Re: Objective C threads on NetBSD 4.0 i386

[David Ayers]

Richard Frith-Macdonald wrote:
> On 6 Jan 2008, at 17:19, David Wetzel wrote:
>
> > Hi,
> >
> >  objc_thread_detach (@selector(hash), o, nil);
> >
> > returns NULL on all boxes. Also on NetBSD 3.1 where NSThread is 
> > working with GNUstep.
> >
> > Any Ideas?
>
> I don't see how that's possible unless you are linking something wrong 
> ... if objc_thread_detach() returns NULL then NSThread cannot work ... 

It doesn't actually return NULL on NetBSD 3.1.  There seems to be a 
promotion/printf issue, undefined behavior or some serious bug.  For:

printf("return value is %p %d\n int:%d retval:%d NULL:%d, COMP:%d\n",
          retval, (retval == NULL),
          sizeof(int), sizeof(retval),
          sizeof(NULL), sizeof(retval==NULL));

I get:

return value is 0xbb000000 0
 int:4 retval:4 NULL:4, COMP:4

> since it is based on objc_thread_detach() and will raise an exception if 
> that returns NULL (since NULL is the error return from that function ... 
> not a great piece of design, but it's what the objc runtime provides).

But on the 4.0 version we really get 0x0.  Now I'll poke a bit but I 
think Dave W. will actually have to install a debug version of 
gcc/libobjc for me to figure out what's going on here.

Cheers,
David