.mm Преобразование вызывает неопределенные символы для архитектуры ошибок I386

Я недавно импортировал файл C ++ в мой проект OBJ, который я хочу использовать. В классе я хочу использовать его в I, я изменяю имя файла из myclass.m на myclass.mm.

Делать это дает мне 20 или около того ошибок. Что именно выполняет эти ошибки и как я могу изменить MyClass на объективный класс C ++, чтобы облегчить новое класс C ++, который я хочу использовать, не получая эти ошибки?

Undefined symbols for architecture i386:
  "setAudioInputIsStereo(audiosourceobj*, bool)", referenced from:
      -[Engine extractMp3Audio:withChannelId:withPadId:] in Engine.o
  "setAudioInputFrameCount(audiosourceobj*, int)", referenced from:
      -[Engine extractMp3Audio:withChannelId:withPadId:] in Engine.o
  "setAudioInputSendValue(audiosourceobj*, int)", referenced from:
      -[Engine extractMp3Audio:withChannelId:withPadId:] in Engine.o
  "getPointerToAudioLeftBuffer(audiosourceobj*)", referenced from:
      -[Engine extractMp3Audio:withChannelId:withPadId:] in Engine.o
  "getPointerToAudioRightBuffer(audiosourceobj*)", referenced from:
      -[Engine extractMp3Audio:withChannelId:withPadId:] in Engine.o
  "freeAudioBuffers(audiosourceobj*)", referenced from:
      -[Engine extractMp3Audio:withChannelId:withPadId:] in Engine.o
      -[Engine clearAudioInput:pid:] in Engine.o
      -[Engine reset] in Engine.o
  "setAudioInputReadPoint(audiosourceobj*, int)", referenced from:
      -[Engine extractMp3Audio:withChannelId:withPadId:] in Engine.o
  "setAudioInputHasAudio(audiosourceobj*, bool)", referenced from:
      -[Engine extractMp3Audio:withChannelId:withPadId:] in Engine.o
      -[Engine reset] in Engine.o
      -[Engine setAudioPath:channel:pad:] in Engine.o
  "setAudioInputState(audiosourceobj*, int)", referenced from:
      -[Engine extractMp3Audio:withChannelId:withPadId:] in Engine.o
      -[Engine clearAudioInput:pid:] in Engine.o
      -[Engine reset] in Engine.o
      -[Engine setAudioPath:channel:pad:] in Engine.o
  "initAudioInputHasAudio(audiosourceobj*, signed char)", referenced from:
      -[Engine clearAudioInput:pid:] in Engine.o
      -[Engine reset] in Engine.o
  "initAudioInputReadPoint(audiosourceobj*, int)", referenced from:
      -[Engine clearAudioInput:pid:] in Engine.o
      -[Engine reset] in Engine.o
  "initAudioInputFrameCount(audiosourceobj*, int)", referenced from:
      -[Engine clearAudioInput:pid:] in Engine.o
      -[Engine reset] in Engine.o
  "initAudioInputSampleToAction(audiosourceobj*, int)", referenced from:
      -[Engine clearAudioInput:pid:] in Engine.o
      -[Engine reset] in Engine.o
  "newChannelOBJ()", referenced from:
      setUpChannels(int, int)in Engine.o
  "setVolume(channelobj*, float)", referenced from:
      setUpChannels(int, int)in Engine.o
  "setMute(channelobj*, int)", referenced from:
      setUpChannels(int, int)in Engine.o
  "setNumberOfInputs(channelobj*, int)", referenced from:
      setUpChannels(int, int)in Engine.o
  "setChannelID(channelobj*, int)", referenced from:
      setUpChannels(int, int)in Engine.o
  "createInputs(channelobj*, int)", referenced from:
      setUpChannels(int, int)in Engine.o
  "setBufferSize(channelobj*, float)", referenced from:
      setUpChannels(int, int)in Engine.o
  "createChannelEQS(channelobj*)", referenced from:
      setUpChannels(int, int)in Engine.o
  "actionupdatecomplete(audiosourceobj*, objc_object*)", referenced from:
      channelMixerCallback(void*, unsigned long*, AudioTimeStamp const*, unsigned long, unsigned long, AudioBufferList*)in Engine.o