On 22/10/2021 11:47, Lin Liu wrote:
> diff --git a/xen/include/xen/compiler.h b/xen/include/xen/compiler.h
> index 696c7eb89e..68f28082a5 100644
> --- a/xen/include/xen/compiler.h
> +++ b/xen/include/xen/compiler.h
> @@ -179,4 +179,16 @@
> # define CLANG_DISABLE_WARN_GCC_COMPAT_END
> #endif
>
> +#if (!defined(__clang__) && (__GNUC__ < 10))
This too lost my feedback.
It needs to be #ifndef __has_builtin because otherwise a random GCC 10
build I have fails with:
/local/security/xen.git/xen/include/xen/byteswap.h:6:19: error: missing
binary operator before token "("
6 | #if !__has_builtin(__builtin_bswap16)
I suspect it was a build of GCC 10 before __has_builtin() support was
added, but either way, we should be predicating on __has_builtin itself,
not version guesswork.
~Andrew
