gcc/ada/system-vms.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                        GNAT RUN-TIME COMPONENTS                          --
   4 --                                                                          --
   5 --                               S Y S T E M                                --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                       (OpenVMS DEC Threads Version)                      --
   9 --                                                                          --
  10 --          Copyright (C) 1992-2009, 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 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).
  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 private;
  65    pragma Preelaborable_Initialization (Address);
  66    Null_Address : constant Address;
  67
  68    Storage_Unit : constant := 8;
  69    Word_Size    : constant := 32;
  70    Memory_Size  : constant := 2 ** 32;
  71
  72    --  Address comparison
  73
  74    function "<"  (Left, Right : Address) return Boolean;
  75    function "<=" (Left, Right : Address) return Boolean;
  76    function ">"  (Left, Right : Address) return Boolean;
  77    function ">=" (Left, Right : Address) return Boolean;
  78    function "="  (Left, Right : Address) return Boolean;
  79
  80    pragma Import (Intrinsic, "<");
  81    pragma Import (Intrinsic, "<=");
  82    pragma Import (Intrinsic, ">");
  83    pragma Import (Intrinsic, ">=");
  84    pragma Import (Intrinsic, "=");
  85
  86    --  Other System-Dependent Declarations
  87
  88    type Bit_Order is (High_Order_First, Low_Order_First);
  89    Default_Bit_Order : constant Bit_Order := Low_Order_First;
  90    pragma Warnings (Off, Default_Bit_Order); -- kill constant condition warning
  91
  92    --  Priority-related Declarations (RM D.1)
  93
  94    Max_Priority           : constant Positive := 30;
  95    Max_Interrupt_Priority : constant Positive := 31;
  96
  97    subtype Any_Priority       is Integer      range  0 .. 31;
  98    subtype Priority           is Any_Priority range  0 .. 30;
  99    subtype Interrupt_Priority is Any_Priority range 31 .. 31;
 100
 101    Default_Priority : constant Priority := 15;
 102
 103 private
 104
 105    type Address is mod Memory_Size;
 106    Null_Address : constant Address := 0;
 107
 108    --------------------------------------
 109    -- System Implementation Parameters --
 110    --------------------------------------
 111
 112    --  These parameters provide information about the target that is used
 113    --  by the compiler. They are in the private part of System, where they
 114    --  can be accessed using the special circuitry in the Targparm unit
 115    --  whose source should be consulted for more detailed descriptions
 116    --  of the individual switch values.
 117
 118    Backend_Divide_Checks     : constant Boolean := False;
 119    Backend_Overflow_Checks   : constant Boolean := True;
 120    Command_Line_Args         : constant Boolean := True;
 121    Configurable_Run_Time     : constant Boolean := False;
 122    Denorm                    : constant Boolean := False;
 123    Duration_32_Bits          : constant Boolean := False;
 124    Exit_Status_Supported     : constant Boolean := True;
 125    Fractional_Fixed_Ops      : constant Boolean := False;
 126    Frontend_Layout           : constant Boolean := False;
 127    Machine_Overflows         : constant Boolean := False;
 128    Machine_Rounds            : constant Boolean := True;
 129    OpenVMS                   : constant Boolean := True;
 130    Preallocated_Stacks       : constant Boolean := False;
 131    Signed_Zeros              : constant Boolean := True;
 132    Stack_Check_Default       : constant Boolean := True;
 133    Stack_Check_Probes        : constant Boolean := True;
 134    Stack_Check_Limits        : constant Boolean := False;
 135    Support_64_Bit_Divides    : constant Boolean := True;
 136    Support_Aggregates        : constant Boolean := True;
 137    Support_Composite_Assign  : constant Boolean := True;
 138    Support_Composite_Compare : constant Boolean := True;
 139    Support_Long_Shifts       : constant Boolean := True;
 140    Always_Compatible_Rep     : constant Boolean := True;
 141    Suppress_Standard_Library : constant Boolean := False;
 142    Use_Ada_Main_Program_Name : constant Boolean := False;
 143    ZCX_By_Default            : constant Boolean := True;
 144    GCC_ZCX_Support           : constant Boolean := False;
 145
 146    --------------------------
 147    -- Underlying Priorities --
 148    ---------------------------
 149
 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).
 154
 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.
 158
 159    --  For DEC Threads OpenVMS, 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 OpenVMS.
 162
 163    --  To replace the default values of the Underlying_Priorities mapping,
 164    --  copy this source file into your build directory, edit the file to
 165    --  reflect your desired behavior, and recompile with the command:
 166
 167    --     $ gcc -c -O3 -gnatpgn system.ads
 168
 169    --  then recompile the run-time parts that depend on this package:
 170
 171    --     $ gnatmake -a -gnatn -O3 <your application>
 172
 173    --  then force rebuilding your application if you need different options:
 174
 175    --     $ gnatmake -f <your options> <your application>
 176
 177    type Priorities_Mapping is array (Any_Priority) of Integer;
 178    pragma Suppress_Initialization (Priorities_Mapping);
 179    --  Suppress initialization in case gnat.adc specifies Normalize_Scalars
 180
 181    Underlying_Priorities : constant Priorities_Mapping :=
 182
 183      (Priority'First => 16,
 184
 185       1  => 17,
 186       2  => 18,
 187       3  => 18,
 188       4  => 18,
 189       5  => 18,
 190       6  => 19,
 191       7  => 19,
 192       8  => 19,
 193       9  => 20,
 194       10 => 20,
 195       11 => 21,
 196       12 => 21,
 197       13 => 22,
 198       14 => 23,
 199
 200       Default_Priority   => 24,
 201
 202       16 => 25,
 203       17 => 25,
 204       18 => 25,
 205       19 => 26,
 206       20 => 26,
 207       21 => 26,
 208       22 => 27,
 209       23 => 27,
 210       24 => 27,
 211       25 => 28,
 212       26 => 28,
 213       27 => 29,
 214       28 => 29,
 215       29 => 30,
 216
 217       Priority'Last      => 30,
 218
 219       Interrupt_Priority => 31);
 220
 221    ----------------------------
 222    -- Special VMS Interfaces --
 223    ----------------------------
 224
 225    procedure Lib_Stop (I : Integer);
 226    pragma Interface (C, Lib_Stop);
 227    pragma Import_Procedure (Lib_Stop, "LIB$STOP", Mechanism => (Value));
 228    --  Interface to VMS condition handling. Used by RTSfind and pragma
 229    --  {Import,Export}_Exception. Put here because this is the only
 230    --  VMS specific package that doesn't drag in tasking.
 231
 232    ADA_GNAT : constant Boolean := True;
 233    pragma Export_Object (ADA_GNAT, "ADA$GNAT");
 234    --  Ubiquitous global symbol identifying a GNAT compiled image to VMS Debug.
 235    --  Do not remove!
 236
 237 end System;