1 /*
  2  * Copyright (c) 1999, 2022, 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 
 26 package com.sun.tools.javac.code;
 27 
 28 import java.util.Collection;
 29 import java.util.Collections;
 30 import java.util.EnumSet;
 31 import java.util.HashMap;
 32 import java.util.LinkedHashMap;
 33 import java.util.Map;
 34 
 35 import javax.lang.model.element.ElementVisitor;
 36 
 37 import com.sun.tools.javac.code.Scope.WriteableScope;
 38 import com.sun.tools.javac.code.Source.Feature;
 39 import com.sun.tools.javac.code.Symbol.ClassSymbol;
 40 import com.sun.tools.javac.code.Symbol.Completer;
 41 import com.sun.tools.javac.code.Symbol.CompletionFailure;
 42 import com.sun.tools.javac.code.Symbol.MethodSymbol;
 43 import com.sun.tools.javac.code.Symbol.ModuleSymbol;
 44 import com.sun.tools.javac.code.Symbol.PackageSymbol;
 45 import com.sun.tools.javac.code.Symbol.RootPackageSymbol;
 46 import com.sun.tools.javac.code.Symbol.TypeSymbol;
 47 import com.sun.tools.javac.code.Symbol.VarSymbol;
 48 import com.sun.tools.javac.code.Type.BottomType;
 49 import com.sun.tools.javac.code.Type.ClassType;
 50 import com.sun.tools.javac.code.Type.ErrorType;
 51 import com.sun.tools.javac.code.Type.JCPrimitiveType;
 52 import com.sun.tools.javac.code.Type.JCVoidType;
 53 import com.sun.tools.javac.code.Type.MethodType;
 54 import com.sun.tools.javac.code.Type.UnknownType;
 55 import com.sun.tools.javac.code.Types.UniqueType;
 56 import com.sun.tools.javac.comp.Modules;
 57 import com.sun.tools.javac.jvm.Target;
 58 import com.sun.tools.javac.util.Assert;
 59 import com.sun.tools.javac.util.Context;
 60 import com.sun.tools.javac.util.Convert;
 61 import com.sun.tools.javac.util.DefinedBy;
 62 import com.sun.tools.javac.util.DefinedBy.Api;
 63 import com.sun.tools.javac.util.Iterators;
 64 import com.sun.tools.javac.util.JavacMessages;
 65 import com.sun.tools.javac.util.List;
 66 import com.sun.tools.javac.util.Name;
 67 import com.sun.tools.javac.util.Names;
 68 
 69 import static com.sun.tools.javac.code.Flags.*;
 70 import static com.sun.tools.javac.code.Kinds.Kind.*;
 71 import static com.sun.tools.javac.code.TypeTag.*;
 72 
 73 /** A class that defines all predefined constants and operators
 74  *  as well as special classes such as java.lang.Object, which need
 75  *  to be known to the compiler. All symbols are held in instance
 76  *  fields. This makes it possible to work in multiple concurrent
 77  *  projects, which might use different class files for library classes.
 78  *
 79  *  <p><b>This is NOT part of any supported API.
 80  *  If you write code that depends on this, you do so at your own risk.
 81  *  This code and its internal interfaces are subject to change or
 82  *  deletion without notice.</b>
 83  */
 84 public class Symtab {
 85     /** The context key for the symbol table. */
 86     protected static final Context.Key<Symtab> symtabKey = new Context.Key<>();
 87 
 88     /** Get the symbol table instance. */
 89     public static Symtab instance(Context context) {
 90         Symtab instance = context.get(symtabKey);
 91         if (instance == null)
 92             instance = new Symtab(context);
 93         return instance;
 94     }
 95 
 96     /** Builtin types.
 97      */
 98     public final JCPrimitiveType byteType = new JCPrimitiveType(BYTE, null);
 99     public final JCPrimitiveType charType = new JCPrimitiveType(CHAR, null);
100     public final JCPrimitiveType shortType = new JCPrimitiveType(SHORT, null);
101     public final JCPrimitiveType intType = new JCPrimitiveType(INT, null);
102     public final JCPrimitiveType longType = new JCPrimitiveType(LONG, null);
103     public final JCPrimitiveType floatType = new JCPrimitiveType(FLOAT, null);
104     public final JCPrimitiveType doubleType = new JCPrimitiveType(DOUBLE, null);
105     public final JCPrimitiveType booleanType = new JCPrimitiveType(BOOLEAN, null);
106     public final Type botType = new BottomType();
107     public final JCVoidType voidType = new JCVoidType();
108 
109     private final Names names;
110     private final JavacMessages messages;
111     private final Completer initialCompleter;
112     private final Completer moduleCompleter;
113 
114     /** A symbol for the unnamed module.
115      */
116     public final ModuleSymbol unnamedModule;
117 
118     /** The error module.
119      */
120     public final ModuleSymbol errModule;
121 
122     /** A symbol for no module, for use with -source 8 or less
123      */
124     public final ModuleSymbol noModule;
125 
126     /** A symbol for the root package.
127      */
128     public final PackageSymbol rootPackage;
129 
130     /** A symbol that stands for a missing symbol.
131      */
132     public final TypeSymbol noSymbol;
133 
134     /** The error symbol.
135      */
136     public final ClassSymbol errSymbol;
137 
138     /** The unknown symbol.
139      */
140     public final ClassSymbol unknownSymbol;
141 
142     /** A value for the errType, with a originalType of noType */
143     public final Type errType;
144 
145     /** A value for the unknown type. */
146     public final Type unknownType;
147 
148     /** The builtin type of all arrays. */
149     public final ClassSymbol arrayClass;
150     public final MethodSymbol arrayCloneMethod;
151 
152     /** VGJ: The (singleton) type of all bound types. */
153     public final ClassSymbol boundClass;
154 
155     /** The builtin type of all methods. */
156     public final ClassSymbol methodClass;
157 
158     /** A symbol for the java.base module.
159      */
160     public final ModuleSymbol java_base;
161 
162     /** Predefined types.
163      */
164     public final Type objectType;
165     public final Type objectMethodsType;
166     public final Type exactConversionsSupportType;
167     public final Type objectsType;
168     public final Type classType;
169     public final Type classLoaderType;
170     public final Type stringType;
171     public final Type stringBufferType;
172     public final Type stringBuilderType;
173     public final Type cloneableType;
174     public final Type serializableType;
175     public final Type serializedLambdaType;
176     public final Type varHandleType;
177     public final Type methodHandleType;
178     public final Type methodHandlesType;
179     public final Type methodHandleLookupType;
180     public final Type methodTypeType;
181     public final Type nativeHeaderType;
182     public final Type throwableType;
183     public final Type errorType;
184     public final Type interruptedExceptionType;
185     public final Type illegalArgumentExceptionType;
186     public final Type exceptionType;
187     public final Type runtimeExceptionType;
188     public final Type classNotFoundExceptionType;
189     public final Type noClassDefFoundErrorType;
190     public final Type noSuchFieldErrorType;
191     public final Type assertionErrorType;
192     public final Type incompatibleClassChangeErrorType;
193     public final Type cloneNotSupportedExceptionType;
194     public final Type matchExceptionType;
195     public final Type annotationType;
196     public final TypeSymbol enumSym;
197     public final Type listType;
198     public final Type collectionsType;
199     public final Type comparableType;
200     public final Type comparatorType;
201     public final Type arraysType;
202     public final Type iterableType;
203     public final Type iteratorType;
204     public final Type annotationTargetType;
205     public final Type overrideType;
206     public final Type retentionType;
207     public final Type deprecatedType;
208     public final Type suppressWarningsType;
209     public final Type supplierType;
210     public final Type inheritedType;
211     public final Type profileType;
212     public final Type proprietaryType;
213     public final Type systemType;
214     public final Type autoCloseableType;
215     public final Type trustMeType;
216     public final Type lambdaMetafactory;
217     public final Type stringConcatFactory;
218     public final Type repeatableType;
219     public final Type documentedType;
220     public final Type elementTypeType;
221     public final Type functionalInterfaceType;
222     public final Type previewFeatureType;
223     public final Type previewFeatureInternalType;
224     public final Type restrictedType;
225     public final Type typeDescriptorType;
226     public final Type recordType;
227     public final Type switchBootstrapsType;
228     public final Type constantBootstrapsType;
229     public final Type valueBasedType;
230     public final Type valueBasedInternalType;
231     public final Type classDescType;
232     public final Type enumDescType;
233 
234     // For serialization lint checking
235     public final Type objectStreamFieldType;
236     public final Type objectInputStreamType;
237     public final Type objectOutputStreamType;
238     public final Type ioExceptionType;
239     public final Type objectStreamExceptionType;
240     // For externalization lint checking
241     public final Type externalizableType;
242     public final Type objectInputType;
243     public final Type objectOutputType;
244 
245     // For string templates
246     public final Type stringTemplateType;
247     public final Type templateRuntimeType;
248     public final Type processorType;
249     public final Type linkageType;
250 
251     /** The symbol representing the length field of an array.
252      */
253     public final VarSymbol lengthVar;
254 
255     /** The symbol representing the final finalize method on enums */
256     public final MethodSymbol enumFinalFinalize;
257 
258     /** The symbol representing the close method on TWR AutoCloseable type */
259     public final MethodSymbol autoCloseableClose;
260 
261     /** The predefined type that belongs to a tag.
262      */
263     public final Type[] typeOfTag = new Type[TypeTag.getTypeTagCount()];
264 
265     /** The name of the class that belongs to a basic type tag.
266      */
267     public final Name[] boxedName = new Name[TypeTag.getTypeTagCount()];
268 
269     /** A hashtable containing the encountered top-level and member classes,
270      *  indexed by flat names. The table does not contain local classes.
271      *  It should be updated from the outside to reflect classes defined
272      *  by compiled source files.
273      */
274     private final Map<Name, Map<ModuleSymbol,ClassSymbol>> classes = new HashMap<>();
275 
276     /** A hashtable containing the encountered packages.
277      *  the table should be updated from outside to reflect packages defined
278      *  by compiled source files.
279      */
280     private final Map<Name, Map<ModuleSymbol,PackageSymbol>> packages = new HashMap<>();
281 
282     /** A hashtable giving the encountered modules.
283      */
284     private final Map<Name, ModuleSymbol> modules = new LinkedHashMap<>();
285 
286     private final Map<Types.UniqueType, VarSymbol> classFields = new HashMap<>();
287 
288     public VarSymbol getClassField(Type type, Types types) {
289         return classFields.computeIfAbsent(
290             new UniqueType(type, types), k -> {
291                 Type arg = null;
292                 if (type.getTag() == ARRAY || type.getTag() == CLASS)
293                     arg = types.erasure(type);
294                 else if (type.isPrimitiveOrVoid())
295                     arg = types.boxedClass(type).type;
296                 else
297                     throw new AssertionError(type);
298 
299                 Type t = new ClassType(
300                     classType.getEnclosingType(), List.of(arg), classType.tsym);
301                 return new VarSymbol(
302                     STATIC | PUBLIC | FINAL, names._class, t, type.tsym);
303             });
304     }
305 
306     public void initType(Type type, ClassSymbol c) {
307         type.tsym = c;
308         typeOfTag[type.getTag().ordinal()] = type;
309     }
310 
311     public void initType(Type type, String name) {
312         initType(
313             type,
314             new ClassSymbol(
315                 PUBLIC, names.fromString(name), type, rootPackage));
316     }
317 
318     public void initType(Type type, String name, String bname) {
319         initType(type, name);
320         boxedName[type.getTag().ordinal()] = names.fromString("java.lang." + bname);
321     }
322 
323     /** The class symbol that owns all predefined symbols.
324      */
325     public final ClassSymbol predefClass;
326 
327     /** Enter a class into symbol table.
328      *  @param s The name of the class.
329      */
330     private Type enterClass(String s) {
331         return enterClass(java_base, names.fromString(s)).type;
332     }
333 
334     public void synthesizeEmptyInterfaceIfMissing(final Type type) {
335         final Completer completer = type.tsym.completer;
336         type.tsym.completer = new Completer() {
337             @Override
338             public void complete(Symbol sym) throws CompletionFailure {
339                 try {
340                     completer.complete(sym);
341                 } catch (CompletionFailure e) {
342                     sym.flags_field |= (PUBLIC | INTERFACE);
343                     ((ClassType) sym.type).supertype_field = objectType;
344                 }
345             }
346 
347             @Override
348             public boolean isTerminal() {
349                 return completer.isTerminal();
350             }
351         };
352     }
353 
354     public void synthesizeBoxTypeIfMissing(final Type type) {
355         ClassSymbol sym = enterClass(java_base, boxedName[type.getTag().ordinal()]);
356         final Completer completer = sym.completer;
357         sym.completer = new Completer() {
358             @Override
359             public void complete(Symbol sym) throws CompletionFailure {
360                 try {
361                     completer.complete(sym);
362                 } catch (CompletionFailure e) {
363                     sym.flags_field |= PUBLIC;
364                     ((ClassType) sym.type).supertype_field = objectType;
365                     MethodSymbol boxMethod =
366                         new MethodSymbol(PUBLIC | STATIC, names.valueOf,
367                                          new MethodType(List.of(type), sym.type,
368                                 List.nil(), methodClass),
369                             sym);
370                     sym.members().enter(boxMethod);
371                     MethodSymbol unboxMethod =
372                         new MethodSymbol(PUBLIC,
373                             type.tsym.name.append(names.Value), // x.intValue()
374                             new MethodType(List.nil(), type,
375                                 List.nil(), methodClass),
376                             sym);
377                     sym.members().enter(unboxMethod);
378                 }
379             }
380 
381             @Override
382             public boolean isTerminal() {
383                 return completer.isTerminal();
384             }
385         };
386     }
387 
388     // Enter a synthetic class that is used to mark classes in ct.sym.
389     // This class does not have a class file.
390     private Type enterSyntheticAnnotation(String name) {
391         // for now, leave the module null, to prevent problems from synthesizing the
392         // existence of a class in any specific module, including noModule
393         ClassType type = (ClassType)enterClass(java_base, names.fromString(name)).type;
394         ClassSymbol sym = (ClassSymbol)type.tsym;
395         sym.completer = Completer.NULL_COMPLETER;
396         sym.flags_field = PUBLIC|ACYCLIC|ANNOTATION|INTERFACE;
397         sym.erasure_field = type;
398         sym.members_field = WriteableScope.create(sym);
399         type.typarams_field = List.nil();
400         type.allparams_field = List.nil();
401         type.supertype_field = annotationType;
402         type.interfaces_field = List.nil();
403         return type;
404     }
405 
406     /** Constructor; enters all predefined identifiers and operators
407      *  into symbol table.
408      */
409     @SuppressWarnings("this-escape")
410     protected Symtab(Context context) throws CompletionFailure {
411         context.put(symtabKey, this);
412 
413         names = Names.instance(context);
414 
415         // Create the unknown type
416         unknownType = new UnknownType();
417 
418         messages = JavacMessages.instance(context);
419 
420         MissingInfoHandler missingInfoHandler = MissingInfoHandler.instance(context);
421 
422         Target target = Target.instance(context);
423         rootPackage = new RootPackageSymbol(names.empty, null,
424                                             missingInfoHandler,
425                                             target.runtimeUseNestAccess());
426 
427         // create the basic builtin symbols
428         unnamedModule = new ModuleSymbol(names.empty, null) {
429                 {
430                     directives = List.nil();
431                     exports = List.nil();
432                     provides = List.nil();
433                     uses = List.nil();
434                     ModuleSymbol java_base = enterModule(names.java_base);
435                     com.sun.tools.javac.code.Directive.RequiresDirective d =
436                             new com.sun.tools.javac.code.Directive.RequiresDirective(java_base,
437                                     EnumSet.of(com.sun.tools.javac.code.Directive.RequiresFlag.MANDATED));
438                     requires = List.of(d);
439                 }
440                 @Override
441                 public String toString() {
442                     return messages.getLocalizedString("compiler.misc.unnamed.module");
443                 }
444             };
445         addRootPackageFor(unnamedModule);
446         unnamedModule.enclosedPackages = unnamedModule.enclosedPackages.prepend(unnamedModule.unnamedPackage);
447 
448         errModule = new ModuleSymbol(names.empty, null) {
449                 {
450                     directives = List.nil();
451                     exports = List.nil();
452                     provides = List.nil();
453                     uses = List.nil();
454                     ModuleSymbol java_base = enterModule(names.java_base);
455                     com.sun.tools.javac.code.Directive.RequiresDirective d =
456                             new com.sun.tools.javac.code.Directive.RequiresDirective(java_base,
457                                     EnumSet.of(com.sun.tools.javac.code.Directive.RequiresFlag.MANDATED));
458                     requires = List.of(d);
459                 }
460             };
461         addRootPackageFor(errModule);
462 
463         noModule = new ModuleSymbol(names.empty, null) {
464             @Override public boolean isNoModule() {
465                 return true;
466             }
467         };
468         addRootPackageFor(noModule);
469 
470         noSymbol = new TypeSymbol(NIL, 0, names.empty, Type.noType, rootPackage) {
471             @Override @DefinedBy(Api.LANGUAGE_MODEL)
472             public <R, P> R accept(ElementVisitor<R, P> v, P p) {
473                 return v.visitUnknown(this, p);
474             }
475         };
476 
477         // create the error symbols
478         errSymbol = new ClassSymbol(PUBLIC|STATIC|ACYCLIC, names.any, null, rootPackage);
479         errType = new ErrorType(errSymbol, Type.noType);
480 
481         unknownSymbol = new ClassSymbol(PUBLIC|STATIC|ACYCLIC, names.fromString("<any?>"), null, rootPackage);
482         unknownSymbol.members_field = new Scope.ErrorScope(unknownSymbol);
483         unknownSymbol.type = unknownType;
484 
485         // initialize builtin types
486         initType(byteType, "byte", "Byte");
487         initType(shortType, "short", "Short");
488         initType(charType, "char", "Character");
489         initType(intType, "int", "Integer");
490         initType(longType, "long", "Long");
491         initType(floatType, "float", "Float");
492         initType(doubleType, "double", "Double");
493         initType(booleanType, "boolean", "Boolean");
494         initType(voidType, "void", "Void");
495         initType(botType, "<nulltype>");
496         initType(errType, errSymbol);
497         initType(unknownType, unknownSymbol);
498 
499         // the builtin class of all arrays
500         arrayClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Array, noSymbol);
501 
502         // VGJ
503         boundClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Bound, noSymbol);
504         boundClass.members_field = new Scope.ErrorScope(boundClass);
505 
506         // the builtin class of all methods
507         methodClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Method, noSymbol);
508         methodClass.members_field = new Scope.ErrorScope(boundClass);
509 
510         // Create class to hold all predefined constants and operations.
511         predefClass = new ClassSymbol(PUBLIC|ACYCLIC, names.empty, rootPackage);
512         WriteableScope scope = WriteableScope.create(predefClass);
513         predefClass.members_field = scope;
514 
515         // Get the initial completer for Symbols from the ClassFinder
516         initialCompleter = ClassFinder.instance(context).getCompleter();
517         rootPackage.members_field = WriteableScope.create(rootPackage);
518 
519         // Enter symbols for basic types.
520         scope.enter(byteType.tsym);
521         scope.enter(shortType.tsym);
522         scope.enter(charType.tsym);
523         scope.enter(intType.tsym);
524         scope.enter(longType.tsym);
525         scope.enter(floatType.tsym);
526         scope.enter(doubleType.tsym);
527         scope.enter(booleanType.tsym);
528         scope.enter(errType.tsym);
529 
530         // Enter symbol for the errSymbol
531         scope.enter(errSymbol);
532 
533         Source source = Source.instance(context);
534         if (Feature.MODULES.allowedInSource(source)) {
535             java_base = enterModule(names.java_base);
536             //avoid completing java.base during the Symtab initialization
537             java_base.completer = Completer.NULL_COMPLETER;
538             java_base.visiblePackages = Collections.emptyMap();
539         } else {
540             java_base = noModule;
541         }
542 
543         // Get the initial completer for ModuleSymbols from Modules
544         moduleCompleter = Modules.instance(context).getCompleter();
545 
546         // Enter predefined classes. All are assumed to be in the java.base module.
547         objectType = enterClass("java.lang.Object");
548         objectMethodsType = enterClass("java.lang.runtime.ObjectMethods");
549         exactConversionsSupportType = enterClass("java.lang.runtime.ExactConversionsSupport");
550         objectsType = enterClass("java.util.Objects");
551         classType = enterClass("java.lang.Class");
552         stringType = enterClass("java.lang.String");
553         stringBufferType = enterClass("java.lang.StringBuffer");
554         stringBuilderType = enterClass("java.lang.StringBuilder");
555         cloneableType = enterClass("java.lang.Cloneable");
556         throwableType = enterClass("java.lang.Throwable");
557         serializableType = enterClass("java.io.Serializable");
558         serializedLambdaType = enterClass("java.lang.invoke.SerializedLambda");
559         varHandleType = enterClass("java.lang.invoke.VarHandle");
560         methodHandleType = enterClass("java.lang.invoke.MethodHandle");
561         methodHandlesType = enterClass("java.lang.invoke.MethodHandles");
562         methodHandleLookupType = enterClass("java.lang.invoke.MethodHandles$Lookup");
563         methodTypeType = enterClass("java.lang.invoke.MethodType");
564         errorType = enterClass("java.lang.Error");
565         illegalArgumentExceptionType = enterClass("java.lang.IllegalArgumentException");
566         interruptedExceptionType = enterClass("java.lang.InterruptedException");
567         exceptionType = enterClass("java.lang.Exception");
568         runtimeExceptionType = enterClass("java.lang.RuntimeException");
569         classNotFoundExceptionType = enterClass("java.lang.ClassNotFoundException");
570         noClassDefFoundErrorType = enterClass("java.lang.NoClassDefFoundError");
571         noSuchFieldErrorType = enterClass("java.lang.NoSuchFieldError");
572         assertionErrorType = enterClass("java.lang.AssertionError");
573         incompatibleClassChangeErrorType = enterClass("java.lang.IncompatibleClassChangeError");
574         cloneNotSupportedExceptionType = enterClass("java.lang.CloneNotSupportedException");
575         matchExceptionType = enterClass("java.lang.MatchException");
576         annotationType = enterClass("java.lang.annotation.Annotation");
577         classLoaderType = enterClass("java.lang.ClassLoader");
578         enumSym = enterClass(java_base, names.java_lang_Enum);
579         enumFinalFinalize =
580             new MethodSymbol(PROTECTED|FINAL|HYPOTHETICAL,
581                              names.finalize,
582                              new MethodType(List.nil(), voidType,
583                                             List.nil(), methodClass),
584                              enumSym);
585         listType = enterClass("java.util.List");
586         collectionsType = enterClass("java.util.Collections");
587         comparableType = enterClass("java.lang.Comparable");
588         comparatorType = enterClass("java.util.Comparator");
589         arraysType = enterClass("java.util.Arrays");
590         iterableType = enterClass("java.lang.Iterable");
591         iteratorType = enterClass("java.util.Iterator");
592         annotationTargetType = enterClass("java.lang.annotation.Target");
593         overrideType = enterClass("java.lang.Override");
594         retentionType = enterClass("java.lang.annotation.Retention");
595         deprecatedType = enterClass("java.lang.Deprecated");
596         suppressWarningsType = enterClass("java.lang.SuppressWarnings");
597         supplierType = enterClass("java.util.function.Supplier");
598         inheritedType = enterClass("java.lang.annotation.Inherited");
599         repeatableType = enterClass("java.lang.annotation.Repeatable");
600         documentedType = enterClass("java.lang.annotation.Documented");
601         elementTypeType = enterClass("java.lang.annotation.ElementType");
602         systemType = enterClass("java.lang.System");
603         autoCloseableType = enterClass("java.lang.AutoCloseable");
604         autoCloseableClose = new MethodSymbol(PUBLIC,
605                              names.close,
606                              new MethodType(List.nil(), voidType,
607                                             List.of(exceptionType), methodClass),
608                              autoCloseableType.tsym);
609         trustMeType = enterClass("java.lang.SafeVarargs");
610         nativeHeaderType = enterClass("java.lang.annotation.Native");
611         lambdaMetafactory = enterClass("java.lang.invoke.LambdaMetafactory");
612         stringConcatFactory = enterClass("java.lang.invoke.StringConcatFactory");
613         functionalInterfaceType = enterClass("java.lang.FunctionalInterface");
614         previewFeatureType = enterClass("jdk.internal.javac.PreviewFeature");
615         previewFeatureInternalType = enterSyntheticAnnotation("jdk.internal.PreviewFeature+Annotation");
616         restrictedType = enterClass("jdk.internal.javac.Restricted");
617         typeDescriptorType = enterClass("java.lang.invoke.TypeDescriptor");
618         recordType = enterClass("java.lang.Record");
619         switchBootstrapsType = enterClass("java.lang.runtime.SwitchBootstraps");
620         constantBootstrapsType = enterClass("java.lang.invoke.ConstantBootstraps");
621         valueBasedType = enterClass("jdk.internal.ValueBased");
622         valueBasedInternalType = enterSyntheticAnnotation("jdk.internal.ValueBased+Annotation");
623         classDescType = enterClass("java.lang.constant.ClassDesc");
624         enumDescType = enterClass("java.lang.Enum$EnumDesc");
625         // For serialization lint checking
626         objectStreamFieldType = enterClass("java.io.ObjectStreamField");
627         objectInputStreamType = enterClass("java.io.ObjectInputStream");
628         objectOutputStreamType = enterClass("java.io.ObjectOutputStream");
629         ioExceptionType = enterClass("java.io.IOException");
630         objectStreamExceptionType = enterClass("java.io.ObjectStreamException");
631         externalizableType = enterClass("java.io.Externalizable");
632         objectInputType  = enterClass("java.io.ObjectInput");
633         objectOutputType = enterClass("java.io.ObjectOutput");
634         synthesizeEmptyInterfaceIfMissing(autoCloseableType);
635         synthesizeEmptyInterfaceIfMissing(cloneableType);
636         synthesizeEmptyInterfaceIfMissing(serializableType);
637         synthesizeEmptyInterfaceIfMissing(lambdaMetafactory);
638         synthesizeEmptyInterfaceIfMissing(serializedLambdaType);
639         synthesizeEmptyInterfaceIfMissing(stringConcatFactory);
640         synthesizeBoxTypeIfMissing(doubleType);
641         synthesizeBoxTypeIfMissing(floatType);
642         synthesizeBoxTypeIfMissing(voidType);
643 
644         // For string templates
645         stringTemplateType = enterClass("java.lang.StringTemplate");
646         templateRuntimeType = enterClass("java.lang.runtime.TemplateRuntime");
647         processorType = enterClass("java.lang.StringTemplate$Processor");
648         linkageType = enterClass("java.lang.StringTemplate$Processor$Linkage");
649 
650         // Enter a synthetic class that is used to mark internal
651         // proprietary classes in ct.sym.  This class does not have a
652         // class file.
653         proprietaryType = enterSyntheticAnnotation("sun.Proprietary+Annotation");
654 
655         // Enter a synthetic class that is used to provide profile info for
656         // classes in ct.sym.  This class does not have a class file.
657         profileType = enterSyntheticAnnotation("jdk.Profile+Annotation");
658         MethodSymbol m = new MethodSymbol(PUBLIC | ABSTRACT, names.value, intType, profileType.tsym);
659         profileType.tsym.members().enter(m);
660 
661         // Enter a class for arrays.
662         // The class implements java.lang.Cloneable and java.io.Serializable.
663         // It has a final length field and a clone method.
664         ClassType arrayClassType = (ClassType)arrayClass.type;
665         arrayClassType.supertype_field = objectType;
666         arrayClassType.interfaces_field = List.of(cloneableType, serializableType);
667         arrayClass.members_field = WriteableScope.create(arrayClass);
668         lengthVar = new VarSymbol(
669             PUBLIC | FINAL,
670             names.length,
671             intType,
672             arrayClass);
673         arrayClass.members().enter(lengthVar);
674         arrayCloneMethod = new MethodSymbol(
675             PUBLIC,
676             names.clone,
677             new MethodType(List.nil(), objectType,
678                            List.nil(), methodClass),
679             arrayClass);
680         arrayClass.members().enter(arrayCloneMethod);
681 
682         if (java_base != noModule)
683             java_base.completer = moduleCompleter::complete; //bootstrap issues
684 
685     }
686 
687     /** Define a new class given its name and owner.
688      */
689     public ClassSymbol defineClass(Name name, Symbol owner) {
690         ClassSymbol c = new ClassSymbol(0, name, owner);
691         c.completer = initialCompleter;
692         return c;
693     }
694 
695     /** Create a new toplevel or member class symbol with given name
696      *  and owner and enter in `classes' unless already there.
697      */
698     public ClassSymbol enterClass(ModuleSymbol msym, Name name, TypeSymbol owner) {
699         Assert.checkNonNull(msym);
700         Name flatname = TypeSymbol.formFlatName(name, owner);
701         ClassSymbol c = getClass(msym, flatname);
702         if (c == null) {
703             c = defineClass(name, owner);
704             doEnterClass(msym, c);
705         } else if ((c.name != name || c.owner != owner) && owner.kind == TYP &&
706                    c.owner.kind == PCK && ((c.flags_field & FROM_SOURCE) == 0)) {
707             // reassign fields of classes that might have been loaded with
708             // their flat names.
709             c.owner.members().remove(c);
710             c.name = name;
711             c.owner = owner;
712             c.fullname = ClassSymbol.formFullName(name, owner);
713         }
714         return c;
715     }
716 
717     public ClassSymbol getClass(ModuleSymbol msym, Name flatName) {
718         Assert.checkNonNull(msym, flatName::toString);
719         return classes.getOrDefault(flatName, Collections.emptyMap()).get(msym);
720     }
721 
722     public PackageSymbol lookupPackage(ModuleSymbol msym, Name flatName) {
723         return lookupPackage(msym, flatName, false);
724     }
725 
726     private PackageSymbol lookupPackage(ModuleSymbol msym, Name flatName, boolean onlyExisting) {
727         Assert.checkNonNull(msym);
728 
729         if (flatName.isEmpty()) {
730             //unnamed packages only from the current module - visiblePackages contains *root* package, not unnamed package!
731             return msym.unnamedPackage;
732         }
733 
734         if (msym == noModule) {
735             return enterPackage(msym, flatName);
736         }
737 
738         msym.complete();
739 
740         PackageSymbol pack;
741 
742         pack = msym.visiblePackages.get(flatName);
743 
744         if (pack != null)
745             return pack;
746 
747         pack = getPackage(msym, flatName);
748 
749         if ((pack != null && pack.exists()) || onlyExisting)
750             return pack;
751 
752         boolean dependsOnUnnamed = msym.requires != null &&
753                                    msym.requires.stream()
754                                                 .map(rd -> rd.module)
755                                                 .anyMatch(mod -> mod == unnamedModule);
756 
757         if (dependsOnUnnamed) {
758             //msyms depends on the unnamed module, for which we generally don't know
759             //the list of packages it "exports" ahead of time. So try to lookup the package in the
760             //current module, and in the unnamed module and see if it exists in one of them
761             PackageSymbol unnamedPack = getPackage(unnamedModule, flatName);
762 
763             if (unnamedPack != null && unnamedPack.exists()) {
764                 msym.visiblePackages.put(unnamedPack.fullname, unnamedPack);
765                 return unnamedPack;
766             }
767 
768             pack = enterPackage(msym, flatName);
769             pack.complete();
770             if (pack.exists())
771                 return pack;
772 
773             unnamedPack = enterPackage(unnamedModule, flatName);
774             unnamedPack.complete();
775             if (unnamedPack.exists()) {
776                 msym.visiblePackages.put(unnamedPack.fullname, unnamedPack);
777                 return unnamedPack;
778             }
779 
780             return pack;
781         }
782 
783         return enterPackage(msym, flatName);
784     }
785 
786     private static final Map<ModuleSymbol, ClassSymbol> EMPTY = new HashMap<>();
787 
788     public void removeClass(ModuleSymbol msym, Name flatName) {
789         classes.getOrDefault(flatName, EMPTY).remove(msym);
790     }
791 
792     public Iterable<ClassSymbol> getAllClasses() {
793         return () -> Iterators.createCompoundIterator(classes.values(), v -> v.values().iterator());
794     }
795 
796     private void doEnterClass(ModuleSymbol msym, ClassSymbol cs) {
797         classes.computeIfAbsent(cs.flatname, n -> new HashMap<>()).put(msym, cs);
798     }
799 
800     /** Create a new member or toplevel class symbol with given flat name
801      *  and enter in `classes' unless already there.
802      */
803     public ClassSymbol enterClass(ModuleSymbol msym, Name flatname) {
804         Assert.checkNonNull(msym);
805         PackageSymbol ps = lookupPackage(msym, Convert.packagePart(flatname));
806         Assert.checkNonNull(ps);
807         Assert.checkNonNull(ps.modle);
808         ClassSymbol c = getClass(ps.modle, flatname);
809         if (c == null) {
810             c = defineClass(Convert.shortName(flatname), ps);
811             doEnterClass(ps.modle, c);
812             return c;
813         } else
814             return c;
815     }
816 
817     /** Check to see if a package exists, given its fully qualified name.
818      */
819     public boolean packageExists(ModuleSymbol msym, Name fullname) {
820         Assert.checkNonNull(msym);
821         PackageSymbol pack = lookupPackage(msym, fullname, true);
822         return pack != null && pack.exists();
823     }
824 
825     /** Make a package, given its fully qualified name.
826      */
827     public PackageSymbol enterPackage(ModuleSymbol currModule, Name fullname) {
828         Assert.checkNonNull(currModule);
829         PackageSymbol p = getPackage(currModule, fullname);
830         if (p == null) {
831             Assert.check(!fullname.isEmpty(), () -> "rootPackage missing!; currModule: " + currModule);
832             p = new PackageSymbol(
833                     Convert.shortName(fullname),
834                     enterPackage(currModule, Convert.packagePart(fullname)));
835             p.completer = initialCompleter;
836             p.modle = currModule;
837             doEnterPackage(currModule, p);
838         }
839         return p;
840     }
841 
842     private void doEnterPackage(ModuleSymbol msym, PackageSymbol pack) {
843         packages.computeIfAbsent(pack.fullname, n -> new HashMap<>()).put(msym, pack);
844         msym.enclosedPackages = msym.enclosedPackages.prepend(pack);
845     }
846 
847     private void addRootPackageFor(ModuleSymbol module) {
848         doEnterPackage(module, rootPackage);
849         PackageSymbol unnamedPackage = new PackageSymbol(names.empty, rootPackage) {
850                 @Override
851                 public String toString() {
852                     return messages.getLocalizedString("compiler.misc.unnamed.package");
853                 }
854             };
855         unnamedPackage.modle = module;
856         //we cannot use a method reference below, as initialCompleter might be null now
857         unnamedPackage.completer = s -> initialCompleter.complete(s);
858         unnamedPackage.flags_field |= EXISTS;
859         module.unnamedPackage = unnamedPackage;
860     }
861 
862     public PackageSymbol getPackage(ModuleSymbol module, Name fullname) {
863         return packages.getOrDefault(fullname, Collections.emptyMap()).get(module);
864     }
865 
866     public ModuleSymbol enterModule(Name name) {
867         ModuleSymbol msym = modules.get(name);
868         if (msym == null) {
869             msym = ModuleSymbol.create(name, names.module_info);
870             addRootPackageFor(msym);
871             msym.completer = s -> moduleCompleter.complete(s); //bootstrap issues
872             modules.put(name, msym);
873         }
874         return msym;
875     }
876 
877     public ModuleSymbol getModule(Name name) {
878         return modules.get(name);
879     }
880 
881     //temporary:
882     public ModuleSymbol inferModule(Name packageName) {
883         if (packageName.isEmpty())
884             return java_base == noModule ? noModule : unnamedModule;//!
885 
886         ModuleSymbol msym = null;
887         Map<ModuleSymbol,PackageSymbol> map = packages.get(packageName);
888         if (map == null)
889             return null;
890         for (Map.Entry<ModuleSymbol,PackageSymbol> e: map.entrySet()) {
891             if (!e.getValue().members().isEmpty()) {
892                 if (msym == null) {
893                     msym = e.getKey();
894                 } else {
895                     return null;
896                 }
897             }
898         }
899         return msym;
900     }
901 
902     public List<ModuleSymbol> listPackageModules(Name packageName) {
903         if (packageName.isEmpty())
904             return List.nil();
905 
906         List<ModuleSymbol> result = List.nil();
907         Map<ModuleSymbol,PackageSymbol> map = packages.get(packageName);
908         if (map != null) {
909             for (Map.Entry<ModuleSymbol, PackageSymbol> e: map.entrySet()) {
910                 if (!e.getValue().members().isEmpty()) {
911                     result = result.prepend(e.getKey());
912                 }
913             }
914         }
915         return result;
916     }
917 
918     public Collection<ModuleSymbol> getAllModules() {
919         return modules.values();
920     }
921 
922     public Iterable<ClassSymbol> getClassesForName(Name candidate) {
923         return classes.getOrDefault(candidate, Collections.emptyMap()).values();
924     }
925 
926     public Iterable<PackageSymbol> getPackagesForName(Name candidate) {
927         return packages.getOrDefault(candidate, Collections.emptyMap()).values();
928     }
929 }