[Openmcl-devel] Invalid CDB Files?

[Phil]

That's great news and I've got a system waiting here for testing  
purposes whenever the snapshot is ready.  Also, per our last  
exchange, I have an open request in with developer relations  but  
have yet to get a response (not holding my breath, but it can't hurt  
to ask)

On Dec 29, 2006, at 2:47 AM, Gary Byers wrote:

> The good news is that I'm getting close to having a releasable  
> interface
> translator that can handle ObjC 2.x syntax.  (I stopped whining and  
> merged
> a couple of gcc branches together.)
>
> The bad news is that I just discovered that the Darwin ppc64 port
> seems to have trouble loading shared libraries under ... post-Tiger
> systems.  The ultimate reason for this has to do with the lisp
> expecting some low-memory pages that contain things like NIL being
> unused until the lisp kernel maps them in from the heap image; there's
> never been any guarantee that the dynamic linker wouldn't decide to
> use those pages for its own evil purposes, and if the lisp steps on
> some dynamic linker data it's not too surprising that loading shared
> libraries or trying to resolve symbols in those libraries starts to
> fail.  The dynamic linker seems glad to map its data elsewhere under
> Tiger and earlier, but that's probably just been blind luck.
>
> The workaround for this involves being more explicit about needing the
> memory pages in question.  For arcane reasons, it'll also involve
> changing the address of NIL (which is assumed to be a constant) and
> that in turn will involve some bootstrapping/chaos.  I'll have to look
> more carefully at the ppc32 and x86-64 Darwin ports: they seem to be
> lucking out (the pages that they assume are free are indeed free), but
> so was the ppc64 until fairly recently.  It might be wise to make a
> similar change to the ppc32 & x86-64 ports as well, rather than trust
> that their luck will hold.
>
> So:
> - total chaos in CVS for a day or two until all hosts/targets agree
>   on where NIL is
> - new snapshots soon after
> - interface translator is a separate/orthogonal issue, but I can
>   probably put together a set of patches relative to Apple's
>   GCC-5363 (sources to which are available on an Apple website.)
>   This would probably only be of interest to people with access
>   to Leopard via ADC; it'd be of even more interest to those people
>   if OpenMCL could reliably load and use shared libraries on
>   platforms of interest.
>