Fri, 26 Jun 2009 18:51:39 -0700
6843077: JSR 308: Annotations on types
Reviewed-by: jjg, mcimadamore, darcy
Contributed-by: mernst@cs.washington.edu, mali@csail.mit.edu, mpapi@csail.mit.edu
1 /*
2 * Copyright 1999-2008 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any 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 API supported by Sun Microsystems. If
53 * 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)) {
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 /** Is this symbol a constructor?
229 */
230 public boolean isConstructor() {
231 return name == name.table.names.init;
232 }
234 /** The fully qualified name of this symbol.
235 * This is the same as the symbol's name except for class symbols,
236 * which are handled separately.
237 */
238 public Name getQualifiedName() {
239 return name;
240 }
242 /** The fully qualified name of this symbol after converting to flat
243 * representation. This is the same as the symbol's name except for
244 * class symbols, which are handled separately.
245 */
246 public Name flatName() {
247 return getQualifiedName();
248 }
250 /** If this is a class or package, its members, otherwise null.
251 */
252 public Scope members() {
253 return null;
254 }
256 /** A class is an inner class if it it has an enclosing instance class.
257 */
258 public boolean isInner() {
259 return type.getEnclosingType().tag == CLASS;
260 }
262 /** An inner class has an outer instance if it is not an interface
263 * it has an enclosing instance class which might be referenced from the class.
264 * Nested classes can see instance members of their enclosing class.
265 * Their constructors carry an additional this$n parameter, inserted
266 * implicitly by the compiler.
267 *
268 * @see #isInner
269 */
270 public boolean hasOuterInstance() {
271 return
272 type.getEnclosingType().tag == CLASS && (flags() & (INTERFACE | NOOUTERTHIS)) == 0;
273 }
275 /** The closest enclosing class of this symbol's declaration.
276 */
277 public ClassSymbol enclClass() {
278 Symbol c = this;
279 while (c != null &&
280 ((c.kind & TYP) == 0 || c.type.tag != CLASS)) {
281 c = c.owner;
282 }
283 return (ClassSymbol)c;
284 }
286 /** The outermost class which indirectly owns this symbol.
287 */
288 public ClassSymbol outermostClass() {
289 Symbol sym = this;
290 Symbol prev = null;
291 while (sym.kind != PCK) {
292 prev = sym;
293 sym = sym.owner;
294 }
295 return (ClassSymbol) prev;
296 }
298 /** The package which indirectly owns this symbol.
299 */
300 public PackageSymbol packge() {
301 Symbol sym = this;
302 while (sym.kind != PCK) {
303 sym = sym.owner;
304 }
305 return (PackageSymbol) sym;
306 }
308 /** Is this symbol a subclass of `base'? Only defined for ClassSymbols.
309 */
310 public boolean isSubClass(Symbol base, Types types) {
311 throw new AssertionError("isSubClass " + this);
312 }
314 /** Fully check membership: hierarchy, protection, and hiding.
315 * Does not exclude methods not inherited due to overriding.
316 */
317 public boolean isMemberOf(TypeSymbol clazz, Types types) {
318 return
319 owner == clazz ||
320 clazz.isSubClass(owner, types) &&
321 isInheritedIn(clazz, types) &&
322 !hiddenIn((ClassSymbol)clazz, types);
323 }
325 /** Is this symbol the same as or enclosed by the given class? */
326 public boolean isEnclosedBy(ClassSymbol clazz) {
327 for (Symbol sym = this; sym.kind != PCK; sym = sym.owner)
328 if (sym == clazz) return true;
329 return false;
330 }
332 /** Check for hiding. Note that this doesn't handle multiple
333 * (interface) inheritance. */
334 private boolean hiddenIn(ClassSymbol clazz, Types types) {
335 if (kind == MTH && (flags() & STATIC) == 0) return false;
336 while (true) {
337 if (owner == clazz) return false;
338 Scope.Entry e = clazz.members().lookup(name);
339 while (e.scope != null) {
340 if (e.sym == this) return false;
341 if (e.sym.kind == kind &&
342 (kind != MTH ||
343 (e.sym.flags() & STATIC) != 0 &&
344 types.isSubSignature(e.sym.type, type)))
345 return true;
346 e = e.next();
347 }
348 Type superType = types.supertype(clazz.type);
349 if (superType.tag != TypeTags.CLASS) return false;
350 clazz = (ClassSymbol)superType.tsym;
351 }
352 }
354 /** Is this symbol inherited into a given class?
355 * PRE: If symbol's owner is a interface,
356 * it is already assumed that the interface is a superinterface
357 * of given class.
358 * @param clazz The class for which we want to establish membership.
359 * This must be a subclass of the member's owner.
360 */
361 public boolean isInheritedIn(Symbol clazz, Types types) {
362 switch ((int)(flags_field & Flags.AccessFlags)) {
363 default: // error recovery
364 case PUBLIC:
365 return true;
366 case PRIVATE:
367 return this.owner == clazz;
368 case PROTECTED:
369 // we model interfaces as extending Object
370 return (clazz.flags() & INTERFACE) == 0;
371 case 0:
372 PackageSymbol thisPackage = this.packge();
373 for (Symbol sup = clazz;
374 sup != null && sup != this.owner;
375 sup = types.supertype(sup.type).tsym) {
376 while (sup.type.tag == TYPEVAR)
377 sup = sup.type.getUpperBound().tsym;
378 if (sup.type.isErroneous())
379 return true; // error recovery
380 if ((sup.flags() & COMPOUND) != 0)
381 continue;
382 if (sup.packge() != thisPackage)
383 return false;
384 }
385 return (clazz.flags() & INTERFACE) == 0;
386 }
387 }
389 /** The (variable or method) symbol seen as a member of given
390 * class type`site' (this might change the symbol's type).
391 * This is used exclusively for producing diagnostics.
392 */
393 public Symbol asMemberOf(Type site, Types types) {
394 throw new AssertionError();
395 }
397 /** Does this method symbol override `other' symbol, when both are seen as
398 * members of class `origin'? It is assumed that _other is a member
399 * of origin.
400 *
401 * It is assumed that both symbols have the same name. The static
402 * modifier is ignored for this test.
403 *
404 * See JLS 8.4.6.1 (without transitivity) and 8.4.6.4
405 */
406 public boolean overrides(Symbol _other, TypeSymbol origin, Types types, boolean checkResult) {
407 return false;
408 }
410 /** Complete the elaboration of this symbol's definition.
411 */
412 public void complete() throws CompletionFailure {
413 if (completer != null) {
414 Completer c = completer;
415 completer = null;
416 c.complete(this);
417 }
418 }
420 /** True if the symbol represents an entity that exists.
421 */
422 public boolean exists() {
423 return true;
424 }
426 public Type asType() {
427 return type;
428 }
430 public Symbol getEnclosingElement() {
431 return owner;
432 }
434 public ElementKind getKind() {
435 return ElementKind.OTHER; // most unkind
436 }
438 public Set<Modifier> getModifiers() {
439 return Flags.asModifierSet(flags());
440 }
442 public Name getSimpleName() {
443 return name;
444 }
446 /**
447 * @deprecated this method should never be used by javac internally.
448 */
449 @Deprecated
450 public <A extends java.lang.annotation.Annotation> A getAnnotation(Class<A> annoType) {
451 return JavacElements.getAnnotation(this, annoType);
452 }
454 // TODO: getEnclosedElements should return a javac List, fix in FilteredMemberList
455 public java.util.List<Symbol> getEnclosedElements() {
456 return List.nil();
457 }
459 public List<TypeSymbol> getTypeParameters() {
460 ListBuffer<TypeSymbol> l = ListBuffer.lb();
461 for (Type t : type.getTypeArguments()) {
462 l.append(t.tsym);
463 }
464 return l.toList();
465 }
467 public static class DelegatedSymbol extends Symbol {
468 protected Symbol other;
469 public DelegatedSymbol(Symbol other) {
470 super(other.kind, other.flags_field, other.name, other.type, other.owner);
471 this.other = other;
472 }
473 public String toString() { return other.toString(); }
474 public Symbol location() { return other.location(); }
475 public Symbol location(Type site, Types types) { return other.location(site, types); }
476 public Type erasure(Types types) { return other.erasure(types); }
477 public Type externalType(Types types) { return other.externalType(types); }
478 public boolean isLocal() { return other.isLocal(); }
479 public boolean isConstructor() { return other.isConstructor(); }
480 public Name getQualifiedName() { return other.getQualifiedName(); }
481 public Name flatName() { return other.flatName(); }
482 public Scope members() { return other.members(); }
483 public boolean isInner() { return other.isInner(); }
484 public boolean hasOuterInstance() { return other.hasOuterInstance(); }
485 public ClassSymbol enclClass() { return other.enclClass(); }
486 public ClassSymbol outermostClass() { return other.outermostClass(); }
487 public PackageSymbol packge() { return other.packge(); }
488 public boolean isSubClass(Symbol base, Types types) { return other.isSubClass(base, types); }
489 public boolean isMemberOf(TypeSymbol clazz, Types types) { return other.isMemberOf(clazz, types); }
490 public boolean isEnclosedBy(ClassSymbol clazz) { return other.isEnclosedBy(clazz); }
491 public boolean isInheritedIn(Symbol clazz, Types types) { return other.isInheritedIn(clazz, types); }
492 public Symbol asMemberOf(Type site, Types types) { return other.asMemberOf(site, types); }
493 public void complete() throws CompletionFailure { other.complete(); }
495 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
496 return other.accept(v, p);
497 }
499 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
500 return v.visitSymbol(other, p);
501 }
502 }
504 /** A class for type symbols. Type variables are represented by instances
505 * of this class, classes and packages by instances of subclasses.
506 */
507 public static class TypeSymbol
508 extends Symbol implements TypeParameterElement {
509 // Implements TypeParameterElement because type parameters don't
510 // have their own TypeSymbol subclass.
511 // TODO: type parameters should have their own TypeSymbol subclass
513 public TypeSymbol(long flags, Name name, Type type, Symbol owner) {
514 super(TYP, flags, name, type, owner);
515 }
517 /** form a fully qualified name from a name and an owner
518 */
519 static public Name formFullName(Name name, Symbol owner) {
520 if (owner == null) return name;
521 if (((owner.kind != ERR)) &&
522 ((owner.kind & (VAR | MTH)) != 0
523 || (owner.kind == TYP && owner.type.tag == TYPEVAR)
524 )) return name;
525 Name prefix = owner.getQualifiedName();
526 if (prefix == null || prefix == prefix.table.names.empty)
527 return name;
528 else return prefix.append('.', name);
529 }
531 /** form a fully qualified name from a name and an owner, after
532 * converting to flat representation
533 */
534 static public Name formFlatName(Name name, Symbol owner) {
535 if (owner == null ||
536 (owner.kind & (VAR | MTH)) != 0
537 || (owner.kind == TYP && owner.type.tag == TYPEVAR)
538 ) return name;
539 char sep = owner.kind == TYP ? '$' : '.';
540 Name prefix = owner.flatName();
541 if (prefix == null || prefix == prefix.table.names.empty)
542 return name;
543 else return prefix.append(sep, name);
544 }
546 /**
547 * A total ordering between type symbols that refines the
548 * class inheritance graph.
549 *
550 * Typevariables always precede other kinds of symbols.
551 */
552 public final boolean precedes(TypeSymbol that, Types types) {
553 if (this == that)
554 return false;
555 if (this.type.tag == that.type.tag) {
556 if (this.type.tag == CLASS) {
557 return
558 types.rank(that.type) < types.rank(this.type) ||
559 types.rank(that.type) == types.rank(this.type) &&
560 that.getQualifiedName().compareTo(this.getQualifiedName()) < 0;
561 } else if (this.type.tag == TYPEVAR) {
562 return types.isSubtype(this.type, that.type);
563 }
564 }
565 return this.type.tag == TYPEVAR;
566 }
568 // For type params; overridden in subclasses.
569 public ElementKind getKind() {
570 return ElementKind.TYPE_PARAMETER;
571 }
573 public java.util.List<Symbol> getEnclosedElements() {
574 List<Symbol> list = List.nil();
575 for (Scope.Entry e = members().elems; e != null; e = e.sibling) {
576 if (e.sym != null && (e.sym.flags() & SYNTHETIC) == 0 && e.sym.owner == this)
577 list = list.prepend(e.sym);
578 }
579 return list;
580 }
582 // For type params.
583 // Perhaps not needed if getEnclosingElement can be spec'ed
584 // to do the same thing.
585 // TODO: getGenericElement() might not be needed
586 public Symbol getGenericElement() {
587 return owner;
588 }
590 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
591 assert type.tag == TYPEVAR; // else override will be invoked
592 return v.visitTypeParameter(this, p);
593 }
595 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
596 return v.visitTypeSymbol(this, p);
597 }
599 public List<Type> getBounds() {
600 TypeVar t = (TypeVar)type;
601 Type bound = t.getUpperBound();
602 if (!bound.isCompound())
603 return List.of(bound);
604 ClassType ct = (ClassType)bound;
605 if (!ct.tsym.erasure_field.isInterface()) {
606 return ct.interfaces_field.prepend(ct.supertype_field);
607 } else {
608 // No superclass was given in bounds.
609 // In this case, supertype is Object, erasure is first interface.
610 return ct.interfaces_field;
611 }
612 }
613 }
615 /** A class for package symbols
616 */
617 public static class PackageSymbol extends TypeSymbol
618 implements PackageElement {
620 public Scope members_field;
621 public Name fullname;
622 public ClassSymbol package_info; // see bug 6443073
624 public PackageSymbol(Name name, Type type, Symbol owner) {
625 super(0, name, type, owner);
626 this.kind = PCK;
627 this.members_field = null;
628 this.fullname = formFullName(name, owner);
629 }
631 public PackageSymbol(Name name, Symbol owner) {
632 this(name, null, owner);
633 this.type = new PackageType(this);
634 }
636 public String toString() {
637 return fullname.toString();
638 }
640 public Name getQualifiedName() {
641 return fullname;
642 }
644 public boolean isUnnamed() {
645 return name.isEmpty() && owner != null;
646 }
648 public Scope members() {
649 if (completer != null) complete();
650 return members_field;
651 }
653 public long flags() {
654 if (completer != null) complete();
655 return flags_field;
656 }
658 public List<Attribute.Compound> getAnnotationMirrors() {
659 if (completer != null) complete();
660 assert attributes_field != null;
661 return attributes_field;
662 }
664 /** A package "exists" if a type or package that exists has
665 * been seen within it.
666 */
667 public boolean exists() {
668 return (flags_field & EXISTS) != 0;
669 }
671 public ElementKind getKind() {
672 return ElementKind.PACKAGE;
673 }
675 public Symbol getEnclosingElement() {
676 return null;
677 }
679 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
680 return v.visitPackage(this, p);
681 }
683 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
684 return v.visitPackageSymbol(this, p);
685 }
686 }
688 /** A class for class symbols
689 */
690 public static class ClassSymbol extends TypeSymbol implements TypeElement {
692 /** a scope for all class members; variables, methods and inner classes
693 * type parameters are not part of this scope
694 */
695 public Scope members_field;
697 /** the fully qualified name of the class, i.e. pck.outer.inner.
698 * null for anonymous classes
699 */
700 public Name fullname;
702 /** the fully qualified name of the class after converting to flat
703 * representation, i.e. pck.outer$inner,
704 * set externally for local and anonymous classes
705 */
706 public Name flatname;
708 /** the sourcefile where the class came from
709 */
710 public JavaFileObject sourcefile;
712 /** the classfile from where to load this class
713 * this will have extension .class or .java
714 */
715 public JavaFileObject classfile;
717 /** the constant pool of the class
718 */
719 public Pool pool;
721 public ClassSymbol(long flags, Name name, Type type, Symbol owner) {
722 super(flags, name, type, owner);
723 this.members_field = null;
724 this.fullname = formFullName(name, owner);
725 this.flatname = formFlatName(name, owner);
726 this.sourcefile = null;
727 this.classfile = null;
728 this.pool = null;
729 }
731 public ClassSymbol(long flags, Name name, Symbol owner) {
732 this(
733 flags,
734 name,
735 new ClassType(Type.noType, null, null),
736 owner);
737 this.type.tsym = this;
738 }
740 /** The Java source which this symbol represents.
741 */
742 public String toString() {
743 return className();
744 }
746 public long flags() {
747 if (completer != null) complete();
748 return flags_field;
749 }
751 public Scope members() {
752 if (completer != null) complete();
753 return members_field;
754 }
756 public List<Attribute.Compound> getAnnotationMirrors() {
757 if (completer != null) complete();
758 assert attributes_field != null;
759 return attributes_field;
760 }
762 public Type erasure(Types types) {
763 if (erasure_field == null)
764 erasure_field = new ClassType(types.erasure(type.getEnclosingType()),
765 List.<Type>nil(), this);
766 return erasure_field;
767 }
769 public String className() {
770 if (name.isEmpty())
771 return
772 Log.getLocalizedString("anonymous.class", flatname);
773 else
774 return fullname.toString();
775 }
777 public Name getQualifiedName() {
778 return fullname;
779 }
781 public Name flatName() {
782 return flatname;
783 }
785 public boolean isSubClass(Symbol base, Types types) {
786 if (this == base) {
787 return true;
788 } else if ((base.flags() & INTERFACE) != 0) {
789 for (Type t = type; t.tag == CLASS; t = types.supertype(t))
790 for (List<Type> is = types.interfaces(t);
791 is.nonEmpty();
792 is = is.tail)
793 if (is.head.tsym.isSubClass(base, types)) return true;
794 } else {
795 for (Type t = type; t.tag == CLASS; t = types.supertype(t))
796 if (t.tsym == base) return true;
797 }
798 return false;
799 }
801 /** Complete the elaboration of this symbol's definition.
802 */
803 public void complete() throws CompletionFailure {
804 try {
805 super.complete();
806 } catch (CompletionFailure ex) {
807 // quiet error recovery
808 flags_field |= (PUBLIC|STATIC);
809 this.type = new ErrorType(this, Type.noType);
810 throw ex;
811 }
812 }
814 public List<Type> getInterfaces() {
815 complete();
816 if (type instanceof ClassType) {
817 ClassType t = (ClassType)type;
818 if (t.interfaces_field == null) // FIXME: shouldn't be null
819 t.interfaces_field = List.nil();
820 return t.interfaces_field;
821 } else {
822 return List.nil();
823 }
824 }
826 public Type getSuperclass() {
827 complete();
828 if (type instanceof ClassType) {
829 ClassType t = (ClassType)type;
830 if (t.supertype_field == null) // FIXME: shouldn't be null
831 t.supertype_field = Type.noType;
832 // An interface has no superclass; its supertype is Object.
833 return t.isInterface()
834 ? Type.noType
835 : t.supertype_field;
836 } else {
837 return Type.noType;
838 }
839 }
841 public ElementKind getKind() {
842 long flags = flags();
843 if ((flags & ANNOTATION) != 0)
844 return ElementKind.ANNOTATION_TYPE;
845 else if ((flags & INTERFACE) != 0)
846 return ElementKind.INTERFACE;
847 else if ((flags & ENUM) != 0)
848 return ElementKind.ENUM;
849 else
850 return ElementKind.CLASS;
851 }
853 public NestingKind getNestingKind() {
854 complete();
855 if (owner.kind == PCK)
856 return NestingKind.TOP_LEVEL;
857 else if (name.isEmpty())
858 return NestingKind.ANONYMOUS;
859 else if (owner.kind == MTH)
860 return NestingKind.LOCAL;
861 else
862 return NestingKind.MEMBER;
863 }
865 /**
866 * @deprecated this method should never be used by javac internally.
867 */
868 @Override @Deprecated
869 public <A extends java.lang.annotation.Annotation> A getAnnotation(Class<A> annoType) {
870 return JavacElements.getAnnotation(this, annoType);
871 }
873 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
874 return v.visitType(this, p);
875 }
877 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
878 return v.visitClassSymbol(this, p);
879 }
880 }
883 /** A class for variable symbols
884 */
885 public static class VarSymbol extends Symbol implements VariableElement {
887 /** The variable's declaration position.
888 */
889 public int pos = Position.NOPOS;
891 /** The variable's address. Used for different purposes during
892 * flow analysis, translation and code generation.
893 * Flow analysis:
894 * If this is a blank final or local variable, its sequence number.
895 * Translation:
896 * If this is a private field, its access number.
897 * Code generation:
898 * If this is a local variable, its logical slot number.
899 */
900 public int adr = -1;
902 /** Construct a variable symbol, given its flags, name, type and owner.
903 */
904 public VarSymbol(long flags, Name name, Type type, Symbol owner) {
905 super(VAR, flags, name, type, owner);
906 }
908 /** Clone this symbol with new owner.
909 */
910 public VarSymbol clone(Symbol newOwner) {
911 VarSymbol v = new VarSymbol(flags_field, name, type, newOwner);
912 v.pos = pos;
913 v.adr = adr;
914 v.data = data;
915 // System.out.println("clone " + v + " in " + newOwner);//DEBUG
916 return v;
917 }
919 public String toString() {
920 return name.toString();
921 }
923 public Symbol asMemberOf(Type site, Types types) {
924 return new VarSymbol(flags_field, name, types.memberType(site, this), owner);
925 }
927 public ElementKind getKind() {
928 long flags = flags();
929 if ((flags & PARAMETER) != 0) {
930 if (isExceptionParameter())
931 return ElementKind.EXCEPTION_PARAMETER;
932 else
933 return ElementKind.PARAMETER;
934 } else if ((flags & ENUM) != 0) {
935 return ElementKind.ENUM_CONSTANT;
936 } else if (owner.kind == TYP || owner.kind == ERR) {
937 return ElementKind.FIELD;
938 } else {
939 return ElementKind.LOCAL_VARIABLE;
940 }
941 }
943 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
944 return v.visitVariable(this, p);
945 }
947 public Object getConstantValue() { // Mirror API
948 return Constants.decode(getConstValue(), type);
949 }
951 public void setLazyConstValue(final Env<AttrContext> env,
952 final Log log,
953 final Attr attr,
954 final JCTree.JCExpression initializer)
955 {
956 setData(new Callable<Object>() {
957 public Object call() {
958 JavaFileObject source = log.useSource(env.toplevel.sourcefile);
959 try {
960 Type itype = attr.attribExpr(initializer, env, type);
961 if (itype.constValue() != null)
962 return attr.coerce(itype, type).constValue();
963 else
964 return null;
965 } finally {
966 log.useSource(source);
967 }
968 }
969 });
970 }
972 /**
973 * The variable's constant value, if this is a constant.
974 * Before the constant value is evaluated, it points to an
975 * initalizer environment. If this is not a constant, it can
976 * be used for other stuff.
977 */
978 private Object data;
980 public boolean isExceptionParameter() {
981 return data == ElementKind.EXCEPTION_PARAMETER;
982 }
984 public Object getConstValue() {
985 // TODO: Consider if getConstValue and getConstantValue can be collapsed
986 if (data == ElementKind.EXCEPTION_PARAMETER) {
987 return null;
988 } else if (data instanceof Callable<?>) {
989 // In this case, this is final a variable, with an as
990 // yet unevaluated initializer.
991 Callable<?> eval = (Callable<?>)data;
992 data = null; // to make sure we don't evaluate this twice.
993 try {
994 data = eval.call();
995 } catch (Exception ex) {
996 throw new AssertionError(ex);
997 }
998 }
999 return data;
1000 }
1002 public void setData(Object data) {
1003 assert !(data instanceof Env<?>) : this;
1004 this.data = data;
1005 }
1007 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
1008 return v.visitVarSymbol(this, p);
1009 }
1010 }
1012 /** A class for method symbols.
1013 */
1014 public static class MethodSymbol extends Symbol implements ExecutableElement {
1016 /** The code of the method. */
1017 public Code code = null;
1019 /** The parameters of the method. */
1020 public List<VarSymbol> params = null;
1022 /** The names of the parameters */
1023 public List<Name> savedParameterNames;
1025 /** For an attribute field accessor, its default value if any.
1026 * The value is null if none appeared in the method
1027 * declaration.
1028 */
1029 public Attribute defaultValue = null;
1031 /** Construct a method symbol, given its flags, name, type and owner.
1032 */
1033 public MethodSymbol(long flags, Name name, Type type, Symbol owner) {
1034 super(MTH, flags, name, type, owner);
1035 assert owner.type.tag != TYPEVAR : owner + "." + name;
1036 }
1038 /** Clone this symbol with new owner.
1039 */
1040 public MethodSymbol clone(Symbol newOwner) {
1041 MethodSymbol m = new MethodSymbol(flags_field, name, type, newOwner);
1042 m.code = code;
1043 return m;
1044 }
1046 /** The Java source which this symbol represents.
1047 */
1048 public String toString() {
1049 if ((flags() & BLOCK) != 0) {
1050 return owner.name.toString();
1051 } else {
1052 String s = (name == name.table.names.init)
1053 ? owner.name.toString()
1054 : name.toString();
1055 if (type != null) {
1056 if (type.tag == FORALL)
1057 s = "<" + ((ForAll)type).getTypeArguments() + ">" + s;
1058 s += "(" + type.argtypes((flags() & VARARGS) != 0) + ")";
1059 }
1060 return s;
1061 }
1062 }
1064 /** find a symbol that this (proxy method) symbol implements.
1065 * @param c The class whose members are searched for
1066 * implementations
1067 */
1068 public Symbol implemented(TypeSymbol c, Types types) {
1069 Symbol impl = null;
1070 for (List<Type> is = types.interfaces(c.type);
1071 impl == null && is.nonEmpty();
1072 is = is.tail) {
1073 TypeSymbol i = is.head.tsym;
1074 for (Scope.Entry e = i.members().lookup(name);
1075 impl == null && e.scope != null;
1076 e = e.next()) {
1077 if (this.overrides(e.sym, (TypeSymbol)owner, types, true) &&
1078 // FIXME: I suspect the following requires a
1079 // subst() for a parametric return type.
1080 types.isSameType(type.getReturnType(),
1081 types.memberType(owner.type, e.sym).getReturnType())) {
1082 impl = e.sym;
1083 }
1084 if (impl == null)
1085 impl = implemented(i, types);
1086 }
1087 }
1088 return impl;
1089 }
1091 /** Will the erasure of this method be considered by the VM to
1092 * override the erasure of the other when seen from class `origin'?
1093 */
1094 public boolean binaryOverrides(Symbol _other, TypeSymbol origin, Types types) {
1095 if (isConstructor() || _other.kind != MTH) return false;
1097 if (this == _other) return true;
1098 MethodSymbol other = (MethodSymbol)_other;
1100 // check for a direct implementation
1101 if (other.isOverridableIn((TypeSymbol)owner) &&
1102 types.asSuper(owner.type, other.owner) != null &&
1103 types.isSameType(erasure(types), other.erasure(types)))
1104 return true;
1106 // check for an inherited implementation
1107 return
1108 (flags() & ABSTRACT) == 0 &&
1109 other.isOverridableIn(origin) &&
1110 this.isMemberOf(origin, types) &&
1111 types.isSameType(erasure(types), other.erasure(types));
1112 }
1114 /** The implementation of this (abstract) symbol in class origin,
1115 * from the VM's point of view, null if method does not have an
1116 * implementation in class.
1117 * @param origin The class of which the implementation is a member.
1118 */
1119 public MethodSymbol binaryImplementation(ClassSymbol origin, Types types) {
1120 for (TypeSymbol c = origin; c != null; c = types.supertype(c.type).tsym) {
1121 for (Scope.Entry e = c.members().lookup(name);
1122 e.scope != null;
1123 e = e.next()) {
1124 if (e.sym.kind == MTH &&
1125 ((MethodSymbol)e.sym).binaryOverrides(this, origin, types))
1126 return (MethodSymbol)e.sym;
1127 }
1128 }
1129 return null;
1130 }
1132 /** Does this symbol override `other' symbol, when both are seen as
1133 * members of class `origin'? It is assumed that _other is a member
1134 * of origin.
1135 *
1136 * It is assumed that both symbols have the same name. The static
1137 * modifier is ignored for this test.
1138 *
1139 * See JLS 8.4.6.1 (without transitivity) and 8.4.6.4
1140 */
1141 public boolean overrides(Symbol _other, TypeSymbol origin, Types types, boolean checkResult) {
1142 if (isConstructor() || _other.kind != MTH) return false;
1144 if (this == _other) return true;
1145 MethodSymbol other = (MethodSymbol)_other;
1147 // check for a direct implementation
1148 if (other.isOverridableIn((TypeSymbol)owner) &&
1149 types.asSuper(owner.type, other.owner) != null) {
1150 Type mt = types.memberType(owner.type, this);
1151 Type ot = types.memberType(owner.type, other);
1152 if (types.isSubSignature(mt, ot)) {
1153 if (!checkResult)
1154 return true;
1155 if (types.returnTypeSubstitutable(mt, ot))
1156 return true;
1157 }
1158 }
1160 // check for an inherited implementation
1161 if ((flags() & ABSTRACT) != 0 ||
1162 (other.flags() & ABSTRACT) == 0 ||
1163 !other.isOverridableIn(origin) ||
1164 !this.isMemberOf(origin, types))
1165 return false;
1167 // assert types.asSuper(origin.type, other.owner) != null;
1168 Type mt = types.memberType(origin.type, this);
1169 Type ot = types.memberType(origin.type, other);
1170 return
1171 types.isSubSignature(mt, ot) &&
1172 (!checkResult || types.resultSubtype(mt, ot, Warner.noWarnings));
1173 }
1175 private boolean isOverridableIn(TypeSymbol origin) {
1176 // JLS3 8.4.6.1
1177 switch ((int)(flags_field & Flags.AccessFlags)) {
1178 case Flags.PRIVATE:
1179 return false;
1180 case Flags.PUBLIC:
1181 return true;
1182 case Flags.PROTECTED:
1183 return (origin.flags() & INTERFACE) == 0;
1184 case 0:
1185 // for package private: can only override in the same
1186 // package
1187 return
1188 this.packge() == origin.packge() &&
1189 (origin.flags() & INTERFACE) == 0;
1190 default:
1191 return false;
1192 }
1193 }
1195 /** The implementation of this (abstract) symbol in class origin;
1196 * null if none exists. Synthetic methods are not considered
1197 * as possible implementations.
1198 */
1199 public MethodSymbol implementation(TypeSymbol origin, Types types, boolean checkResult) {
1200 for (Type t = origin.type; t.tag == CLASS || t.tag == TYPEVAR; t = types.supertype(t)) {
1201 while (t.tag == TYPEVAR)
1202 t = t.getUpperBound();
1203 TypeSymbol c = t.tsym;
1204 for (Scope.Entry e = c.members().lookup(name);
1205 e.scope != null;
1206 e = e.next()) {
1207 if (e.sym.kind == MTH) {
1208 MethodSymbol m = (MethodSymbol) e.sym;
1209 if (m.overrides(this, origin, types, checkResult) &&
1210 (m.flags() & SYNTHETIC) == 0)
1211 return m;
1212 }
1213 }
1214 }
1215 // if origin is derived from a raw type, we might have missed
1216 // an implementation because we do not know enough about instantiations.
1217 // in this case continue with the supertype as origin.
1218 if (types.isDerivedRaw(origin.type))
1219 return implementation(types.supertype(origin.type).tsym, types, checkResult);
1220 else
1221 return null;
1222 }
1224 public List<VarSymbol> params() {
1225 owner.complete();
1226 if (params == null) {
1227 List<Name> names = savedParameterNames;
1228 savedParameterNames = null;
1229 if (names == null) {
1230 names = List.nil();
1231 int i = 0;
1232 for (Type t : type.getParameterTypes())
1233 names = names.prepend(name.table.fromString("arg" + i++));
1234 names = names.reverse();
1235 }
1236 ListBuffer<VarSymbol> buf = new ListBuffer<VarSymbol>();
1237 for (Type t : type.getParameterTypes()) {
1238 buf.append(new VarSymbol(PARAMETER, names.head, t, this));
1239 names = names.tail;
1240 }
1241 params = buf.toList();
1242 }
1243 return params;
1244 }
1246 public Symbol asMemberOf(Type site, Types types) {
1247 return new MethodSymbol(flags_field, name, types.memberType(site, this), owner);
1248 }
1250 public ElementKind getKind() {
1251 if (name == name.table.names.init)
1252 return ElementKind.CONSTRUCTOR;
1253 else if (name == name.table.names.clinit)
1254 return ElementKind.STATIC_INIT;
1255 else
1256 return ElementKind.METHOD;
1257 }
1259 public Attribute getDefaultValue() {
1260 return defaultValue;
1261 }
1263 public List<VarSymbol> getParameters() {
1264 return params();
1265 }
1267 public boolean isVarArgs() {
1268 return (flags() & VARARGS) != 0;
1269 }
1271 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
1272 return v.visitExecutable(this, p);
1273 }
1275 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
1276 return v.visitMethodSymbol(this, p);
1277 }
1279 public Type getReturnType() {
1280 return asType().getReturnType();
1281 }
1283 public List<Type> getThrownTypes() {
1284 return asType().getThrownTypes();
1285 }
1286 }
1288 /** A class for predefined operators.
1289 */
1290 public static class OperatorSymbol extends MethodSymbol {
1292 public int opcode;
1294 public OperatorSymbol(Name name, Type type, int opcode, Symbol owner) {
1295 super(PUBLIC | STATIC, name, type, owner);
1296 this.opcode = opcode;
1297 }
1299 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) {
1300 return v.visitOperatorSymbol(this, p);
1301 }
1302 }
1304 /** Symbol completer interface.
1305 */
1306 public static interface Completer {
1307 void complete(Symbol sym) throws CompletionFailure;
1308 }
1310 public static class CompletionFailure extends RuntimeException {
1311 private static final long serialVersionUID = 0;
1312 public Symbol sym;
1314 /** A diagnostic object describing the failure
1315 */
1316 public JCDiagnostic diag;
1318 /** A localized string describing the failure.
1319 * @deprecated Use {@code getDetail()} or {@code getMessage()}
1320 */
1321 @Deprecated
1322 public String errmsg;
1324 public CompletionFailure(Symbol sym, String errmsg) {
1325 this.sym = sym;
1326 this.errmsg = errmsg;
1327 // this.printStackTrace();//DEBUG
1328 }
1330 public CompletionFailure(Symbol sym, JCDiagnostic diag) {
1331 this.sym = sym;
1332 this.diag = diag;
1333 // this.printStackTrace();//DEBUG
1334 }
1336 public JCDiagnostic getDiagnostic() {
1337 return diag;
1338 }
1340 @Override
1341 public String getMessage() {
1342 if (diag != null)
1343 return diag.getMessage(null);
1344 else
1345 return errmsg;
1346 }
1348 public Object getDetailValue() {
1349 return (diag != null ? diag : errmsg);
1350 }
1352 @Override
1353 public CompletionFailure initCause(Throwable cause) {
1354 super.initCause(cause);
1355 return this;
1356 }
1358 }
1360 /**
1361 * A visitor for symbols. A visitor is used to implement operations
1362 * (or relations) on symbols. Most common operations on types are
1363 * binary relations and this interface is designed for binary
1364 * relations, that is, operations on the form
1365 * Symbol × P → R.
1366 * <!-- In plain text: Type x P -> R -->
1367 *
1368 * @param <R> the return type of the operation implemented by this
1369 * visitor; use Void if no return type is needed.
1370 * @param <P> the type of the second argument (the first being the
1371 * symbol itself) of the operation implemented by this visitor; use
1372 * Void if a second argument is not needed.
1373 */
1374 public interface Visitor<R,P> {
1375 R visitClassSymbol(ClassSymbol s, P arg);
1376 R visitMethodSymbol(MethodSymbol s, P arg);
1377 R visitPackageSymbol(PackageSymbol s, P arg);
1378 R visitOperatorSymbol(OperatorSymbol s, P arg);
1379 R visitVarSymbol(VarSymbol s, P arg);
1380 R visitTypeSymbol(TypeSymbol s, P arg);
1381 R visitSymbol(Symbol s, P arg);
1382 }
1383 }