Symbol.java revision 3640:53ebb47dc802
1/* 2 * Copyright (c) 1999, 2016, 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 */ 25 26package com.sun.tools.javac.code; 27 28import java.lang.annotation.Annotation; 29import java.lang.annotation.Inherited; 30import java.util.Collections; 31import java.util.Map; 32import java.util.Set; 33import java.util.concurrent.Callable; 34 35import javax.lang.model.element.Element; 36import javax.lang.model.element.ElementKind; 37import javax.lang.model.element.ElementVisitor; 38import javax.lang.model.element.ExecutableElement; 39import javax.lang.model.element.Modifier; 40import javax.lang.model.element.ModuleElement; 41import javax.lang.model.element.NestingKind; 42import javax.lang.model.element.PackageElement; 43import javax.lang.model.element.TypeElement; 44import javax.lang.model.element.TypeParameterElement; 45import javax.lang.model.element.VariableElement; 46import javax.tools.JavaFileManager; 47import javax.tools.JavaFileObject; 48 49import com.sun.tools.javac.code.ClassFinder.BadEnclosingMethodAttr; 50import com.sun.tools.javac.code.Kinds.Kind; 51import com.sun.tools.javac.comp.Annotate.AnnotationTypeMetadata; 52import com.sun.tools.javac.code.Scope.WriteableScope; 53import com.sun.tools.javac.code.Type.*; 54import com.sun.tools.javac.comp.Attr; 55import com.sun.tools.javac.comp.AttrContext; 56import com.sun.tools.javac.comp.Env; 57import com.sun.tools.javac.jvm.*; 58import com.sun.tools.javac.tree.JCTree.JCFieldAccess; 59import com.sun.tools.javac.tree.JCTree.JCVariableDecl; 60import com.sun.tools.javac.tree.JCTree.Tag; 61import com.sun.tools.javac.util.*; 62import com.sun.tools.javac.util.DefinedBy.Api; 63import com.sun.tools.javac.util.Name; 64 65import static com.sun.tools.javac.code.Flags.*; 66import static com.sun.tools.javac.code.Kinds.*; 67import static com.sun.tools.javac.code.Kinds.Kind.*; 68import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 69import static com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode.FIRSTASGOP; 70import static com.sun.tools.javac.code.TypeTag.CLASS; 71import static com.sun.tools.javac.code.TypeTag.FORALL; 72import static com.sun.tools.javac.code.TypeTag.TYPEVAR; 73import static com.sun.tools.javac.jvm.ByteCodes.iadd; 74import static com.sun.tools.javac.jvm.ByteCodes.ishll; 75import static com.sun.tools.javac.jvm.ByteCodes.lushrl; 76import static com.sun.tools.javac.jvm.ByteCodes.lxor; 77import static com.sun.tools.javac.jvm.ByteCodes.string_add; 78 79/** Root class for Java symbols. It contains subclasses 80 * for specific sorts of symbols, such as variables, methods and operators, 81 * types, packages. Each subclass is represented as a static inner class 82 * inside Symbol. 83 * 84 * <p><b>This is NOT part of any supported API. 85 * If you write code that depends on this, you do so at your own risk. 86 * This code and its internal interfaces are subject to change or 87 * deletion without notice.</b> 88 */ 89public abstract class Symbol extends AnnoConstruct implements Element { 90 91 /** The kind of this symbol. 92 * @see Kinds 93 */ 94 public Kind kind; 95 96 /** The flags of this symbol. 97 */ 98 public long flags_field; 99 100 /** An accessor method for the flags of this symbol. 101 * Flags of class symbols should be accessed through the accessor 102 * method to make sure that the class symbol is loaded. 103 */ 104 public long flags() { return flags_field; } 105 106 /** The name of this symbol in Utf8 representation. 107 */ 108 public Name name; 109 110 /** The type of this symbol. 111 */ 112 public Type type; 113 114 /** The owner of this symbol. 115 */ 116 public Symbol owner; 117 118 /** The completer of this symbol. 119 * This should never equal null (NULL_COMPLETER should be used instead). 120 */ 121 public Completer completer; 122 123 /** A cache for the type erasure of this symbol. 124 */ 125 public Type erasure_field; 126 127 // <editor-fold defaultstate="collapsed" desc="annotations"> 128 129 /** The attributes of this symbol are contained in this 130 * SymbolMetadata. The SymbolMetadata instance is NOT immutable. 131 */ 132 protected SymbolMetadata metadata; 133 134 135 /** An accessor method for the attributes of this symbol. 136 * Attributes of class symbols should be accessed through the accessor 137 * method to make sure that the class symbol is loaded. 138 */ 139 public List<Attribute.Compound> getRawAttributes() { 140 return (metadata == null) 141 ? List.<Attribute.Compound>nil() 142 : metadata.getDeclarationAttributes(); 143 } 144 145 /** An accessor method for the type attributes of this symbol. 146 * Attributes of class symbols should be accessed through the accessor 147 * method to make sure that the class symbol is loaded. 148 */ 149 public List<Attribute.TypeCompound> getRawTypeAttributes() { 150 return (metadata == null) 151 ? List.<Attribute.TypeCompound>nil() 152 : metadata.getTypeAttributes(); 153 } 154 155 /** Fetch a particular annotation from a symbol. */ 156 public Attribute.Compound attribute(Symbol anno) { 157 for (Attribute.Compound a : getRawAttributes()) { 158 if (a.type.tsym == anno) return a; 159 } 160 return null; 161 } 162 163 public boolean annotationsPendingCompletion() { 164 return metadata == null ? false : metadata.pendingCompletion(); 165 } 166 167 public void appendAttributes(List<Attribute.Compound> l) { 168 if (l.nonEmpty()) { 169 initedMetadata().append(l); 170 } 171 } 172 173 public void appendClassInitTypeAttributes(List<Attribute.TypeCompound> l) { 174 if (l.nonEmpty()) { 175 initedMetadata().appendClassInitTypeAttributes(l); 176 } 177 } 178 179 public void appendInitTypeAttributes(List<Attribute.TypeCompound> l) { 180 if (l.nonEmpty()) { 181 initedMetadata().appendInitTypeAttributes(l); 182 } 183 } 184 185 public void appendUniqueTypeAttributes(List<Attribute.TypeCompound> l) { 186 if (l.nonEmpty()) { 187 initedMetadata().appendUniqueTypes(l); 188 } 189 } 190 191 public List<Attribute.TypeCompound> getClassInitTypeAttributes() { 192 return (metadata == null) 193 ? List.<Attribute.TypeCompound>nil() 194 : metadata.getClassInitTypeAttributes(); 195 } 196 197 public List<Attribute.TypeCompound> getInitTypeAttributes() { 198 return (metadata == null) 199 ? List.<Attribute.TypeCompound>nil() 200 : metadata.getInitTypeAttributes(); 201 } 202 203 public void setInitTypeAttributes(List<Attribute.TypeCompound> l) { 204 initedMetadata().setInitTypeAttributes(l); 205 } 206 207 public void setClassInitTypeAttributes(List<Attribute.TypeCompound> l) { 208 initedMetadata().setClassInitTypeAttributes(l); 209 } 210 211 public List<Attribute.Compound> getDeclarationAttributes() { 212 return (metadata == null) 213 ? List.<Attribute.Compound>nil() 214 : metadata.getDeclarationAttributes(); 215 } 216 217 public boolean hasAnnotations() { 218 return (metadata != null && !metadata.isEmpty()); 219 } 220 221 public boolean hasTypeAnnotations() { 222 return (metadata != null && !metadata.isTypesEmpty()); 223 } 224 225 public boolean isCompleted() { 226 return completer.isTerminal(); 227 } 228 229 public void prependAttributes(List<Attribute.Compound> l) { 230 if (l.nonEmpty()) { 231 initedMetadata().prepend(l); 232 } 233 } 234 235 public void resetAnnotations() { 236 initedMetadata().reset(); 237 } 238 239 public void setAttributes(Symbol other) { 240 if (metadata != null || other.metadata != null) { 241 initedMetadata().setAttributes(other.metadata); 242 } 243 } 244 245 public void setDeclarationAttributes(List<Attribute.Compound> a) { 246 if (metadata != null || a.nonEmpty()) { 247 initedMetadata().setDeclarationAttributes(a); 248 } 249 } 250 251 public void setTypeAttributes(List<Attribute.TypeCompound> a) { 252 if (metadata != null || a.nonEmpty()) { 253 if (metadata == null) 254 metadata = new SymbolMetadata(this); 255 metadata.setTypeAttributes(a); 256 } 257 } 258 259 private SymbolMetadata initedMetadata() { 260 if (metadata == null) 261 metadata = new SymbolMetadata(this); 262 return metadata; 263 } 264 265 /** This method is intended for debugging only. */ 266 public SymbolMetadata getMetadata() { 267 return metadata; 268 } 269 270 // </editor-fold> 271 272 /** Construct a symbol with given kind, flags, name, type and owner. 273 */ 274 public Symbol(Kind kind, long flags, Name name, Type type, Symbol owner) { 275 this.kind = kind; 276 this.flags_field = flags; 277 this.type = type; 278 this.owner = owner; 279 this.completer = Completer.NULL_COMPLETER; 280 this.erasure_field = null; 281 this.name = name; 282 } 283 284 /** Clone this symbol with new owner. 285 * Legal only for fields and methods. 286 */ 287 public Symbol clone(Symbol newOwner) { 288 throw new AssertionError(); 289 } 290 291 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) { 292 return v.visitSymbol(this, p); 293 } 294 295 /** The Java source which this symbol represents. 296 * A description of this symbol; overrides Object. 297 */ 298 public String toString() { 299 return name.toString(); 300 } 301 302 /** A Java source description of the location of this symbol; used for 303 * error reporting. 304 * 305 * @return null if the symbol is a package or a toplevel class defined in 306 * the default package; otherwise, the owner symbol is returned 307 */ 308 public Symbol location() { 309 if (owner.name == null || (owner.name.isEmpty() && 310 (owner.flags() & BLOCK) == 0 && 311 owner.kind != PCK && 312 owner.kind != TYP)) { 313 return null; 314 } 315 return owner; 316 } 317 318 public Symbol location(Type site, Types types) { 319 if (owner.name == null || owner.name.isEmpty()) { 320 return location(); 321 } 322 if (owner.type.hasTag(CLASS)) { 323 Type ownertype = types.asOuterSuper(site, owner); 324 if (ownertype != null) return ownertype.tsym; 325 } 326 return owner; 327 } 328 329 public Symbol baseSymbol() { 330 return this; 331 } 332 333 /** The symbol's erased type. 334 */ 335 public Type erasure(Types types) { 336 if (erasure_field == null) 337 erasure_field = types.erasure(type); 338 return erasure_field; 339 } 340 341 /** The external type of a symbol. This is the symbol's erased type 342 * except for constructors of inner classes which get the enclosing 343 * instance class added as first argument. 344 */ 345 public Type externalType(Types types) { 346 Type t = erasure(types); 347 if (name == name.table.names.init && owner.hasOuterInstance()) { 348 Type outerThisType = types.erasure(owner.type.getEnclosingType()); 349 return new MethodType(t.getParameterTypes().prepend(outerThisType), 350 t.getReturnType(), 351 t.getThrownTypes(), 352 t.tsym); 353 } else { 354 return t; 355 } 356 } 357 358 public boolean isDeprecated() { 359 return (flags_field & DEPRECATED) != 0; 360 } 361 362 public boolean isDeprecatableViaAnnotation() { 363 switch (getKind()) { 364 case LOCAL_VARIABLE: 365 case PACKAGE: 366 case PARAMETER: 367 case RESOURCE_VARIABLE: 368 case EXCEPTION_PARAMETER: 369 return false; 370 default: 371 return true; 372 } 373 } 374 375 public boolean isStatic() { 376 return 377 (flags() & STATIC) != 0 || 378 (owner.flags() & INTERFACE) != 0 && kind != MTH && 379 name != name.table.names._this; 380 } 381 382 public boolean isInterface() { 383 return (flags() & INTERFACE) != 0; 384 } 385 386 public boolean isPrivate() { 387 return (flags_field & Flags.AccessFlags) == PRIVATE; 388 } 389 390 public boolean isEnum() { 391 return (flags() & ENUM) != 0; 392 } 393 394 /** Is this symbol declared (directly or indirectly) local 395 * to a method or variable initializer? 396 * Also includes fields of inner classes which are in 397 * turn local to a method or variable initializer. 398 */ 399 public boolean isLocal() { 400 return 401 (owner.kind.matches(KindSelector.VAL_MTH) || 402 (owner.kind == TYP && owner.isLocal())); 403 } 404 405 /** Has this symbol an empty name? This includes anonymous 406 * inner classes. 407 */ 408 public boolean isAnonymous() { 409 return name.isEmpty(); 410 } 411 412 /** Is this symbol a constructor? 413 */ 414 public boolean isConstructor() { 415 return name == name.table.names.init; 416 } 417 418 /** The fully qualified name of this symbol. 419 * This is the same as the symbol's name except for class symbols, 420 * which are handled separately. 421 */ 422 public Name getQualifiedName() { 423 return name; 424 } 425 426 /** The fully qualified name of this symbol after converting to flat 427 * representation. This is the same as the symbol's name except for 428 * class symbols, which are handled separately. 429 */ 430 public Name flatName() { 431 return getQualifiedName(); 432 } 433 434 /** If this is a class or package, its members, otherwise null. 435 */ 436 public WriteableScope members() { 437 return null; 438 } 439 440 /** A class is an inner class if it it has an enclosing instance class. 441 */ 442 public boolean isInner() { 443 return kind == TYP && type.getEnclosingType().hasTag(CLASS); 444 } 445 446 /** An inner class has an outer instance if it is not an interface 447 * it has an enclosing instance class which might be referenced from the class. 448 * Nested classes can see instance members of their enclosing class. 449 * Their constructors carry an additional this$n parameter, inserted 450 * implicitly by the compiler. 451 * 452 * @see #isInner 453 */ 454 public boolean hasOuterInstance() { 455 return 456 type.getEnclosingType().hasTag(CLASS) && (flags() & (INTERFACE | NOOUTERTHIS)) == 0; 457 } 458 459 /** The closest enclosing class of this symbol's declaration. 460 * Warning: this (misnamed) method returns the receiver itself 461 * when the receiver is a class (as opposed to its enclosing 462 * class as one may be misled to believe.) 463 */ 464 public ClassSymbol enclClass() { 465 Symbol c = this; 466 while (c != null && 467 (!c.kind.matches(KindSelector.TYP) || !c.type.hasTag(CLASS))) { 468 c = c.owner; 469 } 470 return (ClassSymbol)c; 471 } 472 473 /** The outermost class which indirectly owns this symbol. 474 */ 475 public ClassSymbol outermostClass() { 476 Symbol sym = this; 477 Symbol prev = null; 478 while (sym.kind != PCK) { 479 prev = sym; 480 sym = sym.owner; 481 } 482 return (ClassSymbol) prev; 483 } 484 485 /** The package which indirectly owns this symbol. 486 */ 487 public PackageSymbol packge() { 488 Symbol sym = this; 489 while (sym.kind != PCK) { 490 sym = sym.owner; 491 } 492 return (PackageSymbol) sym; 493 } 494 495 /** Is this symbol a subclass of `base'? Only defined for ClassSymbols. 496 */ 497 public boolean isSubClass(Symbol base, Types types) { 498 throw new AssertionError("isSubClass " + this); 499 } 500 501 /** Fully check membership: hierarchy, protection, and hiding. 502 * Does not exclude methods not inherited due to overriding. 503 */ 504 public boolean isMemberOf(TypeSymbol clazz, Types types) { 505 return 506 owner == clazz || 507 clazz.isSubClass(owner, types) && 508 isInheritedIn(clazz, types) && 509 !hiddenIn((ClassSymbol)clazz, types); 510 } 511 512 /** Is this symbol the same as or enclosed by the given class? */ 513 public boolean isEnclosedBy(ClassSymbol clazz) { 514 for (Symbol sym = this; sym.kind != PCK; sym = sym.owner) 515 if (sym == clazz) return true; 516 return false; 517 } 518 519 private boolean hiddenIn(ClassSymbol clazz, Types types) { 520 Symbol sym = hiddenInInternal(clazz, types); 521 Assert.check(sym != null, "the result of hiddenInInternal() can't be null"); 522 /* If we find the current symbol then there is no symbol hiding it 523 */ 524 return sym != this; 525 } 526 527 /** This method looks in the supertypes graph that has the current class as the 528 * initial node, till it finds the current symbol or another symbol that hides it. 529 * If the current class has more than one supertype (extends one class and 530 * implements one or more interfaces) then null can be returned, meaning that 531 * a wrong path in the supertypes graph was selected. Null can only be returned 532 * as a temporary value, as a result of the recursive call. 533 */ 534 private Symbol hiddenInInternal(ClassSymbol currentClass, Types types) { 535 if (currentClass == owner) { 536 return this; 537 } 538 for (Symbol sym : currentClass.members().getSymbolsByName(name)) { 539 if (sym.kind == kind && 540 (kind != MTH || 541 (sym.flags() & STATIC) != 0 && 542 types.isSubSignature(sym.type, type))) { 543 return sym; 544 } 545 } 546 Symbol hiddenSym = null; 547 for (Type st : types.interfaces(currentClass.type) 548 .prepend(types.supertype(currentClass.type))) { 549 if (st != null && (st.hasTag(CLASS))) { 550 Symbol sym = hiddenInInternal((ClassSymbol)st.tsym, types); 551 if (sym == this) { 552 return this; 553 } else if (sym != null) { 554 hiddenSym = sym; 555 } 556 } 557 } 558 return hiddenSym; 559 } 560 561 /** Is this symbol inherited into a given class? 562 * PRE: If symbol's owner is a interface, 563 * it is already assumed that the interface is a superinterface 564 * of given class. 565 * @param clazz The class for which we want to establish membership. 566 * This must be a subclass of the member's owner. 567 */ 568 public boolean isInheritedIn(Symbol clazz, Types types) { 569 switch ((int)(flags_field & Flags.AccessFlags)) { 570 default: // error recovery 571 case PUBLIC: 572 return true; 573 case PRIVATE: 574 return this.owner == clazz; 575 case PROTECTED: 576 // we model interfaces as extending Object 577 return (clazz.flags() & INTERFACE) == 0; 578 case 0: 579 PackageSymbol thisPackage = this.packge(); 580 for (Symbol sup = clazz; 581 sup != null && sup != this.owner; 582 sup = types.supertype(sup.type).tsym) { 583 while (sup.type.hasTag(TYPEVAR)) 584 sup = sup.type.getUpperBound().tsym; 585 if (sup.type.isErroneous()) 586 return true; // error recovery 587 if ((sup.flags() & COMPOUND) != 0) 588 continue; 589 if (sup.packge() != thisPackage) 590 return false; 591 } 592 return (clazz.flags() & INTERFACE) == 0; 593 } 594 } 595 596 /** The (variable or method) symbol seen as a member of given 597 * class type`site' (this might change the symbol's type). 598 * This is used exclusively for producing diagnostics. 599 */ 600 public Symbol asMemberOf(Type site, Types types) { 601 throw new AssertionError(); 602 } 603 604 /** Does this method symbol override `other' symbol, when both are seen as 605 * members of class `origin'? It is assumed that _other is a member 606 * of origin. 607 * 608 * It is assumed that both symbols have the same name. The static 609 * modifier is ignored for this test. 610 * 611 * See JLS 8.4.6.1 (without transitivity) and 8.4.6.4 612 */ 613 public boolean overrides(Symbol _other, TypeSymbol origin, Types types, boolean checkResult) { 614 return false; 615 } 616 617 /** Complete the elaboration of this symbol's definition. 618 */ 619 public void complete() throws CompletionFailure { 620 if (completer != Completer.NULL_COMPLETER) { 621 Completer c = completer; 622 completer = Completer.NULL_COMPLETER; 623 c.complete(this); 624 } 625 } 626 627 /** True if the symbol represents an entity that exists. 628 */ 629 public boolean exists() { 630 return true; 631 } 632 633 @DefinedBy(Api.LANGUAGE_MODEL) 634 public Type asType() { 635 return type; 636 } 637 638 @DefinedBy(Api.LANGUAGE_MODEL) 639 public Symbol getEnclosingElement() { 640 return owner; 641 } 642 643 @DefinedBy(Api.LANGUAGE_MODEL) 644 public ElementKind getKind() { 645 return ElementKind.OTHER; // most unkind 646 } 647 648 @DefinedBy(Api.LANGUAGE_MODEL) 649 public Set<Modifier> getModifiers() { 650 return Flags.asModifierSet(flags()); 651 } 652 653 @DefinedBy(Api.LANGUAGE_MODEL) 654 public Name getSimpleName() { 655 return name; 656 } 657 658 /** 659 * This is the implementation for {@code 660 * javax.lang.model.element.Element.getAnnotationMirrors()}. 661 */ 662 @Override @DefinedBy(Api.LANGUAGE_MODEL) 663 public List<Attribute.Compound> getAnnotationMirrors() { 664 return getRawAttributes(); 665 } 666 667 668 // TODO: getEnclosedElements should return a javac List, fix in FilteredMemberList 669 @DefinedBy(Api.LANGUAGE_MODEL) 670 public java.util.List<Symbol> getEnclosedElements() { 671 return List.nil(); 672 } 673 674 public List<TypeVariableSymbol> getTypeParameters() { 675 ListBuffer<TypeVariableSymbol> l = new ListBuffer<>(); 676 for (Type t : type.getTypeArguments()) { 677 Assert.check(t.tsym.getKind() == ElementKind.TYPE_PARAMETER); 678 l.append((TypeVariableSymbol)t.tsym); 679 } 680 return l.toList(); 681 } 682 683 public static class DelegatedSymbol<T extends Symbol> extends Symbol { 684 protected T other; 685 public DelegatedSymbol(T other) { 686 super(other.kind, other.flags_field, other.name, other.type, other.owner); 687 this.other = other; 688 } 689 public String toString() { return other.toString(); } 690 public Symbol location() { return other.location(); } 691 public Symbol location(Type site, Types types) { return other.location(site, types); } 692 public Symbol baseSymbol() { return other; } 693 public Type erasure(Types types) { return other.erasure(types); } 694 public Type externalType(Types types) { return other.externalType(types); } 695 public boolean isLocal() { return other.isLocal(); } 696 public boolean isConstructor() { return other.isConstructor(); } 697 public Name getQualifiedName() { return other.getQualifiedName(); } 698 public Name flatName() { return other.flatName(); } 699 public WriteableScope members() { return other.members(); } 700 public boolean isInner() { return other.isInner(); } 701 public boolean hasOuterInstance() { return other.hasOuterInstance(); } 702 public ClassSymbol enclClass() { return other.enclClass(); } 703 public ClassSymbol outermostClass() { return other.outermostClass(); } 704 public PackageSymbol packge() { return other.packge(); } 705 public boolean isSubClass(Symbol base, Types types) { return other.isSubClass(base, types); } 706 public boolean isMemberOf(TypeSymbol clazz, Types types) { return other.isMemberOf(clazz, types); } 707 public boolean isEnclosedBy(ClassSymbol clazz) { return other.isEnclosedBy(clazz); } 708 public boolean isInheritedIn(Symbol clazz, Types types) { return other.isInheritedIn(clazz, types); } 709 public Symbol asMemberOf(Type site, Types types) { return other.asMemberOf(site, types); } 710 public void complete() throws CompletionFailure { other.complete(); } 711 712 @DefinedBy(Api.LANGUAGE_MODEL) 713 public <R, P> R accept(ElementVisitor<R, P> v, P p) { 714 return other.accept(v, p); 715 } 716 717 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) { 718 return v.visitSymbol(other, p); 719 } 720 721 public T getUnderlyingSymbol() { 722 return other; 723 } 724 } 725 726 /** A base class for Symbols representing types. 727 */ 728 public static abstract class TypeSymbol extends Symbol { 729 public TypeSymbol(Kind kind, long flags, Name name, Type type, Symbol owner) { 730 super(kind, flags, name, type, owner); 731 } 732 /** form a fully qualified name from a name and an owner 733 */ 734 static public Name formFullName(Name name, Symbol owner) { 735 if (owner == null) return name; 736 if ((owner.kind != ERR) && 737 (owner.kind.matches(KindSelector.VAL_MTH) || 738 (owner.kind == TYP && owner.type.hasTag(TYPEVAR)) 739 )) return name; 740 Name prefix = owner.getQualifiedName(); 741 if (prefix == null || prefix == prefix.table.names.empty) 742 return name; 743 else return prefix.append('.', name); 744 } 745 746 /** form a fully qualified name from a name and an owner, after 747 * converting to flat representation 748 */ 749 static public Name formFlatName(Name name, Symbol owner) { 750 if (owner == null || owner.kind.matches(KindSelector.VAL_MTH) || 751 (owner.kind == TYP && owner.type.hasTag(TYPEVAR)) 752 ) return name; 753 char sep = owner.kind == TYP ? '$' : '.'; 754 Name prefix = owner.flatName(); 755 if (prefix == null || prefix == prefix.table.names.empty) 756 return name; 757 else return prefix.append(sep, name); 758 } 759 760 /** 761 * A partial ordering between type symbols that refines the 762 * class inheritance graph. 763 * 764 * Type variables always precede other kinds of symbols. 765 */ 766 public final boolean precedes(TypeSymbol that, Types types) { 767 if (this == that) 768 return false; 769 if (type.hasTag(that.type.getTag())) { 770 if (type.hasTag(CLASS)) { 771 return 772 types.rank(that.type) < types.rank(this.type) || 773 types.rank(that.type) == types.rank(this.type) && 774 that.getQualifiedName().compareTo(this.getQualifiedName()) < 0; 775 } else if (type.hasTag(TYPEVAR)) { 776 return types.isSubtype(this.type, that.type); 777 } 778 } 779 return type.hasTag(TYPEVAR); 780 } 781 782 @Override @DefinedBy(Api.LANGUAGE_MODEL) 783 public java.util.List<Symbol> getEnclosedElements() { 784 List<Symbol> list = List.nil(); 785 if (kind == TYP && type.hasTag(TYPEVAR)) { 786 return list; 787 } 788 for (Symbol sym : members().getSymbols(NON_RECURSIVE)) { 789 try { 790 if (sym != null && (sym.flags() & SYNTHETIC) == 0 && sym.owner == this) { 791 list = list.prepend(sym); 792 } 793 } catch (BadEnclosingMethodAttr badEnclosingMethod) { 794 // ignore the exception 795 } 796 } 797 return list; 798 } 799 800 public AnnotationTypeMetadata getAnnotationTypeMetadata() { 801 Assert.error("Only on ClassSymbol"); 802 return null; //unreachable 803 } 804 805 public boolean isAnnotationType() { return false; } 806 807 @Override 808 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) { 809 return v.visitTypeSymbol(this, p); 810 } 811 } 812 813 /** 814 * Type variables are represented by instances of this class. 815 */ 816 public static class TypeVariableSymbol 817 extends TypeSymbol implements TypeParameterElement { 818 819 public TypeVariableSymbol(long flags, Name name, Type type, Symbol owner) { 820 super(TYP, flags, name, type, owner); 821 } 822 823 @DefinedBy(Api.LANGUAGE_MODEL) 824 public ElementKind getKind() { 825 return ElementKind.TYPE_PARAMETER; 826 } 827 828 @Override @DefinedBy(Api.LANGUAGE_MODEL) 829 public Symbol getGenericElement() { 830 return owner; 831 } 832 833 @DefinedBy(Api.LANGUAGE_MODEL) 834 public List<Type> getBounds() { 835 TypeVar t = (TypeVar)type; 836 Type bound = t.getUpperBound(); 837 if (!bound.isCompound()) 838 return List.of(bound); 839 ClassType ct = (ClassType)bound; 840 if (!ct.tsym.erasure_field.isInterface()) { 841 return ct.interfaces_field.prepend(ct.supertype_field); 842 } else { 843 // No superclass was given in bounds. 844 // In this case, supertype is Object, erasure is first interface. 845 return ct.interfaces_field; 846 } 847 } 848 849 @Override @DefinedBy(Api.LANGUAGE_MODEL) 850 public List<Attribute.Compound> getAnnotationMirrors() { 851 // Declaration annotations on type variables are stored in type attributes 852 // on the owner of the TypeVariableSymbol 853 List<Attribute.TypeCompound> candidates = owner.getRawTypeAttributes(); 854 int index = owner.getTypeParameters().indexOf(this); 855 List<Attribute.Compound> res = List.nil(); 856 for (Attribute.TypeCompound a : candidates) { 857 if (isCurrentSymbolsAnnotation(a, index)) 858 res = res.prepend(a); 859 } 860 861 return res.reverse(); 862 } 863 864 // Helper to getAnnotation[s] 865 @Override 866 public <A extends Annotation> Attribute.Compound getAttribute(Class<A> annoType) { 867 String name = annoType.getName(); 868 869 // Declaration annotations on type variables are stored in type attributes 870 // on the owner of the TypeVariableSymbol 871 List<Attribute.TypeCompound> candidates = owner.getRawTypeAttributes(); 872 int index = owner.getTypeParameters().indexOf(this); 873 for (Attribute.TypeCompound anno : candidates) 874 if (isCurrentSymbolsAnnotation(anno, index) && 875 name.contentEquals(anno.type.tsym.flatName())) 876 return anno; 877 878 return null; 879 } 880 //where: 881 boolean isCurrentSymbolsAnnotation(Attribute.TypeCompound anno, int index) { 882 return (anno.position.type == TargetType.CLASS_TYPE_PARAMETER || 883 anno.position.type == TargetType.METHOD_TYPE_PARAMETER) && 884 anno.position.parameter_index == index; 885 } 886 887 888 @Override @DefinedBy(Api.LANGUAGE_MODEL) 889 public <R, P> R accept(ElementVisitor<R, P> v, P p) { 890 return v.visitTypeParameter(this, p); 891 } 892 } 893 /** A class for module symbols. 894 */ 895 public static class ModuleSymbol extends TypeSymbol 896 implements ModuleElement { 897 898 public Name version; 899 public JavaFileManager.Location sourceLocation; 900 public JavaFileManager.Location classLocation; 901 902 /** All directives, in natural order. */ 903 public List<com.sun.tools.javac.code.Directive> directives; 904 public List<com.sun.tools.javac.code.Directive.RequiresDirective> requires; 905 public List<com.sun.tools.javac.code.Directive.ExportsDirective> exports; 906 public List<com.sun.tools.javac.code.Directive.ProvidesDirective> provides; 907 public List<com.sun.tools.javac.code.Directive.UsesDirective> uses; 908 909 public ClassSymbol module_info; 910 911 public PackageSymbol unnamedPackage; 912 public Map<Name, PackageSymbol> visiblePackages; 913 public List<Symbol> enclosedPackages = List.nil(); 914 915 public Completer usesProvidesCompleter = Completer.NULL_COMPLETER; 916 917 /** 918 * Create a ModuleSymbol with an associated module-info ClassSymbol. 919 * The name of the module may be null, if it is not known yet. 920 */ 921 public static ModuleSymbol create(Name name, Name module_info) { 922 ModuleSymbol msym = new ModuleSymbol(name, null); 923 ClassSymbol info = new ClassSymbol(Flags.MODULE, module_info, msym); 924 info.fullname = formFullName(module_info, msym); 925 info.flatname = info.fullname; 926 info.members_field = WriteableScope.create(info); 927 msym.module_info = info; 928 return msym; 929 } 930 931 public ModuleSymbol(Name name, Symbol owner) { 932 super(MDL, 0, name, null, owner); 933 this.type = new ModuleType(this); 934 } 935 936 @Override @DefinedBy(Api.LANGUAGE_MODEL) 937 public boolean isUnnamed() { 938 return name.isEmpty() && owner == null; 939 } 940 941 public boolean isNoModule() { 942 return false; 943 } 944 945 @Override @DefinedBy(Api.LANGUAGE_MODEL) 946 public ElementKind getKind() { 947 return ElementKind.MODULE; 948 } 949 950 @Override @DefinedBy(Api.LANGUAGE_MODEL) 951 public java.util.List<Directive> getDirectives() { 952 completeUsesProvides(); 953 return Collections.unmodifiableList(directives); 954 } 955 956 public void completeUsesProvides() { 957 if (usesProvidesCompleter != Completer.NULL_COMPLETER) { 958 Completer c = usesProvidesCompleter; 959 usesProvidesCompleter = Completer.NULL_COMPLETER; 960 c.complete(this); 961 } 962 } 963 964 @Override 965 public ClassSymbol outermostClass() { 966 return null; 967 } 968 969 @Override 970 public String toString() { 971 // TODO: the following strings should be localized 972 // Do this with custom anon subtypes in Symtab 973 String n = (name == null) ? "<unknown>" 974 : (name.isEmpty()) ? "<unnamed>" 975 : String.valueOf(name); 976 return n; 977 } 978 979 @Override @DefinedBy(Api.LANGUAGE_MODEL) 980 public <R, P> R accept(ElementVisitor<R, P> v, P p) { 981 return v.visitModule(this, p); 982 } 983 984 @Override @DefinedBy(Api.LANGUAGE_MODEL) 985 public List<Symbol> getEnclosedElements() { 986 List<Symbol> list = List.nil(); 987 for (Symbol sym : enclosedPackages) { 988 if (sym.members().anyMatch(m -> m.kind == TYP)) 989 list = list.prepend(sym); 990 } 991 return list; 992 } 993 994 public void reset() { 995 this.directives = null; 996 this.requires = null; 997 this.exports = null; 998 this.provides = null; 999 this.uses = null; 1000 this.visiblePackages = null; 1001 } 1002 1003 } 1004 1005 /** A class for package symbols 1006 */ 1007 public static class PackageSymbol extends TypeSymbol 1008 implements PackageElement { 1009 1010 public WriteableScope members_field; 1011 public Name fullname; 1012 public ClassSymbol package_info; // see bug 6443073 1013 public ModuleSymbol modle; 1014 1015 public PackageSymbol(Name name, Type type, Symbol owner) { 1016 super(PCK, 0, name, type, owner); 1017 this.members_field = null; 1018 this.fullname = formFullName(name, owner); 1019 } 1020 1021 public PackageSymbol(Name name, Symbol owner) { 1022 this(name, null, owner); 1023 this.type = new PackageType(this); 1024 } 1025 1026 public String toString() { 1027 return fullname.toString(); 1028 } 1029 1030 @DefinedBy(Api.LANGUAGE_MODEL) 1031 public Name getQualifiedName() { 1032 return fullname; 1033 } 1034 1035 @DefinedBy(Api.LANGUAGE_MODEL) 1036 public boolean isUnnamed() { 1037 return name.isEmpty() && owner != null; 1038 } 1039 1040 public WriteableScope members() { 1041 complete(); 1042 return members_field; 1043 } 1044 1045 public long flags() { 1046 complete(); 1047 return flags_field; 1048 } 1049 1050 @Override 1051 public List<Attribute.Compound> getRawAttributes() { 1052 complete(); 1053 if (package_info != null) { 1054 package_info.complete(); 1055 mergeAttributes(); 1056 } 1057 return super.getRawAttributes(); 1058 } 1059 1060 private void mergeAttributes() { 1061 if (metadata == null && 1062 package_info.metadata != null) { 1063 metadata = new SymbolMetadata(this); 1064 metadata.setAttributes(package_info.metadata); 1065 } 1066 } 1067 1068 /** A package "exists" if a type or package that exists has 1069 * been seen within it. 1070 */ 1071 public boolean exists() { 1072 return (flags_field & EXISTS) != 0; 1073 } 1074 1075 @DefinedBy(Api.LANGUAGE_MODEL) 1076 public ElementKind getKind() { 1077 return ElementKind.PACKAGE; 1078 } 1079 1080 @DefinedBy(Api.LANGUAGE_MODEL) 1081 public Symbol getEnclosingElement() { 1082 return modle != null && !modle.isNoModule() ? modle : null; 1083 } 1084 1085 @DefinedBy(Api.LANGUAGE_MODEL) 1086 public <R, P> R accept(ElementVisitor<R, P> v, P p) { 1087 return v.visitPackage(this, p); 1088 } 1089 1090 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) { 1091 return v.visitPackageSymbol(this, p); 1092 } 1093 1094 /**Resets the Symbol into the state good for next round of annotation processing.*/ 1095 public void reset() { 1096 metadata = null; 1097 } 1098 1099 } 1100 1101 /** A class for class symbols 1102 */ 1103 public static class ClassSymbol extends TypeSymbol implements TypeElement { 1104 1105 /** a scope for all class members; variables, methods and inner classes 1106 * type parameters are not part of this scope 1107 */ 1108 public WriteableScope members_field; 1109 1110 /** the fully qualified name of the class, i.e. pck.outer.inner. 1111 * null for anonymous classes 1112 */ 1113 public Name fullname; 1114 1115 /** the fully qualified name of the class after converting to flat 1116 * representation, i.e. pck.outer$inner, 1117 * set externally for local and anonymous classes 1118 */ 1119 public Name flatname; 1120 1121 /** the sourcefile where the class came from 1122 */ 1123 public JavaFileObject sourcefile; 1124 1125 /** the classfile from where to load this class 1126 * this will have extension .class or .java 1127 */ 1128 public JavaFileObject classfile; 1129 1130 /** the list of translated local classes (used for generating 1131 * InnerClasses attribute) 1132 */ 1133 public List<ClassSymbol> trans_local; 1134 1135 /** the constant pool of the class 1136 */ 1137 public Pool pool; 1138 1139 /** the annotation metadata attached to this class */ 1140 private AnnotationTypeMetadata annotationTypeMetadata; 1141 1142 public ClassSymbol(long flags, Name name, Type type, Symbol owner) { 1143 super(TYP, flags, name, type, owner); 1144 this.members_field = null; 1145 this.fullname = formFullName(name, owner); 1146 this.flatname = formFlatName(name, owner); 1147 this.sourcefile = null; 1148 this.classfile = null; 1149 this.pool = null; 1150 this.annotationTypeMetadata = AnnotationTypeMetadata.notAnAnnotationType(); 1151 } 1152 1153 public ClassSymbol(long flags, Name name, Symbol owner) { 1154 this( 1155 flags, 1156 name, 1157 new ClassType(Type.noType, null, null), 1158 owner); 1159 this.type.tsym = this; 1160 } 1161 1162 /** The Java source which this symbol represents. 1163 */ 1164 public String toString() { 1165 return className(); 1166 } 1167 1168 public long flags() { 1169 complete(); 1170 return flags_field; 1171 } 1172 1173 public WriteableScope members() { 1174 complete(); 1175 return members_field; 1176 } 1177 1178 @Override 1179 public List<Attribute.Compound> getRawAttributes() { 1180 complete(); 1181 return super.getRawAttributes(); 1182 } 1183 1184 @Override 1185 public List<Attribute.TypeCompound> getRawTypeAttributes() { 1186 complete(); 1187 return super.getRawTypeAttributes(); 1188 } 1189 1190 public Type erasure(Types types) { 1191 if (erasure_field == null) 1192 erasure_field = new ClassType(types.erasure(type.getEnclosingType()), 1193 List.<Type>nil(), this, 1194 type.getMetadata()); 1195 return erasure_field; 1196 } 1197 1198 public String className() { 1199 if (name.isEmpty()) 1200 return 1201 Log.getLocalizedString("anonymous.class", flatname); 1202 else 1203 return fullname.toString(); 1204 } 1205 1206 @DefinedBy(Api.LANGUAGE_MODEL) 1207 public Name getQualifiedName() { 1208 return fullname; 1209 } 1210 1211 public Name flatName() { 1212 return flatname; 1213 } 1214 1215 public boolean isSubClass(Symbol base, Types types) { 1216 if (this == base) { 1217 return true; 1218 } else if ((base.flags() & INTERFACE) != 0) { 1219 for (Type t = type; t.hasTag(CLASS); t = types.supertype(t)) 1220 for (List<Type> is = types.interfaces(t); 1221 is.nonEmpty(); 1222 is = is.tail) 1223 if (is.head.tsym.isSubClass(base, types)) return true; 1224 } else { 1225 for (Type t = type; t.hasTag(CLASS); t = types.supertype(t)) 1226 if (t.tsym == base) return true; 1227 } 1228 return false; 1229 } 1230 1231 /** Complete the elaboration of this symbol's definition. 1232 */ 1233 public void complete() throws CompletionFailure { 1234 try { 1235 super.complete(); 1236 } catch (CompletionFailure ex) { 1237 // quiet error recovery 1238 flags_field |= (PUBLIC|STATIC); 1239 this.type = new ErrorType(this, Type.noType); 1240 throw ex; 1241 } 1242 } 1243 1244 @DefinedBy(Api.LANGUAGE_MODEL) 1245 public List<Type> getInterfaces() { 1246 complete(); 1247 if (type instanceof ClassType) { 1248 ClassType t = (ClassType)type; 1249 if (t.interfaces_field == null) // FIXME: shouldn't be null 1250 t.interfaces_field = List.nil(); 1251 if (t.all_interfaces_field != null) 1252 return Type.getModelTypes(t.all_interfaces_field); 1253 return t.interfaces_field; 1254 } else { 1255 return List.nil(); 1256 } 1257 } 1258 1259 @DefinedBy(Api.LANGUAGE_MODEL) 1260 public Type getSuperclass() { 1261 complete(); 1262 if (type instanceof ClassType) { 1263 ClassType t = (ClassType)type; 1264 if (t.supertype_field == null) // FIXME: shouldn't be null 1265 t.supertype_field = Type.noType; 1266 // An interface has no superclass; its supertype is Object. 1267 return t.isInterface() 1268 ? Type.noType 1269 : t.supertype_field.getModelType(); 1270 } else { 1271 return Type.noType; 1272 } 1273 } 1274 1275 /** 1276 * Returns the next class to search for inherited annotations or {@code null} 1277 * if the next class can't be found. 1278 */ 1279 private ClassSymbol getSuperClassToSearchForAnnotations() { 1280 1281 Type sup = getSuperclass(); 1282 1283 if (!sup.hasTag(CLASS) || sup.isErroneous()) 1284 return null; 1285 1286 return (ClassSymbol) sup.tsym; 1287 } 1288 1289 1290 @Override 1291 protected <A extends Annotation> A[] getInheritedAnnotations(Class<A> annoType) { 1292 1293 ClassSymbol sup = getSuperClassToSearchForAnnotations(); 1294 1295 return sup == null ? super.getInheritedAnnotations(annoType) 1296 : sup.getAnnotationsByType(annoType); 1297 } 1298 1299 1300 @DefinedBy(Api.LANGUAGE_MODEL) 1301 public ElementKind getKind() { 1302 long flags = flags(); 1303 if ((flags & ANNOTATION) != 0) 1304 return ElementKind.ANNOTATION_TYPE; 1305 else if ((flags & INTERFACE) != 0) 1306 return ElementKind.INTERFACE; 1307 else if ((flags & ENUM) != 0) 1308 return ElementKind.ENUM; 1309 else 1310 return ElementKind.CLASS; 1311 } 1312 1313 @Override @DefinedBy(Api.LANGUAGE_MODEL) 1314 public Set<Modifier> getModifiers() { 1315 long flags = flags(); 1316 return Flags.asModifierSet(flags & ~DEFAULT); 1317 } 1318 1319 @DefinedBy(Api.LANGUAGE_MODEL) 1320 public NestingKind getNestingKind() { 1321 complete(); 1322 if (owner.kind == PCK) 1323 return NestingKind.TOP_LEVEL; 1324 else if (name.isEmpty()) 1325 return NestingKind.ANONYMOUS; 1326 else if (owner.kind == MTH) 1327 return NestingKind.LOCAL; 1328 else 1329 return NestingKind.MEMBER; 1330 } 1331 1332 1333 @Override 1334 protected <A extends Annotation> Attribute.Compound getAttribute(final Class<A> annoType) { 1335 1336 Attribute.Compound attrib = super.getAttribute(annoType); 1337 1338 boolean inherited = annoType.isAnnotationPresent(Inherited.class); 1339 if (attrib != null || !inherited) 1340 return attrib; 1341 1342 // Search supertypes 1343 ClassSymbol superType = getSuperClassToSearchForAnnotations(); 1344 return superType == null ? null 1345 : superType.getAttribute(annoType); 1346 } 1347 1348 1349 1350 1351 @DefinedBy(Api.LANGUAGE_MODEL) 1352 public <R, P> R accept(ElementVisitor<R, P> v, P p) { 1353 return v.visitType(this, p); 1354 } 1355 1356 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) { 1357 return v.visitClassSymbol(this, p); 1358 } 1359 1360 public void markAbstractIfNeeded(Types types) { 1361 if (types.enter.getEnv(this) != null && 1362 (flags() & ENUM) != 0 && types.supertype(type).tsym == types.syms.enumSym && 1363 (flags() & (FINAL | ABSTRACT)) == 0) { 1364 if (types.firstUnimplementedAbstract(this) != null) 1365 // add the ABSTRACT flag to an enum 1366 flags_field |= ABSTRACT; 1367 } 1368 } 1369 1370 /**Resets the Symbol into the state good for next round of annotation processing.*/ 1371 public void reset() { 1372 kind = TYP; 1373 erasure_field = null; 1374 members_field = null; 1375 flags_field = 0; 1376 if (type instanceof ClassType) { 1377 ClassType t = (ClassType)type; 1378 t.setEnclosingType(Type.noType); 1379 t.rank_field = -1; 1380 t.typarams_field = null; 1381 t.allparams_field = null; 1382 t.supertype_field = null; 1383 t.interfaces_field = null; 1384 t.all_interfaces_field = null; 1385 } 1386 clearAnnotationMetadata(); 1387 } 1388 1389 public void clearAnnotationMetadata() { 1390 metadata = null; 1391 annotationTypeMetadata = AnnotationTypeMetadata.notAnAnnotationType(); 1392 } 1393 1394 @Override 1395 public AnnotationTypeMetadata getAnnotationTypeMetadata() { 1396 return annotationTypeMetadata; 1397 } 1398 1399 @Override 1400 public boolean isAnnotationType() { 1401 return (flags_field & Flags.ANNOTATION) != 0; 1402 } 1403 1404 public void setAnnotationTypeMetadata(AnnotationTypeMetadata a) { 1405 Assert.checkNonNull(a); 1406 Assert.check(!annotationTypeMetadata.isMetadataForAnnotationType()); 1407 this.annotationTypeMetadata = a; 1408 } 1409 } 1410 1411 1412 /** A class for variable symbols 1413 */ 1414 public static class VarSymbol extends Symbol implements VariableElement { 1415 1416 /** The variable's declaration position. 1417 */ 1418 public int pos = Position.NOPOS; 1419 1420 /** The variable's address. Used for different purposes during 1421 * flow analysis, translation and code generation. 1422 * Flow analysis: 1423 * If this is a blank final or local variable, its sequence number. 1424 * Translation: 1425 * If this is a private field, its access number. 1426 * Code generation: 1427 * If this is a local variable, its logical slot number. 1428 */ 1429 public int adr = -1; 1430 1431 /** Construct a variable symbol, given its flags, name, type and owner. 1432 */ 1433 public VarSymbol(long flags, Name name, Type type, Symbol owner) { 1434 super(VAR, flags, name, type, owner); 1435 } 1436 1437 /** Clone this symbol with new owner. 1438 */ 1439 public VarSymbol clone(Symbol newOwner) { 1440 VarSymbol v = new VarSymbol(flags_field, name, type, newOwner) { 1441 @Override 1442 public Symbol baseSymbol() { 1443 return VarSymbol.this; 1444 } 1445 }; 1446 v.pos = pos; 1447 v.adr = adr; 1448 v.data = data; 1449// System.out.println("clone " + v + " in " + newOwner);//DEBUG 1450 return v; 1451 } 1452 1453 public String toString() { 1454 return name.toString(); 1455 } 1456 1457 public Symbol asMemberOf(Type site, Types types) { 1458 return new VarSymbol(flags_field, name, types.memberType(site, this), owner); 1459 } 1460 1461 @DefinedBy(Api.LANGUAGE_MODEL) 1462 public ElementKind getKind() { 1463 long flags = flags(); 1464 if ((flags & PARAMETER) != 0) { 1465 if (isExceptionParameter()) 1466 return ElementKind.EXCEPTION_PARAMETER; 1467 else 1468 return ElementKind.PARAMETER; 1469 } else if ((flags & ENUM) != 0) { 1470 return ElementKind.ENUM_CONSTANT; 1471 } else if (owner.kind == TYP || owner.kind == ERR) { 1472 return ElementKind.FIELD; 1473 } else if (isResourceVariable()) { 1474 return ElementKind.RESOURCE_VARIABLE; 1475 } else { 1476 return ElementKind.LOCAL_VARIABLE; 1477 } 1478 } 1479 1480 @DefinedBy(Api.LANGUAGE_MODEL) 1481 public <R, P> R accept(ElementVisitor<R, P> v, P p) { 1482 return v.visitVariable(this, p); 1483 } 1484 1485 @DefinedBy(Api.LANGUAGE_MODEL) 1486 public Object getConstantValue() { // Mirror API 1487 return Constants.decode(getConstValue(), type); 1488 } 1489 1490 public void setLazyConstValue(final Env<AttrContext> env, 1491 final Attr attr, 1492 final JCVariableDecl variable) 1493 { 1494 setData(new Callable<Object>() { 1495 public Object call() { 1496 return attr.attribLazyConstantValue(env, variable, type); 1497 } 1498 }); 1499 } 1500 1501 /** 1502 * The variable's constant value, if this is a constant. 1503 * Before the constant value is evaluated, it points to an 1504 * initializer environment. If this is not a constant, it can 1505 * be used for other stuff. 1506 */ 1507 private Object data; 1508 1509 public boolean isExceptionParameter() { 1510 return data == ElementKind.EXCEPTION_PARAMETER; 1511 } 1512 1513 public boolean isResourceVariable() { 1514 return data == ElementKind.RESOURCE_VARIABLE; 1515 } 1516 1517 public Object getConstValue() { 1518 // TODO: Consider if getConstValue and getConstantValue can be collapsed 1519 if (data == ElementKind.EXCEPTION_PARAMETER || 1520 data == ElementKind.RESOURCE_VARIABLE) { 1521 return null; 1522 } else if (data instanceof Callable<?>) { 1523 // In this case, this is a final variable, with an as 1524 // yet unevaluated initializer. 1525 Callable<?> eval = (Callable<?>)data; 1526 data = null; // to make sure we don't evaluate this twice. 1527 try { 1528 data = eval.call(); 1529 } catch (Exception ex) { 1530 throw new AssertionError(ex); 1531 } 1532 } 1533 return data; 1534 } 1535 1536 public void setData(Object data) { 1537 Assert.check(!(data instanceof Env<?>), this); 1538 this.data = data; 1539 } 1540 1541 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) { 1542 return v.visitVarSymbol(this, p); 1543 } 1544 } 1545 1546 /** A class for method symbols. 1547 */ 1548 public static class MethodSymbol extends Symbol implements ExecutableElement { 1549 1550 /** The code of the method. */ 1551 public Code code = null; 1552 1553 /** The extra (synthetic/mandated) parameters of the method. */ 1554 public List<VarSymbol> extraParams = List.nil(); 1555 1556 /** The captured local variables in an anonymous class */ 1557 public List<VarSymbol> capturedLocals = List.nil(); 1558 1559 /** The parameters of the method. */ 1560 public List<VarSymbol> params = null; 1561 1562 /** The names of the parameters */ 1563 public List<Name> savedParameterNames; 1564 1565 /** For an annotation type element, its default value if any. 1566 * The value is null if none appeared in the method 1567 * declaration. 1568 */ 1569 public Attribute defaultValue = null; 1570 1571 /** Construct a method symbol, given its flags, name, type and owner. 1572 */ 1573 public MethodSymbol(long flags, Name name, Type type, Symbol owner) { 1574 super(MTH, flags, name, type, owner); 1575 if (owner.type.hasTag(TYPEVAR)) Assert.error(owner + "." + name); 1576 } 1577 1578 /** Clone this symbol with new owner. 1579 */ 1580 public MethodSymbol clone(Symbol newOwner) { 1581 MethodSymbol m = new MethodSymbol(flags_field, name, type, newOwner) { 1582 @Override 1583 public Symbol baseSymbol() { 1584 return MethodSymbol.this; 1585 } 1586 }; 1587 m.code = code; 1588 return m; 1589 } 1590 1591 @Override @DefinedBy(Api.LANGUAGE_MODEL) 1592 public Set<Modifier> getModifiers() { 1593 long flags = flags(); 1594 return Flags.asModifierSet((flags & DEFAULT) != 0 ? flags & ~ABSTRACT : flags); 1595 } 1596 1597 /** The Java source which this symbol represents. 1598 */ 1599 public String toString() { 1600 if ((flags() & BLOCK) != 0) { 1601 return owner.name.toString(); 1602 } else { 1603 String s = (name == name.table.names.init) 1604 ? owner.name.toString() 1605 : name.toString(); 1606 if (type != null) { 1607 if (type.hasTag(FORALL)) 1608 s = "<" + ((ForAll)type).getTypeArguments() + ">" + s; 1609 s += "(" + type.argtypes((flags() & VARARGS) != 0) + ")"; 1610 } 1611 return s; 1612 } 1613 } 1614 1615 public boolean isDynamic() { 1616 return false; 1617 } 1618 1619 /** find a symbol that this (proxy method) symbol implements. 1620 * @param c The class whose members are searched for 1621 * implementations 1622 */ 1623 public Symbol implemented(TypeSymbol c, Types types) { 1624 Symbol impl = null; 1625 for (List<Type> is = types.interfaces(c.type); 1626 impl == null && is.nonEmpty(); 1627 is = is.tail) { 1628 TypeSymbol i = is.head.tsym; 1629 impl = implementedIn(i, types); 1630 if (impl == null) 1631 impl = implemented(i, types); 1632 } 1633 return impl; 1634 } 1635 1636 public Symbol implementedIn(TypeSymbol c, Types types) { 1637 Symbol impl = null; 1638 for (Symbol sym : c.members().getSymbolsByName(name)) { 1639 if (this.overrides(sym, (TypeSymbol)owner, types, true) && 1640 // FIXME: I suspect the following requires a 1641 // subst() for a parametric return type. 1642 types.isSameType(type.getReturnType(), 1643 types.memberType(owner.type, sym).getReturnType())) { 1644 impl = sym; 1645 } 1646 } 1647 return impl; 1648 } 1649 1650 /** Will the erasure of this method be considered by the VM to 1651 * override the erasure of the other when seen from class `origin'? 1652 */ 1653 public boolean binaryOverrides(Symbol _other, TypeSymbol origin, Types types) { 1654 if (isConstructor() || _other.kind != MTH) return false; 1655 1656 if (this == _other) return true; 1657 MethodSymbol other = (MethodSymbol)_other; 1658 1659 // check for a direct implementation 1660 if (other.isOverridableIn((TypeSymbol)owner) && 1661 types.asSuper(owner.type, other.owner) != null && 1662 types.isSameType(erasure(types), other.erasure(types))) 1663 return true; 1664 1665 // check for an inherited implementation 1666 return 1667 (flags() & ABSTRACT) == 0 && 1668 other.isOverridableIn(origin) && 1669 this.isMemberOf(origin, types) && 1670 types.isSameType(erasure(types), other.erasure(types)); 1671 } 1672 1673 /** The implementation of this (abstract) symbol in class origin, 1674 * from the VM's point of view, null if method does not have an 1675 * implementation in class. 1676 * @param origin The class of which the implementation is a member. 1677 */ 1678 public MethodSymbol binaryImplementation(ClassSymbol origin, Types types) { 1679 for (TypeSymbol c = origin; c != null; c = types.supertype(c.type).tsym) { 1680 for (Symbol sym : c.members().getSymbolsByName(name)) { 1681 if (sym.kind == MTH && 1682 ((MethodSymbol)sym).binaryOverrides(this, origin, types)) 1683 return (MethodSymbol)sym; 1684 } 1685 } 1686 return null; 1687 } 1688 1689 /** Does this symbol override `other' symbol, when both are seen as 1690 * members of class `origin'? It is assumed that _other is a member 1691 * of origin. 1692 * 1693 * It is assumed that both symbols have the same name. The static 1694 * modifier is ignored for this test. 1695 * 1696 * A quirk in the works is that if the receiver is a method symbol for 1697 * an inherited abstract method we answer false summarily all else being 1698 * immaterial. Abstract "own" methods (i.e `this' is a direct member of 1699 * origin) don't get rejected as summarily and are put to test against the 1700 * suitable criteria. 1701 * 1702 * See JLS 8.4.6.1 (without transitivity) and 8.4.6.4 1703 */ 1704 public boolean overrides(Symbol _other, TypeSymbol origin, Types types, boolean checkResult) { 1705 return overrides(_other, origin, types, checkResult, true); 1706 } 1707 1708 /** Does this symbol override `other' symbol, when both are seen as 1709 * members of class `origin'? It is assumed that _other is a member 1710 * of origin. 1711 * 1712 * Caveat: If `this' is an abstract inherited member of origin, it is 1713 * deemed to override `other' only when `requireConcreteIfInherited' 1714 * is false. 1715 * 1716 * It is assumed that both symbols have the same name. The static 1717 * modifier is ignored for this test. 1718 * 1719 * See JLS 8.4.6.1 (without transitivity) and 8.4.6.4 1720 */ 1721 public boolean overrides(Symbol _other, TypeSymbol origin, Types types, boolean checkResult, 1722 boolean requireConcreteIfInherited) { 1723 if (isConstructor() || _other.kind != MTH) return false; 1724 1725 if (this == _other) return true; 1726 MethodSymbol other = (MethodSymbol)_other; 1727 1728 // check for a direct implementation 1729 if (other.isOverridableIn((TypeSymbol)owner) && 1730 types.asSuper(owner.type, other.owner) != null) { 1731 Type mt = types.memberType(owner.type, this); 1732 Type ot = types.memberType(owner.type, other); 1733 if (types.isSubSignature(mt, ot)) { 1734 if (!checkResult) 1735 return true; 1736 if (types.returnTypeSubstitutable(mt, ot)) 1737 return true; 1738 } 1739 } 1740 1741 // check for an inherited implementation 1742 if (((flags() & ABSTRACT) != 0 && requireConcreteIfInherited) || 1743 ((other.flags() & ABSTRACT) == 0 && (other.flags() & DEFAULT) == 0) || 1744 !other.isOverridableIn(origin) || 1745 !this.isMemberOf(origin, types)) 1746 return false; 1747 1748 // assert types.asSuper(origin.type, other.owner) != null; 1749 Type mt = types.memberType(origin.type, this); 1750 Type ot = types.memberType(origin.type, other); 1751 return 1752 types.isSubSignature(mt, ot) && 1753 (!checkResult || types.resultSubtype(mt, ot, types.noWarnings)); 1754 } 1755 1756 private boolean isOverridableIn(TypeSymbol origin) { 1757 // JLS 8.4.6.1 1758 switch ((int)(flags_field & Flags.AccessFlags)) { 1759 case Flags.PRIVATE: 1760 return false; 1761 case Flags.PUBLIC: 1762 return !this.owner.isInterface() || 1763 (flags_field & STATIC) == 0; 1764 case Flags.PROTECTED: 1765 return (origin.flags() & INTERFACE) == 0; 1766 case 0: 1767 // for package private: can only override in the same 1768 // package 1769 return 1770 this.packge() == origin.packge() && 1771 (origin.flags() & INTERFACE) == 0; 1772 default: 1773 return false; 1774 } 1775 } 1776 1777 @Override 1778 public boolean isInheritedIn(Symbol clazz, Types types) { 1779 switch ((int)(flags_field & Flags.AccessFlags)) { 1780 case PUBLIC: 1781 return !this.owner.isInterface() || 1782 clazz == owner || 1783 (flags_field & STATIC) == 0; 1784 default: 1785 return super.isInheritedIn(clazz, types); 1786 } 1787 } 1788 1789 public boolean isLambdaMethod() { 1790 return (flags() & LAMBDA_METHOD) == LAMBDA_METHOD; 1791 } 1792 1793 /** The implementation of this (abstract) symbol in class origin; 1794 * null if none exists. Synthetic methods are not considered 1795 * as possible implementations. 1796 */ 1797 public MethodSymbol implementation(TypeSymbol origin, Types types, boolean checkResult) { 1798 return implementation(origin, types, checkResult, implementation_filter); 1799 } 1800 // where 1801 public static final Filter<Symbol> implementation_filter = new Filter<Symbol>() { 1802 public boolean accepts(Symbol s) { 1803 return s.kind == MTH && 1804 (s.flags() & SYNTHETIC) == 0; 1805 } 1806 }; 1807 1808 public MethodSymbol implementation(TypeSymbol origin, Types types, boolean checkResult, Filter<Symbol> implFilter) { 1809 MethodSymbol res = types.implementation(this, origin, checkResult, implFilter); 1810 if (res != null) 1811 return res; 1812 // if origin is derived from a raw type, we might have missed 1813 // an implementation because we do not know enough about instantiations. 1814 // in this case continue with the supertype as origin. 1815 if (types.isDerivedRaw(origin.type) && !origin.isInterface()) 1816 return implementation(types.supertype(origin.type).tsym, types, checkResult); 1817 else 1818 return null; 1819 } 1820 1821 public List<VarSymbol> params() { 1822 owner.complete(); 1823 if (params == null) { 1824 // If ClassReader.saveParameterNames has been set true, then 1825 // savedParameterNames will be set to a list of names that 1826 // matches the types in type.getParameterTypes(). If any names 1827 // were not found in the class file, those names in the list will 1828 // be set to the empty name. 1829 // If ClassReader.saveParameterNames has been set false, then 1830 // savedParameterNames will be null. 1831 List<Name> paramNames = savedParameterNames; 1832 savedParameterNames = null; 1833 // discard the provided names if the list of names is the wrong size. 1834 if (paramNames == null || paramNames.size() != type.getParameterTypes().size()) { 1835 paramNames = List.nil(); 1836 } 1837 ListBuffer<VarSymbol> buf = new ListBuffer<>(); 1838 List<Name> remaining = paramNames; 1839 // assert: remaining and paramNames are both empty or both 1840 // have same cardinality as type.getParameterTypes() 1841 int i = 0; 1842 for (Type t : type.getParameterTypes()) { 1843 Name paramName; 1844 if (remaining.isEmpty()) { 1845 // no names for any parameters available 1846 paramName = createArgName(i, paramNames); 1847 } else { 1848 paramName = remaining.head; 1849 remaining = remaining.tail; 1850 if (paramName.isEmpty()) { 1851 // no name for this specific parameter 1852 paramName = createArgName(i, paramNames); 1853 } 1854 } 1855 buf.append(new VarSymbol(PARAMETER, paramName, t, this)); 1856 i++; 1857 } 1858 params = buf.toList(); 1859 } 1860 return params; 1861 } 1862 1863 // Create a name for the argument at position 'index' that is not in 1864 // the exclude list. In normal use, either no names will have been 1865 // provided, in which case the exclude list is empty, or all the names 1866 // will have been provided, in which case this method will not be called. 1867 private Name createArgName(int index, List<Name> exclude) { 1868 String prefix = "arg"; 1869 while (true) { 1870 Name argName = name.table.fromString(prefix + index); 1871 if (!exclude.contains(argName)) 1872 return argName; 1873 prefix += "$"; 1874 } 1875 } 1876 1877 public Symbol asMemberOf(Type site, Types types) { 1878 return new MethodSymbol(flags_field, name, types.memberType(site, this), owner); 1879 } 1880 1881 @DefinedBy(Api.LANGUAGE_MODEL) 1882 public ElementKind getKind() { 1883 if (name == name.table.names.init) 1884 return ElementKind.CONSTRUCTOR; 1885 else if (name == name.table.names.clinit) 1886 return ElementKind.STATIC_INIT; 1887 else if ((flags() & BLOCK) != 0) 1888 return isStatic() ? ElementKind.STATIC_INIT : ElementKind.INSTANCE_INIT; 1889 else 1890 return ElementKind.METHOD; 1891 } 1892 1893 public boolean isStaticOrInstanceInit() { 1894 return getKind() == ElementKind.STATIC_INIT || 1895 getKind() == ElementKind.INSTANCE_INIT; 1896 } 1897 1898 @DefinedBy(Api.LANGUAGE_MODEL) 1899 public Attribute getDefaultValue() { 1900 return defaultValue; 1901 } 1902 1903 @DefinedBy(Api.LANGUAGE_MODEL) 1904 public List<VarSymbol> getParameters() { 1905 return params(); 1906 } 1907 1908 @DefinedBy(Api.LANGUAGE_MODEL) 1909 public boolean isVarArgs() { 1910 return (flags() & VARARGS) != 0; 1911 } 1912 1913 @DefinedBy(Api.LANGUAGE_MODEL) 1914 public boolean isDefault() { 1915 return (flags() & DEFAULT) != 0; 1916 } 1917 1918 @DefinedBy(Api.LANGUAGE_MODEL) 1919 public <R, P> R accept(ElementVisitor<R, P> v, P p) { 1920 return v.visitExecutable(this, p); 1921 } 1922 1923 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) { 1924 return v.visitMethodSymbol(this, p); 1925 } 1926 1927 @DefinedBy(Api.LANGUAGE_MODEL) 1928 public Type getReceiverType() { 1929 return asType().getReceiverType(); 1930 } 1931 1932 @DefinedBy(Api.LANGUAGE_MODEL) 1933 public Type getReturnType() { 1934 return asType().getReturnType(); 1935 } 1936 1937 @DefinedBy(Api.LANGUAGE_MODEL) 1938 public List<Type> getThrownTypes() { 1939 return asType().getThrownTypes(); 1940 } 1941 } 1942 1943 /** A class for invokedynamic method calls. 1944 */ 1945 public static class DynamicMethodSymbol extends MethodSymbol { 1946 1947 public Object[] staticArgs; 1948 public Symbol bsm; 1949 public int bsmKind; 1950 1951 public DynamicMethodSymbol(Name name, Symbol owner, int bsmKind, MethodSymbol bsm, Type type, Object[] staticArgs) { 1952 super(0, name, type, owner); 1953 this.bsm = bsm; 1954 this.bsmKind = bsmKind; 1955 this.staticArgs = staticArgs; 1956 } 1957 1958 @Override 1959 public boolean isDynamic() { 1960 return true; 1961 } 1962 } 1963 1964 /** A class for predefined operators. 1965 */ 1966 public static class OperatorSymbol extends MethodSymbol { 1967 1968 public int opcode; 1969 private int accessCode = Integer.MIN_VALUE; 1970 1971 public OperatorSymbol(Name name, Type type, int opcode, Symbol owner) { 1972 super(PUBLIC | STATIC, name, type, owner); 1973 this.opcode = opcode; 1974 } 1975 1976 @Override 1977 public <R, P> R accept(Symbol.Visitor<R, P> v, P p) { 1978 return v.visitOperatorSymbol(this, p); 1979 } 1980 1981 public int getAccessCode(Tag tag) { 1982 if (accessCode != Integer.MIN_VALUE && !tag.isIncOrDecUnaryOp()) { 1983 return accessCode; 1984 } 1985 accessCode = AccessCode.from(tag, opcode); 1986 return accessCode; 1987 } 1988 1989 /** Access codes for dereferencing, assignment, 1990 * and pre/post increment/decrement. 1991 1992 * All access codes for accesses to the current class are even. 1993 * If a member of the superclass should be accessed instead (because 1994 * access was via a qualified super), add one to the corresponding code 1995 * for the current class, making the number odd. 1996 * This numbering scheme is used by the backend to decide whether 1997 * to issue an invokevirtual or invokespecial call. 1998 * 1999 * @see Gen#visitSelect(JCFieldAccess tree) 2000 */ 2001 public enum AccessCode { 2002 UNKNOWN(-1, Tag.NO_TAG), 2003 DEREF(0, Tag.NO_TAG), 2004 ASSIGN(2, Tag.ASSIGN), 2005 PREINC(4, Tag.PREINC), 2006 PREDEC(6, Tag.PREDEC), 2007 POSTINC(8, Tag.POSTINC), 2008 POSTDEC(10, Tag.POSTDEC), 2009 FIRSTASGOP(12, Tag.NO_TAG); 2010 2011 public final int code; 2012 public final Tag tag; 2013 public static final int numberOfAccessCodes = (lushrl - ishll + lxor + 2 - iadd) * 2 + FIRSTASGOP.code + 2; 2014 2015 AccessCode(int code, Tag tag) { 2016 this.code = code; 2017 this.tag = tag; 2018 } 2019 2020 static public AccessCode getFromCode(int code) { 2021 for (AccessCode aCodes : AccessCode.values()) { 2022 if (aCodes.code == code) { 2023 return aCodes; 2024 } 2025 } 2026 return UNKNOWN; 2027 } 2028 2029 static int from(Tag tag, int opcode) { 2030 /** Map bytecode of binary operation to access code of corresponding 2031 * assignment operation. This is always an even number. 2032 */ 2033 switch (tag) { 2034 case PREINC: 2035 return AccessCode.PREINC.code; 2036 case PREDEC: 2037 return AccessCode.PREDEC.code; 2038 case POSTINC: 2039 return AccessCode.POSTINC.code; 2040 case POSTDEC: 2041 return AccessCode.POSTDEC.code; 2042 } 2043 if (iadd <= opcode && opcode <= lxor) { 2044 return (opcode - iadd) * 2 + FIRSTASGOP.code; 2045 } else if (opcode == string_add) { 2046 return (lxor + 1 - iadd) * 2 + FIRSTASGOP.code; 2047 } else if (ishll <= opcode && opcode <= lushrl) { 2048 return (opcode - ishll + lxor + 2 - iadd) * 2 + FIRSTASGOP.code; 2049 } 2050 return -1; 2051 } 2052 } 2053 } 2054 2055 /** Symbol completer interface. 2056 */ 2057 public static interface Completer { 2058 2059 /** Dummy completer to be used when the symbol has been completed or 2060 * does not need completion. 2061 */ 2062 public final static Completer NULL_COMPLETER = new Completer() { 2063 public void complete(Symbol sym) { } 2064 public boolean isTerminal() { return true; } 2065 }; 2066 2067 void complete(Symbol sym) throws CompletionFailure; 2068 2069 /** Returns true if this completer is <em>terminal</em>. A terminal 2070 * completer is used as a place holder when the symbol is completed. 2071 * Calling complete on a terminal completer will not affect the symbol. 2072 * 2073 * The dummy NULL_COMPLETER and the GraphDependencies completer are 2074 * examples of terminal completers. 2075 * 2076 * @return true iff this completer is terminal 2077 */ 2078 default boolean isTerminal() { 2079 return false; 2080 } 2081 } 2082 2083 public static class CompletionFailure extends RuntimeException { 2084 private static final long serialVersionUID = 0; 2085 public Symbol sym; 2086 2087 /** A diagnostic object describing the failure 2088 */ 2089 public JCDiagnostic diag; 2090 2091 /** A localized string describing the failure. 2092 * @deprecated Use {@code getDetail()} or {@code getMessage()} 2093 */ 2094 @Deprecated 2095 public String errmsg; 2096 2097 public CompletionFailure(Symbol sym, String errmsg) { 2098 this.sym = sym; 2099 this.errmsg = errmsg; 2100// this.printStackTrace();//DEBUG 2101 } 2102 2103 public CompletionFailure(Symbol sym, JCDiagnostic diag) { 2104 this.sym = sym; 2105 this.diag = diag; 2106// this.printStackTrace();//DEBUG 2107 } 2108 2109 public JCDiagnostic getDiagnostic() { 2110 return diag; 2111 } 2112 2113 @Override 2114 public String getMessage() { 2115 if (diag != null) 2116 return diag.getMessage(null); 2117 else 2118 return errmsg; 2119 } 2120 2121 public Object getDetailValue() { 2122 return (diag != null ? diag : errmsg); 2123 } 2124 2125 @Override 2126 public CompletionFailure initCause(Throwable cause) { 2127 super.initCause(cause); 2128 return this; 2129 } 2130 2131 } 2132 2133 /** 2134 * A visitor for symbols. A visitor is used to implement operations 2135 * (or relations) on symbols. Most common operations on types are 2136 * binary relations and this interface is designed for binary 2137 * relations, that is, operations on the form 2138 * Symbol × P → R. 2139 * <!-- In plain text: Type x P -> R --> 2140 * 2141 * @param <R> the return type of the operation implemented by this 2142 * visitor; use Void if no return type is needed. 2143 * @param <P> the type of the second argument (the first being the 2144 * symbol itself) of the operation implemented by this visitor; use 2145 * Void if a second argument is not needed. 2146 */ 2147 public interface Visitor<R,P> { 2148 R visitClassSymbol(ClassSymbol s, P arg); 2149 R visitMethodSymbol(MethodSymbol s, P arg); 2150 R visitPackageSymbol(PackageSymbol s, P arg); 2151 R visitOperatorSymbol(OperatorSymbol s, P arg); 2152 R visitVarSymbol(VarSymbol s, P arg); 2153 R visitTypeSymbol(TypeSymbol s, P arg); 2154 R visitSymbol(Symbol s, P arg); 2155 } 2156} 2157