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FIND XXX

Help/command/include/FIND_XXX.rst

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A short-hand signature is:

.. parsed-literal::

|FIND_XXX| (<VAR> <name> [<path>...])

The general signature is:

.. parsed-literal::

|FIND_XXX| ( <VAR> {<name> | |NAMES|} [HINTS {<path> | ENV <var>}...] [PATHS {<path> | ENV <var>}...] [REGISTRY_VIEW {64|32|64_32|32_64|HOST|TARGET|BOTH}] [PATH_SUFFIXES <suffix>...] [VALIDATOR <function>] [DOC "cache documentation string"] [NO_CACHE] [REQUIRED|OPTIONAL] [NO_DEFAULT_PATH] [NO_PACKAGE_ROOT_PATH] [NO_CMAKE_PATH] [NO_CMAKE_ENVIRONMENT_PATH] [NO_SYSTEM_ENVIRONMENT_PATH] [NO_CMAKE_SYSTEM_PATH] [NO_CMAKE_INSTALL_PREFIX] [CMAKE_FIND_ROOT_PATH_BOTH | ONLY_CMAKE_FIND_ROOT_PATH | NO_CMAKE_FIND_ROOT_PATH] )

This command is used to find a |SEARCH_XXX_DESC|.

Prior to searching, |FIND_XXX| checks if variable <VAR> is defined. If the variable is not defined, the search will be performed. If the variable is defined and its value is NOTFOUND, or ends in -NOTFOUND, the search will be performed. If the variable contains any other value the search is not performed.

.. note:: VAR is considered defined if it is available in the current scope. See the :ref:cmake-language(7) variables <CMake Language Variables> documentation for details on scopes, and the interaction of normal variables and cache entries.

The results of the search will be stored in a cache entry named <VAR>. Future calls to |FIND_XXX| will inspect this cache entry when specifying the same <VAR>. This optimization ensures successful searches will not be repeated unless the cache entry is :command:unset.

If the |SEARCH_XXX| is found the recorded value in cache entry <VAR> will be the result of the search. If nothing is found, the recorded value will be <VAR>-NOTFOUND.

Options include:

NAMES Specify one or more possible names for the |SEARCH_XXX|.

When using this to specify names with and without a version suffix, we recommend specifying the unversioned name first so that locally-built packages can be found before those provided by distributions.

HINTS, PATHS Specify directories to search in addition to the default locations. The ENV var sub-option reads paths from a system environment variable.

.. versionchanged:: 3.24 On Windows platform, it is possible to include registry queries as part of the directories, using a :ref:dedicated syntax <Find Using Windows Registry>. Such specifications will be ignored on all other platforms.

REGISTRY_VIEW .. versionadded:: 3.24

.. include:: include/FIND_XXX_REGISTRY_VIEW.rst

PATH_SUFFIXES Specify additional subdirectories to check below each directory location otherwise considered.

VALIDATOR .. versionadded:: 3.25

Specify a :command:function to be called for each candidate item found (a :command:macro cannot be provided, that will result in an error). Two arguments will be passed to the validator function: the name of a result variable, and the absolute path to the candidate item. The item will be accepted and the search will end unless the function sets the value in the result variable to false in the calling scope. The result variable will hold a true value when the validator function is entered.

.. parsed-literal::

 function(my_check validator_result_var item)
   if(NOT item MATCHES ...)
     set(${validator_result_var} FALSE PARENT_SCOPE)
   endif()
 endfunction()

 |FIND_XXX| (result NAMES ... VALIDATOR my_check)

Note that if a cached result is used, the search is skipped and any VALIDATOR is ignored. The cached result is not required to pass the validation function.

DOC Specify the documentation string for the <VAR> cache entry.

NO_CACHE .. versionadded:: 3.21

The result of the search will be stored in a normal variable rather than a cache entry.

.. note::

|FIND_XXX| will still check for ``<VAR>`` as usual, checking first for a
variable, and then a cache entry. If either indicate a previous successful
search, the search will not be performed.

.. warning::

This option should be used with caution because it can greatly increase
the cost of repeated configure steps.

REQUIRED .. versionadded:: 3.18

Stop processing with an error message if nothing is found, otherwise the search will be attempted again the next time |FIND_XXX| is invoked with the same variable.

.. versionadded:: 4.1

Every |FIND_XXX| command will be treated as ``REQUIRED`` when the
:variable:`CMAKE_FIND_REQUIRED` variable is enabled.

OPTIONAL .. versionadded:: 4.1

Ignore the value of :variable:CMAKE_FIND_REQUIRED and continue without an error message if nothing is found. Incompatible with REQUIRED.

If NO_DEFAULT_PATH is specified, then no additional paths are added to the search. If NO_DEFAULT_PATH is not specified, the search process is as follows:

.. |FIND_PACKAGE_ROOT_PREFIX_PATH_XXX_SUBDIR| replace:: |prefix_XXX_SUBDIR| for each <prefix> in the :variable:<PackageName>_ROOT CMake variable and the :envvar:<PackageName>_ROOT environment variable if called from within a find module loaded by :command:find_package(<PackageName>)

.. |CMAKE_PREFIX_PATH_XXX_SUBDIR| replace:: |prefix_XXX_SUBDIR| for each <prefix> in :variable:CMAKE_PREFIX_PATH

.. |ENV_CMAKE_PREFIX_PATH_XXX_SUBDIR| replace:: |prefix_XXX_SUBDIR| for each <prefix> in :envvar:CMAKE_PREFIX_PATH

.. |SYSTEM_ENVIRONMENT_PREFIX_PATH_XXX_SUBDIR| replace:: |prefix_XXX_SUBDIR| for each <prefix>/[s]bin in PATH, and |entry_XXX_SUBDIR| for other entries in PATH

.. |CMAKE_SYSTEM_PREFIX_PATH_XXX_SUBDIR| replace:: |prefix_XXX_SUBDIR| for each <prefix> in :variable:CMAKE_SYSTEM_PREFIX_PATH

  1. If called from within a find module or any other script loaded by a call to :command:find_package(<PackageName>), search prefixes unique to the current package being found. See policy :policy:CMP0074.

    .. versionadded:: 3.12

    Specifically, search paths specified by the following variables, in order:

    a. :variable:<PackageName>_ROOT CMake variable, where <PackageName> is the case-preserved package name.

    b. :variable:<PACKAGENAME>_ROOT CMake variable, where <PACKAGENAME> is the upper-cased package name. See policy :policy:CMP0144.

    .. versionadded:: 3.27

    c. :envvar:<PackageName>_ROOT environment variable, where <PackageName> is the case-preserved package name.

    d. :envvar:<PACKAGENAME>_ROOT environment variable, where <PACKAGENAME> is the upper-cased package name. See policy :policy:CMP0144.

    .. versionadded:: 3.27

    The package root variables are maintained as a stack, so if called from nested find modules or config packages, root paths from the parent's find module or config package will be searched after paths from the current module or package. In other words, the search order would be <CurrentPackage>_ROOT, ENV{<CurrentPackage>_ROOT}, <ParentPackage>_ROOT, ENV{<ParentPackage>_ROOT}, etc. This can be skipped if NO_PACKAGE_ROOT_PATH is passed or by setting the :variable:CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE.

    • |FIND_PACKAGE_ROOT_PREFIX_PATH_XXX|

  2. Search paths specified in cmake-specific cache variables. These are intended to be used on the command line with a -DVAR=value. The values are interpreted as :ref:semicolon-separated lists <CMake Language Lists>. This can be skipped if NO_CMAKE_PATH is passed or by setting the :variable:CMAKE_FIND_USE_CMAKE_PATH to FALSE.

    • |CMAKE_PREFIX_PATH_XXX|
    • |CMAKE_XXX_PATH|
    • |CMAKE_XXX_MAC_PATH|

  3. Search paths specified in cmake-specific environment variables. These are intended to be set in the user's shell configuration, and therefore use the host's native path separator (; on Windows and : on UNIX). This can be skipped if NO_CMAKE_ENVIRONMENT_PATH is passed or by setting the :variable:CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH to FALSE.

    • |ENV_CMAKE_PREFIX_PATH_XXX|
    • |ENV_CMAKE_XXX_PATH|
    • |ENV_CMAKE_XXX_MAC_PATH|

  4. Search the paths specified by the HINTS option. These should be paths computed by system introspection, such as a hint provided by the location of another item already found. Hard-coded guesses should be specified with the PATHS option.

  5. Search the standard system environment variables. This can be skipped if NO_SYSTEM_ENVIRONMENT_PATH is passed or by setting the :variable:CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH to FALSE.

    • |SYSTEM_ENVIRONMENT_PATH_XXX|

    |SYSTEM_ENVIRONMENT_PATH_WINDOWS_XXX|

  6. Search cmake variables defined in the Platform files for the current system. The searching of CMAKE_INSTALL_PREFIX and CMAKE_STAGING_PREFIX can be skipped if NO_CMAKE_INSTALL_PREFIX is passed or by setting the :variable:CMAKE_FIND_USE_INSTALL_PREFIX to FALSE. All these locations can be skipped if NO_CMAKE_SYSTEM_PATH is passed or by setting the :variable:CMAKE_FIND_USE_CMAKE_SYSTEM_PATH to FALSE.

    • |CMAKE_SYSTEM_PREFIX_PATH_XXX|
    • |CMAKE_SYSTEM_XXX_PATH|
    • |CMAKE_SYSTEM_XXX_MAC_PATH|

    The platform paths that these variables contain are locations that typically include installed software. An example being /usr/local for UNIX based platforms.

  7. Search the paths specified by the PATHS option or in the short-hand version of the command. These are typically hard-coded guesses.

The :variable:CMAKE_IGNORE_PATH, :variable:CMAKE_IGNORE_PREFIX_PATH, :variable:CMAKE_SYSTEM_IGNORE_PATH and :variable:CMAKE_SYSTEM_IGNORE_PREFIX_PATH variables can also cause some of the above locations to be ignored.

.. versionadded:: 3.16 Added CMAKE_FIND_USE_<CATEGORY>_PATH variables to globally disable various search locations.

.. |FIND_ARGS_XXX| replace:: <VAR> NAMES name

On macOS the :variable:CMAKE_FIND_FRAMEWORK and :variable:CMAKE_FIND_APPBUNDLE variables determine the order of preference between Apple-style and unix-style package components.

.. include:: include/FIND_XXX_ROOT.rst .. include:: include/FIND_XXX_ORDER.rst