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orocos / orocos_kinematics_dynamics

Orocos Kinematics and Dynamics C++ library
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Fix CMake warning on Windows #392

Closed jacobperron closed 2 years ago

jacobperron commented 2 years ago

Because the minimum cmake version is set to 3.0.2, we see the following policy warning on Windows:

 CMake Warning (dev) at C:/ci/ws/install/share/cmake/pybind11/pybind11Common.cmake:127 (if):
   Policy CMP0054 is not set: Only interpret if() arguments as variables or
   keywords when unquoted.  Run "cmake --help-policy CMP0054" for policy
   details.  Use the cmake_policy command to set the policy and suppress this
   warning.

   Quoted variables like "MSVC" will no longer be dereferenced when the policy
   is set to NEW.  Since the policy is not set the OLD behavior will be used.

If we want to continue to support older versions of CMake, we should opt into the new behavior to not break the logic in pybind11Common.cmake. Alternatively, we could increase the miminum cmake version of this project.

For reference, here is the line that is producing the warning:

https://github.com/pybind/pybind11/blob/v2.7.1/tools/pybind11Common.cmake#L127

With the the OLD behavior, I'm pretty sure CMake it will substitute the value of the variable MSVC into the expression "MSVC". I think we want the NEW behavior so we're comparing against the string literal "MSVC".