protected BoundLocalDeclaration BindVariableDeclaration(
            SourceLocalSymbol localSymbol,
            LocalDeclarationKind kind,
            bool isVar,
            VariableDeclaratorSyntax declarator,
            TypeSyntax typeSyntax,
            TypeSymbol declTypeOpt,
            AliasSymbol aliasOpt,
            DiagnosticBag diagnostics,
            CSharpSyntaxNode associatedSyntaxNode = null)
        {
            Debug.Assert(declarator != null);
            Debug.Assert((object)declTypeOpt != null || isVar);
            Debug.Assert(typeSyntax != null);

            var localDiagnostics = DiagnosticBag.GetInstance();
            // if we are not given desired syntax, we use declarator
            associatedSyntaxNode = associatedSyntaxNode ?? declarator;

            bool hasErrors = false;

            BoundExpression initializerOpt;

            // Check for variable declaration errors.
            hasErrors |= this.ValidateDeclarationNameConflictsInScope(localSymbol, localDiagnostics);

            EqualsValueClauseSyntax equalsValueClauseSyntax = declarator.Initializer;
            if (isVar)
            {
                aliasOpt = null;

                var binder = new ImplicitlyTypedLocalBinder(this, localSymbol);
                initializerOpt = binder.BindInferredVariableInitializer(localDiagnostics, equalsValueClauseSyntax, declarator);

                // If we got a good result then swap the inferred type for the "var" 
                if ((object)initializerOpt?.Type != null)
                {
                    declTypeOpt = initializerOpt.Type;

                    if (declTypeOpt.SpecialType == SpecialType.System_Void)
                    {
                        Error(localDiagnostics, ErrorCode.ERR_ImplicitlyTypedVariableAssignedBadValue, declarator, declTypeOpt);
                        declTypeOpt = CreateErrorType("var");
                        hasErrors = true;
                    }

                    if (!declTypeOpt.IsErrorType())
                    {
                        if (declTypeOpt.IsStatic)
                        {
                            Error(localDiagnostics, ErrorCode.ERR_VarDeclIsStaticClass, typeSyntax, initializerOpt.Type);
                            hasErrors = true;
                        }
                    }
                }
                else
                {
                    declTypeOpt = CreateErrorType("var");
                    hasErrors = true;
                }
            }
            else
            {
                if (ReferenceEquals(equalsValueClauseSyntax, null))
                {
                    initializerOpt = null;
                }
                else
                {
                    // Basically inlined BindVariableInitializer, but with conversion optional.
                    initializerOpt = BindPossibleArrayInitializer(equalsValueClauseSyntax.Value, declTypeOpt, localDiagnostics);
                    if (kind != LocalDeclarationKind.FixedVariable)
                    {
                        // If this is for a fixed statement, we'll do our own conversion since there are some special cases.
                        initializerOpt = GenerateConversionForAssignment(declTypeOpt, initializerOpt, localDiagnostics);
                    }
                }
            }

            Debug.Assert((object)declTypeOpt != null);

            if (kind == LocalDeclarationKind.FixedVariable)
            {
                // NOTE: this is an error, but it won't prevent further binding.
                if (isVar)
                {
                    if (!hasErrors)
                    {
                        Error(localDiagnostics, ErrorCode.ERR_ImplicitlyTypedLocalCannotBeFixed, declarator);
                        hasErrors = true;
                    }
                }

                if (!declTypeOpt.IsPointerType())
                {
                    if (!hasErrors)
                    {
                        Error(localDiagnostics, ErrorCode.ERR_BadFixedInitType, declarator);
                        hasErrors = true;
                    }
                }
                else if (!IsValidFixedVariableInitializer(declTypeOpt, localSymbol, ref initializerOpt, localDiagnostics))
                {
                    hasErrors = true;
                }
            }

            if (this.ContainingMemberOrLambda.Kind == SymbolKind.Method
                && ((MethodSymbol)this.ContainingMemberOrLambda).IsAsync
                && declTypeOpt.IsRestrictedType())
            {
                Error(localDiagnostics, ErrorCode.ERR_BadSpecialByRefLocal, typeSyntax, declTypeOpt);
                hasErrors = true;
            }

            DeclareLocalVariable(
                localSymbol,
                declarator.Identifier,
                declTypeOpt);

            Debug.Assert((object)localSymbol != null);

            ImmutableArray<BoundExpression> arguments = BindDeclaratorArguments(declarator, localDiagnostics);

            if (kind == LocalDeclarationKind.FixedVariable || kind == LocalDeclarationKind.UsingVariable)
            {
                // CONSIDER: The error message is "you must provide an initializer in a fixed 
                // CONSIDER: or using declaration". The error message could be targetted to 
                // CONSIDER: the actual situation. "you must provide an initializer in a 
                // CONSIDER: 'fixed' declaration."

                if (initializerOpt == null)
                {
                    Error(localDiagnostics, ErrorCode.ERR_FixedMustInit, declarator);
                    hasErrors = true;
                }
            }
            else if (kind == LocalDeclarationKind.Constant && initializerOpt != null && !localDiagnostics.HasAnyResolvedErrors())
            {
                var constantValueDiagnostics = localSymbol.GetConstantValueDiagnostics(initializerOpt);
                foreach (var diagnostic in constantValueDiagnostics)
                {
                    diagnostics.Add(diagnostic);
                    hasErrors = true;
                }
            }

            diagnostics.AddRangeAndFree(localDiagnostics);
            var boundDeclType = new BoundTypeExpression(typeSyntax, aliasOpt, inferredType: isVar, type: declTypeOpt);
            return new BoundLocalDeclaration(associatedSyntaxNode, localSymbol, boundDeclType, initializerOpt, arguments, hasErrors);
        }
Exemple #2
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        protected BoundLocalDeclaration BindVariableDeclaration(
            LocalDeclarationKind kind,
            bool isVar,
            VariableDeclaratorSyntax declarator,
            TypeSyntax typeSyntax,
            TypeSymbol declTypeOpt,
            AliasSymbol aliasOpt,
            DiagnosticBag diagnostics,
            CSharpSyntaxNode associatedSyntaxNode = null)
        {
            Debug.Assert(declarator != null);
            Debug.Assert((object)declTypeOpt != null || isVar);
            Debug.Assert(typeSyntax != null);

            // if we are not given desired syntax, we use declarator
            associatedSyntaxNode = associatedSyntaxNode ?? declarator;

            bool hasErrors = false;

            BoundExpression initializerOpt;

            SourceLocalSymbol localSymbol = this.LookupLocal(declarator.Identifier);

            // In error scenarios with misplaced code, it is possible we can't bind the local declaration.
            // This occurs through the semantic model.  In that case concoct a plausible result.
            if ((object)localSymbol == null)
            {
                localSymbol = SourceLocalSymbol.MakeLocal(
                    ContainingMemberOrLambda as MethodSymbol, this, typeSyntax,
                    declarator.Identifier, declarator.Initializer, LocalDeclarationKind.Variable);
            }

            // Check for variable declaration errors.
            hasErrors |= this.EnsureDeclarationInvariantMeaningInScope(localSymbol, diagnostics);

            EqualsValueClauseSyntax equalsValueClauseSyntax = declarator.Initializer;
            if (isVar)
            {
                aliasOpt = null;

                var binder = new ImplicitlyTypedLocalBinder(this, localSymbol);
                initializerOpt = binder.BindInferredVariableInitializer(diagnostics, equalsValueClauseSyntax, declarator);

                // If we got a good result then swap the inferred type for the "var" 
                if (initializerOpt != null && (object)initializerOpt.Type != null)
                {
                    declTypeOpt = initializerOpt.Type;

                    if (declTypeOpt.SpecialType == SpecialType.System_Void)
                    {
                        Error(diagnostics, ErrorCode.ERR_ImplicitlyTypedVariableAssignedBadValue, declarator, declTypeOpt);
                        declTypeOpt = CreateErrorType("var");
                        hasErrors = true;
                    }

                    if (!declTypeOpt.IsErrorType())
                    {
                        if (declTypeOpt.IsStatic)
                        {
                            Error(diagnostics, ErrorCode.ERR_VarDeclIsStaticClass, typeSyntax, initializerOpt.Type);
                            hasErrors = true;
                        }
                    }
                }
                else
                {
                    declTypeOpt = CreateErrorType("var");
                    hasErrors = true;
                }
            }
            else
            {
                if (ReferenceEquals(equalsValueClauseSyntax, null))
                {
                    initializerOpt = null;
                }
                else
                {
                    // Basically inlined BindVariableInitializer, but with conversion optional.
                    initializerOpt = BindPossibleArrayInitializer(equalsValueClauseSyntax.Value, declTypeOpt, diagnostics);
                    if (kind != LocalDeclarationKind.Fixed)
                    {
                        // If this is for a fixed statement, we'll do our own conversion since there are some special cases.
                        initializerOpt = GenerateConversionForAssignment(declTypeOpt, initializerOpt, diagnostics);
                    }
                }
            }

            Debug.Assert((object)declTypeOpt != null);

            if (kind == LocalDeclarationKind.Fixed)
            {
                // NOTE: this is an error, but it won't prevent further binding.
                if (isVar)
                {
                    if (!hasErrors)
                    {
                        Error(diagnostics, ErrorCode.ERR_ImplicitlyTypedLocalCannotBeFixed, declarator);
                        hasErrors = true;
                    }
                }

                if (!declTypeOpt.IsPointerType())
                {
                    if (!hasErrors)
                    {
                        Error(diagnostics, ErrorCode.ERR_BadFixedInitType, declarator);
                        hasErrors = true;
                    }
                }
                else if (!IsValidFixedVariableInitializer(declTypeOpt, localSymbol, ref initializerOpt, diagnostics))
                {
                    hasErrors = true;
                }
            }

            if (this.ContainingMemberOrLambda.Kind == SymbolKind.Method
                && ((MethodSymbol)this.ContainingMemberOrLambda).IsAsync
                && declTypeOpt.IsRestrictedType())
            {
                Error(diagnostics, ErrorCode.ERR_BadSpecialByRefLocal, typeSyntax, declTypeOpt);
                hasErrors = true;
            }

            DeclareLocalVariable(
                localSymbol,
                declarator.Identifier,
                declTypeOpt);

            Debug.Assert((object)localSymbol != null);

            // It is possible that we have a bracketed argument list, like "int x[];" or "int x[123];" 
            // in a non-fixed-size-array declaration . This is a common error made by C++ programmers. 
            // We have already given a good error at parse time telling the user to either make it "fixed"
            // or to move the brackets to the type. However, we should still do semantic analysis of
            // the arguments, so that errors in them are discovered, hovering over them in the IDE
            // gives good results, and so on.

            var arguments = default(ImmutableArray<BoundExpression>);

            if (declarator.ArgumentList != null)
            {
                var builder = ArrayBuilder<BoundExpression>.GetInstance();
                foreach (var argument in declarator.ArgumentList.Arguments)
                {
                    var boundArgument = BindValue(argument.Expression, diagnostics, BindValueKind.RValue);
                    builder.Add(boundArgument);
                }
                arguments = builder.ToImmutableAndFree();
            }

            if (kind == LocalDeclarationKind.Fixed || kind == LocalDeclarationKind.Using)
            {
                // CONSIDER: The error message is "you must provide an initializer in a fixed 
                // CONSIDER: or using declaration". The error message could be targetted to 
                // CONSIDER: the actual situation. "you must provide an initializer in a 
                // CONSIDER: 'fixed' declaration."

                if (initializerOpt == null)
                {
                    Error(diagnostics, ErrorCode.ERR_FixedMustInit, declarator);
                    hasErrors = true;
                }
            }
            else if (kind == LocalDeclarationKind.Constant && initializerOpt != null)
            {
                foreach (var diagnostic in localSymbol.GetConstantValueDiagnostics(initializerOpt))
                {
                    diagnostics.Add(diagnostic);
                    hasErrors = true;
                }
            }

            var boundDeclType = new BoundTypeExpression(typeSyntax, aliasOpt, inferredType: isVar, type: declTypeOpt);
            return new BoundLocalDeclaration(associatedSyntaxNode, localSymbol, boundDeclType, initializerOpt, arguments, hasErrors);
        }