Harmonize Derive and DerivePushforward

lib/Differentiator/BaseForwardModeVisitor.cpp

@@ -404,12 +404,6 @@ DerivativeAndOverload BaseForwardModeVisitor::DerivePushforward() {
          "Doesn't support recursive diff. Use DiffPlan.");
   m_DerivativeInFlight = true;
 
-  auto originalFnEffectiveName =
-      utils::ComputeEffectiveFnName(m_DiffReq.Function);
-
-  IdentifierInfo* derivedFnII = &m_Context.Idents.get(
-      originalFnEffectiveName + GetPushForwardFunctionSuffix());
-  DeclarationNameInfo derivedFnName(derivedFnII, m_DiffReq->getLocation());
   llvm::SmallVector<QualType, 16> paramTypes;
   llvm::SmallVector<QualType, 16> derivedParamTypes;
 
@@ -446,9 +440,15 @@ DerivativeAndOverload BaseForwardModeVisitor::DerivePushforward() {
   auto* DC = const_cast<DeclContext*>(m_DiffReq->getDeclContext());
   m_Sema.CurContext = DC;
 
-  SourceLocation loc{m_DiffReq->getLocation()};
-  DeclWithContext cloneFunctionResult = m_Builder.cloneFunction(
-      m_DiffReq.Function, *this, DC, loc, derivedFnName, derivedFnType);
+  auto originalFnEffectiveName = utils::ComputeEffectiveFnName(FD);
+
+  IdentifierInfo* derivedFnII = &m_Context.Idents.get(
+      originalFnEffectiveName + GetPushForwardFunctionSuffix());
+  SourceLocation loc{FD->getLocation()};
+  DeclarationNameInfo derivedFnName(derivedFnII, loc);
+
+  DeclWithContext cloneFunctionResult =
+      m_Builder.cloneFunction(FD, *this, DC, loc, derivedFnName, derivedFnType);
   m_Derivative = cloneFunctionResult.first;
 
   llvm::SmallVector<ParmVarDecl*, 16> params;
@@ -518,7 +518,6 @@ DerivativeAndOverload BaseForwardModeVisitor::DerivePushforward() {
 
     Stmt* derivativeBody = endBlock();
     m_Derivative->setBody(derivativeBody);
-
     endScope(); // Function body scope
 
     // Size >= current derivative order means that there exists a declaration