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
34with System.File_IO;
35with Unchecked_Deallocation;
36
37package 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
168end System.Sequential_IO;
169