[analyzer] const-ify reference to bug type used in BugReporter

[NoQ]

clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h

98

& -> & :)

167

& -> & :)

170

& -> & :)

193

I guess this was left around accidentally.

clang/lib/StaticAnalyzer/Core/BugReporter.cpp

2721

& -> & :)

2839

& -> & :)

I mean i don't insist, just noticed :)

clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h

public:
   using visitor_iterator = VisitorList::iterator;
   using ExtraTextList = SmallVector<StringRef, 2>;
   using NoteList = SmallVector<std::shared_ptr<PathDiagnosticNotePiece>, 4>;
 
 protected:
   friend class BugReportEquivClass;
   friend class BugReporter;
 
-  BugType& BT;
+  const BugType& BT;
   const Decl *DeclWithIssue = nullptr;
   std::string ShortDescription;
   std::string Description;
   PathDiagnosticLocation Location;
   PathDiagnosticLocation UniqueingLocation;
   const Decl *UniqueingDecl;
 
   const ExplodedNode *ErrorNode = nullptr;
private:
   Symbols &getInterestingSymbols();
   Regions &getInterestingRegions();
 
   void lazyInitializeInterestingSets();
   void pushInterestingSymbolsAndRegions();
   void popInterestingSymbolsAndRegions();
 
 public:
-  BugReport(BugType& bt, StringRef desc, const ExplodedNode *errornode)
+  BugReport(const BugType& bt, StringRef desc, const ExplodedNode *errornode)
       : BT(bt), Description(desc), ErrorNode(errornode) {}
 
-  BugReport(BugType& bt, StringRef shortDesc, StringRef desc,
+  BugReport(const BugType& bt, StringRef shortDesc, StringRef desc,
             const ExplodedNode *errornode)
       : BT(bt), ShortDescription(shortDesc), Description(desc),
         ErrorNode(errornode) {}
 
-  BugReport(BugType &bt, StringRef desc, PathDiagnosticLocation l)
+  BugReport(const BugType &bt, StringRef desc, PathDiagnosticLocation l)
       : BT(bt), Description(desc), Location(l) {}
 
   /// Create a BugReport with a custom uniqueing location.
   ///
   /// The reports that have the same report location, description, bug type, and
   /// ranges are uniqued - only one of the equivalent reports will be presented
   /// to the user. This method allows to rest the location which should be used
   /// for uniquing reports. For example, memory leaks checker, could set this to
   /// the allocation site, rather then the location where the bug is reported.
   BugReport(BugType& bt, StringRef desc, const ExplodedNode *errornode,
             PathDiagnosticLocation LocationToUnique, const Decl *DeclToUnique)
       : BT(bt), Description(desc), UniqueingLocation(LocationToUnique),
         UniqueingDecl(DeclToUnique), ErrorNode(errornode) {}
 
   virtual ~BugReport();
 
   const BugType& getBugType() const { return BT; }
-  BugType& getBugType() { return BT; }
+  //BugType& getBugType() { return BT; }
 
   /// True when the report has an execution path associated with it.
   ///
   /// A report is said to be path-sensitive if it was thrown against a
   /// particular exploded node in the path-sensitive analysis graph.
   /// Path-sensitive reports have their intermediate path diagnostics
   /// auto-generated, perhaps with the help of checker-defined visitors,
   /// and may contain extra notes.
public:
   AnalyzerOptions &getAnalyzerOptions() { return D.getAnalyzerOptions(); }
 
   virtual std::unique_ptr<DiagnosticForConsumerMapTy>
   generatePathDiagnostics(ArrayRef<PathDiagnosticConsumer *> consumers,
                           ArrayRef<BugReport *> &bugReports) {
     return {};
   }
 
-  void Register(BugType *BT);
+  void Register(const BugType *BT);
 
   /// Add the given report to the set of reports tracked by BugReporter.
   ///
   /// The reports are usually generated by the checkers. Further, they are
   /// folded based on the profile value, which is done to coalesce similar
   /// reports.
   void emitReport(std::unique_ptr<BugReport> R);
 

clang/lib/StaticAnalyzer/Core/BugReporter.cpp

         addEdgeToPath(PD.getActivePath(), PrevLoc, L);
       }
     }
   }
 }
 
 static std::unique_ptr<PathDiagnostic>
 generateEmptyDiagnosticForReport(BugReport *R, SourceManager &SM) {
-  BugType &BT = R->getBugType();
+  const BugType &BT = R->getBugType();
   return llvm::make_unique<PathDiagnostic>(
       R->getBugType().getCheckName(), R->getDeclWithIssue(),
       R->getBugType().getName(), R->getDescription(),
       R->getShortDescription(/*Fallback=*/false), BT.getCategory(),
       R->getUniqueingLocation(), R->getUniqueingDecl(),
       findExecutedLines(SM, R->getErrorNode()));
 }
 

           PC->getGenerationScheme(), PDB, ErrorNode, *ReportInfo.second);
       (*Out)[PC] = std::move(PD);
     }
   }
 
   return Out;
 }
 
-void BugReporter::Register(BugType *BT) {
+void BugReporter::Register(const BugType *BT) {
   BugTypes = F.add(BugTypes, BT);
 }
 
 void BugReporter::emitReport(std::unique_ptr<BugReport> R) {
   if (const ExplodedNode *E = R->getErrorNode()) {
     // An error node must either be a sink or have a tag, otherwise
     // it could get reclaimed before the path diagnostic is created.
     assert((E->isSink() || E->getLocation().getTag()) &&

   if (!ValidSourceLoc)
     return;
 
   // Compute the bug report's hash to determine its equivalence class.
   llvm::FoldingSetNodeID ID;
   R->Profile(ID);
 
   // Lookup the equivance class.  If there isn't one, create it.
-  BugType& BT = R->getBugType();
+  const BugType& BT = R->getBugType();
   Register(&BT);
   void *InsertPos;
   BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos);
 
   if (!EQ) {
     EQ = new BugReportEquivClass(std::move(R));
     EQClasses.InsertNode(EQ, InsertPos);
     EQClassesVector.push_back(EQ);

   return true;
 }
 
 static BugReport *
 FindReportInEquivalenceClass(BugReportEquivClass& EQ,
                              SmallVectorImpl<BugReport*> &bugReports) {
   BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end();
   assert(I != E);
-  BugType& BT = I->getBugType();
+  const BugType& BT = I->getBugType();
 
   // If we don't need to suppress any of the nodes because they are
   // post-dominated by a sink, simply add all the nodes in the equivalence class
   // to 'Nodes'.  Any of the reports will serve as a "representative" report.
   if (!BT.isSuppressOnSink()) {
     BugReport *R = &*I;
     for (auto &I : EQ) {
       const ExplodedNode *N = I.getErrorNode();