lib: Move list function definitions into a source file

This moves the function definitions of list.h into a separate source
file to avod linker errors when including the file in more than one
source file.

1 files changed, 125 insertions, 0 deletions

diff --git a/src/lib/list.c b/src/lib/list.c
new file mode 100644
index 00000000..75063e22
--- /dev/null
+++ b/src/lib/list.c
@@ -0,0 +1,125 @@
+/*
+ * Ouroboros - Copyright (C) 2016
+ *
+ * Simple doubly linked list implementation.
+ *
+ * Some of the internal functions ("__xxx") are useful when
+ * manipulating whole lists rather than single entries, as
+ * sometimes we already know the next/prev entries and we can
+ * generate better code by using them directly rather than
+ * using the generic single-entry routines.
+ *
+ * This file is from the Linux Kernel (include/linux/list.h)
+ * and modified by simply removing hardware prefetching of list items.
+ * Here by copyright, credits attributed to wherever they belong.
+ * Kulesh Shanmugasundaram (kulesh [squiggly] isis.poly.edu)
+ *
+ *    Sander Vrijders <[email protected]>
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <ouroboros/list.h>
+
+static void __list_add(struct list_head * new,
+                       struct list_head * prev,
+                       struct list_head * next)
+{
+        next->prev = new;
+        new->next = next;
+        new->prev = prev;
+        prev->next = new;
+}
+
+void list_add(struct list_head * new,
+              struct list_head * head)
+{
+        __list_add(new, head, head->next);
+}
+
+void list_add_tail(struct list_head * new,
+                   struct list_head * head)
+{
+        __list_add(new, head->prev, head);
+}
+
+static void __list_del(struct list_head * prev,
+                       struct list_head * next)
+{
+        next->prev = prev;
+        prev->next = next;
+}
+
+void list_del(struct list_head * entry)
+{
+        __list_del(entry->prev, entry->next);
+        entry->next = (void *) 0;
+        entry->prev = (void *) 0;
+}
+
+void list_del_init(struct list_head * entry)
+{
+        __list_del(entry->prev, entry->next);
+        INIT_LIST_HEAD(entry);
+}
+
+void list_move(struct list_head * list,
+               struct list_head * head)
+{
+        __list_del(list->prev, list->next);
+        list_add(list, head);
+}
+
+void list_move_tail(struct list_head * list,
+                    struct list_head * head)
+{
+        __list_del(list->prev, list->next);
+        list_add_tail(list, head);
+}
+
+int list_empty(struct list_head * head)
+{
+        return head->next == head;
+}
+
+static void __list_splice(struct list_head *list,
+                          struct list_head *head)
+{
+        struct list_head *first = list->next;
+        struct list_head *last = list->prev;
+        struct list_head *at = head->next;
+
+        first->prev = head;
+        head->next = first;
+
+        last->next = at;
+        at->prev = last;
+}
+
+void list_splice(struct list_head * list,
+                 struct list_head * head)
+{
+        if (!list_empty(list))
+                __list_splice(list, head);
+}
+
+void list_splice_init(struct list_head * list,
+                      struct list_head * head)
+{
+        if (!list_empty(list)) {
+                __list_splice(list, head);
+                INIT_LIST_HEAD(list);
+        }
+}