--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/s-valrea.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,74 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+--                      S Y S T E M . V A L _ R E A L                       --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 1992-2017, 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.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+package System.Val_Real is
+   pragma Pure;
+
+   function Scan_Real
+     (Str : String;
+      Ptr : not null access Integer;
+      Max : Integer) return Long_Long_Float;
+   --  This function scans the string starting at Str (Ptr.all) for a valid
+   --  real literal according to the syntax described in (RM 3.5(43)). The
+   --  substring scanned extends no further than Str (Max). There are three
+   --  cases for the return:
+   --
+   --  If a valid real is found after scanning past any initial spaces, then
+   --  Ptr.all is updated past the last character of the real (but trailing
+   --  spaces are not scanned out).
+   --
+   --  If no valid real is found, then Ptr.all points either to an initial
+   --  non-blank character, or to Max + 1 if the field is all spaces and the
+   --  exception Constraint_Error is raised.
+   --
+   --  If a syntactically valid real is scanned, but the value is out of
+   --  range, or, in the based case, the base value is out of range or there
+   --  is an out of range digit, then Ptr.all points past the real literal,
+   --  and Constraint_Error is raised.
+   --
+   --  Note: these rules correspond to the requirements for leaving the
+   --  pointer positioned in Text_Io.Get
+   --
+   --  Note: if Str is null, i.e. if Max is less than Ptr, then this is a
+   --  special case of an all-blank string, and Ptr is unchanged, and hence
+   --  is greater than Max as required in this case.
+   --
+   --  Note: this routine should not be called with Str'Last = Positive'Last.
+   --  If this occurs Program_Error is raised with a message noting that this
+   --  case is not supported. Most such cases are eliminated by the caller.
+
+   function Value_Real (Str : String) return Long_Long_Float;
+   --  Used in computing X'Value (Str) where X is a floating-point type or an
+   --  ordinary fixed-point type. Str is the string argument of the attribute.
+   --  Constraint_Error is raised if the string is malformed, or if the value
+   --  out of range of Long_Long_Float.
+
+end System.Val_Real;