http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46488
--- Comment #24 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-11-29
13:39:02 UTC ---
(In reply to comment #18)
> Using
>
> #define APR_RING_SENTINEL(hp, elem, link) \
> (struct elem *)((char *)(hp) - APR_OFFSETOF(struct elem, link))
>
> should be safer wrt strict aliasing.
not really. But using
typedef struct elem elem_ __attribute__((may_alias));
#define APR_RING_SENTINEL(hp, elem, link) \
(struct elem_ *)((char *)(hp) - APR_OFFSETOF(struct elem, link))
would be safe wrt strict aliasing (if the pointer is only dereferenced
directly and not casted to another pointer type before, of course).
