Re: [PATCH] perf tools: Fix build failture on perl script context

[Namhyung Kim <namhyung@kernel.org>]

Hi Arnaldo,

On Tue, Aug 02, 2016 at 10:29:22AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Tue, Aug 02, 2016 at 11:43:17AM +0900, Namhyung Kim escreveu:
> > On my Archlinux machine, perf faild to build like below:
> > 
> >     CC       scripts/perl/Perf-Trace-Util/Context.o
> >   In file included from /usr/lib/perl5/core/perl/CORE/perl.h:3905:0,
> >                    from Context.xs:23:
> >   /usr/lib/perl5/core/perl/CORE/inline.h: In function :
> >   /usr/lib/perl5/core/perl/CORE/cop.h:612:13: warning: declaration of 'av'
> >                                   shadows a previous local [-Werror-shadow]
> >              AV *av =3D GvAV(PL_defgv);
> >                  ^
> >   /usr/lib/perl5/core/perl/CORE/inline.h:526:5: note: in expansion of
> >                                   macro 'CX_POP_SAVEARRAY'
> >          CX_POP_SAVEARRAY(cx);
> >          ^~~~~~~~~~~~~~~~
> >   In file included from /usr/lib/perl5/core/perl/CORE/perl.h:5853:0,
> >                    from Context.xs:23:
> >   /usr/lib/perl5/core/perl/CORE/inline.h:518:9: note:
> >                                   shadowed declaration is here
> >          AV *av;
> >              ^~
> 
> But you forgot to describe _what_ you did to "fix" the problem besides
> breaking down a long line, i.e. adding -Wno-shadow, is that what we
> want? To ignore such warnings?
> 
> Some explanation in the changelog as to why that is the wise solution
> would help a lot :-\

Oops, sorry.

What I did to fix is adding '-Wno-shadow' as the error message said
it's the cause of the failure.  Since it's from the perl (not perf)
code base, we don't have the control so I just wanted to ignore the
warning when compiling perl scripting code.

Is it ok for you?

Thanks,
Namhyung


> > 
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > ---
> >  tools/perf/scripts/perl/Perf-Trace-Util/Build | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/tools/perf/scripts/perl/Perf-Trace-Util/Build b/tools/perf/scripts/perl/Perf-Trace-Util/Build
> > index 928e110179cb..34faecf774ae 100644
> > --- a/tools/perf/scripts/perl/Perf-Trace-Util/Build
> > +++ b/tools/perf/scripts/perl/Perf-Trace-Util/Build
> > @@ -1,3 +1,5 @@
> >  libperf-y += Context.o
> >  
> > -CFLAGS_Context.o += $(PERL_EMBED_CCOPTS) -Wno-redundant-decls -Wno-strict-prototypes -Wno-unused-parameter -Wno-nested-externs -Wno-undef -Wno-switch-default
> > +CFLAGS_Context.o += $(PERL_EMBED_CCOPTS) -Wno-redundant-decls -Wno-strict-prototypes
> > +CFLAGS_Context.o += -Wno-unused-parameter -Wno-nested-externs -Wno-undef
> > +CFLAGS_Context.o += -Wno-switch-default -Wno-shadow
> > -- 
> > 2.9.2