Re: [Qemu-devel] [PATCH v2] nbd: fix uninitialized variable warning

[Philippe Mathieu-Daudé]

I was writing on your v1 "it might be worth commenting this is when
building with -O3"

This might be as easy as having the subject modified (by maintainer
taking this patch?) as:

"fix uninitialized variable warning [when building with -O3]"

On 7/16/19 12:07 PM, Marc-André Lureau wrote:
> ../block/nbd.c: In function 'nbd_co_request':
> ../block/nbd.c:745:8: error: 'local_reply.type' may be used uninitialized in 
> this function [-Werror=maybe-uninitialized]
>      if (chunk->type == NBD_REPLY_TYPE_NONE) {
>         ^
> ../block/nbd.c:710:14: note: 'local_reply.type' was declared here
>      NBDReply local_reply;
>               ^~~~~~~~~~~
> ../block/nbd.c:710:14: error: 'local_reply.flags' may be used uninitialized 
> in this function [-Werror=maybe-uninitialized]
> ../block/nbd.c:738:8: error: 'local_reply.<U4be0>.magic' may be used 
> uninitialized in this function [-Werror=maybe-uninitialized]
>      if (nbd_reply_is_simple(reply) || s->quit) {
>         ^
> ../block/nbd.c:710:14: note: 'local_reply.<U4be0>.magic' was declared here
>      NBDReply local_reply;
>               ^~~~~~~~~~~
> cc1: all warnings being treated as errors
> 
> Reported-by: Thomas Huth <address@hidden>
> Signed-off-by: Marc-André Lureau <address@hidden>
> Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
> ---
>  block/nbd.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/block/nbd.c b/block/nbd.c
> index 81edabbf35..0f74c1e455 100644
> --- a/block/nbd.c
> +++ b/block/nbd.c
> @@ -707,7 +707,7 @@ static bool nbd_reply_chunk_iter_receive(BDRVNBDState *s,
>                                           void **payload)
>  {
>      int ret, request_ret;
> -    NBDReply local_reply;
> +    NBDReply local_reply = {};
>      NBDStructuredReplyChunk *chunk;
>      Error *local_err = NULL;
>      if (s->quit) {
>