protected void Error_CannotChangeAccessModifiers (MemberCore member, MemberSpec base_member)
{
var base_modifiers = base_member.Modifiers;
// Remove internal modifier from types which are not internally accessible
if ((base_modifiers & Modifiers.AccessibilityMask) == (Modifiers.PROTECTED | Modifiers.INTERNAL) &&
!base_member.DeclaringType.MemberDefinition.IsInternalAsPublic (member.Module.DeclaringAssembly))
base_modifiers = Modifiers.PROTECTED;
Report.SymbolRelatedToPreviousError (base_member);
Report.Error (507, member.Location,
"`{0}': cannot change access modifiers when overriding `{1}' inherited member `{2}'",
member.GetSignatureForError (),
ModifiersExtensions.AccessibilityName (base_modifiers),
base_member.GetSignatureForError ());
}
//
// Performs various checks on the MethodInfo `mb' regarding the modifier flags
// that have been defined.
//
protected virtual bool CheckOverrideAgainstBase (MemberSpec base_member)
{
bool ok = true;
if ((base_member.Modifiers & (Modifiers.ABSTRACT | Modifiers.VIRTUAL | Modifiers.OVERRIDE)) == 0) {
Report.SymbolRelatedToPreviousError (base_member);
Report.Error (506, Location,
"`{0}': cannot override inherited member `{1}' because it is not marked virtual, abstract or override",
GetSignatureForError (), TypeManager.CSharpSignature (base_member));
ok = false;
}
// Now we check that the overriden method is not final
if ((base_member.Modifiers & Modifiers.SEALED) != 0) {
Report.SymbolRelatedToPreviousError (base_member);
Report.Error (239, Location, "`{0}': cannot override inherited member `{1}' because it is sealed",
GetSignatureForError (), TypeManager.CSharpSignature (base_member));
ok = false;
}
var base_member_type = ((IInterfaceMemberSpec) base_member).MemberType;
if (!TypeSpecComparer.Override.IsEqual (MemberType, base_member_type)) {
Report.SymbolRelatedToPreviousError (base_member);
if (this is PropertyBasedMember) {
Report.Error (1715, Location, "`{0}': type must be `{1}' to match overridden member `{2}'",
GetSignatureForError (), base_member_type.GetSignatureForError (), base_member.GetSignatureForError ());
} else {
Report.Error (508, Location, "`{0}': return type must be `{1}' to match overridden member `{2}'",
GetSignatureForError (), base_member_type.GetSignatureForError (), base_member.GetSignatureForError ());
}
ok = false;
}
return ok;
}