Re: [PATCH 1/1] perf build: Gracefully fail the build if BUILD_BPF_SKEL=1 is specified and clang isn't available

[Namhyung Kim]

Hi Arnaldo,

On Tue, May 9, 2023 at 11:54 AM <arnaldo.melo@xxxxxxxxx> wrote:
>
> Namhyung,
>
>         The one you acked disabled the build and emitted a warning, but
> then that was when we were trying to have BUILD_BPF_SKEL=1 as default,
> this one is for the current situation, where we need to explicitely ask
> for those features by explicitely adding BUILD_BPF_SKEL=1 to the make
> command line, I think I can keep your Acked-by, right?

Sure thing!

Thanks,
Namhyung


> ---
>
> Build BPF skels require having a compiler able to generate BPF bytecode,
> and so far this is only possible with clang, so check for its
> availability and fail the build when the user explicitely ask for BPF
> skels to be built.
>
> Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>,
> Cc: Ian Rogers <irogers@xxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Song Liu <songliubraving@xxxxxxxx>
> Cc: Yang Jihong <yangjihong1@xxxxxxxxxx>,
> Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> ---
>  tools/perf/Makefile.config | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 4884520f954f4b2a..70268442f7eeca50 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -216,6 +216,12 @@ ifeq ($(call get-executable,$(BISON)),)
>    dummy := $(error Error: $(BISON) is missing on this system, please install it)
>  endif
>
> +ifeq ($(BUILD_BPF_SKEL),1)
> +  ifeq ($(call get-executable,$(CLANG)),)
> +    dummy := $(error $(CLANG) is missing on this system, please install it to be able to build with BUILD_BPF_SKEL=1)
> +  endif
> +endif
> +
>  ifneq ($(OUTPUT),)
>    ifeq ($(shell expr $(shell $(BISON) --version | grep bison | sed -e 's/.\+ \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 371), 1)
>      BISON_FILE_PREFIX_MAP := --file-prefix-map=$(OUTPUT)=
> --
> 2.39.2
>