0816482302
The CMAKE_MINIMUM_REQUIRED_VERSION has long been set by the cmake_minimum_required() command, but the command docs never mentioned this. Only the variable's own docs stated this but the variable isn't very discoverable without it being mentioned in the command's docs as well.
72 lines
2.7 KiB
ReStructuredText
72 lines
2.7 KiB
ReStructuredText
cmake_minimum_required
|
|
----------------------
|
|
|
|
Require a minimum version of cmake.
|
|
|
|
.. code-block:: cmake
|
|
|
|
cmake_minimum_required(VERSION <min>[...<max>] [FATAL_ERROR])
|
|
|
|
Sets the minimum required version of cmake for a project.
|
|
Also updates the policy settings as explained below.
|
|
|
|
``<min>`` and the optional ``<max>`` are each CMake versions of the form
|
|
``major.minor[.patch[.tweak]]``, and the ``...`` is literal.
|
|
|
|
If the running version of CMake is lower than the ``<min>`` required
|
|
version it will stop processing the project and report an error.
|
|
The optional ``<max>`` version, if specified, must be at least the
|
|
``<min>`` version and affects policy settings as described below.
|
|
If the running version of CMake is older than 3.12, the extra ``...``
|
|
dots will be seen as version component separators, resulting in the
|
|
``...<max>`` part being ignored and preserving the pre-3.12 behavior
|
|
of basing policies on ``<min>``.
|
|
|
|
This command will set the value of the
|
|
:variable:`CMAKE_MINIMUM_REQUIRED_VERSION` variable to ``<min>``.
|
|
|
|
The ``FATAL_ERROR`` option is accepted but ignored by CMake 2.6 and
|
|
higher. It should be specified so CMake versions 2.4 and lower fail
|
|
with an error instead of just a warning.
|
|
|
|
.. note::
|
|
Call the ``cmake_minimum_required()`` command at the beginning of
|
|
the top-level ``CMakeLists.txt`` file even before calling the
|
|
:command:`project` command. It is important to establish version
|
|
and policy settings before invoking other commands whose behavior
|
|
they may affect. See also policy :policy:`CMP0000`.
|
|
|
|
Calling ``cmake_minimum_required()`` inside a :command:`function`
|
|
limits some effects to the function scope when invoked. Such calls
|
|
should not be made with the intention of having global effects.
|
|
|
|
Policy Settings
|
|
^^^^^^^^^^^^^^^
|
|
|
|
The ``cmake_minimum_required(VERSION)`` command implicitly invokes the
|
|
:command:`cmake_policy(VERSION)` command to specify that the current
|
|
project code is written for the given range of CMake versions.
|
|
All policies known to the running version of CMake and introduced
|
|
in the ``<min>`` (or ``<max>``, if specified) version or earlier will
|
|
be set to use ``NEW`` behavior. All policies introduced in later
|
|
versions will be unset. This effectively requests behavior preferred
|
|
as of a given CMake version and tells newer CMake versions to warn
|
|
about their new policies.
|
|
|
|
When a ``<min>`` version higher than 2.4 is specified the command
|
|
implicitly invokes
|
|
|
|
.. code-block:: cmake
|
|
|
|
cmake_policy(VERSION <min>[...<max>])
|
|
|
|
which sets CMake policies based on the range of versions specified.
|
|
When a ``<min>`` version 2.4 or lower is given the command implicitly
|
|
invokes
|
|
|
|
.. code-block:: cmake
|
|
|
|
cmake_policy(VERSION 2.4[...<max>])
|
|
|
|
which enables compatibility features for CMake 2.4 and lower.
|