ABI document

[Florian Weimer]

* H. J. Lu:

> On Wed, Jul 29, 2020 at 4:53 AM Mark Wielaard <mark@klomp.org> wrote:
>>
>> On Wed, 2020-07-29 at 13:47 +0200, Florian Weimer via Gnu-gabi wrote:
>> > Is there an ABI document somewhere for the generic GNU ABI?
>> >
>> > It would eventually collect things like symbol versioning, TLS, and some
>> > of the smaller stuff.  I understand those have been documented
>> > separately so far, but the question is what we should do for new
>> > features?
>>
>> There isn't a formal one specific to the generic GNU ABI. But we can
>> set up a gnu-gabi git repo on sourceware for it, so we can collect
>> those things. Or do you prefer a wiki?
>>
>
> I started one:
>
> https://gitlab.com/x86-psABIs/Linux-ABI

But we are not supposed to talk about GNU there, so I think it's not
helpful for describing GNU features.

If I'm wrong about that and we can document glibc specifics there (such
as DF_GNU_1_UNIQUE), then I guess that's fine, except that you will be
hard-pressed to find a glibc target that implements dynamic linking, but
not these ELF extensions (because they will be in generic code).  So the
processor-independent GNU/Linux ABI isn't really the right place.

These features are also not likely to be implemented by musl, ucLibc,
LLVM libc, even on Linux, because they *are* GNU features, not Linux
platform features.

Thanks,
Florian