Re: [PATCH v3 bpf-next 04/14] samples: bpf: use own EXTRA_CFLAGS for clang commands

From: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Yonghong Song <yhs@fb.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <jakub.kicinski@netronome.com>,
	Jesper Dangaard Brouer <hawk@kernel.org>,
	john fastabend <john.fastabend@gmail.com>,
	open list <linux-kernel@vger.kernel.org>,
	Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
	clang-built-linux@googlegroups.com,
	sergei.shtylyov@cogentembedded.com
Subject: Re: [PATCH v3 bpf-next 04/14] samples: bpf: use own EXTRA_CFLAGS for clang commands
Date: Tue, 17 Sep 2019 01:01:18 +0300	[thread overview]
Message-ID: <20190916220117.GB4420@khorivan> (raw)
In-Reply-To: <CAEf4BzYJ5Q4rBHGET5z6nPBhh=8qAK7uuCK=Qnsh14FDH-24gA@mail.gmail.com>

On Mon, Sep 16, 2019 at 01:35:21PM -0700, Andrii Nakryiko wrote:
>On Mon, Sep 16, 2019 at 4:01 AM Ivan Khoronzhuk
><ivan.khoronzhuk@linaro.org> wrote:
>>
>> It can overlap with CFLAGS used for libraries built with gcc if
>> not now then in next patches. Correct it here for simplicity.
>>
>> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
>> ---
>
>With GCC BPF front-end recently added, we should probably generalize
>this to something like BPF_EXTRA_CFLAGS or something like that,
>eventually. But for now:
>
>Acked-by: Andrii Nakryiko <andriin@fb.com>

I can replace with BPF_EXTRA_CFLAGS in next v.

>
>>  samples/bpf/Makefile | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
>> index b59e77e2250e..8ecc5d0c2d5b 100644
>> --- a/samples/bpf/Makefile
>> +++ b/samples/bpf/Makefile
>> @@ -218,10 +218,10 @@ BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \
>>                           /bin/rm -f ./llvm_btf_verify.o)
>>
>>  ifneq ($(BTF_LLVM_PROBE),)
>> -       EXTRA_CFLAGS += -g
>> +       CLANG_EXTRA_CFLAGS += -g
>>  else
>>  ifneq ($(and $(BTF_LLC_PROBE),$(BTF_PAHOLE_PROBE),$(BTF_OBJCOPY_PROBE)),)
>> -       EXTRA_CFLAGS += -g
>> +       CLANG_EXTRA_CFLAGS += -g
>>         LLC_FLAGS += -mattr=dwarfris
>>         DWARF2BTF = y
>>  endif
>> @@ -280,8 +280,8 @@ $(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
>>  # useless for BPF samples.
>>  $(obj)/%.o: $(src)/%.c
>>         @echo "  CLANG-bpf " $@
>> -       $(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) -I$(obj) \
>> -               -I$(srctree)/tools/testing/selftests/bpf/ \
>> +       $(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(CLANG_EXTRA_CFLAGS) \
>> +               -I$(obj) -I$(srctree)/tools/testing/selftests/bpf/ \
>>                 -D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value -Wno-pointer-sign \
>>                 -D__TARGET_ARCH_$(SRCARCH) -Wno-compare-distinct-pointer-types \
>>                 -Wno-gnu-variable-sized-type-not-at-end \
>> --
>> 2.17.1
>>

-- 
Regards,
Ivan Khoronzhuk