project

Set the name of the project.

Synopsis

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 PROJECT_NAME. When called from the top-level CMakeLists.txt also stores the project name in the variable CMAKE_PROJECT_NAME.

Also sets the variables:

PROJECT_SOURCE_DIR, <PROJECT-NAME>_SOURCE_DIR

Absolute path to the source directory for the project.

PROJECT_BINARY_DIR, <PROJECT-NAME>_BINARY_DIR

Absolute path to the binary directory for the project.

PROJECT_IS_TOP_LEVEL, <PROJECT-NAME>_IS_TOP_LEVEL

New in version 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 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.

Changed in version 3.30.3: <PROJECT-NAME>_SOURCE_DIR, <PROJECT-NAME>_BINARY_DIR, and <PROJECT-NAME>_IS_TOP_LEVEL are always set as non-cache variables by project(<PROJECT-NAME> ...).

Changed in version 3.30.4: The variables <PROJECT-NAME>_SOURCE_DIR, <PROJECT-NAME>_BINARY_DIR, and <PROJECT-NAME>_IS_TOP_LEVEL are only set as non-cache variables if they are already set as cache or non-cache variables when project(<PROJECT-NAME> ...) is called. Note that this logic is flawed, as it can result in different behavior between the first and subsequent runs because cache variables won't exist on the first run, but they will on subsequent runs.

Changed in version 3.30.5: The variables <PROJECT-NAME>_SOURCE_DIR, <PROJECT-NAME>_BINARY_DIR, and <PROJECT-NAME>_IS_TOP_LEVEL are only set as non-cache variables if they are already set as non-cache variables when project(<PROJECT-NAME> ...) is called. Unlike the flawed behavior of 3.30.4, non-cache variables will not be set if only cache variables of the same name are set.

Options

The options are:

VERSION <version>

Optional; may not be used unless 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

• PROJECT_VERSION, <PROJECT-NAME>_VERSION

• PROJECT_VERSION_MAJOR, <PROJECT-NAME>_VERSION_MAJOR

• PROJECT_VERSION_MINOR, <PROJECT-NAME>_VERSION_MINOR

• PROJECT_VERSION_PATCH, <PROJECT-NAME>_VERSION_PATCH

• PROJECT_VERSION_TWEAK, <PROJECT-NAME>_VERSION_TWEAK.

New in version 3.12: When the project() command is called from the top-level CMakeLists.txt, then the version is also stored in the variable CMAKE_PROJECT_VERSION.

DESCRIPTION <project-description-string>

New in version 3.9.

Optional. Sets the variables

• PROJECT_DESCRIPTION, <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 CMAKE_PROJECT_DESCRIPTION.

New in version 3.12: Added the <PROJECT-NAME>_DESCRIPTION variable.

HOMEPAGE_URL <url-string>

New in version 3.12.

Optional. Sets the variables

• PROJECT_HOMEPAGE_URL, <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 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.

Supported languages are C, CXX (i.e. C++), CSharp (i.e. C#), CUDA, OBJC (i.e. Objective-C), OBJCXX (i.e. Objective-C++), Fortran, HIP, ISPC, Swift, ASM, ASM_NASM, ASM_MARMASM, ASM_MASM, and ASM-ATT.

New in version 3.8: Added CSharp and CUDA support.

New in version 3.15: Added Swift support.

New in version 3.16: Added OBJC and OBJCXX support.

New in version 3.18: Added ISPC support.

New in version 3.21: Added HIP support.

New in version 3.26: Added ASM_MARMASM support.

If enabling ASM, list it last so that CMake can check whether compilers for other languages like C work for assembly too.

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

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:

• New in version 3.15: For every project() call regardless of the project name, include the file(s) and module(s) named by CMAKE_PROJECT_INCLUDE_BEFORE, if set.

• New in version 3.17: If the project() command specifies <PROJECT-NAME> as its project name, include the file(s) and module(s) named by 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 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.

  • New in version 3.24: Include each file listed in 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.

• New in version 3.15: For every project() call regardless of the project name, include the file(s) and module(s) named by 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 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 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 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 CMP0000.