On Mon, Mar 28, 2022 at 11:50 AM Jiri Olsa <olsajiri@xxxxxxxxx> wrote:
>
> On Mon, Mar 28, 2022 at 08:41:18AM -0700, Yonghong Song wrote:
> >
> >
> > On 3/28/22 1:37 AM, Jiri Olsa wrote:
> > > Arnaldo reported perf compilation fail with:
> > >
> > > $ make -k BUILD_BPF_SKEL=1 CORESIGHT=1 PYTHON=python3
> > > ...
> > > In file included from util/bpf_counter.c:28:
> > > /tmp/build/perf//util/bpf_skel/bperf_leader.skel.h: In function ‘bperf_leader_bpf__assert’:
> > > /tmp/build/perf//util/bpf_skel/bperf_leader.skel.h:351:51: error: unused parameter ‘s’ [-Werror=unused-parameter]
> > > 351 | bperf_leader_bpf__assert(struct bperf_leader_bpf *s)
> > > | ~~~~~~~~~~~~~~~~~~~~~~~~~^
> > > cc1: all warnings being treated as errors
> > >
> > > If there's nothing to generate in the new assert function,
> > > we will get unused 's' warn/error, adding 'unused' attribute to it.
> >
> > If there is nothing to generate, should we avoid generating
> > the assert function itself?
>
> good point, will check
we can use this function for some more assertions in the future, so
instead of trying to be smart about generating or not of this
function, I think unused attribute is a more robust solution.
>
> jirka
>
> >
> > >
> > > Cc: Delyan Kratunov <delyank@xxxxxx>
> > > Reported-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> > > Fixes: 08d4dba6ae77 ("bpftool: Bpf skeletons assert type sizes")
> > > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> > > ---
> > > tools/bpf/bpftool/gen.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
> > > index 7ba7ff55d2ea..91af2850b505 100644
> > > --- a/tools/bpf/bpftool/gen.c
> > > +++ b/tools/bpf/bpftool/gen.c
> > > @@ -477,7 +477,7 @@ static void codegen_asserts(struct bpf_object *obj, const char *obj_name)
> > > codegen("\
> > > \n\
> > > __attribute__((unused)) static void \n\
> > > - %1$s__assert(struct %1$s *s) \n\
> > > + %1$s__assert(struct %1$s *s __attribute__((unused))) \n\
> > > { \n\
> > > #ifdef __cplusplus \n\
> > > #define _Static_assert static_assert \n\
