CMAKE_CURRENT_SOURCE_DIR和CMAKE_SOURCE_DIR变量之间的区别？

https://qa.1r1g.com/sf/ask/3723663051/

 

 

CMAKE_SOURCE_DIR是cmake最初被调用的位置，CMAKE_CURRENT_SOURCE_DIR也是cmake当前正在工作的位置。例如，如果使用add_subdirectory命令将依赖项包含到项目中，则依赖项将具有自己的依赖项，CMAKE_CURRENT_SOURCE_DIR但CMAKE_SOURCE_DIR将保持不变。

展开一些程序员花花公子的评论，想象一下您在项目的不同目录中具有以下三个CMakeFiles

CMakeLists.txt

cmake_minimum_required(VERSION 3.12)

message("root dir CMAKE_SOURCE_DIR = ${CMAKE_SOURCE_DIR}")
message("root dir CMAKE_CURRENT_SOURCE_DIR = ${CMAKE_CURRENT_SOURCE_DIR}")

add_subdirectory(sub1)
add_subdirectory(sub2)

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sub1 / CMakeLists.txt

message("sub1 dir CMAKE_SOURCE_DIR = ${CMAKE_SOURCE_DIR}")
message("sub1 dir CMAKE_CURRENT_SOURCE_DIR = ${CMAKE_CURRENT_SOURCE_DIR}")

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sub2 / CMakeLists.txt

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

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cmake .在根目录上运行会给我这个输出

root dir CMAKE_SOURCE_DIR = /Users/henrique/cmake_tests
root dir CMAKE_CURRENT_SOURCE_DIR = /Users/henrique/cmake_tests
sub1 dir CMAKE_SOURCE_DIR = /Users/henrique/cmake_tests
sub1 dir CMAKE_CURRENT_SOURCE_DIR = /Users/henrique/cmake_tests/sub1
sub2 dir CMAKE_SOURCE_DIR = /Users/henrique/cmake_tests
sub2 dir CMAKE_CURRENT_SOURCE_DIR = /Users/henrique/cmake_tests/sub2

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现在，如果我cmake .在sub1目录上运行，则两个变量的值相同：

sub1 dir CMAKE_SOURCE_DIR = /Users/henrique/cmake_tests/sub1
sub1 dir CMAKE_CURRENT_SOURCE_DIR = /Users/henrique/cmake_tests/sub1

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