Re: [PATCH] net/af_xdp: limit libbpf version to <= v0.7.0

[Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>]

On 6/24/22 13:10, Thomas Monjalon wrote:
> 24/06/2022 10:37, Loftus, Ciara:
>>>
>>> 24/06/2022 08:06, Ciara Loftus:
>>>> Linking with libbpf v0.8.0 causes deprication warnings. As a temporary
>>>> measure, prevent linking with libbpf versions v0.8.0 and greater. This
>>>> limitation should be removed in the future when appropriate
>>>> compatibility measures are introduced.
>>>>
>>>> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
>>>> ---
>>>> -bpf_dep = dependency('libbpf', required: false, method: 'pkg-config')
>>>> -if not bpf_dep.found()
>>>> -    bpf_dep = cc.find_library('bpf', required: false)
>>>> -endif
>>>> +bpf_dep = dependency('libbpf', version : '<=0.7.0', required: false,
>>> method: 'pkg-config')
>>>
>>> It is also removing the find_library() method.
>>> Any reason it was there?
>>>
>>
>> My understanding is that one can't check the library version using that method.
>> So it was a valid method of picking up the library until now where we always need to check the version before linking.
> 
> OK I see

IMHO checking library version is a bad approach. We should file
the library of whatever version and check for symbols etc in it
and provide corresponding HAVE_ defines to handle it in code.