RNA generation - missing the definition of a function

I reviewed the cast modifier. Can someone explain me what happens in line 2325.

I can not find a function named rna_CastModifier_object_set anywhere. In the autogenerated code from makesrna it is called

void CastModifier_object_set(PointerRNA *ptr, PointerRNA value)
    rna_CastModifier_object_set(ptr, value);

But where can i find the definition?

NVM - found the macro. Its located in the same file at line 539.