Re: [PATCH] Fix ld-version.sh script if LLD was built with LLD_VENDOR

[Nathan Chancellor]

Hi Bernhard,

I have added the ClangBuiltLinux mailing list, kbuild mailing list, and
Masahiro and Nick to CC. Maybe ld-version.sh and cc-version.sh should be
added to a MAINTAINERS entry to make sure we get CC'd (I can send one
along tomorrow).

On Tue, Mar 02, 2021 at 11:12:11PM +0100, Bernhard Rosenkränzer wrote:
> If LLD was built with -DLLD_VENDOR="xyz", ld.lld --version output
> will prefix LLD_VENDOR. Since LLD_VENDOR can contain spaces, the
> LLD identifier isn't guaranteed to be $2 either.

TIL about LLD_VENDOR...

> Adjust the version checker to handle such versions of lld.
> 
> Signed-off-by: Bernhard Rosenkränzer <bero@xxxxxxxxx>
> ---
>  scripts/ld-version.sh | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/scripts/ld-version.sh b/scripts/ld-version.sh
> index a463273509b5..4c042a306e22 100755
> --- a/scripts/ld-version.sh
> +++ b/scripts/ld-version.sh
> @@ -49,6 +49,18 @@ elif [ "$1" = LLD ]; then
>  	min_version=$lld_min_version
>  	name=LLD
>  	disp_name=LLD
> +elif echo "$@" |grep -q ' LLD '; then
> +	# if LLD was built with -DLLD_VENDOR="xyz", it ld.lld --version
> +	# says "xyz LLD [...]". Since LLD_VENDOR may contain spaces, we
> +	# don't know the exact position of "LLD" and the version info
> +	# at this point
> +	while [ "$1" != "LLD" ]; do
> +		shift
> +	done
> +	version=$2
> +	min_version=$lld_min_version
> +	name=LLD
> +	disp_name=LLD
>  else
>  	echo "$orig_args: unknown linker" >&2
>  	exit 1
> -- 
> 2.30.1
> 

I am not sure what a better fix would be of the top of my head but
wouldn't it be better to avoid the duplication? This diff below works
for me with or without LLD_VENDOR defined.

diff --git a/scripts/ld-version.sh b/scripts/ld-version.sh
index a463273509b5..84f9fc741f09 100755
--- a/scripts/ld-version.sh
+++ b/scripts/ld-version.sh
@@ -44,7 +44,10 @@ if [ "$1" = GNU -a "$2" = ld ]; then
 elif [ "$1" = GNU -a "$2" = gold ]; then
 	echo "gold linker is not supported as it is not capable of linking the kernel proper." >&2
 	exit 1
-elif [ "$1" = LLD ]; then
+elif echo "$*" | grep -q LLD; then
+	while [ "$1" != "LLD" ]; do
+		shift
+	done
 	version=$2
 	min_version=$lld_min_version
 	name=LLD