Re: [PATCH v4 0/4] tools/build: Allow versioning of all LLVM tools

[Namhyung Kim]

On Fri, Jul 24, 2026 at 07:19:45PM +0200, Kumar Kartikeya Dwivedi wrote:
> On Thu Jul 16, 2026 at 1:46 AM CEST, Namhyung Kim wrote:
> > Hello BPF folks,
> >
> > On Wed, Jul 15, 2026 at 03:53:47PM +0100, James Clark wrote:
> >> I ran into the build issue mentioned in the first commit, because using
> >> an option like LLVM=-15 is a documented way to build [1], but only
> >> some of the LLVM tools defined in tools/ support this.
> >>
> >> After fixing that, a lot of other tidyups fell out. I didn't go too far,
> >> for example some selftests include tools/testing/selftests/lib.mk which
> >> reimplements some of the LLVM_SUFFIX stuff, but other selftests include
> >> tools/scripts/Makefile.include and I stopped before touching the former.
> >> Some other non build scripts hard code toolchains and I didn't touch
> >> those either, this change is only focused on things that already
> >> include Makefile.include.
> >>
> >> [1]: Documentation/kbuild/llvm.rst
> >>
> >> Signed-off-by: James Clark <james.clark@xxxxxxxxxx>
> >> ---
> >> Changes in v4:
> >> - Drop "tools/build: selftests: Allow versioning LLVM lld", clang
> >>   already picks the correct sibling lld version. (Sashiko)
> >> - Link to v3: https://lore.kernel.org/r/20260715-james-perf-llvm-version-v3-0-8854bfe5af7e@xxxxxxxxxx
> >>
> >> Changes in v3:
> >> - Add warning for empty $USE_LD
> >> - Use $HOSTREADELF in bpf Makefile
> >> - Rebase on v7.2-rc3
> >> - Link to v2: https://lore.kernel.org/r/20260518-james-perf-llvm-version-v2-0-f12cc4f031d8@xxxxxxxxxx
> >>
> >> Changes in v2:
> >> - Fix selftests/bpf build. LLD needs to take the full path to be used
> >>   with -fuse-ld=
> >> - Link to v1: https://lore.kernel.org/r/20260514-james-perf-llvm-version-v1-0-6cac1a9a4c8d@xxxxxxxxxx
> >>
> >> ---
> >> James Clark (4):
> >>       tools/build: Allow versioning of all LLVM tools defined in Makefile.include
> >>       tools/build: Indent if else blocks
> >>       tools/build: Allow versioning LLVM readelf
> >>       tools/build: selftests: Remove some duplicate toolchain definitions
> >>
> >>  tools/bpf/resolve_btfids/Makefile    |  3 --
> >>  tools/lib/api/Makefile               |  4 --
> >>  tools/lib/bpf/Makefile               |  8 ++--
> >>  tools/lib/subcmd/Makefile            |  4 --
> >>  tools/lib/symbol/Makefile            |  4 --
> >>  tools/perf/Makefile.perf             |  7 ----
> >>  tools/scripts/Makefile.include       | 77 ++++++++++++++++++++----------------
> >>  tools/testing/selftests/bpf/Makefile |  1 -
> >>  8 files changed, 46 insertions(+), 62 deletions(-)
> >
> > Are you ok with this change and going through perf tree?
> >
> 
> Sorry for the delay, yes, feel free to take it through your tree.

Thanks, can I take it as your Acked-by?

Namhyung