--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/a-chtgke.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,120 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT LIBRARY COMPONENTS                          --
+--                                                                          --
+--                 ADA.CONTAINERS.HASH_TABLES.GENERIC_KEYS                  --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 2004-2017, Free Software Foundation, Inc.         --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- This unit was originally developed by Matthew J Heaney.                  --
+------------------------------------------------------------------------------
+
+--  Hash_Table_Type is used to implement hashed containers. This package
+--  declares hash-table operations that depend on keys.
+
+generic
+   with package HT_Types is
+     new Generic_Hash_Table_Types (<>);
+
+   use HT_Types, HT_Types.Implementation;
+
+   with function Next (Node : Node_Access) return Node_Access;
+
+   with procedure Set_Next
+     (Node : Node_Access;
+      Next : Node_Access);
+
+   type Key_Type (<>) is limited private;
+
+   with function Hash (Key : Key_Type) return Hash_Type;
+
+   with function Equivalent_Keys
+     (Key  : Key_Type;
+      Node : Node_Access) return Boolean;
+
+package Ada.Containers.Hash_Tables.Generic_Keys is
+   pragma Preelaborate;
+
+   function Index
+     (HT  : Hash_Table_Type;
+      Key : Key_Type) return Hash_Type;
+   pragma Inline (Index);
+   --  Returns the bucket number (array index value) for the given key
+
+   function Checked_Index
+     (HT  : aliased in out Hash_Table_Type;
+      Key : Key_Type) return Hash_Type;
+   pragma Inline (Checked_Index);
+   --  Calls Index, but also locks and unlocks the container, per AI05-0022, in
+   --  order to detect element tampering by the generic actual Hash function.
+
+   function Checked_Equivalent_Keys
+     (HT   : aliased in out Hash_Table_Type;
+      Key  : Key_Type;
+      Node : Node_Access) return Boolean;
+   --  Calls Equivalent_Keys, but locks and unlocks the container, per
+   --  AI05-0022, in order to detect element tampering by that generic actual.
+
+   procedure Delete_Key_Sans_Free
+     (HT  : in out Hash_Table_Type;
+      Key : Key_Type;
+      X   : out Node_Access);
+   --  Removes the node (if any) with the given key from the hash table,
+   --  without deallocating it. Program_Error is raised if the hash
+   --  table is busy.
+
+   function Find
+     (HT  : aliased in out Hash_Table_Type;
+      Key : Key_Type) return Node_Access;
+   --  Returns the node (if any) corresponding to the given key
+
+   generic
+      with function New_Node (Next : Node_Access) return Node_Access;
+   procedure Generic_Conditional_Insert
+     (HT       : in out Hash_Table_Type;
+      Key      : Key_Type;
+      Node     : out Node_Access;
+      Inserted : out Boolean);
+   --  Attempts to insert a new node with the given key into the hash table.
+   --  If a node with that key already exists in the table, then that node
+   --  is returned and Inserted returns False. Otherwise New_Node is called
+   --  to allocate a new node, and Inserted returns True. Program_Error is
+   --  raised if the hash table is busy.
+
+   generic
+      with function Hash (Node : Node_Access) return Hash_Type;
+      with procedure Assign (Node : Node_Access; Key : Key_Type);
+   procedure Generic_Replace_Element
+     (HT   : in out Hash_Table_Type;
+      Node : Node_Access;
+      Key  : Key_Type);
+   --  Assigns Key to Node, possibly changing its equivalence class. If Node
+   --  is in the same equivalence class as Key (that is, it's already in the
+   --  bucket implied by Key), then if the hash table is locked then
+   --  Program_Error is raised; otherwise Assign is called to assign Key to
+   --  Node. If Node is in a different bucket from Key, then Program_Error is
+   --  raised if the hash table is busy. Otherwise it Assigns Key to Node and
+   --  moves the Node from its current bucket to the bucket implied by Key.
+   --  Note that it is never proper to assign to Node a key value already
+   --  in the map, and so if Key is equivalent to some other node then
+   --  Program_Error is raised.
+
+end Ada.Containers.Hash_Tables.Generic_Keys;