Am 17.05.2017 um 16:26 schrieb Ben Peart:
On 5/16/2017 3:13 PM, Johannes Sixt wrote:
Am 16.05.2017 um 19:17 schrieb Ben Peart:
OK, now I'm confused as to the best path for adding a get_be64. This
one is trivial:
#define get_be64(p) ntohll(*(uint64_t *)(p))
I cringe when I see a cast like this. Unless you can guarantee that p is
char* (bare or signed or unsigned), you fall pray to strict aliasing
violations, aka undefined behavior. And I'm not even mentioning correct
alignment, yet.
Note, this macro is only used where the CPU architecture is OK with
unaligned memory access.
I'm not worried about the unaligned memory access: It either works, or
we get a SIGBUS. The undefined behavior is more worrisome because the
code may work or not, and we can never be sure which it is.
-- Hannes
