将目录添加到不带CMakeLists.txt的CMake项目中

我有以下项目结构：

• CMakeLists.txt（顶层）
• 包括
• 源文件
• 例子
• CMakeLists.txt
• example.cpp
• src
• CMakeLists.txt
• source.cpp

Top level CMakeLists.txt includes both src and examples using add_subdirectory. I want to do the same with include directory. I have no problem using the header files from include. What I want is to be able to see include directory in my IDE. Currently, QtCreator doesn't show include directory if I open the top level CMake file with it.

I know that I can add dummy CMakeLists.txt but that's a bit meh. Don't want to do this for code readers sanity sake.