Hi Bastien, On 1/20/23 21:32, Bastien Roucariès wrote: [...]
diff --git a/bits/socket.h b/bits/socket.h index aac8c49b00..c0c23b4e84 100644 --- a/bits/socket.h +++ b/bits/socket.h @@ -168,9 +168,14 @@ struct sockaddrstruct sockaddr_storage{ - __SOCKADDR_COMMON (ss_); /* Address family, etc. */ - char __ss_padding[_SS_PADSIZE]; - __ss_aligntype __ss_align; /* Force desired alignment. */no this is not correct you break ABI by reducing size+ union + { + __SOCKADDR_COMMON (ss_); /* Address family, etc. */ + struct sockaddr sa; + struct sockaddr_in sin; + struct sockaddr_in6 sin6; + struct sockaddr_un sun; + }; };Correct one structure is struct __private_sock_storage { __SOCKADDR_COMMON (ssprivate_); /* Address family, etc. */ char __ss_padding[_SS_PADSIZE]; __ss_aligntype __ss_align; /* Force desired alignment. */ }
What is this structure for? I expect that it's for declaring a wide-enough and correctly aligned type, but the union containing all the other types already guarantees a size as wide as any other sockaddr_* and with the widest alignment.
Also, any member that is necessary for superalignment or padding could be added at the end of sockaddr_storage, after the anon union; you don't need the extra struct, I guess.
Right?
struct sockaddr_storage
{
union
{
__SOCKADDR_COMMON (ss_); /* Address family, etc. */
struct sockaddr sa;
struct sockaddr_in sin;
struct sockaddr_in6 sin6;
struct sockaddr_un sun;
struct __private_sock_storage _private;
};
};
May it could be dropped later using align construct for modern C and padding
Cheers, Alex
Bastien
-- <http://www.alejandro-colomar.es/>
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