1 /*
  2  * Copyright (c) 1999, 2024, 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 restrictedInternalType;
226     public final Type typeDescriptorType;
227     public final Type recordType;
228     public final Type switchBootstrapsType;
229     public final Type constantBootstrapsType;
230     public final Type valueBasedType;
231     public final Type valueBasedInternalType;
232     public final Type classDescType;
233     public final Type enumDescType;
234     public final Type ioType;
235 
236     // For serialization lint checking
237     public final Type objectStreamFieldType;
238     public final Type objectInputStreamType;
239     public final Type objectOutputStreamType;
240     public final Type ioExceptionType;
241     public final Type objectStreamExceptionType;
242     // For externalization lint checking
243     public final Type externalizableType;
244     public final Type objectInputType;
245     public final Type objectOutputType;
246 
247     /** The symbol representing the length field of an array.
248      */
249     public final VarSymbol lengthVar;
250 
251     /** The symbol representing the final finalize method on enums */
252     public final MethodSymbol enumFinalFinalize;
253 
254     /** The symbol representing the close method on TWR AutoCloseable type */
255     public final MethodSymbol autoCloseableClose;
256 
257     /** The predefined type that belongs to a tag.
258      */
259     public final Type[] typeOfTag = new Type[TypeTag.getTypeTagCount()];
260 
261     /** The name of the class that belongs to a basic type tag.
262      */
263     public final Name[] boxedName = new Name[TypeTag.getTypeTagCount()];
264 
265     /** A hashtable containing the encountered top-level and member classes,
266      *  indexed by flat names. The table does not contain local classes.
267      *  It should be updated from the outside to reflect classes defined
268      *  by compiled source files.
269      */
270     private final Map<Name, Map<ModuleSymbol,ClassSymbol>> classes = new HashMap<>();
271 
272     /** A hashtable containing the encountered packages.
273      *  the table should be updated from outside to reflect packages defined
274      *  by compiled source files.
275      */
276     private final Map<Name, Map<ModuleSymbol,PackageSymbol>> packages = new HashMap<>();
277 
278     /** A hashtable giving the encountered modules.
279      */
280     private final Map<Name, ModuleSymbol> modules = new LinkedHashMap<>();
281 
282     private final Map<Types.UniqueType, VarSymbol> classFields = new HashMap<>();
283 
284     public VarSymbol getClassField(Type type, Types types) {
285         return classFields.computeIfAbsent(
286             new UniqueType(type, types), k -> {
287                 Type arg = null;
288                 if (type.getTag() == ARRAY || type.getTag() == CLASS)
289                     arg = types.erasure(type);
290                 else if (type.isPrimitiveOrVoid())
291                     arg = types.boxedClass(type).type;
292                 else
293                     throw new AssertionError(type);
294 
295                 Type t = new ClassType(
296                     classType.getEnclosingType(), List.of(arg), classType.tsym);
297                 return new VarSymbol(
298                     STATIC | PUBLIC | FINAL, names._class, t, type.tsym);
299             });
300     }
301 
302     public void initType(Type type, ClassSymbol c) {
303         type.tsym = c;
304         typeOfTag[type.getTag().ordinal()] = type;
305     }
306 
307     public void initType(Type type, String name) {
308         initType(
309             type,
310             new ClassSymbol(
311                 PUBLIC, names.fromString(name), type, rootPackage));
312     }
313 
314     public void initType(Type type, String name, String bname) {
315         initType(type, name);
316         boxedName[type.getTag().ordinal()] = names.fromString("java.lang." + bname);
317     }
318 
319     /** The class symbol that owns all predefined symbols.
320      */
321     public final ClassSymbol predefClass;
322 
323     /** Enter a class into symbol table.
324      *  @param s The name of the class.
325      */
326     private Type enterClass(String s) {
327         return enterClass(java_base, names.fromString(s)).type;
328     }
329 
330     public void synthesizeEmptyInterfaceIfMissing(final Type type) {
331         final Completer completer = type.tsym.completer;
332         type.tsym.completer = new Completer() {
333             @Override
334             public void complete(Symbol sym) throws CompletionFailure {
335                 try {
336                     completer.complete(sym);
337                 } catch (CompletionFailure e) {
338                     sym.flags_field |= (PUBLIC | INTERFACE);
339                     ((ClassType) sym.type).supertype_field = objectType;
340                 }
341             }
342 
343             @Override
344             public boolean isTerminal() {
345                 return completer.isTerminal();
346             }
347         };
348     }
349 
350     public void synthesizeBoxTypeIfMissing(final Type type) {
351         ClassSymbol sym = enterClass(java_base, boxedName[type.getTag().ordinal()]);
352         final Completer completer = sym.completer;
353         sym.completer = new Completer() {
354             @Override
355             public void complete(Symbol sym) throws CompletionFailure {
356                 try {
357                     completer.complete(sym);
358                 } catch (CompletionFailure e) {
359                     sym.flags_field |= PUBLIC;
360                     ((ClassType) sym.type).supertype_field = objectType;
361                     MethodSymbol boxMethod =
362                         new MethodSymbol(PUBLIC | STATIC, names.valueOf,
363                                          new MethodType(List.of(type), sym.type,
364                                 List.nil(), methodClass),
365                             sym);
366                     sym.members().enter(boxMethod);
367                     MethodSymbol unboxMethod =
368                         new MethodSymbol(PUBLIC,
369                             type.tsym.name.append(names.Value), // x.intValue()
370                             new MethodType(List.nil(), type,
371                                 List.nil(), methodClass),
372                             sym);
373                     sym.members().enter(unboxMethod);
374                 }
375             }
376 
377             @Override
378             public boolean isTerminal() {
379                 return completer.isTerminal();
380             }
381         };
382     }
383 
384     // Enter a synthetic class that is used to mark classes in ct.sym.
385     // This class does not have a class file.
386     private Type enterSyntheticAnnotation(String name) {
387         // for now, leave the module null, to prevent problems from synthesizing the
388         // existence of a class in any specific module, including noModule
389         ClassType type = (ClassType)enterClass(java_base, names.fromString(name)).type;
390         ClassSymbol sym = (ClassSymbol)type.tsym;
391         sym.completer = Completer.NULL_COMPLETER;
392         sym.flags_field = PUBLIC|ACYCLIC|ANNOTATION|INTERFACE;
393         sym.erasure_field = type;
394         sym.members_field = WriteableScope.create(sym);
395         type.typarams_field = List.nil();
396         type.allparams_field = List.nil();
397         type.supertype_field = annotationType;
398         type.interfaces_field = List.nil();
399         return type;
400     }
401 
402     /** Constructor; enters all predefined identifiers and operators
403      *  into symbol table.
404      */
405     @SuppressWarnings("this-escape")
406     protected Symtab(Context context) throws CompletionFailure {
407         context.put(symtabKey, this);
408 
409         names = Names.instance(context);
410 
411         // Create the unknown type
412         unknownType = new UnknownType();
413 
414         messages = JavacMessages.instance(context);
415 
416         MissingInfoHandler missingInfoHandler = MissingInfoHandler.instance(context);
417 
418         Target target = Target.instance(context);
419         rootPackage = new RootPackageSymbol(names.empty, null,
420                                             missingInfoHandler,
421                                             target.runtimeUseNestAccess());
422 
423         // create the basic builtin symbols
424         unnamedModule = new ModuleSymbol(names.empty, null) {
425                 {
426                     directives = List.nil();
427                     exports = List.nil();
428                     provides = List.nil();
429                     uses = List.nil();
430                     ModuleSymbol java_base = enterModule(names.java_base);
431                     com.sun.tools.javac.code.Directive.RequiresDirective d =
432                             new com.sun.tools.javac.code.Directive.RequiresDirective(java_base,
433                                     EnumSet.of(com.sun.tools.javac.code.Directive.RequiresFlag.MANDATED));
434                     requires = List.of(d);
435                 }
436                 @Override
437                 public String toString() {
438                     return messages.getLocalizedString("compiler.misc.unnamed.module");
439                 }
440             };
441         addRootPackageFor(unnamedModule);
442         unnamedModule.enclosedPackages = unnamedModule.enclosedPackages.prepend(unnamedModule.unnamedPackage);
443 
444         errModule = new ModuleSymbol(names.empty, null) {
445                 {
446                     directives = List.nil();
447                     exports = List.nil();
448                     provides = List.nil();
449                     uses = List.nil();
450                     ModuleSymbol java_base = enterModule(names.java_base);
451                     com.sun.tools.javac.code.Directive.RequiresDirective d =
452                             new com.sun.tools.javac.code.Directive.RequiresDirective(java_base,
453                                     EnumSet.of(com.sun.tools.javac.code.Directive.RequiresFlag.MANDATED));
454                     requires = List.of(d);
455                 }
456             };
457         addRootPackageFor(errModule);
458 
459         noModule = new ModuleSymbol(names.empty, null) {
460             @Override public boolean isNoModule() {
461                 return true;
462             }
463         };
464         addRootPackageFor(noModule);
465 
466         noSymbol = new TypeSymbol(NIL, 0, names.empty, Type.noType, rootPackage) {
467             @Override @DefinedBy(Api.LANGUAGE_MODEL)
468             public <R, P> R accept(ElementVisitor<R, P> v, P p) {
469                 return v.visitUnknown(this, p);
470             }
471         };
472 
473         // create the error symbols
474         errSymbol = new ClassSymbol(PUBLIC|STATIC|ACYCLIC, names.any, null, rootPackage);
475         errType = new ErrorType(errSymbol, Type.noType);
476 
477         unknownSymbol = new ClassSymbol(PUBLIC|STATIC|ACYCLIC, names.fromString("<any?>"), null, rootPackage);
478         unknownSymbol.members_field = new Scope.ErrorScope(unknownSymbol);
479         unknownSymbol.type = unknownType;
480 
481         // initialize builtin types
482         initType(byteType, "byte", "Byte");
483         initType(shortType, "short", "Short");
484         initType(charType, "char", "Character");
485         initType(intType, "int", "Integer");
486         initType(longType, "long", "Long");
487         initType(floatType, "float", "Float");
488         initType(doubleType, "double", "Double");
489         initType(booleanType, "boolean", "Boolean");
490         initType(voidType, "void", "Void");
491         initType(botType, "<nulltype>");
492         initType(errType, errSymbol);
493         initType(unknownType, unknownSymbol);
494 
495         // the builtin class of all arrays
496         arrayClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Array, noSymbol);
497 
498         // VGJ
499         boundClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Bound, noSymbol);
500         boundClass.members_field = new Scope.ErrorScope(boundClass);
501 
502         // the builtin class of all methods
503         methodClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Method, noSymbol);
504         methodClass.members_field = new Scope.ErrorScope(boundClass);
505 
506         // Create class to hold all predefined constants and operations.
507         predefClass = new ClassSymbol(PUBLIC|ACYCLIC, names.empty, rootPackage);
508         WriteableScope scope = WriteableScope.create(predefClass);
509         predefClass.members_field = scope;
510 
511         // Get the initial completer for Symbols from the ClassFinder
512         initialCompleter = ClassFinder.instance(context).getCompleter();
513         rootPackage.members_field = WriteableScope.create(rootPackage);
514 
515         // Enter symbols for basic types.
516         scope.enter(byteType.tsym);
517         scope.enter(shortType.tsym);
518         scope.enter(charType.tsym);
519         scope.enter(intType.tsym);
520         scope.enter(longType.tsym);
521         scope.enter(floatType.tsym);
522         scope.enter(doubleType.tsym);
523         scope.enter(booleanType.tsym);
524         scope.enter(errType.tsym);
525 
526         // Enter symbol for the errSymbol
527         scope.enter(errSymbol);
528 
529         Source source = Source.instance(context);
530         if (Feature.MODULES.allowedInSource(source)) {
531             java_base = enterModule(names.java_base);
532             //avoid completing java.base during the Symtab initialization
533             java_base.completer = Completer.NULL_COMPLETER;
534             java_base.visiblePackages = Collections.emptyMap();
535         } else {
536             java_base = noModule;
537         }
538 
539         // Get the initial completer for ModuleSymbols from Modules
540         moduleCompleter = Modules.instance(context).getCompleter();
541 
542         // Enter predefined classes. All are assumed to be in the java.base module.
543         objectType = enterClass("java.lang.Object");
544         objectMethodsType = enterClass("java.lang.runtime.ObjectMethods");
545         exactConversionsSupportType = enterClass("java.lang.runtime.ExactConversionsSupport");
546         objectsType = enterClass("java.util.Objects");
547         classType = enterClass("java.lang.Class");
548         stringType = enterClass("java.lang.String");
549         stringBufferType = enterClass("java.lang.StringBuffer");
550         stringBuilderType = enterClass("java.lang.StringBuilder");
551         cloneableType = enterClass("java.lang.Cloneable");
552         throwableType = enterClass("java.lang.Throwable");
553         serializableType = enterClass("java.io.Serializable");
554         serializedLambdaType = enterClass("java.lang.invoke.SerializedLambda");
555         varHandleType = enterClass("java.lang.invoke.VarHandle");
556         methodHandleType = enterClass("java.lang.invoke.MethodHandle");
557         methodHandlesType = enterClass("java.lang.invoke.MethodHandles");
558         methodHandleLookupType = enterClass("java.lang.invoke.MethodHandles$Lookup");
559         methodTypeType = enterClass("java.lang.invoke.MethodType");
560         errorType = enterClass("java.lang.Error");
561         illegalArgumentExceptionType = enterClass("java.lang.IllegalArgumentException");
562         interruptedExceptionType = enterClass("java.lang.InterruptedException");
563         exceptionType = enterClass("java.lang.Exception");
564         runtimeExceptionType = enterClass("java.lang.RuntimeException");
565         classNotFoundExceptionType = enterClass("java.lang.ClassNotFoundException");
566         noClassDefFoundErrorType = enterClass("java.lang.NoClassDefFoundError");
567         noSuchFieldErrorType = enterClass("java.lang.NoSuchFieldError");
568         assertionErrorType = enterClass("java.lang.AssertionError");
569         incompatibleClassChangeErrorType = enterClass("java.lang.IncompatibleClassChangeError");
570         cloneNotSupportedExceptionType = enterClass("java.lang.CloneNotSupportedException");
571         matchExceptionType = enterClass("java.lang.MatchException");
572         annotationType = enterClass("java.lang.annotation.Annotation");
573         classLoaderType = enterClass("java.lang.ClassLoader");
574         enumSym = enterClass(java_base, names.java_lang_Enum);
575         enumFinalFinalize =
576             new MethodSymbol(PROTECTED|FINAL|HYPOTHETICAL,
577                              names.finalize,
578                              new MethodType(List.nil(), voidType,
579                                             List.nil(), methodClass),
580                              enumSym);
581         listType = enterClass("java.util.List");
582         collectionsType = enterClass("java.util.Collections");
583         comparableType = enterClass("java.lang.Comparable");
584         comparatorType = enterClass("java.util.Comparator");
585         arraysType = enterClass("java.util.Arrays");
586         iterableType = enterClass("java.lang.Iterable");
587         iteratorType = enterClass("java.util.Iterator");
588         annotationTargetType = enterClass("java.lang.annotation.Target");
589         overrideType = enterClass("java.lang.Override");
590         retentionType = enterClass("java.lang.annotation.Retention");
591         deprecatedType = enterClass("java.lang.Deprecated");
592         suppressWarningsType = enterClass("java.lang.SuppressWarnings");
593         supplierType = enterClass("java.util.function.Supplier");
594         inheritedType = enterClass("java.lang.annotation.Inherited");
595         repeatableType = enterClass("java.lang.annotation.Repeatable");
596         documentedType = enterClass("java.lang.annotation.Documented");
597         elementTypeType = enterClass("java.lang.annotation.ElementType");
598         systemType = enterClass("java.lang.System");
599         autoCloseableType = enterClass("java.lang.AutoCloseable");
600         autoCloseableClose = new MethodSymbol(PUBLIC,
601                              names.close,
602                              new MethodType(List.nil(), voidType,
603                                             List.of(exceptionType), methodClass),
604                              autoCloseableType.tsym);
605         trustMeType = enterClass("java.lang.SafeVarargs");
606         nativeHeaderType = enterClass("java.lang.annotation.Native");
607         lambdaMetafactory = enterClass("java.lang.invoke.LambdaMetafactory");
608         stringConcatFactory = enterClass("java.lang.invoke.StringConcatFactory");
609         functionalInterfaceType = enterClass("java.lang.FunctionalInterface");
610         previewFeatureType = enterClass("jdk.internal.javac.PreviewFeature");
611         previewFeatureInternalType = enterSyntheticAnnotation("jdk.internal.PreviewFeature+Annotation");
612         restrictedType = enterClass("jdk.internal.javac.Restricted");
613         restrictedInternalType = enterSyntheticAnnotation("jdk.internal.javac.Restricted+Annotation");
614         typeDescriptorType = enterClass("java.lang.invoke.TypeDescriptor");
615         recordType = enterClass("java.lang.Record");
616         switchBootstrapsType = enterClass("java.lang.runtime.SwitchBootstraps");
617         constantBootstrapsType = enterClass("java.lang.invoke.ConstantBootstraps");
618         valueBasedType = enterClass("jdk.internal.ValueBased");
619         valueBasedInternalType = enterSyntheticAnnotation("jdk.internal.ValueBased+Annotation");
620         classDescType = enterClass("java.lang.constant.ClassDesc");
621         enumDescType = enterClass("java.lang.Enum$EnumDesc");
622         ioType = enterClass("java.io.IO");
623         // For serialization lint checking
624         objectStreamFieldType = enterClass("java.io.ObjectStreamField");
625         objectInputStreamType = enterClass("java.io.ObjectInputStream");
626         objectOutputStreamType = enterClass("java.io.ObjectOutputStream");
627         ioExceptionType = enterClass("java.io.IOException");
628         objectStreamExceptionType = enterClass("java.io.ObjectStreamException");
629         externalizableType = enterClass("java.io.Externalizable");
630         objectInputType  = enterClass("java.io.ObjectInput");
631         objectOutputType = enterClass("java.io.ObjectOutput");
632         synthesizeEmptyInterfaceIfMissing(autoCloseableType);
633         synthesizeEmptyInterfaceIfMissing(cloneableType);
634         synthesizeEmptyInterfaceIfMissing(serializableType);
635         synthesizeEmptyInterfaceIfMissing(lambdaMetafactory);
636         synthesizeEmptyInterfaceIfMissing(serializedLambdaType);
637         synthesizeEmptyInterfaceIfMissing(stringConcatFactory);
638         synthesizeBoxTypeIfMissing(doubleType);
639         synthesizeBoxTypeIfMissing(floatType);
640         synthesizeBoxTypeIfMissing(voidType);
641 
642         // Enter a synthetic class that is used to mark internal
643         // proprietary classes in ct.sym.  This class does not have a
644         // class file.
645         proprietaryType = enterSyntheticAnnotation("sun.Proprietary+Annotation");
646 
647         // Enter a synthetic class that is used to provide profile info for
648         // classes in ct.sym.  This class does not have a class file.
649         profileType = enterSyntheticAnnotation("jdk.Profile+Annotation");
650         MethodSymbol m = new MethodSymbol(PUBLIC | ABSTRACT, names.value, intType, profileType.tsym);
651         profileType.tsym.members().enter(m);
652 
653         // Enter a class for arrays.
654         // The class implements java.lang.Cloneable and java.io.Serializable.
655         // It has a final length field and a clone method.
656         ClassType arrayClassType = (ClassType)arrayClass.type;
657         arrayClassType.supertype_field = objectType;
658         arrayClassType.interfaces_field = List.of(cloneableType, serializableType);
659         arrayClass.members_field = WriteableScope.create(arrayClass);
660         lengthVar = new VarSymbol(
661             PUBLIC | FINAL,
662             names.length,
663             intType,
664             arrayClass);
665         arrayClass.members().enter(lengthVar);
666         arrayCloneMethod = new MethodSymbol(
667             PUBLIC,
668             names.clone,
669             new MethodType(List.nil(), objectType,
670                            List.nil(), methodClass),
671             arrayClass);
672         arrayClass.members().enter(arrayCloneMethod);
673 
674         if (java_base != noModule)
675             java_base.completer = moduleCompleter::complete; //bootstrap issues
676 
677     }
678 
679     /** Define a new class given its name and owner.
680      */
681     public ClassSymbol defineClass(Name name, Symbol owner) {
682         ClassSymbol c = new ClassSymbol(0, name, owner);
683         c.completer = initialCompleter;
684         return c;
685     }
686 
687     /** Create a new toplevel or member class symbol with given name
688      *  and owner and enter in `classes' unless already there.
689      */
690     public ClassSymbol enterClass(ModuleSymbol msym, Name name, TypeSymbol owner) {
691         Assert.checkNonNull(msym);
692         Name flatname = TypeSymbol.formFlatName(name, owner);
693         ClassSymbol c = getClass(msym, flatname);
694         if (c == null) {
695             c = defineClass(name, owner);
696             doEnterClass(msym, c);
697         } else if ((c.name != name || c.owner != owner) && owner.kind == TYP &&
698                    c.owner.kind == PCK && ((c.flags_field & FROM_SOURCE) == 0)) {
699             // reassign fields of classes that might have been loaded with
700             // their flat names.
701             c.owner.members().remove(c);
702             c.name = name;
703             c.owner = owner;
704             c.fullname = ClassSymbol.formFullName(name, owner);
705         }
706         return c;
707     }
708 
709     public ClassSymbol getClass(ModuleSymbol msym, Name flatName) {
710         Assert.checkNonNull(msym, flatName::toString);
711         return classes.getOrDefault(flatName, Collections.emptyMap()).get(msym);
712     }
713 
714     public PackageSymbol lookupPackage(ModuleSymbol msym, Name flatName) {
715         return lookupPackage(msym, flatName, false);
716     }
717 
718     private PackageSymbol lookupPackage(ModuleSymbol msym, Name flatName, boolean onlyExisting) {
719         Assert.checkNonNull(msym);
720 
721         if (flatName.isEmpty()) {
722             //unnamed packages only from the current module - visiblePackages contains *root* package, not unnamed package!
723             return msym.unnamedPackage;
724         }
725 
726         if (msym == noModule) {
727             return enterPackage(msym, flatName);
728         }
729 
730         msym.complete();
731 
732         PackageSymbol pack;
733 
734         pack = msym.visiblePackages.get(flatName);
735 
736         if (pack != null)
737             return pack;
738 
739         pack = getPackage(msym, flatName);
740 
741         if ((pack != null && pack.exists()) || onlyExisting)
742             return pack;
743 
744         boolean dependsOnUnnamed = msym.requires != null &&
745                                    msym.requires.stream()
746                                                 .map(rd -> rd.module)
747                                                 .anyMatch(mod -> mod == unnamedModule);
748 
749         if (dependsOnUnnamed) {
750             //msyms depends on the unnamed module, for which we generally don't know
751             //the list of packages it "exports" ahead of time. So try to lookup the package in the
752             //current module, and in the unnamed module and see if it exists in one of them
753             PackageSymbol unnamedPack = getPackage(unnamedModule, flatName);
754 
755             if (unnamedPack != null && unnamedPack.exists()) {
756                 msym.visiblePackages.put(unnamedPack.fullname, unnamedPack);
757                 return unnamedPack;
758             }
759 
760             pack = enterPackage(msym, flatName);
761             pack.complete();
762             if (pack.exists())
763                 return pack;
764 
765             unnamedPack = enterPackage(unnamedModule, flatName);
766             unnamedPack.complete();
767             if (unnamedPack.exists()) {
768                 msym.visiblePackages.put(unnamedPack.fullname, unnamedPack);
769                 return unnamedPack;
770             }
771 
772             return pack;
773         }
774 
775         return enterPackage(msym, flatName);
776     }
777 
778     private static final Map<ModuleSymbol, ClassSymbol> EMPTY = new HashMap<>();
779 
780     public void removeClass(ModuleSymbol msym, Name flatName) {
781         classes.getOrDefault(flatName, EMPTY).remove(msym);
782     }
783 
784     public Iterable<ClassSymbol> getAllClasses() {
785         return () -> Iterators.createCompoundIterator(classes.values(), v -> v.values().iterator());
786     }
787 
788     private void doEnterClass(ModuleSymbol msym, ClassSymbol cs) {
789         classes.computeIfAbsent(cs.flatname, n -> new HashMap<>()).put(msym, cs);
790     }
791 
792     /** Create a new member or toplevel class symbol with given flat name
793      *  and enter in `classes' unless already there.
794      */
795     public ClassSymbol enterClass(ModuleSymbol msym, Name flatname) {
796         Assert.checkNonNull(msym);
797         PackageSymbol ps = lookupPackage(msym, Convert.packagePart(flatname));
798         Assert.checkNonNull(ps);
799         Assert.checkNonNull(ps.modle);
800         ClassSymbol c = getClass(ps.modle, flatname);
801         if (c == null) {
802             c = defineClass(Convert.shortName(flatname), ps);
803             doEnterClass(ps.modle, c);
804             return c;
805         } else
806             return c;
807     }
808 
809     /** Check to see if a package exists, given its fully qualified name.
810      */
811     public boolean packageExists(ModuleSymbol msym, Name fullname) {
812         Assert.checkNonNull(msym);
813         PackageSymbol pack = lookupPackage(msym, fullname, true);
814         return pack != null && pack.exists();
815     }
816 
817     /** Make a package, given its fully qualified name.
818      */
819     public PackageSymbol enterPackage(ModuleSymbol currModule, Name fullname) {
820         Assert.checkNonNull(currModule);
821         PackageSymbol p = getPackage(currModule, fullname);
822         if (p == null) {
823             Assert.check(!fullname.isEmpty(), () -> "rootPackage missing!; currModule: " + currModule);
824             p = new PackageSymbol(
825                     Convert.shortName(fullname),
826                     enterPackage(currModule, Convert.packagePart(fullname)));
827             p.completer = initialCompleter;
828             p.modle = currModule;
829             doEnterPackage(currModule, p);
830         }
831         return p;
832     }
833 
834     private void doEnterPackage(ModuleSymbol msym, PackageSymbol pack) {
835         packages.computeIfAbsent(pack.fullname, n -> new HashMap<>()).put(msym, pack);
836         msym.enclosedPackages = msym.enclosedPackages.prepend(pack);
837     }
838 
839     private void addRootPackageFor(ModuleSymbol module) {
840         doEnterPackage(module, rootPackage);
841         PackageSymbol unnamedPackage = new PackageSymbol(names.empty, rootPackage) {
842                 @Override
843                 public String toString() {
844                     return messages.getLocalizedString("compiler.misc.unnamed.package");
845                 }
846             };
847         unnamedPackage.modle = module;
848         //we cannot use a method reference below, as initialCompleter might be null now
849         unnamedPackage.completer = s -> initialCompleter.complete(s);
850         unnamedPackage.flags_field |= EXISTS;
851         module.unnamedPackage = unnamedPackage;
852     }
853 
854     public PackageSymbol getPackage(ModuleSymbol module, Name fullname) {
855         return packages.getOrDefault(fullname, Collections.emptyMap()).get(module);
856     }
857 
858     public ModuleSymbol enterModule(Name name) {
859         ModuleSymbol msym = modules.get(name);
860         if (msym == null) {
861             msym = ModuleSymbol.create(name, names.module_info);
862             addRootPackageFor(msym);
863             msym.completer = s -> moduleCompleter.complete(s); //bootstrap issues
864             modules.put(name, msym);
865         }
866         return msym;
867     }
868 
869     public ModuleSymbol getModule(Name name) {
870         return modules.get(name);
871     }
872 
873     //temporary:
874     public ModuleSymbol inferModule(Name packageName) {
875         if (packageName.isEmpty())
876             return java_base == noModule ? noModule : unnamedModule;//!
877 
878         ModuleSymbol msym = null;
879         Map<ModuleSymbol,PackageSymbol> map = packages.get(packageName);
880         if (map == null)
881             return null;
882         for (Map.Entry<ModuleSymbol,PackageSymbol> e: map.entrySet()) {
883             if (!e.getValue().members().isEmpty()) {
884                 if (msym == null) {
885                     msym = e.getKey();
886                 } else {
887                     return null;
888                 }
889             }
890         }
891         return msym;
892     }
893 
894     public List<ModuleSymbol> listPackageModules(Name packageName) {
895         if (packageName.isEmpty())
896             return List.nil();
897 
898         List<ModuleSymbol> result = List.nil();
899         Map<ModuleSymbol,PackageSymbol> map = packages.get(packageName);
900         if (map != null) {
901             for (Map.Entry<ModuleSymbol, PackageSymbol> e: map.entrySet()) {
902                 if (!e.getValue().members().isEmpty()) {
903                     result = result.prepend(e.getKey());
904                 }
905             }
906         }
907         return result;
908     }
909 
910     public Collection<ModuleSymbol> getAllModules() {
911         return modules.values();
912     }
913 
914     public Iterable<ClassSymbol> getClassesForName(Name candidate) {
915         return classes.getOrDefault(candidate, Collections.emptyMap()).values();
916     }
917 
918     public Iterable<PackageSymbol> getPackagesForName(Name candidate) {
919         return packages.getOrDefault(candidate, Collections.emptyMap()).values();
920     }
921 }