[PATCH] elf.h: Add ELFCOMPRESS_ZSTD

[Fangrui Song]

On 2022-07-29, Carlos O'Donell wrote:
>On 7/26/22 16:30, Fangrui Song wrote:
>> On Tue, Jul 26, 2022 at 1:24 PM Adhemerval Zanella Netto
>> <adhemerval.zanella@linaro.org> wrote:
>>>
>>>
>>>
>>> On 22/07/22 20:08, Fangrui Song via Libc-alpha wrote:
>>>> On 2022-07-18, Carlos O'Donell via Libc-alpha wrote:
>>>>> On 7/11/22 00:58, Florian Weimer via Libc-alpha wrote:
>>>>>> * Fangrui Song via Libc-alpha:
>>>>>>
>>>>>>> I wish that the macro definition can catch up the upcoming
>>>>>>> https://sourceware.org/glibc/wiki/Release/2.36 [1], so that
>>>>>>> projects can expect the value ELFCOMPRESS_ZSTD from elf.h.
>>>>>>> The projects may choose to define the macro themselves,
>>>>>>> but having the definition in an earlier release seems a good idea
>>>>>>> anyway, and it the glibc definition makes it clearer ELFCOMPRESS_ZSTD
>>>>>>> is standard and vendors can start adding support.
>>>>>>>
>>>>>>> [1]: https://sourceware.org/pipermail/libc-alpha/2022-July/140352.html
>>>>>>> ("Release of glibc 2.36 in 1 month! Please add blockers and desirable for release.")
>>>>>>
>>>>>> This looks quite backportable to me, so it should not be a release
>>>>>> blocker.  It's only a blocker if we apply the patch today, then we'd
>>>>>> have to wait until the gABI assignment actually happens as expected.
>>>>>
>>>>> Agreed. This is a NACK from me as the RM until the gABI assignment happens.
>>>>>
>>>>
>>>> Cary has accepted this value: https://groups.google.com/g/generic-abi/c/satyPkuMisk/m/KwTF_U8rBAAJ
>>>> (Thanks!)
>>>>
>>>> Ed Maste from FreeBSD wants to define this in FreeBSD.
>>>>
>>>> Shall we define it for glibc as well? :)
>>>
>>> I think this is ok, we are already fixing bad designs so we most likely need
>>> more time for testing.
>>
>> Thanks.  Now that it is approved, the commit message can be changed to
>> the following if you want to push it to the 2.36 release branch.
>>
>> elf.h: Add ELFCOMPRESS_ZSTD
>>
>> From the approved generic ABI proposal
>> https://groups.google.com/g/generic-abi/c/satyPkuMisk
>> ("Add new ch_type value: ELFCOMPRESS_ZSTD").
>
>Cary,
>
>Is there a public repo that I can use to cross-check the glibc value with
>the accepted ELF gABI value?
>
>A public repo would make the process of adding matching constants
>easier because I could review what went into the public repository.
>
>Fangrui,
>
>Just for clarity, I don't consider this a release blocker for 2.36.

Cary pushed a similar change to binutils-gdb
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=03d0ae791f7dca2006b924e90ee4e4944b848260

Cary mentioned it on the musl mailing list
https://www.openwall.com/lists/musl/2022/08/03/3 "Yes, this is officially approved."