CMake/Help/policy/CMP0165.rst

CMP0165
-------

.. versionadded:: 3.30

:command:`enable_language` must not be called before :command:`project`.

In CMake 3.29 and below, if a project called :command:`enable_language`
before the first call to :command:`project`, the language would be enabled
but possibly using unset details that were expected to be set.
In CMake 3.30 and above, :command:`enable_language` prefers to reject this
case and stop with a fatal error instead if it detects that :command:`project`
has not yet been called.  This policy provides compatibility for projects that
happened to work when :command:`enable_language` was called before
:command:`project` and have not been updated to call these commands in the
required order.

The ``OLD`` behavior for this policy is to allow :command:`enable_language`
to be called before :command:`project`.  The ``NEW`` behavior for this policy
is to fail with a fatal error in such cases.

.. |INTRODUCED_IN_CMAKE_VERSION| replace:: 3.30
.. |WARNS_OR_DOES_NOT_WARN| replace:: warns
.. include:: include/STANDARD_ADVICE.rst

.. include:: include/DEPRECATED.rst