--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/a-strunb__shared.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,490 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT RUN-TIME COMPONENTS                         --
+--                                                                          --
+--                 A D A . S T R I N G S . U N B O U N D E D                --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 1992-2017, Free Software Foundation, Inc.         --
+--                                                                          --
+-- This specification is derived from the Ada Reference Manual for use with --
+-- GNAT. The copyright notice above, and the license provisions that follow --
+-- apply solely to the  contents of the part following the private keyword. --
+--                                                                          --
+-- 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/>.                                          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This package provides an implementation of Ada.Strings.Unbounded that uses
+--  reference counts to implement copy on modification (rather than copy on
+--  assignment). This is significantly more efficient on many targets.
+
+--  This version is supported on:
+--    - all Alpha platforms
+--    - all ia64 platforms
+--    - all PowerPC platforms
+--    - all SPARC V9 platforms
+--    - all x86 platforms
+--    - all x86_64 platforms
+
+   --  This package uses several techniques to increase speed:
+
+   --   - Implicit sharing or copy-on-write. An Unbounded_String contains only
+   --     the reference to the data which is shared between several instances.
+   --     The shared data is reallocated only when its value is changed and
+   --     the object mutation can't be used or it is inefficient to use it.
+
+   --   - Object mutation. Shared data object can be reused without memory
+   --     reallocation when all of the following requirements are met:
+   --      - the shared data object is no longer used by anyone else;
+   --      - the size is sufficient to store the new value;
+   --      - the gap after reuse is less than a defined threshold.
+
+   --   - Memory preallocation. Most of used memory allocation algorithms
+   --     align allocated segments on the some boundary, thus some amount of
+   --     additional memory can be preallocated without any impact. Such
+   --     preallocated memory can used later by Append/Insert operations
+   --     without reallocation.
+
+   --  Reference counting uses GCC builtin atomic operations, which allows safe
+   --  sharing of internal data between Ada tasks. Nevertheless, this does not
+   --  make objects of Unbounded_String thread-safe: an instance cannot be
+   --  accessed by several tasks simultaneously.
+
+with Ada.Strings.Maps;
+private with Ada.Finalization;
+private with System.Atomic_Counters;
+
+package Ada.Strings.Unbounded is
+   pragma Preelaborate;
+
+   type Unbounded_String is private;
+   pragma Preelaborable_Initialization (Unbounded_String);
+
+   Null_Unbounded_String : constant Unbounded_String;
+
+   function Length (Source : Unbounded_String) return Natural;
+
+   type String_Access is access all String;
+
+   procedure Free (X : in out String_Access);
+
+   --------------------------------------------------------
+   -- Conversion, Concatenation, and Selection Functions --
+   --------------------------------------------------------
+
+   function To_Unbounded_String
+     (Source : String)  return Unbounded_String;
+
+   function To_Unbounded_String
+     (Length : Natural) return Unbounded_String;
+
+   function To_String (Source : Unbounded_String) return String;
+
+   procedure Set_Unbounded_String
+     (Target : out Unbounded_String;
+      Source : String);
+   pragma Ada_05 (Set_Unbounded_String);
+
+   procedure Append
+     (Source   : in out Unbounded_String;
+      New_Item : Unbounded_String);
+
+   procedure Append
+     (Source   : in out Unbounded_String;
+      New_Item : String);
+
+   procedure Append
+     (Source   : in out Unbounded_String;
+      New_Item : Character);
+
+   function "&"
+     (Left  : Unbounded_String;
+      Right : Unbounded_String) return Unbounded_String;
+
+   function "&"
+     (Left  : Unbounded_String;
+      Right : String) return Unbounded_String;
+
+   function "&"
+     (Left  : String;
+      Right : Unbounded_String) return Unbounded_String;
+
+   function "&"
+     (Left  : Unbounded_String;
+      Right : Character) return Unbounded_String;
+
+   function "&"
+     (Left  : Character;
+      Right : Unbounded_String) return Unbounded_String;
+
+   function Element
+     (Source : Unbounded_String;
+      Index  : Positive) return Character;
+
+   procedure Replace_Element
+     (Source : in out Unbounded_String;
+      Index  : Positive;
+      By     : Character);
+
+   function Slice
+     (Source : Unbounded_String;
+      Low    : Positive;
+      High   : Natural) return String;
+
+   function Unbounded_Slice
+     (Source : Unbounded_String;
+      Low    : Positive;
+      High   : Natural) return Unbounded_String;
+   pragma Ada_05 (Unbounded_Slice);
+
+   procedure Unbounded_Slice
+     (Source : Unbounded_String;
+      Target : out Unbounded_String;
+      Low    : Positive;
+      High   : Natural);
+   pragma Ada_05 (Unbounded_Slice);
+
+   function "="
+     (Left  : Unbounded_String;
+      Right : Unbounded_String) return Boolean;
+
+   function "="
+     (Left  : Unbounded_String;
+      Right : String) return Boolean;
+
+   function "="
+     (Left  : String;
+      Right : Unbounded_String) return Boolean;
+
+   function "<"
+     (Left  : Unbounded_String;
+      Right : Unbounded_String) return Boolean;
+
+   function "<"
+     (Left  : Unbounded_String;
+      Right : String) return Boolean;
+
+   function "<"
+     (Left  : String;
+      Right : Unbounded_String) return Boolean;
+
+   function "<="
+     (Left  : Unbounded_String;
+      Right : Unbounded_String) return Boolean;
+
+   function "<="
+     (Left  : Unbounded_String;
+      Right : String) return Boolean;
+
+   function "<="
+     (Left  : String;
+      Right : Unbounded_String) return Boolean;
+
+   function ">"
+     (Left  : Unbounded_String;
+      Right : Unbounded_String) return Boolean;
+
+   function ">"
+     (Left  : Unbounded_String;
+      Right : String) return Boolean;
+
+   function ">"
+     (Left  : String;
+      Right : Unbounded_String) return Boolean;
+
+   function ">="
+     (Left  : Unbounded_String;
+      Right : Unbounded_String) return Boolean;
+
+   function ">="
+     (Left  : Unbounded_String;
+      Right : String) return Boolean;
+
+   function ">="
+     (Left  : String;
+      Right : Unbounded_String) return Boolean;
+
+   ------------------------
+   -- Search Subprograms --
+   ------------------------
+
+   function Index
+     (Source  : Unbounded_String;
+      Pattern : String;
+      Going   : Direction := Forward;
+      Mapping : Maps.Character_Mapping := Maps.Identity) return Natural;
+
+   function Index
+     (Source  : Unbounded_String;
+      Pattern : String;
+      Going   : Direction := Forward;
+      Mapping : Maps.Character_Mapping_Function) return Natural;
+
+   function Index
+     (Source : Unbounded_String;
+      Set    : Maps.Character_Set;
+      Test   : Membership := Inside;
+      Going  : Direction  := Forward) return Natural;
+
+   function Index
+     (Source  : Unbounded_String;
+      Pattern : String;
+      From    : Positive;
+      Going   : Direction := Forward;
+      Mapping : Maps.Character_Mapping := Maps.Identity) return Natural;
+   pragma Ada_05 (Index);
+
+   function Index
+     (Source  : Unbounded_String;
+      Pattern : String;
+      From    : Positive;
+      Going   : Direction := Forward;
+      Mapping : Maps.Character_Mapping_Function) return Natural;
+   pragma Ada_05 (Index);
+
+   function Index
+     (Source  : Unbounded_String;
+      Set     : Maps.Character_Set;
+      From    : Positive;
+      Test    : Membership := Inside;
+      Going   : Direction := Forward) return Natural;
+   pragma Ada_05 (Index);
+
+   function Index_Non_Blank
+     (Source : Unbounded_String;
+      Going  : Direction := Forward) return Natural;
+
+   function Index_Non_Blank
+     (Source : Unbounded_String;
+      From   : Positive;
+      Going  : Direction := Forward) return Natural;
+   pragma Ada_05 (Index_Non_Blank);
+
+   function Count
+     (Source  : Unbounded_String;
+      Pattern : String;
+      Mapping : Maps.Character_Mapping := Maps.Identity) return Natural;
+
+   function Count
+     (Source  : Unbounded_String;
+      Pattern : String;
+      Mapping : Maps.Character_Mapping_Function) return Natural;
+
+   function Count
+     (Source : Unbounded_String;
+      Set    : Maps.Character_Set) return Natural;
+
+   procedure Find_Token
+     (Source : Unbounded_String;
+      Set    : Maps.Character_Set;
+      From   : Positive;
+      Test   : Membership;
+      First  : out Positive;
+      Last   : out Natural);
+   pragma Ada_2012 (Find_Token);
+
+   procedure Find_Token
+     (Source : Unbounded_String;
+      Set    : Maps.Character_Set;
+      Test   : Membership;
+      First  : out Positive;
+      Last   : out Natural);
+
+   ------------------------------------
+   -- String Translation Subprograms --
+   ------------------------------------
+
+   function Translate
+     (Source  : Unbounded_String;
+      Mapping : Maps.Character_Mapping) return Unbounded_String;
+
+   procedure Translate
+     (Source  : in out Unbounded_String;
+      Mapping : Maps.Character_Mapping);
+
+   function Translate
+     (Source  : Unbounded_String;
+      Mapping : Maps.Character_Mapping_Function) return Unbounded_String;
+
+   procedure Translate
+     (Source  : in out Unbounded_String;
+      Mapping : Maps.Character_Mapping_Function);
+
+   ---------------------------------------
+   -- String Transformation Subprograms --
+   ---------------------------------------
+
+   function Replace_Slice
+     (Source : Unbounded_String;
+      Low    : Positive;
+      High   : Natural;
+      By     : String) return Unbounded_String;
+
+   procedure Replace_Slice
+     (Source : in out Unbounded_String;
+      Low    : Positive;
+      High   : Natural;
+      By     : String);
+
+   function Insert
+     (Source   : Unbounded_String;
+      Before   : Positive;
+      New_Item : String) return Unbounded_String;
+
+   procedure Insert
+     (Source   : in out Unbounded_String;
+      Before   : Positive;
+      New_Item : String);
+
+   function Overwrite
+     (Source   : Unbounded_String;
+      Position : Positive;
+      New_Item : String) return Unbounded_String;
+
+   procedure Overwrite
+     (Source   : in out Unbounded_String;
+      Position : Positive;
+      New_Item : String);
+
+   function Delete
+     (Source  : Unbounded_String;
+      From    : Positive;
+      Through : Natural) return Unbounded_String;
+
+   procedure Delete
+     (Source  : in out Unbounded_String;
+      From    : Positive;
+      Through : Natural);
+
+   function Trim
+     (Source : Unbounded_String;
+      Side   : Trim_End) return Unbounded_String;
+
+   procedure Trim
+     (Source : in out Unbounded_String;
+      Side   : Trim_End);
+
+   function Trim
+     (Source : Unbounded_String;
+      Left   : Maps.Character_Set;
+      Right  : Maps.Character_Set) return Unbounded_String;
+
+   procedure Trim
+     (Source : in out Unbounded_String;
+      Left   : Maps.Character_Set;
+      Right  : Maps.Character_Set);
+
+   function Head
+     (Source : Unbounded_String;
+      Count  : Natural;
+      Pad    : Character := Space) return Unbounded_String;
+
+   procedure Head
+     (Source : in out Unbounded_String;
+      Count  : Natural;
+      Pad    : Character := Space);
+
+   function Tail
+     (Source : Unbounded_String;
+      Count  : Natural;
+      Pad    : Character := Space) return Unbounded_String;
+
+   procedure Tail
+     (Source : in out Unbounded_String;
+      Count  : Natural;
+      Pad    : Character := Space);
+
+   function "*"
+     (Left  : Natural;
+      Right : Character) return Unbounded_String;
+
+   function "*"
+     (Left  : Natural;
+      Right : String) return Unbounded_String;
+
+   function "*"
+     (Left  : Natural;
+      Right : Unbounded_String) return Unbounded_String;
+
+private
+   pragma Inline (Length);
+
+   package AF renames Ada.Finalization;
+
+   type Shared_String (Max_Length : Natural) is limited record
+      Counter : System.Atomic_Counters.Atomic_Counter;
+      --  Reference counter
+
+      Last : Natural := 0;
+      Data : String (1 .. Max_Length);
+      --  Last is the index of last significant element of the Data. All
+      --  elements with larger indexes are currently insignificant.
+   end record;
+
+   type Shared_String_Access is access all Shared_String;
+
+   procedure Reference (Item : not null Shared_String_Access);
+   --  Increment reference counter
+
+   procedure Unreference (Item : not null Shared_String_Access);
+   --  Decrement reference counter, deallocate Item when counter goes to zero
+
+   function Can_Be_Reused
+     (Item   : not null Shared_String_Access;
+      Length : Natural) return Boolean;
+   --  Returns True if Shared_String can be reused. There are two criteria when
+   --  Shared_String can be reused: its reference counter must be one (thus
+   --  Shared_String is owned exclusively) and its size is sufficient to
+   --  store string with specified length effectively.
+
+   function Allocate
+     (Max_Length : Natural) return not null Shared_String_Access;
+   --  Allocates new Shared_String with at least specified maximum length.
+   --  Actual maximum length of the allocated Shared_String can be slightly
+   --  greater. Returns reference to Empty_Shared_String when requested length
+   --  is zero.
+
+   Empty_Shared_String : aliased Shared_String (0);
+
+   function To_Unbounded (S : String) return Unbounded_String
+     renames To_Unbounded_String;
+   --  This renames are here only to be used in the pragma Stream_Convert
+
+   type Unbounded_String is new AF.Controlled with record
+      Reference : not null Shared_String_Access := Empty_Shared_String'Access;
+   end record;
+
+   pragma Stream_Convert (Unbounded_String, To_Unbounded, To_String);
+   --  Provide stream routines without dragging in Ada.Streams
+
+   pragma Finalize_Storage_Only (Unbounded_String);
+   --  Finalization is required only for freeing storage
+
+   overriding procedure Initialize (Object : in out Unbounded_String);
+   overriding procedure Adjust     (Object : in out Unbounded_String);
+   overriding procedure Finalize   (Object : in out Unbounded_String);
+
+   Null_Unbounded_String : constant Unbounded_String :=
+                             (AF.Controlled with
+                                Reference => Empty_Shared_String'Access);
+
+end Ada.Strings.Unbounded;