Perf tool build with clang/llvm support broken

Perf tool build with clang/llvm support broken

[Thomas Richter]

I would like to build the perf tool with LLVM/CLANG support and did

# make LIBCLANGLLVM=1 
  BUILD:   Doing 'make -j2' parallel build
  Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs...
  ... some more similar lines removed.

  Makefile.config:1120: No suitable libLLVM found, disabling builtin clang and LLVM support. 
  Please install llvm-dev(el) (>= 3.9.0)

However when I check llvm packages, I do have them installed on that machine:

 # rpm -qa | grep llvm
 llvm-libs-16.0.3-1.fc38.x86_64
 llvm-16.0.3-1.fc38.x86_64
 llvm-test-16.0.3-1.fc38.x86_64
 llvm-static-16.0.3-1.fc38.x86_64
 llvm-devel-16.0.3-1.fc38.x86_64

 # rpm -qa | grep clang
 clang-resource-filesystem-16.0.3-1.fc38.x86_64
 clang-libs-16.0.3-1.fc38.x86_64
 clang-tools-extra-16.0.3-1.fc38.x86_64
 clang-16.0.3-1.fc38.x86_64
 clang-devel-16.0.3-1.fc38.x86_64
 git-clang-format-16.0.3-1.fc38.x86_64
[root@f38 ~]#

This shows up on s390x and x86_64 (my virtual machine).
Any ideas have to fix this? Am I missing a package?

Thanks.
-- 
Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
--
Vorsitzender des Aufsichtsrats: Gregor Pillen
Geschäftsführung: David Faller
Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294

Re: Perf tool build with clang/llvm support broken

[Ian Rogers]

On Tue, Jul 11, 2023 at 3:22 AM Thomas Richter <tmricht@linux.ibm.com> wrote:
>
> I would like to build the perf tool with LLVM/CLANG support and did
>
> # make LIBCLANGLLVM=1
>   BUILD:   Doing 'make -j2' parallel build
>   Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs...
>   ... some more similar lines removed.
>
>   Makefile.config:1120: No suitable libLLVM found, disabling builtin clang and LLVM support.
>   Please install llvm-dev(el) (>= 3.9.0)
>
> However when I check llvm packages, I do have them installed on that machine:
>
>  # rpm -qa | grep llvm
>  llvm-libs-16.0.3-1.fc38.x86_64
>  llvm-16.0.3-1.fc38.x86_64
>  llvm-test-16.0.3-1.fc38.x86_64
>  llvm-static-16.0.3-1.fc38.x86_64
>  llvm-devel-16.0.3-1.fc38.x86_64
>
>  # rpm -qa | grep clang
>  clang-resource-filesystem-16.0.3-1.fc38.x86_64
>  clang-libs-16.0.3-1.fc38.x86_64
>  clang-tools-extra-16.0.3-1.fc38.x86_64
>  clang-16.0.3-1.fc38.x86_64
>  clang-devel-16.0.3-1.fc38.x86_64
>  git-clang-format-16.0.3-1.fc38.x86_64
> [root@f38 ~]#
>
> This shows up on s390x and x86_64 (my virtual machine).
> Any ideas have to fix this? Am I missing a package?
>
> Thanks.

Hmm.. I found when building in tools/perf I needed BUILD_BPF_SKEL=1.
The build output was put in
./util/bpf_skel/.tmp/feature/test-llvm.make.output. Testing with
clang/llvm 14 and 15, things were okay. Could you check the make
output file?

Thanks,
Ian

> --
> Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
> --
> Vorsitzender des Aufsichtsrats: Gregor Pillen
> Geschäftsführung: David Faller
> Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294