CC does only use the first pre-processor in #ifdef statements. If you search through the forums you'll realise that handling of pre-processors is not an easy task and done in a simple way in CC.
Because in the system header file, the conditions contained in the situation too much.
Although there are technical difficulty, but if not properly judge, CC is difficult to achieve the desired results.
In my humble and willing to please CC the team on this issue to find ways to find an ideal solution.
Thanks!