Re: [Qemu-devel] [PATCH] virtio-net: Fix VirtIONet typedef redefinition

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Jan 21, 2019 at 07:10:30PM +0100, Philippe Mathieu-Daudé wrote:
> Commit 2974e916df8 introduced the VirtioNetRscChain structure which
> refer to a VirtIONet, declared later, thus required VirtIONet typedef
> to be declarated forward.
> However, when compiling with Clang in -std=gnu99 mode, this triggers
> the following warning/error:
> 
>     CC      hw/net/virtio-net.o
>   In file included from qemu/hw/net/virtio-net.c:22:
>   include/hw/virtio/virtio-net.h:189:3: error: redefinition of typedef 'VirtIONet' is a C11 feature [-Werror,-Wtypedef-redefinition]
>   } VirtIONet;
>     ^
>   include/hw/virtio/virtio-net.h:110:26: note: previous definition is here
>   typedef struct VirtIONet VirtIONet;
>                            ^
>   1 error generated.
>   make: *** [rules.mak:69: hw/net/virtio-net.o] Error 1
> 
> Fix it by removing the duplicate typedef definition.
> 
> Reported-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  include/hw/virtio/virtio-net.h | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
> index c7ec1a755f..bd662752d2 100644
> --- a/include/hw/virtio/virtio-net.h
> +++ b/include/hw/virtio/virtio-net.h
> @@ -106,7 +106,6 @@ typedef struct VirtioNetRscSeg {
>      NetClientState *nc;
>  } VirtioNetRscSeg;
>  
> -struct VirtIONet;
>  typedef struct VirtIONet VirtIONet;
>  
>  /* Chain is divided by protocol(ipv4/v6) and NetClientInfo */
> @@ -136,7 +135,7 @@ typedef struct VirtIONetQueue {
>      struct VirtIONet *n;
>  } VirtIONetQueue;
>  
> -typedef struct VirtIONet {
> +struct VirtIONet {
>      VirtIODevice parent_obj;
>      uint8_t mac[ETH_ALEN];
>      uint16_t status;
> @@ -186,7 +185,7 @@ typedef struct VirtIONet {
>      int announce_counter;
>      bool needs_vnet_hdr_swap;
>      bool mtu_bypass_backend;
> -} VirtIONet;
> +};
>  
>  void virtio_net_set_netclient_name(VirtIONet *n, const char *name,
>                                     const char *type);
> -- 
> 2.20.1