perf evlist: Factor out asprintf routine to build a tracepoint pid filter

Will be used to append such lists to existing filters.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-798vlyqfqw938ehoe8etivx1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index b4c43ac..c1b4608 100644 (file)
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1053,6 +1053,9 @@ int perf_evlist__set_tp_filter(struct evlist *evlist, const char *filter)
        struct evsel *evsel;
        int err = 0;
 
+       if (filter == NULL)
+               return -1;
+
        evlist__for_each_entry(evlist, evsel) {
                if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
                        continue;
@@ -1065,16 +1068,15 @@ int perf_evlist__set_tp_filter(struct evlist *evlist, const char *filter)
        return err;
 }
 
-int perf_evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
+static char *asprintf__tp_filter_pids(size_t npids, pid_t *pids)
 {
        char *filter;
-       int ret = -1;
        size_t i;
 
        for (i = 0; i < npids; ++i) {
                if (i == 0) {
                        if (asprintf(&filter, "common_pid != %d", pids[i]) < 0)
-                               return -1;
+                               return NULL;
                } else {
                        char *tmp;
 
@@ -1086,9 +1088,18 @@ int perf_evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *
                }
        }
 
-       ret = perf_evlist__set_tp_filter(evlist, filter);
+       return filter;
 out_free:
        free(filter);
+       return NULL;
+}
+
+int perf_evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
+{
+       char *filter = asprintf__tp_filter_pids(npids, pids);
+       int ret = perf_evlist__set_tp_filter(evlist, filter);
+
+       free(filter);
        return ret;
 }