On Fri, Jul 21, 2023 at 08:00:15PM +0300, Andy Shevchenko wrote:
> Introduce opaque_struct_size() helper, which may be moved
> to overflow.h in the future, and use it in the IIO core.
...
> +#define opaque_struct_size(p, a, s) ({ \
> + size_t _psize = sizeof(*(p)); \
> + size_t _asize = ALIGN(_psize, (a)); \
> + size_t _ssize = s; \
> + _ssize ? size_add(_asize, _ssize) : _psize; \
> +})
> +
> +#define opaque_struct_data(p, a) \
> + ((void *)(p) + ALIGN(sizeof(*(p)), (a)))
Hmm... This can potentially evaluate p twice.
Perhaps this variant is better:
#define opaque_struct_data(p, a) ALIGN((p) + 1, (a)))
Besides, I don't think we should worry about @s evaluation in the main macro
which may be simplified to
#define opaque_struct_size(p, a, s) \
((s) ? size_add(ALIGN(sizeof(*(p)), (a)), (s)) : sizeof(*(p)))
Thoughts?
--
With Best Regards,
Andy Shevchenko
