ffcall/libffi for NetBSD/SPARC (was: Re: Objective-C programming)

[David Ayers]

Adam Fedor schrieb:
> 
> On Sep 30, 2005, at 2:45 PM, Mehul N. Sanghvi wrote:
> 
>>
>> As far as I can tell, there isn't a ffi library on NetBSD, at least I
>> don't see on in /usr/pkgsrc.  Does it come as part of gnustep-base ?
>>
> 
> I think there might be a bug in ffcall for NetBSD/Sparc, but I'll have
> to look around to remember that. I don't think ffi is an  option, but
> it's possible - it comes with gcc, so you would have to look to see if
> there is, say, a gcc-libffi package or perhaps compile from source (if
> it works on your OS).
> 

Hello Folks,

Riccardo and I have attempted to track down NetBSD/SPARC's ffcall issues
(I'm not sure anymore whether our issues are limited to the 64 bit
versions).  AFAIR there is no support in gcc's libffi for NetBSD/SPARC
and ffcall's configure script relies on code using undefined behavior to
determine aspects such as whether small structs are returned via
registers.  When I tried to distill this I even found differing results
dependent on optimization levels.

I wanted to add an explicit configure flag but it seems that changing
configure scripts for ffcall is a non trivial task involving special
directory layout and cross compilers.

I think it will take someone with more intimate knowledge of the ABI
issues of NetBSD/SPARC and the time to dig into ffcall (incl. it's
autoconf machinery) to actually port ffcall to NetBSD/SPARC(64).  Maybe
it will be easier to port libffi for someone familiar with
NetBSD/SPARC(64), but I really just don't know.

Cheers,
David