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.comp;
  
  import java.util.*;
  import java.util.function.BiConsumer;
  
  import jdkx.lang.model.element.ElementKind;
  import jdkx.tools.JavaFileObject;
  
  import openjdk.source.tree.CaseTree;
  import openjdk.source.tree.IdentifierTree;
  import openjdk.source.tree.MemberReferenceTree.ReferenceMode;
  import openjdk.source.tree.MemberSelectTree;
  import openjdk.source.tree.TreeVisitor;
  import openjdk.source.util.SimpleTreeVisitor;
  import openjdk.tools.javac.code.*;
  import openjdk.tools.javac.code.Lint.LintCategory;
  import openjdk.tools.javac.code.Scope.WriteableScope;
  import openjdk.tools.javac.code.Source.Feature;
  import openjdk.tools.javac.code.Symbol.*;
  import openjdk.tools.javac.code.Type.*;
  import openjdk.tools.javac.code.TypeMetadata.Annotations;
  import openjdk.tools.javac.code.Types.FunctionDescriptorLookupError;
  import openjdk.tools.javac.comp.ArgumentAttr.LocalCacheContext;
  import openjdk.tools.javac.comp.Check.CheckContext;
  import openjdk.tools.javac.comp.DeferredAttr.AttrMode;
  import openjdk.tools.javac.comp.MatchBindingsComputer.MatchBindings;
  import openjdk.tools.javac.jvm.*;
  import static openjdk.tools.javac.resources.CompilerProperties.Fragments.Diamond;
  import static openjdk.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArg;
  import static openjdk.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArgs;
  import openjdk.tools.javac.resources.CompilerProperties.Errors;
  import openjdk.tools.javac.resources.CompilerProperties.Fragments;
  import openjdk.tools.javac.resources.CompilerProperties.Warnings;
  import openjdk.tools.javac.tree.*;
  import openjdk.tools.javac.tree.JCTree.*;
  import openjdk.tools.javac.tree.JCTree.JCPolyExpression.*;
  import openjdk.tools.javac.util.*;
  import openjdk.tools.javac.util.DefinedBy.Api;
  import openjdk.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  import openjdk.tools.javac.util.JCDiagnostic.Error;
  import openjdk.tools.javac.util.JCDiagnostic.Fragment;
  import openjdk.tools.javac.util.JCDiagnostic.Warning;
  import openjdk.tools.javac.util.List;
  
  import static openjdk.tools.javac.code.Flags.*;
  import static openjdk.tools.javac.code.Flags.ANNOTATION;
  import static openjdk.tools.javac.code.Flags.BLOCK;
  import static openjdk.tools.javac.code.Kinds.*;
  import static openjdk.tools.javac.code.Kinds.Kind.*;
  import static openjdk.tools.javac.code.TypeTag.*;
  import static openjdk.tools.javac.code.TypeTag.WILDCARD;
  import static openjdk.tools.javac.tree.JCTree.Tag.*;
  import openjdk.tools.javac.util.JCDiagnostic.DiagnosticFlag;
  
  /** This is the main context-dependent analysis phase in GJC. It
   *  encompasses name resolution, type checking and constant folding as
   *  subtasks. Some subtasks involve auxiliary classes.
   *  @see Check
   *  @see Resolve
   *  @see ConstFold
   *  @see Infer
   *
   *  <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 Attr extends JCTree.Visitor {
      protected static final Context.Key<Attr> attrKey = new Context.Key<>();
  
      final Names names;
      final Log log;
      final Symtab syms;
      final Resolve rs;
      final Operators operators;
      final Infer infer;
      final Analyzer analyzer;
      final DeferredAttr deferredAttr;
      final Check chk;
      final Flow flow;
      final MemberEnter memberEnter;
      final TypeEnter typeEnter;
      final TreeMaker make;
      final ConstFold cfolder;
      final Enter enter;
      final Target target;
      final Types types;
      final Preview preview;
      final JCDiagnostic.Factory diags;
      final TypeAnnotations typeAnnotations;
      final DeferredLintHandler deferredLintHandler;
      final TypeEnvs typeEnvs;
      final Dependencies dependencies;
      final Annotate annotate;
      final ArgumentAttr argumentAttr;
      private final boolean isBackgroundCompilation;
  	
      final MatchBindingsComputer matchBindingsComputer;
      final AttrRecover attrRecover;
  
      public static Attr instance(Context context) {
          Attr instance = context.get(attrKey);
          if (instance == null)
              instance = new Attr(context);
          return instance;
      }
  
      protected Attr(Context context) {
          context.put(attrKey, this);
  
          names = Names.instance(context);
          log = Log.instance(context);
          syms = Symtab.instance(context);
          rs = Resolve.instance(context);
          operators = Operators.instance(context);
          chk = Check.instance(context);
          flow = Flow.instance(context);
          memberEnter = MemberEnter.instance(context);
          typeEnter = TypeEnter.instance(context);
          make = TreeMaker.instance(context);
          enter = Enter.instance(context);
          infer = Infer.instance(context);
          analyzer = Analyzer.instance(context);
          deferredAttr = DeferredAttr.instance(context);
          cfolder = ConstFold.instance(context);
          target = Target.instance(context);
          types = Types.instance(context);
          preview = Preview.instance(context);
          diags = JCDiagnostic.Factory.instance(context);
          annotate = Annotate.instance(context);
          typeAnnotations = TypeAnnotations.instance(context);
          deferredLintHandler = DeferredLintHandler.instance(context);
          typeEnvs = TypeEnvs.instance(context);
          dependencies = Dependencies.instance(context);
          argumentAttr = ArgumentAttr.instance(context);
          matchBindingsComputer = MatchBindingsComputer.instance(context);
          attrRecover = AttrRecover.instance(context);
  
          Options options = Options.instance(context);
  
          Source source = Source.instance(context);
          allowPoly = Feature.POLY.allowedInSource(source);
          allowTypeAnnos = Feature.TYPE_ANNOTATIONS.allowedInSource(source);
          allowLambda = Feature.LAMBDA.allowedInSource(source);
          allowDefaultMethods = Feature.DEFAULT_METHODS.allowedInSource(source);
          allowStaticInterfaceMethods = Feature.STATIC_INTERFACE_METHODS.allowedInSource(source);
          allowReifiableTypesInInstanceof = Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source);
          allowRecords = Feature.RECORDS.allowedInSource(source);
          allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
                               Feature.PATTERN_SWITCH.allowedInSource(source);
          sourceName = source.name;
          useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
  
          statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
          varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
          unknownExprInfo = new ResultInfo(KindSelector.VAL, Type.noType);
          methodAttrInfo = new MethodAttrInfo();
          unknownTypeInfo = new ResultInfo(KindSelector.TYP, Type.noType);
          unknownTypeExprInfo = new ResultInfo(KindSelector.VAL_TYP, Type.noType);
          recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
  
          isBackgroundCompilation = options.get("backgroundCompilation") != null;     //NOI18N
      }
  
      /** Switch: support target-typing inference
       */
      boolean allowPoly;
  
      /** Switch: support type annotations.
       */
      boolean allowTypeAnnos;
  
      /** Switch: support lambda expressions ?
       */
      boolean allowLambda;
  
      /** Switch: support default methods ?
       */
      boolean allowDefaultMethods;
  
      /** Switch: static interface methods enabled?
       */
      boolean allowStaticInterfaceMethods;
  
      /** Switch: reifiable types in instanceof enabled?
       */
      boolean allowReifiableTypesInInstanceof;
  
      /** Are records allowed
       */
      private final boolean allowRecords;
  
      /** Are patterns in switch allowed
       */
      private final boolean allowPatternSwitch;
  
      /**
       * Switch: warn about use of variable before declaration?
       * RFE: 6425594
       */
      boolean useBeforeDeclarationWarning;
  
      /**
       * Switch: name of source level; used for error reporting.
       */
      String sourceName;
  
      /** Check kind and type of given tree against protokind and prototype.
       *  If check succeeds, store type in tree and return it.
       *  If check fails, store errType in tree and return it.
       *  No checks are performed if the prototype is a method type.
       *  It is not necessary in this case since we know that kind and type
       *  are correct.
       *
       *  @param tree     The tree whose kind and type is checked
       *  @param found    The computed type of the tree
       *  @param ownkind  The computed kind of the tree
       *  @param resultInfo  The expected result of the tree
       */
      Type check(final JCTree tree,
                 final Type found,
                 final KindSelector ownkind,
                 final ResultInfo resultInfo) {
          InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
          Type owntype;
          boolean shouldCheck = !found.hasTag(ERROR) &&
                  !resultInfo.pt.hasTag(METHOD) &&
                  !resultInfo.pt.hasTag(FORALL);
          if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
              log.error(tree.pos(),
                        Errors.UnexpectedType(resultInfo.pkind.kindNames(),
                                              ownkind.kindNames()));
              owntype = types.createErrorType(found);
          } else if (allowPoly && inferenceContext.free(found)) {
              //delay the check if there are inference variables in the found type
              //this means we are dealing with a partially inferred poly expression
              owntype = shouldCheck ? resultInfo.pt : found;
              if (resultInfo.checkMode.installPostInferenceHook()) {
                  inferenceContext.addFreeTypeListener(List.of(found),
                          instantiatedContext -> {
                              ResultInfo pendingResult =
                                      resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
                              check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
                          });
              }
          } else {
              owntype = shouldCheck ?
              resultInfo.check(tree, found) :
              found;
          }
          if (resultInfo.checkMode.updateTreeType()) {
              tree.type = owntype;
          }
          return owntype;
      }
  
      /** Is given blank final variable assignable, i.e. in a scope where it
       *  may be assigned to even though it is final?
       *  @param v      The blank final variable.
       *  @param env    The current environment.
       */
      boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
          Symbol owner = env.info.scope.owner;
             // owner refers to the innermost variable, method or
             // initializer block declaration at this point.
          boolean isAssignable =
              v.owner == owner
              ||
              ((owner.name == names.init ||    // i.e. we are in a constructor
                owner.kind == VAR ||           // i.e. we are in a variable initializer
                (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
               &&
               v.owner == owner.owner
               &&
               ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
          boolean insideCompactConstructor = env.enclMethod != null && TreeInfo.isCompactConstructor(env.enclMethod);
          return isAssignable & !insideCompactConstructor;
      }
  
      /** Check that variable can be assigned to.
       *  @param pos    The current source code position.
       *  @param v      The assigned variable
       *  @param base   If the variable is referred to in a Select, the part
       *                to the left of the `.', null otherwise.
       *  @param env    The current environment.
       */
      void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
          if (v.name == names._this) {
              log.error(pos, Errors.CantAssignValToThis);
          } else if ((v.flags() & FINAL) != 0 &&
              ((v.flags() & HASINIT) != 0
               ||
               !((base == null ||
                 TreeInfo.isThisQualifier(base)) &&
                 isAssignableAsBlankFinal(v, env)))) {
              if (v.isResourceVariable()) { //TWR resource
                  log.error(pos, Errors.TryResourceMayNotBeAssigned(v));
              } else {
                  log.error(pos, Errors.CantAssignValToFinalVar(v));
              }
          }
      }
  
      /** Does tree represent a static reference to an identifier?
       *  It is assumed that tree is either a SELECT or an IDENT.
       *  We have to weed out selects from non-type names here.
       *  @param tree    The candidate tree.
       */
      boolean isStaticReference(JCTree tree) {
          if (tree.hasTag(SELECT)) {
              Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
              if (lsym == null || lsym.kind != TYP) {
                  return false;
              }
          }
          return true;
      }
  
      /** Is this symbol a type?
       */
      static boolean isType(Symbol sym) {
          return sym != null && sym.kind == TYP;
      }
  
      /** The current `this' symbol.
       *  @param env    The current environment.
       */
      Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
          return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
      }
  
      /** Attribute a parsed identifier.
       * @param tree Parsed identifier name
       * @param topLevel The toplevel to use
       */
      public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
          Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
          localEnv.enclClass = make.ClassDef(make.Modifiers(0),
                                             syms.errSymbol.name,
                                             null, null, null, null);
          localEnv.enclClass.sym = syms.errSymbol;
          return attribIdent(tree, localEnv);
      }
  
      /** Attribute a parsed identifier.
       * @param tree Parsed identifier name
       * @param env The env to use
       */
      public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
          return tree.accept(identAttributer, env);
      }
      // where
          private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
          private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
              @Override @DefinedBy(Api.COMPILER_TREE)
              public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
                  Symbol site = visit(node.getExpression(), env);
                  if (!site.kind.isValid())
                      return site;
                  Name name = (Name)node.getIdentifier();
                  if (site.kind == PCK) {
                      env.toplevel.packge = (PackageSymbol)site;
                      return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
                              KindSelector.TYP_PCK);
                  } else {
                      env.enclClass.sym = (ClassSymbol)site;
                      return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
                  }
              }
  
              @Override @DefinedBy(Api.COMPILER_TREE)
              public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
                  return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
              }
          }
  
      public Type coerce(Type etype, Type ttype) {
          return cfolder.coerce(etype, ttype);
      }
  
      public Type attribType(JCTree node, TypeSymbol sym) {
          Env<AttrContext> env = typeEnvs.get(sym);
          Env<AttrContext> localEnv = env.dup(node, env.info.dup());
          return attribTree(node, localEnv, unknownTypeInfo);
      }
  
      public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
          // Attribute qualifying package or class.
          JCFieldAccess s = (JCFieldAccess)tree.qualid;
          return attribTree(s.selected, env,
                            new ResultInfo(tree.staticImport ?
                                           KindSelector.TYP : KindSelector.TYP_PCK,
                         Type.noType));
      }
  
      public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
          return attribToTree(expr, env, tree, unknownExprInfo);
      }
  
      public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
          return attribToTree(stmt, env, tree, statInfo);
      }
  
      private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
          Env<AttrContext> localEnv = env.dup(env.tree, env.info.dup(env.info.scope.dupUnshared()));
  		breakTree = tree;
          JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
          try {
  
              deferredAttr.attribSpeculative(root, env, resultInfo,
                      null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
  
                      argumentAttr.withLocalCacheContext());
              attrRecover.doRecovery();
          } catch (BreakAttr b) {
              return b.env;
          } catch (AssertionError ae) {
              if (ae.getCause() instanceof BreakAttr) {
                  return ((BreakAttr)(ae.getCause())).env;
              } else {
                  throw ae;
              }
          } finally {
              breakTree = null;
              log.useSource(prev);
          }
          return localEnv;
      }
  
      private JCTree breakTree = null;
  
      public static class BreakAttr extends RuntimeException {
          static final long serialVersionUID = -6924771130405446405L;
          private transient Env<AttrContext> env;
          private final Type result;
          private BreakAttr(Env<AttrContext> env, Type result) {
              this.env = env;
              this.result = result;
          }
      }
  
      /**
       * Mode controlling behavior of Attr.Check
       */
      enum CheckMode {
  
          NORMAL,
  
          /**
           * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
           * that the captured var cache in {@code InferenceContext} will be used in read-only
           * mode when performing inference checks.
           */
          NO_TREE_UPDATE {
              @Override
              public boolean updateTreeType() {
                  return false;
              }
          },
          /**
           * Mode signalling that caller will manage free types in tree decorations.
           */
          NO_INFERENCE_HOOK {
              @Override
              public boolean installPostInferenceHook() {
                  return false;
              }
          };
  
          public boolean updateTreeType() {
              return true;
          }
          public boolean installPostInferenceHook() {
              return true;
          }
      }
  
  
      class ResultInfo {
          final KindSelector pkind;
          final Type pt;
          final CheckContext checkContext;
          final CheckMode checkMode;
  
          ResultInfo(KindSelector pkind, Type pt) {
              this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
          }
  
          ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
              this(pkind, pt, chk.basicHandler, checkMode);
          }
  
          protected ResultInfo(KindSelector pkind,
                               Type pt, CheckContext checkContext) {
              this(pkind, pt, checkContext, CheckMode.NORMAL);
          }
  
          protected ResultInfo(KindSelector pkind,
                               Type pt, CheckContext checkContext, CheckMode checkMode) {
              this.pkind = pkind;
              this.pt = pt;
              this.checkContext = checkContext;
              this.checkMode = checkMode;
          }
  
          /**
           * Should {@link Attr#attribTree} use the {@ArgumentAttr} visitor instead of this one?
           * @param tree The tree to be type-checked.
           * @return true if {@ArgumentAttr} should be used.
           */
          protected boolean needsArgumentAttr(JCTree tree) { return false; }
  
          protected Type check(final DiagnosticPosition pos, final Type found) {
              return chk.checkType(pos, found, pt, checkContext);
          }
  
          protected ResultInfo dup(Type newPt) {
              return new ResultInfo(pkind, newPt, checkContext, checkMode);
          }
  
          protected ResultInfo dup(CheckContext newContext) {
              return new ResultInfo(pkind, pt, newContext, checkMode);
          }
  
          protected ResultInfo dup(Type newPt, CheckContext newContext) {
              return new ResultInfo(pkind, newPt, newContext, checkMode);
          }
  
          protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
              return new ResultInfo(pkind, newPt, newContext, newMode);
          }
  
          protected ResultInfo dup(CheckMode newMode) {
              return new ResultInfo(pkind, pt, checkContext, newMode);
          }
  
          @Override
          public String toString() {
              if (pt != null) {
                  return pt.toString();
              } else {
                  return "";
              }
          }
      }
  
      class MethodAttrInfo extends ResultInfo {
          public MethodAttrInfo() {
              this(chk.basicHandler);
          }
  
          public MethodAttrInfo(CheckContext checkContext) {
              super(KindSelector.VAL, Infer.anyPoly, checkContext);
          }
  
          @Override
          protected boolean needsArgumentAttr(JCTree tree) {
              return true;
          }
  
          protected ResultInfo dup(Type newPt) {
              throw new IllegalStateException();
          }
  
          protected ResultInfo dup(CheckContext newContext) {
              return new MethodAttrInfo(newContext);
          }
  
          protected ResultInfo dup(Type newPt, CheckContext newContext) {
              throw new IllegalStateException();
          }
  
          protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
              throw new IllegalStateException();
          }
  
          protected ResultInfo dup(CheckMode newMode) {
              throw new IllegalStateException();
          }
      }
  
      class RecoveryInfo extends ResultInfo {
  
          public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
              this(deferredAttrContext, Type.recoveryType);
          }
  
          public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
              super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
                  @Override
                  public DeferredAttr.DeferredAttrContext deferredAttrContext() {
                      return deferredAttrContext;
                  }
                  @Override
                  public boolean compatible(Type found, Type req, Warner warn) {
                      return true;
                  }
                  @Override
                  public void report(DiagnosticPosition pos, JCDiagnostic details) {
                      if (pt == Type.recoveryType) {
                          chk.basicHandler.report(pos, details);
                      }
                  }
              });
          }
      }
  
      final ResultInfo statInfo;
      final ResultInfo varAssignmentInfo;
      final ResultInfo methodAttrInfo;
      final ResultInfo unknownExprInfo;
      final ResultInfo unknownTypeInfo;
      final ResultInfo unknownTypeExprInfo;
      final ResultInfo recoveryInfo;
  
      Type pt() {
          return resultInfo.pt;
      }
  
      KindSelector pkind() {
          return resultInfo.pkind;
      }
  
  /* ************************************************************************
   * Visitor methods
   *************************************************************************/
  
      /** Visitor argument: the current environment.
       */
      Env<AttrContext> env;
  
      /** Visitor argument: the currently expected attribution result.
       */
      ResultInfo resultInfo;
  
      /** Visitor result: the computed type.
       */
      Type result;
  
      MatchBindings matchBindings = MatchBindingsComputer.EMPTY;
  
      /** Visitor method: attribute a tree, catching any completion failure
       *  exceptions. Return the tree's type.
       *
       *  @param tree    The tree to be visited.
       *  @param env     The environment visitor argument.
       *  @param resultInfo   The result info visitor argument.
       */
      Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
          Env<AttrContext> prevEnv = this.env;
          ResultInfo prevResult = this.resultInfo;
          try {
              this.env = env;
              this.resultInfo = resultInfo;
              try {
                  if (resultInfo.needsArgumentAttr(tree)) {
                      result = argumentAttr.attribArg(tree, env);
                  } else {
                      tree.accept(this);
                  }
              } catch (Resolve.InapplicableMethodException ime) {
                  if (tree != breakTree ||
                          resultInfo.checkContext.deferredAttrContext().mode != AttrMode.CHECK) {
                      throw ime;
                  }
              }
              matchBindings = matchBindingsComputer.finishBindings(tree,
  			                                                     matchBindings);
              if (tree == breakTree &&
                      resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
                  breakTreeFound(copyEnv(env), result);
              }
              return result;
          } catch (CompletionFailure ex) {
              tree.type = syms.errType;
              return chk.completionError(tree.pos(), ex);
          } finally {
              this.env = prevEnv;
              this.resultInfo = prevResult;
          }
      }
  
      protected void breakTreeFound(Env<AttrContext> env, Type result) {
          throw new BreakAttr(env, result);
      }
  
      Env<AttrContext> copyEnv(Env<AttrContext> env) {
          Env<AttrContext> newEnv =
                  env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
          if (newEnv.outer != null) {
              newEnv.outer = copyEnv(newEnv.outer);
          }
          return newEnv;
      }
  
      WriteableScope copyScope(WriteableScope sc) {
          WriteableScope newScope = WriteableScope.create(sc.owner);
          List<Symbol> elemsList = List.nil();
          for (Symbol sym : sc.getSymbols()) {
              elemsList = elemsList.prepend(sym);
          }
          for (Symbol s : elemsList) {
              newScope.enter(s);
          }
          return newScope;
      }
  
      /** Derived visitor method: attribute an expression tree.
       */
      public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
          return attribTree(tree, env, new ResultInfo(KindSelector.VAL, pt != null && !pt.hasTag(ERROR) ? pt : Type.noType));
      }
  
      /** Derived visitor method: attribute an expression tree with
       *  no constraints on the computed type.
       */
      public Type attribExpr(JCTree tree, Env<AttrContext> env) {
          return attribTree(tree, env, unknownExprInfo);
      }
  
      /** Derived visitor method: attribute a type tree.
       */
      public Type attribType(JCTree tree, Env<AttrContext> env) {
          Type result = attribType(tree, env, Type.noType);
          return result;
      }
  
      /** Derived visitor method: attribute a type tree.
       */
      Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
          Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
          return result;
      }
  
      /** Derived visitor method: attribute a statement or definition tree.
       */
      public Type attribStat(JCTree tree, Env<AttrContext> env) {
          Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
          try {
          Type result = attribTree(tree, env, statInfo);
          } catch (BreakAttr ba) {
              throw ba;
          } 
          analyzer.analyzeIfNeeded(tree, analyzeEnv);
          attrRecover.doRecovery();
          return result;
      }
  
      /** Attribute a list of expressions, returning a list of types.
       */
      List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
          ListBuffer<Type> ts = new ListBuffer<>();
          for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
              ts.append(attribExpr(l.head, env, pt));
          return ts.toList();
      }
  
      /** Attribute a list of statements, returning nothing.
       */
      <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
          for (List<T> l = trees; l.nonEmpty(); l = l.tail)
              attribStat(l.head, env);
      }
  
      /** Attribute the arguments in a method call, returning the method kind.
       */
      KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
          KindSelector kind = initialKind;
          for (JCExpression arg : trees) {
              try {
                  Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, allowPoly ? methodAttrInfo : unknownExprInfo));
                  if (argtype.hasTag(DEFERRED)) {
                      kind = KindSelector.of(KindSelector.POLY, kind);
                  }
                  argtypes.append(argtype);
              } catch (BreakAttr ba) {
                  if (ba.result != null && !ba.result.hasTag(PACKAGE) && !ba.result.hasTag(METHOD) && env.tree == ba.env.tree) {
                      argtypes.append(chk.checkNonVoid(arg, ba.result));
                  }
                  throw ba;
              }
          }
          return kind;
      }
  
      /** Attribute a type argument list, returning a list of types.
       *  Caller is responsible for calling checkRefTypes.
       */
      List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
          ListBuffer<Type> argtypes = new ListBuffer<>();
          for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
              argtypes.append(attribType(l.head, env));
          return argtypes.toList();
      }
  
      /** Attribute a type argument list, returning a list of types.
       *  Check that all the types are references.
       */
      List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
          List<Type> types = attribAnyTypes(trees, env);
          return chk.checkRefTypes(trees, types);
      }
  
      /**
       * Attribute type variables (of generic classes or methods).
       * Compound types are attributed later in attribBounds.
       * @param typarams the type variables to enter
       * @param env      the current environment
       */
      void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
          for (JCTypeParameter tvar : typarams) {
              TypeVar a = (TypeVar)tvar.type;
              a.tsym.flags_field |= UNATTRIBUTED;
              a.setUpperBound(Type.noType);
              if (!tvar.bounds.isEmpty()) {
                  List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
                  for (JCExpression bound : tvar.bounds.tail)
                      bounds = bounds.prepend(attribType(bound, env));
                  types.setBounds(a, bounds.reverse());
              } else {
                  // if no bounds are given, assume a single bound of
                  // java.lang.Object.
                  types.setBounds(a, List.of(syms.objectType));
              }
              a.tsym.flags_field &= ~UNATTRIBUTED;
          }
          if (checkCyclic) {
              for (JCTypeParameter tvar : typarams) {
                  chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
              }
          }
      }
  
      /**
       * Attribute the type references in a list of annotations.
       */
      void attribAnnotationTypes(List<JCAnnotation> annotations,
                                 Env<AttrContext> env) {
          for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
              JCAnnotation a = al.head;
              attribType(a.annotationType, env);
          }
      }
  
      /**
       * Attribute a "lazy constant value".
       *  @param env         The env for the const value
       *  @param variable    The initializer for the const value
       *  @param type        The expected type, or null
       *  @see VarSymbol#setLazyConstValue
       */
      public Object attribLazyConstantValue(Env<AttrContext> env,
                                        JCVariableDecl variable,
                                        Type type) {
  
          DiagnosticPosition prevLintPos
                  = deferredLintHandler.setPos(variable.pos());
  
          final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
          try {
              if (variable.init == null) {
                  return null;
              }
              Type itype = attribExpr(variable.init, env, type);
              if (variable.isImplicitlyTyped()) {
                  //fixup local variable type
                  type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype.baseType(), variable.name);
              }
              if (itype.constValue() != null) {
                  return coerce(itype, type).constValue();
              } else {
                  return null;
              }
          } finally {
              log.useSource(prevSource);
              deferredLintHandler.setPos(prevLintPos);
          }
      }
  
      /** Attribute type reference in an `extends' or `implements' clause.
       *  Supertypes of anonymous inner classes are usually already attributed.
       *
       *  @param tree              The tree making up the type reference.
       *  @param env               The environment current at the reference.
       *  @param classExpected     true if only a class is expected here.
       *  @param interfaceExpected true if only an interface is expected here.
       */
      Type attribBase(JCTree tree,
                      Env<AttrContext> env,
                      boolean classExpected,
                      boolean interfaceExpected,
                      boolean checkExtensible) {
          Type t = tree.type != null ?
              tree.type :
              attribType(tree, env);
          return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
      }
      Type checkBase(Type t,
                     JCTree tree,
                     Env<AttrContext> env,
                     boolean classExpected,
                     boolean interfaceExpected,
                     boolean checkExtensible) {
          final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
                  (((JCTypeApply) tree).clazz).pos() : tree.pos();
          if (t.tsym.isAnonymous()) {
              log.error(pos, Errors.CantInheritFromAnon);
              return types.createErrorType(t);
          }
          if (t.isErroneous())
              return t;
          if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
              // check that type variable is already visible
              if (t.getUpperBound() == null) {
                  log.error(pos, Errors.IllegalForwardRef);
                  return types.createErrorType(t);
              }
          } else {
              t = chk.checkClassType(pos, t, checkExtensible);
          }
          if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
              log.error(pos, Errors.IntfExpectedHere);
              // return errType is necessary since otherwise there might
              // be undetected cycles which cause attribution to loop
              return types.createErrorType(t);
          } else if (checkExtensible &&
                     classExpected &&
                     (t.tsym.flags() & INTERFACE) != 0) {
              log.error(pos, Errors.NoIntfExpectedHere);
              return types.createErrorType(t);
          }
          if (checkExtensible &&
              ((t.tsym.flags() & FINAL) != 0)) {
              log.error(pos,
                        Errors.CantInheritFromFinal(t.tsym));
          }
          chk.checkNonCyclic(pos, t);
          return t;
      }
  
      Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
          Assert.check((env.enclClass.sym.flags() & ENUM) != 0 || env.enclClass.sym.kind == ERR);
          id.type = env.info.scope.owner.enclClass().type;
          id.sym = env.info.scope.owner.enclClass();
          return id.type;
      }
  
      public void visitClassDef(JCClassDecl tree) {
          Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
                  Optional.ofNullable(env.info.attributionMode.isSpeculative ?
                          argumentAttr.withLocalCacheContext() : null);
          try {
              // Local and anonymous classes have not been entered yet, so we need to
              // do it now.
              if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)
                      && (env.info.scope.owner.kind != ERR || tree.sym == null)) {
                  enter.classEnter(tree, env);
              } else {
                  // If this class declaration is part of a class level annotation,
                  // as in @MyAnno(new Object() {}) class MyClass {}, enter it in
                  // order to simplify later steps and allow for sensible error
                  // messages.
                  if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
                      enter.classEnter(tree, env);
              }
  
              ClassSymbol c = tree.sym;
              if (c == null) {
                  // exit in case something drastic went wrong during enter.
                  result = null;
              } else {
                  // make sure class has been completed:
                  c.complete();
  
                  // If this class appears as an anonymous class
                  // in a superclass constructor call
                  // disable implicit outer instance from being passed.
                  // (This would be an illegal access to "this before super").
                  if (env.info.isSelfCall &&
                          env.tree.hasTag(NEWCLASS)) {
                      c.flags_field |= NOOUTERTHIS;
                  }
                  attribClass(tree.pos(), c);
                  result = tree.type = c.type;
              }
          } finally {
              localCacheContext.ifPresent(LocalCacheContext::leave);
          }
      }
  
      public void visitMethodDef(JCMethodDecl tree) {
          MethodSymbol m = tree.sym;
          if (m == null) {
              // exit in case something drastic went wrong during enter.
              result = null;
              return;
          }
          boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
  
          Lint lint = env.info.lint.augment(m);
          Lint prevLint = chk.setLint(lint);
          MethodSymbol prevMethod = chk.setMethod(m);
          try {
              deferredLintHandler.flush(tree.pos());
              chk.checkDeprecatedAnnotation(tree.pos(), m);
  
  
              // Create a new environment with local scope
              // for attributing the method.
              Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
              localEnv.info.lint = lint;
  
              attribStats(tree.typarams, localEnv);
  
              // If we override any other methods, check that we do so properly.
              // JLS ???
              if (m.isStatic()) {
                  chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
              } else {
                  chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
              }
              chk.checkOverride(env, tree, m);
  
              if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
                  log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
              }
  
              // Enter all type parameters into the local method scope.
              for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
                  localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
  
              ClassSymbol owner = env.enclClass.sym;
              if ((owner.flags() & ANNOTATION) != 0 &&
                      (tree.params.nonEmpty() ||
                      tree.recvparam != null))
                  log.error(tree.params.nonEmpty() ?
                          tree.params.head.pos() :
                          tree.recvparam.pos(),
                          Errors.IntfAnnotationMembersCantHaveParams);
  
              // Attribute all value parameters.
              for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
                  attribStat(l.head, localEnv);
              }
  
              chk.checkVarargsMethodDecl(localEnv, tree);
  
              // Check that type parameters are well-formed.
              chk.validate(tree.typarams, localEnv);
  
              // Check that result type is well-formed.
              if (tree.restype != null && !tree.restype.type.hasTag(VOID))
                  chk.validate(tree.restype, localEnv);
  
              // Check that receiver type is well-formed.
              if (tree.recvparam != null) {
                  // Use a new environment to check the receiver parameter.
                  // Otherwise I get "might not have been initialized" errors.
                  // Is there a better way?
                  Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
                  attribType(tree.recvparam, newEnv);
                  chk.validate(tree.recvparam, newEnv);
              }
  
              if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP) {
                  // lets find if this method is an accessor
                  Optional<? extends RecordComponent> recordComponent = env.enclClass.sym.getRecordComponents().stream()
                          .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
                  if (recordComponent.isPresent()) {
                      // the method is a user defined accessor lets check that everything is fine
                      if (!tree.sym.isPublic()) {
                          log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.MethodMustBePublic));
                      }
                      if (!types.isSameType(tree.sym.type.getReturnType(), recordComponent.get().type)) {
                          log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym,
                                  Fragments.AccessorReturnTypeDoesntMatch(tree.sym, recordComponent.get())));
                      }
                      if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
                          log.error(tree,
                                  Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodCantThrowException));
                      }
                      if (!tree.typarams.isEmpty()) {
                          log.error(tree,
                                  Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeGeneric));
                      }
                      if (tree.sym.isStatic()) {
                          log.error(tree,
                                  Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeStatic));
                      }
                  }
  
                  if (tree.name == names.init) {
                      // if this a constructor other than the canonical one
                      if ((tree.sym.flags_field & RECORD) == 0) {
                          JCMethodInvocation app = TreeInfo.firstConstructorCall(tree);
                          if (app == null ||
                                  TreeInfo.name(app.meth) != names._this ||
                                  !checkFirstConstructorStat(app, tree, false)) {
                              log.error(tree, Errors.FirstStatementMustBeCallToAnotherConstructor(env.enclClass.sym));
                          }
                      } else {
                          // but if it is the canonical:
  
                          /* if user generated, then it shouldn't:
                           *     - have an accessibility stricter than that of the record type
                           *     - explicitly invoke any other constructor
                           */
                          if ((tree.sym.flags_field & GENERATEDCONSTR) == 0) {
                              if (Check.protection(m.flags()) > Check.protection(env.enclClass.sym.flags())) {
                                  log.error(tree,
                                          (env.enclClass.sym.flags() & AccessFlags) == 0 ?
                                              Errors.InvalidCanonicalConstructorInRecord(
                                                  Fragments.Canonical,
                                                  env.enclClass.sym.name,
                                                  Fragments.CanonicalMustNotHaveStrongerAccess("package")
                                              ) :
                                              Errors.InvalidCanonicalConstructorInRecord(
                                                      Fragments.Canonical,
                                                      env.enclClass.sym.name,
                                                      Fragments.CanonicalMustNotHaveStrongerAccess(asFlagSet(env.enclClass.sym.flags() & AccessFlags))
                                              )
                                  );
                              }
  
                              JCMethodInvocation app = TreeInfo.firstConstructorCall(tree);
                              if (app != null &&
                                      (TreeInfo.name(app.meth) == names._this ||
                                              TreeInfo.name(app.meth) == names._super) &&
                                      checkFirstConstructorStat(app, tree, false)) {
                                  log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
                                          Fragments.Canonical, env.enclClass.sym.name,
                                          Fragments.CanonicalMustNotContainExplicitConstructorInvocation));
                              }
                          }
  
                          // also we want to check that no type variables have been defined
                          if (!tree.typarams.isEmpty()) {
                              log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
                                      Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalMustNotDeclareTypeVariables));
                          }
  
                          /* and now we need to check that the constructor's arguments are exactly the same as those of the
                           * record components
                           */
                          List<? extends RecordComponent> recordComponents = env.enclClass.sym.getRecordComponents();
                          List<Type> recordFieldTypes = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.type);
                          for (JCVariableDecl param: tree.params) {
                              boolean paramIsVarArgs = (param.sym.flags_field & VARARGS) != 0;
                              if (!types.isSameType(param.type, recordFieldTypes.head) ||
                                      (recordComponents.head.isVarargs() != paramIsVarArgs)) {
                                  log.error(param, Errors.InvalidCanonicalConstructorInRecord(
                                          Fragments.Canonical, env.enclClass.sym.name,
                                          Fragments.TypeMustBeIdenticalToCorrespondingRecordComponentType));
                              }
                              recordComponents = recordComponents.tail;
                              recordFieldTypes = recordFieldTypes.tail;
                          }
                      }
                  }
              }
  
              // annotation method checks
              if ((owner.flags() & ANNOTATION) != 0) {
                  // annotation method cannot have throws clause
                  if (tree.thrown.nonEmpty()) {
                      log.error(tree.thrown.head.pos(),
                                Errors.ThrowsNotAllowedInIntfAnnotation);
                  }
                  // annotation method cannot declare type-parameters
                  if (tree.typarams.nonEmpty()) {
                      log.error(tree.typarams.head.pos(),
                                Errors.IntfAnnotationMembersCantHaveTypeParams);
                  }
                  // validate annotation method's return type (could be an annotation type)
                  chk.validateAnnotationType(tree.restype);
                  // ensure that annotation method does not clash with members of Object/Annotation
                  chk.validateAnnotationMethod(tree.pos(), m);
              }
  
              for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
                  chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
  
              if (tree.body == null) {
                  // Empty bodies are only allowed for
                  // abstract, native, or interface methods, or for methods
                  // in a retrofit signature class.
                  if (tree.defaultValue != null) {
                      if ((owner.flags() & ANNOTATION) == 0)
                          log.error(tree.pos(),
                                    Errors.DefaultAllowedInIntfAnnotationMember);
                  }
                  if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
                      log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract);
              } else if ((tree.sym.flags() & (ABSTRACT | DEFAULT | PRIVATE)) == ABSTRACT) {
                  if ((owner.flags() & INTERFACE) != 0) {
                      log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
                  } else {
                      log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
                  }
              } else if ((tree.mods.flags & NATIVE) != 0) {
                  log.error(tree.pos(), Errors.NativeMethCantHaveBody);
              } else {
                  // Add an implicit super() call unless an explicit call to
                  // super(...) or this(...) is given
                  // or we are compiling class java.lang.Object.
                  if (tree.name == names.init && !owner.type.isErroneous() && owner.type != syms.objectType) {
                      JCBlock body = tree.body;
                      if (body.stats.isEmpty()
                              || TreeInfo.getConstructorInvocationName(body.stats, names) == names.empty) {
                          JCStatement supCall = make.at(body.pos).Exec(make.Apply(List.nil(),
                                  make.Ident(names._super), make.Idents(List.nil())));
                          body.stats = body.stats.prepend(supCall);
                      } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
                              (tree.mods.flags & GENERATEDCONSTR) == 0 &&
                              TreeInfo.isSuperCall(body.stats.head)) {
                          // enum constructors are not allowed to call super
                          // directly, so make sure there aren't any super calls
                          // in enum constructors, except in the compiler
                          // generated one.
                          log.error(tree.body.stats.head.pos(),
                                  Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
                      }
                      if (env.enclClass.sym.isRecord() && (tree.sym.flags_field & RECORD) != 0) { // we are seeing the canonical constructor
                          List<Name> recordComponentNames = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.name);
                          List<Name> initParamNames = tree.sym.params.map(p -> p.name);
                          if (!initParamNames.equals(recordComponentNames)) {
                              log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
                                      Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalWithNameMismatch));
                          }
                          if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
                              log.error(tree,
                                      Errors.InvalidCanonicalConstructorInRecord(
                                              TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical,
                                              env.enclClass.sym.name,
                                              Fragments.ThrowsClauseNotAllowedForCanonicalConstructor(
                                                      TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical)));
                          }
                      }
                  }
  
                  if (!isBackgroundCompilation) {
                      tree.localEnv = dupLocalEnv(localEnv);
                  }
  
                  // Attribute all type annotations in the body
                  annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m, null);
                  annotate.flush();
  
                  // Attribute method body.
                  attribStat(tree.body, localEnv);
              }
  
              localEnv.info.scope.leave();
              result = tree.type = m.type;
          } finally {
              chk.setLint(prevLint);
              chk.setMethod(prevMethod);
          }
      }
  
      public void visitVarDef(JCVariableDecl tree) {
          // Local variables have not been entered yet, so we need to do it now:
          if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
              if (tree.sym != null) {
                  // parameters have already been entered
                  env.info.scope.enter(tree.sym);
              } else {
                  if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0) {
                      if (tree.init == null) {
                          //cannot use 'var' without initializer
                          log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
                          tree.vartype = make.Erroneous();
                      } else {
                          Fragment msg = canInferLocalVarType(tree);
                          if (msg != null) {
                              //cannot use 'var' with initializer which require an explicit target
                              //(e.g. lambda, method reference, array initializer).
                              log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
                              tree.vartype = make.Erroneous();
                          }
                      }
                  }
                  try {
                      annotate.blockAnnotations();
                      memberEnter.memberEnter(tree, env);
                  } finally {
                      annotate.unblockAnnotations();
                  }
              }
          } else {
              if (tree.init != null) {
                  // Field initializer expression need to be entered.
                  annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym, tree.pos());
                  annotate.flush();
              }
          }
  
          VarSymbol v = tree.sym;
          if (v == null) {
              // exit in case something drastic went wrong during enter.
              result = null;
              return;
          }
          Lint lint = env.info.lint.augment(v);
          Lint prevLint = chk.setLint(lint);
  
          // Check that the variable's declared type is well-formed.
          boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
                  ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
                  (tree.sym.flags() & PARAMETER) != 0;
          chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
  
          try {
              v.getConstValue(); // ensure compile-time constant initializer is evaluated
              deferredLintHandler.flush(tree.pos());
              chk.checkDeprecatedAnnotation(tree.pos(), v);
  
              if (tree.init != null) {
                  if ((v.flags_field & FINAL) == 0 ||
                      !memberEnter.needsLazyConstValue(tree.init)) {
                      // Not a compile-time constant
                      // Attribute initializer in a new environment
                      // with the declared variable as owner.
                      // Check that initializer conforms to variable's declared type.
                      Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
                      initEnv.info.lint = lint;
                      // In order to catch self-references, we set the variable's
                      // declaration position to maximal possible value, effectively
                      // marking the variable as undefined.
                      initEnv.info.enclVar = v;
                      attribExpr(tree.init, initEnv, v.type);
                      if (tree.isImplicitlyTyped()) {
                          //fixup local variable type
                          v.type = chk.checkLocalVarType(tree, tree.init.type.baseType(), tree.name);
                      }
                  }
                  if (tree.isImplicitlyTyped()) {
                      setSyntheticVariableType(tree, v.type);
                  }
              }
              result = tree.type = v.type;
              if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP && !v.isStatic()) {
                  if (isNonArgsMethodInObject(v.name)) {
                      log.error(tree, Errors.IllegalRecordComponentName(v));
                  }
              }
          }
          finally {
              chk.setLint(prevLint);
          }
      }
  
      private boolean isNonArgsMethodInObject(Name name) {
          for (Symbol s : syms.objectType.tsym.members().getSymbolsByName(name, s -> s.kind == MTH)) {
              if (s.type.getParameterTypes().isEmpty()) {
                  return true;
              }
          }
          return false;
      }
  
      Fragment canInferLocalVarType(JCVariableDecl tree) {
          LocalInitScanner lis = new LocalInitScanner();
          lis.scan(tree.init);
          return lis.badInferenceMsg;
      }
  
      static class LocalInitScanner extends TreeScanner {
          Fragment badInferenceMsg = null;
          boolean needsTarget = true;
  
          @Override
          public void visitNewArray(JCNewArray tree) {
              if (tree.elemtype == null && needsTarget) {
                  badInferenceMsg = Fragments.LocalArrayMissingTarget;
              }
          }
  
          @Override
          public void visitLambda(JCLambda tree) {
              if (needsTarget) {
                  badInferenceMsg = Fragments.LocalLambdaMissingTarget;
              }
          }
  
          @Override
          public void visitTypeCast(JCTypeCast tree) {
              boolean prevNeedsTarget = needsTarget;
              try {
                  needsTarget = false;
                  super.visitTypeCast(tree);
              } finally {
                  needsTarget = prevNeedsTarget;
              }
          }
  
          @Override
          public void visitReference(JCMemberReference tree) {
              if (needsTarget) {
                  badInferenceMsg = Fragments.LocalMrefMissingTarget;
              }
          }
  
          @Override
          public void visitNewClass(JCNewClass tree) {
              boolean prevNeedsTarget = needsTarget;
              try {
                  needsTarget = false;
                  super.visitNewClass(tree);
              } finally {
                  needsTarget = prevNeedsTarget;
              }
          }
  
          @Override
          public void visitApply(JCMethodInvocation tree) {
              boolean prevNeedsTarget = needsTarget;
              try {
                  needsTarget = false;
                  super.visitApply(tree);
              } finally {
                  needsTarget = prevNeedsTarget;
              }
          }
      }
  
      public void visitSkip(JCSkip tree) {
          result = null;
      }
  
      public void visitBlock(JCBlock tree) {
          if (env.info.scope != null && env.info.scope.owner != null && (env.info.scope.owner.kind == TYP || env.info.scope.owner.kind == ERR)) {
              // Block is a static or instance initializer;
              // let the owner of the environment be a freshly
              // created BLOCK-method.
              Symbol fakeOwner =
                  new MethodSymbol(tree.flags | BLOCK |
                      env.info.scope.owner.flags() & STRICTFP, names.empty, null,
                      env.info.scope.owner);
              final Env<AttrContext> localEnv =
                  env.dup(tree, env.info.dup(env.info.scope.dupUnshared(fakeOwner)));
  
              if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
              // Attribute all type annotations in the block
              annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner, null);
              annotate.flush();
              attribStats(tree.stats, localEnv);
  
              {
                  // Store init and clinit type annotations with the ClassSymbol
                  // to allow output in Gen.normalizeDefs.
                  ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
                  List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
                  if ((tree.flags & STATIC) != 0) {
                      cs.appendClassInitTypeAttributes(tas);
                  } else {
                      cs.appendInitTypeAttributes(tas);
                  }
              }
          } else {
              // Create a new local environment with a local scope.
              Env<AttrContext> localEnv =
                  env.dup(tree, env.info.dup((env.info.scope != null ? env.info.scope : WriteableScope.create(syms.noSymbol)).dup()));
              try {
                  attribStats(tree.stats, localEnv);
              } finally {
                  localEnv.info.scope.leave();
              }
          }
          result = null;
      }
  
      public void visitDoLoop(JCDoWhileLoop tree) {
          attribStat(tree.body, env.dup(tree));
          attribExpr(tree.cond, env, syms.booleanType);
          if (!breaksOutOf(tree, tree.body)) {
              //include condition's body when false after the while, if cannot get out of the loop
              MatchBindings condBindings = matchBindings;
              condBindings.bindingsWhenFalse.forEach(env.info.scope::enter);
              condBindings.bindingsWhenFalse.forEach(BindingSymbol::preserveBinding);
          }
          result = null;
      }
  
      public void visitWhileLoop(JCWhileLoop tree) {
          attribExpr(tree.cond, env, syms.booleanType);
          MatchBindings condBindings = matchBindings;
          // include condition's bindings when true in the body:
          Env<AttrContext> whileEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
          try {
              attribStat(tree.body, whileEnv.dup(tree));
          } finally {
              whileEnv.info.scope.leave();
          }
          if (!breaksOutOf(tree, tree.body)) {
              //include condition's bindings when false after the while, if cannot get out of the loop
              condBindings.bindingsWhenFalse.forEach(env.info.scope::enter);
              condBindings.bindingsWhenFalse.forEach(BindingSymbol::preserveBinding);
          }
          result = null;
      }
  
      private boolean breaksOutOf(JCTree loop, JCTree body) {
          preFlow(body);
          return flow.breaksOutOf(env, loop, body, make);
      }
  
      public void visitForLoop(JCForLoop tree) {
          Env<AttrContext> loopEnv =
              env.dup(env.tree, env.info.dup(env.info.scope.dup()));
          MatchBindings condBindings = MatchBindingsComputer.EMPTY;
          try {
              attribStats(tree.init, loopEnv);
              if (tree.cond != null) {
                  attribExpr(tree.cond, loopEnv, syms.booleanType);
                  // include condition's bindings when true in the body and step:
                  condBindings = matchBindings;
              }
              Env<AttrContext> bodyEnv = bindingEnv(loopEnv, condBindings.bindingsWhenTrue);
              try {
                  bodyEnv.tree = tree; // before, we were not in loop!
                  attribStats(tree.step, bodyEnv);
                  attribStat(tree.body, bodyEnv);
              } finally {
                  bodyEnv.info.scope.leave();
              }
              result = null;
          }
          finally {
              loopEnv.info.scope.leave();
          }
          if (!breaksOutOf(tree, tree.body)) {
              //include condition's body when false after the while, if cannot get out of the loop
              condBindings.bindingsWhenFalse.forEach(env.info.scope::enter);
              condBindings.bindingsWhenFalse.forEach(BindingSymbol::preserveBinding);
          }
      }
  
      public void visitForeachLoop(JCEnhancedForLoop tree) {
          Env<AttrContext> loopEnv =
              env.dup(env.tree, env.info.dup(env.info.scope.dup()));
          try {
              //the Formal Parameter of a for-each loop is not in the scope when
              //attributing the for-each expression; we mimic this by attributing
              //the for-each expression first (against original scope).
              Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
              chk.checkNonVoid(tree.pos(), exprType);
              Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
              if (elemtype == null) {
                  // or perhaps expr implements Iterable<T>?
                  Type base = types.asSuper(exprType, syms.iterableType.tsym);
                  if (base == null) {
                      log.error(tree.expr.pos(),
                                Errors.ForeachNotApplicableToType(exprType,
                                                                  Fragments.TypeReqArrayOrIterable));
                      elemtype = types.createErrorType(exprType);
                  } else {
                      List<Type> iterableParams = base.allparams();
                      elemtype = iterableParams.isEmpty()
                          ? syms.objectType
                          : types.wildUpperBound(iterableParams.head);
  
                      // Check the return type of the method iterator().
                      // This is the bare minimum we need to verify to make sure code generation doesn't crash.
                      Symbol iterSymbol = rs.resolveInternalMethod(tree.pos(),
                              loopEnv, exprType, names.iterator, List.nil(), List.nil());
                      if (types.asSuper(iterSymbol.type.getReturnType(), syms.iteratorType.tsym) == null) {
                          log.error(tree.pos(),
                                  Errors.ForeachNotApplicableToType(exprType, Fragments.TypeReqArrayOrIterable));
                      }
                  }
              }
              if (tree.var.isImplicitlyTyped()) {
                  Type inferredType = chk.checkLocalVarType(tree.var, elemtype, tree.var.name);
                  setSyntheticVariableType(tree.var, inferredType);
              }
              attribStat(tree.var, loopEnv);
              if (tree.var.sym != null)
                  chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
              loopEnv.tree = tree; // before, we were not in loop!
              attribStat(tree.body, loopEnv);
              result = null;
          }
          finally {
              loopEnv.info.scope.leave();
          }
      }
  
      public void visitLabelled(JCLabeledStatement tree) {
          // Check that label is not used in an enclosing statement
          Env<AttrContext> env1 = env;
          while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
              if (env1.tree.hasTag(LABELLED) &&
                  ((JCLabeledStatement) env1.tree).label == tree.label) {
                  log.error(tree.pos(),
                            Errors.LabelAlreadyInUse(tree.label));
                  break;
              }
              env1 = env1.next;
          }
  
          attribStat(tree.body, env.dup(tree));
          result = null;
      }
  
      public void visitSwitch(JCSwitch tree) {
          handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
              attribStats(c.stats, caseEnv);
          });
          result = null;
      }
  
      public void visitSwitchExpression(JCSwitchExpression tree) {
          tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
                  PolyKind.STANDALONE : PolyKind.POLY;
  
          if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
              //this means we are returning a poly conditional from void-compatible lambda expression
              resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
              result = tree.type = types.createErrorType(resultInfo.pt);
              return;
          }
  
          ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
                  unknownExprInfo :
                  resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
  
          ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
          ListBuffer<Type> caseTypes = new ListBuffer<>();
  
          handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
              caseEnv.info.yieldResult = condInfo;
              attribStats(c.stats, caseEnv);
              new TreeScanner() {
                  @Override
                  public void visitYield(JCYield brk) {
                      if (brk.target == tree) {
                          caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
                          caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
                      }
                      super.visitYield(brk);
                  }
  
                  @Override public void visitClassDef(JCClassDecl tree) {}
                  @Override public void visitLambda(JCLambda tree) {}
              }.scan(c.stats);
          });
  
          if (tree.cases.isEmpty()) {
              log.error(tree.pos(),
                        Errors.SwitchExpressionEmpty);
          } else if (caseTypes.isEmpty()) {
              log.error(tree.pos(),
                        Errors.SwitchExpressionNoResultExpressions);
          }
  
          Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
  
          result = tree.type = check(tree, owntype, KindSelector.VAL, resultInfo);
      }
      //where:
          CheckContext switchExpressionContext(CheckContext checkContext) {
              return new Check.NestedCheckContext(checkContext) {
                  //this will use enclosing check context to check compatibility of
                  //subexpression against target type; if we are in a method check context,
                  //depending on whether boxing is allowed, we could have incompatibilities
                  @Override
                  public void report(DiagnosticPosition pos, JCDiagnostic details) {
                      enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
                  }
              };
          }
  
      private void handleSwitch(JCTree switchTree,
                                JCExpression selector,
                                List<JCCase> cases,
                                BiConsumer<JCCase, Env<AttrContext>> attribCase) {
          Type seltype = attribExpr(selector, env);
  
          Env<AttrContext> switchEnv =
              env.dup(switchTree, env.info.dup(env.info.scope.dup()));
  
          try {
              boolean enumSwitch = seltype.tsym != null && (seltype.tsym.flags() & Flags.ENUM) != 0;
              boolean stringSwitch = types.isSameType(seltype, syms.stringType);
              boolean errorEnumSwitch = TreeInfo.isErrorEnumSwitch(selector, cases);
              boolean patternSwitch;
              if (!enumSwitch && !stringSwitch && !errorEnumSwitch &&
                  !types.isAssignable(seltype, syms.intType)) {
                  preview.checkSourceLevel(selector.pos(), Feature.PATTERN_SWITCH);
                  patternSwitch = true;
              } else {
                  patternSwitch = cases.stream()
                                       .flatMap(c -> c.labels.stream())
                                       .anyMatch(l -> l.isPattern());
              }
  
              // Attribute all cases and
              // check that there are no duplicate case labels or default clauses.
              Set<Object> labels = new HashSet<>(); // The set of case labels.
              List<Type> coveredTypes = List.nil();
              boolean hasDefault = false;           // Is there a default label?
              boolean hasTotalPattern = false;      // Is there a total pattern?
              boolean hasNullPattern = false;       // Is there a null pattern?
              CaseTree.CaseKind caseKind = null;
              boolean wasError = false;
              MatchBindings prevBindings = null;
              for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
                  JCCase c = l.head;
                  if (caseKind == null) {
                      caseKind = c.caseKind;
                  } else if (caseKind != c.caseKind && !wasError) {
                      log.error(c.pos(),
                                Errors.SwitchMixingCaseTypes);
                      wasError = true;
                  }
                  MatchBindings currentBindings = prevBindings;
                  boolean wasTotalPattern = hasTotalPattern;
                  for (JCCaseLabel pat : c.labels) {
                      if (pat.isExpression()) {
                          JCExpression expr = (JCExpression) pat;
                          if (TreeInfo.isNull(expr)) {
                              preview.checkSourceLevel(expr.pos(), Feature.CASE_NULL);
                              if (hasNullPattern) {
                                  log.error(pat.pos(), Errors.DuplicateCaseLabel);
                              } else if (wasTotalPattern) {
                                  log.error(pat.pos(), Errors.PatternDominated);
                              }
                              hasNullPattern = true;
                              attribExpr(expr, switchEnv, seltype);
                              matchBindings = new MatchBindings(matchBindings.bindingsWhenTrue, matchBindings.bindingsWhenFalse, true);
                          } else if (enumSwitch) {
                              Symbol sym = enumConstant(expr, seltype);
                              if (sym == null) {
                                  log.error(expr.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
                              } else if (!labels.add(sym)) {
                                  log.error(pat.pos(), Errors.DuplicateCaseLabel);
                              } else {
                                  checkCaseLabelDominated(pat.pos(), coveredTypes, sym.type);
                              }
                          } else if (errorEnumSwitch) {
                              //error recovery: the selector is erroneous, and all the case labels
                              //are identifiers. This could be an enum switch - don't report resolve
                              //error for the case label:
                              Resolve.LogResolveHelper prevResolveHelper = rs.basicLogResolveHelper;
                              try {
                                  rs.basicLogResolveHelper = rs.silentLogResolveHelper;
                                  attribExpr(pat, switchEnv, seltype);
                              } finally {
                                  rs.basicLogResolveHelper = prevResolveHelper;
                              }
                          } else {
                              ResultInfo valTypInfo = new ResultInfo(KindSelector.VAL_TYP,
                                                                     !seltype.hasTag(ERROR) ? seltype
                                                                                            : Type.noType);
                              Type pattype = attribTree(expr, switchEnv, valTypInfo);
                              if (!pattype.hasTag(ERROR)) {
                                  if (pattype.constValue() == null) {
                                      Symbol s = TreeInfo.symbol(expr);
                                      if (s != null && s.kind == TYP && allowPatternSwitch) {
                                          log.error(expr.pos(),
                                                    Errors.PatternExpected);
                                      } else {
                                          log.error(expr.pos(),
                                                    (stringSwitch ? Errors.StringConstReq : Errors.ConstExprReq));
                                      }
                                  } else if (!stringSwitch && !types.isAssignable(seltype, syms.intType)) {
                                      log.error(pat.pos(), Errors.ConstantLabelNotCompatible(pattype, seltype));
                                  } else if (!labels.add(pattype.constValue())) {
                                      log.error(c.pos(), Errors.DuplicateCaseLabel);
                                  } else {
                                      checkCaseLabelDominated(pat.pos(), coveredTypes, types.boxedTypeOrType(pattype));
                                  }
                              }
                          }
                      } else if (pat.hasTag(DEFAULTCASELABEL)) {
                          if (hasDefault) {
                              log.error(pat.pos(), Errors.DuplicateDefaultLabel);
                          } else if (hasTotalPattern) {
                              log.error(pat.pos(), Errors.TotalPatternAndDefault);
                          }
                          hasDefault = true;
                          matchBindings = MatchBindingsComputer.EMPTY;
                      } else {
                          //binding pattern
                          attribExpr(pat, switchEnv);
                          TreeInfo.PatternPrimaryType primary = TreeInfo.primaryPatternType((JCPattern) pat);
                          Type primaryType = primary.type();
                          if (!primaryType.hasTag(TYPEVAR)) {
                              primaryType = chk.checkClassOrArrayType(pat.pos(), primaryType);
                          }
                          checkCastablePattern(pat.pos(), seltype, primaryType);
                          Type patternType = types.erasure(primaryType);
                          boolean isTotal = primary.unconditional() &&
                                            !patternType.isErroneous() &&
                                            types.isSubtype(types.erasure(seltype), patternType);
                          if (isTotal) {
                              if (hasTotalPattern) {
                                  log.error(pat.pos(), Errors.DuplicateTotalPattern);
                              } else if (hasDefault) {
                                  log.error(pat.pos(), Errors.TotalPatternAndDefault);
                              }
                              hasTotalPattern = true;
                          }
                          checkCaseLabelDominated(pat.pos(), coveredTypes, patternType);
                          if (primary.unconditional() && !patternType.isErroneous()) {
                              coveredTypes = coveredTypes.prepend(patternType);
                          }
                      }
                      currentBindings = matchBindingsComputer.switchCase(pat, currentBindings, matchBindings);
                  }
                  if (c == breakTree &&
                          resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK)
                      throw new BreakAttr(env, null);
                  Env<AttrContext> caseEnv =
                          bindingEnv(switchEnv, c, currentBindings.bindingsWhenTrue);
                  try {
                      attribCase.accept(c, caseEnv);
                  } catch (BreakAttr ba) {
                      throw ba;
                  } finally {
                      caseEnv.info.scope.leave();
                  }
                  addVars(c.stats, switchEnv.info.scope);
  
                  c.completesNormally = flow.aliveAfter(caseEnv, c, make);
  
                  prevBindings = c.caseKind == CaseTree.CaseKind.STATEMENT && c.completesNormally ? currentBindings
                                                                                                  : null;
              }
              if (patternSwitch) {
                  chk.checkSwitchCaseStructure(cases);
              }
              if (switchTree.hasTag(SWITCH)) {
                  ((JCSwitch) switchTree).hasTotalPattern = hasDefault || hasTotalPattern;
                  ((JCSwitch) switchTree).patternSwitch = patternSwitch;
              } else if (switchTree.hasTag(SWITCH_EXPRESSION)) {
                  ((JCSwitchExpression) switchTree).hasTotalPattern = hasDefault || hasTotalPattern;
                  ((JCSwitchExpression) switchTree).patternSwitch = patternSwitch;
              } else {
                  Assert.error(switchTree.getTag().name());
              }
          } finally {
              switchEnv.info.scope.leave();
          }
      }
      // where
          /** Add any variables defined in stats to the switch scope. */
          private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
              for (;stats.nonEmpty(); stats = stats.tail) {
                  JCTree stat = stats.head;
                  if (stat.hasTag(VARDEF) && ((JCVariableDecl) stat).sym != null)
                      switchScope.enter(((JCVariableDecl) stat).sym);
              }
          }
          private void checkCaseLabelDominated(DiagnosticPosition pos,
                                               List<Type> coveredTypes, Type patternType) {
              for (Type existing : coveredTypes) {
                  if (types.isSubtype(patternType, existing)) {
                      log.error(pos, Errors.PatternDominated);
                  }
              }
          }
      // where
      /** Return the selected enumeration constant symbol, or null. */
      private Symbol enumConstant(JCTree tree, Type enumType) {
          if (tree.hasTag(IDENT)) {
              JCIdent ident = (JCIdent)tree;
              Name name = ident.name;
              for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
                  if (sym.kind == VAR) {
                      Symbol s = ident.sym = sym;
                      ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
                      ident.type = s.type;
                      return ((s.flags_field & Flags.ENUM) == 0)
                          ? null : s;
                  }
              }
          }
          return null;
      }
  
      public void visitSynchronized(JCSynchronized tree) {
          chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
          if (env.info.lint.isEnabled(LintCategory.SYNCHRONIZATION) && isValueBased(tree.lock.type)) {
              log.warning(LintCategory.SYNCHRONIZATION, tree.pos(), Warnings.AttemptToSynchronizeOnInstanceOfValueBasedClass);
          }
          attribStat(tree.body, env);
          result = null;
      }
          // where
          private boolean isValueBased(Type t) {
              return t != null && t.tsym != null && (t.tsym.flags() & VALUE_BASED) != 0;
          }
  
  
      public void visitTry(JCTry tree) {
          // Create a new local environment with a local
          Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
          try {
              boolean isTryWithResource = tree.resources.nonEmpty();
              // Create a nested environment for attributing the try block if needed
              Env<AttrContext> tryEnv = isTryWithResource ?
                  env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
                  localEnv;
              try {
                  // Attribute resource declarations
                  for (JCTree resource : tree.resources) {
                      CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
                          @Override
                          public void report(DiagnosticPosition pos, JCDiagnostic details) {
                              chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
                          }
                      };
                      ResultInfo twrResult =
                          new ResultInfo(KindSelector.VAR,
                                         syms.autoCloseableType,
                                         twrContext);
                      if (resource.hasTag(VARDEF)) {
                          attribStat(resource, tryEnv);
                          twrResult.check(resource, resource.type);
  
                          //check that resource type cannot throw InterruptedException
                          checkAutoCloseable(resource.pos(), localEnv, resource.type);
  
                          VarSymbol var = ((JCVariableDecl) resource).sym;
                          var.setData(ElementKind.RESOURCE_VARIABLE);
                      } else {
                          attribTree(resource, tryEnv, twrResult);
                      }
                  }
                  // Attribute body
                  attribStat(tree.body, tryEnv);
              } finally {
                  if (isTryWithResource)
                      tryEnv.info.scope.leave();
              }
  
              // Attribute catch clauses
              for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
                  JCCatch c = l.head;
                  Env<AttrContext> catchEnv =
                      localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
                  try {
                      Type ctype = attribStat(c.param, catchEnv);
                      if (TreeInfo.isMultiCatch(c)) {
                          //multi-catch parameter is implicitly marked as final
                          c.param.sym.flags_field |= FINAL | UNION;
                      }
                      if (c.param.sym.kind == VAR) {
                          c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
                      }
                      chk.checkType(c.param.vartype.pos(),
                                    chk.checkClassType(c.param.vartype.pos(), ctype),
                                    syms.throwableType);
                      attribStat(c.body, catchEnv);
                  } finally {
                      catchEnv.info.scope.leave();
                  }
              }
  
              // Attribute finalizer
              if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
              result = null;
          }
          finally {
              localEnv.info.scope.leave();
          }
      }
  
      void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
          if (!resource.isErroneous() &&
              types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
              !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
              Symbol close = syms.noSymbol;
              Log.DiagnosticHandler discardHandler = new Log.DiscardDiagnosticHandler(log);
              try {
                  close = rs.resolveQualifiedMethod(pos,
                          env,
                          types.skipTypeVars(resource, false),
                          names.close,
                          List.nil(),
                          List.nil());
              }
              finally {
                  log.popDiagnosticHandler(discardHandler);
              }
              if (close.kind == MTH &&
                      close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
                      chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) &&
                      env.info.lint.isEnabled(LintCategory.TRY)) {
                  log.warning(LintCategory.TRY, pos, Warnings.TryResourceThrowsInterruptedExc(resource));
              }
          }
      }
  
      public void visitConditional(JCConditional tree) {
          Type condtype = attribExpr(tree.cond, env, syms.booleanType);
          MatchBindings condBindings = matchBindings;
  
          tree.polyKind = (!allowPoly ||
                  pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
                  isBooleanOrNumeric(env, tree)) ?
                  PolyKind.STANDALONE : PolyKind.POLY;
  
          if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
              //this means we are returning a poly conditional from void-compatible lambda expression
              resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
              tree.polyKind = PolyKind.STANDALONE;
          }
  
          ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
                  unknownExprInfo :
                  resultInfo.dup(conditionalContext(resultInfo.checkContext));
  
  
          // x ? y : z
          // include x's bindings when true in y
          // include x's bindings when false in z
  
          Type truetype;
          Env<AttrContext> trueEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
          try {
              truetype = attribTree(tree.truepart, trueEnv, condInfo);
          } finally {
              trueEnv.info.scope.leave();
          }
  
          MatchBindings trueBindings = matchBindings;
  
          Type falsetype;
          Env<AttrContext> falseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
          try {
              falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
          } finally {
              falseEnv.info.scope.leave();
          }
  
          MatchBindings falseBindings = matchBindings;
  
          Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
                  condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
                           List.of(truetype, falsetype)) : pt();
          if (condtype.constValue() != null &&
                  truetype.constValue() != null &&
                  falsetype.constValue() != null &&
                  !owntype.hasTag(NONE)) {
              //constant folding
              owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
          }
          result = check(tree, owntype, KindSelector.VAL, resultInfo);
          matchBindings = matchBindingsComputer.conditional(tree, condBindings, trueBindings, falseBindings);
      }
      //where
          private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
              switch (tree.getTag()) {
                  case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
                                ((JCLiteral)tree).typetag == BOOLEAN ||
                                ((JCLiteral)tree).typetag == BOT;
                  case LAMBDA: case REFERENCE: return false;
                  case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
                  case CONDEXPR:
                      JCConditional condTree = (JCConditional)tree;
                      return isBooleanOrNumeric(env, condTree.truepart) &&
                              isBooleanOrNumeric(env, condTree.falsepart);
                  case APPLY:
                      JCMethodInvocation speculativeMethodTree =
                              (JCMethodInvocation)deferredAttr.attribSpeculative(
                                      tree, env, unknownExprInfo,
                                      argumentAttr.withLocalCacheContext());
                      Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
                      Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
                              env.enclClass.type :
                              ((JCFieldAccess)speculativeMethodTree.meth).selected.type;
                      Type owntype = types.memberType(receiverType, msym).getReturnType();
                      return primitiveOrBoxed(owntype);
                  case NEWCLASS:
                      JCExpression className =
                              removeClassParams.translate(((JCNewClass)tree).clazz);
                      JCExpression speculativeNewClassTree =
                              (JCExpression)deferredAttr.attribSpeculative(
                                      className, env, unknownTypeInfo,
                                      argumentAttr.withLocalCacheContext());
                      return primitiveOrBoxed(speculativeNewClassTree.type);
                  default:
                      Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
                              argumentAttr.withLocalCacheContext()).type;
                      return primitiveOrBoxed(speculativeType);
              }
          }
          //where
              boolean primitiveOrBoxed(Type t) {
                  return (!t.hasTag(TYPEVAR) && !t.isErroneous() && types.unboxedTypeOrType(t).isPrimitive());
              }
  
              TreeTranslator removeClassParams = new TreeTranslator() {
                  @Override
                  public void visitTypeApply(JCTypeApply tree) {
                      result = translate(tree.clazz);
                  }
              };
  
          CheckContext conditionalContext(CheckContext checkContext) {
              return new Check.NestedCheckContext(checkContext) {
                  //this will use enclosing check context to check compatibility of
                  //subexpression against target type; if we are in a method check context,
                  //depending on whether boxing is allowed, we could have incompatibilities
                  @Override
                  public void report(DiagnosticPosition pos, JCDiagnostic details) {
                      enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
                  }
              };
          }
  
          /** Compute the type of a conditional expression, after
           *  checking that it exists.  See JLS 15.25. Does not take into
           *  account the special case where condition and both arms
           *  are constants.
           *
           *  @param pos      The source position to be used for error
           *                  diagnostics.
           *  @param thentype The type of the expression's then-part.
           *  @param elsetype The type of the expression's else-part.
           */
          Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
              if (condTypes.isEmpty()) {
                  return syms.objectType; //TODO: how to handle?
              }
              Type first = condTypes.head;
              // If same type, that is the result
              if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
                  return first.baseType();
  
              List<Type> unboxedTypes = condTypes.stream()
                                                 .map(t -> t.isPrimitive() ? t : types.unboxedType(t))
                                                 .collect(List.collector());
  
              // Otherwise, if both arms can be converted to a numeric
              // type, return the least numeric type that fits both arms
              // (i.e. return larger of the two, or return int if one
              // arm is short, the other is char).
              if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
                  // If one arm has an integer subrange type (i.e., byte,
                  // short, or char), and the other is an integer constant
                  // that fits into the subrange, return the subrange type.
                  for (Type type : unboxedTypes) {
                      if (!type.getTag().isStrictSubRangeOf(INT)) {
                          continue;
                      }
                      if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
                          return type.baseType();
                  }
  
                  for (TypeTag tag : primitiveTags) {
                      Type candidate = syms.typeOfTag[tag.ordinal()];
                      if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
                          return candidate;
                      }
                  }
              }
  
              // Those were all the cases that could result in a primitive
              condTypes = condTypes.stream()
                                   .map(t -> t.isPrimitive() ? types.boxedClass(t).type : t)
                                   .collect(List.collector());
  
              for (Type type : condTypes) {
                  if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
                      return type.baseType();
              }
  
              Iterator<DiagnosticPosition> posIt = positions.iterator();
  
              condTypes = condTypes.stream()
                                   .map(t -> chk.checkNonVoid(posIt.next(), t))
                                   .collect(List.collector());
  
              // both are known to be reference types.  The result is
              // lub(thentype,elsetype). This cannot fail, as it will
              // always be possible to infer "Object" if nothing better.
              return types.lub(condTypes.stream()
                          .map(t -> t.baseType())
                          .filter(t -> !t.hasTag(BOT))
                          .collect(List.collector()));
          }
  
      static final TypeTag[] primitiveTags = new TypeTag[]{
          BYTE,
          CHAR,
          SHORT,
          INT,
          LONG,
          FLOAT,
          DOUBLE,
          BOOLEAN,
      };
  
      Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
          return bindingEnv(env, env.tree, bindings);
      }
  
      Env<AttrContext> bindingEnv(Env<AttrContext> env, JCTree newTree, List<BindingSymbol> bindings) {
          Env<AttrContext> env1 = env.dup(newTree, env.info.dup(env.info.scope.dup()));
          bindings.forEach(env1.info.scope::enter);
          return env1;
      }
  
      public void visitIf(JCIf tree) {
          attribExpr(tree.cond, env, syms.booleanType);
  
          // if (x) { y } [ else z ]
          // include x's bindings when true in y
          // include x's bindings when false in z
  
          MatchBindings condBindings = matchBindings;
          Env<AttrContext> thenEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
  
          try {
              attribStat(tree.thenpart, thenEnv);
          } finally {
              thenEnv.info.scope.leave();
          }
  
          preFlow(tree.thenpart);
          boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
          boolean aliveAfterElse;
  
          if (tree.elsepart != null) {
              Env<AttrContext> elseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
              try {
                  attribStat(tree.elsepart, elseEnv);
              } finally {
                  elseEnv.info.scope.leave();
              }
              preFlow(tree.elsepart);
              aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
          } else {
              aliveAfterElse = true;
          }
  
          chk.checkEmptyIf(tree);
  
          List<BindingSymbol> afterIfBindings = List.nil();
  
          if (aliveAfterThen && !aliveAfterElse) {
              afterIfBindings = condBindings.bindingsWhenTrue;
          } else if (aliveAfterElse && !aliveAfterThen) {
              afterIfBindings = condBindings.bindingsWhenFalse;
          }
  
          afterIfBindings.forEach(env.info.scope::enter);
          afterIfBindings.forEach(BindingSymbol::preserveBinding);
  
          result = null;
      }
  
          void preFlow(JCTree tree) {
              attrRecover.doRecovery();
              new PostAttrAnalyzer() {
                  @Override
                  public void scan(JCTree tree) {
                      if (tree == null ||
                              (tree.type != null &&
                              tree.type == Type.stuckType)) {
                          //don't touch stuck expressions!
                          return;
                      }
                      super.scan(tree);
                  }
  
                  @Override
                  public void visitClassDef(JCClassDecl that) {
                      if (that.sym != null) {
                          // Method preFlow shouldn't visit class definitions
                          // that have not been entered and attributed.
                          // See JDK-8254557 and JDK-8203277 for more details.
                          super.visitClassDef(that);
                      }
                  }
  
                  @Override
                  public void visitLambda(JCLambda that) {
                      if (that.type != null) {
                          // Method preFlow shouldn't visit lambda expressions
                          // that have not been entered and attributed.
                          // See JDK-8254557 and JDK-8203277 for more details.
                          super.visitLambda(that);
                      }
                  }
              }.scan(tree);
          }
  
      public void visitExec(JCExpressionStatement tree) {
          //a fresh environment is required for 292 inference to work properly ---
          //see Infer.instantiatePolymorphicSignatureInstance()
          Env<AttrContext> localEnv = env.dup(tree);
          attribExpr(tree.expr, localEnv);
          result = null;
      }
  
      public void visitBreak(JCBreak tree) {
          tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
          result = null;
      }
  
      public void visitYield(JCYield tree) {
          if (env.info.yieldResult != null) {
              attribTree(tree.value, env, env.info.yieldResult);
              tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
          } else {
              log.error(tree.pos(), tree.value.hasTag(PARENS)
                      ? Errors.NoSwitchExpressionQualify
                      : Errors.NoSwitchExpression);
              attribTree(tree.value, env, unknownExprInfo);
          }
          result = null;
      }
  
      public void visitContinue(JCContinue tree) {
          tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
          result = null;
      }
      //where
          /** Return the target of a break, continue or yield statement,
           *  if it exists, report an error if not.
           *  Note: The target of a labelled break or continue is the
           *  (non-labelled) statement tree referred to by the label,
           *  not the tree representing the labelled statement itself.
           *
           *  @param pos     The position to be used for error diagnostics
           *  @param tag     The tag of the jump statement. This is either
           *                 Tree.BREAK or Tree.CONTINUE.
           *  @param label   The label of the jump statement, or null if no
           *                 label is given.
           *  @param env     The environment current at the jump statement.
           */
          private JCTree findJumpTarget(DiagnosticPosition pos,
                                                     JCTree.Tag tag,
                                                     Name label,
                                                     Env<AttrContext> env) {
              Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
  
              if (jumpTarget.snd != null) {
                  log.error(pos, jumpTarget.snd);
              }
  
              return jumpTarget.fst;
          }
          /** Return the target of a break or continue statement, if it exists,
           *  report an error if not.
           *  Note: The target of a labelled break or continue is the
           *  (non-labelled) statement tree referred to by the label,
           *  not the tree representing the labelled statement itself.
           *
           *  @param tag     The tag of the jump statement. This is either
           *                 Tree.BREAK or Tree.CONTINUE.
           *  @param label   The label of the jump statement, or null if no
           *                 label is given.
           *  @param env     The environment current at the jump statement.
           */
          private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
                                                                         Name label,
                                                                         Env<AttrContext> env) {
              // Search environments outwards from the point of jump.
              Env<AttrContext> env1 = env;
              JCDiagnostic.Error pendingError = null;
              LOOP:
              while (env1 != null) {
                  switch (env1.tree.getTag()) {
                      case LABELLED:
                          JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
                          if (label == labelled.label) {
                              // If jump is a continue, check that target is a loop.
                              if (tag == CONTINUE) {
                                  if (!labelled.body.hasTag(DOLOOP) &&
                                          !labelled.body.hasTag(WHILELOOP) &&
                                          !labelled.body.hasTag(FORLOOP) &&
                                          !labelled.body.hasTag(FOREACHLOOP)) {
                                      pendingError = Errors.NotLoopLabel(label);
                                  }
                                  // Found labelled statement target, now go inwards
                                  // to next non-labelled tree.
                                  return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
                              } else {
                                  return Pair.of(labelled, pendingError);
                              }
                          }
                          break;
                      case DOLOOP:
                      case WHILELOOP:
                      case FORLOOP:
                      case FOREACHLOOP:
                          if (label == null) return Pair.of(env1.tree, pendingError);
                          break;
                      case SWITCH:
                          if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
                          break;
                      case SWITCH_EXPRESSION:
                          if (tag == YIELD) {
                              return Pair.of(env1.tree, null);
                          } else if (tag == BREAK) {
                              pendingError = Errors.BreakOutsideSwitchExpression;
                          } else {
                              pendingError = Errors.ContinueOutsideSwitchExpression;
                          }
                          break;
                      case LAMBDA:
                      case METHODDEF:
                      case CLASSDEF:
                          break LOOP;
                      default:
                  }
                  env1 = env1.next;
              }
              if (label != null)
                  return Pair.of(null, Errors.UndefLabel(label));
              else if (pendingError != null)
                  return Pair.of(null, pendingError);
              else if (tag == CONTINUE)
                  return Pair.of(null, Errors.ContOutsideLoop);
              else
                  return Pair.of(null, Errors.BreakOutsideSwitchLoop);
          }
  
      public void visitReturn(JCReturn tree) {
          // Check that there is an enclosing method which is
          // nested within than the enclosing class.
          if (env.info.returnResult == null) {
              log.error(tree.pos(), Errors.RetOutsideMeth);
          } else if (env.info.yieldResult != null) {
              log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
          } else if (!env.info.isLambda &&
                  !env.info.isNewClass &&
                  env.enclMethod != null &&
                  TreeInfo.isCompactConstructor(env.enclMethod)) {
              log.error(env.enclMethod,
                      Errors.InvalidCanonicalConstructorInRecord(Fragments.Compact, env.enclMethod.sym.name, Fragments.CanonicalCantHaveReturnStatement));
          } else {
              // Attribute return expression, if it exists, and check that
              // it conforms to result type of enclosing method.
              if (tree.expr != null) {
                  if (env.info.returnResult.pt.hasTag(VOID)) {
                      env.info.returnResult.checkContext.report(tree.expr.pos(),
                                diags.fragment(Fragments.UnexpectedRetVal));
                  }
                  attribTree(tree.expr, env, env.info.returnResult);
              } else if (!env.info.returnResult.pt.hasTag(VOID) &&
                      !env.info.returnResult.pt.hasTag(NONE)) {
                  env.info.returnResult.checkContext.report(tree.pos(),
                                diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
              }
          }
          result = null;
      }
  
      public void visitThrow(JCThrow tree) {
          Type owntype = attribExpr(tree.expr, env, allowPoly ? Type.noType : syms.throwableType);
          if (allowPoly) {
              chk.checkType(tree, owntype, syms.throwableType);
          }
          result = null;
      }
  
      public void visitAssert(JCAssert tree) {
          attribExpr(tree.cond, env, syms.booleanType);
          if (tree.detail != null) {
              chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
          }
          result = null;
      }
  
       /** Visitor method for method invocations.
       *  NOTE: The method part of an application will have in its type field
       *        the return type of the method, not the method's type itself!
       */
      public void visitApply(JCMethodInvocation tree) {
          // The local environment of a method application is
          // a new environment nested in the current one.
          Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
  
          // The types of the actual method arguments.
          List<Type> argtypes = null;
  
          // The types of the actual method type arguments.
          List<Type> typeargtypes = null;
  
          Name methName = TreeInfo.name(tree.meth);
  
          boolean isConstructorCall =
              methName == names._this || methName == names._super;
  
          ListBuffer<Type> argtypesBuf = new ListBuffer<>();
          if (isConstructorCall) {
              // We are seeing a ...this(...) or ...super(...) call.
              // Check that this is the first statement in a constructor.
              checkFirstConstructorStat(tree, env.enclMethod, true);
  
              // Record the fact
              // that this is a constructor call (using isSelfCall).
              localEnv.info.isSelfCall = true;
  
              // Attribute arguments, yielding list of argument types.
              KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
              argtypes = argtypesBuf.toList();
              typeargtypes = attribTypes(tree.typeargs, localEnv);
  
              // Variable `site' points to the class in which the called
              // constructor is defined.
              Type site = env.enclClass.sym.type;
              if (methName == names._super) {
                  if (site == syms.objectType) {
                      log.error(tree.meth.pos(), Errors.NoSuperclass(site));
                      site = types.createErrorType(syms.objectType);
                  } else {
                      site = types.supertype(site);
                  }
              }
  
              if (site.hasTag(CLASS) || site.hasTag(ERROR)) {
                  Type encl = site.getEnclosingType();
                  while (encl != null && encl.hasTag(TYPEVAR))
                      encl = encl.getUpperBound();
                  if (encl.hasTag(CLASS)) {
                      // we are calling a nested class
  
                      if (tree.meth.hasTag(SELECT)) {
                          JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
  
                          // We are seeing a prefixed call, of the form
                          //     <expr>.super(...).
                          // Check that the prefix expression conforms
                          // to the outer instance type of the class.
                          chk.checkRefType(qualifier.pos(),
                                           attribExpr(qualifier, localEnv,
                                                      encl));
                      } else if (methName == names._super) {
                          // qualifier omitted; check for existence
                          // of an appropriate implicit qualifier.
                          rs.resolveImplicitThis(tree.meth.pos(),
                                                 localEnv, site, true);
                      }
                  } else if (tree.meth.hasTag(SELECT)) {
                      log.error(tree.meth.pos(),
                                Errors.IllegalQualNotIcls(site.tsym));
                      attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
                  }
  
                  // if we're calling a java.lang.Enum constructor,
                  // prefix the implicit String and int parameters
                  if (site.tsym == syms.enumSym)
                      argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
  
                  // Resolve the called constructor under the assumption
                  // that we are referring to a superclass instance of the
                  // current instance (JLS ???).
                  boolean selectSuperPrev = localEnv.info.selectSuper;
                  localEnv.info.selectSuper = true;
                  localEnv.info.pendingResolutionPhase = null;
                  Symbol sym = rs.resolveConstructor(
                      tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
                  localEnv.info.selectSuper = selectSuperPrev;
  
                  // Set method symbol to resolved constructor...
                  TreeInfo.setSymbol(tree.meth, sym);
  
                  // ...and check that it is legal in the current context.
                  // (this will also set the tree's type)
                  Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
                  checkId(tree.meth, site, sym, localEnv,
                          new ResultInfo(kind, mpt));
              } else if (site.hasTag(ERROR) && tree.meth.hasTag(SELECT)) {
                  attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
              }
              // Otherwise, `site' is an error type and we do nothing
              result = tree.type = syms.voidType;
          } else {
              // Otherwise, we are seeing a regular method call.
              // Attribute the arguments, yielding list of argument types, ...
              KindSelector kind;
              try {
                  kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
              } catch (BreakAttr bae) {
                  argtypes = argtypesBuf.toList();
                  typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
                  Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
                  localEnv.info.pendingResolutionPhase = null;
                  attribTree(tree.meth, localEnv, new ResultInfo(KindSelector.VAL_POLY, mpt, resultInfo.checkContext));
                  throw bae;
              }
              argtypes = argtypesBuf.toList();
              typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
  
              // ... and attribute the method using as a prototype a methodtype
              // whose formal argument types is exactly the list of actual
              // arguments (this will also set the method symbol).
              Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
              localEnv.info.pendingResolutionPhase = null;
              Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
  
              // Compute the result type.
              Type restype = mtype.getReturnType();
              if (restype.hasTag(WILDCARD))
                  throw new AssertionError(mtype);
  
              Type qualifier = (tree.meth.hasTag(SELECT))
                      ? ((JCFieldAccess) tree.meth).selected.type
                      : env.enclClass.sym.type;
              Symbol msym = TreeInfo.symbol(tree.meth);
              restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
  
              chk.checkRefTypes(tree.typeargs, typeargtypes);
  
              // Check that value of resulting type is admissible in the
              // current context.  Also, capture the return type
              Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
              result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
          }
          chk.validate(tree.typeargs, localEnv);
      }
      //where
          Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
              if (msym != null &&
                      msym.owner == syms.objectType.tsym &&
                      methodName == names.getClass &&
                      argtypes.isEmpty()) {
                  // as a special case, x.getClass() has type Class<? extends |X|>
                  return new ClassType(restype.getEnclosingType(),
                          List.of(new WildcardType(types.erasure(qualifierType),
                                  BoundKind.EXTENDS,
                                  syms.boundClass)),
                          restype.tsym,
                          restype.getMetadata());
              } else if (msym != null &&
                      msym.owner == syms.arrayClass &&
                      methodName == names.clone &&
                      types.isArray(qualifierType)) {
                  // as a special case, array.clone() has a result that is
                  // the same as static type of the array being cloned
                  return qualifierType;
              } else {
                  return restype;
              }
          }
  
          /** Check that given application node appears as first statement
           *  in a constructor call.
           *  @param tree          The application node
           *  @param enclMethod    The enclosing method of the application.
           *  @param error         Should an error be issued?
           */
          boolean checkFirstConstructorStat(JCMethodInvocation tree, JCMethodDecl enclMethod, boolean error) {
              if (enclMethod != null && enclMethod.name == names.init) {
                  JCBlock body = enclMethod.body;
                  if (body.stats.head.hasTag(EXEC) &&
                      ((JCExpressionStatement) body.stats.head).expr == tree)
                      return true;
              }
              if (error) {
                  log.error(tree.pos(),
                          Errors.CallMustBeFirstStmtInCtor(TreeInfo.name(tree.meth)));
              }
              return false;
          }
  
          /** Obtain a method type with given argument types.
           */
          Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
              MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
              return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
          }
  
      public void visitNewClass(final JCNewClass tree) {
          Type owntype = types.createErrorType(tree.type);
  
          // The local environment of a class creation is
          // a new environment nested in the current one.
          Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
  
          // The anonymous inner class definition of the new expression,
          // if one is defined by it.
          JCClassDecl cdef = tree.def;
  
          // If enclosing class is given, attribute it, and
          // complete class name to be fully qualified
          JCExpression clazz = tree.clazz; // Class field following new
          JCExpression clazzid;            // Identifier in class field
          JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
          annoclazzid = null;
  
          if (clazz.hasTag(TYPEAPPLY)) {
              clazzid = ((JCTypeApply) clazz).clazz;
              if (clazzid.hasTag(ANNOTATED_TYPE)) {
                  annoclazzid = (JCAnnotatedType) clazzid;
                  clazzid = annoclazzid.underlyingType;
              }
          } else {
              if (clazz.hasTag(ANNOTATED_TYPE)) {
                  annoclazzid = (JCAnnotatedType) clazz;
                  clazzid = annoclazzid.underlyingType;
              } else {
                  clazzid = clazz;
              }
          }
  
          JCExpression clazzid1 = clazzid; // The same in fully qualified form
  
          if (tree.encl != null) {
              // We are seeing a qualified new, of the form
              //    <expr>.new C <...> (...) ...
              // In this case, we let clazz stand for the name of the
              // allocated class C prefixed with the type of the qualifier
              // expression, so that we can
              // resolve it with standard techniques later. I.e., if
              // <expr> has type T, then <expr>.new C <...> (...)
              // yields a clazz T.C.
              Type encltype = chk.checkRefType(tree.encl.pos(),
                                               attribExpr(tree.encl, env));
              // TODO 308: in <expr>.new C, do we also want to add the type annotations
              // from expr to the combined type, or not? Yes, do this.
              clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
                                                   ((JCIdent) clazzid).name);
  
              EndPosTable endPosTable = this.env.toplevel.endPositions;
              endPosTable.storeEnd(clazzid1, clazzid.getEndPosition(endPosTable));
              if (clazz.hasTag(ANNOTATED_TYPE)) {
                  JCAnnotatedType annoType = (JCAnnotatedType) clazz;
                  List<JCAnnotation> annos = annoType.annotations;
  
                  if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
                      clazzid1 = make.at(tree.pos).
                          TypeApply(clazzid1,
                                    ((JCTypeApply) clazz).arguments);
                  }
  
                  clazzid1 = make.at(tree.pos).
                      AnnotatedType(annos, clazzid1);
              } else if (clazz.hasTag(TYPEAPPLY)) {
                  clazzid1 = make.at(tree.pos).
                      TypeApply(clazzid1,
                                ((JCTypeApply) clazz).arguments);
              }
  
              clazz = clazzid1;
          }
  
          // Attribute clazz expression and store
          // symbol + type back into the attributed tree.
          Type clazztype;
  
          try {
              env.info.isNewClass = true;
              clazztype = TreeInfo.isEnumInit(env.tree) ?
                  attribIdentAsEnumType(env, (JCIdent)clazz) :
                  attribType(clazz, env);
          } finally {
              env.info.isNewClass = false;
          }
  
          clazztype = chk.checkDiamond(tree, clazztype);
          chk.validate(clazz, localEnv);
          if (tree.encl != null) {
              // We have to work in this case to store
              // symbol + type back into the attributed tree.
              tree.clazz.type = clazztype;
              TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
              clazzid.type = ((JCIdent) clazzid).sym.type;
              if (annoclazzid != null) {
                  annoclazzid.type = clazzid.type;
              }
              if (!clazztype.isErroneous()) {
                  if (cdef != null && clazztype.tsym.isInterface()) {
                      log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
                  } else if (clazztype.tsym.isStatic()) {
                      log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
                  }
              }
          } else if (!clazztype.tsym.isInterface() &&
                     clazztype.getEnclosingType().hasTag(CLASS)) {
              // Check for the existence of an apropos outer instance
              rs.resolveImplicitThis(tree.pos(), env, clazztype);
          }
  
          // Attribute constructor arguments.
          ListBuffer<Type> argtypesBuf = new ListBuffer<>();
          final KindSelector pkind =
              attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
          List<Type> argtypes = argtypesBuf.toList();
          List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
  
          boolean wasError = clazztype.hasTag(ERROR);
          if (clazztype.hasTag(CLASS) || wasError) {
              // Enums may not be instantiated except implicitly
              if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
                  (!env.tree.hasTag(VARDEF) ||
                   (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
                   ((JCVariableDecl) env.tree).init != tree))
                  log.error(tree.pos(), Errors.EnumCantBeInstantiated);
  
              boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
                      resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
              boolean skipNonDiamondPath = false;
              // Check that class is not abstract
              if (cdef == null && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
                  (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
                  log.error(tree.pos(),
                            Errors.AbstractCantBeInstantiated(clazztype.tsym));
                  skipNonDiamondPath = true;
              } else if (cdef != null && clazztype.tsym.isInterface()) {
                  // Check that no constructor arguments are given to
                  // anonymous classes implementing an interface
                  if (!argtypes.isEmpty())
                      log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
  
                  if (!typeargtypes.isEmpty())
                      log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
  
                  // Error recovery: pretend no arguments were supplied.
                  argtypes = List.nil();
                  typeargtypes = List.nil();
                  skipNonDiamondPath = true;
              }
              if (TreeInfo.isDiamond(tree) && !wasError) {
                  ClassType site = new ClassType(clazztype.getEnclosingType(),
                              clazztype.tsym.type.getTypeArguments(),
                                                 clazztype.tsym,
                                                 clazztype.getMetadata());
  
                  Env<AttrContext> diamondEnv = localEnv.dup(tree);
                  diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
                  diamondEnv.info.pendingResolutionPhase = null;
  
                  //if the type of the instance creation expression is a class type
                  //apply method resolution inference (JLS 15.12.2.7). The return type
                  //of the resolved constructor will be a partially instantiated type
                  Symbol constructor = rs.resolveDiamond(tree.pos(),
                              diamondEnv,
                              site,
                              argtypes,
                              typeargtypes);
                  tree.constructor = constructor.baseSymbol();
  
                  final TypeSymbol csym = clazztype.tsym;
                  ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
                          diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
                  Type constructorType = tree.constructorType = types.createErrorType(clazztype);
                  constructorType = checkId(tree, site,
                          constructor,
                          diamondEnv,
                          diamondResult);
  
                  tree.clazz.type = types.createErrorType(clazztype);
                  if (!constructorType.isErroneous()) {
                      tree.clazz.type = clazz.type = constructorType.getReturnType();
                      tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
                  } else if (errArgs(tree.args)) {
                      Symbol s = null;
                      for (Symbol sym : site.tsym.members().getSymbolsByName(names.init)) {
                          if (s == null || sym.asType().getParameterTypes().isEmpty())
                              s = sym;
                      }
                      if (s != null) {
                          List<Type> atypes = s.asType().getParameterTypes();
                          constructor = rs.resolveDiamond(tree.pos(),
                              diamondEnv,
                              site,
                              atypes,
                              typeargtypes);
                          diamondResult = new ResultInfo(KindSelector.MTH, newMethodTemplate(resultInfo.pt, atypes, typeargtypes), new Check.NestedCheckContext(resultInfo.checkContext) {
                              @Override
                              public void report(DiagnosticPosition _unused, JCDiagnostic details) {
                              }
                          });
                          constructorType = checkId(tree, site,
                                  constructor,
                                  diamondEnv,
                                  diamondResult);
                          if (!constructorType.isErroneous())
                              tree.clazz.type = constructorType.getReturnType();
                      }
                  }
                  clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
              }
  
              // Resolve the called constructor under the assumption
              // that we are referring to a superclass instance of the
              // current instance (JLS ???).
              else if (!skipNonDiamondPath) {
                  //the following code alters some of the fields in the current
                  //AttrContext - hence, the current context must be dup'ed in
                  //order to avoid downstream failures
                  Env<AttrContext> rsEnv = localEnv.dup(tree);
                  rsEnv.info.selectSuper = cdef != null;
                  rsEnv.info.pendingResolutionPhase = null;
                  tree.constructor = rs.resolveConstructor(
                      tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
                  if (cdef == null) { //do not check twice!
                      tree.constructorType = checkId(tree,
                              clazztype,
                              tree.constructor,
                              rsEnv,
                              new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
                      if (rsEnv.info.lastResolveVarargs())
                          Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
                      Env<AttrContext> enclosing;
                      if (tree.constructor.kind == MTH && tree.constructor.type.isErroneous() && ((enclosing = enter.getEnv(tree.constructor.enclClass())) == null || enclosing.toplevel != env.toplevel)) {
                          log.error(tree.pos, "type.error", tree.constructor);
                      }
                  }
              }
  
              if (cdef != null) {
                  visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
                  return;
              }
  
              if (tree.constructor != null && tree.constructor.kind == MTH)
                  owntype = wasError ? types.createErrorType(clazztype) : clazztype;
          }
          result = check(tree, owntype, KindSelector.VAL, resultInfo);
          InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
          if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
              //we need to wait for inference to finish and then replace inference vars in the constructor type
              inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
                      instantiatedContext -> {
                          tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
                      });
          }
          chk.validate(tree.typeargs, localEnv);
      }
      //where
      private boolean errArgs(List<JCExpression> args) {
          for (JCExpression arg : args) {
              if (arg.hasTag(Tag.ERRONEOUS))
                  return true;
          }
          return false;
      }
  
          // where
          private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
                                                     JCClassDecl cdef, Env<AttrContext> localEnv,
                                                     List<Type> argtypes, List<Type> typeargtypes,
                                                     KindSelector pkind) {
              // We are seeing an anonymous class instance creation.
              // In this case, the class instance creation
              // expression
              //
              //    E.new <typeargs1>C<typargs2>(args) { ... }
              //
              // is represented internally as
              //
              //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
              //
              // This expression is then *transformed* as follows:
              //
              // (1) add an extends or implements clause
              // (2) add a constructor.
              //
              // For instance, if C is a class, and ET is the type of E,
              // the expression
              //
              //    E.new <typeargs1>C<typargs2>(args) { ... }
              //
              // is translated to (where X is a fresh name and typarams is the
              // parameter list of the super constructor):
              //
              //   new <typeargs1>X(<*nullchk*>E, args) where
              //     X extends C<typargs2> {
              //       <typarams> X(ET e, args) {
              //         e.<typeargs1>super(args)
              //       }
              //       ...
              //     }
              InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
              final boolean isDiamond = TreeInfo.isDiamond(tree);
              if (isDiamond
                      && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
                      || (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
                  final ResultInfo resultInfoForClassDefinition = this.resultInfo;
                  inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
                          instantiatedContext -> {
                              tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
                              tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
                              ResultInfo prevResult = this.resultInfo;
                              try {
                                  this.resultInfo = resultInfoForClassDefinition;
                                  visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
                                                              localEnv, argtypes, typeargtypes, pkind);
                              } finally {
                                  this.resultInfo = prevResult;
                              }
                          });
              } else {
                  if (isDiamond && clazztype.hasTag(CLASS)) {
                      List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
                      if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
                          // One or more types inferred in the previous steps is non-denotable.
                          Fragment fragment = Diamond(clazztype.tsym);
                          log.error(tree.clazz.pos(),
                                  Errors.CantApplyDiamond1(
                                          fragment,
                                          invalidDiamondArgs.size() > 1 ?
                                                  DiamondInvalidArgs(invalidDiamondArgs, fragment) :
                                                  DiamondInvalidArg(invalidDiamondArgs, fragment)));
                      }
                      // For <>(){}, inferred types must also be accessible.
                      for (Type t : clazztype.getTypeArguments()) {
                          rs.checkAccessibleType(env, t);
                      }
                  }
  
                  // If we already errored, be careful to avoid a further avalanche. ErrorType answers
                  // false for isInterface call even when the original type is an interface.
                  boolean implementing = clazztype.tsym.isInterface() ||
                          clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
                          clazztype.getOriginalType().tsym.isInterface();
  
                  if (implementing) {
                      cdef.implementing = List.of(clazz);
                  } else {
                      cdef.extending = clazz;
                  }
  
                  if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
                      isSerializable(clazztype)) {
                      localEnv.info.isSerializable = true;
                  }
  
                  attribStat(cdef, localEnv);
  
                  JCExpression clazzCopy = new TreeCopier<JCTree>(make) {
                      @Override
                      public <T extends JCTree> T copy(T tree, JCTree p) {
                          T t = super.copy(tree, p);
                          if (t != null) {
                              t.pos = Position.NOPOS;
                              t.type = tree.type;
                          }
                          return t;
                      }
  
                      @Override public JCTree visitIdentifier(IdentifierTree node, JCTree p) {
                          JCIdent result = (JCIdent) super.visitIdentifier(node, p);
  
                          result.sym = ((JCIdent) node).sym;
  
                          return result;
                      }
  
                      @Override public JCTree visitMemberSelect(MemberSelectTree node, JCTree p) {
                          JCFieldAccess result = (JCFieldAccess) super.visitMemberSelect(node, p);
  
                          result.sym = ((JCFieldAccess) node).sym;
  
                          return result;
                      }
                  }.copy(clazz);
                  if (clazztype.tsym.isInterface()) {
                      cdef.implementing = List.of(clazzCopy);
                  } else {
                      cdef.extending = clazzCopy;
                  }
  
                  List<Type> finalargtypes;
                  // If an outer instance is given,
                  // prefix it to the constructor arguments
                  // "encl" will be cleared in TransTypes
                  if (tree.encl != null && !clazztype.tsym.isInterface()) {
                      finalargtypes = argtypes.prepend(tree.encl.type);
                  } else {
                      finalargtypes = argtypes;
                  }
  
                  // Reassign clazztype and recompute constructor. As this necessarily involves
                  // another attribution pass for deferred types in the case of <>, replicate
                  // them. Original arguments have right decorations already.
                  if (isDiamond && pkind.contains(KindSelector.POLY)) {
                      finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
                  }
  
                  clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
                                                      : cdef.sym.type;
                  Symbol sym = tree.constructor = rs.resolveConstructor(
                          tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
                  Assert.check(!sym.kind.isResolutionError());
                  tree.constructor = sym;
                  tree.constructorType = checkId(tree,
                          clazztype,
                          tree.constructor,
                          localEnv,
                          new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
              }
              Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
                                  clazztype : types.createErrorType(tree.type);
              result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
              chk.validate(tree.typeargs, localEnv);
          }
  
          CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
              return new Check.NestedCheckContext(checkContext) {
                  @Override
                  public void report(DiagnosticPosition _unused, JCDiagnostic details) {
                      enclosingContext.report(clazz.clazz,
                              diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
                  }
              };
          }
  
      /** Make an attributed null check tree.
       */
      public JCExpression makeNullCheck(JCExpression arg) {
          // optimization: new Outer() can never be null; skip null check
          if (arg.getTag() == NEWCLASS)
              return arg;
          // optimization: X.this is never null; skip null check
          Name name = TreeInfo.name(arg);
          if (name == names._this || name == names._super) return arg;
  
          JCTree.Tag optag = NULLCHK;
          JCUnary tree = make.at(Position.NOPOS).Unary(optag, arg);
          tree.operator = operators.resolveUnary(arg, optag, arg.type);
          tree.type = arg.type;
          return tree;
      }
  
      public void visitNewArray(JCNewArray tree) {
          Type owntype = types.createErrorType(tree.type);
          Env<AttrContext> localEnv = env.dup(tree);
          Type elemtype;
          if (tree.elemtype != null) {
              elemtype = attribType(tree.elemtype, localEnv);
              chk.validate(tree.elemtype, localEnv);
              owntype = elemtype;
              for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
                  attribExpr(l.head, localEnv, syms.intType);
                  owntype = new ArrayType(owntype, syms.arrayClass);
              }
          } else {
              // we are seeing an untyped aggregate { ... }
              // this is allowed only if the prototype is an array
              if (pt().hasTag(ARRAY)) {
                  elemtype = types.elemtype(pt());
              } else {
                  if (!pt().hasTag(ERROR) &&
                          (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
                      log.error(tree.pos(),
                                Errors.IllegalInitializerForType(pt()));
                  }
                  elemtype = types.createErrorType(pt());
              }
          }
          if (tree.elems != null) {
              attribExprs(tree.elems, localEnv, elemtype);
              owntype = new ArrayType(elemtype, syms.arrayClass);
          }
          if (!types.isReifiable(elemtype))
              log.error(tree.pos(), Errors.GenericArrayCreation);
          result = check(tree, owntype, KindSelector.VAL, resultInfo);
      }
  
      /*
       * A lambda expression can only be attributed when a target-type is available.
       * In addition, if the target-type is that of a functional interface whose
       * descriptor contains inference variables in argument position the lambda expression
       * is 'stuck' (see DeferredAttr).
       */
      @Override
      public void visitLambda(final JCLambda that) {
          boolean wrongContext = false;
          if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
              if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
                  //lambda only allowed in assignment or method invocation/cast context
                  log.error(that.pos(), Errors.UnexpectedLambda);
              }
              resultInfo = recoveryInfo;
              wrongContext = true;
          }
          //create an environment for attribution of the lambda expression
          final Env<AttrContext> localEnv = lambdaEnv(that, env);
          boolean needsRecovery = resultInfo != recoveryInfo &&
                  resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
          Type currentTarget = null;
          try {
              if (needsRecovery && isSerializable(pt())) {
                  localEnv.info.isSerializable = true;
                  localEnv.info.isSerializableLambda = true;
              }
              List<Type> explicitParamTypes = null;
              if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
                  //attribute lambda parameters
                  attribStats(that.params, localEnv);
                  explicitParamTypes = TreeInfo.types(that.params);
              }
  
              if (pt().hasTag(NONE) && pt() != Type.recoveryType) {
                  resultInfo = recoveryInfo;
              }
              TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
              currentTarget = targetInfo.target;
              Type lambdaType = targetInfo.descriptor;
  
              if (currentTarget.isErroneous()) {
                  result = that.type = currentTarget;
                  return;
              }
  
              setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
  
              if (lambdaType.hasTag(FORALL)) {
                  //lambda expression target desc cannot be a generic method
                  Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
                                                                      kindName(currentTarget.tsym),
                                                                      currentTarget.tsym);
                  resultInfo.checkContext.report(that, diags.fragment(msg));
                  result = that.type = types.createErrorType(pt());
                  return;
              }
  
              if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
                  //add param type info in the AST
                  List<Type> actuals = lambdaType.getParameterTypes();
                  List<JCVariableDecl> params = that.params;
  
                  boolean arityMismatch = false;
  
                  while (params.nonEmpty()) {
                      if (actuals.isEmpty()) {
                          //not enough actuals to perform lambda parameter inference
                          arityMismatch = true;
                      }
                      //reset previously set info
                      Type argType = arityMismatch ?
                              syms.errType :
                              actuals.head;
                      if (params.head.isImplicitlyTyped()) {
                          setSyntheticVariableType(params.head, argType);
                      }
                      params.head.sym = null;
                      actuals = actuals.isEmpty() ?
                              actuals :
                              actuals.tail;
                      params = params.tail;
                  }
  
                  //attribute lambda parameters
                  attribStats(that.params, localEnv);
  
                  if (arityMismatch) {
                      resultInfo.checkContext.report(that, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
                          result = that.type = types.createErrorType(currentTarget);
                          return;
                  }
              }
  
              //from this point on, no recovery is needed; if we are in assignment context
              //we will be able to attribute the whole lambda body, regardless of errors;
              //if we are in a 'check' method context, and the lambda is not compatible
              //with the target-type, it will be recovered anyway in Attr.checkId
              needsRecovery = false;
  
              ResultInfo bodyResultInfo = localEnv.info.returnResult =
                      lambdaBodyResult(that, lambdaType, resultInfo);
  
              if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
                  attribTree(that.getBody(), localEnv, bodyResultInfo);
              } else {
                  JCBlock body = (JCBlock)that.body;
                  if (body == breakTree &&
                          resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
                      breakTreeFound(copyEnv(localEnv), null);
                  }
                  attribStats(body.stats, localEnv);
              }
  
              result = check(that, currentTarget, KindSelector.VAL, resultInfo);
  
              boolean isSpeculativeRound =
                      resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
  
              preFlow(that);
              flow.analyzeLambda(env, that, make, isSpeculativeRound);
  
              that.type = currentTarget; //avoids recovery at this stage
              checkLambdaCompatible(that, lambdaType, resultInfo.checkContext);
  
              if (!isSpeculativeRound) {
                  //add thrown types as bounds to the thrown types free variables if needed:
                  if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
                      List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
                      if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
                          log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
                      }
                  }
  
                  checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
              }
              result = wrongContext ? that.type = types.createErrorType(pt())
                                    : check(that, currentTarget, KindSelector.VAL, resultInfo);
          } catch (Types.FunctionDescriptorLookupError ex) {
              JCDiagnostic cause = ex.getDiagnostic();
              resultInfo.checkContext.report(that, cause);
              result = that.type = types.createErrorType(pt());
              return;
          } catch (BreakAttr ba) {
              if (currentTarget != null) {
                  check(that, currentTarget, KindSelector.VAL, resultInfo);
              }
              needsRecovery = false;
              throw ba;
          } catch (CompletionFailure cf) {
              chk.completionError(that.pos(), cf);
          } catch (Throwable t) {
              //when an unexpected exception happens, avoid attempts to attribute the same tree again
              //as that would likely cause the same exception again.
              needsRecovery = false;
              throw t;
          } finally {
              localEnv.info.scope.leave();
              if (needsRecovery) {
                  Type prevResult = result;
                  try {
                      attribTree(that, env, recoveryInfo);
                  } finally {
                      if (result == Type.recoveryType) {
                          result = prevResult;
                      }
                  }
              }
          }
      }
      //where
          class TargetInfo {
              Type target;
              Type descriptor;
  
              public TargetInfo(Type target, Type descriptor) {
                  this.target = target;
                  this.descriptor = descriptor;
              }
          }
  
          TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
              Type lambdaType;
              Type currentTarget = resultInfo.pt;
              if (resultInfo.pt != Type.recoveryType) {
                  /* We need to adjust the target. If the target is an
                   * intersection type, for example: SAM & I1 & I2 ...
                   * the target will be updated to SAM
                   */
                  currentTarget = targetChecker.visit(currentTarget, that);
                  if (!currentTarget.isIntersection()) {
                      if (explicitParamTypes != null) {
                          currentTarget = infer.instantiateFunctionalInterface(that,
                                  currentTarget, explicitParamTypes, resultInfo.checkContext);
                      }
                      currentTarget = types.removeWildcards(currentTarget);
                      lambdaType = types.findDescriptorType(currentTarget);
                  } else {
                      IntersectionClassType ict = (IntersectionClassType)currentTarget;
                      ListBuffer<Type> components = new ListBuffer<>();
                      for (Type bound : ict.getExplicitComponents()) {
                          if (explicitParamTypes != null) {
                              try {
                                  bound = infer.instantiateFunctionalInterface(that,
                                          bound, explicitParamTypes, resultInfo.checkContext);
                              } catch (FunctionDescriptorLookupError t) {
                                  // do nothing
                              }
                          }
                          bound = types.removeWildcards(bound);
                          components.add(bound);
                      }
                      currentTarget = types.makeIntersectionType(components.toList());
                      currentTarget.tsym.flags_field |= INTERFACE;
                      lambdaType = types.findDescriptorType(currentTarget);
                  }
  
              } else {
                  currentTarget = Type.recoveryType;
                  lambdaType = fallbackDescriptorType(that);
              }
              if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
                  //lambda expression target desc cannot be a generic method
                  Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
                                                                      kindName(currentTarget.tsym),
                                                                      currentTarget.tsym);
                  resultInfo.checkContext.report(that, diags.fragment(msg));
                  currentTarget = types.createErrorType(pt());
              }
              return new TargetInfo(currentTarget, lambdaType);
          }
  
          void preFlow(JCLambda tree) {
              attrRecover.doRecovery();
              new PostAttrAnalyzer() {
                  @Override
                  public void scan(JCTree tree) {
                      if (tree == null ||
                              (tree.type != null &&
                              tree.type == Type.stuckType)) {
                          //don't touch stuck expressions!
                          return;
                      }
                      super.scan(tree);
                  }
  
                  @Override
                  public void visitClassDef(JCClassDecl that) {
                      // or class declaration trees!
                  }
  
                  public void visitLambda(JCLambda that) {
                      // or lambda expressions!
                  }
              }.scan(tree.body);
          }
  
          Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
  
              @Override
              public Type visitClassType(ClassType t, DiagnosticPosition pos) {
                  return t.isIntersection() ?
                          visitIntersectionClassType((IntersectionClassType)t, pos) : t;
              }
  
              public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
                  types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
                  return ict;
              }
  
              private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
                  ListBuffer<Type> targs = new ListBuffer<>();
                  ListBuffer<Type> supertypes = new ListBuffer<>();
                  for (Type i : ict.interfaces_field) {
                      if (i.isParameterized()) {
                          targs.appendList(i.tsym.type.allparams());
                      }
                      supertypes.append(i.tsym.type);
                  }
                  IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
                  notionalIntf.allparams_field = targs.toList();
                  notionalIntf.tsym.flags_field |= INTERFACE;
                  return notionalIntf.tsym;
              }
          };
  
          private Type fallbackDescriptorType(JCExpression tree) {
              switch (tree.getTag()) {
                  case LAMBDA:
                      JCLambda lambda = (JCLambda)tree;
                      List<Type> argtypes = List.nil();
                      for (JCVariableDecl param : lambda.params) {
                          argtypes = param.vartype != null && param.vartype.type != null ?
                                  argtypes.append(param.vartype.type) :
                                  argtypes.append(syms.errType);
                      }
                      return new MethodType(argtypes, Type.recoveryType,
                              List.of(syms.throwableType), syms.methodClass);
                  case REFERENCE:
                      return new MethodType(List.nil(), Type.recoveryType,
                              List.of(syms.throwableType), syms.methodClass);
                  default:
                      Assert.error("Cannot get here!");
              }
              return null;
          }
  
          private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
                  final InferenceContext inferenceContext, final Type... ts) {
              checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
          }
  
          private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
                  final InferenceContext inferenceContext, final List<Type> ts) {
              if (inferenceContext.free(ts)) {
                  inferenceContext.addFreeTypeListener(ts,
                          solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
              } else {
                  for (Type t : ts) {
                      rs.checkAccessibleType(env, t);
                  }
              }
          }
  
          /**
           * Lambda/method reference have a special check context that ensures
           * that i.e. a lambda return type is compatible with the expected
           * type according to both the inherited context and the assignment
           * context.
           */
          class FunctionalReturnContext extends Check.NestedCheckContext {
  
              FunctionalReturnContext(CheckContext enclosingContext) {
                  super(enclosingContext);
              }
  
              @Override
              public boolean compatible(Type found, Type req, Warner warn) {
                  //return type must be compatible in both current context and assignment context
                  return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
              }
  
              @Override
              public void report(DiagnosticPosition pos, JCDiagnostic details) {
                  enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
              }
          }
  
          class ExpressionLambdaReturnContext extends FunctionalReturnContext {
  
              JCExpression expr;
              boolean expStmtExpected;
  
              ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
                  super(enclosingContext);
                  this.expr = expr;
              }
  
              @Override
              public void report(DiagnosticPosition pos, JCDiagnostic details) {
                  if (expStmtExpected) {
                      enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
                  } else {
                      super.report(pos, details);
                  }
              }
  
              @Override
              public boolean compatible(Type found, Type req, Warner warn) {
                  //a void return is compatible with an expression statement lambda
                  if (req.hasTag(VOID)) {
                      expStmtExpected = true;
                      return TreeInfo.isExpressionStatement(expr, names);
                  } else {
                      return super.compatible(found, req, warn);
                  }
              }
          }
  
          ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
              FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
                      new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
                      new FunctionalReturnContext(resultInfo.checkContext);
  
              return descriptor.getReturnType() == Type.recoveryType ?
                      recoveryInfo :
                      new ResultInfo(KindSelector.VAL,
                              descriptor.getReturnType(), funcContext);
          }
  
          /**
          * Lambda compatibility. Check that given return types, thrown types, parameter types
          * are compatible with the expected functional interface descriptor. This means that:
          * (i) parameter types must be identical to those of the target descriptor; (ii) return
          * types must be compatible with the return type of the expected descriptor.
          */
          void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext) {
              Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
  
              //return values have already been checked - but if lambda has no return
              //values, we must ensure that void/value compatibility is correct;
              //this amounts at checking that, if a lambda body can complete normally,
              //the descriptor's return type must be void
              if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
                      !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
                  Fragment msg =
                          Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
                  checkContext.report(tree,
                                      diags.fragment(msg));
              }
  
              List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
              if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
                  checkContext.report(tree, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
              }
          }
  
          /* Map to hold 'fake' clinit methods. If a lambda is used to initialize a
           * static field and that lambda has type annotations, these annotations will
           * also be stored at these fake clinit methods.
           *
           * LambdaToMethod also use fake clinit methods so they can be reused.
           * Also as LTM is a phase subsequent to attribution, the methods from
           * clinits can be safely removed by LTM to save memory.
           */
          private Map<ClassSymbol, MethodSymbol> clinits = new HashMap<>();
  
          public MethodSymbol removeClinit(ClassSymbol sym) {
              return clinits.remove(sym);
          }
  
          /* This method returns an environment to be used to attribute a lambda
           * expression.
           *
           * The owner of this environment is a method symbol. If the current owner
           * is not a method, for example if the lambda is used to initialize
           * a field, then if the field is:
           *
           * - an instance field, we use the first constructor.
           * - a static field, we create a fake clinit method.
           */
          public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
              Env<AttrContext> lambdaEnv;
              Symbol owner = env.info.scope.owner;
              if (owner.kind == VAR && owner.owner.kind == TYP) {
                  //field initializer
                  ClassSymbol enclClass = owner.enclClass();
                  Symbol newScopeOwner = env.info.scope.owner;
                  /* if the field isn't static, then we can get the first constructor
                   * and use it as the owner of the environment. This is what
                   * LTM code is doing to look for type annotations so we are fine.
                   */
                  if ((owner.flags() & STATIC) == 0) {
                      for (Symbol s : enclClass.members_field.getSymbolsByName(names.init)) {
                          newScopeOwner = s;
                          break;
                      }
                  } else {
                      /* if the field is static then we need to create a fake clinit
                       * method, this method can later be reused by LTM.
                       */
                      MethodSymbol clinit = clinits.get(enclClass);
                      if (clinit == null) {
                          Type clinitType = new MethodType(List.nil(),
                                  syms.voidType, List.nil(), syms.methodClass);
                          clinit = new MethodSymbol(STATIC | SYNTHETIC | PRIVATE,
                                  names.clinit, clinitType, enclClass);
                          clinit.params = List.nil();
                          clinits.put(enclClass, clinit);
                      }
                      newScopeOwner = clinit;
                  }
                  lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(newScopeOwner)));
              } else {
                  lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
              }
              lambdaEnv.info.yieldResult = null;
              lambdaEnv.info.isLambda = true;
              return lambdaEnv;
          }
  
      @Override
      public void visitReference(final JCMemberReference that) {
          if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
              if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
                  //method reference only allowed in assignment or method invocation/cast context
                  log.error(that.pos(), Errors.UnexpectedMref);
              }
              result = that.type = types.createErrorType(pt());
              return;
          }
          final Env<AttrContext> localEnv = env.dup(that);
          try {
              //attribute member reference qualifier - if this is a constructor
              //reference, the expected kind must be a type
              Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
  
              if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
                  exprType = chk.checkConstructorRefType(that.expr, exprType);
                  if (!exprType.isErroneous() &&
                      exprType.isRaw() &&
                      that.typeargs != null) {
                      log.error(that.expr.pos(),
                                Errors.InvalidMref(Kinds.kindName(that.getMode()),
                                                   Fragments.MrefInferAndExplicitParams));
                      exprType = types.createErrorType(exprType);
                  }
              }
  
              if (exprType.isErroneous()) {
                  //if the qualifier expression contains problems,
                  //give up attribution of method reference
                  result = that.type = exprType;
                  return;
              }
  
              if (TreeInfo.isStaticSelector(that.expr, names)) {
                  //if the qualifier is a type, validate it; raw warning check is
                  //omitted as we don't know at this stage as to whether this is a
                  //raw selector (because of inference)
                  chk.validate(that.expr, env, false);
              } else {
                  Symbol lhsSym = TreeInfo.symbol(that.expr);
                  localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
              }
              //attrib type-arguments
              List<Type> typeargtypes = List.nil();
              if (that.typeargs != null) {
                  typeargtypes = attribTypes(that.typeargs, localEnv);
              }
  
              boolean isTargetSerializable =
                      resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
                      isSerializable(pt());
              TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
              Type currentTarget = targetInfo.target;
              Type desc = targetInfo.descriptor;
  
              setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
              List<Type> argtypes = desc.getParameterTypes();
              Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
  
              if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
                  referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
              }
  
              Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
              List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
              try {
                  refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
                          that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
                          resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
              } finally {
                  resultInfo.checkContext.inferenceContext().rollback(saved_undet);
              }
  
              Symbol refSym = refResult.fst;
              Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
  
              /** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
               *  JDK-8075541
               */
              if (refSym.kind != MTH) {
                  boolean targetError;
                  switch (refSym.kind) {
                      case ABSENT_MTH:
                      case MISSING_ENCL:
                          targetError = false;
                          break;
                      case WRONG_MTH:
                      case WRONG_MTHS:
                      case AMBIGUOUS:
                      case HIDDEN:
                      case STATICERR:
                          targetError = true;
                          break;
                      default:
                          Assert.error("unexpected result kind " + refSym.kind);
                          targetError = false;
                  }
  
                  JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
                          .getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
                                  that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
  
                  JCDiagnostic diag = diags.create(log.currentSource(), that,
                          targetError ?
                              Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
                              Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
  
                  if (targetError && currentTarget == Type.recoveryType) {
                      //a target error doesn't make sense during recovery stage
                      //as we don't know what actual parameter types are
                      result = that.type = currentTarget;
                      return;
                  } else {
                      if (targetError) {
                          resultInfo.checkContext.report(that, diag);
                      } else {
                          log.report(diag);
                      }
                      result = that.type = types.createErrorType(currentTarget);
                      return;
                  }
              }
  
              that.sym = refSym.isConstructor() ? refSym.baseSymbol() : refSym;
              that.kind = lookupHelper.referenceKind(that.sym);
              that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
  
              if (desc.getReturnType() == Type.recoveryType) {
                  // stop here
                  result = that.type = currentTarget;
                  return;
              }
  
              if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
                  Type enclosingType = exprType.getEnclosingType();
                  if (enclosingType != null && enclosingType.hasTag(CLASS)) {
                      // Check for the existence of an appropriate outer instance
                      rs.resolveImplicitThis(that.pos(), env, exprType);
                  }
              }
  
              if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
  
                  if (that.getMode() == ReferenceMode.INVOKE &&
                          TreeInfo.isStaticSelector(that.expr, names) &&
                          that.kind.isUnbound() &&
                          lookupHelper.site.isRaw()) {
                      chk.checkRaw(that.expr, localEnv);
                  }
  
                  if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
                          exprType.getTypeArguments().nonEmpty()) {
                      //static ref with class type-args
                      log.error(that.expr.pos(),
                                Errors.InvalidMref(Kinds.kindName(that.getMode()),
                                                   Fragments.StaticMrefWithTargs));
                      result = that.type = types.createErrorType(currentTarget);
                      return;
                  }
  
                  if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
                      // Check that super-qualified symbols are not abstract (JLS)
                      rs.checkNonAbstract(that.pos(), that.sym);
                  }
  
                  if (isTargetSerializable) {
                      chk.checkAccessFromSerializableElement(that, true);
                  }
              }
  
              ResultInfo checkInfo =
                      resultInfo.dup(newMethodTemplate(
                          desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
                          that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
                          new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
  
              Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
  
              if (that.kind.isUnbound() &&
                      resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
                  //re-generate inference constraints for unbound receiver
                  if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
                      //cannot happen as this has already been checked - we just need
                      //to regenerate the inference constraints, as that has been lost
                      //as a result of the call to inferenceContext.save()
                      Assert.error("Can't get here");
                  }
              }
  
              if (!refType.isErroneous()) {
                  refType = types.createMethodTypeWithReturn(refType,
                          adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
              }
  
              //go ahead with standard method reference compatibility check - note that param check
              //is a no-op (as this has been taken care during method applicability)
              boolean isSpeculativeRound =
                      resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
  
              that.type = currentTarget; //avoids recovery at this stage
              checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
              if (!isSpeculativeRound) {
                  checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
              }
              result = check(that, currentTarget, KindSelector.VAL, resultInfo);
          } catch (Types.FunctionDescriptorLookupError ex) {
              JCDiagnostic cause = ex.getDiagnostic();
              resultInfo.checkContext.report(that, cause);
              result = that.type = types.createErrorType(pt());
              return;
          }
      }
      //where
          ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
              //if this is a constructor reference, the expected kind must be a type
              return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
                                    KindSelector.VAL_TYP : KindSelector.TYP,
                                    Type.noType);
          }
  
  
      @SuppressWarnings("fallthrough")
      void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
          InferenceContext inferenceContext = checkContext.inferenceContext();
          Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
  
          Type resType;
          switch (tree.getMode()) {
              case NEW:
                  if (!tree.expr.type.isRaw()) {
                      resType = tree.expr.type;
                      break;
                  }
              default:
                  resType = refType.getReturnType();
          }
  
          Type incompatibleReturnType = resType;
  
          if (returnType.hasTag(VOID)) {
              incompatibleReturnType = null;
          }
  
          if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
              if (resType.isErroneous() ||
                      new FunctionalReturnContext(checkContext).compatible(resType, returnType,
                              checkContext.checkWarner(tree, resType, returnType))) {
                  incompatibleReturnType = null;
              }
          }
  
          if (incompatibleReturnType != null) {
              Fragment msg =
                      Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
              checkContext.report(tree, diags.fragment(msg));
          } else {
              if (inferenceContext.free(refType)) {
                  // we need to wait for inference to finish and then replace inference vars in the referent type
                  inferenceContext.addFreeTypeListener(List.of(refType),
                          instantiatedContext -> {
                              tree.referentType = instantiatedContext.asInstType(refType);
                          });
              } else {
                  tree.referentType = refType;
              }
          }
  
          if (!speculativeAttr) {
              if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
                  log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
              }
          }
      }
  
      boolean checkExConstraints(
              List<Type> thrownByFuncExpr,
              List<Type> thrownAtFuncType,
              InferenceContext inferenceContext) {
          /** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
           *  are not proper types
           */
          List<Type> nonProperList = thrownAtFuncType.stream()
                  .filter(e -> inferenceContext.free(e)).collect(List.collector());
          List<Type> properList = thrownAtFuncType.diff(nonProperList);
  
          /** Let X1,...,Xm be the checked exception types that the lambda body can throw or
           *  in the throws clause of the invocation type of the method reference's compile-time
           *  declaration
           */
          List<Type> checkedList = thrownByFuncExpr.stream()
                  .filter(e -> chk.isChecked(e)).collect(List.collector());
  
          /** If n = 0 (the function type's throws clause consists only of proper types), then
           *  if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
           *  in the throws clause, the constraint reduces to false; otherwise, the constraint
           *  reduces to true
           */
          ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
          for (Type checked : checkedList) {
              boolean isSubtype = false;
              for (Type proper : properList) {
                  if (types.isSubtype(checked, proper)) {
                      isSubtype = true;
                      break;
                  }
              }
              if (!isSubtype) {
                  uncaughtByProperTypes.add(checked);
              }
          }
  
          if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
              return false;
          }
  
          /** If n > 0, the constraint reduces to a set of subtyping constraints:
           *  for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
           *  throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
           */
          List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
          uncaughtByProperTypes.forEach(checkedEx -> {
              nonProperAsUndet.forEach(nonProper -> {
                  types.isSubtype(checkedEx, nonProper);
              });
          });
  
          /** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
           */
          nonProperAsUndet.stream()
                  .filter(t -> t.hasTag(UNDETVAR))
                  .forEach(t -> ((UndetVar)t).setThrow());
          return true;
      }
  
      /**
       * Set functional type info on the underlying AST. Note: as the target descriptor
       * might contain inference variables, we might need to register an hook in the
       * current inference context.
       */
      private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
              final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
          if (checkContext.inferenceContext().free(descriptorType)) {
              checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
                      inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
                      inferenceContext.asInstType(primaryTarget), checkContext));
          } else {
              if (pt.hasTag(CLASS)) {
                  fExpr.target = primaryTarget;
              }
              if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
                      pt != Type.recoveryType) {
                  //check that functional interface class is well-formed
                  try {
                      /* Types.makeFunctionalInterfaceClass() may throw an exception
                       * when it's executed post-inference. See the listener code
                       * above.
                       */
                      ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
                              names.empty, fExpr.target, ABSTRACT);
                      if (csym != null) {
                          chk.checkImplementations(env.tree, csym, csym);
                          try {
                              //perform an additional functional interface check on the synthetic class,
                              //as there may be spurious errors for raw targets - because of existing issues
                              //with membership and inheritance (see JDK-8074570).
                              csym.flags_field |= INTERFACE;
                              types.findDescriptorType(csym.type);
                          } catch (FunctionDescriptorLookupError err) {
                              resultInfo.checkContext.report(fExpr,
                                      diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
                          }
                      }
                  } catch (Types.FunctionDescriptorLookupError ex) {
                      JCDiagnostic cause = ex.getDiagnostic();
                      resultInfo.checkContext.report(env.tree, cause);
                  }
              }
          }
      }
  
      public void visitParens(JCParens tree) {
          Type owntype = attribTree(tree.expr, env, resultInfo);
          result = check(tree, owntype, pkind(), resultInfo);
          Symbol sym = TreeInfo.symbol(tree);
          if (sym != null && sym.kind.matches(KindSelector.TYP_PCK) && sym.kind != Kind.ERR)
              log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
      }
  
      public void visitAssign(JCAssign tree) {
          Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
          Type capturedType = capture(owntype);
          attribExpr(tree.rhs, env, owntype);
          result = check(tree, capturedType, KindSelector.VAL, resultInfo);
      }
  
      public void visitAssignop(JCAssignOp tree) {
          // Attribute arguments.
          Type owntype = attribTree(tree.lhs, env, varAssignmentInfo);
          Type operand = attribExpr(tree.rhs, env);
          // Find operator.
          Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
          if (operator != operators.noOpSymbol &&
                  !owntype.isErroneous() &&
                  !operand.isErroneous()) {
              chk.checkDivZero(tree.rhs.pos(), operator, operand);
              chk.checkCastable(tree.rhs.pos(),
                                operator.type.getReturnType(),
                                owntype);
          }
          result = check(tree, owntype, KindSelector.VAL, resultInfo);
      }
  
      public void visitUnary(JCUnary tree) {
          // Attribute arguments.
          Type argtype = (tree.getTag().isIncOrDecUnaryOp())
              ? attribTree(tree.arg, env, varAssignmentInfo)
              : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
  
          // Find operator.
          Symbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
          Type owntype = types.createErrorType(tree.type);
          if (operator != operators.noOpSymbol &&
                  !argtype.isErroneous()) {
              owntype = (tree.getTag().isIncOrDecUnaryOp())
                  ? tree.arg.type
                  : operator.type.getReturnType();
              int opc = ((OperatorSymbol)operator).opcode;
  
              // If the argument is constant, fold it.
              if (argtype.constValue() != null) {
                  Type ctype = cfolder.fold1(opc, argtype);
                  if (ctype != null) {
                      owntype = cfolder.coerce(ctype, owntype);
                  }
              }
          }
          result = check(tree, owntype, KindSelector.VAL, resultInfo);
          matchBindings = matchBindingsComputer.unary(tree, matchBindings);
      }
  
      public void visitBinary(JCBinary tree) {
          boolean baCatched = false;
          try {
              // Attribute arguments.
              Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
          	// x && y
          	// include x's bindings when true in y
  
          	// x || y
         		// include x's bindings when false in y
  
          	MatchBindings lhsBindings = matchBindings;
          	List<BindingSymbol> propagatedBindings;
          	switch (tree.getTag()) {
              	case AND:
                		propagatedBindings = lhsBindings.bindingsWhenTrue;
                 		break;
              	case OR:
                  	propagatedBindings = lhsBindings.bindingsWhenFalse;
                  	break;
              	default:
                  	propagatedBindings = List.nil();
                  	break;
          	}
          	Env<AttrContext> rhsEnv = bindingEnv(env, propagatedBindings);
          	Type right;
          	try {
              	right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
          	} finally {
              	rhsEnv.info.scope.leave();
          	}
  
          	matchBindings = matchBindingsComputer.binary(tree, lhsBindings, matchBindings);
              // Find operator.
              Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
              Type owntype = types.createErrorType(tree.type);
              if (operator != operators.noOpSymbol &&
                      !left.isErroneous() &&
                      !right.isErroneous()) {
                  owntype = operator.type.getReturnType();
                  int opc = ((OperatorSymbol)operator).opcode;
                  // If both arguments are constants, fold them.
                  if (left.constValue() != null && right.constValue() != null) {
                      Type ctype = cfolder.fold2(opc, left, right);
                      if (ctype != null) {
                          owntype = cfolder.coerce(ctype, owntype);
                      }
                  }
  
                  // Check that argument types of a reference ==, != are
                  // castable to each other, (JLS 15.21).  Note: unboxing
                  // comparisons will not have an acmp* opc at this point.
                  if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
                      if (!types.isCastable(left, right, new Warner(tree.pos()))) {
                          log.error(tree.pos(), Errors.IncomparableTypes(left, right));
                      }
                  }
  
                  chk.checkDivZero(tree.rhs.pos(), operator, right);
              }
              result = check(tree, owntype, KindSelector.VAL, resultInfo);
          } catch (BreakAttr ba) {
              baCatched = true;
              throw ba;
          } finally {
              if ((baCatched || result.isErroneous()) && tree.hasTag(BITAND)) {
                  //error recovery
                  TreeScanner treeCleaner = new TreeScanner() {
                      public void scan(JCTree node) {
                          super.scan(node);
                          if (node != null)
                              node.type = null;
                      }
                      public void visitClassDef(JCClassDecl node) {
                          node.sym = null;
                          super.visitClassDef(node);
                      }
                      public void visitMethodDef(JCMethodDecl node) {
                          node.sym = null;
                          super.visitMethodDef(node);
                      }
                      public void visitVarDef(JCVariableDecl node) {
                          node.sym = null;
                          super.visitVarDef(node);
                      }
                      public void visitNewClass(JCNewClass node) {
                          node.constructor = null;
                          super.visitNewClass(node);
                      }
                      public void visitAssignop(JCAssignOp node) {
                          node.operator = null;
                          super.visitAssignop(node);
                      }
                      public void visitUnary(JCUnary node) {
                          node.operator = null;
                          super.visitUnary(node);
                      }
                      public void visitBinary(JCBinary node) {
                          node.operator = null;
                          super.visitBinary(node);
                      }
                      public void visitSelect(JCFieldAccess node) {
                          node.sym = null;
                          super.visitSelect(node);
                      }
                      public void visitIdent(JCIdent node) {
                          node.sym = null;
                          super.visitIdent(node);
                      }
                      public void visitAnnotation(JCAnnotation node) {
                          node.attribute = null;
                          super.visitAnnotation(node);
                      }
                  };
                  // attribTree will change the 'result', save it:
                  Type saveResult = this.result;
                  treeCleaner.scan(tree.lhs);
                  attribTree(tree.lhs, env, new ResultInfo(KindSelector.VAL_TYP , Type.noType));
                  treeCleaner.scan(tree.rhs);
                  attribTree(tree.rhs, env, new ResultInfo(KindSelector.VAL_TYP , Type.noType));
                  this.result = saveResult;
                  List<JCExpression> bounds = collectIntersectionBounds(tree);
                  if (bounds != null) {
                      Log.DiagnosticHandler discardHandler = new Log.DiscardDiagnosticHandler(log);
                      try {
                          Type owntype = checkIntersection(tree, bounds);
                          if (!owntype.isErroneous()) {
                              tree.type = result = owntype;
                          }
                      } finally {
                          log.popDiagnosticHandler(discardHandler);
                      }
                  }
              }
          }
      }
  
      private List<JCExpression> collectIntersectionBounds(JCTree tree) {
          if (tree.hasTag(BITAND)) {
              List<JCExpression> left = collectIntersectionBounds(((JCBinary)tree).lhs);
              if (left != null) {
                  List<JCExpression> right = collectIntersectionBounds(((JCBinary)tree).rhs);
                  if (right != null) {
                      return left.appendList(right);
                  }
              }
          } else if (tree instanceof JCExpression && tree.type != null) {
              return List.of((JCExpression)tree);
          }
          return null;
      }
  
      public void visitTypeCast(final JCTypeCast tree) {
          Type clazztype = attribType(tree.clazz, env);
          chk.validate(tree.clazz, env, false);
          //a fresh environment is required for 292 inference to work properly ---
          //see Infer.instantiatePolymorphicSignatureInstance()
          Env<AttrContext> localEnv = env.dup(tree);
          //should we propagate the target type?
          final ResultInfo castInfo;
          JCExpression expr = TreeInfo.skipParens(tree.expr);
          boolean isPoly = expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE);
          if (isPoly) {
              //expression is a poly - we need to propagate target type info
              castInfo = new ResultInfo(KindSelector.VAL, clazztype,
                                        new Check.NestedCheckContext(resultInfo.checkContext) {
                  @Override
                  public boolean compatible(Type found, Type req, Warner warn) {
                      return types.isCastable(found, req, warn);
                  }
              });
          } else {
              //standalone cast - target-type info is not propagated
              castInfo = unknownExprInfo;
          }
          Type exprtype = attribTree(tree.expr, localEnv, castInfo);
          Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
          if (exprtype.constValue() != null)
              owntype = cfolder.coerce(exprtype, owntype);
          result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
          if (!isPoly)
              chk.checkRedundantCast(localEnv, tree);
      }
  
      public void visitTypeTest(JCInstanceOf tree) {
          Type exprtype = chk.checkNullOrRefType(
                  tree.expr.pos(), attribExpr(tree.expr, env));
          Type clazztype;
          JCTree typeTree;
          if (tree.pattern.getTag() == BINDINGPATTERN ||
             tree.pattern.getTag() == PARENTHESIZEDPATTERN) {
              attribTree(tree.pattern, env, unknownExprInfo);
              clazztype = tree.pattern.type;
              if (types.isSubtype(exprtype, clazztype) &&
                  !exprtype.isErroneous() && !clazztype.isErroneous()) {
                  log.error(tree.pos(), Errors.InstanceofPatternNoSubtype(exprtype, clazztype));
              }
              typeTree = TreeInfo.primaryPatternTree((JCPattern) tree.pattern).var.vartype;
          } else {
              clazztype = attribType(tree.pattern, env);
              typeTree = tree.pattern;
              chk.validate(typeTree, env, false);
          }
          if (!clazztype.hasTag(TYPEVAR)) {
              clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
          }
          if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
              boolean valid = false;
              if (allowReifiableTypesInInstanceof) {
                  valid = checkCastablePattern(tree.expr.pos(), exprtype, clazztype);
              } else {
                  log.error(DiagnosticFlag.SOURCE_LEVEL, tree.pos(),
                            Feature.REIFIABLE_TYPES_INSTANCEOF.error(this.sourceName));
                  allowReifiableTypesInInstanceof = true;
              }
              if (!valid) {
                  clazztype = types.createErrorType(clazztype);
              }
          }
          chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
          result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
      }
  
      private boolean checkCastablePattern(DiagnosticPosition pos,
                                           Type exprType,
                                           Type pattType) {
          Warner warner = new Warner();
          if (!types.isCastable(exprType, pattType, warner)) {
              chk.basicHandler.report(pos,
                      diags.fragment(Fragments.InconvertibleTypes(exprType, pattType)));
              return false;
          } else if (warner.hasLint(LintCategory.UNCHECKED)) {
              log.error(pos,
                      Errors.InstanceofReifiableNotSafe(exprType, pattType));
              return false;
          } else {
              return true;
          }
      }
  
      public void visitBindingPattern(JCBindingPattern tree) {
          ResultInfo varInfo = new ResultInfo(KindSelector.TYP, resultInfo.pt, resultInfo.checkContext);
          tree.type = tree.var.type = attribTree(tree.var.vartype, env, varInfo);
          BindingSymbol v = new BindingSymbol(tree.var.mods.flags, tree.var.name, tree.var.vartype.type, env.info.scope.owner);
          v.pos = tree.pos;
          tree.var.sym = v;
          if (chk.checkUnique(tree.var.pos(), v, env.info.scope)) {
              chk.checkTransparentVar(tree.var.pos(), v, env.info.scope);
          }
          annotate.annotateLater(tree.var.mods.annotations, env, v, tree.pos());
          annotate.queueScanTreeAndTypeAnnotate(tree.var.vartype, env, v, tree.var.pos());
          annotate.flush();
          chk.validate(tree.var.vartype, env, true);
          result = tree.type;
          matchBindings = new MatchBindings(List.of(v), List.nil());
      }
  
      @Override
      public void visitParenthesizedPattern(JCParenthesizedPattern tree) {
          attribExpr(tree.pattern, env);
          result = tree.type = tree.pattern.type;
      }
  
      @Override
      public void visitGuardPattern(JCGuardPattern tree) {
          attribExpr(tree.patt, env);
          MatchBindings afterPattern = matchBindings;
          Env<AttrContext> bodyEnv = bindingEnv(env, matchBindings.bindingsWhenTrue);
          try {
              attribExpr(tree.expr, bodyEnv, syms.booleanType);
          } finally {
              bodyEnv.info.scope.leave();
          }
          result = tree.type = tree.patt.type;
          matchBindings = matchBindingsComputer.guardedPattern(tree, afterPattern, matchBindings);
      }
  
      public void visitIndexed(JCArrayAccess tree) {
          Type owntype = types.createErrorType(tree.type);
          Type atype = attribExpr(tree.indexed, env);
          attribExpr(tree.index, env, syms.intType);
          if (types.isArray(atype))
              owntype = types.elemtype(atype);
          else if (!atype.hasTag(ERROR))
              log.error(tree.pos(), Errors.ArrayReqButFound(atype));
          if (!pkind().contains(KindSelector.VAL))
              owntype = capture(owntype);
          result = check(tree, owntype, KindSelector.VAR, resultInfo);
      }
  
      public void visitIdent(JCIdent tree) {
          Symbol sym;
  
          // Find symbol
          if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
              // If we are looking for a method, the prototype `pt' will be a
              // method type with the type of the call's arguments as parameters.
              env.info.pendingResolutionPhase = null;
              sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
          } else if (tree.sym != null && tree.sym.kind != VAR) {
              sym = tree.sym;
          } else {
              sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
          }
          tree.sym = sym;
  
          // (1) Also find the environment current for the class where
          //     sym is defined (`symEnv').
          // Only for pre-tiger versions (1.4 and earlier):
          // (2) Also determine whether we access symbol out of an anonymous
          //     class in a this or super call.  This is illegal for instance
          //     members since such classes don't carry a this$n link.
          //     (`noOuterThisPath').
          Env<AttrContext> symEnv = env;
          boolean noOuterThisPath = false;
          if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
              sym.kind.matches(KindSelector.VAL_MTH) &&
              sym.owner.kind == TYP &&
              tree.name != names._this && tree.name != names._super) {
  
              // Find environment in which identifier is defined.
              while (symEnv.outer != null &&
                     !sym.isMemberOf(symEnv.enclClass.sym, types)) {
                  if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
                      noOuterThisPath = false;
                  symEnv = symEnv.outer;
              }
          }
  
          // If symbol is a variable, ...
          if (sym.kind == VAR) {
              VarSymbol v = (VarSymbol)sym;
  
              // ..., evaluate its initializer, if it has one, and check for
              // illegal forward reference.
              checkInit(tree, env, v, false);
  
              // If we are expecting a variable (as opposed to a value), check
              // that the variable is assignable in the current environment.
              if (KindSelector.ASG.subset(pkind()))
                  checkAssignable(tree.pos(), v, null, env);
          }
  
          // In a constructor body,
          // if symbol is a field or instance method, check that it is
          // not accessed before the supertype constructor is called.
          if ((symEnv.info.isSelfCall || noOuterThisPath) &&
              sym.kind.matches(KindSelector.VAL_MTH) &&
              sym.owner.kind == TYP &&
              (sym.flags() & STATIC) == 0) {
              chk.earlyRefError(tree.pos(), sym.kind == VAR ?
                                            sym : thisSym(tree.pos(), env));
          }
          Env<AttrContext> env1 = env;
          if (sym.kind != ERR && sym.kind != TYP &&
              sym.owner != null && sym.owner != env1.enclClass.sym) {
              // If the found symbol is inaccessible, then it is
              // accessed through an enclosing instance.  Locate this
              // enclosing instance:
              while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
                  env1 = env1.outer;
          }
  
          if (env.info.isSerializable) {
              chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
          }
  
          result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
      }
  
      public void visitSelect(JCFieldAccess tree) {
          // Determine the expected kind of the qualifier expression.
          KindSelector skind = KindSelector.NIL;
          if (tree.name == names._this || tree.name == names._super ||
                  tree.name == names._class)
          {
              skind = KindSelector.TYP;
          } else if (tree.name == names.error) {
              skind = KindSelector.ERR;
          } else {
              if (pkind().contains(KindSelector.PCK))
                  skind = KindSelector.of(skind, KindSelector.PCK);
              if (pkind().contains(KindSelector.TYP))
                  skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
              if (pkind().contains(KindSelector.VAL_MTH))
                  skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
          }
  
          // Attribute the qualifier expression, and determine its symbol (if any).
          Type site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));
          if (!pkind().contains(KindSelector.TYP_PCK))
              site = capture(site); // Capture field access
  
          // don't allow T.class T[].class, etc
          if (skind == KindSelector.TYP) {
              Type elt = site;
              while (elt.hasTag(ARRAY))
                  elt = ((ArrayType)elt).elemtype;
              if (elt.hasTag(TYPEVAR)) {
                  log.error(tree.pos(), Errors.TypeVarCantBeDeref);
                  result = tree.type = types.createErrorType(tree.name, site.tsym, site);
                  tree.sym = tree.type.tsym;
                  return ;
              }
          }
  
          // If qualifier symbol is a type or `super', assert `selectSuper'
          // for the selection. This is relevant for determining whether
          // protected symbols are accessible.
          Symbol sitesym = TreeInfo.symbol(tree.selected);
          boolean selectSuperPrev = env.info.selectSuper;
          env.info.selectSuper =
              sitesym != null &&
              sitesym.name == names._super;
  
          // Determine the symbol represented by the selection.
          env.info.pendingResolutionPhase = null;
          Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
          if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
              log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
              sym = syms.errSymbol;
          }
          if (sym.exists() && !isType(sym) && pkind().contains(KindSelector.TYP_PCK)) {
              site = capture(site);
              sym = selectSym(tree, sitesym, site, env, resultInfo);
          }
          boolean varArgs = env.info.lastResolveVarargs();
          tree.sym = sym;
  
          if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
              site = types.skipTypeVars(site, true);
          }
  
          // If that symbol is a variable, ...
          if (sym.kind == VAR) {
              VarSymbol v = (VarSymbol)sym;
  
              // ..., evaluate its initializer, if it has one, and check for
              // illegal forward reference.
              checkInit(tree, env, v, true);
  
              // If we are expecting a variable (as opposed to a value), check
              // that the variable is assignable in the current environment.
              if (KindSelector.ASG.subset(pkind()))
                  checkAssignable(tree.pos(), v, tree.selected, env);
          }
  
          if (sitesym != null &&
                  sitesym.kind == VAR &&
                  ((VarSymbol)sitesym).isResourceVariable() &&
                  sym.kind == MTH &&
                  sym.name.equals(names.close) &&
                  sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
                  env.info.lint.isEnabled(LintCategory.TRY)) {
              log.warning(LintCategory.TRY, tree, Warnings.TryExplicitCloseCall);
          }
  
          // Disallow selecting a type from an expression
          if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
              tree.type = check(tree.selected, pt(),
                                sitesym == null ?
                                        KindSelector.VAL : sitesym.kind.toSelector(),
                                new ResultInfo(KindSelector.TYP_PCK, pt()));
          }
  
          if (isType(sitesym)) {
              if (sym.name == names._this) {
                  // If `C' is the currently compiled class, check that
                  // C.this' does not appear in a call to a super(...)
                  if (env.info.isSelfCall &&
                      site.tsym == env.enclClass.sym) {
                      chk.earlyRefError(tree.pos(), sym);
                  }
              } else {
                  // Check if type-qualified fields or methods are static (JLS)
                  if ((sym.flags() & STATIC) == 0 &&
                      sym.name != names._super &&
                      (sym.kind == VAR || sym.kind == MTH)) {
                      rs.accessBase(rs.new StaticError(sym),
                                tree.pos(), site, sym.name, true);
                  }
              }
              if (!allowStaticInterfaceMethods && sitesym.isInterface() &&
                      sym.isStatic() && sym.kind == MTH) {
                  log.error(DiagnosticFlag.SOURCE_LEVEL, tree.pos(), Feature.STATIC_INTERFACE_METHODS_INVOKE.error(sourceName));
              }
          } else if (sym.kind != ERR &&
                     (sym.flags() & STATIC) != 0 &&
                     sym.name != names._class) {
              // If the qualified item is not a type and the selected item is static, report
              // a warning. Make allowance for the class of an array type e.g. Object[].class)
              chk.warnStatic(tree, Warnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
          }
  
          // If we are selecting an instance member via a `super', ...
          if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
  
              // Check that super-qualified symbols are not abstract (JLS)
              rs.checkNonAbstract(tree.pos(), sym);
  
              if (site.isRaw()) {
                  // Determine argument types for site.
                  Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
                  if (site1 != null) site = site1;
              }
          }
  
          if (env.info.isSerializable) {
              chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
          }
  
          env.info.selectSuper = selectSuperPrev;
          result = checkId(tree, site, sym, env, resultInfo);
      }
      //where
          /** Determine symbol referenced by a Select expression,
           *
           *  @param tree   The select tree.
           *  @param site   The type of the selected expression,
           *  @param env    The current environment.
           *  @param resultInfo The current result.
           */
          private Symbol selectSym(JCFieldAccess tree,
                                   Symbol location,
                                   Type site,
                                   Env<AttrContext> env,
                                   ResultInfo resultInfo) {
              DiagnosticPosition pos = tree.pos();
              Name name = tree.name;
              switch (site.getTag()) {
              case PACKAGE:
                  return rs.accessBase(
                      rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
                      pos, location, site, name, true);
              case ARRAY:
              case CLASS:
                  if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
                      return rs.resolveQualifiedMethod(
                          pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
                  } else if (name == names._this || name == names._super) {
                      return rs.resolveSelf(pos, env, site.tsym, name);
                  } else if (name == names._class) {
                      // In this case, we have already made sure in
                      // visitSelect that qualifier expression is a type.
                      return syms.getClassField(site, types);
                  } else {
                      // We are seeing a plain identifier as selector.
                      Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind);
                          sym = rs.accessBase(sym, pos, location, site, name, true);
                      return sym;
                  }
              case WILDCARD:
                  throw new AssertionError(tree);
              case TYPEVAR:
                  // Normally, site.getUpperBound() shouldn't be null.
                  // It should only happen during memberEnter/attribBase
                  // when determining the super type which *must* be
                  // done before attributing the type variables.  In
                  // other words, we are seeing this illegal program:
                  // class B<T> extends A<T.foo> {}
                  Symbol sym = (site.getUpperBound() != null)
                      ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
                      : null;
                  if (sym == null) {
                      log.error(pos, Errors.TypeVarCantBeDeref);
                      return syms.errSymbol;
                  } else {
                      Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
                          rs.new AccessError(env, site, sym) :
                                  sym;
                      rs.accessBase(sym2, pos, location, site, name, true);
                      return sym;
                  }
              case ERROR:
                  // preserve identifier names through errors
                  return types.createErrorType(name, site.tsym, site).tsym;
              default:
                  // The qualifier expression is of a primitive type -- only
                  // .class is allowed for these.
                  if (name == names._class) {
                      // In this case, we have already made sure in Select that
                      // qualifier expression is a type.
                      return syms.getClassField(site, types);
                  } else {
                      log.error(pos, Errors.CantDeref(site));
                      return syms.errSymbol;
                  }
              }
          }
  
          /** Determine type of identifier or select expression and check that
           *  (1) the referenced symbol is not deprecated
           *  (2) the symbol's type is safe (@see checkSafe)
           *  (3) if symbol is a variable, check that its type and kind are
           *      compatible with the prototype and protokind.
           *  (4) if symbol is an instance field of a raw type,
           *      which is being assigned to, issue an unchecked warning if its
           *      type changes under erasure.
           *  (5) if symbol is an instance method of a raw type, issue an
           *      unchecked warning if its argument types change under erasure.
           *  If checks succeed:
           *    If symbol is a constant, return its constant type
           *    else if symbol is a method, return its result type
           *    otherwise return its type.
           *  Otherwise return errType.
           *
           *  @param tree       The syntax tree representing the identifier
           *  @param site       If this is a select, the type of the selected
           *                    expression, otherwise the type of the current class.
           *  @param sym        The symbol representing the identifier.
           *  @param env        The current environment.
           *  @param resultInfo    The expected result
           */
          Type checkId(JCTree tree,
                       Type site,
                       Symbol sym,
                       Env<AttrContext> env,
                       ResultInfo resultInfo) {
              return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
                      checkMethodIdInternal(tree, site, sym, env, resultInfo) :
                      checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
          }
  
          Type checkMethodIdInternal(JCTree tree,
                       Type site,
                       Symbol sym,
                       Env<AttrContext> env,
                       ResultInfo resultInfo) {
              if (resultInfo.pkind.contains(KindSelector.POLY)) {
                  return attrRecover.recoverMethodInvocation(tree, site, sym, env, resultInfo);
              } else {
                  return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
              }
          }
  
          Type checkIdInternal(JCTree tree,
                       Type site,
                       Symbol sym,
                       Type pt,
                       Env<AttrContext> env,
                       ResultInfo resultInfo) {
              if (pt.isErroneous()) {
                  return tree.type = types.createErrorType(site);
              }
              Type owntype; // The computed type of this identifier occurrence.
              switch (sym.kind) {
              case TYP:
                  // For types, the computed type equals the symbol's type,
                  // except for two situations:
                  owntype = sym.type;
                  if (owntype.hasTag(CLASS)) {
                      chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
                      Type ownOuter = owntype.getEnclosingType();
  
                      // (a) If the symbol's type is parameterized, erase it
                      // because no type parameters were given.
                      // We recover generic outer type later in visitTypeApply.
                      if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
                          owntype = types.erasure(owntype);
                      }
  
                      // (b) If the symbol's type is an inner class, then
                      // we have to interpret its outer type as a superclass
                      // of the site type. Example:
                      //
                      // class Tree<A> { class Visitor { ... } }
                      // class PointTree extends Tree<Point> { ... }
                      // ...PointTree.Visitor...
                      //
                      // Then the type of the last expression above is
                      // Tree<Point>.Visitor.
                      else if (ownOuter != null && ownOuter.hasTag(CLASS) && site != ownOuter) {
                          Type normOuter = site;
                          if (normOuter.hasTag(CLASS)) {
                              normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
                          }
                          if (normOuter == null) // perhaps from an import
                              normOuter = types.erasure(ownOuter);
                          if (normOuter != ownOuter)
                              owntype = new ClassType(
                                  normOuter, List.nil(), owntype.tsym,
                                  owntype.getMetadata());
                      }
                  }
                  break;
              case VAR:
                  VarSymbol v = (VarSymbol)sym;
  
                  if (env.info.enclVar != null
                          && v.type.hasTag(NONE)) {
                      //self reference to implicitly typed variable declaration
                      log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
                      return v.type = types.createErrorType(v.type);
                  }
  
                  // Test (4): if symbol is an instance field of a raw type,
                  // which is being assigned to, issue an unchecked warning if
                  // its type changes under erasure.
                  if (KindSelector.ASG.subset(pkind()) &&
                      v.owner.kind == TYP &&
                      (v.flags() & STATIC) == 0 &&
                      (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
                      Type s = types.asOuterSuper(site, v.owner);
                      if (s != null &&
                          s.isRaw() &&
                          !types.isSameType(v.type, v.erasure(types))) {
                          chk.warnUnchecked(tree.pos(), Warnings.UncheckedAssignToVar(v, s));
                      }
                  }
                  // The computed type of a variable is the type of the
                  // variable symbol, taken as a member of the site type.
                  owntype = (sym.owner.kind == TYP &&
                             sym.name != names._this && sym.name != names._super)
                      ? types.memberType(site, sym)
                      : sym.type;
  
                  // If the variable is a constant, record constant value in
                  // computed type.
                  if (v.getConstValue() != null && isStaticReference(tree))
                      owntype = owntype.constType(v.getConstValue());
  
                  if (resultInfo.pkind == KindSelector.VAL) {
                      owntype = capture(owntype); // capture "names as expressions"
                  }
                  break;
              case MTH: {
                  owntype = checkMethod(site, sym,
                          new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
                          env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
                          resultInfo.pt.getTypeArguments());
                  break;
              }
              case PCK: case ERR:
                  owntype = sym.type;
                  break;
              default:
                  throw new AssertionError("unexpected kind: " + sym.kind +
                                           " in tree " + tree);
              }
  
              // Emit a `deprecation' warning if symbol is deprecated.
              // (for constructors (but not for constructor references), the error
              // was given when the constructor was resolved)
  
              if (sym.name != names.init || tree.hasTag(REFERENCE)) {
                  chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
                  chk.checkSunAPI(tree.pos(), sym);
                  chk.checkProfile(tree.pos(), sym);
  
                  chk.checkPreview(tree.pos() , env.info.scope.owner, sym);
  		}
              Env<AttrContext> enclosing;
              if (owntype.isErroneous() && (sym.kind == MTH || sym.kind == VAR) && ((enclosing = enter.getEnv(sym.enclClass())) == null || enclosing.toplevel != env.toplevel)) {
                  log.error(tree.pos(), Errors.TypeError(sym));
  
              }
  
              // If symbol is a variable, check that its type and
              // kind are compatible with the prototype and protokind.
              return check(tree, owntype, sym.kind.toSelector(), resultInfo);
          }
  
          /** Check that variable is initialized and evaluate the variable's
           *  initializer, if not yet done. Also check that variable is not
           *  referenced before it is defined.
           *  @param tree    The tree making up the variable reference.
           *  @param env     The current environment.
           *  @param v       The variable's symbol.
           */
          private void checkInit(JCTree tree,
                                 Env<AttrContext> env,
                                 VarSymbol v,
                                 boolean onlyWarning) {
              // A forward reference is diagnosed if the declaration position
              // of the variable is greater than the current tree position
              // and the tree and variable definition occur in the same class
              // definition.  Note that writes don't count as references.
              // This check applies only to class and instance
              // variables.  Local variables follow different scope rules,
              // and are subject to definite assignment checking.
              Env<AttrContext> initEnv = enclosingInitEnv(env);
              if (initEnv != null &&
                  (initEnv.info.enclVar == v || v.pos > tree.pos) &&
                  v.owner.kind == TYP &&
                  v.owner == env.info.scope.owner.enclClass() &&
                  ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
                  (!env.tree.hasTag(ASSIGN) ||
                   TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
                  if (!onlyWarning || isStaticEnumField(v)) {
                      Error errkey = (initEnv.info.enclVar == v) ?
                                  Errors.IllegalSelfRef : Errors.IllegalForwardRef;
                      log.error(tree.pos(), errkey);
                  } else if (useBeforeDeclarationWarning) {
                      Warning warnkey = (initEnv.info.enclVar == v) ?
                                  Warnings.SelfRef(v) : Warnings.ForwardRef(v);
                      log.warning(tree.pos(), warnkey);
                  }
              }
  
              v.getConstValue(); // ensure initializer is evaluated
  
              checkEnumInitializer(tree, env, v);
          }
  
          /**
           * Returns the enclosing init environment associated with this env (if any). An init env
           * can be either a field declaration env or a static/instance initializer env.
           */
          Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
              while (true) {
                  switch (env.tree.getTag()) {
                      case VARDEF:
                          JCVariableDecl vdecl = (JCVariableDecl)env.tree;
                          if (vdecl.sym != null && vdecl.sym.owner != null && vdecl.sym.owner.kind == TYP) {
                              //field
                              return env;
                          }
                          break;
                      case BLOCK:
                          if (env.next.tree.hasTag(CLASSDEF)) {
                              //instance/static initializer
                              return env;
                          }
                          break;
                      case METHODDEF:
                      case CLASSDEF:
                      case TOPLEVEL:
                          return null;
                  }
                  Assert.checkNonNull(env.next);
                  env = env.next;
              }
          }
  
          /**
           * Check for illegal references to static members of enum.  In
           * an enum type, constructors and initializers may not
           * reference its static members unless they are constant.
           *
           * @param tree    The tree making up the variable reference.
           * @param env     The current environment.
           * @param v       The variable's symbol.
           * @jls 8.9 Enum Types
           */
          private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
              // JLS:
              //
              // "It is a compile-time error to reference a static field
              // of an enum type that is not a compile-time constant
              // (15.28) from constructors, instance initializer blocks,
              // or instance variable initializer expressions of that
              // type. It is a compile-time error for the constructors,
              // instance initializer blocks, or instance variable
              // initializer expressions of an enum constant e to refer
              // to itself or to an enum constant of the same type that
              // is declared to the right of e."
              if (isStaticEnumField(v)) {
                  ClassSymbol enclClass = env.info.scope.owner.enclClass();
  
                  if (enclClass == null || enclClass.owner == null)
                      return;
  
                  // See if the enclosing class is the enum (or a
                  // subclass thereof) declaring v.  If not, this
                  // reference is OK.
                  if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
                      return;
  
                  // If the reference isn't from an initializer, then
                  // the reference is OK.
                  if (!Resolve.isInitializer(env))
                      return;
  
                  log.error(tree.pos(), Errors.IllegalEnumStaticRef);
              }
          }
  
          /** Is the given symbol a static, non-constant field of an Enum?
           *  Note: enum literals should not be regarded as such
           */
          private boolean isStaticEnumField(VarSymbol v) {
              return Flags.isEnum(v.owner) &&
                     Flags.isStatic(v) &&
                     !Flags.isConstant(v) &&
                     v.name != names._class;
          }
  
      /**
       * Check that method arguments conform to its instantiation.
       **/
      public Type checkMethod(Type site,
                              final Symbol sym,
                              ResultInfo resultInfo,
                              Env<AttrContext> env,
                              final List<JCExpression> argtrees,
                              List<Type> argtypes,
                              List<Type> typeargtypes) {
          // Test (5): if symbol is an instance method of a raw type, issue
          // an unchecked warning if its argument types change under erasure.
          if ((sym.flags() & STATIC) == 0 &&
              (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
              Type s = types.asOuterSuper(site, sym.owner);
              if (s != null && s.isRaw() &&
                  !types.isSameTypes(sym.type.getParameterTypes(),
                                     sym.erasure(types).getParameterTypes())) {
                  chk.warnUnchecked(env.tree.pos(), Warnings.UncheckedCallMbrOfRawType(sym, s));
              }
          }
  
          if (env.info.defaultSuperCallSite != null) {
              for (Type sup : types.interfaces(env.enclClass.sym.type).prepend(types.supertype((env.enclClass.sym.type)))) {
                  if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
                          types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
                  List<MethodSymbol> icand_sup =
                          types.interfaceCandidates(sup, (MethodSymbol)sym);
                  if (icand_sup.nonEmpty() &&
                          icand_sup.head != sym &&
                          icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
                      log.error(env.tree.pos(),
                                Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
                      break;
                  }
              }
              env.info.defaultSuperCallSite = null;
          }
  
          if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
              JCMethodInvocation app = (JCMethodInvocation)env.tree;
              if (app.meth.hasTag(SELECT) &&
                      !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
                  log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
              }
          }
  
          // Compute the identifier's instantiated type.
          // For methods, we need to compute the instance type by
          // Resolve.instantiate from the symbol's type as well as
          // any type arguments and value arguments.
          Warner noteWarner = new Warner();
          try {
              Type owntype = rs.checkMethod(
                      env,
                      site,
                      sym,
                      resultInfo,
                      argtypes,
                      typeargtypes,
                      noteWarner);
  
              DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
                  deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
  
              argtypes = argtypes.map(checkDeferredMap);
  
              if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
                  chk.warnUnchecked(env.tree.pos(), Warnings.UncheckedMethInvocationApplied(kindName(sym),
                          sym.name,
                          rs.methodArguments(sym.type.getParameterTypes()),
                          rs.methodArguments(argtypes.map(checkDeferredMap)),
                          kindName(sym.location()),
                          sym.location()));
                  if (resultInfo.pt != Infer.anyPoly ||
                          !owntype.hasTag(METHOD) ||
                          !owntype.isPartial()) {
                      //if this is not a partially inferred method type, erase return type. Otherwise,
                      //erasure is carried out in PartiallyInferredMethodType.check().
                      owntype = new MethodType(owntype.getParameterTypes(),
                              types.erasure(owntype.getReturnType()),
                              types.erasure(owntype.getThrownTypes()),
                              syms.methodClass);
                  }
              }
  
              PolyKind pkind = (sym.type.hasTag(FORALL) &&
                   sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
                   PolyKind.POLY : PolyKind.STANDALONE;
              TreeInfo.setPolyKind(env.tree, pkind);
  
              return (resultInfo.pt == Infer.anyPoly) ?
                      owntype :
                      chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
                              resultInfo.checkContext.inferenceContext());
          } catch (Infer.InferenceException ex) {
              //invalid target type - propagate exception outwards or report error
              //depending on the current check context
              resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
              return types.createErrorType(sym.type);
          } catch (Resolve.InapplicableMethodException ex) {
              final JCDiagnostic diag = ex.getDiagnostic();
              Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
                  @Override
                  protected Pair<Symbol, JCDiagnostic> errCandidate() {
                      return new Pair<>(sym, diag);
                  }
              };
              List<Type> argtypes2 = argtypes.map(
                      rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
              JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
                      env.tree, sym, site, sym.name, argtypes2, typeargtypes);
              log.report(errDiag);
              return types.createErrorType(site);
          }
      }
  
      public void visitLiteral(JCLiteral tree) {
          result = check(tree, litType(tree.typetag).constType(tree.value),
                  KindSelector.VAL, resultInfo);
      }
      //where
      /** Return the type of a literal with given type tag.
       */
      Type litType(TypeTag tag) {
          return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
      }
  
      public void visitTypeIdent(JCPrimitiveTypeTree tree) {
          result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
      }
  
      public void visitTypeArray(JCArrayTypeTree tree) {
          Type etype = attribType(tree.elemtype, env);
          Type type = new ArrayType(etype, syms.arrayClass);
          result = check(tree, type, KindSelector.TYP, resultInfo);
      }
  
      /** Visitor method for parameterized types.
       *  Bound checking is left until later, since types are attributed
       *  before supertype structure is completely known
       */
      public void visitTypeApply(JCTypeApply tree) {
          Type owntype = types.createErrorType(tree.type);
  
          // Attribute functor part of application and make sure it's a class.
          Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
  
          // Attribute type parameters
          List<Type> actuals = attribTypes(tree.arguments, env);
  
          if (clazztype.hasTag(CLASS)) {
              List<Type> formals = clazztype.tsym.type.getTypeArguments();
              if (actuals.isEmpty()) //diamond
                  actuals = formals;
  
              if (actuals.length() == formals.length()) {
                  List<Type> a = actuals;
                  List<Type> f = formals;
                  while (a.nonEmpty()) {
                      a.head = a.head.withTypeVar(f.head);
                      a = a.tail;
                      f = f.tail;
                  }
                  // Compute the proper generic outer
                  Type clazzOuter = clazztype.getEnclosingType();
                  if (clazzOuter.hasTag(CLASS)) {
                      Type site;
                      JCExpression clazz = TreeInfo.typeIn(tree.clazz);
                      if (clazz.hasTag(IDENT)) {
                          site = env.enclClass.sym.type;
                      } else if (clazz.hasTag(SELECT)) {
                          site = ((JCFieldAccess) clazz).selected.type;
                      } else throw new AssertionError(""+tree);
                      if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
                          if (site.hasTag(CLASS))
                              site = types.asOuterSuper(site, clazzOuter.tsym);
                          if (site == null)
                              site = types.erasure(clazzOuter);
                          clazzOuter = site;
                      }
                  }
                  owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
                                          clazztype.getMetadata());
              } else {
                  if (formals.length() != 0) {
                      log.error(tree.pos(),
                                Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
                  } else {
                      log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
                  }
                  owntype = types.createErrorType(tree.type);
              }
          }
          result = check(tree, owntype, KindSelector.TYP, resultInfo);
      }
  
      public void visitTypeUnion(JCTypeUnion tree) {
          ListBuffer<Type> multicatchTypes = new ListBuffer<>();
          ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
          for (JCExpression typeTree : tree.alternatives) {
              Type ctype = attribType(typeTree, env);
              ctype = chk.checkType(typeTree.pos(),
                            chk.checkClassType(typeTree.pos(), ctype),
                            syms.throwableType);
              if (!ctype.isErroneous()) {
                  //check that alternatives of a union type are pairwise
                  //unrelated w.r.t. subtyping
                  if (chk.intersects(ctype,  multicatchTypes.toList())) {
                      for (Type t : multicatchTypes) {
                          boolean sub = types.isSubtype(ctype, t);
                          boolean sup = types.isSubtype(t, ctype);
                          if (sub || sup) {
                              //assume 'a' <: 'b'
                              Type a = sub ? ctype : t;
                              Type b = sub ? t : ctype;
                              log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
                          }
                      }
                  }
                  multicatchTypes.append(ctype);
                  if (all_multicatchTypes != null)
                      all_multicatchTypes.append(ctype);
              } else {
                  if (all_multicatchTypes == null) {
                      all_multicatchTypes = new ListBuffer<>();
                      all_multicatchTypes.appendList(multicatchTypes);
                  }
                  all_multicatchTypes.append(ctype);
              }
          }
          Type t = check(tree, types.lub(multicatchTypes.toList()),
                  KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
          if (t.hasTag(CLASS)) {
              List<Type> alternatives =
                  ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
              t = new UnionClassType((ClassType) t, alternatives);
          }
          tree.type = result = t;
      }
  
      public void visitTypeIntersection(JCTypeIntersection tree) {
          attribTypes(tree.bounds, env);
          tree.type = result = checkIntersection(tree, tree.bounds);
      }
  
      public void visitTypeParameter(JCTypeParameter tree) {
          TypeVar typeVar = (TypeVar) tree.type;
  
          if (tree.annotations != null && tree.annotations.nonEmpty()) {
              annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
          }
  
          if (!typeVar.getUpperBound().isErroneous()) {
              //fixup type-parameter bound computed in 'attribTypeVariables'
              typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
          }
      }
  
      Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
          Set<Type> boundSet = new HashSet<>();
          if (bounds.nonEmpty()) {
              // accept class or interface or typevar as first bound.
              bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
              boundSet.add(types.erasure(bounds.head.type));
              if (bounds.head.type.isErroneous()) {
                  return bounds.head.type;
              }
              else if (bounds.head.type.hasTag(TYPEVAR)) {
                  // if first bound was a typevar, do not accept further bounds.
                  if (bounds.tail.nonEmpty()) {
                      log.error(bounds.tail.head.pos(),
                                Errors.TypeVarMayNotBeFollowedByOtherBounds);
                      return bounds.head.type;
                  }
              } else {
                  // if first bound was a class or interface, accept only interfaces
                  // as further bounds.
                  for (JCExpression bound : bounds.tail) {
                      bound.type = checkBase(bound.type, bound, env, false, true, false);
                      if (bound.type.isErroneous()) {
                          bounds = List.of(bound);
                      }
                      else if (bound.type.hasTag(CLASS)) {
                          chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
                      }
                  }
              }
          }
  
          if (bounds.length() == 0) {
              return syms.objectType;
          } else if (bounds.length() == 1) {
              return bounds.head.type;
          } else {
              Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
              // ... the variable's bound is a class type flagged COMPOUND
              // (see comment for TypeVar.bound).
              // In this case, generate a class tree that represents the
              // bound class, ...
              JCExpression extending;
              List<JCExpression> implementing;
              if (!bounds.head.type.isInterface()) {
                  extending = bounds.head;
                  implementing = bounds.tail;
              } else {
                  extending = null;
                  implementing = bounds;
              }
              JCClassDecl cd = make.at(tree).ClassDef(
                  make.Modifiers(PUBLIC | ABSTRACT),
                  names.empty, List.nil(),
                  extending, implementing, List.nil());
  
              ClassSymbol c = (ClassSymbol)owntype.tsym;
              Assert.check((c.flags() & COMPOUND) != 0);
              cd.sym = c;
              c.sourcefile = env.toplevel.sourcefile;
  
              // ... and attribute the bound class
              c.flags_field |= UNATTRIBUTED;
              Env<AttrContext> cenv = enter.classEnv(cd, env);
              typeEnvs.put(c, cenv);
              attribClass(c);
              return owntype;
          }
      }
  
      public void visitWildcard(JCWildcard tree) {
          //- System.err.println("visitWildcard("+tree+");");//DEBUG
          Type type = (tree.kind.kind == BoundKind.UNBOUND)
              ? syms.objectType
              : attribType(tree.inner, env);
          result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
                                                tree.kind.kind,
                                                syms.boundClass),
                  KindSelector.TYP, resultInfo);
      }
  
      public void visitAnnotation(JCAnnotation tree) {
          Assert.error("should be handled in annotate");
      }
  
      public void visitAnnotatedType(JCAnnotatedType tree) {
          attribAnnotationTypes(tree.annotations, env);
          Type underlyingType = attribType(tree.underlyingType, env);
          Type annotatedType = underlyingType.annotatedType(Annotations.TO_BE_SET);
  
          if (!env.info.isNewClass)
              annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
          result = tree.type = annotatedType;
      }
  
      public void visitErroneous(JCErroneous tree) {
  
          if (tree.errs != null) {
              Env<AttrContext> errEnv = env.dup(env.tree);
              errEnv.info.returnResult = unknownExprInfo;
  		for (JCTree err : tree.errs) {
  		        try {
                  		attribTree(err, errEnv, new ResultInfo(KindSelector.ERR, pt()));
  		        } catch (AssertionError ae) {
  		            //ignore
  		        }
  		    }
  
          }
  
          result = tree.type = syms.errType;
      }
  
      /** Default visitor method for all other trees.
       */
      public void visitTree(JCTree tree) {
          throw new AssertionError();
      }
  
      /**
       * Attribute an env for either a top level tree or class or module declaration.
       */
      public void attrib(Env<AttrContext> env) {
          switch (env.tree.getTag()) {
              case MODULEDEF:
                  attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
                  break;
              case TOPLEVEL:
                  attribTopLevel(env);
                  break;
              case PACKAGEDEF:
                  attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
                  break;
              default:
                  attribClass(env.tree.pos(), env.enclClass.sym);
          }
      }
  
      /**
       * Attribute a top level tree. These trees are encountered when the
       * package declaration has annotations.
       */
      public void attribTopLevel(Env<AttrContext> env) {
          JCCompilationUnit toplevel = env.toplevel;
          try {
              annotate.flush();
          } catch (CompletionFailure ex) {
              chk.completionError(toplevel.pos(), ex);
          }
      }
  
      public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
          try {
              annotate.flush();
              attribPackage(p);
          } catch (CompletionFailure ex) {
              chk.completionError(pos, ex);
          }
      }
  
      void attribPackage(PackageSymbol p) {
          Env<AttrContext> env = typeEnvs.get(p);
          chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p);
      }
  
      public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
          try {
              annotate.flush();
              attribModule(m);
          } catch (CompletionFailure ex) {
              chk.completionError(pos, ex);
          }
      }
  
      void attribModule(ModuleSymbol m) {
          // Get environment current at the point of module definition.
          Env<AttrContext> env = enter.typeEnvs.get(m);
          attribStat(env.tree, env);
      }
  
      /** Main method: attribute class definition associated with given class symbol.
       *  reporting completion failures at the given position.
       *  @param pos The source position at which completion errors are to be
       *             reported.
       *  @param c   The class symbol whose definition will be attributed.
       */
      public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
          try {
              annotate.flush();
              attribClass(c);
          } catch (CompletionFailure ex) {
              chk.completionError(pos, ex);
          }
      }
  
      /** Attribute class definition associated with given class symbol.
       *  @param c   The class symbol whose definition will be attributed.
       */
      void attribClass(ClassSymbol c) throws CompletionFailure {
  
  
          // Check for cycles in the inheritance graph, which can arise from
          // ill-formed class files.
          chk.checkNonCyclic(null, c.type);
  
          Type st = types.supertype(c.type);
          if ((c.flags_field & Flags.COMPOUND) == 0 &&
              (c.flags_field & Flags.SUPER_OWNER_ATTRIBUTED) == 0) {
              // First, attribute superclass.
              if (st.hasTag(CLASS))
                  attribClass((ClassSymbol)st.tsym);
  
              // Next attribute owner, if it is a class.
              if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
                  attribClass((ClassSymbol)c.owner);
  
              c.flags_field |= Flags.SUPER_OWNER_ATTRIBUTED;
          }
  
          // The previous operations might have attributed the current class
          // if there was a cycle. So we test first whether the class is still
          // UNATTRIBUTED.
          if ((c.flags_field & UNATTRIBUTED) != 0) {
              c.flags_field &= ~UNATTRIBUTED;
  
              // Get environment current at the point of class definition.
              Env<AttrContext> env = typeEnvs.get(c);
  
              if (c.isSealed() &&
                      !c.isEnum() &&
                      !c.isPermittedExplicit &&
                      c.permitted.isEmpty()) {
                  log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.SealedClassMustHaveSubclasses);
              }
  
              if (c.isSealed()) {
                  Set<Symbol> permittedTypes = new HashSet<>();
                  boolean sealedInUnnamed = c.packge().modle == syms.unnamedModule || c.packge().modle == syms.noModule;
                  for (Symbol subTypeSym : c.permitted) {
                      boolean isTypeVar = false;
                      if (subTypeSym.type.getTag() == TYPEVAR) {
                          isTypeVar = true; //error recovery
                          log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
                                  Errors.InvalidPermitsClause(Fragments.IsATypeVariable(subTypeSym.type)));
                      }
                      if (subTypeSym.isAnonymous() && !c.isEnum()) {
                          log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),  Errors.LocalClassesCantExtendSealed(Fragments.Anonymous));
                      }
                      if (permittedTypes.contains(subTypeSym)) {
                          DiagnosticPosition pos =
                                  env.enclClass.permitting.stream()
                                          .filter(permittedExpr -> TreeInfo.diagnosticPositionFor(subTypeSym, permittedExpr, true) != null)
                                          .limit(2).collect(List.collector()).get(1);
                          log.error(pos, Errors.InvalidPermitsClause(Fragments.IsDuplicated(subTypeSym.type)));
                      } else {
                          permittedTypes.add(subTypeSym);
                      }
                      if (sealedInUnnamed) {
                          if (subTypeSym.packge() != c.packge()) {
                              log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
                                      Errors.ClassInUnnamedModuleCantExtendSealedInDiffPackage(c)
                              );
                          }
                      } else if (subTypeSym.packge().modle != c.packge().modle) {
                          log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
                                  Errors.ClassInModuleCantExtendSealedInDiffModule(c, c.packge().modle)
                          );
                      }
                      if (subTypeSym == c.type.tsym || types.isSuperType(subTypeSym.type, c.type)) {
                          log.error(TreeInfo.diagnosticPositionFor(subTypeSym, ((JCClassDecl)env.tree).permitting),
                                  Errors.InvalidPermitsClause(
                                          subTypeSym == c.type.tsym ?
                                                  Fragments.MustNotBeSameClass :
                                                  Fragments.MustNotBeSupertype(subTypeSym.type)
                                  )
                          );
                      } else if (!isTypeVar) {
                          boolean thisIsASuper = types.directSupertypes(subTypeSym.type)
                                                      .stream()
                                                      .anyMatch(d -> d.tsym == c);
                          if (!thisIsASuper) {
                              log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
                                      Errors.InvalidPermitsClause(Fragments.DoesntExtendSealed(subTypeSym.type)));
                          }
                      }
                  }
              }
  
              List<ClassSymbol> sealedSupers = types.directSupertypes(c.type)
                                                    .stream()
                                                    .filter(s -> s.tsym.isSealed())
                                                    .map(s -> (ClassSymbol) s.tsym)
                                                    .collect(List.collector());
  
              if (sealedSupers.isEmpty()) {
                  if ((c.flags_field & Flags.NON_SEALED) != 0) {
                      boolean hasErrorSuper = types.directSupertypes(c.type)
                                                   .stream()
                                                   .anyMatch(s -> s.tsym.kind == Kind.ERR);
                      if (!hasErrorSuper) {
                          log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.NonSealedWithNoSealedSupertype(c));
                      }
                  }
              } else {
                  if (c.isDirectlyOrIndirectlyLocal() && !c.isEnum()) {
                      log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.LocalClassesCantExtendSealed(c.isAnonymous() ? Fragments.Anonymous : Fragments.Local));
                  }
  
                  if (!c.type.isCompound()) {
                      for (ClassSymbol supertypeSym : sealedSupers) {
                          if (!supertypeSym.permitted.contains(c.type.tsym)) {
                              log.error(TreeInfo.diagnosticPositionFor(c.type.tsym, env.tree), Errors.CantInheritFromSealed(supertypeSym));
                          }
                      }
                      if (!c.isNonSealed() && !c.isFinal() && !c.isSealed()) {
                          log.error(TreeInfo.diagnosticPositionFor(c, env.tree),
                                  c.isInterface() ?
                                          Errors.NonSealedOrSealedExpected :
                                          Errors.NonSealedSealedOrFinalExpected);
                      }
                  }
              }
  
              if (env == null) {
                  return;
              }
  
              // The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
              // because the annotations were not available at the time the env was created. Therefore,
              // we look up the environment chain for the first enclosing environment for which the
              // lint value is set. Typically, this is the parent env, but might be further if there
              // are any envs created as a result of TypeParameter nodes.
              Env<AttrContext> lintEnv = env;
              while (lintEnv.info.lint == null)
                  lintEnv = lintEnv.next;
  
              // Having found the enclosing lint value, we can initialize the lint value for this class
              env.info.lint = lintEnv.info.lint.augment(c);
  
              Lint prevLint = chk.setLint(env.info.lint);
              JavaFileObject prev = log.useSource(c.sourcefile);
              ResultInfo prevReturnRes = env.info.returnResult;
  
              try {
                  deferredLintHandler.flush(env.tree);
                  env.info.returnResult = null;
                  // java.lang.Enum may not be subclassed by a non-enum
                  if (st.tsym == syms.enumSym &&
                      ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
                      log.error(env.tree.pos(), Errors.EnumNoSubclassing);
  
                  // Enums may not be extended by source-level classes
                  if (st.tsym != null &&
                      ((st.tsym.flags_field & Flags.ENUM) != 0) &&
                      ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
                      log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
                  }
  
                  if (isSerializable(c.type)) {
                      env.info.isSerializable = true;
                  }
  
                  attribClassBody(env, c);
  
                  deferredLintHandler.flush(env.tree.pos());
                  chk.checkDeprecatedAnnotation(env.tree.pos(), c);
                  chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
                  chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
                  chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
              } finally {
                  env.info.returnResult = prevReturnRes;
                  log.useSource(prev);
                  chk.setLint(prevLint);
              }
  
          }
      }
  
      public void visitImport(JCImport tree) {
          // nothing to do
      }
  
      public void visitModuleDef(JCModuleDecl tree) {
          tree.sym.completeUsesProvides();
          ModuleSymbol msym = tree.sym;
          Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
          Lint prevLint = chk.setLint(lint);
          chk.checkModuleName(tree);
          chk.checkDeprecatedAnnotation(tree, msym);
  
          try {
              deferredLintHandler.flush(tree.pos());
          } finally {
              chk.setLint(prevLint);
          }
      }
  
      /** Finish the attribution of a class. */
      private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
          JCClassDecl tree = (JCClassDecl)env.tree;
  
          if (c != tree.sym)
              Assert.error("c = " + c + " tree.sym = " + tree.sym + " tree = " + tree);
  
          // Validate type parameters, supertype and interfaces.
          attribStats(tree.typarams, env);
          if (!c.isAnonymous()) {
              //already checked if anonymous
              chk.validate(tree.typarams, env);
              chk.validate(tree.extending, env);
              chk.validate(tree.implementing, env);
          }
  
          c.markAbstractIfNeeded(types);
  
          // If this is a non-abstract class, check that it has no abstract
          // methods or unimplemented methods of an implemented interface.
          if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
              chk.checkAllDefined(tree.pos(), c);
          }
  
          if ((c.flags() & ANNOTATION) != 0) {
              if (tree.implementing.nonEmpty())
                  log.error(tree.implementing.head.pos(),
                            Errors.CantExtendIntfAnnotation);
              if (tree.typarams.nonEmpty()) {
                  log.error(tree.typarams.head.pos(),
                            Errors.IntfAnnotationCantHaveTypeParams(c));
              }
  
              // If this annotation type has a @Repeatable, validate
              Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
              // If this annotation type has a @Repeatable, validate
              if (repeatable != null) {
                  // get diagnostic position for error reporting
                  DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
                  Assert.checkNonNull(cbPos);
  
                  chk.validateRepeatable(c, repeatable, cbPos);
              }
          } else {
              // Check that all extended classes and interfaces
              // are compatible (i.e. no two define methods with same arguments
              // yet different return types).  (JLS 8.4.6.3)
              chk.checkCompatibleSupertypes(tree.pos(), c.type);
              if (allowDefaultMethods) {
                  chk.checkDefaultMethodClashes(tree.pos(), c.type);
              }
          }
  
          // Check that class does not import the same parameterized interface
          // with two different argument lists.
          chk.checkClassBounds(tree.pos(), c.type);
  
          tree.type = c.type;
  
          for (List<JCTypeParameter> l = tree.typarams;
               l.nonEmpty(); l = l.tail) {
               Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
          }
  
          // Check that a generic class doesn't extend Throwable
          if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
              log.error(tree.extending.pos(), Errors.GenericThrowable);
  
          // Check that all methods which implement some
          // method conform to the method they implement.
          DiagnosticPosition prevPos = deferredLintHandler.setPos(tree.pos());
          try {
              chk.checkImplementations(tree);
          } finally {
              deferredLintHandler.setPos(prevPos);
          }
  
          //check that a resource implementing AutoCloseable cannot throw InterruptedException
          checkAutoCloseable(tree.pos(), env, c.type);
  
          for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
              // Attribute declaration
              attribStat(l.head, env);
              // Check that declarations in inner classes are not static (JLS 8.1.2)
              // Make an exception for static constants.
              if (!allowRecords &&
                      c.owner.kind != PCK &&
                      ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
                      (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
                  Symbol sym = null;
                  if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
                  if (sym == null ||
  
                      sym.kind != VAR ||
                      ((VarSymbol) sym).getConstValue() == null) {
                      // Check that enum type is not local. If so, 'Enum types must not be local' is already reported
                      // and there is no need for reporting static declaration in an inner class
                      if (c.owner.kind != MTH || (c.flags() & ENUM) == 0)
                          log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
                  }               
              }
          }
  
          // Check for cycles among non-initial constructors.
          chk.checkCyclicConstructors(tree);
  
          // Check for cycles among annotation elements.
          chk.checkNonCyclicElements(tree);
  
          // Check for proper use of serialVersionUID
          if (env.info.lint.isEnabled(LintCategory.SERIAL)
                  && isSerializable(c.type)
                  && (c.flags() & (Flags.ENUM | Flags.INTERFACE)) == 0
                  && !c.isAnonymous()) {
              checkSerialVersionUID(tree, c, env);
          }
          if (allowTypeAnnos) {
              // Correctly organize the positions of the type annotations
              typeAnnotations.organizeTypeAnnotationsBodies(tree);
  
              // Check type annotations applicability rules
              validateTypeAnnotations(tree, false);
          }
      }
          // where
          /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
          private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
              for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
                  if (types.isSameType(al.head.annotationType.type, t))
                      return al.head.pos();
              }
  
              return null;
          }
  
          /** check if a type is a subtype of Serializable, if that is available. */
          boolean isSerializable(Type t) {
              try {
                  syms.serializableType.complete();
              }
              catch (CompletionFailure e) {
                  return false;
              }
              return types.isSubtype(t, syms.serializableType);
          }
  
          /** Check that an appropriate serialVersionUID member is defined. */
          private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c, Env<AttrContext> env) {
  
              // check for presence of serialVersionUID
              VarSymbol svuid = null;
              for (Symbol sym : c.members().getSymbolsByName(names.serialVersionUID)) {
                  if (sym.kind == VAR) {
                      svuid = (VarSymbol)sym;
                      break;
                  }
              }
  
              if (svuid == null) {
                  if (!c.isRecord())
                      log.warning(LintCategory.SERIAL, tree.pos(), Warnings.MissingSVUID(c));
                  return;
              }
  
              // Check if @SuppressWarnings("serial") is an annotation of serialVersionUID.
              // See JDK-8231622 for more information.
              Lint lint = env.info.lint.augment(svuid);
              if (lint.isSuppressed(LintCategory.SERIAL)) {
                  return;
              }
  
              // check that it is static final
              if ((svuid.flags() & (STATIC | FINAL)) !=
                  (STATIC | FINAL))
                  log.warning(LintCategory.SERIAL,
                          TreeInfo.diagnosticPositionFor(svuid, tree), Warnings.ImproperSVUID(c));
  
              // check that it is long
              else if (!svuid.type.hasTag(LONG))
                  log.warning(LintCategory.SERIAL,
                          TreeInfo.diagnosticPositionFor(svuid, tree), Warnings.LongSVUID(c));
  
              // check constant
              else if (svuid.getConstValue() == null)
                  log.warning(LintCategory.SERIAL,
                          TreeInfo.diagnosticPositionFor(svuid, tree), Warnings.ConstantSVUID(c));
          }
  
      private Type capture(Type type) {
          return types.capture(type);
      }
  
      private void setSyntheticVariableType(JCVariableDecl tree, Type type) {
          if (type.isErroneous()) {
              tree.vartype = make.at(Position.NOPOS).Erroneous();
          } else {
              tree.vartype = make.at(Position.NOPOS).Type(type);
          }
      }
  
      public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
          tree.accept(new TypeAnnotationsValidator(sigOnly));
      }
      //where
      private final class TypeAnnotationsValidator extends TreeScanner {
  
          private final boolean sigOnly;
          public TypeAnnotationsValidator(boolean sigOnly) {
              this.sigOnly = sigOnly;
          }
  
          public void visitAnnotation(JCAnnotation tree) {
              chk.validateTypeAnnotation(tree, false);
              super.visitAnnotation(tree);
          }
          public void visitAnnotatedType(JCAnnotatedType tree) {
              if (!tree.underlyingType.type.isErroneous()) {
                  super.visitAnnotatedType(tree);
              }
          }
          public void visitTypeParameter(JCTypeParameter tree) {
              chk.validateTypeAnnotations(tree.annotations, true);
              scan(tree.bounds);
              // Don't call super.
              // This is needed because above we call validateTypeAnnotation with
              // false, which would forbid annotations on type parameters.
              // super.visitTypeParameter(tree);
          }
          public void visitMethodDef(JCMethodDecl tree) {
              if (tree.recvparam != null &&
                      !tree.recvparam.vartype.type.isErroneous()) {
                  checkForDeclarationAnnotations(tree.recvparam.mods.annotations, tree.recvparam.sym);
              }
              if (tree.restype != null && tree.restype.type != null) {
                  validateAnnotatedType(tree.restype, tree.restype.type);
              }
              if (sigOnly) {
                  scan(tree.mods);
                  scan(tree.restype);
                  scan(tree.typarams);
                  scan(tree.recvparam);
                  scan(tree.params);
                  scan(tree.thrown);
              } else {
                  scan(tree.defaultValue);
                  scan(tree.body);
              }
          }
          public void visitVarDef(final JCVariableDecl tree) {
              //System.err.println("validateTypeAnnotations.visitVarDef " + tree);
              if (tree.sym != null && tree.sym.type != null && !tree.sym.type.isErroneous() && !tree.isImplicitlyTyped())
                  validateAnnotatedType(tree.vartype, tree.sym.type);
              scan(tree.mods);
              scan(tree.vartype);
              if (!sigOnly) {
                  scan(tree.init);
              }
          }
          public void visitTypeCast(JCTypeCast tree) {
              if (tree.clazz != null && tree.clazz.type != null)
                  validateAnnotatedType(tree.clazz, tree.clazz.type);
              super.visitTypeCast(tree);
          }
          public void visitTypeTest(JCInstanceOf tree) {
              if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
                  validateAnnotatedType(tree.pattern, tree.pattern.type);
              super.visitTypeTest(tree);
          }
          public void visitNewClass(JCNewClass tree) {
              if (tree.clazz != null && tree.clazz.type != null) {
                  if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
                      checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
                              tree.clazz.type.tsym);
                  }
                  if (tree.def != null) {
                      checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
                  }
  
                  validateAnnotatedType(tree.clazz, tree.clazz.type);
              }
              super.visitNewClass(tree);
          }
          public void visitNewArray(JCNewArray tree) {
              if (tree.elemtype != null && tree.elemtype.type != null) {
                  if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
                      checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
                              tree.elemtype.type.tsym);
                  }
                  validateAnnotatedType(tree.elemtype, tree.elemtype.type);
              }
              super.visitNewArray(tree);
          }
          public void visitClassDef(JCClassDecl tree) {
              //System.err.println("validateTypeAnnotations.visitClassDef " + tree);
              if (sigOnly) {
                  scan(tree.mods);
                  scan(tree.typarams);
                  scan(tree.extending);
                  scan(tree.implementing);
              }
              for (JCTree member : tree.defs) {
                  if (member.hasTag(Tag.CLASSDEF)) {
                      continue;
                  }
                  scan(member);
              }
          }
          public void visitBlock(JCBlock tree) {
              if (!sigOnly) {
                  scan(tree.stats);
              }
          }
  
          /* I would want to model this after
           * openjdk.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
           * and override visitSelect and visitTypeApply.
           * However, we only set the annotated type in the top-level type
           * of the symbol.
           * Therefore, we need to override each individual location where a type
           * can occur.
           */
          private void validateAnnotatedType(final JCTree errtree, final Type type) {
              //System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
  
              if (type.isPrimitiveOrVoid() || type.isErroneous()) {
                  return;
              }
  
              JCTree enclTr = errtree;
              Type enclTy = type;
  
              boolean repeat = true;
              while (repeat) {
                  if (enclTr == null) {
                      Assert.error("Unexpected null tree within: "+ errtree + " with kind: " + errtree.getKind());
                  }
                  if (enclTr.hasTag(TYPEAPPLY)) {
                      List<Type> tyargs = enclTy.getTypeArguments();
                      List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
                      if (trargs.length() > 0) {
                          // Nothing to do for diamonds
                          if (tyargs.length() == trargs.length()) {
                              for (int i = 0; i < tyargs.length(); ++i) {
                                  validateAnnotatedType(trargs.get(i), tyargs.get(i));
                              }
                          }
                          // If the lengths don't match, it's either a diamond
                          // or some nested type that redundantly provides
                          // type arguments in the tree.
                      }
  
                      // Look at the clazz part of a generic type
                      enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
                  }
  
                  if (enclTr.hasTag(SELECT)) {
                      enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
                      if (enclTy != null &&
                              !enclTy.hasTag(NONE)) {
                          enclTy = enclTy.getEnclosingType();
                      }
                  } else if (enclTr.hasTag(ANNOTATED_TYPE)) {
                      JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
                      if (enclTy == null || enclTy.hasTag(NONE)) {
                          if (at.getAnnotations().size() == 1) {
                              log.error(at.underlyingType.pos(), Errors.CantTypeAnnotateScoping1(at.getAnnotations().head.attribute));
                          } else {
                              ListBuffer<Attribute.Compound> comps = new ListBuffer<>();
                              for (JCAnnotation an : at.getAnnotations()) {
                                  comps.add(an.attribute);
                              }
                              log.error(at.underlyingType.pos(), Errors.CantTypeAnnotateScoping(comps.toList()));
                          }
                          repeat = false;
                      }
                      enclTr = at.underlyingType;
                      // enclTy doesn't need to be changed
                  } else if (enclTr.hasTag(IDENT)) {
                      repeat = false;
                  } else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
                      JCWildcard wc = (JCWildcard) enclTr;
                      if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
                              wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
                          validateAnnotatedType(wc.getBound(), wc.getBound().type);
                      } else {
                          // Nothing to do for UNBOUND
                      }
                      repeat = false;
                  } else if (enclTr.hasTag(TYPEARRAY)) {
                      JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
                      validateAnnotatedType(art.getType(), art.elemtype.type);
                      repeat = false;
                  } else if (enclTr.hasTag(TYPEUNION)) {
                      JCTypeUnion ut = (JCTypeUnion) enclTr;
                      for (JCTree t : ut.getTypeAlternatives()) {
                          validateAnnotatedType(t, t.type);
                      }
                      repeat = false;
                  } else if (enclTr.hasTag(TYPEINTERSECTION)) {
                      JCTypeIntersection it = (JCTypeIntersection) enclTr;
                      for (JCTree t : it.getBounds()) {
                          validateAnnotatedType(t, t.type);
                      }
                      repeat = false;
                  } else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
                             enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
                      repeat = false;
                  } else if (enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
                      repeat = false;
                  } else {
                      Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
                              " within: "+ errtree + " with kind: " + errtree.getKind());
                  }
              }
          }
  
          private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
                  Symbol sym) {
              // Ensure that no declaration annotations are present.
              // Note that a tree type might be an AnnotatedType with
              // empty annotations, if only declaration annotations were given.
              // This method will raise an error for such a type.
              for (JCAnnotation ai : annotations) {
                  if (!ai.type.isErroneous() &&
                          typeAnnotations.annotationTargetType(ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
                      log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
                  }
              }
          }
      }
  
      public Env<AttrContext> dupLocalEnv(Env<AttrContext> localEnv) {
          return localEnv.dup(localEnv.tree, localEnv.info.dup(localEnv.info.scope.dupUnshared()));
      }
  
  // <editor-fold desc="post-attribution visitor">
  
      /**
       * Handle missing types/symbols in an AST. This routine is useful when
       * the compiler has encountered some errors (which might have ended up
       * terminating attribution abruptly); if the compiler is used in fail-over
       * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
       * prevents NPE to be propagated during subsequent compilation steps.
       */
      public void postAttr(JCTree tree) {
          new PostAttrAnalyzer().scan(tree);
      }
  
      class PostAttrAnalyzer extends TreeScanner {
  
          private void initTypeIfNeeded(JCTree that) {
              if (that.type == null) {
                  if (that.hasTag(METHODDEF)) {
                      that.type = dummyMethodType((JCMethodDecl)that);
                  } else {
                      that.type = syms.unknownType;
                  }
              }
          }
  
          /* Construct a dummy method type. If we have a method declaration,
           * and the declared return type is void, then use that return type
           * instead of UNKNOWN to avoid spurious error messages in lambda
           * bodies (see:JDK-8041704).
           */
          private Type dummyMethodType(JCMethodDecl md) {
              Type restype = syms.unknownType;
              if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
                  JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
                  if (prim.typetag == VOID)
                      restype = syms.voidType;
              }
              return new MethodType(List.nil(), restype,
                                    List.nil(), syms.methodClass);
          }
          private Type dummyMethodType() {
              return dummyMethodType(null);
          }
  
          @Override
          public void scan(JCTree tree) {
              if (tree == null) return;
              if (tree instanceof JCExpression) {
                  initTypeIfNeeded(tree);
              }
              super.scan(tree);
          }
  
          @Override
          public void visitIdent(JCIdent that) {
              if (that.sym == null) {
                  that.sym = syms.unknownSymbol;
              }
          }
  
          @Override
          public void visitSelect(JCFieldAccess that) {
              if (that.sym == null) {
                  that.sym = syms.unknownSymbol;
              }
              super.visitSelect(that);
          }
  
          @Override
          public void visitClassDef(JCClassDecl that) {
              initTypeIfNeeded(that);
              if (that.sym == null) {
                  that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
              }
              super.visitClassDef(that);
          }
  
          private boolean inMethodParams = false;
  
          @Override
          public void visitMethodDef(JCMethodDecl that) {
              initTypeIfNeeded(that);
              if (that.sym == null) {
                  that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
              }
              scan(that.mods);
              scan(that.restype);
              scan(that.typarams);
              try {
                  inMethodParams = true;
                  scan(that.recvparam);
                  scan(that.params);
              } finally {
                  inMethodParams = false;
              }
              scan(that.thrown);
              scan(that.defaultValue);
              scan(that.body);
          }
  
          @Override
          public void visitVarDef(JCVariableDecl that) {
              initTypeIfNeeded(that);
              if (that.sym == null) {
                  that.sym = new VarSymbol(inMethodParams ? Flags.PARAMETER : 0, that.name, that.type, syms.noSymbol);
                  that.sym.adr = 0;
              }
              if (that.vartype == null) {
                  that.vartype = make.at(Position.NOPOS).Erroneous();
              }
              super.visitVarDef(that);
          }
  
          @Override
          public void visitBindingPattern(JCBindingPattern that) {
              if (that.var.sym == null) {
                  that.var.sym = new BindingSymbol(0, that.var.name, that.var.type, syms.noSymbol);
                  that.var.sym.adr = 0;
              }
              super.visitBindingPattern(that);
          }
  
          @Override
          public void visitNewClass(JCNewClass that) {
              if (that.constructor == null) {
                  that.constructor = new MethodSymbol(0, names.init,
                          dummyMethodType(), syms.noSymbol);
              }
              if (that.constructorType == null) {
                  that.constructorType = syms.unknownType;
              }
              super.visitNewClass(that);
          }
  
          @Override
          public void visitAssignop(JCAssignOp that) {
              if (that.operator == null) {
                  that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
                          -1, syms.noSymbol);
              }
              super.visitAssignop(that);
          }
  
          @Override
          public void visitBinary(JCBinary that) {
              if (that.operator == null) {
                  that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
                          -1, syms.noSymbol);
              }
              super.visitBinary(that);
          }
  
          @Override
          public void visitUnary(JCUnary that) {
              if (that.operator == null) {
                  that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
                          -1, syms.noSymbol);
              }
              super.visitUnary(that);
          }
  
          @Override
          public void visitReference(JCMemberReference that) {
              super.visitReference(that);
              if (that.sym == null) {
                  that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
                          syms.noSymbol);
              }
          }
  
          @Override
          public void visitErroneous(JCErroneous tree) {
              scan(tree.errs);
          }
      }
      // </editor-fold>
  
      public void setPackageSymbols(JCExpression pid, Symbol pkg) {
          new TreeScanner() {
              Symbol packge = pkg;
              @Override
              public void visitIdent(JCIdent that) {
                  that.sym = packge;
              }
  
              @Override
              public void visitSelect(JCFieldAccess that) {
                  that.sym = packge;
                  packge = packge.owner;
                  super.visitSelect(that);
              }
          }.scan(pid);
      }
  
  }
  