CMake/Help/command/project.rst
Brad King 6ac3712da0 Help: Document that cmake_minimum_required should be called first
Many projects put their project() call first, but the actions taken
by this command can be influenced by policies and other information
set by a call to cmake_minimum_required.  Document in each of these
two commands that cmake_minimum_required should be called first.

Suggested-by: Alan W. Irwin
2015-04-29 08:49:59 -04:00

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project
-------
Set a name, version, and enable languages for the entire project.
.. code-block:: cmake
project(<PROJECT-NAME> [LANGUAGES] [<language-name>...])
project(<PROJECT-NAME>
[VERSION <major>[.<minor>[.<patch>[.<tweak>]]]]
[LANGUAGES <language-name>...])
Sets the name of the project and stores the name in the
:variable:`PROJECT_NAME` variable. Additionally this sets variables
* :variable:`PROJECT_SOURCE_DIR`,
:variable:`<PROJECT-NAME>_SOURCE_DIR`
* :variable:`PROJECT_BINARY_DIR`,
:variable:`<PROJECT-NAME>_BINARY_DIR`
If ``VERSION`` is specified, given components must be non-negative integers.
If ``VERSION`` is not specified, the default version is the empty string.
The ``VERSION`` option may not be used unless policy :policy:`CMP0048` is
set to ``NEW``.
The :command:`project()` command stores the version number and its components
in variables
* :variable:`PROJECT_VERSION`,
:variable:`<PROJECT-NAME>_VERSION`
* :variable:`PROJECT_VERSION_MAJOR`,
:variable:`<PROJECT-NAME>_VERSION_MAJOR`
* :variable:`PROJECT_VERSION_MINOR`,
:variable:`<PROJECT-NAME>_VERSION_MINOR`
* :variable:`PROJECT_VERSION_PATCH`,
:variable:`<PROJECT-NAME>_VERSION_PATCH`
* :variable:`PROJECT_VERSION_TWEAK`,
:variable:`<PROJECT-NAME>_VERSION_TWEAK`
Variables corresponding to unspecified versions are set to the empty string
(if policy :policy:`CMP0048` is set to ``NEW``).
Optionally you can specify which languages your project supports.
Example languages are ``C``, ``CXX`` (i.e. C++), ``Fortran``, etc.
By default ``C`` and ``CXX`` are enabled if no language options are
given. Specify language ``NONE``, or use the ``LANGUAGES`` keyword
and list no languages, to skip enabling any languages.
If a variable exists called :variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE`,
the file pointed to by that variable will be included as the last step of the
project command.
The top-level ``CMakeLists.txt`` file for a project must contain a
literal, direct call to the :command:`project` command; loading one
through the :command:`include` command is not sufficient. If no such
call exists CMake will implicitly add one to the top that enables the
default languages (``C`` and ``CXX``).
.. note::
Call the :command:`cmake_minimum_required` command at the beginning
of the top-level ``CMakeLists.txt`` file even before calling the
``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`.