CMake/Help/policy/CMP0075.rst

CMP0075
-------

Include file check macros honor ``CMAKE_REQUIRED_LIBRARIES``.

In CMake 3.12 and above, the

* ``check_include_file`` macro in the :module:`CheckIncludeFile` module, the
* ``check_include_file_cxx`` macro in the
  :module:`CheckIncludeFileCXX` module, and the
* ``check_include_files`` macro in the :module:`CheckIncludeFiles` module

now prefer to link the check executable to the libraries listed in the
``CMAKE_REQUIRED_LIBRARIES`` variable.  This policy provides compatibility
with projects that have not been updated to expect this behavior.

The ``OLD`` behavior for this policy is to ignore ``CMAKE_REQUIRED_LIBRARIES``
in the include file check macros.  The ``NEW`` behavior of this policy is to
honor ``CMAKE_REQUIRED_LIBRARIES`` in the include file check macros.

This policy was introduced in CMake version 3.12.  CMake version
|release| warns when the policy is not set and uses ``OLD`` behavior.
Use the :command:`cmake_policy` command to set it to ``OLD`` or ``NEW``
explicitly.

.. include:: DEPRECATED.txt