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Date:   Mon, 19 Dec 2022 11:59:38 +0800
From:   Leo Yan <leo.yan@linaro.org>
To:     Changbin Du <changbin.du@gmail.com>
Cc:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Quentin Monnet <quentin@isovalent.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Shuah Khan <shuah@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Stanislav Fomichev <sdf@google.com>,
        Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Mykola Lysenko <mykolal@fb.com>,
        linux-perf-users@vger.kernel.org, linux-kselftest@vger.kernel.org
Subject: Re: [PATCH v3 2/2] bpf: makefiles: do not generate empty vmlinux.h
Message-ID: <Y5/hqqIwJIjdBSRh@leoy-yangtze.lan>
References: <20221217223509.88254-1-changbin.du@gmail.com>
 <20221217223509.88254-3-changbin.du@gmail.com>
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On Sun, Dec 18, 2022 at 06:35:09AM +0800, Changbin Du wrote:
> Remove the empty vmlinux.h if bpftool failed to dump btf info.
> The empty vmlinux.h can hide real error when reading output
> of make.
> 
> This is done by adding .DELETE_ON_ERROR special target in related
> makefiles.

We need to handle the same case for perf building, its makefile
linux/tools/perf/Makefile.perf also uses bpftool to generate
vmlinux.h, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf/Makefile.perf#n1067

Please consider to use a separate patch to add the same change in
Makefile.perf?

Thanks,
Leo

> Signed-off-by: Changbin Du <changbin.du@gmail.com>
> ---
>  tools/bpf/bpftool/Makefile           | 3 +++
>  tools/testing/selftests/bpf/Makefile | 3 +++
>  2 files changed, 6 insertions(+)
> 
> diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
> index 787b857d3fb5..313fd1b09189 100644
> --- a/tools/bpf/bpftool/Makefile
> +++ b/tools/bpf/bpftool/Makefile
> @@ -289,3 +289,6 @@ FORCE:
>  .PHONY: all FORCE bootstrap clean install-bin install uninstall
>  .PHONY: doc doc-clean doc-install doc-uninstall
>  .DEFAULT_GOAL := all
> +
> +# Delete partially updated (corrupted) files on error
> +.DELETE_ON_ERROR:
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index c22c43bbee19..205e8c3c346a 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -626,3 +626,6 @@ EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(SCRATCH_DIR) $(HOST_SCRATCH_DIR)	\
>  			       liburandom_read.so)
>  
>  .PHONY: docs docs-clean
> +
> +# Delete partially updated (corrupted) files on error
> +.DELETE_ON_ERROR:
> -- 
> 2.37.2
>