--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/switch-c.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,53 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+--                             S W I T C H - C                              --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 2001-2011, 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.  See the GNU General Public License --
+-- for  more details.  You should have  received  a copy of the GNU General --
+-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
+-- http://www.gnu.org/licenses for a complete copy of the license.          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This package scans front end switches. Note that the body of Usage must be
+--  be coordinated with the switches that are recognized by this package.
+
+--  The Usage package also acts as the official documentation for the switches
+--  that are recognized. In addition, package Debug documents the otherwise
+--  undocumented debug switches that are also recognized.
+
+with System.Strings; use System.Strings;
+
+package Switch.C is
+
+   procedure Scan_Front_End_Switches
+     (Switch_Chars : String;
+      Args         : String_List;
+      Arg_Rank     : Positive);
+   --  Procedures to scan out front end switches stored in the given string.
+   --  The first character is known to be a valid switch character, and there
+   --  are no blanks or other switch terminator characters in the string, so
+   --  the entire string should consist of valid switch characters, except that
+   --  an optional terminating NUL character is allowed. A bad switch causes
+   --  a fatal error exit and control does not return. The call also sets
+   --  Usage_Requested to True if a switch -gnath is encountered.
+   --
+   --  Args is the full list of command line arguments. Arg_Rank is the
+   --  position of the switch in Args. It is used for certain switches -gnatx
+   --  to check if a subsequent switch -gnat-x cancels the switch -gnatx.
+
+end Switch.C;