Index: streamexecutor/CMakeLists.txt
===================================================================
--- streamexecutor/CMakeLists.txt
+++ streamexecutor/CMakeLists.txt
@@ -26,17 +26,17 @@
     include_directories(${LLVM_INCLUDE_DIRS})
     add_definitions(${LLVM_DEFINITIONS})
 
-    # Get the LLVM cxxflags by using llvm-config.
-    #
-    # This is necessary to get -fno-rtti if LLVM is compiled that way.
+    # If LLVM does not have RTTI, don't use it here either.
     execute_process(
         COMMAND
         "${LLVM_BINARY_DIR}/bin/llvm-config"
-        --cxxflags
+        --has-rtti
         OUTPUT_VARIABLE
-        LLVM_CXXFLAGS
+        STREAM_EXECUTOR_LLVM_HAS_RTTI
         OUTPUT_STRIP_TRAILING_WHITESPACE)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${LLVM_CXXFLAGS}")
+    if (NOT STREAM_EXECUTOR_LLVM_HAS_RTTI)
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-rtti")
+    endif()
 
     set(LLVM_CMAKE_PATH "${LLVM_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm")
     list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_PATH}")