CMAKE-COMMANDS(7)

NAME
cmake-commands - CMake Language Command Reference

SCRIPTING COMMANDS

These commands are always available.

  block

Added in version 3.25.

Evaluate a group of commands with a dedicated variable and/or policy scope.

    block([SCOPE_FOR [POLICIES] [VARIABLES]] [PROPAGATE <var-name>...])
      <commands>
    endblock()

All commands between block() and the matching endblock() are recorded without being invoked. Once the endblock() is evaluated, the recorded list of commands is invoked inside the requested scopes, then the scopes created by the block() command are removed.

SCOPE_FOR
    Specify which scopes must be created.

POLICIES
    Create a new policy scope. This is equivalent to cmake_policy(PUSH) with an automatic cmake_policy(POP) when leaving the block scope.

VARIABLES
    Create a new variable scope.

    If SCOPE_FOR is not specified, this is equivalent to:

        block(SCOPE_FOR VARIABLES POLICIES)

PROPAGATE
    When a variable scope is created by the block() command, this option sets or unsets the specified variables in the parent scope. This is equivalent to set(PARENT_SCOPE) or unset(PARENT_SCOPE) commands.

        set(var1 "INIT1")
        set(var2 "INIT2")
        set(var3 "INIT3")
        block(PROPAGATE var1 var2)
          set(var1 "VALUE1")
          unset(var2)
          set(var3 "VALUE3")
        endblock()
        # Now var1 holds VALUE1, var2 is unset, and var3 holds the initial value INIT3

    This option is only allowed when a variable scope is created. An error will be raised in the other cases.

    When the block() is inside a foreach() or while() command, the break() and continue() commands can be used inside the block.

        while(TRUE)
          block()
             ...
             # the break() command will terminate the while() command
             break()
          endblock()
        endwhile()

  See Also

•   endblock()

•   return()

•   cmake_policy()

  break

Break from an enclosing foreach or while loop.

    break()

Breaks from an enclosing foreach() or while() loop.

See also the continue() command.

  cmake_host_system_information

Query various host system information.

  Synopsis

    Query host system specific information
      cmake_host_system_information(RESULT <variable> QUERY <key> ...)
    Query Windows registry
      cmake_host_system_information(RESULT <variable> QUERY WINDOWS_REGISTRY <key> ...)

  Query host system specific information

    cmake_host_system_information(RESULT <variable> QUERY <key> ...)

Queries system information of the host system on which cmake runs. One or more <key> can be provided to select the information to be queried. The list of queried values is stored in <variable>.

<key> can be one of the following values:

NUMBER_OF_LOGICAL_CORES
    Number of logical cores

NUMBER_OF_PHYSICAL_CORES
    Number of physical cores

HOSTNAME
    Hostname

FQDN
    Fully qualified domain name

TOTAL_VIRTUAL_MEMORY
    Total virtual memory in MiB [1]

AVAILABLE_VIRTUAL_MEMORY
    Available virtual memory in MiB [1]

TOTAL_PHYSICAL_MEMORY
    Total physical memory in MiB [1]

AVAILABLE_PHYSICAL_MEMORY
    Available physical memory in MiB [1]

IS_64BIT
    Added in version 3.10.

    One if processor is 64Bit

HAS_FPU
    Added in version 3.10.

    One if processor has floating point unit

HAS_MMX
    Added in version 3.10.

    One if processor supports MMX instructions

HAS_MMX_PLUS
    Added in version 3.10.

    One if processor supports Ext. MMX instructions

HAS_SSE
    Added in version 3.10.

    One if processor supports SSE instructions

HAS_SSE2
    Added in version 3.10.

    One if processor supports SSE2 instructions

HAS_SSE_FP
    Added in version 3.10.

    One if processor supports SSE FP instructions

HAS_SSE_MMX
    Added in version 3.10.

    One if processor supports SSE MMX instructions

HAS_AMD_3DNOW
    Added in version 3.10.

    One if processor supports 3DNow instructions

HAS_AMD_3DNOW_PLUS
    Added in version 3.10.

    One if processor supports 3DNow+ instructions

HAS_IA64
    Added in version 3.10.

    One if IA64 processor emulating x86

HAS_SERIAL_NUMBER
    Added in version 3.10.

    One if processor has serial number

PROCESSOR_SERIAL_NUMBER
    Added in version 3.10.

    Processor serial number

PROCESSOR_NAME
    Added in version 3.10.

    Human readable processor name

PROCESSOR_DESCRIPTION
    Added in version 3.10.

    Human readable full processor description

OS_NAME
    Added in version 3.10.

    The host operating system name:

•   On UNIX platforms, this is uname -s.

•   On Apple platforms, this is sw_vers -productName.

•   On Windows, this is Windows.

    See also CMAKE_HOST_SYSTEM_NAME.

OS_RELEASE
    Added in version 3.10.

    The OS sub-type e.g. on Windows Professional

OS_VERSION
    Added in version 3.10.

    The OS build ID

OS_PLATFORM
    Added in version 3.10.

    See CMAKE_HOST_SYSTEM_PROCESSOR

MSYSTEM_PREFIX
    Added in version 3.28.

    Available only on Windows hosts. In a MSYS or MinGW development environment that sets the MSYSTEM environment variable, this is its installation prefix. Otherwise, this is the empty string.

DISTRIB_INFO
    Added in version 3.22.

    Read /etc/os-release file and define the given <variable> into a list of read variables

DISTRIB_<name>
    Added in version 3.22.

    Get the <name> variable (see man 5 os-release) if it exists in the /etc/os-release file

    Example:

        cmake_host_system_information(RESULT PRETTY_NAME QUERY DISTRIB_PRETTY_NAME)
        message(STATUS "${PRETTY_NAME}")
        cmake_host_system_information(RESULT DISTRO QUERY DISTRIB_INFO)
        foreach(VAR IN LISTS DISTRO)
          message(STATUS "${VAR}=`${${VAR}}`")
        endforeach()

    Output:

        -- Ubuntu 20.04.2 LTS
        -- DISTRO_BUG_REPORT_URL=`https://bugs.launchpad.net/ubuntu/`
        -- DISTRO_HOME_URL=`https://www.ubuntu.com/`
        -- DISTRO_ID=`ubuntu`
        -- DISTRO_ID_LIKE=`debian`
        -- DISTRO_NAME=`Ubuntu`
        -- DISTRO_PRETTY_NAME=`Ubuntu 20.04.2 LTS`
        -- DISTRO_PRIVACY_POLICY_URL=`https://www.ubuntu.com/legal/terms-and-policies/privacy-policy`
        -- DISTRO_SUPPORT_URL=`https://help.ubuntu.com/`
        -- DISTRO_UBUNTU_CODENAME=`focal`
        -- DISTRO_VERSION=`20.04.2 LTS (Focal Fossa)`
        -- DISTRO_VERSION_CODENAME=`focal`
        -- DISTRO_VERSION_ID=`20.04`

    If /etc/os-release file is not found, the command tries to gather OS identification via fallback scripts. The fallback script can use various distribution-specific files to collect OS identification data and map it into man 5 os-release variables.

  Fallback Interface Variables

CMAKE_GET_OS_RELEASE_FALLBACK_SCRIPTS
    In addition to the scripts shipped with CMake, a user may append full paths to his script(s) to the this list. The script filename has the following format: NNN-<name>.cmake, where NNN is three digits used to apply collected scripts in a specific order.

CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_<varname>
    Variables collected by the user provided fallback script ought to be assigned to CMake variables using this naming convention. Example, the ID variable from the manual becomes CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID.

CMAKE_GET_OS_RELEASE_FALLBACK_RESULT
    The fallback script ought to store names of all assigned CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_<varname> variables in this list.

    Example:

        # Try to detect some old distribution
        # See also
        # - http://linuxmafia.com/faq/Admin/release-files.html
        #
        if(NOT EXISTS "${CMAKE_SYSROOT}/etc/foobar-release")
          return()
        endif()
        # Get the first string only
        file(
            STRINGS "${CMAKE_SYSROOT}/etc/foobar-release" CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT
            LIMIT_COUNT 1
          )
        #
        # Example:
        #
        #   Foobar distribution release 1.2.3 (server)
        #
        if(CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT MATCHES "Foobar distribution release ([0-9\.]+) .*")
          set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_NAME Foobar)
          set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_PRETTY_NAME "${CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT}")
          set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID foobar)
          set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION ${CMAKE_MATCH_1})
          set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION_ID ${CMAKE_MATCH_1})
          list(
              APPEND CMAKE_GET_OS_RELEASE_FALLBACK_RESULT
              CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_NAME
              CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_PRETTY_NAME
              CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID
              CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION
              CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION_ID
            )
        endif()
        unset(CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT)

FOOTNOTES

[1] One MiB (mebibyte) is equal to 1024x1024 bytes.

  Query Windows registry

Added in version 3.24.

    cmake_host_system_information(RESULT <variable>
                                  QUERY WINDOWS_REGISTRY <key> [VALUE_NAMES|SUBKEYS|VALUE <name>]
                                  [VIEW (64|32|64_32|32_64|HOST|TARGET|BOTH)]
                                  [SEPARATOR <separator>]
                                  [ERROR_VARIABLE <result>])

Performs query operations on local computer registry subkey. Returns a list of subkeys or value names that are located under the specified subkey in the registry or the data of the specified value name. The result of the queried entity is stored in <variable>.

NOTE: Querying registry for any other platforms than Windows, including CYGWIN, will always returns an empty string and sets an error message in the variable specified with sub-option ERROR_VARIABLE.

<key> specify the full path of a subkey on the local computer. The <key> must include a valid root key. Valid root keys for the local computer are:

•   HKLM or HKEY_LOCAL_MACHINE

•   HKCU or HKEY_CURRENT_USER

•   HKCR or HKEY_CLASSES_ROOT

•   HKU or HKEY_USERS

•   HKCC or HKEY_CURRENT_CONFIG

    And, optionally, the path to a subkey under the specified root key. The path separator can be the slash or the backslash. <key> is not case sensitive. For example:

        cmake_host_system_information(RESULT result QUERY WINDOWS_REGISTRY "HKLM")
        cmake_host_system_information(RESULT result QUERY WINDOWS_REGISTRY "HKLM/SOFTWARE/Kitware")
        cmake_host_system_information(RESULT result QUERY WINDOWS_REGISTRY "HKCU\\SOFTWARE\\Kitware")

VALUE_NAMES
    Request the list of value names defined under <key>. If a default value is defined, it will be identified with the special name (default).

SUBKEYS
    Request the list of subkeys defined under <key>.

VALUE <name>
    Request the data stored in value named <name>. If VALUE is not specified or argument is the special name (default), the content of the default value, if any, will be returned.

        # query default value for HKLM/SOFTWARE/Kitware key
        cmake_host_system_information(RESULT result
                                      QUERY WINDOWS_REGISTRY "HKLM/SOFTWARE/Kitware")
        # query default value for HKLM/SOFTWARE/Kitware key using special value name
        cmake_host_system_information(RESULT result
                                      QUERY WINDOWS_REGISTRY "HKLM/SOFTWARE/Kitware"
                                      VALUE "(default)")

    Supported types are:

•   REG_SZ.

•   REG_EXPAND_SZ. The returned data is expanded.

•   REG_MULTI_SZ. The returned is expressed as a CMake list. See also SEPARATOR sub-option.

•   REG_DWORD.

•   REG_QWORD.

    For all other types, an empty string is returned.

VIEW
    Specify which registry views must be queried. When not specified, BOTH view is used.

64  Query the 64bit registry. On 32bit Windows, returns always an empty string.

32  Query the 32bit registry.

64_32
    For VALUE sub-option or default value, query the registry using view 64, and if the request failed, query the registry using view 32. For VALUE_NAMES and SUBKEYS sub-options, query both views (64 and 32) and merge the results (sorted and duplicates removed).

32_64
    For VALUE sub-option or default value, query the registry using view 32, and if the request failed, query the registry using view 64. For VALUE_NAMES and SUBKEYS sub-options, query both views (32 and 64) and merge the results (sorted and duplicates removed).

HOST
    Query the registry matching the architecture of the host: 64 on 64bit Windows and 32 on 32bit Windows.

TARGET
    Query the registry matching the architecture specified by CMAKE_SIZEOF_VOID_P variable. If not defined, fallback to HOST view.

BOTH
    Query both views (32 and 64). The order depends of the following rules: If CMAKE_SIZEOF_VOID_P variable is defined. Use the following view depending of the content of this variable:

•   8: 64_32

•   4: 32_64

    If CMAKE_SIZEOF_VOID_P variable is not defined, rely on architecture of the host:

•   64bit: 64_32

•   32bit: 32

SEPARATOR
    Specify the separator character for REG_MULTI_SZ type. When not specified, the character \0 is used.

ERROR_VARIABLE <result>
    Returns any error raised during query operation. In case of success, the variable holds an empty string.

  cmake_language

Added in version 3.18.

Call meta-operations on CMake commands.

  Synopsis

    cmake_language(CALL <command> [<arg>...])
    cmake_language(EVAL CODE <code>...)
    cmake_language(DEFER <options>... CALL <command> [<arg>...])
    cmake_language(SET_DEPENDENCY_PROVIDER <command> SUPPORTED_METHODS <methods>...)
    cmake_language(GET_MESSAGE_LOG_LEVEL <out-var>)
    cmake_language(EXIT <exit-code>)

  Introduction

This command will call meta-operations on built-in CMake commands or those created via the macro() or function() commands.

cmake_language does not introduce a new variable or policy scope.

  Calling Commands

cmake_language(CALL <command> [<arg>...])
    Calls the named <command> with the given arguments (if any). For example, the code:

        set(message_command "message")
        cmake_language(CALL ${message_command} STATUS "Hello World!")

    is equivalent to

        message(STATUS "Hello World!")

    NOTE: To ensure consistency of the code, the following commands are not allowed:

•   if / elseif / else / endif

•   block / endblock

•   while / endwhile

•   foreach / endforeach

•   function / endfunction

•   macro / endmacro

  Evaluating Code

cmake_language(EVAL CODE <code>...)
    Evaluates the <code>... as CMake code.

    For example, the code:

        set(A TRUE)
        set(B TRUE)
        set(C TRUE)
        set(condition "(A AND B) OR C")
        cmake_language(EVAL CODE "
          if (${condition})
            message(STATUS TRUE)
          else()
            message(STATUS FALSE)
          endif()"
        )

    is equivalent to

        set(A TRUE)
        set(B TRUE)
        set(C TRUE)
        set(condition "(A AND B) OR C")
        file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/eval.cmake "
          if (${condition})
            message(STATUS TRUE)
          else()
            message(STATUS FALSE)
          endif()"
        )
        include(${CMAKE_CURRENT_BINARY_DIR}/eval.cmake)

  Deferring Calls

Added in version 3.19.

cmake_language(DEFER <options>... CALL <command> [<arg>...])
    Schedules a call to the named <command> with the given arguments (if any) to occur at a later time. By default, deferred calls are executed as if written at the end of the current directory's CMakeLists.txt file, except that they run even after a return() call. Variable references in arguments are evaluated at the time the deferred call is executed.

    The options are:

DIRECTORY <dir>
    Schedule the call for the end of the given directory instead of the current directory. The <dir> may reference either a source directory or its corresponding binary directory. Relative paths are treated as relative to the current source directory.

    The given directory must be known to CMake, being either the top-level directory or one added by add_subdirectory(). Furthermore, the given directory must not yet be finished processing. This means it can be the current directory or one of its ancestors.

ID <id>
    Specify an identification for the deferred call. The <id> may not be empty and may not begin with a capital letter A-Z. The <id> may begin with an underscore (_) only if it was generated automatically by an earlier call that used ID_VAR to get the id.

ID_VAR <var>
    Specify a variable in which to store the identification for the deferred call. If ID <id> is not given, a new identification will be generated and the generated id will start with an underscore (_).

    The currently scheduled list of deferred calls may be retrieved:

        cmake_language(DEFER [DIRECTORY <dir>] GET_CALL_IDS <var>)

    This will store in <var> a semicolon-separated list of deferred call ids. The ids are for the directory scope in which the calls have been deferred to (i.e. where they will be executed), which can be different to the scope in which they were created. The DIRECTORY option can be used to specify the scope for which to retrieve the call ids. If that option is not given, the call ids for the current directory scope will be returned.

    Details of a specific call may be retrieved from its id:

        cmake_language(DEFER [DIRECTORY <dir>] GET_CALL <id> <var>)

    This will store in <var> a semicolon-separated list in which the first element is the name of the command to be called, and the remaining elements are its unevaluated arguments (any contained ; characters are included literally and cannot be distinguished from multiple arguments). If multiple calls are scheduled with the same id, this retrieves the first one. If no call is scheduled with the given id in the specified DIRECTORY scope (or the current directory scope if no DIRECTORY option is given), this stores an empty string in the variable.

    Deferred calls may be canceled by their id:

        cmake_language(DEFER [DIRECTORY <dir>] CANCEL_CALL <id>...)

    This cancels all deferred calls matching any of the given ids in the specified DIRECTORY scope (or the current directory scope if no DIRECTORY option is given). Unknown ids are silently ignored.

  Deferred Call Examples

For example, the code:

    cmake_language(DEFER CALL message "${deferred_message}")
    cmake_language(DEFER ID_VAR id CALL message "Canceled Message")
    cmake_language(DEFER CANCEL_CALL ${id})
    message("Immediate Message")
    set(deferred_message "Deferred Message")

prints:

    Immediate Message
    Deferred Message

The Canceled Message is never printed because its command is canceled. The deferred_message variable reference is not evaluated until the call site, so it can be set after the deferred call is scheduled.

In order to evaluate variable references immediately when scheduling a deferred call, wrap it using cmake_language(EVAL). However, note that arguments will be re-evaluated in the deferred call, though that can be avoided by using bracket arguments. For example:

    set(deferred_message "Deferred Message 1")
    set(re_evaluated [[${deferred_message}]])
    cmake_language(EVAL CODE "
      cmake_language(DEFER CALL message [[${deferred_message}]])
      cmake_language(DEFER CALL message \"${re_evaluated}\")
    ")
    message("Immediate Message")
    set(deferred_message "Deferred Message 2")

also prints:

    Immediate Message
    Deferred Message 1
    Deferred Message 2

  Dependency Providers

Added in version 3.24.

NOTE: A high-level introduction to this feature can be found in the Using Dependencies Guide.

cmake_language(SET_DEPENDENCY_PROVIDER <command> SUPPORTED_METHODS <methods>...)
    When a call is made to find_package() or FetchContent_MakeAvailable(), the call may be forwarded to a dependency provider which then has the opportunity to fulfill the request. If the request is for one of the <methods> specified when the provider was set, CMake calls the provider's <command> with a set of method-specific arguments. If the provider does not fulfill the request, or if the provider doesn't support the request's method, or no provider is set, the built-in find_package() or FetchContent_MakeAvailable() implementation is used to fulfill the request in the usual way.

    One or more of the following values can be specified for the <methods> when setting the provider:

FIND_PACKAGE
    The provider command accepts find_package() requests.

FETCHCONTENT_MAKEAVAILABLE_SERIAL
    The provider command accepts FetchContent_MakeAvailable() requests. It expects each dependency to be fed to the provider command one at a time, not the whole list in one go.

    Only one provider can be set at any point in time. If a provider is already set when cmake_language(SET_DEPENDENCY_PROVIDER) is called, the new provider replaces the previously set one. The specified <command> must already exist when cmake_language(SET_DEPENDENCY_PROVIDER) is called. As a special case, providing an empty string for the <command> and no <methods> will discard any previously set provider.

    The dependency provider can only be set while processing one of the files specified by the CMAKE_PROJECT_TOP_LEVEL_INCLUDES variable. Thus, dependency providers can only be set as part of the first call to project(). Calling cmake_language(SET_DEPENDENCY_PROVIDER) outside of that context will result in an error.

    Added in version 3.30: The PROPAGATE_TOP_LEVEL_INCLUDES_TO_TRY_COMPILE global property can be set if the dependency provider also wants to be enabled in whole-project calls to try_compile().

    NOTE: The choice of dependency provider should always be under the user's control. As a convenience, a project may choose to provide a file that users can list in their CMAKE_PROJECT_TOP_LEVEL_INCLUDES variable, but the use of such a file should always be the user's choice.

  Provider commands

Providers define a single <command> to accept requests. The name of the command should be specific to that provider, not something overly generic that another provider might also use. This enables users to compose different providers in their own custom provider. The recommended form is xxx_provide_dependency(), where xxx is the provider-specific part (e.g. vcpkg_provide_dependency(), conan_provide_dependency(), ourcompany_provide_dependency(), and so on).

    xxx_provide_dependency(<method> [<method-specific-args>...])

Because some methods expect certain variables to be set in the calling scope, the provider command should typically be implemented as a macro rather than a function. This ensures it does not introduce a new variable scope.

The arguments CMake passes to the dependency provider depend on the type of request. The first argument is always the method, and it will only ever be one of the <methods> that was specified when setting the provider.

FIND_PACKAGE
    The <method-specific-args> will be everything passed to the find_package() call that requested the dependency. The first of these <method-specific-args> will therefore always be the name of the dependency. Dependency names are case-sensitive for this method because find_package() treats them case-sensitively too.

    If the provider command fulfills the request, it must set the same variable that find_package() expects to be set. For a dependency named depName, the provider must set depName_FOUND to true if it fulfilled the request. If the provider returns without setting this variable, CMake will assume the request was not fulfilled and will fall back to the built-in implementation.

    If the provider needs to call the built-in find_package() implementation as part of its processing, it can do so by including the BYPASS_PROVIDER keyword as one of the arguments.

FETCHCONTENT_MAKEAVAILABLE_SERIAL
    The <method-specific-args> will be everything passed to the FetchContent_Declare() call that corresponds to the requested dependency, with the following exceptions:

•   If SOURCE_DIR or BINARY_DIR were not part of the original declared arguments, they will be added with their default values.

•   If FETCHCONTENT_TRY_FIND_PACKAGE_MODE is set to NEVER, any FIND_PACKAGE_ARGS will be omitted.

•   The OVERRIDE_FIND_PACKAGE keyword is always omitted.

    The first of the <method-specific-args> will always be the name of the dependency. Dependency names are case-insensitive for this method because FetchContent also treats them case-insensitively.

    If the provider fulfills the request, it should call FetchContent_SetPopulated(), passing the name of the dependency as the first argument. The SOURCE_DIR and BINARY_DIR arguments to that command should only be given if the provider makes the dependency's source and build directories available in exactly the same way as the built-in FetchContent_MakeAvailable() command.

    If the provider returns without calling FetchContent_SetPopulated() for the named dependency, CMake will assume the request was not fulfilled and will fall back to the built-in implementation.

    Note that empty arguments may be significant for this method (e.g. an empty string following a GIT_SUBMODULES keyword). Therefore, if forwarding these arguments on to another command, extra care must be taken to avoid such arguments being silently dropped.

    If FETCHCONTENT_SOURCE_DIR_<uppercaseDepName> is set, then the dependency provider will never see requests for the <depName> dependency for this method. When the user sets such a variable, they are explicitly overriding where to get that dependency from and are taking on the responsibility that their overriding version meets any requirements for that dependency and is compatible with whatever else in the project uses it. Depending on the value of FETCHCONTENT_TRY_FIND_PACKAGE_MODE and whether the OVERRIDE_FIND_PACKAGE option was given to FetchContent_Declare(), having FETCHCONTENT_SOURCE_DIR_<uppercaseDepName> set may also prevent the dependency provider from seeing requests for a find_package(depName) call too.

  Provider Examples

This first example only intercepts find_package() calls. The provider command runs an external tool which copies the relevant artifacts into a provider-specific directory, if that tool knows about the dependency. It then relies on the built-in implementation to then find those artifacts. FetchContent_MakeAvailable() calls would not go through the provider.

mycomp_provider.cmake

    # Always ensure we have the policy settings this provider expects
    cmake_minimum_required(VERSION 3.24)
    set(MYCOMP_PROVIDER_INSTALL_DIR ${CMAKE_BINARY_DIR}/mycomp_packages
      CACHE PATH "The directory this provider installs packages to"
    )
    # Tell the built-in implementation to look in our area first, unless
    # the find_package() call uses NO_..._PATH options to exclude it
    list(APPEND CMAKE_MODULE_PATH ${MYCOMP_PROVIDER_INSTALL_DIR}/cmake)
    list(APPEND CMAKE_PREFIX_PATH ${MYCOMP_PROVIDER_INSTALL_DIR})
    macro(mycomp_provide_dependency method package_name)
      execute_process(
        COMMAND some_tool ${package_name} --installdir ${MYCOMP_PROVIDER_INSTALL_DIR}
        COMMAND_ERROR_IS_FATAL ANY
      )
    endmacro()
    cmake_language(
      SET_DEPENDENCY_PROVIDER mycomp_provide_dependency
      SUPPORTED_METHODS FIND_PACKAGE
    )

The user would then typically use the above file like so:

    cmake -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES=/path/to/mycomp_provider.cmake ...

The next example demonstrates a provider that accepts both methods, but only handles one specific dependency. It enforces providing Google Test using FetchContent, but leaves all other dependencies to be fulfilled by CMake's built-in implementation. It accepts a few different names, which demonstrates one way of working around projects that hard-code an unusual or undesirable way of adding this particular dependency to the build. The example also demonstrates how to use the list() command to preserve variables that may be overwritten by a call to FetchContent_MakeAvailable().

mycomp_provider.cmake

    cmake_minimum_required(VERSION 3.24)
    # Because we declare this very early, it will take precedence over any
    # details the project might declare later for the same thing
    include(FetchContent)
    FetchContent_Declare(
      googletest
      GIT_REPOSITORY https://github.com/google/googletest.git
      GIT_TAG        e2239ee6043f73722e7aa812a459f54a28552929 # release-1.11.0
    )
    # Both FIND_PACKAGE and FETCHCONTENT_MAKEAVAILABLE_SERIAL methods provide
    # the package or dependency name as the first method-specific argument.
    macro(mycomp_provide_dependency method dep_name)
      if("${dep_name}" MATCHES "^(gtest|googletest)$")
        # Save our current command arguments in case we are called recursively
        list(APPEND mycomp_provider_args ${method} ${dep_name})
        # This will forward to the built-in FetchContent implementation,
        # which detects a recursive call for the same thing and avoids calling
        # the provider again if dep_name is the same as the current call.
        FetchContent_MakeAvailable(googletest)
        # Restore our command arguments
        list(POP_BACK mycomp_provider_args dep_name method)
        # Tell the caller we fulfilled the request
        if("${method}" STREQUAL "FIND_PACKAGE")
          # We need to set this if we got here from a find_package() call
          # since we used a different method to fulfill the request.
          # This example assumes projects only use the gtest targets,
          # not any of the variables the FindGTest module may define.
          set(${dep_name}_FOUND TRUE)
        elseif(NOT "${dep_name}" STREQUAL "googletest")
          # We used the same method, but were given a different name to the
          # one we populated with. Tell the caller about the name it used.
          FetchContent_SetPopulated(${dep_name}
            SOURCE_DIR "${googletest_SOURCE_DIR}"
            BINARY_DIR "${googletest_BINARY_DIR}"
          )
        endif()
      endif()
    endmacro()
    cmake_language(
      SET_DEPENDENCY_PROVIDER mycomp_provide_dependency
      SUPPORTED_METHODS
        FIND_PACKAGE
        FETCHCONTENT_MAKEAVAILABLE_SERIAL
    )

The final example demonstrates how to modify arguments to a find_package() call. It forces all such calls to have the QUIET keyword. It uses the BYPASS_PROVIDER keyword to prevent calling the provider command recursively for the same dependency.

mycomp_provider.cmake

    cmake_minimum_required(VERSION 3.24)
    macro(mycomp_provide_dependency method)
      find_package(${ARGN} BYPASS_PROVIDER QUIET)
    endmacro()
    cmake_language(
      SET_DEPENDENCY_PROVIDER mycomp_provide_dependency
      SUPPORTED_METHODS FIND_PACKAGE
    )

  Getting current message log level

Added in version 3.25.

cmake_language(GET_MESSAGE_LOG_LEVEL <output_variable>)
    Writes the current message() logging level into the given <output_variable>.

    See message() for the possible logging levels.

    The current message logging level can be set either using the --log-level command line option of the cmake(1) program or using the CMAKE_MESSAGE_LOG_LEVEL variable.

    If both the command line option and the variable are set, the command line option takes precedence. If neither are set, the default logging level is returned.

  Terminating Scripts

Added in version 3.29.

cmake_language(EXIT <exit-code>)
    Terminate the current cmake -P script and exit with <exit-code>.

    This command works only in script mode. If used outside of that context, it will cause a fatal error.

    The <exit-code> should be non-negative. If <exit-code> is negative, then the behavior is unspecified (e.g., on Windows the error code -1 becomes 0xffffffff, and on Linux it becomes 255). Exit codes above 255 may not be supported by the underlying shell or platform, and some shells may interpret values above 125 specially. Therefore, it is advisable to only specify an <exit-code> in the range 0 to 125.

  cmake_minimum_required

Require a minimum version of cmake.

    cmake_minimum_required(VERSION <min>[...<policy_max>] [FATAL_ERROR])

Added in version 3.12: The optional <policy_max> version behavior; ignored in older CMake.

Sets the minimum required version of cmake for a project. Also updates the policy settings as explained below.

<min> and the optional <policy_max> are each CMake versions of the form major.minor[.patch[.tweak]], and the ... is literal.

If the running version of CMake is lower than the <min> required version it will stop processing the project and report an error. The optional <policy_max> version, if specified, must be at least the <min> version and sets the Policy Version. If the running version of CMake is older than 3.12, the extra ... dots will be seen as version component separators, resulting in the ...<max> part being ignored and preserving the pre-3.12 behavior of basing policies on <min>.

This command will set the value of the CMAKE_MINIMUM_REQUIRED_VERSION variable to <min>.

The FATAL_ERROR option is accepted but ignored by CMake 2.6 and higher. It should be specified so CMake versions 2.4 and lower fail with an error instead of just a warning.

NOTE: Call the cmake_minimum_required() command at the beginning of the top-level CMakeLists.txt file even before calling the project() command. It is important to establish version and policy settings before invoking other commands whose behavior they may affect. See also policy CMP0000.

Calling cmake_minimum_required() inside a function() limits some effects to the function scope when invoked. For example, the CMAKE_MINIMUM_REQUIRED_VERSION variable won't be set in the calling scope. Functions do not introduce their own policy scope though, so policy settings of the caller will be affected (see below). Due to this mix of things that do and do not affect the calling scope, calling cmake_minimum_required() inside a function is generally discouraged.

  Policy Version

cmake_minimum_required(VERSION <min>[...<max>]) implicitly invokes

    cmake_policy(VERSION <min>[...<max>])

This specifies that the current CMake code is written for the given range of CMake versions, <min>[...<max>]. It sets the "policy version" to:

•   the range's <max> version, if specified, or to

•   the <min> version, or to

•   the value of the CMAKE_POLICY_VERSION_MINIMUM variable if it is higher than the other two versions.

    The policy version effectively requests behavior preferred as of a given CMake version and tells newer CMake versions to warn about their new policies. All policies known to the running version of CMake and introduced in that version or earlier will be set to use NEW behavior. All policies introduced in later versions will be unset (unless the CMAKE_POLICY_DEFAULT_CMP<NNNN> variable sets a default). This effectively requests behavior preferred as of a given CMake version and tells newer CMake versions to warn about their new policies.

    Changed in version 4.0: Compatibility with versions of CMake older than 3.5 is removed. Calls to cmake_minimum_required(VERSION) or cmake_policy(VERSION) that do not specify at least 3.5 as their policy version (optionally via ...<max>) will produce an error in CMake 4.0 and above.

    Changed in version 3.31: Compatibility with versions of CMake older than 3.10 is deprecated. Calls to cmake_minimum_required(VERSION) or cmake_policy(VERSION) that do not specify at least 3.10 as their policy version (optionally via ...<max>) will produce a deprecation warning in CMake 3.31 and above.

    Changed in version 3.27: Compatibility with versions of CMake older than 3.5 is deprecated. Calls to cmake_minimum_required(VERSION) or cmake_policy(VERSION) that do not specify at least 3.5 as their policy version (optionally via ...<max>) will produce a deprecation warning in CMake 3.27 and above.

    Changed in version 3.19: Compatibility with versions of CMake older than 2.8.12 is deprecated. Calls to cmake_minimum_required(VERSION) or cmake_policy(VERSION) that do not specify at least 2.8.12 as their policy version (optionally via ...<max>) will produce a deprecation warning in CMake 3.19 and above.

  See Also

•   cmake_policy()

  cmake_parse_arguments

Parse function or macro arguments.

    cmake_parse_arguments(<prefix> <options> <one_value_keywords>
                          <multi_value_keywords> <args>...)
    cmake_parse_arguments(PARSE_ARGV <N> <prefix> <options>
                          <one_value_keywords> <multi_value_keywords>)

Added in version 3.5: This command is implemented natively. Previously, it has been defined in the module CMakeParseArguments.

This command is for use in macros or functions. It processes the arguments given to that macro or function, and defines a set of variables which hold the values of the respective options.

The first signature reads arguments passed in the <args>.... This may be used in either a macro() or a function().

Added in version 3.7: The PARSE_ARGV signature is only for use in a function() body. In this case, the arguments that are parsed come from the ARGV# variables of the calling function. The parsing starts with the <N>-th argument, where <N> is an unsigned integer. This allows for the values to have special characters like ; in them.

The <options> argument contains all options for the respective function or macro. These are keywords that have no value following them, like the OPTIONAL keyword of the install() command.

The <one_value_keywords> argument contains all keywords for this function or macro which are followed by one value, like the DESTINATION keyword of the install() command.

The <multi_value_keywords> argument contains all keywords for this function or macro which can be followed by more than one value, like the TARGETS or FILES keywords of the install() command.

Changed in version 3.5: All keywords must be unique. Each keyword can only be specified once in any of the <options>, <one_value_keywords>, or <multi_value_keywords>. A warning will be emitted if uniqueness is violated.

When done, cmake_parse_arguments will consider for each of the keywords listed in <options>, <one_value_keywords>, and <multi_value_keywords>, a variable composed of the given <prefix> followed by "_" and the name of the respective keyword. For <one_value_keywords> and <multi_value_keywords>, these variables will then hold the respective value(s) from the argument list, or be undefined if the associated keyword was not given (policy CMP0174 can also affect the behavior for <one_value_keywords>). For the <options> keywords, these variables will always be defined, and they will be set to TRUE if the keyword is present, or FALSE if it is not.

All remaining arguments are collected in a variable <prefix>_UNPARSED_ARGUMENTS that will be undefined if all arguments were recognized. This can be checked afterwards to see whether your macro or function was called with unrecognized parameters.

Added in version 3.15: <one_value_keywords> and <multi_value_keywords> that were given no values at all are collected in a variable <prefix>_KEYWORDS_MISSING_VALUES that will be undefined if all keywords received values. This can be checked to see if there were keywords without any values given.

Changed in version 3.31: If a <one_value_keyword> is followed by an empty string as its value, policy CMP0174 controls whether a corresponding <prefix>_<keyword> variable is defined or not.

Choose a <prefix> carefully to avoid clashing with existing variable names. When used inside a function, it is usually suitable to use the prefix arg. There is a very strong convention that all keywords are fully uppercase, so this prefix results in variables of the form arg_SOME_KEYWORD. This makes the code more readable, and it minimizes the chance of clashing with cache variables, which also have a strong convention of being all uppercase.

    function(my_install)
        set(options OPTIONAL FAST)
        set(oneValueArgs DESTINATION RENAME)
        set(multiValueArgs TARGETS CONFIGURATIONS)
        cmake_parse_arguments(PARSE_ARGV 0 arg
            "${options}" "${oneValueArgs}" "${multiValueArgs}"
        )
        # The above will set or unset variables with the following names:
        #   arg_OPTIONAL
        #   arg_FAST
        #   arg_DESTINATION
        #   arg_RENAME
        #   arg_TARGETS
        #   arg_CONFIGURATIONS
        #
        # The following will also be set or unset:
        #   arg_UNPARSED_ARGUMENTS
        #   arg_KEYWORDS_MISSING_VALUES

When used inside a macro, arg might not be a suitable prefix because the code will affect the calling scope. If another macro also called in the same scope were to use arg in its own call to cmake_parse_arguments(), and if there are any common keywords between the two macros, the later call's variables can overwrite or remove those of the earlier macro's call. Therefore, it is advisable to incorporate something unique from the macro name in the <prefix>, such as arg_lowercase_macro_name.

    macro(my_install)
        set(options OPTIONAL FAST)
        set(oneValueArgs DESTINATION RENAME)
        set(multiValueArgs TARGETS CONFIGURATIONS)
        cmake_parse_arguments(arg_my_install
            "${options}" "${oneValueArgs}" "${multiValueArgs}"
            ${ARGN}
        )
        # ...
    endmacro()
    macro(my_special_install)
        # NOTE: Has the same keywords as my_install()
        set(options OPTIONAL FAST)
        set(oneValueArgs DESTINATION RENAME)
        set(multiValueArgs TARGETS CONFIGURATIONS)
        cmake_parse_arguments(arg_my_special_install
            "${options}" "${oneValueArgs}" "${multiValueArgs}"
            ${ARGN}
        )
        # ...
    endmacro()

Suppose the above macros are called one after the other, like so:

    my_install(TARGETS foo bar DESTINATION bin OPTIONAL blub CONFIGURATIONS)
    my_special_install(TARGETS barry DESTINATION sbin RENAME FAST)

After these two calls, the following describes the variables that will be set or unset:

    arg_my_install_OPTIONAL = TRUE
    arg_my_install_FAST = FALSE # was not present in call to my_install
    arg_my_install_DESTINATION = "bin"
    arg_my_install_RENAME <UNSET> # was not present
    arg_my_install_TARGETS = "foo;bar"
    arg_my_install_CONFIGURATIONS <UNSET> # was not present
    arg_my_install_UNPARSED_ARGUMENTS = "blub" # nothing expected after "OPTIONAL"
    arg_my_install_KEYWORDS_MISSING_VALUES = "CONFIGURATIONS" # value was missing
    arg_my_special_install_OPTIONAL = FALSE # was not present
    arg_my_special_install_FAST = TRUE
    arg_my_special_install_DESTINATION = "sbin"
    arg_my_special_install_RENAME <UNSET> # value was missing
    arg_my_special_install_TARGETS = "barry"
    arg_my_special_install_CONFIGURATIONS <UNSET> # was not present
    arg_my_special_install_UNPARSED_ARGUMENTS <UNSET>
    arg_my_special_install_KEYWORDS_MISSING_VALUES = "RENAME"

Keywords terminate lists of values. If a keyword is given directly after a <one_value_keyword>, that preceding <one_value_keyword> receives no value and the keyword is added to the <prefix>_KEYWORDS_MISSING_VALUES variable. In the above example, the call to my_special_install() contains the RENAME keyword immediately followed by the FAST keyword. In this case, FAST terminates processing of the RENAME keyword. arg_my_special_install_FAST is set to TRUE, arg_my_special_install_RENAME is unset, and arg_my_special_install_KEYWORDS_MISSING_VALUES contains the value RENAME.

  See Also

•   function()

•   macro()

  cmake_path

Added in version 3.20.

This command is for the manipulation of paths. Only syntactic aspects of paths are handled, there is no interaction of any kind with any underlying file system. The path may represent a non-existing path or even one that is not allowed to exist on the current file system or platform. For operations that do interact with the filesystem, see the file() command.

NOTE: The cmake_path command handles paths in the format of the build system (i.e. the host platform), not the target system. When cross-compiling, if the path contains elements that are not representable on the host platform (e.g. a drive letter when the host is not Windows), the results will be unpredictable.

  Synopsis

    Conventions
    Path Structure And Terminology
    Normalization
    Decomposition
      cmake_path(GET <path-var> ROOT_NAME <out-var>)
      cmake_path(GET <path-var> ROOT_DIRECTORY <out-var>)
      cmake_path(GET <path-var> ROOT_PATH <out-var>)
      cmake_path(GET <path-var> FILENAME <out-var>)
      cmake_path(GET <path-var> EXTENSION [LAST_ONLY] <out-var>)
      cmake_path(GET <path-var> STEM [LAST_ONLY] <out-var>)
      cmake_path(GET <path-var> RELATIVE_PART <out-var>)
      cmake_path(GET <path-var> PARENT_PATH <out-var>)
    Query
      cmake_path(HAS_ROOT_NAME <path-var> <out-var>)
      cmake_path(HAS_ROOT_DIRECTORY <path-var> <out-var>)
      cmake_path(HAS_ROOT_PATH <path-var> <out-var>)
      cmake_path(HAS_FILENAME <path-var> <out-var>)
      cmake_path(HAS_EXTENSION <path-var> <out-var>)
      cmake_path(HAS_STEM <path-var> <out-var>)
      cmake_path(HAS_RELATIVE_PART <path-var> <out-var>)
      cmake_path(HAS_PARENT_PATH <path-var> <out-var>)
      cmake_path(IS_ABSOLUTE <path-var> <out-var>)
      cmake_path(IS_RELATIVE <path-var> <out-var>)
      cmake_path(IS_PREFIX <path-var> <input> [NORMALIZE] <out-var>)
      cmake_path(COMPARE <input1> <OP> <input2> <out-var>)
    Modification
      cmake_path(SET <path-var> [NORMALIZE] <input>)
      cmake_path(APPEND <path-var> [<input>...] [OUTPUT_VARIABLE <out-var>])
      cmake_path(APPEND_STRING <path-var> [<input>...] [OUTPUT_VARIABLE <out-var>])
      cmake_path(REMOVE_FILENAME <path-var> [OUTPUT_VARIABLE <out-var>])
      cmake_path(REPLACE_FILENAME <path-var> <input> [OUTPUT_VARIABLE <out-var>])
      cmake_path(REMOVE_EXTENSION <path-var> [LAST_ONLY] [OUTPUT_VARIABLE <out-var>])
      cmake_path(REPLACE_EXTENSION <path-var> [LAST_ONLY] <input> [OUTPUT_VARIABLE <out-var>])
    Generation
      cmake_path(NORMAL_PATH <path-var> [OUTPUT_VARIABLE <out-var>])
      cmake_path(RELATIVE_PATH <path-var> [BASE_DIRECTORY <input>] [OUTPUT_VARIABLE <out-var>])
      cmake_path(ABSOLUTE_PATH <path-var> [BASE_DIRECTORY <input>] [NORMALIZE] [OUTPUT_VARIABLE <out-var>])
    Native Conversion
      cmake_path(NATIVE_PATH <path-var> [NORMALIZE] <out-var>)
      cmake_path(CONVERT <input> TO_CMAKE_PATH_LIST <out-var> [NORMALIZE])
      cmake_path(CONVERT <input> TO_NATIVE_PATH_LIST <out-var> [NORMALIZE])
    Hashing
      cmake_path(HASH <path-var> <out-var>)

  Conventions

The following conventions are used in this command's documentation:

<path-var>
    Always the name of a variable. For commands that expect a <path-var> as input, the variable must exist and it is expected to hold a single path.

<input>
    A string literal which may contain a path, path fragment, or multiple paths with a special separator depending on the command. See the description of each command to see how this is interpreted.

<input>...
    Zero or more string literal arguments.

<out-var>
    The name of a variable into which the result of a command will be written.

  Path Structure And Terminology

A path has the following structure (all components are optional, with some constraints):

    root-name root-directory-separator (item-name directory-separator)* filename

root-name
    Identifies the root on a filesystem with multiple roots (such as "C:" or "//myserver"). It is optional.

root-directory-separator
    A directory separator that, if present, indicates that this path is absolute. If it is missing and the first element other than the root-name is an item-name, then the path is relative.

item-name
    A sequence of characters that aren't directory separators. This name may identify a file, a hard link, a symbolic link, or a directory. Two special cases are recognized:

•   The item name consisting of a single dot character . is a directory name that refers to the current directory.

•   The item name consisting of two dot characters .. is a directory name that refers to the parent directory.

    The (...)* pattern shown above is to indicate that there can be zero or more item names, with multiple items separated by a directory-separator. The ()* characters are not part of the path.

directory-separator
    The only recognized directory separator is a forward slash character /. If this character is repeated, it is treated as a single directory separator. In other words, /usr///////lib is the same as /usr/lib.

filename
    A path has a filename if it does not end with a directory-separator. The filename is effectively the last item-name of the path, so it can also be a hard link, symbolic link or a directory.

    A filename can have an extension. By default, the extension is defined as the sub-string beginning at the left-most period (including the period) and until the end of the filename. In commands that accept a LAST_ONLY keyword, LAST_ONLY changes the interpretation to the sub-string beginning at the right-most period.

    The following exceptions apply to the above interpretation:

•   If the first character in the filename is a period, that period is ignored (i.e. a filename like ".profile" is treated as having no extension).

•   If the filename is either . or .., it has no extension.

    The stem is the part of the filename before the extension.

    Some commands refer to a root-path. This is the concatenation of root-name and root-directory-separator, either or both of which can be empty. A relative-part refers to the full path with any root-path removed.

  Creating A Path Variable

While a path can be created with care using an ordinary set() command, it is recommended to use cmake_path(SET) instead, as it automatically converts the path to the required form where required. The cmake_path(APPEND) subcommand may be another suitable alternative where a path needs to be constructed by joining fragments. The following example compares the three methods for constructing the same path:

    set(path1 "${CMAKE_CURRENT_SOURCE_DIR}/data")
    cmake_path(SET path2 "${CMAKE_CURRENT_SOURCE_DIR}/data")
    cmake_path(APPEND path3 "${CMAKE_CURRENT_SOURCE_DIR}" "data")

Modification and Generation sub-commands can either store the result in-place, or in a separate variable named after an OUTPUT_VARIABLE keyword. All other sub-commands store the result in a mandatory <out-var> variable.

  Normalization

Some sub-commands support normalizing a path. The algorithm used to normalize a path is as follows:

1.  If the path is empty, stop (the normalized form of an empty path is also an empty path).

2.  Replace each directory-separator, which may consist of multiple separators, with a single / (/a///b --> /a/b).

3.  Remove each solitary period (.) and any immediately following directory-separator (/a/./b/. --> /a/b).

4.  Remove each item-name (other than ..) that is immediately followed by a directory-separator and a .., along with any immediately following directory-separator (/a/b/../c --> a/c).

5.  If there is a root-directory, remove any .. and any directory-separators immediately following them. The parent of the root directory is treated as still the root directory (/../a --> /a).

6.  If the last item-name is .., remove any trailing directory-separator (../ --> ..).

7.  If the path is empty by this stage, add a dot (normal form of ./ is .).

  Decomposition

The following forms of the GET subcommand each retrieve a different component or group of components from a path. See Path Structure And Terminology for the meaning of each path component.

    cmake_path(GET <path-var> ROOT_NAME <out-var>)
    cmake_path(GET <path-var> ROOT_DIRECTORY <out-var>)
    cmake_path(GET <path-var> ROOT_PATH <out-var>)
    cmake_path(GET <path-var> FILENAME <out-var>)
    cmake_path(GET <path-var> EXTENSION [LAST_ONLY] <out-var>)
    cmake_path(GET <path-var> STEM [LAST_ONLY] <out-var>)
    cmake_path(GET <path-var> RELATIVE_PART <out-var>)
    cmake_path(GET <path-var> PARENT_PATH <out-var>)

If a requested component is not present in the path, an empty string will be stored in <out-var>. For example, only Windows systems have the concept of a root-name, so when the host machine is non-Windows, the ROOT_NAME subcommand will always return an empty string.

For PARENT_PATH, if the HAS_RELATIVE_PART subcommand returns false, the result is a copy of <path-var>. Note that this implies that a root directory is considered to have a parent, with that parent being itself. Where HAS_RELATIVE_PART returns true, the result will essentially be <path-var> with one less element.

  Root examples

    set(path "c:/a")
    cmake_path(GET path ROOT_NAME rootName)
    cmake_path(GET path ROOT_DIRECTORY rootDir)
    cmake_path(GET path ROOT_PATH rootPath)
    message("Root name is \"${rootName}\"")
    message("Root directory is \"${rootDir}\"")
    message("Root path is \"${rootPath}\"")

    Root name is "c:"
    Root directory is "/"
    Root path is "c:/"

  Filename examples

    set(path "/a/b")
    cmake_path(GET path FILENAME filename)
    message("First filename is \"${filename}\"")
    # Trailing slash means filename is empty
    set(path "/a/b/")
    cmake_path(GET path FILENAME filename)
    message("Second filename is \"${filename}\"")

    First filename is "b"
    Second filename is ""

  Extension and stem examples

    set(path "name.ext1.ext2")
    cmake_path(GET path EXTENSION fullExt)
    cmake_path(GET path STEM fullStem)
    message("Full extension is \"${fullExt}\"")
    message("Full stem is \"${fullStem}\"")
    # Effect of LAST_ONLY
    cmake_path(GET path EXTENSION LAST_ONLY lastExt)
    cmake_path(GET path STEM LAST_ONLY lastStem)
    message("Last extension is \"${lastExt}\"")
    message("Last stem is \"${lastStem}\"")
    # Special cases
    set(dotPath "/a/.")
    set(dotDotPath "/a/..")
    set(someMorePath "/a/.some.more")
    cmake_path(GET dotPath EXTENSION dotExt)
    cmake_path(GET dotPath STEM dotStem)
    cmake_path(GET dotDotPath EXTENSION dotDotExt)
    cmake_path(GET dotDotPath STEM dotDotStem)
    cmake_path(GET dotMorePath EXTENSION someMoreExt)
    cmake_path(GET dotMorePath STEM someMoreStem)
    message("Dot extension is \"${dotExt}\"")
    message("Dot stem is \"${dotStem}\"")
    message("Dot-dot extension is \"${dotDotExt}\"")
    message("Dot-dot stem is \"${dotDotStem}\"")
    message(".some.more extension is \"${someMoreExt}\"")
    message(".some.more stem is \"${someMoreStem}\"")

    Full extension is ".ext1.ext2"
    Full stem is "name"
    Last extension is ".ext2"
    Last stem is "name.ext1"
    Dot extension is ""
    Dot stem is "."
    Dot-dot extension is ""
    Dot-dot stem is ".."
    .some.more extension is ".more"
    .some.more stem is ".some"

  Relative part examples

    set(path "c:/a/b")
    cmake_path(GET path RELATIVE_PART result)
    message("Relative part is \"${result}\"")
    set(path "c/d")
    cmake_path(GET path RELATIVE_PART result)
    message("Relative part is \"${result}\"")
    set(path "/")
    cmake_path(GET path RELATIVE_PART result)
    message("Relative part is \"${result}\"")

    Relative part is "a/b"
    Relative part is "c/d"
    Relative part is ""

  Path traversal examples

    set(path "c:/a/b")
    cmake_path(GET path PARENT_PATH result)
    message("Parent path is \"${result}\"")
    set(path "c:/")
    cmake_path(GET path PARENT_PATH result)
    message("Parent path is \"${result}\"")

    Parent path is "c:/a"
    Parent path is "c:/"

  Query

Each of the GET subcommands has a corresponding HAS_... subcommand which can be used to discover whether a particular path component is present. See Path Structure And Terminology for the meaning of each path component.

    cmake_path(HAS_ROOT_NAME <path-var> <out-var>)
    cmake_path(HAS_ROOT_DIRECTORY <path-var> <out-var>)
    cmake_path(HAS_ROOT_PATH <path-var> <out-var>)
    cmake_path(HAS_FILENAME <path-var> <out-var>)
    cmake_path(HAS_EXTENSION <path-var> <out-var>)
    cmake_path(HAS_STEM <path-var> <out-var>)
    cmake_path(HAS_RELATIVE_PART <path-var> <out-var>)
    cmake_path(HAS_PARENT_PATH <path-var> <out-var>)

Each of the above follows the predictable pattern of setting <out-var> to true if the path has the associated component, or false otherwise. Note the following special cases:

•   For HAS_ROOT_PATH, a true result will only be returned if at least one of root-name or root-directory is non-empty.

•   For HAS_PARENT_PATH, the root directory is also considered to have a parent, which will be itself. The result is true except if the path consists of just a filename.

        cmake_path(IS_ABSOLUTE <path-var> <out-var>)

    Sets <out-var> to true if <path-var> is absolute. An absolute path is a path that unambiguously identifies the location of a file without reference to an additional starting location. On Windows, this means the path must have both a root-name and a root-directory-separator to be considered absolute. On other platforms, just a root-directory-separator is sufficient. Note that this means on Windows, IS_ABSOLUTE can be false while HAS_ROOT_DIRECTORY can be true.

        cmake_path(IS_RELATIVE <path-var> <out-var>)

    This will store the opposite of IS_ABSOLUTE in <out-var>.

        cmake_path(IS_PREFIX <path-var> <input> [NORMALIZE] <out-var>)

    Checks if <path-var> is the prefix of <input>.

    When the NORMALIZE option is specified, <path-var> and <input> are normalized before the check.

        set(path "/a/b/c")
        cmake_path(IS_PREFIX path "/a/b/c/d" result) # result = true
        cmake_path(IS_PREFIX path "/a/b" result)     # result = false
        cmake_path(IS_PREFIX path "/x/y/z" result)   # result = false
        set(path "/a/b")
        cmake_path(IS_PREFIX path "/a/c/../b" NORMALIZE result)   # result = true

        cmake_path(COMPARE <input1> EQUAL <input2> <out-var>)
        cmake_path(COMPARE <input1> NOT_EQUAL <input2> <out-var>)

    Compares the lexical representations of two paths provided as string literals. No normalization is performed on either path, except multiple consecutive directory separators are effectively collapsed into a single separator. Equality is determined according to the following pseudo-code logic:

        if(NOT <input1>.root_name() STREQUAL <input2>.root_name())
          return FALSE
        if(<input1>.has_root_directory() XOR <input2>.has_root_directory())
          return FALSE
        Return FALSE if a relative portion of <input1> is not lexicographically
        equal to the relative portion of <input2>. This comparison is performed path
        component-wise. If all of the components compare equal, then return TRUE.

    NOTE: Unlike most other cmake_path() subcommands, the COMPARE subcommand takes literal strings as input, not the names of variables.

  Modification

    cmake_path(SET <path-var> [NORMALIZE] <input>)

Assign the <input> path to <path-var>. If <input> is a native path, it is converted into a cmake-style path with forward-slashes (/). On Windows, the long filename marker is taken into account.

When the NORMALIZE option is specified, the path is normalized after the conversion.

For example:

    set(native_path "c:\\a\\b/..\\c")
    cmake_path(SET path "${native_path}")
    message("CMake path is \"${path}\"")
    cmake_path(SET path NORMALIZE "${native_path}")
    message("Normalized CMake path is \"${path}\"")

Output:

    CMake path is "c:/a/b/../c"
    Normalized CMake path is "c:/a/c"

    cmake_path(APPEND <path-var> [<input>...] [OUTPUT_VARIABLE <out-var>])

Append all the <input> arguments to the <path-var> using / as the directory-separator. Depending on the <input>, the previous contents of <path-var> may be discarded. For each <input> argument, the following algorithm (pseudo-code) applies:

    # <path> is the contents of <path-var>
    if(<input>.is_absolute() OR
       (<input>.has_root_name() AND
        NOT <input>.root_name() STREQUAL <path>.root_name()))
      replace <path> with <input>
      return()
    endif()
    if(<input>.has_root_directory())
      remove any root-directory and the entire relative path from <path>
    elseif(<path>.has_filename() OR
           (NOT <path-var>.has_root_directory() OR <path>.is_absolute()))
      append directory-separator to <path>
    endif()
    append <input> omitting any root-name to <path>

    cmake_path(APPEND_STRING <path-var> [<input>...] [OUTPUT_VARIABLE <out-var>])

Append all the <input> arguments to the <path-var> without adding any directory-separator.

    cmake_path(REMOVE_FILENAME <path-var> [OUTPUT_VARIABLE <out-var>])

Removes the filename component (as returned by GET ... FILENAME) from <path-var>. After removal, any trailing directory-separator is left alone, if present.

If OUTPUT_VARIABLE is not given, then after this function returns, HAS_FILENAME returns false for <path-var>.

For example:

    set(path "/a/b")
    cmake_path(REMOVE_FILENAME path)
    message("First path is \"${path}\"")
    # filename is now already empty, the following removes nothing
    cmake_path(REMOVE_FILENAME path)
    message("Second path is \"${path}\"")

Output:

    First path is "/a/"
    Second path is "/a/"

    cmake_path(REPLACE_FILENAME <path-var> <input> [OUTPUT_VARIABLE <out-var>])

Replaces the filename component from <path-var> with <input>. If <path-var> has no filename component (i.e. HAS_FILENAME returns false), the path is unchanged. The operation is equivalent to the following:

    cmake_path(HAS_FILENAME path has_filename)
    if(has_filename)
      cmake_path(REMOVE_FILENAME path)
      cmake_path(APPEND path input);
    endif()

    cmake_path(REMOVE_EXTENSION <path-var> [LAST_ONLY]
                                           [OUTPUT_VARIABLE <out-var>])

Removes the extension, if any, from <path-var>.

    cmake_path(REPLACE_EXTENSION <path-var> [LAST_ONLY] <input>
                                 [OUTPUT_VARIABLE <out-var>])

Replaces the extension with <input>. Its effect is equivalent to the following:

    cmake_path(REMOVE_EXTENSION path)
    if(NOT "input" MATCHES "^\\.")
      cmake_path(APPEND_STRING path ".")
    endif()
    cmake_path(APPEND_STRING path "input")

  Generation

    cmake_path(NORMAL_PATH <path-var> [OUTPUT_VARIABLE <out-var>])

Normalize <path-var> according the steps described in Normalization.

    cmake_path(RELATIVE_PATH <path-var> [BASE_DIRECTORY <input>]
                                        [OUTPUT_VARIABLE <out-var>])

Modifies <path-var> to make it relative to the BASE_DIRECTORY argument. If BASE_DIRECTORY is not specified, the default base directory will be CMAKE_CURRENT_SOURCE_DIR.

For reference, the algorithm used to compute the relative path is the same as that used by C++ std::filesystem::path::lexically_relative.

    cmake_path(ABSOLUTE_PATH <path-var> [BASE_DIRECTORY <input>] [NORMALIZE]
                                        [OUTPUT_VARIABLE <out-var>])

If <path-var> is a relative path (IS_RELATIVE is true), it is evaluated relative to the given base directory specified by BASE_DIRECTORY option. If BASE_DIRECTORY is not specified, the default base directory will be CMAKE_CURRENT_SOURCE_DIR.

When the NORMALIZE option is specified, the path is normalized after the path computation.

Because cmake_path() does not access the filesystem, symbolic links are not resolved and any leading tilde is not expanded. To compute a real path with symbolic links resolved and leading tildes expanded, use the file(REAL_PATH) command instead.

  Native Conversion

For commands in this section, native refers to the host platform, not the target platform when cross-compiling.

    cmake_path(NATIVE_PATH <path-var> [NORMALIZE] <out-var>)

Converts a cmake-style <path-var> into a native path with platform-specific slashes (\ on Windows hosts and / elsewhere).

When the NORMALIZE option is specified, the path is normalized before the conversion.

    cmake_path(CONVERT <input> TO_CMAKE_PATH_LIST <out-var> [NORMALIZE])

Converts a native <input> path into a cmake-style path with forward slashes (/). On Windows hosts, the long filename marker is taken into account. The input can be a single path or a system search path like $ENV{PATH}. A search path will be converted to a cmake-style list separated by ; characters (on non-Windows platforms, this essentially means : separators are replaced with ;). The result of the conversion is stored in the <out-var> variable.

When the NORMALIZE option is specified, the path is normalized before the conversion.

NOTE: Unlike most other cmake_path() subcommands, the CONVERT subcommand takes a literal string as input, not the name of a variable.

    cmake_path(CONVERT <input> TO_NATIVE_PATH_LIST <out-var> [NORMALIZE])

Converts a cmake-style <input> path into a native path with platform-specific slashes (\ on Windows hosts and / elsewhere). The input can be a single path or a cmake-style list. A list will be converted into a native search path (;-separated on Windows, :-separated on other platforms). The result of the conversion is stored in the <out-var> variable.

When the NORMALIZE option is specified, the path is normalized before the conversion.

NOTE: Unlike most other cmake_path() subcommands, the CONVERT subcommand takes a literal string as input, not the name of a variable.

For example:

    set(paths "/a/b/c" "/x/y/z")
    cmake_path(CONVERT "${paths}" TO_NATIVE_PATH_LIST native_paths)
    message("Native path list is \"${native_paths}\"")

Output on Windows:

    Native path list is "\a\b\c;\x\y\z"

Output on all other platforms:

    Native path list is "/a/b/c:/x/y/z"

  Hashing

    cmake_path(HASH <path-var> <out-var>)

Compute a hash value of <path-var> such that for two paths p1 and p2 that compare equal (COMPARE ... EQUAL), the hash value of p1 is equal to the hash value of p2. The path is always normalized before the hash is computed.

  cmake_pkg_config

Added in version 3.31.

Process pkg-config format package files.

  Synopsis

    cmake_pkg_config(EXTRACT <package> [<version>] [...])

  Introduction

This command generates CMake variables and targets from pkg-config format package files natively, without needing to invoke or even require the presence of a pkg-config implementation. A <package> is either an absolute path to a package file, or a package name to be searched for using the typical pkg-config search patterns. The optional <version> string has the same format and semantics as a pkg-config style version specifier, with the exception that if no comparison operator is specified = is assumed.

There are multiple signatures for this command, and some of the options are common between them. They are:

EXACT / QUIET / REQUIRED
    The EXACT option requests that the version string be matched exactly (including empty string, if no version is provided), overriding the typical pkg-config version comparison algorithm. This will ignore any comparison operator attached to the version string.

    The QUIET option disables informational messages, including those indicating that the package cannot be found if it is not REQUIRED. The REQUIRED option stops processing with an error message if the package cannot be found.

STRICTNESS <mode>
    Specify how strictly the contents of the package files will be verified during parsing and resolution. An invalid file, under the provided strictness mode, will cause the command to fail. Possible modes are:

•   STRICT: Closely mirrors the behavior of the original FDO pkg-config. Variables and keywords must be unique. Variables must be defined before they are used. The Name, Description, and Version keywords must be present. The overall structure of the file must be valid and parsable.

•   PERMISSIVE: Closely mirrors the behavior of the pkgconf implementation. Duplicate variables are overridden. Duplicate keywords are appended. Undefined variables resolve to empty strings. The Name, Description, and Version keywords must be present. The overall structure of the file must be valid and parsable.

•   BEST_EFFORT: Same behavior as PERMISSIVE with regards to duplicate or uninitialized variables and keywords, but will not fail under any conditions. Package files which require BEST_EFFORT will fail validation under all other major implementations and should be fixed.

    The default strictness is PERMISSIVE.

ENV_MODE
    Specifies which environment variables will be queried when running a given command. Possible modes are:

•   FDO: Queries only the original set of PKG_CONFIG_* environment variables used by the freedesktop.org pkg-config implementation.

•   PKGCONF: Queries the more extensive set of environment variables used by the pkgconf implementation.

•   IGNORE: Ignores the presence, absence, and value of environment variables entirely. In all cases an environment variable would be queried its treated as defined, but with a value of empty string for the purpose of the operation. This does not modify the current environment. For boolean environment variables, such as PKG_CONFIG_ALLOW_*, this means they are evaluated as truthy.

    PKG_CONFIG_SYSROOT_PATH is a minor exception. When ENV_MODE IGNORE is used, no root path prepending will occur by default and pc_sysrootdir remains defaulted to /.

    Target-generating subcommands always ignore flag-filtering environment variables. The default environment mode is PKGCONF.

PC_LIBDIR <path>...
    Overrides the default search location for package files; also used to derive the pc_path package variable.

    When this option is not provided, the default library directory is the first available of the following values:

1.  CMAKE_PKG_CONFIG_PC_LIB_DIRS

2.  The PKG_CONFIG_LIBDIR environment variable

3.  The output of pkg-config --variable pc_path pkg-config

4.  A platform-dependent default value

PC_PATH <path>...
    Overrides the supplemental package file directories which will be prepended to the search path; also used to derive the pc_path package variable.

    When this option is not provided, the default paths are the first available of the following values:

1.  CMAKE_PKG_CONFIG_PC_PATH

2.  The PKG_CONFIG_PATH environment variable

3.  Empty list

DISABLE_UNINSTALLED <bool>
    Overrides the search behavior for "uninstalled" package files. These are package files with an "-uninstalled" suffix which describe packages integrated directly from a build tree.

    Normally such package files have higher priority than "installed" packages. When DISABLE_UNINSTALLED is true, searching for "uninstalled" packages is disabled.

    When this option is not provided, the default search behavior is determined by the first available of the following values:

1.  CMAKE_PKG_CONFIG_DISABLE_UNINSTALLED

2.  If the PKG_CONFIG_DISABLE_UNINSTALLED environment variable is defined the search is disabled, otherwise it is enabled.

PC_SYSROOT_DIR <path>
    Overrides the root path which will be prepended to paths specified by -I compile flags and -L library search locations; also used to derive the pc_sysrootdir package variable.

    When this option is not provided, the default root path is provided by the first available of the following values:

1.  CMAKE_PKG_CONFIG_SYSROOT_DIR

2.  The PKG_CONFIG_SYSROOT_DIR environment variable

3.  If no root path is available, nothing will be prepended to include or library directory paths and pc_sysrootdir will be set to /

TOP_BUILD_DIR <path>
    Overrides the top build directory path used to derived the pc_top_builddir package variable.

    When this option is not provided, the default top build directory path is the first available of the following values:

1.  CMAKE_PKG_CONFIG_TOP_BUILD_DIR

2.  The PKG_CONFIG_TOP_BUILD_DIR environment variable

3.  If no top build directory path is available, the pc_top_builddir package variable is not set

  Signatures

cmake_pkg_config(EXTRACT <package> [<version>] [...])
    Extract the contents of the package into variables.

        cmake_pkg_config(EXTRACT <package> [<version>]
                        [REQUIRED] [EXACT] [QUIET]
                        [STRICTNESS <mode>]
                        [ENV_MODE <mode>]
                        [PC_LIBDIR <path>...]
                        [PC_PATH <path>...]
                        [DISABLE_UNINSTALLED <bool>]
                        [PC_SYSROOT_DIR <path>]
                        [TOP_BUILD_DIR <path>]
                        [SYSTEM_INCLUDE_DIRS <path>...]
                        [SYSTEM_LIBRARY_DIRS <path>...]
                        [ALLOW_SYSTEM_INCLUDES <bool>]
                        [ALLOW_SYSTEM_LIBS <bool>])

    The following variables will be populated from the contents of package file:
    Variable | Type | Definition
    CMAKE_PKG_CONFIG_NAME | String | Value of the Name keyword
    CMAKE_PKG_CONFIG_DESCRIPTION | String | Value of the Description keyword
    CMAKE_PKG_CONFIG_VERSION | String | Value of the Version keyword
    CMAKE_PKG_CONFIG_PROVIDES | List | Value of the Provides keyword
    CMAKE_PKG_CONFIG_REQUIRES | List | Value of the Requires keyword
    CMAKE_PKG_CONFIG_CONFLICTS | List | Value of the Conflicts keyword
    CMAKE_PKG_CONFIG_CFLAGS | String | Value of the CFlags / Cflags keyword
    CMAKE_PKG_CONFIG_INCLUDES | List | All -I prefixed flags from CMAKE_PKG_CONFIG_CFLAGS
    CMAKE_PKG_CONFIG_COMPILE_OPTIONS | List | All flags not prefixed with -I from CMAKE_PKG_CONFIG_CFLAGS
    CMAKE_PKG_CONFIG_LIBS | String | Value of the Libs keyword
    CMAKE_PKG_CONFIG_LIBDIRS | List | All -L prefixed flags from CMAKE_PKG_CONFIG_LIBS
    CMAKE_PKG_CONFIG_LIBNAMES | List | All -l prefixed flags from CMAKE_PKG_CONFIG_LIBS
    CMAKE_PKG_CONFIG_LINK_OPTIONS | List | All flags not prefixed with -L or -l from CMAKE_PKG_CONFIG_LIBS
    CMAKE_PKG_CONFIG_*_PRIVATE | * | CFLAGS / LIBS / REQUIRES and derived, but in their .private suffix forms

SYSTEM_INCLUDE_DIRS
    Overrides the "system" directories for the purpose of flag mangling include directories in CMAKE_PKG_CONFIG_CFLAGS and derived variables.

    When this option is not provided, the default directories are provided by the first available of the following values:

1.  CMAKE_PKG_CONFIG_SYS_INCLUDE_DIRS

2.  The PKG_CONFIG_SYSTEM_INCLUDE_PATH environment variable

3.  The output of pkgconf --variable pc_system_includedirs pkg-config

4.  A platform-dependent default value

    Additionally, when the ENV_MODE is PKGCONF the CMAKE_PKG_CONFIG_PKGCONF_INCLUDES variable will be concatenated to the list if available. If it is not available, the following environment variables will be queried and concatenated:

•   CPATH

•   C_INCLUDE_PATH

•   CPLUS_INCLUDE_PATH

•   OBJC_INCLUDE_PATH

•   INCLUDE (Windows Only)

SYSTEM_LIBRARY_DIRS
    Overrides the "system" directories for the purpose of flag mangling library directories in CMAKE_PKG_CONFIG_LIBS and derived variables.

    When this option is not provided, the default directories are provided by the first available of the following values:

1.  CMAKE_PKG_CONFIG_SYS_LIB_DIRS

2.  The PKG_CONFIG_SYSTEM_LIBRARY_PATH environment variable

3.  The output of pkgconf --variable pc_system_libdirs pkg-config

4.  A platform-dependent default value

    Additionally, when the ENV_MODE is PKGCONF the CMAKE_PKG_CONFIG_PKGCONF_LIB_DIRS variable will be concatenated to the list if available. If it is not available, the LIBRARY_PATH environment variable will be queried and concatenated.

ALLOW_SYSTEM_INCLUDES
    Preserves "system" directories during flag mangling of include directories in CMAKE_PKG_CONFIG_CFLAGS and derived variables.

    When this option is not provided, the default value is determined by the first available of the following values:

1.  CMAKE_PKG_CONFIG_ALLOW_SYS_INCLUDES

2.  If the PKG_CONFIG_ALLOW_SYSTEM_CFLAGS environment variable is defined the flags are preserved, otherwise they are filtered during flag mangling.

ALLOW_SYSTEM_LIBS
    Preserves "system" directories during flag mangling of library directories in CMAKE_PKG_CONFIG_LIBS and derived variables.

    When this option is not provided, the default value is determined by the first available of the following values:

1.  CMAKE_PKG_CONFIG_ALLOW_SYS_LIBS

2.  If the PKG_CONFIG_ALLOW_SYSTEM_LIBS environment variable is defined the flags are preserved, otherwise they are filtered during flag mangling.

  cmake_policy

Manage CMake Policy settings. See the cmake-policies(7) manual for defined policies.

As CMake evolves it is sometimes necessary to change existing behavior in order to fix bugs or improve implementations of existing features. The CMake Policy mechanism is designed to help keep existing projects building as new versions of CMake introduce changes in behavior. Each new policy (behavioral change) is given an identifier of the form CMP<NNNN> where <NNNN> is an integer index. Documentation associated with each policy describes the OLD and NEW behavior and the reason the policy was introduced. Projects may set each policy to select the desired behavior. When CMake needs to know which behavior to use it checks for a setting specified by the project. If no setting is available the OLD behavior is assumed and a warning is produced requesting that the policy be set.

  Setting Policies by CMake Version

The cmake_policy command is used to set policies to OLD or NEW behavior. While setting policies individually is supported, we encourage projects to set policies based on CMake versions:

cmake_policy(VERSION <min>[...<max>])

    Added in version 3.12: The optional <max> version.

    <min> and the optional <max> are each CMake versions of the form major.minor[.patch[.tweak]], and the ... is literal. The <min> version must be at least 2.4 and at most the running version of CMake. The <max> version, if specified, must be at least the <min> version but may exceed the running version of CMake. If the running version of CMake is older than 3.12, the extra ... dots will be seen as version component separators, resulting in the ...<max> part being ignored and preserving the pre-3.12 behavior of basing policies on <min>.

    This specifies that the current CMake code is written for the given range of CMake versions, <min>[...<max>]. It sets the "policy version" to:

•   the range's <max> version, if specified, or to

•   the <min> version, or to

•   the value of the CMAKE_POLICY_VERSION_MINIMUM variable if it is higher than the other two versions.

    The policy version effectively requests behavior preferred as of a given CMake version and tells newer CMake versions to warn about their new policies. All policies known to the running version of CMake and introduced in that version or earlier will be set to use NEW behavior. All policies introduced in later versions will be unset (unless the CMAKE_POLICY_DEFAULT_CMP<NNNN> variable sets a default). This effectively requests behavior preferred as of a given CMake version and tells newer CMake versions to warn about their new policies.

    Note that the cmake_minimum_required(VERSION) command implicitly calls cmake_policy(VERSION) too.

    Changed in version 4.0: Compatibility with versions of CMake older than 3.5 is removed. Calls to cmake_minimum_required(VERSION) or cmake_policy(VERSION) that do not specify at least 3.5 as their policy version (optionally via ...<max>) will produce an error in CMake 4.0 and above.

    Changed in version 3.31: Compatibility with versions of CMake older than 3.10 is deprecated. Calls to cmake_minimum_required(VERSION) or cmake_policy(VERSION) that do not specify at least 3.10 as their policy version (optionally via ...<max>) will produce a deprecation warning in CMake 3.31 and above.

    Changed in version 3.27: Compatibility with versions of CMake older than 3.5 is deprecated. Calls to cmake_minimum_required(VERSION) or cmake_policy(VERSION) that do not specify at least 3.5 as their policy version (optionally via ...<max>) will produce a deprecation warning in CMake 3.27 and above.

    Changed in version 3.19: Compatibility with versions of CMake older than 2.8.12 is deprecated. Calls to cmake_minimum_required(VERSION) or cmake_policy(VERSION) that do not specify at least 2.8.12 as their policy version (optionally via ...<max>) will produce a deprecation warning in CMake 3.19 and above.

  Setting Policies Explicitly

cmake_policy(SET CMP<NNNN> NEW|OLD)

    Tell CMake to use the OLD or NEW behavior for a given policy. Projects depending on the old behavior of a given policy may silence a policy warning by setting the policy state to OLD. Alternatively one may fix the project to work with the new behavior and set the policy state to NEW.

    NOTE: The OLD behavior of a policy is deprecated by definition and may be removed in a future version of CMake.

  Checking Policy Settings

cmake_policy(GET CMP<NNNN> <variable>)

    Check whether a given policy is set to OLD or NEW behavior. The output <variable> value will be OLD or NEW if the policy is set, and empty otherwise.

  CMake Policy Stack

CMake keeps policy settings on a stack, so changes made by the cmake_policy command affect only the top of the stack. A new entry on the policy stack is managed automatically for each subdirectory to protect its parents and siblings. CMake also manages a new entry for scripts loaded by include() and find_package() commands except when invoked with the NO_POLICY_SCOPE option (see also policy CMP0011). The cmake_policy command provides an interface to manage custom entries on the policy stack:

cmake_policy(PUSH)
    Create a new entry on the policy stack.

cmake_policy(POP)
    Remove the last policy stack entry created with cmake_policy(PUSH).

    Each PUSH must have a matching POP to erase any changes. This is useful to make temporary changes to policy settings. Calls to the cmake_minimum_required(VERSION), cmake_policy(VERSION), or cmake_policy(SET) commands influence only the current top of the policy stack.

    Added in version 3.25: The block(SCOPE_FOR POLICIES) command offers a more flexible and more secure way to manage the policy stack. The pop action is done automatically when leaving the block scope, so there is no need to precede each return() with a call to cmake_policy(POP).

        # stack management with cmake_policy()
        function(my_func)
          cmake_policy(PUSH)
          cmake_policy(SET ...)
          if (<cond1>)
            ...
            cmake_policy(POP)
            return()
          elseif(<cond2>)
            ...
            cmake_policy(POP)
            return()
          endif()
          ...
          cmake_policy(POP)
        endfunction()
        # stack management with block()/endblock()
        function(my_func)
          block(SCOPE_FOR POLICIES)
            cmake_policy(SET ...)
            if (<cond1>)
              ...
              return()
            elseif(<cond2>)
              ...
              return()
            endif()
            ...
          endblock()
        endfunction()

    Commands created by the function() and macro() commands record policy settings when they are created and use the pre-record policies when they are invoked. If the function or macro implementation sets policies, the changes automatically propagate up through callers until they reach the closest nested policy stack entry.

  See Also

•   cmake_minimum_required()

  configure_file

Copy a file to another location and modify its contents.

    configure_file(<input> <output>
                   [NO_SOURCE_PERMISSIONS | USE_SOURCE_PERMISSIONS |
                    FILE_PERMISSIONS <permissions>...]
                   [COPYONLY] [ESCAPE_QUOTES] [@ONLY]
                   [NEWLINE_STYLE [UNIX|DOS|WIN32|LF|CRLF]])

Copies an <input> file to an <output> file while performing transformations of the input file content.

If the input file is modified the build system will re-run CMake to re-configure the file and generate the build system again. The generated file is modified and its timestamp updated on subsequent cmake runs only if its content is changed.

  Options

The options are:

<input>
    Path to the input file. A relative path is treated with respect to the value of CMAKE_CURRENT_SOURCE_DIR. The input path must be a file, not a directory.

<output>
    Path to the output file or directory. A relative path is treated with respect to the value of CMAKE_CURRENT_BINARY_DIR. If the path names an existing directory the output file is placed in that directory with the same file name as the input file. If the path contains non-existent directories, they are created.

NO_SOURCE_PERMISSIONS
    Added in version 3.19.

    Do not transfer the permissions of the input file to the output file. The copied file permissions default to the standard 644 value (-rw-r--r--).

USE_SOURCE_PERMISSIONS
    Added in version 3.20.

    Transfer the permissions of the input file to the output file. This is already the default behavior if none of the three permissions-related keywords are given (NO_SOURCE_PERMISSIONS, USE_SOURCE_PERMISSIONS or FILE_PERMISSIONS). The USE_SOURCE_PERMISSIONS keyword mostly serves as a way of making the intended behavior clearer at the call site.

FILE_PERMISSIONS <permissions>...
    Added in version 3.20.

    Ignore the input file's permissions and use the specified <permissions> for the output file instead.

COPYONLY
    Copy the file without replacing any variable references or other content. This option may not be used with NEWLINE_STYLE.

ESCAPE_QUOTES
    Escape any substituted quotes with backslashes (C-style).

@ONLY
    Restrict variable replacement to references of the form @VAR@. This is useful for configuring scripts that use ${VAR} syntax.

NEWLINE_STYLE <style>
    Specify the newline style for the output file. Specify UNIX or LF for \n newlines, or specify DOS, WIN32, or CRLF for \r\n newlines. This option may not be used with COPYONLY.

  Transformations

Variables referenced in the input file content as @VAR@, ${VAR}, $CACHE{VAR}, and environment variables referenced as $ENV{VAR}, will each be replaced with the current value of the variable, or the empty string if the variable is not defined. Furthermore, input lines of the form

    #cmakedefine VAR ...

will be replaced with either

    #define VAR ...

or

    /* #undef VAR */

depending on whether VAR is set in CMake to any value not considered a false constant by the if() command. The "..." content on the line after the variable name, if any, is processed as above.

Unlike lines of the form #cmakedefine VAR ..., in lines of the form #cmakedefine01 VAR, VAR itself will expand to VAR 0 or VAR 1 rather than being assigned the value .... Therefore, input lines of the form

    #cmakedefine01 VAR

will be replaced with either

    #define VAR 0

or

    #define VAR 1

Input lines of the form #cmakedefine01 VAR ... will expand as #cmakedefine01 VAR ... 0 or #cmakedefine01 VAR ... 1, which may lead to undefined behavior.

Added in version 3.10: The result lines (with the exception of the #undef comments) can be indented using spaces and/or tabs between the # character and the cmakedefine or cmakedefine01 words. This whitespace indentation will be preserved in the output lines:

    #  cmakedefine VAR
    #  cmakedefine01 VAR

will be replaced, if VAR is defined, with

    #  define VAR
    #  define VAR 1

  Example

Consider a source tree containing a foo.h.in file:

    #cmakedefine FOO_ENABLE
    #cmakedefine FOO_STRING "@FOO_STRING@"

An adjacent CMakeLists.txt may use configure_file to configure the header:

    option(FOO_ENABLE "Enable Foo" ON)
    if(FOO_ENABLE)
      set(FOO_STRING "foo")
    endif()
    configure_file(foo.h.in foo.h @ONLY)

This creates a foo.h in the build directory corresponding to this source directory. If the FOO_ENABLE option is on, the configured file will contain:

    #define FOO_ENABLE
    #define FOO_STRING "foo"

Otherwise it will contain:

    /* #undef FOO_ENABLE */
    /* #undef FOO_STRING */

One may then use the target_include_directories() command to specify the output directory as an include directory:

    target_include_directories(<target> [SYSTEM] <INTERFACE|PUBLIC|PRIVATE> "${CMAKE_CURRENT_BINARY_DIR}")

so that sources may include the header as #include <foo.h>.

  See Also

•   file(GENERATE)

  continue

Added in version 3.2.

Continue to the top of enclosing foreach or while loop.

    continue()

The continue() command allows a cmake script to abort the rest of the current iteration of a foreach() or while() loop, and start at the top of the next iteration.

See also the break() command.

  else

Starts the else portion of an if block.

    else([<condition>])

See the if() command.

The optional <condition> argument is supported for backward compatibility only and is not evaluated.

  elseif

Starts an elseif portion of an if block.

    elseif(<condition>)

See the if() command, especially for the syntax and logic of the <condition>.

  endblock

Added in version 3.25.

Ends a list of commands in a block() and removes the scopes created by the block() command.

    endblock()

  endforeach

Ends a list of commands in a foreach block.

    endforeach([<loop_var>])

See the foreach() command.

The optional <loop_var> argument is supported for backward compatibility only. If used it must be a verbatim repeat of the <loop_var> argument of the opening foreach clause.

  endfunction

Ends a list of commands in a function block.

    endfunction([<name>])

See the function() command.

The optional <name> argument is supported for backward compatibility only. If used it must be a verbatim repeat of the <name> argument of the opening function command.

  endif

Ends a list of commands in an if block.

    endif([<condition>])

See the if() command.

The optional <condition> argument is supported for backward compatibility only. If used it must be a verbatim repeat of the argument of the opening if clause.

  endmacro

Ends a list of commands in a macro block.

    endmacro([<name>])

See the macro() command.

The optional <name> argument is supported for backward compatibility only. If used it must be a verbatim repeat of the <name> argument of the opening macro command.

  endwhile

Ends a list of commands in a while block.

    endwhile([<condition>])

See the while() command.

The optional <condition> argument is supported for backward compatibility only. If used it must be a verbatim repeat of the argument of the opening while clause.

  execute_process

Execute one or more child processes.

    execute_process(COMMAND <cmd1> [<arguments>]
                    [COMMAND <cmd2> [<arguments>]]...
                    [WORKING_DIRECTORY <directory>]
                    [TIMEOUT <seconds>]
                    [RESULT_VARIABLE <variable>]
                    [RESULTS_VARIABLE <variable>]
                    [OUTPUT_VARIABLE <variable>]
                    [ERROR_VARIABLE <variable>]
                    [INPUT_FILE <file>]
                    [OUTPUT_FILE <file>]
                    [ERROR_FILE <file>]
                    [OUTPUT_QUIET]
                    [ERROR_QUIET]
                    [COMMAND_ECHO <where>]
                    [OUTPUT_STRIP_TRAILING_WHITESPACE]
                    [ERROR_STRIP_TRAILING_WHITESPACE]
                    [ENCODING <name>]
                    [ECHO_OUTPUT_VARIABLE]
                    [ECHO_ERROR_VARIABLE]
                    [COMMAND_ERROR_IS_FATAL <ANY|LAST|NONE>])

Runs the given sequence of one or more commands.

Commands are executed concurrently as a pipeline, with the standard output of each process piped to the standard input of the next. A single standard error pipe is used for all processes.

execute_process runs commands while CMake is configuring the project, prior to build system generation. Use the add_custom_target() and add_custom_command() commands to create custom commands that run at build time.

Options:

COMMAND
    A child process command line.

    CMake executes the child process using operating system APIs directly:

•   On POSIX platforms, the command line is passed to the child process in an argv[] style array. No intermediate shell is executed, so shell operators such as > are treated as normal arguments.

•   On Windows platforms, the command line is encoded as a string such that child processes using CommandLineToArgvW will decode the original arguments.

    If the command runs a .exe, .com, or other executable, no intermediate command interpreter is executed, so shell operators such as > are treated as normal arguments.

    If the command runs a .bat or .cmd script, it is executed through the cmd command interpreter. The command interpreter does not use CommandLineToArgvW, so some arguments may be received by the script with extra quoting.

    Changed in version 4.0: .bat and .cmd scripts are now explicitly executed through the command interpreter by prepending cmd /c call to the command line. Previously, they were implicitly executed through cmd /c, without call, by undocumented behavior of CreateProcessW.

    Use the INPUT_*, OUTPUT_*, and ERROR_* options to redirect stdin, stdout, and stderr.

    For sequential execution of multiple commands use multiple execute_process calls each with a single COMMAND argument.

WORKING_DIRECTORY
    The named directory will be set as the current working directory of the child processes.

TIMEOUT
    After the specified number of seconds (fractions allowed), all unfinished child processes will be terminated, and the RESULT_VARIABLE will be set to a string mentioning the "timeout".

RESULT_VARIABLE
    The variable will be set to contain the result of last child process. This will be an integer return code from the last child or a string describing an error condition.

RESULTS_VARIABLE <variable>
    Added in version 3.10.

    The variable will be set to contain the result of all processes as a semicolon-separated list, in order of the given COMMAND arguments. Each entry will be an integer return code from the corresponding child or a string describing an error condition.

INPUT_FILE <file>
    <file> is attached to the standard input pipe of the first COMMAND process.

OUTPUT_FILE <file>
    <file> is attached to the standard output pipe of the last COMMAND process.

ERROR_FILE <file>
    <file> is attached to the standard error pipe of all COMMAND processes.

    Added in version 3.3: If the same <file> is named for both OUTPUT_FILE and ERROR_FILE then it will be used for both standard output and standard error pipes.

OUTPUT_QUIET, ERROR_QUIET
    The standard output on OUTPUT_VARIABLE or standard error on ERROR_VARIABLE are not connected (no variable content). The *_FILE and ECHO_*_VARIABLE options are not affected.

OUTPUT_VARIABLE, ERROR_VARIABLE
    The variable named will be set with the contents of the standard output and standard error pipes, respectively. If the same variable is named for both pipes their output will be merged in the order produced.

ECHO_OUTPUT_VARIABLE, ECHO_ERROR_VARIABLE
    Added in version 3.18.

    The standard output or standard error will not be exclusively redirected to the specified variables.

    The output will be duplicated into the specified variables and also onto standard output or standard error analogous to the tee Unix command.

    NOTE: If more than one OUTPUT_* or ERROR_* option is given for the same pipe the precedence is not specified. If no OUTPUT_* or ERROR_* options are given the output will be shared with the corresponding pipes of the CMake process itself.

COMMAND_ECHO <where>
    Added in version 3.15.

    The command being run will be echo'ed to <where> with <where> being set to one of STDERR, STDOUT or NONE. See the CMAKE_EXECUTE_PROCESS_COMMAND_ECHO variable for a way to control the default behavior when this option is not present.

ENCODING <name>
    Added in version 3.8.

    On Windows, the encoding that is used to decode output from the process. Ignored on other platforms. Valid encoding names are:

NONE
    Perform no decoding. This assumes that the process output is encoded in the same way as CMake's internal encoding (UTF-8).

    This was the default in CMake 3.14 and older.

AUTO
    Use the current active console's codepage or if that isn't available then use ANSI.

    This was the default in CMake 3.15 through 3.30.

ANSI
    Use the ANSI codepage.

OEM Use the original equipment manufacturer (OEM) code page.

UTF-8
    Added in version 3.11.

    Use the UTF-8 codepage.

    This is the default since CMake 3.31. See policy CMP0176.

UTF8
    Use the UTF-8 codepage. Use of this name is discouraged in favor of UTF-8 to match the UTF-8 RFC naming convention.

COMMAND_ERROR_IS_FATAL <ANY|LAST|NONE>
    Added in version 3.19.

    The option following COMMAND_ERROR_IS_FATAL determines the behavior when an error is encountered:

ANY If any of the commands in the list of commands fail, the execute_process() command halts with an error.

LAST
    If the last command in the list of commands fails, the execute_process() command halts with an error. Commands earlier in the list will not cause a fatal error.

NONE
    Added in version 4.0.

    Regardless of any of the commands failing, the execute_process() command will not halt with an error.

    Added in version 4.0: If not provided, the CMAKE_EXECUTE_PROCESS_COMMAND_ERROR_IS_FATAL variable is checked. If the variable is not set, the default is NONE. If RESULT_VARIABLE or RESULTS_VARIABLE is supplied, CMAKE_EXECUTE_PROCESS_COMMAND_ERROR_IS_FATAL is ignored.

  file

File manipulation command.

This command is dedicated to file and path manipulation requiring access to the filesystem.

For other path manipulation, handling only syntactic aspects, have a look at cmake_path() command.

NOTE: The sub-commands RELATIVE_PATH, TO_CMAKE_PATH and TO_NATIVE_PATH has been superseded, respectively, by sub-commands RELATIVE_PATH, CONVERT ... TO_CMAKE_PATH_LIST and CONVERT ... TO_NATIVE_PATH_LIST of cmake_path() command.

  Synopsis

    Reading
      file(READ <filename> <out-var> [...])
      file(STRINGS <filename> <out-var> [...])
      file(<HASH> <filename> <out-var>)
      file(TIMESTAMP <filename> <out-var> [...])
    Writing
      file({WRITE | APPEND} <filename> <content>...)
      file({TOUCH | TOUCH_NOCREATE} <file>...)
      file(GENERATE OUTPUT <output-file> [...])
      file(CONFIGURE OUTPUT <output-file> CONTENT <content> [...])
    Filesystem
      file({GLOB | GLOB_RECURSE} <out-var> [...] <globbing-expr>...)
      file(MAKE_DIRECTORY <directories>... [...])
      file({REMOVE | REMOVE_RECURSE } <files>...)
      file(RENAME <oldname> <newname> [...])
      file(COPY_FILE <oldname> <newname> [...])
      file({COPY | INSTALL} <file>... DESTINATION <dir> [...])
      file(SIZE <filename> <out-var>)
      file(READ_SYMLINK <linkname> <out-var>)
      file(CREATE_LINK <original> <linkname> [...])
      file(CHMOD <files>... <directories>... PERMISSIONS <permissions>... [...])
      file(CHMOD_RECURSE <files>... <directories>... PERMISSIONS <permissions>... [...])
    Path Conversion
      file(REAL_PATH <path> <out-var> [BASE_DIRECTORY <dir>] [EXPAND_TILDE])
      file(RELATIVE_PATH <out-var> <directory> <file>)
      file({TO_CMAKE_PATH | TO_NATIVE_PATH} <path> <out-var>)
    Transfer
      file(DOWNLOAD <url> [<file>] [...])
      file(UPLOAD <file> <url> [...])
    Locking
      file(LOCK <path> [...])
    Archiving
      file(ARCHIVE_CREATE OUTPUT <archive> PATHS <paths>... [...])
      file(ARCHIVE_EXTRACT INPUT <archive> [...])
    Handling Runtime Binaries
      file(GET_RUNTIME_DEPENDENCIES [...])

  Reading

file(READ <filename> <variable> [OFFSET <offset>] [LIMIT <max-in>] [HEX])
    Read content from a file called <filename> and store it in a <variable>. Optionally start from the given <offset> and read at most <max-in> bytes. The HEX option causes data to be converted to a hexadecimal representation (useful for binary data). If the HEX option is specified, letters in the output (a through f) are in lowercase.

file(STRINGS <filename> <variable> <options>...)
    Parse a list of ASCII strings from <filename> and store it in <variable>. Binary data in the file are ignored. Carriage return (\r, CR) characters are ignored. The options are:

LENGTH_MAXIMUM <max-len>
    Consider only strings of at most a given length.

LENGTH_MINIMUM <min-len>
    Consider only strings of at least a given length.

LIMIT_COUNT <max-num>
    Limit the number of distinct strings to be extracted.

LIMIT_INPUT <max-in>
    Limit the number of input bytes to read from the file.

LIMIT_OUTPUT <max-out>
    Limit the number of total bytes to store in the <variable>.

NEWLINE_CONSUME
    Treat newline characters (\n, LF) as part of string content instead of terminating at them.

NO_HEX_CONVERSION
    Intel Hex and Motorola S-record files are automatically converted to binary while reading unless this option is given.

REGEX <regex>
    Consider only strings that match the given regular expression, as described under string(REGEX).

    Changed in version 3.29: Capture groups from the last match in the file are stored in CMAKE_MATCH_<n>, similar to string(REGEX MATCHALL). See policy CMP0159.

ENCODING <encoding-type>
    Added in version 3.1.

    Consider strings of a given encoding. Currently supported encodings are: UTF-8, UTF-16LE, UTF-16BE, UTF-32LE, UTF-32BE. If the ENCODING option is not provided and the file has a Byte Order Mark, the ENCODING option will be defaulted to respect the Byte Order Mark.

    Added in version 3.2: Added the UTF-16LE, UTF-16BE, UTF-32LE, UTF-32BE encodings.

    For example, the code

        file(STRINGS myfile.txt myfile)

    stores a list in the variable myfile in which each item is a line from the input file.

file(<HASH> <filename> <variable>)
    Compute a cryptographic hash of the content of <filename> and store it in a <variable>. The supported <HASH> algorithm names are those listed by the string(<HASH>) command.

file(TIMESTAMP <filename> <variable> [<format>] [UTC])
    Compute a string representation of the modification time of <filename> and store it in <variable>. Should the command be unable to obtain a timestamp variable will be set to the empty string ("").

    See the string(TIMESTAMP) command for documentation of the <format> and UTC options.

  Writing

file(WRITE <filename> <content>...)

file(APPEND <filename> <content>...)
    Write <content> into a file called <filename>. If the file does not exist, it will be created. If the file already exists, WRITE mode will overwrite it and APPEND mode will append to the end. Any directories in the path specified by <filename> that do not exist will be created.

    If the file is a build input, use the configure_file() command to update the file only when its content changes.

file(TOUCH <files>...)

file(TOUCH_NOCREATE <files>...)
    Added in version 3.12.

    Create a file with no content if it does not yet exist. If the file already exists, its access and/or modification will be updated to the time when the function call is executed.

    Use TOUCH_NOCREATE to touch a file if it exists but not create it. If a file does not exist it will be silently ignored.

    With TOUCH and TOUCH_NOCREATE, the contents of an existing file will not be modified.

    Changed in version 3.30: <files> can be an empty list. CMake 3.29 and earlier required at least one file to be given.

file(GENERATE [...])
    Generate an output file for each build configuration supported by the current CMake Generator. Evaluate generator expressions from the input content to produce the output content.

        file(GENERATE OUTPUT <output-file>
             <INPUT <input-file>|CONTENT <content>>
             [CONDITION <expression>] [TARGET <target>]
             [NO_SOURCE_PERMISSIONS | USE_SOURCE_PERMISSIONS |
              FILE_PERMISSIONS <permissions>...]
             [NEWLINE_STYLE [UNIX|DOS|WIN32|LF|CRLF]])

    The options are:

CONDITION <condition>
    Generate the output file for a particular configuration only if the condition is true. The condition must be either 0 or 1 after evaluating generator expressions.

CONTENT <content>
    Use the content given explicitly as input.

INPUT <input-file>
    Use the content from a given file as input.

    Changed in version 3.10: A relative path is treated with respect to the value of CMAKE_CURRENT_SOURCE_DIR. See policy CMP0070.

OUTPUT <output-file>
    Specify the output file name to generate. Use generator expressions such as $<CONFIG> to specify a configuration-specific output file name. Multiple configurations may generate the same output file only if the generated content is identical. Otherwise, the <output-file> must evaluate to an unique name for each configuration.

    Changed in version 3.10: A relative path (after evaluating generator expressions) is treated with respect to the value of CMAKE_CURRENT_BINARY_DIR. See policy CMP0070.

TARGET <target>
    Added in version 3.19.

    Specify which target to use when evaluating generator expressions that require a target for evaluation (e.g. $<COMPILE_FEATURES:...>, $<TARGET_PROPERTY:prop>).

NO_SOURCE_PERMISSIONS
    Added in version 3.20.

    The generated file permissions default to the standard 644 value (-rw-r--r--).

USE_SOURCE_PERMISSIONS
    Added in version 3.20.

    Transfer the file permissions of the INPUT file to the generated file. This is already the default behavior if none of the three permissions-related keywords are given (NO_SOURCE_PERMISSIONS, USE_SOURCE_PERMISSIONS or FILE_PERMISSIONS). The USE_SOURCE_PERMISSIONS keyword mostly serves as a way of making the intended behavior clearer at the call site. It is an error to specify this option without INPUT.

FILE_PERMISSIONS <permissions>...
    Added in version 3.20.

    Use the specified permissions for the generated file.

NEWLINE_STYLE <style>
    Added in version 3.20.

    Specify the newline style for the generated file. Specify UNIX or LF for \n newlines, or specify DOS, WIN32, or CRLF for \r\n newlines.

    Exactly one CONTENT or INPUT option must be given. A specific OUTPUT file may be named by at most one invocation of file(GENERATE). Generated files are modified and their timestamp updated on subsequent cmake runs only if their content is changed.

    Note also that file(GENERATE) does not create the output file until the generation phase. The output file will not yet have been written when the file(GENERATE) command returns, it is written only after processing all of a project's CMakeLists.txt files.

file(CONFIGURE OUTPUT <output-file> CONTENT <content> [ESCAPE_QUOTES] [@ONLY] [NEWLINE_STYLE [UNIX|DOS|WIN32|LF|CRLF]])
    Added in version 3.18.

    Generate an output file using the input given by CONTENT and substitute variable values referenced as @VAR@ or ${VAR} contained therein. The substitution rules behave the same as the configure_file() command. In order to match configure_file()'s behavior, generator expressions are not supported for both OUTPUT and CONTENT, and the output file is only modified and its timestamp updated if the content is changed or the file previously didn't exist.

    The arguments are:

OUTPUT <output-file>
    Specify the output file name to generate. A relative path is treated with respect to the value of CMAKE_CURRENT_BINARY_DIR. <output-file> does not support generator expressions.

CONTENT <content>
    Use the content given explicitly as input. <content> does not support generator expressions.

ESCAPE_QUOTES
    Escape any substituted quotes with backslashes (C-style).

@ONLY
    Restrict variable replacement to references of the form @VAR@. This is useful for configuring scripts that use ${VAR} syntax.

NEWLINE_STYLE <style>
    Specify the newline style for the output file. Specify UNIX or LF for \n newlines, or specify DOS, WIN32, or CRLF for \r\n newlines.

  Filesystem

file(GLOB <variable> [LIST_DIRECTORIES true|false] [RELATIVE <path>] [CONFIGURE_DEPENDS] <globbing-expressions>...)

file(GLOB_RECURSE <variable> [FOLLOW_SYMLINKS] [LIST_DIRECTORIES true|false] [RELATIVE <path>] [CONFIGURE_DEPENDS] <globbing-expressions>...)
    Generate a list of files that match the <globbing-expressions> and store it into the <variable>. Globbing expressions are similar to regular expressions, but much simpler. If RELATIVE flag is specified, the results will be returned as relative paths to the given path.

    Changed in version 3.6: The results will be ordered lexicographically.

    On Windows and macOS, globbing is case-insensitive even if the underlying filesystem is case-sensitive (both filenames and globbing expressions are converted to lowercase before matching). On other platforms, globbing is case-sensitive.

    Added in version 3.3: By default GLOB lists directories. Directories are omitted in the result if LIST_DIRECTORIES is set to false.

    Added in version 3.12: If the CONFIGURE_DEPENDS flag is specified, CMake will add logic to the main build system check target to rerun the flagged GLOB commands at build time. If any of the outputs change, CMake will regenerate the build system.

    NOTE: We do not recommend using GLOB to collect a list of source files from your source tree. If no CMakeLists.txt file changes when a source is added or removed then the generated build system cannot know when to ask CMake to regenerate. The CONFIGURE_DEPENDS flag may not work reliably on all generators, or if a new generator is added in the future that cannot support it, projects using it will be stuck. Even if CONFIGURE_DEPENDS works reliably, there is still a cost to perform the check on every rebuild.

    Examples of globbing expressions include:
    *.cxx | match all files with extension cxx
    *.vt? | match all files with extension vta, ..., vtz
    f[3-5].txt | match files f3.txt, f4.txt, f5.txt

    The GLOB_RECURSE mode will traverse all the subdirectories of the matched directory and match the files. Subdirectories that are symlinks are only traversed if FOLLOW_SYMLINKS is given or policy CMP0009 is not set to NEW.

    Added in version 3.3: By default GLOB_RECURSE omits directories from result list. Setting LIST_DIRECTORIES to true adds directories to result list. If FOLLOW_SYMLINKS is given or policy CMP0009 is not set to NEW then LIST_DIRECTORIES treats symlinks as directories.

    Examples of recursive globbing include:
    /dir/*.py | match all python files in /dir and subdirectories

file(MAKE_DIRECTORY <directories>... [RESULT <result>])
    Create the given directories and their parents as needed. Relative input paths are evaluated with respect to the current source directory.

    The options are:

RESULT <result>
    Added in version 3.31.

    Set <result> variable to 0 on success or an error message otherwise. If RESULT is not specified and the operation fails, an error is emitted.

    Changed in version 3.30: <directories> can be an empty list. CMake 3.29 and earlier required at least one directory to be given.

file(REMOVE <files>...)

file(REMOVE_RECURSE <files>...)
    Remove the given files. The REMOVE_RECURSE mode will remove the given files and directories, including non-empty directories. No error is emitted if a given file does not exist. Relative input paths are evaluated with respect to the current source directory.

    Changed in version 3.15: Empty input paths are ignored with a warning. Previous versions of CMake interpreted empty strings as a relative path with respect to the current directory and removed its contents.

file(RENAME <oldname> <newname> [RESULT <result>] [NO_REPLACE])
    Move a file or directory within a filesystem from <oldname> to <newname>, replacing the destination atomically.

    The options are:

RESULT <result>
    Added in version 3.21.

    Set <result> variable to 0 on success or an error message otherwise. If RESULT is not specified and the operation fails, an error is emitted.

NO_REPLACE
    Added in version 3.21.

    If the <newname> path already exists, do not replace it. If RESULT <result> is used, the result variable will be set to NO_REPLACE. Otherwise, an error is emitted.

file(COPY_FILE <oldname> <newname> [RESULT <result>] [ONLY_IF_DIFFERENT] [INPUT_MAY_BE_RECENT])
    Added in version 3.21.

    Copy a file from <oldname> to <newname>. Directories are not supported. Symlinks are ignored and <oldfile>'s content is read and written to <newname> as a new file.

    The options are:

RESULT <result>
    Set <result> variable to 0 on success or an error message otherwise. If RESULT is not specified and the operation fails, an error is emitted.

ONLY_IF_DIFFERENT
    If the <newname> path already exists, do not replace it if the file's contents are already the same as <oldname> (this avoids updating <newname>'s timestamp).

INPUT_MAY_BE_RECENT
    Added in version 3.26.

    Tell CMake that the input file may have been recently created. This is meaningful only on Windows, where files may be inaccessible for a short time after they are created. With this option, if permission is denied, CMake will retry reading the input a few times.

    This sub-command has some similarities to configure_file() with the COPYONLY option. An important difference is that configure_file() creates a dependency on the source file, so CMake will be re-run if it changes. The file(COPY_FILE) sub-command does not create such a dependency.

    See also the file(COPY) sub-command just below which provides further file-copying capabilities.

file(COPY [...])

file(INSTALL [...])
    The COPY signature copies files, directories, and symlinks to a destination folder. Relative input paths are evaluated with respect to the current source directory, and a relative destination is evaluated with respect to the current build directory. Copying preserves input file timestamps, and optimizes out a file if it exists at the destination with the same timestamp. Copying preserves input permissions unless explicit permissions or NO_SOURCE_PERMISSIONS are given (default is USE_SOURCE_PERMISSIONS).

        file(<COPY|INSTALL> <files>... DESTINATION <dir>
             [NO_SOURCE_PERMISSIONS | USE_SOURCE_PERMISSIONS]
             [FILE_PERMISSIONS <permissions>...]
             [DIRECTORY_PERMISSIONS <permissions>...]
             [FOLLOW_SYMLINK_CHAIN]
             [FILES_MATCHING]
             [[PATTERN <pattern> | REGEX <regex>]
              [EXCLUDE] [PERMISSIONS <permissions>...]] [...])

    NOTE: For a simple file copying operation, the file(COPY_FILE) sub-command just above may be easier to use.

    Added in version 3.15: If FOLLOW_SYMLINK_CHAIN is specified, COPY will recursively resolve the symlinks at the paths given until a real file is found, and install a corresponding symlink in the destination for each symlink encountered. For each symlink that is installed, the resolution is stripped of the directory, leaving only the filename, meaning that the new symlink points to a file in the same directory as the symlink. This feature is useful on some Unix systems, where libraries are installed as a chain of symlinks with version numbers, with less specific versions pointing to more specific versions. FOLLOW_SYMLINK_CHAIN will install all of these symlinks and the library itself into the destination directory. For example, if you have the following directory structure:

•   /opt/foo/lib/libfoo.so.1.2.3

•   /opt/foo/lib/libfoo.so.1.2 -> libfoo.so.1.2.3

•   /opt/foo/lib/libfoo.so.1 -> libfoo.so.1.2

•   /opt/foo/lib/libfoo.so -> libfoo.so.1

    and you do:

        file(COPY /opt/foo/lib/libfoo.so DESTINATION lib FOLLOW_SYMLINK_CHAIN)

    This will install all of the symlinks and libfoo.so.1.2.3 itself into lib.

    See the install(DIRECTORY) command for documentation of permissions, FILES_MATCHING, PATTERN, REGEX, and EXCLUDE options. Copying directories preserves the structure of their content even if options are used to select a subset of files.

    The INSTALL signature differs slightly from COPY: it prints status messages, and NO_SOURCE_PERMISSIONS is default. Installation scripts generated by the install() command use this signature (with some undocumented options for internal use).

    Changed in version 3.22: The environment variable CMAKE_INSTALL_MODE can override the default copying behavior of file(INSTALL).

file(SIZE <filename> <variable>)
    Added in version 3.14.

    Determine the file size of the <filename> and put the result in <variable> variable. Requires that <filename> is a valid path pointing to a file and is readable.

file(READ_SYMLINK <linkname> <variable>)
    Added in version 3.14.

    Query the symlink <linkname> and stores the path it points to in the result <variable>. If <linkname> does not exist or is not a symlink, CMake issues a fatal error.

    Note that this command returns the raw symlink path and does not resolve a relative path. The following is an example of how to ensure that an absolute path is obtained:

        set(linkname "/path/to/foo.sym")
        file(READ_SYMLINK "${linkname}" result)
        if(NOT IS_ABSOLUTE "${result}")
          get_filename_component(dir "${linkname}" DIRECTORY)
          set(result "${dir}/${result}")
        endif()

file(CREATE_LINK <original> <linkname> [RESULT <result>] [COPY_ON_ERROR] [SYMBOLIC])
    Added in version 3.14.

    Create a link <linkname> that points to <original>. It will be a hard link by default, but providing the SYMBOLIC option results in a symbolic link instead. Hard links require that original exists and is a file, not a directory. If <linkname> already exists, it will be overwritten.

    The <result> variable, if specified, receives the status of the operation. It is set to 0 upon success or an error message otherwise. If RESULT is not specified and the operation fails, a fatal error is emitted.

    Specifying COPY_ON_ERROR enables copying the file as a fallback if creating the link fails. It can be useful for handling situations such as <original> and <linkname> being on different drives or mount points, which would make them unable to support a hard link.

file(CHMOD <files>... <directories>... [PERMISSIONS <permissions>...] [FILE_PERMISSIONS <permissions>...] [DIRECTORY_PERMISSIONS <permissions>...])
    Added in version 3.19.

    Set the permissions for the <files>... and <directories>... specified. Valid permissions are OWNER_READ, OWNER_WRITE, OWNER_EXECUTE, GROUP_READ, GROUP_WRITE, GROUP_EXECUTE, WORLD_READ, WORLD_WRITE, WORLD_EXECUTE, SETUID, SETGID.

    Valid combination of keywords are:

PERMISSIONS
    All items are changed.

FILE_PERMISSIONS
    Only files are changed.

DIRECTORY_PERMISSIONS
    Only directories are changed.

PERMISSIONS and FILE_PERMISSIONS
    FILE_PERMISSIONS overrides PERMISSIONS for files.

PERMISSIONS and DIRECTORY_PERMISSIONS
    DIRECTORY_PERMISSIONS overrides PERMISSIONS for directories.

FILE_PERMISSIONS and DIRECTORY_PERMISSIONS
    Use FILE_PERMISSIONS for files and DIRECTORY_PERMISSIONS for directories.

file(CHMOD_RECURSE <files>... <directories>... [PERMISSIONS <permissions>...] [FILE_PERMISSIONS <permissions>...] [DIRECTORY_PERMISSIONS <permissions>...])
    Added in version 3.19.

    Same as CHMOD, but change the permissions of files and directories present in the <directories>... recursively.

  Path Conversion

file(REAL_PATH <path> <out-var> [BASE_DIRECTORY <dir>] [EXPAND_TILDE])
    Added in version 3.19.

    Compute the absolute path to an existing file or directory with symlinks resolved. The options are:

BASE_DIRECTORY <dir>
    If the provided <path> is a relative path, it is evaluated relative to the given base directory <dir>. If no base directory is provided, the default base directory will be CMAKE_CURRENT_SOURCE_DIR.

EXPAND_TILDE
    Added in version 3.21.

    If the <path> is ~ or starts with ~/, the ~ is replaced by the user's home directory. The path to the home directory is obtained from environment variables. On Windows, the USERPROFILE environment variable is used, falling back to the HOME environment variable if USERPROFILE is not defined. On all other platforms, only HOME is used.

    Changed in version 3.28: All symlinks are resolved before collapsing ../ components. See policy CMP0152.

file(RELATIVE_PATH <variable> <directory> <file>)
    Compute the relative path from a <directory> to a <file> and store it in the <variable>.

file(TO_CMAKE_PATH "<path>" <variable>)

file(TO_NATIVE_PATH "<path>" <variable>)
    The TO_CMAKE_PATH mode converts a native <path> into a cmake-style path with forward-slashes (/). The input can be a single path or a system search path like $ENV{PATH}. A search path will be converted to a cmake-style list separated by ; characters.

    The TO_NATIVE_PATH mode converts a cmake-style <path> into a native path with platform-specific slashes (\ on Windows hosts and / elsewhere).

    Always use double quotes around the <path> to be sure it is treated as a single argument to this command.

  Transfer

file(DOWNLOAD <url> [<file>] <options>...)

file(UPLOAD <file> <url> <options>...)
    The DOWNLOAD subcommand downloads the given <url> to a local <file>. The UPLOAD mode uploads a local <file> to a given <url>.

    Added in version 3.19: If <file> is not specified for file(DOWNLOAD), the file is not saved. This can be useful if you want to know if a file can be downloaded (for example, to check that it exists) without actually saving it anywhere.

    Options to both DOWNLOAD and UPLOAD are:

INACTIVITY_TIMEOUT <seconds>
    Terminate the operation after a period of inactivity.

LOG <variable>
    Store a human-readable log of the operation in a variable.

SHOW_PROGRESS
    Print progress information as status messages until the operation is complete.

STATUS <variable>
    Store the resulting status of the operation in a variable. The status is a ; separated list of length 2. The first element is the numeric return value for the operation, and the second element is a string value for the error. A 0 numeric error means no error in the operation.

TIMEOUT <seconds>
    Terminate the operation after a given total time has elapsed.

USERPWD <username>:<password>
    Added in version 3.7.

    Set username and password for operation.

HTTPHEADER <HTTP-header>
    Added in version 3.7.

    HTTP header for DOWNLOAD and UPLOAD operations. HTTPHEADER can be repeated for multiple options:

        file(DOWNLOAD <url>
             HTTPHEADER "Authorization: Bearer <auth-token>"
             HTTPHEADER "UserAgent: Mozilla/5.0")

NETRC <level>
    Added in version 3.11.

    Specify whether the .netrc file is to be used for operation. If this option is not specified, the value of the CMAKE_NETRC variable will be used instead.

    Valid levels are:

IGNORED
    The .netrc file is ignored. This is the default.

OPTIONAL
    The .netrc file is optional, and information in the URL is preferred. The file will be scanned to find which ever information is not specified in the URL.

REQUIRED
    The .netrc file is required, and information in the URL is ignored.

NETRC_FILE <file>
    Added in version 3.11.

    Specify an alternative .netrc file to the one in your home directory, if the NETRC level is OPTIONAL or REQUIRED. If this option is not specified, the value of the CMAKE_NETRC_FILE variable will be used instead.

TLS_VERSION <min>
    Added in version 3.30.

    Specify minimum TLS version for https:// URLs. If this option is not specified, the value of the CMAKE_TLS_VERSION variable or CMAKE_TLS_VERSION environment variable will be used instead. See CMAKE_TLS_VERSION for allowed values.

    Changed in version 3.31: The default is TLS 1.2. Previously, no minimum version was enforced by default.

TLS_VERIFY <ON|OFF>
    Specify whether to verify the server certificate for https:// URLs. If this option is not specified, the value of the CMAKE_TLS_VERIFY variable or CMAKE_TLS_VERIFY environment variable will be used instead. If neither is set, the default is on.

    Changed in version 3.31: The default is on. Previously, the default was off. Users may set the CMAKE_TLS_VERIFY environment variable to 0 to restore the old default.

    Added in version 3.18: Added support to file(UPLOAD).

TLS_CAINFO <file>
    Specify a custom Certificate Authority file for https:// URLs. If this option is not specified, the value of the CMAKE_TLS_CAINFO variable will be used instead.

    Added in version 3.18: Added support to file(UPLOAD).

    For https:// URLs CMake must be built with SSL/TLS support.

    Additional options to DOWNLOAD are:

EXPECTED_HASH <algorithm>=<value>
    Verify that the downloaded content hash matches the expected value, where <algorithm> is one of the algorithms supported by <HASH>. If the file already exists and matches the hash, the download is skipped. If the file already exists and does not match the hash, the file is downloaded again. If after download the file does not match the hash, the operation fails with an error. It is an error to specify this option if DOWNLOAD is not given a <file>.

EXPECTED_MD5 <value>
    Historical short-hand for EXPECTED_HASH MD5=<value>. It is an error to specify this if DOWNLOAD is not given a <file>.

RANGE_START <value>
    Added in version 3.24.

    Offset of the start of the range in file in bytes. Could be omitted to download up to the specified RANGE_END.

RANGE_END <value>
    Added in version 3.24.

    Offset of the end of the range in file in bytes. Could be omitted to download everything from the specified RANGE_START to the end of file.

  Locking

file(LOCK <path> [DIRECTORY] [RELEASE] [GUARD <FUNCTION|FILE|PROCESS>] [RESULT_VARIABLE <variable>] [TIMEOUT <seconds>])
    Added in version 3.2.

    Lock a file specified by <path> if no DIRECTORY option present and file <path>/cmake.lock otherwise. The file will be locked for the scope defined by the GUARD option (default value is PROCESS). The RELEASE option can be used to unlock the file explicitly. If the TIMEOUT option is not specified, CMake will wait until the lock succeeds or until a fatal error occurs. If TIMEOUT is set to 0, locking will be tried once and the result will be reported immediately. If TIMEOUT is not 0, CMake will try to lock the file for the period specified by the TIMEOUT <seconds> value. Any errors will be interpreted as fatal if there is no RESULT_VARIABLE option. Otherwise, the result will be stored in <variable> and will be 0 on success or an error message on failure.

    Note that lock is advisory; there is no guarantee that other processes will respect this lock, i.e. lock synchronize two or more CMake instances sharing some modifiable resources. Similar logic applies to the DIRECTORY option; locking a parent directory doesn't prevent other LOCK commands from locking any child directory or file.

    Trying to lock the same file twice is not allowed. Any intermediate directories and the file itself will be created if they not exist. The GUARD and TIMEOUT options are ignored on the RELEASE operation.

  Archiving

file(ARCHIVE_CREATE OUTPUT <archive> PATHS <paths>... [FORMAT <format>] [COMPRESSION <compression> [COMPRESSION_LEVEL <compression-level>]] [MTIME <mtime>] [WORKING_DIRECTORY <dir>] [VERBOSE])
    Added in version 3.18.

    Creates the specified <archive> file with the files and directories listed in <paths>. Note that <paths> must list actual files or directories; wildcards are not supported.

    The options are:

FORMAT <format>
    Specify the archive format. Supported values for <format> are 7zip, gnutar, pax, paxr, raw and zip. If FORMAT is not given, the default format is paxr.

COMPRESSION <compression>
    Some archive formats allow the type of compression to be specified. The 7zip and zip archive formats already imply a specific type of compression. The other formats use no compression by default, but can be directed to do so with the COMPRESSION option. Valid values for <compression> are None, BZip2, GZip, XZ, and Zstd.

    NOTE: With FORMAT set to raw, only one file will be compressed with the compression type specified by COMPRESSION.

COMPRESSION_LEVEL <compression-level>
    Added in version 3.19.

    The compression level can be specified with the COMPRESSION_LEVEL option. The <compression-level> should be between 0-9, with the default being 0. The COMPRESSION option must be present when COMPRESSION_LEVEL is given.

    Added in version 3.26: The <compression-level> of the Zstd algorithm can be set between 0-19.

MTIME <mtime>
    Specify the modification time recorded in tarball entries.

WORKING_DIRECTORY <dir>
    Added in version 3.31.

    Specify the directory in which the archive creation operation will be executed. Paths in the <paths> argument can be relative to this directory. If this option is not provided, the current working directory will be used by default.

VERBOSE
    Enable verbose output from the archive operation.

file(ARCHIVE_EXTRACT INPUT <archive> [DESTINATION <dir>] [PATTERNS <pattern>...] [LIST_ONLY] [VERBOSE] [TOUCH])
    Added in version 3.18.

    Extracts or lists the content of the specified <archive>.

    The options are:

DESTINATION <dir>
    Specify the directory under which the content of the archive will be extracted. If the directory does not exist, it will be created. If DESTINATION is not given, the current binary directory will be used.

PATTERNS <pattern>...
    Extract/list only files and directories that match one of the given patterns. Wildcards are supported. If the PATTERNS option is not given, the entire archive will be listed or extracted.

LIST_ONLY
    List the files in the archive rather than extract them.

TOUCH
    Added in version 3.24.

    Give extracted files a current local timestamp instead of extracting file timestamps from the archive.

VERBOSE
    Enable verbose output from the extraction operation.

    NOTE: The working directory for this subcommand is the DESTINATION directory (provided or computed) except when LIST_ONLY is specified. Therefore, outside of script mode, it may be best to provide absolute paths to INPUT archives as they are unlikely to be extracted where a relative path works.

  Handling Runtime Binaries

file(GET_RUNTIME_DEPENDENCIES [...])
    Added in version 3.16.

    Recursively get the list of libraries depended on by the given files:

        file(GET_RUNTIME_DEPENDENCIES
          [RESOLVED_DEPENDENCIES_VAR <deps_var>]
          [UNRESOLVED_DEPENDENCIES_VAR <unresolved_deps_var>]
          [CONFLICTING_DEPENDENCIES_PREFIX <conflicting_deps_prefix>]
          [EXECUTABLES <executable_files>...]
          [LIBRARIES <library_files>...]
          [MODULES <module_files>...]
          [DIRECTORIES <directories>...]
          [BUNDLE_EXECUTABLE <bundle_executable_file>]
          [PRE_INCLUDE_REGEXES <regexes>...]
          [PRE_EXCLUDE_REGEXES <regexes>...]
          [POST_INCLUDE_REGEXES <regexes>...]
          [POST_EXCLUDE_REGEXES <regexes>...]
          [POST_INCLUDE_FILES <files>...]
          [POST_EXCLUDE_FILES <files>...]
          )

    Please note that this sub-command is not intended to be used in project mode. It is intended for use at install time, either from code generated by the install(RUNTIME_DEPENDENCY_SET) command, or from code provided by the project via install(CODE) or install(SCRIPT). For example:

        install(CODE [[
          file(GET_RUNTIME_DEPENDENCIES
            # ...
            )
          ]])

    The arguments are as follows:

RESOLVED_DEPENDENCIES_VAR <deps_var>
    Name of the variable in which to store the list of resolved dependencies.

UNRESOLVED_DEPENDENCIES_VAR <unresolved_deps_var>
    Name of the variable in which to store the list of unresolved dependencies. If this variable is not specified, and there are any unresolved dependencies, an error is issued.

CONFLICTING_DEPENDENCIES_PREFIX <conflicting_deps_prefix>
    Variable prefix in which to store conflicting dependency information. Dependencies are conflicting if two files with the same name are found in two different directories. The list of filenames that conflict are stored in <conflicting_deps_prefix>_FILENAMES. For each filename, the list of paths that were found for that filename are stored in <conflicting_deps_prefix>_<filename>.

EXECUTABLES <executable_files>...
    List of executable files to read for dependencies. These are executables that are typically created with add_executable(), but they do not have to be created by CMake. On Apple platforms, the paths to these files determine the value of @executable_path when recursively resolving the libraries. Specifying any kind of library (STATIC, MODULE, or SHARED) here will result in undefined behavior.

LIBRARIES <library_files>...
    List of library files to read for dependencies. These are libraries that are typically created with add_library(SHARED), but they do not have to be created by CMake. Specifying STATIC libraries, MODULE libraries, or executables here will result in undefined behavior.

MODULES <module_files>...
    List of loadable module files to read for dependencies. These are modules that are typically created with add_library(MODULE), but they do not have to be created by CMake. They are typically used by calling dlopen() at runtime rather than linked at link time with ld -l. Specifying STATIC libraries, SHARED libraries, or executables here will result in undefined behavior.

DIRECTORIES <directories>...
    List of additional directories to search for dependencies. On Linux platforms, these directories are searched if the dependency is not found in any of the other usual paths. If it is found in such a directory, a warning is issued, because it means that the file is incomplete (it does not list all of the directories that contain its dependencies). On Windows platforms, these directories are searched if the dependency is not found in any of the other search paths, but no warning is issued, because searching other paths is a normal part of Windows dependency resolution. On Apple platforms, this argument has no effect.

BUNDLE_EXECUTABLE <bundle_executable_file>
    Executable to treat as the "bundle executable" when resolving libraries. On Apple platforms, this argument determines the value of @executable_path when recursively resolving libraries for LIBRARIES and MODULES files. It has no effect on EXECUTABLES files. On other platforms, it has no effect. This is typically (but not always) one of the executables in the EXECUTABLES argument which designates the "main" executable of the package.

    The following arguments specify filters for including or excluding libraries to be resolved. See below for a full description of how they work.

PRE_INCLUDE_REGEXES <regexes>...
    List of pre-include regexes through which to filter the names of not-yet-resolved dependencies.

PRE_EXCLUDE_REGEXES <regexes>...
    List of pre-exclude regexes through which to filter the names of not-yet-resolved dependencies.

POST_INCLUDE_REGEXES <regexes>...
    List of post-include regexes through which to filter the names of resolved dependencies.

POST_EXCLUDE_REGEXES <regexes>...
    List of post-exclude regexes through which to filter the names of resolved dependencies.

POST_INCLUDE_FILES <files>...
    Added in version 3.21.

    List of post-include filenames through which to filter the names of resolved dependencies. Symlinks are resolved when attempting to match these filenames.

POST_EXCLUDE_FILES <files>...
    Added in version 3.21.

    List of post-exclude filenames through which to filter the names of resolved dependencies. Symlinks are resolved when attempting to match these filenames.

    These arguments can be used to exclude unwanted system libraries when resolving the dependencies, or to include libraries from a specific directory. The filtering works as follows:

1.  If the not-yet-resolved dependency matches any of the PRE_INCLUDE_REGEXES, steps 2 and 3 are skipped, and the dependency resolution proceeds to step 4.

2.  If the not-yet-resolved dependency matches any of the PRE_EXCLUDE_REGEXES, dependency resolution stops for that dependency.

3.  Otherwise, dependency resolution proceeds.

4.  file(GET_RUNTIME_DEPENDENCIES) searches for the dependency according to the linking rules of the platform (see below).

5.  If the dependency is found, and its full path matches one of the POST_INCLUDE_REGEXES or POST_INCLUDE_FILES, the full path is added to the resolved dependencies, and file(GET_RUNTIME_DEPENDENCIES) recursively resolves that library's own dependencies. Otherwise, resolution proceeds to step 6.

6.  If the dependency is found, but its full path matches one of the POST_EXCLUDE_REGEXES or POST_EXCLUDE_FILES, it is not added to the resolved dependencies, and dependency resolution stops for that dependency.

7.  If the dependency is found, and its full path does not match either POST_INCLUDE_REGEXES, POST_INCLUDE_FILES, POST_EXCLUDE_REGEXES, or POST_EXCLUDE_FILES, the full path is added to the resolved dependencies, and file(GET_RUNTIME_DEPENDENCIES) recursively resolves that library's own dependencies.

    Different platforms have different rules for how dependencies are resolved. These specifics are described here.

    On Linux platforms, library resolution works as follows:

1.  If the depending file does not have any RUNPATH entries, and the library exists in one of the depending file's RPATH entries, or its parents', in that order, the dependency is resolved to that file.

2.  Otherwise, if the depending file has any RUNPATH entries, and the library exists in one of those entries, the dependency is resolved to that file.

3.  Otherwise, if the library exists in one of the directories listed by ldconfig, the dependency is resolved to that file.

4.  Otherwise, if the library exists in one of the DIRECTORIES entries, the dependency is resolved to that file. In this case, a warning is issued, because finding a file in one of the DIRECTORIES means that the depending file is not complete (it does not list all the directories from which it pulls dependencies).

5.  Otherwise, the dependency is unresolved.

    Changed in version 3.31: Resolution of each encountered library file name occurs at most once while processing a given root ELF file (executable or shared object). If a library file name is encountered again in the dependency tree, the original resolution is assumed. This behavior more closely matches the dynamic loader's behavior on Linux.

    On Windows platforms, library resolution works as follows:

1.  DLL dependency names are converted to lowercase for matching filters. Windows DLL names are case-insensitive, and some linkers mangle the case of the DLL dependency names. However, this makes it more difficult for PRE_INCLUDE_REGEXES, PRE_EXCLUDE_REGEXES, POST_INCLUDE_REGEXES, and POST_EXCLUDE_REGEXES to properly filter DLL names - every regex would have to check for both uppercase and lowercase letters. For example:

        file(GET_RUNTIME_DEPENDENCIES
          # ...
          PRE_INCLUDE_REGEXES "^[Mm][Yy][Ll][Ii][Bb][Rr][Aa][Rr][Yy]\\.[Dd][Ll][Ll]$"
          )

    Converting the DLL name to lowercase allows the regexes to only match lowercase names, thus simplifying the regex. For example:

        file(GET_RUNTIME_DEPENDENCIES
          # ...
          PRE_INCLUDE_REGEXES "^mylibrary\\.dll$"
          )

    This regex will match mylibrary.dll regardless of how it is cased, either on disk or in the depending file. (For example, it will match mylibrary.dll, MyLibrary.dll, and MYLIBRARY.DLL.)

    Changed in version 3.27: The conversion to lowercase only applies while matching filters. Results reported after filtering case-preserve each DLL name as it is found on disk, if resolved, and otherwise as it is referenced by the dependent binary.

    Prior to CMake 3.27, the results were reported with lowercase DLL file names, but the directory portion retained its casing.

2.  (Not yet implemented) If the depending file is a Windows Store app, and the dependency is listed as a dependency in the application's package manifest, the dependency is resolved to that file.

3.  Otherwise, if the library exists in the same directory as the depending file, the dependency is resolved to that file.

4.  Otherwise, if the library exists in either the operating system's system32 directory or the Windows directory, in that order, the dependency is resolved to that file.

5.  Otherwise, if the library exists in one of the directories specified by DIRECTORIES, in the order they are listed, the dependency is resolved to that file. In this case, a warning is not issued, because searching other directories is a normal part of Windows library resolution.

6.  Otherwise, the dependency is unresolved.

    On Apple platforms, library resolution works as follows:

1.  If the dependency starts with @executable_path/, and an EXECUTABLES argument is in the process of being resolved, and replacing @executable_path/ with the directory of the executable yields an existing file, the dependency is resolved to that file.

2.  Otherwise, if the dependency starts with @executable_path/, and there is a BUNDLE_EXECUTABLE argument, and replacing @executable_path/ with the directory of the bundle executable yields an existing file, the dependency is resolved to that file.

3.  Otherwise, if the dependency starts with @loader_path/, and replacing @loader_path/ with the directory of the depending file yields an existing file, the dependency is resolved to that file.

4.  Otherwise, if the dependency starts with @rpath/, and replacing @rpath/ with one of the RPATH entries of the depending file yields an existing file, the dependency is resolved to that file. Note that RPATH entries that start with @executable_path/ or @loader_path/ also have these items replaced with the appropriate path.

5.  Otherwise, if the dependency is an absolute file that exists, the dependency is resolved to that file.

6.  Otherwise, the dependency is unresolved.

    This function accepts several variables that determine which tool is used for dependency resolution:

CMAKE_GET_RUNTIME_DEPENDENCIES_PLATFORM
    Determines which operating system and executable format the files are built for. This could be one of several values:

•   linux+elf

•   windows+pe

•   macos+macho

    If this variable is not specified, it is determined automatically by system introspection.

CMAKE_GET_RUNTIME_DEPENDENCIES_TOOL
    Determines the tool to use for dependency resolution. It could be one of several values, depending on the value of CMAKE_GET_RUNTIME_DEPENDENCIES_PLATFORM:
    CMAKE_GET_RUNTIME_DEPENDENCIES_PLATFORM | CMAKE_GET_RUNTIME_DEPENDENCIES_TOOL
    linux+elf | objdump
    windows+pe | objdump or dumpbin
    macos+macho | otool

    If this variable is not specified, it is determined automatically by system introspection.

CMAKE_GET_RUNTIME_DEPENDENCIES_COMMAND
    Determines the path to the tool to use for dependency resolution. This is the actual path to objdump, dumpbin, or otool.

    If this variable is not specified, it is determined by the value of CMAKE_OBJDUMP variable if set, else by system introspection.

    Added in version 3.18: Uses CMAKE_OBJDUMP if set.

  find_file

A short-hand signature is:

    find_file (<VAR> name1 [path1 path2 ...])

The general signature is:

    find_file (
              <VAR>
              name | NAMES name1 [name2 ...]
              [HINTS [path | ENV var]...]
              [PATHS [path | ENV var]...]
              [REGISTRY_VIEW (64|32|64_32|32_64|HOST|TARGET|BOTH)]
              [PATH_SUFFIXES suffix1 [suffix2 ...]]
              [VALIDATOR function]
              [DOC "cache documentation string"]
              [NO_CACHE]
              [REQUIRED]
              [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 full path to named file. A cache entry, or a normal variable if NO_CACHE is specified, named by <VAR> is created to store the result of this command. If the full path to a file is found the result is stored in the variable and the search will not be repeated unless the variable is cleared. If nothing is found, the result will be <VAR>-NOTFOUND.

Options include:

NAMES
    Specify one or more possible names for the full path to a file.

    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.

    Changed in version 3.24: On Windows platform, it is possible to include registry queries as part of the directories, using a dedicated syntax. Such specifications will be ignored on all other platforms.

REGISTRY_VIEW
    Added in version 3.24.

    Specify which registry views must be queried. This option is only meaningful on Windows platforms and will be ignored on other ones. When not specified, the TARGET view is used when the CMP0134 policy is NEW. Refer to CMP0134 for the default view when the policy is OLD.

64  Query the 64-bit registry. On 32-bit Windows, it always returns the string /REGISTRY-NOTFOUND.

32  Query the 32-bit registry.

64_32
    Query both views (64 and 32) and generate a path for each.

32_64
    Query both views (32 and 64) and generate a path for each.

HOST
    Query the registry matching the architecture of the host: 64 on 64-bit Windows and 32 on 32-bit Windows.

TARGET
    Query the registry matching the architecture specified by the CMAKE_SIZEOF_VOID_P variable. If not defined, fall back to HOST view.

BOTH
    Query both views (32 and 64). The order depends on the following rules: If the CMAKE_SIZEOF_VOID_P variable is defined, use the following view depending on the content of this variable:

•   8: 64_32

•   4: 32_64

    If the CMAKE_SIZEOF_VOID_P variable is not defined, rely on the architecture of the host:

•   64-bit: 64_32

•   32-bit: 32

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

VALIDATOR
    Added in version 3.25.

    Specify a function() to be called for each candidate item found (a 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.

        function(my_check validator_result_var item)
          if(NOT item MATCHES ...)
            set(${validator_result_var} FALSE PARENT_SCOPE)
          endif()
        endfunction()
        find_file (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
    Added in version 3.21.

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

    NOTE: If the variable is already set before the call (as a normal or cache variable) then the search will not occur.

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

REQUIRED
    Added in version 3.18.

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

    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:

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

    Added in version 3.12.

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

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

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

    Added in version 3.27.

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

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

    Added in version 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 CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE.

•   <prefix>/include/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/include for each <prefix> in the <PackageName>_ROOT CMake variable and the <PackageName>_ROOT environment variable if called from within a find module loaded by find_package(<PackageName>)

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 semicolon-separated lists. This can be skipped if NO_CMAKE_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_PATH to FALSE.

•   <prefix>/include/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/include for each <prefix> in CMAKE_PREFIX_PATH

•   CMAKE_INCLUDE_PATH

•   CMAKE_FRAMEWORK_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 CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH to FALSE.

•   <prefix>/include/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/include for each <prefix> in CMAKE_PREFIX_PATH

•   CMAKE_INCLUDE_PATH

•   CMAKE_FRAMEWORK_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 CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH to FALSE.

•   The directories in INCLUDE and PATH.

    On Windows hosts, CMake 3.3 through 3.27 searched additional paths: <prefix>/include/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/include for each <prefix>/[s]bin in PATH, and <entry>/include for other entries in PATH. This behavior was removed by CMake 3.28.

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 CMAKE_FIND_USE_INSTALL_PREFIX to FALSE. All these locations can be skipped if NO_CMAKE_SYSTEM_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_SYSTEM_PATH to FALSE.

•   <prefix>/include/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/include for each <prefix> in CMAKE_SYSTEM_PREFIX_PATH

•   CMAKE_SYSTEM_INCLUDE_PATH

•   CMAKE_SYSTEM_FRAMEWORK_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 CMAKE_IGNORE_PATH, CMAKE_IGNORE_PREFIX_PATH, CMAKE_SYSTEM_IGNORE_PATH and CMAKE_SYSTEM_IGNORE_PREFIX_PATH variables can also cause some of the above locations to be ignored.

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

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

    The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more directories to be prepended to all other search directories. This effectively "re-roots" the entire search under given locations. Paths which are descendants of the CMAKE_STAGING_PREFIX are excluded from this re-rooting, because that variable is always a path on the host system. By default the CMAKE_FIND_ROOT_PATH is empty.

    The CMAKE_SYSROOT variable can also be used to specify exactly one directory to use as a prefix. Setting CMAKE_SYSROOT also has other effects. See the documentation for that variable for more.

    These variables are especially useful when cross-compiling to point to the root directory of the target environment and CMake will search there too. By default at first the directories listed in CMAKE_FIND_ROOT_PATH are searched, then the CMAKE_SYSROOT directory is searched, and then the non-rooted directories will be searched. The default behavior can be adjusted by setting CMAKE_FIND_ROOT_PATH_MODE_INCLUDE. This behavior can be manually overridden on a per-call basis using options:

CMAKE_FIND_ROOT_PATH_BOTH
    Search in the order described above.

NO_CMAKE_FIND_ROOT_PATH
    Do not use the CMAKE_FIND_ROOT_PATH variable.

ONLY_CMAKE_FIND_ROOT_PATH
    Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.

    The default search order is designed to be most-specific to least-specific for common use cases. Projects may override the order by simply calling the command multiple times and using the NO_* options:

        find_file (<VAR> NAMES name PATHS paths... NO_DEFAULT_PATH)
        find_file (<VAR> NAMES name)

    Once one of the calls succeeds the result variable will be set and stored in the cache so that no call will search again.

  find_library

A short-hand signature is:

    find_library (<VAR> name1 [path1 path2 ...])

The general signature is:

    find_library (
              <VAR>
              name | NAMES name1 [name2 ...] [NAMES_PER_DIR]
              [HINTS [path | ENV var]...]
              [PATHS [path | ENV var]...]
              [REGISTRY_VIEW (64|32|64_32|32_64|HOST|TARGET|BOTH)]
              [PATH_SUFFIXES suffix1 [suffix2 ...]]
              [VALIDATOR function]
              [DOC "cache documentation string"]
              [NO_CACHE]
              [REQUIRED]
              [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 library. A cache entry, or a normal variable if NO_CACHE is specified, named by <VAR> is created to store the result of this command. If the library is found the result is stored in the variable and the search will not be repeated unless the variable is cleared. If nothing is found, the result will be <VAR>-NOTFOUND.

Options include:

NAMES
    Specify one or more possible names for the library.

    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.

    Changed in version 3.24: On Windows platform, it is possible to include registry queries as part of the directories, using a dedicated syntax. Such specifications will be ignored on all other platforms.

REGISTRY_VIEW
    Added in version 3.24.

    Specify which registry views must be queried. This option is only meaningful on Windows platforms and will be ignored on other ones. When not specified, the TARGET view is used when the CMP0134 policy is NEW. Refer to CMP0134 for the default view when the policy is OLD.

64  Query the 64-bit registry. On 32-bit Windows, it always returns the string /REGISTRY-NOTFOUND.

32  Query the 32-bit registry.

64_32
    Query both views (64 and 32) and generate a path for each.

32_64
    Query both views (32 and 64) and generate a path for each.

HOST
    Query the registry matching the architecture of the host: 64 on 64-bit Windows and 32 on 32-bit Windows.

TARGET
    Query the registry matching the architecture specified by the CMAKE_SIZEOF_VOID_P variable. If not defined, fall back to HOST view.

BOTH
    Query both views (32 and 64). The order depends on the following rules: If the CMAKE_SIZEOF_VOID_P variable is defined, use the following view depending on the content of this variable:

•   8: 64_32

•   4: 32_64

    If the CMAKE_SIZEOF_VOID_P variable is not defined, rely on the architecture of the host:

•   64-bit: 64_32

•   32-bit: 32

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

VALIDATOR
    Added in version 3.25.

    Specify a function() to be called for each candidate item found (a 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.

        function(my_check validator_result_var item)
          if(NOT item MATCHES ...)
            set(${validator_result_var} FALSE PARENT_SCOPE)
          endif()
        endfunction()
        find_library (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
    Added in version 3.21.

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

    NOTE: If the variable is already set before the call (as a normal or cache variable) then the search will not occur.

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

REQUIRED
    Added in version 3.18.

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

    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:

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

    Added in version 3.12.

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

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

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

    Added in version 3.27.

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

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

    Added in version 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 CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE.

•   <prefix>/lib/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/lib for each <prefix> in the <PackageName>_ROOT CMake variable and the <PackageName>_ROOT environment variable if called from within a find module loaded by find_package(<PackageName>)

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 semicolon-separated lists. This can be skipped if NO_CMAKE_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_PATH to FALSE.

•   <prefix>/lib/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/lib for each <prefix> in CMAKE_PREFIX_PATH

•   CMAKE_LIBRARY_PATH

•   CMAKE_FRAMEWORK_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 CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH to FALSE.

•   <prefix>/lib/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/lib for each <prefix> in CMAKE_PREFIX_PATH

•   CMAKE_LIBRARY_PATH

•   CMAKE_FRAMEWORK_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 CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH to FALSE.

•   The directories in LIB and PATH.

    On Windows hosts, CMake 3.3 through 3.27 searched additional paths: <prefix>/lib/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/lib for each <prefix>/[s]bin in PATH, and <entry>/lib for other entries in PATH. This behavior was removed by CMake 3.28.

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 CMAKE_FIND_USE_INSTALL_PREFIX to FALSE. All these locations can be skipped if NO_CMAKE_SYSTEM_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_SYSTEM_PATH to FALSE.

•   <prefix>/lib/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/lib for each <prefix> in CMAKE_SYSTEM_PREFIX_PATH

•   CMAKE_SYSTEM_LIBRARY_PATH

•   CMAKE_SYSTEM_FRAMEWORK_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 CMAKE_IGNORE_PATH, CMAKE_IGNORE_PREFIX_PATH, CMAKE_SYSTEM_IGNORE_PATH and CMAKE_SYSTEM_IGNORE_PREFIX_PATH variables can also cause some of the above locations to be ignored.

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

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

    The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more directories to be prepended to all other search directories. This effectively "re-roots" the entire search under given locations. Paths which are descendants of the CMAKE_STAGING_PREFIX are excluded from this re-rooting, because that variable is always a path on the host system. By default the CMAKE_FIND_ROOT_PATH is empty.

    The CMAKE_SYSROOT variable can also be used to specify exactly one directory to use as a prefix. Setting CMAKE_SYSROOT also has other effects. See the documentation for that variable for more.

    These variables are especially useful when cross-compiling to point to the root directory of the target environment and CMake will search there too. By default at first the directories listed in CMAKE_FIND_ROOT_PATH are searched, then the CMAKE_SYSROOT directory is searched, and then the non-rooted directories will be searched. The default behavior can be adjusted by setting CMAKE_FIND_ROOT_PATH_MODE_LIBRARY. This behavior can be manually overridden on a per-call basis using options:

CMAKE_FIND_ROOT_PATH_BOTH
    Search in the order described above.

NO_CMAKE_FIND_ROOT_PATH
    Do not use the CMAKE_FIND_ROOT_PATH variable.

ONLY_CMAKE_FIND_ROOT_PATH
    Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.

    The default search order is designed to be most-specific to least-specific for common use cases. Projects may override the order by simply calling the command multiple times and using the NO_* options:

        find_library (<VAR> NAMES name PATHS paths... NO_DEFAULT_PATH)
        find_library (<VAR> NAMES name)

    Once one of the calls succeeds the result variable will be set and stored in the cache so that no call will search again.

    When more than one value is given to the NAMES option this command by default will consider one name at a time and search every directory for it. The NAMES_PER_DIR option tells this command to consider one directory at a time and search for all names in it.

    Each library name given to the NAMES option is first considered as is, if it contains a library suffix, and then considered with platform-specific prefixes (e.g. lib) and suffixes (e.g. .so), as defined by the variables CMAKE_FIND_LIBRARY_PREFIXES and CMAKE_FIND_LIBRARY_SUFFIXES. Therefore one may specify library file names such as libfoo.a directly. This can be used to locate static libraries on UNIX-like systems.

    If the library found is a framework, then <VAR> will be set to the full path to the framework <fullPath>/A.framework. When a full path to a framework is used as a library, CMake will use a -framework A, and a -F<fullPath> to link the framework to the target.

    Added in version 3.28: The library found can now be a .xcframework folder.

    If the CMAKE_FIND_LIBRARY_CUSTOM_LIB_SUFFIX variable is set all search paths will be tested as normal, with the suffix appended, and with all matches of lib/ replaced with lib${CMAKE_FIND_LIBRARY_CUSTOM_LIB_SUFFIX}/. This variable overrides the FIND_LIBRARY_USE_LIB32_PATHS, FIND_LIBRARY_USE_LIBX32_PATHS, and FIND_LIBRARY_USE_LIB64_PATHS global properties.

    If the FIND_LIBRARY_USE_LIB32_PATHS global property is set all search paths will be tested as normal, with 32/ appended, and with all matches of lib/ replaced with lib32/. This property is automatically set for the platforms that are known to need it if at least one of the languages supported by the project() command is enabled.

    If the FIND_LIBRARY_USE_LIBX32_PATHS global property is set all search paths will be tested as normal, with x32/ appended, and with all matches of lib/ replaced with libx32/. This property is automatically set for the platforms that are known to need it if at least one of the languages supported by the project() command is enabled.

    If the FIND_LIBRARY_USE_LIB64_PATHS global property is set all search paths will be tested as normal, with 64/ appended, and with all matches of lib/ replaced with lib64/. This property is automatically set for the platforms that are known to need it if at least one of the languages supported by the project() command is enabled.

  find_package

NOTE: The Using Dependencies Guide provides a high-level introduction to this general topic. It provides a broader overview of where the find_package() command fits into the bigger picture, including its relationship to the FetchContent module. The guide is recommended pre-reading before moving on to the details below.

Find a package (usually provided by something external to the project), and load its package-specific details. Calls to this command can also be intercepted by dependency providers.

  Typical Usage

Most calls to find_package() typically have the following form:

    find_package(<PackageName> [<version>] [REQUIRED] [COMPONENTS <components>...])

The <PackageName> is the only mandatory argument. The <version> is often omitted, and REQUIRED should be given if the project cannot be configured successfully without the package. Some more complicated packages support components which can be selected with the COMPONENTS keyword, but most packages don't have that level of complexity.

The above is a reduced form of the basic signature. Where possible, projects should find packages using this form. This reduces complexity and maximizes the ways in which the package can be found or provided.

Understanding the basic signature should be enough for general usage of find_package(). Project maintainers who intend to provide a package configuration file should understand the bigger picture, as explained in Full Signature and all subsequent sections on this page.

  Search Modes

The command has a few modes by which it searches for packages:

Module mode
    In this mode, CMake searches for a file called Find<PackageName>.cmake, looking first in the locations listed in the CMAKE_MODULE_PATH, then among the Find Modules provided by the CMake installation. If the file is found, it is read and processed by CMake. It is responsible for finding the package, checking the version, and producing any needed messages. Some Find modules provide limited or no support for versioning; check the Find module's documentation.

    The Find<PackageName>.cmake file is not typically provided by the package itself. Rather, it is normally provided by something external to the package, such as the operating system, CMake itself, or even the project from which the find_package() command was called. Being externally provided, Find Modules tend to be heuristic in nature and are susceptible to becoming out-of-date. They typically search for certain libraries, files and other package artifacts.

    Module mode is only supported by the basic command signature.

Config mode
    In this mode, CMake searches for a file called <lowercasePackageName>-config.cmake or <PackageName>Config.cmake. It will also look for <lowercasePackageName>-config-version.cmake or <PackageName>ConfigVersion.cmake if version details were specified (see Config Mode Version Selection for an explanation of how these separate version files are used).

    NOTE: If the experimental CMAKE_EXPERIMENTAL_FIND_CPS_PACKAGES is enabled, files named <PackageName>.cps and <lowercasePackageName>.cps are also considered. These files provide package information according to the Common Package Specification (CPS), which is more portable than CMake script. Aside from any explicitly noted exceptions, any references to "config files", "config mode", "package configuration files", and so forth refer equally to both CPS and CMake-script files. This functionality is a work in progress, and some features may be missing.

    Search is implemented in a manner that will tend to prefer Common Package Specification files over CMake-script config files in most cases. Specifying CONFIGS suppresses consideration of CPS files.

    In config mode, the command can be given a list of names to search for as package names. The locations where CMake searches for the config and version files is considerably more complicated than for Module mode (see Config Mode Search Procedure).

    The config and version files are typically installed as part of the package, so they tend to be more reliable than Find modules. They usually contain direct knowledge of the package contents, so no searching or heuristics are needed within the config or version files themselves.

    Config mode is supported by both the basic and full command signatures.

FetchContent redirection mode
    Added in version 3.24: A call to find_package() can be redirected internally to a package provided by the FetchContent module. To the caller, the behavior will appear similar to Config mode, except that the search logic is by-passed and the component information is not used. See FetchContent_Declare() and FetchContent_MakeAvailable() for further details.

    When not redirected to a package provided by FetchContent, the command arguments determine whether Module or Config mode is used. When the basic signature is used, the command searches in Module mode first. If the package is not found, the search falls back to Config mode. A user may set the CMAKE_FIND_PACKAGE_PREFER_CONFIG variable to true to reverse the priority and direct CMake to search using Config mode first before falling back to Module mode. The basic signature can also be forced to use only Module mode with a MODULE keyword. If the full signature is used, the command only searches in Config mode.

  Basic Signature

    find_package(<PackageName> [version] [EXACT] [QUIET] [MODULE]
                 [REQUIRED] [[COMPONENTS] [components...]]
                 [OPTIONAL_COMPONENTS components...]
                 [REGISTRY_VIEW  (64|32|64_32|32_64|HOST|TARGET|BOTH)]
                 [GLOBAL]
                 [NO_POLICY_SCOPE]
                 [BYPASS_PROVIDER])

The basic signature is supported by both Module and Config modes. The MODULE keyword implies that only Module mode can be used to find the package, with no fallback to Config mode.

Regardless of the mode used, a <PackageName>_FOUND variable will be set to indicate whether the package was found. When the package is found, package-specific information may be provided through other variables and Imported Targets documented by the package itself. The QUIET option disables informational messages, including those indicating that the package cannot be found if it is not REQUIRED. The REQUIRED option stops processing with an error message if the package cannot be found.

A package-specific list of required components may be listed after the COMPONENTS keyword. If any of these components are not able to be satisfied, the package overall is considered to be not found. If the REQUIRED option is also present, this is treated as a fatal error, otherwise execution still continues. As a form of shorthand, if the REQUIRED option is present, the COMPONENTS keyword can be omitted and the required components can be listed directly after REQUIRED.

Additional optional components may be listed after OPTIONAL_COMPONENTS. If these cannot be satisfied, the package overall can still be considered found, as long as all required components are satisfied.

The set of available components and their meaning are defined by the target package:

•   For CMake-script package configuration files, it is formally up to the target package how to interpret the component information given to it, but it should follow the expectations stated above. For calls where no components are specified, there is no single expected behavior and target packages should clearly define what occurs in such cases. Common arrangements include assuming it should find all components, no components or some well-defined subset of the available components.

•   Common Package Specification packages consist of a root configuration file and zero or more appendices, each of which provide components and may have dependencies. CMake always attempts to load the root configuration file. Appendices are only loaded if their dependencies can be satisfied, and if they either provide requested components, or if no components were requested. If the dependencies of an appendix providing a required component cannot be satisfied, the package is considered not found. Otherwise, that appendix is ignored.

    Added in version 3.24: The REGISTRY_VIEW keyword specifies which registry views should be queried. This keyword is only meaningful on Windows platforms and will be ignored on all others. Formally, it is up to the target package how to interpret the registry view information given to it.

    Added in version 3.24: Specifying the GLOBAL keyword will promote all imported targets to a global scope in the importing project. Alternatively, this functionality can be enabled by setting the CMAKE_FIND_PACKAGE_TARGETS_GLOBAL variable.

    The [version] argument requests a version with which the package found should be compatible. There are two possible forms in which it may be specified:

•   A single version with the format major[.minor[.patch[.tweak]]], where each component is a numeric value.

•   A version range with the format versionMin...[<]versionMax where versionMin and versionMax have the same format and constraints on components being integers as the single version. By default, both end points are included. By specifying <, the upper end point will be excluded. Version ranges are only supported with CMake 3.19 or later.

    NOTE: With the exception of CPS packages, version support is currently provided only on a package-by-package basis. When a version range is specified but the package is only designed to expect a single version, the package will ignore the upper end point of the range and only take the single version at the lower end of the range into account. Non-CPS packages that do support version ranges do so in a manner that is determined by the individual package. See the Version Selection section below for details and important caveats.

    The EXACT option requests that the version be matched exactly. This option is incompatible with the specification of a version range.

    If no [version] and/or component list is given to a recursive invocation inside a find-module, the corresponding arguments are forwarded automatically from the outer call (including the EXACT flag for [version]).

    See the cmake_policy() command documentation for discussion of the NO_POLICY_SCOPE option.

    Added in version 3.24: The BYPASS_PROVIDER keyword is only allowed when find_package() is being called by a dependency provider. It can be used by providers to call the built-in find_package() implementation directly and prevent that call from being re-routed back to itself. Future versions of CMake may detect attempts to use this keyword from places other than a dependency provider and halt with a fatal error.

  Full Signature

    find_package(<PackageName> [version] [EXACT] [QUIET]
                 [REQUIRED] [[COMPONENTS] [components...]]
                 [OPTIONAL_COMPONENTS components...]
                 [CONFIG|NO_MODULE]
                 [GLOBAL]
                 [NO_POLICY_SCOPE]
                 [BYPASS_PROVIDER]
                 [NAMES name1 [name2 ...]]
                 [CONFIGS config1 [config2 ...]]
                 [HINTS path1 [path2 ...]]
                 [PATHS path1 [path2 ...]]
                 [REGISTRY_VIEW  (64|32|64_32|32_64|HOST|TARGET|BOTH)]
                 [PATH_SUFFIXES suffix1 [suffix2 ...]]
                 [NO_DEFAULT_PATH]
                 [NO_PACKAGE_ROOT_PATH]
                 [NO_CMAKE_PATH]
                 [NO_CMAKE_ENVIRONMENT_PATH]
                 [NO_SYSTEM_ENVIRONMENT_PATH]
                 [NO_CMAKE_PACKAGE_REGISTRY]
                 [NO_CMAKE_BUILDS_PATH] # Deprecated; does nothing.
                 [NO_CMAKE_SYSTEM_PATH]
                 [NO_CMAKE_INSTALL_PREFIX]
                 [NO_CMAKE_SYSTEM_PACKAGE_REGISTRY]
                 [CMAKE_FIND_ROOT_PATH_BOTH |
                  ONLY_CMAKE_FIND_ROOT_PATH |
                  NO_CMAKE_FIND_ROOT_PATH])

The CONFIG option, the synonymous NO_MODULE option, or the use of options not specified in the basic signature all enforce pure Config mode. In pure Config mode, the command skips Module mode search and proceeds at once with Config mode search.

Config mode search attempts to locate a configuration file provided by the package to be found. A cache entry called <PackageName>_DIR is created to hold the directory containing the file. By default, the command searches for a package with the name <PackageName>. If the NAMES option is given, the names following it are used instead of <PackageName>. The names are also considered when determining whether to redirect the call to a package provided by FetchContent.

The command searches for a file called <PackageName>Config.cmake or <lowercasePackageName>-config.cmake for each name specified. A replacement set of possible configuration file names may be given using the CONFIGS option. The Config Mode Search Procedure is specified below. Once found, any version constraint is checked, and if satisfied, the configuration file is read and processed by CMake. Since the file is provided by the package it already knows the location of package contents. The full path to the configuration file is stored in the CMake variable <PackageName>_CONFIG.

NOTE: If the experimental CMAKE_EXPERIMENTAL_FIND_CPS_PACKAGES is enabled, files named <PackageName>.cps and <lowercasePackageName>.cps are also considered, unless CONFIGS is given.

All configuration files which have been considered by CMake while searching for the package with an appropriate version are stored in the <PackageName>_CONSIDERED_CONFIGS variable, and the associated versions in the <PackageName>_CONSIDERED_VERSIONS variable.

If the package configuration file cannot be found, CMake will generate an error describing the problem unless the QUIET argument is specified. If REQUIRED is specified and the package is not found, a fatal error is generated and the configure step stops executing. If <PackageName>_DIR has been set to a directory not containing a configuration file, CMake will ignore it and search from scratch.

Package maintainers providing package configuration files are encouraged to name and install them such that the Config Mode Search Procedure outlined below will find them without requiring use of additional options.

  Config Mode Search Procedure

NOTE: When Config mode is used, this search procedure is applied regardless of whether the full or basic signature was given.

Added in version 3.24: All calls to find_package() (even in Module mode) first look for a config package file in the CMAKE_FIND_PACKAGE_REDIRECTS_DIR directory. The FetchContent module, or even the project itself, may write files to that location to redirect find_package() calls to content already provided by the project. If no config package file is found in that location, the search proceeds with the logic described below.

CMake constructs a set of possible installation prefixes for the package. Under each prefix several directories are searched for a configuration file. The tables below show the directories searched. Each entry is meant for installation trees following Windows (W), UNIX (U), or Apple (A) conventions:
Entry | Convention
<prefix>/<name>/cps/ [2] | W
<prefix>/<name>/*/cps/ [2] | W
<prefix>/cps/<name>/ [2] | W
<prefix>/cps/<name>/*/ [2] | W
<prefix>/cps/ [2] | W
<prefix>/ | W
<prefix>/(cmake|CMake)/ | W
<prefix>/<name>*/ | W
<prefix>/<name>*/(cmake|CMake)/ | W
<prefix>/<name>*/(cmake|CMake)/<name>*/ [1] | W
<prefix>/(lib/<arch>|lib*|share)/cps/<name>/ [2] | U
<prefix>/(lib/<arch>|lib*|share)/cps/<name>/*/ [2] | U
<prefix>/(lib/<arch>|lib*|share)/cps/ [2] | U
<prefix>/(lib/<arch>|lib*|share)/cmake/<name>*/ | U
<prefix>/(lib/<arch>|lib*|share)/<name>*/ | U
<prefix>/(lib/<arch>|lib*|share)/<name>*/(cmake|CMake)/ | U
<prefix>/<name>*/(lib/<arch>|lib*|share)/cmake/<name>*/ | W/U
<prefix>/<name>*/(lib/<arch>|lib*|share)/<name>*/ | W/U
<prefix>/<name>*/(lib/<arch>|lib*|share)/<name>*/(cmake|CMake)/ | W/U

[1] Added in version 3.25.

[2] Added in version 4.0.

    On systems supporting macOS FRAMEWORK and BUNDLE, the following directories are searched for Frameworks or Application Bundles containing a configuration file:
    Entry | Convention
    <prefix>/<name>.framework/Versions/*/Resources/CPS/ [3] | A
    <prefix>/<name>.framework/Resources/CPS/ [3] | A
    <prefix>/<name>.framework/Resources/ | A
    <prefix>/<name>.framework/Resources/CMake/ | A
    <prefix>/<name>.framework/Versions/*/Resources/ | A
    <prefix>/<name>.framework/Versions/*/Resources/CMake/ | A
    <prefix>/<name>.app/Contents/Resources/CPS/ [3] | A
    <prefix>/<name>.app/Contents/Resources/ | A
    <prefix>/<name>.app/Contents/Resources/CMake/ | A

[3] Added in version 4.0.

    When searching the above paths, find_package will only look for .cps files in search paths which contain /cps/, and will only look for .cmake files otherwise. (This only applies to the paths as specified and does not consider the contents of <prefix> or <name>.)

    In all cases the <name> is treated as case-insensitive and corresponds to any of the names specified (<PackageName> or names given by NAMES).

    If at least one compiled language has been enabled, the architecture-specific lib/<arch> and lib* directories may be searched based on the compiler's target architecture, in the following order:

lib/<arch>
    Searched if the CMAKE_LIBRARY_ARCHITECTURE variable is set.

lib64
    Searched on 64 bit platforms (CMAKE_SIZEOF_VOID_P is 8) and the FIND_LIBRARY_USE_LIB64_PATHS property is set to TRUE.

lib32
    Searched on 32 bit platforms (CMAKE_SIZEOF_VOID_P is 4) and the FIND_LIBRARY_USE_LIB32_PATHS property is set to TRUE.

libx32
    Searched on platforms using the x32 ABI if the FIND_LIBRARY_USE_LIBX32_PATHS property is set to TRUE.

lib Always searched.

    Changed in version 3.24: On Windows platform, it is possible to include registry queries as part of the directories specified through HINTS and PATHS keywords, using a dedicated syntax. Such specifications will be ignored on all other platforms.

    Added in version 3.24: REGISTRY_VIEW can be specified to manage Windows registry queries specified as part of PATHS and HINTS.

    Specify which registry views must be queried. This option is only meaningful on Windows platforms and will be ignored on other ones. When not specified, the TARGET view is used when the CMP0134 policy is NEW. Refer to CMP0134 for the default view when the policy is OLD.

64  Query the 64-bit registry. On 32-bit Windows, it always returns the string /REGISTRY-NOTFOUND.

32  Query the 32-bit registry.

64_32
    Query both views (64 and 32) and generate a path for each.

32_64
    Query both views (32 and 64) and generate a path for each.

HOST
    Query the registry matching the architecture of the host: 64 on 64-bit Windows and 32 on 32-bit Windows.

TARGET
    Query the registry matching the architecture specified by the CMAKE_SIZEOF_VOID_P variable. If not defined, fall back to HOST view.

BOTH
    Query both views (32 and 64). The order depends on the following rules: If the CMAKE_SIZEOF_VOID_P variable is defined, use the following view depending on the content of this variable:

•   8: 64_32

•   4: 32_64

    If the CMAKE_SIZEOF_VOID_P variable is not defined, rely on the architecture of the host:

•   64-bit: 64_32

•   32-bit: 32

    If PATH_SUFFIXES is specified, the suffixes are appended to each (W) or (U) directory entry one-by-one.

    This set of directories is intended to work in cooperation with projects that provide configuration files in their installation trees. Directories above marked with (W) are intended for installations on Windows where the prefix may point at the top of an application's installation directory. Those marked with (U) are intended for installations on UNIX platforms where the prefix is shared by multiple packages. This is merely a convention, so all (W) and (U) directories are still searched on all platforms. Directories marked with (A) are intended for installations on Apple platforms. The CMAKE_FIND_FRAMEWORK and CMAKE_FIND_APPBUNDLE variables determine the order of preference.

    WARNING: Setting CMAKE_FIND_FRAMEWORK or CMAKE_FIND_APPBUNDLE to values other than FIRST (the default) will cause CMake to search for Common Package Specification files in an order that is different from the order set forth in the specification.

    The set of installation prefixes is constructed using the following steps. If NO_DEFAULT_PATH is specified all NO_* options are enabled.

1.  Search prefixes unique to the current <PackageName> being found. See policy CMP0074.

    Added in version 3.12.

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

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

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

    Added in version 3.27.

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

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

    Added in version 3.27.

    The package root variables are maintained as a stack so if called from within a find module, root paths from the parent's find module will also be searched after paths for the current package. This can be skipped if NO_PACKAGE_ROOT_PATH is passed or by setting the CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE.

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 semicolon-separated lists. This can be skipped if NO_CMAKE_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_PATH to FALSE:

•   CMAKE_PREFIX_PATH

•   CMAKE_FRAMEWORK_PATH

•   CMAKE_APPBUNDLE_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 CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH to FALSE:

•   <PackageName>_DIR

•   CMAKE_PREFIX_PATH

•   CMAKE_FRAMEWORK_PATH

•   CMAKE_APPBUNDLE_PATH

4.  Search 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 CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH to FALSE. Path entries ending in /bin or /sbin are automatically converted to their parent directories:

•   PATH

6.  Search paths stored in the CMake User Package Registry. This can be skipped if NO_CMAKE_PACKAGE_REGISTRY is passed or by setting the variable CMAKE_FIND_USE_PACKAGE_REGISTRY to FALSE or the deprecated variable CMAKE_FIND_PACKAGE_NO_PACKAGE_REGISTRY to TRUE.

    See the cmake-packages(7) manual for details on the user package registry.

7.  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 CMAKE_FIND_USE_INSTALL_PREFIX to FALSE. All these locations can be skipped if NO_CMAKE_SYSTEM_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_SYSTEM_PATH to FALSE:

•   CMAKE_SYSTEM_PREFIX_PATH

•   CMAKE_SYSTEM_FRAMEWORK_PATH

•   CMAKE_SYSTEM_APPBUNDLE_PATH

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

8.  Search paths stored in the CMake System Package Registry. This can be skipped if NO_CMAKE_SYSTEM_PACKAGE_REGISTRY is passed or by setting the CMAKE_FIND_USE_SYSTEM_PACKAGE_REGISTRY variable to FALSE or the deprecated variable CMAKE_FIND_PACKAGE_NO_SYSTEM_PACKAGE_REGISTRY to TRUE.

    See the cmake-packages(7) manual for details on the system package registry.

9.  Search paths specified by the PATHS option. These are typically hard-coded guesses.

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

    Paths are searched in the order described above. The first viable package configuration file found is used, even if a newer version of the package resides later in the list of search paths.

    For search paths which contain glob expressions (*), the order in which directories matching the glob are searched is unspecified unless the CMAKE_FIND_PACKAGE_SORT_ORDER variable is set. This variable, along with the CMAKE_FIND_PACKAGE_SORT_DIRECTION variable, determines the order in which CMake considers glob matches. For example, if the file system contains the package configuration files

        <prefix>/example-1.2/example-config.cmake
        <prefix>/example-1.10/example-config.cmake
        <prefix>/share/example-2.0/example-config.cmake

    it is unspecified (when the aforementioned variables are unset) whether find_package(example) will find example-1.2 or example-1.10 (assuming that both are viable), but find_package will not find example-2.0, because one of the other two will be found first.

    To control the order in which find_package searches directories that match a glob expression, use CMAKE_FIND_PACKAGE_SORT_ORDER and CMAKE_FIND_PACKAGE_SORT_DIRECTION. For instance, to cause the above example to select example-1.10, one can set

        set(CMAKE_FIND_PACKAGE_SORT_ORDER NATURAL)
        set(CMAKE_FIND_PACKAGE_SORT_DIRECTION DEC)

    before calling find_package.

    Added in version 3.16: Added the CMAKE_FIND_USE_<CATEGORY> variables to globally disable various search locations.

    Changed in version 4.0: The variables CMAKE_FIND_PACKAGE_SORT_ORDER and CMAKE_FIND_PACKAGE_SORT_DIRECTION now also control the order in which find_package searches directories matching the glob expression in the search paths <prefix>/<name>.framework/Versions/*/Resources/ and <prefix>/<name>.framework/Versions/*/Resources/CMake. In previous versions of CMake, this order was unspecified.

    The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more directories to be prepended to all other search directories. This effectively "re-roots" the entire search under given locations. Paths which are descendants of the CMAKE_STAGING_PREFIX are excluded from this re-rooting, because that variable is always a path on the host system. By default the CMAKE_FIND_ROOT_PATH is empty.

    The CMAKE_SYSROOT variable can also be used to specify exactly one directory to use as a prefix. Setting CMAKE_SYSROOT also has other effects. See the documentation for that variable for more.

    These variables are especially useful when cross-compiling to point to the root directory of the target environment and CMake will search there too. By default at first the directories listed in CMAKE_FIND_ROOT_PATH are searched, then the CMAKE_SYSROOT directory is searched, and then the non-rooted directories will be searched. The default behavior can be adjusted by setting CMAKE_FIND_ROOT_PATH_MODE_PACKAGE. This behavior can be manually overridden on a per-call basis using options:

CMAKE_FIND_ROOT_PATH_BOTH
    Search in the order described above.

NO_CMAKE_FIND_ROOT_PATH
    Do not use the CMAKE_FIND_ROOT_PATH variable.

ONLY_CMAKE_FIND_ROOT_PATH
    Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.

    The default search order is designed to be most-specific to least-specific for common use cases. Projects may override the order by simply calling the command multiple times and using the NO_* options:

        find_package (<PackageName> PATHS paths... NO_DEFAULT_PATH)
        find_package (<PackageName>)

    Once one of the calls succeeds the result variable will be set and stored in the cache so that no call will search again.

    By default the value stored in the result variable will be the path at which the file is found. The CMAKE_FIND_PACKAGE_RESOLVE_SYMLINKS variable may be set to TRUE before calling find_package in order to resolve symbolic links and store the real path to the file.

    Every non-REQUIRED find_package call can be disabled or made REQUIRED:

•   Setting the CMAKE_DISABLE_FIND_PACKAGE_<PackageName> variable to TRUE disables the package. This also disables redirection to a package provided by FetchContent.

•   Setting the CMAKE_REQUIRE_FIND_PACKAGE_<PackageName> variable to TRUE makes the package REQUIRED.

    Setting both variables to TRUE simultaneously is an error.

  Config Mode Version Selection

NOTE: When Config mode is used, this version selection process is applied regardless of whether the full or basic signature was given.

When the [version] argument is given, Config mode will only find a version of the package that claims compatibility with the requested version (see format specification). If the EXACT option is given, only a version of the package claiming an exact match of the requested version may be found. CMake does not establish any convention for the meaning of version numbers.

  CMake-script

For CMake-script package configuration files, package version numbers are checked by "version" files provided by the packages themselves or by FetchContent. For a candidate package configuration file <config-file>.cmake the corresponding version file is located next to it and named either <config-file>-version.cmake or <config-file>Version.cmake. If no such version file is available then the configuration file is assumed to not be compatible with any requested version. A basic version file containing generic version matching code can be created using the CMakePackageConfigHelpers module. When a version file is found it is loaded to check the requested version number. The version file is loaded in a nested scope in which the following variables have been defined:

PACKAGE_FIND_NAME
    The <PackageName>

PACKAGE_FIND_VERSION
    Full requested version string

PACKAGE_FIND_VERSION_MAJOR
    Major version if requested, else 0

PACKAGE_FIND_VERSION_MINOR
    Minor version if requested, else 0

PACKAGE_FIND_VERSION_PATCH
    Patch version if requested, else 0

PACKAGE_FIND_VERSION_TWEAK
    Tweak version if requested, else 0

PACKAGE_FIND_VERSION_COUNT
    Number of version components, 0 to 4

    When a version range is specified, the above version variables will hold values based on the lower end of the version range. This is to preserve compatibility with packages that have not been implemented to expect version ranges. In addition, the version range will be described by the following variables:

PACKAGE_FIND_VERSION_RANGE
    Full requested version range string

PACKAGE_FIND_VERSION_RANGE_MIN
    This specifies whether the lower end point of the version range should be included or excluded. Currently, the only supported value for this variable is INCLUDE.

PACKAGE_FIND_VERSION_RANGE_MAX
    This specifies whether the upper end point of the version range should be included or excluded. The supported values for this variable are INCLUDE and EXCLUDE.

PACKAGE_FIND_VERSION_MIN
    Full requested version string of the lower end point of the range

PACKAGE_FIND_VERSION_MIN_MAJOR
    Major version of the lower end point if requested, else 0

PACKAGE_FIND_VERSION_MIN_MINOR
    Minor version of the lower end point if requested, else 0

PACKAGE_FIND_VERSION_MIN_PATCH
    Patch version of the lower end point if requested, else 0

PACKAGE_FIND_VERSION_MIN_TWEAK
    Tweak version of the lower end point if requested, else 0

PACKAGE_FIND_VERSION_MIN_COUNT
    Number of version components of the lower end point, 0 to 4

PACKAGE_FIND_VERSION_MAX
    Full requested version string of the upper end point of the range

PACKAGE_FIND_VERSION_MAX_MAJOR
    Major version of the upper end point if requested, else 0

PACKAGE_FIND_VERSION_MAX_MINOR
    Minor version of the upper end point if requested, else 0

PACKAGE_FIND_VERSION_MAX_PATCH
    Patch version of the upper end point if requested, else 0

PACKAGE_FIND_VERSION_MAX_TWEAK
    Tweak version of the upper end point if requested, else 0

PACKAGE_FIND_VERSION_MAX_COUNT
    Number of version components of the upper end point, 0 to 4

    Regardless of whether a single version or a version range is specified, the variable PACKAGE_FIND_VERSION_COMPLETE will be defined and will hold the full requested version string as specified.

    The version file checks whether it satisfies the requested version and sets these variables:

PACKAGE_VERSION
    Full provided version string

PACKAGE_VERSION_EXACT
    True if version is exact match

PACKAGE_VERSION_COMPATIBLE
    True if version is compatible

PACKAGE_VERSION_UNSUITABLE
    True if unsuitable as any version

    These variables are checked by the find_package command to determine whether the configuration file provides an acceptable version. They are not available after the find_package call returns. If the version is acceptable, the following variables are set:

<PackageName>_VERSION
    Full provided version string

<PackageName>_VERSION_MAJOR
    Major version if provided, else 0

<PackageName>_VERSION_MINOR
    Minor version if provided, else 0

<PackageName>_VERSION_PATCH
    Patch version if provided, else 0

<PackageName>_VERSION_TWEAK
    Tweak version if provided, else 0

<PackageName>_VERSION_COUNT
    Number of version components, 0 to 4

    and the corresponding package configuration file is loaded.

    NOTE: While the exact behavior of version matching is determined by the individual package, many packages use write_basic_package_version_file() to supply this logic. The version check scripts this produces have some notable caveats with respect to version ranges:

•   The upper end of a version range acts as a hard limit on what versions will be accepted. Thus, while a request for version 1.4.0 might be satisfied by a package whose version is 1.6.0 and which advertises 'same major version' compatibility, the same package will be rejected if the requested version range is 1.4.0...1.5.0.

•   Both ends of the version range must match the package's advertised compatibility level. For example, if a package advertises 'same major and minor version' compatibility, requesting the version range 1.4.0...<1.5.5 or 1.4.0...1.5.0 will result in that package being rejected, even if the package version is 1.4.1.

    As a result, it is not possible to use a version range to extend the range of compatible package versions that will be accepted.

  Common Package Specification

For Common Package Specification package configuration files, package version numbers are checked by CMake according to the set of recognized version schemas. At present, the following schemas are recognized:

simple
    Version numbers are a tuple of integers followed by an optional trailing segment which is ignored with respect to version comparisons.

custom
    The mechanism for interpreting version numbers is unspecified. The version strings must match exactly for the package to be accepted.

    Refer to version_schema for a more detailed explanation of each schema and how comparisons for each are performed. Note that the specification may include schemas that are not supported by CMake.

    In addition to the package's version, CPS allows packages to optionally specify a compat_version, which is the oldest version for which the package provides compatibility. That is, the package warrants that a consumer expecting the compat_version should be able to use the package, even if the package's actual version is newer. If not specified, the compat_version is implicitly equal to the package version, i.e. no backwards compatibility is provided.

    When a package uses a recognized schema, CMake will determine the package's acceptability according to the following rules:

•   If EXACT was specified, or if the package does not supply a compat_version, the package's version must equal the requested version.

•   Otherwise:

•   The package's version must be greater than or equal to the requested (minimum) version, and

•   the package's compat_version must be less than or equal to the requested (minimum) version, and

•   if a requested maximum version was given, it must be greater than (or equal to, depending on whether the maximum version is specified as inclusive or exclusive) the package's version.

    NOTE: This implementation of range matching was chosen in order to most closely match the behavior of write_basic_package_version_file(), albeit without the case where an overly broad range matches nothing.

    For packages using the simple version schema, if the version is acceptable, the following variables are set:

<PackageName>_VERSION
    Full provided version string

<PackageName>_VERSION_MAJOR
    Major version if provided, else 0

<PackageName>_VERSION_MINOR
    Minor version if provided, else 0

<PackageName>_VERSION_PATCH
    Patch version if provided, else 0

<PackageName>_VERSION_TWEAK
    Tweak version if provided, else 0

<PackageName>_VERSION_COUNT
    Number of version components, non-negative

  Package File Interface Variables

When loading a find module or CMake-script package configuration file, find_package defines variables to provide information about the call arguments (and restores their original state before returning):

CMAKE_FIND_PACKAGE_NAME
    The <PackageName> which is searched for

<PackageName>_FIND_REQUIRED
    True if REQUIRED option was given

<PackageName>_FIND_QUIETLY
    True if QUIET option was given

<PackageName>_FIND_REGISTRY_VIEW
    The requested view if REGISTRY_VIEW option was given

<PackageName>_FIND_VERSION
    Full requested version string

<PackageName>_FIND_VERSION_MAJOR
    Major version if requested, else 0

<PackageName>_FIND_VERSION_MINOR
    Minor version if requested, else 0

<PackageName>_FIND_VERSION_PATCH
    Patch version if requested, else 0

<PackageName>_FIND_VERSION_TWEAK
    Tweak version if requested, else 0

<PackageName>_FIND_VERSION_COUNT
    Number of version components, 0 to 4

<PackageName>_FIND_VERSION_EXACT
    True if EXACT option was given

<PackageName>_FIND_COMPONENTS
    List of specified components (required and optional)

<PackageName>_FIND_REQUIRED_<c>
    True if component <c> is required, false if component <c> is optional

    When a version range is specified, the above version variables will hold values based on the lower end of the version range. This is to preserve compatibility with packages that have not been implemented to expect version ranges. In addition, the version range will be described by the following variables:

<PackageName>_FIND_VERSION_RANGE
    Full requested version range string

<PackageName>_FIND_VERSION_RANGE_MIN
    This specifies whether the lower end point of the version range is included or excluded. Currently, INCLUDE is the only supported value.

<PackageName>_FIND_VERSION_RANGE_MAX
    This specifies whether the upper end point of the version range is included or excluded. The possible values for this variable are INCLUDE or EXCLUDE.

<PackageName>_FIND_VERSION_MIN
    Full requested version string of the lower end point of the range

<PackageName>_FIND_VERSION_MIN_MAJOR
    Major version of the lower end point if requested, else 0

<PackageName>_FIND_VERSION_MIN_MINOR
    Minor version of the lower end point if requested, else 0

<PackageName>_FIND_VERSION_MIN_PATCH
    Patch version of the lower end point if requested, else 0

<PackageName>_FIND_VERSION_MIN_TWEAK
    Tweak version of the lower end point if requested, else 0

<PackageName>_FIND_VERSION_MIN_COUNT
    Number of version components of the lower end point, 0 to 4

<PackageName>_FIND_VERSION_MAX
    Full requested version string of the upper end point of the range

<PackageName>_FIND_VERSION_MAX_MAJOR
    Major version of the upper end point if requested, else 0

<PackageName>_FIND_VERSION_MAX_MINOR
    Minor version of the upper end point if requested, else 0

<PackageName>_FIND_VERSION_MAX_PATCH
    Patch version of the upper end point if requested, else 0

<PackageName>_FIND_VERSION_MAX_TWEAK
    Tweak version of the upper end point if requested, else 0

<PackageName>_FIND_VERSION_MAX_COUNT
    Number of version components of the upper end point, 0 to 4

    Regardless of whether a single version or a version range is specified, the variable <PackageName>_FIND_VERSION_COMPLETE will be defined and will hold the full requested version string as specified.

    In Module mode the loaded find module is responsible to honor the request detailed by these variables; see the find module for details. In Config mode find_package handles REQUIRED, QUIET, and [version] options automatically but leaves it to the package configuration file to handle components in a way that makes sense for the package. The package configuration file may set <PackageName>_FOUND to false to tell find_package that component requirements are not satisfied.

  CPS Transitive Requirements

A Common Package Specification package description consists of one or more components which may in turn depend on other components either internal or external to the package. When external components are required, the providing package is noted as a package-level requirement of the package. Additionally, the set of required components is typically noted in said external package requirement.

Where a CMake-script package description would use the find_dependency() command to handle transitive dependencies, CMake handles transitive dependencies for CPS itself using an internally nested find_package call. This call can resolve CPS package dependencies via either another CPS package, or via a CMake-script package. The manner in which the CPS component dependencies are handled is subject to some caveats.

When the candidate for resolving a transitive dependency is another CPS package, things are simple; COMPONENTS and CPS "components" are directly comparable (and are effectively synonymous with CMake "imported targets"). CMake-script packages, however, are encouraged to (and often do) check that required components were found, whether or not the package describes separate components. Additionally, even those that do describe components typically do not have the same correlation to imported targets that is normal for CPS. As a result, passing the set of required components declared by a CPS package to COMPONENTS would result in spurious failures to resolve dependencies.

To address this, if a candidate for resolving a CPS transitive dependency is a CMake-script package, CMake passes the required components as declared by the consuming CPS package as OPTIONAL_COMPONENTS and performs a separate, internal check that the candidate package supplied the required imported targets. Those targets must be named <PackageName>::<ComponentName>, in conformance with CPS convention, or the check will consider the package not found.

  find_path

A short-hand signature is:

    find_path (<VAR> name1 [path1 path2 ...])

The general signature is:

    find_path (
              <VAR>
              name | NAMES name1 [name2 ...]
              [HINTS [path | ENV var]...]
              [PATHS [path | ENV var]...]
              [REGISTRY_VIEW (64|32|64_32|32_64|HOST|TARGET|BOTH)]
              [PATH_SUFFIXES suffix1 [suffix2 ...]]
              [VALIDATOR function]
              [DOC "cache documentation string"]
              [NO_CACHE]
              [REQUIRED]
              [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 directory containing the named file. A cache entry, or a normal variable if NO_CACHE is specified, named by <VAR> is created to store the result of this command. If the file in a directory is found the result is stored in the variable and the search will not be repeated unless the variable is cleared. If nothing is found, the result will be <VAR>-NOTFOUND.

Options include:

NAMES
    Specify one or more possible names for the file in a directory.

    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.

    Changed in version 3.24: On Windows platform, it is possible to include registry queries as part of the directories, using a dedicated syntax. Such specifications will be ignored on all other platforms.

REGISTRY_VIEW
    Added in version 3.24.

    Specify which registry views must be queried. This option is only meaningful on Windows platforms and will be ignored on other ones. When not specified, the TARGET view is used when the CMP0134 policy is NEW. Refer to CMP0134 for the default view when the policy is OLD.

64  Query the 64-bit registry. On 32-bit Windows, it always returns the string /REGISTRY-NOTFOUND.

32  Query the 32-bit registry.

64_32
    Query both views (64 and 32) and generate a path for each.

32_64
    Query both views (32 and 64) and generate a path for each.

HOST
    Query the registry matching the architecture of the host: 64 on 64-bit Windows and 32 on 32-bit Windows.

TARGET
    Query the registry matching the architecture specified by the CMAKE_SIZEOF_VOID_P variable. If not defined, fall back to HOST view.

BOTH
    Query both views (32 and 64). The order depends on the following rules: If the CMAKE_SIZEOF_VOID_P variable is defined, use the following view depending on the content of this variable:

•   8: 64_32

•   4: 32_64

    If the CMAKE_SIZEOF_VOID_P variable is not defined, rely on the architecture of the host:

•   64-bit: 64_32

•   32-bit: 32

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

VALIDATOR
    Added in version 3.25.

    Specify a function() to be called for each candidate item found (a 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.

        function(my_check validator_result_var item)
          if(NOT item MATCHES ...)
            set(${validator_result_var} FALSE PARENT_SCOPE)
          endif()
        endfunction()
        find_path (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
    Added in version 3.21.

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

    NOTE: If the variable is already set before the call (as a normal or cache variable) then the search will not occur.

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

REQUIRED
    Added in version 3.18.

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

    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:

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

    Added in version 3.12.

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

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

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

    Added in version 3.27.

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

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

    Added in version 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 CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE.

•   <prefix>/include/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/include for each <prefix> in the <PackageName>_ROOT CMake variable and the <PackageName>_ROOT environment variable if called from within a find module loaded by find_package(<PackageName>)

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 semicolon-separated lists. This can be skipped if NO_CMAKE_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_PATH to FALSE.

•   <prefix>/include/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/include for each <prefix> in CMAKE_PREFIX_PATH

•   CMAKE_INCLUDE_PATH

•   CMAKE_FRAMEWORK_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 CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH to FALSE.

•   <prefix>/include/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/include for each <prefix> in CMAKE_PREFIX_PATH

•   CMAKE_INCLUDE_PATH

•   CMAKE_FRAMEWORK_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 CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH to FALSE.

•   The directories in INCLUDE and PATH.

    On Windows hosts, CMake 3.3 through 3.27 searched additional paths: <prefix>/include/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/include for each <prefix>/[s]bin in PATH, and <entry>/include for other entries in PATH. This behavior was removed by CMake 3.28.

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 CMAKE_FIND_USE_INSTALL_PREFIX to FALSE. All these locations can be skipped if NO_CMAKE_SYSTEM_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_SYSTEM_PATH to FALSE.

•   <prefix>/include/<arch> if CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/include for each <prefix> in CMAKE_SYSTEM_PREFIX_PATH

•   CMAKE_SYSTEM_INCLUDE_PATH

•   CMAKE_SYSTEM_FRAMEWORK_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 CMAKE_IGNORE_PATH, CMAKE_IGNORE_PREFIX_PATH, CMAKE_SYSTEM_IGNORE_PATH and CMAKE_SYSTEM_IGNORE_PREFIX_PATH variables can also cause some of the above locations to be ignored.

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

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

    The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more directories to be prepended to all other search directories. This effectively "re-roots" the entire search under given locations. Paths which are descendants of the CMAKE_STAGING_PREFIX are excluded from this re-rooting, because that variable is always a path on the host system. By default the CMAKE_FIND_ROOT_PATH is empty.

    The CMAKE_SYSROOT variable can also be used to specify exactly one directory to use as a prefix. Setting CMAKE_SYSROOT also has other effects. See the documentation for that variable for more.

    These variables are especially useful when cross-compiling to point to the root directory of the target environment and CMake will search there too. By default at first the directories listed in CMAKE_FIND_ROOT_PATH are searched, then the CMAKE_SYSROOT directory is searched, and then the non-rooted directories will be searched. The default behavior can be adjusted by setting CMAKE_FIND_ROOT_PATH_MODE_INCLUDE. This behavior can be manually overridden on a per-call basis using options:

CMAKE_FIND_ROOT_PATH_BOTH
    Search in the order described above.

NO_CMAKE_FIND_ROOT_PATH
    Do not use the CMAKE_FIND_ROOT_PATH variable.

ONLY_CMAKE_FIND_ROOT_PATH
    Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.

    The default search order is designed to be most-specific to least-specific for common use cases. Projects may override the order by simply calling the command multiple times and using the NO_* options:

        find_path (<VAR> NAMES name PATHS paths... NO_DEFAULT_PATH)
        find_path (<VAR> NAMES name)

    Once one of the calls succeeds the result variable will be set and stored in the cache so that no call will search again.

    When searching for frameworks, if the file is specified as A/b.h, then the framework search will look for A.framework/Headers/b.h. If that is found the path will be set to the path to the framework. CMake will convert this to the correct -F option to include the file.

  find_program

A short-hand signature is:

    find_program (<VAR> name1 [path1 path2 ...])

The general signature is:

    find_program (
              <VAR>
              name | NAMES name1 [name2 ...] [NAMES_PER_DIR]
              [HINTS [path | ENV var]...]
              [PATHS [path | ENV var]...]
              [REGISTRY_VIEW (64|32|64_32|32_64|HOST|TARGET|BOTH)]
              [PATH_SUFFIXES suffix1 [suffix2 ...]]
              [VALIDATOR function]
              [DOC "cache documentation string"]
              [NO_CACHE]
              [REQUIRED]
              [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 program. A cache entry, or a normal variable if NO_CACHE is specified, named by <VAR> is created to store the result of this command. If the program is found the result is stored in the variable and the search will not be repeated unless the variable is cleared. If nothing is found, the result will be <VAR>-NOTFOUND.

Options include:

NAMES
    Specify one or more possible names for the program.

    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.

    Changed in version 3.24: On Windows platform, it is possible to include registry queries as part of the directories, using a dedicated syntax. Such specifications will be ignored on all other platforms.

REGISTRY_VIEW
    Added in version 3.24.

    Specify which registry views must be queried. This option is only meaningful on Windows platforms and will be ignored on other ones. When not specified, the BOTH view is used when the CMP0134 policy is NEW. Refer to CMP0134 for the default view when the policy is OLD.

64  Query the 64-bit registry. On 32-bit Windows, it always returns the string /REGISTRY-NOTFOUND.

32  Query the 32-bit registry.

64_32
    Query both views (64 and 32) and generate a path for each.

32_64
    Query both views (32 and 64) and generate a path for each.

HOST
    Query the registry matching the architecture of the host: 64 on 64-bit Windows and 32 on 32-bit Windows.

TARGET
    Query the registry matching the architecture specified by the CMAKE_SIZEOF_VOID_P variable. If not defined, fall back to HOST view.

BOTH
    Query both views (32 and 64). The order depends on the following rules: If the CMAKE_SIZEOF_VOID_P variable is defined, use the following view depending on the content of this variable:

•   8: 64_32

•   4: 32_64

    If the CMAKE_SIZEOF_VOID_P variable is not defined, rely on the architecture of the host:

•   64-bit: 64_32

•   32-bit: 32

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

VALIDATOR
    Added in version 3.25.

    Specify a function() to be called for each candidate item found (a 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.

        function(my_check validator_result_var item)
          if(NOT item MATCHES ...)
            set(${validator_result_var} FALSE PARENT_SCOPE)
          endif()
        endfunction()
        find_program (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
    Added in version 3.21.

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

    NOTE: If the variable is already set before the call (as a normal or cache variable) then the search will not occur.

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

REQUIRED
    Added in version 3.18.

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

    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:

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

    Added in version 3.12.

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

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

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

    Added in version 3.27.

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

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

    Added in version 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 CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE.

•   <prefix>/[s]bin for each <prefix> in the <PackageName>_ROOT CMake variable and the <PackageName>_ROOT environment variable if called from within a find module loaded by find_package(<PackageName>)

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 semicolon-separated lists. This can be skipped if NO_CMAKE_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_PATH to FALSE.

•   <prefix>/[s]bin for each <prefix> in CMAKE_PREFIX_PATH

•   CMAKE_PROGRAM_PATH

•   CMAKE_APPBUNDLE_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 CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH to FALSE.

•   <prefix>/[s]bin for each <prefix> in CMAKE_PREFIX_PATH

•   CMAKE_PROGRAM_PATH

•   CMAKE_APPBUNDLE_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 CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH to FALSE.

•   The directories in PATH itself.

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 CMAKE_FIND_USE_INSTALL_PREFIX to FALSE. All these locations can be skipped if NO_CMAKE_SYSTEM_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_SYSTEM_PATH to FALSE.

•   <prefix>/[s]bin for each <prefix> in CMAKE_SYSTEM_PREFIX_PATH

•   CMAKE_SYSTEM_PROGRAM_PATH

•   CMAKE_SYSTEM_APPBUNDLE_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 CMAKE_IGNORE_PATH, CMAKE_IGNORE_PREFIX_PATH, CMAKE_SYSTEM_IGNORE_PATH and CMAKE_SYSTEM_IGNORE_PREFIX_PATH variables can also cause some of the above locations to be ignored.

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

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

    The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more directories to be prepended to all other search directories. This effectively "re-roots" the entire search under given locations. Paths which are descendants of the CMAKE_STAGING_PREFIX are excluded from this re-rooting, because that variable is always a path on the host system. By default the CMAKE_FIND_ROOT_PATH is empty.

    The CMAKE_SYSROOT variable can also be used to specify exactly one directory to use as a prefix. Setting CMAKE_SYSROOT also has other effects. See the documentation for that variable for more.

    These variables are especially useful when cross-compiling to point to the root directory of the target environment and CMake will search there too. By default at first the directories listed in CMAKE_FIND_ROOT_PATH are searched, then the CMAKE_SYSROOT directory is searched, and then the non-rooted directories will be searched. The default behavior can be adjusted by setting CMAKE_FIND_ROOT_PATH_MODE_PROGRAM. This behavior can be manually overridden on a per-call basis using options:

CMAKE_FIND_ROOT_PATH_BOTH
    Search in the order described above.

NO_CMAKE_FIND_ROOT_PATH
    Do not use the CMAKE_FIND_ROOT_PATH variable.

ONLY_CMAKE_FIND_ROOT_PATH
    Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.

    The default search order is designed to be most-specific to least-specific for common use cases. Projects may override the order by simply calling the command multiple times and using the NO_* options:

        find_program (<VAR> NAMES name PATHS paths... NO_DEFAULT_PATH)
        find_program (<VAR> NAMES name)

    Once one of the calls succeeds the result variable will be set and stored in the cache so that no call will search again.

    When more than one value is given to the NAMES option this command by default will consider one name at a time and search every directory for it. The NAMES_PER_DIR option tells this command to consider one directory at a time and search for all names in it.

    The set of files considered to be programs is platform-specific:

•   On Windows, filename suffixes are considered in order .com, .exe, and no suffix.

•   On non-Windows systems, no filename suffix is considered, but files must have execute permission (see policy CMP0109).

    To search for scripts, specify an extension explicitly:

        if(WIN32)
          set(_script_suffix .bat)
        else()
          set(_script_suffix .sh)
        endif()
        find_program(MY_SCRIPT NAMES my_script${_script_suffix})

  foreach

Evaluate a group of commands for each value in a list.

    foreach(<loop_var> <items>)
      <commands>
    endforeach()

where <items> is a list of items that are separated by semicolon or whitespace. All commands between foreach and the matching endforeach are recorded without being invoked. Once the endforeach is evaluated, the recorded list of commands is invoked once for each item in <items>. At the beginning of each iteration the variable <loop_var> will be set to the value of the current item.

The scope of <loop_var> is restricted to the loop scope. See policy CMP0124 for details.

The commands break() and continue() provide means to escape from the normal control flow.

Per legacy, the endforeach() command admits an optional <loop_var> argument. If used, it must be a verbatim repeat of the argument of the opening foreach command.

    foreach(<loop_var> RANGE <stop>)

In this variant, foreach iterates over the numbers 0, 1, ... up to (and including) the nonnegative integer <stop>.

    foreach(<loop_var> RANGE <start> <stop> [<step>])

In this variant, foreach iterates over the numbers from <start> up to at most <stop> in steps of <step>. If <step> is not specified, then the step size is 1. The three arguments <start> <stop> <step> must all be nonnegative integers, and <stop> must not be smaller than <start>; otherwise you enter the danger zone of undocumented behavior that may change in future releases.

    foreach(<loop_var> IN [LISTS [<lists>]] [ITEMS [<items>]])

In this variant, <lists> is a whitespace or semicolon separated list of list-valued variables. The foreach command iterates over each item in each given list. The <items> following the ITEMS keyword are processed as in the first variant of the foreach command. The forms LISTS A and ITEMS ${A} are equivalent.

The following example shows how the LISTS option is processed:

    set(A 0;1)
    set(B 2 3)
    set(C "4 5")
    set(D 6;7 8)
    set(E "")
    foreach(X IN LISTS A B C D E)
        message(STATUS "X=${X}")
    endforeach()

yields:

    -- X=0
    -- X=1
    -- X=2
    -- X=3
    -- X=4 5
    -- X=6
    -- X=7
    -- X=8

    foreach(<loop_var>... IN ZIP_LISTS <lists>)

Added in version 3.17.

In this variant, <lists> is a whitespace or semicolon separated list of list-valued variables. The foreach command iterates over each list simultaneously setting the iteration variables as follows:

•   if the only loop_var given, then it sets a series of loop_var_N variables to the current item from the corresponding list;

•   if multiple variable names passed, their count should match the lists variables count;

•   if any of the lists are shorter, the corresponding iteration variable is not defined for the current iteration.

        list(APPEND English one two three four)
        list(APPEND Bahasa satu dua tiga)
        foreach(num IN ZIP_LISTS English Bahasa)
            message(STATUS "num_0=${num_0}, num_1=${num_1}")
        endforeach()
        foreach(en ba IN ZIP_LISTS English Bahasa)
            message(STATUS "en=${en}, ba=${ba}")
        endforeach()

    yields:

        -- num_0=one, num_1=satu
        -- num_0=two, num_1=dua
        -- num_0=three, num_1=tiga
        -- num_0=four, num_1=
        -- en=one, ba=satu
        -- en=two, ba=dua
        -- en=three, ba=tiga
        -- en=four, ba=

  See Also

•   break()

•   continue()

•   endforeach()

•   while()

  function

Start recording a function for later invocation as a command.

    function(<name> [<arg1> ...])
      <commands>
    endfunction()

Defines a function named <name> that takes arguments named <arg1>, ... The <commands> in the function definition are recorded; they are not executed until the function is invoked.

Per legacy, the endfunction() command admits an optional <name> argument. If used, it must be a verbatim repeat of the argument of the opening function command.

A function opens a new scope: see set(var PARENT_SCOPE) for details.

See the cmake_policy() command documentation for the behavior of policies inside functions.

See the macro() command documentation for differences between CMake functions and macros.

  Invocation

The function invocation is case-insensitive. A function defined as

    function(foo)
      <commands>
    endfunction()

can be invoked through any of

    foo()
    Foo()
    FOO()
    cmake_language(CALL foo)

and so on. However, it is strongly recommended to stay with the case chosen in the function definition. Typically functions use all-lowercase names.

Added in version 3.18: The cmake_language(CALL ...) command can also be used to invoke the function.

  Arguments

When the function is invoked, the recorded <commands> are first modified by replacing formal parameters (${arg1}, ...) with the arguments passed, and then invoked as normal commands.

In addition to referencing the formal parameters you can reference the ARGC variable which will be set to the number of arguments passed into the function as well as ARGV0, ARGV1, ARGV2, ... which will have the actual values of the arguments passed in. This facilitates creating functions with optional arguments.

Furthermore, ARGV holds the list of all arguments given to the function and ARGN holds the list of arguments past the last expected argument. Referencing to ARGV# arguments beyond ARGC have undefined behavior. Checking that ARGC is greater than # is the only way to ensure that ARGV# was passed to the function as an extra argument.

  See Also

•   cmake_parse_arguments()

•   endfunction()

•   return()

  get_cmake_property

Get a global property of the CMake instance.

    get_cmake_property(<variable> <property>)

Gets a global property from the CMake instance. The value of the <property> is stored in the specified <variable>. If the property is not found, <variable> will be set to NOTFOUND. See the cmake-properties(7) manual for available properties.

In addition to global properties, this command (for historical reasons) also supports the VARIABLES and MACROS directory properties. It also supports a special COMPONENTS global property that lists the components given to the install() command.

  See Also

•   the get_property() command GLOBAL option

  get_directory_property

Get a property of DIRECTORY scope.

    get_directory_property(<variable> [DIRECTORY <dir>] <prop-name>)

Stores a property of directory scope in the named <variable>.

The DIRECTORY argument specifies another directory from which to retrieve the property value instead of the current directory. Relative paths are treated as relative to the current source directory. CMake must already know about the directory, either by having added it through a call to add_subdirectory() or being the top level directory.

Added in version 3.19: <dir> may reference a binary directory.

If the property is not defined for the nominated directory scope, an empty string is returned. In the case of INHERITED properties, if the property is not found for the nominated directory scope, the search will chain to a parent scope as described for the define_property() command.

    get_directory_property(<variable> [DIRECTORY <dir>]
                           DEFINITION <var-name>)

Get a variable definition from a directory. This form is useful to get a variable definition from another directory.

  See Also

•   define_property()

•   the more general get_property() command

  get_filename_component

Get a specific component of a full filename.

Changed in version 3.20: This command has been superseded by the cmake_path() command, except for REALPATH, which is now offered by file(REAL_PATH), and PROGRAM, now available in separate_arguments(PROGRAM).

Changed in version 3.24: The undocumented feature offering the capability to query the Windows registry is superseded by cmake_host_system_information(QUERY WINDOWS_REGISTRY) command.

    get_filename_component(<var> <FileName> <mode> [CACHE])

Sets <var> to a component of <FileName>, where <mode> is one of:

•   DIRECTORY - directory without file name.

•   NAME - file name without directory.

•   EXT - file name longest extension (.b.c from d/a.b.c).

•   NAME_WE - file name with neither the directory nor the longest extension.

•   LAST_EXT - file name last extension (.c from d/a.b.c).

•   NAME_WLE - file name with neither the directory nor the last extension.

•   PATH - legacy alias for DIRECTORY (use for CMake <= 2.8.11).

    Added in version 3.14: Added the LAST_EXT and NAME_WLE modes.

    Paths are returned with forward slashes and have no trailing slashes. If the optional CACHE argument is specified, the result variable is added to the cache.

        get_filename_component(<var> <FileName> <mode> [BASE_DIR <dir>] [CACHE])

    Added in version 3.4.

    Sets <var> to the absolute path of <FileName>, where <mode> is one of:

•   ABSOLUTE - full path to file.

•   REALPATH - full path to existing file with symlinks resolved.

    If the provided <FileName> is a relative path, it is evaluated relative to the given base directory <dir>. If no base directory is provided, the default base directory will be CMAKE_CURRENT_SOURCE_DIR.

    Paths are returned with forward slashes and have no trailing slashes. If the optional CACHE argument is specified, the result variable is added to the cache.

        get_filename_component(<var> <FileName> PROGRAM [PROGRAM_ARGS <arg_var>] [CACHE])

    The program in <FileName> will be found in the system search path or left as a full path. If PROGRAM_ARGS is present with PROGRAM, then any command-line arguments present in the <FileName> string are split from the program name and stored in <arg_var>. This is used to separate a program name from its arguments in a command line string.

  See Also

•   cmake_path()

  get_property

Get a property.

    get_property(<variable>
                 <GLOBAL             |
                  DIRECTORY [<dir>]  |
                  TARGET    <target> |
                  SOURCE    <source>
                            [DIRECTORY <dir> | TARGET_DIRECTORY <target>] |
                  INSTALL   <file>   |
                  TEST      <test>
                            [DIRECTORY <dir>] |
                  CACHE     <entry>  |
                  VARIABLE           >
                 PROPERTY <name>
                 [SET | DEFINED | BRIEF_DOCS | FULL_DOCS])

Gets one property from one object in a scope.

The first argument specifies the variable in which to store the result. The second argument determines the scope from which to get the property. It must be one of the following:

GLOBAL
    Scope is unique and does not accept a name.

DIRECTORY
    Scope defaults to the current directory, but another directory (already processed by CMake) may be named by the full or relative path <dir>. Relative paths are treated as relative to the current source directory. See also the get_directory_property() command.

    Added in version 3.19: <dir> may reference a binary directory.

TARGET
    Scope must name one existing target. See also the get_target_property() command.

SOURCE
    Scope must name one source file. By default, the source file's property will be read from the current source directory's scope.

    Added in version 3.18: Directory scope can be overridden with one of the following sub-options:

DIRECTORY <dir>
    The source file property will be read from the <dir> directory's scope. CMake must already know about the directory, either by having added it through a call to add_subdirectory() or <dir> being the top level directory. Relative paths are treated as relative to the current source directory.

    Added in version 3.19: <dir> may reference a binary directory.

TARGET_DIRECTORY <target>
    The source file property will be read from the directory scope in which <target> was created (<target> must therefore already exist).

    See also the get_source_file_property() command.

INSTALL
    Added in version 3.1.

    Scope must name one installed file path.

TEST
    Scope must name one existing test. See also the get_test_property() command.

    Added in version 3.28: Directory scope can be overridden with the following sub-option:

DIRECTORY <dir>
    The test property will be read from the <dir> directory's scope. CMake must already know about the directory, either by having added it through a call to add_subdirectory() or <dir> being the top level directory. Relative paths are treated as relative to the current source directory. <dir> may reference a binary directory.

CACHE
    Scope must name one cache entry.

VARIABLE
    Scope is unique and does not accept a name.

    The required PROPERTY option is immediately followed by the name of the property to get. If the property is not set, the named <variable> will be unset in the calling scope upon return, although some properties support inheriting from a parent scope if defined to behave that way (see define_property()).

    If the SET option is given, the variable is set to a boolean value indicating whether the property has been set. If the DEFINED option is given, the variable is set to a boolean value indicating whether the property has been defined, such as with the define_property() command.

    If BRIEF_DOCS or FULL_DOCS is given, then the variable is set to a string containing documentation for the requested property. If documentation is requested for a property that has not been defined, NOTFOUND is returned.

    NOTE: The GENERATED source file property may be globally visible. See its documentation for details.

  See Also

•   define_property()

•   set_property()

  if

Conditionally execute a group of commands.

  Synopsis

    if(<condition>)
      <commands>
    elseif(<condition>) # optional block, can be repeated
      <commands>
    else()              # optional block
      <commands>
    endif()

Evaluates the condition argument of the if clause according to the Condition syntax described below. If the result is true, then the commands in the if block are executed. Otherwise, optional elseif blocks are processed in the same way. Finally, if no condition is true, commands in the optional else block are executed.

Per legacy, the else() and endif() commands admit an optional <condition> argument. If used, it must be a verbatim repeat of the argument of the opening if command.

  Condition Syntax

The following syntax applies to the condition argument of the if, elseif and while() clauses.

Compound conditions are evaluated in the following order of precedence:

1.  Parentheses.

2.  Unary tests such as COMMAND, POLICY, TARGET, TEST, EXISTS, IS_READABLE, IS_WRITABLE, IS_EXECUTABLE, IS_DIRECTORY, IS_SYMLINK, IS_ABSOLUTE, and DEFINED.

3.  Binary tests such as EQUAL, LESS, LESS_EQUAL, GREATER, GREATER_EQUAL, STREQUAL, STRLESS, STRLESS_EQUAL, STRGREATER, STRGREATER_EQUAL, VERSION_EQUAL, VERSION_LESS, VERSION_LESS_EQUAL, VERSION_GREATER, VERSION_GREATER_EQUAL, PATH_EQUAL, IN_LIST, IS_NEWER_THAN, and MATCHES.

4.  Unary logical operator NOT.

5.  Binary logical operators AND and OR, from left to right, without any short-circuit.

  Basic Expressions

if(<constant>)
    True if the constant is 1, ON, YES, TRUE, Y, or a non-zero number (including floating point numbers). False if the constant is 0, OFF, NO, FALSE, N, IGNORE, NOTFOUND, the empty string, or ends in the suffix -NOTFOUND. Named boolean constants are case-insensitive. If the argument is not one of these specific constants, it is treated as a variable or string (see Variable Expansion further below) and one of the following two forms applies.

if(<variable>)
    True if given a variable that is defined to a value that is not a false constant. False otherwise, including if the variable is undefined. Note that macro arguments are not variables. Environment Variables also cannot be tested this way, e.g. if(ENV{some_var}) will always evaluate to false.

if(<string>)
    A quoted string always evaluates to false unless:

•   The string's value is one of the true constants, or

•   in CMake versions prior to 4.0, policy CMP0054 is not set to NEW and the string's value happens to be a variable name that is affected by CMP0054's behavior.

  Logic Operators

if(NOT <condition>)
    True if the condition is not true.

if(<cond1> AND <cond2>)
    True if both conditions would be considered true individually.

if(<cond1> OR <cond2>)
    True if either condition would be considered true individually.

if((condition) AND (condition OR (condition)))
    The conditions inside the parenthesis are evaluated first and then the remaining condition is evaluated as in the other examples. Where there are nested parenthesis the innermost are evaluated as part of evaluating the condition that contains them.

  Existence Checks

if(COMMAND <command-name>)
    True if the given name is a command, macro or function that can be invoked.

if(POLICY <policy-id>)
    True if the given name is an existing policy (of the form CMP<NNNN>).

if(TARGET <target-name>)
    True if the given name is an existing logical target name created by a call to the add_executable(), add_library(), or add_custom_target() command that has already been invoked (in any directory).

if(TEST <test-name>)
    Added in version 3.3.

    True if the given name is an existing test name created by the add_test() command.

if(DEFINED <name>|CACHE{<name>}|ENV{<name>})
    True if a variable, cache variable or environment variable with given <name> is defined. The value of the variable does not matter. Note the following caveats:

•   Macro arguments are not variables.

•   It is not possible to test directly whether a <name> is a non-cache variable. The expression if(DEFINED someName) will evaluate to true if either a cache or non-cache variable someName exists. In comparison, the expression if(DEFINED CACHE{someName}) will only evaluate to true if a cache variable someName exists. Both expressions need to be tested if you need to know whether a non-cache variable exists: if(DEFINED someName AND NOT DEFINED CACHE{someName}).

    Added in version 3.14: Added support for CACHE{<name>} variables.

if(<variable|string> IN_LIST <variable>)
    Added in version 3.3.

    True if the given element is contained in the named list variable.

  File Operations

if(EXISTS <path-to-file-or-directory>)
    True if the named file or directory exists and is readable. Behavior is well-defined only for explicit full paths (a leading ~/ is not expanded as a home directory and is considered a relative path). Resolves symbolic links, i.e. if the named file or directory is a symbolic link, returns true if the target of the symbolic link exists.

    False if the given path is an empty string.

    NOTE: Prefer if(IS_READABLE) to check file readability. if(EXISTS) may be changed in the future to only check file existence.

if(IS_READABLE <path-to-file-or-directory>)
    Added in version 3.29.

    True if the named file or directory is readable. Behavior is well-defined only for explicit full paths (a leading ~/ is not expanded as a home directory and is considered a relative path). Resolves symbolic links, i.e. if the named file or directory is a symbolic link, returns true if the target of the symbolic link is readable.

    False if the given path is an empty string.

if(IS_WRITABLE <path-to-file-or-directory>)
    Added in version 3.29.

    True if the named file or directory is writable. Behavior is well-defined only for explicit full paths (a leading ~/ is not expanded as a home directory and is considered a relative path). Resolves symbolic links, i.e. if the named file or directory is a symbolic link, returns true if the target of the symbolic link is writable.

    False if the given path is an empty string.

if(IS_EXECUTABLE <path-to-file-or-directory>)
    Added in version 3.29.

    True if the named file or directory is executable. Behavior is well-defined only for explicit full paths (a leading ~/ is not expanded as a home directory and is considered a relative path). Resolves symbolic links, i.e. if the named file or directory is a symbolic link, returns true if the target of the symbolic link is executable.

    False if the given path is an empty string.

if(<file1> IS_NEWER_THAN <file2>)
    True if file1 is newer than file2 or if one of the two files doesn't exist. Behavior is well-defined only for full paths. If the file time stamps are exactly the same, an IS_NEWER_THAN comparison returns true, so that any dependent build operations will occur in the event of a tie. This includes the case of passing the same file name for both file1 and file2.

if(IS_DIRECTORY <path>)
    True if path is a directory. Behavior is well-defined only for full paths.

    False if the given path is an empty string.

if(IS_SYMLINK <path>)
    True if the given path is a symbolic link. Behavior is well-defined only for full paths.

if(IS_ABSOLUTE <path>)
    True if the given path is an absolute path. Note the following special cases:

•   An empty path evaluates to false.

•   On Windows hosts, any path that begins with a drive letter and colon (e.g. C:), a forward slash or a backslash will evaluate to true. This means a path like C:no\base\dir will evaluate to true, even though the non-drive part of the path is relative.

•   On non-Windows hosts, any path that begins with a tilde (~) evaluates to true.

  Comparisons

if(<variable|string> MATCHES <regex>)
    True if the given string or variable's value matches the given regular expression. See Regex Specification for regex format.

    Added in version 3.9: () groups are captured in CMAKE_MATCH_<n> variables.

if(<variable|string> LESS <variable|string>)
    True if the given string or variable's value parses as a real number (like a C double) and less than that on the right.

if(<variable|string> GREATER <variable|string>)
    True if the given string or variable's value parses as a real number (like a C double) and greater than that on the right.

if(<variable|string> EQUAL <variable|string>)
    True if the given string or variable's value parses as a real number (like a C double) and equal to that on the right.

if(<variable|string> LESS_EQUAL <variable|string>)
    Added in version 3.7.

    True if the given string or variable's value parses as a real number (like a C double) and less than or equal to that on the right.

if(<variable|string> GREATER_EQUAL <variable|string>)
    Added in version 3.7.

    True if the given string or variable's value parses as a real number (like a C double) and greater than or equal to that on the right.

if(<variable|string> STRLESS <variable|string>)
    True if the given string or variable's value is lexicographically less than the string or variable on the right.

if(<variable|string> STRGREATER <variable|string>)
    True if the given string or variable's value is lexicographically greater than the string or variable on the right.

if(<variable|string> STREQUAL <variable|string>)
    True if the given string or variable's value is lexicographically equal to the string or variable on the right.

if(<variable|string> STRLESS_EQUAL <variable|string>)
    Added in version 3.7.

    True if the given string or variable's value is lexicographically less than or equal to the string or variable on the right.

if(<variable|string> STRGREATER_EQUAL <variable|string>)
    Added in version 3.7.

    True if the given string or variable's value is lexicographically greater than or equal to the string or variable on the right.

  Version Comparisons

if(<variable|string> VERSION_LESS <variable|string>)
    Component-wise integer version number comparison (version format is major[.minor[.patch[.tweak]]], omitted components are treated as zero). Any non-integer version component or non-integer trailing part of a version component effectively truncates the string at that point.

if(<variable|string> VERSION_GREATER <variable|string>)
    Component-wise integer version number comparison (version format is major[.minor[.patch[.tweak]]], omitted components are treated as zero). Any non-integer version component or non-integer trailing part of a version component effectively truncates the string at that point.

if(<variable|string> VERSION_EQUAL <variable|string>)
    Component-wise integer version number comparison (version format is major[.minor[.patch[.tweak]]], omitted components are treated as zero). Any non-integer version component or non-integer trailing part of a version component effectively truncates the string at that point.

if(<variable|string> VERSION_LESS_EQUAL <variable|string>)
    Added in version 3.7.

    Component-wise integer version number comparison (version format is major[.minor[.patch[.tweak]]], omitted components are treated as zero). Any non-integer version component or non-integer trailing part of a version component effectively truncates the string at that point.

if(<variable|string> VERSION_GREATER_EQUAL <variable|string>)
    Added in version 3.7.

    Component-wise integer version number comparison (version format is major[.minor[.patch[.tweak]]], omitted components are treated as zero). Any non-integer version component or non-integer trailing part of a version component effectively truncates the string at that point.

  Path Comparisons

if(<variable|string> PATH_EQUAL <variable|string>)
    Added in version 3.24.

    Lexicographically compares two CMake paths component-by-component without accessing the filesystem. Only if every component of both paths match will the two paths compare equal. Multiple path separators are effectively collapsed into a single separator, but note that backslashes are not converted to forward slashes. No other path normalization is performed. Trailing slashes are preserved, thus /a/b and /a/b/ are not equal.

    Component-wise comparison is superior to string-based comparison due to the handling of multiple path separators. In the following example, the expression evaluates to true using PATH_EQUAL, but false with STREQUAL:

        # comparison is TRUE
        if ("/a//b/c" PATH_EQUAL "/a/b/c")
           ...
        endif()
        # comparison is FALSE
        if ("/a//b/c" STREQUAL "/a/b/c")
           ...
        endif()

    See cmake_path(COMPARE) for more details.

  Variable Expansion

The if command was written very early in CMake's history, predating the ${} variable evaluation syntax, and for convenience evaluates variables named by its arguments as shown in the above signatures. Note that normal variable evaluation with ${} applies before the if command even receives the arguments. Therefore code like

    set(var1 OFF)
    set(var2 "var1")
    if(${var2})

appears to the if command as

    if(var1)

and is evaluated according to the if(<variable>) case documented above. The result is OFF which is false. However, if we remove the ${} from the example then the command sees

    if(var2)

which is true because var2 is defined to var1 which is not a false constant.

Automatic evaluation applies in the other cases whenever the above-documented condition syntax accepts <variable|string>:

•   The left hand argument to MATCHES is first checked to see if it is a defined variable. If so, the variable's value is used, otherwise the original value is used.

•   If the left hand argument to MATCHES is missing it returns false without error

•   Both left and right hand arguments to LESS, GREATER, EQUAL, LESS_EQUAL, and GREATER_EQUAL, are independently tested to see if they are defined variables. If so, their defined values are used otherwise the original value is used.

•   Both left and right hand arguments to STRLESS, STRGREATER, STREQUAL, STRLESS_EQUAL, and STRGREATER_EQUAL are independently tested to see if they are defined variables. If so, their defined values are used otherwise the original value is used.

•   Both left and right hand arguments to VERSION_LESS, VERSION_GREATER, VERSION_EQUAL, VERSION_LESS_EQUAL, and VERSION_GREATER_EQUAL are independently tested to see if they are defined variables. If so, their defined values are used otherwise the original value is used.

•   The left hand argument to IN_LIST is tested to see if it is a defined variable. If so, the variable's value is used, otherwise the original value is used.

•   The right hand argument to NOT is tested to see if it is a boolean constant. If so, the value is used, otherwise it is assumed to be a variable and it is dereferenced.

•   The left and right hand arguments to AND and OR are independently tested to see if they are boolean constants. If so, they are used as such, otherwise they are assumed to be variables and are dereferenced.

    Changed in version 3.1: To prevent ambiguity, potential variable or keyword names can be specified in a Quoted Argument or a Bracket Argument. A quoted or bracketed variable or keyword will be interpreted as a string and not dereferenced or interpreted. See policy CMP0054.

    There is no automatic evaluation for environment or cache Variable References. Their values must be referenced as $ENV{<name>} or $CACHE{<name>} wherever the above-documented condition syntax accepts <variable|string>.

  See also

•   else()

•   elseif()

•   endif()

  include

Load and run CMake code from a file or module.

    include(<file|module> [OPTIONAL] [RESULT_VARIABLE <var>]
                          [NO_POLICY_SCOPE])

Loads and runs CMake code from the file given. Variable reads and writes access the scope of the caller (dynamic scoping). If OPTIONAL is present, then no error is raised if the file does not exist. If RESULT_VARIABLE is given the variable <var> will be set to the full filename which has been included or NOTFOUND if it failed.

If a module is specified instead of a file, the file with name <modulename>.cmake is searched first in CMAKE_MODULE_PATH, then in the CMake module directory. There is one exception to this: if the file which calls include() is located itself in the CMake builtin module directory, then first the CMake builtin module directory is searched and CMAKE_MODULE_PATH afterwards. See also policy CMP0017.

See the cmake_policy() command documentation for discussion of the NO_POLICY_SCOPE option.

  include_guard

Added in version 3.10.

Provides an include guard for the file currently being processed by CMake.

    include_guard([DIRECTORY|GLOBAL])

Sets up an include guard for the current CMake file (see the CMAKE_CURRENT_LIST_FILE variable documentation).

CMake will end its processing of the current file at the location of the include_guard command if the current file has already been processed for the applicable scope (see below). This provides functionality similar to the include guards commonly used in source headers or to the #pragma once directive. If the current file has been processed previously for the applicable scope, the effect is as though return() had been called. Do not call this command from inside a function being defined within the current file.

An optional argument specifying the scope of the guard may be provided. Possible values for the option are:

DIRECTORY
    The include guard applies within the current directory and below. The file will only be included once within this directory scope, but may be included again by other files outside of this directory (i.e. a parent directory or another directory not pulled in by add_subdirectory() or include() from the current file or its children).

GLOBAL
    The include guard applies globally to the whole build. The current file will only be included once regardless of the scope.

    If no arguments given, include_guard has the same scope as a variable, meaning that the include guard effect is isolated by the most recent function scope or current directory if no inner function scopes exist. In this case the command behavior is the same as:

        if(__CURRENT_FILE_VAR__)
          return()
        endif()
        set(__CURRENT_FILE_VAR__ TRUE)

  list

Operations on semicolon-separated lists.

  Synopsis

    Reading
      list(LENGTH <list> <out-var>)
      list(GET <list> <element index> [<index> ...] <out-var>)
      list(JOIN <list> <glue> <out-var>)
      list(SUBLIST <list> <begin> <length> <out-var>)
    Search
      list(FIND <list> <value> <out-var>)
    Modification
      list(APPEND <list> [<element>...])
      list(FILTER <list> {INCLUDE | EXCLUDE} REGEX <regex>)
      list(INSERT <list> <index> [<element>...])
      list(POP_BACK <list> [<out-var>...])
      list(POP_FRONT <list> [<out-var>...])
      list(PREPEND <list> [<element>...])
      list(REMOVE_ITEM <list> <value>...)
      list(REMOVE_AT <list> <index>...)
      list(REMOVE_DUPLICATES <list>)
      list(TRANSFORM <list> <ACTION> [...])
    Ordering
      list(REVERSE <list>)
      list(SORT <list> [...])

  Introduction

The list subcommands APPEND, INSERT, FILTER, PREPEND, POP_BACK, POP_FRONT, REMOVE_AT, REMOVE_ITEM, REMOVE_DUPLICATES, REVERSE and SORT may create new values for the list within the current CMake variable scope. Similar to the set() command, the list command creates new variable values in the current scope, even if the list itself is actually defined in a parent scope. To propagate the results of these operations upwards, use set() with PARENT_SCOPE, set() with CACHE INTERNAL, or some other means of value propagation.

NOTE: A list in cmake is a ; separated group of strings. To create a list, the set() command can be used. For example, set(var a b c d e) creates a list with a;b;c;d;e, and set(var "a b c d e") creates a string or a list with one item in it. (Note that macro arguments are not variables, and therefore cannot be used in LIST commands.)

Individual elements may not contain an unequal number of [ and ] characters, and may not end in a backslash (\). See semicolon-separated lists for details.

NOTE: When specifying index values, if <element index> is 0 or greater, it is indexed from the beginning of the list, with 0 representing the first list element. If <element index> is -1 or lesser, it is indexed from the end of the list, with -1 representing the last list element. Be careful when counting with negative indices: they do not start from 0. -0 is equivalent to 0, the first list element.

  Reading

list(LENGTH <list> <output variable>)
    Returns the list's length.

list(GET <list> <element index> [<element index> ...] <output variable>)
    Returns the list of elements specified by indices from the list.

list(JOIN <list> <glue> <output variable>)
    Added in version 3.12.

    Returns a string joining all list's elements using the glue string. To join multiple strings, which are not part of a list, use string(JOIN).

list(SUBLIST <list> <begin> <length> <output variable>)
    Added in version 3.12.

    Returns a sublist of the given list. If <length> is 0, an empty list will be returned. If <length> is -1 or the list is smaller than <begin>+<length> then the remaining elements of the list starting at <begin> will be returned.

  Search

list(FIND <list> <value> <output variable>)
    Returns the index of the element specified in the list or -1 if it wasn't found.

  Modification

list(APPEND <list> [<element> ...])
    Appends elements to the list. If no variable named <list> exists in the current scope its value is treated as empty and the elements are appended to that empty list.

list(FILTER <list> <INCLUDE|EXCLUDE> REGEX <regular_expression>)

    Added in version 3.6.

    Includes or removes items from the list that match the mode's pattern. In REGEX mode, items will be matched against the given regular expression.

    For more information on regular expressions look under string(REGEX).

list(INSERT <list> <element_index> <element> [<element> ...])
    Inserts elements to the list to the specified index. It is an error to specify an out-of-range index. Valid indexes are 0 to N where N is the length of the list, inclusive. An empty list has length 0. If no variable named <list> exists in the current scope its value is treated as empty and the elements are inserted in that empty list.

list(POP_BACK <list> [<out-var>...])
    Added in version 3.15.

    If no variable name is given, removes exactly one element. Otherwise, with N variable names provided, assign the last N elements' values to the given variables and then remove the last N values from <list>.

list(POP_FRONT <list> [<out-var>...])
    Added in version 3.15.

    If no variable name is given, removes exactly one element. Otherwise, with N variable names provided, assign the first N elements' values to the given variables and then remove the first N values from <list>.

list(PREPEND <list> [<element> ...])
    Added in version 3.15.

    Insert elements to the 0th position in the list. If no variable named <list> exists in the current scope its value is treated as empty and the elements are prepended to that empty list.

list(REMOVE_ITEM <list> <value> [<value> ...])
    Removes all instances of the given items from the list.

list(REMOVE_AT <list> <index> [<index> ...])
    Removes items at given indices from the list.

list(REMOVE_DUPLICATES <list>)
    Removes duplicated items in the list. The relative order of items is preserved, but if duplicates are encountered, only the first instance is preserved.

list(TRANSFORM <list> <ACTION> [<SELECTOR>] [OUTPUT_VARIABLE <output variable>])
    Added in version 3.12.

    Transforms the list by applying an <ACTION> to all or, by specifying a <SELECTOR>, to the selected elements of the list, storing the result in-place or in the specified output variable.

    NOTE: The TRANSFORM sub-command does not change the number of elements in the list. If a <SELECTOR> is specified, only some elements will be changed, the other ones will remain the same as before the transformation.

    <ACTION> specifies the action to apply to the elements of the list. The actions have exactly the same semantics as sub-commands of the string() command. <ACTION> must be one of the following:

APPEND, PREPEND
    Append, prepend specified value to each element of the list.

list(TRANSFORM <list> (APPEND|PREPEND) <value> ...)

TOLOWER, TOUPPER
    Convert each element of the list to lower, upper characters.

list(TRANSFORM <list> (TOLOWER|TOUPPER) ...)

STRIP
    Remove leading and trailing spaces from each element of the list.

list(TRANSFORM <list> STRIP ...)

GENEX_STRIP
    Strip any generator expressions from each element of the list.

list(TRANSFORM <list> GENEX_STRIP ...)

REPLACE
    Match the regular expression as many times as possible and substitute the replacement expression for the match for each element of the list (same semantic as string(REGEX REPLACE)).

list(TRANSFORM <list> REPLACE <regular_expression> <replace_expression> ...)

    <SELECTOR> determines which elements of the list will be transformed. Only one type of selector can be specified at a time. When given, <SELECTOR> must be one of the following:

AT  Specify a list of indexes.

        list(TRANSFORM <list> <ACTION> AT <index> [<index> ...] ...)

FOR Specify a range with, optionally, an increment used to iterate over the range.

        list(TRANSFORM <list> <ACTION> FOR <start> <stop> [<step>] ...)

REGEX
    Specify a regular expression. Only elements matching the regular expression will be transformed.

        list(TRANSFORM <list> <ACTION> REGEX <regular_expression> ...)

  Ordering

list(REVERSE <list>)
    Reverses the contents of the list in-place.

list(SORT <list> [COMPARE <compare>] [CASE <case>] [ORDER <order>])
    Sorts the list in-place alphabetically.

    Added in version 3.13: Added the COMPARE, CASE, and ORDER options.

    Added in version 3.18: Added the COMPARE NATURAL option.

    Use the COMPARE keyword to select the comparison method for sorting. The <compare> option should be one of:

STRING
    Sorts a list of strings alphabetically. This is the default behavior if the COMPARE option is not given.

FILE_BASENAME
    Sorts a list of pathnames of files by their basenames.

NATURAL
    Sorts a list of strings using natural order (see strverscmp(3) manual), i.e. such that contiguous digits are compared as whole numbers. For example: the following list 10.0 1.1 2.1 8.0 2.0 3.1 will be sorted as 1.1 2.0 2.1 3.1 8.0 10.0 if the NATURAL comparison is selected where it will be sorted as 1.1 10.0 2.0 2.1 3.1 8.0 with the STRING comparison.

    Use the CASE keyword to select a case sensitive or case insensitive sort mode. The <case> option should be one of:

SENSITIVE
    List items are sorted in a case-sensitive manner. This is the default behavior if the CASE option is not given.

INSENSITIVE
    List items are sorted case insensitively. The order of items which differ only by upper/lowercase is not specified.

    To control the sort order, the ORDER keyword can be given. The <order> option should be one of:

ASCENDING
    Sorts the list in ascending order. This is the default behavior when the ORDER option is not given.

DESCENDING
    Sorts the list in descending order.

  load_cache

Load in the values from another project's CMakeCache.txt cache file. This is useful for projects that depend on another project built in a separate directory tree.

This command has two signatures. The recommended signature is:

load_cache(<build-dir> READ_WITH_PREFIX <prefix> <entry>...)
    Loads the cache file from the specified <build-dir> build directory and retrieves the listed cache entries. The retrieved values are stored in local variables, with their names prefixed by the provided <prefix>. This only reads the cache values; it does not create or modify entries in the local project's cache.

READ_WITH_PREFIX <prefix>
    For each cache <entry>, a local variable is created using the specified <prefix> followed by the entry name.

    This signature can be also used in cmake -P script mode.

    The following signature of this command is strongly discouraged, but it is provided for backward compatibility:

load_cache(<build-dir> [EXCLUDE <entry>...] [INCLUDE_INTERNALS <entry>...])
    This form loads the cache file from the specified <build-dir> build directory and imports all its non-internal cache entries into the local project's cache as internal cache variables. By default, only non-internal entries are imported, unless the INCLUDE_INTERNALS option is used.

    The options are:

EXCLUDE <entry>...
    This option can be used to exclude a given list of non-internal cache entries when importing values.

INCLUDE_INTERNALS <entry>...
    This option can be used to provide a list of internal cache entries to include in addition to the non-internal cache entries.

    This signature can be used only in CMake projects. Script mode is not supported.

    NOTE: Instead of loading the outside project's cache file and manually accessing variables, a more robust and convenient approach is to use the export() command in the outside project, when available. This allows the project to provide its targets, configuration, or features in a structured and maintainable way, making integration simpler and less error-prone.

  Examples

Reading specific cache variables from another project and storing them as local variables:

    load_cache(
      path/to/other-project/build-dir
      READ_WITH_PREFIX prefix_
      OTHER_PROJECT_CACHE_VAR_1
      OTHER_PROJECT_CACHE_VAR_2
    )
    message(STATUS "${prefix_OTHER_PROJECT_CACHE_VAR_1")
    message(STATUS "${prefix_OTHER_PROJECT_CACHE_VAR_2")
    # Outputs:
    # -- some-value...
    # -- another-value...

Reading all non-internal cache entries from another project and storing them as internal cache variables using the obsolete signature:

    load_cache(path/to/other-project/build-dir)
    message(STATUS "${OTHER_PROJECT_CACHE_VAR_1")
    message(STATUS "${OTHER_PROJECT_CACHE_VAR_2")
    # Outputs:
    # -- some-value...
    # -- another-value...

Excluding specific non-internal cache entries and including internal ones using the obsolete signature:

    load_cache(
      path/to/other-project/build-dir
      EXCLUDE OTHER_PROJECT_CACHE_VAR_2
      INCLUDE_INTERNALS OTHER_PROJECT_INTERNAL_CACHE_VAR
    )
    message(STATUS "${OTHER_PROJECT_CACHE_VAR_1")
    message(STATUS "${OTHER_PROJECT_CACHE_VAR_2")
    message(STATUS "${OTHER_PROJECT_INTERNAL_CACHE_VAR}")
    # Outputs:
    # -- some-value...
    # --
    # -- some-internal-value...

  macro

Start recording a macro for later invocation as a command

    macro(<name> [<arg1> ...])
      <commands>
    endmacro()

Defines a macro named <name> that takes arguments named <arg1>, ... Commands listed after macro, but before the matching endmacro(), are not executed until the macro is invoked.

Per legacy, the endmacro() command admits an optional <name> argument. If used, it must be a verbatim repeat of the argument of the opening macro command.

See the cmake_policy() command documentation for the behavior of policies inside macros.

See the Macro vs Function section below for differences between CMake macros and functions.

  Invocation

The macro invocation is case-insensitive. A macro defined as

    macro(foo)
      <commands>
    endmacro()

can be invoked through any of

    foo()
    Foo()
    FOO()
    cmake_language(CALL foo)

and so on. However, it is strongly recommended to stay with the case chosen in the macro definition. Typically macros use all-lowercase names.

Added in version 3.18: The cmake_language(CALL ...) command can also be used to invoke the macro.

  Arguments

When a macro is invoked, the commands recorded in the macro are first modified by replacing formal parameters (${arg1}, ...) with the arguments passed, and then invoked as normal commands.

In addition to referencing the formal parameters you can reference the values ${ARGC} which will be set to the number of arguments passed into the macro as well as ${ARGV0}, ${ARGV1}, ${ARGV2}, ... which will have the actual values of the arguments passed in. This facilitates creating macros with optional arguments.

Furthermore, ${ARGV} holds the list of all arguments given to the macro and ${ARGN} holds the list of arguments past the last expected argument. Referencing to ${ARGV#} arguments beyond ${ARGC} have undefined behavior. Checking that ${ARGC} is greater than # is the only way to ensure that ${ARGV#} was passed to the function as an extra argument.

  Macro vs Function

The macro command is very similar to the function() command. Nonetheless, there are a few important differences.

In a function, ARGN, ARGC, ARGV and ARGV0, ARGV1, ... are true variables in the usual CMake sense. In a macro, they are not, they are string replacements much like the C preprocessor would do with a macro. This has a number of consequences, as explained in the Argument Caveats section below.

Another difference between macros and functions is the control flow. A function is executed by transferring control from the calling statement to the function body. A macro is executed as if the macro body were pasted in place of the calling statement. This has the consequence that a return() in a macro body does not just terminate execution of the macro; rather, control is returned from the scope of the macro call. To avoid confusion, it is recommended to avoid return() in macros altogether.

Unlike a function, the CMAKE_CURRENT_FUNCTION, CMAKE_CURRENT_FUNCTION_LIST_DIR, CMAKE_CURRENT_FUNCTION_LIST_FILE, CMAKE_CURRENT_FUNCTION_LIST_LINE variables are not set for a macro.

  Argument Caveats

Since ARGN, ARGC, ARGV, ARGV0 etc. are not variables, you will NOT be able to use commands like

    if(ARGV1) # ARGV1 is not a variable
    if(DEFINED ARGV2) # ARGV2 is not a variable
    if(ARGC GREATER 2) # ARGC is not a variable
    foreach(loop_var IN LISTS ARGN) # ARGN is not a variable

In the first case, you can use if(${ARGV1}). In the second and third case, the proper way to check if an optional variable was passed to the macro is to use if(${ARGC} GREATER 2). In the last case, you can use foreach(loop_var ${ARGN}) but this will skip empty arguments. If you need to include them, you can use

    set(list_var "${ARGN}")
    foreach(loop_var IN LISTS list_var)

Note that if you have a variable with the same name in the scope from which the macro is called, using unreferenced names will use the existing variable instead of the arguments. For example:

    macro(bar)
      foreach(arg IN LISTS ARGN)
        <commands>
      endforeach()
    endmacro()
    function(foo)
      bar(x y z)
    endfunction()
    foo(a b c)

Will loop over a;b;c and not over x;y;z as one might have expected. If you want true CMake variables and/or better CMake scope control you should look at the function command.

  See Also

•   cmake_parse_arguments()

•   endmacro()

  mark_as_advanced

Mark cmake cached variables as advanced.

    mark_as_advanced([CLEAR|FORCE] <var1> ...)

Sets the advanced/non-advanced state of the named cached variables.

An advanced variable will not be displayed in any of the cmake GUIs unless the show advanced option is on. In script mode, the advanced/non-advanced state has no effect.

If the keyword CLEAR is given then advanced variables are changed back to unadvanced. If the keyword FORCE is given then the variables are made advanced. If neither FORCE nor CLEAR is specified, new values will be marked as advanced, but if a variable already has an advanced/non-advanced state, it will not be changed.

Changed in version 3.17: Variables passed to this command which are not already in the cache are ignored. See policy CMP0102.

  math

Evaluate a mathematical expression.

    math(EXPR <variable> "<expression>" [OUTPUT_FORMAT <format>])

Evaluates a mathematical <expression> and sets <variable> to the resulting value. The result of the expression must be representable as a 64-bit signed integer. Floating point inputs are invalid e.g. 1.1 * 10. Non-integer results e.g. 3 / 2 are truncated.

The mathematical expression must be given as a string (i.e. enclosed in double quotation marks). An example is "5 * (10 + 13)". Supported operators are +, -, *, /, %, |, &, ^, ~, <<, >>, and (...); they have the same meaning as in C code.

Added in version 3.13: Hexadecimal numbers are recognized when prefixed with 0x, as in C code.

Added in version 3.13: The result is formatted according to the option OUTPUT_FORMAT, where <format> is one of

HEXADECIMAL
    Hexadecimal notation as in C code, i. e. starting with "0x".

DECIMAL
    Decimal notation. Which is also used if no OUTPUT_FORMAT option is specified.

    For example

        math(EXPR value "100 * 0xA" OUTPUT_FORMAT DECIMAL)      # value is set to "1000"
        math(EXPR value "100 * 0xA" OUTPUT_FORMAT HEXADECIMAL)  # value is set to "0x3e8"

  message

Log a message.

  Synopsis

    General messages
      message([<mode>] "message text" ...)
    Reporting checks
      message(<checkState> "message text" ...)
    Configure Log
      message(CONFIGURE_LOG <text>...)

  General messages

    message([<mode>] "message text" ...)

Record the specified message text in the log. If more than one message string is given, they are concatenated into a single message with no separator between the strings.

The optional <mode> keyword determines the type of message, which influences the way the message is handled:

FATAL_ERROR
    CMake Error, stop processing and generation.

    The cmake(1) executable will return a non-zero exit code.

SEND_ERROR
    CMake Error, continue processing, but skip generation.

WARNING
    CMake Warning, continue processing.

AUTHOR_WARNING
    CMake Warning (dev), continue processing.

DEPRECATION
    CMake Deprecation Error or Warning if variable CMAKE_ERROR_DEPRECATED or CMAKE_WARN_DEPRECATED is enabled, respectively, else no message.

(none) or NOTICE
    Important message printed to stderr to attract user's attention.

STATUS
    The main interesting messages that project users might be interested in. Ideally these should be concise, no more than a single line, but still informative.

VERBOSE
    Detailed informational messages intended for project users. These messages should provide additional details that won't be of interest in most cases, but which may be useful to those building the project when they want deeper insight into what's happening.

DEBUG
    Detailed informational messages intended for developers working on the project itself as opposed to users who just want to build it. These messages will not typically be of interest to other users building the project and will often be closely related to internal implementation details.

TRACE
    Fine-grained messages with very low-level implementation details. Messages using this log level would normally only be temporary and would expect to be removed before releasing the project, packaging up the files, etc.

    Added in version 3.15: Added the NOTICE, VERBOSE, DEBUG, and TRACE levels.

    The CMake command-line tool displays STATUS to TRACE messages on stdout with the message preceded by two hyphens and a space. All other message types are sent to stderr and are not prefixed with hyphens. The CMake GUI displays all messages in its log area. The curses interface shows STATUS to TRACE messages one at a time on a status line and other messages in an interactive pop-up box. The --log-level command-line option to each of these tools can be used to control which messages will be shown.

    Added in version 3.17: To make a log level persist between CMake runs, the CMAKE_MESSAGE_LOG_LEVEL variable can be set instead. Note that the command line option takes precedence over the cache variable.

    Added in version 3.16: Messages of log levels NOTICE and below will have each line preceded by the content of the CMAKE_MESSAGE_INDENT variable (converted to a single string by concatenating its list items). For STATUS to TRACE messages, this indenting content will be inserted after the hyphens.

    Added in version 3.17: Messages of log levels NOTICE and below can also have each line preceded with context of the form [some.context.example]. The content between the square brackets is obtained by converting the CMAKE_MESSAGE_CONTEXT list variable to a dot-separated string. The message context will always appear before any indenting content but after any automatically added leading hyphens. By default, message context is not shown, it has to be explicitly enabled by giving the cmake --log-context command-line option or by setting the CMAKE_MESSAGE_CONTEXT_SHOW variable to true. See the CMAKE_MESSAGE_CONTEXT documentation for usage examples.

    CMake Warning and Error message text displays using a simple markup language. Non-indented text is formatted in line-wrapped paragraphs delimited by newlines. Indented text is considered pre-formatted.

  Reporting checks

Added in version 3.17.

A common pattern in CMake output is a message indicating the start of some sort of check, followed by another message reporting the result of that check. For example:

    message(STATUS "Looking for someheader.h")
    #... do the checks, set checkSuccess with the result
    if(checkSuccess)
      message(STATUS "Looking for someheader.h - found")
    else()
      message(STATUS "Looking for someheader.h - not found")
    endif()

This can be more robustly and conveniently expressed using the CHECK_... keyword form of the message() command:

    message(<checkState> "message" ...)

where <checkState> must be one of the following:

CHECK_START
    Record a concise message about the check about to be performed.

CHECK_PASS
    Record a successful result for a check.

CHECK_FAIL
    Record an unsuccessful result for a check.

    When recording a check result, the command repeats the message from the most recently started check for which no result has yet been reported, then some separator characters and then the message text provided after the CHECK_PASS or CHECK_FAIL keyword. Check messages are always reported at STATUS log level.

    Checks may be nested and every CHECK_START should have exactly one matching CHECK_PASS or CHECK_FAIL. The CMAKE_MESSAGE_INDENT variable can also be used to add indenting to nested checks if desired. For example:

        message(CHECK_START "Finding my things")
        list(APPEND CMAKE_MESSAGE_INDENT "  ")
        unset(missingComponents)
        message(CHECK_START "Finding partA")
        # ... do check, assume we find A
        message(CHECK_PASS "found")
        message(CHECK_START "Finding partB")
        # ... do check, assume we don't find B
        list(APPEND missingComponents B)
        message(CHECK_FAIL "not found")
        list(POP_BACK CMAKE_MESSAGE_INDENT)
        if(missingComponents)
          message(CHECK_FAIL "missing components: ${missingComponents}")
        else()
          message(CHECK_PASS "all components found")
        endif()

    Output from the above would appear something like the following:

        -- Finding my things
        --   Finding partA
        --   Finding partA - found
        --   Finding partB
        --   Finding partB - not found
        -- Finding my things - missing components: B

  Configure Log

Added in version 3.26.

    message(CONFIGURE_LOG <text>...)

Record a configure-log message event with the specified <text>. By convention, if the text contains more than one line, the first line should be a summary of the event.

This mode is intended to record the details of a system inspection check or other one-time operation guarded by a cache entry, but that is not performed using try_compile() or try_run(), which automatically log their details. Projects should avoid calling it every time CMake runs. For example:

    if (NOT DEFINED MY_CHECK_RESULT)
      # Print check summary in configure output.
      message(CHECK_START "My Check")
      # ... perform system inspection, e.g., with execute_process ...
      # Cache the result so we do not run the check again.
      set(MY_CHECK_RESULT "${MY_CHECK_RESULT}" CACHE INTERNAL "My Check")
      # Record the check details in the cmake-configure-log.
      message(CONFIGURE_LOG
        "My Check Result: ${MY_CHECK_RESULT}\n"
        "${details}"
      )
      # Print check result in configure output.
      if(MY_CHECK_RESULT)
        message(CHECK_PASS "passed")
      else()
        message(CHECK_FAIL "failed")
      endif()
    endif()

If no project is currently being configured, such as in cmake -P script mode, this command does nothing.

  See Also

•   cmake_language(GET_MESSAGE_LOG_LEVEL)

  option

Provide a boolean option that the user can optionally select.

    option(<variable> "<help_text>" [value])

If no initial <value> is provided, boolean OFF is the default value. If <variable> is already set as a normal or cache variable, then the command does nothing (see policy CMP0077).

For options that depend on the values of other options, see the module help for CMakeDependentOption.

In CMake project mode, a boolean cache variable is created with the option value. In CMake script mode, a boolean variable is set with the option value.

  return

Return from a file, directory or function.

    return([PROPAGATE <var-name>...])

When this command is encountered in an included file (via include() or find_package()), it causes processing of the current file to stop and control is returned to the including file. If it is encountered in a file which is not included by another file, e.g. a CMakeLists.txt, deferred calls scheduled by cmake_language(DEFER) are invoked and control is returned to the parent directory if there is one.

If return() is called in a function, control is returned to the caller of that function. Note that a macro(), unlike a function(), is expanded in place and therefore cannot handle return().

Policy CMP0140 controls the behavior regarding the arguments of the command. All arguments are ignored unless that policy is set to NEW.

PROPAGATE
    Added in version 3.25.

    This option sets or unsets the specified variables in the parent directory or function caller scope. This is equivalent to set(PARENT_SCOPE) or unset(PARENT_SCOPE) commands, except for the way it interacts with the block() command, as described below.

    The PROPAGATE option can be very useful in conjunction with the block() command. A return will propagate the specified variables through any enclosing block scopes created by the block() commands. Inside a function, this ensures the variables are propagated to the function's caller, regardless of any blocks within the function. If not inside a function, it ensures the variables are propagated to the parent file or directory scope. For example:

    CMakeLists.txt

        cmake_minimum_required(VERSION 3.25)
        project(example)
        set(var1 "top-value")
        block(SCOPE_FOR VARIABLES)
          add_subdirectory(subDir)
          # var1 has the value "block-nested"
        endblock()
        # var1 has the value "top-value"

    subDir/CMakeLists.txt

        function(multi_scopes result_var1 result_var2)
          block(SCOPE_FOR VARIABLES)
            # This would only propagate out of the immediate block, not to
            # the caller of the function.
            #set(${result_var1} "new-value" PARENT_SCOPE)
            #unset(${result_var2} PARENT_SCOPE)
            # This propagates the variables through the enclosing block and
            # out to the caller of the function.
            set(${result_var1} "new-value")
            unset(${result_var2})
            return(PROPAGATE ${result_var1} ${result_var2})
          endblock()
        endfunction()
        set(var1 "some-value")
        set(var2 "another-value")
        multi_scopes(var1 var2)
        # Now var1 will hold "new-value" and var2 will be unset
        block(SCOPE_FOR VARIABLES)
          # This return() will set var1 in the directory scope that included us
          # via add_subdirectory(). The surrounding block() here does not limit
          # propagation to the current file, but the block() in the parent
          # directory scope does prevent propagation going any further.
          set(var1 "block-nested")
          return(PROPAGATE var1)
        endblock()

  See Also

•   block()

•   function()

  separate_arguments

Parse command-line arguments into a semicolon-separated list.

    separate_arguments(<variable> <mode> [PROGRAM [SEPARATE_ARGS]] <args>)

Parses a space-separated string <args> into a list of items, and stores this list in semicolon-separated standard form in <variable>.

This function is intended for parsing command-line arguments. The entire command line must be passed as one string in the argument <args>.

The exact parsing rules depend on the operating system. They are specified by the <mode> argument which must be one of the following keywords:

UNIX_COMMAND
    Arguments are separated by unquoted whitespace. Both single-quote and double-quote pairs are respected. A backslash escapes the next literal character (\" is "); there are no special escapes (\n is just n).

WINDOWS_COMMAND
    A Windows command-line is parsed using the same syntax the runtime library uses to construct argv at startup. It separates arguments by whitespace that is not double-quoted. Backslashes are literal unless they precede double-quotes. See the MSDN article Parsing C Command-Line Arguments for details.

NATIVE_COMMAND
    Added in version 3.9.

    Proceeds as in WINDOWS_COMMAND mode if the host system is Windows. Otherwise proceeds as in UNIX_COMMAND mode.

PROGRAM
    Added in version 3.19.

    The first item in <args> is assumed to be an executable and will be searched in the system search path or left as a full path. If not found, <variable> will be empty. Otherwise, <variable> is a list of 2 elements:

0.  Absolute path of the program

1.  Any command-line arguments present in <args> as a string

    For example:

        separate_arguments (out UNIX_COMMAND PROGRAM "cc -c main.c")

•   First element of the list: /path/to/cc

•   Second element of the list: " -c main.c"

SEPARATE_ARGS
    When this sub-option of PROGRAM option is specified, command-line arguments will be split as well and stored in <variable>.

    For example:

        separate_arguments (out UNIX_COMMAND PROGRAM SEPARATE_ARGS "cc -c main.c")

    The contents of out will be: /path/to/cc;-c;main.c

        separate_arguments(<var>)

    Convert the value of <var> to a semi-colon separated list. All spaces are replaced with ';'. This helps with generating command lines.

  set

Set a normal, cache, or environment variable to a given value. See the cmake-language(7) variables documentation for the scopes and interaction of normal variables and cache entries.

Signatures of this command that specify a <value>... placeholder expect zero or more arguments. Multiple arguments will be joined as a semicolon-separated list to form the actual variable value to be set.

  Set Normal Variable

set(<variable> <value>... [PARENT_SCOPE])
    Set or unset <variable> in the current function or directory scope:

•   If at least one <value>... is given, set the variable to that value.

•   If no value is given, unset the variable. This is equivalent to unset(<variable>).

    If the PARENT_SCOPE option is given the variable will be set in the scope above the current scope. Each new directory or function() command creates a new scope. A scope can also be created with the block() command. set(PARENT_SCOPE) will set the value of a variable into the parent directory, calling function, or encompassing scope (whichever is applicable to the case at hand). The previous state of the variable's value stays the same in the current scope (e.g., if it was undefined before, it is still undefined and if it had a value, it is still that value).

    The block(PROPAGATE) and return(PROPAGATE) commands can be used as an alternate method to the set(PARENT_SCOPE) and unset(PARENT_SCOPE) commands to update the parent scope.

    NOTE: When evaluating Variable References of the form ${VAR}, CMake first searches for a normal variable with that name. If no such normal variable exists, CMake will then search for a cache entry with that name. Because of this, unsetting a normal variable can expose a cache variable that was previously hidden. To force a variable reference of the form ${VAR} to return an empty string, use set(<variable> ""), which clears the normal variable but leaves it defined.

  Set Cache Entry

set(<variable> <value>... CACHE <type> <docstring> [FORCE])
    Sets the given cache <variable> (cache entry). Since cache entries are meant to provide user-settable values this does not overwrite existing cache entries by default. Use the FORCE option to overwrite existing entries.

    The <type> must be specified as one of:

BOOL
    Boolean ON/OFF value. cmake-gui(1) offers a checkbox.

FILEPATH
    Path to a file on disk. cmake-gui(1) offers a file dialog.

PATH
    Path to a directory on disk. cmake-gui(1) offers a file dialog.

STRING
    A line of text. cmake-gui(1) offers a text field or a drop-down selection if the STRINGS cache entry property is set.

INTERNAL
    A line of text. cmake-gui(1) does not show internal entries. They may be used to store variables persistently across runs. Use of this type implies FORCE.

    The <docstring> must be specified as a line of text providing a quick summary of the option for presentation to cmake-gui(1) users.

    If the cache entry does not exist prior to the call or the FORCE option is given then the cache entry will be set to the given value.

    NOTE: The content of the cache variable will not be directly accessible if a normal variable of the same name already exists (see rules of variable evaluation). If policy CMP0126 is set to OLD, any normal variable binding in the current scope will be removed.

    It is possible for the cache entry to exist prior to the call but have no type set if it was created on the cmake(1) command line by a user through the -D<var>=<value> option without specifying a type. In this case the set command will add the type. Furthermore, if the <type> is PATH or FILEPATH and the <value> provided on the command line is a relative path, then the set command will treat the path as relative to the current working directory and convert it to an absolute path.

  Set Environment Variable

set(ENV{<variable>} [<value>])
    Sets an Environment Variable to the given value. Subsequent calls of $ENV{<variable>} will return this new value.

    This command affects only the current CMake process, not the process from which CMake was called, nor the system environment at large, nor the environment of subsequent build or test processes.

    If no argument is given after ENV{<variable>} or if <value> is an empty string, then this command will clear any existing value of the environment variable.

    Arguments after <value> are ignored. If extra arguments are found, then an author warning is issued.

  See Also

•   unset()

  set_directory_properties

Set properties of the current directory and subdirectories.

    set_directory_properties(PROPERTIES <prop1> <value1> [<prop2> <value2>] ...)

Sets properties of the current directory and its subdirectories in key-value pairs.

See also the set_property(DIRECTORY) command.

See Properties on Directories for the list of properties known to CMake and their individual documentation for the behavior of each property.

  See Also

•   define_property()

•   get_directory_property()

•   the more general set_property() command

  set_property

Set a named property in a given scope.

    set_property(<GLOBAL                      |
                  DIRECTORY [<dir>]           |
                  TARGET    [<target1> ...]   |
                  SOURCE    [<src1> ...]
                            [DIRECTORY <dirs> ...]
                            [TARGET_DIRECTORY <targets> ...] |
                  INSTALL   [<file1> ...]     |
                  TEST      [<test1> ...]
                            [DIRECTORY <dir>] |
                  CACHE     [<entry1> ...]    >
                 [APPEND] [APPEND_STRING]
                 PROPERTY <name> [<value1> ...])

Sets one property on zero or more objects of a scope.

The first argument determines the scope in which the property is set. It must be one of the following:

GLOBAL
    Scope is unique and does not accept a name.

DIRECTORY
    Scope defaults to the current directory but other directories (already processed by CMake) may be named by full or relative path. Relative paths are treated as relative to the current source directory. See also the set_directory_properties() command.

    Added in version 3.19: <dir> may reference a binary directory.

TARGET
    Scope may name zero or more existing targets. See also the set_target_properties() command.

    Alias Targets do not support setting target properties.

SOURCE
    Scope may name zero or more source files. By default, source file properties are only visible to targets added in the same directory (CMakeLists.txt).

    Added in version 3.18: Visibility can be set in other directory scopes using one or both of the following sub-options:

DIRECTORY <dirs>...
    The source file property will be set in each of the <dirs> directories' scopes. CMake must already know about each of these directories, either by having added them through a call to add_subdirectory() or it being the top level source directory. Relative paths are treated as relative to the current source directory.

    Added in version 3.19: <dirs> may reference a binary directory.

TARGET_DIRECTORY <targets>...
    The source file property will be set in each of the directory scopes where any of the specified <targets> were created (the <targets> must therefore already exist).

    See also the set_source_files_properties() command.

INSTALL
    Added in version 3.1.

    Scope may name zero or more installed file paths. These are made available to CPack to influence deployment.

    Both the property key and value may use generator expressions. Specific properties may apply to installed files and/or directories.

    Path components have to be separated by forward slashes, must be normalized and are case sensitive.

    To reference the installation prefix itself with a relative path use ..

    Currently installed file properties are only defined for the WIX generator where the given paths are relative to the installation prefix.

TEST
    Scope is limited to the directory the command is called in. It may name zero or more existing tests. See also command set_tests_properties().

    Test property values may be specified using generator expressions for tests created by the add_test(NAME) signature.

    Added in version 3.28: Visibility can be set in other directory scopes using the following sub-option:

DIRECTORY <dir>
    The test property will be set in the <dir> directory's scope. CMake must already know about this directory, either by having added it through a call to add_subdirectory() or it being the top level source directory. Relative paths are treated as relative to the current source directory. <dir> may reference a binary directory.

CACHE
    Scope must name zero or more existing cache entries.

    The required PROPERTY option is immediately followed by the name of the property to set. Remaining arguments are used to compose the property value in the form of a semicolon-separated list.

    If the APPEND option is given the list is appended to any existing property value (except that empty values are ignored and not appended). If the APPEND_STRING option is given the string is appended to any existing property value as string, i.e. it results in a longer string and not a list of strings. When using APPEND or APPEND_STRING with a property defined to support INHERITED behavior (see define_property()), no inheriting occurs when finding the initial value to append to. If the property is not already directly set in the nominated scope, the command will behave as though APPEND or APPEND_STRING had not been given.

    NOTE: The GENERATED source file property may be globally visible. See its documentation for details.

  See Also

•   define_property()

•   get_property()

•   The cmake-properties(7) manual for a list of properties in each scope.

  site_name

Set the given variable to the name of the computer.

    site_name(variable)

On UNIX-like platforms, if the variable HOSTNAME is set, its value will be executed as a command expected to print out the host name, much like the hostname command-line tool.

  string

String operations.

  Synopsis

    Search and Replace
      string(FIND <string> <substring> <out-var> [...])
      string(REPLACE <match-string> <replace-string> <out-var> <input>...)
      string(REGEX MATCH <match-regex> <out-var> <input>...)
      string(REGEX MATCHALL <match-regex> <out-var> <input>...)
      string(REGEX REPLACE <match-regex> <replace-expr> <out-var> <input>...)
    Manipulation
      string(APPEND <string-var> [<input>...])
      string(PREPEND <string-var> [<input>...])
      string(CONCAT <out-var> [<input>...])
      string(JOIN <glue> <out-var> [<input>...])
      string(TOLOWER <string> <out-var>)
      string(TOUPPER <string> <out-var>)
      string(LENGTH <string> <out-var>)
      string(SUBSTRING <string> <begin> <length> <out-var>)
      string(STRIP <string> <out-var>)
      string(GENEX_STRIP <string> <out-var>)
      string(REPEAT <string> <count> <out-var>)
    Comparison
      string(COMPARE <op> <string1> <string2> <out-var>)
    Hashing
      string(<HASH> <out-var> <input>)
    Generation
      string(ASCII <number>... <out-var>)
      string(HEX <string> <out-var>)
      string(CONFIGURE <string> <out-var> [...])
      string(MAKE_C_IDENTIFIER <string> <out-var>)
      string(RANDOM [<option>...] <out-var>)
      string(TIMESTAMP <out-var> [<format string>] [UTC])
      string(UUID <out-var> ...)
    JSON
      string(JSON <out-var> [ERROR_VARIABLE <error-var>]
             {GET | TYPE | LENGTH | REMOVE}
             <json-string> <member|index> [<member|index> ...])
      string(JSON <out-var> [ERROR_VARIABLE <error-var>]
             MEMBER <json-string>
             [<member|index> ...] <index>)
      string(JSON <out-var> [ERROR_VARIABLE <error-var>]
             SET <json-string>
             <member|index> [<member|index> ...] <value>)
      string(JSON <out-var> [ERROR_VARIABLE <error-var>]
             EQUAL <json-string1> <json-string2>)

  Search and Replace

  Search and Replace With Plain Strings

string(FIND <string> <substring> <output_variable> [REVERSE])
    Return the position where the given <substring> was found in the supplied <string>. If the REVERSE flag was used, the command will search for the position of the last occurrence of the specified <substring>. If the <substring> is not found, a position of -1 is returned.

    The string(FIND) subcommand treats all strings as ASCII-only characters. The index stored in <output_variable> will also be counted in bytes, so strings containing multi-byte characters may lead to unexpected results.

string(REPLACE <match_string> <replace_string> <output_variable> <input> [<input>...])
    Replace all occurrences of <match_string> in the <input> with <replace_string> and store the result in the <output_variable>.

  Search and Replace With Regular Expressions

string(REGEX MATCH <regular_expression> <output_variable> <input> [<input>...])
    Match the <regular_expression> once and store the match in the <output_variable>. All <input> arguments are concatenated before matching. Regular expressions are specified in the subsection just below.

string(REGEX MATCHALL <regular_expression> <output_variable> <input> [<input>...])
    Match the <regular_expression> as many times as possible and store the matches in the <output_variable> as a list. All <input> arguments are concatenated before matching.

string(REGEX REPLACE <regular_expression> <replacement_expression> <output_variable> <input> [<input>...])
    Match the <regular_expression> as many times as possible and substitute the <replacement_expression> for the match in the output. All <input> arguments are concatenated before matching.

    The <replacement_expression> may refer to parenthesis-delimited subexpressions of the match using \1, \2, ..., \9. Note that two backslashes (\\1) are required in CMake code to get a backslash through argument parsing.

  Regex Specification

The following characters have special meaning in regular expressions:

^   Matches at beginning of input

$   Matches at end of input

.   Matches any single character

\<char>
    Matches the single character specified by <char>. Use this to match special regex characters, e.g. \. for a literal . or \\ for a literal backslash \. Escaping a non-special character is unnecessary but allowed, e.g. \a matches a.

[ ] Matches any character(s) inside the brackets. To match a literal ], make it the first character, e.g., []ab].

[^ ]
    Matches any character(s) not inside the brackets. To not match a literal ], make it the first character, e.g., [^]ab].

-   Inside brackets, specifies an inclusive range between characters on either side, e.g., [a-f] is [abcdef]. To match a literal - using brackets, make it the first or the last character, e.g., [+*/-] matches basic mathematical operators.

*   Matches preceding pattern zero or more times

+   Matches preceding pattern one or more times

?   Matches preceding pattern zero or once only

|   Matches a pattern on either side of the |

()  Saves a matched subexpression, which can be referenced in the REGEX REPLACE operation.

    Added in version 3.9: All regular expression-related commands, including e.g. if(MATCHES), save subgroup matches in the variables CMAKE_MATCH_<n> for <n> 0..9.

    *, + and ? have higher precedence than concatenation. | has lower precedence than concatenation. This means that the regular expression ^ab+d$ matches abbd but not ababd, and the regular expression ^(ab|cd)$ matches ab but not abd.

    CMake language Escape Sequences such as \t, \r, \n, and \\ may be used to construct literal tabs, carriage returns, newlines, and backslashes (respectively) to pass in a regex. For example:

•   The quoted argument "[ \t\r\n]" specifies a regex that matches any single whitespace character.

•   The quoted argument "[/\\]" specifies a regex that matches a single forward slash / or backslash \.

•   The quoted argument "[A-Za-z0-9_]" specifies a regex that matches any single "word" character in the C locale.

•   The quoted argument "\\(\\a\\+b\\)" specifies a regex that matches the exact string (a+b). Each \\ is parsed in a quoted argument as just \, so the regex itself is actually \(\a\+\b\). This can alternatively be specified in a Bracket Argument without having to escape the backslashes, e.g. [[\(\a\+\b\)]].

  Manipulation

string(APPEND <string_variable> [<input>...])
    Added in version 3.4.

    Append all the <input> arguments to the string.

string(PREPEND <string_variable> [<input>...])
    Added in version 3.10.

    Prepend all the <input> arguments to the string.

string(CONCAT <output_variable> [<input>...])
    Concatenate all the <input> arguments together and store the result in the named <output_variable>.

string(JOIN <glue> <output_variable> [<input>...])
    Added in version 3.12.

    Join all the <input> arguments together using the <glue> string and store the result in the named <output_variable>.

    To join a list's elements, prefer to use the JOIN operator from the list() command. This allows for the elements to have special characters like ; in them.

string(TOLOWER <string> <output_variable>)
    Convert <string> to lower characters.

string(TOUPPER <string> <output_variable>)
    Convert <string> to upper characters.

string(LENGTH <string> <output_variable>)
    Store in an <output_variable> a given string's length in bytes. Note that this means if <string> contains multi-byte characters, the result stored in <output_variable> will not be the number of characters.

string(SUBSTRING <string> <begin> <length> <output_variable>)
    Store in an <output_variable> a substring of a given <string>. If <length> is -1 the remainder of the string starting at <begin> will be returned.

    Changed in version 3.2: If <string> is shorter than <length> then the end of the string is used instead. Previous versions of CMake reported an error in this case.

    Both <begin> and <length> are counted in bytes, so care must be exercised if <string> could contain multi-byte characters.

string(STRIP <string> <output_variable>)
    Store in an <output_variable> a substring of a given <string> with leading and trailing spaces removed.

string(GENEX_STRIP <string> <output_variable>)
    Added in version 3.1.

    Strip any generator expressions from the input <string> and store the result in the <output_variable>.

string(REPEAT <string> <count> <output_variable>)
    Added in version 3.15.

    Produce the output string as the input <string> repeated <count> times.

  Comparison

string(COMPARE LESS <string1> <string2> <output_variable>)

string(COMPARE GREATER <string1> <string2> <output_variable>)

string(COMPARE EQUAL <string1> <string2> <output_variable>)

string(COMPARE NOTEQUAL <string1> <string2> <output_variable>)

string(COMPARE LESS_EQUAL <string1> <string2> <output_variable>)

string(COMPARE GREATER_EQUAL <string1> <string2> <output_variable>)
    Compare the strings and store true or false in the <output_variable>.

    Added in version 3.7: Added the LESS_EQUAL and GREATER_EQUAL options.

  Hashing

string(<HASH> <output_variable> <input>)
    Compute a cryptographic hash of the <input> string. The supported <HASH> algorithm names are:

MD5 Message-Digest Algorithm 5, RFC 1321.

SHA1
    US Secure Hash Algorithm 1, RFC 3174.

SHA224
    US Secure Hash Algorithms, RFC 4634.

SHA256
    US Secure Hash Algorithms, RFC 4634.

SHA384
    US Secure Hash Algorithms, RFC 4634.

SHA512
    US Secure Hash Algorithms, RFC 4634.

SHA3_224
    Keccak SHA-3.

SHA3_256
    Keccak SHA-3.

SHA3_384
    Keccak SHA-3.

SHA3_512
    Keccak SHA-3.

    Added in version 3.8: Added the SHA3_* hash algorithms.

  Generation

string(ASCII <number> [<number> ...] <output_variable>)
    Convert all numbers into corresponding ASCII characters.

string(HEX <string> <output_variable>)
    Added in version 3.18.

    Convert each byte in the input <string> to its hexadecimal representation and store the concatenated hex digits in the <output_variable>. Letters in the output (a through f) are in lowercase.

string(CONFIGURE <string> <output_variable> [@ONLY] [ESCAPE_QUOTES])
    Transform a <string> like configure_file() transforms a file.

string(MAKE_C_IDENTIFIER <string> <output_variable>)
    Convert each non-alphanumeric character in the input <string> to an underscore and store the result in the <output_variable>. If the first character of the <string> is a digit, an underscore will also be prepended to the result.

string(RANDOM [LENGTH <length>] [ALPHABET <alphabet>] [RANDOM_SEED <seed>] <output_variable>)
    Return a random string of given <length> consisting of characters from the given <alphabet>. Default length is 5 characters and default alphabet is all numbers and upper and lower case letters. If an integer RANDOM_SEED is given, its value will be used to seed the random number generator.

string(TIMESTAMP <output_variable> [<format_string>] [UTC])
    Write a string representation of the current date and/or time to the <output_variable>.

    If the command is unable to obtain a timestamp, the <output_variable> will be set to the empty string "".

    The optional UTC flag requests the current date/time representation to be in Coordinated Universal Time (UTC) rather than local time.

    The optional <format_string> may contain the following format specifiers:

%%  Added in version 3.8.

    A literal percent sign (%).

%d  The day of the current month (01-31).

%H  The hour on a 24-hour clock (00-23).

%I  The hour on a 12-hour clock (01-12).

%j  The day of the current year (001-366).

%m  The month of the current year (01-12).

%b  Added in version 3.7.

    Abbreviated month name (e.g. Oct).

%B  Added in version 3.10.

    Full month name (e.g. October).

%M  The minute of the current hour (00-59).

%s  Added in version 3.6.

    Seconds since midnight (UTC) 1-Jan-1970 (UNIX time).

%S  The second of the current minute. 60 represents a leap second. (00-60)

%f  Added in version 3.23.

    The microsecond of the current second (000000-999999).

%U  The week number of the current year (00-53).

%V  Added in version 3.22.

    The ISO 8601 week number of the current year (01-53).

%w  The day of the current week. 0 is Sunday. (0-6)

%a  Added in version 3.7.

    Abbreviated weekday name (e.g. Fri).

%A  Added in version 3.10.

    Full weekday name (e.g. Friday).

%y  The last two digits of the current year (00-99).

%Y  The current year.

%z  Added in version 3.26.

    The offset of the time zone from UTC, in hours and minutes, with format +hhmm or -hhmm.

%Z  Added in version 3.26.

    The time zone name.

    Unknown format specifiers will be ignored and copied to the output as-is.

    If no explicit <format_string> is given, it will default to:

•   %Y-%m-%dT%H:%M:%S for local time.

•   %Y-%m-%dT%H:%M:%SZ for UTC.

    Added in version 3.8: If the SOURCE_DATE_EPOCH environment variable is set, its value will be used instead of the current time. See https://reproducible-builds.org/specs/source-date-epoch/ for details.

string(UUID <output_variable> NAMESPACE <namespace> NAME <name> TYPE <MD5|SHA1> [UPPER])
    Added in version 3.1.

    Create a universally unique identifier (aka GUID) as per RFC4122 based on the hash of the combined values of <namespace> (which itself has to be a valid UUID) and <name>. The hash algorithm can be either MD5 (Version 3 UUID) or SHA1 (Version 5 UUID). A UUID has the format xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx where each x represents a lower case hexadecimal character. Where required, an uppercase representation can be requested with the optional UPPER flag.

  JSON

Added in version 3.19.

Functionality for querying a JSON string.

NOTE: In each of the following JSON-related subcommands, if the optional ERROR_VARIABLE argument is given, errors will be reported in <error-variable> and the <out-var> will be set to <member|index>-[<member|index>...]-NOTFOUND with the path elements up to the point where the error occurred, or just NOTFOUND if there is no relevant path. If an error occurs but the ERROR_VARIABLE option is not present, a fatal error message is generated. If no error occurs, the <error-variable> will be set to NOTFOUND.

In the following subcommands, the <json-string> argument should be written as a Quoted Argument to ensure the entire JSON string is passed as a single argument even if it contains semicolons.

string(JSON <out-var> [ERROR_VARIABLE <error-variable>] GET <json-string> <member|index> [<member|index> ...])
    Get an element from <json-string> at the location given by the list of <member|index> arguments. Array and object elements will be returned as a JSON string. Boolean elements will be returned as ON or OFF. Null elements will be returned as an empty string. Number and string types will be returned as strings.

string(JSON <out-var> [ERROR_VARIABLE <error-variable>] TYPE <json-string> <member|index> [<member|index> ...])
    Get the type of an element in <json-string> at the location given by the list of <member|index> arguments. The <out-var> will be set to one of NULL, NUMBER, STRING, BOOLEAN, ARRAY, or OBJECT.

string(JSON <out-var> [ERROR_VARIABLE <error-var>] MEMBER <json-string> [<member|index> ...] <index>)
    Get the name of the <index>-th member in <json-string> at the location given by the list of <member|index> arguments. Requires an element of object type.

string(JSON <out-var> [ERROR_VARIABLE <error-variable>] LENGTH <json-string> [<member|index> ...])
    Get the length of an element in <json-string> at the location given by the list of <member|index> arguments. Requires an element of array or object type.

string(JSON <out-var> [ERROR_VARIABLE <error-variable>] REMOVE <json-string> <member|index> [<member|index> ...])
    Remove an element from <json-string> at the location given by the list of <member|index> arguments. The JSON string without the removed element will be stored in <out-var>.

string(JSON <out-var> [ERROR_VARIABLE <error-variable>] SET <json-string> <member|index> [<member|index> ...] <value>)
    Set an element in <json-string> at the location given by the list of <member|index> arguments to <value>. The contents of <value> should be valid JSON. If <json-string> is an array, <value> can be appended to the end of the array by using a number greater or equal to the array length as the <member|index> argument.

string(JSON <out-var> [ERROR_VARIABLE <error-var>] EQUAL <json-string1> <json-string2>)
    Compare the two JSON objects given by <json-string1> and <json-string2> for equality. The contents of <json-string1> and <json-string2> should be valid JSON. The <out-var> will be set to a true value if the JSON objects are considered equal, or a false value otherwise.

  unset

Unset a variable, cache variable, or environment variable.

  Unset Normal Variable or Cache Entry

    unset(<variable> [CACHE | PARENT_SCOPE])

Removes a normal variable from the current scope, causing it to become undefined. If CACHE is present, then a cache variable is removed instead of a normal variable.

If PARENT_SCOPE is present then the variable is removed from the scope above the current scope. See the same option in the set() command for further details.

NOTE: When evaluating Variable References of the form ${VAR}, CMake first searches for a normal variable with that name. If no such normal variable exists, CMake will then search for a cache entry with that name. Because of this, unsetting a normal variable can expose a cache variable that was previously hidden. To force a variable reference of the form ${VAR} to return an empty string, use set(<variable> ""), which clears the normal variable but leaves it defined.

  Unset Environment Variable

    unset(ENV{<variable>})

Removes <variable> from the currently available Environment Variables. Subsequent calls of $ENV{<variable>} will return the empty string.

This command affects only the current CMake process, not the process from which CMake was called, nor the system environment at large, nor the environment of subsequent build or test processes.

  See Also

•   set()

  variable_watch

Watch the CMake variable for change.

    variable_watch(<variable> [<command>])

If the specified <variable> changes and no <command> is given, a message will be printed to inform about the change.

If <command> is given, this command will be executed instead. The command will receive the following arguments: COMMAND(<variable> <access> <value> <current_list_file> <stack>)

<variable>
    Name of the variable being accessed.

<access>
    One of READ_ACCESS, UNKNOWN_READ_ACCESS, MODIFIED_ACCESS, UNKNOWN_MODIFIED_ACCESS, or REMOVED_ACCESS. The UNKNOWN_ values are only used when the variable has never been set. Once set, they are never used again during the same CMake run, even if the variable is later unset.

<value>
    The value of the variable. On a modification, this is the new (modified) value of the variable. On removal, the value is empty.

<current_list_file>
    Full path to the file doing the access.

<stack>
    List of absolute paths of all files currently on the stack of file inclusion, with the bottom-most file first and the currently processed file (that is, current_list_file) last.

    Note that for some accesses such as list(APPEND), the watcher is executed twice, first with a read access and then with a write one. Also note that an if(DEFINED) query on the variable does not register as an access and the watcher is not executed.

    Only non-cache variables can be watched using this command. Access to cache variables is never watched. However, the existence of a cache variable var causes accesses to the non-cache variable var to not use the UNKNOWN_ prefix, even if a non-cache variable var has never existed.

  while

Evaluate a group of commands while a condition is true

    while(<condition>)
      <commands>
    endwhile()

All commands between while and the matching endwhile() are recorded without being invoked. Once the endwhile() is evaluated, the recorded list of commands is invoked as long as the <condition> is true.

The <condition> has the same syntax and is evaluated using the same logic as described at length for the if() command.

The commands break() and continue() provide means to escape from the normal control flow.

Per legacy, the endwhile() command admits an optional <condition> argument. If used, it must be a verbatim repeat of the argument of the opening while command.

  See Also

•   break()

•   continue()

•   foreach()

•   endwhile()

PROJECT COMMANDS

These commands are available only in CMake projects.

  add_compile_definitions

Added in version 3.12.

Add preprocessor definitions to the compilation of source files.

    add_compile_definitions(<definition> ...)

Adds preprocessor definitions to the compiler command line.

The preprocessor definitions are added to the COMPILE_DEFINITIONS directory property for the current CMakeLists file. They are also added to the COMPILE_DEFINITIONS target property for each target in the current CMakeLists file.

Definitions are specified using the syntax VAR or VAR=value. Function-style definitions are not supported. CMake will automatically escape the value correctly for the native build system (note that CMake language syntax may require escapes to specify some values).

Added in version 3.26: Any leading -D on an item will be removed.

Arguments to add_compile_definitions may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

  See Also

•   The command target_compile_definitions() adds target-specific definitions.

  add_compile_options

Add options to the compilation of source files.

    add_compile_options(<option> ...)

Adds options to the COMPILE_OPTIONS directory property. These options are used when compiling targets from the current directory and below.

NOTE: These options are not used when linking. See the add_link_options() command for that.

  Arguments

Arguments to add_compile_options may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

  Option De-duplication

The final set of options used for a target is constructed by accumulating options from the current target and the usage requirements of its dependencies. The set of options is de-duplicated to avoid repetition.

Added in version 3.12: While beneficial for individual options, the de-duplication step can break up option groups. For example, -option A -option B becomes -option A B. One may specify a group of options using shell-like quoting along with a SHELL: prefix. The SHELL: prefix is dropped, and the rest of the option string is parsed using the separate_arguments() UNIX_COMMAND mode. For example, "SHELL:-option A" "SHELL:-option B" becomes -option A -option B.

  Example

Since different compilers support different options, a typical use of this command is in a compiler-specific conditional clause:

    if (MSVC)
        # warning level 4
        add_compile_options(/W4)
    else()
        # additional warnings
        add_compile_options(-Wall -Wextra -Wpedantic)
    endif()

To set per-language options, use the $<COMPILE_LANGUAGE> or $<COMPILE_LANGUAGE:languages> generator expressions.

  See Also

•   This command can be used to add any options. However, for adding preprocessor definitions and include directories it is recommended to use the more specific commands add_compile_definitions() and include_directories().

•   The command target_compile_options() adds target-specific options.

•   This command adds compile options for all languages. Use the COMPILE_LANGUAGE generator expression to specify per-language compile options.

•   The source file property COMPILE_OPTIONS adds options to one source file.

•   add_link_options() adds options for linking.

•   CMAKE_<LANG>_FLAGS and CMAKE_<LANG>_FLAGS_<CONFIG> add language-wide flags passed to all invocations of the compiler. This includes invocations that drive compiling and those that drive linking.

  add_custom_command

Add a custom build rule to the generated build system.

There are two main signatures for add_custom_command.

  Generating Files

The first signature is for adding a custom command to produce an output:

    add_custom_command(OUTPUT output1 [output2 ...]
                       COMMAND command1 [ARGS] [args1...]
                       [COMMAND command2 [ARGS] [args2...] ...]
                       [MAIN_DEPENDENCY depend]
                       [DEPENDS [depends...]]
                       [BYPRODUCTS [files...]]
                       [IMPLICIT_DEPENDS <lang1> depend1
                                        [<lang2> depend2] ...]
                       [WORKING_DIRECTORY dir]
                       [COMMENT comment]
                       [DEPFILE depfile]
                       [JOB_POOL job_pool]
                       [JOB_SERVER_AWARE <bool>]
                       [VERBATIM] [APPEND] [USES_TERMINAL]
                       [CODEGEN]
                       [COMMAND_EXPAND_LISTS]
                       [DEPENDS_EXPLICIT_ONLY])

This defines a command to generate specified OUTPUT file(s). A target created in the same directory (CMakeLists.txt file) that specifies any output of the custom command as a source file is given a rule to generate the file using the command at build time.

Do not list the output in more than one independent target that may build in parallel or the instances of the rule may conflict. Instead, use the add_custom_target() command to drive the command and make the other targets depend on that one. See the Example: Generating Files for Multiple Targets below.

The options are:

APPEND
    Append the COMMAND and DEPENDS option values to the custom command for the first output specified. There must have already been a previous call to this command with the same output.

    If the previous call specified the output via a generator expression, the output specified by the current call must match in at least one configuration after evaluating generator expressions. In this case, the appended commands and dependencies apply to all configurations.

    The COMMENT, MAIN_DEPENDENCY, and WORKING_DIRECTORY options are currently ignored when APPEND is given, but may be used in the future.

BYPRODUCTS
    Added in version 3.2.

    Specify the files the command is expected to produce but whose modification time may or may not be newer than the dependencies. If a byproduct name is a relative path it will be interpreted relative to the build tree directory corresponding to the current source directory. Each byproduct file will be marked with the GENERATED source file property automatically.

    See policy CMP0058 for the motivation behind this feature.

    Explicit specification of byproducts is supported by the Ninja generator to tell the ninja build tool how to regenerate byproducts when they are missing. It is also useful when other build rules (e.g. custom commands) depend on the byproducts. Ninja requires a build rule for any generated file on which another rule depends even if there are order-only dependencies to ensure the byproducts will be available before their dependents build.

    The Makefile Generators will remove BYPRODUCTS and other GENERATED files during make clean.

    This keyword cannot be used with APPEND (see policy CMP0175). All byproducts must be set in the first call to add_custom_command(OUTPUT...) for the output files.

    Added in version 3.20: Arguments to BYPRODUCTS may use a restricted set of generator expressions. Target-dependent expressions are not permitted.

    Changed in version 3.28: In targets using File Sets, custom command byproducts are now considered private unless they are listed in a non-private file set. See policy CMP0154.

COMMAND
    Specify the command-line(s) to execute at build time. At least one COMMAND would normally be given, but certain patterns may omit it, such as adding commands in separate calls using APPEND.

    If more than one COMMAND is specified, they will be executed in order, but not necessarily composed into a stateful shell or batch script. To run a full script, use the configure_file() command or the file(GENERATE) command to create it, and then specify a COMMAND to launch it.

    The optional ARGS argument is for backward compatibility and will be ignored.

    If COMMAND specifies an executable target name (created by the add_executable() command), it will automatically be replaced by the location of the executable created at build time if either of the following is true:

•   The target is not being cross-compiled (i.e. the CMAKE_CROSSCOMPILING variable is not set to true).

•   Added in version 3.6: The target is being cross-compiled and an emulator is provided (i.e. its CROSSCOMPILING_EMULATOR target property is set). In this case, the contents of CROSSCOMPILING_EMULATOR will be prepended to the command before the location of the target executable.

    If neither of the above conditions are met, it is assumed that the command name is a program to be found on the PATH at build time.

    Arguments to COMMAND may use generator expressions. Use the TARGET_FILE generator expression to refer to the location of a target later in the command line (i.e. as a command argument rather than as the command to execute).

    Whenever one of the following target based generator expressions are used as a command to execute or is mentioned in a command argument, a target-level dependency will be added automatically so that the mentioned target will be built before any target using this custom command (see policy CMP0112).

•   TARGET_FILE

•   TARGET_LINKER_FILE

•   TARGET_SONAME_FILE

•   TARGET_PDB_FILE

    This target-level dependency does NOT add a file-level dependency that would cause the custom command to re-run whenever the executable is recompiled. List target names with the DEPENDS option to add such file-level dependencies.

COMMENT
    Display the given message before the commands are executed at build time. This will be ignored if APPEND is given, although a future version may use it.

    Added in version 3.26: Arguments to COMMENT may use generator expressions.

DEPENDS
    Specify files on which the command depends. Each argument is converted to a dependency as follows:

1.  If the argument is the name of a target (created by the add_custom_target(), add_executable(), or add_library() command) a target-level dependency is created to make sure the target is built before any target using this custom command. Additionally, if the target is an executable or library, a file-level dependency is created to cause the custom command to re-run whenever the target is recompiled.

2.  If the argument is an absolute path, a file-level dependency is created on that path.

3.  If the argument is the name of a source file that has been added to a target or on which a source file property has been set, a file-level dependency is created on that source file.

4.  If the argument is a relative path and it exists in the current source directory, a file-level dependency is created on that file in the current source directory.

5.  Otherwise, a file-level dependency is created on that path relative to the current binary directory.

    If any dependency is an OUTPUT of another custom command in the same directory (CMakeLists.txt file), CMake automatically brings the other custom command into the target in which this command is built.

    Added in version 3.16: A target-level dependency is added if any dependency is listed as BYPRODUCTS of a target or any of its build events in the same directory to ensure the byproducts will be available.

    If DEPENDS is not specified, the command will run whenever the OUTPUT is missing; if the command does not actually create the OUTPUT, the rule will always run.

    Added in version 3.1: Arguments to DEPENDS may use generator expressions.

COMMAND_EXPAND_LISTS
    Added in version 3.8.

    Lists in COMMAND arguments will be expanded, including those created with generator expressions, allowing COMMAND arguments such as ${CC} "-I$<JOIN:$<TARGET_PROPERTY:foo,INCLUDE_DIRECTORIES>,;-I>" foo.cc to be properly expanded.

    This keyword cannot be used with APPEND (see policy CMP0175). If the appended commands need this option to be set, it must be set on the first call to add_custom_command(OUTPUT...) for the output files.

CODEGEN
    Added in version 3.31.

    Adds the custom command to a global codegen target that can be used to execute the custom command while avoiding the majority of the build graph.

    This option is supported only by Ninja Generators and Makefile Generators, and is ignored by other generators. Furthermore, this option is allowed only if policy CMP0171 is set to NEW.

    This keyword cannot be used with APPEND (see policy CMP0175). It can only be set on the first call to add_custom_command(OUTPUT...) for the output files.

IMPLICIT_DEPENDS
    Request scanning of implicit dependencies of an input file. The language given specifies the programming language whose corresponding dependency scanner should be used. Currently only C and CXX language scanners are supported. The language has to be specified for every file in the IMPLICIT_DEPENDS list. Dependencies discovered from the scanning are added to those of the custom command at build time. Note that the IMPLICIT_DEPENDS option is currently supported only for Makefile generators and will be ignored by other generators.

    NOTE: This option cannot be specified at the same time as DEPFILE option.

JOB_POOL
    Added in version 3.15.

    Specify a pool for the Ninja generator. Incompatible with USES_TERMINAL, which implies the console pool. Using a pool that is not defined by JOB_POOLS causes an error by ninja at build time.

    This keyword cannot be used with APPEND (see policy CMP0175). Job pools can only be specified in the first call to add_custom_command(OUTPUT...) for the output files.

JOB_SERVER_AWARE
    Added in version 3.28.

    Specify that the command is GNU Make job server aware.

    For the Unix Makefiles, MSYS Makefiles, and MinGW Makefiles generators this will add the + prefix to the recipe line. See the GNU Make Documentation for more information.

    This option is silently ignored by other generators.

    This keyword cannot be used with APPEND (see policy CMP0175). Job server awareness can only be specified in the first call to add_custom_command(OUTPUT...) for the output files.

MAIN_DEPENDENCY
    Specify the primary input source file to the command. This is treated just like any value given to the DEPENDS option but also suggests to Visual Studio generators where to hang the custom command. Each source file may have at most one command specifying it as its main dependency. A compile command (i.e. for a library or an executable) counts as an implicit main dependency which gets silently overwritten by a custom command specification.

    This option is currently ignored if APPEND is given, but a future version may use it.

OUTPUT
    Specify the output files the command is expected to produce. Each output file will be marked with the GENERATED source file property automatically. If the output of the custom command is not actually created as a file on disk it should be marked with the SYMBOLIC source file property.

    If an output file name is a relative path, its absolute path is determined by interpreting it relative to:

1.  the build directory corresponding to the current source directory (CMAKE_CURRENT_BINARY_DIR), or

2.  the current source directory (CMAKE_CURRENT_SOURCE_DIR).

    The path in the build directory is preferred unless the path in the source tree is mentioned as an absolute source file path elsewhere in the current directory.

    The output file path may not contain < or > characters.

    Added in version 3.20: Arguments to OUTPUT may use a restricted set of generator expressions. Target-dependent expressions are not permitted.

    Changed in version 3.28: In targets using File Sets, custom command outputs are now considered private unless they are listed in a non-private file set. See policy CMP0154.

    Changed in version 3.30: The output file path may now use # characters, except when using the Borland Makefiles generator.

USES_TERMINAL
    Added in version 3.2.

    The command will be given direct access to the terminal if possible. With the Ninja generator, this places the command in the console pool.

    This keyword cannot be used with APPEND (see policy CMP0175). If the appended commands need access to the terminal, it must be set on the first call to add_custom_command(OUTPUT...) for the output files.

VERBATIM
    All arguments to the commands will be escaped properly for the build tool so that the invoked command receives each argument unchanged. Note that one level of escapes is still used by the CMake language processor before add_custom_command even sees the arguments. Use of VERBATIM is recommended as it enables correct behavior. When VERBATIM is not given the behavior is platform specific because there is no protection of tool-specific special characters.

    This keyword cannot be used with APPEND (see policy CMP0175). If the appended commands need to be treated as VERBATIM, it must be set on the first call to add_custom_command(OUTPUT...) for the output files.

WORKING_DIRECTORY
    Execute the command with the given current working directory. If it is a relative path, it will be interpreted relative to the build tree directory corresponding to the current source directory.

    This option is currently ignored if APPEND is given, but a future version may use it.

    Added in version 3.13: Arguments to WORKING_DIRECTORY may use generator expressions.

DEPFILE
    Added in version 3.7.

    Specify a depfile which holds dependencies for the custom command. It is usually emitted by the custom command itself. This keyword may only be used if the generator supports it, as detailed below.

    The expected format, compatible with what is generated by gcc with the option -M, is independent of the generator or platform.

    The formal syntax, as specified using BNF notation with the regular extensions, is the following:

    depfile       ::= rule*
    rule          ::= targets (':' (separator dependencies?)?)? eol
    targets       ::= target (separator target)* separator*
    target        ::= pathname
    dependencies  ::= dependency (separator dependency)* separator*
    dependency    ::= pathname
    separator     ::= (space | line_continue)+
    line_continue ::= '\' eol
    space         ::= ' ' | '\t'
    pathname      ::= character+
    character     ::= std_character | dollar | hash | whitespace
    std_character ::= <any character except '$', '#' or ' '>
    dollar        ::= '$$'
    hash          ::= '\#'
    whitespace    ::= '\ '
    eol           ::= '\r'? '\n'

    NOTE: As part of pathname, any slash and backslash is interpreted as a directory separator.

    Added in version 3.7: The Ninja generator supports DEPFILE since the keyword was first added.

    Added in version 3.17: Added the Ninja Multi-Config generator, which included support for the DEPFILE keyword.

    Added in version 3.20: Added support for Makefile Generators.

    NOTE: DEPFILE cannot be specified at the same time as the IMPLICIT_DEPENDS option for Makefile Generators.

    Added in version 3.21: Added support for Visual Studio Generators with VS 2012 and above, and for the Xcode generator. Support for generator expressions was also added.

    Added in version 3.29: The Ninja Generators will now incorporate the dependencies into its "deps log" database if the file is not listed in OUTPUTS or BYPRODUCTS.

    Using DEPFILE with generators other than those listed above is an error.

    If the DEPFILE argument is relative, it should be relative to CMAKE_CURRENT_BINARY_DIR, and any relative paths inside the DEPFILE should also be relative to CMAKE_CURRENT_BINARY_DIR. See policy CMP0116, which is always NEW for Makefile Generators, Visual Studio Generators, and the Xcode generator.

    This keyword cannot be used with APPEND (see policy CMP0175). Depfiles can only be set on the first call to add_custom_command(OUTPUT...) for the output files.

    DEPENDS_EXPLICIT_ONLY Added in version 3.27.

    Indicates that the command's DEPENDS argument represents all files required by the command and implicit dependencies are not required.

    Without this option, if any target uses the output of the custom command, CMake will consider that target's dependencies as implicit dependencies for the custom command in case this custom command requires files implicitly created by those targets.

    This option can be enabled on all custom commands by setting CMAKE_ADD_CUSTOM_COMMAND_DEPENDS_EXPLICIT_ONLY to ON.

    This keyword cannot be used with APPEND (see policy CMP0175). It can only be set on the first call to add_custom_command(OUTPUT...) for the output files.

    Only the Ninja Generators actually use this information to remove unnecessary implicit dependencies.

    See also the OPTIMIZE_DEPENDENCIES target property, which may provide another way for reducing the impact of target dependencies in some scenarios.

  Examples: Generating Files

Custom commands may be used to generate source files. For example, the code:

    add_custom_command(
      OUTPUT out.c
      COMMAND someTool -i ${CMAKE_CURRENT_SOURCE_DIR}/in.txt
                       -o out.c
      DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/in.txt
      VERBATIM)
    add_library(myLib out.c)

adds a custom command to run someTool to generate out.c and then compile the generated source as part of a library. The generation rule will re-run whenever in.txt changes.

Added in version 3.20: One may use generator expressions to specify per-configuration outputs. For example, the code:

    add_custom_command(
      OUTPUT "out-$<CONFIG>.c"
      COMMAND someTool -i ${CMAKE_CURRENT_SOURCE_DIR}/in.txt
                       -o "out-$<CONFIG>.c"
                       -c "$<CONFIG>"
      DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/in.txt
      VERBATIM)
    add_library(myLib "out-$<CONFIG>.c")

adds a custom command to run someTool to generate out-<config>.c, where <config> is the build configuration, and then compile the generated source as part of a library.

Added in version 3.31: Use the CODEGEN option to add a custom command's outputs to the builtin codegen target. This is useful to make generated code available for
 static analysis without building the entire project. For example:

    add_executable(someTool someTool.c)
    add_custom_command(
      OUTPUT out.c
      COMMAND someTool -o out.c
      CODEGEN)
    add_library(myLib out.c)

A user may build the codegen target to generate out.c. someTool is built as dependency, but myLib is not built at all.

  Example: Generating Files for Multiple Targets

If multiple independent targets need the same custom command output, it must be attached to a single custom target on which they all depend. Consider the following example:

    add_custom_command(
      OUTPUT table.csv
      COMMAND makeTable -i ${CMAKE_CURRENT_SOURCE_DIR}/input.dat
                        -o table.csv
      DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/input.dat
      VERBATIM)
    add_custom_target(generate_table_csv DEPENDS table.csv)
    add_custom_command(
      OUTPUT foo.cxx
      COMMAND genFromTable -i table.csv -case foo -o foo.cxx
      DEPENDS table.csv           # file-level dependency
              generate_table_csv  # target-level dependency
      VERBATIM)
    add_library(foo foo.cxx)
    add_custom_command(
      OUTPUT bar.cxx
      COMMAND genFromTable -i table.csv -case bar -o bar.cxx
      DEPENDS table.csv           # file-level dependency
              generate_table_csv  # target-level dependency
      VERBATIM)
    add_library(bar bar.cxx)

Output foo.cxx is needed only by target foo and output bar.cxx is needed only by target bar, but both targets need table.csv, transitively. Since foo and bar are independent targets that may build concurrently, we prevent them from racing to generate table.csv by placing its custom command in a separate target, generate_table_csv. The custom commands generating foo.cxx and bar.cxx each specify a target-level dependency on generate_table_csv, so the targets using them, foo and bar, will not build until after target generate_table_csv is built.

  Build Events

The second signature adds a custom command to a target such as a library or executable. This is useful for performing an operation before or after building the target. The command becomes part of the target and will only execute when the target itself is built. If the target is already built, the command will not execute.

    add_custom_command(TARGET <target>
                       PRE_BUILD | PRE_LINK | POST_BUILD
                       COMMAND command1 [ARGS] [args1...]
                       [COMMAND command2 [ARGS] [args2...] ...]
                       [BYPRODUCTS [files...]]
                       [WORKING_DIRECTORY dir]
                       [COMMENT comment]
                       [VERBATIM]
                       [COMMAND_EXPAND_LISTS]
                       [USES_TERMINAL])

This defines a new command that will be associated with building the specified <target>. The <target> must be defined in the current directory; targets defined in other directories may not be specified.

When the command will happen is determined by which of the following is specified:

PRE_BUILD
    This option has unique behavior for the Visual Studio Generators. When using one of the Visual Studio generators, the command will run before any other rules are executed within the target. With all other generators, this option behaves the same as PRE_LINK instead. Because of this, it is recommended to avoid using PRE_BUILD except when it is known that a Visual Studio generator is being used.

PRE_LINK
    Run after sources have been compiled but before linking the binary or running the librarian or archiver tool of a static library. This is not defined for targets created by the add_custom_target() command.

POST_BUILD
    Run after all other rules within the target have been executed.

    Projects should always specify one of the above three keywords when using the TARGET form. See policy CMP0175.

    All other keywords shown in the signature above have the same meaning as they do for the add_custom_command(OUTPUT) form of the command. At least one COMMAND must be given, see policy CMP0175.

    NOTE: Because generator expressions can be used in custom commands, it is possible to define COMMAND lines or whole custom commands which evaluate to empty strings for certain configurations. For Visual Studio Generators these command lines or custom commands will be omitted for the specific configuration and no "empty-string-command" will be added.

    This allows adding individual build events for every configuration.

    Added in version 3.21: Support for target-dependent generator expressions.

    Added in version 3.29: The <target> may be an ALIAS target.

  Examples: Build Events

A POST_BUILD event may be used to post-process a binary after linking. For example, the code:

    add_executable(myExe myExe.c)
    add_custom_command(
      TARGET myExe POST_BUILD
      COMMAND someHasher -i "$<TARGET_FILE:myExe>"
                         -o "$<TARGET_FILE:myExe>.hash"
      VERBATIM)

will run someHasher to produce a .hash file next to the executable after linking.

Added in version 3.20: One may use generator expressions to specify per-configuration byproducts. For example, the code:

    add_library(myPlugin MODULE myPlugin.c)
    add_custom_command(
      TARGET myPlugin POST_BUILD
      COMMAND someHasher -i "$<TARGET_FILE:myPlugin>"
                         --as-code "myPlugin-hash-$<CONFIG>.c"
      BYPRODUCTS "myPlugin-hash-$<CONFIG>.c"
      VERBATIM)
    add_executable(myExe myExe.c "myPlugin-hash-$<CONFIG>.c")

will run someHasher after linking myPlugin, e.g. to produce a .c file containing code to check the hash of myPlugin that the myExe executable can use to verify it before loading.

  Ninja Multi-Config

Added in version 3.20: add_custom_command supports the Ninja Multi-Config generator's cross-config capabilities. See the generator documentation for more information.

  See Also

•   add_custom_target()

  add_custom_target

Add a target with no output so it will always be built.

    add_custom_target(Name [ALL] [command1 [args1...]]
                      [COMMAND command2 [args2...] ...]
                      [DEPENDS depend depend depend ...]
                      [BYPRODUCTS [files...]]
                      [WORKING_DIRECTORY dir]
                      [COMMENT comment]
                      [JOB_POOL job_pool]
                      [JOB_SERVER_AWARE <bool>]
                      [VERBATIM] [USES_TERMINAL]
                      [COMMAND_EXPAND_LISTS]
                      [SOURCES src1 [src2...]])

Adds a target with the given name that executes the given commands. The target has no output file and is always considered out of date even if the commands try to create a file with the name of the target. Use the add_custom_command() command to generate a file with dependencies. By default nothing depends on the custom target. Use the add_dependencies() command to add dependencies to or from other targets.

The options are:

ALL Indicate that this target should be added to the default build target so that it will be run every time (the command cannot be called ALL).

BYPRODUCTS
    Added in version 3.2.

    Specify the files the command is expected to produce but whose modification time may or may not be updated on subsequent builds. If a byproduct name is a relative path it will be interpreted relative to the build tree directory corresponding to the current source directory. Each byproduct file will be marked with the GENERATED source file property automatically.

    See policy CMP0058 for the motivation behind this feature.

    Explicit specification of byproducts is supported by the Ninja generator to tell the ninja build tool how to regenerate byproducts when they are missing. It is also useful when other build rules (e.g. custom commands) depend on the byproducts. Ninja requires a build rule for any generated file on which another rule depends even if there are order-only dependencies to ensure the byproducts will be available before their dependents build.

    The Makefile Generators will remove BYPRODUCTS and other GENERATED files during make clean.

    Added in version 3.20: Arguments to BYPRODUCTS may use a restricted set of generator expressions. Target-dependent expressions are not permitted.

    Changed in version 3.28: In custom targets using File Sets, byproducts are now considered private unless they are listed in a non-private file set. See policy CMP0154.

COMMAND
    Specify the command-line(s) to execute at build time. If more than one COMMAND is specified they will be executed in order, but not necessarily composed into a stateful shell or batch script. (To run a full script, use the configure_file() command or the file(GENERATE) command to create it, and then specify a COMMAND to launch it.)

    If COMMAND specifies an executable target name (created by the add_executable() command), it will automatically be replaced by the location of the executable created at build time if either of the following is true:

•   The target is not being cross-compiled (i.e. the CMAKE_CROSSCOMPILING variable is not set to true).

•   Added in version 3.6: The target is being cross-compiled and an emulator is provided (i.e. its CROSSCOMPILING_EMULATOR target property is set). In this case, the contents of CROSSCOMPILING_EMULATOR will be prepended to the command before the location of the target executable.

    If neither of the above conditions are met, it is assumed that the command name is a program to be found on the PATH at build time.

    Arguments to COMMAND may use generator expressions. Use the TARGET_FILE generator expression to refer to the location of a target later in the command line (i.e. as a command argument rather than as the command to execute).

    Whenever one of the following target based generator expressions are used as a command to execute or is mentioned in a command argument, a target-level dependency will be added automatically so that the mentioned target will be built before this custom target (see policy CMP0112).

•   TARGET_FILE

•   TARGET_LINKER_FILE

•   TARGET_SONAME_FILE

•   TARGET_PDB_FILE

    The command and arguments are optional and if not specified an empty target will be created.

COMMENT
    Display the given message before the commands are executed at build time.

    Added in version 3.26: Arguments to COMMENT may use generator expressions.

DEPENDS
    Reference files and outputs of custom commands created with add_custom_command() command calls in the same directory (CMakeLists.txt file). They will be brought up to date when the target is built.

    Changed in version 3.16: A target-level dependency is added if any dependency is a byproduct of a target or any of its build events in the same directory to ensure the byproducts will be available before this target is built.

    Use the add_dependencies() command to add dependencies on other targets.

COMMAND_EXPAND_LISTS
    Added in version 3.8.

    Lists in COMMAND arguments will be expanded, including those created with generator expressions, allowing COMMAND arguments such as ${CC} "-I$<JOIN:$<TARGET_PROPERTY:foo,INCLUDE_DIRECTORIES>,;-I>" foo.cc to be properly expanded.

JOB_POOL
    Added in version 3.15.

    Specify a pool for the Ninja generator. Incompatible with USES_TERMINAL, which implies the console pool. Using a pool that is not defined by JOB_POOLS causes an error by ninja at build time.

JOB_SERVER_AWARE
    Added in version 3.28.

    Specify that the command is GNU Make job server aware.

    For the Unix Makefiles, MSYS Makefiles, and MinGW Makefiles generators this will add the + prefix to the recipe line. See the GNU Make Documentation for more information.

    This option is silently ignored by other generators.

SOURCES
    Specify additional source files to be included in the custom target. Specified source files will be added to IDE project files for convenience in editing even if they have no build rules.

VERBATIM
    All arguments to the commands will be escaped properly for the build tool so that the invoked command receives each argument unchanged. Note that one level of escapes is still used by the CMake language processor before add_custom_target even sees the arguments. Use of VERBATIM is recommended as it enables correct behavior. When VERBATIM is not given the behavior is platform specific because there is no protection of tool-specific special characters.

USES_TERMINAL
    Added in version 3.2.

    The command will be given direct access to the terminal if possible. With the Ninja generator, this places the command in the console pool.

WORKING_DIRECTORY
    Execute the command with the given current working directory. If it is a relative path it will be interpreted relative to the build tree directory corresponding to the current source directory.

    Added in version 3.13: Arguments to WORKING_DIRECTORY may use generator expressions.

  Ninja Multi-Config

Added in version 3.20: add_custom_target supports the Ninja Multi-Config generator's cross-config capabilities. See the generator documentation for more information.

  See Also

•   add_custom_command()

  add_definitions

Add -D define flags to the compilation of source files.

    add_definitions(-DFOO -DBAR ...)

Adds definitions to the compiler command line for targets in the current directory, whether added before or after this command is invoked, and for the ones in sub-directories added after. This command can be used to add any flags, but it is intended to add preprocessor definitions.

NOTE: This command has been superseded by alternatives:

•   Use add_compile_definitions() to add preprocessor definitions.

•   Use include_directories() to add include directories.

•   Use add_compile_options() to add other options.

    Flags beginning in -D or /D that look like preprocessor definitions are automatically added to the COMPILE_DEFINITIONS directory property for the current directory. Definitions with non-trivial values may be left in the set of flags instead of being converted for reasons of backwards compatibility. See documentation of the directory, target, source file COMPILE_DEFINITIONS properties for details on adding preprocessor definitions to specific scopes and configurations.

  See Also

•   The cmake-buildsystem(7) manual for more on defining buildsystem properties.

  add_dependencies

Add a dependency between top-level targets.

    add_dependencies(<target> <target-dependency>...)

Makes a top-level <target> depend on other top-level targets to ensure that they build before <target> does. A top-level target is one created by one of the add_executable(), add_library(), or add_custom_target() commands (but not targets generated by CMake like install). At least one <target-dependency> must be given.

Dependencies added to an imported target or an interface library are followed transitively in its place since the target itself does not build.

Added in version 3.3: Allow adding dependencies to interface libraries.

Added in version 3.8: Dependencies will populate the MANUALLY_ADDED_DEPENDENCIES property of <target>.

Changed in version 3.9: The Ninja Generators use weaker ordering than other generators in order to improve available concurrency. They only guarantee that the dependencies' custom commands are finished before sources in <target> start compiling; this ensures generated sources are available.

  See Also

•   The DEPENDS option of add_custom_target() and add_custom_command() commands for adding file-level dependencies in custom rules.

•   The OBJECT_DEPENDS source file property to add file-level dependencies to object files.

  add_executable

Add an executable to the project using the specified source files.

  Normal Executables

add_executable(<name> <options>... <sources>...)
    Add an executable target called <name> to be built from the source files listed in the command invocation.

    The options are:

WIN32
    Set the WIN32_EXECUTABLE target property automatically. See documentation of that target property for details.

MACOSX_BUNDLE
    Set the MACOSX_BUNDLE target property automatically. See documentation of that target property for details.

EXCLUDE_FROM_ALL
    Set the EXCLUDE_FROM_ALL target property automatically. See documentation of that target property for details.

    The <name> corresponds to the logical target name and must be globally unique within a project. The actual file name of the executable built is constructed based on conventions of the native platform (such as <name>.exe or just <name>).

    Added in version 3.1: Source arguments to add_executable may use "generator expressions" with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions.

    Added in version 3.11: The source files can be omitted if they are added later using target_sources().

    By default the executable file will be created in the build tree directory corresponding to the source tree directory in which the command was invoked. See documentation of the RUNTIME_OUTPUT_DIRECTORY target property to change this location. See documentation of the OUTPUT_NAME target property to change the <name> part of the final file name.

    See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

    See also HEADER_FILE_ONLY on what to do if some sources are pre-processed, and you want to have the original sources reachable from within IDE.

  Imported Executables

add_executable(<name> IMPORTED [GLOBAL])
    Add an IMPORTED executable target to reference an executable file located outside the project. The target name may be referenced like any target built within the project, except that by default it is visible only in the directory in which it is created, and below.

    The options are:

GLOBAL
    Make the target name globally visible.

    No rules are generated to build imported targets, and the IMPORTED target property is True. Imported executables are useful for convenient reference from commands like add_custom_command().

    Details about the imported executable are specified by setting properties whose names begin in IMPORTED_. The most important such property is IMPORTED_LOCATION (and its per-configuration version IMPORTED_LOCATION_<CONFIG>) which specifies the location of the main executable file on disk. See documentation of the IMPORTED_* properties for more information.

  Alias Executables

add_executable(<name> ALIAS <target>)
    Creates an Alias Target, such that <name> can be used to refer to <target> in subsequent commands. The <name> does not appear in the generated buildsystem as a make target. The <target> may not be an ALIAS.

    Added in version 3.11: An ALIAS can target a GLOBAL Imported Target

    Added in version 3.18: An ALIAS can target a non-GLOBAL Imported Target. Such alias is scoped to the directory in which it is created and subdirectories. The ALIAS_GLOBAL target property can be used to check if the alias is global or not.

    ALIAS targets can be used as targets to read properties from, executables for custom commands and custom targets. They can also be tested for existence with the regular if(TARGET) subcommand. The <name> may not be used to modify properties of <target>, that is, it may not be used as the operand of set_property(), set_target_properties(), target_link_libraries() etc. An ALIAS target may not be installed or exported.

  See Also

•   add_library()

  add_library

Add a library to the project using the specified source files.

  Normal Libraries

add_library(<name> [<type>] [EXCLUDE_FROM_ALL] <sources>...)
    Add a library target called <name> to be built from the source files listed in the command invocation.

    The optional <type> specifies the type of library to be created:

STATIC
    A Static Library: an archive of object files for use when linking other targets.

SHARED
    A Shared Library: a dynamic library that may be linked by other targets and loaded at runtime.

MODULE
    A Module Library: a plugin that may not be linked by other targets, but may be dynamically loaded at runtime using dlopen-like functionality.

    If no <type> is given the default is STATIC or SHARED based on the value of the BUILD_SHARED_LIBS variable.

    The options are:

EXCLUDE_FROM_ALL
    Set the EXCLUDE_FROM_ALL target property automatically. See documentation of that target property for details.

    The <name> corresponds to the logical target name and must be globally unique within a project. The actual file name of the library built is constructed based on conventions of the native platform (such as lib<name>.a or <name>.lib).

    Added in version 3.1: Source arguments to add_library may use "generator expressions" with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions.

    Added in version 3.11: The source files can be omitted if they are added later using target_sources().

    For SHARED and MODULE libraries the POSITION_INDEPENDENT_CODE target property is set to ON automatically. A SHARED library may be marked with the FRAMEWORK target property to create an macOS Framework.

    Added in version 3.8: A STATIC library may be marked with the FRAMEWORK target property to create a static Framework.

    If a library does not export any symbols, it must not be declared as a SHARED library. For example, a Windows resource DLL or a managed C++/CLI DLL that exports no unmanaged symbols would need to be a MODULE library. This is because CMake expects a SHARED library to always have an associated import library on Windows.

    By default the library file will be created in the build tree directory corresponding to the source tree directory in which the command was invoked. See documentation of the ARCHIVE_OUTPUT_DIRECTORY, LIBRARY_OUTPUT_DIRECTORY, and RUNTIME_OUTPUT_DIRECTORY target properties to change this location. See documentation of the OUTPUT_NAME target property to change the <name> part of the final file name.

    See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

    See also HEADER_FILE_ONLY on what to do if some sources are pre-processed, and you want to have the original sources reachable from within IDE.

    Changed in version 3.30: On platforms that do not support shared libraries, add_library now fails on calls creating SHARED libraries instead of automatically converting them to STATIC libraries as before. See policy CMP0164.

  Object Libraries

add_library(<name> OBJECT <sources>...)
    Add an Object Library to compile source files without archiving or linking their object files into a library.

    Other targets created by add_library or add_executable() may reference the objects using an expression of the form $<TARGET_OBJECTS:objlib> as a source, where objlib is the object library name. For example:

        add_library(... $<TARGET_OBJECTS:objlib> ...)
        add_executable(... $<TARGET_OBJECTS:objlib> ...)

    will include objlib's object files in a library and an executable along with those compiled from their own sources. Object libraries may contain only sources that compile, header files, and other files that would not affect linking of a normal library (e.g. .txt). They may contain custom commands generating such sources, but not PRE_BUILD, PRE_LINK, or POST_BUILD commands. Some native build systems (such as Xcode) may not like targets that have only object files, so consider adding at least one real source file to any target that references $<TARGET_OBJECTS:objlib>.

    Added in version 3.12: Object libraries can be linked to with target_link_libraries().

  Interface Libraries

add_library(<name> INTERFACE)
    Add an Interface Library target that may specify usage requirements for dependents but does not compile sources and does not produce a library artifact on disk.

    An interface library with no source files is not included as a target in the generated buildsystem. However, it may have properties set on it and it may be installed and exported. Typically, INTERFACE_* properties are populated on an interface target using the commands:

•   set_property(),

•   target_link_libraries(INTERFACE),

•   target_link_options(INTERFACE),

•   target_include_directories(INTERFACE),

•   target_compile_options(INTERFACE),

•   target_compile_definitions(INTERFACE), and

•   target_sources(INTERFACE),

    and then it is used as an argument to target_link_libraries() like any other target.

    Added in version 3.15: An interface library can have PUBLIC_HEADER and PRIVATE_HEADER properties. The headers specified by those properties can be installed using the install(TARGETS) command.

add_library(<name> INTERFACE [EXCLUDE_FROM_ALL] <sources>...)
    Added in version 3.19.

    Add an Interface Library target with source files (in addition to usage requirements and properties as documented by the above signature). Source files may be listed directly in the add_library call or added later by calls to target_sources() with the PRIVATE or PUBLIC keywords.

    If an interface library has source files (i.e. the SOURCES target property is set), or header sets (i.e. the HEADER_SETS target property is set), it will appear in the generated buildsystem as a build target much like a target defined by the add_custom_target() command. It does not compile any sources, but does contain build rules for custom commands created by the add_custom_command() command.

    The options are:

EXCLUDE_FROM_ALL
    Set the EXCLUDE_FROM_ALL target property automatically. See documentation of that target property for details.

    NOTE: In most command signatures where the INTERFACE keyword appears, the items listed after it only become part of that target's usage requirements and are not part of the target's own settings. However, in this signature of add_library, the INTERFACE keyword refers to the library type only. Sources listed after it in the add_library call are PRIVATE to the interface library and do not appear in its INTERFACE_SOURCES target property.

  Imported Libraries

add_library(<name> <type> IMPORTED [GLOBAL])
    Add an IMPORTED library target called <name>. The target name may be referenced like any target built within the project, except that by default it is visible only in the directory in which it is created, and below.

    The <type> must be one of:

STATIC, SHARED, MODULE, UNKNOWN
    References a library file located outside the project. The IMPORTED_LOCATION target property (or its per-configuration variant IMPORTED_LOCATION_<CONFIG>) specifies the location of the main library file on disk:

•   For a SHARED library on most non-Windows platforms, the main library file is the .so or .dylib file used by both linkers and dynamic loaders. If the referenced library file has a SONAME (or on macOS, has a LC_ID_DYLIB starting in @rpath/), the value of that field should be set in the IMPORTED_SONAME target property. If the referenced library file does not have a SONAME, but the platform supports it, then the IMPORTED_NO_SONAME target property should be set.

•   For a SHARED library on Windows, the IMPORTED_IMPLIB target property (or its per-configuration variant IMPORTED_IMPLIB_<CONFIG>) specifies the location of the DLL import library file (.lib or .dll.a) on disk, and the IMPORTED_LOCATION is the location of the .dll runtime library (and is optional, but needed by the TARGET_RUNTIME_DLLS generator expression).

    Additional usage requirements may be specified in INTERFACE_* properties.

    An UNKNOWN library type is typically only used in the implementation of Find Modules. It allows the path to an imported library (often found using the find_library() command) to be used without having to know what type of library it is. This is especially useful on Windows where a static library and a DLL's import library both have the same file extension.

OBJECT
    References a set of object files located outside the project. The IMPORTED_OBJECTS target property (or its per-configuration variant IMPORTED_OBJECTS_<CONFIG>) specifies the locations of object files on disk. Additional usage requirements may be specified in INTERFACE_* properties.

INTERFACE
    Does not reference any library or object files on disk, but may specify usage requirements in INTERFACE_* properties.

    The options are:

GLOBAL
    Make the target name globally visible.

    No rules are generated to build imported targets, and the IMPORTED target property is True. Imported libraries are useful for convenient reference from commands like target_link_libraries().

    Details about the imported library are specified by setting properties whose names begin in IMPORTED_ and INTERFACE_. See documentation of such properties for more information.

  Alias Libraries

add_library(<name> ALIAS <target>)
    Creates an Alias Target, such that <name> can be used to refer to <target> in subsequent commands. The <name> does not appear in the generated buildsystem as a make target. The <target> may not be an ALIAS.

    Added in version 3.11: An ALIAS can target a GLOBAL Imported Target

    Added in version 3.18: An ALIAS can target a non-GLOBAL Imported Target. Such alias is scoped to the directory in which it is created and below. The ALIAS_GLOBAL target property can be used to check if the alias is global or not.

    ALIAS targets can be used as linkable targets and as targets to read properties from. They can also be tested for existence with the regular if(TARGET) subcommand. The <name> may not be used to modify properties of <target>, that is, it may not be used as the operand of set_property(), set_target_properties(), target_link_libraries() etc. An ALIAS target may not be installed or exported.

  See Also

•   add_executable()

  add_link_options

Added in version 3.13.

Add options to the link step for executable, shared library or module library targets in the current directory and below that are added after this command is invoked.

    add_link_options(<option> ...)

This command can be used to add any link options, but alternative commands exist to add libraries (target_link_libraries() or link_libraries()). See documentation of the directory and target LINK_OPTIONS properties.

NOTE: This command cannot be used to add options for static library targets, since they do not use a linker. To add archiver or MSVC librarian flags, see the STATIC_LIBRARY_OPTIONS target property.

Arguments to add_link_options may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

  Host And Device Specific Link Options

Added in version 3.18: When a device link step is involved, which is controlled by CUDA_SEPARABLE_COMPILATION and CUDA_RESOLVE_DEVICE_SYMBOLS properties and policy CMP0105, the raw options will be delivered to the host and device link steps (wrapped in -Xcompiler or equivalent for device link). Options wrapped with $<DEVICE_LINK:...> generator expression will be used only for the device link step. Options wrapped with $<HOST_LINK:...> generator expression will be used only for the host link step.

  Option De-duplication

The final set of options used for a target is constructed by accumulating options from the current target and the usage requirements of its dependencies. The set of options is de-duplicated to avoid repetition.

Added in version 3.12: While beneficial for individual options, the de-duplication step can break up option groups. For example, -option A -option B becomes -option A B. One may specify a group of options using shell-like quoting along with a SHELL: prefix. The SHELL: prefix is dropped, and the rest of the option string is parsed using the separate_arguments() UNIX_COMMAND mode. For example, "SHELL:-option A" "SHELL:-option B" becomes -option A -option B.

  Handling Compiler Driver Differences

To pass options to the linker tool, each compiler driver has its own syntax. The LINKER: prefix and , separator can be used to specify, in a portable way, options to pass to the linker tool. LINKER: is replaced by the appropriate driver option and , by the appropriate driver separator. The driver prefix and driver separator are given by the values of the CMAKE_<LANG>_LINKER_WRAPPER_FLAG and CMAKE_<LANG>_LINKER_WRAPPER_FLAG_SEP variables.

For example, "LINKER:-z,defs" becomes -Xlinker -z -Xlinker defs for Clang and -Wl,-z,defs for GNU GCC.

The LINKER: prefix can be specified as part of a SHELL: prefix expression.

The LINKER: prefix supports, as an alternative syntax, specification of arguments using the SHELL: prefix and space as separator. The previous example then becomes "LINKER:SHELL:-z defs".

NOTE: Specifying the SHELL: prefix anywhere other than at the beginning of the LINKER: prefix is not supported.

  See Also

•   link_libraries()

•   target_link_libraries()

•   target_link_options()

•   CMAKE_<LANG>_FLAGS and CMAKE_<LANG>_FLAGS_<CONFIG> add language-wide flags passed to all invocations of the compiler. This includes invocations that drive compiling and those that drive linking.

  add_subdirectory

Add a subdirectory to the build.

    add_subdirectory(source_dir [binary_dir] [EXCLUDE_FROM_ALL] [SYSTEM])

Adds a subdirectory to the build. The source_dir specifies the directory in which the source CMakeLists.txt and code files are located. If it is a relative path, it will be evaluated with respect to the current directory (the typical usage), but it may also be an absolute path. The binary_dir specifies the directory in which to place the output files. If it is a relative path, it will be evaluated with respect to the current output directory, but it may also be an absolute path. If binary_dir is not specified, the value of source_dir, before expanding any relative path, will be used (the typical usage). The CMakeLists.txt file in the specified source directory will be processed immediately by CMake before processing in the current input file continues beyond this command.

If the EXCLUDE_FROM_ALL argument is provided then the EXCLUDE_FROM_ALL property will be set on the added directory. This will exclude the directory from a default build. See the directory property EXCLUDE_FROM_ALL for full details.

Added in version 3.25: If the SYSTEM argument is provided, the SYSTEM directory property of the subdirectory will be set to true. This property is used to initialize the SYSTEM property of each non-imported target created in that subdirectory.

  add_test

Add a test to the project to be run by ctest(1).

    add_test(NAME <name> COMMAND <command> [<arg>...]
             [CONFIGURATIONS <config>...]
             [WORKING_DIRECTORY <dir>]
             [COMMAND_EXPAND_LISTS])

Adds a test called <name>. The test name may contain arbitrary characters, expressed as a Quoted Argument or Bracket Argument if necessary. See policy CMP0110.

CMake only generates tests if the enable_testing() command has been invoked. The CTest module invokes enable_testing automatically unless BUILD_TESTING is set to OFF.

Tests added with the add_test(NAME) signature support using generator expressions in test properties set by set_property(TEST) or set_tests_properties(). Test properties may only be set in the directory the test is created in.

add_test options are:

COMMAND
    Specify the test command-line.

    If <command> specifies an executable target created by add_executable():

•   It will automatically be replaced by the location of the executable created at build time.

•   Added in version 3.3: The target's CROSSCOMPILING_EMULATOR, if set, will be used to run the command on the host:

        <emulator> <command>

    Changed in version 3.29: The emulator is used only when cross-compiling. See policy CMP0158.

•   Added in version 3.29: The target's TEST_LAUNCHER, if set, will be used to launch the command:

        <launcher> <command>

    If the CROSSCOMPILING_EMULATOR is also set, both are used:

        <launcher> <emulator> <command>

    The command may be specified using generator expressions.

CONFIGURATIONS
    Restrict execution of the test only to the named configurations.

WORKING_DIRECTORY
    Set the test property WORKING_DIRECTORY in which to execute the test. If not specified, the test will be run in CMAKE_CURRENT_BINARY_DIR. The working directory may be specified using generator expressions.

COMMAND_EXPAND_LISTS
    Added in version 3.16.

    Lists in COMMAND arguments will be expanded, including those created with generator expressions.

    If the test command exits with code 0 the test passes. Non-zero exit code is a "failed" test. The test property WILL_FAIL inverts this logic. Note that system-level test failures such as segmentation faults or heap errors will still fail the test even if WILL_FAIL is true. Output written to stdout or stderr is captured by ctest(1) and only affects the pass/fail status via the PASS_REGULAR_EXPRESSION, FAIL_REGULAR_EXPRESSION, or SKIP_REGULAR_EXPRESSION test properties.

    Added in version 3.16: Added SKIP_REGULAR_EXPRESSION property.

    Example usage:

        add_test(NAME mytest
                 COMMAND testDriver --config $<CONFIG>
                                    --exe $<TARGET_FILE:myexe>)

    This creates a test mytest whose command runs a testDriver tool passing the configuration name and the full path to the executable file produced by target myexe.

    ----

    The command syntax above is recommended over the older, less flexible form:

        add_test(<name> <command> [<arg>...])

    Add a test called <name> with the given command-line.

    Unlike the above NAME signature, target names are not supported in the command-line. Furthermore, tests added with this signature do not support generator expressions in the command-line or test properties.

  aux_source_directory

Find all source files in a directory.

    aux_source_directory(<dir> <variable>)

Collects the names of all the source files in the specified directory and stores the list in the <variable> provided. This command is intended to be used by projects that use explicit template instantiation. Template instantiation files can be stored in a Templates subdirectory and collected automatically using this command to avoid manually listing all instantiations.

It is tempting to use this command to avoid writing the list of source files for a library or executable target. While this seems to work, there is no way for CMake to generate a build system that knows when a new source file has been added. Normally the generated build system knows when it needs to rerun CMake because the CMakeLists.txt file is modified to add a new source. When the source is just added to the directory without modifying this file, one would have to manually rerun CMake to generate a build system incorporating the new file.

  build_command

Get a command line to build the current project. This is mainly intended for internal use by the CTest module.

    build_command(<variable>
                  [CONFIGURATION <config>]
                  [PARALLEL_LEVEL <parallel>]
                  [TARGET <target>]
                  [PROJECT_NAME <projname>] # legacy, causes warning
                 )

Sets the given <variable> to a command-line string of the form:

    <cmake> --build . [--config <config>] [--parallel <parallel>] [--target <target>...]

where <cmake> is the location of the cmake(1) command-line tool, and <config>, <parallel> and <target> are the values provided to the CONFIGURATION, PARALLEL_LEVEL and TARGET options, if any. In CMake versions prior to 4.0, a trailing -- -i option was added for Makefile Generators if policy CMP0061 was not set to NEW.

When invoked, this cmake --build command line will launch the underlying build system tool.

Added in version 3.21: The PARALLEL_LEVEL argument can be used to set the --parallel flag.

    build_command(<cachevariable> <makecommand>)

This second signature is deprecated, but still available for backwards compatibility. Use the first signature instead.

It sets the given <cachevariable> to a command-line string as above but without the --target option. The <makecommand> is ignored but should be the full path to devenv, nmake, make or one of the end user build tools for legacy invocations.

NOTE: In CMake versions prior to 3.0 this command returned a command line that directly invokes the native build tool for the current generator. Their implementation of the PROJECT_NAME option had no useful effects, so CMake now warns on use of the option.

  cmake_file_api

Added in version 3.27.

Enables interacting with the CMake file API.

cmake_file_api(QUERY ...)
    The QUERY subcommand adds a file API query for the current CMake invocation.

        cmake_file_api(
          QUERY
          API_VERSION <version>
          [CODEMODEL <versions>...]
          [CACHE <versions>...]
          [CMAKEFILES <versions>...]
          [TOOLCHAINS <versions>...]
        )

    The API_VERSION must always be given. Currently, the only supported value for <version> is 1. See API v1 for details of the reply content and location.

    Each of the optional keywords CODEMODEL, CACHE, CMAKEFILES and TOOLCHAINS correspond to one of the object kinds that can be requested by the project. The configureLog object kind cannot be set with this command, since it must be set before CMake starts reading the top level CMakeLists.txt file.

    For each of the optional keywords, the <versions> list must contain one or more version values of the form major or major.minor, where major and minor are integers. Projects should list the versions they accept in their preferred order, as only the first supported value from the list will be selected. The command will ignore versions with a major version higher than any major version it supports for that object kind. It will raise an error if it encounters an invalid version number, or if none of the requested versions is supported.

    For each type of object kind requested, a query equivalent to a shared, stateless query will be added internally. No query file will be created in the file system. The reply will be written to the file system at generation time.

    It is not an error to add a query for the same thing more than once, whether from query files or from multiple calls to cmake_file_api(QUERY). The final set of queries will be a merged combination of all queries specified on disk and queries submitted by the project.

  Example

A project may want to use replies from the file API at build time to implement some form of verification task. Instead of relying on something outside of CMake to create a query file, the project can use cmake_file_api(QUERY) to request the required information for the current run. It can then create a custom command to run at build time, knowing that the requested information should always be available.

    cmake_file_api(
      QUERY
      API_VERSION 1
      CODEMODEL 2.3
      TOOLCHAINS 1
    )
    add_custom_target(verify_project
      COMMAND ${CMAKE_COMMAND}
        -D BUILD_DIR=${CMAKE_BINARY_DIR}
        -D CONFIG=$<CONFIG>
        -P ${CMAKE_CURRENT_SOURCE_DIR}/verify_project.cmake
    )

  cmake_instrumentation

Added in version 4.0.

NOTE: This command is only available when experimental support for instrumentation has been enabled by the CMAKE_EXPERIMENTAL_INSTRUMENTATION gate.

Enables interacting with the CMake Instrumentation API.

This allows for configuring instrumentation at the project-level.

    cmake_instrumentation(
      API_VERSION <version>
      DATA_VERSION <version>
      [HOOKS <hooks>...]
      [QUERIES <queries>...]
      [CALLBACK <callback>]
    )

The API_VERSION and DATA_VERSION must always be given. Currently, the only supported value for both fields is 1. See API v1 for details of the API_VERSION and Data v1 for details of the DATA_VERSION.

Each of the optional keywords HOOKS, QUERIES, and CALLBACK correspond to one of the parameters to the v1 Query Files. The CALLBACK keyword can be provided multiple times to create multiple callbacks.

Whenever cmake_instrumentation is invoked, a query file is generated in <build>/.cmake/instrumentation/v1/query/generated to enable instrumentation with the provided arguments.

  Example

The following example shows an invocation of the command and its equivalent JSON query file.

    cmake_instrumentation(
      API_VERSION 1
      DATA_VERSION 1
      HOOKS postGenerate preCMakeBuild postCMakeBuild
      QUERIES staticSystemInformation dynamicSystemInformation
      CALLBACK ${CMAKE_COMMAND} -P /path/to/handle_data.cmake
      CALLBACK ${CMAKE_COMMAND} -P /path/to/handle_data_2.cmake
    )

    {
      "version": 1,
      "hooks": [
        "postGenerate", "preCMakeBuild", "postCMakeBuild"
      ],
      "queries": [
        "staticSystemInformation", "dynamicSystemInformation"
      ],
      "callbacks": [
        "/path/to/cmake -P /path/to/handle_data.cmake"
        "/path/to/cmake -P /path/to/handle_data_2.cmake"
      ]
    }

  create_test_sourcelist

Create a test driver program that links together many small tests into a single executable. This is useful when building static executables with large libraries to shrink the total required size.

create_test_sourcelist(<sourceListName> <driverName> <test>... <options>...)
    Generate a test driver source file from a list of individual test sources and provide a combined list of sources that can be built as an executable.

    The options are:

<sourceListName>
    The name of a variable in which to store the list of source files needed to build the test driver. The list will contain the <test>... sources and the generated <driverName> source.

    Changed in version 3.29: The test driver source is listed by absolute path in the build tree. Previously it was listed only as <driverName>.

<driverName>
    Name of the test driver source file to be generated into the build tree. The source file will contain a main() program entry point that dispatches to whatever test is named on the command line.

<test>...
    Test source files to be added to the driver binary. Each test source file must have a function in it that is the same name as the file with the extension removed. For example, a foo.cxx test source might contain:

        int foo(int argc, char** argv)

EXTRA_INCLUDE <header>
    Specify a header file to #include in the generated test driver source.

FUNCTION <function>
    Specify a function to be called with pointers to argc and argv. The function may be provided in the EXTRA_INCLUDE header:

        void function(int* pargc, char*** pargv)

    This can be used to add extra command line processing to each test.

    Additionally, some CMake variables affect test driver generation:

CMAKE_TESTDRIVER_BEFORE_TESTMAIN
    Code to be placed directly before calling each test's function.

CMAKE_TESTDRIVER_AFTER_TESTMAIN
    Code to be placed directly after the call to each test's function.

  define_property

Define and document custom properties.

    define_property(<GLOBAL | DIRECTORY | TARGET | SOURCE |
                     TEST | VARIABLE | CACHED_VARIABLE>
                     PROPERTY <name> [INHERITED]
                     [BRIEF_DOCS <brief-doc> [docs...]]
                     [FULL_DOCS <full-doc> [docs...]]
                     [INITIALIZE_FROM_VARIABLE <variable>])

Defines one property in a scope for use with the set_property() and get_property() commands. It is mainly useful for defining the way a property is initialized or inherited. Historically, the command also associated documentation with a property, but that is no longer considered a primary use case.

The first argument determines the kind of scope in which the property should be used. It must be one of the following:

•   GLOBAL - associated with the global namespace.

•   DIRECTORY - associated with one directory.

•   TARGET - associated with one target.

•   SOURCE - associated with one source file.

•   TEST - associated with a test named with add_test().

•   VARIABLE - documents a CMake language variable.

•   CACHED_VARIABLE - documents a CMake cache variable.

    Note that unlike set_property() and get_property() no actual scope needs to be given; only the kind of scope is important.

    The required PROPERTY option is immediately followed by the name of the property being defined.

    If the INHERITED option is given, then the get_property() command will chain up to the next higher scope when the requested property is not set in the scope given to the command.

•   DIRECTORY scope chains to its parent directory's scope, continuing the walk up parent directories until a directory has the property set or there are no more parents. If still not found at the top level directory, it chains to the GLOBAL scope.

•   TARGET, SOURCE and TEST properties chain to DIRECTORY scope, including further chaining up the directories, etc. as needed.

    Note that this scope chaining behavior only applies to calls to get_property(), get_directory_property(), get_target_property(), get_source_file_property() and get_test_property(). There is no inheriting behavior when setting properties, so using APPEND or APPEND_STRING with the set_property() command will not consider inherited values when working out the contents to append to.

    The BRIEF_DOCS and FULL_DOCS options are followed by strings to be associated with the property as its brief and full documentation. CMake does not use this documentation other than making it available to the project via corresponding options to the get_property() command.

    Changed in version 3.23: The BRIEF_DOCS and FULL_DOCS options are optional.

    Added in version 3.23: The INITIALIZE_FROM_VARIABLE option specifies a variable from which the property should be initialized. It can only be used with target properties. The <variable> name must end with the property name and must not begin with CMAKE_ or _CMAKE_. The property name must contain at least one underscore. It is recommended that the property name have a prefix specific to the project.

  Property Redefinition

Once a property is defined for a particular type of scope, it cannot be redefined. Attempts to redefine an existing property by calling define_property() with the same scope type and property name will be silently ignored. Defining the same property name for two different kinds of scope is valid.

get_property() can be used to determine whether a property is already defined for a particular kind of scope, and if so, to examine its definition. For example:

    # Initial definition
    define_property(TARGET PROPERTY MY_NEW_PROP
      BRIEF_DOCS "My new custom property"
    )
    # Later examination
    get_property(my_new_prop_exists
      TARGET NONE
      PROPERTY MY_NEW_PROP
      DEFINED
    )
    if(my_new_prop_exists)
      get_property(my_new_prop_docs
        TARGET NONE
        PROPERTY MY_NEW_PROP
        BRIEF_DOCS
      )
      # ${my_new_prop_docs} is now set to "My new custom property"
    endif()

  See Also

•   get_property()

•   set_property()

  enable_language

Enable languages (CXX/C/OBJC/OBJCXX/Fortran/etc)

    enable_language(<lang>... [OPTIONAL])

Enables support for the named languages in CMake. This is the same as the project() command but does not create any of the extra variables that are created by the project() command.

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. Added in version 3.8: Added CSharp and CUDA support.

Added in version 3.15: Added Swift support.

Added in version 3.16: Added OBJC and OBJCXX support.

Added in version 3.18: Added ISPC support.

Added in version 3.21: Added HIP support.

Added 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.

The following restrictions apply to where enable_language() may be called:

•   It must be called in file scope, not in a function call.

•   It must not be called before the first call to project(). See policy CMP0165.

•   It must be called in the highest directory common to all targets using the named language directly for compiling sources or indirectly through link dependencies. It is simplest to enable all needed languages in the top-level directory of a project.

    The OPTIONAL keyword is a placeholder for future implementation and does not currently work. Instead you can use the CheckLanguage module to verify support before enabling.

  enable_testing

Enable testing for current directory and below.

    enable_testing()

Enables testing for this directory and below.

This command should be in the top-level source directory because ctest(1) expects to find a test file in the top-level build directory.

This command is automatically invoked when the CTest module is included, except if the BUILD_TESTING option is turned off.

See also the add_test() command.

  export

Export targets or packages for outside projects to use them directly from the current project's build tree, without installation.

See the install(EXPORT) command to export targets from an install tree.

  Synopsis

    export(TARGETS <target>... [...])
    export(EXPORT <export-name> [...])
    export(PACKAGE <PackageName>)
    export(SETUP <export-name> [...])

  Exporting Targets

export(TARGETS <target>... [...])

        export(TARGETS <target>... [NAMESPACE <namespace>]
               [APPEND] FILE <filename> [EXPORT_LINK_INTERFACE_LIBRARIES]
               [CXX_MODULES_DIRECTORY <directory>])

    Creates a file <filename> that may be included by outside projects to import targets named by <target>... from the current project's build tree. This is useful during cross-compiling to build utility executables that can run on the host platform in one project and then import them into another project being compiled for the target platform.

    The file created by this command is specific to the build tree and should never be installed. See the install(EXPORT) command to export targets from an install tree.

    The options are:

NAMESPACE <namespace>
    Prepend the <namespace> string to all target names written to the file.

APPEND
    Append to the file instead of overwriting it. This can be used to incrementally export multiple targets to the same file.

EXPORT_LINK_INTERFACE_LIBRARIES
    Include the contents of the properties named with the pattern (IMPORTED_)?LINK_INTERFACE_LIBRARIES(_<CONFIG>)? in the export, even when policy CMP0022 is NEW. This is useful to support consumers using CMake versions older than 2.8.12.

CXX_MODULES_DIRECTORY <directory>
    Added in version 3.28.

    Export C++ module properties to files under the given directory. Each file will be named according to the target's export name (without any namespace). These files will automatically be included from the export file.

    This signature requires all targets to be listed explicitly. If a library target is included in the export, but a target to which it links is not included, the behavior is unspecified. See the export(EXPORT) signature to automatically export the same targets from the build tree as install(EXPORT) would from an install tree.

    NOTE: Object Libraries under Xcode have special handling if multiple architectures are listed in CMAKE_OSX_ARCHITECTURES. In this case they will be exported as Interface Libraries with no object files available to clients. This is sufficient to satisfy transitive usage requirements of other targets that link to the object libraries in their implementation.

    This command exports all Build Configurations from the build tree. See the CMAKE_MAP_IMPORTED_CONFIG_<CONFIG> variable to map configurations of dependent projects to the exported configurations.

  Exporting Targets to Android.mk

    export(TARGETS <target>... ANDROID_MK <filename>)

Added in version 3.7.

This signature exports cmake built targets to the android ndk build system by creating an Android.mk file that references the prebuilt targets. The Android NDK supports the use of prebuilt libraries, both static and shared. This allows cmake to build the libraries of a project and make them available to an ndk build system complete with transitive dependencies, include flags and defines required to use the libraries. The signature takes a list of targets and puts them in the Android.mk file specified by the <filename> given. This signature can only be used if policy CMP0022 is NEW for all targets given. A error will be issued if that policy is set to OLD for one of the targets.

  Exporting Targets matching install(EXPORT)

export(EXPORT <export-name> [...])

        export(EXPORT <export-name> [NAMESPACE <namespace>] [FILE <filename>]
               [CXX_MODULES_DIRECTORY <directory>] [EXPORT_PACKAGE_DEPENDENCIES])

    Creates a file <filename> that may be included by outside projects to import targets from the current project's build tree. This is the same as the export(TARGETS) signature, except that the targets are not explicitly listed. Instead, it exports the targets associated with the installation export <export-name>. Target installations may be associated with the export <export-name> using the EXPORT option of the install(TARGETS) command.

EXPORT_PACKAGE_DEPENDENCIES

    NOTE: Experimental. Gated by CMAKE_EXPERIMENTAL_EXPORT_PACKAGE_DEPENDENCIES.

    Specify that find_dependency() calls should be exported. See install(EXPORT) for details on how this works.

  Exporting Packages

export(PACKAGE <PackageName>)

        export(PACKAGE <PackageName>)

    Store the current build directory in the CMake user package registry for package <PackageName>. The find_package() command may consider the directory while searching for package <PackageName>. This helps dependent projects find and use a package from the current project's build tree without help from the user. Note that the entry in the package registry that this command creates works only in conjunction with a package configuration file (<PackageName>Config.cmake) that works with the build tree. In some cases, for example for packaging and for system wide installations, it is not desirable to write the user package registry.

    Changed in version 3.1: If the CMAKE_EXPORT_NO_PACKAGE_REGISTRY variable is enabled, the export(PACKAGE) command will do nothing.

    Changed in version 3.15: By default the export(PACKAGE) command does nothing (see policy CMP0090) because populating the user package registry has effects outside the source and build trees. Set the CMAKE_EXPORT_PACKAGE_REGISTRY variable to add build directories to the CMake user package registry.

  Configuring Exports

export(SETUP <export-name> [...])

        export(SETUP <export-name>
               [PACKAGE_DEPENDENCY <dep>
                [ENABLED (<bool-true>|<bool-false>|AUTO)]
                [EXTRA_ARGS <args>...]
               ] [...]
               [TARGET <target>
                [XCFRAMEWORK_LOCATION <location>]
               ] [...]
               )

    Added in version 3.29.

    Configure the parameters of an export. The arguments are as follows:

PACKAGE_DEPENDENCY <dep>

    NOTE: Experimental. Gated by CMAKE_EXPERIMENTAL_EXPORT_PACKAGE_DEPENDENCIES.

    Specify a package dependency to configure. This changes how find_dependency() calls are written during export(EXPORT) and install(EXPORT). <dep> is the name of a package to export. This argument accepts the following additional arguments:

ENABLED
    Manually control whether or not the dependency is exported. This accepts the following values:

<bool-true>
    Any value that CMake recognizes as "true". Always export the dependency, even if no exported targets depend on it. This can be used to manually add find_dependency() calls to the export.

<bool-false>
    Any value that CMake recognizes as "false". Never export the dependency, even if an exported target depends on it.

AUTO
    Only export the dependency if an exported target depends on it.

EXTRA_ARGS <args>
    Specify additional arguments to pass to find_dependency() after the REQUIRED argument.

TARGET <target>
    Specify a target to configure in this export. This argument accepts the following additional arguments:

XCFRAMEWORK_LOCATION
    Specify the location of an .xcframework which contains the library from this target. If specified, the generated code will check to see if the .xcframework exists, and if it does, it will use the .xcframework as its imported location instead of the installed library.

  fltk_wrap_ui

Create FLTK user interfaces Wrappers.

    fltk_wrap_ui(resultingLibraryName source1
                 source2 ... sourceN)

Produce .h and .cxx files for all the .fl and .fld files listed. The resulting .h and .cxx files will be added to a variable named resultingLibraryName_FLTK_UI_SRCS which should be added to your library.

  get_source_file_property

Get a property for a source file.

    get_source_file_property(<variable> <file>
                             [DIRECTORY <dir> | TARGET_DIRECTORY <target>]
                             <property>)

Gets a property from a source file. The value of the property is stored in the specified <variable>. If the <file> is not a source file, or the source property is not found, <variable> will be set to NOTFOUND. If the source property was defined to be an INHERITED property (see define_property()), the search will include the relevant parent scopes, as described for the define_property() command.

By default, the source file's property will be read from the current source directory's scope.

Added in version 3.18: Directory scope can be overridden with one of the following sub-options:

DIRECTORY <dir>
    The source file property will be read from the <dir> directory's scope. CMake must already know about that source directory, either by having added it through a call to add_subdirectory() or <dir> being the top level source directory. Relative paths are treated as relative to the current source directory.

TARGET_DIRECTORY <target>
    The source file property will be read from the directory scope in which <target> was created (<target> must therefore already exist).

    Use set_source_files_properties() to set property values. Source file properties usually control how the file is built. One property that is always there is LOCATION.

    NOTE: The GENERATED source file property may be globally visible. See its documentation for details.

  See Also

•   define_property()

•   the more general get_property() command

•   set_source_files_properties()

  get_target_property

Get a property from a target.

    get_target_property(<variable> <target> <property>)

Get a property from a target. The value of the property is stored in the specified <variable>. If the target property is not found, <variable> will be set to <variable>-NOTFOUND. If the target property was defined to be an INHERITED property (see define_property()), the search will include the relevant parent scopes, as described for the define_property() command.

Use set_target_properties() to set target property values. Properties are usually used to control how a target is built, but some query the target instead. This command can get properties for any target so far created. The targets do not need to be in the current CMakeLists.txt file.

  See Also

•   define_property()

•   the more general get_property() command

•   set_target_properties()

•   Properties on Targets for the list of properties known to CMake

  get_test_property

Get a property of the test.

    get_test_property(<test> <property> [DIRECTORY <dir>] <variable>)

Get a property from the test. The value of the property is stored in the specified <variable>. If the <test> is not defined, or the test property is not found, <variable> will be set to NOTFOUND. If the test property was defined to be an INHERITED property (see define_property()), the search will include the relevant parent scopes, as described for the define_property() command.

For a list of standard properties you can type cmake --help-property-list.

Added in version 3.28: Directory scope can be overridden with the following sub-option:

DIRECTORY <dir>
    The test property will be read from the <dir> directory's scope. CMake must already know about that source directory, either by having added it through a call to add_subdirectory() or <dir> being the top level source directory. Relative paths are treated as relative to the current source directory. <dir> may reference a binary directory.

  See Also

•   define_property()

•   the more general get_property() command

  include_directories

Add include directories to the build.

    include_directories([AFTER|BEFORE] [SYSTEM] dir1 [dir2 ...])

Add the given directories to those the compiler uses to search for include files. Relative paths are interpreted as relative to the current source directory.

The include directories are added to the INCLUDE_DIRECTORIES directory property for the current CMakeLists file. They are also added to the INCLUDE_DIRECTORIES target property for each target in the current CMakeLists file. The target property values are the ones used by the generators.

By default the directories specified are appended onto the current list of directories. This default behavior can be changed by setting CMAKE_INCLUDE_DIRECTORIES_BEFORE to ON. By using AFTER or BEFORE explicitly, you can select between appending and prepending, independent of the default.

If the SYSTEM option is given, the compiler will be told the directories are meant as system include directories on some platforms. Signaling this setting might achieve effects such as the compiler skipping warnings, or these fixed-install system files not being considered in dependency calculations - see compiler docs.

Arguments to include_directories may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

NOTE: Prefer the target_include_directories() command to add include directories to individual targets and optionally propagate/export them to dependents.

  See Also

•   target_include_directories()

  include_external_msproject

Include an external Microsoft project file in the solution file produced by Visual Studio Generators. Ignored on other generators.

    include_external_msproject(projectname location
                               [TYPE projectTypeGUID]
                               [GUID projectGUID]
                               [PLATFORM platformName]
                               dep1 dep2 ...)

Includes an external Microsoft project in the generated solution file. This will create a target named [projectname]. This can be used in the add_dependencies() command to make things depend on the external project.

TYPE, GUID and PLATFORM are optional parameters that allow one to specify the type of project, id (GUID) of the project and the name of the target platform. This is useful for projects requiring values other than the default (e.g. WIX projects).

Added in version 3.9: If the imported project has different configuration names than the current project, set the MAP_IMPORTED_CONFIG_<CONFIG> target property to specify the mapping.

  include_regular_expression

Set the regular expression used for dependency checking.

    include_regular_expression(regex_match [regex_complain])

Sets the regular expressions used in dependency checking. Only files matching regex_match will be traced as dependencies. Only files matching regex_complain will generate warnings if they cannot be found (standard header paths are not searched).

The default for regex_match is "^.*$" (match everything). The default for regex_complain is "^$" (match empty string only).

  install

Specify rules to run at install time.

  Synopsis

    install(TARGETS <target>... [...])
    install(IMPORTED_RUNTIME_ARTIFACTS <target>... [...])
    install({FILES | PROGRAMS} <file>... [...])
    install(DIRECTORY <dir>... [...])
    install(SCRIPT <file> [...])
    install(CODE <code> [...])
    install(EXPORT <export-name> [...])
    install(PACKAGE_INFO <package-name> [...])
    install(RUNTIME_DEPENDENCY_SET <set-name> [...])

  Introduction

This command generates installation rules for a project. Install rules specified by calls to the install() command within a source directory are executed in order during installation.

Changed in version 3.14: Install rules in subdirectories added by calls to the add_subdirectory() command are interleaved with those in the parent directory to run in the order declared (see policy CMP0082).

Changed in version 3.22: The environment variable CMAKE_INSTALL_MODE can override the default copying behavior of install().

Changed in version 3.31: Projects can enable INSTALL_PARALLEL to enable a parallel installation. When using the parallel install, subdirectories added by calls to the add_subdirectory() command are installed independently and the order that install rules added in different subdirectories will run is not guaranteed.

There are multiple signatures for this command. Some of them define installation options for files and targets. Options common to multiple signatures are covered here but they are valid only for signatures that specify them. The common options are:

DESTINATION <dir>
    Specify the directory on disk to which a file will be installed. <dir> should be a relative path. An absolute path is allowed, but not recommended.

    When a relative path is given, it is interpreted relative to the value of the CMAKE_INSTALL_PREFIX variable. The prefix can be relocated at install time using the DESTDIR mechanism explained in the CMAKE_INSTALL_PREFIX variable documentation.

    As absolute paths do not work with the cmake --install command's --prefix option, or with the cpack installer generators, it is strongly recommended to use relative paths throughout for best support by package maintainers. In particular, there is no need to make paths absolute by prepending CMAKE_INSTALL_PREFIX; this prefix is used by default if the DESTINATION is a relative path.

    If an absolute path (with a leading slash or drive letter) is given it is used verbatim.

    Changed in version 3.31: <dir> will be normalized according to the same normalization rules as the cmake_path() command.

PERMISSIONS <permission>...
    Specify permissions for installed files. Valid permissions are OWNER_READ, OWNER_WRITE, OWNER_EXECUTE, GROUP_READ, GROUP_WRITE, GROUP_EXECUTE, WORLD_READ, WORLD_WRITE, WORLD_EXECUTE, SETUID, and SETGID. Permissions that do not make sense on certain platforms are ignored on those platforms.

    If this option is used multiple times in a single call, its list of permissions accumulates. If an install(TARGETS) call uses <artifact-kind> arguments, a separate list of permissions is accumulated for each kind of artifact.

CONFIGURATIONS <config>...
    Specify a list of build configurations for which the install rule applies (Debug, Release, etc.).

    If this option is used multiple times in a single call, its list of configurations accumulates. If an install(TARGETS) call uses <artifact-kind> arguments, a separate list of configurations is accumulated for each kind of artifact.

COMPONENT <component>
    Specify an installation component name with which the install rule is associated, such as Runtime or Development. During component-specific installation only install rules associated with the given component name will be executed. During a full installation all components are installed unless marked with EXCLUDE_FROM_ALL. If COMPONENT is not provided a default component "Unspecified" is created. The default component name may be controlled with the CMAKE_INSTALL_DEFAULT_COMPONENT_NAME variable.

    Installation components can be then used by the cmake --install command's --component option and the CPackComponent module. Global target list_install_components lists all available components.

EXCLUDE_FROM_ALL
    Added in version 3.6.

    Specify that the file is excluded from a full installation and only installed as part of a component-specific installation

OPTIONAL
    Specify that it is not an error if the file to be installed does not exist.

    Added in version 3.1: Command signatures that install files may print messages during installation. Use the CMAKE_INSTALL_MESSAGE variable to control which messages are printed.

    Added in version 3.11: Many of the install() variants implicitly create the directories containing the installed files. If CMAKE_INSTALL_DEFAULT_DIRECTORY_PERMISSIONS is set, these directories will be created with the permissions specified. Otherwise, they will be created according to the uname rules on Unix-like platforms. Windows platforms are unaffected.

  Signatures

install(TARGETS <target>... [...])
    Install target Output Artifacts and associated files:

        install(TARGETS <target>... [EXPORT <export-name>]
                [RUNTIME_DEPENDENCIES <arg>...|RUNTIME_DEPENDENCY_SET <set-name>]
                [<artifact-option>...]
                [<artifact-kind> <artifact-option>...]...
                [INCLUDES DESTINATION [<dir> ...]]
                )

    where <artifact-option>... group may contain:

        [DESTINATION <dir>]
        [PERMISSIONS <permission>...]
        [CONFIGURATIONS <config>...]
        [COMPONENT <component>]
        [NAMELINK_COMPONENT <component>]
        [OPTIONAL] [EXCLUDE_FROM_ALL]
        [NAMELINK_ONLY|NAMELINK_SKIP]

    The first <artifact-option>... group applies to target Output Artifacts that do not have a dedicated group specified later in the same call.

    Each <artifact-kind> <artifact-option>... group applies to Output Artifacts of the specified artifact kind:

ARCHIVE
    Target artifacts of this kind include:

•   Static libraries (except on macOS when marked as FRAMEWORK, see below);

•   DLL import libraries (on all Windows-based systems including Cygwin; they have extension .lib, in contrast to the .dll libraries that go to RUNTIME);

•   On AIX, the linker import file created for executables with ENABLE_EXPORTS enabled.

•   On macOS, the linker import file created for shared libraries with ENABLE_EXPORTS enabled (except when marked as FRAMEWORK, see below).

LIBRARY
    Target artifacts of this kind include:

•   Shared libraries, except

•   DLLs (these go to RUNTIME, see below),

•   on macOS when marked as FRAMEWORK (see below).

RUNTIME
    Target artifacts of this kind include:

•   Executables (except on macOS when marked as MACOSX_BUNDLE, see BUNDLE below);

•   DLLs (on all Windows-based systems including Cygwin; note that the accompanying import libraries are of kind ARCHIVE).

OBJECTS
    Added in version 3.9.

    Object files associated with object libraries.

FRAMEWORK
    Both static and shared libraries marked with the FRAMEWORK property are treated as FRAMEWORK targets on macOS.

BUNDLE
    Executables marked with the MACOSX_BUNDLE property are treated as BUNDLE targets on macOS.

PUBLIC_HEADER
    Any PUBLIC_HEADER files associated with a library are installed in the destination specified by the PUBLIC_HEADER argument on non-Apple platforms. Rules defined by this argument are ignored for FRAMEWORK libraries on Apple platforms because the associated files are installed into the appropriate locations inside the framework folder. See PUBLIC_HEADER for details.

PRIVATE_HEADER
    Similar to PUBLIC_HEADER, but for PRIVATE_HEADER files. See PRIVATE_HEADER for details.

RESOURCE
    Similar to PUBLIC_HEADER and PRIVATE_HEADER, but for RESOURCE files. See RESOURCE for details.

FILE_SET <set-name>
    Added in version 3.23.

    File sets are defined by the target_sources(FILE_SET) command. If the file set <set-name> exists and is PUBLIC or INTERFACE, any files in the set are installed under the destination (see below). The directory structure relative to the file set's base directories is preserved. For example, a file added to the file set as /blah/include/myproj/here.h with a base directory /blah/include would be installed to myproj/here.h below the destination.

CXX_MODULES_BMI
    Added in version 3.28.

    Any module files from C++ modules from PUBLIC sources in a file set of type CXX_MODULES will be installed to the given DESTINATION. All modules are placed directly in the destination as no directory structure is derived from the names of the modules. An empty DESTINATION may be used to suppress installing these files (for use in generic code).

    For regular executables, static libraries and shared libraries, the DESTINATION argument is not required. For these target types, when DESTINATION is omitted, a default destination will be taken from the appropriate variable from GNUInstallDirs, or set to a built-in default value if that variable is not defined. The same is true for file sets, and the public and private headers associated with the installed targets through the PUBLIC_HEADER and PRIVATE_HEADER target properties. A destination must always be provided for module libraries, Apple bundles and frameworks. A destination can be omitted for interface and object libraries, but they are handled differently (see the discussion of this topic toward the end of this section).

    For shared libraries on DLL platforms, if neither RUNTIME nor ARCHIVE destinations are specified, both the RUNTIME and ARCHIVE components are installed to their default destinations. If either a RUNTIME or ARCHIVE destination is specified, the component is installed to that destination, and the other component is not installed. If both RUNTIME and ARCHIVE destinations are specified, then both components are installed to their respective destinations.

    The following table shows the target types with their associated variables and built-in defaults that apply when no destination is given:
    Target Type | GNUInstallDirs Variable | Built-In Default
    RUNTIME | ${CMAKE_INSTALL_BINDIR} | bin
    LIBRARY | ${CMAKE_INSTALL_LIBDIR} | lib
    ARCHIVE | ${CMAKE_INSTALL_LIBDIR} | lib
    PRIVATE_HEADER | ${CMAKE_INSTALL_INCLUDEDIR} | include
    PUBLIC_HEADER | ${CMAKE_INSTALL_INCLUDEDIR} | include
    FILE_SET (type HEADERS) | ${CMAKE_INSTALL_INCLUDEDIR} | include

    Projects wishing to follow the common practice of installing headers into a project-specific subdirectory may prefer using file sets with appropriate paths and base directories. Otherwise, they must provide a DESTINATION instead of being able to rely on the above (see next example below).

    To make packages compliant with distribution filesystem layout policies, if projects must specify a DESTINATION, it is strongly recommended that they use a path that begins with the appropriate relative GNUInstallDirs variable. This allows package maintainers to control the install destination by setting the appropriate cache variables. The following example shows a static library being installed to the default destination provided by GNUInstallDirs, but with its headers installed to a project-specific subdirectory without using file sets:

        add_library(mylib STATIC ...)
        set_target_properties(mylib PROPERTIES PUBLIC_HEADER mylib.h)
        include(GNUInstallDirs)
        install(TARGETS mylib
                PUBLIC_HEADER
                  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/myproj
        )

    In addition to the common options listed above, each target can accept the following additional arguments:

NAMELINK_COMPONENT
    Added in version 3.12.

    On some platforms a versioned shared library has a symbolic link such as:

        lib<name>.so -> lib<name>.so.1

    where lib<name>.so.1 is the soname of the library and lib<name>.so is a "namelink" allowing linkers to find the library when given -l<name>. The NAMELINK_COMPONENT option is similar to the COMPONENT option, but it changes the installation component of a shared library namelink if one is generated. If not specified, this defaults to the value of COMPONENT. It is an error to use this parameter outside of a LIBRARY block.

    Changed in version 3.27: This parameter is also usable for an ARCHIVE block to manage the linker import file created, on macOS, for shared libraries with ENABLE_EXPORTS enabled.

    See the Example: Install Targets with Per-Artifact Components for an example using NAMELINK_COMPONENT.

    This option is typically used for package managers that have separate runtime and development packages. For example, on Debian systems, the library is expected to be in the runtime package, and the headers and namelink are expected to be in the development package.

    See the VERSION and SOVERSION target properties for details on creating versioned shared libraries.

NAMELINK_ONLY
    This option causes the installation of only the namelink when a library target is installed. On platforms where versioned shared libraries do not have namelinks or when a library is not versioned, the NAMELINK_ONLY option installs nothing. It is an error to use this parameter outside of a LIBRARY block.

    Changed in version 3.27: This parameter is also usable for an ARCHIVE block to manage the linker import file created, on macOS, for shared libraries with ENABLE_EXPORTS enabled.

    When NAMELINK_ONLY is given, either NAMELINK_COMPONENT or COMPONENT may be used to specify the installation component of the namelink, but COMPONENT should generally be preferred.

NAMELINK_SKIP
    Similar to NAMELINK_ONLY, but it has the opposite effect: it causes the installation of library files other than the namelink when a library target is installed. When neither NAMELINK_ONLY or NAMELINK_SKIP are given, both portions are installed. On platforms where versioned shared libraries do not have symlinks or when a library is not versioned, NAMELINK_SKIP installs the library. It is an error to use this parameter outside of a LIBRARY block.

    Changed in version 3.27: This parameter is also usable for an ARCHIVE block to manage the linker import file created, on macOS, for shared libraries with ENABLE_EXPORTS enabled.

    If NAMELINK_SKIP is specified, NAMELINK_COMPONENT has no effect. It is not recommended to use NAMELINK_SKIP in conjunction with NAMELINK_COMPONENT.

    The install(TARGETS) command can also accept the following options at the top level:

EXPORT
    This option associates the installed target files with an export called <export-name>. It must appear before any target options. To actually install the export file itself, call install(EXPORT), documented below. See documentation of the EXPORT_NAME target property to change the name of the exported target.

    If EXPORT is used and the targets include PUBLIC or INTERFACE file sets, all of them must be specified with FILE_SET arguments. All PUBLIC or INTERFACE file sets associated with a target are included in the export.

INCLUDES DESTINATION
    This option specifies a list of directories which will be added to the INTERFACE_INCLUDE_DIRECTORIES target property of the <targets> when exported by the install(EXPORT) command. If a relative path is specified, it is treated as relative to the $<INSTALL_PREFIX>.

    Unlike other DESTINATION arguments for the various install() subcommands, paths given after INCLUDES DESTINATION are used as given. They are not normalized, nor assumed to be normalized, although it is recommended that they are given in normalized form (see Normalization).

RUNTIME_DEPENDENCY_SET <set-name>
    Added in version 3.21.

    This option causes all runtime dependencies of installed executable, shared library, and module targets to be added to the specified runtime dependency set. This set can then be installed with an install(RUNTIME_DEPENDENCY_SET) command.

    This keyword and the RUNTIME_DEPENDENCIES keyword are mutually exclusive.

RUNTIME_DEPENDENCIES <arg>...
    Added in version 3.21.

    This option causes all runtime dependencies of installed executable, shared library, and module targets to be installed along with the targets themselves. The RUNTIME, LIBRARY, FRAMEWORK, and generic arguments are used to determine the properties (DESTINATION, COMPONENT, etc.) of the installation of these dependencies.

    RUNTIME_DEPENDENCIES is semantically equivalent to the following pair of calls:

        install(TARGETS ... RUNTIME_DEPENDENCY_SET <set-name>)
        install(RUNTIME_DEPENDENCY_SET <set-name> <arg>...)

    where <set-name> will be a randomly generated set name. <arg>... may include any of the following keywords supported by the install(RUNTIME_DEPENDENCY_SET) command:

•   DIRECTORIES

•   PRE_INCLUDE_REGEXES

•   PRE_EXCLUDE_REGEXES

•   POST_INCLUDE_REGEXES

•   POST_EXCLUDE_REGEXES

•   POST_INCLUDE_FILES

•   POST_EXCLUDE_FILES

    The RUNTIME_DEPENDENCIES and RUNTIME_DEPENDENCY_SET keywords are mutually exclusive.

    Interface Libraries may be listed among the targets to install. They install no artifacts but will be included in an associated EXPORT. If Object Libraries are listed but given no destination for their object files, they will be exported as Interface Libraries. This is sufficient to satisfy transitive usage requirements of other targets that link to the object libraries in their implementation.

    Installing a target with the EXCLUDE_FROM_ALL target property set to TRUE has undefined behavior.

    Added in version 3.3: An install destination given as a DESTINATION argument may use "generator expressions" with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions.

    Added in version 3.13: install(TARGETS) can install targets that were created in other directories. When using such cross-directory install rules, running make install (or similar) from a subdirectory will not guarantee that targets from other directories are up-to-date. You can use target_link_libraries() or add_dependencies() to ensure that such out-of-directory targets are built before the subdirectory-specific install rules are run.

install(IMPORTED_RUNTIME_ARTIFACTS <target>... [...])
    Added in version 3.21.

    Install runtime artifacts of imported targets:

        install(IMPORTED_RUNTIME_ARTIFACTS <target>...
                [RUNTIME_DEPENDENCY_SET <set-name>]
                [[LIBRARY|RUNTIME|FRAMEWORK|BUNDLE]
                 [DESTINATION <dir>]
                 [PERMISSIONS <permission>...]
                 [CONFIGURATIONS <config>...]
                 [COMPONENT <component>]
                 [OPTIONAL] [EXCLUDE_FROM_ALL]
                ] [...]
                )

    The IMPORTED_RUNTIME_ARTIFACTS form specifies rules for installing the runtime artifacts of imported targets. Projects may do this if they want to bundle outside executables or modules inside their installation. The LIBRARY, RUNTIME, FRAMEWORK, and BUNDLE arguments have the same semantics that they do in the TARGETS mode. Only the runtime artifacts of imported targets are installed (except in the case of FRAMEWORK libraries, MACOSX_BUNDLE executables, and BUNDLE CFBundles.) For example, headers and import libraries associated with DLLs are not installed. In the case of FRAMEWORK libraries, MACOSX_BUNDLE executables, and BUNDLE CFBundles, the entire directory is installed.

    The RUNTIME_DEPENDENCY_SET option causes the runtime artifacts of the imported executable, shared library, and module library targets to be added to the <set-name> runtime dependency set. This set can then be installed with an install(RUNTIME_DEPENDENCY_SET) command.

install(FILES <file>... [...])

install(PROGRAMS <program>... [...])

    NOTE: If installing header files, consider using file sets defined by target_sources(FILE_SET) instead. File sets associate headers with a target and they install as part of the target.

    Install files or programs:

        install(<FILES|PROGRAMS> <file>...
                TYPE <type> | DESTINATION <dir>
                [PERMISSIONS <permission>...]
                [CONFIGURATIONS <config>...]
                [COMPONENT <component>]
                [RENAME <name>] [OPTIONAL] [EXCLUDE_FROM_ALL])

    The FILES form specifies rules for installing files for a project. File names given as relative paths are interpreted with respect to the current source directory. Files installed by this form are by default given permissions OWNER_WRITE, OWNER_READ, GROUP_READ, and WORLD_READ if no PERMISSIONS argument is given.

    The PROGRAMS form is identical to the FILES form except that the default permissions for the installed file also include OWNER_EXECUTE, GROUP_EXECUTE, and WORLD_EXECUTE. This form is intended to install programs that are not targets, such as shell scripts. Use the TARGETS form to install targets built within the project.

    The list of files... given to FILES or PROGRAMS may use "generator expressions" with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. However, if any item begins in a generator expression it must evaluate to a full path.

    The optional RENAME <name> argument is used to specify a name for the installed file that is different from the original file name. Renaming is allowed only when a single file is installed by the command.

    Either a TYPE or a DESTINATION must be provided, but not both. A TYPE argument specifies the generic file type of the files being installed. A destination will then be set automatically by taking the corresponding variable from GNUInstallDirs, or by using a built-in default if that variable is not defined. See the table below for the supported file types and their corresponding variables and built-in defaults. Projects can provide a DESTINATION argument instead of a file type if they wish to explicitly define the install destination.
    TYPE Argument | GNUInstallDirs Variable | Built-In Default
    BIN | ${CMAKE_INSTALL_BINDIR} | bin
    SBIN | ${CMAKE_INSTALL_SBINDIR} | sbin
    LIB | ${CMAKE_INSTALL_LIBDIR} | lib
    INCLUDE | ${CMAKE_INSTALL_INCLUDEDIR} | include
    SYSCONF | ${CMAKE_INSTALL_SYSCONFDIR} | etc
    SHAREDSTATE | ${CMAKE_INSTALL_SHARESTATEDIR} | com
    LOCALSTATE | ${CMAKE_INSTALL_LOCALSTATEDIR} | var
    RUNSTATE | ${CMAKE_INSTALL_RUNSTATEDIR} | <LOCALSTATE dir>/run
    DATA | ${CMAKE_INSTALL_DATADIR} | <DATAROOT dir>
    INFO | ${CMAKE_INSTALL_INFODIR} | <DATAROOT dir>/info
    LOCALE | ${CMAKE_INSTALL_LOCALEDIR} | <DATAROOT dir>/locale
    MAN | ${CMAKE_INSTALL_MANDIR} | <DATAROOT dir>/man
    DOC | ${CMAKE_INSTALL_DOCDIR} | <DATAROOT dir>/doc
    LIBEXEC | ${CMAKE_INSTALL_LIBEXECDIR} | libexec

    Projects wishing to follow the common practice of installing headers into a project-specific subdirectory will need to provide a destination rather than rely on the above. Using file sets for headers instead of install(FILES) would be even better (see target_sources(FILE_SET)).

    Note that some of the types' built-in defaults use the DATAROOT directory as a prefix. The DATAROOT prefix is calculated similarly to the types, with CMAKE_INSTALL_DATAROOTDIR as the variable and share as the built-in default. You cannot use DATAROOT as a TYPE parameter; please use DATA instead.

    To make packages compliant with distribution filesystem layout policies, if projects must specify a DESTINATION, it is strongly recommended that they use a path that begins with the appropriate relative GNUInstallDirs variable. This allows package maintainers to control the install destination by setting the appropriate cache variables. The following example shows how to follow this advice while installing an image to a project-specific documentation subdirectory:

        include(GNUInstallDirs)
        install(FILES logo.png
                DESTINATION ${CMAKE_INSTALL_DOCDIR}/myproj
        )

    Added in version 3.4: An install destination given as a DESTINATION argument may use "generator expressions" with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions.

    Added in version 3.20: An install rename given as a RENAME argument may use "generator expressions" with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions.

    Added in version 3.31: The TYPE argument now supports type LIBEXEC.

install(DIRECTORY <dir>... [...])

    NOTE: To install a directory sub-tree of headers, consider using file sets defined by target_sources(FILE_SET) instead. File sets not only preserve directory structure, they also associate headers with a target and install as part of the target.

    Install the contents of one or more directories:

        install(DIRECTORY dirs...
                TYPE <type> | DESTINATION <dir>
                [FILE_PERMISSIONS <permission>...]
                [DIRECTORY_PERMISSIONS <permission>...]
                [USE_SOURCE_PERMISSIONS] [OPTIONAL] [MESSAGE_NEVER]
                [CONFIGURATIONS <config>...]
                [COMPONENT <component>] [EXCLUDE_FROM_ALL]
                [FILES_MATCHING]
                [[PATTERN <pattern> | REGEX <regex>]
                 [EXCLUDE] [PERMISSIONS <permission>...]] [...])

    The DIRECTORY form installs contents of one or more directories to a given destination. The directory structure is copied verbatim to the destination. The last component of each directory name is appended to the destination directory but a trailing slash may be used to avoid this because it leaves the last component empty. Directory names given as relative paths are interpreted with respect to the current source directory. If no input directory names are given the destination directory will be created but nothing will be installed into it. The FILE_PERMISSIONS and DIRECTORY_PERMISSIONS options specify permissions given to files and directories in the destination. If USE_SOURCE_PERMISSIONS is specified and FILE_PERMISSIONS is not, file permissions will be copied from the source directory structure. If no permissions are specified files will be given the default permissions specified in the FILES form of the command, and the directories will be given the default permissions specified in the PROGRAMS form of the command.

    Added in version 3.1: The MESSAGE_NEVER option disables file installation status output.

    Installation of directories may be controlled with fine granularity using the PATTERN or REGEX options. These "match" options specify a globbing pattern or regular expression to match directories or files encountered within input directories. They may be used to apply certain options (see below) to a subset of the files and directories encountered. The full path to each input file or directory (with forward slashes) is matched against the expression. A PATTERN will match only complete file names: the portion of the full path matching the pattern must occur at the end of the file name and be preceded by a slash. A REGEX will match any portion of the full path but it may use / and $ to simulate the PATTERN behavior. By default all files and directories are installed whether or not they are matched. The FILES_MATCHING option may be given before the first match option to disable installation of files (but not directories) not matched by any expression. For example, the code

        install(DIRECTORY src/ DESTINATION doc/myproj
                FILES_MATCHING PATTERN "*.png")

    will extract and install images from a source tree.

    Some options may follow a PATTERN or REGEX expression as described under string(REGEX) and are applied only to files or directories matching them. The EXCLUDE option will skip the matched file or directory. The PERMISSIONS option overrides the permissions setting for the matched file or directory. For example the code

        install(DIRECTORY icons scripts/ DESTINATION share/myproj
                PATTERN "CVS" EXCLUDE
                PATTERN "scripts/*"
                PERMISSIONS OWNER_EXECUTE OWNER_WRITE OWNER_READ
                            GROUP_EXECUTE GROUP_READ)

    will install the icons directory to share/myproj/icons and the scripts directory to share/myproj. The icons will get default file permissions, the scripts will be given specific permissions, and any CVS directories will be excluded.

    Either a TYPE or a DESTINATION must be provided, but not both. A TYPE argument specifies the generic file type of the files within the listed directories being installed. A destination will then be set automatically by taking the corresponding variable from GNUInstallDirs, or by using a built-in default if that variable is not defined. See the table below for the supported file types and their corresponding variables and built-in defaults. Projects can provide a DESTINATION argument instead of a file type if they wish to explicitly define the install destination.
    TYPE Argument | GNUInstallDirs Variable | Built-In Default
    BIN | ${CMAKE_INSTALL_BINDIR} | bin
    SBIN | ${CMAKE_INSTALL_SBINDIR} | sbin
    LIB | ${CMAKE_INSTALL_LIBDIR} | lib
    INCLUDE | ${CMAKE_INSTALL_INCLUDEDIR} | include
    SYSCONF | ${CMAKE_INSTALL_SYSCONFDIR} | etc
    SHAREDSTATE | ${CMAKE_INSTALL_SHARESTATEDIR} | com
    LOCALSTATE | ${CMAKE_INSTALL_LOCALSTATEDIR} | var
    RUNSTATE | ${CMAKE_INSTALL_RUNSTATEDIR} | <LOCALSTATE dir>/run
    DATA | ${CMAKE_INSTALL_DATADIR} | <DATAROOT dir>
    INFO | ${CMAKE_INSTALL_INFODIR} | <DATAROOT dir>/info
    LOCALE | ${CMAKE_INSTALL_LOCALEDIR} | <DATAROOT dir>/locale
    MAN | ${CMAKE_INSTALL_MANDIR} | <DATAROOT dir>/man
    DOC | ${CMAKE_INSTALL_DOCDIR} | <DATAROOT dir>/doc
    LIBEXEC | ${CMAKE_INSTALL_LIBEXECDIR} | libexec

    Note that some of the types' built-in defaults use the DATAROOT directory as a prefix. The DATAROOT prefix is calculated similarly to the types, with CMAKE_INSTALL_DATAROOTDIR as the variable and share as the built-in default. You cannot use DATAROOT as a TYPE parameter; please use DATA instead.

    To make packages compliant with distribution filesystem layout policies, if projects must specify a DESTINATION, it is strongly recommended that they use a path that begins with the appropriate relative GNUInstallDirs variable. This allows package maintainers to control the install destination by setting the appropriate cache variables.

    Added in version 3.4: An install destination given as a DESTINATION argument may use "generator expressions" with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions.

    Added in version 3.5: The list of dirs... given to DIRECTORY may use "generator expressions" too.

    Added in version 3.31: The TYPE argument now supports type LIBEXEC.

install(SCRIPT <file> [...])

install(CODE <code> [...])
    Invoke CMake scripts or code during installation:

        install([[SCRIPT <file>] [CODE <code>]]
                [ALL_COMPONENTS | COMPONENT <component>]
                [EXCLUDE_FROM_ALL] [...])

    The SCRIPT form will invoke the given CMake script files during installation. If the script file name is a relative path it will be interpreted with respect to the current source directory. The CODE form will invoke the given CMake code during installation. Code is specified as a single argument inside a double-quoted string. For example, the code

        install(CODE "message(\"Sample install message.\")")

    will print a message during installation.

    Added in version 3.21: When the ALL_COMPONENTS option is given, the custom installation script code will be executed for every component of a component-specific installation. This option is mutually exclusive with the COMPONENT option.

    Added in version 3.14: <file> or <code> may use "generator expressions" with the syntax $<...> (in the case of <file>, this refers to their use in the file name, not the file's contents). See the cmake-generator-expressions(7) manual for available expressions.

install(EXPORT <export-name> [...])
    Install a CMake file exporting targets for dependent projects:

        install(EXPORT <export-name> DESTINATION <dir>
                [NAMESPACE <namespace>] [FILE <name>.cmake]
                [PERMISSIONS <permission>...]
                [CONFIGURATIONS <config>...]
                [CXX_MODULES_DIRECTORY <directory>]
                [EXPORT_LINK_INTERFACE_LIBRARIES]
                [COMPONENT <component>]
                [EXCLUDE_FROM_ALL]
                [EXPORT_PACKAGE_DEPENDENCIES])
        install(EXPORT_ANDROID_MK <export-name> DESTINATION <dir> [...])

    The EXPORT form generates and installs a CMake file containing code to import targets from the installation tree into another project. Target installations are associated with the export <export-name> using the EXPORT option of the install(TARGETS) signature documented above. The NAMESPACE option will prepend <namespace> to the target names as they are written to the import file. By default the generated file will be called <export-name>.cmake but the FILE option may be used to specify a different name. The value given to the FILE option must be a file name with the .cmake extension.

    If a CONFIGURATIONS option is given then the file will only be installed when one of the named configurations is installed. Additionally, the generated import file will reference only the matching target configurations. See the CMAKE_MAP_IMPORTED_CONFIG_<CONFIG> variable to map configurations of dependent projects to the installed configurations. The EXPORT_LINK_INTERFACE_LIBRARIES keyword, if present, causes the contents of the properties matching (IMPORTED_)?LINK_INTERFACE_LIBRARIES(_<CONFIG>)? to be exported, when policy CMP0022 is NEW.

    NOTE: The installed <export-name>.cmake file may come with additional per-configuration <export-name>-*.cmake files to be loaded by globbing. Do not use an export name that is the same as the package name in combination with installing a <package-name>-config.cmake file or the latter may be incorrectly matched by the glob and loaded.

    When a COMPONENT option is given, the listed <component> implicitly depends on all components mentioned in the export set. The exported <name>.cmake file will require each of the exported components to be present in order for dependent projects to build properly. For example, a project may define components Runtime and Development, with shared libraries going into the Runtime component and static libraries and headers going into the Development component. The export set would also typically be part of the Development component, but it would export targets from both the Runtime and Development components. Therefore, the Runtime component would need to be installed if the Development component was installed, but not vice versa. If the Development component was installed without the Runtime component, dependent projects that try to link against it would have build errors. Package managers, such as APT and RPM, typically handle this by listing the Runtime component as a dependency of the Development component in the package metadata, ensuring that the library is always installed if the headers and CMake export file are present.

    Added in version 3.7: In addition to cmake language files, the EXPORT_ANDROID_MK mode may be used to specify an export to the android ndk build system. This mode accepts the same options as the normal export mode. The Android NDK supports the use of prebuilt libraries, both static and shared. This allows cmake to build the libraries of a project and make them available to an ndk build system complete with transitive dependencies, include flags and defines required to use the libraries.

CXX_MODULES_DIRECTORY
    Added in version 3.28.

    Specify a subdirectory to store C++ module information for targets in the export set. This directory will be populated with files which add the necessary target property information to the relevant targets. Note that without this information, none of the C++ modules which are part of the targets in the export set will support being imported in consuming targets.

EXPORT_PACKAGE_DEPENDENCIES

    NOTE: Experimental. Gated by CMAKE_EXPERIMENTAL_EXPORT_PACKAGE_DEPENDENCIES.

    Specify that find_dependency() calls should be exported. If this argument is specified, CMake examines all targets in the export set and gathers their INTERFACE link targets. If any such targets either were found with find_package() or have the EXPORT_FIND_PACKAGE_NAME property set, and such package dependency was not disabled by passing ENABLED OFF to export(SETUP), then a find_dependency() call is written with the target's corresponding package name, a REQUIRED argument, and any additional arguments specified by the EXTRA_ARGS argument of export(SETUP). Any package dependencies that were manually specified by passing ENABLED ON to export(SETUP) are also added, even if the exported targets don't depend on any targets from them.

    The find_dependency() calls are written in the following order:

1.  Any package dependencies that were listed in export(SETUP) are written in the order they were first specified, regardless of whether or not they contain INTERFACE dependencies of the exported targets.

2.  Any package dependencies that contain INTERFACE link dependencies of the exported targets and that were never specified in export(SETUP) are written in the order they were first found.

    The EXPORT form is useful to help outside projects use targets built and installed by the current project. For example, the code

        install(TARGETS myexe EXPORT myproj DESTINATION bin)
        install(EXPORT myproj NAMESPACE mp_ DESTINATION lib/myproj)
        install(EXPORT_ANDROID_MK myproj DESTINATION share/ndk-modules)

    will install the executable myexe to <prefix>/bin and code to import it in the file <prefix>/lib/myproj/myproj.cmake and <prefix>/share/ndk-modules/Android.mk. An outside project may load this file with the include command and reference the myexe executable from the installation tree using the imported target name mp_myexe as if the target were built in its own tree.

install(PACKAGE_INFO <package-name> [...])
    Added in version 3.31.

    NOTE: Experimental. Gated by CMAKE_EXPERIMENTAL_EXPORT_PACKAGE_INFO.

    Installs a Common Package Specification file exporting targets for dependent projects:

        install(PACKAGE_INFO <package-name> EXPORT <export-name>
                [APPENDIX <appendix-name>]
                [DESTINATION <dir>]
                [LOWER_CASE_FILE]
                [VERSION <version>
                 [COMPAT_VERSION <version>]
                 [VERSION_SCHEMA <string>]]
                [DEFAULT_TARGETS <target>...]
                [DEFAULT_CONFIGURATIONS <config>...]
                [PERMISSIONS <permission>...]
                [CONFIGURATIONS <config>...]
                [COMPONENT <component>]
                [EXCLUDE_FROM_ALL])

    The PACKAGE_INFO form generates and installs a Common Package Specification file which describes installed targets such that they can be consumed by another project. Target installations are associated with the export <export-name> using the EXPORT option of the install(TARGETS) signature documented above. Unlike install(EXPORT), this information is not expressed in CMake code, and can be consumed by tools other than CMake. When imported into another CMake project, the imported targets will be prefixed with <package-name>::. By default, the generated file will be called <package-name>[-<appendix-name>].cps. If LOWER_CASE_FILE is given, the package name as it appears on disk (in both the file name and install destination) will be first converted to lower case.

    If DESTINATION is not specified, a platform-specific default is used.

    If APPENDIX is specified, rather than generating a top level package specification, the specified targets will be exported as an appendix to the named package. Appendices may be used to separate less commonly used targets (along with their external dependencies) from the rest of a package. This enables consumers to ignore transitive dependencies for targets that they don't use, and also allows a single logical "package" to be composed of artifacts produced by multiple build trees.

    Appendices are not permitted to change basic package metadata; therefore, none of VERSION, COMPAT_VERSION, VERSION_SCHEMA, DEFAULT_TARGETS or DEFAULT_CONFIGURATIONS may be specified in combination with APPENDIX. Additionally, it is strongly recommended that use of LOWER_CASE_FILE should be consistent between the main package and any appendices.

install(RUNTIME_DEPENDENCY_SET <set-name> [...])
    Added in version 3.21.

    Installs a runtime dependency set:

        install(RUNTIME_DEPENDENCY_SET <set-name>
                [[LIBRARY|RUNTIME|FRAMEWORK]
                 [DESTINATION <dir>]
                 [PERMISSIONS <permission>...]
                 [CONFIGURATIONS <config>...]
                 [COMPONENT <component>]
                 [NAMELINK_COMPONENT <component>]
                 [OPTIONAL] [EXCLUDE_FROM_ALL]
                ] [...]
                [PRE_INCLUDE_REGEXES <regex>...]
                [PRE_EXCLUDE_REGEXES <regex>...]
                [POST_INCLUDE_REGEXES <regex>...]
                [POST_EXCLUDE_REGEXES <regex>...]
                [POST_INCLUDE_FILES <file>...]
                [POST_EXCLUDE_FILES <file>...]
                [DIRECTORIES <dir>...]
                )

    Installs a runtime dependency set previously created by one or more install(TARGETS) or install(IMPORTED_RUNTIME_ARTIFACTS) commands. The dependencies of targets belonging to a runtime dependency set are installed in the RUNTIME destination and component on DLL platforms, and in the LIBRARY destination and component on non-DLL platforms. macOS frameworks are installed in the FRAMEWORK destination and component. Targets built within the build tree will never be installed as runtime dependencies, nor will their own dependencies, unless the targets themselves are installed with install(TARGETS).

    The generated install script calls file(GET_RUNTIME_DEPENDENCIES) on the build-tree files to calculate the runtime dependencies. The build-tree executable files are passed as the EXECUTABLES argument, the build-tree shared libraries as the LIBRARIES argument, and the build-tree modules as the MODULES argument. On macOS, if one of the executables is a MACOSX_BUNDLE, that executable is passed as the BUNDLE_EXECUTABLE argument. At most one such bundle executable may be in the runtime dependency set on macOS. The MACOSX_BUNDLE property has no effect on other platforms. Note that file(GET_RUNTIME_DEPENDENCIES) only supports collecting the runtime dependencies for Windows, Linux and macOS platforms, so install(RUNTIME_DEPENDENCY_SET) has the same limitation.

    The following sub-arguments are forwarded through as the corresponding arguments to file(GET_RUNTIME_DEPENDENCIES) (for those that provide a non-empty list of directories, regular expressions or files). They all support generator expressions.

•   DIRECTORIES <dir>...

•   PRE_INCLUDE_REGEXES <regex>...

•   PRE_EXCLUDE_REGEXES <regex>...

•   POST_INCLUDE_REGEXES <regex>...

•   POST_EXCLUDE_REGEXES <regex>...

•   POST_INCLUDE_FILES <file>...

•   POST_EXCLUDE_FILES <file>...

    NOTE: This command supersedes the install_targets() command and the PRE_INSTALL_SCRIPT and POST_INSTALL_SCRIPT target properties. It also replaces the FILES forms of the install_files() and install_programs() commands. The processing order of these install rules relative to those generated by install_targets(), install_files(), and install_programs() commands is not defined.

  Examples

  Example: Install Targets with Per-Artifact Components

Consider a project that defines targets with different artifact kinds:

    add_executable(myExe myExe.c)
    add_library(myStaticLib STATIC myStaticLib.c)
    target_sources(myStaticLib PUBLIC FILE_SET HEADERS FILES myStaticLib.h)
    add_library(mySharedLib SHARED mySharedLib.c)
    target_sources(mySharedLib PUBLIC FILE_SET HEADERS FILES mySharedLib.h)
    set_property(TARGET mySharedLib PROPERTY SOVERSION 1)

We may call install(TARGETS) with <artifact-kind> arguments to specify different options for each kind of artifact:

    install(TARGETS
              myExe
              mySharedLib
              myStaticLib
            RUNTIME           # Following options apply to runtime artifacts.
              COMPONENT Runtime
            LIBRARY           # Following options apply to library artifacts.
              COMPONENT Runtime
              NAMELINK_COMPONENT Development
            ARCHIVE           # Following options apply to archive artifacts.
              COMPONENT Development
              DESTINATION lib/static
            FILE_SET HEADERS  # Following options apply to file set HEADERS.
              COMPONENT Development
            )

This will:

•   Install myExe to <prefix>/bin, the default RUNTIME artifact destination, as part of the Runtime component.

•   On non-DLL platforms:

•   Install libmySharedLib.so.1 to <prefix>/lib, the default LIBRARY artifact destination, as part of the Runtime component.

•   Install the libmySharedLib.so "namelink" (symbolic link) to <prefix>/lib, the default LIBRARY artifact destination, as part of the Development component.

•   On DLL platforms:

•   Install mySharedLib.dll to <prefix>/bin, the default RUNTIME artifact destination, as part of the Runtime component.

•   Install mySharedLib.lib to <prefix>/lib/static, the specified ARCHIVE artifact destination, as part of the Development component.

•   Install myStaticLib to <prefix>/lib/static, the specified ARCHIVE artifact destination, as part of the Development component.

•   Install mySharedLib.h and myStaticLib.h to <prefix>/include, the default destination for a file set of type HEADERS, as part of the Development component.

  Example: Install Targets to Per-Config Destinations

Each install(TARGETS) call installs a given target output artifact to at most one DESTINATION, but the install rule itself may be filtered by the CONFIGURATIONS option. In order to install to a different destination for each configuration, one call per configuration is needed. For example, the code:

    install(TARGETS myExe
            CONFIGURATIONS Debug
            RUNTIME
              DESTINATION Debug/bin
            )
    install(TARGETS myExe
            CONFIGURATIONS Release
            RUNTIME
              DESTINATION Release/bin
            )

will install myExe to <prefix>/Debug/bin in the Debug configuration, and to <prefix>/Release/bin in the Release configuration.

  Generated Installation Script

NOTE: Use of this feature is not recommended. Please consider using the cmake --install instead.

The install() command generates a file, cmake_install.cmake, inside the build directory, which is used internally by the generated install target and by CPack. You can also invoke this script manually with cmake -P. This script accepts several variables:

COMPONENT
    Set this variable to install only a single CPack component as opposed to all of them. For example, if you only want to install the Development component, run cmake -DCOMPONENT=Development -P cmake_install.cmake.

BUILD_TYPE
    Set this variable to change the build type if you are using a multi-config generator. For example, to install with the Debug configuration, run cmake -DBUILD_TYPE=Debug -P cmake_install.cmake.

DESTDIR
    This is an environment variable rather than a CMake variable. It allows you to change the installation prefix on UNIX systems. See DESTDIR for details.

  link_directories

Add directories in which the linker will look for libraries.

    link_directories([AFTER|BEFORE] directory1 [directory2 ...])

Adds the paths in which the linker should search for libraries. Relative paths given to this command are interpreted as relative to the current source directory, see CMP0015.

The command will apply only to targets created after it is called.

Added in version 3.13: The directories are added to the LINK_DIRECTORIES directory property for the current CMakeLists.txt file, converting relative paths to absolute as needed. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

Added in version 3.13: By default the directories specified are appended onto the current list of directories. This default behavior can be changed by setting CMAKE_LINK_DIRECTORIES_BEFORE to ON. By using AFTER or BEFORE explicitly, you can select between appending and prepending, independent of the default.

Added in version 3.13: Arguments to link_directories may use "generator expressions" with the syntax "$<...>". See the cmake-generator-expressions(7) manual for available expressions.

NOTE: This command is rarely necessary and should be avoided where there are other choices. Prefer to pass full absolute paths to libraries where possible, since this ensures the correct library will always be linked. The find_library() command provides the full path, which can generally be used directly in calls to target_link_libraries(). Situations where a library search path may be needed include:

•   Project generators like Xcode where the user can switch target architecture at build time, but a full path to a library cannot be used because it only provides one architecture (i.e. it is not a universal binary).

•   Libraries may themselves have other private library dependencies that expect to be found via RPATH mechanisms, but some linkers are not able to fully decode those paths (e.g. due to the presence of things like $ORIGIN).

    If a library search path must be provided, prefer to localize the effect where possible by using the target_link_directories() command rather than link_directories(). The target-specific command can also control how the search directories propagate to other dependent targets.

  See Also

•   target_link_directories()

•   target_link_libraries()

  link_libraries

Link libraries to all targets added later.

    link_libraries([item1 [item2 [...]]]
                   [[debug|optimized|general] <item>] ...)

Specify libraries or flags to use when linking any targets created later in the current directory or below by commands such as add_executable() or add_library(). See the target_link_libraries() command for meaning of arguments.

NOTE: The target_link_libraries() command should be preferred whenever possible. Library dependencies are chained automatically, so directory-wide specification of link libraries is rarely needed.

  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
    Added 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: <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.

    Changed in version 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 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 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.

    Added 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>
    Added 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.

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

HOMEPAGE_URL <url-string>
    Added 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. Added in version 3.8: Added CSharp and CUDA support.

    Added in version 3.15: Added Swift support.

    Added in version 3.16: Added OBJC and OBJCXX support.

    Added in version 3.18: Added ISPC support.

    Added in version 3.21: Added HIP support.

    Added 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:

•   Added 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.

•   Added 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.

•   Added 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.

•   Added 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.

  remove_definitions

Remove -D define flags added by add_definitions().

    remove_definitions(-DFOO -DBAR ...)

Removes flags (added by add_definitions()) from the compiler command line for sources in the current directory and below.

  set_source_files_properties

Source files can have properties that affect how they are built.

    set_source_files_properties(<files> ...
                                [DIRECTORY <dirs> ...]
                                [TARGET_DIRECTORY <targets> ...]
                                PROPERTIES <prop1> <value1>
                                [<prop2> <value2>] ...)

Sets properties associated with source files using a key/value paired list.

Added in version 3.18: By default, source file properties are only visible to targets added in the same directory (CMakeLists.txt). Visibility can be set in other directory scopes using one or both of the following options:

DIRECTORY <dirs>...
    The source file properties will be set in each of the <dirs> directories' scopes. CMake must already know about each of these source directories, either by having added them through a call to add_subdirectory() or it being the top level source directory. Relative paths are treated as relative to the current source directory.

TARGET_DIRECTORY <targets>...
    The source file properties will be set in each of the directory scopes where any of the specified <targets> were created (the <targets> must therefore already exist).

    Use get_source_file_property() to get property values. See also the set_property(SOURCE) command.

    NOTE: The GENERATED source file property may be globally visible. See its documentation for details.

  See Also

•   define_property()

•   get_source_file_property()

•   Properties on Source Files for the list of properties known to CMake

  set_target_properties

Targets can have properties that affect how they are built.

    set_target_properties(<targets> ...
                          PROPERTIES <prop1> <value1>
                          [<prop2> <value2>] ...)

Sets properties on targets. The syntax for the command is to list all the targets you want to change, and then provide the values you want to set next. You can use any prop value pair you want and extract it later with the get_property() or get_target_property() command.

Alias Targets do not support setting target properties.

  See Also

•   define_property()

•   get_target_property()

•   the more general set_property() command

•   Properties on Targets for the list of properties known to CMake

  set_tests_properties

Set a property of the tests.

    set_tests_properties(<tests>...
                         [DIRECTORY <dir>]
                         PROPERTIES <prop1> <value1>
                         [<prop2> <value2>]...)

Sets a property for the tests. If the test is not found, CMake will report an error.

Test property values may be specified using generator expressions for tests created by the add_test(NAME) signature.

Added in version 3.28: Visibility can be set in other directory scopes using the following option:

DIRECTORY <dir>
    The test properties will be set in the <dir> directory's scope. CMake must already know about this directory, either by having added it through a call to add_subdirectory() or it being the top level source directory. Relative paths are treated as relative to the current source directory. <dir> may reference a binary directory.

  See Also

•   add_test()

•   define_property()

•   the more general set_property() command

•   Properties on Tests for the list of properties known to CMake

  source_group

Define a grouping for source files in IDE project generation. There are two different signatures to create source groups.

    source_group(<name> [FILES <src>...] [REGULAR_EXPRESSION <regex>])
    source_group(TREE <root> [PREFIX <prefix>] [FILES <src>...])

Defines a group into which sources will be placed in project files. This is intended to set up file tabs in Visual Studio. The group is scoped in the directory where the command is called, and applies to sources in targets created in that directory.

The options are:

TREE
    Added in version 3.8.

    CMake will automatically detect, from <src> files paths, source groups it needs to create, to keep structure of source groups analogically to the actual files and directories structure in the project. Paths of <src> files will be cut to be relative to <root>. The command fails if the paths within src do not start with root.

PREFIX
    Added in version 3.8.

    Source group and files located directly in <root> path, will be placed in <prefix> source groups.

FILES
    Any source file specified explicitly will be placed in group <name>. Relative paths are interpreted with respect to the current source directory.

REGULAR_EXPRESSION
    Any source file whose name matches the regular expression will be placed in group <name>.

    If a source file matches multiple groups, the last group that explicitly lists the file with FILES will be favored, if any. If no group explicitly lists the file, the last group whose regular expression matches the file will be favored.

    The <name> of the group and <prefix> argument may contain forward slashes or backslashes to specify subgroups. Backslashes need to be escaped appropriately:

        source_group(base/subdir ...)
        source_group(outer\\inner ...)
        source_group(TREE <root> PREFIX sources\\inc ...)

    Added in version 3.18: Allow using forward slashes (/) to specify subgroups.

    For backwards compatibility, the short-hand signature

        source_group(<name> <regex>)

    is equivalent to

        source_group(<name> REGULAR_EXPRESSION <regex>)

  target_compile_definitions

Add compile definitions to a target.

    target_compile_definitions(<target>
      <INTERFACE|PUBLIC|PRIVATE> [items1...]
      [<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])

Specifies compile definitions to use when compiling a given <target>. The named <target> must have been created by a command such as add_executable() or add_library() and must not be an ALIAS target.

The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the following arguments. PRIVATE and PUBLIC items will populate the COMPILE_DEFINITIONS property of <target>. PUBLIC and INTERFACE items will populate the INTERFACE_COMPILE_DEFINITIONS property of <target>. The following arguments specify compile definitions. Repeated calls for the same <target> append items in the order called.

Added in version 3.11: Allow setting INTERFACE items on IMPORTED targets.

Arguments to target_compile_definitions may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

Any leading -D on an item will be removed. Empty items are ignored. For example, the following are all equivalent:

    target_compile_definitions(foo PUBLIC FOO)
    target_compile_definitions(foo PUBLIC -DFOO)  # -D removed
    target_compile_definitions(foo PUBLIC "" FOO) # "" ignored
    target_compile_definitions(foo PUBLIC -D FOO) # -D becomes "", then ignored

Definitions may optionally have values:

    target_compile_definitions(foo PUBLIC FOO=1)

Note that many compilers treat -DFOO as equivalent to -DFOO=1, but other tools may not recognize this in all circumstances (e.g. IntelliSense).

  See Also

•   add_compile_definitions()

•   target_compile_features()

•   target_compile_options()

•   target_include_directories()

•   target_link_libraries()

•   target_link_directories()

•   target_link_options()

•   target_precompile_headers()

•   target_sources()

  target_compile_features

Added in version 3.1.

Add expected compiler features to a target.

    target_compile_features(<target> <PRIVATE|PUBLIC|INTERFACE> <feature> [...])

Specifies compiler features required when compiling a given target. If the feature is not listed in the CMAKE_C_COMPILE_FEATURES, CMAKE_CUDA_COMPILE_FEATURES, or CMAKE_CXX_COMPILE_FEATURES variables, then an error will be reported by CMake. If the use of the feature requires an additional compiler flag, such as -std=gnu++11, the flag will be added automatically.

The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the features. PRIVATE and PUBLIC items will populate the COMPILE_FEATURES property of <target>. PUBLIC and INTERFACE items will populate the INTERFACE_COMPILE_FEATURES property of <target>. Repeated calls for the same <target> append items.

Added in version 3.11: Allow setting INTERFACE items on IMPORTED targets.

The named <target> must have been created by a command such as add_executable() or add_library() and must not be an ALIAS target. for more on defining buildsystem properties.

Arguments to target_compile_features may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-compile-features(7) manual for information on compile features and a list of supported compilers.

  See Also

•   target_compile_definitions()

•   target_compile_options()

•   target_include_directories()

•   target_link_libraries()

•   target_link_directories()

•   target_link_options()

•   target_precompile_headers()

•   target_sources()

  target_compile_options

Add compile options to a target.

    target_compile_options(<target> [BEFORE]
      <INTERFACE|PUBLIC|PRIVATE> [items1...]
      [<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])

Adds options to the COMPILE_OPTIONS or INTERFACE_COMPILE_OPTIONS target properties. These options are used when compiling the given <target>, which must have been created by a command such as add_executable() or add_library() and must not be an ALIAS target.

NOTE: These options are not used when linking the target. See the target_link_options() command for that.

  Arguments

If BEFORE is specified, the content will be prepended to the property instead of being appended. See policy CMP0101 which affects whether BEFORE will be ignored in certain cases.

The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the following arguments. PRIVATE and PUBLIC items will populate the COMPILE_OPTIONS property of <target>. PUBLIC and INTERFACE items will populate the INTERFACE_COMPILE_OPTIONS property of <target>. The following arguments specify compile options. Repeated calls for the same <target> append items in the order called.

Added in version 3.11: Allow setting INTERFACE items on IMPORTED targets.

Arguments to target_compile_options may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

  Option De-duplication

The final set of options used for a target is constructed by accumulating options from the current target and the usage requirements of its dependencies. The set of options is de-duplicated to avoid repetition.

Added in version 3.12: While beneficial for individual options, the de-duplication step can break up option groups. For example, -option A -option B becomes -option A B. One may specify a group of options using shell-like quoting along with a SHELL: prefix. The SHELL: prefix is dropped, and the rest of the option string is parsed using the separate_arguments() UNIX_COMMAND mode. For example, "SHELL:-option A" "SHELL:-option B" becomes -option A -option B.

  See Also

•   This command can be used to add any options. However, for adding preprocessor definitions and include directories it is recommended to use the more specific commands target_compile_definitions() and target_include_directories().

•   For directory-wide settings, there is the command add_compile_options().

•   For file-specific settings, there is the source file property COMPILE_OPTIONS.

•   This command adds compile options for all languages in a target. Use the COMPILE_LANGUAGE generator expression to specify per-language compile options.

•   target_compile_features()

•   target_link_libraries()

•   target_link_directories()

•   target_link_options()

•   target_precompile_headers()

•   target_sources()

•   CMAKE_<LANG>_FLAGS and CMAKE_<LANG>_FLAGS_<CONFIG> add language-wide flags passed to all invocations of the compiler. This includes invocations that drive compiling and those that drive linking.

  target_include_directories

Add include directories to a target.

    target_include_directories(<target> [SYSTEM] [AFTER|BEFORE]
      <INTERFACE|PUBLIC|PRIVATE> [items1...]
      [<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])

Specifies include directories to use when compiling a given target. The named <target> must have been created by a command such as add_executable() or add_library() and must not be an ALIAS target.

By using AFTER or BEFORE explicitly, you can select between appending and prepending, independent of the default.

The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the following arguments. PRIVATE and PUBLIC items will populate the INCLUDE_DIRECTORIES property of <target>. PUBLIC and INTERFACE items will populate the INTERFACE_INCLUDE_DIRECTORIES property of <target>. The following arguments specify include directories.

Added in version 3.11: Allow setting INTERFACE items on IMPORTED targets.

Repeated calls for the same <target> append items in the order called.

If SYSTEM is specified, the compiler will be told the directories are meant as system include directories on some platforms. This may have effects such as suppressing warnings or skipping the contained headers in dependency calculations (see compiler documentation). Additionally, system include directories are searched after normal include directories regardless of the order specified.

If SYSTEM is used together with PUBLIC or INTERFACE, the INTERFACE_SYSTEM_INCLUDE_DIRECTORIES target property will be populated with the specified directories.

Arguments to target_include_directories may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

Specified include directories may be absolute paths or relative paths. A relative path will be interpreted as relative to the current source directory (i.e. CMAKE_CURRENT_SOURCE_DIR) and converted to an absolute path before storing it in the associated target property. If the path starts with a generator expression, it will always be assumed to be an absolute path (with one exception noted below) and will be used unmodified.

Include directories usage requirements commonly differ between the build-tree and the install-tree. The BUILD_INTERFACE and INSTALL_INTERFACE generator expressions can be used to describe separate usage requirements based on the usage location. Relative paths are allowed within the INSTALL_INTERFACE expression and are interpreted as relative to the installation prefix. Relative paths should not be used in BUILD_INTERFACE expressions because they will not be converted to absolute. For example:

    target_include_directories(mylib PUBLIC
      $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include/mylib>
      $<INSTALL_INTERFACE:include/mylib>  # <prefix>/include/mylib
    )

  Creating Relocatable Packages

Note that it is not advisable to populate the INSTALL_INTERFACE of the INTERFACE_INCLUDE_DIRECTORIES of a target with absolute paths to the include directories of dependencies. That would hard-code into installed packages the include directory paths for dependencies as found on the machine the package was made on.

The INSTALL_INTERFACE of the INTERFACE_INCLUDE_DIRECTORIES is only suitable for specifying the required include directories for headers provided with the target itself, not those provided by the transitive dependencies listed in its INTERFACE_LINK_LIBRARIES target property. Those dependencies should themselves be targets that specify their own header locations in INTERFACE_INCLUDE_DIRECTORIES.

See the Creating Relocatable Packages section of the cmake-packages(7) manual for discussion of additional care that must be taken when specifying usage requirements while creating packages for redistribution.

  See Also

•   include_directories()

•   target_compile_definitions()

•   target_compile_features()

•   target_compile_options()

•   target_link_libraries()

•   target_link_directories()

•   target_link_options()

•   target_precompile_headers()

•   target_sources()

  target_link_directories

Added in version 3.13.

Add link directories to a target.

    target_link_directories(<target> [BEFORE]
      <INTERFACE|PUBLIC|PRIVATE> [items1...]
      [<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])

Specifies the paths in which the linker should search for libraries when linking a given target. Each item can be an absolute or relative path, with the latter being interpreted as relative to the current source directory. These items will be added to the link command.

The named <target> must have been created by a command such as add_executable() or add_library() and must not be an ALIAS target.

The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the items that follow them. PRIVATE and PUBLIC items will populate the LINK_DIRECTORIES property of <target>. PUBLIC and INTERFACE items will populate the INTERFACE_LINK_DIRECTORIES property of <target> (IMPORTED targets only support INTERFACE items). Each item specifies a link directory and will be converted to an absolute path if necessary before adding it to the relevant property. Repeated calls for the same <target> append items in the order called.

If BEFORE is specified, the content will be prepended to the relevant property instead of being appended.

Arguments to target_link_directories may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

NOTE: This command is rarely necessary and should be avoided where there are other choices. Prefer to pass full absolute paths to libraries where possible, since this ensures the correct library will always be linked. The find_library() command provides the full path, which can generally be used directly in calls to target_link_libraries(). Situations where a library search path may be needed include:

•   Project generators like Xcode where the user can switch target architecture at build time, but a full path to a library cannot be used because it only provides one architecture (i.e. it is not a universal binary).

•   Libraries may themselves have other private library dependencies that expect to be found via RPATH mechanisms, but some linkers are not able to fully decode those paths (e.g. due to the presence of things like $ORIGIN).

  See Also

•   link_directories()

•   target_compile_definitions()

•   target_compile_features()

•   target_compile_options()

•   target_include_directories()

•   target_link_libraries()

•   target_link_options()

•   target_precompile_headers()

•   target_sources()

  target_link_libraries

Specify libraries or flags to use when linking a given target and/or its dependents. Usage requirements from linked library targets will be propagated. Usage requirements of a target's dependencies affect compilation of its own sources.

  Overview

This command has several signatures as detailed in subsections below. All of them have the general form

    target_link_libraries(<target> ... <item>... ...)

The named <target> must have been created by a command such as add_executable() or add_library() and must not be an ALIAS target. If policy CMP0079 is not set to NEW then the target must have been created in the current directory. Repeated calls for the same <target> append items in the order called.

Added in version 3.13: The <target> doesn't have to be defined in the same directory as the target_link_libraries call.

Each <item> may be:

•   A library target name: The generated link line will have the full path to the linkable library file associated with the target. The buildsystem will have a dependency to re-link <target> if the library file changes.

    The named target must be created by add_library() within the project or as an IMPORTED library. If it is created within the project an ordering dependency will automatically be added in the build system to make sure the named library target is up-to-date before the <target> links.

    If an imported library has the IMPORTED_NO_SONAME target property set, CMake may ask the linker to search for the library instead of using the full path (e.g. /usr/lib/libfoo.so becomes -lfoo).

    The full path to the target's artifact will be quoted/escaped for the shell automatically.

•   A full path to a library file: The generated link line will normally preserve the full path to the file. The buildsystem will have a dependency to re-link <target> if the library file changes.

    There are some cases where CMake may ask the linker to search for the library (e.g. /usr/lib/libfoo.so becomes -lfoo), such as when a shared library is detected to have no SONAME field. In CMake versions prior to 4.0, see policy CMP0060 for discussion of another case.

    If the library file is in a macOS framework, the Headers directory of the framework will also be processed as a usage requirement. This has the same effect as passing the framework directory as an include directory.

    Added in version 3.28: The library file may point to a .xcframework folder on Apple platforms. If it does, the target will get the selected library's Headers directory as a usage requirement.

    Added in version 3.8: On Visual Studio Generators for VS 2010 and above, library files ending in .targets will be treated as MSBuild targets files and imported into generated project files. This is not supported by other generators.

    The full path to the library file will be quoted/escaped for the shell automatically.

•   A plain library name: The generated link line will ask the linker to search for the library (e.g. foo becomes -lfoo or foo.lib).

    The library name/flag is treated as a command-line string fragment and will be used with no extra quoting or escaping.

•   A link flag: Item names starting with -, but not -l or -framework, are treated as linker flags. Note that such flags will be treated like any other library link item for purposes of transitive dependencies, so they are generally safe to specify only as private link items that will not propagate to dependents.

    Link flags specified here are inserted into the link command in the same place as the link libraries. This might not be correct, depending on the linker. Use the LINK_OPTIONS target property or target_link_options() command to add link flags explicitly. The flags will then be placed at the toolchain-defined flag position in the link command.

    Added in version 3.13: LINK_OPTIONS target property and target_link_options() command. For earlier versions of CMake, use LINK_FLAGS property instead.

    The link flag is treated as a command-line string fragment and will be used with no extra quoting or escaping.

•   A generator expression: A $<...> generator expression may evaluate to any of the above items or to a semicolon-separated list of them. If the ... contains any ; characters, e.g. after evaluation of a ${list} variable, be sure to use an explicitly quoted argument "$<...>" so that this command receives it as a single <item>.

    Additionally, a generator expression may be used as a fragment of any of the above items, e.g. foo$<1:_d>.

•   A debug, optimized, or general keyword immediately followed by another <item>. The item following such a keyword will be used only for the corresponding build configuration. The debug keyword corresponds to the Debug configuration (or to configurations named in the DEBUG_CONFIGURATIONS global property if it is set). The optimized keyword corresponds to all other configurations. The general keyword corresponds to all configurations, and is purely optional. Higher granularity may be achieved for per-configuration rules by creating and linking to IMPORTED library targets. These keywords are interpreted immediately by this command and therefore have no special meaning when produced by a generator expression.

    Items containing ::, such as Foo::Bar, are assumed to be IMPORTED or ALIAS library target names and will cause an error if no such target exists. See policy CMP0028.

    See the CMAKE_LINK_LIBRARIES_STRATEGY variable and corresponding LINK_LIBRARIES_STRATEGY target property for details on how CMake orders direct link dependencies on linker command lines.

    See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

  Handling Compiler Driver Differences

Added in version 4.0.

To pass options to the linker tool, each compiler driver has its own syntax. The LINKER: prefix and , separator can be used to specify, in a portable way, options to pass to the linker tool. LINKER: is replaced by the appropriate driver option and , by the appropriate driver separator. The driver prefix and driver separator are given by the values of the CMAKE_<LANG>_LINKER_WRAPPER_FLAG and CMAKE_<LANG>_LINKER_WRAPPER_FLAG_SEP variables.

For example, "LINKER:-z,defs" becomes -Xlinker -z -Xlinker defs for Clang and -Wl,-z,defs for GNU GCC.

The LINKER: prefix supports, as an alternative syntax, specification of arguments using the SHELL: prefix and space as separator. The previous example then becomes "LINKER:SHELL:-z defs".

NOTE: Specifying the SHELL: prefix anywhere other than at the beginning of the LINKER: prefix is not supported.

  Libraries for a Target and/or its Dependents

    target_link_libraries(<target>
                          <PRIVATE|PUBLIC|INTERFACE> <item>...
                         [<PRIVATE|PUBLIC|INTERFACE> <item>...]...)

The PUBLIC, PRIVATE and INTERFACE scope keywords can be used to specify both the link dependencies and the link interface in one command.

Libraries and targets following PUBLIC are linked to, and are made part of the link interface. Libraries and targets following PRIVATE are linked to, but are not made part of the link interface. Libraries following INTERFACE are appended to the link interface and are not used for linking <target>.

  Libraries for both a Target and its Dependents

    target_link_libraries(<target> <item>...)

Library dependencies are transitive by default with this signature. When this target is linked into another target then the libraries linked to this target will appear on the link line for the other target too. This transitive "link interface" is stored in the INTERFACE_LINK_LIBRARIES target property and may be overridden by setting the property directly.

In CMake versions prior to 4.0, if CMP0022 is not set to NEW, transitive linking is built in but may be overridden by the LINK_INTERFACE_LIBRARIES property. Calls to other signatures of this command may set the property making any libraries linked exclusively by this signature private.

  Libraries for a Target and/or its Dependents (Legacy)

This signature is for compatibility only. Prefer the PUBLIC or PRIVATE keywords instead.

    target_link_libraries(<target>
                          <LINK_PRIVATE|LINK_PUBLIC> <lib>...
                         [<LINK_PRIVATE|LINK_PUBLIC> <lib>...]...)

The LINK_PUBLIC and LINK_PRIVATE modes can be used to specify both the link dependencies and the link interface in one command.

Libraries and targets following LINK_PUBLIC are linked to, and are made part of the INTERFACE_LINK_LIBRARIES.

In CMake versions prior to 4.0, if policy CMP0022 is not NEW, they are also made part of the LINK_INTERFACE_LIBRARIES. Libraries and targets following LINK_PRIVATE are linked to, but are not made part of the INTERFACE_LINK_LIBRARIES (or LINK_INTERFACE_LIBRARIES).

  Libraries for Dependents Only (Legacy)

This signature is for compatibility only. Prefer the INTERFACE mode instead.

    target_link_libraries(<target> LINK_INTERFACE_LIBRARIES <item>...)

The LINK_INTERFACE_LIBRARIES mode appends the libraries to the INTERFACE_LINK_LIBRARIES target property instead of using them for linking.

In CMake versions prior to 4.0, if policy CMP0022 is not NEW, then this mode also appends libraries to the LINK_INTERFACE_LIBRARIES and its per-configuration equivalent.

  Linking Object Libraries

Added in version 3.12.

Object Libraries may be used as the <target> (first) argument of target_link_libraries to specify dependencies of their sources on other libraries. For example, the code

    add_library(A SHARED a.c)
    target_compile_definitions(A PUBLIC A)
    add_library(obj OBJECT obj.c)
    target_compile_definitions(obj PUBLIC OBJ)
    target_link_libraries(obj PUBLIC A)

compiles obj.c with -DA -DOBJ and establishes usage requirements for obj that propagate to its dependents.

Normal libraries and executables may link to Object Libraries to get their objects and usage requirements. Continuing the above example, the code

    add_library(B SHARED b.c)
    target_link_libraries(B PUBLIC obj)

compiles b.c with -DA -DOBJ, creates shared library B with object files from b.c and obj.c, and links B to A. Furthermore, the code

    add_executable(main main.c)
    target_link_libraries(main B)

compiles main.c with -DA -DOBJ and links executable main to B and A. The object library's usage requirements are propagated transitively through B, but its object files are not.

Object Libraries may "link" to other object libraries to get usage requirements, but since they do not have a link step nothing is done with their object files. Continuing from the above example, the code:

    add_library(obj2 OBJECT obj2.c)
    target_link_libraries(obj2 PUBLIC obj)
    add_executable(main2 main2.c)
    target_link_libraries(main2 obj2)

compiles obj2.c with -DA -DOBJ, creates executable main2 with object files from main2.c and obj2.c, and links main2 to A.

In other words, when Object Libraries appear in a target's INTERFACE_LINK_LIBRARIES property they will be treated as Interface Libraries, but when they appear in a target's LINK_LIBRARIES property their object files will be included in the link too.

  Linking Object Libraries via $<TARGET_OBJECTS>

Added in version 3.21.

The object files associated with an object library may be referenced by the $<TARGET_OBJECTS> generator expression. Such object files are placed on the link line before all libraries, regardless of their relative order. Additionally, an ordering dependency will be added to the build system to make sure the object library is up-to-date before the dependent target links. For example, the code

    add_library(obj3 OBJECT obj3.c)
    target_compile_definitions(obj3 PUBLIC OBJ3)
    add_executable(main3 main3.c)
    target_link_libraries(main3 PRIVATE a3 $<TARGET_OBJECTS:obj3> b3)

links executable main3 with object files from main3.c and obj3.c followed by the a3 and b3 libraries. main3.c is not compiled with usage requirements from obj3, such as -DOBJ3.

This approach can be used to achieve transitive inclusion of object files in link lines as usage requirements. Continuing the above example, the code

    add_library(iface_obj3 INTERFACE)
    target_link_libraries(iface_obj3 INTERFACE obj3 $<TARGET_OBJECTS:obj3>)

creates an interface library iface_obj3 that forwards the obj3 usage requirements and adds the obj3 object files to dependents' link lines. The code

    add_executable(use_obj3 use_obj3.c)
    target_link_libraries(use_obj3 PRIVATE iface_obj3)

compiles use_obj3.c with -DOBJ3 and links executable use_obj3 with object files from use_obj3.c and obj3.c.

This also works transitively through a static library. Since a static library does not link, it does not consume the object files from object libraries referenced this way. Instead, the object files become transitive link dependencies of the static library. Continuing the above example, the code

    add_library(static3 STATIC static3.c)
    target_link_libraries(static3 PRIVATE iface_obj3)
    add_executable(use_static3 use_static3.c)
    target_link_libraries(use_static3 PRIVATE static3)

compiles static3.c with -DOBJ3 and creates libstatic3.a using only its own object file. use_static3.c is compiled without -DOBJ3 because the usage requirement is not transitive through the private dependency of static3. However, the link dependencies of static3 are propagated, including the iface_obj3 reference to $<TARGET_OBJECTS:obj3>. The use_static3 executable is created with object files from use_static3.c and obj3.c, and linked to library libstatic3.a.

When using this approach, it is the project's responsibility to avoid linking multiple dependent binaries to iface_obj3, because they will all get the obj3 object files on their link lines.

NOTE: Referencing $<TARGET_OBJECTS> in target_link_libraries calls worked in versions of CMake prior to 3.21 for some cases, but was not fully supported:

•   It did not place the object files before libraries on link lines.

•   It did not add an ordering dependency on the object library.

•   It did not work in Xcode with multiple architectures.

  Cyclic Dependencies of Static Libraries

The library dependency graph is normally acyclic (a DAG), but in the case of mutually-dependent STATIC libraries CMake allows the graph to contain cycles (strongly connected components). When another target links to one of the libraries, CMake repeats the entire connected component. For example, the code

    add_library(A STATIC a.c)
    add_library(B STATIC b.c)
    target_link_libraries(A B)
    target_link_libraries(B A)
    add_executable(main main.c)
    target_link_libraries(main A)

links main to A B A B. While one repetition is usually sufficient, pathological object file and symbol arrangements can require more. One may handle such cases by using the LINK_INTERFACE_MULTIPLICITY target property or by manually repeating the component in the last target_link_libraries call. However, if two archives are really so interdependent they should probably be combined into a single archive, perhaps by using Object Libraries.

  Creating Relocatable Packages

Note that it is not advisable to populate the INTERFACE_LINK_LIBRARIES of a target with absolute paths to dependencies. That would hard-code into installed packages the library file paths for dependencies as found on the machine the package was made on.

See the Creating Relocatable Packages section of the cmake-packages(7) manual for discussion of additional care that must be taken when specifying usage requirements while creating packages for redistribution.

  See Also

•   target_compile_definitions()

•   target_compile_features()

•   target_compile_options()

•   target_include_directories()

•   target_link_directories()

•   target_link_options()

•   target_precompile_headers()

•   target_sources()

  target_link_options

Added in version 3.13.

Add options to the link step for an executable, shared library or module library target.

    target_link_options(<target> [BEFORE]
      <INTERFACE|PUBLIC|PRIVATE> [items1...]
      [<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])

The named <target> must have been created by a command such as add_executable() or add_library() and must not be an ALIAS target.

This command can be used to add any link options, but alternative commands exist to add libraries (target_link_libraries() or link_libraries()). See documentation of the directory and target LINK_OPTIONS properties.

NOTE: This command cannot be used to add options for static library targets, since they do not use a linker. To add archiver or MSVC librarian flags, see the STATIC_LIBRARY_OPTIONS target property.

If BEFORE is specified, the content will be prepended to the property instead of being appended.

The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the following arguments. PRIVATE and PUBLIC items will populate the LINK_OPTIONS property of <target>. PUBLIC and INTERFACE items will populate the INTERFACE_LINK_OPTIONS property of <target>. The following arguments specify link options. Repeated calls for the same <target> append items in the order called.

NOTE: IMPORTED targets only support INTERFACE items.

Arguments to target_link_options may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

  Host And Device Specific Link Options

Added in version 3.18: When a device link step is involved, which is controlled by CUDA_SEPARABLE_COMPILATION and CUDA_RESOLVE_DEVICE_SYMBOLS properties and policy CMP0105, the raw options will be delivered to the host and device link steps (wrapped in -Xcompiler or equivalent for device link). Options wrapped with $<DEVICE_LINK:...> generator expression will be used only for the device link step. Options wrapped with $<HOST_LINK:...> generator expression will be used only for the host link step.

  Option De-duplication

The final set of options used for a target is constructed by accumulating options from the current target and the usage requirements of its dependencies. The set of options is de-duplicated to avoid repetition.

Added in version 3.12: While beneficial for individual options, the de-duplication step can break up option groups. For example, -option A -option B becomes -option A B. One may specify a group of options using shell-like quoting along with a SHELL: prefix. The SHELL: prefix is dropped, and the rest of the option string is parsed using the separate_arguments() UNIX_COMMAND mode. For example, "SHELL:-option A" "SHELL:-option B" becomes -option A -option B.

  Handling Compiler Driver Differences

To pass options to the linker tool, each compiler driver has its own syntax. The LINKER: prefix and , separator can be used to specify, in a portable way, options to pass to the linker tool. LINKER: is replaced by the appropriate driver option and , by the appropriate driver separator. The driver prefix and driver separator are given by the values of the CMAKE_<LANG>_LINKER_WRAPPER_FLAG and CMAKE_<LANG>_LINKER_WRAPPER_FLAG_SEP variables.

For example, "LINKER:-z,defs" becomes -Xlinker -z -Xlinker defs for Clang and -Wl,-z,defs for GNU GCC.

The LINKER: prefix can be specified as part of a SHELL: prefix expression.

The LINKER: prefix supports, as an alternative syntax, specification of arguments using the SHELL: prefix and space as separator. The previous example then becomes "LINKER:SHELL:-z defs".

NOTE: Specifying the SHELL: prefix anywhere other than at the beginning of the LINKER: prefix is not supported.

  See Also

•   target_compile_definitions()

•   target_compile_features()

•   target_compile_options()

•   target_include_directories()

•   target_link_libraries()

•   target_link_directories()

•   target_precompile_headers()

•   target_sources()

•   CMAKE_<LANG>_FLAGS and CMAKE_<LANG>_FLAGS_<CONFIG> add language-wide flags passed to all invocations of the compiler. This includes invocations that drive compiling and those that drive linking.

  target_precompile_headers

Added in version 3.16.

Add a list of header files to precompile.

Precompiling header files can speed up compilation by creating a partially processed version of some header files, and then using that version during compilations rather than repeatedly parsing the original headers.

  Main Form

    target_precompile_headers(<target>
      <INTERFACE|PUBLIC|PRIVATE> [header1...]
      [<INTERFACE|PUBLIC|PRIVATE> [header2...] ...])

The command adds header files to the PRECOMPILE_HEADERS and/or INTERFACE_PRECOMPILE_HEADERS target properties of <target>. The named <target> must have been created by a command such as add_executable() or add_library() and must not be an ALIAS target.

The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the following arguments. PRIVATE and PUBLIC items will populate the PRECOMPILE_HEADERS property of <target>. PUBLIC and INTERFACE items will populate the INTERFACE_PRECOMPILE_HEADERS property of <target> (IMPORTED targets only support INTERFACE items). Repeated calls for the same <target> will append items in the order called.

Projects should generally avoid using PUBLIC or INTERFACE for targets that will be exported, or they should at least use the $<BUILD_INTERFACE:...> generator expression to prevent precompile headers from appearing in an installed exported target. Consumers of a target should typically be in control of what precompile headers they use, not have precompile headers forced on them by the targets being consumed (since precompile headers are not typically usage requirements). A notable exception to this is where an interface library is created to define a commonly used set of precompile headers in one place and then other targets link to that interface library privately. In this case, the interface library exists specifically to propagate the precompile headers to its consumers and the consumer is effectively still in control, since it decides whether to link to the interface library or not.

The list of header files is used to generate a header file named cmake_pch.h|xx which is used to generate the precompiled header file (.pch, .gch, .pchi) artifact. The cmake_pch.h|xx header file will be force included (-include for GCC, /FI for MSVC) to all source files, so sources do not need to have #include "pch.h".

Header file names specified with angle brackets (e.g. <unordered_map>) or explicit double quotes (escaped for the cmake-language(7), e.g. [["other_header.h"]]) will be treated as is, and include directories must be available for the compiler to find them. Other header file names (e.g. project_header.h) are interpreted as being relative to the current source directory (e.g. CMAKE_CURRENT_SOURCE_DIR) and will be included by absolute path. For example:

    target_precompile_headers(myTarget
      PUBLIC
        project_header.h
      PRIVATE
        [["other_header.h"]]
        <unordered_map>
    )
for more on defining buildsystem properties.

Arguments to target_precompile_headers may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. The $<COMPILE_LANGUAGE:...> generator expression is particularly useful for specifying a language-specific header to precompile for only one language (e.g. CXX and not C). In this case, header file names that are not explicitly in double quotes or angle brackets must be specified by absolute path. Also, when specifying angle brackets inside a generator expression, be sure to encode the closing > as $<ANGLE-R>. For example:

    target_precompile_headers(mylib PRIVATE
      "$<$<COMPILE_LANGUAGE:CXX>:${CMAKE_CURRENT_SOURCE_DIR}/cxx_only.h>"
      "$<$<COMPILE_LANGUAGE:C>:<stddef.h$<ANGLE-R>>"
      "$<$<COMPILE_LANGUAGE:CXX>:<cstddef$<ANGLE-R>>"
    )

  Reusing Precompile Headers

The command also supports a second signature which can be used to specify that one target reuses a precompiled header file artifact from another target instead of generating its own:

    target_precompile_headers(<target> REUSE_FROM <other_target>)

This form sets the PRECOMPILE_HEADERS_REUSE_FROM property to <other_target> and adds a dependency such that <target> will depend on <other_target>. CMake will halt with an error if the PRECOMPILE_HEADERS property of <target> is already set when the REUSE_FROM form is used.

NOTE: The REUSE_FROM form requires the same set of compiler options, compiler flags and compiler definitions for both <target> and <other_target>. Some compilers (e.g. GCC) may issue a warning if the precompiled header file cannot be used (-Winvalid-pch).

  See Also

•   To disable precompile headers for specific targets, see the DISABLE_PRECOMPILE_HEADERS target property.

•   To prevent precompile headers from being used when compiling a specific source file, see the SKIP_PRECOMPILE_HEADERS source file property.

•   target_compile_definitions()

•   target_compile_features()

•   target_compile_options()

•   target_include_directories()

•   target_link_libraries()

•   target_link_directories()

•   target_link_options()

•   target_sources()

  target_sources

Added in version 3.1.

Add sources to a target.

    target_sources(<target>
      <INTERFACE|PUBLIC|PRIVATE> [items1...]
      [<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])

Specifies sources to use when building a target and/or its dependents. The named <target> must have been created by a command such as add_executable() or add_library() or add_custom_target() and must not be an ALIAS target. The <items> may use generator expressions.

Added in version 3.20: <target> can be a custom target.

The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the source file paths (<items>) that follow them. PRIVATE and PUBLIC items will populate the SOURCES property of <target>, which are used when building the target itself. PUBLIC and INTERFACE items will populate the INTERFACE_SOURCES property of <target>, which are used when building dependents. A target created by add_custom_target() can only have PRIVATE scope.

Repeated calls for the same <target> append items in the order called.

Added in version 3.3: Allow exporting targets with INTERFACE_SOURCES.

Added in version 3.11: Allow setting INTERFACE items on IMPORTED targets.

Changed in version 3.13: Relative source file paths are interpreted as being relative to the current source directory (i.e. CMAKE_CURRENT_SOURCE_DIR). See policy CMP0076.

A path that begins with a generator expression is left unmodified. When a target's SOURCE_DIR property differs from CMAKE_CURRENT_SOURCE_DIR, use absolute paths in generator expressions to ensure the sources are correctly assigned to the target.

    # WRONG: starts with generator expression, but relative path used
    target_sources(MyTarget PRIVATE "$<$<CONFIG:Debug>:dbgsrc.cpp>")
    # CORRECT: absolute path used inside the generator expression
    target_sources(MyTarget PRIVATE "$<$<CONFIG:Debug>:${CMAKE_CURRENT_SOURCE_DIR}/dbgsrc.cpp>")

See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

  File Sets

Added in version 3.23.

    target_sources(<target>
      [<INTERFACE|PUBLIC|PRIVATE>
       [FILE_SET <set> [TYPE <type>] [BASE_DIRS <dirs>...] [FILES <files>...]]...
      ]...)

Adds a file set to a target, or adds files to an existing file set. Targets have zero or more named file sets. Each file set has a name, a type, a scope of INTERFACE, PUBLIC, or PRIVATE, one or more base directories, and files within those directories. The acceptable types include:

HEADERS Sources intended to be used via a language's #include mechanism.

CXX_MODULES
    Added in version 3.28.

    Sources which contain C++ interface module or partition units (i.e., those using the export keyword). This file set type may not have an INTERFACE scope except on IMPORTED targets.

    The optional default file sets are named after their type. The target may not be a custom target or FRAMEWORK target.

    Files in a PRIVATE or PUBLIC file set are marked as source files for the purposes of IDE integration. Additionally, files in HEADERS file sets have their HEADER_FILE_ONLY property set to TRUE. Files in an INTERFACE or PUBLIC file set can be installed with the install(TARGETS) command, and exported with the install(EXPORT) and export() commands.

    Each target_sources(FILE_SET) entry starts with INTERFACE, PUBLIC, or PRIVATE and accepts the following arguments:

    FILE_SET <set> The name of the file set to create or add to. It must contain only letters, numbers and underscores. Names starting with a capital letter are reserved for built-in file sets predefined by CMake. The only predefined set names are those matching the acceptable types. All other set names must not start with a capital letter or underscore.

    TYPE <type> Every file set is associated with a particular type of file. Only types specified above may be used and it is an error to specify anything else. As a special case, if the name of the file set is one of the types, the type does not need to be specified and the TYPE <type> arguments can be omitted. For all other file set names, TYPE is required.

    BASE_DIRS <dirs>... An optional list of base directories of the file set. Any relative path is treated as relative to the current source directory (i.e. CMAKE_CURRENT_SOURCE_DIR). If no BASE_DIRS are specified when the file set is first created, the value of CMAKE_CURRENT_SOURCE_DIR is added. This argument supports generator expressions.

    No two base directories for a file set may be sub-directories of each other. This requirement must be met across all base directories added to a file set, not just those within a single call to target_sources().

    FILES <files>... An optional list of files to add to the file set. Each file must be in one of the base directories, or a subdirectory of one of the base directories. This argument supports generator expressions.

    If relative paths are specified, they are considered relative to CMAKE_CURRENT_SOURCE_DIR at the time target_sources() is called. An exception to this is a path starting with $<. Such paths are treated as relative to the target's source directory after evaluation of generator expressions.

    The following target properties are set by target_sources(FILE_SET), but they should not generally be manipulated directly:

    For file sets of type HEADERS:

•   HEADER_SETS

•   INTERFACE_HEADER_SETS

•   HEADER_SET

•   HEADER_SET_<NAME>

•   HEADER_DIRS

•   HEADER_DIRS_<NAME>

    For file sets of type CXX_MODULES:

•   CXX_MODULE_SETS

•   INTERFACE_CXX_MODULE_SETS

•   CXX_MODULE_SET

•   CXX_MODULE_SET_<NAME>

•   CXX_MODULE_DIRS

•   CXX_MODULE_DIRS_<NAME>

    Target properties related to include directories are also modified by target_sources(FILE_SET) as follows:

    INCLUDE_DIRECTORIES If the TYPE is HEADERS, and the scope of the file set is PRIVATE or PUBLIC, all of the BASE_DIRS of the file set are wrapped in $<BUILD_INTERFACE> and appended to this property.

    INTERFACE_INCLUDE_DIRECTORIES If the TYPE is HEADERS, and the scope of the file set is INTERFACE or PUBLIC, all of the BASE_DIRS of the file set are wrapped in $<BUILD_INTERFACE> and appended to this property.

  See Also

•   add_executable()

•   add_library()

•   target_compile_definitions()

•   target_compile_features()

•   target_compile_options()

•   target_include_directories()

•   target_link_libraries()

•   target_link_directories()

•   target_link_options()

•   target_precompile_headers()

  try_compile

Try building some code.

  Try Compiling Whole Projects

    try_compile(<compileResultVar> PROJECT <projectName>
                SOURCE_DIR <srcdir>
                [BINARY_DIR <bindir>]
                [TARGET <targetName>]
                [LOG_DESCRIPTION <text>]
                [NO_CACHE]
                [NO_LOG]
                [CMAKE_FLAGS <flags>...]
                [OUTPUT_VARIABLE <var>])

Added in version 3.25.

Try building a project. Build success returns TRUE and build failure returns FALSE in <compileResultVar>.

In this form, <srcdir> should contain a complete CMake project with a CMakeLists.txt file and all sources. The <bindir> and <srcdir> will not be deleted after this command is run. Specify <targetName> to build a specific target instead of the all or ALL_BUILD target. See below for the meaning of other options.

Changed in version 3.24: CMake variables describing platform settings, and those listed by the CMAKE_TRY_COMPILE_PLATFORM_VARIABLES variable, are propagated into the project's build configuration. See policy CMP0137. Previously this was only done by the source file signature.

Added in version 3.26: This command records a configure-log try_compile event if the NO_LOG option is not specified.

Added in version 3.30: If the PROPAGATE_TOP_LEVEL_INCLUDES_TO_TRY_COMPILE global property is set to true, CMAKE_PROJECT_TOP_LEVEL_INCLUDES is propagated into the project's build configuration.

This command supports an alternate signature for CMake older than 3.25. The signature above is recommended for clarity.

    try_compile(<compileResultVar> <bindir> <srcdir>
                <projectName> [<targetName>]
                [CMAKE_FLAGS <flags>...]
                [OUTPUT_VARIABLE <var>])

  Try Compiling Source Files

    try_compile(<compileResultVar>
                [SOURCES_TYPE <type>]
                <SOURCES <srcfile...>                 |
                 SOURCE_FROM_CONTENT <name> <content> |
                 SOURCE_FROM_VAR <name> <var>         |
                 SOURCE_FROM_FILE <name> <path>       >...
                [LOG_DESCRIPTION <text>]
                [NO_CACHE]
                [NO_LOG]
                [CMAKE_FLAGS <flags>...]
                [COMPILE_DEFINITIONS <defs>...]
                [LINK_OPTIONS <options>...]
                [LINK_LIBRARIES <libs>...]
                [LINKER_LANGUAGE <lang>]
                [OUTPUT_VARIABLE <var>]
                [COPY_FILE <fileName> [COPY_FILE_ERROR <var>]]
                [<LANG>_STANDARD <std>]
                [<LANG>_STANDARD_REQUIRED <bool>]
                [<LANG>_EXTENSIONS <bool>]
                )

Added in version 3.25.

Try building an executable or static library from one or more source files. The binary type is determined by variable CMAKE_TRY_COMPILE_TARGET_TYPE. Build success returns boolean true and build failure returns boolean false in <compileResultVar> (cached unless NO_CACHE is specified).

In this form, one or more source files must be provided. Additionally, one of SOURCES and/or SOURCE_FROM_* must precede other keywords.

If CMAKE_TRY_COMPILE_TARGET_TYPE is unset or is set to EXECUTABLE, the sources must include a definition for main and CMake will create a CMakeLists.txt file to build the source(s) as an executable. If CMAKE_TRY_COMPILE_TARGET_TYPE is set to STATIC_LIBRARY, a static library will be built instead and no definition for main is required. For an executable, the generated CMakeLists.txt file would contain something like the following:

    add_definitions(<expanded COMPILE_DEFINITIONS from caller>)
    include_directories(${INCLUDE_DIRECTORIES})
    link_directories(${LINK_DIRECTORIES})
    add_executable(cmTryCompileExec <srcfile>...)
    target_link_options(cmTryCompileExec PRIVATE <LINK_OPTIONS from caller>)
    target_link_libraries(cmTryCompileExec ${LINK_LIBRARIES})

CMake automatically generates, for each try_compile operation, a unique directory under ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeScratch with an unspecified name. These directories are cleaned automatically unless --debug-trycompile is passed to cmake. Such directories from previous runs are also unconditionally cleaned at the beginning of any cmake execution.

This command supports an alternate signature for CMake older than 3.25. The signature above is recommended for clarity.

    try_compile(<compileResultVar> <bindir> <srcfile|SOURCES srcfile...>
                [CMAKE_FLAGS <flags>...]
                [COMPILE_DEFINITIONS <defs>...]
                [LINK_OPTIONS <options>...]
                [LINK_LIBRARIES <libs>...]
                [OUTPUT_VARIABLE <var>]
                [COPY_FILE <fileName> [COPY_FILE_ERROR <var>]]
                [<LANG>_STANDARD <std>]
                [<LANG>_STANDARD_REQUIRED <bool>]
                [<LANG>_EXTENSIONS <bool>]
                )

In this version, try_compile will use <bindir>/CMakeFiles/CMakeTmp for its operation, and all such files will be cleaned automatically. For debugging, --debug-trycompile can be passed to cmake to avoid this clean. However, multiple sequential try_compile operations, if given the same <bindir>, will reuse this single output directory, such that you can only debug one such try_compile call at a time. Use of the newer signature is recommended to simplify debugging of multiple try_compile operations.

  Options

The options for the above signatures are:

CMAKE_FLAGS <flags>...
    Specify flags of the form -DVAR:TYPE=VALUE to be passed to the cmake(1) command-line used to drive the test build. The above example shows how values for variables COMPILE_DEFINITIONS, INCLUDE_DIRECTORIES, LINK_DIRECTORIES, LINK_LIBRARIES, and LINK_OPTIONS are used. Compiler options can be passed in like CMAKE_FLAGS -DCOMPILE_DEFINITIONS=-Werror.

COMPILE_DEFINITIONS <defs>...
    Specify -Ddefinition arguments to pass to add_definitions() in the generated test project.

COPY_FILE <fileName>
    Copy the built executable or static library to the given <fileName>.

COPY_FILE_ERROR <var>
    Use after COPY_FILE to capture into variable <var> any error message encountered while trying to copy the file.

LINK_LIBRARIES <libs>...
    Specify libraries to be linked in the generated project. The list of libraries may refer to system libraries and to Imported Targets from the calling project.

    If this option is specified, any -DLINK_LIBRARIES=... value given to the CMAKE_FLAGS option will be ignored.

    Added in version 3.29: Alias targets to imported libraries are also supported.

LINK_OPTIONS <options>...
    Added in version 3.14.

    Specify link step options to pass to target_link_options() or to set the STATIC_LIBRARY_OPTIONS target property in the generated project, depending on the CMAKE_TRY_COMPILE_TARGET_TYPE variable.

LINKER_LANGUAGE <lang>
    Added in version 3.29.

    Specify the LINKER_LANGUAGE target property of the generated project. When using multiple source files with different languages, set this to the language of the source file containing the program entry point, e.g., main.

LOG_DESCRIPTION <text>
    Added in version 3.26.

    Specify a non-empty text description of the purpose of the check. This is recorded in the cmake-configure-log(7) entry.

NO_CACHE
    Added in version 3.25.

    <compileResultVar> will be stored in a normal variable rather than a cache entry.

    <compileResultVar> is normally cached so that a simple pattern can be used to avoid repeating the test on subsequent executions of CMake:

        if(NOT DEFINED RESULTVAR)
          # ...(check-specific setup code)...
          try_compile(RESULTVAR ...)
          # ...(check-specific logging and cleanup code)...
        endif()

    If the guard variable and result variable are not the same (for example, if the test is part of a larger inspection), NO_CACHE may be useful to avoid leaking the intermediate result variable into the cache.

NO_LOG
    Added in version 3.26.

    Do not record a cmake-configure-log(7) entry for this call.

OUTPUT_VARIABLE <var>
    Store the output from the build process in the given variable.

SOURCE_FROM_CONTENT <name> <content>
    Added in version 3.25.

    Write <content> to a file named <name> in the operation directory. This can be used to bypass the need to separately write a source file when the contents of the file are dynamically specified. The specified <name> is not allowed to contain path components.

    SOURCE_FROM_CONTENT may be specified multiple times.

SOURCE_FROM_FILE <name> <path>
    Added in version 3.25.

    Copy <path> to a file named <name> in the operation directory. This can be used to consolidate files into the operation directory, which may be useful if a source which already exists (i.e. as a stand-alone file in a project's source repository) needs to refer to other file(s) created by SOURCE_FROM_*. (Otherwise, SOURCES is usually more convenient.) The specified <name> is not allowed to contain path components.

SOURCE_FROM_VAR <name> <var>
    Added in version 3.25.

    Write the contents of <var> to a file named <name> in the operation directory. This is the same as SOURCE_FROM_CONTENT, but takes the contents from the specified CMake variable, rather than directly, which may be useful when passing arguments through a function which wraps try_compile. The specified <name> is not allowed to contain path components.

    SOURCE_FROM_VAR may be specified multiple times.

SOURCES_TYPE <type>
    Added in version 3.28.

    Sources may be classified using the SOURCES_TYPE argument. Once specified, all subsequent sources specified will be treated as that type until another SOURCES_TYPE is given. Available types are:

NORMAL
    Sources are not added to any FILE_SET in the generated project.

CXX_MODULE
    Added in version 3.28.

    Sources are added to a FILE_SET of type CXX_MODULES in the generated project.

    The default type of sources is NORMAL.

<LANG>_STANDARD <std>
    Added in version 3.8.

    Specify the C_STANDARD, CXX_STANDARD, OBJC_STANDARD, OBJCXX_STANDARD, or CUDA_STANDARD target property of the generated project.

<LANG>_STANDARD_REQUIRED <bool>
    Added in version 3.8.

    Specify the C_STANDARD_REQUIRED, CXX_STANDARD_REQUIRED, OBJC_STANDARD_REQUIRED, OBJCXX_STANDARD_REQUIRED,or CUDA_STANDARD_REQUIRED target property of the generated project.

<LANG>_EXTENSIONS <bool>
    Added in version 3.8.

    Specify the C_EXTENSIONS, CXX_EXTENSIONS, OBJC_EXTENSIONS, OBJCXX_EXTENSIONS, or CUDA_EXTENSIONS target property of the generated project.

  Other Behavior Settings

Added in version 3.4: If set, the following variables are passed in to the generated try_compile CMakeLists.txt to initialize compile target properties with default values:

•   CMAKE_CUDA_RUNTIME_LIBRARY

•   CMAKE_ENABLE_EXPORTS

•   CMAKE_EXE_LINKER_FLAGS, unless using CMake versions prior to 4.0 without policy CMP0056 set to NEW

•   CMAKE_LINK_SEARCH_START_STATIC

•   CMAKE_LINK_SEARCH_END_STATIC

•   CMAKE_MSVC_RUNTIME_LIBRARY

•   CMAKE_POSITION_INDEPENDENT_CODE

•   CMAKE_WATCOM_RUNTIME_LIBRARY

    Changed in version 3.14: If CMP0083 is set to NEW, then in order to obtain correct behavior at link time, the check_pie_supported() command from the CheckPIESupported module must be called before using the try_compile command.

    Some policies are set automatically in the generated test project as needed to honor the state of the calling project:

•   CMP0065 (in CMake versions prior to 4.0)

•   CMP0083

•   CMP0091

•   CMP0104

•   CMP0123

•   CMP0126

•   CMP0128

•   CMP0136

•   CMP0141

•   CMP0155

•   CMP0157

•   CMP0181

•   CMP0184

    Added in version 4.0: The current setting of CMP0181 policy is propagated through to the generated test project.

    Set variable CMAKE_TRY_COMPILE_CONFIGURATION to choose a build configuration:

•   For multi-config generators, this selects which configuration to build.

•   For single-config generators, this sets CMAKE_BUILD_TYPE in the test project.

    Added in version 3.6: Set the CMAKE_TRY_COMPILE_TARGET_TYPE variable to specify the type of target used for the source file signature.

    Added in version 3.6: Set the CMAKE_TRY_COMPILE_PLATFORM_VARIABLES variable to specify variables that must be propagated into the test project. This variable is meant for use only in toolchain files and is only honored by the try_compile() command for the source files form, not when given a whole project.

    Changed in version 3.8: If CMP0067 is set to NEW, or any of the <LANG>_STANDARD, <LANG>_STANDARD_REQUIRED, or <LANG>_EXTENSIONS options are used, then the language standard variables are honored:

•   CMAKE_C_STANDARD

•   CMAKE_C_STANDARD_REQUIRED

•   CMAKE_C_EXTENSIONS

•   CMAKE_CXX_STANDARD

•   CMAKE_CXX_STANDARD_REQUIRED

•   CMAKE_CXX_EXTENSIONS

•   CMAKE_OBJC_STANDARD

•   CMAKE_OBJC_STANDARD_REQUIRED

•   CMAKE_OBJC_EXTENSIONS

•   CMAKE_OBJCXX_STANDARD

•   CMAKE_OBJCXX_STANDARD_REQUIRED

•   CMAKE_OBJCXX_EXTENSIONS

•   CMAKE_CUDA_STANDARD

•   CMAKE_CUDA_STANDARD_REQUIRED

•   CMAKE_CUDA_EXTENSIONS

    Their values are used to set the corresponding target properties in the generated project (unless overridden by an explicit option).

    Changed in version 3.14: For the Green Hills MULTI generator, the GHS toolset and target system customization cache variables are also propagated into the test project.

    Added in version 3.24: The CMAKE_TRY_COMPILE_NO_PLATFORM_VARIABLES variable may be set to disable passing platform variables into the test project.

    Added in version 3.25: If CMP0141 is set to NEW, one can use CMAKE_MSVC_DEBUG_INFORMATION_FORMAT to specify the MSVC debug information format.

    Added in version 3.30: If the PROPAGATE_TOP_LEVEL_INCLUDES_TO_TRY_COMPILE global property is set to true, CMAKE_PROJECT_TOP_LEVEL_INCLUDES is propagated into the test project's build configuration when using the whole-project signature.

    Added in version 4.0: If CMP0184 is set to NEW, one can use CMAKE_MSVC_RUNTIME_CHECKS to specify the enabled MSVC runtime checks.

  See Also

•   try_run()

  try_run

Try compiling and then running some code.

  Try Compiling and Running Source Files

    try_run(<runResultVar> <compileResultVar>
            [SOURCES_TYPE <type>]
            <SOURCES <srcfile...>                 |
             SOURCE_FROM_CONTENT <name> <content> |
             SOURCE_FROM_VAR <name> <var>         |
             SOURCE_FROM_FILE <name> <path>       >...
            [LOG_DESCRIPTION <text>]
            [NO_CACHE]
            [NO_LOG]
            [CMAKE_FLAGS <flags>...]
            [COMPILE_DEFINITIONS <defs>...]
            [LINK_OPTIONS <options>...]
            [LINK_LIBRARIES <libs>...]
            [COMPILE_OUTPUT_VARIABLE <var>]
            [COPY_FILE <fileName> [COPY_FILE_ERROR <var>]]
            [<LANG>_STANDARD <std>]
            [<LANG>_STANDARD_REQUIRED <bool>]
            [<LANG>_EXTENSIONS <bool>]
            [RUN_OUTPUT_VARIABLE <var>]
            [RUN_OUTPUT_STDOUT_VARIABLE <var>]
            [RUN_OUTPUT_STDERR_VARIABLE <var>]
            [WORKING_DIRECTORY <var>]
            [ARGS <args>...]
            )

Added in version 3.25.

Try building an executable from one or more source files. Build success returns boolean true and build failure returns boolean false in <compileResultVar> (cached unless NO_CACHE is specified). If the build succeeds, this runs the executable and stores the exit code in <runResultVar> (cached unless NO_CACHE is specified). If the executable was built, but failed to run, then <runResultVar> will be set to FAILED_TO_RUN. See command try_compile() for documentation of options common to both commands, and for information on how the test project is constructed to build the source file.

One or more source files must be provided. Additionally, one of SOURCES and/or SOURCE_FROM_* must precede other keywords.

Added in version 3.26: This command records a configure-log try_run event if the NO_LOG option is not specified.

This command supports an alternate signature for CMake older than 3.25. The signature above is recommended for clarity.

    try_run(<runResultVar> <compileResultVar>
            <bindir> <srcfile|SOURCES srcfile...>
            [CMAKE_FLAGS <flags>...]
            [COMPILE_DEFINITIONS <defs>...]
            [LINK_OPTIONS <options>...]
            [LINK_LIBRARIES <libs>...]
            [LINKER_LANGUAGE <lang>]
            [COMPILE_OUTPUT_VARIABLE <var>]
            [COPY_FILE <fileName> [COPY_FILE_ERROR <var>]]
            [<LANG>_STANDARD <std>]
            [<LANG>_STANDARD_REQUIRED <bool>]
            [<LANG>_EXTENSIONS <bool>]
            [RUN_OUTPUT_VARIABLE <var>]
            [OUTPUT_VARIABLE <var>]
            [WORKING_DIRECTORY <var>]
            [ARGS <args>...]
            )

  Options

The options specific to try_run are:

COMPILE_OUTPUT_VARIABLE <var>
    Report the compile step build output in a given variable.

OUTPUT_VARIABLE <var>
    Report the compile build output and the output from running the executable in the given variable. This option exists for legacy reasons and is only supported by the old try_run signature. Prefer COMPILE_OUTPUT_VARIABLE and RUN_OUTPUT_VARIABLE instead.

RUN_OUTPUT_VARIABLE <var>
    Report the output from running the executable in a given variable.

RUN_OUTPUT_STDOUT_VARIABLE <var>
    Added in version 3.25.

    Report the output of stdout from running the executable in a given variable.

RUN_OUTPUT_STDERR_VARIABLE <var>
    Added in version 3.25.

    Report the output of stderr from running the executable in a given variable.

WORKING_DIRECTORY <var>
    Added in version 3.20.

    Run the executable in the given directory. If no WORKING_DIRECTORY is specified, the executable will run in <bindir> or the current build directory.

ARGS <args>...
    Additional arguments to pass to the executable when running it.

  Other Behavior Settings

Set variable CMAKE_TRY_COMPILE_CONFIGURATION to choose a build configuration:

•   For multi-config generators, this selects which configuration to build.

•   For single-config generators, this sets CMAKE_BUILD_TYPE in the test project.

  Behavior when Cross Compiling

Added in version 3.3: Use CMAKE_CROSSCOMPILING_EMULATOR when running cross-compiled binaries.

When cross compiling, the executable compiled in the first step usually cannot be run on the build host. The try_run command checks the CMAKE_CROSSCOMPILING variable to detect whether CMake is in cross-compiling mode. If that is the case, it will still try to compile the executable, but it will not try to run the executable unless the CMAKE_CROSSCOMPILING_EMULATOR variable is set. Instead it will create cache variables which must be filled by the user or by presetting them in some CMake script file to the values the executable would have produced if it had been run on its actual target platform. These cache entries are:

<runResultVar>
    Exit code if the executable were to be run on the target platform.

<runResultVar>__TRYRUN_OUTPUT
    Output from stdout and stderr if the executable were to be run on the target platform. This is created only if the RUN_OUTPUT_VARIABLE or OUTPUT_VARIABLE option was used.

    In order to make cross compiling your project easier, use try_run only if really required. If you use try_run, use the RUN_OUTPUT_STDOUT_VARIABLE, RUN_OUTPUT_STDERR_VARIABLE, RUN_OUTPUT_VARIABLE or OUTPUT_VARIABLE options only if really required. Using them will require that when cross-compiling, the cache variables will have to be set manually to the output of the executable. You can also "guard" the calls to try_run with an if() block checking the CMAKE_CROSSCOMPILING variable and provide an easy-to-preset alternative for this case.

CTEST COMMANDS

These commands are available only in CTest scripts.

  ctest_build

Perform the CTest Build Step as a Dashboard Client.

    ctest_build([BUILD <build-dir>] [APPEND]
                [CONFIGURATION <config>]
                [PARALLEL_LEVEL <parallel>]
                [FLAGS <flags>]
                [PROJECT_NAME <project-name>]
                [TARGET <target-name>]
                [NUMBER_ERRORS <num-err-var>]
                [NUMBER_WARNINGS <num-warn-var>]
                [RETURN_VALUE <result-var>]
                [CAPTURE_CMAKE_ERROR <result-var>]
                )

Build the project and store results in Build.xml for submission with the ctest_submit() command.

The CTEST_BUILD_COMMAND variable may be set to explicitly specify the build command line. Otherwise the build command line is computed automatically based on the options given.

The options are:

BUILD <build-dir>
    Specify the top-level build directory. If not given, the CTEST_BINARY_DIRECTORY variable is used.

APPEND
    Mark Build.xml for append to results previously submitted to a dashboard server since the last ctest_start() call. Append semantics are defined by the dashboard server in use. This does not cause results to be appended to a .xml file produced by a previous call to this command.

CONFIGURATION <config>
    Specify the build configuration (e.g. Debug). If not specified the CTEST_BUILD_CONFIGURATION variable will be checked. Otherwise the -C <cfg> option given to the ctest(1) command will be used, if any.

PARALLEL_LEVEL <parallel>
    Added in version 3.21.

    Specify the parallel level of the underlying build system. If not specified, the CMAKE_BUILD_PARALLEL_LEVEL environment variable will be checked.

FLAGS <flags>
    Pass additional arguments to the underlying build command. If not specified the CTEST_BUILD_FLAGS variable will be checked. This can, e.g., be used to trigger a parallel build using the -j option of make. See the ProcessorCount module for an example.

PROJECT_NAME <project-name>
    Ignored since CMake 3.0.

    Changed in version 3.14: This value is no longer required.

TARGET <target-name>
    Specify the name of a target to build. If not specified the CTEST_BUILD_TARGET variable will be checked. Otherwise the default target will be built. This is the "all" target (called ALL_BUILD in Visual Studio Generators).

NUMBER_ERRORS <num-err-var>
    Store the number of build errors detected in the given variable.

NUMBER_WARNINGS <num-warn-var>
    Store the number of build warnings detected in the given variable.

RETURN_VALUE <result-var>
    Store the return value of the native build tool in the given variable.

CAPTURE_CMAKE_ERROR <result-var>
    Added in version 3.7.

    Store in the <result-var> variable -1 if there are any errors running the command and prevent ctest from returning non-zero if an error occurs.

QUIET
    Added in version 3.3.

    Suppress any CTest-specific non-error output that would have been printed to the console otherwise. The summary of warnings / errors, as well as the output from the native build tool is unaffected by this option.

  ctest_configure

Perform the CTest Configure Step as a Dashboard Client.

    ctest_configure([BUILD <build-dir>] [SOURCE <source-dir>] [APPEND]
                    [OPTIONS <options>] [RETURN_VALUE <result-var>] [QUIET]
                    [CAPTURE_CMAKE_ERROR <result-var>])

Configure the project build tree and record results in Configure.xml for submission with the ctest_submit() command.

The options are:

BUILD <build-dir>
    Specify the top-level build directory. If not given, the CTEST_BINARY_DIRECTORY variable is used.

SOURCE <source-dir>
    Specify the source directory. If not given, the CTEST_SOURCE_DIRECTORY variable is used.

APPEND
    Mark Configure.xml for append to results previously submitted to a dashboard server since the last ctest_start() call. Append semantics are defined by the dashboard server in use. This does not cause results to be appended to a .xml file produced by a previous call to this command.

OPTIONS <options>
    Specify command-line arguments to pass to the configuration tool.

RETURN_VALUE <result-var>
    Store in the <result-var> variable the return value of the native configuration tool.

CAPTURE_CMAKE_ERROR <result-var>
    Added in version 3.7.

    Store in the <result-var> variable -1 if there are any errors running the command and prevent ctest from returning non-zero if an error occurs.

QUIET
    Added in version 3.3.

    Suppress any CTest-specific non-error messages that would have otherwise been printed to the console. Output from the underlying configure command is not affected.

  ctest_coverage

Perform the CTest Coverage Step as a Dashboard Client.

    ctest_coverage([BUILD <build-dir>] [APPEND]
                   [LABELS <label>...]
                   [RETURN_VALUE <result-var>]
                   [CAPTURE_CMAKE_ERROR <result-var>]
                   [QUIET]
                   )

Collect coverage tool results and stores them in Coverage.xml for submission with the ctest_submit() command.

The options are:

BUILD <build-dir>
    Specify the top-level build directory. If not given, the CTEST_BINARY_DIRECTORY variable is used.

APPEND
    Mark Coverage.xml for append to results previously submitted to a dashboard server since the last ctest_start() call. Append semantics are defined by the dashboard server in use. This does not cause results to be appended to a .xml file produced by a previous call to this command.

LABELS
    Filter the coverage report to include only source files labeled with at least one of the labels specified.

RETURN_VALUE <result-var>
    Store in the <result-var> variable 0 if coverage tools ran without error and non-zero otherwise.

CAPTURE_CMAKE_ERROR <result-var>
    Added in version 3.7.

    Store in the <result-var> variable -1 if there are any errors running the command and prevent ctest from returning non-zero if an error occurs.

QUIET
    Added in version 3.3.

    Suppress any CTest-specific non-error output that would have been printed to the console otherwise. The summary indicating how many lines of code were covered is unaffected by this option.

  ctest_empty_binary_directory

empties the binary directory

    ctest_empty_binary_directory(<directory>)

Removes a binary directory. This command will perform some checks prior to deleting the directory in an attempt to avoid malicious or accidental directory deletion.

  ctest_memcheck

Perform the CTest MemCheck Step as a Dashboard Client.

    ctest_memcheck([BUILD <build-dir>] [APPEND]
                   [START <start-number>]
                   [END <end-number>]
                   [STRIDE <stride-number>]
                   [EXCLUDE <exclude-regex>]
                   [INCLUDE <include-regex>]
                   [EXCLUDE_LABEL <label-exclude-regex>]
                   [INCLUDE_LABEL <label-include-regex>]
                   [EXCLUDE_FIXTURE <regex>]
                   [EXCLUDE_FIXTURE_SETUP <regex>]
                   [EXCLUDE_FIXTURE_CLEANUP <regex>]
                   [PARALLEL_LEVEL <level>]
                   [RESOURCE_SPEC_FILE <file>]
                   [TEST_LOAD <threshold>]
                   [SCHEDULE_RANDOM <ON|OFF>]
                   [STOP_ON_FAILURE]
                   [STOP_TIME <time-of-day>]
                   [RETURN_VALUE <result-var>]
                   [CAPTURE_CMAKE_ERROR <result-var>]
                   [REPEAT <mode>:<n>]
                   [OUTPUT_JUNIT <file>]
                   [DEFECT_COUNT <defect-count-var>]
                   [QUIET]
                   )

Run tests with a dynamic analysis tool and store results in MemCheck.xml for submission with the ctest_submit() command.

Most options are the same as those for the ctest_test() command.

The options unique to this command are:

DEFECT_COUNT <defect-count-var>
    Added in version 3.8.

    Store in the <defect-count-var> the number of defects found.

  ctest_read_custom_files

read CTestCustom files.

    ctest_read_custom_files(<directory>...)

Read all the CTestCustom.ctest or CTestCustom.cmake files from the given directory.

By default, invoking ctest(1) without a script will read custom files from the binary directory.

  ctest_run_script

runs a ctest -S script

    ctest_run_script([NEW_PROCESS] script_file_name script_file_name1
                script_file_name2 ... [RETURN_VALUE var])

Runs a script or scripts much like if it was run from ctest -S. If NEW_PROCESS is specified then each script will be run in a separate process. If RETURN_VALUE is specified the return value of the last script run will be put into var.

  ctest_sleep

sleeps for some amount of time

    ctest_sleep(<seconds>)

Sleep for given number of seconds.

    ctest_sleep(<time1> <duration> <time2>)

Sleep for t=(time1 + duration - time2) seconds if t > 0.

  ctest_start

Starts the testing for a given model

    ctest_start(<model> [<source> [<binary>]] [GROUP <group>] [QUIET])
    ctest_start([<model> [<source> [<binary>]]] [GROUP <group>] APPEND [QUIET])

Starts the testing for a given model. The command should be called after the binary directory is initialized.

The parameters are as follows:

<model>
    Set the dashboard model. Must be one of Experimental, Continuous, or Nightly. This parameter is required unless APPEND is specified.

<source>
    Set the source directory. If not specified, the value of CTEST_SOURCE_DIRECTORY is used instead.

<binary>
    Set the binary directory. If not specified, the value of CTEST_BINARY_DIRECTORY is used instead.

GROUP <group>
    If GROUP is used, the submissions will go to the specified group on the CDash server. If no GROUP is specified, the name of the model is used by default.

    Changed in version 3.16: This replaces the deprecated option TRACK. Despite the name change its behavior is unchanged.

APPEND
    If APPEND is used, the existing TAG is used rather than creating a new one based on the current time stamp. If you use APPEND, you can omit the <model> and GROUP <group> parameters, because they will be read from the generated TAG file. For example:

        ctest_start(Experimental GROUP GroupExperimental)

    Later, in another ctest -S script:

        ctest_start(APPEND)

    When the second script runs ctest_start(APPEND), it will read the Experimental model and GroupExperimental group from the TAG file generated by the first ctest_start() command. Please note that if you call ctest_start(APPEND) and specify a different model or group than in the first ctest_start() command, a warning will be issued, and the new model and group will be used.

QUIET
    Added in version 3.3.

    If QUIET is used, CTest will suppress any non-error messages that it otherwise would have printed to the console.

    The parameters for ctest_start() can be issued in any order, with the exception that <model>, <source>, and <binary> have to appear in that order with respect to each other. The following are all valid and equivalent:

        ctest_start(Experimental path/to/source path/to/binary GROUP SomeGroup QUIET APPEND)
        ctest_start(GROUP SomeGroup Experimental QUIET path/to/source APPEND path/to/binary)
        ctest_start(APPEND QUIET Experimental path/to/source GROUP SomeGroup path/to/binary)

    However, for the sake of readability, it is recommended that you order your parameters in the order listed at the top of this page.

    If the CTEST_CHECKOUT_COMMAND variable (or the CTEST_CVS_CHECKOUT variable) is set, its content is treated as command-line. The command is invoked with the current working directory set to the parent of the source directory, even if the source directory already exists. This can be used to create the source tree from a version control repository.

  ctest_submit

Perform the CTest Submit Step as a Dashboard Client.

    ctest_submit([PARTS <part>...] [FILES <file>...]
                 [SUBMIT_URL <url>]
                 [BUILD_ID <result-var>]
                 [HTTPHEADER <header>]
                 [RETRY_COUNT <count>]
                 [RETRY_DELAY <delay>]
                 [RETURN_VALUE <result-var>]
                 [CAPTURE_CMAKE_ERROR <result-var>]
                 [QUIET]
                 )

Submit results to a dashboard server. By default all available parts are submitted.

The options are:

PARTS <part>...
    Specify a subset of parts to submit. Valid part names are:

•   Start - nothing.

•   Update - ctest_update() results, in Update.xml.

•   Configure - ctest_configure() results, in Configure.xml.

•   Build - ctest_build() results, in Build.xml.

•   Test - ctest_test() results, in Test.xml.

•   Coverage - ctest_coverage() results, in Coverage.xml.

•   MemCheck - ctest_memcheck() results, in DynamicAnalysis.xml and DynamicAnalysis-Test.xml.

•   Notes - Files listed by CTEST_NOTES_FILES, in Notes.xml.

•   ExtraFiles - Files listed by CTEST_EXTRA_SUBMIT_FILES.

•   Upload - Files prepared for upload by ctest_upload(), in Upload.xml.

•   Submit - nothing.

•   Done - Build is complete, in Done.xml.

FILES <file>...
    Specify an explicit list of specific files to be submitted. Each individual file must exist at the time of the call.

SUBMIT_URL <url>
    Added in version 3.14.

    The http or https URL of the dashboard server to send the submission to. If not given, the CTEST_SUBMIT_URL variable is used.

BUILD_ID <result-var>
    Added in version 3.15.

    Store in the <result-var> variable the ID assigned to this build by CDash.

HTTPHEADER <HTTP-header>
    Added in version 3.9.

    Specify HTTP header to be included in the request to CDash during submission. For example, CDash can be configured to only accept submissions from authenticated clients. In this case, you should provide a bearer token in your header:

        ctest_submit(HTTPHEADER "Authorization: Bearer <auth-token>")

    This suboption can be repeated several times for multiple headers.

RETRY_COUNT <count>
    Specify how many times to retry a timed-out submission.

RETRY_DELAY <delay>
    Specify how long (in seconds) to wait after a timed-out submission before attempting to re-submit.

RETURN_VALUE <result-var>
    Store in the <result-var> variable 0 for success and non-zero on failure.

CAPTURE_CMAKE_ERROR <result-var>
    Added in version 3.13.

    Store in the <result-var> variable -1 if there are any errors running the command and prevent ctest from returning non-zero if an error occurs.

QUIET
    Added in version 3.3.

    Suppress all non-error messages that would have otherwise been printed to the console.

  Submit to CDash Upload API

Added in version 3.2.

    ctest_submit(CDASH_UPLOAD <file> [CDASH_UPLOAD_TYPE <type>]
                 [SUBMIT_URL <url>]
                 [BUILD_ID <result-var>]
                 [HTTPHEADER <header>]
                 [RETRY_COUNT <count>]
                 [RETRY_DELAY <delay>]
                 [RETURN_VALUE <result-var>]
                 [QUIET])

This second signature is used to upload files to CDash via the CDash file upload API. The API first sends a request to upload to CDash along with a content hash of the file. If CDash does not already have the file, then it is uploaded. Along with the file, a CDash type string is specified to tell CDash which handler to use to process the data.

This signature interprets options in the same way as the first one.

Added in version 3.8: Added the RETRY_COUNT, RETRY_DELAY, QUIET options.

Added in version 3.9: Added the HTTPHEADER option.

Added in version 3.13: Added the RETURN_VALUE option.

Added in version 3.14: Added the SUBMIT_URL option.

Added in version 3.15: Added the BUILD_ID option.

  ctest_test

Perform the CTest Test Step as a Dashboard Client.

    ctest_test([BUILD <build-dir>] [APPEND]
               [START <start-number>]
               [END <end-number>]
               [STRIDE <stride-number>]
               [EXCLUDE <exclude-regex>]
               [INCLUDE <include-regex>]
               [EXCLUDE_LABEL <label-exclude-regex>]
               [INCLUDE_LABEL <label-include-regex>]
               [EXCLUDE_FROM_FILE <filename>]
               [INCLUDE_FROM_FILE <filename>]
               [EXCLUDE_FIXTURE <regex>]
               [EXCLUDE_FIXTURE_SETUP <regex>]
               [EXCLUDE_FIXTURE_CLEANUP <regex>]
               [PARALLEL_LEVEL [<level>]]
               [RESOURCE_SPEC_FILE <file>]
               [TEST_LOAD <threshold>]
               [SCHEDULE_RANDOM <ON|OFF>]
               [STOP_ON_FAILURE]
               [STOP_TIME <time-of-day>]
               [RETURN_VALUE <result-var>]
               [CAPTURE_CMAKE_ERROR <result-var>]
               [REPEAT <mode>:<n>]
               [OUTPUT_JUNIT <file>]
               [QUIET]
               )

Run tests in the project build tree and store results in Test.xml for submission with the ctest_submit() command.

The options are:

BUILD <build-dir>
    Specify the top-level build directory. If not given, the CTEST_BINARY_DIRECTORY variable is used.

APPEND
    Mark Test.xml for append to results previously submitted to a dashboard server since the last ctest_start() call. Append semantics are defined by the dashboard server in use. This does not cause results to be appended to a .xml file produced by a previous call to this command.

START <start-number>
    Specify the beginning of a range of test numbers.

END <end-number>
    Specify the end of a range of test numbers.

STRIDE <stride-number>
    Specify the stride by which to step across a range of test numbers.

EXCLUDE <exclude-regex>
    Specify a regular expression matching test names to exclude.

INCLUDE <include-regex>
    Specify a regular expression matching test names to include. Tests not matching this expression are excluded.

EXCLUDE_LABEL <label-exclude-regex>
    Specify a regular expression matching test labels to exclude.

INCLUDE_LABEL <label-include-regex>
    Specify a regular expression matching test labels to include. Tests not matching this expression are excluded.

EXCLUDE_FROM_FILE <filename>
    Added in version 3.29.

    Do NOT run tests listed with their exact name in the given file.

INCLUDE_FROM_FILE <filename>
    Added in version 3.29.

    Only run the tests listed with their exact name in the given file.

EXCLUDE_FIXTURE <regex>
    Added in version 3.7.

    If a test in the set of tests to be executed requires a particular fixture, that fixture's setup and cleanup tests would normally be added to the test set automatically. This option prevents adding setup or cleanup tests for fixtures matching the <regex>. Note that all other fixture behavior is retained, including test dependencies and skipping tests that have fixture setup tests that fail.

EXCLUDE_FIXTURE_SETUP <regex>
    Added in version 3.7.

    Same as EXCLUDE_FIXTURE except only matching setup tests are excluded.

EXCLUDE_FIXTURE_CLEANUP <regex>
    Added in version 3.7.

    Same as EXCLUDE_FIXTURE except only matching cleanup tests are excluded.

PARALLEL_LEVEL [<level>]
    Run tests in parallel, limited to a given level of parallelism.

    Added in version 3.29: The <level> may be omitted, or 0, to let ctest use a default level of parallelism, or unbounded parallelism, respectively, as documented by the ctest --parallel option.

RESOURCE_SPEC_FILE <file>
    Added in version 3.16.

    Specify a resource specification file. See Resource Allocation for more information.

TEST_LOAD <threshold>
    Added in version 3.4.

    While running tests in parallel, try not to start tests when they may cause the CPU load to pass above a given threshold. If not specified the CTEST_TEST_LOAD variable will be checked, and then the --test-load command-line argument to ctest(1). See also the TestLoad setting in the CTest Test Step.

REPEAT <mode>:<n>
    Added in version 3.17.

    Run tests repeatedly based on the given <mode> up to <n> times. The modes are:

UNTIL_FAIL
    Require each test to run <n> times without failing in order to pass. This is useful in finding sporadic failures in test cases.

UNTIL_PASS
    Allow each test to run up to <n> times in order to pass. Repeats tests if they fail for any reason. This is useful in tolerating sporadic failures in test cases.

AFTER_TIMEOUT
    Allow each test to run up to <n> times in order to pass. Repeats tests only if they timeout. This is useful in tolerating sporadic timeouts in test cases on busy machines.

SCHEDULE_RANDOM <ON|OFF>
    Launch tests in a random order. This may be useful for detecting implicit test dependencies.

STOP_ON_FAILURE
    Added in version 3.18.

    Stop the execution of the tests once one has failed.

STOP_TIME <time-of-day>
    Specify a time of day at which the tests should all stop running.

RETURN_VALUE <result-var>
    Store in the <result-var> variable 0 if all tests passed. Store non-zero if anything went wrong.

CAPTURE_CMAKE_ERROR <result-var>
    Added in version 3.7.

    Store in the <result-var> variable -1 if there are any errors running the command and prevent ctest from returning non-zero if an error occurs.

OUTPUT_JUNIT <file>
    Added in version 3.21.

    Write test results to <file> in JUnit XML format. If <file> is a relative path, it will be placed in the build directory. If <file> already exists, it will be overwritten. Note that the resulting JUnit XML file is not uploaded to CDash because it would be redundant with CTest's Test.xml file.

QUIET
    Added in version 3.3.

    Suppress any CTest-specific non-error messages that would have otherwise been printed to the console. Output from the underlying test command is not affected. Summary info detailing the percentage of passing tests is also unaffected by the QUIET option.

    See also the CTEST_CUSTOM_MAXIMUM_PASSED_TEST_OUTPUT_SIZE, CTEST_CUSTOM_MAXIMUM_FAILED_TEST_OUTPUT_SIZE and CTEST_CUSTOM_TEST_OUTPUT_TRUNCATION variables, along with their corresponding ctest(1) command line options --test-output-size-passed, --test-output-size-failed, and --test-output-truncation.

  Additional Test Measurements

CTest can parse the output of your tests for extra measurements to report to CDash.

When run as a Dashboard Client, CTest will include these custom measurements in the Test.xml file that gets uploaded to CDash.

Check the CDash test measurement documentation for more information on the types of test measurements that CDash recognizes.

The following example demonstrates how to output a variety of custom test measurements.

    std::cout <<
      "<CTestMeasurement type=\"numeric/double\" name=\"score\">28.3</CTestMeasurement>"
      << std::endl;
    std::cout <<
      "<CTestMeasurement type=\"text/string\" name=\"color\">red</CTestMeasurement>"
      << std::endl;
    std::cout <<
      "<CTestMeasurement type=\"text/link\" name=\"CMake URL\">https://cmake.org</CTestMeasurement>"
      << std::endl;
    std::cout <<
      "<CTestMeasurement type=\"text/preformatted\" name=\"Console Output\">" <<
      "line 1.\n" <<
      "  \033[31;1m line 2. Bold red, and indented!\033[0;0ml\n" <<
      "line 3. Not bold or indented...\n" <<
      "</CTestMeasurement>" << std::endl;

  Image Measurements

The following example demonstrates how to upload test images to CDash.

    std::cout <<
      "<CTestMeasurementFile type=\"image/jpg\" name=\"TestImage\">" <<
      "/dir/to/test_img.jpg</CTestMeasurementFile>" << std::endl;
    std::cout <<
      "<CTestMeasurementFile type=\"image/gif\" name=\"ValidImage\">" <<
      "/dir/to/valid_img.gif</CTestMeasurementFile>" << std::endl;
    std::cout <<
      "<CTestMeasurementFile type=\"image/png\" name=\"AlgoResult\">" <<
      "/dir/to/img.png</CTestMeasurementFile>"
      << std::endl;

Images will be displayed together in an interactive comparison mode on CDash if they are provided with two or more of the following names.

•   TestImage

•   ValidImage

•   BaselineImage

•   DifferenceImage2

    By convention, TestImage is the image generated by your test, and ValidImage (or BaselineImage) is basis of comparison used to determine if the test passed or failed.

    If another image name is used it will be displayed by CDash as a static image separate from the interactive comparison UI.

  Attached Files

Added in version 3.21.

The following example demonstrates how to upload non-image files to CDash.

    std::cout <<
      "<CTestMeasurementFile type=\"file\" name=\"TestInputData1\">" <<
      "/dir/to/data1.csv</CTestMeasurementFile>\n"                   <<
      "<CTestMeasurementFile type=\"file\" name=\"TestInputData2\">" <<
      "/dir/to/data2.csv</CTestMeasurementFile>"                     << std::endl;

If the name of the file to upload is known at configure time, you can use the ATTACHED_FILES or ATTACHED_FILES_ON_FAIL test properties instead.

  Custom Details

Added in version 3.21.

The following example demonstrates how to specify a custom value for the Test Details field displayed on CDash.

    std::cout <<
      "<CTestDetails>My Custom Details Value</CTestDetails>" << std::endl;

  Additional Labels

Added in version 3.22.

The following example demonstrates how to add additional labels to a test at runtime.

    std::cout <<
      "<CTestLabel>Custom Label 1</CTestLabel>\n" <<
      "<CTestLabel>Custom Label 2</CTestLabel>"   << std::endl;

Use the LABELS test property instead for labels that can be determined at configure time.

  ctest_update

Perform the CTest Update Step as a Dashboard Client.

    ctest_update([SOURCE <source-dir>]
                 [RETURN_VALUE <result-var>]
                 [CAPTURE_CMAKE_ERROR <result-var>]
                 [QUIET])

Update the source tree from version control and record results in Update.xml for submission with the ctest_submit() command.

The options are:

SOURCE <source-dir>
    Specify the source directory. If not given, the CTEST_SOURCE_DIRECTORY variable is used.

RETURN_VALUE <result-var>
    Store in the <result-var> variable the number of files updated or -1 on error.

CAPTURE_CMAKE_ERROR <result-var>
    Added in version 3.13.

    Store in the <result-var> variable -1 if there are any errors running the command and prevent ctest from returning non-zero if an error occurs.

QUIET
    Added in version 3.3.

    Tell CTest to suppress most non-error messages that it would have otherwise printed to the console. CTest will still report the new revision of the repository and any conflicting files that were found.

    The update always follows the version control branch currently checked out in the source directory. See the CTest Update Step documentation for information about variables that change the behavior of ctest_update().

  ctest_upload

Upload files to a dashboard server as a Dashboard Client.

    ctest_upload(FILES <file>... [QUIET] [CAPTURE_CMAKE_ERROR <result-var>])

The options are:

FILES <file>...
    Specify a list of files to be sent along with the build results to the dashboard server.

QUIET
    Added in version 3.3.

    Suppress any CTest-specific non-error output that would have been printed to the console otherwise.

CAPTURE_CMAKE_ERROR <result-var>
    Added in version 3.7.

    Store in the <result-var> variable -1 if there are any errors running the command and prevent ctest from returning non-zero if an error occurs.

DEPRECATED COMMANDS

These commands are deprecated and are only made available to maintain backward compatibility. The documentation of each command states the CMake version in which it was deprecated. Do not use these commands in new code.

  build_name

Disallowed since version 3.0. See CMake Policy CMP0036.

Use ${CMAKE_SYSTEM} and ${CMAKE_CXX_COMPILER} instead.

    build_name(variable)

Sets the specified variable to a string representing the platform and compiler settings. These values are now available through the CMAKE_SYSTEM and CMAKE_CXX_COMPILER variables.

  exec_program

Changed in version 3.28: This command is available only if policy CMP0153 is not set to NEW. Port projects to the execute_process() command.

Deprecated since version 3.0: Use the execute_process() command instead.

Run an executable program during the processing of the CMakeList.txt file.

    exec_program(Executable [directory in which to run]
                 [ARGS <arguments to executable>]
                 [OUTPUT_VARIABLE <var>]
                 [RETURN_VALUE <var>])

The executable is run in the optionally specified directory. The executable can include arguments if it is double quoted, but it is better to use the optional ARGS argument to specify arguments to the program. This is because cmake will then be able to escape spaces in the executable path. An optional argument OUTPUT_VARIABLE specifies a variable in which to store the output. To capture the return value of the execution, provide a RETURN_VALUE. If OUTPUT_VARIABLE is specified, then no output will go to the stdout/stderr of the console running cmake.

  export_library_dependencies

Disallowed since version 3.0. See CMake Policy CMP0033.

Use install(EXPORT) or export() command.

This command generates an old-style library dependencies file. Projects requiring CMake 2.6 or later should not use the command. Use instead the install(EXPORT) command to help export targets from an installation tree and the export() command to export targets from a build tree.

The old-style library dependencies file does not take into account per-configuration names of libraries or the LINK_INTERFACE_LIBRARIES target property.

    export_library_dependencies(<file> [APPEND])

Create a file named <file> that can be included into a CMake listfile with the INCLUDE command. The file will contain a number of SET commands that will set all the variables needed for library dependency information. This should be the last command in the top level CMakeLists.txt file of the project. If the APPEND option is specified, the SET commands will be appended to the given file instead of replacing it.

  install_files

Deprecated since version 3.0: Use the install(FILES) command instead.

This command has been superseded by the install() command. It is provided for compatibility with older CMake code. The FILES form is directly replaced by the FILES form of the install() command. The regexp form can be expressed more clearly using the GLOB form of the file() command.

    install_files(<dir> extension file file ...)

Create rules to install the listed files with the given extension into the given directory. Only files existing in the current source tree or its corresponding location in the binary tree may be listed. If a file specified already has an extension, that extension will be removed first. This is useful for providing lists of source files such as foo.cxx when you want the corresponding foo.h to be installed. A typical extension is .h.

    install_files(<dir> regexp)

Any files in the current source directory that match the regular expression will be installed.

    install_files(<dir> FILES file file ...)

Any files listed after the FILES keyword will be installed explicitly from the names given. Full paths are allowed in this form.

The directory <dir> is relative to the installation prefix, which is stored in the variable CMAKE_INSTALL_PREFIX.

  install_programs

Deprecated since version 3.0: Use the install(PROGRAMS) command instead.

This command has been superseded by the install() command. It is provided for compatibility with older CMake code. The FILES form is directly replaced by the PROGRAMS form of the install() command. The regexp form can be expressed more clearly using the GLOB form of the file() command.

    install_programs(<dir> file1 file2 [file3 ...])
    install_programs(<dir> FILES file1 [file2 ...])

Create rules to install the listed programs into the given directory. Use the FILES argument to guarantee that the file list version of the command will be used even when there is only one argument.

    install_programs(<dir> regexp)

In the second form any program in the current source directory that matches the regular expression will be installed.

This command is intended to install programs that are not built by cmake, such as shell scripts. See the TARGETS form of the install() command to create installation rules for targets built by cmake.

The directory <dir> is relative to the installation prefix, which is stored in the variable CMAKE_INSTALL_PREFIX.

  install_targets

Deprecated since version 3.0: Use the install(TARGETS) command instead.

This command has been superseded by the install() command. It is provided for compatibility with older CMake code.

    install_targets(<dir> [RUNTIME_DIRECTORY dir] target target)

Create rules to install the listed targets into the given directory. The directory <dir> is relative to the installation prefix, which is stored in the variable CMAKE_INSTALL_PREFIX. If RUNTIME_DIRECTORY is specified, then on systems with special runtime files (Windows DLL), the files will be copied to that directory.

  load_command

Disallowed since version 3.0. See CMake Policy CMP0031.

Load a command into a running CMake.

    load_command(COMMAND_NAME <loc1> [loc2 ...])

The given locations are searched for a library whose name is cmCOMMAND_NAME. If found, it is loaded as a module and the command is added to the set of available CMake commands. Usually, try_compile() is used before this command to compile the module. If the command is successfully loaded a variable named CMAKE_LOADED_COMMAND_<COMMAND_NAME> will be set to the full path of the module that was loaded. Otherwise the variable will not be set.

  make_directory

Deprecated since version 3.0: Use the file(MAKE_DIRECTORY) command instead.

    make_directory(directory)

Creates the specified directory. Full paths should be given. Any parent directories that do not exist will also be created. Use with care.

  output_required_files

Disallowed since version 3.0. See CMake Policy CMP0032.

Approximate C preprocessor dependency scanning.

This command exists only because ancient CMake versions provided it. CMake handles preprocessor dependency scanning automatically using a more advanced scanner.

    output_required_files(srcfile outputfile)

Outputs a list of all the source files that are required by the specified srcfile. This list is written into outputfile. This is similar to writing out the dependencies for srcfile except that it jumps from .h files into .cxx, .c and .cpp files if possible.

  qt_wrap_cpp

Deprecated since version 3.14: This command was originally added to support Qt 3 before the add_custom_command() command was sufficiently mature. The FindQt4 module provides the qt4_wrap_cpp() macro, which should be used instead for Qt 4 projects. For projects using Qt 5 or later, use the equivalent macro provided by Qt itself (e.g. Qt 5 provides qt5_wrap_cpp()).

Manually create Qt Wrappers.

    qt_wrap_cpp(resultingLibraryName DestName SourceLists ...)

Produces moc files for all the .h files listed in the SourceLists. The moc files will be added to the library using the DestName source list.

Consider updating the project to use the AUTOMOC target property instead for a more automated way of invoking the moc tool.

  qt_wrap_ui

Deprecated since version 3.14: This command was originally added to support Qt 3 before the add_custom_command() command was sufficiently mature. The FindQt4 module provides the qt4_wrap_ui() macro, which should be used instead for Qt 4 projects. For projects using Qt 5 or later, use the equivalent macro provided by Qt itself (e.g. Qt 5 provides qt5_wrap_ui()).

Manually create Qt user interfaces Wrappers.

    qt_wrap_ui(resultingLibraryName HeadersDestName
               SourcesDestName SourceLists ...)

Produces .h and .cxx files for all the .ui files listed in the SourceLists. The .h files will be added to the library using the HeadersDestNamesource list. The .cxx files will be added to the library using the SourcesDestNamesource list.

Consider updating the project to use the AUTOUIC target property instead for a more automated way of invoking the uic tool.

  remove

Deprecated since version 3.0: Use the list(REMOVE_ITEM) command instead.

    remove(VAR VALUE VALUE ...)

Removes VALUE from the variable VAR. This is typically used to remove entries from a vector (e.g. semicolon separated list). VALUE is expanded.

  subdir_depends

Disallowed since version 3.0. See CMake Policy CMP0029.

Does nothing.

    subdir_depends(subdir dep1 dep2 ...)

Does not do anything. This command used to help projects order parallel builds correctly. This functionality is now automatic.

  subdirs

Deprecated since version 3.0: Use the add_subdirectory() command instead.

Add a list of subdirectories to the build.

    subdirs(dir1 dir2 ...[EXCLUDE_FROM_ALL exclude_dir1 exclude_dir2 ...]
            [PREORDER])

Add a list of subdirectories to the build. The add_subdirectory() command should be used instead of subdirs although subdirs will still work. This will cause any CMakeLists.txt files in the sub directories to be processed by CMake. Any directories after the PREORDER flag are traversed first by makefile builds, the PREORDER flag has no effect on IDE projects. Any directories after the EXCLUDE_FROM_ALL marker will not be included in the top level makefile or project file. This is useful for having CMake create makefiles or projects for a set of examples in a project. You would want CMake to generate makefiles or project files for all the examples at the same time, but you would not want them to show up in the top level project or be built each time make is run from the top.

  use_mangled_mesa

Disallowed since version 3.0. See CMake Policy CMP0030.

Copy mesa headers for use in combination with system GL.

    use_mangled_mesa(PATH_TO_MESA OUTPUT_DIRECTORY)

The path to mesa includes, should contain gl_mangle.h. The mesa headers are copied to the specified output directory. This allows mangled mesa headers to override other GL headers by being added to the include directory path earlier.

  utility_source

Disallowed since version 3.0. See CMake Policy CMP0034.

Specify the source tree of a third-party utility.

    utility_source(cache_entry executable_name
                   path_to_source [file1 file2 ...])

When a third-party utility's source is included in the distribution, this command specifies its location and name. The cache entry will not be set unless the path_to_source and all listed files exist. It is assumed that the source tree of the utility will have been built before it is needed.

When cross compiling CMake will print a warning if a utility_source() command is executed, because in many cases it is used to build an executable which is executed later on. This doesn't work when cross compiling, since the executable can run only on their target platform. So in this case the cache entry has to be adjusted manually so it points to an executable which is runnable on the build host.

  variable_requires

Disallowed since version 3.0. See CMake Policy CMP0035.

Use the if() command instead.

Assert satisfaction of an option's required variables.

    variable_requires(TEST_VARIABLE RESULT_VARIABLE
                      REQUIRED_VARIABLE1
                      REQUIRED_VARIABLE2 ...)

The first argument (TEST_VARIABLE) is the name of the variable to be tested, if that variable is false nothing else is done. If TEST_VARIABLE is true, then the next argument (RESULT_VARIABLE) is a variable that is set to true if all the required variables are set. The rest of the arguments are variables that must be true or not set to NOTFOUND to avoid an error. If any are not true, an error is reported.

  write_file

Deprecated since version 3.0: Use the file(WRITE) command instead.

    write_file(filename "message to write"... [APPEND])

The first argument is the file name, the rest of the arguments are messages to write. If the argument APPEND is specified, then the message will be appended.

NOTE 1: file(WRITE) and file(APPEND) do exactly the same as this one but add some more functionality.

NOTE 2: When using write_file the produced file cannot be used as an input to CMake (CONFIGURE_FILE, source file ...) because it will lead to an infinite loop. Use configure_file() if you want to generate input files to CMake.

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