diff --git a/cmake/modules/LLVMProcessSources.cmake b/cmake/modules/LLVMProcessSources.cmake
index 2d88abfd752..ccc22a80274 100644
--- a/cmake/modules/LLVMProcessSources.cmake
+++ b/cmake/modules/LLVMProcessSources.cmake
@@ -82,7 +82,7 @@ endfunction(llvm_process_sources)
 
 function(llvm_check_source_file_list)
   set(listed ${ARGN})
-  file(GLOB globbed *.cpp)
+  file(GLOB globbed *.c *.cpp)
   foreach(g ${globbed})
     get_filename_component(fn ${g} NAME)
     list(FIND LLVM_OPTIONAL_SOURCES ${fn} idx)
@@ -90,7 +90,7 @@ function(llvm_check_source_file_list)
       list(FIND listed ${fn} idx)
       if( idx LESS 0 )
         message(SEND_ERROR "Found unknown source file ${g}
-Please update ${CMAKE_CURRENT_SOURCE_DIR}/CMakeLists.txt\n")
+Please update ${CMAKE_CURRENT_LIST_FILE}\n")
       endif()
     endif()
   endforeach()