gcc/ada/s-sequio.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                 S Y S T E M . S E Q U E N T I A L _ I O                  --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2006, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 with System.File_IO;
  35 with Unchecked_Deallocation;
  36
  37 package body System.Sequential_IO is
  38
  39    subtype AP is FCB.AFCB_Ptr;
  40
  41    package FIO renames System.File_IO;
  42
  43    -------------------
  44    -- AFCB_Allocate --
  45    -------------------
  46
  47    function AFCB_Allocate
  48      (Control_Block : Sequential_AFCB) return FCB.AFCB_Ptr
  49    is
  50       pragma Warnings (Off, Control_Block);
  51
  52    begin
  53       return new Sequential_AFCB;
  54    end AFCB_Allocate;
  55
  56    ----------------
  57    -- AFCB_Close --
  58    ----------------
  59
  60    --  No special processing required for Sequential_IO close
  61
  62    procedure AFCB_Close (File : access Sequential_AFCB) is
  63       pragma Warnings (Off, File);
  64
  65    begin
  66       null;
  67    end AFCB_Close;
  68
  69    ---------------
  70    -- AFCB_Free --
  71    ---------------
  72
  73    procedure AFCB_Free (File : access Sequential_AFCB) is
  74
  75       type FCB_Ptr is access all Sequential_AFCB;
  76
  77       FT : FCB_Ptr := FCB_Ptr (File);
  78
  79       procedure Free is new
  80         Unchecked_Deallocation (Sequential_AFCB, FCB_Ptr);
  81
  82    begin
  83       Free (FT);
  84    end AFCB_Free;
  85
  86    ------------
  87    -- Create --
  88    ------------
  89
  90    procedure Create
  91      (File : in out File_Type;
  92       Mode : FCB.File_Mode := FCB.Out_File;
  93       Name : String := "";
  94       Form : String := "")
  95    is
  96       Dummy_File_Control_Block : Sequential_AFCB;
  97       pragma Warnings (Off, Dummy_File_Control_Block);
  98       --  Yes, we know this is never assigned a value, only the tag
  99       --  is used for dispatching purposes, so that's expected.
 100
 101    begin
 102       FIO.Open (File_Ptr  => AP (File),
 103                 Dummy_FCB => Dummy_File_Control_Block,
 104                 Mode      => Mode,
 105                 Name      => Name,
 106                 Form      => Form,
 107                 Amethod   => 'Q',
 108                 Creat     => True,
 109                 Text      => False);
 110    end Create;
 111
 112    ----------
 113    -- Open --
 114    ----------
 115
 116    procedure Open
 117      (File : in out File_Type;
 118       Mode : FCB.File_Mode;
 119       Name : String;
 120       Form : String := "")
 121    is
 122       Dummy_File_Control_Block : Sequential_AFCB;
 123       pragma Warnings (Off, Dummy_File_Control_Block);
 124       --  Yes, we know this is never assigned a value, only the tag
 125       --  is used for dispatching purposes, so that's expected.
 126
 127    begin
 128       FIO.Open (File_Ptr  => AP (File),
 129                 Dummy_FCB => Dummy_File_Control_Block,
 130                 Mode      => Mode,
 131                 Name      => Name,
 132                 Form      => Form,
 133                 Amethod   => 'Q',
 134                 Creat     => False,
 135                 Text      => False);
 136    end Open;
 137
 138    ----------
 139    -- Read --
 140    ----------
 141
 142    --  Not used, since Sequential_IO files are not used as streams
 143
 144    procedure Read
 145      (File : in out Sequential_AFCB;
 146       Item : out Ada.Streams.Stream_Element_Array;
 147       Last : out Ada.Streams.Stream_Element_Offset)
 148    is
 149    begin
 150       raise Program_Error;
 151    end Read;
 152
 153    -----------
 154    -- Write --
 155    -----------
 156
 157    --  Not used, since Sequential_IO files are not used as streams
 158
 159    procedure Write
 160      (File : in out Sequential_AFCB;
 161       Item : Ada.Streams.Stream_Element_Array)
 162    is
 163    begin
 164       raise Program_Error;
 165    end Write;
 166
 167 end System.Sequential_IO;