gcc/ada/s-sequio.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUNTIME 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) 1992-2002 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,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, 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)
  49       return          FCB.AFCB_Ptr
  50    is
  51       pragma Warnings (Off, Control_Block);
  52
  53    begin
  54       return new Sequential_AFCB;
  55    end AFCB_Allocate;
  56
  57    ----------------
  58    -- AFCB_Close --
  59    ----------------
  60
  61    --  No special processing required for Sequential_IO close
  62
  63    procedure AFCB_Close (File : access Sequential_AFCB) is
  64       pragma Warnings (Off, File);
  65
  66    begin
  67       null;
  68    end AFCB_Close;
  69
  70    ---------------
  71    -- AFCB_Free --
  72    ---------------
  73
  74    procedure AFCB_Free (File : access Sequential_AFCB) is
  75
  76       type FCB_Ptr is access all Sequential_AFCB;
  77
  78       FT : FCB_Ptr := FCB_Ptr (File);
  79
  80       procedure Free is new
  81         Unchecked_Deallocation (Sequential_AFCB, FCB_Ptr);
  82
  83    begin
  84       Free (FT);
  85    end AFCB_Free;
  86
  87    ------------
  88    -- Create --
  89    ------------
  90
  91    procedure Create
  92      (File : in out File_Type;
  93       Mode : in FCB.File_Mode := FCB.Out_File;
  94       Name : in String := "";
  95       Form : in String := "")
  96    is
  97       Dummy_File_Control_Block : Sequential_AFCB;
  98       pragma Warnings (Off, Dummy_File_Control_Block);
  99       --  Yes, we know this is never assigned a value, only the tag
 100       --  is used for dispatching purposes, so that's expected.
 101
 102    begin
 103       FIO.Open (File_Ptr  => AP (File),
 104                 Dummy_FCB => Dummy_File_Control_Block,
 105                 Mode      => Mode,
 106                 Name      => Name,
 107                 Form      => Form,
 108                 Amethod   => 'Q',
 109                 Creat     => True,
 110                 Text      => False);
 111    end Create;
 112
 113    ----------
 114    -- Open --
 115    ----------
 116
 117    procedure Open
 118      (File : in out File_Type;
 119       Mode : in FCB.File_Mode;
 120       Name : in String;
 121       Form : in String := "")
 122    is
 123       Dummy_File_Control_Block : Sequential_AFCB;
 124       pragma Warnings (Off, Dummy_File_Control_Block);
 125       --  Yes, we know this is never assigned a value, only the tag
 126       --  is used for dispatching purposes, so that's expected.
 127
 128    begin
 129       FIO.Open (File_Ptr  => AP (File),
 130                 Dummy_FCB => Dummy_File_Control_Block,
 131                 Mode      => Mode,
 132                 Name      => Name,
 133                 Form      => Form,
 134                 Amethod   => 'Q',
 135                 Creat     => False,
 136                 Text      => False);
 137    end Open;
 138
 139    ----------
 140    -- Read --
 141    ----------
 142
 143    --  Not used, since Sequential_IO files are not used as streams
 144
 145    procedure Read
 146      (File : in out Sequential_AFCB;
 147       Item : out Ada.Streams.Stream_Element_Array;
 148       Last : out Ada.Streams.Stream_Element_Offset)
 149    is
 150    begin
 151       raise Program_Error;
 152    end Read;
 153
 154    -----------
 155    -- Write --
 156    -----------
 157
 158    --  Not used, since Sequential_IO files are not used as streams
 159
 160    procedure Write
 161      (File : in out Sequential_AFCB;
 162       Item : in Ada.Streams.Stream_Element_Array)
 163    is
 164    begin
 165       raise Program_Error;
 166    end Write;
 167
 168 end System.Sequential_IO;