internal ExecutableCodeBinder(CSharpSyntaxNode root, Symbol memberSymbol, Binder next, BinderFlags additionalFlags)
     : base(next, (next.Flags | additionalFlags) & ~BinderFlags.AllClearedAtExecutableCodeBoundary)
 {
     this.memberSymbol = memberSymbol;
     this.root = root;
     this.owner = memberSymbol as MethodSymbol;
 }

            internal BinderWithConditionalReceiver(Binder next, BoundExpression receiverExpression)
                : base(next)
            {
                Debug.Assert(receiverExpression != null);

                _receiverExpression = receiverExpression;
            }

        protected override void LookupSymbolsInSingleBinder(
            LookupResult result, string name, int arity, ConsList<Symbol> basesBeingResolved, LookupOptions options, Binder originalBinder, bool diagnose, ref HashSet<DiagnosticInfo> useSiteDiagnostics)
        {
            if ((options & (LookupOptions.NamespaceAliasesOnly | LookupOptions.MustBeInvocableIfMember)) != 0)
            {
                return;
            }

            Debug.Assert(result.IsClear);

            var count = parameterMap.GetCountForKey(name);
            if (count == 1)
            {
                ParameterSymbol p;
                parameterMap.TryGetSingleValue(name, out p);
                result.MergeEqual(originalBinder.CheckViability(p, arity, options, null, diagnose, ref useSiteDiagnostics));
            }
            else if (count > 1)
            {
                var parameters = parameterMap[name];
                foreach (var sym in parameters)
                {
                    result.MergeEqual(originalBinder.CheckViability(sym, arity, options, null, diagnose, ref useSiteDiagnostics));
                }
            }
        }

 public QueryUnboundLambdaState(UnboundLambda unbound, Binder binder, RangeVariableMap rangeVariableMap, ImmutableArray<RangeVariableSymbol> parameters, ExpressionSyntax body)
     : this(unbound, binder, rangeVariableMap, parameters, (LambdaSymbol lambdaSymbol, ref Binder lambdaBodyBinder, DiagnosticBag diagnostics) =>
 {
     lambdaBodyBinder = new ScopedExpressionBinder(lambdaBodyBinder, body);
     return lambdaBodyBinder.BindLambdaExpressionAsBlock(body, diagnostics);
 })
 { }

 public QueryUnboundLambdaState(UnboundLambda unbound, Binder binder, RangeVariableMap rangeVariableMap, ImmutableArray<RangeVariableSymbol> parameters, ExpressionSyntax body)
     : this(unbound, binder, rangeVariableMap, parameters, (LambdaSymbol lambdaSymbol, ExecutableCodeBinder lambdaBodyBinder, DiagnosticBag diagnostics) =>
 {
     BoundExpression expression = lambdaBodyBinder.BindValue(body, diagnostics, BindValueKind.RValue);
     return lambdaBodyBinder.WrapExpressionLambdaBody(expression, body, diagnostics);
 })
 { }

            internal BinderWithContainingMemberOrLambda(Binder next, BinderFlags flags, Symbol containingMemberOrLambda)
                : base(next, flags)
            {
                Debug.Assert(containingMemberOrLambda != null);

                _containingMemberOrLambda = containingMemberOrLambda;
            }

 internal Binder(Binder next)
 {
     Debug.Assert(next != null);
     _next = next;
     this.Flags = next.Flags;
     this.Compilation = next.Compilation;
 }

 public WithConstructorInitializerLocalsBinder(Binder enclosing, ConstructorDeclarationSyntax declaration)
     : base(enclosing, enclosing.Flags)
 {
     Debug.Assert(declaration.Initializer != null);
     this.scope = declaration;
     this.initializerArgumentList = declaration.Initializer.ArgumentList;
 }

        internal void CollectLocalsFromDeconstruction(
            ExpressionSyntax declaration,
            LocalDeclarationKind kind,
            ArrayBuilder<LocalSymbol> locals,
            SyntaxNode deconstructionStatement,
            Binder enclosingBinderOpt = null)
        {
            switch (declaration.Kind())
            {
                case SyntaxKind.TupleExpression:
                    {
                        var tuple = (TupleExpressionSyntax)declaration;
                        foreach (var arg in tuple.Arguments)
                        {
                            CollectLocalsFromDeconstruction(arg.Expression, kind, locals, deconstructionStatement, enclosingBinderOpt);
                        }
                        break;
                    }
                case SyntaxKind.DeclarationExpression:
                    {
                        var declarationExpression = (DeclarationExpressionSyntax)declaration;
                        CollectLocalsFromDeconstruction(
                            declarationExpression.Designation, declarationExpression.Type,
                            kind, locals, deconstructionStatement, enclosingBinderOpt);

                        break;
                    }
                case SyntaxKind.IdentifierName:
                    break;
                default:
                    throw ExceptionUtilities.UnexpectedValue(declaration.Kind());
            }
        }

        public BoundLambda(CSharpSyntaxNode syntax, BoundBlock body, ImmutableArray<Diagnostic> diagnostics, Binder binder, TypeSymbol delegateType, bool inferReturnType)
            : this(syntax, (LambdaSymbol)binder.ContainingMemberOrLambda, body, diagnostics, binder, delegateType)
        {
            if (inferReturnType)
            {
                this._inferredReturnType = InferReturnType(
                    this.Body,
                    this.Binder,
                    delegateType,
                    this.Symbol.IsAsync,
                    ref this._inferredReturnTypeUseSiteDiagnostics,
                    out this._refKind,
                    out this._inferredFromSingleType);

#if DEBUG
                _hasInferredReturnType = true;
#endif
            }

            Debug.Assert(
                syntax.IsAnonymousFunction() ||                                                                 // lambda expressions
                syntax is ExpressionSyntax && LambdaUtilities.IsLambdaBody(syntax, allowReducedLambdas: true) || // query lambdas
                LambdaUtilities.IsQueryPairLambda(syntax)                                                       // "pair" lambdas in queries
            );
        }

 public static SmallDictionary<CSharpSyntaxNode, Binder> BuildMap(MethodSymbol method, CSharpSyntaxNode syntax, Binder enclosing, out bool sawYield)
 {
     var builder = new LocalBinderFactory(method, enclosing);
     builder.Visit(syntax);
     sawYield = builder._sawYield;
     return builder._map;
 }

 public QueryUnboundLambdaState(Binder binder, RangeVariableMap rangeVariableMap, ImmutableArray<RangeVariableSymbol> parameters, LambdaBodyFactory bodyFactory)
     : base(binder, unboundLambdaOpt: null)
 {
     _parameters = parameters;
     _rangeVariableMap = rangeVariableMap;
     _bodyFactory = bodyFactory;
 }

        internal WithPrimaryConstructorParametersBinder(MethodSymbol primaryCtor, Binder next)
            : base(next)
        {
            Debug.Assert((object)primaryCtor != null);
            this.primaryCtor = primaryCtor;
            var parameters = primaryCtor.Parameters;

            var definitionMap = new SmallDictionary<string, ParameterSymbol>();

            for (int i = parameters.Length - 1; i >= 0; i--)
            {
                var parameter = parameters[i];
                definitionMap[parameter.Name] = parameter;
            }

            this.definitionMap = definitionMap;

            var parameterMap = new MultiDictionary<string, ParameterSymbol>(parameters.Length, EqualityComparer<string>.Default);

            foreach (var parameter in parameters)
            {
                parameterMap.Add(parameter.Name, parameter);
            }

            this.parameterMap = parameterMap;
        }

        internal override BoundStatement BindLockStatementParts(DiagnosticBag diagnostics, Binder originalBinder)
        {
            // Allow method groups during binding and then rule them out when we check that the expression has
            // a reference type.
            ExpressionSyntax exprSyntax = TargetExpressionSyntax;
            BoundExpression expr = BindTargetExpression(diagnostics);
            TypeSymbol exprType = expr.Type;

            bool hasErrors = false;

            if ((object)exprType == null)
            {
                if (expr.ConstantValue != ConstantValue.Null || Compilation.FeatureStrictEnabled) // Dev10 allows the null literal.
                {
                    Error(diagnostics, ErrorCode.ERR_LockNeedsReference, exprSyntax, expr.Display);
                    hasErrors = true;
                }
            }
            else if (!exprType.IsReferenceType && (exprType.IsValueType || Compilation.FeatureStrictEnabled))
            {
                Error(diagnostics, ErrorCode.ERR_LockNeedsReference, exprSyntax, exprType);
                hasErrors = true;
            }

            BoundStatement stmt = originalBinder.BindPossibleEmbeddedStatement(_syntax.Statement, diagnostics);
            Debug.Assert(this.Locals.IsDefaultOrEmpty);
            return new BoundLockStatement(_syntax, expr, stmt, hasErrors);
        }

        internal void CollectLocalsFromDeconstruction(
            ExpressionSyntax declaration,
            LocalDeclarationKind kind,
            ArrayBuilder<LocalSymbol> locals,
            SyntaxNode deconstructionStatement,
            Binder enclosingBinderOpt = null)
        {
            switch (declaration.Kind())
            {
                case SyntaxKind.TupleExpression:
                    {
                        var tuple = (TupleExpressionSyntax)declaration;
                        foreach (var arg in tuple.Arguments)
                        {
                            CollectLocalsFromDeconstruction(arg.Expression, kind, locals, deconstructionStatement, enclosingBinderOpt);
                        }
                        break;
                    }
                case SyntaxKind.DeclarationExpression:
                    {
                        var declarationExpression = (DeclarationExpressionSyntax)declaration;
                        CollectLocalsFromDeconstruction(
                            declarationExpression.Designation, declarationExpression.Type,
                            kind, locals, deconstructionStatement, enclosingBinderOpt);

                        break;
                    }
                case SyntaxKind.IdentifierName:
                    break;
                default:
                    // In broken code, we can have an arbitrary expression here. Collect its expression variables.
                    ExpressionVariableFinder.FindExpressionVariables(this, locals, declaration);
                    break;
            }
        }

        private BoundForStatement BindForParts(ForStatementSyntax node, Binder originalBinder, DiagnosticBag diagnostics)
        {
            BoundStatement initializer;
            if (node.Declaration != null)
            {
                Debug.Assert(node.Initializers.Count == 0);
                if (node.Declaration.IsDeconstructionDeclaration)
                {
                    initializer = originalBinder.BindDeconstructionDeclaration(node.Declaration, node.Declaration, diagnostics);
                }
                else
                {
                    ImmutableArray<BoundLocalDeclaration> unused;
                    initializer = originalBinder.BindForOrUsingOrFixedDeclarations(node.Declaration, LocalDeclarationKind.ForInitializerVariable, diagnostics, out unused);
                }
            }
            else
            {
                initializer = originalBinder.BindStatementExpressionList(node.Initializers, diagnostics);
            }

            var condition = (node.Condition != null) ? originalBinder.BindBooleanExpression(node.Condition, diagnostics) : null;
            var increment = originalBinder.BindStatementExpressionList(node.Incrementors, diagnostics);
            var body = originalBinder.BindPossibleEmbeddedStatement(node.Statement, diagnostics);

            Debug.Assert(this.Locals == this.GetDeclaredLocalsForScope(node));
            return new BoundForStatement(node,
                                         this.Locals,
                                         initializer,
                                         condition,
                                         increment,
                                         body,
                                         this.BreakLabel,
                                         this.ContinueLabel);
        }

 private LocalBinderFactory(MethodSymbol method, Binder enclosing)
 {
     Debug.Assert((object)method != null);
     _map = new SmallDictionary<CSharpSyntaxNode, Binder>(ReferenceEqualityComparer.Instance);
     _method = method;
     _enclosing = enclosing;
 }

        internal override BoundDoStatement BindDoParts(DiagnosticBag diagnostics, Binder originalBinder)
        {
            var node = (DoStatementSyntax)syntax;

            var condition = BindBooleanExpression(node.Condition, diagnostics);
            var body = originalBinder.BindPossibleEmbeddedStatement(node.Statement, diagnostics);
            return new BoundDoStatement(node, this.Locals, condition, body, this.BreakLabel, this.ContinueLabel);
        }

        /// <summary>
        /// Creates a binder with given import computation function.
        /// </summary>
        internal InContainerBinder(Binder next, Func<ConsList<Symbol>, Imports> computeImports)
            : base(next)
        {
            Debug.Assert(computeImports != null);

            _container = null;
            _computeImports = computeImports;
        }

 internal override BoundNode Bind(Binder binder, CSharpSyntaxNode node, DiagnosticBag diagnostics)
 {
     if (node.Kind() == SyntaxKind.ArrowExpressionClause)
     {
         return binder.BindExpressionBodyAsBlock((ArrowExpressionClauseSyntax)node, diagnostics);
     }
     return base.Bind(binder, node, diagnostics);
 }