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project
-------
Set the name of the project.
Synopsis
^^^^^^^^
.. code-block:: cmake
project(<PROJECT-NAME> [<language-name>...])
project(<PROJECT-NAME>
[VERSION <major>[.<minor>[.<patch>[.<tweak>]]]]
[DESCRIPTION <project-description-string>]
[HOMEPAGE_URL <url-string>]
[LANGUAGES <language-name>...])
Sets the name of the project, and stores it in the variable
:variable:`PROJECT_NAME`. When called from the top-level
``CMakeLists.txt`` also stores the project name in the
variable :variable:`CMAKE_PROJECT_NAME`.
Also sets the variables:
:variable:`PROJECT_SOURCE_DIR`, :variable:`<PROJECT-NAME>_SOURCE_DIR`
Absolute path to the source directory for the project.
:variable:`PROJECT_BINARY_DIR`, :variable:`<PROJECT-NAME>_BINARY_DIR`
Absolute path to the binary directory for the project.
:variable:`PROJECT_IS_TOP_LEVEL`, :variable:`<PROJECT-NAME>_IS_TOP_LEVEL`
.. versionadded:: 3.21
Boolean value indicating whether the project is top-level.
Further variables are set by the optional arguments described in `Options`_
further below. Where an option is not given, its corresponding variable is
set to the empty string.
Note that variables of the form ``<name>_SOURCE_DIR`` and ``<name>_BINARY_DIR``
may also be set by other commands before ``project()`` is called (see the
:command:`FetchContent_MakeAvailable` command for one example).
Projects should not rely on ``<PROJECT-NAME>_SOURCE_DIR`` or
``<PROJECT-NAME>_BINARY_DIR`` holding a particular value outside of the scope
of the call to ``project()`` or one of its child scopes.
.. versionchanged:: 3.30
``<PROJECT-NAME>_SOURCE_DIR``, ``<PROJECT-NAME>_BINARY_DIR``, and
``<PROJECT-NAME>_IS_TOP_LEVEL``, if already set as normal variables when
``project(<PROJECT-NAME> ...)`` is called, are updated by the call.
Cache entries by the same names are always set as before.
See release notes for 3.30.3, 3.30.4, and 3.30.5 for details.
.. versionchanged:: 3.31
``<PROJECT-NAME>_SOURCE_DIR``, ``<PROJECT-NAME>_BINARY_DIR``, and
``<PROJECT-NAME>_IS_TOP_LEVEL`` are always set as normal variables by
``project(<PROJECT-NAME> ...)``. See policy :policy:`CMP0180`.
Cache entries by the same names are always set as before.
Options
^^^^^^^
The options are:
``VERSION <version>``
Optional; may not be used unless policy :policy:`CMP0048` is
set to ``NEW``.
Takes a ``<version>`` argument composed of non-negative integer components,
i.e. ``<major>[.<minor>[.<patch>[.<tweak>]]]``,
and sets the 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`.
.. versionadded:: 3.12
When the ``project()`` command is called from the top-level
``CMakeLists.txt``, then the version is also stored in the variable
:variable:`CMAKE_PROJECT_VERSION`.
``DESCRIPTION <project-description-string>``
.. versionadded:: 3.9
Optional.
Sets the variables
* :variable:`PROJECT_DESCRIPTION`, :variable:`<PROJECT-NAME>_DESCRIPTION`
to ``<project-description-string>``.
It is recommended that this description is a relatively short string,
usually no more than a few words.
When the ``project()`` command is called from the top-level ``CMakeLists.txt``,
then the description is also stored in the variable :variable:`CMAKE_PROJECT_DESCRIPTION`.
.. versionadded:: 3.12
Added the ``<PROJECT-NAME>_DESCRIPTION`` variable.
``HOMEPAGE_URL <url-string>``
.. versionadded:: 3.12
Optional.
Sets the variables
* :variable:`PROJECT_HOMEPAGE_URL`, :variable:`<PROJECT-NAME>_HOMEPAGE_URL`
to ``<url-string>``, which should be the canonical home URL for the project.
When the ``project()`` command is called from the top-level ``CMakeLists.txt``,
then the URL also is stored in the variable :variable:`CMAKE_PROJECT_HOMEPAGE_URL`.
``LANGUAGES <language-name>...``
Optional.
Can also be specified without ``LANGUAGES`` keyword per the first, short signature.
Selects which programming languages are needed to build the project.
.. include:: SUPPORTED_LANGUAGES.txt
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.
The variables set through the ``VERSION``, ``DESCRIPTION`` and ``HOMEPAGE_URL``
options are intended for use as default values in package metadata and documentation.
.. _`Code Injection`:
Code Injection
^^^^^^^^^^^^^^
A number of variables can be defined by the user to specify files to include
at different points during the execution of the ``project()`` command.
The following outlines the steps performed during a ``project()`` call:
* .. versionadded:: 3.15
For every ``project()`` call regardless of the project
name, include the file(s) and module(s) named by
:variable:`CMAKE_PROJECT_INCLUDE_BEFORE`, if set.
* .. versionadded:: 3.17
If the ``project()`` command specifies ``<PROJECT-NAME>`` as its project
name, include the file(s) and module(s) named by
:variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE`, if set.
* Set the various project-specific variables detailed in the `Synopsis`_
and `Options`_ sections above.
* For the very first ``project()`` call only:
* If :variable:`CMAKE_TOOLCHAIN_FILE` is set, read it at least once.
It may be read multiple times and it may also be read again when
enabling languages later (see below).
* Set the variables describing the host and target platforms.
Language-specific variables might or might not be set at this point.
On the first run, the only language-specific variables that might be
defined are those a toolchain file may have set. On subsequent runs,
language-specific variables cached from a previous run may be set.
* .. versionadded:: 3.24
Include each file listed in :variable:`CMAKE_PROJECT_TOP_LEVEL_INCLUDES`,
if set. The variable is ignored by CMake thereafter.
* Enable any languages specified in the call, or the default languages if
none were provided. The toolchain file may be re-read when enabling a
language for the first time.
* .. versionadded:: 3.15
For every ``project()`` call regardless of the project
name, include the file(s) and module(s) named by
:variable:`CMAKE_PROJECT_INCLUDE`, if set.
* If the ``project()`` command specifies ``<PROJECT-NAME>`` as its project
name, include the file(s) and module(s) named by
:variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE`, if set.
Usage
^^^^^
The top-level ``CMakeLists.txt`` file for a project must contain a
literal, direct call to the ``project()`` command; loading one
through the :command:`include` command is not sufficient. If no such
call exists, CMake will issue a warning and pretend there is a
``project(Project)`` at the top to enable the default languages
(``C`` and ``CXX``).
.. note::
Call the ``project()`` command near the top of the top-level
``CMakeLists.txt``, but *after* calling :command:`cmake_minimum_required`.
It is important to establish version and policy settings before invoking
other commands whose behavior they may affect and for this reason the
``project()`` command will issue a warning if this order is not kept.
See also policy :policy:`CMP0000`.
|
