diff --git a/llvm/cmake/modules/TableGen.cmake b/llvm/cmake/modules/TableGen.cmake
--- a/llvm/cmake/modules/TableGen.cmake
+++ b/llvm/cmake/modules/TableGen.cmake
@@ -89,6 +89,8 @@
   # ("${${project}_TABLEGEN_TARGET}" STREQUAL "${${project}_TABLEGEN_EXE}")
   # but lets us having smaller and cleaner code here.
   get_directory_property(tblgen_includes INCLUDE_DIRECTORIES)
+  # No support for generator-expressions in add_custom_command, so strip them
+  list(TRANSFORM tblgen_includes GENEX_STRIP)
   list(TRANSFORM tblgen_includes PREPEND -I)
 
   add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${ofn}