perf version: Display availability of HAVE_DWARF_UNWIND_SUPPORT

Even though unwinding depends on either HAVE_DWARF_SUPPORT or
HAVE_LIBUNWIND, scripts testing unwinding can't just look for the
existence of either of those flags. This is because
NO_LIBDW_DWARF_UNWIND=1 can disable unwinding with libdw, but libdw will
still be linked leaving HAVE_DWARF_SUPPORT turned on. Presumably because
it is used for things other than unwinding, so I don't think this needs
to be fixed.

HAVE_DWARF_UNWIND_SUPPORT already takes the combination of all those
things into account, and is used to gate the built in tests like "Test
dwarf unwind", so add it to the feature list output so that it can be
used by the script tests too.

Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Spoorthy S <spoorts2@in.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/20240123163903.350306-2-james.clark@arm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/builtin-version.c b/tools/perf/builtin-version.c
index ac20c2b..529e9ce 100644 (file)
--- a/tools/perf/builtin-version.c
+++ b/tools/perf/builtin-version.c
@@ -82,6 +82,7 @@ static void library_status(void)
        STATUS(HAVE_LIBPFM, libpfm4);
        STATUS(HAVE_LIBTRACEEVENT, libtraceevent);
        STATUS(HAVE_BPF_SKEL, bpf_skeletons);
+       STATUS(HAVE_DWARF_UNWIND_SUPPORT, dwarf-unwind-support);
 }
 
 int cmd_version(int argc, const char **argv)