1 files changed, 68 insertions, 0 deletions
diff --git a/container_of.c b/container_of.c
new file mode 100644
index 0000000..2c0be09
--- /dev/null
+++ b/container_of.c
@@ -0,0 +1,68 @@
+/*
+ * File     : lfq_test.c
+ * Author   : Jérémy Zurcher  <jeremy@asynk.ch>
+ * Date     : 01/11/09 
+ * License  :
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining
+ *  a copy of this software and associated documentation files (the
+ *  "Software"), to deal in the Software without restriction, including
+ *  without limitation the rights to use, copy, modify, merge, publish,
+ *  distribute, sublicense, and/or sell copies of the Software, and to
+ *  permit persons to whom the Software is furnished to do so, subject to
+ *  the following conditions:
+ *  
+ *  The above copyright notice and this permission notice shall be
+ *  included in all copies or substantial portions of the Software.
+ *  
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include "stdio.h"
+#include "stdlib.h"
+#include "stddef.h"
+
+#define container_of(ptr, type, member) ({			\
+	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
+	(type *)( (char *)__mptr - offsetof(type,member) );})
+
+struct node {
+    int data;
+    int daat2;
+    int daat3;
+    int daat4;
+    int daaat4;
+};
+#define OFFSET offsetof(struct node,daat3)
+#define my_offset(ptr, type, member) ( { (type*)(((char*)ptr)-offsetof(type,member)); } )
+
+struct node n;
+
+struct node* use_container_of() {
+    return container_of( &n.daat3, struct node, daat3);
+}
+
+struct node* use_mine() {
+    return my_offset( &n.daat3, struct node, daat3);
+/*    return (struct node*)(((char*)&n.daat3)-OFFSET); */
+}
+
+struct node* use_struct(){
+    return &n;
+}
+
+int main(int argc, char *argv[]) {
+
+    printf ("%X\n", (int)use_container_of());
+    printf ("%X\n", (int)use_mine());
+    printf ("%X\n", (int)use_struct());
+
+    return EXIT_SUCCESS;
+}