llist.h: Adding a Single linked list implementation

Needing this for implementing chaining on hash collisions and
iam tired of implementing dynamic arrays / linked lists every time.

llist.h

@@ -0,0 +1,83 @@
+/* list.h
+ *
+ *   Copyright (C) 2011   Henrik Hautakoski <henrik@fiktivkod.org>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ *   MA 02110-1301, USA.
+ *
+ *   Inspired by include/linux/list.h in Linux Kernel.
+ */
+
+#ifndef LLIST_H
+#define LLIST_H
+
+#include <stddef.h>
+
+struct llist {
+	struct llist *next;
+};
+
+#define LLIST_INIT { NULL }
+
+#define llist_entry(ptr, type, member) \
+	((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
+
+static inline void llist_add(struct llist *list, struct llist *new) {
+
+	for(; list->next; list = list->next);
+
+	list->next = new;
+	new->next = NULL;
+}
+
+static inline void llist_unlink(struct llist *prev, struct llist *entry) {
+
+	if (prev != entry) {
+		prev->next = entry->next;
+		entry->next = NULL;
+	}
+}
+
+static inline void llist_del(struct llist *list, struct llist *entry) {
+
+	for(; list->next; list = list->next) {
+
+		if (list->next == entry) {
+			llist_unlink(list, entry);
+			break;
+		}
+	}
+}
+
+
+
+static inline int llist_empty(struct llist *list) {
+
+	return !list || list->next == NULL;
+}
+
+#define llist_foreach(pos, head) \
+	for(pos = (head); pos; pos = pos->next)
+
+#define llist_foreach_entry(pos, head, member) \
+	for(pos = llist_entry(head, typeof(*pos), member); \
+		pos->member; pos = llist_entry(pos->member.next, \
+		typeof(*pos), member))
+
+#define llist_foreach_safe(it, n, head) \
+	for(it = (head), n = it->next; it; \
+		it = n, n = (n) ? it->next : NULL)
+
+#endif /* LLIST_H */