private SourceLocalSymbol(
Symbol containingSymbol,
Binder scopeBinder,
bool allowRefKind,
TypeSyntax typeSyntax,
SyntaxToken identifierToken,
LocalDeclarationKind declarationKind)
{
Debug.Assert(identifierToken.Kind() != SyntaxKind.None);
Debug.Assert(declarationKind != LocalDeclarationKind.None);
Debug.Assert(scopeBinder != null);
this._scopeBinder = scopeBinder;
this._containingSymbol = containingSymbol;
this._identifierToken = identifierToken;
this._typeSyntax = allowRefKind ? typeSyntax.SkipRef(out this._refKind) : typeSyntax;
this._declarationKind = declarationKind;
// create this eagerly as it will always be needed for the EnsureSingleDefinition
_locations = ImmutableArray.Create<Location>(identifierToken.GetLocation());
}
private TypeSymbol BindVariableType(CSharpSyntaxNode declarationNode, DiagnosticBag diagnostics, TypeSyntax typeSyntax, ref bool isConst, out bool isVar, out AliasSymbol alias)
{
Debug.Assert(
declarationNode.Kind() == SyntaxKind.SingleVariableDesignation ||
declarationNode.Kind() == SyntaxKind.VariableDeclaration ||
declarationNode.Kind() == SyntaxKind.DeclarationExpression);
// If the type is "var" then suppress errors when binding it. "var" might be a legal type
// or it might not; if it is not then we do not want to report an error. If it is, then
// we want to treat the declaration as an explicitly typed declaration.
RefKind refKind;
TypeSymbol declType = BindType(typeSyntax.SkipRef(out refKind), diagnostics, out isVar, out alias);
Debug.Assert((object)declType != null || isVar);
if (isVar)
{
// There are a number of ways in which a var decl can be illegal, but in these
// cases we should report an error and then keep right on going with the inference.
if (isConst)
{
Error(diagnostics, ErrorCode.ERR_ImplicitlyTypedVariableCannotBeConst, declarationNode);
// Keep processing it as a non-const local.
isConst = false;
}
// In the dev10 compiler the error recovery semantics for the illegal case
// "var x = 10, y = 123.4;" are somewhat undesirable.
//
// First off, this is an error because a straw poll of language designers and
// users showed that there was no consensus on whether the above should mean
// "double x = 10, y = 123.4;", taking the best type available and substituting
// that for "var", or treating it as "var x = 10; var y = 123.4;" -- since there
// was no consensus we decided to simply make it illegal.
//
// In dev10 for error recovery in the IDE we do an odd thing -- we simply take
// the type of the first variable and use it. So that is "int x = 10, y = 123.4;".
//
// This seems less than ideal. In the error recovery scenario it probably makes
// more sense to treat that as "var x = 10; var y = 123.4;" and do each inference
// separately.
if (declarationNode.Parent.Kind() == SyntaxKind.LocalDeclarationStatement &&
((VariableDeclarationSyntax)declarationNode).Variables.Count > 1 && !declarationNode.HasErrors)
{
Error(diagnostics, ErrorCode.ERR_ImplicitlyTypedVariableMultipleDeclarator, declarationNode);
}
}
else
{
// In the native compiler when given a situation like
//
// D[] x;
//
// where D is a static type we report both that D cannot be an element type
// of an array, and that D[] is not a valid type for a local variable.
// This seems silly; the first error is entirely sufficient. We no longer
// produce additional errors for local variables of arrays of static types.
if (declType.IsStatic)
{
Error(diagnostics, ErrorCode.ERR_VarDeclIsStaticClass, typeSyntax, declType);
}
if (isConst && !declType.CanBeConst())
{
Error(diagnostics, ErrorCode.ERR_BadConstType, typeSyntax, declType);
// Keep processing it as a non-const local.
isConst = false;
}
}
return declType;
}