On 7/27/22 5:11 PM, Ammar Faizi wrote:
So -D_GNU_SOURCE is the culprit. It seems to be unavoidable as
the warn seems to be compiler specific or something. Maybe that
_GNU_SOURCE patches the definition of bind().
I did:
gcc -E -D_GNU_SOURCE test.c -o xtest.c
and examined the xtest.c output.
So basically when we use _GNU_SOURCE, sometimes the declaration of
bind() is like this:
extern int bind (int __fd, __CONST_SOCKADDR_ARG __addr, socklen_t __len)
__attribute__ ((__nothrow__ , __leaf__));
With __CONST_SOCKADDR_ARG being a union:
typedef union {
const struct sockaddr *__restrict __sockaddr__;
const struct sockaddr_at *__restrict __sockaddr_at__;
const struct sockaddr_ax25 *__restrict __sockaddr_ax25__;
const struct sockaddr_dl *__restrict __sockaddr_dl__;
const struct sockaddr_eon *__restrict __sockaddr_eon__;
const struct sockaddr_in *__restrict __sockaddr_in__;
const struct sockaddr_in6 *__restrict __sockaddr_in6__;
const struct sockaddr_inarp *__restrict __sockaddr_inarp__;
const struct sockaddr_ipx *__restrict __sockaddr_ipx__;
const struct sockaddr_iso *__restrict __sockaddr_iso__;
const struct sockaddr_ns *__restrict __sockaddr_ns__;
const struct sockaddr_un *__restrict __sockaddr_un__;
const struct sockaddr_x25 *__restrict __sockaddr_x25__;
} __CONST_SOCKADDR_ARG __attribute__ ((__transparent_union__));
But not all header file included by the compiler has this union stuff.
When it doesn't, it will throw a warning like that.
--
Ammar Faizi
