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

[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.