private BoundPattern BindDeclarationPattern(
DeclarationPatternSyntax node,
TypeSymbol operandType,
bool hasErrors,
DiagnosticBag diagnostics)
{
Debug.Assert(operandType != (object)null);
var typeSyntax = node.Type;
bool isVar;
AliasSymbol aliasOpt;
TypeSymbol declType = BindTypeOrVarKeyword(typeSyntax, diagnostics, out isVar, out aliasOpt);
if (isVar)
{
declType = operandType;
}
if (declType == (object)null)
{
Debug.Assert(hasErrors);
declType = this.CreateErrorType("var");
}
var boundDeclType = new BoundTypeExpression(typeSyntax, aliasOpt, inferredType: isVar, type: declType);
if (IsOperatorErrors(node, operandType, boundDeclType, diagnostics))
{
hasErrors = true;
}
else
{
hasErrors |= CheckValidPatternType(typeSyntax, operandType, declType,
isVar: isVar, patternTypeWasInSource: true, diagnostics: diagnostics);
}
switch (node.Designation.Kind())
{
case SyntaxKind.SingleVariableDesignation:
break;
case SyntaxKind.DiscardDesignation:
return(new BoundDeclarationPattern(node, null, boundDeclType, isVar, hasErrors));
default:
throw ExceptionUtilities.UnexpectedValue(node.Designation.Kind());
}
var designation = (SingleVariableDesignationSyntax)node.Designation;
var identifier = designation.Identifier;
SourceLocalSymbol localSymbol = this.LookupLocal(identifier);
if (localSymbol != (object)null)
{
if ((InConstructorInitializer || InFieldInitializer) && ContainingMemberOrLambda.ContainingSymbol.Kind == SymbolKind.NamedType)
{
CheckFeatureAvailability(node, MessageID.IDS_FeatureExpressionVariablesInQueriesAndInitializers, diagnostics);
}
localSymbol.SetType(declType);
// Check for variable declaration errors.
hasErrors |= localSymbol.ScopeBinder.ValidateDeclarationNameConflictsInScope(localSymbol, diagnostics);
if (!hasErrors)
{
hasErrors = CheckRestrictedTypeInAsync(this.ContainingMemberOrLambda, declType, diagnostics, typeSyntax);
}
return(new BoundDeclarationPattern(node, localSymbol, boundDeclType, isVar, hasErrors));
}
else
{
// We should have the right binder in the chain for a script or interactive, so we use the field for the pattern.
Debug.Assert(node.SyntaxTree.Options.Kind != SourceCodeKind.Regular);
GlobalExpressionVariable expressionVariableField = LookupDeclaredField(designation);
DiagnosticBag tempDiagnostics = DiagnosticBag.GetInstance();
expressionVariableField.SetType(declType, tempDiagnostics);
tempDiagnostics.Free();
BoundExpression receiver = SynthesizeReceiver(node, expressionVariableField, diagnostics);
var variableAccess = new BoundFieldAccess(node, receiver, expressionVariableField, null, hasErrors);
return(new BoundDeclarationPattern(node, expressionVariableField, variableAccess, boundDeclType, isVar, hasErrors));
}
}
private BoundPattern BindDeclarationPattern(
DeclarationPatternSyntax node,
BoundExpression operand,
TypeSymbol operandType,
bool hasErrors,
DiagnosticBag diagnostics)
{
Debug.Assert(operand != null && operandType != (object)null);
var typeSyntax = node.Type;
var identifier = node.Identifier;
bool isVar;
AliasSymbol aliasOpt;
TypeSymbol declType = BindType(typeSyntax, diagnostics, out isVar, out aliasOpt);
if (isVar)
{
declType = operandType;
}
if (declType == (object)null)
{
Debug.Assert(hasErrors);
declType = this.CreateErrorType("var");
}
var boundDeclType = new BoundTypeExpression(typeSyntax, aliasOpt, inferredType: isVar, type: declType);
if (IsOperatorErrors(node, operandType, boundDeclType, diagnostics))
{
hasErrors = true;
}
else
{
hasErrors |= CheckValidPatternType(typeSyntax, operand, operandType, declType,
isVar: isVar, patternTypeWasInSource: true, diagnostics: diagnostics);
}
SourceLocalSymbol localSymbol = this.LookupLocal(identifier);
if (localSymbol != (object)null)
{
if (InConstructorInitializer || InFieldInitializer)
{
Error(diagnostics, ErrorCode.ERR_ExpressionVariableInConstructorOrFieldInitializer, node);
}
localSymbol.SetType(declType);
// Check for variable declaration errors.
hasErrors |= localSymbol.ScopeBinder.ValidateDeclarationNameConflictsInScope(localSymbol, diagnostics);
if (!hasErrors)
{
hasErrors = CheckRestrictedTypeInAsync(this.ContainingMemberOrLambda, declType, diagnostics, typeSyntax);
}
return(new BoundDeclarationPattern(node, localSymbol, boundDeclType, isVar, hasErrors));
}
else
{
// We should have the right binder in the chain for a script or interactive, so we use the field for the pattern.
Debug.Assert(node.SyntaxTree.Options.Kind != SourceCodeKind.Regular);
GlobalExpressionVariable expressionVariableField = LookupDeclaredField(node);
DiagnosticBag tempDiagnostics = DiagnosticBag.GetInstance();
expressionVariableField.SetType(declType, tempDiagnostics);
tempDiagnostics.Free();
BoundExpression receiver = SynthesizeReceiver(node, expressionVariableField, diagnostics);
var variableAccess = new BoundFieldAccess(node, receiver, expressionVariableField, null, hasErrors);
return(new BoundDeclarationPattern(node, expressionVariableField, variableAccess, boundDeclType, isVar, hasErrors));
}
}