From: Gabriel Laskar <gabriel@lse.epita.fr>
Date: Sun, 14 May 2017 14:33:16 +0000 (+0200)
Subject: util: use offsetof in container_of
X-Git-Tag: 1.7.901~55
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3236ee0d905dc24421d01b81e1792a72dd7dae31;p=platform%2Fupstream%2Flibinput.git

util: use offsetof in container_of

gcc and clang supports offsetof (defined in stddef.h) as defined by C99
and POSIX.1-2001, use it in container_of.

Signed-off-by: Gabriel Laskar <gabriel@lse.epita.fr>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
---

diff --git a/src/libinput-util.h b/src/libinput-util.h
index 9ecded7e..6d9bbe23 100644
--- a/src/libinput-util.h
+++ b/src/libinput-util.h
@@ -34,6 +34,7 @@
 #include <math.h>
 #include <stdarg.h>
 #include <stdbool.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
@@ -86,8 +87,8 @@ void list_remove(struct list *elm);
 bool list_empty(const struct list *list);
 
 #define container_of(ptr, sample, member)				\
-	(__typeof__(sample))((char *)(ptr)	-			\
-		 ((char *)&((typeof(sample))0)->member))
+	(__typeof__(sample))((char *)(ptr) -				\
+		 offsetof(__typeof__(*sample), member))
 
 #define list_for_each(pos, head, member)				\
 	for (pos = 0, pos = container_of((head)->next, pos, member);	\