core/rbtree: add const qualifier to some functions
See kernel commit f4b477c47332367d35686bd2b808c2156b96d7c7
----
The 'rb_first()', 'rb_last()', 'rb_next()' and 'rb_prev()' calls
take a pointer to an RB node or RB root. They do not change the
pointed objects, so add a 'const' qualifier in order to make life
of the users of these functions easier.
Indeed, if I have my own constant pointer &const struct my_type *p,
and I call 'rb_next(&p->rb)', I get a GCC warning:
warning: passing argument 1 of ?~@~Xrb_next?~@~Y discards qualifiers from pointer target type
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
----
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/src/rbtree.c b/src/rbtree.c
index 07e1041..9b7fe83 100644
--- a/src/rbtree.c
+++ b/src/rbtree.c
@@ -289,7 +289,7 @@
/*
* This function returns the first node (in sort order) of the tree.
*/
-struct rb_node *rb_first(struct rb_root *root)
+struct rb_node *rb_first(const struct rb_root *root)
{
struct rb_node *n;
@@ -301,7 +301,7 @@
return n;
}
-struct rb_node *rb_last(struct rb_root *root)
+struct rb_node *rb_last(const struct rb_root *root)
{
struct rb_node *n;
@@ -313,7 +313,7 @@
return n;
}
-struct rb_node *rb_next(struct rb_node *node)
+struct rb_node *rb_next(const struct rb_node *node)
{
struct rb_node *parent;
@@ -326,7 +326,7 @@
node = node->rb_right;
while (node->rb_left)
node=node->rb_left;
- return node;
+ return (struct rb_node *)node;
}
/* No right-hand children. Everything down and left is
@@ -341,7 +341,7 @@
return parent;
}
-struct rb_node *rb_prev(struct rb_node *node)
+struct rb_node *rb_prev(const struct rb_node *node)
{
struct rb_node *parent;
@@ -354,7 +354,7 @@
node = node->rb_left;
while (node->rb_right)
node=node->rb_right;
- return node;
+ return (struct rb_node *)node;
}
/* No left-hand children. Go up till we find an ancestor which