src/jdk.compiler/share/classes/com/sun/tools/javac/code/Symtab.java
changeset 47216 71c04702a3d5
parent 43272 421ae1e38d2d
child 48054 702043a4cdeb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Symtab.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,829 @@
+/*
+ * Copyright (c) 1999, 2017, 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 com.sun.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 javax.lang.model.element.ElementVisitor;
+
+import com.sun.tools.javac.code.Scope.WriteableScope;
+import com.sun.tools.javac.code.Symbol.ClassSymbol;
+import com.sun.tools.javac.code.Symbol.Completer;
+import com.sun.tools.javac.code.Symbol.CompletionFailure;
+import com.sun.tools.javac.code.Symbol.MethodSymbol;
+import com.sun.tools.javac.code.Symbol.ModuleSymbol;
+import com.sun.tools.javac.code.Symbol.PackageSymbol;
+import com.sun.tools.javac.code.Symbol.TypeSymbol;
+import com.sun.tools.javac.code.Symbol.VarSymbol;
+import com.sun.tools.javac.code.Type.BottomType;
+import com.sun.tools.javac.code.Type.ClassType;
+import com.sun.tools.javac.code.Type.ErrorType;
+import com.sun.tools.javac.code.Type.JCPrimitiveType;
+import com.sun.tools.javac.code.Type.JCVoidType;
+import com.sun.tools.javac.code.Type.MethodType;
+import com.sun.tools.javac.code.Type.UnknownType;
+import com.sun.tools.javac.comp.Modules;
+import com.sun.tools.javac.util.Assert;
+import com.sun.tools.javac.util.Context;
+import com.sun.tools.javac.util.Convert;
+import com.sun.tools.javac.util.DefinedBy;
+import com.sun.tools.javac.util.DefinedBy.Api;
+import com.sun.tools.javac.util.Iterators;
+import com.sun.tools.javac.util.JavacMessages;
+import com.sun.tools.javac.util.List;
+import com.sun.tools.javac.util.Name;
+import com.sun.tools.javac.util.Names;
+
+import static com.sun.tools.javac.code.Flags.*;
+import static com.sun.tools.javac.code.Kinds.Kind.*;
+import static com.sun.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 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 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;
+
+    /** 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<>();
+
+    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);
+
+        rootPackage = new PackageSymbol(names.empty, null);
+
+        // 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);
+                    com.sun.tools.javac.code.Directive.RequiresDirective d =
+                            new com.sun.tools.javac.code.Directive.RequiresDirective(java_base,
+                                    EnumSet.of(com.sun.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);
+                    com.sun.tools.javac.code.Directive.RequiresDirective d =
+                            new com.sun.tools.javac.code.Directive.RequiresDirective(java_base,
+                                    EnumSet.of(com.sun.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);
+            }
+        };
+
+        // 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 (source.allowModules()) {
+            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");
+        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");
+        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");
+
+        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 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) {
+        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())
+            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);
+        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);
+        return lookupPackage(msym, fullname).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);
+        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();
+    }
+}