[hist] add bounds and overflow checking

See https://root-forum.cern.ch/t/tprincipal-fails-for-a-very-large-number-of-entries/58795
root-project · Apr 2, 2024 · 8039d84 · 8039d84
1 parent 38ed8e8
commit 8039d84
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Showing 2 changed files with 18 additions and 6 deletions.
diff --git a/hist/hist/inc/TPrincipal.h b/hist/hist/inc/TPrincipal.h
@@ -51,7 +51,7 @@ class TPrincipal : public TNamed {
 public:
    TPrincipal();
    ~TPrincipal() override;
-   TPrincipal(Int_t nVariables, Option_t *opt="ND");
+   TPrincipal(Long64_t nVariables, Option_t *opt="ND");
 
    virtual void       AddRow(const Double_t *x);
    void       Browse(TBrowser *b) override;
@@ -62,7 +62,7 @@ class TPrincipal : public TNamed {
    const TMatrixD    *GetEigenVectors() const     {return &fEigenVectors;}
    TList             *GetHistograms() const {return fHistograms;}
    const TVectorD    *GetMeanValues() const       {return &fMeanValues;}
-   const Double_t    *GetRow(Int_t row);
+   const Double_t    *GetRow(Long64_t row);
    const TVectorD    *GetSigmas() const           {return &fSigmas;}
    const TVectorD    *GetUserData() const         {return &fUserData;}
    Bool_t             IsFolder() const override { return kTRUE;}

diff --git a/hist/hist/src/TPrincipal.cxx b/hist/hist/src/TPrincipal.cxx
@@ -250,7 +250,7 @@ TPrincipal::TPrincipal()
 ///
 /// The created object is  named "principal" by default.
 
-TPrincipal::TPrincipal(Int_t nVariables, Option_t *opt)
+TPrincipal::TPrincipal(Long64_t nVariables, Option_t *opt)
   : fMeanValues(nVariables),
     fSigmas(nVariables),
     fCovarianceMatrix(nVariables,nVariables),
@@ -260,7 +260,11 @@ TPrincipal::TPrincipal(Int_t nVariables, Option_t *opt)
     fStoreData(kFALSE)
 {
    if (nVariables <= 1) {
-      Error("TPrincipal", "You can't be serious - nVariables == 1!!!");
+      Error("TPrincipal", "You can't be serious - nVariables <= 1!!!");
+      return;
+   }
+   if (nVariables > std::numeric_limits<Int_t>::max()) {
+      Error("TPrincipal", "`nVariables` input parameter %lld is larger than the allowed maximum %d", nVariables, std::numeric_limits<Int_t>::max());
       return;
    }
 
@@ -411,6 +415,10 @@ void TPrincipal::AddRow(const Double_t *p)
 {
    if (!p)
       return;
+   if (fNumberOfDataPoints == std::numeric_limits<Int_t>::max()) {
+      Error("AddRow", "`fNumberOfDataPoints` has reached its allowed maximum %d, cannot add new row.", fNumberOfDataPoints);
+      return;
+   }
 
    // Increment the data point counter
    Int_t i,j;
@@ -510,15 +518,19 @@ void TPrincipal::Clear(Option_t *opt)
 /// It's up to the user to delete the returned array.
 /// Row 0 is the first row;
 
-const Double_t *TPrincipal::GetRow(Int_t row)
+const Double_t *TPrincipal::GetRow(Long64_t row)
 {
    if (row >= fNumberOfDataPoints)
       return nullptr;
 
    if (!fStoreData)
       return nullptr;
 
-   Int_t index   = row  * fNumberOfVariables;
+   Long64_t index   = row  * fNumberOfVariables;
+   if (index > std::numeric_limits<Int_t>::max()) {
+      Error("GetRow", "Input parameter `row` %lld x fNumberOfVariables %d goes into overflow (%lld>%d), returning nullptr.", row, fNumberOfVariables, index,  std::numeric_limits<Int_t>::max());
+      return nullptr;
+   }
    return &fUserData(index);
 }