Re: [PATCH]: Make Sparc Target Multi-Arch

[Michael Snyder <msnyder at cygnus dot com>]

Peter.Schauer wrote:
> 
> > > As the problematic calls are rare (Sun cc compiled 32 bit 
> > > ABI functions, returning structs), I think that we could 
> > > live with a warning and returning garbage in the return value.
> > > Personally I'd prefer that over AT_ENTRY hacking.
> >
> > Ah!  So you're saying this is a concern for Sparc32, but not
> > for Sparc64?
> > Then I have a solution.  I can easily use ON_STACK for Sparc32,
> > and AT_ENTRY_POINT for Sparc64.  That's the beauty of multi-arch! 
> >
> > Then the only losers will be people who activate C2 security 
> > on Sparc32.
> >
> > What do you think?
> 
> I don't have access to a v9 ABI, but looking at the generated v9
> code this seems to be a problem with Sparc32 only.
> 
> How hard would it be to default to AT_ENTRY for Sparc32 and make
> ON_STACK a user selectable option ?

Hmm, perhaps not impossible, but not trivial.  The gdbarch structs
get set up one time.  You'd have to change them on the fly.

As this user-selectability is an enhancement, how about if I make
it ON_STACK for 32, AT_ENTRY_POINT for 64, and check it in?  It
will be no worse for 32 than it is now, and much better for 64
(not to mention the 32/64 combo).  Then whoever wants to can
investigate making ON_STACK a user option for 32 at leisure.

				Michael