1 files changed, 26 insertions, 2 deletions
diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 9cf9e86c4f4..53ab5cfd58b 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -35,9 +35,33 @@
 #include <cstring>
 using namespace clang;
 
-const CXXRecordDecl *Expr::getBestDynamicClassType() const {
-  const Expr *E = ignoreParenBaseCasts();
+const Expr *Expr::getBestDynamicClassTypeExpr() const {
+  const Expr *E = this;
+  while (true) {
+    E = E->ignoreParenBaseCasts();
+
+    // Follow the RHS of a comma operator.
+    if (auto *BO = dyn_cast<BinaryOperator>(E)) {
+      if (BO->getOpcode() == BO_Comma) {
+        E = BO->getRHS();
+        continue;
+      }
+    }
 
+    // Step into initializer for materialized temporaries.
+    if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E)) {
+      E = MTE->GetTemporaryExpr();
+      continue;
+    }
+
+    break;
+  }
+
+  return E;
+}
+
+const CXXRecordDecl *Expr::getBestDynamicClassType() const {
+  const Expr *E = getBestDynamicClassTypeExpr();
   QualType DerivedType = E->getType();
   if (const PointerType *PTy = DerivedType->getAs<PointerType>())
     DerivedType = PTy->getPointeeType();