Index: cmake/modules/LLVMProcessSources.cmake
===================================================================
--- cmake/modules/LLVMProcessSources.cmake
+++ cmake/modules/LLVMProcessSources.cmake
@@ -28,26 +28,39 @@
   endif()
 endmacro(add_td_sources)
 
+function(add_header_files_for_glob hdrs_out glob)
+  file(GLOB hds ${glob})
+  set(${hdrs_out} ${hds} PARENT_SCOPE)
+endfunction(add_header_files_for_glob)
 
-macro(add_header_files srcs)
-  file(GLOB hds *.h)
-  if( hds )
-    set_source_files_properties(${hds} PROPERTIES HEADER_FILE_ONLY ON)
-    list(APPEND ${srcs} ${hds})
-  endif()
-endmacro(add_header_files)
+function(find_all_header_files hdrs_out additional_headerdirs)
+  add_header_files_for_glob(hds *.h)
+  list(APPEND all_headers ${hds})
+
+  foreach(additional_dir ${additional_headerdirs})
+    add_header_files_for_glob(hds "${additional_dir}/*.h")
+    list(APPEND all_headers ${hds})
+    add_header_files_for_glob(hds "${additional_dir}/*.inc")
+    list(APPEND all_headers ${hds})
+  endforeach(additional_dir)
+
+  set( ${hdrs_out} ${all_headers} PARENT_SCOPE )
+endfunction(find_all_header_files)
 
 
 function(llvm_process_sources OUT_VAR)
-  cmake_parse_arguments(ARG "" "" "ADDITIONAL_HEADERS" ${ARGN})
+  cmake_parse_arguments(ARG "" "" "ADDITIONAL_HEADERS;ADDITIONAL_HEADER_DIRS" ${ARGN})
   set(sources ${ARG_UNPARSED_ARGUMENTS})
   llvm_check_source_file_list( ${sources} )
   if( MSVC_IDE OR XCODE )
     # This adds .td and .h files to the Visual Studio solution:
     add_td_sources(sources)
-    add_header_files(sources)
+    find_all_header_files(hdrs "${ARG_ADDITIONAL_HEADER_DIRS}")
+    if (hdrs)
+      set_source_files_properties(${hdrs} PROPERTIES HEADER_FILE_ONLY ON)
+    endif()
     set_source_files_properties(${ARG_ADDITIONAL_HEADERS} PROPERTIES HEADER_FILE_ONLY ON)
-    list(APPEND sources ${ARG_ADDITIONAL_HEADERS})
+    list(APPEND sources ${ARG_ADDITIONAL_HEADERS} ${hdrs})
   endif()
 
   set( ${OUT_VAR} ${sources} PARENT_SCOPE )
Index: lib/Support/CMakeLists.txt
===================================================================
--- lib/Support/CMakeLists.txt
+++ lib/Support/CMakeLists.txt
@@ -121,30 +121,9 @@
   Valgrind.cpp
   Watchdog.cpp
 
-  ADDITIONAL_HEADERS
-  Unix/Host.inc
-  Unix/Memory.inc
-  Unix/Mutex.inc
-  Unix/Path.inc
-  Unix/Process.inc
-  Unix/Program.inc
-  Unix/RWMutex.inc
-  Unix/Signals.inc
-  Unix/ThreadLocal.inc
-  Unix/TimeValue.inc
-  Unix/Watchdog.inc
-  Windows/DynamicLibrary.inc
-  Windows/Host.inc
-  Windows/Memory.inc
-  Windows/Mutex.inc
-  Windows/Path.inc
-  Windows/Process.inc
-  Windows/Program.inc
-  Windows/RWMutex.inc
-  Windows/Signals.inc
-  Windows/ThreadLocal.inc
-  Windows/TimeValue.inc
-  Windows/Watchdog.inc
+  ADDITIONAL_HEADER_DIRS
+  Unix
+  Windows
 
   LINK_LIBS ${system_libs}
   )