Re: [PATCH] Remove __warn_memset_zero_len [bz #25399]

[Florian Weimer <fweimer@redhat.com>]

* Siddhesh Poyarekar:

> On 11/4/20 3:10 PM, Florian Weimer via Libc-alpha wrote:
>> * Jakub Jelinek:
>> 
>>> It is ok if it doesn't warn anymore, and it is ok if it is not in the
>>> headers anymore, but one can still have object files or *.a libraries
>>> compiled with gcc 4.9 and earlier against older glibc and that will
>>> now fail to link altogether.
>> In general, that is not supported.  We have recently made an
>> exception
>> for __xstat.  But in this case, linking after removal will only fail if
>> there was an annoying linker warning before, so I think it's going to be
>> very rare that this makes a difference.
>
> I suppose another way to look at this is that the patch does not fix
> the link failure, it only ensures that the symbol doesn't appear in
> the future by accident.
>
> We can then look at fixing the link failure by adding the symbol in if
> someone actually cares enough to file another bug.  Does that sound 
> reasonable?

Eh, right.  The __warn_memset_zero_len symbol is currently not part of
libc_nonshared.a.  (Our downstream build of 2.17 still has it, but the
one based on 2.28 does not, due to a different GCC version being used.)
So there is no new backwards compatibility impact from remove the
__warndecl stuff.

Thanks,
Florian
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