Messages in this thread Patch in this message | | | Date | Fri, 31 Dec 2021 09:54:20 -0700 | From | Nathan Chancellor <> | Subject | Re: [PATCH linux-next] tools: compiler-gcc.h::Keep compatible with non-clang compilers. |
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On Fri, Dec 31, 2021 at 10:08:33AM +0000, cgel.zte@gmail.com wrote: > From: xu xin <xu.xin16@zte.com.cn> > > When HOSTC = gcc (GCC) 4.8.5, there is an error occurring as follows: > error: Undefined __has_attribute. > > This problem is introduced by commit d0ee23f9d78be ("tools: > compiler-gcc.h: Guard error attribute use with __has_attribute").
Yes, sorry for breaking this. It has been discussed here with some ideas for a resolution but I never got any feedback so I never carried it through, thank you for picking it up.
https://lore.kernel.org/r/c1b1a299-c60d-28a4-07ab-1ecd211d6da9@i-love.sakura.ne.jp/
This patch should probably be sent straight to Linus next time it is sent, as he directly applied both my commit and the one that it was fixing. Nick and I do not pick up patches currently although Kees might be willing to take this one.
> To solve it, this patch is given to keep the comatibility.
^ compatibility
Might be worth adding "with older GCC versions" at the end of that sentence.
> Reported-by: Zeal Robot <zealci@zte.com.cn> > Co-developed-by: wangyong <wang.yong12@zte.com.cn> > Signed-off-by: xu xin <xu.xin16@zte.com.cn> > --- > tools/include/linux/compiler-gcc.h | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/tools/include/linux/compiler-gcc.h b/tools/include/linux/compiler-gcc.h > index 8816f06fc6c7..7da593d3cb91 100644 > --- a/tools/include/linux/compiler-gcc.h > +++ b/tools/include/linux/compiler-gcc.h > @@ -16,6 +16,11 @@ > # define __fallthrough __attribute__ ((fallthrough)) > #endif > > + > +#ifndef __has_attribute > +# define __has_attribute(x) 0 /* Compatibility with non-clang compilers. */
This comment is not really accurate; it implies that clang is the only one that defines __has_attribute() but GCC 5.x or newer supports __has_attribute(). A more accurate comment might be:
/* Compatibility with GCC < 5.x */
> +#endif > + > #if __has_attribute(__error__) > # define __compiletime_error(message) __attribute__((error(message))) > #endif > -- > 2.25.1 >
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