diff -uNr llvm-project/libunwind/CMakeLists.txt llvm-project.mod/libunwind/CMakeLists.txt
--- llvm-project/libunwind/CMakeLists.txt	2021-11-27 10:22:36.327950400 +0800
+++ llvm-project.mod/libunwind/CMakeLists.txt	2021-11-27 12:36:37.310685400 +0800
@@ -212,6 +212,10 @@
 add_compile_flags_if_supported(-Werror=return-type)
 
 if (LIBUNWIND_ENABLE_CET)
+  if (NOT "libunwind" IN_LIST LLVM_ENABLE_RUNTIMES
+      AND "clang" IN_LIST LLVM_ENABLE_PROJECTS)
+    include_directories("${CMAKE_CURRENT_SOURCE_DIR}/../clang/lib/Headers")
+  endif()
   add_compile_flags_if_supported(-fcf-protection=full)
   add_compile_flags_if_supported(-mshstk)
   if (NOT LIBUNWIND_SUPPORTS_FCF_PROTECTION_EQ_FULL_FLAG)