1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME COMPONENTS -- 4-- -- 5-- S Y S T E M -- 6-- -- 7-- S p e c -- 8-- (OpenVMS 64bit GCC_ZCX DEC Threads Version) -- 9-- -- 10-- Copyright (C) 1992-2012, 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 37package 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). 42 43 type Name is (SYSTEM_NAME_GNAT); 44 System_Name : constant Name := SYSTEM_NAME_GNAT; 45 46 -- System-Dependent Named Numbers 47 48 Min_Int : constant := Long_Long_Integer'First; 49 Max_Int : constant := Long_Long_Integer'Last; 50 51 Max_Binary_Modulus : constant := 2 ** Long_Long_Integer'Size; 52 Max_Nonbinary_Modulus : constant := 2 ** Integer'Size - 1; 53 54 Max_Base_Digits : constant := Long_Long_Float'Digits; 55 Max_Digits : constant := Long_Long_Float'Digits; 56 57 Max_Mantissa : constant := 63; 58 Fine_Delta : constant := 2.0 ** (-Max_Mantissa); 59 60 Tick : constant := 0.01; 61 62 -- Storage-related Declarations 63 64 type Address is new Long_Integer; 65 Null_Address : constant Address; 66 -- Although this is declared as an integer type, no arithmetic operations 67 -- are available (see abstract declarations below), and furthermore there 68 -- is special processing in the compiler that prevents the use of integer 69 -- literals with this type (use To_Address to convert integer literals). 70 -- 71 -- Conversion to and from Short_Address is however freely permitted, and 72 -- is indeed the reason that Address is declared as an integer type. 73 74 Storage_Unit : constant := 8; 75 Word_Size : constant := 64; 76 Memory_Size : constant := 2 ** 64; 77 78 -- Address comparison 79 80 function "<" (Left, Right : Address) return Boolean; 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 86 pragma Import (Intrinsic, "<"); 87 pragma Import (Intrinsic, "<="); 88 pragma Import (Intrinsic, ">"); 89 pragma Import (Intrinsic, ">="); 90 pragma Import (Intrinsic, "="); 91 92 -- Abstract declarations for arithmetic operations on type address. 93 -- These declarations are needed when Address is non-private. They 94 -- avoid excessive visibility of arithmetic operations on address 95 -- which are typically available elsewhere (e.g. Storage_Elements) 96 -- and which would cause excessive ambiguities in application code. 97 98 function "+" (Left, Right : Address) return Address is abstract; 99 function "-" (Left, Right : Address) return Address is abstract; 100 function "/" (Left, Right : Address) return Address is abstract; 101 function "*" (Left, Right : Address) return Address is abstract; 102 function "mod" (Left, Right : Address) return Address is abstract; 103 104 -- Other System-Dependent Declarations 105 106 type Bit_Order is (High_Order_First, Low_Order_First); 107 Default_Bit_Order : constant Bit_Order := Low_Order_First; 108 pragma Warnings (Off, Default_Bit_Order); -- kill constant condition warning 109 110 -- Priority-related Declarations (RM D.1) 111 112 Max_Priority : constant Positive := 30; 113 Max_Interrupt_Priority : constant Positive := 31; 114 115 subtype Any_Priority is Integer range 0 .. 31; 116 subtype Priority is Any_Priority range 0 .. 30; 117 subtype Interrupt_Priority is Any_Priority range 31 .. 31; 118 119 Default_Priority : constant Priority := 15; 120 121private 122 123 Null_Address : constant Address := 0; 124 125 -------------------------------------- 126 -- System Implementation Parameters -- 127 -------------------------------------- 128 129 -- These parameters provide information about the target that is used 130 -- by the compiler. They are in the private part of System, where they 131 -- can be accessed using the special circuitry in the Targparm unit 132 -- whose source should be consulted for more detailed descriptions 133 -- of the individual switch values. 134 135 Backend_Divide_Checks : constant Boolean := False; 136 Backend_Overflow_Checks : constant Boolean := True; 137 Command_Line_Args : constant Boolean := True; 138 Configurable_Run_Time : constant Boolean := False; 139 Denorm : constant Boolean := False; 140 Duration_32_Bits : constant Boolean := False; 141 Exit_Status_Supported : constant Boolean := True; 142 Fractional_Fixed_Ops : constant Boolean := False; 143 Frontend_Layout : constant Boolean := False; 144 Machine_Overflows : constant Boolean := False; 145 Machine_Rounds : constant Boolean := True; 146 OpenVMS : constant Boolean := True; 147 Preallocated_Stacks : constant Boolean := False; 148 Signed_Zeros : constant Boolean := True; 149 Stack_Check_Default : constant Boolean := True; 150 Stack_Check_Probes : constant Boolean := True; 151 Stack_Check_Limits : constant Boolean := False; 152 Support_Aggregates : constant Boolean := True; 153 Support_Atomic_Primitives : constant Boolean := True; 154 Support_Composite_Assign : constant Boolean := True; 155 Support_Composite_Compare : constant Boolean := True; 156 Support_Long_Shifts : constant Boolean := True; 157 Always_Compatible_Rep : constant Boolean := True; 158 Suppress_Standard_Library : constant Boolean := False; 159 Use_Ada_Main_Program_Name : constant Boolean := False; 160 ZCX_By_Default : constant Boolean := True; 161 162 -------------------------- 163 -- Underlying Priorities -- 164 --------------------------- 165 166 -- Important note: this section of the file must come AFTER the 167 -- definition of the system implementation parameters to ensure 168 -- that the value of these parameters is available for analysis 169 -- of the declarations here (using Rtsfind at compile time). 170 171 -- The underlying priorities table provides a generalized mechanism 172 -- for mapping from Ada priorities to system priorities. In some 173 -- cases a 1-1 mapping is not the convenient or optimal choice. 174 175 -- For DEC Threads OpenVMS, we use the full range of 31 priorities 176 -- in the Ada model, but map them by compression onto the more limited 177 -- range of priorities available in OpenVMS. 178 179 -- To replace the default values of the Underlying_Priorities mapping, 180 -- copy this source file into your build directory, edit the file to 181 -- reflect your desired behavior, and recompile with the command: 182 183 -- $ gcc -c -O3 -gnatpgn system.ads 184 185 -- then recompile the run-time parts that depend on this package: 186 187 -- $ gnatmake -a -gnatn -O3 <your application> 188 189 -- then force rebuilding your application if you need different options: 190 191 -- $ gnatmake -f <your options> <your application> 192 193 type Priorities_Mapping is array (Any_Priority) of Integer; 194 pragma Suppress_Initialization (Priorities_Mapping); 195 -- Suppress initialization in case gnat.adc specifies Normalize_Scalars 196 197 Underlying_Priorities : constant Priorities_Mapping := 198 199 (Priority'First => 16, 200 201 1 => 17, 202 2 => 18, 203 3 => 18, 204 4 => 18, 205 5 => 18, 206 6 => 19, 207 7 => 19, 208 8 => 19, 209 9 => 20, 210 10 => 20, 211 11 => 21, 212 12 => 21, 213 13 => 22, 214 14 => 23, 215 216 Default_Priority => 24, 217 218 16 => 25, 219 17 => 25, 220 18 => 25, 221 19 => 26, 222 20 => 26, 223 21 => 26, 224 22 => 27, 225 23 => 27, 226 24 => 27, 227 25 => 28, 228 26 => 28, 229 27 => 29, 230 28 => 29, 231 29 => 30, 232 233 Priority'Last => 30, 234 235 Interrupt_Priority => 31); 236 237 ---------------------------- 238 -- Special VMS Interfaces -- 239 ---------------------------- 240 241 procedure Lib_Stop (Cond_Value : Integer); 242 pragma Import (C, Lib_Stop); 243 pragma Import_Procedure (Lib_Stop, "LIB$STOP", Mechanism => (Value)); 244 -- Interface to VMS condition handling. Used by RTSfind and pragma 245 -- {Import,Export}_Exception. Put here because this is the only 246 -- VMS specific package that doesn't drag in tasking. 247 248 ADA_GNAT : constant Boolean := True; 249 pragma Export_Object (ADA_GNAT, "ADA$GNAT"); 250 -- Ubiquitous global symbol identifying a GNAT compiled image to VMS Debug. 251 -- Do not remove! 252 253 pragma Ident ("GNAT"); -- Gnat_Static_Version_String 254 -- Default ident for all VMS images. 255 256end System; 257