# FindMatlab

Finds MATLAB or MATLAB Compiler Runtime (MCR) and provides its tools, libraries and compilers to CMake:

    find_package(Matlab [<version>] [COMPONENTS <components>...] [REGISTRY_VIEW <view>] [...])

The primary purpose of this module is to find the libraries associated with MATLAB or the MCR in order to be able to build MATLAB extensions (MEX files). It can also be used:

- to run specific commands in MATLAB in case MATLAB is available

- for declaring MATLAB unit tests

- to retrieve various information from MATLAB (MEX extensions, versions and release queries, ...)

Added in version 3.12: MATLAB Compiler Runtime (MCR) support.

Added in version 3.30: Support for specifying a version range to `find_package()`, support for specifying `REGISTRY_VIEW` argument to `find_package()`, `matlab_extract_all_installed_versions_from_registry()` and `matlab_get_all_valid_matlab_roots_from_registry()` commands. The default behavior remained unchanged, by using the registry view `TARGET`.

Note

The version given to the `find_package()` argument is the MATLAB version, which should not be confused with the MATLAB release name (e.g. `R2023b`). The `matlab_get_version_from_release_name()` and `matlab_get_release_name_from_version()` commands provide a mapping between the release name and the version.

## Components

This module supports optional components which can be specified using the `find_package()` command:

    find_package(Matlab [COMPONENTS <components>...])

Supported components include:

`ENG_LIBRARY`

  Added in version 3.3.

  Finds the `ENG` library of MATLAB.

`MAT_LIBRARY`

  Added in version 3.7.

  Finds the `MAT` library of MATLAB.

`MAIN_PROGRAM`

  Added in version 3.3.

  Finds the MATLAB binary program. Note that this component is not available on the MCR version, and will yield an error if the MCR is found instead of the regular MATLAB installation.

`MEX_COMPILER`

  Added in version 3.3.

  Finds the MEX compiler.

`MCC_COMPILER`

  Added in version 3.13.

  Finds the MCC compiler, included with the MATLAB Compiler add-on.

`SIMULINK`

  Added in version 3.3.

  Finds the Simulink environment.

### Implicitly Found Components

The following components are always found unconditionally, without needing to be specified explicitly:

`MX_LIBRARY`

  Changed in version 3.14: This component has been removed and is now always found unconditionally.

  Added in version 3.3.

  Finds the MATLAB mx library.

`ENGINE_LIBRARY`

  Changed in version 3.14: This component has been removed and is now always found unconditionally.

  Added in version 3.13.

  Finds the MATLAB engine library.

`DATAARRAY_LIBRARY`

  Changed in version 3.14: This component has been removed and is now always found unconditionally.

  Added in version 3.13.

  Finds the C++ MATLAB data array library.

If no components are specified, the module looks for the `MX_LIBRARY`, `ENGINE_LIBRARY`, and `DATAARRAY_LIBRARY` by default.

## Imported Targets

This module provides the following Imported Targets:

`Matlab::mex`

  Added in version 3.22.

  Target encapsulating the `mex` library usage requirements, always available for MATLAB installations. Available for MCR installations if provided by MCR.

`Matlab::mx`

  Added in version 3.22.

  Target encapsulating the usage requirements of the mx library of MATLAB (arrays), always available for MATLAB installations. Available for MCR installations if provided by MCR.

`Matlab::eng`

  Added in version 3.22.

  Target encapsulating the MATLAB engine library usage requirements. Available only if the `ENG_LIBRARY` component is requested.

`Matlab::mat`

  Added in version 3.22.

  Target encapsulating the MATLAB matrix library usage requirements. Available only if the `MAT_LIBRARY` component is requested.

`Matlab::MatlabEngine`

  Added in version 3.22.

  Target encapsulating the MATLAB C++ engine library usage requirements, always available for MATLAB R2018a and newer. Available for MCR installations if provided by MCR.

`Matlab::MatlabDataArray`

  Added in version 3.22.

  Target encapsulating the MATLAB C++ data array library usage requirements, always available for MATLAB R2018a and newer. Available for MCR installations if provided by MCR.

## Result Variables

This module defines the following variables:

`Matlab_FOUND`

  Added in version 3.3.

  Boolean indicating whether the (requested version of) MATLAB installation was found. All variables below are defined if MATLAB is found.

`Matlab_VERSION`

  Added in version 3.27.

  The numerical version (e.g. `23.2.0`) of MATLAB found. Not to be confused with MATLAB release name (e.g. `R2023b`) that can be obtained with `matlab_get_release_name_from_version()`.

  When a MATLAB/MCR installation is found automatically and the `Matlab_VERSION` is not given, the version is queried from MATLAB directly (on Windows this may pop up a MATLAB window) or from the MCR installation.

`Matlab_ROOT_DIR`

  Added in version 3.3.

  The final root of the MATLAB installation determined by this module.

`Matlab_MAIN_PROGRAM`

  Added in version 3.3.

  The MATLAB binary program. Available only if the component `MAIN_PROGRAM` is given in the `find_package()` argument.

`Matlab_INCLUDE_DIRS`

  Added in version 3.3.

  The path of the MATLAB libraries headers.

`Matlab_MEX_LIBRARY`

  Library for MEX, always available for MATLAB installations. Available for MCR installations if provided by MCR.

`Matlab_MX_LIBRARY`

  The mx library of MATLAB (arrays), always available for MATLAB installations. Available for MCR installations if provided by MCR.

`Matlab_ENG_LIBRARY`

  MATLAB engine library. Available only if the component `ENG_LIBRARY` is requested.

`Matlab_MAT_LIBRARY`

  Added in version 3.7.

  Matlab matrix library. Available only if the component `MAT_LIBRARY` is requested.

`Matlab_ENGINE_LIBRARY`

  Added in version 3.13.

  Matlab C++ engine library, always available for MATLAB R2018a and newer. Available for MCR installations if provided by MCR.

`Matlab_DATAARRAY_LIBRARY`

  Added in version 3.13.

  Matlab C++ data array library, always available for MATLAB R2018a and newer. Available for MCR installations if provided by MCR.

`Matlab_LIBRARIES`

  The whole set of libraries of MATLAB.

`Matlab_MEX_COMPILER`

  Added in version 3.3.

  The MEX compiler of MATLAB. Currently not used. Available only if the component `MEX_COMPILER` is requested.

`Matlab_MCC_COMPILER`

  Added in version 3.13.

  The mcc compiler of MATLAB. Included with the MATLAB Compiler add-on. Available only if the component `MCC_COMPILER` is requested.

## Cache Variables

The following cache variables may also be set:

`Matlab_MEX_EXTENSION`

  Added in version 3.3.

  The extension of the MEX files for the current platform (given by MATLAB).

`Matlab_ROOT_DIR`

  Added in version 3.3.

  The location of the root of the MATLAB installation found. If this value is changed by the user, the result variables are recomputed.

## Input Variables

Users or projects may set the following variables to configure the module behavior before calling `find_package(Matlab)`:

`Matlab_ROOT`

  Added in version 3.25.

  Default value for the `Matlab_ROOT_DIR` variable, the root of the MATLAB installation.

`Matlab_ROOT_DIR`

  Added in version 3.3.

  The root folder of the MATLAB installation. If set before the call to `find_package()`, the module will look for the components in that path. If not set, then an automatic search of MATLAB will be performed. If set, it should point to a valid version of MATLAB.

  This variable may be specified in order to give the path of the desired MATLAB version. Otherwise, the behavior is platform specific:

  - Windows: The installed versions of MATLAB/MCR are retrieved from the Windows registry. The `REGISTRY_VIEW` argument may optionally be specified to manually control whether 32bit or 64bit versions shall be searched for.

  - macOS: The installed versions of MATLAB/MCR are given by the MATLAB default installation paths under `$HOME/Applications` and `/Applications`. If no such application is found, it falls back to the one that might be accessible from the `PATH`.

  - Unix: The desired MATLAB should be accessible from the `PATH`. This does not work for MCR installation and `Matlab_ROOT_DIR` should be specified on this platform.

`MATLAB_FIND_DEBUG`

  Added in version 3.3.

  If set to a boolean true, additional debug information is outputted to the console, such as the lookup of MATLAB and the intermediate configuration steps.

`MATLAB_ADDITIONAL_VERSIONS`

  Added in version 3.3.

  If set, it specifies additional versions of MATLAB for the automatic retrieval of the installed versions that may be handled and looked for.

  The mapping of the release names and the version of MATLAB is performed by defining pairs (name, version). The variable should be a list of strings, organized by pairs of release name and versions, such as follows:

      set(
        MATLAB_ADDITIONAL_VERSIONS
          "release_name1=corresponding_version1"
          "release_name2=corresponding_version2"
          # ...
      )

      find_package(Matlab)

  Example:

      set(
        MATLAB_ADDITIONAL_VERSIONS
          "R2013b=8.2"
          "R2013a=8.1"
          "R2012b=8.0"
          # ...
      )

      find_package(Matlab)

  The order of entries in this list matters when several versions of MATLAB are installed. The priority is set according to the ordering in this list.

## Commands

This module provides the following commands:

- `matlab_get_version_from_release_name()`

- `matlab_get_release_name_from_version()`

- `matlab_get_version_from_matlab_run()`

- `matlab_extract_all_installed_versions_from_registry()`

- `matlab_get_all_valid_matlab_roots_from_registry()`

- `matlab_add_mex()`

- `matlab_get_mex_suffix()`

- `matlab_add_unit_test()`

matlab_get_version_from_release_name

  Added in version 3.3.

  Returns the version of MATLAB from a release name:

      matlab_get_version_from_release_name(<release-name> <version-var>)

  The arguments are:

  `<release-name>`

    Input release name string (e.g. `R2023b`).

  `<version-var>`

    The name of the variable in which to store the version of MATLAB. The output result is e.g. `23.2.0`.

  Note

  This command provides correct versions mappings for MATLAB but not MCR.

matlab_get_release_name_from_version

  Added in version 3.3.

  Returns the release name from the version of MATLAB:

      matlab_get_release_name_from_version(<version> <release-name-var>)

  The arguments are:

  `<version>`

    Input MATLAB version string (e.g. `23.2.0`).

  `<release-name-var>`

    The name of the variable in which to store the MATLAB release name. The output result is e.g. `R2023b`.

  Note

  This command provides correct version mappings for MATLAB but not MCR.

matlab_get_version_from_matlab_run

  Added in version 3.3.

  Runs the specified MATLAB program and extracts the version of MATLAB/MCR, given the full directory of the MATLAB/MCR installation path:

      matlab_get_version_from_matlab_run(<matlab-binary> <matlab-versions-var>)

  The arguments are:

  `<matlab-binary>`

    The path to the `matlab` binary executable.

  `<matlab-versions-var>`

    The name of the variable in which a list of extracted MATLAB versions are stored.

  If the path provided for the MATLAB installation points to an MCR installation, the version is extracted from the installed files.

matlab_extract_all_installed_versions_from_registry

  Added in version 3.3.

  Parses the Windows registry and finds all installed MATLAB versions:

  matlab_extract_all_installed_versions_from_registry(<versions-var> [REGISTRY_VIEW <view>])

  The arguments are:

  `<versions-var>`

    The name of the variable in which to store the list of all MATLAB versions found.

  `REGISTRY_VIEW <view>`

    Added in version 3.30.

    Optional registry view argument that provides a more precise interface on how to interact with the Windows Registry. The argument is passed (or omitted) to `cmake_host_system_information()` without further checks or modification. For example, `<view>` value can be one of `64`, `32`, `64_32`, `32_64`, `HOST`, `TARGET`, `BOTH`.

  The old signature is:

  matlab_extract_all_installed_versions_from_registry(<win64> <versions-var>)

  The arguments are:

  `<win64>`

    Boolean whether to search for the 64-bit version of MATLAB. If set to boolean true, 64-bit registry view will be searched. If set to boolean false, 32-bit registry view will be searched. For finer control, use the above signature.

  `<versions-var>`

    The name of the variable in which to store the list of all MATLAB versions found.

  This command is available on Windows only. The part of the registry parsed is dependent on the host processor.

  The returned list contains all versions under `HKLM\SOFTWARE\Mathworks\MATLAB`, `HKLM\SOFTWARE\Mathworks\MATLAB Runtime` and `HKLM\SOFTWARE\Mathworks\MATLAB Compiler Runtime` or an empty list in case an error occurred (or nothing found).

  Note

  Only the versions are provided. No check is made over the existence of the installation referenced in the registry.

matlab_get_all_valid_matlab_roots_from_registry

  Added in version 3.3.

  Returns all the possible MATLAB or MCR paths, according to a previously given list:

      matlab_get_all_valid_matlab_roots_from_registry(
        <matlab-versions>
        <matlab-roots-var>
        [REGISTRY_VIEW <view>]
      )

  This command populates the MATLAB root with valid versions of MATLAB or MATLAB Runtime (MCR) and is mainly useful for the searching of all possible MATLAB installations. Only the existing/accessible paths are kept.

  The arguments are:

  `<matlab-versions>`

    A semicolon-separated list of each of the MATLAB or MCR installations. Specify it as a single string value.

  `<matlab-roots-var>`

    The name of the variable in which to store a list of locations of each of the MATLAB or MCR installations.

    The value of this variable is organized in triplets `(type,version_number,matlab_root_path)`, where `type` indicates either `MATLAB` or `MCR`.

  `REGISTRY_VIEW <view>`

    Added in version 3.30.

    Optional registry view argument that provides a more precise interface on how to interact with the Windows Registry. The argument is passed (or omitted) to `cmake_host_system_information()` without further checks or modification. For example, `<view>` value can be one of `64`, `32`, `64_32`, `32_64`, `HOST`, `TARGET`, `BOTH`.

matlab_add_mex

  Added in version 3.3.

  Adds a target that compiles MATLAB MEX target file:

      matlab_add_mex(
        NAME <name>
        [EXECUTABLE | MODULE | SHARED]
        SRC <sources>...
        [OUTPUT_NAME <output-name>]
        [DOCUMENTATION <file>]
        [LINK_TO <targets>...]
        [R2017b | R2018a]
        [EXCLUDE_FROM_ALL]
        [NO_IMPLICIT_LINK_TO_MATLAB_LIBRARIES]
        [...]
      )

  This commands compiles the given sources with the current tool-chain in order to produce a MEX file. The final name of the produced output may be specified, as well as additional link libraries, and a documentation entry for the MEX file. Remaining arguments of the call are passed to the `add_library()` or `add_executable()` command.

  The arguments are:

  `NAME <name>`

    The name of the target.

  `SRC <sources>...`

    One or more source files to be compiled.

  `LINK_TO <targets>...`

    A list of additional link dependencies. The target links to `libmex` and `libmx` by default, unless the `NO_IMPLICIT_LINK_TO_MATLAB_LIBRARIES` option is passed.

  `OUTPUT_NAME <output-name>`

    If given, overrides the default name. The default name is the name of the target without any prefix and with `Matlab_MEX_EXTENSION` suffix.

  `DOCUMENTATION <file>`

    If given, the `<file>` will be considered as being the documentation file for the MEX file. This file is copied into the same folder without any processing, with the same name as the final MEX file, and with extension `.m`. In that case, typing `help <name>` in MATLAB prints the documentation contained in this file.

    The documentation file is not processed and should be in the following format:

        % This is the documentation
        function ret = mex_target_output_name(input1)

  `R2017b` or `R2018a`

    Added in version 3.14.

    May be given to specify the version of the C API to use: `R2017b` specifies the traditional (separate complex) C API, and corresponds to the `-R2017b` flag for the `mex` command. `R2018a` specifies the new interleaved complex C API, and corresponds to the `-R2018a` flag for the `mex` command. Ignored for MATLAB versions prior to R2018a. Defaults to `R2017b`.

  `MODULE` or `SHARED`

    Added in version 3.7.

    May be given to specify the type of library to be created.

  `EXECUTABLE`

    Added in version 3.7.

    May be given to create an executable instead of a library. If no type is given explicitly, the default type is `SHARED`.

  `EXCLUDE_FROM_ALL`

    This option has the same meaning as the `EXCLUDE_FROM_ALL` target property and is forwarded to the `add_library()`, or `add_executable()` command.

  `NO_IMPLICIT_LINK_TO_MATLAB_LIBRARIES`

    Added in version 3.24.

    This option permits to disable the automatic linking of MATLAB libraries, so that only the libraries that are actually required can be linked via the `LINK_TO` option.

matlab_get_mex_suffix

  Added in version 3.3.

  Returns the extension to be used for the MEX files (the suffix):

      matlab_get_mex_suffix(<matlab-root> <mex-suffix-var>)

  The arguments are:

  `<matlab-root>`

    The root of MATLAB/MCR installation. For example, the value of the `Matlab_ROOT_DIR` variable.

  `<mex-suffix-var>`

    The name of the variable in which the suffix will be returned.

  This command is platform and architecture dependent. It should not be called before the appropriate MATLAB root has been found.

matlab_add_unit_test

  Added in version 3.3.

  Adds a MATLAB unit test file to the project's test set of CMake/CTest:

      matlab_add_unit_test(
        NAME <name>
        UNITTEST_FILE <matlab-file-containing-unittest.m>
        [CUSTOM_TEST_COMMAND <matlab-command-to-run-as-test>]
        [UNITTEST_PRECOMMAND <matlab-command-to-run>]
        [TIMEOUT <timeout>]
        [ADDITIONAL_PATH <paths>...]
        [MATLAB_ADDITIONAL_STARTUP_OPTIONS <options>...]
        [TEST_ARGS <args>...]
        [NO_UNITTEST_FRAMEWORK]
        [WORKING_DIRECTORY <dir>]
      )

  By default, the MATLAB unit test framework will be used (>= 2013a) to run the added MATLAB script, but regular `.m` files returning an exit code can be used as well (0 indicating a success).

  This command requires the component `MAIN_PROGRAM` and hence is not available for an MCR installation.

  The unit test uses the MATLAB unittest framework (default, available starting MATLAB 2013b+) except if the option `NO_UNITTEST_FRAMEWORK` is given.

  The command expects one MATLAB test script file to be given. In the case `NO_UNITTEST_FRAMEWORK` is given, the unittest script file should contain the script to be run, plus an exit command with the exit value. This exit value will be passed to the ctest framework (0 success, non 0 failure). Additional arguments accepted by `add_test()` can be passed through `TEST_ARGS` (e.g. `CONFIGURATIONS <config> ...`).

  The arguments are:

  `NAME <name>`

    The name of the unittest in ctest.

  `UNITTEST_FILE <matlab-file-containing-unittest.m>`

    The MATLAB unittest file. Its path will be automatically added to the MATLAB path.

  `CUSTOM_TEST_COMMAND <matlab-command-to-run-as-test>`

    MATLAB script command to run as the test. If this is not set, then the following is run: `runtests('matlab_file_name'), exit(max([ans(1,:).Failed]))` where `matlab_file_name` is the `UNITTEST_FILE` without the extension.

  `UNITTEST_PRECOMMAND <matlab-command-to-run>`

    MATLAB script command to be ran before the file containing the test (e.g. GPU device initialization based on CMake variables).

  `TIMEOUT <timeout>`

    The test timeout in seconds. Defaults to 180 seconds as the MATLAB unit test may hang.

  `ADDITIONAL_PATH <paths>...`

    A list of paths to add to the MATLAB path prior to running the unit test.

  `MATLAB_ADDITIONAL_STARTUP_OPTIONS <options>`

    A list of additional option in order to run MATLAB from the command line. The `-nosplash`, `-nodesktop`, and `-nodisplay` options are always added automatically.

  `TEST_ARGS <args>...`

    Additional options provided to the add_test command. These options are added to the default options (e.g. `CONFIGURATIONS Release`).

  `NO_UNITTEST_FRAMEWORK`

    When set, indicates that the test should not use the unittest framework of MATLAB (available for versions >= R2013a).

  `WORKING_DIRECTORY <dir>`

    This will be the working directory for the test. If specified it will also be the output directory used for the log file of the test run. If not specified the temporary directory `${CMAKE_BINARY_DIR}/Matlab` will be used as the working directory and the log location.

## Known Issues

Symbol clash in a MEX target

  By default, every symbol inside a MEX file defined with the command `matlab_add_mex()` have hidden visibility, except for the entry point. This is the default behavior of the MEX compiler, which lowers the risk of symbol collision between the libraries shipped with MATLAB, and the libraries to which the MEX file is linking to. This is also the default on Windows platforms.

  However, this is not sufficient in certain case, where for instance the MEX file is linking against libraries that are already loaded by MATLAB, even if those libraries have different SONAMES. A possible solution is to hide the symbols of the libraries to which the MEX target is linking to. This can be achieved in GNU GCC compilers with the linker option `-Wl,--exclude-libs,ALL`.

Tests using GPU resources

  In case the MEX file is using the GPU and in order to be able to run unit tests on this MEX file, the GPU resources should be properly released by MATLAB. A possible solution is to make MATLAB aware of the use of the GPU resources in the session, which can be performed by a command, such as `D = gpuDevice()`, at the beginning of the test script (or via a fixture).

## Examples

Finding MATLAB and linking imported target to a project target:

    find_package(Matlab)
    target_link_libraries(example PRIVATE Matlab::mx)