alist: Add for-loop helpers

Add some macros which permit easy iteration through an alist, similar to
those provided by the 'list' implementation.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/alist.c b/lib/alist.c
index 7730fe0d473..1a4b4fb9c40 100644
--- a/lib/alist.c
+++ b/lib/alist.c
@@ -118,6 +118,13 @@ int alist_calc_index(const struct alist *lst, const void *ptr)
 	return index;
 }
 
+bool alist_chk_ptr(const struct alist *lst, const void *ptr)
+{
+	int index = alist_calc_index(lst, ptr);
+
+	return index >= 0 && index < lst->count;
+}
+
 const void *alist_next_ptrd(const struct alist *lst, const void *ptr)
 {
 	int index = alist_calc_index(lst, ptr);