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1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME COMPONENTS --
4 -- --
5 -- S Y S T E M --
6 -- --
7 -- S p e c --
8 -- (Windows Version) --
9 -- --
10 -- Copyright (C) 1992-2014, 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 ------------------------------------------------------------------------------
37 package System is
38 pragma Pure;
39 -- Note that we take advantage of the implementation permission to make
40 -- this unit Pure instead of Preelaborable; see RM 13.7.1(15). In Ada
41 -- 2005, this is Pure in any case (AI-362).
43 pragma No_Elaboration_Code_All;
44 -- Allow the use of that restriction in units that WITH this unit
46 type Name is (SYSTEM_NAME_GNAT);
47 System_Name : constant Name := SYSTEM_NAME_GNAT;
49 -- System-Dependent Named Numbers
51 Min_Int : constant := Long_Long_Integer'First;
52 Max_Int : constant := Long_Long_Integer'Last;
54 Max_Binary_Modulus : constant := 2 ** Long_Long_Integer'Size;
55 Max_Nonbinary_Modulus : constant := 2 ** Integer'Size - 1;
57 Max_Base_Digits : constant := Long_Long_Float'Digits;
58 Max_Digits : constant := Long_Long_Float'Digits;
60 Max_Mantissa : constant := 63;
61 Fine_Delta : constant := 2.0 ** (-Max_Mantissa);
63 Tick : constant := 0.01;
65 -- Storage-related Declarations
67 type Address is private;
68 pragma Preelaborable_Initialization (Address);
69 Null_Address : constant Address;
71 Storage_Unit : constant := 8;
72 Word_Size : constant := 32;
73 Memory_Size : constant := 2 ** 32;
75 -- Address comparison
77 function "<" (Left, Right : Address) return Boolean;
78 function "<=" (Left, Right : Address) return Boolean;
79 function ">" (Left, Right : Address) return Boolean;
80 function ">=" (Left, Right : Address) return Boolean;
81 function "=" (Left, Right : Address) return Boolean;
83 pragma Import (Intrinsic, "<");
84 pragma Import (Intrinsic, "<=");
85 pragma Import (Intrinsic, ">");
86 pragma Import (Intrinsic, ">=");
87 pragma Import (Intrinsic, "=");
89 -- Other System-Dependent Declarations
91 type Bit_Order is (High_Order_First, Low_Order_First);
92 Default_Bit_Order : constant Bit_Order := Low_Order_First;
93 pragma Warnings (Off, Default_Bit_Order); -- kill constant condition warning
95 -- Priority-related Declarations (RM D.1)
97 Max_Priority : constant Positive := 30;
98 Max_Interrupt_Priority : constant Positive := 31;
100 subtype Any_Priority is Integer range 0 .. 31;
101 subtype Priority is Any_Priority range 0 .. 30;
102 subtype Interrupt_Priority is Any_Priority range 31 .. 31;
104 Default_Priority : constant Priority := 15;
106 private
108 type Address is mod Memory_Size;
109 Null_Address : constant Address := 0;
111 --------------------------------------
112 -- System Implementation Parameters --
113 --------------------------------------
115 -- These parameters provide information about the target that is used
116 -- by the compiler. They are in the private part of System, where they
117 -- can be accessed using the special circuitry in the Targparm unit
118 -- whose source should be consulted for more detailed descriptions
119 -- of the individual switch values.
121 Backend_Divide_Checks : constant Boolean := False;
122 Backend_Overflow_Checks : constant Boolean := True;
123 Command_Line_Args : constant Boolean := True;
124 Configurable_Run_Time : constant Boolean := False;
125 Denorm : constant Boolean := True;
126 Duration_32_Bits : constant Boolean := False;
127 Exit_Status_Supported : constant Boolean := True;
128 Fractional_Fixed_Ops : constant Boolean := False;
129 Frontend_Layout : constant Boolean := False;
130 Machine_Overflows : constant Boolean := False;
131 Machine_Rounds : constant Boolean := True;
132 Preallocated_Stacks : constant Boolean := False;
133 Signed_Zeros : constant Boolean := True;
134 Stack_Check_Default : constant Boolean := False;
135 Stack_Check_Probes : constant Boolean := True;
136 Stack_Check_Limits : constant Boolean := False;
137 Support_Aggregates : constant Boolean := True;
138 Support_Atomic_Primitives : constant Boolean := True;
139 Support_Composite_Assign : constant Boolean := True;
140 Support_Composite_Compare : constant Boolean := True;
141 Support_Long_Shifts : constant Boolean := True;
142 Always_Compatible_Rep : constant Boolean := False;
143 Suppress_Standard_Library : constant Boolean := False;
144 Use_Ada_Main_Program_Name : constant Boolean := False;
145 ZCX_By_Default : constant Boolean := True;
147 ---------------------------
148 -- Underlying Priorities --
149 ---------------------------
151 -- Important note: this section of the file must come AFTER the
152 -- definition of the system implementation parameters to ensure
153 -- that the value of these parameters is available for analysis
154 -- of the declarations here (using Rtsfind at compile time).
156 -- The underlying priorities table provides a generalized mechanism
157 -- for mapping from Ada priorities to system priorities. In some
158 -- cases a 1-1 mapping is not the convenient or optimal choice.
160 type Priorities_Mapping is array (Any_Priority) of Integer;
161 pragma Suppress_Initialization (Priorities_Mapping);
162 -- Suppress initialization in case gnat.adc specifies Normalize_Scalars
164 Underlying_Priorities : constant Priorities_Mapping :=
165 (Priority'First ..
166 Default_Priority - 8 => -15,
167 Default_Priority - 7 => -7,
168 Default_Priority - 6 => -6,
169 Default_Priority - 5 => -5,
170 Default_Priority - 4 => -4,
171 Default_Priority - 3 => -3,
172 Default_Priority - 2 => -2,
173 Default_Priority - 1 => -1,
174 Default_Priority => 0,
175 Default_Priority + 1 => 1,
176 Default_Priority + 2 => 2,
177 Default_Priority + 3 => 3,
178 Default_Priority + 4 => 4,
179 Default_Priority + 5 => 5,
180 Default_Priority + 6 ..
181 Priority'Last => 6,
182 Interrupt_Priority => 15);
183 -- The default mapping preserves the standard 31 priorities of the Ada
184 -- model, but maps them using compression onto the 7 priority levels
185 -- available in NT and on the 16 priority levels available in 2000/XP.
187 -- To replace the default values of the Underlying_Priorities mapping,
188 -- copy this source file into your build directory, edit the file to
189 -- reflect your desired behavior, and recompile using Makefile.adalib
190 -- which can be found under the adalib directory of your gnat installation
192 pragma Linker_Options ("-Wl,--stack=0x2000000");
193 -- This is used to change the default stack (32 MB) size for non tasking
194 -- programs. We change this value for GNAT on Windows here because the
195 -- binutils on this platform have switched to a too low value for Ada
196 -- programs. Note that we also set the stack size for tasking programs in
197 -- System.Task_Primitives.Operations.
199 end System;