Build CMAKE\u CURRENT\u SOURCE\u DIR和；CMAKE\u源\u目录变量？

据我所知，这些变量用于项目由子目录组成的情况，例如，每个子目录都有CMakeLists.txt文件

CMAKE\u当前\u源\u目录

指正在处理的源控制器的路径？ 及

CMAKE_源目录

指最顶层的源目录？

---

我不确定

CMAKE\u SOURCE\u DIR

是最初调用CMAKE的地方，

CMAKE\u CURRENT\u SOURCE\u DIR

是CMAKE当前工作的地方。例如，如果使用

add_subdirectory

命令将依赖项包含到项目中，则依赖项将有自己的

CMAKE_CURRENT_SOURCE_DIR

但

CMAKE_SOURCE_DIR

将保持不变

扩展一些程序员的评论，想象一下您在项目的不同目录中有以下三个CMAKE文件

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)

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

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

sub1/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)

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

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

sub2/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)

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

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

在根目录上运行

cmake.

可以得到这个输出

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

现在，如果我在sub1目录上运行

cmake.

，我会得到两个变量的相同值：

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

---

你为什么不把它们打印在不同的目录里，看看它们是什么？例如，

消息（“CMAKE\u SOURCE\u DIR=${CMAKE\u SOURCE\u DIR}”）

@Someprogrammerdude你是一个了不起的人（Y）