Re: [PATCH] PowerPC64 ELFv2 ABI 2/6: Remove function descriptors

["Ulrich Weigand" <uweigand at de dot ibm dot com>]

Joseph Myers wrote:
> On Wed, 13 Nov 2013, Ulrich Weigand wrote:
> 
> > However, there are assembler files where none of this applies.  This is
> > typically files that define only data objects.  We had thought to maybe
> > force these to use .abiversion, but it turns out that this would have
> > required annoying changes (even in glibc we have platform-independent
> > assembler source files defining data --- these would have had to be
> > patched with powerpc-specific code), for no real good reason: such
> > files (data only) are actually compatible with either ABI anyway!
> 
> On ARM, we found that putting .eabi_attribute directives in sysdep.h (to 
> specify required and maintained stack alignment, a similar case where 
> default assembler output isn't compatible with compiler output) covered 
> almost all assembly sources in glibc, leaving only a handful of .S files 
> needing such directives directly in the .S file.

I guess it couldn't hurt to put a .abiversion in sysdep.h, thanks for
the tip!  But the problem isn't really glibc in itself, I was just
using this as example.

In the end we'll have to rebuild a whole distribution for powerpc64le,
and we'd really like to avoid anything that makes this harder than it
already is.  Having a mandatory requirement that all assembler files
*must* be marked doesn't seem a good idea to me (in particular if there
is no real good reason anyway, as mentioned above).

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU/Linux compilers and toolchain
  Ulrich.Weigand@de.ibm.com