Remove the enableTBR state from reverse mode visitor. NFC

Partially addresses #721.

include/clad/Differentiator/ReverseModeVisitor.h

@@ -63,7 +63,6 @@ namespace clad {
     std::vector<Stmts> m_LoopBlock;
     unsigned outputArrayCursor = 0;
     unsigned numParams = 0;
-    bool enableTBR = false;
     // FIXME: Should we make this an object instead of a pointer?
     // Downside of making it an object: We will need to include
     // 'MultiplexExternalRMVSource.h' file

lib/Differentiator/ReverseModeVisitor.cpp

@@ -292,10 +292,6 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
       outputArrayStr = m_DiffReq->getParamDecl(lastArgN)->getNameAsString();
     }
 
-    // Check if DiffRequest asks for TBR analysis to be enabled
-    if (request.EnableTBRAnalysis)
-      enableTBR = true;
-
     auto derivativeBaseName = request.BaseFunctionName;
     std::string gradientName = derivativeBaseName + funcPostfix();
     // To be consistent with older tests, nothing is appended to 'f_grad' if
@@ -475,10 +471,8 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
   DerivativeAndOverload
   ReverseModeVisitor::DerivePullback(const clang::FunctionDecl* FD,
                                      const DiffRequest& request) {
-    if (request.EnableTBRAnalysis)
-      enableTBR = true;
-    TBRAnalyzer analyzer(m_Context);
-    if (enableTBR) {
+    if (request.EnableTBRAnalysis) {
+      TBRAnalyzer analyzer(m_Context);
       analyzer.Analyze(FD);
       m_ToBeRecorded = analyzer.getResult();
     }
@@ -602,8 +596,8 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
   }
 
   void ReverseModeVisitor::DifferentiateWithClad() {
-    TBRAnalyzer analyzer(m_Context);
-    if (enableTBR) {
+    if (m_DiffReq.EnableTBRAnalysis) {
+      TBRAnalyzer analyzer(m_Context);
       analyzer.Analyze(m_DiffReq.Function);
       m_ToBeRecorded = analyzer.getResult();
     }
@@ -1695,7 +1689,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
         pullbackRequest.Mode = DiffMode::experimental_pullback;
         // Silence diag outputs in nested derivation process.
         pullbackRequest.VerboseDiags = false;
-        pullbackRequest.EnableTBRAnalysis = enableTBR;
+        pullbackRequest.EnableTBRAnalysis = m_DiffReq.EnableTBRAnalysis;
         bool isaMethod = isa<CXXMethodDecl>(FD);
         for (size_t i = 0, e = FD->getNumParams(); i < e; ++i)
           if (DerivedCallOutputArgs[i + isaMethod])
@@ -2943,7 +2937,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     if (isa<DeclRefExpr>(B) || isa<ArraySubscriptExpr>(B) ||
         isa<MemberExpr>(B)) {
       // If TBR analysis is off, assume E is useful to store.
-      if (!enableTBR)
+      if (!m_DiffReq.EnableTBRAnalysis)
         return true;
       // FIXME: currently, we allow all pointer operations to be stored.
       // This is not correct, but we need to implement a more advanced analysis