Re: [PATCH v2] ctype.h: remove duplicate isdigit() helper

[Arnd Bergmann]

On Tue, Oct 27, 2020 at 10:47 AM Miguel Ojeda
<miguel.ojeda.sandonis@xxxxxxxxx> wrote:
>
> On Tue, Oct 27, 2020 at 12:57 AM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
> >
> > +#ifdef __has_builtin
> > +#define has_builtin(x) __has_builtin(x)
> > +#else
> > +#define has_builtin(x) (0)
> > +#endif
>
> Could this be
>
>     #ifndef __has_builtin
>     # define __has_builtin(x) 0
>     #endif
>
> ? i.e. mimicking what we do for `__has_attribute`.

Ah, I didn't know about that

> It would also be a nice idea to put a reminder comment like:
>
>     /*
>      * __has_builtin is supported on gcc >= 10, clang >= 3 and icc >= 21.
>      * In the meantime, to support gcc < 10, we implement __has_builtin
>      * by hand.
>      */

Sounds good, I'll take that. Are the clang and icc version numbers
the actual ones we should list here, or is this just an example?

       Arnd