gcc/ada/system.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                        GNAT RUN-TIME COMPONENTS                          --
   4 --                                                                          --
   5 --                               S Y S T E M                                --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                            (Compiler Version)                            --
   9 --                                                                          --
  10 --          Copyright (C) 1992-2005 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,  51  Franklin  Street,  Fifth  Floor, --
  25 -- Boston, MA 02110-1301, 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 --  This version of System is a generic version that is used in building
  40 --  the compiler. Right now, we have a host/target problem if we try to
  41 --  use the "proper" System, and since the compiler itself does not care
  42 --  about most System parameters, this generic version works fine.
  43
  44 package System is
  45    pragma Pure;
  46    --  Note that we take advantage of the implementation permission to make
  47    --  this unit Pure instead of Preelaborable; see RM 13.7.1(15). In Ada
  48    --  2005, this is Pure in any case (AI-362).
  49
  50    type Name is (SYSTEM_NAME_GNAT);
  51    System_Name : constant Name := SYSTEM_NAME_GNAT;
  52
  53    --  System-Dependent Named Numbers
  54
  55    Min_Int               : constant := Long_Long_Integer'First;
  56    Max_Int               : constant := Long_Long_Integer'Last;
  57
  58    Max_Binary_Modulus    : constant := 2 ** Long_Long_Integer'Size;
  59    Max_Nonbinary_Modulus : constant := Integer'Last;
  60
  61    Max_Base_Digits       : constant := Long_Long_Float'Digits;
  62    Max_Digits            : constant := Long_Long_Float'Digits;
  63
  64    Max_Mantissa          : constant := 63;
  65    Fine_Delta            : constant := 2.0 ** (-Max_Mantissa);
  66
  67    Tick                  : constant := 0.01;
  68
  69    --  Storage-related Declarations
  70
  71    type Address is private;
  72    Null_Address : constant Address;
  73
  74    Storage_Unit : constant := Standard'Storage_Unit;
  75    Word_Size    : constant := Standard'Word_Size;
  76    Memory_Size  : constant := 2 ** Standard'Address_Size;
  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    --  Other System-Dependent Declarations
  93
  94    type Bit_Order is (High_Order_First, Low_Order_First);
  95    Default_Bit_Order : constant Bit_Order :=
  96                          Bit_Order'Val (Standard'Default_Bit_Order);
  97
  98    --  Priority-related Declarations (RM D.1)
  99
 100    Max_Priority           : constant Positive := 30;
 101    Max_Interrupt_Priority : constant Positive := 31;
 102
 103    subtype Any_Priority       is Integer      range  0 .. 31;
 104    subtype Priority           is Any_Priority range  0 .. 30;
 105    subtype Interrupt_Priority is Any_Priority range 31 .. 31;
 106
 107    Default_Priority : constant Priority := 15;
 108
 109 private
 110
 111    type Address is mod Memory_Size;
 112    Null_Address : constant Address := 0;
 113
 114    --------------------------------------
 115    -- System Implementation Parameters --
 116    --------------------------------------
 117
 118    --  These parameters provide information about the target that is used
 119    --  by the compiler. They are in the private part of System, where they
 120    --  can be accessed using the special circuitry in the Targparm unit
 121    --  whose source should be consulted for more detailed descriptions
 122    --  of the individual switch values.
 123
 124    --  This version of system.ads is used only for building the compiler.
 125    --  We really ought to use the proper target system (i.e. the one that
 126    --  corresponds to the host for the compiler), but that causes as yet
 127    --  unsolved makefile problems. For the most part the setting of these
 128    --  parameters is not too critical for the compiler version (e.g. we
 129    --  do not use floating-point anyway in the compiler).
 130
 131    AAMP                      : constant Boolean := False;
 132    Backend_Divide_Checks     : constant Boolean := False;
 133    Backend_Overflow_Checks   : constant Boolean := False;
 134    Command_Line_Args         : constant Boolean := True;
 135    Configurable_Run_Time     : constant Boolean := False;
 136    Denorm                    : constant Boolean := True;
 137    Duration_32_Bits          : constant Boolean := False;
 138    Exit_Status_Supported     : constant Boolean := True;
 139    Fractional_Fixed_Ops      : constant Boolean := False;
 140    Frontend_Layout           : constant Boolean := False;
 141    Functions_Return_By_DSP   : constant Boolean := False;
 142    Machine_Overflows         : constant Boolean := False;
 143    Machine_Rounds            : constant Boolean := True;
 144    OpenVMS                   : constant Boolean := False;
 145    Preallocated_Stacks       : constant Boolean := False;
 146    Signed_Zeros              : constant Boolean := True;
 147    Stack_Check_Default       : constant Boolean := False;
 148    Stack_Check_Probes        : constant Boolean := False;
 149    Support_64_Bit_Divides    : constant Boolean := True;
 150    Support_Aggregates        : constant Boolean := True;
 151    Support_Composite_Assign  : constant Boolean := True;
 152    Support_Composite_Compare : constant Boolean := True;
 153    Support_Long_Shifts       : constant Boolean := True;
 154    Suppress_Standard_Library : constant Boolean := False;
 155    Use_Ada_Main_Program_Name : constant Boolean := False;
 156    ZCX_By_Default            : constant Boolean := False;
 157    GCC_ZCX_Support           : constant Boolean := False;
 158    Front_End_ZCX_Support     : constant Boolean := False;
 159
 160    --  Obsolete entries, to be removed eventually (bootstrap issues!)
 161
 162    High_Integrity_Mode       : constant Boolean := False;
 163    Long_Shifts_Inlined       : constant Boolean := True;
 164
 165 end System;