Geek Gadgets 1/ADE-1.bin/ade-bin/lib/gcc-lib/m68k-amigaos/2.7.2.1/adainclude/a-tiwtio.adb

Text File | 1995-10-17 | 28.0 KB | 1,095 lines

------------------------------------------------------------------------------
--                                                                          --
--                         GNAT RUNTIME COMPONENTS                          --
--                                                                          --
--             A D A . T E X T _ I O . W I D E _ T E X T _ I O              --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--                            $Revision: 1.7 $                              --
--                                                                          --
--        Copyright (c) 1992,1993,1994,1995 NYU, All Rights Reserved        --
--                                                                          --
-- The GNAT library is free software; you can redistribute it and/or modify --
-- it under terms of the GNU Library General Public License as published by --
-- the Free Software  Foundation; either version 2, or (at your option) any --
-- later version.  The GNAT library is distributed in the hope that it will --
-- be useful, but WITHOUT ANY WARRANTY;  without even  the implied warranty --
-- of MERCHANTABILITY  or  FITNESS FOR  A PARTICULAR PURPOSE.  See the  GNU --
-- Library  General  Public  License for  more  details.  You  should  have --
-- received  a copy of the GNU  Library  General Public License  along with --
-- the GNAT library;  see the file  COPYING.LIB.  If not, write to the Free --
-- Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.        --
--                                                                          --
------------------------------------------------------------------------------

with Ada.Streams;          use Ada.Streams;
with Interfaces.C_Streams; use Interfaces.C_Streams;
with System;
with System.File_IO;
with System.WCh_Cnv;       use System.WCh_Cnv;
with System.WCh_Con;       use System.WCh_Con;
with Unchecked_Conversion;
with Unchecked_Deallocation;

pragma Elaborate_All (System.File_IO);
--  Needed because of calls to Chain_File in package body elaboration

package body Ada.Text_IO.Wide_Text_IO is

   package FIO renames System.File_IO;
   package TIO renames Ada.Text_IO;

   subtype AP is FCB.AFCB_Ptr;

   function To_FCB is new Unchecked_Conversion (File_Mode, FCB.File_Mode);
   function To_TIO is new Unchecked_Conversion (FCB.File_Mode, File_Mode);

   -----------------------
   -- Local Subprograms --
   -----------------------

   function Get_Wide_Char
     (C    : Character;
      File : File_Type)
      return Wide_Character;
   --  This function is shared by Get and Get_Immediate to extract a wide
   --  character value from the given File. The first byte has already been
   --  read and is passed in C. The wide character value is returned as the
   --  result, and the file pointer is bumped past the character.

   -------------------
   -- AFCB_Allocate --
   -------------------

   function AFCB_Allocate
     (Control_Block : Wide_Text_AFCB)
      return          FCB.AFCB_Ptr
   is
   begin
      return new Wide_Text_AFCB;
   end AFCB_Allocate;

   ----------------
   -- AFCB_Close --
   ----------------

   procedure AFCB_Close (File : access Wide_Text_AFCB) is
   begin
      --  If the file being closed is one of the current files, then close
      --  the corresponding current file. It is not clear that this action
      --  is required (RM A.10.3(23)) but it seems reasonable, and besides
      --  ACVC test CE3208A expects this behavior).

      if File = Current_In then
         Current_In := null;
      elsif File = Current_Out then
         Current_Out := null;
      elsif File = Current_Err then
         Current_Err := null;
      end if;

      --  Output line terminator if needed, but page terminator is implied

      if File.Mode /= FCB.In_File and then File.Col /= 1 then
         New_Line (File);
      end if;
   end AFCB_Close;

   ---------------
   -- AFCB_Free --
   ---------------

   procedure AFCB_Free (File : access Wide_Text_AFCB) is
      type FCB_Ptr is access all Wide_Text_AFCB;
      FT : FCB_Ptr := File;

      procedure Free is new
        Unchecked_Deallocation (Wide_Text_AFCB, FCB_Ptr);

   begin
      Free (FT);
   end AFCB_Free;

   -----------
   -- Close --
   -----------

   procedure Close (File : in out File_Type) is
   begin
      FIO.Close (AP (File));
   end Close;

   ---------
   -- Col --
   ---------

   --  Note: we assume that it is impossible in practice for the column
   --  to exceed the value of Count'Last, i.e. no check is required for
   --  overflow raising layout error.

   function Col (File : in File_Type) return Positive_Count is
   begin
      return Positive_Count (TIO.Col (TIO.File_Type (File)));
   end Col;

   function Col return Positive_Count is
   begin
      return Col (Current_Out);
   end Col;

   ------------
   -- Create --
   ------------

   procedure Create
     (File : in out File_Type;
      Mode : in File_Mode := Out_File;
      Name : in String := "";
      Form : in String := "")
   is
      File_Control_Block : Wide_Text_AFCB;

   begin
      FIO.Open (File_Ptr  => AP (File),
                Dummy_FCB => File_Control_Block,
                Mode      => To_FCB (Mode),
                Name      => Name,
                Form      => Form,
                Amethod   => 'W',
                Creat     => True,
                Text      => True);

      Setup (File);
   end Create;

   -------------------
   -- Current_Error --
   -------------------

   function Current_Error return File_Type is
   begin
      return Current_Err;
   end Current_Error;

   function Current_Error return File_Access is
   begin
      return Current_Err'Access;
   end Current_Error;

   -------------------
   -- Current_Input --
   -------------------

   function Current_Input return File_Type is
   begin
      return Current_In;
   end Current_Input;

   function Current_Input return File_Access is
   begin
      return Current_In'Access;
   end Current_Input;

   --------------------
   -- Current_Output --
   --------------------

   function Current_Output return File_Type is
   begin
      return Current_Out;
   end Current_Output;

   function Current_Output return File_Access is
   begin
      return Current_Out'Access;
   end Current_Output;

   ------------
   -- Delete --
   ------------

   procedure Delete (File : in out File_Type) is
   begin
      FIO.Delete (AP (File));
   end Delete;

   -----------------
   -- End_Of_File --
   -----------------

   function End_Of_File (File : in File_Type) return Boolean is
   begin
      return TIO.End_Of_File (TIO.File_Type (File));
   end End_Of_File;

   function End_Of_File return Boolean is
   begin
      return TIO.End_Of_File (TIO.File_Type (Current_In));
   end End_Of_File;

   -----------------
   -- End_Of_Line --
   -----------------

   function End_Of_Line (File : in File_Type) return Boolean is
   begin
      FIO.Check_Read_Status (AP (File));

      if File.Before_Wide_Character then
         return False;
      else
         return TIO.End_Of_Line (TIO.File_Type (File));
      end if;
   end End_Of_Line;

   function End_Of_Line return Boolean is
   begin
      return End_Of_Line (Current_In);
   end End_Of_Line;

   -----------------
   -- End_Of_Page --
   -----------------

   function End_Of_Page (File : in File_Type) return Boolean is
   begin
      FIO.Check_Read_Status (AP (File));

      if File.Before_Wide_Character then
         return False;
      else
         return TIO.End_Of_Page (TIO.File_Type (File));
      end if;
   end End_Of_Page;

   function End_Of_Page return Boolean is
   begin
      return End_Of_Page (Current_In);
   end End_Of_Page;

   -----------
   -- Flush --
   -----------

   procedure Flush (File : in out File_Type) is
   begin
      FIO.Flush (AP (File));
   end Flush;

   procedure Flush is
   begin
      Flush (Current_Out);
   end Flush;

   ----------
   -- Form --
   ----------

   function Form (File : in File_Type) return String is
   begin
      return FIO.Form (AP (File));
   end Form;

   ---------
   -- Get --
   ---------

   procedure Get
     (File : in File_Type;
      Item : out Wide_Character)
   is
      C  : Character;

   begin
      FIO.Check_Read_Status (AP (File));

      if File.Before_Wide_Character then
         File.Before_Wide_Character := False;
         Item := File.Saved_Wide_Character;

      else
         TIO.Get (TIO.File_Type (File), C);
         Item := Get_Wide_Char (C, File);
      end if;
   end Get;

   procedure Get (Item : out Wide_Character) is
   begin
      Get (Current_In, Item);
   end Get;

   procedure Get
     (File : in File_Type;
      Item : out Wide_String)
   is
   begin
      for J in Item'Range loop
         Get (File, Item (J));
      end loop;
   end Get;

   procedure Get (Item : out Wide_String) is
   begin
      Get (Current_In, Item);
   end Get;

   -------------------
   -- Get_Immediate --
   -------------------

   --  More work required here ???

   procedure Get_Immediate
     (File : in File_Type;
      Item : out Wide_Character)
   is
      ch : int;

   begin
      FIO.Check_Read_Status (AP (File));

      if File.Before_Wide_Character then
         File.Before_Wide_Character := False;
         Item := File.Saved_Wide_Character;

      elsif File.Before_LM then
         File.Before_LM := False;
         File.Before_LM_PM := False;
         Item := Wide_Character'Val (LM);

      else
         ch := Getc (TIO.File_Type (File));

         if ch = EOF then
            raise End_Error;
         else
            Item := Get_Wide_Char (Character'Val (ch), File);
         end if;
      end if;
   end Get_Immediate;

   procedure Get_Immediate
     (Item : out Wide_Character)
   is
   begin
      Get_Immediate (Current_In, Item);
   end Get_Immediate;

   procedure Get_Immediate
     (File      : in File_Type;
      Item      : out Wide_Character;
      Available : out Boolean)
   is
      ch : int;

   begin
      FIO.Check_Read_Status (AP (File));
      Available := True;

      if File.Before_Wide_Character then
         File.Before_Wide_Character := False;
         Item := File.Saved_Wide_Character;

      elsif File.Before_LM then
         File.Before_LM := False;
         File.Before_LM_PM := False;
         Item := Wide_Character'Val (LM);

      else
         ch := Getc (TIO.File_Type (File));

         if ch = EOF then
            raise End_Error;
         else
            Item := Get_Wide_Char (Character'Val (ch), File);
         end if;
      end if;
   end Get_Immediate;

   procedure Get_Immediate
     (Item      : out Wide_Character;
      Available : out Boolean)
   is
   begin
      Get_Immediate (Current_In, Item, Available);
   end Get_Immediate;

   --------------
   -- Get_Line --
   --------------

   procedure Get_Line
     (File : in File_Type;
      Item : out Wide_String;
      Last : out Natural)
   is
   begin
      FIO.Check_Read_Status (AP (File));
      Last := Item'First - 1;

      --  Immediate exit for null string, this is a case in which we do not
      --  need to test for end of file and we do not skip a line mark under
      --  any circumstances.

      if Last >= Item'Last then
         return;
      end if;

      --  Here we have at least one character, if we are immediately before
      --  a line mark, then we will just skip past it storing no characters.

      if File.Before_LM then
         File.Before_LM := False;
         File.Before_LM_PM := False;

      --  Otherwise we need to read some characters

      else
         --  If we are at the end of file now, it means we are trying to
         --  skip a file terminator and we raise End_Error (RM A.10.7(20))

         if Nextc (TIO.File_Type (File)) = EOF then
            raise End_Error;
         end if;

         --  Loop through characters in string

         loop
            --  Exit the loop if read is terminated by encountering line mark
            --  Note that the use of Skip_Line here ensures we properly deal
            --  with setting the page and line numbers.

            if End_Of_Line (File) then
               Skip_Line (File);
               return;
            end if;

            --  Otherwise store the character, note that we know that ch is
            --  something other than LM or EOF. It could possibly be a page
            --  mark if there is a stray page mark in the middle of a line,
            --  but this is not an official page mark in any case, since
            --  official page marks can only follow a line mark. The whole
            --  page business is pretty much nonsense anyway, so we do not
            --  want to waste time trying to make sense out of non-standard
            --  page marks in the file! This means that the behavior of
            --  Get_Line is different from repeated Get of a character, but
            --  that's too bad. We only promise that page numbers etc make
            --  sense if the file is formatted in a standard manner.

            --  Note: we do not adjust the column number because it is quicker
            --  to adjust it once at the end of the operation than incrementing
            --  it each time around the loop.

            Last := Last + 1;
            Get (File, Item (Last));

            --  All done if the string is full, this is the case in which
            --  we do not skip the following line mark. We need to adjust
            --  the column number in this case.

            if Last = Item'Last then
               File.Col := File.Col + TIO.Count (Item'Length);
               return;
            end if;

            --  Exit from the loop if we are at the end of file. This happens
            --  if we have a last line that is not terminated with a line mark.
            --  In this case we consider that there is an implied line mark;
            --  this is a non-standard file, but we will treat it nicely.

            exit when Nextc (TIO.File_Type (File)) = EOF;
         end loop;
      end if;
   end Get_Line;

   procedure Get_Line
     (Item : out Wide_String;
      Last : out Natural)
   is
   begin
      Get_Line (Current_In, Item, Last);
   end Get_Line;

   -------------------
   -- Get_Wide_Char --
   -------------------

   function Get_Wide_Char
     (C    : Character;
      File : File_Type)
      return Wide_Character
   is
      function In_Char return Character;
      --  Function used to obtain additional characters it the wide character
      --  sequence is more than one character long.

      function In_Char return Character is
         ch : constant Integer := Getc (TIO.File_Type (File));

      begin
         if ch = EOF then
            raise End_Error;
         else
            return Character'Val (ch);
         end if;
      end In_Char;

      function WC_In is new Char_Sequence_To_Wide_Char (In_Char);

   begin
      return WC_In (C, File.WC_Method);
   end Get_Wide_Char;

   -------------
   -- Is_Open --
   -------------

   function Is_Open (File : in File_Type) return Boolean is
   begin
      return FIO.Is_Open (AP (File));
   end Is_Open;

   ----------
   -- Line --
   ----------

   --  Note: we assume that it is impossible in practice for the line
   --  to exceed the value of Count'Last, i.e. no check is required for
   --  overflow raising layout error.

   function Line (File : in File_Type) return Positive_Count is
   begin
      return Positive_Count (TIO.Line (TIO.File_Type (File)));
   end Line;

   function Line return Positive_Count is
   begin
      return Line (Current_Out);
   end Line;

   -----------------
   -- Line_Length --
   -----------------

   function Line_Length (File : in File_Type) return Count is
   begin
      return Count (TIO.Line_Length (TIO.File_Type (File)));
   end Line_Length;

   function Line_Length return Count is
   begin
      return Line_Length (Current_Out);
   end Line_Length;

   ----------------
   -- Look_Ahead --
   ----------------

   procedure Look_Ahead
     (File        : in File_Type;
      Item        : out Wide_Character;
      End_Of_Line : out Boolean)
   is
      ch : int;
      WC : Wide_Character;

   --  Start of processing for Look_Ahead

   begin
      FIO.Check_Read_Status (AP (File));

      --  If we are logically before a line mark, we can return immediately

      if File.Before_LM then
         End_Of_Line := True;
         Item := Wide_Character'Val (0);

      --  If we are before a wide character, just return it (this happens
      --  if there are two calls to Look_Ahead in a row).

      elsif File.Before_Wide_Character then
         End_Of_Line := False;
         Item := File.Saved_Wide_Character;

      --  otherwise we must read a character from the input stream

      else
         ch := Getc (TIO.File_Type (File));

         if ch = LM
           or else ch = EOF
           or else (ch = EOF and then File.Is_Regular_File)
         then
            End_Of_Line := True;
            Ungetc (ch, TIO.File_Type (File));
            Item := Wide_Character'Val (0);

         --  If the character is in the range 16#0000# to 16#007F# it stands
         --  for itself and occupies a single byte, so we can unget it with
         --  no difficulty.

         elsif ch <= 16#0080# then
            End_Of_Line := False;
            Ungetc (ch, TIO.File_Type (File));
            Item := Wide_Character'Val (ch);

         --  For a character above this range, we read the character, using
         --  the Get_Wide_Char routine. It may well occupy more than one byte
         --  so we can't put it back with ungetc. Instead we save it in the
         --  control block, setting a flag that everyone interested in reading
         --  characters must test before reading the stream.

         else
            Item := Get_Wide_Char (Character'Val (ch), File);
            End_Of_Line := False;
            File.Saved_Wide_Character := Item;
            File.Before_Wide_Character := True;
         end if;
      end if;
   end Look_Ahead;

   procedure Look_Ahead
     (Item        : out Wide_Character;
      End_Of_Line : out Boolean)
   is
   begin
      Look_Ahead (Standard_In, Item, End_Of_Line);
   end Look_Ahead;

   ----------
   -- Mode --
   ----------

   function Mode (File : in File_Type) return File_Mode is
   begin
      return To_TIO (FIO.Mode (AP (File)));
   end Mode;

   ----------
   -- Name --
   ----------

   function Name (File : in File_Type) return String is
   begin
      return FIO.Name (AP (File));
   end Name;

   --------------
   -- New_Line --
   --------------

   procedure New_Line
     (File    : in File_Type;
      Spacing : in Positive_Count := 1)
   is
   begin
      TIO.New_Line (TIO.File_Type (File), TIO.Positive_Count (Spacing));
   end New_Line;

   procedure New_Line (Spacing : in Positive_Count := 1) is
   begin
      New_Line (Current_Out, Spacing);
   end New_Line;

   --------------
   -- New_Page --
   --------------

   procedure New_Page (File : in File_Type) is
   begin
      TIO.New_Page (TIO.File_Type (File));
   end New_Page;

   procedure New_Page is
   begin
      New_Page (Current_Out);
   end New_Page;

   ----------
   -- Open --
   ----------

   procedure Open
     (File : in out File_Type;
      Mode : in File_Mode;
      Name : in String;
      Form : in String := "")
   is
      File_Control_Block : Wide_Text_AFCB;

   begin
      FIO.Open (File_Ptr  => AP (File),
                Dummy_FCB => File_Control_Block,
                Mode      => To_FCB (Mode),
                Name      => Name,
                Form      => Form,
                Amethod   => 'T',
                Creat     => False,
                Text      => True);

      Setup (File);
   end Open;

   ----------
   -- Page --
   ----------

   --  Note: we assume that it is impossible in practice for the page
   --  to exceed the value of Count'Last, i.e. no check is required for
   --  overflow raising layout error.

   function Page (File : in File_Type) return Positive_Count is
   begin
      return Positive_Count (TIO.Page (TIO.File_Type (File)));
   end Page;

   function Page return Positive_Count is
   begin
      return Page (Current_Out);
   end Page;

   -----------------
   -- Page_Length --
   -----------------

   function Page_Length (File : in File_Type) return Count is
   begin
      return Count (TIO.Page_Length (TIO.File_Type (File)));
   end Page_Length;

   function Page_Length return Count is
   begin
      return Page_Length (Current_Out);
   end Page_Length;

   ---------
   -- Put --
   ---------

   procedure Put
     (File : in File_Type;
      Item : in Wide_Character)
   is
      procedure Out_Char (C : Character);
      --  Procedure to output one character of a wide character sequence

      procedure Out_Char (C : Character) is
      begin
         Putc (Character'Pos (C), TIO.File_Type (File));
      end Out_Char;

      procedure WC_Out is new Wide_Char_To_Char_Sequence (Out_Char);

   begin
      WC_Out (Item, File.WC_Method);
      File.Col := File.Col + 1;
   end Put;

   procedure Put (Item : in Wide_Character) is
   begin
      Put (Current_Out, Item);
   end Put;

   ---------
   -- Put --
   ---------

   procedure Put
     (File : in File_Type;
      Item : in Wide_String)
   is
   begin
      for J in Item'Range loop
         Put (File, Item (J));
      end loop;
   end Put;

   procedure Put (Item : in Wide_String) is
   begin
      Put (Current_Out, Item);
   end Put;

   --------------
   -- Put_Line --
   --------------

   procedure Put_Line
     (File : in File_Type;
      Item : in Wide_String)
   is
   begin
      Put (File, Item);
      New_Line (File);
   end Put_Line;

   procedure Put_Line (Item : in Wide_String) is
   begin
      Put (Current_Out, Item);
      New_Line (Current_Out);
   end Put_Line;

   -----------
   -- Reset --
   -----------

   procedure Reset
     (File : in out File_Type;
      Mode : in File_Mode)
   is
      function To_TIO_Mode is
        new Unchecked_Conversion (File_Mode, TIO.File_Mode);

   begin
      TIO.Reset (TIO.File_Type (File), To_TIO_Mode (Mode));
      File.Before_Wide_Character := False;
   end Reset;

   procedure Reset (File : in out File_Type) is
   begin
      TIO.Reset (TIO.File_Type (File));
      File.Before_Wide_Character := False;
   end Reset;

   -------------
   -- Set_Col --
   -------------

   procedure Set_Col
     (File : in File_Type;
      To   : in Positive_Count)
   is
   begin
      TIO.Set_Col (TIO.File_Type (File), TIO.Positive_Count (To));
   end Set_Col;

   procedure Set_Col (To : in Positive_Count) is
   begin
      Set_Col (Current_Out, To);
   end Set_Col;

   ---------------
   -- Set_Error --
   ---------------

   procedure Set_Error (File : in File_Type) is
   begin
      FIO.Check_Write_Status (AP (File));
      Current_Err := File;
   end Set_Error;

   ---------------
   -- Set_Input --
   ---------------

   procedure Set_Input (File : in File_Type) is
   begin
      FIO.Check_Read_Status (AP (File));
      Current_In := File;
   end Set_Input;

   --------------
   -- Set_Line --
   --------------

   procedure Set_Line
     (File : in File_Type;
      To   : in Positive_Count)
   is
   begin
      TIO.Set_Line (TIO.File_Type (File), TIO.Positive_Count (To));
      File.Before_Wide_Character := False;
   end Set_Line;

   procedure Set_Line (To : in Positive_Count) is
   begin
      Set_Line (Current_Out, To);
   end Set_Line;

   ---------------------
   -- Set_Line_Length --
   ---------------------

   procedure Set_Line_Length (File : in File_Type; To : in Count) is
   begin
      TIO.Set_Line_Length (TIO.File_Type (File), TIO.Count (To));
   end Set_Line_Length;

   procedure Set_Line_Length (To : in Count) is
   begin
      Set_Line_Length (Current_Out, To);
   end Set_Line_Length;

   ----------------
   -- Set_Output --
   ----------------

   procedure Set_Output (File : in File_Type) is
   begin
      FIO.Check_Write_Status (AP (File));
      Current_Out := File;
   end Set_Output;

   ---------------------
   -- Set_Page_Length --
   ---------------------

   procedure Set_Page_Length (File : in File_Type; To : in Count) is
   begin
      TIO.Set_Page_Length (TIO.File_Type (File), TIO.Count (To));
   end Set_Page_Length;

   procedure Set_Page_Length (To : in Count) is
   begin
      Set_Page_Length (Current_Out, To);
   end Set_Page_Length;

   -----------
   -- Setup --
   -----------

   procedure Setup (File : File_Type) is
      Start, Stop : Natural;

   begin
      FIO.Form_Parameter (File.Form.all, "wcem", Start, Stop);

      if Start = 0 then
         null;

      elsif Start /= Stop then
         raise Use_Error;

      else
         for J in WC_Encoding_Method loop
            if File.Form (Start) = WC_Encoding_Letters (J) then
               File.WC_Method := J;
               return;
            end if;
         end loop;

         raise Use_Error;
      end if;

   end Setup;

   ---------------
   -- Skip_Line --
   ---------------

   procedure Skip_Line
     (File    : in File_Type;
      Spacing : in Positive_Count := 1)
   is
   begin
      TIO.Skip_Line (TIO.File_Type (File), TIO.Positive_Count (Spacing));
      File.Before_Wide_Character := False;
   end Skip_Line;

   procedure Skip_Line (Spacing : in Positive_Count := 1) is
   begin
      Skip_Line (Current_In, Spacing);
   end Skip_Line;

   ---------------
   -- Skip_Page --
   ---------------

   procedure Skip_Page (File : in File_Type) is
   begin
      TIO.Skip_Page (TIO.File_Type (File));
      File.Before_Wide_Character := False;
   end Skip_Page;

   procedure Skip_Page is
   begin
      Skip_Page (Current_In);
   end Skip_Page;

   --------------------
   -- Standard_Error --
   --------------------

   function Standard_Error return File_Type is
   begin
      return Standard_Err;
   end Standard_Error;

   function Standard_Error return File_Access is
   begin
      return Standard_Err'Access;
   end Standard_Error;

   --------------------
   -- Standard_Input --
   --------------------

   function Standard_Input return File_Type is
   begin
      return Standard_In;
   end Standard_Input;

   function Standard_Input return File_Access is
   begin
      return Standard_In'Access;
   end Standard_Input;

   ---------------------
   -- Standard_Output --
   ---------------------

   function Standard_Output return File_Type is
   begin
      return Standard_Out;
   end Standard_Output;

   function Standard_Output return File_Access is
   begin
      return Standard_Out'Access;
   end Standard_Output;

begin
   -------------------------------
   -- Initialize Standard Files --
   -------------------------------

   --  Note: the names in these files are bogus, and probably it would be
   --  better for these files to have no names, but the ACVC test insist!
   --  We use names that are bound to fail in open etc.

   Standard_In.Stream             := stdin;
   Standard_In.Name               := new String'("*stdin");
   Standard_In.Form               := Null_Str'Access;
   Standard_In.Mode               := FCB.In_File;
   Standard_In.Is_Regular_File    := is_regular_file (fileno (stdin)) /= 0;
   Standard_In.Is_Temporary_File  := False;
   Standard_In.Is_System_File     := True;
   Standard_In.Is_Text_File       := True;
   Standard_In.Access_Method      := 'W';

   Standard_Out.Stream            := stdout;
   Standard_Out.Name              := new String'("*stdout");
   Standard_Out.Form              := Null_Str'Access;
   Standard_Out.Mode              := FCB.Out_File;
   Standard_Out.Is_Regular_File   := is_regular_file (fileno (stdout)) /= 0;
   Standard_Out.Is_Temporary_File := False;
   Standard_Out.Is_System_File    := True;
   Standard_Out.Is_Text_File      := True;
   Standard_Out.Access_Method     := 'W';

   Standard_Err.Stream            := stderr;
   Standard_Err.Name              := new String'("*stderr");
   Standard_Err.Form              := Null_Str'Access;
   Standard_Err.Mode              := FCB.Out_File;
   Standard_Err.Is_Regular_File   := is_regular_file (fileno (stderr)) /= 0;
   Standard_Err.Is_Temporary_File := False;
   Standard_Err.Is_System_File    := True;
   Standard_Err.Is_Text_File      := True;
   Standard_Err.Access_Method     := 'W';

   FIO.Chain_File (AP (Standard_In));
   FIO.Chain_File (AP (Standard_Out));
   FIO.Chain_File (AP (Standard_Err));

end Ada.Text_IO.Wide_Text_IO;