compilation of minimal failing because kernel header path not in includes about libbpf-bootstrap HOT 4 CLOSED

Another observation: clang does seem to want to search that arch-specific dir when not using -target bpf:

$ clang -v -g -O2  -D__TARGET_ARCH_x86 -I.output -c minimal.bpf.c -o .output/minimal.bpf.o
Ubuntu clang version 11.0.0-2
...
#include "..." search starts here:
#include <...> search starts here:
 .output
 /usr/local/include
 /usr/lib/llvm-11/lib/clang/11.0.0/include
 /usr/include/x86_64-linux-gnu
 /usr/include

from libbpf-bootstrap.

Oh, I think this is how we deal with it in kernel selftests: https://github.com/torvalds/linux/blob/master/tools/testing/selftests/bpf/Makefile#L215-L224

This seems to be due to using -target bpf, so for some systems not all the necessary include paths used... You are right that just using "vmlinux.h" would be enough, but that puts a requirement for kernel BTF on the system, and my goal was to have something to use even without kernel built with BTF...

Do you mind trying the get_sys_includes trick and confirming if that works? We can "backport" it here. Not that it's simple and obvious, but should just work.

from libbpf-bootstrap.

It works indeed. Would you like a patch?

from libbpf-bootstrap.

that would be great, thanks. Please also include a comment explaining why we need that.

from libbpf-bootstrap.