Don't override VisitUnaryOperator in RMFPV.

``RMFPV::VisitUnaryOperator`` was written when ``ReverseModeVisitor`` didn't support pointers. Now, ``RMFPV::VisitUnaryOperator`` essentially replicates  ``RMV::VisitUnaryOperator``.

Author: PetroZarytskyi

include/clad/Differentiator/ReverseModeForwPassVisitor.h

@@ -37,7 +37,6 @@ class ReverseModeForwPassVisitor : public ReverseModeVisitor {
   StmtDiff VisitCompoundStmt(const clang::CompoundStmt* CS) override;
   StmtDiff VisitDeclRefExpr(const clang::DeclRefExpr* DRE) override;
   StmtDiff VisitReturnStmt(const clang::ReturnStmt* RS) override;
-  StmtDiff VisitUnaryOperator(const clang::UnaryOperator* UnOp) override;
 };
 } // namespace clad
 

include/clad/Differentiator/ReverseModeVisitor.h

@@ -15,6 +15,7 @@
 #include "clad/Differentiator/VisitorBase.h"
 
 #include "clang/AST/DeclCXX.h"
+#include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/RecursiveASTVisitor.h"
 #include "clang/AST/StmtVisitor.h"
@@ -383,7 +384,7 @@ namespace clad {
     StmtDiff VisitParenExpr(const clang::ParenExpr* PE);
     virtual StmtDiff VisitReturnStmt(const clang::ReturnStmt* RS);
     StmtDiff VisitStmt(const clang::Stmt* S);
-    virtual StmtDiff VisitUnaryOperator(const clang::UnaryOperator* UnOp);
+    StmtDiff VisitUnaryOperator(const clang::UnaryOperator* UnOp);
     StmtDiff
     VisitUnaryExprOrTypeTraitExpr(const clang::UnaryExprOrTypeTraitExpr* UE);
     StmtDiff VisitExprWithCleanups(const clang::ExprWithCleanups* EWC);

lib/Differentiator/ReverseModeForwPassVisitor.cpp

@@ -194,31 +194,4 @@ ReverseModeForwPassVisitor::VisitReturnStmt(const clang::ReturnStmt* RS) {
   Stmt* newRS = m_Sema.BuildReturnStmt(validLoc, returnInitList).get();
   return {newRS};
 }
-
-StmtDiff
-ReverseModeForwPassVisitor::VisitUnaryOperator(const UnaryOperator* UnOp) {
-  auto opCode = UnOp->getOpcode();
-  StmtDiff diff{};
-  // If it is a post-increment/decrement operator, its result is a reference
-  // and we should return it.
-  Expr* ResultRef = nullptr;
-  if (opCode == UnaryOperatorKind::UO_Deref) {
-    if (const auto* MD = dyn_cast<CXXMethodDecl>(m_DiffReq.Function)) {
-      if (MD->isInstance()) {
-        diff = Visit(UnOp->getSubExpr());
-        Expr* cloneE = BuildOp(UnaryOperatorKind::UO_Deref, diff.getExpr());
-        Expr* derivedE =
-            BuildOp(UnaryOperatorKind::UO_Deref, diff.getExpr_dx());
-        return {cloneE, derivedE};
-      }
-    }
-  } else if (opCode == UO_Plus)
-    diff = Visit(UnOp->getSubExpr(), dfdx());
-  else if (opCode == UO_Minus) {
-    auto d = BuildOp(UO_Minus, dfdx());
-    diff = Visit(UnOp->getSubExpr(), d);
-  }
-  Expr* op = BuildOp(opCode, diff.getExpr());
-  return StmtDiff(op, ResultRef);
-}
 } // namespace clad