1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
10 -- Copyright (C) 1992-2023, Free Software Foundation, Inc. --
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. --
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. --
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. --
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/>. --
32 -- GNAT was originally developed by the GNAT team at New York University. --
33 -- Extensive contributions were provided by Ada Core Technologies Inc. --
35 ------------------------------------------------------------------------------
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 := -2 ** (Standard
'Max_Integer_Size - 1);
52 Max_Int
: constant := 2 ** (Standard
'Max_Integer_Size - 1) - 1;
54 Max_Binary_Modulus
: constant := 2 ** Standard
'Max_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 := Standard
'Max_Integer_Size - 1;
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;
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
:= High_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;
108 type Address
is mod Memory_Size
;
109 for Address
'Size use Standard
'Address_Size;
111 Null_Address
: constant Address
:= 0;
113 --------------------------------------
114 -- System Implementation Parameters --
115 --------------------------------------
117 -- These parameters provide information about the target that is used
118 -- by the compiler. They are in the private part of System, where they
119 -- can be accessed using the special circuitry in the Targparm unit
120 -- whose source should be consulted for more detailed descriptions
121 -- of the individual switch values.
123 Backend_Divide_Checks
: constant Boolean := False;
124 Backend_Overflow_Checks
: constant Boolean := True;
125 Command_Line_Args
: constant Boolean := True;
126 Configurable_Run_Time
: constant Boolean := False;
127 Denorm
: constant Boolean := True;
128 Duration_32_Bits
: constant Boolean := False;
129 Exit_Status_Supported
: constant Boolean := True;
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_Composite_Assign
: constant Boolean := True;
139 Support_Composite_Compare
: constant Boolean := True;
140 Support_Long_Shifts
: constant Boolean := True;
141 Always_Compatible_Rep
: constant Boolean := False;
142 Suppress_Standard_Library
: constant Boolean := False;
143 Use_Ada_Main_Program_Name
: constant Boolean := False;
144 ZCX_By_Default
: constant Boolean := True;
146 --------------------------
147 -- Underlying Priorities --
148 ---------------------------
150 -- Important note: this section of the file must come AFTER the
151 -- definition of the system implementation parameters to ensure
152 -- that the value of these parameters is available for analysis
153 -- of the declarations here (using Rtsfind at compile time).
155 -- The underlying priorities table provides a generalized mechanism
156 -- for mapping from Ada priorities to system priorities. In some
157 -- cases a 1-1 mapping is not the convenient or optimal choice.
159 -- For HP/UX DCE Threads, we use the full range of 31 priorities
160 -- in the Ada model, but map them by compression onto the more limited
161 -- range of priorities available in HP/UX.
162 -- For POSIX Threads, this table is ignored.
164 -- To replace the default values of the Underlying_Priorities mapping,
165 -- copy this source file into your build directory, edit the file to
166 -- reflect your desired behavior, and recompile with the command:
168 -- $ gcc -c -O2 -gnatpgn system.ads
170 -- then recompile the run-time parts that depend on this package:
172 -- $ gnatmake -a -gnatn -O2 <your application>
174 -- then force rebuilding your application if you need different options:
176 -- $ gnatmake -f <your options> <your application>
178 type Priorities_Mapping
is array (Any_Priority
) of Integer;
179 pragma Suppress_Initialization
(Priorities_Mapping
);
180 -- Suppress initialization in case gnat.adc specifies Normalize_Scalars
182 Underlying_Priorities
: constant Priorities_Mapping
:=
184 (Priority
'First => 16,
201 Default_Priority
=> 24,
220 Interrupt_Priority
=> 31);