MINOR: lists: add LIST_ADDED() to check if an element belongs to a list
Some code parts use LIST_ISEMPTY() a lot on list elements to detect
if they were reset consecutive to their removal from a list, but this
test is always confusing as this was initially designed for list heads.
Instead let's have a new macro, LIST_ADDED(), which returns true when
the element is in a list (i.e. it's not "empty").
diff --git a/include/common/mini-clist.h b/include/common/mini-clist.h
index 648cbd5..592bb96 100644
--- a/include/common/mini-clist.h
+++ b/include/common/mini-clist.h
@@ -111,6 +111,11 @@
/* checks if the list head <lh> is empty or not */
#define LIST_ISEMPTY(lh) ((lh)->n == (lh))
+/* checks if the list element <el> was added to a list or not. This only
+ * works when detached elements are reinitialized (using LIST_DEL_INIT)
+ */
+#define LIST_ADDED(el) ((el)->n != (el))
+
/* returns a pointer of type <pt> to a structure following the element
* which contains list head <lh>, which is known as element <el> in
* struct pt.