diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 37ef6697993..ed95354217e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2009-06-29  Ulrich Weigand  <uweigand@de.ibm.com>
+
+	* ada-lang.c (ada_index_type): Update comment.
+
 2009-06-29  Ulrich Weigand  <uweigand@de.ibm.com>
 
 	* ada-lang.c (ada_index_type): Make static.  Add NAME argument.
diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 7a49c453d9b..b35ff3cedbc 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -2408,7 +2408,10 @@ ada_array_element_type (struct type *type, int nindices)
 }
 
 /* The type of nth index in arrays of given type (n numbering from 1).
-   Does not examine memory.  */
+   Does not examine memory.  Throws an error if N is invalid or TYPE
+   is not an array type.  NAME is the name of the Ada attribute being
+   evaluated ('range, 'first, 'last, or 'length); it is used in building
+   the error message.  */
 
 static struct type *
 ada_index_type (struct type *type, int n, const char *name)