From 4cb2d286843487680997e17a23b0e565f43f0b0a Mon Sep 17 00:00:00 2001
From: "petro.zarytskyi" <petro.zarytskyi@gmail.com>
Date: Wed, 21 Aug 2024 18:13:58 +0300
Subject: [PATCH] Save VD type in a variable in DifferentiateVarDecl

---
 lib/Differentiator/ReverseModeVisitor.cpp | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/lib/Differentiator/ReverseModeVisitor.cpp b/lib/Differentiator/ReverseModeVisitor.cpp
index aeb7a49ee..478db7c19 100644
--- a/lib/Differentiator/ReverseModeVisitor.cpp
+++ b/lib/Differentiator/ReverseModeVisitor.cpp
@@ -2719,29 +2719,30 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
         m_DiffReq.Mode != DiffMode::reverse_mode_forward_pass && !keepLocal;
     QualType VDCloneType;
     QualType VDDerivedType;
+    QualType VDType = VD->getType();
     // If the cloned declaration is moved to the function global scope,
     // change its type for the corresponding adjoint type.
     if (promoteToFnScope) {
-      VDDerivedType = ComputeAdjointType(CloneType(VD->getType()));
+      VDDerivedType = ComputeAdjointType(CloneType(VDType));
       VDCloneType = VDDerivedType;
       if (isa<ArrayType>(VDCloneType) && !isa<IncompleteArrayType>(VDCloneType))
         VDCloneType =
             GetCladArrayOfType(m_Context.getBaseElementType(VDCloneType));
     } else {
-      VDCloneType = CloneType(VD->getType());
+      VDCloneType = CloneType(VDType);
       VDDerivedType = getNonConstType(VDCloneType, m_Context, m_Sema);
     }
 
-    bool isRefType = VD->getType()->isLValueReferenceType();
+    bool isRefType = VDType->isLValueReferenceType();
     VarDecl* VDDerived = nullptr;
-    bool isPointerType = VD->getType()->isPointerType();
+    bool isPointerType = VDType->isPointerType();
     bool isInitializedByNewExpr = false;
     bool initializeDerivedVar = true;
 
     // We need to replace std::initializer_list with clad::array because the
     // former is temporary by design and it's not possible to create modifiable
     // adjoints.
-    if (m_Sema.isStdInitializerList(utils::GetValueType(VD->getType()),
+    if (m_Sema.isStdInitializerList(utils::GetValueType(VDType),
                                     /*Element=*/nullptr)) {
       if (const Expr* init = VD->getInit()) {
         if (const auto* CXXILE =
@@ -2776,7 +2777,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
 
     // VDDerivedInit now serves two purposes -- as the initial derivative value
     // or the size of the derivative array -- depending on the primal type.
-    if (const auto* AT = dyn_cast<ArrayType>(VD->getType())) {
+    if (const auto* AT = dyn_cast<ArrayType>(VDType)) {
       if (!isa<VariableArrayType>(AT)) {
         Expr* zero =
             ConstantFolder::synthesizeLiteral(m_Context.IntTy, m_Context, 0);
@@ -2801,7 +2802,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
       // value is set to 0.
       // Otherwise, for non-reference types, the initial value is set to 0.
       if (!VDDerivedInit)
-        VDDerivedInit = getZeroInit(VD->getType());
+        VDDerivedInit = getZeroInit(VDType);
 
       // `specialThisDiffCase` is only required for correctly differentiating
       // the following code:
@@ -2822,7 +2823,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
         initDiff = Visit(VD->getInit());
         if (!initDiff.getForwSweepExpr_dx()) {
           VDDerivedType =
-              ComputeAdjointType(VD->getType().getNonReferenceType());
+              ComputeAdjointType(VDType.getNonReferenceType());
           isRefType = false;
         }
         if (promoteToFnScope || !isRefType)
@@ -2855,7 +2856,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
         // If the pointer is const and derived expression is not available, then
         // we should not create a derived variable for it. This will be useful
         // for reducing number of differentiation variables in pullbacks.
-        bool constPointer = VD->getType()->getPointeeType().isConstQualified();
+        bool constPointer = VDType->getPointeeType().isConstQualified();
         if (constPointer && !isInitializedByNewExpr && !initDiff.getExpr_dx())
           initializeDerivedVar = false;
         else {
@@ -2863,7 +2864,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
           // If it's a pointer to a constant type, then remove the constness.
           if (constPointer) {
             // first extract the pointee type
-            auto pointeeType = VD->getType()->getPointeeType();
+            auto pointeeType = VDType->getPointeeType();
             // then remove the constness
             pointeeType.removeLocalConst();
             // then create a new pointer type with the new pointee type
@@ -3003,7 +3004,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     //   _d_y
     // }
     if ((VD->getDeclName() != VDClone->getDeclName() ||
-         VD->getType() != VDClone->getType()))
+         VDType != VDClone->getType()))
       m_DeclReplacements[VD] = VDClone;
 
     return DeclDiff<VarDecl>(VDClone, VDDerived);