With button selectors you can implement the @selector but might choose to implement the method in the View Controller and not the button subclass for example. You will receive an undeclared selector warning for this to let you know the method is not implemented but this is acceptable behaviour, so you can use the following to hide the warnings.
// Ignore undeclared selector warnings as this method is implemented in the VC
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wundeclared-selector"
[moreButton addTarget:nil action: @selector(userPressedShareBasementButton:) forControlEvents: UIControlEventTouchUpInside];
#pragma clang diagnostic pop