[PATCH v6 4/4] perf config: Initialize perf_config_set with all default configs

[Taeung Song]

To avoid duplicated config variables and
use perf_config_set classifying between standard
perf config variables and unknown or new config
variables other than them, initialize perf_config_set
with all default configs.

And this will be needed when showing all configs with
default value or checking correct type of a config
variable in the near future.

Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
---
 tools/perf/builtin-config.c | 11 +++++++----
 tools/perf/util/config.c    | 33 ++++++++++++++++++++++++++++++---
 tools/perf/util/config.h    |  7 +++++++
 3 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index 1133224..66a269e 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -35,23 +35,26 @@ static struct option config_options[] = {
 
 static int show_config(struct perf_config_set *set)
 {
+	bool has_value = false;
 	struct perf_config_section *section;
 	struct perf_config_item *item;
 	struct list_head *sections = &set->sections;
 
-	if (list_empty(sections))
-		return -1;
-
 	list_for_each_entry(section, sections, node) {
 		list_for_each_entry(item, &section->items, node) {
 			char *value = item->value;
 
-			if (value)
+			if (value) {
 				printf("%s.%s=%s\n", section->name,
 				       item->name, value);
+				has_value = true;
+			}
 		}
 	}
 
+	if (!has_value)
+		return -1;
+
 	return 0;
 }
 
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index f937124..1855560 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -663,6 +663,7 @@ static struct perf_config_section *add_section(struct list_head *sections,
 	if (!section)
 		return NULL;
 
+	section->is_custom = true;
 	INIT_LIST_HEAD(&section->items);
 	section->name = strdup(section_name);
 	if (!section->name) {
@@ -683,6 +684,7 @@ static struct perf_config_item *add_config_item(struct perf_config_section *sect
 	if (!item)
 		return NULL;
 
+	item->is_custom = true;
 	item->name = strdup(name);
 	if (!item->name) {
 		pr_debug("%s: strdup failed\n", __func__);
@@ -751,12 +753,35 @@ out_free:
 	return -1;
 }
 
+static struct perf_config_set *perf_config_set__init(struct perf_config_set *set)
+{
+	int i, j;
+	struct perf_config_section *section;
+	struct perf_config_item *items;
+	struct list_head *sections = &set->sections;
+
+	INIT_LIST_HEAD(&set->sections);
+
+	for (i = 0; i != CONFIG_END; i++) {
+		section = &default_sections[i];
+		INIT_LIST_HEAD(&section->items);
+
+		items = default_config_items[i];
+		for (j = 0; items[j].name != NULL; j++)
+			list_add_tail(&items[j].node, &section->items);
+
+		list_add_tail(&section->node, sections);
+	}
+
+	return set;
+}
+
 struct perf_config_set *perf_config_set__new(void)
 {
 	struct perf_config_set *set = zalloc(sizeof(*set));
 
 	if (set) {
-		INIT_LIST_HEAD(&set->sections);
+		perf_config_set__init(set);
 		perf_config(collect_config, set);
 	}
 
@@ -776,7 +801,8 @@ static void perf_config_section__purge(struct perf_config_section *section)
 
 	list_for_each_entry_safe(item, tmp, &section->items, node) {
 		list_del_init(&item->node);
-		perf_config_item__delete(item);
+		if (item->is_custom)
+			perf_config_item__delete(item);
 	}
 }
 
@@ -793,7 +819,8 @@ static void perf_config_set__purge(struct perf_config_set *set)
 
 	list_for_each_entry_safe(section, tmp, &set->sections, node) {
 		list_del_init(&section->node);
-		perf_config_section__delete(section);
+		if (section->is_custom)
+			perf_config_section__delete(section);
 	}
 }
 
diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
index 84dcc1d..1df96b7 100644
--- a/tools/perf/util/config.h
+++ b/tools/perf/util/config.h
@@ -14,6 +14,11 @@ enum perf_config_type {
 	CONFIG_TYPE_STRING
 };
 
+/**
+ * struct perf_config_item - element of perf's configs
+ *
+ * @is_custom: unknown or new config other than default config
+ */
 struct perf_config_item {
 	const char *name;
 	char *value;
@@ -27,11 +32,13 @@ struct perf_config_item {
 		const char *s;
 	} default_value;
 	enum perf_config_type type;
+	bool is_custom;
 	struct list_head node;
 };
 
 struct perf_config_section {
 	const char *name;
+	bool is_custom;
 	struct list_head items;
 	struct list_head node;
 };
-- 
2.5.0