Messages in this thread | | | From | Miguel Ojeda <> | Date | Tue, 27 Oct 2020 10:47:39 +0100 | Subject | Re: [PATCH v2] ctype.h: remove duplicate isdigit() helper |
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On Tue, Oct 27, 2020 at 12:57 AM Arnd Bergmann <arnd@kernel.org> 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`.
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. */
Cheers, Miguel
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