Declaring zero-length arrays in other contexts, including as interior members of structure objects or as non-member objects, is discouraged. Accessing elements of zero-length arrays declared in such contexts is undefined and may be diagnosed.[1]
Fix by using unnamed union and struct. https://bugs.dpdk.org/show_bug.cgi?id=396 Bugzilla ID: 396 [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html Fixes: 3e6181b07038 ("mbuf: use structure marker from EAL") Cc: sta...@dpdk.org Signed-off-by: Gavin Hu <gavin...@arm.com> --- v2: * change 'uint64_t rearm_data' to 'uint_64_t rearm_data[1]' to fix the SFC PMD compiling error on x86. <Kevin Traynor> --- lib/librte_mbuf/rte_mbuf_core.h | 54 +++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 22 deletions(-) diff --git a/lib/librte_mbuf/rte_mbuf_core.h b/lib/librte_mbuf/rte_mbuf_core.h index b9a59c879..34cb152e2 100644 --- a/lib/librte_mbuf/rte_mbuf_core.h +++ b/lib/librte_mbuf/rte_mbuf_core.h @@ -480,31 +480,41 @@ struct rte_mbuf { rte_iova_t buf_physaddr; /**< deprecated */ } __rte_aligned(sizeof(rte_iova_t)); - /* next 8 bytes are initialised on RX descriptor rearm */ - RTE_MARKER64 rearm_data; - uint16_t data_off; - - /** - * Reference counter. Its size should at least equal to the size - * of port field (16 bits), to support zero-copy broadcast. - * It should only be accessed using the following functions: - * rte_mbuf_refcnt_update(), rte_mbuf_refcnt_read(), and - * rte_mbuf_refcnt_set(). The functionality of these functions (atomic, - * or non-atomic) is controlled by the CONFIG_RTE_MBUF_REFCNT_ATOMIC - * config option. - */ RTE_STD_C11 union { - rte_atomic16_t refcnt_atomic; /**< Atomically accessed refcnt */ - /** Non-atomically accessed refcnt */ - uint16_t refcnt; - }; - uint16_t nb_segs; /**< Number of segments. */ + /* next 8 bytes are initialised on RX descriptor rearm */ + uint64_t rearm_data[1]; + RTE_STD_C11 + struct { + uint16_t data_off; + + /** + * Reference counter. Its size should at least equal to + * the size of port field (16 bits), to support + * zero-copy broadcast. It should only be accessed + * using the following functions: + * rte_mbuf_refcnt_update(), rte_mbuf_refcnt_read(), + * and rte_mbuf_refcnt_set(). The functionality of + * these functions (atomic, or non-atomic) is + * controlled by the CONFIG_RTE_MBUF_REFCNT_ATOMIC + * config option. + */ + RTE_STD_C11 + union { + /**< Atomically accessed refcnt */ + rte_atomic16_t refcnt_atomic; + /** Non-atomically accessed refcnt */ + uint16_t refcnt; + }; + uint16_t nb_segs; /**< Number of segments. */ - /** Input port (16 bits to support more than 256 virtual ports). - * The event eth Tx adapter uses this field to specify the output port. - */ - uint16_t port; + /** Input port (16 bits to support more than 256 + * virtual ports). The event eth Tx adapter uses this + * field to specify the output port. + */ + uint16_t port; + }; + }; uint64_t ol_flags; /**< Offload features. */ -- 2.25.0
