"Iain Buclaw via Digitalmars-d"  wrote in message news:mailman.4161.1420481405.9932.digitalmars-d@puremagic.com...

> >
> > I think I've got a handle on this, sort of.  I've moved the declaration of
> > __va_argsave into the glue layer, and added intrinsic detection for
> > va_start/va_end/va_arg (the two-arg form).
> >
> > I've implemented them in the backend for win32 and they have passed a simple
> > test!
> >

I now have it working (and tested) for win32/linux32/linux64.  va_start and va_copy will probably both need intrinsics, but druntime's va_arg is fine. On x86_64 all I do is completely ignore the second parameter to va_start and memcpy the fields in.

I haven't done va_copy yet, but it should be fairly simple.

> > Do you think we can change _all_ the druntime and phobos code to just use
> > va_arg directly?  It would be nice to have it all portable like that.
>
> Oh, yeah, do it!  You have references to __va_argsave in phobos, don't you?

There are a _lot_ in lifetime.d.  These should have been replaced with non-variadic versions years ago, so I'm going to do that instead of trying to un-hack them.

https://github.com/D-Programming-Language/dmd/pull/4303
https://github.com/D-Programming-Language/druntime/pull/1102 

"Iain Buclaw via Digitalmars-d"  wrote in message news:mailman.4161.1420481405.9932.digitalmars-d@puremagic.com...

> > Do you think we can change _all_ the druntime and phobos code to just use
> > va_arg directly?  It would be nice to have it all portable like that.
>
> Oh, yeah, do it!  You have references to __va_argsave in phobos, don't you?

Here it is: https://github.com/D-Programming-Language/phobos/pull/2926

__va_argsave wasn't used here, but it was creating its own __va_argsave_t in order to abuse va_arg!