mingw-w64-crt/crt64/gccmain.c

#include <stdlib.h>

typedef void (*func_ptr) (void);
extern func_ptr __CTOR_LIST__[];
extern func_ptr __DTOR_LIST__[];

void
__do_global_dtors (void)
{
  static func_ptr *p = __DTOR_LIST__ + 1;

  while (*p)
    {
      (*(p)) ();
      p++;
    }
}

void
__do_global_ctors (void)
{
  unsigned long nptrs = (unsigned long) (ptrdiff_t) __CTOR_LIST__[0];
  unsigned long i;

  if (nptrs == (unsigned long) -1)
    {
      for (nptrs = 0; __CTOR_LIST__[nptrs + 1] != 0; nptrs++);
    }

  for (i = nptrs; i >= 1; i--)
    {
      __CTOR_LIST__[i] ();
    }

  atexit (__do_global_dtors);
}

static int initialized = 0;

void
__main (void)
{
  if (!initialized)
    {
      initialized = 1;
      __do_global_ctors ();
    }
}