macros.h: introduce sizeof_field macro

Handy for field size checks.

* macros.h (sizeof_field): New macro.
(offsetofend): Use it.

1 files changed, 3 insertions, 1 deletions

diff --git a/macros.h b/macros.h
index b94c1ff4c..2391b082f 100644
--- a/macros.h
+++ b/macros.h
@@ -37,9 +37,11 @@
 #  define ROUNDUP(val_, div_) (ROUNDUP_DIV((val_), (div_)) * (div_))
 # endif
 
+# define sizeof_field(type_, member_) (sizeof(((type_ *)0)->member_))
+
 # ifndef offsetofend
 #  define offsetofend(type_, member_)	\
-	(offsetof(type_, member_) + sizeof(((type_ *)0)->member_))
+	(offsetof(type_, member_) + sizeof_field(type_, member_))
 # endif
 
 # ifndef cast_ptr