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

[Andreas Kemnade]

On Sat,  3 Jul 2021 15:48:38 +0200
"H. Nikolaus Schaller" <hns at goldelico.com> wrote:

> When cross compiling a MIPS kernel on a BSD based HOSTCC leads
> to errors like
> 
> #
> # configuration written to .config
> #
>   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 according to POSIX 9.5.3 ERE Grammar
> 
> 	https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html
> 
> but seems to be silently accepted by the Linux egrep implementation
> while a BSD host complains.
> 
> They can be replaced by a transformation like
> 
> 	"(|p1|p2)" -> "(p1|p2)?"
> 
looks sane as the other patch.

Fixes: 48c35b2d245f ("[MIPS] There is no __GNUC_MAJOR__")


> Signed-off-by: H. Nikolaus Schaller <hns at goldelico.com>
> ---
>  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
>