1------------------------------------------------------------------------------
2--                                                                          --
3--                        GNAT RUN-TIME COMPONENTS                          --
4--                                                                          --
5--                               S Y S T E M                                --
6--                                                                          --
7--                                 S p e c                                  --
8--                          (GNU-Linux/x86-64 Version)                      --
9--                                                                          --
10--          Copyright (C) 1992-2003 Free Software Foundation, Inc.          --
11--                                                                          --
12-- This specification is derived from the Ada Reference Manual for use with --
13-- GNAT. The copyright notice above, and the license provisions that follow --
14-- apply solely to the  contents of the part following the private keyword. --
15--                                                                          --
16-- GNAT is free software;  you can  redistribute it  and/or modify it under --
17-- terms of the  GNU General Public License as published  by the Free Soft- --
18-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
19-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
20-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
21-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
22-- for  more details.  You should have  received  a copy of the GNU General --
23-- Public License  distributed with GNAT;  see file COPYING.  If not, write --
24-- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
25-- MA 02111-1307, USA.                                                      --
26--                                                                          --
27-- As a special exception,  if other files  instantiate  generics from this --
28-- unit, or you link  this unit with other files  to produce an executable, --
29-- this  unit  does not  by itself cause  the resulting  executable  to  be --
30-- covered  by the  GNU  General  Public  License.  This exception does not --
31-- however invalidate  any other reasons why  the executable file  might be --
32-- covered by the  GNU Public License.                                      --
33--                                                                          --
34-- GNAT was originally developed  by the GNAT team at  New York University. --
35-- Extensive contributions were provided by Ada Core Technologies Inc.      --
36--                                                                          --
37------------------------------------------------------------------------------
38
39package System is
40pragma Pure (System);
41--  Note that we take advantage of the implementation permission to
42--  make this unit Pure instead of Preelaborable, see RM 13.7(36)
43
44   type Name is (SYSTEM_NAME_GNAT);
45   System_Name : constant Name := SYSTEM_NAME_GNAT;
46
47   --  System-Dependent Named Numbers
48
49   Min_Int               : constant := Long_Long_Integer'First;
50   Max_Int               : constant := Long_Long_Integer'Last;
51
52   Max_Binary_Modulus    : constant := 2 ** Long_Long_Integer'Size;
53   Max_Nonbinary_Modulus : constant := Integer'Last;
54
55   Max_Base_Digits       : constant := Long_Long_Float'Digits;
56   Max_Digits            : constant := Long_Long_Float'Digits;
57
58   Max_Mantissa          : constant := 63;
59   Fine_Delta            : constant := 2.0 ** (-Max_Mantissa);
60
61   Tick                  : constant := 0.000_001;
62
63   --  Storage-related Declarations
64
65   type Address is private;
66   Null_Address : constant Address;
67
68   Storage_Unit : constant := 8;
69   Word_Size    : constant := 64;
70   Memory_Size  : constant := 2 ** 64;
71
72   --  Address comparison
73
74   function "<"  (Left, Right : Address) return Boolean;
75   function "<=" (Left, Right : Address) return Boolean;
76   function ">"  (Left, Right : Address) return Boolean;
77   function ">=" (Left, Right : Address) return Boolean;
78   function "="  (Left, Right : Address) return Boolean;
79
80   pragma Import (Intrinsic, "<");
81   pragma Import (Intrinsic, "<=");
82   pragma Import (Intrinsic, ">");
83   pragma Import (Intrinsic, ">=");
84   pragma Import (Intrinsic, "=");
85
86   --  Other System-Dependent Declarations
87
88   type Bit_Order is (High_Order_First, Low_Order_First);
89   Default_Bit_Order : constant Bit_Order := Low_Order_First;
90
91   --  Priority-related Declarations (RM D.1)
92
93   Max_Priority           : constant Positive := 30;
94   Max_Interrupt_Priority : constant Positive := 31;
95
96   subtype Any_Priority       is Integer      range  0 .. 31;
97   subtype Priority           is Any_Priority range  0 .. 30;
98   subtype Interrupt_Priority is Any_Priority range 31 .. 31;
99
100   Default_Priority : constant Priority := 15;
101
102private
103
104   type Address is mod Memory_Size;
105   Null_Address : constant Address := 0;
106
107   --------------------------------------
108   -- System Implementation Parameters --
109   --------------------------------------
110
111   --  These parameters provide information about the target that is used
112   --  by the compiler. They are in the private part of System, where they
113   --  can be accessed using the special circuitry in the Targparm unit
114   --  whose source should be consulted for more detailed descriptions
115   --  of the individual switch values.
116
117   AAMP                      : constant Boolean := False;
118   Backend_Divide_Checks     : constant Boolean := False;
119   Backend_Overflow_Checks   : constant Boolean := False;
120   Command_Line_Args         : constant Boolean := True;
121   Configurable_Run_Time     : constant Boolean := False;
122   Denorm                    : constant Boolean := True;
123   Duration_32_Bits          : constant Boolean := False;
124   Exit_Status_Supported     : constant Boolean := True;
125   Fractional_Fixed_Ops      : constant Boolean := False;
126   Frontend_Layout           : constant Boolean := False;
127   Functions_Return_By_DSP   : constant Boolean := False;
128   Machine_Overflows         : constant Boolean := False;
129   Machine_Rounds            : constant Boolean := True;
130   OpenVMS                   : constant Boolean := False;
131   Signed_Zeros              : constant Boolean := True;
132   Stack_Check_Default       : constant Boolean := False;
133   Stack_Check_Probes        : constant Boolean := False;
134   Support_64_Bit_Divides    : constant Boolean := True;
135   Support_Aggregates        : constant Boolean := True;
136   Support_Composite_Assign  : constant Boolean := True;
137   Support_Composite_Compare : constant Boolean := True;
138   Support_Long_Shifts       : constant Boolean := True;
139   Suppress_Standard_Library : constant Boolean := False;
140   Use_Ada_Main_Program_Name : constant Boolean := False;
141   ZCX_By_Default            : constant Boolean := True;
142   GCC_ZCX_Support           : constant Boolean := True;
143   Front_End_ZCX_Support     : constant Boolean := False;
144
145   --  Obsolete entries, to be removed eventually (bootstrap issues!)
146
147   High_Integrity_Mode       : constant Boolean := False;
148   Long_Shifts_Inlined       : constant Boolean := True;
149
150end System;
151