On Tue, Oct 22, 2024 at 04:18:15PM -0700, Andrii Nakryiko wrote:
> On Tue, Oct 22, 2024 at 10:24 AM Eder Zulian <ezulian@xxxxxxxxxx> wrote:
> >
> > Initialize the pointer 'o' in options__order to NULL to prevent a
> > compiler warning/error which is observed when compiling with the '-Og'
> > option, but is not emitted by the compiler with the current default
> > compilation options.
> >
> > For example, when compiling libsubcmd with
> >
> > $ make "EXTRA_CFLAGS=-Og" -C tools/lib/subcmd/ clean all
> >
> > Clang version 17.0.6 and GCC 13.3.1 fail to compile parse-options.c due
> > to following error:
> >
> > parse-options.c: In function ‘options__order’:
> > parse-options.c:832:9: error: ‘o’ may be used uninitialized [-Werror=maybe-uninitialized]
> > 832 | memcpy(&ordered[nr_opts], o, sizeof(*o));
> > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > parse-options.c:810:30: note: ‘o’ was declared here
> > 810 | const struct option *o, *p = opts;
> > | ^
> > cc1: all warnings being treated as errors
> >
> > Signed-off-by: Eder Zulian <ezulian@xxxxxxxxxx>
> > ---
> > tools/lib/subcmd/parse-options.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
>
> First two patches look good, we can take them through bpf-next. What
> do we do with this one? Arnaldo, would you like us to take it through
> bpf-next as well (if yes, please give your ack), or you'd like to take
Yes, please take it thru bpf-next
Acked-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
- Arnaldo
> it through your tree?
> > diff --git a/tools/lib/subcmd/parse-options.c b/tools/lib/subcmd/parse-options.c
> > index eb896d30545b..555d617c1f50 100644
> > --- a/tools/lib/subcmd/parse-options.c
> > +++ b/tools/lib/subcmd/parse-options.c
> > @@ -807,7 +807,7 @@ static int option__cmp(const void *va, const void *vb)
> > static struct option *options__order(const struct option *opts)
> > {
> > int nr_opts = 0, nr_group = 0, nr_parent = 0, len;
> > - const struct option *o, *p = opts;
> > + const struct option *o = NULL, *p = opts;
> > struct option *opt, *ordered = NULL, *group;
> >
> > /* flatten the options that have parents */
> > --
> > 2.46.2
