perf session: Destructors should accept NULL

And do nothing, just like free(), to avoid having to test it in callers,
usually in error paths.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-dyuupcj0hnoyt96vma8b3anv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

4 files changed, 5 insertions, 7 deletions

diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
index d75bded21fe0..2cbec658be90 100644
--- a/tools/perf/builtin-buildid-cache.c
+++ b/tools/perf/builtin-buildid-cache.c
@@ -419,8 +419,7 @@ int cmd_buildid_cache(int argc, const char **argv,
                 pr_warning("Couldn't add %s\n", kcore_filename);
 
 out:
-        if (session)
-                perf_session__delete(session);
+        perf_session__delete(session);
 
         return ret;
 }
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 8b6735f35179..eac0b1100b8f 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -756,9 +756,7 @@ static int __cmd_diff(void)
 
  out_delete:
         data__for_each_file(i, d) {
-                if (d->session)
-                        perf_session__delete(d->session);
-
+                perf_session__delete(d->session);
                 data__free(d);
         }
 
diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index ad46e91abec5..8f8f90e2b993 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -1426,8 +1426,7 @@ static int kvm_events_live(struct perf_kvm_stat *kvm,
         err = kvm_events_live_report(kvm);
 
 out:
-        if (kvm->session)
-                perf_session__delete(kvm->session);
+        perf_session__delete(kvm->session);
         kvm->session = NULL;
         perf_evlist__delete(kvm->evlist);
 
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index dfedf097b9b1..43be0c5a6a26 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -178,6 +178,8 @@ static void perf_session__delete_threads(struct perf_session *session)
 
 void perf_session__delete(struct perf_session *session)
 {
+        if (session == NULL)
+                return;
         auxtrace__free(session);
         auxtrace_index__free(&session->auxtrace_index);
         perf_session__destroy_kernel_maps(session);