gcc/ada/system-vms_64.ads

   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) 2004 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 2,  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.  See the GNU General Public License --
  22 -- for  more details.  You should have  received  a copy of the GNU General --
  23 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  24 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  25 -- MA 02111-1307, USA.                                                      --
  26 --                                                                          --
  27 -- As a special exception,  if other files  instantiate  generics from this --
  28 -- unit, or you link  this unit with other files  to produce an executable, --
  29 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  30 -- covered  by the  GNU  General  Public  License.  This exception does not --
  31 -- however invalidate  any other reasons why  the executable file  might be --
  32 -- covered by the  GNU Public License.                                      --
  33 --                                                                          --
  34 -- GNAT was originally developed  by the GNAT team at  New York University. --
  35 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  36 --                                                                          --
  37 ------------------------------------------------------------------------------
  38
  39 package System is
  40 pragma Pure (System);
  41 --  Note that we take advantage of the implementation permission to
  42 --  make this unit Pure instead of Preelaborable, see RM 13.7(36)
  43
  44    type Name is (SYSTEM_NAME_GNAT);
  45    System_Name : constant Name := SYSTEM_NAME_GNAT;
  46
  47    --  System-Dependent Named Numbers
  48
  49    Min_Int               : constant := Long_Long_Integer'First;
  50    Max_Int               : constant := Long_Long_Integer'Last;
  51
  52    Max_Binary_Modulus    : constant := 2 ** Long_Long_Integer'Size;
  53    Max_Nonbinary_Modulus : constant := Integer'Last;
  54
  55    Max_Base_Digits       : constant := Long_Long_Float'Digits;
  56    Max_Digits            : constant := Long_Long_Float'Digits;
  57
  58    Max_Mantissa          : constant := 63;
  59    Fine_Delta            : constant := 2.0 ** (-Max_Mantissa);
  60
  61    Tick                  : constant := 0.01;
  62
  63    --  Storage-related Declarations
  64
  65    type Address is new Long_Integer;
  66    Null_Address : constant Address;
  67    --  Although this is declared as an integer type, no arithmetic operations
  68    --  are available (see abstract declarations below), and furthermore there
  69    --  is special processing in the compiler that prevents the use of integer
  70    --  literals with this type (use To_Address to convert integer literals).
  71    --
  72    --  Conversion to and from Short_Address is however freely permitted, and
  73    --  is indeed the reason that Address is declared as an integer type. See
  74    --
  75
  76    Storage_Unit : constant := 8;
  77    Word_Size    : constant := 64;
  78    Memory_Size  : constant := 2 ** 64;
  79
  80    --  Address comparison
  81
  82    function "<"  (Left, Right : Address) return Boolean;
  83    function "<=" (Left, Right : Address) return Boolean;
  84    function ">"  (Left, Right : Address) return Boolean;
  85    function ">=" (Left, Right : Address) return Boolean;
  86    function "="  (Left, Right : Address) return Boolean;
  87
  88    pragma Import (Intrinsic, "<");
  89    pragma Import (Intrinsic, "<=");
  90    pragma Import (Intrinsic, ">");
  91    pragma Import (Intrinsic, ">=");
  92    pragma Import (Intrinsic, "=");
  93
  94    --  Abstract declarations for arithmetic operations on type address.
  95    --  These declarations are needed when Address is non-private. They
  96    --  avoid excessive visibility of arithmetic operations on address
  97    --  which are typically available elsewhere (e.g. Storage_Elements)
  98    --  and which would cause excessive ambiguities in application code.
  99
 100    function "+"   (Left, Right : Address) return Address is abstract;
 101    function "-"   (Left, Right : Address) return Address is abstract;
 102    function "/"   (Left, Right : Address) return Address is abstract;
 103    function "*"   (Left, Right : Address) return Address is abstract;
 104    function "mod" (Left, Right : Address) return Address is abstract;
 105
 106    --  Other System-Dependent Declarations
 107
 108    type Bit_Order is (High_Order_First, Low_Order_First);
 109    Default_Bit_Order : constant Bit_Order := Low_Order_First;
 110
 111    --  Priority-related Declarations (RM D.1)
 112
 113    Max_Priority           : constant Positive := 30;
 114    Max_Interrupt_Priority : constant Positive := 31;
 115
 116    subtype Any_Priority       is Integer      range  0 .. 31;
 117    subtype Priority           is Any_Priority range  0 .. 30;
 118    subtype Interrupt_Priority is Any_Priority range 31 .. 31;
 119
 120    Default_Priority : constant Priority := 15;
 121
 122 private
 123
 124    Null_Address : constant Address := 0;
 125
 126    --------------------------------------
 127    -- System Implementation Parameters --
 128    --------------------------------------
 129
 130    --  These parameters provide information about the target that is used
 131    --  by the compiler. They are in the private part of System, where they
 132    --  can be accessed using the special circuitry in the Targparm unit
 133    --  whose source should be consulted for more detailed descriptions
 134    --  of the individual switch values.
 135
 136    AAMP                      : constant Boolean := False;
 137    Backend_Divide_Checks     : constant Boolean := False;
 138    Backend_Overflow_Checks   : constant Boolean := False;
 139    Command_Line_Args         : constant Boolean := True;
 140    Configurable_Run_Time     : constant Boolean := False;
 141    Denorm                    : constant Boolean := False;
 142    Duration_32_Bits          : constant Boolean := False;
 143    Exit_Status_Supported     : constant Boolean := True;
 144    Fractional_Fixed_Ops      : constant Boolean := False;
 145    Frontend_Layout           : constant Boolean := False;
 146    Functions_Return_By_DSP   : constant Boolean := False;
 147    Machine_Overflows         : constant Boolean := False;
 148    Machine_Rounds            : constant Boolean := True;
 149    OpenVMS                   : constant Boolean := True;
 150    Preallocated_Stacks       : constant Boolean := False;
 151    Signed_Zeros              : constant Boolean := True;
 152    Stack_Check_Default       : constant Boolean := True;
 153    Stack_Check_Probes        : constant Boolean := True;
 154    Support_64_Bit_Divides    : constant Boolean := True;
 155    Support_Aggregates        : constant Boolean := True;
 156    Support_Composite_Assign  : constant Boolean := True;
 157    Support_Composite_Compare : constant Boolean := True;
 158    Support_Long_Shifts       : constant Boolean := True;
 159    Suppress_Standard_Library : constant Boolean := False;
 160    Use_Ada_Main_Program_Name : constant Boolean := False;
 161    ZCX_By_Default            : constant Boolean := True;
 162    GCC_ZCX_Support           : constant Boolean := True;
 163    Front_End_ZCX_Support     : constant Boolean := False;
 164
 165    --  Obsolete entries, to be removed eventually (bootstrap issues!)
 166
 167    High_Integrity_Mode       : constant Boolean := False;
 168    Long_Shifts_Inlined       : constant Boolean := False;
 169
 170    --------------------------
 171    -- Underlying Priorities --
 172    ---------------------------
 173
 174    --  Important note: this section of the file must come AFTER the
 175    --  definition of the system implementation parameters to ensure
 176    --  that the value of these parameters is available for analysis
 177    --  of the declarations here (using Rtsfind at compile time).
 178
 179    --  The underlying priorities table provides a generalized mechanism
 180    --  for mapping from Ada priorities to system priorities. In some
 181    --  cases a 1-1 mapping is not the convenient or optimal choice.
 182
 183    --  For DEC Threads OpenVMS, we use the full range of 31 priorities
 184    --  in the Ada model, but map them by compression onto the more limited
 185    --  range of priorities available in OpenVMS.
 186
 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 with the command:
 190
 191    --     $ gcc -c -O3 -gnatpgn system.ads
 192
 193    --  then recompile the run-time parts that depend on this package:
 194
 195    --     $ gnatmake -a -gnatn -O3 <your application>
 196
 197    --  then force rebuilding your application if you need different options:
 198
 199    --     $ gnatmake -f <your options> <your application>
 200
 201    type Priorities_Mapping is array (Any_Priority) of Integer;
 202    pragma Suppress_Initialization (Priorities_Mapping);
 203    --  Suppress initialization in case gnat.adc specifies Normalize_Scalars
 204
 205    Underlying_Priorities : constant Priorities_Mapping :=
 206
 207      (Priority'First => 16,
 208
 209       1  => 17,
 210       2  => 18,
 211       3  => 18,
 212       4  => 18,
 213       5  => 18,
 214       6  => 19,
 215       7  => 19,
 216       8  => 19,
 217       9  => 20,
 218       10 => 20,
 219       11 => 21,
 220       12 => 21,
 221       13 => 22,
 222       14 => 23,
 223
 224       Default_Priority   => 24,
 225
 226       16 => 25,
 227       17 => 25,
 228       18 => 25,
 229       19 => 26,
 230       20 => 26,
 231       21 => 26,
 232       22 => 27,
 233       23 => 27,
 234       24 => 27,
 235       25 => 28,
 236       26 => 28,
 237       27 => 29,
 238       28 => 29,
 239       29 => 30,
 240
 241       Priority'Last      => 30,
 242
 243       Interrupt_Priority => 31);
 244
 245    ----------------------------
 246    -- Special VMS Interfaces --
 247    ----------------------------
 248
 249    procedure Lib_Stop (I : in Integer);
 250    pragma Interface (C, Lib_Stop);
 251    pragma Import_Procedure (Lib_Stop, "LIB$STOP", Mechanism => (Value));
 252    --  Interface to VMS condition handling. Used by RTSfind and pragma
 253    --  {Import,Export}_Exception. Put here because this is the only
 254    --  VMS specific package that doesn't drag in tasking.
 255
 256 end System;