Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20190916105433.11404-1-ivan.khoronzhuk@linaro.org> <20190916105433.11404-2-ivan.khoronzhuk@linaro.org>
In-Reply-To: <20190916105433.11404-2-ivan.khoronzhuk@linaro.org>
From:   Andrii Nakryiko <andrii.nakryiko@gmail.com>
Date:   Mon, 16 Sep 2019 13:13:23 -0700
Message-ID: <CAEf4BzZVTjCybmDgM0VBzv_L-LHtF8LcDyyKSWJm0ZA4jtJKcw@mail.gmail.com>
Subject: Re: [PATCH v3 bpf-next 01/14] samples: bpf: makefile: fix HDR_PROBE "echo"
To:     Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
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
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, Sep 16, 2019 at 3:59 AM Ivan Khoronzhuk
<ivan.khoronzhuk@linaro.org> wrote:
>
> echo should be replaced with echo -e to handle '\n' correctly, but
> instead, replace it with printf as some systems can't handle echo -e.
>
> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
> ---
>  samples/bpf/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> index 1d9be26b4edd..f50ca852c2a8 100644
> --- a/samples/bpf/Makefile
> +++ b/samples/bpf/Makefile
> @@ -201,7 +201,7 @@ endif
>
>  # Don't evaluate probes and warnings if we need to run make recursively
>  ifneq ($(src),)
> -HDR_PROBE := $(shell echo "\#include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
> +HDR_PROBE := $(shell printf "\#include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \

printf change is fine, but I'm confused about \# at the beginning of
the string. Not sure what was the intent, but it seems like it should
work with just #include at the beginning.

>         $(HOSTCC) $(KBUILD_HOSTCFLAGS) -x c - -o /dev/null 2>/dev/null && \
>         echo okay)
>
> --
> 2.17.1
>