[PATCH v8 1/7] perf config: Introduce default_config_section and default_config_item for default config key-value pairs

[Taeung Song]

When initializing default perf config values,
we currently use values of actual type(int, bool, char *, etc.).

For example,
If there isn't a user config value for 'annotate.use_offset'
config variable at ~/.perfconfig,
default value for it is 'true' bool type value in perf like below.

At ui/browsers/annoate.c

static struct annotate_browser_opt {
        bool hide_src_code,
             use_offset,
             jump_arrows,
             show_linenr,
             show_nr_jumps,
             show_total_period;
} annotate_browser__opts = {
        .use_offset      = true,
        .jump_arrows     = true,
};

But I suggest using 'struct default_config_section' and
'struct default_config_item' that can contain default config key-value pairs
in order to initialize default config values with them, in near future.

If we do, we could manage default perf config values at one spot (i.e. 
util/config.c)
with default config arrays and it could be easy and simple to modify
existing default config values or add default values for new config item.

Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Wang Nan <wangn...@huawei.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Masami Hiramatsu <mhira...@kernel.org>
Signed-off-by: Taeung Song <treeze.tae...@gmail.com>
---
 tools/perf/util/config.h | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
index 6f813d4..1fd8e4c 100644
--- a/tools/perf/util/config.h
+++ b/tools/perf/util/config.h
@@ -63,4 +63,33 @@ void perf_config__refresh(void);
        perf_config_sections__for_each_entry(&set->sections, section)           
\
        perf_config_items__for_each_entry(&section->items, item)
 
+enum perf_config_type {
+       CONFIG_TYPE_BOOL,
+       CONFIG_TYPE_INT,
+       CONFIG_TYPE_LONG,
+       CONFIG_TYPE_U64,
+       CONFIG_TYPE_FLOAT,
+       CONFIG_TYPE_DOUBLE,
+       CONFIG_TYPE_STRING
+};
+
+struct default_config_item {
+       const char *name;
+       union {
+               bool b;
+               int i;
+               u32 l;
+               u64 ll;
+               float f;
+               double d;
+               const char *s;
+       } value;
+       enum perf_config_type type;
+};
+
+struct default_config_section {
+       const char *name;
+       const struct default_config_item *items;
+};
+
 #endif /* __PERF_CONFIG_H */
-- 
2.7.4