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From:   Andrii Nakryiko <andrii.nakryiko@gmail.com>
Date:   Wed, 30 Nov 2022 16:42:09 -0800
Message-ID: <CAEf4BzZ8z9yKwkbQthaNPR9HJDqq77EJwHaEqqwQ3qYjKWTRAQ@mail.gmail.com>
Subject: Re: [PATCH] Improved usability of the Makefile in libbpf
To:     Xin Liu <liuxin350@huawei.com>
Cc:     andrii@kernel.org, ast@kernel.org, daniel@iogearbox.net,
        martin.lau@linux.dev, song@kernel.org, yhs@fb.com,
        john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
        haoluo@google.com, jolsa@kernel.org, bpf@vger.kernel.org,
        linux-kernel@vger.kernel.org, yanan@huawei.com,
        wuchangye@huawei.com, xiesongyang@huawei.com,
        kongweibin2@huawei.com, zhangmingyi5@huawei.com
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On Mon, Nov 28, 2022 at 11:42 PM Xin Liu <liuxin350@huawei.com> wrote:
>
> Current libbpf Makefile does not contain the help command, which
> is inconvenient to use. A help command is provided to list the
> commands supported by libbpf make and the functions of the commands.
>
> Signed-off-by: Xin Liu <liuxin350@huawei.com>
> ---
>  tools/lib/bpf/Makefile | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
>
> diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
> index 4c904ef0b47e..c86e05df4711 100644
> --- a/tools/lib/bpf/Makefile
> +++ b/tools/lib/bpf/Makefile
> @@ -286,3 +286,37 @@ tags:
>
>  # Delete partially updated (corrupted) files on error
>  .DELETE_ON_ERROR:
> +
> +help:
> +       @echo 'Default targets:'
> +       @echo '  all               - Run all_cmd'
> +       @echo '  all_cmd           - Build library and pkgconfig, check abi and version info'
> +       @echo ''
> +       @echo 'Cleaning targets:'
> +       @echo '  clean             - Remove all generated files'
> +       @echo ''
> +       @echo 'Build targets:'
> +       @echo '  libbpf.so         - Build the dynamic library'
> +       @echo '  libbpf.a          - Build the static library'
> +       @echo '  libbpf.pc         - Build the pkgconfig file'
> +       @echo ''
> +       @echo 'Install targets:'
> +       @echo '  install           - Install all headers, library and pkgconfig file to'
> +       @echo '                      DESTDIR(default: /) with prefix(default: /usr/local)'
> +       @echo '  install_lib       - Install only library'
> +       @echo '  install_headers   - Install only headers'
> +       @echo '  install_pkgconfig - Install only pkgconfig file'
> +       @echo ''
> +       @echo 'Other generic targets:'
> +       @echo '  cscope            - Generate cscope index'
> +       @echo '  tags              - Generate tags file for editors'
> +       @echo '  check             - Check abi and version info'
> +       @echo '  check_abi         - Check versioned symbols'
> +       @echo '  check_version     - Check whether the libbpf version defined in libbpf_version.h'
> +       @echo '                      is the same as that defined in libbpf.map'
> +       @echo ''
> +       @echo '  make V=0|1             [targets] 0 => quiet build (default), 1 => verbose build'
> +       @echo '  make DESTDIR=/root     [install targets] use DESTDIR for installing'
> +       @echo '                                           into a different root directory'
> +       @echo '  make prefix=/path      [install targets] use prefix for installing'
> +       @echo '                                           into a user defined prefix path'


I'm a bit hesitant about adding all this. Most of those targets are
not intended to be used directly, only "all", "clean", and "install"
are supposed to be used by end-users (maybe also "install_headers").
And those seems to be pretty typical and straightforward targets.

I actually didn't even know about `make help`, but I checked perf's
`make help` and it's way more succinct, let's try modeling it here?

Also, please use [PATCH bpf-next] (with v2 in between them) for next
submission to point that this is meant for bpf-next tree.


> --
> 2.33.0
>