RE: [PATCH 1/2] net/i40e: compilation fix for GCC-12

["Morten Brørup" <mb@smartsharesystems.com>]

> From: Amit Prakash Shukla [mailto:amitprakashs@marvell.com]
> Sent: Wednesday, 24 August 2022 16.04
> 
> GCC 12 raises the following warning:
> 
> meson --werror --buildtype=debugoptimized
> 	--cross-file config/x86/cross-mingw -Dexamples=helloworld build
> ninja -C build
> 
> In function 'i40e_hash_get_pattern_type',
>     inlined from 'i40e_hash_get_pattern_pctypes' at
> ../drivers/net/i40e/i40e_hash.c:520:8,
>     inlined from 'i40e_hash_parse_pattern_act' at
> ../drivers/net/i40e/i40e_hash.c:1147:9,
>     inlined from 'i40e_hash_parse' at
> ../drivers/net/i40e/i40e_hash.c:1181:9:
> ../drivers/net/i40e/i40e_hash.c:389:47:
> 	error: array subscript 53 is above array
> 	bounds of 'const uint64_t[53]'
> 	{aka 'const long long unsigned int[53]'} [-Werror=array-bounds]
>   389 |                 item_hdr = pattern_item_header[last_item_type];
>       |                            ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
> ../drivers/net/i40e/i40e_hash.c: In function 'i40e_hash_parse':
> ../drivers/net/i40e/i40e_hash.c:182:23: note: while referencing
> 'pattern_item_header'
>   182 | static const uint64_t pattern_item_header[] = {
>       |                       ^~~~~~~~~~~~~~~~~~~
> cc1: all warnings being treated as errors
> 
> Fixes: ef4c16fd9148 (net/i40e: refactor RSS flow)
> Cc: stable@dpdk.org
> 
> Signed-off-by: Amit Prakash Shukla <amitprakashs@marvell.com>
> ---
> v2:
> - Removed "examples/ipsec-secgw" patch from this series and posted it
> as
> seperate patch.
> 
>  drivers/net/i40e/i40e_hash.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/i40e/i40e_hash.c
> b/drivers/net/i40e/i40e_hash.c
> index 8962e9d97a..a1ff85fceb 100644
> --- a/drivers/net/i40e/i40e_hash.c
> +++ b/drivers/net/i40e/i40e_hash.c
> @@ -384,8 +384,10 @@ i40e_hash_get_pattern_type(const struct
> rte_flow_item pattern[],
>  		}
> 
>  		prev_item_type = last_item_type;
> -		assert(last_item_type < (enum rte_flow_item_type)
> -				RTE_DIM(pattern_item_header));
> +		if (last_item_type >= (enum rte_flow_item_type)
> +				RTE_DIM(pattern_item_header))

Does this compile with the correct static branch prediction? If not, please add unlikely() to error checks like this.

> +			goto not_sup;
> +
>  		item_hdr = pattern_item_header[last_item_type];
>  		assert(item_hdr);
> 
> --
> 2.25.1
>