[LKH] Add a new IRTransformLayer.

llvm-svn: 333129
diff --git a/llvm/lib/ExecutionEngine/Orc/IRTransformLayer.cpp b/llvm/lib/ExecutionEngine/Orc/IRTransformLayer.cpp
new file mode 100644
index 0000000..4dd3cfd
--- /dev/null
+++ b/llvm/lib/ExecutionEngine/Orc/IRTransformLayer.cpp
@@ -0,0 +1,34 @@
+//===-------------- IRTransformLayer.cpp - IR Transform Layer -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ExecutionEngine/Orc/IRTransformLayer.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+namespace llvm {
+namespace orc {
+
+IRTransformLayer2::IRTransformLayer2(ExecutionSession &ES,
+                                     IRLayer &BaseLayer,
+                                     TransformFunction Transform)
+    : IRLayer(ES), BaseLayer(BaseLayer), Transform(std::move(Transform)) {}
+
+void IRTransformLayer2::emit(MaterializationResponsibility R, VModuleKey K,
+                             std::unique_ptr<Module> M) {
+  assert(M && "Module must not be null");
+
+  if (auto TransformedMod = Transform(std::move(M)))
+    BaseLayer.emit(std::move(R), std::move(K), std::move(*TransformedMod));
+  else {
+    R.failMaterialization();
+    getExecutionSession().reportError(TransformedMod.takeError());
+  }
+}
+
+} // End namespace orc.
+} // End namespace llvm.