[dpdk-dev] [PATCH v2] net/i40e: remove weak symbols

[Zoltan Kiss]

On 14/09/16 15:42, Ferruh Yigit wrote:
> On 7/20/2016 6:11 PM, Zoltan Kiss wrote:
>> Using weak symbols have a few issues with static linking:
>>
>> - normally the linker searches the .o files already linked, if your weak
>>    one is there, it won't check if there is a strong version
>> - unless the symbol is directly referred, but it's not the right thing to
>>    rely on
>> - or --whole-archive specified in the command line, which pulls in a lot
>>    of unwanted stuff
>> - whole-archive also makes libtool dropping the library from the command
>>    line, which is what should happen with dynamic linking, but not with
>>    static (observed on Ubuntu 14.04). This is an important bug if you
>>    build a static library depending on DPDK
>>
>> This patch merges the two version and make the behaviour rely on the
>> config.
>>
>> If we can agree in the concept, I can send a series to fix this for the
>> other weak functions.
>>
>> Signed-off-by: Zoltan Kiss <zoltan.kiss at schaman.hu>
>> ---
> + i40e maintainers
>
> I personally prefer macros against weak symbols, because dpdk can be
> compiled as static and dynamic libraries, and weak symbols are not
> working fine when compiled as static.
>
>> Notes:
>>      v2: fix commit message
>>
>>   drivers/net/i40e/i40e_rxtx.c     | 36 +++++++++++++++++++++++++++++++++++-
>>   drivers/net/i40e/i40e_rxtx_vec.c | 36 ------------------------------------
>>   2 files changed, 35 insertions(+), 37 deletions(-)
>>
>> diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
>> index d3cfb98..ad34d3a 100644
>> --- a/drivers/net/i40e/i40e_rxtx.c
>> +++ b/drivers/net/i40e/i40e_rxtx.c
>> @@ -3278,10 +3278,44 @@ i40e_set_tx_function(struct rte_eth_dev *dev)
>>   }
>>
>>   /* Stubs needed for linkage when CONFIG_RTE_I40E_INC_VECTOR is set to 'n' */
>> -int __attribute__((weak))
>> +int __attribute__((cold))
>>   i40e_rx_vec_dev_conf_condition_check(struct rte_eth_dev __rte_unused *dev)
>>   {
>> +#ifndef RTE_LIBRTE_I40E_INC_VECTOR
>>          return -1;
>> +#else
> This moves all vector implementation into non-vector file, this is bad
> for maintaining. Why not:
>
> in i40e_rxtx.c:
> #ifndef RTE_LIBRTE_I40E_INC_VECTOR
> i40e_rx_vec_dev_conf_condition_check()
> {
> 	return -1;
> }
> #endif
>
> in i40e_rxtx_vec.c:
> No change, keep i40e_rx_vec_dev_conf_condition_check() as it is.

Sounds good. But before I send a next version, I would like to hear from 
the maintainers if they are happy with the goal of this patch.

>
> Thanks,
> ferruh