On Tue, 22 Jan 2019, Richard Biener wrote:
> > Or instead just come up with target specific strings to determine the ABI,
> > say i386, x86_64 and x32 for the 3 ABIs on x86, powerpc{,64}{,le} on rs6000
> > etc.
>
> Yeah, I would even suggest to use a target hook multilib_ABI_active_p
> (const char *)
> for this ... (where the hook should diagnose unknown multilib specifiers).
A header from a newer glibc version, supporting new ABIs, should still be
usable with an older GCC version, not supporting some of those ABIs.
Thus I don't think the hook should diagnose unknown specifiers from such a
header. (This is just like how a C header can test new predefined macros
without an old GCC complaining it doesn't know what would define those
macros.)
--
Joseph S. Myers
jos...@codesourcery.com
