content: /*
   * Copyright (c) 1999, 2021, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package openjdk.tools.javac.code;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.EnumSet;
  import java.util.HashMap;
  import java.util.LinkedHashMap;
  import java.util.Map;
  
  import jdkx.lang.model.element.ElementVisitor;
  
  import openjdk.tools.javac.code.Scope.WriteableScope;
  import openjdk.tools.javac.code.Source.Feature;
  import openjdk.tools.javac.code.Symbol.ClassSymbol;
  import openjdk.tools.javac.code.Symbol.Completer;
  import openjdk.tools.javac.code.Symbol.CompletionFailure;
  import openjdk.tools.javac.code.Symbol.MethodSymbol;
  import openjdk.tools.javac.code.Symbol.ModuleSymbol;
  import openjdk.tools.javac.code.Symbol.PackageSymbol;
  import openjdk.tools.javac.code.Symbol.RootPackageSymbol;
  import openjdk.tools.javac.code.Symbol.TypeSymbol;
  import openjdk.tools.javac.code.Symbol.VarSymbol;
  import openjdk.tools.javac.code.Type.BottomType;
  import openjdk.tools.javac.code.Type.ClassType;
  import openjdk.tools.javac.code.Type.ErrorType;
  import openjdk.tools.javac.code.Type.JCPrimitiveType;
  import openjdk.tools.javac.code.Type.JCVoidType;
  import openjdk.tools.javac.code.Type.MethodType;
  import openjdk.tools.javac.code.Type.UnknownType;
  import openjdk.tools.javac.code.Types.UniqueType;
  import openjdk.tools.javac.comp.Modules;
  import openjdk.tools.javac.jvm.Target;
  import openjdk.tools.javac.util.Assert;
  import openjdk.tools.javac.util.Context;
  import openjdk.tools.javac.util.Convert;
  import openjdk.tools.javac.util.DefinedBy;
  import openjdk.tools.javac.util.DefinedBy.Api;
  import openjdk.tools.javac.util.Iterators;
  import openjdk.tools.javac.util.JavacMessages;
  import openjdk.tools.javac.util.List;
  import openjdk.tools.javac.util.Name;
  import openjdk.tools.javac.util.Names;
  
  import static openjdk.tools.javac.code.Flags.*;
  import static openjdk.tools.javac.code.Kinds.Kind.*;
  import static openjdk.tools.javac.code.TypeTag.*;
  
  /** A class that defines all predefined constants and operators
   *  as well as special classes such as java.lang.Object, which need
   *  to be known to the compiler. All symbols are held in instance
   *  fields. This makes it possible to work in multiple concurrent
   *  projects, which might use different class files for library classes.
   *
   *  <p><b>This is NOT part of any supported API.
   *  If you write code that depends on this, you do so at your own risk.
   *  This code and its internal interfaces are subject to change or
   *  deletion without notice.</b>
   */
  public class Symtab {
      /** The context key for the symbol table. */
      protected static final Context.Key<Symtab> symtabKey = new Context.Key<>();
  
      /** Get the symbol table instance. */
      public static Symtab instance(Context context) {
          Symtab instance = context.get(symtabKey);
          if (instance == null)
              instance = new Symtab(context);
          return instance;
      }
  
      /** Builtin types.
       */
      public final JCPrimitiveType byteType = new JCPrimitiveType(BYTE, null);
      public final JCPrimitiveType charType = new JCPrimitiveType(CHAR, null);
      public final JCPrimitiveType shortType = new JCPrimitiveType(SHORT, null);
      public final JCPrimitiveType intType = new JCPrimitiveType(INT, null);
      public final JCPrimitiveType longType = new JCPrimitiveType(LONG, null);
      public final JCPrimitiveType floatType = new JCPrimitiveType(FLOAT, null);
      public final JCPrimitiveType doubleType = new JCPrimitiveType(DOUBLE, null);
      public final JCPrimitiveType booleanType = new JCPrimitiveType(BOOLEAN, null);
      public final Type botType = new BottomType();
      public final JCVoidType voidType = new JCVoidType();
  
      private final Names names;
      private final JavacMessages messages;
      private final Completer initialCompleter;
      private final Completer moduleCompleter;
  
      /** A symbol for the unnamed module.
       */
      public final ModuleSymbol unnamedModule;
  
      /** The error module.
       */
      public final ModuleSymbol errModule;
  
      /** A symbol for no module, for use with -source 8 or less
       */
      public final ModuleSymbol noModule;
  
      /** A symbol for the root package.
       */
      public final PackageSymbol rootPackage;
  
      /** A symbol that stands for a missing symbol.
       */
      public final TypeSymbol noSymbol;
  
      /** The error symbol.
       */
      public final ClassSymbol errSymbol;
  
      /** The unknown symbol.
       */
      public final ClassSymbol unknownSymbol;
  
      /** A value for the errType, with a originalType of noType */
      public final Type errType;
  
      /** A value for the unknown type. */
      public final Type unknownType;
  
      /** The builtin type of all arrays. */
      public final ClassSymbol arrayClass;
      public final MethodSymbol arrayCloneMethod;
  
      /** VGJ: The (singleton) type of all bound types. */
      public final ClassSymbol boundClass;
  
      /** The builtin type of all methods. */
      public final ClassSymbol methodClass;
  
      /** A symbol for the java.base module.
       */
      public final ModuleSymbol java_base;
  
      /** Predefined types.
       */
      public final Type objectType;
      public final Type objectMethodsType;
      public final Type objectsType;
      public final Type classType;
      public final Type classLoaderType;
      public final Type stringType;
      public final Type stringBufferType;
      public final Type stringBuilderType;
      public final Type cloneableType;
      public final Type serializableType;
      public final Type serializedLambdaType;
      public final Type varHandleType;
      public final Type methodHandleType;
      public final Type methodHandleLookupType;
      public final Type methodTypeType;
      public final Type nativeHeaderType;
      public final Type throwableType;
      public final Type errorType;
      public final Type interruptedExceptionType;
      public final Type illegalArgumentExceptionType;
      public final Type exceptionType;
      public final Type runtimeExceptionType;
      public final Type classNotFoundExceptionType;
      public final Type noClassDefFoundErrorType;
      public final Type noSuchFieldErrorType;
      public final Type assertionErrorType;
      public final Type incompatibleClassChangeErrorType;
      public final Type cloneNotSupportedExceptionType;
      public final Type annotationType;
      public final TypeSymbol enumSym;
      public final Type listType;
      public final Type collectionsType;
      public final Type comparableType;
      public final Type comparatorType;
      public final Type arraysType;
      public final Type iterableType;
      public final Type iteratorType;
      public final Type annotationTargetType;
      public final Type overrideType;
      public final Type retentionType;
      public final Type deprecatedType;
      public final Type suppressWarningsType;
      public final Type supplierType;
      public final Type inheritedType;
      public final Type profileType;
      public final Type proprietaryType;
      public final Type systemType;
      public final Type autoCloseableType;
      public final Type trustMeType;
      public final Type lambdaMetafactory;
      public final Type stringConcatFactory;
      public final Type repeatableType;
      public final Type documentedType;
      public final Type elementTypeType;
      public final Type functionalInterfaceType;
      public final Type previewFeatureType;
      public final Type previewFeatureInternalType;
      public final Type typeDescriptorType;
      public final Type recordType;
      public final Type switchBootstrapsType;
      public final Type valueBasedType;
      public final Type valueBasedInternalType;
  
      /** The symbol representing the length field of an array.
       */
      public final VarSymbol lengthVar;
  
      /** The symbol representing the final finalize method on enums */
      public final MethodSymbol enumFinalFinalize;
  
      /** The symbol representing the close method on TWR AutoCloseable type */
      public final MethodSymbol autoCloseableClose;
  
      /** The predefined type that belongs to a tag.
       */
      public final Type[] typeOfTag = new Type[TypeTag.getTypeTagCount()];
  
      /** The name of the class that belongs to a basic type tag.
       */
      public final Name[] boxedName = new Name[TypeTag.getTypeTagCount()];
  
      /** A hashtable containing the encountered top-level and member classes,
       *  indexed by flat names. The table does not contain local classes.
       *  It should be updated from the outside to reflect classes defined
       *  by compiled source files.
       */
      private final Map<Name, Map<ModuleSymbol,ClassSymbol>> classes = new HashMap<>();
  
      /** A hashtable containing the encountered packages.
       *  the table should be updated from outside to reflect packages defined
       *  by compiled source files.
       */
      private final Map<Name, Map<ModuleSymbol,PackageSymbol>> packages = new HashMap<>();
  
      /** A hashtable giving the encountered modules.
       */
      private final Map<Name, ModuleSymbol> modules = new LinkedHashMap<>();
  
      private final Map<Types.UniqueType, VarSymbol> classFields = new HashMap<>();
  
      public VarSymbol getClassField(Type type, Types types) {
          return classFields.computeIfAbsent(
              new UniqueType(type, types), k -> {
                  Type arg = null;
                  if (type.getTag() == ARRAY || type.getTag() == CLASS)
                      arg = types.erasure(type);
                  else if (type.isPrimitiveOrVoid())
                      arg = types.boxedClass(type).type;
                  else
                      throw new AssertionError(type);
  
                  Type t = new ClassType(
                      classType.getEnclosingType(), List.of(arg), classType.tsym);
                  return new VarSymbol(
                      STATIC | PUBLIC | FINAL, names._class, t, type.tsym);
              });
      }
  
      public void initType(Type type, ClassSymbol c) {
          type.tsym = c;
          typeOfTag[type.getTag().ordinal()] = type;
      }
  
      public void initType(Type type, String name) {
          initType(
              type,
              new ClassSymbol(
                  PUBLIC, names.fromString(name), type, rootPackage));
      }
  
      public void initType(Type type, String name, String bname) {
          initType(type, name);
          boxedName[type.getTag().ordinal()] = names.fromString("java.lang." + bname);
      }
  
      /** The class symbol that owns all predefined symbols.
       */
      public final ClassSymbol predefClass;
  
      /** Enter a class into symbol table.
       *  @param s The name of the class.
       */
      private Type enterClass(String s) {
          return enterClass(java_base, names.fromString(s)).type;
      }
  
      public void synthesizeEmptyInterfaceIfMissing(final Type type) {
          final Completer completer = type.tsym.completer;
          type.tsym.completer = new Completer() {
              @Override
              public void complete(Symbol sym) throws CompletionFailure {
                  try {
                      completer.complete(sym);
                  } catch (CompletionFailure e) {
                      sym.flags_field |= (PUBLIC | INTERFACE);
                      ((ClassType) sym.type).supertype_field = objectType;
                  }
              }
  
              @Override
              public boolean isTerminal() {
                  return completer.isTerminal();
              }
          };
      }
  
      public void synthesizeBoxTypeIfMissing(final Type type) {
          ClassSymbol sym = enterClass(java_base, boxedName[type.getTag().ordinal()]);
          final Completer completer = sym.completer;
          sym.completer = new Completer() {
              @Override
              public void complete(Symbol sym) throws CompletionFailure {
                  try {
                      completer.complete(sym);
                  } catch (CompletionFailure e) {
                      sym.flags_field |= PUBLIC;
                      ((ClassType) sym.type).supertype_field = objectType;
                      MethodSymbol boxMethod =
                          new MethodSymbol(PUBLIC | STATIC, names.valueOf,
                                           new MethodType(List.of(type), sym.type,
                                  List.nil(), methodClass),
                              sym);
                      sym.members().enter(boxMethod);
                      MethodSymbol unboxMethod =
                          new MethodSymbol(PUBLIC,
                              type.tsym.name.append(names.Value), // x.intValue()
                              new MethodType(List.nil(), type,
                                  List.nil(), methodClass),
                              sym);
                      sym.members().enter(unboxMethod);
                  }
              }
  
              @Override
              public boolean isTerminal() {
                  return completer.isTerminal();
              }
          };
      }
  
      // Enter a synthetic class that is used to mark classes in ct.sym.
      // This class does not have a class file.
      private Type enterSyntheticAnnotation(String name) {
          // for now, leave the module null, to prevent problems from synthesizing the
          // existence of a class in any specific module, including noModule
          ClassType type = (ClassType)enterClass(java_base, names.fromString(name)).type;
          ClassSymbol sym = (ClassSymbol)type.tsym;
          sym.completer = Completer.NULL_COMPLETER;
          sym.flags_field = PUBLIC|ACYCLIC|ANNOTATION|INTERFACE;
          sym.erasure_field = type;
          sym.members_field = WriteableScope.create(sym);
          type.typarams_field = List.nil();
          type.allparams_field = List.nil();
          type.supertype_field = annotationType;
          type.interfaces_field = List.nil();
          return type;
      }
  
      /** Constructor; enters all predefined identifiers and operators
       *  into symbol table.
       */
      protected Symtab(Context context) throws CompletionFailure {
          context.put(symtabKey, this);
  
          names = Names.instance(context);
  
          // Create the unknown type
          unknownType = new UnknownType();
  
          messages = JavacMessages.instance(context);
  
          MissingInfoHandler missingInfoHandler = MissingInfoHandler.instance(context);
  
          Target target = Target.instance(context);
          rootPackage = new RootPackageSymbol(names.empty, null,
                                              missingInfoHandler,
                                              target.runtimeUseNestAccess());
  
          // create the basic builtin symbols
          unnamedModule = new ModuleSymbol(names.empty, null) {
                  {
                      directives = List.nil();
                      exports = List.nil();
                      provides = List.nil();
                      uses = List.nil();
                      ModuleSymbol java_base = enterModule(names.java_base);
                      openjdk.tools.javac.code.Directive.RequiresDirective d =
                              new openjdk.tools.javac.code.Directive.RequiresDirective(java_base,
                                      EnumSet.of(openjdk.tools.javac.code.Directive.RequiresFlag.MANDATED));
                      requires = List.of(d);
                  }
                  @Override
                  public String toString() {
                      return messages.getLocalizedString("compiler.misc.unnamed.module");
                  }
              };
          addRootPackageFor(unnamedModule);
          unnamedModule.enclosedPackages = unnamedModule.enclosedPackages.prepend(unnamedModule.unnamedPackage);
  
          errModule = new ModuleSymbol(names.empty, null) {
                  {
                      directives = List.nil();
                      exports = List.nil();
                      provides = List.nil();
                      uses = List.nil();
                      ModuleSymbol java_base = enterModule(names.java_base);
                      openjdk.tools.javac.code.Directive.RequiresDirective d =
                              new openjdk.tools.javac.code.Directive.RequiresDirective(java_base,
                                      EnumSet.of(openjdk.tools.javac.code.Directive.RequiresFlag.MANDATED));
                      requires = List.of(d);
                  }
              };
          addRootPackageFor(errModule);
  
          noModule = new ModuleSymbol(names.empty, null) {
              @Override public boolean isNoModule() {
                  return true;
              }
          };
          addRootPackageFor(noModule);
  
          noSymbol = new TypeSymbol(NIL, 0, names.empty, Type.noType, rootPackage) {
              @Override @DefinedBy(Api.LANGUAGE_MODEL)
              public <R, P> R accept(ElementVisitor<R, P> v, P p) {
                  return v.visitUnknown(this, p);
              }
              public boolean hasOuterInstance() {
                  return false;
              }
          };
  
          // create the error symbols
          errSymbol = new ClassSymbol(PUBLIC|STATIC|ACYCLIC, names.any, null, rootPackage);
          errType = new ErrorType(errSymbol, Type.noType);
  
          unknownSymbol = new ClassSymbol(PUBLIC|STATIC|ACYCLIC, names.fromString("<any?>"), null, rootPackage);
          unknownSymbol.members_field = new Scope.ErrorScope(unknownSymbol);
          unknownSymbol.type = unknownType;
  
          // initialize builtin types
          initType(byteType, "byte", "Byte");
          initType(shortType, "short", "Short");
          initType(charType, "char", "Character");
          initType(intType, "int", "Integer");
          initType(longType, "long", "Long");
          initType(floatType, "float", "Float");
          initType(doubleType, "double", "Double");
          initType(booleanType, "boolean", "Boolean");
          initType(voidType, "void", "Void");
          initType(botType, "<nulltype>");
          initType(errType, errSymbol);
          initType(unknownType, unknownSymbol);
  
          // the builtin class of all arrays
          arrayClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Array, noSymbol);
  
          // VGJ
          boundClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Bound, noSymbol);
          boundClass.members_field = new Scope.ErrorScope(boundClass);
  
          // the builtin class of all methods
          methodClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Method, noSymbol);
          methodClass.members_field = new Scope.ErrorScope(boundClass);
  
          // Create class to hold all predefined constants and operations.
          predefClass = new ClassSymbol(PUBLIC|ACYCLIC, names.empty, rootPackage);
          WriteableScope scope = WriteableScope.create(predefClass);
          predefClass.members_field = scope;
  
          // Get the initial completer for Symbols from the ClassFinder
          initialCompleter = ClassFinder.instance(context).getCompleter();
          rootPackage.members_field = WriteableScope.create(rootPackage);
  
          // Enter symbols for basic types.
          scope.enter(byteType.tsym);
          scope.enter(shortType.tsym);
          scope.enter(charType.tsym);
          scope.enter(intType.tsym);
          scope.enter(longType.tsym);
          scope.enter(floatType.tsym);
          scope.enter(doubleType.tsym);
          scope.enter(booleanType.tsym);
          scope.enter(errType.tsym);
  
          // Enter symbol for the errSymbol
          scope.enter(errSymbol);
  
          Source source = Source.instance(context);
          if (Feature.MODULES.allowedInSource(source)) {
              java_base = enterModule(names.java_base);
              //avoid completing java.base during the Symtab initialization
              java_base.completer = Completer.NULL_COMPLETER;
              java_base.visiblePackages = Collections.emptyMap();
          } else {
              java_base = noModule;
          }
  
          // Get the initial completer for ModuleSymbols from Modules
          moduleCompleter = Modules.instance(context).getCompleter();
  
          // Enter predefined classes. All are assumed to be in the java.base module.
          objectType = enterClass("java.lang.Object");
          objectMethodsType = enterClass("java.lang.runtime.ObjectMethods");
          objectsType = enterClass("java.util.Objects");
          classType = enterClass("java.lang.Class");
          stringType = enterClass("java.lang.String");
          stringBufferType = enterClass("java.lang.StringBuffer");
          stringBuilderType = enterClass("java.lang.StringBuilder");
          cloneableType = enterClass("java.lang.Cloneable");
          throwableType = enterClass("java.lang.Throwable");
          serializableType = enterClass("java.io.Serializable");
          serializedLambdaType = enterClass("java.lang.invoke.SerializedLambda");
          varHandleType = enterClass("java.lang.invoke.VarHandle");
          methodHandleType = enterClass("java.lang.invoke.MethodHandle");
          methodHandleLookupType = enterClass("java.lang.invoke.MethodHandles$Lookup");
          methodTypeType = enterClass("java.lang.invoke.MethodType");
          errorType = enterClass("java.lang.Error");
          illegalArgumentExceptionType = enterClass("java.lang.IllegalArgumentException");
          interruptedExceptionType = enterClass("java.lang.InterruptedException");
          exceptionType = enterClass("java.lang.Exception");
          runtimeExceptionType = enterClass("java.lang.RuntimeException");
          classNotFoundExceptionType = enterClass("java.lang.ClassNotFoundException");
          noClassDefFoundErrorType = enterClass("java.lang.NoClassDefFoundError");
          noSuchFieldErrorType = enterClass("java.lang.NoSuchFieldError");
          assertionErrorType = enterClass("java.lang.AssertionError");
          incompatibleClassChangeErrorType = enterClass("java.lang.IncompatibleClassChangeError");
          cloneNotSupportedExceptionType = enterClass("java.lang.CloneNotSupportedException");
          annotationType = enterClass("java.lang.annotation.Annotation");
          classLoaderType = enterClass("java.lang.ClassLoader");
          enumSym = enterClass(java_base, names.java_lang_Enum);
          enumFinalFinalize =
              new MethodSymbol(PROTECTED|FINAL|HYPOTHETICAL,
                               names.finalize,
                               new MethodType(List.nil(), voidType,
                                              List.nil(), methodClass),
                               enumSym);
          listType = enterClass("java.util.List");
          collectionsType = enterClass("java.util.Collections");
          comparableType = enterClass("java.lang.Comparable");
          comparatorType = enterClass("java.util.Comparator");
          arraysType = enterClass("java.util.Arrays");
          iterableType = enterClass("java.lang.Iterable");
          iteratorType = enterClass("java.util.Iterator");
          annotationTargetType = enterClass("java.lang.annotation.Target");
          overrideType = enterClass("java.lang.Override");
          retentionType = enterClass("java.lang.annotation.Retention");
          deprecatedType = enterClass("java.lang.Deprecated");
          suppressWarningsType = enterClass("java.lang.SuppressWarnings");
          supplierType = enterClass("java.util.function.Supplier");
          inheritedType = enterClass("java.lang.annotation.Inherited");
          repeatableType = enterClass("java.lang.annotation.Repeatable");
          documentedType = enterClass("java.lang.annotation.Documented");
          elementTypeType = enterClass("java.lang.annotation.ElementType");
          systemType = enterClass("java.lang.System");
          autoCloseableType = enterClass("java.lang.AutoCloseable");
          autoCloseableClose = new MethodSymbol(PUBLIC,
                               names.close,
                               new MethodType(List.nil(), voidType,
                                              List.of(exceptionType), methodClass),
                               autoCloseableType.tsym);
          trustMeType = enterClass("java.lang.SafeVarargs");
          nativeHeaderType = enterClass("java.lang.annotation.Native");
          lambdaMetafactory = enterClass("java.lang.invoke.LambdaMetafactory");
          stringConcatFactory = enterClass("java.lang.invoke.StringConcatFactory");
          functionalInterfaceType = enterClass("java.lang.FunctionalInterface");
          previewFeatureType = enterClass("jdk.internal.javac.PreviewFeature");
          previewFeatureInternalType = enterSyntheticAnnotation("jdk.internal.PreviewFeature+Annotation");
          typeDescriptorType = enterClass("java.lang.invoke.TypeDescriptor");
          recordType = enterClass("java.lang.Record");
          switchBootstrapsType = enterClass("java.lang.runtime.SwitchBootstraps");
          valueBasedType = enterClass("jdk.internal.ValueBased");
          valueBasedInternalType = enterSyntheticAnnotation("jdk.internal.ValueBased+Annotation");
  
          synthesizeEmptyInterfaceIfMissing(autoCloseableType);
          synthesizeEmptyInterfaceIfMissing(cloneableType);
          synthesizeEmptyInterfaceIfMissing(serializableType);
          synthesizeEmptyInterfaceIfMissing(lambdaMetafactory);
          synthesizeEmptyInterfaceIfMissing(serializedLambdaType);
          synthesizeEmptyInterfaceIfMissing(stringConcatFactory);
          synthesizeBoxTypeIfMissing(doubleType);
          synthesizeBoxTypeIfMissing(floatType);
          synthesizeBoxTypeIfMissing(voidType);
  
          // Enter a synthetic class that is used to mark internal
          // proprietary classes in ct.sym.  This class does not have a
          // class file.
          proprietaryType = enterSyntheticAnnotation("sun.Proprietary+Annotation");
  
          // Enter a synthetic class that is used to provide profile info for
          // classes in ct.sym.  This class does not have a class file.
          profileType = enterSyntheticAnnotation("jdk.Profile+Annotation");
          MethodSymbol m = new MethodSymbol(PUBLIC | ABSTRACT, names.value, intType, profileType.tsym);
          profileType.tsym.members().enter(m);
  
          // Enter a class for arrays.
          // The class implements java.lang.Cloneable and java.io.Serializable.
          // It has a final length field and a clone method.
          ClassType arrayClassType = (ClassType)arrayClass.type;
          arrayClassType.supertype_field = objectType;
          arrayClassType.interfaces_field = List.of(cloneableType, serializableType);
          arrayClass.members_field = WriteableScope.create(arrayClass);
          lengthVar = new VarSymbol(
              PUBLIC | FINAL,
              names.length,
              intType,
              arrayClass);
          arrayClass.members().enter(lengthVar);
          arrayCloneMethod = new MethodSymbol(
              PUBLIC,
              names.clone,
              new MethodType(List.nil(), objectType,
                             List.nil(), methodClass),
              arrayClass);
          arrayClass.members().enter(arrayCloneMethod);
  
          if (java_base != noModule)
              java_base.completer = moduleCompleter::complete; //bootstrap issues
  
      }
  
      /** Define a new class given its name and owner.
       */
      public ClassSymbol defineClass(Name name, Symbol owner) {
          ClassSymbol c = new ClassSymbol(0, name, owner);
          c.completer = initialCompleter;
          return c;
      }
  
      /** Create a new toplevel or member class symbol with given name
       *  and owner and enter in `classes' unless already there.
       */
      public ClassSymbol enterClass(ModuleSymbol msym, Name name, TypeSymbol owner) {
          Assert.checkNonNull(msym);
          Name flatname = TypeSymbol.formFlatName(name, owner);
          ClassSymbol c = getClass(msym, flatname);
          if (c == null) {
              c = defineClass(name, owner);
              doEnterClass(msym, c);
          } else if ((c.name != name || c.owner != owner) && owner.kind == TYP && c.owner.kind == PCK) {
              // reassign fields of classes that might have been loaded with
              // their flat names.
              c.owner.members().remove(c);
              c.name = name;
              c.owner = owner;
              c.fullname = ClassSymbol.formFullName(name, owner);
          }
          return c;
      }
  
      public ClassSymbol enterClass(ModuleSymbol msym, Name flatname, Name name, Symbol owner) {
          Assert.checkNonNull(msym);
          ClassSymbol c = getClass(msym, flatname);
          if (c == null) {
              c = defineClass(name, owner);
              c.flatname = flatname;
              doEnterClass(msym, c);
          } else if ((c.name != name || c.owner != owner) && c.owner.kind.matches(Kinds.KindSelector.TYP_PCK)) {
              // reassign fields of classes that might have been loaded with
              // their flat names.
              c.owner.members().remove(c);
              c.name = name;
              c.owner = owner;
              c.fullname = ClassSymbol.formFullName(name, owner);
              if (c.type != null && c.type.hasTag(CLASS)) {
                  ((ClassType)c.type).setEnclosingType(Type.noType);
              }
          }
          return c;
      }
  
      public ClassSymbol getClass(ModuleSymbol msym, Name flatName) {
          Assert.checkNonNull(msym, flatName::toString);
          return classes.getOrDefault(flatName, Collections.emptyMap()).get(msym);
      }
  
      public PackageSymbol lookupPackage(ModuleSymbol msym, Name flatName) {
          return lookupPackage(msym, flatName, false);
      }
  
      private PackageSymbol lookupPackage(ModuleSymbol msym, Name flatName, boolean onlyExisting) {
          Assert.checkNonNull(msym);
  
          if (flatName.isEmpty()) {
              //unnamed packages only from the current module - visiblePackages contains *root* package, not unnamed package!
              return msym.unnamedPackage;
          }
  
          if (msym == noModule) {
              return enterPackage(msym, flatName);
          }
  
          msym.complete();
  
          PackageSymbol pack;
  
          pack = msym.visiblePackages.get(flatName);
  
          if (pack != null)
              return pack;
  
          pack = getPackage(msym, flatName);
  
          if ((pack != null && pack.exists()) || onlyExisting)
              return pack;
  
          boolean dependsOnUnnamed = msym.requires != null &&
                                     msym.requires.stream()
                                                  .map(rd -> rd.module)
                                                  .anyMatch(mod -> mod == unnamedModule);
  
          if (dependsOnUnnamed) {
              //msyms depends on the unnamed module, for which we generally don't know
              //the list of packages it "exports" ahead of time. So try to lookup the package in the
              //current module, and in the unnamed module and see if it exists in one of them
              PackageSymbol unnamedPack = getPackage(unnamedModule, flatName);
  
              if (unnamedPack != null && unnamedPack.exists()) {
                  msym.visiblePackages.put(unnamedPack.fullname, unnamedPack);
                  return unnamedPack;
              }
  
              pack = enterPackage(msym, flatName);
              pack.complete();
              if (pack.exists())
                  return pack;
  
              unnamedPack = enterPackage(unnamedModule, flatName);
              unnamedPack.complete();
              if (unnamedPack.exists()) {
                  msym.visiblePackages.put(unnamedPack.fullname, unnamedPack);
                  return unnamedPack;
              }
  
              return pack;
          }
  
          return enterPackage(msym, flatName);
      }
  
      private static final Map<ModuleSymbol, ClassSymbol> EMPTY = new HashMap<>();
  
      public void removeClass(ModuleSymbol msym, Name flatName) {
          classes.getOrDefault(flatName, EMPTY).remove(msym);
      }
  
      public Iterable<ClassSymbol> getAllClasses() {
          return () -> Iterators.createCompoundIterator(classes.values(), v -> v.values().iterator());
      }
  
      private void doEnterClass(ModuleSymbol msym, ClassSymbol cs) {
          classes.computeIfAbsent(cs.flatname, n -> new HashMap<>()).put(msym, cs);
      }
  
      /** Create a new member or toplevel class symbol with given flat name
       *  and enter in `classes' unless already there.
       */
      public ClassSymbol enterClass(ModuleSymbol msym, Name flatname) {
          Assert.checkNonNull(msym);
          if (flatname == null)
              flatname = names.empty;
          PackageSymbol ps = lookupPackage(msym, Convert.packagePart(flatname));
          Assert.checkNonNull(ps);
          Assert.checkNonNull(ps.modle);
          ClassSymbol c = getClass(ps.modle, flatname);
          if (c == null) {
              c = defineClass(Convert.shortName(flatname), ps);
              doEnterClass(ps.modle, c);
              return c;
          } else
              return c;
      }
  
      /** Check to see if a package exists, given its fully qualified name.
       */
      public boolean packageExists(ModuleSymbol msym, Name fullname) {
          Assert.checkNonNull(msym);
          PackageSymbol pack = lookupPackage(msym, fullname, true);
          return pack != null && pack.exists();
      }
  
      /** Make a package, given its fully qualified name.
       */
      public PackageSymbol enterPackage(ModuleSymbol currModule, Name fullname) {
          Assert.checkNonNull(currModule);
          PackageSymbol p = getPackage(currModule, fullname);
          if (p == null) {
              Assert.check(!fullname.isEmpty(), () -> "rootPackage missing!; currModule: " + currModule);
              p = new PackageSymbol(
                      Convert.shortName(fullname),
                      enterPackage(currModule, Convert.packagePart(fullname)));
              p.completer = initialCompleter;
              p.modle = currModule;
              doEnterPackage(currModule, p);
          }
          return p;
      }
  
      private void doEnterPackage(ModuleSymbol msym, PackageSymbol pack) {
          packages.computeIfAbsent(pack.fullname, n -> new HashMap<>()).put(msym, pack);
          msym.enclosedPackages = msym.enclosedPackages.prepend(pack);
      }
  
      private void addRootPackageFor(ModuleSymbol module) {
          doEnterPackage(module, rootPackage);
          PackageSymbol unnamedPackage = new PackageSymbol(names.empty, rootPackage) {
                  @Override
                  public String toString() {
                      return messages.getLocalizedString("compiler.misc.unnamed.package");
                  }
              };
          unnamedPackage.modle = module;
          //we cannot use a method reference below, as initialCompleter might be null now
          unnamedPackage.completer = s -> initialCompleter.complete(s);
          unnamedPackage.flags_field |= EXISTS;
          module.unnamedPackage = unnamedPackage;
      }
  
      public PackageSymbol getPackage(ModuleSymbol module, Name fullname) {
          return packages.getOrDefault(fullname, Collections.emptyMap()).get(module);
      }
  
      public ModuleSymbol enterModule(Name name) {
          ModuleSymbol msym = modules.get(name);
          if (msym == null) {
              msym = ModuleSymbol.create(name, names.module_info);
              addRootPackageFor(msym);
              msym.completer = s -> moduleCompleter.complete(s); //bootstrap issues
              modules.put(name, msym);
          }
          return msym;
      }
  
      public ModuleSymbol getModule(Name name) {
          return modules.get(name);
      }
  
      //temporary:
      public ModuleSymbol inferModule(Name packageName) {
          if (packageName.isEmpty())
              return java_base == noModule ? noModule : unnamedModule;//!
  
          ModuleSymbol msym = null;
          Map<ModuleSymbol,PackageSymbol> map = packages.get(packageName);
          if (map == null)
              return null;
          for (Map.Entry<ModuleSymbol,PackageSymbol> e: map.entrySet()) {
              if (!e.getValue().members().isEmpty()) {
                  if (msym == null) {
                      msym = e.getKey();
                  } else {
                      return null;
                  }
              }
          }
          return msym;
      }
  
      public List<ModuleSymbol> listPackageModules(Name packageName) {
          if (packageName.isEmpty())
              return List.nil();
  
          List<ModuleSymbol> result = List.nil();
          Map<ModuleSymbol,PackageSymbol> map = packages.get(packageName);
          if (map != null) {
              for (Map.Entry<ModuleSymbol, PackageSymbol> e: map.entrySet()) {
                  if (!e.getValue().members().isEmpty()) {
                      result = result.prepend(e.getKey());
                  }
              }
          }
          return result;
      }
  
      public Collection<ModuleSymbol> getAllModules() {
          return modules.values();
      }
  
      public Iterable<ClassSymbol> getClassesForName(Name candidate) {
          return classes.getOrDefault(candidate, Collections.emptyMap()).values();
      }
  
      public Iterable<PackageSymbol> getPackagesForName(Name candidate) {
          return packages.getOrDefault(candidate, Collections.emptyMap()).values();
      }
  }
  