[dpdk-dev] ABI versioning in Windows

[Neil Horman]

On Wed, May 27, 2020 at 02:50:07PM +0200, Thomas Monjalon wrote:
> +Cc more people
> 
> 27/05/2020 12:41, Fady Bader:
> > What should we do with the ABI versioning in Windows ?
> 
> I think there are 2 questions here:
> 
> 1/ Do we want to maintain ABI compatibility on Windows like we do for Linux and FreeBSD?
> The decision must be clearly documented.
> 
My first notion, without any greater thought is "why wouldn't we".  ABI
stability is OS agnostic.  If a symbol is considered stable, theres no reason
that I can think of that it wouldn't be stable for each OS.

> 2/ How do we implement the macros in rte_function_versioning.h for Windows?
> Something needs to be done, otherwise we cannot compile libraries having some function versioning.
> 
Can you elaborate on what exactly the issue is here?  I presume by your comment
above that visual studio either doesn't support symbol level versioning or
doesn't support versioning at all?

If thats the case, and there is a commitment to make dpdk buildable on windows,
I suppose the only choice is to make a ifdef WINDOWS section of the
rte_function_versioning.h file, and effectively turn all the macros into no-ops.
The BIND_DEFAULT_SYMBOL macro looks like it could still work, as MSVC has an
alias linker command thats implementable via __pragma, but thats probably all we
can do, unless there is some more robust versioning support that I can't find.
Note we will also likely need to agument the makefiles/meson files so that the
link stage doesn't pass the version script to the linker 

Neil

> 
>