OPTIONS BUILD

.. option:: -S <path-to-source>

Path to root directory of the CMake project to build.

.. option:: -B <path-to-build>

Path to directory which CMake will use as the root of build directory.

If the directory doesn't already exist CMake will make it.

.. option:: -C <initial-cache>

Pre-load a script to populate the cache.

When CMake is first run in an empty build tree, it creates a CMakeCache.txt file and populates it with customizable settings for the project. This option may be used to specify a file from which to load cache entries before the first pass through the project's CMake listfiles. The loaded entries take priority over the project's default values. The given file should be a CMake script containing :command:set commands that use the CACHE option, not a cache-format file.

References to :variable:CMAKE_SOURCE_DIR and :variable:CMAKE_BINARY_DIR within the script evaluate to the top-level source and build tree.

.. option:: -D <var>:<type>=<value>, -D <var>=<value>

Create or update a CMake CACHE entry.

When CMake is first run in an empty build tree, it creates a CMakeCache.txt file and populates it with customizable settings for the project. This option may be used to specify a setting that takes priority over the project's default value. The option may be repeated for as many CACHE entries as desired.

If the :<type> portion is given it must be one of the types specified by the :command:set command documentation for its CACHE signature. If the :<type> portion is omitted the entry will be created with no type if it does not exist with a type already. If a command in the project sets the type to PATH or FILEPATH then the <value> will be converted to an absolute path.

This option may also be given as a single argument: -D<var>:<type>=<value> or -D<var>=<value>.

It's important to note that the order of -C and -D arguments is significant. They will be carried out in the order they are listed, with the last argument taking precedence over the previous ones. For example, if you specify -DCMAKE_BUILD_TYPE=Debug, followed by a -C argument with a file that calls:

.. code-block:: cmake

set(CMAKE_BUILD_TYPE "Release" CACHE STRING "" FORCE)

then the -C argument will take precedence, and CMAKE_BUILD_TYPE will be set to Release. However, if the -D argument comes after the -C argument, it will be set to Debug.

If a set(... CACHE ...) call in the -C file does not use FORCE, and a -D argument sets the same variable, the -D argument will take precedence regardless of order because of the nature of non-FORCE set(... CACHE ...) calls.

.. option:: -U <globbing_expr>

Remove matching entries from CMake CACHE.

This option may be used to remove one or more variables from the CMakeCache.txt file, globbing expressions using * and ? are supported. The option may be repeated for as many CACHE entries as desired.

Use with care, you can make your CMakeCache.txt non-working.

.. option:: -G <generator-name>

Specify a build system generator.

CMake may support multiple native build systems on certain platforms. A generator is responsible for generating a particular build system. Possible generator names are specified in the :manual:cmake-generators(7) manual.

If not specified, CMake checks the :envvar:CMAKE_GENERATOR environment variable and otherwise falls back to a builtin default selection.

.. option:: -T <toolset-spec>

Toolset specification for the generator, if supported.

Some CMake generators support a toolset specification to tell the native build system how to choose a compiler. See the :variable:CMAKE_GENERATOR_TOOLSET variable for details.

.. option:: -A <platform-name>

Specify platform name if supported by generator.

Some CMake generators support a platform name to be given to the native build system to choose a compiler or SDK. See the :variable:CMAKE_GENERATOR_PLATFORM variable for details.

.. option:: --toolchain <path-to-file>

.. versionadded:: 3.21

Specify the cross compiling toolchain file, equivalent to setting :variable:CMAKE_TOOLCHAIN_FILE variable. Relative paths are interpreted as relative to the build directory, and if not found, relative to the source directory.

.. option:: --install-prefix <directory>

.. versionadded:: 3.21

Specify the installation directory, used by the :variable:CMAKE_INSTALL_PREFIX variable. Must be an absolute path.

.. option:: --project-file <project-file-name>

.. versionadded:: 4.0

Specify an alternate project file name.

This determines the top-level file processed by CMake when configuring a project, and the file processed by :command:add_subdirectory.

By default, this is CMakeLists.txt. If set to anything else, CMakeLists.txt will be used as a fallback whenever the specified file cannot be found within a project subdirectory.

.. note::

This feature is intended for temporary use by developers during an incremental transition and not for publication of a final product. CMake will always emit a warning when the project file is anything other than CMakeLists.txt.

.. option:: -Wno-dev

Suppress developer warnings.

Suppress warnings that are meant for the author of the CMakeLists.txt files. By default this will also turn off deprecation warnings.

.. option:: -Wdev

Enable developer warnings.

Enable warnings that are meant for the author of the CMakeLists.txt files. By default this will also turn on deprecation warnings.

.. option:: -Wdeprecated

Enable deprecated functionality warnings.

Enable warnings for usage of deprecated functionality, that are meant for the author of the CMakeLists.txt files.

.. option:: -Wno-deprecated

Suppress deprecated functionality warnings.

Suppress warnings for usage of deprecated functionality, that are meant for the author of the CMakeLists.txt files.

.. option:: -Werror=<what>

Treat CMake warnings as errors. <what> must be one of the following:

dev Make developer warnings errors.

Make warnings that are meant for the author of the CMakeLists.txt files errors. By default this will also turn on deprecated warnings as errors.

deprecated Make deprecated macro and function warnings errors.

Make warnings for usage of deprecated macros and functions, that are meant for the author of the CMakeLists.txt files, errors.

.. option:: -Wno-error=<what>

Do not treat CMake warnings as errors. <what> must be one of the following:

dev Make warnings that are meant for the author of the CMakeLists.txt files not errors. By default this will also turn off deprecated warnings as errors.

deprecated Make warnings for usage of deprecated macros and functions, that are meant for the author of the CMakeLists.txt files, not errors.