1 files changed, 27 insertions, 24 deletions

diff --git a/gcc/ada/a-ciorse.ads b/gcc/ada/a-ciorse.ads
index c885b80478e..e0e95ede1b3 100644
--- a/gcc/ada/a-ciorse.ads
+++ b/gcc/ada/a-ciorse.ads
@@ -33,6 +33,7 @@
 
 with Ada.Iterator_Interfaces;
 
+private with Ada.Containers.Helpers;
 private with Ada.Containers.Red_Black_Trees;
 private with Ada.Finalization;
 private with Ada.Streams;
@@ -298,17 +299,16 @@ package Ada.Containers.Indefinite_Ordered_Sets is
 
       type Key_Access is access all Key_Type;
 
+      package Impl is new Helpers.Generic_Implementation;
+
       type Reference_Control_Type is
-        new Ada.Finalization.Controlled with
+        new Impl.Reference_Control_Type with
       record
          Container : Set_Access;
          Pos       : Cursor;
          Old_Key   : Key_Access;
       end record;
 
-      overriding procedure Adjust (Control : in out Reference_Control_Type);
-      pragma Inline (Adjust);
-
       overriding procedure Finalize (Control : in out Reference_Control_Type);
       pragma Inline (Finalize);
 
@@ -338,7 +338,7 @@ private
    type Node_Type;
    type Node_Access is access Node_Type;
 
-   type Element_Access is access Element_Type;
+   type Element_Access is access all Element_Type;
 
    type Node_Type is limited record
       Parent  : Node_Access;
@@ -361,7 +361,7 @@ private
    overriding procedure Finalize (Container : in out Set) renames Clear;
 
    use Red_Black_Trees;
-   use Tree_Types;
+   use Tree_Types, Tree_Types.Implementation;
    use Ada.Finalization;
    use Ada.Streams;
 
@@ -397,16 +397,8 @@ private
 
    for Cursor'Read use Read;
 
-   type Reference_Control_Type is
-      new Controlled with record
-         Container : Set_Access;
-      end record;
-
-   overriding procedure Adjust (Control : in out Reference_Control_Type);
-   pragma Inline (Adjust);
-
-   overriding procedure Finalize (Control : in out Reference_Control_Type);
-   pragma Inline (Finalize);
+   subtype Reference_Control_Type is Implementation.Reference_Control_Type;
+   --  It is necessary to rename this here, so that the compiler can find it
 
    type Constant_Reference_Type
      (Element : not null access constant Element_Type) is
@@ -430,13 +422,23 @@ private
 
    for Constant_Reference_Type'Write use Write;
 
-   Empty_Set : constant Set :=
-                 (Controlled with Tree => (First  => null,
-                                           Last   => null,
-                                           Root   => null,
-                                           Length => 0,
-                                           Busy   => 0,
-                                           Lock   => 0));
+   --  Three operations are used to optimize in the expansion of "for ... of"
+   --  loops: the Next(Cursor) procedure in the visible part, and the following
+   --  Pseudo_Reference and Get_Element_Access functions. See Sem_Ch5 for
+   --  details.
+
+   function Pseudo_Reference
+     (Container : aliased Set'Class) return Reference_Control_Type;
+   pragma Inline (Pseudo_Reference);
+   --  Creates an object of type Reference_Control_Type pointing to the
+   --  container, and increments the Lock. Finalization of this object will
+   --  decrement the Lock.
+
+   function Get_Element_Access
+     (Position : Cursor) return not null Element_Access;
+   --  Returns a pointer to the element designated by Position.
+
+   Empty_Set : constant Set := (Controlled with others => <>);
 
    No_Element : constant Cursor := Cursor'(null, null);
 
@@ -445,7 +447,8 @@ private
    record
       Container : Set_Access;
       Node      : Node_Access;
-   end record;
+   end record
+     with Disable_Controlled => not T_Check;
 
    overriding procedure Finalize (Object : in out Iterator);