debug symbols?

How can i add debug symbols so i can see whats going on better.
BTW i'm on devc++4 .
GDB debuger.
Thanks alot

Code:

//recursive factorial function
#include <iostream>
#include <iomanip>
using namespace std;

unsigned long factorial( unsigned long );

int main()
{
   for (int i = 1; i <= 10; i++ )
      cout << setw( 2 ) << i << "! = " << factorial( i ) << endl;

   return 0;
}

// recursive definition of function factorial
unsigned long factorial( unsigned long number )
{
   if ( number <= 1 )   // base case
      return 1;
   else                 // recursive case
      return number * factorial( number -1 );
}

If you select a "debug" build, then you get debug information automatically