[PATCH 3/6] ptrlist: add pop_ptr_list()

[Luc Van Oostenryck <luc.vanoostenryck@gmail.com>]

Some algorithms need with a stack or a working list from which the
last element can be removed. The ptrlist API has a function to do
this but it's not typed and thus needs a wrapper for each type
it's used for.

Simplify this by adding a generic (but type-safe) macro for this
while also giving it a nicer name: pop_ptr_list().

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 ptrlist.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/ptrlist.h b/ptrlist.h
index 3b952097545f..0b06142252f5 100644
--- a/ptrlist.h
+++ b/ptrlist.h
@@ -67,6 +67,12 @@ extern void **__add_ptr_list_tag(struct ptr_list **, void *, unsigned long);
 		(__typeof__(&(ptr))) __add_ptr_list_tag(head, ptr, tag);\
 	})
 
+#define pop_ptr_list(l) ({						\
+		PTRLIST_TYPE(*(l)) ptr;					\
+		ptr = delete_ptr_list_last((struct ptr_list**)(l));	\
+		ptr;							\
+	})
+
 extern void __free_ptr_list(struct ptr_list **);
 #define free_ptr_list(list)	do {					\
 		VRFY_PTR_LIST(*(list));					\
-- 
2.30.0