Andrii Nakryiko andrii.nakryiko@gmail.com writes:
On Mon, Jan 20, 2020 at 5:08 AM Toke Høiland-Jørgensen toke@redhat.com wrote:
We are currently being somewhat inconsistent with the libbpf include paths, which makes it difficult to move files from the kernel into an external libbpf-using project without adjusting include paths.
Having the bpf/ subdir of $INCLUDEDIR in the include path has never been a requirement for building against libbpf before, and indeed the libbpf pkg-config file doesn't include it. So let's make all libbpf includes across the kernel tree use the bpf/ prefix in their includes. Since bpftool skeleton generation emits code with a libbpf include, this also ensures that those can be used in existing external projects using the regular pkg-config include path.
This turns out to be a somewhat invasive change in the number of files touched; however, the actual changes to files are fairly trivial (most of them are simply made with 'sed'). The series is split to make the change for one tool subdir at a time, while trying not to break the build along the way. It is structured like this:
Patch 1-3: Trivial fixes to Makefiles for issues I discovered while changing the include paths.
Patch 4-8: Change the include directives to use the bpf/ prefix, and updates Makefiles to make sure tools/lib/ is part of the include path, but without removing tools/lib/bpf
Patch 9-11: Remove tools/lib/bpf from include paths to make sure we don't inadvertently re-introduce includes without the bpf/ prefix.
Changelog:
v5:
- Combine the libbpf build rules in selftests Makefile (using Andrii's suggestion for a make rule).
- Re-use self-tests libbpf build for runqslower (new patch 10)
- Formatting fixes
v4:
- Move runqslower error on missing BTF into make rule
- Make sure we don't always force a rebuild selftests
- Rebase on latest bpf-next (dropping patch 11)
v3:
- Don't add the kernel build dir to the runqslower Makefile, pass it in from selftests instead.
- Use libbpf's 'make install_headers' in selftests instead of trying to generate bpf_helper_defs.h in-place (to also work on read-only filesystems).
- Use a scratch builddir for both libbpf and bpftool when building in selftests.
- Revert bpf_helpers.h to quoted include instead of angled include with a bpf/ prefix.
- Fix a few style nits from Andrii
v2:
- Do a full cleanup of libbpf includes instead of just changing the bpf_helper_defs.h include.
Looks good, it's a clear improvement on what we had before, thanks!
It doesn't re-build bpftool when bpftool sources changes, but I think it was like that even before, so no need to block on that. Would be nice to have a follow up fixing that, though. $(wildcard $(BPFTOOL_DIR)/*.[ch] $(BPFTOOL_DIR)/Makefile) should do it, same as for libbpf.
Yeah, I did realise there was some potential for improvement for bpftool as well, but I got enough of Makefiles for now :)
I'll see if I can't circle back to this at some point...
So, for the series:
Acked-by: Andrii Nakryiko andriin@fb.com Tested-by: Andrii Nakryiko andriin@fb.com
Thanks!
-Toke