Re: [dpdk-dev] [PATCH 4/4] eal: add assert macro for debug

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2016-04-22 12:51, Yuanhan Liu:
> On Fri, Apr 22, 2016 at 03:44:00PM +0200, Thomas Monjalon wrote:
> > --- a/drivers/net/vmxnet3/vmxnet3_rxtx.c
> > +++ b/drivers/net/vmxnet3/vmxnet3_rxtx.c
> > @@ -662,8 +662,8 @@ vmxnet3_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
> >  
> >  		PMD_RX_LOG(DEBUG, "rxd idx: %d ring idx: %d.", idx, ring_idx);
> >  
> > -		VMXNET3_ASSERT(rcd->len <= rxd->len);
> > -		VMXNET3_ASSERT(rbi->m);
> > +		RTE_ASSERT(rcd->len <= rxd->len);
> > +		RTE_ASSERT(rbi->m);
> 
> Seems this piece of code introduces a build error:
> 
>     drivers/net/vmxnet3/vmxnet3_rxtx.c: In function ‘vmxnet3_recv_pkts’:
>     drivers/net/vmxnet3/vmxnet3_rxtx.c:635:18: error: variable ‘rxd’ set but not used
>       Vmxnet3_RxDesc *rxd;
>                       ^

Indeed it can be seen with gcc when debug is disabled.
It can be fixed this way:

--- a/drivers/net/vmxnet3/vmxnet3_rxtx.c
+++ b/drivers/net/vmxnet3/vmxnet3_rxtx.c
@@ -658,6 +658,7 @@ vmxnet3_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
                idx = rcd->rxdIdx;
                ring_idx = (uint8_t)((rcd->rqID == rxq->qid1) ? 0 : 1);
                rxd = (Vmxnet3_RxDesc *)rxq->cmd_ring[ring_idx].base + idx;
+               RTE_SET_USED(rxd); /* used only for assert when enabled */
                rbi = rxq->cmd_ring[ring_idx].buf_info + idx;
 
                PMD_RX_LOG(DEBUG, "rxd idx: %d ring idx: %d.", idx, ring_idx);