decl.c (gnat_to_gnu_entity): Adjust call to components_to_record.

	* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Record_Type>: Adjust
	call to components_to_record.
	(components_to_record): Add FIRST_FREE_POS parameter.  For the variant
	part, reuse enclosing union even if there is a representation clause
	on the Unchecked_Union.  If there is a variant part, compute the new
	first free position, if any.  Adjust call to self.  Use a single field
	directly only if it hasn't got a representation clause or is placed at
	offset zero.  Create the variant part at offset 0 if all the fields
	down to this level have a rep clause.  Do not chain the variant part
	immediately and adjust downstream.
	Do not test ALL_REP before moving the fields without rep clause to the
	previous level.  Call create_rep_part to create the REP part and force
	a minimum size on it if necessary.  Do not chain it immediately.
	Create a fake REP part if there are fields without rep clause that need
	to be laid out starting from FIRST_FREE_POS.
	At the end, chain the REP part and then the variant part.
	(create_rep_part): New function.
	(get_rep_part): Minor tweak.
	* gcc-interface/utils.c (tree_code_for_record_type): Minor tweak.

From-SVN: r181526

gcc/ada/ChangeLog

+2011-11-20  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Record_Type>: Adjust
+	call to components_to_record.
+	(components_to_record): Add FIRST_FREE_POS parameter.  For the variant
+	part, reuse enclosing union even if there is a representation clause
+	on the Unchecked_Union.  If there is a variant part, compute the new
+	first free position, if any.  Adjust call to self.  Use a single field
+	directly only if it hasn't got a representation clause or is placed at
+	offset zero.  Create the variant part at offset 0 if all the fields
+	down to this level have a rep clause.  Do not chain the variant part
+	immediately and adjust downstream.
+	Do not test ALL_REP before moving the fields without rep clause to the
+	previous level.  Call create_rep_part to create the REP part and force
+	a minimum size on it if necessary.  Do not chain it immediately.
+	Create a fake REP part if there are fields without rep clause that need
+	to be laid out starting from FIRST_FREE_POS.
+	At the end, chain the REP part and then the variant part.
+	(create_rep_part): New function.
+	(get_rep_part): Minor tweak.
+	* gcc-interface/utils.c (tree_code_for_record_type): Minor tweak.
+
 2011-11-18  Iain Sandoe  <iains@gcc.gnu.org>
 
 	PR target/50678

gcc/ada/gcc-interface/utils.c

@@ -4744,19 +4744,17 @@ unchecked_convert (tree type, tree expr, bool notrunc_p)
 enum tree_code
 tree_code_for_record_type (Entity_Id gnat_type)
 {
-  Node_Id component_list
-    = Component_List (Type_Definition
-		      (Declaration_Node
-		       (Implementation_Base_Type (gnat_type))));
-  Node_Id component;
-
- /* Make this a UNION_TYPE unless it's either not an Unchecked_Union or
-    we have a non-discriminant field outside a variant.  In either case,
-    it's a RECORD_TYPE.  */
+  Node_Id component_list, component;
 
+  /* Return UNION_TYPE if it's an Unchecked_Union whose non-discriminant
+     fields are all in the variant part.  Otherwise, return RECORD_TYPE.  */
   if (!Is_Unchecked_Union (gnat_type))
     return RECORD_TYPE;
 
+  gnat_type = Implementation_Base_Type (gnat_type);
+  component_list
+    = Component_List (Type_Definition (Declaration_Node (gnat_type)));
+
   for (component = First_Non_Pragma (Component_Items (component_list));
        Present (component);
        component = Next_Non_Pragma (component))

gcc/testsuite/ChangeLog

+2011-11-20  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/discr32.adb: New test.
+	* gnat.dg/discr32_pkg.ads: New helper.
+
 2011-11-20  Nathan Sidwell  <nathan@acm.org>
 
 	PR gcov-profile/51113

gcc/testsuite/gnat.dg/discr32.adb

+-- { dg-do run }
+-- { dg-options "-gnatws" }
+
+with Discr32_Pkg; use Discr32_Pkg;
+
+procedure Discr32 is
+begin
+
+  if R1'Object_Size /= 32 then
+    raise Program_Error;
+  end if;
+
+  if R2'Object_Size /= R'Object_Size then
+    raise Program_Error;
+  end if;
+
+  if R3'Object_Size /= 64 then
+    raise Program_Error;
+  end if;
+
+end;

gcc/testsuite/gnat.dg/discr32_pkg.ads

+package Discr32_Pkg is
+
+  type Enum is (One, Two, Three);
+
+  type R (D : Enum) is record
+    case D is
+      when One   => B : Boolean;
+      when Two   => I : Integer;
+      when Three => F : Float;
+    end case;
+  end record;
+
+  for R use record
+     D at 0 range 0 .. 1;
+     B at 1 range 0 .. 0;
+     I at 4 range 0 .. 31 + 128;
+--     F at 4 range 0 .. 31;
+  end record;
+
+  subtype R1 is R (One);
+  subtype R2 is R (Two);
+  subtype R3 is R (Three);
+
+end Discr32_Pkg;