On Wed, 2017-11-08 at 21:17 +0100, Arjen de Korte wrote:
> Citeren Rosen Penev <ros...@gmail.com>:
>
> > Less verbose.
>
> And uses a GCC extension which makes it less portable. ISO C
> forbids
> empty initializer braces [1]. See for yourself by adding the
> -pedantic
> flag to your CFLAGS. The correct way to initialize to all-zeros is
> therefore { 0 }.
>
> [1] ISO/IEC 9899:201x, paragraph 6.7.9 Initialization, clause 21
>
> "If there are fewer initializers in a brace-enclosed list than
> there
> are elements or members
> of an aggregate, or fewer characters in a string literal used to
> initialize an array of known
> size than there are elements in the array, the remainder of
>
> the aggregate shall be
> initialized implicitly the same as objects that have static storage
> duration."
I decided to test this with the following program.
#include <stdio.h>
#include <stdint.h>
#include <string.h>
int main()
{
struct k {
int h;
int t;
};
struct k z = {5};
printf("%d", z.t);
return 0;
}
0 was printed instead of 5.
>
> > Signed-off-by: Rosen Penev <ros...@gmail.com>
> >
> > v2: some of those memset calls are needed. Also replace { 0 } with
> > {}.
> > ---
> > interface.c | 16 ++++++----------
> > 1 file changed, 6 insertions(+), 10 deletions(-)
> >
> > diff --git a/interface.c b/interface.c
> > index 7f814d2..deabcbb 100644
> > --- a/interface.c
> > +++ b/interface.c
> > @@ -186,7 +186,7 @@ read_socket4(struct uloop_fd *u, unsigned int
> > events)
> > struct iovec iov[1];
> > char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo)) +
> > CMSG_SPACE(sizeof(int)) + 1];
> > struct cmsghdr *cmsgptr;
> > - struct msghdr msg;
> > + struct msghdr msg = {};
> > socklen_t len;
> > struct sockaddr_in from;
> > int flags = 0, ifindex = -1;
> > @@ -202,7 +202,6 @@ read_socket4(struct uloop_fd *u, unsigned int
> > events)
> > iov[0].iov_base = buffer;
> > iov[0].iov_len = sizeof(buffer);
> >
> > - memset(&msg, 0, sizeof(msg));
> > msg.msg_name = (struct sockaddr *) &from;
> > msg.msg_namelen = sizeof(struct sockaddr_in);
> > msg.msg_iov = iov;
> > @@ -260,7 +259,7 @@ read_socket6(struct uloop_fd *u, unsigned int
> > events)
> > struct iovec iov[1];
> > char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo)) +
> > CMSG_SPACE(sizeof(int)) + 1];
> > struct cmsghdr *cmsgptr;
> > - struct msghdr msg;
> > + struct msghdr msg = {};
> > socklen_t len;
> > struct sockaddr_in6 from;
> > int flags = 0, ifindex = -1;
> > @@ -276,7 +275,6 @@ read_socket6(struct uloop_fd *u, unsigned int
> > events)
> > iov[0].iov_base = buffer;
> > iov[0].iov_len = sizeof(buffer);
> >
> > - memset(&msg, 0, sizeof(msg));
> > msg.msg_name = (struct sockaddr *) &from;
> > msg.msg_namelen = sizeof(struct sockaddr_in6);
> > msg.msg_iov = iov;
> > @@ -327,17 +325,16 @@ read_socket6(struct uloop_fd *u, unsigned int
> > events)
> > static int
> > interface_mcast_setup4(struct interface *iface)
> > {
> > - struct ip_mreqn mreq;
> > + struct ip_mreqn mreq = {};
> > uint8_t ttl = 255;
> > int no = 0;
> > - struct sockaddr_in sa = { 0 };
> > + struct sockaddr_in sa = {};
> > int fd = iface->fd.fd;
> >
> > sa.sin_family = AF_INET;
> > sa.sin_port = htons(MCAST_PORT);
> > inet_pton(AF_INET, MCAST_ADDR, &sa.sin_addr);
> >
> > - memset(&mreq, 0, sizeof(mreq));
> > mreq.imr_address.s_addr = iface->v4_addr.s_addr;
> > mreq.imr_multiaddr = sa.sin_addr;
> > mreq.imr_ifindex = iface->ifindex;
> > @@ -368,17 +365,16 @@ interface_mcast_setup4(struct interface
> > *iface)
> > static int
> > interface_socket_setup6(struct interface *iface)
> > {
> > - struct ipv6_mreq mreq;
> > + struct ipv6_mreq mreq = {};
> > int ttl = 255;
> > int no = 0;
> > - struct sockaddr_in6 sa = { 0 };
> > + struct sockaddr_in6 sa = {};
> > int fd = iface->fd.fd;
> >
> > sa.sin6_family = AF_INET6;
> > sa.sin6_port = htons(MCAST_PORT);
> > inet_pton(AF_INET6, MCAST_ADDR6, &sa.sin6_addr);
> >
> > - memset(&mreq, 0, sizeof(mreq));
> > mreq.ipv6mr_multiaddr = sa.sin6_addr;
> > mreq.ipv6mr_interface = iface->ifindex;
>
>
>
>
> _______________________________________________
> Lede-dev mailing list
> Lede-dev@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/lede-dev
_______________________________________________
Lede-dev mailing list
Lede-dev@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/lede-dev
