On 06/07/2017 04:56 PM, Andrew Haley wrote:
On 07/06/17 14:45, K wrote:
And I found that that a version which I beleve mustn't have aliasing
problems still generates same warnings.
It still has aliasing problems: you can't make them magically go away
by using an intermediate uint8_t*.
You're doing this:
struct udp_pseudo {
uint32_t src;
uint32_t dst;
uint8_t z;
uint8_t proto;
uint16_t len;
} tmp;
...
auto ret = calc_16bit_checksum_part((uint8_t*)&tmp, sizeof(tmp), 0);
static uint32_t calc_16bit_checksum_part(uint8_t* buf, int len,
uint32_t ret) {
struct ui16{
uint16_t d;
};
ui16 *ptr = (ui16*)buf;
There's no need for any of this messing about with pointer casts, as has
been explained.
Sorry, but I still can't get the idea. Cast from udp_pseudo to uint8_t
doesn't have an aliasing problem (std 8.8) and a cast from uint8_t to
ui16 still doesn't have an aliasing problem (std 8.6), or may be I
missed something?
Kirill.
