Codechange: Use null pointer literal instead of the NULL macro

src/sound/allegro_s.cpp

@@ -22,18 +22,18 @@
 
 static FSoundDriver_Allegro iFSoundDriver_Allegro;
 /** The stream we are writing too */
-static AUDIOSTREAM *_stream = NULL;
+static AUDIOSTREAM *_stream = nullptr;
 /** The number of samples in the buffer */
 static int _buffer_size;
 
 void SoundDriver_Allegro::MainLoop()
 {
 	/* We haven't opened a stream yet */
-	if (_stream == NULL) return;
+	if (_stream == nullptr) return;
 
 	void *data = get_audio_stream_buffer(_stream);
 	/* We don't have to fill the stream yet */
-	if (data == NULL) return;
+	if (data == nullptr) return;
 
 	/* Mix the samples */
 	MxMixSamples(data, _buffer_size);
@@ -54,14 +54,14 @@ extern int _allegro_instance_count;
 
 const char *SoundDriver_Allegro::Start(const char * const *parm)
 {
-	if (_allegro_instance_count == 0 && install_allegro(SYSTEM_AUTODETECT, &errno, NULL)) {
+	if (_allegro_instance_count == 0 && install_allegro(SYSTEM_AUTODETECT, &errno, nullptr)) {
 		DEBUG(driver, 0, "allegro: install_allegro failed '%s'", allegro_error);
 		return "Failed to set up Allegro";
 	}
 	_allegro_instance_count++;
 
 	/* Initialise the sound */
-	if (install_sound(DIGI_AUTODETECT, MIDI_AUTODETECT, NULL) != 0) {
+	if (install_sound(DIGI_AUTODETECT, MIDI_AUTODETECT, nullptr) != 0) {
 		DEBUG(driver, 0, "allegro: install_sound failed '%s'", allegro_error);
 		return "Failed to set up Allegro sound";
 	}
@@ -76,14 +76,14 @@ const char *SoundDriver_Allegro::Start(const char * const *parm)
 	_buffer_size = GetDriverParamInt(parm, "samples", 1024) * hz / 11025;
 	_stream = play_audio_stream(_buffer_size, 16, true, hz, 255, 128);
 	MxInitialize(hz);
-	return NULL;
+	return nullptr;
 }
 
 void SoundDriver_Allegro::Stop()
 {
-	if (_stream != NULL) {
+	if (_stream != nullptr) {
 		stop_audio_stream(_stream);
-		_stream = NULL;
+		_stream = nullptr;
 	}
 	remove_sound();
 

src/sound/cocoa_s.cpp

@@ -80,9 +80,9 @@ const char *SoundDriver_Cocoa::Start(const char * const *parm)
 		desc.componentFlags = 0;
 		desc.componentFlagsMask = 0;
 
-		AudioComponent comp = AudioComponentFindNext (NULL, &desc);
-		if (comp == NULL) {
-			return "cocoa_s: Failed to start CoreAudio: AudioComponentFindNext returned NULL";
+		AudioComponent comp = AudioComponentFindNext (nullptr, &desc);
+		if (comp == nullptr) {
+			return "cocoa_s: Failed to start CoreAudio: AudioComponentFindNext returned nullptr";
 		}
 
 		/* Open & initialize the default output audio unit */
@@ -101,9 +101,9 @@ const char *SoundDriver_Cocoa::Start(const char * const *parm)
 		desc.componentFlags = 0;
 		desc.componentFlagsMask = 0;
 
-		Component comp = FindNextComponent (NULL, &desc);
-		if (comp == NULL) {
-			return "cocoa_s: Failed to start CoreAudio: FindNextComponent returned NULL";
+		Component comp = FindNextComponent (nullptr, &desc);
+		if (comp == nullptr) {
+			return "cocoa_s: Failed to start CoreAudio: FindNextComponent returned nullptr";
 		}
 
 		/* Open & initialize the default output audio unit */
@@ -126,7 +126,7 @@ const char *SoundDriver_Cocoa::Start(const char * const *parm)
 
 	/* Set the audio callback */
 	callback.inputProc = audioCallback;
-	callback.inputProcRefCon = NULL;
+	callback.inputProcRefCon = nullptr;
 	if (AudioUnitSetProperty(_outputAudioUnit, kAudioUnitProperty_SetRenderCallback, kAudioUnitScope_Input, 0, &callback, sizeof(callback)) != noErr) {
 		return "cocoa_s: Failed to start CoreAudio: AudioUnitSetProperty (kAudioUnitProperty_SetRenderCallback)";
 	}
@@ -137,7 +137,7 @@ const char *SoundDriver_Cocoa::Start(const char * const *parm)
 	}
 
 	/* We're running! */
-	return NULL;
+	return nullptr;
 }
 
 

src/sound/null_s.h

@@ -17,7 +17,7 @@
 /** Implementation of the null sound driver. */
 class SoundDriver_Null : public SoundDriver {
 public:
-	const char *Start(const char * const *param) override { return NULL; }
+	const char *Start(const char * const *param) override { return nullptr; }
 
 	void Stop() override { }
 	const char *GetName() const override { return "null"; }

src/sound/sdl_s.cpp

@@ -54,7 +54,7 @@ const char *SoundDriver_SDL::Start(const char * const *parm)
 	MxInitialize(spec.freq);
 	SDL_OpenAudio(&spec, &spec);
 	SDL_PauseAudio(0);
-	return NULL;
+	return nullptr;
 }
 
 void SoundDriver_SDL::Stop()

src/sound/win32_s.cpp

@@ -50,12 +50,12 @@ static DWORD WINAPI SoundThread(LPVOID arg)
 			if ((hdr->dwFlags & WHDR_INQUEUE) != 0) continue;
 			MxMixSamples(hdr->lpData, hdr->dwBufferLength / 4);
 			if (waveOutWrite(_waveout, hdr, sizeof(WAVEHDR)) != MMSYSERR_NOERROR) {
-				MessageBox(NULL, _T("Sounds are disabled until restart."), _T("waveOutWrite failed"), MB_ICONINFORMATION);
+				MessageBox(nullptr, _T("Sounds are disabled until restart."), _T("waveOutWrite failed"), MB_ICONINFORMATION);
 				return 0;
 			}
 		}
 		WaitForSingleObject(_event, INFINITE);
-	} while (_waveout != NULL);
+	} while (_waveout != nullptr);
 
 	return 0;
 }
@@ -75,7 +75,7 @@ const char *SoundDriver_Win32::Start(const char * const *parm)
 	_bufsize = min(_bufsize, UINT16_MAX);
 
 	try {
-		if (NULL == (_event = CreateEvent(NULL, FALSE, FALSE, NULL))) throw "Failed to create event";
+		if (nullptr == (_event = CreateEvent(nullptr, FALSE, FALSE, nullptr))) throw "Failed to create event";
 
 		if (waveOutOpen(&_waveout, WAVE_MAPPER, &wfex, (DWORD_PTR)_event, 0, CALLBACK_EVENT) != MMSYSERR_NOERROR) throw "waveOutOpen failed";
 
@@ -84,13 +84,13 @@ const char *SoundDriver_Win32::Start(const char * const *parm)
 		PrepareHeader(&_wave_hdr[0]);
 		PrepareHeader(&_wave_hdr[1]);
 
-		if (NULL == (_thread = CreateThread(NULL, 8192, SoundThread, 0, 0, &_threadId))) throw "Failed to create thread";
+		if (nullptr == (_thread = CreateThread(nullptr, 8192, SoundThread, 0, 0, &_threadId))) throw "Failed to create thread";
 	} catch (const char *error) {
 		this->Stop();
 		return error;
 	}
 
-	return NULL;
+	return nullptr;
 }
 
 void SoundDriver_Win32::Stop()
@@ -98,7 +98,7 @@ void SoundDriver_Win32::Stop()
 	HWAVEOUT waveout = _waveout;
 
 	/* Stop the sound thread. */
-	_waveout = NULL;
+	_waveout = nullptr;
 	SetEvent(_event);
 	WaitForSingleObject(_thread, INFINITE);
 

src/sound/xaudio2_s.cpp

@@ -125,7 +125,7 @@ static StreamingVoiceContext* _voice_context = nullptr;
 * Initialises the XAudio2 driver.
 *
 * @param parm Driver parameters.
-* @return An error message if unsuccessful, or NULL otherwise.
+* @return An error message if unsuccessful, or nullptr otherwise.
 *
 */
 const char *SoundDriver_XAudio2::Start(const char * const *parm)
@@ -140,7 +140,7 @@ const char *SoundDriver_XAudio2::Start(const char * const *parm)
 
 	_xaudio_dll_handle = LoadLibraryA(XAUDIO2_DLL_A);
 
-	if (_xaudio_dll_handle == NULL)
+	if (_xaudio_dll_handle == nullptr)
 	{
 		CoUninitialize();
 
@@ -150,7 +150,7 @@ const char *SoundDriver_XAudio2::Start(const char * const *parm)
 
 	API_XAudio2Create xAudio2Create = (API_XAudio2Create) GetProcAddress(_xaudio_dll_handle, "XAudio2Create");
 
-	if (xAudio2Create == NULL)
+	if (xAudio2Create == nullptr)
 	{
 		FreeLibrary(_xaudio_dll_handle);
 		CoUninitialize();
@@ -248,7 +248,7 @@ const char *SoundDriver_XAudio2::Start(const char * const *parm)
 		return "Failed to submit the first audio buffer";
 	}
 
-	return NULL;
+	return nullptr;
 }
 
 /**