Fix certain compilation warnings from Travis

src/AudacityApp.cpp

@@ -236,6 +236,7 @@ It handles initialization and termination by subclassing wxApp.
 DEFINE_EVENT_TYPE(EVT_OPEN_AUDIO_FILE);
 DEFINE_EVENT_TYPE(EVT_LANGUAGE_CHANGE);
 
+#if 0
 #ifdef __WXGTK__
 static void wxOnAssert(const wxChar *fileName, int lineNumber, const wxChar *msg)
 {
@@ -252,6 +253,7 @@ static void wxOnAssert(const wxChar *fileName, int lineNumber, const wxChar *msg
    exit(0);
 }
 #endif
+#endif
 
 static bool gInited = false;
 bool gIsQuitting = false;

src/AudioIO.cpp

@@ -2332,6 +2332,7 @@ void AudioIO::StopStream()
                      else
                         bResult = track->InsertSilence(mT0, recordingOffset); // put silence in
                      wxASSERT(bResult); // TO DO: Actually handle this.
+                     wxUnusedVar(bResult);
                   }
                   else
                   {  // recording into a NEW track

src/DirManager.cpp

@@ -583,7 +583,9 @@ wxFileName DirManager::MakeBlockFilePath(const wxString &value) {
       dir.AppendDir(middir);
 
       if(!dir.DirExists() && !dir.Mkdir(0777,wxPATH_MKDIR_FULL))
+      { // need braces to avoid compiler warning about ambiguous else, see the macro
          wxLogSysError(_("mkdir in DirManager::MakeBlockFilePath failed."));
+      }
    }
    return dir;
 }
@@ -1219,8 +1221,10 @@ bool DirManager::EnsureSafeFilename(wxFileName fName)
 
    wxFile testFile(renamedFileName.GetFullPath(), wxFile::write);
    if (!testFile.IsOpened()) {
-      wxLogSysError(_("Unable to open/create test file."),
+      { // need braces to avoid compiler warning about ambiguous else, see the macro
+         wxLogSysError(_("Unable to open/create test file."),
                     renamedFileName.GetFullPath().c_str());
+      }
       return false;
    }
 
@@ -1229,8 +1233,10 @@ bool DirManager::EnsureSafeFilename(wxFileName fName)
 
    if (!wxRemoveFile(renamedFileName.GetFullPath())) {
       /* i18n-hint: %s is the name of a file.*/
-      wxLogSysError(_("Unable to remove '%s'."),
+      { // need braces to avoid compiler warning about ambiguous else, see the macro
+         wxLogSysError(_("Unable to remove '%s'."),
                     renamedFileName.GetFullPath().c_str());
+      }
       return false;
    }
 

src/Menus.cpp

@@ -4156,6 +4156,7 @@ void AudacityProject::OnPaste()
                tmp = mTrackFactory->NewWaveTrack( ((WaveTrack*)n)->GetSampleFormat(), ((WaveTrack*)n)->GetRate());
                bool bResult = tmp->InsertSilence(0.0, msClipT1 - msClipT0); // MJS: Is this correct?
                wxASSERT(bResult); // TO DO: Actually handle this.
+               wxUnusedVar(bResult);
                tmp->Flush();
 
                bPastedSomething |=
@@ -4292,6 +4293,7 @@ bool AudacityProject::HandlePasteNothingSelected()
 
          bool bResult = pNewTrack->Paste(0.0, pClip);
          wxASSERT(bResult); // TO DO: Actually handle this.
+         wxUnusedVar(bResult);
          mTracks->Add(pNewTrack);
          pNewTrack->SetSelected(true);
 

src/Menus.h

@@ -327,7 +327,7 @@ void OnMixAndRenderToNewTrack();
 void HandleMixAndRender(bool toNewTrack);
 
 private:
-SelectedRegion mRegionSave;
+   SelectedRegion mRegionSave{};
 public:
 void OnSelectionSave();
 void OnSelectionRestore();

src/Project.cpp

@@ -789,8 +789,6 @@ AudacityProject::AudacityProject(wxWindow * parent, wxWindowID id,
                                  const wxPoint & pos,
                                  const wxSize & size)
    : wxFrame(parent, id, wxT("Audacity"), pos, size),
-     mRegionSave(),
-     mLastPlayMode(normalPlay),
      mRate((double) gPrefs->Read(wxT("/SamplingRate/DefaultProjectSampleRate"), AudioIO::GetOptimalSupportedSampleRate())),
      mDefaultFormat((sampleFormat) gPrefs->
            Read(wxT("/SamplingRate/DefaultProjectSampleFormat"), floatSample)),
@@ -799,43 +797,7 @@ AudacityProject::AudacityProject(wxWindow * parent, wxWindowID id,
      mFrequencySelectionFormatName(gPrefs->Read(wxT("/FrequencySelectionFormatName"), wxT(""))),
      mBandwidthSelectionFormatName(gPrefs->Read(wxT("/BandwidthSelectionFormatName"), wxT(""))),
      mUndoManager(safenew UndoManager),
-     mDirty(false),
+     mViewInfo(0.0, 1.0, ZoomInfo::GetDefaultZoom())
-     mRuler(NULL),
-     mTrackPanel(NULL),
-     mTrackFactory(NULL),
-     mAutoScrolling(false),
-     mActive(true),
-     mHistoryWindow(NULL),
-     mLyricsWindow(NULL),
-     mMixerBoard(NULL),
-     mMixerBoardFrame(NULL),
-     mFreqWindow(NULL),
-     mContrastDialog(NULL),
-     mAliasMissingWarningDialog(NULL),
-     mPlaybackMeter(NULL),
-     mCaptureMeter(NULL),
-     mToolManager(NULL),
-     mbBusyImporting(false),
-     mAudioIOToken(-1),
-     mIsDeleting(false),
-     mTracksFitVerticallyZoomed(false),  //lda
-     mShowId3Dialog(true),               //lda
-     mLastFocusedWindow(NULL),
-     mKeyboardCaptureHandler(NULL),
-     mImportXMLTagHandler(NULL),
-     mAutoSaving(false),
-     mIsRecovered(false),
-     mIsCapturing(false),
-     mRecordingRecoveryHandler(NULL),
-     mImportedDependencies(false),
-     mWantSaveCompressed(false),
-     mLastEffect(wxEmptyString),
-     mTimerRecordCanceled(false),
-     mMenuClose(false),
-     mShownOnce(false),
-     mbInitializingScrollbar(false),
-     mViewInfo(0.0, 1.0, ZoomInfo::GetDefaultZoom()),
-     mIsBeingDeleted(false)
 {
    // Note that the first field of the status bar is a dummy, and it's width is set
    // to zero latter in the code. This field is needed for wxWidgets 2.8.12 because
@@ -4658,6 +4620,7 @@ void AudacityProject::EditClipboardByLabel( EditDestFunction action )
 
                   bool bResult = merged->Paste( 0.0 , dest );
                   wxASSERT(bResult); // TO DO: Actually handle this.
+                  wxUnusedVar(bResult);
                   delete dest;
                }
             }

src/Project.h

@@ -473,7 +473,7 @@ public:
 
    void WriteXMLHeader(XMLWriter &xmlFile);
 
-   PlayMode mLastPlayMode;
+   PlayMode mLastPlayMode{ normalPlay };
    ViewInfo mViewInfo;
 
    // Audio IO callback methods
@@ -553,7 +553,7 @@ public:
 
    // History/Undo manager
    std::unique_ptr<UndoManager> mUndoManager;
-   bool mDirty;
+   bool mDirty{ false };
 
    // Commands
 
@@ -568,39 +568,39 @@ public:
 
    wxStatusBar *mStatusBar;
 
-   AdornedRulerPanel *mRuler;
+   AdornedRulerPanel *mRuler{};
-   TrackPanel *mTrackPanel;
+   TrackPanel *mTrackPanel{};
-   TrackFactory *mTrackFactory;
+   TrackFactory *mTrackFactory{};
    wxPanel * mMainPanel;
    wxScrollBar *mHsbar;
    wxScrollBar *mVsbar;
-   bool mAutoScrolling;
+   bool mAutoScrolling{ false };
-   bool mActive;
+   bool mActive{ true };
    bool mIconized;
 
-   HistoryWindow *mHistoryWindow;
+   HistoryWindow *mHistoryWindow{};
-   LyricsWindow* mLyricsWindow;
+   LyricsWindow* mLyricsWindow{};
-   MixerBoard* mMixerBoard;
+   MixerBoard* mMixerBoard{};
-   MixerBoardFrame* mMixerBoardFrame;
+   MixerBoardFrame* mMixerBoardFrame{};
 
-   FreqWindow *mFreqWindow;
+   FreqWindow *mFreqWindow{};
-   ContrastDialog *mContrastDialog;
+   ContrastDialog *mContrastDialog{};
 
    // dialog for missing alias warnings
-   wxDialog            *mAliasMissingWarningDialog;
+   wxDialog            *mAliasMissingWarningDialog{};
 
-   bool mShownOnce;
+   bool mShownOnce{ false };
 
    // Project owned meters
-   Meter *mPlaybackMeter;
+   Meter *mPlaybackMeter{};
-   Meter *mCaptureMeter;
+   Meter *mCaptureMeter{};
 
  public:
-   ToolManager *mToolManager;
+    ToolManager *mToolManager{};
    bool mShowSplashScreen;
    wxString mHelpPref;
    wxString mSoloPref;
-   bool mbBusyImporting; // used to fix bug 584
+   bool mbBusyImporting{ false }; // used to fix bug 584
 
    void SetNormalizedWindowState(wxRect pSizeAndLocation) {  mNormalizedWindowState = pSizeAndLocation;   }
    wxRect GetNormalizedWindowState() const { return mNormalizedWindowState;   }
@@ -615,12 +615,12 @@ public:
 #define kAudacitySortByName (1 << 2)
    void SortTracks(int flags);
 
-   int  mAudioIOToken;
+   int  mAudioIOToken{ -1 };
 
-   bool mIsDeleting;
+   bool mIsDeleting{ false };
-   bool mTracksFitVerticallyZoomed;  //lda
+   bool mTracksFitVerticallyZoomed{ false };  //lda
    bool mNormalizeOnLoad;  //lda
-   bool mShowId3Dialog; //lda
+   bool mShowId3Dialog{ true }; //lda
    bool mEmptyCanBeDirty;
 
    bool mSelectAllOnNone;
@@ -630,33 +630,33 @@ public:
    bool mLockPlayRegion;
 
    // See AudacityProject::OnActivate() for an explanation of this.
-   wxWindow *mLastFocusedWindow;
+   wxWindow *mLastFocusedWindow{};
 
-   ImportXMLTagHandler* mImportXMLTagHandler;
+   ImportXMLTagHandler* mImportXMLTagHandler{};
 
    // Last auto-save file name and path (empty if none)
    wxString mAutoSaveFileName;
 
    // Are we currently auto-saving or not?
-   bool mAutoSaving;
+   bool mAutoSaving{ false };
 
    // Has this project been recovered from an auto-saved version
-   bool mIsRecovered;
+   bool mIsRecovered{ false };
 
    // The auto-save data dir the project has been recovered from
    wxString mRecoveryAutoSaveDataDir;
 
    // The handler that handles recovery of <recordingrecovery> tags
-   RecordingRecoveryHandler* mRecordingRecoveryHandler;
+   RecordingRecoveryHandler* mRecordingRecoveryHandler{};
 
    // Dependencies have been imported and a warning should be shown on save
-   bool mImportedDependencies;
+   bool mImportedDependencies{ false };
 
-   bool mWantSaveCompressed;
+   bool mWantSaveCompressed{ false };
    wxArrayString mStrOtherNamesArray; // used to make sure compressed file names are unique
 
    // Last effect applied to this project
-   PluginID mLastEffect;
+   PluginID mLastEffect{};
    
    // The screenshot class needs to access internals
    friend class ScreenshotCommand;
@@ -664,18 +664,18 @@ public:
    wxRect mNormalizedWindowState;
 
    //flag for cancellation of timer record.
-   bool mTimerRecordCanceled;
+   bool mTimerRecordCanceled{ false  };
 
    // Are we currently closing as the result of a menu command?
-   bool mMenuClose;
+   bool mMenuClose{ false };
 
-   bool mbInitializingScrollbar;
+   bool mbInitializingScrollbar{ false };
 
    // Flag that we're recoding.
-   bool mIsCapturing;
+   bool mIsCapturing{ false };
 
    // Keyboard capture
-   wxWindow *mKeyboardCaptureHandler;
+   wxWindow *mKeyboardCaptureHandler{};
 
    double mSeekShort;
    double mSeekLong;
@@ -683,7 +683,7 @@ public:
    wxLongLong mLastSelectionAdjustment;
 
    // See explanation in OnCloseWindow
-   bool mIsBeingDeleted;
+   bool mIsBeingDeleted{ false };
 
    // CommandManager needs to use private methods
    friend class CommandManager;

src/Sequence.cpp

@@ -55,10 +55,8 @@ int Sequence::sMaxDiskBlockSize = 1048576;
 Sequence::Sequence(DirManager * projDirManager, sampleFormat format)
    : mDirManager(projDirManager)
    , mSampleFormat(format)
-   , mNumSamples(0)
    , mMinSamples(sMaxDiskBlockSize / SAMPLE_SIZE(mSampleFormat) / 2)
    , mMaxSamples(mMinSamples * 2)
-   , mErrorOpening(false)
 {
    mDirManager->Ref();
 }
@@ -68,11 +66,9 @@ Sequence::Sequence(DirManager * projDirManager, sampleFormat format)
 // from one project to another
 Sequence::Sequence(const Sequence &orig, DirManager *projDirManager)
    : mDirManager(projDirManager)
-   , mNumSamples(0)
    , mSampleFormat(orig.mSampleFormat)
    , mMinSamples(orig.mMinSamples)
    , mMaxSamples(orig.mMaxSamples)
-   , mErrorOpening(false)
 {
    mDirManager->Ref();
 
@@ -418,11 +414,13 @@ bool Sequence::Copy(sampleCount s0, sampleCount s1, Sequence **dest)
       return false;
 
    int numBlocks = mBlock.size();
+
    int b0 = FindBlock(s0);
    const int b1 = FindBlock(s1 - 1);
    wxASSERT(b0 >= 0);
    wxASSERT(b0 < numBlocks);
    wxASSERT(b1 < numBlocks);
+   wxUnusedVar(numBlocks);
    wxASSERT(b0 <= b1);
 
    *dest = new Sequence(mDirManager, mSampleFormat);

src/Sequence.h

@@ -222,12 +222,12 @@ class PROFILE_DLL_API Sequence final : public XMLTagHandler{
 
    BlockArray    mBlock;
    sampleFormat  mSampleFormat;
-   sampleCount   mNumSamples;
+   sampleCount   mNumSamples{ 0 };
 
    sampleCount   mMinSamples; // min samples per block
    sampleCount   mMaxSamples; // max samples per block
 
-   bool          mErrorOpening;
+   bool          mErrorOpening{ false };
 
    ///To block the Delete() method against the ODCalcSummaryTask::Update() method
    ODLock   mDeleteUpdateMutex;

src/TrackArtist.cpp

@@ -471,6 +471,8 @@ void TrackArtist::DrawTrack(const Track * t,
       case WaveTrack::Spectrum:
          DrawSpectrum(wt, dc, rect, selectedRegion, zoomInfo);
          break;
+      default:
+         wxASSERT(false);
       }
 
 #if defined(__WXMAC__)
@@ -835,7 +837,7 @@ void TrackArtist::UpdateVRuler(Track *t, wxRect & rect)
          float minFreq, maxFreq;
          wt->GetSpectrumBounds(&minFreq, &maxFreq);
 
-         switch (wt->GetSpectrogramSettings().scaleType) {
+         switch (settings.scaleType) {
          default:
             wxASSERT(false);
          case SpectrogramSettings::stLinear:

src/WaveTrack.cpp

@@ -912,6 +912,7 @@ bool WaveTrack::ClearAndPaste(double t0, // Start of time to clear
                   if (i > 0) {
                      bool bResult = MergeClips(GetClipIndex(clips[i - 1]), GetClipIndex(clip));
                      wxASSERT(bResult); // TO DO: Actually handle this.
+                     wxUnusedVar(bResult);
                   }
                   break;
                }
@@ -931,6 +932,7 @@ bool WaveTrack::ClearAndPaste(double t0, // Start of time to clear
                   if (i < clips.GetCount() - 1) {
                      bool bResult = MergeClips(GetClipIndex(clip), GetClipIndex(clips[i + 1]));
                      wxASSERT(bResult); // TO DO: Actually handle this.
+                     wxUnusedVar(bResult);
                   }
                   break;
                }
@@ -1170,9 +1172,11 @@ bool WaveTrack::SyncLockAdjust(double oldT1, double newT1)
 
          bool bResult = tmp->InsertSilence(0.0, newT1 - oldT1);
          wxASSERT(bResult); // TO DO: Actually handle this.
+         wxUnusedVar(bResult);
          tmp->Flush();
          bResult = Paste(oldT1, tmp);
          wxASSERT(bResult); // TO DO: Actually handle this.
+         wxUnusedVar(bResult);
          delete tmp;
       }
    }
@@ -1241,6 +1245,7 @@ bool WaveTrack::Paste(double t0, Track *src)
             Cut(t0, GetEndTime()+1.0/mRate, &tmp);
             bool bResult = Paste(t0 + insertDuration, tmp);
             wxASSERT(bResult); // TO DO: Actually handle this.
+            wxUnusedVar(bResult);
             delete tmp;
          }
       } else
@@ -1545,12 +1550,14 @@ bool WaveTrack::Join(double t0, double t1)
          //printf("Adding %.6f seconds of silence\n");
          bool bResult = newClip->InsertSilence(t, addedSilence);
          wxASSERT(bResult); // TO DO: Actually handle this.
+         wxUnusedVar(bResult);
          t += addedSilence;
       }
 
       //printf("Pasting at %.6f\n", t);
       bool bResult = newClip->Paste(t, clip);
       wxASSERT(bResult); // TO DO: Actually handle this.
+      wxUnusedVar(bResult);
       t = newClip->GetEndTime();
 
       mClips.DeleteObject(clip);

src/blockfile/ODDecodeBlockFile.cpp

@@ -339,6 +339,7 @@ int ODDecodeBlockFile::WriteODDecodeBlockFile()
          mFormat,
          NULL);//summaryData);
    wxASSERT(bSuccess); // TODO: Handle failure here by alert to user and undo partial op.
+   wxUnusedVar(bSuccess);
 
    mFileNameMutex.Unlock();
 

src/blockfile/SimpleBlockFile.cpp

@@ -111,6 +111,7 @@ SimpleBlockFile::SimpleBlockFile(wxFileName baseFileName,
    {
       bool bSuccess = WriteSimpleBlockFile(sampleData, sampleLen, format, NULL);
       wxASSERT(bSuccess); // TODO: Handle failure here by alert to user and undo partial op.
+      wxUnusedVar(bSuccess);
    }
 
    if (useCache) {

src/commands/CommandManager.cpp

@@ -971,8 +971,6 @@ void CommandManager::Enable(const wxString &name, bool enabled)
 
 void CommandManager::EnableUsingFlags(wxUint32 flags, wxUint32 mask)
 {
-   unsigned int i;
-
    for(const auto &entry : mCommandList) {
       if (entry->multi && entry->index != 0)
          continue;
@@ -1158,8 +1156,6 @@ bool CommandManager::HandleMenuID(int id, wxUint32 flags, wxUint32 mask)
 /// code to run.
 bool CommandManager::HandleTextualCommand(wxString & Str, wxUint32 flags, wxUint32 mask)
 {
-   unsigned int i;
-
    // Linear search for now...
    for (const auto &entry : mCommandList)
    {

src/effects/Effect.cpp

@@ -1731,6 +1731,7 @@ bool Effect::ProcessTrack(int count,
          return false;
       }
       wxASSERT(processed == curBlockSize);
+      wxUnusedVar(processed);
 
       // Bump to next input buffer position
       if (inputRemaining)

src/effects/Effect.h

@@ -684,6 +684,9 @@ inline long TrapLong(long x, long min, long max)
 
 #define ReadBasic(type, name) \
    type name; \
+   wxUnusedVar(MIN_ ##name); \
+   wxUnusedVar(MAX_ ##name); \
+   wxUnusedVar(SCL_ ##name); \
    if (!parms.ReadAndVerify(KEY_ ## name, &name, DEF_ ## name)) \
       return false;
 

src/effects/Equalization.cpp

@@ -1204,6 +1204,7 @@ bool EffectEqualization::ProcessOne(int count, WaveTrack * t,
             //put the processed audio in
             bool bResult = t->Paste(clipStartEndTimes[i].first, toClipOutput);
             wxASSERT(bResult); // TO DO: Actually handle this.
+            wxUnusedVar(bResult);
             //if the clip was only partially selected, the Paste will have created a split line.  Join is needed to take care of this
             //This is not true when the selection is fully contained within one clip (second half of conditional)
             if( (clipRealStartEndTimes[i].first  != clipStartEndTimes[i].first ||

src/effects/NoiseReduction.cpp

@@ -1336,6 +1336,7 @@ bool EffectNoiseReduction::Worker::ProcessOne
       outputTrack->HandleClear(tLen, outputTrack->GetEndTime(), false, false);
       bool bResult = track->ClearAndPaste(t0, t0 + tLen, &*outputTrack, true, false);
       wxASSERT(bResult); // TO DO: Actually handle this.
+      wxUnusedVar(bResult);
    }
 
    return bLoopSuccess;

src/effects/SBSMSEffect.cpp

@@ -416,6 +416,7 @@ bool EffectSBSMS::Process()
                leftTrack->ClearAndPaste(mCurT0, mCurT1, rb.outputLeftTrack,
                                           true, false, GetTimeWarper());
             wxASSERT(bResult); // TO DO: Actually handle this.
+            wxUnusedVar(bResult);
 
             if(rightTrack)
             {

src/effects/VST/VSTControlGTK.cpp

@@ -13,11 +13,13 @@
 
 #include "VSTControl.h"
 
+#if 0
 static int trappedErrorCode = 0;
 static int X11TrapHandler(Display *, XErrorEvent *err)
 {
     return 0;
 }
+#endif
 
 VSTControl::VSTControl()
 :  VSTControlBase()

src/effects/ladspa/LadspaEffect.cpp

@@ -1409,6 +1409,8 @@ bool LadspaEffect::PopulateUI(wxWindow *parent)
             wxString bound;
             float lower = 0.0;
             float upper = 1.0;
+
+            /*
             bool haslo = false;
             bool hashi = false;
             bool forceint = false;
@@ -1431,6 +1433,7 @@ bool LadspaEffect::PopulateUI(wxWindow *parent)
                upper *= mSampleRate;
                forceint = true;
             }
+            */
 
             // Limit to the UI precision
             lower = ceilf(lower * 1000000.0) / 1000000.0;

src/effects/vamp/LoadVamp.cpp

@@ -266,7 +266,7 @@ Plugin *VampEffectsModule::FindPlugin(const wxString & path,
    Plugin *vp = PluginLoader::getInstance()->loadPlugin(key, 48000); // rate doesn't matter here
    if (!vp)
    {
-      return false;
+      return nullptr;
    }
 
    // We limit the listed plugin outputs to those whose results can

src/export/ExportFFmpeg.cpp

@@ -589,6 +589,12 @@ static int encode_audio(AVCodecContext *avctx, AVPacket *pkt, int16_t *audio_sam
             case AV_SAMPLE_FMT_FLTP:
                ((float*)(frame->data[ch]))[i] = audio_samples[ch + i*avctx->channels] / 32767.;
                break;
+            case AV_SAMPLE_FMT_NONE:
+            case AV_SAMPLE_FMT_DBL:
+            case AV_SAMPLE_FMT_DBLP:
+            case AV_SAMPLE_FMT_NB:
+               wxASSERT(false);
+               break;
             }
          }
       }

src/import/ImportFLAC.cpp

@@ -215,6 +215,9 @@ void MyFLACFile::metadata_callback(const FLAC__StreamMetadata *metadata)
       case FLAC__METADATA_TYPE_PICTURE:		// ignore pictures
       case FLAC__METADATA_TYPE_UNDEFINED:	// do nothing with this either
       break;
+
+      case FLAC__MAX_METADATA_TYPE: // suppress compiler warning
+         wxASSERT(false);
    }
 }
 
@@ -296,7 +299,7 @@ ImportFileHandle *FLACImportPlugin::Open(const wxString &filename)
    int cnt;
    wxFile binaryFile;
    if (!binaryFile.Open(filename)) {
-      return false; // File not found
+      return nullptr; // File not found
    }
 
 #ifdef USE_LIBID3TAG
@@ -313,7 +316,7 @@ ImportFileHandle *FLACImportPlugin::Open(const wxString &filename)
 
    if (cnt == wxInvalidOffset || strncmp(buf, FLAC_HEADER, 4) != 0) {
       // File is not a FLAC file
-      return false;
+      return nullptr;
    }
 
    // Open the file for import
@@ -322,7 +325,7 @@ ImportFileHandle *FLACImportPlugin::Open(const wxString &filename)
    bool success = handle->Init();
    if (!success) {
       delete handle;
-      return NULL;
+      return nullptr;
    }
 
    return handle;
@@ -476,6 +479,7 @@ int FLACImportFileHandle::Import(TrackFactory *trackFactory,
       if(!useOD)
          res = (mFile->process_until_end_of_stream() != 0);
    #endif
+      wxUnusedVar(res);
 
    //add the task to the ODManager
    if(useOD)

src/import/ImportOGG.cpp

@@ -173,6 +173,12 @@ wxString OggImportPlugin::GetPluginFormatDescription()
 
 ImportFileHandle *OggImportPlugin::Open(const wxString &filename)
 {
+   // Suppress some compiler warnings about unused global variables in the library header
+   wxUnusedVar(OV_CALLBACKS_DEFAULT);
+   wxUnusedVar(OV_CALLBACKS_NOCLOSE);
+   wxUnusedVar(OV_CALLBACKS_STREAMONLY);
+   wxUnusedVar(OV_CALLBACKS_STREAMONLY_NOCLOSE);
+
    OggVorbis_File *vorbisFile = new OggVorbis_File;
    wxFFile *file = new wxFFile(filename, wxT("rb"));
 

src/ondemand/ODDecodeFlacTask.cpp

@@ -79,6 +79,9 @@ void ODFLACFile::metadata_callback(const FLAC__StreamMetadata *metadata)
       case FLAC__METADATA_TYPE_PICTURE:		// ignore pictures
       case FLAC__METADATA_TYPE_UNDEFINED:	// do nothing with this either
       break;
+
+      case FLAC__MAX_METADATA_TYPE: // suppress compiler warning
+         break;
    }
 }
 

src/prefs/PrefsDialog.cpp

@@ -204,8 +204,6 @@ PrefsDialog::PrefsDialog
             wxDefaultSize,
             wxDEFAULT_DIALOG_STYLE | wxRESIZE_BORDER)
 , mFactories(factories)
-, mCategories(NULL)
-, mUniquePage(NULL)
 , mTitlePrefix(titlePrefix)
 {
    wxASSERT(factories.size() > 0);

src/prefs/PrefsDialog.h

@@ -76,8 +76,8 @@ class PrefsDialog /* not final */ : public wxDialog
 
 private:
    void RecordExpansionState();
-   wxTreebook *mCategories;
+   wxTreebook *mCategories{};
-   PrefsPanel *mUniquePage;
+   PrefsPanel *mUniquePage{};
    Factories &mFactories;
    const wxString mTitlePrefix;
 

src/prefs/SpectrogramSettings.cpp

@@ -57,10 +57,6 @@ SpectrogramSettings::Globals
 }
 
 SpectrogramSettings::SpectrogramSettings()
-   : hFFT(0)
-   , window(0)
-   , dWindow(0)
-   , tWindow(0)
 {
    LoadPrefs();
 }
@@ -93,10 +89,10 @@ SpectrogramSettings::SpectrogramSettings(const SpectrogramSettings &other)
 #endif
 
    // Do not copy these!
-   , hFFT(0)
+   , hFFT{}
-   , window(0)
+   , window{}
-   , tWindow(0)
+   , tWindow{}
-   , dWindow(0)
+   , dWindow{}
 {
 }
 

src/prefs/SpectrogramSettings.h

@@ -139,12 +139,12 @@ public:
 
 #ifdef EXPERIMENTAL_USE_REALFFTF
    // Variables used for computing the spectrum
-   mutable FFTParam      *hFFT;
+   mutable FFTParam      *hFFT{};
-   mutable float         *window;
+   mutable float         *window{};
 
    // Two other windows for computing reassigned spectrogram
-   mutable float         *tWindow; // Window times time parameter
+   mutable float         *tWindow{}; // Window times time parameter
-   mutable float         *dWindow; // Derivative of window
+   mutable float         *dWindow{}; // Derivative of window
 
 #endif
 };

src/prefs/WaveformSettings.cpp

@@ -70,10 +70,8 @@ WaveformSettings& WaveformSettings::defaults()
    return instance;
 }
 
-bool WaveformSettings::Validate(bool quiet)
+bool WaveformSettings::Validate(bool /* quiet */)
 {
-   quiet;
-
    scaleType = ScaleType(
       std::max(0, std::min(int(stNumScaleTypes) - 1, int(scaleType)))
    );

src/toolbars/ControlToolBar.cpp

@@ -889,6 +889,7 @@ void ControlToolBar::OnRecord(wxCommandEvent &evt)
                   wt->Clear(t1, t0);
                   bool bResult = wt->Paste(t1, newTrack);
                   wxASSERT(bResult); // TO DO: Actually handle this.
+                  wxUnusedVar(bResult);
                   delete newTrack;
                }
                newRecordingTracks.Add(wt);

src/widgets/Meter.cpp

@@ -237,6 +237,11 @@ Meter::Meter(AudacityProject *project,
    mIcon(NULL),
    mAccSilent(false)
 {
+   // Suppress warnings about the header file
+   wxUnusedVar(SpeakerMenu_xpm);
+   wxUnusedVar(MicMenu_xpm);
+   wxUnusedVar(PrefStyles);
+
    mStyle = mDesiredStyle;
 
    mIsFocused = false;