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Message-ID: <a5d419e4-f2ea-27f6-9259-a7b6486ab616@isovalent.com>
Date:   Fri, 23 Jun 2023 09:51:29 +0100
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Subject: Re: [PATCH] bpf: Replace deprecated -target with --target= for Clang
Content-Language: en-GB
To:     Fangrui Song <maskray@google.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        John Fastabend <john.fastabend@gmail.com>, bpf@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, llvm@lists.linux.dev
References: <20230623020908.1410959-1-maskray@google.com>
From:   Quentin Monnet <quentin@isovalent.com>
In-Reply-To: <20230623020908.1410959-1-maskray@google.com>
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2023-06-23 02:09 UTC+0000 ~ Fangrui Song <maskray@google.com>
> -target has been deprecated since Clang 3.4 in 2013. Use the preferred
> --target=bpf form instead. This matches how we use --target= in
> scripts/Makefile.clang.

This seems to be the relevant commit, for reference:

https://github.com/llvm/llvm-project/commit/274b6f0c87a6a1798de0a68135afc7f95def6277

> 
> Signed-off-by: Fangrui Song <maskray@google.com>
> ---
>  Documentation/bpf/bpf_devel_QA.rst              | 10 +++++-----
>  Documentation/bpf/btf.rst                       |  4 ++--
>  Documentation/bpf/llvm_reloc.rst                |  6 +++---
>  drivers/hid/bpf/entrypoints/Makefile            |  2 +-
>  kernel/bpf/preload/iterators/Makefile           |  2 +-
>  samples/bpf/Makefile                            |  6 +++---
>  samples/bpf/gnu/stubs.h                         |  3 ++-
>  samples/bpf/test_lwt_bpf.sh                     |  2 +-
>  samples/hid/Makefile                            |  6 +++---
>  tools/bpf/bpftool/Documentation/bpftool-gen.rst |  4 ++--
>  tools/bpf/bpftool/Makefile                      |  2 +-
>  tools/bpf/runqslower/Makefile                   |  2 +-
>  tools/build/feature/Makefile                    |  2 +-
>  tools/perf/Documentation/perf-config.txt        |  2 +-
>  tools/perf/Makefile.perf                        |  4 ++--
>  tools/perf/util/llvm-utils.c                    |  4 ++--
>  tools/testing/selftests/bpf/Makefile            |  6 +++---
>  tools/testing/selftests/bpf/gnu/stubs.h         |  3 ++-
>  tools/testing/selftests/hid/Makefile            |  6 +++---
>  tools/testing/selftests/net/Makefile            |  4 ++--
>  tools/testing/selftests/tc-testing/Makefile     |  2 +-
>  21 files changed, 42 insertions(+), 40 deletions(-)
> 

> diff --git a/samples/bpf/gnu/stubs.h b/samples/bpf/gnu/stubs.h
> index 719225b16626..cc37155fbfa5 100644
> --- a/samples/bpf/gnu/stubs.h
> +++ b/samples/bpf/gnu/stubs.h
> @@ -1 +1,2 @@
> -/* dummy .h to trick /usr/include/features.h to work with 'clang -target bpf' */
> +/* SPDX-License-Identifier: GPL-2.0 */

Are these necessary, seeing that the files only contain this single-line
comment?

> +/* dummy .h to trick /usr/include/features.h to work with 'clang --target=bpf' */

Other than this, the change looks good, thanks. Although it should
probably target bpf-next rather than bpf?

Acked-by: Quentin Monnet <quentin@isovalent.com>