Re: [dpdk-dev] [PATCH] net/ixgbe: fix build for gcc 4.8.5

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 1/14/20 6:52 PM, Ferruh Yigit wrote:
> Build error:
>   In function ‘ixgbe_recv_pkts_lro_bulk_alloc’:
> ../drivers/net/ixgbe/ixgbe_rxtx.c:2209:24:
>   error: ‘next_sc_entry’ may be used uninitialized in this function
>   [-Werror=maybe-uninitialized]
>     next_sc_entry->fbuf = first_seg;
>                         ^
> http://mails.dpdk.org/archives/test-report/2020-January/113891.html
> 
> This is a compiler false positive and error not seen by newer compilers,
> or clang but to fix the warning initializing the complained variable.

You might want to add the RHEL7 GCC version I reproduced it on:
$ gcc --version
gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)

> According git bisect, no idea how:
> Fixes: 8a2e7ce976fd ("net/ixgbe: avoid multiple definitions of bool")
> 
> Reported-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>

Tested-by: Maxime Coquelin <maxime.coquelin@redhat.com>

> ---
> Cc: dharmik.thakkar@arm.com
> ---
>  drivers/net/ixgbe/ixgbe_rxtx.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
> index 13b06eb9c..30f890572 100644
> --- a/drivers/net/ixgbe/ixgbe_rxtx.c
> +++ b/drivers/net/ixgbe/ixgbe_rxtx.c
> @@ -2028,7 +2028,7 @@ ixgbe_recv_pkts_lro(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts,
>  		bool eop;
>  		struct ixgbe_rx_entry *rxe;
>  		struct ixgbe_scattered_rx_entry *sc_entry;
> -		struct ixgbe_scattered_rx_entry *next_sc_entry;
> +		struct ixgbe_scattered_rx_entry *next_sc_entry = NULL;
>  		struct ixgbe_rx_entry *next_rxe = NULL;
>  		struct rte_mbuf *first_seg;
>  		struct rte_mbuf *rxm;
>