File : a-direio.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME COMPONENTS --
4 -- --
5 -- A D A . D I R E C T _ I O --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
10 -- --
11 -- This specification is derived from the Ada Reference Manual for use with --
12 -- GNAT. The copyright notice above, and the license provisions that follow --
13 -- apply solely to the contents of the part following the private keyword. --
14 -- --
15 -- GNAT is free software; you can redistribute it and/or modify it under --
16 -- terms of the GNU General Public License as published by the Free Soft- --
17 -- ware Foundation; either version 3, or (at your option) any later ver- --
18 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
19 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
20 -- or FITNESS FOR A PARTICULAR PURPOSE. --
21 -- --
22 -- --
23 -- --
24 -- --
25 -- --
26 -- You should have received a copy of the GNU General Public License and --
27 -- a copy of the GCC Runtime Library Exception along with this program; --
28 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
29 -- <http://www.gnu.org/licenses/>. --
30 -- --
31 -- GNAT was originally developed by the GNAT team at New York University. --
32 -- Extensive contributions were provided by Ada Core Technologies Inc. --
33 -- --
34 ------------------------------------------------------------------------------
35
36 with Ada.IO_Exceptions;
37 with System.Direct_IO;
38 with Interfaces.C_Streams;
39
40 generic
41 type Element_Type is private;
42
43 package Ada.Direct_IO is
44
45 pragma Compile_Time_Warning
46 (Element_Type'Has_Access_Values,
47 "Element_Type for Direct_IO instance has access values");
48
49 pragma Compile_Time_Warning
50 (Element_Type'Has_Tagged_Values,
51 "Element_Type for Direct_IO instance has tagged values");
52
53 type File_Type is limited private;
54
55 type File_Mode is (In_File, Inout_File, Out_File);
56
57 -- The following representation clause allows the use of unchecked
58 -- conversion for rapid translation between the File_Mode type
59 -- used in this package and System.File_IO.
60
61 for File_Mode use
62 (In_File => 0, -- System.File_IO.File_Mode'Pos (In_File)
63 Inout_File => 1, -- System.File_IO.File_Mode'Pos (Inout_File);
64 Out_File => 2); -- System.File_IO.File_Mode'Pos (Out_File)
65
66 type Count is range 0 .. System.Direct_IO.Count'Last;
67
68 subtype Positive_Count is Count range 1 .. Count'Last;
69
70 ---------------------
71 -- File Management --
72 ---------------------
73
74 procedure Create
75 (File : in out File_Type;
76 Mode : File_Mode := Inout_File;
77 Name : String := "";
78 Form : String := "");
79
80 procedure Open
81 (File : in out File_Type;
82 Mode : File_Mode;
83 Name : String;
84 Form : String := "");
85
86 procedure Close (File : in out File_Type);
87 procedure Delete (File : in out File_Type);
88 procedure Reset (File : in out File_Type; Mode : File_Mode);
89 procedure Reset (File : in out File_Type);
90
91 function Mode (File : File_Type) return File_Mode;
92 function Name (File : File_Type) return String;
93 function Form (File : File_Type) return String;
94
95 function Is_Open (File : File_Type) return Boolean;
96
97 ---------------------------------
98 -- Input and Output Operations --
99 ---------------------------------
100
101 procedure Read
102 (File : File_Type;
103 Item : out Element_Type;
104 From : Positive_Count);
105
106 procedure Read
107 (File : File_Type;
108 Item : out Element_Type);
109
110 procedure Write
111 (File : File_Type;
112 Item : Element_Type;
113 To : Positive_Count);
114
115 procedure Write
116 (File : File_Type;
117 Item : Element_Type);
118
119 procedure Set_Index (File : File_Type; To : Positive_Count);
120
121 function Index (File : File_Type) return Positive_Count;
122 function Size (File : File_Type) return Count;
123
124 function End_Of_File (File : File_Type) return Boolean;
125
126 ----------------
127 -- Exceptions --
128 ----------------
129
130 Status_Error : exception renames IO_Exceptions.Status_Error;
131 Mode_Error : exception renames IO_Exceptions.Mode_Error;
132 Name_Error : exception renames IO_Exceptions.Name_Error;
133 Use_Error : exception renames IO_Exceptions.Use_Error;
134 Device_Error : exception renames IO_Exceptions.Device_Error;
135 End_Error : exception renames IO_Exceptions.End_Error;
136 Data_Error : exception renames IO_Exceptions.Data_Error;
137
138 private
139
140 -- The following procedures have a File_Type formal of mode IN OUT because
141 -- they may close the original file. The Close operation may raise an
142 -- exception, but in that case we want any assignment to the formal to
143 -- be effective anyway, so it must be passed by reference (or the caller
144 -- will be left with a dangling pointer).
145
146 pragma Export_Procedure
147 (Internal => Close,
148 External => "",
149 Mechanism => Reference);
150 pragma Export_Procedure
151 (Internal => Delete,
152 External => "",
153 Mechanism => Reference);
154 pragma Export_Procedure
155 (Internal => Reset,
156 External => "",
157 Parameter_Types => (File_Type),
158 Mechanism => Reference);
159 pragma Export_Procedure
160 (Internal => Reset,
161 External => "",
162 Parameter_Types => (File_Type, File_Mode),
163 Mechanism => (File => Reference));
164
165 type File_Type is new System.Direct_IO.File_Type;
166
167 Bytes : constant Interfaces.C_Streams.size_t :=
168 Interfaces.C_Streams.size_t'Max
169 (1, Element_Type'Max_Size_In_Storage_Elements);
170 -- Size of an element in storage units. The Max operation here is to ensure
171 -- that we allocate a single byte for zero-sized elements. It's a bit weird
172 -- to instantiate Direct_IO with zero sized elements, but it is legal and
173 -- this adjustment ensures that we don't get anomalous behavior.
174
175 pragma Inline (Close);
176 pragma Inline (Create);
177 pragma Inline (Delete);
178 pragma Inline (End_Of_File);
179 pragma Inline (Form);
180 pragma Inline (Index);
181 pragma Inline (Is_Open);
182 pragma Inline (Mode);
183 pragma Inline (Name);
184 pragma Inline (Open);
185 pragma Inline (Read);
186 pragma Inline (Reset);
187 pragma Inline (Set_Index);
188 pragma Inline (Size);
189 pragma Inline (Write);
190
191 end Ada.Direct_IO;