Remove excessive FD and request parameters from DeriveVectorMode

include/clad/Differentiator/VectorForwardModeVisitor.h

@@ -30,13 +30,10 @@ class VectorForwardModeVisitor : public BaseForwardModeVisitor {
   ///\brief Produces the first derivative of a given function with
   /// respect to multiple parameters.
   ///
-  ///\param[in] FD - the function that will be differentiated.
-  ///
   ///\returns The differentiated and potentially created enclosing
   /// context.
   ///
-  DerivativeAndOverload DeriveVectorMode(const clang::FunctionDecl* FD,
-                                         const DiffRequest& request);
+  DerivativeAndOverload DeriveVectorMode();
 
   /// Builds an overload for the vector mode function that has derived params
   /// for all the arguments of the requested function and it calls the original

lib/Differentiator/DerivativeBuilder.cpp

@@ -408,7 +408,7 @@ static void registerDerivative(FunctionDecl* derivedFD, Sema& semaRef) {
       result = V.DerivePushforward();
     } else if (request.Mode == DiffMode::vector_forward_mode) {
       VectorForwardModeVisitor V(*this, request);
-      result = V.DeriveVectorMode(FD, request);
+      result = V.DeriveVectorMode();
     } else if (request.Mode == DiffMode::experimental_vector_pushforward) {
       VectorPushForwardModeVisitor V(*this, request);
       result = V.DerivePushforward();

lib/Differentiator/VectorForwardModeVisitor.cpp

@@ -53,20 +53,16 @@ void VectorForwardModeVisitor::SetIndependentVarsExpr(Expr* IndVarCountExpr) {
   m_IndVarCountExpr = IndVarCountExpr;
 }
 
-DerivativeAndOverload
-VectorForwardModeVisitor::DeriveVectorMode(const FunctionDecl* FD,
-                                           const DiffRequest& request) {
-  assert(m_DiffReq == request);
+DerivativeAndOverload VectorForwardModeVisitor::DeriveVectorMode() {
+  const FunctionDecl* FD = m_DiffReq.Function;
   assert(m_DiffReq.Mode == DiffMode::vector_forward_mode);
 
   DiffParams args{};
-  DiffInputVarsInfo DVI;
-  DVI = request.DVI;
-  for (auto dParam : DVI)
+  for (const auto& dParam : m_DiffReq.DVI)
     args.push_back(dParam.param);
 
   // Generate name for the derivative function.
-  std::string derivedFnName = request.BaseFunctionName + "_dvec";
+  std::string derivedFnName = m_DiffReq.BaseFunctionName + "_dvec";
   if (args.size() != FD->getNumParams()) {
     for (auto arg : args) {
       auto it = std::find(FD->param_begin(), FD->param_end(), arg);