Re: [dpdk-dev] [PATCH] net/mlx5: fix debug variable initialization

[Gregory Etelson <getelson@nvidia.com>]

Hello Ferruh,

I posted updated patch in https://patchwork.dpdk.org/project/dpdk/patch/20211104132853.31403-1-getelson@nvidia.com/

Regards,
Gregory

> 
> On 11/4/2021 12:23 PM, Gregory Etelson wrote:
> > Use `__rte_unused` macro to mask a debug
> variable instead of `#ifdef`.
> > This way, if the variable is used in a macro, it
> does not depend on
> > how the macro is expanded.
> >
> > Fixes: 91f0e029ce5f ("net/mlx5: translate flex
> item pattern into matcher")
> > Signed-off-by: Gregory Etelson
> <getelson@nvidia.com>
> > ---
> >   drivers/net/mlx5/mlx5_flow_flex.c | 4 +---
> >   1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/drivers/net/mlx5/mlx5_flow_flex.c
> b/drivers/net/mlx5/mlx5_flow_flex.c
> > index bdfa383c45..be0f9821ce 100644
> > --- a/drivers/net/mlx5/mlx5_flow_flex.c
> > +++ b/drivers/net/mlx5/mlx5_flow_flex.c
> > @@ -222,9 +222,7 @@
> mlx5_flex_flow_translate_item(struct
> rte_eth_dev *dev,
> >                             const struct rte_flow_item
> *item,
> >                             bool is_inner)
> >   {
> > -#ifdef RTE_LIBRTE_MLX5_DEBUG
> > -     struct mlx5_priv *priv = dev->data-
> >dev_private;
> > -#endif
> > +     __rte_unused struct mlx5_priv *priv =
> dev->data->dev_private;
> 
> Marking the variable as unused to silence
> compiler for some cases,
> but it is indeed used, what about something like
> this (inspired by
> sfc code):
> 
>   #if defined(RTE_LIBRTE_MLX5_DEBUG) ||
> defined(RTE_ENABLE_ASSERT)
>     struct mlx5_priv *priv = dev->data-
> >dev_private;
>   #endif
> 
> >       const struct rte_flow_item_flex *spec,
> *mask;
> >       void *misc4_m =
> MLX5_ADDR_OF(fte_match_param, matcher,
> >                                    misc_parameters_4);
> >