parse-events: Add pevent_event_common_fields() and pevent_event_fields()

Add the functions pevent_event_common_fields() and pevent_event_fields()
that return an allocated array of the events common or event specific
fields.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

2 files changed, 58 insertions, 0 deletions

diff --git a/parse-events.c b/parse-events.c
index db60c7b..b483e85 100644
--- a/parse-events.c
+++ b/parse-events.c
@@ -3599,6 +3599,62 @@ struct event_format **pevent_list_events(struct pevent *pevent, enum event_sort_
         return events;
 }
 
+static struct format_field **
+get_event_fields(const char *type, const char *name,
+                 int count, struct format_field *list)
+{
+        struct format_field **fields;
+        struct format_field *field;
+        int i = 0;
+
+        fields = malloc_or_die(sizeof(*fields) * (count + 1));
+        for (field = list; field; field = field->next) {
+                fields[i++] = field;
+                if (i == count + 1) {
+                        warning("event %s has more %s fields than specified",
+                                name, type);
+                        i--;
+                        break;
+                }
+        }
+
+        if (i != count)
+                warning("event %s has less %s fields than specified",
+                        name, type);
+
+        fields[i] = NULL;
+
+        return fields;
+}
+
+/**
+ * pevent_event_common_fields - return a list of common fields for an event
+ * @event: the event to return the common fields of.
+ *
+ * Returns an allocated array of fields. The last item in the array is NULL.
+ * The array must be freed with free().
+ */
+struct format_field **pevent_event_common_fields(struct event_format *event)
+{
+        return get_event_fields("common", event->name,
+                                event->format.nr_common,
+                                event->format.common_fields);
+}
+
+/**
+ * pevent_event_fields - return a list of event specific fields for an event
+ * @event: the event to return the fields of.
+ *
+ * Returns an allocated array of fields. The last item in the array is NULL.
+ * The array must be freed with free().
+ */
+struct format_field **pevent_event_fields(struct event_format *event)
+{
+        return get_event_fields("event", event->name,
+                                event->format.nr_fields,
+                                event->format.fields);
+}
+
 static void print_fields(struct trace_seq *s, struct print_flag_sym *field)
 {
         trace_seq_printf(s, "{ %s, %s }", field->value, field->str);
diff --git a/parse-events.h b/parse-events.h
index 73fc2ea..bccb9ee 100644
--- a/parse-events.h
+++ b/parse-events.h
@@ -429,6 +429,8 @@ void pevent_event_info(struct trace_seq *s, struct event_format *event,
                        struct record *record);
 
 struct event_format **pevent_list_events(struct pevent *pevent, enum event_sort_type);
+struct format_field **pevent_event_common_fields(struct event_format *event);
+struct format_field **pevent_event_fields(struct event_format *event);
 
 static inline int pevent_get_cpus(struct pevent *pevent)
 {