gcc/ada/s-stratt.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUNTIME 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) 1992-2003 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 --  This package contains the implementations of the stream attributes for
  35 --  elementary types. These are the subprograms that are directly accessed
  36 --  by occurrences of the stream attributes where the type is elementary.
  37
  38 --  We only provide the subprograms for the standard base types. For user
  39 --  defined types, the subprogram for the corresponding root type is called
  40 --  with an appropriate conversion.
  41
  42 with System;
  43 with System.Unsigned_Types;
  44 with Ada.Streams;
  45
  46 package System.Stream_Attributes is
  47 pragma Preelaborate (Stream_Attributes);
  48
  49    pragma Suppress (Accessibility_Check, Stream_Attributes);
  50    --  No need to check accessibility on arguments of subprograms
  51
  52    package UST renames System.Unsigned_Types;
  53
  54    subtype RST is Ada.Streams.Root_Stream_Type'Class;
  55
  56    subtype SEC is Ada.Streams.Stream_Element_Count;
  57
  58    --  Enumeration types are usually transferred using the routine for the
  59    --  corresponding integer. The exception is that special routines are
  60    --  provided for Boolean and the character types, in case the protocol
  61    --  in use provides specially for these types.
  62
  63    --  Access types use either a thin pointer (single address) or fat pointer
  64    --  (double address) form. The following types are used to hold access
  65    --  values using unchecked conversions.
  66
  67    type Thin_Pointer is record
  68       P1 : System.Address;
  69    end record;
  70
  71    type Fat_Pointer is record
  72       P1 : System.Address;
  73       P2 : System.Address;
  74    end record;
  75
  76    ------------------------------------
  77    -- Treatment of enumeration types --
  78    ------------------------------------
  79
  80    --  In this interface, there are no specific routines for general input
  81    --  or output of enumeration types. Generally, enumeration types whose
  82    --  representation is unsigned (no negative representation values) are
  83    --  treated as unsigned integers, and enumeration types that do have
  84    --  negative representation values are treated as signed integers.
  85
  86    --  An exception is that there are specialized routines for Boolean,
  87    --  Character, and Wide_Character types, but these specialized routines
  88    --  are used only if the type in question has a standard representation.
  89    --  For the case of a non-standard representation (one where the size of
  90    --  the first subtype is specified, or where an enumeration representation
  91    --  clause is given, these three types are treated like any other cases
  92    --  of enumeration types, as described above.
  93    --  for
  94
  95    ---------------------
  96    -- Input Functions --
  97    ---------------------
  98
  99    --  Functions for S'Input attribute. These functions are also used for
 100    --  S'Read, with the obvious transformation, since the input operation
 101    --  is the same for all elementary types (no bounds or discriminants
 102    --  are involved).
 103
 104    function I_AD  (Stream : access RST) return Fat_Pointer;
 105    function I_AS  (Stream : access RST) return Thin_Pointer;
 106    function I_B   (Stream : access RST) return Boolean;
 107    function I_C   (Stream : access RST) return Character;
 108    function I_F   (Stream : access RST) return Float;
 109    function I_I   (Stream : access RST) return Integer;
 110    function I_LF  (Stream : access RST) return Long_Float;
 111    function I_LI  (Stream : access RST) return Long_Integer;
 112    function I_LLF (Stream : access RST) return Long_Long_Float;
 113    function I_LLI (Stream : access RST) return Long_Long_Integer;
 114    function I_LLU (Stream : access RST) return UST.Long_Long_Unsigned;
 115    function I_LU  (Stream : access RST) return UST.Long_Unsigned;
 116    function I_SF  (Stream : access RST) return Short_Float;
 117    function I_SI  (Stream : access RST) return Short_Integer;
 118    function I_SSI (Stream : access RST) return Short_Short_Integer;
 119    function I_SSU (Stream : access RST) return UST.Short_Short_Unsigned;
 120    function I_SU  (Stream : access RST) return UST.Short_Unsigned;
 121    function I_U   (Stream : access RST) return UST.Unsigned;
 122    function I_WC  (Stream : access RST) return Wide_Character;
 123
 124    -----------------------
 125    -- Output Procedures --
 126    -----------------------
 127
 128    --  Procedures for S'Write attribute. These procedures are also used
 129    --  for 'Output, since for elementary types there is no difference
 130    --  between 'Write and 'Output because there are no discriminants
 131    --  or bounds to be written.
 132
 133    procedure W_AD  (Stream : access RST; Item : in Fat_Pointer);
 134    procedure W_AS  (Stream : access RST; Item : in Thin_Pointer);
 135    procedure W_B   (Stream : access RST; Item : in Boolean);
 136    procedure W_C   (Stream : access RST; Item : in Character);
 137    procedure W_F   (Stream : access RST; Item : in Float);
 138    procedure W_I   (Stream : access RST; Item : in Integer);
 139    procedure W_LF  (Stream : access RST; Item : in Long_Float);
 140    procedure W_LI  (Stream : access RST; Item : in Long_Integer);
 141    procedure W_LLF (Stream : access RST; Item : in Long_Long_Float);
 142    procedure W_LLI (Stream : access RST; Item : in Long_Long_Integer);
 143    procedure W_LLU (Stream : access RST; Item : in UST.Long_Long_Unsigned);
 144    procedure W_LU  (Stream : access RST; Item : in UST.Long_Unsigned);
 145    procedure W_SF  (Stream : access RST; Item : in Short_Float);
 146    procedure W_SI  (Stream : access RST; Item : in Short_Integer);
 147    procedure W_SSI (Stream : access RST; Item : in Short_Short_Integer);
 148    procedure W_SSU (Stream : access RST; Item : in UST.Short_Short_Unsigned);
 149    procedure W_SU  (Stream : access RST; Item : in UST.Short_Unsigned);
 150    procedure W_U   (Stream : access RST; Item : in UST.Unsigned);
 151    procedure W_WC  (Stream : access RST; Item : in Wide_Character);
 152
 153    ----------------------------
 154    -- Composite Input/Output --
 155    ----------------------------
 156
 157    --  The following Boolean constant is defined and set to True only if the
 158    --  stream representation of a series of elementary items of the same
 159    --  type (one of the types handled by the above procedures) has the same
 160    --  representation as an array of such items in memory. This allows such
 161    --  a series of items to be read or written as a block, instead of
 162    --  element by element.
 163
 164    --  If the stream representation does not have this property for all the
 165    --  above types, then this constant can be omitted or set to False,
 166    --  and the front end will generate element-by-element operations.
 167
 168    --  This interface assumes that a Stream_Element has the same size as
 169    --  a Storage_Unit. If that is not the case, then this flag should
 170    --  also be omitted (or set to False).
 171
 172    Block_Stream_Ops_OK : constant Boolean := True;
 173    --  Set to False if block stream operations not permitted
 174
 175 private
 176    pragma Inline (I_AD);
 177    pragma Inline (I_AS);
 178    pragma Inline (I_B);
 179    pragma Inline (I_C);
 180    pragma Inline (I_F);
 181    pragma Inline (I_I);
 182    pragma Inline (I_LF);
 183    pragma Inline (I_LI);
 184    pragma Inline (I_LLF);
 185    pragma Inline (I_LLI);
 186    pragma Inline (I_LLU);
 187    pragma Inline (I_LU);
 188    pragma Inline (I_SF);
 189    pragma Inline (I_SI);
 190    pragma Inline (I_SSI);
 191    pragma Inline (I_SSU);
 192    pragma Inline (I_SU);
 193    pragma Inline (I_U);
 194    pragma Inline (I_WC);
 195
 196    pragma Inline (W_AD);
 197    pragma Inline (W_AS);
 198    pragma Inline (W_B);
 199    pragma Inline (W_C);
 200    pragma Inline (W_F);
 201    pragma Inline (W_I);
 202    pragma Inline (W_LF);
 203    pragma Inline (W_LI);
 204    pragma Inline (W_LLF);
 205    pragma Inline (W_LLI);
 206    pragma Inline (W_LLU);
 207    pragma Inline (W_LU);
 208    pragma Inline (W_SF);
 209    pragma Inline (W_SI);
 210    pragma Inline (W_SSI);
 211    pragma Inline (W_SSU);
 212    pragma Inline (W_SU);
 213    pragma Inline (W_U);
 214    pragma Inline (W_WC);
 215
 216 end System.Stream_Attributes;