File : system-linux-x86_64.ads


   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                        GNAT RUN-TIME COMPONENTS                          --
   4 --                                                                          --
   5 --                               S Y S T E M                                --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                       (GNU-Linux/x86-64 Version)                         --
   9 --                                                                          --
  10 --          Copyright (C) 1992-2015, 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 --                                                                          --
  24 --                                                                          --
  25 --                                                                          --
  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    pragma No_Elaboration_Code_All;
  44    --  Allow the use of that restriction in units that WITH this unit
  45 
  46    type Name is (SYSTEM_NAME_GNAT);
  47    System_Name : constant Name := SYSTEM_NAME_GNAT;
  48 
  49    --  System-Dependent Named Numbers
  50 
  51    Min_Int               : constant := Long_Long_Integer'First;
  52    Max_Int               : constant := Long_Long_Integer'Last;
  53 
  54    Max_Binary_Modulus    : constant := 2 ** Long_Long_Integer'Size;
  55    Max_Nonbinary_Modulus : constant := 2 ** Integer'Size - 1;
  56 
  57    Max_Base_Digits       : constant := Long_Long_Float'Digits;
  58    Max_Digits            : constant := Long_Long_Float'Digits;
  59 
  60    Max_Mantissa          : constant := 63;
  61    Fine_Delta            : constant := 2.0 ** (-Max_Mantissa);
  62 
  63    Tick                  : constant := 0.000_001;
  64 
  65    --  Storage-related Declarations
  66 
  67    type Address is private;
  68    pragma Preelaborable_Initialization (Address);
  69    Null_Address : constant Address;
  70 
  71    Storage_Unit : constant := 8;
  72    Word_Size    : constant := Standard'Word_Size;
  73    Memory_Size  : constant := 2 ** Word_Size;
  74 
  75    --  Address comparison
  76 
  77    function "<"  (Left, Right : Address) return Boolean;
  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 
  83    pragma Import (Intrinsic, "<");
  84    pragma Import (Intrinsic, "<=");
  85    pragma Import (Intrinsic, ">");
  86    pragma Import (Intrinsic, ">=");
  87    pragma Import (Intrinsic, "=");
  88 
  89    --  Other System-Dependent Declarations
  90 
  91    type Bit_Order is (High_Order_First, Low_Order_First);
  92    Default_Bit_Order : constant Bit_Order := Low_Order_First;
  93    pragma Warnings (Off, Default_Bit_Order); -- kill constant condition warning
  94 
  95    --  Priority-related Declarations (RM D.1)
  96 
  97    --  0 .. 98 corresponds to the system priority range 1 .. 99.
  98    --
  99    --  If the scheduling policy is SCHED_FIFO or SCHED_RR the runtime makes use
 100    --  of the entire range provided by the system.
 101    --
 102    --  If the scheduling policy is SCHED_OTHER the only valid system priority
 103    --  is 1 and other values are simply ignored.
 104 
 105    Max_Priority           : constant Positive := 97;
 106    Max_Interrupt_Priority : constant Positive := 98;
 107 
 108    subtype Any_Priority       is Integer      range  0 .. 98;
 109    subtype Priority           is Any_Priority range  0 .. 97;
 110    subtype Interrupt_Priority is Any_Priority range 98 .. 98;
 111 
 112    Default_Priority : constant Priority := 48;
 113 
 114 private
 115 
 116    type Address is mod Memory_Size;
 117    Null_Address : constant Address := 0;
 118 
 119    --------------------------------------
 120    -- System Implementation Parameters --
 121    --------------------------------------
 122 
 123    --  These parameters provide information about the target that is used
 124    --  by the compiler. They are in the private part of System, where they
 125    --  can be accessed using the special circuitry in the Targparm unit
 126    --  whose source should be consulted for more detailed descriptions
 127    --  of the individual switch values.
 128 
 129    Backend_Divide_Checks     : constant Boolean := False;
 130    Backend_Overflow_Checks   : constant Boolean := True;
 131    Command_Line_Args         : constant Boolean := True;
 132    Configurable_Run_Time     : constant Boolean := False;
 133    Denorm                    : constant Boolean := True;
 134    Duration_32_Bits          : constant Boolean := False;
 135    Exit_Status_Supported     : constant Boolean := True;
 136    Fractional_Fixed_Ops      : constant Boolean := False;
 137    Frontend_Layout           : constant Boolean := False;
 138    Machine_Overflows         : constant Boolean := False;
 139    Machine_Rounds            : constant Boolean := True;
 140    Preallocated_Stacks       : constant Boolean := False;
 141    Signed_Zeros              : constant Boolean := True;
 142    Stack_Check_Default       : constant Boolean := False;
 143    Stack_Check_Probes        : constant Boolean := True;
 144    Stack_Check_Limits        : constant Boolean := False;
 145    Support_Aggregates        : constant Boolean := True;
 146    Support_Atomic_Primitives : constant Boolean := True;
 147    Support_Composite_Assign  : constant Boolean := True;
 148    Support_Composite_Compare : constant Boolean := True;
 149    Support_Long_Shifts       : constant Boolean := True;
 150    Always_Compatible_Rep     : constant Boolean := False;
 151    Suppress_Standard_Library : constant Boolean := False;
 152    Use_Ada_Main_Program_Name : constant Boolean := False;
 153    Frontend_Exceptions       : constant Boolean := False;
 154    ZCX_By_Default            : constant Boolean := True;
 155 
 156 end System;