trans.c (Identifier_to_gnu): Also handle deferred constants whose full view has discriminants specially.

* gcc-interface/trans.c (Identifier_to_gnu): Also handle deferred
	constants whose full view has discriminants specially.

From-SVN: r174689

gcc/ada/ChangeLog

@@ -1,3 +1,8 @@
+2011-06-06  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc-interface/trans.c (Identifier_to_gnu): Also handle deferred
+	constants whose full view has discriminants specially.
+
 2011-06-06  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gcc-interface/utils.c: Include diagnostic.h.

gcc/ada/gcc-interface/trans.c

@@ -906,9 +906,11 @@ Identifier_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p)
      attribute Position, generated for dispatching code (see Make_DT in
      exp_disp,adb). In that case we need the type itself, not is parent,
      in particular if it is a derived type  */
-  if (Is_Private_Type (gnat_temp_type)
-      && Has_Unknown_Discriminants (gnat_temp_type)
-      && Ekind (gnat_temp) == E_Constant
+  if (Ekind (gnat_temp) == E_Constant
+      && Is_Private_Type (gnat_temp_type)
+      && (Has_Unknown_Discriminants (gnat_temp_type)
+	  || (Present (Full_View (gnat_temp_type))
+ 	      && Has_Discriminants (Full_View (gnat_temp_type))))
       && Present (Full_View (gnat_temp)))
     {
       gnat_temp = Full_View (gnat_temp);

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2011-06-06  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/deferred_const4.ad[sb]: New test.
+	* gnat.dg/deferred_const4_pkg.ads: New helper.
+
 2011-06-06  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/test_tamdt.adb: Rename to...

gcc/testsuite/gnat.dg/deferred_const4.adb

@@ -0,0 +1,12 @@
+-- { dg-do compile }
+
+package body Deferred_Const4 is
+
+  function F return My_Q.T is
+    R : My_Q.T;
+  begin
+    R := My_Q.Null_T;
+    return R;
+  end;
+
+end Deferred_Const4;

gcc/testsuite/gnat.dg/deferred_const4.ads

@@ -0,0 +1,17 @@
+with Deferred_Const4_Pkg;
+
+package Deferred_Const4 is
+
+  type R1 is tagged record
+    I1 : Integer;
+  end record;
+
+  type R2 is new R1 with record
+    I2 : Integer;
+  end record;
+
+  package My_Q is new Deferred_Const4_Pkg (R2);
+
+  function F return My_Q.T;
+
+end Deferred_Const4;

gcc/testsuite/gnat.dg/deferred_const4_pkg.ads

@@ -0,0 +1,22 @@
+generic
+
+  type User_T is private;
+
+package Deferred_Const4_Pkg is
+
+  type T is private;
+
+  Null_T : constant T;
+
+private
+
+  type T (Valid : Boolean := False) is record
+    case Valid is
+      when True  => Value : User_T;
+      when False => null;
+    end case;
+  end record;
+
+  Null_T : constant T := (Valid => False);
+
+end Deferred_Const4_Pkg;