cmake_BINARY_DIR和CMAKE_CURRENT_SOURCE_DIR和CMAKE_SOURCE_DIR的区别

• CMAKE_CURRENT_SOURCE_DIR：当前正在处理的源目录的路径.
• CMAKE_SOURCE_DIR： 最外层CMakeLists.txt所在目录

最外层CMakeLists.txt

cmake_minimum_required(VERSION 3.16)
project(matser)

set(CMAKE_CXX_STANDARD 14)

message("matser_CMAKE_BINARY_DIR:     " ${CMAKE_BINARY_DIR} )
message("matser_CMAKE_SOURCE_DIR:     " ${CMAKE_SOURCE_DIR} )

if (${CMAKE_BINARY_DIR} STREQUAL ${CMAKE_SOURCE_DIR})
    message(FATAL_ERROR "Please into another dir to build!")
endif()

add_subdirectory(lib_c oceanstar)
add_subdirectory(lib_cpp oceanstar_cpp)

add_executable(matser main.cpp)

lib_c和lic_cpp的CMakeLists.txt：

cmake_minimum_required(VERSION 2.8)

message("c_CMAKE_BINARY_DIR:          " ${CMAKE_BINARY_DIR} )
message("c_CMAKE_CURRENT_SOURCE_DIR:  " ${CMAKE_CURRENT_SOURCE_DIR} )
message("c_CMAKE_SOURCE_DIR:          " ${CMAKE_SOURCE_DIR} )

if (${CMAKE_BINARY_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
    message(FATAL_ERROR "Please into another dir to build!")
endif()

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