Re: [PATCH RFC] tools: Factor Clang, LLC and LLVM utils definitions

[Andrii Nakryiko]

On Wed, Jan 20, 2021 at 2:36 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> On Sat, Jan 16, 2021 at 10:54:04AM +0100, Sedat Dilek wrote:
> > When dealing with BPF/BTF/pahole and DWARF v5 I wanted to build bpftool.
> >
> > While looking into the source code I found duplicate assignments
> > in misc tools for the LLVM eco system, e.g. clang and llvm-objcopy.
> >
> > Move the Clang, LLC and/or LLVM utils definitions to
> > tools/scripts/Makefile.include file and add missing
> > includes where needed.
> > Honestly, I was inspired by commit c8a950d0d3b9
> > ("tools: Factor HOSTCC, HOSTLD, HOSTAR definitions").
> >
> > I tested with bpftool and perf on Debian/testing AMD64 and
> > LLVM/Clang v11.1.0-rc1.
> >
> > Build instructions:
> >
> > [ make and make-options ]
> > MAKE="make V=1"
> > MAKE_OPTS="HOSTCC=clang HOSTCXX=clang++ HOSTLD=ld.lld CC=clang LD=ld.lld LLVM=1 LLVM_IAS=1"
> > MAKE_OPTS="$MAKE_OPTS PAHOLE=/opt/pahole/bin/pahole"
> >
> > [ clean-up ]
> > $MAKE $MAKE_OPTS -C tools/ clean
> >
> > [ bpftool ]
> > $MAKE $MAKE_OPTS -C tools/bpf/bpftool/
> >
> > [ perf ]
> > PYTHON=python3 $MAKE $MAKE_OPTS -C tools/perf/
> >
> > I was careful with respecting the user's wish to override custom compiler,
> > linker, GNU/binutils and/or LLVM utils settings.
> >
> > Some personal notes:
> > 1. I have NOT tested with cross-toolchain for other archs (cross compiler/linker etc.).
> > 2. This patch is on top of Linux v5.11-rc3.
> >
> > I hope to get some feedback from especially Linux-bpf folks.
> >
> > Signed-off-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
> > ---
> >  tools/bpf/bpftool/Makefile                  | 2 --
> >  tools/bpf/runqslower/Makefile               | 3 ---
> >  tools/build/feature/Makefile                | 4 ++--
> >  tools/perf/Makefile.perf                    | 1 -
>
> for tools/build and tools/perf
>
> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
>

It's pretty straightforward and looks good for bpftool and runqslower,
but I couldn't apply directly to test due to merge conflicts.

Also, which tree this should go through, given it touches multiple
parts under tools/?

> jirka
>
> >  tools/scripts/Makefile.include              | 7 +++++++
> >  tools/testing/selftests/bpf/Makefile        | 3 +--
> >  tools/testing/selftests/tc-testing/Makefile | 3 +--
> >  7 files changed, 11 insertions(+), 12 deletions(-)
> >
> > diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
> > index f897cb5fb12d..71c14efa6e91 100644
> > --- a/tools/bpf/bpftool/Makefile
> > +++ b/tools/bpf/bpftool/Makefile
>
> SNIP
>