cmake - CMake 策略的范围是什么？

Question

我有一个包含多个子目录的 CMake 项目，例如:

dir1
    subdir11
    subdir12
dir2
    subdir21
    subdir22

根 CMakeLists.txt:

add_subdirectory(dir1)
add_subdirectory(dir2)

dir1 和 dir2 中的 CMakeLists 类似:

add_subdirectory(subdir11)
add_subdirectory(subdir12)

和

add_subdirectory(subdir21)
add_subdirectory(subdir22)

子目录中的 CMakeLists 做实际工作。

文件 dir1/subdir12/CMakeLists.txt设置 CMP0046政策至 OLD :

cmake_policy(SET CMP0046 OLD) #silently ignore missing dependencies

我的问题是 - CMP0046 的这个设置会传播到 subdir21和 subdir22 ?

Answer 1

不。这个问题最好直接回答from the documentation ...

Policy settings are scoped using a stack. A new level of the stack is pushed when entering a new subdirectory of the project (with add_subdirectory) and popped when leaving it. Therefore setting a policy in one directory of a project will not affect parent or sibling directories but will affect subdirectories.

要对特定级别进行临时更改，不包括 sub_directories，您可以使用

cmake_policy(PUSH)
cmake_policy(POP)

如果您希望在 subdir21 和 subdir22 中应用该策略，则需要将其显式添加到该处或考虑将其添加到公共(public)父级。