include/c: add sizeof_member()

This macro returns size of struct member.

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/include/c.h b/include/c.h
index 1fa2dc766f38e9219df48c7c4f6ede045e00e035..4cb248f7f2385682e6cd3f0c527fb13f4e8cebbf 100644 (file)
--- a/include/c.h
+++ b/include/c.h
@@ -197,6 +197,10 @@
 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
 #endif
 
+#ifndef sizeof_member
+#define sizeof_member(TYPE, MEMBER) sizeof(((TYPE *)0)->MEMBER)
+#endif
+
 /*
  * container_of - cast a member of a structure out to the containing structure
  * @ptr:       the pointer to the member.