Re: [PATCH v1] compiler.h: define CONFIG_GCC_VERSION

[Jan Beulich <jbeulich@xxxxxxxx>]

On 18.06.2021 18:42, Olaf Hering wrote:
> --- a/xen/include/xen/compiler.h
> +++ b/xen/include/xen/compiler.h
> @@ -99,6 +99,13 @@
>      __asm__ ("" : "=r"(__ptr) : "0"(ptr));      \
>      (typeof(ptr)) (__ptr + (off)); })
>  
> +#ifndef CONFIG_GCC_VERSION
> +# ifdef __GNUC__
> +#  define CONFIG_GCC_VERSION (__GNUC__ * 10000           \
> +                              + __GNUC_MINOR__ * 100     \
> +                              + __GNUC_PATCHLEVEL__)
> +# endif
> +#endif
>  #if CONFIG_GCC_VERSION >= 110000 /* See gcc bug 100680. */
>  # define gcc11_wrap(x) RELOC_HIDE(x, 0)
>  #else

Having thought about it, this feels like the wrong solution to
me: I'd rather not see us introduce further CONFIG_* which don't
really come from Kconfig. The more when we have an even simpler
alternative:

there's no CONFIG_GCC_VERSION

This was introduced in 4.14 only.

Reported-by: Olaf Hering <olaf@xxxxxxxxx>
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/include/xen/compiler.h
+++ b/xen/include/xen/compiler.h
@@ -99,7 +99,7 @@
     __asm__ ("" : "=r"(__ptr) : "0"(ptr));      \
     (typeof(ptr)) (__ptr + (off)); })
 
-#if CONFIG_GCC_VERSION >= 110000 /* See gcc bug 100680. */
+#if __GNUC__ >= 11 /* See gcc bug 100680. */
 # define gcc11_wrap(x) RELOC_HIDE(x, 0)
 #else
 # define gcc11_wrap(x) (x)

I'll also adjust the original backport itself before putting it
on the 4.12 branch (where I think we want both this and the other
gcc 11 fixes).

Jan