tools lib traceevent: Add tep_load_plugins_hook() API

Add the API function tep_load_plugins_hook() to the traceevent API to
allow tools a common method to load in the plugins that are part of the
lib traceevent library.

Link: http://lore.kernel.org/linux-trace-devel/20190802110101.14759-4-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-4-tz.stoyanov@gmail.comSigned-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185703.946652691@goodmis.orgSigned-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/event-parse.h

@@ -396,6 +396,12 @@ struct tep_plugin_list;
 struct tep_plugin_list *tep_load_plugins(struct tep_handle *tep);
 void tep_unload_plugins(struct tep_plugin_list *plugin_list,
 			struct tep_handle *tep);
+void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
+			   void (*load_plugin)(struct tep_handle *tep,
+					       const char *path,
+					       const char *name,
+					       void *data),
+			   void *data);
 char **tep_plugin_list_options(void);
 void tep_plugin_free_options_list(char **list);
 int tep_plugin_add_options(const char *name,

tools/lib/traceevent/event-plugin.c

@@ -365,20 +365,19 @@ load_plugins_dir(struct tep_handle *tep, const char *suffix,
 	closedir(dir);
 }
 
-static void
-load_plugins(struct tep_handle *tep, const char *suffix,
-	     void (*load_plugin)(struct tep_handle *tep,
-				 const char *path,
-				 const char *name,
-				 void *data),
-	     void *data)
+void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
+			   void (*load_plugin)(struct tep_handle *tep,
+					       const char *path,
+					       const char *name,
+					       void *data),
+			   void *data)
 {
 	char *home;
 	char *path;
 	char *envdir;
 	int ret;
 
-	if (tep->flags & TEP_DISABLE_PLUGINS)
+	if (tep && tep->flags & TEP_DISABLE_PLUGINS)
 		return;
 
 	/*
@@ -386,7 +385,7 @@ load_plugins(struct tep_handle *tep, const char *suffix,
 	 * check that first.
 	 */
 #ifdef PLUGIN_DIR
-	if (!(tep->flags & TEP_DISABLE_SYS_PLUGINS))
+	if (!tep || !(tep->flags & TEP_DISABLE_SYS_PLUGINS))
 		load_plugins_dir(tep, suffix, PLUGIN_DIR,
 				 load_plugin, data);
 #endif
@@ -423,7 +422,7 @@ tep_load_plugins(struct tep_handle *tep)
 {
 	struct tep_plugin_list *list = NULL;
 
-	load_plugins(tep, ".so", load_plugin, &list);
+	tep_load_plugins_hook(tep, ".so", load_plugin, &list);
 	return list;
 }