#define _GNU_SOURCE
#include <stdio.h>
#include <libguile.h>

static scm_t_bits handlesmob_tag;
void smobbug_init (void);
SCM mark_handle (SCM x);


SCM handlesmob_init ()
{
  SCM s_handlesmob;
  char *handle;

  handle = malloc (1);
  
  return SCM_NEWSMOB (s_handlesmob, handlesmob_tag, handle);
}

SCM
mark_handlesmob (SCM x)
{
  // No SCMs in the handle type: nothing to do here.
  return (SCM_BOOL_F);
}

size_t
free_handlesmob (SCM handle)
{
  SCM_ASSERT (SCM_SMOB_PREDICATE (handlesmob_tag, handle), handle, SCM_ARG1, "free-handlesmob");

  char *m = SCM_SMOB_DATA (handle);

  if (m != NULL)
      free (m);

  return 0;
}

int
print_handlesmob (SCM x, SCM port, scm_print_state *pstate)
{
  char *frm = (char *) SCM_SMOB_DATA (x);
  char *str;

  scm_puts ("#<handlesmob ", port);

  if (frm == (char *) NULL)
    {
      scm_puts ("(freed)", port);
    }
  else
    {
      if (asprintf (&str, "%p", frm) < 0)
	scm_puts ("???", port);
      else
	scm_puts (str, port);
    }

  scm_puts (">", port);
  
  // non-zero means success 
  return 1;
}

void
smobbug_init ()
{
  handlesmob_tag = scm_make_smob_type ("handlesmob", sizeof (char *));
  scm_set_smob_mark (handlesmob_tag, mark_handlesmob);
  scm_set_smob_free (handlesmob_tag, free_handlesmob);
  scm_set_smob_print (handlesmob_tag, print_handlesmob);
  scm_c_define_gsubr ("%handlesmob-init", 0, 0, 0, handlesmob_init);
}