区分PROJECT_SOURCE_DIR, CMAKE_SOURCE_DIR,CMAKE_CURRENT_SOURCE_DIR

目录

示例工程

PROJECT_SOURCE_DIR的行为

CMAKE_SOURCE_DIR的行为

CMAKE_CURRENT_SOURCE_DIR

---

示例工程

根目录

        |-----CMakeLists.txt

        |-----sub1

                |--------CMakeLists.txt

        |-----sub2

                |--------CMakeLists.txt

根目录下的CMakeList.txt:

project(main)message("main CMAKE_SOURCE_DIR = ${CMAKE_SOURCE_DIR}")
message("main CMAKE_CURRENT_SOURCE_DIR = ${CMAKE_CURRENT_SOURCE_DIR}")
message("main PROJECT_SOURCE_DIR = ${PROJECT_SOURCE_DIR}")add_subdirectory(sub1)
add_subdirectory(sub2)

sub1目录下的CMakeLists.txt

project(sub1)message("sub1 CMAKE_SOURCE_DIR = ${CMAKE_SOURCE_DIR}")
message("sub1 CMAKE_CURRENT_SOURCE_DIR = ${CMAKE_CURRENT_SOURCE_DIR}")
message("sub1 PROJECT_SOURCE_DIR = ${PROJECT_SOURCE_DIR}")

sub2目录下的CMakeLists.txt

message("sub2 CMAKE_SOURCE_DIR = ${CMAKE_SOURCE_DIR}")
message("sub2 CMAKE_CURRENT_SOURCE_DIR = ${CMAKE_CURRENT_SOURCE_DIR}")
message("sub2 PROJECT_SOURCE_DIR = ${PROJECT_SOURCE_DIR}")

 sub1与sub2的CMakeLists的区别仅仅在于开头有没有使用project命令

PROJECT_SOURCE_DIR的行为

在根目录下运行cmake .

PROJECT_SOURCE_DIR的取值受两个因素影响：1所在目录 ，2所在的CMakeLists.txt有没有调用project命令

从打印结果可以看出来：

1 根目录下的CMakeLists.txt的PROJECT_SOURCE_DIR等于根目录路径；

2 如果不在根目录下，而是在子目录下，则：

2.1 如果子目录的CMakeLists.txt使用了project命令，则PROJECT_SOURCE_DIR等于当前子目录路径；

2.2 如果子目录的CMakeLists.txt没有使用project命令，则PROJECT_SOURCE_DIR等于上一层CMakeLists.txt的PROJECT_SOURCE_DIR

CMAKE_SOURCE_DIR的行为

不论CMakeLists在根目录还是子目录，也不论CMakeLists.txt里面有没有调用project函数，CMAKE_SOURCE_DIR都等于根目录路径

CMAKE_CURRENT_SOURCE_DIR

不论CMakeLists在根目录还是子目录，也不论CMakeLists.txt里面有没有调用project函数，CMAKE_CURRENT_SOURCE_DIR都等于当前目录路径