CMAKE_POLICY_DEFAULT_CMP<NNNN>ΒΆ
Default for CMake Policy CMP<NNNN> when it is otherwise left unset.
Commands cmake_minimum_required(VERSION) and
cmake_policy(VERSION) by default leave policies introduced after
the given version unset. Set CMAKE_POLICY_DEFAULT_CMP<NNNN> to OLD
or NEW to specify the default for policy CMP<NNNN>, where <NNNN>
is the policy number.
This variable should not be set by a project in CMake code as a way to
set its own policies; use cmake_policy(SET) instead. This
variable is meant to externally set policies for which a project has
not itself been updated:
Users running CMake may set this variable in the cache (e.g.
-DCMAKE_POLICY_DEFAULT_CMP<NNNN>=<OLD|NEW>). Set it toOLDto quiet a policy warning while using old behavior or toNEWto try building the project with new behavior.Projects may set this variable before a call to
add_subdirectory()that adds a third-party project in order to set its policies without modifying third-party code.
See CMAKE_POLICY_VERSION_MINIMUM set policies to NEW
based on the version of CMake that introduced them.