X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Futil.h;h=5147ffc5555c2e6683210af9c3b3e89b0ab0ff0a;hb=772387d560e565abf212d5863698a6834f501639;hp=9eca8ec9adb09b029729a40f922ce5748c1854a7;hpb=d295e8e97acae13552a5b220d3fbcff8201064a2;p=openvswitch

diff --git a/lib/util.h b/lib/util.h
index 9eca8ec9..5147ffc5 100644
--- a/lib/util.h
+++ b/lib/util.h
@@ -82,6 +82,16 @@ extern const char *program_name;
 #define CONTAINER_OF(POINTER, STRUCT, MEMBER)                           \
         ((STRUCT *) (void *) ((char *) (POINTER) - offsetof (STRUCT, MEMBER)))
 
+/* Given POINTER, the address of the given MEMBER within an object of the type
+ * that that OBJECT points to, returns OBJECT as a "void *" pointer.  OBJECT
+ * must be an lvalue.
+ *
+ * This is the same as CONTAINER_OF except that it infers the structure type
+ * from the type of '*OBJECT'. */
+#define OBJECT_CONTAINING(POINTER, OBJECT, MEMBER)                      \
+        ((void *) ((char *) (POINTER)                                   \
+                   - ((char *) &(OBJECT)->MEMBER - (char *) (OBJECT))))
+
 #ifdef  __cplusplus
 extern "C" {
 #endif