1 files changed, 31 insertions, 0 deletions
diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 3de4b5771a2..22d15be6a87 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -33,6 +33,37 @@
 #include <cstring>
 using namespace clang;
 
+const CXXRecordDecl *Expr::getMostDerivedClassDeclForType() const {
+  const Expr *E = this;
+
+  while (true) {
+    E = E->IgnoreParens();
+    if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
+      if (CE->getCastKind() == CK_DerivedToBase ||
+          CE->getCastKind() == CK_UncheckedDerivedToBase ||
+          CE->getCastKind() == CK_NoOp) {
+        E = CE->getSubExpr();
+        continue;
+      }
+    }
+
+    break;
+  }
+
+  QualType DerivedType = E->getType();
+  if (DerivedType->isDependentType())
+    return NULL;
+  if (const PointerType *PTy = DerivedType->getAs<PointerType>())
+    DerivedType = PTy->getPointeeType();
+
+  const RecordType *Ty = DerivedType->castAs<RecordType>();
+  if (!Ty)
+    return NULL;
+
+  Decl *D = Ty->getDecl();
+  return cast<CXXRecordDecl>(D);
+}
+
 /// isKnownToHaveBooleanValue - Return true if this is an integer expression
 /// that is known to return 0 or 1.  This happens for _Bool/bool expressions
 /// but also int expressions which are produced by things like comparisons in