Re: [PATCH] tools: feature/test-libperl.c: Sync PERL_EMBED_CCOPTS with perf

From: Nick Desaulniers
Date: Thu Mar 10 2022 - 15:59:45 EST


On Wed, Mar 9, 2022 at 10:19 PM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
>
> When trying to build perf with a LLVM/Clang toolchain people see errors
> when testing for libperl feature.
>
> Jiri reports:
>
> > I'm getting some other lto related error:
> >
> > $ cat test-libperl.make.output
> > clang-13: error: optimization flag '-ffat-lto-objects' is not supported [-Werror,-Wignored-optimization-argument]
> >
>
> The reason is PERL_EMBED_CCOPTS is defined in two places:
>
> tools/build/feature/Makefile
> tools/perf/Makefile.config
>
> As an result FLAGS_PERL_EMBED is set differently.

s/an/a/

>
> For building perf '-ffat-lto-objects' is filtered-out:
>
> $ git grep ffat-lto-objects tools/perf/
> tools/perf/Makefile.config: PERL_EMBED_CCOPTS := $(filter-out -flto=auto -ffat-lto-objects, $(PERL_EMBED_CCOPTS))
>
> Sync PERL_EMBED_CCOPTS in tools/build/feature/Makefile to fix this.
>
> For a minimal fix for Linux v5.17 this here was preferred by Arnaldo.
>
> Link: https://marc.info/?t=164646683300002&r=1&w=2

Hey Sedat, we prefer lore links now to external mirrors!

Link: https://lore.kernel.org/lkml/CA+icZUWHd4VTKNwBtuxt9-fHoiYV+Q7tQ809Cn83k8sbQ_uNHw@xxxxxxxxxxxxxx/

> Reported-by: Jiri Olsa <olsajiri@xxxxxxxxx>
> Reported-by: Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx>
> Tested-by: Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx>
> Suggested-by: Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx>
> Signed-off-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>

Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

> ---
> tools/build/feature/Makefile | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
> index 1480910c792e..869073cf8449 100644
> --- a/tools/build/feature/Makefile
> +++ b/tools/build/feature/Makefile
> @@ -218,6 +218,7 @@ PERL_EMBED_LDOPTS = $(shell perl -MExtUtils::Embed -e ldopts 2>/dev/null)
> PERL_EMBED_LDFLAGS = $(call strip-libs,$(PERL_EMBED_LDOPTS))
> PERL_EMBED_LIBADD = $(call grep-libs,$(PERL_EMBED_LDOPTS))
> PERL_EMBED_CCOPTS = `perl -MExtUtils::Embed -e ccopts 2>/dev/null`
> +PERL_EMBED_CCOPTS := $(filter-out -ffat-lto-objects, $(PERL_EMBED_CCOPTS))
> FLAGS_PERL_EMBED=$(PERL_EMBED_CCOPTS) $(PERL_EMBED_LDOPTS)
>
> $(OUTPUT)test-libperl.bin:
> --
> 2.35.1
>


--
Thanks,
~Nick Desaulniers