Add "const" attributes where possible: first cut.

6 files changed, 36 insertions, 33 deletions

diff --git a/lib/datastruct/btree.c b/lib/datastruct/btree.c
index 23b067be6..b99f667d1 100644
--- a/lib/datastruct/btree.c
+++ b/lib/datastruct/btree.c
@@ -55,7 +55,8 @@ static uint32_t _shuffle(uint32_t k)
 #endif
 }
 
-static struct node **_lookup(struct node **c, uint32_t key, struct node **p)
+static struct node **_lookup(struct node *const *c, uint32_t key,
+			     struct node **p)
 {
 	*p = NULL;
 	while (*c) {
@@ -70,10 +71,10 @@ static struct node **_lookup(struct node **c, uint32_t key, struct node **p)
 			c = &(*c)->r;
 	}
 
-	return c;
+	return (struct node **)c;
 }
 
-void *btree_lookup(struct btree *t, uint32_t k)
+void *btree_lookup(const struct btree *t, uint32_t k)
 {
 	uint32_t key = _shuffle(k);
 	struct node *p, **c = _lookup(&t->root, key, &p);
@@ -102,7 +103,7 @@ int btree_insert(struct btree *t, uint32_t k, void *data)
 	return 1;
 }
 
-void *btree_get_data(struct btree_iter *it)
+void *btree_get_data(const struct btree_iter *it)
 {
 	return ((struct node *) it)->data;
 }
@@ -114,7 +115,7 @@ static struct node *_left(struct node *n)
 	return n;
 }
 
-struct btree_iter *btree_first(struct btree *t)
+struct btree_iter *btree_first(const struct btree *t)
 {
 	if (!t->root)
 		return NULL;
@@ -122,7 +123,7 @@ struct btree_iter *btree_first(struct btree *t)
 	return (struct btree_iter *) _left(t->root);
 }
 
-struct btree_iter *btree_next(struct btree_iter *it)
+struct btree_iter *btree_next(const struct btree_iter *it)
 {
 	struct node *n = (struct node *) it;
 	uint32_t k = n->key;
diff --git a/lib/datastruct/btree.h b/lib/datastruct/btree.h
index 66dea80ea..f91ced82a 100644
--- a/lib/datastruct/btree.h
+++ b/lib/datastruct/btree.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.  
+ * Copyright (C) 2001-2004, 2007 Sistina Software, Inc. All rights reserved.  
  * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
  *
  * This file is part of LVM2.
@@ -20,13 +20,13 @@ struct btree;
 
 struct btree *btree_create(struct dm_pool *mem);
 
-void *btree_lookup(struct btree *t, uint32_t k);
+void *btree_lookup(const struct btree *t, uint32_t k);
 int btree_insert(struct btree *t, uint32_t k, void *data);
 
 struct btree_iter;
-void *btree_get_data(struct btree_iter *it);
+void *btree_get_data(const struct btree_iter *it);
 
-struct btree_iter *btree_first(struct btree *t);
-struct btree_iter *btree_next(struct btree_iter *it);
+struct btree_iter *btree_first(const struct btree *t);
+struct btree_iter *btree_next(const struct btree_iter *it);
 
 #endif
diff --git a/lib/datastruct/list.c b/lib/datastruct/list.c
index 17ee0e28e..3918cf520 100644
--- a/lib/datastruct/list.c
+++ b/lib/datastruct/list.c
@@ -68,7 +68,7 @@ void list_del(struct list *elem)
 /*
  * Is the list empty?
  */
-int list_empty(struct list *head)
+int list_empty(const struct list *head)
 {
 	return head->n == head;
 }
@@ -76,7 +76,7 @@ int list_empty(struct list *head)
 /*
  * Is this the first element of the list?
  */
-int list_start(struct list *head, struct list *elem)
+int list_start(const struct list *head, const struct list *elem)
 {
 	return elem->p == head;
 }
@@ -84,7 +84,7 @@ int list_start(struct list *head, struct list *elem)
 /*
  * Is this the last element of the list?
  */
-int list_end(struct list *head, struct list *elem)
+int list_end(const struct list *head, const struct list *elem)
 {
 	return elem->n == head;
 }
@@ -92,7 +92,7 @@ int list_end(struct list *head, struct list *elem)
 /*
  * Return first element of the list or NULL if empty
  */
-struct list *list_first(struct list *head)
+struct list *list_first(const struct list *head)
 {
 	return (list_empty(head) ? NULL : head->n);
 }
@@ -100,7 +100,7 @@ struct list *list_first(struct list *head)
 /*
  * Return last element of the list or NULL if empty
  */
-struct list *list_last(struct list *head)
+struct list *list_last(const struct list *head)
 {
 	return (list_empty(head) ? NULL : head->p);
 }
@@ -108,7 +108,7 @@ struct list *list_last(struct list *head)
 /*
  * Return the previous element of the list, or NULL if we've reached the start.
  */
-struct list *list_prev(struct list *head, struct list *elem)
+struct list *list_prev(const struct list *head, const struct list *elem)
 {
 	return (list_start(head, elem) ? NULL : elem->p);
 }
@@ -116,7 +116,7 @@ struct list *list_prev(struct list *head, struct list *elem)
 /*
  * Return the next element of the list, or NULL if we've reached the end.
  */
-struct list *list_next(struct list *head, struct list *elem)
+struct list *list_next(const struct list *head, const struct list *elem)
 {
 	return (list_end(head, elem) ? NULL : elem->n);
 }
diff --git a/lib/datastruct/list.h b/lib/datastruct/list.h
index 316c537aa..00d4d743e 100644
--- a/lib/datastruct/list.h
+++ b/lib/datastruct/list.h
@@ -57,37 +57,37 @@ void list_del(struct list *elem);
 /*
  * Is the list empty?
  */
-int list_empty(struct list *head);
+int list_empty(const struct list *head);
 
 /*
  * Is this the first element of the list?
  */
-int list_start(struct list *head, struct list *elem);
+int list_start(const struct list *head, const struct list *elem);
 
 /*
  * Is this the last element of the list?
  */
-int list_end(struct list *head, struct list *elem);
+int list_end(const struct list *head, const struct list *elem);
 
 /*
  * Return first element of the list or NULL if empty
  */
-struct list *list_first(struct list *head);
+struct list *list_first(const struct list *head);
 
 /*
  * Return last element of the list or NULL if empty
  */
-struct list *list_last(struct list *head);
+struct list *list_last(const struct list *head);
 
 /*
  * Return the previous element of the list, or NULL if we've reached the start.
  */
-struct list *list_prev(struct list *head, struct list *elem);
+struct list *list_prev(const struct list *head, const struct list *elem);
 
 /*
  * Return the next element of the list, or NULL if we've reached the end.
  */
-struct list *list_next(struct list *head, struct list *elem);
+struct list *list_next(const struct list *head, const struct list *elem);
 
 /*
  * Given the address v of an instance of 'struct list' called 'head' 
diff --git a/lib/datastruct/str_list.c b/lib/datastruct/str_list.c
index 94705dc42..68660d990 100644
--- a/lib/datastruct/str_list.c
+++ b/lib/datastruct/str_list.c
@@ -66,7 +66,8 @@ int str_list_del(struct list *sll, const char *str)
 	return 1;
 }
 
-int str_list_dup(struct dm_pool *mem, struct list *sllnew, struct list *sllold)
+int str_list_dup(struct dm_pool *mem, struct list *sllnew,
+		 const struct list *sllold)
 {
 	struct str_list *sl;
 
@@ -85,7 +86,7 @@ int str_list_dup(struct dm_pool *mem, struct list *sllnew, struct list *sllold)
 /*
  * Is item on list?
  */
-int str_list_match_item(struct list *sll, const char *str)
+int str_list_match_item(const struct list *sll, const char *str)
 {
 	struct str_list *sl;
 
@@ -99,7 +100,7 @@ int str_list_match_item(struct list *sll, const char *str)
 /*
  * Is at least one item on both lists?
  */
-int str_list_match_list(struct list *sll, struct list *sll2)
+int str_list_match_list(const struct list *sll, const struct list *sll2)
 {
 	struct str_list *sl;
 
@@ -113,7 +114,7 @@ int str_list_match_list(struct list *sll, struct list *sll2)
 /*
  * Do both lists contain the same set of items?
  */
-int str_list_lists_equal(struct list *sll, struct list *sll2)
+int str_list_lists_equal(const struct list *sll, const struct list *sll2)
 {
 	struct str_list *sl;
 
diff --git a/lib/datastruct/str_list.h b/lib/datastruct/str_list.h
index 329a1f652..46fb76d71 100644
--- a/lib/datastruct/str_list.h
+++ b/lib/datastruct/str_list.h
@@ -19,9 +19,10 @@
 struct list *str_list_create(struct dm_pool *mem);
 int str_list_add(struct dm_pool *mem, struct list *sll, const char *str);
 int str_list_del(struct list *sll, const char *str);
-int str_list_match_item(struct list *sll, const char *str);
-int str_list_match_list(struct list *sll, struct list *sll2);
-int str_list_lists_equal(struct list *sll, struct list *sll2);
-int str_list_dup(struct dm_pool *mem, struct list *sllnew, struct list *sllold);
+int str_list_match_item(const struct list *sll, const char *str);
+int str_list_match_list(const struct list *sll, const struct list *sll2);
+int str_list_lists_equal(const struct list *sll, const struct list *sll2);
+int str_list_dup(struct dm_pool *mem, struct list *sllnew,
+		 const struct list *sllold);
 
 #endif