Proper Place for builtin_define(__ELF__)

[Joel Sherrill]

On Wed, Jul 21, 2021 at 10:08 PM Jeff Law <jeffreyalaw@gmail.com> wrote:
>
>
>
> On 7/21/2021 6:31 PM, Michael Eager wrote:
> >
> >
> > On 7/21/21 5:22 PM, Joel Sherrill wrote:
> >>
> >>
> >> On Wed, Jul 21, 2021, 7:12 PM Michael Eager <eager@eagercon.com
> >> <mailto:eager@eagercon.com>> wrote:
> >>
> >>     On 7/21/21 2:28 PM, Joel Sherrill wrote:
> >>      > Hi
> >>      >
> >>      > We are in the process of porting RTEMS to the Microblaze and
> >> gcc does
> >>      > not have __ELF__ as a predefine. In looking around at where to
> >>     add it,
> >>      > it looks like there are multiple ways to do it. We see
> >> variations on
> >>      > the following patterns:
> >>      >
> >>      > + dbxelf.h
> >>      > + OS specific header in config/
> >>      > + Arch/OS specific header
> >>      >
> >>      > Integrating dbxelf.h into the microblaze seems risky for one
> >> simple
> >>      > builtin_define(). Adding it to config/microblaze/rtems.h won't
> >>     address
> >>      > the microblaze-elf target.
> >>      >
> >>      > A suggestion on where to add the builtin_predefine is
> >> appreciated.
> >>
> >>     There are very few defines for __ELF__ in the GCC target files.
> >>
> >>
> >> Many  targets include dbxelf.h from the config.gcc script. There are
> >> 130 references to that file there. That seems to be where most
> >> architectures get it.
> >
> > AFAIK, no one has ever tried to build microblaze to generate stabs,
> > and I can't see a good reason why anyone would.  Including dbxelf.h
> > seems wrong.  I don't have an answer why other arch's do that.
> Avoiding dbxelf would be advisable.  We're really only supporting stabs
> for for aix anymore.  We need to start excising dbxelf from all the
> places it's being used.

That will take some work.

What about elfos.h which is referenced 168 times in config.gcc?

Unfortunately, dbxelf.h and elfos.h appear to be used together a lot.
Grep'ing for "dbxelf.h elfos.h" in config.gcc resulted in 128 hits.

--joel

>
> jeff
>