[PATCH v5 07/10] net/mlx5: replace zero length array with flex array

[Thomas Monjalon]

23/01/2024 10:44, Thomas Monjalon:
> 29/11/2023 03:39, Stephen Hemminger:
> > --- a/drivers/net/mlx5/mlx5_tx.h
> > +++ b/drivers/net/mlx5/mlx5_tx.h
> > @@ -171,11 +171,12 @@ struct mlx5_txq_data {
> >  	struct mlx5_txq_stats stats; /* TX queue counters. */
> >  	struct mlx5_txq_stats stats_reset; /* stats on last reset. */
> >  	struct mlx5_uar_data uar_data;
> > -	struct rte_mbuf *elts[0];
> > +	struct rte_mbuf *elts[];
> >  	/* Storage for queued packets, must be the last field. */
> >  } __rte_cache_aligned;
> >  
> >  /* TX queue control descriptor. */
> > +__extension__
> >  struct mlx5_txq_ctrl {
> 
> struct mlx5_txq_data is included at the end of struct mlx5_txq_ctrl
> I don't understand why we need to declare an extension here.

If I remove __extension__:
error: invalid use of structure with flexible array member [-Werror=pedantic]

Is it a problem only in pedantic mode?