/* Portable constructors in C
 *
 *  - Supports: GCC, MSVC
 *
 * Author: David Zeuthen <zeuthen@gmail.com>
 */


#include <stdio.h>

#if defined (__GNUC__)

/* on the GNU C compiler, this is easy as pie */

#define XXX_CONSTRUCTOR(func)                               \
  static void __attribute ((constructor)) func (void);

#elif defined (_MSC_VER)

/* From http://www.codeguru.com/cpp/misc/misc/threadsprocesses/article.php/c6945__2/
 *      http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/7737e56f-c813-4c96-a632-5db7a26ef2fc/
 *
 * According to codesearch, the Boost threading library depends on
 * this.. so it's safe for us to depend on it too.
 */
#define XXX_CONSTRUCTOR(func)                                                \
  static void func (void);                                                   \
  static int                                                                 \
  constructor_##func (void)                                                  \
  {                                                                          \
    func ();                                                                 \
    return 0;                                                                \
  }                                                                          \
  __pragma(section(".CRT$XIU", long, read))                                  \
  __pragma(data_seg(".CRT$XIU"))                                             \
  volatile static int(*constructor_ptr_##func) (void) = constructor_##func;  \
  __pragma(data_seg())

#else

#error "Please add constructor/destructor support for your compiler"

#endif


XXX_CONSTRUCTOR (foo_constructor);
XXX_CONSTRUCTOR (bar_constructor);

static void
foo_constructor (void)
{
    printf ("Hello World from foo_constructor()\n");
}

static void
bar_constructor (void)
{
    printf ("Hello World from bar_constructor()\n");
}

int
main (int argc, char *argv[])
{
	int class = 42; /* this demonstrates this is C, not C++ */

	printf ("Hello World from main()\n");

	return 0;
}