Package: Interfaces.C

Dependencies

with System.Parameters;

Description

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.

Header

package Interfaces.C is

pragma Pure (C);

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

Known child units

`Interfaces.C.Extensions`	(package)
`Interfaces.C.Pointers`	(generic package)
`Interfaces.C.Strings`	(package)

Exceptions

Terminator_Error

Type Summary

`C_float` derived from `Float`
`char` derived from `Character`
`char_array`
`double` derived from `Long_Float`
`int` derived from `Integer`
`long`
`long_double` derived from `Long_Long_Float`
`ptrdiff_t`
`short` derived from `Short_Integer`
`signed_char`
`size_t`
`unsigned`
`unsigned_char`
`unsigned_long`
`unsigned_short`
`wchar_array`
`wchar_t` derived from `Wide_Character`

Constants and Named Numbers

CHAR_BIT : constant := 8;

nul : constant char := char'First;

SCHAR_MAX : constant := 127;

SCHAR_MIN : constant := -128;

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

wide_nul : constant wchar_t := wchar_t'First;

Other Items:

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;

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;

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);

end Interfaces.C;