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

[Masahiro Yamada]

On Wed, Mar 3, 2021 at 1:02 PM Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
>
> 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



You do not need to use grep.
How about this?




        ...
else
        while [ $# -gt 1 -a "$1" != "LLD" ]; do
               shift
        done

        if [ "$1" = LLD ]; then
                version=$2
                min_version=$lld_min_version
                name=LLD
                disp_name=LLD
        else
                echo "$orig_args: unknown linker" >&2
                exit 1
        fi
fi




-- 
Best Regards
Masahiro Yamada