Sourceware mitigating and preventing the next xz-backdoor

[Jonathan Wakely]

On Wed, 3 Apr 2024 at 15:34, Martin Uecker via Gcc <gcc@gcc.gnu.org> wrote:
> I ask a very specific question: To what extend is testing
> for features instead of semantic versions and/or supported
> standards still necessary?  This seems like a problematic approach
> that  may have been necessary decades ago, but it seems it may be
> time to move on.


What standard or version should I check for to detect nl_langinfo_l
support? It's in POSIX 2017 but macOS supports it in <xlocale.h>
despite not being POSIX 2017 compliant.

What about _get_osfhandle? Or fwrite_unlocked?

What about whether the platform ABI allows aligning global objects to
the cacheline size?

Those are just a few of the most recent autoconf checks I've written
for libstdc++ in the past few months, not decades ago.