diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -1117,14 +1117,7 @@
 
 function(get_compile_definitions)
   get_directory_property(top_dir_definitions DIRECTORY ${CMAKE_SOURCE_DIR} COMPILE_DEFINITIONS)
-  foreach(definition ${top_dir_definitions})
-    if(DEFINED result)
-      string(APPEND result " -D${definition}")
-    else()
-      set(result "-D${definition}")
-    endif()
-  endforeach()
-  set(LLVM_DEFINITIONS "${result}" PARENT_SCOPE)
+  set(LLVM_DEFINITIONS "${top_dir_definitions}" PARENT_SCOPE)
 endfunction()
 get_compile_definitions()