Legacy _IO_* symbols and Flaot128 transition

[Florian Weimer]

On 06/29/2018 05:26 PM, Gabriel F. T. Gomes wrote:
> On Fri, 29 Jun 2018, Florian Weimer wrote:
> 
>> libio exports a bunch of symbols for historic reasons:
>>
>> _IO_fprintf
>> _IO_printf
>> _IO_sprintf
>> _IO_sscanf
>> _IO_vfprintf
>> _IO_vfscanf
>> _IO_vsprintf
>>
>> These aren't compat symbols yet, but will not be in installed headers
>> for glibc 2.28.  Zack's cleanup patches only turns _IO_vfscanf into a
>> compat symbol (in “Add __vfscanf_internal and __vfwscanf_internal with
>> flags arguments.”).
>>
>> I think we should turn all of them into compat symbols and drop their
>> compatibility wrappers from nldbl_nonshared.a, and avoid adding
>> binary128 compatibility wrappers for them.
> 
> Should they be turned into compat symbols *because* they won't be
> installed headers (and we don't want new user code linking against them)?
> Or is there something else to it?

No, it's just a cleanup, and to clarify what's necessary for future work.

I also want to add some minimal test for libnldbl_nonshared.a, and 
reducing its size helps with that.  (I'm aware that on ppc64, the 
current toolchain doesn't support long double as double anymore, but I 
can just lie to the compiler and use double instead, I guess.)

> As for binary128 compatibility wrappers for them, I agree (I haven't
> created these on my branch, so this should already be in sync with your
> suggestions).

Good to know.

Florian