Tue, 26 Feb 2013 09:04:19 +0000
8008436: javac should not issue a warning for overriding equals without hasCode if hashCode has been overriden by a superclass
Reviewed-by: jjg, mcimadamore
1 /*
2 * Copyright (c) 1999, 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.util.Set;
29 import java.util.concurrent.Callable;
31 import javax.lang.model.element.*;
32 import javax.tools.JavaFileObject;
34 import com.sun.tools.javac.code.Type.*;
35 import com.sun.tools.javac.comp.Attr;
36 import com.sun.tools.javac.comp.AttrContext;
37 import com.sun.tools.javac.comp.Env;
38 import com.sun.tools.javac.jvm.*;
39 import com.sun.tools.javac.model.*;
40 import com.sun.tools.javac.tree.JCTree;
41 import com.sun.tools.javac.util.*;
42 import com.sun.tools.javac.util.Name;
43 import static com.sun.tools.javac.code.Flags.*;
44 import static com.sun.tools.javac.code.Kinds.*;
45 import static com.sun.tools.javac.code.TypeTag.CLASS;
46 import static com.sun.tools.javac.code.TypeTag.FORALL;
47 import static com.sun.tools.javac.code.TypeTag.TYPEVAR;
49 /** Root class for Java symbols. It contains subclasses
50 * for specific sorts of symbols, such as variables, methods and operators,
51 * types, packages. Each subclass is represented as a static inner class
52 * inside Symbol.
53 *
54 * <p><b>This is NOT part of any supported API.
55 * If you write code that depends on this, you do so at your own risk.
56 * This code and its internal interfaces are subject to change or
57 * deletion without notice.</b>
58 */
59 public abstract class Symbol implements Element {
60 // public Throwable debug = new Throwable();
62 /** The kind of this symbol.
63 * @see Kinds
64 */
65 public int kind;
67 /** The flags of this symbol.
68 */
69 public long flags_field;
71 /** An accessor method for the flags of this symbol.
72 * Flags of class symbols should be accessed through the accessor
73 * method to make sure that the class symbol is loaded.
74 */
75 public long flags() { return flags_field; }
77 /** The attributes of this symbol are contained in this
78 * Annotations. The Annotations instance is NOT immutable.
79 */
80 public final Annotations annotations = new Annotations(this);
82 /** An accessor method for the attributes of this symbol.
83 * Attributes of class symbols should be accessed through the accessor
84 * method to make sure that the class symbol is loaded.
85 */
86 public List<Attribute.Compound> getRawAttributes() {
87 return annotations.getDeclarationAttributes();
88 }
90 /** An accessor method for the type attributes of this symbol.
91 * Attributes of class symbols should be accessed through the accessor
92 * method to make sure that the class symbol is loaded.
93 */
94 public List<Attribute.TypeCompound> getRawTypeAttributes() {
95 return annotations.getTypeAttributes();
96 }
98 /** Fetch a particular annotation from a symbol. */
99 public Attribute.Compound attribute(Symbol anno) {
100 for (Attribute.Compound a : getRawAttributes()) {
101 if (a.type.tsym == anno) return a;
102 }
103 return null;
104 }
106 /** The name of this symbol in Utf8 representation.
107 */
108 public Name name;
110 /** The type of this symbol.
111 */
112 public Type type;
114 /** The owner of this symbol.
115 */
116 public Symbol owner;
118 /** The completer of this symbol.
119 */
120 public Completer completer;
122 /** A cache for the type erasure of this symbol.
123 */
124 public Type erasure_field;
126 /** Construct a symbol with given kind, flags, name, type and owner.
127 */
128 public Symbol(int kind, long flags, Name name, Type type, Symbol owner) {
129 this.kind = kind;
130 this.flags_field = flags;
131 this.type = type;
132 this.owner = owner;
133 this.completer = null;
134 this.erasure_field = null;
135 this.name = name;
136 }
138 /** Clone this symbol with new owner.
139 * Legal only for fields and methods.
140 */
141 public Symbol clone(Symbol newOwner) {
142 throw new AssertionError();
143 }
145 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
146 return v.visitSymbol(this, p);
147 }
149 /** The Java source which this symbol represents.
150 * A description of this symbol; overrides Object.
151 */
152 public String toString() {
153 return name.toString();
154 }
156 /** A Java source description of the location of this symbol; used for
157 * error reporting.
158 *
159 * @return null if the symbol is a package or a toplevel class defined in
160 * the default package; otherwise, the owner symbol is returned
161 */
162 public Symbol location() {
163 if (owner.name == null || (owner.name.isEmpty() &&
164 (owner.flags() & BLOCK) == 0 && owner.kind != PCK && owner.kind != TYP)) {
165 return null;
166 }
167 return owner;
168 }
170 public Symbol location(Type site, Types types) {
171 if (owner.name == null || owner.name.isEmpty()) {
172 return location();
173 }
174 if (owner.type.hasTag(CLASS)) {
175 Type ownertype = types.asOuterSuper(site, owner);
176 if (ownertype != null) return ownertype.tsym;
177 }
178 return owner;
179 }
181 public Symbol baseSymbol() {
182 return this;
183 }
185 /** The symbol's erased type.
186 */
187 public Type erasure(Types types) {
188 if (erasure_field == null)
189 erasure_field = types.erasure(type);
190 return erasure_field;
191 }
193 /** The external type of a symbol. This is the symbol's erased type
194 * except for constructors of inner classes which get the enclosing
195 * instance class added as first argument.
196 */
197 public Type externalType(Types types) {
198 Type t = erasure(types);
199 if (name == name.table.names.init && owner.hasOuterInstance()) {
200 Type outerThisType = types.erasure(owner.type.getEnclosingType());
201 return new MethodType(t.getParameterTypes().prepend(outerThisType),
202 t.getReturnType(),
203 t.getThrownTypes(),
204 t.tsym);
205 } else {
206 return t;
207 }
208 }
210 public boolean isStatic() {
211 return
212 (flags() & STATIC) != 0 ||
213 (owner.flags() & INTERFACE) != 0 && kind != MTH;
214 }
216 public boolean isInterface() {
217 return (flags() & INTERFACE) != 0;
218 }
220 public boolean isPrivate() {
221 return (flags_field & Flags.AccessFlags) == PRIVATE;
222 }
224 public boolean isEnum() {
225 return (flags() & ENUM) != 0;
226 }
228 /** Is this symbol declared (directly or indirectly) local
229 * to a method or variable initializer?
230 * Also includes fields of inner classes which are in
231 * turn local to a method or variable initializer.
232 */
233 public boolean isLocal() {
234 return
235 (owner.kind & (VAR | MTH)) != 0 ||
236 (owner.kind == TYP && owner.isLocal());
237 }
239 /** Has this symbol an empty name? This includes anonymous
240 * inner classses.
241 */
242 public boolean isAnonymous() {
243 return name.isEmpty();
244 }
246 /** Is this symbol a constructor?
247 */
248 public boolean isConstructor() {
249 return name == name.table.names.init;
250 }
252 /** The fully qualified name of this symbol.
253 * This is the same as the symbol's name except for class symbols,
254 * which are handled separately.
255 */
256 public Name getQualifiedName() {
257 return name;
258 }
260 /** The fully qualified name of this symbol after converting to flat
261 * representation. This is the same as the symbol's name except for
262 * class symbols, which are handled separately.
263 */
264 public Name flatName() {
265 return getQualifiedName();
266 }
268 /** If this is a class or package, its members, otherwise null.
269 */
270 public Scope members() {
271 return null;
272 }
274 /** A class is an inner class if it it has an enclosing instance class.
275 */
276 public boolean isInner() {
277 return type.getEnclosingType().hasTag(CLASS);
278 }
280 /** An inner class has an outer instance if it is not an interface
281 * it has an enclosing instance class which might be referenced from the class.
282 * Nested classes can see instance members of their enclosing class.
283 * Their constructors carry an additional this$n parameter, inserted
284 * implicitly by the compiler.
285 *
286 * @see #isInner
287 */
288 public boolean hasOuterInstance() {
289 return
290 type.getEnclosingType().hasTag(CLASS) && (flags() & (INTERFACE | NOOUTERTHIS)) == 0;
291 }
293 /** The closest enclosing class of this symbol's declaration.
294 */
295 public ClassSymbol enclClass() {
296 Symbol c = this;
297 while (c != null &&
298 ((c.kind & TYP) == 0 || !c.type.hasTag(CLASS))) {
299 c = c.owner;
300 }
301 return (ClassSymbol)c;
302 }
304 /** The outermost class which indirectly owns this symbol.
305 */
306 public ClassSymbol outermostClass() {
307 Symbol sym = this;
308 Symbol prev = null;
309 while (sym.kind != PCK) {
310 prev = sym;
311 sym = sym.owner;
312 }
313 return (ClassSymbol) prev;
314 }
316 /** The package which indirectly owns this symbol.
317 */
318 public PackageSymbol packge() {
319 Symbol sym = this;
320 while (sym.kind != PCK) {
321 sym = sym.owner;
322 }
323 return (PackageSymbol) sym;
324 }
326 /** Is this symbol a subclass of `base'? Only defined for ClassSymbols.
327 */
328 public boolean isSubClass(Symbol base, Types types) {
329 throw new AssertionError("isSubClass " + this);
330 }
332 /** Fully check membership: hierarchy, protection, and hiding.
333 * Does not exclude methods not inherited due to overriding.
334 */
335 public boolean isMemberOf(TypeSymbol clazz, Types types) {
336 return
337 owner == clazz ||
338 clazz.isSubClass(owner, types) &&
339 isInheritedIn(clazz, types) &&
340 !hiddenIn((ClassSymbol)clazz, types);
341 }
343 /** Is this symbol the same as or enclosed by the given class? */
344 public boolean isEnclosedBy(ClassSymbol clazz) {
345 for (Symbol sym = this; sym.kind != PCK; sym = sym.owner)
346 if (sym == clazz) return true;
347 return false;
348 }
350 /** Check for hiding. Note that this doesn't handle multiple
351 * (interface) inheritance. */
352 private boolean hiddenIn(ClassSymbol clazz, Types types) {
353 if (kind == MTH && (flags() & STATIC) == 0) return false;
354 while (true) {
355 if (owner == clazz) return false;
356 Scope.Entry e = clazz.members().lookup(name);
357 while (e.scope != null) {
358 if (e.sym == this) return false;
359 if (e.sym.kind == kind &&
360 (kind != MTH ||
361 (e.sym.flags() & STATIC) != 0 &&
362 types.isSubSignature(e.sym.type, type)))
363 return true;
364 e = e.next();
365 }
366 Type superType = types.supertype(clazz.type);
367 if (!superType.hasTag(CLASS)) return false;
368 clazz = (ClassSymbol)superType.tsym;
369 }
370 }
372 /** Is this symbol inherited into a given class?
373 * PRE: If symbol's owner is a interface,
374 * it is already assumed that the interface is a superinterface
375 * of given class.
376 * @param clazz The class for which we want to establish membership.
377 * This must be a subclass of the member's owner.
378 */
379 public boolean isInheritedIn(Symbol clazz, Types types) {
380 switch ((int)(flags_field & Flags.AccessFlags)) {
381 default: // error recovery
382 case PUBLIC:
383 return true;
384 case PRIVATE:
385 return this.owner == clazz;
386 case PROTECTED:
387 // we model interfaces as extending Object
388 return (clazz.flags() & INTERFACE) == 0;
389 case 0:
390 PackageSymbol thisPackage = this.packge();
391 for (Symbol sup = clazz;
392 sup != null && sup != this.owner;
393 sup = types.supertype(sup.type).tsym) {
394 while (sup.type.hasTag(TYPEVAR))
395 sup = sup.type.getUpperBound().tsym;
396 if (sup.type.isErroneous())
397 return true; // error recovery
398 if ((sup.flags() & COMPOUND) != 0)
399 continue;
400 if (sup.packge() != thisPackage)
401 return false;
402 }
403 return (clazz.flags() & INTERFACE) == 0;
404 }
405 }
407 /** The (variable or method) symbol seen as a member of given
408 * class type`site' (this might change the symbol's type).
409 * This is used exclusively for producing diagnostics.
410 */
411 public Symbol asMemberOf(Type site, Types types) {
412 throw new AssertionError();
413 }
415 /** Does this method symbol override `other' symbol, when both are seen as
416 * members of class `origin'? It is assumed that _other is a member
417 * of origin.
418 *
419 * It is assumed that both symbols have the same name. The static
420 * modifier is ignored for this test.
421 *
422 * See JLS 8.4.6.1 (without transitivity) and 8.4.6.4
423 */
424 public boolean overrides(Symbol _other, TypeSymbol origin, Types types, boolean checkResult) {
425 return false;
426 }
428 /** Complete the elaboration of this symbol's definition.
429 */
430 public void complete() throws CompletionFailure {
431 if (completer != null) {
432 Completer c = completer;
433 completer = null;
434 c.complete(this);
435 }
436 }
438 /** True if the symbol represents an entity that exists.
439 */
440 public boolean exists() {
441 return true;
442 }
444 public Type asType() {
445 return type;
446 }
448 public Symbol getEnclosingElement() {
449 return owner;
450 }
452 public ElementKind getKind() {
453 return ElementKind.OTHER; // most unkind
454 }
456 public Set<Modifier> getModifiers() {
457 long flags = flags();
458 return Flags.asModifierSet((flags & DEFAULT) != 0 ? flags & ~ABSTRACT : flags);
459 }
461 public Name getSimpleName() {
462 return name;
463 }
465 /**
466 * This is the implementation for {@code
467 * javax.lang.model.element.Element.getAnnotationMirrors()}.
468 */
469 public final List<? extends AnnotationMirror> getAnnotationMirrors() {
470 return getRawAttributes();
471 }
473 /**
474 * TODO: Should there be a {@code
475 * javax.lang.model.element.Element.getTypeAnnotationMirrors()}.
476 */
477 public final List<Attribute.TypeCompound> getTypeAnnotationMirrors() {
478 return getRawTypeAttributes();
479 }
481 /**
482 * @deprecated this method should never be used by javac internally.
483 */
484 @Deprecated
485 public <A extends java.lang.annotation.Annotation> A getAnnotation(Class<A> annoType) {
486 return JavacElements.getAnnotation(this, annoType);
487 }
489 // This method is part of the javax.lang.model API, do not use this in javac code.
490 public <A extends java.lang.annotation.Annotation> A[] getAnnotationsByType(Class<A> annoType) {
491 return JavacElements.getAnnotations(this, annoType);
492 }
494 // TODO: getEnclosedElements should return a javac List, fix in FilteredMemberList
495 public java.util.List<Symbol> getEnclosedElements() {
496 return List.nil();
497 }
499 public List<TypeSymbol> getTypeParameters() {
500 ListBuffer<TypeSymbol> l = ListBuffer.lb();
501 for (Type t : type.getTypeArguments()) {
502 l.append(t.tsym);
503 }
504 return l.toList();
505 }
507 public static class DelegatedSymbol<T extends Symbol> extends Symbol {
508 protected T other;
509 public DelegatedSymbol(T other) {
510 super(other.kind, other.flags_field, other.name, other.type, other.owner);
511 this.other = other;
512 }
513 public String toString() { return other.toString(); }
514 public Symbol location() { return other.location(); }
515 public Symbol location(Type site, Types types) { return other.location(site, types); }
516 public Symbol baseSymbol() { return other; }
517 public Type erasure(Types types) { return other.erasure(types); }
518 public Type externalType(Types types) { return other.externalType(types); }
519 public boolean isLocal() { return other.isLocal(); }
520 public boolean isConstructor() { return other.isConstructor(); }
521 public Name getQualifiedName() { return other.getQualifiedName(); }
522 public Name flatName() { return other.flatName(); }
523 public Scope members() { return other.members(); }
524 public boolean isInner() { return other.isInner(); }
525 public boolean hasOuterInstance() { return other.hasOuterInstance(); }
526 public ClassSymbol enclClass() { return other.enclClass(); }
527 public ClassSymbol outermostClass() { return other.outermostClass(); }
528 public PackageSymbol packge() { return other.packge(); }
529 public boolean isSubClass(Symbol base, Types types) { return other.isSubClass(base, types); }
530 public boolean isMemberOf(TypeSymbol clazz, Types types) { return other.isMemberOf(clazz, types); }
531 public boolean isEnclosedBy(ClassSymbol clazz) { return other.isEnclosedBy(clazz); }
532 public boolean isInheritedIn(Symbol clazz, Types types) { return other.isInheritedIn(clazz, types); }
533 public Symbol asMemberOf(Type site, Types types) { return other.asMemberOf(site, types); }
534 public void complete() throws CompletionFailure { other.complete(); }
536 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
537 return other.accept(v, p);
538 }
540 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
541 return v.visitSymbol(other, p);
542 }
544 public T getUnderlyingSymbol() {
545 return other;
546 }
547 }
549 /** A class for type symbols. Type variables are represented by instances
550 * of this class, classes and packages by instances of subclasses.
551 */
552 public static class TypeSymbol
553 extends Symbol implements TypeParameterElement {
554 // Implements TypeParameterElement because type parameters don't
555 // have their own TypeSymbol subclass.
556 // TODO: type parameters should have their own TypeSymbol subclass
558 public TypeSymbol(long flags, Name name, Type type, Symbol owner) {
559 super(TYP, flags, name, type, owner);
560 }
562 /** form a fully qualified name from a name and an owner
563 */
564 static public Name formFullName(Name name, Symbol owner) {
565 if (owner == null) return name;
566 if (((owner.kind != ERR)) &&
567 ((owner.kind & (VAR | MTH)) != 0
568 || (owner.kind == TYP && owner.type.hasTag(TYPEVAR))
569 )) return name;
570 Name prefix = owner.getQualifiedName();
571 if (prefix == null || prefix == prefix.table.names.empty)
572 return name;
573 else return prefix.append('.', name);
574 }
576 /** form a fully qualified name from a name and an owner, after
577 * converting to flat representation
578 */
579 static public Name formFlatName(Name name, Symbol owner) {
580 if (owner == null ||
581 (owner.kind & (VAR | MTH)) != 0
582 || (owner.kind == TYP && owner.type.hasTag(TYPEVAR))
583 ) return name;
584 char sep = owner.kind == TYP ? '$' : '.';
585 Name prefix = owner.flatName();
586 if (prefix == null || prefix == prefix.table.names.empty)
587 return name;
588 else return prefix.append(sep, name);
589 }
591 /**
592 * A total ordering between type symbols that refines the
593 * class inheritance graph.
594 *
595 * Typevariables always precede other kinds of symbols.
596 */
597 public final boolean precedes(TypeSymbol that, Types types) {
598 if (this == that)
599 return false;
600 if (this.type.tag == that.type.tag) {
601 if (this.type.hasTag(CLASS)) {
602 return
603 types.rank(that.type) < types.rank(this.type) ||
604 types.rank(that.type) == types.rank(this.type) &&
605 that.getQualifiedName().compareTo(this.getQualifiedName()) < 0;
606 } else if (this.type.hasTag(TYPEVAR)) {
607 return types.isSubtype(this.type, that.type);
608 }
609 }
610 return this.type.hasTag(TYPEVAR);
611 }
613 // For type params; overridden in subclasses.
614 public ElementKind getKind() {
615 return ElementKind.TYPE_PARAMETER;
616 }
618 public java.util.List<Symbol> getEnclosedElements() {
619 List<Symbol> list = List.nil();
620 if (kind == TYP && type.hasTag(TYPEVAR)) {
621 return list;
622 }
623 for (Scope.Entry e = members().elems; e != null; e = e.sibling) {
624 if (e.sym != null && (e.sym.flags() & SYNTHETIC) == 0 && e.sym.owner == this)
625 list = list.prepend(e.sym);
626 }
627 return list;
628 }
630 // For type params.
631 // Perhaps not needed if getEnclosingElement can be spec'ed
632 // to do the same thing.
633 // TODO: getGenericElement() might not be needed
634 public Symbol getGenericElement() {
635 return owner;
636 }
638 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
639 Assert.check(type.hasTag(TYPEVAR)); // else override will be invoked
640 return v.visitTypeParameter(this, p);
641 }
643 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
644 return v.visitTypeSymbol(this, p);
645 }
647 public List<Type> getBounds() {
648 TypeVar t = (TypeVar)type;
649 Type bound = t.getUpperBound();
650 if (!bound.isCompound())
651 return List.of(bound);
652 ClassType ct = (ClassType)bound;
653 if (!ct.tsym.erasure_field.isInterface()) {
654 return ct.interfaces_field.prepend(ct.supertype_field);
655 } else {
656 // No superclass was given in bounds.
657 // In this case, supertype is Object, erasure is first interface.
658 return ct.interfaces_field;
659 }
660 }
661 }
663 /** A class for package symbols
664 */
665 public static class PackageSymbol extends TypeSymbol
666 implements PackageElement {
668 public Scope members_field;
669 public Name fullname;
670 public ClassSymbol package_info; // see bug 6443073
672 public PackageSymbol(Name name, Type type, Symbol owner) {
673 super(0, name, type, owner);
674 this.kind = PCK;
675 this.members_field = null;
676 this.fullname = formFullName(name, owner);
677 }
679 public PackageSymbol(Name name, Symbol owner) {
680 this(name, null, owner);
681 this.type = new PackageType(this);
682 }
684 public String toString() {
685 return fullname.toString();
686 }
688 public Name getQualifiedName() {
689 return fullname;
690 }
692 public boolean isUnnamed() {
693 return name.isEmpty() && owner != null;
694 }
696 public Scope members() {
697 if (completer != null) complete();
698 return members_field;
699 }
701 public long flags() {
702 if (completer != null) complete();
703 return flags_field;
704 }
706 @Override
707 public List<Attribute.Compound> getRawAttributes() {
708 if (completer != null) complete();
709 if (package_info != null && package_info.completer != null) {
710 package_info.complete();
711 mergeAttributes();
712 }
713 return super.getRawAttributes();
714 }
716 private void mergeAttributes() {
717 if (annotations.isEmpty() &&
718 !package_info.annotations.isEmpty()) {
719 annotations.setAttributes(package_info.annotations);
720 }
721 }
723 /** A package "exists" if a type or package that exists has
724 * been seen within it.
725 */
726 public boolean exists() {
727 return (flags_field & EXISTS) != 0;
728 }
730 public ElementKind getKind() {
731 return ElementKind.PACKAGE;
732 }
734 public Symbol getEnclosingElement() {
735 return null;
736 }
738 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
739 return v.visitPackage(this, p);
740 }
742 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
743 return v.visitPackageSymbol(this, p);
744 }
745 }
747 /** A class for class symbols
748 */
749 public static class ClassSymbol extends TypeSymbol implements TypeElement {
751 /** a scope for all class members; variables, methods and inner classes
752 * type parameters are not part of this scope
753 */
754 public Scope members_field;
756 /** the fully qualified name of the class, i.e. pck.outer.inner.
757 * null for anonymous classes
758 */
759 public Name fullname;
761 /** the fully qualified name of the class after converting to flat
762 * representation, i.e. pck.outer$inner,
763 * set externally for local and anonymous classes
764 */
765 public Name flatname;
767 /** the sourcefile where the class came from
768 */
769 public JavaFileObject sourcefile;
771 /** the classfile from where to load this class
772 * this will have extension .class or .java
773 */
774 public JavaFileObject classfile;
776 /** the list of translated local classes (used for generating
777 * InnerClasses attribute)
778 */
779 public List<ClassSymbol> trans_local;
781 /** the constant pool of the class
782 */
783 public Pool pool;
785 public ClassSymbol(long flags, Name name, Type type, Symbol owner) {
786 super(flags, name, type, owner);
787 this.members_field = null;
788 this.fullname = formFullName(name, owner);
789 this.flatname = formFlatName(name, owner);
790 this.sourcefile = null;
791 this.classfile = null;
792 this.pool = null;
793 }
795 public ClassSymbol(long flags, Name name, Symbol owner) {
796 this(
797 flags,
798 name,
799 new ClassType(Type.noType, null, null),
800 owner);
801 this.type.tsym = this;
802 }
804 /** The Java source which this symbol represents.
805 */
806 public String toString() {
807 return className();
808 }
810 public long flags() {
811 if (completer != null) complete();
812 return flags_field;
813 }
815 public Scope members() {
816 if (completer != null) complete();
817 return members_field;
818 }
820 @Override
821 public List<Attribute.Compound> getRawAttributes() {
822 if (completer != null) complete();
823 return super.getRawAttributes();
824 }
826 @Override
827 public List<Attribute.TypeCompound> getRawTypeAttributes() {
828 if (completer != null) complete();
829 return super.getRawTypeAttributes();
830 }
832 public Type erasure(Types types) {
833 if (erasure_field == null)
834 erasure_field = new ClassType(types.erasure(type.getEnclosingType()),
835 List.<Type>nil(), this);
836 return erasure_field;
837 }
839 public String className() {
840 if (name.isEmpty())
841 return
842 Log.getLocalizedString("anonymous.class", flatname);
843 else
844 return fullname.toString();
845 }
847 public Name getQualifiedName() {
848 return fullname;
849 }
851 public Name flatName() {
852 return flatname;
853 }
855 public boolean isSubClass(Symbol base, Types types) {
856 if (this == base) {
857 return true;
858 } else if ((base.flags() & INTERFACE) != 0) {
859 for (Type t = type; t.hasTag(CLASS); t = types.supertype(t))
860 for (List<Type> is = types.interfaces(t);
861 is.nonEmpty();
862 is = is.tail)
863 if (is.head.tsym.isSubClass(base, types)) return true;
864 } else {
865 for (Type t = type; t.hasTag(CLASS); t = types.supertype(t))
866 if (t.tsym == base) return true;
867 }
868 return false;
869 }
871 /** Complete the elaboration of this symbol's definition.
872 */
873 public void complete() throws CompletionFailure {
874 try {
875 super.complete();
876 } catch (CompletionFailure ex) {
877 // quiet error recovery
878 flags_field |= (PUBLIC|STATIC);
879 this.type = new ErrorType(this, Type.noType);
880 throw ex;
881 }
882 }
884 public List<Type> getInterfaces() {
885 complete();
886 if (type instanceof ClassType) {
887 ClassType t = (ClassType)type;
888 if (t.interfaces_field == null) // FIXME: shouldn't be null
889 t.interfaces_field = List.nil();
890 if (t.all_interfaces_field != null)
891 return Type.getModelTypes(t.all_interfaces_field);
892 return t.interfaces_field;
893 } else {
894 return List.nil();
895 }
896 }
898 public Type getSuperclass() {
899 complete();
900 if (type instanceof ClassType) {
901 ClassType t = (ClassType)type;
902 if (t.supertype_field == null) // FIXME: shouldn't be null
903 t.supertype_field = Type.noType;
904 // An interface has no superclass; its supertype is Object.
905 return t.isInterface()
906 ? Type.noType
907 : t.supertype_field.getModelType();
908 } else {
909 return Type.noType;
910 }
911 }
913 public ElementKind getKind() {
914 long flags = flags();
915 if ((flags & ANNOTATION) != 0)
916 return ElementKind.ANNOTATION_TYPE;
917 else if ((flags & INTERFACE) != 0)
918 return ElementKind.INTERFACE;
919 else if ((flags & ENUM) != 0)
920 return ElementKind.ENUM;
921 else
922 return ElementKind.CLASS;
923 }
925 public NestingKind getNestingKind() {
926 complete();
927 if (owner.kind == PCK)
928 return NestingKind.TOP_LEVEL;
929 else if (name.isEmpty())
930 return NestingKind.ANONYMOUS;
931 else if (owner.kind == MTH)
932 return NestingKind.LOCAL;
933 else
934 return NestingKind.MEMBER;
935 }
937 /**
938 * @deprecated this method should never be used by javac internally.
939 */
940 @Override @Deprecated
941 public <A extends java.lang.annotation.Annotation> A getAnnotation(Class<A> annoType) {
942 return JavacElements.getAnnotation(this, annoType);
943 }
945 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
946 return v.visitType(this, p);
947 }
949 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
950 return v.visitClassSymbol(this, p);
951 }
952 }
955 /** A class for variable symbols
956 */
957 public static class VarSymbol extends Symbol implements VariableElement {
959 /** The variable's declaration position.
960 */
961 public int pos = Position.NOPOS;
963 /** The variable's address. Used for different purposes during
964 * flow analysis, translation and code generation.
965 * Flow analysis:
966 * If this is a blank final or local variable, its sequence number.
967 * Translation:
968 * If this is a private field, its access number.
969 * Code generation:
970 * If this is a local variable, its logical slot number.
971 */
972 public int adr = -1;
974 /** Construct a variable symbol, given its flags, name, type and owner.
975 */
976 public VarSymbol(long flags, Name name, Type type, Symbol owner) {
977 super(VAR, flags, name, type, owner);
978 }
980 /** Clone this symbol with new owner.
981 */
982 public VarSymbol clone(Symbol newOwner) {
983 VarSymbol v = new VarSymbol(flags_field, name, type, newOwner) {
984 @Override
985 public Symbol baseSymbol() {
986 return VarSymbol.this;
987 }
988 };
989 v.pos = pos;
990 v.adr = adr;
991 v.data = data;
992 // System.out.println("clone " + v + " in " + newOwner);//DEBUG
993 return v;
994 }
996 public String toString() {
997 return name.toString();
998 }
1000 public Symbol asMemberOf(Type site, Types types) {
1001 return new VarSymbol(flags_field, name, types.memberType(site, this), owner);
1002 }
1004 public ElementKind getKind() {
1005 long flags = flags();
1006 if ((flags & PARAMETER) != 0) {
1007 if (isExceptionParameter())
1008 return ElementKind.EXCEPTION_PARAMETER;
1009 else
1010 return ElementKind.PARAMETER;
1011 } else if ((flags & ENUM) != 0) {
1012 return ElementKind.ENUM_CONSTANT;
1013 } else if (owner.kind == TYP || owner.kind == ERR) {
1014 return ElementKind.FIELD;
1015 } else if (isResourceVariable()) {
1016 return ElementKind.RESOURCE_VARIABLE;
1017 } else {
1018 return ElementKind.LOCAL_VARIABLE;
1019 }
1020 }
1022 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
1023 return v.visitVariable(this, p);
1024 }
1026 public Object getConstantValue() { // Mirror API
1027 return Constants.decode(getConstValue(), type);
1028 }
1030 public void setLazyConstValue(final Env<AttrContext> env,
1031 final Attr attr,
1032 final JCTree.JCExpression initializer)
1033 {
1034 setData(new Callable<Object>() {
1035 public Object call() {
1036 return attr.attribLazyConstantValue(env, initializer, type);
1037 }
1038 });
1039 }
1041 /**
1042 * The variable's constant value, if this is a constant.
1043 * Before the constant value is evaluated, it points to an
1044 * initalizer environment. If this is not a constant, it can
1045 * be used for other stuff.
1046 */
1047 private Object data;
1049 public boolean isExceptionParameter() {
1050 return data == ElementKind.EXCEPTION_PARAMETER;
1051 }
1053 public boolean isResourceVariable() {
1054 return data == ElementKind.RESOURCE_VARIABLE;
1055 }
1057 public Object getConstValue() {
1058 // TODO: Consider if getConstValue and getConstantValue can be collapsed
1059 if (data == ElementKind.EXCEPTION_PARAMETER ||
1060 data == ElementKind.RESOURCE_VARIABLE) {
1061 return null;
1062 } else if (data instanceof Callable<?>) {
1063 // In this case, this is a final variable, with an as
1064 // yet unevaluated initializer.
1065 Callable<?> eval = (Callable<?>)data;
1066 data = null; // to make sure we don't evaluate this twice.
1067 try {
1068 data = eval.call();
1069 } catch (Exception ex) {
1070 throw new AssertionError(ex);
1071 }
1072 }
1073 return data;
1074 }
1076 public void setData(Object data) {
1077 Assert.check(!(data instanceof Env<?>), this);
1078 this.data = data;
1079 }
1081 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
1082 return v.visitVarSymbol(this, p);
1083 }
1084 }
1086 /** A class for method symbols.
1087 */
1088 public static class MethodSymbol extends Symbol implements ExecutableElement {
1090 /** The code of the method. */
1091 public Code code = null;
1093 /** The extra (synthetic/mandated) parameters of the method. */
1094 public List<VarSymbol> extraParams = List.nil();
1096 /** The parameters of the method. */
1097 public List<VarSymbol> params = null;
1099 /** The names of the parameters */
1100 public List<Name> savedParameterNames;
1102 /** For an attribute field accessor, its default value if any.
1103 * The value is null if none appeared in the method
1104 * declaration.
1105 */
1106 public Attribute defaultValue = null;
1108 /** Construct a method symbol, given its flags, name, type and owner.
1109 */
1110 public MethodSymbol(long flags, Name name, Type type, Symbol owner) {
1111 super(MTH, flags, name, type, owner);
1112 if (owner.type.hasTag(TYPEVAR)) Assert.error(owner + "." + name);
1113 }
1115 /** Clone this symbol with new owner.
1116 */
1117 public MethodSymbol clone(Symbol newOwner) {
1118 MethodSymbol m = new MethodSymbol(flags_field, name, type, newOwner) {
1119 @Override
1120 public Symbol baseSymbol() {
1121 return MethodSymbol.this;
1122 }
1123 };
1124 m.code = code;
1125 return m;
1126 }
1128 /** The Java source which this symbol represents.
1129 */
1130 public String toString() {
1131 if ((flags() & BLOCK) != 0) {
1132 return owner.name.toString();
1133 } else {
1134 String s = (name == name.table.names.init)
1135 ? owner.name.toString()
1136 : name.toString();
1137 if (type != null) {
1138 if (type.hasTag(FORALL))
1139 s = "<" + ((ForAll)type).getTypeArguments() + ">" + s;
1140 s += "(" + type.argtypes((flags() & VARARGS) != 0) + ")";
1141 }
1142 return s;
1143 }
1144 }
1146 public boolean isDynamic() {
1147 return false;
1148 }
1150 /** find a symbol that this (proxy method) symbol implements.
1151 * @param c The class whose members are searched for
1152 * implementations
1153 */
1154 public Symbol implemented(TypeSymbol c, Types types) {
1155 Symbol impl = null;
1156 for (List<Type> is = types.interfaces(c.type);
1157 impl == null && is.nonEmpty();
1158 is = is.tail) {
1159 TypeSymbol i = is.head.tsym;
1160 impl = implementedIn(i, types);
1161 if (impl == null)
1162 impl = implemented(i, types);
1163 }
1164 return impl;
1165 }
1167 public Symbol implementedIn(TypeSymbol c, Types types) {
1168 Symbol impl = null;
1169 for (Scope.Entry e = c.members().lookup(name);
1170 impl == null && e.scope != null;
1171 e = e.next()) {
1172 if (this.overrides(e.sym, (TypeSymbol)owner, types, true) &&
1173 // FIXME: I suspect the following requires a
1174 // subst() for a parametric return type.
1175 types.isSameType(type.getReturnType(),
1176 types.memberType(owner.type, e.sym).getReturnType())) {
1177 impl = e.sym;
1178 }
1179 }
1180 return impl;
1181 }
1183 /** Will the erasure of this method be considered by the VM to
1184 * override the erasure of the other when seen from class `origin'?
1185 */
1186 public boolean binaryOverrides(Symbol _other, TypeSymbol origin, Types types) {
1187 if (isConstructor() || _other.kind != MTH) return false;
1189 if (this == _other) return true;
1190 MethodSymbol other = (MethodSymbol)_other;
1192 // check for a direct implementation
1193 if (other.isOverridableIn((TypeSymbol)owner) &&
1194 types.asSuper(owner.type, other.owner) != null &&
1195 types.isSameType(erasure(types), other.erasure(types)))
1196 return true;
1198 // check for an inherited implementation
1199 return
1200 (flags() & ABSTRACT) == 0 &&
1201 other.isOverridableIn(origin) &&
1202 this.isMemberOf(origin, types) &&
1203 types.isSameType(erasure(types), other.erasure(types));
1204 }
1206 /** The implementation of this (abstract) symbol in class origin,
1207 * from the VM's point of view, null if method does not have an
1208 * implementation in class.
1209 * @param origin The class of which the implementation is a member.
1210 */
1211 public MethodSymbol binaryImplementation(ClassSymbol origin, Types types) {
1212 for (TypeSymbol c = origin; c != null; c = types.supertype(c.type).tsym) {
1213 for (Scope.Entry e = c.members().lookup(name);
1214 e.scope != null;
1215 e = e.next()) {
1216 if (e.sym.kind == MTH &&
1217 ((MethodSymbol)e.sym).binaryOverrides(this, origin, types))
1218 return (MethodSymbol)e.sym;
1219 }
1220 }
1221 return null;
1222 }
1224 /** Does this symbol override `other' symbol, when both are seen as
1225 * members of class `origin'? It is assumed that _other is a member
1226 * of origin.
1227 *
1228 * It is assumed that both symbols have the same name. The static
1229 * modifier is ignored for this test.
1230 *
1231 * See JLS 8.4.6.1 (without transitivity) and 8.4.6.4
1232 */
1233 public boolean overrides(Symbol _other, TypeSymbol origin, Types types, boolean checkResult) {
1234 if (isConstructor() || _other.kind != MTH) return false;
1236 if (this == _other) return true;
1237 MethodSymbol other = (MethodSymbol)_other;
1239 // check for a direct implementation
1240 if (other.isOverridableIn((TypeSymbol)owner) &&
1241 types.asSuper(owner.type, other.owner) != null) {
1242 Type mt = types.memberType(owner.type, this);
1243 Type ot = types.memberType(owner.type, other);
1244 if (types.isSubSignature(mt, ot)) {
1245 if (!checkResult)
1246 return true;
1247 if (types.returnTypeSubstitutable(mt, ot))
1248 return true;
1249 }
1250 }
1252 // check for an inherited implementation
1253 if ((flags() & ABSTRACT) != 0 ||
1254 ((other.flags() & ABSTRACT) == 0 && (other.flags() & DEFAULT) == 0) ||
1255 !other.isOverridableIn(origin) ||
1256 !this.isMemberOf(origin, types))
1257 return false;
1259 // assert types.asSuper(origin.type, other.owner) != null;
1260 Type mt = types.memberType(origin.type, this);
1261 Type ot = types.memberType(origin.type, other);
1262 return
1263 types.isSubSignature(mt, ot) &&
1264 (!checkResult || types.resultSubtype(mt, ot, types.noWarnings));
1265 }
1267 private boolean isOverridableIn(TypeSymbol origin) {
1268 // JLS 8.4.6.1
1269 switch ((int)(flags_field & Flags.AccessFlags)) {
1270 case Flags.PRIVATE:
1271 return false;
1272 case Flags.PUBLIC:
1273 return !this.owner.isInterface() ||
1274 (flags_field & STATIC) == 0;
1275 case Flags.PROTECTED:
1276 return (origin.flags() & INTERFACE) == 0;
1277 case 0:
1278 // for package private: can only override in the same
1279 // package
1280 return
1281 this.packge() == origin.packge() &&
1282 (origin.flags() & INTERFACE) == 0;
1283 default:
1284 return false;
1285 }
1286 }
1288 @Override
1289 public boolean isInheritedIn(Symbol clazz, Types types) {
1290 switch ((int)(flags_field & Flags.AccessFlags)) {
1291 case PUBLIC:
1292 return !this.owner.isInterface() ||
1293 clazz == owner ||
1294 (flags_field & STATIC) == 0;
1295 default:
1296 return super.isInheritedIn(clazz, types);
1297 }
1298 }
1300 /** The implementation of this (abstract) symbol in class origin;
1301 * null if none exists. Synthetic methods are not considered
1302 * as possible implementations.
1303 */
1304 public MethodSymbol implementation(TypeSymbol origin, Types types, boolean checkResult) {
1305 return implementation(origin, types, checkResult, implementation_filter);
1306 }
1307 // where
1308 public static final Filter<Symbol> implementation_filter = new Filter<Symbol>() {
1309 public boolean accepts(Symbol s) {
1310 return s.kind == Kinds.MTH &&
1311 (s.flags() & SYNTHETIC) == 0;
1312 }
1313 };
1315 public MethodSymbol implementation(TypeSymbol origin, Types types, boolean checkResult, Filter<Symbol> implFilter) {
1316 MethodSymbol res = types.implementation(this, origin, checkResult, implFilter);
1317 if (res != null)
1318 return res;
1319 // if origin is derived from a raw type, we might have missed
1320 // an implementation because we do not know enough about instantiations.
1321 // in this case continue with the supertype as origin.
1322 if (types.isDerivedRaw(origin.type) && !origin.isInterface())
1323 return implementation(types.supertype(origin.type).tsym, types, checkResult);
1324 else
1325 return null;
1326 }
1328 public List<VarSymbol> params() {
1329 owner.complete();
1330 if (params == null) {
1331 // If ClassReader.saveParameterNames has been set true, then
1332 // savedParameterNames will be set to a list of names that
1333 // matches the types in type.getParameterTypes(). If any names
1334 // were not found in the class file, those names in the list will
1335 // be set to the empty name.
1336 // If ClassReader.saveParameterNames has been set false, then
1337 // savedParameterNames will be null.
1338 List<Name> paramNames = savedParameterNames;
1339 savedParameterNames = null;
1340 // discard the provided names if the list of names is the wrong size.
1341 if (paramNames == null || paramNames.size() != type.getParameterTypes().size()) {
1342 paramNames = List.nil();
1343 }
1344 ListBuffer<VarSymbol> buf = new ListBuffer<VarSymbol>();
1345 List<Name> remaining = paramNames;
1346 // assert: remaining and paramNames are both empty or both
1347 // have same cardinality as type.getParameterTypes()
1348 int i = 0;
1349 for (Type t : type.getParameterTypes()) {
1350 Name paramName;
1351 if (remaining.isEmpty()) {
1352 // no names for any parameters available
1353 paramName = createArgName(i, paramNames);
1354 } else {
1355 paramName = remaining.head;
1356 remaining = remaining.tail;
1357 if (paramName.isEmpty()) {
1358 // no name for this specific parameter
1359 paramName = createArgName(i, paramNames);
1360 }
1361 }
1362 buf.append(new VarSymbol(PARAMETER, paramName, t, this));
1363 i++;
1364 }
1365 params = buf.toList();
1366 }
1367 return params;
1368 }
1370 // Create a name for the argument at position 'index' that is not in
1371 // the exclude list. In normal use, either no names will have been
1372 // provided, in which case the exclude list is empty, or all the names
1373 // will have been provided, in which case this method will not be called.
1374 private Name createArgName(int index, List<Name> exclude) {
1375 String prefix = "arg";
1376 while (true) {
1377 Name argName = name.table.fromString(prefix + index);
1378 if (!exclude.contains(argName))
1379 return argName;
1380 prefix += "$";
1381 }
1382 }
1384 public Symbol asMemberOf(Type site, Types types) {
1385 return new MethodSymbol(flags_field, name, types.memberType(site, this), owner);
1386 }
1388 public ElementKind getKind() {
1389 if (name == name.table.names.init)
1390 return ElementKind.CONSTRUCTOR;
1391 else if (name == name.table.names.clinit)
1392 return ElementKind.STATIC_INIT;
1393 else if ((flags() & BLOCK) != 0)
1394 return isStatic() ? ElementKind.STATIC_INIT : ElementKind.INSTANCE_INIT;
1395 else
1396 return ElementKind.METHOD;
1397 }
1399 public boolean isStaticOrInstanceInit() {
1400 return getKind() == ElementKind.STATIC_INIT ||
1401 getKind() == ElementKind.INSTANCE_INIT;
1402 }
1404 /**
1405 * A polymorphic signature method (JLS SE 7, 8.4.1) is a method that
1406 * (i) is declared in the java.lang.invoke.MethodHandle class, (ii) takes
1407 * a single variable arity parameter (iii) whose declared type is Object[],
1408 * (iv) has a return type of Object and (v) is native.
1409 */
1410 public boolean isSignaturePolymorphic(Types types) {
1411 List<Type> argtypes = type.getParameterTypes();
1412 Type firstElemType = argtypes.nonEmpty() ?
1413 types.elemtype(argtypes.head) :
1414 null;
1415 return owner == types.syms.methodHandleType.tsym &&
1416 argtypes.length() == 1 &&
1417 firstElemType != null &&
1418 types.isSameType(firstElemType, types.syms.objectType) &&
1419 types.isSameType(type.getReturnType(), types.syms.objectType) &&
1420 (flags() & NATIVE) != 0;
1421 }
1423 public Attribute getDefaultValue() {
1424 return defaultValue;
1425 }
1427 public List<VarSymbol> getParameters() {
1428 return params();
1429 }
1431 public boolean isVarArgs() {
1432 return (flags() & VARARGS) != 0;
1433 }
1435 public boolean isDefault() {
1436 return (flags() & DEFAULT) != 0;
1437 }
1439 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
1440 return v.visitExecutable(this, p);
1441 }
1443 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
1444 return v.visitMethodSymbol(this, p);
1445 }
1447 public Type getReturnType() {
1448 return asType().getReturnType();
1449 }
1451 public List<Type> getThrownTypes() {
1452 return asType().getThrownTypes();
1453 }
1454 }
1456 /** A class for invokedynamic method calls.
1457 */
1458 public static class DynamicMethodSymbol extends MethodSymbol {
1460 public Object[] staticArgs;
1461 public Symbol bsm;
1462 public int bsmKind;
1464 public DynamicMethodSymbol(Name name, Symbol owner, int bsmKind, MethodSymbol bsm, Type type, Object[] staticArgs) {
1465 super(0, name, type, owner);
1466 this.bsm = bsm;
1467 this.bsmKind = bsmKind;
1468 this.staticArgs = staticArgs;
1469 }
1471 @Override
1472 public boolean isDynamic() {
1473 return true;
1474 }
1475 }
1477 /** A class for predefined operators.
1478 */
1479 public static class OperatorSymbol extends MethodSymbol {
1481 public int opcode;
1483 public OperatorSymbol(Name name, Type type, int opcode, Symbol owner) {
1484 super(PUBLIC | STATIC, name, type, owner);
1485 this.opcode = opcode;
1486 }
1488 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
1489 return v.visitOperatorSymbol(this, p);
1490 }
1491 }
1493 /** Symbol completer interface.
1494 */
1495 public static interface Completer {
1496 void complete(Symbol sym) throws CompletionFailure;
1497 }
1499 public static class CompletionFailure extends RuntimeException {
1500 private static final long serialVersionUID = 0;
1501 public Symbol sym;
1503 /** A diagnostic object describing the failure
1504 */
1505 public JCDiagnostic diag;
1507 /** A localized string describing the failure.
1508 * @deprecated Use {@code getDetail()} or {@code getMessage()}
1509 */
1510 @Deprecated
1511 public String errmsg;
1513 public CompletionFailure(Symbol sym, String errmsg) {
1514 this.sym = sym;
1515 this.errmsg = errmsg;
1516 // this.printStackTrace();//DEBUG
1517 }
1519 public CompletionFailure(Symbol sym, JCDiagnostic diag) {
1520 this.sym = sym;
1521 this.diag = diag;
1522 // this.printStackTrace();//DEBUG
1523 }
1525 public JCDiagnostic getDiagnostic() {
1526 return diag;
1527 }
1529 @Override
1530 public String getMessage() {
1531 if (diag != null)
1532 return diag.getMessage(null);
1533 else
1534 return errmsg;
1535 }
1537 public Object getDetailValue() {
1538 return (diag != null ? diag : errmsg);
1539 }
1541 @Override
1542 public CompletionFailure initCause(Throwable cause) {
1543 super.initCause(cause);
1544 return this;
1545 }
1547 }
1549 /**
1550 * A visitor for symbols. A visitor is used to implement operations
1551 * (or relations) on symbols. Most common operations on types are
1552 * binary relations and this interface is designed for binary
1553 * relations, that is, operations on the form
1554 * Symbol × P → R.
1555 * <!-- In plain text: Type x P -> R -->
1556 *
1557 * @param <R> the return type of the operation implemented by this
1558 * visitor; use Void if no return type is needed.
1559 * @param <P> the type of the second argument (the first being the
1560 * symbol itself) of the operation implemented by this visitor; use
1561 * Void if a second argument is not needed.
1562 */
1563 public interface Visitor<R,P> {
1564 R visitClassSymbol(ClassSymbol s, P arg);
1565 R visitMethodSymbol(MethodSymbol s, P arg);
1566 R visitPackageSymbol(PackageSymbol s, P arg);
1567 R visitOperatorSymbol(OperatorSymbol s, P arg);
1568 R visitVarSymbol(VarSymbol s, P arg);
1569 R visitTypeSymbol(TypeSymbol s, P arg);
1570 R visitSymbol(Symbol s, P arg);
1571 }
1572 }