static Labeldesc *findlabel (LexState *ls, TString *name) {
  int i;
  Dyndata *dyd = ls->dyd;
  /* check labels in current function for a match */
  for (i = ls->fs->firstlabel; i < dyd->label.n; i++) {
    Labeldesc *lb = &dyd->label.arr[i];
    if (eqstr(lb->name, name))  /* correct label? */
      return lb;
  }
  return NULL;  /* label not found */
}