--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnarl/g-signal.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,52 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT RUN-TIME COMPONENTS                         --
+--                                                                          --
+--                         G N A T . S I G N A L S                          --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 2003-2017, 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.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This package provides operations for querying and setting the blocked
+--  status of signals.
+
+--  This package is supported only on targets where Ada.Interrupts.Interrupt_ID
+--  corresponds to software signals on the target, and where System.Interrupts
+--  provides the ability to block and unblock signals.
+
+with Ada.Interrupts;
+
+package GNAT.Signals is
+
+   procedure Block_Signal (Signal : Ada.Interrupts.Interrupt_ID);
+   --  Block "Signal" at the process level
+
+   procedure Unblock_Signal (Signal : Ada.Interrupts.Interrupt_ID);
+   --  Unblock "Signal" at the process level
+
+   function Is_Blocked (Signal : Ada.Interrupts.Interrupt_ID) return Boolean;
+   --  "Signal" blocked at the process level?
+
+end GNAT.Signals;