[PATCH 1/3] KVM: selftests: Delete the unused sparsebit copy and count helpers

[Gokul K]

sparsebit_copy() and sparsebit_num_set() have no callers.  Nor does the
FUZZ harness at the bottom of lib/sparsebit.c, which exercises most of
the rest of the API and still builds and links with both removed.

sparsebit_copy() was the only non-recursive caller of
node_copy_subtree(), which leaves that unreachable too.  It is static,
so keeping it would trip -Wunused-function; delete it as well.

The comment on the num_set member gives sparsebit_num_set() as the
reason the count is maintained.  The member stays - it is what lets
sparsebit_all_set() answer in O(1), and the dump path prints it - so
point the comment at what still uses it.

No functional change intended.

Signed-off-by: Gokul K <gokul02k@xxxxxxxxx>
---
 .../testing/selftests/kvm/include/sparsebit.h |  2 -
 tools/testing/selftests/kvm/lib/sparsebit.c   | 63 +------------------
 2 files changed, 1 insertion(+), 64 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/sparsebit.h b/tools/testing/selftests/kvm/include/sparsebit.h
index e027e5790946..8a2ab11dae6f 100644
--- a/tools/testing/selftests/kvm/include/sparsebit.h
+++ b/tools/testing/selftests/kvm/include/sparsebit.h
@@ -30,7 +30,6 @@ typedef u64 sparsebit_num_t;
 
 struct sparsebit *sparsebit_alloc(void);
 void sparsebit_free(struct sparsebit **sbitp);
-void sparsebit_copy(struct sparsebit *dstp, const struct sparsebit *src);
 
 bool sparsebit_is_set(const struct sparsebit *sbit, sparsebit_idx_t idx);
 bool sparsebit_is_set_num(const struct sparsebit *sbit,
@@ -38,7 +37,6 @@ bool sparsebit_is_set_num(const struct sparsebit *sbit,
 bool sparsebit_is_clear(const struct sparsebit *sbit, sparsebit_idx_t idx);
 bool sparsebit_is_clear_num(const struct sparsebit *sbit,
 			    sparsebit_idx_t idx, sparsebit_num_t num);
-sparsebit_num_t sparsebit_num_set(const struct sparsebit *sbit);
 bool sparsebit_any_set(const struct sparsebit *sbit);
 bool sparsebit_any_clear(const struct sparsebit *sbit);
 bool sparsebit_all_set(const struct sparsebit *sbit);
diff --git a/tools/testing/selftests/kvm/lib/sparsebit.c b/tools/testing/selftests/kvm/lib/sparsebit.c
index 4d845000de15..8ce230af4f14 100644
--- a/tools/testing/selftests/kvm/lib/sparsebit.c
+++ b/tools/testing/selftests/kvm/lib/sparsebit.c
@@ -184,8 +184,7 @@ struct sparsebit {
 
 	/*
 	 * A redundant count of the total number of bits set.  Used for
-	 * diagnostic purposes and to change the time complexity of
-	 * sparsebit_num_set() from O(n) to O(1).
+	 * diagnostic purposes and to answer sparsebit_all_set() in O(1).
 	 * Note: Due to overflow, a value of 0 means none or all set.
 	 */
 	sparsebit_num_t num_set;
@@ -269,39 +268,6 @@ static struct node *node_prev(const struct sparsebit *s, struct node *np)
 }
 
 
-/* Allocates space to hold a copy of the node sub-tree pointed to by
- * subtree and duplicates the bit settings to the newly allocated nodes.
- * Returns the newly allocated copy of subtree.
- */
-static struct node *node_copy_subtree(const struct node *subtree)
-{
-	struct node *root;
-
-	/* Duplicate the node at the root of the subtree */
-	root = calloc(1, sizeof(*root));
-	if (!root) {
-		perror("calloc");
-		abort();
-	}
-
-	root->idx = subtree->idx;
-	root->mask = subtree->mask;
-	root->num_after = subtree->num_after;
-
-	/* As needed, recursively duplicate the left and right subtrees */
-	if (subtree->left) {
-		root->left = node_copy_subtree(subtree->left);
-		root->left->parent = root;
-	}
-
-	if (subtree->right) {
-		root->right = node_copy_subtree(subtree->right);
-		root->right->parent = root;
-	}
-
-	return root;
-}
-
 /* Searches for and returns a pointer to the node that describes the setting
  * of the bit given by idx.  A node describes the setting of a bit if its
  * index is within the bits described by the mask bits or the number of
@@ -964,22 +930,6 @@ void sparsebit_free(struct sparsebit **sbitp)
 	*sbitp = NULL;
 }
 
-/* Makes a copy of the sparsebit array given by s, to the sparsebit
- * array given by d.  Note, d must have already been allocated via
- * sparsebit_alloc().  It can though already have bits set, which
- * if different from src will be cleared.
- */
-void sparsebit_copy(struct sparsebit *d, const struct sparsebit *s)
-{
-	/* First clear any bits already set in the destination */
-	sparsebit_clear_all(d);
-
-	if (s->root) {
-		d->root = node_copy_subtree(s->root);
-		d->num_set = s->num_set;
-	}
-}
-
 /* Returns whether num consecutive bits starting at idx are all set.  */
 bool sparsebit_is_set_num(const struct sparsebit *s,
 	sparsebit_idx_t idx, sparsebit_num_t num)
@@ -1035,17 +985,6 @@ bool sparsebit_is_clear_num(const struct sparsebit *s,
 	return next_set == 0 || next_set - idx >= num;
 }
 
-/* Returns the total number of bits set.  Note: 0 is also returned for
- * the case of all bits set.  This is because with all bits set, there
- * is 1 additional bit set beyond what can be represented in the return
- * value.  Use sparsebit_any_set(), instead of sparsebit_num_set() > 0,
- * to determine if the sparsebit array has any bits set.
- */
-sparsebit_num_t sparsebit_num_set(const struct sparsebit *s)
-{
-	return s->num_set;
-}
-
 /* Returns whether any bit is set in the sparsebit array.  */
 bool sparsebit_any_set(const struct sparsebit *s)
 {
-- 
2.54.0