1 files changed, 16 insertions, 0 deletions
diff --git a/erts/emulator/beam/erl_map.c b/erts/emulator/beam/erl_map.c
index fdd2d0c0f6..5e740aacdd 100644
--- a/erts/emulator/beam/erl_map.c
+++ b/erts/emulator/beam/erl_map.c
@@ -58,6 +58,8 @@
  * - maps:size/1
  * - maps:without/2
  *
+ * DEBUG: for sharing calculation
+ * - erts_internal:map_to_tuple_keys/1
  */
 
 /* erlang:map_size/1
@@ -819,3 +821,17 @@ int erts_validate_and_sort_map(map_t* mp)
     }
     return 1;
 }
+
+/*
+ * erts_internal:map_to_tuple_keys/1
+ *
+ * Used in erts_debug:size/1
+ */
+
+BIF_RETTYPE erts_internal_map_to_tuple_keys_1(BIF_ALIST_1) {
+    if (is_map(BIF_ARG_1)) {
+	map_t *mp = (map_t*)map_val(BIF_ARG_1);
+	BIF_RET(mp->keys);
+    }
+    BIF_ERROR(BIF_P, BADARG);
+}