Thu, 02 Sep 2010 23:10:05 +0530
6458749: TypeParameterElement.getEnclosedElements throws NPE within javac.
Reviewed-by: jjg
1 /*
2 * Copyright (c) 1999, 2008, 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;
30 import javax.lang.model.element.*;
31 import javax.tools.JavaFileObject;
33 import com.sun.tools.javac.util.*;
34 import com.sun.tools.javac.util.Name;
35 import com.sun.tools.javac.code.Type.*;
36 import com.sun.tools.javac.comp.Attr;
37 import com.sun.tools.javac.comp.AttrContext;
38 import com.sun.tools.javac.comp.Env;
39 import com.sun.tools.javac.jvm.*;
40 import com.sun.tools.javac.model.*;
41 import com.sun.tools.javac.tree.JCTree;
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.TypeTags.*;
47 /** Root class for Java symbols. It contains subclasses
48 * for specific sorts of symbols, such as variables, methods and operators,
49 * types, packages. Each subclass is represented as a static inner class
50 * inside Symbol.
51 *
52 * <p><b>This is NOT part of any supported API.
53 * If you write code that depends on this, you do so at your own risk.
54 * This code and its internal interfaces are subject to change or
55 * deletion without notice.</b>
56 */
57 public abstract class Symbol implements Element {
58 // public Throwable debug = new Throwable();
60 /** The kind of this symbol.
61 * @see Kinds
62 */
63 public int kind;
65 /** The flags of this symbol.
66 */
67 public long flags_field;
69 /** An accessor method for the flags of this symbol.
70 * Flags of class symbols should be accessed through the accessor
71 * method to make sure that the class symbol is loaded.
72 */
73 public long flags() { return flags_field; }
75 /** The attributes of this symbol.
76 */
77 public List<Attribute.Compound> attributes_field;
79 /** An accessor method for the attributes of this symbol.
80 * Attributes of class symbols should be accessed through the accessor
81 * method to make sure that the class symbol is loaded.
82 */
83 public List<Attribute.Compound> getAnnotationMirrors() {
84 assert attributes_field != null;
85 return attributes_field;
86 }
88 /** Fetch a particular annotation from a symbol. */
89 public Attribute.Compound attribute(Symbol anno) {
90 for (Attribute.Compound a : getAnnotationMirrors())
91 if (a.type.tsym == anno) return a;
92 return null;
93 }
95 /** The name of this symbol in Utf8 representation.
96 */
97 public Name name;
99 /** The type of this symbol.
100 */
101 public Type type;
103 /** The type annotations targeted to a tree directly owned by this symbol
104 */
105 // type annotations are stored here for two purposes:
106 // - convenient location to store annotations for generation after erasure
107 // - a private interface for accessing type annotations parsed from
108 // classfiles
109 // the field is populated for the following declaration only
110 // class, field, variable and type parameters
111 //
112 public List<Attribute.TypeCompound> typeAnnotations;
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.attributes_field = List.nil();
136 this.typeAnnotations = List.nil();
137 this.name = name;
138 }
140 /** Clone this symbol with new owner.
141 * Legal only for fields and methods.
142 */
143 public Symbol clone(Symbol newOwner) {
144 throw new AssertionError();
145 }
147 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
148 return v.visitSymbol(this, p);
149 }
151 /** The Java source which this symbol represents.
152 * A description of this symbol; overrides Object.
153 */
154 public String toString() {
155 return name.toString();
156 }
158 /** A Java source description of the location of this symbol; used for
159 * error reporting.
160 *
161 * @return null if the symbol is a package or a toplevel class defined in
162 * the default package; otherwise, the owner symbol is returned
163 */
164 public Symbol location() {
165 if (owner.name == null || (owner.name.isEmpty() && owner.kind != PCK && owner.kind != TYP)) {
166 return null;
167 }
168 return owner;
169 }
171 public Symbol location(Type site, Types types) {
172 if (owner.name == null || owner.name.isEmpty()) {
173 return location();
174 }
175 if (owner.type.tag == CLASS) {
176 Type ownertype = types.asOuterSuper(site, owner);
177 if (ownertype != null) return ownertype.tsym;
178 }
179 return owner;
180 }
182 /** The symbol's erased type.
183 */
184 public Type erasure(Types types) {
185 if (erasure_field == null)
186 erasure_field = types.erasure(type);
187 return erasure_field;
188 }
190 /** The external type of a symbol. This is the symbol's erased type
191 * except for constructors of inner classes which get the enclosing
192 * instance class added as first argument.
193 */
194 public Type externalType(Types types) {
195 Type t = erasure(types);
196 if (name == name.table.names.init && owner.hasOuterInstance()) {
197 Type outerThisType = types.erasure(owner.type.getEnclosingType());
198 return new MethodType(t.getParameterTypes().prepend(outerThisType),
199 t.getReturnType(),
200 t.getThrownTypes(),
201 t.tsym);
202 } else {
203 return t;
204 }
205 }
207 public boolean isStatic() {
208 return
209 (flags() & STATIC) != 0 ||
210 (owner.flags() & INTERFACE) != 0 && kind != MTH;
211 }
213 public boolean isInterface() {
214 return (flags() & INTERFACE) != 0;
215 }
217 /** Is this symbol declared (directly or indirectly) local
218 * to a method or variable initializer?
219 * Also includes fields of inner classes which are in
220 * turn local to a method or variable initializer.
221 */
222 public boolean isLocal() {
223 return
224 (owner.kind & (VAR | MTH)) != 0 ||
225 (owner.kind == TYP && owner.isLocal());
226 }
228 /** Has this symbol an empty name? This includes anonymous
229 * inner classses.
230 */
231 public boolean isAnonymous() {
232 return name.isEmpty();
233 }
235 /** Is this symbol a constructor?
236 */
237 public boolean isConstructor() {
238 return name == name.table.names.init;
239 }
241 /** The fully qualified name of this symbol.
242 * This is the same as the symbol's name except for class symbols,
243 * which are handled separately.
244 */
245 public Name getQualifiedName() {
246 return name;
247 }
249 /** The fully qualified name of this symbol after converting to flat
250 * representation. This is the same as the symbol's name except for
251 * class symbols, which are handled separately.
252 */
253 public Name flatName() {
254 return getQualifiedName();
255 }
257 /** If this is a class or package, its members, otherwise null.
258 */
259 public Scope members() {
260 return null;
261 }
263 /** A class is an inner class if it it has an enclosing instance class.
264 */
265 public boolean isInner() {
266 return type.getEnclosingType().tag == CLASS;
267 }
269 /** An inner class has an outer instance if it is not an interface
270 * it has an enclosing instance class which might be referenced from the class.
271 * Nested classes can see instance members of their enclosing class.
272 * Their constructors carry an additional this$n parameter, inserted
273 * implicitly by the compiler.
274 *
275 * @see #isInner
276 */
277 public boolean hasOuterInstance() {
278 return
279 type.getEnclosingType().tag == CLASS && (flags() & (INTERFACE | NOOUTERTHIS)) == 0;
280 }
282 /** The closest enclosing class of this symbol's declaration.
283 */
284 public ClassSymbol enclClass() {
285 Symbol c = this;
286 while (c != null &&
287 ((c.kind & TYP) == 0 || c.type.tag != CLASS)) {
288 c = c.owner;
289 }
290 return (ClassSymbol)c;
291 }
293 /** The outermost class which indirectly owns this symbol.
294 */
295 public ClassSymbol outermostClass() {
296 Symbol sym = this;
297 Symbol prev = null;
298 while (sym.kind != PCK) {
299 prev = sym;
300 sym = sym.owner;
301 }
302 return (ClassSymbol) prev;
303 }
305 /** The package which indirectly owns this symbol.
306 */
307 public PackageSymbol packge() {
308 Symbol sym = this;
309 while (sym.kind != PCK) {
310 sym = sym.owner;
311 }
312 return (PackageSymbol) sym;
313 }
315 /** Is this symbol a subclass of `base'? Only defined for ClassSymbols.
316 */
317 public boolean isSubClass(Symbol base, Types types) {
318 throw new AssertionError("isSubClass " + this);
319 }
321 /** Fully check membership: hierarchy, protection, and hiding.
322 * Does not exclude methods not inherited due to overriding.
323 */
324 public boolean isMemberOf(TypeSymbol clazz, Types types) {
325 return
326 owner == clazz ||
327 clazz.isSubClass(owner, types) &&
328 isInheritedIn(clazz, types) &&
329 !hiddenIn((ClassSymbol)clazz, types);
330 }
332 /** Is this symbol the same as or enclosed by the given class? */
333 public boolean isEnclosedBy(ClassSymbol clazz) {
334 for (Symbol sym = this; sym.kind != PCK; sym = sym.owner)
335 if (sym == clazz) return true;
336 return false;
337 }
339 /** Check for hiding. Note that this doesn't handle multiple
340 * (interface) inheritance. */
341 private boolean hiddenIn(ClassSymbol clazz, Types types) {
342 if (kind == MTH && (flags() & STATIC) == 0) return false;
343 while (true) {
344 if (owner == clazz) return false;
345 Scope.Entry e = clazz.members().lookup(name);
346 while (e.scope != null) {
347 if (e.sym == this) return false;
348 if (e.sym.kind == kind &&
349 (kind != MTH ||
350 (e.sym.flags() & STATIC) != 0 &&
351 types.isSubSignature(e.sym.type, type)))
352 return true;
353 e = e.next();
354 }
355 Type superType = types.supertype(clazz.type);
356 if (superType.tag != TypeTags.CLASS) return false;
357 clazz = (ClassSymbol)superType.tsym;
358 }
359 }
361 /** Is this symbol inherited into a given class?
362 * PRE: If symbol's owner is a interface,
363 * it is already assumed that the interface is a superinterface
364 * of given class.
365 * @param clazz The class for which we want to establish membership.
366 * This must be a subclass of the member's owner.
367 */
368 public boolean isInheritedIn(Symbol clazz, Types types) {
369 switch ((int)(flags_field & Flags.AccessFlags)) {
370 default: // error recovery
371 case PUBLIC:
372 return true;
373 case PRIVATE:
374 return this.owner == clazz;
375 case PROTECTED:
376 // we model interfaces as extending Object
377 return (clazz.flags() & INTERFACE) == 0;
378 case 0:
379 PackageSymbol thisPackage = this.packge();
380 for (Symbol sup = clazz;
381 sup != null && sup != this.owner;
382 sup = types.supertype(sup.type).tsym) {
383 while (sup.type.tag == TYPEVAR)
384 sup = sup.type.getUpperBound().tsym;
385 if (sup.type.isErroneous())
386 return true; // error recovery
387 if ((sup.flags() & COMPOUND) != 0)
388 continue;
389 if (sup.packge() != thisPackage)
390 return false;
391 }
392 return (clazz.flags() & INTERFACE) == 0;
393 }
394 }
396 /** The (variable or method) symbol seen as a member of given
397 * class type`site' (this might change the symbol's type).
398 * This is used exclusively for producing diagnostics.
399 */
400 public Symbol asMemberOf(Type site, Types types) {
401 throw new AssertionError();
402 }
404 /** Does this method symbol override `other' symbol, when both are seen as
405 * members of class `origin'? It is assumed that _other is a member
406 * of origin.
407 *
408 * It is assumed that both symbols have the same name. The static
409 * modifier is ignored for this test.
410 *
411 * See JLS 8.4.6.1 (without transitivity) and 8.4.6.4
412 */
413 public boolean overrides(Symbol _other, TypeSymbol origin, Types types, boolean checkResult) {
414 return false;
415 }
417 /** Complete the elaboration of this symbol's definition.
418 */
419 public void complete() throws CompletionFailure {
420 if (completer != null) {
421 Completer c = completer;
422 completer = null;
423 c.complete(this);
424 }
425 }
427 /** True if the symbol represents an entity that exists.
428 */
429 public boolean exists() {
430 return true;
431 }
433 public Type asType() {
434 return type;
435 }
437 public Symbol getEnclosingElement() {
438 return owner;
439 }
441 public ElementKind getKind() {
442 return ElementKind.OTHER; // most unkind
443 }
445 public Set<Modifier> getModifiers() {
446 return Flags.asModifierSet(flags());
447 }
449 public Name getSimpleName() {
450 return name;
451 }
453 /**
454 * @deprecated this method should never be used by javac internally.
455 */
456 @Deprecated
457 public <A extends java.lang.annotation.Annotation> A getAnnotation(Class<A> annoType) {
458 return JavacElements.getAnnotation(this, annoType);
459 }
461 // TODO: getEnclosedElements should return a javac List, fix in FilteredMemberList
462 public java.util.List<Symbol> getEnclosedElements() {
463 return List.nil();
464 }
466 public List<TypeSymbol> getTypeParameters() {
467 ListBuffer<TypeSymbol> l = ListBuffer.lb();
468 for (Type t : type.getTypeArguments()) {
469 l.append(t.tsym);
470 }
471 return l.toList();
472 }
474 public static class DelegatedSymbol extends Symbol {
475 protected Symbol other;
476 public DelegatedSymbol(Symbol other) {
477 super(other.kind, other.flags_field, other.name, other.type, other.owner);
478 this.other = other;
479 }
480 public String toString() { return other.toString(); }
481 public Symbol location() { return other.location(); }
482 public Symbol location(Type site, Types types) { return other.location(site, types); }
483 public Type erasure(Types types) { return other.erasure(types); }
484 public Type externalType(Types types) { return other.externalType(types); }
485 public boolean isLocal() { return other.isLocal(); }
486 public boolean isConstructor() { return other.isConstructor(); }
487 public Name getQualifiedName() { return other.getQualifiedName(); }
488 public Name flatName() { return other.flatName(); }
489 public Scope members() { return other.members(); }
490 public boolean isInner() { return other.isInner(); }
491 public boolean hasOuterInstance() { return other.hasOuterInstance(); }
492 public ClassSymbol enclClass() { return other.enclClass(); }
493 public ClassSymbol outermostClass() { return other.outermostClass(); }
494 public PackageSymbol packge() { return other.packge(); }
495 public boolean isSubClass(Symbol base, Types types) { return other.isSubClass(base, types); }
496 public boolean isMemberOf(TypeSymbol clazz, Types types) { return other.isMemberOf(clazz, types); }
497 public boolean isEnclosedBy(ClassSymbol clazz) { return other.isEnclosedBy(clazz); }
498 public boolean isInheritedIn(Symbol clazz, Types types) { return other.isInheritedIn(clazz, types); }
499 public Symbol asMemberOf(Type site, Types types) { return other.asMemberOf(site, types); }
500 public void complete() throws CompletionFailure { other.complete(); }
502 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
503 return other.accept(v, p);
504 }
506 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
507 return v.visitSymbol(other, p);
508 }
509 }
511 /** A class for type symbols. Type variables are represented by instances
512 * of this class, classes and packages by instances of subclasses.
513 */
514 public static class TypeSymbol
515 extends Symbol implements TypeParameterElement {
516 // Implements TypeParameterElement because type parameters don't
517 // have their own TypeSymbol subclass.
518 // TODO: type parameters should have their own TypeSymbol subclass
520 public TypeSymbol(long flags, Name name, Type type, Symbol owner) {
521 super(TYP, flags, name, type, owner);
522 }
524 /** form a fully qualified name from a name and an owner
525 */
526 static public Name formFullName(Name name, Symbol owner) {
527 if (owner == null) return name;
528 if (((owner.kind != ERR)) &&
529 ((owner.kind & (VAR | MTH)) != 0
530 || (owner.kind == TYP && owner.type.tag == TYPEVAR)
531 )) return name;
532 Name prefix = owner.getQualifiedName();
533 if (prefix == null || prefix == prefix.table.names.empty)
534 return name;
535 else return prefix.append('.', name);
536 }
538 /** form a fully qualified name from a name and an owner, after
539 * converting to flat representation
540 */
541 static public Name formFlatName(Name name, Symbol owner) {
542 if (owner == null ||
543 (owner.kind & (VAR | MTH)) != 0
544 || (owner.kind == TYP && owner.type.tag == TYPEVAR)
545 ) return name;
546 char sep = owner.kind == TYP ? '$' : '.';
547 Name prefix = owner.flatName();
548 if (prefix == null || prefix == prefix.table.names.empty)
549 return name;
550 else return prefix.append(sep, name);
551 }
553 /**
554 * A total ordering between type symbols that refines the
555 * class inheritance graph.
556 *
557 * Typevariables always precede other kinds of symbols.
558 */
559 public final boolean precedes(TypeSymbol that, Types types) {
560 if (this == that)
561 return false;
562 if (this.type.tag == that.type.tag) {
563 if (this.type.tag == CLASS) {
564 return
565 types.rank(that.type) < types.rank(this.type) ||
566 types.rank(that.type) == types.rank(this.type) &&
567 that.getQualifiedName().compareTo(this.getQualifiedName()) < 0;
568 } else if (this.type.tag == TYPEVAR) {
569 return types.isSubtype(this.type, that.type);
570 }
571 }
572 return this.type.tag == TYPEVAR;
573 }
575 // For type params; overridden in subclasses.
576 public ElementKind getKind() {
577 return ElementKind.TYPE_PARAMETER;
578 }
580 public java.util.List<Symbol> getEnclosedElements() {
581 List<Symbol> list = List.nil();
582 if (kind == TYP && type.tag == TYPEVAR) {
583 return list;
584 }
585 for (Scope.Entry e = members().elems; e != null; e = e.sibling) {
586 if (e.sym != null && (e.sym.flags() & SYNTHETIC) == 0 && e.sym.owner == this)
587 list = list.prepend(e.sym);
588 }
589 return list;
590 }
592 // For type params.
593 // Perhaps not needed if getEnclosingElement can be spec'ed
594 // to do the same thing.
595 // TODO: getGenericElement() might not be needed
596 public Symbol getGenericElement() {
597 return owner;
598 }
600 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
601 assert type.tag == TYPEVAR; // else override will be invoked
602 return v.visitTypeParameter(this, p);
603 }
605 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
606 return v.visitTypeSymbol(this, p);
607 }
609 public List<Type> getBounds() {
610 TypeVar t = (TypeVar)type;
611 Type bound = t.getUpperBound();
612 if (!bound.isCompound())
613 return List.of(bound);
614 ClassType ct = (ClassType)bound;
615 if (!ct.tsym.erasure_field.isInterface()) {
616 return ct.interfaces_field.prepend(ct.supertype_field);
617 } else {
618 // No superclass was given in bounds.
619 // In this case, supertype is Object, erasure is first interface.
620 return ct.interfaces_field;
621 }
622 }
623 }
625 /** A class for package symbols
626 */
627 public static class PackageSymbol extends TypeSymbol
628 implements PackageElement {
630 public Scope members_field;
631 public Name fullname;
632 public ClassSymbol package_info; // see bug 6443073
634 public PackageSymbol(Name name, Type type, Symbol owner) {
635 super(0, name, type, owner);
636 this.kind = PCK;
637 this.members_field = null;
638 this.fullname = formFullName(name, owner);
639 }
641 public PackageSymbol(Name name, Symbol owner) {
642 this(name, null, owner);
643 this.type = new PackageType(this);
644 }
646 public String toString() {
647 return fullname.toString();
648 }
650 public Name getQualifiedName() {
651 return fullname;
652 }
654 public boolean isUnnamed() {
655 return name.isEmpty() && owner != null;
656 }
658 public Scope members() {
659 if (completer != null) complete();
660 return members_field;
661 }
663 public long flags() {
664 if (completer != null) complete();
665 return flags_field;
666 }
668 public List<Attribute.Compound> getAnnotationMirrors() {
669 if (completer != null) complete();
670 if (package_info != null && package_info.completer != null) {
671 package_info.complete();
672 if (attributes_field.isEmpty())
673 attributes_field = package_info.attributes_field;
674 }
675 assert attributes_field != null;
676 return attributes_field;
677 }
679 /** A package "exists" if a type or package that exists has
680 * been seen within it.
681 */
682 public boolean exists() {
683 return (flags_field & EXISTS) != 0;
684 }
686 public ElementKind getKind() {
687 return ElementKind.PACKAGE;
688 }
690 public Symbol getEnclosingElement() {
691 return null;
692 }
694 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
695 return v.visitPackage(this, p);
696 }
698 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
699 return v.visitPackageSymbol(this, p);
700 }
701 }
703 /** A class for class symbols
704 */
705 public static class ClassSymbol extends TypeSymbol implements TypeElement {
707 /** a scope for all class members; variables, methods and inner classes
708 * type parameters are not part of this scope
709 */
710 public Scope members_field;
712 /** the fully qualified name of the class, i.e. pck.outer.inner.
713 * null for anonymous classes
714 */
715 public Name fullname;
717 /** the fully qualified name of the class after converting to flat
718 * representation, i.e. pck.outer$inner,
719 * set externally for local and anonymous classes
720 */
721 public Name flatname;
723 /** the sourcefile where the class came from
724 */
725 public JavaFileObject sourcefile;
727 /** the classfile from where to load this class
728 * this will have extension .class or .java
729 */
730 public JavaFileObject classfile;
732 /** the constant pool of the class
733 */
734 public Pool pool;
736 public ClassSymbol(long flags, Name name, Type type, Symbol owner) {
737 super(flags, name, type, owner);
738 this.members_field = null;
739 this.fullname = formFullName(name, owner);
740 this.flatname = formFlatName(name, owner);
741 this.sourcefile = null;
742 this.classfile = null;
743 this.pool = null;
744 }
746 public ClassSymbol(long flags, Name name, Symbol owner) {
747 this(
748 flags,
749 name,
750 new ClassType(Type.noType, null, null),
751 owner);
752 this.type.tsym = this;
753 }
755 /** The Java source which this symbol represents.
756 */
757 public String toString() {
758 return className();
759 }
761 public long flags() {
762 if (completer != null) complete();
763 return flags_field;
764 }
766 public Scope members() {
767 if (completer != null) complete();
768 return members_field;
769 }
771 public List<Attribute.Compound> getAnnotationMirrors() {
772 if (completer != null) complete();
773 assert attributes_field != null;
774 return attributes_field;
775 }
777 public Type erasure(Types types) {
778 if (erasure_field == null)
779 erasure_field = new ClassType(types.erasure(type.getEnclosingType()),
780 List.<Type>nil(), this);
781 return erasure_field;
782 }
784 public String className() {
785 if (name.isEmpty())
786 return
787 Log.getLocalizedString("anonymous.class", flatname);
788 else
789 return fullname.toString();
790 }
792 public Name getQualifiedName() {
793 return fullname;
794 }
796 public Name flatName() {
797 return flatname;
798 }
800 public boolean isSubClass(Symbol base, Types types) {
801 if (this == base) {
802 return true;
803 } else if ((base.flags() & INTERFACE) != 0) {
804 for (Type t = type; t.tag == CLASS; t = types.supertype(t))
805 for (List<Type> is = types.interfaces(t);
806 is.nonEmpty();
807 is = is.tail)
808 if (is.head.tsym.isSubClass(base, types)) return true;
809 } else {
810 for (Type t = type; t.tag == CLASS; t = types.supertype(t))
811 if (t.tsym == base) return true;
812 }
813 return false;
814 }
816 /** Complete the elaboration of this symbol's definition.
817 */
818 public void complete() throws CompletionFailure {
819 try {
820 super.complete();
821 } catch (CompletionFailure ex) {
822 // quiet error recovery
823 flags_field |= (PUBLIC|STATIC);
824 this.type = new ErrorType(this, Type.noType);
825 throw ex;
826 }
827 }
829 public List<Type> getInterfaces() {
830 complete();
831 if (type instanceof ClassType) {
832 ClassType t = (ClassType)type;
833 if (t.interfaces_field == null) // FIXME: shouldn't be null
834 t.interfaces_field = List.nil();
835 return t.interfaces_field;
836 } else {
837 return List.nil();
838 }
839 }
841 public Type getSuperclass() {
842 complete();
843 if (type instanceof ClassType) {
844 ClassType t = (ClassType)type;
845 if (t.supertype_field == null) // FIXME: shouldn't be null
846 t.supertype_field = Type.noType;
847 // An interface has no superclass; its supertype is Object.
848 return t.isInterface()
849 ? Type.noType
850 : t.supertype_field;
851 } else {
852 return Type.noType;
853 }
854 }
856 public ElementKind getKind() {
857 long flags = flags();
858 if ((flags & ANNOTATION) != 0)
859 return ElementKind.ANNOTATION_TYPE;
860 else if ((flags & INTERFACE) != 0)
861 return ElementKind.INTERFACE;
862 else if ((flags & ENUM) != 0)
863 return ElementKind.ENUM;
864 else
865 return ElementKind.CLASS;
866 }
868 public NestingKind getNestingKind() {
869 complete();
870 if (owner.kind == PCK)
871 return NestingKind.TOP_LEVEL;
872 else if (name.isEmpty())
873 return NestingKind.ANONYMOUS;
874 else if (owner.kind == MTH)
875 return NestingKind.LOCAL;
876 else
877 return NestingKind.MEMBER;
878 }
880 /**
881 * @deprecated this method should never be used by javac internally.
882 */
883 @Override @Deprecated
884 public <A extends java.lang.annotation.Annotation> A getAnnotation(Class<A> annoType) {
885 return JavacElements.getAnnotation(this, annoType);
886 }
888 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
889 return v.visitType(this, p);
890 }
892 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
893 return v.visitClassSymbol(this, p);
894 }
895 }
898 /** A class for variable symbols
899 */
900 public static class VarSymbol extends Symbol implements VariableElement {
902 /** The variable's declaration position.
903 */
904 public int pos = Position.NOPOS;
906 /** The variable's address. Used for different purposes during
907 * flow analysis, translation and code generation.
908 * Flow analysis:
909 * If this is a blank final or local variable, its sequence number.
910 * Translation:
911 * If this is a private field, its access number.
912 * Code generation:
913 * If this is a local variable, its logical slot number.
914 */
915 public int adr = -1;
917 /** Construct a variable symbol, given its flags, name, type and owner.
918 */
919 public VarSymbol(long flags, Name name, Type type, Symbol owner) {
920 super(VAR, flags, name, type, owner);
921 }
923 /** Clone this symbol with new owner.
924 */
925 public VarSymbol clone(Symbol newOwner) {
926 VarSymbol v = new VarSymbol(flags_field, name, type, newOwner);
927 v.pos = pos;
928 v.adr = adr;
929 v.data = data;
930 // System.out.println("clone " + v + " in " + newOwner);//DEBUG
931 return v;
932 }
934 public String toString() {
935 return name.toString();
936 }
938 public Symbol asMemberOf(Type site, Types types) {
939 return new VarSymbol(flags_field, name, types.memberType(site, this), owner);
940 }
942 public ElementKind getKind() {
943 long flags = flags();
944 if ((flags & PARAMETER) != 0) {
945 if (isExceptionParameter())
946 return ElementKind.EXCEPTION_PARAMETER;
947 else
948 return ElementKind.PARAMETER;
949 } else if ((flags & ENUM) != 0) {
950 return ElementKind.ENUM_CONSTANT;
951 } else if (owner.kind == TYP || owner.kind == ERR) {
952 return ElementKind.FIELD;
953 } else {
954 return ElementKind.LOCAL_VARIABLE;
955 }
956 }
958 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
959 return v.visitVariable(this, p);
960 }
962 public Object getConstantValue() { // Mirror API
963 return Constants.decode(getConstValue(), type);
964 }
966 public void setLazyConstValue(final Env<AttrContext> env,
967 final Log log,
968 final Attr attr,
969 final JCTree.JCExpression initializer)
970 {
971 setData(new Callable<Object>() {
972 public Object call() {
973 JavaFileObject source = log.useSource(env.toplevel.sourcefile);
974 try {
975 Type itype = attr.attribExpr(initializer, env, type);
976 if (itype.constValue() != null)
977 return attr.coerce(itype, type).constValue();
978 else
979 return null;
980 } finally {
981 log.useSource(source);
982 }
983 }
984 });
985 }
987 /**
988 * The variable's constant value, if this is a constant.
989 * Before the constant value is evaluated, it points to an
990 * initalizer environment. If this is not a constant, it can
991 * be used for other stuff.
992 */
993 private Object data;
995 public boolean isExceptionParameter() {
996 return data == ElementKind.EXCEPTION_PARAMETER;
997 }
999 public boolean isResourceVariable() {
1000 return data == ElementKind.RESOURCE_VARIABLE;
1001 }
1003 public Object getConstValue() {
1004 // TODO: Consider if getConstValue and getConstantValue can be collapsed
1005 if (data == ElementKind.EXCEPTION_PARAMETER ||
1006 data == ElementKind.RESOURCE_VARIABLE) {
1007 return null;
1008 } else if (data instanceof Callable<?>) {
1009 // In this case, this is a final variable, with an as
1010 // yet unevaluated initializer.
1011 Callable<?> eval = (Callable<?>)data;
1012 data = null; // to make sure we don't evaluate this twice.
1013 try {
1014 data = eval.call();
1015 } catch (Exception ex) {
1016 throw new AssertionError(ex);
1017 }
1018 }
1019 return data;
1020 }
1022 public void setData(Object data) {
1023 assert !(data instanceof Env<?>) : this;
1024 this.data = data;
1025 }
1027 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
1028 return v.visitVarSymbol(this, p);
1029 }
1030 }
1032 /** A class for method symbols.
1033 */
1034 public static class MethodSymbol extends Symbol implements ExecutableElement {
1036 /** The code of the method. */
1037 public Code code = null;
1039 /** The parameters of the method. */
1040 public List<VarSymbol> params = null;
1042 /** The names of the parameters */
1043 public List<Name> savedParameterNames;
1045 /** For an attribute field accessor, its default value if any.
1046 * The value is null if none appeared in the method
1047 * declaration.
1048 */
1049 public Attribute defaultValue = null;
1051 /** Construct a method symbol, given its flags, name, type and owner.
1052 */
1053 public MethodSymbol(long flags, Name name, Type type, Symbol owner) {
1054 super(MTH, flags, name, type, owner);
1055 assert owner.type.tag != TYPEVAR : owner + "." + name;
1056 }
1058 /** Clone this symbol with new owner.
1059 */
1060 public MethodSymbol clone(Symbol newOwner) {
1061 MethodSymbol m = new MethodSymbol(flags_field, name, type, newOwner);
1062 m.code = code;
1063 return m;
1064 }
1066 /** The Java source which this symbol represents.
1067 */
1068 public String toString() {
1069 if ((flags() & BLOCK) != 0) {
1070 return owner.name.toString();
1071 } else {
1072 String s = (name == name.table.names.init)
1073 ? owner.name.toString()
1074 : name.toString();
1075 if (type != null) {
1076 if (type.tag == FORALL)
1077 s = "<" + ((ForAll)type).getTypeArguments() + ">" + s;
1078 s += "(" + type.argtypes((flags() & VARARGS) != 0) + ")";
1079 }
1080 return s;
1081 }
1082 }
1084 /** find a symbol that this (proxy method) symbol implements.
1085 * @param c The class whose members are searched for
1086 * implementations
1087 */
1088 public Symbol implemented(TypeSymbol c, Types types) {
1089 Symbol impl = null;
1090 for (List<Type> is = types.interfaces(c.type);
1091 impl == null && is.nonEmpty();
1092 is = is.tail) {
1093 TypeSymbol i = is.head.tsym;
1094 for (Scope.Entry e = i.members().lookup(name);
1095 impl == null && e.scope != null;
1096 e = e.next()) {
1097 if (this.overrides(e.sym, (TypeSymbol)owner, types, true) &&
1098 // FIXME: I suspect the following requires a
1099 // subst() for a parametric return type.
1100 types.isSameType(type.getReturnType(),
1101 types.memberType(owner.type, e.sym).getReturnType())) {
1102 impl = e.sym;
1103 }
1104 if (impl == null)
1105 impl = implemented(i, types);
1106 }
1107 }
1108 return impl;
1109 }
1111 /** Will the erasure of this method be considered by the VM to
1112 * override the erasure of the other when seen from class `origin'?
1113 */
1114 public boolean binaryOverrides(Symbol _other, TypeSymbol origin, Types types) {
1115 if (isConstructor() || _other.kind != MTH) return false;
1117 if (this == _other) return true;
1118 MethodSymbol other = (MethodSymbol)_other;
1120 // check for a direct implementation
1121 if (other.isOverridableIn((TypeSymbol)owner) &&
1122 types.asSuper(owner.type, other.owner) != null &&
1123 types.isSameType(erasure(types), other.erasure(types)))
1124 return true;
1126 // check for an inherited implementation
1127 return
1128 (flags() & ABSTRACT) == 0 &&
1129 other.isOverridableIn(origin) &&
1130 this.isMemberOf(origin, types) &&
1131 types.isSameType(erasure(types), other.erasure(types));
1132 }
1134 /** The implementation of this (abstract) symbol in class origin,
1135 * from the VM's point of view, null if method does not have an
1136 * implementation in class.
1137 * @param origin The class of which the implementation is a member.
1138 */
1139 public MethodSymbol binaryImplementation(ClassSymbol origin, Types types) {
1140 for (TypeSymbol c = origin; c != null; c = types.supertype(c.type).tsym) {
1141 for (Scope.Entry e = c.members().lookup(name);
1142 e.scope != null;
1143 e = e.next()) {
1144 if (e.sym.kind == MTH &&
1145 ((MethodSymbol)e.sym).binaryOverrides(this, origin, types))
1146 return (MethodSymbol)e.sym;
1147 }
1148 }
1149 return null;
1150 }
1152 /** Does this symbol override `other' symbol, when both are seen as
1153 * members of class `origin'? It is assumed that _other is a member
1154 * of origin.
1155 *
1156 * It is assumed that both symbols have the same name. The static
1157 * modifier is ignored for this test.
1158 *
1159 * See JLS 8.4.6.1 (without transitivity) and 8.4.6.4
1160 */
1161 public boolean overrides(Symbol _other, TypeSymbol origin, Types types, boolean checkResult) {
1162 if (isConstructor() || _other.kind != MTH) return false;
1164 if (this == _other) return true;
1165 MethodSymbol other = (MethodSymbol)_other;
1167 // check for a direct implementation
1168 if (other.isOverridableIn((TypeSymbol)owner) &&
1169 types.asSuper(owner.type, other.owner) != null) {
1170 Type mt = types.memberType(owner.type, this);
1171 Type ot = types.memberType(owner.type, other);
1172 if (types.isSubSignature(mt, ot)) {
1173 if (!checkResult)
1174 return true;
1175 if (types.returnTypeSubstitutable(mt, ot))
1176 return true;
1177 }
1178 }
1180 // check for an inherited implementation
1181 if ((flags() & ABSTRACT) != 0 ||
1182 (other.flags() & ABSTRACT) == 0 ||
1183 !other.isOverridableIn(origin) ||
1184 !this.isMemberOf(origin, types))
1185 return false;
1187 // assert types.asSuper(origin.type, other.owner) != null;
1188 Type mt = types.memberType(origin.type, this);
1189 Type ot = types.memberType(origin.type, other);
1190 return
1191 types.isSubSignature(mt, ot) &&
1192 (!checkResult || types.resultSubtype(mt, ot, Warner.noWarnings));
1193 }
1195 private boolean isOverridableIn(TypeSymbol origin) {
1196 // JLS3 8.4.6.1
1197 switch ((int)(flags_field & Flags.AccessFlags)) {
1198 case Flags.PRIVATE:
1199 return false;
1200 case Flags.PUBLIC:
1201 return true;
1202 case Flags.PROTECTED:
1203 return (origin.flags() & INTERFACE) == 0;
1204 case 0:
1205 // for package private: can only override in the same
1206 // package
1207 return
1208 this.packge() == origin.packge() &&
1209 (origin.flags() & INTERFACE) == 0;
1210 default:
1211 return false;
1212 }
1213 }
1215 /** The implementation of this (abstract) symbol in class origin;
1216 * null if none exists. Synthetic methods are not considered
1217 * as possible implementations.
1218 */
1219 public MethodSymbol implementation(TypeSymbol origin, Types types, boolean checkResult) {
1220 MethodSymbol res = types.implementation(this, origin, types, checkResult);
1221 if (res != null)
1222 return res;
1223 // if origin is derived from a raw type, we might have missed
1224 // an implementation because we do not know enough about instantiations.
1225 // in this case continue with the supertype as origin.
1226 if (types.isDerivedRaw(origin.type))
1227 return implementation(types.supertype(origin.type).tsym, types, checkResult);
1228 else
1229 return null;
1230 }
1232 public List<VarSymbol> params() {
1233 owner.complete();
1234 if (params == null) {
1235 // If ClassReader.saveParameterNames has been set true, then
1236 // savedParameterNames will be set to a list of names that
1237 // matches the types in type.getParameterTypes(). If any names
1238 // were not found in the class file, those names in the list will
1239 // be set to the empty name.
1240 // If ClassReader.saveParameterNames has been set false, then
1241 // savedParameterNames will be null.
1242 List<Name> paramNames = savedParameterNames;
1243 savedParameterNames = null;
1244 // discard the provided names if the list of names is the wrong size.
1245 if (paramNames == null || paramNames.size() != type.getParameterTypes().size())
1246 paramNames = List.nil();
1247 ListBuffer<VarSymbol> buf = new ListBuffer<VarSymbol>();
1248 List<Name> remaining = paramNames;
1249 // assert: remaining and paramNames are both empty or both
1250 // have same cardinality as type.getParameterTypes()
1251 int i = 0;
1252 for (Type t : type.getParameterTypes()) {
1253 Name paramName;
1254 if (remaining.isEmpty()) {
1255 // no names for any parameters available
1256 paramName = createArgName(i, paramNames);
1257 } else {
1258 paramName = remaining.head;
1259 remaining = remaining.tail;
1260 if (paramName.isEmpty()) {
1261 // no name for this specific parameter
1262 paramName = createArgName(i, paramNames);
1263 }
1264 }
1265 buf.append(new VarSymbol(PARAMETER, paramName, t, this));
1266 i++;
1267 }
1268 params = buf.toList();
1269 }
1270 return params;
1271 }
1273 // Create a name for the argument at position 'index' that is not in
1274 // the exclude list. In normal use, either no names will have been
1275 // provided, in which case the exclude list is empty, or all the names
1276 // will have been provided, in which case this method will not be called.
1277 private Name createArgName(int index, List<Name> exclude) {
1278 String prefix = "arg";
1279 while (true) {
1280 Name argName = name.table.fromString(prefix + index);
1281 if (!exclude.contains(argName))
1282 return argName;
1283 prefix += "$";
1284 }
1285 }
1287 public Symbol asMemberOf(Type site, Types types) {
1288 return new MethodSymbol(flags_field, name, types.memberType(site, this), owner);
1289 }
1291 public ElementKind getKind() {
1292 if (name == name.table.names.init)
1293 return ElementKind.CONSTRUCTOR;
1294 else if (name == name.table.names.clinit)
1295 return ElementKind.STATIC_INIT;
1296 else
1297 return ElementKind.METHOD;
1298 }
1300 public Attribute getDefaultValue() {
1301 return defaultValue;
1302 }
1304 public List<VarSymbol> getParameters() {
1305 return params();
1306 }
1308 public boolean isVarArgs() {
1309 return (flags() & VARARGS) != 0;
1310 }
1312 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
1313 return v.visitExecutable(this, p);
1314 }
1316 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
1317 return v.visitMethodSymbol(this, p);
1318 }
1320 public Type getReturnType() {
1321 return asType().getReturnType();
1322 }
1324 public List<Type> getThrownTypes() {
1325 return asType().getThrownTypes();
1326 }
1327 }
1329 /** A class for predefined operators.
1330 */
1331 public static class OperatorSymbol extends MethodSymbol {
1333 public int opcode;
1335 public OperatorSymbol(Name name, Type type, int opcode, Symbol owner) {
1336 super(PUBLIC | STATIC, name, type, owner);
1337 this.opcode = opcode;
1338 }
1340 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
1341 return v.visitOperatorSymbol(this, p);
1342 }
1343 }
1345 /** Symbol completer interface.
1346 */
1347 public static interface Completer {
1348 void complete(Symbol sym) throws CompletionFailure;
1349 }
1351 public static class CompletionFailure extends RuntimeException {
1352 private static final long serialVersionUID = 0;
1353 public Symbol sym;
1355 /** A diagnostic object describing the failure
1356 */
1357 public JCDiagnostic diag;
1359 /** A localized string describing the failure.
1360 * @deprecated Use {@code getDetail()} or {@code getMessage()}
1361 */
1362 @Deprecated
1363 public String errmsg;
1365 public CompletionFailure(Symbol sym, String errmsg) {
1366 this.sym = sym;
1367 this.errmsg = errmsg;
1368 // this.printStackTrace();//DEBUG
1369 }
1371 public CompletionFailure(Symbol sym, JCDiagnostic diag) {
1372 this.sym = sym;
1373 this.diag = diag;
1374 // this.printStackTrace();//DEBUG
1375 }
1377 public JCDiagnostic getDiagnostic() {
1378 return diag;
1379 }
1381 @Override
1382 public String getMessage() {
1383 if (diag != null)
1384 return diag.getMessage(null);
1385 else
1386 return errmsg;
1387 }
1389 public Object getDetailValue() {
1390 return (diag != null ? diag : errmsg);
1391 }
1393 @Override
1394 public CompletionFailure initCause(Throwable cause) {
1395 super.initCause(cause);
1396 return this;
1397 }
1399 }
1401 /**
1402 * A visitor for symbols. A visitor is used to implement operations
1403 * (or relations) on symbols. Most common operations on types are
1404 * binary relations and this interface is designed for binary
1405 * relations, that is, operations on the form
1406 * Symbol × P → R.
1407 * <!-- In plain text: Type x P -> R -->
1408 *
1409 * @param <R> the return type of the operation implemented by this
1410 * visitor; use Void if no return type is needed.
1411 * @param <P> the type of the second argument (the first being the
1412 * symbol itself) of the operation implemented by this visitor; use
1413 * Void if a second argument is not needed.
1414 */
1415 public interface Visitor<R,P> {
1416 R visitClassSymbol(ClassSymbol s, P arg);
1417 R visitMethodSymbol(MethodSymbol s, P arg);
1418 R visitPackageSymbol(PackageSymbol s, P arg);
1419 R visitOperatorSymbol(OperatorSymbol s, P arg);
1420 R visitVarSymbol(VarSymbol s, P arg);
1421 R visitTypeSymbol(TypeSymbol s, P arg);
1422 R visitSymbol(Symbol s, P arg);
1423 }
1424 }