From c3df195bed9dd74e3531fe545f2877f5f385c960 Mon Sep 17 00:00:00 2001
From: Mihail Mihov <mihovmihailp+github@gmail.com>
Date: Wed, 17 Jul 2024 15:23:41 +0300
Subject: [PATCH] Fix temporary expressions in reverse mode

fixes #917
---
 lib/Differentiator/ReverseModeVisitor.cpp | 35 +++++++++++++++++------
 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/lib/Differentiator/ReverseModeVisitor.cpp b/lib/Differentiator/ReverseModeVisitor.cpp
index 6394ee9dd..bfa9505b1 100644
--- a/lib/Differentiator/ReverseModeVisitor.cpp
+++ b/lib/Differentiator/ReverseModeVisitor.cpp
@@ -1369,6 +1369,8 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
       return StmtDiff(Clone(CE));
     }
 
+    auto* CEModified = dyn_cast<CallExpr>(Clone(CE));
+
     auto NArgs = FD->getNumParams();
     // If the function has no args and is not a member function call then we
     // assume that it is not related to independent variables and does not
@@ -1618,8 +1620,10 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
             baseOriginalE = OCE->getArg(0);
 
           baseDiff = Visit(baseOriginalE);
-          Expr* baseDiffStore = GlobalStoreAndRef(baseDiff.getExpr());
-          baseDiff.updateStmt(baseDiffStore);
+
+          if (auto* ME = dyn_cast<MemberExpr>(CEModified->getCallee()))
+            ME->setBase(baseDiff.getExpr());
+
           Expr* baseDerivative = baseDiff.getExpr_dx();
           if (!baseDerivative->getType()->isPointerType())
             baseDerivative =
@@ -1878,13 +1882,13 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
           utils::BuildMemberExpr(m_Sema, getCurrentScope(), callRes, "adjoint");
       return StmtDiff(resValue, nullptr, resAdjoint);
     } // Recreate the original call expression.
+
     call = m_Sema
-               .ActOnCallExpr(getCurrentScope(), Clone(CE->getCallee()), Loc,
+               .ActOnCallExpr(getCurrentScope(), CEModified->getCallee(), Loc,
                               CallArgs, Loc)
                .get();
-    return StmtDiff(call);
 
-    return {};
+    return StmtDiff(call);
   }
 
   Expr* ReverseModeVisitor::GetMultiArgCentralDiffCall(
@@ -3747,8 +3751,21 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
       const clang::MaterializeTemporaryExpr* MTE) {
     // `MaterializeTemporaryExpr` node will be created automatically if it is
     // required by `ActOn`/`Build` Sema functions.
-    StmtDiff MTEDiff = Visit(clad_compat::GetSubExpr(MTE), dfdx());
-    return MTEDiff;
+    if(dfdx()) {
+	StmtDiff MTEDiff = Visit(clad_compat::GetSubExpr(MTE), dfdx());
+	return MTEDiff;
+    }
+
+    Expr* MTEStore =
+        GlobalStoreAndRef(Clone(clad_compat::GetSubExpr(MTE)), "_t",
+                          /*force=*/true);
+
+    auto* MTEStoreDRE = dyn_cast<DeclRefExpr>(MTEStore);
+    DeclDiff<VarDecl> MTEDerived =
+        DifferentiateVarDecl(dyn_cast<VarDecl>(MTEStoreDRE->getDecl()));
+    addToCurrentBlock(BuildDeclStmt(MTEDerived.getDecl_dx()));
+
+    return StmtDiff{MTEStore, BuildDeclRef(MTEDerived.getDecl_dx())};
   }
 
   StmtDiff ReverseModeVisitor::VisitSubstNonTypeTemplateParmExpr(
@@ -3928,8 +3945,10 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     if (m_DiffReq.Mode == DiffMode::experimental_pullback &&
         !m_DiffReq->getReturnType()->isVoidType()) {
       IdentifierInfo* pullbackParamII = CreateUniqueIdentifier("_d_y");
+      /*QualType pullbackType =*/
+      /*    derivativeFnType->getParamType(m_DiffReq->getNumParams());*/
       QualType pullbackType =
-          derivativeFnType->getParamType(m_DiffReq->getNumParams());
+	    m_Context.DoubleTy;
       ParmVarDecl* pullbackPVD = utils::BuildParmVarDecl(
           m_Sema, m_Derivative, pullbackParamII, pullbackType);
       paramDerivatives.insert(paramDerivatives.begin(), pullbackPVD);