File : i-c.ads


-----------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                         I N T E R F A C E S . C                          --
--                                                                          --
--                                 S p e c                                  --
--                                                                          --
--                            $Revision: 1.19 $                             --
--                                                                          --
-- This specification is adapted from the Ada Reference Manual for use with --
-- GNAT.  In accordance with the copyright of that document, you can freely --
-- copy and modify this specification,  provided that if you redistribute a --
-- modified version,  any changes that you have made are clearly indicated. --
--                                                                          --
------------------------------------------------------------------------------

with System.Parameters;

package Interfaces.C is
pragma Pure (C);

   --  Declaration's based on C's <limits.h>

   CHAR_BIT  : constant := 8; 
   SCHAR_MIN : constant := -128; 
   SCHAR_MAX : constant := 127; 
   UCHAR_MAX : constant := 255; 

   --  Signed and Unsigned Integers. Note that in GNAT, we have ensured that
   --  the standard predefined Ada types correspond to the standard C types

   type int   is new Integer; 
   type short is new Short_Integer; 
   type long  is range -(2 ** (System.Parameters.long_bits - 1)) 
     .. +(2 ** (System.Parameters.long_bits - 1)) - 1;

   type signed_char is range SCHAR_MIN .. SCHAR_MAX; 
   for signed_char'Size use CHAR_BIT;

   type unsigned       is mod 2 ** int'Size; 
   type unsigned_short is mod 2 ** short'Size; 
   type unsigned_long  is mod 2 ** long'Size; 

   type unsigned_char is mod (UCHAR_MAX + 1); 
   for unsigned_char'Size use CHAR_BIT;

   subtype plain_char is unsigned_char; -- ??? should be parametrized 

   type ptrdiff_t is 
     range -(2 ** (Standard'Address_Size - 1)) ..
           +(2 ** (Standard'Address_Size - 1) - 1);

   type size_t is mod 2 ** Standard'Address_Size; 

   --  Floating-Point

   type C_float     is new Float; 
   type double      is new Standard.Long_Float; 
   type long_double is new Standard.Long_Long_Float; 

   ----------------------------
   -- Characters and Strings --
   ----------------------------

   type char is new Character; 

   nul : constant char := char'First; 

   function To_C   (Item : Character) return char; 
   function To_Ada (Item : char)      return Character; 

   type char_array is array (size_t range <>) of aliased char; 
   for char_array'Component_Size use CHAR_BIT;

   function Is_Nul_Terminated (Item : in char_array) return Boolean; 

   function To_C 
     (Item       : in String; 
      Append_Nul : in Boolean := True) 
      return       char_array;

   function To_Ada 
     (Item     : in char_array; 
      Trim_Nul : in Boolean := True) 
      return     String;

   procedure To_C 
     (Item       : in String; 
      Target     : out char_array; 
      Count      : out size_t; 
      Append_Nul : in Boolean := True); 

   procedure To_Ada 
     (Item     : in char_array; 
      Target   : out String; 
      Count    : out Natural; 
      Trim_Nul : in Boolean := True); 

   ------------------------------------
   -- Wide Character and Wide String --
   ------------------------------------

   type wchar_t is new Wide_Character; 
   for wchar_t'Size use Standard'Wchar_T_Size;

   wide_nul : constant wchar_t := wchar_t'First; 

   function To_C   (Item : in Wide_Character) return wchar_t; 
   function To_Ada (Item : in wchar_t)        return Wide_Character; 

   type wchar_array is array (size_t range <>) of aliased wchar_t; 

   function Is_Nul_Terminated (Item : in wchar_array) return Boolean; 

   function To_C 
     (Item       : in Wide_String; 
      Append_Nul : in Boolean := True) 
      return       wchar_array;

   function To_Ada 
     (Item     : in wchar_array; 
      Trim_Nul : in Boolean := True) 
      return     Wide_String;

   procedure To_C 
     (Item       : in Wide_String; 
      Target     : out wchar_array; 
      Count      : out size_t; 
      Append_Nul : in Boolean := True); 

   procedure To_Ada 
     (Item     : in wchar_array; 
      Target   : out Wide_String; 
      Count    : out Natural; 
      Trim_Nul : in Boolean := True); 

   Terminator_Error : exception; 

end Interfaces.C;