/*

  * 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.comp;

 import java.net.URI;

 import java.util.HashMap;

 import java.util.Map;

 import java.util.Optional;

 import javax.lang.model.element.ExecutableElement;

 import javax.lang.model.element.TypeElement;

 import javax.lang.model.element.VariableElement;

 import javax.lang.model.util.ElementScanner6;

 import javax.tools.JavaFileObject;

 import javax.tools.JavaFileManager;

 import com.sun.tools.javac.api.DuplicateClassChecker;

 import com.sun.tools.javac.code.*;

 import com.sun.tools.javac.code.Kinds.KindName;

 import com.sun.tools.javac.code.Kinds.KindSelector;

 import com.sun.tools.javac.code.Scope.*;

 import com.sun.tools.javac.code.Symbol.*;

 import com.sun.tools.javac.code.Type.*;

 import com.sun.tools.javac.main.Option.PkgInfo;

 import com.sun.tools.javac.model.LazyTreeLoader;

 import com.sun.tools.javac.resources.CompilerProperties.Errors;

 import com.sun.tools.javac.tree.*;

 import com.sun.tools.javac.tree.JCTree.*;

 import com.sun.tools.javac.util.*;

 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;

 import com.sun.tools.javac.util.List;

 import static com.sun.tools.javac.code.Flags.*;

 import static com.sun.tools.javac.code.Kinds.Kind.*;

 /** This class enters symbols for all encountered definitions into

  *  the symbol table. The pass consists of high-level two phases,

  *  organized as follows:

  *

  *  <p>In the first phase, all class symbols are entered into their

  *  enclosing scope, descending recursively down the tree for classes

  *  which are members of other classes. The class symbols are given a

  *  TypeEnter object as completer.

  *

  *  <p>In the second phase classes are completed using

  *  TypeEnter.complete(). Completion might occur on demand, but

  *  any classes that are not completed that way will be eventually

  *  completed by processing the `uncompleted' queue. Completion

  *  entails determination of a class's parameters, supertype and

  *  interfaces, as well as entering all symbols defined in the

  *  class into its scope, with the exception of class symbols which

  *  have been entered in phase 1.

  *

  *  <p>Whereas the first phase is organized as a sweep through all

  *  compiled syntax trees, the second phase is on-demand. Members of a

  *  class are entered when the contents of a class are first

  *  accessed. This is accomplished by installing completer objects in

  *  class symbols for compiled classes which invoke the type-enter

  *  phase for the corresponding class tree.

  *

  *  <p>Classes migrate from one phase to the next via queues:

  *

  *  <pre>{@literal

  *  class enter -> (Enter.uncompleted)         --> type enter

  *              -> (Todo)                      --> attribute

  *                                              (only for toplevel classes)

  *  }</pre>

  *

  *  <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 Enter extends JCTree.Visitor {

     protected static final Context.Key<Enter> enterKey = new Context.Key<>();

     Annotate annotate;

     Log log;

     Symtab syms;

     Check chk;

     TreeMaker make;

     TypeEnter typeEnter;

     Types types;

     Lint lint;

     Names names;

     JavaFileManager fileManager;

     PkgInfo pkginfoOpt;

     TypeEnvs typeEnvs;

     Modules modules;

     JCDiagnostic.Factory diags;

     private final LazyTreeLoader treeLoader;

     private final DuplicateClassChecker duplicateClassChecker;

     private final Source source;

     private final Todo todo;

     public static Enter instance(Context context) {

         Enter instance = context.get(enterKey);

         if (instance == null)

             instance = new Enter(context);

         return instance;

     }

     protected Enter(Context context) {

         context.put(enterKey, this);

         log = Log.instance(context);

         make = TreeMaker.instance(context);

         syms = Symtab.instance(context);

         chk = Check.instance(context);

         typeEnter = TypeEnter.instance(context);

         types = Types.instance(context);

         annotate = Annotate.instance(context);

         lint = Lint.instance(context);

         names = Names.instance(context);

         modules = Modules.instance(context);

         diags = JCDiagnostic.Factory.instance(context);

         treeLoader = LazyTreeLoader.instance(context);

         duplicateClassChecker = context.get(DuplicateClassChecker.class);

         predefClassDef = make.ClassDef(

             make.Modifiers(PUBLIC),

             syms.predefClass.name,

             List.nil(),

             null,

             List.nil(),

             List.nil());

         predefClassDef.sym = syms.predefClass;

         todo = Todo.instance(context);

         fileManager = context.get(JavaFileManager.class);

         Options options = Options.instance(context);

         pkginfoOpt = PkgInfo.get(options);

         typeEnvs = TypeEnvs.instance(context);

         source = Source.instance(context);

     }

     Map<TypeSymbol,Env<AttrContext>> typeEnvsShadow = null;

     private final Map<URI, JCCompilationUnit> compilationUnits =

             new HashMap<URI, JCCompilationUnit> ();

     public JCCompilationUnit getCompilationUnit (JavaFileObject fobj) {

         return this.compilationUnits.get(fobj.toUri());

     }

     /** Accessor for typeEnvs

      */

     public Env<AttrContext> getEnv(TypeSymbol sym) {

         return typeEnvs.get(sym);

     }

     public Iterable<Env<AttrContext>> getEnvs() {

         return typeEnvs.values();

     }

     public Env<AttrContext> getClassEnv(TypeSymbol sym) {

         Env<AttrContext> localEnv = getEnv(sym);

         if (localEnv == null) return null;

         Env<AttrContext> lintEnv = localEnv;

         while (lintEnv.info.lint == null)

             lintEnv = lintEnv.next;

         localEnv.info.lint = lintEnv.info.lint.augment(sym);

         return localEnv;

     }

     /** The queue of all classes that might still need to be completed;

      *  saved and initialized by main().

      */

     ListBuffer<ClassSymbol> uncompleted;

     /** The queue of modules whose imports still need to be checked. */

     ListBuffer<JCCompilationUnit> unfinishedModules = new ListBuffer<>();

     /** A dummy class to serve as enclClass for toplevel environments.

      */

     private JCClassDecl predefClassDef;

 /* ************************************************************************

  * environment construction

  *************************************************************************/

     /** Create a fresh environment for class bodies.

      *  This will create a fresh scope for local symbols of a class, referred

      *  to by the environments info.scope field.

      *  This scope will contain

      *    - symbols for this and super

      *    - symbols for any type parameters

      *  In addition, it serves as an anchor for scopes of methods and initializers

      *  which are nested in this scope via Scope.dup().

      *  This scope should not be confused with the members scope of a class.

      *

      *  @param tree     The class definition.

      *  @param env      The environment current outside of the class definition.

      */

     public Env<AttrContext> classEnv(JCClassDecl tree, Env<AttrContext> env) {

         Env<AttrContext> localEnv =

             env.dup(tree, env.info.dup(WriteableScope.create(tree.sym)));

         localEnv.enclClass = tree;

         localEnv.outer = env;

         localEnv.info.isSelfCall = false;

         localEnv.info.lint = null; // leave this to be filled in by Attr,

                                    // when annotations have been processed

         localEnv.info.isAnonymousDiamond = TreeInfo.isDiamond(env.tree);

         return localEnv;

     }

     /** Create a fresh environment for toplevels.

      *  @param tree     The toplevel tree.

      */

     Env<AttrContext> topLevelEnv(JCCompilationUnit tree) {

         Env<AttrContext> localEnv = new Env<>(tree, new AttrContext());

         localEnv.toplevel = tree;

         localEnv.enclClass = predefClassDef;

         tree.toplevelScope = WriteableScope.create(tree.packge);

         tree.namedImportScope = new NamedImportScope(tree.packge, tree.toplevelScope);

         tree.starImportScope = new StarImportScope(tree.packge);

         localEnv.info.scope = tree.toplevelScope;

         localEnv.info.lint = lint;

         return localEnv;

     }

     public Env<AttrContext> getTopLevelEnv(JCCompilationUnit tree) {

         Env<AttrContext> localEnv = new Env<>(tree, new AttrContext());

         localEnv.toplevel = tree;

         localEnv.enclClass = predefClassDef;

         localEnv.info.scope = tree.toplevelScope;

         localEnv.info.lint = lint;

         return localEnv;

     }

     /** The scope in which a member definition in environment env is to be entered

      *  This is usually the environment's scope, except for class environments,

      *  where the local scope is for type variables, and the this and super symbol

      *  only, and members go into the class member scope.

      */

     WriteableScope enterScope(Env<AttrContext> env) {

         return (env.tree.hasTag(JCTree.Tag.CLASSDEF))

             ? ((JCClassDecl) env.tree).sym.members_field

             : env.info.scope;

     }

     /** Create a fresh environment for modules.

      *

      *  @param tree     The module definition.

      *  @param env      The environment current outside of the module definition.

      */

     public Env<AttrContext> moduleEnv(JCModuleDecl tree, Env<AttrContext> env) {

         Assert.checkNonNull(tree.sym);

         Env<AttrContext> localEnv =

             env.dup(tree, env.info.dup(WriteableScope.create(tree.sym)));

         localEnv.enclClass = predefClassDef;

         localEnv.outer = env;

         localEnv.info.isSelfCall = false;

         localEnv.info.lint = null; // leave this to be filled in by Attr,

                                    // when annotations have been processed

         return localEnv;

     }

     public void shadowTypeEnvs(boolean b) {

         if (b) {

             assert typeEnvsShadow == null;

             typeEnvsShadow = new HashMap<TypeSymbol,Env<AttrContext>>();

         } else {

             for (Map.Entry<TypeSymbol, Env<AttrContext>> entry : typeEnvsShadow.entrySet()) {

                 if (entry.getValue() == null)

                     typeEnvs.remove(entry.getKey());

                 else

                     typeEnvs.put(entry.getKey(), entry.getValue());

             }

             typeEnvsShadow = null;

         }

     }

     public boolean isShadowed() {

         return typeEnvsShadow != null;

     }

 /* ************************************************************************

  * Visitor methods for phase 1: class enter

  *************************************************************************/

     /** Visitor argument: the current environment.

      */

     protected Env<AttrContext> env;

     /** Visitor result: the computed type.

      */

     Type result;

     /** Visitor method: enter all classes in given tree, catching any

      *  completion failure exceptions. Return the tree's type.

      *

      *  @param tree    The tree to be visited.

      *  @param env     The environment visitor argument.

      */

     Type classEnter(JCTree tree, Env<AttrContext> env) {

         Env<AttrContext> prevEnv = this.env;

         try {

             this.env = env;

             annotate.blockAnnotations();

             tree.accept(this);

             return result;

         }  catch (CompletionFailure ex) {

             return chk.completionError(tree.pos(), ex);

         } finally {

             annotate.unblockAnnotations();

             this.env = prevEnv;

         }

     }

     /** Visitor method: enter classes of a list of trees, returning a list of types.

      */

     <T extends JCTree> List<Type> classEnter(List<T> trees, Env<AttrContext> env) {

         ListBuffer<Type> ts = new ListBuffer<>();

         for (List<T> l = trees; l.nonEmpty(); l = l.tail) {

             Type t = classEnter(l.head, env);

             if (t != null)

                 ts.append(t);

         }

         return ts.toList();

     }

     @Override

     public void visitTopLevel(JCCompilationUnit tree) {

 //        Assert.checkNonNull(tree.modle, tree.sourcefile.toString());

         JavaFileObject prev = log.useSource(tree.sourcefile);

         boolean addEnv = false;

         boolean isPkgInfo = tree.sourcefile.isNameCompatible("package-info",

                                                              JavaFileObject.Kind.SOURCE);

         if (TreeInfo.isModuleInfo(tree)) {

             JCPackageDecl pd = tree.getPackage();

             if (pd != null) {

                 log.error(pd.pos(), Errors.NoPkgInModuleInfoJava);

             }

             tree.packge = syms.rootPackage;

             Env<AttrContext> topEnv = topLevelEnv(tree);

             if (tree.modle != syms.noModule) {

                 classEnter(tree.defs, topEnv);

                 tree.modle.usesProvidesCompleter = modules.getUsesProvidesCompleter();

             }

         } else {

             JCPackageDecl pd = tree.getPackage();

             if (pd != null) {

                 tree.packge = pd.packge = syms.enterPackage(tree.modle, TreeInfo.fullName(pd.pid));

                 PackageAttributer.attrib(pd.pid, tree.packge);

                 if (   pd.annotations.nonEmpty()

                     || pkginfoOpt == PkgInfo.ALWAYS

                     || tree.docComments != null) {

                     if (isPkgInfo) {

                         addEnv = true;

                     } else if (pd.annotations.nonEmpty()) {

                         log.error(pd.annotations.head.pos(),

                                   "pkg.annotations.sb.in.package-info.java");

                     }

                 }

             } else {

                 tree.packge = tree.modle.unnamedPackage;

             }

             Map<Name, PackageSymbol> visiblePackages = tree.modle.visiblePackages;

             Optional<ModuleSymbol> dependencyWithPackage =

                 syms.listPackageModules(tree.packge.fullname)

                     .stream()

                     .filter(m -> m != tree.modle)

                     .filter(cand -> visiblePackages != null && visiblePackages.get(tree.packge.fullname) == syms.getPackage(cand, tree.packge.fullname))

                     .findAny();

             if (dependencyWithPackage.isPresent()) {

                 log.error(pd, Errors.PackageInOtherModule(dependencyWithPackage.get()));

             }

             tree.packge.complete(); // Find all classes in package.

             Env<AttrContext> topEnv = topLevelEnv(tree);

             Env<AttrContext> packageEnv = isPkgInfo ? topEnv.dup(pd) : null;

             // Save environment of package-info.java file.

             if (isPkgInfo) {

                 Env<AttrContext> env0 = typeEnvs.get(tree.packge);

                 if (env0 != null) {

                     JCCompilationUnit tree0 = env0.toplevel;

                     if (!fileManager.isSameFile(tree.sourcefile, tree0.sourcefile)) {

                         log.warning(pd != null ? pd.pid.pos() : null,

                                     "pkg-info.already.seen",

                                     tree.packge);

                     }

                 }

                 typeEnvs.put(tree.packge, packageEnv);

                 for (Symbol q = tree.packge; q != null && q.kind == PCK; q = q.owner)

                     q.flags_field |= EXISTS;

                 Name name = names.package_info;

                 ClassSymbol c = syms.enterClass(tree.modle, name, tree.packge);

                 c.flatname = names.fromString(tree.packge + "." + name);

                 c.sourcefile = tree.sourcefile;

                 c.completer = Completer.NULL_COMPLETER;

                 c.members_field = WriteableScope.create(c);

                 tree.packge.package_info = c;

             }

             compilationUnits.put(tree.sourcefile.toUri(), tree);

             classEnter(tree.defs, topEnv);

             if (addEnv) {

                 if ((tree.packge.flags_field & APT_CLEANED) != 0)

                     todo.remove(tree.packge);

                 todo.append(packageEnv);

             }

         }

         log.useSource(prev);

         result = null;

     }

     private static class PackageAttributer extends TreeScanner {

         private Symbol pkg;

         public static void attrib(JCExpression pid, Symbol pkg) {

             PackageAttributer pa = new PackageAttributer();

             pa.pkg = pkg;

             pa.scan(pid);

         }

         @Override

         public void visitIdent(JCIdent that) {

             that.sym = pkg;

         }

         @Override

         public void visitSelect(JCFieldAccess that) {

             that.sym = pkg;

             pkg = pkg.owner;

             super.visitSelect(that);

         }

     }

     @Override

     public void visitClassDef(JCClassDecl tree) {

         Symbol owner = env.info.scope.owner;

         WriteableScope enclScope = enterScope(env);

         ClassSymbol c = null;

         boolean doEnterClass = true;

         boolean reattr=false, noctx=false;

         if (owner.kind == PCK) {

             // We are seeing a toplevel class.

             PackageSymbol packge = (PackageSymbol)owner;

             for (Symbol q = packge; q != null && q.kind == PCK; q = q.owner)

                 q.flags_field |= EXISTS;

             c = syms.enterClass(env.toplevel.modle, tree.name, packge);

             packge.members().enterIfAbsent(c);

             if ((tree.mods.flags & PUBLIC) != 0 && !classNameMatchesFileName(c, env)) {

                 KindName topElement = KindName.CLASS;

                 if ((tree.mods.flags & ENUM) != 0) {

                     topElement = KindName.ENUM;

                 } else if ((tree.mods.flags & INTERFACE) != 0) {

                     topElement = KindName.INTERFACE;

                 }

                 log.error(tree.pos(),

                           "class.public.should.be.in.file", topElement, tree.name);

             }

         } else {

             if ((enclScope.owner.flags_field & FROMCLASS) != 0) {

                 for (Symbol sym : enclScope.getSymbolsByName(tree.name)) {

                     if (sym.kind == TYP) {

                         c = (ClassSymbol)sym;

                         break;

                     }

                 }

                 if (c != null) {

                     if (chk.getCompiled(c) != null) {

                         c = null;

                     } else {

                         reattr = true;

                         if (owner.kind == TYP) {

                             if ((owner.flags_field & INTERFACE) != 0) {

                                 tree.mods.flags |= PUBLIC | STATIC;

                             }

                         }

                         doEnterClass = false;

                     }

                 } else if ((enclScope.owner.flags_field & APT_CLEANED) == 0) {

                     ClassSymbol cs = enclScope.owner.outermostClass();

                     treeLoader.couplingError(cs, tree);

                     doEnterClass = false;

                 }

             }

             if (c == null) {

                 if (!tree.name.isEmpty() &&

                         !chk.checkUniqueClassName(tree.pos(), tree.name, enclScope)) {

                     result = types.createErrorType(tree.name, owner, Type.noType);

                     tree.sym = (ClassSymbol)result.tsym;

                     Env<AttrContext> localEnv = classEnv(tree, env);

                     typeEnvs.put(tree.sym, localEnv);

                     tree.sym.completer = typeEnter;

                     ((ClassType)result).typarams_field = classEnter(tree.typarams, localEnv);

                     if (!tree.sym.isLocal() && uncompleted != null) uncompleted.append(tree.sym);

                     tree.type = tree.sym.type;

                     return;

                 }

                 if (owner.kind == TYP || owner.kind == ERR) {

                     // We are seeing a member class.

                     c = syms.enterClass(env.toplevel.modle, tree.name, (TypeSymbol)owner);

                     if (c.owner != owner) {

                         //anonymous class loaded from a classfile may be recreated from source (see below)

                         //if this class is a member of such an anonymous class, fix the owner:

                         Assert.check(owner.owner.kind != TYP && owner.owner.kind != ERR, owner::toString);

                         Symbol own = c.owner;

                         Assert.check(c.owner.kind == TYP || c.owner.kind == ERR, own::toString);

                         ClassSymbol cowner = (ClassSymbol) c.owner;

                         if (cowner.members_field != null) {

                             cowner.members_field.remove(c);

                         }

                         c.owner = owner;

                     }

                     if ((owner.flags_field & INTERFACE) != 0) {

                         tree.mods.flags |= PUBLIC | STATIC;

                     }

                     Symbol q = owner;

                     while(q != null && q.kind.matches(KindSelector.TYP)) {

                         q = q.owner;

                     }

                     if (q != null && q.kind != PCK && chk.getCompiled(c) != null) {

                         reattr = true;

                     }

                 } else {

                     // We are seeing a local class.

                     if (getIndex(tree) == -1) {

                         c = syms.defineClass(tree.name, owner);

                         c.flatname = chk.localClassName(c);

                         noctx = true;

                     }

                     else {

                         Name flatname = chk.localClassName(owner.enclClass(), tree.name, getIndex(tree));

                         if ((c=chk.getCompiled(env.toplevel.modle, flatname)) != null) {

                             reattr = true;

                         }

                         else {

                             c = syms.enterClass(env.toplevel.modle, flatname, tree.name, owner);

                             if (c.completer.isTerminal())

                                 reattr = true;

                         }

                     }

                     if (!c.name.isEmpty())

                         chk.checkTransparentClass(tree.pos(), c, env.info.scope);

                 }

             }

         }

         tree.sym = c;

         if (c.kind == ERR && c.type.isErroneous()) {

             c.flags_field &= ~FROMCLASS;

             c.kind = TYP;

             c.type = new ClassType(Type.noType, List.<Type>nil(), c);

         } else if (reattr && c.completer.isTerminal()) {

             new ElementScanner6<Void, Void>() {

                 @Override

                 public Void visitType(TypeElement te, Void p) {

                     if (te instanceof ClassSymbol && ((ClassSymbol) te).completer.isTerminal()) {

                         ((ClassSymbol) te).flags_field |= FROMCLASS;

                         for (Symbol sym : ((ClassSymbol) te).members().getSymbols()) {

                             try {

                                 if (sym != null && sym.owner == te)

                                     scan(sym);

                             } catch (CompletionFailure cf) {}

                         }

                     }

                     return null;

                 }

                 @Override

                 public Void visitExecutable(ExecutableElement ee, Void p) {

                     if (ee instanceof MethodSymbol)

                         ((MethodSymbol) ee).flags_field |= FROMCLASS;

                     return null;

                 }

                 @Override

                 public Void visitVariable(VariableElement ve, Void p) {

                     if (ve instanceof VarSymbol)

                         ((VarSymbol) ve).flags_field |= FROMCLASS;

                     return null;

                 }

             }.scan(c);

         }

         // Enter class into `compiled' table and enclosing scope.

         if (!reattr && !noctx && (chk.getCompiled(c) != null

                 || (!c.isLocal() && duplicateClassChecker != null && duplicateClassChecker.check(c.fullname, env.toplevel.getSourceFile())))) {

             duplicateClass(tree.pos(), c);

             result = types.createErrorType(tree.name, owner, Type.noType);

             tree.sym = c = (ClassSymbol)result.tsym;

         } else {

             chk.putCompiled(c);

         }

         if (doEnterClass) {

             enclScope.enter(c);

         }

         if (typeEnvsShadow != null) {

             Env<AttrContext> localEnv = typeEnvs.get(c);

             typeEnvsShadow.put(c, localEnv);

         }

         // Set up an environment for class block and store in `typeEnvs'

         // table, to be retrieved later in memberEnter and attribution.

         Env<AttrContext> localEnv = classEnv(tree, env);

         typeEnvs.put(c, localEnv);

         // Fill out class fields.

         boolean notYetCompleted = !c.completer.isTerminal();

         c.completer = Completer.NULL_COMPLETER; // do not allow the initial completer linger on.

         c.sourcefile = env.toplevel.sourcefile;

         if (notYetCompleted || (c.flags_field & FROMCLASS) == 0 && (enclScope.owner.flags_field & FROMCLASS) == 0) {

             c.flags_field = chk.checkFlags(tree.pos(), tree.mods.flags, c, tree);

             c.members_field = WriteableScope.create(c);

             ClassType ct = (ClassType)c.type;

             if (owner.kind != PCK && (c.flags_field & STATIC) == 0) {

                 // We are seeing a local or inner class.

                 // Set outer_field of this class to closest enclosing class

                 // which contains this class in a non-static context

                 // (its "enclosing instance class"), provided such a class exists.

                 Symbol owner1 = owner;

                 while (owner1.kind.matches(KindSelector.VAL_MTH) &&

                        (owner1.flags_field & STATIC) == 0) {

                     owner1 = owner1.owner;

                 }

                 if (owner1.kind == TYP) {

                     ct.setEnclosingType(owner1.type);

                 }

             }

             // Enter type parameters.

             ct.typarams_field = classEnter(tree.typarams, localEnv);

             ct.allparams_field = null;

         } else {

             c.flags_field = chk.checkFlags(tree.pos(), tree.mods.flags, c, tree) | (c.flags_field & (FROMCLASS | APT_CLEANED));

             ClassType ct = (ClassType)c.type;

             if (owner.kind != PCK && (c.flags_field & STATIC) == 0) {

                 // We are seeing a local or inner class.

                 // Set outer_field of this class to closest enclosing class

                 // which contains this class in a non-static context

                 // (its "enclosing instance class"), provided such a class exists.

                 Symbol owner1 = owner;

                 while (owner1.kind.matches(KindSelector.VAL_MTH) &&

                         (owner1.flags_field & STATIC) == 0) {

                     owner1 = owner1.owner;

                 }

                 if (owner1.kind == TYP) {

                     ct.setEnclosingType(owner1.type);

                 }

             }

             boolean wasNull = false;

             if (ct.typarams_field != null) {

                 for (List<Type> l = ct.typarams_field; l.nonEmpty(); l = l.tail)

                     localEnv.info.scope.enter(l.head.tsym);

             } else {

                 wasNull = true;

             }

             List<Type> classEnter = classEnter(tree.typarams, localEnv);

             if (wasNull) {

                 if (!classEnter.isEmpty()) {

                     //the symbol from class does not have any type parameters,

                     //but the symbol in the source code does:

                     ClassSymbol cs = env.info.scope.owner.outermostClass();

                     treeLoader.couplingError(cs, tree);

                 } else {

                     ct.typarams_field = List.nil();

                     ct.allparams_field = null;

                 }

             }

             if (c.members_field == null) {

                 c.members_field = WriteableScope.create(c);

                 c.flags_field &= ~FROMCLASS;

             }

             if (c.owner.kind.matches(KindSelector.VAL_MTH)) {

                 // local or anonymous class

                 for (Symbol ctor : c.members_field.getSymbolsByName(names.init)) {

                     c.members_field.remove(ctor);

                 }

             }

        }

         // install further completer for this type.

         c.completer = typeEnter;

         // Add non-local class to uncompleted, to make sure it will be

         // completed later.

         if (!c.isLocal() && uncompleted != null) uncompleted.append(c);

 //      System.err.println("entering " + c.fullname + " in " + c.owner);//DEBUG

         // Recursively enter all member classes.

         classEnter(tree.defs, localEnv);

         result = tree.type = c.type;

     }

     //where

         /** Does class have the same name as the file it appears in?

          */

         private static boolean classNameMatchesFileName(ClassSymbol c,

                                                         Env<AttrContext> env) {

             return env.toplevel.sourcefile.isNameCompatible(c.name.toString(),

                                                             JavaFileObject.Kind.SOURCE);

         }

     /** Complain about a duplicate class. */

     protected void duplicateClass(DiagnosticPosition pos, ClassSymbol c) {

         log.error(pos, "duplicate.class", c.fullname);

     }

     protected int getIndex(JCClassDecl clazz) {

         return -1;

     }

     /** Class enter visitor method for type parameters.

      *  Enter a symbol for type parameter in local scope, after checking that it

      *  is unique.

      */

     @Override

     public void visitTypeParameter(JCTypeParameter tree) {

         result = null;

         if ((env.info.scope.owner.flags_field & FROMCLASS) != 0) {

             for (Symbol sym : env.info.scope.getSymbolsByName(tree.name)) {

                 if (sym.kind == TYP) {

                     result = sym.type;

                     tree.type = result;

                     break;

                 }

             }

             if (result != null)

                 return;

             if ((env.info.scope.owner.flags_field & APT_CLEANED) == 0) {

                 ClassSymbol cs = env.info.scope.owner.outermostClass();

                 treeLoader.couplingError(cs, tree);

             }

         }

         TypeVar a = (tree.type != null)

         ? (TypeVar)tree.type

                 : new TypeVar(tree.name, env.info.scope.owner, syms.botType);

         tree.type = a;

         if (chk.checkUnique(tree.pos(), a.tsym, env.info.scope)) {

             env.info.scope.enter(a.tsym);

         }

         result = a;

     }

     @Override

     public void visitModuleDef(JCModuleDecl tree) {

         Env<AttrContext> moduleEnv = moduleEnv(tree, env);

         typeEnvs.put(tree.sym, moduleEnv);

         if (modules.isInModuleGraph(tree.sym)) {

             todo.append(moduleEnv);

         }

     }

     /** Default class enter visitor method: do nothing.

      */

     @Override

     public void visitTree(JCTree tree) {

         result = null;

     }

     /** Main method: enter all classes in a list of toplevel trees.

      *  @param trees      The list of trees to be processed.

      */

     public void main(List<JCCompilationUnit> trees) {

         complete(trees, null);

     }

     /** Main method: enter classes from the list of toplevel trees, possibly

      *  skipping TypeEnter for all but 'c' by placing them on the uncompleted

      *  list.

      *  @param trees      The list of trees to be processed.

      *  @param c          The class symbol to be processed or null to process all.

      */

     public void complete(List<JCCompilationUnit> trees, ClassSymbol c) {

         annotate.blockAnnotations();

         ListBuffer<ClassSymbol> prevUncompleted = uncompleted;

         if (typeEnter.completionEnabled) uncompleted = new ListBuffer<>();

         try {

             // enter all classes, and construct uncompleted list

             classEnter(trees, null);

             // complete all uncompleted classes in memberEnter

             if (typeEnter.completionEnabled) {

                 while (uncompleted.nonEmpty()) {

                     ClassSymbol clazz = uncompleted.next();

                     if (c == null || c == clazz || prevUncompleted == null)

                         clazz.complete();

                     else

                         // defer

                         prevUncompleted.append(clazz);

                 }

                 if (!modules.modulesInitialized()) {

                     for (JCCompilationUnit cut : trees) {

                         if (TreeInfo.isModuleInfo(cut)) {

                             unfinishedModules.append(cut);

                         } else {

                             typeEnter.ensureImportsChecked(List.of(cut));

                         }

                     }

                 } else {

                     typeEnter.ensureImportsChecked(unfinishedModules.toList());

                     unfinishedModules.clear();

                     typeEnter.ensureImportsChecked(trees);

                 }

             }

         } finally {

             uncompleted = prevUncompleted;

             annotate.unblockAnnotations();

         }

     }

     public void newRound() {

         typeEnvs.clear();

     }

 }