Package Name: system

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------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                               S Y S T E M                                --
--                                                                          --
--                                 S p e c                                  --
--                                                                          --
--                            $Revision: 1.28 $                             --
--                                                                          --
-- This specification is adapted from the Ada Reference Manual for use with --
-- GNAT.  In accordance with the copyright of that document, you can freely --
-- copy and modify this specification,  provided that if you redistribute a --
-- modified version,  any changes that you have made are clearly indicated. --
--                                                                          --

------------------------------------------------------------------------------
--  Note: although the values in System are target dependent, the source of
--  the package System itself is target independent in GNAT. This is achieved
--  by using attributes for all values, including the special additional GNAT

--  Standard attributes that are provided for exactly this purpose.
package System is
pragma Pure (System);
--  Note that we take advantage of the implementation permission to

--  make this unit Pure instead of Preelaborable, see RM 13.7(36)
   type Name is (SYSTEM_NAME_GNAT);

   System_Name : constant Name := SYSTEM_NAME_GNAT;

   --  System-Dependent Named Numbers
   Min_Int                : constant := Long_Long_Integer'First;

   Max_Int                : constant := Long_Long_Integer'Last;
   Max_Binary_Modulus     : constant := 2 ** Long_Long_Integer'Size;

   Max_Nonbinary_Modulus  : constant := Integer'Last;
   Max_Base_Digits        : constant := Long_Long_Float'Digits;

   Max_Digits             : constant := Long_Long_Float'Digits;
   Max_Mantissa           : constant := 63;

   Fine_Delta             : constant := 2.0 ** (-Max_Mantissa);

   Tick                   : constant := Standard'Tick;

   --  Storage-related Declarations
   type Address is private;

   Null_Address : constant Address;
   Storage_Unit           : constant := Standard'Storage_Unit;
   Word_Size              : constant := Standard'Word_Size;

   Memory_Size            : constant := 2 ** Standard'Address_Size;

   --  Address comparison
   function "<"  (Left, Right : Address) return Boolean;
   function "<=" (Left, Right : Address) return Boolean;
   function ">"  (Left, Right : Address) return Boolean;
   function ">=" (Left, Right : Address) return Boolean;

   function "="  (Left, Right : Address) return Boolean;
   pragma Import (Intrinsic, "<");
   pragma Import (Intrinsic, "<=");
   pragma Import (Intrinsic, ">");
   pragma Import (Intrinsic, ">=");

   pragma Import (Intrinsic, "=");

   --  Other System-Dependent Declarations
   type Bit_Order is (High_Order_First, Low_Order_First);

   Default_Bit_Order : constant Bit_Order;

   --  Priority-related Declarations (RM D.1)
   subtype Any_Priority is Integer

     range 0 .. Standard'Max_Interrupt_Priority;
   subtype Priority is Any_Priority

     range 0 .. Standard'Max_Priority;
   subtype Interrupt_Priority is Any_Priority

     range Standard'Max_Priority + 1 .. Standard'Max_Interrupt_Priority;
   Default_Priority : constant Priority :=

     (Priority'First + Priority'Last) / 2;

private
   type Address is mod Memory_Size;

   Null_Address : constant Address := 0;
   Default_Bit_Order : constant Bit_Order :=

                         Bit_Order'Val (Standard'Default_Bit_Order);
end System;