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Date:   Sat, 7 Sep 2019 02:52:08 +0300
From:   Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
To:     Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc:     ast@kernel.org, daniel@iogearbox.net, yhs@fb.com,
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        john.fastabend@gmail.com, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, bpf@vger.kernel.org,
        clang-built-linux@googlegroups.com
Subject: Re: [PATCH bpf-next 2/8] samples: bpf: Makefile: remove target for
 native build
Message-ID: <20190906235207.GA3053@khorivan>
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On Fri, Sep 06, 2019 at 04:31:39PM -0700, Alexei Starovoitov wrote:
>On Thu, Sep 05, 2019 at 12:22:06AM +0300, Ivan Khoronzhuk wrote:
>> No need to set --target for native build, at least for arm, the
>> default target will be used anyway. In case of arm, for at least
>> clang 5 - 10 it causes error like:
>>
>> clang: warning: unknown platform, assuming -mfloat-abi=soft
>> LLVM ERROR: Unsupported calling convention
>> make[2]: *** [/home/root/snapshot/samples/bpf/Makefile:299:
>> /home/root/snapshot/samples/bpf/sockex1_kern.o] Error 1
>>
>> Only set to real triple helps: --target=arm-linux-gnueabihf
>> or just drop the target key to use default one. Decision to just
>> drop it and thus default target will be used (wich is native),
>> looks better.
>>
>> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
>> ---
>>  samples/bpf/Makefile | 2 --
>>  1 file changed, 2 deletions(-)
>>
>> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
>> index 61b7394b811e..a2953357927e 100644
>> --- a/samples/bpf/Makefile
>> +++ b/samples/bpf/Makefile
>> @@ -197,8 +197,6 @@ BTF_PAHOLE ?= pahole
>>  ifdef CROSS_COMPILE
>>  HOSTCC = $(CROSS_COMPILE)gcc
>>  CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
>> -else
>> -CLANG_ARCH_ARGS = -target $(ARCH)
>>  endif
>
>I don't follow here.
>Didn't you introduce this bug in patch 1 and now fixing it in patch 2?
>

It looks like but that's not true.
Previous patch adds target only for cross compiling,
before the patch the target was used for both, cross compiling and w/o cc.

This patch removes target only for native build (it's not cross compiling).

By fact, it's two separate significant changes.

-- 
Regards,
Ivan Khoronzhuk