ofp-parse: Correctly update bucket lists if they are empty.

[cascardo/ovs.git] / lib / list.c

diff --git a/lib/list.c b/lib/list.c
index a236f8c..0bfa902 100644 (file)
--- a/lib/list.c
+++ b/lib/list.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2015 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,7 +15,6 @@
  */
 #include <config.h>
 #include "list.h"
-#include <assert.h>
 
 /* Initializes 'list' as an empty list. */
 void
@@ -47,8 +46,9 @@ list_insert(struct list *before, struct list *elem)
 void
 list_splice(struct list *before, struct list *first, struct list *last)
 {
-    if (first == last)
+    if (first == last) {
         return;
+    }
     last = last->prev;
 
     /* Cleanly remove 'first'...'last' from its current list. */
@@ -90,15 +90,31 @@ list_replace(struct list *element, const struct list *position)
 }
 
 /* Adjusts pointers around 'list' to compensate for 'list' having been moved
- * around in memory (e.g. as a consequence of realloc()).
+ * around in memory (e.g. as a consequence of realloc()), with original
+ * location 'orig'.
  *
- * This always works if 'list' is a member of a list, or if 'list' is the head
- * of a non-empty list.  It fails badly, however, if 'list' is the head of an
- * empty list; just use list_init() in that case. */
+ * ('orig' likely points to freed memory, but this function does not
+ * dereference 'orig', it only compares it to 'list'.  In a very pedantic
+ * language lawyer sense, this still yields undefined behavior, but it works
+ * with actual compilers.) */
 void
-list_moved(struct list *list)
+list_moved(struct list *list, const struct list *orig)
 {
-    list->prev->next = list->next->prev = list;
+    if (list->next == orig) {
+        list_init(list);
+    } else {
+        list->prev->next = list->next->prev = list;
+    }
+}
+
+/* Initializes 'dst' with the contents of 'src', compensating for moving it
+ * around in memory.  The effect is that, if 'src' was the head of a list, now
+ * 'dst' is the head of a list containing the same elements. */
+void
+list_move(struct list *dst, struct list *src)
+{
+    *dst = *src;
+    list_moved(dst, src);
 }
 
 /* Removes 'elem' from its list and returns the element that followed it.
@@ -136,9 +152,9 @@ list_pop_back(struct list *list)
 struct list *
 list_front(const struct list *list_)
 {
-    struct list *list = (struct list *) list_;
+    struct list *list = CONST_CAST(struct list *, list_);
 
-    assert(!list_is_empty(list));
+    ovs_assert(!list_is_empty(list));
     return list->next;
 }
 
@@ -147,9 +163,9 @@ list_front(const struct list *list_)
 struct list *
 list_back(const struct list *list_)
 {
-    struct list *list = (struct list *) list_;
+    struct list *list = CONST_CAST(struct list *, list_);
 
-    assert(!list_is_empty(list));
+    ovs_assert(!list_is_empty(list));
     return list->prev;
 }
 
@@ -161,8 +177,9 @@ list_size(const struct list *list)
     const struct list *e;
     size_t cnt = 0;
 
-    for (e = list->next; e != list; e = e->next)
+    for (e = list->next; e != list; e = e->next) {
         cnt++;
+    }
     return cnt;
 }