gcc/ada/system-rtems.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) 1992-2009 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 --  This version of System is a RTEMS version that is used in building
  38 --  the compiler.  This is based as closely as possible on the generic
  39 --  version with the following exceptions:
  40 --      + priority definitions
  41
  42 package System is
  43    pragma Pure;
  44    --  Note that we take advantage of the implementation permission to make
  45    --  this unit Pure instead of Preelaborable; see RM 13.7.1(15). In Ada
  46    --  2005, this is Pure in any case (AI-362).
  47
  48    type Name is (SYSTEM_NAME_GNAT);
  49    System_Name : constant Name := SYSTEM_NAME_GNAT;
  50
  51    --  System-Dependent Named Numbers
  52
  53    Min_Int               : constant := Long_Long_Integer'First;
  54    Max_Int               : constant := Long_Long_Integer'Last;
  55
  56    Max_Binary_Modulus    : constant := 2 ** Long_Long_Integer'Size;
  57    Max_Nonbinary_Modulus : constant := Integer'Last;
  58
  59    Max_Base_Digits       : constant := Long_Long_Float'Digits;
  60    Max_Digits            : constant := Long_Long_Float'Digits;
  61
  62    Max_Mantissa          : constant := 63;
  63    Fine_Delta            : constant := 2.0 ** (-Max_Mantissa);
  64
  65    Tick                  : constant := 0.01;
  66
  67    --  Storage-related Declarations
  68
  69    type Address is private;
  70    Null_Address : constant Address;
  71
  72    Storage_Unit : constant := Standard'Storage_Unit;
  73    Word_Size    : constant := Standard'Word_Size;
  74    Memory_Size  : constant := 2 ** Standard'Address_Size;
  75
  76    --  Address comparison
  77
  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;
  82    function "="  (Left, Right : Address) return Boolean;
  83
  84    pragma Import (Intrinsic, "<");
  85    pragma Import (Intrinsic, "<=");
  86    pragma Import (Intrinsic, ">");
  87    pragma Import (Intrinsic, ">=");
  88    pragma Import (Intrinsic, "=");
  89
  90    --  Other System-Dependent Declarations
  91
  92    type Bit_Order is (High_Order_First, Low_Order_First);
  93    Default_Bit_Order : constant Bit_Order :=
  94                          Bit_Order'Val (Standard'Default_Bit_Order);
  95    pragma Warnings (Off, Default_Bit_Order); -- kill constant condition warning
  96
  97    --  Priority-related Declarations (RM D.1)
  98
  99    --  RTEMS POSIX threads support 256 priority levels with 255 being
 100    --  logically the most important. Levels 0 and 255 are reserved.
 101    --
 102    --  255        is reserved for RTEMS system tasks
 103    --  247 - 254  correspond to hardware interrupt levels 0 .. 7
 104    --  246        is a catchall default "interrupt" priority for signals,
 105    --             allowing higher priority than normal tasks, but lower than
 106    --             hardware priority levels.  Protected Object ceilings can
 107    --             override these values.
 108    --  245        is used by the Interrupt_Manager task
 109    --  0          is reserved for the RTEMS IDLE task and really should not
 110    --             be accessible from Ada but GNAT initializes
 111    --             Current_Priority to 0 so it must be valid
 112
 113    Max_Priority           : constant Positive := 244;
 114    Max_Interrupt_Priority : constant Positive := 254;
 115
 116    subtype Any_Priority       is Integer      range   0 .. 254;
 117    subtype Priority           is Any_Priority range   0 .. 244;
 118    subtype Interrupt_Priority is Any_Priority range 245 .. 254;
 119
 120    Default_Priority : constant Priority := 122;
 121
 122 private
 123
 124    type Address is mod Memory_Size;
 125    Null_Address : constant Address := 0;
 126
 127    --------------------------------------
 128    -- System Implementation Parameters --
 129    --------------------------------------
 130
 131    --  These parameters provide information about the target that is used
 132    --  by the compiler. They are in the private part of System, where they
 133    --  can be accessed using the special circuitry in the Targparm unit
 134    --  whose source should be consulted for more detailed descriptions
 135    --  of the individual switch values.
 136
 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 := True;
 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    Machine_Overflows         : constant Boolean := False;
 147    Machine_Rounds            : constant Boolean := True;
 148    Preallocated_Stacks       : constant Boolean := False;
 149    Signed_Zeros              : constant Boolean := True;
 150    Stack_Check_Default       : constant Boolean := False;
 151    Stack_Check_Probes        : constant Boolean := False;
 152    Support_64_Bit_Divides    : constant Boolean := True;
 153    Support_Aggregates        : 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    Suppress_Standard_Library : constant Boolean := False;
 158    Use_Ada_Main_Program_Name : constant Boolean := False;
 159    ZCX_By_Default            : constant Boolean := False;
 160    GCC_ZCX_Support           : constant Boolean := True;
 161
 162    --  One would think you did not have to define this but
 163    --  it is used in the run-time.
 164    OpenVMS                   : constant Boolean := False;
 165
 166 end System;