shared: add nm_c_list_elem_find_first() helper macro

- add nm_c_list_elem_find_first() macro that takes a predicate
  and returns the first match.

  This macro has a non-function-like behavior, which we often try to
  avoid because macros should behave like functions. In this case it's
  however convenient, so let's do it.
  Also, despite being non-function-like, it should be pretty hard to
  use wrongly.

- rename nm_c_list_elem_find_first() to nm_c_list_elem_find_first_ptr().

2 files changed, 21 insertions, 10 deletions

diff --git a/shared/nm-glib-aux/nm-c-list.h b/shared/nm-glib-aux/nm-c-list.h
index 7512730d81..07c526dcb0 100644
--- a/shared/nm-glib-aux/nm-c-list.h
+++ b/shared/nm-glib-aux/nm-c-list.h
@@ -88,8 +88,25 @@ nm_c_list_elem_free_all (CList *head, GDestroyNotify free_fcn)
 		nm_c_list_elem_free_full (elem, free_fcn);
 }
 
+#define nm_c_list_elem_find_first(head, arg, predicate) \
+	({ \
+		CList *const _head = (head); \
+		NMCListElem *_result = NULL; \
+		NMCListElem *_elem; \
+		\
+		c_list_for_each_entry (_elem, _head, lst) { \
+			void *const arg = _elem->data; \
+			\
+			if (predicate) { \
+				_result = _elem; \
+				break; \
+			} \
+		} \
+		_result; \
+	})
+
 /**
- * nm_c_list_elem_find_first:
+ * nm_c_list_elem_find_first_ptr:
  * @head: the @CList head of a list containing #NMCListElem elements.
  *   Note that the head is not itself part of the list.
  * @needle: the needle pointer.
@@ -100,15 +117,9 @@ nm_c_list_elem_free_all (CList *head, GDestroyNotify free_fcn)
  * Returns: the found list element or %NULL if not found.
  */
 static inline NMCListElem *
-nm_c_list_elem_find_first (CList *head, gconstpointer needle)
+nm_c_list_elem_find_first_ptr (CList *head, gconstpointer needle)
 {
-	NMCListElem *elem;
-
-	c_list_for_each_entry (elem, head, lst) {
-		if (elem->data == needle)
-			return elem;
-	}
-	return NULL;
+	return nm_c_list_elem_find_first (head, x, x == needle);
 }
 
 /*****************************************************************************/
diff --git a/src/nm-manager.c b/src/nm-manager.c
index 64cdb9aed2..311bb68dd9 100644
--- a/src/nm-manager.c
+++ b/src/nm-manager.c
@@ -2134,7 +2134,7 @@ connection_changed_on_idle (NMManager *self,
 	if (priv->connection_changed_on_idle_id == 0)
 		priv->connection_changed_on_idle_id = g_idle_add (connection_changed_on_idle_cb, self);
 
-	if (!nm_c_list_elem_find_first (&priv->connection_changed_on_idle_lst, sett_conn)) {
+	if (!nm_c_list_elem_find_first_ptr (&priv->connection_changed_on_idle_lst, sett_conn)) {
 		c_list_link_tail (&priv->connection_changed_on_idle_lst,
 		                  &nm_c_list_elem_new_stale (g_object_ref (sett_conn))->lst);
 	}