> Seems like 
> 
> #ifdef __daddr_t
> #define 32bit version
> #else
> #define 64bit version
> #endif
> 
> should actually do what you are looking for.

No, because elsewhere (types.h?) we have:

#ifdef __daddr_t
typedef __daddr_t daddr_t
#undef __daddr_t
#else
typedef int64_t daddr_t
#endif

So you can't tell it has been overridden.

	David

-- 
David Laight: david@l8s.co.uk