[gentoo-dev] Re: [PATCH] gcc-config: Add option to not install cc/f77 wrappers.

[Sergei Trofimovich]

On Mon, 2 Mar 2020 19:03:48 -0800
Manoj Gupta <manojgupta@××××××.com> wrote:

> On Thu, Feb 27, 2020 at 11:20 PM Sergei Trofimovich <slyich@×××××.com>
> wrote:
>
> > On Thu, 27 Feb 2020 at 22:41, Manoj Gupta <manojgupta@××××××.com> wrote:
> > >
> > >
> > >
> > > On Thu, Feb 27, 2020 at 11:22 AM Manoj Gupta <manojgupta@××××××.com>
> > wrote:
> > >>
> > >> gcc-config installs cc/f77 by default. This may be undesired on
> > >> systems that want to set their own versions of cc/f77.
> > >>
> > >> Add option "-n"/"--no-default-vars" to not install the cc/f77
> > >> wrappers.
> > >>
> > >> Signed-off-by: Manoj Gupta <manojgupta@××××××.com>
> > >> ---
> > >>  gcc-config | 6 +++++-
> > >>  1 file changed, 5 insertions(+), 1 deletion(-)
> > >>
> > >> diff --git a/gcc-config b/gcc-config
> > >> index f03a46a..6f306db 100755
> > >> --- a/gcc-config
> > >> +++ b/gcc-config
> > >> @@ -262,7 +262,7 @@ update_wrappers() {
> > >>         # For all toolchains, we want to create the fully qualified
> > >>         # `tuple-foo`.  Only native ones do we want the simple `foo`.
> > >>         local all_wrappers=( ${new_wrappers[@]/#/${CTARGET}-} )
> > >> -       if ! is_cross_compiler ; then
> > >> +       if ! is_cross_compiler && [[ "${DEFAULT_PROGS}" == "yes" ]];
> > then
> > >>                 all_wrappers+=( "${new_wrappers[@]}" )
> > >>                 # There are a few fun extra progs which we have to
> > handle #412319
> > >>                 all_wrappers+=( cc:gcc f77:g77 )
> > >> @@ -951,6 +951,7 @@ FORCE="no"
> > >>  CC_COMP=
> > >>  ENV_D="${EROOT}etc/env.d"
> > >>  GCC_ENV_D="${ENV_D}/gcc"
> > >> +DEFAULT_PROGS="yes"
> > >>
> > >>  for x in "$@" ; do
> > >>         case "${x}" in
> > >> @@ -972,6 +973,9 @@ for x in "$@" ; do
> > >>                 -l|--list-profiles)
> > >>                         set_doit list_profiles
> > >>                         ;;
> > >> +               -n|--no-default-vars)
> > >> +                       DEFAULT_PROGS="no"
> > >> +                       ;;
> > >>                 -S|--split-profile)
> > >>                         if [[ ( $1 != "-S" && $1 != "--split-profile" )
> > || $# -eq 1 ]] ; then
> > >>                                 usage 1
> > >> --
> > >>
> > >
> > > Not sure of the correct mailing list for patches to gcc-config so also
> > adding toolchain@gentoo .
> > >
> >
> > toolchain@g.o should generally be fine.
> >
> > Today cc->gcc and gcc->${CHOST}-gcc symlinks are effectively owned by
> > a single sys-devel/gcc-config package.
> > gcc-config is calld to update symlinks every time sys-devel/gcc is
> > installed/updated. That way we never get cc/gcc
> > out of sync.
> >
> > Your change makes /usr/bin/cc an orphan symlink. I think we need to
> > still keep a 'cc'/'f77' ownership somewhere
> > (say, a separate package).
> >
> > I suggest making a decision to handle or not handle 'cc'/'f77' and
> > gcc-config build-time, not gcc-config call-time.
> > That way sys-devel/gcc updates will behave the same as manual
> > 'gcc-config-' calls.
> >
> > Mechanically that could be a Makefile variable that switches the
> > behaviour on/off at
> > https://gitweb.gentoo.org/proj/gcc-config.git/tree/Makefile
> > and exposed as an USE flag on sys-devel/gcc-config ebuild.
> >
> > Later we can create a separate ebuild to manage /usr/bin/cc. For gcc
> > it's not hard, as gcc-config always provides /usr/bin/gcc and
> > /usr/bin/${CHOST}-gcc.
> > These can be static symlinks that don't require maintenance updates.
> >
> > Thanks for the suggestion. I will look into adding a Makefile variable
> exposed via an USE flag.

You might also need to look in the detail at 'c++', 'cpp' and ${CHOST}-* equivalents
as those also get linked by gcc-config:

$ LANG=C ls -l /usr/bin/ | fgrep 10.0.1 | fgrep -v -- '-10.0.1 ->'
lrwxrwxrwx   1 root root           43 Feb  4 10:45 c++ -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/c++
lrwxrwxrwx   1 root root           43 Feb  4 10:45 cc -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gcc
lrwxrwxrwx   1 root root           43 Feb  4 10:45 cpp -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/cpp
lrwxrwxrwx   1 root root           43 Feb  4 10:45 g++ -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/g++
lrwxrwxrwx   1 root root           43 Feb  4 10:45 gcc -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gcc
lrwxrwxrwx   1 root root           46 Feb  4 10:45 gcc-ar -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gcc-ar
lrwxrwxrwx   1 root root           46 Feb  4 10:45 gcc-nm -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gcc-nm
lrwxrwxrwx   1 root root           50 Feb  4 10:45 gcc-ranlib -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gcc-ranlib
lrwxrwxrwx   1 root root           45 Feb  4 10:45 gccgo -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gccgo
lrwxrwxrwx   1 root root           44 Feb  4 10:45 gcov -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gcov
lrwxrwxrwx   1 root root           49 Feb  4 10:45 gcov-dump -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gcov-dump
lrwxrwxrwx   1 root root           49 Feb  4 10:45 gcov-tool -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gcov-tool
lrwxrwxrwx   1 root root           48 Feb  4 10:45 gfortran -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gfortran
lrwxrwxrwx   1 root root           45 Feb  4 10:45 go-10 -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/go-10
lrwxrwxrwx   1 root root           48 Feb  4 10:45 gofmt-10 -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gofmt-10
lrwxrwxrwx   1 root root           48 Feb  4 10:45 lto-dump -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/lto-dump
lrwxrwxrwx   1 root root           63 Feb  4 10:45 x86_64-pc-linux-gnu-c++ -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/x86_64-pc-linux-gnu-c++
lrwxrwxrwx   1 root root           63 Feb  4 10:45 x86_64-pc-linux-gnu-cpp -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/x86_64-pc-linux-gnu-cpp
lrwxrwxrwx   1 root root           63 Feb  4 10:45 x86_64-pc-linux-gnu-g++ -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/x86_64-pc-linux-gnu-g++
lrwxrwxrwx   1 root root           63 Feb  4 10:45 x86_64-pc-linux-gnu-gcc -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/x86_64-pc-linux-gnu-gcc
lrwxrwxrwx   1 root root           66 Feb  4 10:45 x86_64-pc-linux-gnu-gcc-ar -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/x86_64-pc-linux-gnu-gcc-ar
lrwxrwxrwx   1 root root           66 Feb  4 10:45 x86_64-pc-linux-gnu-gcc-nm -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/x86_64-pc-linux-gnu-gcc-nm
lrwxrwxrwx   1 root root           70 Feb  4 10:45 x86_64-pc-linux-gnu-gcc-ranlib -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/x86_64-pc-linux-gnu-gcc-ranlib
lrwxrwxrwx   1 root root           65 Feb  4 10:45 x86_64-pc-linux-gnu-gccgo -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/x86_64-pc-linux-gnu-gccgo
lrwxrwxrwx   1 root root           64 Feb  4 10:45 x86_64-pc-linux-gnu-gcov -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/x86_64-pc-linux-gnu-gcov
lrwxrwxrwx   1 root root           49 Feb  4 10:45 x86_64-pc-linux-gnu-gcov-dump -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gcov-dump
lrwxrwxrwx   1 root root           49 Feb  4 10:45 x86_64-pc-linux-gnu-gcov-tool -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gcov-tool
lrwxrwxrwx   1 root root           68 Feb  4 10:45 x86_64-pc-linux-gnu-gfortran -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/x86_64-pc-linux-gnu-gfortran
lrwxrwxrwx   1 root root           45 Feb  4 10:45 x86_64-pc-linux-gnu-go-10 -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/go-10
lrwxrwxrwx   1 root root           48 Feb  4 10:45 x86_64-pc-linux-gnu-gofmt-10 -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/gofmt-10
lrwxrwxrwx   1 root root           48 Feb  4 10:45 x86_64-pc-linux-gnu-lto-dump -> /usr/x86_64-pc-linux-gnu/gcc-bin/10.0.1/lto-dump

> Regarding the separate ebuild, I hope someone more knowledgeable
> than me regarding ebuilds can handle that.

How do you plan to manage those symlinks meanwhile?

-- 

  Sergei