Re: Interfacing C and Ada95

[David Marceau <davidmarceau@sympatico.ca>]

Antonio Mart�nez wrote:
> 
> Hello group.
> 
> I'm trying to interface C and Ada95 using gcc and gnat. The question is,
> Why I cannot use put_line in my function sumtwo ?
> 
> I have this 3 sources (these are very small...)
> 
> paquete.ads:
> package Paquete is
>    function sumtwo(X : in Integer) return Integer;
>    pragma Export_Function(Internal=>sumtwo, External=>sumtwo);
> end Paquete;
> 
> paquete.adb:
> with Ada.Text_io; use Ada.Text_Io;
> package body Paquete is
>    function sumtwo(X : in Integer) return Integer is
>    begin
>       -- put_line("Hello");
>       return X + 2;
>    end sumtwo;
> end Paquete;
> 
> progC.c:
> 
> #include <stdio.h>
> int sumtwo();
> int main() {
adainit();

>   int i = 3;
>   printf("%i + 2 = %i\n", i, masdos(3));
adafinal();

>   return 0;
> }
> 
> Ok... now I compile like this:
> 
> gnatmake paquete.adb           -> generates paquete.ali & paquete.o
> gcc progC.v paquete.o -o progC -> generates progC executable
> 
> and it works !!!!   Ok. Now, if I add the 5th line in the file
> paquete.adb, which contains put_line("Hello"), the gcc says ...
> paquete.o(.text+0x10): In function `sumtwo':
> 
> : referencia a `ada__text_io__put_line__2' sin definir
> collect2: ld devolvi� el estado de salida 1
> 
> What is the problem? Do I have to export Ada.Text_IO in any matter?
> 
> Thank you.
> 
> --
> Antonio Mart�nez