File : i-c.ads


     -----------------------------------------------------------------------------
     --                                                                          --
     --                         GNAT COMPILER COMPONENTS                         --
     --                                                                          --
   5 --                         I N T E R F A C E S . C                          --
     --                                                                          --
     --                                 S p e c                                  --
     --                                                                          --
     --                            $Revision: 1.19 $                             --
  10 --                                                                          --
     -- 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. --
  15 --                                                                          --
     ------------------------------------------------------------------------------
     
     with System.Parameters;
     
  20 package Interfaces.C is
     pragma Pure (C);
     
        --  Declaration's based on C's <limits.h>
     
  25    CHAR_BIT  : constant := 8;
        SCHAR_MIN : constant := -128;
        SCHAR_MAX : constant := 127;
        UCHAR_MAX : constant := 255;
     
  30    --  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;
  35    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;
  40 
        type unsigned       is mod 2 ** int'Size;
        type unsigned_short is mod 2 ** short'Size;
        type unsigned_long  is mod 2 ** long'Size;
     
  45    type unsigned_char is mod (UCHAR_MAX + 1);
        for unsigned_char'Size use CHAR_BIT;
     
        subtype plain_char is unsigned_char; -- ??? should be parametrized
     
  50    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;
  55 
        --  Floating-Point
     
        type C_float     is new Float;
        type double      is new Standard.Long_Float;
  60    type long_double is new Standard.Long_Long_Float;
     
        ----------------------------
        -- Characters and Strings --
        ----------------------------
  65 
        type char is new Character;
     
        nul : constant char := char'First;
     
  70    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;
  75 
        function Is_Nul_Terminated (Item : in char_array) return Boolean;
     
        function To_C
          (Item       : in String;
  80       Append_Nul : in Boolean := True)
           return       char_array;
     
        function To_Ada
          (Item     : in char_array;
  85       Trim_Nul : in Boolean := True)
           return     String;
     
        procedure To_C
          (Item       : in String;
  90       Target     : out char_array;
           Count      : out size_t;
           Append_Nul : in Boolean := True);
     
        procedure To_Ada
  95      (Item     : in char_array;
           Target   : out String;
           Count    : out Natural;
           Trim_Nul : in Boolean := True);
     
 100    ------------------------------------
        -- Wide Character and Wide String --
        ------------------------------------
     
        type wchar_t is new Wide_Character;
 105    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;
 110    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;
 115 
        function To_C
          (Item       : in Wide_String;
           Append_Nul : in Boolean := True)
           return       wchar_array;
 120 
        function To_Ada
          (Item     : in wchar_array;
           Trim_Nul : in Boolean := True)
           return     Wide_String;
 125 
        procedure To_C
          (Item       : in Wide_String;
           Target     : out wchar_array;
           Count      : out size_t;
 130       Append_Nul : in Boolean := True);
     
        procedure To_Ada
          (Item     : in wchar_array;
           Target   : out Wide_String;
 135       Count    : out Natural;
           Trim_Nul : in Boolean := True);
     
        Terminator_Error : exception;
     
 140 end Interfaces.C;