On Wed, 19 Feb 2020 10:38:45 -0800 Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote: > On Wed, Feb 19, 2020 at 10:29 AM Jesper Dangaard Brouer > <brouer@xxxxxxxxxx> wrote: > > > > On Wed, 19 Feb 2020 09:38:50 -0800 > > Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote: > > > > > On Wed, Feb 19, 2020 at 9:04 AM Jesper Dangaard Brouer > > > <brouer@xxxxxxxxxx> wrote: > > > > > > > > On Wed, 19 Feb 2020 08:41:27 -0800 > > > > Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > > > > > > > > On Wed, Feb 19, 2020 at 4:30 AM Jesper Dangaard Brouer > > > > > <brouer@xxxxxxxxxx> wrote: > > > > > > > > > > > > I'm willing to help out, such that we can do either version or feature > > > > > > detection, to either skip compiling specific test programs or at least > > > > > > give users a proper warning of they are using a too "old" LLVM version. > > > > > ... > > > > > > progs/test_core_reloc_bitfields_probed.c:47:13: error: use of unknown builtin '__builtin_preserve_field_info' [-Wimplicit-function-declaration] > > > > > > out->ub1 = BPF_CORE_READ_BITFIELD_PROBED(in, ub1); > > > > > > > > > > imo this is proper warning message already. > > > > > > > > This is an error, not a warning. The build breaks as the make process stops. > > > > > > > > > > Latest Clang was a requirement for building and running all selftests > > > for a long time now. There were few previous discussions on mailing > > > list about this and each time the conclusion was the same: latest > > > Clang is a requirement for BPF selftests. > > > > The latest Clang is 9.0.1, and it doesn't build with that. > > Latest as in "latest built from sources". When I download a specific kernel release, how can I know what LLVM git-hash or version I need (to use BPF-selftests)? Do you think it is reasonable to require end-users to compile their own bleeding edge version of LLVM, to use BPF-selftests? I do hope that some end-users of BPF-selftests will be CI-systems. That also implies that CI-system maintainers need to constantly do "latest built from sources" of LLVM git-tree to keep up. Is that a reasonable requirement when buying a CI-system in the cloud? -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
