[PATCH v2] Use C99-compliant scanf under _GNU_SOURCE with modern compilers.

[Joseph Myers]

On Thu, 22 Feb 2018, Zack Weinberg wrote:

> On a related note, the interaction of the C99/not-C99 scanf redirect
> with the __LDBL_COMPAT scanf redirect was complicated, confusing, and
> possibly wrong.  I tried to match the intent rather than the letter of
> the previous behavior.  I do not have access to physical hardware for
> which __LDBL_COMPAT is relevant, so my ability to test it is limited.
> Careful review and maybe even some volunteer testing would be
> appreciated.

According to <https://gcc.gnu.org/wiki/CompileFarm> there are powerpc64 
systems (both BE and LE - -mlong-double-64 is supported for both of those) 
running CentOS 7 in the GCC Compile Farm, which should be suitable for 
glibc testing.  (Note that the glibc testsuite has essentially no coverage 
for -mlong-double-64 at present.)

-- 
Joseph S. Myers
joseph@codesourcery.com