[PATCH v4 1/3] tools: add sizeof_field and offsetof_end macros

["Petr Beneš" <w1benny@xxxxxxxxx>]

From: Petr Beneš <w1benny@xxxxxxxxx>

* `sizeof_field` returns the size of a specific struct member
* `offsetof_end` returns the offset to the end of the member within the struct

It will be useful in upcoming layout checks of SMBIOS structs.

Signed-off-by: Petr Beneš <w1benny@xxxxxxxxx>
---
 tools/include/xen-tools/common-macros.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/include/xen-tools/common-macros.h 
b/tools/include/xen-tools/common-macros.h
index 0088208c2e..3899e06753 100644
--- a/tools/include/xen-tools/common-macros.h
+++ b/tools/include/xen-tools/common-macros.h
@@ -83,6 +83,11 @@
 #define __packed __attribute__((__packed__))
 #endif
 
+#define sizeof_field(type, member) sizeof(((type *)NULL)->member)
+
+#define offsetof_end(type, member) \
+    (offsetof(type, member) + sizeof_field(type, member))
+
 #define container_of(ptr, type, member) ({              \
     typeof(((type *)0)->member) *mptr__ = (ptr);        \
     (type *)((char *)mptr__ - offsetof(type, member));  \
-- 
2.34.1