Missing emit keyword on signal call

#define S1(signal) emit signal();         
    S1(this->signalAddSongModelLoaded)              // problem
    this->signalAddSongModelLoaded();               // expected problem
    emit this->signalAddSongModelLoaded();          // expected no problem
#define S2 emit this->signalAddSongModelLoaded();         
    S2                                              // problem