diff --git a/gcc/calls.c b/gcc/calls.c
index d3b21a9d0c0..f0350795bb1 100644
--- a/gcc/calls.c
+++ b/gcc/calls.c
@@ -996,6 +996,7 @@ expand_call (exp, target, ignore)
       /* See if this argument should be passed by invisible reference.  */
       if ((TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
 	   && contains_placeholder_p (TYPE_SIZE (type)))
+	  || TYPE_NEEDS_CONSTRUCTING (type)
 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
 	  || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, TYPE_MODE (type),
 					     type, argpos < n_named_args)
diff --git a/gcc/function.c b/gcc/function.c
index 16d4a935b83..9f3339613c7 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -3157,6 +3157,7 @@ assign_parms (fndecl, second_time)
 
       if ((TREE_CODE (TYPE_SIZE (passed_type)) != INTEGER_CST
 	   && contains_placeholder_p (TYPE_SIZE (passed_type)))
+	  || TYPE_NEEDS_CONSTRUCTING (passed_type)
 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
 	  || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
 					      passed_type, ! last_named)
diff --git a/gcc/tree.h b/gcc/tree.h
index 616dedf65eb..dbe5ff9cf5c 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -615,6 +615,10 @@ struct tree_block
    If set in a SET_TYPE, indicates a bitstring type. */
 #define TYPE_STRING_FLAG(NODE) ((NODE)->type.string_flag)
 
+/* Indicates that objects of this type must be initialized by calling a
+   function when they are created.  */
+#define TYPE_NEEDS_CONSTRUCTING(NODE) ((NODE)->type.needs_constructing_flag)
+
 struct tree_type
 {
   char common[sizeof (struct tree_common)];
@@ -632,6 +636,7 @@ struct tree_type
 
   unsigned string_flag : 1;
   unsigned no_force_blk_flag : 1;
+  unsigned needs_constructing_flag : 1;
   unsigned lang_flag_0 : 1;
   unsigned lang_flag_1 : 1;
   unsigned lang_flag_2 : 1;
@@ -639,7 +644,7 @@ struct tree_type
   unsigned lang_flag_4 : 1;
   unsigned lang_flag_5 : 1;
   unsigned lang_flag_6 : 1;
-  /* room for 7 more bits */
+  /* room for 6 more bits */
 
   unsigned int align;
   union tree_node *pointer_to;