Re: Help with ADA and C function pointers.

[fd@piau ()]

Wendell P Beckwith (wbeckwit@rsa.hisd.harris.com) wrote:
: I have an ada main procedure which needs to pass the address of an ada
: function to a C funciton.  Using gnat 3.05 the following compiles and
: generates an executable, but it cores when you run it.  I knew it would
: because no where am I assigning a function to be passed.  That is what
: I'd like to know how to do.  Please respond to my work email, since I'm
: not in this group alot.  Thanks!!

: Wendell

: -- my test main
: with Text_IO, Interfaces.C; 
: use Text_IO;

: Procedure Gmain is

: 	Function func(d : in Integer) return Integer is
: 	Begin
: 		return (2 * d);
: 	End;
: 	type func_type is access Function(d : in Integer) return Integer;
: 	funcptr : func_type;
Here funcptr value is NULL
: 	
: 	Procedure Stuff(f : in func_type);
: 	pragma Import(C, Stuff, "stuff");
: 	
: Begin
: 	Stuff(funcptr);
there is a problem, funcptr is still equal to NULL
I will try Stuff(func'adress) and you don't need funcptr.
Hope it will help.
: End;

: -- my test C function using the ada callback
: #include <stdio.h>

: void stuff(int (*function)(int))
: {
: 	printf("Value = %d\n", (*function)(10));
: }

 franck.duluc@avions.aerospatiale.fr
		
Regards.