[PATCH] eal: fix cache guard for pedantic compilation

[Morten Brørup]

Forgot cc stable.

> From: Morten Brørup [mailto:mb at smartsharesystems.com]
> Sent: Monday, 23 March 2026 09.12
> 
> The cache guard macro uses __COUNTER__ to generate unique names.
> However, although most C compilers support __COUNTER__, it is not yet
> part of the C standard, so compilation fails when building in pedantic
> mode.
> The macro was changed to use __LINE__ instead.
> 
> Fixes: 65f600c0f000 ("eal: add empty cache line macro")
> 
> Signed-off-by: Morten Brørup <mb at smartsharesystems.com>
> ---
>  lib/eal/include/rte_common.h | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/eal/include/rte_common.h
> b/lib/eal/include/rte_common.h
> index 573bf4f2ce..97865aaa39 100644
> --- a/lib/eal/include/rte_common.h
> +++ b/lib/eal/include/rte_common.h
> @@ -751,8 +751,12 @@ rte_is_aligned(const void * const __rte_restrict
> ptr, const unsigned int align)
>   *
>   * Use as spacing between data accessed by different lcores,
>   * to prevent cache thrashing on hardware with speculative
> prefetching.
> + *
> + * Note: Although __COUNTER__ would be better for uniqueness, it is
> not yet
> + * (March 2026) part of the C standard, so compilation would fail when
> building
> + * in pedantic mode.
>   */
> -#define RTE_CACHE_GUARD _RTE_CACHE_GUARD_HELPER1(__COUNTER__)
> +#define RTE_CACHE_GUARD _RTE_CACHE_GUARD_HELPER1(__LINE__)
> 
>  /*********** PA/IOVA type definitions ********/
> 
> --
> 2.43.0