ENH: Explicitly recognize virtual functions

    clang-tidy tool can insert missing override keyword as a macro so that missing [optional] virtual identifiers can be easily added.

    build otb with clang 3.8 and use cmake option CMAKE_EXPORT_COMPILE_COMMANDS=ON. Most modules and third parties have been activated.

    #Save override occurences in otb code
    cd src/Modules ; grep -nR "override" * > ~/temporary/override_otb.txt

    #Run clang modernize check using utility script which allow to process the code in parallel
    python run-clang-tidy.py -clang-tidy-binary ~/software/clang+llvm-3.8.0-x86_64-linux-gnu-ubuntu-14.04/bin/clang-tidy -checks=-*,modernize-use-override -header-filter=/home/grizonnetm/projets/otb/src/OTB/Modules/.*/.*/include/.* -j8 -fix -p ~/projets/otb/bin/release/OTB-clang3.8/ ~/projets/otb/src/OTB/Modules/*/*/src/*.cxx ~/projets/otb/src/OTB/Examples/*/*.cxx ~/projets/otb/src/OTB/Modules/*/*/test/*.cxx > ~/temporary/run-clang-tidy-log.txt

    #Replace override by ITK macro (to maintain compat with c++98)
    find . -type f -print -name "*.h" -o -name "*.txx" |xargs perl -pi -e 's/\ override/\ ITK_OVERRIDE/g'

Examples/Application/ApplicationExample.cxx

@@ -97,7 +97,7 @@ private:
   //  \code{DoInit()} method contains class information and description, parameter set up, and example values.
   //  Software Guide : EndLatex
 
-  void DoInit()
+  void DoInit() override
   {
 
     // Software Guide : BeginLatex
@@ -228,7 +228,7 @@ private:
   // gives a complete description of this method.
   // Software Guide : EndLatex
   //  Software Guide :BeginCodeSnippet
-  void DoUpdateParameters()
+  void DoUpdateParameters() override
   {
   }
   //  Software Guide : EndCodeSnippet
@@ -238,7 +238,7 @@ private:
   // gives a complete description of this method.
   // Software Guide : EndLatex
   //  Software Guide :BeginCodeSnippet
-  void DoExecute()
+  void DoExecute() override
   {
     FloatVectorImageType::Pointer inImage = GetParameterImage("in");
 

Examples/ChangeDetection/ChangeDetectionFrameworkExample.cxx

@@ -138,7 +138,7 @@ public:
 
 protected:
   MyChangeDetectorImageFilter() {}
-  virtual ~MyChangeDetectorImageFilter() {}
+  ~MyChangeDetectorImageFilter() override {}
 
 private:
   MyChangeDetectorImageFilter(const Self &); //purposely not implemented

Examples/Filtering/CompositeFilterExample.cxx

@@ -93,7 +93,7 @@ public:
   itkTypeMacro(CompositeExampleImageFilter, itk::ImageToImageFilter);
 
   /** Display */
-  void PrintSelf(std::ostream& os, itk::Indent indent) const;
+  void PrintSelf(std::ostream& os, itk::Indent indent) const override;
 
 //  Software Guide : BeginLatex
 //
@@ -132,7 +132,7 @@ protected:
   RescalerType;
 //  Software Guide : EndCodeSnippet
 
-  void GenerateData();
+  void GenerateData() override;
 
 private:
 

Examples/Filtering/GeometriesChangeSpatialReference.cxx

@@ -99,11 +99,11 @@ protected:
   /** Default constructor. */
   MyReprojectionFilter(){ }
   /** Destructor. */
-  virtual ~MyReprojectionFilter(){ }
+  ~MyReprojectionFilter() override{ }
 
 private:
 
-  virtual OGRSpatialReference*     DoDefineNewLayerSpatialReference(otb::ogr::Layer const& itkNotUsed(source)) const
+  OGRSpatialReference*     DoDefineNewLayerSpatialReference(otb::ogr::Layer const& itkNotUsed(source)) const override
     {
     return m_osr.get();
     }

Examples/Registration/ImageRegistration1.cxx

@@ -78,12 +78,12 @@ public:
   typedef itk::RegularStepGradientDescentOptimizer OptimizerType;
   typedef const OptimizerType *                    OptimizerPointer;
 
-  void Execute(itk::Object *caller, const itk::EventObject& event)
+  void Execute(itk::Object *caller, const itk::EventObject& event) override
   {
     Execute((const itk::Object *) caller, event);
   }
 
-  void Execute(const itk::Object * object, const itk::EventObject& event)
+  void Execute(const itk::Object * object, const itk::EventObject& event) override
   {
     OptimizerPointer optimizer =
       dynamic_cast<OptimizerPointer>(object);

Examples/Registration/ImageRegistration2.cxx

@@ -97,12 +97,12 @@ public:
   typedef   itk::GradientDescentOptimizer OptimizerType;
   typedef   const OptimizerType *         OptimizerPointer;
 
-  void Execute(itk::Object *caller, const itk::EventObject& event)
+  void Execute(itk::Object *caller, const itk::EventObject& event) override
   {
     Execute((const itk::Object *) caller, event);
   }
 
-  void Execute(const itk::Object * object, const itk::EventObject& event)
+  void Execute(const itk::Object * object, const itk::EventObject& event) override
   {
     OptimizerPointer optimizer =
       dynamic_cast<OptimizerPointer>(object);

Examples/Registration/ImageRegistration5.cxx

@@ -92,12 +92,12 @@ public:
   typedef itk::RegularStepGradientDescentOptimizer OptimizerType;
   typedef   const OptimizerType *                  OptimizerPointer;
 
-  void Execute(itk::Object *caller, const itk::EventObject& event)
+  void Execute(itk::Object *caller, const itk::EventObject& event) override
   {
     Execute((const itk::Object *) caller, event);
   }
 
-  void Execute(const itk::Object * object, const itk::EventObject& event)
+  void Execute(const itk::Object * object, const itk::EventObject& event) override
   {
     OptimizerPointer optimizer =
       dynamic_cast<OptimizerPointer>(object);

Examples/Registration/ImageRegistration9.cxx

@@ -87,12 +87,12 @@ public:
   typedef itk::RegularStepGradientDescentOptimizer OptimizerType;
   typedef   const OptimizerType *                  OptimizerPointer;
 
-  void Execute(itk::Object *caller, const itk::EventObject& event)
+  void Execute(itk::Object *caller, const itk::EventObject& event) override
   {
     Execute((const itk::Object *) caller, event);
   }
 
-  void Execute(const itk::Object * object, const itk::EventObject& event)
+  void Execute(const itk::Object * object, const itk::EventObject& event) override
   {
     OptimizerPointer optimizer =
       dynamic_cast<OptimizerPointer>(object);

Examples/Simulation/LAIAndPROSAILToSensorResponse.cxx

@@ -132,10 +132,10 @@ protected:
     {
     m_Image = NULL;