On Monday 21 November 2016 10:25 PM, Jan Blunck wrote:
> This macro is based on Jan Viktorin's original patch but also checks the
> type of the passed pointer against the type of the member.
>
> Signed-off-by: Jan Viktorin <viktorin at rehivetech.com>
> Signed-off-by: Shreyansh Jain <shreyansh.jain at nxp.com>
> [jblunck at infradead.org: add type checking and __extension__]
> Signed-off-by: Jan Blunck <jblunck at infradead.org>
> ---
> lib/librte_eal/common/include/rte_common.h | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/lib/librte_eal/common/include/rte_common.h
> b/lib/librte_eal/common/include/rte_common.h
> index db5ac91..8dda3e2 100644
> --- a/lib/librte_eal/common/include/rte_common.h
> +++ b/lib/librte_eal/common/include/rte_common.h
> @@ -331,6 +331,26 @@ rte_bsf32(uint32_t v)
> #define offsetof(TYPE, MEMBER) __builtin_offsetof (TYPE, MEMBER)
> #endif
>
> +/**
> + * Return pointer to the wrapping struct instance.
> + *
> + * Example:
> + *
> + * struct wrapper {
> + * ...
> + * struct child c;
> + * ...
> + * };
> + *
> + * struct child *x = obtain(...);
> + * struct wrapper *w = container_of(x, struct wrapper, c);
> + */
> +#ifndef container_of
> +#define container_of(ptr, type, member) __extension__ ({
> \
> + typeof(((type *)0)->member) *_ptr = (ptr); \
> + (type *)(((char *)_ptr) - offsetof(type, member)); })
> +#endif
> +
> #define _RTE_STR(x) #x
> /** Take a macro value and get a string version of it */
> #define RTE_STR(x) _RTE_STR(x)
>
I will start using this in my patchset.
Acked-by: Shreyansh Jain <shreyansh.jain at nxp.com>
