1 /*
  2  * Copyright (c) 1999, 2021, 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 objectsType;
167     public final Type classType;
168     public final Type classLoaderType;
169     public final Type stringType;
170     public final Type stringBufferType;
171     public final Type stringBuilderType;
172     public final Type cloneableType;
173     public final Type serializableType;
174     public final Type serializedLambdaType;
175     public final Type varHandleType;
176     public final Type methodHandleType;
177     public final Type methodHandleLookupType;
178     public final Type methodTypeType;
179     public final Type nativeHeaderType;
180     public final Type throwableType;
181     public final Type errorType;
182     public final Type interruptedExceptionType;
183     public final Type illegalArgumentExceptionType;
184     public final Type exceptionType;
185     public final Type runtimeExceptionType;
186     public final Type classNotFoundExceptionType;
187     public final Type noClassDefFoundErrorType;
188     public final Type noSuchFieldErrorType;
189     public final Type assertionErrorType;
190     public final Type incompatibleClassChangeErrorType;
191     public final Type cloneNotSupportedExceptionType;
192     public final Type annotationType;
193     public final TypeSymbol enumSym;
194     public final Type listType;
195     public final Type collectionsType;
196     public final Type comparableType;
197     public final Type comparatorType;
198     public final Type arraysType;
199     public final Type iterableType;
200     public final Type iteratorType;
201     public final Type annotationTargetType;
202     public final Type overrideType;
203     public final Type retentionType;
204     public final Type deprecatedType;
205     public final Type suppressWarningsType;
206     public final Type supplierType;
207     public final Type inheritedType;
208     public final Type profileType;
209     public final Type proprietaryType;
210     public final Type systemType;
211     public final Type autoCloseableType;
212     public final Type trustMeType;
213     public final Type lambdaMetafactory;
214     public final Type stringConcatFactory;
215     public final Type repeatableType;
216     public final Type documentedType;
217     public final Type elementTypeType;
218     public final Type functionalInterfaceType;
219     public final Type previewFeatureType;
220     public final Type previewFeatureInternalType;
221     public final Type typeDescriptorType;
222     public final Type recordType;
223     public final Type switchBootstrapsType;
224     public final Type valueBasedType;
225     public final Type valueBasedInternalType;
226 
227     // For serialization lint checking
228     public final Type objectStreamFieldType;
229     public final Type objectInputStreamType;
230     public final Type objectOutputStreamType;
231     public final Type ioExceptionType;
232     public final Type objectStreamExceptionType;
233     public final Type externalizableType;
234 
235     /** The symbol representing the length field of an array.
236      */
237     public final VarSymbol lengthVar;
238 
239     /** The symbol representing the final finalize method on enums */
240     public final MethodSymbol enumFinalFinalize;
241 
242     /** The symbol representing the close method on TWR AutoCloseable type */
243     public final MethodSymbol autoCloseableClose;
244 
245     /** The predefined type that belongs to a tag.
246      */
247     public final Type[] typeOfTag = new Type[TypeTag.getTypeTagCount()];
248 
249     /** The name of the class that belongs to a basic type tag.
250      */
251     public final Name[] boxedName = new Name[TypeTag.getTypeTagCount()];
252 
253     /** A hashtable containing the encountered top-level and member classes,
254      *  indexed by flat names. The table does not contain local classes.
255      *  It should be updated from the outside to reflect classes defined
256      *  by compiled source files.
257      */
258     private final Map<Name, Map<ModuleSymbol,ClassSymbol>> classes = new HashMap<>();
259 
260     /** A hashtable containing the encountered packages.
261      *  the table should be updated from outside to reflect packages defined
262      *  by compiled source files.
263      */
264     private final Map<Name, Map<ModuleSymbol,PackageSymbol>> packages = new HashMap<>();
265 
266     /** A hashtable giving the encountered modules.
267      */
268     private final Map<Name, ModuleSymbol> modules = new LinkedHashMap<>();
269 
270     private final Map<Types.UniqueType, VarSymbol> classFields = new HashMap<>();
271 
272     public VarSymbol getClassField(Type type, Types types) {
273         return classFields.computeIfAbsent(
274             new UniqueType(type, types), k -> {
275                 Type arg = null;
276                 if (type.getTag() == ARRAY || type.getTag() == CLASS)
277                     arg = types.erasure(type);
278                 else if (type.isPrimitiveOrVoid())
279                     arg = types.boxedClass(type).type;
280                 else
281                     throw new AssertionError(type);
282 
283                 Type t = new ClassType(
284                     classType.getEnclosingType(), List.of(arg), classType.tsym);
285                 return new VarSymbol(
286                     STATIC | PUBLIC | FINAL, names._class, t, type.tsym);
287             });
288     }
289 
290     public void initType(Type type, ClassSymbol c) {
291         type.tsym = c;
292         typeOfTag[type.getTag().ordinal()] = type;
293     }
294 
295     public void initType(Type type, String name) {
296         initType(
297             type,
298             new ClassSymbol(
299                 PUBLIC, names.fromString(name), type, rootPackage));
300     }
301 
302     public void initType(Type type, String name, String bname) {
303         initType(type, name);
304         boxedName[type.getTag().ordinal()] = names.fromString("java.lang." + bname);
305     }
306 
307     /** The class symbol that owns all predefined symbols.
308      */
309     public final ClassSymbol predefClass;
310 
311     /** Enter a class into symbol table.
312      *  @param s The name of the class.
313      */
314     private Type enterClass(String s) {
315         return enterClass(java_base, names.fromString(s)).type;
316     }
317 
318     public void synthesizeEmptyInterfaceIfMissing(final Type type) {
319         final Completer completer = type.tsym.completer;
320         type.tsym.completer = new Completer() {
321             @Override
322             public void complete(Symbol sym) throws CompletionFailure {
323                 try {
324                     completer.complete(sym);
325                 } catch (CompletionFailure e) {
326                     sym.flags_field |= (PUBLIC | INTERFACE);
327                     ((ClassType) sym.type).supertype_field = objectType;
328                 }
329             }
330 
331             @Override
332             public boolean isTerminal() {
333                 return completer.isTerminal();
334             }
335         };
336     }
337 
338     public void synthesizeBoxTypeIfMissing(final Type type) {
339         ClassSymbol sym = enterClass(java_base, boxedName[type.getTag().ordinal()]);
340         final Completer completer = sym.completer;
341         sym.completer = new Completer() {
342             @Override
343             public void complete(Symbol sym) throws CompletionFailure {
344                 try {
345                     completer.complete(sym);
346                 } catch (CompletionFailure e) {
347                     sym.flags_field |= PUBLIC;
348                     ((ClassType) sym.type).supertype_field = objectType;
349                     MethodSymbol boxMethod =
350                         new MethodSymbol(PUBLIC | STATIC, names.valueOf,
351                                          new MethodType(List.of(type), sym.type,
352                                 List.nil(), methodClass),
353                             sym);
354                     sym.members().enter(boxMethod);
355                     MethodSymbol unboxMethod =
356                         new MethodSymbol(PUBLIC,
357                             type.tsym.name.append(names.Value), // x.intValue()
358                             new MethodType(List.nil(), type,
359                                 List.nil(), methodClass),
360                             sym);
361                     sym.members().enter(unboxMethod);
362                 }
363             }
364 
365             @Override
366             public boolean isTerminal() {
367                 return completer.isTerminal();
368             }
369         };
370     }
371 
372     // Enter a synthetic class that is used to mark classes in ct.sym.
373     // This class does not have a class file.
374     private Type enterSyntheticAnnotation(String name) {
375         // for now, leave the module null, to prevent problems from synthesizing the
376         // existence of a class in any specific module, including noModule
377         ClassType type = (ClassType)enterClass(java_base, names.fromString(name)).type;
378         ClassSymbol sym = (ClassSymbol)type.tsym;
379         sym.completer = Completer.NULL_COMPLETER;
380         sym.flags_field = PUBLIC|ACYCLIC|ANNOTATION|INTERFACE;
381         sym.erasure_field = type;
382         sym.members_field = WriteableScope.create(sym);
383         type.typarams_field = List.nil();
384         type.allparams_field = List.nil();
385         type.supertype_field = annotationType;
386         type.interfaces_field = List.nil();
387         return type;
388     }
389 
390     /** Constructor; enters all predefined identifiers and operators
391      *  into symbol table.
392      */
393     protected Symtab(Context context) throws CompletionFailure {
394         context.put(symtabKey, this);
395 
396         names = Names.instance(context);
397 
398         // Create the unknown type
399         unknownType = new UnknownType();
400 
401         messages = JavacMessages.instance(context);
402 
403         MissingInfoHandler missingInfoHandler = MissingInfoHandler.instance(context);
404 
405         Target target = Target.instance(context);
406         rootPackage = new RootPackageSymbol(names.empty, null,
407                                             missingInfoHandler,
408                                             target.runtimeUseNestAccess());
409 
410         // create the basic builtin symbols
411         unnamedModule = new ModuleSymbol(names.empty, null) {
412                 {
413                     directives = List.nil();
414                     exports = List.nil();
415                     provides = List.nil();
416                     uses = List.nil();
417                     ModuleSymbol java_base = enterModule(names.java_base);
418                     com.sun.tools.javac.code.Directive.RequiresDirective d =
419                             new com.sun.tools.javac.code.Directive.RequiresDirective(java_base,
420                                     EnumSet.of(com.sun.tools.javac.code.Directive.RequiresFlag.MANDATED));
421                     requires = List.of(d);
422                 }
423                 @Override
424                 public String toString() {
425                     return messages.getLocalizedString("compiler.misc.unnamed.module");
426                 }
427             };
428         addRootPackageFor(unnamedModule);
429         unnamedModule.enclosedPackages = unnamedModule.enclosedPackages.prepend(unnamedModule.unnamedPackage);
430 
431         errModule = new ModuleSymbol(names.empty, null) {
432                 {
433                     directives = List.nil();
434                     exports = List.nil();
435                     provides = List.nil();
436                     uses = List.nil();
437                     ModuleSymbol java_base = enterModule(names.java_base);
438                     com.sun.tools.javac.code.Directive.RequiresDirective d =
439                             new com.sun.tools.javac.code.Directive.RequiresDirective(java_base,
440                                     EnumSet.of(com.sun.tools.javac.code.Directive.RequiresFlag.MANDATED));
441                     requires = List.of(d);
442                 }
443             };
444         addRootPackageFor(errModule);
445 
446         noModule = new ModuleSymbol(names.empty, null) {
447             @Override public boolean isNoModule() {
448                 return true;
449             }
450         };
451         addRootPackageFor(noModule);
452 
453         noSymbol = new TypeSymbol(NIL, 0, names.empty, Type.noType, rootPackage) {
454             @Override @DefinedBy(Api.LANGUAGE_MODEL)
455             public <R, P> R accept(ElementVisitor<R, P> v, P p) {
456                 return v.visitUnknown(this, p);
457             }
458         };
459 
460         // create the error symbols
461         errSymbol = new ClassSymbol(PUBLIC|STATIC|ACYCLIC, names.any, null, rootPackage);
462         errType = new ErrorType(errSymbol, Type.noType);
463 
464         unknownSymbol = new ClassSymbol(PUBLIC|STATIC|ACYCLIC, names.fromString("<any?>"), null, rootPackage);
465         unknownSymbol.members_field = new Scope.ErrorScope(unknownSymbol);
466         unknownSymbol.type = unknownType;
467 
468         // initialize builtin types
469         initType(byteType, "byte", "Byte");
470         initType(shortType, "short", "Short");
471         initType(charType, "char", "Character");
472         initType(intType, "int", "Integer");
473         initType(longType, "long", "Long");
474         initType(floatType, "float", "Float");
475         initType(doubleType, "double", "Double");
476         initType(booleanType, "boolean", "Boolean");
477         initType(voidType, "void", "Void");
478         initType(botType, "<nulltype>");
479         initType(errType, errSymbol);
480         initType(unknownType, unknownSymbol);
481 
482         // the builtin class of all arrays
483         arrayClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Array, noSymbol);
484 
485         // VGJ
486         boundClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Bound, noSymbol);
487         boundClass.members_field = new Scope.ErrorScope(boundClass);
488 
489         // the builtin class of all methods
490         methodClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Method, noSymbol);
491         methodClass.members_field = new Scope.ErrorScope(boundClass);
492 
493         // Create class to hold all predefined constants and operations.
494         predefClass = new ClassSymbol(PUBLIC|ACYCLIC, names.empty, rootPackage);
495         WriteableScope scope = WriteableScope.create(predefClass);
496         predefClass.members_field = scope;
497 
498         // Get the initial completer for Symbols from the ClassFinder
499         initialCompleter = ClassFinder.instance(context).getCompleter();
500         rootPackage.members_field = WriteableScope.create(rootPackage);
501 
502         // Enter symbols for basic types.
503         scope.enter(byteType.tsym);
504         scope.enter(shortType.tsym);
505         scope.enter(charType.tsym);
506         scope.enter(intType.tsym);
507         scope.enter(longType.tsym);
508         scope.enter(floatType.tsym);
509         scope.enter(doubleType.tsym);
510         scope.enter(booleanType.tsym);
511         scope.enter(errType.tsym);
512 
513         // Enter symbol for the errSymbol
514         scope.enter(errSymbol);
515 
516         Source source = Source.instance(context);
517         if (Feature.MODULES.allowedInSource(source)) {
518             java_base = enterModule(names.java_base);
519             //avoid completing java.base during the Symtab initialization
520             java_base.completer = Completer.NULL_COMPLETER;
521             java_base.visiblePackages = Collections.emptyMap();
522         } else {
523             java_base = noModule;
524         }
525 
526         // Get the initial completer for ModuleSymbols from Modules
527         moduleCompleter = Modules.instance(context).getCompleter();
528 
529         // Enter predefined classes. All are assumed to be in the java.base module.
530         objectType = enterClass("java.lang.Object");
531         objectMethodsType = enterClass("java.lang.runtime.ObjectMethods");
532         objectsType = enterClass("java.util.Objects");
533         classType = enterClass("java.lang.Class");
534         stringType = enterClass("java.lang.String");
535         stringBufferType = enterClass("java.lang.StringBuffer");
536         stringBuilderType = enterClass("java.lang.StringBuilder");
537         cloneableType = enterClass("java.lang.Cloneable");
538         throwableType = enterClass("java.lang.Throwable");
539         serializableType = enterClass("java.io.Serializable");
540         serializedLambdaType = enterClass("java.lang.invoke.SerializedLambda");
541         varHandleType = enterClass("java.lang.invoke.VarHandle");
542         methodHandleType = enterClass("java.lang.invoke.MethodHandle");
543         methodHandleLookupType = enterClass("java.lang.invoke.MethodHandles$Lookup");
544         methodTypeType = enterClass("java.lang.invoke.MethodType");
545         errorType = enterClass("java.lang.Error");
546         illegalArgumentExceptionType = enterClass("java.lang.IllegalArgumentException");
547         interruptedExceptionType = enterClass("java.lang.InterruptedException");
548         exceptionType = enterClass("java.lang.Exception");
549         runtimeExceptionType = enterClass("java.lang.RuntimeException");
550         classNotFoundExceptionType = enterClass("java.lang.ClassNotFoundException");
551         noClassDefFoundErrorType = enterClass("java.lang.NoClassDefFoundError");
552         noSuchFieldErrorType = enterClass("java.lang.NoSuchFieldError");
553         assertionErrorType = enterClass("java.lang.AssertionError");
554         incompatibleClassChangeErrorType = enterClass("java.lang.IncompatibleClassChangeError");
555         cloneNotSupportedExceptionType = enterClass("java.lang.CloneNotSupportedException");
556         annotationType = enterClass("java.lang.annotation.Annotation");
557         classLoaderType = enterClass("java.lang.ClassLoader");
558         enumSym = enterClass(java_base, names.java_lang_Enum);
559         enumFinalFinalize =
560             new MethodSymbol(PROTECTED|FINAL|HYPOTHETICAL,
561                              names.finalize,
562                              new MethodType(List.nil(), voidType,
563                                             List.nil(), methodClass),
564                              enumSym);
565         listType = enterClass("java.util.List");
566         collectionsType = enterClass("java.util.Collections");
567         comparableType = enterClass("java.lang.Comparable");
568         comparatorType = enterClass("java.util.Comparator");
569         arraysType = enterClass("java.util.Arrays");
570         iterableType = enterClass("java.lang.Iterable");
571         iteratorType = enterClass("java.util.Iterator");
572         annotationTargetType = enterClass("java.lang.annotation.Target");
573         overrideType = enterClass("java.lang.Override");
574         retentionType = enterClass("java.lang.annotation.Retention");
575         deprecatedType = enterClass("java.lang.Deprecated");
576         suppressWarningsType = enterClass("java.lang.SuppressWarnings");
577         supplierType = enterClass("java.util.function.Supplier");
578         inheritedType = enterClass("java.lang.annotation.Inherited");
579         repeatableType = enterClass("java.lang.annotation.Repeatable");
580         documentedType = enterClass("java.lang.annotation.Documented");
581         elementTypeType = enterClass("java.lang.annotation.ElementType");
582         systemType = enterClass("java.lang.System");
583         autoCloseableType = enterClass("java.lang.AutoCloseable");
584         autoCloseableClose = new MethodSymbol(PUBLIC,
585                              names.close,
586                              new MethodType(List.nil(), voidType,
587                                             List.of(exceptionType), methodClass),
588                              autoCloseableType.tsym);
589         trustMeType = enterClass("java.lang.SafeVarargs");
590         nativeHeaderType = enterClass("java.lang.annotation.Native");
591         lambdaMetafactory = enterClass("java.lang.invoke.LambdaMetafactory");
592         stringConcatFactory = enterClass("java.lang.invoke.StringConcatFactory");
593         functionalInterfaceType = enterClass("java.lang.FunctionalInterface");
594         previewFeatureType = enterClass("jdk.internal.javac.PreviewFeature");
595         previewFeatureInternalType = enterSyntheticAnnotation("jdk.internal.PreviewFeature+Annotation");
596         typeDescriptorType = enterClass("java.lang.invoke.TypeDescriptor");
597         recordType = enterClass("java.lang.Record");
598         switchBootstrapsType = enterClass("java.lang.runtime.SwitchBootstraps");
599         valueBasedType = enterClass("jdk.internal.ValueBased");
600         valueBasedInternalType = enterSyntheticAnnotation("jdk.internal.ValueBased+Annotation");
601         // For serialization lint checking
602         objectStreamFieldType = enterClass("java.io.ObjectStreamField");
603         objectInputStreamType = enterClass("java.io.ObjectInputStream");
604         objectOutputStreamType = enterClass("java.io.ObjectOutputStream");
605         ioExceptionType = enterClass("java.io.IOException");
606         objectStreamExceptionType = enterClass("java.io.ObjectStreamException");
607         externalizableType = enterClass("java.io.Externalizable");
608 
609         synthesizeEmptyInterfaceIfMissing(autoCloseableType);
610         synthesizeEmptyInterfaceIfMissing(cloneableType);
611         synthesizeEmptyInterfaceIfMissing(serializableType);
612         synthesizeEmptyInterfaceIfMissing(lambdaMetafactory);
613         synthesizeEmptyInterfaceIfMissing(serializedLambdaType);
614         synthesizeEmptyInterfaceIfMissing(stringConcatFactory);
615         synthesizeBoxTypeIfMissing(doubleType);
616         synthesizeBoxTypeIfMissing(floatType);
617         synthesizeBoxTypeIfMissing(voidType);
618 
619         // Enter a synthetic class that is used to mark internal
620         // proprietary classes in ct.sym.  This class does not have a
621         // class file.
622         proprietaryType = enterSyntheticAnnotation("sun.Proprietary+Annotation");
623 
624         // Enter a synthetic class that is used to provide profile info for
625         // classes in ct.sym.  This class does not have a class file.
626         profileType = enterSyntheticAnnotation("jdk.Profile+Annotation");
627         MethodSymbol m = new MethodSymbol(PUBLIC | ABSTRACT, names.value, intType, profileType.tsym);
628         profileType.tsym.members().enter(m);
629 
630         // Enter a class for arrays.
631         // The class implements java.lang.Cloneable and java.io.Serializable.
632         // It has a final length field and a clone method.
633         ClassType arrayClassType = (ClassType)arrayClass.type;
634         arrayClassType.supertype_field = objectType;
635         arrayClassType.interfaces_field = List.of(cloneableType, serializableType);
636         arrayClass.members_field = WriteableScope.create(arrayClass);
637         lengthVar = new VarSymbol(
638             PUBLIC | FINAL,
639             names.length,
640             intType,
641             arrayClass);
642         arrayClass.members().enter(lengthVar);
643         arrayCloneMethod = new MethodSymbol(
644             PUBLIC,
645             names.clone,
646             new MethodType(List.nil(), objectType,
647                            List.nil(), methodClass),
648             arrayClass);
649         arrayClass.members().enter(arrayCloneMethod);
650 
651         if (java_base != noModule)
652             java_base.completer = moduleCompleter::complete; //bootstrap issues
653 
654     }
655 
656     /** Define a new class given its name and owner.
657      */
658     public ClassSymbol defineClass(Name name, Symbol owner) {
659         ClassSymbol c = new ClassSymbol(0, name, owner);
660         c.completer = initialCompleter;
661         return c;
662     }
663 
664     /** Create a new toplevel or member class symbol with given name
665      *  and owner and enter in `classes' unless already there.
666      */
667     public ClassSymbol enterClass(ModuleSymbol msym, Name name, TypeSymbol owner) {
668         Assert.checkNonNull(msym);
669         Name flatname = TypeSymbol.formFlatName(name, owner);
670         ClassSymbol c = getClass(msym, flatname);
671         if (c == null) {
672             c = defineClass(name, owner);
673             doEnterClass(msym, c);
674         } else if ((c.name != name || c.owner != owner) && owner.kind == TYP && c.owner.kind == PCK) {
675             // reassign fields of classes that might have been loaded with
676             // their flat names.
677             c.owner.members().remove(c);
678             c.name = name;
679             c.owner = owner;
680             c.fullname = ClassSymbol.formFullName(name, owner);
681         }
682         return c;
683     }
684 
685     public ClassSymbol getClass(ModuleSymbol msym, Name flatName) {
686         Assert.checkNonNull(msym, flatName::toString);
687         return classes.getOrDefault(flatName, Collections.emptyMap()).get(msym);
688     }
689 
690     public PackageSymbol lookupPackage(ModuleSymbol msym, Name flatName) {
691         return lookupPackage(msym, flatName, false);
692     }
693 
694     private PackageSymbol lookupPackage(ModuleSymbol msym, Name flatName, boolean onlyExisting) {
695         Assert.checkNonNull(msym);
696 
697         if (flatName.isEmpty()) {
698             //unnamed packages only from the current module - visiblePackages contains *root* package, not unnamed package!
699             return msym.unnamedPackage;
700         }
701 
702         if (msym == noModule) {
703             return enterPackage(msym, flatName);
704         }
705 
706         msym.complete();
707 
708         PackageSymbol pack;
709 
710         pack = msym.visiblePackages.get(flatName);
711 
712         if (pack != null)
713             return pack;
714 
715         pack = getPackage(msym, flatName);
716 
717         if ((pack != null && pack.exists()) || onlyExisting)
718             return pack;
719 
720         boolean dependsOnUnnamed = msym.requires != null &&
721                                    msym.requires.stream()
722                                                 .map(rd -> rd.module)
723                                                 .anyMatch(mod -> mod == unnamedModule);
724 
725         if (dependsOnUnnamed) {
726             //msyms depends on the unnamed module, for which we generally don't know
727             //the list of packages it "exports" ahead of time. So try to lookup the package in the
728             //current module, and in the unnamed module and see if it exists in one of them
729             PackageSymbol unnamedPack = getPackage(unnamedModule, flatName);
730 
731             if (unnamedPack != null && unnamedPack.exists()) {
732                 msym.visiblePackages.put(unnamedPack.fullname, unnamedPack);
733                 return unnamedPack;
734             }
735 
736             pack = enterPackage(msym, flatName);
737             pack.complete();
738             if (pack.exists())
739                 return pack;
740 
741             unnamedPack = enterPackage(unnamedModule, flatName);
742             unnamedPack.complete();
743             if (unnamedPack.exists()) {
744                 msym.visiblePackages.put(unnamedPack.fullname, unnamedPack);
745                 return unnamedPack;
746             }
747 
748             return pack;
749         }
750 
751         return enterPackage(msym, flatName);
752     }
753 
754     private static final Map<ModuleSymbol, ClassSymbol> EMPTY = new HashMap<>();
755 
756     public void removeClass(ModuleSymbol msym, Name flatName) {
757         classes.getOrDefault(flatName, EMPTY).remove(msym);
758     }
759 
760     public Iterable<ClassSymbol> getAllClasses() {
761         return () -> Iterators.createCompoundIterator(classes.values(), v -> v.values().iterator());
762     }
763 
764     private void doEnterClass(ModuleSymbol msym, ClassSymbol cs) {
765         classes.computeIfAbsent(cs.flatname, n -> new HashMap<>()).put(msym, cs);
766     }
767 
768     /** Create a new member or toplevel class symbol with given flat name
769      *  and enter in `classes' unless already there.
770      */
771     public ClassSymbol enterClass(ModuleSymbol msym, Name flatname) {
772         Assert.checkNonNull(msym);
773         PackageSymbol ps = lookupPackage(msym, Convert.packagePart(flatname));
774         Assert.checkNonNull(ps);
775         Assert.checkNonNull(ps.modle);
776         ClassSymbol c = getClass(ps.modle, flatname);
777         if (c == null) {
778             c = defineClass(Convert.shortName(flatname), ps);
779             doEnterClass(ps.modle, c);
780             return c;
781         } else
782             return c;
783     }
784 
785     /** Check to see if a package exists, given its fully qualified name.
786      */
787     public boolean packageExists(ModuleSymbol msym, Name fullname) {
788         Assert.checkNonNull(msym);
789         PackageSymbol pack = lookupPackage(msym, fullname, true);
790         return pack != null && pack.exists();
791     }
792 
793     /** Make a package, given its fully qualified name.
794      */
795     public PackageSymbol enterPackage(ModuleSymbol currModule, Name fullname) {
796         Assert.checkNonNull(currModule);
797         PackageSymbol p = getPackage(currModule, fullname);
798         if (p == null) {
799             Assert.check(!fullname.isEmpty(), () -> "rootPackage missing!; currModule: " + currModule);
800             p = new PackageSymbol(
801                     Convert.shortName(fullname),
802                     enterPackage(currModule, Convert.packagePart(fullname)));
803             p.completer = initialCompleter;
804             p.modle = currModule;
805             doEnterPackage(currModule, p);
806         }
807         return p;
808     }
809 
810     private void doEnterPackage(ModuleSymbol msym, PackageSymbol pack) {
811         packages.computeIfAbsent(pack.fullname, n -> new HashMap<>()).put(msym, pack);
812         msym.enclosedPackages = msym.enclosedPackages.prepend(pack);
813     }
814 
815     private void addRootPackageFor(ModuleSymbol module) {
816         doEnterPackage(module, rootPackage);
817         PackageSymbol unnamedPackage = new PackageSymbol(names.empty, rootPackage) {
818                 @Override
819                 public String toString() {
820                     return messages.getLocalizedString("compiler.misc.unnamed.package");
821                 }
822             };
823         unnamedPackage.modle = module;
824         //we cannot use a method reference below, as initialCompleter might be null now
825         unnamedPackage.completer = s -> initialCompleter.complete(s);
826         unnamedPackage.flags_field |= EXISTS;
827         module.unnamedPackage = unnamedPackage;
828     }
829 
830     public PackageSymbol getPackage(ModuleSymbol module, Name fullname) {
831         return packages.getOrDefault(fullname, Collections.emptyMap()).get(module);
832     }
833 
834     public ModuleSymbol enterModule(Name name) {
835         ModuleSymbol msym = modules.get(name);
836         if (msym == null) {
837             msym = ModuleSymbol.create(name, names.module_info);
838             addRootPackageFor(msym);
839             msym.completer = s -> moduleCompleter.complete(s); //bootstrap issues
840             modules.put(name, msym);
841         }
842         return msym;
843     }
844 
845     public ModuleSymbol getModule(Name name) {
846         return modules.get(name);
847     }
848 
849     //temporary:
850     public ModuleSymbol inferModule(Name packageName) {
851         if (packageName.isEmpty())
852             return java_base == noModule ? noModule : unnamedModule;//!
853 
854         ModuleSymbol msym = null;
855         Map<ModuleSymbol,PackageSymbol> map = packages.get(packageName);
856         if (map == null)
857             return null;
858         for (Map.Entry<ModuleSymbol,PackageSymbol> e: map.entrySet()) {
859             if (!e.getValue().members().isEmpty()) {
860                 if (msym == null) {
861                     msym = e.getKey();
862                 } else {
863                     return null;
864                 }
865             }
866         }
867         return msym;
868     }
869 
870     public List<ModuleSymbol> listPackageModules(Name packageName) {
871         if (packageName.isEmpty())
872             return List.nil();
873 
874         List<ModuleSymbol> result = List.nil();
875         Map<ModuleSymbol,PackageSymbol> map = packages.get(packageName);
876         if (map != null) {
877             for (Map.Entry<ModuleSymbol, PackageSymbol> e: map.entrySet()) {
878                 if (!e.getValue().members().isEmpty()) {
879                     result = result.prepend(e.getKey());
880                 }
881             }
882         }
883         return result;
884     }
885 
886     public Collection<ModuleSymbol> getAllModules() {
887         return modules.values();
888     }
889 
890     public Iterable<ClassSymbol> getClassesForName(Name candidate) {
891         return classes.getOrDefault(candidate, Collections.emptyMap()).values();
892     }
893 
894     public Iterable<PackageSymbol> getPackagesForName(Name candidate) {
895         return packages.getOrDefault(candidate, Collections.emptyMap()).values();
896     }
897 }