diff --git a/llvm/include/llvm/ExecutionEngine/Orc/Layer.h b/llvm/include/llvm/ExecutionEngine/Orc/Layer.h
--- a/llvm/include/llvm/ExecutionEngine/Orc/Layer.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/Layer.h
@@ -17,6 +17,7 @@
 #include "llvm/ExecutionEngine/Orc/Mangling.h"
 #include "llvm/ExecutionEngine/Orc/ThreadSafeModule.h"
 #include "llvm/IR/Module.h"
+#include "llvm/Support/Casting.h"
 #include "llvm/Support/MemoryBuffer.h"
 
 namespace llvm {
@@ -131,7 +132,15 @@
 /// Interface for Layers that accept object files.
 class ObjectLayer {
 public:
-  ObjectLayer(ExecutionSession &ES);
+  enum class Kind {
+    JITLink = 1,
+    RuntimeDyld = 2,
+    Transform = 3,
+  };
+
+  Kind getKind() const { return ObjectLayerKind; }
+
+  ObjectLayer(ExecutionSession &ES, Kind K);
   virtual ~ObjectLayer();
 
   /// Returns the execution session for this layer.
@@ -151,6 +160,7 @@
 
 private:
   ExecutionSession &ES;
+  const Kind ObjectLayerKind;
 };
 
 /// Materializes the given object file (represented by a MemoryBuffer
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h b/llvm/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h
--- a/llvm/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h
@@ -105,6 +105,10 @@
   /// Destruct an ObjectLinkingLayer.
   ~ObjectLinkingLayer();
 
+  static bool classof(const ObjectLayer *Layer) {
+    return Layer->getKind() == Kind::JITLink;
+  }
+
   /// Set an object buffer return function. By default object buffers are
   /// deleted once the JIT has linked them. If a return function is set then
   /// it will be called to transfer ownership of the buffer instead.
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/ObjectTransformLayer.h b/llvm/include/llvm/ExecutionEngine/Orc/ObjectTransformLayer.h
--- a/llvm/include/llvm/ExecutionEngine/Orc/ObjectTransformLayer.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/ObjectTransformLayer.h
@@ -31,6 +31,10 @@
   ObjectTransformLayer(ExecutionSession &ES, ObjectLayer &BaseLayer,
                        TransformFunction Transform = TransformFunction());
 
+  static bool classof(const ObjectLayer *Layer) {
+    return Layer->getKind() == Kind::Transform;
+  }
+
   void emit(std::unique_ptr<MaterializationResponsibility> R,
             std::unique_ptr<MemoryBuffer> O) override;
 
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h b/llvm/include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h
--- a/llvm/include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h
@@ -56,6 +56,10 @@
 
   ~RTDyldObjectLinkingLayer();
 
+  static bool classof(const ObjectLayer *Layer) {
+    return Layer->getKind() == Kind::RuntimeDyld;
+  }
+
   /// Emit the object.
   void emit(std::unique_ptr<MaterializationResponsibility> R,
             std::unique_ptr<MemoryBuffer> O) override;
diff --git a/llvm/lib/ExecutionEngine/Orc/Layer.cpp b/llvm/lib/ExecutionEngine/Orc/Layer.cpp
--- a/llvm/lib/ExecutionEngine/Orc/Layer.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/Layer.cpp
@@ -155,7 +155,8 @@
   }););
 }
 
-ObjectLayer::ObjectLayer(ExecutionSession &ES) : ES(ES) {}
+ObjectLayer::ObjectLayer(ExecutionSession &ES, Kind K)
+    : ES(ES), ObjectLayerKind(K) {}
 
 ObjectLayer::~ObjectLayer() {}
 
diff --git a/llvm/lib/ExecutionEngine/Orc/ObjectLinkingLayer.cpp b/llvm/lib/ExecutionEngine/Orc/ObjectLinkingLayer.cpp
--- a/llvm/lib/ExecutionEngine/Orc/ObjectLinkingLayer.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/ObjectLinkingLayer.cpp
@@ -461,13 +461,14 @@
 
 ObjectLinkingLayer::ObjectLinkingLayer(ExecutionSession &ES,
                                        JITLinkMemoryManager &MemMgr)
-    : ObjectLayer(ES), MemMgr(MemMgr) {
+    : ObjectLayer(ES, Kind::JITLink), MemMgr(MemMgr) {
   ES.registerResourceManager(*this);
 }
 
 ObjectLinkingLayer::ObjectLinkingLayer(
     ExecutionSession &ES, std::unique_ptr<JITLinkMemoryManager> MemMgr)
-    : ObjectLayer(ES), MemMgr(*MemMgr), MemMgrOwnership(std::move(MemMgr)) {
+    : ObjectLayer(ES, Kind::JITLink), MemMgr(*MemMgr),
+      MemMgrOwnership(std::move(MemMgr)) {
   ES.registerResourceManager(*this);
 }
 
diff --git a/llvm/lib/ExecutionEngine/Orc/ObjectTransformLayer.cpp b/llvm/lib/ExecutionEngine/Orc/ObjectTransformLayer.cpp
--- a/llvm/lib/ExecutionEngine/Orc/ObjectTransformLayer.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/ObjectTransformLayer.cpp
@@ -13,9 +13,10 @@
 namespace orc {
 
 ObjectTransformLayer::ObjectTransformLayer(ExecutionSession &ES,
-                                            ObjectLayer &BaseLayer,
-                                            TransformFunction Transform)
-    : ObjectLayer(ES), BaseLayer(BaseLayer), Transform(std::move(Transform)) {}
+                                           ObjectLayer &BaseLayer,
+                                           TransformFunction Transform)
+    : ObjectLayer(ES, Kind::Transform), BaseLayer(BaseLayer),
+      Transform(std::move(Transform)) {}
 
 void ObjectTransformLayer::emit(
     std::unique_ptr<MaterializationResponsibility> R,
diff --git a/llvm/lib/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.cpp b/llvm/lib/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.cpp
--- a/llvm/lib/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.cpp
@@ -77,7 +77,7 @@
 
 RTDyldObjectLinkingLayer::RTDyldObjectLinkingLayer(
     ExecutionSession &ES, GetMemoryManagerFunction GetMemoryManager)
-    : ObjectLayer(ES), GetMemoryManager(GetMemoryManager) {
+    : ObjectLayer(ES, Kind::RuntimeDyld), GetMemoryManager(GetMemoryManager) {
   ES.registerResourceManager(*this);
 }
 
diff --git a/llvm/tools/lli/lli.cpp b/llvm/tools/lli/lli.cpp
--- a/llvm/tools/lli/lli.cpp
+++ b/llvm/tools/lli/lli.cpp
@@ -881,10 +881,12 @@
 
   auto J = ExitOnErr(Builder.create());
 
-  if (TT->isOSBinFormatELF())
-    static_cast<llvm::orc::RTDyldObjectLinkingLayer &>(J->getObjLinkingLayer())
-        .registerJITEventListener(
-            *JITEventListener::createGDBRegistrationListener());
+  if (TT->isOSBinFormatELF()) {
+    if (auto *ObjLayer =
+            dyn_cast<orc::RTDyldObjectLinkingLayer>(&J->getObjLinkingLayer()))
+      ObjLayer->registerJITEventListener(
+          *JITEventListener::createGDBRegistrationListener());
+  }
 
   if (PerModuleLazy)
     J->setPartitionFunction(orc::CompileOnDemandLayer::compileWholeModule);