trans.c (Call_to_gnu): For an Out parameter passed by copy and that don't need to be copied in...

	* gcc-interface/trans.c (Call_to_gnu): For an Out parameter passed by
	copy and that don't need to be  copied in, only evaluate its address.

From-SVN: r204943

1 files changed, 17 insertions, 5 deletions

diff --git a/gcc/ada/gcc-interface/trans.c b/gcc/ada/gcc-interface/trans.c
index b6a8be8..cbfb7e7 100644
--- a/gcc/ada/gcc-interface/trans.c
+++ b/gcc/ada/gcc-interface/trans.c
@@ -4130,9 +4130,7 @@ Call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target,
 	gnu_name
 	  = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_name))), gnu_name);
 
-      /* If we have not saved a GCC object for the formal, it means it is an
-	 Out parameter not passed by reference and that need not be copied in.
-	 Otherwise, first see if the parameter is passed by reference.  */
+      /* First see if the parameter is passed by reference.  */
       if (is_true_formal_parm && DECL_BY_REF_P (gnu_formal))
 	{
 	  if (Ekind (gnat_formal) != E_In_Parameter)
@@ -4178,6 +4176,9 @@ Call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target,
 	  gnu_formal_type = TREE_TYPE (gnu_formal);
 	  gnu_actual = build_unary_op (ADDR_EXPR, gnu_formal_type, gnu_actual);
 	}
+
+      /* Then see if the parameter is an array passed to a foreign convention
+	 subprogram.  */
       else if (is_true_formal_parm && DECL_BY_COMPONENT_PTR_P (gnu_formal))
 	{
 	  gnu_formal_type = TREE_TYPE (gnu_formal);
@@ -4198,6 +4199,8 @@ Call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target,
 	     but this is the most likely to work in all cases.  */
 	  gnu_actual = build_unary_op (ADDR_EXPR, gnu_formal_type, gnu_actual);
 	}
+
+      /* Then see if the parameter is passed by descriptor.  */
       else if (is_true_formal_parm && DECL_BY_DESCRIPTOR_P (gnu_formal))
 	{
 	  gnu_actual = convert (gnu_formal_type, gnu_actual);
@@ -4214,6 +4217,8 @@ Call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target,
 					 (TREE_TYPE (TREE_TYPE (gnu_formal)),
 					  gnu_actual, gnat_actual));
 	}
+
+      /* Otherwise the parameter is passed by copy.  */
       else
 	{
 	  tree gnu_size;
@@ -4221,11 +4226,18 @@ Call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target,
 	  if (Ekind (gnat_formal) != E_In_Parameter)
 	    gnu_name_list = tree_cons (NULL_TREE, gnu_name, gnu_name_list);
 
+	  /* If we didn't create a PARM_DECL for the formal, this means that
+	     it is an Out parameter not passed by reference and that need not
+	     be copied in.  In this case, the value of the actual need not be
+	     read.  However, we still need to make sure that its side-effects
+	     are evaluated before the call, so we evaluate its address.  */
 	  if (!is_true_formal_parm)
 	    {
-	      /* Make sure side-effects are evaluated before the call.  */
 	      if (TREE_SIDE_EFFECTS (gnu_name))
-		append_to_statement_list (gnu_name, &gnu_stmt_list);
+		{
+		  tree addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_name);
+		  append_to_statement_list (addr, &gnu_stmt_list);
+		}
 	      continue;
 	    }