Messages in this thread | | | From | Ian Rogers <> | Date | Wed, 3 Apr 2024 15:01:43 -0700 | Subject | Re: [PATCH 1/1] perf annotate: Initialize 'arch' variable not to trip some -Werror=maybe-uninitialized |
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On Wed, Apr 3, 2024 at 2:03 PM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > On Wed, Apr 03, 2024 at 09:01:56AM -0700, Ian Rogers wrote: > > On Wed, Apr 3, 2024 at 8:16 AM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > > > > > In some older distros the build is failing due to > > > -Werror=maybe-uninitialized, in this case we know that this isn't the > > > case because 'arch' gets initialized by evsel__get_arch(), so just init > > > it to NULL to silence those cases. > > > > > > E.g.: > > > > > > 32 17.12 opensuse:15.5 : FAIL gcc version 7.5.0 (SUSE Linux) > > > util/annotate.c: In function 'hist_entry__get_data_type': > > > util/annotate.c:2269:15: error: 'arch' may be used uninitialized in this function [-Werror=maybe-uninitialized] > > > struct arch *arch; > > > ^~~~ > > > cc1: all warnings being treated as errors > > > > > > 43 7.30 ubuntu:18.04-x-powerpc64el : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04) > > > util/annotate.c: In function 'hist_entry__get_data_type': > > > util/annotate.c:2351:36: error: 'arch' may be used uninitialized in this function [-Werror=maybe-uninitialized] > > > if (map__dso(ms->map)->kernel && arch__is(arch, "x86") && > > > ^~~~~~~~~~~~~~~~~~~~~ > > > cc1: all warnings being treated as errors > > > > > > Cc: Adrian Hunter <adrian.hunter@intel.com> > > > Cc: Ian Rogers <irogers@google.com> > > > Cc: Jiri Olsa <jolsa@kernel.org> > > > Cc: Namhyung Kim <namhyung@kernel.org> > > > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> > > > > This looks fine but I couldn't line up the errors with code in the > > tree. I was curious why the "maybe-uninitialized" was failing. Perhaps > > evsel__get_arch should set the out argument to NULL when an error > > occurs. This fix is also good but may potentially need repeating for > > other evsel__get_arch cases, so a fix in evsel__get_arch may be > > preferable. > > > > Reviewed-by: Ian Rogers <irogers@google.com> > > Yeah, your suggestion is better and I just tested, satisfies the > compilers that were emitting this warning. > > I stamped a: > > Suggested-by: Ian Rogers <irogers@google.com> > > and kept your Reviewed-by, ok?
Sure :-)
Thanks, Ian
> - Arnaldo
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