On 17/12/2019 18.34, Philippe Mathieu-Daudé wrote:
> GCC9 is confused by this comment when building with CFLAG
> -Wimplicit-fallthrough=2:
>
> hw/net/imx_fec.c: In function ‘imx_eth_write’:
> hw/net/imx_fec.c:906:12: error: this statement may fall through
> [-Werror=implicit-fallthrough=]
> 906 | if (unlikely(single_tx_ring)) {
> | ^
> hw/net/imx_fec.c:912:5: note: here
> 912 | case ENET_TDAR: /* FALLTHROUGH */
> | ^~~~
> cc1: all warnings being treated as errors
>
> Rewrite the comments in the correct place, using 'fall through'
> which is recognized by GCC and static analyzers.
>
> Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> ---
> Cc: Peter Chubb <peter.ch...@nicta.com.au>
> Cc: Peter Maydell <peter.mayd...@linaro.org>
> Cc: Jason Wang <jasow...@redhat.com>
> Cc: qemu-...@nongnu.org
> ---
> hw/net/imx_fec.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/hw/net/imx_fec.c b/hw/net/imx_fec.c
> index bd99236864..30cc07753d 100644
> --- a/hw/net/imx_fec.c
> +++ b/hw/net/imx_fec.c
> @@ -901,15 +901,17 @@ static void imx_eth_write(void *opaque, hwaddr offset,
> uint64_t value,
> s->regs[index] = 0;
> }
> break;
> - case ENET_TDAR1: /* FALLTHROUGH */
> - case ENET_TDAR2: /* FALLTHROUGH */
> + /* fall through */
Wrong location. And I think you don't need any comment here at all, GCC
should stay silent without it?
> + case ENET_TDAR1:
> + case ENET_TDAR2:
> if (unlikely(single_tx_ring)) {
> qemu_log_mask(LOG_GUEST_ERROR,
> "[%s]%s: trying to access TDAR2 or TDAR1\n",
> TYPE_IMX_FEC, __func__);
> return;
> }
> - case ENET_TDAR: /* FALLTHROUGH */
> + /* fall through */
I'd suggest to simply remove it, too.
> + case ENET_TDAR:
> if (s->regs[ENET_ECR] & ENET_ECR_ETHEREN) {
> s->regs[index] = ENET_TDAR_TDAR;
> imx_eth_do_tx(s, index);
>
Thomas
