[PATCH v5 3/3] perf config: Allow creating empty config set for config file autogeneration

[Taeung Song]

When there isn't a config file (e.g. ~/.perfconfig)
or it has nothing, the config set wasn't created.
If the config set not exists, a config file can't be autogenerated.

So allow creating a empty config set in the above case,
then we can support the config file autogeneration.

Before:

  $ rm -f ~/.perfconfig
  $ perf config --user report.children=false

  $ cat ~/.perfconfig
  cat: /root/.perfconfig: No such file or directory

But I think it should work even if there isn't a config file.

After:

  $ rm -f ~/.perfconfig
  $ perf config --user report.children=false

  $ cat ~/.perfconfig
  # this file is auto-generated.
  [report]
      children = false

NOTE:
As a result, if perf_config_set__init() is failed,
it seems that the config set isn't freed. But it isn't a problem.
Because the config set  will be freed by perf_config_set__delete()
at the end of cmd_config().

Cc: Jiri Olsa <jo...@kernel.org>
Cc: Namhyung Kim <namhy...@kernel.org>
Signed-off-by: Taeung Song <treeze.tae...@gmail.com>
---
 tools/perf/util/config.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index bc75596..d2b6983 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -700,10 +700,7 @@ struct perf_config_set *perf_config_set__new(void)
 
        if (set) {
                INIT_LIST_HEAD(&set->sections);
-               if (perf_config_set__init(set) < 0) {
-                       perf_config_set__delete(set);
-                       set = NULL;
-               }
+               perf_config_set__init(set);
        }
 
        return set;
-- 
2.7.4