor(Symbol descSym) {
356 this.descSym = descSym;
357 }
359 public Symbol getSymbol() {
360 return descSym;
361 }
363 public Type getType(Type site) {
364 site = removeWildcards(site);
365 if (!chk.checkValidGenericType(site)) {
366 //if the inferred functional interface type is not well-formed,
367 //or if it's not a subtype of the original target, issue an error
368 throw failure(diags.fragment("no.suitable.functional.intf.inst", site));
369 }
370 return memberType(site, descSym);
371 }
372 }
374 class Entry {
375 final FunctionDescriptor cachedDescRes;
376 final int prevMark;
378 public Entry(FunctionDescriptor cachedDescRes,
379 int prevMark) {
380 this.cachedDescRes = cachedDescRes;
381 this.prevMark = prevMark;
382 }
384 boolean matches(int mark) {
385 return this.prevMark == mark;
386 }
387 }
389 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError {
390 Entry e = _map.get(origin);
391 CompoundScope members = membersClosure(origin.type, false);
392 if (e == null ||
393 !e.matches(members.getMark())) {
394 FunctionDescriptor descRes = findDescriptorInternal(origin, members);
395 _map.put(origin, new Entry(descRes, members.getMark()));
396 return descRes;
397 }
398 else {
399 return e.cachedDescRes;
400 }
401 }
403 /**
404 * Compute the function descriptor associated with a given functional interface
405 */
406 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin,
407 CompoundScope membersCache) throws FunctionDescriptorLookupError {
408 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0) {
409 //t must be an interface
410 throw failure("not.a.functional.intf", origin);
411 }
413 final ListBuffer<Symbol> abstracts = new ListBuffer<>();
414 for (Symbol sym : membersCache.getElements(new DescriptorFilter(origin))) {
415 Type mtype = memberType(origin.type, sym);
416 if (abstracts.isEmpty() ||
417 (sym.name == abstracts.first().name &&
418 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) {
419 abstracts.append(sym);
420 } else {
421 //the target method(s) should be the only abstract members of t
422 throw failure("not.a.functional.intf.1", origin,
423 diags.fragment("incompatible.abstracts", Kinds.kindName(origin), origin));
424 }
425 }
426 if (abstracts.isEmpty()) {
427 //t must define a suitable non-generic method
428 throw failure("not.a.functional.intf.1", origin,
429 diags.fragment("no.abstracts", Kinds.kindName(origin), origin));
430 } else if (abstracts.size() == 1) {
431 return new FunctionDescriptor(abstracts.first());
432 } else { // size > 1
433 FunctionDescriptor descRes = mergeDescriptors(origin, abstracts.toList());
434 if (descRes == null) {
435 //we can get here if the functional interface is ill-formed
436 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>();
437 for (Symbol desc : abstracts) {
438 String key = desc.type.getThrownTypes().nonEmpty() ?
439 "descriptor.throws" : "descriptor";
440 descriptors.append(diags.fragment(key, desc.name,
441 desc.type.getParameterTypes(),
442 desc.type.getReturnType(),
443 desc.type.getThrownTypes()));
444 }
445 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors =
446 new JCDiagnostic.MultilineDiagnostic(diags.fragment("incompatible.descs.in.functional.intf",
447 Kinds.kindName(origin), origin), descriptors.toList());
448 throw failure(incompatibleDescriptors);
449 }
450 return descRes;
451 }
452 }
454 /**
455 * Compute a synthetic type for the target descriptor given a list
456 * of override-equivalent methods in the functional interface type.
457 * The resulting method type is a method type that is override-equivalent
458 * and return-type substitutable with each method in the original list.
459 */
460 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) {
461 //pick argument types - simply take the signature that is a
462 //subsignature of all other signatures in the list (as per JLS 8.4.2)
463 List<Symbol> mostSpecific = List.nil();
464 outer: for (Symbol msym1 : methodSyms) {
465 Type mt1 = memberType(origin.type, msym1);
466 for (Symbol msym2 : methodSyms) {
467 Type mt2 = memberType(origin.type, msym2);
468 if (!isSubSignature(mt1, mt2)) {
469 continue outer;
470 }
471 }
472 mostSpecific = mostSpecific.prepend(msym1);
473 }
474 if (mostSpecific.isEmpty()) {
475 return null;
476 }
479 //pick return types - this is done in two phases: (i) first, the most
480 //specific return type is chosen using strict subtyping; if this fails,
481 //a second attempt is made using return type substitutability (see JLS 8.4.5)
482 boolean phase2 = false;
483 Symbol bestSoFar = null;
484 while (bestSoFar == null) {
485 outer: for (Symbol msym1 : mostSpecific) {
486 Type mt1 = memberType(origin.type, msym1);
487 for (Symbol msym2 : methodSyms) {
488 Type mt2 = memberType(origin.type, msym2);
489 if (phase2 ?
490 !returnTypeSubstitutable(mt1, mt2) :
491 !isSubtypeInternal(mt1.getReturnType(), mt2.getReturnType())) {
492 continue outer;
493 }
494 }
495 bestSoFar = msym1;
496 }
497 if (phase2) {
498 break;
499 } else {
500 phase2 = true;
501 }
502 }
503 if (bestSoFar == null) return null;
505 //merge thrown types - form the intersection of all the thrown types in
506 //all the signatures in the list
507 boolean toErase = !bestSoFar.type.hasTag(FORALL);
508 List<Type> thrown = null;
509 Type mt1 = memberType(origin.type, bestSoFar);
510 for (Symbol msym2 : methodSyms) {
511 Type mt2 = memberType(origin.type, msym2);
512 List<Type> thrown_mt2 = mt2.getThrownTypes();
513 if (toErase) {
514 thrown_mt2 = erasure(thrown_mt2);
515 } else {
516 /* If bestSoFar is generic then all the methods are generic.
517 * The opposite is not true: a non generic method can override
518 * a generic method (raw override) so it's safe to cast mt1 and
519 * mt2 to ForAll.
520 */
521 ForAll fa1 = (ForAll)mt1;
522 ForAll fa2 = (ForAll)mt2;
523 thrown_mt2 = subst(thrown_mt2, fa2.tvars, fa1.tvars);
524 }
525 thrown = (thrown == null) ?
526 thrown_mt2 :
527 chk.intersect(thrown_mt2, thrown);
528 }
530 final List<Type> thrown1 = thrown;
531 return new FunctionDescriptor(bestSoFar) {
532 @Override
533 public Type getType(Type origin) {
534 Type mt = memberType(origin, getSymbol());
535 return createMethodTypeWithThrown(mt, thrown1);
536 }
537 };
538 }
540 boolean isSubtypeInternal(Type s, Type t) {
541 return (s.isPrimitive() && t.isPrimitive()) ?
542 isSameType(t, s) :
543 isSubtype(s, t);
544 }
546 FunctionDescriptorLookupError failure(String msg, Object... args) {
547 return failure(diags.fragment(msg, args));
548 }
550 FunctionDescriptorLookupError failure(JCDiagnostic diag) {
551 return functionDescriptorLookupError.setMessage(diag);
552 }
553 }
555 private DescriptorCache descCache = new DescriptorCache();
557 /**
558 * Find the method descriptor associated to this class symbol - if the
559 * symbol 'origin' is not a functional interface, an exception is thrown.
560 */
561 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError {
562 return descCache.get(origin).getSymbol();
563 }
565 /**
566 * Find the type of the method descriptor associated to this class symbol -
567 * if the symbol 'origin' is not a functional interface, an exception is thrown.
568 */
569 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError {
570 return descCache.get(origin.tsym).getType(origin);
571 }
573 /**
574 * Is given type a functional interface?
575 */
576 public boolean isFunctionalInterface(TypeSymbol tsym) {
577 try {
578 findDescriptorSymbol(tsym);
579 return true;
580 } catch (FunctionDescriptorLookupError ex) {
581 return false;
582 }
583 }
585 public boolean isFunctionalInterface(Type site) {
586 try {
587 findDescriptorType(site);
588 return true;
589 } catch (FunctionDescriptorLookupError ex) {
590 return false;
591 }
592 }
594 public Type removeWildcards(Type site) {
595 Type capturedSite = capture(site);
596 if (capturedSite != site) {
597 Type formalInterface = site.tsym.type;
598 ListBuffer<Type> typeargs = new ListBuffer<>();
599 List<Type> actualTypeargs = site.getTypeArguments();
600 List<Type> capturedTypeargs = capturedSite.getTypeArguments();
601 //simply replace the wildcards with its bound
602 for (Type t : formalInterface.getTypeArguments()) {
603 if (actualTypeargs.head.hasTag(WILDCARD)) {
604 WildcardType wt = (WildcardType)actualTypeargs.head.unannotatedType();
605 Type bound;
606 switch (wt.kind) {
607 case EXTENDS:
608 case UNBOUND:
609 CapturedType capVar = (CapturedType)capturedTypeargs.head.unannotatedType();
610 //use declared bound if it doesn't depend on formal type-args
611 bound = capVar.bound.containsAny(capturedSite.getTypeArguments()) ?
612 wt.type : capVar.bound;
613 break;
614 default:
615 bound = wt.type;
616 }
617 typeargs.append(bound);
618 } else {
619 typeargs.append(actualTypeargs.head);
620 }
621 actualTypeargs = actualTypeargs.tail;
622 capturedTypeargs = capturedTypeargs.tail;
623 }
624 return subst(formalInterface, formalInterface.getTypeArguments(), typeargs.toList());
625 } else {
626 return site;
627 }
628 }
630 /**
631 * Create a symbol for a class that implements a given functional interface
632 * and overrides its functional descriptor. This routine is used for two
633 * main purposes: (i) checking well-formedness of a functional interface;
634 * (ii) perform functional interface bridge calculation.
635 */
636 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, List<Type> targets, long cflags) {
637 if (targets.isEmpty() || !isFunctionalInterface(targets.head)) {
638 return null;
639 }
640 Symbol descSym = findDescriptorSymbol(targets.head.tsym);
641 Type descType = findDescriptorType(targets.head);
642 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass());
643 csym.completer = null;
644 csym.members_field = new Scope(csym);
645 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym);
646 csym.members_field.enter(instDescSym);
647 Type.ClassType ctype = new Type.ClassType(Type.noType, List.<Type>nil(), csym);
648 ctype.supertype_field = syms.objectType;
649 ctype.interfaces_field = targets;
650 csym.type = ctype;
651 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile;
652 return csym;
653 }
655 /**
656 * Find the minimal set of methods that are overridden by the functional
657 * descriptor in 'origin'. All returned methods are assumed to have different
658 * erased signatures.
659 */
660 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) {
661 Assert.check(isFunctionalInterface(origin));
662 Symbol descSym = findDescriptorSymbol(origin);
663 CompoundScope members = membersClosure(origin.type, false);
664 ListBuffer<Symbol> overridden = new ListBuffer<>();
665 outer: for (Symbol m2 : members.getElementsByName(descSym.name, bridgeFilter)) {
666 if (m2 == descSym) continue;
667 else if (descSym.overrides(m2, origin, Types.this, false)) {
668 for (Symbol m3 : overridden) {
669 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) ||
670 (m3.overrides(m2, origin, Types.this, false) &&
671 (pendingBridges((ClassSymbol)origin, m3.enclClass()) ||
672 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) {
673 continue outer;
674 }
675 }
676 overridden.add(m2);
677 }
678 }
679 return overridden.toList();
680 }
681 //where
682 private Filter<Symbol> bridgeFilter = new Filter<Symbol>() {
683 public boolean accepts(Symbol t) {
684 return t.kind == Kinds.MTH &&
685 t.name != names.init &&
686 t.name != names.clinit &&
687 (t.flags() & SYNTHETIC) == 0;
688 }
689 };
690 private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) {
691 //a symbol will be completed from a classfile if (a) symbol has
692 //an associated file object with CLASS kind and (b) the symbol has
693 //not been entered
694 if (origin.classfile != null &&
695 origin.classfile.getKind() == JavaFileObject.Kind.CLASS &&
696 enter.getEnv(origin) == null) {
697 return false;
698 }
699 if (origin == s) {
700 return true;
701 }
702 for (Type t : interfaces(origin.type)) {
703 if (pendingBridges((ClassSymbol)t.tsym, s)) {
704 return true;
705 }
706 }
707 return false;
708 }
709 // </editor-fold>
711 /**
712 * Scope filter used to skip methods that should be ignored (such as methods
713 * overridden by j.l.Object) during function interface conversion interface check
714 */
715 class DescriptorFilter implements Filter<Symbol> {
717 TypeSymbol origin;
719 DescriptorFilter(TypeSymbol origin) {
720 this.origin = origin;
721 }
723 @Override
724 public boolean accepts(Symbol sym) {
725 return sym.kind == Kinds.MTH &&
726 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT &&
727 !overridesObjectMethod(origin, sym) &&
728 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0;
729 }
730 };
732 // <editor-fold defaultstate="collapsed" desc="isSubtype">
733 /**
734 * Is t an unchecked subtype of s?
735 */
736 public boolean isSubtypeUnchecked(Type t, Type s) {
737 return isSubtypeUnchecked(t, s, noWarnings);
738 }
739 /**
740 * Is t an unchecked subtype of s?
741 */
742 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) {
743 boolean result = isSubtypeUncheckedInternal(t, s, warn);
744 if (result) {
745 checkUnsafeVarargsConversion(t, s, warn);
746 }
747 return result;
748 }
749 //where
750 private boolean isSubtypeUncheckedInternal(Type t, Type s, Warner warn) {
751 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) {
752 t = t.unannotatedType();
753 s = s.unannotatedType();
754 if (((ArrayType)t).elemtype.isPrimitive()) {
755 return isSameType(elemtype(t), elemtype(s));
756 } else {
757 return isSubtypeUnchecked(elemtype(t), elemtype(s), warn);
758 }
759 } else if (isSubtype(t, s)) {
760 return true;
761 } else if (t.hasTag(TYPEVAR)) {
762 return isSubtypeUnchecked(t.getUpperBound(), s, warn);
763 } else if (!s.isRaw()) {
764 Type t2 = asSuper(t, s.tsym);
765 if (t2 != null && t2.isRaw()) {
766 if (isReifiable(s)) {
767 warn.silentWarn(LintCategory.UNCHECKED);
768 } else {
769 warn.warn(LintCategory.UNCHECKED);
770 }
771 return true;
772 }
773 }
774 return false;
775 }
777 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) {
778 if (!t.hasTag(ARRAY) || isReifiable(t)) {
779 return;
780 }
781 t = t.unannotatedType();
782 s = s.unannotatedType();
783 ArrayType from = (ArrayType)t;
784 boolean shouldWarn = false;
785 switch (s.getTag()) {
786 case ARRAY:
787 ArrayType to = (ArrayType)s;
788 shouldWarn = from.isVarargs() &&
789 !to.isVarargs() &&
790 !isReifiable(from);
791 break;
792 case CLASS:
793 shouldWarn = from.isVarargs();
794 break;
795 }
796 if (shouldWarn) {
797 warn.warn(LintCategory.VARARGS);
798 }
799 }
801 /**
802 * Is t a subtype of s?<br>
803 * (not defined for Method and ForAll types)
804 */
805 final public boolean isSubtype(Type t, Type s) {
806 return isSubtype(t, s, true);
807 }
808 final public boolean isSubtypeNoCapture(Type t, Type s) {
809 return isSubtype(t, s, false);
810 }
811 public boolean isSubtype(Type t, Type s, boolean capture) {
812 if (t == s)
813 return true;
815 t = t.unannotatedType();
816 s = s.unannotatedType();
818 if (t == s)
819 return true;
821 if (s.isPartial())
822 return isSuperType(s, t);
824 if (s.isCompound()) {
825 for (Type s2 : interfaces(s).prepend(supertype(s))) {
826 if (!isSubtype(t, s2, capture))
827 return false;
828 }
829 return true;
830 }
832 Type lower = lowerBound(s);
833 if (s != lower)
834 return isSubtype(capture ? capture(t) : t, lower, false);
836 return isSubtype.visit(capture ? capture(t) : t, s);
837 }
838 // where
839 private TypeRelation isSubtype = new TypeRelation()
840 {
841 @Override
842 public Boolean visitType(Type t, Type s) {
843 switch (t.getTag()) {
844 case BYTE:
845 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag()));
846 case CHAR:
847 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag()));
848 case SHORT: case INT: case LONG:
849 case FLOAT: case DOUBLE:
850 return t.getTag().isSubRangeOf(s.getTag());
851 case BOOLEAN: case VOID:
852 return t.hasTag(s.getTag());
853 case TYPEVAR:
854 return isSubtypeNoCapture(t.getUpperBound(), s);
855 case BOT:
856 return
857 s.hasTag(BOT) || s.hasTag(CLASS) ||
858 s.hasTag(ARRAY) || s.hasTag(TYPEVAR);
859 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495)
860 case NONE:
861 return false;
862 default:
863 throw new AssertionError("isSubtype " + t.getTag());
864 }
865 }
867 private Set<TypePair> cache = new HashSet<TypePair>();
869 private boolean containsTypeRecursive(Type t, Type s) {
870 TypePair pair = new TypePair(t, s);
871 if (cache.add(pair)) {
872 try {
873 return containsType(t.getTypeArguments(),
874 s.getTypeArguments());
875 } finally {
876 cache.remove(pair);
877 }
878 } else {
879 return containsType(t.getTypeArguments(),
880 rewriteSupers(s).getTypeArguments());
881 }
882 }
884 private Type rewriteSupers(Type t) {
885 if (!t.isParameterized())
886 return t;
887 ListBuffer<Type> from = new ListBuffer<>();
888 ListBuffer<Type> to = new ListBuffer<>();
889 adaptSelf(t, from, to);
890 if (from.isEmpty())
891 return t;
892 ListBuffer<Type> rewrite = new ListBuffer<>();
893 boolean changed = false;
894 for (Type orig : to.toList()) {
895 Type s = rewriteSupers(orig);
896 if (s.isSuperBound() && !s.isExtendsBound()) {
897 s = new WildcardType(syms.objectType,
898 BoundKind.UNBOUND,
899 syms.boundClass);
900 changed = true;
901 } else if (s != orig) {
902 s = new WildcardType(upperBound(s),
903 BoundKind.EXTENDS,
904 syms.boundClass);
905 changed = true;
906 }
907 rewrite.append(s);
908 }
909 if (changed)
910 return subst(t.tsym.type, from.toList(), rewrite.toList());
911 else
912 return t;
913 }
915 @Override
916 public Boolean visitClassType(ClassType t, Type s) {
917 Type sup = asSuper(t, s.tsym);
918 return sup != null
919 && sup.tsym == s.tsym
920 // You're not allowed to write
921 // Vector<Object> vec = new Vector<String>();
922 // But with wildcards you can write
923 // Vector<? extends Object> vec = new Vector<String>();
924 // which means that subtype checking must be done
925 // here instead of same-type checking (via containsType).
926 && (!s.isParameterized() || containsTypeRecursive(s, sup))
927 && isSubtypeNoCapture(sup.getEnclosingType(),
928 s.getEnclosingType());
929 }
931 @Override
932 public Boolean visitArrayType(ArrayType t, Type s) {
933 if (s.hasTag(ARRAY)) {
934 if (t.elemtype.isPrimitive())
935 return isSameType(t.elemtype, elemtype(s));
936 else
937 return isSubtypeNoCapture(t.elemtype, elemtype(s));
938 }
940 if (s.hasTag(CLASS)) {
941 Name sname = s.tsym.getQualifiedName();
942 return sname == names.java_lang_Object
943 || sname == names.java_lang_Cloneable
944 || sname == names.java_io_Serializable;
945 }
947 return false;
948 }
950 @Override
951 public Boolean visitUndetVar(UndetVar t, Type s) {
952 //todo: test against origin needed? or replace with substitution?
953 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
954 return true;
955 } else if (s.hasTag(BOT)) {
956 //if 's' is 'null' there's no instantiated type U for which
957 //U <: s (but 'null' itself, which is not a valid type)
958 return false;
959 }
961 t.addBound(InferenceBound.UPPER, s, Types.this);
962 return true;
963 }
965 @Override
966 public Boolean visitErrorType(ErrorType t, Type s) {
967 return true;
968 }
969 };
971 /**
972 * Is t a subtype of every type in given list `ts'?<br>
973 * (not defined for Method and ForAll types)<br>
974 * Allows unchecked conversions.
975 */
976 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) {
977 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
978 if (!isSubtypeUnchecked(t, l.head, warn))
979 return false;
980 return true;
981 }
983 /**
984 * Are corresponding elements of ts subtypes of ss? If lists are
985 * of different length, return false.
986 */
987 public boolean isSubtypes(List<Type> ts, List<Type> ss) {
988 while (ts.tail != null && ss.tail != null
989 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
990 isSubtype(ts.head, ss.head)) {
991 ts = ts.tail;
992 ss = ss.tail;
993 }
994 return ts.tail == null && ss.tail == null;
995 /*inlined: ts.isEmpty() && ss.isEmpty();*/
996 }
998 /**
999 * Are corresponding elements of ts subtypes of ss, allowing
1000 * unchecked conversions? If lists are of different length,
1001 * return false.
1002 **/
1003 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) {
1004 while (ts.tail != null && ss.tail != null
1005 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1006 isSubtypeUnchecked(ts.head, ss.head, warn)) {
1007 ts = ts.tail;
1008 ss = ss.tail;
1009 }
1010 return ts.tail == null && ss.tail == null;
1011 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1012 }
1013 // </editor-fold>
1015 // <editor-fold defaultstate="collapsed" desc="isSuperType">
1016 /**
1017 * Is t a supertype of s?
1018 */
1019 public boolean isSuperType(Type t, Type s) {
1020 switch (t.getTag()) {
1021 case ERROR:
1022 return true;
1023 case UNDETVAR: {
1024 UndetVar undet = (UndetVar)t;
1025 if (t == s ||
1026 undet.qtype == s ||
1027 s.hasTag(ERROR) ||
1028 s.hasTag(BOT)) {
1029 return true;
1030 }
1031 undet.addBound(InferenceBound.LOWER, s, this);
1032 return true;
1033 }
1034 default:
1035 return isSubtype(s, t);
1036 }
1037 }
1038 // </editor-fold>
1040 // <editor-fold defaultstate="collapsed" desc="isSameType">
1041 /**
1042 * Are corresponding elements of the lists the same type? If
1043 * lists are of different length, return false.
1044 */
1045 public boolean isSameTypes(List<Type> ts, List<Type> ss) {
1046 return isSameTypes(ts, ss, false);
1047 }
1048 public boolean isSameTypes(List<Type> ts, List<Type> ss, boolean strict) {
1049 while (ts.tail != null && ss.tail != null
1050 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1051 isSameType(ts.head, ss.head, strict)) {
1052 ts = ts.tail;
1053 ss = ss.tail;
1054 }
1055 return ts.tail == null && ss.tail == null;
1056 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1057 }
1059 /**
1060 * A polymorphic signature method (JLS SE 7, 8.4.1) is a method that
1061 * (i) is declared in the java.lang.invoke.MethodHandle class, (ii) takes
1062 * a single variable arity parameter (iii) whose declared type is Object[],
1063 * (iv) has a return type of Object and (v) is native.
1064 */
1065 public boolean isSignaturePolymorphic(MethodSymbol msym) {
1066 List<Type> argtypes = msym.type.getParameterTypes();
1067 return (msym.flags_field & NATIVE) != 0 &&
1068 msym.owner == syms.methodHandleType.tsym &&
1069 argtypes.tail.tail == null &&
1070 argtypes.head.hasTag(TypeTag.ARRAY) &&
1071 msym.type.getReturnType().tsym == syms.objectType.tsym &&
1072 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym;
1073 }
1075 /**
1076 * Is t the same type as s?
1077 */
1078 public boolean isSameType(Type t, Type s) {
1079 return isSameType(t, s, false);
1080 }
1081 public boolean isSameType(Type t, Type s, boolean strict) {
1082 return strict ?
1083 isSameTypeStrict.visit(t, s) :
1084 isSameTypeLoose.visit(t, s);
1085 }
1086 public boolean isSameAnnotatedType(Type t, Type s) {
1087 return isSameAnnotatedType.visit(t, s);
1088 }
1089 // where
1090 abstract class SameTypeVisitor extends TypeRelation {
1092 public Boolean visitType(Type t, Type s) {
1093 if (t == s)
1094 return true;
1096 if (s.isPartial())
1097 return visit(s, t);
1099 switch (t.getTag()) {
1100 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1101 case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE:
1102 return t.hasTag(s.getTag());
1103 case TYPEVAR: {
1104 if (s.hasTag(TYPEVAR)) {
1105 //type-substitution does not preserve type-var types
1106 //check that type var symbols and bounds are indeed the same
1107 return sameTypeVars((TypeVar)t.unannotatedType(), (TypeVar)s.unannotatedType());
1108 }
1109 else {
1110 //special case for s == ? super X, where upper(s) = u
1111 //check that u == t, where u has been set by Type.withTypeVar
1112 return s.isSuperBound() &&
1113 !s.isExtendsBound() &&
1114 visit(t, upperBound(s));
1115 }
1116 }
1117 default:
1118 throw new AssertionError("isSameType " + t.getTag());
1119 }
1120 }
1122 abstract boolean sameTypeVars(TypeVar tv1, TypeVar tv2);
1124 @Override
1125 public Boolean visitWildcardType(WildcardType t, Type s) {
1126 if (s.isPartial())
1127 return visit(s, t);
1128 else
1129 return false;
1130 }
1132 @Override
1133 public Boolean visitClassType(ClassType t, Type s) {
1134 if (t == s)
1135 return true;
1137 if (s.isPartial())
1138 return visit(s, t);
1140 if (s.isSuperBound() && !s.isExtendsBound())
1141 return visit(t, upperBound(s)) && visit(t, lowerBound(s));
1143 if (t.isCompound() && s.isCompound()) {
1144 if (!visit(supertype(t), supertype(s)))
1145 return false;
1147 HashSet<UniqueType> set = new HashSet<UniqueType>();
1148 for (Type x : interfaces(t))
1149 set.add(new UniqueType(x.unannotatedType(), Types.this));
1150 for (Type x : interfaces(s)) {
1151 if (!set.remove(new UniqueType(x.unannotatedType(), Types.this)))
1152 return false;
1153 }
1154 return (set.isEmpty());
1155 }
1156 return t.tsym == s.tsym
1157 && visit(t.getEnclosingType(), s.getEnclosingType())
1158 && containsTypes(t.getTypeArguments(), s.getTypeArguments());
1159 }
1161 abstract protected boolean containsTypes(List<Type> ts1, List<Type> ts2);
1163 @Override
1164 public Boolean visitArrayType(ArrayType t, Type s) {
1165 if (t == s)
1166 return true;
1168 if (s.isPartial())
1169 return visit(s, t);
1171 return s.hasTag(ARRAY)
1172 && containsTypeEquivalent(t.elemtype, elemtype(s));
1173 }
1175 @Override
1176 public Boolean visitMethodType(MethodType t, Type s) {
1177 // isSameType for methods does not take thrown
1178 // exceptions into account!
1179 return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType());
1180 }
1182 @Override
1183 public Boolean visitPackageType(PackageType t, Type s) {
1184 return t == s;
1185 }
1187 @Override
1188 public Boolean visitForAll(ForAll t, Type s) {
1189 if (!s.hasTag(FORALL)) {
1190 return false;
1191 }
1193 ForAll forAll = (ForAll)s;
1194 return hasSameBounds(t, forAll)
1195 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
1196 }
1198 @Override
1199 public Boolean visitUndetVar(UndetVar t, Type s) {
1200 if (s.hasTag(WILDCARD)) {
1201 // FIXME, this might be leftovers from before capture conversion
1202 return false;
1203 }
1205 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1206 return true;
1207 }
1209 t.addBound(InferenceBound.EQ, s, Types.this);
1211 return true;
1212 }
1214 @Override
1215 public Boolean visitErrorType(ErrorType t, Type s) {
1216 return true;
1217 }
1218 }
1220 /**
1221 * Standard type-equality relation - type variables are considered
1222 * equals if they share the same type symbol.
1223 */
1224 TypeRelation isSameTypeLoose = new LooseSameTypeVisitor();
1226 private class LooseSameTypeVisitor extends SameTypeVisitor {
1227 @Override
1228 boolean sameTypeVars(TypeVar tv1, TypeVar tv2) {
1229 return tv1.tsym == tv2.tsym && visit(tv1.getUpperBound(), tv2.getUpperBound());
1230 }
1231 @Override
1232 protected boolean containsTypes(List<Type> ts1, List<Type> ts2) {
1233 return containsTypeEquivalent(ts1, ts2);
1234 }
1235 };
1237 /**
1238 * Strict type-equality relation - type variables are considered
1239 * equals if they share the same object identity.
1240 */
1241 TypeRelation isSameTypeStrict = new SameTypeVisitor() {
1242 @Override
1243 boolean sameTypeVars(TypeVar tv1, TypeVar tv2) {
1244 return tv1 == tv2;
1245 }
1246 @Override
1247 protected boolean containsTypes(List<Type> ts1, List<Type> ts2) {
1248 return isSameTypes(ts1, ts2, true);
1249 }
1251 @Override
1252 public Boolean visitWildcardType(WildcardType t, Type s) {
1253 if (!s.hasTag(WILDCARD)) {
1254 return false;
1255 } else {
1256 WildcardType t2 = (WildcardType)s.unannotatedType();
1257 return t.kind == t2.kind &&
1258 isSameType(t.type, t2.type, true);
1259 }
1260 }
1261 };
1263 /**
1264 * A version of LooseSameTypeVisitor that takes AnnotatedTypes
1265 * into account.
1266 */
1267 TypeRelation isSameAnnotatedType = new LooseSameTypeVisitor() {
1268 @Override
1269 public Boolean visitAnnotatedType(AnnotatedType t, Type s) {
1270 if (!s.isAnnotated())
1271 return false;
1272 if (!t.getAnnotationMirrors().containsAll(s.getAnnotationMirrors()))
1273 return false;
1274 if (!s.getAnnotationMirrors().containsAll(t.getAnnotationMirrors()))
1275 return false;
1276 return visit(t.unannotatedType(), s);
1277 }
1278 };
1279 // </editor-fold>
1281 // <editor-fold defaultstate="collapsed" desc="Contains Type">
1282 public boolean containedBy(Type t, Type s) {
1283 switch (t.getTag()) {
1284 case UNDETVAR:
1285 if (s.hasTag(WILDCARD)) {
1286 UndetVar undetvar = (UndetVar)t;
1287 WildcardType wt = (WildcardType)s.unannotatedType();
1288 switch(wt.kind) {
1289 case UNBOUND: //similar to ? extends Object
1290 case EXTENDS: {
1291 Type bound = upperBound(s);
1292 undetvar.addBound(InferenceBound.UPPER, bound, this);
1293 break;
1294 }
1295 case SUPER: {
1296 Type bound = lowerBound(s);
1297 undetvar.addBound(InferenceBound.LOWER, bound, this);
1298 break;
1299 }
1300 }
1301 return true;
1302 } else {
1303 return isSameType(t, s);
1304 }
1305 case ERROR:
1306 return true;
1307 default:
1308 return containsType(s, t);
1309 }
1310 }
1312 boolean containsType(List<Type> ts, List<Type> ss) {
1313 while (ts.nonEmpty() && ss.nonEmpty()
1314 && containsType(ts.head, ss.head)) {
1315 ts = ts.tail;
1316 ss = ss.tail;
1317 }
1318 return ts.isEmpty() && ss.isEmpty();
1319 }
1321 /**
1322 * Check if t contains s.
1323 *
1324 * <p>T contains S if:
1325 *
1326 * <p>{@code L(T) <: L(S) && U(S) <: U(T)}
1327 *
1328 * <p>This relation is only used by ClassType.isSubtype(), that
1329 * is,
1330 *
1331 * <p>{@code C<S> <: C<T> if T contains S.}
1332 *
1333 * <p>Because of F-bounds, this relation can lead to infinite
1334 * recursion. Thus we must somehow break that recursion. Notice
1335 * that containsType() is only called from ClassType.isSubtype().
1336 * Since the arguments have already been checked against their
1337 * bounds, we know:
1338 *
1339 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)}
1340 *
1341 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)}
1342 *
1343 * @param t a type
1344 * @param s a type
1345 */
1346 public boolean containsType(Type t, Type s) {
1347 return containsType.visit(t, s);
1348 }
1349 // where
1350 private TypeRelation containsType = new TypeRelation() {
1352 private Type U(Type t) {
1353 while (t.hasTag(WILDCARD)) {
1354 WildcardType w = (WildcardType)t.unannotatedType();
1355 if (w.isSuperBound())
1356 return w.bound == null ? syms.objectType : w.bound.bound;
1357 else
1358 t = w.type;
1359 }
1360 return t;
1361 }
1363 private Type L(Type t) {
1364 while (t.hasTag(WILDCARD)) {
1365 WildcardType w = (WildcardType)t.unannotatedType();
1366 if (w.isExtendsBound())
1367 return syms.botType;
1368 else
1369 t = w.type;
1370 }
1371 return t;
1372 }
1374 public Boolean visitType(Type t, Type s) {
1375 if (s.isPartial())
1376 return containedBy(s, t);
1377 else
1378 return isSameType(t, s);
1379 }
1381 // void debugContainsType(WildcardType t, Type s) {
1382 // System.err.println();
1383 // System.err.format(" does %s contain %s?%n", t, s);
1384 // System.err.format(" %s U(%s) <: U(%s) %s = %s%n",
1385 // upperBound(s), s, t, U(t),
1386 // t.isSuperBound()
1387 // || isSubtypeNoCapture(upperBound(s), U(t)));
1388 // System.err.format(" %s L(%s) <: L(%s) %s = %s%n",
1389 // L(t), t, s, lowerBound(s),
1390 // t.isExtendsBound()
1391 // || isSubtypeNoCapture(L(t), lowerBound(s)));
1392 // System.err.println();
1393 // }
1395 @Override
1396 public Boolean visitWildcardType(WildcardType t, Type s) {
1397 if (s.isPartial())
1398 return containedBy(s, t);
1399 else {
1400 // debugContainsType(t, s);
1401 return isSameWildcard(t, s)
1402 || isCaptureOf(s, t)
1403 || ((t.isExtendsBound() || isSubtypeNoCapture(L(t), lowerBound(s))) &&
1404 (t.isSuperBound() || isSubtypeNoCapture(upperBound(s), U(t))));
1405 }
1406 }
1408 @Override
1409 public Boolean visitUndetVar(UndetVar t, Type s) {
1410 if (!s.hasTag(WILDCARD)) {
1411 return isSameType(t, s);
1412 } else {
1413 return false;
1414 }
1415 }
1417 @Override
1418 public Boolean visitErrorType(ErrorType t, Type s) {
1419 return true;
1420 }
1421 };
1423 public boolean isCaptureOf(Type s, WildcardType t) {
1424 if (!s.hasTag(TYPEVAR) || !((TypeVar)s.unannotatedType()).isCaptured())
1425 return false;
1426 return isSameWildcard(t, ((CapturedType)s.unannotatedType()).wildcard);
1427 }
1429 public boolean isSameWildcard(WildcardType t, Type s) {
1430 if (!s.hasTag(WILDCARD))
1431 return false;
1432 WildcardType w = (WildcardType)s.unannotatedType();
1433 return w.kind == t.kind && w.type == t.type;
1434 }
1436 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) {
1437 while (ts.nonEmpty() && ss.nonEmpty()
1438 && containsTypeEquivalent(ts.head, ss.head)) {
1439 ts = ts.tail;
1440 ss = ss.tail;
1441 }
1442 return ts.isEmpty() && ss.isEmpty();
1443 }
1444 // </editor-fold>
1446 /**
1447 * Can t and s be compared for equality? Any primitive ==
1448 * primitive or primitive == object comparisons here are an error.
1449 * Unboxing and correct primitive == primitive comparisons are
1450 * already dealt with in Attr.visitBinary.
1451 *
1452 */
1453 public boolean isEqualityComparable(Type s, Type t, Warner warn) {
1454 if (t.isNumeric() && s.isNumeric())
1455 return true;
1457 boolean tPrimitive = t.isPrimitive();
1458 boolean sPrimitive = s.isPrimitive();
1459 if (!tPrimitive && !sPrimitive) {
1460 return isCastable(s, t, warn) || isCastable(t, s, warn);
1461 } else {
1462 return false;
1463 }
1464 }
1466 // <editor-fold defaultstate="collapsed" desc="isCastable">
1467 public boolean isCastable(Type t, Type s) {
1468 return isCastable(t, s, noWarnings);
1469 }
1471 /**
1472 * Is t is castable to s?<br>
1473 * s is assumed to be an erased type.<br>
1474 * (not defined for Method and ForAll types).
1475 */
1476 public boolean isCastable(Type t, Type s, Warner warn) {
1477 if (t == s)
1478 return true;
1480 if (t.isPrimitive() != s.isPrimitive())
1481 return allowBoxing && (
1482 isConvertible(t, s, warn)
1483 || (allowObjectToPrimitiveCast &&
1484 s.isPrimitive() &&
1485 isSubtype(boxedClass(s).type, t)));
1486 if (warn != warnStack.head) {
1487 try {
1488 warnStack = warnStack.prepend(warn);
1489 checkUnsafeVarargsConversion(t, s, warn);
1490 return isCastable.visit(t,s);
1491 } finally {
1492 warnStack = warnStack.tail;
1493 }
1494 } else {
1495 return isCastable.visit(t,s);
1496 }
1497 }
1498 // where
1499 private TypeRelation isCastable = new TypeRelation() {
1501 public Boolean visitType(Type t, Type s) {
1502 if (s.hasTag(ERROR))
1503 return true;
1505 switch (t.getTag()) {
1506 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1507 case DOUBLE:
1508 return s.isNumeric();
1509 case BOOLEAN:
1510 return s.hasTag(BOOLEAN);
1511 case VOID:
1512 return false;
1513 case BOT:
1514 return isSubtype(t, s);
1515 default:
1516 throw new AssertionError();
1517 }
1518 }
1520 @Override
1521 public Boolean visitWildcardType(WildcardType t, Type s) {
1522 return isCastable(upperBound(t), s, warnStack.head);
1523 }
1525 @Override
1526 public Boolean visitClassType(ClassType t, Type s) {
1527 if (s.hasTag(ERROR) || s.hasTag(BOT))
1528 return true;
1530 if (s.hasTag(TYPEVAR)) {
1531 if (isCastable(t, s.getUpperBound(), noWarnings)) {
1532 warnStack.head.warn(LintCategory.UNCHECKED);
1533 return true;
1534 } else {
1535 return false;
1536 }
1537 }
1539 if (t.isCompound() || s.isCompound()) {
1540 return !t.isCompound() ?
1541 visitIntersectionType((IntersectionClassType)s.unannotatedType(), t, true) :
1542 visitIntersectionType((IntersectionClassType)t.unannotatedType(), s, false);
1543 }
1545 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) {
1546 boolean upcast;
1547 if ((upcast = isSubtype(erasure(t), erasure(s)))
1548 || isSubtype(erasure(s), erasure(t))) {
1549 if (!upcast && s.hasTag(ARRAY)) {
1550 if (!isReifiable(s))
1551 warnStack.head.warn(LintCategory.UNCHECKED);
1552 return true;
1553 } else if (s.isRaw()) {
1554 return true;
1555 } else if (t.isRaw()) {
1556 if (!isUnbounded(s))
1557 warnStack.head.warn(LintCategory.UNCHECKED);
1558 return true;
1559 }
1560 // Assume |a| <: |b|
1561 final Type a = upcast ? t : s;
1562 final Type b = upcast ? s : t;
1563 final boolean HIGH = true;
1564 final boolean LOW = false;
1565 final boolean DONT_REWRITE_TYPEVARS = false;
1566 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS);
1567 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS);
1568 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS);
1569 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS);
1570 Type lowSub = asSub(bLow, aLow.tsym);
1571 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1572 if (highSub == null) {
1573 final boolean REWRITE_TYPEVARS = true;
1574 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS);
1575 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS);
1576 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS);
1577 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS);
1578 lowSub = asSub(bLow, aLow.tsym);
1579 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1580 }
1581 if (highSub != null) {
1582 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) {
1583 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym);
1584 }
1585 if (!disjointTypes(aHigh.allparams(), highSub.allparams())
1586 && !disjointTypes(aHigh.allparams(), lowSub.allparams())
1587 && !disjointTypes(aLow.allparams(), highSub.allparams())
1588 && !disjointTypes(aLow.allparams(), lowSub.allparams())) {
1589 if (upcast ? giveWarning(a, b) :
1590 giveWarning(b, a))
1591 warnStack.head.warn(LintCategory.UNCHECKED);
1592 return true;
1593 }
1594 }
1595 if (isReifiable(s))
1596 return isSubtypeUnchecked(a, b);
1597 else
1598 return isSubtypeUnchecked(a, b, warnStack.head);
1599 }
1601 // Sidecast
1602 if (s.hasTag(CLASS)) {
1603 if ((s.tsym.flags() & INTERFACE) != 0) {
1604 return ((t.tsym.flags() & FINAL) == 0)
1605 ? sideCast(t, s, warnStack.head)
1606 : sideCastFinal(t, s, warnStack.head);
1607 } else if ((t.tsym.flags() & INTERFACE) != 0) {
1608 return ((s.tsym.flags() & FINAL) == 0)
1609 ? sideCast(t, s, warnStack.head)
1610 : sideCastFinal(t, s, warnStack.head);
1611 } else {
1612 // unrelated class types
1613 return false;
1614 }
1615 }
1616 }
1617 return false;
1618 }
1620 boolean visitIntersectionType(IntersectionClassType ict, Type s, boolean reverse) {
1621 Warner warn = noWarnings;
1622 for (Type c : ict.getComponents()) {
1623 warn.clear();
1624 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn))
1625 return false;
1626 }
1627 if (warn.hasLint(LintCategory.UNCHECKED))
1628 warnStack.head.warn(LintCategory.UNCHECKED);
1629 return true;
1630 }
1632 @Override
1633 public Boolean visitArrayType(ArrayType t, Type s) {
1634 switch (s.getTag()) {
1635 case ERROR:
1636 case BOT:
1637 return true;
1638 case TYPEVAR:
1639 if (isCastable(s, t, noWarnings)) {
1640 warnStack.head.warn(LintCategory.UNCHECKED);
1641 return true;
1642 } else {
1643 return false;
1644 }
1645 case CLASS:
1646 return isSubtype(t, s);
1647 case ARRAY:
1648 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) {
1649 return elemtype(t).hasTag(elemtype(s).getTag());
1650 } else {
1651 return visit(elemtype(t), elemtype(s));
1652 }
1653 default:
1654 return false;
1655 }
1656 }
1658 @Override
1659 public Boolean visitTypeVar(TypeVar t, Type s) {
1660 switch (s.getTag()) {
1661 case ERROR:
1662 case BOT:
1663 return true;
1664 case TYPEVAR:
1665 if (isSubtype(t, s)) {
1666 return true;
1667 } else if (isCastable(t.bound, s, noWarnings)) {
1668 warnStack.head.warn(LintCategory.UNCHECKED);
1669 return true;
1670 } else {
1671 return false;
1672 }
1673 default:
1674 return isCastable(t.bound, s, warnStack.head);
1675 }
1676 }
1678 @Override
1679 public Boolean visitErrorType(ErrorType t, Type s) {
1680 return true;
1681 }
1682 };
1683 // </editor-fold>
1685 // <editor-fold defaultstate="collapsed" desc="disjointTypes">
1686 public boolean disjointTypes(List<Type> ts, List<Type> ss) {
1687 while (ts.tail != null && ss.tail != null) {
1688 if (disjointType(ts.head, ss.head)) return true;
1689 ts = ts.tail;
1690 ss = ss.tail;
1691 }
1692 return false;
1693 }
1695 /**
1696 * Two types or wildcards are considered disjoint if it can be
1697 * proven that no type can be contained in both. It is
1698 * conservative in that it is allowed to say that two types are
1699 * not disjoint, even though they actually are.
1700 *
1701 * The type {@code C<X>} is castable to {@code C<Y>} exactly if
1702 * {@code X} and {@code Y} are not disjoint.
1703 */
1704 public boolean disjointType(Type t, Type s) {
1705 return disjointType.visit(t, s);
1706 }
1707 // where
1708 private TypeRelation disjointType = new TypeRelation() {
1710 private Set<TypePair> cache = new HashSet<TypePair>();
1712 @Override
1713 public Boolean visitType(Type t, Type s) {
1714 if (s.hasTag(WILDCARD))
1715 return visit(s, t);
1716 else
1717 return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t);
1718 }
1720 private boolean isCastableRecursive(Type t, Type s) {
1721 TypePair pair = new TypePair(t, s);
1722 if (cache.add(pair)) {
1723 try {
1724 return Types.this.isCastable(t, s);
1725 } finally {
1726 cache.remove(pair);
1727 }
1728 } else {
1729 return true;
1730 }
1731 }
1733 private boolean notSoftSubtypeRecursive(Type t, Type s) {
1734 TypePair pair = new TypePair(t, s);
1735 if (cache.add(pair)) {
1736 try {
1737 return Types.this.notSoftSubtype(t, s);
1738 } finally {
1739 cache.remove(pair);
1740 }
1741 } else {
1742 return false;
1743 }
1744 }
1746 @Override
1747 public Boolean visitWildcardType(WildcardType t, Type s) {
1748 if (t.isUnbound())
1749 return false;
1751 if (!s.hasTag(WILDCARD)) {
1752 if (t.isExtendsBound())
1753 return notSoftSubtypeRecursive(s, t.type);
1754 else
1755 return notSoftSubtypeRecursive(t.type, s);
1756 }
1758 if (s.isUnbound())
1759 return false;
1761 if (t.isExtendsBound()) {
1762 if (s.isExtendsBound())
1763 return !isCastableRecursive(t.type, upperBound(s));
1764 else if (s.isSuperBound())
1765 return notSoftSubtypeRecursive(lowerBound(s), t.type);
1766 } else if (t.isSuperBound()) {
1767 if (s.isExtendsBound())
1768 return notSoftSubtypeRecursive(t.type, upperBound(s));
1769 }
1770 return false;
1771 }
1772 };
1773 // </editor-fold>
1775 // <editor-fold defaultstate="collapsed" desc="lowerBoundArgtypes">
1776 /**
1777 * Returns the lower bounds of the formals of a method.
1778 */
1779 public List<Type> lowerBoundArgtypes(Type t) {
1780 return lowerBounds(t.getParameterTypes());
1781 }
1782 public List<Type> lowerBounds(List<Type> ts) {
1783 return map(ts, lowerBoundMapping);
1784 }
1785 private final Mapping lowerBoundMapping = new Mapping("lowerBound") {
1786 public Type apply(Type t) {
1787 return lowerBound(t);
1788 }
1789 };
1790 // </editor-fold>
1792 // <editor-fold defaultstate="collapsed" desc="notSoftSubtype">
1793 /**
1794 * This relation answers the question: is impossible that
1795 * something of type `t' can be a subtype of `s'? This is
1796 * different from the question "is `t' not a subtype of `s'?"
1797 * when type variables are involved: Integer is not a subtype of T
1798 * where {@code <T extends Number>} but it is not true that Integer cannot
1799 * possibly be a subtype of T.
1800 */
1801 public boolean notSoftSubtype(Type t, Type s) {
1802 if (t == s) return false;
1803 if (t.hasTag(TYPEVAR)) {
1804 TypeVar tv = (TypeVar) t;
1805 return !isCastable(tv.bound,
1806 relaxBound(s),
1807 noWarnings);
1808 }
1809 if (!s.hasTag(WILDCARD))
1810 s = upperBound(s);
1812 return !isSubtype(t, relaxBound(s));
1813 }
1815 private Type relaxBound(Type t) {
1816 if (t.hasTag(TYPEVAR)) {
1817 while (t.hasTag(TYPEVAR))
1818 t = t.getUpperBound();
1819 t = rewriteQuantifiers(t, true, true);
1820 }
1821 return t;
1822 }
1823 // </editor-fold>
1825 // <editor-fold defaultstate="collapsed" desc="isReifiable">
1826 public boolean isReifiable(Type t) {
1827 return isReifiable.visit(t);
1828 }
1829 // where
1830 private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() {
1832 public Boolean visitType(Type t, Void ignored) {
1833 return true;
1834 }
1836 @Override
1837 public Boolean visitClassType(ClassType t, Void ignored) {
1838 if (t.isCompound())
1839 return false;
1840 else {
1841 if (!t.isParameterized())
1842 return true;
1844 for (Type param : t.allparams()) {
1845 if (!param.isUnbound())
1846 return false;
1847 }
1848 return true;
1849 }
1850 }
1852 @Override
1853 public Boolean visitArrayType(ArrayType t, Void ignored) {
1854 return visit(t.elemtype);
1855 }
1857 @Override
1858 public Boolean visitTypeVar(TypeVar t, Void ignored) {
1859 return false;
1860 }
1861 };
1862 // </editor-fold>
1864 // <editor-fold defaultstate="collapsed" desc="Array Utils">
1865 public boolean isArray(Type t) {
1866 while (t.hasTag(WILDCARD))
1867 t = upperBound(t);
1868 return t.hasTag(ARRAY);
1869 }
1871 /**
1872 * The element type of an array.
1873 */
1874 public Type elemtype(Type t) {
1875 switch (t.getTag()) {
1876 case WILDCARD:
1877 return elemtype(upperBound(t));
1878 case ARRAY:
1879 t = t.unannotatedType();
1880 return ((ArrayType)t).elemtype;
1881 case FORALL:
1882 return elemtype(((ForAll)t).qtype);
1883 case ERROR:
1884 return t;
1885 default:
1886 return null;
1887 }
1888 }
1890 public Type elemtypeOrType(Type t) {
1891 Type elemtype = elemtype(t);
1892 return elemtype != null ?
1893 elemtype :
1894 t;
1895 }
1897 /**
1898 * Mapping to take element type of an arraytype
1899 */
1900 private Mapping elemTypeFun = new Mapping ("elemTypeFun") {
1901 public Type apply(Type t) { return elemtype(t); }
1902 };
1904 /**
1905 * The number of dimensions of an array type.
1906 */
1907 public int dimensions(Type t) {
1908 int result = 0;
1909 while (t.hasTag(ARRAY)) {
1910 result++;
1911 t = elemtype(t);
1912 }
1913 return result;
1914 }
1916 /**
1917 * Returns an ArrayType with the component type t
1918 *
1919 * @param t The component type of the ArrayType
1920 * @return the ArrayType for the given component
1921 */
1922 public ArrayType makeArrayType(Type t) {
1923 if (t.hasTag(VOID) || t.hasTag(PACKAGE)) {
1924 Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString());
1925 }
1926 return new ArrayType(t, syms.arrayClass);
1927 }
1928 // </editor-fold>
1930 // <editor-fold defaultstate="collapsed" desc="asSuper">
1931 /**
1932 * Return the (most specific) base type of t that starts with the
1933 * given symbol. If none exists, return null.
1934 *
1935 * @param t a type
1936 * @param sym a symbol
1937 */
1938 public Type asSuper(Type t, Symbol sym) {
1939 return asSuper.visit(t, sym);
1940 }
1941 // where
1942 private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() {
1944 public Type visitType(Type t, Symbol sym) {
1945 return null;
1946 }
1948 @Override
1949 public Type visitClassType(ClassType t, Symbol sym) {
1950 if (t.tsym == sym)
1951 return t;
1953 Type st = supertype(t);
1954 if (st.hasTag(CLASS) || st.hasTag(TYPEVAR) || st.hasTag(ERROR)) {
1955 Type x = asSuper(st, sym);
1956 if (x != null)
1957 return x;
1958 }
1959 if ((sym.flags() & INTERFACE) != 0) {
1960 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
1961 Type x = asSuper(l.head, sym);
1962 if (x != null)
1963 return x;
1964 }
1965 }
1966 return null;
1967 }
1969 @Override
1970 public Type visitArrayType(ArrayType t, Symbol sym) {
1971 return isSubtype(t, sym.type) ? sym.type : null;
1972 }
1974 @Override
1975 public Type visitTypeVar(TypeVar t, Symbol sym) {
1976 if (t.tsym == sym)
1977 return t;
1978 else
1979 return asSuper(t.bound, sym);
1980 }
1982 @Override
1983 public Type visitErrorType(ErrorType t, Symbol sym) {
1984 return t;
1985 }
1986 };
1988 /**
1989 * Return the base type of t or any of its outer types that starts
1990 * with the given symbol. If none exists, return null.
1991 *
1992 * @param t a type
1993 * @param sym a symbol
1994 */
1995 public Type asOuterSuper(Type t, Symbol sym) {
1996 switch (t.getTag()) {
1997 case CLASS:
1998 do {
1999 Type s = asSuper(t, sym);
2000 if (s != null) return s;
2001 t = t.getEnclosingType();
2002 } while (t.hasTag(CLASS));
2003 return null;
2004 case ARRAY:
2005 return isSubtype(t, sym.type) ? sym.type : null;
2006 case TYPEVAR:
2007 return asSuper(t, sym);
2008 case ERROR:
2009 return t;
2010 default:
2011 return null;
2012 }
2013 }
2015 /**
2016 * Return the base type of t or any of its enclosing types that
2017 * starts with the given symbol. If none exists, return null.
2018 *
2019 * @param t a type
2020 * @param sym a symbol
2021 */
2022 public Type asEnclosingSuper(Type t, Symbol sym) {
2023 switch (t.getTag()) {
2024 case CLASS:
2025 do {
2026 Type s = asSuper(t, sym);
2027 if (s != null) return s;
2028 Type outer = t.getEnclosingType();
2029 t = (outer.hasTag(CLASS)) ? outer :
2030 (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type :
2031 Type.noType;
2032 } while (t.hasTag(CLASS));
2033 return null;
2034 case ARRAY:
2035 return isSubtype(t, sym.type) ? sym.type : null;
2036 case TYPEVAR:
2037 return asSuper(t, sym);
2038 case ERROR:
2039 return t;
2040 default:
2041 return null;
2042 }
2043 }
2044 // </editor-fold>
2046 // <editor-fold defaultstate="collapsed" desc="memberType">
2047 /**
2048 * The type of given symbol, seen as a member of t.
2049 *
2050 * @param t a type
2051 * @param sym a symbol
2052 */
2053 public Type memberType(Type t, Symbol sym) {
2054 return (sym.flags() & STATIC) != 0
2055 ? sym.type
2056 : memberType.visit(t, sym);
2057 }
2058 // where
2059 private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() {
2061 public Type visitType(Type t, Symbol sym) {
2062 return sym.type;
2063 }
2065 @Override
2066 public Type visitWildcardType(WildcardType t, Symbol sym) {
2067 return memberType(upperBound(t), sym);
2068 }
2070 @Override
2071 public Type visitClassType(ClassType t, Symbol sym) {
2072 Symbol owner = sym.owner;
2073 long flags = sym.flags();
2074 if (((flags & STATIC) == 0) && owner.type.isParameterized()) {
2075 Type base = asOuterSuper(t, owner);
2076 //if t is an intersection type T = CT & I1 & I2 ... & In
2077 //its supertypes CT, I1, ... In might contain wildcards
2078 //so we need to go through capture conversion
2079 base = t.isCompound() ? capture(base) : base;
2080 if (base != null) {
2081 List<Type> ownerParams = owner.type.allparams();
2082 List<Type> baseParams = base.allparams();
2083 if (ownerParams.nonEmpty()) {
2084 if (baseParams.isEmpty()) {
2085 // then base is a raw type
2086 return erasure(sym.type);
2087 } else {
2088 return subst(sym.type, ownerParams, baseParams);
2089 }
2090 }
2091 }
2092 }
2093 return sym.type;
2094 }
2096 @Override
2097 public Type visitTypeVar(TypeVar t, Symbol sym) {
2098 return memberType(t.bound, sym);
2099 }
2101 @Override
2102 public Type visitErrorType(ErrorType t, Symbol sym) {
2103 return t;
2104 }
2105 };
2106 // </editor-fold>
2108 // <editor-fold defaultstate="collapsed" desc="isAssignable">
2109 public boolean isAssignable(Type t, Type s) {
2110 return isAssignable(t, s, noWarnings);
2111 }
2113 /**
2114 * Is t assignable to s?<br>
2115 * Equivalent to subtype except for constant values and raw
2116 * types.<br>
2117 * (not defined for Method and ForAll types)
2118 */
2119 public boolean isAssignable(Type t, Type s, Warner warn) {
2120 if (t.hasTag(ERROR))
2121 return true;
2122 if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) {
2123 int value = ((Number)t.constValue()).intValue();
2124 switch (s.getTag()) {
2125 case BYTE:
2126 if (Byte.MIN_VALUE <= value && value <= Byte.MAX_VALUE)
2127 return true;
2128 break;
2129 case CHAR:
2130 if (Character.MIN_VALUE <= value && value <= Character.MAX_VALUE)
2131 return true;
2132 break;
2133 case SHORT:
2134 if (Short.MIN_VALUE <= value && value <= Short.MAX_VALUE)
2135 return true;
2136 break;
2137 case INT:
2138 return true;
2139 case CLASS:
2140 switch (unboxedType(s).getTag()) {
2141 case BYTE:
2142 case CHAR:
2143 case SHORT:
2144 return isAssignable(t, unboxedType(s), warn);
2145 }
2146 break;
2147 }
2148 }
2149 return isConvertible(t, s, warn);
2150 }
2151 // </editor-fold>
2153 // <editor-fold defaultstate="collapsed" desc="erasure">
2154 /**
2155 * The erasure of t {@code |t|} -- the type that results when all
2156 * type parameters in t are deleted.
2157 */
2158 public Type erasure(Type t) {
2159 return eraseNotNeeded(t)? t : erasure(t, false);
2160 }
2161 //where
2162 private boolean eraseNotNeeded(Type t) {
2163 // We don't want to erase primitive types and String type as that
2164 // operation is idempotent. Also, erasing these could result in loss
2165 // of information such as constant values attached to such types.
2166 return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym);
2167 }
2169 private Type erasure(Type t, boolean recurse) {
2170 if (t.isPrimitive())
2171 return t; /* fast special case */
2172 else
2173 return erasure.visit(t, recurse);
2174 }
2175 // where
2176 private SimpleVisitor<Type, Boolean> erasure = new SimpleVisitor<Type, Boolean>() {
2177 public Type visitType(Type t, Boolean recurse) {
2178 if (t.isPrimitive())
2179 return t; /*fast special case*/
2180 else
2181 return t.map(recurse ? erasureRecFun : erasureFun);
2182 }
2184 @Override
2185 public Type visitWildcardType(WildcardType t, Boolean recurse) {
2186 return erasure(upperBound(t), recurse);
2187 }
2189 @Override
2190 public Type visitClassType(ClassType t, Boolean recurse) {
2191 Type erased = t.tsym.erasure(Types.this);
2192 if (recurse) {
2193 erased = new ErasedClassType(erased.getEnclosingType(),erased.tsym);
2194 }
2195 return erased;
2196 }
2198 @Override
2199 public Type visitTypeVar(TypeVar t, Boolean recurse) {
2200 return erasure(t.bound, recurse);
2201 }
2203 @Override
2204 public Type visitErrorType(ErrorType t, Boolean recurse) {
2205 return t;
2206 }
2208 @Override
2209 public Type visitAnnotatedType(AnnotatedType t, Boolean recurse) {
2210 Type erased = erasure(t.unannotatedType(), recurse);
2211 if (erased.isAnnotated()) {
2212 // This can only happen when the underlying type is a
2213 // type variable and the upper bound of it is annotated.
2214 // The annotation on the type variable overrides the one
2215 // on the bound.
2216 erased = ((AnnotatedType)erased).unannotatedType();
2217 }
2218 return erased.annotatedType(t.getAnnotationMirrors());
2219 }
2220 };
2222 private Mapping erasureFun = new Mapping ("erasure") {
2223 public Type apply(Type t) { return erasure(t); }
2224 };
2226 private Mapping erasureRecFun = new Mapping ("erasureRecursive") {
2227 public Type apply(Type t) { return erasureRecursive(t); }
2228 };
2230 public List<Type> erasure(List<Type> ts) {
2231 return Type.map(ts, erasureFun);
2232 }
2234 public Type erasureRecursive(Type t) {
2235 return erasure(t, true);
2236 }
2238 public List<Type> erasureRecursive(List<Type> ts) {
2239 return Type.map(ts, erasureRecFun);
2240 }
2241 // </editor-fold>
2243 // <editor-fold defaultstate="collapsed" desc="makeCompoundType">
2244 /**
2245 * Make a compound type from non-empty list of types
2246 *
2247 * @param bounds the types from which the compound type is formed
2248 * @param supertype is objectType if all bounds are interfaces,
2249 * null otherwise.
2250 */
2251 public Type makeCompoundType(List<Type> bounds) {
2252 return makeCompoundType(bounds, bounds.head.tsym.isInterface());
2253 }
2254 public Type makeCompoundType(List<Type> bounds, boolean allInterfaces) {
2255 Assert.check(bounds.nonEmpty());
2256 Type firstExplicitBound = bounds.head;
2257 if (allInterfaces) {
2258 bounds = bounds.prepend(syms.objectType);
2259 }
2260 ClassSymbol bc =
2261 new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC,
2262 Type.moreInfo
2263 ? names.fromString(bounds.toString())
2264 : names.empty,
2265 null,
2266 syms.noSymbol);
2267 bc.type = new IntersectionClassType(bounds, bc, allInterfaces);
2268 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ?
2269 syms.objectType : // error condition, recover
2270 erasure(firstExplicitBound);
2271 bc.members_field = new Scope(bc);
2272 return bc.type;
2273 }
2275 /**
2276 * A convenience wrapper for {@link #makeCompoundType(List)}; the
2277 * arguments are converted to a list and passed to the other
2278 * method. Note that this might cause a symbol completion.
2279 * Hence, this version of makeCompoundType may not be called
2280 * during a classfile read.
2281 */
2282 public Type makeCompoundType(Type bound1, Type bound2) {
2283 return makeCompoundType(List.of(bound1, bound2));
2284 }
2285 // </editor-fold>
2287 // <editor-fold defaultstate="collapsed" desc="supertype">
2288 public Type supertype(Type t) {
2289 return supertype.visit(t);
2290 }
2291 // where
2292 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() {
2294 public Type visitType(Type t, Void ignored) {
2295 // A note on wildcards: there is no good way to
2296 // determine a supertype for a super bounded wildcard.
2297 return null;
2298 }
2300 @Override
2301 public Type visitClassType(ClassType t, Void ignored) {
2302 if (t.supertype_field == null) {
2303 Type supertype = ((ClassSymbol)t.tsym).getSuperclass();
2304 // An interface has no superclass; its supertype is Object.
2305 if (t.isInterface())
2306 supertype = ((ClassType)t.tsym.type).supertype_field;
2307 if (t.supertype_field == null) {
2308 List<Type> actuals = classBound(t).allparams();
2309 List<Type> formals = t.tsym.type.allparams();
2310 if (t.hasErasedSupertypes()) {
2311 t.supertype_field = erasureRecursive(supertype);
2312 } else if (formals.nonEmpty()) {
2313 t.supertype_field = subst(supertype, formals, actuals);
2314 }
2315 else {
2316 t.supertype_field = supertype;
2317 }
2318 }
2319 }
2320 return t.supertype_field;
2321 }
2323 /**
2324 * The supertype is always a class type. If the type
2325 * variable's bounds start with a class type, this is also
2326 * the supertype. Otherwise, the supertype is
2327 * java.lang.Object.
2328 */
2329 @Override
2330 public Type visitTypeVar(TypeVar t, Void ignored) {
2331 if (t.bound.hasTag(TYPEVAR) ||
2332 (!t.bound.isCompound() && !t.bound.isInterface())) {
2333 return t.bound;
2334 } else {
2335 return supertype(t.bound);
2336 }
2337 }
2339 @Override
2340 public Type visitArrayType(ArrayType t, Void ignored) {
2341 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType))
2342 return arraySuperType();
2343 else
2344 return new ArrayType(supertype(t.elemtype), t.tsym);
2345 }
2347 @Override
2348 public Type visitErrorType(ErrorType t, Void ignored) {
2349 return Type.noType;
2350 }
2351 };
2352 // </editor-fold>
2354 // <editor-fold defaultstate="collapsed" desc="interfaces">
2355 /**
2356 * Return the interfaces implemented by this class.
2357 */
2358 public List<Type> interfaces(Type t) {
2359 return interfaces.visit(t);
2360 }
2361 // where
2362 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() {
2364 public List<Type> visitType(Type t, Void ignored) {
2365 return List.nil();
2366 }
2368 @Override
2369 public List<Type> visitClassType(ClassType t, Void ignored) {
2370 if (t.interfaces_field == null) {
2371 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces();
2372 if (t.interfaces_field == null) {
2373 // If t.interfaces_field is null, then t must
2374 // be a parameterized type (not to be confused
2375 // with a generic type declaration).
2376 // Terminology:
2377 // Parameterized type: List<String>
2378 // Generic type declaration: class List<E> { ... }
2379 // So t corresponds to List<String> and
2380 // t.tsym.type corresponds to List<E>.
2381 // The reason t must be parameterized type is
2382 // that completion will happen as a side
2383 // effect of calling
2384 // ClassSymbol.getInterfaces. Since
2385 // t.interfaces_field is null after
2386 // completion, we can assume that t is not the
2387 // type of a class/interface declaration.
2388 Assert.check(t != t.tsym.type, t);
2389 List<Type> actuals = t.allparams();
2390 List<Type> formals = t.tsym.type.allparams();
2391 if (t.hasErasedSupertypes()) {
2392 t.interfaces_field = erasureRecursive(interfaces);
2393 } else if (formals.nonEmpty()) {
2394 t.interfaces_field =
2395 upperBounds(subst(interfaces, formals, actuals));
2396 }
2397 else {
2398 t.interfaces_field = interfaces;
2399 }
2400 }
2401 }
2402 return t.interfaces_field;
2403 }
2405 @Override
2406 public List<Type> visitTypeVar(TypeVar t, Void ignored) {
2407 if (t.bound.isCompound())
2408 return interfaces(t.bound);
2410 if (t.bound.isInterface())
2411 return List.of(t.bound);
2413 return List.nil();
2414 }
2415 };
2417 public List<Type> directSupertypes(Type t) {
2418 return directSupertypes.visit(t);
2419 }
2420 // where
2421 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() {
2423 public List<Type> visitType(final Type type, final Void ignored) {
2424 if (!type.isCompound()) {
2425 final Type sup = supertype(type);
2426 return (sup == Type.noType || sup == type || sup == null)
2427 ? interfaces(type)
2428 : interfaces(type).prepend(sup);
2429 } else {
2430 return visitIntersectionType((IntersectionClassType) type);
2431 }
2432 }
2434 private List<Type> visitIntersectionType(final IntersectionClassType it) {
2435 return it.getExplicitComponents();
2436 }
2438 };
2440 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) {
2441 for (Type i2 : interfaces(origin.type)) {
2442 if (isym == i2.tsym) return true;
2443 }
2444 return false;
2445 }
2446 // </editor-fold>
2448 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw">
2449 Map<Type,Boolean> isDerivedRawCache = new HashMap<Type,Boolean>();
2451 public boolean isDerivedRaw(Type t) {
2452 Boolean result = isDerivedRawCache.get(t);
2453 if (result == null) {
2454 result = isDerivedRawInternal(t);
2455 isDerivedRawCache.put(t, result);
2456 }
2457 return result;
2458 }
2460 public boolean isDerivedRawInternal(Type t) {
2461 if (t.isErroneous())
2462 return false;
2463 return
2464 t.isRaw() ||
2465 supertype(t) != null && isDerivedRaw(supertype(t)) ||
2466 isDerivedRaw(interfaces(t));
2467 }
2469 public boolean isDerivedRaw(List<Type> ts) {
2470 List<Type> l = ts;
2471 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail;
2472 return l.nonEmpty();
2473 }
2474 // </editor-fold>
2476 // <editor-fold defaultstate="collapsed" desc="setBounds">
2477 /**
2478 * Set the bounds field of the given type variable to reflect a
2479 * (possibly multiple) list of bounds.
2480 * @param t a type variable
2481 * @param bounds the bounds, must be nonempty
2482 * @param supertype is objectType if all bounds are interfaces,
2483 * null otherwise.
2484 */
2485 public void setBounds(TypeVar t, List<Type> bounds) {
2486 setBounds(t, bounds, bounds.head.tsym.isInterface());
2487 }
2489 /**
2490 * Same as {@link #setBounds(Type.TypeVar,List,Type)}, except that
2491 * third parameter is computed directly, as follows: if all
2492 * all bounds are interface types, the computed supertype is Object,
2493 * otherwise the supertype is simply left null (in this case, the supertype
2494 * is assumed to be the head of the bound list passed as second argument).
2495 * Note that this check might cause a symbol completion. Hence, this version of
2496 * setBounds may not be called during a classfile read.
2497 */
2498 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) {
2499 t.bound = bounds.tail.isEmpty() ?
2500 bounds.head :
2501 makeCompoundType(bounds, allInterfaces);
2502 t.rank_field = -1;
2503 }
2504 // </editor-fold>
2506 // <editor-fold defaultstate="collapsed" desc="getBounds">
2507 /**
2508 * Return list of bounds of the given type variable.
2509 */
2510 public List<Type> getBounds(TypeVar t) {
2511 if (t.bound.hasTag(NONE))
2512 return List.nil();
2513 else if (t.bound.isErroneous() || !t.bound.isCompound())
2514 return List.of(t.bound);
2515 else if ((erasure(t).tsym.flags() & INTERFACE) == 0)
2516 return interfaces(t).prepend(supertype(t));
2517 else
2518 // No superclass was given in bounds.
2519 // In this case, supertype is Object, erasure is first interface.
2520 return interfaces(t);
2521 }
2522 // </editor-fold>
2524 // <editor-fold defaultstate="collapsed" desc="classBound">
2525 /**
2526 * If the given type is a (possibly selected) type variable,
2527 * return the bounding class of this type, otherwise return the
2528 * type itself.
2529 */
2530 public Type classBound(Type t) {
2531 return classBound.visit(t);
2532 }
2533 // where
2534 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() {
2536 public Type visitType(Type t, Void ignored) {
2537 return t;
2538 }
2540 @Override
2541 public Type visitClassType(ClassType t, Void ignored) {
2542 Type outer1 = classBound(t.getEnclosingType());
2543 if (outer1 != t.getEnclosingType())
2544 return new ClassType(outer1, t.getTypeArguments(), t.tsym);
2545 else
2546 return t;
2547 }
2549 @Override
2550 public Type visitTypeVar(TypeVar t, Void ignored) {
2551 return classBound(supertype(t));
2552 }
2554 @Override
2555 public Type visitErrorType(ErrorType t, Void ignored) {
2556 return t;
2557 }
2558 };
2559 // </editor-fold>
2561 // <editor-fold defaultstate="collapsed" desc="sub signature / override equivalence">
2562 /**
2563 * Returns true iff the first signature is a <em>sub
2564 * signature</em> of the other. This is <b>not</b> an equivalence
2565 * relation.
2566 *
2567 * @jls section 8.4.2.
2568 * @see #overrideEquivalent(Type t, Type s)
2569 * @param t first signature (possibly raw).
2570 * @param s second signature (could be subjected to erasure).
2571 * @return true if t is a sub signature of s.
2572 */
2573 public boolean isSubSignature(Type t, Type s) {
2574 return isSubSignature(t, s, true);
2575 }
2577 public boolean isSubSignature(Type t, Type s, boolean strict) {
2578 return hasSameArgs(t, s, strict) || hasSameArgs(t, erasure(s), strict);
2579 }
2581 /**
2582 * Returns true iff these signatures are related by <em>override
2583 * equivalence</em>. This is the natural extension of
2584 * isSubSignature to an equivalence relation.
2585 *
2586 * @jls section 8.4.2.
2587 * @see #isSubSignature(Type t, Type s)
2588 * @param t a signature (possible raw, could be subjected to
2589 * erasure).
2590 * @param s a signature (possible raw, could be subjected to
2591 * erasure).
2592 * @return true if either argument is a sub signature of the other.
2593 */
2594 public boolean overrideEquivalent(Type t, Type s) {
2595 return hasSameArgs(t, s) ||
2596 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s);
2597 }
2599 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) {
2600 for (Scope.Entry e = syms.objectType.tsym.members().lookup(msym.name) ; e.scope != null ; e = e.next()) {
2601 if (msym.overrides(e.sym, origin, Types.this, true)) {
2602 return true;
2603 }
2604 }
2605 return false;
2606 }
2608 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site">
2609 class ImplementationCache {
2611 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map =
2612 new WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>>();
2614 class Entry {
2615 final MethodSymbol cachedImpl;
2616 final Filter<Symbol> implFilter;
2617 final boolean checkResult;
2618 final int prevMark;
2620 public Entry(MethodSymbol cachedImpl,
2621 Filter<Symbol> scopeFilter,
2622 boolean checkResult,
2623 int prevMark) {
2624 this.cachedImpl = cachedImpl;
2625 this.implFilter = scopeFilter;
2626 this.checkResult = checkResult;
2627 this.prevMark = prevMark;
2628 }
2630 boolean matches(Filter<Symbol> scopeFilter, boolean checkResult, int mark) {
2631 return this.implFilter == scopeFilter &&
2632 this.checkResult == checkResult &&
2633 this.prevMark == mark;
2634 }
2635 }
2637 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2638 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms);
2639 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null;
2640 if (cache == null) {
2641 cache = new HashMap<TypeSymbol, Entry>();
2642 _map.put(ms, new SoftReference<Map<TypeSymbol, Entry>>(cache));
2643 }
2644 Entry e = cache.get(origin);
2645 CompoundScope members = membersClosure(origin.type, true);
2646 if (e == null ||
2647 !e.matches(implFilter, checkResult, members.getMark())) {
2648 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter);
2649 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark()));
2650 return impl;
2651 }
2652 else {
2653 return e.cachedImpl;
2654 }
2655 }
2657 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2658 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) {
2659 while (t.hasTag(TYPEVAR))
2660 t = t.getUpperBound();
2661 TypeSymbol c = t.tsym;
2662 for (Scope.Entry e = c.members().lookup(ms.name, implFilter);
2663 e.scope != null;
2664 e = e.next(implFilter)) {
2665 if (e.sym != null &&
2666 e.sym.overrides(ms, origin, Types.this, checkResult))
2667 return (MethodSymbol)e.sym;
2668 }
2669 }
2670 return null;
2671 }
2672 }
2674 private ImplementationCache implCache = new ImplementationCache();
2676 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2677 return implCache.get(ms, origin, checkResult, implFilter);
2678 }
2679 // </editor-fold>
2681 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site">
2682 class MembersClosureCache extends SimpleVisitor<CompoundScope, Boolean> {
2684 private WeakHashMap<TypeSymbol, Entry> _map =
2685 new WeakHashMap<TypeSymbol, Entry>();
2687 class Entry {
2688 final boolean skipInterfaces;
2689 final CompoundScope compoundScope;
2691 public Entry(boolean skipInterfaces, CompoundScope compoundScope) {
2692 this.skipInterfaces = skipInterfaces;
2693 this.compoundScope = compoundScope;
2694 }
2696 boolean matches(boolean skipInterfaces) {
2697 return this.skipInterfaces == skipInterfaces;
2698 }
2699 }
2701 List<TypeSymbol> seenTypes = List.nil();
2703 /** members closure visitor methods **/
2705 public CompoundScope visitType(Type t, Boolean skipInterface) {
2706 return null;
2707 }
2709 @Override
2710 public CompoundScope visitClassType(ClassType t, Boolean skipInterface) {
2711 if (seenTypes.contains(t.tsym)) {
2712 //this is possible when an interface is implemented in multiple
2713 //superclasses, or when a classs hierarchy is circular - in such
2714 //cases we don't need to recurse (empty scope is returned)
2715 return new CompoundScope(t.tsym);
2716 }
2717 try {
2718 seenTypes = seenTypes.prepend(t.tsym);
2719 ClassSymbol csym = (ClassSymbol)t.tsym;
2720 Entry e = _map.get(csym);
2721 if (e == null || !e.matches(skipInterface)) {
2722 CompoundScope membersClosure = new CompoundScope(csym);
2723 if (!skipInterface) {
2724 for (Type i : interfaces(t)) {
2725 membersClosure.addSubScope(visit(i, skipInterface));
2726 }
2727 }
2728 membersClosure.addSubScope(visit(supertype(t), skipInterface));
2729 membersClosure.addSubScope(csym.members());
2730 e = new Entry(skipInterface, membersClosure);
2731 _map.put(csym, e);
2732 }
2733 return e.compoundScope;
2734 }
2735 finally {
2736 seenTypes = seenTypes.tail;
2737 }
2738 }
2740 @Override
2741 public CompoundScope visitTypeVar(TypeVar t, Boolean skipInterface) {
2742 return visit(t.getUpperBound(), skipInterface);
2743 }
2744 }
2746 private MembersClosureCache membersCache = new MembersClosureCache();
2748 public CompoundScope membersClosure(Type site, boolean skipInterface) {
2749 return membersCache.visit(site, skipInterface);
2750 }
2751 // </editor-fold>
2754 //where
2755 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) {
2756 Filter<Symbol> filter = new MethodFilter(ms, site);
2757 List<MethodSymbol> candidates = List.nil();
2758 for (Symbol s : membersClosure(site, false).getElements(filter)) {
2759 if (!site.tsym.isInterface() && !s.owner.isInterface()) {
2760 return List.of((MethodSymbol)s);
2761 } else if (!candidates.contains(s)) {
2762 candidates = candidates.prepend((MethodSymbol)s);
2763 }
2764 }
2765 return prune(candidates);
2766 }
2768 public List<MethodSymbol> prune(List<MethodSymbol> methods) {
2769 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>();
2770 for (MethodSymbol m1 : methods) {
2771 boolean isMin_m1 = true;
2772 for (MethodSymbol m2 : methods) {
2773 if (m1 == m2) continue;
2774 if (m2.owner != m1.owner &&
2775 asSuper(m2.owner.type, m1.owner) != null) {
2776 isMin_m1 = false;
2777 break;
2778 }
2779 }
2780 if (isMin_m1)
2781 methodsMin.append(m1);
2782 }
2783 return methodsMin.toList();
2784 }
2785 // where
2786 private class MethodFilter implements Filter<Symbol> {
2788 Symbol msym;
2789 Type site;
2791 MethodFilter(Symbol msym, Type site) {
2792 this.msym = msym;
2793 this.site = site;
2794 }
2796 public boolean accepts(Symbol s) {
2797 return s.kind == Kinds.MTH &&
2798 s.name == msym.name &&
2799 (s.flags() & SYNTHETIC) == 0 &&
2800 s.isInheritedIn(site.tsym, Types.this) &&
2801 overrideEquivalent(memberType(site, s), memberType(site, msym));
2802 }
2803 };
2804 // </editor-fold>
2806 /**
2807 * Does t have the same arguments as s? It is assumed that both
2808 * types are (possibly polymorphic) method types. Monomorphic
2809 * method types "have the same arguments", if their argument lists
2810 * are equal. Polymorphic method types "have the same arguments",
2811 * if they have the same arguments after renaming all type
2812 * variables of one to corresponding type variables in the other,
2813 * where correspondence is by position in the type parameter list.
2814 */
2815 public boolean hasSameArgs(Type t, Type s) {
2816 return hasSameArgs(t, s, true);
2817 }
2819 public boolean hasSameArgs(Type t, Type s, boolean strict) {
2820 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict);
2821 }
2823 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) {
2824 return hasSameArgs.visit(t, s);
2825 }
2826 // where
2827 private class HasSameArgs extends TypeRelation {
2829 boolean strict;
2831 public HasSameArgs(boolean strict) {
2832 this.strict = strict;
2833 }
2835 public Boolean visitType(Type t, Type s) {
2836 throw new AssertionError();
2837 }
2839 @Override
2840 public Boolean visitMethodType(MethodType t, Type s) {
2841 return s.hasTag(METHOD)
2842 && containsTypeEquivalent(t.argtypes, s.getParameterTypes());
2843 }
2845 @Override
2846 public Boolean visitForAll(ForAll t, Type s) {
2847 if (!s.hasTag(FORALL))
2848 return strict ? false : visitMethodType(t.asMethodType(), s);
2850 ForAll forAll = (ForAll)s;
2851 return hasSameBounds(t, forAll)
2852 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
2853 }
2855 @Override
2856 public Boolean visitErrorType(ErrorType t, Type s) {
2857 return false;
2858 }
2859 };
2861 TypeRelation hasSameArgs_strict = new HasSameArgs(true);
2862 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false);
2864 // </editor-fold>
2866 // <editor-fold defaultstate="collapsed" desc="subst">
2867 public List<Type> subst(List<Type> ts,
2868 List<Type> from,
2869 List<Type> to) {
2870 return new Subst(from, to).subst(ts);
2871 }
2873 /**
2874 * Substitute all occurrences of a type in `from' with the
2875 * corresponding type in `to' in 't'. Match lists `from' and `to'
2876 * from the right: If lists have different length, discard leading
2877 * elements of the longer list.
2878 */
2879 public Type subst(Type t, List<Type> from, List<Type> to) {
2880 return new Subst(from, to).subst(t);
2881 }
2883 private class Subst extends UnaryVisitor<Type> {
2884 List<Type> from;
2885 List<Type> to;
2887 public Subst(List<Type> from, List<Type> to) {
2888 int fromLength = from.length();
2889 int toLength = to.length();
2890 while (fromLength > toLength) {
2891 fromLength--;
2892 from = from.tail;
2893 }
2894 while (fromLength < toLength) {
2895 toLength--;
2896 to = to.tail;
2897 }
2898 this.from = from;
2899 this.to = to;
2900 }
2902 Type subst(Type t) {
2903 if (from.tail == null)
2904 return t;
2905 else
2906 return visit(t);
2907 }
2909 List<Type> subst(List<Type> ts) {
2910 if (from.tail == null)
2911 return ts;
2912 boolean wild = false;
2913 if (ts.nonEmpty() && from.nonEmpty()) {
2914 Type head1 = subst(ts.head);
2915 List<Type> tail1 = subst(ts.tail);
2916 if (head1 != ts.head || tail1 != ts.tail)
2917 return tail1.prepend(head1);
2918 }
2919 return ts;
2920 }
2922 public Type visitType(Type t, Void ignored) {
2923 return t;
2924 }
2926 @Override
2927 public Type visitMethodType(MethodType t, Void ignored) {
2928 List<Type> argtypes = subst(t.argtypes);
2929 Type restype = subst(t.restype);
2930 List<Type> thrown = subst(t.thrown);
2931 if (argtypes == t.argtypes &&
2932 restype == t.restype &&
2933 thrown == t.thrown)
2934 return t;
2935 else
2936 return new MethodType(argtypes, restype, thrown, t.tsym);
2937 }
2939 @Override
2940 public Type visitTypeVar(TypeVar t, Void ignored) {
2941 for (List<Type> from = this.from, to = this.to;
2942 from.nonEmpty();
2943 from = from.tail, to = to.tail) {
2944 if (t == from.head) {
2945 return to.head.withTypeVar(t);
2946 }
2947 }
2948 return t;
2949 }
2951 @Override
2952 public Type visitClassType(ClassType t, Void ignored) {
2953 if (!t.isCompound()) {
2954 List<Type> typarams = t.getTypeArguments();
2955 List<Type> typarams1 = subst(typarams);
2956 Type outer = t.getEnclosingType();
2957 Type outer1 = subst(outer);
2958 if (typarams1 == typarams && outer1 == outer)
2959 return t;
2960 else
2961 return new ClassType(outer1, typarams1, t.tsym);
2962 } else {
2963 Type st = subst(supertype(t));
2964 List<Type> is = upperBounds(subst(interfaces(t)));
2965 if (st == supertype(t) && is == interfaces(t))
2966 return t;
2967 else
2968 return makeCompoundType(is.prepend(st));
2969 }
2970 }
2972 @Override
2973 public Type visitWildcardType(WildcardType t, Void ignored) {
2974 Type bound = t.type;
2975 if (t.kind != BoundKind.UNBOUND)
2976 bound = subst(bound);
2977 if (bound == t.type) {
2978 return t;
2979 } else {
2980 if (t.isExtendsBound() && bound.isExtendsBound())
2981 bound = upperBound(bound);
2982 return new WildcardType(bound, t.kind, syms.boundClass, t.bound);
2983 }
2984 }
2986 @Override
2987 public Type visitArrayType(ArrayType t, Void ignored) {
2988 Type elemtype = subst(t.elemtype);
2989 if (elemtype == t.elemtype)
2990 return t;
2991 else
2992 return new ArrayType(elemtype, t.tsym);
2993 }
2995 @Override
2996 public Type visitForAll(ForAll t, Void ignored) {
2997 if (Type.containsAny(to, t.tvars)) {
2998 //perform alpha-renaming of free-variables in 't'
2999 //if 'to' types contain variables that are free in 't'
3000 List<Type> freevars = newInstances(t.tvars);
3001 t = new ForAll(freevars,
3002 Types.this.subst(t.qtype, t.tvars, freevars));
3003 }
3004 List<Type> tvars1 = substBounds(t.tvars, from, to);
3005 Type qtype1 = subst(t.qtype);
3006 if (tvars1 == t.tvars && qtype1 == t.qtype) {
3007 return t;
3008 } else if (tvars1 == t.tvars) {
3009 return new ForAll(tvars1, qtype1);
3010 } else {
3011 return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1));
3012 }
3013 }
3015 @Override
3016 public Type visitErrorType(ErrorType t, Void ignored) {
3017 return t;
3018 }
3019 }
3021 public List<Type> substBounds(List<Type> tvars,
3022 List<Type> from,
3023 List<Type> to) {
3024 if (tvars.isEmpty())
3025 return tvars;
3026 ListBuffer<Type> newBoundsBuf = new ListBuffer<>();
3027 boolean changed = false;
3028 // calculate new bounds
3029 for (Type t : tvars) {
3030 TypeVar tv = (TypeVar) t;
3031 Type bound = subst(tv.bound, from, to);
3032 if (bound != tv.bound)
3033 changed = true;
3034 newBoundsBuf.append(bound);
3035 }
3036 if (!changed)
3037 return tvars;
3038 ListBuffer<Type> newTvars = new ListBuffer<>();
3039 // create new type variables without bounds
3040 for (Type t : tvars) {
3041 newTvars.append(new TypeVar(t.tsym, null, syms.botType));
3042 }
3043 // the new bounds should use the new type variables in place
3044 // of the old
3045 List<Type> newBounds = newBoundsBuf.toList();
3046 from = tvars;
3047 to = newTvars.toList();
3048 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) {
3049 newBounds.head = subst(newBounds.head, from, to);
3050 }
3051 newBounds = newBoundsBuf.toList();
3052 // set the bounds of new type variables to the new bounds
3053 for (Type t : newTvars.toList()) {
3054 TypeVar tv = (TypeVar) t;
3055 tv.bound = newBounds.head;
3056 newBounds = newBounds.tail;
3057 }
3058 return newTvars.toList();
3059 }
3061 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) {
3062 Type bound1 = subst(t.bound, from, to);
3063 if (bound1 == t.bound)
3064 return t;
3065 else {
3066 // create new type variable without bounds
3067 TypeVar tv = new TypeVar(t.tsym, null, syms.botType);
3068 // the new bound should use the new type variable in place
3069 // of the old
3070 tv.bound = subst(bound1, List.<Type>of(t), List.<Type>of(tv));
3071 return tv;
3072 }
3073 }
3074 // </editor-fold>
3076 // <editor-fold defaultstate="collapsed" desc="hasSameBounds">
3077 /**
3078 * Does t have the same bounds for quantified variables as s?
3079 */
3080 public boolean hasSameBounds(ForAll t, ForAll s) {
3081 List<Type> l1 = t.tvars;
3082 List<Type> l2 = s.tvars;
3083 while (l1.nonEmpty() && l2.nonEmpty() &&
3084 isSameType(l1.head.getUpperBound(),
3085 subst(l2.head.getUpperBound(),
3086 s.tvars,
3087 t.tvars))) {
3088 l1 = l1.tail;
3089 l2 = l2.tail;
3090 }
3091 return l1.isEmpty() && l2.isEmpty();
3092 }
3093 // </editor-fold>
3095 // <editor-fold defaultstate="collapsed" desc="newInstances">
3096 /** Create new vector of type variables from list of variables
3097 * changing all recursive bounds from old to new list.
3098 */
3099 public List<Type> newInstances(List<Type> tvars) {
3100 List<Type> tvars1 = Type.map(tvars, newInstanceFun);
3101 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) {
3102 TypeVar tv = (TypeVar) l.head;
3103 tv.bound = subst(tv.bound, tvars, tvars1);
3104 }
3105 return tvars1;
3106 }
3107 private static final Mapping newInstanceFun = new Mapping("newInstanceFun") {
3108 public Type apply(Type t) { return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound()); }
3109 };
3110 // </editor-fold>
3112 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) {
3113 return original.accept(methodWithParameters, newParams);
3114 }
3115 // where
3116 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() {
3117 public Type visitType(Type t, List<Type> newParams) {
3118 throw new IllegalArgumentException("Not a method type: " + t);
3119 }
3120 public Type visitMethodType(MethodType t, List<Type> newParams) {
3121 return new MethodType(newParams, t.restype, t.thrown, t.tsym);
3122 }
3123 public Type visitForAll(ForAll t, List<Type> newParams) {
3124 return new ForAll(t.tvars, t.qtype.accept(this, newParams));
3125 }
3126 };
3128 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) {
3129 return original.accept(methodWithThrown, newThrown);
3130 }
3131 // where
3132 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() {
3133 public Type visitType(Type t, List<Type> newThrown) {
3134 throw new IllegalArgumentException("Not a method type: " + t);
3135 }
3136 public Type visitMethodType(MethodType t, List<Type> newThrown) {
3137 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym);
3138 }
3139 public Type visitForAll(ForAll t, List<Type> newThrown) {
3140 return new ForAll(t.tvars, t.qtype.accept(this, newThrown));
3141 }
3142 };
3144 public Type createMethodTypeWithReturn(Type original, Type newReturn) {
3145 return original.accept(methodWithReturn, newReturn);
3146 }
3147 // where
3148 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() {
3149 public Type visitType(Type t, Type newReturn) {
3150 throw new IllegalArgumentException("Not a method type: " + t);
3151 }
3152 public Type visitMethodType(MethodType t, Type newReturn) {
3153 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym);
3154 }
3155 public Type visitForAll(ForAll t, Type newReturn) {
3156 return new ForAll(t.tvars, t.qtype.accept(this, newReturn));
3157 }
3158 };
3160 // <editor-fold defaultstate="collapsed" desc="createErrorType">
3161 public Type createErrorType(Type originalType) {
3162 return new ErrorType(originalType, syms.errSymbol);
3163 }
3165 public Type createErrorType(ClassSymbol c, Type originalType) {
3166 return new ErrorType(c, originalType);
3167 }
3169 public Type createErrorType(Name name, TypeSymbol container, Type originalType) {
3170 return new ErrorType(name, container, originalType);
3171 }
3172 // </editor-fold>
3174 // <editor-fold defaultstate="collapsed" desc="rank">
3175 /**
3176 * The rank of a class is the length of the longest path between
3177 * the class and java.lang.Object in the class inheritance
3178 * graph. Undefined for all but reference types.
3179 */
3180 public int rank(Type t) {
3181 t = t.unannotatedType();
3182 switch(t.getTag()) {
3183 case CLASS: {
3184 ClassType cls = (ClassType)t;
3185 if (cls.rank_field < 0) {
3186 Name fullname = cls.tsym.getQualifiedName();
3187 if (fullname == names.java_lang_Object)
3188 cls.rank_field = 0;
3189 else {
3190 int r = rank(supertype(cls));
3191 for (List<Type> l = interfaces(cls);
3192 l.nonEmpty();
3193 l = l.tail) {
3194 if (rank(l.head) > r)
3195 r = rank(l.head);
3196 }
3197 cls.rank_field = r + 1;
3198 }
3199 }
3200 return cls.rank_field;
3201 }
3202 case TYPEVAR: {
3203 TypeVar tvar = (TypeVar)t;
3204 if (tvar.rank_field < 0) {
3205 int r = rank(supertype(tvar));
3206 for (List<Type> l = interfaces(tvar);
3207 l.nonEmpty();
3208 l = l.tail) {
3209 if (rank(l.head) > r) r = rank(l.head);
3210 }
3211 tvar.rank_field = r + 1;
3212 }
3213 return tvar.rank_field;
3214 }
3215 case ERROR:
3216 return 0;
3217 default:
3218 throw new AssertionError();
3219 }
3220 }
3221 // </editor-fold>
3223 /**
3224 * Helper method for generating a string representation of a given type
3225 * accordingly to a given locale
3226 */
3227 public String toString(Type t, Locale locale) {
3228 return Printer.createStandardPrinter(messages).visit(t, locale);
3229 }
3231 /**
3232 * Helper method for generating a string representation of a given type
3233 * accordingly to a given locale
3234 */
3235 public String toString(Symbol t, Locale locale) {
3236 return Printer.createStandardPrinter(messages).visit(t, locale);
3237 }
3239 // <editor-fold defaultstate="collapsed" desc="toString">
3240 /**
3241 * This toString is slightly more descriptive than the one on Type.
3242 *
3243 * @deprecated Types.toString(Type t, Locale l) provides better support
3244 * for localization
3245 */
3246 @Deprecated
3247 public String toString(Type t) {
3248 if (t.hasTag(FORALL)) {
3249 ForAll forAll = (ForAll)t;
3250 return typaramsString(forAll.tvars) + forAll.qtype;
3251 }
3252 return "" + t;
3253 }
3254 // where
3255 private String typaramsString(List<Type> tvars) {
3256 StringBuilder s = new StringBuilder();
3257 s.append('<');
3258 boolean first = true;
3259 for (Type t : tvars) {
3260 if (!first) s.append(", ");
3261 first = false;
3262 appendTyparamString(((TypeVar)t.unannotatedType()), s);
3263 }
3264 s.append('>');
3265 return s.toString();
3266 }
3267 private void appendTyparamString(TypeVar t, StringBuilder buf) {
3268 buf.append(t);
3269 if (t.bound == null ||
3270 t.bound.tsym.getQualifiedName() == names.java_lang_Object)
3271 return;
3272 buf.append(" extends "); // Java syntax; no need for i18n
3273 Type bound = t.bound;
3274 if (!bound.isCompound()) {
3275 buf.append(bound);
3276 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) {
3277 buf.append(supertype(t));
3278 for (Type intf : interfaces(t)) {
3279 buf.append('&');
3280 buf.append(intf);
3281 }
3282 } else {
3283 // No superclass was given in bounds.
3284 // In this case, supertype is Object, erasure is first interface.
3285 boolean first = true;
3286 for (Type intf : interfaces(t)) {
3287 if (!first) buf.append('&');
3288 first = false;
3289 buf.append(intf);
3290 }
3291 }
3292 }
3293 // </editor-fold>
3295 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types">
3296 /**
3297 * A cache for closures.
3298 *
3299 * <p>A closure is a list of all the supertypes and interfaces of
3300 * a class or interface type, ordered by ClassSymbol.precedes
3301 * (that is, subclasses come first, arbitrary but fixed
3302 * otherwise).
3303 */
3304 private Map<Type,List<Type>> closureCache = new HashMap<Type,List<Type>>();
3306 /**
3307 * Returns the closure of a class or interface type.
3308 */
3309 public List<Type> closure(Type t) {
3310 List<Type> cl = closureCache.get(t);
3311 if (cl == null) {
3312 Type st = supertype(t);
3313 if (!t.isCompound()) {
3314 if (st.hasTag(CLASS)) {
3315 cl = insert(closure(st), t);
3316 } else if (st.hasTag(TYPEVAR)) {
3317 cl = closure(st).prepend(t);
3318 } else {
3319 cl = List.of(t);
3320 }
3321 } else {
3322 cl = closure(supertype(t));
3323 }
3324 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail)
3325 cl = union(cl, closure(l.head));
3326 closureCache.put(t, cl);
3327 }
3328 return cl;
3329 }
3331 /**
3332 * Insert a type in a closure
3333 */
3334 public List<Type> insert(List<Type> cl, Type t) {
3335 if (cl.isEmpty() || t.tsym.precedes(cl.head.tsym, this)) {
3336 return cl.prepend(t);
3337 } else if (cl.head.tsym.precedes(t.tsym, this)) {
3338 return insert(cl.tail, t).prepend(cl.head);
3339 } else {
3340 return cl;
3341 }
3342 }
3344 /**
3345 * Form the union of two closures
3346 */
3347 public List<Type> union(List<Type> cl1, List<Type> cl2) {
3348 if (cl1.isEmpty()) {
3349 return cl2;
3350 } else if (cl2.isEmpty()) {
3351 return cl1;
3352 } else if (cl1.head.tsym.precedes(cl2.head.tsym, this)) {
3353 return union(cl1.tail, cl2).prepend(cl1.head);
3354 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) {
3355 return union(cl1, cl2.tail).prepend(cl2.head);
3356 } else {
3357 return union(cl1.tail, cl2.tail).prepend(cl1.head);
3358 }
3359 }
3361 /**
3362 * Intersect two closures
3363 */
3364 public List<Type> intersect(List<Type> cl1, List<Type> cl2) {
3365 if (cl1 == cl2)
3366 return cl1;
3367 if (cl1.isEmpty() || cl2.isEmpty())
3368 return List.nil();
3369 if (cl1.head.tsym.precedes(cl2.head.tsym, this))
3370 return intersect(cl1.tail, cl2);
3371 if (cl2.head.tsym.precedes(cl1.head.tsym, this))
3372 return intersect(cl1, cl2.tail);
3373 if (isSameType(cl1.head, cl2.head))
3374 return intersect(cl1.tail, cl2.tail).prepend(cl1.head);
3375 if (cl1.head.tsym == cl2.head.tsym &&
3376 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) {
3377 if (cl1.head.isParameterized() && cl2.head.isParameterized()) {
3378 Type merge = merge(cl1.head,cl2.head);
3379 return intersect(cl1.tail, cl2.tail).prepend(merge);
3380 }
3381 if (cl1.head.isRaw() || cl2.head.isRaw())
3382 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head));
3383 }
3384 return intersect(cl1.tail, cl2.tail);
3385 }
3386 // where
3387 class TypePair {
3388 final Type t1;
3389 final Type t2;
3390 TypePair(Type t1, Type t2) {
3391 this.t1 = t1;
3392 this.t2 = t2;
3393 }
3394 @Override
3395 public int hashCode() {
3396 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2);
3397 }
3398 @Override
3399 public boolean equals(Object obj) {
3400 if (!(obj instanceof TypePair))
3401 return false;
3402 TypePair typePair = (TypePair)obj;
3403 return isSameType(t1, typePair.t1)
3404 && isSameType(t2, typePair.t2);
3405 }
3406 }
3407 Set<TypePair> mergeCache = new HashSet<TypePair>();
3408 private Type merge(Type c1, Type c2) {
3409 ClassType class1 = (ClassType) c1;
3410 List<Type> act1 = class1.getTypeArguments();
3411 ClassType class2 = (ClassType) c2;
3412 List<Type> act2 = class2.getTypeArguments();
3413 ListBuffer<Type> merged = new ListBuffer<Type>();
3414 List<Type> typarams = class1.tsym.type.getTypeArguments();
3416 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) {
3417 if (containsType(act1.head, act2.head)) {
3418 merged.append(act1.head);
3419 } else if (containsType(act2.head, act1.head)) {
3420 merged.append(act2.head);
3421 } else {
3422 TypePair pair = new TypePair(c1, c2);
3423 Type m;
3424 if (mergeCache.add(pair)) {
3425 m = new WildcardType(lub(upperBound(act1.head),
3426 upperBound(act2.head)),
3427 BoundKind.EXTENDS,
3428 syms.boundClass);
3429 mergeCache.remove(pair);
3430 } else {
3431 m = new WildcardType(syms.objectType,
3432 BoundKind.UNBOUND,
3433 syms.boundClass);
3434 }
3435 merged.append(m.withTypeVar(typarams.head));
3436 }
3437 act1 = act1.tail;
3438 act2 = act2.tail;
3439 typarams = typarams.tail;
3440 }
3441 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty());
3442 return new ClassType(class1.getEnclosingType(), merged.toList(), class1.tsym);
3443 }
3445 /**
3446 * Return the minimum type of a closure, a compound type if no
3447 * unique minimum exists.
3448 */
3449 private Type compoundMin(List<Type> cl) {
3450 if (cl.isEmpty()) return syms.objectType;
3451 List<Type> compound = closureMin(cl);
3452 if (compound.isEmpty())
3453 return null;
3454 else if (compound.tail.isEmpty())
3455 return compound.head;
3456 else
3457 return makeCompoundType(compound);
3458 }
3460 /**
3461 * Return the minimum types of a closure, suitable for computing
3462 * compoundMin or glb.
3463 */
3464 private List<Type> closureMin(List<Type> cl) {
3465 ListBuffer<Type> classes = new ListBuffer<>();
3466 ListBuffer<Type> interfaces = new ListBuffer<>();
3467 while (!cl.isEmpty()) {
3468 Type current = cl.head;
3469 if (current.isInterface())
3470 interfaces.append(current);
3471 else
3472 classes.append(current);
3473 ListBuffer<Type> candidates = new ListBuffer<>();
3474 for (Type t : cl.tail) {
3475 if (!isSubtypeNoCapture(current, t))
3476 candidates.append(t);
3477 }
3478 cl = candidates.toList();
3479 }
3480 return classes.appendList(interfaces).toList();
3481 }
3483 /**
3484 * Return the least upper bound of pair of types. if the lub does
3485 * not exist return null.
3486 */
3487 public Type lub(Type t1, Type t2) {
3488 return lub(List.of(t1, t2));
3489 }
3491 /**
3492 * Return the least upper bound (lub) of set of types. If the lub
3493 * does not exist return the type of null (bottom).
3494 */
3495 public Type lub(List<Type> ts) {
3496 final int ARRAY_BOUND = 1;
3497 final int CLASS_BOUND = 2;
3498 int boundkind = 0;
3499 for (Type t : ts) {
3500 switch (t.getTag()) {
3501 case CLASS:
3502 boundkind |= CLASS_BOUND;
3503 break;
3504 case ARRAY:
3505 boundkind |= ARRAY_BOUND;
3506 break;
3507 case TYPEVAR:
3508 do {
3509 t = t.getUpperBound();
3510 } while (t.hasTag(TYPEVAR));
3511 if (t.hasTag(ARRAY)) {
3512 boundkind |= ARRAY_BOUND;
3513 } else {
3514 boundkind |= CLASS_BOUND;
3515 }
3516 break;
3517 default:
3518 if (t.isPrimitive())
3519 return syms.errType;
3520 }
3521 }
3522 switch (boundkind) {
3523 case 0:
3524 return syms.botType;
3526 case ARRAY_BOUND:
3527 // calculate lub(A[], B[])
3528 List<Type> elements = Type.map(ts, elemTypeFun);
3529 for (Type t : elements) {
3530 if (t.isPrimitive()) {
3531 // if a primitive type is found, then return
3532 // arraySuperType unless all the types are the
3533 // same
3534 Type first = ts.head;
3535 for (Type s : ts.tail) {
3536 if (!isSameType(first, s)) {
3537 // lub(int[], B[]) is Cloneable & Serializable
3538 return arraySuperType();
3539 }
3540 }
3541 // all the array types are the same, return one
3542 // lub(int[], int[]) is int[]
3543 return first;
3544 }
3545 }
3546 // lub(A[], B[]) is lub(A, B)[]
3547 return new ArrayType(lub(elements), syms.arrayClass);
3549 case CLASS_BOUND:
3550 // calculate lub(A, B)
3551 while (!ts.head.hasTag(CLASS) && !ts.head.hasTag(TYPEVAR)) {
3552 ts = ts.tail;
3553 }
3554 Assert.check(!ts.isEmpty());
3555 //step 1 - compute erased candidate set (EC)
3556 List<Type> cl = erasedSupertypes(ts.head);
3557 for (Type t : ts.tail) {
3558 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR))
3559 cl = intersect(cl, erasedSupertypes(t));
3560 }
3561 //step 2 - compute minimal erased candidate set (MEC)
3562 List<Type> mec = closureMin(cl);
3563 //step 3 - for each element G in MEC, compute lci(Inv(G))
3564 List<Type> candidates = List.nil();
3565 for (Type erasedSupertype : mec) {
3566 List<Type> lci = List.of(asSuper(ts.head, erasedSupertype.tsym));
3567 for (Type t : ts) {
3568 lci = intersect(lci, List.of(asSuper(t, erasedSupertype.tsym)));
3569 }
3570 candidates = candidates.appendList(lci);
3571 }
3572 //step 4 - let MEC be { G1, G2 ... Gn }, then we have that
3573 //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn))
3574 return compoundMin(candidates);
3576 default:
3577 // calculate lub(A, B[])
3578 List<Type> classes = List.of(arraySuperType());
3579 for (Type t : ts) {
3580 if (!t.hasTag(ARRAY)) // Filter out any arrays
3581 classes = classes.prepend(t);
3582 }
3583 // lub(A, B[]) is lub(A, arraySuperType)
3584 return lub(classes);
3585 }
3586 }
3587 // where
3588 List<Type> erasedSupertypes(Type t) {
3589 ListBuffer<Type> buf = new ListBuffer<>();
3590 for (Type sup : closure(t)) {
3591 if (sup.hasTag(TYPEVAR)) {
3592 buf.append(sup);
3593 } else {
3594 buf.append(erasure(sup));
3595 }
3596 }
3597 return buf.toList();
3598 }
3600 private Type arraySuperType = null;
3601 private Type arraySuperType() {
3602 // initialized lazily to avoid problems during compiler startup
3603 if (arraySuperType == null) {
3604 synchronized (this) {
3605 if (arraySuperType == null) {
3606 // JLS 10.8: all arrays implement Cloneable and Serializable.
3607 arraySuperType = makeCompoundType(List.of(syms.serializableType,
3608 syms.cloneableType), true);
3609 }
3610 }
3611 }
3612 return arraySuperType;
3613 }
3614 // </editor-fold>
3616 // <editor-fold defaultstate="collapsed" desc="Greatest lower bound">
3617 public Type glb(List<Type> ts) {
3618 Type t1 = ts.head;
3619 for (Type t2 : ts.tail) {
3620 if (t1.isErroneous())
3621 return t1;
3622 t1 = glb(t1, t2);
3623 }
3624 return t1;
3625 }
3626 //where
3627 public Type glb(Type t, Type s) {
3628 if (s == null)
3629 return t;
3630 else if (t.isPrimitive() || s.isPrimitive())
3631 return syms.errType;
3632 else if (isSubtypeNoCapture(t, s))
3633 return t;
3634 else if (isSubtypeNoCapture(s, t))
3635 return s;
3637 List<Type> closure = union(closure(t), closure(s));
3638 List<Type> bounds = closureMin(closure);
3640 if (bounds.isEmpty()) { // length == 0
3641 return syms.objectType;
3642 } else if (bounds.tail.isEmpty()) { // length == 1
3643 return bounds.head;
3644 } else { // length > 1
3645 int classCount = 0;
3646 for (Type bound : bounds)
3647 if (!bound.isInterface())
3648 classCount++;
3649 if (classCount > 1)
3650 return createErrorType(t);
3651 }
3652 return makeCompoundType(bounds);
3653 }
3654 // </editor-fold>
3656 // <editor-fold defaultstate="collapsed" desc="hashCode">
3657 /**
3658 * Compute a hash code on a type.
3659 */
3660 public int hashCode(Type t) {
3661 return hashCode.visit(t);
3662 }
3663 // where
3664 private static final UnaryVisitor<Integer> hashCode = new UnaryVisitor<Integer>() {
3666 public Integer visitType(Type t, Void ignored) {
3667 return t.getTag().ordinal();
3668 }
3670 @Override
3671 public Integer visitClassType(ClassType t, Void ignored) {
3672 int result = visit(t.getEnclosingType());
3673 result *= 127;
3674 result += t.tsym.flatName().hashCode();
3675 for (Type s : t.getTypeArguments()) {
3676 result *= 127;
3677 result += visit(s);
3678 }
3679 return result;
3680 }
3682 @Override
3683 public Integer visitMethodType(MethodType t, Void ignored) {
3684 int h = METHOD.ordinal();
3685 for (List<Type> thisargs = t.argtypes;
3686 thisargs.tail != null;
3687 thisargs = thisargs.tail)
3688 h = (h << 5) + visit(thisargs.head);
3689 return (h << 5) + visit(t.restype);
3690 }
3692 @Override
3693 public Integer visitWildcardType(WildcardType t, Void ignored) {
3694 int result = t.kind.hashCode();
3695 if (t.type != null) {
3696 result *= 127;
3697 result += visit(t.type);
3698 }
3699 return result;
3700 }
3702 @Override
3703 public Integer visitArrayType(ArrayType t, Void ignored) {
3704 return visit(t.elemtype) + 12;
3705 }
3707 @Override
3708 public Integer visitTypeVar(TypeVar t, Void ignored) {
3709 return System.identityHashCode(t.tsym);
3710 }
3712 @Override
3713 public Integer visitUndetVar(UndetVar t, Void ignored) {
3714 return System.identityHashCode(t);
3715 }
3717 @Override
3718 public Integer visitErrorType(ErrorType t, Void ignored) {
3719 return 0;
3720 }
3721 };
3722 // </editor-fold>
3724 // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable">
3725 /**
3726 * Does t have a result that is a subtype of the result type of s,
3727 * suitable for covariant returns? It is assumed that both types
3728 * are (possibly polymorphic) method types. Monomorphic method
3729 * types are handled in the obvious way. Polymorphic method types
3730 * require renaming all type variables of one to corresponding
3731 * type variables in the other, where correspondence is by
3732 * position in the type parameter list. */
3733 public boolean resultSubtype(Type t, Type s, Warner warner) {
3734 List<Type> tvars = t.getTypeArguments();
3735 List<Type> svars = s.getTypeArguments();
3736 Type tres = t.getReturnType();
3737 Type sres = subst(s.getReturnType(), svars, tvars);
3738 return covariantReturnType(tres, sres, warner);
3739 }
3741 /**
3742 * Return-Type-Substitutable.
3743 * @jls section 8.4.5
3744 */
3745 public boolean returnTypeSubstitutable(Type r1, Type r2) {
3746 if (hasSameArgs(r1, r2))
3747 return resultSubtype(r1, r2, noWarnings);
3748 else
3749 return covariantReturnType(r1.getReturnType(),
3750 erasure(r2.getReturnType()),
3751 noWarnings);
3752 }
3754 public boolean returnTypeSubstitutable(Type r1,
3755 Type r2, Type r2res,
3756 Warner warner) {
3757 if (isSameType(r1.getReturnType(), r2res))
3758 return true;
3759 if (r1.getReturnType().isPrimitive() || r2res.isPrimitive())
3760 return false;
3762 if (hasSameArgs(r1, r2))
3763 return covariantReturnType(r1.getReturnType(), r2res, warner);
3764 if (!allowCovariantReturns)
3765 return false;
3766 if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner))
3767 return true;
3768 if (!isSubtype(r1.getReturnType(), erasure(r2res)))
3769 return false;
3770 warner.warn(LintCategory.UNCHECKED);
3771 return true;
3772 }
3774 /**
3775 * Is t an appropriate return type in an overrider for a
3776 * method that returns s?
3777 */
3778 public boolean covariantReturnType(Type t, Type s, Warner warner) {
3779 return
3780 isSameType(t, s) ||
3781 allowCovariantReturns &&
3782 !t.isPrimitive() &&
3783 !s.isPrimitive() &&
3784 isAssignable(t, s, warner);
3785 }
3786 // </editor-fold>
3788 // <editor-fold defaultstate="collapsed" desc="Box/unbox support">
3789 /**
3790 * Return the class that boxes the given primitive.
3791 */
3792 public ClassSymbol boxedClass(Type t) {
3793 return reader.enterClass(syms.boxedName[t.getTag().ordinal()]);
3794 }
3796 /**
3797 * Return the boxed type if 't' is primitive, otherwise return 't' itself.
3798 */
3799 public Type boxedTypeOrType(Type t) {
3800 return t.isPrimitive() ?
3801 boxedClass(t).type :
3802 t;
3803 }
3805 /**
3806 * Return the primitive type corresponding to a boxed type.
3807 */
3808 public Type unboxedType(Type t) {
3809 if (allowBoxing) {
3810 for (int i=0; i<syms.boxedName.length; i++) {
3811 Name box = syms.boxedName[i];
3812 if (box != null &&
3813 asSuper(t, reader.enterClass(box)) != null)
3814 return syms.typeOfTag[i];
3815 }
3816 }
3817 return Type.noType;
3818 }
3820 /**
3821 * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself.
3822 */
3823 public Type unboxedTypeOrType(Type t) {
3824 Type unboxedType = unboxedType(t);
3825 return unboxedType.hasTag(NONE) ? t : unboxedType;
3826 }
3827 // </editor-fold>
3829 // <editor-fold defaultstate="collapsed" desc="Capture conversion">
3830 /*
3831 * JLS 5.1.10 Capture Conversion:
3832 *
3833 * Let G name a generic type declaration with n formal type
3834 * parameters A1 ... An with corresponding bounds U1 ... Un. There
3835 * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>,
3836 * where, for 1 <= i <= n:
3837 *
3838 * + If Ti is a wildcard type argument (4.5.1) of the form ? then
3839 * Si is a fresh type variable whose upper bound is
3840 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null
3841 * type.
3842 *
3843 * + If Ti is a wildcard type argument of the form ? extends Bi,
3844 * then Si is a fresh type variable whose upper bound is
3845 * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is
3846 * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is
3847 * a compile-time error if for any two classes (not interfaces)
3848 * Vi and Vj,Vi is not a subclass of Vj or vice versa.
3849 *
3850 * + If Ti is a wildcard type argument of the form ? super Bi,
3851 * then Si is a fresh type variable whose upper bound is
3852 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi.
3853 *
3854 * + Otherwise, Si = Ti.
3855 *
3856 * Capture conversion on any type other than a parameterized type
3857 * (4.5) acts as an identity conversion (5.1.1). Capture
3858 * conversions never require a special action at run time and
3859 * therefore never throw an exception at run time.
3860 *
3861 * Capture conversion is not applied recursively.
3862 */
3863 /**
3864 * Capture conversion as specified by the JLS.
3865 */
3867 public List<Type> capture(List<Type> ts) {
3868 List<Type> buf = List.nil();
3869 for (Type t : ts) {
3870 buf = buf.prepend(capture(t));
3871 }
3872 return buf.reverse();
3873 }
3874 public Type capture(Type t) {
3875 if (!t.hasTag(CLASS))
3876 return t;
3877 if (t.getEnclosingType() != Type.noType) {
3878 Type capturedEncl = capture(t.getEnclosingType());
3879 if (capturedEncl != t.getEnclosingType()) {
3880 Type type1 = memberType(capturedEncl, t.tsym);
3881 t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments());
3882 }
3883 }
3884 t = t.unannotatedType();
3885 ClassType cls = (ClassType)t;
3886 if (cls.isRaw() || !cls.isParameterized())
3887 return cls;
3889 ClassType G = (ClassType)cls.asElement().asType();
3890 List<Type> A = G.getTypeArguments();
3891 List<Type> T = cls.getTypeArguments();
3892 List<Type> S = freshTypeVariables(T);
3894 List<Type> currentA = A;
3895 List<Type> currentT = T;
3896 List<Type> currentS = S;
3897 boolean captured = false;
3898 while (!currentA.isEmpty() &&
3899 !currentT.isEmpty() &&
3900 !currentS.isEmpty()) {
3901 if (currentS.head != currentT.head) {
3902 captured = true;
3903 WildcardType Ti = (WildcardType)currentT.head.unannotatedType();
3904 Type Ui = currentA.head.getUpperBound();
3905 CapturedType Si = (CapturedType)currentS.head.unannotatedType();
3906 if (Ui == null)
3907 Ui = syms.objectType;
3908 switch (Ti.kind) {
3909 case UNBOUND:
3910 Si.bound = subst(Ui, A, S);
3911 Si.lower = syms.botType;
3912 break;
3913 case EXTENDS:
3914 Si.bound = glb(Ti.getExtendsBound(), subst(Ui, A, S));
3915 Si.lower = syms.botType;
3916 break;
3917 case SUPER:
3918 Si.bound = subst(Ui, A, S);
3919 Si.lower = Ti.getSuperBound();
3920 break;
3921 }
3922 if (Si.bound == Si.lower)
3923 currentS.head = Si.bound;
3924 }
3925 currentA = currentA.tail;
3926 currentT = currentT.tail;
3927 currentS = currentS.tail;
3928 }
3929 if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty())
3930 return erasure(t); // some "rare" type involved
3932 if (captured)
3933 return new ClassType(cls.getEnclosingType(), S, cls.tsym);
3934 else
3935 return t;
3936 }
3937 // where
3938 public List<Type> freshTypeVariables(List<Type> types) {
3939 ListBuffer<Type> result = new ListBuffer<>();
3940 for (Type t : types) {
3941 if (t.hasTag(WILDCARD)) {
3942 t = t.unannotatedType();
3943 Type bound = ((WildcardType)t).getExtendsBound();
3944 if (bound == null)
3945 bound = syms.objectType;
3946 result.append(new CapturedType(capturedName,
3947 syms.noSymbol,
3948 bound,
3949 syms.botType,
3950 (WildcardType)t));
3951 } else {
3952 result.append(t);
3953 }
3954 }
3955 return result.toList();
3956 }
3957 // </editor-fold>
3959 // <editor-fold defaultstate="collapsed" desc="Internal utility methods">
3960 private List<Type> upperBounds(List<Type> ss) {
3961 if (ss.isEmpty()) return ss;
3962 Type head = upperBound(ss.head);
3963 List<Type> tail = upperBounds(ss.tail);
3964 if (head != ss.head || tail != ss.tail)
3965 return tail.prepend(head);
3966 else
3967 return ss;
3968 }
3970 private boolean sideCast(Type from, Type to, Warner warn) {
3971 // We are casting from type $from$ to type $to$, which are
3972 // non-final unrelated types. This method
3973 // tries to reject a cast by transferring type parameters
3974 // from $to$ to $from$ by common superinterfaces.
3975 boolean reverse = false;
3976 Type target = to;
3977 if ((to.tsym.flags() & INTERFACE) == 0) {
3978 Assert.check((from.tsym.flags() & INTERFACE) != 0);
3979 reverse = true;
3980 to = from;
3981 from = target;
3982 }
3983 List<Type> commonSupers = superClosure(to, erasure(from));
3984 boolean giveWarning = commonSupers.isEmpty();
3985 // The arguments to the supers could be unified here to
3986 // get a more accurate analysis
3987 while (commonSupers.nonEmpty()) {
3988 Type t1 = asSuper(from, commonSupers.head.tsym);
3989 Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym);
3990 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
3991 return false;
3992 giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2));
3993 commonSupers = commonSupers.tail;
3994 }
3995 if (giveWarning && !isReifiable(reverse ? from : to))
3996 warn.warn(LintCategory.UNCHECKED);
3997 if (!allowCovariantReturns)
3998 // reject if there is a common method signature with
3999 // incompatible return types.
4000 chk.checkCompatibleAbstracts(warn.pos(), from, to);
4001 return true;
4002 }
4004 private boolean sideCastFinal(Type from, Type to, Warner warn) {
4005 // We are casting from type $from$ to type $to$, which are
4006 // unrelated types one of which is final and the other of
4007 // which is an interface. This method
4008 // tries to reject a cast by transferring type parameters
4009 // from the final class to the interface.
4010 boolean reverse = false;
4011 Type target = to;
4012 if ((to.tsym.flags() & INTERFACE) == 0) {
4013 Assert.check((from.tsym.flags() & INTERFACE) != 0);
4014 reverse = true;
4015 to = from;
4016 from = target;
4017 }
4018 Assert.check((from.tsym.flags() & FINAL) != 0);
4019 Type t1 = asSuper(from, to.tsym);
4020 if (t1 == null) return false;
4021 Type t2 = to;
4022 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4023 return false;
4024 if (!allowCovariantReturns)
4025 // reject if there is a common method signature with
4026 // incompatible return types.
4027 chk.checkCompatibleAbstracts(warn.pos(), from, to);
4028 if (!isReifiable(target) &&
4029 (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)))
4030 warn.warn(LintCategory.UNCHECKED);
4031 return true;
4032 }
4034 private boolean giveWarning(Type from, Type to) {
4035 List<Type> bounds = to.isCompound() ?
4036 ((IntersectionClassType)to.unannotatedType()).getComponents() : List.of(to);
4037 for (Type b : bounds) {
4038 Type subFrom = asSub(from, b.tsym);
4039 if (b.isParameterized() &&
4040 (!(isUnbounded(b) ||
4041 isSubtype(from, b) ||
4042 ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) {
4043 return true;
4044 }
4045 }
4046 return false;
4047 }
4049 private List<Type> superClosure(Type t, Type s) {
4050 List<Type> cl = List.nil();
4051 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
4052 if (isSubtype(s, erasure(l.head))) {
4053 cl = insert(cl, l.head);
4054 } else {
4055 cl = union(cl, superClosure(l.head, s));
4056 }
4057 }
4058 return cl;
4059 }
4061 private boolean containsTypeEquivalent(Type t, Type s) {
4062 return
4063 isSameType(t, s) || // shortcut
4064 containsType(t, s) && containsType(s, t);
4065 }
4067 // <editor-fold defaultstate="collapsed" desc="adapt">
4068 /**
4069 * Adapt a type by computing a substitution which maps a source
4070 * type to a target type.
4071 *
4072 * @param source the source type
4073 * @param target the target type
4074 * @param from the type variables of the computed substitution
4075 * @param to the types of the computed substitution.
4076 */
4077 public void adapt(Type source,
4078 Type target,
4079 ListBuffer<Type> from,
4080 ListBuffer<Type> to) throws AdaptFailure {
4081 new Adapter(from, to).adapt(source, target);
4082 }
4084 class Adapter extends SimpleVisitor<Void, Type> {
4086 ListBuffer<Type> from;
4087 ListBuffer<Type> to;
4088 Map<Symbol,Type> mapping;
4090 Adapter(ListBuffer<Type> from, ListBuffer<Type> to) {
4091 this.from = from;
4092 this.to = to;
4093 mapping = new HashMap<Symbol,Type>();
4094 }
4096 public void adapt(Type source, Type target) throws AdaptFailure {
4097 visit(source, target);
4098 List<Type> fromList = from.toList();
4099 List<Type> toList = to.toList();
4100 while (!fromList.isEmpty()) {
4101 Type val = mapping.get(fromList.head.tsym);
4102 if (toList.head != val)
4103 toList.head = val;
4104 fromList = fromList.tail;
4105 toList = toList.tail;
4106 }
4107 }
4109 @Override
4110 public Void visitClassType(ClassType source, Type target) throws AdaptFailure {
4111 if (target.hasTag(CLASS))
4112 adaptRecursive(source.allparams(), target.allparams());
4113 return null;
4114 }
4116 @Override
4117 public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure {
4118 if (target.hasTag(ARRAY))
4119 adaptRecursive(elemtype(source), elemtype(target));
4120 return null;
4121 }
4123 @Override
4124 public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure {
4125 if (source.isExtendsBound())
4126 adaptRecursive(upperBound(source), upperBound(target));
4127 else if (source.isSuperBound())
4128 adaptRecursive(lowerBound(source), lowerBound(target));
4129 return null;
4130 }
4132 @Override
4133 public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure {
4134 // Check to see if there is
4135 // already a mapping for $source$, in which case
4136 // the old mapping will be merged with the new
4137 Type val = mapping.get(source.tsym);
4138 if (val != null) {
4139 if (val.isSuperBound() && target.isSuperBound()) {
4140 val = isSubtype(lowerBound(val), lowerBound(target))
4141 ? target : val;
4142 } else if (val.isExtendsBound() && target.isExtendsBound()) {
4143 val = isSubtype(upperBound(val), upperBound(target))
4144 ? val : target;
4145 } else if (!isSameType(val, target)) {
4146 throw new AdaptFailure();
4147 }
4148 } else {
4149 val = target;
4150 from.append(source);
4151 to.append(target);
4152 }
4153 mapping.put(source.tsym, val);
4154 return null;
4155 }
4157 @Override
4158 public Void visitType(Type source, Type target) {
4159 return null;
4160 }
4162 private Set<TypePair> cache = new HashSet<TypePair>();
4164 private void adaptRecursive(Type source, Type target) {
4165 TypePair pair = new TypePair(source, target);
4166 if (cache.add(pair)) {
4167 try {
4168 visit(source, target);
4169 } finally {
4170 cache.remove(pair);
4171 }
4172 }
4173 }
4175 private void adaptRecursive(List<Type> source, List<Type> target) {
4176 if (source.length() == target.length()) {
4177 while (source.nonEmpty()) {
4178 adaptRecursive(source.head, target.head);
4179 source = source.tail;
4180 target = target.tail;
4181 }
4182 }
4183 }
4184 }
4186 public static class AdaptFailure extends RuntimeException {
4187 static final long serialVersionUID = -7490231548272701566L;
4188 }
4190 private void adaptSelf(Type t,
4191 ListBuffer<Type> from,
4192 ListBuffer<Type> to) {
4193 try {
4194 //if (t.tsym.type != t)
4195 adapt(t.tsym.type, t, from, to);
4196 } catch (AdaptFailure ex) {
4197 // Adapt should never fail calculating a mapping from
4198 // t.tsym.type to t as there can be no merge problem.
4199 throw new AssertionError(ex);
4200 }
4201 }
4202 // </editor-fold>
4204 /**
4205 * Rewrite all type variables (universal quantifiers) in the given
4206 * type to wildcards (existential quantifiers). This is used to
4207 * determine if a cast is allowed. For example, if high is true
4208 * and {@code T <: Number}, then {@code List<T>} is rewritten to
4209 * {@code List<? extends Number>}. Since {@code List<Integer> <:
4210 * List<? extends Number>} a {@code List<T>} can be cast to {@code
4211 * List<Integer>} with a warning.
4212 * @param t a type
4213 * @param high if true return an upper bound; otherwise a lower
4214 * bound
4215 * @param rewriteTypeVars only rewrite captured wildcards if false;
4216 * otherwise rewrite all type variables
4217 * @return the type rewritten with wildcards (existential
4218 * quantifiers) only
4219 */
4220 private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) {
4221 return new Rewriter(high, rewriteTypeVars).visit(t);
4222 }
4224 class Rewriter extends UnaryVisitor<Type> {
4226 boolean high;
4227 boolean rewriteTypeVars;
4229 Rewriter(boolean high, boolean rewriteTypeVars) {
4230 this.high = high;
4231 this.rewriteTypeVars = rewriteTypeVars;
4232 }
4234 @Override
4235 public Type visitClassType(ClassType t, Void s) {
4236 ListBuffer<Type> rewritten = new ListBuffer<Type>();
4237 boolean changed = false;
4238 for (Type arg : t.allparams()) {
4239 Type bound = visit(arg);
4240 if (arg != bound) {
4241 changed = true;
4242 }
4243 rewritten.append(bound);
4244 }
4245 if (changed)
4246 return subst(t.tsym.type,
4247 t.tsym.type.allparams(),
4248 rewritten.toList());
4249 else
4250 return t;
4251 }
4253 public Type visitType(Type t, Void s) {
4254 return high ? upperBound(t) : lowerBound(t);
4255 }
4257 @Override
4258 public Type visitCapturedType(CapturedType t, Void s) {
4259 Type w_bound = t.wildcard.type;
4260 Type bound = w_bound.contains(t) ?
4261 erasure(w_bound) :
4262 visit(w_bound);
4263 return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind);
4264 }
4266 @Override
4267 public Type visitTypeVar(TypeVar t, Void s) {
4268 if (rewriteTypeVars) {
4269 Type bound = t.bound.contains(t) ?
4270 erasure(t.bound) :
4271 visit(t.bound);
4272 return rewriteAsWildcardType(bound, t, EXTENDS);
4273 } else {
4274 return t;
4275 }
4276 }
4278 @Override
4279 public Type visitWildcardType(WildcardType t, Void s) {
4280 Type bound2 = visit(t.type);
4281 return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind);
4282 }
4284 private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) {
4285 switch (bk) {
4286 case EXTENDS: return high ?
4287 makeExtendsWildcard(B(bound), formal) :
4288 makeExtendsWildcard(syms.objectType, formal);
4289 case SUPER: return high ?
4290 makeSuperWildcard(syms.botType, formal) :
4291 makeSuperWildcard(B(bound), formal);
4292 case UNBOUND: return makeExtendsWildcard(syms.objectType, formal);
4293 default:
4294 Assert.error("Invalid bound kind " + bk);
4295 return null;
4296 }
4297 }
4299 Type B(Type t) {
4300 while (t.hasTag(WILDCARD)) {
4301 WildcardType w = (WildcardType)t.unannotatedType();
4302 t = high ?
4303 w.getExtendsBound() :
4304 w.getSuperBound();
4305 if (t == null) {
4306 t = high ? syms.objectType : syms.botType;
4307 }
4308 }
4309 return t;
4310 }
4311 }
4314 /**
4315 * Create a wildcard with the given upper (extends) bound; create
4316 * an unbounded wildcard if bound is Object.
4317 *
4318 * @param bound the upper bound
4319 * @param formal the formal type parameter that will be
4320 * substituted by the wildcard
4321 */
4322 private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) {
4323 if (bound == syms.objectType) {
4324 return new WildcardType(syms.objectType,
4325 BoundKind.UNBOUND,
4326 syms.boundClass,
4327 formal);
4328 } else {
4329 return new WildcardType(bound,
4330 BoundKind.EXTENDS,
4331 syms.boundClass,
4332 formal);
4333 }
4334 }
4336 /**
4337 * Create a wildcard with the given lower (super) bound; create an
4338 * unbounded wildcard if bound is bottom (type of {@code null}).
4339 *
4340 * @param bound the lower bound
4341 * @param formal the formal type parameter that will be
4342 * substituted by the wildcard
4343 */
4344 private WildcardType makeSuperWildcard(Type bound, TypeVar formal) {
4345 if (bound.hasTag(BOT)) {
4346 return new WildcardType(syms.objectType,
4347 BoundKind.UNBOUND,
4348 syms.boundClass,
4349 formal);
4350 } else {
4351 return new WildcardType(bound,
4352 BoundKind.SUPER,
4353 syms.boundClass,
4354 formal);
4355 }
4356 }
4358 /**
4359 * A wrapper for a type that allows use in sets.
4360 */
4361 public static class UniqueType {
4362 public final Type type;
4363 final Types types;
4365 public UniqueType(Type type, Types types) {
4366 this.type = type;
4367 this.types = types;
4368 }
4370 public int hashCode() {
4371 return types.hashCode(type);
4372 }
4374 public boolean equals(Object obj) {
4375 return (obj instanceof UniqueType) &&
4376 types.isSameAnnotatedType(type, ((UniqueType)obj).type);
4377 }
4379 public String toString() {
4380 return type.toString();
4381 }
4383 }
4384 // </editor-fold>
4386 // <editor-fold defaultstate="collapsed" desc="Visitors">
4387 /**
4388 * A default visitor for types. All visitor methods except
4389 * visitType are implemented by delegating to visitType. Concrete
4390 * subclasses must provide an implementation of visitType and can
4391 * override other methods as needed.
4392 *
4393 * @param <R> the return type of the operation implemented by this
4394 * visitor; use Void if no return type is needed.
4395 * @param <S> the type of the second argument (the first being the
4396 * type itself) of the operation implemented by this visitor; use
4397 * Void if a second argument is not needed.
4398 */
4399 public static abstract class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> {
4400 final public R visit(Type t, S s) { return t.accept(this, s); }
4401 public R visitClassType(ClassType t, S s) { return visitType(t, s); }
4402 public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); }
4403 public R visitArrayType(ArrayType t, S s) { return visitType(t, s); }
4404 public R visitMethodType(MethodType t, S s) { return visitType(t, s); }
4405 public R visitPackageType(PackageType t, S s) { return visitType(t, s); }
4406 public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); }
4407 public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); }
4408 public R visitForAll(ForAll t, S s) { return visitType(t, s); }
4409 public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); }
4410 public R visitErrorType(ErrorType t, S s) { return visitType(t, s); }
4411 // Pretend annotations don't exist
4412 public R visitAnnotatedType(AnnotatedType t, S s) { return visit(t.unannotatedType(), s); }
4413 }
4415 /**
4416 * A default visitor for symbols. All visitor methods except
4417 * visitSymbol are implemented by delegating to visitSymbol. Concrete
4418 * subclasses must provide an implementation of visitSymbol and can
4419 * override other methods as needed.
4420 *
4421 * @param <R> the return type of the operation implemented by this
4422 * visitor; use Void if no return type is needed.
4423 * @param <S> the type of the second argument (the first being the
4424 * symbol itself) of the operation implemented by this visitor; use
4425 * Void if a second argument is not needed.
4426 */
4427 public static abstract class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> {
4428 final public R visit(Symbol s, S arg) { return s.accept(this, arg); }
4429 public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); }
4430 public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); }
4431 public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); }
4432 public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); }
4433 public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); }
4434 public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); }
4435 }
4437 /**
4438 * A <em>simple</em> visitor for types. This visitor is simple as
4439 * captured wildcards, for-all types (generic methods), and
4440 * undetermined type variables (part of inference) are hidden.
4441 * Captured wildcards are hidden by treating them as type
4442 * variables and the rest are hidden by visiting their qtypes.
4443 *
4444 * @param <R> the return type of the operation implemented by this
4445 * visitor; use Void if no return type is needed.
4446 * @param <S> the type of the second argument (the first being the
4447 * type itself) of the operation implemented by this visitor; use
4448 * Void if a second argument is not needed.
4449 */
4450 public static abstract class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> {
4451 @Override
4452 public R visitCapturedType(CapturedType t, S s) {
4453 return visitTypeVar(t, s);
4454 }
4455 @Override
4456 public R visitForAll(ForAll t, S s) {
4457 return visit(t.qtype, s);
4458 }
4459 @Override
4460 public R visitUndetVar(UndetVar t, S s) {
4461 return visit(t.qtype, s);
4462 }
4463 }
4465 /**
4466 * A plain relation on types. That is a 2-ary function on the
4467 * form Type × Type → Boolean.
4468 * <!-- In plain text: Type x Type -> Boolean -->
4469 */
4470 public static abstract class TypeRelation extends SimpleVisitor<Boolean,Type> {}
4472 /**
4473 * A convenience visitor for implementing operations that only
4474 * require one argument (the type itself), that is, unary
4475 * operations.
4476 *
4477 * @param <R> the return type of the operation implemented by this
4478 * visitor; use Void if no return type is needed.
4479 */
4480 public static abstract class UnaryVisitor<R> extends SimpleVisitor<R,Void> {
4481 final public R visit(Type t) { return t.accept(this, null); }
4482 }
4484 /**
4485 * A visitor for implementing a mapping from types to types. The
4486 * default behavior of this class is to implement the identity
4487 * mapping (mapping a type to itself). This can be overridden in
4488 * subclasses.
4489 *
4490 * @param <S> the type of the second argument (the first being the
4491 * type itself) of this mapping; use Void if a second argument is
4492 * not needed.
4493 */
4494 public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> {
4495 final public Type visit(Type t) { return t.accept(this, null); }
4496 public Type visitType(Type t, S s) { return t; }
4497 }
4498 // </editor-fold>
4501 // <editor-fold defaultstate="collapsed" desc="Annotation support">
4503 public RetentionPolicy getRetention(Attribute.Compound a) {
4504 return getRetention(a.type.tsym);
4505 }
4507 public RetentionPolicy getRetention(Symbol sym) {
4508 RetentionPolicy vis = RetentionPolicy.CLASS; // the default
4509 Attribute.Compound c = sym.attribute(syms.retentionType.tsym);
4510 if (c != null) {
4511 Attribute value = c.member(names.value);
4512 if (value != null && value instanceof Attribute.Enum) {
4513 Name levelName = ((Attribute.Enum)value).value.name;
4514 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE;
4515 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS;
4516 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME;
4517 else ;// /* fail soft */ throw new AssertionError(levelName);
4518 }
4519 }
4520 return vis;
4521 }
4522 // </editor-fold>
4524 // <editor-fold defaultstate="collapsed" desc="Signature Generation">
4526 public static abstract class SignatureGenerator {
4528 private final Types types;
4530 protected abstract void append(char ch);
4531 protected abstract void append(byte[] ba);
4532 protected abstract void append(Name name);
4533 protected void classReference(ClassSymbol c) { /* by default: no-op */ }
4535 protected SignatureGenerator(Types types) {
4536 this.types = types;
4537 }
4539 /**
4540 * Assemble signature of given type in string buffer.
4541 */
4542 public void assembleSig(Type type) {
4543 type = type.unannotatedType();
4544 switch (type.getTag()) {
4545 case BYTE:
4546 append('B');
4547 break;
4548 case SHORT:
4549 append('S');
4550 break;
4551 case CHAR:
4552 append('C');
4553 break;
4554 case INT:
4555 append('I');
4556 break;
4557 case LONG:
4558 append('J');
4559 break;
4560 case FLOAT:
4561 append('F');
4562 break;
4563 case DOUBLE:
4564 append('D');
4565 break;
4566 case BOOLEAN:
4567 append('Z');
4568 break;
4569 case VOID:
4570 append('V');
4571 break;
4572 case CLASS:
4573 append('L');
4574 assembleClassSig(type);
4575 append(';');
4576 break;
4577 case ARRAY:
4578 ArrayType at = (ArrayType) type;
4579 append('[');
4580 assembleSig(at.elemtype);
4581 break;
4582 case METHOD:
4583 MethodType mt = (MethodType) type;
4584 append('(');
4585 assembleSig(mt.argtypes);
4586 append(')');
4587 assembleSig(mt.restype);
4588 if (hasTypeVar(mt.thrown)) {
4589 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) {
4590 append('^');
4591 assembleSig(l.head);
4592 }
4593 }
4594 break;
4595 case WILDCARD: {
4596 Type.WildcardType ta = (Type.WildcardType) type;
4597 switch (ta.kind) {
4598 case SUPER:
4599 append('-');
4600 assembleSig(ta.type);
4601 break;
4602 case EXTENDS:
4603 append('+');
4604 assembleSig(ta.type);
4605 break;
4606 case UNBOUND:
4607 append('*');
4608 break;
4609 default:
4610 throw new AssertionError(ta.kind);
4611 }
4612 break;
4613 }
4614 case TYPEVAR:
4615 append('T');
4616 append(type.tsym.name);
4617 append(';');
4618 break;
4619 case FORALL:
4620 Type.ForAll ft = (Type.ForAll) type;
4621 assembleParamsSig(ft.tvars);
4622 assembleSig(ft.qtype);
4623 break;
4624 default:
4625 throw new AssertionError("typeSig " + type.getTag());
4626 }
4627 }
4629 public boolean hasTypeVar(List<Type> l) {
4630 while (l.nonEmpty()) {
4631 if (l.head.hasTag(TypeTag.TYPEVAR)) {
4632 return true;
4633 }
4634 l = l.tail;
4635 }
4636 return false;
4637 }
4639 public void assembleClassSig(Type type) {
4640 type = type.unannotatedType();
4641 ClassType ct = (ClassType) type;
4642 ClassSymbol c = (ClassSymbol) ct.tsym;
4643 classReference(c);
4644 Type outer = ct.getEnclosingType();
4645 if (outer.allparams().nonEmpty()) {
4646 boolean rawOuter =
4647 c.owner.kind == Kinds.MTH || // either a local class
4648 c.name == types.names.empty; // or anonymous
4649 assembleClassSig(rawOuter
4650 ? types.erasure(outer)
4651 : outer);
4652 append('.');
4653 Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname));
4654 append(rawOuter
4655 ? c.flatname.subName(c.owner.enclClass().flatname.getByteLength() + 1, c.flatname.getByteLength())
4656 : c.name);
4657 } else {
4658 append(externalize(c.flatname));
4659 }
4660 if (ct.getTypeArguments().nonEmpty()) {
4661 append('<');
4662 assembleSig(ct.getTypeArguments());
4663 append('>');
4664 }
4665 }
4667 public void assembleParamsSig(List<Type> typarams) {
4668 append('<');
4669 for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) {
4670 Type.TypeVar tvar = (Type.TypeVar) ts.head;
4671 append(tvar.tsym.name);
4672 List<Type> bounds = types.getBounds(tvar);
4673 if ((bounds.head.tsym.flags() & INTERFACE) != 0) {
4674 append(':');
4675 }
4676 for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) {
4677 append(':');
4678 assembleSig(l.head);
4679 }
4680 }
4681 append('>');
4682 }
4684 private void assembleSig(List<Type> types) {
4685 for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) {
4686 assembleSig(ts.head);
4687 }
4688 }
4689 }
4690 // </editor-fold>
4691 }
