container_of code cleanup

1 files changed, 37 insertions, 30 deletions

diff --git a/container_of.c b/container_of.c
index 5fa6134..13f8e69 100644
--- a/container_of.c
+++ b/container_of.c
@@ -1,7 +1,7 @@
 /*
  * File     : container_of.c
  * Author   : Jérémy Zurcher  <jeremy@asynk.ch>
- * Date     : 01/11/09 
+ * Date     : 01/11/09
  * License  :
  *
  *  Permission is hereby granted, free of charge, to any person obtaining
@@ -11,10 +11,10 @@
  *  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
@@ -29,40 +29,47 @@
 #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 data1;
-    int data2;
-    int data3;
-    int data4;
-    int data5;
-};
+#define container_of(ptr, type, member) ({		 \
+   const typeof( ((type *)0)->member ) *__mptr = (ptr);	 \
+   (type *)( (char *)__mptr - offsetof(type,member) );})
 
-#define my_offset(ptr, type, member) ( { (type*)(((char*)ptr)-offsetof(type,member)); } )
+#define containerof(ptr, type, member) ( { (type*)(((char*)ptr)-offsetof(type,member)); } )
 
-struct node n;
+struct node
+{
+   int data1;
+   int data2;
+   int data3;
+   int data4;
+   int data5;
+};
 
-struct node* use_container_of() {
-    return container_of( &n.data3, struct node, data3);
+static void _check(int cond, const char *msg)
+{
+   if(!cond)
+     {
+        fprintf(stderr,"%s\n",msg);
+        exit(EXIT_FAILURE);
+     }
 }
 
-struct node* use_mine() {
-    return my_offset( &n.data3, struct node, data3);
-/*    return (struct node*)(((char*)&n.daat3)-OFFSET); */
-}
+int main(int argc, char *argv[])
+{
+   struct node n;
 
-struct node* use_struct(){
-    return &n;
-}
+   _check((&n==container_of( &n.data1, struct node, data1)),"1 container_of failed");
+   _check((&n==container_of( &n.data2, struct node, data2)),"2 container_of failed");
+   _check((&n==container_of( &n.data3, struct node, data3)),"3 container_of failed");
+   _check((&n==container_of( &n.data4, struct node, data4)),"4 container_of failed");
+   _check((&n==container_of( &n.data5, struct node, data5)),"5 container_of failed");
 
-int main(int argc, char *argv[]) {
+   _check((&n==containerof( &n.data1, struct node, data1)),"1 container_of failed");
+   _check((&n==containerof( &n.data2, struct node, data2)),"2 container_of failed");
+   _check((&n==containerof( &n.data3, struct node, data3)),"3 container_of failed");
+   _check((&n==containerof( &n.data4, struct node, data4)),"4 container_of failed");
+   _check((&n==containerof( &n.data5, struct node, data5)),"5 container_of failed");
 
-    printf ("%X\n", (int)use_container_of());
-    printf ("%X\n", (int)use_mine());
-    printf ("%X\n", (int)use_struct());
+   printf("success\n");
 
-    return EXIT_SUCCESS;
+   return EXIT_SUCCESS;
 }