Ada Programming/Libraries/Interfaces.C


      Ada Lovelace 1838.jpg


      -----------------------------------------------------------------------------
      --                                                                          --
      --                         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;
      
      Last modified on 6 January 2009, at 00:01