internal void ComputeReturnType()
{
if (!_lazyReturnType.IsNull)
{
return;
}
var diagnostics = DiagnosticBag.GetInstance();
TypeSyntax returnTypeSyntax = _syntax.ReturnType;
TypeSymbolWithAnnotations returnType = _binder.BindType(returnTypeSyntax, diagnostics);
if (this.IsAsync)
{
if (this.RefKind != RefKind.None)
{
ReportBadRefToken(returnTypeSyntax, diagnostics);
}
else if (returnType.TypeSymbol.IsBadAsyncReturn(this.DeclaringCompilation))
{
diagnostics.Add(ErrorCode.ERR_BadAsyncReturn, this.Locations[0]);
}
}
var location = _syntax.ReturnType.Location;
if (_refKind == RefKind.RefReadOnly)
{
DeclaringCompilation.EnsureIsReadOnlyAttributeExists(diagnostics, location, modifyCompilation: false);
}
if (returnType.NeedsNullableAttribute())
{
DeclaringCompilation.EnsureNullableAttributeExists(diagnostics, location, modifyCompilation: false);
// Note: we don't need to warn on annotations used without NonNullTypes context for local functions, as this is handled in binding already
}
// span-like types are returnable in general
if (returnType.IsRestrictedType(ignoreSpanLikeTypes: true))
{
// Method or delegate cannot return type '{0}'
diagnostics.Add(ErrorCode.ERR_MethodReturnCantBeRefAny, returnTypeSyntax.Location, returnType.TypeSymbol);
}
Debug.Assert(_refKind == RefKind.None ||
returnType.SpecialType != SpecialType.System_Void ||
returnTypeSyntax.HasErrors);
lock (_declarationDiagnostics)
{
if (!_lazyReturnType.IsNull)
{
diagnostics.Free();
return;
}
_declarationDiagnostics.AddRangeAndFree(diagnostics);
_lazyReturnType = returnType;
}
}
protected override DiagnosticInfo ResolveInfo()
{
if (_possiblyRestrictedTypeSymbol.IsRestrictedType())
{
return(new CSDiagnosticInfo(ErrorCode.ERR_ArrayElementCantBeRefAny, _possiblyRestrictedTypeSymbol.TypeSymbol));
}
return(null);
}
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.TypeSymbol);
}
if (_lazyReturnType.TypeSymbol.IsStatic)
{
// '{0}': static types cannot be used as return types
diagnostics.Add(ErrorCode.ERR_ReturnTypeIsStaticClass, ReturnTypeSyntax.Location, _lazyReturnType.TypeSymbol);
}
this.SetReturnsVoid(_lazyReturnType.SpecialType == SpecialType.System_Void);
// If we have an 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() || 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);
}
