protected override void MethodChecks(DiagnosticBag diagnostics)
{
var binder = this.DeclaringCompilation.
GetBinderFactory(syntaxReferenceOpt.SyntaxTree).GetBinder(ReturnTypeSyntax, GetSyntax(), this);
SyntaxToken arglistToken;
var signatureBinder = binder.WithAdditionalFlags(BinderFlags.SuppressConstraintChecks);
_lazyParameters = ParameterHelpers.MakeParameters(
signatureBinder,
this,
ParameterListSyntax,
out arglistToken,
allowRefOrOut: true,
allowThis: false,
addRefReadOnlyModifier: false,
diagnostics: diagnostics);
if (arglistToken.Kind() == SyntaxKind.ArgListKeyword)
{
// This is a parse-time error in the native compiler; it is a semantic analysis error in Roslyn.
// error CS1669: __arglist is not valid in this context
diagnostics.Add(ErrorCode.ERR_IllegalVarArgs, new SourceLocation(arglistToken));
// Regardless of whether __arglist appears in the source code, we do not mark
// the operator method as being a varargs method.
}
_lazyReturnType = signatureBinder.BindType(ReturnTypeSyntax, diagnostics);
// restricted types cannot be returned.
// NOTE: Span-like types can be returned (if expression is returnable).
if (_lazyReturnType.IsRestrictedType(ignoreSpanLikeTypes: true))
{
// Method or delegate cannot return type '{0}'
diagnostics.Add(ErrorCode.ERR_MethodReturnCantBeRefAny, ReturnTypeSyntax.Location, _lazyReturnType.Type);
}
if (_lazyReturnType.Type.IsStatic)
{
// '{0}': static types cannot be used as return types
diagnostics.Add(ErrorCode.ERR_ReturnTypeIsStaticClass, ReturnTypeSyntax.Location, _lazyReturnType.Type);
}
this.SetReturnsVoid(_lazyReturnType.IsVoidType());
// If we have a conversion/equality/inequality operator in an interface or static class then we already
// have reported that fact as an error. No need to cascade the error further.
if ((this.ContainingType.IsInterfaceType() &&
(MethodKind == MethodKind.Conversion || Name == WellKnownMemberNames.EqualityOperatorName || Name == WellKnownMemberNames.InequalityOperatorName)) ||
this.ContainingType.IsStatic)
{
return;
}
// SPEC: All types referenced in an operator declaration must be at least as accessible
// SPEC: as the operator itself.
CheckEffectiveAccessibility(_lazyReturnType, _lazyParameters, diagnostics);
CheckValueParameters(diagnostics);
CheckOperatorSignatures(diagnostics);
}