Re: ambiguous file formats coff-x86_64 / pe-x86_64

["Jan Beulich" <JBeulich at suse dot com>]

>>> On 03.01.17 at 11:27, <amodra@gmail.com> wrote:
> On Tue, Jan 03, 2017 at 12:32:37AM -0700, Jan Beulich wrote:
>> >>> On 22.12.16 at 22:49, <amodra@gmail.com> wrote:
>> > On Thu, Dec 22, 2016 at 07:43:39AM -0700, Jan Beulich wrote:
>> >> binary. We've now had reports that on binutils with both coff-x86_64
>> >> and pe-x86_64 configured in (but defaulting to ELF), linking fails due
>> >> to the object being ambiguous.
>> > 
>> > match_priority was invented for exactly this sort of situation.
>> 
>> Interesting: I don't see how that would help here, as I don't see
>> why (and on what basis) to "prefer" one variant over the other.
>> Looking over the source, at least relocation addend handling is
>> different between the two, and without other (sideband?) info
>> I don't think one can guess the format to be used. The situation
>> in our case is different, because we don't care which of the two
>> gets used, ad we don't care about their differences.
> 
> Hmm, I wonder why coff-x86_64.c has
> 
> #ifdef PE
> #define amd64coff_object_p pe_bfd_object_p
> #else
> #define amd64coff_object_p coff_object_p
> #endif
> 
> and not #ifdef COFF_WITH_PE?

Indeed I had been surprised by this apparent inconsistency too,
but I've assumed whoever wrote this knew why (s)he was doing
it this way. But then I don't think changing the symbol used would
affect the behavior which is problematic to us.

Jan