1------------------------------------------------------------------------------
2--                                                                          --
3--                        GNAT RUN-TIME COMPONENTS                          --
4--                                                                          --
5--                               S Y S T E M                                --
6--                                                                          --
7--                                 S p e c                                  --
8--                            (Compiler Version)                            --
9--                                                                          --
10--          Copyright (C) 1992-2016 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 3,  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.                                     --
22--                                                                          --
23-- As a special exception under Section 7 of GPL version 3, you are granted --
24-- additional permissions described in the GCC Runtime Library Exception,   --
25-- version 3.1, as published by the Free Software Foundation.               --
26--                                                                          --
27-- You should have received a copy of the GNU General Public License and    --
28-- a copy of the GCC Runtime Library Exception along with this program;     --
29-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
30-- <http://www.gnu.org/licenses/>.                                          --
31--                                                                          --
32-- GNAT was originally developed  by the GNAT team at  New York University. --
33-- Extensive contributions were provided by Ada Core Technologies Inc.      --
34--                                                                          --
35------------------------------------------------------------------------------
36
37--  This version is for RTEMS.  It is based as closely as possible on the
38--  generic version with the following exceptions:
39--      + priority definitions
40
41package System is
42   pragma Pure;
43   --  Note that we take advantage of the implementation permission to make
44   --  this unit Pure instead of Preelaborable; see RM 13.7.1(15). In Ada
45   --  2005, this is Pure in any case (AI-362).
46
47   pragma No_Elaboration_Code_All;
48   --  Allow the use of that restriction in units that WITH this unit
49
50   type Name is (SYSTEM_NAME_GNAT);
51   System_Name : constant Name := SYSTEM_NAME_GNAT;
52
53   --  System-Dependent Named Numbers
54
55   Min_Int               : constant := Long_Long_Integer'First;
56   Max_Int               : constant := Long_Long_Integer'Last;
57
58   Max_Binary_Modulus    : constant := 2 ** Long_Long_Integer'Size;
59   Max_Nonbinary_Modulus : constant := Integer'Last;
60
61   Max_Base_Digits       : constant := Long_Long_Float'Digits;
62   Max_Digits            : constant := Long_Long_Float'Digits;
63
64   Max_Mantissa          : constant := 63;
65   Fine_Delta            : constant := 2.0 ** (-Max_Mantissa);
66
67   Tick                  : constant := 0.01;
68
69   --  Storage-related Declarations
70
71   type Address is private;
72   pragma Preelaborable_Initialization (Address);
73   Null_Address : constant Address;
74
75   Storage_Unit : constant := Standard'Storage_Unit;
76   Word_Size    : constant := Standard'Word_Size;
77   Memory_Size  : constant := 2 ** Standard'Address_Size;
78
79   --  Address comparison
80
81   function "<"  (Left, Right : Address) return Boolean;
82   function "<=" (Left, Right : Address) return Boolean;
83   function ">"  (Left, Right : Address) return Boolean;
84   function ">=" (Left, Right : Address) return Boolean;
85   function "="  (Left, Right : Address) return Boolean;
86
87   pragma Import (Intrinsic, "<");
88   pragma Import (Intrinsic, "<=");
89   pragma Import (Intrinsic, ">");
90   pragma Import (Intrinsic, ">=");
91   pragma Import (Intrinsic, "=");
92
93   --  Other System-Dependent Declarations
94
95   type Bit_Order is (High_Order_First, Low_Order_First);
96   Default_Bit_Order : constant Bit_Order :=
97                         Bit_Order'Val (Standard'Default_Bit_Order);
98   pragma Warnings (Off, Default_Bit_Order); -- kill constant condition warning
99
100   --  Priority-related Declarations (RM D.1)
101
102   --  RTEMS POSIX threads support 256 priority levels with 255 being
103   --  logically the most important. Levels 0 and 255 are reserved.
104   --
105   --  255        is reserved for RTEMS system tasks
106   --  247 - 254  correspond to hardware interrupt levels 0 .. 7
107   --  246        is a catchall default "interrupt" priority for signals,
108   --             allowing higher priority than normal tasks, but lower than
109   --             hardware priority levels.  Protected Object ceilings can
110   --             override these values.
111   --  245        is used by the Interrupt_Manager task
112   --  0          is reserved for the RTEMS IDLE task and really should not
113   --             be accessible from Ada but GNAT initializes
114   --             Current_Priority to 0 so it must be valid
115
116   Max_Priority           : constant Positive := 244;
117   Max_Interrupt_Priority : constant Positive := 254;
118
119   subtype Any_Priority       is Integer      range   0 .. 254;
120   subtype Priority           is Any_Priority range   0 .. 244;
121   subtype Interrupt_Priority is Any_Priority range 245 .. 254;
122
123   Default_Priority : constant Priority := 122;
124
125private
126
127   type Address is mod Memory_Size;
128   Null_Address : constant Address := 0;
129
130   --------------------------------------
131   -- System Implementation Parameters --
132   --------------------------------------
133
134   --  These parameters provide information about the target that is used
135   --  by the compiler. They are in the private part of System, where they
136   --  can be accessed using the special circuitry in the Targparm unit
137   --  whose source should be consulted for more detailed descriptions
138   --  of the individual switch values.
139
140   Backend_Divide_Checks     : constant Boolean := False;
141   Backend_Overflow_Checks   : constant Boolean := True;
142   Command_Line_Args         : constant Boolean := True;
143   Configurable_Run_Time     : constant Boolean := False;
144   Denorm                    : constant Boolean := True;
145   Duration_32_Bits          : constant Boolean := False;
146   Exit_Status_Supported     : constant Boolean := True;
147   Fractional_Fixed_Ops      : constant Boolean := False;
148   Frontend_Layout           : constant Boolean := False;
149   Machine_Overflows         : constant Boolean := False;
150   Machine_Rounds            : constant Boolean := True;
151   Preallocated_Stacks       : constant Boolean := False;
152   Signed_Zeros              : constant Boolean := True;
153   Stack_Check_Default       : constant Boolean := False;
154   Stack_Check_Probes        : constant Boolean := False;
155   Stack_Check_Limits        : constant Boolean := False;
156   Support_Aggregates        : constant Boolean := True;
157   Support_Composite_Assign  : constant Boolean := True;
158   Support_Composite_Compare : constant Boolean := True;
159   Support_Long_Shifts       : constant Boolean := True;
160   Always_Compatible_Rep     : constant Boolean := False;
161   Suppress_Standard_Library : constant Boolean := False;
162   Use_Ada_Main_Program_Name : constant Boolean := False;
163   Frontend_Exceptions       : constant Boolean := True;
164   ZCX_By_Default            : constant Boolean := False;
165
166end System;
167