cmake - CMake 检查是否调用了主项目

Question

我有这种项目目录设计：

Main:
    CMakeLists.txt
    subproject1:
         CMakeLists.txt   
    subproject2
         CMakeLists.txt   

如果 subproject1 cmake 被主项目调用，或者作为独立项目调用，我如何检查 subproject1/CMakeLists.txt 文件？

Answer 1

干得好：

if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
# We are building as stand-alone project
project(subproject1)
...
else()
# We are building as part of Main project
endif()