Re: RTE_MARKER with MSVC

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

On Sat, Feb 24, 2024 at 12:16:58PM +0100, Morten Brørup wrote:
> Hi Tyler,
> 
> Does MSVC permit empty structures, i.e. structures with no fields? Perhaps with some additional decoration, a la [[msvc::no_unique_address]].
> If so, perhaps that would be a possible workaround for RTE_MARKERs.

i had some pretty long conversations with one of the main msvc devs
about this and they couldn't identify anything that they had that could
be used.

we didn't exhaustively dig through new versions of the standards but
even if there was something there we probably couldn't use it while
still baselined to C11.

i know the inline accessors were not going to be a perfect solution
either for the reason you raise on list. at this point i'm trying to
find a happy medium to solve the problem where everyone doesn't end up
too upset.

even anonymous unions turn out to be an imperfect solution because
there's a corner case they can't cover where the union ends up with a
field that is a FAM.

i even asked if they could just support similar as an extension but they
were pretty firm no. at this point unless enhancements are absolute need
i am not likely to get large investments from msvc (for now). i've spent
an enormous amount of their resources in the last couple of years for
dpdk and they want to see some customers using dpdk before they are able
to commit more.

fortunately i think we have enough now to at least get customers using
dpdk without significant compromises (assuming i can ever get all my
changes upstream).

also in case i haven't said it lately, i appreciate all the review and
input you've given it really helps a lot.

ty


> 
> 
> Med venlig hilsen / Kind regards,
> -Morten Brørup
>