--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/s-conca3.adb	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,78 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
+--                                                                          --
+--                      S Y S T E M . C O N C A T _ 3                       --
+--                                                                          --
+--                                 B o d y                                  --
+--                                                                          --
+--            Copyright (C) 2008-2017, 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/>.                                          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+pragma Compiler_Unit_Warning;
+
+with System.Concat_2;
+
+package body System.Concat_3 is
+
+   pragma Suppress (All_Checks);
+
+   ------------------
+   -- Str_Concat_3 --
+   ------------------
+
+   procedure Str_Concat_3 (R : out String; S1, S2, S3 : String) is
+      F, L : Natural;
+
+   begin
+      F := R'First;
+      L := F + S1'Length - 1;
+      R (F .. L) := S1;
+
+      F := L + 1;
+      L := F + S2'Length - 1;
+      R (F .. L) := S2;
+
+      F := L + 1;
+      L := R'Last;
+      R (F .. L) := S3;
+   end Str_Concat_3;
+
+   -------------------------
+   -- Str_Concat_Bounds_3 --
+   -------------------------
+
+   procedure Str_Concat_Bounds_3
+     (Lo, Hi     : out Natural;
+      S1, S2, S3 : String)
+   is
+   begin
+      System.Concat_2.Str_Concat_Bounds_2 (Lo, Hi, S2, S3);
+
+      if S1 /= "" then
+         Hi := S1'Last + Hi - Lo + 1;
+         Lo := S1'First;
+      end if;
+   end Str_Concat_Bounds_3;
+
+end System.Concat_3;