1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT RUN-TIME COMPONENTS                         --
4--                                                                          --
5--             S Y S T E M . S T R E A M _ A T T R I B U T E S              --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 1992-2020, 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 3,  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.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32--  This package contains the implementations of the stream attributes for
33--  elementary types. These are the subprograms that are directly accessed
34--  by occurrences of the stream attributes where the type is elementary.
35
36--  We only provide the subprograms for the standard base types. For user
37--  defined types, the subprogram for the corresponding root type is called
38--  with an appropriate conversion.
39
40with System;
41with System.Unsigned_Types;
42with Ada.Streams;
43
44package System.Stream_Attributes is
45   pragma Preelaborate;
46
47   pragma Suppress (Accessibility_Check, Stream_Attributes);
48   --  No need to check accessibility on arguments of subprograms
49
50   package UST renames System.Unsigned_Types;
51
52   subtype RST is Ada.Streams.Root_Stream_Type'Class;
53
54   subtype SEC is Ada.Streams.Stream_Element_Count;
55
56   type Integer_24 is range -2 ** 23 .. 2 ** 23 - 1;
57   for Integer_24'Size use 24;
58
59   type Unsigned_24 is mod 2 ** 24;
60   for Unsigned_24'Size use 24;
61
62   --  Enumeration types are usually transferred using the routine for the
63   --  corresponding integer. The exception is that special routines are
64   --  provided for Boolean and the character types, in case the protocol
65   --  in use provides specially for these types.
66
67   --  Access types use either a thin pointer (single address) or fat pointer
68   --  (double address) form. The following types are used to hold access
69   --  values using unchecked conversions.
70
71   type Thin_Pointer is record
72      P1 : System.Address;
73   end record;
74
75   type Fat_Pointer is record
76      P1 : System.Address;
77      P2 : System.Address;
78   end record;
79
80   ------------------------------------
81   -- Treatment of enumeration types --
82   ------------------------------------
83
84   --  In this interface, there are no specific routines for general input
85   --  or output of enumeration types. Generally, enumeration types whose
86   --  representation is unsigned (no negative representation values) are
87   --  treated as unsigned integers, and enumeration types that do have
88   --  negative representation values are treated as signed integers.
89
90   --  An exception is that there are specialized routines for Boolean,
91   --  Character, and Wide_Character types, but these specialized routines
92   --  are used only if the type in question has a standard representation.
93   --  For the case of a non-standard representation (one where the size of
94   --  the first subtype is specified, or where an enumeration representation
95   --  clause is given), these three types are treated like any other cases
96   --  of enumeration types, as described above.
97
98   ---------------------
99   -- Input Functions --
100   ---------------------
101
102   --  Functions for S'Input attribute. These functions are also used for
103   --  S'Read, with the obvious transformation, since the input operation
104   --  is the same for all elementary types (no bounds or discriminants
105   --  are involved).
106
107   function I_AD   (Stream : not null access RST) return Fat_Pointer;
108   function I_AS   (Stream : not null access RST) return Thin_Pointer;
109   function I_B    (Stream : not null access RST) return Boolean;
110   function I_C    (Stream : not null access RST) return Character;
111   function I_F    (Stream : not null access RST) return Float;
112   function I_I    (Stream : not null access RST) return Integer;
113   function I_I24  (Stream : not null access RST) return Integer_24;
114   function I_LF   (Stream : not null access RST) return Long_Float;
115   function I_LI   (Stream : not null access RST) return Long_Integer;
116   function I_LLF  (Stream : not null access RST) return Long_Long_Float;
117   function I_LLI  (Stream : not null access RST) return Long_Long_Integer;
118   function I_LLLI (Stream : not null access RST) return
119                                                    Long_Long_Long_Integer;
120   function I_LLLU (Stream : not null access RST) return
121                                                   UST.Long_Long_Long_Unsigned;
122   function I_LLU  (Stream : not null access RST) return
123                                                    UST.Long_Long_Unsigned;
124   function I_LU   (Stream : not null access RST) return UST.Long_Unsigned;
125   function I_SF   (Stream : not null access RST) return Short_Float;
126   function I_SI   (Stream : not null access RST) return Short_Integer;
127   function I_SSI  (Stream : not null access RST) return Short_Short_Integer;
128   function I_SSU  (Stream : not null access RST) return
129                                                    UST.Short_Short_Unsigned;
130   function I_SU   (Stream : not null access RST) return UST.Short_Unsigned;
131   function I_U    (Stream : not null access RST) return UST.Unsigned;
132   function I_U24  (Stream : not null access RST) return Unsigned_24;
133   function I_WC   (Stream : not null access RST) return Wide_Character;
134   function I_WWC  (Stream : not null access RST) return Wide_Wide_Character;
135
136   -----------------------
137   -- Output Procedures --
138   -----------------------
139
140   --  Procedures for S'Write attribute. These procedures are also used for
141   --  'Output, since for elementary types there is no difference between
142   --  'Write and 'Output because there are no discriminants or bounds to
143   --  be written.
144
145   procedure W_AD   (Stream : not null access RST; Item : Fat_Pointer);
146   procedure W_AS   (Stream : not null access RST; Item : Thin_Pointer);
147   procedure W_B    (Stream : not null access RST; Item : Boolean);
148   procedure W_C    (Stream : not null access RST; Item : Character);
149   procedure W_F    (Stream : not null access RST; Item : Float);
150   procedure W_I    (Stream : not null access RST; Item : Integer);
151   procedure W_I24  (Stream : not null access RST; Item : Integer_24);
152   procedure W_LF   (Stream : not null access RST; Item : Long_Float);
153   procedure W_LI   (Stream : not null access RST; Item : Long_Integer);
154   procedure W_LLF  (Stream : not null access RST; Item : Long_Long_Float);
155   procedure W_LLI  (Stream : not null access RST; Item : Long_Long_Integer);
156   procedure W_LLLI (Stream : not null access RST; Item :
157                                                     Long_Long_Long_Integer);
158   procedure W_LLLU (Stream : not null access RST; Item :
159                                                  UST.Long_Long_Long_Unsigned);
160   procedure W_LLU  (Stream : not null access RST; Item :
161                                                     UST.Long_Long_Unsigned);
162   procedure W_LU   (Stream : not null access RST; Item : UST.Long_Unsigned);
163   procedure W_SF   (Stream : not null access RST; Item : Short_Float);
164   procedure W_SI   (Stream : not null access RST; Item : Short_Integer);
165   procedure W_SSI  (Stream : not null access RST; Item : Short_Short_Integer);
166   procedure W_SSU  (Stream : not null access RST; Item :
167                                                     UST.Short_Short_Unsigned);
168   procedure W_SU   (Stream : not null access RST; Item : UST.Short_Unsigned);
169   procedure W_U    (Stream : not null access RST; Item : UST.Unsigned);
170   procedure W_U24  (Stream : not null access RST; Item : Unsigned_24);
171   procedure W_WC   (Stream : not null access RST; Item : Wide_Character);
172   procedure W_WWC  (Stream : not null access RST; Item : Wide_Wide_Character);
173
174   function Block_IO_OK return Boolean;
175   --  Indicate whether the current setting supports block IO. See
176   --  System.Strings.Stream_Ops (s-ststop) for details on block IO.
177
178private
179   pragma Inline (I_AD);
180   pragma Inline (I_AS);
181   pragma Inline (I_B);
182   pragma Inline (I_C);
183   pragma Inline (I_F);
184   pragma Inline (I_I);
185   pragma Inline (I_LF);
186   pragma Inline (I_LI);
187   pragma Inline (I_LLF);
188   pragma Inline (I_LLI);
189   pragma Inline (I_LLLI);
190   pragma Inline (I_LLLU);
191   pragma Inline (I_LLU);
192   pragma Inline (I_LU);
193   pragma Inline (I_SF);
194   pragma Inline (I_SI);
195   pragma Inline (I_SSI);
196   pragma Inline (I_SSU);
197   pragma Inline (I_SU);
198   pragma Inline (I_U);
199   pragma Inline (I_WC);
200   pragma Inline (I_WWC);
201
202   pragma Inline (W_AD);
203   pragma Inline (W_AS);
204   pragma Inline (W_B);
205   pragma Inline (W_C);
206   pragma Inline (W_F);
207   pragma Inline (W_I);
208   pragma Inline (W_LF);
209   pragma Inline (W_LI);
210   pragma Inline (W_LLF);
211   pragma Inline (W_LLI);
212   pragma Inline (W_LLLI);
213   pragma Inline (W_LLLU);
214   pragma Inline (W_LLU);
215   pragma Inline (W_LU);
216   pragma Inline (W_SF);
217   pragma Inline (W_SI);
218   pragma Inline (W_SSI);
219   pragma Inline (W_SSU);
220   pragma Inline (W_SU);
221   pragma Inline (W_U);
222   pragma Inline (W_WC);
223   pragma Inline (W_WWC);
224
225   pragma Inline (Block_IO_OK);
226
227end System.Stream_Attributes;
228