ia64 vtable entries (was: C implementations of the C++ ABI)

[Jim Dehnert]

> From: Christophe de Dinechin <ddd at cup.hp.com>
> 
> Jason Merrill wrote:
> > 
> > >>>>> Mark Mitchell <mark at codesourcery.com> writes:
> > 
> >  >   o GP/address pairs in vtables
> > 
> >  >     This one concerns me the most.  I don't even know if there's
> >  >     any kind of standard assembly syntax for this.  Is there?
> >  >     (If not, there should be -- otherwise, you can't say -S to your
> >  >     compiler and get anything sensible out.)
> > 
> > Richard Henderson still doesn't believe that there's a suitable reloc for
> > this in the base ABI, and apparently I forgot to write up his explanation
> > for a wider audience.  Richard, care to repeat it in a less transient
> > medium?
> 
> Ah, here is the text:
> 
> Richard Henderson of Cygnus points out that the IA-64 relocations don't
> really support doing this.  However, the R_IA_64_IPLT*SB relocations do
> perform the correct action.  The problem is that they are currently
> specified to be valid only in executables and shared objects.  I
> believe that the problem can be solved by simply removing this
> restriction.  The static linker support required shouldn't be major --
> it would presumably just pass the relocations through to the linked
> object and let the dynamic linker deal with them.
> 
> Did this change?

The ABI group thought this was reasonable at its last meeting.  I've
submitted proposed replacement wording for the description of
R_IA_64_IPLT*SB with the effect of allowing them in relocatable
objects, and the ABI group members should be doing any necessary
checking with their linker and C++ people with the intent of resolving
this at our next meeting (mid-March).

Jim

-	    Jim Dehnert		dehnert at sgi.com
				(650)933-4272