Re: [PATCH 2/2] arch: mips: Fix non-POSIX regexp

[Masahiro Yamada]

On Thu, Jul 8, 2021 at 5:57 PM H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote:
>
> When cross compiling a MIPS kernel on a BSD based HOSTCC leads
> to errors like
>
>   SYNC    include/config/auto.conf.cmd - due to: .config
> egrep: empty (sub)expression
>   UPD     include/config/kernel.release
>   HOSTCC  scripts/dtc/dtc.o - due to target missing
>
> It turns out that egrep uses this egrep pattern:
>
>                 (|MINOR_|PATCHLEVEL_)
>
> This is not valid syntax or gives undefined results according
> to POSIX 9.5.3 ERE Grammar
>
>         https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html
>
> It seems to be silently accepted by the Linux egrep implementation
> while a BSD host complains.
>
> Such patterns can be replaced by a transformation like
>
>         "(|p1|p2)" -> "(p1|p2)?"
>
> Fixes: 48c35b2d245f ("[MIPS] There is no __GNUC_MAJOR__")
> Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
> ---

Applied to linux-kbuild/fixes.
Thanks.



>  arch/mips/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/mips/Makefile b/arch/mips/Makefile
> index 258234c35a096..674f68d16a73f 100644
> --- a/arch/mips/Makefile
> +++ b/arch/mips/Makefile
> @@ -321,7 +321,7 @@ KBUILD_LDFLAGS              += -m $(ld-emul)
>
>  ifdef CONFIG_MIPS
>  CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -x c /dev/null | \
> -       egrep -vw '__GNUC_(|MINOR_|PATCHLEVEL_)_' | \
> +       egrep -vw '__GNUC_(MINOR_|PATCHLEVEL_)?_' | \
>         sed -e "s/^\#define /-D'/" -e "s/ /'='/" -e "s/$$/'/" -e 's/\$$/&&/g')
>  endif
>
> --
> 2.31.1
>


-- 
Best Regards
Masahiro Yamada