Added a way to for specifying lists as parts of structs. These lists

must be initialized with a special LIST_STRUCT_INIT() call before
using.

core/lib/list.h

@@ -64,7 +64,7 @@
  *
  * Author: Adam Dunkels <adam@sics.se>
  *
- * $Id: list.h,v 1.4 2010/06/15 18:54:27 adamdunkels Exp $
+ * $Id: list.h,v 1.5 2010/09/13 13:31:00 adamdunkels Exp $
  */
 #ifndef __LIST_H__
 #define __LIST_H__
@@ -90,6 +90,45 @@
          static void *LIST_CONCAT(name,_list) = NULL; \
          static list_t name = (list_t)&LIST_CONCAT(name,_list)
 
+/**
+ * Declare a linked list inside a structure declaraction.
+ *
+ * This macro declares a linked list with the specified \c type. The
+ * type \b must be a structure (\c struct) with its first element
+ * being a pointer. This pointer is used by the linked list library to
+ * form the linked lists.
+ *
+ * Internally, the list is defined as two items: the list itself and a
+ * pointer to the list. The pointer has the name of the parameter to
+ * the macro and the name of the list is a concatenation of the name
+ * and the suffix "_list". The pointer must point to the list for the
+ * list to work. Thus the list must be initialized before using.
+ *
+ * The list is initialized with the LIST_STRUCT_INIT() macro.
+ *
+ * \param name The name of the list.
+ */
+#define LIST_STRUCT(name) \
+         void *LIST_CONCAT(name,_list); \
+         list_t name
+
+/**
+ * Initialize a linked list that is part of a structure.
+ *
+ * This macro sets up the internal pointers in a list that has been
+ * defined as part of a struct. This macro must be called before using
+ * the list.
+ *
+ * \param struct_ptr A pointer to the struct
+ * \param name The name of the list.
+ */
+#define LIST_STRUCT_INIT(struct_ptr, name)                              \
+    do {                                                                \
+       (struct_ptr)->name = &((struct_ptr)->LIST_CONCAT(name,_list));   \
+       (struct_ptr)->LIST_CONCAT(name,_list) = NULL;                    \
+       list_init((struct_ptr)->name);                                   \
+    } while(0)
+
 /**
  * The linked list type.
  *