savestack
func = savestack(L, o);
status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
ci->extra = savestack(L, c.func);
ci->extra = savestack(L, temp);
ptrdiff_t top = savestack(L, L->top);
ptrdiff_t ci_top = savestack(L, ci->top);
ptrdiff_t funcr = savestack(L, func);
ptrdiff_t funcr = savestack(L, func);
ptrdiff_t fr = savestack(L, firstResult); /* hook may change stack */
ci->extra = savestack(L, ci->func); /* save current 'func' */
status = luaD_pcall(L, f_parser, &p, savestack(L, L->top), L->errfunc);
status = luaD_pcall(L, dothecall, NULL, savestack(L, L->top - 2), 0);
ptrdiff_t result = savestack(L, p3);