Re: [dpdk-dev] ABI and inline functions

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 17 Apr 2019 09:36:38 +0100
Bruce Richardson <bruce.richardson@intel.com> wrote:

> > 
> > Coming to 1), I think DPDK cannot provide ABI compatibility unless all the inline functions are converted to normal functions and symbol versioning is done for those (not bothering about performance).
> >   
> I disagree. I think even in the case of #1, we should be able to manage
> some changes without breaking ABI.
> 
> > In this context, does it make sense to say that we will maintain API
> > compatibility rather than saying ABI compatibility? This will also send
> > the right message to the end users.
> >   
> I would value ABI compatibility much higher than API compatibility. If
> someone is recompiling the application anyway, making a couple of small
> changes (large rework is obviously a different issue) to the code should
> not be a massive issue, I hope. On the other hand, ABI compatibility is
> needed to allow seamless update from one version to another, and it's that
> ABI compatiblity that allows distro's to pick up our latest and greatest
> versions.

Agree with Bruce. What is most important about API is that the function
should change signature if behavior changes. I.e catch API changes at
compile time (not runtime).