Re: [PATCH 2/2] libc-abis: Define ABSOLUTE ABI [BZ #19818][BZ #23307]

["Maciej W. Rozycki" <macro@mips.com>]

On Thu, 28 Jun 2018, Maciej W. Rozycki wrote:

> > > +  /* Mark that we need support for absolute symbols in the dynamic loader.
> > > */
> > > +  if (htab != NULL && htab->use_absolute_zero)
> > > +    i_ehdrp->e_ident[EI_ABIVERSION] = MIPS_LIBC_ABI_ABSOLUTE;
> > > +
> > >     _bfd_elf_post_process_headers (abfd, link_info);
> > >   }
> > >   and then `htab->use_absolute_zero' will be TRUE iff a GOT relocation has
> > > been calculated to actually refer to a specially-created absolute symbol
> > > used to address the issue covered by binutils PR ld/21375.
> > > 
> > >   The flag will be FALSE if code has been relaxed to avoid referring the
> > > GOT (by using immediate zero instead), in which case no absolute symbol
> > > will have been specially created.
> > > 
> > >   Does this explanation clear your concern?
> > 
> > Yes, I think this is okay then.
> 
>  Great!

 Any further input?  Have we reached consensus?

 If so, then I think a NEWS entry will be due, such as:

* The maximum libc ABI supported has been increased to reflect absolute
  symbol support.  This can be used by the static linker in the ELF file
  header's EI_ABIVERSION field to indicate such support is required.

which I will include in the actual commit.

  Maciej