Re: make samples/bpf/ using gcc instead of clang/llvm

[Alexei Starovoitov]

On Tue, Jan 26, 2016 at 09:51:54PM -0800, Joel Fernandes wrote:
> Hi Brendan, Alexei,
> 
> I noticed your patch fixing the $subject issue.
> 
> https://patchwork.ozlabs.org/patch/471118/
> 
> However, I still see make samples/bpf/ using gcc instead of clang.
> 
> Here's a verbose kbuild output of make samples/bpf/. My kernel version
> is 4.4. It looks to me like Kbuild is ignoring the Makefile in
> samples/bpf/. Let me know if you spot anything of the ordinary?
> Thanks.
> 
>  make  KBUILD_VERBOSE=1 samples/bpf/
> [..]
> make KBUILD_MODULES=1 \
>     -f /home/joel/data/repo/linux-4.4/scripts/Makefile.build obj=samples/bpf
> (cat /dev/null; ) > samples/bpf/modules.order
>   gcc -Wp,-MD,samples/bpf/.test_verifier.o.d -Isamples/bpf -Wall
> -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer
> -std=gnu89  -I/home/joel/data/repo/linux-4.4/./usr/include
> -I./usr/include -c -o samples/bpf/test_verifier.o
> /home/joel/data/repo/linux-4.4/samples/bpf/test_verifier.c
> /home/joel/data/repo/linux-4.4/samples/bpf/test_verifier.c:12:23:
> fatal error: linux/bpf.h: No such file or directory
>  #include <linux/bpf.h>
>                        ^
> compilation terminated.

test_verifier.c should be built with gcc.
*_kern.c are built with clang.
In this case likely 'make headers_install' is missing.