On Fri, Mar 30, 2018 at 10:47:09PM +0800, Tonghao Zhang wrote:
> I rebuild it on ubuntu 17.10 and cash it. I use the 'RTE_SET_USED' to fix it.
>
>
> diff --git a/lib/librte_vhost/fd_man.c b/lib/librte_vhost/fd_man.c
> index 771675718..f11803191 100644
> --- a/lib/librte_vhost/fd_man.c
> +++ b/lib/librte_vhost/fd_man.c
> @@ -279,7 +279,8 @@ fdset_pipe_read_cb(int readfd, void *dat __rte_unused,
> int *remove __rte_unused)
> {
> char charbuf[16];
> - read(readfd, charbuf, sizeof(charbuf));
> + int r = read(readfd, charbuf, sizeof(charbuf));
> + RTE_SET_USED(r);
> }
>
> void
> @@ -319,5 +320,6 @@ fdset_pipe_init(struct fdset *fdset)
> void
> fdset_pipe_notify(struct fdset *fdset)
> {
> - write(fdset->u.writefd, "1", 1);
> + int r = write(fdset->u.writefd, "1", 1);
> + RTE_SET_USED(r);
> }
>
A better option might be to use _Pragma
Something like this perhaps
#define ALLOW_UNUSED(x) \
_Pragma(push) \
_Pragma(diagnostic ignored "-Wunused-result") \
#x;\
_Pragma(pop)
This is of course untested, so it probably needs some tweaking, but this method
avoids the need to declare an additional stack variable, which i don't think can
be eliminated due to the cast. I believe that this method should also work
accross compilers (the gcc and clang compilers support this, and i think the
intel compiler should as well)
Neil
