File : system.ads
------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
5 -- S Y S T E M --
-- --
-- S p e c --
-- (NT Version) --
-- --
10 -- $Revision: 1.24 $
-- --
-- Copyright (C) 1992-2002 Free Software Foundation, Inc. --
-- --
-- This specification is derived from the Ada Reference Manual for use with --
15 -- GNAT. The copyright notice above, and the license provisions that follow --
-- apply solely to the contents of the part following the private keyword. --
-- --
-- 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- --
20 -- ware Foundation; either version 2, 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 --
25 -- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
30 -- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
35 -- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
40
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)
45
type Name is (SYSTEM_NAME_GNAT);
System_Name : constant Name := SYSTEM_NAME_GNAT;
-- System-Dependent Named Numbers
50
Min_Int : constant := Long_Long_Integer'First;
Max_Int : constant := Long_Long_Integer'Last;
Max_Binary_Modulus : constant := 2 ** Long_Long_Integer'Size;
55 Max_Nonbinary_Modulus : constant := Integer'Last;
Max_Base_Digits : constant := Long_Long_Float'Digits;
Max_Digits : constant := Long_Long_Float'Digits;
60 Max_Mantissa : constant := 63;
Fine_Delta : constant := 2.0 ** (-Max_Mantissa);
Tick : constant := 1.0;
65 -- Storage-related Declarations
type Address is private;
Null_Address : constant Address;
70 Storage_Unit : constant := 8;
Word_Size : constant := 32;
Memory_Size : constant := 2 ** 32;
-- Address comparison
75
function "<" (Left, Right : Address) return Boolean;
function "<=" (Left, Right : Address) return Boolean;
function ">" (Left, Right : Address) return Boolean;
function ">=" (Left, Right : Address) return Boolean;
80 function "=" (Left, Right : Address) return Boolean;
pragma Import (Intrinsic, "<");
pragma Import (Intrinsic, "<=");
pragma Import (Intrinsic, ">");
85 pragma Import (Intrinsic, ">=");
pragma Import (Intrinsic, "=");
-- Other System-Dependent Declarations
90 type Bit_Order is (High_Order_First, Low_Order_First);
Default_Bit_Order : constant Bit_Order := Low_Order_First;
-- Priority-related Declarations (RM D.1)
95 Max_Priority : constant Positive := 30;
Max_Interrupt_Priority : constant Positive := 31;
subtype Any_Priority is Integer range 0 .. 31;
subtype Priority is Any_Priority range 0 .. 30;
100 subtype Interrupt_Priority is Any_Priority range 31 .. 31;
Default_Priority : constant Priority := 15;
private
105
type Address is mod Memory_Size;
Null_Address : constant Address := 0;
--------------------------------------
110 -- System Implementation Parameters --
--------------------------------------
-- These parameters provide information about the target that is used
-- by the compiler. They are in the private part of System, where they
115 -- can be accessed using the special circuitry in the Targparm unit
-- whose source should be consulted for more detailed descriptions
-- of the individual switch values.
AAMP : constant Boolean := False;
120 Backend_Divide_Checks : constant Boolean := False;
Backend_Overflow_Checks : constant Boolean := False;
Command_Line_Args : constant Boolean := True;
Denorm : constant Boolean := True;
Fractional_Fixed_Ops : constant Boolean := False;
125 Frontend_Layout : constant Boolean := False;
Functions_Return_By_DSP : constant Boolean := False;
Long_Shifts_Inlined : constant Boolean := True;
High_Integrity_Mode : constant Boolean := False;
Machine_Overflows : constant Boolean := False;
130 Machine_Rounds : constant Boolean := True;
OpenVMS : constant Boolean := False;
Signed_Zeros : constant Boolean := True;
Stack_Check_Default : constant Boolean := False;
Stack_Check_Probes : constant Boolean := False;
135 Use_Ada_Main_Program_Name : constant Boolean := False;
ZCX_By_Default : constant Boolean := False;
GCC_ZCX_Support : constant Boolean := False;
Front_End_ZCX_Support : constant Boolean := True;
140 ---------------------------
-- Underlying Priorities --
---------------------------
-- Important note: this section of the file must come AFTER the
145 -- definition of the system implementation parameters to ensure
-- that the value of these parameters is available for analysis
-- of the declarations here (using Rtsfind at compile time).
-- The underlying priorities table provides a generalized mechanism
150 -- for mapping from Ada priorities to system priorities. In some
-- cases a 1-1 mapping is not the convenient or optimal choice.
type Priorities_Mapping is array (Any_Priority) of Integer;
pragma Suppress_Initialization (Priorities_Mapping);
155 -- Suppress initialization in case gnat.adc specifies Normalize_Scalars
-- On NT, the default mapping preserves the standard 31 priorities
-- of the Ada model, but maps them using compression onto the 7
-- priority levels available in NT.
160
-- To replace the default values of the Underlying_Priorities mapping,
-- copy this source file into your build directory, edit the file to
-- reflect your desired behavior, and recompile with the command:
165 -- $ gcc -c -O3 -gnatpgn system.ads
-- then recompile the run-time parts that depend on this package:
-- $ gnatmake -a -gnatn -O3 <your application>
170
-- then force rebuilding your application if you need different options:
-- $ gnatmake -f <your options> <your application>
175 Underlying_Priorities : constant Priorities_Mapping :=
(Priority'First .. 1 => -15,
2 .. Default_Priority - 2 => -2,
180
Default_Priority - 1 => -1,
Default_Priority => 0,
185 Default_Priority + 1 .. 19 => 1,
20 .. Priority'Last => 2,
Interrupt_Priority => 15);
190
pragma Linker_Options ("-Wl,--stack=0x2000000");
-- This is used to change the default stack (32 MB) size for non tasking
-- programs. We change this value for GNAT on Windows here because the
-- binutils on this platform have switched to a too low value for Ada
195 -- programs. Note that we also set the stack size for tasking programs in
-- System.Task_Primitives.Operations.
end System;