Re: [PATCH 1/2] config: add compatibility for old compilers with new UAPI headers

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 30 Sep 2026 11:57:59 +0200
Maxime Coquelin <maxime.coquelin@redhat.com> wrote:

> This patch adds a compatibility define for __counted_by attribute,
> which is not present in older compilers but required for recent UAPI
> headers like vfio.h.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  config/rte_config.h | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/config/rte_config.h b/config/rte_config.h
> index 0447cdf2ad..307e7dac62 100644
> --- a/config/rte_config.h
> +++ b/config/rte_config.h
> @@ -25,6 +25,15 @@
>  #define RTE_TOOLCHAIN_MSVC 1
>  #endif
>  
> +/*
> + * Compatibility define for Linux kernel UAPI headers that may use __counted_by
> + * attribute for bounds checking. This attribute is not understood by userspace
> + * compilers, so define it as empty if not already provided.
> + */
> +#ifndef __counted_by
> +#define __counted_by(m)
> +#endif
> +
>  /* legacy defines */
>  #ifdef RTE_EXEC_ENV_LINUX
>  #define RTE_EXEC_ENV_LINUXAPP 1

NAK this is best done by keeping up to date stddef over in virtio headers.