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authorArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2009-01-10 11:12:09 +0000
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-10 06:04:33 -0800
commitf4b477c47332367d35686bd2b808c2156b96d7c7 (patch)
treeab8a2cf098b69be9ed7a44426106a7af596241d9 /lib/rbtree.c
parentcfce41a6d643c001d416ead960caf04fae2d609a (diff)
downloadlinux-f4b477c47332367d35686bd2b808c2156b96d7c7.tar.gz
rbtree: add const qualifier to some functions
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 ‘rb_next’ 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>
Diffstat (limited to 'lib/rbtree.c')
-rw-r--r--lib/rbtree.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/lib/rbtree.c b/lib/rbtree.c
index 48499c2d88cc..9956b99649f0 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -292,7 +292,7 @@ EXPORT_SYMBOL(rb_erase);
 /*
  * 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;
 
@@ -305,7 +305,7 @@ struct rb_node *rb_first(struct rb_root *root)
 }
 EXPORT_SYMBOL(rb_first);
 
-struct rb_node *rb_last(struct rb_root *root)
+struct rb_node *rb_last(const struct rb_root *root)
 {
 	struct rb_node	*n;
 
@@ -318,7 +318,7 @@ struct rb_node *rb_last(struct rb_root *root)
 }
 EXPORT_SYMBOL(rb_last);
 
-struct rb_node *rb_next(struct rb_node *node)
+struct rb_node *rb_next(const struct rb_node *node)
 {
 	struct rb_node *parent;
 
@@ -331,7 +331,7 @@ struct rb_node *rb_next(struct rb_node *node)
 		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
@@ -347,7 +347,7 @@ struct rb_node *rb_next(struct rb_node *node)
 }
 EXPORT_SYMBOL(rb_next);
 
-struct rb_node *rb_prev(struct rb_node *node)
+struct rb_node *rb_prev(const struct rb_node *node)
 {
 	struct rb_node *parent;
 
@@ -360,7 +360,7 @@ struct rb_node *rb_prev(struct rb_node *node)
 		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