MINOR: list: add LIST_SPLICE() to merge one list into another
This will move the contents of list <old> at the beginning of list
<new>.
diff --git a/include/common/mini-clist.h b/include/common/mini-clist.h
index 592bb96..0cdddce 100644
--- a/include/common/mini-clist.h
+++ b/include/common/mini-clist.h
@@ -86,6 +86,14 @@
/* adds an element at the end of a list ; returns the element */
#define LIST_ADDQ(lh, el) ({ (el)->p = (lh)->p; (el)->p->n = (lh)->p = (el); (el)->n = (lh); (el); })
+/* adds the contents of a list <old> at the beginning of another list <new>. The old list head remains untouched. */
+#define LIST_SPLICE(new, old) do { \
+ if (!LIST_ISEMPTY(old)) { \
+ (old)->p->n = (new)->n; (old)->n->p = (new); \
+ (new)->n->p = (old)->p; (new)->n = (old)->n; \
+ } \
+ } while (0)
+
/* removes an element from a list and returns it */
#define LIST_DEL(el) ({ typeof(el) __ret = (el); (el)->n->p = (el)->p; (el)->p->n = (el)->n; (__ret); })