a-cohase.ads, [...]: Update to latest RM version.

2011-12-22  Ed Schonberg  <schonberg@adacore.com>

	* a-cohase.ads, a-cohase.adb: Update to latest RM version. Add
	aspect Constant_Reference to set type, and corresponding
	functions.
	* a-cihama.ads, a-cihama.adb: Update to latest RM version. Add
	function Reference to provide a proper element iterator construct
	over indefinite maps.

2011-12-22  Ed Schonberg  <schonberg@adacore.com>

	* exp_attr.adb (Expand_N_Attribute, case 'Access): Do not insert
	implicit conversion on prefix of Unrestricted_Access when prefix
	is an explicit dereference.

From-SVN: r182617

gcc/ada/ChangeLog

+2011-12-22  Ed Schonberg  <schonberg@adacore.com>
+
+	* a-cohase.ads, a-cohase.adb: Update to latest RM version. Add
+	aspect Constant_Reference to set type, and corresponding
+	functions.
+	* a-cihama.ads, a-cihama.adb: Update to latest RM version. Add
+	function Reference to provide a proper element iterator construct
+	over indefinite maps.
+
+2011-12-22  Ed Schonberg  <schonberg@adacore.com>
+
+	* exp_attr.adb (Expand_N_Attribute, case 'Access): Do not insert
+	implicit conversion on prefix of Unrestricted_Access when prefix
+	is an explicit dereference.
+
 2011-12-22  Vincent Pucci  <pucci@adacore.com>
 
 	* sem_dim.adb: Addressed all ??? comments. Replacement of warnings by

gcc/ada/a-cihama.adb

@@ -973,6 +973,15 @@ package body Ada.Containers.Indefinite_Hashed_Maps is
          Container.Find (Key).Node.Element.all'Unrestricted_Access);
    end Reference;
 
+   function Reference
+     (Container : aliased in out Map;
+      Position  : Cursor) return Reference_Type
+   is
+      pragma Unreferenced (Container);
+   begin
+      return (Element => Element (Position)'Unrestricted_Access);
+   end Reference;
+
    -------------
    -- Replace --
    -------------

gcc/ada/a-cihama.ads

@@ -293,8 +293,13 @@ package Ada.Containers.Indefinite_Hashed_Maps is
       Key       : Key_Type)    --  SHOULD BE ALIASED ???
       return Constant_Reference_Type;
 
-   function Reference (Container : Map; Key : Key_Type)
-   return Reference_Type;
+   function Reference
+     (Container : Map;
+      Key       : Key_Type) return Reference_Type;
+
+   function Reference
+     (Container : aliased in out Map;
+      Position  : Cursor) return Reference_Type;
 
    procedure Iterate
      (Container : Map;

gcc/ada/a-cohase.adb

@@ -1100,6 +1100,14 @@ package body Ada.Containers.Hashed_Sets is
       raise Program_Error with "attempt to stream set cursor";
    end Read;
 
+   procedure Read
+     (Stream : not null access Root_Stream_Type'Class;
+      Item   : out Constant_Reference_Type)
+   is
+   begin
+      raise Program_Error with "attempt to stream reference";
+   end Read;
+
    ---------------
    -- Read_Node --
    ---------------
@@ -1118,6 +1126,19 @@ package body Ada.Containers.Hashed_Sets is
          raise;
    end Read_Node;
 
+   ---------------
+   -- Reference --
+   ---------------
+
+   function Constant_Reference
+     (Container : aliased Set;
+      Position  : Cursor) return Constant_Reference_Type
+   is
+      pragma Unreferenced (Container);
+   begin
+      return (Element => Position.Node.Element'Unrestricted_Access);
+   end Constant_Reference;
+
    -------------
    -- Replace --
    -------------
@@ -1655,6 +1676,14 @@ package body Ada.Containers.Hashed_Sets is
       raise Program_Error with "attempt to stream set cursor";
    end Write;
 
+   procedure Write
+     (Stream : not null access Root_Stream_Type'Class;
+      Item   : Constant_Reference_Type)
+   is
+   begin
+      raise Program_Error with "attempt to stream reference";
+   end Write;
+
    ----------------
    -- Write_Node --
    ----------------
@@ -1923,6 +1952,27 @@ package body Ada.Containers.Hashed_Sets is
          raise Program_Error with "key was modified";
       end Update_Element_Preserving_Key;
 
+      ------------------------------
+      -- Reference_Preserving_Key --
+      ------------------------------
+
+      function Reference_Preserving_Key
+        (Container : aliased in out Set;
+         Position  : Cursor) return Reference_Type
+      is
+         pragma Unreferenced (Container);
+      begin
+         return (Element => Position.Node.Element'Unrestricted_Access);
+      end Reference_Preserving_Key;
+
+      function Reference_Preserving_Key
+        (Container : aliased in out Set;
+         Key       : Key_Type) return Reference_Type
+      is
+         Position : constant Cursor := Find (Container, Key);
+      begin
+         return (Element => Position.Node.Element'Unrestricted_Access);
+      end Reference_Preserving_Key;
    end Generic_Keys;
 
 end Ada.Containers.Hashed_Sets;

gcc/ada/a-cohase.ads

@@ -31,10 +31,10 @@
 -- This unit was originally developed by Matthew J Heaney.                  --
 ------------------------------------------------------------------------------
 
+with Ada.Iterator_Interfaces;
 private with Ada.Containers.Hash_Tables;
 private with Ada.Streams;
 private with Ada.Finalization;
-with Ada.Iterator_Interfaces;
 
 generic
    type Element_Type is private;
@@ -52,6 +52,7 @@ package Ada.Containers.Hashed_Sets is
 
    type Set is tagged private
    with
+      constant_Indexing => Constant_Reference,
       Default_Iterator  => Iterate,
       Iterator_Element  => Element_Type;
 
@@ -148,6 +149,14 @@ package Ada.Containers.Hashed_Sets is
 
    function Copy (Source : Set; Capacity : Count_Type := 0) return Set;
 
+   type Constant_Reference_Type
+     (Element : not null access constant Element_Type) is private
+        with Implicit_Dereference => Element;
+
+   function Constant_Reference
+     (Container : aliased Set;
+      Position  : Cursor) return Constant_Reference_Type;
+
    procedure Move (Target : in out Set; Source : in out Set);
    --  Clears Target (if it's not empty), and then moves (not copies) the
    --  buckets array and nodes from Source to Target.
@@ -403,13 +412,27 @@ package Ada.Containers.Hashed_Sets is
       --  Equivalent_Keys to compare the saved key-value to the value returned
       --  by applying generic formal operation Key to the post-Process value of
       --  element. If the key values compare equal then the operation
-      --  completes. Otherwise, the node is removed from the map and
+      --  completes. Otherwise, the node is removed from the set and
       --  Program_Error is raised.
 
+      type Reference_Type (Element : not null access Element_Type) is private
+        with Implicit_Dereference => Element;
+
+      function Reference_Preserving_Key
+        (Container : aliased in out Set;
+         Position  : Cursor) return Reference_Type;
+
+      function Reference_Preserving_Key
+        (Container : aliased in out Set;
+         Key  : Key_Type) return Reference_Type;
+
+   private
+      type Reference_Type (Element : not null access Element_Type)
+         is null record;
+
    end Generic_Keys;
 
 private
-
    pragma Inline (Next);
 
    type Node_Type;
@@ -469,6 +492,21 @@ private
 
    for Set'Read use Read;
 
+   type Constant_Reference_Type
+     (Element : not null access constant Element_Type) is null record;
+
+   procedure Read
+     (Stream : not null access Root_Stream_Type'Class;
+      Item   : out Constant_Reference_Type);
+
+   for Constant_Reference_Type'Read use Read;
+
+   procedure Write
+     (Stream : not null access Root_Stream_Type'Class;
+      Item   : Constant_Reference_Type);
+
+   for Constant_Reference_Type'Write use Write;
+
    Empty_Set : constant Set := (Controlled with HT => (null, 0, 0, 0));
 
 end Ada.Containers.Hashed_Sets;

gcc/ada/exp_attr.adb

@@ -971,11 +971,12 @@ package body Exp_Attr is
                                      (Etype (Prefix (Ref_Object))));
                   begin
                      --  No implicit conversion required if designated types
-                     --  match.
+                     --  match, or if we have an unrestricted access.
 
                      if Obj_DDT /= Btyp_DDT
+                       and then Id /= Attribute_Unrestricted_Access
                        and then not (Is_Class_Wide_Type (Obj_DDT)
-                                       and then Etype (Obj_DDT) = Btyp_DDT)
+                                      and then Etype (Obj_DDT) = Btyp_DDT)
                      then
                         Rewrite (N,
                           Convert_To (Typ,