Use override keyword were necessary

To avoid future mistakes when overriding functions, this commit suggests
to use the `override` keyword as suggested by clang-tidy.

How this commit was produced:

1. Compile with CMake, exporting the compile commands as described here:
   https://stackoverflow.com/questions/20059670/how-to-use-cmake-export-compile-commands

2. Build

3. Run this in the build directory:
   ```
   run-clang-tidy -header-filter="interface/.*" -config-file=../.clang-tidy -export-fixes
 fixes.yaml . -j20
   ```

4. Copy the `fixes.yaml` back to the main repo and apply fixes with:
   ```
   clang-apply-replacements .
   ```

5. Replace `ClassDef` macros with `ClassDefOverride` to be consistent.

.clang-tidy

@@ -0,0 +1,6 @@
+---
+Checks: -*,
+  ,modernize-use-override,
+WarningsAsErrors: '*'
+HeaderFilterRegex: ''
+...

interface/AsymPow.h

@@ -26,12 +26,12 @@ class AsymPow : public RooAbsReal {
       AsymPow(const char *name, const char *title, RooAbsReal &kappaLow, RooAbsReal &kappaHigh, RooAbsReal &theta) ;
       AsymPow(const AsymPow &other, const char *newname=0) ;
 
-      ~AsymPow() ;
+      ~AsymPow() override ;
 
-      TObject * clone(const char *newname) const ;
+      TObject * clone(const char *newname) const override ;
 
     protected:
-        Double_t evaluate() const;
+        Double_t evaluate() const override;
 
     private:
         RooRealProxy kappaLow_, kappaHigh_;
@@ -40,7 +40,7 @@ class AsymPow : public RooAbsReal {
         // get the kappa for the appropriate x
         Double_t logKappaForX(Double_t x) const ;
 
-  ClassDef(AsymPow,1) // Asymmetric power	
+  ClassDefOverride(AsymPow,1) // Asymmetric power	
 };
 
 #endif

interface/AsymptoticLimits.h

@@ -22,16 +22,16 @@ class RooRealVar;
 class AsymptoticLimits : public LimitAlgo {
 public:
   AsymptoticLimits() ; 
-  virtual void applyOptions(const boost::program_options::variables_map &vm) ;
-  virtual void applyDefaultOptions() ; 
+  void applyOptions(const boost::program_options::variables_map &vm) override ;
+  void applyDefaultOptions() override ; 
 
-  virtual bool run(RooWorkspace *w, RooStats::ModelConfig *mc_s, RooStats::ModelConfig *mc_b, RooAbsData &data, double &limit, double &limitErr, const double *hint);
+  bool run(RooWorkspace *w, RooStats::ModelConfig *mc_s, RooStats::ModelConfig *mc_b, RooAbsData &data, double &limit, double &limitErr, const double *hint) override;
   virtual bool runLimit(RooWorkspace *w, RooStats::ModelConfig *mc_s, RooStats::ModelConfig *mc_b, RooAbsData &data, double &limit, double &limitErr, const double *hint);
   std::vector<std::pair<float,float> > runLimitExpected(RooWorkspace *w, RooStats::ModelConfig *mc_s, RooStats::ModelConfig *mc_b, RooAbsData &data, double &limit, double &limitErr, const double *hint) ;
 
   float findExpectedLimitFromCrossing(RooAbsReal &nll, RooRealVar *r, double rMin, double rMax, double nll0, double quantile) ; 
 
-  virtual const std::string& name() const { static std::string name_ = "AsymptoticLimits"; return name_; }
+  const std::string& name() const override { static std::string name_ = "AsymptoticLimits"; return name_; }
 private:
   static double rAbsAccuracy_, rRelAccuracy_;
   static std::string what_;

interface/AtlasPdfs.h

@@ -34,8 +34,8 @@ namespace HistFactory{
     RooBSplineBases(const char *name, const char *title);
     RooBSplineBases(const RooBSplineBases&, const char*);
 
-    virtual TObject* clone(const char* newname) const { return new RooBSplineBases(*this, newname); }
-    virtual ~RooBSplineBases() ;
+    TObject* clone(const char* newname) const override { return new RooBSplineBases(*this, newname); }
+    ~RooBSplineBases() override ;
 
 /*     Double_t getCurvature() const; */
 
@@ -62,9 +62,9 @@ namespace HistFactory{
     mutable std::vector<double> _t_ary;
     mutable std::vector<std::vector<double> > _bin;
 
-    Double_t evaluate() const;
+    Double_t evaluate() const override;
 
-    ClassDef(RooStats::HistFactory::RooBSplineBases,1) // Uniform B-Spline
+    ClassDefOverride(RooStats::HistFactory::RooBSplineBases,1) // Uniform B-Spline
   };
 }
 }
@@ -116,8 +116,8 @@ namespace HistFactory{
     RooBSpline(const char *name, const char *title);
     RooBSpline(const RooBSpline&, const char*);
 
-    virtual TObject* clone(const char* newname) const { return new RooBSpline(*this, newname); }
-    virtual ~RooBSpline() ;
+    TObject* clone(const char* newname) const override { return new RooBSpline(*this, newname); }
+    ~RooBSpline() override ;
 
 /*     Double_t getCurvature() const; */
 
@@ -127,8 +127,8 @@ namespace HistFactory{
     void setWeights(const RooArgList& weights);
 
     Bool_t setBinIntegrator(RooArgSet& allVars) ;
-    Int_t getAnalyticalIntegralWN(RooArgSet& allVars, RooArgSet& analVars, const RooArgSet* normSet,const char* rangeName=0) const ;
-    Double_t analyticalIntegralWN(Int_t code, const RooArgSet* normSet, const char* rangeName=0) const ;
+    Int_t getAnalyticalIntegralWN(RooArgSet& allVars, RooArgSet& analVars, const RooArgSet* normSet,const char* rangeName=0) const override ;
+    Double_t analyticalIntegralWN(Int_t code, const RooArgSet* normSet, const char* rangeName=0) const override ;
 
     const RooArgList& getControlPoints() const {return _controlPoints;}
 
@@ -151,17 +151,17 @@ namespace HistFactory{
     // Cache the integrals   
     class CacheElem : public RooAbsCacheElement {
     public:
-      virtual ~CacheElem();
+      ~CacheElem() override;
       // Payload
       RooArgList _I ;
-      virtual RooArgList containedArgs(Action) ;
+      RooArgList containedArgs(Action) override ;
     };
     mutable RooObjCacheManager _cacheMgr ; // The cache manager
 
 
-    Double_t evaluate() const;
+    Double_t evaluate() const override;
 
-    ClassDef(RooStats::HistFactory::RooBSpline,2) // Uniform B-Spline
+    ClassDefOverride(RooStats::HistFactory::RooBSpline,2) // Uniform B-Spline
   };
 }
 }
@@ -209,21 +209,21 @@ class RooParamKeysPdf : public RooAbsPdf {
     RooDataSet& data, Mirror mirror= NoMirror, Double_t rho=1, Int_t nPoints=1000
   );
   RooParamKeysPdf(const RooParamKeysPdf& other, const char* name=0);
-  virtual TObject* clone(const char* newname) const {return new RooParamKeysPdf(*this,newname); }
-  virtual ~RooParamKeysPdf();
+  TObject* clone(const char* newname) const override {return new RooParamKeysPdf(*this,newname); }
+  ~RooParamKeysPdf() override;
 
   void LoadDataSet( RooDataSet& data);
 
-  Int_t getAnalyticalIntegral(RooArgSet& allVars, RooArgSet& analVars, const char* rangeName=0) const ;
-  Double_t analyticalIntegral(Int_t code, const char* rangeName=0) const ;
+  Int_t getAnalyticalIntegral(RooArgSet& allVars, RooArgSet& analVars, const char* rangeName=0) const override ;
+  Double_t analyticalIntegral(Int_t code, const char* rangeName=0) const override ;
 
 protected:
 
   RooRealProxy _x ;
   RooRealProxy _deltax ;
   double _centralValue;
   RooRealProxy _multiplicativeShift;
-  Double_t evaluate() const;
+  Double_t evaluate() const override;
 
 private:
 
@@ -251,7 +251,7 @@ class RooParamKeysPdf : public RooAbsPdf {
   Double_t _lo, _hi, _binWidth;
   Double_t _rho;
 
-  ClassDef(RooParamKeysPdf,4) // One-dimensional non-parametric kernel estimation p.d.f.
+  ClassDefOverride(RooParamKeysPdf,4) // One-dimensional non-parametric kernel estimation p.d.f.
 };
 
 #ifdef __CINT__
@@ -304,15 +304,15 @@ class RooStarMomentMorph : public RooAbsPdf {
 
   RooStarMomentMorph(const RooStarMomentMorph& other, const char* name=0) ;
 
-  virtual TObject* clone(const char* newname) const { return new RooStarMomentMorph(*this,newname); }
+  TObject* clone(const char* newname) const override { return new RooStarMomentMorph(*this,newname); }
 
-  virtual ~RooStarMomentMorph();
+  ~RooStarMomentMorph() override;
 
   void     setMode(const Setting& setting) { _setting = setting; }
 
   int nnuisSize() { return _nnuis.size(); }
 
-  virtual Bool_t selfNormalized() const { 
+  Bool_t selfNormalized() const override { 
     // P.d.f is self normalized
     return kTRUE ; 
   }
@@ -325,7 +325,7 @@ class RooStarMomentMorph : public RooAbsPdf {
 
 #if ROOT_VERSION_CODE>=ROOT_VERSION(5,34,15)
   void fixCache() { _cacheMgr.setClearOnRedirect(kFALSE) ; }
-  virtual CacheMode canNodeBeCached() const { return RooAbsArg::NotAdvised ; } ;
+  CacheMode canNodeBeCached() const override { return RooAbsArg::NotAdvised ; } ;
 #endif
 
 
@@ -336,9 +336,9 @@ class RooStarMomentMorph : public RooAbsPdf {
     CacheElem(RooAbsPdf& sumPdf, RooChangeTracker& tracker, const RooArgList& flist) : _sumPdf(&sumPdf), _tracker(&tracker), _fractionsCalculated(false) { 
       _frac.add(flist) ; 
     } ;
-    void operModeHook(RooAbsArg::OperMode) {};
-    virtual ~CacheElem() ; 
-    virtual RooArgList containedArgs(Action) ;
+    void operModeHook(RooAbsArg::OperMode) override {};
+    ~CacheElem() override ; 
+    RooArgList containedArgs(Action) override ;
     RooAbsPdf* _sumPdf ;
     RooChangeTracker* _tracker ; 
     RooArgList _frac ;
@@ -353,7 +353,7 @@ class RooStarMomentMorph : public RooAbsPdf {
 
   friend class CacheElem ; // Cache needs to be able to clear _norm pointer
 
-  Double_t evaluate() const ;
+  Double_t evaluate() const override ;
 
   void     initialize();
   CacheElem* getCache(const RooArgSet* nset) const ;
@@ -379,7 +379,7 @@ class RooStarMomentMorph : public RooAbsPdf {
 
   Bool_t _useHorizMorph;
 
-  ClassDef(RooStarMomentMorph,2) // Your description goes here...
+  ClassDefOverride(RooStarMomentMorph,2) // Your description goes here...
 };
 
 #endif

interface/BayesianFlatPrior.h

@@ -13,8 +13,8 @@
 class BayesianFlatPrior : public LimitAlgo {
 public:
   BayesianFlatPrior() ;
-  virtual bool run(RooWorkspace *w, RooStats::ModelConfig *mc_s, RooStats::ModelConfig *mc_b, RooAbsData &data, double &limit, double &limitErr, const double *hint);
-  virtual const std::string & name() const {
+  bool run(RooWorkspace *w, RooStats::ModelConfig *mc_s, RooStats::ModelConfig *mc_b, RooAbsData &data, double &limit, double &limitErr, const double *hint) override;
+  const std::string & name() const override {
     static const std::string name("BayesianSimple");
     return name;
   }

interface/BayesianToyMC.h

@@ -14,10 +14,10 @@ class RooArgSet;
 class BayesianToyMC : public LimitAlgo {
 public:
   BayesianToyMC() ;
-  virtual bool run(RooWorkspace *w, RooStats::ModelConfig *mc_s, RooStats::ModelConfig *mc_b, RooAbsData &data, double &limit, double &limitErr, const double *hint);
+  bool run(RooWorkspace *w, RooStats::ModelConfig *mc_s, RooStats::ModelConfig *mc_b, RooAbsData &data, double &limit, double &limitErr, const double *hint) override;
   virtual bool runBayesFactor(RooWorkspace *w, RooStats::ModelConfig *mc_s, RooStats::ModelConfig *mc_b, RooAbsData &data, double &limit, double &limitErr, const double *hint);
-  virtual void applyOptions(const boost::program_options::variables_map &vm) ;
-  virtual const std::string & name() const {
+  void applyOptions(const boost::program_options::variables_map &vm) override ;
+  const std::string & name() const override {
     static const std::string name("BayesianToyMC");
     return name;
   }

interface/BestFitSigmaTestStat.h

@@ -19,9 +19,9 @@ class BestFitSigmaTestStat : public RooStats::TestStatistic {
                 const RooArgSet *nuisances, 
                 const RooArgSet & params, int verbosity=0) ; 
 
-        virtual Double_t Evaluate(RooAbsData& data, RooArgSet& nullPOI) ;
+        Double_t Evaluate(RooAbsData& data, RooArgSet& nullPOI) override ;
 
-        virtual const TString GetVarName() const { return "mu-hat`"; }
+        const TString GetVarName() const override { return "mu-hat`"; }
 
         // Verbosity (default: 0)
         void setPrintLevel(Int_t level) { verbosity_ = level; }

interface/CMSExternalMorph.h

@@ -22,7 +22,7 @@ class CMSExternalMorph : public RooAbsReal {
         const std::vector<double>& edges
     );
     CMSExternalMorph(CMSExternalMorph const& other, const char* name = 0);
-    virtual ~CMSExternalMorph();
+    ~CMSExternalMorph() override;
 
     /* Batch accessor for CMSHistFunc / CMSHistSum, to be overriden by concrete
      * implementations. hasChanged() should indicate whether or not
@@ -36,10 +36,10 @@ class CMSExternalMorph : public RooAbsReal {
     RooRealProxy x_;
     std::vector<double> edges_;
 
-    double evaluate() const;
+    double evaluate() const override;
 
   private:
-    ClassDef(CMSExternalMorph, 1)
+    ClassDefOverride(CMSExternalMorph, 1)
 };
 
 #endif // CMSExternalMorph_h