Usage of "CMAKE_MSVC_RUNTIME_LIBRARY" prior to project() or not?

Usage
1

Hi,

In CMake, some options (like CMAKE_OSX_ARCHITECTURES), should be set before the first “project()” command, which is pretty clear.

But, I need a somehow similar option, CMAKE_MSVC_RUNTIME_LIBRARY, and I want to be 100% sure that I understand the documentation correctly.

The documentation states that:
This variable has effect only when policy CMP0091 is set to NEW prior to the first project() or enable_language() command that enables a language using a compiler targeting the MSVC ABI.

And then about the policy:
This policy was introduced in CMake version 3.15. It may be set by cmake_policy() or cmake_minimum_required(). If it is not set, CMake does not warn, and uses OLD behavior.

So my question is: is the following code correct, or should I do something else before using “project()” command?

cmake_minimum_required(VERSION 3.15)
project(test C CXX)
set(CMAKE_MSVC_RUNTIME_LIBRARY “MultiThreaded$<$CONFIG:Debug:Debug>”)

Thank you

2

I think only the policy needs to be set before compiler detection (so that the configuration-based flags can avoid mentioning any of the runtime selection flags). The variable/property can be set at any point after that.

3

Thank you for your answer, I understood this way, also.

But after this, seems that if set “cmake_minimum_required”, the policy is not needed anymore, and I am not sure about this. Also in “Professional CMake” it states something similar.

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4

Yes, saying that your minimum version is 3.X opts into the NEW behavior of all policies introduced as of 3.X.