Re: [PATCH RESEND] gcc-plugins: avoid errors with -std=gnu++11 on old gcc

[Masahiro Yamada <masahiroy@kernel.org>]

On Thu, Mar 18, 2021 at 3:26 PM Miguel Ojeda
<miguel.ojeda.sandonis@gmail.com> wrote:
>
> On Thu, Mar 18, 2021 at 7:03 AM Valdis Klētnieks
> <valdis.kletnieks@vt.edu> wrote:
> >
> > Or declare that gcc6 is the minimum for building the kernel.
>
> Cc'ing some interested people in raising GCC's version for one reason
> or another, so that we put this as another one in the pile of reasons
> :-)
>
> https://lore.kernel.org/lkml/CAHk-=wjgvt1Ei72BTrEH5fgfqykVH-AYt56-7yBT8Lcprj7bEg@mail.gmail.com/
>
> Cheers,
> Miguel


Previously we were discussing raising the min GCC
version 5.x,  but not further at this point of time.


We can require GCC 6+ for building GCC plugins.


--- a/scripts/gcc-plugins/Kconfig
+++ b/scripts/gcc-plugins/Kconfig
@@ -8,7 +8,7 @@ config HAVE_GCC_PLUGINS
 menuconfig GCC_PLUGINS
        bool "GCC plugins"
        depends on HAVE_GCC_PLUGINS
-       depends on CC_IS_GCC
+       depends on CC_IS_GCC && GCC_VERSION >= 60000
        depends on $(success,test -e $(shell,$(CC)
-print-file-name=plugin)/include/plugin-version.h)
        default y
        help





BTW, the commit message mentions that
the issues only happen on GCC 4 and 5,
but the added code was:

GCC_FLAVOR = $(call cc-ifversion, -ge, 1100, 11, 98)

  instead of

GCC_FLAVOR = $(call cc-ifversion, -ge, 600, 11, 98)



So, this patch is also requiring to cover two standards:

GCC_VERSION >= 11  :  -std=gnu++11
GCC_VERSION <  11  : -std=gnu++98




-- 
Best Regards
Masahiro Yamada